#include <linux/completion.h>
#include <linux/mutex.h>
-#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "cpufreq-core", msg)
+#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, \
+ "cpufreq-core", msg)
/**
* The "cpufreq driver" - the arch- or hardware-dependent low
*/
static struct cpufreq_driver *cpufreq_driver;
static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS];
+#ifdef CONFIG_HOTPLUG_CPU
+/* This one keeps track of the previously set governor of a removed CPU */
+static struct cpufreq_governor *cpufreq_cpu_governor[NR_CPUS];
+#endif
static DEFINE_SPINLOCK(cpufreq_driver_lock);
+/*
+ * 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:
+ * - All holders of the lock should check to make sure that the CPU they
+ * are concerned with are online after they get the lock.
+ * - Governor routines that can be called in cpufreq hotplug path should not
+ * take this sem as top level hotplug notifier handler takes this.
+ */
+static DEFINE_PER_CPU(int, policy_cpu);
+static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem);
+
+#define lock_policy_rwsem(mode, cpu) \
+int lock_policy_rwsem_##mode \
+(int cpu) \
+{ \
+ int policy_cpu = per_cpu(policy_cpu, cpu); \
+ BUG_ON(policy_cpu == -1); \
+ down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \
+ if (unlikely(!cpu_online(cpu))) { \
+ up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \
+ return -1; \
+ } \
+ \
+ return 0; \
+}
+
+lock_policy_rwsem(read, cpu);
+EXPORT_SYMBOL_GPL(lock_policy_rwsem_read);
+
+lock_policy_rwsem(write, cpu);
+EXPORT_SYMBOL_GPL(lock_policy_rwsem_write);
+
+void unlock_policy_rwsem_read(int cpu)
+{
+ int policy_cpu = per_cpu(policy_cpu, cpu);
+ BUG_ON(policy_cpu == -1);
+ up_read(&per_cpu(cpu_policy_rwsem, policy_cpu));
+}
+EXPORT_SYMBOL_GPL(unlock_policy_rwsem_read);
+
+void unlock_policy_rwsem_write(int cpu)
+{
+ int policy_cpu = per_cpu(policy_cpu, cpu);
+ BUG_ON(policy_cpu == -1);
+ up_write(&per_cpu(cpu_policy_rwsem, policy_cpu));
+}
+EXPORT_SYMBOL_GPL(unlock_policy_rwsem_write);
+
+
/* internal prototypes */
static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event);
-static void handle_update(void *data);
+static unsigned int __cpufreq_get(unsigned int cpu);
+static void handle_update(struct work_struct *work);
/**
* Two notifier lists: the "policy" list is involved in the
* The mutex locks both lists.
*/
static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
-static BLOCKING_NOTIFIER_HEAD(cpufreq_transition_notifier_list);
+static struct srcu_notifier_head cpufreq_transition_notifier_list;
+static int __init init_cpufreq_transition_notifier_list(void)
+{
+ srcu_init_notifier_head(&cpufreq_transition_notifier_list);
+ return 0;
+}
+pure_initcall(init_cpufreq_transition_notifier_list);
static LIST_HEAD(cpufreq_governor_list);
static DEFINE_MUTEX (cpufreq_governor_mutex);
spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
}
-void cpufreq_debug_printk(unsigned int type, const char *prefix, const char *fmt, ...)
+void cpufreq_debug_printk(unsigned int type, const char *prefix,
+ const char *fmt, ...)
{
char s[256];
va_list args;
WARN_ON(!prefix);
if (type & debug) {
spin_lock_irqsave(&disable_ratelimit_lock, flags);
- if (!disable_ratelimit && debug_ratelimit && !printk_ratelimit()) {
+ if (!disable_ratelimit && debug_ratelimit
+ && !printk_ratelimit()) {
spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
return;
}
module_param(debug, uint, 0644);
-MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core, 2 to debug drivers, and 4 to debug governors.");
+MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core,"
+ " 2 to debug drivers, and 4 to debug governors.");
module_param(debug_ratelimit, uint, 0644);
-MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging: set to 0 to disable ratelimiting.");
+MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging:"
+ " set to 0 to disable ratelimiting.");
#else /* !CONFIG_CPU_FREQ_DEBUG */
if (!l_p_j_ref_freq) {
l_p_j_ref = loops_per_jiffy;
l_p_j_ref_freq = ci->old;
- dprintk("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq);
+ dprintk("saving %lu as reference value for loops_per_jiffy;"
+ "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq);
}
if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) ||
(val == CPUFREQ_POSTCHANGE && ci->old > ci->new) ||
(val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) {
- loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, ci->new);
- dprintk("scaling loops_per_jiffy to %lu for frequency %u kHz\n", loops_per_jiffy, ci->new);
+ loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
+ ci->new);
+ dprintk("scaling loops_per_jiffy to %lu"
+ "for frequency %u kHz\n", loops_per_jiffy, ci->new);
}
}
#else
-static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) { return; }
+static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
+{
+ return;
+}
#endif
freqs->old = policy->cur;
}
}
- blocking_notifier_call_chain(&cpufreq_transition_notifier_list,
+ srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
CPUFREQ_PRECHANGE, freqs);
adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
break;
case CPUFREQ_POSTCHANGE:
adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
- blocking_notifier_call_chain(&cpufreq_transition_notifier_list,
+ srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
CPUFREQ_POSTCHANGE, freqs);
if (likely(policy) && likely(policy->cpu == freqs->cpu))
policy->cur = freqs->new;
if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
*policy = CPUFREQ_POLICY_PERFORMANCE;
err = 0;
- } else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
+ } else if (!strnicmp(str_governor, "powersave",
+ CPUFREQ_NAME_LEN)) {
*policy = CPUFREQ_POLICY_POWERSAVE;
err = 0;
}
t = __find_governor(str_governor);
if (t == NULL) {
- char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", str_governor);
+ char *name = kasprintf(GFP_KERNEL, "cpufreq_%s",
+ str_governor);
if (name) {
int ret;
/**
- * cpufreq_per_cpu_attr_read() / show_##file_name() - print out cpufreq information
+ * cpufreq_per_cpu_attr_read() / show_##file_name() -
+ * print out cpufreq information
*
* Write out information from cpufreq_driver->policy[cpu]; object must be
* "unsigned int".
show_one(scaling_max_freq, max);
show_one(scaling_cur_freq, cur);
-static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy);
+static int __cpufreq_set_policy(struct cpufreq_policy *data,
+ struct cpufreq_policy *policy);
/**
* cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
if (ret != 1) \
return -EINVAL; \
\
- lock_cpu_hotplug(); \
- mutex_lock(&policy->lock); \
ret = __cpufreq_set_policy(policy, &new_policy); \
policy->user_policy.object = policy->object; \
- mutex_unlock(&policy->lock); \
- unlock_cpu_hotplug(); \
\
return ret ? ret : count; \
}
/**
* show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
*/
-static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, char *buf)
+static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy,
+ char *buf)
{
- unsigned int cur_freq = cpufreq_get(policy->cpu);
+ unsigned int cur_freq = __cpufreq_get(policy->cpu);
if (!cur_freq)
return sprintf(buf, "<unknown>");
return sprintf(buf, "%u\n", cur_freq);
/**
* show_scaling_governor - show the current policy for the specified CPU
*/
-static ssize_t show_scaling_governor (struct cpufreq_policy * policy, char *buf)
+static ssize_t show_scaling_governor (struct cpufreq_policy * policy,
+ char *buf)
{
if(policy->policy == CPUFREQ_POLICY_POWERSAVE)
return sprintf(buf, "powersave\n");
if (ret != 1)
return -EINVAL;
- if (cpufreq_parse_governor(str_governor, &new_policy.policy, &new_policy.governor))
+ if (cpufreq_parse_governor(str_governor, &new_policy.policy,
+ &new_policy.governor))
return -EINVAL;
- lock_cpu_hotplug();
-
/* Do not use cpufreq_set_policy here or the user_policy.max
will be wrongly overridden */
- mutex_lock(&policy->lock);
ret = __cpufreq_set_policy(policy, &new_policy);
policy->user_policy.policy = policy->policy;
policy->user_policy.governor = policy->governor;
- mutex_unlock(&policy->lock);
- unlock_cpu_hotplug();
-
- return ret ? ret : count;
+ if (ret)
+ return ret;
+ else
+ return count;
}
/**
/**
* show_scaling_available_governors - show the available CPUfreq governors
*/
-static ssize_t show_scaling_available_governors (struct cpufreq_policy * policy,
+static ssize_t show_scaling_available_governors (struct cpufreq_policy *policy,
char *buf)
{
ssize_t i = 0;
policy = cpufreq_cpu_get(policy->cpu);
if (!policy)
return -EINVAL;
- ret = fattr->show ? fattr->show(policy,buf) : -EIO;
+
+ if (lock_policy_rwsem_read(policy->cpu) < 0)
+ return -EINVAL;
+
+ if (fattr->show)
+ ret = fattr->show(policy, buf);
+ else
+ ret = -EIO;
+
+ unlock_policy_rwsem_read(policy->cpu);
+
cpufreq_cpu_put(policy);
return ret;
}
policy = cpufreq_cpu_get(policy->cpu);
if (!policy)
return -EINVAL;
- ret = fattr->store ? fattr->store(policy,buf,count) : -EIO;
+
+ if (lock_policy_rwsem_write(policy->cpu) < 0)
+ return -EINVAL;
+
+ if (fattr->store)
+ ret = fattr->store(policy, buf, count);
+ else
+ ret = -EIO;
+
+ unlock_policy_rwsem_write(policy->cpu);
+
cpufreq_cpu_put(policy);
return ret;
}
policy->cpu = cpu;
policy->cpus = cpumask_of_cpu(cpu);
- mutex_init(&policy->lock);
- mutex_lock(&policy->lock);
+ /* Initially set CPU itself as the policy_cpu */
+ per_cpu(policy_cpu, cpu) = cpu;
+ lock_policy_rwsem_write(cpu);
+
init_completion(&policy->kobj_unregister);
- INIT_WORK(&policy->update, handle_update, (void *)(long)cpu);
+ INIT_WORK(&policy->update, handle_update);
/* call driver. From then on the cpufreq must be able
* to accept all calls to ->verify and ->setpolicy for this CPU
ret = cpufreq_driver->init(policy);
if (ret) {
dprintk("initialization failed\n");
- mutex_unlock(&policy->lock);
+ unlock_policy_rwsem_write(cpu);
goto err_out;
}
+ policy->user_policy.min = policy->cpuinfo.min_freq;
+ policy->user_policy.max = policy->cpuinfo.max_freq;
#ifdef CONFIG_SMP
+
+#ifdef CONFIG_HOTPLUG_CPU
+ if (cpufreq_cpu_governor[cpu]){
+ policy->governor = cpufreq_cpu_governor[cpu];
+ dprintk("Restoring governor %s for cpu %d\n",
+ policy->governor->name, cpu);
+ }
+#endif
+
for_each_cpu_mask(j, policy->cpus) {
if (cpu == j)
continue;
*/
managed_policy = cpufreq_cpu_get(j);
if (unlikely(managed_policy)) {
+
+ /* Set proper policy_cpu */
+ unlock_policy_rwsem_write(cpu);
+ per_cpu(policy_cpu, cpu) = managed_policy->cpu;
+
+ if (lock_policy_rwsem_write(cpu) < 0)
+ goto err_out_driver_exit;
+
spin_lock_irqsave(&cpufreq_driver_lock, flags);
managed_policy->cpus = policy->cpus;
cpufreq_cpu_data[cpu] = managed_policy;
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
dprintk("CPU already managed, adding link\n");
- sysfs_create_link(&sys_dev->kobj,
- &managed_policy->kobj, "cpufreq");
+ ret = sysfs_create_link(&sys_dev->kobj,
+ &managed_policy->kobj,
+ "cpufreq");
+ if (ret) {
+ unlock_policy_rwsem_write(cpu);
+ goto err_out_driver_exit;
+ }
cpufreq_debug_enable_ratelimit();
- mutex_unlock(&policy->lock);
ret = 0;
+ unlock_policy_rwsem_write(cpu);
goto err_out_driver_exit; /* call driver->exit() */
}
}
/* prepare interface data */
policy->kobj.parent = &sys_dev->kobj;
policy->kobj.ktype = &ktype_cpufreq;
- strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN);
+ kobject_set_name(&policy->kobj, "cpufreq");
ret = kobject_register(&policy->kobj);
if (ret) {
- mutex_unlock(&policy->lock);
+ unlock_policy_rwsem_write(cpu);
goto err_out_driver_exit;
}
/* set up files for this cpu device */
drv_attr = cpufreq_driver->attr;
while ((drv_attr) && (*drv_attr)) {
- sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
+ ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
+ if (ret)
+ goto err_out_driver_exit;
drv_attr++;
}
- if (cpufreq_driver->get)
- sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
- if (cpufreq_driver->target)
- sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
+ if (cpufreq_driver->get){
+ ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
+ if (ret)
+ goto err_out_driver_exit;
+ }
+ if (cpufreq_driver->target){
+ ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
+ if (ret)
+ goto err_out_driver_exit;
+ }
spin_lock_irqsave(&cpufreq_driver_lock, flags);
- for_each_cpu_mask(j, policy->cpus)
+ for_each_cpu_mask(j, policy->cpus) {
cpufreq_cpu_data[j] = policy;
+ per_cpu(policy_cpu, j) = policy->cpu;
+ }
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
/* symlink affected CPUs */
dprintk("CPU %u already managed, adding link\n", j);
cpufreq_cpu_get(cpu);
cpu_sys_dev = get_cpu_sysdev(j);
- sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj,
- "cpufreq");
+ ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj,
+ "cpufreq");
+ if (ret) {
+ unlock_policy_rwsem_write(cpu);
+ goto err_out_unregister;
+ }
}
policy->governor = NULL; /* to assure that the starting sequence is
* run in cpufreq_set_policy */
- mutex_unlock(&policy->lock);
/* set default policy */
- ret = cpufreq_set_policy(&new_policy);
+ ret = __cpufreq_set_policy(policy, &new_policy);
+ policy->user_policy.policy = policy->policy;
+ policy->user_policy.governor = policy->governor;
+
+ unlock_policy_rwsem_write(cpu);
+
if (ret) {
dprintk("setting policy failed\n");
goto err_out_unregister;
/**
- * 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 int cpufreq_remove_dev (struct sys_device * sys_dev)
+static int __cpufreq_remove_dev (struct sys_device * sys_dev)
{
unsigned int cpu = sys_dev->id;
unsigned long flags;
if (!data) {
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
cpufreq_debug_enable_ratelimit();
+ unlock_policy_rwsem_write(cpu);
return -EINVAL;
}
cpufreq_cpu_data[cpu] = NULL;
sysfs_remove_link(&sys_dev->kobj, "cpufreq");
cpufreq_cpu_put(data);
cpufreq_debug_enable_ratelimit();
+ unlock_policy_rwsem_write(cpu);
return 0;
}
#endif
if (!kobject_get(&data->kobj)) {
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
cpufreq_debug_enable_ratelimit();
+ unlock_policy_rwsem_write(cpu);
return -EFAULT;
}
#ifdef CONFIG_SMP
+
+#ifdef CONFIG_HOTPLUG_CPU
+ cpufreq_cpu_governor[cpu] = data->governor;
+#endif
+
/* if we have other CPUs still registered, we need to unlink them,
* or else wait_for_completion below will lock up. Clean the
* cpufreq_cpu_data[] while holding the lock, and remove the sysfs
if (j == cpu)
continue;
dprintk("removing link for cpu %u\n", j);
+#ifdef CONFIG_HOTPLUG_CPU
+ cpufreq_cpu_governor[j] = data->governor;
+#endif
cpu_sys_dev = get_cpu_sysdev(j);
sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq");
cpufreq_cpu_put(data);
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
#endif
- mutex_lock(&data->lock);
if (cpufreq_driver->target)
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
- mutex_unlock(&data->lock);
+
+ unlock_policy_rwsem_write(cpu);
kobject_unregister(&data->kobj);
}
-static void handle_update(void *data)
+static int cpufreq_remove_dev (struct sys_device * sys_dev)
{
- unsigned int cpu = (unsigned int)(long)data;
+ unsigned int cpu = sys_dev->id;
+ int retval;
+
+ if (cpu_is_offline(cpu))
+ return 0;
+
+ if (unlikely(lock_policy_rwsem_write(cpu)))
+ BUG();
+
+ retval = __cpufreq_remove_dev(sys_dev);
+ return retval;
+}
+
+
+static void handle_update(struct work_struct *work)
+{
+ struct cpufreq_policy *policy =
+ container_of(work, struct cpufreq_policy, update);
+ unsigned int cpu = policy->cpu;
dprintk("handle_update for cpu %u called\n", cpu);
cpufreq_update_policy(cpu);
}
* We adjust to current frequency first, and need to clean up later. So either call
* to cpufreq_update_policy() or schedule handle_update()).
*/
-static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigned int new_freq)
+static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq,
+ unsigned int new_freq)
{
struct cpufreq_freqs freqs;
/**
- * cpufreq_quick_get - get the CPU frequency (in kHz) frpm policy->cur
+ * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
* @cpu: CPU number
*
* This is the last known freq, without actually getting it from the driver.
unsigned int cpufreq_quick_get(unsigned int cpu)
{
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
- unsigned int ret = 0;
+ unsigned int ret_freq = 0;
if (policy) {
- mutex_lock(&policy->lock);
- ret = policy->cur;
- mutex_unlock(&policy->lock);
+ if (unlikely(lock_policy_rwsem_read(cpu)))
+ return ret_freq;
+
+ ret_freq = policy->cur;
+
+ unlock_policy_rwsem_read(cpu);
cpufreq_cpu_put(policy);
}
- return (ret);
+ return (ret_freq);
}
EXPORT_SYMBOL(cpufreq_quick_get);
+static unsigned int __cpufreq_get(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = cpufreq_cpu_data[cpu];
+ unsigned int ret_freq = 0;
+
+ if (!cpufreq_driver->get)
+ return (ret_freq);
+
+ ret_freq = cpufreq_driver->get(cpu);
+
+ if (ret_freq && policy->cur &&
+ !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
+ /* verify no discrepancy between actual and
+ saved value exists */
+ if (unlikely(ret_freq != policy->cur)) {
+ cpufreq_out_of_sync(cpu, policy->cur, ret_freq);
+ schedule_work(&policy->update);
+ }
+ }
+
+ return (ret_freq);
+}
+
/**
* cpufreq_get - get the current CPU frequency (in kHz)
* @cpu: CPU number
*/
unsigned int cpufreq_get(unsigned int cpu)
{
+ unsigned int ret_freq = 0;
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
- unsigned int ret = 0;
if (!policy)
- return 0;
-
- if (!cpufreq_driver->get)
goto out;
- mutex_lock(&policy->lock);
+ if (unlikely(lock_policy_rwsem_read(cpu)))
+ goto out_policy;
- ret = cpufreq_driver->get(cpu);
+ ret_freq = __cpufreq_get(cpu);
- if (ret && policy->cur && !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
- /* verify no discrepancy between actual and saved value exists */
- if (unlikely(ret != policy->cur)) {
- cpufreq_out_of_sync(cpu, policy->cur, ret);
- schedule_work(&policy->update);
- }
- }
+ unlock_policy_rwsem_read(cpu);
- mutex_unlock(&policy->lock);
-
-out:
+out_policy:
cpufreq_cpu_put(policy);
-
- return (ret);
+out:
+ return (ret_freq);
}
EXPORT_SYMBOL(cpufreq_get);
static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
{
int cpu = sysdev->id;
- unsigned int ret = 0;
+ int ret = 0;
unsigned int cur_freq = 0;
struct cpufreq_policy *cpu_policy;
- dprintk("resuming cpu %u\n", cpu);
+ dprintk("suspending cpu %u\n", cpu);
if (!cpu_online(cpu))
return 0;
freqs.old = cpu_policy->cur;
freqs.new = cur_freq;
- blocking_notifier_call_chain(&cpufreq_transition_notifier_list,
+ srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
CPUFREQ_SUSPENDCHANGE, &freqs);
adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs);
static int cpufreq_resume(struct sys_device * sysdev)
{
int cpu = sysdev->id;
- unsigned int ret = 0;
+ int ret = 0;
struct cpufreq_policy *cpu_policy;
dprintk("resuming cpu %u\n", cpu);
freqs.old = cpu_policy->cur;
freqs.new = cur_freq;
- blocking_notifier_call_chain(
+ srcu_notifier_call_chain(
&cpufreq_transition_notifier_list,
CPUFREQ_RESUMECHANGE, &freqs);
adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs);
switch (list) {
case CPUFREQ_TRANSITION_NOTIFIER:
- ret = blocking_notifier_chain_register(
+ ret = srcu_notifier_chain_register(
&cpufreq_transition_notifier_list, nb);
break;
case CPUFREQ_POLICY_NOTIFIER:
switch (list) {
case CPUFREQ_TRANSITION_NOTIFIER:
- ret = blocking_notifier_chain_unregister(
+ ret = srcu_notifier_chain_unregister(
&cpufreq_transition_notifier_list, nb);
break;
case CPUFREQ_POLICY_NOTIFIER:
*********************************************************************/
-/* Must be called with lock_cpu_hotplug held */
int __cpufreq_driver_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
if (!policy)
return -EINVAL;
- lock_cpu_hotplug();
- mutex_lock(&policy->lock);
+ if (unlikely(lock_policy_rwsem_write(policy->cpu)))
+ return -EINVAL;
ret = __cpufreq_driver_target(policy, target_freq, relation);
- mutex_unlock(&policy->lock);
- unlock_cpu_hotplug();
+ unlock_policy_rwsem_write(policy->cpu);
cpufreq_cpu_put(policy);
return ret;
}
EXPORT_SYMBOL_GPL(cpufreq_driver_target);
+int __cpufreq_driver_getavg(struct cpufreq_policy *policy)
+{
+ int ret = 0;
+
+ policy = cpufreq_cpu_get(policy->cpu);
+ if (!policy)
+ return -EINVAL;
+
+ if (cpu_online(policy->cpu) && cpufreq_driver->getavg)
+ ret = cpufreq_driver->getavg(policy->cpu);
+
+ cpufreq_cpu_put(policy);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg);
+
/*
- * Locking: Must be called with the lock_cpu_hotplug() lock held
* when "event" is CPUFREQ_GOV_LIMITS
*/
-static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event)
+static int __cpufreq_governor(struct cpufreq_policy *policy,
+ unsigned int event)
{
int ret;
if (!try_module_get(policy->governor->owner))
return -EINVAL;
- dprintk("__cpufreq_governor for CPU %u, event %u\n", policy->cpu, event);
+ dprintk("__cpufreq_governor for CPU %u, event %u\n",
+ policy->cpu, event);
ret = policy->governor->governor(policy, event);
- /* we keep one module reference alive for each CPU governed by this CPU */
+ /* we keep one module reference alive for
+ each CPU governed by this CPU */
if ((event != CPUFREQ_GOV_START) || ret)
module_put(policy->governor->owner);
if ((event == CPUFREQ_GOV_STOP) && !ret)
if (!cpu_policy)
return -EINVAL;
- mutex_lock(&cpu_policy->lock);
memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy));
- mutex_unlock(&cpu_policy->lock);
cpufreq_cpu_put(cpu_policy);
return 0;
/*
- * Locking: Must be called with the lock_cpu_hotplug() lock held
+ * data : current policy.
+ * policy : policy to be set.
*/
-static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy)
+static int __cpufreq_set_policy(struct cpufreq_policy *data,
+ struct cpufreq_policy *policy)
{
int ret = 0;
dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu,
policy->min, policy->max);
- memcpy(&policy->cpuinfo, &data->cpuinfo, sizeof(struct cpufreq_cpuinfo));
+ memcpy(&policy->cpuinfo, &data->cpuinfo,
+ sizeof(struct cpufreq_cpuinfo));
if (policy->min > data->min && policy->min > policy->max) {
ret = -EINVAL;
data->min = policy->min;
data->max = policy->max;
- dprintk("new min and max freqs are %u - %u kHz\n", data->min, data->max);
+ dprintk("new min and max freqs are %u - %u kHz\n",
+ data->min, data->max);
if (cpufreq_driver->setpolicy) {
data->policy = policy->policy;
data->governor = policy->governor;
if (__cpufreq_governor(data, CPUFREQ_GOV_START)) {
/* new governor failed, so re-start old one */
- dprintk("starting governor %s failed\n", data->governor->name);
+ dprintk("starting governor %s failed\n",
+ data->governor->name);
if (old_gov) {
data->governor = old_gov;
- __cpufreq_governor(data, CPUFREQ_GOV_START);
+ __cpufreq_governor(data,
+ CPUFREQ_GOV_START);
}
ret = -EINVAL;
goto error_out;
}
/**
- * cpufreq_set_policy - set a new CPUFreq policy
- * @policy: policy to be set.
- *
- * Sets a new CPU frequency and voltage scaling policy.
- */
-int cpufreq_set_policy(struct cpufreq_policy *policy)
-{
- int ret = 0;
- struct cpufreq_policy *data;
-
- if (!policy)
- return -EINVAL;
-
- data = cpufreq_cpu_get(policy->cpu);
- if (!data)
- return -EINVAL;
-
- lock_cpu_hotplug();
-
- /* lock this CPU */
- mutex_lock(&data->lock);
-
- ret = __cpufreq_set_policy(data, policy);
- data->user_policy.min = data->min;
- data->user_policy.max = data->max;
- data->user_policy.policy = data->policy;
- data->user_policy.governor = data->governor;
-
- mutex_unlock(&data->lock);
-
- unlock_cpu_hotplug();
- cpufreq_cpu_put(data);
-
- return ret;
-}
-EXPORT_SYMBOL(cpufreq_set_policy);
-
-
-/**
* cpufreq_update_policy - re-evaluate an existing cpufreq policy
* @cpu: CPU which shall be re-evaluated
*
if (!data)
return -ENODEV;
- lock_cpu_hotplug();
- mutex_lock(&data->lock);
+ if (unlikely(lock_policy_rwsem_write(cpu)))
+ return -EINVAL;
dprintk("updating policy for CPU %u\n", cpu);
memcpy(&policy, data, sizeof(struct cpufreq_policy));
data->cur = policy.cur;
} else {
if (data->cur != policy.cur)
- cpufreq_out_of_sync(cpu, data->cur, policy.cur);
+ cpufreq_out_of_sync(cpu, data->cur,
+ policy.cur);
}
}
ret = __cpufreq_set_policy(data, &policy);
- mutex_unlock(&data->lock);
- unlock_cpu_hotplug();
+ unlock_policy_rwsem_write(cpu);
+
cpufreq_cpu_put(data);
return ret;
}
EXPORT_SYMBOL(cpufreq_update_policy);
-#ifdef CONFIG_HOTPLUG_CPU
static int cpufreq_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
- struct cpufreq_policy *policy;
struct sys_device *sys_dev;
sys_dev = get_cpu_sysdev(cpu);
-
if (sys_dev) {
switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
cpufreq_add_dev(sys_dev);
break;
case CPU_DOWN_PREPARE:
- /*
- * We attempt to put this cpu in lowest frequency
- * possible before going down. This will permit
- * hardware-managed P-State to switch other related
- * threads to min or higher speeds if possible.
- */
- policy = cpufreq_cpu_data[cpu];
- if (policy) {
- cpufreq_driver_target(policy, policy->min,
- CPUFREQ_RELATION_H);
- }
+ case CPU_DOWN_PREPARE_FROZEN:
+ if (unlikely(lock_policy_rwsem_write(cpu)))
+ BUG();
+
+ __cpufreq_remove_dev(sys_dev);
break;
- case CPU_DEAD:
- cpufreq_remove_dev(sys_dev);
+ case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
+ cpufreq_add_dev(sys_dev);
break;
}
}
{
.notifier_call = cpufreq_cpu_callback,
};
-#endif /* CONFIG_HOTPLUG_CPU */
/*********************************************************************
* REGISTER / UNREGISTER CPUFREQ DRIVER *
/* if all ->init() calls failed, unregister */
if (ret) {
- dprintk("no CPU initialized for driver %s\n", driver_data->name);
- sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
+ dprintk("no CPU initialized for driver %s\n",
+ driver_data->name);
+ sysdev_driver_unregister(&cpu_sysdev_class,
+ &cpufreq_sysdev_driver);
spin_lock_irqsave(&cpufreq_driver_lock, flags);
cpufreq_driver = NULL;
return 0;
}
EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
+
+static int __init cpufreq_core_init(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ per_cpu(policy_cpu, cpu) = -1;
+ init_rwsem(&per_cpu(cpu_policy_rwsem, cpu));
+ }
+ return 0;
+}
+
+core_initcall(cpufreq_core_init);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff