X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=drivers%2Fcpufreq%2Fcpufreq.c;h=2968ed6a9c4997003591a9ebc33546e19d6deb0b;hb=23425caeebc2e06629ef04f6197543cfe3f7d7b2;hp=47d2ad0ae079c738fa8aa90656595026a56d7a8a;hpb=42a06f2166f2f6f7bf04f32b4e823eacdceafdc9;p=safe%2Fjmp%2Flinux-2.6 diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 47d2ad0..2968ed6 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -761,6 +761,10 @@ static struct kobj_type ktype_cpufreq = { * 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 sys_device *sys_dev) { @@ -772,9 +776,6 @@ static int cpufreq_add_dev(struct sys_device *sys_dev) struct sys_device *cpu_sys_dev; unsigned long flags; unsigned int j; -#ifdef CONFIG_SMP - struct cpufreq_policy *managed_policy; -#endif if (cpu_is_offline(cpu)) return 0; @@ -804,15 +805,12 @@ static int cpufreq_add_dev(struct sys_device *sys_dev) goto nomem_out; } if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) { - kfree(policy); ret = -ENOMEM; - goto nomem_out; + goto err_free_policy; } - if (!alloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) { - free_cpumask_var(policy->cpus); - kfree(policy); + if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) { ret = -ENOMEM; - goto nomem_out; + goto err_free_cpumask; } policy->cpu = cpu; @@ -820,7 +818,8 @@ static int cpufreq_add_dev(struct sys_device *sys_dev) /* Initially set CPU itself as the policy_cpu */ per_cpu(policy_cpu, cpu) = cpu; - lock_policy_rwsem_write(cpu); + ret = (lock_policy_rwsem_write(cpu) < 0); + WARN_ON(ret); init_completion(&policy->kobj_unregister); INIT_WORK(&policy->update, handle_update); @@ -833,7 +832,7 @@ static int cpufreq_add_dev(struct sys_device *sys_dev) ret = cpufreq_driver->init(policy); if (ret) { dprintk("initialization failed\n"); - goto err_out; + goto err_unlock_policy; } policy->user_policy.min = policy->min; policy->user_policy.max = policy->max; @@ -852,21 +851,31 @@ static int cpufreq_add_dev(struct sys_device *sys_dev) #endif for_each_cpu(j, policy->cpus) { + struct cpufreq_policy *managed_policy; + if (cpu == j) continue; /* Check for existing affected CPUs. * They may not be aware of it due to CPU Hotplug. + * cpufreq_cpu_put is called when the device is removed + * in __cpufreq_remove_dev() */ - managed_policy = cpufreq_cpu_get(j); /* FIXME: Where is this released? What about error paths? */ + managed_policy = cpufreq_cpu_get(j); if (unlikely(managed_policy)) { /* Set proper policy_cpu */ unlock_policy_rwsem_write(cpu); per_cpu(policy_cpu, cpu) = managed_policy->cpu; - if (lock_policy_rwsem_write(cpu) < 0) - goto err_out_driver_exit; + if (lock_policy_rwsem_write(cpu) < 0) { + /* Should not go through policy unlock path */ + if (cpufreq_driver->exit) + cpufreq_driver->exit(policy); + ret = -EBUSY; + cpufreq_cpu_put(managed_policy); + goto err_free_cpumask; + } spin_lock_irqsave(&cpufreq_driver_lock, flags); cpumask_copy(managed_policy->cpus, policy->cpus); @@ -878,11 +887,13 @@ static int cpufreq_add_dev(struct sys_device *sys_dev) &managed_policy->kobj, "cpufreq"); if (ret) - goto err_out_driver_exit; - - cpufreq_debug_enable_ratelimit(); - ret = 0; - goto err_out_driver_exit; /* call driver->exit() */ + cpufreq_cpu_put(managed_policy); + /* + * Success. We only needed to be added to the mask. + * Call driver->exit() because only the cpu parent of + * the kobj needed to call init(). + */ + goto out_driver_exit; /* call driver->exit() */ } } #endif @@ -892,29 +903,31 @@ static int cpufreq_add_dev(struct sys_device *sys_dev) ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj, "cpufreq"); if (ret) - goto err_out_driver_exit; + goto out_driver_exit; /* set up files for this cpu device */ drv_attr = cpufreq_driver->attr; while ((drv_attr) && (*drv_attr)) { ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); if (ret) - goto err_out_driver_exit; + goto err_out_kobj_put; drv_attr++; } if (cpufreq_driver->get) { ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); if (ret) - goto err_out_driver_exit; + goto err_out_kobj_put; } if (cpufreq_driver->target) { ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); if (ret) - goto err_out_driver_exit; + goto err_out_kobj_put; } spin_lock_irqsave(&cpufreq_driver_lock, flags); for_each_cpu(j, policy->cpus) { + if (!cpu_online(j)) + continue; per_cpu(cpufreq_cpu_data, j) = policy; per_cpu(policy_cpu, j) = policy->cpu; } @@ -922,18 +935,22 @@ static int cpufreq_add_dev(struct sys_device *sys_dev) /* symlink affected CPUs */ for_each_cpu(j, policy->cpus) { + struct cpufreq_policy *managed_policy; + if (j == cpu) continue; if (!cpu_online(j)) continue; dprintk("CPU %u already managed, adding link\n", j); - cpufreq_cpu_get(cpu); + managed_policy = cpufreq_cpu_get(cpu); cpu_sys_dev = get_cpu_sysdev(j); ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, "cpufreq"); - if (ret) + if (ret) { + cpufreq_cpu_put(managed_policy); goto err_out_unregister; + } } policy->governor = NULL; /* to assure that the starting sequence is @@ -965,17 +982,20 @@ err_out_unregister: per_cpu(cpufreq_cpu_data, j) = NULL; spin_unlock_irqrestore(&cpufreq_driver_lock, flags); +err_out_kobj_put: kobject_put(&policy->kobj); wait_for_completion(&policy->kobj_unregister); -err_out_driver_exit: +out_driver_exit: if (cpufreq_driver->exit) cpufreq_driver->exit(policy); -err_out: +err_unlock_policy: unlock_policy_rwsem_write(cpu); +err_free_cpumask: + free_cpumask_var(policy->cpus); +err_free_policy: kfree(policy); - nomem_out: module_put(cpufreq_driver->owner); module_out: @@ -1070,8 +1090,6 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev) spin_unlock_irqrestore(&cpufreq_driver_lock, flags); #endif - unlock_policy_rwsem_write(cpu); - if (cpufreq_driver->target) __cpufreq_governor(data, CPUFREQ_GOV_STOP); @@ -1088,6 +1106,8 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev) if (cpufreq_driver->exit) cpufreq_driver->exit(data); + unlock_policy_rwsem_write(cpu); + free_cpumask_var(data->related_cpus); free_cpumask_var(data->cpus); kfree(data); @@ -1228,9 +1248,9 @@ EXPORT_SYMBOL(cpufreq_get); static int cpufreq_suspend(struct sys_device *sysdev, pm_message_t pmsg) { - int cpu = sysdev->id; int ret = 0; - unsigned int cur_freq = 0; + + int cpu = sysdev->id; struct cpufreq_policy *cpu_policy; dprintk("suspending cpu %u\n", cpu); @@ -1253,42 +1273,9 @@ static int cpufreq_suspend(struct sys_device *sysdev, pm_message_t pmsg) if (cpufreq_driver->suspend) { ret = cpufreq_driver->suspend(cpu_policy, pmsg); - if (ret) { + if (ret) printk(KERN_ERR "cpufreq: suspend failed in ->suspend " "step on CPU %u\n", cpu_policy->cpu); - goto out; - } - } - - if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) - goto out; - - if (cpufreq_driver->get) - cur_freq = cpufreq_driver->get(cpu_policy->cpu); - - if (!cur_freq || !cpu_policy->cur) { - printk(KERN_ERR "cpufreq: suspend failed to assert current " - "frequency is what timing core thinks it is.\n"); - goto out; - } - - if (unlikely(cur_freq != cpu_policy->cur)) { - struct cpufreq_freqs freqs; - - if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) - dprintk("Warning: CPU frequency is %u, " - "cpufreq assumed %u kHz.\n", - cur_freq, cpu_policy->cur); - - freqs.cpu = cpu; - freqs.old = cpu_policy->cur; - freqs.new = cur_freq; - - srcu_notifier_call_chain(&cpufreq_transition_notifier_list, - CPUFREQ_SUSPENDCHANGE, &freqs); - adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); - - cpu_policy->cur = cur_freq; } out: @@ -1300,14 +1287,17 @@ out: * cpufreq_resume - restore proper CPU frequency handling after resume * * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) - * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync - * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are - * restored. + * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are + * restored. It will verify that the current freq is in sync with + * what we believe it to be. This is a bit later than when it + * should be, but nonethteless it's better than calling + * cpufreq_driver->get() here which might re-enable interrupts... */ static int cpufreq_resume(struct sys_device *sysdev) { - int cpu = sysdev->id; int ret = 0; + + int cpu = sysdev->id; struct cpufreq_policy *cpu_policy; dprintk("resuming cpu %u\n", cpu); @@ -1337,42 +1327,8 @@ static int cpufreq_resume(struct sys_device *sysdev) } } - if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { - unsigned int cur_freq = 0; - - if (cpufreq_driver->get) - cur_freq = cpufreq_driver->get(cpu_policy->cpu); - - if (!cur_freq || !cpu_policy->cur) { - printk(KERN_ERR "cpufreq: resume failed to assert " - "current frequency is what timing core " - "thinks it is.\n"); - goto out; - } - - if (unlikely(cur_freq != cpu_policy->cur)) { - struct cpufreq_freqs freqs; - - if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) - dprintk("Warning: CPU frequency " - "is %u, cpufreq assumed %u kHz.\n", - cur_freq, cpu_policy->cur); - - freqs.cpu = cpu; - freqs.old = cpu_policy->cur; - freqs.new = cur_freq; - - srcu_notifier_call_chain( - &cpufreq_transition_notifier_list, - CPUFREQ_RESUMECHANGE, &freqs); - adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); - - cpu_policy->cur = cur_freq; - } - } - -out: schedule_work(&cpu_policy->update); + fail: cpufreq_cpu_put(cpu_policy); return ret;