by Yuan, Perry

[permalink] [raw]

Subject: RE: [PATCH v10 3/8] cpufreq: amd-pstate: Unify computation of {max,min,nominal,lowest_nonlinear}_freq

[AMD Official Use Only - General]

> -----Original Message-----
> From: Huang, Ray <[email protected]>
> Sent: Monday, April 15, 2024 10:55 PM
> To: Yuan, Perry <[email protected]>
> Cc: [email protected]; Limonciello, Mario
> <[email protected]>; [email protected]; Shenoy, Gautham
> Ranjal <[email protected]>; Petkov, Borislav
> <[email protected]>; Deucher, Alexander
> <[email protected]>; Huang, Shimmer
> <[email protected]>; [email protected]; Du, Xiaojian
> <[email protected]>; Meng, Li (Jassmine) <[email protected]>; linux-
> [email protected]; [email protected]
> Subject: Re: [PATCH v10 3/8] cpufreq: amd-pstate: Unify computation of
> {max,min,nominal,lowest_nonlinear}_freq
>
> On Mon, Mar 25, 2024 at 11:03:23AM +0800, Yuan, Perry wrote:
> > Currently the amd_get_{min, max, nominal, lowest_nonlinear}_freq()
> > helpers computes the values of min_freq, max_freq, nominal_freq and
> > lowest_nominal_freq respectively afresh from cppc_get_perf_caps().
> > This is not necessary as there are fields in cpudata to cache these
> > values.
> >
> > To simplify this, add a single helper function named
> > amd_pstate_init_freq() which computes all these frequencies at once,
> > and caches it in cpudata.
> >
> > Use the cached values everywhere else in the code.
> >
> > Reviewed-by: Li Meng <[email protected]>
> > Tested-by: Dhananjay Ugwekar <[email protected]>
> > Co-developed-by: Gautham R. Shenoy <[email protected]>
> > Signed-off-by: Gautham R. Shenoy <[email protected]>
> > Signed-off-by: Perry Yuan <[email protected]>
>
> I am thinking patch 3 and 4 should be squeezed together, because they are all
> refining frequencies in cpudata. But I am fine if you want to continue keep
> them separately.

Yes, we would like to keep changes in two patches, then patches don't need to get review again in v11.
Thanks.

Perry.

>
> > ---
> > drivers/cpufreq/amd-pstate.c | 126
> > ++++++++++++++++-------------------
> > 1 file changed, 59 insertions(+), 67 deletions(-)
> >
> > diff --git a/drivers/cpufreq/amd-pstate.c
> > b/drivers/cpufreq/amd-pstate.c index 2015c9fcc3c9..ba1baa6733e6
> 100644
> > --- a/drivers/cpufreq/amd-pstate.c
> > +++ b/drivers/cpufreq/amd-pstate.c
> > @@ -606,74 +606,22 @@ 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;
> > -
> > - int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
> > - if (ret)
> > - return ret;
> > -
> > - /* Switch to khz */
> > - return cppc_perf.lowest_freq * 1000;
> > + return READ_ONCE(cpudata->min_freq);
> > }
> >
> > static int amd_get_max_freq(struct amd_cpudata *cpudata) {
> > - struct cppc_perf_caps cppc_perf;
> > - u32 max_perf, max_freq, nominal_freq, nominal_perf;
> > - u64 boost_ratio;
> > -
> > - int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
> > - if (ret)
> > - return ret;
> > -
> > - nominal_freq = cppc_perf.nominal_freq;
> > - nominal_perf = READ_ONCE(cpudata->nominal_perf);
> > - max_perf = READ_ONCE(cpudata->highest_perf);
> > -
> > - boost_ratio = div_u64(max_perf << SCHED_CAPACITY_SHIFT,
> > - nominal_perf);
> > -
> > - max_freq = nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT;
> > -
> > - /* Switch to khz */
> > - return max_freq * 1000;
> > + return READ_ONCE(cpudata->max_freq);
> > }
> >
> > static int amd_get_nominal_freq(struct amd_cpudata *cpudata) {
> > - struct cppc_perf_caps cppc_perf;
> > -
> > - int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
> > - if (ret)
> > - return ret;
> > -
> > - /* Switch to khz */
> > - return cppc_perf.nominal_freq * 1000;
> > + return READ_ONCE(cpudata->nominal_freq);
> > }
> >
> > static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)
> > {
> > - struct cppc_perf_caps cppc_perf;
> > - u32 lowest_nonlinear_freq, lowest_nonlinear_perf,
> > - nominal_freq, nominal_perf;
> > - u64 lowest_nonlinear_ratio;
> > -
> > - int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
> > - if (ret)
> > - return ret;
> > -
> > - nominal_freq = cppc_perf.nominal_freq;
> > - nominal_perf = READ_ONCE(cpudata->nominal_perf);
> > -
> > - lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
> > -
> > - lowest_nonlinear_ratio = div_u64(lowest_nonlinear_perf <<
> SCHED_CAPACITY_SHIFT,
> > - nominal_perf);
> > -
> > - lowest_nonlinear_freq = nominal_freq * lowest_nonlinear_ratio >>
> SCHED_CAPACITY_SHIFT;
> > -
> > - /* Switch to khz */
> > - return lowest_nonlinear_freq * 1000;
> > + return READ_ONCE(cpudata->lowest_nonlinear_freq);
> > }
> >
> > static int amd_pstate_set_boost(struct cpufreq_policy *policy, int
> > state) @@ -828,6 +776,53 @@ static void
> amd_pstate_update_limits(unsigned int cpu)
> > mutex_unlock(&amd_pstate_driver_lock);
> > }
> >
> > +/**
> > + * amd_pstate_init_freq: Initialize the max_freq, min_freq,
> > + * nominal_freq and lowest_nonlinear_freq for
> > + * the @cpudata object.
> > + *
> > + * Requires: highest_perf, lowest_perf, nominal_perf and
> > + * lowest_nonlinear_perf members of @cpudata to be
> > + * initialized.
> > + *
> > + * Returns 0 on success, non-zero value on failure.
> > + */
> > +static int amd_pstate_init_freq(struct amd_cpudata *cpudata) {
> > + int ret;
> > + u32 min_freq;
> > + u32 highest_perf, max_freq;
> > + u32 nominal_perf, nominal_freq;
> > + u32 lowest_nonlinear_perf, lowest_nonlinear_freq;
> > + u32 boost_ratio, lowest_nonlinear_ratio;
> > + struct cppc_perf_caps cppc_perf;
> > +
> > +
> > + ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
> > + if (ret)
> > + return ret;
> > +
> > + min_freq = cppc_perf.lowest_freq * 1000;
> > + nominal_freq = cppc_perf.nominal_freq * 1000;
> > + nominal_perf = READ_ONCE(cpudata->nominal_perf);
> > +
> > + highest_perf = READ_ONCE(cpudata->highest_perf);
> > + boost_ratio = div_u64(highest_perf << SCHED_CAPACITY_SHIFT,
> nominal_perf);
> > + max_freq = nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT;
> > +
> > + lowest_nonlinear_perf = READ_ONCE(cpudata-
> >lowest_nonlinear_perf);
> > + lowest_nonlinear_ratio = div_u64(lowest_nonlinear_perf <<
> SCHED_CAPACITY_SHIFT,
> > + nominal_perf);
> > + lowest_nonlinear_freq = nominal_freq * lowest_nonlinear_ratio >>
> > +SCHED_CAPACITY_SHIFT;
> > +
> > + WRITE_ONCE(cpudata->min_freq, min_freq);
> > + WRITE_ONCE(cpudata->lowest_nonlinear_freq,
> lowest_nonlinear_freq);
> > + WRITE_ONCE(cpudata->nominal_freq, nominal_freq);
> > + WRITE_ONCE(cpudata->max_freq, max_freq);
> > +
> > + return 0;
> > +}
> > +
> > static int amd_pstate_cpu_init(struct cpufreq_policy *policy) {
> > int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret;
> @@
> > -855,6 +850,10 @@ static int amd_pstate_cpu_init(struct cpufreq_policy
> *policy)
> > if (ret)
> > goto free_cpudata1;
> >
> > + ret = amd_pstate_init_freq(cpudata);
> > + if (ret)
> > + goto free_cpudata1;
> > +
> > min_freq = amd_get_min_freq(cpudata);
> > max_freq = amd_get_max_freq(cpudata);
> > nominal_freq = amd_get_nominal_freq(cpudata); @@ -896,13
> +895,8 @@
> > static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
> > goto free_cpudata2;
> > }
> >
> > - /* Initial processor data capability frequencies */
> > - cpudata->max_freq = max_freq;
> > - cpudata->min_freq = min_freq;
> > cpudata->max_limit_freq = max_freq;
> > cpudata->min_limit_freq = min_freq;
> > - cpudata->nominal_freq = nominal_freq;
> > - cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
> >
> > policy->driver_data = cpudata;
> >
> > @@ -1317,6 +1311,10 @@ static int amd_pstate_epp_cpu_init(struct
> cpufreq_policy *policy)
> > if (ret)
> > goto free_cpudata1;
> >
> > + ret = amd_pstate_init_freq(cpudata);
> > + if (ret)
> > + goto free_cpudata1;
> > +
> > min_freq = amd_get_min_freq(cpudata);
> > max_freq = amd_get_max_freq(cpudata);
> > nominal_freq = amd_get_nominal_freq(cpudata); @@ -1333,12
> +1331,6 @@
> > static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
> > /* It will be updated by governor */
> > policy->cur = policy->cpuinfo.min_freq;
> >
> > - /* Initial processor data capability frequencies */
> > - cpudata->max_freq = max_freq;
> > - cpudata->min_freq = min_freq;
> > - cpudata->nominal_freq = nominal_freq;
> > - cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
> > -
> > policy->driver_data = cpudata;
> >
> > cpudata->epp_cached = amd_pstate_get_epp(cpudata, 0);
> > --
> > 2.34.1
> >

2024-04-22 09:50:58

by Yuan, Perry

[permalink] [raw]

Subject: RE: [PATCH v10 8/8] cpufreq: amd-pstate: Add quirk for the pstate CPPC capabilities missing

[AMD Official Use Only - General]

Hi Ray,

> -----Original Message-----
> From: Huang, Ray <[email protected]>
> Sent: Monday, April 15, 2024 11:16 PM
> To: Yuan, Perry <[email protected]>
> Cc: [email protected]; Limonciello, Mario
> <[email protected]>; [email protected]; Shenoy, Gautham
> Ranjal <[email protected]>; Petkov, Borislav
> <[email protected]>; Deucher, Alexander
> <[email protected]>; Huang, Shimmer <[email protected]>;
> [email protected]; Du, Xiaojian <[email protected]>; Meng, Li
> (Jassmine) <[email protected]>; [email protected]; linux-
> [email protected]
> Subject: Re: [PATCH v10 8/8] cpufreq: amd-pstate: Add quirk for the pstate CPPC
> capabilities missing
>
> On Mon, Mar 25, 2024 at 11:03:28AM +0800, Yuan, Perry 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
> > 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
> >
> > Reviewed-by: Mario Limonciello <[email protected]>
> > Reviewed-by: Gautham R. Shenoy <[email protected]>
> > Tested-by: Dhananjay Ugwekar <[email protected]>
> > Signed-off-by: Perry Yuan <[email protected]>
> > ---
> > drivers/cpufreq/amd-pstate.c | 53 ++++++++++++++++++++++++++++++++++--
> > include/linux/amd-pstate.h | 6 ++++
> > 2 files changed, 57 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/cpufreq/amd-pstate.c
> > b/drivers/cpufreq/amd-pstate.c index ec049b62b366..59a2db225d98 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;
>
> If we set quirks as global pointer, while the amd-pstate is uninstalling, should we
> free the quirks as well?
>
> Thanks,
> Ray

In general, if the `quirks` variable is dynamically allocated during the driver's execution, it should be freed during the driver's uninstallation to avoid memory leaks. If it is a static or constant variable, it does not need to be explicitly freed.
In this patch, quirks is used to store the pointer to "dmi->driver_data", I will add your ack flag for this patch if you have no concern for this.

+ quirks = dmi->driver_data;

Perry.

>
> >
> > /*
> > * AMD Energy Preference Performance (EPP) @@ -111,6 +112,41 @@
> > 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 processor support CPPC V2
> > + * broken BIOS lack of nominal_freq and lowest_freq capabilities
> > + * definition in ACPI tables
> > + */
> > + if (boot_cpu_has(X86_FEATURE_ZEN2)) {
> > + quirks = dmi->driver_data;
> > + pr_info("Overriding nominal and lowest frequencies for %s\n",
> dmi->ident);
> > + return 1;
> > + }
> > +
> > + 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;
> > @@ -812,8 +848,16 @@ static int amd_pstate_init_freq(struct amd_cpudata
> *cpudata)
> > if (ret)
> > return ret;
> >
> > - min_freq = cppc_perf.lowest_freq * 1000;
> > - nominal_freq = cppc_perf.nominal_freq * 1000;
> > + if (quirks && quirks->lowest_freq)
> > + min_freq = quirks->lowest_freq * 1000;
> > + else
> > + min_freq = cppc_perf.lowest_freq * 1000;
> > +
> > + if (quirks && quirks->nominal_freq)
> > + nominal_freq = quirks->nominal_freq * 1000;
> > + else
> > + nominal_freq = cppc_perf.nominal_freq * 1000;
> > +
> > nominal_perf = READ_ONCE(cpudata->nominal_perf);
> >
> > highest_perf = READ_ONCE(cpudata->highest_perf); @@ -1662,6
> +1706,11
> > @@ 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 ab7e82533718..6b832153a126 100644
> > --- a/include/linux/amd-pstate.h
> > +++ b/include/linux/amd-pstate.h
> > @@ -128,4 +128,10 @@ 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 */
> > --
> > 2.34.1
> >