41 static unsigned long __percpu *percpu_count_ptr(struct percpu_ref *ref)  in percpu_count_ptr()  argument
44 		(ref->percpu_count_ptr & ~__PERCPU_REF_ATOMIC_DEAD);  in percpu_count_ptr()
62 int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release,  in percpu_ref_init()  argument
70 	ref->percpu_count_ptr = (unsigned long)  in percpu_ref_init()
72 	if (!ref->percpu_count_ptr)  in percpu_ref_init()
75 	data = kzalloc(sizeof(*ref->data), gfp);  in percpu_ref_init()
77 		free_percpu((void __percpu *)ref->percpu_count_ptr);  in percpu_ref_init()
78 		ref->percpu_count_ptr = 0;  in percpu_ref_init()
86 		ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;  in percpu_ref_init()
93 		ref->percpu_count_ptr |= __PERCPU_REF_DEAD;  in percpu_ref_init()
101 	data->ref = ref;  in percpu_ref_init()
102 	ref->data = data;  in percpu_ref_init()
107 static void __percpu_ref_exit(struct percpu_ref *ref)  in __percpu_ref_exit()  argument
109 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in __percpu_ref_exit()
113 		WARN_ON_ONCE(ref->data && ref->data->confirm_switch);  in __percpu_ref_exit()
115 		ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD;  in __percpu_ref_exit()
129 void percpu_ref_exit(struct percpu_ref *ref)  in percpu_ref_exit()  argument
131 	struct percpu_ref_data *data = ref->data;  in percpu_ref_exit()
134 	__percpu_ref_exit(ref);  in percpu_ref_exit()
140 	ref->percpu_count_ptr |= atomic_long_read(&ref->data->count) <<  in percpu_ref_exit()
142 	ref->data = NULL;  in percpu_ref_exit()
153 	struct percpu_ref *ref = data->ref;  in percpu_ref_call_confirm_rcu()  local
155 	data->confirm_switch(ref);  in percpu_ref_call_confirm_rcu()
160 		__percpu_ref_exit(ref);  in percpu_ref_call_confirm_rcu()
163 	percpu_ref_put(ref);  in percpu_ref_call_confirm_rcu()
170 	struct percpu_ref *ref = data->ref;  in percpu_ref_switch_to_atomic_rcu()  local
171 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in percpu_ref_switch_to_atomic_rcu()
203 static void percpu_ref_noop_confirm_switch(struct percpu_ref *ref)  in percpu_ref_noop_confirm_switch()  argument
207 static void __percpu_ref_switch_to_atomic(struct percpu_ref *ref,  in __percpu_ref_switch_to_atomic()  argument
210 	if (ref->percpu_count_ptr & __PERCPU_REF_ATOMIC) {  in __percpu_ref_switch_to_atomic()
212 			confirm_switch(ref);  in __percpu_ref_switch_to_atomic()
217 	ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;  in __percpu_ref_switch_to_atomic()
223 	ref->data->confirm_switch = confirm_switch ?:  in __percpu_ref_switch_to_atomic()
226 	percpu_ref_get(ref);	/* put after confirmation */  in __percpu_ref_switch_to_atomic()
227 	call_rcu(&ref->data->rcu, percpu_ref_switch_to_atomic_rcu);  in __percpu_ref_switch_to_atomic()
230 static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)  in __percpu_ref_switch_to_percpu()  argument
232 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in __percpu_ref_switch_to_percpu()
237 	if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC))  in __percpu_ref_switch_to_percpu()
240 	if (WARN_ON_ONCE(!ref->data->allow_reinit))  in __percpu_ref_switch_to_percpu()
243 	atomic_long_add(PERCPU_COUNT_BIAS, &ref->data->count);  in __percpu_ref_switch_to_percpu()
254 	smp_store_release(&ref->percpu_count_ptr,  in __percpu_ref_switch_to_percpu()
255 			  ref->percpu_count_ptr & ~__PERCPU_REF_ATOMIC);  in __percpu_ref_switch_to_percpu()
258 static void __percpu_ref_switch_mode(struct percpu_ref *ref,  in __percpu_ref_switch_mode()  argument
261 	struct percpu_ref_data *data = ref->data;  in __percpu_ref_switch_mode()
273 	if (data->force_atomic || (ref->percpu_count_ptr & __PERCPU_REF_DEAD))  in __percpu_ref_switch_mode()
274 		__percpu_ref_switch_to_atomic(ref, confirm_switch);  in __percpu_ref_switch_mode()
276 		__percpu_ref_switch_to_percpu(ref);  in __percpu_ref_switch_mode()
299 void percpu_ref_switch_to_atomic(struct percpu_ref *ref,  in percpu_ref_switch_to_atomic()  argument
306 	ref->data->force_atomic = true;  in percpu_ref_switch_to_atomic()
307 	__percpu_ref_switch_mode(ref, confirm_switch);  in percpu_ref_switch_to_atomic()
321 void percpu_ref_switch_to_atomic_sync(struct percpu_ref *ref)  in percpu_ref_switch_to_atomic_sync()  argument
323 	percpu_ref_switch_to_atomic(ref, NULL);  in percpu_ref_switch_to_atomic_sync()
324 	wait_event(percpu_ref_switch_waitq, !ref->data->confirm_switch);  in percpu_ref_switch_to_atomic_sync()
346 void percpu_ref_switch_to_percpu(struct percpu_ref *ref)  in percpu_ref_switch_to_percpu()  argument
352 	ref->data->force_atomic = false;  in percpu_ref_switch_to_percpu()
353 	__percpu_ref_switch_mode(ref, NULL);  in percpu_ref_switch_to_percpu()
376 void percpu_ref_kill_and_confirm(struct percpu_ref *ref,  in percpu_ref_kill_and_confirm()  argument
383 	WARN_ONCE(ref->percpu_count_ptr & __PERCPU_REF_DEAD,  in percpu_ref_kill_and_confirm()
385 		  ref->data->release);  in percpu_ref_kill_and_confirm()
387 	ref->percpu_count_ptr |= __PERCPU_REF_DEAD;  in percpu_ref_kill_and_confirm()
388 	__percpu_ref_switch_mode(ref, confirm_kill);  in percpu_ref_kill_and_confirm()
389 	percpu_ref_put(ref);  in percpu_ref_kill_and_confirm()
403 bool percpu_ref_is_zero(struct percpu_ref *ref)  in percpu_ref_is_zero()  argument
408 	if (__ref_is_percpu(ref, &percpu_count))  in percpu_ref_is_zero()
413 	if (ref->data)  in percpu_ref_is_zero()
414 		count = atomic_long_read(&ref->data->count);  in percpu_ref_is_zero()
416 		count = ref->percpu_count_ptr >> __PERCPU_REF_FLAG_BITS;  in percpu_ref_is_zero()
434 void percpu_ref_reinit(struct percpu_ref *ref)  in percpu_ref_reinit()  argument
436 	WARN_ON_ONCE(!percpu_ref_is_zero(ref));  in percpu_ref_reinit()
438 	percpu_ref_resurrect(ref);  in percpu_ref_reinit()
456 void percpu_ref_resurrect(struct percpu_ref *ref)  in percpu_ref_resurrect()  argument
463 	WARN_ON_ONCE(!(ref->percpu_count_ptr & __PERCPU_REF_DEAD));  in percpu_ref_resurrect()
464 	WARN_ON_ONCE(__ref_is_percpu(ref, &percpu_count));  in percpu_ref_resurrect()
466 	ref->percpu_count_ptr &= ~__PERCPU_REF_DEAD;  in percpu_ref_resurrect()
467 	percpu_ref_get(ref);  in percpu_ref_resurrect()
468 	__percpu_ref_switch_mode(ref, NULL);  in percpu_ref_resurrect()