leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

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

Browse Source 
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: Arnd Bergmann <arnd@arndb.de>
Reported-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Will Deacon 2019-02-22 18:04:52 +00:00 committed by Catalin Marinas
parent 3e32131abc
commit abbbbc83a2
1 changed files with 10 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
include/asm-generic/io.h
View File

@ -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