diff mbox series

[v8,08/13] cpufreq: amd-pstate: implement suspend and resume callbacks

Message ID 20221219064042.661122-9-perry.yuan@amd.com
State New
Headers
Series Implement AMD Pstate EPP Driver |

Commit Message

Yuan, Perry Dec. 19, 2022, 6:40 a.m. UTC 
  From: Perry Yuan <Perry.Yuan@amd.com>

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.

Reviewed-by: Mario Limonciello <Mario.Limonciello@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 41 ++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

Comments

Huang Rui Dec. 23, 2022, 8:12 a.m. UTC | #1 
On Mon, Dec 19, 2022 at 02:40:37PM +0800, Yuan, Perry wrote:
> From: Perry Yuan <Perry.Yuan@amd.com>
> 
> 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.
> 
> Reviewed-by: Mario Limonciello <Mario.Limonciello@amd.com>
> Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>

Acked-by: Huang Rui <ray.huang@amd.com>

> ---
>  drivers/cpufreq/amd-pstate.c | 41 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 41 insertions(+)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index cb647f55a169..fc12d35bc7bd 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1107,6 +1107,45 @@ 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 = all_cpu_data[policy->cpu];
> +        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 = all_cpu_data[policy->cpu];
> +
> +        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,
> @@ -1129,6 +1168,8 @@ static struct cpufreq_driver amd_pstate_epp_driver = {
>  	.update_limits	= amd_pstate_epp_update_limits,
>  	.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,
>  };
> -- 
> 2.34.1
>
diff mbox series

Patch

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index cb647f55a169..fc12d35bc7bd 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1107,6 +1107,45 @@  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 = all_cpu_data[policy->cpu];
+        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 = all_cpu_data[policy->cpu];
+
+        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,
@@ -1129,6 +1168,8 @@  static struct cpufreq_driver amd_pstate_epp_driver = {
 	.update_limits	= amd_pstate_epp_update_limits,
 	.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,
 };