cpufreq: intel_pstate: Add base_frequency attribute (86d333a8) · Commits · 戴 / test

Expose base_frequency to user space via cpufreq sysfs when HWP is in use. This HWP base frequency is read from the ACPI _CPC object if present, or from the HWP Capabilities MSR otherwise. On the majority of the HWP platforms the _CPC object will point to the HWP Capabilities MSR using the "Functional Fixed Hardware" address space type. The address space type also can simply be ACPI_TYPE_INTEGER, however, in which case the platform firmware can set its value at the initialization time based on the system constraints. Signed-off-by:

Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> [ rjw: Changelog ] Signed-off-by:

Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/intel_pstate.c

+38 −0

Original line number	Diff line number	Diff line
		@@ -373,10 +373,28 @@ static void intel_pstate_set_itmt_prio(int cpu)
		}
		}
		}

		static int intel_pstate_get_cppc_guranteed(int cpu)
		{
		struct cppc_perf_caps cppc_perf;
		int ret;

		ret = cppc_get_perf_caps(cpu, &cppc_perf);
		if (ret)
		return ret;

		return cppc_perf.guaranteed_perf;
		}

		#else
		static void intel_pstate_set_itmt_prio(int cpu)
		{
		}

		static int intel_pstate_get_cppc_guranteed(int cpu)
		{
		return -ENOTSUPP;
		}
		#endif

		static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
		@@ -699,9 +717,29 @@ static ssize_t show_energy_performance_preference(

		cpufreq_freq_attr_rw(energy_performance_preference);

		static ssize_t show_base_frequency(struct cpufreq_policy policy, char buf)
		{
		struct cpudata *cpu;
		u64 cap;
		int ratio;

		ratio = intel_pstate_get_cppc_guranteed(policy->cpu);
		if (ratio <= 0) {
		rdmsrl_on_cpu(policy->cpu, MSR_HWP_CAPABILITIES, &cap);
		ratio = HWP_GUARANTEED_PERF(cap);
		}

		cpu = all_cpu_data[policy->cpu];

		return sprintf(buf, "%d\n", ratio * cpu->pstate.scaling);
		}

		cpufreq_freq_attr_ro(base_frequency);

		static struct freq_attr *hwp_cpufreq_attrs[] = {
		&energy_performance_preference,
		&energy_performance_available_preferences,
		&base_frequency,
		NULL,
		};

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