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ALSA: xen-front: Implement ALSA virtual sound driver

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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 <oleksandr_andrushchenko@epam.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Oleksandr Andrushchenko 2018-05-14 09:27:41 +03:00 committed by Takashi Iwai
parent d6e0fbb82e
commit 1cee559351
6 changed files with 1056 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
sound/xen/Makefile
View File

@ -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

181
sound/xen/xen_snd_front.c
View File

@ -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)

27
sound/xen/xen_snd_front.h
View File

@ -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 */

821
sound/xen/xen_snd_front_alsa.c Normal file
View File

@ -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 <oleksandr_andrushchenko@epam.com>
*/
#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;
}

23
sound/xen/xen_snd_front_alsa.h Normal file
View File

@ -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 <oleksandr_andrushchenko@epam.com>
*/
#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 */

4
sound/xen/xen_snd_front_evtchnl.c
View File

@ -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;
}
}