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locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE()

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Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.

For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.

However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:

----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()

// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch

virtual patch

@ depends on patch @
expression E1, E2;
@@

- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)

@ depends on patch @
expression E;
@@

- ACCESS_ONCE(E)
+ READ_ONCE(E)
----

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Mark Rutland
2017-10-23 14:07:29 -07:00
committed by Ingo Molnar
parent b03a0fe0c5
commit 6aa7de0591
180 changed files with 383 additions and 385 deletions
Download Patch File Download Diff File Expand all files Collapse all files
sound/firewire/isight.c
+9 -9
View File
@@ -96,7 +96,7 @@ static void isight_update_pointers(struct isight *isight, unsigned int count)
ptr += count;
if (ptr >= runtime->buffer_size)
ptr -= runtime->buffer_size;
ACCESS_ONCE(isight->buffer_pointer) = ptr;
WRITE_ONCE(isight->buffer_pointer, ptr);
isight->period_counter += count;
if (isight->period_counter >= runtime->period_size) {
@@ -111,7 +111,7 @@ static void isight_samples(struct isight *isight,
struct snd_pcm_runtime *runtime;
unsigned int count1;
if (!ACCESS_ONCE(isight->pcm_running))
if (!READ_ONCE(isight->pcm_running))
return;
runtime = isight->pcm->runtime;
@@ -131,7 +131,7 @@ static void isight_samples(struct isight *isight,
static void isight_pcm_abort(struct isight *isight)
{
if (ACCESS_ONCE(isight->pcm_active))
if (READ_ONCE(isight->pcm_active))
snd_pcm_stop_xrun(isight->pcm);
}
@@ -141,7 +141,7 @@ static void isight_dropped_samples(struct isight *isight, unsigned int total)
u32 dropped;
unsigned int count1;
if (!ACCESS_ONCE(isight->pcm_running))
if (!READ_ONCE(isight->pcm_running))
return;
runtime = isight->pcm->runtime;
@@ -293,7 +293,7 @@ static int isight_hw_params(struct snd_pcm_substream *substream,
if (err < 0)
return err;
ACCESS_ONCE(isight->pcm_active) = true;
WRITE_ONCE(isight->pcm_active, true);
return 0;
}
@@ -331,7 +331,7 @@ static int isight_hw_free(struct snd_pcm_substream *substream)
{
struct isight *isight = substream->private_data;
ACCESS_ONCE(isight->pcm_active) = false;
WRITE_ONCE(isight->pcm_active, false);
mutex_lock(&isight->mutex);
isight_stop_streaming(isight);
@@ -424,10 +424,10 @@ static int isight_trigger(struct snd_pcm_substream *substream, int cmd)
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
ACCESS_ONCE(isight->pcm_running) = true;
WRITE_ONCE(isight->pcm_running, true);
break;
case SNDRV_PCM_TRIGGER_STOP:
ACCESS_ONCE(isight->pcm_running) = false;
WRITE_ONCE(isight->pcm_running, false);
break;
default:
return -EINVAL;
@@ -439,7 +439,7 @@ static snd_pcm_uframes_t isight_pointer(struct snd_pcm_substream *substream)
{
struct isight *isight = substream->private_data;
return ACCESS_ONCE(isight->buffer_pointer);
return READ_ONCE(isight->buffer_pointer);
}
static int isight_create_pcm(struct isight *isight)