Messages in this thread | | | Date | Tue, 6 Feb 2024 09:45:47 -0600 | Subject | Re: [PATCH v4 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing | From | Mario Limonciello <> |
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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).
> + 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"
> + return 1; > + } > + > +
Only need one newline needed here.
> + 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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