]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - drivers/cpufreq/cpufreq.c
[CPUFREQ] convert remaining cpufreq semaphore to a mutex
[karo-tx-linux.git] / drivers / cpufreq / cpufreq.c
index 25acf478c9e82c5f2d40cd6c89e9c8fcdb2862be..0675d9f02e345b462060b6cde651e6db1a0d4f4d 100644 (file)
@@ -26,6 +26,7 @@
 #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)
 
@@ -38,11 +39,9 @@ static struct cpufreq_driver         *cpufreq_driver;
 static struct cpufreq_policy   *cpufreq_cpu_data[NR_CPUS];
 static DEFINE_SPINLOCK(cpufreq_driver_lock);
 
-
 /* 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);
 
 /**
  * Two notifier lists: the "policy" list is involved in the 
@@ -57,7 +56,7 @@ static DECLARE_RWSEM          (cpufreq_notifier_rwsem);
 
 
 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)
 {
@@ -128,7 +127,7 @@ static unsigned int debug_ratelimit = 1;
 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;
 
@@ -138,7 +137,7 @@ static inline void cpufreq_debug_enable_ratelimit(void)
        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;
 
@@ -207,7 +206,7 @@ static inline void cpufreq_debug_disable_ratelimit(void) { return; }
 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;
@@ -299,18 +298,18 @@ static int cpufreq_parse_governor (char *str_governor, unsigned int *policy,
                return -EINVAL;
        } else {
                struct cpufreq_governor *t;
-               down(&cpufreq_governor_sem);
+               mutex_lock(&cpufreq_governor_mutex);
                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);
+                               mutex_unlock(&cpufreq_governor_mutex);
                                return 0;
                        }
                }
        out:
-               up(&cpufreq_governor_sem);
+               mutex_unlock(&cpufreq_governor_mutex);
        }
        return -EINVAL;
 }
@@ -602,7 +601,8 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
        policy->cpu = cpu;
        policy->cpus = cpumask_of_cpu(cpu);
 
-       init_MUTEX_LOCKED(&policy->lock);
+       mutex_init(&policy->lock);
+       mutex_lock(&policy->lock);
        init_completion(&policy->kobj_unregister);
        INIT_WORK(&policy->update, handle_update, (void *)(long)cpu);
 
@@ -643,7 +643,7 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
        spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
        policy->governor = NULL; /* to assure that the starting sequence is
                                  * run in cpufreq_set_policy */
-       up(&policy->lock);
+       mutex_unlock(&policy->lock);
        
        /* set default policy */
        
@@ -694,8 +694,8 @@ 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
 
@@ -764,10 +764,10 @@ static int cpufreq_remove_dev (struct sys_device * sys_dev)
        spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
 #endif
 
-       down(&data->lock);
+       mutex_lock(&data->lock);
        if (cpufreq_driver->target)
                __cpufreq_governor(data, CPUFREQ_GOV_STOP);
-       up(&data->lock);
+       mutex_unlock(&data->lock);
 
        kobject_unregister(&data->kobj);
 
@@ -823,6 +823,30 @@ static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigne
 }
 
 
+/** 
+ * cpufreq_quick_get - get the CPU frequency (in kHz) frpm policy->cur
+ * @cpu: CPU number
+ *
+ * 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_quick_get(unsigned int cpu)
+{
+       struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+       unsigned int ret = 0;
+
+       if (policy) {
+               mutex_lock(&policy->lock);
+               ret = policy->cur;
+               mutex_unlock(&policy->lock);
+               cpufreq_cpu_put(policy);
+       }
+
+       return (ret);
+}
+EXPORT_SYMBOL(cpufreq_quick_get);
+
+
 /** 
  * cpufreq_get - get the current CPU frequency (in kHz)
  * @cpu: CPU number
@@ -840,7 +864,7 @@ unsigned int cpufreq_get(unsigned int cpu)
        if (!cpufreq_driver->get)
                goto out;
 
-       down(&policy->lock);
+       mutex_lock(&policy->lock);
 
        ret = cpufreq_driver->get(cpu);
 
@@ -853,7 +877,7 @@ unsigned int cpufreq_get(unsigned int cpu)
                }
        }
 
-       up(&policy->lock);
+       mutex_unlock(&policy->lock);
 
  out:
        cpufreq_cpu_put(policy);
@@ -1114,25 +1138,14 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 {
        int retval = -EINVAL;
 
-       /*
-        * Converted the lock_cpu_hotplug to preempt_disable()
-        * and preempt_enable(). This is a bit kludgy and relies on how cpu
-        * hotplug works. All we need is a guarantee that cpu hotplug won't make
-        * progress on any cpu. Once we do preempt_disable(), this would ensure
-        * that hotplug threads don't get onto this cpu, thereby delaying
-        * the cpu remove process.
-        *
-        * We removed the lock_cpu_hotplug since we need to call this function
-        * via cpu hotplug callbacks, which result in locking the cpu hotplug
-        * thread itself. Agree this is not very clean, cpufreq community
-        * could improve this if required. - Ashok Raj <ashok.raj@intel.com>
-        */
-       preempt_disable();
+       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);
-       preempt_enable();
+
+       unlock_cpu_hotplug();
+
        return retval;
 }
 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
@@ -1147,11 +1160,11 @@ int cpufreq_driver_target(struct cpufreq_policy *policy,
        if (!policy)
                return -EINVAL;
 
-       down(&policy->lock);
+       mutex_lock(&policy->lock);
 
        ret = __cpufreq_driver_target(policy, target_freq, relation);
 
-       up(&policy->lock);
+       mutex_unlock(&policy->lock);
 
        cpufreq_cpu_put(policy);
 
@@ -1188,9 +1201,9 @@ int cpufreq_governor(unsigned int cpu, unsigned int event)
        if (!policy)
                return -EINVAL;
 
-       down(&policy->lock);
+       mutex_lock(&policy->lock);
        ret = __cpufreq_governor(policy, event);
-       up(&policy->lock);
+       mutex_unlock(&policy->lock);
 
        cpufreq_cpu_put(policy);
 
@@ -1206,17 +1219,17 @@ int cpufreq_register_governor(struct cpufreq_governor *governor)
        if (!governor)
                return -EINVAL;
 
-       down(&cpufreq_governor_sem);
+       mutex_lock(&cpufreq_governor_mutex);
        
        list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
                if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) {
-                       up(&cpufreq_governor_sem);
+                       mutex_unlock(&cpufreq_governor_mutex);
                        return -EBUSY;
                }
        }
        list_add(&governor->governor_list, &cpufreq_governor_list);
 
-       up(&cpufreq_governor_sem);
+       mutex_unlock(&cpufreq_governor_mutex);
 
        return 0;
 }
@@ -1228,9 +1241,9 @@ void cpufreq_unregister_governor(struct cpufreq_governor *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);
@@ -1257,9 +1270,9 @@ int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
        if (!cpu_policy)
                return -EINVAL;
 
-       down(&cpu_policy->lock);
+       mutex_lock(&cpu_policy->lock);
        memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy));
-       up(&cpu_policy->lock);
+       mutex_unlock(&cpu_policy->lock);
 
        cpufreq_cpu_put(cpu_policy);
 
@@ -1371,7 +1384,7 @@ int cpufreq_set_policy(struct cpufreq_policy *policy)
                return -EINVAL;
 
        /* lock this CPU */
-       down(&data->lock);
+       mutex_lock(&data->lock);
 
        ret = __cpufreq_set_policy(data, policy);
        data->user_policy.min = data->min;
@@ -1379,7 +1392,7 @@ int cpufreq_set_policy(struct cpufreq_policy *policy)
        data->user_policy.policy = data->policy;
        data->user_policy.governor = data->governor;
 
-       up(&data->lock);
+       mutex_unlock(&data->lock);
        cpufreq_cpu_put(data);
 
        return ret;
@@ -1403,7 +1416,7 @@ int cpufreq_update_policy(unsigned int cpu)
        if (!data)
                return -ENODEV;
 
-       down(&data->lock);
+       mutex_lock(&data->lock);
 
        dprintk("updating policy for CPU %u\n", cpu);
        memcpy(&policy, 
@@ -1416,7 +1429,7 @@ int cpufreq_update_policy(unsigned int cpu)
 
        ret = __cpufreq_set_policy(data, &policy);
 
-       up(&data->lock);
+       mutex_unlock(&data->lock);
 
        cpufreq_cpu_put(data);
        return ret;