39 static unsigned long __percpu *percpu_count_ptr(struct percpu_ref *ref)  in percpu_count_ptr()  argument
42 		(ref->percpu_count_ptr & ~__PERCPU_REF_ATOMIC_DEAD);  in percpu_count_ptr()
59 int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release,  in percpu_ref_init()  argument
66 	ref->percpu_count_ptr = (unsigned long)  in percpu_ref_init()
68 	if (!ref->percpu_count_ptr)  in percpu_ref_init()
71 	ref->force_atomic = flags & PERCPU_REF_INIT_ATOMIC;  in percpu_ref_init()
74 		ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;  in percpu_ref_init()
79 		ref->percpu_count_ptr |= __PERCPU_REF_DEAD;  in percpu_ref_init()
83 	atomic_long_set(&ref->count, start_count);  in percpu_ref_init()
85 	ref->release = release;  in percpu_ref_init()
86 	ref->confirm_switch = NULL;  in percpu_ref_init()
101 void percpu_ref_exit(struct percpu_ref *ref)  in percpu_ref_exit()  argument
103 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in percpu_ref_exit()
107 		WARN_ON_ONCE(ref->confirm_switch);  in percpu_ref_exit()
109 		ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD;  in percpu_ref_exit()
116 	struct percpu_ref *ref = container_of(rcu, struct percpu_ref, rcu);  in percpu_ref_call_confirm_rcu()  local
118 	ref->confirm_switch(ref);  in percpu_ref_call_confirm_rcu()
119 	ref->confirm_switch = NULL;  in percpu_ref_call_confirm_rcu()
123 	percpu_ref_put(ref);  in percpu_ref_call_confirm_rcu()
128 	struct percpu_ref *ref = container_of(rcu, struct percpu_ref, rcu);  in percpu_ref_switch_to_atomic_rcu()  local
129 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in percpu_ref_switch_to_atomic_rcu()
137 		 atomic_long_read(&ref->count), (long)count);  in percpu_ref_switch_to_atomic_rcu()
151 	atomic_long_add((long)count - PERCPU_COUNT_BIAS, &ref->count);  in percpu_ref_switch_to_atomic_rcu()
153 	WARN_ONCE(atomic_long_read(&ref->count) <= 0,  in percpu_ref_switch_to_atomic_rcu()
155 		  ref->release, atomic_long_read(&ref->count));  in percpu_ref_switch_to_atomic_rcu()
161 static void percpu_ref_noop_confirm_switch(struct percpu_ref *ref)  in percpu_ref_noop_confirm_switch()  argument
165 static void __percpu_ref_switch_to_atomic(struct percpu_ref *ref,  in __percpu_ref_switch_to_atomic()  argument
168 	if (ref->percpu_count_ptr & __PERCPU_REF_ATOMIC) {  in __percpu_ref_switch_to_atomic()
170 			confirm_switch(ref);  in __percpu_ref_switch_to_atomic()
175 	ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;  in __percpu_ref_switch_to_atomic()
181 	ref->confirm_switch = confirm_switch ?: percpu_ref_noop_confirm_switch;  in __percpu_ref_switch_to_atomic()
183 	percpu_ref_get(ref);	/* put after confirmation */  in __percpu_ref_switch_to_atomic()
184 	call_rcu_sched(&ref->rcu, percpu_ref_switch_to_atomic_rcu);  in __percpu_ref_switch_to_atomic()
187 static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)  in __percpu_ref_switch_to_percpu()  argument
189 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in __percpu_ref_switch_to_percpu()
194 	if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC))  in __percpu_ref_switch_to_percpu()
197 	atomic_long_add(PERCPU_COUNT_BIAS, &ref->count);  in __percpu_ref_switch_to_percpu()
208 	smp_store_release(&ref->percpu_count_ptr,  in __percpu_ref_switch_to_percpu()
209 			  ref->percpu_count_ptr & ~__PERCPU_REF_ATOMIC);  in __percpu_ref_switch_to_percpu()
212 static void __percpu_ref_switch_mode(struct percpu_ref *ref,  in __percpu_ref_switch_mode()  argument
222 	wait_event_lock_irq(percpu_ref_switch_waitq, !ref->confirm_switch,  in __percpu_ref_switch_mode()
225 	if (ref->force_atomic || (ref->percpu_count_ptr & __PERCPU_REF_DEAD))  in __percpu_ref_switch_mode()
226 		__percpu_ref_switch_to_atomic(ref, confirm_switch);  in __percpu_ref_switch_mode()
228 		__percpu_ref_switch_to_percpu(ref);  in __percpu_ref_switch_mode()
251 void percpu_ref_switch_to_atomic(struct percpu_ref *ref,  in percpu_ref_switch_to_atomic()  argument
258 	ref->force_atomic = true;  in percpu_ref_switch_to_atomic()
259 	__percpu_ref_switch_mode(ref, confirm_switch);  in percpu_ref_switch_to_atomic()
273 void percpu_ref_switch_to_atomic_sync(struct percpu_ref *ref)  in percpu_ref_switch_to_atomic_sync()  argument
275 	percpu_ref_switch_to_atomic(ref, NULL);  in percpu_ref_switch_to_atomic_sync()
276 	wait_event(percpu_ref_switch_waitq, !ref->confirm_switch);  in percpu_ref_switch_to_atomic_sync()
298 void percpu_ref_switch_to_percpu(struct percpu_ref *ref)  in percpu_ref_switch_to_percpu()  argument
304 	ref->force_atomic = false;  in percpu_ref_switch_to_percpu()
305 	__percpu_ref_switch_mode(ref, NULL);  in percpu_ref_switch_to_percpu()
328 void percpu_ref_kill_and_confirm(struct percpu_ref *ref,  in percpu_ref_kill_and_confirm()  argument
335 	WARN_ONCE(ref->percpu_count_ptr & __PERCPU_REF_DEAD,  in percpu_ref_kill_and_confirm()
336 		  "%s called more than once on %pf!", __func__, ref->release);  in percpu_ref_kill_and_confirm()
338 	ref->percpu_count_ptr |= __PERCPU_REF_DEAD;  in percpu_ref_kill_and_confirm()
339 	__percpu_ref_switch_mode(ref, confirm_kill);  in percpu_ref_kill_and_confirm()
340 	percpu_ref_put(ref);  in percpu_ref_kill_and_confirm()
357 void percpu_ref_reinit(struct percpu_ref *ref)  in percpu_ref_reinit()  argument
363 	WARN_ON_ONCE(!percpu_ref_is_zero(ref));  in percpu_ref_reinit()
365 	ref->percpu_count_ptr &= ~__PERCPU_REF_DEAD;  in percpu_ref_reinit()
366 	percpu_ref_get(ref);  in percpu_ref_reinit()
367 	__percpu_ref_switch_mode(ref, NULL);  in percpu_ref_reinit()