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