1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * virtio-snd: Virtio sound device 4 * Copyright (C) 2021 OpenSynergy GmbH 5 */ 6 #include <sound/pcm_params.h> 7 8 #include "virtio_card.h" 9 10 /* 11 * I/O messages lifetime 12 * --------------------- 13 * 14 * Allocation: 15 * Messages are initially allocated in the ops->hw_params() after the size and 16 * number of periods have been successfully negotiated. 17 * 18 * Freeing: 19 * Messages can be safely freed after the queue has been successfully flushed 20 * (RELEASE command in the ops->sync_stop()) and the ops->hw_free() has been 21 * called. 22 * 23 * When the substream stops, the ops->sync_stop() waits until the device has 24 * completed all pending messages. This wait can be interrupted either by a 25 * signal or due to a timeout. In this case, the device can still access 26 * messages even after calling ops->hw_free(). It can also issue an interrupt, 27 * and the interrupt handler will also try to access message structures. 28 * 29 * Therefore, freeing of already allocated messages occurs: 30 * 31 * - in ops->hw_params(), if this operator was called several times in a row, 32 * or if ops->hw_free() failed to free messages previously; 33 * 34 * - in ops->hw_free(), if the queue has been successfully flushed; 35 * 36 * - in dev->release(). 37 */ 38 39 /* Map for converting ALSA format to VirtIO format. */ 40 struct virtsnd_a2v_format { 41 snd_pcm_format_t alsa_bit; 42 unsigned int vio_bit; 43 }; 44 45 static const struct virtsnd_a2v_format g_a2v_format_map[] = { 46 { SNDRV_PCM_FORMAT_IMA_ADPCM, VIRTIO_SND_PCM_FMT_IMA_ADPCM }, 47 { SNDRV_PCM_FORMAT_MU_LAW, VIRTIO_SND_PCM_FMT_MU_LAW }, 48 { SNDRV_PCM_FORMAT_A_LAW, VIRTIO_SND_PCM_FMT_A_LAW }, 49 { SNDRV_PCM_FORMAT_S8, VIRTIO_SND_PCM_FMT_S8 }, 50 { SNDRV_PCM_FORMAT_U8, VIRTIO_SND_PCM_FMT_U8 }, 51 { SNDRV_PCM_FORMAT_S16_LE, VIRTIO_SND_PCM_FMT_S16 }, 52 { SNDRV_PCM_FORMAT_U16_LE, VIRTIO_SND_PCM_FMT_U16 }, 53 { SNDRV_PCM_FORMAT_S18_3LE, VIRTIO_SND_PCM_FMT_S18_3 }, 54 { SNDRV_PCM_FORMAT_U18_3LE, VIRTIO_SND_PCM_FMT_U18_3 }, 55 { SNDRV_PCM_FORMAT_S20_3LE, VIRTIO_SND_PCM_FMT_S20_3 }, 56 { SNDRV_PCM_FORMAT_U20_3LE, VIRTIO_SND_PCM_FMT_U20_3 }, 57 { SNDRV_PCM_FORMAT_S24_3LE, VIRTIO_SND_PCM_FMT_S24_3 }, 58 { SNDRV_PCM_FORMAT_U24_3LE, VIRTIO_SND_PCM_FMT_U24_3 }, 59 { SNDRV_PCM_FORMAT_S20_LE, VIRTIO_SND_PCM_FMT_S20 }, 60 { SNDRV_PCM_FORMAT_U20_LE, VIRTIO_SND_PCM_FMT_U20 }, 61 { SNDRV_PCM_FORMAT_S24_LE, VIRTIO_SND_PCM_FMT_S24 }, 62 { SNDRV_PCM_FORMAT_U24_LE, VIRTIO_SND_PCM_FMT_U24 }, 63 { SNDRV_PCM_FORMAT_S32_LE, VIRTIO_SND_PCM_FMT_S32 }, 64 { SNDRV_PCM_FORMAT_U32_LE, VIRTIO_SND_PCM_FMT_U32 }, 65 { SNDRV_PCM_FORMAT_FLOAT_LE, VIRTIO_SND_PCM_FMT_FLOAT }, 66 { SNDRV_PCM_FORMAT_FLOAT64_LE, VIRTIO_SND_PCM_FMT_FLOAT64 }, 67 { SNDRV_PCM_FORMAT_DSD_U8, VIRTIO_SND_PCM_FMT_DSD_U8 }, 68 { SNDRV_PCM_FORMAT_DSD_U16_LE, VIRTIO_SND_PCM_FMT_DSD_U16 }, 69 { SNDRV_PCM_FORMAT_DSD_U32_LE, VIRTIO_SND_PCM_FMT_DSD_U32 }, 70 { SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE, 71 VIRTIO_SND_PCM_FMT_IEC958_SUBFRAME } 72 }; 73 74 /* Map for converting ALSA frame rate to VirtIO frame rate. */ 75 struct virtsnd_a2v_rate { 76 unsigned int rate; 77 unsigned int vio_bit; 78 }; 79 80 static const struct virtsnd_a2v_rate g_a2v_rate_map[] = { 81 { 5512, VIRTIO_SND_PCM_RATE_5512 }, 82 { 8000, VIRTIO_SND_PCM_RATE_8000 }, 83 { 11025, VIRTIO_SND_PCM_RATE_11025 }, 84 { 16000, VIRTIO_SND_PCM_RATE_16000 }, 85 { 22050, VIRTIO_SND_PCM_RATE_22050 }, 86 { 32000, VIRTIO_SND_PCM_RATE_32000 }, 87 { 44100, VIRTIO_SND_PCM_RATE_44100 }, 88 { 48000, VIRTIO_SND_PCM_RATE_48000 }, 89 { 64000, VIRTIO_SND_PCM_RATE_64000 }, 90 { 88200, VIRTIO_SND_PCM_RATE_88200 }, 91 { 96000, VIRTIO_SND_PCM_RATE_96000 }, 92 { 176400, VIRTIO_SND_PCM_RATE_176400 }, 93 { 192000, VIRTIO_SND_PCM_RATE_192000 } 94 }; 95 96 static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream); 97 98 /** 99 * virtsnd_pcm_open() - Open the PCM substream. 100 * @substream: Kernel ALSA substream. 101 * 102 * Context: Process context. 103 * Return: 0 on success, -errno on failure. 104 */ 105 static int virtsnd_pcm_open(struct snd_pcm_substream *substream) 106 { 107 struct virtio_pcm *vpcm = snd_pcm_substream_chip(substream); 108 struct virtio_pcm_stream *vs = &vpcm->streams[substream->stream]; 109 struct virtio_pcm_substream *vss = vs->substreams[substream->number]; 110 111 substream->runtime->hw = vss->hw; 112 substream->private_data = vss; 113 114 snd_pcm_hw_constraint_integer(substream->runtime, 115 SNDRV_PCM_HW_PARAM_PERIODS); 116 117 vss->stopped = !!virtsnd_pcm_msg_pending_num(vss); 118 vss->suspended = false; 119 120 /* 121 * If the substream has already been used, then the I/O queue may be in 122 * an invalid state. Just in case, we do a check and try to return the 123 * queue to its original state, if necessary. 124 */ 125 return virtsnd_pcm_sync_stop(substream); 126 } 127 128 /** 129 * virtsnd_pcm_close() - Close the PCM substream. 130 * @substream: Kernel ALSA substream. 131 * 132 * Context: Process context. 133 * Return: 0. 134 */ 135 static int virtsnd_pcm_close(struct snd_pcm_substream *substream) 136 { 137 return 0; 138 } 139 140 /** 141 * virtsnd_pcm_dev_set_params() - Set the parameters of the PCM substream on 142 * the device side. 143 * @vss: VirtIO PCM substream. 144 * @buffer_bytes: Size of the hardware buffer. 145 * @period_bytes: Size of the hardware period. 146 * @channels: Selected number of channels. 147 * @format: Selected sample format (SNDRV_PCM_FORMAT_XXX). 148 * @rate: Selected frame rate. 149 * 150 * Context: Any context that permits to sleep. 151 * Return: 0 on success, -errno on failure. 152 */ 153 static int virtsnd_pcm_dev_set_params(struct virtio_pcm_substream *vss, 154 unsigned int buffer_bytes, 155 unsigned int period_bytes, 156 unsigned int channels, 157 snd_pcm_format_t format, 158 unsigned int rate) 159 { 160 struct virtio_snd_msg *msg; 161 struct virtio_snd_pcm_set_params *request; 162 unsigned int i; 163 int vformat = -1; 164 int vrate = -1; 165 166 for (i = 0; i < ARRAY_SIZE(g_a2v_format_map); ++i) 167 if (g_a2v_format_map[i].alsa_bit == format) { 168 vformat = g_a2v_format_map[i].vio_bit; 169 170 break; 171 } 172 173 for (i = 0; i < ARRAY_SIZE(g_a2v_rate_map); ++i) 174 if (g_a2v_rate_map[i].rate == rate) { 175 vrate = g_a2v_rate_map[i].vio_bit; 176 177 break; 178 } 179 180 if (vformat == -1 || vrate == -1) 181 return -EINVAL; 182 183 msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_SET_PARAMS, 184 GFP_KERNEL); 185 if (!msg) 186 return -ENOMEM; 187 188 request = virtsnd_ctl_msg_request(msg); 189 request->buffer_bytes = cpu_to_le32(buffer_bytes); 190 request->period_bytes = cpu_to_le32(period_bytes); 191 request->channels = channels; 192 request->format = vformat; 193 request->rate = vrate; 194 195 if (vss->features & (1U << VIRTIO_SND_PCM_F_MSG_POLLING)) 196 request->features |= 197 cpu_to_le32(1U << VIRTIO_SND_PCM_F_MSG_POLLING); 198 199 if (vss->features & (1U << VIRTIO_SND_PCM_F_EVT_XRUNS)) 200 request->features |= 201 cpu_to_le32(1U << VIRTIO_SND_PCM_F_EVT_XRUNS); 202 203 return virtsnd_ctl_msg_send_sync(vss->snd, msg); 204 } 205 206 /** 207 * virtsnd_pcm_hw_params() - Set the parameters of the PCM substream. 208 * @substream: Kernel ALSA substream. 209 * @hw_params: Hardware parameters. 210 * 211 * Context: Process context. 212 * Return: 0 on success, -errno on failure. 213 */ 214 static int virtsnd_pcm_hw_params(struct snd_pcm_substream *substream, 215 struct snd_pcm_hw_params *hw_params) 216 { 217 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 218 struct virtio_device *vdev = vss->snd->vdev; 219 int rc; 220 221 if (virtsnd_pcm_msg_pending_num(vss)) { 222 dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n", 223 vss->sid); 224 return -EBADFD; 225 } 226 227 rc = virtsnd_pcm_dev_set_params(vss, params_buffer_bytes(hw_params), 228 params_period_bytes(hw_params), 229 params_channels(hw_params), 230 params_format(hw_params), 231 params_rate(hw_params)); 232 if (rc) 233 return rc; 234 235 /* 236 * Free previously allocated messages if ops->hw_params() is called 237 * several times in a row, or if ops->hw_free() failed to free messages. 238 */ 239 virtsnd_pcm_msg_free(vss); 240 241 return virtsnd_pcm_msg_alloc(vss, params_periods(hw_params), 242 params_period_bytes(hw_params)); 243 } 244 245 /** 246 * virtsnd_pcm_hw_free() - Reset the parameters of the PCM substream. 247 * @substream: Kernel ALSA substream. 248 * 249 * Context: Process context. 250 * Return: 0 251 */ 252 static int virtsnd_pcm_hw_free(struct snd_pcm_substream *substream) 253 { 254 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 255 256 /* If the queue is flushed, we can safely free the messages here. */ 257 if (!virtsnd_pcm_msg_pending_num(vss)) 258 virtsnd_pcm_msg_free(vss); 259 260 return 0; 261 } 262 263 /** 264 * virtsnd_pcm_prepare() - Prepare the PCM substream. 265 * @substream: Kernel ALSA substream. 266 * 267 * Context: Process context. 268 * Return: 0 on success, -errno on failure. 269 */ 270 static int virtsnd_pcm_prepare(struct snd_pcm_substream *substream) 271 { 272 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 273 struct virtio_device *vdev = vss->snd->vdev; 274 struct virtio_snd_msg *msg; 275 276 if (!vss->suspended) { 277 if (virtsnd_pcm_msg_pending_num(vss)) { 278 dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n", 279 vss->sid); 280 return -EBADFD; 281 } 282 283 vss->buffer_bytes = snd_pcm_lib_buffer_bytes(substream); 284 vss->hw_ptr = 0; 285 vss->msg_last_enqueued = -1; 286 } else { 287 struct snd_pcm_runtime *runtime = substream->runtime; 288 unsigned int buffer_bytes = snd_pcm_lib_buffer_bytes(substream); 289 unsigned int period_bytes = snd_pcm_lib_period_bytes(substream); 290 int rc; 291 292 rc = virtsnd_pcm_dev_set_params(vss, buffer_bytes, period_bytes, 293 runtime->channels, 294 runtime->format, runtime->rate); 295 if (rc) 296 return rc; 297 } 298 299 vss->xfer_xrun = false; 300 vss->suspended = false; 301 vss->msg_count = 0; 302 303 msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_PREPARE, 304 GFP_KERNEL); 305 if (!msg) 306 return -ENOMEM; 307 308 return virtsnd_ctl_msg_send_sync(vss->snd, msg); 309 } 310 311 /** 312 * virtsnd_pcm_trigger() - Process command for the PCM substream. 313 * @substream: Kernel ALSA substream. 314 * @command: Substream command (SNDRV_PCM_TRIGGER_XXX). 315 * 316 * Context: Any context. Takes and releases the VirtIO substream spinlock. 317 * May take and release the tx/rx queue spinlock. 318 * Return: 0 on success, -errno on failure. 319 */ 320 static int virtsnd_pcm_trigger(struct snd_pcm_substream *substream, int command) 321 { 322 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 323 struct virtio_snd *snd = vss->snd; 324 struct virtio_snd_queue *queue; 325 struct virtio_snd_msg *msg; 326 unsigned long flags; 327 int rc; 328 329 switch (command) { 330 case SNDRV_PCM_TRIGGER_START: 331 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 332 queue = virtsnd_pcm_queue(vss); 333 334 spin_lock_irqsave(&queue->lock, flags); 335 spin_lock(&vss->lock); 336 rc = virtsnd_pcm_msg_send(vss); 337 if (!rc) 338 vss->xfer_enabled = true; 339 spin_unlock(&vss->lock); 340 spin_unlock_irqrestore(&queue->lock, flags); 341 if (rc) 342 return rc; 343 344 msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_START, 345 GFP_KERNEL); 346 if (!msg) { 347 spin_lock_irqsave(&vss->lock, flags); 348 vss->xfer_enabled = false; 349 spin_unlock_irqrestore(&vss->lock, flags); 350 351 return -ENOMEM; 352 } 353 354 return virtsnd_ctl_msg_send_sync(snd, msg); 355 case SNDRV_PCM_TRIGGER_SUSPEND: 356 vss->suspended = true; 357 fallthrough; 358 case SNDRV_PCM_TRIGGER_STOP: 359 vss->stopped = true; 360 fallthrough; 361 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 362 spin_lock_irqsave(&vss->lock, flags); 363 vss->xfer_enabled = false; 364 spin_unlock_irqrestore(&vss->lock, flags); 365 366 msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_STOP, 367 GFP_KERNEL); 368 if (!msg) 369 return -ENOMEM; 370 371 return virtsnd_ctl_msg_send_sync(snd, msg); 372 default: 373 return -EINVAL; 374 } 375 } 376 377 /** 378 * virtsnd_pcm_sync_stop() - Synchronous PCM substream stop. 379 * @substream: Kernel ALSA substream. 380 * 381 * The function can be called both from the upper level or from the driver 382 * itself. 383 * 384 * Context: Process context. Takes and releases the VirtIO substream spinlock. 385 * Return: 0 on success, -errno on failure. 386 */ 387 static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream) 388 { 389 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 390 struct virtio_snd *snd = vss->snd; 391 struct virtio_snd_msg *msg; 392 unsigned int js = msecs_to_jiffies(virtsnd_msg_timeout_ms); 393 int rc; 394 395 cancel_work_sync(&vss->elapsed_period); 396 397 if (!vss->stopped) 398 return 0; 399 400 msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_RELEASE, 401 GFP_KERNEL); 402 if (!msg) 403 return -ENOMEM; 404 405 rc = virtsnd_ctl_msg_send_sync(snd, msg); 406 if (rc) 407 return rc; 408 409 /* 410 * The spec states that upon receipt of the RELEASE command "the device 411 * MUST complete all pending I/O messages for the specified stream ID". 412 * Thus, we consider the absence of I/O messages in the queue as an 413 * indication that the substream has been released. 414 */ 415 rc = wait_event_interruptible_timeout(vss->msg_empty, 416 !virtsnd_pcm_msg_pending_num(vss), 417 js); 418 if (rc <= 0) { 419 dev_warn(&snd->vdev->dev, "SID %u: failed to flush I/O queue\n", 420 vss->sid); 421 422 return !rc ? -ETIMEDOUT : rc; 423 } 424 425 vss->stopped = false; 426 427 return 0; 428 } 429 430 /** 431 * virtsnd_pcm_pointer() - Get the current hardware position for the PCM 432 * substream. 433 * @substream: Kernel ALSA substream. 434 * 435 * Context: Any context. Takes and releases the VirtIO substream spinlock. 436 * Return: Hardware position in frames inside [0 ... buffer_size) range. 437 */ 438 static snd_pcm_uframes_t 439 virtsnd_pcm_pointer(struct snd_pcm_substream *substream) 440 { 441 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 442 snd_pcm_uframes_t hw_ptr = SNDRV_PCM_POS_XRUN; 443 unsigned long flags; 444 445 spin_lock_irqsave(&vss->lock, flags); 446 if (!vss->xfer_xrun) 447 hw_ptr = bytes_to_frames(substream->runtime, vss->hw_ptr); 448 spin_unlock_irqrestore(&vss->lock, flags); 449 450 return hw_ptr; 451 } 452 453 /* PCM substream operators map. */ 454 const struct snd_pcm_ops virtsnd_pcm_ops = { 455 .open = virtsnd_pcm_open, 456 .close = virtsnd_pcm_close, 457 .ioctl = snd_pcm_lib_ioctl, 458 .hw_params = virtsnd_pcm_hw_params, 459 .hw_free = virtsnd_pcm_hw_free, 460 .prepare = virtsnd_pcm_prepare, 461 .trigger = virtsnd_pcm_trigger, 462 .sync_stop = virtsnd_pcm_sync_stop, 463 .pointer = virtsnd_pcm_pointer, 464 }; 465