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0001 // SPDX-License-Identifier: GPL-2.0 OR MIT
0002 
0003 /*
0004  * Xen para-virtual sound device
0005  *
0006  * Copyright (C) 2016-2018 EPAM Systems Inc.
0007  *
0008  * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
0009  */
0010 
0011 #include <linux/platform_device.h>
0012 
0013 #include <sound/core.h>
0014 #include <sound/pcm.h>
0015 #include <sound/pcm_params.h>
0016 
0017 #include <xen/xenbus.h>
0018 #include <xen/xen-front-pgdir-shbuf.h>
0019 
0020 #include "xen_snd_front.h"
0021 #include "xen_snd_front_alsa.h"
0022 #include "xen_snd_front_cfg.h"
0023 #include "xen_snd_front_evtchnl.h"
0024 
0025 struct xen_snd_front_pcm_stream_info {
0026     struct xen_snd_front_info *front_info;
0027     struct xen_snd_front_evtchnl_pair *evt_pair;
0028 
0029     /* This is the shared buffer with its backing storage. */
0030     struct xen_front_pgdir_shbuf shbuf;
0031     u8 *buffer;
0032     size_t buffer_sz;
0033     int num_pages;
0034     struct page **pages;
0035 
0036     int index;
0037 
0038     bool is_open;
0039     struct snd_pcm_hardware pcm_hw;
0040 
0041     /* Number of processed frames as reported by the backend. */
0042     snd_pcm_uframes_t be_cur_frame;
0043     /* Current HW pointer to be reported via .period callback. */
0044     atomic_t hw_ptr;
0045     /* Modulo of the number of processed frames - for period detection. */
0046     u32 out_frames;
0047 };
0048 
0049 struct xen_snd_front_pcm_instance_info {
0050     struct xen_snd_front_card_info *card_info;
0051     struct snd_pcm *pcm;
0052     struct snd_pcm_hardware pcm_hw;
0053     int num_pcm_streams_pb;
0054     struct xen_snd_front_pcm_stream_info *streams_pb;
0055     int num_pcm_streams_cap;
0056     struct xen_snd_front_pcm_stream_info *streams_cap;
0057 };
0058 
0059 struct xen_snd_front_card_info {
0060     struct xen_snd_front_info *front_info;
0061     struct snd_card *card;
0062     struct snd_pcm_hardware pcm_hw;
0063     int num_pcm_instances;
0064     struct xen_snd_front_pcm_instance_info *pcm_instances;
0065 };
0066 
0067 struct alsa_sndif_sample_format {
0068     u8 sndif;
0069     snd_pcm_format_t alsa;
0070 };
0071 
0072 struct alsa_sndif_hw_param {
0073     u8 sndif;
0074     snd_pcm_hw_param_t alsa;
0075 };
0076 
0077 static const struct alsa_sndif_sample_format ALSA_SNDIF_FORMATS[] = {
0078     {
0079         .sndif = XENSND_PCM_FORMAT_U8,
0080         .alsa = SNDRV_PCM_FORMAT_U8
0081     },
0082     {
0083         .sndif = XENSND_PCM_FORMAT_S8,
0084         .alsa = SNDRV_PCM_FORMAT_S8
0085     },
0086     {
0087         .sndif = XENSND_PCM_FORMAT_U16_LE,
0088         .alsa = SNDRV_PCM_FORMAT_U16_LE
0089     },
0090     {
0091         .sndif = XENSND_PCM_FORMAT_U16_BE,
0092         .alsa = SNDRV_PCM_FORMAT_U16_BE
0093     },
0094     {
0095         .sndif = XENSND_PCM_FORMAT_S16_LE,
0096         .alsa = SNDRV_PCM_FORMAT_S16_LE
0097     },
0098     {
0099         .sndif = XENSND_PCM_FORMAT_S16_BE,
0100         .alsa = SNDRV_PCM_FORMAT_S16_BE
0101     },
0102     {
0103         .sndif = XENSND_PCM_FORMAT_U24_LE,
0104         .alsa = SNDRV_PCM_FORMAT_U24_LE
0105     },
0106     {
0107         .sndif = XENSND_PCM_FORMAT_U24_BE,
0108         .alsa = SNDRV_PCM_FORMAT_U24_BE
0109     },
0110     {
0111         .sndif = XENSND_PCM_FORMAT_S24_LE,
0112         .alsa = SNDRV_PCM_FORMAT_S24_LE
0113     },
0114     {
0115         .sndif = XENSND_PCM_FORMAT_S24_BE,
0116         .alsa = SNDRV_PCM_FORMAT_S24_BE
0117     },
0118     {
0119         .sndif = XENSND_PCM_FORMAT_U32_LE,
0120         .alsa = SNDRV_PCM_FORMAT_U32_LE
0121     },
0122     {
0123         .sndif = XENSND_PCM_FORMAT_U32_BE,
0124         .alsa = SNDRV_PCM_FORMAT_U32_BE
0125     },
0126     {
0127         .sndif = XENSND_PCM_FORMAT_S32_LE,
0128         .alsa = SNDRV_PCM_FORMAT_S32_LE
0129     },
0130     {
0131         .sndif = XENSND_PCM_FORMAT_S32_BE,
0132         .alsa = SNDRV_PCM_FORMAT_S32_BE
0133     },
0134     {
0135         .sndif = XENSND_PCM_FORMAT_A_LAW,
0136         .alsa = SNDRV_PCM_FORMAT_A_LAW
0137     },
0138     {
0139         .sndif = XENSND_PCM_FORMAT_MU_LAW,
0140         .alsa = SNDRV_PCM_FORMAT_MU_LAW
0141     },
0142     {
0143         .sndif = XENSND_PCM_FORMAT_F32_LE,
0144         .alsa = SNDRV_PCM_FORMAT_FLOAT_LE
0145     },
0146     {
0147         .sndif = XENSND_PCM_FORMAT_F32_BE,
0148         .alsa = SNDRV_PCM_FORMAT_FLOAT_BE
0149     },
0150     {
0151         .sndif = XENSND_PCM_FORMAT_F64_LE,
0152         .alsa = SNDRV_PCM_FORMAT_FLOAT64_LE
0153     },
0154     {
0155         .sndif = XENSND_PCM_FORMAT_F64_BE,
0156         .alsa = SNDRV_PCM_FORMAT_FLOAT64_BE
0157     },
0158     {
0159         .sndif = XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE,
0160         .alsa = SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE
0161     },
0162     {
0163         .sndif = XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE,
0164         .alsa = SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE
0165     },
0166     {
0167         .sndif = XENSND_PCM_FORMAT_IMA_ADPCM,
0168         .alsa = SNDRV_PCM_FORMAT_IMA_ADPCM
0169     },
0170     {
0171         .sndif = XENSND_PCM_FORMAT_MPEG,
0172         .alsa = SNDRV_PCM_FORMAT_MPEG
0173     },
0174     {
0175         .sndif = XENSND_PCM_FORMAT_GSM,
0176         .alsa = SNDRV_PCM_FORMAT_GSM
0177     },
0178 };
0179 
0180 static int to_sndif_format(snd_pcm_format_t format)
0181 {
0182     int i;
0183 
0184     for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
0185         if (ALSA_SNDIF_FORMATS[i].alsa == format)
0186             return ALSA_SNDIF_FORMATS[i].sndif;
0187 
0188     return -EINVAL;
0189 }
0190 
0191 static u64 to_sndif_formats_mask(u64 alsa_formats)
0192 {
0193     u64 mask;
0194     int i;
0195 
0196     mask = 0;
0197     for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
0198         if (pcm_format_to_bits(ALSA_SNDIF_FORMATS[i].alsa) & alsa_formats)
0199             mask |= BIT_ULL(ALSA_SNDIF_FORMATS[i].sndif);
0200 
0201     return mask;
0202 }
0203 
0204 static u64 to_alsa_formats_mask(u64 sndif_formats)
0205 {
0206     u64 mask;
0207     int i;
0208 
0209     mask = 0;
0210     for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
0211         if (BIT_ULL(ALSA_SNDIF_FORMATS[i].sndif) & sndif_formats)
0212             mask |= pcm_format_to_bits(ALSA_SNDIF_FORMATS[i].alsa);
0213 
0214     return mask;
0215 }
0216 
0217 static void stream_clear(struct xen_snd_front_pcm_stream_info *stream)
0218 {
0219     stream->is_open = false;
0220     stream->be_cur_frame = 0;
0221     stream->out_frames = 0;
0222     atomic_set(&stream->hw_ptr, 0);
0223     xen_snd_front_evtchnl_pair_clear(stream->evt_pair);
0224     memset(&stream->shbuf, 0, sizeof(stream->shbuf));
0225     stream->buffer = NULL;
0226     stream->buffer_sz = 0;
0227     stream->pages = NULL;
0228     stream->num_pages = 0;
0229 }
0230 
0231 static void stream_free(struct xen_snd_front_pcm_stream_info *stream)
0232 {
0233     xen_front_pgdir_shbuf_unmap(&stream->shbuf);
0234     xen_front_pgdir_shbuf_free(&stream->shbuf);
0235     if (stream->buffer)
0236         free_pages_exact(stream->buffer, stream->buffer_sz);
0237     kfree(stream->pages);
0238     stream_clear(stream);
0239 }
0240 
0241 static struct xen_snd_front_pcm_stream_info *
0242 stream_get(struct snd_pcm_substream *substream)
0243 {
0244     struct xen_snd_front_pcm_instance_info *pcm_instance =
0245             snd_pcm_substream_chip(substream);
0246     struct xen_snd_front_pcm_stream_info *stream;
0247 
0248     if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
0249         stream = &pcm_instance->streams_pb[substream->number];
0250     else
0251         stream = &pcm_instance->streams_cap[substream->number];
0252 
0253     return stream;
0254 }
0255 
0256 static int alsa_hw_rule(struct snd_pcm_hw_params *params,
0257             struct snd_pcm_hw_rule *rule)
0258 {
0259     struct xen_snd_front_pcm_stream_info *stream = rule->private;
0260     struct device *dev = &stream->front_info->xb_dev->dev;
0261     struct snd_mask *formats =
0262             hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
0263     struct snd_interval *rates =
0264             hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
0265     struct snd_interval *channels =
0266             hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
0267     struct snd_interval *period =
0268             hw_param_interval(params,
0269                       SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
0270     struct snd_interval *buffer =
0271             hw_param_interval(params,
0272                       SNDRV_PCM_HW_PARAM_BUFFER_SIZE);
0273     struct xensnd_query_hw_param req;
0274     struct xensnd_query_hw_param resp;
0275     struct snd_interval interval;
0276     struct snd_mask mask;
0277     u64 sndif_formats;
0278     int changed, ret;
0279 
0280     /* Collect all the values we need for the query. */
0281 
0282     req.formats = to_sndif_formats_mask((u64)formats->bits[0] |
0283                         (u64)(formats->bits[1]) << 32);
0284 
0285     req.rates.min = rates->min;
0286     req.rates.max = rates->max;
0287 
0288     req.channels.min = channels->min;
0289     req.channels.max = channels->max;
0290 
0291     req.buffer.min = buffer->min;
0292     req.buffer.max = buffer->max;
0293 
0294     req.period.min = period->min;
0295     req.period.max = period->max;
0296 
0297     ret = xen_snd_front_stream_query_hw_param(&stream->evt_pair->req,
0298                           &req, &resp);
0299     if (ret < 0) {
0300         /* Check if this is due to backend communication error. */
0301         if (ret == -EIO || ret == -ETIMEDOUT)
0302             dev_err(dev, "Failed to query ALSA HW parameters\n");
0303         return ret;
0304     }
0305 
0306     /* Refine HW parameters after the query. */
0307     changed  = 0;
0308 
0309     sndif_formats = to_alsa_formats_mask(resp.formats);
0310     snd_mask_none(&mask);
0311     mask.bits[0] = (u32)sndif_formats;
0312     mask.bits[1] = (u32)(sndif_formats >> 32);
0313     ret = snd_mask_refine(formats, &mask);
0314     if (ret < 0)
0315         return ret;
0316     changed |= ret;
0317 
0318     interval.openmin = 0;
0319     interval.openmax = 0;
0320     interval.integer = 1;
0321 
0322     interval.min = resp.rates.min;
0323     interval.max = resp.rates.max;
0324     ret = snd_interval_refine(rates, &interval);
0325     if (ret < 0)
0326         return ret;
0327     changed |= ret;
0328 
0329     interval.min = resp.channels.min;
0330     interval.max = resp.channels.max;
0331     ret = snd_interval_refine(channels, &interval);
0332     if (ret < 0)
0333         return ret;
0334     changed |= ret;
0335 
0336     interval.min = resp.buffer.min;
0337     interval.max = resp.buffer.max;
0338     ret = snd_interval_refine(buffer, &interval);
0339     if (ret < 0)
0340         return ret;
0341     changed |= ret;
0342 
0343     interval.min = resp.period.min;
0344     interval.max = resp.period.max;
0345     ret = snd_interval_refine(period, &interval);
0346     if (ret < 0)
0347         return ret;
0348     changed |= ret;
0349 
0350     return changed;
0351 }
0352 
0353 static int alsa_open(struct snd_pcm_substream *substream)
0354 {
0355     struct xen_snd_front_pcm_instance_info *pcm_instance =
0356             snd_pcm_substream_chip(substream);
0357     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0358     struct snd_pcm_runtime *runtime = substream->runtime;
0359     struct xen_snd_front_info *front_info =
0360             pcm_instance->card_info->front_info;
0361     struct device *dev = &front_info->xb_dev->dev;
0362     int ret;
0363 
0364     /*
0365      * Return our HW properties: override defaults with those configured
0366      * via XenStore.
0367      */
0368     runtime->hw = stream->pcm_hw;
0369     runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
0370                   SNDRV_PCM_INFO_MMAP_VALID |
0371                   SNDRV_PCM_INFO_DOUBLE |
0372                   SNDRV_PCM_INFO_BATCH |
0373                   SNDRV_PCM_INFO_NONINTERLEAVED |
0374                   SNDRV_PCM_INFO_RESUME |
0375                   SNDRV_PCM_INFO_PAUSE);
0376     runtime->hw.info |= SNDRV_PCM_INFO_INTERLEAVED;
0377 
0378     stream->evt_pair = &front_info->evt_pairs[stream->index];
0379 
0380     stream->front_info = front_info;
0381 
0382     stream->evt_pair->evt.u.evt.substream = substream;
0383 
0384     stream_clear(stream);
0385 
0386     xen_snd_front_evtchnl_pair_set_connected(stream->evt_pair, true);
0387 
0388     ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
0389                   alsa_hw_rule, stream,
0390                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
0391     if (ret) {
0392         dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_FORMAT\n");
0393         return ret;
0394     }
0395 
0396     ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
0397                   alsa_hw_rule, stream,
0398                   SNDRV_PCM_HW_PARAM_RATE, -1);
0399     if (ret) {
0400         dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_RATE\n");
0401         return ret;
0402     }
0403 
0404     ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
0405                   alsa_hw_rule, stream,
0406                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
0407     if (ret) {
0408         dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_CHANNELS\n");
0409         return ret;
0410     }
0411 
0412     ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
0413                   alsa_hw_rule, stream,
0414                   SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
0415     if (ret) {
0416         dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_PERIOD_SIZE\n");
0417         return ret;
0418     }
0419 
0420     ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
0421                   alsa_hw_rule, stream,
0422                   SNDRV_PCM_HW_PARAM_BUFFER_SIZE, -1);
0423     if (ret) {
0424         dev_err(dev, "Failed to add HW rule for SNDRV_PCM_HW_PARAM_BUFFER_SIZE\n");
0425         return ret;
0426     }
0427 
0428     return 0;
0429 }
0430 
0431 static int alsa_close(struct snd_pcm_substream *substream)
0432 {
0433     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0434 
0435     xen_snd_front_evtchnl_pair_set_connected(stream->evt_pair, false);
0436     return 0;
0437 }
0438 
0439 static int shbuf_setup_backstore(struct xen_snd_front_pcm_stream_info *stream,
0440                  size_t buffer_sz)
0441 {
0442     int i;
0443 
0444     stream->buffer = alloc_pages_exact(buffer_sz, GFP_KERNEL);
0445     if (!stream->buffer)
0446         return -ENOMEM;
0447 
0448     stream->buffer_sz = buffer_sz;
0449     stream->num_pages = DIV_ROUND_UP(stream->buffer_sz, PAGE_SIZE);
0450     stream->pages = kcalloc(stream->num_pages, sizeof(struct page *),
0451                 GFP_KERNEL);
0452     if (!stream->pages)
0453         return -ENOMEM;
0454 
0455     for (i = 0; i < stream->num_pages; i++)
0456         stream->pages[i] = virt_to_page(stream->buffer + i * PAGE_SIZE);
0457 
0458     return 0;
0459 }
0460 
0461 static int alsa_hw_params(struct snd_pcm_substream *substream,
0462               struct snd_pcm_hw_params *params)
0463 {
0464     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0465     struct xen_snd_front_info *front_info = stream->front_info;
0466     struct xen_front_pgdir_shbuf_cfg buf_cfg;
0467     int ret;
0468 
0469     /*
0470      * This callback may be called multiple times,
0471      * so free the previously allocated shared buffer if any.
0472      */
0473     stream_free(stream);
0474     ret = shbuf_setup_backstore(stream, params_buffer_bytes(params));
0475     if (ret < 0)
0476         goto fail;
0477 
0478     memset(&buf_cfg, 0, sizeof(buf_cfg));
0479     buf_cfg.xb_dev = front_info->xb_dev;
0480     buf_cfg.pgdir = &stream->shbuf;
0481     buf_cfg.num_pages = stream->num_pages;
0482     buf_cfg.pages = stream->pages;
0483 
0484     ret = xen_front_pgdir_shbuf_alloc(&buf_cfg);
0485     if (ret < 0)
0486         goto fail;
0487 
0488     ret = xen_front_pgdir_shbuf_map(&stream->shbuf);
0489     if (ret < 0)
0490         goto fail;
0491 
0492     return 0;
0493 
0494 fail:
0495     stream_free(stream);
0496     dev_err(&front_info->xb_dev->dev,
0497         "Failed to allocate buffers for stream with index %d\n",
0498         stream->index);
0499     return ret;
0500 }
0501 
0502 static int alsa_hw_free(struct snd_pcm_substream *substream)
0503 {
0504     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0505     int ret;
0506 
0507     ret = xen_snd_front_stream_close(&stream->evt_pair->req);
0508     stream_free(stream);
0509     return ret;
0510 }
0511 
0512 static int alsa_prepare(struct snd_pcm_substream *substream)
0513 {
0514     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0515 
0516     if (!stream->is_open) {
0517         struct snd_pcm_runtime *runtime = substream->runtime;
0518         u8 sndif_format;
0519         int ret;
0520 
0521         ret = to_sndif_format(runtime->format);
0522         if (ret < 0) {
0523             dev_err(&stream->front_info->xb_dev->dev,
0524                 "Unsupported sample format: %d\n",
0525                 runtime->format);
0526             return ret;
0527         }
0528         sndif_format = ret;
0529 
0530         ret = xen_snd_front_stream_prepare(&stream->evt_pair->req,
0531                            &stream->shbuf,
0532                            sndif_format,
0533                            runtime->channels,
0534                            runtime->rate,
0535                            snd_pcm_lib_buffer_bytes(substream),
0536                            snd_pcm_lib_period_bytes(substream));
0537         if (ret < 0)
0538             return ret;
0539 
0540         stream->is_open = true;
0541     }
0542 
0543     return 0;
0544 }
0545 
0546 static int alsa_trigger(struct snd_pcm_substream *substream, int cmd)
0547 {
0548     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0549     int type;
0550 
0551     switch (cmd) {
0552     case SNDRV_PCM_TRIGGER_START:
0553         type = XENSND_OP_TRIGGER_START;
0554         break;
0555 
0556     case SNDRV_PCM_TRIGGER_RESUME:
0557         type = XENSND_OP_TRIGGER_RESUME;
0558         break;
0559 
0560     case SNDRV_PCM_TRIGGER_STOP:
0561         type = XENSND_OP_TRIGGER_STOP;
0562         break;
0563 
0564     case SNDRV_PCM_TRIGGER_SUSPEND:
0565         type = XENSND_OP_TRIGGER_PAUSE;
0566         break;
0567 
0568     default:
0569         return -EINVAL;
0570     }
0571 
0572     return xen_snd_front_stream_trigger(&stream->evt_pair->req, type);
0573 }
0574 
0575 void xen_snd_front_alsa_handle_cur_pos(struct xen_snd_front_evtchnl *evtchnl,
0576                        u64 pos_bytes)
0577 {
0578     struct snd_pcm_substream *substream = evtchnl->u.evt.substream;
0579     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0580     snd_pcm_uframes_t delta, new_hw_ptr, cur_frame;
0581 
0582     cur_frame = bytes_to_frames(substream->runtime, pos_bytes);
0583 
0584     delta = cur_frame - stream->be_cur_frame;
0585     stream->be_cur_frame = cur_frame;
0586 
0587     new_hw_ptr = (snd_pcm_uframes_t)atomic_read(&stream->hw_ptr);
0588     new_hw_ptr = (new_hw_ptr + delta) % substream->runtime->buffer_size;
0589     atomic_set(&stream->hw_ptr, (int)new_hw_ptr);
0590 
0591     stream->out_frames += delta;
0592     if (stream->out_frames > substream->runtime->period_size) {
0593         stream->out_frames %= substream->runtime->period_size;
0594         snd_pcm_period_elapsed(substream);
0595     }
0596 }
0597 
0598 static snd_pcm_uframes_t alsa_pointer(struct snd_pcm_substream *substream)
0599 {
0600     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0601 
0602     return (snd_pcm_uframes_t)atomic_read(&stream->hw_ptr);
0603 }
0604 
0605 static int alsa_pb_copy_user(struct snd_pcm_substream *substream,
0606                  int channel, unsigned long pos, void __user *src,
0607                  unsigned long count)
0608 {
0609     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0610 
0611     if (unlikely(pos + count > stream->buffer_sz))
0612         return -EINVAL;
0613 
0614     if (copy_from_user(stream->buffer + pos, src, count))
0615         return -EFAULT;
0616 
0617     return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
0618 }
0619 
0620 static int alsa_pb_copy_kernel(struct snd_pcm_substream *substream,
0621                    int channel, unsigned long pos, void *src,
0622                    unsigned long count)
0623 {
0624     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0625 
0626     if (unlikely(pos + count > stream->buffer_sz))
0627         return -EINVAL;
0628 
0629     memcpy(stream->buffer + pos, src, count);
0630 
0631     return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
0632 }
0633 
0634 static int alsa_cap_copy_user(struct snd_pcm_substream *substream,
0635                   int channel, unsigned long pos, void __user *dst,
0636                   unsigned long count)
0637 {
0638     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0639     int ret;
0640 
0641     if (unlikely(pos + count > stream->buffer_sz))
0642         return -EINVAL;
0643 
0644     ret = xen_snd_front_stream_read(&stream->evt_pair->req, pos, count);
0645     if (ret < 0)
0646         return ret;
0647 
0648     return copy_to_user(dst, stream->buffer + pos, count) ?
0649         -EFAULT : 0;
0650 }
0651 
0652 static int alsa_cap_copy_kernel(struct snd_pcm_substream *substream,
0653                 int channel, unsigned long pos, void *dst,
0654                 unsigned long count)
0655 {
0656     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0657     int ret;
0658 
0659     if (unlikely(pos + count > stream->buffer_sz))
0660         return -EINVAL;
0661 
0662     ret = xen_snd_front_stream_read(&stream->evt_pair->req, pos, count);
0663     if (ret < 0)
0664         return ret;
0665 
0666     memcpy(dst, stream->buffer + pos, count);
0667 
0668     return 0;
0669 }
0670 
0671 static int alsa_pb_fill_silence(struct snd_pcm_substream *substream,
0672                 int channel, unsigned long pos,
0673                 unsigned long count)
0674 {
0675     struct xen_snd_front_pcm_stream_info *stream = stream_get(substream);
0676 
0677     if (unlikely(pos + count > stream->buffer_sz))
0678         return -EINVAL;
0679 
0680     memset(stream->buffer + pos, 0, count);
0681 
0682     return xen_snd_front_stream_write(&stream->evt_pair->req, pos, count);
0683 }
0684 
0685 /*
0686  * FIXME: The mmaped data transfer is asynchronous and there is no
0687  * ack signal from user-space when it is done. This is the
0688  * reason it is not implemented in the PV driver as we do need
0689  * to know when the buffer can be transferred to the backend.
0690  */
0691 
0692 static const struct snd_pcm_ops snd_drv_alsa_playback_ops = {
0693     .open       = alsa_open,
0694     .close      = alsa_close,
0695     .hw_params  = alsa_hw_params,
0696     .hw_free    = alsa_hw_free,
0697     .prepare    = alsa_prepare,
0698     .trigger    = alsa_trigger,
0699     .pointer    = alsa_pointer,
0700     .copy_user  = alsa_pb_copy_user,
0701     .copy_kernel    = alsa_pb_copy_kernel,
0702     .fill_silence   = alsa_pb_fill_silence,
0703 };
0704 
0705 static const struct snd_pcm_ops snd_drv_alsa_capture_ops = {
0706     .open       = alsa_open,
0707     .close      = alsa_close,
0708     .hw_params  = alsa_hw_params,
0709     .hw_free    = alsa_hw_free,
0710     .prepare    = alsa_prepare,
0711     .trigger    = alsa_trigger,
0712     .pointer    = alsa_pointer,
0713     .copy_user  = alsa_cap_copy_user,
0714     .copy_kernel    = alsa_cap_copy_kernel,
0715 };
0716 
0717 static int new_pcm_instance(struct xen_snd_front_card_info *card_info,
0718                 struct xen_front_cfg_pcm_instance *instance_cfg,
0719                 struct xen_snd_front_pcm_instance_info *pcm_instance_info)
0720 {
0721     struct snd_pcm *pcm;
0722     int ret, i;
0723 
0724     dev_dbg(&card_info->front_info->xb_dev->dev,
0725         "New PCM device \"%s\" with id %d playback %d capture %d",
0726         instance_cfg->name,
0727         instance_cfg->device_id,
0728         instance_cfg->num_streams_pb,
0729         instance_cfg->num_streams_cap);
0730 
0731     pcm_instance_info->card_info = card_info;
0732 
0733     pcm_instance_info->pcm_hw = instance_cfg->pcm_hw;
0734 
0735     if (instance_cfg->num_streams_pb) {
0736         pcm_instance_info->streams_pb =
0737                 devm_kcalloc(&card_info->card->card_dev,
0738                          instance_cfg->num_streams_pb,
0739                          sizeof(struct xen_snd_front_pcm_stream_info),
0740                          GFP_KERNEL);
0741         if (!pcm_instance_info->streams_pb)
0742             return -ENOMEM;
0743     }
0744 
0745     if (instance_cfg->num_streams_cap) {
0746         pcm_instance_info->streams_cap =
0747                 devm_kcalloc(&card_info->card->card_dev,
0748                          instance_cfg->num_streams_cap,
0749                          sizeof(struct xen_snd_front_pcm_stream_info),
0750                          GFP_KERNEL);
0751         if (!pcm_instance_info->streams_cap)
0752             return -ENOMEM;
0753     }
0754 
0755     pcm_instance_info->num_pcm_streams_pb =
0756             instance_cfg->num_streams_pb;
0757     pcm_instance_info->num_pcm_streams_cap =
0758             instance_cfg->num_streams_cap;
0759 
0760     for (i = 0; i < pcm_instance_info->num_pcm_streams_pb; i++) {
0761         pcm_instance_info->streams_pb[i].pcm_hw =
0762             instance_cfg->streams_pb[i].pcm_hw;
0763         pcm_instance_info->streams_pb[i].index =
0764             instance_cfg->streams_pb[i].index;
0765     }
0766 
0767     for (i = 0; i < pcm_instance_info->num_pcm_streams_cap; i++) {
0768         pcm_instance_info->streams_cap[i].pcm_hw =
0769             instance_cfg->streams_cap[i].pcm_hw;
0770         pcm_instance_info->streams_cap[i].index =
0771             instance_cfg->streams_cap[i].index;
0772     }
0773 
0774     ret = snd_pcm_new(card_info->card, instance_cfg->name,
0775               instance_cfg->device_id,
0776               instance_cfg->num_streams_pb,
0777               instance_cfg->num_streams_cap,
0778               &pcm);
0779     if (ret < 0)
0780         return ret;
0781 
0782     pcm->private_data = pcm_instance_info;
0783     pcm->info_flags = 0;
0784     /* we want to handle all PCM operations in non-atomic context */
0785     pcm->nonatomic = true;
0786     strncpy(pcm->name, "Virtual card PCM", sizeof(pcm->name));
0787 
0788     if (instance_cfg->num_streams_pb)
0789         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
0790                 &snd_drv_alsa_playback_ops);
0791 
0792     if (instance_cfg->num_streams_cap)
0793         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
0794                 &snd_drv_alsa_capture_ops);
0795 
0796     pcm_instance_info->pcm = pcm;
0797     return 0;
0798 }
0799 
0800 int xen_snd_front_alsa_init(struct xen_snd_front_info *front_info)
0801 {
0802     struct device *dev = &front_info->xb_dev->dev;
0803     struct xen_front_cfg_card *cfg = &front_info->cfg;
0804     struct xen_snd_front_card_info *card_info;
0805     struct snd_card *card;
0806     int ret, i;
0807 
0808     dev_dbg(dev, "Creating virtual sound card\n");
0809 
0810     ret = snd_card_new(dev, 0, XENSND_DRIVER_NAME, THIS_MODULE,
0811                sizeof(struct xen_snd_front_card_info), &card);
0812     if (ret < 0)
0813         return ret;
0814 
0815     card_info = card->private_data;
0816     card_info->front_info = front_info;
0817     front_info->card_info = card_info;
0818     card_info->card = card;
0819     card_info->pcm_instances =
0820             devm_kcalloc(dev, cfg->num_pcm_instances,
0821                      sizeof(struct xen_snd_front_pcm_instance_info),
0822                      GFP_KERNEL);
0823     if (!card_info->pcm_instances) {
0824         ret = -ENOMEM;
0825         goto fail;
0826     }
0827 
0828     card_info->num_pcm_instances = cfg->num_pcm_instances;
0829     card_info->pcm_hw = cfg->pcm_hw;
0830 
0831     for (i = 0; i < cfg->num_pcm_instances; i++) {
0832         ret = new_pcm_instance(card_info, &cfg->pcm_instances[i],
0833                        &card_info->pcm_instances[i]);
0834         if (ret < 0)
0835             goto fail;
0836     }
0837 
0838     strncpy(card->driver, XENSND_DRIVER_NAME, sizeof(card->driver));
0839     strncpy(card->shortname, cfg->name_short, sizeof(card->shortname));
0840     strncpy(card->longname, cfg->name_long, sizeof(card->longname));
0841 
0842     ret = snd_card_register(card);
0843     if (ret < 0)
0844         goto fail;
0845 
0846     return 0;
0847 
0848 fail:
0849     snd_card_free(card);
0850     return ret;
0851 }
0852 
0853 void xen_snd_front_alsa_fini(struct xen_snd_front_info *front_info)
0854 {
0855     struct xen_snd_front_card_info *card_info;
0856     struct snd_card *card;
0857 
0858     card_info = front_info->card_info;
0859     if (!card_info)
0860         return;
0861 
0862     card = card_info->card;
0863     if (!card)
0864         return;
0865 
0866     dev_dbg(&front_info->xb_dev->dev, "Removing virtual sound card %d\n",
0867         card->number);
0868     snd_card_free(card);
0869 
0870     /* Card_info will be freed when destroying front_info->xb_dev->dev. */
0871     card_info->card = NULL;
0872 }
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