diff options
Diffstat (limited to 'drivers/cpufreq/cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 76 |
1 files changed, 49 insertions, 27 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 0611ae48e767..1d041aff4d48 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -903,7 +903,7 @@ static void cpufreq_init_policy(struct cpufreq_policy *policy) #ifdef CONFIG_HOTPLUG_CPU static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, - struct device *dev) + struct device *dev, bool frozen) { struct cpufreq_policy *policy; int ret = 0, has_target = !!cpufreq_driver->target; @@ -931,13 +931,18 @@ static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); } - ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); - if (ret) { + /* Don't touch sysfs links during light-weight init */ + if (frozen) { + /* Drop the extra refcount that we took above */ cpufreq_cpu_put(policy); - return ret; + return 0; } - return 0; + ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); + if (ret) + cpufreq_cpu_put(policy); + + return ret; } #endif @@ -972,16 +977,8 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy) kfree(policy); } -/** - * 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 int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, + bool frozen) { unsigned int j, cpu = dev->id; int ret = -ENOMEM; @@ -1013,7 +1010,8 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { read_unlock_irqrestore(&cpufreq_driver_lock, flags); - return cpufreq_add_policy_cpu(cpu, sibling, dev); + return cpufreq_add_policy_cpu(cpu, sibling, dev, + frozen); } } read_unlock_irqrestore(&cpufreq_driver_lock, flags); @@ -1079,9 +1077,11 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) } write_unlock_irqrestore(&cpufreq_driver_lock, flags); - ret = cpufreq_add_dev_interface(cpu, policy, dev); - if (ret) - goto err_out_unregister; + if (!frozen) { + ret = cpufreq_add_dev_interface(cpu, policy, dev); + if (ret) + goto err_out_unregister; + } cpufreq_init_policy(policy); @@ -1112,6 +1112,20 @@ module_out: return ret; } +/** + * 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) +{ + return __cpufreq_add_dev(dev, sif, false); +} + static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) { int j; @@ -1130,7 +1144,7 @@ static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) } static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *data, - unsigned int old_cpu) + unsigned int old_cpu, bool frozen) { struct device *cpu_dev; unsigned long flags; @@ -1138,6 +1152,11 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *data, /* first sibling now owns the new sysfs dir */ cpu_dev = get_cpu_device(cpumask_first(data->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(&data->kobj, &cpu_dev->kobj); if (ret) { @@ -1169,7 +1188,7 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *data, * 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, cpus; int new_cpu; @@ -1208,17 +1227,20 @@ static int __cpufreq_remove_dev(struct device *dev, cpumask_clear_cpu(cpu, data->cpus); unlock_policy_rwsem_write(cpu); - if (cpu != data->cpu) { + if (cpu != data->cpu && !frozen) { sysfs_remove_link(&dev->kobj, "cpufreq"); } else if (cpus > 1) { - new_cpu = cpufreq_nominate_new_policy_cpu(data, cpu); + new_cpu = cpufreq_nominate_new_policy_cpu(data, cpu, frozen); if (new_cpu >= 0) { WARN_ON(lock_policy_rwsem_write(cpu)); update_policy_cpu(data, new_cpu); unlock_policy_rwsem_write(cpu); - pr_debug("%s: policy Kobject moved to cpu: %d " - "from: %d\n",__func__, new_cpu, cpu); + + if (!frozen) { + pr_debug("%s: policy Kobject moved to cpu: %d " + "from: %d\n",__func__, new_cpu, cpu); + } } } @@ -1266,7 +1288,7 @@ 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; } @@ -1992,7 +2014,7 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb, break; case CPU_DOWN_PREPARE: case CPU_DOWN_PREPARE_FROZEN: - __cpufreq_remove_dev(dev, NULL); + __cpufreq_remove_dev(dev, NULL, false); break; case CPU_DOWN_FAILED: case CPU_DOWN_FAILED_FROZEN: |