Unverified Commit 77d281b7 authored Oct 01, 2019 by Paul Burton

MIPS: atomic: Use _atomic barriers in atomic_sub_if_positive()



Use smp_mb__before_atomic() & smp_mb__after_atomic() in
atomic_sub_if_positive() rather than the equivalent
smp_mb__before_llsc() & smp_llsc_mb(). The former are more standard &
this preps us for avoiding redundant duplicate barriers on Loongson3 in
a later patch.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: linux-kernel@vger.kernel.org

parent 4d1dbfe6

arch/mips/include/asm/atomic.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -196,7 +196,7 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
		{
		int result;

		smp_mb__before_llsc();
		smp_mb__before_atomic();

		if (kernel_uses_llsc) {
		int temp;
		@@ -237,7 +237,7 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
		* another barrier here.
		*/
		if (!__SYNC_loongson3_war)
		smp_llsc_mb();
		smp_mb__after_atomic();

		return result;
		}

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