On Fri, Jun 14, 2019 at 07:47:01PM +0200, Borislav Petkov wrote:
> On Fri, Jun 14, 2019 at 09:55:28AM -0700, Fenghua Yu wrote:
> > When this function is called, X86_FEATURE_CQM_LLC must be supported and
> > one of X86_FEATURE_CQM_OCCUP_LLC, X86_FEATURE_CQM_MBM_LOCAL, and
> > X86_FEATURE_CQM_MBM_TOTAL must be supported. Otherwise,
> > get_rdt_mon_resource() is returned before calling rdt_get_mon_l3_config().
> >
> > So CPUID.f.0 and CPUID.f.1 must be readable and return meaningful
> > data without testing the features.
>
> How's that?
>
> static void __init get_cqm_info(struct rdt_resource *r)
> {
> u32 eax, ebx, ecx, edx;
>
> /*
> * At this point, CQM LLC and one of occupancy, MBM total, and
> * MBM local monitoring features must be supported.
> */
> cpuid_count(0xf, 1, &eax, &ebx, &ecx, &edx);
>
> if (rdt_mon_features & QOS_L3_OCCUP_EVENT_ID)
> r->num_rmid = ecx + 1;
> else
> /*
> * Fallback maximum range (zero-based) of RMID within
> * this physical processor of all types, in subleaf 0,
> * EBX.
> */
> r->num_rmid = cpuid_ebx(0xf) + 1;
>
> if (rdt_mon_features & (QOS_L3_MBM_TOTAL_EVENT_ID |
> QOS_L3_MBM_LOCAL_EVENT_ID))
> r->mon_scale = ebx;
> else
> r->mon_scale = -1;
> }
This is much better and cleaner! I will copy your code to patch 0001
in the next version.
Thanks.
-Fenghua
