linux/sound/xen/xen_snd_front_alsa.c
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   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
  25struct 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
  49struct 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
  59struct 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
  67struct alsa_sndif_sample_format {
  68        u8 sndif;
  69        snd_pcm_format_t alsa;
  70};
  71
  72struct alsa_sndif_hw_param {
  73        u8 sndif;
  74        snd_pcm_hw_param_t alsa;
  75};
  76
  77static 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
 180static 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
 191static 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 |= BIT_ULL(ALSA_SNDIF_FORMATS[i].sndif);
 200
 201        return mask;
 202}
 203
 204static 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 (BIT_ULL(ALSA_SNDIF_FORMATS[i].sndif) & sndif_formats)
 212                        mask |= pcm_format_to_bits(ALSA_SNDIF_FORMATS[i].alsa);
 213
 214        return mask;
 215}
 216
 217static 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
 231static 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
 241static struct xen_snd_front_pcm_stream_info *
 242stream_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
 256static 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
 353static 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
 431static 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
 439static 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
 461static 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
 494fail:
 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
 502static 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
 512static 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
 546static 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
 575void 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
 598static 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
 605static 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
 620static 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
 634static 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
 652static 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
 671static 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
 692static 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
 706static 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
 719static 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
 802int 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
 850fail:
 851        snd_card_free(card);
 852        return ret;
 853}
 854
 855void 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}
 875