Messages in this thread | | | Subject | Re: [PATCH] vfio: Fix endianness handling for emulated BARs | From | Benjamin Herrenschmidt <> | Date | Wed, 25 Jun 2014 07:54:37 +1000 |
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On Wed, 2014-06-25 at 00:33 +1000, Alexey Kardashevskiy wrote: > > I do not understand why @val is considered LE here and need to be > converted > to CPU. Really. I truly believe it should be cpu_to_le32().
No. Both are slightly wrong semantically but le32_to_cpu() is less wrong :-)
iowrite32 supposedly takes a "cpu" value as argument and writes an "le" value. So if anything, you need something that converts to a "cpu" value before you call iowrite32.
Now it's still slightly wrong because the "input" to le32_to_cpu() is supposed to be an "LE" value but of course here it's not, it's a "cpu" value too :-)
But yes, I agree with aw here, either do nothing or stick a set of iowriteXX_native or something equivalent in the generic iomap header, define them in term of iowrite32be/iowrite32 based on the compile time endian of the arch.
Hitting asm-generic/iomap.h I think will cover all archs except ARM. For ARM, just hack arch/arm/asm/io.h
Cheers, Ben.
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