Re: [PATCH] x86, AMD: Correct F15h IC aliasing issue

[Borislav Petkov <bp@amd64.org>]

On Wed, Jul 27, 2011 at 01:16:04PM -0400, H. Peter Anvin wrote:
> > + * Create a contiguous bitmask starting at bit position @lo and ending at
> > + * position @hi. For example
> > + *
> > + * GENMASK_ULL(21, 39) gives us the 64bit vector 0x000000ffffe00000.
> > + */
> > +#define _GENMASK_T(cast, type, lo, hi) \
> > +       (((cast)(1##type << ((hi) - (lo) + 1)) - 1) << (lo))
> > +#define GENMASK(lo, hi)                _GENMASK_T(unsigned, U, lo, hi)
> > +#define GENMASK_UL(lo, hi)     _GENMASK_T(unsigned long, UL, lo, hi)
> > +#define GENMASK_ULL(lo, hi)    _GENMASK_T(unsigned long long, ULL, lo, hi)
> > +
> 
> These really need to be usable from assembly language, too (in which
> case you of course need to not have the cast and suffix), so it probably
> should be defined in <linux/const.h> with the other constant macros.

How about that:

#define _GENMASK_T(cast, type, lo, hi) \
	        ((_AT(cast, (_AC(1,type) << ((hi) - (lo) + 1))) - 1) << (lo))
#define GENMASK(lo, hi)         _GENMASK_T(unsigned, U, lo, hi)
#define GENMASK_UL(lo, hi)      _GENMASK_T(unsigned long, UL, lo, hi)
#define GENMASK_ULL(lo, hi)     _GENMASK_T(unsigned long long, ULL, lo, hi)

outside of __KERNEL__ scope?


-- 
Regards/Gruss,
Boris.

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