[PATCH 09/13] KVM: PPC: Book3S HV: Adapt TLB invalidations to work on POWER9

Benjamin Herrenschmidt benh at au1.ibm.com
Sat Nov 19 08:57:28 AEDT 2016


On Fri, 2016-11-18 at 20:11 +0530, Aneesh Kumar K.V wrote:
> > +      * Work out how many sets the TLB has, for the use of
> > +      * the TLB invalidation loop in book3s_hv_rmhandlers.S.
> > +      */
> > +     if (cpu_has_feature(CPU_FTR_ARCH_300))
> > +             kvm->arch.tlb_sets = 256;       /* POWER9 */
> > +     else if (cpu_has_feature(CPU_FTR_ARCH_207S))
> > +             kvm->arch.tlb_sets = 512;       /* POWER8 */
> > +     else
> > +             kvm->arch.tlb_sets = 128;       /* POWER7 */
> > +
> 
> We have 
> 
> #define POWER7_TLB_SETS         128     /* # sets in POWER7 TLB */
> #define POWER8_TLB_SETS         512     /* # sets in POWER8 TLB */
> #define POWER9_TLB_SETS_HASH    256     /* # sets in POWER9 TLB Hash mode */
> #define POWER9_TLB_SETS_RADIX   128     /* # sets in POWER9 TLB Radix mode */
> 
> May be use that instead of opencoding ?

Both are bad and are going to kill us for future backward
compatibility.

These should be a device-tree property. We can fallback to hard wired
values if it doesn't exist but we should at least look for one.

Note: P8 firmwares all have a bug creating a bogus "tlb-sets" property
in the CPU node, so let's create a new one instead, with 2 entries
(hash vs. radix) or 2 new ones, one for hash and one for radix (when
available).

Cheers,
Ben.



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