// SPDX-License-Identifier: GPL-2.0+ /* * virtio-snd: Virtio sound device * Copyright (C) 2021 OpenSynergy GmbH */ #include #include "virtio_card.h" /* * I/O messages lifetime * --------------------- * * Allocation: * Messages are initially allocated in the ops->hw_params() after the size and * number of periods have been successfully negotiated. * * Freeing: * Messages can be safely freed after the queue has been successfully flushed * (RELEASE command in the ops->sync_stop()) and the ops->hw_free() has been * called. * * When the substream stops, the ops->sync_stop() waits until the device has * completed all pending messages. This wait can be interrupted either by a * signal or due to a timeout. In this case, the device can still access * messages even after calling ops->hw_free(). It can also issue an interrupt, * and the interrupt handler will also try to access message structures. * * Therefore, freeing of already allocated messages occurs: * * - in ops->hw_params(), if this operator was called several times in a row, * or if ops->hw_free() failed to free messages previously; * * - in ops->hw_free(), if the queue has been successfully flushed; * * - in dev->release(). */ /* Map for converting ALSA format to VirtIO format. */ struct virtsnd_a2v_format { snd_pcm_format_t 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 } }; static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream); /** * virtsnd_pcm_open() - Open the PCM substream. * @substream: Kernel ALSA substream. * * Context: Process context. * Return: 0 on success, -errno on failure. */ static int virtsnd_pcm_open(struct snd_pcm_substream *substream) { struct virtio_pcm *vpcm = snd_pcm_substream_chip(substream); struct virtio_pcm_stream *vs = &vpcm->streams[substream->stream]; struct virtio_pcm_substream *vss = vs->substreams[substream->number]; substream->runtime->hw = vss->hw; substream->private_data = vss; snd_pcm_hw_constraint_integer(substream->runtime, SNDRV_PCM_HW_PARAM_PERIODS); vss->stopped = !!virtsnd_pcm_msg_pending_num(vss); vss->suspended = false; /* * If the substream has already been used, then the I/O queue may be in * an invalid state. Just in case, we do a check and try to return the * queue to its original state, if necessary. */ return virtsnd_pcm_sync_stop(substream); } /** * virtsnd_pcm_close() - Close the PCM substream. * @substream: Kernel ALSA substream. * * Context: Process context. * Return: 0. */ static int virtsnd_pcm_close(struct snd_pcm_substream *substream) { return 0; } /** * virtsnd_pcm_dev_set_params() - Set the parameters of the PCM substream on * the device side. * @vss: VirtIO PCM substream. * @buffer_bytes: Size of the hardware buffer. * @period_bytes: Size of the hardware period. * @channels: Selected number of channels. * @format: Selected sample format (SNDRV_PCM_FORMAT_XXX). * @rate: Selected frame rate. * * Context: Any context that permits to sleep. * Return: 0 on success, -errno on failure. */ static int virtsnd_pcm_dev_set_params(struct virtio_pcm_substream *vss, unsigned int buffer_bytes, unsigned int period_bytes, unsigned int channels, snd_pcm_format_t format, unsigned int rate) { struct virtio_snd_msg *msg; struct virtio_snd_pcm_set_params *request; unsigned int i; int vformat = -1; int vrate = -1; 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(vss, VIRTIO_SND_R_PCM_SET_PARAMS, GFP_KERNEL); if (!msg) return -ENOMEM; request = virtsnd_ctl_msg_request(msg); request->buffer_bytes = cpu_to_le32(buffer_bytes); request->period_bytes = cpu_to_le32(period_bytes); request->channels = channels; request->format = vformat; request->rate = vrate; if (vss->features & (1U << VIRTIO_SND_PCM_F_MSG_POLLING)) request->features |= cpu_to_le32(1U << VIRTIO_SND_PCM_F_MSG_POLLING); if (vss->features & (1U << VIRTIO_SND_PCM_F_EVT_XRUNS)) request->features |= cpu_to_le32(1U << VIRTIO_SND_PCM_F_EVT_XRUNS); return virtsnd_ctl_msg_send_sync(vss->snd, msg); } /** * virtsnd_pcm_hw_params() - Set the parameters of the PCM substream. * @substream: Kernel ALSA substream. * @hw_params: Hardware parameters. * * Context: Process context. * 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 virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); struct virtio_device *vdev = vss->snd->vdev; int rc; if (virtsnd_pcm_msg_pending_num(vss)) { dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n", vss->sid); return -EBADFD; } rc = virtsnd_pcm_dev_set_params(vss, params_buffer_bytes(hw_params), params_period_bytes(hw_params), params_channels(hw_params), params_format(hw_params), params_rate(hw_params)); if (rc) return rc; /* * Free previously allocated messages if ops->hw_params() is called * several times in a row, or if ops->hw_free() failed to free messages. */ virtsnd_pcm_msg_free(vss); return virtsnd_pcm_msg_alloc(vss, params_periods(hw_params), params_period_bytes(hw_params)); } /** * virtsnd_pcm_hw_free() - Reset the parameters of the PCM substream. * @substream: Kernel ALSA substream. * * Context: Process context. * Return: 0 */ static int virtsnd_pcm_hw_free(struct snd_pcm_substream *substream) { struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); /* If the queue is flushed, we can safely free the messages here. */ if (!virtsnd_pcm_msg_pending_num(vss)) virtsnd_pcm_msg_free(vss); return 0; } /** * virtsnd_pcm_prepare() - Prepare the PCM substream. * @substream: Kernel ALSA substream. * * Context: Process context. * Return: 0 on success, -errno on failure. */ static int virtsnd_pcm_prepare(struct snd_pcm_substream *substream) { struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); struct virtio_device *vdev = vss->snd->vdev; struct virtio_snd_msg *msg; if (!vss->suspended) { if (virtsnd_pcm_msg_pending_num(vss)) { dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n", vss->sid); return -EBADFD; } vss->buffer_bytes = snd_pcm_lib_buffer_bytes(substream); vss->hw_ptr = 0; vss->msg_last_enqueued = -1; } else { struct snd_pcm_runtime *runtime = substream->runtime; unsigned int buffer_bytes = snd_pcm_lib_buffer_bytes(substream); unsigned int period_bytes = snd_pcm_lib_period_bytes(substream); int rc; rc = virtsnd_pcm_dev_set_params(vss, buffer_bytes, period_bytes, runtime->channels, runtime->format, runtime->rate); if (rc) return rc; } vss->xfer_xrun = false; vss->suspended = false; vss->msg_count = 0; msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_PREPARE, GFP_KERNEL); if (!msg) return -ENOMEM; return virtsnd_ctl_msg_send_sync(vss->snd, msg); } /** * virtsnd_pcm_trigger() - Process command for the PCM substream. * @substream: Kernel ALSA substream. * @command: Substream command (SNDRV_PCM_TRIGGER_XXX). * * Context: Any context. Takes and releases the VirtIO substream spinlock. * 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 *vss = snd_pcm_substream_chip(substream); struct virtio_snd *snd = vss->snd; struct virtio_snd_queue *queue; struct virtio_snd_msg *msg; unsigned long flags; int rc; switch (command) { case SNDRV_PCM_TRIGGER_START: case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: queue = virtsnd_pcm_queue(vss); spin_lock_irqsave(&queue->lock, flags); spin_lock(&vss->lock); rc = virtsnd_pcm_msg_send(vss); if (!rc) vss->xfer_enabled = true; spin_unlock(&vss->lock); spin_unlock_irqrestore(&queue->lock, flags); if (rc) return rc; msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_START, GFP_KERNEL); if (!msg) { spin_lock_irqsave(&vss->lock, flags); vss->xfer_enabled = false; spin_unlock_irqrestore(&vss->lock, flags); return -ENOMEM; } return virtsnd_ctl_msg_send_sync(snd, msg); case SNDRV_PCM_TRIGGER_SUSPEND: vss->suspended = true; fallthrough; case SNDRV_PCM_TRIGGER_STOP: vss->stopped = true; fallthrough; case SNDRV_PCM_TRIGGER_PAUSE_PUSH: spin_lock_irqsave(&vss->lock, flags); vss->xfer_enabled = false; spin_unlock_irqrestore(&vss->lock, flags); msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_STOP, GFP_KERNEL); if (!msg) return -ENOMEM; return virtsnd_ctl_msg_send_sync(snd, msg); default: return -EINVAL; } } /** * virtsnd_pcm_sync_stop() - Synchronous PCM substream stop. * @substream: Kernel ALSA substream. * * The function can be called both from the upper level or from the driver * itself. * * Context: Process context. Takes and releases the VirtIO substream spinlock. * Return: 0 on success, -errno on failure. */ static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream) { struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); struct virtio_snd *snd = vss->snd; struct virtio_snd_msg *msg; unsigned int js = msecs_to_jiffies(virtsnd_msg_timeout_ms); int rc; cancel_work_sync(&vss->elapsed_period); if (!vss->stopped) return 0; msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_RELEASE, GFP_KERNEL); if (!msg) return -ENOMEM; rc = virtsnd_ctl_msg_send_sync(snd, msg); if (rc) return rc; /* * 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. */ rc = wait_event_interruptible_timeout(vss->msg_empty, !virtsnd_pcm_msg_pending_num(vss), js); if (rc <= 0) { dev_warn(&snd->vdev->dev, "SID %u: failed to flush I/O queue\n", vss->sid); return !rc ? -ETIMEDOUT : rc; } vss->stopped = false; return 0; } /** * virtsnd_pcm_pointer() - Get the current hardware position for the PCM * substream. * @substream: Kernel ALSA substream. * * Context: Any context. Takes and releases the VirtIO substream spinlock. * 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 *vss = snd_pcm_substream_chip(substream); snd_pcm_uframes_t hw_ptr = SNDRV_PCM_POS_XRUN; unsigned long flags; spin_lock_irqsave(&vss->lock, flags); if (!vss->xfer_xrun) hw_ptr = bytes_to_frames(substream->runtime, vss->hw_ptr); spin_unlock_irqrestore(&vss->lock, flags); return 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, .sync_stop = virtsnd_pcm_sync_stop, .pointer = virtsnd_pcm_pointer, };