Messages in this thread | | | Subject | Re: [PATCH] [POWERPC] Improve (in|out)_beXX() asm code | From | Benjamin Herrenschmidt <> | Date | Tue, 20 May 2008 18:02:18 -0400 |
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On Tue, 2008-05-20 at 16:38 -0500, Scott Wood 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 > access. It won't prevent reordering of memory reads around an I/O > read, > though, which could be a problem if the I/O read result determines > the > validity of the DMA buffer. IMHO, a memory clobber would be better.
We probably want a full "memory" clobber then...
Ben.
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