Commit 52b3672c authored by Zhen Han's avatar Zhen Han Committed by Rafael J. Wysocki

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: 's avatarZhen Han <zhen.han@intel.com>
Signed-off-by: 's avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 7f634489
......@@ -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();
}
......
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