#include <linux/cpu.h>
#include <linux/completion.h>
+#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "cpufreq-core", msg)
+
/**
* The "cpufreq driver" - the arch- or hardware-dependend low
* level driver of CPUFreq support, and its spinlock. This lock
*/
static struct cpufreq_driver *cpufreq_driver;
static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS];
-static spinlock_t cpufreq_driver_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(cpufreq_driver_lock);
+
+
+/* we keep a copy of all ->add'ed CPU's struct sys_device here;
+ * as it is only accessed in ->add and ->remove, no lock or reference
+ * count is necessary.
+ */
+static struct sys_device *cpu_sys_devices[NR_CPUS];
+
/* internal prototypes */
static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event);
static LIST_HEAD(cpufreq_governor_list);
static DECLARE_MUTEX (cpufreq_governor_sem);
-static 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;
err_out:
return NULL;
}
+EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
-static void cpufreq_cpu_put(struct cpufreq_policy *data)
+void cpufreq_cpu_put(struct cpufreq_policy *data)
{
kobject_put(&data->kobj);
module_put(cpufreq_driver->owner);
}
+EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
+
+
+/*********************************************************************
+ * UNIFIED DEBUG HELPERS *
+ *********************************************************************/
+#ifdef CONFIG_CPU_FREQ_DEBUG
+
+/* what part(s) of the CPUfreq subsystem are debugged? */
+static unsigned int debug;
+
+/* is the debug output ratelimit'ed using printk_ratelimit? User can
+ * set or modify this value.
+ */
+static unsigned int debug_ratelimit = 1;
+
+/* is the printk_ratelimit'ing enabled? It's enabled after a successful
+ * loading of a cpufreq driver, temporarily disabled when a new policy
+ * is set, and disabled upon cpufreq driver removal
+ */
+static unsigned int disable_ratelimit = 1;
+static DEFINE_SPINLOCK(disable_ratelimit_lock);
+
+static inline void cpufreq_debug_enable_ratelimit(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&disable_ratelimit_lock, flags);
+ if (disable_ratelimit)
+ disable_ratelimit--;
+ spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
+}
+
+static inline void cpufreq_debug_disable_ratelimit(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&disable_ratelimit_lock, flags);
+ disable_ratelimit++;
+ spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
+}
+
+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()) {
+ spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
+ return;
+ }
+ spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
+
+ len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix);
+
+ va_start(args, fmt);
+ len += vsnprintf(&s[len], (256 - len), fmt, args);
+ va_end(args);
+
+ printk(s);
+
+ WARN_ON(len < 5);
+ }
+}
+EXPORT_SYMBOL(cpufreq_debug_printk);
+
+
+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_param(debug_ratelimit, uint, 0644);
+MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging: set to 0 to disable ratelimiting.");
+
+#else /* !CONFIG_CPU_FREQ_DEBUG */
+
+static inline void cpufreq_debug_enable_ratelimit(void) { return; }
+static inline void cpufreq_debug_disable_ratelimit(void) { return; }
+
+#endif /* CONFIG_CPU_FREQ_DEBUG */
+
/*********************************************************************
* EXTERNALLY AFFECTING FREQUENCY CHANGES *
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);
}
if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) ||
(val == CPUFREQ_POSTCHANGE && ci->old > ci->new) ||
- (val == CPUFREQ_RESUMECHANGE))
+ (val == CPUFREQ_RESUMECHANGE)) {
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; }
BUG_ON(irqs_disabled());
freqs->flags = cpufreq_driver->flags;
+ dprintk("notification %u of frequency transition to %u kHz\n", state, freqs->new);
down_read(&cpufreq_notifier_rwsem);
switch (state) {
*/
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)))
{
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]))
+ if ((likely(cpufreq_cpu_data[freqs->cpu])) &&
+ (likely(cpufreq_cpu_data[freqs->cpu]->cpu == freqs->cpu)))
cpufreq_cpu_data[freqs->cpu]->cur = freqs->new;
break;
}
/**
* cpufreq_parse_governor - parse a governor string
*/
-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)
{
if (!cpufreq_driver)
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)
+{
+ ssize_t i = 0;
+ unsigned int cpu;
+
+ for_each_cpu_mask(cpu, policy->cpus) {
+ 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;
+ }
+ i += sprintf(&buf[i], "\n");
+ return i;
+}
#define define_one_ro(_name) \
-struct freq_attr _name = { \
- .attr = { .name = __stringify(_name), .mode = 0444 }, \
- .show = show_##_name, \
-}
+static struct freq_attr _name = \
+__ATTR(_name, 0444, show_##_name, NULL)
#define define_one_ro0400(_name) \
-struct freq_attr _name = { \
- .attr = { .name = __stringify(_name), .mode = 0400 }, \
- .show = show_##_name, \
-}
+static struct freq_attr _name = \
+__ATTR(_name, 0400, show_##_name, NULL)
#define define_one_rw(_name) \
-struct freq_attr _name = { \
- .attr = { .name = __stringify(_name), .mode = 0644 }, \
- .show = show_##_name, \
- .store = store_##_name, \
-}
+static struct freq_attr _name = \
+__ATTR(_name, 0644, show_##_name, store_##_name)
define_one_ro0400(cpuinfo_cur_freq);
define_one_ro(cpuinfo_min_freq);
define_one_ro(scaling_available_governors);
define_one_ro(scaling_driver);
define_one_ro(scaling_cur_freq);
+define_one_ro(affected_cpus);
define_one_rw(scaling_min_freq);
define_one_rw(scaling_max_freq);
define_one_rw(scaling_governor);
&cpuinfo_max_freq.attr,
&scaling_min_freq.attr,
&scaling_max_freq.attr,
+ &affected_cpus.attr,
&scaling_governor.attr,
&scaling_driver.attr,
&scaling_available_governors.attr,
static void cpufreq_sysfs_release(struct kobject * kobj)
{
struct cpufreq_policy * policy = to_policy(kobj);
+ dprintk("last reference is dropped\n");
complete(&policy->kobj_unregister);
}
struct cpufreq_policy *policy;
struct freq_attr **drv_attr;
unsigned long flags;
+ unsigned int j;
+
+ cpufreq_debug_disable_ratelimit();
+ dprintk("adding CPU %u\n", cpu);
+
+#ifdef CONFIG_SMP
+ /* check whether a different CPU already registered this
+ * CPU because it is in the same boat. */
+ policy = cpufreq_cpu_get(cpu);
+ if (unlikely(policy)) {
+ cpu_sys_devices[cpu] = sys_dev;
+ dprintk("CPU already managed, adding link\n");
+ sysfs_create_link(&sys_dev->kobj, &policy->kobj, "cpufreq");
+ cpufreq_debug_enable_ratelimit();
+ return 0;
+ }
+#endif
- if (!try_module_get(cpufreq_driver->owner))
- return -EINVAL;
+ if (!try_module_get(cpufreq_driver->owner)) {
+ ret = -EINVAL;
+ goto module_out;
+ }
policy = kmalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
if (!policy) {
memset(policy, 0, sizeof(struct cpufreq_policy));
policy->cpu = cpu;
+ policy->cpus = cpumask_of_cpu(cpu);
+
init_MUTEX_LOCKED(&policy->lock);
init_completion(&policy->kobj_unregister);
INIT_WORK(&policy->update, handle_update, (void *)(long)cpu);
* to accept all calls to ->verify and ->setpolicy for this CPU
*/
ret = cpufreq_driver->init(policy);
- if (ret)
+ if (ret) {
+ dprintk("initialization failed\n");
goto err_out;
+ }
memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));
sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
spin_lock_irqsave(&cpufreq_driver_lock, flags);
- cpufreq_cpu_data[cpu] = policy;
+ for_each_cpu_mask(j, policy->cpus)
+ cpufreq_cpu_data[j] = policy;
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
policy->governor = NULL; /* to assure that the starting sequence is
* run in cpufreq_set_policy */
/* set default policy */
ret = cpufreq_set_policy(&new_policy);
- if (ret)
+ if (ret) {
+ dprintk("setting policy failed\n");
goto err_out_unregister;
+ }
module_put(cpufreq_driver->owner);
+ cpu_sys_devices[cpu] = sys_dev;
+ dprintk("initialization complete\n");
+ cpufreq_debug_enable_ratelimit();
+
return 0;
err_out_unregister:
spin_lock_irqsave(&cpufreq_driver_lock, flags);
- cpufreq_cpu_data[cpu] = NULL;
+ for_each_cpu_mask(j, policy->cpus)
+ cpufreq_cpu_data[j] = NULL;
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
kobject_unregister(&policy->kobj);
nomem_out:
module_put(cpufreq_driver->owner);
+ module_out:
+ cpufreq_debug_enable_ratelimit();
return ret;
}
unsigned int cpu = sys_dev->id;
unsigned long flags;
struct cpufreq_policy *data;
+#ifdef CONFIG_SMP
+ unsigned int j;
+#endif
+
+ cpufreq_debug_disable_ratelimit();
+ dprintk("unregistering CPU %u\n", cpu);
spin_lock_irqsave(&cpufreq_driver_lock, flags);
data = cpufreq_cpu_data[cpu];
if (!data) {
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ cpu_sys_devices[cpu] = NULL;
+ cpufreq_debug_enable_ratelimit();
return -EINVAL;
}
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
+ */
+ if (unlikely(cpu != data->cpu)) {
+ dprintk("removing link\n");
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ sysfs_remove_link(&sys_dev->kobj, "cpufreq");
+ cpu_sys_devices[cpu] = NULL;
+ cpufreq_cpu_put(data);
+ cpufreq_debug_enable_ratelimit();
+ return 0;
+ }
+#endif
+
+ cpu_sys_devices[cpu] = NULL;
+
+ if (!kobject_get(&data->kobj)) {
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ cpufreq_debug_enable_ratelimit();
+ return -EFAULT;
+ }
+
+#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.
+ */
+ if (unlikely(cpus_weight(data->cpus) > 1)) {
+ for_each_cpu_mask(j, data->cpus) {
+ if (j == cpu)
+ continue;
+ cpufreq_cpu_data[j] = NULL;
+ }
+ }
+
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
- if (!kobject_get(&data->kobj))
- return -EFAULT;
+ if (unlikely(cpus_weight(data->cpus) > 1)) {
+ for_each_cpu_mask(j, data->cpus) {
+ if (j == cpu)
+ continue;
+ dprintk("removing link for cpu %u\n", j);
+ sysfs_remove_link(&cpu_sys_devices[j]->kobj, "cpufreq");
+ cpufreq_cpu_put(data);
+ }
+ }
+#else
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+#endif
+ down(&data->lock);
if (cpufreq_driver->target)
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
+ cpufreq_driver->target = NULL;
+ up(&data->lock);
kobject_unregister(&data->kobj);
* not referenced anymore by anybody before we proceed with
* unloading.
*/
+ dprintk("waiting for dropping of refcount\n");
wait_for_completion(&data->kobj_unregister);
+ dprintk("wait complete\n");
if (cpufreq_driver->exit)
cpufreq_driver->exit(data);
kfree(data);
+ cpufreq_debug_enable_ratelimit();
+
return 0;
}
static void handle_update(void *data)
{
unsigned int cpu = (unsigned int)(long)data;
+ dprintk("handle_update for cpu %u called\n", cpu);
cpufreq_update_policy(cpu);
}
unsigned int ret = 0;
struct cpufreq_policy *cpu_policy;
+ dprintk("resuming cpu %u\n", cpu);
+
if (!cpu_online(cpu))
return 0;
if (!cpu_policy)
return -EINVAL;
+ /* only handle each CPU group once */
+ if (unlikely(cpu_policy->cpu != cpu)) {
+ cpufreq_cpu_put(cpu_policy);
+ return 0;
+ }
+
+ 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;
+ }
+ }
+
if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
unsigned int cur_freq = 0;
{
int retval = -EINVAL;
lock_cpu_hotplug();
- if (cpu_online(policy->cpu))
+ 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;
if (!try_module_get(policy->governor->owner))
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 */
{
int ret = 0;
+ cpufreq_debug_disable_ratelimit();
+ 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));
data->min = policy->min;
data->max = policy->max;
+ dprintk("new min and max freqs are %u - %u kHz\n", data->min, data->max);
+
if (cpufreq_driver->setpolicy) {
data->policy = policy->policy;
+ dprintk("setting range\n");
ret = cpufreq_driver->setpolicy(policy);
} else {
if (policy->governor != data->governor) {
/* save old, working values */
struct cpufreq_governor *old_gov = data->governor;
+ dprintk("governor switch\n");
+
/* end old governor */
if (data->governor)
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
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);
if (old_gov) {
data->governor = old_gov;
__cpufreq_governor(data, CPUFREQ_GOV_START);
}
/* might be a policy change, too, so fall through */
}
+ dprintk("governor: change or update limits\n");
__cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
}
error_out:
+ cpufreq_debug_enable_ratelimit();
return ret;
}
down(&data->lock);
+ dprintk("updating policy for CPU %u\n", cpu);
memcpy(&policy,
data,
sizeof(struct cpufreq_policy));
((!driver_data->setpolicy) && (!driver_data->target)))
return -EINVAL;
+ dprintk("trying to register driver %s\n", driver_data->name);
+
if (driver_data->setpolicy)
driver_data->flags |= CPUFREQ_CONST_LOOPS;
/* 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);
spin_lock_irqsave(&cpufreq_driver_lock, flags);
}
}
+ if (!ret) {
+ dprintk("driver %s up and running\n", driver_data->name);
+ cpufreq_debug_enable_ratelimit();
+ }
+
return (ret);
}
EXPORT_SYMBOL_GPL(cpufreq_register_driver);
{
unsigned long flags;
- if (!cpufreq_driver || (driver != cpufreq_driver))
+ cpufreq_debug_disable_ratelimit();
+
+ if (!cpufreq_driver || (driver != cpufreq_driver)) {
+ cpufreq_debug_enable_ratelimit();
return -EINVAL;
+ }
+
+ dprintk("unregistering driver %s\n", driver->name);
sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
git://git.onelab.eu / linux-2.6.git / blobdiff