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	.hw_params	= alsa_hw_params,
696	.hw_free	= alsa_hw_free,
697	.prepare	= alsa_prepare,
698	.trigger	= alsa_trigger,
699	.pointer	= alsa_pointer,
700	.copy_user	= alsa_pb_copy_user,
701	.copy_kernel	= alsa_pb_copy_kernel,
702	.fill_silence	= alsa_pb_fill_silence,
703};
704
705static const struct snd_pcm_ops snd_drv_alsa_capture_ops = {
706	.open		= alsa_open,
707	.close		= alsa_close,
708	.hw_params	= alsa_hw_params,
709	.hw_free	= alsa_hw_free,
710	.prepare	= alsa_prepare,
711	.trigger	= alsa_trigger,
712	.pointer	= alsa_pointer,
713	.copy_user	= alsa_cap_copy_user,
714	.copy_kernel	= alsa_cap_copy_kernel,
715};
716
717static int new_pcm_instance(struct xen_snd_front_card_info *card_info,
718			    struct xen_front_cfg_pcm_instance *instance_cfg,
719			    struct xen_snd_front_pcm_instance_info *pcm_instance_info)
720{
721	struct snd_pcm *pcm;
722	int ret, i;
723
724	dev_dbg(&card_info->front_info->xb_dev->dev,
725		"New PCM device \"%s\" with id %d playback %d capture %d",
726		instance_cfg->name,
727		instance_cfg->device_id,
728		instance_cfg->num_streams_pb,
729		instance_cfg->num_streams_cap);
730
731	pcm_instance_info->card_info = card_info;
732
733	pcm_instance_info->pcm_hw = instance_cfg->pcm_hw;
734
735	if (instance_cfg->num_streams_pb) {
736		pcm_instance_info->streams_pb =
737				devm_kcalloc(&card_info->card->card_dev,
738					     instance_cfg->num_streams_pb,
739					     sizeof(struct xen_snd_front_pcm_stream_info),
740					     GFP_KERNEL);
741		if (!pcm_instance_info->streams_pb)
742			return -ENOMEM;
743	}
744
745	if (instance_cfg->num_streams_cap) {
746		pcm_instance_info->streams_cap =
747				devm_kcalloc(&card_info->card->card_dev,
748					     instance_cfg->num_streams_cap,
749					     sizeof(struct xen_snd_front_pcm_stream_info),
750					     GFP_KERNEL);
751		if (!pcm_instance_info->streams_cap)
752			return -ENOMEM;
753	}
754
755	pcm_instance_info->num_pcm_streams_pb =
756			instance_cfg->num_streams_pb;
757	pcm_instance_info->num_pcm_streams_cap =
758			instance_cfg->num_streams_cap;
759
760	for (i = 0; i < pcm_instance_info->num_pcm_streams_pb; i++) {
761		pcm_instance_info->streams_pb[i].pcm_hw =
762			instance_cfg->streams_pb[i].pcm_hw;
763		pcm_instance_info->streams_pb[i].index =
764			instance_cfg->streams_pb[i].index;
765	}
766
767	for (i = 0; i < pcm_instance_info->num_pcm_streams_cap; i++) {
768		pcm_instance_info->streams_cap[i].pcm_hw =
769			instance_cfg->streams_cap[i].pcm_hw;
770		pcm_instance_info->streams_cap[i].index =
771			instance_cfg->streams_cap[i].index;
772	}
773
774	ret = snd_pcm_new(card_info->card, instance_cfg->name,
775			  instance_cfg->device_id,
776			  instance_cfg->num_streams_pb,
777			  instance_cfg->num_streams_cap,
778			  &pcm);
779	if (ret < 0)
780		return ret;
781
782	pcm->private_data = pcm_instance_info;
783	pcm->info_flags = 0;
784	/* we want to handle all PCM operations in non-atomic context */
785	pcm->nonatomic = true;
786	strncpy(pcm->name, "Virtual card PCM", sizeof(pcm->name));
787
788	if (instance_cfg->num_streams_pb)
789		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
790				&snd_drv_alsa_playback_ops);
791
792	if (instance_cfg->num_streams_cap)
793		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
794				&snd_drv_alsa_capture_ops);
795
796	pcm_instance_info->pcm = pcm;
797	return 0;
798}
799
800int xen_snd_front_alsa_init(struct xen_snd_front_info *front_info)
801{
802	struct device *dev = &front_info->xb_dev->dev;
803	struct xen_front_cfg_card *cfg = &front_info->cfg;
804	struct xen_snd_front_card_info *card_info;
805	struct snd_card *card;
806	int ret, i;
807
808	dev_dbg(dev, "Creating virtual sound card\n");
809
810	ret = snd_card_new(dev, 0, XENSND_DRIVER_NAME, THIS_MODULE,
811			   sizeof(struct xen_snd_front_card_info), &card);
812	if (ret < 0)
813		return ret;
814
815	card_info = card->private_data;
816	card_info->front_info = front_info;
817	front_info->card_info = card_info;
818	card_info->card = card;
819	card_info->pcm_instances =
820			devm_kcalloc(dev, cfg->num_pcm_instances,
821				     sizeof(struct xen_snd_front_pcm_instance_info),
822				     GFP_KERNEL);
823	if (!card_info->pcm_instances) {
824		ret = -ENOMEM;
825		goto fail;
826	}
827
828	card_info->num_pcm_instances = cfg->num_pcm_instances;
829	card_info->pcm_hw = cfg->pcm_hw;
830
831	for (i = 0; i < cfg->num_pcm_instances; i++) {
832		ret = new_pcm_instance(card_info, &cfg->pcm_instances[i],
833				       &card_info->pcm_instances[i]);
834		if (ret < 0)
835			goto fail;
836	}
837
838	strncpy(card->driver, XENSND_DRIVER_NAME, sizeof(card->driver));
839	strncpy(card->shortname, cfg->name_short, sizeof(card->shortname));
840	strncpy(card->longname, cfg->name_long, sizeof(card->longname));
841
842	ret = snd_card_register(card);
843	if (ret < 0)
844		goto fail;
845
846	return 0;
847
848fail:
849	snd_card_free(card);
850	return ret;
851}
852
853void xen_snd_front_alsa_fini(struct xen_snd_front_info *front_info)
854{
855	struct xen_snd_front_card_info *card_info;
856	struct snd_card *card;
857
858	card_info = front_info->card_info;
859	if (!card_info)
860		return;
861
862	card = card_info->card;
863	if (!card)
864		return;
865
866	dev_dbg(&front_info->xb_dev->dev, "Removing virtual sound card %d\n",
867		card->number);
868	snd_card_free(card);
869
870	/* Card_info will be freed when destroying front_info->xb_dev->dev. */
871	card_info->card = NULL;
872}