[PATCH RESEND 10/11] ALSA: vsnd: Implement communication with backend

Oleksandr Andrushchenko
2017-08-07T11:51:54Z

Implement frontend to backend communication according to
the para-virtualized sound protocol: xen/interface/io/sndif.h.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
---
sound/drivers/xen-front.c | 302 +++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 288 insertions(+), 14 deletions(-)

diff --git a/sound/drivers/xen-front.c b/sound/drivers/xen-front.c
index 7275e9cb38c0..8bfec43ef03a 100644
--- a/sound/drivers/xen-front.c
+++ b/sound/drivers/xen-front.c
@@ -38,6 +38,8 @@
* because of the fact it is already in use/reserved by the PV console.
*/
#define GRANT_INVALID_REF 0
+/* timeout in ms to wait for backend to respond */
+#define VSND_WAIT_BACK_MS 3000
/* maximum number of supported streams */
#define VSND_MAX_STREAM 8

@@ -151,10 +153,12 @@ struct xdrv_info {
struct sdev_card_plat_data cfg_plat_data;
};

+static inline void xdrv_evtchnl_flush(struct xdrv_evtchnl_info *channel);
static inline void sh_buf_clear(struct sh_buf_info *buf);
static void sh_buf_free(struct sh_buf_info *buf);
static int sh_buf_alloc(struct xenbus_device *xb_dev, struct sh_buf_info *buf,
unsigned int buffer_size);
+static grant_ref_t sh_buf_get_dir_start(struct sh_buf_info *buf);

static struct sdev_pcm_stream_info *sdrv_stream_get(
struct snd_pcm_substream *substream)
@@ -314,6 +318,234 @@ static void sdrv_copy_pcm_hw(struct snd_pcm_hardware *dst,
}
}

+struct ALSA_SNDIF_SAMPLE_FORMAT {
+ uint8_t sndif;
+ snd_pcm_format_t alsa;
+};
+
+static 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 alsa_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 void sdrv_stream_clear(struct sdev_pcm_stream_info *stream)
+{
+ stream->is_open = false;
+ stream->req_next_id = 0;
+ sh_buf_clear(&stream->sh_buf);
+}
+
+static struct xensnd_req *sdrv_be_stream_prepare_req(
+ struct sdev_pcm_stream_info *stream, uint8_t operation)
+{
+ struct xensnd_req *req;
+
+ req = RING_GET_REQUEST(&stream->evt_chnl->ring,
+ stream->evt_chnl->ring.req_prod_pvt);
+ req->operation = operation;
+ req->id = stream->req_next_id++;
+ stream->evt_chnl->resp_id = req->id;
+ return req;
+}
+
+static void sdrv_be_stream_free(struct sdev_pcm_stream_info *stream)
+{
+ sh_buf_free(&stream->sh_buf);
+ sdrv_stream_clear(stream);
+}
+
+static int sdrv_be_stream_do_io(struct xdrv_evtchnl_info *evtchnl)
+{
+ if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED))
+ return -EIO;
+
+ reinit_completion(&evtchnl->completion);
+ xdrv_evtchnl_flush(evtchnl);
+ return 0;
+}
+
+static inline int sdrv_be_stream_wait_io(struct xdrv_evtchnl_info *evtchnl)
+{
+ if (wait_for_completion_timeout(
+ &evtchnl->completion,
+ msecs_to_jiffies(VSND_WAIT_BACK_MS)) <= 0)
+ return -ETIMEDOUT;
+ return 0;
+}
+
+static int sdrv_be_stream_open(struct snd_pcm_substream *substream,
+ struct sdev_pcm_stream_info *stream)
+{
+ struct sdev_pcm_instance_info *pcm_instance =
+ snd_pcm_substream_chip(substream);
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct xdrv_info *xdrv_info;
+ struct xensnd_req *req;
+ unsigned long flags;
+ int ret;
+
+ xdrv_info = pcm_instance->card_info->xdrv_info;
+
+ ret = alsa_to_sndif_format(runtime->format);
+ if (ret < 0) {
+ dev_err(&xdrv_info->xb_dev->dev,
+ "Unsupported sample format: %d\n", runtime->format);
+ return ret;
+ }
+
+ spin_lock_irqsave(&xdrv_info->io_lock, flags);
+ stream->is_open = false;
+ req = sdrv_be_stream_prepare_req(stream, XENSND_OP_OPEN);
+ req->op.open.pcm_format = (uint8_t)ret;
+ req->op.open.pcm_channels = runtime->channels;
+ req->op.open.pcm_rate = runtime->rate;
+ req->op.open.buffer_sz = stream->sh_buf.vbuffer_sz;
+ req->op.open.gref_directory = sh_buf_get_dir_start(&stream->sh_buf);
+
+ ret = sdrv_be_stream_do_io(stream->evt_chnl);
+ spin_unlock_irqrestore(&xdrv_info->io_lock, flags);
+
+ if (ret < 0)
+ return ret;
+
+ ret = sdrv_be_stream_wait_io(stream->evt_chnl);
+ stream->is_open = ret < 0 ? false : true;
+ return ret;
+}
+
+static int sdrv_be_stream_close(struct snd_pcm_substream *substream,
+ struct sdev_pcm_stream_info *stream)
+{
+ struct sdev_pcm_instance_info *pcm_instance =
+ snd_pcm_substream_chip(substream);
+ struct xdrv_info *xdrv_info;
+ struct xensnd_req *req;
+ unsigned long flags;
+ int ret;
+
+ xdrv_info = pcm_instance->card_info->xdrv_info;
+
+ spin_lock_irqsave(&xdrv_info->io_lock, flags);
+ stream->is_open = false;
+ req = sdrv_be_stream_prepare_req(stream, XENSND_OP_CLOSE);
+
+ ret = sdrv_be_stream_do_io(stream->evt_chnl);
+ spin_unlock_irqrestore(&xdrv_info->io_lock, flags);
+
+ if (ret < 0)
+ return ret;
+
+ return sdrv_be_stream_wait_io(stream->evt_chnl);
+}
+
static int sdrv_alsa_open(struct snd_pcm_substream *substream)
{
struct sdev_pcm_instance_info *pcm_instance =
@@ -339,7 +571,7 @@ static int sdrv_alsa_open(struct snd_pcm_substream *substream)
ret = sdrv_alsa_timer_create(substream);

spin_lock_irqsave(&xdrv_info->io_lock, flags);
- sh_buf_clear(&stream->sh_buf);
+ sdrv_stream_clear(stream);
stream->evt_chnl = &xdrv_info->evt_chnls[stream->unique_id];
if (ret < 0)
stream->evt_chnl->state = EVTCHNL_STATE_DISCONNECTED;
@@ -378,7 +610,7 @@ static int sdrv_alsa_hw_params(struct snd_pcm_substream *substream,
int ret;

buffer_size = params_buffer_bytes(params);
- sh_buf_clear(&stream->sh_buf);
+ sdrv_stream_clear(stream);
xdrv_info = pcm_instance->card_info->xdrv_info;
ret = sh_buf_alloc(xdrv_info->xb_dev,
&stream->sh_buf, buffer_size);
@@ -390,22 +622,18 @@ static int sdrv_alsa_hw_params(struct snd_pcm_substream *substream,
dev_err(&xdrv_info->xb_dev->dev,
"Failed to allocate buffers for stream idx %d\n",
stream->unique_id);
+ sdrv_be_stream_free(stream);
return ret;
}

static int sdrv_alsa_hw_free(struct snd_pcm_substream *substream)
{
- struct sdev_pcm_instance_info *pcm_instance =
- snd_pcm_substream_chip(substream);
struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
- struct xdrv_info *xdrv_info;
- unsigned long flags;
+ int ret;

- xdrv_info = pcm_instance->card_info->xdrv_info;
- spin_lock_irqsave(&xdrv_info->io_lock, flags);
- sh_buf_free(&stream->sh_buf);
- spin_unlock_irqrestore(&xdrv_info->io_lock, flags);
- return 0;
+ ret = sdrv_be_stream_close(substream, stream);
+ sdrv_be_stream_free(stream);
+ return ret;
}

static int sdrv_alsa_prepare(struct snd_pcm_substream *substream)
@@ -413,8 +641,12 @@ static int sdrv_alsa_prepare(struct snd_pcm_substream *substream)
struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
int ret = 0;

- if (!stream->is_open)
+ if (!stream->is_open) {
+ ret = sdrv_be_stream_open(substream, stream);
+ if (ret < 0)
+ return ret;
ret = sdrv_alsa_timer_prepare(substream);
+ }
return ret;
}

@@ -446,7 +678,28 @@ static inline snd_pcm_uframes_t sdrv_alsa_pointer(
static int sdrv_alsa_playback_do_write(struct snd_pcm_substream *substream,
unsigned long pos, unsigned long count)
{
- return 0;
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+ struct sdev_pcm_instance_info *pcm_instance =
+ snd_pcm_substream_chip(substream);
+ struct xdrv_info *xdrv_info;
+ struct xensnd_req *req;
+ unsigned long flags;
+ int ret;
+
+ xdrv_info = pcm_instance->card_info->xdrv_info;
+
+ spin_lock_irqsave(&xdrv_info->io_lock, flags);
+ req = sdrv_be_stream_prepare_req(stream, XENSND_OP_WRITE);
+ req->op.rw.length = count;
+ req->op.rw.offset = pos;
+
+ ret = sdrv_be_stream_do_io(stream->evt_chnl);
+ spin_unlock_irqrestore(&xdrv_info->io_lock, flags);
+
+ if (ret < 0)
+ return ret;
+
+ return sdrv_be_stream_wait_io(stream->evt_chnl);
}

static int sdrv_alsa_playback_copy_user(struct snd_pcm_substream *substream,
@@ -479,7 +732,28 @@ static int sdrv_alsa_playback_copy_kernel(struct snd_pcm_substream *substream,
static int sdrv_alsa_playback_do_read(struct snd_pcm_substream *substream,
unsigned long pos, unsigned long count)
{
- return 0;
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+ struct sdev_pcm_instance_info *pcm_instance =
+ snd_pcm_substream_chip(substream);
+ struct xdrv_info *xdrv_info;
+ struct xensnd_req *req;
+ unsigned long flags;
+ int ret;
+
+ xdrv_info = pcm_instance->card_info->xdrv_info;
+
+ spin_lock_irqsave(&xdrv_info->io_lock, flags);
+ req = sdrv_be_stream_prepare_req(stream, XENSND_OP_READ);
+ req->op.rw.length = count;
+ req->op.rw.offset = pos;
+
+ ret = sdrv_be_stream_do_io(stream->evt_chnl);
+ spin_unlock_irqrestore(&xdrv_info->io_lock, flags);
+
+ if (ret < 0)
+ return ret;
+
+ return sdrv_be_stream_wait_io(stream->evt_chnl);
}

static int sdrv_alsa_capture_copy_user(struct snd_pcm_substream *substream,
--
2.7.4