Message ID | 20210120003638.3339987-1-anton.yakovlev@opensynergy.com |
---|---|
Headers | show |
Series | ALSA: add virtio sound driver | expand |
On Wed, Jan 20, 2021 at 01:36:33AM +0100, Anton Yakovlev wrote: > 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 | 509 ++++++++++++++++++++++++++++++++++ > 4 files changed, 517 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..8d26c1144ad6 > --- /dev/null > +++ b/sound/virtio/virtio_pcm_ops.c > @@ -0,0 +1,509 @@ > +// 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. > + * > + * The function waits for all pending I/O messages to complete. > + * > + * 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) > +{ > + return atomic_read(&substream->msg_count) == 0; All this use of atomic_read/atomic_set all over the place makes me pause. Could you add documentation explaining the use rules for these atomic fields? > +} > + > +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, > +}; > -- > 2.30.0 > >
On 20.01.2021 09:29, Michael S. Tsirkin wrote: > CAUTION: This email originated from outside of the organization. > Do not click links or open attachments unless you recognize the sender and know the content is safe. > > > On Wed, Jan 20, 2021 at 01:36:32AM +0100, Anton Yakovlev wrote: >> The driver implements a message-based transport for I/O substream >> operations. Before the start of the substream, the hardware buffer is >> sliced into I/O messages, the number of which is equal to the current >> number of periods. The size of each message is equal to the current >> size of one period. >> >> I/O messages are organized in an ordered queue. The completion of the >> I/O message indicates an expired period (the only exception is the end >> of the stream for the capture substream). Upon completion, the message >> is automatically re-added to the end of the queue. >> >> When an I/O message is completed, the hw_ptr value is incremented >> unconditionally (to ensure that the hw_ptr always correctly reflects >> the state of the messages in the virtqueue). Due to its asynchronous >> nature, a message can be completed when the runtime structure no longer >> exists. For this reason, the values from this structure are cached in >> the virtio substream, which are required to calculate the new value of >> the hw_ptr. >> >> Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com> >> --- >> sound/virtio/Makefile | 3 +- >> sound/virtio/virtio_card.c | 33 ++++ >> sound/virtio/virtio_card.h | 9 + >> sound/virtio/virtio_pcm.c | 3 + >> sound/virtio/virtio_pcm.h | 31 ++++ >> sound/virtio/virtio_pcm_msg.c | 317 ++++++++++++++++++++++++++++++++++ >> 6 files changed, 395 insertions(+), 1 deletion(-) >> create mode 100644 sound/virtio/virtio_pcm_msg.c >> >> diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile >> index 69162a545a41..626af3cc3ed7 100644 >> --- a/sound/virtio/Makefile >> +++ b/sound/virtio/Makefile >> @@ -5,5 +5,6 @@ obj-$(CONFIG_SND_VIRTIO) += virtio_snd.o >> virtio_snd-objs := \ >> virtio_card.o \ >> virtio_ctl_msg.o \ >> - virtio_pcm.o >> + virtio_pcm.o \ >> + virtio_pcm_msg.o >> >> diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c >> index 293d497f24e7..dc703fc662f5 100644 >> --- a/sound/virtio/virtio_card.c >> +++ b/sound/virtio/virtio_card.c >> @@ -145,6 +145,12 @@ static int virtsnd_find_vqs(struct virtio_snd *snd) >> callbacks[VIRTIO_SND_VQ_CONTROL] = virtsnd_ctl_notify_cb; >> callbacks[VIRTIO_SND_VQ_EVENT] = virtsnd_event_notify_cb; >> >> + virtio_cread(vdev, struct virtio_snd_config, streams, &n); >> + if (n) { >> + callbacks[VIRTIO_SND_VQ_TX] = virtsnd_pcm_tx_notify_cb; >> + callbacks[VIRTIO_SND_VQ_RX] = virtsnd_pcm_rx_notify_cb; >> + } >> + >> rc = virtio_find_vqs(vdev, VIRTIO_SND_VQ_MAX, vqs, callbacks, names, >> NULL); >> if (rc) { >> @@ -186,15 +192,42 @@ static int virtsnd_find_vqs(struct virtio_snd *snd) >> * virtsnd_enable_vqs() - Enable the event, tx and rx virtqueues. >> * @snd: VirtIO sound device. >> * >> + * The tx queue is enabled only if the device supports playback stream(s). >> + * >> + * The rx queue is enabled only if the device supports capture stream(s). >> + * >> * Context: Any context. >> */ >> static void virtsnd_enable_vqs(struct virtio_snd *snd) >> { >> + struct virtio_device *vdev = snd->vdev; >> struct virtqueue *vqueue; >> + struct virtio_pcm *pcm; >> + unsigned int npbs = 0; >> + unsigned int ncps = 0; >> >> vqueue = snd->queues[VIRTIO_SND_VQ_EVENT].vqueue; >> if (!virtqueue_enable_cb(vqueue)) >> virtsnd_event_notify_cb(vqueue); >> + >> + list_for_each_entry(pcm, &snd->pcm_list, list) { >> + npbs += pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].nsubstreams; >> + ncps += pcm->streams[SNDRV_PCM_STREAM_CAPTURE].nsubstreams; >> + } >> + >> + if (npbs) { >> + vqueue = snd->queues[VIRTIO_SND_VQ_TX].vqueue; >> + if (!virtqueue_enable_cb(vqueue)) >> + dev_warn(&vdev->dev, >> + "suspicious notification in the TX queue\n"); >> + } >> + >> + if (ncps) { >> + vqueue = snd->queues[VIRTIO_SND_VQ_RX].vqueue; >> + if (!virtqueue_enable_cb(vqueue)) >> + dev_warn(&vdev->dev, >> + "suspicious notification in the RX queue\n"); >> + } > > Not sure how all this prevents use of same vq from multiple threads ... > And why are we sure there are no buffers yet? If that is because > nothing yet happened, then I'd also like to point out that a vq starts > out with callbacks enabled, so you don't need to do that first thing ... Yes, I redone that logic in v2. >> } >> >> /** >> diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h >> index be6651a6aaf8..b11c09984882 100644 >> --- a/sound/virtio/virtio_card.h >> +++ b/sound/virtio/virtio_card.h >> @@ -89,4 +89,13 @@ virtsnd_rx_queue(struct virtio_snd *snd) >> return &snd->queues[VIRTIO_SND_VQ_RX]; >> } >> >> +static inline struct virtio_snd_queue * >> +virtsnd_pcm_queue(struct virtio_pcm_substream *substream) >> +{ >> + if (substream->direction == SNDRV_PCM_STREAM_PLAYBACK) >> + return virtsnd_tx_queue(substream->snd); >> + else >> + return virtsnd_rx_queue(substream->snd); >> +} >> + >> #endif /* VIRTIO_SND_CARD_H */ >> diff --git a/sound/virtio/virtio_pcm.c b/sound/virtio/virtio_pcm.c >> index 036990b7b78a..1ab50dcc88c8 100644 >> --- a/sound/virtio/virtio_pcm.c >> +++ b/sound/virtio/virtio_pcm.c >> @@ -376,6 +376,7 @@ int virtsnd_pcm_parse_cfg(struct virtio_snd *snd) >> >> substream->snd = snd; >> substream->sid = i; >> + init_waitqueue_head(&substream->msg_empty); >> >> rc = virtsnd_pcm_build_hw(substream, &info[i]); >> if (rc) >> @@ -530,6 +531,8 @@ void virtsnd_pcm_event(struct virtio_snd *snd, struct virtio_snd_event *event) >> break; >> } >> case VIRTIO_SND_EVT_PCM_XRUN: { >> + if (atomic_read(&substream->xfer_enabled)) >> + atomic_set(&substream->xfer_xrun, 1); >> break; >> } >> } >> diff --git a/sound/virtio/virtio_pcm.h b/sound/virtio/virtio_pcm.h >> index 73fb4d9dc524..d011b7e1d18d 100644 >> --- a/sound/virtio/virtio_pcm.h >> +++ b/sound/virtio/virtio_pcm.h >> @@ -24,6 +24,7 @@ >> #include <sound/pcm.h> >> >> struct virtio_pcm; >> +struct virtio_pcm_msg; >> >> /** >> * struct virtio_pcm_substream - VirtIO PCM substream. >> @@ -34,6 +35,16 @@ struct virtio_pcm; >> * @features: Stream VirtIO feature bit map (1 << VIRTIO_SND_PCM_F_XXX). >> * @substream: Kernel ALSA substream. >> * @hw: Kernel ALSA substream hardware descriptor. >> + * @frame_bytes: Current frame size in bytes. >> + * @period_size: Current period size in frames. >> + * @buffer_size: Current buffer size in frames. >> + * @hw_ptr: Substream hardware pointer value in frames [0 ... buffer_size). >> + * @xfer_enabled: Data transfer state (0 - off, 1 - on). >> + * @xfer_xrun: Data underflow/overflow state (0 - no xrun, 1 - xrun). >> + * @msgs: I/O messages. >> + * @msg_last_enqueued: Index of the last I/O message added to the virtqueue. >> + * @msg_count: Number of pending I/O messages in the virtqueue. >> + * @msg_empty: Notify when msg_count is zero. >> */ >> struct virtio_pcm_substream { >> struct virtio_snd *snd; >> @@ -43,6 +54,16 @@ struct virtio_pcm_substream { >> u32 features; >> struct snd_pcm_substream *substream; >> struct snd_pcm_hardware hw; >> + unsigned int frame_bytes; >> + snd_pcm_uframes_t period_size; >> + snd_pcm_uframes_t buffer_size; >> + atomic_t hw_ptr; >> + atomic_t xfer_enabled; >> + atomic_t xfer_xrun; >> + struct virtio_pcm_msg *msgs; >> + int msg_last_enqueued; >> + atomic_t msg_count; >> + wait_queue_head_t msg_empty; >> }; >> >> /** >> @@ -86,4 +107,14 @@ struct virtio_pcm *virtsnd_pcm_find(struct virtio_snd *snd, unsigned int nid); >> struct virtio_pcm *virtsnd_pcm_find_or_create(struct virtio_snd *snd, >> unsigned int nid); >> >> +struct virtio_snd_msg * >> +virtsnd_pcm_ctl_msg_alloc(struct virtio_pcm_substream *substream, >> + unsigned int command, gfp_t gfp); >> + >> +int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *substream, >> + unsigned int nmsg, u8 *dma_area, >> + unsigned int period_bytes); >> + >> +int virtsnd_pcm_msg_send(struct virtio_pcm_substream *substream); >> + >> #endif /* VIRTIO_SND_PCM_H */ >> diff --git a/sound/virtio/virtio_pcm_msg.c b/sound/virtio/virtio_pcm_msg.c >> new file mode 100644 >> index 000000000000..cfbe5935527a >> --- /dev/null >> +++ b/sound/virtio/virtio_pcm_msg.c >> @@ -0,0 +1,317 @@ >> +// 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" >> + >> +/** >> + * enum pcm_msg_sg_index - Scatter-gather element indexes for an I/O message. >> + * @PCM_MSG_SG_XFER: Element containing a virtio_snd_pcm_xfer structure. >> + * @PCM_MSG_SG_DATA: Element containing a data buffer. >> + * @PCM_MSG_SG_STATUS: Element containing a virtio_snd_pcm_status structure. >> + * @PCM_MSG_SG_MAX: The maximum number of elements in the scatter-gather table. >> + * >> + * These values are used as the index of the payload scatter-gather table. >> + */ >> +enum pcm_msg_sg_index { >> + PCM_MSG_SG_XFER = 0, >> + PCM_MSG_SG_DATA, >> + PCM_MSG_SG_STATUS, >> + PCM_MSG_SG_MAX >> +}; >> + >> +/** >> + * struct virtio_pcm_msg - VirtIO I/O message. >> + * @substream: VirtIO PCM substream. >> + * @xfer: Request header payload. >> + * @status: Response header payload. >> + * @sgs: Payload scatter-gather table. >> + */ >> +struct virtio_pcm_msg { >> + struct virtio_pcm_substream *substream; >> + struct virtio_snd_pcm_xfer xfer; >> + struct virtio_snd_pcm_status status; >> + struct scatterlist sgs[PCM_MSG_SG_MAX]; >> +}; >> + >> +/** >> + * virtsnd_pcm_msg_alloc() - Allocate I/O messages. >> + * @substream: VirtIO PCM substream. >> + * @nmsg: Number of messages (equal to the number of periods). >> + * @dma_area: Pointer to used audio buffer. >> + * @period_bytes: Period (message payload) size. >> + * >> + * The function slices the buffer into nmsg parts (each with the size of >> + * period_bytes), and creates nmsg corresponding I/O messages. >> + * >> + * Context: Any context that permits to sleep. >> + * Return: 0 on success, -ENOMEM on failure. >> + */ >> +int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *substream, >> + unsigned int nmsg, u8 *dma_area, >> + unsigned int period_bytes) >> +{ >> + struct virtio_device *vdev = substream->snd->vdev; >> + unsigned int i; >> + >> + if (substream->msgs) >> + devm_kfree(&vdev->dev, substream->msgs); >> + >> + substream->msgs = devm_kcalloc(&vdev->dev, nmsg, >> + sizeof(*substream->msgs), GFP_KERNEL); >> + if (!substream->msgs) >> + return -ENOMEM; >> + >> + for (i = 0; i < nmsg; ++i) { >> + struct virtio_pcm_msg *msg = &substream->msgs[i]; >> + >> + msg->substream = substream; >> + >> + sg_init_table(msg->sgs, PCM_MSG_SG_MAX); >> + sg_init_one(&msg->sgs[PCM_MSG_SG_XFER], &msg->xfer, >> + sizeof(msg->xfer)); >> + sg_init_one(&msg->sgs[PCM_MSG_SG_DATA], >> + dma_area + period_bytes * i, period_bytes); >> + sg_init_one(&msg->sgs[PCM_MSG_SG_STATUS], &msg->status, >> + sizeof(msg->status)); >> + } >> + >> + return 0; >> +} >> + >> +/** >> + * virtsnd_pcm_msg_send() - Send asynchronous I/O messages. >> + * @substream: VirtIO PCM substream. >> + * >> + * All messages are organized in an ordered circular list. Each time the >> + * function is called, all currently non-enqueued messages are added to the >> + * virtqueue. For this, the function keeps track of two values: >> + * >> + * msg_last_enqueued = index of the last enqueued message, >> + * msg_count = # of pending messages in the virtqueue. >> + * >> + * Context: Any context. >> + * Return: 0 on success, -EIO on failure. >> + */ >> +int virtsnd_pcm_msg_send(struct virtio_pcm_substream *substream) >> +{ >> + struct snd_pcm_runtime *runtime = substream->substream->runtime; >> + struct virtio_snd *snd = substream->snd; >> + struct virtio_device *vdev = snd->vdev; >> + struct virtqueue *vqueue = virtsnd_pcm_queue(substream)->vqueue; >> + int i; >> + int n; >> + bool notify = false; >> + >> + if (!vqueue) >> + return -EIO; >> + >> + i = (substream->msg_last_enqueued + 1) % runtime->periods; >> + n = runtime->periods - atomic_read(&substream->msg_count); >> + >> + for (; n; --n, i = (i + 1) % runtime->periods) { >> + struct virtio_pcm_msg *msg = &substream->msgs[i]; >> + struct scatterlist *psgs[PCM_MSG_SG_MAX] = { >> + [PCM_MSG_SG_XFER] = &msg->sgs[PCM_MSG_SG_XFER], >> + [PCM_MSG_SG_DATA] = &msg->sgs[PCM_MSG_SG_DATA], >> + [PCM_MSG_SG_STATUS] = &msg->sgs[PCM_MSG_SG_STATUS] >> + }; >> + int rc; >> + >> + msg->xfer.stream_id = cpu_to_virtio32(vdev, substream->sid); >> + memset(&msg->status, 0, sizeof(msg->status)); >> + >> + atomic_inc(&substream->msg_count); >> + >> + if (substream->direction == SNDRV_PCM_STREAM_PLAYBACK) >> + rc = virtqueue_add_sgs(vqueue, psgs, 2, 1, msg, >> + GFP_ATOMIC); >> + else >> + rc = virtqueue_add_sgs(vqueue, psgs, 1, 2, msg, >> + GFP_ATOMIC); >> + >> + if (rc) { >> + atomic_dec(&substream->msg_count); >> + return -EIO; >> + } >> + >> + substream->msg_last_enqueued = i; >> + } >> + >> + if (!(substream->features & (1U << VIRTIO_SND_PCM_F_MSG_POLLING))) >> + notify = virtqueue_kick_prepare(vqueue); >> + >> + if (notify) >> + if (!virtqueue_notify(vqueue)) >> + return -EIO; >> + >> + return 0; >> +} >> + >> +/** >> + * virtsnd_pcm_msg_complete() - Complete an I/O message. >> + * @msg: I/O message. >> + * @size: Number of bytes written. >> + * >> + * Completion of the message means the elapsed period: >> + * - update hardware pointer, >> + * - update latency value, >> + * - kick the upper layer. >> + * >> + * Context: Interrupt context. >> + */ >> +static void virtsnd_pcm_msg_complete(struct virtio_pcm_msg *msg, size_t size) >> +{ >> + struct virtio_pcm_substream *substream = msg->substream; >> + snd_pcm_uframes_t hw_ptr; >> + unsigned int msg_count; >> + >> + hw_ptr = (snd_pcm_uframes_t)atomic_read(&substream->hw_ptr); >> + >> + /* >> + * If the capture substream returned an incorrect status, then just >> + * increase the hw_ptr by the period size. >> + */ >> + if (substream->direction == SNDRV_PCM_STREAM_PLAYBACK || >> + size <= sizeof(msg->status)) { >> + hw_ptr += substream->period_size; >> + } else { >> + size -= sizeof(msg->status); >> + hw_ptr += size / substream->frame_bytes; >> + } >> + >> + atomic_set(&substream->hw_ptr, (u32)(hw_ptr % substream->buffer_size)); >> + atomic_set(&substream->xfer_xrun, 0); >> + >> + msg_count = atomic_dec_return(&substream->msg_count); >> + >> + if (atomic_read(&substream->xfer_enabled)) { >> + struct snd_pcm_runtime *runtime = substream->substream->runtime; >> + >> + runtime->delay = >> + bytes_to_frames(runtime, >> + le32_to_cpu(msg->status.latency_bytes)); >> + >> + snd_pcm_period_elapsed(substream->substream); >> + >> + virtsnd_pcm_msg_send(substream); >> + } else if (!msg_count) { >> + wake_up_all(&substream->msg_empty); >> + } >> +} >> + >> +/** >> + * virtsnd_pcm_notify_cb() - Process all completed I/O messages. >> + * @vqueue: Underlying tx/rx virtqueue. >> + * >> + * If transmission is allowed, then each completed message is immediately placed >> + * back at the end of the queue. >> + * >> + * Context: Interrupt context. Takes and releases the tx/rx queue spinlock. >> + */ >> +static inline void virtsnd_pcm_notify_cb(struct virtio_snd_queue *queue) >> +{ >> + unsigned long flags; >> + >> + spin_lock_irqsave(&queue->lock, flags); >> + while (queue->vqueue) { >> + virtqueue_disable_cb(queue->vqueue); >> + >> + for (;;) { >> + struct virtio_pcm_msg *msg; >> + u32 length; >> + >> + msg = virtqueue_get_buf(queue->vqueue, &length); >> + if (!msg) >> + break; >> + >> + virtsnd_pcm_msg_complete(msg, length); >> + } >> + >> + if (unlikely(virtqueue_is_broken(queue->vqueue))) >> + break; >> + >> + if (virtqueue_enable_cb(queue->vqueue)) >> + break; >> + } >> + spin_unlock_irqrestore(&queue->lock, flags); >> +} >> + >> +/** >> + * virtsnd_pcm_tx_notify_cb() - Process all completed TX messages. >> + * @vqueue: Underlying tx virtqueue. >> + * >> + * Context: Interrupt context. >> + */ >> +void virtsnd_pcm_tx_notify_cb(struct virtqueue *vqueue) >> +{ >> + struct virtio_snd *snd = vqueue->vdev->priv; >> + >> + virtsnd_pcm_notify_cb(virtsnd_tx_queue(snd)); >> +} >> + >> +/** >> + * virtsnd_pcm_rx_notify_cb() - Process all completed RX messages. >> + * @vqueue: Underlying rx virtqueue. >> + * >> + * Context: Interrupt context. >> + */ >> +void virtsnd_pcm_rx_notify_cb(struct virtqueue *vqueue) >> +{ >> + struct virtio_snd *snd = vqueue->vdev->priv; >> + >> + virtsnd_pcm_notify_cb(virtsnd_rx_queue(snd)); >> +} >> + >> +/** >> + * virtsnd_pcm_ctl_msg_alloc() - Allocate and initialize the PCM device control >> + * message for the specified substream. >> + * @substream: VirtIO PCM substream. >> + * @command: Control request code (VIRTIO_SND_R_PCM_XXX). >> + * @gfp: Kernel flags for memory allocation. >> + * >> + * Context: Any context. May sleep if @gfp flags permit. >> + * Return: Allocated message on success, ERR_PTR(-errno) on failure. >> + */ >> +struct virtio_snd_msg * >> +virtsnd_pcm_ctl_msg_alloc(struct virtio_pcm_substream *substream, >> + unsigned int command, gfp_t gfp) >> +{ >> + struct virtio_device *vdev = substream->snd->vdev; >> + size_t request_size = sizeof(struct virtio_snd_pcm_hdr); >> + size_t response_size = sizeof(struct virtio_snd_hdr); >> + struct virtio_snd_msg *msg; >> + >> + switch (command) { >> + case VIRTIO_SND_R_PCM_SET_PARAMS: { >> + request_size = sizeof(struct virtio_snd_pcm_set_params); >> + break; >> + } >> + } >> + >> + msg = virtsnd_ctl_msg_alloc(vdev, request_size, response_size, gfp); >> + if (!IS_ERR(msg)) { >> + struct virtio_snd_pcm_hdr *hdr = sg_virt(&msg->sg_request); >> + >> + hdr->hdr.code = cpu_to_virtio32(vdev, command); >> + hdr->stream_id = cpu_to_virtio32(vdev, substream->sid); >> + } >> + >> + return msg; >> +} >> -- >> 2.30.0 >> >> > >
Hi, Liam! On 20.01.2021 11:10, Girdwood, Liam R wrote: > CAUTION: This email originated from outside of the organization. > Do not click links or open attachments unless you recognize the sender and know the content is safe. > > > Hi Anton, > > On Wed, 2021-01-20 at 01:36 +0100, Anton Yakovlev wrote: >> This series implements a driver part of the virtio sound device >> specification v8 [1]. >> >> The driver supports PCM playback and capture substreams, jack and >> channel map controls. A message-based transport is used to write/read >> PCM frames to/from a device. >> >> The series is based (and was actually tested) on Linus's master >> branch [2], on top of >> >> commit 1e2a199f6ccd ("Merge tag 'spi-fix-v5.11-rc4' of ...") >> >> As a device part was used OpenSynergy proprietary implementation. >> >> Any comments are very welcome. >> > > This just looks like the guest front end here, do you have a follow up > series for the host backend ? As I mentioned in the cover message, as a device part was used our own proprietary implementation. And there are no plans to upstream that part. > Thanks > > Liam > --------------------------------------------------------------------- > Intel Corporation (UK) Limited > Registered No. 1134945 (England) > Registered Office: Pipers Way, Swindon SN3 1RJ > VAT No: 860 2173 47 > > This e-mail and any attachments may contain confidential material for > the sole use of the intended recipient(s). Any review or distribution > by others is strictly prohibited. If you are not the intended > recipient, please contact the sender and delete all copies. >