Re: [PATCH v7 05/19] intel/VPMU: Clean up Intel VPMU code

["Jan Beulich" <JBeulich@suse.com>]

>>> On 06.06.14 at 20:34, <andrew.cooper3@citrix.com> wrote:
> On 06/06/14 18:40, Boris Ostrovsky wrote:
>> -static int arch_pmc_cnt;
>> +    eax = cpuid_eax(0xa);
>> +    return ( (eax & PMU_GENERAL_NR_MASK) >> PMU_GENERAL_NR_SHIFT );
>> +}
> 
> This (and later) can be made much simpler.  The style guidelines easily
> permit:
> 
> static int core2_get_arch_pmc_count(void)
> {
>     return (cpuid_eax(0xa) & PMU_GENERAL_NR_MASK) >> PMU_GENERAL_NR_SHIFT;
> }

The above can be further simplified using MASK_EXTR(), at once
eliminating the need for *_SHIFT constants. 

> Unrelated to this code itself, I wonder whether Xen should gain some
> mnemonics for cpuid leaves.

We already have XSTATE_CPUID, so it would indeed seem desirable
to name 0xa too.

Jan