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); 118 119 /* 120 * If the substream has already been used, then the I/O queue may be in 121 * an invalid state. Just in case, we do a check and try to return the 122 * queue to its original state, if necessary. 123 */ 124 return virtsnd_pcm_sync_stop(substream); 125 } 126 127 /** 128 * virtsnd_pcm_close() - Close the PCM substream. 129 * @substream: Kernel ALSA substream. 130 * 131 * Context: Process context. 132 * Return: 0. 133 */ 134 static int virtsnd_pcm_close(struct snd_pcm_substream *substream) 135 { 136 return 0; 137 } 138 139 /** 140 * virtsnd_pcm_dev_set_params() - Set the parameters of the PCM substream on 141 * the device side. 142 * @vss: VirtIO PCM substream. 143 * @buffer_bytes: Size of the hardware buffer. 144 * @period_bytes: Size of the hardware period. 145 * @channels: Selected number of channels. 146 * @format: Selected sample format (SNDRV_PCM_FORMAT_XXX). 147 * @rate: Selected frame rate. 148 * 149 * Context: Any context that permits to sleep. 150 * Return: 0 on success, -errno on failure. 151 */ 152 static int virtsnd_pcm_dev_set_params(struct virtio_pcm_substream *vss, 153 unsigned int buffer_bytes, 154 unsigned int period_bytes, 155 unsigned int channels, 156 snd_pcm_format_t format, 157 unsigned int rate) 158 { 159 struct virtio_snd_msg *msg; 160 struct virtio_snd_pcm_set_params *request; 161 unsigned int i; 162 int vformat = -1; 163 int vrate = -1; 164 165 for (i = 0; i < ARRAY_SIZE(g_a2v_format_map); ++i) 166 if (g_a2v_format_map[i].alsa_bit == format) { 167 vformat = g_a2v_format_map[i].vio_bit; 168 169 break; 170 } 171 172 for (i = 0; i < ARRAY_SIZE(g_a2v_rate_map); ++i) 173 if (g_a2v_rate_map[i].rate == rate) { 174 vrate = g_a2v_rate_map[i].vio_bit; 175 176 break; 177 } 178 179 if (vformat == -1 || vrate == -1) 180 return -EINVAL; 181 182 msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_SET_PARAMS, 183 GFP_KERNEL); 184 if (!msg) 185 return -ENOMEM; 186 187 request = virtsnd_ctl_msg_request(msg); 188 request->buffer_bytes = cpu_to_le32(buffer_bytes); 189 request->period_bytes = cpu_to_le32(period_bytes); 190 request->channels = channels; 191 request->format = vformat; 192 request->rate = vrate; 193 194 if (vss->features & (1U << VIRTIO_SND_PCM_F_MSG_POLLING)) 195 request->features |= 196 cpu_to_le32(1U << VIRTIO_SND_PCM_F_MSG_POLLING); 197 198 if (vss->features & (1U << VIRTIO_SND_PCM_F_EVT_XRUNS)) 199 request->features |= 200 cpu_to_le32(1U << VIRTIO_SND_PCM_F_EVT_XRUNS); 201 202 return virtsnd_ctl_msg_send_sync(vss->snd, msg); 203 } 204 205 /** 206 * virtsnd_pcm_hw_params() - Set the parameters of the PCM substream. 207 * @substream: Kernel ALSA substream. 208 * @hw_params: Hardware parameters. 209 * 210 * Context: Process context. 211 * Return: 0 on success, -errno on failure. 212 */ 213 static int virtsnd_pcm_hw_params(struct snd_pcm_substream *substream, 214 struct snd_pcm_hw_params *hw_params) 215 { 216 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 217 struct virtio_device *vdev = vss->snd->vdev; 218 int rc; 219 220 if (virtsnd_pcm_msg_pending_num(vss)) { 221 dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n", 222 vss->sid); 223 return -EBADFD; 224 } 225 226 rc = virtsnd_pcm_dev_set_params(vss, params_buffer_bytes(hw_params), 227 params_period_bytes(hw_params), 228 params_channels(hw_params), 229 params_format(hw_params), 230 params_rate(hw_params)); 231 if (rc) 232 return rc; 233 234 /* 235 * Free previously allocated messages if ops->hw_params() is called 236 * several times in a row, or if ops->hw_free() failed to free messages. 237 */ 238 virtsnd_pcm_msg_free(vss); 239 240 return virtsnd_pcm_msg_alloc(vss, params_periods(hw_params), 241 params_period_bytes(hw_params)); 242 } 243 244 /** 245 * virtsnd_pcm_hw_free() - Reset the parameters of the PCM substream. 246 * @substream: Kernel ALSA substream. 247 * 248 * Context: Process context. 249 * Return: 0 250 */ 251 static int virtsnd_pcm_hw_free(struct snd_pcm_substream *substream) 252 { 253 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 254 255 /* If the queue is flushed, we can safely free the messages here. */ 256 if (!virtsnd_pcm_msg_pending_num(vss)) 257 virtsnd_pcm_msg_free(vss); 258 259 return 0; 260 } 261 262 /** 263 * virtsnd_pcm_prepare() - Prepare the PCM substream. 264 * @substream: Kernel ALSA substream. 265 * 266 * Context: Process context. 267 * Return: 0 on success, -errno on failure. 268 */ 269 static int virtsnd_pcm_prepare(struct snd_pcm_substream *substream) 270 { 271 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 272 struct virtio_device *vdev = vss->snd->vdev; 273 struct virtio_snd_msg *msg; 274 275 if (virtsnd_pcm_msg_pending_num(vss)) { 276 dev_err(&vdev->dev, "SID %u: invalid I/O queue state\n", 277 vss->sid); 278 return -EBADFD; 279 } 280 281 vss->buffer_bytes = snd_pcm_lib_buffer_bytes(substream); 282 vss->hw_ptr = 0; 283 vss->xfer_xrun = false; 284 vss->msg_last_enqueued = -1; 285 vss->msg_count = 0; 286 287 msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_PREPARE, 288 GFP_KERNEL); 289 if (!msg) 290 return -ENOMEM; 291 292 return virtsnd_ctl_msg_send_sync(vss->snd, msg); 293 } 294 295 /** 296 * virtsnd_pcm_trigger() - Process command for the PCM substream. 297 * @substream: Kernel ALSA substream. 298 * @command: Substream command (SNDRV_PCM_TRIGGER_XXX). 299 * 300 * Context: Any context. Takes and releases the VirtIO substream spinlock. 301 * May take and release the tx/rx queue spinlock. 302 * Return: 0 on success, -errno on failure. 303 */ 304 static int virtsnd_pcm_trigger(struct snd_pcm_substream *substream, int command) 305 { 306 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 307 struct virtio_snd *snd = vss->snd; 308 struct virtio_snd_queue *queue; 309 struct virtio_snd_msg *msg; 310 unsigned long flags; 311 int rc; 312 313 switch (command) { 314 case SNDRV_PCM_TRIGGER_START: 315 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 316 queue = virtsnd_pcm_queue(vss); 317 318 spin_lock_irqsave(&queue->lock, flags); 319 spin_lock(&vss->lock); 320 rc = virtsnd_pcm_msg_send(vss); 321 if (!rc) 322 vss->xfer_enabled = true; 323 spin_unlock(&vss->lock); 324 spin_unlock_irqrestore(&queue->lock, flags); 325 if (rc) 326 return rc; 327 328 msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_START, 329 GFP_KERNEL); 330 if (!msg) { 331 spin_lock_irqsave(&vss->lock, flags); 332 vss->xfer_enabled = false; 333 spin_unlock_irqrestore(&vss->lock, flags); 334 335 return -ENOMEM; 336 } 337 338 return virtsnd_ctl_msg_send_sync(snd, msg); 339 case SNDRV_PCM_TRIGGER_STOP: 340 vss->stopped = true; 341 fallthrough; 342 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 343 spin_lock_irqsave(&vss->lock, flags); 344 vss->xfer_enabled = false; 345 spin_unlock_irqrestore(&vss->lock, flags); 346 347 msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_STOP, 348 GFP_KERNEL); 349 if (!msg) 350 return -ENOMEM; 351 352 return virtsnd_ctl_msg_send_sync(snd, msg); 353 default: 354 return -EINVAL; 355 } 356 } 357 358 /** 359 * virtsnd_pcm_sync_stop() - Synchronous PCM substream stop. 360 * @substream: Kernel ALSA substream. 361 * 362 * The function can be called both from the upper level or from the driver 363 * itself. 364 * 365 * Context: Process context. Takes and releases the VirtIO substream spinlock. 366 * Return: 0 on success, -errno on failure. 367 */ 368 static int virtsnd_pcm_sync_stop(struct snd_pcm_substream *substream) 369 { 370 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 371 struct virtio_snd *snd = vss->snd; 372 struct virtio_snd_msg *msg; 373 unsigned int js = msecs_to_jiffies(virtsnd_msg_timeout_ms); 374 int rc; 375 376 cancel_work_sync(&vss->elapsed_period); 377 378 if (!vss->stopped) 379 return 0; 380 381 msg = virtsnd_pcm_ctl_msg_alloc(vss, VIRTIO_SND_R_PCM_RELEASE, 382 GFP_KERNEL); 383 if (!msg) 384 return -ENOMEM; 385 386 rc = virtsnd_ctl_msg_send_sync(snd, msg); 387 if (rc) 388 return rc; 389 390 /* 391 * The spec states that upon receipt of the RELEASE command "the device 392 * MUST complete all pending I/O messages for the specified stream ID". 393 * Thus, we consider the absence of I/O messages in the queue as an 394 * indication that the substream has been released. 395 */ 396 rc = wait_event_interruptible_timeout(vss->msg_empty, 397 !virtsnd_pcm_msg_pending_num(vss), 398 js); 399 if (rc <= 0) { 400 dev_warn(&snd->vdev->dev, "SID %u: failed to flush I/O queue\n", 401 vss->sid); 402 403 return !rc ? -ETIMEDOUT : rc; 404 } 405 406 vss->stopped = false; 407 408 return 0; 409 } 410 411 /** 412 * virtsnd_pcm_pointer() - Get the current hardware position for the PCM 413 * substream. 414 * @substream: Kernel ALSA substream. 415 * 416 * Context: Any context. Takes and releases the VirtIO substream spinlock. 417 * Return: Hardware position in frames inside [0 ... buffer_size) range. 418 */ 419 static snd_pcm_uframes_t 420 virtsnd_pcm_pointer(struct snd_pcm_substream *substream) 421 { 422 struct virtio_pcm_substream *vss = snd_pcm_substream_chip(substream); 423 snd_pcm_uframes_t hw_ptr = SNDRV_PCM_POS_XRUN; 424 unsigned long flags; 425 426 spin_lock_irqsave(&vss->lock, flags); 427 if (!vss->xfer_xrun) 428 hw_ptr = bytes_to_frames(substream->runtime, vss->hw_ptr); 429 spin_unlock_irqrestore(&vss->lock, flags); 430 431 return hw_ptr; 432 } 433 434 /* PCM substream operators map. */ 435 const struct snd_pcm_ops virtsnd_pcm_ops = { 436 .open = virtsnd_pcm_open, 437 .close = virtsnd_pcm_close, 438 .ioctl = snd_pcm_lib_ioctl, 439 .hw_params = virtsnd_pcm_hw_params, 440 .hw_free = virtsnd_pcm_hw_free, 441 .prepare = virtsnd_pcm_prepare, 442 .trigger = virtsnd_pcm_trigger, 443 .sync_stop = virtsnd_pcm_sync_stop, 444 .pointer = virtsnd_pcm_pointer, 445 }; 446