Introduce the operators required for the operation of substreams.
Signed-off-by: Anton Yakovlev anton.yakovlev@opensynergy.com --- sound/virtio/Makefile | 3 +- sound/virtio/virtio_pcm.c | 5 +- sound/virtio/virtio_pcm.h | 2 + sound/virtio/virtio_pcm_ops.c | 513 ++++++++++++++++++++++++++++++++++ 4 files changed, 521 insertions(+), 2 deletions(-) create mode 100644 sound/virtio/virtio_pcm_ops.c
diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile index 626af3cc3ed7..34493226793f 100644 --- a/sound/virtio/Makefile +++ b/sound/virtio/Makefile @@ -6,5 +6,6 @@ virtio_snd-objs := \ virtio_card.o \ virtio_ctl_msg.o \ virtio_pcm.o \ - virtio_pcm_msg.o + virtio_pcm_msg.o \ + virtio_pcm_ops.o
diff --git a/sound/virtio/virtio_pcm.c b/sound/virtio/virtio_pcm.c index 1ab50dcc88c8..6a1ca6b2c3ca 100644 --- a/sound/virtio/virtio_pcm.c +++ b/sound/virtio/virtio_pcm.c @@ -121,7 +121,8 @@ static int virtsnd_pcm_build_hw(struct virtio_pcm_substream *substream, SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_BATCH | SNDRV_PCM_INFO_BLOCK_TRANSFER | - SNDRV_PCM_INFO_INTERLEAVED; + SNDRV_PCM_INFO_INTERLEAVED | + SNDRV_PCM_INFO_PAUSE;
if (!info->channels_min || info->channels_min > info->channels_max) { dev_err(&vdev->dev, @@ -503,6 +504,8 @@ int virtsnd_pcm_build_devs(struct virtio_snd *snd) if (rc) return rc; } + + snd_pcm_set_ops(pcm->pcm, i, &virtsnd_pcm_ops); }
return 0; diff --git a/sound/virtio/virtio_pcm.h b/sound/virtio/virtio_pcm.h index d011b7e1d18d..fe467bc05d8b 100644 --- a/sound/virtio/virtio_pcm.h +++ b/sound/virtio/virtio_pcm.h @@ -90,6 +90,8 @@ struct virtio_pcm { struct virtio_pcm_stream streams[SNDRV_PCM_STREAM_LAST + 1]; };
+extern const struct snd_pcm_ops virtsnd_pcm_ops; + int virtsnd_pcm_validate(struct virtio_device *vdev);
int virtsnd_pcm_parse_cfg(struct virtio_snd *snd); diff --git a/sound/virtio/virtio_pcm_ops.c b/sound/virtio/virtio_pcm_ops.c new file mode 100644 index 000000000000..19882777fcd6 --- /dev/null +++ b/sound/virtio/virtio_pcm_ops.c @@ -0,0 +1,513 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Sound card driver for virtio + * Copyright (C) 2020 OpenSynergy GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see http://www.gnu.org/licenses/. + */ +#include <sound/pcm_params.h> + +#include "virtio_card.h" + +/* + * Our main concern here is maintaining the correct state of the underlying I/O + * virtqueues. Thus, operators are implemented to support all of the following + * possible control paths (excluding all trivial ones): + * + * +---------+ + * | open() |<------------------+ + * +----+----+ | + * v | + * +------+------+ | + * +------------->| hw_params() |<-------------+ | + * | +-------------+ | | + * | v | | + * | +-----------+ | | + * | | prepare() |<-----------+ | | + * | +-----------+ | | | + * | v | | | + * | +-------------------------+ | | | + * +-----------+ | trigger(START/ | | | | + * | restore() | | PAUSE_RELEASE/ |<-+ | | | + * +-----------+ | RESUME) | | | | | + * ^ +-------------------------+ | | | | + * | v | | | | + * | +-----------+ | | | | + * | | pointer() | | | | | + * | +-----------+ | | | | + * | v | | | | + * | +---------------------+ | | | | + * +-----------+ | trigger(STOP/ |----+ | | | + * | freeze() |<---| PAUSE_PUSH/ |-------+ | | + * +-----------+ | SUSPEND) | | | + * +---------------------+ | | + * v | | + * +-----------+ | | + * | hw_free() |---------------+ | + * +-----------+ | + * v | + * +---------+ | + * | close() |-------------------+ + * +---------+ + */ + +/* Map for converting ALSA format to VirtIO format. */ +struct virtsnd_a2v_format { + unsigned int alsa_bit; + unsigned int vio_bit; +}; + +static const struct virtsnd_a2v_format g_a2v_format_map[] = { + { SNDRV_PCM_FORMAT_IMA_ADPCM, VIRTIO_SND_PCM_FMT_IMA_ADPCM }, + { SNDRV_PCM_FORMAT_MU_LAW, VIRTIO_SND_PCM_FMT_MU_LAW }, + { SNDRV_PCM_FORMAT_A_LAW, VIRTIO_SND_PCM_FMT_A_LAW }, + { SNDRV_PCM_FORMAT_S8, VIRTIO_SND_PCM_FMT_S8 }, + { SNDRV_PCM_FORMAT_U8, VIRTIO_SND_PCM_FMT_U8 }, + { SNDRV_PCM_FORMAT_S16_LE, VIRTIO_SND_PCM_FMT_S16 }, + { SNDRV_PCM_FORMAT_U16_LE, VIRTIO_SND_PCM_FMT_U16 }, + { SNDRV_PCM_FORMAT_S18_3LE, VIRTIO_SND_PCM_FMT_S18_3 }, + { SNDRV_PCM_FORMAT_U18_3LE, VIRTIO_SND_PCM_FMT_U18_3 }, + { SNDRV_PCM_FORMAT_S20_3LE, VIRTIO_SND_PCM_FMT_S20_3 }, + { SNDRV_PCM_FORMAT_U20_3LE, VIRTIO_SND_PCM_FMT_U20_3 }, + { SNDRV_PCM_FORMAT_S24_3LE, VIRTIO_SND_PCM_FMT_S24_3 }, + { SNDRV_PCM_FORMAT_U24_3LE, VIRTIO_SND_PCM_FMT_U24_3 }, + { SNDRV_PCM_FORMAT_S20_LE, VIRTIO_SND_PCM_FMT_S20 }, + { SNDRV_PCM_FORMAT_U20_LE, VIRTIO_SND_PCM_FMT_U20 }, + { SNDRV_PCM_FORMAT_S24_LE, VIRTIO_SND_PCM_FMT_S24 }, + { SNDRV_PCM_FORMAT_U24_LE, VIRTIO_SND_PCM_FMT_U24 }, + { SNDRV_PCM_FORMAT_S32_LE, VIRTIO_SND_PCM_FMT_S32 }, + { SNDRV_PCM_FORMAT_U32_LE, VIRTIO_SND_PCM_FMT_U32 }, + { SNDRV_PCM_FORMAT_FLOAT_LE, VIRTIO_SND_PCM_FMT_FLOAT }, + { SNDRV_PCM_FORMAT_FLOAT64_LE, VIRTIO_SND_PCM_FMT_FLOAT64 }, + { SNDRV_PCM_FORMAT_DSD_U8, VIRTIO_SND_PCM_FMT_DSD_U8 }, + { SNDRV_PCM_FORMAT_DSD_U16_LE, VIRTIO_SND_PCM_FMT_DSD_U16 }, + { SNDRV_PCM_FORMAT_DSD_U32_LE, VIRTIO_SND_PCM_FMT_DSD_U32 }, + { SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE, + VIRTIO_SND_PCM_FMT_IEC958_SUBFRAME } +}; + +/* Map for converting ALSA frame rate to VirtIO frame rate. */ +struct virtsnd_a2v_rate { + unsigned int rate; + unsigned int vio_bit; +}; + +static const struct virtsnd_a2v_rate g_a2v_rate_map[] = { + { 5512, VIRTIO_SND_PCM_RATE_5512 }, + { 8000, VIRTIO_SND_PCM_RATE_8000 }, + { 11025, VIRTIO_SND_PCM_RATE_11025 }, + { 16000, VIRTIO_SND_PCM_RATE_16000 }, + { 22050, VIRTIO_SND_PCM_RATE_22050 }, + { 32000, VIRTIO_SND_PCM_RATE_32000 }, + { 44100, VIRTIO_SND_PCM_RATE_44100 }, + { 48000, VIRTIO_SND_PCM_RATE_48000 }, + { 64000, VIRTIO_SND_PCM_RATE_64000 }, + { 88200, VIRTIO_SND_PCM_RATE_88200 }, + { 96000, VIRTIO_SND_PCM_RATE_96000 }, + { 176400, VIRTIO_SND_PCM_RATE_176400 }, + { 192000, VIRTIO_SND_PCM_RATE_192000 } +}; + +/** + * virtsnd_pcm_release() - Release the PCM substream on the device side. + * @substream: VirtIO substream. + * + * Context: Any context that permits to sleep. + * Return: 0 on success, -errno on failure. + */ +static inline bool virtsnd_pcm_released(struct virtio_pcm_substream *substream) +{ + /* + * The spec states that upon receipt of the RELEASE command "the device + * MUST complete all pending I/O messages for the specified stream ID". + * Thus, we consider the absence of I/O messages in the queue as an + * indication that the substream has been released. + */ + return atomic_read(&substream->msg_count) == 0; +} + +static int virtsnd_pcm_release(struct virtio_pcm_substream *substream) +{ + struct virtio_snd *snd = substream->snd; + struct virtio_snd_msg *msg; + unsigned int js = msecs_to_jiffies(msg_timeout_ms); + int rc; + + msg = virtsnd_pcm_ctl_msg_alloc(substream, VIRTIO_SND_R_PCM_RELEASE, + GFP_KERNEL); + if (IS_ERR(msg)) + return PTR_ERR(msg); + + rc = virtsnd_ctl_msg_send_sync(snd, msg); + if (rc) + return rc; + + return wait_event_interruptible_timeout(substream->msg_empty, + virtsnd_pcm_released(substream), + js); +} + +/** + * virtsnd_pcm_open() - Open the PCM substream. + * @substream: Kernel ALSA substream. + * + * Context: Any context. + * Return: 0 on success, -errno on failure. + */ +static int virtsnd_pcm_open(struct snd_pcm_substream *substream) +{ + struct virtio_pcm *pcm = snd_pcm_substream_chip(substream); + struct virtio_pcm_substream *ss = NULL; + + if (pcm) { + switch (substream->stream) { + case SNDRV_PCM_STREAM_PLAYBACK: + case SNDRV_PCM_STREAM_CAPTURE: { + struct virtio_pcm_stream *stream = + &pcm->streams[substream->stream]; + + if (substream->number < stream->nsubstreams) + ss = stream->substreams[substream->number]; + break; + } + } + } + + if (!ss) + return -EBADFD; + + substream->runtime->hw = ss->hw; + substream->private_data = ss; + + return 0; +} + +/** + * virtsnd_pcm_close() - Close the PCM substream. + * @substream: Kernel ALSA substream. + * + * Context: Any context. + * Return: 0. + */ +static int virtsnd_pcm_close(struct snd_pcm_substream *substream) +{ + return 0; +} + +/** + * virtsnd_pcm_hw_params() - Set the parameters of the PCM substream. + * @substream: Kernel ALSA substream. + * @hw_params: Hardware parameters (can be NULL). + * + * The function can be called both from the upper level (in this case, + * @hw_params is not NULL) or from the driver itself (in this case, @hw_params + * is NULL, and the parameter values are taken from the runtime structure). + * + * In all cases, the function: + * 1. checks the state of the virtqueue and, if necessary, tries to fix it, + * 2. sets the parameters on the device side, + * 3. allocates a hardware buffer and I/O messages. + * + * Context: Any context that permits to sleep. + * Return: 0 on success, -errno on failure. + */ +static int virtsnd_pcm_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *hw_params) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + struct virtio_pcm_substream *ss = snd_pcm_substream_chip(substream); + struct virtio_device *vdev = ss->snd->vdev; + struct virtio_snd_msg *msg; + struct virtio_snd_pcm_set_params *request; + snd_pcm_format_t format; + unsigned int channels; + unsigned int rate; + unsigned int buffer_bytes; + unsigned int period_bytes; + unsigned int periods; + unsigned int i; + int vformat = -1; + int vrate = -1; + int rc; + + /* + * If we got here after ops->trigger() was called, the queue may + * still contain messages. In this case, we need to release the + * substream first. + */ + if (atomic_read(&ss->msg_count)) { + rc = virtsnd_pcm_release(ss); + if (rc) { + dev_err(&vdev->dev, + "SID %u: invalid I/O queue state\n", + ss->sid); + return rc; + } + } + + /* Set hardware parameters in device */ + if (hw_params) { + format = params_format(hw_params); + channels = params_channels(hw_params); + rate = params_rate(hw_params); + buffer_bytes = params_buffer_bytes(hw_params); + period_bytes = params_period_bytes(hw_params); + periods = params_periods(hw_params); + } else { + format = runtime->format; + channels = runtime->channels; + rate = runtime->rate; + buffer_bytes = frames_to_bytes(runtime, runtime->buffer_size); + period_bytes = frames_to_bytes(runtime, runtime->period_size); + periods = runtime->periods; + } + + for (i = 0; i < ARRAY_SIZE(g_a2v_format_map); ++i) + if (g_a2v_format_map[i].alsa_bit == format) { + vformat = g_a2v_format_map[i].vio_bit; + + break; + } + + for (i = 0; i < ARRAY_SIZE(g_a2v_rate_map); ++i) + if (g_a2v_rate_map[i].rate == rate) { + vrate = g_a2v_rate_map[i].vio_bit; + + break; + } + + if (vformat == -1 || vrate == -1) + return -EINVAL; + + msg = virtsnd_pcm_ctl_msg_alloc(ss, VIRTIO_SND_R_PCM_SET_PARAMS, + GFP_KERNEL); + if (IS_ERR(msg)) + return PTR_ERR(msg); + + request = sg_virt(&msg->sg_request); + + request->buffer_bytes = cpu_to_virtio32(vdev, buffer_bytes); + request->period_bytes = cpu_to_virtio32(vdev, period_bytes); + request->channels = channels; + request->format = vformat; + request->rate = vrate; + + if (ss->features & (1U << VIRTIO_SND_PCM_F_MSG_POLLING)) + request->features |= + cpu_to_virtio32(vdev, + 1U << VIRTIO_SND_PCM_F_MSG_POLLING); + + if (ss->features & (1U << VIRTIO_SND_PCM_F_EVT_XRUNS)) + request->features |= + cpu_to_virtio32(vdev, + 1U << VIRTIO_SND_PCM_F_EVT_XRUNS); + + rc = virtsnd_ctl_msg_send_sync(ss->snd, msg); + if (rc) + return rc; + + /* If the buffer was already allocated earlier, do nothing. */ + if (runtime->dma_area) + return 0; + + /* Allocate hardware buffer */ + rc = snd_pcm_lib_malloc_pages(substream, buffer_bytes); + if (rc < 0) + return rc; + + /* Allocate and initialize I/O messages */ + rc = virtsnd_pcm_msg_alloc(ss, periods, runtime->dma_area, + period_bytes); + if (rc) + snd_pcm_lib_free_pages(substream); + + return rc; +} + +/** + * virtsnd_pcm_hw_free() - Reset the parameters of the PCM substream. + * @substream: Kernel ALSA substream. + * + * The function does the following: + * 1. tries to release the PCM substream on the device side, + * 2. frees the hardware buffer. + * + * Context: Any context that permits to sleep. + * Return: 0 on success, -errno on failure. + */ +static int virtsnd_pcm_hw_free(struct snd_pcm_substream *substream) +{ + struct virtio_pcm_substream *ss = snd_pcm_substream_chip(substream); + int rc; + + rc = virtsnd_pcm_release(ss); + + /* + * Even if we failed to send the RELEASE message or wait for the queue + * flush to complete, we can safely delete the buffer. Because after + * receiving the STOP command, the device must stop all I/O message + * processing. If there are still pending messages in the queue, the + * next ops->hw_params() call should deal with this. + */ + snd_pcm_lib_free_pages(substream); + + return rc; +} + +/** + * virtsnd_pcm_hw_params() - Prepare the PCM substream. + * @substream: Kernel ALSA substream. + * + * The function can be called both from the upper level or from the driver + * itself. + * + * In all cases, the function: + * 1. checks the state of the virtqueue and, if necessary, tries to fix it, + * 2. prepares the substream on the device side. + * + * Context: Any context that permits to sleep. May take and release the tx/rx + * queue spinlock. + * Return: 0 on success, -errno on failure. + */ +static int virtsnd_pcm_prepare(struct snd_pcm_substream *substream) +{ + struct virtio_pcm_substream *ss = snd_pcm_substream_chip(substream); + struct virtio_snd_queue *queue = virtsnd_pcm_queue(ss); + struct virtio_snd_msg *msg; + unsigned long flags; + int rc; + + /* + * If we got here after ops->trigger() was called, the queue may + * still contain messages. In this case, we need to reset the + * substream first. + */ + if (atomic_read(&ss->msg_count)) { + rc = virtsnd_pcm_hw_params(substream, NULL); + if (rc) + return rc; + } + + spin_lock_irqsave(&queue->lock, flags); + ss->msg_last_enqueued = -1; + spin_unlock_irqrestore(&queue->lock, flags); + + /* + * Since I/O messages are asynchronous, they can be completed + * when the runtime structure no longer exists. Since each + * completion implies incrementing the hw_ptr, we cache all the + * current values needed to compute the new hw_ptr value. + */ + ss->frame_bytes = substream->runtime->frame_bits >> 3; + ss->period_size = substream->runtime->period_size; + ss->buffer_size = substream->runtime->buffer_size; + + atomic_set(&ss->hw_ptr, 0); + atomic_set(&ss->xfer_xrun, 0); + atomic_set(&ss->msg_count, 0); + + msg = virtsnd_pcm_ctl_msg_alloc(ss, VIRTIO_SND_R_PCM_PREPARE, + GFP_KERNEL); + if (IS_ERR(msg)) + return PTR_ERR(msg); + + return virtsnd_ctl_msg_send_sync(ss->snd, msg); +} + +/** + * virtsnd_pcm_trigger() - Process command for the PCM substream. + * @substream: Kernel ALSA substream. + * @command: Substream command (SNDRV_PCM_TRIGGER_XXX). + * + * Depending on the command, the function does the following: + * 1. enables/disables data transmission, + * 2. starts/stops the substream on the device side. + * + * Context: Atomic context. May take and release the tx/rx queue spinlock. + * Return: 0 on success, -errno on failure. + */ +static int virtsnd_pcm_trigger(struct snd_pcm_substream *substream, int command) +{ + struct virtio_pcm_substream *ss = snd_pcm_substream_chip(substream); + struct virtio_snd *snd = ss->snd; + struct virtio_snd_queue *queue = virtsnd_pcm_queue(ss); + struct virtio_snd_msg *msg; + + switch (command) { + case SNDRV_PCM_TRIGGER_START: + case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: { + int rc; + + spin_lock(&queue->lock); + rc = virtsnd_pcm_msg_send(ss); + spin_unlock(&queue->lock); + if (rc) + return rc; + + atomic_set(&ss->xfer_enabled, 1); + + msg = virtsnd_pcm_ctl_msg_alloc(ss, VIRTIO_SND_R_PCM_START, + GFP_ATOMIC); + if (IS_ERR(msg)) + return PTR_ERR(msg); + + return virtsnd_ctl_msg_send(snd, msg); + } + case SNDRV_PCM_TRIGGER_STOP: + case SNDRV_PCM_TRIGGER_PAUSE_PUSH: { + atomic_set(&ss->xfer_enabled, 0); + + msg = virtsnd_pcm_ctl_msg_alloc(ss, VIRTIO_SND_R_PCM_STOP, + GFP_ATOMIC); + if (IS_ERR(msg)) + return PTR_ERR(msg); + + return virtsnd_ctl_msg_send(snd, msg); + } + default: { + return -EINVAL; + } + } +} + +/** + * virtsnd_pcm_pointer() - Get the current hardware position for the PCM + * substream. + * @substream: Kernel ALSA substream. + * + * Context: Atomic context. + * Return: Hardware position in frames inside [0 ... buffer_size) range. + */ +static snd_pcm_uframes_t +virtsnd_pcm_pointer(struct snd_pcm_substream *substream) +{ + struct virtio_pcm_substream *ss = snd_pcm_substream_chip(substream); + + if (atomic_read(&ss->xfer_xrun)) + return SNDRV_PCM_POS_XRUN; + + return (snd_pcm_uframes_t)atomic_read(&ss->hw_ptr); +} + +/* PCM substream operators map. */ +const struct snd_pcm_ops virtsnd_pcm_ops = { + .open = virtsnd_pcm_open, + .close = virtsnd_pcm_close, + .ioctl = snd_pcm_lib_ioctl, + .hw_params = virtsnd_pcm_hw_params, + .hw_free = virtsnd_pcm_hw_free, + .prepare = virtsnd_pcm_prepare, + .trigger = virtsnd_pcm_trigger, + .pointer = virtsnd_pcm_pointer, +};