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path: root/drivers/cpufreq/cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/cpufreq.c')
-rw-r--r--drivers/cpufreq/cpufreq.c158
1 files changed, 58 insertions, 100 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index d474421d219..1cea7a1eac1 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -552,8 +552,6 @@ static ssize_t show_cpus(const struct cpumask *mask, char *buf)
*/
static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
{
- if (cpumask_empty(policy->related_cpus))
- return show_cpus(policy->cpus, buf);
return show_cpus(policy->related_cpus, buf);
}
@@ -709,92 +707,6 @@ static struct kobj_type ktype_cpufreq = {
.release = cpufreq_sysfs_release,
};
-/*
- * Returns:
- * Negative: Failure
- * 0: Success
- * Positive: When we have a managed CPU and the sysfs got symlinked
- */
-static int cpufreq_add_dev_policy(unsigned int cpu,
- struct cpufreq_policy *policy,
- struct device *dev)
-{
- int ret = 0;
-#ifdef CONFIG_SMP
- unsigned long flags;
- unsigned int j;
-#ifdef CONFIG_HOTPLUG_CPU
- struct cpufreq_governor *gov;
-
- gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu));
- if (gov) {
- policy->governor = gov;
- pr_debug("Restoring governor %s for cpu %d\n",
- policy->governor->name, cpu);
- }
-#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);
- if (unlikely(managed_policy)) {
-
- /* Set proper policy_cpu */
- unlock_policy_rwsem_write(cpu);
- per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu;
-
- if (lock_policy_rwsem_write(cpu) < 0) {
- /* Should not go through policy unlock path */
- if (cpufreq_driver->exit)
- cpufreq_driver->exit(policy);
- cpufreq_cpu_put(managed_policy);
- return -EBUSY;
- }
-
- __cpufreq_governor(managed_policy, CPUFREQ_GOV_STOP);
-
- spin_lock_irqsave(&cpufreq_driver_lock, flags);
- cpumask_copy(managed_policy->cpus, policy->cpus);
- per_cpu(cpufreq_cpu_data, cpu) = managed_policy;
- spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
-
- __cpufreq_governor(managed_policy, CPUFREQ_GOV_START);
- __cpufreq_governor(managed_policy, CPUFREQ_GOV_LIMITS);
-
- pr_debug("CPU already managed, adding link\n");
- ret = sysfs_create_link(&dev->kobj,
- &managed_policy->kobj,
- "cpufreq");
- if (ret)
- 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().
- */
- if (cpufreq_driver->exit)
- cpufreq_driver->exit(policy);
-
- if (!ret)
- return 1;
- else
- return ret;
- }
- }
-#endif
- return ret;
-}
-
-
/* symlink affected CPUs */
static int cpufreq_add_dev_symlink(unsigned int cpu,
struct cpufreq_policy *policy)
@@ -899,6 +811,42 @@ err_out_kobj_put:
return ret;
}
+#ifdef CONFIG_HOTPLUG_CPU
+static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling,
+ struct device *dev)
+{
+ struct cpufreq_policy *policy;
+ int ret = 0;
+ unsigned long flags;
+
+ policy = cpufreq_cpu_get(sibling);
+ WARN_ON(!policy);
+
+ per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu;
+
+ lock_policy_rwsem_write(cpu);
+
+ __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
+
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ cpumask_set_cpu(cpu, policy->cpus);
+ per_cpu(cpufreq_cpu_data, cpu) = policy;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ __cpufreq_governor(policy, CPUFREQ_GOV_START);
+ __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
+
+ unlock_policy_rwsem_write(cpu);
+
+ ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq");
+ if (ret) {
+ cpufreq_cpu_put(policy);
+ return ret;
+ }
+
+ return 0;
+}
+#endif
/**
* cpufreq_add_dev - add a CPU device
@@ -911,12 +859,12 @@ err_out_kobj_put:
*/
static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
{
- unsigned int cpu = dev->id;
- int ret = 0, found = 0;
+ unsigned int j, cpu = dev->id;
+ int ret = -ENOMEM, found = 0;
struct cpufreq_policy *policy;
unsigned long flags;
- unsigned int j;
#ifdef CONFIG_HOTPLUG_CPU
+ struct cpufreq_governor *gov;
int sibling;
#endif
@@ -933,6 +881,15 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
cpufreq_cpu_put(policy);
return 0;
}
+
+#ifdef CONFIG_HOTPLUG_CPU
+ /* Check if this cpu was hot-unplugged earlier and has siblings */
+ for_each_online_cpu(sibling) {
+ struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling);
+ if (cp && cpumask_test_cpu(cpu, cp->related_cpus))
+ return cpufreq_add_policy_cpu(cpu, sibling, dev);
+ }
+#endif
#endif
if (!try_module_get(cpufreq_driver->owner)) {
@@ -940,7 +897,6 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
goto module_out;
}
- ret = -ENOMEM;
policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
if (!policy)
goto nomem_out;
@@ -985,6 +941,9 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
goto err_unlock_policy;
}
+ /* related cpus should atleast have policy->cpus */
+ cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
+
/*
* affected cpus must always be the one, which are online. We aren't
* managing offline cpus here.
@@ -997,14 +956,14 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
CPUFREQ_START, policy);
- ret = cpufreq_add_dev_policy(cpu, policy, dev);
- if (ret) {
- if (ret > 0)
- /* This is a managed cpu, symlink created,
- exit with 0 */
- ret = 0;
- goto err_unlock_policy;
+#ifdef CONFIG_HOTPLUG_CPU
+ gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu));
+ if (gov) {
+ policy->governor = gov;
+ pr_debug("Restoring governor %s for cpu %d\n",
+ policy->governor->name, cpu);
}
+#endif
ret = cpufreq_add_dev_interface(cpu, policy, dev);
if (ret)
@@ -1018,7 +977,6 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
return 0;
-
err_out_unregister:
spin_lock_irqsave(&cpufreq_driver_lock, flags);
for_each_cpu(j, policy->cpus)
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-25 10:42:31 +0000