4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sinan Kaya <okaya@xxxxxxxxxxxxxx> [ Upstream commit f6b7aeee8f167409195fbf1364d02988fecad1d0 ] writeX() has strong ordering semantics with respect to memory updates. In the absence of a write barrier or a compiler barrier, the compiler can reorder register and memory update instructions. This breaks the writeX() API. Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: Paul Burton <paul.burton@xxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Patchwork: https://patchwork.linux-mips.org/patch/18997/ [jhogan@xxxxxxxxxx: Tidy commit message] Signed-off-by: James Hogan <jhogan@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/mips/include/asm/io.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/mips/include/asm/io.h +++ b/arch/mips/include/asm/io.h @@ -307,7 +307,7 @@ static inline void iounmap(const volatil #if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_LOONGSON3_ENHANCEMENT) #define war_io_reorder_wmb() wmb() #else -#define war_io_reorder_wmb() do { } while (0) +#define war_io_reorder_wmb() barrier() #endif #define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, irq) \
