Commit e511267b authored by Robin Murphy's avatar Robin Murphy Committed by Will Deacon
Browse files

io-64-nonatomic: Add relaxed accessor variants 



Whilst commit 9439eb3a ("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 <hch@lst.de>
CC: Darren Hart <dvhart@linux.intel.com>
CC: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent f0cfffc4

include/asm-generic/io.h

+2 −2
Original line number Diff line number Diff line
@@ -191,7 +191,7 @@ static inline void writeq(u64 value, volatile void __iomem *addr) 
#define readl_relaxed readl

#endif



#ifndef readq_relaxed

#if defined(readq) && !defined(readq_relaxed)

#define readq_relaxed readq

#endif
@@ -207,7 +207,7 @@ static inline void writeq(u64 value, volatile void __iomem *addr) 
#define writel_relaxed writel

#endif



#ifndef writeq_relaxed

#if defined(writeq) && !defined(writeq_relaxed)

#define writeq_relaxed writeq

#endif

include/linux/io-64-nonatomic-hi-lo.h

+25 −0
Original line number Diff line number Diff line
@@ -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_ */

include/linux/io-64-nonatomic-lo-hi.h

+25 −0
Original line number Diff line number Diff line
@@ -21,6 +21,23 @@ static inline void lo_hi_writeq(__u64 val, volatile void __iomem *addr) 
	writel(val >> 32, addr + 4);

}



static inline __u64 lo_hi_readq_relaxed(const volatile void __iomem *addr)

{

	const volatile u32 __iomem *p = addr;

	u32 low, high;



	low = readl_relaxed(p);

	high = readl_relaxed(p + 1);



	return low + ((u64)high << 32);

}



static inline void lo_hi_writeq_relaxed(__u64 val, volatile void __iomem *addr)

{

	writel_relaxed(val, addr);

	writel_relaxed(val >> 32, addr + 4);

}



#ifndef readq

#define readq lo_hi_readq

#endif
@@ -29,4 +46,12 @@ static inline void lo_hi_writeq(__u64 val, volatile void __iomem *addr) 
#define writeq lo_hi_writeq

#endif



#ifndef readq_relaxed

#define readq_relaxed lo_hi_readq_relaxed

#endif



#ifndef writeq_relaxed

#define writeq_relaxed lo_hi_writeq_relaxed

#endif



#endif	/* _LINUX_IO_64_NONATOMIC_LO_HI_H_ */

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