From ab0520499c83ff44d468f1b2b604c85e2f78d694 Mon Sep 17 00:00:00 2001 From: Dhananjay Ugwekar Date: Wed, 5 Feb 2025 11:25:22 +0000 Subject: 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 Reviewed-by: Mario Limonciello --- drivers/cpufreq/amd-pstate.c | 25 ++++++++----------------- include/linux/cpufreq.h | 3 +++ 2 files changed, 11 insertions(+), 17 deletions(-) --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -548,7 +548,7 @@ static inline bool amd_pstate_sample(str 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 } 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 cpuf * 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 cpuf 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(unsig 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(unsig 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) @@ -823,28 +820,23 @@ static void amd_pstate_init_prefcore(str 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); @@ -854,7 +846,6 @@ static void amd_pstate_update_limits(uns if (cur_high < CPPC_MAX_PERF) sched_set_itmt_core_prio((int)cur_high, cpu); } - cpufreq_cpu_put(policy); } /* --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -213,6 +213,9 @@ static inline struct cpufreq_policy *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);