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ALSA: pcm: Hide local_irq_disable/enable() and local_irqsave/restore()

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The snd_pcm_stream_lock_irq*() functions decouple disabling interrupts
from the actual locking process. This does not work as expected if the
locking primitives are replaced like on preempt-rt.

Provide one function for locking which uses correct locking primitives.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Anna-Maria Gleixner 2018-05-04 17:28:10 +02:00 committed by Takashi Iwai
parent 9ea19e7e76
commit 10aa7cad37
1 changed files with 57 additions and 28 deletions
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85
sound/core/pcm_native.c
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@ -99,6 +99,57 @@ static inline void down_write_nonblock(struct rw_semaphore *lock)
cond_resched(); cond_resched();
} }
#define PCM_LOCK_DEFAULT 0
#define PCM_LOCK_IRQ 1
#define PCM_LOCK_IRQSAVE 2
static unsigned long __snd_pcm_stream_lock_mode(struct snd_pcm_substream *substream,
unsigned int mode)
{
unsigned long flags = 0;
if (substream->pcm->nonatomic) {
down_read_nested(&snd_pcm_link_rwsem, SINGLE_DEPTH_NESTING);
mutex_lock(&substream->self_group.mutex);
} else {
switch (mode) {
case PCM_LOCK_DEFAULT:
read_lock(&snd_pcm_link_rwlock);
break;
case PCM_LOCK_IRQ:
read_lock_irq(&snd_pcm_link_rwlock);
break;
case PCM_LOCK_IRQSAVE:
read_lock_irqsave(&snd_pcm_link_rwlock, flags);
break;
}
spin_lock(&substream->self_group.lock);
}
return flags;
}
static void __snd_pcm_stream_unlock_mode(struct snd_pcm_substream *substream,
unsigned int mode, unsigned long flags)
{
if (substream->pcm->nonatomic) {
mutex_unlock(&substream->self_group.mutex);
up_read(&snd_pcm_link_rwsem);
} else {
spin_unlock(&substream->self_group.lock);
switch (mode) {
case PCM_LOCK_DEFAULT:
read_unlock(&snd_pcm_link_rwlock);
break;
case PCM_LOCK_IRQ:
read_unlock_irq(&snd_pcm_link_rwlock);
break;
case PCM_LOCK_IRQSAVE:
read_unlock_irqrestore(&snd_pcm_link_rwlock, flags);
break;
}
}
}
/** /**
* snd_pcm_stream_lock - Lock the PCM stream * snd_pcm_stream_lock - Lock the PCM stream
* @substream: PCM substream * @substream: PCM substream
@ -109,13 +160,7 @@ static inline void down_write_nonblock(struct rw_semaphore *lock)
*/ */
void snd_pcm_stream_lock(struct snd_pcm_substream *substream) void snd_pcm_stream_lock(struct snd_pcm_substream *substream)
{ {
if (substream->pcm->nonatomic) { __snd_pcm_stream_lock_mode(substream, PCM_LOCK_DEFAULT);
down_read_nested(&snd_pcm_link_rwsem, SINGLE_DEPTH_NESTING);
mutex_lock(&substream->self_group.mutex);
} else {
read_lock(&snd_pcm_link_rwlock);
spin_lock(&substream->self_group.lock);
}
} }
EXPORT_SYMBOL_GPL(snd_pcm_stream_lock); EXPORT_SYMBOL_GPL(snd_pcm_stream_lock);
@ -127,13 +172,7 @@ EXPORT_SYMBOL_GPL(snd_pcm_stream_lock);
*/ */
void snd_pcm_stream_unlock(struct snd_pcm_substream *substream) void snd_pcm_stream_unlock(struct snd_pcm_substream *substream)
{ {
if (substream->pcm->nonatomic) { __snd_pcm_stream_unlock_mode(substream, PCM_LOCK_DEFAULT, 0);
mutex_unlock(&substream->self_group.mutex);
up_read(&snd_pcm_link_rwsem);
} else {
spin_unlock(&substream->self_group.lock);
read_unlock(&snd_pcm_link_rwlock);
}
} }
EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock); EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock);
@ -147,9 +186,7 @@ EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock);
*/ */
void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream) void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream)
{ {
if (!substream->pcm->nonatomic) __snd_pcm_stream_lock_mode(substream, PCM_LOCK_IRQ);
local_irq_disable();
snd_pcm_stream_lock(substream);
} }
EXPORT_SYMBOL_GPL(snd_pcm_stream_lock_irq); EXPORT_SYMBOL_GPL(snd_pcm_stream_lock_irq);
@ -161,19 +198,13 @@ EXPORT_SYMBOL_GPL(snd_pcm_stream_lock_irq);
*/ */
void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream) void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream)
{ {
snd_pcm_stream_unlock(substream); __snd_pcm_stream_unlock_mode(substream, PCM_LOCK_IRQ, 0);
if (!substream->pcm->nonatomic)
local_irq_enable();
} }
EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irq); EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irq);
unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream) unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream)
{ {
unsigned long flags = 0; return __snd_pcm_stream_lock_mode(substream, PCM_LOCK_IRQSAVE);
if (!substream->pcm->nonatomic)
local_irq_save(flags);
snd_pcm_stream_lock(substream);
return flags;
} }
EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave); EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave);
@ -187,9 +218,7 @@ EXPORT_SYMBOL_GPL(_snd_pcm_stream_lock_irqsave);
void snd_pcm_stream_unlock_irqrestore(struct snd_pcm_substream *substream, void snd_pcm_stream_unlock_irqrestore(struct snd_pcm_substream *substream,
unsigned long flags) unsigned long flags)
{ {
snd_pcm_stream_unlock(substream); __snd_pcm_stream_unlock_mode(substream, PCM_LOCK_IRQSAVE, flags);
if (!substream->pcm->nonatomic)
local_irq_restore(flags);
} }
EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irqrestore); EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irqrestore);