// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Timers abstract layer
* Copyright (c) by Jaroslav Kysela <[email protected]>
*/
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/sched/signal.h>
#include <linux/anon_inodes.h>
#include <linux/idr.h>
#include <sound/core.h>
#include <sound/timer.h>
#include <sound/control.h>
#include <sound/info.h>
#include <sound/minors.h>
#include <sound/initval.h>
#include <linux/kmod.h>
/* internal flags */
#define SNDRV_TIMER_IFLG_PAUSED 0x00010000
#define SNDRV_TIMER_IFLG_DEAD 0x00020000
#if IS_ENABLED(CONFIG_SND_HRTIMER)
#define DEFAULT_TIMER_LIMIT 4
#else
#define DEFAULT_TIMER_LIMIT 1
#endif
static int timer_limit = DEFAULT_TIMER_LIMIT;
static int timer_tstamp_monotonic = 1;
MODULE_AUTHOR("Jaroslav Kysela <[email protected]>, Takashi Iwai <[email protected]>");
MODULE_DESCRIPTION("ALSA timer interface");
MODULE_LICENSE("GPL");
module_param(timer_limit, int, 0444);
MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
module_param(timer_tstamp_monotonic, int, 0444);
MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
MODULE_ALIAS("devname:snd/timer");
enum timer_tread_format {
TREAD_FORMAT_NONE = 0,
TREAD_FORMAT_TIME64,
TREAD_FORMAT_TIME32,
};
struct snd_timer_tread32 {
int event;
s32 tstamp_sec;
s32 tstamp_nsec;
unsigned int val;
};
struct snd_timer_tread64 {
int event;
u8 pad1[4];
s64 tstamp_sec;
s64 tstamp_nsec;
unsigned int val;
u8 pad2[4];
};
struct snd_timer_user {
struct snd_timer_instance *timeri;
int tread; /* enhanced read with timestamps and events */
unsigned long ticks;
unsigned long overrun;
int qhead;
int qtail;
int qused;
int queue_size;
bool disconnected;
struct snd_timer_read *queue;
struct snd_timer_tread64 *tqueue;
spinlock_t qlock;
unsigned long last_resolution;
unsigned int filter;
struct timespec64 tstamp; /* trigger tstamp */
wait_queue_head_t qchange_sleep;
struct snd_fasync *fasync;
struct mutex ioctl_lock;
};
struct snd_timer_status32 {
s32 tstamp_sec; /* Timestamp - last update */
s32 tstamp_nsec;
unsigned int resolution; /* current period resolution in ns */
unsigned int lost; /* counter of master tick lost */
unsigned int overrun; /* count of read queue overruns */
unsigned int queue; /* used queue size */
unsigned char reserved[64]; /* reserved */
};
#define SNDRV_TIMER_IOCTL_STATUS32 _IOR('T', 0x14, struct snd_timer_status32)
struct snd_timer_status64 {
s64 tstamp_sec; /* Timestamp - last update */
s64 tstamp_nsec;
unsigned int resolution; /* current period resolution in ns */
unsigned int lost; /* counter of master tick lost */
unsigned int overrun; /* count of read queue overruns */
unsigned int queue; /* used queue size */
unsigned char reserved[64]; /* reserved */
};
#ifdef CONFIG_SND_UTIMER
#define SNDRV_UTIMERS_MAX_COUNT 128
/* Internal data structure for keeping the state of the userspace-driven timer */
struct snd_utimer {
char *name;
struct snd_timer *timer;
unsigned int id;
};
#endif
#define SNDRV_TIMER_IOCTL_STATUS64 _IOR('T', 0x14, struct snd_timer_status64)
/* list of timers */
static LIST_HEAD(snd_timer_list);
/* list of slave instances */
static LIST_HEAD(snd_timer_slave_list);
/* lock for slave active lists */
static DEFINE_SPINLOCK(slave_active_lock);
#define MAX_SLAVE_INSTANCES 1000
static int num_slaves;
static DEFINE_MUTEX(register_mutex);
static int snd_timer_free(struct snd_timer *timer);
static int snd_timer_dev_free(struct snd_device *device);
static int snd_timer_dev_register(struct snd_device *device);
static int snd_timer_dev_disconnect(struct snd_device *device);
static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
/*
* create a timer instance with the given owner string.
*/
struct snd_timer_instance *snd_timer_instance_new(const char *owner)
{
struct snd_timer_instance *timeri;
timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
if (timeri == NULL)
return NULL;
timeri->owner = kstrdup(owner, GFP_KERNEL);
if (! timeri->owner) {
kfree(timeri);
return NULL;
}
INIT_LIST_HEAD(&timeri->open_list);
INIT_LIST_HEAD(&timeri->active_list);
INIT_LIST_HEAD(&timeri->ack_list);
INIT_LIST_HEAD(&timeri->slave_list_head);
INIT_LIST_HEAD(&timeri->slave_active_head);
return timeri;
}
EXPORT_SYMBOL(snd_timer_instance_new);
void snd_timer_instance_free(struct snd_timer_instance *timeri)
{
if (timeri) {
if (timeri->private_free)
timeri->private_free(timeri);
kfree(timeri->owner);
kfree(timeri);
}
}
EXPORT_SYMBOL(snd_timer_instance_free);
/*
* find a timer instance from the given timer id
*/
static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
{
struct snd_timer *timer;
list_for_each_entry(timer, &snd_timer_list, device_list) {
if (timer->tmr_class != tid->dev_class)
continue;
if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
(timer->card == NULL ||
timer->card->number != tid->card))
continue;
if (timer->tmr_device != tid->device)
continue;
if (timer->tmr_subdevice != tid->subdevice)
continue;
return timer;
}
return NULL;
}
#ifdef CONFIG_MODULES
static void snd_timer_request(struct snd_timer_id *tid)
{
switch (tid->dev_class) {
case SNDRV_TIMER_CLASS_GLOBAL:
if (tid->device < timer_limit)
request_module("snd-timer-%i", tid->device);
break;
case SNDRV_TIMER_CLASS_CARD:
case SNDRV_TIMER_CLASS_PCM:
if (tid->card < snd_ecards_limit)
request_module("snd-card-%i", tid->card);
break;
default:
break;
}
}
#endif
/* move the slave if it belongs to the master; return 1 if match */
static int check_matching_master_slave(struct snd_timer_instance *master,
struct snd_timer_instance *slave)
{
if (slave->slave_class != master->slave_class ||
slave->slave_id != master->slave_id)
return 0;
if (master->timer->num_instances >= master->timer->max_instances)
return -EBUSY;
list_move_tail(&slave->open_list, &master->slave_list_head);
master->timer->num_instances++;
guard(spinlock_irq)(&slave_active_lock);
guard(spinlock)(&master->timer->lock);
slave->master = master;
slave->timer = master->timer;
if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
list_add_tail(&slave->active_list, &master->slave_active_head);
return 1;
}
/*
* look for a master instance matching with the slave id of the given slave.
* when found, relink the open_link of the slave.
*
* call this with register_mutex down.
*/
static int snd_timer_check_slave(struct snd_timer_instance *slave)
{
struct snd_timer *timer;
struct snd_timer_instance *master;
int err = 0;
/* FIXME: it's really dumb to look up all entries.. */
list_for_each_entry(timer, &snd_timer_list, device_list) {
list_for_each_entry(master, &timer->open_list_head, open_list) {
err = check_matching_master_slave(master, slave);
if (err != 0) /* match found or error */
goto out;
}
}
out:
return err < 0 ? err : 0;
}
/*
* look for slave instances matching with the slave id of the given master.
* when found, relink the open_link of slaves.
*
* call this with register_mutex down.
*/
static int snd_timer_check_master(struct snd_timer_instance *master)
{
struct snd_timer_instance *slave, *tmp;
int err = 0;
/* check all pending slaves */
list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
err = check_matching_master_slave(master, slave);
if (err < 0)
break;
}
return err < 0 ? err : 0;
}
static void snd_timer_close_locked(struct snd_timer_instance *timeri,
struct device **card_devp_to_put);
/*
* open a timer instance
* when opening a master, the slave id must be here given.
*/
int snd_timer_open(struct snd_timer_instance *timeri,
struct snd_timer_id *tid,
unsigned int slave_id)
{
struct snd_timer *timer;
struct device *card_dev_to_put = NULL;
int err;
mutex_lock(®ister_mutex);
if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
/* open a slave instance */
if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
pr_debug("ALSA: timer: invalid slave class %i\n",
tid->dev_sclass);
err = -EINVAL;
goto unlock;
}
if (num_slaves >= MAX_SLAVE_INSTANCES) {
err = -EBUSY;
goto unlock;
}
timeri->slave_class = tid->dev_sclass;
timeri->slave_id = tid->device;
timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
list_add_tail(&timeri->open_list, &snd_timer_slave_list);
num_slaves++;
err = snd_timer_check_slave(timeri);
goto list_added;
}
/* open a master instance */
timer = snd_timer_find(tid);
#ifdef CONFIG_MODULES
if (!timer) {
mutex_unlock(®ister_mutex);
snd_timer_request(tid);
mutex_lock(®ister_mutex);
timer = snd_timer_find(tid);
}
#endif
if (!timer) {
err = -ENODEV;
goto unlock;
}
if (!list_empty(&timer->open_list_head)) {
struct snd_timer_instance *t =
list_entry(timer->open_list_head.next,
struct snd_timer_instance, open_list);
if (t->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
err = -EBUSY;
goto unlock;
}
}
if (timer->num_instances >= timer->max_instances) {
err = -EBUSY;
goto unlock;
}
if (!try_module_get(timer->module)) {
err = -EBUSY;
goto unlock;
}
/* take a card refcount for safe disconnection */
if (timer->card) {
get_device(&timer->card->card_dev);
card_dev_to_put = &timer->card->card_dev;
}
if (list_empty(&timer->open_list_head) && timer->hw.open) {
err = timer->hw.open(timer);
if (err) {
module_put(timer->module);
goto unlock;
}
}
timeri->timer = timer;
timeri->slave_class = tid->dev_sclass;
timeri->slave_id = slave_id;
list_add_tail(&timeri->open_list, &timer->open_list_head);
timer->num_instances++;
err = snd_timer_check_master(timeri);
list_added:
if (err < 0)
snd_timer_close_locked(timeri, &card_dev_to_put);
unlock:
mutex_unlock(®ister_mutex);
/* put_device() is called after unlock for avoiding deadlock */
if (err < 0 && card_dev_to_put)
put_device(card_dev_to_put);
return err;
}
EXPORT_SYMBOL(snd_timer_open);
/* remove slave links, called from snd_timer_close_locked() below */
static void remove_slave_links(struct snd_timer_instance *timeri,
struct snd_timer *timer)
{
struct snd_timer_instance *slave, *tmp;
guard(spinlock_irq)(&slave_active_lock);
guard(spinlock)(&timer->lock);
timeri->timer = NULL;
list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head, open_list) {
list_move_tail(&slave->open_list, &snd_timer_slave_list);
timer->num_instances--;
slave->master = NULL;
slave->timer = NULL;
list_del_init(&slave->ack_list);
list_del_init(&slave->active_list);
}
}
/*
* close a timer instance
* call this with register_mutex down.
*/
static void snd_timer_close_locked(struct snd_timer_instance *timeri,
struct device **card_devp_to_put)
{
struct snd_timer *timer = timeri->timer;
if (timer) {
guard(spinlock_irq)(&timer->lock);
timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
}
if (!list_empty(&timeri->open_list)) {
list_del_init(&timeri->open_list);
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
num_slaves--;
}
/* force to stop the timer */
snd_timer_stop(timeri);
if (timer) {
timer->num_instances--;
/* wait, until the active callback is finished */
spin_lock_irq(&timer->lock);
while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
spin_unlock_irq(&timer->lock);
udelay(10);
spin_lock_irq(&timer->lock);
}
spin_unlock_irq(&timer->lock);
remove_slave_links(timeri, timer);
/* slave doesn't need to release timer resources below */
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
timer = NULL;
}
if (timer) {
if (list_empty(&timer->open_list_head) && timer->hw.close)
timer->hw.close(timer);
/* release a card refcount for safe disconnection */
if (timer->card)
*card_devp_to_put = &timer->card->card_dev;
module_put(timer->module);
}
}
/*
* close a timer instance
*/
void snd_timer_close(struct snd_timer_instance *timeri)
{
struct device *card_dev_to_put = NULL;
if (snd_BUG_ON(!timeri))
return;
scoped_guard(mutex, ®ister_mutex)
snd_timer_close_locked(timeri, &card_dev_to_put);
/* put_device() is called after unlock for avoiding deadlock */
if (card_dev_to_put)
put_device(card_dev_to_put);
}
EXPORT_SYMBOL(snd_timer_close);
static unsigned long snd_timer_hw_resolution(struct snd_timer *timer)
{
if (timer->hw.c_resolution)
return timer->hw.c_resolution(timer);
else
return timer->hw.resolution;
}
unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
{
struct snd_timer * timer;
unsigned long ret = 0;
if (timeri == NULL)
return 0;
timer = timeri->timer;
if (timer) {
guard(spinlock_irqsave)(&timer->lock);
ret = snd_timer_hw_resolution(timer);
}
return ret;
}
EXPORT_SYMBOL(snd_timer_resolution);
static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
{
struct snd_timer *timer = ti->timer;
unsigned long resolution = 0;
struct snd_timer_instance *ts;
struct timespec64 tstamp;
if (timer_tstamp_monotonic)
ktime_get_ts64(&tstamp);
else
ktime_get_real_ts64(&tstamp);
if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
event > SNDRV_TIMER_EVENT_PAUSE))
return;
if (timer &&
(event == SNDRV_TIMER_EVENT_START ||
event == SNDRV_TIMER_EVENT_CONTINUE))
resolution = snd_timer_hw_resolution(timer);
if (ti->ccallback)
ti->ccallback(ti, event, &tstamp, resolution);
if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
return;
if (timer == NULL)
return;
if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
return;
event += 10; /* convert to SNDRV_TIMER_EVENT_MXXX */
list_for_each_entry(ts, &ti->slave_active_head, active_list)
if (ts->ccallback)
ts->ccallback(ts, event, &tstamp, resolution);
}
/* start/continue a master timer */
static int snd_timer_start1(struct snd_timer_instance *timeri,
bool start, unsigned long ticks)
{
struct snd_timer *timer;
int result;
timer = timeri->timer;
if (!timer)
return -EINVAL;
guard(spinlock_irqsave)(&timer->lock);
if (timeri->flags & SNDRV_TIMER_IFLG_DEAD)
return -EINVAL;
if (timer->card && timer->card->shutdown)
return -ENODEV;
if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
SNDRV_TIMER_IFLG_START))
return -EBUSY;
/* check the actual time for the start tick;
* bail out as error if it's way too low (< 100us)
*/
if (start && !(timer->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
if ((u64)snd_timer_hw_resolution(timer) * ticks < 100000)
return -EINVAL;
}
if (start)
timeri->ticks = timeri->cticks = ticks;
else if (!timeri->cticks)
timeri->cticks = 1;
timeri->pticks = 0;
list_move_tail(&timeri->active_list, &timer->active_list_head);
if (timer->running) {
if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
goto __start_now;
timer->flags |= SNDRV_TIMER_FLG_RESCHED;
timeri->flags |= SNDRV_TIMER_IFLG_START;
result = 1; /* delayed start */
} else {
if (start)
timer->sticks = ticks;
timer->hw.start(timer);
__start_now:
timer->running++;
timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
result = 0;
}
snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
SNDRV_TIMER_EVENT_CONTINUE);
return result;
}
/* start/continue a slave timer */
static int snd_timer_start_slave(struct snd_timer_instance *timeri,
bool start)
{
guard(spinlock_irqsave)(&slave_active_lock);
if (timeri->flags & SNDRV_TIMER_IFLG_DEAD)
return -EINVAL;
if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING)
return -EBUSY;
timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
if (timeri->master && timeri->timer) {
guard(spinlock)(&timeri->timer->lock);
list_add_tail(&timeri->active_list,
&timeri->master->slave_active_head);
snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
SNDRV_TIMER_EVENT_CONTINUE);
}
return 1; /* delayed start */
}
/* stop/pause a master timer */
static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
{
struct snd_timer *timer;
timer = timeri->timer;
if (!timer)
return -EINVAL;
guard(spinlock_irqsave)(&timer->lock);
list_del_init(&timeri->ack_list);
list_del_init(&timeri->active_list);
if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
SNDRV_TIMER_IFLG_START)))
return -EBUSY;
if (timer->card && timer->card->shutdown)
return 0;
if (stop) {
timeri->cticks = timeri->ticks;
timeri->pticks = 0;
}
if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
!(--timer->running)) {
timer->hw.stop(timer);
if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
snd_timer_reschedule(timer, 0);
if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
timer->hw.start(timer);
}
}
}
timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
if (stop)
timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
else
timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
SNDRV_TIMER_EVENT_PAUSE);
return 0;
}
/* stop/pause a slave timer */
static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
{
bool running;
guard(spinlock_irqsave)(&slave_active_lock);
running = timeri->flags & SNDRV_TIMER_IFLG_RUNNING;
timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
if (timeri->timer) {
guard(spinlock)(&timeri->timer->lock);
list_del_init(&timeri->ack_list);
list_del_init(&timeri->active_list);
if (running)
snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
SNDRV_TIMER_EVENT_PAUSE);
}
return running ? 0 : -EBUSY;
}
/*
* start the timer instance
*/
int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
{
if (timeri == NULL || ticks < 1)
return -EINVAL;
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
return snd_timer_start_slave(timeri, true);
else
return snd_timer_start1(timeri, true, ticks);
}
EXPORT_SYMBOL(snd_timer_start);
/*
* stop the timer instance.
*
* do not call this from the timer callback!
*/
int snd_timer_stop(struct snd_timer_instance *timeri)
{
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
return snd_timer_stop_slave(timeri, true);
else
return snd_timer_stop1(timeri, true);
}
EXPORT_SYMBOL(snd_timer_stop);
/*
* start again.. the tick is kept.
*/
int snd_timer_continue(struct snd_timer_instance *timeri)
{
/* timer can continue only after pause */
if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
return -EINVAL;
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
return snd_timer_start_slave(timeri, false);
else
return snd_timer_start1(timeri, false, 0);
}
EXPORT_SYMBOL(snd_timer_continue);
/*
* pause.. remember the ticks left
*/
int snd_timer_pause(struct snd_timer_instance * timeri)
{
if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
return snd_timer_stop_slave(timeri, false);
else
return snd_timer_stop1(timeri, false);
}
EXPORT_SYMBOL(snd_timer_pause);
/*
* reschedule the timer
*
* start pending instances and check the scheduling ticks.
* when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
*/
static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
{
struct snd_timer_instance *ti;
unsigned long ticks = ~0UL;
list_for_each_entry(ti, &timer->active_list_head, active_list) {
if (ti->flags & SNDRV_TIMER_IFLG_START) {
ti->flags &= ~SNDRV_TIMER_IFLG_START;
ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
timer->running++;
}
if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
if (ticks > ti->cticks)
ticks = ti->cticks;
}
}
if (ticks == ~0UL) {
timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
return;
}
if (ticks > timer->hw.ticks)
ticks = timer->hw.ticks;
if (ticks_left != ticks)
timer->flags |= SNDRV_TIMER_FLG_CHANGE;
timer->sticks = ticks;
}
/* call callbacks in timer ack list */
static void snd_timer_process_callbacks(struct snd_timer *timer,
struct list_head *head)
{
struct snd_timer_instance *ti;
unsigned long resolution, ticks;
while (!list_empty(head)) {
ti = list_first_entry(head, struct snd_timer_instance,
ack_list);
/* remove from ack_list and make empty */
list_del_init(&ti->ack_list);
if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
ticks = ti->pticks;
ti->pticks = 0;
resolution = ti->resolution;
ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
spin_unlock(&timer->lock);
if (ti->callback)
ti->callback(ti, resolution, ticks);
spin_lock(&timer->lock);
ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
}
}
}
/* clear pending instances from ack list */
static void snd_timer_clear_callbacks(struct snd_timer *timer,
struct list_head *head)
{
guard(spinlock_irqsave)(&timer->lock);
while (!list_empty(head))
list_del_init(head->next);
}
/*
* timer work
*
*/
static void snd_timer_work(struct work_struct *work)
{
struct snd_timer *timer = container_of(work, struct snd_timer, task_work);
if (timer->card && timer->card->shutdown) {
snd_timer_clear_callbacks(timer, &timer->sack_list_head);
return;
}
guard(spinlock_irqsave)(&timer->lock);
snd_timer_process_callbacks(timer, &timer->sack_list_head);
}
/*
* timer interrupt
*
* ticks_left is usually equal to timer->sticks.
*
*/
void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
{
struct snd_timer_instance *ti, *ts, *tmp;
unsigned long resolution;
struct list_head *ack_list_head;
if (timer == NULL)
return;
if (timer->card && timer->card->shutdown) {
snd_timer_clear_callbacks(timer, &timer->ack_list_head);
return;
}
guard(spinlock_irqsave)(&timer->lock);
/* remember the current resolution */
resolution = snd_timer_hw_resolution(timer);
/* loop for all active instances
* Here we cannot use list_for_each_entry because the active_list of a
* processed instance is relinked to done_list_head before the callback
* is called.
*/
list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
active_list) {
if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
continue;
if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
continue;
ti->pticks += ticks_left;
ti->resolution = resolution;
if (ti->cticks < ticks_left)
ti->cticks = 0;
else
ti->cticks -= ticks_left;
if (ti->cticks) /* not expired */
continue;
if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
ti->cticks = ti->ticks;
} else {
ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
--timer->running;
list_del_init(&ti->active_list);
}
if ((timer->hw.flags & SNDRV_TIMER_HW_WORK) ||
(ti->flags & SNDRV_TIMER_IFLG_FAST))
ack_list_head = &timer->ack_list_head;
else
ack_list_head = &timer->sack_list_head;
if (list_empty(&ti->ack_list))
list_add_tail(&ti->ack_list, ack_list_head);
list_for_each_entry(ts, &ti->slave_active_head, active_list) {
ts->pticks = ti->pticks;
ts->resolution = resolution;
if (list_empty(&ts->ack_list))
list_add_tail(&ts->ack_list, ack_list_head);
}
}
if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
snd_timer_reschedule(timer, timer->sticks);
if (timer->running) {
if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
timer->hw.stop(timer);
timer->flags |= SNDRV_TIMER_FLG_CHANGE;
}
if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
(timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
/* restart timer */
timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
timer->hw.start(timer);
}
} else {
timer->hw.stop(timer);
}
/* now process all fast callbacks */
snd_timer_process_callbacks(timer, &timer->ack_list_head);
/* do we have any slow callbacks? */
if (!list_empty(&timer->sack_list_head))
queue_work(system_highpri_wq, &timer->task_work);
}
EXPORT_SYMBOL(snd_timer_interrupt);
/*
*/
int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
struct snd_timer **rtimer)
{
struct snd_timer *timer;
int err;
static const struct snd_device_ops ops = {
.dev_free = snd_timer_dev_free,
.dev_register = snd_timer_dev_register,
.dev_disconnect = snd_timer_dev_disconnect,
};
if (snd_BUG_ON(!tid))
return -EINVAL;
if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
if (WARN_ON(!card))
return -EINVAL;
}
if (rtimer)
*rtimer = NULL;
timer = kzalloc(sizeof(*timer), GFP_KERNEL);
if (!timer)
return -ENOMEM;
timer->tmr_class = tid->dev_class;
timer->card = card;
timer->tmr_device = tid->device;
timer->tmr_subdevice = tid->subdevice;
if (id)
strscpy(timer->id, id, sizeof(timer->id));
timer->sticks = 1;
INIT_LIST_HEAD(&timer->device_list);
INIT_LIST_HEAD(&timer->open_list_head);
INIT_LIST_HEAD(&timer->active_list_head);
INIT_LIST_HEAD(&timer->ack_list_head);
INIT_LIST_HEAD(&timer->sack_list_head);
spin_lock_init(&timer->lock);
INIT_WORK(&timer->task_work, snd_timer_work);
timer->max_instances = 1000; /* default limit per timer */
if (card != NULL) {
timer->module = card->module;
err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
if (err < 0) {
snd_timer_free(timer);
return err;
}
}
if (rtimer)
*rtimer = timer;
return 0;
}
EXPORT_SYMBOL(snd_timer_new);
static int snd_timer_free(struct snd_timer *timer)
{
if (!timer)
return 0;
guard(mutex)(®ister_mutex);
if (! list_empty(&timer->open_list_head)) {
struct list_head *p, *n;
struct snd_timer_instance *ti;
pr_warn("ALSA: timer %p is busy?\n", timer);
list_for_each_safe(p, n, &timer->open_list_head) {
list_del_init(p);
ti = list_entry(p, struct snd_timer_instance, open_list);
ti->timer = NULL;
}
}
list_del(&timer->device_list);
if (timer->private_free)
timer->private_free(timer);
kfree(timer);
return 0;
}
static int snd_timer_dev_free(struct snd_device *device)
{
struct snd_timer *timer = device->device_data;
return snd_timer_free(timer);
}
static int snd_timer_dev_register(struct snd_device *dev)
{
struct snd_timer *timer = dev->device_data;
struct snd_timer *timer1;
if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
return -ENXIO;
if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
!timer->hw.resolution && timer->hw.c_resolution == NULL)
return -EINVAL;
guard(mutex)(®ister_mutex);
list_for_each_entry(timer1, &snd_timer_list, device_list) {
if (timer1->tmr_class > timer->tmr_class)
break;
if (timer1->tmr_class < timer->tmr_class)
continue;
if (timer1->card && timer->card) {
if (timer1->card->number > timer->card->number)
break;
if (timer1->card->number < timer->card->number)
continue;
}
if (timer1->tmr_device > timer->tmr_device)
break;
if (timer1->tmr_device < timer->tmr_device)
continue;
if (timer1->tmr_subdevice > timer->tmr_subdevice)
break;
if (timer1->tmr_subdevice < timer->tmr_subdevice)
continue;
/* conflicts.. */
return -EBUSY;
}
list_add_tail(&timer->device_list, &timer1->device_list);
return 0;
}
static int snd_timer_dev_disconnect(struct snd_device *device)
{
struct snd_timer *timer = device->device_data;
struct snd_timer_instance *ti;
guard(mutex)(®ister_mutex);
list_del_init(&timer->device_list);
/* wake up pending sleepers */
list_for_each_entry(ti, &timer->open_list_head, open_list) {
if (ti->disconnect)
ti->disconnect(ti);
}
return 0;
}
void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp)
{
unsigned long resolution = 0;
struct snd_timer_instance *ti, *ts;
if (timer->card && timer->card->shutdown)
return;
if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
return;
if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
event > SNDRV_TIMER_EVENT_MRESUME))
return;
guard(spinlock_irqsave)(&timer->lock);
if (event == SNDRV_TIMER_EVENT_MSTART ||
event == SNDRV_TIMER_EVENT_MCONTINUE ||
event == SNDRV_TIMER_EVENT_MRESUME)
resolution = snd_timer_hw_resolution(timer);
list_for_each_entry(ti, &timer->active_list_head, active_list) {
if (ti->ccallback)
ti->ccallback(ti, event, tstamp, resolution);
list_for_each_entry(ts, &ti->slave_active_head, active_list)
if (ts->ccallback)
ts->ccallback(ts, event, tstamp, resolution);
}
}
EXPORT_SYMBOL(snd_timer_notify);
/*
* exported functions for global timers
*/
int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
{
struct snd_timer_id tid;
tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
tid.card = -1;
tid.device = device;
tid.subdevice = 0;
return snd_timer_new(NULL, id, &tid, rtimer);
}
EXPORT_SYMBOL(snd_timer_global_new);
int snd_timer_global_free(struct snd_timer *timer)
{
return snd_timer_free(timer);
}
EXPORT_SYMBOL(snd_timer_global_free);
int snd_timer_global_register(struct snd_timer *timer)
{
struct snd_device dev;
memset(&dev, 0, sizeof(dev));
dev.device_data = timer;
return snd_timer_dev_register(&dev);
}
EXPORT_SYMBOL(snd_timer_global_register);
/*
* System timer
*/
struct snd_timer_system_private {
struct timer_list tlist;
struct snd_timer *snd_timer;
unsigned long last_expires;
unsigned long last_jiffies;
unsigned long correction;
};
static void snd_timer_s_function(struct timer_list *t)
{
struct snd_timer_system_private *priv = from_timer(priv, t,
tlist);
struct snd_timer *timer = priv->snd_timer;
unsigned long jiff = jiffies;
if (time_after(jiff, priv->last_expires))
priv->correction += (long)jiff - (long)priv->last_expires;
snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
}
static int snd_timer_s_start(struct snd_timer * timer)
{
struct snd_timer_system_private *priv;
unsigned long njiff;
priv = (struct snd_timer_system_private *) timer->private_data;
njiff = (priv->last_jiffies = jiffies);
if (priv->correction > timer->sticks - 1) {
priv->correction -= timer->sticks - 1;
njiff++;
} else {
njiff += timer->sticks - priv->correction;
priv->correction = 0;
}
priv->last_expires = njiff;
mod_timer(&priv->tlist, njiff);
return 0;
}
static int snd_timer_s_stop(struct snd_timer * timer)
{
struct snd_timer_system_private *priv;
unsigned long jiff;
priv = (struct snd_timer_system_private *) timer->private_data;
del_timer(&priv->tlist);
jiff = jiffies;
if (time_before(jiff, priv->last_expires))
timer->sticks = priv->last_expires - jiff;
else
timer->sticks = 1;
priv->correction = 0;
return 0;
}
static int snd_timer_s_close(struct snd_timer *timer)
{
struct snd_timer_system_private *priv;
priv = (struct snd_timer_system_private *)timer->private_data;
del_timer_sync(&priv->tlist);
return 0;
}
static const struct snd_timer_hardware snd_timer_system =
{
.flags = SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_WORK,
.resolution = NSEC_PER_SEC / HZ,
.ticks = 10000000L,
.close = snd_timer_s_close,
.start = snd_timer_s_start,
.stop = snd_timer_s_stop
};
static void snd_timer_free_system(struct snd_timer *timer)
{
kfree(timer->private_data);
}
static int snd_timer_register_system(void)
{
struct snd_timer *timer;
struct snd_timer_system_private *priv;
int err;
err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
if (err < 0)
return err;
strcpy(timer->name, "system timer");
timer->hw = snd_timer_system;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (priv == NULL) {
snd_timer_free(timer);
return -ENOMEM;
}
priv->snd_timer = timer;
timer_setup(&priv->tlist, snd_timer_s_function, 0);
timer->private_data = priv;
timer->private_free = snd_timer_free_system;
return snd_timer_global_register(timer);
}
#ifdef CONFIG_SND_PROC_FS
/*
* Info interface
*/
static void snd_timer_proc_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_timer *timer;
struct snd_timer_instance *ti;
unsigned long resolution;
guard(mutex)(®ister_mutex);
list_for_each_entry(timer, &snd_timer_list, device_list) {
if (timer->card && timer->card->shutdown)
continue;
switch (timer->tmr_class) {
case SNDRV_TIMER_CLASS_GLOBAL:
snd_iprintf(buffer, "G%i: ", timer->tmr_device);
break;
case SNDRV_TIMER_CLASS_CARD:
snd_iprintf(buffer, "C%i-%i: ",
timer->card->number, timer->tmr_device);
break;
case SNDRV_TIMER_CLASS_PCM:
snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
timer->tmr_device, timer->tmr_subdevice);
break;
default:
snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
timer->card ? timer->card->number : -1,
timer->tmr_device, timer->tmr_subdevice);
}
snd_iprintf(buffer, "%s :", timer->name);
scoped_guard(spinlock_irq, &timer->lock)
resolution = snd_timer_hw_resolution(timer);
if (resolution)
snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
resolution / 1000,
resolution % 1000,
timer->hw.ticks);
if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
snd_iprintf(buffer, " SLAVE");
snd_iprintf(buffer, "\n");
list_for_each_entry(ti, &timer->open_list_head, open_list)
snd_iprintf(buffer, " Client %s : %s\n",
ti->owner ? ti->owner : "unknown",
(ti->flags & (SNDRV_TIMER_IFLG_START |
SNDRV_TIMER_IFLG_RUNNING))
? "running" : "stopped");
}
}
static struct snd_info_entry *snd_timer_proc_entry;
static void __init snd_timer_proc_init(void)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
if (entry != NULL) {
entry->c.text.read = snd_timer_proc_read;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
}
snd_timer_proc_entry = entry;
}
static void __exit snd_timer_proc_done(void)
{
snd_info_free_entry(snd_timer_proc_entry);
}
#else /* !CONFIG_SND_PROC_FS */
#define snd_timer_proc_init()
#define snd_timer_proc_done()
#endif
/*
* USER SPACE interface
*/
static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
unsigned long resolution,
unsigned long ticks)
{
struct snd_timer_user *tu = timeri->callback_data;
struct snd_timer_read *r;
int prev;
guard(spinlock)(&tu->qlock);
if (tu->qused > 0) {
prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
r = &tu->queue[prev];
if (r->resolution == resolution) {
r->ticks += ticks;
goto __wake;
}
}
if (tu->qused >= tu->queue_size) {
tu->overrun++;
} else {
r = &tu->queue[tu->qtail++];
tu->qtail %= tu->queue_size;
r->resolution = resolution;
r->ticks = ticks;
tu->qused++;
}
__wake:
snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
struct snd_timer_tread64 *tread)
{
if (tu->qused >= tu->queue_size) {
tu->overrun++;
} else {
memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
tu->qtail %= tu->queue_size;
tu->qused++;
}
}
static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
int event,
struct timespec64 *tstamp,
unsigned long resolution)
{
struct snd_timer_user *tu = timeri->callback_data;
struct snd_timer_tread64 r1;
if (event >= SNDRV_TIMER_EVENT_START &&
event <= SNDRV_TIMER_EVENT_PAUSE)
tu->tstamp = *tstamp;
if ((tu->filter & (1 << event)) == 0 || !tu->tread)
return;
memset(&r1, 0, sizeof(r1));
r1.event = event;
r1.tstamp_sec = tstamp->tv_sec;
r1.tstamp_nsec = tstamp->tv_nsec;
r1.val = resolution;
scoped_guard(spinlock_irqsave, &tu->qlock)
snd_timer_user_append_to_tqueue(tu, &r1);
snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
{
struct snd_timer_user *tu = timeri->callback_data;
tu->disconnected = true;
wake_up(&tu->qchange_sleep);
}
static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
unsigned long resolution,
unsigned long ticks)
{
struct snd_timer_user *tu = timeri->callback_data;
struct snd_timer_tread64 *r, r1;
struct timespec64 tstamp;
int prev, append = 0;
memset(&r1, 0, sizeof(r1));
memset(&tstamp, 0, sizeof(tstamp));
scoped_guard(spinlock, &tu->qlock) {
if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
(1 << SNDRV_TIMER_EVENT_TICK))) == 0)
return;
if (tu->last_resolution != resolution || ticks > 0) {
if (timer_tstamp_monotonic)
ktime_get_ts64(&tstamp);
else
ktime_get_real_ts64(&tstamp);
}
if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
tu->last_resolution != resolution) {
r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
r1.tstamp_sec = tstamp.tv_sec;
r1.tstamp_nsec = tstamp.tv_nsec;
r1.val = resolution;
snd_timer_user_append_to_tqueue(tu, &r1);
tu->last_resolution = resolution;
append++;
}
if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
break;
if (ticks == 0)
break;
if (tu->qused > 0) {
prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
r = &tu->tqueue[prev];
if (r->event == SNDRV_TIMER_EVENT_TICK) {
r->tstamp_sec = tstamp.tv_sec;
r->tstamp_nsec = tstamp.tv_nsec;
r->val += ticks;
append++;
break;
}
}
r1.event = SNDRV_TIMER_EVENT_TICK;
r1.tstamp_sec = tstamp.tv_sec;
r1.tstamp_nsec = tstamp.tv_nsec;
r1.val = ticks;
snd_timer_user_append_to_tqueue(tu, &r1);
append++;
}
if (append == 0)
return;
snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
static int realloc_user_queue(struct snd_timer_user *tu, int size)
{
struct snd_timer_read *queue = NULL;
struct snd_timer_tread64 *tqueue = NULL;
if (tu->tread) {
tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
if (!tqueue)
return -ENOMEM;
} else {
queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
if (!queue)
return -ENOMEM;
}
guard(spinlock_irq)(&tu->qlock);
kfree(tu->queue);
kfree(tu->tqueue);
tu->queue_size = size;
tu->queue = queue;
tu->tqueue = tqueue;
tu->qhead = tu->qtail = tu->qused = 0;
return 0;
}
static int snd_timer_user_open(struct inode *inode, struct file *file)
{
struct snd_timer_user *tu;
int err;
err = stream_open(inode, file);
if (err < 0)
return err;
tu = kzalloc(sizeof(*tu), GFP_KERNEL);
if (tu == NULL)
return -ENOMEM;
spin_lock_init(&tu->qlock);
init_waitqueue_head(&tu->qchange_sleep);
mutex_init(&tu->ioctl_lock);
tu->ticks = 1;
if (realloc_user_queue(tu, 128) < 0) {
kfree(tu);
return -ENOMEM;
}
file->private_data = tu;
return 0;
}
static int snd_timer_user_release(struct inode *inode, struct file *file)
{
struct snd_timer_user *tu;
if (file->private_data) {
tu = file->private_data;
file->private_data = NULL;
scoped_guard(mutex, &tu->ioctl_lock) {
if (tu->timeri) {
snd_timer_close(tu->timeri);
snd_timer_instance_free(tu->timeri);
}
}
snd_fasync_free(tu->fasync);
kfree(tu->queue);
kfree(tu->tqueue);
kfree(tu);
}
return 0;
}
static void snd_timer_user_zero_id(struct snd_timer_id *id)
{
id->dev_class = SNDRV_TIMER_CLASS_NONE;
id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
id->card = -1;
id->device = -1;
id->subdevice = -1;
}
static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
{
id->dev_class = timer->tmr_class;
id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
id->card = timer->card ? timer->card->number : -1;
id->device = timer->tmr_device;
id->subdevice = timer->tmr_subdevice;
}
static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
{
struct snd_timer_id id;
struct snd_timer *timer;
struct list_head *p;
if (copy_from_user(&id, _tid, sizeof(id)))
return -EFAULT;
guard(mutex)(®ister_mutex);
if (id.dev_class < 0) { /* first item */
if (list_empty(&snd_timer_list))
snd_timer_user_zero_id(&id);
else {
timer = list_entry(snd_timer_list.next,
struct snd_timer, device_list);
snd_timer_user_copy_id(&id, timer);
}
} else {
switch (id.dev_class) {
case SNDRV_TIMER_CLASS_GLOBAL:
id.device = id.device < 0 ? 0 : id.device + 1;
list_for_each(p, &snd_timer_list) {
timer = list_entry(p, struct snd_timer, device_list);
if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
snd_timer_user_copy_id(&id, timer);
break;
}
if (timer->tmr_device >= id.device) {
snd_timer_user_copy_id(&id, timer);
break;
}
}
if (p == &snd_timer_list)
snd_timer_user_zero_id(&id);
break;
case SNDRV_TIMER_CLASS_CARD:
case SNDRV_TIMER_CLASS_PCM:
if (id.card < 0) {
id.card = 0;
} else {
if (id.device < 0) {
id.device = 0;
} else {
if (id.subdevice < 0)
id.subdevice = 0;
else if (id.subdevice < INT_MAX)
id.subdevice++;
}
}
list_for_each(p, &snd_timer_list) {
timer = list_entry(p, struct snd_timer, device_list);
if (timer->tmr_class > id.dev_class) {
snd_timer_user_copy_id(&id, timer);
break;
}
if (timer->tmr_class < id.dev_class)
continue;
if (timer->card->number > id.card) {
snd_timer_user_copy_id(&id, timer);
break;
}
if (timer->card->number < id.card)
continue;
if (timer->tmr_device > id.device) {
snd_timer_user_copy_id(&id, timer);
break;
}
if (timer->tmr_device < id.device)
continue;
if (timer->tmr_subdevice > id.subdevice) {
snd_timer_user_copy_id(&id, timer);
break;
}
if (timer->tmr_subdevice < id.subdevice)
continue;
snd_timer_user_copy_id(&id, timer);
break;
}
if (p == &snd_timer_list)
snd_timer_user_zero_id(&id);
break;
default:
snd_timer_user_zero_id(&id);
}
}
if (copy_to_user(_tid, &id, sizeof(*_tid)))
return -EFAULT;
return 0;
}
static int snd_timer_user_ginfo(struct file *file,
struct snd_timer_ginfo __user *_ginfo)
{
struct snd_timer_ginfo *ginfo __free(kfree) = NULL;
struct snd_timer_id tid;
struct snd_timer *t;
struct list_head *p;
ginfo = memdup_user(_ginfo, sizeof(*ginfo));
if (IS_ERR(ginfo))
return PTR_ERR(ginfo);
tid = ginfo->tid;
memset(ginfo, 0, sizeof(*ginfo));
ginfo->tid = tid;
guard(mutex)(®ister_mutex);
t = snd_timer_find(&tid);
if (!t)
return -ENODEV;
ginfo->card = t->card ? t->card->number : -1;
if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
strscpy(ginfo->id, t->id, sizeof(ginfo->id));
strscpy(ginfo->name, t->name, sizeof(ginfo->name));
scoped_guard(spinlock_irq, &t->lock)
ginfo->resolution = snd_timer_hw_resolution(t);
if (t->hw.resolution_min > 0) {
ginfo->resolution_min = t->hw.resolution_min;
ginfo->resolution_max = t->hw.resolution_max;
}
list_for_each(p, &t->open_list_head) {
ginfo->clients++;
}
if (copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
return -EFAULT;
return 0;
}
static int timer_set_gparams(struct snd_timer_gparams *gparams)
{
struct snd_timer *t;
guard(mutex)(®ister_mutex);
t = snd_timer_find(&gparams->tid);
if (!t)
return -ENODEV;
if (!list_empty(&t->open_list_head))
return -EBUSY;
if (!t->hw.set_period)
return -ENOSYS;
return t->hw.set_period(t, gparams->period_num, gparams->period_den);
}
static int snd_timer_user_gparams(struct file *file,
struct snd_timer_gparams __user *_gparams)
{
struct snd_timer_gparams gparams;
if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
return -EFAULT;
return timer_set_gparams(&gparams);
}
static int snd_timer_user_gstatus(struct file *file,
struct snd_timer_gstatus __user *_gstatus)
{
struct snd_timer_gstatus gstatus;
struct snd_timer_id tid;
struct snd_timer *t;
int err = 0;
if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
return -EFAULT;
tid = gstatus.tid;
memset(&gstatus, 0, sizeof(gstatus));
gstatus.tid = tid;
guard(mutex)(®ister_mutex);
t = snd_timer_find(&tid);
if (t != NULL) {
guard(spinlock_irq)(&t->lock);
gstatus.resolution = snd_timer_hw_resolution(t);
if (t->hw.precise_resolution) {
t->hw.precise_resolution(t, &gstatus.resolution_num,
&gstatus.resolution_den);
} else {
gstatus.resolution_num = gstatus.resolution;
gstatus.resolution_den = 1000000000uL;
}
} else {
err = -ENODEV;
}
if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
err = -EFAULT;
return err;
}
static int snd_timer_user_tselect(struct file *file,
struct snd_timer_select __user *_tselect)
{
struct snd_timer_user *tu;
struct snd_timer_select tselect;
char str[32];
int err = 0;
tu = file->private_data;
if (tu->timeri) {
snd_timer_close(tu->timeri);
snd_timer_instance_free(tu->timeri);
tu->timeri = NULL;
}
if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
err = -EFAULT;
goto __err;
}
sprintf(str, "application %i", current->pid);
if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
tu->timeri = snd_timer_instance_new(str);
if (!tu->timeri) {
err = -ENOMEM;
goto __err;
}
tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
tu->timeri->callback = tu->tread
? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
tu->timeri->ccallback = snd_timer_user_ccallback;
tu->timeri->callback_data = (void *)tu;
tu->timeri->disconnect = snd_timer_user_disconnect;
err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
if (err < 0) {
snd_timer_instance_free(tu->timeri);
tu->timeri = NULL;
}
__err:
return err;
}
static int snd_timer_user_info(struct file *file,
struct snd_timer_info __user *_info)
{
struct snd_timer_user *tu;
struct snd_timer_info *info __free(kfree) = NULL;
struct snd_timer *t;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
t = tu->timeri->timer;
if (!t)
return -EBADFD;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (! info)
return -ENOMEM;
info->card = t->card ? t->card->number : -1;
if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
info->flags |= SNDRV_TIMER_FLG_SLAVE;
strscpy(info->id, t->id, sizeof(info->id));
strscpy(info->name, t->name, sizeof(info->name));
scoped_guard(spinlock_irq, &t->lock)
info->resolution = snd_timer_hw_resolution(t);
if (copy_to_user(_info, info, sizeof(*_info)))
return -EFAULT;
return 0;
}
static int snd_timer_user_params(struct file *file,
struct snd_timer_params __user *_params)
{
struct snd_timer_user *tu;
struct snd_timer_params params;
struct snd_timer *t;
int err;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
t = tu->timeri->timer;
if (!t)
return -EBADFD;
if (copy_from_user(¶ms, _params, sizeof(params)))
return -EFAULT;
if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
u64 resolution;
if (params.ticks < 1) {
err = -EINVAL;
goto _end;
}
/* Don't allow resolution less than 1ms */
resolution = snd_timer_resolution(tu->timeri);
resolution *= params.ticks;
if (resolution < 1000000) {
err = -EINVAL;
goto _end;
}
}
if (params.queue_size > 0 &&
(params.queue_size < 32 || params.queue_size > 1024)) {
err = -EINVAL;
goto _end;
}
if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
(1<<SNDRV_TIMER_EVENT_TICK)|
(1<<SNDRV_TIMER_EVENT_START)|
(1<<SNDRV_TIMER_EVENT_STOP)|
(1<<SNDRV_TIMER_EVENT_CONTINUE)|
(1<<SNDRV_TIMER_EVENT_PAUSE)|
(1<<SNDRV_TIMER_EVENT_SUSPEND)|
(1<<SNDRV_TIMER_EVENT_RESUME)|
(1<<SNDRV_TIMER_EVENT_MSTART)|
(1<<SNDRV_TIMER_EVENT_MSTOP)|
(1<<SNDRV_TIMER_EVENT_MCONTINUE)|
(1<<SNDRV_TIMER_EVENT_MPAUSE)|
(1<<SNDRV_TIMER_EVENT_MSUSPEND)|
(1<<SNDRV_TIMER_EVENT_MRESUME))) {
err = -EINVAL;
goto _end;
}
snd_timer_stop(tu->timeri);
scoped_guard(spinlock_irq, &t->lock) {
tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
SNDRV_TIMER_IFLG_EXCLUSIVE|
SNDRV_TIMER_IFLG_EARLY_EVENT);
if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
}
if (params.queue_size > 0 &&
(unsigned int)tu->queue_size != params.queue_size) {
err = realloc_user_queue(tu, params.queue_size);
if (err < 0)
goto _end;
}
scoped_guard(spinlock_irq, &tu->qlock) {
tu->qhead = tu->qtail = tu->qused = 0;
if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
if (tu->tread) {
struct snd_timer_tread64 tread;
memset(&tread, 0, sizeof(tread));
tread.event = SNDRV_TIMER_EVENT_EARLY;
tread.tstamp_sec = 0;
tread.tstamp_nsec = 0;
tread.val = 0;
snd_timer_user_append_to_tqueue(tu, &tread);
} else {
struct snd_timer_read *r = &tu->queue[0];
r->resolution = 0;
r->ticks = 0;
tu->qused++;
tu->qtail++;
}
}
tu->filter = params.filter;
tu->ticks = params.ticks;
}
err = 0;
_end:
if (copy_to_user(_params, ¶ms, sizeof(params)))
return -EFAULT;
return err;
}
static int snd_timer_user_status32(struct file *file,
struct snd_timer_status32 __user *_status)
{
struct snd_timer_user *tu;
struct snd_timer_status32 status;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
memset(&status, 0, sizeof(status));
status.tstamp_sec = tu->tstamp.tv_sec;
status.tstamp_nsec = tu->tstamp.tv_nsec;
status.resolution = snd_timer_resolution(tu->timeri);
status.lost = tu->timeri->lost;
status.overrun = tu->overrun;
scoped_guard(spinlock_irq, &tu->qlock)
status.queue = tu->qused;
if (copy_to_user(_status, &status, sizeof(status)))
return -EFAULT;
return 0;
}
static int snd_timer_user_status64(struct file *file,
struct snd_timer_status64 __user *_status)
{
struct snd_timer_user *tu;
struct snd_timer_status64 status;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
memset(&status, 0, sizeof(status));
status.tstamp_sec = tu->tstamp.tv_sec;
status.tstamp_nsec = tu->tstamp.tv_nsec;
status.resolution = snd_timer_resolution(tu->timeri);
status.lost = tu->timeri->lost;
status.overrun = tu->overrun;
scoped_guard(spinlock_irq, &tu->qlock)
status.queue = tu->qused;
if (copy_to_user(_status, &status, sizeof(status)))
return -EFAULT;
return 0;
}
static int snd_timer_user_start(struct file *file)
{
int err;
struct snd_timer_user *tu;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
snd_timer_stop(tu->timeri);
tu->timeri->lost = 0;
tu->last_resolution = 0;
err = snd_timer_start(tu->timeri, tu->ticks);
if (err < 0)
return err;
return 0;
}
static int snd_timer_user_stop(struct file *file)
{
int err;
struct snd_timer_user *tu;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
err = snd_timer_stop(tu->timeri);
if (err < 0)
return err;
return 0;
}
static int snd_timer_user_continue(struct file *file)
{
int err;
struct snd_timer_user *tu;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
/* start timer instead of continue if it's not used before */
if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
return snd_timer_user_start(file);
tu->timeri->lost = 0;
err = snd_timer_continue(tu->timeri);
if (err < 0)
return err;
return 0;
}
static int snd_timer_user_pause(struct file *file)
{
int err;
struct snd_timer_user *tu;
tu = file->private_data;
if (!tu->timeri)
return -EBADFD;
err = snd_timer_pause(tu->timeri);
if (err < 0)
return err;
return 0;
}
static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,
unsigned int cmd, bool compat)
{
int __user *p = argp;
int xarg, old_tread;
if (tu->timeri) /* too late */
return -EBUSY;
if (get_user(xarg, p))
return -EFAULT;
old_tread = tu->tread;
if (!xarg)
tu->tread = TREAD_FORMAT_NONE;
else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||
(IS_ENABLED(CONFIG_64BIT) && !compat))
tu->tread = TREAD_FORMAT_TIME64;
else
tu->tread = TREAD_FORMAT_TIME32;
if (tu->tread != old_tread &&
realloc_user_queue(tu, tu->queue_size) < 0) {
tu->tread = old_tread;
return -ENOMEM;
}
return 0;
}
enum {
SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
};
#ifdef CONFIG_SND_UTIMER
/*
* Since userspace-driven timers are passed to userspace, we need to have an identifier
* which will allow us to use them (basically, the subdevice number of udriven timer).
*/
static DEFINE_IDA(snd_utimer_ids);
static void snd_utimer_put_id(struct snd_utimer *utimer)
{
int timer_id = utimer->id;
snd_BUG_ON(timer_id < 0 || timer_id >= SNDRV_UTIMERS_MAX_COUNT);
ida_free(&snd_utimer_ids, timer_id);
}
static int snd_utimer_take_id(void)
{
return ida_alloc_max(&snd_utimer_ids, SNDRV_UTIMERS_MAX_COUNT - 1, GFP_KERNEL);
}
static void snd_utimer_free(struct snd_utimer *utimer)
{
snd_timer_free(utimer->timer);
snd_utimer_put_id(utimer);
kfree(utimer->name);
kfree(utimer);
}
static int snd_utimer_release(struct inode *inode, struct file *file)
{
struct snd_utimer *utimer = (struct snd_utimer *)file->private_data;
snd_utimer_free(utimer);
return 0;
}
static int snd_utimer_trigger(struct file *file)
{
struct snd_utimer *utimer = (struct snd_utimer *)file->private_data;
snd_timer_interrupt(utimer->timer, utimer->timer->sticks);
return 0;
}
static long snd_utimer_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
{
switch (ioctl) {
case SNDRV_TIMER_IOCTL_TRIGGER:
return snd_utimer_trigger(file);
}
return -ENOTTY;
}
static const struct file_operations snd_utimer_fops = {
.llseek = noop_llseek,
.release = snd_utimer_release,
.unlocked_ioctl = snd_utimer_ioctl,
};
static int snd_utimer_start(struct snd_timer *t)
{
return 0;
}
static int snd_utimer_stop(struct snd_timer *t)
{
return 0;
}
static int snd_utimer_open(struct snd_timer *t)
{
return 0;
}
static int snd_utimer_close(struct snd_timer *t)
{
return 0;
}
static const struct snd_timer_hardware timer_hw = {
.flags = SNDRV_TIMER_HW_AUTO | SNDRV_TIMER_HW_WORK,
.open = snd_utimer_open,
.close = snd_utimer_close,
.start = snd_utimer_start,
.stop = snd_utimer_stop,
};
static int snd_utimer_create(struct snd_timer_uinfo *utimer_info,
struct snd_utimer **r_utimer)
{
struct snd_utimer *utimer;
struct snd_timer *timer;
struct snd_timer_id tid;
int utimer_id;
int err = 0;
if (!utimer_info || utimer_info->resolution == 0)
return -EINVAL;
utimer = kzalloc(sizeof(*utimer), GFP_KERNEL);
if (!utimer)
return -ENOMEM;
/* We hold the ioctl lock here so we won't get a race condition when allocating id */
utimer_id = snd_utimer_take_id();
if (utimer_id < 0) {
err = utimer_id;
goto err_take_id;
}
utimer->name = kasprintf(GFP_KERNEL, "snd-utimer%d", utimer_id);
if (!utimer->name) {
err = -ENOMEM;
goto err_get_name;
}
utimer->id = utimer_id;
tid.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
tid.card = -1;
tid.device = SNDRV_TIMER_GLOBAL_UDRIVEN;
tid.subdevice = utimer_id;
err = snd_timer_new(NULL, utimer->name, &tid, &timer);
if (err < 0) {
pr_err("Can't create userspace-driven timer\n");
goto err_timer_new;
}
timer->module = THIS_MODULE;
timer->hw = timer_hw;
timer->hw.resolution = utimer_info->resolution;
timer->hw.ticks = 1;
timer->max_instances = MAX_SLAVE_INSTANCES;
utimer->timer = timer;
err = snd_timer_global_register(timer);
if (err < 0) {
pr_err("Can't register a userspace-driven timer\n");
goto err_timer_reg;
}
*r_utimer = utimer;
return 0;
err_timer_reg:
snd_timer_free(timer);
err_timer_new:
kfree(utimer->name);
err_get_name:
snd_utimer_put_id(utimer);
err_take_id:
kfree(utimer);
return err;
}
static int snd_utimer_ioctl_create(struct file *file,
struct snd_timer_uinfo __user *_utimer_info)
{
struct snd_utimer *utimer;
struct snd_timer_uinfo *utimer_info __free(kfree) = NULL;
int err, timer_fd;
utimer_info = memdup_user(_utimer_info, sizeof(*utimer_info));
if (IS_ERR(utimer_info))
return PTR_ERR(utimer_info);
err = snd_utimer_create(utimer_info, &utimer);
if (err < 0)
return err;
utimer_info->id = utimer->id;
timer_fd = anon_inode_getfd(utimer->name, &snd_utimer_fops, utimer, O_RDWR | O_CLOEXEC);
if (timer_fd < 0) {
snd_utimer_free(utimer);
return timer_fd;
}
utimer_info->fd = timer_fd;
err = copy_to_user(_utimer_info, utimer_info, sizeof(*utimer_info));
if (err) {
/*
* "Leak" the fd, as there is nothing we can do about it.
* It might have been closed already since anon_inode_getfd
* makes it available for userspace.
*
* We have to rely on the process exit path to do any
* necessary cleanup (e.g. releasing the file).
*/
return -EFAULT;
}
return 0;
}
#else
static int snd_utimer_ioctl_create(struct file *file,
struct snd_timer_uinfo __user *_utimer_info)
{
return -ENOTTY;
}
#endif
static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
unsigned long arg, bool compat)
{
struct snd_timer_user *tu;
void __user *argp = (void __user *)arg;
int __user *p = argp;
tu = file->private_data;
switch (cmd) {
case SNDRV_TIMER_IOCTL_PVERSION:
return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
return snd_timer_user_next_device(argp);
case SNDRV_TIMER_IOCTL_TREAD_OLD:
case SNDRV_TIMER_IOCTL_TREAD64:
return snd_timer_user_tread(argp, tu, cmd, compat);
case SNDRV_TIMER_IOCTL_GINFO:
return snd_timer_user_ginfo(file, argp);
case SNDRV_TIMER_IOCTL_GPARAMS:
return snd_timer_user_gparams(file, argp);
case SNDRV_TIMER_IOCTL_GSTATUS:
return snd_timer_user_gstatus(file, argp);
case SNDRV_TIMER_IOCTL_SELECT:
return snd_timer_user_tselect(file, argp);
case SNDRV_TIMER_IOCTL_INFO:
return snd_timer_user_info(file, argp);
case SNDRV_TIMER_IOCTL_PARAMS:
return snd_timer_user_params(file, argp);
case SNDRV_TIMER_IOCTL_STATUS32:
return snd_timer_user_status32(file, argp);
case SNDRV_TIMER_IOCTL_STATUS64:
return snd_timer_user_status64(file, argp);
case SNDRV_TIMER_IOCTL_START:
case SNDRV_TIMER_IOCTL_START_OLD:
return snd_timer_user_start(file);
case SNDRV_TIMER_IOCTL_STOP:
case SNDRV_TIMER_IOCTL_STOP_OLD:
return snd_timer_user_stop(file);
case SNDRV_TIMER_IOCTL_CONTINUE:
case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
return snd_timer_user_continue(file);
case SNDRV_TIMER_IOCTL_PAUSE:
case SNDRV_TIMER_IOCTL_PAUSE_OLD:
return snd_timer_user_pause(file);
case SNDRV_TIMER_IOCTL_CREATE:
return snd_utimer_ioctl_create(file, argp);
}
return -ENOTTY;
}
static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct snd_timer_user *tu = file->private_data;
guard(mutex)(&tu->ioctl_lock);
return __snd_timer_user_ioctl(file, cmd, arg, false);
}
static int snd_timer_user_fasync(int fd, struct file * file, int on)
{
struct snd_timer_user *tu;
tu = file->private_data;
return snd_fasync_helper(fd, file, on, &tu->fasync);
}
static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
size_t count, loff_t *offset)
{
struct snd_timer_tread64 *tread;
struct snd_timer_tread32 tread32;
struct snd_timer_user *tu;
long result = 0, unit;
int qhead;
int err = 0;
tu = file->private_data;
switch (tu->tread) {
case TREAD_FORMAT_TIME64:
unit = sizeof(struct snd_timer_tread64);
break;
case TREAD_FORMAT_TIME32:
unit = sizeof(struct snd_timer_tread32);
break;
case TREAD_FORMAT_NONE:
unit = sizeof(struct snd_timer_read);
break;
default:
WARN_ONCE(1, "Corrupt snd_timer_user\n");
return -ENOTSUPP;
}
mutex_lock(&tu->ioctl_lock);
spin_lock_irq(&tu->qlock);
while ((long)count - result >= unit) {
while (!tu->qused) {
wait_queue_entry_t wait;
if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
err = -EAGAIN;
goto _error;
}
set_current_state(TASK_INTERRUPTIBLE);
init_waitqueue_entry(&wait, current);
add_wait_queue(&tu->qchange_sleep, &wait);
spin_unlock_irq(&tu->qlock);
mutex_unlock(&tu->ioctl_lock);
schedule();
mutex_lock(&tu->ioctl_lock);
spin_lock_irq(&tu->qlock);
remove_wait_queue(&tu->qchange_sleep, &wait);
if (tu->disconnected) {
err = -ENODEV;
goto _error;
}
if (signal_pending(current)) {
err = -ERESTARTSYS;
goto _error;
}
}
qhead = tu->qhead++;
tu->qhead %= tu->queue_size;
tu->qused--;
spin_unlock_irq(&tu->qlock);
tread = &tu->tqueue[qhead];
switch (tu->tread) {
case TREAD_FORMAT_TIME64:
if (copy_to_user(buffer, tread,
sizeof(struct snd_timer_tread64)))
err = -EFAULT;
break;
case TREAD_FORMAT_TIME32:
memset(&tread32, 0, sizeof(tread32));
tread32 = (struct snd_timer_tread32) {
.event = tread->event,
.tstamp_sec = tread->tstamp_sec,
.tstamp_nsec = tread->tstamp_nsec,
.val = tread->val,
};
if (copy_to_user(buffer, &tread32, sizeof(tread32)))
err = -EFAULT;
break;
case TREAD_FORMAT_NONE:
if (copy_to_user(buffer, &tu->queue[qhead],
sizeof(struct snd_timer_read)))
err = -EFAULT;
break;
default:
err = -ENOTSUPP;
break;
}
spin_lock_irq(&tu->qlock);
if (err < 0)
goto _error;
result += unit;
buffer += unit;
}
_error:
spin_unlock_irq(&tu->qlock);
mutex_unlock(&tu->ioctl_lock);
return result > 0 ? result : err;
}
static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
{
__poll_t mask;
struct snd_timer_user *tu;
tu = file->private_data;
poll_wait(file, &tu->qchange_sleep, wait);
mask = 0;
guard(spinlock_irq)(&tu->qlock);
if (tu->qused)
mask |= EPOLLIN | EPOLLRDNORM;
if (tu->disconnected)
mask |= EPOLLERR;
return mask;
}
#ifdef CONFIG_COMPAT
#include "timer_compat.c"
#else
#define snd_timer_user_ioctl_compat NULL
#endif
static const struct file_operations snd_timer_f_ops =
{
.owner = THIS_MODULE,
.read = snd_timer_user_read,
.open = snd_timer_user_open,
.release = snd_timer_user_release,
.poll = snd_timer_user_poll,
.unlocked_ioctl = snd_timer_user_ioctl,
.compat_ioctl = snd_timer_user_ioctl_compat,
.fasync = snd_timer_user_fasync,
};
/* unregister the system timer */
static void snd_timer_free_all(void)
{
struct snd_timer *timer, *n;
list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
snd_timer_free(timer);
}
static struct device *timer_dev;
/*
* ENTRY functions
*/
static int __init alsa_timer_init(void)
{
int err;
err = snd_device_alloc(&timer_dev, NULL);
if (err < 0)
return err;
dev_set_name(timer_dev, "timer");
#ifdef SNDRV_OSS_INFO_DEV_TIMERS
snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
"system timer");
#endif
err = snd_timer_register_system();
if (err < 0) {
pr_err("ALSA: unable to register system timer (%i)\n", err);
goto put_timer;
}
err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
&snd_timer_f_ops, NULL, timer_dev);
if (err < 0) {
pr_err("ALSA: unable to register timer device (%i)\n", err);
snd_timer_free_all();
goto put_timer;
}
snd_timer_proc_init();
return 0;
put_timer:
put_device(timer_dev);
return err;
}
static void __exit alsa_timer_exit(void)
{
snd_unregister_device(timer_dev);
snd_timer_free_all();
put_device(timer_dev);
snd_timer_proc_done();
#ifdef SNDRV_OSS_INFO_DEV_TIMERS
snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
#endif
}
module_init(alsa_timer_init)
module_exit(alsa_timer_exit)
Codebase Browser
linux