From ed59dfd9509d172e4920994ed9cbebf93b0050cc Mon Sep 17 00:00:00 2001 From: Kefeng Wang Date: Mon, 23 May 2022 19:31:25 +0800 Subject: asm-generic: Add memory barrier dma_mb() The memory barrier dma_mb() is introduced by commit a76a37777f2c ("iommu/arm-smmu-v3: Ensure queue is read after updating prod pointer"), which is used to ensure that prior (both reads and writes) accesses to memory by a CPU are ordered w.r.t. a subsequent MMIO write. Reviewed-by: Arnd Bergmann # for asm-generic Signed-off-by: Kefeng Wang Reviewed-by: Marco Elver Link: https://lore.kernel.org/r/20220523113126.171714-2-wangkefeng.wang@huawei.com Signed-off-by: Will Deacon --- include/asm-generic/barrier.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/asm-generic/barrier.h') diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h index fd7e8fbaeef1..961f4d88f9ef 100644 --- a/include/asm-generic/barrier.h +++ b/include/asm-generic/barrier.h @@ -38,6 +38,10 @@ #define wmb() do { kcsan_wmb(); __wmb(); } while (0) #endif +#ifdef __dma_mb +#define dma_mb() do { kcsan_mb(); __dma_mb(); } while (0) +#endif + #ifdef __dma_rmb #define dma_rmb() do { kcsan_rmb(); __dma_rmb(); } while (0) #endif @@ -65,6 +69,10 @@ #define wmb() mb() #endif +#ifndef dma_mb +#define dma_mb() mb() +#endif + #ifndef dma_rmb #define dma_rmb() rmb() #endif -- cgit v1.2.3