cpufreq/amd-pstate: convert mutex use to guard()

Using scoped guard declaration will unlock mutexes automatically.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20241209185248.16301-5-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

Author: superm1

drivers/cpufreq/amd-pstate.c

@@ -758,12 +758,12 @@ static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
 		pr_err("Boost mode is not supported by this processor or SBIOS\n");
 		return -EOPNOTSUPP;
 	}
-	mutex_lock(&amd_pstate_driver_lock);
+	guard(mutex)(&amd_pstate_driver_lock);
+
 	ret = amd_pstate_cpu_boost_update(policy, state);
 	WRITE_ONCE(cpudata->boost_state, !ret ? state : false);
 	policy->boost_enabled = !ret ? state : false;
 	refresh_frequency_limits(policy);
-	mutex_unlock(&amd_pstate_driver_lock);
 
 	return ret;
 }
@@ -854,7 +854,8 @@ static void amd_pstate_update_limits(unsigned int cpu)
 	if (!amd_pstate_prefcore)
 		return;
 
-	mutex_lock(&amd_pstate_driver_lock);
+	guard(mutex)(&amd_pstate_driver_lock);
+
 	ret = amd_get_highest_perf(cpu, &cur_high);
 	if (ret)
 		goto free_cpufreq_put;
@@ -874,7 +875,6 @@ static void amd_pstate_update_limits(unsigned int cpu)
 	if (!highest_perf_changed)
 		cpufreq_update_policy(cpu);
 
-	mutex_unlock(&amd_pstate_driver_lock);
 }
 
 /*
@@ -1203,11 +1203,11 @@ static ssize_t store_energy_performance_preference(
 	if (ret < 0)
 		return -EINVAL;
 
-	mutex_lock(&amd_pstate_limits_lock);
+	guard(mutex)(&amd_pstate_limits_lock);
+
 	ret = amd_pstate_set_energy_pref_index(cpudata, ret);
-	mutex_unlock(&amd_pstate_limits_lock);
 
-	return ret ?: count;
+	return ret ? ret : count;
 }
 
 static ssize_t show_energy_performance_preference(
@@ -1371,13 +1371,10 @@ EXPORT_SYMBOL_GPL(amd_pstate_update_status);
 static ssize_t status_show(struct device *dev,
 			   struct device_attribute *attr, char *buf)
 {
-	ssize_t ret;
 
-	mutex_lock(&amd_pstate_driver_lock);
-	ret = amd_pstate_show_status(buf);
-	mutex_unlock(&amd_pstate_driver_lock);
+	guard(mutex)(&amd_pstate_driver_lock);
 
-	return ret;
+	return amd_pstate_show_status(buf);
 }
 
 static ssize_t status_store(struct device *a, struct device_attribute *b,
@@ -1386,9 +1383,8 @@ static ssize_t status_store(struct device *a, struct device_attribute *b,
 	char *p = memchr(buf, '\n', count);
 	int ret;
 
-	mutex_lock(&amd_pstate_driver_lock);
+	guard(mutex)(&amd_pstate_driver_lock);
 	ret = amd_pstate_update_status(buf, p ? p - buf : count);
-	mutex_unlock(&amd_pstate_driver_lock);
 
 	return ret < 0 ? ret : count;
 }
@@ -1689,7 +1685,7 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
 
 	min_perf = READ_ONCE(cpudata->lowest_perf);
 
-	mutex_lock(&amd_pstate_limits_lock);
+	guard(mutex)(&amd_pstate_limits_lock);
 
 	if (trace_amd_pstate_epp_perf_enabled()) {
 		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
@@ -1700,8 +1696,6 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
 	amd_pstate_update_perf(cpudata, min_perf, 0, min_perf, false);
 	amd_pstate_set_epp(cpudata, AMD_CPPC_EPP_BALANCE_POWERSAVE);
 
-	mutex_unlock(&amd_pstate_limits_lock);
-
 	return 0;
 }
 
@@ -1730,13 +1724,11 @@ 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);
+		guard(mutex)(&amd_pstate_limits_lock);
 
 		/* enable amd pstate from suspend state*/
 		amd_pstate_epp_reenable(cpudata);
 
-		mutex_unlock(&amd_pstate_limits_lock);
-
 		cpudata->suspended = false;
 	}