From 988bed09d35a8533eb59868692b827dfae7b66fe Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Fri, 8 May 2015 11:53:45 +0530 Subject: [PATCH] cpufreq: Don't clear cpufreq_cpu_data and policy list for inactive policies Now that we can check policy->cpus to find if policy is active or not, we don't need to clean cpufreq_cpu_data and delete policy from the list on light weight tear down of policies (like in suspend). To make it consistent and clean, set cpufreq_cpu_data for all related CPUs when the policy is first created and clean it only while it is freed. Also update cpufreq_cpu_get_raw() to check if cpu is part of policy->cpus mask, so that we don't end up getting policies for offline CPUs. In order to make sure that no users of 'policy' are using an inactive policy, use cpufreq_cpu_get_raw() instead of directly accessing cpufreq_cpu_data. Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq.c | 79 +++++++++++++++++---------------------- 1 file changed, 34 insertions(+), 45 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 74d9fcbbe4f9..e899a5446d0e 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -239,10 +239,18 @@ int cpufreq_generic_init(struct cpufreq_policy *policy, } EXPORT_SYMBOL_GPL(cpufreq_generic_init); -unsigned int cpufreq_generic_get(unsigned int cpu) +/* Only for cpufreq core internal use */ +struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) { struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); + return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL; +} + +unsigned int cpufreq_generic_get(unsigned int cpu) +{ + struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu); + if (!policy || IS_ERR(policy->clk)) { pr_err("%s: No %s associated to cpu: %d\n", __func__, policy ? "clk" : "policy", cpu); @@ -253,12 +261,6 @@ unsigned int cpufreq_generic_get(unsigned int cpu) } EXPORT_SYMBOL_GPL(cpufreq_generic_get); -/* Only for cpufreq core internal use */ -struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) -{ - return per_cpu(cpufreq_cpu_data, cpu); -} - /** * cpufreq_cpu_get: returns policy for a cpu and marks it busy. * @@ -292,7 +294,7 @@ struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) if (cpufreq_driver) { /* get the CPU */ - policy = per_cpu(cpufreq_cpu_data, cpu); + policy = cpufreq_cpu_get_raw(cpu); if (policy) kobject_get(&policy->kobj); } @@ -1042,7 +1044,6 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu, struct device *dev) { int ret = 0; - unsigned long flags; /* Has this CPU been taken care of already? */ if (cpumask_test_cpu(cpu, policy->cpus)) @@ -1057,13 +1058,7 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, } down_write(&policy->rwsem); - - write_lock_irqsave(&cpufreq_driver_lock, flags); - cpumask_set_cpu(cpu, policy->cpus); - per_cpu(cpufreq_cpu_data, cpu) = policy; - write_unlock_irqrestore(&cpufreq_driver_lock, flags); - up_write(&policy->rwsem); if (has_target()) { @@ -1154,6 +1149,17 @@ static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) static void cpufreq_policy_free(struct cpufreq_policy *policy) { + unsigned long flags; + int cpu; + + /* Remove policy from list */ + write_lock_irqsave(&cpufreq_driver_lock, flags); + list_del(&policy->policy_list); + + for_each_cpu(cpu, policy->related_cpus) + per_cpu(cpufreq_cpu_data, cpu) = NULL; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + free_cpumask_var(policy->related_cpus); free_cpumask_var(policy->cpus); kfree(policy); @@ -1275,12 +1281,12 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) __func__, ret); goto err_init_policy_kobj; } - } - write_lock_irqsave(&cpufreq_driver_lock, flags); - for_each_cpu(j, policy->cpus) - per_cpu(cpufreq_cpu_data, j) = policy; - write_unlock_irqrestore(&cpufreq_driver_lock, flags); + write_lock_irqsave(&cpufreq_driver_lock, flags); + for_each_cpu(j, policy->related_cpus) + per_cpu(cpufreq_cpu_data, j) = policy; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + } if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { policy->cur = cpufreq_driver->get(policy->cpu); @@ -1339,11 +1345,11 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) goto err_out_unregister; blocking_notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_CREATE_POLICY, policy); - } - write_lock_irqsave(&cpufreq_driver_lock, flags); - list_add(&policy->policy_list, &cpufreq_policy_list); - write_unlock_irqrestore(&cpufreq_driver_lock, flags); + write_lock_irqsave(&cpufreq_driver_lock, flags); + list_add(&policy->policy_list, &cpufreq_policy_list); + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + } cpufreq_init_policy(policy); @@ -1367,11 +1373,6 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) err_out_unregister: err_get_freq: - write_lock_irqsave(&cpufreq_driver_lock, flags); - for_each_cpu(j, policy->cpus) - per_cpu(cpufreq_cpu_data, j) = NULL; - write_unlock_irqrestore(&cpufreq_driver_lock, flags); - if (!recover_policy) { kobject_put(&policy->kobj); wait_for_completion(&policy->kobj_unregister); @@ -1407,7 +1408,7 @@ static int __cpufreq_remove_dev_prepare(struct device *dev, write_lock_irqsave(&cpufreq_driver_lock, flags); - policy = per_cpu(cpufreq_cpu_data, cpu); + policy = cpufreq_cpu_get_raw(cpu); /* Save the policy somewhere when doing a light-weight tear-down */ if (cpufreq_suspended) @@ -1465,15 +1466,9 @@ static int __cpufreq_remove_dev_prepare(struct device *dev, static int __cpufreq_remove_dev_finish(struct device *dev, struct subsys_interface *sif) { - unsigned int cpu = dev->id, cpus; + unsigned int cpu = dev->id; int ret; - unsigned long flags; - struct cpufreq_policy *policy; - - write_lock_irqsave(&cpufreq_driver_lock, flags); - policy = per_cpu(cpufreq_cpu_data, cpu); - per_cpu(cpufreq_cpu_data, cpu) = NULL; - write_unlock_irqrestore(&cpufreq_driver_lock, flags); + struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu); if (!policy) { pr_debug("%s: No cpu_data found\n", __func__); @@ -1481,12 +1476,11 @@ static int __cpufreq_remove_dev_finish(struct device *dev, } down_write(&policy->rwsem); - cpus = cpumask_weight(policy->cpus); cpumask_clear_cpu(cpu, policy->cpus); up_write(&policy->rwsem); /* If cpu is last user of policy, free policy */ - if (cpus == 1) { + if (policy_is_inactive(policy)) { if (has_target()) { ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); @@ -1508,11 +1502,6 @@ static int __cpufreq_remove_dev_finish(struct device *dev, if (cpufreq_driver->exit) cpufreq_driver->exit(policy); - /* Remove policy from list of active policies */ - write_lock_irqsave(&cpufreq_driver_lock, flags); - list_del(&policy->policy_list); - write_unlock_irqrestore(&cpufreq_driver_lock, flags); - if (!cpufreq_suspended) cpufreq_policy_free(policy); } else if (has_target()) { -- 2.34.1