42 static unsigned long __percpu *percpu_count_ptr(struct percpu_ref *ref)  in percpu_count_ptr()  argument
45 		(ref->percpu_count_ptr & ~__PERCPU_REF_ATOMIC_DEAD);  in percpu_count_ptr()
63 int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release,  in percpu_ref_init()  argument
71 	ref->percpu_count_ptr = (unsigned long)  in percpu_ref_init()
73 	if (!ref->percpu_count_ptr)  in percpu_ref_init()
76 	data = kzalloc(sizeof(*ref->data), gfp);  in percpu_ref_init()
78 		free_percpu((void __percpu *)ref->percpu_count_ptr);  in percpu_ref_init()
79 		ref->percpu_count_ptr = 0;  in percpu_ref_init()
87 		ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;  in percpu_ref_init()
94 		ref->percpu_count_ptr |= __PERCPU_REF_DEAD;  in percpu_ref_init()
102 	data->ref = ref;  in percpu_ref_init()
103 	ref->data = data;  in percpu_ref_init()
108 static void __percpu_ref_exit(struct percpu_ref *ref)  in __percpu_ref_exit()  argument
110 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in __percpu_ref_exit()
114 		WARN_ON_ONCE(ref->data && ref->data->confirm_switch);  in __percpu_ref_exit()
116 		ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD;  in __percpu_ref_exit()
130 void percpu_ref_exit(struct percpu_ref *ref)  in percpu_ref_exit()  argument
132 	struct percpu_ref_data *data = ref->data;  in percpu_ref_exit()
135 	__percpu_ref_exit(ref);  in percpu_ref_exit()
141 	ref->percpu_count_ptr |= atomic_long_read(&ref->data->count) <<  in percpu_ref_exit()
143 	ref->data = NULL;  in percpu_ref_exit()
154 	struct percpu_ref *ref = data->ref;  in percpu_ref_call_confirm_rcu()  local
156 	data->confirm_switch(ref);  in percpu_ref_call_confirm_rcu()
161 		__percpu_ref_exit(ref);  in percpu_ref_call_confirm_rcu()
164 	percpu_ref_put(ref);  in percpu_ref_call_confirm_rcu()
171 	struct percpu_ref *ref = data->ref;  in percpu_ref_switch_to_atomic_rcu()  local
172 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in percpu_ref_switch_to_atomic_rcu()
209 static void percpu_ref_noop_confirm_switch(struct percpu_ref *ref)  in percpu_ref_noop_confirm_switch()  argument
213 static void __percpu_ref_switch_to_atomic(struct percpu_ref *ref,  in __percpu_ref_switch_to_atomic()  argument
216 	if (ref->percpu_count_ptr & __PERCPU_REF_ATOMIC) {  in __percpu_ref_switch_to_atomic()
218 			confirm_switch(ref);  in __percpu_ref_switch_to_atomic()
223 	ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;  in __percpu_ref_switch_to_atomic()
229 	ref->data->confirm_switch = confirm_switch ?:  in __percpu_ref_switch_to_atomic()
232 	percpu_ref_get(ref);	/* put after confirmation */  in __percpu_ref_switch_to_atomic()
233 	call_rcu(&ref->data->rcu, percpu_ref_switch_to_atomic_rcu);  in __percpu_ref_switch_to_atomic()
236 static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)  in __percpu_ref_switch_to_percpu()  argument
238 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in __percpu_ref_switch_to_percpu()
243 	if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC))  in __percpu_ref_switch_to_percpu()
246 	if (WARN_ON_ONCE(!ref->data->allow_reinit))  in __percpu_ref_switch_to_percpu()
249 	atomic_long_add(PERCPU_COUNT_BIAS, &ref->data->count);  in __percpu_ref_switch_to_percpu()
260 	smp_store_release(&ref->percpu_count_ptr,  in __percpu_ref_switch_to_percpu()
261 			  ref->percpu_count_ptr & ~__PERCPU_REF_ATOMIC);  in __percpu_ref_switch_to_percpu()
264 static void __percpu_ref_switch_mode(struct percpu_ref *ref,  in __percpu_ref_switch_mode()  argument
267 	struct percpu_ref_data *data = ref->data;  in __percpu_ref_switch_mode()
279 	if (data->force_atomic || percpu_ref_is_dying(ref))  in __percpu_ref_switch_mode()
280 		__percpu_ref_switch_to_atomic(ref, confirm_switch);  in __percpu_ref_switch_mode()
282 		__percpu_ref_switch_to_percpu(ref);  in __percpu_ref_switch_mode()
305 void percpu_ref_switch_to_atomic(struct percpu_ref *ref,  in percpu_ref_switch_to_atomic()  argument
312 	ref->data->force_atomic = true;  in percpu_ref_switch_to_atomic()
313 	__percpu_ref_switch_mode(ref, confirm_switch);  in percpu_ref_switch_to_atomic()
327 void percpu_ref_switch_to_atomic_sync(struct percpu_ref *ref)  in percpu_ref_switch_to_atomic_sync()  argument
329 	percpu_ref_switch_to_atomic(ref, NULL);  in percpu_ref_switch_to_atomic_sync()
330 	wait_event(percpu_ref_switch_waitq, !ref->data->confirm_switch);  in percpu_ref_switch_to_atomic_sync()
352 void percpu_ref_switch_to_percpu(struct percpu_ref *ref)  in percpu_ref_switch_to_percpu()  argument
358 	ref->data->force_atomic = false;  in percpu_ref_switch_to_percpu()
359 	__percpu_ref_switch_mode(ref, NULL);  in percpu_ref_switch_to_percpu()
382 void percpu_ref_kill_and_confirm(struct percpu_ref *ref,  in percpu_ref_kill_and_confirm()  argument
389 	WARN_ONCE(percpu_ref_is_dying(ref),  in percpu_ref_kill_and_confirm()
391 		  ref->data->release);  in percpu_ref_kill_and_confirm()
393 	ref->percpu_count_ptr |= __PERCPU_REF_DEAD;  in percpu_ref_kill_and_confirm()
394 	__percpu_ref_switch_mode(ref, confirm_kill);  in percpu_ref_kill_and_confirm()
395 	percpu_ref_put(ref);  in percpu_ref_kill_and_confirm()
409 bool percpu_ref_is_zero(struct percpu_ref *ref)  in percpu_ref_is_zero()  argument
414 	if (__ref_is_percpu(ref, &percpu_count))  in percpu_ref_is_zero()
419 	if (ref->data)  in percpu_ref_is_zero()
420 		count = atomic_long_read(&ref->data->count);  in percpu_ref_is_zero()
422 		count = ref->percpu_count_ptr >> __PERCPU_REF_FLAG_BITS;  in percpu_ref_is_zero()
440 void percpu_ref_reinit(struct percpu_ref *ref)  in percpu_ref_reinit()  argument
442 	WARN_ON_ONCE(!percpu_ref_is_zero(ref));  in percpu_ref_reinit()
444 	percpu_ref_resurrect(ref);  in percpu_ref_reinit()
462 void percpu_ref_resurrect(struct percpu_ref *ref)  in percpu_ref_resurrect()  argument
469 	WARN_ON_ONCE(!percpu_ref_is_dying(ref));  in percpu_ref_resurrect()
470 	WARN_ON_ONCE(__ref_is_percpu(ref, &percpu_count));  in percpu_ref_resurrect()
472 	ref->percpu_count_ptr &= ~__PERCPU_REF_DEAD;  in percpu_ref_resurrect()
473 	percpu_ref_get(ref);  in percpu_ref_resurrect()
474 	__percpu_ref_switch_mode(ref, NULL);  in percpu_ref_resurrect()