[ofa-general] [PATCH] IB/mlx4: Use pgprot_writecombine() for BlueFlame pages

[Roland Dreier]

 > Roland, I notice in the 2.6.29 code that:
 > 1. There is a function  validate_pat_support() that should be called to
 >    make sure that pat support is available.  Should the driver call this function?
 >    (the linux-cross-referencer did not find any callers).

validate_pat_support() was removed in the upstream kernel in 75a04811
("x86: handle PAT more like other CPU features").  So no, the driver
shouldn't call it.

 > 2. What happens with non-X86 architectures? The function pgprot_writecombine() is defined
 >   only in X86 archs.

Look at include/asm-generic/pgtable.h:

#ifndef pgprot_writecombine
#define pgprot_writecombine pgprot_noncached
#endif

 - R.