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 #include <xen/xen-front-pgdir-shbuf.h>
  19
  20 #include "xen_snd_front.h"
  21 #include "xen_snd_front_alsa.h"
  22 #include "xen_snd_front_cfg.h"
  23 #include "xen_snd_front_evtchnl.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
  29         /* This is the shared buffer with its backing storage. */
  30         struct xen_front_pgdir_shbuf shbuf;
  31         u8 *buffer;
  32         size_t buffer_sz;
  33         int num_pages;
  34         struct page **pages;
  35
  36         int index;
  37
  38         bool is_open;
  39         struct snd_pcm_hardware pcm_hw;
  40
  41         /* Number of processed frames as reported by the backend. */
  42         snd_pcm_uframes_t be_cur_frame;
  43         /* Current HW pointer to be reported via .period callback. */
  44         atomic_t hw_ptr;
  45         /* Modulo of the number of processed frames - for period detection. */
  46         u32 out_frames;
  47 };
  48
  49 struct xen_snd_front_pcm_instance_info {
  50         struct xen_snd_front_card_info *card_info;
  51         struct snd_pcm *pcm;
  52         struct snd_pcm_hardware pcm_hw;
  53         int num_pcm_streams_pb;
  54         struct xen_snd_front_pcm_stream_info *streams_pb;
  55         int num_pcm_streams_cap;
  56         struct xen_snd_front_pcm_stream_info *streams_cap;
  57 };
  58
  59 struct xen_snd_front_card_info {
  60         struct xen_snd_front_info *front_info;
  61         struct snd_card *card;
  62         struct snd_pcm_hardware pcm_hw;
  63         int num_pcm_instances;
  64         struct xen_snd_front_pcm_instance_info *pcm_instances;
  65 };
  66
  67 struct alsa_sndif_sample_format {
  68         u8 sndif;
  69         snd_pcm_format_t alsa;
  70 };
  71
  72 struct alsa_sndif_hw_param {
  73         u8 sndif;
  74         snd_pcm_hw_param_t alsa;
  75 };
  76
  77 static const struct alsa_sndif_sample_format ALSA_SNDIF_FORMATS[] = {
  78         {
  79                 .sndif = XENSND_PCM_FORMAT_U8,
  80                 .alsa = SNDRV_PCM_FORMAT_U8
  81         },
  82         {
  83                 .sndif = XENSND_PCM_FORMAT_S8,
  84                 .alsa = SNDRV_PCM_FORMAT_S8
  85         },
  86         {
  87                 .sndif = XENSND_PCM_FORMAT_U16_LE,
  88                 .alsa = SNDRV_PCM_FORMAT_U16_LE
  89         },
  90         {
  91                 .sndif = XENSND_PCM_FORMAT_U16_BE,
  92                 .alsa = SNDRV_PCM_FORMAT_U16_BE
  93         },
  94         {
  95                 .sndif = XENSND_PCM_FORMAT_S16_LE,
  96                 .alsa = SNDRV_PCM_FORMAT_S16_LE
  97         },
  98         {
  99                 .sndif = XENSND_PCM_FORMAT_S16_BE,
 100                 .alsa = SNDRV_PCM_FORMAT_S16_BE
 101         },
 102         {
 103                 .sndif = XENSND_PCM_FORMAT_U24_LE,
 104                 .alsa = SNDRV_PCM_FORMAT_U24_LE
 105         },
 106         {
 107                 .sndif = XENSND_PCM_FORMAT_U24_BE,
 108                 .alsa = SNDRV_PCM_FORMAT_U24_BE
 109         },
 110         {
 111                 .sndif = XENSND_PCM_FORMAT_S24_LE,
 112                 .alsa = SNDRV_PCM_FORMAT_S24_LE
 113         },
 114         {
 115                 .sndif = XENSND_PCM_FORMAT_S24_BE,
 116                 .alsa = SNDRV_PCM_FORMAT_S24_BE
 117         },
 118         {
 119                 .sndif = XENSND_PCM_FORMAT_U32_LE,
 120                 .alsa = SNDRV_PCM_FORMAT_U32_LE
 121         },
 122         {
 123                 .sndif = XENSND_PCM_FORMAT_U32_BE,
 124                 .alsa = SNDRV_PCM_FORMAT_U32_BE
 125         },
 126         {
 127                 .sndif = XENSND_PCM_FORMAT_S32_LE,
 128                 .alsa = SNDRV_PCM_FORMAT_S32_LE
 129         },
 130         {
 131                 .sndif = XENSND_PCM_FORMAT_S32_BE,
 132                 .alsa = SNDRV_PCM_FORMAT_S32_BE
 133         },
 134         {
 135                 .sndif = XENSND_PCM_FORMAT_A_LAW,
 136                 .alsa = SNDRV_PCM_FORMAT_A_LAW
 137         },
 138         {
 139                 .sndif = XENSND_PCM_FORMAT_MU_LAW,
 140                 .alsa = SNDRV_PCM_FORMAT_MU_LAW
 141         },
 142         {
 143                 .sndif = XENSND_PCM_FORMAT_F32_LE,
 144                 .alsa = SNDRV_PCM_FORMAT_FLOAT_LE
 145         },
 146         {
 147                 .sndif = XENSND_PCM_FORMAT_F32_BE,
 148                 .alsa = SNDRV_PCM_FORMAT_FLOAT_BE
 149         },
 150         {
 151                 .sndif = XENSND_PCM_FORMAT_F64_LE,
 152                 .alsa = SNDRV_PCM_FORMAT_FLOAT64_LE
 153         },
 154         {
 155                 .sndif = XENSND_PCM_FORMAT_F64_BE,
 156                 .alsa = SNDRV_PCM_FORMAT_FLOAT64_BE
 157         },
 158         {
 159                 .sndif = XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE,
 160                 .alsa = SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE
 161         },
 162         {
 163                 .sndif = XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE,
 164                 .alsa = SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE
 165         },
 166         {
 167                 .sndif = XENSND_PCM_FORMAT_IMA_ADPCM,
 168                 .alsa = SNDRV_PCM_FORMAT_IMA_ADPCM
 169         },
 170         {
 171                 .sndif = XENSND_PCM_FORMAT_MPEG,
 172                 .alsa = SNDRV_PCM_FORMAT_MPEG
 173         },
 174         {
 175                 .sndif = XENSND_PCM_FORMAT_GSM,
 176                 .alsa = SNDRV_PCM_FORMAT_GSM
 177         },
 178 };
 179
 180 static int to_sndif_format(snd_pcm_format_t format)
 181 {
 182         int i;
 183
 184         for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
 185                 if (ALSA_SNDIF_FORMATS[i].alsa == format)
 186                         return ALSA_SNDIF_FORMATS[i].sndif;
 187
 188         return -EINVAL;
 189 }
 190
 191 static u64 to_sndif_formats_mask(u64 alsa_formats)
 192 {
 193         u64 mask;
 194         int i;
 195
 196         mask = 0;
 197         for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
 198                 if (pcm_format_to_bits(ALSA_SNDIF_FORMATS[i].alsa) & alsa_formats)
 199                         mask |= 1 << ALSA_SNDIF_FORMATS[i].sndif;
 200
 201         return mask;
 202 }
 203
 204 static u64 to_alsa_formats_mask(u64 sndif_formats)
 205 {
 206         u64 mask;
 207         int i;
 208
 209         mask = 0;
 210         for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
 211                 if (1 << ALSA_SNDIF_FORMATS[i].sndif & sndif_formats)
 212                         mask |= pcm_format_to_bits(ALSA_SNDIF_FORMATS[i].alsa);
 213
 214         return mask;
 215 }
 216
 217 static void stream_clear(struct xen_snd_front_pcm_stream_info *stream)
 218 {
 219         stream->is_open = false;
 220         stream->be_cur_frame = 0;
 221         stream->out_frames = 0;
 222         atomic_set(&stream->hw_ptr, 0);
 223         xen_snd_front_evtchnl_pair_clear(stream->evt_pair);
 224         memset(&stream->shbuf, 0, sizeof(stream->shbuf));
 225         stream->buffer = NULL;
 226         stream->buffer_sz = 0;
 227         stream->pages = NULL;
 228         stream->num_pages = 0;
 229 }
 230
 231 static void stream_free(struct xen_snd_front_pcm_stream_info *stream)
 232 {
 233         xen_front_pgdir_shbuf_unmap(&stream->shbuf);
 234         xen_front_pgdir_shbuf_free(&stream->shbuf);
 235         if (stream->buffer)
 236                 free_pages_exact(stream->buffer, stream->buffer_sz);
 237         kfree(stream->pages);
 238         stream_clear(stream);
 239 }
 240
 241 static struct xen_snd_front_pcm_stream_info *
 242 stream_get(struct snd_pcm_substream *substream)
 243 {
 244         struct xen_snd_front_pcm_instance_info *pcm_instance =
 245                         snd_pcm_substream_chip(substream);
 246         struct xen_snd_front_pcm_stream_info *stream;
 247
 248         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 249                 stream = &pcm_instance->streams_pb[substream->number];
 250         else
 251                 stream = &pcm_instance->streams_cap[substream->number];
 252
 253         return stream;
 254 }
 255
 256 static int alsa_hw_rule(struct snd_pcm_hw_params *params,
 257                         struct snd_pcm_hw_rule *rule)
 258 {
 259         struct xen_snd_front_pcm_stream_info *stream = rule->private;
 260         struct device *dev = &stream->front_info->xb_dev->dev;
 261         struct snd_mask *formats =
 262                         hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
 263         struct snd_interval *rates =
 264                         hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
 265         struct snd_interval *channels =
 266                         hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
 267         struct snd_interval *period =
 268                         hw_param_interval(params,
 269                                           SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
 270         struct snd_interval *buffer =
 271                         hw_param_interval(params,
 272                                           SNDRV_PCM_HW_PARAM_BUFFER_SIZE);
 273         struct xensnd_query_hw_param req;
 274         struct xensnd_query_hw_param resp;
 275         struct snd_interval interval;
 276         struct snd_mask mask;
 277         u64 sndif_formats;
 278         int changed, ret;
 279
 280         /* Collect all the values we need for the query. */
 281
 282         req.formats = to_sndif_formats_mask((u64)formats->bits[0] |
 283                                             (u64)(formats->bits[1]) << 32);
 284
 285         req.rates.min = rates->min;
 286         req.rates.max = rates->max;
 287
 288         req.channels.min = channels->min;
 289         req.channels.max = channels->max;
 290
 291         req.buffer.min = buffer->min;
 292         req.buffer.max = buffer->max;
 293
 294         req.period.min = period->min;
 295         req.period.max = period->max;
 296
 297         ret = xen_snd_front_stream_query_hw_param(&stream->evt_pair->req,
 298                                                   &req, &resp);
 299         if (ret < 0) {
 300                 /* Check if this is due to backend communication error. */
 301                 if (ret == -EIO || ret == -ETIMEDOUT)
 302                         dev_err(dev, "Failed to query ALSA HW parameters\n");
 303                 return ret;
 304         }
 305
 306         /* Refine HW parameters after the query. */
 307         changed  = 0;
 308
 309         sndif_formats = to_alsa_formats_mask(resp.formats);
 310         snd_mask_none(&mask);
 311         mask.bits[0] = (u32)sndif_formats;
 312         mask.bits[1] = (u32)(sndif_formats >> 32);
 313         ret = snd_mask_refine(formats, &mask);
 314         if (ret < 0)
 315                 return ret;
 316         changed |= ret;
 317
 318         interval.openmin = 0;
 319         interval.openmax = 0;
 320         interval.integer = 1;
 321
 322         interval.min = resp.rates.min;
 323         interval.max = resp.rates.max;
 324         ret = snd_interval_refine(rates, &interval);
 325         if (ret < 0)
 326                 return ret;
 327         changed |= ret;
 328
 329         interval.min = resp.channels.min;
 330         interval.max = resp.channels.max;
 331         ret = snd_interval_refine(channels, &interval);
 332         if (ret < 0)
 333                 return ret;
 334         changed |= ret;
 335
 336         interval.min = resp.buffer.min;
 337         interval.max = resp.buffer.max;
 338         ret = snd_interval_refine(buffer, &interval);
 339         if (ret < 0)
 340                 return ret;
 341         changed |= ret;
 342
 343         interval.min = resp.period.min;
 344         interval.max = resp.period.max;
 345         ret = snd_interval_refine(period, &interval);
 346         if (ret < 0)
 347                 return ret;
 348         changed |= ret;
 349
 350         return changed;
 351 }
 352
 353 static int alsa_open(struct snd_pcm_substream *substream)
 354 {
 355         struct xen_snd_front_pcm_instance_info *pcm_instance =
 356                         snd_pcm_substream_chip(substream);
 357         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 358         struct snd_pcm_runtime *runtime = substream->runtime;
 359         struct xen_snd_front_info *front_info =
 360                         pcm_instance->card_info->front_info;
 361         struct device *dev = &front_info->xb_dev->dev;
 362         int ret;
 363
 364         /*
 365          * Return our HW properties: override defaults with those configured
 366          * via XenStore.
 367          */
 368         runtime->hw = stream->pcm_hw;
 369         runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
 370                               SNDRV_PCM_INFO_MMAP_VALID |
 371                               SNDRV_PCM_INFO_DOUBLE |
 372                               SNDRV_PCM_INFO_BATCH |
 373                               SNDRV_PCM_INFO_NONINTERLEAVED |
 374                               SNDRV_PCM_INFO_RESUME |
 375                               SNDRV_PCM_INFO_PAUSE);
 376         runtime->hw.info |= SNDRV_PCM_INFO_INTERLEAVED;
 377
 378         stream->evt_pair = &front_info->evt_pairs[stream->index];
 379
 380         stream->front_info = front_info;
 381
 382         stream->evt_pair->evt.u.evt.substream = substream;
 383
 384         stream_clear(stream);
 385
 386         xen_snd_front_evtchnl_pair_set_connected(stream->evt_pair, true);
 387
 388         ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
 389                                   alsa_hw_rule, stream,
 390                                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
 391         if (ret) {
 392                 dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_FORMAT\n");
 393                 return ret;
 394         }
 395
 396         ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
 397                                   alsa_hw_rule, stream,
 398                                   SNDRV_PCM_HW_PARAM_RATE, -1);
 399         if (ret) {
 400                 dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_RATE\n");
 401                 return ret;
 402         }
 403
 404         ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
 405                                   alsa_hw_rule, stream,
 406                                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 407         if (ret) {
 408                 dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_CHANNELS\n");
 409                 return ret;
 410         }
 411
 412         ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
 413                                   alsa_hw_rule, stream,
 414                                   SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
 415         if (ret) {
 416                 dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_PERIOD_SIZE\n");
 417                 return ret;
 418         }
 419
 420         ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
 421                                   alsa_hw_rule, stream,
 422                                   SNDRV_PCM_HW_PARAM_BUFFER_SIZE, -1);
 423         if (ret) {
 424                 dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_BUFFER_SIZE\n");
 425                 return ret;
 426         }
 427
 428         return 0;
 429 }
 430
 431 static int alsa_close(struct snd_pcm_substream *substream)
 432 {
 433         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 434
 435         xen_snd_front_evtchnl_pair_set_connected(stream->evt_pair, false);
 436         return 0;
 437 }
 438
 439 static int shbuf_setup_backstore(struct xen_snd_front_pcm_stream_info *stream,
 440                                  size_t buffer_sz)
 441 {
 442         int i;
 443
 444         stream->buffer = alloc_pages_exact(buffer_sz, GFP_KERNEL);
 445         if (!stream->buffer)
 446                 return -ENOMEM;
 447
 448         stream->buffer_sz = buffer_sz;
 449         stream->num_pages = DIV_ROUND_UP(stream->buffer_sz, PAGE_SIZE);
 450         stream->pages = kcalloc(stream->num_pages, sizeof(struct page *),
 451                                 GFP_KERNEL);
 452         if (!stream->pages)
 453                 return -ENOMEM;
 454
 455         for (i = 0; i < stream->num_pages; i++)
 456                 stream->pages[i] = virt_to_page(stream->buffer + i * PAGE_SIZE);
 457
 458         return 0;
 459 }
 460
 461 static int alsa_hw_params(struct snd_pcm_substream *substream,
 462                           struct snd_pcm_hw_params *params)
 463 {
 464         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 465         struct xen_snd_front_info *front_info = stream->front_info;
 466         struct xen_front_pgdir_shbuf_cfg buf_cfg;
 467         int ret;
 468
 469         /*
 470          * This callback may be called multiple times,
 471          * so free the previously allocated shared buffer if any.
 472          */
 473         stream_free(stream);
 474         ret = shbuf_setup_backstore(stream, params_buffer_bytes(params));
 475         if (ret < 0)
 476                 goto fail;
 477
 478         memset(&buf_cfg, 0, sizeof(buf_cfg));
 479         buf_cfg.xb_dev = front_info->xb_dev;
 480         buf_cfg.pgdir = &stream->shbuf;
 481         buf_cfg.num_pages = stream->num_pages;
 482         buf_cfg.pages = stream->pages;
 483
 484         ret = xen_front_pgdir_shbuf_alloc(&buf_cfg);
 485         if (ret < 0)
 486                 goto fail;
 487
 488         ret = xen_front_pgdir_shbuf_map(&stream->shbuf);
 489         if (ret < 0)
 490                 goto fail;
 491
 492         return 0;
 493
 494 fail:
 495         stream_free(stream);
 496         dev_err(&front_info->xb_dev->dev,
 497                 "Failed to allocate buffers for stream with index %d\n",
 498                 stream->index);
 499         return ret;
 500 }
 501
 502 static int alsa_hw_free(struct snd_pcm_substream *substream)
 503 {
 504         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 505         int ret;
 506
 507         ret = xen_snd_front_stream_close(&stream->evt_pair->req);
 508         stream_free(stream);
 509         return ret;
 510 }
 511
 512 static int alsa_prepare(struct snd_pcm_substream *substream)
 513 {
 514         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 515
 516         if (!stream->is_open) {
 517                 struct snd_pcm_runtime *runtime = substream->runtime;
 518                 u8 sndif_format;
 519                 int ret;
 520
 521                 ret = to_sndif_format(runtime->format);
 522                 if (ret < 0) {
 523                         dev_err(&stream->front_info->xb_dev->dev,
 524                                 "Unsupported sample format: %d\n",
 525                                 runtime->format);
 526                         return ret;
 527                 }
 528                 sndif_format = ret;
 529
 530                 ret = xen_snd_front_stream_prepare(&stream->evt_pair->req,
 531                                                    &stream->shbuf,
 532                                                    sndif_format,
 533                                                    runtime->channels,
 534                                                    runtime->rate,
 535                                                    snd_pcm_lib_buffer_bytes(substream),
 536                                                    snd_pcm_lib_period_bytes(substream));
 537                 if (ret < 0)
 538                         return ret;
 539
 540                 stream->is_open = true;
 541         }
 542
 543         return 0;
 544 }
 545
 546 static int alsa_trigger(struct snd_pcm_substream *substream, int cmd)
 547 {
 548         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 549         int type;
 550
 551         switch (cmd) {
 552         case SNDRV_PCM_TRIGGER_START:
 553                 type = XENSND_OP_TRIGGER_START;
 554                 break;
 555
 556         case SNDRV_PCM_TRIGGER_RESUME:
 557                 type = XENSND_OP_TRIGGER_RESUME;
 558                 break;
 559
 560         case SNDRV_PCM_TRIGGER_STOP:
 561                 type = XENSND_OP_TRIGGER_STOP;
 562                 break;
 563
 564         case SNDRV_PCM_TRIGGER_SUSPEND:
 565                 type = XENSND_OP_TRIGGER_PAUSE;
 566                 break;
 567
 568         default:
 569                 return -EINVAL;
 570         }
 571
 572         return xen_snd_front_stream_trigger(&stream->evt_pair->req, type);
 573 }
 574
 575 void xen_snd_front_alsa_handle_cur_pos(struct xen_snd_front_evtchnl *evtchnl,
 576                                        u64 pos_bytes)
 577 {
 578         struct snd_pcm_substream *substream = evtchnl->u.evt.substream;
 579         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 580         snd_pcm_uframes_t delta, new_hw_ptr, cur_frame;
 581
 582         cur_frame = bytes_to_frames(substream->runtime, pos_bytes);
 583
 584         delta = cur_frame - stream->be_cur_frame;
 585         stream->be_cur_frame = cur_frame;
 586
 587         new_hw_ptr = (snd_pcm_uframes_t)atomic_read(&stream->hw_ptr);
 588         new_hw_ptr = (new_hw_ptr + delta) % substream->runtime->buffer_size;
 589         atomic_set(&stream->hw_ptr, (int)new_hw_ptr);
 590
 591         stream->out_frames += delta;
 592         if (stream->out_frames > substream->runtime->period_size) {
 593                 stream->out_frames %= substream->runtime->period_size;
 594                 snd_pcm_period_elapsed(substream);
 595         }
 596 }
 597
 598 static snd_pcm_uframes_t alsa_pointer(struct snd_pcm_substream *substream)
 599 {
 600         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 601
 602         return (snd_pcm_uframes_t)atomic_read(&stream->hw_ptr);
 603 }
 604
 605 static int alsa_pb_copy_user(struct snd_pcm_substream *substream,
 606                              int channel, unsigned long pos, void __user *src,
 607                              unsigned long count)
 608 {
 609         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 610
 611         if (unlikely(pos + count > stream->buffer_sz))
 612                 return -EINVAL;
 613
 614         if (copy_from_user(stream->buffer + pos, src, count))
 615                 return -EFAULT;
 616
 617         return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
 618 }
 619
 620 static int alsa_pb_copy_kernel(struct snd_pcm_substream *substream,
 621                                int channel, unsigned long pos, void *src,
 622                                unsigned long count)
 623 {
 624         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 625
 626         if (unlikely(pos + count > stream->buffer_sz))
 627                 return -EINVAL;
 628
 629         memcpy(stream->buffer + pos, src, count);
 630
 631         return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
 632 }
 633
 634 static int alsa_cap_copy_user(struct snd_pcm_substream *substream,
 635                               int channel, unsigned long pos, void __user *dst,
 636                               unsigned long count)
 637 {
 638         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 639         int ret;
 640
 641         if (unlikely(pos + count > stream->buffer_sz))
 642                 return -EINVAL;
 643
 644         ret = xen_snd_front_stream_read(&stream->evt_pair->req, pos, count);
 645         if (ret < 0)
 646                 return ret;
 647
 648         return copy_to_user(dst, stream->buffer + pos, count) ?
 649                 -EFAULT : 0;
 650 }
 651
 652 static int alsa_cap_copy_kernel(struct snd_pcm_substream *substream,
 653                                 int channel, unsigned long pos, void *dst,
 654                                 unsigned long count)
 655 {
 656         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 657         int ret;
 658
 659         if (unlikely(pos + count > stream->buffer_sz))
 660                 return -EINVAL;
 661
 662         ret = xen_snd_front_stream_read(&stream->evt_pair->req, pos, count);
 663         if (ret < 0)
 664                 return ret;
 665
 666         memcpy(dst, stream->buffer + pos, count);
 667
 668         return 0;
 669 }
 670
 671 static int alsa_pb_fill_silence(struct snd_pcm_substream *substream,
 672                                 int channel, unsigned long pos,
 673                                 unsigned long count)
 674 {
 675         struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
 676
 677         if (unlikely(pos + count > stream->buffer_sz))
 678                 return -EINVAL;
 679
 680         memset(stream->buffer + pos, 0, count);
 681
 682         return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
 683 }
 684
 685 /*
 686  * FIXME: The mmaped data transfer is asynchronous and there is no
 687  * ack signal from user-space when it is done. This is the
 688  * reason it is not implemented in the PV driver as we do need
 689  * to know when the buffer can be transferred to the backend.
 690  */
 691
 692 static const struct snd_pcm_ops snd_drv_alsa_playback_ops = {
 693         .open           = alsa_open,
 694         .close          = alsa_close,
 695         .ioctl          = snd_pcm_lib_ioctl,
 696         .hw_params      = alsa_hw_params,
 697         .hw_free        = alsa_hw_free,
 698         .prepare        = alsa_prepare,
 699         .trigger        = alsa_trigger,
 700         .pointer        = alsa_pointer,
 701         .copy_user      = alsa_pb_copy_user,
 702         .copy_kernel    = alsa_pb_copy_kernel,
 703         .fill_silence   = alsa_pb_fill_silence,
 704 };
 705
 706 static const struct snd_pcm_ops snd_drv_alsa_capture_ops = {
 707         .open           = alsa_open,
 708         .close          = alsa_close,
 709         .ioctl          = snd_pcm_lib_ioctl,
 710         .hw_params      = alsa_hw_params,
 711         .hw_free        = alsa_hw_free,
 712         .prepare        = alsa_prepare,
 713         .trigger        = alsa_trigger,
 714         .pointer        = alsa_pointer,
 715         .copy_user      = alsa_cap_copy_user,
 716         .copy_kernel    = alsa_cap_copy_kernel,
 717 };
 718
 719 static int new_pcm_instance(struct xen_snd_front_card_info *card_info,
 720                             struct xen_front_cfg_pcm_instance *instance_cfg,
 721                             struct xen_snd_front_pcm_instance_info *pcm_instance_info)
 722 {
 723         struct snd_pcm *pcm;
 724         int ret, i;
 725
 726         dev_dbg(&card_info->front_info->xb_dev->dev,
 727                 "New PCM device \"%s\" with id %d playback %d capture %d",
 728                 instance_cfg->name,
 729                 instance_cfg->device_id,
 730                 instance_cfg->num_streams_pb,
 731                 instance_cfg->num_streams_cap);
 732
 733         pcm_instance_info->card_info = card_info;
 734
 735         pcm_instance_info->pcm_hw = instance_cfg->pcm_hw;
 736
 737         if (instance_cfg->num_streams_pb) {
 738                 pcm_instance_info->streams_pb =
 739                                 devm_kcalloc(&card_info->card->card_dev,
 740                                              instance_cfg->num_streams_pb,
 741                                              sizeof(struct xen_snd_front_pcm_stream_info),
 742                                              GFP_KERNEL);
 743                 if (!pcm_instance_info->streams_pb)
 744                         return -ENOMEM;
 745         }
 746
 747         if (instance_cfg->num_streams_cap) {
 748                 pcm_instance_info->streams_cap =
 749                                 devm_kcalloc(&card_info->card->card_dev,
 750                                              instance_cfg->num_streams_cap,
 751                                              sizeof(struct xen_snd_front_pcm_stream_info),
 752                                              GFP_KERNEL);
 753                 if (!pcm_instance_info->streams_cap)
 754                         return -ENOMEM;
 755         }
 756
 757         pcm_instance_info->num_pcm_streams_pb =
 758                         instance_cfg->num_streams_pb;
 759         pcm_instance_info->num_pcm_streams_cap =
 760                         instance_cfg->num_streams_cap;
 761
 762         for (i = 0; i < pcm_instance_info->num_pcm_streams_pb; i++) {
 763                 pcm_instance_info->streams_pb[i].pcm_hw =
 764                         instance_cfg->streams_pb[i].pcm_hw;
 765                 pcm_instance_info->streams_pb[i].index =
 766                         instance_cfg->streams_pb[i].index;
 767         }
 768
 769         for (i = 0; i < pcm_instance_info->num_pcm_streams_cap; i++) {
 770                 pcm_instance_info->streams_cap[i].pcm_hw =
 771                         instance_cfg->streams_cap[i].pcm_hw;
 772                 pcm_instance_info->streams_cap[i].index =
 773                         instance_cfg->streams_cap[i].index;
 774         }
 775
 776         ret = snd_pcm_new(card_info->card, instance_cfg->name,
 777                           instance_cfg->device_id,
 778                           instance_cfg->num_streams_pb,
 779                           instance_cfg->num_streams_cap,
 780                           &pcm);
 781         if (ret < 0)
 782                 return ret;
 783
 784         pcm->private_data = pcm_instance_info;
 785         pcm->info_flags = 0;
 786         /* we want to handle all PCM operations in non-atomic context */
 787         pcm->nonatomic = true;
 788         strncpy(pcm->name, "Virtual card PCM", sizeof(pcm->name));
 789
 790         if (instance_cfg->num_streams_pb)
 791                 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 792                                 &snd_drv_alsa_playback_ops);
 793
 794         if (instance_cfg->num_streams_cap)
 795                 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
 796                                 &snd_drv_alsa_capture_ops);
 797
 798         pcm_instance_info->pcm = pcm;
 799         return 0;
 800 }
 801
 802 int xen_snd_front_alsa_init(struct xen_snd_front_info *front_info)
 803 {
 804         struct device *dev = &front_info->xb_dev->dev;
 805         struct xen_front_cfg_card *cfg = &front_info->cfg;
 806         struct xen_snd_front_card_info *card_info;
 807         struct snd_card *card;
 808         int ret, i;
 809
 810         dev_dbg(dev, "Creating virtual sound card\n");
 811
 812         ret = snd_card_new(dev, 0, XENSND_DRIVER_NAME, THIS_MODULE,
 813                            sizeof(struct xen_snd_front_card_info), &card);
 814         if (ret < 0)
 815                 return ret;
 816
 817         card_info = card->private_data;
 818         card_info->front_info = front_info;
 819         front_info->card_info = card_info;
 820         card_info->card = card;
 821         card_info->pcm_instances =
 822                         devm_kcalloc(dev, cfg->num_pcm_instances,
 823                                      sizeof(struct xen_snd_front_pcm_instance_info),
 824                                      GFP_KERNEL);
 825         if (!card_info->pcm_instances) {
 826                 ret = -ENOMEM;
 827                 goto fail;
 828         }
 829
 830         card_info->num_pcm_instances = cfg->num_pcm_instances;
 831         card_info->pcm_hw = cfg->pcm_hw;
 832
 833         for (i = 0; i < cfg->num_pcm_instances; i++) {
 834                 ret = new_pcm_instance(card_info, &cfg->pcm_instances[i],
 835                                        &card_info->pcm_instances[i]);
 836                 if (ret < 0)
 837                         goto fail;
 838         }
 839
 840         strncpy(card->driver, XENSND_DRIVER_NAME, sizeof(card->driver));
 841         strncpy(card->shortname, cfg->name_short, sizeof(card->shortname));
 842         strncpy(card->longname, cfg->name_long, sizeof(card->longname));
 843
 844         ret = snd_card_register(card);
 845         if (ret < 0)
 846                 goto fail;
 847
 848         return 0;
 849
 850 fail:
 851         snd_card_free(card);
 852         return ret;
 853 }
 854
 855 void xen_snd_front_alsa_fini(struct xen_snd_front_info *front_info)
 856 {
 857         struct xen_snd_front_card_info *card_info;
 858         struct snd_card *card;
 859
 860         card_info = front_info->card_info;
 861         if (!card_info)
 862                 return;
 863
 864         card = card_info->card;
 865         if (!card)
 866                 return;
 867
 868         dev_dbg(&front_info->xb_dev->dev, "Removing virtual sound card %d\n",
 869                 card->number);
 870         snd_card_free(card);
 871
 872         /* Card_info will be freed when destroying front_info->xb_dev->dev. */
 873         card_info->card = NULL;
 874 }