[PATCH] knfsd: nfsd4: simplify nfsv4->posix translation
[safe/jmp/linux-2.6] / drivers / cpufreq / cpufreq.c
index 29b2fa5..a45cc89 100644 (file)
@@ -15,7 +15,6 @@
  *
  */
 
-#include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.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.
  */
@@ -43,7 +43,7 @@ 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 void handle_update(struct work_struct *work);
 
 /**
  * Two notifier lists: the "policy" list is involved in the
@@ -53,8 +53,14 @@ static void handle_update(void *data);
  * 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);
@@ -146,7 +152,8 @@ static void cpufreq_debug_disable_ratelimit(void)
        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;
@@ -156,7 +163,8 @@ void cpufreq_debug_printk(unsigned int type, const char *prefix, const char *fmt
        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;
                }
@@ -177,10 +185,12 @@ 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_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 */
 
@@ -214,17 +224,23 @@ static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
        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
 
 
@@ -257,20 +273,20 @@ void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
                if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
                        if ((policy) && (policy->cpu == freqs->cpu) &&
                            (policy->cur) && (policy->cur != freqs->old)) {
-                               dprintk(KERN_WARNING "Warning: CPU frequency is"
+                               dprintk("Warning: CPU frequency is"
                                        " %u, cpufreq assumed %u kHz.\n",
                                        freqs->old, policy->cur);
                                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;
@@ -285,39 +301,71 @@ 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,
                                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;
+
                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;
+
+               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);
-                               return 0;
+                               ret = request_module(name);
+                               mutex_lock(&cpufreq_governor_mutex);
+
+                               if (ret == 0)
+                                       t = __find_governor(str_governor);
                        }
+
+                       kfree(name);
                }
-out:
+
+               if (t != NULL) {
+                       *governor = t;
+                       err = 0;
+               }
+
                mutex_unlock(&cpufreq_governor_mutex);
        }
-       return -EINVAL;
+  out:
+       return err;
 }
 
 
@@ -326,7 +374,8 @@ extern struct sysdev_class cpu_sysdev_class;
 
 
 /**
- * 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".
@@ -345,7 +394,8 @@ 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);
+static int __cpufreq_set_policy(struct cpufreq_policy *data,
+                               struct cpufreq_policy *policy);
 
 /**
  * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
@@ -365,10 +415,12 @@ static ssize_t store_##file_name                                  \
        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;                                       \
 }
@@ -379,7 +431,8 @@ 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);
        if (!cur_freq)
@@ -391,7 +444,8 @@ static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, char *buf)
 /**
  * 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");
@@ -421,9 +475,12 @@ static ssize_t store_scaling_governor (struct cpufreq_policy * policy,
        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);
@@ -433,7 +490,12 @@ static ssize_t store_scaling_governor (struct cpufreq_policy * policy,
        policy->user_policy.governor = policy->governor;
        mutex_unlock(&policy->lock);
 
-       return ret ? ret : count;
+       unlock_cpu_hotplug();
+
+       if (ret)
+               return ret;
+       else
+               return count;
 }
 
 /**
@@ -447,7 +509,7 @@ static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf)
 /**
  * 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;
@@ -533,7 +595,11 @@ static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf)
        policy = cpufreq_cpu_get(policy->cpu);
        if (!policy)
                return -EINVAL;
-       ret = fattr->show ? fattr->show(policy,buf) : -EIO;
+       if (fattr->show)
+               ret = fattr->show(policy, buf);
+       else
+               ret = -EIO;
+
        cpufreq_cpu_put(policy);
        return ret;
 }
@@ -547,7 +613,11 @@ static ssize_t store(struct kobject * kobj, struct attribute * attr,
        policy = cpufreq_cpu_get(policy->cpu);
        if (!policy)
                return -EINVAL;
-       ret = fattr->store ? fattr->store(policy,buf,count) : -EIO;
+       if (fattr->store)
+               ret = fattr->store(policy, buf, count);
+       else
+               ret = -EIO;
+
        cpufreq_cpu_put(policy);
        return ret;
 }
@@ -624,7 +694,7 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
        mutex_init(&policy->lock);
        mutex_lock(&policy->lock);
        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
@@ -652,8 +722,13 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
                        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) {
+                               mutex_unlock(&policy->lock);
+                               goto err_out_driver_exit;
+                       }
 
                        cpufreq_debug_enable_ratelimit();
                        mutex_unlock(&policy->lock);
@@ -700,8 +775,12 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
                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) {
+                       mutex_unlock(&policy->lock);
+                       goto err_out_unregister;
+               }
        }
 
        policy->governor = NULL; /* to assure that the starting sequence is
@@ -854,9 +933,11 @@ static int cpufreq_remove_dev (struct sys_device * sys_dev)
 }
 
 
-static void handle_update(void *data)
+static void handle_update(struct work_struct *work)
 {
-       unsigned int cpu = (unsigned int)(long)data;
+       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);
 }
@@ -870,11 +951,12 @@ static void handle_update(void *data)
  *     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;
@@ -886,7 +968,7 @@ 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
+ * 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.
@@ -895,16 +977,16 @@ static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigne
 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;
+               ret_freq = policy->cur;
                mutex_unlock(&policy->lock);
                cpufreq_cpu_put(policy);
        }
 
-       return (ret);
+       return (ret_freq);
 }
 EXPORT_SYMBOL(cpufreq_quick_get);
 
@@ -918,7 +1000,7 @@ EXPORT_SYMBOL(cpufreq_quick_get);
 unsigned int cpufreq_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;
@@ -928,12 +1010,14 @@ unsigned int cpufreq_get(unsigned int cpu)
 
        mutex_lock(&policy->lock);
 
-       ret = cpufreq_driver->get(cpu);
+       ret_freq = cpufreq_driver->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);
+       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);
                }
        }
@@ -943,7 +1027,7 @@ unsigned int cpufreq_get(unsigned int cpu)
 out:
        cpufreq_cpu_put(policy);
 
-       return (ret);
+       return (ret_freq);
 }
 EXPORT_SYMBOL(cpufreq_get);
 
@@ -955,11 +1039,11 @@ 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;
@@ -1006,7 +1090,7 @@ static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
                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);
 
@@ -1014,7 +1098,7 @@ static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
                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);
 
@@ -1037,7 +1121,7 @@ out:
 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);
@@ -1087,7 +1171,7 @@ static int cpufreq_resume(struct sys_device * sysdev)
                        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);
 
@@ -1095,7 +1179,7 @@ static int cpufreq_resume(struct sys_device * sysdev)
                        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);
@@ -1141,7 +1225,7 @@ int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
 
        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:
@@ -1173,7 +1257,7 @@ int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
 
        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:
@@ -1194,20 +1278,18 @@ EXPORT_SYMBOL(cpufreq_unregister_notifier);
  *********************************************************************/
 
 
+/* Must be called with lock_cpu_hotplug held */
 int __cpufreq_driver_target(struct cpufreq_policy *policy,
                            unsigned int target_freq,
                            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);
@@ -1222,75 +1304,84 @@ int cpufreq_driver_target(struct cpufreq_policy *policy,
        if (!policy)
                return -EINVAL;
 
+       lock_cpu_hotplug();
        mutex_lock(&policy->lock);
 
        ret = __cpufreq_driver_target(policy, target_freq, relation);
 
        mutex_unlock(&policy->lock);
+       unlock_cpu_hotplug();
 
        cpufreq_cpu_put(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)
 {
-       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);
+       mutex_lock(&policy->lock);
 
-       /* 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(policy->cpu) && cpufreq_driver->getavg)
+               ret = cpufreq_driver->getavg(policy->cpu);
 
+       mutex_unlock(&policy->lock);
+
+       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
+ */
 
-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)
+       if (!try_module_get(policy->governor->owner))
                return -EINVAL;
 
-       mutex_lock(&policy->lock);
-       ret = __cpufreq_governor(policy, event);
-       mutex_unlock(&policy->lock);
+       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);
 
-       cpufreq_cpu_put(policy);
        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;
 
        mutex_lock(&cpufreq_governor_mutex);
 
-       list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
-               if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) {
-                       mutex_unlock(&cpufreq_governor_mutex);
-                       return -EBUSY;
-               }
+       err = -EBUSY;
+       if (__find_governor(governor->name) == NULL) {
+               err = 0;
+               list_add(&governor->governor_list, &cpufreq_governor_list);
        }
-       list_add(&governor->governor_list, &cpufreq_governor_list);
 
        mutex_unlock(&cpufreq_governor_mutex);
-       return 0;
+       return err;
 }
 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
 
@@ -1339,7 +1430,13 @@ int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
 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.
+ * Locking: Must be called with the lock_cpu_hotplug() lock held
+ */
+static int __cpufreq_set_policy(struct cpufreq_policy *data,
+                               struct cpufreq_policy *policy)
 {
        int ret = 0;
 
@@ -1347,7 +1444,13 @@ static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_poli
        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;
+               goto error_out;
+       }
 
        /* verify the cpu speed can be set within this limit */
        ret = cpufreq_driver->verify(policy);
@@ -1375,7 +1478,8 @@ static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_poli
        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;
@@ -1396,10 +1500,12 @@ static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_poli
                        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;
@@ -1433,6 +1539,8 @@ int cpufreq_set_policy(struct cpufreq_policy *policy)
        if (!data)
                return -EINVAL;
 
+       lock_cpu_hotplug();
+
        /* lock this CPU */
        mutex_lock(&data->lock);
 
@@ -1443,6 +1551,8 @@ int cpufreq_set_policy(struct cpufreq_policy *policy)
        data->user_policy.governor = data->governor;
 
        mutex_unlock(&data->lock);
+
+       unlock_cpu_hotplug();
        cpufreq_cpu_put(data);
 
        return ret;
@@ -1466,6 +1576,7 @@ int cpufreq_update_policy(unsigned int cpu)
        if (!data)
                return -ENODEV;
 
+       lock_cpu_hotplug();
        mutex_lock(&data->lock);
 
        dprintk("updating policy for CPU %u\n", cpu);
@@ -1484,14 +1595,15 @@ int cpufreq_update_policy(unsigned int cpu)
                        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();
        cpufreq_cpu_put(data);
        return ret;
 }
@@ -1532,7 +1644,7 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb,
        return NOTIFY_OK;
 }
 
-static struct notifier_block cpufreq_cpu_notifier =
+static struct notifier_block __cpuinitdata cpufreq_cpu_notifier =
 {
     .notifier_call = cpufreq_cpu_callback,
 };
@@ -1586,8 +1698,10 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
 
                /* 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;
@@ -1596,7 +1710,7 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data)
        }
 
        if (!ret) {
-               register_cpu_notifier(&cpufreq_cpu_notifier);
+               register_hotcpu_notifier(&cpufreq_cpu_notifier);
                dprintk("driver %s up and running\n", driver_data->name);
                cpufreq_debug_enable_ratelimit();
        }
@@ -1628,7 +1742,7 @@ int cpufreq_unregister_driver(struct cpufreq_driver *driver)
        dprintk("unregistering driver %s\n", driver->name);
 
        sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
-       unregister_cpu_notifier(&cpufreq_cpu_notifier);
+       unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
 
        spin_lock_irqsave(&cpufreq_driver_lock, flags);
        cpufreq_driver = NULL;