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Commit 16c85a1f authored Apr 30, 2013 by Catalin Marinas

arm64: Use acquire/release semantics instead of explicit DMB



This patch changes the test_and_*_bit functions to use the
load-acquire/store-release instructions instead of explicit DMB.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

parent c47d6a04

arch/arm64/lib/bitops.S

+2 −4

Original line number	Original line	Diff line number	Diff line
	@@ -46,13 +46,11 @@ ENTRY( \name )
	mov x2, #1		mov x2, #1
	add x1, x1, x0, lsr #3 // Get word offset		add x1, x1, x0, lsr #3 // Get word offset
	lsl x4, x2, x3 // Create mask		lsl x4, x2, x3 // Create mask
	smp_dmb ish		1: ldaxr x2, [x1]
	1: ldxr x2, [x1]
	lsr x0, x2, x3 // Save old value of bit		lsr x0, x2, x3 // Save old value of bit
	\instr x2, x2, x4 // toggle bit		\instr x2, x2, x4 // toggle bit
	stxr w5, x2, [x1]		stlxr w5, x2, [x1]
	cbnz w5, 1b		cbnz w5, 1b
	smp_dmb ish
	and x0, x0, #1		and x0, x0, #1
	3: ret		3: ret
	ENDPROC(\name )		ENDPROC(\name )