From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Subject: cpufreq: intel_pstate: Add base_frequency attribute
References: fate#326883
Patch-Mainline: v4.20-rc1
Git-commit: 86d333a8cc7f66c2314ab1e147834a1cd95ec2de
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>
Signed-off-by: Thomas Renninger <trenn@suse.com>
---
drivers/cpufreq/intel_pstate.c | 38 ++++++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -433,10 +433,28 @@ static void intel_pstate_set_itmt_prio(i
}
}
}
+
+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)
@@ -812,9 +830,29 @@ static ssize_t show_energy_performance_p
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,
};