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/infiniband/hw/hfi1/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c
index d9a1e98..97bea2e 100644
--- a/drivers/infiniband/hw/hfi1/file_ops.c
+++ b/drivers/infiniband/hw/hfi1/file_ops.c
@@ -380,7 +380,7 @@ static long hfi1_file_ioctl(struct file *fp, unsigned int cmd,
if (sc->flags & SCF_FROZEN) {
wait_event_interruptible_timeout(
dd->event_queue,
- !(ACCESS_ONCE(dd->flags) & HFI1_FROZEN),
+ !(READ_ONCE(dd->flags) & HFI1_FROZEN),
msecs_to_jiffies(SEND_CTXT_HALT_TIMEOUT));
if (dd->flags & HFI1_FROZEN)
return -ENOLCK;
diff --git a/drivers/infiniband/hw/hfi1/pio.c b/drivers/infiniband/hw/hfi1/pio.c
index 7108a4b..75e7407 100644
--- a/drivers/infiniband/hw/hfi1/pio.c
+++ b/drivers/infiniband/hw/hfi1/pio.c
@@ -1423,14 +1423,14 @@ struct pio_buf *sc_buffer_alloc(struct send_context *sc, u32 dw_len,
goto done;
}
/* copy from receiver cache line and recalculate */
- sc->alloc_free = ACCESS_ONCE(sc->free);
+ sc->alloc_free = READ_ONCE(sc->free);
avail =
(unsigned long)sc->credits -
(sc->fill - sc->alloc_free);
if (blocks > avail) {
/* still no room, actively update */
sc_release_update(sc);
- sc->alloc_free = ACCESS_ONCE(sc->free);
+ sc->alloc_free = READ_ONCE(sc->free);
trycount++;
goto retry;
}
@@ -1667,7 +1667,7 @@ void sc_release_update(struct send_context *sc)
/* call sent buffer callbacks */
code = -1; /* code not yet set */
- head = ACCESS_ONCE(sc->sr_head); /* snapshot the head */
+ head = READ_ONCE(sc->sr_head); /* snapshot the head */
tail = sc->sr_tail;
while (head != tail) {
pbuf = &sc->sr[tail].pbuf;
diff --git a/drivers/infiniband/hw/hfi1/ruc.c b/drivers/infiniband/hw/hfi1/ruc.c
index b3291f0..a7fc664 100644
--- a/drivers/infiniband/hw/hfi1/ruc.c
+++ b/drivers/infiniband/hw/hfi1/ruc.c
@@ -363,7 +363,7 @@ static void ruc_loopback(struct rvt_qp *sqp)
again:
smp_read_barrier_depends(); /* see post_one_send() */
- if (sqp->s_last == ACCESS_ONCE(sqp->s_head))
+ if (sqp->s_last == READ_ONCE(sqp->s_head))
goto clr_busy;
wqe = rvt_get_swqe_ptr(sqp, sqp->s_last);
diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c
index 6781bcd..08346d2 100644
--- a/drivers/infiniband/hw/hfi1/sdma.c
+++ b/drivers/infiniband/hw/hfi1/sdma.c
@@ -1725,7 +1725,7 @@ static inline u16 sdma_gethead(struct sdma_engine *sde)
swhead = sde->descq_head & sde->sdma_mask;
/* this code is really bad for cache line trading */
- swtail = ACCESS_ONCE(sde->descq_tail) & sde->sdma_mask;
+ swtail = READ_ONCE(sde->descq_tail) & sde->sdma_mask;
cnt = sde->descq_cnt;
if (swhead < swtail)
@@ -1872,7 +1872,7 @@ static void sdma_make_progress(struct sdma_engine *sde, u64 status)
if ((status & sde->idle_mask) && !idle_check_done) {
u16 swtail;
- swtail = ACCESS_ONCE(sde->descq_tail) & sde->sdma_mask;
+ swtail = READ_ONCE(sde->descq_tail) & sde->sdma_mask;
if (swtail != hwhead) {
hwhead = (u16)read_sde_csr(sde, SD(HEAD));
idle_check_done = 1;
@@ -2222,7 +2222,7 @@ void sdma_seqfile_dump_sde(struct seq_file *s, struct sdma_engine *sde)
u16 len;
head = sde->descq_head & sde->sdma_mask;
- tail = ACCESS_ONCE(sde->descq_tail) & sde->sdma_mask;
+ tail = READ_ONCE(sde->descq_tail) & sde->sdma_mask;
seq_printf(s, SDE_FMT, sde->this_idx,
sde->cpu,
sdma_state_name(sde->state.current_state),
@@ -3305,7 +3305,7 @@ int sdma_ahg_alloc(struct sdma_engine *sde)
return -EINVAL;
}
while (1) {
- nr = ffz(ACCESS_ONCE(sde->ahg_bits));
+ nr = ffz(READ_ONCE(sde->ahg_bits));
if (nr > 31) {
trace_hfi1_ahg_allocate(sde, -ENOSPC);
return -ENOSPC;
diff --git a/drivers/infiniband/hw/hfi1/sdma.h b/drivers/infiniband/hw/hfi1/sdma.h
index 107011d..374c597 100644
--- a/drivers/infiniband/hw/hfi1/sdma.h
+++ b/drivers/infiniband/hw/hfi1/sdma.h
@@ -445,7 +445,7 @@ static inline u16 sdma_descq_freecnt(struct sdma_engine *sde)
{
return sde->descq_cnt -
(sde->descq_tail -
- ACCESS_ONCE(sde->descq_head)) - 1;
+ READ_ONCE(sde->descq_head)) - 1;
}
static inline u16 sdma_descq_inprocess(struct sdma_engine *sde)
diff --git a/drivers/infiniband/hw/hfi1/uc.c b/drivers/infiniband/hw/hfi1/uc.c
index 0b64617..9a31c58 100644
--- a/drivers/infiniband/hw/hfi1/uc.c
+++ b/drivers/infiniband/hw/hfi1/uc.c
@@ -80,7 +80,7 @@ int hfi1_make_uc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
goto bail;
/* We are in the error state, flush the work request. */
smp_read_barrier_depends(); /* see post_one_send() */
- if (qp->s_last == ACCESS_ONCE(qp->s_head))
+ if (qp->s_last == READ_ONCE(qp->s_head))
goto bail;
/* If DMAs are in progress, we can't flush immediately. */
if (iowait_sdma_pending(&priv->s_iowait)) {
@@ -121,7 +121,7 @@ int hfi1_make_uc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
goto bail;
/* Check if send work queue is empty. */
smp_read_barrier_depends(); /* see post_one_send() */
- if (qp->s_cur == ACCESS_ONCE(qp->s_head)) {
+ if (qp->s_cur == READ_ONCE(qp->s_head)) {
clear_ahg(qp);
goto bail;
}
diff --git a/drivers/infiniband/hw/hfi1/ud.c b/drivers/infiniband/hw/hfi1/ud.c
index 2ba74fd..7fec6b9 100644
--- a/drivers/infiniband/hw/hfi1/ud.c
+++ b/drivers/infiniband/hw/hfi1/ud.c
@@ -487,7 +487,7 @@ int hfi1_make_ud_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
goto bail;
/* We are in the error state, flush the work request. */
smp_read_barrier_depends(); /* see post_one_send */
- if (qp->s_last == ACCESS_ONCE(qp->s_head))
+ if (qp->s_last == READ_ONCE(qp->s_head))
goto bail;
/* If DMAs are in progress, we can't flush immediately. */
if (iowait_sdma_pending(&priv->s_iowait)) {
@@ -501,7 +501,7 @@ int hfi1_make_ud_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
/* see post_one_send() */
smp_read_barrier_depends();
- if (qp->s_cur == ACCESS_ONCE(qp->s_head))
+ if (qp->s_cur == READ_ONCE(qp->s_head))
goto bail;
wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
diff --git a/drivers/infiniband/hw/hfi1/user_sdma.c b/drivers/infiniband/hw/hfi1/user_sdma.c
index c0c0e04..8ec6e8a 100644
--- a/drivers/infiniband/hw/hfi1/user_sdma.c
+++ b/drivers/infiniband/hw/hfi1/user_sdma.c
@@ -276,7 +276,7 @@ int hfi1_user_sdma_free_queues(struct hfi1_filedata *fd,
/* Wait until all requests have been freed. */
wait_event_interruptible(
pq->wait,
- (ACCESS_ONCE(pq->state) == SDMA_PKT_Q_INACTIVE));
+ (READ_ONCE(pq->state) == SDMA_PKT_Q_INACTIVE));
kfree(pq->reqs);
kfree(pq->req_in_use);
kmem_cache_destroy(pq->txreq_cache);
@@ -591,7 +591,7 @@ int hfi1_user_sdma_process_request(struct hfi1_filedata *fd,
if (ret != -EBUSY) {
req->status = ret;
WRITE_ONCE(req->has_error, 1);
- if (ACCESS_ONCE(req->seqcomp) ==
+ if (READ_ONCE(req->seqcomp) ==
req->seqsubmitted - 1)
goto free_req;
return ret;
@@ -825,7 +825,7 @@ static int user_sdma_send_pkts(struct user_sdma_request *req, unsigned maxpkts)
*/
if (req->data_len) {
iovec = &req->iovs[req->iov_idx];
- if (ACCESS_ONCE(iovec->offset) == iovec->iov.iov_len) {
+ if (READ_ONCE(iovec->offset) == iovec->iov.iov_len) {
if (++req->iov_idx == req->data_iovs) {
ret = -EFAULT;
goto free_txreq;
@@ -1390,7 +1390,7 @@ static void user_sdma_txreq_cb(struct sdma_txreq *txreq, int status)
} else {
if (status != SDMA_TXREQ_S_OK)
req->status = status;
- if (req->seqcomp == (ACCESS_ONCE(req->seqsubmitted) - 1) &&
+ if (req->seqcomp == (READ_ONCE(req->seqsubmitted) - 1) &&
(READ_ONCE(req->done) ||
READ_ONCE(req->has_error))) {
user_sdma_free_request(req, false);
diff --git a/drivers/infiniband/hw/qib/qib_ruc.c b/drivers/infiniband/hw/qib/qib_ruc.c
index 53efbb0..9a37e84 100644
--- a/drivers/infiniband/hw/qib/qib_ruc.c
+++ b/drivers/infiniband/hw/qib/qib_ruc.c
@@ -368,7 +368,7 @@ static void qib_ruc_loopback(struct rvt_qp *sqp)
again:
smp_read_barrier_depends(); /* see post_one_send() */
- if (sqp->s_last == ACCESS_ONCE(sqp->s_head))
+ if (sqp->s_last == READ_ONCE(sqp->s_head))
goto clr_busy;
wqe = rvt_get_swqe_ptr(sqp, sqp->s_last);
diff --git a/drivers/infiniband/hw/qib/qib_uc.c b/drivers/infiniband/hw/qib/qib_uc.c
index 498e220..bddcc37 100644
--- a/drivers/infiniband/hw/qib/qib_uc.c
+++ b/drivers/infiniband/hw/qib/qib_uc.c
@@ -61,7 +61,7 @@ int qib_make_uc_req(struct rvt_qp *qp, unsigned long *flags)
goto bail;
/* We are in the error state, flush the work request. */
smp_read_barrier_depends(); /* see post_one_send() */
- if (qp->s_last == ACCESS_ONCE(qp->s_head))
+ if (qp->s_last == READ_ONCE(qp->s_head))
goto bail;
/* If DMAs are in progress, we can't flush immediately. */
if (atomic_read(&priv->s_dma_busy)) {
@@ -91,7 +91,7 @@ int qib_make_uc_req(struct rvt_qp *qp, unsigned long *flags)
goto bail;
/* Check if send work queue is empty. */
smp_read_barrier_depends(); /* see post_one_send() */
- if (qp->s_cur == ACCESS_ONCE(qp->s_head))
+ if (qp->s_cur == READ_ONCE(qp->s_head))
goto bail;
/*
* Start a new request.
diff --git a/drivers/infiniband/hw/qib/qib_ud.c b/drivers/infiniband/hw/qib/qib_ud.c
index be49074..15962ed 100644
--- a/drivers/infiniband/hw/qib/qib_ud.c
+++ b/drivers/infiniband/hw/qib/qib_ud.c
@@ -253,7 +253,7 @@ int qib_make_ud_req(struct rvt_qp *qp, unsigned long *flags)
goto bail;
/* We are in the error state, flush the work request. */
smp_read_barrier_depends(); /* see post_one_send */
- if (qp->s_last == ACCESS_ONCE(qp->s_head))
+ if (qp->s_last == READ_ONCE(qp->s_head))
goto bail;
/* If DMAs are in progress, we can't flush immediately. */
if (atomic_read(&priv->s_dma_busy)) {
@@ -267,7 +267,7 @@ int qib_make_ud_req(struct rvt_qp *qp, unsigned long *flags)
/* see post_one_send() */
smp_read_barrier_depends();
- if (qp->s_cur == ACCESS_ONCE(qp->s_head))
+ if (qp->s_cur == READ_ONCE(qp->s_head))
goto bail;
wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c
index 22df09a..b670cb9 100644
--- a/drivers/infiniband/sw/rdmavt/qp.c
+++ b/drivers/infiniband/sw/rdmavt/qp.c
@@ -1073,7 +1073,7 @@ int rvt_error_qp(struct rvt_qp *qp, enum ib_wc_status err)
rdi->driver_f.notify_error_qp(qp);
/* Schedule the sending tasklet to drain the send work queue. */
- if (ACCESS_ONCE(qp->s_last) != qp->s_head)
+ if (READ_ONCE(qp->s_last) != qp->s_head)
rdi->driver_f.schedule_send(qp);
rvt_clear_mr_refs(qp, 0);
@@ -1686,7 +1686,7 @@ static inline int rvt_qp_is_avail(
if (likely(qp->s_avail))
return 0;
smp_read_barrier_depends(); /* see rc.c */
- slast = ACCESS_ONCE(qp->s_last);
+ slast = READ_ONCE(qp->s_last);
if (qp->s_head >= slast)
avail = qp->s_size - (qp->s_head - slast);
else
@@ -1917,7 +1917,7 @@ int rvt_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
* ahead and kick the send engine into gear. Otherwise we will always
* just schedule the send to happen later.
*/
- call_send = qp->s_head == ACCESS_ONCE(qp->s_last) && !wr->next;
+ call_send = qp->s_head == READ_ONCE(qp->s_last) && !wr->next;
for (; wr; wr = wr->next) {
err = rvt_post_one_wr(qp, wr, &call_send);