#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
+#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include <linux/tick.h>
#include <trace/events/power.h>
static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);
#endif
-/*
- * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure
- * all cpufreq/hotplug/workqueue/etc related lock issues.
- *
- * The rules for this semaphore:
- * - Any routine that wants to read from the policy structure will
- * do a down_read on this semaphore.
- * - Any routine that will write to the policy structure and/or may take away
- * the policy altogether (eg. CPU hotplug), will hold this lock in write
- * mode before doing so.
- *
- * Additional rules:
- * - Governor routines that can be called in cpufreq hotplug path should not
- * take this sem as top level hotplug notifier handler takes this.
- * - Lock should not be held across
- * __cpufreq_governor(data, CPUFREQ_GOV_STOP);
- */
-static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem);
-
-#define lock_policy_rwsem(mode, cpu) \
-static int lock_policy_rwsem_##mode(int 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; \
-}
+/* Flag to suspend/resume CPUFreq governors */
+static bool cpufreq_suspended;
-lock_policy_rwsem(read, cpu);
-lock_policy_rwsem(write, cpu);
-
-#define unlock_policy_rwsem(mode, cpu) \
-static void unlock_policy_rwsem_##mode(int cpu) \
-{ \
- struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \
- BUG_ON(!policy); \
- up_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu)); \
+static inline bool has_target(void)
+{
+ return cpufreq_driver->target_index || cpufreq_driver->target;
}
-unlock_policy_rwsem(read, cpu);
-unlock_policy_rwsem(write, cpu);
-
/*
* rwsem to guarantee that cpufreq driver module doesn't unload during critical
* sections
bool have_governor_per_policy(void)
{
- return cpufreq_driver->have_governor_per_policy;
+ return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
}
EXPORT_SYMBOL_GPL(have_governor_per_policy);
}
EXPORT_SYMBOL_GPL(get_cpu_idle_time);
+/*
+ * This is a generic cpufreq init() routine which can be used by cpufreq
+ * drivers of SMP systems. It will do following:
+ * - validate & show freq table passed
+ * - set policies transition latency
+ * - policy->cpus with all possible CPUs
+ */
+int cpufreq_generic_init(struct cpufreq_policy *policy,
+ struct cpufreq_frequency_table *table,
+ unsigned int transition_latency)
+{
+ int ret;
+
+ ret = cpufreq_table_validate_and_show(policy, table);
+ if (ret) {
+ pr_err("%s: invalid frequency table: %d\n", __func__, ret);
+ return ret;
+ }
+
+ policy->cpuinfo.transition_latency = transition_latency;
+
+ /*
+ * The driver only supports the SMP configuartion where all processors
+ * share the clock and voltage and clock.
+ */
+ cpumask_setall(policy->cpus);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_generic_init);
+
struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
{
struct cpufreq_policy *policy = NULL;
*policy = CPUFREQ_POLICY_POWERSAVE;
err = 0;
}
- } else if (cpufreq_driver->target) {
+ } else if (has_target()) {
struct cpufreq_governor *t;
mutex_lock(&cpufreq_governor_mutex);
show_one(scaling_max_freq, max);
show_one(scaling_cur_freq, cur);
-static int __cpufreq_set_policy(struct cpufreq_policy *policy,
+static int cpufreq_set_policy(struct cpufreq_policy *policy,
struct cpufreq_policy *new_policy);
/**
if (ret != 1) \
return -EINVAL; \
\
- ret = __cpufreq_set_policy(policy, &new_policy); \
+ ret = cpufreq_set_policy(policy, &new_policy); \
policy->user_policy.object = policy->object; \
\
return ret ? ret : count; \
&new_policy.governor))
return -EINVAL;
- /*
- * Do not use cpufreq_set_policy here or the user_policy.max
- * will be wrongly overridden
- */
- ret = __cpufreq_set_policy(policy, &new_policy);
+ ret = cpufreq_set_policy(policy, &new_policy);
policy->user_policy.policy = policy->policy;
policy->user_policy.governor = policy->governor;
ssize_t i = 0;
struct cpufreq_governor *t;
- if (!cpufreq_driver->target) {
+ if (!has_target()) {
i += sprintf(buf, "performance powersave");
goto out;
}
{
struct cpufreq_policy *policy = to_policy(kobj);
struct freq_attr *fattr = to_attr(attr);
- ssize_t ret = -EINVAL;
+ ssize_t ret;
if (!down_read_trylock(&cpufreq_rwsem))
- goto exit;
+ return -EINVAL;
- if (lock_policy_rwsem_read(policy->cpu) < 0)
- goto up_read;
+ down_read(&policy->rwsem);
if (fattr->show)
ret = fattr->show(policy, buf);
else
ret = -EIO;
- unlock_policy_rwsem_read(policy->cpu);
-
-up_read:
+ up_read(&policy->rwsem);
up_read(&cpufreq_rwsem);
-exit:
+
return ret;
}
if (!down_read_trylock(&cpufreq_rwsem))
goto unlock;
- if (lock_policy_rwsem_write(policy->cpu) < 0)
- goto up_read;
+ down_write(&policy->rwsem);
if (fattr->store)
ret = fattr->store(policy, buf, count);
else
ret = -EIO;
- unlock_policy_rwsem_write(policy->cpu);
+ up_write(&policy->rwsem);
-up_read:
up_read(&cpufreq_rwsem);
unlock:
put_online_cpus();
if (ret)
goto err_out_kobj_put;
}
- if (cpufreq_driver->target) {
+ if (has_target()) {
ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
if (ret)
goto err_out_kobj_put;
int ret = 0;
memcpy(&new_policy, policy, sizeof(*policy));
- /* assure that the starting sequence is run in __cpufreq_set_policy */
+ /* assure that the starting sequence is run in cpufreq_set_policy */
policy->governor = NULL;
/* set default policy */
- ret = __cpufreq_set_policy(policy, &new_policy);
+ ret = cpufreq_set_policy(policy, &new_policy);
policy->user_policy.policy = policy->policy;
policy->user_policy.governor = policy->governor;
unsigned int cpu, struct device *dev,
bool frozen)
{
- int ret = 0, has_target = !!cpufreq_driver->target;
+ int ret = 0;
unsigned long flags;
- if (has_target) {
+ if (has_target()) {
ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
if (ret) {
pr_err("%s: Failed to stop governor\n", __func__);
}
}
- lock_policy_rwsem_write(policy->cpu);
+ down_write(&policy->rwsem);
write_lock_irqsave(&cpufreq_driver_lock, flags);
per_cpu(cpufreq_cpu_data, cpu) = policy;
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
- unlock_policy_rwsem_write(policy->cpu);
+ up_write(&policy->rwsem);
- if (has_target) {
+ if (has_target()) {
if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) ||
(ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) {
pr_err("%s: Failed to start governor\n", __func__);
goto err_free_cpumask;
INIT_LIST_HEAD(&policy->policy_list);
+ init_rwsem(&policy->rwsem);
+
return policy;
err_free_cpumask:
static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
{
- if (cpu == policy->cpu)
+ if (WARN_ON(cpu == policy->cpu))
return;
- /*
- * Take direct locks as lock_policy_rwsem_write wouldn't work here.
- * Also lock for last cpu is enough here as contention will happen only
- * after policy->cpu is changed and after it is changed, other threads
- * will try to acquire lock for new cpu. And policy is already updated
- * by then.
- */
- down_write(&per_cpu(cpu_policy_rwsem, policy->cpu));
+ down_write(&policy->rwsem);
policy->last_cpu = policy->cpu;
policy->cpu = cpu;
- up_write(&per_cpu(cpu_policy_rwsem, policy->last_cpu));
+ up_write(&policy->rwsem);
-#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);
}
goto err_set_policy_cpu;
}
+ if (cpufreq_driver->get) {
+ policy->cur = cpufreq_driver->get(policy->cpu);
+ if (!policy->cur) {
+ pr_err("%s: ->get() failed\n", __func__);
+ goto err_get_freq;
+ }
+ }
+
/* related cpus should atleast have policy->cpus */
cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
per_cpu(cpufreq_cpu_data, j) = NULL;
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+err_get_freq:
+ if (cpufreq_driver->exit)
+ cpufreq_driver->exit(policy);
err_set_policy_cpu:
cpufreq_policy_free(policy);
nomem_out:
if (ret) {
pr_err("%s: Failed to move kobj: %d", __func__, ret);
- WARN_ON(lock_policy_rwsem_write(old_cpu));
+ down_write(&policy->rwsem);
cpumask_set_cpu(old_cpu, policy->cpus);
- unlock_policy_rwsem_write(old_cpu);
+ up_write(&policy->rwsem);
ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
"cpufreq");
return -EINVAL;
}
- if (cpufreq_driver->target) {
+ if (has_target()) {
ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
if (ret) {
pr_err("%s: Failed to stop governor\n", __func__);
policy->governor->name, CPUFREQ_NAME_LEN);
#endif
- lock_policy_rwsem_read(cpu);
+ down_read(&policy->rwsem);
cpus = cpumask_weight(policy->cpus);
- unlock_policy_rwsem_read(cpu);
+ up_read(&policy->rwsem);
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);
if (new_cpu >= 0) {
update_policy_cpu(policy, new_cpu);
if (!frozen) {
- pr_debug("%s: policy Kobject moved to cpu: %d "
- "from: %d\n",__func__, new_cpu, cpu);
+ pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n",
+ __func__, new_cpu, cpu);
}
}
}
return -EINVAL;
}
- WARN_ON(lock_policy_rwsem_write(cpu));
+ down_write(&policy->rwsem);
cpus = cpumask_weight(policy->cpus);
if (cpus > 1)
cpumask_clear_cpu(cpu, policy->cpus);
- unlock_policy_rwsem_write(cpu);
+ up_write(&policy->rwsem);
/* If cpu is last user of policy, free policy */
if (cpus == 1) {
- if (cpufreq_driver->target) {
+ if (has_target()) {
ret = __cpufreq_governor(policy,
CPUFREQ_GOV_POLICY_EXIT);
if (ret) {
}
if (!frozen) {
- lock_policy_rwsem_read(cpu);
+ down_read(&policy->rwsem);
kobj = &policy->kobj;
cmp = &policy->kobj_unregister;
- unlock_policy_rwsem_read(cpu);
+ up_read(&policy->rwsem);
kobject_put(kobj);
/*
if (!frozen)
cpufreq_policy_free(policy);
} else {
- if (cpufreq_driver->target) {
+ if (has_target()) {
if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) ||
(ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) {
pr_err("%s: Failed to start governor\n",
}
/**
- * __cpufreq_remove_dev - remove a CPU device
+ * 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;
- int retval;
+ int ret;
if (cpu_is_offline(cpu))
return 0;
- retval = __cpufreq_remove_dev(dev, sif, false);
- return retval;
+ ret = __cpufreq_remove_dev_prepare(dev, sif, false);
+
+ if (!ret)
+ ret = __cpufreq_remove_dev_finish(dev, sif, false);
+
+ return ret;
}
static void handle_update(struct work_struct *work)
*/
unsigned int cpufreq_get(unsigned int cpu)
{
+ struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
unsigned int ret_freq = 0;
if (cpufreq_disabled() || !cpufreq_driver)
return -ENOENT;
+ BUG_ON(!policy);
+
if (!down_read_trylock(&cpufreq_rwsem))
return 0;
- if (unlikely(lock_policy_rwsem_read(cpu)))
- goto out_policy;
+ down_read(&policy->rwsem);
ret_freq = __cpufreq_get(cpu);
- unlock_policy_rwsem_read(cpu);
-
-out_policy:
+ up_read(&policy->rwsem);
up_read(&cpufreq_rwsem);
return ret_freq;
.remove_dev = cpufreq_remove_dev,
};
+void cpufreq_suspend(void)
+{
+ struct cpufreq_policy *policy;
+
+ if (!has_target())
+ return;
+
+ pr_debug("%s: Suspending Governors\n", __func__);
+
+ list_for_each_entry(policy, &cpufreq_policy_list, policy_list)
+ if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP))
+ pr_err("%s: Failed to stop governor for policy: %p\n",
+ __func__, policy);
+
+ cpufreq_suspended = true;
+}
+
+void cpufreq_resume(void)
+{
+ struct cpufreq_policy *policy;
+
+ if (!has_target())
+ return;
+
+ pr_debug("%s: Resuming Governors\n", __func__);
+
+ cpufreq_suspended = false;
+
+ list_for_each_entry(policy, &cpufreq_policy_list, policy_list)
+ if (__cpufreq_governor(policy, CPUFREQ_GOV_START)
+ || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))
+ pr_err("%s: Failed to start governor for policy: %p\n",
+ __func__, policy);
+}
+
/**
* cpufreq_bp_suspend - Prepare the boot CPU for system suspend.
*
pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
policy->cpu, target_freq, relation, old_target_freq);
+ /*
+ * This might look like a redundant call as we are checking it again
+ * after finding index. But it is left intentionally for cases where
+ * exactly same freq is called again and so we can save on few function
+ * calls.
+ */
if (target_freq == policy->cur)
return 0;
if (cpufreq_driver->target)
retval = cpufreq_driver->target(policy, target_freq, relation);
+ else if (cpufreq_driver->target_index) {
+ struct cpufreq_frequency_table *freq_table;
+ struct cpufreq_freqs freqs;
+ bool notify;
+ int index;
+
+ freq_table = cpufreq_frequency_get_table(policy->cpu);
+ if (unlikely(!freq_table)) {
+ pr_err("%s: Unable to find freq_table\n", __func__);
+ goto out;
+ }
+ retval = cpufreq_frequency_table_target(policy, freq_table,
+ target_freq, relation, &index);
+ if (unlikely(retval)) {
+ pr_err("%s: Unable to find matching freq\n", __func__);
+ goto out;
+ }
+
+ if (freq_table[index].frequency == policy->cur) {
+ retval = 0;
+ goto out;
+ }
+
+ notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
+
+ if (notify) {
+ freqs.old = policy->cur;
+ freqs.new = freq_table[index].frequency;
+ freqs.flags = 0;
+
+ pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
+ __func__, policy->cpu, freqs.old,
+ freqs.new);
+
+ cpufreq_notify_transition(policy, &freqs,
+ CPUFREQ_PRECHANGE);
+ }
+
+ retval = cpufreq_driver->target_index(policy, index);
+ if (retval)
+ pr_err("%s: Failed to change cpu frequency: %d\n",
+ __func__, retval);
+
+ if (notify) {
+ /*
+ * Notify with old freq in case we failed to change
+ * frequency
+ */
+ if (retval)
+ freqs.new = freqs.old;
+
+ cpufreq_notify_transition(policy, &freqs,
+ CPUFREQ_POSTCHANGE);
+ }
+ }
+
+out:
return retval;
}
EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
{
int ret = -EINVAL;
- if (unlikely(lock_policy_rwsem_write(policy->cpu)))
- goto fail;
+ down_write(&policy->rwsem);
ret = __cpufreq_driver_target(policy, target_freq, relation);
- unlock_policy_rwsem_write(policy->cpu);
+ up_write(&policy->rwsem);
-fail:
return ret;
}
EXPORT_SYMBOL_GPL(cpufreq_driver_target);
struct cpufreq_governor *gov = NULL;
#endif
+ /* Don't start any governor operations if we are entering suspend */
+ if (cpufreq_suspended)
+ return 0;
+
if (policy->governor->max_transition_latency &&
policy->cpuinfo.transition_latency >
policy->governor->max_transition_latency) {
EXPORT_SYMBOL(cpufreq_get_policy);
/*
- * data : current policy.
- * policy : policy to be set.
+ * policy : current policy.
+ * new_policy: policy to be set.
*/
-static int __cpufreq_set_policy(struct cpufreq_policy *policy,
+static int cpufreq_set_policy(struct cpufreq_policy *policy,
struct cpufreq_policy *new_policy)
{
int ret = 0, failed = 1;
/* end old governor */
if (policy->governor) {
__cpufreq_governor(policy, CPUFREQ_GOV_STOP);
- unlock_policy_rwsem_write(new_policy->cpu);
+ up_write(&policy->rwsem);
__cpufreq_governor(policy,
CPUFREQ_GOV_POLICY_EXIT);
- lock_policy_rwsem_write(new_policy->cpu);
+ down_write(&policy->rwsem);
}
/* start new governor */
if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) {
failed = 0;
} else {
- unlock_policy_rwsem_write(new_policy->cpu);
+ up_write(&policy->rwsem);
__cpufreq_governor(policy,
CPUFREQ_GOV_POLICY_EXIT);
- lock_policy_rwsem_write(new_policy->cpu);
+ down_write(&policy->rwsem);
}
}
goto no_policy;
}
- if (unlikely(lock_policy_rwsem_write(cpu))) {
- ret = -EINVAL;
- goto fail;
- }
+ down_write(&policy->rwsem);
pr_debug("updating policy for CPU %u\n", cpu);
memcpy(&new_policy, policy, sizeof(*policy));
pr_debug("Driver did not initialize current freq");
policy->cur = new_policy.cur;
} else {
- if (policy->cur != new_policy.cur && cpufreq_driver->target)
+ if (policy->cur != new_policy.cur && has_target())
cpufreq_out_of_sync(cpu, policy->cur,
new_policy.cur);
}
}
- ret = __cpufreq_set_policy(policy, &new_policy);
+ ret = cpufreq_set_policy(policy, &new_policy);
- unlock_policy_rwsem_write(cpu);
+ up_write(&policy->rwsem);
-fail:
cpufreq_cpu_put(policy);
no_policy:
return ret;
dev = get_cpu_device(cpu);
if (dev) {
- if (action & CPU_TASKS_FROZEN)
- frozen = true;
-
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
__cpufreq_add_dev(dev, NULL, frozen);
return -ENODEV;
if (!driver_data || !driver_data->verify || !driver_data->init ||
- ((!driver_data->setpolicy) && (!driver_data->target)))
+ !(driver_data->setpolicy || driver_data->target_index ||
+ driver_data->target))
return -EINVAL;
pr_debug("trying to register driver %s\n", driver_data->name);
static int __init cpufreq_core_init(void)
{
- int cpu;
-
if (cpufreq_disabled())
return -ENODEV;
- for_each_possible_cpu(cpu)
- init_rwsem(&per_cpu(cpu_policy_rwsem, cpu));
-
cpufreq_global_kobject = kobject_create();
BUG_ON(!cpufreq_global_kobject);
register_syscore_ops(&cpufreq_syscore_ops);
projects / cascardo / linux.git / blobdiff