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>

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index 13f72f5b18d2..a95a46bcd339 100644
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -2073,7 +2073,7 @@ static irqreturn_t efx_ef10_msi_interrupt(int irq, void *dev_id)
 	netif_vdbg(efx, intr, efx->net_dev,
 		   "IRQ %d on CPU %d\n", irq, raw_smp_processor_id());
 
-	if (likely(ACCESS_ONCE(efx->irq_soft_enabled))) {
+	if (likely(READ_ONCE(efx->irq_soft_enabled))) {
 		/* Note test interrupts */
 		if (context->index == efx->irq_level)
 			efx->last_irq_cpu = raw_smp_processor_id();
@@ -2088,7 +2088,7 @@ static irqreturn_t efx_ef10_msi_interrupt(int irq, void *dev_id)
 static irqreturn_t efx_ef10_legacy_interrupt(int irq, void *dev_id)
 {
 	struct efx_nic *efx = dev_id;
-	bool soft_enabled = ACCESS_ONCE(efx->irq_soft_enabled);
+	bool soft_enabled = READ_ONCE(efx->irq_soft_enabled);
 	struct efx_channel *channel;
 	efx_dword_t reg;
 	u32 queues;
@@ -3291,7 +3291,7 @@ static int efx_ef10_handle_rx_event(struct efx_channel *channel,
 	bool rx_cont;
 	u16 flags = 0;
 
-	if (unlikely(ACCESS_ONCE(efx->reset_pending)))
+	if (unlikely(READ_ONCE(efx->reset_pending)))
 		return 0;
 
 	/* Basic packet information */
@@ -3428,7 +3428,7 @@ efx_ef10_handle_tx_event(struct efx_channel *channel, efx_qword_t *event)
 	unsigned int tx_ev_q_label;
 	int tx_descs = 0;
 
-	if (unlikely(ACCESS_ONCE(efx->reset_pending)))
+	if (unlikely(READ_ONCE(efx->reset_pending)))
 		return 0;
 
 	if (unlikely(EFX_QWORD_FIELD(*event, ESF_DZ_TX_DROP_EVENT)))
@@ -5316,7 +5316,7 @@ static void efx_ef10_filter_remove_old(struct efx_nic *efx)
 	int i;
 
 	for (i = 0; i < HUNT_FILTER_TBL_ROWS; i++) {
-		if (ACCESS_ONCE(table->entry[i].spec) &
+		if (READ_ONCE(table->entry[i].spec) &
 		    EFX_EF10_FILTER_FLAG_AUTO_OLD) {
 			rc = efx_ef10_filter_remove_internal(efx,
 					1U << EFX_FILTER_PRI_AUTO, i, true);