linux/sound/core/pcm.c
Takashi Iwai f0061c18c1 ALSA: pcm: Avoid reference to status->state
In the PCM core and driver code, there are lots place referring to the
current PCM state via runtime->status->state.  This patch introduced a
local PCM state in runtime itself and replaces those references with
runtime->state.  It has improvements in two aspects:

- The reduction of a indirect access leads to more code optimization

- It avoids a possible (unexpected) modification of the state via mmap
  of the status record

The status->state is updated together with runtime->state, so that
user-space can still read the current state via mmap like before,
too.

This patch touches only the ALSA core code.  The changes in each
driver will follow in later patches.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220926135558.26580-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-09-27 08:44:05 +02:00

1247 lines
33 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Digital Audio (PCM) abstract layer
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*/
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/time.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/nospec.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/pcm.h>
#include <sound/timer.h>
#include <sound/control.h>
#include <sound/info.h>
#include "pcm_local.h"
MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
MODULE_LICENSE("GPL");
static LIST_HEAD(snd_pcm_devices);
static DEFINE_MUTEX(register_mutex);
#if IS_ENABLED(CONFIG_SND_PCM_OSS)
static LIST_HEAD(snd_pcm_notify_list);
#endif
static int snd_pcm_free(struct snd_pcm *pcm);
static int snd_pcm_dev_free(struct snd_device *device);
static int snd_pcm_dev_register(struct snd_device *device);
static int snd_pcm_dev_disconnect(struct snd_device *device);
static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
{
struct snd_pcm *pcm;
list_for_each_entry(pcm, &snd_pcm_devices, list) {
if (pcm->card == card && pcm->device == device)
return pcm;
}
return NULL;
}
static int snd_pcm_next(struct snd_card *card, int device)
{
struct snd_pcm *pcm;
list_for_each_entry(pcm, &snd_pcm_devices, list) {
if (pcm->card == card && pcm->device > device)
return pcm->device;
else if (pcm->card->number > card->number)
return -1;
}
return -1;
}
static int snd_pcm_add(struct snd_pcm *newpcm)
{
struct snd_pcm *pcm;
if (newpcm->internal)
return 0;
list_for_each_entry(pcm, &snd_pcm_devices, list) {
if (pcm->card == newpcm->card && pcm->device == newpcm->device)
return -EBUSY;
if (pcm->card->number > newpcm->card->number ||
(pcm->card == newpcm->card &&
pcm->device > newpcm->device)) {
list_add(&newpcm->list, pcm->list.prev);
return 0;
}
}
list_add_tail(&newpcm->list, &snd_pcm_devices);
return 0;
}
static int snd_pcm_control_ioctl(struct snd_card *card,
struct snd_ctl_file *control,
unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
{
int device;
if (get_user(device, (int __user *)arg))
return -EFAULT;
mutex_lock(&register_mutex);
device = snd_pcm_next(card, device);
mutex_unlock(&register_mutex);
if (put_user(device, (int __user *)arg))
return -EFAULT;
return 0;
}
case SNDRV_CTL_IOCTL_PCM_INFO:
{
struct snd_pcm_info __user *info;
unsigned int device, subdevice;
int stream;
struct snd_pcm *pcm;
struct snd_pcm_str *pstr;
struct snd_pcm_substream *substream;
int err;
info = (struct snd_pcm_info __user *)arg;
if (get_user(device, &info->device))
return -EFAULT;
if (get_user(stream, &info->stream))
return -EFAULT;
if (stream < 0 || stream > 1)
return -EINVAL;
stream = array_index_nospec(stream, 2);
if (get_user(subdevice, &info->subdevice))
return -EFAULT;
mutex_lock(&register_mutex);
pcm = snd_pcm_get(card, device);
if (pcm == NULL) {
err = -ENXIO;
goto _error;
}
pstr = &pcm->streams[stream];
if (pstr->substream_count == 0) {
err = -ENOENT;
goto _error;
}
if (subdevice >= pstr->substream_count) {
err = -ENXIO;
goto _error;
}
for (substream = pstr->substream; substream;
substream = substream->next)
if (substream->number == (int)subdevice)
break;
if (substream == NULL) {
err = -ENXIO;
goto _error;
}
mutex_lock(&pcm->open_mutex);
err = snd_pcm_info_user(substream, info);
mutex_unlock(&pcm->open_mutex);
_error:
mutex_unlock(&register_mutex);
return err;
}
case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
{
int val;
if (get_user(val, (int __user *)arg))
return -EFAULT;
control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
return 0;
}
}
return -ENOIOCTLCMD;
}
#define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
static const char * const snd_pcm_format_names[] = {
FORMAT(S8),
FORMAT(U8),
FORMAT(S16_LE),
FORMAT(S16_BE),
FORMAT(U16_LE),
FORMAT(U16_BE),
FORMAT(S24_LE),
FORMAT(S24_BE),
FORMAT(U24_LE),
FORMAT(U24_BE),
FORMAT(S32_LE),
FORMAT(S32_BE),
FORMAT(U32_LE),
FORMAT(U32_BE),
FORMAT(FLOAT_LE),
FORMAT(FLOAT_BE),
FORMAT(FLOAT64_LE),
FORMAT(FLOAT64_BE),
FORMAT(IEC958_SUBFRAME_LE),
FORMAT(IEC958_SUBFRAME_BE),
FORMAT(MU_LAW),
FORMAT(A_LAW),
FORMAT(IMA_ADPCM),
FORMAT(MPEG),
FORMAT(GSM),
FORMAT(SPECIAL),
FORMAT(S24_3LE),
FORMAT(S24_3BE),
FORMAT(U24_3LE),
FORMAT(U24_3BE),
FORMAT(S20_3LE),
FORMAT(S20_3BE),
FORMAT(U20_3LE),
FORMAT(U20_3BE),
FORMAT(S18_3LE),
FORMAT(S18_3BE),
FORMAT(U18_3LE),
FORMAT(U18_3BE),
FORMAT(G723_24),
FORMAT(G723_24_1B),
FORMAT(G723_40),
FORMAT(G723_40_1B),
FORMAT(DSD_U8),
FORMAT(DSD_U16_LE),
FORMAT(DSD_U32_LE),
FORMAT(DSD_U16_BE),
FORMAT(DSD_U32_BE),
};
/**
* snd_pcm_format_name - Return a name string for the given PCM format
* @format: PCM format
*
* Return: the format name string
*/
const char *snd_pcm_format_name(snd_pcm_format_t format)
{
if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
return "Unknown";
return snd_pcm_format_names[(__force unsigned int)format];
}
EXPORT_SYMBOL_GPL(snd_pcm_format_name);
#ifdef CONFIG_SND_VERBOSE_PROCFS
#define STATE(v) [SNDRV_PCM_STATE_##v] = #v
#define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
#define READY(v) [SNDRV_PCM_READY_##v] = #v
#define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
#define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
#define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
#define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
#define START(v) [SNDRV_PCM_START_##v] = #v
#define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
static const char * const snd_pcm_stream_names[] = {
STREAM(PLAYBACK),
STREAM(CAPTURE),
};
static const char * const snd_pcm_state_names[] = {
STATE(OPEN),
STATE(SETUP),
STATE(PREPARED),
STATE(RUNNING),
STATE(XRUN),
STATE(DRAINING),
STATE(PAUSED),
STATE(SUSPENDED),
};
static const char * const snd_pcm_access_names[] = {
ACCESS(MMAP_INTERLEAVED),
ACCESS(MMAP_NONINTERLEAVED),
ACCESS(MMAP_COMPLEX),
ACCESS(RW_INTERLEAVED),
ACCESS(RW_NONINTERLEAVED),
};
static const char * const snd_pcm_subformat_names[] = {
SUBFORMAT(STD),
};
static const char * const snd_pcm_tstamp_mode_names[] = {
TSTAMP(NONE),
TSTAMP(ENABLE),
};
static const char *snd_pcm_stream_name(int stream)
{
return snd_pcm_stream_names[stream];
}
static const char *snd_pcm_access_name(snd_pcm_access_t access)
{
return snd_pcm_access_names[(__force int)access];
}
static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
{
return snd_pcm_subformat_names[(__force int)subformat];
}
static const char *snd_pcm_tstamp_mode_name(int mode)
{
return snd_pcm_tstamp_mode_names[mode];
}
static const char *snd_pcm_state_name(snd_pcm_state_t state)
{
return snd_pcm_state_names[(__force int)state];
}
#if IS_ENABLED(CONFIG_SND_PCM_OSS)
#include <linux/soundcard.h>
static const char *snd_pcm_oss_format_name(int format)
{
switch (format) {
case AFMT_MU_LAW:
return "MU_LAW";
case AFMT_A_LAW:
return "A_LAW";
case AFMT_IMA_ADPCM:
return "IMA_ADPCM";
case AFMT_U8:
return "U8";
case AFMT_S16_LE:
return "S16_LE";
case AFMT_S16_BE:
return "S16_BE";
case AFMT_S8:
return "S8";
case AFMT_U16_LE:
return "U16_LE";
case AFMT_U16_BE:
return "U16_BE";
case AFMT_MPEG:
return "MPEG";
default:
return "unknown";
}
}
#endif
static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
struct snd_info_buffer *buffer)
{
struct snd_pcm_info *info;
int err;
if (! substream)
return;
info = kmalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return;
err = snd_pcm_info(substream, info);
if (err < 0) {
snd_iprintf(buffer, "error %d\n", err);
kfree(info);
return;
}
snd_iprintf(buffer, "card: %d\n", info->card);
snd_iprintf(buffer, "device: %d\n", info->device);
snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
snd_iprintf(buffer, "id: %s\n", info->id);
snd_iprintf(buffer, "name: %s\n", info->name);
snd_iprintf(buffer, "subname: %s\n", info->subname);
snd_iprintf(buffer, "class: %d\n", info->dev_class);
snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
kfree(info);
}
static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
buffer);
}
static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
snd_pcm_proc_info_read(entry->private_data, buffer);
}
static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_substream *substream = entry->private_data;
struct snd_pcm_runtime *runtime;
mutex_lock(&substream->pcm->open_mutex);
runtime = substream->runtime;
if (!runtime) {
snd_iprintf(buffer, "closed\n");
goto unlock;
}
if (runtime->state == SNDRV_PCM_STATE_OPEN) {
snd_iprintf(buffer, "no setup\n");
goto unlock;
}
snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
snd_iprintf(buffer, "channels: %u\n", runtime->channels);
snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
#if IS_ENABLED(CONFIG_SND_PCM_OSS)
if (substream->oss.oss) {
snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
}
#endif
unlock:
mutex_unlock(&substream->pcm->open_mutex);
}
static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_substream *substream = entry->private_data;
struct snd_pcm_runtime *runtime;
mutex_lock(&substream->pcm->open_mutex);
runtime = substream->runtime;
if (!runtime) {
snd_iprintf(buffer, "closed\n");
goto unlock;
}
if (runtime->state == SNDRV_PCM_STATE_OPEN) {
snd_iprintf(buffer, "no setup\n");
goto unlock;
}
snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
unlock:
mutex_unlock(&substream->pcm->open_mutex);
}
static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_substream *substream = entry->private_data;
struct snd_pcm_runtime *runtime;
struct snd_pcm_status64 status;
int err;
mutex_lock(&substream->pcm->open_mutex);
runtime = substream->runtime;
if (!runtime) {
snd_iprintf(buffer, "closed\n");
goto unlock;
}
memset(&status, 0, sizeof(status));
err = snd_pcm_status64(substream, &status);
if (err < 0) {
snd_iprintf(buffer, "error %d\n", err);
goto unlock;
}
snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
snd_iprintf(buffer, "owner_pid : %d\n", pid_vnr(substream->pid));
snd_iprintf(buffer, "trigger_time: %lld.%09lld\n",
status.trigger_tstamp_sec, status.trigger_tstamp_nsec);
snd_iprintf(buffer, "tstamp : %lld.%09lld\n",
status.tstamp_sec, status.tstamp_nsec);
snd_iprintf(buffer, "delay : %ld\n", status.delay);
snd_iprintf(buffer, "avail : %ld\n", status.avail);
snd_iprintf(buffer, "avail_max : %ld\n", status.avail_max);
snd_iprintf(buffer, "-----\n");
snd_iprintf(buffer, "hw_ptr : %ld\n", runtime->status->hw_ptr);
snd_iprintf(buffer, "appl_ptr : %ld\n", runtime->control->appl_ptr);
unlock:
mutex_unlock(&substream->pcm->open_mutex);
}
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_substream *substream = entry->private_data;
snd_pcm_stop_xrun(substream);
}
static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_str *pstr = entry->private_data;
snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
}
static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_str *pstr = entry->private_data;
char line[64];
if (!snd_info_get_line(buffer, line, sizeof(line)))
pstr->xrun_debug = simple_strtoul(line, NULL, 10);
}
#endif
static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
{
struct snd_pcm *pcm = pstr->pcm;
struct snd_info_entry *entry;
char name[16];
sprintf(name, "pcm%i%c", pcm->device,
pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
entry = snd_info_create_card_entry(pcm->card, name,
pcm->card->proc_root);
if (!entry)
return -ENOMEM;
entry->mode = S_IFDIR | 0555;
pstr->proc_root = entry;
entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
if (entry)
snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
pstr->proc_root);
if (entry) {
snd_info_set_text_ops(entry, pstr, snd_pcm_xrun_debug_read);
entry->c.text.write = snd_pcm_xrun_debug_write;
entry->mode |= 0200;
}
#endif
return 0;
}
static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
{
snd_info_free_entry(pstr->proc_root);
pstr->proc_root = NULL;
return 0;
}
static struct snd_info_entry *
create_substream_info_entry(struct snd_pcm_substream *substream,
const char *name,
void (*read)(struct snd_info_entry *,
struct snd_info_buffer *))
{
struct snd_info_entry *entry;
entry = snd_info_create_card_entry(substream->pcm->card, name,
substream->proc_root);
if (entry)
snd_info_set_text_ops(entry, substream, read);
return entry;
}
static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
{
struct snd_info_entry *entry;
struct snd_card *card;
char name[16];
card = substream->pcm->card;
sprintf(name, "sub%i", substream->number);
entry = snd_info_create_card_entry(card, name,
substream->pstr->proc_root);
if (!entry)
return -ENOMEM;
entry->mode = S_IFDIR | 0555;
substream->proc_root = entry;
create_substream_info_entry(substream, "info",
snd_pcm_substream_proc_info_read);
create_substream_info_entry(substream, "hw_params",
snd_pcm_substream_proc_hw_params_read);
create_substream_info_entry(substream, "sw_params",
snd_pcm_substream_proc_sw_params_read);
create_substream_info_entry(substream, "status",
snd_pcm_substream_proc_status_read);
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
entry = create_substream_info_entry(substream, "xrun_injection", NULL);
if (entry) {
entry->c.text.write = snd_pcm_xrun_injection_write;
entry->mode = S_IFREG | 0200;
}
#endif /* CONFIG_SND_PCM_XRUN_DEBUG */
return 0;
}
#else /* !CONFIG_SND_VERBOSE_PROCFS */
static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
#endif /* CONFIG_SND_VERBOSE_PROCFS */
static const struct attribute_group *pcm_dev_attr_groups[];
/*
* PM callbacks: we need to deal only with suspend here, as the resume is
* triggered either from user-space or the driver's resume callback
*/
#ifdef CONFIG_PM_SLEEP
static int do_pcm_suspend(struct device *dev)
{
struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
if (!pstr->pcm->no_device_suspend)
snd_pcm_suspend_all(pstr->pcm);
return 0;
}
#endif
static const struct dev_pm_ops pcm_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
};
/* device type for PCM -- basically only for passing PM callbacks */
static const struct device_type pcm_dev_type = {
.name = "pcm",
.pm = &pcm_dev_pm_ops,
};
/**
* snd_pcm_new_stream - create a new PCM stream
* @pcm: the pcm instance
* @stream: the stream direction, SNDRV_PCM_STREAM_XXX
* @substream_count: the number of substreams
*
* Creates a new stream for the pcm.
* The corresponding stream on the pcm must have been empty before
* calling this, i.e. zero must be given to the argument of
* snd_pcm_new().
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
{
int idx, err;
struct snd_pcm_str *pstr = &pcm->streams[stream];
struct snd_pcm_substream *substream, *prev;
#if IS_ENABLED(CONFIG_SND_PCM_OSS)
mutex_init(&pstr->oss.setup_mutex);
#endif
pstr->stream = stream;
pstr->pcm = pcm;
pstr->substream_count = substream_count;
if (!substream_count)
return 0;
snd_device_initialize(&pstr->dev, pcm->card);
pstr->dev.groups = pcm_dev_attr_groups;
pstr->dev.type = &pcm_dev_type;
dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
if (!pcm->internal) {
err = snd_pcm_stream_proc_init(pstr);
if (err < 0) {
pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
return err;
}
}
prev = NULL;
for (idx = 0, prev = NULL; idx < substream_count; idx++) {
substream = kzalloc(sizeof(*substream), GFP_KERNEL);
if (!substream)
return -ENOMEM;
substream->pcm = pcm;
substream->pstr = pstr;
substream->number = idx;
substream->stream = stream;
sprintf(substream->name, "subdevice #%i", idx);
substream->buffer_bytes_max = UINT_MAX;
if (prev == NULL)
pstr->substream = substream;
else
prev->next = substream;
if (!pcm->internal) {
err = snd_pcm_substream_proc_init(substream);
if (err < 0) {
pcm_err(pcm,
"Error in snd_pcm_stream_proc_init\n");
if (prev == NULL)
pstr->substream = NULL;
else
prev->next = NULL;
kfree(substream);
return err;
}
}
substream->group = &substream->self_group;
snd_pcm_group_init(&substream->self_group);
list_add_tail(&substream->link_list, &substream->self_group.substreams);
atomic_set(&substream->mmap_count, 0);
prev = substream;
}
return 0;
}
EXPORT_SYMBOL(snd_pcm_new_stream);
static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
int playback_count, int capture_count, bool internal,
struct snd_pcm **rpcm)
{
struct snd_pcm *pcm;
int err;
static const struct snd_device_ops ops = {
.dev_free = snd_pcm_dev_free,
.dev_register = snd_pcm_dev_register,
.dev_disconnect = snd_pcm_dev_disconnect,
};
static const struct snd_device_ops internal_ops = {
.dev_free = snd_pcm_dev_free,
};
if (snd_BUG_ON(!card))
return -ENXIO;
if (rpcm)
*rpcm = NULL;
pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
if (!pcm)
return -ENOMEM;
pcm->card = card;
pcm->device = device;
pcm->internal = internal;
mutex_init(&pcm->open_mutex);
init_waitqueue_head(&pcm->open_wait);
INIT_LIST_HEAD(&pcm->list);
if (id)
strscpy(pcm->id, id, sizeof(pcm->id));
err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
playback_count);
if (err < 0)
goto free_pcm;
err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
if (err < 0)
goto free_pcm;
err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
internal ? &internal_ops : &ops);
if (err < 0)
goto free_pcm;
if (rpcm)
*rpcm = pcm;
return 0;
free_pcm:
snd_pcm_free(pcm);
return err;
}
/**
* snd_pcm_new - create a new PCM instance
* @card: the card instance
* @id: the id string
* @device: the device index (zero based)
* @playback_count: the number of substreams for playback
* @capture_count: the number of substreams for capture
* @rpcm: the pointer to store the new pcm instance
*
* Creates a new PCM instance.
*
* The pcm operators have to be set afterwards to the new instance
* via snd_pcm_set_ops().
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_new(struct snd_card *card, const char *id, int device,
int playback_count, int capture_count, struct snd_pcm **rpcm)
{
return _snd_pcm_new(card, id, device, playback_count, capture_count,
false, rpcm);
}
EXPORT_SYMBOL(snd_pcm_new);
/**
* snd_pcm_new_internal - create a new internal PCM instance
* @card: the card instance
* @id: the id string
* @device: the device index (zero based - shared with normal PCMs)
* @playback_count: the number of substreams for playback
* @capture_count: the number of substreams for capture
* @rpcm: the pointer to store the new pcm instance
*
* Creates a new internal PCM instance with no userspace device or procfs
* entries. This is used by ASoC Back End PCMs in order to create a PCM that
* will only be used internally by kernel drivers. i.e. it cannot be opened
* by userspace. It provides existing ASoC components drivers with a substream
* and access to any private data.
*
* The pcm operators have to be set afterwards to the new instance
* via snd_pcm_set_ops().
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
int playback_count, int capture_count,
struct snd_pcm **rpcm)
{
return _snd_pcm_new(card, id, device, playback_count, capture_count,
true, rpcm);
}
EXPORT_SYMBOL(snd_pcm_new_internal);
static void free_chmap(struct snd_pcm_str *pstr)
{
if (pstr->chmap_kctl) {
struct snd_card *card = pstr->pcm->card;
down_write(&card->controls_rwsem);
snd_ctl_remove(card, pstr->chmap_kctl);
up_write(&card->controls_rwsem);
pstr->chmap_kctl = NULL;
}
}
static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
{
struct snd_pcm_substream *substream, *substream_next;
#if IS_ENABLED(CONFIG_SND_PCM_OSS)
struct snd_pcm_oss_setup *setup, *setupn;
#endif
/* free all proc files under the stream */
snd_pcm_stream_proc_done(pstr);
substream = pstr->substream;
while (substream) {
substream_next = substream->next;
snd_pcm_timer_done(substream);
kfree(substream);
substream = substream_next;
}
#if IS_ENABLED(CONFIG_SND_PCM_OSS)
for (setup = pstr->oss.setup_list; setup; setup = setupn) {
setupn = setup->next;
kfree(setup->task_name);
kfree(setup);
}
#endif
free_chmap(pstr);
if (pstr->substream_count)
put_device(&pstr->dev);
}
#if IS_ENABLED(CONFIG_SND_PCM_OSS)
#define pcm_call_notify(pcm, call) \
do { \
struct snd_pcm_notify *_notify; \
list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
_notify->call(pcm); \
} while (0)
#else
#define pcm_call_notify(pcm, call) do {} while (0)
#endif
static int snd_pcm_free(struct snd_pcm *pcm)
{
if (!pcm)
return 0;
if (!pcm->internal)
pcm_call_notify(pcm, n_unregister);
if (pcm->private_free)
pcm->private_free(pcm);
snd_pcm_lib_preallocate_free_for_all(pcm);
snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
kfree(pcm);
return 0;
}
static int snd_pcm_dev_free(struct snd_device *device)
{
struct snd_pcm *pcm = device->device_data;
return snd_pcm_free(pcm);
}
int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
struct file *file,
struct snd_pcm_substream **rsubstream)
{
struct snd_pcm_str * pstr;
struct snd_pcm_substream *substream;
struct snd_pcm_runtime *runtime;
struct snd_card *card;
int prefer_subdevice;
size_t size;
if (snd_BUG_ON(!pcm || !rsubstream))
return -ENXIO;
if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
stream != SNDRV_PCM_STREAM_CAPTURE))
return -EINVAL;
*rsubstream = NULL;
pstr = &pcm->streams[stream];
if (pstr->substream == NULL || pstr->substream_count == 0)
return -ENODEV;
card = pcm->card;
prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
int opposite = !stream;
for (substream = pcm->streams[opposite].substream; substream;
substream = substream->next) {
if (SUBSTREAM_BUSY(substream))
return -EAGAIN;
}
}
if (file->f_flags & O_APPEND) {
if (prefer_subdevice < 0) {
if (pstr->substream_count > 1)
return -EINVAL; /* must be unique */
substream = pstr->substream;
} else {
for (substream = pstr->substream; substream;
substream = substream->next)
if (substream->number == prefer_subdevice)
break;
}
if (! substream)
return -ENODEV;
if (! SUBSTREAM_BUSY(substream))
return -EBADFD;
substream->ref_count++;
*rsubstream = substream;
return 0;
}
for (substream = pstr->substream; substream; substream = substream->next) {
if (!SUBSTREAM_BUSY(substream) &&
(prefer_subdevice == -1 ||
substream->number == prefer_subdevice))
break;
}
if (substream == NULL)
return -EAGAIN;
runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
if (runtime == NULL)
return -ENOMEM;
size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
runtime->status = alloc_pages_exact(size, GFP_KERNEL);
if (runtime->status == NULL) {
kfree(runtime);
return -ENOMEM;
}
memset(runtime->status, 0, size);
size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
runtime->control = alloc_pages_exact(size, GFP_KERNEL);
if (runtime->control == NULL) {
free_pages_exact(runtime->status,
PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
kfree(runtime);
return -ENOMEM;
}
memset(runtime->control, 0, size);
init_waitqueue_head(&runtime->sleep);
init_waitqueue_head(&runtime->tsleep);
__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_OPEN);
mutex_init(&runtime->buffer_mutex);
atomic_set(&runtime->buffer_accessing, 0);
substream->runtime = runtime;
substream->private_data = pcm->private_data;
substream->ref_count = 1;
substream->f_flags = file->f_flags;
substream->pid = get_pid(task_pid(current));
pstr->substream_opened++;
*rsubstream = substream;
return 0;
}
void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime;
if (PCM_RUNTIME_CHECK(substream))
return;
runtime = substream->runtime;
if (runtime->private_free != NULL)
runtime->private_free(runtime);
free_pages_exact(runtime->status,
PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
free_pages_exact(runtime->control,
PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
kfree(runtime->hw_constraints.rules);
/* Avoid concurrent access to runtime via PCM timer interface */
if (substream->timer) {
spin_lock_irq(&substream->timer->lock);
substream->runtime = NULL;
spin_unlock_irq(&substream->timer->lock);
} else {
substream->runtime = NULL;
}
mutex_destroy(&runtime->buffer_mutex);
snd_fasync_free(runtime->fasync);
kfree(runtime);
put_pid(substream->pid);
substream->pid = NULL;
substream->pstr->substream_opened--;
}
static ssize_t pcm_class_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
struct snd_pcm *pcm = pstr->pcm;
const char *str;
static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
[SNDRV_PCM_CLASS_GENERIC] = "generic",
[SNDRV_PCM_CLASS_MULTI] = "multi",
[SNDRV_PCM_CLASS_MODEM] = "modem",
[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
};
if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
str = "none";
else
str = strs[pcm->dev_class];
return sysfs_emit(buf, "%s\n", str);
}
static DEVICE_ATTR_RO(pcm_class);
static struct attribute *pcm_dev_attrs[] = {
&dev_attr_pcm_class.attr,
NULL
};
static const struct attribute_group pcm_dev_attr_group = {
.attrs = pcm_dev_attrs,
};
static const struct attribute_group *pcm_dev_attr_groups[] = {
&pcm_dev_attr_group,
NULL
};
static int snd_pcm_dev_register(struct snd_device *device)
{
int cidx, err;
struct snd_pcm_substream *substream;
struct snd_pcm *pcm;
if (snd_BUG_ON(!device || !device->device_data))
return -ENXIO;
pcm = device->device_data;
mutex_lock(&register_mutex);
err = snd_pcm_add(pcm);
if (err)
goto unlock;
for (cidx = 0; cidx < 2; cidx++) {
int devtype = -1;
if (pcm->streams[cidx].substream == NULL)
continue;
switch (cidx) {
case SNDRV_PCM_STREAM_PLAYBACK:
devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
break;
case SNDRV_PCM_STREAM_CAPTURE:
devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
break;
}
/* register pcm */
err = snd_register_device(devtype, pcm->card, pcm->device,
&snd_pcm_f_ops[cidx], pcm,
&pcm->streams[cidx].dev);
if (err < 0) {
list_del_init(&pcm->list);
goto unlock;
}
for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
snd_pcm_timer_init(substream);
}
pcm_call_notify(pcm, n_register);
unlock:
mutex_unlock(&register_mutex);
return err;
}
static int snd_pcm_dev_disconnect(struct snd_device *device)
{
struct snd_pcm *pcm = device->device_data;
struct snd_pcm_substream *substream;
int cidx;
mutex_lock(&register_mutex);
mutex_lock(&pcm->open_mutex);
wake_up(&pcm->open_wait);
list_del_init(&pcm->list);
for_each_pcm_substream(pcm, cidx, substream) {
snd_pcm_stream_lock_irq(substream);
if (substream->runtime) {
if (snd_pcm_running(substream))
snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
/* to be sure, set the state unconditionally */
__snd_pcm_set_state(substream->runtime,
SNDRV_PCM_STATE_DISCONNECTED);
wake_up(&substream->runtime->sleep);
wake_up(&substream->runtime->tsleep);
}
snd_pcm_stream_unlock_irq(substream);
}
for_each_pcm_substream(pcm, cidx, substream)
snd_pcm_sync_stop(substream, false);
pcm_call_notify(pcm, n_disconnect);
for (cidx = 0; cidx < 2; cidx++) {
snd_unregister_device(&pcm->streams[cidx].dev);
free_chmap(&pcm->streams[cidx]);
}
mutex_unlock(&pcm->open_mutex);
mutex_unlock(&register_mutex);
return 0;
}
#if IS_ENABLED(CONFIG_SND_PCM_OSS)
/**
* snd_pcm_notify - Add/remove the notify list
* @notify: PCM notify list
* @nfree: 0 = register, 1 = unregister
*
* This adds the given notifier to the global list so that the callback is
* called for each registered PCM devices. This exists only for PCM OSS
* emulation, so far.
*
* Return: zero if successful, or a negative error code
*/
int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
{
struct snd_pcm *pcm;
if (snd_BUG_ON(!notify ||
!notify->n_register ||
!notify->n_unregister ||
!notify->n_disconnect))
return -EINVAL;
mutex_lock(&register_mutex);
if (nfree) {
list_del(&notify->list);
list_for_each_entry(pcm, &snd_pcm_devices, list)
notify->n_unregister(pcm);
} else {
list_add_tail(&notify->list, &snd_pcm_notify_list);
list_for_each_entry(pcm, &snd_pcm_devices, list)
notify->n_register(pcm);
}
mutex_unlock(&register_mutex);
return 0;
}
EXPORT_SYMBOL(snd_pcm_notify);
#endif /* CONFIG_SND_PCM_OSS */
#ifdef CONFIG_SND_PROC_FS
/*
* Info interface
*/
static void snd_pcm_proc_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm *pcm;
mutex_lock(&register_mutex);
list_for_each_entry(pcm, &snd_pcm_devices, list) {
snd_iprintf(buffer, "%02i-%02i: %s : %s",
pcm->card->number, pcm->device, pcm->id, pcm->name);
if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
snd_iprintf(buffer, " : playback %i",
pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
snd_iprintf(buffer, " : capture %i",
pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
snd_iprintf(buffer, "\n");
}
mutex_unlock(&register_mutex);
}
static struct snd_info_entry *snd_pcm_proc_entry;
static void snd_pcm_proc_init(void)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
if (entry) {
snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
}
snd_pcm_proc_entry = entry;
}
static void snd_pcm_proc_done(void)
{
snd_info_free_entry(snd_pcm_proc_entry);
}
#else /* !CONFIG_SND_PROC_FS */
#define snd_pcm_proc_init()
#define snd_pcm_proc_done()
#endif /* CONFIG_SND_PROC_FS */
/*
* ENTRY functions
*/
static int __init alsa_pcm_init(void)
{
snd_ctl_register_ioctl(snd_pcm_control_ioctl);
snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
snd_pcm_proc_init();
return 0;
}
static void __exit alsa_pcm_exit(void)
{
snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
snd_pcm_proc_done();
}
module_init(alsa_pcm_init)
module_exit(alsa_pcm_exit)