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>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index a5fef710af32..fcc1b5bf6979 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