kconfig: use pkg-config for ncurses detection
[akaros.git] / kern / lib / percpu_counter.c
index 3bf4a99..1626e38 100644 (file)
@@ -1,76 +1,25 @@
+/* Copyright (C) 1991-2017, the Linux Kernel authors */
+
 /*
  * Fast batching percpu counters.
  */
 
-#include <linux/percpu_counter.h>
-#include <linux/notifier.h>
-#include <linux/mutex.h>
-#include <linux/init.h>
-#include <linux/cpu.h>
-#include <linux/module.h>
-#include <linux/debugobjects.h>
-
-#ifdef CONFIG_HOTPLUG_CPU
-static LIST_HEAD(percpu_counters);
-static DEFINE_SPINLOCK(percpu_counters_lock);
-#endif
-
-#ifdef CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER
-
-static struct debug_obj_descr percpu_counter_debug_descr;
-
-static bool percpu_counter_fixup_free(void *addr, enum debug_obj_state state)
-{
-       struct percpu_counter *fbc = addr;
-
-       switch (state) {
-       case ODEBUG_STATE_ACTIVE:
-               percpu_counter_destroy(fbc);
-               debug_object_free(fbc, &percpu_counter_debug_descr);
-               return true;
-       default:
-               return false;
-       }
-}
-
-static struct debug_obj_descr percpu_counter_debug_descr = {
-       .name           = "percpu_counter",
-       .fixup_free     = percpu_counter_fixup_free,
-};
+#include <percpu_counter.h>
+#include <linux_compat.h>
 
-static inline void debug_percpu_counter_activate(struct percpu_counter *fbc)
-{
-       debug_object_init(fbc, &percpu_counter_debug_descr);
-       debug_object_activate(fbc, &percpu_counter_debug_descr);
-}
-
-static inline void debug_percpu_counter_deactivate(struct percpu_counter *fbc)
-{
-       debug_object_deactivate(fbc, &percpu_counter_debug_descr);
-       debug_object_free(fbc, &percpu_counter_debug_descr);
-}
-
-#else  /* CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER */
-static inline void debug_percpu_counter_activate(struct percpu_counter *fbc)
-{ }
-static inline void debug_percpu_counter_deactivate(struct percpu_counter *fbc)
-{ }
-#endif /* CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER */
-
-void percpu_counter_set(struct percpu_counter *fbc, s64 amount)
+void percpu_counter_set(struct percpu_counter *fbc, int64_t amount)
 {
        int cpu;
        unsigned long flags;
 
-       raw_spin_lock_irqsave(&fbc->lock, flags);
+       spin_lock_irqsave(&fbc->lock);
        for_each_possible_cpu(cpu) {
-               s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
+               int32_t *pcount = _PERCPU_VARPTR(*fbc->counters, cpu);
                *pcount = 0;
        }
        fbc->count = amount;
-       raw_spin_unlock_irqrestore(&fbc->lock, flags);
+       spin_unlock_irqsave(&fbc->lock);
 }
-EXPORT_SYMBOL(percpu_counter_set);
 
 /**
  * This function is both preempt and irq safe. The former is due to explicit
@@ -79,69 +28,56 @@ EXPORT_SYMBOL(percpu_counter_set);
  * this_cpu_add which is irq-safe by definition. Hence there is no need muck
  * with irq state before calling this one
  */
-void percpu_counter_add_batch(struct percpu_counter *fbc, s64 amount, s32 batch)
+void percpu_counter_add_batch(struct percpu_counter *fbc, int64_t amount,
+                             int32_t batch)
 {
-       s64 count;
+       int64_t count;
 
        preempt_disable();
        count = __this_cpu_read(*fbc->counters) + amount;
        if (count >= batch || count <= -batch) {
                unsigned long flags;
-               raw_spin_lock_irqsave(&fbc->lock, flags);
+               spin_lock_irqsave(&fbc->lock);
                fbc->count += count;
                __this_cpu_sub(*fbc->counters, count - amount);
-               raw_spin_unlock_irqrestore(&fbc->lock, flags);
+               spin_unlock_irqsave(&fbc->lock);
        } else {
                this_cpu_add(*fbc->counters, amount);
        }
        preempt_enable();
 }
-EXPORT_SYMBOL(percpu_counter_add_batch);
 
 /*
  * 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)
+int64_t __percpu_counter_sum(struct percpu_counter *fbc)
 {
-       s64 ret;
+       int64_t ret;
        int cpu;
        unsigned long flags;
 
-       raw_spin_lock_irqsave(&fbc->lock, flags);
+       spin_lock_irqsave(&fbc->lock);
        ret = fbc->count;
        for_each_online_cpu(cpu) {
-               s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
+               int32_t *pcount = _PERCPU_VARPTR(*fbc->counters, cpu);
                ret += *pcount;
        }
-       raw_spin_unlock_irqrestore(&fbc->lock, flags);
+       spin_unlock_irqsave(&fbc->lock);
        return ret;
 }
-EXPORT_SYMBOL(__percpu_counter_sum);
 
-int __percpu_counter_init(struct percpu_counter *fbc, s64 amount, gfp_t gfp,
-                         struct lock_class_key *key)
+int percpu_counter_init(struct percpu_counter *fbc, int64_t amount, gfp_t gfp)
 {
        unsigned long flags __maybe_unused;
 
-       raw_spin_lock_init(&fbc->lock);
-       lockdep_set_class(&fbc->lock, key);
+       spinlock_init_irqsave(&fbc->lock);
        fbc->count = amount;
-       fbc->counters = alloc_percpu_gfp(s32, gfp);
+       fbc->counters = alloc_percpu_gfp(int32_t, gfp);
        if (!fbc->counters)
                return -ENOMEM;
-
-       debug_percpu_counter_activate(fbc);
-
-#ifdef CONFIG_HOTPLUG_CPU
-       INIT_LIST_HEAD(&fbc->list);
-       spin_lock_irqsave(&percpu_counters_lock, flags);
-       list_add(&fbc->list, &percpu_counters);
-       spin_unlock_irqrestore(&percpu_counters_lock, flags);
-#endif
        return 0;
 }
-EXPORT_SYMBOL(__percpu_counter_init);
 
 void percpu_counter_destroy(struct percpu_counter *fbc)
 {
@@ -149,59 +85,20 @@ void percpu_counter_destroy(struct percpu_counter *fbc)
 
        if (!fbc->counters)
                return;
-
-       debug_percpu_counter_deactivate(fbc);
-
-#ifdef CONFIG_HOTPLUG_CPU
-       spin_lock_irqsave(&percpu_counters_lock, flags);
-       list_del(&fbc->list);
-       spin_unlock_irqrestore(&percpu_counters_lock, flags);
-#endif
        free_percpu(fbc->counters);
        fbc->counters = NULL;
 }
-EXPORT_SYMBOL(percpu_counter_destroy);
 
 int percpu_counter_batch __read_mostly = 32;
-EXPORT_SYMBOL(percpu_counter_batch);
-
-static int compute_batch_value(unsigned int cpu)
-{
-       int nr = num_online_cpus();
-
-       percpu_counter_batch = max(32, nr*2);
-       return 0;
-}
-
-static int percpu_counter_cpu_dead(unsigned int cpu)
-{
-#ifdef CONFIG_HOTPLUG_CPU
-       struct percpu_counter *fbc;
-
-       compute_batch_value(cpu);
-
-       spin_lock_irq(&percpu_counters_lock);
-       list_for_each_entry(fbc, &percpu_counters, list) {
-               s32 *pcount;
-
-               raw_spin_lock(&fbc->lock);
-               pcount = per_cpu_ptr(fbc->counters, cpu);
-               fbc->count += *pcount;
-               *pcount = 0;
-               raw_spin_unlock(&fbc->lock);
-       }
-       spin_unlock_irq(&percpu_counters_lock);
-#endif
-       return 0;
-}
 
 /*
  * Compare counter against given value.
  * Return 1 if greater, 0 if equal and -1 if less
  */
-int __percpu_counter_compare(struct percpu_counter *fbc, s64 rhs, s32 batch)
+int __percpu_counter_compare(struct percpu_counter *fbc, int64_t rhs,
+                            int32_t batch)
 {
-       s64     count;
+       int64_t count;
 
        count = percpu_counter_read(fbc);
        /* Check to see if rough count will be sufficient for comparison */
@@ -220,19 +117,3 @@ int __percpu_counter_compare(struct percpu_counter *fbc, s64 rhs, s32 batch)
        else
                return 0;
 }
-EXPORT_SYMBOL(__percpu_counter_compare);
-
-static int __init percpu_counter_startup(void)
-{
-       int ret;
-
-       ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "lib/percpu_cnt:online",
-                               compute_batch_value, NULL);
-       WARN_ON(ret < 0);
-       ret = cpuhp_setup_state_nocalls(CPUHP_PERCPU_CNT_DEAD,
-                                       "lib/percpu_cnt:dead", NULL,
-                                       percpu_counter_cpu_dead);
-       WARN_ON(ret < 0);
-       return 0;
-}
-module_init(percpu_counter_startup);