[PATCH] Notifier chain update: API changes
[linux-2.6-block.git] / drivers / cpufreq / cpufreq.c
index 9582de1c9cadc543517b1aff92d8a7910960a7eb..9b6ae7dc8b8a3a736666568fad41c3b8b567210d 100644 (file)
@@ -5,7 +5,9 @@
  *            (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
  *
  *  Oct 2005 - Ashok Raj <ashok.raj@intel.com>
- *                     Added handling for CPU hotplug
+ *     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
@@ -44,15 +46,14 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event)
 static void handle_update(void *data);
 
 /**
- * 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 BLOCKING_NOTIFIER_HEAD(cpufreq_transition_notifier_list);
 
 
 static LIST_HEAD(cpufreq_governor_list);
@@ -151,7 +152,7 @@ void cpufreq_debug_printk(unsigned int type, const char *prefix, const char *fmt
        va_list args;
        unsigned int len;
        unsigned long flags;
-       
+
        WARN_ON(!prefix);
        if (type & debug) {
                spin_lock_irqsave(&disable_ratelimit_lock, flags);
@@ -198,7 +199,7 @@ static inline void cpufreq_debug_disable_ratelimit(void) { return; }
  *
  * 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
@@ -233,7 +234,7 @@ static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) {
  *
  * This function calls the transition notifiers and the "adjust_jiffies"
  * function. It is called twice on all CPU frequency changes that have
- * external effects. 
+ * external effects.
  */
 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
 {
@@ -245,13 +246,11 @@ void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
        dprintk("notification %u of frequency transition to %u kHz\n",
                state, freqs->new);
 
-       down_read(&cpufreq_notifier_rwsem);
-
        policy = cpufreq_cpu_data[freqs->cpu];
        switch (state) {
 
        case CPUFREQ_PRECHANGE:
-               /* detect if the driver reported a value as "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".
                 */
@@ -264,20 +263,19 @@ void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
                                freqs->old = policy->cur;
                        }
                }
-               notifier_call_chain(&cpufreq_transition_notifier_list,
-                                       CPUFREQ_PRECHANGE, freqs);
+               blocking_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);
+               blocking_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);
 
@@ -335,11 +333,11 @@ extern struct sysdev_class cpu_sysdev_class;
  * "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);
@@ -404,8 +402,8 @@ static ssize_t show_scaling_governor (struct cpufreq_policy * policy, char *buf)
 /**
  * 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];
@@ -528,7 +526,7 @@ static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf)
        return ret;
 }
 
-static ssize_t store(struct kobject * kobj, struct attribute * attr, 
+static ssize_t store(struct kobject * kobj, struct attribute * attr,
                     const char * buf, size_t count)
 {
        struct cpufreq_policy * policy = to_policy(kobj);
@@ -564,7 +562,7 @@ static struct kobj_type ktype_cpufreq = {
 /**
  * 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)
 {
@@ -573,8 +571,12 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
        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;
@@ -587,8 +589,7 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
         * 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;
        }
@@ -623,6 +624,32 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
                goto err_out;
        }
 
+#ifdef CONFIG_SMP
+       for_each_cpu_mask(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);
+               if (unlikely(managed_policy)) {
+                       spin_lock_irqsave(&cpufreq_driver_lock, flags);
+                       managed_policy->cpus = policy->cpus;
+                       cpufreq_cpu_data[cpu] = managed_policy;
+                       spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+                       dprintk("CPU already managed, adding link\n");
+                       sysfs_create_link(&sys_dev->kobj,
+                                         &managed_policy->kobj, "cpufreq");
+
+                       cpufreq_debug_enable_ratelimit();
+                       mutex_unlock(&policy->lock);
+                       ret = 0;
+                       goto err_out_driver_exit; /* call driver->exit() */
+               }
+       }
+#endif
        memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));
 
        /* prepare interface data */
@@ -650,6 +677,21 @@ static int cpufreq_add_dev (struct sys_device * sys_dev)
        for_each_cpu_mask(j, policy->cpus)
                cpufreq_cpu_data[j] = policy;
        spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+       /* symlink affected CPUs */
+       for_each_cpu_mask(j, policy->cpus) {
+               if (j == cpu)
+                       continue;
+               if (!cpu_online(j))
+                       continue;
+
+               dprintk("CPU already managed, adding link\n");
+               cpufreq_cpu_get(cpu);
+               cpu_sys_dev = get_cpu_sysdev(j);
+               sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj,
+                                 "cpufreq");
+       }
+
        policy->governor = NULL; /* to assure that the starting sequence is
                                  * run in cpufreq_set_policy */
        mutex_unlock(&policy->lock);
@@ -724,10 +766,11 @@ static int cpufreq_remove_dev (struct sys_device * sys_dev)
 
 #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");
+               cpu_clear(cpu, data->cpus);
                spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
                sysfs_remove_link(&sys_dev->kobj, "cpufreq");
                cpufreq_cpu_put(data);
@@ -740,7 +783,7 @@ static int cpufreq_remove_dev (struct sys_device * sys_dev)
        if (!kobject_get(&data->kobj)) {
                spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
                cpufreq_debug_enable_ratelimit();
-               return -EFAULT;
+               return -EFAULT;
        }
 
 #ifdef CONFIG_SMP
@@ -783,7 +826,7 @@ static int cpufreq_remove_dev (struct sys_device * sys_dev)
        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");
@@ -831,7 +874,7 @@ 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
  * @cpu: CPU number
  *
@@ -855,7 +898,7 @@ unsigned int cpufreq_quick_get(unsigned int cpu)
 EXPORT_SYMBOL(cpufreq_quick_get);
 
 
-/** 
+/**
  * cpufreq_get - get the current CPU frequency (in kHz)
  * @cpu: CPU number
  *
@@ -960,7 +1003,7 @@ static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
                freqs.old = cpu_policy->cur;
                freqs.new = cur_freq;
 
-               notifier_call_chain(&cpufreq_transition_notifier_list,
+               blocking_notifier_call_chain(&cpufreq_transition_notifier_list,
                                    CPUFREQ_SUSPENDCHANGE, &freqs);
                adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs);
 
@@ -1041,7 +1084,8 @@ static int cpufreq_resume(struct sys_device * sysdev)
                        freqs.old = cpu_policy->cur;
                        freqs.new = cur_freq;
 
-                       notifier_call_chain(&cpufreq_transition_notifier_list,
+                       blocking_notifier_call_chain(
+                                       &cpufreq_transition_notifier_list,
                                        CPUFREQ_RESUMECHANGE, &freqs);
                        adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs);
 
@@ -1072,30 +1116,30 @@ static struct sysdev_driver cpufreq_sysdev_driver = {
  *     @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);
        switch (list) {
        case CPUFREQ_TRANSITION_NOTIFIER:
-               ret = notifier_chain_register(&cpufreq_transition_notifier_list, nb);
+               ret = blocking_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;
 }
@@ -1110,24 +1154,24 @@ EXPORT_SYMBOL(cpufreq_register_notifier);
  *     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 = blocking_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;
 }
@@ -1225,7 +1269,7 @@ int cpufreq_register_governor(struct cpufreq_governor *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);
@@ -1234,7 +1278,7 @@ int cpufreq_register_governor(struct cpufreq_governor *governor)
        }
        list_add(&governor->governor_list, &cpufreq_governor_list);
 
-       mutex_unlock(&cpufreq_governor_mutex);
+       mutex_unlock(&cpufreq_governor_mutex);
        return 0;
 }
 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
@@ -1299,29 +1343,23 @@ static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_poli
        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;
@@ -1497,9 +1535,9 @@ static struct notifier_block cpufreq_cpu_notifier =
  * @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)
@@ -1560,7 +1598,7 @@ 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.