cpufreq/amd-pstate: Use scope based cleanup for cpufreq_policy refs

There have been instances in past where refcount decrementing is missed
while exiting a function. Use automatic scope based cleanup to avoid
such errors.

Signed-off-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20250205112523.201101-12-dhananjay.ugwekar@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 6a604f0797d9f16ead385274d9a802326bd4bb9c..ee7e3f0a4c0a360cf54427c36f6f0cc416628e5e 100644 (file)
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -548,7 +548,7 @@ static inline bool amd_pstate_sample(struct amd_cpudata *cpudata)
 static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf,
                              u8 des_perf, u8 max_perf, bool fast_switch, int gov_flags)
 {
-       struct cpufreq_policy *policy = cpufreq_cpu_get(cpudata->cpu);
+       struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpudata->cpu);
        u8 nominal_perf = READ_ONCE(cpudata->nominal_perf);
 
        if (!policy)
@@ -574,8 +574,6 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf,
        }
 
        amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, fast_switch);
-
-       cpufreq_cpu_put(policy);
 }
 
 static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
@@ -587,7 +585,8 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
         * amd-pstate qos_requests.
         */
        if (policy_data->min == FREQ_QOS_MIN_DEFAULT_VALUE) {
-               struct cpufreq_policy *policy = cpufreq_cpu_get(policy_data->cpu);
+               struct cpufreq_policy *policy __free(put_cpufreq_policy) =
+                                             cpufreq_cpu_get(policy_data->cpu);
                struct amd_cpudata *cpudata;
 
                if (!policy)
@@ -595,7 +594,6 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
 
                cpudata = policy->driver_data;
                policy_data->min = cpudata->lowest_nonlinear_freq;
-               cpufreq_cpu_put(policy);
        }
 
        cpufreq_verify_within_cpu_limits(policy_data);
@@ -678,7 +676,7 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
                                   unsigned long capacity)
 {
        u8 max_perf, min_perf, des_perf, cap_perf, min_limit_perf;
-       struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+       struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu);
        struct amd_cpudata *cpudata;
 
        if (!policy)
@@ -710,7 +708,6 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 
        amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true,
                        policy->governor->flags);
-       cpufreq_cpu_put(policy);
 }
 
 static int amd_pstate_cpu_boost_update(struct cpufreq_policy *policy, bool on)
@@ -824,28 +821,23 @@ static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata)
 
 static void amd_pstate_update_limits(unsigned int cpu)
 {
-       struct cpufreq_policy *policy = NULL;
+       struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu);
        struct amd_cpudata *cpudata;
        u32 prev_high = 0, cur_high = 0;
-       int ret;
        bool highest_perf_changed = false;
 
        if (!amd_pstate_prefcore)
                return;
 
-       policy = cpufreq_cpu_get(cpu);
        if (!policy)
                return;
 
-       cpudata = policy->driver_data;
-
        guard(mutex)(&amd_pstate_driver_lock);
 
-       ret = amd_get_highest_perf(cpu, &cur_high);
-       if (ret) {
-               cpufreq_cpu_put(policy);
+       if (amd_get_highest_perf(cpu, &cur_high))
                return;
-       }
+
+       cpudata = policy->driver_data;
 
        prev_high = READ_ONCE(cpudata->prefcore_ranking);
        highest_perf_changed = (prev_high != cur_high);
@@ -855,7 +847,6 @@ static void amd_pstate_update_limits(unsigned int cpu)
                if (cur_high < CPPC_MAX_PERF)
                        sched_set_itmt_core_prio((int)cur_high, cpu);
        }
-       cpufreq_cpu_put(policy);
 }
 
 /*

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 7fe0981a7e4674f801201c11e7ebaf9c1b9e34d9..dde5212d256cf176b09836cee3b54a33350f9697 100644 (file)
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -210,6 +210,9 @@ static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
 #endif
 
+/* Scope based cleanup macro for cpufreq_policy kobject reference counting */
+DEFINE_FREE(put_cpufreq_policy, struct cpufreq_policy *, if (_T) cpufreq_cpu_put(_T))
+
 static inline bool policy_is_inactive(struct cpufreq_policy *policy)
 {
        return cpumask_empty(policy->cpus);