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| author | Will Deacon <will.deacon@arm.com> | 2013-09-03 11:44:00 +0200 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2014-10-20 19:49:17 +0200 |
| commit | 9439eb3ab9d1ece6e4ad7baaa4a7f534f9b9dab0 (patch) | |
| tree | e0c055ab3595d0f6f865f6aa2bbb0c6d51442adb /include/asm-generic | |
| parent | Linux 3.18-rc1 (diff) | |
| download | linux-9439eb3ab9d1ece6e4ad7baaa4a7f534f9b9dab0.tar.xz linux-9439eb3ab9d1ece6e4ad7baaa4a7f534f9b9dab0.zip | |
asm-generic: io: implement relaxed accessor macros as conditional wrappers
{read,write}{b,w,l,q}_relaxed are implemented by some architectures in
order to permit memory-mapped I/O accesses with weaker barrier semantics
than the non-relaxed variants.
This patch adds wrappers to asm-generic so that drivers can rely on the
relaxed accessors being available, even if they don't always provide
weaker ordering guarantees. Since some architectures both include
asm-generic/io.h and define some relaxed accessors, the definitions here
are conditional for the time being.
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'include/asm-generic')
| -rw-r--r-- | include/asm-generic/io.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index b8fdc57a7335..fc8dc0eb203c 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -53,18 +53,27 @@ static inline u32 __raw_readl(const volatile void __iomem *addr) #endif #define readb __raw_readb +#ifndef readb_relaxed +#define readb_relaxed readb +#endif #define readw readw static inline u16 readw(const volatile void __iomem *addr) { return __le16_to_cpu(__raw_readw(addr)); } +#ifndef readw_relaxed +#define readw_relaxed readw +#endif #define readl readl static inline u32 readl(const volatile void __iomem *addr) { return __le32_to_cpu(__raw_readl(addr)); } +#ifndef readl_relaxed +#define readl_relaxed readl +#endif #ifndef __raw_writeb static inline void __raw_writeb(u8 b, volatile void __iomem *addr) @@ -88,8 +97,19 @@ static inline void __raw_writel(u32 b, volatile void __iomem *addr) #endif #define writeb __raw_writeb +#ifndef writeb_relaxed +#define writeb_relaxed writeb +#endif + #define writew(b,addr) __raw_writew(__cpu_to_le16(b),addr) +#ifndef writew_relaxed +#define writew_relaxed writew +#endif + #define writel(b,addr) __raw_writel(__cpu_to_le32(b),addr) +#ifndef writel_relaxed +#define writel_relaxed writel +#endif #ifdef CONFIG_64BIT #ifndef __raw_readq @@ -104,6 +124,9 @@ static inline u64 readq(const volatile void __iomem *addr) { return __le64_to_cpu(__raw_readq(addr)); } +#ifndef readq_relaxed +#define readq_relaxed readq +#endif #ifndef __raw_writeq static inline void __raw_writeq(u64 b, volatile void __iomem *addr) @@ -113,6 +136,9 @@ static inline void __raw_writeq(u64 b, volatile void __iomem *addr) #endif #define writeq(b, addr) __raw_writeq(__cpu_to_le64(b), addr) +#ifndef writeq_relaxed +#define writeq_relaxed writeq +#endif #endif /* CONFIG_64BIT */ #ifndef PCI_IOBASE |