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>

1 files changed, 2 insertions, 4 deletions

diff --git a/arch/arm64/lib/bitops.S b/arch/arm64/lib/bitops.S
index eaed8bbd78fc..36216d30cb9a 100644
--- a/arch/arm64/lib/bitops.S
+++ b/arch/arm64/lib/bitops.S
@@ -46,13 +46,11 @@ ENTRY(	\name	)
         mov     x2, #1
         add     x1, x1, x0, lsr #3      // Get word offset
         lsl     x4, x2, x3              // Create mask
-        smp_dmb ish
-1:      ldxr    x2, [x1]
+1:      ldaxr   x2, [x1]
         lsr     x0, x2, x3              // Save old value of bit
         \instr  x2, x2, x4              // toggle bit
-        stxr    w5, x2, [x1]
+        stlxr   w5, x2, [x1]
         cbnz    w5, 1b
-        smp_dmb ish
         and     x0, x0, #1
 3:      ret
 ENDPROC(\name   )