linux/tools/arch
Mark Rutland 6aa7de0591 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>
2017-10-25 11:01:08 +02:00
..
alpha/include tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
arc/include/uapi/asm tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
arm/include tools headers: Sync kernel ABI headers with tooling headers 2017-07-31 10:35:28 -03:00
arm64/include tools headers: Sync kernel ABI headers with tooling headers 2017-07-31 10:35:28 -03:00
frv/include/uapi/asm tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
h8300/include tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
hexagon/include/uapi/asm tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
ia64/include tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
m32r/include/uapi/asm tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
microblaze/include/uapi/asm tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
mips/include tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
mn10300/include/uapi/asm tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
parisc/include/uapi/asm parisc: Add MADV_HWPOISON and MADV_SOFT_OFFLINE 2017-08-22 16:34:33 +02:00
powerpc/include tools headers: Sync kernel ABI headers with tooling headers 2017-07-31 10:35:28 -03:00
s390/include tools include: Sync kernel ABI headers with tooling headers 2017-09-25 10:39:44 -03:00
score/include/uapi/asm tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
sh/include tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
sparc/include tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
tile/include tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00
x86 locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:08 +02:00
xtensa/include tools include: Add mman macros needed by perf for all arch 2016-09-19 11:30:56 -03:00