The default implementation of mapping writeX() to __raw_writeX() is wrong. writeX() has stronger ordering semantics. Compiler is allowed to reorder memory writes against __raw_writeX().
Use the previously defined __io_aw() and __io_bw() macros to harden code generation according to architecture support. Signed-off-by: Sinan Kaya <[email protected]> --- include/asm-generic/io.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index d27e8af..964725e 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -208,7 +208,9 @@ static inline u64 readq(const volatile void __iomem *addr) #define writeb writeb static inline void writeb(u8 value, volatile void __iomem *addr) { + __io_bw(); __raw_writeb(value, addr); + __io_aw(); } #endif @@ -216,7 +218,9 @@ static inline void writeb(u8 value, volatile void __iomem *addr) #define writew writew static inline void writew(u16 value, volatile void __iomem *addr) { + __io_bw(); __raw_writew(cpu_to_le16(value), addr); + __io_aw(); } #endif @@ -224,7 +228,9 @@ static inline void writew(u16 value, volatile void __iomem *addr) #define writel writel static inline void writel(u32 value, volatile void __iomem *addr) { + __io_bw(); __raw_writel(__cpu_to_le32(value), addr); + __io_aw(); } #endif @@ -233,7 +239,9 @@ static inline void writel(u32 value, volatile void __iomem *addr) #define writeq writeq static inline void writeq(u64 value, volatile void __iomem *addr) { + __io_bw(); __raw_writeq(__cpu_to_le64(value), addr); + __io_aw(); } #endif #endif /* CONFIG_64BIT */ -- 2.7.4
