From ACPI spec below 3 modes for CPPC can be defined:
1. Non autonomous: OS scaling governor specifies operating frequency/
performance level through `Desired Performance` register and platform
follows that.
2. Guided autonomous: OS scaling governor specifies min and max
frequencies/ performance levels through `Minimum Performance` and
`Maximum Performance` register, and platform can autonomously select an
operating frequency in this range.
3. Fully autonomous: OS only hints (via EPP) to platform for the required
energy performance preference for the workload and platform autonomously
scales the frequency.
Currently (1) is supported by amd_pstate as passive mode, and (3) is
implemented by EPP support. This change is to support (2).
In guided autonomous mode the min_perf is based on the input from the
scaling governor. For example, in case of schedutil this value depends
on the current utilization. And max_perf is set to max capacity.
To activate guided auto mode ``amd_pstate=guided`` command line
parameter has to be passed in the kernel.
Signed-off-by: Wyes Karny <wyes.karny@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
---
.../admin-guide/kernel-parameters.txt | 15 +++++---
drivers/cpufreq/amd-pstate.c | 34 +++++++++++++++----
include/linux/amd-pstate.h | 2 ++
3 files changed, 40 insertions(+), 11 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index e3618dfdb36a..56d5c189e458 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -7015,11 +7015,11 @@
Do not enable amd_pstate as the default
scaling driver for the supported processors
passive
- Use amd_pstate as a scaling driver, driver requests a
- desired performance on this abstract scale and the power
- management firmware translates the requests into actual
- hardware states (core frequency, data fabric and memory
- clocks etc.)
+ Use amd_pstate with passive mode as a scaling driver.
+ In this mode autonomous selection is disabled.
+ Driver requests a desired performance level and platform
+ tries to match the same performance level if it is
+ satisfied by guaranteed performance level.
active
Use amd_pstate_epp driver instance as the scaling driver,
driver provides a hint to the hardware if software wants
@@ -7027,3 +7027,8 @@
to the CPPC firmware. then CPPC power algorithm will
calculate the runtime workload and adjust the realtime cores
frequency.
+ guided
+ Activate guided autonomous mode. Driver requests minimum and
+ maximum performance level and the platform autonomously
+ selects a performance level in this range and appropriate
+ to the current workload.
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 168a28bed6ee..6582c922ad3a 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -308,7 +308,22 @@ static int cppc_init_perf(struct amd_cpudata *cpudata)
cppc_perf.lowest_nonlinear_perf);
WRITE_ONCE(cpudata->lowest_perf, cppc_perf.lowest_perf);
- return 0;
+ if (cppc_state == AMD_PSTATE_ACTIVE)
+ return 0;
+
+ ret = cppc_get_auto_sel_caps(cpudata->cpu, &cppc_perf);
+ if (ret) {
+ pr_warn("failed to get auto_sel, ret: %d\n", ret);
+ return 0;
+ }
+
+ ret = cppc_set_auto_sel(cpudata->cpu,
+ (cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1);
+
+ if (ret)
+ pr_warn("failed to set auto_sel, ret: %d\n", ret);
+
+ return ret;
}
DEFINE_STATIC_CALL(amd_pstate_init_perf, pstate_init_perf);
@@ -385,12 +400,18 @@ static inline bool amd_pstate_sample(struct amd_cpudata *cpudata)
}
static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
- u32 des_perf, u32 max_perf, bool fast_switch)
+ u32 des_perf, u32 max_perf, bool fast_switch, int gov_flags)
{
u64 prev = READ_ONCE(cpudata->cppc_req_cached);
u64 value = prev;
des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
+
+ if ((cppc_state == AMD_PSTATE_GUIDED) && (gov_flags & CPUFREQ_GOV_DYNAMIC_SWITCHING)) {
+ min_perf = des_perf;
+ des_perf = 0;
+ }
+
value &= ~AMD_CPPC_MIN_PERF(~0L);
value |= AMD_CPPC_MIN_PERF(min_perf);
@@ -445,7 +466,7 @@ static int amd_pstate_target(struct cpufreq_policy *policy,
cpufreq_freq_transition_begin(policy, &freqs);
amd_pstate_update(cpudata, min_perf, des_perf,
- max_perf, false);
+ max_perf, false, policy->governor->flags);
cpufreq_freq_transition_end(policy, &freqs, false);
return 0;
@@ -479,7 +500,8 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
if (max_perf < min_perf)
max_perf = min_perf;
- amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true);
+ amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true,
+ policy->governor->flags);
cpufreq_cpu_put(policy);
}
@@ -1279,7 +1301,7 @@ static int __init amd_pstate_init(void)
/* capability check */
if (boot_cpu_has(X86_FEATURE_CPPC)) {
pr_debug("AMD CPPC MSR based functionality is supported\n");
- if (cppc_state == AMD_PSTATE_PASSIVE)
+ if (cppc_state != AMD_PSTATE_ACTIVE)
current_pstate_driver->adjust_perf = amd_pstate_adjust_perf;
} else {
pr_debug("AMD CPPC shared memory based functionality is supported\n");
@@ -1341,7 +1363,7 @@ static int __init amd_pstate_param(char *str)
if (cppc_state == AMD_PSTATE_ACTIVE)
current_pstate_driver = &amd_pstate_epp_driver;
- if (cppc_state == AMD_PSTATE_PASSIVE)
+ if (cppc_state == AMD_PSTATE_PASSIVE || cppc_state == AMD_PSTATE_GUIDED)
current_pstate_driver = &amd_pstate_driver;
return 0;
diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h
index f5f22418e64b..c10ebf8c42e6 100644
--- a/include/linux/amd-pstate.h
+++ b/include/linux/amd-pstate.h
@@ -97,6 +97,7 @@ enum amd_pstate_mode {
AMD_PSTATE_DISABLE = 0,
AMD_PSTATE_PASSIVE,
AMD_PSTATE_ACTIVE,
+ AMD_PSTATE_GUIDED,
AMD_PSTATE_MAX,
};
@@ -104,6 +105,7 @@ static const char * const amd_pstate_mode_string[] = {
[AMD_PSTATE_DISABLE] = "disable",
[AMD_PSTATE_PASSIVE] = "passive",
[AMD_PSTATE_ACTIVE] = "active",
+ [AMD_PSTATE_GUIDED] = "guided",
NULL,
};
#endif /* _LINUX_AMD_PSTATE_H */
--
2.34.1
On Tue, Feb 07, 2023 at 01:21:54AM +0800, Karny, Wyes wrote: > From ACPI spec below 3 modes for CPPC can be defined: > 1. Non autonomous: OS scaling governor specifies operating frequency/ > performance level through `Desired Performance` register and platform > follows that. > 2. Guided autonomous: OS scaling governor specifies min and max > frequencies/ performance levels through `Minimum Performance` and > `Maximum Performance` register, and platform can autonomously select an > operating frequency in this range. I believe the processors which are not sensitive to power consumption can use this mode. Because this way can have better performance than "non autonomous" mode. :-) > 3. Fully autonomous: OS only hints (via EPP) to platform for the required > energy performance preference for the workload and platform autonomously > scales the frequency. > > Currently (1) is supported by amd_pstate as passive mode, and (3) is > implemented by EPP support. This change is to support (2). > > In guided autonomous mode the min_perf is based on the input from the > scaling governor. For example, in case of schedutil this value depends > on the current utilization. And max_perf is set to max capacity. > > To activate guided auto mode ``amd_pstate=guided`` command line > parameter has to be passed in the kernel. > > Signed-off-by: Wyes Karny <wyes.karny@amd.com> > Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> Wyes, could you still use prefix "cpufreq: amd-pstate:" as the subject to align the previous patches? Because it's easy to sort out all amd-pstate patches for us. Acked-by: Huang Rui <ray.huang@amd.com> > --- > .../admin-guide/kernel-parameters.txt | 15 +++++--- > drivers/cpufreq/amd-pstate.c | 34 +++++++++++++++---- > include/linux/amd-pstate.h | 2 ++ > 3 files changed, 40 insertions(+), 11 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index e3618dfdb36a..56d5c189e458 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -7015,11 +7015,11 @@ > Do not enable amd_pstate as the default > scaling driver for the supported processors > passive > - Use amd_pstate as a scaling driver, driver requests a > - desired performance on this abstract scale and the power > - management firmware translates the requests into actual > - hardware states (core frequency, data fabric and memory > - clocks etc.) > + Use amd_pstate with passive mode as a scaling driver. > + In this mode autonomous selection is disabled. > + Driver requests a desired performance level and platform > + tries to match the same performance level if it is > + satisfied by guaranteed performance level. > active > Use amd_pstate_epp driver instance as the scaling driver, > driver provides a hint to the hardware if software wants > @@ -7027,3 +7027,8 @@ > to the CPPC firmware. then CPPC power algorithm will > calculate the runtime workload and adjust the realtime cores > frequency. > + guided > + Activate guided autonomous mode. Driver requests minimum and > + maximum performance level and the platform autonomously > + selects a performance level in this range and appropriate > + to the current workload. > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > index 168a28bed6ee..6582c922ad3a 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -308,7 +308,22 @@ static int cppc_init_perf(struct amd_cpudata *cpudata) > cppc_perf.lowest_nonlinear_perf); > WRITE_ONCE(cpudata->lowest_perf, cppc_perf.lowest_perf); > > - return 0; > + if (cppc_state == AMD_PSTATE_ACTIVE) > + return 0; > + > + ret = cppc_get_auto_sel_caps(cpudata->cpu, &cppc_perf); > + if (ret) { > + pr_warn("failed to get auto_sel, ret: %d\n", ret); > + return 0; > + } > + > + ret = cppc_set_auto_sel(cpudata->cpu, > + (cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1); > + > + if (ret) > + pr_warn("failed to set auto_sel, ret: %d\n", ret); > + > + return ret; > } > > DEFINE_STATIC_CALL(amd_pstate_init_perf, pstate_init_perf); > @@ -385,12 +400,18 @@ static inline bool amd_pstate_sample(struct amd_cpudata *cpudata) > } > > static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf, > - u32 des_perf, u32 max_perf, bool fast_switch) > + u32 des_perf, u32 max_perf, bool fast_switch, int gov_flags) > { > u64 prev = READ_ONCE(cpudata->cppc_req_cached); > u64 value = prev; > > des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf); > + > + if ((cppc_state == AMD_PSTATE_GUIDED) && (gov_flags & CPUFREQ_GOV_DYNAMIC_SWITCHING)) { > + min_perf = des_perf; > + des_perf = 0; > + } > + > value &= ~AMD_CPPC_MIN_PERF(~0L); > value |= AMD_CPPC_MIN_PERF(min_perf); > > @@ -445,7 +466,7 @@ static int amd_pstate_target(struct cpufreq_policy *policy, > > cpufreq_freq_transition_begin(policy, &freqs); > amd_pstate_update(cpudata, min_perf, des_perf, > - max_perf, false); > + max_perf, false, policy->governor->flags); > cpufreq_freq_transition_end(policy, &freqs, false); > > return 0; > @@ -479,7 +500,8 @@ static void amd_pstate_adjust_perf(unsigned int cpu, > if (max_perf < min_perf) > max_perf = min_perf; > > - amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true); > + amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true, > + policy->governor->flags); > cpufreq_cpu_put(policy); > } > > @@ -1279,7 +1301,7 @@ static int __init amd_pstate_init(void) > /* capability check */ > if (boot_cpu_has(X86_FEATURE_CPPC)) { > pr_debug("AMD CPPC MSR based functionality is supported\n"); > - if (cppc_state == AMD_PSTATE_PASSIVE) > + if (cppc_state != AMD_PSTATE_ACTIVE) > current_pstate_driver->adjust_perf = amd_pstate_adjust_perf; > } else { > pr_debug("AMD CPPC shared memory based functionality is supported\n"); > @@ -1341,7 +1363,7 @@ static int __init amd_pstate_param(char *str) > if (cppc_state == AMD_PSTATE_ACTIVE) > current_pstate_driver = &amd_pstate_epp_driver; > > - if (cppc_state == AMD_PSTATE_PASSIVE) > + if (cppc_state == AMD_PSTATE_PASSIVE || cppc_state == AMD_PSTATE_GUIDED) > current_pstate_driver = &amd_pstate_driver; > > return 0; > diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h > index f5f22418e64b..c10ebf8c42e6 100644 > --- a/include/linux/amd-pstate.h > +++ b/include/linux/amd-pstate.h > @@ -97,6 +97,7 @@ enum amd_pstate_mode { > AMD_PSTATE_DISABLE = 0, > AMD_PSTATE_PASSIVE, > AMD_PSTATE_ACTIVE, > + AMD_PSTATE_GUIDED, > AMD_PSTATE_MAX, > }; > > @@ -104,6 +105,7 @@ static const char * const amd_pstate_mode_string[] = { > [AMD_PSTATE_DISABLE] = "disable", > [AMD_PSTATE_PASSIVE] = "passive", > [AMD_PSTATE_ACTIVE] = "active", > + [AMD_PSTATE_GUIDED] = "guided", > NULL, > }; > #endif /* _LINUX_AMD_PSTATE_H */ > -- > 2.34.1 >
On 16 Feb 14:08, Huang Rui wrote: > On Tue, Feb 07, 2023 at 01:21:54AM +0800, Karny, Wyes wrote: > > From ACPI spec below 3 modes for CPPC can be defined: > > 1. Non autonomous: OS scaling governor specifies operating frequency/ > > performance level through `Desired Performance` register and platform > > follows that. > > 2. Guided autonomous: OS scaling governor specifies min and max > > frequencies/ performance levels through `Minimum Performance` and > > `Maximum Performance` register, and platform can autonomously select an > > operating frequency in this range. > > I believe the processors which are not sensitive to power consumption can > use this mode. Because this way can have better performance than "non > autonomous" mode. :-) > > > 3. Fully autonomous: OS only hints (via EPP) to platform for the required > > energy performance preference for the workload and platform autonomously > > scales the frequency. > > > > Currently (1) is supported by amd_pstate as passive mode, and (3) is > > implemented by EPP support. This change is to support (2). > > > > In guided autonomous mode the min_perf is based on the input from the > > scaling governor. For example, in case of schedutil this value depends > > on the current utilization. And max_perf is set to max capacity. > > > > To activate guided auto mode ``amd_pstate=guided`` command line > > parameter has to be passed in the kernel. > > > > Signed-off-by: Wyes Karny <wyes.karny@amd.com> > > Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> > > Wyes, could you still use prefix "cpufreq: amd-pstate:" as the subject to > align the previous patches? Because it's easy to sort out all amd-pstate > patches for us. Sure, will do. Thanks, Wyes > > Acked-by: Huang Rui <ray.huang@amd.com> > > > --- > > .../admin-guide/kernel-parameters.txt | 15 +++++--- > > drivers/cpufreq/amd-pstate.c | 34 +++++++++++++++---- > > include/linux/amd-pstate.h | 2 ++ > > 3 files changed, 40 insertions(+), 11 deletions(-) > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > > index e3618dfdb36a..56d5c189e458 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -7015,11 +7015,11 @@ > > Do not enable amd_pstate as the default > > scaling driver for the supported processors > > passive > > - Use amd_pstate as a scaling driver, driver requests a > > - desired performance on this abstract scale and the power > > - management firmware translates the requests into actual > > - hardware states (core frequency, data fabric and memory > > - clocks etc.) > > + Use amd_pstate with passive mode as a scaling driver. > > + In this mode autonomous selection is disabled. > > + Driver requests a desired performance level and platform > > + tries to match the same performance level if it is > > + satisfied by guaranteed performance level. > > active > > Use amd_pstate_epp driver instance as the scaling driver, > > driver provides a hint to the hardware if software wants > > @@ -7027,3 +7027,8 @@ > > to the CPPC firmware. then CPPC power algorithm will > > calculate the runtime workload and adjust the realtime cores > > frequency. > > + guided > > + Activate guided autonomous mode. Driver requests minimum and > > + maximum performance level and the platform autonomously > > + selects a performance level in this range and appropriate > > + to the current workload. > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > > index 168a28bed6ee..6582c922ad3a 100644 > > --- a/drivers/cpufreq/amd-pstate.c > > +++ b/drivers/cpufreq/amd-pstate.c > > @@ -308,7 +308,22 @@ static int cppc_init_perf(struct amd_cpudata *cpudata) > > cppc_perf.lowest_nonlinear_perf); > > WRITE_ONCE(cpudata->lowest_perf, cppc_perf.lowest_perf); > > > > - return 0; > > + if (cppc_state == AMD_PSTATE_ACTIVE) > > + return 0; > > + > > + ret = cppc_get_auto_sel_caps(cpudata->cpu, &cppc_perf); > > + if (ret) { > > + pr_warn("failed to get auto_sel, ret: %d\n", ret); > > + return 0; > > + } > > + > > + ret = cppc_set_auto_sel(cpudata->cpu, > > + (cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1); > > + > > + if (ret) > > + pr_warn("failed to set auto_sel, ret: %d\n", ret); > > + > > + return ret; > > } > > > > DEFINE_STATIC_CALL(amd_pstate_init_perf, pstate_init_perf); > > @@ -385,12 +400,18 @@ static inline bool amd_pstate_sample(struct amd_cpudata *cpudata) > > } > > > > static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf, > > - u32 des_perf, u32 max_perf, bool fast_switch) > > + u32 des_perf, u32 max_perf, bool fast_switch, int gov_flags) > > { > > u64 prev = READ_ONCE(cpudata->cppc_req_cached); > > u64 value = prev; > > > > des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf); > > + > > + if ((cppc_state == AMD_PSTATE_GUIDED) && (gov_flags & CPUFREQ_GOV_DYNAMIC_SWITCHING)) { > > + min_perf = des_perf; > > + des_perf = 0; > > + } > > + > > value &= ~AMD_CPPC_MIN_PERF(~0L); > > value |= AMD_CPPC_MIN_PERF(min_perf); > > > > @@ -445,7 +466,7 @@ static int amd_pstate_target(struct cpufreq_policy *policy, > > > > cpufreq_freq_transition_begin(policy, &freqs); > > amd_pstate_update(cpudata, min_perf, des_perf, > > - max_perf, false); > > + max_perf, false, policy->governor->flags); > > cpufreq_freq_transition_end(policy, &freqs, false); > > > > return 0; > > @@ -479,7 +500,8 @@ static void amd_pstate_adjust_perf(unsigned int cpu, > > if (max_perf < min_perf) > > max_perf = min_perf; > > > > - amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true); > > + amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true, > > + policy->governor->flags); > > cpufreq_cpu_put(policy); > > } > > > > @@ -1279,7 +1301,7 @@ static int __init amd_pstate_init(void) > > /* capability check */ > > if (boot_cpu_has(X86_FEATURE_CPPC)) { > > pr_debug("AMD CPPC MSR based functionality is supported\n"); > > - if (cppc_state == AMD_PSTATE_PASSIVE) > > + if (cppc_state != AMD_PSTATE_ACTIVE) > > current_pstate_driver->adjust_perf = amd_pstate_adjust_perf; > > } else { > > pr_debug("AMD CPPC shared memory based functionality is supported\n"); > > @@ -1341,7 +1363,7 @@ static int __init amd_pstate_param(char *str) > > if (cppc_state == AMD_PSTATE_ACTIVE) > > current_pstate_driver = &amd_pstate_epp_driver; > > > > - if (cppc_state == AMD_PSTATE_PASSIVE) > > + if (cppc_state == AMD_PSTATE_PASSIVE || cppc_state == AMD_PSTATE_GUIDED) > > current_pstate_driver = &amd_pstate_driver; > > > > return 0; > > diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h > > index f5f22418e64b..c10ebf8c42e6 100644 > > --- a/include/linux/amd-pstate.h > > +++ b/include/linux/amd-pstate.h > > @@ -97,6 +97,7 @@ enum amd_pstate_mode { > > AMD_PSTATE_DISABLE = 0, > > AMD_PSTATE_PASSIVE, > > AMD_PSTATE_ACTIVE, > > + AMD_PSTATE_GUIDED, > > AMD_PSTATE_MAX, > > }; > > > > @@ -104,6 +105,7 @@ static const char * const amd_pstate_mode_string[] = { > > [AMD_PSTATE_DISABLE] = "disable", > > [AMD_PSTATE_PASSIVE] = "passive", > > [AMD_PSTATE_ACTIVE] = "active", > > + [AMD_PSTATE_GUIDED] = "guided", > > NULL, > > }; > > #endif /* _LINUX_AMD_PSTATE_H */ > > -- > > 2.34.1 > >
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