diff options
| author | Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | 2018-10-15 10:37:20 -0700 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2018-10-16 10:33:39 +0200 |
| commit | 86d333a8cc7f66c2314ab1e147834a1cd95ec2de (patch) | |
| tree | 136188373a393aee5ecea86119fa20275716d5bf /drivers/cpufreq | |
| parent | 29523f095397637edca60c627bc3e5c25a02c40f (diff) | |
| download | linux-86d333a8cc7f66c2314ab1e147834a1cd95ec2de.tar.bz2 | |
cpufreq: intel_pstate: Add base_frequency attribute
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>
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index b6a1aadaff9f..2a99e2fd9412 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -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, }; |