Messages in this thread | | | Subject | Re: [PATCH 2/2] cpufreq: intel_pstate: Process HWP Guaranteed change notification | From | Daniel Lezcano <> | Date | Fri, 20 Aug 2021 15:10:25 +0200 |
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On 20/08/2021 04:40, Srinivas Pandruvada wrote: > It is possible that HWP guaranteed ratio is changed in response to > change in power and thermal limits. For example when Intel Speed Select > performance profile is changed or there is change in TDP, hardware can > send notifications. It is possible that the guaranteed ratio is > increased. This creates an issue when turbo is disabled, as the old > limits set in MSR_HWP_REQUEST are still lower and hardware will clip > to older limits. > > This change enables HWP interrupt and process HWP interrupts. When > guaranteed is changed, calls cpufreq_update_policy() so that driver > callbacks are called to update to new HWP limits. This callback > is called from a delayed workqueue of 10ms to avoid frequent updates. > > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Does this patch depend on 1/2 ?
> --- > drivers/cpufreq/intel_pstate.c | 39 ++++++++++++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > index bb4549959b11..0fd2375c1f1e 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -32,6 +32,7 @@ > #include <asm/cpu_device_id.h> > #include <asm/cpufeature.h> > #include <asm/intel-family.h> > +#include "../drivers/thermal/intel/thermal_interrupt.h" > > #define INTEL_PSTATE_SAMPLING_INTERVAL (10 * NSEC_PER_MSEC) > > @@ -219,6 +220,7 @@ struct global_params { > * @sched_flags: Store scheduler flags for possible cross CPU update > * @hwp_boost_min: Last HWP boosted min performance > * @suspended: Whether or not the driver has been suspended. > + * @hwp_notify_work: workqueue for HWP notifications. > * > * This structure stores per CPU instance data for all CPUs. > */ > @@ -257,6 +259,7 @@ struct cpudata { > unsigned int sched_flags; > u32 hwp_boost_min; > bool suspended; > + struct delayed_work hwp_notify_work; > }; > > static struct cpudata **all_cpu_data; > @@ -1625,6 +1628,40 @@ static void intel_pstate_sysfs_hide_hwp_dynamic_boost(void) > > /************************** sysfs end ************************/ > > +static void intel_pstate_notify_work(struct work_struct *work) > +{ > + mutex_lock(&intel_pstate_driver_lock); > + cpufreq_update_policy(smp_processor_id()); > + wrmsrl(MSR_HWP_STATUS, 0); > + mutex_unlock(&intel_pstate_driver_lock); > +} > + > +void notify_hwp_interrupt(void) > +{ > + unsigned int this_cpu = smp_processor_id(); > + struct cpudata *cpudata; > + u64 value; > + > + if (!hwp_active || !boot_cpu_has(X86_FEATURE_HWP_NOTIFY)) > + return; > + > + rdmsrl(MSR_HWP_STATUS, value); > + if (!(value & 0x01)) > + return; > + > + cpudata = all_cpu_data[this_cpu]; > + schedule_delayed_work_on(this_cpu, &cpudata->hwp_notify_work, msecs_to_jiffies(10)); > +} > + > +static void intel_pstate_enable_hwp_interrupt(struct cpudata *cpudata) > +{ > + /* Enable HWP notification interrupt for guaranteed performance change */ > + if (boot_cpu_has(X86_FEATURE_HWP_NOTIFY)) { > + INIT_DELAYED_WORK(&cpudata->hwp_notify_work, intel_pstate_notify_work); > + wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x01); > + } > +} > + > static void intel_pstate_hwp_enable(struct cpudata *cpudata) > { > /* First disable HWP notification interrupt as we don't process them */ > @@ -1634,6 +1671,8 @@ static void intel_pstate_hwp_enable(struct cpudata *cpudata) > wrmsrl_on_cpu(cpudata->cpu, MSR_PM_ENABLE, 0x1); > if (cpudata->epp_default == -EINVAL) > cpudata->epp_default = intel_pstate_get_epp(cpudata, 0); > + > + intel_pstate_enable_hwp_interrupt(cpudata); > } > > static int atom_get_min_pstate(void) >
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