powercap: add suspend and resume mechanism for SOC power limit
PL1 and PL2 could be throlled or de-throttled by
Thermal management to control SOC temperature.
However, currently, their value will be reset to default value
after once system suspend and resume.
Add pm_notifier to save PL1, PL2 before system suspect and restore
PL1, PL2 after system resume.
Signed-off-by: Zhen Han <zhen.han@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/powercap/intel_rapl.c b/drivers/powercap/intel_rapl.c
index d1694f1..0188cff 100644
--- a/drivers/powercap/intel_rapl.c
+++ b/drivers/powercap/intel_rapl.c
@@ -29,6 +29,7 @@
#include <linux/sysfs.h>
#include <linux/cpu.h>
#include <linux/powercap.h>
+#include <linux/suspend.h>
#include <asm/iosf_mbi.h>
#include <asm/processor.h>
@@ -155,6 +156,7 @@ struct rapl_power_limit {
int prim_id; /* primitive ID used to enable */
struct rapl_domain *domain;
const char *name;
+ u64 last_power_limit;
};
static const char pl1_name[] = "long_term";
@@ -1533,6 +1535,92 @@ static int rapl_cpu_down_prep(unsigned int cpu)
static enum cpuhp_state pcap_rapl_online;
+static void power_limit_state_save(void)
+{
+ struct rapl_package *rp;
+ struct rapl_domain *rd;
+ int nr_pl, ret, i;
+
+ get_online_cpus();
+ list_for_each_entry(rp, &rapl_packages, plist) {
+ if (!rp->power_zone)
+ continue;
+ rd = power_zone_to_rapl_domain(rp->power_zone);
+ nr_pl = find_nr_power_limit(rd);
+ for (i = 0; i < nr_pl; i++) {
+ switch (rd->rpl[i].prim_id) {
+ case PL1_ENABLE:
+ ret = rapl_read_data_raw(rd,
+ POWER_LIMIT1,
+ true,
+ &rd->rpl[i].last_power_limit);
+ if (ret)
+ rd->rpl[i].last_power_limit = 0;
+ break;
+ case PL2_ENABLE:
+ ret = rapl_read_data_raw(rd,
+ POWER_LIMIT2,
+ true,
+ &rd->rpl[i].last_power_limit);
+ if (ret)
+ rd->rpl[i].last_power_limit = 0;
+ break;
+ }
+ }
+ }
+ put_online_cpus();
+}
+
+static void power_limit_state_restore(void)
+{
+ struct rapl_package *rp;
+ struct rapl_domain *rd;
+ int nr_pl, i;
+
+ get_online_cpus();
+ list_for_each_entry(rp, &rapl_packages, plist) {
+ if (!rp->power_zone)
+ continue;
+ rd = power_zone_to_rapl_domain(rp->power_zone);
+ nr_pl = find_nr_power_limit(rd);
+ for (i = 0; i < nr_pl; i++) {
+ switch (rd->rpl[i].prim_id) {
+ case PL1_ENABLE:
+ if (rd->rpl[i].last_power_limit)
+ rapl_write_data_raw(rd,
+ POWER_LIMIT1,
+ rd->rpl[i].last_power_limit);
+ break;
+ case PL2_ENABLE:
+ if (rd->rpl[i].last_power_limit)
+ rapl_write_data_raw(rd,
+ POWER_LIMIT2,
+ rd->rpl[i].last_power_limit);
+ break;
+ }
+ }
+ }
+ put_online_cpus();
+}
+
+static int rapl_pm_callback(struct notifier_block *nb,
+ unsigned long mode, void *_unused)
+{
+ switch (mode) {
+ case PM_SUSPEND_PREPARE:
+ power_limit_state_save();
+ break;
+ case PM_POST_SUSPEND:
+ power_limit_state_restore();
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block rapl_pm_notifier = {
+ .notifier_call = rapl_pm_callback,
+};
+
static int __init rapl_init(void)
{
const struct x86_cpu_id *id;
@@ -1560,8 +1648,16 @@ static int __init rapl_init(void)
/* Don't bail out if PSys is not supported */
rapl_register_psys();
+
+ ret = register_pm_notifier(&rapl_pm_notifier);
+ if (ret)
+ goto err_unreg_all;
+
return 0;
+err_unreg_all:
+ cpuhp_remove_state(pcap_rapl_online);
+
err_unreg:
rapl_unregister_powercap();
return ret;
@@ -1569,6 +1665,7 @@ static int __init rapl_init(void)
static void __exit rapl_exit(void)
{
+ unregister_pm_notifier(&rapl_pm_notifier);
cpuhp_remove_state(pcap_rapl_online);
rapl_unregister_powercap();
}