* Copyright (C) 2001 Russell King
* (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
*
+ * Oct 2005 - Ashok Raj <ashok.raj@intel.com>
+ * Added handling for CPU hotplug
+ * Feb 2006 - Jacob Shin <jacob.shin@amd.com>
+ * Fix handling for CPU hotplug -- affected CPUs
+ *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
-#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#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-dependend low
+ * The "cpufreq driver" - the arch- or hardware-dependent low
* level driver of CPUFreq support, and its spinlock. This lock
* also protects the cpufreq_cpu_data array.
*/
-static struct cpufreq_driver *cpufreq_driver;
-static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS];
+static struct cpufreq_driver *cpufreq_driver;
+static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
+#ifdef CONFIG_HOTPLUG_CPU
+/* This one keeps track of the previously set governor of a removed CPU */
+static DEFINE_PER_CPU(struct cpufreq_governor *, cpufreq_cpu_governor);
+#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 inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci);
+static int __cpufreq_governor(struct cpufreq_policy *policy,
+ unsigned int event);
+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
- * validation process for a new CPU frequency policy; the
+ * Two notifier lists: the "policy" list is involved in the
+ * validation process for a new CPU frequency policy; the
* "transition" list for kernel code that needs to handle
* changes to devices when the CPU clock speed changes.
* The mutex locks both lists.
*/
-static struct notifier_block *cpufreq_policy_notifier_list;
-static struct notifier_block *cpufreq_transition_notifier_list;
-static DECLARE_RWSEM (cpufreq_notifier_rwsem);
+static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
+static struct srcu_notifier_head cpufreq_transition_notifier_list;
+static bool init_cpufreq_transition_notifier_list_called;
+static int __init init_cpufreq_transition_notifier_list(void)
+{
+ srcu_init_notifier_head(&cpufreq_transition_notifier_list);
+ init_cpufreq_transition_notifier_list_called = true;
+ return 0;
+}
+pure_initcall(init_cpufreq_transition_notifier_list);
static LIST_HEAD(cpufreq_governor_list);
-static DECLARE_MUTEX (cpufreq_governor_sem);
+static DEFINE_MUTEX(cpufreq_governor_mutex);
-struct cpufreq_policy * cpufreq_cpu_get(unsigned int cpu)
+struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
{
struct cpufreq_policy *data;
unsigned long flags;
- if (cpu >= NR_CPUS)
+ if (cpu >= nr_cpu_ids)
goto err_out;
/* get the cpufreq driver */
/* get the CPU */
- data = cpufreq_cpu_data[cpu];
+ data = per_cpu(cpufreq_cpu_data, cpu);
if (!data)
goto err_out_put_module;
if (!kobject_get(&data->kobj))
goto err_out_put_module;
-
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
-
return data;
- err_out_put_module:
+err_out_put_module:
module_put(cpufreq_driver->owner);
- err_out_unlock:
+err_out_unlock:
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
- err_out:
+err_out:
return NULL;
}
EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
+
void cpufreq_cpu_put(struct cpufreq_policy *data)
{
kobject_put(&data->kobj);
static unsigned int disable_ratelimit = 1;
static DEFINE_SPINLOCK(disable_ratelimit_lock);
-static inline void cpufreq_debug_enable_ratelimit(void)
+static void cpufreq_debug_enable_ratelimit(void)
{
unsigned long flags;
spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
}
-static inline void cpufreq_debug_disable_ratelimit(void)
+static void cpufreq_debug_disable_ratelimit(void)
{
unsigned long flags;
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;
unsigned int len;
unsigned long flags;
-
+
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 */
*
* This function alters the system "loops_per_jiffy" for the clock
* speed change. Note that loops_per_jiffy cannot be updated on SMP
- * systems as each CPU might be scaled differently. So, use the arch
+ * systems as each CPU might be scaled differently. So, use the arch
* per-CPU loops_per_jiffy value wherever possible.
*/
#ifndef CONFIG_SMP
static unsigned long l_p_j_ref;
static unsigned int l_p_j_ref_freq;
-static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
+static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
{
if (ci->flags & CPUFREQ_CONST_LOOPS)
return;
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
/**
- * cpufreq_notify_transition - call notifier chain and adjust_jiffies on frequency transition
+ * cpufreq_notify_transition - call notifier chain and adjust_jiffies
+ * on frequency transition.
*
- * This function calls the transition notifiers and the "adjust_jiffies" function. It is called
- * twice on all CPU frequency changes that have external effects.
+ * This function calls the transition notifiers and the "adjust_jiffies"
+ * function. It is called twice on all CPU frequency changes that have
+ * external effects.
*/
void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
{
+ struct cpufreq_policy *policy;
+
BUG_ON(irqs_disabled());
freqs->flags = cpufreq_driver->flags;
- dprintk("notification %u of frequency transition to %u kHz\n", state, freqs->new);
+ dprintk("notification %u of frequency transition to %u kHz\n",
+ state, freqs->new);
- down_read(&cpufreq_notifier_rwsem);
+ policy = per_cpu(cpufreq_cpu_data, freqs->cpu);
switch (state) {
+
case CPUFREQ_PRECHANGE:
- /* detect if the driver reported a value as "old frequency" which
- * is not equal to what the cpufreq core thinks is "old frequency".
+ /* detect if the driver reported a value as "old frequency"
+ * which is not equal to what the cpufreq core thinks is
+ * "old frequency".
*/
if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
- if ((likely(cpufreq_cpu_data[freqs->cpu])) &&
- (likely(cpufreq_cpu_data[freqs->cpu]->cpu == freqs->cpu)) &&
- (likely(cpufreq_cpu_data[freqs->cpu]->cur)) &&
- (unlikely(freqs->old != cpufreq_cpu_data[freqs->cpu]->cur)))
- {
- dprintk(KERN_WARNING "Warning: CPU frequency is %u, "
- "cpufreq assumed %u kHz.\n", freqs->old, cpufreq_cpu_data[freqs->cpu]->cur);
- freqs->old = cpufreq_cpu_data[freqs->cpu]->cur;
+ if ((policy) && (policy->cpu == freqs->cpu) &&
+ (policy->cur) && (policy->cur != freqs->old)) {
+ dprintk("Warning: CPU frequency is"
+ " %u, cpufreq assumed %u kHz.\n",
+ freqs->old, policy->cur);
+ freqs->old = policy->cur;
}
}
- notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_PRECHANGE, freqs);
+ 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);
- notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_POSTCHANGE, freqs);
- if ((likely(cpufreq_cpu_data[freqs->cpu])) &&
- (likely(cpufreq_cpu_data[freqs->cpu]->cpu == freqs->cpu)))
- cpufreq_cpu_data[freqs->cpu]->cur = freqs->new;
+ srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
+ CPUFREQ_POSTCHANGE, freqs);
+ if (likely(policy) && likely(policy->cpu == freqs->cpu))
+ policy->cur = freqs->new;
break;
}
- up_read(&cpufreq_notifier_rwsem);
}
EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
* SYSFS INTERFACE *
*********************************************************************/
+static struct cpufreq_governor *__find_governor(const char *str_governor)
+{
+ struct cpufreq_governor *t;
+
+ list_for_each_entry(t, &cpufreq_governor_list, governor_list)
+ if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN))
+ return t;
+
+ return NULL;
+}
+
/**
* cpufreq_parse_governor - parse a governor string
*/
-static int cpufreq_parse_governor (char *str_governor, unsigned int *policy,
+static int cpufreq_parse_governor(char *str_governor, unsigned int *policy,
struct cpufreq_governor **governor)
{
+ int err = -EINVAL;
+
if (!cpufreq_driver)
- return -EINVAL;
+ goto out;
+
if (cpufreq_driver->setpolicy) {
if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
*policy = CPUFREQ_POLICY_PERFORMANCE;
- return 0;
- } else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
+ err = 0;
+ } else if (!strnicmp(str_governor, "powersave",
+ CPUFREQ_NAME_LEN)) {
*policy = CPUFREQ_POLICY_POWERSAVE;
- return 0;
+ err = 0;
}
- return -EINVAL;
- } else {
+ } else if (cpufreq_driver->target) {
struct cpufreq_governor *t;
- down(&cpufreq_governor_sem);
- if (!cpufreq_driver || !cpufreq_driver->target)
- goto out;
- list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
- if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) {
- *governor = t;
- up(&cpufreq_governor_sem);
- return 0;
+
+ mutex_lock(&cpufreq_governor_mutex);
+
+ t = __find_governor(str_governor);
+
+ if (t == NULL) {
+ char *name = kasprintf(GFP_KERNEL, "cpufreq_%s",
+ str_governor);
+
+ if (name) {
+ int ret;
+
+ mutex_unlock(&cpufreq_governor_mutex);
+ ret = request_module("%s", name);
+ mutex_lock(&cpufreq_governor_mutex);
+
+ if (ret == 0)
+ t = __find_governor(str_governor);
}
+
+ kfree(name);
}
- out:
- up(&cpufreq_governor_sem);
- }
- return -EINVAL;
-}
-EXPORT_SYMBOL_GPL(cpufreq_parse_governor);
+ if (t != NULL) {
+ *governor = t;
+ err = 0;
+ }
-/* drivers/base/cpu.c */
-extern struct sysdev_class cpu_sysdev_class;
+ mutex_unlock(&cpufreq_governor_mutex);
+ }
+out:
+ return err;
+}
/**
- * 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".
*/
-#define show_one(file_name, object) \
-static ssize_t show_##file_name \
-(struct cpufreq_policy * policy, char *buf) \
-{ \
- return sprintf (buf, "%u\n", policy->object); \
+#define show_one(file_name, object) \
+static ssize_t show_##file_name \
+(struct cpufreq_policy *policy, char *buf) \
+{ \
+ return sprintf(buf, "%u\n", policy->object); \
}
show_one(cpuinfo_min_freq, cpuinfo.min_freq);
show_one(cpuinfo_max_freq, cpuinfo.max_freq);
+show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
show_one(scaling_min_freq, min);
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);
+
/**
* cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
*/
#define store_one(file_name, object) \
static ssize_t store_##file_name \
-(struct cpufreq_policy * policy, const char *buf, size_t count) \
+(struct cpufreq_policy *policy, const char *buf, size_t count) \
{ \
unsigned int ret = -EINVAL; \
struct cpufreq_policy new_policy; \
if (ret) \
return -EINVAL; \
\
- ret = sscanf (buf, "%u", &new_policy.object); \
+ ret = sscanf(buf, "%u", &new_policy.object); \
if (ret != 1) \
return -EINVAL; \
\
- ret = cpufreq_set_policy(&new_policy); \
+ ret = __cpufreq_set_policy(policy, &new_policy); \
+ policy->user_policy.object = policy->object; \
\
return ret ? ret : count; \
}
-store_one(scaling_min_freq,min);
-store_one(scaling_max_freq,max);
+store_one(scaling_min_freq, min);
+store_one(scaling_max_freq, max);
/**
* 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)
+ if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
return sprintf(buf, "powersave\n");
else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
return sprintf(buf, "performance\n");
else if (policy->governor)
- return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name);
+ return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n",
+ policy->governor->name);
return -EINVAL;
}
/**
* store_scaling_governor - store policy for the specified CPU
*/
-static ssize_t store_scaling_governor (struct cpufreq_policy * policy,
- const char *buf, size_t count)
+static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
+ const char *buf, size_t count)
{
unsigned int ret = -EINVAL;
char str_governor[16];
if (ret)
return ret;
- ret = sscanf (buf, "%15s", str_governor);
+ ret = sscanf(buf, "%15s", str_governor);
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;
- ret = cpufreq_set_policy(&new_policy);
+ /* Do not use cpufreq_set_policy here or the user_policy.max
+ will be wrongly overridden */
+ ret = __cpufreq_set_policy(policy, &new_policy);
- return ret ? ret : count;
+ policy->user_policy.policy = policy->policy;
+ policy->user_policy.governor = policy->governor;
+
+ if (ret)
+ return ret;
+ else
+ return count;
}
/**
* show_scaling_driver - show the cpufreq driver currently loaded
*/
-static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf)
+static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
{
return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name);
}
/**
* show_scaling_available_governors - show the available CPUfreq governors
*/
-static ssize_t show_scaling_available_governors (struct cpufreq_policy * policy,
- char *buf)
+static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
+ char *buf)
{
ssize_t i = 0;
struct cpufreq_governor *t;
}
list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
- if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2)))
+ if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
+ - (CPUFREQ_NAME_LEN + 2)))
goto out;
i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name);
}
- out:
+out:
i += sprintf(&buf[i], "\n");
return i;
}
-/**
- * show_affected_cpus - show the CPUs affected by each transition
- */
-static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf)
+
+static ssize_t show_cpus(const struct cpumask *mask, char *buf)
{
ssize_t i = 0;
unsigned int cpu;
- for_each_cpu_mask(cpu, policy->cpus) {
+ for_each_cpu(cpu, mask) {
if (i)
i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
if (i >= (PAGE_SIZE - 5))
- break;
+ break;
}
i += sprintf(&buf[i], "\n");
return i;
}
+/**
+ * show_related_cpus - show the CPUs affected by each transition even if
+ * hw coordination is in use
+ */
+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);
+}
+
+/**
+ * show_affected_cpus - show the CPUs affected by each transition
+ */
+static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
+{
+ return show_cpus(policy->cpus, buf);
+}
+
+static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
+ const char *buf, size_t count)
+{
+ unsigned int freq = 0;
+ unsigned int ret;
+
+ if (!policy->governor || !policy->governor->store_setspeed)
+ return -EINVAL;
+
+ ret = sscanf(buf, "%u", &freq);
+ if (ret != 1)
+ return -EINVAL;
+
+ policy->governor->store_setspeed(policy, freq);
+
+ return count;
+}
+
+static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
+{
+ if (!policy->governor || !policy->governor->show_setspeed)
+ return sprintf(buf, "<unsupported>\n");
+
+ return policy->governor->show_setspeed(policy, buf);
+}
#define define_one_ro(_name) \
static struct freq_attr _name = \
define_one_ro0400(cpuinfo_cur_freq);
define_one_ro(cpuinfo_min_freq);
define_one_ro(cpuinfo_max_freq);
+define_one_ro(cpuinfo_transition_latency);
define_one_ro(scaling_available_governors);
define_one_ro(scaling_driver);
define_one_ro(scaling_cur_freq);
+define_one_ro(related_cpus);
define_one_ro(affected_cpus);
define_one_rw(scaling_min_freq);
define_one_rw(scaling_max_freq);
define_one_rw(scaling_governor);
+define_one_rw(scaling_setspeed);
-static struct attribute * default_attrs[] = {
+static struct attribute *default_attrs[] = {
&cpuinfo_min_freq.attr,
&cpuinfo_max_freq.attr,
+ &cpuinfo_transition_latency.attr,
&scaling_min_freq.attr,
&scaling_max_freq.attr,
&affected_cpus.attr,
+ &related_cpus.attr,
&scaling_governor.attr,
&scaling_driver.attr,
&scaling_available_governors.attr,
+ &scaling_setspeed.attr,
NULL
};
-#define to_policy(k) container_of(k,struct cpufreq_policy,kobj)
-#define to_attr(a) container_of(a,struct freq_attr,attr)
+#define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
+#define to_attr(a) container_of(a, struct freq_attr, attr)
-static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf)
+static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
{
- struct cpufreq_policy * policy = to_policy(kobj);
- struct freq_attr * fattr = to_attr(attr);
- ssize_t ret;
+ struct cpufreq_policy *policy = to_policy(kobj);
+ struct freq_attr *fattr = to_attr(attr);
+ ssize_t ret = -EINVAL;
policy = cpufreq_cpu_get(policy->cpu);
if (!policy)
- return -EINVAL;
- ret = fattr->show ? fattr->show(policy,buf) : -EIO;
+ goto no_policy;
+
+ if (lock_policy_rwsem_read(policy->cpu) < 0)
+ goto fail;
+
+ if (fattr->show)
+ ret = fattr->show(policy, buf);
+ else
+ ret = -EIO;
+
+ unlock_policy_rwsem_read(policy->cpu);
+fail:
cpufreq_cpu_put(policy);
+no_policy:
return ret;
}
-static ssize_t store(struct kobject * kobj, struct attribute * attr,
- const char * buf, size_t count)
+static ssize_t store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t count)
{
- struct cpufreq_policy * policy = to_policy(kobj);
- struct freq_attr * fattr = to_attr(attr);
- ssize_t ret;
+ struct cpufreq_policy *policy = to_policy(kobj);
+ struct freq_attr *fattr = to_attr(attr);
+ ssize_t ret = -EINVAL;
policy = cpufreq_cpu_get(policy->cpu);
if (!policy)
- return -EINVAL;
- ret = fattr->store ? fattr->store(policy,buf,count) : -EIO;
+ goto no_policy;
+
+ if (lock_policy_rwsem_write(policy->cpu) < 0)
+ goto fail;
+
+ if (fattr->store)
+ ret = fattr->store(policy, buf, count);
+ else
+ ret = -EIO;
+
+ unlock_policy_rwsem_write(policy->cpu);
+fail:
cpufreq_cpu_put(policy);
+no_policy:
return ret;
}
-static void cpufreq_sysfs_release(struct kobject * kobj)
+static void cpufreq_sysfs_release(struct kobject *kobj)
{
- struct cpufreq_policy * policy = to_policy(kobj);
+ struct cpufreq_policy *policy = to_policy(kobj);
dprintk("last reference is dropped\n");
complete(&policy->kobj_unregister);
}
/**
* cpufreq_add_dev - add a CPU device
*
- * Adds the cpufreq interface for a CPU device.
+ * Adds the cpufreq interface for a CPU device.
*/
-static int cpufreq_add_dev (struct sys_device * sys_dev)
+static int cpufreq_add_dev(struct sys_device *sys_dev)
{
unsigned int cpu = sys_dev->id;
int ret = 0;
struct cpufreq_policy new_policy;
struct cpufreq_policy *policy;
struct freq_attr **drv_attr;
+ struct sys_device *cpu_sys_dev;
unsigned long flags;
unsigned int j;
+#ifdef CONFIG_SMP
+ struct cpufreq_policy *managed_policy;
+#endif
+
+ if (cpu_is_offline(cpu))
+ return 0;
cpufreq_debug_disable_ratelimit();
dprintk("adding CPU %u\n", cpu);
* CPU because it is in the same boat. */
policy = cpufreq_cpu_get(cpu);
if (unlikely(policy)) {
- dprintk("CPU already managed, adding link\n");
- sysfs_create_link(&sys_dev->kobj, &policy->kobj, "cpufreq");
+ cpufreq_cpu_put(policy);
cpufreq_debug_enable_ratelimit();
return 0;
}
goto module_out;
}
- policy = kmalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
+ policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
if (!policy) {
ret = -ENOMEM;
goto nomem_out;
}
- memset(policy, 0, sizeof(struct cpufreq_policy));
+ if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) {
+ kfree(policy);
+ ret = -ENOMEM;
+ goto nomem_out;
+ }
+ if (!alloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) {
+ free_cpumask_var(policy->cpus);
+ kfree(policy);
+ ret = -ENOMEM;
+ goto nomem_out;
+ }
policy->cpu = cpu;
- policy->cpus = cpumask_of_cpu(cpu);
+ cpumask_copy(policy->cpus, cpumask_of(cpu));
+
+ /* Initially set CPU itself as the policy_cpu */
+ per_cpu(policy_cpu, cpu) = cpu;
+ lock_policy_rwsem_write(cpu);
- init_MUTEX_LOCKED(&policy->lock);
init_completion(&policy->kobj_unregister);
- INIT_WORK(&policy->update, handle_update, (void *)(long)cpu);
+ INIT_WORK(&policy->update, handle_update);
+ /* Set governor before ->init, so that driver could check it */
+ policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
/* call driver. From then on the cpufreq must be able
* to accept all calls to ->verify and ->setpolicy for this CPU
*/
dprintk("initialization failed\n");
goto err_out;
}
+ policy->user_policy.min = policy->min;
+ policy->user_policy.max = policy->max;
+
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_START, policy);
+
+#ifdef CONFIG_SMP
+
+#ifdef CONFIG_HOTPLUG_CPU
+ if (per_cpu(cpufreq_cpu_governor, cpu)) {
+ policy->governor = per_cpu(cpufreq_cpu_governor, cpu);
+ dprintk("Restoring governor %s for cpu %d\n",
+ policy->governor->name, cpu);
+ }
+#endif
+
+ for_each_cpu(j, policy->cpus) {
+ if (cpu == j)
+ continue;
+
+ /* Check for existing affected CPUs.
+ * They may not be aware of it due to CPU Hotplug.
+ */
+ managed_policy = cpufreq_cpu_get(j); /* FIXME: Where is this released? What about error paths? */
+ 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);
+ cpumask_copy(managed_policy->cpus, policy->cpus);
+ per_cpu(cpufreq_cpu_data, cpu) = managed_policy;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ dprintk("CPU already managed, adding link\n");
+ ret = sysfs_create_link(&sys_dev->kobj,
+ &managed_policy->kobj,
+ "cpufreq");
+ if (ret)
+ goto err_out_driver_exit;
+ cpufreq_debug_enable_ratelimit();
+ ret = 0;
+ goto err_out_driver_exit; /* call driver->exit() */
+ }
+ }
+#endif
memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));
/* prepare interface data */
- policy->kobj.parent = &sys_dev->kobj;
- policy->kobj.ktype = &ktype_cpufreq;
- strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN);
-
- ret = kobject_register(&policy->kobj);
+ ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj,
+ "cpufreq");
if (ret)
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)
- cpufreq_cpu_data[j] = policy;
+ for_each_cpu(j, policy->cpus) {
+ per_cpu(cpufreq_cpu_data, j) = policy;
+ per_cpu(policy_cpu, j) = policy->cpu;
+ }
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ /* symlink affected CPUs */
+ for_each_cpu(j, policy->cpus) {
+ if (j == cpu)
+ continue;
+ if (!cpu_online(j))
+ continue;
+
+ dprintk("CPU %u already managed, adding link\n", j);
+ cpufreq_cpu_get(cpu);
+ cpu_sys_dev = get_cpu_sysdev(j);
+ ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj,
+ "cpufreq");
+ if (ret)
+ goto err_out_unregister;
+ }
+
policy->governor = NULL; /* to assure that the starting sequence is
* run in cpufreq_set_policy */
- up(&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;
+
if (ret) {
dprintk("setting policy failed\n");
goto err_out_unregister;
}
+ unlock_policy_rwsem_write(cpu);
+
+ kobject_uevent(&policy->kobj, KOBJ_ADD);
module_put(cpufreq_driver->owner);
dprintk("initialization complete\n");
cpufreq_debug_enable_ratelimit();
-
+
return 0;
err_out_unregister:
spin_lock_irqsave(&cpufreq_driver_lock, flags);
- for_each_cpu_mask(j, policy->cpus)
- cpufreq_cpu_data[j] = NULL;
+ for_each_cpu(j, policy->cpus)
+ per_cpu(cpufreq_cpu_data, j) = NULL;
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
- kobject_unregister(&policy->kobj);
+ kobject_put(&policy->kobj);
wait_for_completion(&policy->kobj_unregister);
err_out_driver_exit:
cpufreq_driver->exit(policy);
err_out:
+ unlock_policy_rwsem_write(cpu);
kfree(policy);
nomem_out:
module_put(cpufreq_driver->owner);
- module_out:
+module_out:
cpufreq_debug_enable_ratelimit();
return ret;
}
/**
- * 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;
struct cpufreq_policy *data;
- struct sys_device *cpu_sys_dev;
#ifdef CONFIG_SMP
+ struct sys_device *cpu_sys_dev;
unsigned int j;
#endif
dprintk("unregistering CPU %u\n", cpu);
spin_lock_irqsave(&cpufreq_driver_lock, flags);
- data = cpufreq_cpu_data[cpu];
+ data = per_cpu(cpufreq_cpu_data, cpu);
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;
+ per_cpu(cpufreq_cpu_data, cpu) = NULL;
#ifdef CONFIG_SMP
/* if this isn't the CPU which is the parent of the kobj, we
- * only need to unlink, put and exit
+ * only need to unlink, put and exit
*/
if (unlikely(cpu != data->cpu)) {
dprintk("removing link\n");
+ cpumask_clear_cpu(cpu, data->cpus);
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
sysfs_remove_link(&sys_dev->kobj, "cpufreq");
cpufreq_cpu_put(data);
cpufreq_debug_enable_ratelimit();
+ unlock_policy_rwsem_write(cpu);
return 0;
}
#endif
+#ifdef CONFIG_SMP
- if (!kobject_get(&data->kobj)) {
- spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
- cpufreq_debug_enable_ratelimit();
- return -EFAULT;
- }
+#ifdef CONFIG_HOTPLUG_CPU
+ per_cpu(cpufreq_cpu_governor, cpu) = data->governor;
+#endif
-#ifdef CONFIG_SMP
/* 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
- * links afterwards.
+ * per_cpu(cpufreq_cpu_data) while holding the lock, and remove
+ * the sysfs links afterwards.
*/
- if (unlikely(cpus_weight(data->cpus) > 1)) {
- for_each_cpu_mask(j, data->cpus) {
+ if (unlikely(cpumask_weight(data->cpus) > 1)) {
+ for_each_cpu(j, data->cpus) {
if (j == cpu)
continue;
- cpufreq_cpu_data[j] = NULL;
+ per_cpu(cpufreq_cpu_data, j) = NULL;
}
}
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
- if (unlikely(cpus_weight(data->cpus) > 1)) {
- for_each_cpu_mask(j, data->cpus) {
+ if (unlikely(cpumask_weight(data->cpus) > 1)) {
+ for_each_cpu(j, data->cpus) {
if (j == cpu)
continue;
dprintk("removing link for cpu %u\n", j);
+#ifdef CONFIG_HOTPLUG_CPU
+ per_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
- down(&data->lock);
+ unlock_policy_rwsem_write(cpu);
+
if (cpufreq_driver->target)
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
- cpufreq_driver->target = NULL;
- up(&data->lock);
-
- kobject_unregister(&data->kobj);
kobject_put(&data->kobj);
/* we need to make sure that the underlying kobj is actually
- * not referenced anymore by anybody before we proceed with
+ * not referenced anymore by anybody before we proceed with
* unloading.
*/
dprintk("waiting for dropping of refcount\n");
if (cpufreq_driver->exit)
cpufreq_driver->exit(data);
+ free_cpumask_var(data->related_cpus);
+ free_cpumask_var(data->cpus);
kfree(data);
+ per_cpu(cpufreq_cpu_data, cpu) = NULL;
cpufreq_debug_enable_ratelimit();
-
return 0;
}
-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);
}
* @old_freq: CPU frequency the kernel thinks the CPU runs at
* @new_freq: CPU frequency the CPU actually runs at
*
- * We adjust to current frequency first, and need to clean up later. So either call
- * to cpufreq_update_policy() or schedule handle_update()).
+ * 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;
- dprintk(KERN_WARNING "Warning: CPU frequency out of sync: cpufreq and timing "
+ dprintk("Warning: CPU frequency out of sync: cpufreq and timing "
"core thinks of %u, is %u kHz.\n", old_freq, new_freq);
freqs.cpu = cpu;
}
-/**
- * cpufreq_get - get the current CPU frequency (in kHz)
+/**
+ * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
* @cpu: CPU number
*
- * Get the CPU current (static) CPU frequency
+ * This is the last known freq, without actually getting it from the driver.
+ * Return value will be same as what is shown in scaling_cur_freq in sysfs.
*/
-unsigned int cpufreq_get(unsigned int cpu)
+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)
- return 0;
+ if (policy) {
+ ret_freq = policy->cur;
+ cpufreq_cpu_put(policy);
+ }
- if (!cpufreq_driver->get)
- goto out;
+ return ret_freq;
+}
+EXPORT_SYMBOL(cpufreq_quick_get);
- down(&policy->lock);
- ret = cpufreq_driver->get(cpu);
+static unsigned int __cpufreq_get(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
+ unsigned int ret_freq = 0;
- 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);
+ 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);
}
}
- up(&policy->lock);
+ return ret_freq;
+}
- out:
- cpufreq_cpu_put(policy);
+/**
+ * cpufreq_get - get the current CPU frequency (in kHz)
+ * @cpu: CPU number
+ *
+ * Get the CPU current (static) CPU frequency
+ */
+unsigned int cpufreq_get(unsigned int cpu)
+{
+ unsigned int ret_freq = 0;
+ struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+
+ if (!policy)
+ goto out;
+
+ if (unlikely(lock_policy_rwsem_read(cpu)))
+ goto out_policy;
+
+ ret_freq = __cpufreq_get(cpu);
+
+ unlock_policy_rwsem_read(cpu);
- return (ret);
+out_policy:
+ cpufreq_cpu_put(policy);
+out:
+ return ret_freq;
}
EXPORT_SYMBOL(cpufreq_get);
* cpufreq_suspend - let the low level driver prepare for suspend
*/
-static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
+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;
return -EINVAL;
/* only handle each CPU group once */
- if (unlikely(cpu_policy->cpu != cpu)) {
- cpufreq_cpu_put(cpu_policy);
- return 0;
- }
+ if (unlikely(cpu_policy->cpu != cpu))
+ goto out;
if (cpufreq_driver->suspend) {
ret = cpufreq_driver->suspend(cpu_policy, pmsg);
if (ret) {
printk(KERN_ERR "cpufreq: suspend failed in ->suspend "
"step on CPU %u\n", cpu_policy->cpu);
- cpufreq_cpu_put(cpu_policy);
- return ret;
+ goto out;
}
}
-
if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)
goto out;
struct cpufreq_freqs freqs;
if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN))
- dprintk(KERN_DEBUG "Warning: CPU frequency is %u, "
+ dprintk("Warning: CPU frequency is %u, "
"cpufreq assumed %u kHz.\n",
cur_freq, cpu_policy->cur);
freqs.old = cpu_policy->cur;
freqs.new = cur_freq;
- notifier_call_chain(&cpufreq_transition_notifier_list,
+ srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
CPUFREQ_SUSPENDCHANGE, &freqs);
adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs);
cpu_policy->cur = cur_freq;
}
- out:
+out:
cpufreq_cpu_put(cpu_policy);
- return 0;
+ return ret;
}
/**
* 3.) schedule call cpufreq_update_policy() ASAP as interrupts are
* restored.
*/
-static int cpufreq_resume(struct sys_device * sysdev)
+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);
return -EINVAL;
/* only handle each CPU group once */
- if (unlikely(cpu_policy->cpu != cpu)) {
- cpufreq_cpu_put(cpu_policy);
- return 0;
- }
+ if (unlikely(cpu_policy->cpu != cpu))
+ goto fail;
if (cpufreq_driver->resume) {
ret = cpufreq_driver->resume(cpu_policy);
if (ret) {
printk(KERN_ERR "cpufreq: resume failed in ->resume "
"step on CPU %u\n", cpu_policy->cpu);
- cpufreq_cpu_put(cpu_policy);
- return ret;
+ goto fail;
}
}
struct cpufreq_freqs freqs;
if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN))
- dprintk(KERN_WARNING "Warning: CPU frequency"
+ dprintk("Warning: CPU frequency "
"is %u, cpufreq assumed %u kHz.\n",
cur_freq, cpu_policy->cur);
freqs.old = cpu_policy->cur;
freqs.new = cur_freq;
- notifier_call_chain(&cpufreq_transition_notifier_list,
+ srcu_notifier_call_chain(
+ &cpufreq_transition_notifier_list,
CPUFREQ_RESUMECHANGE, &freqs);
adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs);
out:
schedule_work(&cpu_policy->update);
+fail:
cpufreq_cpu_put(cpu_policy);
return ret;
}
* @nb: notifier function to register
* @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
*
- * Add a driver to one of two lists: either a list of drivers that
+ * Add a driver to one of two lists: either a list of drivers that
* are notified about clock rate changes (once before and once after
* the transition), or a list of drivers that are notified about
* changes in cpufreq policy.
*
* This function may sleep, and has the same return conditions as
- * notifier_chain_register.
+ * blocking_notifier_chain_register.
*/
int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
{
int ret;
- down_write(&cpufreq_notifier_rwsem);
+ WARN_ON(!init_cpufreq_transition_notifier_list_called);
+
switch (list) {
case CPUFREQ_TRANSITION_NOTIFIER:
- ret = notifier_chain_register(&cpufreq_transition_notifier_list, nb);
+ ret = srcu_notifier_chain_register(
+ &cpufreq_transition_notifier_list, nb);
break;
case CPUFREQ_POLICY_NOTIFIER:
- ret = notifier_chain_register(&cpufreq_policy_notifier_list, nb);
+ ret = blocking_notifier_chain_register(
+ &cpufreq_policy_notifier_list, nb);
break;
default:
ret = -EINVAL;
}
- up_write(&cpufreq_notifier_rwsem);
return ret;
}
* Remove a driver from the CPU frequency notifier list.
*
* This function may sleep, and has the same return conditions as
- * notifier_chain_unregister.
+ * blocking_notifier_chain_unregister.
*/
int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
{
int ret;
- down_write(&cpufreq_notifier_rwsem);
switch (list) {
case CPUFREQ_TRANSITION_NOTIFIER:
- ret = notifier_chain_unregister(&cpufreq_transition_notifier_list, nb);
+ ret = srcu_notifier_chain_unregister(
+ &cpufreq_transition_notifier_list, nb);
break;
case CPUFREQ_POLICY_NOTIFIER:
- ret = notifier_chain_unregister(&cpufreq_policy_notifier_list, nb);
+ ret = blocking_notifier_chain_unregister(
+ &cpufreq_policy_notifier_list, nb);
break;
default:
ret = -EINVAL;
}
- up_write(&cpufreq_notifier_rwsem);
return ret;
}
unsigned int relation)
{
int retval = -EINVAL;
- lock_cpu_hotplug();
+
dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
target_freq, relation);
if (cpu_online(policy->cpu) && cpufreq_driver->target)
retval = cpufreq_driver->target(policy, target_freq, relation);
- unlock_cpu_hotplug();
+
return retval;
}
EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
-
int cpufreq_driver_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
- int ret;
+ int ret = -EINVAL;
policy = cpufreq_cpu_get(policy->cpu);
if (!policy)
- return -EINVAL;
+ goto no_policy;
- down(&policy->lock);
+ if (unlikely(lock_policy_rwsem_write(policy->cpu)))
+ goto fail;
ret = __cpufreq_driver_target(policy, target_freq, relation);
- up(&policy->lock);
+ unlock_policy_rwsem_write(policy->cpu);
+fail:
cpufreq_cpu_put(policy);
-
+no_policy:
return ret;
}
EXPORT_SYMBOL_GPL(cpufreq_driver_target);
-
-static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event)
+int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu)
{
- int ret;
+ int ret = 0;
- if (!try_module_get(policy->governor->owner))
+ policy = cpufreq_cpu_get(policy->cpu);
+ if (!policy)
return -EINVAL;
- 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 */
- if ((event != CPUFREQ_GOV_START) || ret)
- module_put(policy->governor->owner);
- if ((event == CPUFREQ_GOV_STOP) && !ret)
- module_put(policy->governor->owner);
+ if (cpu_online(cpu) && cpufreq_driver->getavg)
+ ret = cpufreq_driver->getavg(policy, cpu);
+ cpufreq_cpu_put(policy);
return ret;
}
+EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg);
+/*
+ * when "event" is CPUFREQ_GOV_LIMITS
+ */
-int cpufreq_governor(unsigned int cpu, unsigned int event)
+static int __cpufreq_governor(struct cpufreq_policy *policy,
+ unsigned int event)
{
- int ret = 0;
- struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+ int ret;
- if (!policy)
+ /* Only must be defined when default governor is known to have latency
+ restrictions, like e.g. conservative or ondemand.
+ That this is the case is already ensured in Kconfig
+ */
+#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
+ struct cpufreq_governor *gov = &cpufreq_gov_performance;
+#else
+ struct cpufreq_governor *gov = NULL;
+#endif
+
+ if (policy->governor->max_transition_latency &&
+ policy->cpuinfo.transition_latency >
+ policy->governor->max_transition_latency) {
+ if (!gov)
+ return -EINVAL;
+ else {
+ printk(KERN_WARNING "%s governor failed, too long"
+ " transition latency of HW, fallback"
+ " to %s governor\n",
+ policy->governor->name,
+ gov->name);
+ policy->governor = gov;
+ }
+ }
+
+ if (!try_module_get(policy->governor->owner))
return -EINVAL;
- down(&policy->lock);
- ret = __cpufreq_governor(policy, event);
- up(&policy->lock);
+ dprintk("__cpufreq_governor for CPU %u, event %u\n",
+ policy->cpu, event);
+ ret = policy->governor->governor(policy, event);
- cpufreq_cpu_put(policy);
+ /* 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)
+ module_put(policy->governor->owner);
return ret;
}
-EXPORT_SYMBOL_GPL(cpufreq_governor);
int cpufreq_register_governor(struct cpufreq_governor *governor)
{
- struct cpufreq_governor *t;
+ int err;
if (!governor)
return -EINVAL;
- down(&cpufreq_governor_sem);
-
- list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
- if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) {
- up(&cpufreq_governor_sem);
- return -EBUSY;
- }
- }
- list_add(&governor->governor_list, &cpufreq_governor_list);
+ mutex_lock(&cpufreq_governor_mutex);
- up(&cpufreq_governor_sem);
+ err = -EBUSY;
+ if (__find_governor(governor->name) == NULL) {
+ err = 0;
+ list_add(&governor->governor_list, &cpufreq_governor_list);
+ }
- return 0;
+ mutex_unlock(&cpufreq_governor_mutex);
+ return err;
}
EXPORT_SYMBOL_GPL(cpufreq_register_governor);
if (!governor)
return;
- down(&cpufreq_governor_sem);
+ mutex_lock(&cpufreq_governor_mutex);
list_del(&governor->governor_list);
- up(&cpufreq_governor_sem);
+ mutex_unlock(&cpufreq_governor_mutex);
return;
}
EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
/**
* cpufreq_get_policy - get the current cpufreq_policy
- * @policy: struct cpufreq_policy into which the current cpufreq_policy is written
+ * @policy: struct cpufreq_policy into which the current cpufreq_policy
+ * is written
*
* Reads the current cpufreq policy.
*/
if (!cpu_policy)
return -EINVAL;
- down(&cpu_policy->lock);
memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy));
- up(&cpu_policy->lock);
cpufreq_cpu_put(cpu_policy);
-
return 0;
}
EXPORT_SYMBOL(cpufreq_get_policy);
-static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy)
+/*
+ * data : current policy.
+ * policy : policy to be set.
+ */
+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->max || policy->max < data->min) {
+ ret = -EINVAL;
+ goto error_out;
+ }
/* verify the cpu speed can be set within this limit */
ret = cpufreq_driver->verify(policy);
if (ret)
goto error_out;
- down_read(&cpufreq_notifier_rwsem);
-
/* adjust if necessary - all reasons */
- notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_ADJUST,
- policy);
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_ADJUST, policy);
/* adjust if necessary - hardware incompatibility*/
- notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_INCOMPATIBLE,
- policy);
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_INCOMPATIBLE, policy);
/* verify the cpu speed can be set within this limit,
which might be different to the first one */
ret = cpufreq_driver->verify(policy);
- if (ret) {
- up_read(&cpufreq_notifier_rwsem);
+ if (ret)
goto error_out;
- }
/* notification of the new policy */
- notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_NOTIFY,
- policy);
-
- up_read(&cpufreq_notifier_rwsem);
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_NOTIFY, policy);
- data->min = policy->min;
- data->max = policy->max;
+ 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_governor(data, CPUFREQ_GOV_LIMITS);
}
- error_out:
+error_out:
cpufreq_debug_enable_ratelimit();
return ret;
}
/**
- * 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 this CPU */
- down(&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;
-
- up(&data->lock);
- 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
*
{
struct cpufreq_policy *data = cpufreq_cpu_get(cpu);
struct cpufreq_policy policy;
- int ret = 0;
+ int ret;
- if (!data)
- return -ENODEV;
+ if (!data) {
+ ret = -ENODEV;
+ goto no_policy;
+ }
- down(&data->lock);
+ if (unlikely(lock_policy_rwsem_write(cpu))) {
+ ret = -EINVAL;
+ goto fail;
+ }
dprintk("updating policy for CPU %u\n", cpu);
- memcpy(&policy,
- data,
- sizeof(struct cpufreq_policy));
+ memcpy(&policy, data, sizeof(struct cpufreq_policy));
policy.min = data->user_policy.min;
policy.max = data->user_policy.max;
policy.policy = data->user_policy.policy;
policy.governor = data->user_policy.governor;
+ /* BIOS might change freq behind our back
+ -> ask driver for current freq and notify governors about a change */
+ if (cpufreq_driver->get) {
+ policy.cur = cpufreq_driver->get(cpu);
+ if (!data->cur) {
+ dprintk("Driver did not initialize current freq");
+ data->cur = policy.cur;
+ } else {
+ if (data->cur != policy.cur)
+ cpufreq_out_of_sync(cpu, data->cur,
+ policy.cur);
+ }
+ }
+
ret = __cpufreq_set_policy(data, &policy);
- up(&data->lock);
+ unlock_policy_rwsem_write(cpu);
+fail:
cpufreq_cpu_put(data);
+no_policy:
return ret;
}
EXPORT_SYMBOL(cpufreq_update_policy);
+static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+ 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:
+ case CPU_DOWN_PREPARE_FROZEN:
+ if (unlikely(lock_policy_rwsem_write(cpu)))
+ BUG();
+
+ __cpufreq_remove_dev(sys_dev);
+ break;
+ case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
+ cpufreq_add_dev(sys_dev);
+ break;
+ }
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block __refdata cpufreq_cpu_notifier =
+{
+ .notifier_call = cpufreq_cpu_callback,
+};
/*********************************************************************
* REGISTER / UNREGISTER CPUFREQ DRIVER *
* @driver_data: A struct cpufreq_driver containing the values#
* submitted by the CPU Frequency driver.
*
- * Registers a CPU Frequency driver to this core code. This code
+ * Registers a CPU Frequency driver to this core code. This code
* returns zero on success, -EBUSY when another driver got here first
- * (and isn't unregistered in the meantime).
+ * (and isn't unregistered in the meantime).
*
*/
int cpufreq_register_driver(struct cpufreq_driver *driver_data)
cpufreq_driver = driver_data;
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
- ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver);
+ ret = sysdev_driver_register(&cpu_sysdev_class,
+ &cpufreq_sysdev_driver);
if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) {
int i;
ret = -ENODEV;
/* check for at least one working CPU */
- for (i=0; i<NR_CPUS; i++)
- if (cpufreq_cpu_data[i])
+ for (i = 0; i < nr_cpu_ids; i++)
+ if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) {
ret = 0;
+ break;
+ }
/* 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;
}
if (!ret) {
+ register_hotcpu_notifier(&cpufreq_cpu_notifier);
dprintk("driver %s up and running\n", driver_data->name);
cpufreq_debug_enable_ratelimit();
}
- return (ret);
+ return ret;
}
EXPORT_SYMBOL_GPL(cpufreq_register_driver);
/**
* cpufreq_unregister_driver - unregister the current CPUFreq driver
*
- * Unregister the current CPUFreq driver. Only call this if you have
+ * Unregister the current CPUFreq driver. Only call this if you have
* the right to do so, i.e. if you have succeeded in initialising before!
* Returns zero if successful, and -EINVAL if the cpufreq_driver is
* currently not initialised.
dprintk("unregistering driver %s\n", driver->name);
sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
+ unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
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