percpu_ref: rename things to prepare for decoupling percpu/atomic mode switch

[deliverable/linux.git] / include / linux / percpu-refcount.h

diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h
index 3d463a39e0f7d39448fa0b7dbbf3bed6f738e68e..910e5f72055dd3595c12af7c9ab3a56c2381dd5b 100644 (file)
--- a/include/linux/percpu-refcount.h
+++ b/include/linux/percpu-refcount.h
@@ -54,6 +54,11 @@
 struct percpu_ref;
 typedef void (percpu_ref_func_t)(struct percpu_ref *);
 
+/* flags set in the lower bits of percpu_ref->percpu_count_ptr */
+enum {
+       __PERCPU_REF_ATOMIC     = 1LU << 0,     /* operating in atomic mode */
+};
+
 struct percpu_ref {
        atomic_long_t           count;
        /*
@@ -62,7 +67,7 @@ struct percpu_ref {
         */
        unsigned long           percpu_count_ptr;
        percpu_ref_func_t       *release;
-       percpu_ref_func_t       *confirm_kill;
+       percpu_ref_func_t       *confirm_switch;
        struct rcu_head         rcu;
 };
 
@@ -88,23 +93,21 @@ static inline void percpu_ref_kill(struct percpu_ref *ref)
        return percpu_ref_kill_and_confirm(ref, NULL);
 }
 
-#define __PERCPU_REF_DEAD      1
-
 /*
  * Internal helper.  Don't use outside percpu-refcount proper.  The
  * function doesn't return the pointer and let the caller test it for NULL
  * because doing so forces the compiler to generate two conditional
  * branches as it can't assume that @ref->percpu_count is not NULL.
  */
-static inline bool __percpu_ref_alive(struct percpu_ref *ref,
-                                     unsigned long __percpu **percpu_countp)
+static inline bool __ref_is_percpu(struct percpu_ref *ref,
+                                         unsigned long __percpu **percpu_countp)
 {
        unsigned long percpu_ptr = ACCESS_ONCE(ref->percpu_count_ptr);
 
        /* paired with smp_store_release() in percpu_ref_reinit() */
        smp_read_barrier_depends();
 
-       if (unlikely(percpu_ptr & __PERCPU_REF_DEAD))
+       if (unlikely(percpu_ptr & __PERCPU_REF_ATOMIC))
                return false;
 
        *percpu_countp = (unsigned long __percpu *)percpu_ptr;
@@ -125,7 +128,7 @@ static inline void percpu_ref_get(struct percpu_ref *ref)
 
        rcu_read_lock_sched();
 
-       if (__percpu_ref_alive(ref, &percpu_count))
+       if (__ref_is_percpu(ref, &percpu_count))
                this_cpu_inc(*percpu_count);
        else
                atomic_long_inc(&ref->count);
@@ -149,7 +152,7 @@ static inline bool percpu_ref_tryget(struct percpu_ref *ref)
 
        rcu_read_lock_sched();
 
-       if (__percpu_ref_alive(ref, &percpu_count)) {
+       if (__ref_is_percpu(ref, &percpu_count)) {
                this_cpu_inc(*percpu_count);
                ret = true;
        } else {
@@ -183,7 +186,7 @@ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref)
 
        rcu_read_lock_sched();
 
-       if (__percpu_ref_alive(ref, &percpu_count)) {
+       if (__ref_is_percpu(ref, &percpu_count)) {
                this_cpu_inc(*percpu_count);
                ret = true;
        }
@@ -208,7 +211,7 @@ static inline void percpu_ref_put(struct percpu_ref *ref)
 
        rcu_read_lock_sched();
 
-       if (__percpu_ref_alive(ref, &percpu_count))
+       if (__ref_is_percpu(ref, &percpu_count))
                this_cpu_dec(*percpu_count);
        else if (unlikely(atomic_long_dec_and_test(&ref->count)))
                ref->release(ref);
@@ -228,7 +231,7 @@ static inline bool percpu_ref_is_zero(struct percpu_ref *ref)
 {
        unsigned long __percpu *percpu_count;
 
-       if (__percpu_ref_alive(ref, &percpu_count))
+       if (__ref_is_percpu(ref, &percpu_count))
                return false;
        return !atomic_long_read(&ref->count);
 }