Kobject: rename kobject_add_ng() to kobject_add()
[linux-3.10.git] / lib / percpu_counter.c
index 8901c4e..393a0e9 100644 (file)
@@ -14,15 +14,29 @@ static LIST_HEAD(percpu_counters);
 static DEFINE_MUTEX(percpu_counters_lock);
 #endif
 
-void percpu_counter_mod(struct percpu_counter *fbc, s32 amount)
+void percpu_counter_set(struct percpu_counter *fbc, s64 amount)
 {
-       long count;
+       int cpu;
+
+       spin_lock(&fbc->lock);
+       for_each_possible_cpu(cpu) {
+               s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
+               *pcount = 0;
+       }
+       fbc->count = amount;
+       spin_unlock(&fbc->lock);
+}
+EXPORT_SYMBOL(percpu_counter_set);
+
+void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch)
+{
+       s64 count;
        s32 *pcount;
        int cpu = get_cpu();
 
        pcount = per_cpu_ptr(fbc->counters, cpu);
        count = *pcount + amount;
-       if (count >= FBC_BATCH || count <= -FBC_BATCH) {
+       if (count >= batch || count <= -batch) {
                spin_lock(&fbc->lock);
                fbc->count += count;
                *pcount = 0;
@@ -32,43 +46,61 @@ void percpu_counter_mod(struct percpu_counter *fbc, s32 amount)
        }
        put_cpu();
 }
-EXPORT_SYMBOL(percpu_counter_mod);
+EXPORT_SYMBOL(__percpu_counter_add);
 
 /*
  * Add up all the per-cpu counts, return the result.  This is a more accurate
  * but much slower version of percpu_counter_read_positive()
  */
-s64 percpu_counter_sum(struct percpu_counter *fbc)
+s64 __percpu_counter_sum(struct percpu_counter *fbc)
 {
        s64 ret;
        int cpu;
 
        spin_lock(&fbc->lock);
        ret = fbc->count;
-       for_each_possible_cpu(cpu) {
+       for_each_online_cpu(cpu) {
                s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
                ret += *pcount;
        }
        spin_unlock(&fbc->lock);
-       return ret < 0 ? 0 : ret;
+       return ret;
 }
-EXPORT_SYMBOL(percpu_counter_sum);
+EXPORT_SYMBOL(__percpu_counter_sum);
+
+static struct lock_class_key percpu_counter_irqsafe;
 
-void percpu_counter_init(struct percpu_counter *fbc, s64 amount)
+int percpu_counter_init(struct percpu_counter *fbc, s64 amount)
 {
        spin_lock_init(&fbc->lock);
        fbc->count = amount;
        fbc->counters = alloc_percpu(s32);
+       if (!fbc->counters)
+               return -ENOMEM;
 #ifdef CONFIG_HOTPLUG_CPU
        mutex_lock(&percpu_counters_lock);
        list_add(&fbc->list, &percpu_counters);
        mutex_unlock(&percpu_counters_lock);
 #endif
+       return 0;
 }
 EXPORT_SYMBOL(percpu_counter_init);
 
+int percpu_counter_init_irq(struct percpu_counter *fbc, s64 amount)
+{
+       int err;
+
+       err = percpu_counter_init(fbc, amount);
+       if (!err)
+               lockdep_set_class(&fbc->lock, &percpu_counter_irqsafe);
+       return err;
+}
+
 void percpu_counter_destroy(struct percpu_counter *fbc)
 {
+       if (!fbc->counters)
+               return;
+
        free_percpu(fbc->counters);
 #ifdef CONFIG_HOTPLUG_CPU
        mutex_lock(&percpu_counters_lock);
@@ -92,12 +124,13 @@ static int __cpuinit percpu_counter_hotcpu_callback(struct notifier_block *nb,
        mutex_lock(&percpu_counters_lock);
        list_for_each_entry(fbc, &percpu_counters, list) {
                s32 *pcount;
+               unsigned long flags;
 
-               spin_lock(&fbc->lock);
+               spin_lock_irqsave(&fbc->lock, flags);
                pcount = per_cpu_ptr(fbc->counters, cpu);
                fbc->count += *pcount;
                *pcount = 0;
-               spin_unlock(&fbc->lock);
+               spin_unlock_irqrestore(&fbc->lock, flags);
        }
        mutex_unlock(&percpu_counters_lock);
        return NOTIFY_OK;