From 6aa7de059173a986114ac43b8f50b297a86f09a8 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland@arm.com>
Date: Mon, 23 Oct 2017 14:07:29 -0700
Subject: locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE()
patterns to READ_ONCE()/WRITE_ONCE()
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>
---
drivers/crypto/caam/jr.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
(limited to 'drivers/crypto/caam')
diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c
index d258953ff488..f4f258075b89 100644
--- a/drivers/crypto/caam/jr.c
+++ b/drivers/crypto/caam/jr.c
@@ -172,7 +172,7 @@ static void caam_jr_dequeue(unsigned long devarg)
while (rd_reg32(&jrp->rregs->outring_used)) {
- head = ACCESS_ONCE(jrp->head);
+ head = READ_ONCE(jrp->head);
spin_lock(&jrp->outlock);
@@ -341,7 +341,7 @@ int caam_jr_enqueue(struct device *dev, u32 *desc,
spin_lock_bh(&jrp->inplock);
head = jrp->head;
- tail = ACCESS_ONCE(jrp->tail);
+ tail = READ_ONCE(jrp->tail);
if (!rd_reg32(&jrp->rregs->inpring_avail) ||
CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
--
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