From 0522424ecb333c0874c4e74bc053dd662bed40df Mon Sep 17 00:00:00 2001 From: Kristen Carlson Accardi Date: Wed, 28 Jan 2015 15:03:28 -0800 Subject: [PATCH] intel_pstate: Add num_pstates to sysfs Add a sysfs interface to display the total number of supported pstates. This value is independent of whether turbo has been enabled or disabled. Signed-off-by: Kristen Carlson Accardi Signed-off-by: Rafael J. Wysocki --- Documentation/cpu-freq/intel-pstate.txt | 4 ++++ drivers/cpufreq/intel_pstate.c | 13 +++++++++++++ 2 files changed, 17 insertions(+) diff --git a/Documentation/cpu-freq/intel-pstate.txt b/Documentation/cpu-freq/intel-pstate.txt index 7767ce6756be..655750743fb0 100644 --- a/Documentation/cpu-freq/intel-pstate.txt +++ b/Documentation/cpu-freq/intel-pstate.txt @@ -41,6 +41,10 @@ controlling P state selection. These files have been added to is supported by hardware that is in the turbo range. This number is independent of whether turbo has been disabled or not. + num_pstates: displays the number of pstates that are supported + by hardware. This number is independent of whether turbo has + been disabled or not. + For contemporary Intel processors, the frequency is controlled by the processor itself and the P-states exposed to software are related to performance levels. The idea that frequency can be set to a single diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index ed6dd7dac094..80ecc351d613 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -354,6 +354,17 @@ static ssize_t show_turbo_pct(struct kobject *kobj, return sprintf(buf, "%u\n", turbo_pct); } +static ssize_t show_num_pstates(struct kobject *kobj, + struct attribute *attr, char *buf) +{ + struct cpudata *cpu; + int total; + + cpu = all_cpu_data[0]; + total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1; + return sprintf(buf, "%u\n", total); +} + static ssize_t show_no_turbo(struct kobject *kobj, struct attribute *attr, char *buf) { @@ -435,12 +446,14 @@ define_one_global_rw(no_turbo); define_one_global_rw(max_perf_pct); define_one_global_rw(min_perf_pct); define_one_global_ro(turbo_pct); +define_one_global_ro(num_pstates); static struct attribute *intel_pstate_attributes[] = { &no_turbo.attr, &max_perf_pct.attr, &min_perf_pct.attr, &turbo_pct.attr, + &num_pstates.attr, NULL };