arm64: barriers: add dmb barrier
Commit 8adbf57fc429 ("irqchip: gic: use dmb ishst instead of dsb when
raising a softirq") added an explicit dmb(...) call to the GIC driver.
This patch adds a simple dmb() macro to arm64, which expands to a DMB SY
instruction.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
index 409ca37..66eb764 100644
--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h
@@ -25,6 +25,7 @@
#define wfi() asm volatile("wfi" : : : "memory")
#define isb() asm volatile("isb" : : : "memory")
+#define dmb(opt) asm volatile("dmb sy" : : : "memory")
#define dsb(opt) asm volatile("dsb sy" : : : "memory")
#define mb() dsb()