[PATCH] fb.h: ARM uses __raw_{read/write}

Arnd Bergmann arnd at arndb.de
Mon Jun 13 09:37:10 EDT 2011


On Monday 13 June 2011 12:08:19 Catalin Marinas wrote:
> The change proposed by Hartley wouldn't make much difference from the
> current volatile accesses (__raw_* accessors are implemented as volatile
> on ARM).

I guess it would mainly make a difference if we get a platform where
the PCI bus window is not in the same address space as the regular
physical memory and the accessors actually need to do a computation
on the address. AFAICT, ARM does not currently have any such platform
and I would hope that it says that way.

> I think the memcpy_(from|to)io could be optimised on ARM to only add a
> barrier before or after he copying loop.

Agreed, good idea.

	Arnd



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