return result;
}
+unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ struct acpi_cpufreq_data *data = policy->driver_data;
+ struct acpi_processor_performance *perf;
+ struct cpufreq_frequency_table *entry;
+ unsigned int next_perf_state, next_freq, freq;
+
+ /*
+ * Find the closest frequency above target_freq.
+ *
+ * The table is sorted in the reverse order with respect to the
+ * frequency and all of the entries are valid (see the initialization).
+ */
+ entry = data->freq_table;
+ do {
+ entry++;
+ freq = entry->frequency;
+ } while (freq >= target_freq && freq != CPUFREQ_TABLE_END);
+ entry--;
+ next_freq = entry->frequency;
+ next_perf_state = entry->driver_data;
+
+ perf = to_perf_data(data);
+ if (perf->state == next_perf_state) {
+ if (unlikely(data->resume))
+ data->resume = 0;
+ else
+ return next_freq;
+ }
+
+ data->cpu_freq_write(&perf->control_register,
+ perf->states[next_perf_state].control);
+ perf->state = next_perf_state;
+ return next_freq;
+}
+
static unsigned long
acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
{
*/
data->resume = 1;
+ policy->fast_switch_possible = !acpi_pstate_strict &&
+ !(policy_is_shared(policy) && policy->shared_type != CPUFREQ_SHARED_TYPE_ANY);
+
return result;
err_freqfree:
pr_debug("acpi_cpufreq_cpu_exit\n");
if (data) {
+ policy->fast_switch_possible = false;
policy->driver_data = NULL;
acpi_processor_unregister_performance(data->acpi_perf_cpu);
free_cpumask_var(data->freqdomain_cpus);
static struct cpufreq_driver acpi_cpufreq_driver = {
.verify = cpufreq_generic_frequency_table_verify,
.target_index = acpi_cpufreq_target,
+ .fast_switch = acpi_cpufreq_fast_switch,
.bios_limit = acpi_processor_get_bios_limit,
.init = acpi_cpufreq_cpu_init,
.exit = acpi_cpufreq_cpu_exit,
static int cpufreq_governor(struct cpufreq_policy *policy, unsigned int event);
static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
static int cpufreq_start_governor(struct cpufreq_policy *policy);
+static int cpufreq_exit_governor(struct cpufreq_policy *policy);
/**
* Two notifier lists: the "policy" list is involved in the
}
EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
+/*
+ * Fast frequency switching status count. Positive means "enabled", negative
+ * means "disabled" and 0 means "not decided yet".
+ */
+static int cpufreq_fast_switch_count;
+static DEFINE_MUTEX(cpufreq_fast_switch_lock);
+
+static void cpufreq_list_transition_notifiers(void)
+{
+ struct notifier_block *nb;
+
+ pr_info("Registered transition notifiers:\n");
+
+ mutex_lock(&cpufreq_transition_notifier_list.mutex);
+
+ for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next)
+ pr_info("%pF\n", nb->notifier_call);
+
+ mutex_unlock(&cpufreq_transition_notifier_list.mutex);
+}
+
+/**
+ * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
+ * @policy: cpufreq policy to enable fast frequency switching for.
+ *
+ * Try to enable fast frequency switching for @policy.
+ *
+ * The attempt will fail if there is at least one transition notifier registered
+ * at this point, as fast frequency switching is quite fundamentally at odds
+ * with transition notifiers. Thus if successful, it will make registration of
+ * transition notifiers fail going forward.
+ */
+void cpufreq_enable_fast_switch(struct cpufreq_policy *policy)
+{
+ lockdep_assert_held(&policy->rwsem);
+
+ if (!policy->fast_switch_possible)
+ return;
+
+ mutex_lock(&cpufreq_fast_switch_lock);
+ if (cpufreq_fast_switch_count >= 0) {
+ cpufreq_fast_switch_count++;
+ policy->fast_switch_enabled = true;
+ } else {
+ pr_warn("CPU%u: Fast frequency switching not enabled\n",
+ policy->cpu);
+ cpufreq_list_transition_notifiers();
+ }
+ mutex_unlock(&cpufreq_fast_switch_lock);
+}
+EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch);
+
+static void cpufreq_disable_fast_switch(struct cpufreq_policy *policy)
+{
+ mutex_lock(&cpufreq_fast_switch_lock);
+ if (policy->fast_switch_enabled) {
+ policy->fast_switch_enabled = false;
+ if (!WARN_ON(cpufreq_fast_switch_count <= 0))
+ cpufreq_fast_switch_count--;
+ }
+ mutex_unlock(&cpufreq_fast_switch_lock);
+}
/*********************************************************************
* SYSFS INTERFACE *
/* If cpu is last user of policy, free policy */
if (has_target()) {
- ret = cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
+ ret = cpufreq_exit_governor(policy);
if (ret)
pr_err("%s: Failed to exit governor\n", __func__);
}
ret_freq = cpufreq_driver->get(policy->cpu);
- /* Updating inactive policies is invalid, so avoid doing that. */
- if (unlikely(policy_is_inactive(policy)))
+ /*
+ * Updating inactive policies is invalid, so avoid doing that. Also
+ * if fast frequency switching is used with the given policy, the check
+ * against policy->cur is pointless, so skip it in that case too.
+ */
+ if (unlikely(policy_is_inactive(policy)) || policy->fast_switch_enabled)
return ret_freq;
if (ret_freq && policy->cur &&
switch (list) {
case CPUFREQ_TRANSITION_NOTIFIER:
+ mutex_lock(&cpufreq_fast_switch_lock);
+
+ if (cpufreq_fast_switch_count > 0) {
+ mutex_unlock(&cpufreq_fast_switch_lock);
+ return -EBUSY;
+ }
ret = srcu_notifier_chain_register(
&cpufreq_transition_notifier_list, nb);
+ if (!ret)
+ cpufreq_fast_switch_count--;
+
+ mutex_unlock(&cpufreq_fast_switch_lock);
break;
case CPUFREQ_POLICY_NOTIFIER:
ret = blocking_notifier_chain_register(
switch (list) {
case CPUFREQ_TRANSITION_NOTIFIER:
+ mutex_lock(&cpufreq_fast_switch_lock);
+
ret = srcu_notifier_chain_unregister(
&cpufreq_transition_notifier_list, nb);
+ if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
+ cpufreq_fast_switch_count++;
+
+ mutex_unlock(&cpufreq_fast_switch_lock);
break;
case CPUFREQ_POLICY_NOTIFIER:
ret = blocking_notifier_chain_unregister(
* GOVERNORS *
*********************************************************************/
+/**
+ * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
+ * @policy: cpufreq policy to switch the frequency for.
+ * @target_freq: New frequency to set (may be approximate).
+ *
+ * Carry out a fast frequency switch without sleeping.
+ *
+ * The driver's ->fast_switch() callback invoked by this function must be
+ * suitable for being called from within RCU-sched read-side critical sections
+ * and it is expected to select the minimum available frequency greater than or
+ * equal to @target_freq (CPUFREQ_RELATION_L).
+ *
+ * This function must not be called if policy->fast_switch_enabled is unset.
+ *
+ * Governors calling this function must guarantee that it will never be invoked
+ * twice in parallel for the same policy and that it will never be called in
+ * parallel with either ->target() or ->target_index() for the same policy.
+ *
+ * If CPUFREQ_ENTRY_INVALID is returned by the driver's ->fast_switch()
+ * callback to indicate an error condition, the hardware configuration must be
+ * preserved.
+ */
+unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ clamp_val(target_freq, policy->min, policy->max);
+
+ return cpufreq_driver->fast_switch(policy, target_freq);
+}
+EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
+
/* Must set freqs->new to intermediate frequency */
static int __target_intermediate(struct cpufreq_policy *policy,
struct cpufreq_freqs *freqs, int index)
return ret ? ret : cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
}
+static int cpufreq_exit_governor(struct cpufreq_policy *policy)
+{
+ cpufreq_disable_fast_switch(policy);
+ return cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
+}
+
int cpufreq_register_governor(struct cpufreq_governor *governor)
{
int err;
return ret;
}
- ret = cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
+ ret = cpufreq_exit_governor(policy);
if (ret) {
pr_err("%s: Failed to Exit Governor: %s (%d)\n",
__func__, old_gov->name, ret);
pr_debug("cpufreq: governor change\n");
return 0;
}
- cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
+ cpufreq_exit_governor(policy);
}
/* new governor failed, so re-start old one */
*/
struct rw_semaphore rwsem;
+ /*
+ * Fast switch flags:
+ * - fast_switch_possible should be set by the driver if it can
+ * guarantee that frequency can be changed on any CPU sharing the
+ * policy and that the change will affect all of the policy CPUs then.
+ * - fast_switch_enabled is to be set by governors that support fast
+ * freqnency switching with the help of cpufreq_enable_fast_switch().
+ */
+ bool fast_switch_possible;
+ bool fast_switch_enabled;
+
/* Synchronization for frequency transitions */
bool transition_ongoing; /* Tracks transition status */
spinlock_t transition_lock;
int cpufreq_update_policy(unsigned int cpu);
bool have_governor_per_policy(void);
struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
+void cpufreq_enable_fast_switch(struct cpufreq_policy *policy);
#else
static inline unsigned int cpufreq_get(unsigned int cpu)
{
unsigned int relation); /* Deprecated */
int (*target_index)(struct cpufreq_policy *policy,
unsigned int index);
+ unsigned int (*fast_switch)(struct cpufreq_policy *policy,
+ unsigned int target_freq);
/*
* Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
* unset.
};
/* Pass a target to the cpufreq driver */
+unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
+ unsigned int target_freq);
int cpufreq_driver_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation);
projects / GitHub / LineageOS / G12 / android_kernel_amlogic_linux-4.9.git / commitdiff