2018-05-14 06:30:02

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: [PATCH v3 0/6] ALSA: xen-front: Add Xen para-virtualized frontend driver

From: Oleksandr Andrushchenko <[email protected]>

Please note: this patch series depends on [3].

This patch series adds support for Xen [1] para-virtualized
sound frontend driver. It implements the protocol from
include/xen/interface/io/sndif.h with the following limitations:
- mute/unmute is not supported
- get/set volume is not supported
Volume control is not supported for the reason that most of the
use-cases (at the moment) are based on scenarious where
unprivileged OS (e.g. Android, AGL etc) use software mixers.

Both capture and playback are supported.

Corresponding backend, implemented as a user-space application, can be
found at [2].

Thank you,
Oleksandr

Changes since v2:
*****************

1. Kconfig: select SND_PCM instead of depends
2. Changed spinlock to mutex for protecting the rings since
all the interrupts are threaded. Make those per event channel,
not a single global one. This also addresses Juergen's comment
on calling xen_snd_front_alsa_handle_cur_pos.
3. Fixed page leak on error while allocating an event channel
4. Fixed comments to start from a capital letter
5. Performed XEN_PAGE_SIZE != PAGE_SIZE check after xen_domain
and xen_has_pv_devices checks
6. Changed driver specific structures names not to mislead with ALSA
structs
7. Added comments on ring counters and overflows
8. Added MAINTAINERS entry

Changes since v1:
*****************

1. Moved driver from sound/drivers to sound/xen

2. Coding style changes to better meet Linux Kernel

3. Added explicit back and front synchronization
In order to provide explicit synchronization between backend and
frontend the following changes are introduced in the protocol:
- add new ring buffer for sending asynchronous events from
backend to frontend to report number of bytes played by the
frontend (XENSND_EVT_CUR_POS)
- introduce trigger events for playback control: start/stop/pause/resume
- add "req-" prefix to event-channel and ring-ref to unify naming
of the Xen event channels for requests and events

4. Added explicit back and front parameter negotiation
In order to provide explicit stream parameter negotiation between
backend and frontend the following changes are introduced in the protocol:
add XENSND_OP_HW_PARAM_QUERY request to read/update
configuration space for the parameters given: request passes
desired parameter's intervals/masks and the response to this request
returns allowed min/max intervals/masks to be used.

[1] https://xenproject.org/
[2] https://github.com/xen-troops/snd_be
[3] https://lkml.org/lkml/2018/4/12/522

Oleksandr Andrushchenko (6):
ALSA: xen-front: Introduce Xen para-virtualized sound frontend driver
ALSA: xen-front: Read sound driver configuration from Xen store
ALSA: xen-front: Implement Xen event channel handling
ALSA: xen-front: Implement handling of shared buffers
ALSA: xen-front: Implement ALSA virtual sound driver
MAINTAINERS: Add ALSA: xen-front: maintainer entry

MAINTAINERS | 7 +
sound/Kconfig | 2 +
sound/Makefile | 2 +-
sound/xen/Kconfig | 10 +
sound/xen/Makefile | 9 +
sound/xen/xen_snd_front.c | 397 +++++++++++++++
sound/xen/xen_snd_front.h | 54 ++
sound/xen/xen_snd_front_alsa.c | 821 ++++++++++++++++++++++++++++++
sound/xen/xen_snd_front_alsa.h | 23 +
sound/xen/xen_snd_front_cfg.c | 517 +++++++++++++++++++
sound/xen/xen_snd_front_cfg.h | 46 ++
sound/xen/xen_snd_front_evtchnl.c | 496 ++++++++++++++++++
sound/xen/xen_snd_front_evtchnl.h | 95 ++++
sound/xen/xen_snd_front_shbuf.c | 193 +++++++
sound/xen/xen_snd_front_shbuf.h | 36 ++
15 files changed, 2707 insertions(+), 1 deletion(-)
create mode 100644 sound/xen/Kconfig
create mode 100644 sound/xen/Makefile
create mode 100644 sound/xen/xen_snd_front.c
create mode 100644 sound/xen/xen_snd_front.h
create mode 100644 sound/xen/xen_snd_front_alsa.c
create mode 100644 sound/xen/xen_snd_front_alsa.h
create mode 100644 sound/xen/xen_snd_front_cfg.c
create mode 100644 sound/xen/xen_snd_front_cfg.h
create mode 100644 sound/xen/xen_snd_front_evtchnl.c
create mode 100644 sound/xen/xen_snd_front_evtchnl.h
create mode 100644 sound/xen/xen_snd_front_shbuf.c
create mode 100644 sound/xen/xen_snd_front_shbuf.h

--
2.17.0



2018-05-14 06:28:41

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: [PATCH v3 4/6] ALSA: xen-front: Implement handling of shared buffers

From: Oleksandr Andrushchenko <[email protected]>

Implement shared buffer handling according to the
para-virtualized sound device protocol at xen/interface/io/sndif.h:
- manage buffer memory
- handle granted references
- handle page directories

Signed-off-by: Oleksandr Andrushchenko <[email protected]>
---
sound/xen/Makefile | 3 +-
sound/xen/xen_snd_front.c | 8 ++
sound/xen/xen_snd_front_shbuf.c | 193 ++++++++++++++++++++++++++++++++
sound/xen/xen_snd_front_shbuf.h | 36 ++++++
4 files changed, 239 insertions(+), 1 deletion(-)
create mode 100644 sound/xen/xen_snd_front_shbuf.c
create mode 100644 sound/xen/xen_snd_front_shbuf.h

diff --git a/sound/xen/Makefile b/sound/xen/Makefile
index 03c669984000..f028bc30af5d 100644
--- a/sound/xen/Makefile
+++ b/sound/xen/Makefile
@@ -2,6 +2,7 @@

snd_xen_front-objs := xen_snd_front.o \
xen_snd_front_cfg.o \
- xen_snd_front_evtchnl.o
+ xen_snd_front_evtchnl.o \
+ xen_snd_front_shbuf.o

obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o
diff --git a/sound/xen/xen_snd_front.c b/sound/xen/xen_snd_front.c
index 277214d4fd0a..cdf66ea516c4 100644
--- a/sound/xen/xen_snd_front.c
+++ b/sound/xen/xen_snd_front.c
@@ -11,6 +11,7 @@
#include <linux/delay.h>
#include <linux/module.h>

+#include <xen/page.h>
#include <xen/platform_pci.h>
#include <xen/xen.h>
#include <xen/xenbus.h>
@@ -191,6 +192,13 @@ static int __init xen_drv_init(void)
if (!xen_has_pv_devices())
return -ENODEV;

+ /* At the moment we only support case with XEN_PAGE_SIZE == PAGE_SIZE */
+ if (XEN_PAGE_SIZE != PAGE_SIZE) {
+ pr_err(XENSND_DRIVER_NAME ": different kernel and Xen page sizes are not supported: XEN_PAGE_SIZE (%lu) != PAGE_SIZE (%lu)\n",
+ XEN_PAGE_SIZE, PAGE_SIZE);
+ return -ENODEV;
+ }
+
pr_info("Initialising Xen " XENSND_DRIVER_NAME " frontend driver\n");
return xenbus_register_frontend(&xen_driver);
}
diff --git a/sound/xen/xen_snd_front_shbuf.c b/sound/xen/xen_snd_front_shbuf.c
new file mode 100644
index 000000000000..6845dbc7fdf5
--- /dev/null
+++ b/sound/xen/xen_snd_front_shbuf.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <[email protected]>
+ */
+
+#include <xen/xen.h>
+#include <xen/xenbus.h>
+
+#include "xen_snd_front_shbuf.h"
+
+grant_ref_t xen_snd_front_shbuf_get_dir_start(struct xen_snd_front_shbuf *buf)
+{
+ if (!buf->grefs)
+ return GRANT_INVALID_REF;
+
+ return buf->grefs[0];
+}
+
+void xen_snd_front_shbuf_clear(struct xen_snd_front_shbuf *buf)
+{
+ memset(buf, 0, sizeof(*buf));
+}
+
+void xen_snd_front_shbuf_free(struct xen_snd_front_shbuf *buf)
+{
+ int i;
+
+ if (buf->grefs) {
+ for (i = 0; i < buf->num_grefs; i++)
+ if (buf->grefs[i] != GRANT_INVALID_REF)
+ gnttab_end_foreign_access(buf->grefs[i],
+ 0, 0UL);
+ kfree(buf->grefs);
+ }
+ kfree(buf->directory);
+ free_pages_exact(buf->buffer, buf->buffer_sz);
+ xen_snd_front_shbuf_clear(buf);
+}
+
+/*
+ * number of grant references a page can hold with respect to the
+ * xensnd_page_directory header
+ */
+#define XENSND_NUM_GREFS_PER_PAGE ((XEN_PAGE_SIZE - \
+ offsetof(struct xensnd_page_directory, gref)) / \
+ sizeof(grant_ref_t))
+
+static void fill_page_dir(struct xen_snd_front_shbuf *buf,
+ int num_pages_dir)
+{
+ struct xensnd_page_directory *page_dir;
+ unsigned char *ptr;
+ int i, cur_gref, grefs_left, to_copy;
+
+ ptr = buf->directory;
+ grefs_left = buf->num_grefs - num_pages_dir;
+ /*
+ * skip grant references at the beginning, they are for pages granted
+ * for the page directory itself
+ */
+ cur_gref = num_pages_dir;
+ for (i = 0; i < num_pages_dir; i++) {
+ page_dir = (struct xensnd_page_directory *)ptr;
+ if (grefs_left <= XENSND_NUM_GREFS_PER_PAGE) {
+ to_copy = grefs_left;
+ page_dir->gref_dir_next_page = GRANT_INVALID_REF;
+ } else {
+ to_copy = XENSND_NUM_GREFS_PER_PAGE;
+ page_dir->gref_dir_next_page = buf->grefs[i + 1];
+ }
+
+ memcpy(&page_dir->gref, &buf->grefs[cur_gref],
+ to_copy * sizeof(grant_ref_t));
+
+ ptr += XEN_PAGE_SIZE;
+ grefs_left -= to_copy;
+ cur_gref += to_copy;
+ }
+}
+
+static int grant_references(struct xenbus_device *xb_dev,
+ struct xen_snd_front_shbuf *buf,
+ int num_pages_dir, int num_pages_buffer,
+ int num_grefs)
+{
+ grant_ref_t priv_gref_head;
+ unsigned long frame;
+ int ret, i, j, cur_ref;
+ int otherend_id;
+
+ ret = gnttab_alloc_grant_references(num_grefs, &priv_gref_head);
+ if (ret)
+ return ret;
+
+ buf->num_grefs = num_grefs;
+ otherend_id = xb_dev->otherend_id;
+ j = 0;
+
+ for (i = 0; i < num_pages_dir; i++) {
+ cur_ref = gnttab_claim_grant_reference(&priv_gref_head);
+ if (cur_ref < 0) {
+ ret = cur_ref;
+ goto fail;
+ }
+
+ frame = xen_page_to_gfn(virt_to_page(buf->directory +
+ XEN_PAGE_SIZE * i));
+ gnttab_grant_foreign_access_ref(cur_ref, otherend_id, frame, 0);
+ buf->grefs[j++] = cur_ref;
+ }
+
+ for (i = 0; i < num_pages_buffer; i++) {
+ cur_ref = gnttab_claim_grant_reference(&priv_gref_head);
+ if (cur_ref < 0) {
+ ret = cur_ref;
+ goto fail;
+ }
+
+ frame = xen_page_to_gfn(virt_to_page(buf->buffer +
+ XEN_PAGE_SIZE * i));
+ gnttab_grant_foreign_access_ref(cur_ref, otherend_id, frame, 0);
+ buf->grefs[j++] = cur_ref;
+ }
+
+ gnttab_free_grant_references(priv_gref_head);
+ fill_page_dir(buf, num_pages_dir);
+ return 0;
+
+fail:
+ gnttab_free_grant_references(priv_gref_head);
+ return ret;
+}
+
+static int alloc_int_buffers(struct xen_snd_front_shbuf *buf,
+ int num_pages_dir, int num_pages_buffer,
+ int num_grefs)
+{
+ buf->grefs = kcalloc(num_grefs, sizeof(*buf->grefs), GFP_KERNEL);
+ if (!buf->grefs)
+ return -ENOMEM;
+
+ buf->directory = kcalloc(num_pages_dir, XEN_PAGE_SIZE, GFP_KERNEL);
+ if (!buf->directory)
+ goto fail;
+
+ buf->buffer_sz = num_pages_buffer * XEN_PAGE_SIZE;
+ buf->buffer = alloc_pages_exact(buf->buffer_sz, GFP_KERNEL);
+ if (!buf->buffer)
+ goto fail;
+
+ return 0;
+
+fail:
+ kfree(buf->grefs);
+ buf->grefs = NULL;
+ kfree(buf->directory);
+ buf->directory = NULL;
+ return -ENOMEM;
+}
+
+int xen_snd_front_shbuf_alloc(struct xenbus_device *xb_dev,
+ struct xen_snd_front_shbuf *buf,
+ unsigned int buffer_sz)
+{
+ int num_pages_buffer, num_pages_dir, num_grefs;
+ int ret;
+
+ xen_snd_front_shbuf_clear(buf);
+
+ num_pages_buffer = DIV_ROUND_UP(buffer_sz, XEN_PAGE_SIZE);
+ /* number of pages the page directory consumes itself */
+ num_pages_dir = DIV_ROUND_UP(num_pages_buffer,
+ XENSND_NUM_GREFS_PER_PAGE);
+ num_grefs = num_pages_buffer + num_pages_dir;
+
+ ret = alloc_int_buffers(buf, num_pages_dir,
+ num_pages_buffer, num_grefs);
+ if (ret < 0)
+ return ret;
+
+ ret = grant_references(xb_dev, buf, num_pages_dir, num_pages_buffer,
+ num_grefs);
+ if (ret < 0)
+ return ret;
+
+ fill_page_dir(buf, num_pages_dir);
+ return 0;
+}
diff --git a/sound/xen/xen_snd_front_shbuf.h b/sound/xen/xen_snd_front_shbuf.h
new file mode 100644
index 000000000000..d28e97c47b2c
--- /dev/null
+++ b/sound/xen/xen_snd_front_shbuf.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <[email protected]>
+ */
+
+#ifndef __XEN_SND_FRONT_SHBUF_H
+#define __XEN_SND_FRONT_SHBUF_H
+
+#include <xen/grant_table.h>
+
+#include "xen_snd_front_evtchnl.h"
+
+struct xen_snd_front_shbuf {
+ int num_grefs;
+ grant_ref_t *grefs;
+ u8 *directory;
+ u8 *buffer;
+ size_t buffer_sz;
+};
+
+grant_ref_t xen_snd_front_shbuf_get_dir_start(struct xen_snd_front_shbuf *buf);
+
+int xen_snd_front_shbuf_alloc(struct xenbus_device *xb_dev,
+ struct xen_snd_front_shbuf *buf,
+ unsigned int buffer_sz);
+
+void xen_snd_front_shbuf_clear(struct xen_snd_front_shbuf *buf);
+
+void xen_snd_front_shbuf_free(struct xen_snd_front_shbuf *buf);
+
+#endif /* __XEN_SND_FRONT_SHBUF_H */
--
2.17.0


2018-05-14 06:28:58

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: [PATCH v3 6/6] MAINTAINERS: Add ALSA: xen-front: maintainer entry

From: Oleksandr Andrushchenko <[email protected]>

Add myself as sound/xen maintainer.

Signed-off-by: Oleksandr Andrushchenko <[email protected]>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 92be777d060a..bd214e061359 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15494,6 +15494,13 @@ S: Supported
F: arch/x86/xen/*swiotlb*
F: drivers/xen/*swiotlb*

+XEN SOUND FRONTEND DRIVER
+M: Oleksandr Andrushchenko <[email protected]>
+L: [email protected] (moderated for non-subscribers)
+L: [email protected] (moderated for non-subscribers)
+S: Supported
+F: sound/xen/*
+
XFS FILESYSTEM
M: Darrick J. Wong <[email protected]>
M: [email protected]
--
2.17.0


2018-05-14 06:29:14

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: [PATCH v3 5/6] ALSA: xen-front: Implement ALSA virtual sound driver

From: Oleksandr Andrushchenko <[email protected]>

Implement essential initialization of the sound driver:
- introduce required data structures
- handle driver registration
- handle sound card registration
- register sound driver on backend connection
- remove sound driver on backend disconnect

Initialize virtual sound card with streams according to the
Xen store configuration.

Implement ALSA driver operations including:
- manage frontend/backend shared buffers
- manage Xen bus event channel states

Implement requests from front to back for ALSA
PCM operations.
- report ALSA period elapsed event: handle XENSND_EVT_CUR_POS
notifications from the backend when stream position advances
during playback/capture. The event carries a value of how
many octets were played/captured at the time of the event.
- implement explicit stream parameter negotiation between
backend and frontend: handle XENSND_OP_HW_PARAM_QUERY request
to read/update configuration space for the parameter given:
request passes desired parameter interval and the response to
this request returns min/max interval for the parameter to be used.

Signed-off-by: Oleksandr Andrushchenko <[email protected]>
---
sound/xen/Makefile | 3 +-
sound/xen/xen_snd_front.c | 181 ++++++-
sound/xen/xen_snd_front.h | 27 +
sound/xen/xen_snd_front_alsa.c | 821 ++++++++++++++++++++++++++++++
sound/xen/xen_snd_front_alsa.h | 23 +
sound/xen/xen_snd_front_evtchnl.c | 4 +-
6 files changed, 1056 insertions(+), 3 deletions(-)
create mode 100644 sound/xen/xen_snd_front_alsa.c
create mode 100644 sound/xen/xen_snd_front_alsa.h

diff --git a/sound/xen/Makefile b/sound/xen/Makefile
index f028bc30af5d..1e6470ecc2f2 100644
--- a/sound/xen/Makefile
+++ b/sound/xen/Makefile
@@ -3,6 +3,7 @@
snd_xen_front-objs := xen_snd_front.o \
xen_snd_front_cfg.o \
xen_snd_front_evtchnl.o \
- xen_snd_front_shbuf.o
+ xen_snd_front_shbuf.o \
+ xen_snd_front_alsa.o

obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o
diff --git a/sound/xen/xen_snd_front.c b/sound/xen/xen_snd_front.c
index cdf66ea516c4..c18973a9bc9b 100644
--- a/sound/xen/xen_snd_front.c
+++ b/sound/xen/xen_snd_front.c
@@ -19,10 +19,189 @@
#include <xen/interface/io/sndif.h>

#include "xen_snd_front.h"
+#include "xen_snd_front_alsa.h"
#include "xen_snd_front_evtchnl.h"
+#include "xen_snd_front_shbuf.h"
+
+static struct xensnd_req *
+be_stream_prepare_req(struct xen_snd_front_evtchnl *evtchnl, u8 operation)
+{
+ struct xensnd_req *req;
+
+ req = RING_GET_REQUEST(&evtchnl->u.req.ring,
+ evtchnl->u.req.ring.req_prod_pvt);
+ req->operation = operation;
+ req->id = evtchnl->evt_next_id++;
+ evtchnl->evt_id = req->id;
+ return req;
+}
+
+static int be_stream_do_io(struct xen_snd_front_evtchnl *evtchnl)
+{
+ if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED))
+ return -EIO;
+
+ reinit_completion(&evtchnl->u.req.completion);
+ xen_snd_front_evtchnl_flush(evtchnl);
+ return 0;
+}
+
+static int be_stream_wait_io(struct xen_snd_front_evtchnl *evtchnl)
+{
+ if (wait_for_completion_timeout(&evtchnl->u.req.completion,
+ msecs_to_jiffies(VSND_WAIT_BACK_MS)) <= 0)
+ return -ETIMEDOUT;
+
+ return evtchnl->u.req.resp_status;
+}
+
+int xen_snd_front_stream_query_hw_param(struct xen_snd_front_evtchnl *evtchnl,
+ struct xensnd_query_hw_param *hw_param_req,
+ struct xensnd_query_hw_param *hw_param_resp)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_HW_PARAM_QUERY);
+ req->op.hw_param = *hw_param_req;
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ if (ret == 0)
+ *hw_param_resp = evtchnl->u.req.resp.hw_param;
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}
+
+int xen_snd_front_stream_prepare(struct xen_snd_front_evtchnl *evtchnl,
+ struct xen_snd_front_shbuf *sh_buf,
+ u8 format, unsigned int channels,
+ unsigned int rate, u32 buffer_sz,
+ u32 period_sz)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_OPEN);
+ req->op.open.pcm_format = format;
+ req->op.open.pcm_channels = channels;
+ req->op.open.pcm_rate = rate;
+ req->op.open.buffer_sz = buffer_sz;
+ req->op.open.period_sz = period_sz;
+ req->op.open.gref_directory = xen_snd_front_shbuf_get_dir_start(sh_buf);
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}
+
+int xen_snd_front_stream_close(struct xen_snd_front_evtchnl *evtchnl)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_CLOSE);
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}
+
+int xen_snd_front_stream_write(struct xen_snd_front_evtchnl *evtchnl,
+ unsigned long pos, unsigned long count)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_WRITE);
+ req->op.rw.length = count;
+ req->op.rw.offset = pos;
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}
+
+int xen_snd_front_stream_read(struct xen_snd_front_evtchnl *evtchnl,
+ unsigned long pos, unsigned long count)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_READ);
+ req->op.rw.length = count;
+ req->op.rw.offset = pos;
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}
+
+int xen_snd_front_stream_trigger(struct xen_snd_front_evtchnl *evtchnl,
+ int type)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_TRIGGER);
+ req->op.trigger.type = type;
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}

static void xen_snd_drv_fini(struct xen_snd_front_info *front_info)
{
+ xen_snd_front_alsa_fini(front_info);
xen_snd_front_evtchnl_free_all(front_info);
}

@@ -45,7 +224,7 @@ static int sndback_initwait(struct xen_snd_front_info *front_info)

static int sndback_connect(struct xen_snd_front_info *front_info)
{
- return 0;
+ return xen_snd_front_alsa_init(front_info);
}

static void sndback_disconnect(struct xen_snd_front_info *front_info)
diff --git a/sound/xen/xen_snd_front.h b/sound/xen/xen_snd_front.h
index 9d0c92100c7b..a2ea2463bcc5 100644
--- a/sound/xen/xen_snd_front.h
+++ b/sound/xen/xen_snd_front.h
@@ -13,15 +13,42 @@

#include "xen_snd_front_cfg.h"

+struct xen_snd_front_card_info;
+struct xen_snd_front_evtchnl;
struct xen_snd_front_evtchnl_pair;
+struct xen_snd_front_shbuf;
+struct xensnd_query_hw_param;

struct xen_snd_front_info {
struct xenbus_device *xb_dev;

+ struct xen_snd_front_card_info *card_info;
+
int num_evt_pairs;
struct xen_snd_front_evtchnl_pair *evt_pairs;

struct xen_front_cfg_card cfg;
};

+int xen_snd_front_stream_query_hw_param(struct xen_snd_front_evtchnl *evtchnl,
+ struct xensnd_query_hw_param *hw_param_req,
+ struct xensnd_query_hw_param *hw_param_resp);
+
+int xen_snd_front_stream_prepare(struct xen_snd_front_evtchnl *evtchnl,
+ struct xen_snd_front_shbuf *sh_buf,
+ u8 format, unsigned int channels,
+ unsigned int rate, u32 buffer_sz,
+ u32 period_sz);
+
+int xen_snd_front_stream_close(struct xen_snd_front_evtchnl *evtchnl);
+
+int xen_snd_front_stream_write(struct xen_snd_front_evtchnl *evtchnl,
+ unsigned long pos, unsigned long count);
+
+int xen_snd_front_stream_read(struct xen_snd_front_evtchnl *evtchnl,
+ unsigned long pos, unsigned long count);
+
+int xen_snd_front_stream_trigger(struct xen_snd_front_evtchnl *evtchnl,
+ int type);
+
#endif /* __XEN_SND_FRONT_H */
diff --git a/sound/xen/xen_snd_front_alsa.c b/sound/xen/xen_snd_front_alsa.c
new file mode 100644
index 000000000000..5041f83e98d2
--- /dev/null
+++ b/sound/xen/xen_snd_front_alsa.c
@@ -0,0 +1,821 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <[email protected]>
+ */
+
+#include <linux/platform_device.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+
+#include <xen/xenbus.h>
+
+#include "xen_snd_front.h"
+#include "xen_snd_front_alsa.h"
+#include "xen_snd_front_cfg.h"
+#include "xen_snd_front_evtchnl.h"
+#include "xen_snd_front_shbuf.h"
+
+struct xen_snd_front_pcm_stream_info {
+ struct xen_snd_front_info *front_info;
+ struct xen_snd_front_evtchnl_pair *evt_pair;
+ struct xen_snd_front_shbuf sh_buf;
+ int index;
+
+ bool is_open;
+ struct snd_pcm_hardware pcm_hw;
+
+ /* Number of processed frames as reported by the backend. */
+ snd_pcm_uframes_t be_cur_frame;
+ /* Current HW pointer to be reported via .period callback. */
+ atomic_t hw_ptr;
+ /* Modulo of the number of processed frames - for period detection. */
+ u32 out_frames;
+};
+
+struct xen_snd_front_pcm_instance_info {
+ struct xen_snd_front_card_info *card_info;
+ struct snd_pcm *pcm;
+ struct snd_pcm_hardware pcm_hw;
+ int num_pcm_streams_pb;
+ struct xen_snd_front_pcm_stream_info *streams_pb;
+ int num_pcm_streams_cap;
+ struct xen_snd_front_pcm_stream_info *streams_cap;
+};
+
+struct xen_snd_front_card_info {
+ struct xen_snd_front_info *front_info;
+ struct snd_card *card;
+ struct snd_pcm_hardware pcm_hw;
+ int num_pcm_instances;
+ struct xen_snd_front_pcm_instance_info *pcm_instances;
+};
+
+struct alsa_sndif_sample_format {
+ u8 sndif;
+ snd_pcm_format_t alsa;
+};
+
+struct alsa_sndif_hw_param {
+ u8 sndif;
+ snd_pcm_hw_param_t alsa;
+};
+
+static const struct alsa_sndif_sample_format ALSA_SNDIF_FORMATS[] = {
+ {
+ .sndif = XENSND_PCM_FORMAT_U8,
+ .alsa = SNDRV_PCM_FORMAT_U8
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_S8,
+ .alsa = SNDRV_PCM_FORMAT_S8
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_U16_LE,
+ .alsa = SNDRV_PCM_FORMAT_U16_LE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_U16_BE,
+ .alsa = SNDRV_PCM_FORMAT_U16_BE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_S16_LE,
+ .alsa = SNDRV_PCM_FORMAT_S16_LE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_S16_BE,
+ .alsa = SNDRV_PCM_FORMAT_S16_BE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_U24_LE,
+ .alsa = SNDRV_PCM_FORMAT_U24_LE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_U24_BE,
+ .alsa = SNDRV_PCM_FORMAT_U24_BE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_S24_LE,
+ .alsa = SNDRV_PCM_FORMAT_S24_LE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_S24_BE,
+ .alsa = SNDRV_PCM_FORMAT_S24_BE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_U32_LE,
+ .alsa = SNDRV_PCM_FORMAT_U32_LE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_U32_BE,
+ .alsa = SNDRV_PCM_FORMAT_U32_BE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_S32_LE,
+ .alsa = SNDRV_PCM_FORMAT_S32_LE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_S32_BE,
+ .alsa = SNDRV_PCM_FORMAT_S32_BE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_A_LAW,
+ .alsa = SNDRV_PCM_FORMAT_A_LAW
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_MU_LAW,
+ .alsa = SNDRV_PCM_FORMAT_MU_LAW
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_F32_LE,
+ .alsa = SNDRV_PCM_FORMAT_FLOAT_LE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_F32_BE,
+ .alsa = SNDRV_PCM_FORMAT_FLOAT_BE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_F64_LE,
+ .alsa = SNDRV_PCM_FORMAT_FLOAT64_LE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_F64_BE,
+ .alsa = SNDRV_PCM_FORMAT_FLOAT64_BE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE,
+ .alsa = SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE,
+ .alsa = SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_IMA_ADPCM,
+ .alsa = SNDRV_PCM_FORMAT_IMA_ADPCM
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_MPEG,
+ .alsa = SNDRV_PCM_FORMAT_MPEG
+ },
+ {
+ .sndif = XENSND_PCM_FORMAT_GSM,
+ .alsa = SNDRV_PCM_FORMAT_GSM
+ },
+};
+
+static int to_sndif_format(snd_pcm_format_t format)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
+ if (ALSA_SNDIF_FORMATS[i].alsa == format)
+ return ALSA_SNDIF_FORMATS[i].sndif;
+
+ return -EINVAL;
+}
+
+static u64 to_sndif_formats_mask(u64 alsa_formats)
+{
+ u64 mask;
+ int i;
+
+ mask = 0;
+ for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
+ if (1 << ALSA_SNDIF_FORMATS[i].alsa & alsa_formats)
+ mask |= 1 << ALSA_SNDIF_FORMATS[i].sndif;
+
+ return mask;
+}
+
+static u64 to_alsa_formats_mask(u64 sndif_formats)
+{
+ u64 mask;
+ int i;
+
+ mask = 0;
+ for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
+ if (1 << ALSA_SNDIF_FORMATS[i].sndif & sndif_formats)
+ mask |= 1 << ALSA_SNDIF_FORMATS[i].alsa;
+
+ return mask;
+}
+
+static void stream_clear(struct xen_snd_front_pcm_stream_info *stream)
+{
+ stream->is_open = false;
+ stream->be_cur_frame = 0;
+ stream->out_frames = 0;
+ atomic_set(&stream->hw_ptr, 0);
+ xen_snd_front_evtchnl_pair_clear(stream->evt_pair);
+ xen_snd_front_shbuf_clear(&stream->sh_buf);
+}
+
+static void stream_free(struct xen_snd_front_pcm_stream_info *stream)
+{
+ xen_snd_front_shbuf_free(&stream->sh_buf);
+ stream_clear(stream);
+}
+
+static struct xen_snd_front_pcm_stream_info *
+stream_get(struct snd_pcm_substream *substream)
+{
+ struct xen_snd_front_pcm_instance_info *pcm_instance =
+ snd_pcm_substream_chip(substream);
+ struct xen_snd_front_pcm_stream_info *stream;
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ stream = &pcm_instance->streams_pb[substream->number];
+ else
+ stream = &pcm_instance->streams_cap[substream->number];
+
+ return stream;
+}
+
+static int alsa_hw_rule(struct snd_pcm_hw_params *params,
+ struct snd_pcm_hw_rule *rule)
+{
+ struct xen_snd_front_pcm_stream_info *stream = rule->private;
+ struct device *dev = &stream->front_info->xb_dev->dev;
+ struct snd_mask *formats =
+ hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
+ struct snd_interval *rates =
+ hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
+ struct snd_interval *channels =
+ hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
+ struct snd_interval *period =
+ hw_param_interval(params,
+ SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
+ struct snd_interval *buffer =
+ hw_param_interval(params,
+ SNDRV_PCM_HW_PARAM_BUFFER_SIZE);
+ struct xensnd_query_hw_param req;
+ struct xensnd_query_hw_param resp;
+ struct snd_interval interval;
+ struct snd_mask mask;
+ u64 sndif_formats;
+ int changed, ret;
+
+ /* Collect all the values we need for the query. */
+
+ req.formats = to_sndif_formats_mask((u64)formats->bits[0] |
+ (u64)(formats->bits[1]) << 32);
+
+ req.rates.min = rates->min;
+ req.rates.max = rates->max;
+
+ req.channels.min = channels->min;
+ req.channels.max = channels->max;
+
+ req.buffer.min = buffer->min;
+ req.buffer.max = buffer->max;
+
+ req.period.min = period->min;
+ req.period.max = period->max;
+
+ ret = xen_snd_front_stream_query_hw_param(&stream->evt_pair->req,
+ &req, &resp);
+ if (ret < 0) {
+ /* Check if this is due to backend communication error. */
+ if (ret == -EIO || ret == -ETIMEDOUT)
+ dev_err(dev, "Failed to query ALSA HW parameters\n");
+ return ret;
+ }
+
+ /* Refine HW parameters after the query. */
+ changed = 0;
+
+ sndif_formats = to_alsa_formats_mask(resp.formats);
+ snd_mask_none(&mask);
+ mask.bits[0] = (u32)sndif_formats;
+ mask.bits[1] = (u32)(sndif_formats >> 32);
+ ret = snd_mask_refine(formats, &mask);
+ if (ret < 0)
+ return ret;
+ changed |= ret;
+
+ interval.openmin = 0;
+ interval.openmax = 0;
+ interval.integer = 1;
+
+ interval.min = resp.rates.min;
+ interval.max = resp.rates.max;
+ ret = snd_interval_refine(rates, &interval);
+ if (ret < 0)
+ return ret;
+ changed |= ret;
+
+ interval.min = resp.channels.min;
+ interval.max = resp.channels.max;
+ ret = snd_interval_refine(channels, &interval);
+ if (ret < 0)
+ return ret;
+ changed |= ret;
+
+ interval.min = resp.buffer.min;
+ interval.max = resp.buffer.max;
+ ret = snd_interval_refine(buffer, &interval);
+ if (ret < 0)
+ return ret;
+ changed |= ret;
+
+ interval.min = resp.period.min;
+ interval.max = resp.period.max;
+ ret = snd_interval_refine(period, &interval);
+ if (ret < 0)
+ return ret;
+ changed |= ret;
+
+ return changed;
+}
+
+static int alsa_open(struct snd_pcm_substream *substream)
+{
+ struct xen_snd_front_pcm_instance_info *pcm_instance =
+ snd_pcm_substream_chip(substream);
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct xen_snd_front_info *front_info =
+ pcm_instance->card_info->front_info;
+ struct device *dev = &front_info->xb_dev->dev;
+ int ret;
+
+ /*
+ * Return our HW properties: override defaults with those configured
+ * via XenStore.
+ */
+ runtime->hw = stream->pcm_hw;
+ runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
+ SNDRV_PCM_INFO_MMAP_VALID |
+ SNDRV_PCM_INFO_DOUBLE |
+ SNDRV_PCM_INFO_BATCH |
+ SNDRV_PCM_INFO_NONINTERLEAVED |
+ SNDRV_PCM_INFO_RESUME |
+ SNDRV_PCM_INFO_PAUSE);
+ runtime->hw.info |= SNDRV_PCM_INFO_INTERLEAVED;
+
+ stream->evt_pair = &front_info->evt_pairs[stream->index];
+
+ stream->front_info = front_info;
+
+ stream->evt_pair->evt.u.evt.substream = substream;
+
+ stream_clear(stream);
+
+ xen_snd_front_evtchnl_pair_set_connected(stream->evt_pair, true);
+
+ ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
+ alsa_hw_rule, stream,
+ SNDRV_PCM_HW_PARAM_FORMAT, -1);
+ if (ret) {
+ dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_FORMAT\n");
+ return ret;
+ }
+
+ ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
+ alsa_hw_rule, stream,
+ SNDRV_PCM_HW_PARAM_RATE, -1);
+ if (ret) {
+ dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_RATE\n");
+ return ret;
+ }
+
+ ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
+ alsa_hw_rule, stream,
+ SNDRV_PCM_HW_PARAM_CHANNELS, -1);
+ if (ret) {
+ dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_CHANNELS\n");
+ return ret;
+ }
+
+ ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
+ alsa_hw_rule, stream,
+ SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
+ if (ret) {
+ dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_PERIOD_SIZE\n");
+ return ret;
+ }
+
+ ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
+ alsa_hw_rule, stream,
+ SNDRV_PCM_HW_PARAM_BUFFER_SIZE, -1);
+ if (ret) {
+ dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_BUFFER_SIZE\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int alsa_close(struct snd_pcm_substream *substream)
+{
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+
+ xen_snd_front_evtchnl_pair_set_connected(stream->evt_pair, false);
+ return 0;
+}
+
+static int alsa_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+ int ret;
+
+ /*
+ * This callback may be called multiple times,
+ * so free the previously allocated shared buffer if any.
+ */
+ stream_free(stream);
+
+ ret = xen_snd_front_shbuf_alloc(stream->front_info->xb_dev,
+ &stream->sh_buf,
+ params_buffer_bytes(params));
+ if (ret < 0) {
+ stream_free(stream);
+ dev_err(&stream->front_info->xb_dev->dev,
+ "Failed to allocate buffers for stream with index %d\n",
+ stream->index);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int alsa_hw_free(struct snd_pcm_substream *substream)
+{
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+ int ret;
+
+ ret = xen_snd_front_stream_close(&stream->evt_pair->req);
+ stream_free(stream);
+ return ret;
+}
+
+static int alsa_prepare(struct snd_pcm_substream *substream)
+{
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+
+ if (!stream->is_open) {
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ u8 sndif_format;
+ int ret;
+
+ sndif_format = to_sndif_format(runtime->format);
+ if (sndif_format < 0) {
+ dev_err(&stream->front_info->xb_dev->dev,
+ "Unsupported sample format: %d\n",
+ runtime->format);
+ return sndif_format;
+ }
+
+ ret = xen_snd_front_stream_prepare(&stream->evt_pair->req,
+ &stream->sh_buf,
+ sndif_format,
+ runtime->channels,
+ runtime->rate,
+ snd_pcm_lib_buffer_bytes(substream),
+ snd_pcm_lib_period_bytes(substream));
+ if (ret < 0)
+ return ret;
+
+ stream->is_open = true;
+ }
+
+ return 0;
+}
+
+static int alsa_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+ int type;
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ type = XENSND_OP_TRIGGER_START;
+ break;
+
+ case SNDRV_PCM_TRIGGER_RESUME:
+ type = XENSND_OP_TRIGGER_RESUME;
+ break;
+
+ case SNDRV_PCM_TRIGGER_STOP:
+ type = XENSND_OP_TRIGGER_STOP;
+ break;
+
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ type = XENSND_OP_TRIGGER_PAUSE;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return xen_snd_front_stream_trigger(&stream->evt_pair->req, type);
+}
+
+void xen_snd_front_alsa_handle_cur_pos(struct xen_snd_front_evtchnl *evtchnl,
+ u64 pos_bytes)
+{
+ struct snd_pcm_substream *substream = evtchnl->u.evt.substream;
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+ snd_pcm_uframes_t delta, new_hw_ptr, cur_frame;
+
+ cur_frame = bytes_to_frames(substream->runtime, pos_bytes);
+
+ delta = cur_frame - stream->be_cur_frame;
+ stream->be_cur_frame = cur_frame;
+
+ new_hw_ptr = (snd_pcm_uframes_t)atomic_read(&stream->hw_ptr);
+ new_hw_ptr = (new_hw_ptr + delta) % substream->runtime->buffer_size;
+ atomic_set(&stream->hw_ptr, (int)new_hw_ptr);
+
+ stream->out_frames += delta;
+ if (stream->out_frames > substream->runtime->period_size) {
+ stream->out_frames %= substream->runtime->period_size;
+ snd_pcm_period_elapsed(substream);
+ }
+}
+
+static snd_pcm_uframes_t alsa_pointer(struct snd_pcm_substream *substream)
+{
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+
+ return (snd_pcm_uframes_t)atomic_read(&stream->hw_ptr);
+}
+
+static int alsa_pb_copy_user(struct snd_pcm_substream *substream,
+ int channel, unsigned long pos, void __user *src,
+ unsigned long count)
+{
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+
+ if (unlikely(pos + count > stream->sh_buf.buffer_sz))
+ return -EINVAL;
+
+ if (copy_from_user(stream->sh_buf.buffer + pos, src, count))
+ return -EFAULT;
+
+ return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
+}
+
+static int alsa_pb_copy_kernel(struct snd_pcm_substream *substream,
+ int channel, unsigned long pos, void *src,
+ unsigned long count)
+{
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+
+ if (unlikely(pos + count > stream->sh_buf.buffer_sz))
+ return -EINVAL;
+
+ memcpy(stream->sh_buf.buffer + pos, src, count);
+
+ return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
+}
+
+static int alsa_cap_copy_user(struct snd_pcm_substream *substream,
+ int channel, unsigned long pos, void __user *dst,
+ unsigned long count)
+{
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+ int ret;
+
+ if (unlikely(pos + count > stream->sh_buf.buffer_sz))
+ return -EINVAL;
+
+ ret = xen_snd_front_stream_read(&stream->evt_pair->req, pos, count);
+ if (ret < 0)
+ return ret;
+
+ return copy_to_user(dst, stream->sh_buf.buffer + pos, count) ?
+ -EFAULT : 0;
+}
+
+static int alsa_cap_copy_kernel(struct snd_pcm_substream *substream,
+ int channel, unsigned long pos, void *dst,
+ unsigned long count)
+{
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+ int ret;
+
+ if (unlikely(pos + count > stream->sh_buf.buffer_sz))
+ return -EINVAL;
+
+ ret = xen_snd_front_stream_read(&stream->evt_pair->req, pos, count);
+ if (ret < 0)
+ return ret;
+
+ memcpy(dst, stream->sh_buf.buffer + pos, count);
+
+ return 0;
+}
+
+static int alsa_pb_fill_silence(struct snd_pcm_substream *substream,
+ int channel, unsigned long pos,
+ unsigned long count)
+{
+ struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
+
+ if (unlikely(pos + count > stream->sh_buf.buffer_sz))
+ return -EINVAL;
+
+ memset(stream->sh_buf.buffer + pos, 0, count);
+
+ return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
+}
+
+/*
+ * FIXME: The mmaped data transfer is asynchronous and there is no
+ * ack signal from user-space when it is done. This is the
+ * reason it is not implemented in the PV driver as we do need
+ * to know when the buffer can be transferred to the backend.
+ */
+
+static struct snd_pcm_ops snd_drv_alsa_playback_ops = {
+ .open = alsa_open,
+ .close = alsa_close,
+ .ioctl = snd_pcm_lib_ioctl,
+ .hw_params = alsa_hw_params,
+ .hw_free = alsa_hw_free,
+ .prepare = alsa_prepare,
+ .trigger = alsa_trigger,
+ .pointer = alsa_pointer,
+ .copy_user = alsa_pb_copy_user,
+ .copy_kernel = alsa_pb_copy_kernel,
+ .fill_silence = alsa_pb_fill_silence,
+};
+
+static struct snd_pcm_ops snd_drv_alsa_capture_ops = {
+ .open = alsa_open,
+ .close = alsa_close,
+ .ioctl = snd_pcm_lib_ioctl,
+ .hw_params = alsa_hw_params,
+ .hw_free = alsa_hw_free,
+ .prepare = alsa_prepare,
+ .trigger = alsa_trigger,
+ .pointer = alsa_pointer,
+ .copy_user = alsa_cap_copy_user,
+ .copy_kernel = alsa_cap_copy_kernel,
+};
+
+static int new_pcm_instance(struct xen_snd_front_card_info *card_info,
+ struct xen_front_cfg_pcm_instance *instance_cfg,
+ struct xen_snd_front_pcm_instance_info *pcm_instance_info)
+{
+ struct snd_pcm *pcm;
+ int ret, i;
+
+ dev_dbg(&card_info->front_info->xb_dev->dev,
+ "New PCM device \"%s\" with id %d playback %d capture %d",
+ instance_cfg->name,
+ instance_cfg->device_id,
+ instance_cfg->num_streams_pb,
+ instance_cfg->num_streams_cap);
+
+ pcm_instance_info->card_info = card_info;
+
+ pcm_instance_info->pcm_hw = instance_cfg->pcm_hw;
+
+ if (instance_cfg->num_streams_pb) {
+ pcm_instance_info->streams_pb =
+ devm_kcalloc(&card_info->card->card_dev,
+ instance_cfg->num_streams_pb,
+ sizeof(struct xen_snd_front_pcm_stream_info),
+ GFP_KERNEL);
+ if (!pcm_instance_info->streams_pb)
+ return -ENOMEM;
+ }
+
+ if (instance_cfg->num_streams_cap) {
+ pcm_instance_info->streams_cap =
+ devm_kcalloc(&card_info->card->card_dev,
+ instance_cfg->num_streams_cap,
+ sizeof(struct xen_snd_front_pcm_stream_info),
+ GFP_KERNEL);
+ if (!pcm_instance_info->streams_cap)
+ return -ENOMEM;
+ }
+
+ pcm_instance_info->num_pcm_streams_pb =
+ instance_cfg->num_streams_pb;
+ pcm_instance_info->num_pcm_streams_cap =
+ instance_cfg->num_streams_cap;
+
+ for (i = 0; i < pcm_instance_info->num_pcm_streams_pb; i++) {
+ pcm_instance_info->streams_pb[i].pcm_hw =
+ instance_cfg->streams_pb[i].pcm_hw;
+ pcm_instance_info->streams_pb[i].index =
+ instance_cfg->streams_pb[i].index;
+ }
+
+ for (i = 0; i < pcm_instance_info->num_pcm_streams_cap; i++) {
+ pcm_instance_info->streams_cap[i].pcm_hw =
+ instance_cfg->streams_cap[i].pcm_hw;
+ pcm_instance_info->streams_cap[i].index =
+ instance_cfg->streams_cap[i].index;
+ }
+
+ ret = snd_pcm_new(card_info->card, instance_cfg->name,
+ instance_cfg->device_id,
+ instance_cfg->num_streams_pb,
+ instance_cfg->num_streams_cap,
+ &pcm);
+ if (ret < 0)
+ return ret;
+
+ pcm->private_data = pcm_instance_info;
+ pcm->info_flags = 0;
+ /* we want to handle all PCM operations in non-atomic context */
+ pcm->nonatomic = true;
+ strncpy(pcm->name, "Virtual card PCM", sizeof(pcm->name));
+
+ if (instance_cfg->num_streams_pb)
+ snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
+ &snd_drv_alsa_playback_ops);
+
+ if (instance_cfg->num_streams_cap)
+ snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
+ &snd_drv_alsa_capture_ops);
+
+ pcm_instance_info->pcm = pcm;
+ return 0;
+}
+
+int xen_snd_front_alsa_init(struct xen_snd_front_info *front_info)
+{
+ struct device *dev = &front_info->xb_dev->dev;
+ struct xen_front_cfg_card *cfg = &front_info->cfg;
+ struct xen_snd_front_card_info *card_info;
+ struct snd_card *card;
+ int ret, i;
+
+ dev_dbg(dev, "Creating virtual sound card\n");
+
+ ret = snd_card_new(dev, 0, XENSND_DRIVER_NAME, THIS_MODULE,
+ sizeof(struct xen_snd_front_card_info), &card);
+ if (ret < 0)
+ return ret;
+
+ card_info = card->private_data;
+ card_info->front_info = front_info;
+ front_info->card_info = card_info;
+ card_info->card = card;
+ card_info->pcm_instances =
+ devm_kcalloc(dev, cfg->num_pcm_instances,
+ sizeof(struct xen_snd_front_pcm_instance_info),
+ GFP_KERNEL);
+ if (!card_info->pcm_instances) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ card_info->num_pcm_instances = cfg->num_pcm_instances;
+ card_info->pcm_hw = cfg->pcm_hw;
+
+ for (i = 0; i < cfg->num_pcm_instances; i++) {
+ ret = new_pcm_instance(card_info, &cfg->pcm_instances[i],
+ &card_info->pcm_instances[i]);
+ if (ret < 0)
+ goto fail;
+ }
+
+ strncpy(card->driver, XENSND_DRIVER_NAME, sizeof(card->driver));
+ strncpy(card->shortname, cfg->name_short, sizeof(card->shortname));
+ strncpy(card->longname, cfg->name_long, sizeof(card->longname));
+
+ ret = snd_card_register(card);
+ if (ret < 0)
+ goto fail;
+
+ return 0;
+
+fail:
+ snd_card_free(card);
+ return ret;
+}
+
+void xen_snd_front_alsa_fini(struct xen_snd_front_info *front_info)
+{
+ struct xen_snd_front_card_info *card_info;
+ struct snd_card *card;
+
+ card_info = front_info->card_info;
+ if (!card_info)
+ return;
+
+ card = card_info->card;
+ if (!card)
+ return;
+
+ dev_dbg(&front_info->xb_dev->dev, "Removing virtual sound card %d\n",
+ card->number);
+ snd_card_free(card);
+
+ /* Card_info will be freed when destroying front_info->xb_dev->dev. */
+ card_info->card = NULL;
+}
diff --git a/sound/xen/xen_snd_front_alsa.h b/sound/xen/xen_snd_front_alsa.h
new file mode 100644
index 000000000000..18abd9eec967
--- /dev/null
+++ b/sound/xen/xen_snd_front_alsa.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <[email protected]>
+ */
+
+#ifndef __XEN_SND_FRONT_ALSA_H
+#define __XEN_SND_FRONT_ALSA_H
+
+struct xen_snd_front_info;
+
+int xen_snd_front_alsa_init(struct xen_snd_front_info *front_info);
+
+void xen_snd_front_alsa_fini(struct xen_snd_front_info *front_info);
+
+void xen_snd_front_alsa_handle_cur_pos(struct xen_snd_front_evtchnl *evtchnl,
+ u64 pos_bytes);
+
+#endif /* __XEN_SND_FRONT_ALSA_H */
diff --git a/sound/xen/xen_snd_front_evtchnl.c b/sound/xen/xen_snd_front_evtchnl.c
index 1faafff08807..d70a62e7f910 100644
--- a/sound/xen/xen_snd_front_evtchnl.c
+++ b/sound/xen/xen_snd_front_evtchnl.c
@@ -14,6 +14,7 @@
#include <xen/xenbus.h>

#include "xen_snd_front.h"
+#include "xen_snd_front_alsa.h"
#include "xen_snd_front_cfg.h"
#include "xen_snd_front_evtchnl.h"

@@ -118,7 +119,8 @@ static irqreturn_t evtchnl_interrupt_evt(int irq, void *dev_id)

switch (event->type) {
case XENSND_EVT_CUR_POS:
- /* Do nothing at the moment. */
+ xen_snd_front_alsa_handle_cur_pos(channel,
+ event->op.cur_pos.position);
break;
}
}
--
2.17.0


2018-05-14 06:29:32

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: [PATCH v3 3/6] ALSA: xen-front: Implement Xen event channel handling

From: Oleksandr Andrushchenko <[email protected]>

Handle Xen event channels:
- create for all configured streams and publish
corresponding ring references and event channels in Xen store,
so backend can connect
- implement event channels interrupt handlers
- create and destroy event channels with respect to Xen bus state

Signed-off-by: Oleksandr Andrushchenko <[email protected]>
---
sound/xen/Makefile | 3 +-
sound/xen/xen_snd_front.c | 9 +-
sound/xen/xen_snd_front.h | 5 +
sound/xen/xen_snd_front_evtchnl.c | 494 ++++++++++++++++++++++++++++++
sound/xen/xen_snd_front_evtchnl.h | 95 ++++++
5 files changed, 604 insertions(+), 2 deletions(-)
create mode 100644 sound/xen/xen_snd_front_evtchnl.c
create mode 100644 sound/xen/xen_snd_front_evtchnl.h

diff --git a/sound/xen/Makefile b/sound/xen/Makefile
index 06705bef61fa..03c669984000 100644
--- a/sound/xen/Makefile
+++ b/sound/xen/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0 OR MIT

snd_xen_front-objs := xen_snd_front.o \
- xen_snd_front_cfg.o
+ xen_snd_front_cfg.o \
+ xen_snd_front_evtchnl.o

obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o
diff --git a/sound/xen/xen_snd_front.c b/sound/xen/xen_snd_front.c
index 70fa91683c71..277214d4fd0a 100644
--- a/sound/xen/xen_snd_front.c
+++ b/sound/xen/xen_snd_front.c
@@ -18,9 +18,11 @@
#include <xen/interface/io/sndif.h>

#include "xen_snd_front.h"
+#include "xen_snd_front_evtchnl.h"

static void xen_snd_drv_fini(struct xen_snd_front_info *front_info)
{
+ xen_snd_front_evtchnl_free_all(front_info);
}

static int sndback_initwait(struct xen_snd_front_info *front_info)
@@ -32,7 +34,12 @@ static int sndback_initwait(struct xen_snd_front_info *front_info)
if (ret < 0)
return ret;

- return 0;
+ /* create event channels for all streams and publish */
+ ret = xen_snd_front_evtchnl_create_all(front_info, num_streams);
+ if (ret < 0)
+ return ret;
+
+ return xen_snd_front_evtchnl_publish_all(front_info);
}

static int sndback_connect(struct xen_snd_front_info *front_info)
diff --git a/sound/xen/xen_snd_front.h b/sound/xen/xen_snd_front.h
index b52226cb30bc..9d0c92100c7b 100644
--- a/sound/xen/xen_snd_front.h
+++ b/sound/xen/xen_snd_front.h
@@ -13,9 +13,14 @@

#include "xen_snd_front_cfg.h"

+struct xen_snd_front_evtchnl_pair;
+
struct xen_snd_front_info {
struct xenbus_device *xb_dev;

+ int num_evt_pairs;
+ struct xen_snd_front_evtchnl_pair *evt_pairs;
+
struct xen_front_cfg_card cfg;
};

diff --git a/sound/xen/xen_snd_front_evtchnl.c b/sound/xen/xen_snd_front_evtchnl.c
new file mode 100644
index 000000000000..1faafff08807
--- /dev/null
+++ b/sound/xen/xen_snd_front_evtchnl.c
@@ -0,0 +1,494 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <[email protected]>
+ */
+
+#include <xen/events.h>
+#include <xen/grant_table.h>
+#include <xen/xen.h>
+#include <xen/xenbus.h>
+
+#include "xen_snd_front.h"
+#include "xen_snd_front_cfg.h"
+#include "xen_snd_front_evtchnl.h"
+
+static irqreturn_t evtchnl_interrupt_req(int irq, void *dev_id)
+{
+ struct xen_snd_front_evtchnl *channel = dev_id;
+ struct xen_snd_front_info *front_info = channel->front_info;
+ struct xensnd_resp *resp;
+ RING_IDX i, rp;
+
+ if (unlikely(channel->state != EVTCHNL_STATE_CONNECTED))
+ return IRQ_HANDLED;
+
+ mutex_lock(&channel->ring_io_lock);
+
+again:
+ rp = channel->u.req.ring.sring->rsp_prod;
+ /* Ensure we see queued responses up to rp. */
+ rmb();
+
+ /*
+ * Assume that the backend is trusted to always write sane values
+ * to the ring counters, so no overflow checks on frontend side
+ * are required.
+ */
+ for (i = channel->u.req.ring.rsp_cons; i != rp; i++) {
+ resp = RING_GET_RESPONSE(&channel->u.req.ring, i);
+ if (resp->id != channel->evt_id)
+ continue;
+ switch (resp->operation) {
+ case XENSND_OP_OPEN:
+ /* fall through */
+ case XENSND_OP_CLOSE:
+ /* fall through */
+ case XENSND_OP_READ:
+ /* fall through */
+ case XENSND_OP_WRITE:
+ /* fall through */
+ case XENSND_OP_TRIGGER:
+ channel->u.req.resp_status = resp->status;
+ complete(&channel->u.req.completion);
+ break;
+ case XENSND_OP_HW_PARAM_QUERY:
+ channel->u.req.resp_status = resp->status;
+ channel->u.req.resp.hw_param =
+ resp->resp.hw_param;
+ complete(&channel->u.req.completion);
+ break;
+
+ default:
+ dev_err(&front_info->xb_dev->dev,
+ "Operation %d is not supported\n",
+ resp->operation);
+ break;
+ }
+ }
+
+ channel->u.req.ring.rsp_cons = i;
+ if (i != channel->u.req.ring.req_prod_pvt) {
+ int more_to_do;
+
+ RING_FINAL_CHECK_FOR_RESPONSES(&channel->u.req.ring,
+ more_to_do);
+ if (more_to_do)
+ goto again;
+ } else {
+ channel->u.req.ring.sring->rsp_event = i + 1;
+ }
+
+ mutex_unlock(&channel->ring_io_lock);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t evtchnl_interrupt_evt(int irq, void *dev_id)
+{
+ struct xen_snd_front_evtchnl *channel = dev_id;
+ struct xensnd_event_page *page = channel->u.evt.page;
+ u32 cons, prod;
+
+ if (unlikely(channel->state != EVTCHNL_STATE_CONNECTED))
+ return IRQ_HANDLED;
+
+ mutex_lock(&channel->ring_io_lock);
+
+ prod = page->in_prod;
+ /* Ensure we see ring contents up to prod. */
+ virt_rmb();
+ if (prod == page->in_cons)
+ goto out;
+
+ /*
+ * Assume that the backend is trusted to always write sane values
+ * to the ring counters, so no overflow checks on frontend side
+ * are required.
+ */
+ for (cons = page->in_cons; cons != prod; cons++) {
+ struct xensnd_evt *event;
+
+ event = &XENSND_IN_RING_REF(page, cons);
+ if (unlikely(event->id != channel->evt_id++))
+ continue;
+
+ switch (event->type) {
+ case XENSND_EVT_CUR_POS:
+ /* Do nothing at the moment. */
+ break;
+ }
+ }
+
+ page->in_cons = cons;
+ /* Ensure ring contents. */
+ virt_wmb();
+
+out:
+ mutex_unlock(&channel->ring_io_lock);
+ return IRQ_HANDLED;
+}
+
+void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *channel)
+{
+ int notify;
+
+ channel->u.req.ring.req_prod_pvt++;
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&channel->u.req.ring, notify);
+ if (notify)
+ notify_remote_via_irq(channel->irq);
+}
+
+static void evtchnl_free(struct xen_snd_front_info *front_info,
+ struct xen_snd_front_evtchnl *channel)
+{
+ unsigned long page = 0;
+
+ if (channel->type == EVTCHNL_TYPE_REQ)
+ page = (unsigned long)channel->u.req.ring.sring;
+ else if (channel->type == EVTCHNL_TYPE_EVT)
+ page = (unsigned long)channel->u.evt.page;
+
+ if (!page)
+ return;
+
+ channel->state = EVTCHNL_STATE_DISCONNECTED;
+ if (channel->type == EVTCHNL_TYPE_REQ) {
+ /* Release all who still waits for response if any. */
+ channel->u.req.resp_status = -EIO;
+ complete_all(&channel->u.req.completion);
+ }
+
+ if (channel->irq)
+ unbind_from_irqhandler(channel->irq, channel);
+
+ if (channel->port)
+ xenbus_free_evtchn(front_info->xb_dev, channel->port);
+
+ /* End access and free the page. */
+ if (channel->gref != GRANT_INVALID_REF)
+ gnttab_end_foreign_access(channel->gref, 0, page);
+ else
+ free_page(page);
+
+ memset(channel, 0, sizeof(*channel));
+}
+
+void xen_snd_front_evtchnl_free_all(struct xen_snd_front_info *front_info)
+{
+ int i;
+
+ if (!front_info->evt_pairs)
+ return;
+
+ for (i = 0; i < front_info->num_evt_pairs; i++) {
+ evtchnl_free(front_info, &front_info->evt_pairs[i].req);
+ evtchnl_free(front_info, &front_info->evt_pairs[i].evt);
+ }
+
+ kfree(front_info->evt_pairs);
+ front_info->evt_pairs = NULL;
+}
+
+static int evtchnl_alloc(struct xen_snd_front_info *front_info, int index,
+ struct xen_snd_front_evtchnl *channel,
+ enum xen_snd_front_evtchnl_type type)
+{
+ struct xenbus_device *xb_dev = front_info->xb_dev;
+ unsigned long page;
+ grant_ref_t gref;
+ irq_handler_t handler;
+ char *handler_name = NULL;
+ int ret;
+
+ memset(channel, 0, sizeof(*channel));
+ channel->type = type;
+ channel->index = index;
+ channel->front_info = front_info;
+ channel->state = EVTCHNL_STATE_DISCONNECTED;
+ channel->gref = GRANT_INVALID_REF;
+ page = get_zeroed_page(GFP_KERNEL);
+ if (!page) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ handler_name = kasprintf(GFP_KERNEL, "%s-%s", XENSND_DRIVER_NAME,
+ type == EVTCHNL_TYPE_REQ ?
+ XENSND_FIELD_RING_REF :
+ XENSND_FIELD_EVT_RING_REF);
+ if (!handler_name) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ mutex_init(&channel->ring_io_lock);
+
+ if (type == EVTCHNL_TYPE_REQ) {
+ struct xen_sndif_sring *sring = (struct xen_sndif_sring *)page;
+
+ init_completion(&channel->u.req.completion);
+ mutex_init(&channel->u.req.req_io_lock);
+ SHARED_RING_INIT(sring);
+ FRONT_RING_INIT(&channel->u.req.ring, sring, XEN_PAGE_SIZE);
+
+ ret = xenbus_grant_ring(xb_dev, sring, 1, &gref);
+ if (ret < 0) {
+ channel->u.req.ring.sring = NULL;
+ goto fail;
+ }
+
+ handler = evtchnl_interrupt_req;
+ } else {
+ ret = gnttab_grant_foreign_access(xb_dev->otherend_id,
+ virt_to_gfn((void *)page), 0);
+ if (ret < 0)
+ goto fail;
+
+ channel->u.evt.page = (struct xensnd_event_page *)page;
+ gref = ret;
+ handler = evtchnl_interrupt_evt;
+ }
+
+ channel->gref = gref;
+
+ ret = xenbus_alloc_evtchn(xb_dev, &channel->port);
+ if (ret < 0)
+ goto fail;
+
+ ret = bind_evtchn_to_irq(channel->port);
+ if (ret < 0) {
+ dev_err(&xb_dev->dev,
+ "Failed to bind IRQ for domid %d port %d: %d\n",
+ front_info->xb_dev->otherend_id, channel->port, ret);
+ goto fail;
+ }
+
+ channel->irq = ret;
+
+ ret = request_threaded_irq(channel->irq, NULL, handler,
+ IRQF_ONESHOT, handler_name, channel);
+ if (ret < 0) {
+ dev_err(&xb_dev->dev, "Failed to request IRQ %d: %d\n",
+ channel->irq, ret);
+ goto fail;
+ }
+
+ kfree(handler_name);
+ return 0;
+
+fail:
+ if (page)
+ free_page(page);
+ kfree(handler_name);
+ dev_err(&xb_dev->dev, "Failed to allocate ring: %d\n", ret);
+ return ret;
+}
+
+int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info,
+ int num_streams)
+{
+ struct xen_front_cfg_card *cfg = &front_info->cfg;
+ struct device *dev = &front_info->xb_dev->dev;
+ int d, ret = 0;
+
+ front_info->evt_pairs =
+ kcalloc(num_streams,
+ sizeof(struct xen_snd_front_evtchnl_pair),
+ GFP_KERNEL);
+ if (!front_info->evt_pairs)
+ return -ENOMEM;
+
+ /* Iterate over devices and their streams and create event channels. */
+ for (d = 0; d < cfg->num_pcm_instances; d++) {
+ struct xen_front_cfg_pcm_instance *pcm_instance;
+ int s, index;
+
+ pcm_instance = &cfg->pcm_instances[d];
+
+ for (s = 0; s < pcm_instance->num_streams_pb; s++) {
+ index = pcm_instance->streams_pb[s].index;
+
+ ret = evtchnl_alloc(front_info, index,
+ &front_info->evt_pairs[index].req,
+ EVTCHNL_TYPE_REQ);
+ if (ret < 0) {
+ dev_err(dev, "Error allocating control channel\n");
+ goto fail;
+ }
+
+ ret = evtchnl_alloc(front_info, index,
+ &front_info->evt_pairs[index].evt,
+ EVTCHNL_TYPE_EVT);
+ if (ret < 0) {
+ dev_err(dev, "Error allocating in-event channel\n");
+ goto fail;
+ }
+ }
+
+ for (s = 0; s < pcm_instance->num_streams_cap; s++) {
+ index = pcm_instance->streams_cap[s].index;
+
+ ret = evtchnl_alloc(front_info, index,
+ &front_info->evt_pairs[index].req,
+ EVTCHNL_TYPE_REQ);
+ if (ret < 0) {
+ dev_err(dev, "Error allocating control channel\n");
+ goto fail;
+ }
+
+ ret = evtchnl_alloc(front_info, index,
+ &front_info->evt_pairs[index].evt,
+ EVTCHNL_TYPE_EVT);
+ if (ret < 0) {
+ dev_err(dev, "Error allocating in-event channel\n");
+ goto fail;
+ }
+ }
+ }
+ if (ret < 0)
+ goto fail;
+
+ front_info->num_evt_pairs = num_streams;
+ return 0;
+
+fail:
+ xen_snd_front_evtchnl_free_all(front_info);
+ return ret;
+}
+
+static int evtchnl_publish(struct xenbus_transaction xbt,
+ struct xen_snd_front_evtchnl *channel,
+ const char *path, const char *node_ring,
+ const char *node_chnl)
+{
+ struct xenbus_device *xb_dev = channel->front_info->xb_dev;
+ int ret;
+
+ /* Write control channel ring reference. */
+ ret = xenbus_printf(xbt, path, node_ring, "%u", channel->gref);
+ if (ret < 0) {
+ dev_err(&xb_dev->dev, "Error writing ring-ref: %d\n", ret);
+ return ret;
+ }
+
+ /* Write event channel ring reference. */
+ ret = xenbus_printf(xbt, path, node_chnl, "%u", channel->port);
+ if (ret < 0) {
+ dev_err(&xb_dev->dev, "Error writing event channel: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+int xen_snd_front_evtchnl_publish_all(struct xen_snd_front_info *front_info)
+{
+ struct xen_front_cfg_card *cfg = &front_info->cfg;
+ struct xenbus_transaction xbt;
+ int ret, d;
+
+again:
+ ret = xenbus_transaction_start(&xbt);
+ if (ret < 0) {
+ xenbus_dev_fatal(front_info->xb_dev, ret,
+ "starting transaction");
+ return ret;
+ }
+
+ for (d = 0; d < cfg->num_pcm_instances; d++) {
+ struct xen_front_cfg_pcm_instance *pcm_instance;
+ int s, index;
+
+ pcm_instance = &cfg->pcm_instances[d];
+
+ for (s = 0; s < pcm_instance->num_streams_pb; s++) {
+ index = pcm_instance->streams_pb[s].index;
+
+ ret = evtchnl_publish(xbt,
+ &front_info->evt_pairs[index].req,
+ pcm_instance->streams_pb[s].xenstore_path,
+ XENSND_FIELD_RING_REF,
+ XENSND_FIELD_EVT_CHNL);
+ if (ret < 0)
+ goto fail;
+
+ ret = evtchnl_publish(xbt,
+ &front_info->evt_pairs[index].evt,
+ pcm_instance->streams_pb[s].xenstore_path,
+ XENSND_FIELD_EVT_RING_REF,
+ XENSND_FIELD_EVT_EVT_CHNL);
+ if (ret < 0)
+ goto fail;
+ }
+
+ for (s = 0; s < pcm_instance->num_streams_cap; s++) {
+ index = pcm_instance->streams_cap[s].index;
+
+ ret = evtchnl_publish(xbt,
+ &front_info->evt_pairs[index].req,
+ pcm_instance->streams_cap[s].xenstore_path,
+ XENSND_FIELD_RING_REF,
+ XENSND_FIELD_EVT_CHNL);
+ if (ret < 0)
+ goto fail;
+
+ ret = evtchnl_publish(xbt,
+ &front_info->evt_pairs[index].evt,
+ pcm_instance->streams_cap[s].xenstore_path,
+ XENSND_FIELD_EVT_RING_REF,
+ XENSND_FIELD_EVT_EVT_CHNL);
+ if (ret < 0)
+ goto fail;
+ }
+ }
+ ret = xenbus_transaction_end(xbt, 0);
+ if (ret < 0) {
+ if (ret == -EAGAIN)
+ goto again;
+
+ xenbus_dev_fatal(front_info->xb_dev, ret,
+ "completing transaction");
+ goto fail_to_end;
+ }
+ return 0;
+fail:
+ xenbus_transaction_end(xbt, 1);
+fail_to_end:
+ xenbus_dev_fatal(front_info->xb_dev, ret, "writing XenStore");
+ return ret;
+}
+
+void xen_snd_front_evtchnl_pair_set_connected(struct xen_snd_front_evtchnl_pair *evt_pair,
+ bool is_connected)
+{
+ enum xen_snd_front_evtchnl_state state;
+
+ if (is_connected)
+ state = EVTCHNL_STATE_CONNECTED;
+ else
+ state = EVTCHNL_STATE_DISCONNECTED;
+
+ mutex_lock(&evt_pair->req.ring_io_lock);
+ evt_pair->req.state = state;
+ mutex_unlock(&evt_pair->req.ring_io_lock);
+
+ mutex_lock(&evt_pair->evt.ring_io_lock);
+ evt_pair->evt.state = state;
+ mutex_unlock(&evt_pair->evt.ring_io_lock);
+}
+
+void xen_snd_front_evtchnl_pair_clear(struct xen_snd_front_evtchnl_pair *evt_pair)
+{
+ mutex_lock(&evt_pair->req.ring_io_lock);
+ evt_pair->req.evt_next_id = 0;
+ mutex_unlock(&evt_pair->req.ring_io_lock);
+
+ mutex_lock(&evt_pair->evt.ring_io_lock);
+ evt_pair->evt.evt_next_id = 0;
+ mutex_unlock(&evt_pair->evt.ring_io_lock);
+}
+
diff --git a/sound/xen/xen_snd_front_evtchnl.h b/sound/xen/xen_snd_front_evtchnl.h
new file mode 100644
index 000000000000..cbe51fd1ec15
--- /dev/null
+++ b/sound/xen/xen_snd_front_evtchnl.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <[email protected]>
+ */
+
+#ifndef __XEN_SND_FRONT_EVTCHNL_H
+#define __XEN_SND_FRONT_EVTCHNL_H
+
+#include <xen/interface/io/sndif.h>
+
+struct xen_snd_front_info;
+
+#ifndef GRANT_INVALID_REF
+/*
+ * FIXME: usage of grant reference 0 as invalid grant reference:
+ * grant reference 0 is valid, but never exposed to a PV driver,
+ * because of the fact it is already in use/reserved by the PV console.
+ */
+#define GRANT_INVALID_REF 0
+#endif
+
+/* Timeout in ms to wait for backend to respond. */
+#define VSND_WAIT_BACK_MS 3000
+
+enum xen_snd_front_evtchnl_state {
+ EVTCHNL_STATE_DISCONNECTED,
+ EVTCHNL_STATE_CONNECTED,
+};
+
+enum xen_snd_front_evtchnl_type {
+ EVTCHNL_TYPE_REQ,
+ EVTCHNL_TYPE_EVT,
+};
+
+struct xen_snd_front_evtchnl {
+ struct xen_snd_front_info *front_info;
+ int gref;
+ int port;
+ int irq;
+ int index;
+ /* State of the event channel. */
+ enum xen_snd_front_evtchnl_state state;
+ enum xen_snd_front_evtchnl_type type;
+ /* Either response id or incoming event id. */
+ u16 evt_id;
+ /* Next request id or next expected event id. */
+ u16 evt_next_id;
+ /* Shared ring access lock. */
+ struct mutex ring_io_lock;
+ union {
+ struct {
+ struct xen_sndif_front_ring ring;
+ struct completion completion;
+ /* Serializer for backend IO: request/response. */
+ struct mutex req_io_lock;
+
+ /* Latest response status. */
+ int resp_status;
+ union {
+ struct xensnd_query_hw_param hw_param;
+ } resp;
+ } req;
+ struct {
+ struct xensnd_event_page *page;
+ /* This is needed to handle XENSND_EVT_CUR_POS event. */
+ struct snd_pcm_substream *substream;
+ } evt;
+ } u;
+};
+
+struct xen_snd_front_evtchnl_pair {
+ struct xen_snd_front_evtchnl req;
+ struct xen_snd_front_evtchnl evt;
+};
+
+int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info,
+ int num_streams);
+
+void xen_snd_front_evtchnl_free_all(struct xen_snd_front_info *front_info);
+
+int xen_snd_front_evtchnl_publish_all(struct xen_snd_front_info *front_info);
+
+void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *evtchnl);
+
+void xen_snd_front_evtchnl_pair_set_connected(struct xen_snd_front_evtchnl_pair *evt_pair,
+ bool is_connected);
+
+void xen_snd_front_evtchnl_pair_clear(struct xen_snd_front_evtchnl_pair *evt_pair);
+
+#endif /* __XEN_SND_FRONT_EVTCHNL_H */
--
2.17.0


2018-05-14 06:30:10

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: [PATCH v3 2/6] ALSA: xen-front: Read sound driver configuration from Xen store

From: Oleksandr Andrushchenko <[email protected]>

Read configuration values from Xen store according
to xen/interface/io/sndif.h protocol:
- introduce configuration structures for different
components, e.g. sound card, device, stream
- read PCM HW parameters, e.g rate, format etc.
- detect stream type (capture/playback)
- read device and card parameters

Signed-off-by: Oleksandr Andrushchenko <[email protected]>
---
sound/xen/Makefile | 3 +-
sound/xen/xen_snd_front.c | 7 +
sound/xen/xen_snd_front.h | 4 +
sound/xen/xen_snd_front_cfg.c | 517 ++++++++++++++++++++++++++++++++++
sound/xen/xen_snd_front_cfg.h | 46 +++
5 files changed, 576 insertions(+), 1 deletion(-)
create mode 100644 sound/xen/xen_snd_front_cfg.c
create mode 100644 sound/xen/xen_snd_front_cfg.h

diff --git a/sound/xen/Makefile b/sound/xen/Makefile
index 4507ef3c27fd..06705bef61fa 100644
--- a/sound/xen/Makefile
+++ b/sound/xen/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0 OR MIT

-snd_xen_front-objs := xen_snd_front.o
+snd_xen_front-objs := xen_snd_front.o \
+ xen_snd_front_cfg.o

obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o
diff --git a/sound/xen/xen_snd_front.c b/sound/xen/xen_snd_front.c
index bbbe2767b565..70fa91683c71 100644
--- a/sound/xen/xen_snd_front.c
+++ b/sound/xen/xen_snd_front.c
@@ -25,6 +25,13 @@ static void xen_snd_drv_fini(struct xen_snd_front_info *front_info)

static int sndback_initwait(struct xen_snd_front_info *front_info)
{
+ int num_streams;
+ int ret;
+
+ ret = xen_snd_front_cfg_card(front_info, &num_streams);
+ if (ret < 0)
+ return ret;
+
return 0;
}

diff --git a/sound/xen/xen_snd_front.h b/sound/xen/xen_snd_front.h
index 4ae204b23d32..b52226cb30bc 100644
--- a/sound/xen/xen_snd_front.h
+++ b/sound/xen/xen_snd_front.h
@@ -11,8 +11,12 @@
#ifndef __XEN_SND_FRONT_H
#define __XEN_SND_FRONT_H

+#include "xen_snd_front_cfg.h"
+
struct xen_snd_front_info {
struct xenbus_device *xb_dev;
+
+ struct xen_front_cfg_card cfg;
};

#endif /* __XEN_SND_FRONT_H */
diff --git a/sound/xen/xen_snd_front_cfg.c b/sound/xen/xen_snd_front_cfg.c
new file mode 100644
index 000000000000..38c7e1eefbb9
--- /dev/null
+++ b/sound/xen/xen_snd_front_cfg.c
@@ -0,0 +1,517 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <[email protected]>
+ */
+
+#include <xen/xenbus.h>
+
+#include <xen/interface/io/sndif.h>
+
+#include "xen_snd_front.h"
+#include "xen_snd_front_cfg.h"
+
+/* Maximum number of supported streams. */
+#define VSND_MAX_STREAM 8
+
+struct cfg_hw_sample_rate {
+ const char *name;
+ unsigned int mask;
+ unsigned int value;
+};
+
+static const struct cfg_hw_sample_rate CFG_HW_SUPPORTED_RATES[] = {
+ { .name = "5512", .mask = SNDRV_PCM_RATE_5512, .value = 5512 },
+ { .name = "8000", .mask = SNDRV_PCM_RATE_8000, .value = 8000 },
+ { .name = "11025", .mask = SNDRV_PCM_RATE_11025, .value = 11025 },
+ { .name = "16000", .mask = SNDRV_PCM_RATE_16000, .value = 16000 },
+ { .name = "22050", .mask = SNDRV_PCM_RATE_22050, .value = 22050 },
+ { .name = "32000", .mask = SNDRV_PCM_RATE_32000, .value = 32000 },
+ { .name = "44100", .mask = SNDRV_PCM_RATE_44100, .value = 44100 },
+ { .name = "48000", .mask = SNDRV_PCM_RATE_48000, .value = 48000 },
+ { .name = "64000", .mask = SNDRV_PCM_RATE_64000, .value = 64000 },
+ { .name = "96000", .mask = SNDRV_PCM_RATE_96000, .value = 96000 },
+ { .name = "176400", .mask = SNDRV_PCM_RATE_176400, .value = 176400 },
+ { .name = "192000", .mask = SNDRV_PCM_RATE_192000, .value = 192000 },
+};
+
+struct cfg_hw_sample_format {
+ const char *name;
+ u64 mask;
+};
+
+static const struct cfg_hw_sample_format CFG_HW_SUPPORTED_FORMATS[] = {
+ {
+ .name = XENSND_PCM_FORMAT_U8_STR,
+ .mask = SNDRV_PCM_FMTBIT_U8
+ },
+ {
+ .name = XENSND_PCM_FORMAT_S8_STR,
+ .mask = SNDRV_PCM_FMTBIT_S8
+ },
+ {
+ .name = XENSND_PCM_FORMAT_U16_LE_STR,
+ .mask = SNDRV_PCM_FMTBIT_U16_LE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_U16_BE_STR,
+ .mask = SNDRV_PCM_FMTBIT_U16_BE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_S16_LE_STR,
+ .mask = SNDRV_PCM_FMTBIT_S16_LE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_S16_BE_STR,
+ .mask = SNDRV_PCM_FMTBIT_S16_BE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_U24_LE_STR,
+ .mask = SNDRV_PCM_FMTBIT_U24_LE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_U24_BE_STR,
+ .mask = SNDRV_PCM_FMTBIT_U24_BE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_S24_LE_STR,
+ .mask = SNDRV_PCM_FMTBIT_S24_LE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_S24_BE_STR,
+ .mask = SNDRV_PCM_FMTBIT_S24_BE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_U32_LE_STR,
+ .mask = SNDRV_PCM_FMTBIT_U32_LE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_U32_BE_STR,
+ .mask = SNDRV_PCM_FMTBIT_U32_BE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_S32_LE_STR,
+ .mask = SNDRV_PCM_FMTBIT_S32_LE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_S32_BE_STR,
+ .mask = SNDRV_PCM_FMTBIT_S32_BE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_A_LAW_STR,
+ .mask = SNDRV_PCM_FMTBIT_A_LAW
+ },
+ {
+ .name = XENSND_PCM_FORMAT_MU_LAW_STR,
+ .mask = SNDRV_PCM_FMTBIT_MU_LAW
+ },
+ {
+ .name = XENSND_PCM_FORMAT_F32_LE_STR,
+ .mask = SNDRV_PCM_FMTBIT_FLOAT_LE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_F32_BE_STR,
+ .mask = SNDRV_PCM_FMTBIT_FLOAT_BE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_F64_LE_STR,
+ .mask = SNDRV_PCM_FMTBIT_FLOAT64_LE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_F64_BE_STR,
+ .mask = SNDRV_PCM_FMTBIT_FLOAT64_BE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE_STR,
+ .mask = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE_STR,
+ .mask = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_BE
+ },
+ {
+ .name = XENSND_PCM_FORMAT_IMA_ADPCM_STR,
+ .mask = SNDRV_PCM_FMTBIT_IMA_ADPCM
+ },
+ {
+ .name = XENSND_PCM_FORMAT_MPEG_STR,
+ .mask = SNDRV_PCM_FMTBIT_MPEG
+ },
+ {
+ .name = XENSND_PCM_FORMAT_GSM_STR,
+ .mask = SNDRV_PCM_FMTBIT_GSM
+ },
+};
+
+static void cfg_hw_rates(char *list, unsigned int len,
+ const char *path, struct snd_pcm_hardware *pcm_hw)
+{
+ char *cur_rate;
+ unsigned int cur_mask;
+ unsigned int cur_value;
+ unsigned int rates;
+ unsigned int rate_min;
+ unsigned int rate_max;
+ int i;
+
+ rates = 0;
+ rate_min = -1;
+ rate_max = 0;
+ while ((cur_rate = strsep(&list, XENSND_LIST_SEPARATOR))) {
+ for (i = 0; i < ARRAY_SIZE(CFG_HW_SUPPORTED_RATES); i++)
+ if (!strncasecmp(cur_rate,
+ CFG_HW_SUPPORTED_RATES[i].name,
+ XENSND_SAMPLE_RATE_MAX_LEN)) {
+ cur_mask = CFG_HW_SUPPORTED_RATES[i].mask;
+ cur_value = CFG_HW_SUPPORTED_RATES[i].value;
+ rates |= cur_mask;
+ if (rate_min > cur_value)
+ rate_min = cur_value;
+ if (rate_max < cur_value)
+ rate_max = cur_value;
+ }
+ }
+
+ if (rates) {
+ pcm_hw->rates = rates;
+ pcm_hw->rate_min = rate_min;
+ pcm_hw->rate_max = rate_max;
+ }
+}
+
+static void cfg_formats(char *list, unsigned int len,
+ const char *path, struct snd_pcm_hardware *pcm_hw)
+{
+ u64 formats;
+ char *cur_format;
+ int i;
+
+ formats = 0;
+ while ((cur_format = strsep(&list, XENSND_LIST_SEPARATOR))) {
+ for (i = 0; i < ARRAY_SIZE(CFG_HW_SUPPORTED_FORMATS); i++)
+ if (!strncasecmp(cur_format,
+ CFG_HW_SUPPORTED_FORMATS[i].name,
+ XENSND_SAMPLE_FORMAT_MAX_LEN))
+ formats |= CFG_HW_SUPPORTED_FORMATS[i].mask;
+ }
+
+ if (formats)
+ pcm_hw->formats = formats;
+}
+
+#define MAX_BUFFER_SIZE (64 * 1024)
+#define MIN_PERIOD_SIZE 64
+#define MAX_PERIOD_SIZE MAX_BUFFER_SIZE
+#define USE_FORMATS (SNDRV_PCM_FMTBIT_U8 | \
+ SNDRV_PCM_FMTBIT_S16_LE)
+#define USE_RATE (SNDRV_PCM_RATE_CONTINUOUS | \
+ SNDRV_PCM_RATE_8000_48000)
+#define USE_RATE_MIN 5512
+#define USE_RATE_MAX 48000
+#define USE_CHANNELS_MIN 1
+#define USE_CHANNELS_MAX 2
+#define USE_PERIODS_MIN 2
+#define USE_PERIODS_MAX (MAX_BUFFER_SIZE / MIN_PERIOD_SIZE)
+
+static const struct snd_pcm_hardware SND_DRV_PCM_HW_DEFAULT = {
+ .info = (SNDRV_PCM_INFO_MMAP |
+ SNDRV_PCM_INFO_INTERLEAVED |
+ SNDRV_PCM_INFO_RESUME |
+ SNDRV_PCM_INFO_MMAP_VALID),
+ .formats = USE_FORMATS,
+ .rates = USE_RATE,
+ .rate_min = USE_RATE_MIN,
+ .rate_max = USE_RATE_MAX,
+ .channels_min = USE_CHANNELS_MIN,
+ .channels_max = USE_CHANNELS_MAX,
+ .buffer_bytes_max = MAX_BUFFER_SIZE,
+ .period_bytes_min = MIN_PERIOD_SIZE,
+ .period_bytes_max = MAX_PERIOD_SIZE,
+ .periods_min = USE_PERIODS_MIN,
+ .periods_max = USE_PERIODS_MAX,
+ .fifo_size = 0,
+};
+
+static void cfg_read_pcm_hw(const char *path,
+ struct snd_pcm_hardware *parent_pcm_hw,
+ struct snd_pcm_hardware *pcm_hw)
+{
+ char *list;
+ int val;
+ size_t buf_sz;
+ unsigned int len;
+
+ /* Inherit parent's PCM HW and read overrides from XenStore. */
+ if (parent_pcm_hw)
+ *pcm_hw = *parent_pcm_hw;
+ else
+ *pcm_hw = SND_DRV_PCM_HW_DEFAULT;
+
+ val = xenbus_read_unsigned(path, XENSND_FIELD_CHANNELS_MIN, 0);
+ if (val)
+ pcm_hw->channels_min = val;
+
+ val = xenbus_read_unsigned(path, XENSND_FIELD_CHANNELS_MAX, 0);
+ if (val)
+ pcm_hw->channels_max = val;
+
+ list = xenbus_read(XBT_NIL, path, XENSND_FIELD_SAMPLE_RATES, &len);
+ if (!IS_ERR(list)) {
+ cfg_hw_rates(list, len, path, pcm_hw);
+ kfree(list);
+ }
+
+ list = xenbus_read(XBT_NIL, path, XENSND_FIELD_SAMPLE_FORMATS, &len);
+ if (!IS_ERR(list)) {
+ cfg_formats(list, len, path, pcm_hw);
+ kfree(list);
+ }
+
+ buf_sz = xenbus_read_unsigned(path, XENSND_FIELD_BUFFER_SIZE, 0);
+ if (buf_sz)
+ pcm_hw->buffer_bytes_max = buf_sz;
+
+ /* Update configuration to match new values. */
+ if (pcm_hw->channels_min > pcm_hw->channels_max)
+ pcm_hw->channels_min = pcm_hw->channels_max;
+
+ if (pcm_hw->rate_min > pcm_hw->rate_max)
+ pcm_hw->rate_min = pcm_hw->rate_max;
+
+ pcm_hw->period_bytes_max = pcm_hw->buffer_bytes_max;
+
+ pcm_hw->periods_max = pcm_hw->period_bytes_max /
+ pcm_hw->period_bytes_min;
+}
+
+static int cfg_get_stream_type(const char *path, int index,
+ int *num_pb, int *num_cap)
+{
+ char *str = NULL;
+ char *stream_path;
+ int ret;
+
+ *num_pb = 0;
+ *num_cap = 0;
+ stream_path = kasprintf(GFP_KERNEL, "%s/%d", path, index);
+ if (!stream_path) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ str = xenbus_read(XBT_NIL, stream_path, XENSND_FIELD_TYPE, NULL);
+ if (IS_ERR(str)) {
+ ret = PTR_ERR(str);
+ goto fail;
+ }
+
+ if (!strncasecmp(str, XENSND_STREAM_TYPE_PLAYBACK,
+ sizeof(XENSND_STREAM_TYPE_PLAYBACK))) {
+ (*num_pb)++;
+ } else if (!strncasecmp(str, XENSND_STREAM_TYPE_CAPTURE,
+ sizeof(XENSND_STREAM_TYPE_CAPTURE))) {
+ (*num_cap)++;
+ } else {
+ ret = -EINVAL;
+ goto fail;
+ }
+ ret = 0;
+
+fail:
+ kfree(stream_path);
+ kfree(str);
+ return ret;
+}
+
+static int cfg_stream(struct xen_snd_front_info *front_info,
+ struct xen_front_cfg_pcm_instance *pcm_instance,
+ const char *path, int index, int *cur_pb, int *cur_cap,
+ int *stream_cnt)
+{
+ char *str = NULL;
+ char *stream_path;
+ struct xen_front_cfg_stream *stream;
+ int ret;
+
+ stream_path = devm_kasprintf(&front_info->xb_dev->dev,
+ GFP_KERNEL, "%s/%d", path, index);
+ if (!stream_path) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ str = xenbus_read(XBT_NIL, stream_path, XENSND_FIELD_TYPE, NULL);
+ if (IS_ERR(str)) {
+ ret = PTR_ERR(str);
+ goto fail;
+ }
+
+ if (!strncasecmp(str, XENSND_STREAM_TYPE_PLAYBACK,
+ sizeof(XENSND_STREAM_TYPE_PLAYBACK))) {
+ stream = &pcm_instance->streams_pb[(*cur_pb)++];
+ } else if (!strncasecmp(str, XENSND_STREAM_TYPE_CAPTURE,
+ sizeof(XENSND_STREAM_TYPE_CAPTURE))) {
+ stream = &pcm_instance->streams_cap[(*cur_cap)++];
+ } else {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* Get next stream index. */
+ stream->index = (*stream_cnt)++;
+ stream->xenstore_path = stream_path;
+ /*
+ * Check XenStore if PCM HW configuration exists for this stream
+ * and update if so, e.g. we inherit all values from device's PCM HW,
+ * but can still override some of the values for the stream.
+ */
+ cfg_read_pcm_hw(stream->xenstore_path,
+ &pcm_instance->pcm_hw, &stream->pcm_hw);
+ ret = 0;
+
+fail:
+ kfree(str);
+ return ret;
+}
+
+static int cfg_device(struct xen_snd_front_info *front_info,
+ struct xen_front_cfg_pcm_instance *pcm_instance,
+ struct snd_pcm_hardware *parent_pcm_hw,
+ const char *path, int node_index, int *stream_cnt)
+{
+ char *str;
+ char *device_path;
+ int ret, i, num_streams;
+ int num_pb, num_cap;
+ int cur_pb, cur_cap;
+ char node[3];
+
+ device_path = kasprintf(GFP_KERNEL, "%s/%d", path, node_index);
+ if (!device_path)
+ return -ENOMEM;
+
+ str = xenbus_read(XBT_NIL, device_path, XENSND_FIELD_DEVICE_NAME, NULL);
+ if (!IS_ERR(str)) {
+ strncpy(pcm_instance->name, str, sizeof(pcm_instance->name));
+ kfree(str);
+ }
+
+ pcm_instance->device_id = node_index;
+
+ /*
+ * Check XenStore if PCM HW configuration exists for this device
+ * and update if so, e.g. we inherit all values from card's PCM HW,
+ * but can still override some of the values for the device.
+ */
+ cfg_read_pcm_hw(device_path, parent_pcm_hw, &pcm_instance->pcm_hw);
+
+ /* Find out how many streams were configured in Xen store. */
+ num_streams = 0;
+ do {
+ snprintf(node, sizeof(node), "%d", num_streams);
+ if (!xenbus_exists(XBT_NIL, device_path, node))
+ break;
+
+ num_streams++;
+ } while (num_streams < VSND_MAX_STREAM);
+
+ pcm_instance->num_streams_pb = 0;
+ pcm_instance->num_streams_cap = 0;
+ /* Get number of playback and capture streams. */
+ for (i = 0; i < num_streams; i++) {
+ ret = cfg_get_stream_type(device_path, i, &num_pb, &num_cap);
+ if (ret < 0)
+ goto fail;
+
+ pcm_instance->num_streams_pb += num_pb;
+ pcm_instance->num_streams_cap += num_cap;
+ }
+
+ if (pcm_instance->num_streams_pb) {
+ pcm_instance->streams_pb =
+ devm_kcalloc(&front_info->xb_dev->dev,
+ pcm_instance->num_streams_pb,
+ sizeof(struct xen_front_cfg_stream),
+ GFP_KERNEL);
+ if (!pcm_instance->streams_pb) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ }
+
+ if (pcm_instance->num_streams_cap) {
+ pcm_instance->streams_cap =
+ devm_kcalloc(&front_info->xb_dev->dev,
+ pcm_instance->num_streams_cap,
+ sizeof(struct xen_front_cfg_stream),
+ GFP_KERNEL);
+ if (!pcm_instance->streams_cap) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ }
+
+ cur_pb = 0;
+ cur_cap = 0;
+ for (i = 0; i < num_streams; i++) {
+ ret = cfg_stream(front_info, pcm_instance, device_path, i,
+ &cur_pb, &cur_cap, stream_cnt);
+ if (ret < 0)
+ goto fail;
+ }
+ ret = 0;
+
+fail:
+ kfree(device_path);
+ return ret;
+}
+
+int xen_snd_front_cfg_card(struct xen_snd_front_info *front_info,
+ int *stream_cnt)
+{
+ struct xenbus_device *xb_dev = front_info->xb_dev;
+ struct xen_front_cfg_card *cfg = &front_info->cfg;
+ int ret, num_devices, i;
+ char node[3];
+
+ *stream_cnt = 0;
+ num_devices = 0;
+ do {
+ snprintf(node, sizeof(node), "%d", num_devices);
+ if (!xenbus_exists(XBT_NIL, xb_dev->nodename, node))
+ break;
+
+ num_devices++;
+ } while (num_devices < SNDRV_PCM_DEVICES);
+
+ if (!num_devices) {
+ dev_warn(&xb_dev->dev,
+ "No devices configured for sound card at %s\n",
+ xb_dev->nodename);
+ return -ENODEV;
+ }
+
+ /* Start from default PCM HW configuration for the card. */
+ cfg_read_pcm_hw(xb_dev->nodename, NULL, &cfg->pcm_hw);
+
+ cfg->pcm_instances =
+ devm_kcalloc(&front_info->xb_dev->dev, num_devices,
+ sizeof(struct xen_front_cfg_pcm_instance),
+ GFP_KERNEL);
+ if (!cfg->pcm_instances)
+ return -ENOMEM;
+
+ for (i = 0; i < num_devices; i++) {
+ ret = cfg_device(front_info, &cfg->pcm_instances[i],
+ &cfg->pcm_hw, xb_dev->nodename, i, stream_cnt);
+ if (ret < 0)
+ return ret;
+ }
+ cfg->num_pcm_instances = num_devices;
+ return 0;
+}
+
diff --git a/sound/xen/xen_snd_front_cfg.h b/sound/xen/xen_snd_front_cfg.h
new file mode 100644
index 000000000000..2353fcc74889
--- /dev/null
+++ b/sound/xen/xen_snd_front_cfg.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <[email protected]>
+ */
+
+#ifndef __XEN_SND_FRONT_CFG_H
+#define __XEN_SND_FRONT_CFG_H
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+
+struct xen_snd_front_info;
+
+struct xen_front_cfg_stream {
+ int index;
+ char *xenstore_path;
+ struct snd_pcm_hardware pcm_hw;
+};
+
+struct xen_front_cfg_pcm_instance {
+ char name[80];
+ int device_id;
+ struct snd_pcm_hardware pcm_hw;
+ int num_streams_pb;
+ struct xen_front_cfg_stream *streams_pb;
+ int num_streams_cap;
+ struct xen_front_cfg_stream *streams_cap;
+};
+
+struct xen_front_cfg_card {
+ char name_short[32];
+ char name_long[80];
+ struct snd_pcm_hardware pcm_hw;
+ int num_pcm_instances;
+ struct xen_front_cfg_pcm_instance *pcm_instances;
+};
+
+int xen_snd_front_cfg_card(struct xen_snd_front_info *front_info,
+ int *stream_cnt);
+
+#endif /* __XEN_SND_FRONT_CFG_H */
--
2.17.0


2018-05-14 06:30:27

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: [PATCH v3 1/6] ALSA: xen-front: Introduce Xen para-virtualized sound frontend driver

From: Oleksandr Andrushchenko <[email protected]>

Introduce skeleton of the para-virtualized Xen sound
frontend driver.

Initial handling for Xen bus states: implement
Xen bus state machine for the frontend driver according to
the state diagram and recovery flow from sound para-virtualized
protocol: xen/interface/io/sndif.h.

Signed-off-by: Oleksandr Andrushchenko <[email protected]>
Reviewed-by: Juergen Gross <[email protected]>
---
sound/Kconfig | 2 +
sound/Makefile | 2 +-
sound/xen/Kconfig | 10 ++
sound/xen/Makefile | 5 +
sound/xen/xen_snd_front.c | 196 ++++++++++++++++++++++++++++++++++++++
sound/xen/xen_snd_front.h | 18 ++++
6 files changed, 232 insertions(+), 1 deletion(-)
create mode 100644 sound/xen/Kconfig
create mode 100644 sound/xen/Makefile
create mode 100644 sound/xen/xen_snd_front.c
create mode 100644 sound/xen/xen_snd_front.h

diff --git a/sound/Kconfig b/sound/Kconfig
index 6833db9002ec..1140e9988fc5 100644
--- a/sound/Kconfig
+++ b/sound/Kconfig
@@ -96,6 +96,8 @@ source "sound/x86/Kconfig"

source "sound/synth/Kconfig"

+source "sound/xen/Kconfig"
+
endif # SND

endif # !UML
diff --git a/sound/Makefile b/sound/Makefile
index 99d8c31262c8..797ecdcd35e2 100644
--- a/sound/Makefile
+++ b/sound/Makefile
@@ -5,7 +5,7 @@
obj-$(CONFIG_SOUND) += soundcore.o
obj-$(CONFIG_DMASOUND) += oss/dmasound/
obj-$(CONFIG_SND) += core/ i2c/ drivers/ isa/ pci/ ppc/ arm/ sh/ synth/ usb/ \
- firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/
+ firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/ xen/
obj-$(CONFIG_SND_AOA) += aoa/

# This one must be compilable even if sound is configured out
diff --git a/sound/xen/Kconfig b/sound/xen/Kconfig
new file mode 100644
index 000000000000..4f1fceea82d2
--- /dev/null
+++ b/sound/xen/Kconfig
@@ -0,0 +1,10 @@
+# ALSA Xen drivers
+
+config SND_XEN_FRONTEND
+ tristate "Xen para-virtualized sound frontend driver"
+ depends on XEN
+ select SND_PCM
+ select XEN_XENBUS_FRONTEND
+ help
+ Choose this option if you want to enable a para-virtualized
+ frontend sound driver for Xen guest OSes.
diff --git a/sound/xen/Makefile b/sound/xen/Makefile
new file mode 100644
index 000000000000..4507ef3c27fd
--- /dev/null
+++ b/sound/xen/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0 OR MIT
+
+snd_xen_front-objs := xen_snd_front.o
+
+obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o
diff --git a/sound/xen/xen_snd_front.c b/sound/xen/xen_snd_front.c
new file mode 100644
index 000000000000..bbbe2767b565
--- /dev/null
+++ b/sound/xen/xen_snd_front.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <[email protected]>
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+
+#include <xen/platform_pci.h>
+#include <xen/xen.h>
+#include <xen/xenbus.h>
+
+#include <xen/interface/io/sndif.h>
+
+#include "xen_snd_front.h"
+
+static void xen_snd_drv_fini(struct xen_snd_front_info *front_info)
+{
+}
+
+static int sndback_initwait(struct xen_snd_front_info *front_info)
+{
+ return 0;
+}
+
+static int sndback_connect(struct xen_snd_front_info *front_info)
+{
+ return 0;
+}
+
+static void sndback_disconnect(struct xen_snd_front_info *front_info)
+{
+ xen_snd_drv_fini(front_info);
+ xenbus_switch_state(front_info->xb_dev, XenbusStateInitialising);
+}
+
+static void sndback_changed(struct xenbus_device *xb_dev,
+ enum xenbus_state backend_state)
+{
+ struct xen_snd_front_info *front_info = dev_get_drvdata(&xb_dev->dev);
+ int ret;
+
+ dev_dbg(&xb_dev->dev, "Backend state is %s, front is %s\n",
+ xenbus_strstate(backend_state),
+ xenbus_strstate(xb_dev->state));
+
+ switch (backend_state) {
+ case XenbusStateReconfiguring:
+ /* fall through */
+ case XenbusStateReconfigured:
+ /* fall through */
+ case XenbusStateInitialised:
+ /* fall through */
+ break;
+
+ case XenbusStateInitialising:
+ /* Recovering after backend unexpected closure. */
+ sndback_disconnect(front_info);
+ break;
+
+ case XenbusStateInitWait:
+ /* Recovering after backend unexpected closure. */
+ sndback_disconnect(front_info);
+
+ ret = sndback_initwait(front_info);
+ if (ret < 0)
+ xenbus_dev_fatal(xb_dev, ret, "initializing frontend");
+ else
+ xenbus_switch_state(xb_dev, XenbusStateInitialised);
+ break;
+
+ case XenbusStateConnected:
+ if (xb_dev->state != XenbusStateInitialised)
+ break;
+
+ ret = sndback_connect(front_info);
+ if (ret < 0)
+ xenbus_dev_fatal(xb_dev, ret, "initializing frontend");
+ else
+ xenbus_switch_state(xb_dev, XenbusStateConnected);
+ break;
+
+ case XenbusStateClosing:
+ /*
+ * In this state backend starts freeing resources,
+ * so let it go into closed state first, so we can also
+ * remove ours.
+ */
+ break;
+
+ case XenbusStateUnknown:
+ /* fall through */
+ case XenbusStateClosed:
+ if (xb_dev->state == XenbusStateClosed)
+ break;
+
+ sndback_disconnect(front_info);
+ break;
+ }
+}
+
+static int xen_drv_probe(struct xenbus_device *xb_dev,
+ const struct xenbus_device_id *id)
+{
+ struct xen_snd_front_info *front_info;
+
+ front_info = devm_kzalloc(&xb_dev->dev,
+ sizeof(*front_info), GFP_KERNEL);
+ if (!front_info)
+ return -ENOMEM;
+
+ front_info->xb_dev = xb_dev;
+ dev_set_drvdata(&xb_dev->dev, front_info);
+
+ return xenbus_switch_state(xb_dev, XenbusStateInitialising);
+}
+
+static int xen_drv_remove(struct xenbus_device *dev)
+{
+ struct xen_snd_front_info *front_info = dev_get_drvdata(&dev->dev);
+ int to = 100;
+
+ xenbus_switch_state(dev, XenbusStateClosing);
+
+ /*
+ * On driver removal it is disconnected from XenBus,
+ * so no backend state change events come via .otherend_changed
+ * callback. This prevents us from exiting gracefully, e.g.
+ * signaling the backend to free event channels, waiting for its
+ * state to change to XenbusStateClosed and cleaning at our end.
+ * Normally when front driver removed backend will finally go into
+ * XenbusStateInitWait state.
+ *
+ * Workaround: read backend's state manually and wait with time-out.
+ */
+ while ((xenbus_read_unsigned(front_info->xb_dev->otherend, "state",
+ XenbusStateUnknown) != XenbusStateInitWait) &&
+ to--)
+ msleep(10);
+
+ if (!to) {
+ unsigned int state;
+
+ state = xenbus_read_unsigned(front_info->xb_dev->otherend,
+ "state", XenbusStateUnknown);
+ pr_err("Backend state is %s while removing driver\n",
+ xenbus_strstate(state));
+ }
+
+ xen_snd_drv_fini(front_info);
+ xenbus_frontend_closed(dev);
+ return 0;
+}
+
+static const struct xenbus_device_id xen_drv_ids[] = {
+ { XENSND_DRIVER_NAME },
+ { "" }
+};
+
+static struct xenbus_driver xen_driver = {
+ .ids = xen_drv_ids,
+ .probe = xen_drv_probe,
+ .remove = xen_drv_remove,
+ .otherend_changed = sndback_changed,
+};
+
+static int __init xen_drv_init(void)
+{
+ if (!xen_domain())
+ return -ENODEV;
+
+ if (!xen_has_pv_devices())
+ return -ENODEV;
+
+ pr_info("Initialising Xen " XENSND_DRIVER_NAME " frontend driver\n");
+ return xenbus_register_frontend(&xen_driver);
+}
+
+static void __exit xen_drv_fini(void)
+{
+ pr_info("Unregistering Xen " XENSND_DRIVER_NAME " frontend driver\n");
+ xenbus_unregister_driver(&xen_driver);
+}
+
+module_init(xen_drv_init);
+module_exit(xen_drv_fini);
+
+MODULE_DESCRIPTION("Xen virtual sound device frontend");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("xen:" XENSND_DRIVER_NAME);
+MODULE_SUPPORTED_DEVICE("{{ALSA,Virtual soundcard}}");
diff --git a/sound/xen/xen_snd_front.h b/sound/xen/xen_snd_front.h
new file mode 100644
index 000000000000..4ae204b23d32
--- /dev/null
+++ b/sound/xen/xen_snd_front.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+/*
+ * Xen para-virtual sound device
+ *
+ * Copyright (C) 2016-2018 EPAM Systems Inc.
+ *
+ * Author: Oleksandr Andrushchenko <[email protected]>
+ */
+
+#ifndef __XEN_SND_FRONT_H
+#define __XEN_SND_FRONT_H
+
+struct xen_snd_front_info {
+ struct xenbus_device *xb_dev;
+};
+
+#endif /* __XEN_SND_FRONT_H */
--
2.17.0


2018-05-14 17:20:24

by Takashi Iwai

[permalink] [raw]
Subject: Re: [alsa-devel] [PATCH v3 0/6] ALSA: xen-front: Add Xen para-virtualized frontend driver

On Mon, 14 May 2018 08:27:36 +0200,
Oleksandr Andrushchenko wrote:
>
> From: Oleksandr Andrushchenko <[email protected]>
>
> Please note: this patch series depends on [3].
>
> This patch series adds support for Xen [1] para-virtualized
> sound frontend driver. It implements the protocol from
> include/xen/interface/io/sndif.h with the following limitations:
> - mute/unmute is not supported
> - get/set volume is not supported
> Volume control is not supported for the reason that most of the
> use-cases (at the moment) are based on scenarious where
> unprivileged OS (e.g. Android, AGL etc) use software mixers.
>
> Both capture and playback are supported.
>
> Corresponding backend, implemented as a user-space application, can be
> found at [2].

Through a quick glance, all look OK for merge (assuming that they
really work on your systems :)

Of course, it'd be great if anyone else can review, test and give
reviewed-by or tested-by tags. So I'll keep this floating for a
couple of days and merge to for-next branch after that.


thanks,

Takashi

2018-05-14 17:24:03

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: Re: [alsa-devel] [PATCH v3 0/6] ALSA: xen-front: Add Xen para-virtualized frontend driver

On 05/14/2018 06:52 PM, Takashi Iwai wrote:
> On Mon, 14 May 2018 08:27:36 +0200,
> Oleksandr Andrushchenko wrote:
>> From: Oleksandr Andrushchenko <[email protected]>
>>
>> Please note: this patch series depends on [3].
>>
>> This patch series adds support for Xen [1] para-virtualized
>> sound frontend driver. It implements the protocol from
>> include/xen/interface/io/sndif.h with the following limitations:
>> - mute/unmute is not supported
>> - get/set volume is not supported
>> Volume control is not supported for the reason that most of the
>> use-cases (at the moment) are based on scenarious where
>> unprivileged OS (e.g. Android, AGL etc) use software mixers.
>>
>> Both capture and playback are supported.
>>
>> Corresponding backend, implemented as a user-space application, can be
>> found at [2].
> Through a quick glance, all look OK for merge (assuming that they
> really work on your systems :)
Well, we have tested this at EPAM on Android/Linux, so this is it for now
>
> Of course, it'd be great if anyone else can review, test and give
> reviewed-by or tested-by tags.
I hope Juergen and Boris can review, at least Juergen had some comments
that I have addressed in v3
> So I'll keep this floating for a
> couple of days and merge to for-next branch after that.
Oh, this is great news! Thank you
>
> thanks,
>
> Takashi


2018-05-14 20:29:42

by Takashi Iwai

[permalink] [raw]
Subject: Re: [PATCH v3 4/6] ALSA: xen-front: Implement handling of shared buffers

On Mon, 14 May 2018 08:27:40 +0200,
Oleksandr Andrushchenko wrote:
> --- /dev/null
> +++ b/sound/xen/xen_snd_front_shbuf.c
> @@ -0,0 +1,193 @@
> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> +
> +/*
> + * Xen para-virtual sound device
> + *
> + * Copyright (C) 2016-2018 EPAM Systems Inc.
> + *
> + * Author: Oleksandr Andrushchenko <[email protected]>
> + */
> +
> +#include <xen/xen.h>
> +#include <xen/xenbus.h>
> +
> +#include "xen_snd_front_shbuf.h"

Hm, with the local build test, I get the following error:

CC [M] sound/xen/xen_snd_front_shbuf.o
In file included from sound/xen/xen_snd_front_shbuf.c:11:0:
./include/xen/xen.h:18:8: error: unknown type name ‘bool’
extern bool xen_pvh;
^~~~
In file included from ./include/xen/interface/xen.h:30:0,
from ./include/xen/xen.h:29,
from sound/xen/xen_snd_front_shbuf.c:11:
./arch/x86/include/asm/xen/interface.h:92:21: error: unknown type name ‘uint64_t’
DEFINE_GUEST_HANDLE(uint64_t);
^

Adding #include <linux/kernel.h> fixed the issue.

Did you really test your patches with the latest Linus tree?


thanks,

Takashi

2018-05-15 05:47:09

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: Re: [PATCH v3 4/6] ALSA: xen-front: Implement handling of shared buffers

On 05/14/2018 11:28 PM, Takashi Iwai wrote:
> On Mon, 14 May 2018 08:27:40 +0200,
> Oleksandr Andrushchenko wrote:
>> --- /dev/null
>> +++ b/sound/xen/xen_snd_front_shbuf.c
>> @@ -0,0 +1,193 @@
>> +// SPDX-License-Identifier: GPL-2.0 OR MIT
>> +
>> +/*
>> + * Xen para-virtual sound device
>> + *
>> + * Copyright (C) 2016-2018 EPAM Systems Inc.
>> + *
>> + * Author: Oleksandr Andrushchenko <[email protected]>
>> + */
>> +
>> +#include <xen/xen.h>
>> +#include <xen/xenbus.h>
>> +
>> +#include "xen_snd_front_shbuf.h"
> Hm, with the local build test, I get the following error:
>
> CC [M] sound/xen/xen_snd_front_shbuf.o
> In file included from sound/xen/xen_snd_front_shbuf.c:11:0:
> ./include/xen/xen.h:18:8: error: unknown type name ‘bool’
> extern bool xen_pvh;
> ^~~~
> In file included from ./include/xen/interface/xen.h:30:0,
> from ./include/xen/xen.h:29,
> from sound/xen/xen_snd_front_shbuf.c:11:
> ./arch/x86/include/asm/xen/interface.h:92:21: error: unknown type name ‘uint64_t’
> DEFINE_GUEST_HANDLE(uint64_t);
> ^
>
> Adding #include <linux/kernel.h> fixed the issue.
>
> Did you really test your patches with the latest Linus tree?
My bad, it does build for ARM (which is my target), but also does
need "#include <linux/kernel.h>" for x86 which I didn't build this time.
Sorry about that.

Do you want me to resend this single patch or you can make the change
while applying?
>
>
> thanks,
>
> Takashi
Thank you,
Oleksandr

2018-05-15 06:02:46

by Takashi Iwai

[permalink] [raw]
Subject: Re: [PATCH v3 4/6] ALSA: xen-front: Implement handling of shared buffers

On Tue, 15 May 2018 07:46:38 +0200,
Oleksandr Andrushchenko wrote:
>
> On 05/14/2018 11:28 PM, Takashi Iwai wrote:
> > On Mon, 14 May 2018 08:27:40 +0200,
> > Oleksandr Andrushchenko wrote:
> >> --- /dev/null
> >> +++ b/sound/xen/xen_snd_front_shbuf.c
> >> @@ -0,0 +1,193 @@
> >> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> >> +
> >> +/*
> >> + * Xen para-virtual sound device
> >> + *
> >> + * Copyright (C) 2016-2018 EPAM Systems Inc.
> >> + *
> >> + * Author: Oleksandr Andrushchenko <[email protected]>
> >> + */
> >> +
> >> +#include <xen/xen.h>
> >> +#include <xen/xenbus.h>
> >> +
> >> +#include "xen_snd_front_shbuf.h"
> > Hm, with the local build test, I get the following error:
> >
> > CC [M] sound/xen/xen_snd_front_shbuf.o
> > In file included from sound/xen/xen_snd_front_shbuf.c:11:0:
> > ./include/xen/xen.h:18:8: error: unknown type name ‘bool’
> > extern bool xen_pvh;
> > ^~~~
> > In file included from ./include/xen/interface/xen.h:30:0,
> > from ./include/xen/xen.h:29,
> > from sound/xen/xen_snd_front_shbuf.c:11:
> > ./arch/x86/include/asm/xen/interface.h:92:21: error: unknown type name ‘uint64_t’
> > DEFINE_GUEST_HANDLE(uint64_t);
> > ^
> >
> > Adding #include <linux/kernel.h> fixed the issue.
> >
> > Did you really test your patches with the latest Linus tree?
> My bad, it does build for ARM (which is my target), but also does
> need "#include <linux/kernel.h>" for x86 which I didn't build this time.
> Sorry about that.
>
> Do you want me to resend this single patch or you can make the change
> while applying?

Yes, it's fine.


thanks,

Takashi

2018-05-15 06:03:57

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: Re: [PATCH v3 4/6] ALSA: xen-front: Implement handling of shared buffers

On 05/15/2018 09:01 AM, Takashi Iwai wrote:
> On Tue, 15 May 2018 07:46:38 +0200,
> Oleksandr Andrushchenko wrote:
>> On 05/14/2018 11:28 PM, Takashi Iwai wrote:
>>> On Mon, 14 May 2018 08:27:40 +0200,
>>> Oleksandr Andrushchenko wrote:
>>>> --- /dev/null
>>>> +++ b/sound/xen/xen_snd_front_shbuf.c
>>>> @@ -0,0 +1,193 @@
>>>> +// SPDX-License-Identifier: GPL-2.0 OR MIT
>>>> +
>>>> +/*
>>>> + * Xen para-virtual sound device
>>>> + *
>>>> + * Copyright (C) 2016-2018 EPAM Systems Inc.
>>>> + *
>>>> + * Author: Oleksandr Andrushchenko <[email protected]>
>>>> + */
>>>> +
>>>> +#include <xen/xen.h>
>>>> +#include <xen/xenbus.h>
>>>> +
>>>> +#include "xen_snd_front_shbuf.h"
>>> Hm, with the local build test, I get the following error:
>>>
>>> CC [M] sound/xen/xen_snd_front_shbuf.o
>>> In file included from sound/xen/xen_snd_front_shbuf.c:11:0:
>>> ./include/xen/xen.h:18:8: error: unknown type name ‘bool’
>>> extern bool xen_pvh;
>>> ^~~~
>>> In file included from ./include/xen/interface/xen.h:30:0,
>>> from ./include/xen/xen.h:29,
>>> from sound/xen/xen_snd_front_shbuf.c:11:
>>> ./arch/x86/include/asm/xen/interface.h:92:21: error: unknown type name ‘uint64_t’
>>> DEFINE_GUEST_HANDLE(uint64_t);
>>> ^
>>>
>>> Adding #include <linux/kernel.h> fixed the issue.
>>>
>>> Did you really test your patches with the latest Linus tree?
>> My bad, it does build for ARM (which is my target), but also does
>> need "#include <linux/kernel.h>" for x86 which I didn't build this time.
>> Sorry about that.
>>
>> Do you want me to resend this single patch or you can make the change
>> while applying?
> Yes, it's fine.
Thank you
>
> thanks,
>
> Takashi


2018-05-17 06:27:23

by Takashi Iwai

[permalink] [raw]
Subject: Re: [PATCH v3 4/6] ALSA: xen-front: Implement handling of shared buffers

On Tue, 15 May 2018 08:02:08 +0200,
Oleksandr Andrushchenko wrote:
>
> On 05/15/2018 09:01 AM, Takashi Iwai wrote:
> > On Tue, 15 May 2018 07:46:38 +0200,
> > Oleksandr Andrushchenko wrote:
> >> On 05/14/2018 11:28 PM, Takashi Iwai wrote:
> >>> On Mon, 14 May 2018 08:27:40 +0200,
> >>> Oleksandr Andrushchenko wrote:
> >>>> --- /dev/null
> >>>> +++ b/sound/xen/xen_snd_front_shbuf.c
> >>>> @@ -0,0 +1,193 @@
> >>>> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> >>>> +
> >>>> +/*
> >>>> + * Xen para-virtual sound device
> >>>> + *
> >>>> + * Copyright (C) 2016-2018 EPAM Systems Inc.
> >>>> + *
> >>>> + * Author: Oleksandr Andrushchenko <[email protected]>
> >>>> + */
> >>>> +
> >>>> +#include <xen/xen.h>
> >>>> +#include <xen/xenbus.h>
> >>>> +
> >>>> +#include "xen_snd_front_shbuf.h"
> >>> Hm, with the local build test, I get the following error:
> >>>
> >>> CC [M] sound/xen/xen_snd_front_shbuf.o
> >>> In file included from sound/xen/xen_snd_front_shbuf.c:11:0:
> >>> ./include/xen/xen.h:18:8: error: unknown type name ‘bool’
> >>> extern bool xen_pvh;
> >>> ^~~~
> >>> In file included from ./include/xen/interface/xen.h:30:0,
> >>> from ./include/xen/xen.h:29,
> >>> from sound/xen/xen_snd_front_shbuf.c:11:
> >>> ./arch/x86/include/asm/xen/interface.h:92:21: error: unknown type name ‘uint64_t’
> >>> DEFINE_GUEST_HANDLE(uint64_t);
> >>> ^
> >>>
> >>> Adding #include <linux/kernel.h> fixed the issue.
> >>>
> >>> Did you really test your patches with the latest Linus tree?
> >> My bad, it does build for ARM (which is my target), but also does
> >> need "#include <linux/kernel.h>" for x86 which I didn't build this time.
> >> Sorry about that.
> >>
> >> Do you want me to resend this single patch or you can make the change
> >> while applying?
> > Yes, it's fine.
> Thank you

FWIW, the patches are in topic/xen branch in sound.git tree, and I'll
keep boiling for a while to see if any issues are caught by 0day bot.


Takashi

2018-05-17 06:33:47

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: Re: [PATCH v3 4/6] ALSA: xen-front: Implement handling of shared buffers

On 05/17/2018 09:26 AM, Takashi Iwai wrote:
> On Tue, 15 May 2018 08:02:08 +0200,
> Oleksandr Andrushchenko wrote:
>> On 05/15/2018 09:01 AM, Takashi Iwai wrote:
>>> On Tue, 15 May 2018 07:46:38 +0200,
>>> Oleksandr Andrushchenko wrote:
>>>> On 05/14/2018 11:28 PM, Takashi Iwai wrote:
>>>>> On Mon, 14 May 2018 08:27:40 +0200,
>>>>> Oleksandr Andrushchenko wrote:
>>>>>> --- /dev/null
>>>>>> +++ b/sound/xen/xen_snd_front_shbuf.c
>>>>>> @@ -0,0 +1,193 @@
>>>>>> +// SPDX-License-Identifier: GPL-2.0 OR MIT
>>>>>> +
>>>>>> +/*
>>>>>> + * Xen para-virtual sound device
>>>>>> + *
>>>>>> + * Copyright (C) 2016-2018 EPAM Systems Inc.
>>>>>> + *
>>>>>> + * Author: Oleksandr Andrushchenko <[email protected]>
>>>>>> + */
>>>>>> +
>>>>>> +#include <xen/xen.h>
>>>>>> +#include <xen/xenbus.h>
>>>>>> +
>>>>>> +#include "xen_snd_front_shbuf.h"
>>>>> Hm, with the local build test, I get the following error:
>>>>>
>>>>> CC [M] sound/xen/xen_snd_front_shbuf.o
>>>>> In file included from sound/xen/xen_snd_front_shbuf.c:11:0:
>>>>> ./include/xen/xen.h:18:8: error: unknown type name ‘bool’
>>>>> extern bool xen_pvh;
>>>>> ^~~~
>>>>> In file included from ./include/xen/interface/xen.h:30:0,
>>>>> from ./include/xen/xen.h:29,
>>>>> from sound/xen/xen_snd_front_shbuf.c:11:
>>>>> ./arch/x86/include/asm/xen/interface.h:92:21: error: unknown type name ‘uint64_t’
>>>>> DEFINE_GUEST_HANDLE(uint64_t);
>>>>> ^
>>>>>
>>>>> Adding #include <linux/kernel.h> fixed the issue.
>>>>>
>>>>> Did you really test your patches with the latest Linus tree?
>>>> My bad, it does build for ARM (which is my target), but also does
>>>> need "#include <linux/kernel.h>" for x86 which I didn't build this time.
>>>> Sorry about that.
>>>>
>>>> Do you want me to resend this single patch or you can make the change
>>>> while applying?
>>> Yes, it's fine.
>> Thank you
> FWIW, the patches are in topic/xen branch in sound.git tree, and I'll
> keep boiling for a while to see if any issues are caught by 0day bot.
Thank you, hope everything goes well
>
> Takashi
Thank you,
Oleksandr

2018-05-21 20:26:43

by Takashi Iwai

[permalink] [raw]
Subject: Re: [PATCH v3 4/6] ALSA: xen-front: Implement handling of shared buffers

On Thu, 17 May 2018 08:26:16 +0200,
Takashi Iwai wrote:
>
> On Tue, 15 May 2018 08:02:08 +0200,
> Oleksandr Andrushchenko wrote:
> >
> > On 05/15/2018 09:01 AM, Takashi Iwai wrote:
> > > On Tue, 15 May 2018 07:46:38 +0200,
> > > Oleksandr Andrushchenko wrote:
> > >> On 05/14/2018 11:28 PM, Takashi Iwai wrote:
> > >>> On Mon, 14 May 2018 08:27:40 +0200,
> > >>> Oleksandr Andrushchenko wrote:
> > >>>> --- /dev/null
> > >>>> +++ b/sound/xen/xen_snd_front_shbuf.c
> > >>>> @@ -0,0 +1,193 @@
> > >>>> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> > >>>> +
> > >>>> +/*
> > >>>> + * Xen para-virtual sound device
> > >>>> + *
> > >>>> + * Copyright (C) 2016-2018 EPAM Systems Inc.
> > >>>> + *
> > >>>> + * Author: Oleksandr Andrushchenko <[email protected]>
> > >>>> + */
> > >>>> +
> > >>>> +#include <xen/xen.h>
> > >>>> +#include <xen/xenbus.h>
> > >>>> +
> > >>>> +#include "xen_snd_front_shbuf.h"
> > >>> Hm, with the local build test, I get the following error:
> > >>>
> > >>> CC [M] sound/xen/xen_snd_front_shbuf.o
> > >>> In file included from sound/xen/xen_snd_front_shbuf.c:11:0:
> > >>> ./include/xen/xen.h:18:8: error: unknown type name ‘bool’
> > >>> extern bool xen_pvh;
> > >>> ^~~~
> > >>> In file included from ./include/xen/interface/xen.h:30:0,
> > >>> from ./include/xen/xen.h:29,
> > >>> from sound/xen/xen_snd_front_shbuf.c:11:
> > >>> ./arch/x86/include/asm/xen/interface.h:92:21: error: unknown type name ‘uint64_t’
> > >>> DEFINE_GUEST_HANDLE(uint64_t);
> > >>> ^
> > >>>
> > >>> Adding #include <linux/kernel.h> fixed the issue.
> > >>>
> > >>> Did you really test your patches with the latest Linus tree?
> > >> My bad, it does build for ARM (which is my target), but also does
> > >> need "#include <linux/kernel.h>" for x86 which I didn't build this time.
> > >> Sorry about that.
> > >>
> > >> Do you want me to resend this single patch or you can make the change
> > >> while applying?
> > > Yes, it's fine.
> > Thank you
>
> FWIW, the patches are in topic/xen branch in sound.git tree, and I'll
> keep boiling for a while to see if any issues are caught by 0day bot.

... and now the topic/xen branch got merged to for-next, targeted for
4.18.

Thanks for your patient works!


Takashi

2018-05-22 05:26:13

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: Re: [PATCH v3 4/6] ALSA: xen-front: Implement handling of shared buffers

On 05/21/2018 11:26 PM, Takashi Iwai wrote:
> On Thu, 17 May 2018 08:26:16 +0200,
> Takashi Iwai wrote:
>> On Tue, 15 May 2018 08:02:08 +0200,
>> Oleksandr Andrushchenko wrote:
>>> On 05/15/2018 09:01 AM, Takashi Iwai wrote:
>>>> On Tue, 15 May 2018 07:46:38 +0200,
>>>> Oleksandr Andrushchenko wrote:
>>>>> On 05/14/2018 11:28 PM, Takashi Iwai wrote:
>>>>>> On Mon, 14 May 2018 08:27:40 +0200,
>>>>>> Oleksandr Andrushchenko wrote:
>>>>>>> --- /dev/null
>>>>>>> +++ b/sound/xen/xen_snd_front_shbuf.c
>>>>>>> @@ -0,0 +1,193 @@
>>>>>>> +// SPDX-License-Identifier: GPL-2.0 OR MIT
>>>>>>> +
>>>>>>> +/*
>>>>>>> + * Xen para-virtual sound device
>>>>>>> + *
>>>>>>> + * Copyright (C) 2016-2018 EPAM Systems Inc.
>>>>>>> + *
>>>>>>> + * Author: Oleksandr Andrushchenko <[email protected]>
>>>>>>> + */
>>>>>>> +
>>>>>>> +#include <xen/xen.h>
>>>>>>> +#include <xen/xenbus.h>
>>>>>>> +
>>>>>>> +#include "xen_snd_front_shbuf.h"
>>>>>> Hm, with the local build test, I get the following error:
>>>>>>
>>>>>> CC [M] sound/xen/xen_snd_front_shbuf.o
>>>>>> In file included from sound/xen/xen_snd_front_shbuf.c:11:0:
>>>>>> ./include/xen/xen.h:18:8: error: unknown type name ‘bool’
>>>>>> extern bool xen_pvh;
>>>>>> ^~~~
>>>>>> In file included from ./include/xen/interface/xen.h:30:0,
>>>>>> from ./include/xen/xen.h:29,
>>>>>> from sound/xen/xen_snd_front_shbuf.c:11:
>>>>>> ./arch/x86/include/asm/xen/interface.h:92:21: error: unknown type name ‘uint64_t’
>>>>>> DEFINE_GUEST_HANDLE(uint64_t);
>>>>>> ^
>>>>>>
>>>>>> Adding #include <linux/kernel.h> fixed the issue.
>>>>>>
>>>>>> Did you really test your patches with the latest Linus tree?
>>>>> My bad, it does build for ARM (which is my target), but also does
>>>>> need "#include <linux/kernel.h>" for x86 which I didn't build this time.
>>>>> Sorry about that.
>>>>>
>>>>> Do you want me to resend this single patch or you can make the change
>>>>> while applying?
>>>> Yes, it's fine.
>>> Thank you
>> FWIW, the patches are in topic/xen branch in sound.git tree, and I'll
>> keep boiling for a while to see if any issues are caught by 0day bot.
> ... and now the topic/xen branch got merged to for-next, targeted for
> 4.18.
>
> Thanks for your patient works!
>
>
> Takashi
Great news, thank you,
Oleksandr

2018-05-23 04:01:14

by Takashi Sakamoto

[permalink] [raw]
Subject: Re: [PATCH v3 5/6] ALSA: xen-front: Implement ALSA virtual sound driver

Hi,

On May 14 2018 15:27, Oleksandr Andrushchenko wrote:
> diff --git a/sound/xen/xen_snd_front_alsa.c
b/sound/xen/xen_snd_front_alsa.c
> new file mode 100644
> index 000000000000..5041f83e98d2
> --- /dev/null
> +++ b/sound/xen/xen_snd_front_alsa.c
> ...
> +/*
> + * FIXME: The mmaped data transfer is asynchronous and there is no
> + * ack signal from user-space when it is done. This is the
> + * reason it is not implemented in the PV driver as we do need
> + * to know when the buffer can be transferred to the backend.
> + */
> ...

In ALSA PCM interface v2.0.14 or later, SNDRV_PCM_INFO_SYNC_APPLPTR is
available. This flag express that userspace applications are expected to
call ioctl(2) with 'SNDRV_PCM_IOCTL_SYNC_PTR' even if they oprate to
memory mapped page frames for PCM samples. For detail, please refer to a
commit 42f945970af9 ('ALSA: pcm: Add the explicit appl_ptr sync
support')[1].

As a supplement, please refer to below commits:
* 4b671f577474 ('ALSA: pcm: Add an ioctl to specify the supported
protocol version')[2]
* b602aa8eb1a0 ('ALSA: pcm: Disable only control mmap for explicit
appl_ptr sync')[3]

Alsa-lib v1.1.5 or later supports this flag and existent applications
can run transparently.

For developers, a tracepoint may be useful:
* fccf53881e9b ('ALSA: pcm: add 'applptr' event of tracepoint')[4]

For your information.

[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=42f945970af9
[2]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4b671f577474
[3]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b602aa8eb1a0
[4]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fccf53881e9b


Regards

Takashi Sakamoto

2018-05-23 06:15:08

by Oleksandr Andrushchenko

[permalink] [raw]
Subject: Re: [PATCH v3 5/6] ALSA: xen-front: Implement ALSA virtual sound driver

On 05/23/2018 07:00 AM, Takashi Sakamoto wrote:
> Hi,
>
> On May 14 2018 15:27, Oleksandr Andrushchenko wrote:
> > diff --git a/sound/xen/xen_snd_front_alsa.c
> b/sound/xen/xen_snd_front_alsa.c
> > new file mode 100644
> > index 000000000000..5041f83e98d2
> > --- /dev/null
> > +++ b/sound/xen/xen_snd_front_alsa.c
> > ...
> > +/*
> > + * FIXME: The mmaped data transfer is asynchronous and there is no
> > + * ack signal from user-space when it is done. This is the
> > + * reason it is not implemented in the PV driver as we do need
> > + * to know when the buffer can be transferred to the backend.
> > + */
> > ...
>
> In ALSA PCM interface v2.0.14 or later, SNDRV_PCM_INFO_SYNC_APPLPTR is
> available. This flag express that userspace applications are expected to
> call ioctl(2) with 'SNDRV_PCM_IOCTL_SYNC_PTR' even if they oprate to
> memory mapped page frames for PCM samples. For detail, please refer to a
> commit 42f945970af9 ('ALSA: pcm: Add the explicit appl_ptr sync
> support')[1].
>
> As a supplement, please refer to below commits:
>  * 4b671f577474 ('ALSA: pcm: Add an ioctl to specify the supported
>    protocol version')[2]
>  * b602aa8eb1a0 ('ALSA: pcm: Disable only control mmap for explicit
>    appl_ptr sync')[3]
>
> Alsa-lib v1.1.5 or later supports this flag and existent applications
> can run transparently.
>
> For developers, a tracepoint may be useful:
>  * fccf53881e9b ('ALSA: pcm: add 'applptr' event of tracepoint')[4]
>
> For your information.
>
> [1]
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=42f945970af9
> [2]
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4b671f577474
> [3]
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b602aa8eb1a0
> [4]
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fccf53881e9b
>
Oh, this is very useful, thank you so much for such a detailed
description. I'll take a close look at the above and see if
Xen sound driver can benefit from this.
>
> Regards
>
> Takashi Sakamoto
Thank you very much,
Oleksandr