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/wireless/intel/iwlwifi/mvm/ops.c b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
index 2318789..0f45f34 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
@@ -1118,7 +1118,7 @@ void iwl_mvm_set_hw_ctkill_state(struct iwl_mvm *mvm, bool state)
static bool iwl_mvm_set_hw_rfkill_state(struct iwl_op_mode *op_mode, bool state)
{
struct iwl_mvm *mvm = IWL_OP_MODE_GET_MVM(op_mode);
- bool calibrating = ACCESS_ONCE(mvm->calibrating);
+ bool calibrating = READ_ONCE(mvm->calibrating);
if (state)
set_bit(IWL_MVM_STATUS_HW_RFKILL, &mvm->status);
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
index 6f2e2af..6e9d3289 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
@@ -652,7 +652,7 @@ int iwl_mvm_tx_skb_non_sta(struct iwl_mvm *mvm, struct sk_buff *skb)
return -1;
} else if (info.control.vif->type == NL80211_IFTYPE_STATION &&
is_multicast_ether_addr(hdr->addr1)) {
- u8 ap_sta_id = ACCESS_ONCE(mvmvif->ap_sta_id);
+ u8 ap_sta_id = READ_ONCE(mvmvif->ap_sta_id);
if (ap_sta_id != IWL_MVM_INVALID_STA)
sta_id = ap_sta_id;
@@ -700,7 +700,7 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb,
snap_ip_tcp = 8 + skb_transport_header(skb) - skb_network_header(skb) +
tcp_hdrlen(skb);
- dbg_max_amsdu_len = ACCESS_ONCE(mvm->max_amsdu_len);
+ dbg_max_amsdu_len = READ_ONCE(mvm->max_amsdu_len);
if (!sta->max_amsdu_len ||
!ieee80211_is_data_qos(hdr->frame_control) ||
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
index a06b661..f25ce3a 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
@@ -1247,7 +1247,7 @@ static void iwl_pcie_rx_handle(struct iwl_trans *trans, int queue)
spin_lock(&rxq->lock);
/* uCode's read index (stored in shared DRAM) indicates the last Rx
* buffer that the driver may process (last buffer filled by ucode). */
- r = le16_to_cpu(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF;
+ r = le16_to_cpu(READ_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF;
i = rxq->read;
/* W/A 9000 device step A0 wrap-around bug */
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index 2e3e013..9ad3f4f 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
@@ -2076,12 +2076,12 @@ static int iwl_trans_pcie_wait_txq_empty(struct iwl_trans *trans, int txq_idx)
IWL_DEBUG_TX_QUEUES(trans, "Emptying queue %d...\n", txq_idx);
txq = trans_pcie->txq[txq_idx];
- wr_ptr = ACCESS_ONCE(txq->write_ptr);
+ wr_ptr = READ_ONCE(txq->write_ptr);
- while (txq->read_ptr != ACCESS_ONCE(txq->write_ptr) &&
+ while (txq->read_ptr != READ_ONCE(txq->write_ptr) &&
!time_after(jiffies,
now + msecs_to_jiffies(IWL_FLUSH_WAIT_MS))) {
- u8 write_ptr = ACCESS_ONCE(txq->write_ptr);
+ u8 write_ptr = READ_ONCE(txq->write_ptr);
if (WARN_ONCE(wr_ptr != write_ptr,
"WR pointer moved while flushing %d -> %d\n",
@@ -2553,7 +2553,7 @@ static u32 iwl_trans_pcie_dump_rbs(struct iwl_trans *trans,
spin_lock(&rxq->lock);
- r = le16_to_cpu(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF;
+ r = le16_to_cpu(READ_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF;
for (i = rxq->read, j = 0;
i != r && j < allocated_rb_nums;
@@ -2814,7 +2814,7 @@ static struct iwl_trans_dump_data
/* Dump RBs is supported only for pre-9000 devices (1 queue) */
struct iwl_rxq *rxq = &trans_pcie->rxq[0];
/* RBs */
- num_rbs = le16_to_cpu(ACCESS_ONCE(rxq->rb_stts->closed_rb_num))
+ num_rbs = le16_to_cpu(READ_ONCE(rxq->rb_stts->closed_rb_num))
& 0x0FFF;
num_rbs = (num_rbs - rxq->read) & RX_QUEUE_MASK;
len += num_rbs * (sizeof(*data) +