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authorLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>2015-06-01 17:09:52 -0700
committerRalf Baechle <ralf@linux-mips.org>2015-06-21 21:54:30 +0200
commit6f6ed482653723e53da4a57b200348ac1eed5ce9 (patch)
tree151ad0e5c6a77a66e29c733a3e9d59fbe0c5efed /arch
parent5f93ef5cfb867aca400598f69f9ce8af14b0ced0 (diff)
MIPS: Replace smp_mb with release barrier function in unlocks.
Repleace smp_mb() in arch_write_unlock() and __clear_bit_unlock() to smp_mb__before_llsc() call which does "release" barrier functionality. It seems like it was missed in commit f252ffd50c97dae87b45f1dbad24f71358ccfbd6 during introduction of "acquire" and "release" semantics. [ralf@linux-mips: The original patch submission was labelled a fix but actually it replaces a barrier with another less restrictive type of barrier so it doesn't fix any ill behaviour but rather squeezes out a tad better performance. Further improvments will be possible once smp_release() has been merged.] Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Cc: benh@kernel.crashing.org Cc: will.deacon@arm.com Cc: linux-kernel@vger.kernel.org Cc: markos.chandras@imgtec.com Cc: macro@linux-mips.org Cc: Steven.Hill@imgtec.com Cc: alexander.h.duyck@redhat.com Cc: davem@davemloft.net Patchwork: https://patchwork.linux-mips.org/patch/10507/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/include/asm/bitops.h2
-rw-r--r--arch/mips/include/asm/spinlock.h2
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/mips/include/asm/bitops.h b/arch/mips/include/asm/bitops.h
index 0cf29bd5dc5c..ce9666cf1499 100644
--- a/arch/mips/include/asm/bitops.h
+++ b/arch/mips/include/asm/bitops.h
@@ -469,7 +469,7 @@ static inline int test_and_change_bit(unsigned long nr,
*/
static inline void __clear_bit_unlock(unsigned long nr, volatile unsigned long *addr)
{
- smp_mb();
+ smp_mb__before_llsc();
__clear_bit(nr, addr);
}
diff --git a/arch/mips/include/asm/spinlock.h b/arch/mips/include/asm/spinlock.h
index 1fca2e0793dc..7c7f3b2bd3de 100644
--- a/arch/mips/include/asm/spinlock.h
+++ b/arch/mips/include/asm/spinlock.h
@@ -317,7 +317,7 @@ static inline void arch_write_lock(arch_rwlock_t *rw)
static inline void arch_write_unlock(arch_rwlock_t *rw)
{
- smp_mb();
+ smp_mb__before_llsc();
__asm__ __volatile__(
" # arch_write_unlock \n"