// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ALSA sequencer Timing queue handling
* Copyright (c) 1998-1999 by Frank van de Pol <[email protected]>
*
* MAJOR CHANGES
* Nov. 13, 1999 Takashi Iwai <[email protected]>
* - Queues are allocated dynamically via ioctl.
* - When owner client is deleted, all owned queues are deleted, too.
* - Owner of unlocked queue is kept unmodified even if it is
* manipulated by other clients.
* - Owner field in SET_QUEUE_OWNER ioctl must be identical with the
* caller client. i.e. Changing owner to a third client is not
* allowed.
*
* Aug. 30, 2000 Takashi Iwai
* - Queues are managed in static array again, but with better way.
* The API itself is identical.
* - The queue is locked when struct snd_seq_queue pointer is returned via
* queueptr(). This pointer *MUST* be released afterward by
* queuefree(ptr).
* - Addition of experimental sync support.
*/
#include <linux/init.h>
#include <linux/slab.h>
#include <sound/core.h>
#include "seq_memory.h"
#include "seq_queue.h"
#include "seq_clientmgr.h"
#include "seq_fifo.h"
#include "seq_timer.h"
#include "seq_info.h"
/* list of allocated queues */
static struct snd_seq_queue *queue_list[SNDRV_SEQ_MAX_QUEUES];
static DEFINE_SPINLOCK(queue_list_lock);
/* number of queues allocated */
static int num_queues;
int snd_seq_queue_get_cur_queues(void)
{
return num_queues;
}
/*----------------------------------------------------------------*/
/* assign queue id and insert to list */
static int queue_list_add(struct snd_seq_queue *q)
{
int i;
guard(spinlock_irqsave)(&queue_list_lock);
for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
if (! queue_list[i]) {
queue_list[i] = q;
q->queue = i;
num_queues++;
return i;
}
}
return -1;
}
static struct snd_seq_queue *queue_list_remove(int id, int client)
{
struct snd_seq_queue *q;
guard(spinlock_irqsave)(&queue_list_lock);
q = queue_list[id];
if (q) {
guard(spinlock)(&q->owner_lock);
if (q->owner == client) {
/* found */
q->klocked = 1;
queue_list[id] = NULL;
num_queues--;
return q;
}
}
return NULL;
}
/*----------------------------------------------------------------*/
/* create new queue (constructor) */
static struct snd_seq_queue *queue_new(int owner, int locked)
{
struct snd_seq_queue *q;
q = kzalloc(sizeof(*q), GFP_KERNEL);
if (!q)
return NULL;
spin_lock_init(&q->owner_lock);
spin_lock_init(&q->check_lock);
mutex_init(&q->timer_mutex);
snd_use_lock_init(&q->use_lock);
q->queue = -1;
q->tickq = snd_seq_prioq_new();
q->timeq = snd_seq_prioq_new();
q->timer = snd_seq_timer_new();
if (q->tickq == NULL || q->timeq == NULL || q->timer == NULL) {
snd_seq_prioq_delete(&q->tickq);
snd_seq_prioq_delete(&q->timeq);
snd_seq_timer_delete(&q->timer);
kfree(q);
return NULL;
}
q->owner = owner;
q->locked = locked;
q->klocked = 0;
return q;
}
/* delete queue (destructor) */
static void queue_delete(struct snd_seq_queue *q)
{
/* stop and release the timer */
mutex_lock(&q->timer_mutex);
snd_seq_timer_stop(q->timer);
snd_seq_timer_close(q);
mutex_unlock(&q->timer_mutex);
/* wait until access free */
snd_use_lock_sync(&q->use_lock);
/* release resources... */
snd_seq_prioq_delete(&q->tickq);
snd_seq_prioq_delete(&q->timeq);
snd_seq_timer_delete(&q->timer);
kfree(q);
}
/*----------------------------------------------------------------*/
/* delete all existing queues */
void snd_seq_queues_delete(void)
{
int i;
/* clear list */
for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
if (queue_list[i])
queue_delete(queue_list[i]);
}
}
static void queue_use(struct snd_seq_queue *queue, int client, int use);
/* allocate a new queue -
* return pointer to new queue or ERR_PTR(-errno) for error
* The new queue's use_lock is set to 1. It is the caller's responsibility to
* call snd_use_lock_free(&q->use_lock).
*/
struct snd_seq_queue *snd_seq_queue_alloc(int client, int locked, unsigned int info_flags)
{
struct snd_seq_queue *q;
q = queue_new(client, locked);
if (q == NULL)
return ERR_PTR(-ENOMEM);
q->info_flags = info_flags;
queue_use(q, client, 1);
snd_use_lock_use(&q->use_lock);
if (queue_list_add(q) < 0) {
snd_use_lock_free(&q->use_lock);
queue_delete(q);
return ERR_PTR(-ENOMEM);
}
return q;
}
/* delete a queue - queue must be owned by the client */
int snd_seq_queue_delete(int client, int queueid)
{
struct snd_seq_queue *q;
if (queueid < 0 || queueid >= SNDRV_SEQ_MAX_QUEUES)
return -EINVAL;
q = queue_list_remove(queueid, client);
if (q == NULL)
return -EINVAL;
queue_delete(q);
return 0;
}
/* return pointer to queue structure for specified id */
struct snd_seq_queue *queueptr(int queueid)
{
struct snd_seq_queue *q;
if (queueid < 0 || queueid >= SNDRV_SEQ_MAX_QUEUES)
return NULL;
guard(spinlock_irqsave)(&queue_list_lock);
q = queue_list[queueid];
if (q)
snd_use_lock_use(&q->use_lock);
return q;
}
/* return the (first) queue matching with the specified name */
struct snd_seq_queue *snd_seq_queue_find_name(char *name)
{
int i;
struct snd_seq_queue *q;
for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
q = queueptr(i);
if (q) {
if (strncmp(q->name, name, sizeof(q->name)) == 0)
return q;
queuefree(q);
}
}
return NULL;
}
/* -------------------------------------------------------- */
#define MAX_CELL_PROCESSES_IN_QUEUE 1000
void snd_seq_check_queue(struct snd_seq_queue *q, int atomic, int hop)
{
struct snd_seq_event_cell *cell;
snd_seq_tick_time_t cur_tick;
snd_seq_real_time_t cur_time;
int processed = 0;
if (q == NULL)
return;
/* make this function non-reentrant */
scoped_guard(spinlock_irqsave, &q->check_lock) {
if (q->check_blocked) {
q->check_again = 1;
return; /* other thread is already checking queues */
}
q->check_blocked = 1;
}
__again:
/* Process tick queue... */
cur_tick = snd_seq_timer_get_cur_tick(q->timer);
for (;;) {
cell = snd_seq_prioq_cell_out(q->tickq, &cur_tick);
if (!cell)
break;
snd_seq_dispatch_event(cell, atomic, hop);
if (++processed >= MAX_CELL_PROCESSES_IN_QUEUE)
goto out; /* the rest processed at the next batch */
}
/* Process time queue... */
cur_time = snd_seq_timer_get_cur_time(q->timer, false);
for (;;) {
cell = snd_seq_prioq_cell_out(q->timeq, &cur_time);
if (!cell)
break;
snd_seq_dispatch_event(cell, atomic, hop);
if (++processed >= MAX_CELL_PROCESSES_IN_QUEUE)
goto out; /* the rest processed at the next batch */
}
out:
/* free lock */
scoped_guard(spinlock_irqsave, &q->check_lock) {
if (q->check_again) {
q->check_again = 0;
if (processed < MAX_CELL_PROCESSES_IN_QUEUE)
goto __again;
}
q->check_blocked = 0;
}
}
/* enqueue a event to singe queue */
int snd_seq_enqueue_event(struct snd_seq_event_cell *cell, int atomic, int hop)
{
int dest, err;
struct snd_seq_queue *q;
if (snd_BUG_ON(!cell))
return -EINVAL;
dest = cell->event.queue; /* destination queue */
q = queueptr(dest);
if (q == NULL)
return -EINVAL;
/* handle relative time stamps, convert them into absolute */
if ((cell->event.flags & SNDRV_SEQ_TIME_MODE_MASK) == SNDRV_SEQ_TIME_MODE_REL) {
switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
case SNDRV_SEQ_TIME_STAMP_TICK:
cell->event.time.tick += q->timer->tick.cur_tick;
break;
case SNDRV_SEQ_TIME_STAMP_REAL:
snd_seq_inc_real_time(&cell->event.time.time,
&q->timer->cur_time);
break;
}
cell->event.flags &= ~SNDRV_SEQ_TIME_MODE_MASK;
cell->event.flags |= SNDRV_SEQ_TIME_MODE_ABS;
}
/* enqueue event in the real-time or midi queue */
switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
case SNDRV_SEQ_TIME_STAMP_TICK:
err = snd_seq_prioq_cell_in(q->tickq, cell);
break;
case SNDRV_SEQ_TIME_STAMP_REAL:
default:
err = snd_seq_prioq_cell_in(q->timeq, cell);
break;
}
if (err < 0) {
queuefree(q); /* unlock */
return err;
}
/* trigger dispatching */
snd_seq_check_queue(q, atomic, hop);
queuefree(q); /* unlock */
return 0;
}
/*----------------------------------------------------------------*/
static inline int check_access(struct snd_seq_queue *q, int client)
{
return (q->owner == client) || (!q->locked && !q->klocked);
}
/* check if the client has permission to modify queue parameters.
* if it does, lock the queue
*/
static int queue_access_lock(struct snd_seq_queue *q, int client)
{
int access_ok;
guard(spinlock_irqsave)(&q->owner_lock);
access_ok = check_access(q, client);
if (access_ok)
q->klocked = 1;
return access_ok;
}
/* unlock the queue */
static inline void queue_access_unlock(struct snd_seq_queue *q)
{
guard(spinlock_irqsave)(&q->owner_lock);
q->klocked = 0;
}
/* exported - only checking permission */
int snd_seq_queue_check_access(int queueid, int client)
{
struct snd_seq_queue *q = queueptr(queueid);
int access_ok;
if (! q)
return 0;
scoped_guard(spinlock_irqsave, &q->owner_lock)
access_ok = check_access(q, client);
queuefree(q);
return access_ok;
}
/*----------------------------------------------------------------*/
/*
* change queue's owner and permission
*/
int snd_seq_queue_set_owner(int queueid, int client, int locked)
{
struct snd_seq_queue *q = queueptr(queueid);
if (q == NULL)
return -EINVAL;
if (! queue_access_lock(q, client)) {
queuefree(q);
return -EPERM;
}
scoped_guard(spinlock_irqsave, &q->owner_lock) {
q->locked = locked ? 1 : 0;
q->owner = client;
}
queue_access_unlock(q);
queuefree(q);
return 0;
}
/*----------------------------------------------------------------*/
/* open timer -
* q->use mutex should be down before calling this function to avoid
* confliction with snd_seq_queue_use()
*/
int snd_seq_queue_timer_open(int queueid)
{
int result = 0;
struct snd_seq_queue *queue;
struct snd_seq_timer *tmr;
queue = queueptr(queueid);
if (queue == NULL)
return -EINVAL;
tmr = queue->timer;
result = snd_seq_timer_open(queue);
if (result < 0) {
snd_seq_timer_defaults(tmr);
result = snd_seq_timer_open(queue);
}
queuefree(queue);
return result;
}
/* close timer -
* q->use mutex should be down before calling this function
*/
int snd_seq_queue_timer_close(int queueid)
{
struct snd_seq_queue *queue;
int result = 0;
queue = queueptr(queueid);
if (queue == NULL)
return -EINVAL;
snd_seq_timer_close(queue);
queuefree(queue);
return result;
}
/* change queue tempo and ppq */
int snd_seq_queue_timer_set_tempo(int queueid, int client,
struct snd_seq_queue_tempo *info)
{
struct snd_seq_queue *q = queueptr(queueid);
int result;
if (q == NULL)
return -EINVAL;
if (! queue_access_lock(q, client)) {
queuefree(q);
return -EPERM;
}
result = snd_seq_timer_set_tempo_ppq(q->timer, info->tempo, info->ppq,
info->tempo_base);
if (result >= 0 && info->skew_base > 0)
result = snd_seq_timer_set_skew(q->timer, info->skew_value,
info->skew_base);
queue_access_unlock(q);
queuefree(q);
return result;
}
/* use or unuse this queue */
static void queue_use(struct snd_seq_queue *queue, int client, int use)
{
if (use) {
if (!test_and_set_bit(client, queue->clients_bitmap))
queue->clients++;
} else {
if (test_and_clear_bit(client, queue->clients_bitmap))
queue->clients--;
}
if (queue->clients) {
if (use && queue->clients == 1)
snd_seq_timer_defaults(queue->timer);
snd_seq_timer_open(queue);
} else {
snd_seq_timer_close(queue);
}
}
/* use or unuse this queue -
* if it is the first client, starts the timer.
* if it is not longer used by any clients, stop the timer.
*/
int snd_seq_queue_use(int queueid, int client, int use)
{
struct snd_seq_queue *queue;
queue = queueptr(queueid);
if (queue == NULL)
return -EINVAL;
mutex_lock(&queue->timer_mutex);
queue_use(queue, client, use);
mutex_unlock(&queue->timer_mutex);
queuefree(queue);
return 0;
}
/*
* check if queue is used by the client
* return negative value if the queue is invalid.
* return 0 if not used, 1 if used.
*/
int snd_seq_queue_is_used(int queueid, int client)
{
struct snd_seq_queue *q;
int result;
q = queueptr(queueid);
if (q == NULL)
return -EINVAL; /* invalid queue */
result = test_bit(client, q->clients_bitmap) ? 1 : 0;
queuefree(q);
return result;
}
/*----------------------------------------------------------------*/
/* final stage notification -
* remove cells for no longer exist client (for non-owned queue)
* or delete this queue (for owned queue)
*/
void snd_seq_queue_client_leave(int client)
{
int i;
struct snd_seq_queue *q;
/* delete own queues from queue list */
for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
q = queue_list_remove(i, client);
if (q)
queue_delete(q);
}
/* remove cells from existing queues -
* they are not owned by this client
*/
for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
q = queueptr(i);
if (!q)
continue;
if (test_bit(client, q->clients_bitmap)) {
snd_seq_prioq_leave(q->tickq, client, 0);
snd_seq_prioq_leave(q->timeq, client, 0);
snd_seq_queue_use(q->queue, client, 0);
}
queuefree(q);
}
}
/*----------------------------------------------------------------*/
/* remove cells from all queues */
void snd_seq_queue_client_leave_cells(int client)
{
int i;
struct snd_seq_queue *q;
for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
q = queueptr(i);
if (!q)
continue;
snd_seq_prioq_leave(q->tickq, client, 0);
snd_seq_prioq_leave(q->timeq, client, 0);
queuefree(q);
}
}
/* remove cells based on flush criteria */
void snd_seq_queue_remove_cells(int client, struct snd_seq_remove_events *info)
{
int i;
struct snd_seq_queue *q;
for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
q = queueptr(i);
if (!q)
continue;
if (test_bit(client, q->clients_bitmap) &&
(! (info->remove_mode & SNDRV_SEQ_REMOVE_DEST) ||
q->queue == info->queue)) {
snd_seq_prioq_remove_events(q->tickq, client, info);
snd_seq_prioq_remove_events(q->timeq, client, info);
}
queuefree(q);
}
}
/*----------------------------------------------------------------*/
/*
* send events to all subscribed ports
*/
static void queue_broadcast_event(struct snd_seq_queue *q, struct snd_seq_event *ev,
int atomic, int hop)
{
struct snd_seq_event sev;
sev = *ev;
sev.flags = SNDRV_SEQ_TIME_STAMP_TICK|SNDRV_SEQ_TIME_MODE_ABS;
sev.time.tick = q->timer->tick.cur_tick;
sev.queue = q->queue;
sev.data.queue.queue = q->queue;
/* broadcast events from Timer port */
sev.source.client = SNDRV_SEQ_CLIENT_SYSTEM;
sev.source.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
sev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
snd_seq_kernel_client_dispatch(SNDRV_SEQ_CLIENT_SYSTEM, &sev, atomic, hop);
}
/*
* process a received queue-control event.
* this function is exported for seq_sync.c.
*/
static void snd_seq_queue_process_event(struct snd_seq_queue *q,
struct snd_seq_event *ev,
int atomic, int hop)
{
switch (ev->type) {
case SNDRV_SEQ_EVENT_START:
snd_seq_prioq_leave(q->tickq, ev->source.client, 1);
snd_seq_prioq_leave(q->timeq, ev->source.client, 1);
if (! snd_seq_timer_start(q->timer))
queue_broadcast_event(q, ev, atomic, hop);
break;
case SNDRV_SEQ_EVENT_CONTINUE:
if (! snd_seq_timer_continue(q->timer))
queue_broadcast_event(q, ev, atomic, hop);
break;
case SNDRV_SEQ_EVENT_STOP:
snd_seq_timer_stop(q->timer);
queue_broadcast_event(q, ev, atomic, hop);
break;
case SNDRV_SEQ_EVENT_TEMPO:
snd_seq_timer_set_tempo(q->timer, ev->data.queue.param.value);
queue_broadcast_event(q, ev, atomic, hop);
break;
case SNDRV_SEQ_EVENT_SETPOS_TICK:
if (snd_seq_timer_set_position_tick(q->timer, ev->data.queue.param.time.tick) == 0) {
queue_broadcast_event(q, ev, atomic, hop);
}
break;
case SNDRV_SEQ_EVENT_SETPOS_TIME:
if (snd_seq_timer_set_position_time(q->timer, ev->data.queue.param.time.time) == 0) {
queue_broadcast_event(q, ev, atomic, hop);
}
break;
case SNDRV_SEQ_EVENT_QUEUE_SKEW:
if (snd_seq_timer_set_skew(q->timer,
ev->data.queue.param.skew.value,
ev->data.queue.param.skew.base) == 0) {
queue_broadcast_event(q, ev, atomic, hop);
}
break;
}
}
/*
* Queue control via timer control port:
* this function is exported as a callback of timer port.
*/
int snd_seq_control_queue(struct snd_seq_event *ev, int atomic, int hop)
{
struct snd_seq_queue *q;
if (snd_BUG_ON(!ev))
return -EINVAL;
q = queueptr(ev->data.queue.queue);
if (q == NULL)
return -EINVAL;
if (! queue_access_lock(q, ev->source.client)) {
queuefree(q);
return -EPERM;
}
snd_seq_queue_process_event(q, ev, atomic, hop);
queue_access_unlock(q);
queuefree(q);
return 0;
}
/*----------------------------------------------------------------*/
#ifdef CONFIG_SND_PROC_FS
/* exported to seq_info.c */
void snd_seq_info_queues_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
int i, bpm;
struct snd_seq_queue *q;
struct snd_seq_timer *tmr;
bool locked;
int owner;
for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
q = queueptr(i);
if (!q)
continue;
tmr = q->timer;
if (tmr->tempo)
bpm = (60000 * tmr->tempo_base) / tmr->tempo;
else
bpm = 0;
scoped_guard(spinlock_irq, &q->owner_lock) {
locked = q->locked;
owner = q->owner;
}
snd_iprintf(buffer, "queue %d: [%s]\n", q->queue, q->name);
snd_iprintf(buffer, "owned by client : %d\n", owner);
snd_iprintf(buffer, "lock status : %s\n", locked ? "Locked" : "Free");
snd_iprintf(buffer, "queued time events : %d\n", snd_seq_prioq_avail(q->timeq));
snd_iprintf(buffer, "queued tick events : %d\n", snd_seq_prioq_avail(q->tickq));
snd_iprintf(buffer, "timer state : %s\n", tmr->running ? "Running" : "Stopped");
snd_iprintf(buffer, "timer PPQ : %d\n", tmr->ppq);
snd_iprintf(buffer, "current tempo : %d\n", tmr->tempo);
snd_iprintf(buffer, "tempo base : %d ns\n", tmr->tempo_base);
snd_iprintf(buffer, "current BPM : %d\n", bpm);
snd_iprintf(buffer, "current time : %d.%09d s\n", tmr->cur_time.tv_sec, tmr->cur_time.tv_nsec);
snd_iprintf(buffer, "current tick : %d\n", tmr->tick.cur_tick);
snd_iprintf(buffer, "\n");
queuefree(q);
}
}
#endif /* CONFIG_SND_PROC_FS */
Codebase Browser
linux