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 <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/Documentation/cpu-freq/intel-pstate.txt b/Documentation/cpu-freq/intel-pstate.txt
index 7767ce6756beb1166ef805a66a5d5d431c500eb6..655750743fb09b3c78a8b5c47cc96ace7b311722 100644 (file)
--- 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.
 
       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
 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 ed6dd7dac094fc91ca3c5fb3a2bb1085e93147b1..80ecc351d613a68788c57e6a3ee625d35d2ecefa 100644 (file)
--- 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);
 }
 
        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)
 {
 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_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,
 
 static struct attribute *intel_pstate_attributes[] = {
        &no_turbo.attr,
        &max_perf_pct.attr,
        &min_perf_pct.attr,
        &turbo_pct.attr,

+       &num_pstates.attr,

        NULL
 };
 
        NULL
 };