From e511267bc25e18926826e7cccdf7872bcbb4776a Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Tue, 26 Apr 2016 11:38:20 +0100 Subject: io-64-nonatomic: Add relaxed accessor variants Whilst commit 9439eb3ab9d1 ("asm-generic: io: implement relaxed accessor macros as conditional wrappers") makes the *_relaxed forms of I/O accessors universally available to drivers, in cases where writeq() is implemented via the io-64-nonatomic helpers, writeq_relaxed() will end up falling back to writel() regardless of whether writel_relaxed() is available (identically for s/write/read/). Add corresponding relaxed forms of the nonatomic helpers to delegate to the equivalent 32-bit accessors as appropriate. We also need to fix io.h to avoid defining default relaxed variants if the basic accessors themselves don't exist. CC: Christoph Hellwig CC: Darren Hart CC: Hitoshi Mitake Acked-by: Arnd Bergmann Signed-off-by: Robin Murphy Signed-off-by: Will Deacon --- include/linux/io-64-nonatomic-hi-lo.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'include/linux/io-64-nonatomic-hi-lo.h') diff --git a/include/linux/io-64-nonatomic-hi-lo.h b/include/linux/io-64-nonatomic-hi-lo.h index 11d7e840d913..defcc4644ce3 100644 --- a/include/linux/io-64-nonatomic-hi-lo.h +++ b/include/linux/io-64-nonatomic-hi-lo.h @@ -21,6 +21,23 @@ static inline void hi_lo_writeq(__u64 val, volatile void __iomem *addr) writel(val, addr); } +static inline __u64 hi_lo_readq_relaxed(const volatile void __iomem *addr) +{ + const volatile u32 __iomem *p = addr; + u32 low, high; + + high = readl_relaxed(p + 1); + low = readl_relaxed(p); + + return low + ((u64)high << 32); +} + +static inline void hi_lo_writeq_relaxed(__u64 val, volatile void __iomem *addr) +{ + writel_relaxed(val >> 32, addr + 4); + writel_relaxed(val, addr); +} + #ifndef readq #define readq hi_lo_readq #endif @@ -29,4 +46,12 @@ static inline void hi_lo_writeq(__u64 val, volatile void __iomem *addr) #define writeq hi_lo_writeq #endif +#ifndef readq_relaxed +#define readq_relaxed hi_lo_readq_relaxed +#endif + +#ifndef writeq_relaxed +#define writeq_relaxed hi_lo_writeq_relaxed +#endif + #endif /* _LINUX_IO_64_NONATOMIC_HI_LO_H_ */ -- cgit v1.2.3