2024-04-29 23:34:05

by Michael Grzeschik

[permalink] [raw]
Subject: [PATCH v4 0/3] usb: gadget: 9pfs transport

This series is adding support to mount usb hostside exported 9pfs
filesystems via the usb gadget interface. It also includes a simple tool
(p9_fwd.py) to translate an tcp 9pfs transport and reuse it via the usb
interface.

+--------------------------+ | +--------------------------+
| 9PFS mounting client | | | 9PFS exporting server |
SW | | | | |
| (this:trans_usbg) | | |(e.g. diod or nfs-ganesha)|
+-------------^------------+ | +-------------^------------+
| | |
| | +------v------+
| | | p9_fwd.py |
| | +------^------+
| | |
------------------|------------------------------------|-------------
| | |
+-------------v------------+ | +-------------v------------+
| | | | |
HW | USB Device Controller <---------> USB Host Controller |
| | | | |
+--------------------------+ | +--------------------------+

The USB host exports a filesystem, while the gadget on the USB device
side makes it mountable.

Diod (9pfs server) and the forwarder are on the development host, where
the root filesystem is actually stored. The gadget is initialized during
boot (or later) on the embedded board. Then the forwarder will find it
on the USB bus and start forwarding requests.

In this case the 9p requests come from the device and are handled by the
host. The reason is that USB device ports are normally not available on
PCs, so a connection in the other direction would not work.

One use-case is to use it as an alternative to NFS root booting during
the development of embedded Linux devices.

Signed-off-by: Michael Grzeschik <[email protected]>
---
Changes in v4:
- reworked the naming scheme to be set by the configfs instance
- added conn_cancel function to properly stop the transfers
- ensured that umount -f will work even when the host side has crahed
- added all the review feedback from Andrzej Pietrasiewicz
- Link to v3: https://lore.kernel.org/r/[email protected]

Changes in v3:
- dropped patch "usb: gadget: legacy: add 9pfs multi gadget" as discussed with gregkh
- Link to v2: https://lore.kernel.org/r/[email protected]

Changes in v2:
- improved the commit messages
- introduced an patch to move the header u_f.h to include/linux/usb to compile usb gadget functions treewide
- moved usbg gadget function to net/9p/
- adderessed several comments in function driver, like the cleanup path and kbuild errors
- improved the documentation in Documentation/filesystems/9p.rst
- Link to v1: https://lore.kernel.org/r/[email protected]

---
Michael Grzeschik (3):
usb: gadget: function: move u_f.h to include/linux/usb/
net/9p/usbg: Add new usb gadget function transport
tools: usb: p9_fwd: add usb gadget packet forwarder script

Documentation/filesystems/9p.rst | 49 +-
drivers/usb/gadget/configfs.c | 2 +-
drivers/usb/gadget/function/f_fs.c | 2 +-
drivers/usb/gadget/function/f_hid.c | 2 +-
drivers/usb/gadget/function/f_loopback.c | 2 +-
drivers/usb/gadget/function/f_midi.c | 2 +-
drivers/usb/gadget/function/f_midi2.c | 2 +-
drivers/usb/gadget/function/f_sourcesink.c | 2 +-
drivers/usb/gadget/u_f.c | 2 +-
{drivers/usb/gadget => include/linux/usb}/u_f.h | 0
net/9p/Kconfig | 6 +
net/9p/Makefile | 4 +
net/9p/trans_usbg.c | 983 ++++++++++++++++++++++++
tools/usb/p9_fwd.py | 194 +++++
14 files changed, 1243 insertions(+), 9 deletions(-)
---
base-commit: d03d4188908883e1705987795a09aeed31424f66
change-id: 20240116-ml-topic-u9p-895274530eb1

Best regards,
--
Michael Grzeschik <[email protected]>



2024-04-29 23:34:13

by Michael Grzeschik

[permalink] [raw]
Subject: [PATCH v4 1/3] usb: gadget: function: move u_f.h to include/linux/usb/

We move the u_f.h header to include/linux/usb to be
able to compile function drivers outside of the
drivers/usb/gadget/function directory.

Signed-off-by: Michael Grzeschik <[email protected]>

---
v3 -> v4: -
v2 -> v3: -
v1 -> v2:
- new introduced patch
---
drivers/usb/gadget/configfs.c | 2 +-
drivers/usb/gadget/function/f_fs.c | 2 +-
drivers/usb/gadget/function/f_hid.c | 2 +-
drivers/usb/gadget/function/f_loopback.c | 2 +-
drivers/usb/gadget/function/f_midi.c | 2 +-
drivers/usb/gadget/function/f_midi2.c | 2 +-
drivers/usb/gadget/function/f_sourcesink.c | 2 +-
drivers/usb/gadget/u_f.c | 2 +-
{drivers/usb/gadget => include/linux/usb}/u_f.h | 0
9 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index ce3cfa1f36f51..4fa3eeafba814 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -8,8 +8,8 @@
#include <linux/usb/composite.h>
#include <linux/usb/gadget_configfs.h>
#include <linux/usb/webusb.h>
+#include <linux/usb/u_f.h>
#include "configfs.h"
-#include "u_f.h"
#include "u_os_desc.h"

int check_user_usb_string(const char *name,
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index f855f1fc8e5e1..3fcb957e75386 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -33,6 +33,7 @@
#include <linux/usb/ccid.h>
#include <linux/usb/composite.h>
#include <linux/usb/functionfs.h>
+#include <linux/usb/u_f.h>

#include <linux/aio.h>
#include <linux/kthread.h>
@@ -40,7 +41,6 @@
#include <linux/eventfd.h>

#include "u_fs.h"
-#include "u_f.h"
#include "u_os_desc.h"
#include "configfs.h"

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index 3c8a9dd585c09..a5b667a03ca83 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -16,8 +16,8 @@
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/usb/g_hid.h>
+#include <linux/usb/u_f.h>

-#include "u_f.h"
#include "u_hid.h"

#define HIDG_MINORS 4
diff --git a/drivers/usb/gadget/function/f_loopback.c b/drivers/usb/gadget/function/f_loopback.c
index 17ac6ace0cffa..d500025f45128 100644
--- a/drivers/usb/gadget/function/f_loopback.c
+++ b/drivers/usb/gadget/function/f_loopback.c
@@ -14,9 +14,9 @@
#include <linux/module.h>
#include <linux/err.h>
#include <linux/usb/composite.h>
+#include <linux/usb/u_f.h>

#include "g_zero.h"
-#include "u_f.h"

/*
* LOOPBACK FUNCTION ... a testing vehicle for USB peripherals,
diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
index 20c6fbd94f32d..2d551ba385c71 100644
--- a/drivers/usb/gadget/function/f_midi.c
+++ b/drivers/usb/gadget/function/f_midi.c
@@ -33,8 +33,8 @@
#include <linux/usb/gadget.h>
#include <linux/usb/audio.h>
#include <linux/usb/midi.h>
+#include <linux/usb/u_f.h>

-#include "u_f.h"
#include "u_midi.h"

MODULE_AUTHOR("Ben Williamson");
diff --git a/drivers/usb/gadget/function/f_midi2.c b/drivers/usb/gadget/function/f_midi2.c
index ec8cd7c7bbfc1..ad59be1f9c54d 100644
--- a/drivers/usb/gadget/function/f_midi2.c
+++ b/drivers/usb/gadget/function/f_midi2.c
@@ -18,8 +18,8 @@
#include <linux/usb/gadget.h>
#include <linux/usb/audio.h>
#include <linux/usb/midi-v2.h>
+#include <linux/usb/u_f.h>

-#include "u_f.h"
#include "u_midi2.h"

struct f_midi2;
diff --git a/drivers/usb/gadget/function/f_sourcesink.c b/drivers/usb/gadget/function/f_sourcesink.c
index 2edbd9b510d60..4283fb2e365bd 100644
--- a/drivers/usb/gadget/function/f_sourcesink.c
+++ b/drivers/usb/gadget/function/f_sourcesink.c
@@ -13,10 +13,10 @@
#include <linux/device.h>
#include <linux/module.h>
#include <linux/usb/composite.h>
+#include <linux/usb/u_f.h>
#include <linux/err.h>

#include "g_zero.h"
-#include "u_f.h"

/*
* SOURCE/SINK FUNCTION ... a primary testing vehicle for USB peripheral
diff --git a/drivers/usb/gadget/u_f.c b/drivers/usb/gadget/u_f.c
index 6aea1ecb39999..90a7f742549a4 100644
--- a/drivers/usb/gadget/u_f.c
+++ b/drivers/usb/gadget/u_f.c
@@ -8,7 +8,7 @@
* Author: Andrzej Pietrasiewicz <[email protected]>
*/

-#include "u_f.h"
+#include <linux/usb/u_f.h>
#include <linux/usb/ch9.h>

struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len)
diff --git a/drivers/usb/gadget/u_f.h b/include/linux/usb/u_f.h
similarity index 100%
rename from drivers/usb/gadget/u_f.h
rename to include/linux/usb/u_f.h

--
2.39.2


2024-04-29 23:34:23

by Michael Grzeschik

[permalink] [raw]
Subject: [PATCH v4 3/3] tools: usb: p9_fwd: add usb gadget packet forwarder script

This patch is adding an small python tool to forward 9pfs requests
from the USB gadget to an existing 9pfs TCP server. Since currently all
9pfs servers lack support for the usb transport this tool is an useful
helper to get started.

Refer the Documentation section "USBG Example" in
Documentation/filesystems/9p.rst on how to use it.

Signed-off-by: Michael Grzeschik <[email protected]>

---
v3 -> v4: -
v2 -> v3: -
v1 -> v2:
- added usbg 9pfs detailed instructions to 9p.rst doc
---
Documentation/filesystems/9p.rst | 32 +++++++
tools/usb/p9_fwd.py | 194 +++++++++++++++++++++++++++++++++++++++
2 files changed, 226 insertions(+)

diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst
index 10cf79dc287f8..2467f1ea4a150 100644
--- a/Documentation/filesystems/9p.rst
+++ b/Documentation/filesystems/9p.rst
@@ -67,6 +67,38 @@ To mount a 9p FS on a USB Host accessible via the gadget as root filesystem::
where <device> is the tag associated by the usb gadget transport.
It is defined by the configfs instance name.

+USBG Example
+============
+
+The USB host exports a filesystem, while the gadget on the USB device
+side makes it mountable.
+
+Diod (9pfs server) and the forwarder are on the development host, where
+the root filesystem is actually stored. The gadget is initialized during
+boot (or later) on the embedded board. Then the forwarder will find it
+on the USB bus and start forwarding requests.
+
+In this case the 9p requests come from the device and are handled by the
+host. The reason is that USB device ports are normally not available on
+PCs, so a connection in the other direction would not work.
+
+When using the usbg transport, for now there is no native usb host
+service capable to handle the requests from the gadget driver. For
+this we have to use the extra python tool p9_fwd.py from tools/usb.
+
+Just start the 9pfs capable network server like diod/nfs-ganesha e.g.:
+
+ $ diod -f -n -d 0 -S -l 0.0.0.0:9999 -e $PWD
+
+Then start the python transport:
+
+ $ python $kernel_dir/tools/usb/p9_fwd.py -p 9999
+
+After that the gadget driver can be used as described above.
+
+One use-case is to use it as an alternative to NFS root booting during
+the development of embedded Linux devices.
+
Options
=======

diff --git a/tools/usb/p9_fwd.py b/tools/usb/p9_fwd.py
new file mode 100755
index 0000000000000..95208df11abef
--- /dev/null
+++ b/tools/usb/p9_fwd.py
@@ -0,0 +1,194 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+import argparse
+import errno
+import logging
+import socket
+import struct
+import sys
+import time
+
+import usb.core
+import usb.util
+
+
+class Forwarder:
+ HEXDUMP_FILTER = (
+ "".join(chr(x).isprintable() and chr(x) or "." for x in range(128)) + "." * 128
+ )
+
+ @staticmethod
+ def _log_hexdump(data):
+ if not logging.root.isEnabledFor(logging.TRACE):
+ return
+ L = 16
+ for c in range(0, len(data), L):
+ chars = data[c : c + L]
+ dump = " ".join(f"{x:02x}" for x in chars)
+ printable = "".join(HEXDUMP_FILTER[x] for x in chars)
+ line = f"{c:08x} {dump:{L*3}s} |{printable:{L}s}|"
+ logging.root.log(logging.TRACE, "%s", line)
+
+ def __init__(self, server):
+ self.stats = {
+ "c2s packets": 0,
+ "c2s bytes": 0,
+ "s2c packets": 0,
+ "s2c bytes": 0,
+ }
+ self.stats_logged = time.monotonic()
+
+ dev = usb.core.find(idVendor=0x1D6B, idProduct=0x0109)
+ if dev is None:
+ raise ValueError("Device not found")
+
+ logging.info(f"found device: {dev.bus}/{dev.address}")
+
+ # dev.set_configuration() is not necessary since g_multi has only one
+ usb9pfs = None
+ # g_multi adds 9pfs as last interface
+ cfg = dev.get_active_configuration()
+ for intf in cfg:
+ # we have to detach the usb-storage driver from multi gadget since
+ # stall option could be set, which will lead to spontaneous port
+ # resets and our transfers will run dead
+ if intf.bInterfaceClass == 0x08:
+ if dev.is_kernel_driver_active(intf.bInterfaceNumber):
+ dev.detach_kernel_driver(intf.bInterfaceNumber)
+
+ if (
+ intf.bInterfaceClass == 0xFF
+ and intf.bInterfaceSubClass == 0xFF
+ and intf.bInterfaceProtocol == 0x09
+ ):
+ usb9pfs = intf
+ if usb9pfs is None:
+ raise ValueError("Interface not found")
+
+ logging.info(f"claiming interface:\n{usb9pfs}")
+ usb.util.claim_interface(dev, usb9pfs.bInterfaceNumber)
+ ep_out = usb.util.find_descriptor(
+ usb9pfs,
+ custom_match=lambda e: usb.util.endpoint_direction(e.bEndpointAddress)
+ == usb.util.ENDPOINT_OUT,
+ )
+ assert ep_out is not None
+ ep_in = usb.util.find_descriptor(
+ usb9pfs,
+ custom_match=lambda e: usb.util.endpoint_direction(e.bEndpointAddress)
+ == usb.util.ENDPOINT_IN,
+ )
+ assert ep_in is not None
+ logging.info(f"interface claimed")
+
+ self.ep_out = ep_out
+ self.ep_in = ep_in
+ self.dev = dev
+
+ # create and connect socket
+ self.s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+ self.s.connect(server)
+
+ logging.info(f"connected to server")
+
+ def c2s(self):
+ """forward a request from the USB client to the TCP server"""
+ data = None
+ while data is None:
+ try:
+ logging.log(logging.TRACE, "c2s: reading")
+ data = self.ep_in.read(self.ep_in.wMaxPacketSize)
+ except usb.core.USBTimeoutError:
+ logging.log(logging.TRACE, "c2s: reading timed out")
+ continue
+ except usb.core.USBError as e:
+ if e.errno == errno.EIO:
+ logging.debug("c2s: reading failed with %s, retrying", repr(e))
+ time.sleep(0.5)
+ continue
+ else:
+ logging.error("c2s: reading failed with %s, aborting", repr(e))
+ raise
+ size = struct.unpack("<I", data[:4])[0]
+ while len(data) < size:
+ data += self.ep_in.read(size - len(data))
+ logging.log(logging.TRACE, "c2s: writing")
+ self._log_hexdump(data)
+ self.s.send(data)
+ logging.debug("c2s: forwarded %i bytes", size)
+ self.stats["c2s packets"] += 1
+ self.stats["c2s bytes"] += size
+
+ def s2c(self):
+ """forward a response from the TCP server to the USB client"""
+ logging.log(logging.TRACE, "s2c: reading")
+ data = self.s.recv(4)
+ size = struct.unpack("<I", data[:4])[0]
+ while len(data) < size:
+ data += self.s.recv(size - len(data))
+ logging.log(logging.TRACE, "s2c: writing")
+ self._log_hexdump(data)
+ while data:
+ written = self.ep_out.write(data)
+ assert written > 0
+ data = data[written:]
+ if size % self.ep_out.wMaxPacketSize == 0:
+ logging.log(logging.TRACE, "sending zero length packet")
+ self.ep_out.write(b"")
+ logging.debug("s2c: forwarded %i bytes", size)
+ self.stats["s2c packets"] += 1
+ self.stats["s2c bytes"] += size
+
+ def log_stats(self):
+ logging.info("statistics:")
+ for k, v in self.stats.items():
+ logging.info(f" {k+':':14s} {v}")
+
+ def log_stats_interval(self, interval=5):
+ if (time.monotonic() - self.stats_logged) < interval:
+ return
+
+ self.log_stats()
+ self.stats_logged = time.monotonic()
+
+
+def main():
+ parser = argparse.ArgumentParser(
+ description="Forward 9PFS requests from USB to TCP",
+ )
+
+ parser.add_argument(
+ "-s", "--server", type=str, default="127.0.0.1", help="server hostname"
+ )
+ parser.add_argument("-p", "--port", type=int, default=564, help="server port")
+ parser.add_argument("-v", "--verbose", action="count", default=0)
+
+ args = parser.parse_args()
+
+ logging.TRACE = logging.DEBUG - 5
+ logging.addLevelName(logging.TRACE, "TRACE")
+
+ if args.verbose >= 2:
+ level = logging.TRACE
+ elif args.verbose:
+ level = logging.DEBUG
+ else:
+ level = logging.INFO
+ logging.basicConfig(
+ level=level, format="%(asctime)-15s %(levelname)-8s %(message)s"
+ )
+
+ f = Forwarder(server=(args.server, args.port))
+
+ try:
+ while True:
+ f.c2s()
+ f.s2c()
+ f.log_stats_interval()
+ finally:
+ f.log_stats()
+
+
+if __name__ == "__main__":
+ main()

--
2.39.2


2024-04-29 23:34:55

by Michael Grzeschik

[permalink] [raw]
Subject: [PATCH v4 2/3] net/9p/usbg: Add new usb gadget function transport

Add the new gadget function for 9pfs transport. This function is
defining an simple 9pfs transport interface that consists of one in and
one out endpoint. The endpoints transmit and receive the 9pfs protocol
payload when mounting a 9p filesystem over usb.

Signed-off-by: Michael Grzeschik <[email protected]>

---
v3 -> v4:
- implemented conn_cancel
- moved from mount_tag to device name like ffs does
- renamed function_list to usb9pfs_instance
- renamed usbg_function_list to usb9pfs_instance_list
- renamed rx/tx_fill to queue_rx/tx
- added use of retvals
- added locking comment over usb9pfs_transmit
- using if_else instead of two pathed switch calls
- fixed return values of completion handler
- using void pointer as parameter in rx_header
- added a missed req_put in rx_header
- removed extra disable function but call disable_ep directly
- repaired several return values
- remove the suspicious disable / enable path in usbg_create
v2 -> v3: -
v1 -> v2:
- move the driver to net/9p/trans_usbg.c
- fixed the commit title
- fix %zu usage in p9_debug for size_t type
- define functions static that are only used localy
- return 0 in alloc_requests
- use id_alloc_max instead of ida_simple_get
- call ida_free in usb9pfs_free_func
- call kfree for usb9pfs->tag and usb9pfs in usb9pfs_free_func
- add MODULE_ALIAS_9P to load this module automatic when mounting
- improved the documentation
- added depends on USB_GADGET in Kconfig
---
Documentation/filesystems/9p.rst | 17 +-
net/9p/Kconfig | 6 +
net/9p/Makefile | 4 +
net/9p/trans_usbg.c | 983 +++++++++++++++++++++++++++++++++++++++
4 files changed, 1009 insertions(+), 1 deletion(-)

diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst
index 1e0e0bb6fdf91..10cf79dc287f8 100644
--- a/Documentation/filesystems/9p.rst
+++ b/Documentation/filesystems/9p.rst
@@ -48,11 +48,25 @@ For server running on QEMU host with virtio transport::

mount -t 9p -o trans=virtio <mount_tag> /mnt/9

-where mount_tag is the tag associated by the server to each of the exported
+where mount_tag is the tag generated by the server to each of the exported
mount points. Each 9P export is seen by the client as a virtio device with an
associated "mount_tag" property. Available mount tags can be
seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.

+USBG Usage
+==========
+
+To mount a 9p FS on a USB Host accessible via the gadget at runtime::
+
+ mount -t 9p -o trans=usbg,aname=/path/to/fs <device> /mnt/9
+
+To mount a 9p FS on a USB Host accessible via the gadget as root filesystem::
+
+ root=<device> rootfstype=9p rootflags=trans=usbg,cache=loose,uname=root,access=0,dfltuid=0,dfltgid=0,aname=/path/to/rootfs
+
+where <device> is the tag associated by the usb gadget transport.
+It is defined by the configfs instance name.
+
Options
=======

@@ -68,6 +82,7 @@ Options
virtio connect to the next virtio channel available
(from QEMU with trans_virtio module)
rdma connect to a specified RDMA channel
+ usbg connect to a specified usb gadget channel
======== ============================================

uname=name user name to attempt mount as on the remote server. The
diff --git a/net/9p/Kconfig b/net/9p/Kconfig
index 00ebce9e5a657..c3d357eb8bb37 100644
--- a/net/9p/Kconfig
+++ b/net/9p/Kconfig
@@ -39,6 +39,12 @@ config NET_9P_XEN
This builds support for a transport for 9pfs between
two Xen domains.

+config NET_9P_USBG
+ bool "9P USB Gadget Transport"
+ depends on USB_GADGET
+ help
+ This builds support for a transport for 9pfs over
+ usb gadget.

config NET_9P_RDMA
depends on INET && INFINIBAND && INFINIBAND_ADDR_TRANS
diff --git a/net/9p/Makefile b/net/9p/Makefile
index 1df9b344c30bd..22794a451c3f7 100644
--- a/net/9p/Makefile
+++ b/net/9p/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
obj-$(CONFIG_NET_9P_XEN) += 9pnet_xen.o
obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o
obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
+obj-$(CONFIG_NET_9P_USBG) += 9pnet_usbg.o

9pnet-objs := \
mod.o \
@@ -23,3 +24,6 @@ obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o

9pnet_rdma-objs := \
trans_rdma.o \
+
+9pnet_usbg-objs := \
+ trans_usbg.o \
diff --git a/net/9p/trans_usbg.c b/net/9p/trans_usbg.c
new file mode 100644
index 0000000000000..bc440033cbe68
--- /dev/null
+++ b/net/9p/trans_usbg.c
@@ -0,0 +1,983 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * trans_usbg.c - USB peripheral usb9pfs configuration driver and transport.
+ *
+ * Copyright (C) 2024 Michael Grzeschik <[email protected]>
+ */
+
+/* Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs
+ * transport to mount host exported filesystem via usb gadget.
+ */
+
+/* +--------------------------+ | +--------------------------+
+ * | 9PFS mounting client | | | 9PFS exporting server |
+ * SW | | | | |
+ * | (this:trans_usbg) | | |(e.g. diod or nfs-ganesha)|
+ * +-------------^------------+ | +-------------^------------+
+ * | | |
+ * ------------------|------------------------------------|-------------
+ * | | |
+ * +-------------v------------+ | +-------------v------------+
+ * | | | | |
+ * HW | USB Device Controller <---------> USB Host Controller |
+ * | | | | |
+ * +--------------------------+ | +--------------------------+
+ */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/usb/composite.h>
+#include <linux/usb/u_f.h>
+
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+#include <net/9p/transport.h>
+
+#define DEFAULT_BUFLEN 16384
+
+struct f_usb9pfs {
+ struct p9_client *client;
+
+ struct p9_req_t *p9_tx_req;
+
+ struct list_head tx_req_list;
+
+ /* 9p request lock for en/dequeue */
+ spinlock_t lock;
+ /* usb request lock for en/dequeue */
+ spinlock_t req_lock;
+
+ struct usb_request *in_req;
+ struct usb_request *out_req;
+
+ struct usb_ep *in_ep;
+ struct usb_ep *out_ep;
+
+ unsigned int buflen;
+
+ struct usb_function function;
+};
+
+static inline struct f_usb9pfs *func_to_usb9pfs(struct usb_function *f)
+{
+ return container_of(f, struct f_usb9pfs, function);
+}
+
+struct f_usb9pfs_opts {
+ struct usb_function_instance func_inst;
+ unsigned int buflen;
+
+ struct f_usb9pfs_dev *dev;
+
+ /* Read/write access to configfs attributes is handled by configfs.
+ *
+ * This is to protect the data from concurrent access by read/write
+ * and create symlink/remove symlink.
+ */
+ struct mutex lock;
+ int refcnt;
+};
+
+struct f_usb9pfs_dev {
+ struct f_usb9pfs *usb9pfs;
+ struct f_usb9pfs_opts *opts;
+ char tag[41];
+ bool inuse;
+
+ struct list_head usb9pfs_instance;
+};
+
+static DEFINE_MUTEX(usb9pfs_lock);
+static struct list_head usbg_instance_list;
+
+static int usb9pfs_queue_tx(struct f_usb9pfs *usb9pfs, struct usb_request *req,
+ gfp_t gfp_flags)
+{
+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
+ int ret = -ENOMEM;
+
+ if (!(usb9pfs->p9_tx_req->tc.size % usb9pfs->in_ep->maxpacket))
+ req->zero = 1;
+
+ req->buf = usb9pfs->p9_tx_req->tc.sdata;
+ req->length = usb9pfs->p9_tx_req->tc.size;
+
+ dev_dbg(&cdev->gadget->dev, "%s usb9pfs send --> %d/%d, zero: %d\n",
+ usb9pfs->in_ep->name, req->actual, req->length, req->zero);
+
+ ret = usb_ep_queue(usb9pfs->in_ep, req, gfp_flags);
+
+ dev_dbg(&cdev->gadget->dev, "tx submit --> %d\n", ret);
+
+ return ret;
+}
+
+static int usb9pfs_queue_rx(struct f_usb9pfs *usb9pfs, struct usb_request *req,
+ gfp_t gfp_flags)
+{
+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
+ int ret = -ENOMEM;
+
+ ret = usb_ep_queue(usb9pfs->out_ep, req, gfp_flags);
+
+ dev_dbg(&cdev->gadget->dev, "rx submit --> %d\n", ret);
+
+ return ret;
+}
+
+/* This needs to be called with usb9pfs->req_lock held */
+static int usb9pfs_transmit(struct f_usb9pfs *usb9pfs)
+{
+ struct p9_req_t *p9_req = NULL;
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&usb9pfs->lock, flags);
+
+ if (usb9pfs->p9_tx_req) {
+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
+ return -EBUSY;
+ }
+
+ p9_req = list_first_entry_or_null(&usb9pfs->tx_req_list,
+ struct p9_req_t, req_list);
+ if (!p9_req) {
+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
+ return -ENOENT;
+ }
+
+ list_del(&p9_req->req_list);
+
+ usb9pfs->p9_tx_req = p9_req;
+
+ p9_req_get(usb9pfs->p9_tx_req);
+
+ ret = usb9pfs_queue_tx(usb9pfs, usb9pfs->in_req, GFP_ATOMIC);
+
+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
+
+ return ret;
+}
+
+static void usb9pfs_tx_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct f_usb9pfs *usb9pfs = ep->driver_data;
+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
+ int ret = 0;
+
+ if (req->status) {
+ dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
+ ep->name, req->status, req->actual, req->length);
+ goto free_req;
+ }
+
+ /* reset zero packages */
+ req->zero = 0;
+
+ dev_dbg(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
+ ep->name, req->status, req->actual, req->length);
+
+ spin_lock(&usb9pfs->req_lock);
+
+ WRITE_ONCE(usb9pfs->p9_tx_req->status, REQ_STATUS_SENT);
+
+ p9_req_put(usb9pfs->client, usb9pfs->p9_tx_req);
+
+ ret = usb9pfs_queue_rx(usb9pfs, usb9pfs->out_req, GFP_ATOMIC);
+ if (ret) {
+ spin_unlock(&usb9pfs->req_lock);
+ goto free_req;
+ }
+
+ spin_unlock(&usb9pfs->req_lock);
+
+ return;
+
+free_req:
+ usb_ep_free_request(ep == usb9pfs->in_ep ?
+ usb9pfs->out_ep : usb9pfs->in_ep,
+ req->context);
+ free_ep_req(ep, req);
+}
+
+static struct p9_req_t *usb9pfs_rx_header(struct f_usb9pfs *usb9pfs, void *buf)
+{
+ struct p9_req_t *p9_rx_req;
+ struct p9_fcall rc;
+ int ret;
+
+ /* start by reading header */
+ rc.sdata = buf;
+ rc.offset = 0;
+ rc.capacity = P9_HDRSZ;
+ rc.size = P9_HDRSZ;
+
+ p9_debug(P9_DEBUG_TRANS, "mux %p got %zu bytes\n", usb9pfs,
+ rc.capacity - rc.offset);
+
+ ret = p9_parse_header(&rc, &rc.size, NULL, NULL, 0);
+ if (ret) {
+ p9_debug(P9_DEBUG_ERROR,
+ "error parsing header: %d\n", ret);
+ return NULL;
+ }
+
+ p9_debug(P9_DEBUG_TRANS,
+ "mux %p pkt: size: %d bytes tag: %d\n",
+ usb9pfs, rc.size, rc.tag);
+
+ p9_rx_req = p9_tag_lookup(usb9pfs->client, rc.tag);
+ if (!p9_rx_req || p9_rx_req->status != REQ_STATUS_SENT) {
+ p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", rc.tag);
+ return NULL;
+ }
+
+ if (rc.size > p9_rx_req->rc.capacity) {
+ p9_debug(P9_DEBUG_ERROR,
+ "requested packet size too big: %d for tag %d with capacity %zd\n",
+ rc.size, rc.tag, p9_rx_req->rc.capacity);
+ p9_req_put(usb9pfs->client, p9_rx_req);
+ return NULL;
+ }
+
+ if (!p9_rx_req->rc.sdata) {
+ p9_debug(P9_DEBUG_ERROR,
+ "No recv fcall for tag %d (req %p), disconnecting!\n",
+ rc.tag, p9_rx_req);
+ p9_req_put(usb9pfs->client, p9_rx_req);
+ return NULL;
+ }
+
+ return p9_rx_req;
+}
+
+static void usb9pfs_rx_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct f_usb9pfs *usb9pfs = ep->driver_data;
+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
+ struct p9_req_t *p9_rx_req;
+ unsigned long flags;
+ int ret = 0;
+
+ if (req->status) {
+ dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
+ ep->name, req->status, req->actual, req->length);
+ goto free_req;
+ }
+
+ spin_lock_irqsave(&usb9pfs->req_lock, flags);
+
+ p9_rx_req = usb9pfs_rx_header(usb9pfs, req->buf);
+ if (!p9_rx_req) {
+ spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
+ goto free_req;
+ }
+
+ memcpy(p9_rx_req->rc.sdata, req->buf, req->actual);
+
+ p9_rx_req->rc.size = req->actual;
+
+ p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_RCVD);
+ p9_req_put(usb9pfs->client, p9_rx_req);
+
+ usb9pfs->p9_tx_req = NULL;
+
+ ret = usb9pfs_transmit(usb9pfs);
+ if (ret) {
+ spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
+ return;
+ }
+
+ spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
+
+ return;
+
+free_req:
+ usb_ep_free_request(ep == usb9pfs->in_ep ?
+ usb9pfs->out_ep : usb9pfs->in_ep,
+ req->context);
+ free_ep_req(ep, req);
+
+ p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_ERROR);
+}
+
+static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
+{
+ int value;
+
+ value = usb_ep_disable(ep);
+ if (value < 0)
+ dev_info(&cdev->gadget->dev,
+ "disable %s --> %d\n", ep->name, value);
+}
+
+static void disable_usb9pfs(struct f_usb9pfs *usb9pfs)
+{
+ struct usb_composite_dev *cdev =
+ usb9pfs->function.config->cdev;
+
+ disable_ep(cdev, usb9pfs->in_ep);
+ disable_ep(cdev, usb9pfs->out_ep);
+ dev_dbg(&cdev->gadget->dev, "%s disabled\n",
+ usb9pfs->function.name);
+}
+
+static int alloc_requests(struct usb_composite_dev *cdev,
+ struct f_usb9pfs *usb9pfs)
+{
+ int ret = 0;
+
+ usb9pfs->in_req = usb_ep_alloc_request(usb9pfs->in_ep, GFP_ATOMIC);
+ if (!usb9pfs->in_req) {
+ ret = -ENOENT;
+ goto fail;
+ }
+
+ usb9pfs->out_req = alloc_ep_req(usb9pfs->out_ep, usb9pfs->buflen);
+ if (!usb9pfs->out_req) {
+ ret = -ENOENT;
+ goto fail_in;
+ }
+
+ usb9pfs->in_req->complete = usb9pfs_tx_complete;
+ usb9pfs->out_req->complete = usb9pfs_rx_complete;
+
+ /* length will be set in complete routine */
+ usb9pfs->in_req->context = usb9pfs;
+ usb9pfs->out_req->context = usb9pfs;
+
+ return ret;
+
+fail_in:
+ usb_ep_free_request(usb9pfs->in_ep, usb9pfs->in_req);
+fail:
+ return ret;
+}
+
+static int enable_endpoint(struct usb_composite_dev *cdev,
+ struct f_usb9pfs *usb9pfs, struct usb_ep *ep)
+{
+ int ret;
+
+ ret = config_ep_by_speed(cdev->gadget, &usb9pfs->function, ep);
+ if (ret)
+ return ret;
+
+ ret = usb_ep_enable(ep);
+ if (ret < 0)
+ return ret;
+
+ ep->driver_data = usb9pfs;
+
+ return ret;
+}
+
+static int
+enable_usb9pfs(struct usb_composite_dev *cdev, struct f_usb9pfs *usb9pfs)
+{
+ int result = 0;
+
+ result = enable_endpoint(cdev, usb9pfs, usb9pfs->in_ep);
+ if (result)
+ goto out;
+
+ result = enable_endpoint(cdev, usb9pfs, usb9pfs->out_ep);
+ if (result)
+ goto disable_in;
+
+ result = alloc_requests(cdev, usb9pfs);
+ if (result)
+ goto disable_out;
+
+ dev_dbg(&cdev->gadget->dev, "%s enabled\n", usb9pfs->function.name);
+ return 0;
+
+disable_out:
+ usb_ep_disable(usb9pfs->out_ep);
+disable_in:
+ usb_ep_disable(usb9pfs->in_ep);
+out:
+ return result;
+}
+
+static int p9_usbg_create(struct p9_client *client, const char *devname, char *args)
+{
+ struct usb_composite_dev *cdev;
+ struct f_usb9pfs_dev *dev;
+ struct f_usb9pfs_dev *tmp;
+ struct f_usb9pfs *usb9pfs;
+ struct usb_function *f;
+ int ret = -ENOENT;
+ int found = 0;
+
+ if (!devname)
+ return -EINVAL;
+
+ mutex_lock(&usb9pfs_lock);
+ list_for_each_entry_safe(dev, tmp, &usbg_instance_list, usb9pfs_instance) {
+ if (!strncmp(devname, dev->tag, strlen(devname))) {
+ if (!dev->inuse) {
+ dev->inuse = true;
+ found = 1;
+ break;
+ }
+ ret = -EBUSY;
+ break;
+ }
+ }
+ mutex_unlock(&usb9pfs_lock);
+
+ if (!found) {
+ pr_err("no channels available for device %s\n", devname);
+ return ret;
+ }
+
+ usb9pfs = dev->usb9pfs;
+ if (!usb9pfs)
+ return -EINVAL;
+
+ INIT_LIST_HEAD(&usb9pfs->tx_req_list);
+
+ spin_lock_init(&usb9pfs->lock);
+ spin_lock_init(&usb9pfs->req_lock);
+
+ f = &usb9pfs->function;
+ cdev = f->config->cdev;
+
+ client->trans = (void *)usb9pfs;
+ client->status = Connected;
+ usb9pfs->client = client;
+
+ client->trans_mod->maxsize = usb9pfs->buflen;
+
+ return enable_usb9pfs(cdev, usb9pfs);
+}
+
+static void p9_usbg_close(struct p9_client *client)
+{
+ struct f_usb9pfs *usb9pfs;
+ struct f_usb9pfs_dev *dev;
+ struct p9_req_t *req;
+ struct f_usb9pfs_opts *opts;
+
+ if (!client)
+ return;
+
+ usb9pfs = client->trans;
+ if (!usb9pfs)
+ return;
+
+ client->status = Disconnected;
+
+ spin_lock(&usb9pfs->req_lock);
+
+ req = usb9pfs->p9_tx_req;
+ if (req) {
+ if (!req->t_err)
+ req->t_err = -ECONNRESET;
+ p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR);
+ }
+
+ spin_unlock(&usb9pfs->req_lock);
+
+ disable_usb9pfs(usb9pfs);
+
+ opts = container_of(usb9pfs->function.fi,
+ struct f_usb9pfs_opts, func_inst);
+
+ dev = opts->dev;
+
+ mutex_lock(&usb9pfs_lock);
+ dev->inuse = false;
+ mutex_unlock(&usb9pfs_lock);
+}
+
+static int p9_usbg_request(struct p9_client *client, struct p9_req_t *p9_req)
+{
+ struct f_usb9pfs *usb9pfs = client->trans;
+ unsigned long flags;
+
+ if (client->status != Connected)
+ return -EBUSY;
+
+ spin_lock_irqsave(&usb9pfs->lock, flags);
+ list_add_tail(&p9_req->req_list, &usb9pfs->tx_req_list);
+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
+
+ spin_lock_irqsave(&usb9pfs->req_lock, flags);
+ usb9pfs_transmit(usb9pfs);
+ spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
+
+ return 0;
+}
+
+static int p9_usbg_cancel(struct p9_client *client, struct p9_req_t *req)
+{
+ struct f_usb9pfs *usb9pfs = client->trans;
+ int ret = 1;
+
+ p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
+
+ spin_lock(&usb9pfs->req_lock);
+
+ if (req->status == REQ_STATUS_UNSENT) {
+ list_del(&req->req_list);
+ WRITE_ONCE(req->status, REQ_STATUS_FLSHD);
+ p9_req_put(client, req);
+ ret = 0;
+ }
+ spin_unlock(&usb9pfs->req_lock);
+
+ return ret;
+}
+
+static struct p9_trans_module p9_usbg_trans = {
+ .name = "usbg",
+ .create = p9_usbg_create,
+ .close = p9_usbg_close,
+ .request = p9_usbg_request,
+ .cancel = p9_usbg_cancel,
+ .owner = THIS_MODULE,
+};
+
+/*-------------------------------------------------------------------------*/
+
+#define USB_PROTOCOL_9PFS 0x09
+
+static struct usb_interface_descriptor usb9pfs_intf = {
+ .bLength = sizeof(usb9pfs_intf),
+ .bDescriptorType = USB_DT_INTERFACE,
+
+ .bNumEndpoints = 2,
+ .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
+ .bInterfaceSubClass = USB_SUBCLASS_VENDOR_SPEC,
+ .bInterfaceProtocol = USB_PROTOCOL_9PFS,
+
+ /* .iInterface = DYNAMIC */
+};
+
+/* full speed support: */
+
+static struct usb_endpoint_descriptor fs_usb9pfs_source_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor fs_usb9pfs_sink_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *fs_usb9pfs_descs[] = {
+ (struct usb_descriptor_header *)&usb9pfs_intf,
+ (struct usb_descriptor_header *)&fs_usb9pfs_sink_desc,
+ (struct usb_descriptor_header *)&fs_usb9pfs_source_desc,
+ NULL,
+};
+
+/* high speed support: */
+
+static struct usb_endpoint_descriptor hs_usb9pfs_source_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor hs_usb9pfs_sink_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *hs_usb9pfs_descs[] = {
+ (struct usb_descriptor_header *)&usb9pfs_intf,
+ (struct usb_descriptor_header *)&hs_usb9pfs_source_desc,
+ (struct usb_descriptor_header *)&hs_usb9pfs_sink_desc,
+ NULL,
+};
+
+/* super speed support: */
+
+static struct usb_endpoint_descriptor ss_usb9pfs_source_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor ss_usb9pfs_source_comp_desc = {
+ .bLength = USB_DT_SS_EP_COMP_SIZE,
+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+ .bMaxBurst = 0,
+ .bmAttributes = 0,
+ .wBytesPerInterval = 0,
+};
+
+static struct usb_endpoint_descriptor ss_usb9pfs_sink_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor ss_usb9pfs_sink_comp_desc = {
+ .bLength = USB_DT_SS_EP_COMP_SIZE,
+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+ .bMaxBurst = 0,
+ .bmAttributes = 0,
+ .wBytesPerInterval = 0,
+};
+
+static struct usb_descriptor_header *ss_usb9pfs_descs[] = {
+ (struct usb_descriptor_header *)&usb9pfs_intf,
+ (struct usb_descriptor_header *)&ss_usb9pfs_source_desc,
+ (struct usb_descriptor_header *)&ss_usb9pfs_source_comp_desc,
+ (struct usb_descriptor_header *)&ss_usb9pfs_sink_desc,
+ (struct usb_descriptor_header *)&ss_usb9pfs_sink_comp_desc,
+ NULL,
+};
+
+/* function-specific strings: */
+static struct usb_string strings_usb9pfs[] = {
+ [0].s = "usb9pfs input to output",
+ { } /* end of list */
+};
+
+static struct usb_gadget_strings stringtab_usb9pfs = {
+ .language = 0x0409, /* en-us */
+ .strings = strings_usb9pfs,
+};
+
+static struct usb_gadget_strings *usb9pfs_strings[] = {
+ &stringtab_usb9pfs,
+ NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int usb9pfs_func_bind(struct usb_configuration *c,
+ struct usb_function *f)
+{
+ struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
+ struct f_usb9pfs_opts *opts;
+ struct usb_composite_dev *cdev = c->cdev;
+ int ret;
+ int id;
+
+ /* allocate interface ID(s) */
+ id = usb_interface_id(c, f);
+ if (id < 0)
+ return id;
+ usb9pfs_intf.bInterfaceNumber = id;
+
+ id = usb_string_id(cdev);
+ if (id < 0)
+ return id;
+ strings_usb9pfs[0].id = id;
+ usb9pfs_intf.iInterface = id;
+
+ /* allocate endpoints */
+ usb9pfs->in_ep = usb_ep_autoconfig(cdev->gadget,
+ &fs_usb9pfs_source_desc);
+ if (!usb9pfs->in_ep)
+ goto autoconf_fail;
+
+ usb9pfs->out_ep = usb_ep_autoconfig(cdev->gadget,
+ &fs_usb9pfs_sink_desc);
+ if (!usb9pfs->out_ep)
+ goto autoconf_fail;
+
+ /* support high speed hardware */
+ hs_usb9pfs_source_desc.bEndpointAddress =
+ fs_usb9pfs_source_desc.bEndpointAddress;
+ hs_usb9pfs_sink_desc.bEndpointAddress =
+ fs_usb9pfs_sink_desc.bEndpointAddress;
+
+ /* support super speed hardware */
+ ss_usb9pfs_source_desc.bEndpointAddress =
+ fs_usb9pfs_source_desc.bEndpointAddress;
+ ss_usb9pfs_sink_desc.bEndpointAddress =
+ fs_usb9pfs_sink_desc.bEndpointAddress;
+
+ ret = usb_assign_descriptors(f, fs_usb9pfs_descs, hs_usb9pfs_descs,
+ ss_usb9pfs_descs, ss_usb9pfs_descs);
+ if (ret)
+ return ret;
+
+ opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst);
+ opts->dev->usb9pfs = usb9pfs;
+
+ dev_dbg(&cdev->gadget->dev, "%s speed %s: IN/%s, OUT/%s\n",
+ (gadget_is_superspeed(c->cdev->gadget) ? "super" :
+ (gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")),
+ f->name, usb9pfs->in_ep->name, usb9pfs->out_ep->name);
+
+ return 0;
+
+autoconf_fail:
+ ERROR(cdev, "%s: can't autoconfigure on %s\n",
+ f->name, cdev->gadget->name);
+ return -ENODEV;
+}
+
+static void usb9pfs_free_func(struct usb_function *f)
+{
+ struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
+ struct f_usb9pfs_opts *opts;
+
+ kfree(usb9pfs);
+
+ opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst);
+
+ mutex_lock(&opts->lock);
+ opts->refcnt--;
+ mutex_unlock(&opts->lock);
+
+ usb_free_all_descriptors(f);
+}
+
+static int usb9pfs_set_alt(struct usb_function *f,
+ unsigned int intf, unsigned int alt)
+{
+ return 0;
+}
+
+static void usb9pfs_disable(struct usb_function *f)
+{
+ struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
+ struct p9_req_t *req;
+
+ spin_lock(&usb9pfs->req_lock);
+
+ req = usb9pfs->p9_tx_req;
+
+ if (!req->t_err)
+ req->t_err = -ECONNRESET;
+ p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR);
+
+ spin_unlock(&usb9pfs->req_lock);
+}
+
+static struct usb_function *usb9pfs_alloc(struct usb_function_instance *fi)
+{
+ struct f_usb9pfs_opts *usb9pfs_opts;
+ struct f_usb9pfs *usb9pfs;
+
+ usb9pfs = kzalloc(sizeof(*usb9pfs), GFP_KERNEL);
+ if (!usb9pfs)
+ return ERR_PTR(-ENOMEM);
+
+ usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
+
+ mutex_lock(&usb9pfs_opts->lock);
+ usb9pfs_opts->refcnt++;
+ mutex_unlock(&usb9pfs_opts->lock);
+
+ usb9pfs->buflen = usb9pfs_opts->buflen;
+
+ usb9pfs->function.name = "usb9pfs";
+ usb9pfs->function.bind = usb9pfs_func_bind;
+ usb9pfs->function.set_alt = usb9pfs_set_alt;
+ usb9pfs->function.disable = usb9pfs_disable;
+ usb9pfs->function.strings = usb9pfs_strings;
+
+ usb9pfs->function.free_func = usb9pfs_free_func;
+
+ return &usb9pfs->function;
+}
+
+static inline struct f_usb9pfs_opts *to_f_usb9pfs_opts(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_usb9pfs_opts,
+ func_inst.group);
+}
+
+static inline struct f_usb9pfs_opts *fi_to_f_usb9pfs_opts(struct usb_function_instance *fi)
+{
+ return container_of(fi, struct f_usb9pfs_opts, func_inst);
+}
+
+static void usb9pfs_attr_release(struct config_item *item)
+{
+ struct f_usb9pfs_opts *usb9pfs_opts = to_f_usb9pfs_opts(item);
+
+ usb_put_function_instance(&usb9pfs_opts->func_inst);
+}
+
+static struct configfs_item_operations usb9pfs_item_ops = {
+ .release = usb9pfs_attr_release,
+};
+
+static ssize_t f_usb9pfs_opts_buflen_show(struct config_item *item, char *page)
+{
+ struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = sprintf(page, "%d\n", opts->buflen);
+ mutex_unlock(&opts->lock);
+
+ return result;
+}
+
+static ssize_t f_usb9pfs_opts_buflen_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
+ int ret;
+ u32 num;
+
+ mutex_lock(&opts->lock);
+ if (opts->refcnt) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ ret = kstrtou32(page, 0, &num);
+ if (ret)
+ goto end;
+
+ opts->buflen = num;
+ ret = len;
+end:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+CONFIGFS_ATTR(f_usb9pfs_opts_, buflen);
+
+static struct configfs_attribute *usb9pfs_attrs[] = {
+ &f_usb9pfs_opts_attr_buflen,
+ NULL,
+};
+
+static const struct config_item_type usb9pfs_func_type = {
+ .ct_item_ops = &usb9pfs_item_ops,
+ .ct_attrs = usb9pfs_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct f_usb9pfs_dev *_usb9pfs_do_find_dev(const char *tag)
+{
+ struct f_usb9pfs_dev *usb9pfs_dev;
+ struct f_usb9pfs_dev *tmp;
+
+ if (!tag)
+ return NULL;
+
+ list_for_each_entry_safe(usb9pfs_dev, tmp, &usbg_instance_list, usb9pfs_instance) {
+ if (strcmp(usb9pfs_dev->tag, tag) == 0)
+ return usb9pfs_dev;
+ }
+
+ return NULL;
+}
+
+static int usb9pfs_tag_instance(struct f_usb9pfs_dev *dev, const char *tag)
+{
+ struct f_usb9pfs_dev *existing;
+ int ret = 0;
+
+ mutex_lock(&usb9pfs_lock);
+ existing = _usb9pfs_do_find_dev(tag);
+ if (!existing)
+ strscpy(dev->tag, tag, ARRAY_SIZE(dev->tag));
+ else if (existing != dev)
+ ret = -EBUSY;
+ mutex_unlock(&usb9pfs_lock);
+
+ return ret;
+}
+
+static int usb9pfs_set_inst_tag(struct usb_function_instance *fi, const char *tag)
+{
+ if (strlen(tag) >= sizeof_field(struct f_usb9pfs_dev, tag))
+ return -ENAMETOOLONG;
+ return usb9pfs_tag_instance(fi_to_f_usb9pfs_opts(fi)->dev, tag);
+}
+
+static void usb9pfs_free_instance(struct usb_function_instance *fi)
+{
+ struct f_usb9pfs_opts *usb9pfs_opts;
+
+ usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
+ kfree(usb9pfs_opts);
+}
+
+static struct usb_function_instance *usb9pfs_alloc_instance(void)
+{
+ struct f_usb9pfs_opts *usb9pfs_opts;
+ struct f_usb9pfs_dev *dev;
+
+ usb9pfs_opts = kzalloc(sizeof(*usb9pfs_opts), GFP_KERNEL);
+ if (!usb9pfs_opts)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_init(&usb9pfs_opts->lock);
+
+ usb9pfs_opts->func_inst.set_inst_name = usb9pfs_set_inst_tag;
+ usb9pfs_opts->func_inst.free_func_inst = usb9pfs_free_instance;
+
+ usb9pfs_opts->buflen = DEFAULT_BUFLEN;
+
+ mutex_lock(&usb9pfs_lock);
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (IS_ERR(dev)) {
+ mutex_unlock(&usb9pfs_lock);
+ kfree(usb9pfs_opts);
+ return ERR_CAST(dev);
+ }
+ list_add_tail(&dev->usb9pfs_instance, &usbg_instance_list);
+ mutex_unlock(&usb9pfs_lock);
+
+ usb9pfs_opts->dev = dev;
+ dev->opts = usb9pfs_opts;
+
+ config_group_init_type_name(&usb9pfs_opts->func_inst.group, "",
+ &usb9pfs_func_type);
+
+ return &usb9pfs_opts->func_inst;
+}
+DECLARE_USB_FUNCTION(usb9pfs, usb9pfs_alloc_instance, usb9pfs_alloc);
+
+static int __init usb9pfs_modinit(void)
+{
+ int ret;
+
+ INIT_LIST_HEAD(&usbg_instance_list);
+
+ ret = usb_function_register(&usb9pfsusb_func);
+ if (!ret)
+ v9fs_register_trans(&p9_usbg_trans);
+
+ return ret;
+}
+
+static void __exit usb9pfs_modexit(void)
+{
+ usb_function_unregister(&usb9pfsusb_func);
+ v9fs_unregister_trans(&p9_usbg_trans);
+}
+
+module_init(usb9pfs_modinit);
+module_exit(usb9pfs_modexit);
+
+MODULE_ALIAS_9P("usbg");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("USB gadget 9pfs transport");
+MODULE_AUTHOR("Michael Grzeschik");

--
2.39.2


2024-04-30 01:51:34

by Alan Stern

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] usb: gadget: function: move u_f.h to include/linux/usb/

On Tue, Apr 30, 2024 at 01:33:26AM +0200, Michael Grzeschik wrote:
> We move the u_f.h header to include/linux/usb to be
> able to compile function drivers outside of the
> drivers/usb/gadget/function directory.
>
> Signed-off-by: Michael Grzeschik <[email protected]>

Given that you're moving a private header file to a public location,
don't you think it should now have a name that's more meaningful to
general kernel developers than "u_f.h"?

Alan Stern

2024-05-01 08:38:50

by Michael Grzeschik

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] usb: gadget: function: move u_f.h to include/linux/usb/

On Mon, Apr 29, 2024 at 09:51:20PM -0400, Alan Stern wrote:
>On Tue, Apr 30, 2024 at 01:33:26AM +0200, Michael Grzeschik wrote:
>> We move the u_f.h header to include/linux/usb to be
>> able to compile function drivers outside of the
>> drivers/usb/gadget/function directory.
>>
>> Signed-off-by: Michael Grzeschik <[email protected]>
>
>Given that you're moving a private header file to a public location,
>don't you think it should now have a name that's more meaningful to
>general kernel developers than "u_f.h"?

Fair point.

How about func_utils.h instead?

Michael Grzeschik

--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |


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2024-05-01 14:19:30

by Alan Stern

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] usb: gadget: function: move u_f.h to include/linux/usb/

On Wed, May 01, 2024 at 10:38:11AM +0200, Michael Grzeschik wrote:
> On Mon, Apr 29, 2024 at 09:51:20PM -0400, Alan Stern wrote:
> > On Tue, Apr 30, 2024 at 01:33:26AM +0200, Michael Grzeschik wrote:
> > > We move the u_f.h header to include/linux/usb to be
> > > able to compile function drivers outside of the
> > > drivers/usb/gadget/function directory.
> > >
> > > Signed-off-by: Michael Grzeschik <[email protected]>
> >
> > Given that you're moving a private header file to a public location,
> > don't you think it should now have a name that's more meaningful to
> > general kernel developers than "u_f.h"?
>
> Fair point.
>
> How about func_utils.h instead?

Yes, that would be a lot better. Especially if you put it in
include/linux/usb/gadget rather than include/linux/usb.

Thanks.

Alan Stern

2024-05-10 08:29:32

by Andrzej Pietrasiewicz

[permalink] [raw]
Subject: Re: [PATCH v4 3/3] tools: usb: p9_fwd: add usb gadget packet forwarder script

Hi Michael,

W dniu 30.04.2024 o 01:33, Michael Grzeschik pisze:
> This patch is adding an small python tool to forward 9pfs requests
> from the USB gadget to an existing 9pfs TCP server. Since currently all
> 9pfs servers lack support for the usb transport this tool is an useful
> helper to get started.
>
> Refer the Documentation section "USBG Example" in
> Documentation/filesystems/9p.rst on how to use it.
>
> Signed-off-by: Michael Grzeschik <[email protected]>
>
> ---
> v3 -> v4: -
> v2 -> v3: -
> v1 -> v2:
> - added usbg 9pfs detailed instructions to 9p.rst doc
> ---
> Documentation/filesystems/9p.rst | 32 +++++++
> tools/usb/p9_fwd.py | 194 +++++++++++++++++++++++++++++++++++++++
> 2 files changed, 226 insertions(+)
>
> diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst
> index 10cf79dc287f8..2467f1ea4a150 100644
> --- a/Documentation/filesystems/9p.rst
> +++ b/Documentation/filesystems/9p.rst
> @@ -67,6 +67,38 @@ To mount a 9p FS on a USB Host accessible via the gadget as root filesystem::
> where <device> is the tag associated by the usb gadget transport.
> It is defined by the configfs instance name.
>
> +USBG Example
> +============
> +
> +The USB host exports a filesystem, while the gadget on the USB device
> +side makes it mountable.
> +
> +Diod (9pfs server) and the forwarder are on the development host, where
> +the root filesystem is actually stored. The gadget is initialized during
> +boot (or later) on the embedded board. Then the forwarder will find it
> +on the USB bus and start forwarding requests.
> +
> +In this case the 9p requests come from the device and are handled by the
> +host. The reason is that USB device ports are normally not available on
> +PCs, so a connection in the other direction would not work.
> +
> +When using the usbg transport, for now there is no native usb host
> +service capable to handle the requests from the gadget driver. For
> +this we have to use the extra python tool p9_fwd.py from tools/usb.
> +
> +Just start the 9pfs capable network server like diod/nfs-ganesha e.g.:
> +
> + $ diod -f -n -d 0 -S -l 0.0.0.0:9999 -e $PWD
> +
> +Then start the python transport:
> +
> + $ python $kernel_dir/tools/usb/p9_fwd.py -p 9999
> +
> +After that the gadget driver can be used as described above.
> +
> +One use-case is to use it as an alternative to NFS root booting during
> +the development of embedded Linux devices.
> +
> Options
> =======
>
> diff --git a/tools/usb/p9_fwd.py b/tools/usb/p9_fwd.py
> new file mode 100755
> index 0000000000000..95208df11abef
> --- /dev/null
> +++ b/tools/usb/p9_fwd.py
> @@ -0,0 +1,194 @@
> +#!/usr/bin/env python3
> +# SPDX-License-Identifier: GPL-2.0
> +
> +import argparse
> +import errno
> +import logging
> +import socket
> +import struct
> +import sys
> +import time
> +
> +import usb.core
> +import usb.util
> +
> +
> +class Forwarder:
> + HEXDUMP_FILTER = (
> + "".join(chr(x).isprintable() and chr(x) or "." for x in range(128)) + "." * 128
> + )
> +
> + @staticmethod
> + def _log_hexdump(data):
> + if not logging.root.isEnabledFor(logging.TRACE):
> + return
> + L = 16
> + for c in range(0, len(data), L):
> + chars = data[c : c + L]
> + dump = " ".join(f"{x:02x}" for x in chars)
> + printable = "".join(HEXDUMP_FILTER[x] for x in chars)
> + line = f"{c:08x} {dump:{L*3}s} |{printable:{L}s}|"
> + logging.root.log(logging.TRACE, "%s", line)
> +
> + def __init__(self, server):
> + self.stats = {
> + "c2s packets": 0,
> + "c2s bytes": 0,
> + "s2c packets": 0,
> + "s2c bytes": 0,
> + }
> + self.stats_logged = time.monotonic()
> +
> + dev = usb.core.find(idVendor=0x1D6B, idProduct=0x0109)

Is this idProduct an assigned number? I can't find it in
http://www.linux-usb.org/usb.ids. The "9" is obviously a pun on 9pfs,
a nice trick and it would make sense.

However, given composition with configfs there's no guarantee that 9pfs will be
the only USB gadget function present, and so it is not quite clear that Linux
Foundation's vendor and product ids are always appropriate. What's more, when
you are not going to the market with products you can use whatever ids you
please for your own use.

Given the above, I'd love these two (idVendor and idProduct) to be commandline
parameters of this script. My user story: whenever I created a gadget with
configfs it had different ids than the above and this script wouldn't work.

Regards,

Andrzej

> + if dev is None:
> + raise ValueError("Device not found")
> +
> + logging.info(f"found device: {dev.bus}/{dev.address}")
> +
> + # dev.set_configuration() is not necessary since g_multi has only one
> + usb9pfs = None
> + # g_multi adds 9pfs as last interface
> + cfg = dev.get_active_configuration()
> + for intf in cfg:
> + # we have to detach the usb-storage driver from multi gadget since
> + # stall option could be set, which will lead to spontaneous port
> + # resets and our transfers will run dead
> + if intf.bInterfaceClass == 0x08:
> + if dev.is_kernel_driver_active(intf.bInterfaceNumber):
> + dev.detach_kernel_driver(intf.bInterfaceNumber)
> +
> + if (
> + intf.bInterfaceClass == 0xFF
> + and intf.bInterfaceSubClass == 0xFF
> + and intf.bInterfaceProtocol == 0x09
> + ):
> + usb9pfs = intf
> + if usb9pfs is None:
> + raise ValueError("Interface not found")
> +
> + logging.info(f"claiming interface:\n{usb9pfs}")
> + usb.util.claim_interface(dev, usb9pfs.bInterfaceNumber)
> + ep_out = usb.util.find_descriptor(
> + usb9pfs,
> + custom_match=lambda e: usb.util.endpoint_direction(e.bEndpointAddress)
> + == usb.util.ENDPOINT_OUT,
> + )
> + assert ep_out is not None
> + ep_in = usb.util.find_descriptor(
> + usb9pfs,
> + custom_match=lambda e: usb.util.endpoint_direction(e.bEndpointAddress)
> + == usb.util.ENDPOINT_IN,
> + )
> + assert ep_in is not None
> + logging.info(f"interface claimed")
> +
> + self.ep_out = ep_out
> + self.ep_in = ep_in
> + self.dev = dev
> +
> + # create and connect socket
> + self.s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
> + self.s.connect(server)
> +
> + logging.info(f"connected to server")
> +
> + def c2s(self):
> + """forward a request from the USB client to the TCP server"""
> + data = None
> + while data is None:
> + try:
> + logging.log(logging.TRACE, "c2s: reading")
> + data = self.ep_in.read(self.ep_in.wMaxPacketSize)
> + except usb.core.USBTimeoutError:
> + logging.log(logging.TRACE, "c2s: reading timed out")
> + continue
> + except usb.core.USBError as e:
> + if e.errno == errno.EIO:
> + logging.debug("c2s: reading failed with %s, retrying", repr(e))
> + time.sleep(0.5)
> + continue
> + else:
> + logging.error("c2s: reading failed with %s, aborting", repr(e))
> + raise
> + size = struct.unpack("<I", data[:4])[0]
> + while len(data) < size:
> + data += self.ep_in.read(size - len(data))
> + logging.log(logging.TRACE, "c2s: writing")
> + self._log_hexdump(data)
> + self.s.send(data)
> + logging.debug("c2s: forwarded %i bytes", size)
> + self.stats["c2s packets"] += 1
> + self.stats["c2s bytes"] += size
> +
> + def s2c(self):
> + """forward a response from the TCP server to the USB client"""
> + logging.log(logging.TRACE, "s2c: reading")
> + data = self.s.recv(4)
> + size = struct.unpack("<I", data[:4])[0]
> + while len(data) < size:
> + data += self.s.recv(size - len(data))
> + logging.log(logging.TRACE, "s2c: writing")
> + self._log_hexdump(data)
> + while data:
> + written = self.ep_out.write(data)
> + assert written > 0
> + data = data[written:]
> + if size % self.ep_out.wMaxPacketSize == 0:
> + logging.log(logging.TRACE, "sending zero length packet")
> + self.ep_out.write(b"")
> + logging.debug("s2c: forwarded %i bytes", size)
> + self.stats["s2c packets"] += 1
> + self.stats["s2c bytes"] += size
> +
> + def log_stats(self):
> + logging.info("statistics:")
> + for k, v in self.stats.items():
> + logging.info(f" {k+':':14s} {v}")
> +
> + def log_stats_interval(self, interval=5):
> + if (time.monotonic() - self.stats_logged) < interval:
> + return
> +
> + self.log_stats()
> + self.stats_logged = time.monotonic()
> +
> +
> +def main():
> + parser = argparse.ArgumentParser(
> + description="Forward 9PFS requests from USB to TCP",
> + )
> +
> + parser.add_argument(
> + "-s", "--server", type=str, default="127.0.0.1", help="server hostname"
> + )
> + parser.add_argument("-p", "--port", type=int, default=564, help="server port")
> + parser.add_argument("-v", "--verbose", action="count", default=0)
> +
> + args = parser.parse_args()
> +
> + logging.TRACE = logging.DEBUG - 5
> + logging.addLevelName(logging.TRACE, "TRACE")
> +
> + if args.verbose >= 2:
> + level = logging.TRACE
> + elif args.verbose:
> + level = logging.DEBUG
> + else:
> + level = logging.INFO
> + logging.basicConfig(
> + level=level, format="%(asctime)-15s %(levelname)-8s %(message)s"
> + )
> +
> + f = Forwarder(server=(args.server, args.port))
> +
> + try:
> + while True:
> + f.c2s()
> + f.s2c()
> + f.log_stats_interval()
> + finally:
> + f.log_stats()
> +
> +
> +if __name__ == "__main__":
> + main()
>


2024-05-10 08:32:28

by Andrzej Pietrasiewicz

[permalink] [raw]
Subject: Re: [PATCH v4 3/3] tools: usb: p9_fwd: add usb gadget packet forwarder script

Hi Michael,

W dniu 10.05.2024 o 10:29, Andrzej Pietrasiewicz pisze:
> Hi Michael,
>
> W dniu 30.04.2024 o 01:33, Michael Grzeschik pisze:
>> This patch is adding an small python tool to forward 9pfs requests
>> from the USB gadget to an existing 9pfs TCP server. Since currently all
>> 9pfs servers lack support for the usb transport this tool is an useful
>> helper to get started.
>>
>> Refer the Documentation section "USBG Example" in
>> Documentation/filesystems/9p.rst on how to use it.
>>
>> Signed-off-by: Michael Grzeschik <[email protected]>
>>
>> ---
>> v3 -> v4: -
>> v2 -> v3: -
>> v1 -> v2:
>>    - added usbg 9pfs detailed instructions to 9p.rst doc
>> ---
>>   Documentation/filesystems/9p.rst |  32 +++++++
>>   tools/usb/p9_fwd.py              | 194 +++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 226 insertions(+)
>>
>> diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst
>> index 10cf79dc287f8..2467f1ea4a150 100644
>> --- a/Documentation/filesystems/9p.rst
>> +++ b/Documentation/filesystems/9p.rst
>> @@ -67,6 +67,38 @@ To mount a 9p FS on a USB Host accessible via the gadget as
>> root filesystem::
>>   where <device> is the tag associated by the usb gadget transport.
>>   It is defined by the configfs instance name.
>> +USBG Example
>> +============
>> +
>> +The USB host exports a filesystem, while the gadget on the USB device
>> +side makes it mountable.
>> +
>> +Diod (9pfs server) and the forwarder are on the development host, where
>> +the root filesystem is actually stored. The gadget is initialized during
>> +boot (or later) on the embedded board. Then the forwarder will find it
>> +on the USB bus and start forwarding requests.
>> +
>> +In this case the 9p requests come from the device and are handled by the
>> +host. The reason is that USB device ports are normally not available on
>> +PCs, so a connection in the other direction would not work.
>> +
>> +When using the usbg transport, for now there is no native usb host
>> +service capable to handle the requests from the gadget driver. For
>> +this we have to use the extra python tool p9_fwd.py from tools/usb.
>> +
>> +Just start the 9pfs capable network server like diod/nfs-ganesha e.g.:
>> +
>> +    $ diod -f -n -d 0 -S -l 0.0.0.0:9999 -e $PWD
>> +
>> +Then start the python transport:
>> +
>> +    $ python $kernel_dir/tools/usb/p9_fwd.py -p 9999
>> +
>> +After that the gadget driver can be used as described above.
>> +
>> +One use-case is to use it as an alternative to NFS root booting during
>> +the development of embedded Linux devices.
>> +
>>   Options
>>   =======
>> diff --git a/tools/usb/p9_fwd.py b/tools/usb/p9_fwd.py
>> new file mode 100755
>> index 0000000000000..95208df11abef
>> --- /dev/null
>> +++ b/tools/usb/p9_fwd.py
>> @@ -0,0 +1,194 @@
>> +#!/usr/bin/env python3
>> +# SPDX-License-Identifier: GPL-2.0
>> +
>> +import argparse
>> +import errno
>> +import logging
>> +import socket
>> +import struct
>> +import sys
>> +import time
>> +
>> +import usb.core
>> +import usb.util
>> +
>> +
>> +class Forwarder:
>> +    HEXDUMP_FILTER = (
>> +        "".join(chr(x).isprintable() and chr(x) or "." for x in range(128)) +
>> "." * 128
>> +    )
>> +
>> +    @staticmethod
>> +    def _log_hexdump(data):
>> +        if not logging.root.isEnabledFor(logging.TRACE):
>> +            return
>> +        L = 16
>> +        for c in range(0, len(data), L):
>> +            chars = data[c : c + L]
>> +            dump = " ".join(f"{x:02x}" for x in chars)
>> +            printable = "".join(HEXDUMP_FILTER[x] for x in chars)
>> +            line = f"{c:08x}  {dump:{L*3}s} |{printable:{L}s}|"
>> +            logging.root.log(logging.TRACE, "%s", line)
>> +
>> +    def __init__(self, server):
>> +        self.stats = {
>> +            "c2s packets": 0,
>> +            "c2s bytes": 0,
>> +            "s2c packets": 0,
>> +            "s2c bytes": 0,
>> +        }
>> +        self.stats_logged = time.monotonic()
>> +
>> +        dev = usb.core.find(idVendor=0x1D6B, idProduct=0x0109)
>
> Is this idProduct an assigned number? I can't find it in
> http://www.linux-usb.org/usb.ids. The "9" is obviously a pun on 9pfs,
> a nice trick and it would make sense.
>
> However, given composition with configfs there's no guarantee that 9pfs will be
> the only USB gadget function present, and so it is not quite clear that Linux
> Foundation's vendor and product ids are always appropriate. What's more, when
> you are not going to the market with products you can use whatever ids you
> please for your own use.
>
> Given the above, I'd love these two (idVendor and idProduct) to be commandline
> parameters of this script. My user story: whenever I created a gadget with
> configfs it had different ids than the above and this script wouldn't work.

And actually it is perfectly possible to have more than one USB device with
_the same_ vendor and product ids connected. How would this script behave if
that's the case?

Andrzej

>
> Regards,
>
> Andrzej
>
>> +        if dev is None:
>> +            raise ValueError("Device not found")
>> +
>> +        logging.info(f"found device: {dev.bus}/{dev.address}")
>> +
>> +        # dev.set_configuration() is not necessary since g_multi has only one
>> +        usb9pfs = None
>> +        # g_multi adds 9pfs as last interface
>> +        cfg = dev.get_active_configuration()
>> +        for intf in cfg:
>> +            # we have to detach the usb-storage driver from multi gadget since
>> +            # stall option could be set, which will lead to spontaneous port
>> +            # resets and our transfers will run dead
>> +            if intf.bInterfaceClass == 0x08:
>> +                if dev.is_kernel_driver_active(intf.bInterfaceNumber):
>> +                    dev.detach_kernel_driver(intf.bInterfaceNumber)
>> +
>> +            if (
>> +                intf.bInterfaceClass == 0xFF
>> +                and intf.bInterfaceSubClass == 0xFF
>> +                and intf.bInterfaceProtocol == 0x09
>> +            ):
>> +                usb9pfs = intf
>> +        if usb9pfs is None:
>> +            raise ValueError("Interface not found")
>> +
>> +        logging.info(f"claiming interface:\n{usb9pfs}")
>> +        usb.util.claim_interface(dev, usb9pfs.bInterfaceNumber)
>> +        ep_out = usb.util.find_descriptor(
>> +            usb9pfs,
>> +            custom_match=lambda e:
>> usb.util.endpoint_direction(e.bEndpointAddress)
>> +            == usb.util.ENDPOINT_OUT,
>> +        )
>> +        assert ep_out is not None
>> +        ep_in = usb.util.find_descriptor(
>> +            usb9pfs,
>> +            custom_match=lambda e:
>> usb.util.endpoint_direction(e.bEndpointAddress)
>> +            == usb.util.ENDPOINT_IN,
>> +        )
>> +        assert ep_in is not None
>> +        logging.info(f"interface claimed")
>> +
>> +        self.ep_out = ep_out
>> +        self.ep_in = ep_in
>> +        self.dev = dev
>> +
>> +        # create and connect socket
>> +        self.s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
>> +        self.s.connect(server)
>> +
>> +        logging.info(f"connected to server")
>> +
>> +    def c2s(self):
>> +        """forward a request from the USB client to the TCP server"""
>> +        data = None
>> +        while data is None:
>> +            try:
>> +                logging.log(logging.TRACE, "c2s: reading")
>> +                data = self.ep_in.read(self.ep_in.wMaxPacketSize)
>> +            except usb.core.USBTimeoutError:
>> +                logging.log(logging.TRACE, "c2s: reading timed out")
>> +                continue
>> +            except usb.core.USBError as e:
>> +                if e.errno == errno.EIO:
>> +                    logging.debug("c2s: reading failed with %s, retrying",
>> repr(e))
>> +                    time.sleep(0.5)
>> +                    continue
>> +                else:
>> +                    logging.error("c2s: reading failed with %s, aborting",
>> repr(e))
>> +                    raise
>> +        size = struct.unpack("<I", data[:4])[0]
>> +        while len(data) < size:
>> +            data += self.ep_in.read(size - len(data))
>> +        logging.log(logging.TRACE, "c2s: writing")
>> +        self._log_hexdump(data)
>> +        self.s.send(data)
>> +        logging.debug("c2s: forwarded %i bytes", size)
>> +        self.stats["c2s packets"] += 1
>> +        self.stats["c2s bytes"] += size
>> +
>> +    def s2c(self):
>> +        """forward a response from the TCP server to the USB client"""
>> +        logging.log(logging.TRACE, "s2c: reading")
>> +        data = self.s.recv(4)
>> +        size = struct.unpack("<I", data[:4])[0]
>> +        while len(data) < size:
>> +            data += self.s.recv(size - len(data))
>> +        logging.log(logging.TRACE, "s2c: writing")
>> +        self._log_hexdump(data)
>> +        while data:
>> +            written = self.ep_out.write(data)
>> +            assert written > 0
>> +            data = data[written:]
>> +        if size % self.ep_out.wMaxPacketSize == 0:
>> +            logging.log(logging.TRACE, "sending zero length packet")
>> +            self.ep_out.write(b"")
>> +        logging.debug("s2c: forwarded %i bytes", size)
>> +        self.stats["s2c packets"] += 1
>> +        self.stats["s2c bytes"] += size
>> +
>> +    def log_stats(self):
>> +        logging.info("statistics:")
>> +        for k, v in self.stats.items():
>> +            logging.info(f"  {k+':':14s} {v}")
>> +
>> +    def log_stats_interval(self, interval=5):
>> +        if (time.monotonic() - self.stats_logged) < interval:
>> +            return
>> +
>> +        self.log_stats()
>> +        self.stats_logged = time.monotonic()
>> +
>> +
>> +def main():
>> +    parser = argparse.ArgumentParser(
>> +        description="Forward 9PFS requests from USB to TCP",
>> +    )
>> +
>> +    parser.add_argument(
>> +        "-s", "--server", type=str, default="127.0.0.1", help="server hostname"
>> +    )
>> +    parser.add_argument("-p", "--port", type=int, default=564, help="server
>> port")
>> +    parser.add_argument("-v", "--verbose", action="count", default=0)
>> +
>> +    args = parser.parse_args()
>> +
>> +    logging.TRACE = logging.DEBUG - 5
>> +    logging.addLevelName(logging.TRACE, "TRACE")
>> +
>> +    if args.verbose >= 2:
>> +        level = logging.TRACE
>> +    elif args.verbose:
>> +        level = logging.DEBUG
>> +    else:
>> +        level = logging.INFO
>> +    logging.basicConfig(
>> +        level=level, format="%(asctime)-15s %(levelname)-8s %(message)s"
>> +    )
>> +
>> +    f = Forwarder(server=(args.server, args.port))
>> +
>> +    try:
>> +        while True:
>> +            f.c2s()
>> +            f.s2c()
>> +            f.log_stats_interval()
>> +    finally:
>> +        f.log_stats()
>> +
>> +
>> +if __name__ == "__main__":
>> +    main()
>>
>


2024-05-10 09:26:10

by Andrzej Pietrasiewicz

[permalink] [raw]
Subject: Re: [PATCH v4 2/3] net/9p/usbg: Add new usb gadget function transport

Hi Michael,

W dniu 30.04.2024 o 01:33, Michael Grzeschik pisze:
> Add the new gadget function for 9pfs transport. This function is
> defining an simple 9pfs transport interface that consists of one in and
> one out endpoint. The endpoints transmit and receive the 9pfs protocol
> payload when mounting a 9p filesystem over usb.
>
> Signed-off-by: Michael Grzeschik <[email protected]>
>
> ---
> v3 -> v4:
> - implemented conn_cancel

I tried this scenario:

1) run all the components and have 9pfs up and running
2) stop the forwarder
3) umount -f at the gadget side - this indeed succeeds now in v4
4) start the forwarder again
5) mount at the gadget side - this hangs.

Did this scenario work for you?

Regards,

Andrzej

> - moved from mount_tag to device name like ffs does
> - renamed function_list to usb9pfs_instance
> - renamed usbg_function_list to usb9pfs_instance_list
> - renamed rx/tx_fill to queue_rx/tx
> - added use of retvals
> - added locking comment over usb9pfs_transmit
> - using if_else instead of two pathed switch calls
> - fixed return values of completion handler
> - using void pointer as parameter in rx_header
> - added a missed req_put in rx_header
> - removed extra disable function but call disable_ep directly
> - repaired several return values
> - remove the suspicious disable / enable path in usbg_create
> v2 -> v3: -
> v1 -> v2:
> - move the driver to net/9p/trans_usbg.c
> - fixed the commit title
> - fix %zu usage in p9_debug for size_t type
> - define functions static that are only used localy
> - return 0 in alloc_requests
> - use id_alloc_max instead of ida_simple_get
> - call ida_free in usb9pfs_free_func
> - call kfree for usb9pfs->tag and usb9pfs in usb9pfs_free_func
> - add MODULE_ALIAS_9P to load this module automatic when mounting
> - improved the documentation
> - added depends on USB_GADGET in Kconfig
> ---
> Documentation/filesystems/9p.rst | 17 +-
> net/9p/Kconfig | 6 +
> net/9p/Makefile | 4 +
> net/9p/trans_usbg.c | 983 +++++++++++++++++++++++++++++++++++++++
> 4 files changed, 1009 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst
> index 1e0e0bb6fdf91..10cf79dc287f8 100644
> --- a/Documentation/filesystems/9p.rst
> +++ b/Documentation/filesystems/9p.rst
> @@ -48,11 +48,25 @@ For server running on QEMU host with virtio transport::
>
> mount -t 9p -o trans=virtio <mount_tag> /mnt/9
>
> -where mount_tag is the tag associated by the server to each of the exported
> +where mount_tag is the tag generated by the server to each of the exported
> mount points. Each 9P export is seen by the client as a virtio device with an
> associated "mount_tag" property. Available mount tags can be
> seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
>
> +USBG Usage
> +==========
> +
> +To mount a 9p FS on a USB Host accessible via the gadget at runtime::
> +
> + mount -t 9p -o trans=usbg,aname=/path/to/fs <device> /mnt/9
> +
> +To mount a 9p FS on a USB Host accessible via the gadget as root filesystem::
> +
> + root=<device> rootfstype=9p rootflags=trans=usbg,cache=loose,uname=root,access=0,dfltuid=0,dfltgid=0,aname=/path/to/rootfs
> +
> +where <device> is the tag associated by the usb gadget transport.
> +It is defined by the configfs instance name.
> +
> Options
> =======
>
> @@ -68,6 +82,7 @@ Options
> virtio connect to the next virtio channel available
> (from QEMU with trans_virtio module)
> rdma connect to a specified RDMA channel
> + usbg connect to a specified usb gadget channel
> ======== ============================================
>
> uname=name user name to attempt mount as on the remote server. The
> diff --git a/net/9p/Kconfig b/net/9p/Kconfig
> index 00ebce9e5a657..c3d357eb8bb37 100644
> --- a/net/9p/Kconfig
> +++ b/net/9p/Kconfig
> @@ -39,6 +39,12 @@ config NET_9P_XEN
> This builds support for a transport for 9pfs between
> two Xen domains.
>
> +config NET_9P_USBG
> + bool "9P USB Gadget Transport"
> + depends on USB_GADGET
> + help
> + This builds support for a transport for 9pfs over
> + usb gadget.
>
> config NET_9P_RDMA
> depends on INET && INFINIBAND && INFINIBAND_ADDR_TRANS
> diff --git a/net/9p/Makefile b/net/9p/Makefile
> index 1df9b344c30bd..22794a451c3f7 100644
> --- a/net/9p/Makefile
> +++ b/net/9p/Makefile
> @@ -4,6 +4,7 @@ obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
> obj-$(CONFIG_NET_9P_XEN) += 9pnet_xen.o
> obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o
> obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
> +obj-$(CONFIG_NET_9P_USBG) += 9pnet_usbg.o
>
> 9pnet-objs := \
> mod.o \
> @@ -23,3 +24,6 @@ obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
>
> 9pnet_rdma-objs := \
> trans_rdma.o \
> +
> +9pnet_usbg-objs := \
> + trans_usbg.o \
> diff --git a/net/9p/trans_usbg.c b/net/9p/trans_usbg.c
> new file mode 100644
> index 0000000000000..bc440033cbe68
> --- /dev/null
> +++ b/net/9p/trans_usbg.c
> @@ -0,0 +1,983 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * trans_usbg.c - USB peripheral usb9pfs configuration driver and transport.
> + *
> + * Copyright (C) 2024 Michael Grzeschik <[email protected]>
> + */
> +
> +/* Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs
> + * transport to mount host exported filesystem via usb gadget.
> + */
> +
> +/* +--------------------------+ | +--------------------------+
> + * | 9PFS mounting client | | | 9PFS exporting server |
> + * SW | | | | |
> + * | (this:trans_usbg) | | |(e.g. diod or nfs-ganesha)|
> + * +-------------^------------+ | +-------------^------------+
> + * | | |
> + * ------------------|------------------------------------|-------------
> + * | | |
> + * +-------------v------------+ | +-------------v------------+
> + * | | | | |
> + * HW | USB Device Controller <---------> USB Host Controller |
> + * | | | | |
> + * +--------------------------+ | +--------------------------+
> + */
> +
> +#include <linux/slab.h>
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/err.h>
> +#include <linux/usb/composite.h>
> +#include <linux/usb/u_f.h>
> +
> +#include <net/9p/9p.h>
> +#include <net/9p/client.h>
> +#include <net/9p/transport.h>
> +
> +#define DEFAULT_BUFLEN 16384
> +
> +struct f_usb9pfs {
> + struct p9_client *client;
> +
> + struct p9_req_t *p9_tx_req;
> +
> + struct list_head tx_req_list;
> +
> + /* 9p request lock for en/dequeue */
> + spinlock_t lock;
> + /* usb request lock for en/dequeue */
> + spinlock_t req_lock;
> +
> + struct usb_request *in_req;
> + struct usb_request *out_req;
> +
> + struct usb_ep *in_ep;
> + struct usb_ep *out_ep;
> +
> + unsigned int buflen;
> +
> + struct usb_function function;
> +};
> +
> +static inline struct f_usb9pfs *func_to_usb9pfs(struct usb_function *f)
> +{
> + return container_of(f, struct f_usb9pfs, function);
> +}
> +
> +struct f_usb9pfs_opts {
> + struct usb_function_instance func_inst;
> + unsigned int buflen;
> +
> + struct f_usb9pfs_dev *dev;
> +
> + /* Read/write access to configfs attributes is handled by configfs.
> + *
> + * This is to protect the data from concurrent access by read/write
> + * and create symlink/remove symlink.
> + */
> + struct mutex lock;
> + int refcnt;
> +};
> +
> +struct f_usb9pfs_dev {
> + struct f_usb9pfs *usb9pfs;
> + struct f_usb9pfs_opts *opts;
> + char tag[41];
> + bool inuse;
> +
> + struct list_head usb9pfs_instance;
> +};
> +
> +static DEFINE_MUTEX(usb9pfs_lock);
> +static struct list_head usbg_instance_list;
> +
> +static int usb9pfs_queue_tx(struct f_usb9pfs *usb9pfs, struct usb_request *req,
> + gfp_t gfp_flags)
> +{
> + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
> + int ret = -ENOMEM;
> +
> + if (!(usb9pfs->p9_tx_req->tc.size % usb9pfs->in_ep->maxpacket))
> + req->zero = 1;
> +
> + req->buf = usb9pfs->p9_tx_req->tc.sdata;
> + req->length = usb9pfs->p9_tx_req->tc.size;
> +
> + dev_dbg(&cdev->gadget->dev, "%s usb9pfs send --> %d/%d, zero: %d\n",
> + usb9pfs->in_ep->name, req->actual, req->length, req->zero);
> +
> + ret = usb_ep_queue(usb9pfs->in_ep, req, gfp_flags);
> +
> + dev_dbg(&cdev->gadget->dev, "tx submit --> %d\n", ret);
> +
> + return ret;
> +}
> +
> +static int usb9pfs_queue_rx(struct f_usb9pfs *usb9pfs, struct usb_request *req,
> + gfp_t gfp_flags)
> +{
> + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
> + int ret = -ENOMEM;
> +
> + ret = usb_ep_queue(usb9pfs->out_ep, req, gfp_flags);
> +
> + dev_dbg(&cdev->gadget->dev, "rx submit --> %d\n", ret);
> +
> + return ret;
> +}
> +
> +/* This needs to be called with usb9pfs->req_lock held */
> +static int usb9pfs_transmit(struct f_usb9pfs *usb9pfs)
> +{
> + struct p9_req_t *p9_req = NULL;
> + unsigned long flags;
> + int ret = 0;
> +
> + spin_lock_irqsave(&usb9pfs->lock, flags);
> +
> + if (usb9pfs->p9_tx_req) {
> + spin_unlock_irqrestore(&usb9pfs->lock, flags);
> + return -EBUSY;
> + }
> +
> + p9_req = list_first_entry_or_null(&usb9pfs->tx_req_list,
> + struct p9_req_t, req_list);
> + if (!p9_req) {
> + spin_unlock_irqrestore(&usb9pfs->lock, flags);
> + return -ENOENT;
> + }
> +
> + list_del(&p9_req->req_list);
> +
> + usb9pfs->p9_tx_req = p9_req;
> +
> + p9_req_get(usb9pfs->p9_tx_req);
> +
> + ret = usb9pfs_queue_tx(usb9pfs, usb9pfs->in_req, GFP_ATOMIC);
> +
> + spin_unlock_irqrestore(&usb9pfs->lock, flags);
> +
> + return ret;
> +}
> +
> +static void usb9pfs_tx_complete(struct usb_ep *ep, struct usb_request *req)
> +{
> + struct f_usb9pfs *usb9pfs = ep->driver_data;
> + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
> + int ret = 0;
> +
> + if (req->status) {
> + dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
> + ep->name, req->status, req->actual, req->length);
> + goto free_req;
> + }
> +
> + /* reset zero packages */
> + req->zero = 0;
> +
> + dev_dbg(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
> + ep->name, req->status, req->actual, req->length);
> +
> + spin_lock(&usb9pfs->req_lock);
> +
> + WRITE_ONCE(usb9pfs->p9_tx_req->status, REQ_STATUS_SENT);
> +
> + p9_req_put(usb9pfs->client, usb9pfs->p9_tx_req);
> +
> + ret = usb9pfs_queue_rx(usb9pfs, usb9pfs->out_req, GFP_ATOMIC);
> + if (ret) {
> + spin_unlock(&usb9pfs->req_lock);
> + goto free_req;
> + }
> +
> + spin_unlock(&usb9pfs->req_lock);
> +
> + return;
> +
> +free_req:
> + usb_ep_free_request(ep == usb9pfs->in_ep ?
> + usb9pfs->out_ep : usb9pfs->in_ep,
> + req->context);
> + free_ep_req(ep, req);
> +}
> +
> +static struct p9_req_t *usb9pfs_rx_header(struct f_usb9pfs *usb9pfs, void *buf)
> +{
> + struct p9_req_t *p9_rx_req;
> + struct p9_fcall rc;
> + int ret;
> +
> + /* start by reading header */
> + rc.sdata = buf;
> + rc.offset = 0;
> + rc.capacity = P9_HDRSZ;
> + rc.size = P9_HDRSZ;
> +
> + p9_debug(P9_DEBUG_TRANS, "mux %p got %zu bytes\n", usb9pfs,
> + rc.capacity - rc.offset);
> +
> + ret = p9_parse_header(&rc, &rc.size, NULL, NULL, 0);
> + if (ret) {
> + p9_debug(P9_DEBUG_ERROR,
> + "error parsing header: %d\n", ret);
> + return NULL;
> + }
> +
> + p9_debug(P9_DEBUG_TRANS,
> + "mux %p pkt: size: %d bytes tag: %d\n",
> + usb9pfs, rc.size, rc.tag);
> +
> + p9_rx_req = p9_tag_lookup(usb9pfs->client, rc.tag);
> + if (!p9_rx_req || p9_rx_req->status != REQ_STATUS_SENT) {
> + p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", rc.tag);
> + return NULL;
> + }
> +
> + if (rc.size > p9_rx_req->rc.capacity) {
> + p9_debug(P9_DEBUG_ERROR,
> + "requested packet size too big: %d for tag %d with capacity %zd\n",
> + rc.size, rc.tag, p9_rx_req->rc.capacity);
> + p9_req_put(usb9pfs->client, p9_rx_req);
> + return NULL;
> + }
> +
> + if (!p9_rx_req->rc.sdata) {
> + p9_debug(P9_DEBUG_ERROR,
> + "No recv fcall for tag %d (req %p), disconnecting!\n",
> + rc.tag, p9_rx_req);
> + p9_req_put(usb9pfs->client, p9_rx_req);
> + return NULL;
> + }
> +
> + return p9_rx_req;
> +}
> +
> +static void usb9pfs_rx_complete(struct usb_ep *ep, struct usb_request *req)
> +{
> + struct f_usb9pfs *usb9pfs = ep->driver_data;
> + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
> + struct p9_req_t *p9_rx_req;
> + unsigned long flags;
> + int ret = 0;
> +
> + if (req->status) {
> + dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
> + ep->name, req->status, req->actual, req->length);
> + goto free_req;
> + }
> +
> + spin_lock_irqsave(&usb9pfs->req_lock, flags);
> +
> + p9_rx_req = usb9pfs_rx_header(usb9pfs, req->buf);
> + if (!p9_rx_req) {
> + spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
> + goto free_req;
> + }
> +
> + memcpy(p9_rx_req->rc.sdata, req->buf, req->actual);
> +
> + p9_rx_req->rc.size = req->actual;
> +
> + p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_RCVD);
> + p9_req_put(usb9pfs->client, p9_rx_req);
> +
> + usb9pfs->p9_tx_req = NULL;
> +
> + ret = usb9pfs_transmit(usb9pfs);
> + if (ret) {
> + spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
> + return;
> + }
> +
> + spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
> +
> + return;
> +
> +free_req:
> + usb_ep_free_request(ep == usb9pfs->in_ep ?
> + usb9pfs->out_ep : usb9pfs->in_ep,
> + req->context);
> + free_ep_req(ep, req);
> +
> + p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_ERROR);
> +}
> +
> +static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
> +{
> + int value;
> +
> + value = usb_ep_disable(ep);
> + if (value < 0)
> + dev_info(&cdev->gadget->dev,
> + "disable %s --> %d\n", ep->name, value);
> +}
> +
> +static void disable_usb9pfs(struct f_usb9pfs *usb9pfs)
> +{
> + struct usb_composite_dev *cdev =
> + usb9pfs->function.config->cdev;
> +
> + disable_ep(cdev, usb9pfs->in_ep);
> + disable_ep(cdev, usb9pfs->out_ep);
> + dev_dbg(&cdev->gadget->dev, "%s disabled\n",
> + usb9pfs->function.name);
> +}
> +
> +static int alloc_requests(struct usb_composite_dev *cdev,
> + struct f_usb9pfs *usb9pfs)
> +{
> + int ret = 0;
> +
> + usb9pfs->in_req = usb_ep_alloc_request(usb9pfs->in_ep, GFP_ATOMIC);
> + if (!usb9pfs->in_req) {
> + ret = -ENOENT;
> + goto fail;
> + }
> +
> + usb9pfs->out_req = alloc_ep_req(usb9pfs->out_ep, usb9pfs->buflen);
> + if (!usb9pfs->out_req) {
> + ret = -ENOENT;
> + goto fail_in;
> + }
> +
> + usb9pfs->in_req->complete = usb9pfs_tx_complete;
> + usb9pfs->out_req->complete = usb9pfs_rx_complete;
> +
> + /* length will be set in complete routine */
> + usb9pfs->in_req->context = usb9pfs;
> + usb9pfs->out_req->context = usb9pfs;
> +
> + return ret;
> +
> +fail_in:
> + usb_ep_free_request(usb9pfs->in_ep, usb9pfs->in_req);
> +fail:
> + return ret;
> +}
> +
> +static int enable_endpoint(struct usb_composite_dev *cdev,
> + struct f_usb9pfs *usb9pfs, struct usb_ep *ep)
> +{
> + int ret;
> +
> + ret = config_ep_by_speed(cdev->gadget, &usb9pfs->function, ep);
> + if (ret)
> + return ret;
> +
> + ret = usb_ep_enable(ep);
> + if (ret < 0)
> + return ret;
> +
> + ep->driver_data = usb9pfs;
> +
> + return ret;
> +}
> +
> +static int
> +enable_usb9pfs(struct usb_composite_dev *cdev, struct f_usb9pfs *usb9pfs)
> +{
> + int result = 0;
> +
> + result = enable_endpoint(cdev, usb9pfs, usb9pfs->in_ep);
> + if (result)
> + goto out;
> +
> + result = enable_endpoint(cdev, usb9pfs, usb9pfs->out_ep);
> + if (result)
> + goto disable_in;
> +
> + result = alloc_requests(cdev, usb9pfs);
> + if (result)
> + goto disable_out;
> +
> + dev_dbg(&cdev->gadget->dev, "%s enabled\n", usb9pfs->function.name);
> + return 0;
> +
> +disable_out:
> + usb_ep_disable(usb9pfs->out_ep);
> +disable_in:
> + usb_ep_disable(usb9pfs->in_ep);
> +out:
> + return result;
> +}
> +
> +static int p9_usbg_create(struct p9_client *client, const char *devname, char *args)
> +{
> + struct usb_composite_dev *cdev;
> + struct f_usb9pfs_dev *dev;
> + struct f_usb9pfs_dev *tmp;
> + struct f_usb9pfs *usb9pfs;
> + struct usb_function *f;
> + int ret = -ENOENT;
> + int found = 0;
> +
> + if (!devname)
> + return -EINVAL;
> +
> + mutex_lock(&usb9pfs_lock);
> + list_for_each_entry_safe(dev, tmp, &usbg_instance_list, usb9pfs_instance) {
> + if (!strncmp(devname, dev->tag, strlen(devname))) {
> + if (!dev->inuse) {
> + dev->inuse = true;
> + found = 1;
> + break;
> + }
> + ret = -EBUSY;
> + break;
> + }
> + }
> + mutex_unlock(&usb9pfs_lock);
> +
> + if (!found) {
> + pr_err("no channels available for device %s\n", devname);
> + return ret;
> + }
> +
> + usb9pfs = dev->usb9pfs;
> + if (!usb9pfs)
> + return -EINVAL;
> +
> + INIT_LIST_HEAD(&usb9pfs->tx_req_list);
> +
> + spin_lock_init(&usb9pfs->lock);
> + spin_lock_init(&usb9pfs->req_lock);
> +
> + f = &usb9pfs->function;
> + cdev = f->config->cdev;
> +
> + client->trans = (void *)usb9pfs;
> + client->status = Connected;
> + usb9pfs->client = client;
> +
> + client->trans_mod->maxsize = usb9pfs->buflen;
> +
> + return enable_usb9pfs(cdev, usb9pfs);
> +}
> +
> +static void p9_usbg_close(struct p9_client *client)
> +{
> + struct f_usb9pfs *usb9pfs;
> + struct f_usb9pfs_dev *dev;
> + struct p9_req_t *req;
> + struct f_usb9pfs_opts *opts;
> +
> + if (!client)
> + return;
> +
> + usb9pfs = client->trans;
> + if (!usb9pfs)
> + return;
> +
> + client->status = Disconnected;
> +
> + spin_lock(&usb9pfs->req_lock);
> +
> + req = usb9pfs->p9_tx_req;
> + if (req) {
> + if (!req->t_err)
> + req->t_err = -ECONNRESET;
> + p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR);
> + }
> +
> + spin_unlock(&usb9pfs->req_lock);
> +
> + disable_usb9pfs(usb9pfs);
> +
> + opts = container_of(usb9pfs->function.fi,
> + struct f_usb9pfs_opts, func_inst);
> +
> + dev = opts->dev;
> +
> + mutex_lock(&usb9pfs_lock);
> + dev->inuse = false;
> + mutex_unlock(&usb9pfs_lock);
> +}
> +
> +static int p9_usbg_request(struct p9_client *client, struct p9_req_t *p9_req)
> +{
> + struct f_usb9pfs *usb9pfs = client->trans;
> + unsigned long flags;
> +
> + if (client->status != Connected)
> + return -EBUSY;
> +
> + spin_lock_irqsave(&usb9pfs->lock, flags);
> + list_add_tail(&p9_req->req_list, &usb9pfs->tx_req_list);
> + spin_unlock_irqrestore(&usb9pfs->lock, flags);
> +
> + spin_lock_irqsave(&usb9pfs->req_lock, flags);
> + usb9pfs_transmit(usb9pfs);
> + spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
> +
> + return 0;
> +}
> +
> +static int p9_usbg_cancel(struct p9_client *client, struct p9_req_t *req)
> +{
> + struct f_usb9pfs *usb9pfs = client->trans;
> + int ret = 1;
> +
> + p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
> +
> + spin_lock(&usb9pfs->req_lock);
> +
> + if (req->status == REQ_STATUS_UNSENT) {
> + list_del(&req->req_list);
> + WRITE_ONCE(req->status, REQ_STATUS_FLSHD);
> + p9_req_put(client, req);
> + ret = 0;
> + }
> + spin_unlock(&usb9pfs->req_lock);
> +
> + return ret;
> +}
> +
> +static struct p9_trans_module p9_usbg_trans = {
> + .name = "usbg",
> + .create = p9_usbg_create,
> + .close = p9_usbg_close,
> + .request = p9_usbg_request,
> + .cancel = p9_usbg_cancel,
> + .owner = THIS_MODULE,
> +};
> +
> +/*-------------------------------------------------------------------------*/
> +
> +#define USB_PROTOCOL_9PFS 0x09
> +
> +static struct usb_interface_descriptor usb9pfs_intf = {
> + .bLength = sizeof(usb9pfs_intf),
> + .bDescriptorType = USB_DT_INTERFACE,
> +
> + .bNumEndpoints = 2,
> + .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
> + .bInterfaceSubClass = USB_SUBCLASS_VENDOR_SPEC,
> + .bInterfaceProtocol = USB_PROTOCOL_9PFS,
> +
> + /* .iInterface = DYNAMIC */
> +};
> +
> +/* full speed support: */
> +
> +static struct usb_endpoint_descriptor fs_usb9pfs_source_desc = {
> + .bLength = USB_DT_ENDPOINT_SIZE,
> + .bDescriptorType = USB_DT_ENDPOINT,
> +
> + .bEndpointAddress = USB_DIR_IN,
> + .bmAttributes = USB_ENDPOINT_XFER_BULK,
> +};
> +
> +static struct usb_endpoint_descriptor fs_usb9pfs_sink_desc = {
> + .bLength = USB_DT_ENDPOINT_SIZE,
> + .bDescriptorType = USB_DT_ENDPOINT,
> +
> + .bEndpointAddress = USB_DIR_OUT,
> + .bmAttributes = USB_ENDPOINT_XFER_BULK,
> +};
> +
> +static struct usb_descriptor_header *fs_usb9pfs_descs[] = {
> + (struct usb_descriptor_header *)&usb9pfs_intf,
> + (struct usb_descriptor_header *)&fs_usb9pfs_sink_desc,
> + (struct usb_descriptor_header *)&fs_usb9pfs_source_desc,
> + NULL,
> +};
> +
> +/* high speed support: */
> +
> +static struct usb_endpoint_descriptor hs_usb9pfs_source_desc = {
> + .bLength = USB_DT_ENDPOINT_SIZE,
> + .bDescriptorType = USB_DT_ENDPOINT,
> +
> + .bmAttributes = USB_ENDPOINT_XFER_BULK,
> + .wMaxPacketSize = cpu_to_le16(512),
> +};
> +
> +static struct usb_endpoint_descriptor hs_usb9pfs_sink_desc = {
> + .bLength = USB_DT_ENDPOINT_SIZE,
> + .bDescriptorType = USB_DT_ENDPOINT,
> +
> + .bmAttributes = USB_ENDPOINT_XFER_BULK,
> + .wMaxPacketSize = cpu_to_le16(512),
> +};
> +
> +static struct usb_descriptor_header *hs_usb9pfs_descs[] = {
> + (struct usb_descriptor_header *)&usb9pfs_intf,
> + (struct usb_descriptor_header *)&hs_usb9pfs_source_desc,
> + (struct usb_descriptor_header *)&hs_usb9pfs_sink_desc,
> + NULL,
> +};
> +
> +/* super speed support: */
> +
> +static struct usb_endpoint_descriptor ss_usb9pfs_source_desc = {
> + .bLength = USB_DT_ENDPOINT_SIZE,
> + .bDescriptorType = USB_DT_ENDPOINT,
> +
> + .bmAttributes = USB_ENDPOINT_XFER_BULK,
> + .wMaxPacketSize = cpu_to_le16(1024),
> +};
> +
> +static struct usb_ss_ep_comp_descriptor ss_usb9pfs_source_comp_desc = {
> + .bLength = USB_DT_SS_EP_COMP_SIZE,
> + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
> + .bMaxBurst = 0,
> + .bmAttributes = 0,
> + .wBytesPerInterval = 0,
> +};
> +
> +static struct usb_endpoint_descriptor ss_usb9pfs_sink_desc = {
> + .bLength = USB_DT_ENDPOINT_SIZE,
> + .bDescriptorType = USB_DT_ENDPOINT,
> +
> + .bmAttributes = USB_ENDPOINT_XFER_BULK,
> + .wMaxPacketSize = cpu_to_le16(1024),
> +};
> +
> +static struct usb_ss_ep_comp_descriptor ss_usb9pfs_sink_comp_desc = {
> + .bLength = USB_DT_SS_EP_COMP_SIZE,
> + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
> + .bMaxBurst = 0,
> + .bmAttributes = 0,
> + .wBytesPerInterval = 0,
> +};
> +
> +static struct usb_descriptor_header *ss_usb9pfs_descs[] = {
> + (struct usb_descriptor_header *)&usb9pfs_intf,
> + (struct usb_descriptor_header *)&ss_usb9pfs_source_desc,
> + (struct usb_descriptor_header *)&ss_usb9pfs_source_comp_desc,
> + (struct usb_descriptor_header *)&ss_usb9pfs_sink_desc,
> + (struct usb_descriptor_header *)&ss_usb9pfs_sink_comp_desc,
> + NULL,
> +};
> +
> +/* function-specific strings: */
> +static struct usb_string strings_usb9pfs[] = {
> + [0].s = "usb9pfs input to output",
> + { } /* end of list */
> +};
> +
> +static struct usb_gadget_strings stringtab_usb9pfs = {
> + .language = 0x0409, /* en-us */
> + .strings = strings_usb9pfs,
> +};
> +
> +static struct usb_gadget_strings *usb9pfs_strings[] = {
> + &stringtab_usb9pfs,
> + NULL,
> +};
> +
> +/*-------------------------------------------------------------------------*/
> +
> +static int usb9pfs_func_bind(struct usb_configuration *c,
> + struct usb_function *f)
> +{
> + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
> + struct f_usb9pfs_opts *opts;
> + struct usb_composite_dev *cdev = c->cdev;
> + int ret;
> + int id;
> +
> + /* allocate interface ID(s) */
> + id = usb_interface_id(c, f);
> + if (id < 0)
> + return id;
> + usb9pfs_intf.bInterfaceNumber = id;
> +
> + id = usb_string_id(cdev);
> + if (id < 0)
> + return id;
> + strings_usb9pfs[0].id = id;
> + usb9pfs_intf.iInterface = id;
> +
> + /* allocate endpoints */
> + usb9pfs->in_ep = usb_ep_autoconfig(cdev->gadget,
> + &fs_usb9pfs_source_desc);
> + if (!usb9pfs->in_ep)
> + goto autoconf_fail;
> +
> + usb9pfs->out_ep = usb_ep_autoconfig(cdev->gadget,
> + &fs_usb9pfs_sink_desc);
> + if (!usb9pfs->out_ep)
> + goto autoconf_fail;
> +
> + /* support high speed hardware */
> + hs_usb9pfs_source_desc.bEndpointAddress =
> + fs_usb9pfs_source_desc.bEndpointAddress;
> + hs_usb9pfs_sink_desc.bEndpointAddress =
> + fs_usb9pfs_sink_desc.bEndpointAddress;
> +
> + /* support super speed hardware */
> + ss_usb9pfs_source_desc.bEndpointAddress =
> + fs_usb9pfs_source_desc.bEndpointAddress;
> + ss_usb9pfs_sink_desc.bEndpointAddress =
> + fs_usb9pfs_sink_desc.bEndpointAddress;
> +
> + ret = usb_assign_descriptors(f, fs_usb9pfs_descs, hs_usb9pfs_descs,
> + ss_usb9pfs_descs, ss_usb9pfs_descs);
> + if (ret)
> + return ret;
> +
> + opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst);
> + opts->dev->usb9pfs = usb9pfs;
> +
> + dev_dbg(&cdev->gadget->dev, "%s speed %s: IN/%s, OUT/%s\n",
> + (gadget_is_superspeed(c->cdev->gadget) ? "super" :
> + (gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")),
> + f->name, usb9pfs->in_ep->name, usb9pfs->out_ep->name);
> +
> + return 0;
> +
> +autoconf_fail:
> + ERROR(cdev, "%s: can't autoconfigure on %s\n",
> + f->name, cdev->gadget->name);
> + return -ENODEV;
> +}
> +
> +static void usb9pfs_free_func(struct usb_function *f)
> +{
> + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
> + struct f_usb9pfs_opts *opts;
> +
> + kfree(usb9pfs);
> +
> + opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst);
> +
> + mutex_lock(&opts->lock);
> + opts->refcnt--;
> + mutex_unlock(&opts->lock);
> +
> + usb_free_all_descriptors(f);
> +}
> +
> +static int usb9pfs_set_alt(struct usb_function *f,
> + unsigned int intf, unsigned int alt)
> +{
> + return 0;
> +}
> +
> +static void usb9pfs_disable(struct usb_function *f)
> +{
> + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
> + struct p9_req_t *req;
> +
> + spin_lock(&usb9pfs->req_lock);
> +
> + req = usb9pfs->p9_tx_req;
> +
> + if (!req->t_err)
> + req->t_err = -ECONNRESET;
> + p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR);
> +
> + spin_unlock(&usb9pfs->req_lock);
> +}
> +
> +static struct usb_function *usb9pfs_alloc(struct usb_function_instance *fi)
> +{
> + struct f_usb9pfs_opts *usb9pfs_opts;
> + struct f_usb9pfs *usb9pfs;
> +
> + usb9pfs = kzalloc(sizeof(*usb9pfs), GFP_KERNEL);
> + if (!usb9pfs)
> + return ERR_PTR(-ENOMEM);
> +
> + usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
> +
> + mutex_lock(&usb9pfs_opts->lock);
> + usb9pfs_opts->refcnt++;
> + mutex_unlock(&usb9pfs_opts->lock);
> +
> + usb9pfs->buflen = usb9pfs_opts->buflen;
> +
> + usb9pfs->function.name = "usb9pfs";
> + usb9pfs->function.bind = usb9pfs_func_bind;
> + usb9pfs->function.set_alt = usb9pfs_set_alt;
> + usb9pfs->function.disable = usb9pfs_disable;
> + usb9pfs->function.strings = usb9pfs_strings;
> +
> + usb9pfs->function.free_func = usb9pfs_free_func;
> +
> + return &usb9pfs->function;
> +}
> +
> +static inline struct f_usb9pfs_opts *to_f_usb9pfs_opts(struct config_item *item)
> +{
> + return container_of(to_config_group(item), struct f_usb9pfs_opts,
> + func_inst.group);
> +}
> +
> +static inline struct f_usb9pfs_opts *fi_to_f_usb9pfs_opts(struct usb_function_instance *fi)
> +{
> + return container_of(fi, struct f_usb9pfs_opts, func_inst);
> +}
> +
> +static void usb9pfs_attr_release(struct config_item *item)
> +{
> + struct f_usb9pfs_opts *usb9pfs_opts = to_f_usb9pfs_opts(item);
> +
> + usb_put_function_instance(&usb9pfs_opts->func_inst);
> +}
> +
> +static struct configfs_item_operations usb9pfs_item_ops = {
> + .release = usb9pfs_attr_release,
> +};
> +
> +static ssize_t f_usb9pfs_opts_buflen_show(struct config_item *item, char *page)
> +{
> + struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
> + int result;
> +
> + mutex_lock(&opts->lock);
> + result = sprintf(page, "%d\n", opts->buflen);
> + mutex_unlock(&opts->lock);
> +
> + return result;
> +}
> +
> +static ssize_t f_usb9pfs_opts_buflen_store(struct config_item *item,
> + const char *page, size_t len)
> +{
> + struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
> + int ret;
> + u32 num;
> +
> + mutex_lock(&opts->lock);
> + if (opts->refcnt) {
> + ret = -EBUSY;
> + goto end;
> + }
> +
> + ret = kstrtou32(page, 0, &num);
> + if (ret)
> + goto end;
> +
> + opts->buflen = num;
> + ret = len;
> +end:
> + mutex_unlock(&opts->lock);
> + return ret;
> +}
> +
> +CONFIGFS_ATTR(f_usb9pfs_opts_, buflen);
> +
> +static struct configfs_attribute *usb9pfs_attrs[] = {
> + &f_usb9pfs_opts_attr_buflen,
> + NULL,
> +};
> +
> +static const struct config_item_type usb9pfs_func_type = {
> + .ct_item_ops = &usb9pfs_item_ops,
> + .ct_attrs = usb9pfs_attrs,
> + .ct_owner = THIS_MODULE,
> +};
> +
> +static struct f_usb9pfs_dev *_usb9pfs_do_find_dev(const char *tag)
> +{
> + struct f_usb9pfs_dev *usb9pfs_dev;
> + struct f_usb9pfs_dev *tmp;
> +
> + if (!tag)
> + return NULL;
> +
> + list_for_each_entry_safe(usb9pfs_dev, tmp, &usbg_instance_list, usb9pfs_instance) {
> + if (strcmp(usb9pfs_dev->tag, tag) == 0)
> + return usb9pfs_dev;
> + }
> +
> + return NULL;
> +}
> +
> +static int usb9pfs_tag_instance(struct f_usb9pfs_dev *dev, const char *tag)
> +{
> + struct f_usb9pfs_dev *existing;
> + int ret = 0;
> +
> + mutex_lock(&usb9pfs_lock);
> + existing = _usb9pfs_do_find_dev(tag);
> + if (!existing)
> + strscpy(dev->tag, tag, ARRAY_SIZE(dev->tag));
> + else if (existing != dev)
> + ret = -EBUSY;
> + mutex_unlock(&usb9pfs_lock);
> +
> + return ret;
> +}
> +
> +static int usb9pfs_set_inst_tag(struct usb_function_instance *fi, const char *tag)
> +{
> + if (strlen(tag) >= sizeof_field(struct f_usb9pfs_dev, tag))
> + return -ENAMETOOLONG;
> + return usb9pfs_tag_instance(fi_to_f_usb9pfs_opts(fi)->dev, tag);
> +}
> +
> +static void usb9pfs_free_instance(struct usb_function_instance *fi)
> +{
> + struct f_usb9pfs_opts *usb9pfs_opts;
> +
> + usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
> + kfree(usb9pfs_opts);
> +}
> +
> +static struct usb_function_instance *usb9pfs_alloc_instance(void)
> +{
> + struct f_usb9pfs_opts *usb9pfs_opts;
> + struct f_usb9pfs_dev *dev;
> +
> + usb9pfs_opts = kzalloc(sizeof(*usb9pfs_opts), GFP_KERNEL);
> + if (!usb9pfs_opts)
> + return ERR_PTR(-ENOMEM);
> +
> + mutex_init(&usb9pfs_opts->lock);
> +
> + usb9pfs_opts->func_inst.set_inst_name = usb9pfs_set_inst_tag;
> + usb9pfs_opts->func_inst.free_func_inst = usb9pfs_free_instance;
> +
> + usb9pfs_opts->buflen = DEFAULT_BUFLEN;
> +
> + mutex_lock(&usb9pfs_lock);
> + dev = kzalloc(sizeof(*dev), GFP_KERNEL);
> + if (IS_ERR(dev)) {
> + mutex_unlock(&usb9pfs_lock);
> + kfree(usb9pfs_opts);
> + return ERR_CAST(dev);
> + }
> + list_add_tail(&dev->usb9pfs_instance, &usbg_instance_list);
> + mutex_unlock(&usb9pfs_lock);
> +
> + usb9pfs_opts->dev = dev;
> + dev->opts = usb9pfs_opts;
> +
> + config_group_init_type_name(&usb9pfs_opts->func_inst.group, "",
> + &usb9pfs_func_type);
> +
> + return &usb9pfs_opts->func_inst;
> +}
> +DECLARE_USB_FUNCTION(usb9pfs, usb9pfs_alloc_instance, usb9pfs_alloc);
> +
> +static int __init usb9pfs_modinit(void)
> +{
> + int ret;
> +
> + INIT_LIST_HEAD(&usbg_instance_list);
> +
> + ret = usb_function_register(&usb9pfsusb_func);
> + if (!ret)
> + v9fs_register_trans(&p9_usbg_trans);
> +
> + return ret;
> +}
> +
> +static void __exit usb9pfs_modexit(void)
> +{
> + usb_function_unregister(&usb9pfsusb_func);
> + v9fs_unregister_trans(&p9_usbg_trans);
> +}
> +
> +module_init(usb9pfs_modinit);
> +module_exit(usb9pfs_modexit);
> +
> +MODULE_ALIAS_9P("usbg");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("USB gadget 9pfs transport");
> +MODULE_AUTHOR("Michael Grzeschik");
>


2024-05-10 10:16:51

by Michael Grzeschik

[permalink] [raw]
Subject: Re: [PATCH v4 2/3] net/9p/usbg: Add new usb gadget function transport

On Fri, May 10, 2024 at 11:25:47AM +0200, Andrzej Pietrasiewicz wrote:
>Hi Michael,
>
>W dniu 30.04.2024 o?01:33, Michael Grzeschik pisze:
>>Add the new gadget function for 9pfs transport. This function is
>>defining an simple 9pfs transport interface that consists of one in and
>>one out endpoint. The endpoints transmit and receive the 9pfs protocol
>>payload when mounting a 9p filesystem over usb.
>>
>>Signed-off-by: Michael Grzeschik <[email protected]>
>>
>>---
>>v3 -> v4:
>> - implemented conn_cancel
>
>I tried this scenario:
>
>1) run all the components and have 9pfs up and running
>2) stop the forwarder
>3) umount -f at the gadget side - this indeed succeeds now in v4
>4) start the forwarder again
>5) mount at the gadget side - this hangs.
>
>Did this scenario work for you?

I actually tested this exact scenario. So this is
suprising. I will try this again just to be sure
that I did send the latest version.

My latest testsetup included the dummy_hcd. Did you test on real hardware?


Michael

>> - moved from mount_tag to device name like ffs does
>> - renamed function_list to usb9pfs_instance
>> - renamed usbg_function_list to usb9pfs_instance_list
>> - renamed rx/tx_fill to queue_rx/tx
>> - added use of retvals
>> - added locking comment over usb9pfs_transmit
>> - using if_else instead of two pathed switch calls
>> - fixed return values of completion handler
>> - using void pointer as parameter in rx_header
>> - added a missed req_put in rx_header
>> - removed extra disable function but call disable_ep directly
>> - repaired several return values
>> - remove the suspicious disable / enable path in usbg_create
>>v2 -> v3: -
>>v1 -> v2:
>> - move the driver to net/9p/trans_usbg.c
>> - fixed the commit title
>> - fix %zu usage in p9_debug for size_t type
>> - define functions static that are only used localy
>> - return 0 in alloc_requests
>> - use id_alloc_max instead of ida_simple_get
>> - call ida_free in usb9pfs_free_func
>> - call kfree for usb9pfs->tag and usb9pfs in usb9pfs_free_func
>> - add MODULE_ALIAS_9P to load this module automatic when mounting
>> - improved the documentation
>> - added depends on USB_GADGET in Kconfig
>>---
>> Documentation/filesystems/9p.rst | 17 +-
>> net/9p/Kconfig | 6 +
>> net/9p/Makefile | 4 +
>> net/9p/trans_usbg.c | 983 +++++++++++++++++++++++++++++++++++++++
>> 4 files changed, 1009 insertions(+), 1 deletion(-)
>>
>>diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst
>>index 1e0e0bb6fdf91..10cf79dc287f8 100644
>>--- a/Documentation/filesystems/9p.rst
>>+++ b/Documentation/filesystems/9p.rst
>>@@ -48,11 +48,25 @@ For server running on QEMU host with virtio transport::
>> mount -t 9p -o trans=virtio <mount_tag> /mnt/9
>>-where mount_tag is the tag associated by the server to each of the exported
>>+where mount_tag is the tag generated by the server to each of the exported
>> mount points. Each 9P export is seen by the client as a virtio device with an
>> associated "mount_tag" property. Available mount tags can be
>> seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
>>+USBG Usage
>>+==========
>>+
>>+To mount a 9p FS on a USB Host accessible via the gadget at runtime::
>>+
>>+ mount -t 9p -o trans=usbg,aname=/path/to/fs <device> /mnt/9
>>+
>>+To mount a 9p FS on a USB Host accessible via the gadget as root filesystem::
>>+
>>+ root=<device> rootfstype=9p rootflags=trans=usbg,cache=loose,uname=root,access=0,dfltuid=0,dfltgid=0,aname=/path/to/rootfs
>>+
>>+where <device> is the tag associated by the usb gadget transport.
>>+It is defined by the configfs instance name.
>>+
>> Options
>> =======
>>@@ -68,6 +82,7 @@ Options
>> virtio connect to the next virtio channel available
>> (from QEMU with trans_virtio module)
>> rdma connect to a specified RDMA channel
>>+ usbg connect to a specified usb gadget channel
>> ======== ============================================
>> uname=name user name to attempt mount as on the remote server. The
>>diff --git a/net/9p/Kconfig b/net/9p/Kconfig
>>index 00ebce9e5a657..c3d357eb8bb37 100644
>>--- a/net/9p/Kconfig
>>+++ b/net/9p/Kconfig
>>@@ -39,6 +39,12 @@ config NET_9P_XEN
>> This builds support for a transport for 9pfs between
>> two Xen domains.
>>+config NET_9P_USBG
>>+ bool "9P USB Gadget Transport"
>>+ depends on USB_GADGET
>>+ help
>>+ This builds support for a transport for 9pfs over
>>+ usb gadget.
>> config NET_9P_RDMA
>> depends on INET && INFINIBAND && INFINIBAND_ADDR_TRANS
>>diff --git a/net/9p/Makefile b/net/9p/Makefile
>>index 1df9b344c30bd..22794a451c3f7 100644
>>--- a/net/9p/Makefile
>>+++ b/net/9p/Makefile
>>@@ -4,6 +4,7 @@ obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
>> obj-$(CONFIG_NET_9P_XEN) += 9pnet_xen.o
>> obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o
>> obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
>>+obj-$(CONFIG_NET_9P_USBG) += 9pnet_usbg.o
>> 9pnet-objs := \
>> mod.o \
>>@@ -23,3 +24,6 @@ obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
>> 9pnet_rdma-objs := \
>> trans_rdma.o \
>>+
>>+9pnet_usbg-objs := \
>>+ trans_usbg.o \
>>diff --git a/net/9p/trans_usbg.c b/net/9p/trans_usbg.c
>>new file mode 100644
>>index 0000000000000..bc440033cbe68
>>--- /dev/null
>>+++ b/net/9p/trans_usbg.c
>>@@ -0,0 +1,983 @@
>>+// SPDX-License-Identifier: GPL-2.0+
>>+/*
>>+ * trans_usbg.c - USB peripheral usb9pfs configuration driver and transport.
>>+ *
>>+ * Copyright (C) 2024 Michael Grzeschik <[email protected]>
>>+ */
>>+
>>+/* Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs
>>+ * transport to mount host exported filesystem via usb gadget.
>>+ */
>>+
>>+/* +--------------------------+ | +--------------------------+
>>+ * | 9PFS mounting client | | | 9PFS exporting server |
>>+ * SW | | | | |
>>+ * | (this:trans_usbg) | | |(e.g. diod or nfs-ganesha)|
>>+ * +-------------^------------+ | +-------------^------------+
>>+ * | | |
>>+ * ------------------|------------------------------------|-------------
>>+ * | | |
>>+ * +-------------v------------+ | +-------------v------------+
>>+ * | | | | |
>>+ * HW | USB Device Controller <---------> USB Host Controller |
>>+ * | | | | |
>>+ * +--------------------------+ | +--------------------------+
>>+ */
>>+
>>+#include <linux/slab.h>
>>+#include <linux/kernel.h>
>>+#include <linux/device.h>
>>+#include <linux/module.h>
>>+#include <linux/err.h>
>>+#include <linux/usb/composite.h>
>>+#include <linux/usb/u_f.h>
>>+
>>+#include <net/9p/9p.h>
>>+#include <net/9p/client.h>
>>+#include <net/9p/transport.h>
>>+
>>+#define DEFAULT_BUFLEN 16384
>>+
>>+struct f_usb9pfs {
>>+ struct p9_client *client;
>>+
>>+ struct p9_req_t *p9_tx_req;
>>+
>>+ struct list_head tx_req_list;
>>+
>>+ /* 9p request lock for en/dequeue */
>>+ spinlock_t lock;
>>+ /* usb request lock for en/dequeue */
>>+ spinlock_t req_lock;
>>+
>>+ struct usb_request *in_req;
>>+ struct usb_request *out_req;
>>+
>>+ struct usb_ep *in_ep;
>>+ struct usb_ep *out_ep;
>>+
>>+ unsigned int buflen;
>>+
>>+ struct usb_function function;
>>+};
>>+
>>+static inline struct f_usb9pfs *func_to_usb9pfs(struct usb_function *f)
>>+{
>>+ return container_of(f, struct f_usb9pfs, function);
>>+}
>>+
>>+struct f_usb9pfs_opts {
>>+ struct usb_function_instance func_inst;
>>+ unsigned int buflen;
>>+
>>+ struct f_usb9pfs_dev *dev;
>>+
>>+ /* Read/write access to configfs attributes is handled by configfs.
>>+ *
>>+ * This is to protect the data from concurrent access by read/write
>>+ * and create symlink/remove symlink.
>>+ */
>>+ struct mutex lock;
>>+ int refcnt;
>>+};
>>+
>>+struct f_usb9pfs_dev {
>>+ struct f_usb9pfs *usb9pfs;
>>+ struct f_usb9pfs_opts *opts;
>>+ char tag[41];
>>+ bool inuse;
>>+
>>+ struct list_head usb9pfs_instance;
>>+};
>>+
>>+static DEFINE_MUTEX(usb9pfs_lock);
>>+static struct list_head usbg_instance_list;
>>+
>>+static int usb9pfs_queue_tx(struct f_usb9pfs *usb9pfs, struct usb_request *req,
>>+ gfp_t gfp_flags)
>>+{
>>+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>+ int ret = -ENOMEM;
>>+
>>+ if (!(usb9pfs->p9_tx_req->tc.size % usb9pfs->in_ep->maxpacket))
>>+ req->zero = 1;
>>+
>>+ req->buf = usb9pfs->p9_tx_req->tc.sdata;
>>+ req->length = usb9pfs->p9_tx_req->tc.size;
>>+
>>+ dev_dbg(&cdev->gadget->dev, "%s usb9pfs send --> %d/%d, zero: %d\n",
>>+ usb9pfs->in_ep->name, req->actual, req->length, req->zero);
>>+
>>+ ret = usb_ep_queue(usb9pfs->in_ep, req, gfp_flags);
>>+
>>+ dev_dbg(&cdev->gadget->dev, "tx submit --> %d\n", ret);
>>+
>>+ return ret;
>>+}
>>+
>>+static int usb9pfs_queue_rx(struct f_usb9pfs *usb9pfs, struct usb_request *req,
>>+ gfp_t gfp_flags)
>>+{
>>+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>+ int ret = -ENOMEM;
>>+
>>+ ret = usb_ep_queue(usb9pfs->out_ep, req, gfp_flags);
>>+
>>+ dev_dbg(&cdev->gadget->dev, "rx submit --> %d\n", ret);
>>+
>>+ return ret;
>>+}
>>+
>>+/* This needs to be called with usb9pfs->req_lock held */
>>+static int usb9pfs_transmit(struct f_usb9pfs *usb9pfs)
>>+{
>>+ struct p9_req_t *p9_req = NULL;
>>+ unsigned long flags;
>>+ int ret = 0;
>>+
>>+ spin_lock_irqsave(&usb9pfs->lock, flags);
>>+
>>+ if (usb9pfs->p9_tx_req) {
>>+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>+ return -EBUSY;
>>+ }
>>+
>>+ p9_req = list_first_entry_or_null(&usb9pfs->tx_req_list,
>>+ struct p9_req_t, req_list);
>>+ if (!p9_req) {
>>+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>+ return -ENOENT;
>>+ }
>>+
>>+ list_del(&p9_req->req_list);
>>+
>>+ usb9pfs->p9_tx_req = p9_req;
>>+
>>+ p9_req_get(usb9pfs->p9_tx_req);
>>+
>>+ ret = usb9pfs_queue_tx(usb9pfs, usb9pfs->in_req, GFP_ATOMIC);
>>+
>>+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>+
>>+ return ret;
>>+}
>>+
>>+static void usb9pfs_tx_complete(struct usb_ep *ep, struct usb_request *req)
>>+{
>>+ struct f_usb9pfs *usb9pfs = ep->driver_data;
>>+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>+ int ret = 0;
>>+
>>+ if (req->status) {
>>+ dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
>>+ ep->name, req->status, req->actual, req->length);
>>+ goto free_req;
>>+ }
>>+
>>+ /* reset zero packages */
>>+ req->zero = 0;
>>+
>>+ dev_dbg(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
>>+ ep->name, req->status, req->actual, req->length);
>>+
>>+ spin_lock(&usb9pfs->req_lock);
>>+
>>+ WRITE_ONCE(usb9pfs->p9_tx_req->status, REQ_STATUS_SENT);
>>+
>>+ p9_req_put(usb9pfs->client, usb9pfs->p9_tx_req);
>>+
>>+ ret = usb9pfs_queue_rx(usb9pfs, usb9pfs->out_req, GFP_ATOMIC);
>>+ if (ret) {
>>+ spin_unlock(&usb9pfs->req_lock);
>>+ goto free_req;
>>+ }
>>+
>>+ spin_unlock(&usb9pfs->req_lock);
>>+
>>+ return;
>>+
>>+free_req:
>>+ usb_ep_free_request(ep == usb9pfs->in_ep ?
>>+ usb9pfs->out_ep : usb9pfs->in_ep,
>>+ req->context);
>>+ free_ep_req(ep, req);
>>+}
>>+
>>+static struct p9_req_t *usb9pfs_rx_header(struct f_usb9pfs *usb9pfs, void *buf)
>>+{
>>+ struct p9_req_t *p9_rx_req;
>>+ struct p9_fcall rc;
>>+ int ret;
>>+
>>+ /* start by reading header */
>>+ rc.sdata = buf;
>>+ rc.offset = 0;
>>+ rc.capacity = P9_HDRSZ;
>>+ rc.size = P9_HDRSZ;
>>+
>>+ p9_debug(P9_DEBUG_TRANS, "mux %p got %zu bytes\n", usb9pfs,
>>+ rc.capacity - rc.offset);
>>+
>>+ ret = p9_parse_header(&rc, &rc.size, NULL, NULL, 0);
>>+ if (ret) {
>>+ p9_debug(P9_DEBUG_ERROR,
>>+ "error parsing header: %d\n", ret);
>>+ return NULL;
>>+ }
>>+
>>+ p9_debug(P9_DEBUG_TRANS,
>>+ "mux %p pkt: size: %d bytes tag: %d\n",
>>+ usb9pfs, rc.size, rc.tag);
>>+
>>+ p9_rx_req = p9_tag_lookup(usb9pfs->client, rc.tag);
>>+ if (!p9_rx_req || p9_rx_req->status != REQ_STATUS_SENT) {
>>+ p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", rc.tag);
>>+ return NULL;
>>+ }
>>+
>>+ if (rc.size > p9_rx_req->rc.capacity) {
>>+ p9_debug(P9_DEBUG_ERROR,
>>+ "requested packet size too big: %d for tag %d with capacity %zd\n",
>>+ rc.size, rc.tag, p9_rx_req->rc.capacity);
>>+ p9_req_put(usb9pfs->client, p9_rx_req);
>>+ return NULL;
>>+ }
>>+
>>+ if (!p9_rx_req->rc.sdata) {
>>+ p9_debug(P9_DEBUG_ERROR,
>>+ "No recv fcall for tag %d (req %p), disconnecting!\n",
>>+ rc.tag, p9_rx_req);
>>+ p9_req_put(usb9pfs->client, p9_rx_req);
>>+ return NULL;
>>+ }
>>+
>>+ return p9_rx_req;
>>+}
>>+
>>+static void usb9pfs_rx_complete(struct usb_ep *ep, struct usb_request *req)
>>+{
>>+ struct f_usb9pfs *usb9pfs = ep->driver_data;
>>+ struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>+ struct p9_req_t *p9_rx_req;
>>+ unsigned long flags;
>>+ int ret = 0;
>>+
>>+ if (req->status) {
>>+ dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
>>+ ep->name, req->status, req->actual, req->length);
>>+ goto free_req;
>>+ }
>>+
>>+ spin_lock_irqsave(&usb9pfs->req_lock, flags);
>>+
>>+ p9_rx_req = usb9pfs_rx_header(usb9pfs, req->buf);
>>+ if (!p9_rx_req) {
>>+ spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>+ goto free_req;
>>+ }
>>+
>>+ memcpy(p9_rx_req->rc.sdata, req->buf, req->actual);
>>+
>>+ p9_rx_req->rc.size = req->actual;
>>+
>>+ p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_RCVD);
>>+ p9_req_put(usb9pfs->client, p9_rx_req);
>>+
>>+ usb9pfs->p9_tx_req = NULL;
>>+
>>+ ret = usb9pfs_transmit(usb9pfs);
>>+ if (ret) {
>>+ spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>+ return;
>>+ }
>>+
>>+ spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>+
>>+ return;
>>+
>>+free_req:
>>+ usb_ep_free_request(ep == usb9pfs->in_ep ?
>>+ usb9pfs->out_ep : usb9pfs->in_ep,
>>+ req->context);
>>+ free_ep_req(ep, req);
>>+
>>+ p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_ERROR);
>>+}
>>+
>>+static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
>>+{
>>+ int value;
>>+
>>+ value = usb_ep_disable(ep);
>>+ if (value < 0)
>>+ dev_info(&cdev->gadget->dev,
>>+ "disable %s --> %d\n", ep->name, value);
>>+}
>>+
>>+static void disable_usb9pfs(struct f_usb9pfs *usb9pfs)
>>+{
>>+ struct usb_composite_dev *cdev =
>>+ usb9pfs->function.config->cdev;
>>+
>>+ disable_ep(cdev, usb9pfs->in_ep);
>>+ disable_ep(cdev, usb9pfs->out_ep);
>>+ dev_dbg(&cdev->gadget->dev, "%s disabled\n",
>>+ usb9pfs->function.name);
>>+}
>>+
>>+static int alloc_requests(struct usb_composite_dev *cdev,
>>+ struct f_usb9pfs *usb9pfs)
>>+{
>>+ int ret = 0;
>>+
>>+ usb9pfs->in_req = usb_ep_alloc_request(usb9pfs->in_ep, GFP_ATOMIC);
>>+ if (!usb9pfs->in_req) {
>>+ ret = -ENOENT;
>>+ goto fail;
>>+ }
>>+
>>+ usb9pfs->out_req = alloc_ep_req(usb9pfs->out_ep, usb9pfs->buflen);
>>+ if (!usb9pfs->out_req) {
>>+ ret = -ENOENT;
>>+ goto fail_in;
>>+ }
>>+
>>+ usb9pfs->in_req->complete = usb9pfs_tx_complete;
>>+ usb9pfs->out_req->complete = usb9pfs_rx_complete;
>>+
>>+ /* length will be set in complete routine */
>>+ usb9pfs->in_req->context = usb9pfs;
>>+ usb9pfs->out_req->context = usb9pfs;
>>+
>>+ return ret;
>>+
>>+fail_in:
>>+ usb_ep_free_request(usb9pfs->in_ep, usb9pfs->in_req);
>>+fail:
>>+ return ret;
>>+}
>>+
>>+static int enable_endpoint(struct usb_composite_dev *cdev,
>>+ struct f_usb9pfs *usb9pfs, struct usb_ep *ep)
>>+{
>>+ int ret;
>>+
>>+ ret = config_ep_by_speed(cdev->gadget, &usb9pfs->function, ep);
>>+ if (ret)
>>+ return ret;
>>+
>>+ ret = usb_ep_enable(ep);
>>+ if (ret < 0)
>>+ return ret;
>>+
>>+ ep->driver_data = usb9pfs;
>>+
>>+ return ret;
>>+}
>>+
>>+static int
>>+enable_usb9pfs(struct usb_composite_dev *cdev, struct f_usb9pfs *usb9pfs)
>>+{
>>+ int result = 0;
>>+
>>+ result = enable_endpoint(cdev, usb9pfs, usb9pfs->in_ep);
>>+ if (result)
>>+ goto out;
>>+
>>+ result = enable_endpoint(cdev, usb9pfs, usb9pfs->out_ep);
>>+ if (result)
>>+ goto disable_in;
>>+
>>+ result = alloc_requests(cdev, usb9pfs);
>>+ if (result)
>>+ goto disable_out;
>>+
>>+ dev_dbg(&cdev->gadget->dev, "%s enabled\n", usb9pfs->function.name);
>>+ return 0;
>>+
>>+disable_out:
>>+ usb_ep_disable(usb9pfs->out_ep);
>>+disable_in:
>>+ usb_ep_disable(usb9pfs->in_ep);
>>+out:
>>+ return result;
>>+}
>>+
>>+static int p9_usbg_create(struct p9_client *client, const char *devname, char *args)
>>+{
>>+ struct usb_composite_dev *cdev;
>>+ struct f_usb9pfs_dev *dev;
>>+ struct f_usb9pfs_dev *tmp;
>>+ struct f_usb9pfs *usb9pfs;
>>+ struct usb_function *f;
>>+ int ret = -ENOENT;
>>+ int found = 0;
>>+
>>+ if (!devname)
>>+ return -EINVAL;
>>+
>>+ mutex_lock(&usb9pfs_lock);
>>+ list_for_each_entry_safe(dev, tmp, &usbg_instance_list, usb9pfs_instance) {
>>+ if (!strncmp(devname, dev->tag, strlen(devname))) {
>>+ if (!dev->inuse) {
>>+ dev->inuse = true;
>>+ found = 1;
>>+ break;
>>+ }
>>+ ret = -EBUSY;
>>+ break;
>>+ }
>>+ }
>>+ mutex_unlock(&usb9pfs_lock);
>>+
>>+ if (!found) {
>>+ pr_err("no channels available for device %s\n", devname);
>>+ return ret;
>>+ }
>>+
>>+ usb9pfs = dev->usb9pfs;
>>+ if (!usb9pfs)
>>+ return -EINVAL;
>>+
>>+ INIT_LIST_HEAD(&usb9pfs->tx_req_list);
>>+
>>+ spin_lock_init(&usb9pfs->lock);
>>+ spin_lock_init(&usb9pfs->req_lock);
>>+
>>+ f = &usb9pfs->function;
>>+ cdev = f->config->cdev;
>>+
>>+ client->trans = (void *)usb9pfs;
>>+ client->status = Connected;
>>+ usb9pfs->client = client;
>>+
>>+ client->trans_mod->maxsize = usb9pfs->buflen;
>>+
>>+ return enable_usb9pfs(cdev, usb9pfs);
>>+}
>>+
>>+static void p9_usbg_close(struct p9_client *client)
>>+{
>>+ struct f_usb9pfs *usb9pfs;
>>+ struct f_usb9pfs_dev *dev;
>>+ struct p9_req_t *req;
>>+ struct f_usb9pfs_opts *opts;
>>+
>>+ if (!client)
>>+ return;
>>+
>>+ usb9pfs = client->trans;
>>+ if (!usb9pfs)
>>+ return;
>>+
>>+ client->status = Disconnected;
>>+
>>+ spin_lock(&usb9pfs->req_lock);
>>+
>>+ req = usb9pfs->p9_tx_req;
>>+ if (req) {
>>+ if (!req->t_err)
>>+ req->t_err = -ECONNRESET;
>>+ p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR);
>>+ }
>>+
>>+ spin_unlock(&usb9pfs->req_lock);
>>+
>>+ disable_usb9pfs(usb9pfs);
>>+
>>+ opts = container_of(usb9pfs->function.fi,
>>+ struct f_usb9pfs_opts, func_inst);
>>+
>>+ dev = opts->dev;
>>+
>>+ mutex_lock(&usb9pfs_lock);
>>+ dev->inuse = false;
>>+ mutex_unlock(&usb9pfs_lock);
>>+}
>>+
>>+static int p9_usbg_request(struct p9_client *client, struct p9_req_t *p9_req)
>>+{
>>+ struct f_usb9pfs *usb9pfs = client->trans;
>>+ unsigned long flags;
>>+
>>+ if (client->status != Connected)
>>+ return -EBUSY;
>>+
>>+ spin_lock_irqsave(&usb9pfs->lock, flags);
>>+ list_add_tail(&p9_req->req_list, &usb9pfs->tx_req_list);
>>+ spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>+
>>+ spin_lock_irqsave(&usb9pfs->req_lock, flags);
>>+ usb9pfs_transmit(usb9pfs);
>>+ spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>+
>>+ return 0;
>>+}
>>+
>>+static int p9_usbg_cancel(struct p9_client *client, struct p9_req_t *req)
>>+{
>>+ struct f_usb9pfs *usb9pfs = client->trans;
>>+ int ret = 1;
>>+
>>+ p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
>>+
>>+ spin_lock(&usb9pfs->req_lock);
>>+
>>+ if (req->status == REQ_STATUS_UNSENT) {
>>+ list_del(&req->req_list);
>>+ WRITE_ONCE(req->status, REQ_STATUS_FLSHD);
>>+ p9_req_put(client, req);
>>+ ret = 0;
>>+ }
>>+ spin_unlock(&usb9pfs->req_lock);
>>+
>>+ return ret;
>>+}
>>+
>>+static struct p9_trans_module p9_usbg_trans = {
>>+ .name = "usbg",
>>+ .create = p9_usbg_create,
>>+ .close = p9_usbg_close,
>>+ .request = p9_usbg_request,
>>+ .cancel = p9_usbg_cancel,
>>+ .owner = THIS_MODULE,
>>+};
>>+
>>+/*-------------------------------------------------------------------------*/
>>+
>>+#define USB_PROTOCOL_9PFS 0x09
>>+
>>+static struct usb_interface_descriptor usb9pfs_intf = {
>>+ .bLength = sizeof(usb9pfs_intf),
>>+ .bDescriptorType = USB_DT_INTERFACE,
>>+
>>+ .bNumEndpoints = 2,
>>+ .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
>>+ .bInterfaceSubClass = USB_SUBCLASS_VENDOR_SPEC,
>>+ .bInterfaceProtocol = USB_PROTOCOL_9PFS,
>>+
>>+ /* .iInterface = DYNAMIC */
>>+};
>>+
>>+/* full speed support: */
>>+
>>+static struct usb_endpoint_descriptor fs_usb9pfs_source_desc = {
>>+ .bLength = USB_DT_ENDPOINT_SIZE,
>>+ .bDescriptorType = USB_DT_ENDPOINT,
>>+
>>+ .bEndpointAddress = USB_DIR_IN,
>>+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
>>+};
>>+
>>+static struct usb_endpoint_descriptor fs_usb9pfs_sink_desc = {
>>+ .bLength = USB_DT_ENDPOINT_SIZE,
>>+ .bDescriptorType = USB_DT_ENDPOINT,
>>+
>>+ .bEndpointAddress = USB_DIR_OUT,
>>+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
>>+};
>>+
>>+static struct usb_descriptor_header *fs_usb9pfs_descs[] = {
>>+ (struct usb_descriptor_header *)&usb9pfs_intf,
>>+ (struct usb_descriptor_header *)&fs_usb9pfs_sink_desc,
>>+ (struct usb_descriptor_header *)&fs_usb9pfs_source_desc,
>>+ NULL,
>>+};
>>+
>>+/* high speed support: */
>>+
>>+static struct usb_endpoint_descriptor hs_usb9pfs_source_desc = {
>>+ .bLength = USB_DT_ENDPOINT_SIZE,
>>+ .bDescriptorType = USB_DT_ENDPOINT,
>>+
>>+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
>>+ .wMaxPacketSize = cpu_to_le16(512),
>>+};
>>+
>>+static struct usb_endpoint_descriptor hs_usb9pfs_sink_desc = {
>>+ .bLength = USB_DT_ENDPOINT_SIZE,
>>+ .bDescriptorType = USB_DT_ENDPOINT,
>>+
>>+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
>>+ .wMaxPacketSize = cpu_to_le16(512),
>>+};
>>+
>>+static struct usb_descriptor_header *hs_usb9pfs_descs[] = {
>>+ (struct usb_descriptor_header *)&usb9pfs_intf,
>>+ (struct usb_descriptor_header *)&hs_usb9pfs_source_desc,
>>+ (struct usb_descriptor_header *)&hs_usb9pfs_sink_desc,
>>+ NULL,
>>+};
>>+
>>+/* super speed support: */
>>+
>>+static struct usb_endpoint_descriptor ss_usb9pfs_source_desc = {
>>+ .bLength = USB_DT_ENDPOINT_SIZE,
>>+ .bDescriptorType = USB_DT_ENDPOINT,
>>+
>>+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
>>+ .wMaxPacketSize = cpu_to_le16(1024),
>>+};
>>+
>>+static struct usb_ss_ep_comp_descriptor ss_usb9pfs_source_comp_desc = {
>>+ .bLength = USB_DT_SS_EP_COMP_SIZE,
>>+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
>>+ .bMaxBurst = 0,
>>+ .bmAttributes = 0,
>>+ .wBytesPerInterval = 0,
>>+};
>>+
>>+static struct usb_endpoint_descriptor ss_usb9pfs_sink_desc = {
>>+ .bLength = USB_DT_ENDPOINT_SIZE,
>>+ .bDescriptorType = USB_DT_ENDPOINT,
>>+
>>+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
>>+ .wMaxPacketSize = cpu_to_le16(1024),
>>+};
>>+
>>+static struct usb_ss_ep_comp_descriptor ss_usb9pfs_sink_comp_desc = {
>>+ .bLength = USB_DT_SS_EP_COMP_SIZE,
>>+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
>>+ .bMaxBurst = 0,
>>+ .bmAttributes = 0,
>>+ .wBytesPerInterval = 0,
>>+};
>>+
>>+static struct usb_descriptor_header *ss_usb9pfs_descs[] = {
>>+ (struct usb_descriptor_header *)&usb9pfs_intf,
>>+ (struct usb_descriptor_header *)&ss_usb9pfs_source_desc,
>>+ (struct usb_descriptor_header *)&ss_usb9pfs_source_comp_desc,
>>+ (struct usb_descriptor_header *)&ss_usb9pfs_sink_desc,
>>+ (struct usb_descriptor_header *)&ss_usb9pfs_sink_comp_desc,
>>+ NULL,
>>+};
>>+
>>+/* function-specific strings: */
>>+static struct usb_string strings_usb9pfs[] = {
>>+ [0].s = "usb9pfs input to output",
>>+ { } /* end of list */
>>+};
>>+
>>+static struct usb_gadget_strings stringtab_usb9pfs = {
>>+ .language = 0x0409, /* en-us */
>>+ .strings = strings_usb9pfs,
>>+};
>>+
>>+static struct usb_gadget_strings *usb9pfs_strings[] = {
>>+ &stringtab_usb9pfs,
>>+ NULL,
>>+};
>>+
>>+/*-------------------------------------------------------------------------*/
>>+
>>+static int usb9pfs_func_bind(struct usb_configuration *c,
>>+ struct usb_function *f)
>>+{
>>+ struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
>>+ struct f_usb9pfs_opts *opts;
>>+ struct usb_composite_dev *cdev = c->cdev;
>>+ int ret;
>>+ int id;
>>+
>>+ /* allocate interface ID(s) */
>>+ id = usb_interface_id(c, f);
>>+ if (id < 0)
>>+ return id;
>>+ usb9pfs_intf.bInterfaceNumber = id;
>>+
>>+ id = usb_string_id(cdev);
>>+ if (id < 0)
>>+ return id;
>>+ strings_usb9pfs[0].id = id;
>>+ usb9pfs_intf.iInterface = id;
>>+
>>+ /* allocate endpoints */
>>+ usb9pfs->in_ep = usb_ep_autoconfig(cdev->gadget,
>>+ &fs_usb9pfs_source_desc);
>>+ if (!usb9pfs->in_ep)
>>+ goto autoconf_fail;
>>+
>>+ usb9pfs->out_ep = usb_ep_autoconfig(cdev->gadget,
>>+ &fs_usb9pfs_sink_desc);
>>+ if (!usb9pfs->out_ep)
>>+ goto autoconf_fail;
>>+
>>+ /* support high speed hardware */
>>+ hs_usb9pfs_source_desc.bEndpointAddress =
>>+ fs_usb9pfs_source_desc.bEndpointAddress;
>>+ hs_usb9pfs_sink_desc.bEndpointAddress =
>>+ fs_usb9pfs_sink_desc.bEndpointAddress;
>>+
>>+ /* support super speed hardware */
>>+ ss_usb9pfs_source_desc.bEndpointAddress =
>>+ fs_usb9pfs_source_desc.bEndpointAddress;
>>+ ss_usb9pfs_sink_desc.bEndpointAddress =
>>+ fs_usb9pfs_sink_desc.bEndpointAddress;
>>+
>>+ ret = usb_assign_descriptors(f, fs_usb9pfs_descs, hs_usb9pfs_descs,
>>+ ss_usb9pfs_descs, ss_usb9pfs_descs);
>>+ if (ret)
>>+ return ret;
>>+
>>+ opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst);
>>+ opts->dev->usb9pfs = usb9pfs;
>>+
>>+ dev_dbg(&cdev->gadget->dev, "%s speed %s: IN/%s, OUT/%s\n",
>>+ (gadget_is_superspeed(c->cdev->gadget) ? "super" :
>>+ (gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")),
>>+ f->name, usb9pfs->in_ep->name, usb9pfs->out_ep->name);
>>+
>>+ return 0;
>>+
>>+autoconf_fail:
>>+ ERROR(cdev, "%s: can't autoconfigure on %s\n",
>>+ f->name, cdev->gadget->name);
>>+ return -ENODEV;
>>+}
>>+
>>+static void usb9pfs_free_func(struct usb_function *f)
>>+{
>>+ struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
>>+ struct f_usb9pfs_opts *opts;
>>+
>>+ kfree(usb9pfs);
>>+
>>+ opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst);
>>+
>>+ mutex_lock(&opts->lock);
>>+ opts->refcnt--;
>>+ mutex_unlock(&opts->lock);
>>+
>>+ usb_free_all_descriptors(f);
>>+}
>>+
>>+static int usb9pfs_set_alt(struct usb_function *f,
>>+ unsigned int intf, unsigned int alt)
>>+{
>>+ return 0;
>>+}
>>+
>>+static void usb9pfs_disable(struct usb_function *f)
>>+{
>>+ struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
>>+ struct p9_req_t *req;
>>+
>>+ spin_lock(&usb9pfs->req_lock);
>>+
>>+ req = usb9pfs->p9_tx_req;
>>+
>>+ if (!req->t_err)
>>+ req->t_err = -ECONNRESET;
>>+ p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR);
>>+
>>+ spin_unlock(&usb9pfs->req_lock);
>>+}
>>+
>>+static struct usb_function *usb9pfs_alloc(struct usb_function_instance *fi)
>>+{
>>+ struct f_usb9pfs_opts *usb9pfs_opts;
>>+ struct f_usb9pfs *usb9pfs;
>>+
>>+ usb9pfs = kzalloc(sizeof(*usb9pfs), GFP_KERNEL);
>>+ if (!usb9pfs)
>>+ return ERR_PTR(-ENOMEM);
>>+
>>+ usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
>>+
>>+ mutex_lock(&usb9pfs_opts->lock);
>>+ usb9pfs_opts->refcnt++;
>>+ mutex_unlock(&usb9pfs_opts->lock);
>>+
>>+ usb9pfs->buflen = usb9pfs_opts->buflen;
>>+
>>+ usb9pfs->function.name = "usb9pfs";
>>+ usb9pfs->function.bind = usb9pfs_func_bind;
>>+ usb9pfs->function.set_alt = usb9pfs_set_alt;
>>+ usb9pfs->function.disable = usb9pfs_disable;
>>+ usb9pfs->function.strings = usb9pfs_strings;
>>+
>>+ usb9pfs->function.free_func = usb9pfs_free_func;
>>+
>>+ return &usb9pfs->function;
>>+}
>>+
>>+static inline struct f_usb9pfs_opts *to_f_usb9pfs_opts(struct config_item *item)
>>+{
>>+ return container_of(to_config_group(item), struct f_usb9pfs_opts,
>>+ func_inst.group);
>>+}
>>+
>>+static inline struct f_usb9pfs_opts *fi_to_f_usb9pfs_opts(struct usb_function_instance *fi)
>>+{
>>+ return container_of(fi, struct f_usb9pfs_opts, func_inst);
>>+}
>>+
>>+static void usb9pfs_attr_release(struct config_item *item)
>>+{
>>+ struct f_usb9pfs_opts *usb9pfs_opts = to_f_usb9pfs_opts(item);
>>+
>>+ usb_put_function_instance(&usb9pfs_opts->func_inst);
>>+}
>>+
>>+static struct configfs_item_operations usb9pfs_item_ops = {
>>+ .release = usb9pfs_attr_release,
>>+};
>>+
>>+static ssize_t f_usb9pfs_opts_buflen_show(struct config_item *item, char *page)
>>+{
>>+ struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
>>+ int result;
>>+
>>+ mutex_lock(&opts->lock);
>>+ result = sprintf(page, "%d\n", opts->buflen);
>>+ mutex_unlock(&opts->lock);
>>+
>>+ return result;
>>+}
>>+
>>+static ssize_t f_usb9pfs_opts_buflen_store(struct config_item *item,
>>+ const char *page, size_t len)
>>+{
>>+ struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
>>+ int ret;
>>+ u32 num;
>>+
>>+ mutex_lock(&opts->lock);
>>+ if (opts->refcnt) {
>>+ ret = -EBUSY;
>>+ goto end;
>>+ }
>>+
>>+ ret = kstrtou32(page, 0, &num);
>>+ if (ret)
>>+ goto end;
>>+
>>+ opts->buflen = num;
>>+ ret = len;
>>+end:
>>+ mutex_unlock(&opts->lock);
>>+ return ret;
>>+}
>>+
>>+CONFIGFS_ATTR(f_usb9pfs_opts_, buflen);
>>+
>>+static struct configfs_attribute *usb9pfs_attrs[] = {
>>+ &f_usb9pfs_opts_attr_buflen,
>>+ NULL,
>>+};
>>+
>>+static const struct config_item_type usb9pfs_func_type = {
>>+ .ct_item_ops = &usb9pfs_item_ops,
>>+ .ct_attrs = usb9pfs_attrs,
>>+ .ct_owner = THIS_MODULE,
>>+};
>>+
>>+static struct f_usb9pfs_dev *_usb9pfs_do_find_dev(const char *tag)
>>+{
>>+ struct f_usb9pfs_dev *usb9pfs_dev;
>>+ struct f_usb9pfs_dev *tmp;
>>+
>>+ if (!tag)
>>+ return NULL;
>>+
>>+ list_for_each_entry_safe(usb9pfs_dev, tmp, &usbg_instance_list, usb9pfs_instance) {
>>+ if (strcmp(usb9pfs_dev->tag, tag) == 0)
>>+ return usb9pfs_dev;
>>+ }
>>+
>>+ return NULL;
>>+}
>>+
>>+static int usb9pfs_tag_instance(struct f_usb9pfs_dev *dev, const char *tag)
>>+{
>>+ struct f_usb9pfs_dev *existing;
>>+ int ret = 0;
>>+
>>+ mutex_lock(&usb9pfs_lock);
>>+ existing = _usb9pfs_do_find_dev(tag);
>>+ if (!existing)
>>+ strscpy(dev->tag, tag, ARRAY_SIZE(dev->tag));
>>+ else if (existing != dev)
>>+ ret = -EBUSY;
>>+ mutex_unlock(&usb9pfs_lock);
>>+
>>+ return ret;
>>+}
>>+
>>+static int usb9pfs_set_inst_tag(struct usb_function_instance *fi, const char *tag)
>>+{
>>+ if (strlen(tag) >= sizeof_field(struct f_usb9pfs_dev, tag))
>>+ return -ENAMETOOLONG;
>>+ return usb9pfs_tag_instance(fi_to_f_usb9pfs_opts(fi)->dev, tag);
>>+}
>>+
>>+static void usb9pfs_free_instance(struct usb_function_instance *fi)
>>+{
>>+ struct f_usb9pfs_opts *usb9pfs_opts;
>>+
>>+ usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
>>+ kfree(usb9pfs_opts);
>>+}
>>+
>>+static struct usb_function_instance *usb9pfs_alloc_instance(void)
>>+{
>>+ struct f_usb9pfs_opts *usb9pfs_opts;
>>+ struct f_usb9pfs_dev *dev;
>>+
>>+ usb9pfs_opts = kzalloc(sizeof(*usb9pfs_opts), GFP_KERNEL);
>>+ if (!usb9pfs_opts)
>>+ return ERR_PTR(-ENOMEM);
>>+
>>+ mutex_init(&usb9pfs_opts->lock);
>>+
>>+ usb9pfs_opts->func_inst.set_inst_name = usb9pfs_set_inst_tag;
>>+ usb9pfs_opts->func_inst.free_func_inst = usb9pfs_free_instance;
>>+
>>+ usb9pfs_opts->buflen = DEFAULT_BUFLEN;
>>+
>>+ mutex_lock(&usb9pfs_lock);
>>+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
>>+ if (IS_ERR(dev)) {
>>+ mutex_unlock(&usb9pfs_lock);
>>+ kfree(usb9pfs_opts);
>>+ return ERR_CAST(dev);
>>+ }
>>+ list_add_tail(&dev->usb9pfs_instance, &usbg_instance_list);
>>+ mutex_unlock(&usb9pfs_lock);
>>+
>>+ usb9pfs_opts->dev = dev;
>>+ dev->opts = usb9pfs_opts;
>>+
>>+ config_group_init_type_name(&usb9pfs_opts->func_inst.group, "",
>>+ &usb9pfs_func_type);
>>+
>>+ return &usb9pfs_opts->func_inst;
>>+}
>>+DECLARE_USB_FUNCTION(usb9pfs, usb9pfs_alloc_instance, usb9pfs_alloc);
>>+
>>+static int __init usb9pfs_modinit(void)
>>+{
>>+ int ret;
>>+
>>+ INIT_LIST_HEAD(&usbg_instance_list);
>>+
>>+ ret = usb_function_register(&usb9pfsusb_func);
>>+ if (!ret)
>>+ v9fs_register_trans(&p9_usbg_trans);
>>+
>>+ return ret;
>>+}
>>+
>>+static void __exit usb9pfs_modexit(void)
>>+{
>>+ usb_function_unregister(&usb9pfsusb_func);
>>+ v9fs_unregister_trans(&p9_usbg_trans);
>>+}
>>+
>>+module_init(usb9pfs_modinit);
>>+module_exit(usb9pfs_modexit);
>>+
>>+MODULE_ALIAS_9P("usbg");
>>+MODULE_LICENSE("GPL");
>>+MODULE_DESCRIPTION("USB gadget 9pfs transport");
>>+MODULE_AUTHOR("Michael Grzeschik");
>>
>
>

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2024-05-10 14:11:48

by Andrzej Pietrasiewicz

[permalink] [raw]
Subject: Re: [PATCH v4 2/3] net/9p/usbg: Add new usb gadget function transport

Hi,

W dniu 10.05.2024 o 12:11, Michael Grzeschik pisze:
> On Fri, May 10, 2024 at 11:25:47AM +0200, Andrzej Pietrasiewicz wrote:
>> Hi Michael,
>>
>> W dniu 30.04.2024 o 01:33, Michael Grzeschik pisze:
>>> Add the new gadget function for 9pfs transport. This function is
>>> defining an simple 9pfs transport interface that consists of one in and
>>> one out endpoint. The endpoints transmit and receive the 9pfs protocol
>>> payload when mounting a 9p filesystem over usb.
>>>
>>> Signed-off-by: Michael Grzeschik <[email protected]>
>>>
>>> ---
>>> v3 -> v4:
>>>   - implemented conn_cancel
>>
>> I tried this scenario:
>>
>> 1) run all the components and have 9pfs up and running
>> 2) stop the forwarder
>> 3) umount -f at the gadget side - this indeed succeeds now in v4
>> 4) start the forwarder again
>> 5) mount at the gadget side - this hangs.
>>
>> Did this scenario work for you?
>
> I actually tested this exact scenario. So this is
> suprising. I will try this again just to be sure
> that I did send the latest version.
>
> My latest testsetup included the dummy_hcd. Did you test on real hardware?

Yes, I did.

Andrzej

>
>
> Michael
>
>>>   - moved from mount_tag to device name like ffs does
>>>   - renamed function_list to usb9pfs_instance
>>>   - renamed usbg_function_list to usb9pfs_instance_list
>>>   - renamed rx/tx_fill to queue_rx/tx
>>>   - added use of retvals
>>>   - added locking comment over usb9pfs_transmit
>>>   - using if_else instead of two pathed switch calls
>>>   - fixed return values of completion handler
>>>   - using void pointer as parameter in rx_header
>>>   - added a missed req_put in rx_header
>>>   - removed extra disable function but call disable_ep directly
>>>   - repaired several return values
>>>   - remove the suspicious disable / enable path in usbg_create
>>> v2 -> v3: -
>>> v1 -> v2:
>>>   - move the driver to net/9p/trans_usbg.c
>>>   - fixed the commit title
>>>   - fix %zu usage in p9_debug for size_t type
>>>   - define functions static that are only used localy
>>>   - return 0 in alloc_requests
>>>   - use id_alloc_max instead of ida_simple_get
>>>   - call ida_free in usb9pfs_free_func
>>>   - call kfree for usb9pfs->tag and usb9pfs in usb9pfs_free_func
>>>   - add MODULE_ALIAS_9P to load this module automatic when mounting
>>>   - improved the documentation
>>>   - added depends on USB_GADGET in Kconfig
>>> ---
>>>  Documentation/filesystems/9p.rst |  17 +-
>>>  net/9p/Kconfig                   |   6 +
>>>  net/9p/Makefile                  |   4 +
>>>  net/9p/trans_usbg.c              | 983 +++++++++++++++++++++++++++++++++++++++
>>>  4 files changed, 1009 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst
>>> index 1e0e0bb6fdf91..10cf79dc287f8 100644
>>> --- a/Documentation/filesystems/9p.rst
>>> +++ b/Documentation/filesystems/9p.rst
>>> @@ -48,11 +48,25 @@ For server running on QEMU host with virtio transport::
>>>      mount -t 9p -o trans=virtio <mount_tag> /mnt/9
>>> -where mount_tag is the tag associated by the server to each of the exported
>>> +where mount_tag is the tag generated by the server to each of the exported
>>>  mount points. Each 9P export is seen by the client as a virtio device with an
>>>  associated "mount_tag" property. Available mount tags can be
>>>  seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
>>> +USBG Usage
>>> +==========
>>> +
>>> +To mount a 9p FS on a USB Host accessible via the gadget at runtime::
>>> +
>>> +    mount -t 9p -o trans=usbg,aname=/path/to/fs <device> /mnt/9
>>> +
>>> +To mount a 9p FS on a USB Host accessible via the gadget as root filesystem::
>>> +
>>> +    root=<device> rootfstype=9p
>>> rootflags=trans=usbg,cache=loose,uname=root,access=0,dfltuid=0,dfltgid=0,aname=/path/to/rootfs
>>> +
>>> +where <device> is the tag associated by the usb gadget transport.
>>> +It is defined by the configfs instance name.
>>> +
>>>  Options
>>>  =======
>>> @@ -68,6 +82,7 @@ Options
>>>              virtio      connect to the next virtio channel available
>>>                    (from QEMU with trans_virtio module)
>>>              rdma      connect to a specified RDMA channel
>>> +            usbg      connect to a specified usb gadget channel
>>>              ========  ============================================
>>>    uname=name    user name to attempt mount as on the remote server.  The
>>> diff --git a/net/9p/Kconfig b/net/9p/Kconfig
>>> index 00ebce9e5a657..c3d357eb8bb37 100644
>>> --- a/net/9p/Kconfig
>>> +++ b/net/9p/Kconfig
>>> @@ -39,6 +39,12 @@ config NET_9P_XEN
>>>        This builds support for a transport for 9pfs between
>>>        two Xen domains.
>>> +config NET_9P_USBG
>>> +    bool "9P USB Gadget Transport"
>>> +    depends on USB_GADGET
>>> +    help
>>> +      This builds support for a transport for 9pfs over
>>> +      usb gadget.
>>>  config NET_9P_RDMA
>>>      depends on INET && INFINIBAND && INFINIBAND_ADDR_TRANS
>>> diff --git a/net/9p/Makefile b/net/9p/Makefile
>>> index 1df9b344c30bd..22794a451c3f7 100644
>>> --- a/net/9p/Makefile
>>> +++ b/net/9p/Makefile
>>> @@ -4,6 +4,7 @@ obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
>>>  obj-$(CONFIG_NET_9P_XEN) += 9pnet_xen.o
>>>  obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o
>>>  obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
>>> +obj-$(CONFIG_NET_9P_USBG) += 9pnet_usbg.o
>>>  9pnet-objs := \
>>>      mod.o \
>>> @@ -23,3 +24,6 @@ obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
>>>  9pnet_rdma-objs := \
>>>      trans_rdma.o \
>>> +
>>> +9pnet_usbg-objs := \
>>> +    trans_usbg.o \
>>> diff --git a/net/9p/trans_usbg.c b/net/9p/trans_usbg.c
>>> new file mode 100644
>>> index 0000000000000..bc440033cbe68
>>> --- /dev/null
>>> +++ b/net/9p/trans_usbg.c
>>> @@ -0,0 +1,983 @@
>>> +// SPDX-License-Identifier: GPL-2.0+
>>> +/*
>>> + * trans_usbg.c - USB peripheral usb9pfs configuration driver and transport.
>>> + *
>>> + * Copyright (C) 2024 Michael Grzeschik <[email protected]>
>>> + */
>>> +
>>> +/* Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs
>>> + * transport to mount host exported filesystem via usb gadget.
>>> + */
>>> +
>>> +/*     +--------------------------+    |    +--------------------------+
>>> + *     |  9PFS mounting client    |    |    |  9PFS exporting server   |
>>> + *  SW |                          |    |    |                          |
>>> + *     |   (this:trans_usbg)      |    |    |(e.g. diod or nfs-ganesha)|
>>> + *     +-------------^------------+    |    +-------------^------------+
>>> + *                   |                 |                  |
>>> + * ------------------|------------------------------------|-------------
>>> + *                   |                 |                  |
>>> + *     +-------------v------------+    |    +-------------v------------+
>>> + *     |                          |    |    |                          |
>>> + *  HW |   USB Device Controller  <--------->   USB Host Controller    |
>>> + *     |                          |    |    |                          |
>>> + *     +--------------------------+    |    +--------------------------+
>>> + */
>>> +
>>> +#include <linux/slab.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/device.h>
>>> +#include <linux/module.h>
>>> +#include <linux/err.h>
>>> +#include <linux/usb/composite.h>
>>> +#include <linux/usb/u_f.h>
>>> +
>>> +#include <net/9p/9p.h>
>>> +#include <net/9p/client.h>
>>> +#include <net/9p/transport.h>
>>> +
>>> +#define DEFAULT_BUFLEN        16384
>>> +
>>> +struct f_usb9pfs {
>>> +    struct p9_client *client;
>>> +
>>> +    struct p9_req_t *p9_tx_req;
>>> +
>>> +    struct list_head tx_req_list;
>>> +
>>> +    /* 9p request lock for en/dequeue */
>>> +    spinlock_t lock;
>>> +    /* usb request lock for en/dequeue */
>>> +    spinlock_t req_lock;
>>> +
>>> +    struct usb_request *in_req;
>>> +    struct usb_request *out_req;
>>> +
>>> +    struct usb_ep *in_ep;
>>> +    struct usb_ep *out_ep;
>>> +
>>> +    unsigned int buflen;
>>> +
>>> +    struct usb_function function;
>>> +};
>>> +
>>> +static inline struct f_usb9pfs *func_to_usb9pfs(struct usb_function *f)
>>> +{
>>> +    return container_of(f, struct f_usb9pfs, function);
>>> +}
>>> +
>>> +struct f_usb9pfs_opts {
>>> +    struct usb_function_instance func_inst;
>>> +    unsigned int buflen;
>>> +
>>> +    struct f_usb9pfs_dev *dev;
>>> +
>>> +    /* Read/write access to configfs attributes is handled by configfs.
>>> +     *
>>> +     * This is to protect the data from concurrent access by read/write
>>> +     * and create symlink/remove symlink.
>>> +     */
>>> +    struct mutex lock;
>>> +    int refcnt;
>>> +};
>>> +
>>> +struct f_usb9pfs_dev {
>>> +    struct f_usb9pfs *usb9pfs;
>>> +    struct f_usb9pfs_opts *opts;
>>> +    char tag[41];
>>> +    bool inuse;
>>> +
>>> +    struct list_head usb9pfs_instance;
>>> +};
>>> +
>>> +static DEFINE_MUTEX(usb9pfs_lock);
>>> +static struct list_head usbg_instance_list;
>>> +
>>> +static int usb9pfs_queue_tx(struct f_usb9pfs *usb9pfs, struct usb_request *req,
>>> +                gfp_t gfp_flags)
>>> +{
>>> +    struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>> +    int ret = -ENOMEM;
>>> +
>>> +    if (!(usb9pfs->p9_tx_req->tc.size % usb9pfs->in_ep->maxpacket))
>>> +        req->zero = 1;
>>> +
>>> +    req->buf = usb9pfs->p9_tx_req->tc.sdata;
>>> +    req->length = usb9pfs->p9_tx_req->tc.size;
>>> +
>>> +    dev_dbg(&cdev->gadget->dev, "%s usb9pfs send --> %d/%d, zero: %d\n",
>>> +        usb9pfs->in_ep->name, req->actual, req->length, req->zero);
>>> +
>>> +    ret = usb_ep_queue(usb9pfs->in_ep, req, gfp_flags);
>>> +
>>> +    dev_dbg(&cdev->gadget->dev, "tx submit --> %d\n", ret);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static int usb9pfs_queue_rx(struct f_usb9pfs *usb9pfs, struct usb_request *req,
>>> +                gfp_t gfp_flags)
>>> +{
>>> +    struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>> +    int ret = -ENOMEM;
>>> +
>>> +    ret = usb_ep_queue(usb9pfs->out_ep, req, gfp_flags);
>>> +
>>> +    dev_dbg(&cdev->gadget->dev, "rx submit --> %d\n", ret);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +/* This needs to be called with usb9pfs->req_lock held */
>>> +static int usb9pfs_transmit(struct f_usb9pfs *usb9pfs)
>>> +{
>>> +    struct p9_req_t *p9_req = NULL;
>>> +    unsigned long flags;
>>> +    int ret = 0;
>>> +
>>> +    spin_lock_irqsave(&usb9pfs->lock, flags);
>>> +
>>> +    if (usb9pfs->p9_tx_req) {
>>> +        spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>> +        return -EBUSY;
>>> +    }
>>> +
>>> +    p9_req = list_first_entry_or_null(&usb9pfs->tx_req_list,
>>> +                      struct p9_req_t, req_list);
>>> +    if (!p9_req) {
>>> +        spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>> +        return -ENOENT;
>>> +    }
>>> +
>>> +    list_del(&p9_req->req_list);
>>> +
>>> +    usb9pfs->p9_tx_req = p9_req;
>>> +
>>> +    p9_req_get(usb9pfs->p9_tx_req);
>>> +
>>> +    ret = usb9pfs_queue_tx(usb9pfs, usb9pfs->in_req, GFP_ATOMIC);
>>> +
>>> +    spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static void usb9pfs_tx_complete(struct usb_ep *ep, struct usb_request *req)
>>> +{
>>> +    struct f_usb9pfs *usb9pfs = ep->driver_data;
>>> +    struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>> +    int ret = 0;
>>> +
>>> +    if (req->status) {
>>> +        dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
>>> +            ep->name, req->status, req->actual, req->length);
>>> +        goto free_req;
>>> +    }
>>> +
>>> +    /* reset zero packages */
>>> +    req->zero = 0;
>>> +
>>> +    dev_dbg(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
>>> +        ep->name, req->status, req->actual, req->length);
>>> +
>>> +    spin_lock(&usb9pfs->req_lock);
>>> +
>>> +    WRITE_ONCE(usb9pfs->p9_tx_req->status, REQ_STATUS_SENT);
>>> +
>>> +    p9_req_put(usb9pfs->client, usb9pfs->p9_tx_req);
>>> +
>>> +    ret = usb9pfs_queue_rx(usb9pfs, usb9pfs->out_req, GFP_ATOMIC);
>>> +    if (ret) {
>>> +        spin_unlock(&usb9pfs->req_lock);
>>> +        goto free_req;
>>> +    }
>>> +
>>> +    spin_unlock(&usb9pfs->req_lock);
>>> +
>>> +    return;
>>> +
>>> +free_req:
>>> +    usb_ep_free_request(ep == usb9pfs->in_ep ?
>>> +                usb9pfs->out_ep : usb9pfs->in_ep,
>>> +                req->context);
>>> +    free_ep_req(ep, req);
>>> +}
>>> +
>>> +static struct p9_req_t *usb9pfs_rx_header(struct f_usb9pfs *usb9pfs, void *buf)
>>> +{
>>> +    struct p9_req_t *p9_rx_req;
>>> +    struct p9_fcall    rc;
>>> +    int ret;
>>> +
>>> +    /* start by reading header */
>>> +    rc.sdata = buf;
>>> +    rc.offset = 0;
>>> +    rc.capacity = P9_HDRSZ;
>>> +    rc.size = P9_HDRSZ;
>>> +
>>> +    p9_debug(P9_DEBUG_TRANS, "mux %p got %zu bytes\n", usb9pfs,
>>> +         rc.capacity - rc.offset);
>>> +
>>> +    ret = p9_parse_header(&rc, &rc.size, NULL, NULL, 0);
>>> +    if (ret) {
>>> +        p9_debug(P9_DEBUG_ERROR,
>>> +             "error parsing header: %d\n", ret);
>>> +        return NULL;
>>> +    }
>>> +
>>> +    p9_debug(P9_DEBUG_TRANS,
>>> +         "mux %p pkt: size: %d bytes tag: %d\n",
>>> +         usb9pfs, rc.size, rc.tag);
>>> +
>>> +    p9_rx_req = p9_tag_lookup(usb9pfs->client, rc.tag);
>>> +    if (!p9_rx_req || p9_rx_req->status != REQ_STATUS_SENT) {
>>> +        p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", rc.tag);
>>> +        return NULL;
>>> +    }
>>> +
>>> +    if (rc.size > p9_rx_req->rc.capacity) {
>>> +        p9_debug(P9_DEBUG_ERROR,
>>> +             "requested packet size too big: %d for tag %d with capacity
>>> %zd\n",
>>> +             rc.size, rc.tag, p9_rx_req->rc.capacity);
>>> +        p9_req_put(usb9pfs->client, p9_rx_req);
>>> +        return NULL;
>>> +    }
>>> +
>>> +    if (!p9_rx_req->rc.sdata) {
>>> +        p9_debug(P9_DEBUG_ERROR,
>>> +             "No recv fcall for tag %d (req %p), disconnecting!\n",
>>> +             rc.tag, p9_rx_req);
>>> +        p9_req_put(usb9pfs->client, p9_rx_req);
>>> +        return NULL;
>>> +    }
>>> +
>>> +    return p9_rx_req;
>>> +}
>>> +
>>> +static void usb9pfs_rx_complete(struct usb_ep *ep, struct usb_request *req)
>>> +{
>>> +    struct f_usb9pfs *usb9pfs = ep->driver_data;
>>> +    struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>> +    struct p9_req_t *p9_rx_req;
>>> +    unsigned long flags;
>>> +    int ret = 0;
>>> +
>>> +    if (req->status) {
>>> +        dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
>>> +            ep->name, req->status, req->actual, req->length);
>>> +        goto free_req;
>>> +    }
>>> +
>>> +    spin_lock_irqsave(&usb9pfs->req_lock, flags);
>>> +
>>> +    p9_rx_req = usb9pfs_rx_header(usb9pfs, req->buf);
>>> +    if (!p9_rx_req) {
>>> +        spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>> +        goto free_req;
>>> +    }
>>> +
>>> +    memcpy(p9_rx_req->rc.sdata, req->buf, req->actual);
>>> +
>>> +    p9_rx_req->rc.size = req->actual;
>>> +
>>> +    p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_RCVD);
>>> +    p9_req_put(usb9pfs->client, p9_rx_req);
>>> +
>>> +    usb9pfs->p9_tx_req = NULL;
>>> +
>>> +    ret = usb9pfs_transmit(usb9pfs);
>>> +    if (ret) {
>>> +        spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>> +        return;
>>> +    }
>>> +
>>> +    spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>> +
>>> +    return;
>>> +
>>> +free_req:
>>> +    usb_ep_free_request(ep == usb9pfs->in_ep ?
>>> +                usb9pfs->out_ep : usb9pfs->in_ep,
>>> +                req->context);
>>> +    free_ep_req(ep, req);
>>> +
>>> +    p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_ERROR);
>>> +}
>>> +
>>> +static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
>>> +{
>>> +    int value;
>>> +
>>> +    value = usb_ep_disable(ep);
>>> +    if (value < 0)
>>> +        dev_info(&cdev->gadget->dev,
>>> +             "disable %s --> %d\n", ep->name, value);
>>> +}
>>> +
>>> +static void disable_usb9pfs(struct f_usb9pfs *usb9pfs)
>>> +{
>>> +    struct usb_composite_dev *cdev =
>>> +        usb9pfs->function.config->cdev;
>>> +
>>> +    disable_ep(cdev, usb9pfs->in_ep);
>>> +    disable_ep(cdev, usb9pfs->out_ep);
>>> +    dev_dbg(&cdev->gadget->dev, "%s disabled\n",
>>> +        usb9pfs->function.name);
>>> +}
>>> +
>>> +static int alloc_requests(struct usb_composite_dev *cdev,
>>> +              struct f_usb9pfs *usb9pfs)
>>> +{
>>> +    int ret = 0;
>>> +
>>> +    usb9pfs->in_req = usb_ep_alloc_request(usb9pfs->in_ep, GFP_ATOMIC);
>>> +    if (!usb9pfs->in_req) {
>>> +        ret = -ENOENT;
>>> +        goto fail;
>>> +    }
>>> +
>>> +    usb9pfs->out_req = alloc_ep_req(usb9pfs->out_ep, usb9pfs->buflen);
>>> +    if (!usb9pfs->out_req) {
>>> +        ret = -ENOENT;
>>> +        goto fail_in;
>>> +    }
>>> +
>>> +    usb9pfs->in_req->complete = usb9pfs_tx_complete;
>>> +    usb9pfs->out_req->complete = usb9pfs_rx_complete;
>>> +
>>> +    /* length will be set in complete routine */
>>> +    usb9pfs->in_req->context = usb9pfs;
>>> +    usb9pfs->out_req->context = usb9pfs;
>>> +
>>> +    return ret;
>>> +
>>> +fail_in:
>>> +    usb_ep_free_request(usb9pfs->in_ep, usb9pfs->in_req);
>>> +fail:
>>> +    return ret;
>>> +}
>>> +
>>> +static int enable_endpoint(struct usb_composite_dev *cdev,
>>> +               struct f_usb9pfs *usb9pfs, struct usb_ep *ep)
>>> +{
>>> +    int ret;
>>> +
>>> +    ret = config_ep_by_speed(cdev->gadget, &usb9pfs->function, ep);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    ret = usb_ep_enable(ep);
>>> +    if (ret < 0)
>>> +        return ret;
>>> +
>>> +    ep->driver_data = usb9pfs;
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static int
>>> +enable_usb9pfs(struct usb_composite_dev *cdev, struct f_usb9pfs *usb9pfs)
>>> +{
>>> +    int result = 0;
>>> +
>>> +    result = enable_endpoint(cdev, usb9pfs, usb9pfs->in_ep);
>>> +    if (result)
>>> +        goto out;
>>> +
>>> +    result = enable_endpoint(cdev, usb9pfs, usb9pfs->out_ep);
>>> +    if (result)
>>> +        goto disable_in;
>>> +
>>> +    result = alloc_requests(cdev, usb9pfs);
>>> +    if (result)
>>> +        goto disable_out;
>>> +
>>> +    dev_dbg(&cdev->gadget->dev, "%s enabled\n", usb9pfs->function.name);
>>> +    return 0;
>>> +
>>> +disable_out:
>>> +    usb_ep_disable(usb9pfs->out_ep);
>>> +disable_in:
>>> +    usb_ep_disable(usb9pfs->in_ep);
>>> +out:
>>> +    return result;
>>> +}
>>> +
>>> +static int p9_usbg_create(struct p9_client *client, const char *devname,
>>> char *args)
>>> +{
>>> +    struct usb_composite_dev *cdev;
>>> +    struct f_usb9pfs_dev *dev;
>>> +    struct f_usb9pfs_dev *tmp;
>>> +    struct f_usb9pfs *usb9pfs;
>>> +    struct usb_function *f;
>>> +    int ret = -ENOENT;
>>> +    int found = 0;
>>> +
>>> +    if (!devname)
>>> +        return -EINVAL;
>>> +
>>> +    mutex_lock(&usb9pfs_lock);
>>> +    list_for_each_entry_safe(dev, tmp, &usbg_instance_list, usb9pfs_instance) {
>>> +        if (!strncmp(devname, dev->tag, strlen(devname))) {
>>> +            if (!dev->inuse) {
>>> +                dev->inuse = true;
>>> +                found = 1;
>>> +                break;
>>> +            }
>>> +            ret = -EBUSY;
>>> +            break;
>>> +        }
>>> +    }
>>> +    mutex_unlock(&usb9pfs_lock);
>>> +
>>> +    if (!found) {
>>> +        pr_err("no channels available for device %s\n", devname);
>>> +        return ret;
>>> +    }
>>> +
>>> +    usb9pfs = dev->usb9pfs;
>>> +    if (!usb9pfs)
>>> +        return -EINVAL;
>>> +
>>> +    INIT_LIST_HEAD(&usb9pfs->tx_req_list);
>>> +
>>> +    spin_lock_init(&usb9pfs->lock);
>>> +    spin_lock_init(&usb9pfs->req_lock);
>>> +
>>> +    f = &usb9pfs->function;
>>> +    cdev = f->config->cdev;
>>> +
>>> +    client->trans = (void *)usb9pfs;
>>> +    client->status = Connected;
>>> +    usb9pfs->client = client;
>>> +
>>> +    client->trans_mod->maxsize = usb9pfs->buflen;
>>> +
>>> +    return enable_usb9pfs(cdev, usb9pfs);
>>> +}
>>> +
>>> +static void p9_usbg_close(struct p9_client *client)
>>> +{
>>> +    struct f_usb9pfs *usb9pfs;
>>> +    struct f_usb9pfs_dev *dev;
>>> +    struct p9_req_t *req;
>>> +    struct f_usb9pfs_opts *opts;
>>> +
>>> +    if (!client)
>>> +        return;
>>> +
>>> +    usb9pfs = client->trans;
>>> +    if (!usb9pfs)
>>> +        return;
>>> +
>>> +    client->status = Disconnected;
>>> +
>>> +    spin_lock(&usb9pfs->req_lock);
>>> +
>>> +    req = usb9pfs->p9_tx_req;
>>> +    if (req) {
>>> +        if (!req->t_err)
>>> +            req->t_err = -ECONNRESET;
>>> +        p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR);
>>> +    }
>>> +
>>> +    spin_unlock(&usb9pfs->req_lock);
>>> +
>>> +    disable_usb9pfs(usb9pfs);
>>> +
>>> +    opts = container_of(usb9pfs->function.fi,
>>> +                struct f_usb9pfs_opts, func_inst);
>>> +
>>> +    dev = opts->dev;
>>> +
>>> +    mutex_lock(&usb9pfs_lock);
>>> +    dev->inuse = false;
>>> +    mutex_unlock(&usb9pfs_lock);
>>> +}
>>> +
>>> +static int p9_usbg_request(struct p9_client *client, struct p9_req_t *p9_req)
>>> +{
>>> +    struct f_usb9pfs *usb9pfs = client->trans;
>>> +    unsigned long flags;
>>> +
>>> +    if (client->status != Connected)
>>> +        return -EBUSY;
>>> +
>>> +    spin_lock_irqsave(&usb9pfs->lock, flags);
>>> +    list_add_tail(&p9_req->req_list, &usb9pfs->tx_req_list);
>>> +    spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>> +
>>> +    spin_lock_irqsave(&usb9pfs->req_lock, flags);
>>> +    usb9pfs_transmit(usb9pfs);
>>> +    spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int p9_usbg_cancel(struct p9_client *client, struct p9_req_t *req)
>>> +{
>>> +    struct f_usb9pfs *usb9pfs = client->trans;
>>> +    int ret = 1;
>>> +
>>> +    p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
>>> +
>>> +    spin_lock(&usb9pfs->req_lock);
>>> +
>>> +    if (req->status == REQ_STATUS_UNSENT) {
>>> +        list_del(&req->req_list);
>>> +        WRITE_ONCE(req->status, REQ_STATUS_FLSHD);
>>> +        p9_req_put(client, req);
>>> +        ret = 0;
>>> +    }
>>> +    spin_unlock(&usb9pfs->req_lock);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static struct p9_trans_module p9_usbg_trans = {
>>> +    .name = "usbg",
>>> +    .create = p9_usbg_create,
>>> +    .close = p9_usbg_close,
>>> +    .request = p9_usbg_request,
>>> +    .cancel = p9_usbg_cancel,
>>> +    .owner = THIS_MODULE,
>>> +};
>>> +
>>> +/*-------------------------------------------------------------------------*/
>>> +
>>> +#define USB_PROTOCOL_9PFS    0x09
>>> +
>>> +static struct usb_interface_descriptor usb9pfs_intf = {
>>> +    .bLength =        sizeof(usb9pfs_intf),
>>> +    .bDescriptorType =    USB_DT_INTERFACE,
>>> +
>>> +    .bNumEndpoints =    2,
>>> +    .bInterfaceClass =    USB_CLASS_VENDOR_SPEC,
>>> +    .bInterfaceSubClass =    USB_SUBCLASS_VENDOR_SPEC,
>>> +    .bInterfaceProtocol =   USB_PROTOCOL_9PFS,
>>> +
>>> +    /* .iInterface = DYNAMIC */
>>> +};
>>> +
>>> +/* full speed support: */
>>> +
>>> +static struct usb_endpoint_descriptor fs_usb9pfs_source_desc = {
>>> +    .bLength =        USB_DT_ENDPOINT_SIZE,
>>> +    .bDescriptorType =    USB_DT_ENDPOINT,
>>> +
>>> +    .bEndpointAddress =    USB_DIR_IN,
>>> +    .bmAttributes =        USB_ENDPOINT_XFER_BULK,
>>> +};
>>> +
>>> +static struct usb_endpoint_descriptor fs_usb9pfs_sink_desc = {
>>> +    .bLength =        USB_DT_ENDPOINT_SIZE,
>>> +    .bDescriptorType =    USB_DT_ENDPOINT,
>>> +
>>> +    .bEndpointAddress =    USB_DIR_OUT,
>>> +    .bmAttributes =        USB_ENDPOINT_XFER_BULK,
>>> +};
>>> +
>>> +static struct usb_descriptor_header *fs_usb9pfs_descs[] = {
>>> +    (struct usb_descriptor_header *)&usb9pfs_intf,
>>> +    (struct usb_descriptor_header *)&fs_usb9pfs_sink_desc,
>>> +    (struct usb_descriptor_header *)&fs_usb9pfs_source_desc,
>>> +    NULL,
>>> +};
>>> +
>>> +/* high speed support: */
>>> +
>>> +static struct usb_endpoint_descriptor hs_usb9pfs_source_desc = {
>>> +    .bLength =        USB_DT_ENDPOINT_SIZE,
>>> +    .bDescriptorType =    USB_DT_ENDPOINT,
>>> +
>>> +    .bmAttributes =        USB_ENDPOINT_XFER_BULK,
>>> +    .wMaxPacketSize =    cpu_to_le16(512),
>>> +};
>>> +
>>> +static struct usb_endpoint_descriptor hs_usb9pfs_sink_desc = {
>>> +    .bLength =        USB_DT_ENDPOINT_SIZE,
>>> +    .bDescriptorType =    USB_DT_ENDPOINT,
>>> +
>>> +    .bmAttributes =        USB_ENDPOINT_XFER_BULK,
>>> +    .wMaxPacketSize =    cpu_to_le16(512),
>>> +};
>>> +
>>> +static struct usb_descriptor_header *hs_usb9pfs_descs[] = {
>>> +    (struct usb_descriptor_header *)&usb9pfs_intf,
>>> +    (struct usb_descriptor_header *)&hs_usb9pfs_source_desc,
>>> +    (struct usb_descriptor_header *)&hs_usb9pfs_sink_desc,
>>> +    NULL,
>>> +};
>>> +
>>> +/* super speed support: */
>>> +
>>> +static struct usb_endpoint_descriptor ss_usb9pfs_source_desc = {
>>> +    .bLength =        USB_DT_ENDPOINT_SIZE,
>>> +    .bDescriptorType =    USB_DT_ENDPOINT,
>>> +
>>> +    .bmAttributes =        USB_ENDPOINT_XFER_BULK,
>>> +    .wMaxPacketSize =    cpu_to_le16(1024),
>>> +};
>>> +
>>> +static struct usb_ss_ep_comp_descriptor ss_usb9pfs_source_comp_desc = {
>>> +    .bLength =        USB_DT_SS_EP_COMP_SIZE,
>>> +    .bDescriptorType =    USB_DT_SS_ENDPOINT_COMP,
>>> +    .bMaxBurst =        0,
>>> +    .bmAttributes =        0,
>>> +    .wBytesPerInterval =    0,
>>> +};
>>> +
>>> +static struct usb_endpoint_descriptor ss_usb9pfs_sink_desc = {
>>> +    .bLength =        USB_DT_ENDPOINT_SIZE,
>>> +    .bDescriptorType =    USB_DT_ENDPOINT,
>>> +
>>> +    .bmAttributes =        USB_ENDPOINT_XFER_BULK,
>>> +    .wMaxPacketSize =    cpu_to_le16(1024),
>>> +};
>>> +
>>> +static struct usb_ss_ep_comp_descriptor ss_usb9pfs_sink_comp_desc = {
>>> +    .bLength =        USB_DT_SS_EP_COMP_SIZE,
>>> +    .bDescriptorType =    USB_DT_SS_ENDPOINT_COMP,
>>> +    .bMaxBurst =        0,
>>> +    .bmAttributes =        0,
>>> +    .wBytesPerInterval =    0,
>>> +};
>>> +
>>> +static struct usb_descriptor_header *ss_usb9pfs_descs[] = {
>>> +    (struct usb_descriptor_header *)&usb9pfs_intf,
>>> +    (struct usb_descriptor_header *)&ss_usb9pfs_source_desc,
>>> +    (struct usb_descriptor_header *)&ss_usb9pfs_source_comp_desc,
>>> +    (struct usb_descriptor_header *)&ss_usb9pfs_sink_desc,
>>> +    (struct usb_descriptor_header *)&ss_usb9pfs_sink_comp_desc,
>>> +    NULL,
>>> +};
>>> +
>>> +/* function-specific strings: */
>>> +static struct usb_string strings_usb9pfs[] = {
>>> +    [0].s = "usb9pfs input to output",
>>> +    {  }            /* end of list */
>>> +};
>>> +
>>> +static struct usb_gadget_strings stringtab_usb9pfs = {
>>> +    .language    = 0x0409,    /* en-us */
>>> +    .strings    = strings_usb9pfs,
>>> +};
>>> +
>>> +static struct usb_gadget_strings *usb9pfs_strings[] = {
>>> +    &stringtab_usb9pfs,
>>> +    NULL,
>>> +};
>>> +
>>> +/*-------------------------------------------------------------------------*/
>>> +
>>> +static int usb9pfs_func_bind(struct usb_configuration *c,
>>> +                 struct usb_function *f)
>>> +{
>>> +    struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
>>> +    struct f_usb9pfs_opts *opts;
>>> +    struct usb_composite_dev *cdev = c->cdev;
>>> +    int ret;
>>> +    int id;
>>> +
>>> +    /* allocate interface ID(s) */
>>> +    id = usb_interface_id(c, f);
>>> +    if (id < 0)
>>> +        return id;
>>> +    usb9pfs_intf.bInterfaceNumber = id;
>>> +
>>> +    id = usb_string_id(cdev);
>>> +    if (id < 0)
>>> +        return id;
>>> +    strings_usb9pfs[0].id = id;
>>> +    usb9pfs_intf.iInterface = id;
>>> +
>>> +    /* allocate endpoints */
>>> +    usb9pfs->in_ep = usb_ep_autoconfig(cdev->gadget,
>>> +                       &fs_usb9pfs_source_desc);
>>> +    if (!usb9pfs->in_ep)
>>> +        goto autoconf_fail;
>>> +
>>> +    usb9pfs->out_ep = usb_ep_autoconfig(cdev->gadget,
>>> +                        &fs_usb9pfs_sink_desc);
>>> +    if (!usb9pfs->out_ep)
>>> +        goto autoconf_fail;
>>> +
>>> +    /* support high speed hardware */
>>> +    hs_usb9pfs_source_desc.bEndpointAddress =
>>> +        fs_usb9pfs_source_desc.bEndpointAddress;
>>> +    hs_usb9pfs_sink_desc.bEndpointAddress =
>>> +        fs_usb9pfs_sink_desc.bEndpointAddress;
>>> +
>>> +    /* support super speed hardware */
>>> +    ss_usb9pfs_source_desc.bEndpointAddress =
>>> +        fs_usb9pfs_source_desc.bEndpointAddress;
>>> +    ss_usb9pfs_sink_desc.bEndpointAddress =
>>> +        fs_usb9pfs_sink_desc.bEndpointAddress;
>>> +
>>> +    ret = usb_assign_descriptors(f, fs_usb9pfs_descs, hs_usb9pfs_descs,
>>> +                     ss_usb9pfs_descs, ss_usb9pfs_descs);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst);
>>> +    opts->dev->usb9pfs = usb9pfs;
>>> +
>>> +    dev_dbg(&cdev->gadget->dev, "%s speed %s: IN/%s, OUT/%s\n",
>>> +        (gadget_is_superspeed(c->cdev->gadget) ? "super" :
>>> +        (gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")),
>>> +            f->name, usb9pfs->in_ep->name, usb9pfs->out_ep->name);
>>> +
>>> +    return 0;
>>> +
>>> +autoconf_fail:
>>> +    ERROR(cdev, "%s: can't autoconfigure on %s\n",
>>> +          f->name, cdev->gadget->name);
>>> +    return -ENODEV;
>>> +}
>>> +
>>> +static void usb9pfs_free_func(struct usb_function *f)
>>> +{
>>> +    struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
>>> +    struct f_usb9pfs_opts *opts;
>>> +
>>> +    kfree(usb9pfs);
>>> +
>>> +    opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst);
>>> +
>>> +    mutex_lock(&opts->lock);
>>> +    opts->refcnt--;
>>> +    mutex_unlock(&opts->lock);
>>> +
>>> +    usb_free_all_descriptors(f);
>>> +}
>>> +
>>> +static int usb9pfs_set_alt(struct usb_function *f,
>>> +               unsigned int intf, unsigned int alt)
>>> +{
>>> +    return 0;
>>> +}
>>> +
>>> +static void usb9pfs_disable(struct usb_function *f)
>>> +{
>>> +    struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
>>> +    struct p9_req_t *req;
>>> +
>>> +    spin_lock(&usb9pfs->req_lock);
>>> +
>>> +    req = usb9pfs->p9_tx_req;
>>> +
>>> +    if (!req->t_err)
>>> +        req->t_err = -ECONNRESET;
>>> +    p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR);
>>> +
>>> +    spin_unlock(&usb9pfs->req_lock);
>>> +}
>>> +
>>> +static struct usb_function *usb9pfs_alloc(struct usb_function_instance *fi)
>>> +{
>>> +    struct f_usb9pfs_opts *usb9pfs_opts;
>>> +    struct f_usb9pfs *usb9pfs;
>>> +
>>> +    usb9pfs = kzalloc(sizeof(*usb9pfs), GFP_KERNEL);
>>> +    if (!usb9pfs)
>>> +        return ERR_PTR(-ENOMEM);
>>> +
>>> +    usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
>>> +
>>> +    mutex_lock(&usb9pfs_opts->lock);
>>> +    usb9pfs_opts->refcnt++;
>>> +    mutex_unlock(&usb9pfs_opts->lock);
>>> +
>>> +    usb9pfs->buflen = usb9pfs_opts->buflen;
>>> +
>>> +    usb9pfs->function.name = "usb9pfs";
>>> +    usb9pfs->function.bind = usb9pfs_func_bind;
>>> +    usb9pfs->function.set_alt = usb9pfs_set_alt;
>>> +    usb9pfs->function.disable = usb9pfs_disable;
>>> +    usb9pfs->function.strings = usb9pfs_strings;
>>> +
>>> +    usb9pfs->function.free_func = usb9pfs_free_func;
>>> +
>>> +    return &usb9pfs->function;
>>> +}
>>> +
>>> +static inline struct f_usb9pfs_opts *to_f_usb9pfs_opts(struct config_item
>>> *item)
>>> +{
>>> +    return container_of(to_config_group(item), struct f_usb9pfs_opts,
>>> +                func_inst.group);
>>> +}
>>> +
>>> +static inline struct f_usb9pfs_opts *fi_to_f_usb9pfs_opts(struct
>>> usb_function_instance *fi)
>>> +{
>>> +    return container_of(fi, struct f_usb9pfs_opts, func_inst);
>>> +}
>>> +
>>> +static void usb9pfs_attr_release(struct config_item *item)
>>> +{
>>> +    struct f_usb9pfs_opts *usb9pfs_opts = to_f_usb9pfs_opts(item);
>>> +
>>> +    usb_put_function_instance(&usb9pfs_opts->func_inst);
>>> +}
>>> +
>>> +static struct configfs_item_operations usb9pfs_item_ops = {
>>> +    .release        = usb9pfs_attr_release,
>>> +};
>>> +
>>> +static ssize_t f_usb9pfs_opts_buflen_show(struct config_item *item, char *page)
>>> +{
>>> +    struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
>>> +    int result;
>>> +
>>> +    mutex_lock(&opts->lock);
>>> +    result = sprintf(page, "%d\n", opts->buflen);
>>> +    mutex_unlock(&opts->lock);
>>> +
>>> +    return result;
>>> +}
>>> +
>>> +static ssize_t f_usb9pfs_opts_buflen_store(struct config_item *item,
>>> +                       const char *page, size_t len)
>>> +{
>>> +    struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
>>> +    int ret;
>>> +    u32 num;
>>> +
>>> +    mutex_lock(&opts->lock);
>>> +    if (opts->refcnt) {
>>> +        ret = -EBUSY;
>>> +        goto end;
>>> +    }
>>> +
>>> +    ret = kstrtou32(page, 0, &num);
>>> +    if (ret)
>>> +        goto end;
>>> +
>>> +    opts->buflen = num;
>>> +    ret = len;
>>> +end:
>>> +    mutex_unlock(&opts->lock);
>>> +    return ret;
>>> +}
>>> +
>>> +CONFIGFS_ATTR(f_usb9pfs_opts_, buflen);
>>> +
>>> +static struct configfs_attribute *usb9pfs_attrs[] = {
>>> +    &f_usb9pfs_opts_attr_buflen,
>>> +    NULL,
>>> +};
>>> +
>>> +static const struct config_item_type usb9pfs_func_type = {
>>> +    .ct_item_ops    = &usb9pfs_item_ops,
>>> +    .ct_attrs    = usb9pfs_attrs,
>>> +    .ct_owner    = THIS_MODULE,
>>> +};
>>> +
>>> +static struct f_usb9pfs_dev *_usb9pfs_do_find_dev(const char *tag)
>>> +{
>>> +    struct f_usb9pfs_dev *usb9pfs_dev;
>>> +    struct f_usb9pfs_dev *tmp;
>>> +
>>> +    if (!tag)
>>> +        return NULL;
>>> +
>>> +    list_for_each_entry_safe(usb9pfs_dev, tmp, &usbg_instance_list,
>>> usb9pfs_instance) {
>>> +        if (strcmp(usb9pfs_dev->tag, tag) == 0)
>>> +            return usb9pfs_dev;
>>> +    }
>>> +
>>> +    return NULL;
>>> +}
>>> +
>>> +static int usb9pfs_tag_instance(struct f_usb9pfs_dev *dev, const char *tag)
>>> +{
>>> +    struct f_usb9pfs_dev *existing;
>>> +    int ret = 0;
>>> +
>>> +    mutex_lock(&usb9pfs_lock);
>>> +    existing = _usb9pfs_do_find_dev(tag);
>>> +    if (!existing)
>>> +        strscpy(dev->tag, tag, ARRAY_SIZE(dev->tag));
>>> +    else if (existing != dev)
>>> +        ret = -EBUSY;
>>> +    mutex_unlock(&usb9pfs_lock);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static int usb9pfs_set_inst_tag(struct usb_function_instance *fi, const char
>>> *tag)
>>> +{
>>> +    if (strlen(tag) >= sizeof_field(struct f_usb9pfs_dev, tag))
>>> +        return -ENAMETOOLONG;
>>> +    return usb9pfs_tag_instance(fi_to_f_usb9pfs_opts(fi)->dev, tag);
>>> +}
>>> +
>>> +static void usb9pfs_free_instance(struct usb_function_instance *fi)
>>> +{
>>> +    struct f_usb9pfs_opts *usb9pfs_opts;
>>> +
>>> +    usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
>>> +    kfree(usb9pfs_opts);
>>> +}
>>> +
>>> +static struct usb_function_instance *usb9pfs_alloc_instance(void)
>>> +{
>>> +    struct f_usb9pfs_opts *usb9pfs_opts;
>>> +    struct f_usb9pfs_dev *dev;
>>> +
>>> +    usb9pfs_opts = kzalloc(sizeof(*usb9pfs_opts), GFP_KERNEL);
>>> +    if (!usb9pfs_opts)
>>> +        return ERR_PTR(-ENOMEM);
>>> +
>>> +    mutex_init(&usb9pfs_opts->lock);
>>> +
>>> +    usb9pfs_opts->func_inst.set_inst_name = usb9pfs_set_inst_tag;
>>> +    usb9pfs_opts->func_inst.free_func_inst = usb9pfs_free_instance;
>>> +
>>> +    usb9pfs_opts->buflen = DEFAULT_BUFLEN;
>>> +
>>> +    mutex_lock(&usb9pfs_lock);
>>> +    dev = kzalloc(sizeof(*dev), GFP_KERNEL);
>>> +    if (IS_ERR(dev)) {
>>> +        mutex_unlock(&usb9pfs_lock);
>>> +        kfree(usb9pfs_opts);
>>> +        return ERR_CAST(dev);
>>> +    }
>>> +    list_add_tail(&dev->usb9pfs_instance, &usbg_instance_list);
>>> +    mutex_unlock(&usb9pfs_lock);
>>> +
>>> +    usb9pfs_opts->dev = dev;
>>> +    dev->opts = usb9pfs_opts;
>>> +
>>> +    config_group_init_type_name(&usb9pfs_opts->func_inst.group, "",
>>> +                    &usb9pfs_func_type);
>>> +
>>> +    return &usb9pfs_opts->func_inst;
>>> +}
>>> +DECLARE_USB_FUNCTION(usb9pfs, usb9pfs_alloc_instance, usb9pfs_alloc);
>>> +
>>> +static int __init usb9pfs_modinit(void)
>>> +{
>>> +    int ret;
>>> +
>>> +    INIT_LIST_HEAD(&usbg_instance_list);
>>> +
>>> +    ret = usb_function_register(&usb9pfsusb_func);
>>> +    if (!ret)
>>> +        v9fs_register_trans(&p9_usbg_trans);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static void __exit usb9pfs_modexit(void)
>>> +{
>>> +    usb_function_unregister(&usb9pfsusb_func);
>>> +    v9fs_unregister_trans(&p9_usbg_trans);
>>> +}
>>> +
>>> +module_init(usb9pfs_modinit);
>>> +module_exit(usb9pfs_modexit);
>>> +
>>> +MODULE_ALIAS_9P("usbg");
>>> +MODULE_LICENSE("GPL");
>>> +MODULE_DESCRIPTION("USB gadget 9pfs transport");
>>> +MODULE_AUTHOR("Michael Grzeschik");
>>>
>>
>>
>


2024-05-16 18:49:32

by Michael Grzeschik

[permalink] [raw]
Subject: Re: [PATCH v4 2/3] net/9p/usbg: Add new usb gadget function transport

Hi

On Fri, May 10, 2024 at 04:11:27PM +0200, Andrzej Pietrasiewicz wrote:
>W dniu 10.05.2024 o?12:11, Michael Grzeschik pisze:
>>On Fri, May 10, 2024 at 11:25:47AM +0200, Andrzej Pietrasiewicz wrote:
>>>Hi Michael,
>>>
>>>W dniu 30.04.2024 o?01:33, Michael Grzeschik pisze:
>>>>Add the new gadget function for 9pfs transport. This function is
>>>>defining an simple 9pfs transport interface that consists of one in and
>>>>one out endpoint. The endpoints transmit and receive the 9pfs protocol
>>>>payload when mounting a 9p filesystem over usb.
>>>>
>>>>Signed-off-by: Michael Grzeschik <[email protected]>
>>>>
>>>>---
>>>>v3 -> v4:
>>>>? - implemented conn_cancel
>>>
>>>I tried this scenario:
>>>
>>>1) run all the components and have 9pfs up and running
>>>2) stop the forwarder
>>>3) umount -f at the gadget side - this indeed succeeds now in v4
>>>4) start the forwarder again
>>>5) mount at the gadget side - this hangs.
>>>
>>>Did this scenario work for you?
>>
>>I actually tested this exact scenario. So this is
>>suprising. I will try this again just to be sure
>>that I did send the latest version.
>>
>>My latest testsetup included the dummy_hcd. Did you test on real hardware?
>
>Yes, I did.

I just also tested this again on real hardware. With the imx6 chipidea
udc I indeed see that this is stuck after the first round of mount and
remount. With the musb core on the beaglebone this seems to be fine.

While debugging this I also ran into some shutdown issues and lockdep
issues I see because the complete handler is possible to be resumed
immedeatly on musb, which is odd. However I fixed/fix them and send an
v5 afterwards.

Regarding the hang on the imx6, which hardware did you test this on?

Michael

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2024-05-16 19:52:02

by Michael Grzeschik

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Subject: Re: [PATCH v4 2/3] net/9p/usbg: Add new usb gadget function transport

On Thu, May 16, 2024 at 08:49:02PM +0200, Michael Grzeschik wrote:
>Hi
>
>On Fri, May 10, 2024 at 04:11:27PM +0200, Andrzej Pietrasiewicz wrote:
>>W dniu 10.05.2024 o?12:11, Michael Grzeschik pisze:
>>>On Fri, May 10, 2024 at 11:25:47AM +0200, Andrzej Pietrasiewicz wrote:
>>>>Hi Michael,
>>>>
>>>>W dniu 30.04.2024 o?01:33, Michael Grzeschik pisze:
>>>>>Add the new gadget function for 9pfs transport. This function is
>>>>>defining an simple 9pfs transport interface that consists of one in and
>>>>>one out endpoint. The endpoints transmit and receive the 9pfs protocol
>>>>>payload when mounting a 9p filesystem over usb.
>>>>>
>>>>>Signed-off-by: Michael Grzeschik <[email protected]>
>>>>>
>>>>>---
>>>>>v3 -> v4:
>>>>>? - implemented conn_cancel
>>>>
>>>>I tried this scenario:
>>>>
>>>>1) run all the components and have 9pfs up and running
>>>>2) stop the forwarder
>>>>3) umount -f at the gadget side - this indeed succeeds now in v4
>>>>4) start the forwarder again
>>>>5) mount at the gadget side - this hangs.
>>>>
>>>>Did this scenario work for you?
>>>
>>>I actually tested this exact scenario. So this is
>>>suprising. I will try this again just to be sure
>>>that I did send the latest version.
>>>
>>>My latest testsetup included the dummy_hcd. Did you test on real hardware?
>>
>>Yes, I did.
>
>I just also tested this again on real hardware. With the imx6 chipidea
>udc I indeed see that this is stuck after the first round of mount and
>remount. With the musb core on the beaglebone this seems to be fine.
>
>While debugging this I also ran into some shutdown issues and lockdep
>issues I see because the complete handler is possible to be resumed
>immedeatly on musb, which is odd. However I fixed/fix them and send an
>v5 afterwards.
>
>Regarding the hang on the imx6, which hardware did you test this on?

Nevermind. I can also reproduce the hang with the musb.

Michael

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2024-05-28 05:20:05

by Michael Grzeschik

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Subject: Re: [PATCH v4 3/3] tools: usb: p9_fwd: add usb gadget packet forwarder script

On Fri, May 10, 2024 at 10:32:11AM +0200, Andrzej Pietrasiewicz wrote:
>Hi Michael,
>
>W dniu 10.05.2024 o?10:29, Andrzej Pietrasiewicz pisze:
>>Hi Michael,
>>
>>W dniu 30.04.2024 o?01:33, Michael Grzeschik pisze:
>>>This patch is adding an small python tool to forward 9pfs requests
>>>from the USB gadget to an existing 9pfs TCP server. Since currently all
>>>9pfs servers lack support for the usb transport this tool is an useful
>>>helper to get started.
>>>
>>>Refer the Documentation section "USBG Example" in
>>>Documentation/filesystems/9p.rst on how to use it.
>>>
>>>Signed-off-by: Michael Grzeschik <[email protected]>
>>>
>>>---
>>>v3 -> v4: -
>>>v2 -> v3: -
>>>v1 -> v2:
>>>?? - added usbg 9pfs detailed instructions to 9p.rst doc
>>>---
>>>? Documentation/filesystems/9p.rst |? 32 +++++++
>>>? tools/usb/p9_fwd.py????????????? | 194 +++++++++++++++++++++++++++++++++++++++
>>>? 2 files changed, 226 insertions(+)
>>>
>>>diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst
>>>index 10cf79dc287f8..2467f1ea4a150 100644
>>>--- a/Documentation/filesystems/9p.rst
>>>+++ b/Documentation/filesystems/9p.rst
>>>@@ -67,6 +67,38 @@ To mount a 9p FS on a USB Host accessible via
>>>the gadget as root filesystem::
>>>? where <device> is the tag associated by the usb gadget transport.
>>>? It is defined by the configfs instance name.
>>>+USBG Example
>>>+============
>>>+
>>>+The USB host exports a filesystem, while the gadget on the USB device
>>>+side makes it mountable.
>>>+
>>>+Diod (9pfs server) and the forwarder are on the development host, where
>>>+the root filesystem is actually stored. The gadget is initialized during
>>>+boot (or later) on the embedded board. Then the forwarder will find it
>>>+on the USB bus and start forwarding requests.
>>>+
>>>+In this case the 9p requests come from the device and are handled by the
>>>+host. The reason is that USB device ports are normally not available on
>>>+PCs, so a connection in the other direction would not work.
>>>+
>>>+When using the usbg transport, for now there is no native usb host
>>>+service capable to handle the requests from the gadget driver. For
>>>+this we have to use the extra python tool p9_fwd.py from tools/usb.
>>>+
>>>+Just start the 9pfs capable network server like diod/nfs-ganesha e.g.:
>>>+
>>>+??? $ diod -f -n -d 0 -S -l 0.0.0.0:9999 -e $PWD
>>>+
>>>+Then start the python transport:
>>>+
>>>+??? $ python $kernel_dir/tools/usb/p9_fwd.py -p 9999
>>>+
>>>+After that the gadget driver can be used as described above.
>>>+
>>>+One use-case is to use it as an alternative to NFS root booting during
>>>+the development of embedded Linux devices.
>>>+
>>>? Options
>>>? =======
>>>diff --git a/tools/usb/p9_fwd.py b/tools/usb/p9_fwd.py
>>>new file mode 100755
>>>index 0000000000000..95208df11abef
>>>--- /dev/null
>>>+++ b/tools/usb/p9_fwd.py
>>>@@ -0,0 +1,194 @@
>>>+#!/usr/bin/env python3
>>>+# SPDX-License-Identifier: GPL-2.0
>>>+
>>>+import argparse
>>>+import errno
>>>+import logging
>>>+import socket
>>>+import struct
>>>+import sys
>>>+import time
>>>+
>>>+import usb.core
>>>+import usb.util
>>>+
>>>+
>>>+class Forwarder:
>>>+??? HEXDUMP_FILTER = (
>>>+??????? "".join(chr(x).isprintable() and chr(x) or "." for x in
>>>range(128)) + "." * 128
>>>+??? )
>>>+
>>>+??? @staticmethod
>>>+??? def _log_hexdump(data):
>>>+??????? if not logging.root.isEnabledFor(logging.TRACE):
>>>+??????????? return
>>>+??????? L = 16
>>>+??????? for c in range(0, len(data), L):
>>>+??????????? chars = data[c : c + L]
>>>+??????????? dump = " ".join(f"{x:02x}" for x in chars)
>>>+??????????? printable = "".join(HEXDUMP_FILTER[x] for x in chars)
>>>+??????????? line = f"{c:08x}? {dump:{L*3}s} |{printable:{L}s}|"
>>>+??????????? logging.root.log(logging.TRACE, "%s", line)
>>>+
>>>+??? def __init__(self, server):
>>>+??????? self.stats = {
>>>+??????????? "c2s packets": 0,
>>>+??????????? "c2s bytes": 0,
>>>+??????????? "s2c packets": 0,
>>>+??????????? "s2c bytes": 0,
>>>+??????? }
>>>+??????? self.stats_logged = time.monotonic()
>>>+
>>>+??????? dev = usb.core.find(idVendor=0x1D6B, idProduct=0x0109)
>>
>>Is this idProduct an assigned number? I can't find it in
>>http://www.linux-usb.org/usb.ids. The "9" is obviously a pun on 9pfs,
>>a nice trick and it would make sense.
>>
>>However, given composition with configfs there's no guarantee that 9pfs will be
>>the only USB gadget function present, and so it is not quite clear that Linux
>>Foundation's vendor and product ids are always appropriate. What's more, when
>>you are not going to the market with products you can use whatever ids you
>>please for your own use.
>>
>>Given the above, I'd love these two (idVendor and idProduct) to be commandline
>>parameters of this script. My user story: whenever I created a gadget with
>>configfs it had different ids than the above and this script wouldn't work.
>
>And actually it is perfectly possible to have more than one USB device with
>_the same_ vendor and product ids connected. How would this script behave if
>that's the case?

I updated the script in v5 to support the subcommand "list" to show all
available devices and their usb path. Together with the configurable
option to select the vid/pid it is now possibleto address the exact
device you want to forward.

https://lore.kernel.org/all/[email protected]/

Regards,
Michael


>>>+??????? if dev is None:
>>>+??????????? raise ValueError("Device not found")
>>>+
>>>+??????? logging.info(f"found device: {dev.bus}/{dev.address}")
>>>+
>>>+??????? # dev.set_configuration() is not necessary since g_multi has only one
>>>+??????? usb9pfs = None
>>>+??????? # g_multi adds 9pfs as last interface
>>>+??????? cfg = dev.get_active_configuration()
>>>+??????? for intf in cfg:
>>>+??????????? # we have to detach the usb-storage driver from multi gadget since
>>>+??????????? # stall option could be set, which will lead to spontaneous port
>>>+??????????? # resets and our transfers will run dead
>>>+??????????? if intf.bInterfaceClass == 0x08:
>>>+??????????????? if dev.is_kernel_driver_active(intf.bInterfaceNumber):
>>>+??????????????????? dev.detach_kernel_driver(intf.bInterfaceNumber)
>>>+
>>>+??????????? if (
>>>+??????????????? intf.bInterfaceClass == 0xFF
>>>+??????????????? and intf.bInterfaceSubClass == 0xFF
>>>+??????????????? and intf.bInterfaceProtocol == 0x09
>>>+??????????? ):
>>>+??????????????? usb9pfs = intf
>>>+??????? if usb9pfs is None:
>>>+??????????? raise ValueError("Interface not found")
>>>+
>>>+??????? logging.info(f"claiming interface:\n{usb9pfs}")
>>>+??????? usb.util.claim_interface(dev, usb9pfs.bInterfaceNumber)
>>>+??????? ep_out = usb.util.find_descriptor(
>>>+??????????? usb9pfs,
>>>+??????????? custom_match=lambda e:
>>>usb.util.endpoint_direction(e.bEndpointAddress)
>>>+??????????? == usb.util.ENDPOINT_OUT,
>>>+??????? )
>>>+??????? assert ep_out is not None
>>>+??????? ep_in = usb.util.find_descriptor(
>>>+??????????? usb9pfs,
>>>+??????????? custom_match=lambda e:
>>>usb.util.endpoint_direction(e.bEndpointAddress)
>>>+??????????? == usb.util.ENDPOINT_IN,
>>>+??????? )
>>>+??????? assert ep_in is not None
>>>+??????? logging.info(f"interface claimed")
>>>+
>>>+??????? self.ep_out = ep_out
>>>+??????? self.ep_in = ep_in
>>>+??????? self.dev = dev
>>>+
>>>+??????? # create and connect socket
>>>+??????? self.s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
>>>+??????? self.s.connect(server)
>>>+
>>>+??????? logging.info(f"connected to server")
>>>+
>>>+??? def c2s(self):
>>>+??????? """forward a request from the USB client to the TCP server"""
>>>+??????? data = None
>>>+??????? while data is None:
>>>+??????????? try:
>>>+??????????????? logging.log(logging.TRACE, "c2s: reading")
>>>+??????????????? data = self.ep_in.read(self.ep_in.wMaxPacketSize)
>>>+??????????? except usb.core.USBTimeoutError:
>>>+??????????????? logging.log(logging.TRACE, "c2s: reading timed out")
>>>+??????????????? continue
>>>+??????????? except usb.core.USBError as e:
>>>+??????????????? if e.errno == errno.EIO:
>>>+??????????????????? logging.debug("c2s: reading failed with %s,
>>>retrying", repr(e))
>>>+??????????????????? time.sleep(0.5)
>>>+??????????????????? continue
>>>+??????????????? else:
>>>+??????????????????? logging.error("c2s: reading failed with %s,
>>>aborting", repr(e))
>>>+??????????????????? raise
>>>+??????? size = struct.unpack("<I", data[:4])[0]
>>>+??????? while len(data) < size:
>>>+??????????? data += self.ep_in.read(size - len(data))
>>>+??????? logging.log(logging.TRACE, "c2s: writing")
>>>+??????? self._log_hexdump(data)
>>>+??????? self.s.send(data)
>>>+??????? logging.debug("c2s: forwarded %i bytes", size)
>>>+??????? self.stats["c2s packets"] += 1
>>>+??????? self.stats["c2s bytes"] += size
>>>+
>>>+??? def s2c(self):
>>>+??????? """forward a response from the TCP server to the USB client"""
>>>+??????? logging.log(logging.TRACE, "s2c: reading")
>>>+??????? data = self.s.recv(4)
>>>+??????? size = struct.unpack("<I", data[:4])[0]
>>>+??????? while len(data) < size:
>>>+??????????? data += self.s.recv(size - len(data))
>>>+??????? logging.log(logging.TRACE, "s2c: writing")
>>>+??????? self._log_hexdump(data)
>>>+??????? while data:
>>>+??????????? written = self.ep_out.write(data)
>>>+??????????? assert written > 0
>>>+??????????? data = data[written:]
>>>+??????? if size % self.ep_out.wMaxPacketSize == 0:
>>>+??????????? logging.log(logging.TRACE, "sending zero length packet")
>>>+??????????? self.ep_out.write(b"")
>>>+??????? logging.debug("s2c: forwarded %i bytes", size)
>>>+??????? self.stats["s2c packets"] += 1
>>>+??????? self.stats["s2c bytes"] += size
>>>+
>>>+??? def log_stats(self):
>>>+??????? logging.info("statistics:")
>>>+??????? for k, v in self.stats.items():
>>>+??????????? logging.info(f"? {k+':':14s} {v}")
>>>+
>>>+??? def log_stats_interval(self, interval=5):
>>>+??????? if (time.monotonic() - self.stats_logged) < interval:
>>>+??????????? return
>>>+
>>>+??????? self.log_stats()
>>>+??????? self.stats_logged = time.monotonic()
>>>+
>>>+
>>>+def main():
>>>+??? parser = argparse.ArgumentParser(
>>>+??????? description="Forward 9PFS requests from USB to TCP",
>>>+??? )
>>>+
>>>+??? parser.add_argument(
>>>+??????? "-s", "--server", type=str, default="127.0.0.1", help="server hostname"
>>>+??? )
>>>+??? parser.add_argument("-p", "--port", type=int, default=564,
>>>help="server port")
>>>+??? parser.add_argument("-v", "--verbose", action="count", default=0)
>>>+
>>>+??? args = parser.parse_args()
>>>+
>>>+??? logging.TRACE = logging.DEBUG - 5
>>>+??? logging.addLevelName(logging.TRACE, "TRACE")
>>>+
>>>+??? if args.verbose >= 2:
>>>+??????? level = logging.TRACE
>>>+??? elif args.verbose:
>>>+??????? level = logging.DEBUG
>>>+??? else:
>>>+??????? level = logging.INFO
>>>+??? logging.basicConfig(
>>>+??????? level=level, format="%(asctime)-15s %(levelname)-8s %(message)s"
>>>+??? )
>>>+
>>>+??? f = Forwarder(server=(args.server, args.port))
>>>+
>>>+??? try:
>>>+??????? while True:
>>>+??????????? f.c2s()
>>>+??????????? f.s2c()
>>>+??????????? f.log_stats_interval()
>>>+??? finally:
>>>+??????? f.log_stats()
>>>+
>>>+
>>>+if __name__ == "__main__":
>>>+??? main()
>>>
>>
>
>

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2024-05-28 05:22:14

by Michael Grzeschik

[permalink] [raw]
Subject: Re: [PATCH v4 2/3] net/9p/usbg: Add new usb gadget function transport

On Fri, May 10, 2024 at 04:11:27PM +0200, Andrzej Pietrasiewicz wrote:
>Hi,
>
>W dniu 10.05.2024 o?12:11, Michael Grzeschik pisze:
>>On Fri, May 10, 2024 at 11:25:47AM +0200, Andrzej Pietrasiewicz wrote:
>>>Hi Michael,
>>>
>>>W dniu 30.04.2024 o?01:33, Michael Grzeschik pisze:
>>>>Add the new gadget function for 9pfs transport. This function is
>>>>defining an simple 9pfs transport interface that consists of one in and
>>>>one out endpoint. The endpoints transmit and receive the 9pfs protocol
>>>>payload when mounting a 9p filesystem over usb.
>>>>
>>>>Signed-off-by: Michael Grzeschik <[email protected]>
>>>>
>>>>---
>>>>v3 -> v4:
>>>>? - implemented conn_cancel
>>>
>>>I tried this scenario:
>>>
>>>1) run all the components and have 9pfs up and running
>>>2) stop the forwarder
>>>3) umount -f at the gadget side - this indeed succeeds now in v4
>>>4) start the forwarder again
>>>5) mount at the gadget side - this hangs.
>>>
>>>Did this scenario work for you?
>>
>>I actually tested this exact scenario. So this is
>>suprising. I will try this again just to be sure
>>that I did send the latest version.
>>
>>My latest testsetup included the dummy_hcd. Did you test on real hardware?
>
>Yes, I did.

I found out that the issue lies in the current disable/enable endpoint
mechanism the layer was using to stop and enable the endpoint every
time the fs was unmounted or mounted. I changed this to only disable
the endpoint on unbind and enable it on set alt callback.

This should work fine now with v5.

https://lore.kernel.org/all/[email protected]/

Regards,
Michael

>>>>? - moved from mount_tag to device name like ffs does
>>>>? - renamed function_list to usb9pfs_instance
>>>>? - renamed usbg_function_list to usb9pfs_instance_list
>>>>? - renamed rx/tx_fill to queue_rx/tx
>>>>? - added use of retvals
>>>>? - added locking comment over usb9pfs_transmit
>>>>? - using if_else instead of two pathed switch calls
>>>>? - fixed return values of completion handler
>>>>? - using void pointer as parameter in rx_header
>>>>? - added a missed req_put in rx_header
>>>>? - removed extra disable function but call disable_ep directly
>>>>? - repaired several return values
>>>>? - remove the suspicious disable / enable path in usbg_create
>>>>v2 -> v3: -
>>>>v1 -> v2:
>>>>? - move the driver to net/9p/trans_usbg.c
>>>>? - fixed the commit title
>>>>? - fix %zu usage in p9_debug for size_t type
>>>>? - define functions static that are only used localy
>>>>? - return 0 in alloc_requests
>>>>? - use id_alloc_max instead of ida_simple_get
>>>>? - call ida_free in usb9pfs_free_func
>>>>? - call kfree for usb9pfs->tag and usb9pfs in usb9pfs_free_func
>>>>? - add MODULE_ALIAS_9P to load this module automatic when mounting
>>>>? - improved the documentation
>>>>? - added depends on USB_GADGET in Kconfig
>>>>---
>>>>?Documentation/filesystems/9p.rst |? 17 +-
>>>>?net/9p/Kconfig?????????????????? |?? 6 +
>>>>?net/9p/Makefile????????????????? |?? 4 +
>>>>?net/9p/trans_usbg.c????????????? | 983 +++++++++++++++++++++++++++++++++++++++
>>>>?4 files changed, 1009 insertions(+), 1 deletion(-)
>>>>
>>>>diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst
>>>>index 1e0e0bb6fdf91..10cf79dc287f8 100644
>>>>--- a/Documentation/filesystems/9p.rst
>>>>+++ b/Documentation/filesystems/9p.rst
>>>>@@ -48,11 +48,25 @@ For server running on QEMU host with virtio transport::
>>>>???? mount -t 9p -o trans=virtio <mount_tag> /mnt/9
>>>>-where mount_tag is the tag associated by the server to each of the exported
>>>>+where mount_tag is the tag generated by the server to each of the exported
>>>>?mount points. Each 9P export is seen by the client as a virtio device with an
>>>>?associated "mount_tag" property. Available mount tags can be
>>>>?seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
>>>>+USBG Usage
>>>>+==========
>>>>+
>>>>+To mount a 9p FS on a USB Host accessible via the gadget at runtime::
>>>>+
>>>>+??? mount -t 9p -o trans=usbg,aname=/path/to/fs <device> /mnt/9
>>>>+
>>>>+To mount a 9p FS on a USB Host accessible via the gadget as root filesystem::
>>>>+
>>>>+??? root=<device> rootfstype=9p rootflags=trans=usbg,cache=loose,uname=root,access=0,dfltuid=0,dfltgid=0,aname=/path/to/rootfs
>>>>+
>>>>+where <device> is the tag associated by the usb gadget transport.
>>>>+It is defined by the configfs instance name.
>>>>+
>>>>?Options
>>>>?=======
>>>>@@ -68,6 +82,7 @@ Options
>>>>???????????? virtio????? connect to the next virtio channel available
>>>>?????????????????? (from QEMU with trans_virtio module)
>>>>???????????? rdma????? connect to a specified RDMA channel
>>>>+??????????? usbg????? connect to a specified usb gadget channel
>>>>???????????? ========? ============================================
>>>>?? uname=name??? user name to attempt mount as on the remote server.? The
>>>>diff --git a/net/9p/Kconfig b/net/9p/Kconfig
>>>>index 00ebce9e5a657..c3d357eb8bb37 100644
>>>>--- a/net/9p/Kconfig
>>>>+++ b/net/9p/Kconfig
>>>>@@ -39,6 +39,12 @@ config NET_9P_XEN
>>>>?????? This builds support for a transport for 9pfs between
>>>>?????? two Xen domains.
>>>>+config NET_9P_USBG
>>>>+??? bool "9P USB Gadget Transport"
>>>>+??? depends on USB_GADGET
>>>>+??? help
>>>>+????? This builds support for a transport for 9pfs over
>>>>+????? usb gadget.
>>>>?config NET_9P_RDMA
>>>>???? depends on INET && INFINIBAND && INFINIBAND_ADDR_TRANS
>>>>diff --git a/net/9p/Makefile b/net/9p/Makefile
>>>>index 1df9b344c30bd..22794a451c3f7 100644
>>>>--- a/net/9p/Makefile
>>>>+++ b/net/9p/Makefile
>>>>@@ -4,6 +4,7 @@ obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
>>>>?obj-$(CONFIG_NET_9P_XEN) += 9pnet_xen.o
>>>>?obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o
>>>>?obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
>>>>+obj-$(CONFIG_NET_9P_USBG) += 9pnet_usbg.o
>>>>?9pnet-objs := \
>>>>???? mod.o \
>>>>@@ -23,3 +24,6 @@ obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o
>>>>?9pnet_rdma-objs := \
>>>>???? trans_rdma.o \
>>>>+
>>>>+9pnet_usbg-objs := \
>>>>+??? trans_usbg.o \
>>>>diff --git a/net/9p/trans_usbg.c b/net/9p/trans_usbg.c
>>>>new file mode 100644
>>>>index 0000000000000..bc440033cbe68
>>>>--- /dev/null
>>>>+++ b/net/9p/trans_usbg.c
>>>>@@ -0,0 +1,983 @@
>>>>+// SPDX-License-Identifier: GPL-2.0+
>>>>+/*
>>>>+ * trans_usbg.c - USB peripheral usb9pfs configuration driver and transport.
>>>>+ *
>>>>+ * Copyright (C) 2024 Michael Grzeschik <[email protected]>
>>>>+ */
>>>>+
>>>>+/* Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs
>>>>+ * transport to mount host exported filesystem via usb gadget.
>>>>+ */
>>>>+
>>>>+/*???? +--------------------------+??? |??? +--------------------------+
>>>>+ *???? |? 9PFS mounting client??? |??? |??? |? 9PFS exporting server?? |
>>>>+ *? SW |????????????????????????? |??? |??? |????????????????????????? |
>>>>+ *???? |?? (this:trans_usbg)????? |??? |??? |(e.g. diod or nfs-ganesha)|
>>>>+ *???? +-------------^------------+??? |??? +-------------^------------+
>>>>+ *?????????????????? |???????????????? |????????????????? |
>>>>+ * ------------------|------------------------------------|-------------
>>>>+ *?????????????????? |???????????????? |????????????????? |
>>>>+ *???? +-------------v------------+??? |??? +-------------v------------+
>>>>+ *???? |????????????????????????? |??? |??? |????????????????????????? |
>>>>+ *? HW |?? USB Device Controller? <--------->?? USB Host Controller??? |
>>>>+ *???? |????????????????????????? |??? |??? |????????????????????????? |
>>>>+ *???? +--------------------------+??? |??? +--------------------------+
>>>>+ */
>>>>+
>>>>+#include <linux/slab.h>
>>>>+#include <linux/kernel.h>
>>>>+#include <linux/device.h>
>>>>+#include <linux/module.h>
>>>>+#include <linux/err.h>
>>>>+#include <linux/usb/composite.h>
>>>>+#include <linux/usb/u_f.h>
>>>>+
>>>>+#include <net/9p/9p.h>
>>>>+#include <net/9p/client.h>
>>>>+#include <net/9p/transport.h>
>>>>+
>>>>+#define DEFAULT_BUFLEN??????? 16384
>>>>+
>>>>+struct f_usb9pfs {
>>>>+??? struct p9_client *client;
>>>>+
>>>>+??? struct p9_req_t *p9_tx_req;
>>>>+
>>>>+??? struct list_head tx_req_list;
>>>>+
>>>>+??? /* 9p request lock for en/dequeue */
>>>>+??? spinlock_t lock;
>>>>+??? /* usb request lock for en/dequeue */
>>>>+??? spinlock_t req_lock;
>>>>+
>>>>+??? struct usb_request *in_req;
>>>>+??? struct usb_request *out_req;
>>>>+
>>>>+??? struct usb_ep *in_ep;
>>>>+??? struct usb_ep *out_ep;
>>>>+
>>>>+??? unsigned int buflen;
>>>>+
>>>>+??? struct usb_function function;
>>>>+};
>>>>+
>>>>+static inline struct f_usb9pfs *func_to_usb9pfs(struct usb_function *f)
>>>>+{
>>>>+??? return container_of(f, struct f_usb9pfs, function);
>>>>+}
>>>>+
>>>>+struct f_usb9pfs_opts {
>>>>+??? struct usb_function_instance func_inst;
>>>>+??? unsigned int buflen;
>>>>+
>>>>+??? struct f_usb9pfs_dev *dev;
>>>>+
>>>>+??? /* Read/write access to configfs attributes is handled by configfs.
>>>>+???? *
>>>>+???? * This is to protect the data from concurrent access by read/write
>>>>+???? * and create symlink/remove symlink.
>>>>+???? */
>>>>+??? struct mutex lock;
>>>>+??? int refcnt;
>>>>+};
>>>>+
>>>>+struct f_usb9pfs_dev {
>>>>+??? struct f_usb9pfs *usb9pfs;
>>>>+??? struct f_usb9pfs_opts *opts;
>>>>+??? char tag[41];
>>>>+??? bool inuse;
>>>>+
>>>>+??? struct list_head usb9pfs_instance;
>>>>+};
>>>>+
>>>>+static DEFINE_MUTEX(usb9pfs_lock);
>>>>+static struct list_head usbg_instance_list;
>>>>+
>>>>+static int usb9pfs_queue_tx(struct f_usb9pfs *usb9pfs, struct usb_request *req,
>>>>+??????????????? gfp_t gfp_flags)
>>>>+{
>>>>+??? struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>>>+??? int ret = -ENOMEM;
>>>>+
>>>>+??? if (!(usb9pfs->p9_tx_req->tc.size % usb9pfs->in_ep->maxpacket))
>>>>+??????? req->zero = 1;
>>>>+
>>>>+??? req->buf = usb9pfs->p9_tx_req->tc.sdata;
>>>>+??? req->length = usb9pfs->p9_tx_req->tc.size;
>>>>+
>>>>+??? dev_dbg(&cdev->gadget->dev, "%s usb9pfs send --> %d/%d, zero: %d\n",
>>>>+??????? usb9pfs->in_ep->name, req->actual, req->length, req->zero);
>>>>+
>>>>+??? ret = usb_ep_queue(usb9pfs->in_ep, req, gfp_flags);
>>>>+
>>>>+??? dev_dbg(&cdev->gadget->dev, "tx submit --> %d\n", ret);
>>>>+
>>>>+??? return ret;
>>>>+}
>>>>+
>>>>+static int usb9pfs_queue_rx(struct f_usb9pfs *usb9pfs, struct usb_request *req,
>>>>+??????????????? gfp_t gfp_flags)
>>>>+{
>>>>+??? struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>>>+??? int ret = -ENOMEM;
>>>>+
>>>>+??? ret = usb_ep_queue(usb9pfs->out_ep, req, gfp_flags);
>>>>+
>>>>+??? dev_dbg(&cdev->gadget->dev, "rx submit --> %d\n", ret);
>>>>+
>>>>+??? return ret;
>>>>+}
>>>>+
>>>>+/* This needs to be called with usb9pfs->req_lock held */
>>>>+static int usb9pfs_transmit(struct f_usb9pfs *usb9pfs)
>>>>+{
>>>>+??? struct p9_req_t *p9_req = NULL;
>>>>+??? unsigned long flags;
>>>>+??? int ret = 0;
>>>>+
>>>>+??? spin_lock_irqsave(&usb9pfs->lock, flags);
>>>>+
>>>>+??? if (usb9pfs->p9_tx_req) {
>>>>+??????? spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>>>+??????? return -EBUSY;
>>>>+??? }
>>>>+
>>>>+??? p9_req = list_first_entry_or_null(&usb9pfs->tx_req_list,
>>>>+????????????????????? struct p9_req_t, req_list);
>>>>+??? if (!p9_req) {
>>>>+??????? spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>>>+??????? return -ENOENT;
>>>>+??? }
>>>>+
>>>>+??? list_del(&p9_req->req_list);
>>>>+
>>>>+??? usb9pfs->p9_tx_req = p9_req;
>>>>+
>>>>+??? p9_req_get(usb9pfs->p9_tx_req);
>>>>+
>>>>+??? ret = usb9pfs_queue_tx(usb9pfs, usb9pfs->in_req, GFP_ATOMIC);
>>>>+
>>>>+??? spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>>>+
>>>>+??? return ret;
>>>>+}
>>>>+
>>>>+static void usb9pfs_tx_complete(struct usb_ep *ep, struct usb_request *req)
>>>>+{
>>>>+??? struct f_usb9pfs *usb9pfs = ep->driver_data;
>>>>+??? struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>>>+??? int ret = 0;
>>>>+
>>>>+??? if (req->status) {
>>>>+??????? dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
>>>>+??????????? ep->name, req->status, req->actual, req->length);
>>>>+??????? goto free_req;
>>>>+??? }
>>>>+
>>>>+??? /* reset zero packages */
>>>>+??? req->zero = 0;
>>>>+
>>>>+??? dev_dbg(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
>>>>+??????? ep->name, req->status, req->actual, req->length);
>>>>+
>>>>+??? spin_lock(&usb9pfs->req_lock);
>>>>+
>>>>+??? WRITE_ONCE(usb9pfs->p9_tx_req->status, REQ_STATUS_SENT);
>>>>+
>>>>+??? p9_req_put(usb9pfs->client, usb9pfs->p9_tx_req);
>>>>+
>>>>+??? ret = usb9pfs_queue_rx(usb9pfs, usb9pfs->out_req, GFP_ATOMIC);
>>>>+??? if (ret) {
>>>>+??????? spin_unlock(&usb9pfs->req_lock);
>>>>+??????? goto free_req;
>>>>+??? }
>>>>+
>>>>+??? spin_unlock(&usb9pfs->req_lock);
>>>>+
>>>>+??? return;
>>>>+
>>>>+free_req:
>>>>+??? usb_ep_free_request(ep == usb9pfs->in_ep ?
>>>>+??????????????? usb9pfs->out_ep : usb9pfs->in_ep,
>>>>+??????????????? req->context);
>>>>+??? free_ep_req(ep, req);
>>>>+}
>>>>+
>>>>+static struct p9_req_t *usb9pfs_rx_header(struct f_usb9pfs *usb9pfs, void *buf)
>>>>+{
>>>>+??? struct p9_req_t *p9_rx_req;
>>>>+??? struct p9_fcall??? rc;
>>>>+??? int ret;
>>>>+
>>>>+??? /* start by reading header */
>>>>+??? rc.sdata = buf;
>>>>+??? rc.offset = 0;
>>>>+??? rc.capacity = P9_HDRSZ;
>>>>+??? rc.size = P9_HDRSZ;
>>>>+
>>>>+??? p9_debug(P9_DEBUG_TRANS, "mux %p got %zu bytes\n", usb9pfs,
>>>>+???????? rc.capacity - rc.offset);
>>>>+
>>>>+??? ret = p9_parse_header(&rc, &rc.size, NULL, NULL, 0);
>>>>+??? if (ret) {
>>>>+??????? p9_debug(P9_DEBUG_ERROR,
>>>>+???????????? "error parsing header: %d\n", ret);
>>>>+??????? return NULL;
>>>>+??? }
>>>>+
>>>>+??? p9_debug(P9_DEBUG_TRANS,
>>>>+???????? "mux %p pkt: size: %d bytes tag: %d\n",
>>>>+???????? usb9pfs, rc.size, rc.tag);
>>>>+
>>>>+??? p9_rx_req = p9_tag_lookup(usb9pfs->client, rc.tag);
>>>>+??? if (!p9_rx_req || p9_rx_req->status != REQ_STATUS_SENT) {
>>>>+??????? p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", rc.tag);
>>>>+??????? return NULL;
>>>>+??? }
>>>>+
>>>>+??? if (rc.size > p9_rx_req->rc.capacity) {
>>>>+??????? p9_debug(P9_DEBUG_ERROR,
>>>>+???????????? "requested packet size too big: %d for tag %d with
>>>>capacity %zd\n",
>>>>+???????????? rc.size, rc.tag, p9_rx_req->rc.capacity);
>>>>+??????? p9_req_put(usb9pfs->client, p9_rx_req);
>>>>+??????? return NULL;
>>>>+??? }
>>>>+
>>>>+??? if (!p9_rx_req->rc.sdata) {
>>>>+??????? p9_debug(P9_DEBUG_ERROR,
>>>>+???????????? "No recv fcall for tag %d (req %p), disconnecting!\n",
>>>>+???????????? rc.tag, p9_rx_req);
>>>>+??????? p9_req_put(usb9pfs->client, p9_rx_req);
>>>>+??????? return NULL;
>>>>+??? }
>>>>+
>>>>+??? return p9_rx_req;
>>>>+}
>>>>+
>>>>+static void usb9pfs_rx_complete(struct usb_ep *ep, struct usb_request *req)
>>>>+{
>>>>+??? struct f_usb9pfs *usb9pfs = ep->driver_data;
>>>>+??? struct usb_composite_dev *cdev = usb9pfs->function.config->cdev;
>>>>+??? struct p9_req_t *p9_rx_req;
>>>>+??? unsigned long flags;
>>>>+??? int ret = 0;
>>>>+
>>>>+??? if (req->status) {
>>>>+??????? dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n",
>>>>+??????????? ep->name, req->status, req->actual, req->length);
>>>>+??????? goto free_req;
>>>>+??? }
>>>>+
>>>>+??? spin_lock_irqsave(&usb9pfs->req_lock, flags);
>>>>+
>>>>+??? p9_rx_req = usb9pfs_rx_header(usb9pfs, req->buf);
>>>>+??? if (!p9_rx_req) {
>>>>+??????? spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>>>+??????? goto free_req;
>>>>+??? }
>>>>+
>>>>+??? memcpy(p9_rx_req->rc.sdata, req->buf, req->actual);
>>>>+
>>>>+??? p9_rx_req->rc.size = req->actual;
>>>>+
>>>>+??? p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_RCVD);
>>>>+??? p9_req_put(usb9pfs->client, p9_rx_req);
>>>>+
>>>>+??? usb9pfs->p9_tx_req = NULL;
>>>>+
>>>>+??? ret = usb9pfs_transmit(usb9pfs);
>>>>+??? if (ret) {
>>>>+??????? spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>>>+??????? return;
>>>>+??? }
>>>>+
>>>>+??? spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>>>+
>>>>+??? return;
>>>>+
>>>>+free_req:
>>>>+??? usb_ep_free_request(ep == usb9pfs->in_ep ?
>>>>+??????????????? usb9pfs->out_ep : usb9pfs->in_ep,
>>>>+??????????????? req->context);
>>>>+??? free_ep_req(ep, req);
>>>>+
>>>>+??? p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_ERROR);
>>>>+}
>>>>+
>>>>+static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
>>>>+{
>>>>+??? int value;
>>>>+
>>>>+??? value = usb_ep_disable(ep);
>>>>+??? if (value < 0)
>>>>+??????? dev_info(&cdev->gadget->dev,
>>>>+???????????? "disable %s --> %d\n", ep->name, value);
>>>>+}
>>>>+
>>>>+static void disable_usb9pfs(struct f_usb9pfs *usb9pfs)
>>>>+{
>>>>+??? struct usb_composite_dev *cdev =
>>>>+??????? usb9pfs->function.config->cdev;
>>>>+
>>>>+??? disable_ep(cdev, usb9pfs->in_ep);
>>>>+??? disable_ep(cdev, usb9pfs->out_ep);
>>>>+??? dev_dbg(&cdev->gadget->dev, "%s disabled\n",
>>>>+??????? usb9pfs->function.name);
>>>>+}
>>>>+
>>>>+static int alloc_requests(struct usb_composite_dev *cdev,
>>>>+????????????? struct f_usb9pfs *usb9pfs)
>>>>+{
>>>>+??? int ret = 0;
>>>>+
>>>>+??? usb9pfs->in_req = usb_ep_alloc_request(usb9pfs->in_ep, GFP_ATOMIC);
>>>>+??? if (!usb9pfs->in_req) {
>>>>+??????? ret = -ENOENT;
>>>>+??????? goto fail;
>>>>+??? }
>>>>+
>>>>+??? usb9pfs->out_req = alloc_ep_req(usb9pfs->out_ep, usb9pfs->buflen);
>>>>+??? if (!usb9pfs->out_req) {
>>>>+??????? ret = -ENOENT;
>>>>+??????? goto fail_in;
>>>>+??? }
>>>>+
>>>>+??? usb9pfs->in_req->complete = usb9pfs_tx_complete;
>>>>+??? usb9pfs->out_req->complete = usb9pfs_rx_complete;
>>>>+
>>>>+??? /* length will be set in complete routine */
>>>>+??? usb9pfs->in_req->context = usb9pfs;
>>>>+??? usb9pfs->out_req->context = usb9pfs;
>>>>+
>>>>+??? return ret;
>>>>+
>>>>+fail_in:
>>>>+??? usb_ep_free_request(usb9pfs->in_ep, usb9pfs->in_req);
>>>>+fail:
>>>>+??? return ret;
>>>>+}
>>>>+
>>>>+static int enable_endpoint(struct usb_composite_dev *cdev,
>>>>+?????????????? struct f_usb9pfs *usb9pfs, struct usb_ep *ep)
>>>>+{
>>>>+??? int ret;
>>>>+
>>>>+??? ret = config_ep_by_speed(cdev->gadget, &usb9pfs->function, ep);
>>>>+??? if (ret)
>>>>+??????? return ret;
>>>>+
>>>>+??? ret = usb_ep_enable(ep);
>>>>+??? if (ret < 0)
>>>>+??????? return ret;
>>>>+
>>>>+??? ep->driver_data = usb9pfs;
>>>>+
>>>>+??? return ret;
>>>>+}
>>>>+
>>>>+static int
>>>>+enable_usb9pfs(struct usb_composite_dev *cdev, struct f_usb9pfs *usb9pfs)
>>>>+{
>>>>+??? int result = 0;
>>>>+
>>>>+??? result = enable_endpoint(cdev, usb9pfs, usb9pfs->in_ep);
>>>>+??? if (result)
>>>>+??????? goto out;
>>>>+
>>>>+??? result = enable_endpoint(cdev, usb9pfs, usb9pfs->out_ep);
>>>>+??? if (result)
>>>>+??????? goto disable_in;
>>>>+
>>>>+??? result = alloc_requests(cdev, usb9pfs);
>>>>+??? if (result)
>>>>+??????? goto disable_out;
>>>>+
>>>>+??? dev_dbg(&cdev->gadget->dev, "%s enabled\n", usb9pfs->function.name);
>>>>+??? return 0;
>>>>+
>>>>+disable_out:
>>>>+??? usb_ep_disable(usb9pfs->out_ep);
>>>>+disable_in:
>>>>+??? usb_ep_disable(usb9pfs->in_ep);
>>>>+out:
>>>>+??? return result;
>>>>+}
>>>>+
>>>>+static int p9_usbg_create(struct p9_client *client, const char
>>>>*devname, char *args)
>>>>+{
>>>>+??? struct usb_composite_dev *cdev;
>>>>+??? struct f_usb9pfs_dev *dev;
>>>>+??? struct f_usb9pfs_dev *tmp;
>>>>+??? struct f_usb9pfs *usb9pfs;
>>>>+??? struct usb_function *f;
>>>>+??? int ret = -ENOENT;
>>>>+??? int found = 0;
>>>>+
>>>>+??? if (!devname)
>>>>+??????? return -EINVAL;
>>>>+
>>>>+??? mutex_lock(&usb9pfs_lock);
>>>>+??? list_for_each_entry_safe(dev, tmp, &usbg_instance_list, usb9pfs_instance) {
>>>>+??????? if (!strncmp(devname, dev->tag, strlen(devname))) {
>>>>+??????????? if (!dev->inuse) {
>>>>+??????????????? dev->inuse = true;
>>>>+??????????????? found = 1;
>>>>+??????????????? break;
>>>>+??????????? }
>>>>+??????????? ret = -EBUSY;
>>>>+??????????? break;
>>>>+??????? }
>>>>+??? }
>>>>+??? mutex_unlock(&usb9pfs_lock);
>>>>+
>>>>+??? if (!found) {
>>>>+??????? pr_err("no channels available for device %s\n", devname);
>>>>+??????? return ret;
>>>>+??? }
>>>>+
>>>>+??? usb9pfs = dev->usb9pfs;
>>>>+??? if (!usb9pfs)
>>>>+??????? return -EINVAL;
>>>>+
>>>>+??? INIT_LIST_HEAD(&usb9pfs->tx_req_list);
>>>>+
>>>>+??? spin_lock_init(&usb9pfs->lock);
>>>>+??? spin_lock_init(&usb9pfs->req_lock);
>>>>+
>>>>+??? f = &usb9pfs->function;
>>>>+??? cdev = f->config->cdev;
>>>>+
>>>>+??? client->trans = (void *)usb9pfs;
>>>>+??? client->status = Connected;
>>>>+??? usb9pfs->client = client;
>>>>+
>>>>+??? client->trans_mod->maxsize = usb9pfs->buflen;
>>>>+
>>>>+??? return enable_usb9pfs(cdev, usb9pfs);
>>>>+}
>>>>+
>>>>+static void p9_usbg_close(struct p9_client *client)
>>>>+{
>>>>+??? struct f_usb9pfs *usb9pfs;
>>>>+??? struct f_usb9pfs_dev *dev;
>>>>+??? struct p9_req_t *req;
>>>>+??? struct f_usb9pfs_opts *opts;
>>>>+
>>>>+??? if (!client)
>>>>+??????? return;
>>>>+
>>>>+??? usb9pfs = client->trans;
>>>>+??? if (!usb9pfs)
>>>>+??????? return;
>>>>+
>>>>+??? client->status = Disconnected;
>>>>+
>>>>+??? spin_lock(&usb9pfs->req_lock);
>>>>+
>>>>+??? req = usb9pfs->p9_tx_req;
>>>>+??? if (req) {
>>>>+??????? if (!req->t_err)
>>>>+??????????? req->t_err = -ECONNRESET;
>>>>+??????? p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR);
>>>>+??? }
>>>>+
>>>>+??? spin_unlock(&usb9pfs->req_lock);
>>>>+
>>>>+??? disable_usb9pfs(usb9pfs);
>>>>+
>>>>+??? opts = container_of(usb9pfs->function.fi,
>>>>+??????????????? struct f_usb9pfs_opts, func_inst);
>>>>+
>>>>+??? dev = opts->dev;
>>>>+
>>>>+??? mutex_lock(&usb9pfs_lock);
>>>>+??? dev->inuse = false;
>>>>+??? mutex_unlock(&usb9pfs_lock);
>>>>+}
>>>>+
>>>>+static int p9_usbg_request(struct p9_client *client, struct p9_req_t *p9_req)
>>>>+{
>>>>+??? struct f_usb9pfs *usb9pfs = client->trans;
>>>>+??? unsigned long flags;
>>>>+
>>>>+??? if (client->status != Connected)
>>>>+??????? return -EBUSY;
>>>>+
>>>>+??? spin_lock_irqsave(&usb9pfs->lock, flags);
>>>>+??? list_add_tail(&p9_req->req_list, &usb9pfs->tx_req_list);
>>>>+??? spin_unlock_irqrestore(&usb9pfs->lock, flags);
>>>>+
>>>>+??? spin_lock_irqsave(&usb9pfs->req_lock, flags);
>>>>+??? usb9pfs_transmit(usb9pfs);
>>>>+??? spin_unlock_irqrestore(&usb9pfs->req_lock, flags);
>>>>+
>>>>+??? return 0;
>>>>+}
>>>>+
>>>>+static int p9_usbg_cancel(struct p9_client *client, struct p9_req_t *req)
>>>>+{
>>>>+??? struct f_usb9pfs *usb9pfs = client->trans;
>>>>+??? int ret = 1;
>>>>+
>>>>+??? p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
>>>>+
>>>>+??? spin_lock(&usb9pfs->req_lock);
>>>>+
>>>>+??? if (req->status == REQ_STATUS_UNSENT) {
>>>>+??????? list_del(&req->req_list);
>>>>+??????? WRITE_ONCE(req->status, REQ_STATUS_FLSHD);
>>>>+??????? p9_req_put(client, req);
>>>>+??????? ret = 0;
>>>>+??? }
>>>>+??? spin_unlock(&usb9pfs->req_lock);
>>>>+
>>>>+??? return ret;
>>>>+}
>>>>+
>>>>+static struct p9_trans_module p9_usbg_trans = {
>>>>+??? .name = "usbg",
>>>>+??? .create = p9_usbg_create,
>>>>+??? .close = p9_usbg_close,
>>>>+??? .request = p9_usbg_request,
>>>>+??? .cancel = p9_usbg_cancel,
>>>>+??? .owner = THIS_MODULE,
>>>>+};
>>>>+
>>>>+/*-------------------------------------------------------------------------*/
>>>>+
>>>>+#define USB_PROTOCOL_9PFS??? 0x09
>>>>+
>>>>+static struct usb_interface_descriptor usb9pfs_intf = {
>>>>+??? .bLength =??????? sizeof(usb9pfs_intf),
>>>>+??? .bDescriptorType =??? USB_DT_INTERFACE,
>>>>+
>>>>+??? .bNumEndpoints =??? 2,
>>>>+??? .bInterfaceClass =??? USB_CLASS_VENDOR_SPEC,
>>>>+??? .bInterfaceSubClass =??? USB_SUBCLASS_VENDOR_SPEC,
>>>>+??? .bInterfaceProtocol =?? USB_PROTOCOL_9PFS,
>>>>+
>>>>+??? /* .iInterface = DYNAMIC */
>>>>+};
>>>>+
>>>>+/* full speed support: */
>>>>+
>>>>+static struct usb_endpoint_descriptor fs_usb9pfs_source_desc = {
>>>>+??? .bLength =??????? USB_DT_ENDPOINT_SIZE,
>>>>+??? .bDescriptorType =??? USB_DT_ENDPOINT,
>>>>+
>>>>+??? .bEndpointAddress =??? USB_DIR_IN,
>>>>+??? .bmAttributes =??????? USB_ENDPOINT_XFER_BULK,
>>>>+};
>>>>+
>>>>+static struct usb_endpoint_descriptor fs_usb9pfs_sink_desc = {
>>>>+??? .bLength =??????? USB_DT_ENDPOINT_SIZE,
>>>>+??? .bDescriptorType =??? USB_DT_ENDPOINT,
>>>>+
>>>>+??? .bEndpointAddress =??? USB_DIR_OUT,
>>>>+??? .bmAttributes =??????? USB_ENDPOINT_XFER_BULK,
>>>>+};
>>>>+
>>>>+static struct usb_descriptor_header *fs_usb9pfs_descs[] = {
>>>>+??? (struct usb_descriptor_header *)&usb9pfs_intf,
>>>>+??? (struct usb_descriptor_header *)&fs_usb9pfs_sink_desc,
>>>>+??? (struct usb_descriptor_header *)&fs_usb9pfs_source_desc,
>>>>+??? NULL,
>>>>+};
>>>>+
>>>>+/* high speed support: */
>>>>+
>>>>+static struct usb_endpoint_descriptor hs_usb9pfs_source_desc = {
>>>>+??? .bLength =??????? USB_DT_ENDPOINT_SIZE,
>>>>+??? .bDescriptorType =??? USB_DT_ENDPOINT,
>>>>+
>>>>+??? .bmAttributes =??????? USB_ENDPOINT_XFER_BULK,
>>>>+??? .wMaxPacketSize =??? cpu_to_le16(512),
>>>>+};
>>>>+
>>>>+static struct usb_endpoint_descriptor hs_usb9pfs_sink_desc = {
>>>>+??? .bLength =??????? USB_DT_ENDPOINT_SIZE,
>>>>+??? .bDescriptorType =??? USB_DT_ENDPOINT,
>>>>+
>>>>+??? .bmAttributes =??????? USB_ENDPOINT_XFER_BULK,
>>>>+??? .wMaxPacketSize =??? cpu_to_le16(512),
>>>>+};
>>>>+
>>>>+static struct usb_descriptor_header *hs_usb9pfs_descs[] = {
>>>>+??? (struct usb_descriptor_header *)&usb9pfs_intf,
>>>>+??? (struct usb_descriptor_header *)&hs_usb9pfs_source_desc,
>>>>+??? (struct usb_descriptor_header *)&hs_usb9pfs_sink_desc,
>>>>+??? NULL,
>>>>+};
>>>>+
>>>>+/* super speed support: */
>>>>+
>>>>+static struct usb_endpoint_descriptor ss_usb9pfs_source_desc = {
>>>>+??? .bLength =??????? USB_DT_ENDPOINT_SIZE,
>>>>+??? .bDescriptorType =??? USB_DT_ENDPOINT,
>>>>+
>>>>+??? .bmAttributes =??????? USB_ENDPOINT_XFER_BULK,
>>>>+??? .wMaxPacketSize =??? cpu_to_le16(1024),
>>>>+};
>>>>+
>>>>+static struct usb_ss_ep_comp_descriptor ss_usb9pfs_source_comp_desc = {
>>>>+??? .bLength =??????? USB_DT_SS_EP_COMP_SIZE,
>>>>+??? .bDescriptorType =??? USB_DT_SS_ENDPOINT_COMP,
>>>>+??? .bMaxBurst =??????? 0,
>>>>+??? .bmAttributes =??????? 0,
>>>>+??? .wBytesPerInterval =??? 0,
>>>>+};
>>>>+
>>>>+static struct usb_endpoint_descriptor ss_usb9pfs_sink_desc = {
>>>>+??? .bLength =??????? USB_DT_ENDPOINT_SIZE,
>>>>+??? .bDescriptorType =??? USB_DT_ENDPOINT,
>>>>+
>>>>+??? .bmAttributes =??????? USB_ENDPOINT_XFER_BULK,
>>>>+??? .wMaxPacketSize =??? cpu_to_le16(1024),
>>>>+};
>>>>+
>>>>+static struct usb_ss_ep_comp_descriptor ss_usb9pfs_sink_comp_desc = {
>>>>+??? .bLength =??????? USB_DT_SS_EP_COMP_SIZE,
>>>>+??? .bDescriptorType =??? USB_DT_SS_ENDPOINT_COMP,
>>>>+??? .bMaxBurst =??????? 0,
>>>>+??? .bmAttributes =??????? 0,
>>>>+??? .wBytesPerInterval =??? 0,
>>>>+};
>>>>+
>>>>+static struct usb_descriptor_header *ss_usb9pfs_descs[] = {
>>>>+??? (struct usb_descriptor_header *)&usb9pfs_intf,
>>>>+??? (struct usb_descriptor_header *)&ss_usb9pfs_source_desc,
>>>>+??? (struct usb_descriptor_header *)&ss_usb9pfs_source_comp_desc,
>>>>+??? (struct usb_descriptor_header *)&ss_usb9pfs_sink_desc,
>>>>+??? (struct usb_descriptor_header *)&ss_usb9pfs_sink_comp_desc,
>>>>+??? NULL,
>>>>+};
>>>>+
>>>>+/* function-specific strings: */
>>>>+static struct usb_string strings_usb9pfs[] = {
>>>>+??? [0].s = "usb9pfs input to output",
>>>>+??? {? }??????????? /* end of list */
>>>>+};
>>>>+
>>>>+static struct usb_gadget_strings stringtab_usb9pfs = {
>>>>+??? .language??? = 0x0409,??? /* en-us */
>>>>+??? .strings??? = strings_usb9pfs,
>>>>+};
>>>>+
>>>>+static struct usb_gadget_strings *usb9pfs_strings[] = {
>>>>+??? &stringtab_usb9pfs,
>>>>+??? NULL,
>>>>+};
>>>>+
>>>>+/*-------------------------------------------------------------------------*/
>>>>+
>>>>+static int usb9pfs_func_bind(struct usb_configuration *c,
>>>>+???????????????? struct usb_function *f)
>>>>+{
>>>>+??? struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
>>>>+??? struct f_usb9pfs_opts *opts;
>>>>+??? struct usb_composite_dev *cdev = c->cdev;
>>>>+??? int ret;
>>>>+??? int id;
>>>>+
>>>>+??? /* allocate interface ID(s) */
>>>>+??? id = usb_interface_id(c, f);
>>>>+??? if (id < 0)
>>>>+??????? return id;
>>>>+??? usb9pfs_intf.bInterfaceNumber = id;
>>>>+
>>>>+??? id = usb_string_id(cdev);
>>>>+??? if (id < 0)
>>>>+??????? return id;
>>>>+??? strings_usb9pfs[0].id = id;
>>>>+??? usb9pfs_intf.iInterface = id;
>>>>+
>>>>+??? /* allocate endpoints */
>>>>+??? usb9pfs->in_ep = usb_ep_autoconfig(cdev->gadget,
>>>>+?????????????????????? &fs_usb9pfs_source_desc);
>>>>+??? if (!usb9pfs->in_ep)
>>>>+??????? goto autoconf_fail;
>>>>+
>>>>+??? usb9pfs->out_ep = usb_ep_autoconfig(cdev->gadget,
>>>>+??????????????????????? &fs_usb9pfs_sink_desc);
>>>>+??? if (!usb9pfs->out_ep)
>>>>+??????? goto autoconf_fail;
>>>>+
>>>>+??? /* support high speed hardware */
>>>>+??? hs_usb9pfs_source_desc.bEndpointAddress =
>>>>+??????? fs_usb9pfs_source_desc.bEndpointAddress;
>>>>+??? hs_usb9pfs_sink_desc.bEndpointAddress =
>>>>+??????? fs_usb9pfs_sink_desc.bEndpointAddress;
>>>>+
>>>>+??? /* support super speed hardware */
>>>>+??? ss_usb9pfs_source_desc.bEndpointAddress =
>>>>+??????? fs_usb9pfs_source_desc.bEndpointAddress;
>>>>+??? ss_usb9pfs_sink_desc.bEndpointAddress =
>>>>+??????? fs_usb9pfs_sink_desc.bEndpointAddress;
>>>>+
>>>>+??? ret = usb_assign_descriptors(f, fs_usb9pfs_descs, hs_usb9pfs_descs,
>>>>+???????????????????? ss_usb9pfs_descs, ss_usb9pfs_descs);
>>>>+??? if (ret)
>>>>+??????? return ret;
>>>>+
>>>>+??? opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst);
>>>>+??? opts->dev->usb9pfs = usb9pfs;
>>>>+
>>>>+??? dev_dbg(&cdev->gadget->dev, "%s speed %s: IN/%s, OUT/%s\n",
>>>>+??????? (gadget_is_superspeed(c->cdev->gadget) ? "super" :
>>>>+??????? (gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")),
>>>>+??????????? f->name, usb9pfs->in_ep->name, usb9pfs->out_ep->name);
>>>>+
>>>>+??? return 0;
>>>>+
>>>>+autoconf_fail:
>>>>+??? ERROR(cdev, "%s: can't autoconfigure on %s\n",
>>>>+????????? f->name, cdev->gadget->name);
>>>>+??? return -ENODEV;
>>>>+}
>>>>+
>>>>+static void usb9pfs_free_func(struct usb_function *f)
>>>>+{
>>>>+??? struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
>>>>+??? struct f_usb9pfs_opts *opts;
>>>>+
>>>>+??? kfree(usb9pfs);
>>>>+
>>>>+??? opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst);
>>>>+
>>>>+??? mutex_lock(&opts->lock);
>>>>+??? opts->refcnt--;
>>>>+??? mutex_unlock(&opts->lock);
>>>>+
>>>>+??? usb_free_all_descriptors(f);
>>>>+}
>>>>+
>>>>+static int usb9pfs_set_alt(struct usb_function *f,
>>>>+?????????????? unsigned int intf, unsigned int alt)
>>>>+{
>>>>+??? return 0;
>>>>+}
>>>>+
>>>>+static void usb9pfs_disable(struct usb_function *f)
>>>>+{
>>>>+??? struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f);
>>>>+??? struct p9_req_t *req;
>>>>+
>>>>+??? spin_lock(&usb9pfs->req_lock);
>>>>+
>>>>+??? req = usb9pfs->p9_tx_req;
>>>>+
>>>>+??? if (!req->t_err)
>>>>+??????? req->t_err = -ECONNRESET;
>>>>+??? p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR);
>>>>+
>>>>+??? spin_unlock(&usb9pfs->req_lock);
>>>>+}
>>>>+
>>>>+static struct usb_function *usb9pfs_alloc(struct usb_function_instance *fi)
>>>>+{
>>>>+??? struct f_usb9pfs_opts *usb9pfs_opts;
>>>>+??? struct f_usb9pfs *usb9pfs;
>>>>+
>>>>+??? usb9pfs = kzalloc(sizeof(*usb9pfs), GFP_KERNEL);
>>>>+??? if (!usb9pfs)
>>>>+??????? return ERR_PTR(-ENOMEM);
>>>>+
>>>>+??? usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
>>>>+
>>>>+??? mutex_lock(&usb9pfs_opts->lock);
>>>>+??? usb9pfs_opts->refcnt++;
>>>>+??? mutex_unlock(&usb9pfs_opts->lock);
>>>>+
>>>>+??? usb9pfs->buflen = usb9pfs_opts->buflen;
>>>>+
>>>>+??? usb9pfs->function.name = "usb9pfs";
>>>>+??? usb9pfs->function.bind = usb9pfs_func_bind;
>>>>+??? usb9pfs->function.set_alt = usb9pfs_set_alt;
>>>>+??? usb9pfs->function.disable = usb9pfs_disable;
>>>>+??? usb9pfs->function.strings = usb9pfs_strings;
>>>>+
>>>>+??? usb9pfs->function.free_func = usb9pfs_free_func;
>>>>+
>>>>+??? return &usb9pfs->function;
>>>>+}
>>>>+
>>>>+static inline struct f_usb9pfs_opts *to_f_usb9pfs_opts(struct
>>>>config_item *item)
>>>>+{
>>>>+??? return container_of(to_config_group(item), struct f_usb9pfs_opts,
>>>>+??????????????? func_inst.group);
>>>>+}
>>>>+
>>>>+static inline struct f_usb9pfs_opts
>>>>*fi_to_f_usb9pfs_opts(struct usb_function_instance *fi)
>>>>+{
>>>>+??? return container_of(fi, struct f_usb9pfs_opts, func_inst);
>>>>+}
>>>>+
>>>>+static void usb9pfs_attr_release(struct config_item *item)
>>>>+{
>>>>+??? struct f_usb9pfs_opts *usb9pfs_opts = to_f_usb9pfs_opts(item);
>>>>+
>>>>+??? usb_put_function_instance(&usb9pfs_opts->func_inst);
>>>>+}
>>>>+
>>>>+static struct configfs_item_operations usb9pfs_item_ops = {
>>>>+??? .release??????? = usb9pfs_attr_release,
>>>>+};
>>>>+
>>>>+static ssize_t f_usb9pfs_opts_buflen_show(struct config_item *item, char *page)
>>>>+{
>>>>+??? struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
>>>>+??? int result;
>>>>+
>>>>+??? mutex_lock(&opts->lock);
>>>>+??? result = sprintf(page, "%d\n", opts->buflen);
>>>>+??? mutex_unlock(&opts->lock);
>>>>+
>>>>+??? return result;
>>>>+}
>>>>+
>>>>+static ssize_t f_usb9pfs_opts_buflen_store(struct config_item *item,
>>>>+?????????????????????? const char *page, size_t len)
>>>>+{
>>>>+??? struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item);
>>>>+??? int ret;
>>>>+??? u32 num;
>>>>+
>>>>+??? mutex_lock(&opts->lock);
>>>>+??? if (opts->refcnt) {
>>>>+??????? ret = -EBUSY;
>>>>+??????? goto end;
>>>>+??? }
>>>>+
>>>>+??? ret = kstrtou32(page, 0, &num);
>>>>+??? if (ret)
>>>>+??????? goto end;
>>>>+
>>>>+??? opts->buflen = num;
>>>>+??? ret = len;
>>>>+end:
>>>>+??? mutex_unlock(&opts->lock);
>>>>+??? return ret;
>>>>+}
>>>>+
>>>>+CONFIGFS_ATTR(f_usb9pfs_opts_, buflen);
>>>>+
>>>>+static struct configfs_attribute *usb9pfs_attrs[] = {
>>>>+??? &f_usb9pfs_opts_attr_buflen,
>>>>+??? NULL,
>>>>+};
>>>>+
>>>>+static const struct config_item_type usb9pfs_func_type = {
>>>>+??? .ct_item_ops??? = &usb9pfs_item_ops,
>>>>+??? .ct_attrs??? = usb9pfs_attrs,
>>>>+??? .ct_owner??? = THIS_MODULE,
>>>>+};
>>>>+
>>>>+static struct f_usb9pfs_dev *_usb9pfs_do_find_dev(const char *tag)
>>>>+{
>>>>+??? struct f_usb9pfs_dev *usb9pfs_dev;
>>>>+??? struct f_usb9pfs_dev *tmp;
>>>>+
>>>>+??? if (!tag)
>>>>+??????? return NULL;
>>>>+
>>>>+??? list_for_each_entry_safe(usb9pfs_dev, tmp,
>>>>&usbg_instance_list, usb9pfs_instance) {
>>>>+??????? if (strcmp(usb9pfs_dev->tag, tag) == 0)
>>>>+??????????? return usb9pfs_dev;
>>>>+??? }
>>>>+
>>>>+??? return NULL;
>>>>+}
>>>>+
>>>>+static int usb9pfs_tag_instance(struct f_usb9pfs_dev *dev, const char *tag)
>>>>+{
>>>>+??? struct f_usb9pfs_dev *existing;
>>>>+??? int ret = 0;
>>>>+
>>>>+??? mutex_lock(&usb9pfs_lock);
>>>>+??? existing = _usb9pfs_do_find_dev(tag);
>>>>+??? if (!existing)
>>>>+??????? strscpy(dev->tag, tag, ARRAY_SIZE(dev->tag));
>>>>+??? else if (existing != dev)
>>>>+??????? ret = -EBUSY;
>>>>+??? mutex_unlock(&usb9pfs_lock);
>>>>+
>>>>+??? return ret;
>>>>+}
>>>>+
>>>>+static int usb9pfs_set_inst_tag(struct usb_function_instance
>>>>*fi, const char *tag)
>>>>+{
>>>>+??? if (strlen(tag) >= sizeof_field(struct f_usb9pfs_dev, tag))
>>>>+??????? return -ENAMETOOLONG;
>>>>+??? return usb9pfs_tag_instance(fi_to_f_usb9pfs_opts(fi)->dev, tag);
>>>>+}
>>>>+
>>>>+static void usb9pfs_free_instance(struct usb_function_instance *fi)
>>>>+{
>>>>+??? struct f_usb9pfs_opts *usb9pfs_opts;
>>>>+
>>>>+??? usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst);
>>>>+??? kfree(usb9pfs_opts);
>>>>+}
>>>>+
>>>>+static struct usb_function_instance *usb9pfs_alloc_instance(void)
>>>>+{
>>>>+??? struct f_usb9pfs_opts *usb9pfs_opts;
>>>>+??? struct f_usb9pfs_dev *dev;
>>>>+
>>>>+??? usb9pfs_opts = kzalloc(sizeof(*usb9pfs_opts), GFP_KERNEL);
>>>>+??? if (!usb9pfs_opts)
>>>>+??????? return ERR_PTR(-ENOMEM);
>>>>+
>>>>+??? mutex_init(&usb9pfs_opts->lock);
>>>>+
>>>>+??? usb9pfs_opts->func_inst.set_inst_name = usb9pfs_set_inst_tag;
>>>>+??? usb9pfs_opts->func_inst.free_func_inst = usb9pfs_free_instance;
>>>>+
>>>>+??? usb9pfs_opts->buflen = DEFAULT_BUFLEN;
>>>>+
>>>>+??? mutex_lock(&usb9pfs_lock);
>>>>+??? dev = kzalloc(sizeof(*dev), GFP_KERNEL);
>>>>+??? if (IS_ERR(dev)) {
>>>>+??????? mutex_unlock(&usb9pfs_lock);
>>>>+??????? kfree(usb9pfs_opts);
>>>>+??????? return ERR_CAST(dev);
>>>>+??? }
>>>>+??? list_add_tail(&dev->usb9pfs_instance, &usbg_instance_list);
>>>>+??? mutex_unlock(&usb9pfs_lock);
>>>>+
>>>>+??? usb9pfs_opts->dev = dev;
>>>>+??? dev->opts = usb9pfs_opts;
>>>>+
>>>>+??? config_group_init_type_name(&usb9pfs_opts->func_inst.group, "",
>>>>+??????????????????? &usb9pfs_func_type);
>>>>+
>>>>+??? return &usb9pfs_opts->func_inst;
>>>>+}
>>>>+DECLARE_USB_FUNCTION(usb9pfs, usb9pfs_alloc_instance, usb9pfs_alloc);
>>>>+
>>>>+static int __init usb9pfs_modinit(void)
>>>>+{
>>>>+??? int ret;
>>>>+
>>>>+??? INIT_LIST_HEAD(&usbg_instance_list);
>>>>+
>>>>+??? ret = usb_function_register(&usb9pfsusb_func);
>>>>+??? if (!ret)
>>>>+??????? v9fs_register_trans(&p9_usbg_trans);
>>>>+
>>>>+??? return ret;
>>>>+}
>>>>+
>>>>+static void __exit usb9pfs_modexit(void)
>>>>+{
>>>>+??? usb_function_unregister(&usb9pfsusb_func);
>>>>+??? v9fs_unregister_trans(&p9_usbg_trans);
>>>>+}
>>>>+
>>>>+module_init(usb9pfs_modinit);
>>>>+module_exit(usb9pfs_modexit);
>>>>+
>>>>+MODULE_ALIAS_9P("usbg");
>>>>+MODULE_LICENSE("GPL");
>>>>+MODULE_DESCRIPTION("USB gadget 9pfs transport");
>>>>+MODULE_AUTHOR("Michael Grzeschik");
>>>>
>>>
>>>
>>
>
>

--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |


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