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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.c218
1 files changed, 199 insertions, 19 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 8d19f7c0601..08ca8c9f41c 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -39,7 +39,7 @@ static struct cpufreq_driver *cpufreq_driver;
static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback);
static DEFINE_RWLOCK(cpufreq_driver_lock);
-static DEFINE_MUTEX(cpufreq_governor_lock);
+DEFINE_MUTEX(cpufreq_governor_lock);
static LIST_HEAD(cpufreq_policy_list);
#ifdef CONFIG_HOTPLUG_CPU
@@ -176,6 +176,20 @@ int cpufreq_generic_init(struct cpufreq_policy *policy,
}
EXPORT_SYMBOL_GPL(cpufreq_generic_init);
+unsigned int cpufreq_generic_get(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
+
+ if (!policy || IS_ERR(policy->clk)) {
+ pr_err("%s: No %s associated to cpu: %d\n", __func__,
+ policy ? "clk" : "policy", cpu);
+ return 0;
+ }
+
+ return clk_get_rate(policy->clk) / 1000;
+}
+EXPORT_SYMBOL_GPL(cpufreq_generic_get);
+
struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
{
struct cpufreq_policy *policy = NULL;
@@ -320,10 +334,51 @@ void cpufreq_notify_transition(struct cpufreq_policy *policy,
}
EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
+/* Do post notifications when there are chances that transition has failed */
+void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
+ struct cpufreq_freqs *freqs, int transition_failed)
+{
+ cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
+ if (!transition_failed)
+ return;
+
+ swap(freqs->old, freqs->new);
+ cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
+ cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
+}
+EXPORT_SYMBOL_GPL(cpufreq_notify_post_transition);
+
/*********************************************************************
* SYSFS INTERFACE *
*********************************************************************/
+ssize_t show_boost(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
+}
+
+static ssize_t store_boost(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret, enable;
+
+ ret = sscanf(buf, "%d", &enable);
+ if (ret != 1 || enable < 0 || enable > 1)
+ return -EINVAL;
+
+ if (cpufreq_boost_trigger_state(enable)) {
+ pr_err("%s: Cannot %s BOOST!\n", __func__,
+ enable ? "enable" : "disable");
+ return -EINVAL;
+ }
+
+ pr_debug("%s: cpufreq BOOST %s\n", __func__,
+ enable ? "enabled" : "disabled");
+
+ return count;
+}
+define_one_global_rw(boost);
static struct cpufreq_governor *__find_governor(const char *str_governor)
{
@@ -929,6 +984,9 @@ static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
struct kobject *kobj;
struct completion *cmp;
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_REMOVE_POLICY, policy);
+
down_read(&policy->rwsem);
kobj = &policy->kobj;
cmp = &policy->kobj_unregister;
@@ -1051,6 +1109,11 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
goto err_set_policy_cpu;
}
+ write_lock_irqsave(&cpufreq_driver_lock, flags);
+ for_each_cpu(j, policy->cpus)
+ per_cpu(cpufreq_cpu_data, j) = policy;
+ write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
if (cpufreq_driver->get) {
policy->cur = cpufreq_driver->get(policy->cpu);
if (!policy->cur) {
@@ -1059,6 +1122,46 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
}
}
+ /*
+ * Sometimes boot loaders set CPU frequency to a value outside of
+ * frequency table present with cpufreq core. In such cases CPU might be
+ * unstable if it has to run on that frequency for long duration of time
+ * and so its better to set it to a frequency which is specified in
+ * freq-table. This also makes cpufreq stats inconsistent as
+ * cpufreq-stats would fail to register because current frequency of CPU
+ * isn't found in freq-table.
+ *
+ * Because we don't want this change to effect boot process badly, we go
+ * for the next freq which is >= policy->cur ('cur' must be set by now,
+ * otherwise we will end up setting freq to lowest of the table as 'cur'
+ * is initialized to zero).
+ *
+ * We are passing target-freq as "policy->cur - 1" otherwise
+ * __cpufreq_driver_target() would simply fail, as policy->cur will be
+ * equal to target-freq.
+ */
+ if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
+ && has_target()) {
+ /* Are we running at unknown frequency ? */
+ ret = cpufreq_frequency_table_get_index(policy, policy->cur);
+ if (ret == -EINVAL) {
+ /* Warn user and fix it */
+ pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
+ __func__, policy->cpu, policy->cur);
+ ret = __cpufreq_driver_target(policy, policy->cur - 1,
+ CPUFREQ_RELATION_L);
+
+ /*
+ * Reaching here after boot in a few seconds may not
+ * mean that system will remain stable at "unknown"
+ * frequency for longer duration. Hence, a BUG_ON().
+ */
+ BUG_ON(ret);
+ pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
+ __func__, policy->cpu, policy->cur);
+ }
+ }
+
/* related cpus should atleast have policy->cpus */
cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
@@ -1085,15 +1188,12 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
}
#endif
- write_lock_irqsave(&cpufreq_driver_lock, flags);
- for_each_cpu(j, policy->cpus)
- per_cpu(cpufreq_cpu_data, j) = policy;
- write_unlock_irqrestore(&cpufreq_driver_lock, flags);
-
if (!frozen) {
ret = cpufreq_add_dev_interface(policy, dev);
if (ret)
goto err_out_unregister;
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_CREATE_POLICY, policy);
}
write_lock_irqsave(&cpufreq_driver_lock, flags);
@@ -1115,12 +1215,12 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
return 0;
err_out_unregister:
+err_get_freq:
write_lock_irqsave(&cpufreq_driver_lock, flags);
for_each_cpu(j, 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:
@@ -1725,17 +1825,8 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
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);
- }
+ if (notify)
+ cpufreq_notify_post_transition(policy, &freqs, retval);
}
out:
@@ -2120,6 +2211,73 @@ static struct notifier_block __refdata cpufreq_cpu_notifier = {
};
/*********************************************************************
+ * BOOST *
+ *********************************************************************/
+static int cpufreq_boost_set_sw(int state)
+{
+ struct cpufreq_frequency_table *freq_table;
+ struct cpufreq_policy *policy;
+ int ret = -EINVAL;
+
+ list_for_each_entry(policy, &cpufreq_policy_list, policy_list) {
+ freq_table = cpufreq_frequency_get_table(policy->cpu);
+ if (freq_table) {
+ ret = cpufreq_frequency_table_cpuinfo(policy,
+ freq_table);
+ if (ret) {
+ pr_err("%s: Policy frequency update failed\n",
+ __func__);
+ break;
+ }
+ policy->user_policy.max = policy->max;
+ __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
+ }
+ }
+
+ return ret;
+}
+
+int cpufreq_boost_trigger_state(int state)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ if (cpufreq_driver->boost_enabled == state)
+ return 0;
+
+ write_lock_irqsave(&cpufreq_driver_lock, flags);
+ cpufreq_driver->boost_enabled = state;
+ write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ ret = cpufreq_driver->set_boost(state);
+ if (ret) {
+ write_lock_irqsave(&cpufreq_driver_lock, flags);
+ cpufreq_driver->boost_enabled = !state;
+ write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ pr_err("%s: Cannot %s BOOST\n", __func__,
+ state ? "enable" : "disable");
+ }
+
+ return ret;
+}
+
+int cpufreq_boost_supported(void)
+{
+ if (likely(cpufreq_driver))
+ return cpufreq_driver->boost_supported;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_boost_supported);
+
+int cpufreq_boost_enabled(void)
+{
+ return cpufreq_driver->boost_enabled;
+}
+EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
+
+/*********************************************************************
* REGISTER / UNREGISTER CPUFREQ DRIVER *
*********************************************************************/
@@ -2159,9 +2317,25 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
cpufreq_driver = driver_data;
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ if (cpufreq_boost_supported()) {
+ /*
+ * Check if driver provides function to enable boost -
+ * if not, use cpufreq_boost_set_sw as default
+ */
+ if (!cpufreq_driver->set_boost)
+ cpufreq_driver->set_boost = cpufreq_boost_set_sw;
+
+ ret = cpufreq_sysfs_create_file(&boost.attr);
+ if (ret) {
+ pr_err("%s: cannot register global BOOST sysfs file\n",
+ __func__);
+ goto err_null_driver;
+ }
+ }
+
ret = subsys_interface_register(&cpufreq_interface);
if (ret)
- goto err_null_driver;
+ goto err_boost_unreg;
if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) {
int i;
@@ -2188,6 +2362,9 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
return 0;
err_if_unreg:
subsys_interface_unregister(&cpufreq_interface);
+err_boost_unreg:
+ if (cpufreq_boost_supported())
+ cpufreq_sysfs_remove_file(&boost.attr);
err_null_driver:
write_lock_irqsave(&cpufreq_driver_lock, flags);
cpufreq_driver = NULL;
@@ -2214,6 +2391,9 @@ int cpufreq_unregister_driver(struct cpufreq_driver *driver)
pr_debug("unregistering driver %s\n", driver->name);
subsys_interface_unregister(&cpufreq_interface);
+ if (cpufreq_boost_supported())
+ cpufreq_sysfs_remove_file(&boost.attr);
+
unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
down_write(&cpufreq_rwsem);