diff options
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 220 |
1 files changed, 135 insertions, 85 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 16214dfe78c5..4bfe0a53502f 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -957,28 +957,67 @@ void cpufreq_sysfs_remove_file(const struct attribute *attr) } EXPORT_SYMBOL(cpufreq_sysfs_remove_file); -/* symlink affected CPUs */ +static int add_cpu_dev_symlink(struct cpufreq_policy *policy, int cpu) +{ + struct device *cpu_dev; + + pr_debug("%s: Adding symlink for CPU: %u\n", __func__, cpu); + + if (!policy) + return 0; + + cpu_dev = get_cpu_device(cpu); + if (WARN_ON(!cpu_dev)) + return 0; + + return sysfs_create_link(&cpu_dev->kobj, &policy->kobj, "cpufreq"); +} + +static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, int cpu) +{ + struct device *cpu_dev; + + pr_debug("%s: Removing symlink for CPU: %u\n", __func__, cpu); + + cpu_dev = get_cpu_device(cpu); + if (WARN_ON(!cpu_dev)) + return; + + sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); +} + +/* Add/remove symlinks for all related CPUs */ static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) { unsigned int j; int ret = 0; - for_each_cpu(j, policy->cpus) { - struct device *cpu_dev; - + /* Some related CPUs might not be present (physically hotplugged) */ + for_each_cpu_and(j, policy->related_cpus, cpu_present_mask) { if (j == policy->kobj_cpu) continue; - pr_debug("Adding link for CPU: %u\n", j); - cpu_dev = get_cpu_device(j); - ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, - "cpufreq"); + ret = add_cpu_dev_symlink(policy, j); if (ret) break; } + return ret; } +static void cpufreq_remove_dev_symlink(struct cpufreq_policy *policy) +{ + unsigned int j; + + /* Some related CPUs might not be present (physically hotplugged) */ + for_each_cpu_and(j, policy->related_cpus, cpu_present_mask) { + if (j == policy->kobj_cpu) + continue; + + remove_cpu_dev_symlink(policy, j); + } +} + static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, struct device *dev) { @@ -1075,7 +1114,7 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, } } - return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); + return 0; } static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) @@ -1095,7 +1134,7 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) return policy; } -static struct cpufreq_policy *cpufreq_policy_alloc(void) +static struct cpufreq_policy *cpufreq_policy_alloc(int cpu) { struct cpufreq_policy *policy; @@ -1116,6 +1155,11 @@ static struct cpufreq_policy *cpufreq_policy_alloc(void) init_completion(&policy->kobj_unregister); INIT_WORK(&policy->update, handle_update); + policy->cpu = cpu; + + /* Set this once on allocation */ + policy->kobj_cpu = cpu; + return policy; err_free_cpumask: @@ -1134,10 +1178,11 @@ static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) blocking_notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_REMOVE_POLICY, policy); - down_read(&policy->rwsem); + down_write(&policy->rwsem); + cpufreq_remove_dev_symlink(policy); kobj = &policy->kobj; cmp = &policy->kobj_unregister; - up_read(&policy->rwsem); + up_write(&policy->rwsem); kobject_put(kobj); /* @@ -1168,27 +1213,14 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy) kfree(policy); } -static int update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu, - struct device *cpu_dev) +static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) { - int ret; - if (WARN_ON(cpu == policy->cpu)) - return 0; - - /* Move kobject to the new policy->cpu */ - ret = kobject_move(&policy->kobj, &cpu_dev->kobj); - if (ret) { - pr_err("%s: Failed to move kobj: %d\n", __func__, ret); - return ret; - } + return; down_write(&policy->rwsem); policy->cpu = cpu; - policy->kobj_cpu = cpu; up_write(&policy->rwsem); - - return 0; } /** @@ -1206,13 +1238,19 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) int ret = -ENOMEM; struct cpufreq_policy *policy; unsigned long flags; - bool recover_policy = cpufreq_suspended; - - if (cpu_is_offline(cpu)) - return 0; + bool recover_policy = !sif; pr_debug("adding CPU %u\n", cpu); + /* + * Only possible if 'cpu' wasn't physically present earlier and we are + * here from subsys_interface add callback. A hotplug notifier will + * follow and we will handle it like logical CPU hotplug then. For now, + * just create the sysfs link. + */ + if (cpu_is_offline(cpu)) + return add_cpu_dev_symlink(per_cpu(cpufreq_cpu_data, cpu), cpu); + if (!down_read_trylock(&cpufreq_rwsem)) return 0; @@ -1232,7 +1270,7 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) policy = recover_policy ? cpufreq_policy_restore(cpu) : NULL; if (!policy) { recover_policy = false; - policy = cpufreq_policy_alloc(); + policy = cpufreq_policy_alloc(cpu); if (!policy) goto nomem_out; } @@ -1243,12 +1281,8 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) * the creation of a brand new one. So we need to perform this update * by invoking update_policy_cpu(). */ - if (recover_policy && cpu != policy->cpu) { - WARN_ON(update_policy_cpu(policy, cpu, dev)); - } else { - policy->cpu = cpu; - policy->kobj_cpu = cpu; - } + if (recover_policy && cpu != policy->cpu) + update_policy_cpu(policy, cpu); cpumask_copy(policy->cpus, cpumask_of(cpu)); @@ -1427,29 +1461,14 @@ static int __cpufreq_remove_dev_prepare(struct device *dev, CPUFREQ_NAME_LEN); up_write(&policy->rwsem); - if (cpu != policy->kobj_cpu) { - sysfs_remove_link(&dev->kobj, "cpufreq"); - } else if (cpus > 1) { - /* Nominate new CPU */ - int new_cpu = cpumask_any_but(policy->cpus, cpu); - struct device *cpu_dev = get_cpu_device(new_cpu); - - sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); - ret = update_policy_cpu(policy, new_cpu, cpu_dev); - if (ret) { - if (sysfs_create_link(&cpu_dev->kobj, &policy->kobj, - "cpufreq")) - pr_err("%s: Failed to restore kobj link to cpu:%d\n", - __func__, cpu_dev->id); - return ret; - } + if (cpu != policy->cpu) + return 0; - if (!cpufreq_suspended) - pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", - __func__, new_cpu, cpu); - } else if (cpufreq_driver->stop_cpu) { + if (cpus > 1) + /* Nominate new CPU */ + update_policy_cpu(policy, cpumask_any_but(policy->cpus, cpu)); + else if (cpufreq_driver->stop_cpu) cpufreq_driver->stop_cpu(policy); - } return 0; } @@ -1470,32 +1489,11 @@ static int __cpufreq_remove_dev_finish(struct device *dev, cpumask_clear_cpu(cpu, policy->cpus); up_write(&policy->rwsem); - /* If cpu is last user of policy, free policy */ - if (policy_is_inactive(policy)) { - if (has_target()) { - ret = __cpufreq_governor(policy, - CPUFREQ_GOV_POLICY_EXIT); - if (ret) { - pr_err("%s: Failed to exit governor\n", - __func__); - return ret; - } - } - - if (!cpufreq_suspended) - cpufreq_policy_put_kobj(policy); + /* Not the last cpu of policy, start governor again ? */ + if (!policy_is_inactive(policy)) { + if (!has_target()) + return 0; - /* - * Perform the ->exit() even during light-weight tear-down, - * since this is a core component, and is essential for the - * subsequent light-weight ->init() to succeed. - */ - if (cpufreq_driver->exit) - cpufreq_driver->exit(policy); - - if (!cpufreq_suspended) - cpufreq_policy_free(policy); - } else if (has_target()) { ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); if (!ret) ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); @@ -1504,8 +1502,34 @@ static int __cpufreq_remove_dev_finish(struct device *dev, pr_err("%s: Failed to start governor\n", __func__); return ret; } + + return 0; } + /* If cpu is last user of policy, free policy */ + if (has_target()) { + ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); + if (ret) { + pr_err("%s: Failed to exit governor\n", __func__); + return ret; + } + } + + /* Free the policy kobjects only if the driver is getting removed. */ + if (sif) + cpufreq_policy_put_kobj(policy); + + /* + * Perform the ->exit() even during light-weight tear-down, + * since this is a core component, and is essential for the + * subsequent light-weight ->init() to succeed. + */ + if (cpufreq_driver->exit) + cpufreq_driver->exit(policy); + + if (sif) + cpufreq_policy_free(policy); + return 0; } @@ -1519,8 +1543,34 @@ static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) unsigned int cpu = dev->id; int ret; - if (cpu_is_offline(cpu)) + /* + * Only possible if 'cpu' is getting physically removed now. A hotplug + * notifier should have already been called and we just need to remove + * link or free policy here. + */ + if (cpu_is_offline(cpu)) { + struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); + struct cpumask mask; + + if (!policy) + return 0; + + cpumask_copy(&mask, policy->related_cpus); + cpumask_clear_cpu(cpu, &mask); + + /* + * Free policy only if all policy->related_cpus are removed + * physically. + */ + if (cpumask_intersects(&mask, cpu_present_mask)) { + remove_cpu_dev_symlink(policy, cpu); + return 0; + } + + cpufreq_policy_put_kobj(policy); + cpufreq_policy_free(policy); return 0; + } ret = __cpufreq_remove_dev_prepare(dev, sif); |