cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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xen_snd_front_alsa.c (22417B)


      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}