ARM: barrier: allow options to be passed to memory barrier instructions
On ARMv7, the memory barrier instructions take an optional `option'
field which can be used to constrain the effects of a memory barrier
based on shareability and access type.
This patch allows the caller to pass these options if required, and
updates the smp_*() barriers to request inner-shareable barriers,
affecting only stores for the _wmb variant. wmb() is also changed to
use the -st version of dsb.
Reported-by: Albin Tonnerre <albin.tonnerre@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index a5fef71..fcc1b5b 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -220,9 +220,9 @@
#ifdef CONFIG_SMP
#if __LINUX_ARM_ARCH__ >= 7
.ifeqs "\mode","arm"
- ALT_SMP(dmb)
+ ALT_SMP(dmb ish)
.else
- ALT_SMP(W(dmb))
+ ALT_SMP(W(dmb) ish)
.endif
#elif __LINUX_ARM_ARCH__ == 6
ALT_SMP(mcr p15, 0, r0, c7, c10, 5) @ dmb
