Re: [PATCH 2/2] amd: uncore: Get correct number of cores sharing last level cache

[Borislav Petkov]

On Tue, Jun 06, 2017 at 12:15:30PM +0200, Peter Zijlstra wrote:
> Maybe something like:
> 
> 	for (cache_level = 0; cache_level < 3; cache_level++) {
> 		cpuid_count(0x8000001d, cache_level, &eax, &ebx, &ecx, &edx);
> 
> 		if ((eax & 0x1f) == 0) /* EAX[0:4] gives cache type */

		if (!(eax & 0x1f))

> 			break;
> 
> 		prev_eax = eax;
> 	}
> 
> That way we'll not run off into the woods if CPUID goes funny (never
> trust a BIOS/virt monkey).

Yap, especially if there are CPUID functions with subleafs with holes in
them.

-- 
Regards/Gruss,
    Boris.

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