[AMD Official Use Only - General]
Hi Reinette,
> -----Original Message-----
> From: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Sent: Tuesday, November 22, 2022 6:13 PM
> To: Moger, Babu <Babu.Moger@xxxxxxx>; corbet@xxxxxxx;
> tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; bp@xxxxxxxxx
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> Subject: Re: [PATCH v8 05/13] x86/resctrl: Detect and configure Slow Memory
> Bandwidth Allocation
>
> Hi Babu,
>
> On 11/4/2022 1:00 PM, Babu Moger wrote:
> > The QoS slow memory configuration details are available via
> > CPUID_Fn80000020_EDX_x02. Detect the available details and initialize
> > the rest to defaults.
> >
> > Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> > ---
> > arch/x86/kernel/cpu/resctrl/core.c | 36
> +++++++++++++++++++++++++++--
> > arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 2 +-
> > arch/x86/kernel/cpu/resctrl/internal.h | 1 +
> > arch/x86/kernel/cpu/resctrl/rdtgroup.c | 8 ++++--
> > 4 files changed, 41 insertions(+), 6 deletions(-)
> >
> > diff --git a/arch/x86/kernel/cpu/resctrl/core.c
> > b/arch/x86/kernel/cpu/resctrl/core.c
> > index e31c98e2fafc..6571d08e2b0d 100644
> > --- a/arch/x86/kernel/cpu/resctrl/core.c
> > +++ b/arch/x86/kernel/cpu/resctrl/core.c
> > @@ -162,6 +162,13 @@ bool is_mba_sc(struct rdt_resource *r)
> > if (!r)
> > return
> rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl.membw.mba_sc;
> >
> > + /*
> > + * The software controller support is only applicable to MBA resource.
> > + * Make sure to check for resource type again.
> > + */
>
> /again/d
Sure.
>
> Not all callers of is_mba_sc() check if it is called for an MBA resource.
>
> > + if (r->rid != RDT_RESOURCE_MBA)
> > + return false;
> > +
> > return r->membw.mba_sc;
> > }
> >
> > @@ -225,9 +232,15 @@ static bool __rdt_get_mem_config_amd(struct
> rdt_resource *r)
> > struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
> > union cpuid_0x10_3_eax eax;
> > union cpuid_0x10_x_edx edx;
> > - u32 ebx, ecx;
> > + u32 ebx, ecx, subleaf;
> >
> > - cpuid_count(0x80000020, 1, &eax.full, &ebx, &ecx, &edx.full);
> > + /*
> > + * Query CPUID_Fn80000020_EDX_x01 for MBA and
> > + * CPUID_Fn80000020_EDX_x02 for SMBA
> > + */
> > + subleaf = (r->rid == RDT_RESOURCE_SMBA) ? 2 : 1;
> > +
> > + cpuid_count(0x80000020, subleaf, &eax.full, &ebx, &ecx, &edx.full);
> > hw_res->num_closid = edx.split.cos_max + 1;
> > r->default_ctrl = MAX_MBA_BW_AMD;
> >
> > @@ -750,6 +763,19 @@ static __init bool get_mem_config(void)
> > return false;
> > }
> >
> > +static __init bool get_slow_mem_config(void) {
> > + struct rdt_hw_resource *hw_res =
> > +&rdt_resources_all[RDT_RESOURCE_SMBA];
> > +
> > + if (!rdt_cpu_has(X86_FEATURE_SMBA))
> > + return false;
> > +
> > + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
> > + return __rdt_get_mem_config_amd(&hw_res->r_resctrl);
> > +
> > + return false;
> > +}
> > +
> > static __init bool get_rdt_alloc_resources(void) {
> > struct rdt_resource *r;
> > @@ -780,6 +806,9 @@ static __init bool get_rdt_alloc_resources(void)
> > if (get_mem_config())
> > ret = true;
> >
> > + if (get_slow_mem_config())
> > + ret = true;
> > +
> > return ret;
> > }
> >
> > @@ -869,6 +898,9 @@ static __init void rdt_init_res_defs_amd(void)
> > } else if (r->rid == RDT_RESOURCE_MBA) {
> > hw_res->msr_base = MSR_IA32_MBA_BW_BASE;
> > hw_res->msr_update = mba_wrmsr_amd;
> > + } else if (r->rid == RDT_RESOURCE_SMBA) {
> > + hw_res->msr_base = MSR_IA32_SMBA_BW_BASE;
> > + hw_res->msr_update = mba_wrmsr_amd;
> > }
> > }
> > }
>
> I mentioned earlier that this can be moved to init of rdt_resources_all[]. No
> strong preference, leaving here works also.
Sure. Will do.
Thanks
Babu
>
> Reinette
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