Messages in this thread | | | From | "Yuan, Perry" <> | Subject | RE: [PATCH v4 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing | Date | Wed, 7 Feb 2024 07:13:50 +0000 |
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[AMD Official Use Only - General]
Hi Mario,
> -----Original Message----- > From: Limonciello, Mario <Mario.Limonciello@amd.com> > Sent: Tuesday, February 6, 2024 11:46 PM > To: Yuan, Perry <Perry.Yuan@amd.com>; rafael.j.wysocki@intel.com; > viresh.kumar@linaro.org; Huang, Ray <Ray.Huang@amd.com>; Shenoy, > Gautham Ranjal <gautham.shenoy@amd.com>; Petkov, Borislav > <Borislav.Petkov@amd.com> > Cc: Deucher, Alexander <Alexander.Deucher@amd.com>; Huang, Shimmer > <Shimmer.Huang@amd.com>; Du, Xiaojian <Xiaojian.Du@amd.com>; Meng, > Li (Jassmine) <Li.Meng@amd.com>; linux-pm@vger.kernel.org; linux- > kernel@vger.kernel.org > Subject: Re: [PATCH v4 6/6] cpufreq:amd-pstate: add quirk for the pstate > CPPC capabilities missing > > On 2/5/2024 22:33, Perry Yuan wrote: > > Add quirks table to get CPPC capabilities issue fixed by providing > > correct perf or frequency values while driver loading. > > > > If CPPC capabilities are not defined in the ACPI tables or wrongly > > defined by platform firmware, it needs to use quick to get those > s,quick,a quirk, > > issues fixed with correct workaround values to make pstate driver can > > be loaded even though there are CPPC capabilities errors. > > > > The workaround will match the broken BIOS which lack of CPPC > > capabilities nominal_freq and lowest_freq definition in the ACPI table. > > > > $ cat /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_freq > > 0 > > $ cat /sys/devices/system/cpu/cpu0/acpi_cppc/nominal_freq > > 0 > > > > Signed-off-by: Perry Yuan <perry.yuan@amd.com> > > --- > > drivers/cpufreq/amd-pstate.c | 59 > ++++++++++++++++++++++++++++++++++-- > > include/linux/amd-pstate.h | 6 ++++ > > 2 files changed, 63 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/cpufreq/amd-pstate.c > > b/drivers/cpufreq/amd-pstate.c index 77effc3caf6c..874d8b663790 100644 > > --- a/drivers/cpufreq/amd-pstate.c > > +++ b/drivers/cpufreq/amd-pstate.c > > @@ -67,6 +67,7 @@ static struct cpufreq_driver amd_pstate_epp_driver; > > static int cppc_state = AMD_PSTATE_UNDEFINED; > > static bool cppc_enabled; > > static bool amd_pstate_prefcore = true; > > +static struct quirk_entry *quirks; > > > > /* > > * AMD Energy Preference Performance (EPP) @@ -111,6 +112,43 @@ > > static unsigned int epp_values[] = { > > > > typedef int (*cppc_mode_transition_fn)(int); > > > > +static struct quirk_entry quirk_amd_7k62 = { > > + .nominal_freq = 2600, > > + .lowest_freq = 550, > > +}; > > + > > +static int __init dmi_matched_7k62_bios_bug(const struct > > +dmi_system_id *dmi) { > > + /** > > + * match the broken bios for family 17h, model 31h processor > > + * broken BIOS lack of nominal_freq and lowest_freq capabilities > > + * definition in ACPI tables > > + */ > > + if (boot_cpu_data.x86 == 0x17 && boot_cpu_data.x86_model == > 0x31 && > > + boot_cpu_has(X86_FEATURE_ZEN2)) { > > I think you should use one or the other (17/31) or (X86_FEATURE_ZEN2).
Looks like it makes sense to match ZEN2 flag and specific BIOS version. That will cover the broken BIOS and CPU.
> > > + quirks = dmi->driver_data; > > + pr_info("hardware type %s found\n", dmi->ident); > > I think a better message explains what is happening. For example: > "Overriding nominal and lowest frequencies for %s\n"
Made suggestions to v5.
> > > + return 1; > > + } > > + > > + > > Only need one newline needed here.
Fixed in V5.
Thanks for the review comments!
Perry.
> > > + return 0; > > +} > > + > > +static const struct dmi_system_id amd_pstate_quirks_table[] __initconst > = { > > + { > > + .callback = dmi_matched_7k62_bios_bug, > > + .ident = "AMD EPYC 7K62", > > + .matches = { > > + DMI_MATCH(DMI_BIOS_VERSION, "5.14"), > > + DMI_MATCH(DMI_BIOS_RELEASE, "12/12/2019"), > > + }, > > + .driver_data = &quirk_amd_7k62, > > + }, > > + {} > > +}; > > +MODULE_DEVICE_TABLE(dmi, amd_pstate_quirks_table); > > + > > static inline int get_mode_idx_from_str(const char *str, size_t size) > > { > > int i; > > @@ -600,13 +638,19 @@ static void amd_pstate_adjust_perf(unsigned int > cpu, > > static int amd_get_min_freq(struct amd_cpudata *cpudata) > > { > > struct cppc_perf_caps cppc_perf; > > + u32 lowest_freq; > > > > int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); > > if (ret) > > return ret; > > > > + if (quirks && quirks->lowest_freq) > > + lowest_freq = quirks->lowest_freq; > > + else > > + lowest_freq = cppc_perf.lowest_freq; > > + > > /* Switch to khz */ > > - return cppc_perf.lowest_freq * 1000; > > + return lowest_freq * 1000; > > } > > > > static int amd_get_max_freq(struct amd_cpudata *cpudata) @@ -635,12 > > +679,18 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata) > > static int amd_get_nominal_freq(struct amd_cpudata *cpudata) > > { > > struct cppc_perf_caps cppc_perf; > > + u32 nominal_freq; > > > > int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); > > if (ret) > > return ret; > > > > - return cppc_perf.nominal_freq; > > + if (quirks && quirks->nominal_freq) > > + nominal_freq = quirks->nominal_freq; > > + else > > + nominal_freq = cppc_perf.nominal_freq; > > + > > + return nominal_freq; > > } > > > > static int amd_get_lowest_nonlinear_freq(struct amd_cpudata > > *cpudata) @@ -1672,6 +1722,11 @@ static int __init amd_pstate_init(void) > > if (cpufreq_get_current_driver()) > > return -EEXIST; > > > > + quirks = NULL; > > + > > + /* check if this machine need CPPC quirks */ > > + dmi_check_system(amd_pstate_quirks_table); > > + > > switch (cppc_state) { > > case AMD_PSTATE_UNDEFINED: > > /* Disable on the following configs by default: > > diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h > > index d21838835abd..7b2cbb892fd9 100644 > > --- a/include/linux/amd-pstate.h > > +++ b/include/linux/amd-pstate.h > > @@ -124,4 +124,10 @@ static const char * const > amd_pstate_mode_string[] = { > > [AMD_PSTATE_GUIDED] = "guided", > > NULL, > > }; > > + > > +struct quirk_entry { > > + u32 nominal_freq; > > + u32 lowest_freq; > > +}; > > + > > #endif /* _LINUX_AMD_PSTATE_H */
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