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

[H. Peter Anvin]

On 07/28/2011 06:44 AM, Borislav Petkov wrote:
> 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?
> 

Then everything needs another underscore.

	-hpa


-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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