On Thu, 2011-10-06 at 15:10 +0100, David Laight wrote:
horrid...
1) I'm not sure the caller expects the buffer to be corrupted.
2) It contains a lot of memory cycles.
3) It looked from the calls that this code is copying descriptors,
so the transfer length is probably 1 or 2 words - so the loop
is inefficient.
4) ppc doesn't have a fast byteswap instruction (very new gcc might
use the byteswapping memery access for the le32_to_cpu() though),
so it would be better getting the byteswap done inside
__iowrite64_copy() - since that is probably requesting a byteswap
anyway.
OTOH I'm not at all clear about the 64bit xfers....
And it's just plain wrong anyway. You should never have to byteswap a
copy.
Ben.