From: "Rafael J. Wysocki" <rafael.j.wyso...@intel.com>
This change uses acpi cppc_lib interface to get CPPC performance limits
and calls scheduler interface to update per cpu highest priority. If
there is a difference in highest performance of each CPUs, call scheduler
interface to enable ITMT feature for only one time.
Here sched_set_itmt_core_prio() is called to set priorities and
sched_set_itmt_support() is called to enable ITMT feature.
Original-by: Srinivas Pandruvada <srinivas.pandruv...@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruv...@linux.intel.com>
---
drivers/cpufreq/Kconfig.x86 | 1 +
drivers/cpufreq/intel_pstate.c | 56 +++++++++++++++++++++++++++++++++++++++++-
2 files changed, 56 insertions(+), 1 deletion(-)
diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86
index adbd1de..c6d273b 100644
--- a/drivers/cpufreq/Kconfig.x86
+++ b/drivers/cpufreq/Kconfig.x86
@@ -6,6 +6,7 @@ config X86_INTEL_PSTATE
bool "Intel P state control"
depends on X86
select ACPI_PROCESSOR if ACPI
+ select ACPI_CPPC_LIB if X86_64 && ACPI && SCHED_ITMT
help
This driver provides a P state for Intel core processors.
The driver implements an internal governor and will become
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index c877e70..e135cef 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
@@ -377,14 +378,67 @@ static bool intel_pstate_get_ppc_enable_status(void)
return acpi_ppc;
}
+#ifdef CONFIG_SCHED_ITMT
+
+/* 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(true);
+}
+
+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;
--
2.7.4
