2015-12-02 19:36:25

by Jin Qian

[permalink] [raw]
Subject: [PATCH v3 1/8] goldfish: refactor goldfish platform configs

From: Greg Hackmann <[email protected]>

On new virtual devices, the goldfish virtual bus can be replaced with
autoprobing infrastructure like Device Tree. Refactor the goldfish
kernel configs to better accommodate this.

Move the goldfish platform into a menuconfig in the style of the chrome
platform, and separate the goldfish bus into its own config option.

Signed-off-by: Greg Hackmann <[email protected]>
Signed-off-by: Jin Qian <[email protected]>
---
drivers/platform/Kconfig | 3 +--
drivers/platform/goldfish/Kconfig | 18 ++++++++++++++++++
drivers/platform/goldfish/Makefile | 2 +-
3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/Kconfig b/drivers/platform/Kconfig
index 0adccbf..c11db8b 100644
--- a/drivers/platform/Kconfig
+++ b/drivers/platform/Kconfig
@@ -4,8 +4,7 @@ endif
if MIPS
source "drivers/platform/mips/Kconfig"
endif
-if GOLDFISH
+
source "drivers/platform/goldfish/Kconfig"
-endif

source "drivers/platform/chrome/Kconfig"
diff --git a/drivers/platform/goldfish/Kconfig b/drivers/platform/goldfish/Kconfig
index 635ef25..1ae3690 100644
--- a/drivers/platform/goldfish/Kconfig
+++ b/drivers/platform/goldfish/Kconfig
@@ -1,5 +1,23 @@
+menuconfig GOLDFISH
+ bool "Platform support for Goldfish virtual devices"
+ depends on X86_32 || X86_64 || ARM || ARM64
+ ---help---
+ Say Y here to get to see options for the Goldfish virtual platform.
+ This option alone does not add any kernel code.
+
+ Unless you are building for the Android Goldfish emulator say N here.
+
+if GOLDFISH
+
+config GOLDFISH_BUS
+ tristate "Goldfish platform bus"
+ ---help---
+ This is a virtual bus to host Goldfish Android Virtual Devices.
+
config GOLDFISH_PIPE
tristate "Goldfish virtual device for QEMU pipes"
---help---
This is a virtual device to drive the QEMU pipe interface used by
the Goldfish Android Virtual Device.
+
+endif # GOLDFISH
diff --git a/drivers/platform/goldfish/Makefile b/drivers/platform/goldfish/Makefile
index a002239..d348712 100644
--- a/drivers/platform/goldfish/Makefile
+++ b/drivers/platform/goldfish/Makefile
@@ -1,5 +1,5 @@
#
# Makefile for Goldfish platform specific drivers
#
-obj-$(CONFIG_GOLDFISH) += pdev_bus.o
+obj-$(CONFIG_GOLDFISH_BUS) += pdev_bus.o
obj-$(CONFIG_GOLDFISH_PIPE) += goldfish_pipe.o
--
2.6.0.rc2.230.g3dd15c0


2015-12-02 19:42:55

by Jin Qian

[permalink] [raw]
Subject: [PATCH v3 2/8] android_pipe: don't be clever with #define offsets

From: Alex Bennée <[email protected]>

You just make it harder to figure out when commands are being used.

Signed-off-by: Alex Bennée <[email protected]>
Signed-off-by: Jin Qian <[email protected]>
---
drivers/platform/goldfish/goldfish_pipe.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index e7a29e2..0fb3a34 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -90,12 +90,6 @@
#define CMD_WRITE_BUFFER 4 /* send a user buffer to the emulator */
#define CMD_WAKE_ON_WRITE 5 /* tell the emulator to wake us when writing
is possible */
-
-/* The following commands are related to read operations, they must be
- * listed in the same order than the corresponding write ones, since we
- * will use (CMD_READ_BUFFER - CMD_WRITE_BUFFER) as a special offset
- * in goldfish_pipe_read_write() below.
- */
#define CMD_READ_BUFFER 6 /* receive a user buffer from the emulator */
#define CMD_WAKE_ON_READ 7 /* tell the emulator to wake us when reading
* is possible */
@@ -272,8 +266,6 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
unsigned long irq_flags;
struct goldfish_pipe *pipe = filp->private_data;
struct goldfish_pipe_dev *dev = pipe->dev;
- const int cmd_offset = is_write ? 0
- : (CMD_READ_BUFFER - CMD_WRITE_BUFFER);
unsigned long address, address_end;
int ret = 0;

@@ -325,7 +317,8 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,

/* Now, try to transfer the bytes in the current page */
spin_lock_irqsave(&dev->lock, irq_flags);
- if (access_with_param(dev, CMD_WRITE_BUFFER + cmd_offset,
+ if (access_with_param(dev,
+ is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER,
address, avail, pipe, &status)) {
gf_write_ptr(pipe, dev->base + PIPE_REG_CHANNEL,
dev->base + PIPE_REG_CHANNEL_HIGH);
@@ -333,7 +326,7 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
gf_write_ptr((void *)address,
dev->base + PIPE_REG_ADDRESS,
dev->base + PIPE_REG_ADDRESS_HIGH);
- writel(CMD_WRITE_BUFFER + cmd_offset,
+ writel(is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER,
dev->base + PIPE_REG_COMMAND);
status = readl(dev->base + PIPE_REG_STATUS);
}
@@ -370,7 +363,8 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
set_bit(wakeBit, &pipe->flags);

/* Tell the emulator we're going to wait for a wake event */
- goldfish_cmd(pipe, CMD_WAKE_ON_WRITE + cmd_offset);
+ goldfish_cmd(pipe,
+ is_write ? CMD_WAKE_ON_WRITE : CMD_WAKE_ON_READ);

/* Unlock the pipe, then wait for the wake signal */
mutex_unlock(&pipe->lock);
--
2.6.0.rc2.230.g3dd15c0

2015-12-02 19:36:34

by Jin Qian

[permalink] [raw]
Subject: [PATCH v3 3/8] android_pipe: Pin pages to memory while copying and other cleanups

From: Christoffer Dall <[email protected]>

The existing code had a troubling TODO statement concerning the fact
that it just did a check if the page that the QEMU backend was going to
read from / write to was there before the call to the QEMU backend and
then relying on the fact that the page stayed around, even in a
preemptible SMP kernel. Obviously the page could go away or be
reassigned, and strange things may happen.

Further, writes were not tracked, so any use of COW or KSM-like
features would break completely. Probably that was never used by adbd
(the only current active user of the pipe), but could prove much more
dangerous for the GPU passthrough mechanism.

Instead, use get_user_pages() as the comment suggested and cleanup the
error path and add the set_page_dirt() call on a successful read
operation.

Also clarify the count used to return from successful read/write calls
and use Linux style commentary in various places of the file.

Note: The "just ignore error and return whatever we read so far" error
handling is really quite horrific. I cannot change it without a more
careful study of all user space ABIs reliance on this 'feature'.

Signed-off-by: Christoffer Dall <[email protected]>
Signed-off-by: Jin Qian <[email protected]>
---
drivers/platform/goldfish/goldfish_pipe.c | 129 +++++++++++++++++-------------
1 file changed, 72 insertions(+), 57 deletions(-)

diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index 0fb3a34..20a9337 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -2,6 +2,7 @@
* Copyright (C) 2011 Google, Inc.
* Copyright (C) 2012 Intel, Inc.
* Copyright (C) 2013 Intel, Inc.
+ * Copyright (C) 2014 Linaro Limited
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
@@ -57,6 +58,7 @@
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/goldfish.h>
+#include <linux/mm.h>

/*
* IMPORTANT: The following constants must match the ones used and defined
@@ -257,17 +259,14 @@ static int access_with_param(struct goldfish_pipe_dev *dev, const int cmd,
return 0;
}

-/* This function is used for both reading from and writing to a given
- * pipe.
- */
static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
- size_t bufflen, int is_write)
+ size_t bufflen, int is_write)
{
unsigned long irq_flags;
struct goldfish_pipe *pipe = filp->private_data;
struct goldfish_pipe_dev *dev = pipe->dev;
unsigned long address, address_end;
- int ret = 0;
+ int count = 0, ret = -EINVAL;

/* If the emulator already closed the pipe, no need to go further */
if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))
@@ -290,30 +289,23 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
address_end = address + bufflen;

while (address < address_end) {
- unsigned long page_end = (address & PAGE_MASK) + PAGE_SIZE;
- unsigned long next = page_end < address_end ? page_end
- : address_end;
- unsigned long avail = next - address;
+ unsigned long page_end = (address & PAGE_MASK) + PAGE_SIZE;
+ unsigned long next = page_end < address_end ? page_end
+ : address_end;
+ unsigned long avail = next - address;
int status, wakeBit;
-
- /* Ensure that the corresponding page is properly mapped */
- /* FIXME: this isn't safe or sufficient - use get_user_pages */
- if (is_write) {
- char c;
- /* Ensure that the page is mapped and readable */
- if (__get_user(c, (char __user *)address)) {
- if (!ret)
- ret = -EFAULT;
- break;
- }
- } else {
- /* Ensure that the page is mapped and writable */
- if (__put_user(0, (char __user *)address)) {
- if (!ret)
- ret = -EFAULT;
- break;
- }
- }
+ struct page *page;
+
+ /*
+ * We grab the pages on a page-by-page basis in case user
+ * space gives us a potentially huge buffer but the read only
+ * returns a small amount, then there's no need to pin that
+ * much memory to the process.
+ */
+ ret = get_user_pages(current, current->mm, address, 1,
+ !is_write, 0, &page, NULL);
+ if (ret < 0)
+ return ret;

/* Now, try to transfer the bytes in the current page */
spin_lock_irqsave(&dev->lock, irq_flags);
@@ -332,33 +324,48 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
}
spin_unlock_irqrestore(&dev->lock, irq_flags);

+ if (status > 0 && !is_write)
+ set_page_dirty(page);
+ put_page(page);
+
if (status > 0) { /* Correct transfer */
- ret += status;
+ count += status;
address += status;
continue;
- }
-
- if (status == 0) /* EOF */
+ } else if (status == 0) { /* EOF */
+ ret = 0;
break;
-
- /* An error occured. If we already transfered stuff, just
- * return with its count. We expect the next call to return
- * an error code */
- if (ret > 0)
+ } else if (status < 0 && count > 0) {
+ /*
+ * An error occurred and we already transferred
+ * something on one of the previous pages.
+ * Just return what we already copied and log this
+ * err.
+ *
+ * Note: This seems like an incorrect approach but
+ * cannot change it until we check if any user space
+ * ABI relies on this behavior.
+ */
+ pr_info_ratelimited("android_pipe: backend returned error %d on %s\n",
+ status, is_write ? "write" : "read");
+ ret = 0;
break;
+ }

- /* If the error is not PIPE_ERROR_AGAIN, or if we are not in
- * non-blocking mode, just return the error code.
- */
+ /*
+ * If the error is not PIPE_ERROR_AGAIN, or if we are not in
+ * non-blocking mode, just return the error code.
+ */
if (status != PIPE_ERROR_AGAIN ||
(filp->f_flags & O_NONBLOCK) != 0) {
ret = goldfish_pipe_error_convert(status);
break;
}

- /* We will have to wait until more data/space is available.
- * First, mark the pipe as waiting for a specific wake signal.
- */
+ /*
+ * The backend blocked the read/write, wait until the backend
+ * tells us it's ready to process more data.
+ */
wakeBit = is_write ? BIT_WAKE_ON_WRITE : BIT_WAKE_ON_READ;
set_bit(wakeBit, &pipe->flags);

@@ -372,22 +379,29 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
while (test_bit(wakeBit, &pipe->flags)) {
if (wait_event_interruptible(
pipe->wake_queue,
- !test_bit(wakeBit, &pipe->flags)))
- return -ERESTARTSYS;
+ !test_bit(wakeBit, &pipe->flags))) {
+ ret = -ERESTARTSYS;
+ break;
+ }

- if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))
- return -EIO;
+ if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags)) {
+ ret = -EIO;
+ break;
+ }
}

/* Try to re-acquire the lock */
- if (mutex_lock_interruptible(&pipe->lock))
- return -ERESTARTSYS;
-
- /* Try the transfer again */
- continue;
+ if (mutex_lock_interruptible(&pipe->lock)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
}
mutex_unlock(&pipe->lock);
- return ret;
+
+ if (ret < 0)
+ return ret;
+ else
+ return count;
}

static ssize_t goldfish_pipe_read(struct file *filp, char __user *buffer,
@@ -440,10 +454,11 @@ static irqreturn_t goldfish_pipe_interrupt(int irq, void *dev_id)
unsigned long irq_flags;
int count = 0;

- /* We're going to read from the emulator a list of (channel,flags)
- * pairs corresponding to the wake events that occured on each
- * blocked pipe (i.e. channel).
- */
+ /*
+ * We're going to read from the emulator a list of (channel,flags)
+ * pairs corresponding to the wake events that occurred on each
+ * blocked pipe (i.e. channel).
+ */
spin_lock_irqsave(&dev->lock, irq_flags);
for (;;) {
/* First read the channel, 0 means the end of the list */
--
2.6.0.rc2.230.g3dd15c0

2015-12-02 19:36:41

by Jin Qian

[permalink] [raw]
Subject: [PATCH v3 4/8] platform: goldfish: pipe: add devicetree bindings

From: Greg Hackmann <[email protected]>

Add bindings so we don't need to rely on goldfish virtual bus for
probing any more, which means we don't need ARM and MIPS goldfish
board code for instantiating the bus.

In the long term we would like to move towards replacing the Android
pipe with virtio-vsock that is currently under development.

Signed-off-by: Greg Hackmann <[email protected]>
Signed-off-by: Jin Qian <[email protected]>
---
Documentation/devicetree/bindings/goldfish/pipe.txt | 17 +++++++++++++++++
drivers/platform/goldfish/goldfish_pipe.c | 10 +++++++++-
2 files changed, 26 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/goldfish/pipe.txt

diff --git a/Documentation/devicetree/bindings/goldfish/pipe.txt b/Documentation/devicetree/bindings/goldfish/pipe.txt
new file mode 100644
index 0000000..e417a31
--- /dev/null
+++ b/Documentation/devicetree/bindings/goldfish/pipe.txt
@@ -0,0 +1,17 @@
+Android Goldfish QEMU Pipe
+
+Andorid pipe virtual device generated by android emulator.
+
+Required properties:
+
+- compatible : should contain "google,android-pipe" to match emulator
+- reg : <registers mapping>
+- interrupts : <interrupt mapping>
+
+Example:
+
+ android_pipe@a010000 {
+ compatible = "google,android-pipe";
+ reg = <ff018000 0x2000>;
+ interrupts = <0x12>;
+ };
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index 20a9337..0b187ff 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -624,11 +624,19 @@ static int goldfish_pipe_remove(struct platform_device *pdev)
return 0;
}

+static const struct of_device_id goldfish_pipe_of_match[] = {
+ { .compatible = "google,android-pipe", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, goldfish_pipe_of_match);
+
static struct platform_driver goldfish_pipe = {
.probe = goldfish_pipe_probe,
.remove = goldfish_pipe_remove,
.driver = {
- .name = "goldfish_pipe"
+ .name = "goldfish_pipe",
+ .owner = THIS_MODULE,
+ .of_match_table = goldfish_pipe_of_match,
}
};

--
2.6.0.rc2.230.g3dd15c0

2015-12-02 19:36:44

by Jin Qian

[permalink] [raw]
Subject: [PATCH v3 5/8] platform: goldfish: pipe: don't log when dropping PIPE_ERROR_AGAIN

From: Greg Hackmann <[email protected]>

On PIPE_ERROR_AGAIN, just stopping in the middle of a transfer and
returning the number of bytes actually handled is the right behavior.

Other errors should be returned on the next read() or write() call.
Continue logging those until we confirm nothing actually relies on the
existing (wrong) behavior of dropping errors on the floor.

Signed-off-by: Greg Hackmann <[email protected]>
Signed-off-by: Jin Qian <[email protected]>
---
drivers/platform/goldfish/goldfish_pipe.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index 0b187ff..7a56be9 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -346,7 +346,8 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
* cannot change it until we check if any user space
* ABI relies on this behavior.
*/
- pr_info_ratelimited("android_pipe: backend returned error %d on %s\n",
+ if (status != PIPE_ERROR_AGAIN)
+ pr_info_ratelimited("goldfish_pipe: backend returned error %d on %s\n",
status, is_write ? "write" : "read");
ret = 0;
break;
--
2.6.0.rc2.230.g3dd15c0

2015-12-02 19:36:48

by Jin Qian

[permalink] [raw]
Subject: [PATCH v3 6/8] [MIPS] Enable platform support for Goldfish virtual devices

From: Miodrag Dinic <[email protected]>

Enable CONFIG_GOLDFISH for MIPS platforms.

Signed-off-by: Miodrag Dinic <[email protected]>
Signed-off-by: Jin Qian <[email protected]>
---
drivers/platform/goldfish/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/goldfish/Kconfig b/drivers/platform/goldfish/Kconfig
index 1ae3690..f4f00f7 100644
--- a/drivers/platform/goldfish/Kconfig
+++ b/drivers/platform/goldfish/Kconfig
@@ -1,6 +1,6 @@
menuconfig GOLDFISH
bool "Platform support for Goldfish virtual devices"
- depends on X86_32 || X86_64 || ARM || ARM64
+ depends on X86_32 || X86_64 || ARM || ARM64 || MIPS
---help---
Say Y here to get to see options for the Goldfish virtual platform.
This option alone does not add any kernel code.
--
2.6.0.rc2.230.g3dd15c0

2015-12-02 19:36:52

by Jin Qian

[permalink] [raw]
Subject: [PATCH v3 7/8] goldfish_pipe: Pass physical addresses to the device if supported

From: Yu Ning <[email protected]>

For reading and writing guest user space buffers, currently the kernel
sends the guest virtual address of the buffer to the pipe device. This
virtual address has to be first converted to a guest physical address.
Doing this translation on the QEMU side is inefficient and requires
additional handling when KVM is enabled, whose implementation would
either incur intrusive changes to QEMU's KVM support code or suffer
from poor performance, see commit 08c7228c50f8 ("x86-kvm: only sync
SREGS when doing address translation") of $AOSP/external/qemu for
details, and thus should be avoided if possible.

There is a TODO comment in hw/misc/android_pipe.c in the new Android
emulator source tree ($AOSP/external/qemu-android) which requests that
the translation be done on the kernel side and that physical addresses
be passed to the device instead of virtual ones. Once the QEMU-side
implementation is done, the kernel will need to support both the new
paddr-based pipe device and the old vaddr-based one (which will
continue to be used by the classic emulator). This patch achieves that
by leveraging the device version register available in the new device.

See https://android-review.googlesource.com/128280 for the QEMU-side
patch.

In addition, use the mmap semaphore (in read mode) to safeguard the
call to get_user_pages().

Signed-off-by: Yu Ning <[email protected]>
Signed-off-by: Jin Qian <[email protected]>
---
drivers/platform/goldfish/goldfish_pipe.c | 29 +++++++++++++++++++++++++++--
1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index 7a56be9..c214434 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -77,6 +77,7 @@
#define PIPE_REG_PARAMS_ADDR_LOW 0x18 /* read/write: batch data address */
#define PIPE_REG_PARAMS_ADDR_HIGH 0x1c /* read/write: batch data address */
#define PIPE_REG_ACCESS_PARAMS 0x20 /* write: batch access */
+#define PIPE_REG_VERSION 0x24 /* read: device version */

/* list of commands for PIPE_REG_COMMAND */
#define CMD_OPEN 1 /* open new channel */
@@ -126,6 +127,7 @@ struct goldfish_pipe_dev {
unsigned char __iomem *base;
struct access_params *aps;
int irq;
+ u32 version;
};

static struct goldfish_pipe_dev pipe_dev[1];
@@ -296,26 +298,43 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
int status, wakeBit;
struct page *page;

+ /* Either vaddr or paddr depending on the device version */
+ unsigned long xaddr;
+
/*
* We grab the pages on a page-by-page basis in case user
* space gives us a potentially huge buffer but the read only
* returns a small amount, then there's no need to pin that
* much memory to the process.
*/
+ down_read(&current->mm->mmap_sem);
ret = get_user_pages(current, current->mm, address, 1,
!is_write, 0, &page, NULL);
+ up_read(&current->mm->mmap_sem);
if (ret < 0)
return ret;

+ if (dev->version) {
+ /* Device version 1 or newer (qemu-android) expects the
+ * physical address.
+ */
+ xaddr = page_to_phys(page) | (address & ~PAGE_MASK);
+ } else {
+ /* Device version 0 (classic emulator) expects the
+ * virtual address.
+ */
+ xaddr = address;
+ }
+
/* Now, try to transfer the bytes in the current page */
spin_lock_irqsave(&dev->lock, irq_flags);
if (access_with_param(dev,
is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER,
- address, avail, pipe, &status)) {
+ xaddr, avail, pipe, &status)) {
gf_write_ptr(pipe, dev->base + PIPE_REG_CHANNEL,
dev->base + PIPE_REG_CHANNEL_HIGH);
writel(avail, dev->base + PIPE_REG_SIZE);
- gf_write_ptr((void *)address,
+ gf_write_ptr((void *)xaddr,
dev->base + PIPE_REG_ADDRESS,
dev->base + PIPE_REG_ADDRESS_HIGH);
writel(is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER,
@@ -610,6 +629,12 @@ static int goldfish_pipe_probe(struct platform_device *pdev)
goto error;
}
setup_access_params_addr(pdev, dev);
+
+ /* Although the pipe device in the classic Android emulator does not
+ * recognize the 'version' register, it won't treat this as an error
+ * either and will simply return 0, which is fine.
+ */
+ dev->version = readl(dev->base + PIPE_REG_VERSION);
return 0;

error:
--
2.6.0.rc2.230.g3dd15c0

2015-12-02 19:44:34

by Jin Qian

[permalink] [raw]
Subject: [PATCH v3 8/8] goldfish: Enable ACPI-based enumeration for android pipe

From: Jason Hu <[email protected]>

Add ACPI binding to the android pipe driver

Signed-off-by: Jason Hu <[email protected]>
Signed-off-by: Jin Qian <[email protected]>
---
drivers/platform/goldfish/goldfish_pipe.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index c214434..e3fab9a 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -59,6 +59,7 @@
#include <linux/io.h>
#include <linux/goldfish.h>
#include <linux/mm.h>
+#include <linux/acpi.h>

/*
* IMPORTANT: The following constants must match the ones used and defined
@@ -650,6 +651,12 @@ static int goldfish_pipe_remove(struct platform_device *pdev)
return 0;
}

+static const struct acpi_device_id goldfish_pipe_acpi_match[] = {
+ { "GFSH0003", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, goldfish_pipe_acpi_match);
+
static const struct of_device_id goldfish_pipe_of_match[] = {
{ .compatible = "google,android-pipe", },
{},
@@ -663,6 +670,7 @@ static struct platform_driver goldfish_pipe = {
.name = "goldfish_pipe",
.owner = THIS_MODULE,
.of_match_table = goldfish_pipe_of_match,
+ .acpi_match_table = ACPI_PTR(goldfish_pipe_acpi_match),
}
};

--
2.6.0.rc2.230.g3dd15c0

2015-12-02 20:11:20

by Joe Perches

[permalink] [raw]
Subject: Re: [PATCH v3 2/8] android_pipe: don't be clever with #define offsets

On Wed, 2015-12-02 at 11:35 -0800, Jin Qian wrote:
> From: Alex Benn?e <[email protected]>
>
> You just make it harder to figure out when commands are being used.
>
> Signed-off-by: Alex Benn?e <[email protected]>
> Signed-off-by: Jin Qian <[email protected]>
> ---
> ?drivers/platform/goldfish/goldfish_pipe.c | 16 +++++-----------
> ?1 file changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
> index e7a29e2..0fb3a34 100644
> --- a/drivers/platform/goldfish/goldfish_pipe.c
> +++ b/drivers/platform/goldfish/goldfish_pipe.c
> @@ -90,12 +90,6 @@
> ?#define CMD_WRITE_BUFFER 4??/* send a user buffer to the emulator */
> ?#define CMD_WAKE_ON_WRITE 5??/* tell the emulator to wake us when writing
> ? ?????is possible */
> -
> -/* The following commands are related to read operations, they must be
> - * listed in the same order than the corresponding write ones, since we
> - * will use (CMD_READ_BUFFER - CMD_WRITE_BUFFER) as a special offset
> - * in goldfish_pipe_read_write() below.
> - */
> ?#define CMD_READ_BUFFER????????6??/* receive a user buffer from the emulator */
> ?#define CMD_WAKE_ON_READ???????7??/* tell the emulator to wake us when reading
> ? ???* is possible */
> @@ -272,8 +266,6 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
> ? unsigned long irq_flags;
> ? struct goldfish_pipe *pipe = filp->private_data;
> ? struct goldfish_pipe_dev *dev = pipe->dev;
> - const int cmd_offset = is_write ? 0
> - : (CMD_READ_BUFFER - CMD_WRITE_BUFFER);

This one could be
int cmd_type = is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER;
@@ -325,7 +317,8 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
> ?
> ? /* Now, try to transfer the bytes in the current page */
> ? spin_lock_irqsave(&dev->lock, irq_flags);
> - if (access_with_param(dev, CMD_WRITE_BUFFER + cmd_offset,
> + if (access_with_param(dev,
> + is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER,
> ? address, avail, pipe, &status)) {
> ? gf_write_ptr(pipe, dev->base + PIPE_REG_CHANNEL,
> ? ?????dev->base + PIPE_REG_CHANNEL_HIGH);
> @@ -333,7 +326,7 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
> ? gf_write_ptr((void *)address,
> ? ?????dev->base + PIPE_REG_ADDRESS,
> ? ?????dev->base + PIPE_REG_ADDRESS_HIGH);
> - writel(CMD_WRITE_BUFFER + cmd_offset,
> + writel(is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER,
> ? dev->base + PIPE_REG_COMMAND);
> ? status = readl(dev->base + PIPE_REG_STATUS);
> ? }

and the loop could use cmd_type instead of the ?:

> @@ -370,7 +363,8 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
> ? set_bit(wakeBit, &pipe->flags);
> ?
> ? /* Tell the emulator we're going to wait for a wake event */
> - goldfish_cmd(pipe, CMD_WAKE_ON_WRITE + cmd_offset);
> + goldfish_cmd(pipe,
> + is_write ? CMD_WAKE_ON_WRITE : CMD_WAKE_ON_READ);
> ?
> ? /* Unlock the pipe, then wait for the wake signal */
> ? mutex_unlock(&pipe->lock);

2015-12-04 14:57:21

by Rob Herring

[permalink] [raw]
Subject: Re: [PATCH v3 4/8] platform: goldfish: pipe: add devicetree bindings

On Wed, Dec 02, 2015 at 11:35:59AM -0800, Jin Qian wrote:
> From: Greg Hackmann <[email protected]>
>
> Add bindings so we don't need to rely on goldfish virtual bus for
> probing any more, which means we don't need ARM and MIPS goldfish
> board code for instantiating the bus.
>
> In the long term we would like to move towards replacing the Android
> pipe with virtio-vsock that is currently under development.
>
> Signed-off-by: Greg Hackmann <[email protected]>
> Signed-off-by: Jin Qian <[email protected]>

Acked-by: Rob Herring <[email protected]>

> ---
> Documentation/devicetree/bindings/goldfish/pipe.txt | 17 +++++++++++++++++
> drivers/platform/goldfish/goldfish_pipe.c | 10 +++++++++-
> 2 files changed, 26 insertions(+), 1 deletion(-)
> create mode 100644 Documentation/devicetree/bindings/goldfish/pipe.txt
>
> diff --git a/Documentation/devicetree/bindings/goldfish/pipe.txt b/Documentation/devicetree/bindings/goldfish/pipe.txt
> new file mode 100644
> index 0000000..e417a31
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/goldfish/pipe.txt
> @@ -0,0 +1,17 @@
> +Android Goldfish QEMU Pipe
> +
> +Andorid pipe virtual device generated by android emulator.
> +
> +Required properties:
> +
> +- compatible : should contain "google,android-pipe" to match emulator
> +- reg : <registers mapping>
> +- interrupts : <interrupt mapping>
> +
> +Example:
> +
> + android_pipe@a010000 {
> + compatible = "google,android-pipe";
> + reg = <ff018000 0x2000>;
> + interrupts = <0x12>;
> + };
> diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
> index 20a9337..0b187ff 100644
> --- a/drivers/platform/goldfish/goldfish_pipe.c
> +++ b/drivers/platform/goldfish/goldfish_pipe.c
> @@ -624,11 +624,19 @@ static int goldfish_pipe_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static const struct of_device_id goldfish_pipe_of_match[] = {
> + { .compatible = "google,android-pipe", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, goldfish_pipe_of_match);
> +
> static struct platform_driver goldfish_pipe = {
> .probe = goldfish_pipe_probe,
> .remove = goldfish_pipe_remove,
> .driver = {
> - .name = "goldfish_pipe"
> + .name = "goldfish_pipe",
> + .owner = THIS_MODULE,
> + .of_match_table = goldfish_pipe_of_match,
> }
> };
>
> --
> 2.6.0.rc2.230.g3dd15c0
>