Commit abbbbc83 authored by Will Deacon's avatar Will Deacon Committed by Catalin Marinas
Browse files

asm-generic/io: Pass result of I/O accessor to __io_[p]ar() 



The inX() and readX() I/O accessors must enforce ordering against
subsequent calls to the delay() routines, so that a read-back from a
device can be used to postpone a subsequent write to the same device.

On some architectures, including arm64, this ordering can only be
achieved by creating a dependency on the value returned by the I/O
accessor operation, so we need to pass the value we read to the
__io_par() and __io_ar() macros in these cases.

Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Reported-by: default avatarAndrew Murray <andrew.murray@arm.com>
Reviewed-by: default avatarPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 3e32131a

include/asm-generic/io.h

+10 −10
Original line number Diff line number Diff line
@@ -32,9 +32,9 @@ 
/* prevent prefetching of coherent DMA data ahead of a dma-complete */

#ifndef __io_ar

#ifdef rmb

#define __io_ar()      rmb()

#define __io_ar(v)      rmb()

#else

#define __io_ar()      barrier()

#define __io_ar(v)      barrier()

#endif

#endif
@@ -65,7 +65,7 @@ 
#endif



#ifndef __io_par

#define __io_par()     __io_ar()

#define __io_par(v)     __io_ar(v)

#endif
@@ -158,7 +158,7 @@ static inline u8 readb(const volatile void __iomem *addr) 


	__io_br();

	val = __raw_readb(addr);

	__io_ar();

	__io_ar(val);

	return val;

}

#endif
@@ -171,7 +171,7 @@ static inline u16 readw(const volatile void __iomem *addr) 


	__io_br();

	val = __le16_to_cpu(__raw_readw(addr));

	__io_ar();

	__io_ar(val);

	return val;

}

#endif
@@ -184,7 +184,7 @@ static inline u32 readl(const volatile void __iomem *addr) 


	__io_br();

	val = __le32_to_cpu(__raw_readl(addr));

	__io_ar();

	__io_ar(val);

	return val;

}

#endif
@@ -198,7 +198,7 @@ static inline u64 readq(const volatile void __iomem *addr) 


	__io_br();

	val = __le64_to_cpu(__raw_readq(addr));

	__io_ar();

	__io_ar(val);

	return val;

}

#endif
@@ -471,7 +471,7 @@ static inline u8 inb(unsigned long addr) 


	__io_pbr();

	val = __raw_readb(PCI_IOBASE + addr);

	__io_par();

	__io_par(val);

	return val;

}

#endif
@@ -484,7 +484,7 @@ static inline u16 inw(unsigned long addr) 


	__io_pbr();

	val = __le16_to_cpu(__raw_readw(PCI_IOBASE + addr));

	__io_par();

	__io_par(val);

	return val;

}

#endif
@@ -497,7 +497,7 @@ static inline u32 inl(unsigned long addr) 


	__io_pbr();

	val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr));

	__io_par();

	__io_par(val);

	return val;

}

#endif

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