sound/xen/xen_snd_front_alsa.c

   1 // SPDX-License-Identifier: GPL-2.0 OR MIT
   2
   3 /*
   4  * Xen para-virtual sound device
   5  *
   6  * Copyright (C) 2016-2018 EPAM Systems Inc.
   7  *
   8  * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
   9  */
  10
  11 #include <linux/platform_device.h>
  12
  13 #include <sound/core.h>
  14 #include <sound/pcm.h>
  15 #include <sound/pcm_params.h>
  16
  17 #include <xen/xenbus.h>
  18
  19 #include "xen_snd_front.h"
  20 #include "xen_snd_front_alsa.h"
  21 #include "xen_snd_front_cfg.h"
  22 #include "xen_snd_front_evtchnl.h"
  23 #include "xen_snd_front_shbuf.h"
  24
  25 struct xen_snd_front_pcm_stream_info {
  26         struct xen_snd_front_info *front_info;
  27         struct xen_snd_front_evtchnl_pair *evt_pair;
  28         struct xen_snd_front_shbuf sh_buf;
  29         int index;
  30
  31         bool is_open;
  32         struct snd_pcm_hardware pcm_hw;
  33
  34         /* Number of processed frames as reported by the backend. */
  35         snd_pcm_uframes_t be_cur_frame;
  36         /* Current HW pointer to be reported via .period callback. */
  37         atomic_t hw_ptr;
  38         /* Modulo of the number of processed frames - for period detection. */
  39         u32 out_frames;
  40 };
  41
  42 struct xen_snd_front_pcm_instance_info {
  43         struct xen_snd_front_card_info *card_info;
  44         struct snd_pcm *pcm;
  45         struct snd_pcm_hardware pcm_hw;
  46         int num_pcm_streams_pb;
  47         struct xen_snd_front_pcm_stream_info *streams_pb;
  48         int num_pcm_streams_cap;
  49         struct xen_snd_front_pcm_stream_info *streams_cap;
  50 };
  51
  52 struct xen_snd_front_card_info {
  53         struct xen_snd_front_info *front_info;
  54         struct snd_card *card;
  55         struct snd_pcm_hardware pcm_hw;
  56         int num_pcm_instances;
  57         struct xen_snd_front_pcm_instance_info *pcm_instances;
  58 };
  59
  60 struct alsa_sndif_sample_format {
  61         u8 sndif;
  62         snd_pcm_format_t alsa;
  63 };
  64
  65 struct alsa_sndif_hw_param {
  66         u8 sndif;
  67         snd_pcm_hw_param_t alsa;
  68 };
  69
  70 static const struct alsa_sndif_sample_format ALSA_SNDIF_FORMATS[] = {
  71         {
  72                 .sndif = XENSND_PCM_FORMAT_U8,
  73                 .alsa = SNDRV_PCM_FORMAT_U8
  74         },
  75         {
  76                 .sndif = XENSND_PCM_FORMAT_S8,
  77                 .alsa = SNDRV_PCM_FORMAT_S8
  78         },
  79         {
  80                 .sndif = XENSND_PCM_FORMAT_U16_LE,
  81                 .alsa = SNDRV_PCM_FORMAT_U16_LE
  82         },
  83         {
  84                 .sndif = XENSND_PCM_FORMAT_U16_BE,
  85                 .alsa = SNDRV_PCM_FORMAT_U16_BE
  86         },
  87         {
  88                 .sndif = XENSND_PCM_FORMAT_S16_LE,
  89                 .alsa = SNDRV_PCM_FORMAT_S16_LE
  90         },
  91         {
  92                 .sndif = XENSND_PCM_FORMAT_S16_BE,
  93                 .alsa = SNDRV_PCM_FORMAT_S16_BE
  94         },
  95         {
  96                 .sndif = XENSND_PCM_FORMAT_U24_LE,
  97                 .alsa = SNDRV_PCM_FORMAT_U24_LE
  98         },
  99         {
 100                 .sndif = XENSND_PCM_FORMAT_U24_BE,
 101                 .alsa = SNDRV_PCM_FORMAT_U24_BE
 102         },
 103         {
 104                 .sndif = XENSND_PCM_FORMAT_S24_LE,
 105                 .alsa = SNDRV_PCM_FORMAT_S24_LE
 106         },
 107         {
 108                 .sndif = XENSND_PCM_FORMAT_S24_BE,
 109                 .alsa = SNDRV_PCM_FORMAT_S24_BE
 110         },
 111         {
 112                 .sndif = XENSND_PCM_FORMAT_U32_LE,
 113                 .alsa = SNDRV_PCM_FORMAT_U32_LE
 114         },
 115         {
 116                 .sndif = XENSND_PCM_FORMAT_U32_BE,
 117                 .alsa = SNDRV_PCM_FORMAT_U32_BE
 118         },
 119         {
 120                 .sndif = XENSND_PCM_FORMAT_S32_LE,
 121                 .alsa = SNDRV_PCM_FORMAT_S32_LE
 122         },
 123         {
 124                 .sndif = XENSND_PCM_FORMAT_S32_BE,
 125                 .alsa = SNDRV_PCM_FORMAT_S32_BE
 126         },
 127         {
 128                 .sndif = XENSND_PCM_FORMAT_A_LAW,
 129                 .alsa = SNDRV_PCM_FORMAT_A_LAW
 130         },
 131         {
 132                 .sndif = XENSND_PCM_FORMAT_MU_LAW,
 133                 .alsa = SNDRV_PCM_FORMAT_MU_LAW
 134         },
 135         {
 136                 .sndif = XENSND_PCM_FORMAT_F32_LE,
 137                 .alsa = SNDRV_PCM_FORMAT_FLOAT_LE
 138         },
 139         {
 140                 .sndif = XENSND_PCM_FORMAT_F32_BE,
 141                 .alsa = SNDRV_PCM_FORMAT_FLOAT_BE
 142         },
 143         {
 144                 .sndif = XENSND_PCM_FORMAT_F64_LE,
 145                 .alsa = SNDRV_PCM_FORMAT_FLOAT64_LE
 146         },
 147         {
 148                 .sndif = XENSND_PCM_FORMAT_F64_BE,
 149                 .alsa = SNDRV_PCM_FORMAT_FLOAT64_BE
 150         },
 151         {
 152                 .sndif = XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE,
 153                 .alsa = SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE
 154         },
 155         {
 156                 .sndif = XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE,
 157                 .alsa = SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE
 158         },
 159         {
 160                 .sndif = XENSND_PCM_FORMAT_IMA_ADPCM,
 161                 .alsa = SNDRV_PCM_FORMAT_IMA_ADPCM
 162         },
 163         {
 164                 .sndif = XENSND_PCM_FORMAT_MPEG,
 165                 .alsa = SNDRV_PCM_FORMAT_MPEG
 166         },
 167         {
 168                 .sndif = XENSND_PCM_FORMAT_GSM,
 169                 .alsa = SNDRV_PCM_FORMAT_GSM
 170         },
 171 };
 172
 173 static int to_sndif_format(snd_pcm_format_t format)
 174 {
 175         int i;
 176
 177         for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
 178                 if (ALSA_SNDIF_FORMATS[i].alsa == format)
 179                         return ALSA_SNDIF_FORMATS[i].sndif;
 180
 181         return -EINVAL;
 182 }
 183
 184 static u64 to_sndif_formats_mask(u64 alsa_formats)
 185 {
 186         u64 mask;
 187         int i;
 188
 189         mask = 0;
 190         for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
 191                 if (pcm_format_to_bits(ALSA_SNDIF_FORMATS[i].alsa) & alsa_formats)
 192                         mask |= 1 << ALSA_SNDIF_FORMATS[i].sndif;
 193
 194         return mask;
 195 }
 196
 197 static u64 to_alsa_formats_mask(u64 sndif_formats)
 198 {
 199         u64 mask;
 200         int i;
 201
 202         mask = 0;
 203         for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
 204                 if (1 << ALSA_SNDIF_FORMATS[i].sndif & sndif_formats)
 205                         mask |= pcm_format_to_bits(ALSA_SNDIF_FORMATS[i].alsa);
 206
 207         return mask;
 208 }
 209
 210 static void stream_clear(struct xen_snd_front_pcm_stream_info *stream)
 211 {
 212         stream->is_open = false;
 213         stream->be_cur_frame = 0;
 214         stream->out_frames = 0;
 215         atomic_set(&stream->hw_ptr, 0);
 216         xen_snd_front_evtchnl_pair_clear(stream->evt_pair);
 217         xen_snd_front_shbuf_clear(&stream->sh_buf);
 218 }
 219
 220 static void stream_free(struct xen_snd_front_pcm_stream_info *stream)
 221 {
 222         xen_snd_front_shbuf_free(&stream->sh_buf);
 223         stream_clear(stream);
 224 }
 225
 226 static struct xen_snd_front_pcm_stream_info *
 227 stream_get(struct snd_pcm_substream *substream)
 228 {
 229         struct xen_snd_front_pcm_instance_info *pcm_instance =
 230                         snd_pcm_substream_chip(substream);
 231         struct xen_snd_front_pcm_stream_info *stream;
 232
 233         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 234                 stream = &pcm_instance->streams_pb[substream->number];
 235         else
 236                 stream = &pcm_instance->streams_cap[substream->number];
 237
 238         return stream;
 239 }
 240
 241 static int alsa_hw_rule(struct snd_pcm_hw_params *params,
 242                         struct snd_pcm_hw_rule *rule)
 243 {
 244         struct xen_snd_front_pcm_stream_info *stream = rule->private;
 245         struct device *dev = &stream->front_info->xb_dev->dev;
 246         struct snd_mask *formats =
 247                         hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
 248         struct snd_interval *rates =
 249                         hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
 250         struct snd_interval *channels =
 251                         hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
 252         struct snd_interval *period =
 253                         hw_param_interval(params,
 254                                           SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
 255         struct snd_interval *buffer =
 256                         hw_param_interval(params,
 257                                           SNDRV_PCM_HW_PARAM_BUFFER_SIZE);
 258         struct xensnd_query_hw_param req;
 259         struct xensnd_query_hw_param resp;
 260         struct snd_interval interval;
 261         struct snd_mask mask;
 262         u64 sndif_formats;
 263         int changed, ret;
 264
 265         /* Collect all the values we need for the query. */
 266
 267         req.formats = to_sndif_formats_mask((u64)formats->bits[0] |
 268                                             (u64)(formats->bits[1]) << 32);
 269
 270         req.rates.min = rates->min;
 271         req.rates.max = rates->max;
 272
 273         req.channels.min = channels->min;
 274         req.channels.max = channels->max;
 275
 276         req.buffer.min = buffer->min;
 277         req.buffer.max = buffer->max;
 278
 279         req.period.min = period->min;
 280         req.period.max = period->max;
 281
 282         ret = xen_snd_front_stream_query_hw_param(&stream->evt_pair->req,
 283                                                   &req, &resp);
 284         if (ret < 0) {
 285                 /* Check if this is due to backend communication error. */
 286                 if (ret == -EIO || ret == -ETIMEDOUT)
 287                         dev_err(dev, "Failed to query ALSA HW parameters\n");
 288                 return ret;
 289         }
 290
 291         /* Refine HW parameters after the query. */
 292         changed  = 0;
 293
 294         sndif_formats = to_alsa_formats_mask(resp.formats);
 295         snd_mask_none(&mask);
 296         mask.bits[0] = (u32)sndif_formats;
 297         mask.bits[1] = (u32)(sndif_formats >> 32);
 298         ret = snd_mask_refine(formats, &mask);
 299         if (ret < 0)
 300                 return ret;
 301         changed |= ret;
 302
 303         interval.openmin = 0;
 304         interval.openmax = 0;
 305         interval.integer = 1;
 306
 307         interval.min = resp.rates.min;
 308         interval.max = resp.rates.max;
 309         ret = snd_interval_refine(rates, &interval);
 310         if (ret < 0)
 311                 return ret;
 312         changed |= ret;
 313
 314         interval.min = resp.channels.min;
 315         interval.max = resp.channels.max;
 316         ret = snd_interval_refine(channels, &interval);
 317         if (ret < 0)
 318                 return ret;
 319         changed |= ret;
 320
 321         interval.min = resp.buffer.min;
 322         interval.max = resp.buffer.max;
 323         ret = snd_interval_refine(buffer, &interval);
 324         if (ret < 0)
 325                 return ret;
 326         changed |= ret;
 327
 328         interval.min = resp.period.min;
 329         interval.max = resp.period.max;
 330         ret = snd_interval_refine(period, &interval);
 331         if (ret < 0)
 332                 return ret;
 333         changed |= ret;
 334
 335         return changed;
 336 }
 337
 338 static int alsa_open(struct snd_pcm_substream *substream)
 339 {
 340         struct xen_snd_front_pcm_instance_info *pcm_instance =
 341                         snd_pcm_substream_chip(substream);
 342         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 343         struct snd_pcm_runtime *runtime = substream->runtime;
 344         struct xen_snd_front_info *front_info =
 345                         pcm_instance->card_info->front_info;
 346         struct device *dev = &front_info->xb_dev->dev;
 347         int ret;
 348
 349         /*
 350          * Return our HW properties: override defaults with those configured
 351          * via XenStore.
 352          */
 353         runtime->hw = stream->pcm_hw;
 354         runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
 355                               SNDRV_PCM_INFO_MMAP_VALID |
 356                               SNDRV_PCM_INFO_DOUBLE |
 357                               SNDRV_PCM_INFO_BATCH |
 358                               SNDRV_PCM_INFO_NONINTERLEAVED |
 359                               SNDRV_PCM_INFO_RESUME |
 360                               SNDRV_PCM_INFO_PAUSE);
 361         runtime->hw.info |= SNDRV_PCM_INFO_INTERLEAVED;
 362
 363         stream->evt_pair = &front_info->evt_pairs[stream->index];
 364
 365         stream->front_info = front_info;
 366
 367         stream->evt_pair->evt.u.evt.substream = substream;
 368
 369         stream_clear(stream);
 370
 371         xen_snd_front_evtchnl_pair_set_connected(stream->evt_pair, true);
 372
 373         ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
 374                                   alsa_hw_rule, stream,
 375                                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
 376         if (ret) {
 377                 dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_FORMAT\n");
 378                 return ret;
 379         }
 380
 381         ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
 382                                   alsa_hw_rule, stream,
 383                                   SNDRV_PCM_HW_PARAM_RATE, -1);
 384         if (ret) {
 385                 dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_RATE\n");
 386                 return ret;
 387         }
 388
 389         ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
 390                                   alsa_hw_rule, stream,
 391                                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 392         if (ret) {
 393                 dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_CHANNELS\n");
 394                 return ret;
 395         }
 396
 397         ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
 398                                   alsa_hw_rule, stream,
 399                                   SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
 400         if (ret) {
 401                 dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_PERIOD_SIZE\n");
 402                 return ret;
 403         }
 404
 405         ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
 406                                   alsa_hw_rule, stream,
 407                                   SNDRV_PCM_HW_PARAM_BUFFER_SIZE, -1);
 408         if (ret) {
 409                 dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_BUFFER_SIZE\n");
 410                 return ret;
 411         }
 412
 413         return 0;
 414 }
 415
 416 static int alsa_close(struct snd_pcm_substream *substream)
 417 {
 418         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 419
 420         xen_snd_front_evtchnl_pair_set_connected(stream->evt_pair, false);
 421         return 0;
 422 }
 423
 424 static int alsa_hw_params(struct snd_pcm_substream *substream,
 425                           struct snd_pcm_hw_params *params)
 426 {
 427         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 428         int ret;
 429
 430         /*
 431          * This callback may be called multiple times,
 432          * so free the previously allocated shared buffer if any.
 433          */
 434         stream_free(stream);
 435
 436         ret = xen_snd_front_shbuf_alloc(stream->front_info->xb_dev,
 437                                         &stream->sh_buf,
 438                                         params_buffer_bytes(params));
 439         if (ret < 0) {
 440                 stream_free(stream);
 441                 dev_err(&stream->front_info->xb_dev->dev,
 442                         "Failed to allocate buffers for stream with index %d\n",
 443                         stream->index);
 444                 return ret;
 445         }
 446
 447         return 0;
 448 }
 449
 450 static int alsa_hw_free(struct snd_pcm_substream *substream)
 451 {
 452         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 453         int ret;
 454
 455         ret = xen_snd_front_stream_close(&stream->evt_pair->req);
 456         stream_free(stream);
 457         return ret;
 458 }
 459
 460 static int alsa_prepare(struct snd_pcm_substream *substream)
 461 {
 462         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 463
 464         if (!stream->is_open) {
 465                 struct snd_pcm_runtime *runtime = substream->runtime;
 466                 u8 sndif_format;
 467                 int ret;
 468
 469                 ret = to_sndif_format(runtime->format);
 470                 if (ret < 0) {
 471                         dev_err(&stream->front_info->xb_dev->dev,
 472                                 "Unsupported sample format: %d\n",
 473                                 runtime->format);
 474                         return ret;
 475                 }
 476                 sndif_format = ret;
 477
 478                 ret = xen_snd_front_stream_prepare(&stream->evt_pair->req,
 479                                                    &stream->sh_buf,
 480                                                    sndif_format,
 481                                                    runtime->channels,
 482                                                    runtime->rate,
 483                                                    snd_pcm_lib_buffer_bytes(substream),
 484                                                    snd_pcm_lib_period_bytes(substream));
 485                 if (ret < 0)
 486                         return ret;
 487
 488                 stream->is_open = true;
 489         }
 490
 491         return 0;
 492 }
 493
 494 static int alsa_trigger(struct snd_pcm_substream *substream, int cmd)
 495 {
 496         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 497         int type;
 498
 499         switch (cmd) {
 500         case SNDRV_PCM_TRIGGER_START:
 501                 type = XENSND_OP_TRIGGER_START;
 502                 break;
 503
 504         case SNDRV_PCM_TRIGGER_RESUME:
 505                 type = XENSND_OP_TRIGGER_RESUME;
 506                 break;
 507
 508         case SNDRV_PCM_TRIGGER_STOP:
 509                 type = XENSND_OP_TRIGGER_STOP;
 510                 break;
 511
 512         case SNDRV_PCM_TRIGGER_SUSPEND:
 513                 type = XENSND_OP_TRIGGER_PAUSE;
 514                 break;
 515
 516         default:
 517                 return -EINVAL;
 518         }
 519
 520         return xen_snd_front_stream_trigger(&stream->evt_pair->req, type);
 521 }
 522
 523 void xen_snd_front_alsa_handle_cur_pos(struct xen_snd_front_evtchnl *evtchnl,
 524                                        u64 pos_bytes)
 525 {
 526         struct snd_pcm_substream *substream = evtchnl->u.evt.substream;
 527         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 528         snd_pcm_uframes_t delta, new_hw_ptr, cur_frame;
 529
 530         cur_frame = bytes_to_frames(substream->runtime, pos_bytes);
 531
 532         delta = cur_frame - stream->be_cur_frame;
 533         stream->be_cur_frame = cur_frame;
 534
 535         new_hw_ptr = (snd_pcm_uframes_t)atomic_read(&stream->hw_ptr);
 536         new_hw_ptr = (new_hw_ptr + delta) % substream->runtime->buffer_size;
 537         atomic_set(&stream->hw_ptr, (int)new_hw_ptr);
 538
 539         stream->out_frames += delta;
 540         if (stream->out_frames > substream->runtime->period_size) {
 541                 stream->out_frames %= substream->runtime->period_size;
 542                 snd_pcm_period_elapsed(substream);
 543         }
 544 }
 545
 546 static snd_pcm_uframes_t alsa_pointer(struct snd_pcm_substream *substream)
 547 {
 548         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 549
 550         return (snd_pcm_uframes_t)atomic_read(&stream->hw_ptr);
 551 }
 552
 553 static int alsa_pb_copy_user(struct snd_pcm_substream *substream,
 554                              int channel, unsigned long pos, void __user *src,
 555                              unsigned long count)
 556 {
 557         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 558
 559         if (unlikely(pos + count > stream->sh_buf.buffer_sz))
 560                 return -EINVAL;
 561
 562         if (copy_from_user(stream->sh_buf.buffer + pos, src, count))
 563                 return -EFAULT;
 564
 565         return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
 566 }
 567
 568 static int alsa_pb_copy_kernel(struct snd_pcm_substream *substream,
 569                                int channel, unsigned long pos, void *src,
 570                                unsigned long count)
 571 {
 572         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 573
 574         if (unlikely(pos + count > stream->sh_buf.buffer_sz))
 575                 return -EINVAL;
 576
 577         memcpy(stream->sh_buf.buffer + pos, src, count);
 578
 579         return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
 580 }
 581
 582 static int alsa_cap_copy_user(struct snd_pcm_substream *substream,
 583                               int channel, unsigned long pos, void __user *dst,
 584                               unsigned long count)
 585 {
 586         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 587         int ret;
 588
 589         if (unlikely(pos + count > stream->sh_buf.buffer_sz))
 590                 return -EINVAL;
 591
 592         ret = xen_snd_front_stream_read(&stream->evt_pair->req, pos, count);
 593         if (ret < 0)
 594                 return ret;
 595
 596         return copy_to_user(dst, stream->sh_buf.buffer + pos, count) ?
 597                 -EFAULT : 0;
 598 }
 599
 600 static int alsa_cap_copy_kernel(struct snd_pcm_substream *substream,
 601                                 int channel, unsigned long pos, void *dst,
 602                                 unsigned long count)
 603 {
 604         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 605         int ret;
 606
 607         if (unlikely(pos + count > stream->sh_buf.buffer_sz))
 608                 return -EINVAL;
 609
 610         ret = xen_snd_front_stream_read(&stream->evt_pair->req, pos, count);
 611         if (ret < 0)
 612                 return ret;
 613
 614         memcpy(dst, stream->sh_buf.buffer + pos, count);
 615
 616         return 0;
 617 }
 618
 619 static int alsa_pb_fill_silence(struct snd_pcm_substream *substream,
 620                                 int channel, unsigned long pos,
 621                                 unsigned long count)
 622 {
 623         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 624
 625         if (unlikely(pos + count > stream->sh_buf.buffer_sz))
 626                 return -EINVAL;
 627
 628         memset(stream->sh_buf.buffer + pos, 0, count);
 629
 630         return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
 631 }
 632
 633 /*
 634  * FIXME: The mmaped data transfer is asynchronous and there is no
 635  * ack signal from user-space when it is done. This is the
 636  * reason it is not implemented in the PV driver as we do need
 637  * to know when the buffer can be transferred to the backend.
 638  */
 639
 640 static struct snd_pcm_ops snd_drv_alsa_playback_ops = {
 641         .open = alsa_open,
 642         .close = alsa_close,
 643         .ioctl = snd_pcm_lib_ioctl,
 644         .hw_params = alsa_hw_params,
 645         .hw_free = alsa_hw_free,
 646         .prepare = alsa_prepare,
 647         .trigger = alsa_trigger,
 648         .pointer = alsa_pointer,
 649         .copy_user = alsa_pb_copy_user,
 650         .copy_kernel = alsa_pb_copy_kernel,
 651         .fill_silence = alsa_pb_fill_silence,
 652 };
 653
 654 static struct snd_pcm_ops snd_drv_alsa_capture_ops = {
 655         .open = alsa_open,
 656         .close = alsa_close,
 657         .ioctl = snd_pcm_lib_ioctl,
 658         .hw_params = alsa_hw_params,
 659         .hw_free = alsa_hw_free,
 660         .prepare = alsa_prepare,
 661         .trigger = alsa_trigger,
 662         .pointer = alsa_pointer,
 663         .copy_user = alsa_cap_copy_user,
 664         .copy_kernel = alsa_cap_copy_kernel,
 665 };
 666
 667 static int new_pcm_instance(struct xen_snd_front_card_info *card_info,
 668                             struct xen_front_cfg_pcm_instance *instance_cfg,
 669                             struct xen_snd_front_pcm_instance_info *pcm_instance_info)
 670 {
 671         struct snd_pcm *pcm;
 672         int ret, i;
 673
 674         dev_dbg(&card_info->front_info->xb_dev->dev,
 675                 "New PCM device \"%s\" with id %d playback %d capture %d",
 676                 instance_cfg->name,
 677                 instance_cfg->device_id,
 678                 instance_cfg->num_streams_pb,
 679                 instance_cfg->num_streams_cap);
 680
 681         pcm_instance_info->card_info = card_info;
 682
 683         pcm_instance_info->pcm_hw = instance_cfg->pcm_hw;
 684
 685         if (instance_cfg->num_streams_pb) {
 686                 pcm_instance_info->streams_pb =
 687                                 devm_kcalloc(&card_info->card->card_dev,
 688                                              instance_cfg->num_streams_pb,
 689                                              sizeof(struct xen_snd_front_pcm_stream_info),
 690                                              GFP_KERNEL);
 691                 if (!pcm_instance_info->streams_pb)
 692                         return -ENOMEM;
 693         }
 694
 695         if (instance_cfg->num_streams_cap) {
 696                 pcm_instance_info->streams_cap =
 697                                 devm_kcalloc(&card_info->card->card_dev,
 698                                              instance_cfg->num_streams_cap,
 699                                              sizeof(struct xen_snd_front_pcm_stream_info),
 700                                              GFP_KERNEL);
 701                 if (!pcm_instance_info->streams_cap)
 702                         return -ENOMEM;
 703         }
 704
 705         pcm_instance_info->num_pcm_streams_pb =
 706                         instance_cfg->num_streams_pb;
 707         pcm_instance_info->num_pcm_streams_cap =
 708                         instance_cfg->num_streams_cap;
 709
 710         for (i = 0; i < pcm_instance_info->num_pcm_streams_pb; i++) {
 711                 pcm_instance_info->streams_pb[i].pcm_hw =
 712                         instance_cfg->streams_pb[i].pcm_hw;
 713                 pcm_instance_info->streams_pb[i].index =
 714                         instance_cfg->streams_pb[i].index;
 715         }
 716
 717         for (i = 0; i < pcm_instance_info->num_pcm_streams_cap; i++) {
 718                 pcm_instance_info->streams_cap[i].pcm_hw =
 719                         instance_cfg->streams_cap[i].pcm_hw;
 720                 pcm_instance_info->streams_cap[i].index =
 721                         instance_cfg->streams_cap[i].index;
 722         }
 723
 724         ret = snd_pcm_new(card_info->card, instance_cfg->name,
 725                           instance_cfg->device_id,
 726                           instance_cfg->num_streams_pb,
 727                           instance_cfg->num_streams_cap,
 728                           &pcm);
 729         if (ret < 0)
 730                 return ret;
 731
 732         pcm->private_data = pcm_instance_info;
 733         pcm->info_flags = 0;
 734         /* we want to handle all PCM operations in non-atomic context */
 735         pcm->nonatomic = true;
 736         strncpy(pcm->name, "Virtual card PCM", sizeof(pcm->name));
 737
 738         if (instance_cfg->num_streams_pb)
 739                 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 740                                 &snd_drv_alsa_playback_ops);
 741
 742         if (instance_cfg->num_streams_cap)
 743                 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
 744                                 &snd_drv_alsa_capture_ops);
 745
 746         pcm_instance_info->pcm = pcm;
 747         return 0;
 748 }
 749
 750 int xen_snd_front_alsa_init(struct xen_snd_front_info *front_info)
 751 {
 752         struct device *dev = &front_info->xb_dev->dev;
 753         struct xen_front_cfg_card *cfg = &front_info->cfg;
 754         struct xen_snd_front_card_info *card_info;
 755         struct snd_card *card;
 756         int ret, i;
 757
 758         dev_dbg(dev, "Creating virtual sound card\n");
 759
 760         ret = snd_card_new(dev, 0, XENSND_DRIVER_NAME, THIS_MODULE,
 761                            sizeof(struct xen_snd_front_card_info), &card);
 762         if (ret < 0)
 763                 return ret;
 764
 765         card_info = card->private_data;
 766         card_info->front_info = front_info;
 767         front_info->card_info = card_info;
 768         card_info->card = card;
 769         card_info->pcm_instances =
 770                         devm_kcalloc(dev, cfg->num_pcm_instances,
 771                                      sizeof(struct xen_snd_front_pcm_instance_info),
 772                                      GFP_KERNEL);
 773         if (!card_info->pcm_instances) {
 774                 ret = -ENOMEM;
 775                 goto fail;
 776         }
 777
 778         card_info->num_pcm_instances = cfg->num_pcm_instances;
 779         card_info->pcm_hw = cfg->pcm_hw;
 780
 781         for (i = 0; i < cfg->num_pcm_instances; i++) {
 782                 ret = new_pcm_instance(card_info, &cfg->pcm_instances[i],
 783                                        &card_info->pcm_instances[i]);
 784                 if (ret < 0)
 785                         goto fail;
 786         }
 787
 788         strncpy(card->driver, XENSND_DRIVER_NAME, sizeof(card->driver));
 789         strncpy(card->shortname, cfg->name_short, sizeof(card->shortname));
 790         strncpy(card->longname, cfg->name_long, sizeof(card->longname));
 791
 792         ret = snd_card_register(card);
 793         if (ret < 0)
 794                 goto fail;
 795
 796         return 0;
 797
 798 fail:
 799         snd_card_free(card);
 800         return ret;
 801 }
 802
 803 void xen_snd_front_alsa_fini(struct xen_snd_front_info *front_info)
 804 {
 805         struct xen_snd_front_card_info *card_info;
 806         struct snd_card *card;
 807
 808         card_info = front_info->card_info;
 809         if (!card_info)
 810                 return;
 811
 812         card = card_info->card;
 813         if (!card)
 814                 return;
 815
 816         dev_dbg(&front_info->xb_dev->dev, "Removing virtual sound card %d\n",
 817                 card->number);
 818         snd_card_free(card);
 819
 820         /* Card_info will be freed when destroying front_info->xb_dev->dev. */
 821         card_info->card = NULL;
 822 }