intel_pstate: expose turbo range to sysfs

This patch adds "turbo_pct" to the intel_pstate sysfs interface.
turbo_pct will display the percentage of the total supported
pstates that are in the turbo range.  This value is independent
of whether turbo has been disabled or not.

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 765d7fc0e692182a6c9952f4a023eed553883612..7767ce6756beb1166ef805a66a5d5d431c500eb6 100644 (file)
--- a/Documentation/cpu-freq/intel-pstate.txt
+++ b/Documentation/cpu-freq/intel-pstate.txt
@@ -37,6 +37,10 @@ controlling P state selection. These files have been added to
       no_turbo: limits the driver to selecting P states below the turbo
       frequency range.
 
+      turbo_pct: displays the percentage of the total performance that
+      is supported by hardware that is in the turbo range.  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 7d9f822f2031a944211722d35b592918fe55574a..ed6dd7dac094fc91ca3c5fb3a2bb1085e93147b1 100644 (file)
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -338,6 +338,22 @@ static void __init intel_pstate_debug_expose_params(void)
                return sprintf(buf, "%u\n", limits.object);             \
        }
 
+static ssize_t show_turbo_pct(struct kobject *kobj,
+                               struct attribute *attr, char *buf)
+{
+       struct cpudata *cpu;
+       int total, no_turbo, turbo_pct;
+       uint32_t turbo_fp;
+
+       cpu = all_cpu_data[0];
+
+       total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
+       no_turbo = cpu->pstate.max_pstate - cpu->pstate.min_pstate + 1;
+       turbo_fp = div_fp(int_tofp(no_turbo), int_tofp(total));
+       turbo_pct = 100 - fp_toint(mul_fp(turbo_fp, int_tofp(100)));
+       return sprintf(buf, "%u\n", turbo_pct);
+}
+
 static ssize_t show_no_turbo(struct kobject *kobj,
                             struct attribute *attr, char *buf)
 {
@@ -418,11 +434,13 @@ show_one(min_perf_pct, min_perf_pct);
 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);
 
 static struct attribute *intel_pstate_attributes[] = {
        &no_turbo.attr,
        &max_perf_pct.attr,
        &min_perf_pct.attr,
+       &turbo_pct.attr,
        NULL
 };