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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

4
drivers/net/ethernet/sfc/falcon/efx.c
View File

@@ -2545,7 +2545,7 @@ static void ef4_reset_work(struct work_struct *data)
unsigned long pending;
enum reset_type method;
pending = ACCESS_ONCE(efx->reset_pending);
pending = READ_ONCE(efx->reset_pending);
method = fls(pending) - 1;
if ((method == RESET_TYPE_RECOVER_OR_DISABLE ||
@@ -2605,7 +2605,7 @@ void ef4_schedule_reset(struct ef4_nic *efx, enum reset_type type)
/* If we're not READY then just leave the flags set as the cue
* to abort probing or reschedule the reset later.
*/
if (ACCESS_ONCE(efx->state) != STATE_READY)
if (READ_ONCE(efx->state) != STATE_READY)
return;
queue_work(reset_workqueue, &efx->reset_work);

4
drivers/net/ethernet/sfc/falcon/falcon.c
View File

@@ -452,7 +452,7 @@ static irqreturn_t falcon_legacy_interrupt_a1(int irq, void *dev_id)
"IRQ %d on CPU %d status " EF4_OWORD_FMT "\n",
irq, raw_smp_processor_id(), EF4_OWORD_VAL(*int_ker));
if (!likely(ACCESS_ONCE(efx->irq_soft_enabled)))
if (!likely(READ_ONCE(efx->irq_soft_enabled)))
return IRQ_HANDLED;
/* Check to see if we have a serious error condition */
@@ -1372,7 +1372,7 @@ static void falcon_reconfigure_mac_wrapper(struct ef4_nic *efx)
ef4_oword_t reg;
int link_speed, isolate;
isolate = !!ACCESS_ONCE(efx->reset_pending);
isolate = !!READ_ONCE(efx->reset_pending);
switch (link_state->speed) {
case 10000: link_speed = 3; break;

8
drivers/net/ethernet/sfc/falcon/farch.c
View File

@@ -834,7 +834,7 @@ ef4_farch_handle_tx_event(struct ef4_channel *channel, ef4_qword_t *event)
struct ef4_nic *efx = channel->efx;
int tx_packets = 0;
if (unlikely(ACCESS_ONCE(efx->reset_pending)))
if (unlikely(READ_ONCE(efx->reset_pending)))
return 0;
if (likely(EF4_QWORD_FIELD(*event, FSF_AZ_TX_EV_COMP))) {
@@ -990,7 +990,7 @@ ef4_farch_handle_rx_event(struct ef4_channel *channel, const ef4_qword_t *event)
struct ef4_rx_queue *rx_queue;
struct ef4_nic *efx = channel->efx;
if (unlikely(ACCESS_ONCE(efx->reset_pending)))
if (unlikely(READ_ONCE(efx->reset_pending)))
return;
rx_ev_cont = EF4_QWORD_FIELD(*event, FSF_AZ_RX_EV_JUMBO_CONT);
@@ -1504,7 +1504,7 @@ irqreturn_t ef4_farch_fatal_interrupt(struct ef4_nic *efx)
irqreturn_t ef4_farch_legacy_interrupt(int irq, void *dev_id)
{
struct ef4_nic *efx = dev_id;
bool soft_enabled = ACCESS_ONCE(efx->irq_soft_enabled);
bool soft_enabled = READ_ONCE(efx->irq_soft_enabled);
ef4_oword_t *int_ker = efx->irq_status.addr;
irqreturn_t result = IRQ_NONE;
struct ef4_channel *channel;
@@ -1596,7 +1596,7 @@ irqreturn_t ef4_farch_msi_interrupt(int irq, void *dev_id)
"IRQ %d on CPU %d status " EF4_OWORD_FMT "\n",
irq, raw_smp_processor_id(), EF4_OWORD_VAL(*int_ker));
if (!likely(ACCESS_ONCE(efx->irq_soft_enabled)))
if (!likely(READ_ONCE(efx->irq_soft_enabled)))
return IRQ_HANDLED;
/* Handle non-event-queue sources */

6
drivers/net/ethernet/sfc/falcon/nic.h
View File

@@ -83,7 +83,7 @@ static inline struct ef4_tx_queue *ef4_tx_queue_partner(struct ef4_tx_queue *tx_
static inline bool __ef4_nic_tx_is_empty(struct ef4_tx_queue *tx_queue,
unsigned int write_count)
{
unsigned int empty_read_count = ACCESS_ONCE(tx_queue->empty_read_count);
unsigned int empty_read_count = READ_ONCE(tx_queue->empty_read_count);
if (empty_read_count == 0)
return false;
@@ -464,11 +464,11 @@ irqreturn_t ef4_farch_fatal_interrupt(struct ef4_nic *efx);
static inline int ef4_nic_event_test_irq_cpu(struct ef4_channel *channel)
{
return ACCESS_ONCE(channel->event_test_cpu);
return READ_ONCE(channel->event_test_cpu);
}
static inline int ef4_nic_irq_test_irq_cpu(struct ef4_nic *efx)
{
return ACCESS_ONCE(efx->last_irq_cpu);
return READ_ONCE(efx->last_irq_cpu);
}
/* Global Resources */

6
drivers/net/ethernet/sfc/falcon/tx.c
View File

@@ -134,8 +134,8 @@ static void ef4_tx_maybe_stop_queue(struct ef4_tx_queue *txq1)
*/
netif_tx_stop_queue(txq1->core_txq);
smp_mb();
txq1->old_read_count = ACCESS_ONCE(txq1->read_count);
txq2->old_read_count = ACCESS_ONCE(txq2->read_count);
txq1->old_read_count = READ_ONCE(txq1->read_count);
txq2->old_read_count = READ_ONCE(txq2->read_count);
fill_level = max(txq1->insert_count - txq1->old_read_count,
txq2->insert_count - txq2->old_read_count);
@@ -524,7 +524,7 @@ void ef4_xmit_done(struct ef4_tx_queue *tx_queue, unsigned int index)
/* Check whether the hardware queue is now empty */
if ((int)(tx_queue->read_count - tx_queue->old_write_count) >= 0) {
tx_queue->old_write_count = ACCESS_ONCE(tx_queue->write_count);
tx_queue->old_write_count = READ_ONCE(tx_queue->write_count);
if (tx_queue->read_count == tx_queue->old_write_count) {
smp_mb();
tx_queue->empty_read_count =