38 static unsigned long __percpu *percpu_count_ptr(struct percpu_ref *ref)  in percpu_count_ptr()  argument
41 		(ref->percpu_count_ptr & ~__PERCPU_REF_ATOMIC_DEAD);  in percpu_count_ptr()
58 int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release,  in percpu_ref_init()  argument
65 	ref->percpu_count_ptr = (unsigned long)  in percpu_ref_init()
67 	if (!ref->percpu_count_ptr)  in percpu_ref_init()
70 	ref->force_atomic = flags & PERCPU_REF_INIT_ATOMIC;  in percpu_ref_init()
73 		ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;  in percpu_ref_init()
78 		ref->percpu_count_ptr |= __PERCPU_REF_DEAD;  in percpu_ref_init()
82 	atomic_long_set(&ref->count, start_count);  in percpu_ref_init()
84 	ref->release = release;  in percpu_ref_init()
99 void percpu_ref_exit(struct percpu_ref *ref)  in percpu_ref_exit()  argument
101 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in percpu_ref_exit()
105 		ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD;  in percpu_ref_exit()
112 	struct percpu_ref *ref = container_of(rcu, struct percpu_ref, rcu);  in percpu_ref_call_confirm_rcu()  local
114 	ref->confirm_switch(ref);  in percpu_ref_call_confirm_rcu()
115 	ref->confirm_switch = NULL;  in percpu_ref_call_confirm_rcu()
119 	percpu_ref_put(ref);  in percpu_ref_call_confirm_rcu()
124 	struct percpu_ref *ref = container_of(rcu, struct percpu_ref, rcu);  in percpu_ref_switch_to_atomic_rcu()  local
125 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in percpu_ref_switch_to_atomic_rcu()
133 		 atomic_long_read(&ref->count), (long)count);  in percpu_ref_switch_to_atomic_rcu()
147 	atomic_long_add((long)count - PERCPU_COUNT_BIAS, &ref->count);  in percpu_ref_switch_to_atomic_rcu()
149 	WARN_ONCE(atomic_long_read(&ref->count) <= 0,  in percpu_ref_switch_to_atomic_rcu()
151 		  ref->release, atomic_long_read(&ref->count));  in percpu_ref_switch_to_atomic_rcu()
157 static void percpu_ref_noop_confirm_switch(struct percpu_ref *ref)  in percpu_ref_noop_confirm_switch()  argument
161 static void __percpu_ref_switch_to_atomic(struct percpu_ref *ref,  in __percpu_ref_switch_to_atomic()  argument
164 	if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC)) {  in __percpu_ref_switch_to_atomic()
166 		ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;  in __percpu_ref_switch_to_atomic()
172 		WARN_ON_ONCE(ref->confirm_switch);  in __percpu_ref_switch_to_atomic()
173 		ref->confirm_switch =  in __percpu_ref_switch_to_atomic()
176 		percpu_ref_get(ref);	/* put after confirmation */  in __percpu_ref_switch_to_atomic()
177 		call_rcu_sched(&ref->rcu, percpu_ref_switch_to_atomic_rcu);  in __percpu_ref_switch_to_atomic()
186 		wait_event(percpu_ref_switch_waitq, !ref->confirm_switch);  in __percpu_ref_switch_to_atomic()
187 		ref->confirm_switch = confirm_switch;  in __percpu_ref_switch_to_atomic()
189 		percpu_ref_get(ref);	/* put after confirmation */  in __percpu_ref_switch_to_atomic()
190 		call_rcu_sched(&ref->rcu, percpu_ref_call_confirm_rcu);  in __percpu_ref_switch_to_atomic()
219 void percpu_ref_switch_to_atomic(struct percpu_ref *ref,  in percpu_ref_switch_to_atomic()  argument
222 	ref->force_atomic = true;  in percpu_ref_switch_to_atomic()
223 	__percpu_ref_switch_to_atomic(ref, confirm_switch);  in percpu_ref_switch_to_atomic()
226 static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)  in __percpu_ref_switch_to_percpu()  argument
228 	unsigned long __percpu *percpu_count = percpu_count_ptr(ref);  in __percpu_ref_switch_to_percpu()
233 	if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC))  in __percpu_ref_switch_to_percpu()
236 	wait_event(percpu_ref_switch_waitq, !ref->confirm_switch);  in __percpu_ref_switch_to_percpu()
238 	atomic_long_add(PERCPU_COUNT_BIAS, &ref->count);  in __percpu_ref_switch_to_percpu()
249 	smp_store_release(&ref->percpu_count_ptr,  in __percpu_ref_switch_to_percpu()
250 			  ref->percpu_count_ptr & ~__PERCPU_REF_ATOMIC);  in __percpu_ref_switch_to_percpu()
271 void percpu_ref_switch_to_percpu(struct percpu_ref *ref)  in percpu_ref_switch_to_percpu()  argument
273 	ref->force_atomic = false;  in percpu_ref_switch_to_percpu()
276 	if (!(ref->percpu_count_ptr & __PERCPU_REF_DEAD))  in percpu_ref_switch_to_percpu()
277 		__percpu_ref_switch_to_percpu(ref);  in percpu_ref_switch_to_percpu()
299 void percpu_ref_kill_and_confirm(struct percpu_ref *ref,  in percpu_ref_kill_and_confirm()  argument
302 	WARN_ONCE(ref->percpu_count_ptr & __PERCPU_REF_DEAD,  in percpu_ref_kill_and_confirm()
303 		  "%s called more than once on %pf!", __func__, ref->release);  in percpu_ref_kill_and_confirm()
305 	ref->percpu_count_ptr |= __PERCPU_REF_DEAD;  in percpu_ref_kill_and_confirm()
306 	__percpu_ref_switch_to_atomic(ref, confirm_kill);  in percpu_ref_kill_and_confirm()
307 	percpu_ref_put(ref);  in percpu_ref_kill_and_confirm()
322 void percpu_ref_reinit(struct percpu_ref *ref)  in percpu_ref_reinit()  argument
324 	WARN_ON_ONCE(!percpu_ref_is_zero(ref));  in percpu_ref_reinit()
326 	ref->percpu_count_ptr &= ~__PERCPU_REF_DEAD;  in percpu_ref_reinit()
327 	percpu_ref_get(ref);  in percpu_ref_reinit()
328 	if (!ref->force_atomic)  in percpu_ref_reinit()
329 		__percpu_ref_switch_to_percpu(ref);  in percpu_ref_reinit()