Re: [PATCH] [POWERPC] Improve (in|out)_beXX() asm code

From: Scott Wood
Date: Tue May 20 2008 - 18:35:32 EST

Alan Cox wrote:
It looks like we rely on -fno-strict-aliasing to prevent reordering ordinary memory accesses (such as to DMA descriptors) past the I/O

DMA descriptors in main memory are dependant on cache behaviour anyway
and the dma_* operators should be the ones enforcing the needed behaviour.

What about memory obtained from dma_alloc_coherent()? We still need a sync and a compiler barrier. The current I/O accessors have the former, but not the latter.

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