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>
diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index 13f72f5..a95a46b 100644
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -2073,7 +2073,7 @@
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_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 @@
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 @@
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 @@
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);
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index b9cb697..016616a 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -2809,7 +2809,7 @@
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_MC_BIST)
@@ -2874,7 +2874,7 @@
/* 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;
/* efx_process_channel() will no longer read events once a
diff --git a/drivers/net/ethernet/sfc/falcon/efx.c b/drivers/net/ethernet/sfc/falcon/efx.c
index 29614da..7263275 100644
--- a/drivers/net/ethernet/sfc/falcon/efx.c
+++ b/drivers/net/ethernet/sfc/falcon/efx.c
@@ -2545,7 +2545,7 @@
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 @@
/* 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);
diff --git a/drivers/net/ethernet/sfc/falcon/falcon.c b/drivers/net/ethernet/sfc/falcon/falcon.c
index 93c713c..cd8bb47 100644
--- a/drivers/net/ethernet/sfc/falcon/falcon.c
+++ b/drivers/net/ethernet/sfc/falcon/falcon.c
@@ -452,7 +452,7 @@
"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 @@
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;
diff --git a/drivers/net/ethernet/sfc/falcon/farch.c b/drivers/net/ethernet/sfc/falcon/farch.c
index 05916c7..494884f 100644
--- a/drivers/net/ethernet/sfc/falcon/farch.c
+++ b/drivers/net/ethernet/sfc/falcon/farch.c
@@ -834,7 +834,7 @@
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 @@
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_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 @@
"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 */
diff --git a/drivers/net/ethernet/sfc/falcon/nic.h b/drivers/net/ethernet/sfc/falcon/nic.h
index a4c4592..54ca457c 100644
--- a/drivers/net/ethernet/sfc/falcon/nic.h
+++ b/drivers/net/ethernet/sfc/falcon/nic.h
@@ -83,7 +83,7 @@
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 @@
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 */
diff --git a/drivers/net/ethernet/sfc/falcon/tx.c b/drivers/net/ethernet/sfc/falcon/tx.c
index 6a75f41..6486814 100644
--- a/drivers/net/ethernet/sfc/falcon/tx.c
+++ b/drivers/net/ethernet/sfc/falcon/tx.c
@@ -134,8 +134,8 @@
*/
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 @@
/* 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 =
diff --git a/drivers/net/ethernet/sfc/farch.c b/drivers/net/ethernet/sfc/farch.c
index ba45150..86454d2 100644
--- a/drivers/net/ethernet/sfc/farch.c
+++ b/drivers/net/ethernet/sfc/farch.c
@@ -827,7 +827,7 @@
struct efx_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(EFX_QWORD_FIELD(*event, FSF_AZ_TX_EV_COMP))) {
@@ -979,7 +979,7 @@
struct efx_rx_queue *rx_queue;
struct efx_nic *efx = channel->efx;
- if (unlikely(ACCESS_ONCE(efx->reset_pending)))
+ if (unlikely(READ_ONCE(efx->reset_pending)))
return;
rx_ev_cont = EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_JUMBO_CONT);
@@ -1520,7 +1520,7 @@
irqreturn_t efx_farch_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);
efx_oword_t *int_ker = efx->irq_status.addr;
irqreturn_t result = IRQ_NONE;
struct efx_channel *channel;
@@ -1612,7 +1612,7 @@
"IRQ %d on CPU %d status " EFX_OWORD_FMT "\n",
irq, raw_smp_processor_id(), EFX_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 */
diff --git a/drivers/net/ethernet/sfc/nic.h b/drivers/net/ethernet/sfc/nic.h
index 4d7fb8a..7b51b63 100644
--- a/drivers/net/ethernet/sfc/nic.h
+++ b/drivers/net/ethernet/sfc/nic.h
@@ -81,7 +81,7 @@
static inline bool __efx_nic_tx_is_empty(struct efx_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;
@@ -617,11 +617,11 @@
static inline int efx_nic_event_test_irq_cpu(struct efx_channel *channel)
{
- return ACCESS_ONCE(channel->event_test_cpu);
+ return READ_ONCE(channel->event_test_cpu);
}
static inline int efx_nic_irq_test_irq_cpu(struct efx_nic *efx)
{
- return ACCESS_ONCE(efx->last_irq_cpu);
+ return READ_ONCE(efx->last_irq_cpu);
}
/* Global Resources */
diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index 60cdb97..56c2db3 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -658,7 +658,7 @@
/* Write host time for specified period or until MC is done */
while ((timespec64_compare(&now.ts_real, &limit) < 0) &&
- ACCESS_ONCE(*mc_running)) {
+ READ_ONCE(*mc_running)) {
struct timespec64 update_time;
unsigned int host_time;
@@ -668,7 +668,7 @@
do {
pps_get_ts(&now);
} while ((timespec64_compare(&now.ts_real, &update_time) < 0) &&
- ACCESS_ONCE(*mc_running));
+ READ_ONCE(*mc_running));
/* Synchronise NIC with single word of time only */
host_time = (now.ts_real.tv_sec << MC_NANOSECOND_BITS |
@@ -832,14 +832,14 @@
ptp->start.dma_addr);
/* Clear flag that signals MC ready */
- ACCESS_ONCE(*start) = 0;
+ WRITE_ONCE(*start, 0);
rc = efx_mcdi_rpc_start(efx, MC_CMD_PTP, synch_buf,
MC_CMD_PTP_IN_SYNCHRONIZE_LEN);
EFX_WARN_ON_ONCE_PARANOID(rc);
/* Wait for start from MCDI (or timeout) */
timeout = jiffies + msecs_to_jiffies(MAX_SYNCHRONISE_WAIT_MS);
- while (!ACCESS_ONCE(*start) && (time_before(jiffies, timeout))) {
+ while (!READ_ONCE(*start) && (time_before(jiffies, timeout))) {
udelay(20); /* Usually start MCDI execution quickly */
loops++;
}
@@ -849,7 +849,7 @@
if (!time_before(jiffies, timeout))
++ptp->sync_timeouts;
- if (ACCESS_ONCE(*start))
+ if (READ_ONCE(*start))
efx_ptp_send_times(efx, &last_time);
/* Collect results */
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index 32bf1fe..efb66ea 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -136,8 +136,8 @@
*/
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);
@@ -752,7 +752,7 @@
/* 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 =