cpufreq/intel_pstate: Use CPPC to get max performance
Use the acpi cppc_lib interface to get CPPC performance limits and update
the per cpu priority for the ITMT scheduler. If the highest performance of
CPUs differs the ITMT feature is enabled.
Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-pm@vger.kernel.org
Cc: peterz@infradead.org
Cc: jolsa@redhat.com
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/0998b98943bcdec7d1ddd4ff27358da555ea8e92.1479844244.git.tim.c.chen@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 4737520..e8dc42f 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -44,6 +44,7 @@
#ifdef CONFIG_ACPI
#include <acpi/processor.h>
+#include <acpi/cppc_acpi.h>
#endif
#define FRAC_BITS 8
@@ -379,14 +380,67 @@
return acpi_ppc;
}
+#ifdef CONFIG_ACPI_CPPC_LIB
+
+/* The work item is needed to avoid CPU hotplug locking issues */
+static void intel_pstste_sched_itmt_work_fn(struct work_struct *work)
+{
+ sched_set_itmt_support();
+}
+
+static DECLARE_WORK(sched_itmt_work, intel_pstste_sched_itmt_work_fn);
+
+static void intel_pstate_set_itmt_prio(int cpu)
+{
+ struct cppc_perf_caps cppc_perf;
+ static u32 max_highest_perf = 0, min_highest_perf = U32_MAX;
+ int ret;
+
+ ret = cppc_get_perf_caps(cpu, &cppc_perf);
+ if (ret)
+ return;
+
+ /*
+ * The priorities can be set regardless of whether or not
+ * sched_set_itmt_support(true) has been called and it is valid to
+ * update them at any time after it has been called.
+ */
+ sched_set_itmt_core_prio(cppc_perf.highest_perf, cpu);
+
+ if (max_highest_perf <= min_highest_perf) {
+ if (cppc_perf.highest_perf > max_highest_perf)
+ max_highest_perf = cppc_perf.highest_perf;
+
+ if (cppc_perf.highest_perf < min_highest_perf)
+ min_highest_perf = cppc_perf.highest_perf;
+
+ if (max_highest_perf > min_highest_perf) {
+ /*
+ * This code can be run during CPU online under the
+ * CPU hotplug locks, so sched_set_itmt_support()
+ * cannot be called from here. Queue up a work item
+ * to invoke it.
+ */
+ schedule_work(&sched_itmt_work);
+ }
+ }
+}
+#else
+static void intel_pstate_set_itmt_prio(int cpu)
+{
+}
+#endif
+
static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
{
struct cpudata *cpu;
int ret;
int i;
- if (hwp_active)
+ if (hwp_active) {
+ intel_pstate_set_itmt_prio(policy->cpu);
return;
+ }
if (!intel_pstate_get_ppc_enable_status())
return;