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author | Mark Rutland <mark.rutland@arm.com> | 2017-10-23 14:07:29 -0700 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2017-10-25 11:01:08 +0200 |
commit | 6aa7de059173a986114ac43b8f50b297a86f09a8 (patch) | |
tree | 77666afe795e022914ca26433d61686c694dc4fd /drivers/misc/mic/scif | |
parent | b03a0fe0c5e4b46dcd400d27395b124499554a71 (diff) | |
download | op-kernel-dev-6aa7de059173a986114ac43b8f50b297a86f09a8.zip op-kernel-dev-6aa7de059173a986114ac43b8f50b297a86f09a8.tar.gz |
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>
Diffstat (limited to 'drivers/misc/mic/scif')
-rw-r--r-- | drivers/misc/mic/scif/scif_rb.c | 8 | ||||
-rw-r--r-- | drivers/misc/mic/scif/scif_rma_list.c | 2 |
2 files changed, 5 insertions, 5 deletions
diff --git a/drivers/misc/mic/scif/scif_rb.c b/drivers/misc/mic/scif/scif_rb.c index 637cc46..b665757 100644 --- a/drivers/misc/mic/scif/scif_rb.c +++ b/drivers/misc/mic/scif/scif_rb.c @@ -138,7 +138,7 @@ void scif_rb_commit(struct scif_rb *rb) * the read barrier in scif_rb_count(..) */ wmb(); - ACCESS_ONCE(*rb->write_ptr) = rb->current_write_offset; + WRITE_ONCE(*rb->write_ptr, rb->current_write_offset); #ifdef CONFIG_INTEL_MIC_CARD /* * X100 Si bug: For the case where a Core is performing an EXT_WR @@ -147,7 +147,7 @@ void scif_rb_commit(struct scif_rb *rb) * This way, if ordering is violated for the Interrupt Message, it will * fall just behind the first Posted associated with the first EXT_WR. */ - ACCESS_ONCE(*rb->write_ptr) = rb->current_write_offset; + WRITE_ONCE(*rb->write_ptr, rb->current_write_offset); #endif } @@ -210,7 +210,7 @@ void scif_rb_update_read_ptr(struct scif_rb *rb) * scif_rb_space(..) */ mb(); - ACCESS_ONCE(*rb->read_ptr) = new_offset; + WRITE_ONCE(*rb->read_ptr, new_offset); #ifdef CONFIG_INTEL_MIC_CARD /* * X100 Si Bug: For the case where a Core is performing an EXT_WR @@ -219,7 +219,7 @@ void scif_rb_update_read_ptr(struct scif_rb *rb) * This way, if ordering is violated for the Interrupt Message, it will * fall just behind the first Posted associated with the first EXT_WR. */ - ACCESS_ONCE(*rb->read_ptr) = new_offset; + WRITE_ONCE(*rb->read_ptr, new_offset); #endif } diff --git a/drivers/misc/mic/scif/scif_rma_list.c b/drivers/misc/mic/scif/scif_rma_list.c index e1ef8da..a036dbb 100644 --- a/drivers/misc/mic/scif/scif_rma_list.c +++ b/drivers/misc/mic/scif/scif_rma_list.c @@ -277,7 +277,7 @@ retry: * Need to restart list traversal if there has been * an asynchronous list entry deletion. */ - if (ACCESS_ONCE(ep->rma_info.async_list_del)) + if (READ_ONCE(ep->rma_info.async_list_del)) goto retry; } mutex_unlock(&ep->rma_info.rma_lock); |