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Will Deacon ca88b6d979 arm64: spinlocks: implement smp_mb__before_spinlock() as smp_mb() commit `872c63fbf9` upstream. smp_mb__before_spinlock() is intended to upgrade a spin_lock() operation to a full barrier, such that prior stores are ordered with respect to loads and stores occuring inside the critical section. Unfortunately, the core code defines the barrier as smp_wmb(), which is insufficient to provide the required ordering guarantees when used in conjunction with our load-acquire-based spinlock implementation. This patch overrides the arm64 definition of smp_mb__before_spinlock() to map to a full smp_mb(). Cc: Peter Zijlstra <peterz@infradead.org> Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>	History 2016-11-20 01:17:24 +00:00
..
asm	arm64: spinlocks: implement smp_mb__before_spinlock() as smp_mb()	2016-11-20 01:17:24 +00:00
uapi/asm	arm64: Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO	2016-11-20 01:17:00 +00:00

Will Deacon ca88b6d979 arm64: spinlocks: implement smp_mb__before_spinlock() as smp_mb()

commit 872c63fbf9 upstream.

smp_mb__before_spinlock() is intended to upgrade a spin_lock() operation
to a full barrier, such that prior stores are ordered with respect to
loads and stores occuring inside the critical section.

Unfortunately, the core code defines the barrier as smp_wmb(), which
is insufficient to provide the required ordering guarantees when used in
conjunction with our load-acquire-based spinlock implementation.

This patch overrides the arm64 definition of smp_mb__before_spinlock()
to map to a full smp_mb().

Cc: Peter Zijlstra <peterz@infradead.org>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

History

2016-11-20 01:17:24 +00:00

asm arm64: spinlocks: implement smp_mb__before_spinlock() as smp_mb() 2016-11-20 01:17:24 +00:00

uapi/asm arm64: Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO 2016-11-20 01:17:00 +00:00