]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blobdiff - drivers/cpufreq/cpufreq.c
Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney...
[mirror_ubuntu-bionic-kernel.git] / drivers / cpufreq / cpufreq.c
index 5c75e3147a607ca70a6d880500f9a9b6fb336316..43c24aa756f6f29935af8eb0614945a442a36a19 100644 (file)
@@ -280,13 +280,6 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
        switch (state) {
 
        case CPUFREQ_PRECHANGE:
-               if (WARN(policy->transition_ongoing ==
-                                       cpumask_weight(policy->cpus),
-                               "In middle of another frequency transition\n"))
-                       return;
-
-               policy->transition_ongoing++;
-
                /* detect if the driver reported a value as "old frequency"
                 * which is not equal to what the cpufreq core thinks is
                 * "old frequency".
@@ -306,12 +299,6 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
                break;
 
        case CPUFREQ_POSTCHANGE:
-               if (WARN(!policy->transition_ongoing,
-                               "No frequency transition in progress\n"))
-                       return;
-
-               policy->transition_ongoing--;
-
                adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
                pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new,
                        (unsigned long)freqs->cpu);
@@ -437,7 +424,7 @@ static int __cpufreq_set_policy(struct cpufreq_policy *policy,
 static ssize_t store_##file_name                                       \
 (struct cpufreq_policy *policy, const char *buf, size_t count)         \
 {                                                                      \
-       unsigned int ret;                                               \
+       int ret;                                                        \
        struct cpufreq_policy new_policy;                               \
                                                                        \
        ret = cpufreq_get_policy(&new_policy, policy->cpu);             \
@@ -490,7 +477,7 @@ static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
 static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
                                        const char *buf, size_t count)
 {
-       unsigned int ret;
+       int ret;
        char    str_governor[16];
        struct cpufreq_policy new_policy;
 
@@ -694,8 +681,13 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr,
        struct freq_attr *fattr = to_attr(attr);
        ssize_t ret = -EINVAL;
 
+       get_online_cpus();
+
+       if (!cpu_online(policy->cpu))
+               goto unlock;
+
        if (!down_read_trylock(&cpufreq_rwsem))
-               goto exit;
+               goto unlock;
 
        if (lock_policy_rwsem_write(policy->cpu) < 0)
                goto up_read;
@@ -709,7 +701,9 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr,
 
 up_read:
        up_read(&cpufreq_rwsem);
-exit:
+unlock:
+       put_online_cpus();
+
        return ret;
 }
 
@@ -912,11 +906,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
        struct cpufreq_policy *policy;
        unsigned long flags;
 
-       write_lock_irqsave(&cpufreq_driver_lock, flags);
+       read_lock_irqsave(&cpufreq_driver_lock, flags);
 
        policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
 
-       write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+       read_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
        return policy;
 }
@@ -953,6 +947,21 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
        kfree(policy);
 }
 
+static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
+{
+       if (cpu == policy->cpu)
+               return;
+
+       policy->last_cpu = policy->cpu;
+       policy->cpu = cpu;
+
+#ifdef CONFIG_CPU_FREQ_TABLE
+       cpufreq_frequency_table_update_policy_cpu(policy);
+#endif
+       blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+                       CPUFREQ_UPDATE_POLICY_CPU, policy);
+}
+
 static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
                             bool frozen)
 {
@@ -1006,7 +1015,18 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
        if (!policy)
                goto nomem_out;
 
-       policy->cpu = cpu;
+
+       /*
+        * In the resume path, since we restore a saved policy, the assignment
+        * to policy->cpu is like an update of the existing policy, rather than
+        * the creation of a brand new one. So we need to perform this update
+        * by invoking update_policy_cpu().
+        */
+       if (frozen && cpu != policy->cpu)
+               update_policy_cpu(policy, cpu);
+       else
+               policy->cpu = cpu;
+
        policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
        cpumask_copy(policy->cpus, cpumask_of(cpu));
 
@@ -1098,18 +1118,6 @@ 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)
-{
-       policy->last_cpu = policy->cpu;
-       policy->cpu = cpu;
-
-#ifdef CONFIG_CPU_FREQ_TABLE
-       cpufreq_frequency_table_update_policy_cpu(policy);
-#endif
-       blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
-                       CPUFREQ_UPDATE_POLICY_CPU, policy);
-}
-
 static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy,
                                           unsigned int old_cpu, bool frozen)
 {
@@ -1141,22 +1149,14 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy,
        return cpu_dev->id;
 }
 
-/**
- * __cpufreq_remove_dev - remove a CPU device
- *
- * Removes the cpufreq interface for a CPU device.
- * Caller should already have policy_rwsem in write mode for this CPU.
- * This routine frees the rwsem before returning.
- */
-static int __cpufreq_remove_dev(struct device *dev,
-                               struct subsys_interface *sif, bool frozen)
+static int __cpufreq_remove_dev_prepare(struct device *dev,
+                                       struct subsys_interface *sif,
+                                       bool frozen)
 {
        unsigned int cpu = dev->id, cpus;
        int new_cpu, ret;
        unsigned long flags;
        struct cpufreq_policy *policy;
-       struct kobject *kobj;
-       struct completion *cmp;
 
        pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
 
@@ -1196,8 +1196,9 @@ static int __cpufreq_remove_dev(struct device *dev,
                cpumask_clear_cpu(cpu, policy->cpus);
        unlock_policy_rwsem_write(cpu);
 
-       if (cpu != policy->cpu && !frozen) {
-               sysfs_remove_link(&dev->kobj, "cpufreq");
+       if (cpu != policy->cpu) {
+               if (!frozen)
+                       sysfs_remove_link(&dev->kobj, "cpufreq");
        } else if (cpus > 1) {
 
                new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu, frozen);
@@ -1213,6 +1214,33 @@ static int __cpufreq_remove_dev(struct device *dev,
                }
        }
 
+       return 0;
+}
+
+static int __cpufreq_remove_dev_finish(struct device *dev,
+                                      struct subsys_interface *sif,
+                                      bool frozen)
+{
+       unsigned int cpu = dev->id, cpus;
+       int ret;
+       unsigned long flags;
+       struct cpufreq_policy *policy;
+       struct kobject *kobj;
+       struct completion *cmp;
+
+       read_lock_irqsave(&cpufreq_driver_lock, flags);
+       policy = per_cpu(cpufreq_cpu_data, cpu);
+       read_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+       if (!policy) {
+               pr_debug("%s: No cpu_data found\n", __func__);
+               return -EINVAL;
+       }
+
+       lock_policy_rwsem_read(cpu);
+       cpus = cpumask_weight(policy->cpus);
+       unlock_policy_rwsem_read(cpu);
+
        /* If cpu is last user of policy, free policy */
        if (cpus == 1) {
                if (cpufreq_driver->target) {
@@ -1272,6 +1300,27 @@ static int __cpufreq_remove_dev(struct device *dev,
        return 0;
 }
 
+/**
+ * __cpufreq_remove_dev - remove a CPU device
+ *
+ * Removes the cpufreq interface for a CPU device.
+ * Caller should already have policy_rwsem in write mode for this CPU.
+ * This routine frees the rwsem before returning.
+ */
+static inline int __cpufreq_remove_dev(struct device *dev,
+                                      struct subsys_interface *sif,
+                                      bool frozen)
+{
+       int ret;
+
+       ret = __cpufreq_remove_dev_prepare(dev, sif, frozen);
+
+       if (!ret)
+               ret = __cpufreq_remove_dev_finish(dev, sif, frozen);
+
+       return ret;
+}
+
 static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
 {
        unsigned int cpu = dev->id;
@@ -1610,8 +1659,6 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 
        if (cpufreq_disabled())
                return -ENODEV;
-       if (policy->transition_ongoing)
-               return -EBUSY;
 
        /* Make sure that target_freq is within supported range */
        if (target_freq > policy->max)
@@ -1692,8 +1739,9 @@ static int __cpufreq_governor(struct cpufreq_policy *policy,
                                                policy->cpu, event);
 
        mutex_lock(&cpufreq_governor_lock);
-       if ((!policy->governor_enabled && (event == CPUFREQ_GOV_STOP)) ||
-           (policy->governor_enabled && (event == CPUFREQ_GOV_START))) {
+       if ((policy->governor_enabled && event == CPUFREQ_GOV_START)
+           || (!policy->governor_enabled
+           && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) {
                mutex_unlock(&cpufreq_governor_lock);
                return -EBUSY;
        }
@@ -1994,7 +2042,11 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb,
                        break;
 
                case CPU_DOWN_PREPARE:
-                       __cpufreq_remove_dev(dev, NULL, frozen);
+                       __cpufreq_remove_dev_prepare(dev, NULL, frozen);
+                       break;
+
+               case CPU_POST_DEAD:
+                       __cpufreq_remove_dev_finish(dev, NULL, frozen);
                        break;
 
                case CPU_DOWN_FAILED: