| Message ID | 20240618035122.438822-3-srinivas.pandruvada@linux.intel.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | Update highest frequency of a CPU after boot | expand |
On Mon, Jun 17, 2024 at 08:51:21PM -0700, Srinivas Pandruvada wrote: > + status_mask = HWP_GUARANTEED_PERF_CHANGE_STATUS; > + if (boot_cpu_has(X86_FEATURE_HWP_HIGHEST_PERF_CHANGE)) s/boot_cpu_has/cpu_feature_enabled/g > + status_mask |= HWP_HIGHEST_PERF_CHANGE_STATUS; > + > rdmsrl_safe(MSR_HWP_STATUS, &value); > - if (!(value & 0x01)) > + if (!(value & status_mask)) > return; > > spin_lock_irqsave(&hwp_notify_lock, flags); > @@ -1668,17 +1675,25 @@ static void intel_pstate_disable_hwp_interrupt(struct cpudata *cpudata) > cancel_delayed_work_sync(&cpudata->hwp_notify_work); > } > > +#define HWP_GUARANTEED_PERF_CHANGE_REQ BIT(0) > +#define HWP_HIGHEST_PERF_CHANGE_REQ BIT(2) > + > static void intel_pstate_enable_hwp_interrupt(struct cpudata *cpudata) > { > - /* Enable HWP notification interrupt for guaranteed performance change */ > + /* Enable HWP notification interrupt for performance change */ > if (boot_cpu_has(X86_FEATURE_HWP_NOTIFY)) { > + u64 interrupt_mask = HWP_GUARANTEED_PERF_CHANGE_REQ; > + > spin_lock_irq(&hwp_notify_lock); > INIT_DELAYED_WORK(&cpudata->hwp_notify_work, intel_pstate_notify_work); > cpumask_set_cpu(cpudata->cpu, &hwp_intr_enable_mask); > spin_unlock_irq(&hwp_notify_lock); > > + if (boot_cpu_has(X86_FEATURE_HWP_HIGHEST_PERF_CHANGE))a Ditto.
Hi Borislav, On Tue, 2024-06-18 at 11:08 +0200, Borislav Petkov wrote: > On Mon, Jun 17, 2024 at 08:51:21PM -0700, Srinivas Pandruvada wrote: > > + status_mask = HWP_GUARANTEED_PERF_CHANGE_STATUS; > > + if (boot_cpu_has(X86_FEATURE_HWP_HIGHEST_PERF_CHANGE)) > > s/boot_cpu_has/cpu_feature_enabled/g I will change in V2 > > + status_mask |= HWP_HIGHEST_PERF_CHANGE_STATUS; > > + > > rdmsrl_safe(MSR_HWP_STATUS, &value); > > - if (!(value & 0x01)) > > + if (!(value & status_mask)) > > return; > > > > spin_lock_irqsave(&hwp_notify_lock, flags); > > @@ -1668,17 +1675,25 @@ static void > > intel_pstate_disable_hwp_interrupt(struct cpudata *cpudata) > > cancel_delayed_work_sync(&cpudata- > > >hwp_notify_work); > > } > > > > +#define HWP_GUARANTEED_PERF_CHANGE_REQ BIT(0) > > +#define HWP_HIGHEST_PERF_CHANGE_REQ BIT(2) > > + > > static void intel_pstate_enable_hwp_interrupt(struct cpudata > > *cpudata) > > { > > - /* Enable HWP notification interrupt for guaranteed > > performance change */ > > + /* Enable HWP notification interrupt for performance change > > */ > > if (boot_cpu_has(X86_FEATURE_HWP_NOTIFY)) { > > + u64 interrupt_mask = > > HWP_GUARANTEED_PERF_CHANGE_REQ; > > + > > spin_lock_irq(&hwp_notify_lock); > > INIT_DELAYED_WORK(&cpudata->hwp_notify_work, > > intel_pstate_notify_work); > > cpumask_set_cpu(cpudata->cpu, > > &hwp_intr_enable_mask); > > spin_unlock_irq(&hwp_notify_lock); > > > > + if > > (boot_cpu_has(X86_FEATURE_HWP_HIGHEST_PERF_CHANGE))a > > Ditto. Will change in v2. Thanks, Srinivas
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 69d85b5bf366..708e62080a83 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1620,17 +1620,24 @@ static void intel_pstate_notify_work(struct work_struct *work) static DEFINE_SPINLOCK(hwp_notify_lock); static cpumask_t hwp_intr_enable_mask; +#define HWP_GUARANTEED_PERF_CHANGE_STATUS BIT(0) +#define HWP_HIGHEST_PERF_CHANGE_STATUS BIT(3) + void notify_hwp_interrupt(void) { unsigned int this_cpu = smp_processor_id(); + u64 value, status_mask; unsigned long flags; - u64 value; if (!hwp_active || !boot_cpu_has(X86_FEATURE_HWP_NOTIFY)) return; + status_mask = HWP_GUARANTEED_PERF_CHANGE_STATUS; + if (boot_cpu_has(X86_FEATURE_HWP_HIGHEST_PERF_CHANGE)) + status_mask |= HWP_HIGHEST_PERF_CHANGE_STATUS; + rdmsrl_safe(MSR_HWP_STATUS, &value); - if (!(value & 0x01)) + if (!(value & status_mask)) return; spin_lock_irqsave(&hwp_notify_lock, flags); @@ -1668,17 +1675,25 @@ static void intel_pstate_disable_hwp_interrupt(struct cpudata *cpudata) cancel_delayed_work_sync(&cpudata->hwp_notify_work); } +#define HWP_GUARANTEED_PERF_CHANGE_REQ BIT(0) +#define HWP_HIGHEST_PERF_CHANGE_REQ BIT(2) + static void intel_pstate_enable_hwp_interrupt(struct cpudata *cpudata) { - /* Enable HWP notification interrupt for guaranteed performance change */ + /* Enable HWP notification interrupt for performance change */ if (boot_cpu_has(X86_FEATURE_HWP_NOTIFY)) { + u64 interrupt_mask = HWP_GUARANTEED_PERF_CHANGE_REQ; + spin_lock_irq(&hwp_notify_lock); INIT_DELAYED_WORK(&cpudata->hwp_notify_work, intel_pstate_notify_work); cpumask_set_cpu(cpudata->cpu, &hwp_intr_enable_mask); spin_unlock_irq(&hwp_notify_lock); + if (boot_cpu_has(X86_FEATURE_HWP_HIGHEST_PERF_CHANGE)) + interrupt_mask |= HWP_HIGHEST_PERF_CHANGE_REQ; + /* wrmsrl_on_cpu has to be outside spinlock as this can result in IPC */ - wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x01); + wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, interrupt_mask); wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_STATUS, 0); } }
On some systems, the HWP (Hardware P-states) highest performance level can change from the value set at boot-up. This behavior can lead to two issues: - The 'cpuinfo_max_freq' within the 'cpufreq' sysfs will not reflect the CPU's highest achievable performance. - Even if the CPU's highest performance level is increased after booting, the CPU may not reach the full expected performance. The availability of this feature is indicated by the CPUID instruction: if CPUID[6].EAX[15] is set to 1, the feature is supported. When supported, setting bit 2 of the MSR_HWP_INTERRUPT register enables notifications of the highest performance level changes. Therefore, as part of enabling the HWP interrupt, bit 2 of the MSR_HWP_INTERRUPT should also be set when this feature is supported. Upon a change in the highest performance level, a new HWP interrupt is generated, with bit 3 of the MSR_HWP_STATUS register set, and the MSR_HWP_CAPABILITIES register is updated with the new highest performance limit. The processing of the interrupt is the same as the guaranteed performance change. Notify change to cpufreq core and update MSR_HWP_REQUEST with new performance limits. The current driver implementation already takes care of the highest performance change as part of: commit dfeeedc1bf57 ("cpufreq: intel_pstate: Update cpuinfo.max_freq on HWP_CAP changes") For example: Before highest performance change interrupt: cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq 3700000 cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq 3700000 After highest performance changes interrupt: cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq 3900000 cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq 3900000 Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> --- drivers/cpufreq/intel_pstate.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-)