linux-stable/sound/core/seq/seq_fifo.c
Takashi Iwai 24db8bbaa3 ALSA: seq: Drop superfluous error/debug messages after malloc failures
The kernel memory allocators already report the errors when the
requested allocation fails, thus we don't need to warn it again in
each caller side.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-03-10 15:41:18 +01:00

270 lines
5.8 KiB
C

/*
* ALSA sequencer FIFO
* Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <sound/core.h>
#include <linux/slab.h>
#include "seq_fifo.h"
#include "seq_lock.h"
/* FIFO */
/* create new fifo */
struct snd_seq_fifo *snd_seq_fifo_new(int poolsize)
{
struct snd_seq_fifo *f;
f = kzalloc(sizeof(*f), GFP_KERNEL);
if (!f)
return NULL;
f->pool = snd_seq_pool_new(poolsize);
if (f->pool == NULL) {
kfree(f);
return NULL;
}
if (snd_seq_pool_init(f->pool) < 0) {
snd_seq_pool_delete(&f->pool);
kfree(f);
return NULL;
}
spin_lock_init(&f->lock);
snd_use_lock_init(&f->use_lock);
init_waitqueue_head(&f->input_sleep);
atomic_set(&f->overflow, 0);
f->head = NULL;
f->tail = NULL;
f->cells = 0;
return f;
}
void snd_seq_fifo_delete(struct snd_seq_fifo **fifo)
{
struct snd_seq_fifo *f;
if (snd_BUG_ON(!fifo))
return;
f = *fifo;
if (snd_BUG_ON(!f))
return;
*fifo = NULL;
snd_seq_fifo_clear(f);
/* wake up clients if any */
if (waitqueue_active(&f->input_sleep))
wake_up(&f->input_sleep);
/* release resources...*/
/*....................*/
if (f->pool) {
snd_seq_pool_done(f->pool);
snd_seq_pool_delete(&f->pool);
}
kfree(f);
}
static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f);
/* clear queue */
void snd_seq_fifo_clear(struct snd_seq_fifo *f)
{
struct snd_seq_event_cell *cell;
unsigned long flags;
/* clear overflow flag */
atomic_set(&f->overflow, 0);
snd_use_lock_sync(&f->use_lock);
spin_lock_irqsave(&f->lock, flags);
/* drain the fifo */
while ((cell = fifo_cell_out(f)) != NULL) {
snd_seq_cell_free(cell);
}
spin_unlock_irqrestore(&f->lock, flags);
}
/* enqueue event to fifo */
int snd_seq_fifo_event_in(struct snd_seq_fifo *f,
struct snd_seq_event *event)
{
struct snd_seq_event_cell *cell;
unsigned long flags;
int err;
if (snd_BUG_ON(!f))
return -EINVAL;
snd_use_lock_use(&f->use_lock);
err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL); /* always non-blocking */
if (err < 0) {
if ((err == -ENOMEM) || (err == -EAGAIN))
atomic_inc(&f->overflow);
snd_use_lock_free(&f->use_lock);
return err;
}
/* append new cells to fifo */
spin_lock_irqsave(&f->lock, flags);
if (f->tail != NULL)
f->tail->next = cell;
f->tail = cell;
if (f->head == NULL)
f->head = cell;
f->cells++;
spin_unlock_irqrestore(&f->lock, flags);
/* wakeup client */
if (waitqueue_active(&f->input_sleep))
wake_up(&f->input_sleep);
snd_use_lock_free(&f->use_lock);
return 0; /* success */
}
/* dequeue cell from fifo */
static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f)
{
struct snd_seq_event_cell *cell;
if ((cell = f->head) != NULL) {
f->head = cell->next;
/* reset tail if this was the last element */
if (f->tail == cell)
f->tail = NULL;
cell->next = NULL;
f->cells--;
}
return cell;
}
/* dequeue cell from fifo and copy on user space */
int snd_seq_fifo_cell_out(struct snd_seq_fifo *f,
struct snd_seq_event_cell **cellp, int nonblock)
{
struct snd_seq_event_cell *cell;
unsigned long flags;
wait_queue_t wait;
if (snd_BUG_ON(!f))
return -EINVAL;
*cellp = NULL;
init_waitqueue_entry(&wait, current);
spin_lock_irqsave(&f->lock, flags);
while ((cell = fifo_cell_out(f)) == NULL) {
if (nonblock) {
/* non-blocking - return immediately */
spin_unlock_irqrestore(&f->lock, flags);
return -EAGAIN;
}
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&f->input_sleep, &wait);
spin_unlock_irq(&f->lock);
schedule();
spin_lock_irq(&f->lock);
remove_wait_queue(&f->input_sleep, &wait);
if (signal_pending(current)) {
spin_unlock_irqrestore(&f->lock, flags);
return -ERESTARTSYS;
}
}
spin_unlock_irqrestore(&f->lock, flags);
*cellp = cell;
return 0;
}
void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f,
struct snd_seq_event_cell *cell)
{
unsigned long flags;
if (cell) {
spin_lock_irqsave(&f->lock, flags);
cell->next = f->head;
f->head = cell;
f->cells++;
spin_unlock_irqrestore(&f->lock, flags);
}
}
/* polling; return non-zero if queue is available */
int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file,
poll_table *wait)
{
poll_wait(file, &f->input_sleep, wait);
return (f->cells > 0);
}
/* change the size of pool; all old events are removed */
int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize)
{
unsigned long flags;
struct snd_seq_pool *newpool, *oldpool;
struct snd_seq_event_cell *cell, *next, *oldhead;
if (snd_BUG_ON(!f || !f->pool))
return -EINVAL;
/* allocate new pool */
newpool = snd_seq_pool_new(poolsize);
if (newpool == NULL)
return -ENOMEM;
if (snd_seq_pool_init(newpool) < 0) {
snd_seq_pool_delete(&newpool);
return -ENOMEM;
}
spin_lock_irqsave(&f->lock, flags);
/* remember old pool */
oldpool = f->pool;
oldhead = f->head;
/* exchange pools */
f->pool = newpool;
f->head = NULL;
f->tail = NULL;
f->cells = 0;
/* NOTE: overflow flag is not cleared */
spin_unlock_irqrestore(&f->lock, flags);
/* release cells in old pool */
for (cell = oldhead; cell; cell = next) {
next = cell->next;
snd_seq_cell_free(cell);
}
snd_seq_pool_delete(&oldpool);
return 0;
}