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cpufreq: amd-pstate: implement suspend and resume callbacks 

add suspend and resume support for the AMD processors by amd_pstate_epp
driver instance.

When the CPPC is suspended, EPP driver will set EPP profile to 'power'
profile and set max/min perf to lowest perf value.
When resume happens, it will restore the MSR registers with
previous cached value.

Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mario Limonciello <Mario.Limonciello@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Perry Yuan 2023-01-31 17:00:11 +08:00 committed by Rafael J. Wysocki
parent d4da12f803
commit 50ddd2f782
1 changed files with 40 additions and 0 deletions
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40
drivers/cpufreq/amd-pstate.c
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@ -1087,6 +1087,44 @@ static int amd_pstate_epp_verify_policy(struct cpufreq_policy_data *policy)
return 0; return 0;
} }
static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)
{
struct amd_cpudata *cpudata = policy->driver_data;
int ret;
/* avoid suspending when EPP is not enabled */
if (cppc_state != AMD_PSTATE_ACTIVE)
return 0;
/* set this flag to avoid setting core offline*/
cpudata->suspended = true;
/* disable CPPC in lowlevel firmware */
ret = amd_pstate_enable(false);
if (ret)
pr_err("failed to suspend, return %d\n", ret);
return 0;
}
static int amd_pstate_epp_resume(struct cpufreq_policy *policy)
{
struct amd_cpudata *cpudata = policy->driver_data;
if (cpudata->suspended) {
mutex_lock(&amd_pstate_limits_lock);
/* enable amd pstate from suspend state*/
amd_pstate_epp_reenable(cpudata);
mutex_unlock(&amd_pstate_limits_lock);
cpudata->suspended = false;
}
return 0;
}
static struct cpufreq_driver amd_pstate_driver = { static struct cpufreq_driver amd_pstate_driver = {
.flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS, .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS,
.verify = amd_pstate_verify, .verify = amd_pstate_verify,
@ -1108,6 +1146,8 @@ static struct cpufreq_driver amd_pstate_epp_driver = {
.exit = amd_pstate_epp_cpu_exit, .exit = amd_pstate_epp_cpu_exit,
.offline = amd_pstate_epp_cpu_offline, .offline = amd_pstate_epp_cpu_offline,
.online = amd_pstate_epp_cpu_online, .online = amd_pstate_epp_cpu_online,
.suspend = amd_pstate_epp_suspend,
.resume = amd_pstate_epp_resume,
.name = "amd_pstate_epp", .name = "amd_pstate_epp",
.attr = amd_pstate_epp_attr, .attr = amd_pstate_epp_attr,
}; };