diff options
| author | Perry Yuan <Perry.Yuan@amd.com> | 2023-01-31 12:00:11 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2023-02-03 23:59:42 +0300 |
| commit | 50ddd2f7826927e6dc111a43b3a183f53c260fa4 (patch) | |
| tree | fe0477a57bca5aa1575c3c2068ad854c8826ae11 /drivers/cpufreq | |
| parent | d4da12f8033a123353eccf993cb95ee5bff21e7c (diff) | |
| download | linux-50ddd2f7826927e6dc111a43b3a183f53c260fa4.tar.xz | |
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>
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/amd-pstate.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 26f6ac83d87e..4e3770e0d4d3 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -1087,6 +1087,44 @@ static int amd_pstate_epp_verify_policy(struct cpufreq_policy_data *policy) 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 = { .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS, .verify = amd_pstate_verify, @@ -1108,6 +1146,8 @@ static struct cpufreq_driver amd_pstate_epp_driver = { .exit = amd_pstate_epp_cpu_exit, .offline = amd_pstate_epp_cpu_offline, .online = amd_pstate_epp_cpu_online, + .suspend = amd_pstate_epp_suspend, + .resume = amd_pstate_epp_resume, .name = "amd_pstate_epp", .attr = amd_pstate_epp_attr, }; |