diff options
Diffstat (limited to 'drivers/cpufreq/cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 738 |
1 files changed, 393 insertions, 345 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index f0a5e2b0eb8..5c75e3147a6 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -17,24 +17,17 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#include <asm/cputime.h> -#include <linux/kernel.h> -#include <linux/kernel_stat.h> -#include <linux/module.h> -#include <linux/init.h> -#include <linux/notifier.h> +#include <linux/cpu.h> #include <linux/cpufreq.h> #include <linux/delay.h> -#include <linux/interrupt.h> -#include <linux/spinlock.h> -#include <linux/tick.h> #include <linux/device.h> -#include <linux/slab.h> -#include <linux/cpu.h> -#include <linux/completion.h> +#include <linux/init.h> +#include <linux/kernel_stat.h> +#include <linux/module.h> #include <linux/mutex.h> +#include <linux/slab.h> #include <linux/syscore_ops.h> - +#include <linux/tick.h> #include <trace/events/power.h> /** @@ -44,8 +37,10 @@ */ static struct cpufreq_driver *cpufreq_driver; static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); +static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback); static DEFINE_RWLOCK(cpufreq_driver_lock); static DEFINE_MUTEX(cpufreq_governor_lock); +static LIST_HEAD(cpufreq_policy_list); #ifdef CONFIG_HOTPLUG_CPU /* This one keeps track of the previously set governor of a removed CPU */ @@ -69,15 +64,14 @@ static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); * - Lock should not be held across * __cpufreq_governor(data, CPUFREQ_GOV_STOP); */ -static DEFINE_PER_CPU(int, cpufreq_policy_cpu); static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); #define lock_policy_rwsem(mode, cpu) \ static int lock_policy_rwsem_##mode(int cpu) \ { \ - int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ - BUG_ON(policy_cpu == -1); \ - down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ + struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \ + BUG_ON(!policy); \ + down_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu)); \ \ return 0; \ } @@ -88,14 +82,20 @@ lock_policy_rwsem(write, cpu); #define unlock_policy_rwsem(mode, cpu) \ static void unlock_policy_rwsem_##mode(int cpu) \ { \ - int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ - BUG_ON(policy_cpu == -1); \ - up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ + struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \ + BUG_ON(!policy); \ + up_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu)); \ } unlock_policy_rwsem(read, cpu); unlock_policy_rwsem(write, cpu); +/* + * rwsem to guarantee that cpufreq driver module doesn't unload during critical + * sections + */ +static DECLARE_RWSEM(cpufreq_rwsem); + /* internal prototypes */ static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); @@ -183,78 +183,46 @@ u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) } EXPORT_SYMBOL_GPL(get_cpu_idle_time); -static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) +struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) { - struct cpufreq_policy *data; + struct cpufreq_policy *policy = NULL; unsigned long flags; - if (cpu >= nr_cpu_ids) - goto err_out; + if (cpufreq_disabled() || (cpu >= nr_cpu_ids)) + return NULL; + + if (!down_read_trylock(&cpufreq_rwsem)) + return NULL; /* get the cpufreq driver */ read_lock_irqsave(&cpufreq_driver_lock, flags); - if (!cpufreq_driver) - goto err_out_unlock; - - if (!try_module_get(cpufreq_driver->owner)) - goto err_out_unlock; - - /* get the CPU */ - data = per_cpu(cpufreq_cpu_data, cpu); - - if (!data) - goto err_out_put_module; - - if (!sysfs && !kobject_get(&data->kobj)) - goto err_out_put_module; + if (cpufreq_driver) { + /* get the CPU */ + policy = per_cpu(cpufreq_cpu_data, cpu); + if (policy) + kobject_get(&policy->kobj); + } read_unlock_irqrestore(&cpufreq_driver_lock, flags); - return data; -err_out_put_module: - module_put(cpufreq_driver->owner); -err_out_unlock: - read_unlock_irqrestore(&cpufreq_driver_lock, flags); -err_out: - return NULL; -} - -struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) -{ - if (cpufreq_disabled()) - return NULL; + if (!policy) + up_read(&cpufreq_rwsem); - return __cpufreq_cpu_get(cpu, false); + return policy; } EXPORT_SYMBOL_GPL(cpufreq_cpu_get); -static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) -{ - return __cpufreq_cpu_get(cpu, true); -} - -static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) -{ - if (!sysfs) - kobject_put(&data->kobj); - module_put(cpufreq_driver->owner); -} - -void cpufreq_cpu_put(struct cpufreq_policy *data) +void cpufreq_cpu_put(struct cpufreq_policy *policy) { if (cpufreq_disabled()) return; - __cpufreq_cpu_put(data, false); + kobject_put(&policy->kobj); + up_read(&cpufreq_rwsem); } EXPORT_SYMBOL_GPL(cpufreq_cpu_put); -static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) -{ - __cpufreq_cpu_put(data, true); -} - /********************************************************************* * EXTERNALLY AFFECTING FREQUENCY CHANGES * *********************************************************************/ @@ -459,8 +427,8 @@ show_one(scaling_min_freq, min); show_one(scaling_max_freq, max); show_one(scaling_cur_freq, cur); -static int __cpufreq_set_policy(struct cpufreq_policy *data, - struct cpufreq_policy *policy); +static int __cpufreq_set_policy(struct cpufreq_policy *policy, + struct cpufreq_policy *new_policy); /** * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access @@ -699,12 +667,12 @@ static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) struct cpufreq_policy *policy = to_policy(kobj); struct freq_attr *fattr = to_attr(attr); ssize_t ret = -EINVAL; - policy = cpufreq_cpu_get_sysfs(policy->cpu); - if (!policy) - goto no_policy; + + if (!down_read_trylock(&cpufreq_rwsem)) + goto exit; if (lock_policy_rwsem_read(policy->cpu) < 0) - goto fail; + goto up_read; if (fattr->show) ret = fattr->show(policy, buf); @@ -712,9 +680,10 @@ static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) ret = -EIO; unlock_policy_rwsem_read(policy->cpu); -fail: - cpufreq_cpu_put_sysfs(policy); -no_policy: + +up_read: + up_read(&cpufreq_rwsem); +exit: return ret; } @@ -724,12 +693,12 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr, struct cpufreq_policy *policy = to_policy(kobj); struct freq_attr *fattr = to_attr(attr); ssize_t ret = -EINVAL; - policy = cpufreq_cpu_get_sysfs(policy->cpu); - if (!policy) - goto no_policy; + + if (!down_read_trylock(&cpufreq_rwsem)) + goto exit; if (lock_policy_rwsem_write(policy->cpu) < 0) - goto fail; + goto up_read; if (fattr->store) ret = fattr->store(policy, buf, count); @@ -737,9 +706,10 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr, ret = -EIO; unlock_policy_rwsem_write(policy->cpu); -fail: - cpufreq_cpu_put_sysfs(policy); -no_policy: + +up_read: + up_read(&cpufreq_rwsem); +exit: return ret; } @@ -805,41 +775,32 @@ void cpufreq_sysfs_remove_file(const struct attribute *attr) EXPORT_SYMBOL(cpufreq_sysfs_remove_file); /* symlink affected CPUs */ -static int cpufreq_add_dev_symlink(unsigned int cpu, - struct cpufreq_policy *policy) +static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) { unsigned int j; int ret = 0; for_each_cpu(j, policy->cpus) { - struct cpufreq_policy *managed_policy; struct device *cpu_dev; - if (j == cpu) + if (j == policy->cpu) continue; - pr_debug("CPU %u already managed, adding link\n", j); - managed_policy = cpufreq_cpu_get(cpu); + 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"); - if (ret) { - cpufreq_cpu_put(managed_policy); - return ret; - } + if (ret) + break; } return ret; } -static int cpufreq_add_dev_interface(unsigned int cpu, - struct cpufreq_policy *policy, +static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, struct device *dev) { - struct cpufreq_policy new_policy; struct freq_attr **drv_attr; - unsigned long flags; int ret = 0; - unsigned int j; /* prepare interface data */ ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, @@ -871,18 +832,24 @@ static int cpufreq_add_dev_interface(unsigned int cpu, goto err_out_kobj_put; } - write_lock_irqsave(&cpufreq_driver_lock, flags); - for_each_cpu(j, policy->cpus) { - per_cpu(cpufreq_cpu_data, j) = policy; - per_cpu(cpufreq_policy_cpu, j) = policy->cpu; - } - write_unlock_irqrestore(&cpufreq_driver_lock, flags); - - ret = cpufreq_add_dev_symlink(cpu, policy); + ret = cpufreq_add_dev_symlink(policy); if (ret) goto err_out_kobj_put; - memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); + return ret; + +err_out_kobj_put: + kobject_put(&policy->kobj); + wait_for_completion(&policy->kobj_unregister); + return ret; +} + +static void cpufreq_init_policy(struct cpufreq_policy *policy) +{ + struct cpufreq_policy new_policy; + int ret = 0; + + memcpy(&new_policy, policy, sizeof(*policy)); /* assure that the starting sequence is run in __cpufreq_set_policy */ policy->governor = NULL; @@ -896,72 +863,106 @@ static int cpufreq_add_dev_interface(unsigned int cpu, if (cpufreq_driver->exit) cpufreq_driver->exit(policy); } - return ret; - -err_out_kobj_put: - kobject_put(&policy->kobj); - wait_for_completion(&policy->kobj_unregister); - return ret; } #ifdef CONFIG_HOTPLUG_CPU -static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, - struct device *dev) +static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, + unsigned int cpu, struct device *dev, + bool frozen) { - struct cpufreq_policy *policy; int ret = 0, has_target = !!cpufreq_driver->target; unsigned long flags; - policy = cpufreq_cpu_get(sibling); - WARN_ON(!policy); - - if (has_target) - __cpufreq_governor(policy, CPUFREQ_GOV_STOP); + if (has_target) { + ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); + if (ret) { + pr_err("%s: Failed to stop governor\n", __func__); + return ret; + } + } - lock_policy_rwsem_write(sibling); + lock_policy_rwsem_write(policy->cpu); write_lock_irqsave(&cpufreq_driver_lock, flags); cpumask_set_cpu(cpu, policy->cpus); - per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; per_cpu(cpufreq_cpu_data, cpu) = policy; write_unlock_irqrestore(&cpufreq_driver_lock, flags); - unlock_policy_rwsem_write(sibling); + unlock_policy_rwsem_write(policy->cpu); if (has_target) { - __cpufreq_governor(policy, CPUFREQ_GOV_START); - __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); + if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || + (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { + pr_err("%s: Failed to start governor\n", __func__); + return ret; + } } - ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); - if (ret) { - cpufreq_cpu_put(policy); - return ret; - } + /* Don't touch sysfs links during light-weight init */ + if (!frozen) + ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); - return 0; + return ret; } #endif -/** - * cpufreq_add_dev - add a CPU device - * - * Adds the cpufreq interface for a CPU device. - * - * The Oracle says: try running cpufreq registration/unregistration concurrently - * with with cpu hotplugging and all hell will break loose. Tried to clean this - * mess up, but more thorough testing is needed. - Mathieu - */ -static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) +static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) +{ + struct cpufreq_policy *policy; + unsigned long flags; + + write_lock_irqsave(&cpufreq_driver_lock, flags); + + policy = per_cpu(cpufreq_cpu_data_fallback, cpu); + + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + return policy; +} + +static struct cpufreq_policy *cpufreq_policy_alloc(void) +{ + struct cpufreq_policy *policy; + + policy = kzalloc(sizeof(*policy), GFP_KERNEL); + if (!policy) + return NULL; + + if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) + goto err_free_policy; + + if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) + goto err_free_cpumask; + + INIT_LIST_HEAD(&policy->policy_list); + return policy; + +err_free_cpumask: + free_cpumask_var(policy->cpus); +err_free_policy: + kfree(policy); + + return NULL; +} + +static void cpufreq_policy_free(struct cpufreq_policy *policy) +{ + free_cpumask_var(policy->related_cpus); + free_cpumask_var(policy->cpus); + kfree(policy); +} + +static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, + bool frozen) { unsigned int j, cpu = dev->id; int ret = -ENOMEM; struct cpufreq_policy *policy; unsigned long flags; #ifdef CONFIG_HOTPLUG_CPU + struct cpufreq_policy *tpolicy; struct cpufreq_governor *gov; - int sibling; #endif if (cpu_is_offline(cpu)) @@ -977,43 +978,38 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) cpufreq_cpu_put(policy); return 0; } +#endif + + if (!down_read_trylock(&cpufreq_rwsem)) + return 0; #ifdef CONFIG_HOTPLUG_CPU /* Check if this cpu was hot-unplugged earlier and has siblings */ read_lock_irqsave(&cpufreq_driver_lock, flags); - for_each_online_cpu(sibling) { - struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); - if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { + list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) { + if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { read_unlock_irqrestore(&cpufreq_driver_lock, flags); - return cpufreq_add_policy_cpu(cpu, sibling, dev); + ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev, frozen); + up_read(&cpufreq_rwsem); + return ret; } } read_unlock_irqrestore(&cpufreq_driver_lock, flags); #endif -#endif - if (!try_module_get(cpufreq_driver->owner)) { - ret = -EINVAL; - goto module_out; - } + if (frozen) + /* Restore the saved policy when doing light-weight init */ + policy = cpufreq_policy_restore(cpu); + else + policy = cpufreq_policy_alloc(); - policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); if (!policy) goto nomem_out; - if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) - goto err_free_policy; - - if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) - goto err_free_cpumask; - policy->cpu = cpu; policy->governor = CPUFREQ_DEFAULT_GOVERNOR; cpumask_copy(policy->cpus, cpumask_of(cpu)); - /* Initially set CPU itself as the policy_cpu */ - per_cpu(cpufreq_policy_cpu, cpu) = cpu; - init_completion(&policy->kobj_unregister); INIT_WORK(&policy->update, handle_update); @@ -1050,12 +1046,26 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) } #endif - ret = cpufreq_add_dev_interface(cpu, policy, dev); - if (ret) - goto err_out_unregister; + 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); + + if (!frozen) { + ret = cpufreq_add_dev_interface(policy, dev); + if (ret) + goto err_out_unregister; + } + + 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); kobject_uevent(&policy->kobj, KOBJ_ADD); - module_put(cpufreq_driver->owner); + up_read(&cpufreq_rwsem); + pr_debug("initialization complete\n"); return 0; @@ -1066,32 +1076,33 @@ err_out_unregister: per_cpu(cpufreq_cpu_data, j) = NULL; write_unlock_irqrestore(&cpufreq_driver_lock, flags); - kobject_put(&policy->kobj); - wait_for_completion(&policy->kobj_unregister); - err_set_policy_cpu: - per_cpu(cpufreq_policy_cpu, cpu) = -1; - free_cpumask_var(policy->related_cpus); -err_free_cpumask: - free_cpumask_var(policy->cpus); -err_free_policy: - kfree(policy); + cpufreq_policy_free(policy); nomem_out: - module_put(cpufreq_driver->owner); -module_out: + up_read(&cpufreq_rwsem); + return ret; } -static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) +/** + * cpufreq_add_dev - add a CPU device + * + * Adds the cpufreq interface for a CPU device. + * + * The Oracle says: try running cpufreq registration/unregistration concurrently + * with with cpu hotplugging and all hell will break loose. Tried to clean this + * mess up, but more thorough testing is needed. - Mathieu + */ +static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) { - int j; + return __cpufreq_add_dev(dev, sif, false); +} +static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) +{ policy->last_cpu = policy->cpu; policy->cpu = cpu; - for_each_cpu(j, policy->cpus) - per_cpu(cpufreq_policy_cpu, j) = cpu; - #ifdef CONFIG_CPU_FREQ_TABLE cpufreq_frequency_table_update_policy_cpu(policy); #endif @@ -1099,6 +1110,37 @@ static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) CPUFREQ_UPDATE_POLICY_CPU, policy); } +static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, + unsigned int old_cpu, bool frozen) +{ + struct device *cpu_dev; + int ret; + + /* first sibling now owns the new sysfs dir */ + cpu_dev = get_cpu_device(cpumask_first(policy->cpus)); + + /* Don't touch sysfs files during light-weight tear-down */ + if (frozen) + return cpu_dev->id; + + sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); + ret = kobject_move(&policy->kobj, &cpu_dev->kobj); + if (ret) { + pr_err("%s: Failed to move kobj: %d", __func__, ret); + + WARN_ON(lock_policy_rwsem_write(old_cpu)); + cpumask_set_cpu(old_cpu, policy->cpus); + unlock_policy_rwsem_write(old_cpu); + + ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, + "cpufreq"); + + return -EINVAL; + } + + return cpu_dev->id; +} + /** * __cpufreq_remove_dev - remove a CPU device * @@ -1107,111 +1149,126 @@ static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) * This routine frees the rwsem before returning. */ static int __cpufreq_remove_dev(struct device *dev, - struct subsys_interface *sif) + struct subsys_interface *sif, bool frozen) { - unsigned int cpu = dev->id, ret, cpus; + unsigned int cpu = dev->id, cpus; + int new_cpu, ret; unsigned long flags; - struct cpufreq_policy *data; + struct cpufreq_policy *policy; struct kobject *kobj; struct completion *cmp; - struct device *cpu_dev; pr_debug("%s: unregistering CPU %u\n", __func__, cpu); write_lock_irqsave(&cpufreq_driver_lock, flags); - data = per_cpu(cpufreq_cpu_data, cpu); - per_cpu(cpufreq_cpu_data, cpu) = NULL; + policy = per_cpu(cpufreq_cpu_data, cpu); + + /* Save the policy somewhere when doing a light-weight tear-down */ + if (frozen) + per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; write_unlock_irqrestore(&cpufreq_driver_lock, flags); - if (!data) { + if (!policy) { pr_debug("%s: No cpu_data found\n", __func__); return -EINVAL; } - if (cpufreq_driver->target) - __cpufreq_governor(data, CPUFREQ_GOV_STOP); + if (cpufreq_driver->target) { + ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); + if (ret) { + pr_err("%s: Failed to stop governor\n", __func__); + return ret; + } + } #ifdef CONFIG_HOTPLUG_CPU if (!cpufreq_driver->setpolicy) strncpy(per_cpu(cpufreq_cpu_governor, cpu), - data->governor->name, CPUFREQ_NAME_LEN); + policy->governor->name, CPUFREQ_NAME_LEN); #endif WARN_ON(lock_policy_rwsem_write(cpu)); - cpus = cpumask_weight(data->cpus); + cpus = cpumask_weight(policy->cpus); if (cpus > 1) - cpumask_clear_cpu(cpu, data->cpus); + cpumask_clear_cpu(cpu, policy->cpus); unlock_policy_rwsem_write(cpu); - if (cpu != data->cpu) { + if (cpu != policy->cpu && !frozen) { sysfs_remove_link(&dev->kobj, "cpufreq"); } else if (cpus > 1) { - /* first sibling now owns the new sysfs dir */ - cpu_dev = get_cpu_device(cpumask_first(data->cpus)); - sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); - ret = kobject_move(&data->kobj, &cpu_dev->kobj); - if (ret) { - pr_err("%s: Failed to move kobj: %d", __func__, ret); + new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu, frozen); + if (new_cpu >= 0) { WARN_ON(lock_policy_rwsem_write(cpu)); - cpumask_set_cpu(cpu, data->cpus); - - write_lock_irqsave(&cpufreq_driver_lock, flags); - per_cpu(cpufreq_cpu_data, cpu) = data; - write_unlock_irqrestore(&cpufreq_driver_lock, flags); - + update_policy_cpu(policy, new_cpu); unlock_policy_rwsem_write(cpu); - ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, - "cpufreq"); - return -EINVAL; + if (!frozen) { + pr_debug("%s: policy Kobject moved to cpu: %d " + "from: %d\n",__func__, new_cpu, cpu); + } } - - WARN_ON(lock_policy_rwsem_write(cpu)); - update_policy_cpu(data, cpu_dev->id); - unlock_policy_rwsem_write(cpu); - pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", - __func__, cpu_dev->id, cpu); } /* If cpu is last user of policy, free policy */ if (cpus == 1) { - if (cpufreq_driver->target) - __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); - - lock_policy_rwsem_read(cpu); - kobj = &data->kobj; - cmp = &data->kobj_unregister; - unlock_policy_rwsem_read(cpu); - kobject_put(kobj); - - /* we need to make sure that the underlying kobj is actually - * not referenced anymore by anybody before we proceed with - * unloading. - */ - pr_debug("waiting for dropping of refcount\n"); - wait_for_completion(cmp); - pr_debug("wait complete\n"); + if (cpufreq_driver->target) { + ret = __cpufreq_governor(policy, + CPUFREQ_GOV_POLICY_EXIT); + if (ret) { + pr_err("%s: Failed to exit governor\n", + __func__); + return ret; + } + } + + if (!frozen) { + lock_policy_rwsem_read(cpu); + kobj = &policy->kobj; + cmp = &policy->kobj_unregister; + unlock_policy_rwsem_read(cpu); + kobject_put(kobj); + + /* + * We need to make sure that the underlying kobj is + * actually not referenced anymore by anybody before we + * proceed with unloading. + */ + pr_debug("waiting for dropping of refcount\n"); + wait_for_completion(cmp); + pr_debug("wait complete\n"); + } + /* + * 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(data); + cpufreq_driver->exit(policy); - free_cpumask_var(data->related_cpus); - free_cpumask_var(data->cpus); - kfree(data); + /* 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 (!frozen) + cpufreq_policy_free(policy); } else { - pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); - cpufreq_cpu_put(data); if (cpufreq_driver->target) { - __cpufreq_governor(data, CPUFREQ_GOV_START); - __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); + if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || + (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { + pr_err("%s: Failed to start governor\n", + __func__); + return ret; + } } } - per_cpu(cpufreq_policy_cpu, cpu) = -1; + per_cpu(cpufreq_cpu_data, cpu) = NULL; return 0; } @@ -1223,7 +1280,7 @@ static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) if (cpu_is_offline(cpu)) return 0; - retval = __cpufreq_remove_dev(dev, sif); + retval = __cpufreq_remove_dev(dev, sif, false); return retval; } @@ -1344,10 +1401,9 @@ static unsigned int __cpufreq_get(unsigned int cpu) unsigned int cpufreq_get(unsigned int cpu) { unsigned int ret_freq = 0; - struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); - if (!policy) - goto out; + if (!down_read_trylock(&cpufreq_rwsem)) + return 0; if (unlikely(lock_policy_rwsem_read(cpu))) goto out_policy; @@ -1357,8 +1413,8 @@ unsigned int cpufreq_get(unsigned int cpu) unlock_policy_rwsem_read(cpu); out_policy: - cpufreq_cpu_put(policy); -out: + up_read(&cpufreq_rwsem); + return ret_freq; } EXPORT_SYMBOL(cpufreq_get); @@ -1381,23 +1437,23 @@ static int cpufreq_bp_suspend(void) int ret = 0; int cpu = smp_processor_id(); - struct cpufreq_policy *cpu_policy; + struct cpufreq_policy *policy; pr_debug("suspending cpu %u\n", cpu); /* If there's no policy for the boot CPU, we have nothing to do. */ - cpu_policy = cpufreq_cpu_get(cpu); - if (!cpu_policy) + policy = cpufreq_cpu_get(cpu); + if (!policy) return 0; if (cpufreq_driver->suspend) { - ret = cpufreq_driver->suspend(cpu_policy); + ret = cpufreq_driver->suspend(policy); if (ret) printk(KERN_ERR "cpufreq: suspend failed in ->suspend " - "step on CPU %u\n", cpu_policy->cpu); + "step on CPU %u\n", policy->cpu); } - cpufreq_cpu_put(cpu_policy); + cpufreq_cpu_put(policy); return ret; } @@ -1419,28 +1475,28 @@ static void cpufreq_bp_resume(void) int ret = 0; int cpu = smp_processor_id(); - struct cpufreq_policy *cpu_policy; + struct cpufreq_policy *policy; pr_debug("resuming cpu %u\n", cpu); /* If there's no policy for the boot CPU, we have nothing to do. */ - cpu_policy = cpufreq_cpu_get(cpu); - if (!cpu_policy) + policy = cpufreq_cpu_get(cpu); + if (!policy) return; if (cpufreq_driver->resume) { - ret = cpufreq_driver->resume(cpu_policy); + ret = cpufreq_driver->resume(policy); if (ret) { printk(KERN_ERR "cpufreq: resume failed in ->resume " - "step on CPU %u\n", cpu_policy->cpu); + "step on CPU %u\n", policy->cpu); goto fail; } } - schedule_work(&cpu_policy->update); + schedule_work(&policy->update); fail: - cpufreq_cpu_put(cpu_policy); + cpufreq_cpu_put(policy); } static struct syscore_ops cpufreq_syscore_ops = { @@ -1594,18 +1650,6 @@ fail: } EXPORT_SYMBOL_GPL(cpufreq_driver_target); -int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) -{ - if (cpufreq_disabled()) - return 0; - - if (!cpufreq_driver->getavg) - return 0; - - return cpufreq_driver->getavg(policy, cpu); -} -EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); - /* * when "event" is CPUFREQ_GOV_LIMITS */ @@ -1640,8 +1684,9 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, } } - if (!try_module_get(policy->governor->owner)) - return -EINVAL; + if (event == CPUFREQ_GOV_POLICY_INIT) + if (!try_module_get(policy->governor->owner)) + return -EINVAL; pr_debug("__cpufreq_governor for CPU %u, event %u\n", policy->cpu, event); @@ -1677,11 +1722,8 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, mutex_unlock(&cpufreq_governor_lock); } - /* we keep one module reference alive for - each CPU governed by this CPU */ - if ((event != CPUFREQ_GOV_START) || ret) - module_put(policy->governor->owner); - if ((event == CPUFREQ_GOV_STOP) && !ret) + if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || + ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) module_put(policy->governor->owner); return ret; @@ -1761,7 +1803,7 @@ int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) if (!cpu_policy) return -EINVAL; - memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); + memcpy(policy, cpu_policy, sizeof(*policy)); cpufreq_cpu_put(cpu_policy); return 0; @@ -1772,95 +1814,94 @@ EXPORT_SYMBOL(cpufreq_get_policy); * data : current policy. * policy : policy to be set. */ -static int __cpufreq_set_policy(struct cpufreq_policy *data, - struct cpufreq_policy *policy) +static int __cpufreq_set_policy(struct cpufreq_policy *policy, + struct cpufreq_policy *new_policy) { int ret = 0, failed = 1; - pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, - policy->min, policy->max); + pr_debug("setting new policy for CPU %u: %u - %u kHz\n", new_policy->cpu, + new_policy->min, new_policy->max); - memcpy(&policy->cpuinfo, &data->cpuinfo, - sizeof(struct cpufreq_cpuinfo)); + memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); - if (policy->min > data->max || policy->max < data->min) { + if (new_policy->min > policy->max || new_policy->max < policy->min) { ret = -EINVAL; goto error_out; } /* verify the cpu speed can be set within this limit */ - ret = cpufreq_driver->verify(policy); + ret = cpufreq_driver->verify(new_policy); if (ret) goto error_out; /* adjust if necessary - all reasons */ blocking_notifier_call_chain(&cpufreq_policy_notifier_list, - CPUFREQ_ADJUST, policy); + CPUFREQ_ADJUST, new_policy); /* adjust if necessary - hardware incompatibility*/ blocking_notifier_call_chain(&cpufreq_policy_notifier_list, - CPUFREQ_INCOMPATIBLE, policy); + CPUFREQ_INCOMPATIBLE, new_policy); /* * verify the cpu speed can be set within this limit, which might be * different to the first one */ - ret = cpufreq_driver->verify(policy); + ret = cpufreq_driver->verify(new_policy); if (ret) goto error_out; /* notification of the new policy */ blocking_notifier_call_chain(&cpufreq_policy_notifier_list, - CPUFREQ_NOTIFY, policy); + CPUFREQ_NOTIFY, new_policy); - data->min = policy->min; - data->max = policy->max; + policy->min = new_policy->min; + policy->max = new_policy->max; pr_debug("new min and max freqs are %u - %u kHz\n", - data->min, data->max); + policy->min, policy->max); if (cpufreq_driver->setpolicy) { - data->policy = policy->policy; + policy->policy = new_policy->policy; pr_debug("setting range\n"); - ret = cpufreq_driver->setpolicy(policy); + ret = cpufreq_driver->setpolicy(new_policy); } else { - if (policy->governor != data->governor) { + if (new_policy->governor != policy->governor) { /* save old, working values */ - struct cpufreq_governor *old_gov = data->governor; + struct cpufreq_governor *old_gov = policy->governor; pr_debug("governor switch\n"); /* end old governor */ - if (data->governor) { - __cpufreq_governor(data, CPUFREQ_GOV_STOP); - unlock_policy_rwsem_write(policy->cpu); - __cpufreq_governor(data, + if (policy->governor) { + __cpufreq_governor(policy, CPUFREQ_GOV_STOP); + unlock_policy_rwsem_write(new_policy->cpu); + __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); - lock_policy_rwsem_write(policy->cpu); + lock_policy_rwsem_write(new_policy->cpu); } /* start new governor */ - data->governor = policy->governor; - if (!__cpufreq_governor(data, CPUFREQ_GOV_POLICY_INIT)) { - if (!__cpufreq_governor(data, CPUFREQ_GOV_START)) { + policy->governor = new_policy->governor; + if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { + if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) { failed = 0; } else { - unlock_policy_rwsem_write(policy->cpu); - __cpufreq_governor(data, + unlock_policy_rwsem_write(new_policy->cpu); + __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); - lock_policy_rwsem_write(policy->cpu); + lock_policy_rwsem_write(new_policy->cpu); } } if (failed) { /* new governor failed, so re-start old one */ pr_debug("starting governor %s failed\n", - data->governor->name); + policy->governor->name); if (old_gov) { - data->governor = old_gov; - __cpufreq_governor(data, + policy->governor = old_gov; + __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT); - __cpufreq_governor(data, + __cpufreq_governor(policy, CPUFREQ_GOV_START); } ret = -EINVAL; @@ -1869,7 +1910,7 @@ static int __cpufreq_set_policy(struct cpufreq_policy *data, /* might be a policy change, too, so fall through */ } pr_debug("governor: change or update limits\n"); - __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); + ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); } error_out: @@ -1885,11 +1926,11 @@ error_out: */ int cpufreq_update_policy(unsigned int cpu) { - struct cpufreq_policy *data = cpufreq_cpu_get(cpu); - struct cpufreq_policy policy; + struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); + struct cpufreq_policy new_policy; int ret; - if (!data) { + if (!policy) { ret = -ENODEV; goto no_policy; } @@ -1900,34 +1941,34 @@ int cpufreq_update_policy(unsigned int cpu) } pr_debug("updating policy for CPU %u\n", cpu); - memcpy(&policy, data, sizeof(struct cpufreq_policy)); - policy.min = data->user_policy.min; - policy.max = data->user_policy.max; - policy.policy = data->user_policy.policy; - policy.governor = data->user_policy.governor; + memcpy(&new_policy, policy, sizeof(*policy)); + new_policy.min = policy->user_policy.min; + new_policy.max = policy->user_policy.max; + new_policy.policy = policy->user_policy.policy; + new_policy.governor = policy->user_policy.governor; /* * BIOS might change freq behind our back * -> ask driver for current freq and notify governors about a change */ if (cpufreq_driver->get) { - policy.cur = cpufreq_driver->get(cpu); - if (!data->cur) { + new_policy.cur = cpufreq_driver->get(cpu); + if (!policy->cur) { pr_debug("Driver did not initialize current freq"); - data->cur = policy.cur; + policy->cur = new_policy.cur; } else { - if (data->cur != policy.cur && cpufreq_driver->target) - cpufreq_out_of_sync(cpu, data->cur, - policy.cur); + if (policy->cur != new_policy.cur && cpufreq_driver->target) + cpufreq_out_of_sync(cpu, policy->cur, + new_policy.cur); } } - ret = __cpufreq_set_policy(data, &policy); + ret = __cpufreq_set_policy(policy, &new_policy); unlock_policy_rwsem_write(cpu); fail: - cpufreq_cpu_put(data); + cpufreq_cpu_put(policy); no_policy: return ret; } @@ -1938,21 +1979,26 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb, { unsigned int cpu = (unsigned long)hcpu; struct device *dev; + bool frozen = false; dev = get_cpu_device(cpu); if (dev) { - switch (action) { + + if (action & CPU_TASKS_FROZEN) + frozen = true; + + switch (action & ~CPU_TASKS_FROZEN) { case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - cpufreq_add_dev(dev, NULL); + __cpufreq_add_dev(dev, NULL, frozen); + cpufreq_update_policy(cpu); break; + case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: - __cpufreq_remove_dev(dev, NULL); + __cpufreq_remove_dev(dev, NULL, frozen); break; + case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: - cpufreq_add_dev(dev, NULL); + __cpufreq_add_dev(dev, NULL, frozen); break; } } @@ -2059,9 +2105,13 @@ int cpufreq_unregister_driver(struct cpufreq_driver *driver) subsys_interface_unregister(&cpufreq_interface); unregister_hotcpu_notifier(&cpufreq_cpu_notifier); + down_write(&cpufreq_rwsem); write_lock_irqsave(&cpufreq_driver_lock, flags); + cpufreq_driver = NULL; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + up_write(&cpufreq_rwsem); return 0; } @@ -2074,10 +2124,8 @@ static int __init cpufreq_core_init(void) if (cpufreq_disabled()) return -ENODEV; - for_each_possible_cpu(cpu) { - per_cpu(cpufreq_policy_cpu, cpu) = -1; + for_each_possible_cpu(cpu) init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); - } cpufreq_global_kobject = kobject_create(); BUG_ON(!cpufreq_global_kobject); |