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authorSinan Kaya <okaya@codeaurora.org>2018-04-03 08:55:03 -0400
committerJames Hogan <jhogan@kernel.org>2018-04-12 23:01:58 +0100
commitf6b7aeee8f167409195fbf1364d02988fecad1d0 (patch)
treefd7a5652e201f2a401ffdf57973f2e100a507fb1 /arch/mips
parenta5075e6226c42a8e64ea1b862eec7747dc46cb32 (diff)
downloadlinux-0-day-f6b7aeee8f167409195fbf1364d02988fecad1d0.tar.gz
linux-0-day-f6b7aeee8f167409195fbf1364d02988fecad1d0.tar.xz
MIPS: io: Prevent compiler reordering writeX()
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@codeaurora.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/18997/ [jhogan@kernel.org: Tidy commit message] Signed-off-by: James Hogan <jhogan@kernel.org>
Diffstat (limited to 'arch/mips')
-rw-r--r--arch/mips/include/asm/io.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 0cbf3af37ecad..fd00ddafb425e 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -307,7 +307,7 @@ static inline void iounmap(const volatile void __iomem *addr)
#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) \