1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Read-Copy Update definitions shared among RCU implementations.
4  *
5  * Copyright IBM Corporation, 2011
6  *
7  * Author: Paul E. McKenney <paulmck@linux.ibm.com>
8  */
9 
10 #ifndef __LINUX_RCU_H
11 #define __LINUX_RCU_H
12 
13 #include <trace/events/rcu.h>
14 
15 /* Offset to allow distinguishing irq vs. task-based idle entry/exit. */
16 #define DYNTICK_IRQ_NONIDLE	((LONG_MAX / 2) + 1)
17 
18 
19 /*
20  * Grace-period counter management.
21  */
22 
23 #define RCU_SEQ_CTR_SHIFT	2
24 #define RCU_SEQ_STATE_MASK	((1 << RCU_SEQ_CTR_SHIFT) - 1)
25 
26 extern int sysctl_sched_rt_runtime;
27 
28 /*
29  * Return the counter portion of a sequence number previously returned
30  * by rcu_seq_snap() or rcu_seq_current().
31  */
rcu_seq_ctr(unsigned long s)32 static inline unsigned long rcu_seq_ctr(unsigned long s)
33 {
34 	return s >> RCU_SEQ_CTR_SHIFT;
35 }
36 
37 /*
38  * Return the state portion of a sequence number previously returned
39  * by rcu_seq_snap() or rcu_seq_current().
40  */
rcu_seq_state(unsigned long s)41 static inline int rcu_seq_state(unsigned long s)
42 {
43 	return s & RCU_SEQ_STATE_MASK;
44 }
45 
46 /*
47  * Set the state portion of the pointed-to sequence number.
48  * The caller is responsible for preventing conflicting updates.
49  */
rcu_seq_set_state(unsigned long * sp,int newstate)50 static inline void rcu_seq_set_state(unsigned long *sp, int newstate)
51 {
52 	WARN_ON_ONCE(newstate & ~RCU_SEQ_STATE_MASK);
53 	WRITE_ONCE(*sp, (*sp & ~RCU_SEQ_STATE_MASK) + newstate);
54 }
55 
56 /* Adjust sequence number for start of update-side operation. */
rcu_seq_start(unsigned long * sp)57 static inline void rcu_seq_start(unsigned long *sp)
58 {
59 	WRITE_ONCE(*sp, *sp + 1);
60 	smp_mb(); /* Ensure update-side operation after counter increment. */
61 	WARN_ON_ONCE(rcu_seq_state(*sp) != 1);
62 }
63 
64 /* Compute the end-of-grace-period value for the specified sequence number. */
rcu_seq_endval(unsigned long * sp)65 static inline unsigned long rcu_seq_endval(unsigned long *sp)
66 {
67 	return (*sp | RCU_SEQ_STATE_MASK) + 1;
68 }
69 
70 /* Adjust sequence number for end of update-side operation. */
rcu_seq_end(unsigned long * sp)71 static inline void rcu_seq_end(unsigned long *sp)
72 {
73 	smp_mb(); /* Ensure update-side operation before counter increment. */
74 	WARN_ON_ONCE(!rcu_seq_state(*sp));
75 	WRITE_ONCE(*sp, rcu_seq_endval(sp));
76 }
77 
78 /*
79  * rcu_seq_snap - Take a snapshot of the update side's sequence number.
80  *
81  * This function returns the earliest value of the grace-period sequence number
82  * that will indicate that a full grace period has elapsed since the current
83  * time.  Once the grace-period sequence number has reached this value, it will
84  * be safe to invoke all callbacks that have been registered prior to the
85  * current time. This value is the current grace-period number plus two to the
86  * power of the number of low-order bits reserved for state, then rounded up to
87  * the next value in which the state bits are all zero.
88  */
rcu_seq_snap(unsigned long * sp)89 static inline unsigned long rcu_seq_snap(unsigned long *sp)
90 {
91 	unsigned long s;
92 
93 	s = (READ_ONCE(*sp) + 2 * RCU_SEQ_STATE_MASK + 1) & ~RCU_SEQ_STATE_MASK;
94 	smp_mb(); /* Above access must not bleed into critical section. */
95 	return s;
96 }
97 
98 /* Return the current value the update side's sequence number, no ordering. */
rcu_seq_current(unsigned long * sp)99 static inline unsigned long rcu_seq_current(unsigned long *sp)
100 {
101 	return READ_ONCE(*sp);
102 }
103 
104 /*
105  * Given a snapshot from rcu_seq_snap(), determine whether or not the
106  * corresponding update-side operation has started.
107  */
rcu_seq_started(unsigned long * sp,unsigned long s)108 static inline bool rcu_seq_started(unsigned long *sp, unsigned long s)
109 {
110 	return ULONG_CMP_LT((s - 1) & ~RCU_SEQ_STATE_MASK, READ_ONCE(*sp));
111 }
112 
113 /*
114  * Given a snapshot from rcu_seq_snap(), determine whether or not a
115  * full update-side operation has occurred.
116  */
rcu_seq_done(unsigned long * sp,unsigned long s)117 static inline bool rcu_seq_done(unsigned long *sp, unsigned long s)
118 {
119 	return ULONG_CMP_GE(READ_ONCE(*sp), s);
120 }
121 
122 /*
123  * Has a grace period completed since the time the old gp_seq was collected?
124  */
rcu_seq_completed_gp(unsigned long old,unsigned long new)125 static inline bool rcu_seq_completed_gp(unsigned long old, unsigned long new)
126 {
127 	return ULONG_CMP_LT(old, new & ~RCU_SEQ_STATE_MASK);
128 }
129 
130 /*
131  * Has a grace period started since the time the old gp_seq was collected?
132  */
rcu_seq_new_gp(unsigned long old,unsigned long new)133 static inline bool rcu_seq_new_gp(unsigned long old, unsigned long new)
134 {
135 	return ULONG_CMP_LT((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK,
136 			    new);
137 }
138 
139 /*
140  * Roughly how many full grace periods have elapsed between the collection
141  * of the two specified grace periods?
142  */
rcu_seq_diff(unsigned long new,unsigned long old)143 static inline unsigned long rcu_seq_diff(unsigned long new, unsigned long old)
144 {
145 	unsigned long rnd_diff;
146 
147 	if (old == new)
148 		return 0;
149 	/*
150 	 * Compute the number of grace periods (still shifted up), plus
151 	 * one if either of new and old is not an exact grace period.
152 	 */
153 	rnd_diff = (new & ~RCU_SEQ_STATE_MASK) -
154 		   ((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK) +
155 		   ((new & RCU_SEQ_STATE_MASK) || (old & RCU_SEQ_STATE_MASK));
156 	if (ULONG_CMP_GE(RCU_SEQ_STATE_MASK, rnd_diff))
157 		return 1; /* Definitely no grace period has elapsed. */
158 	return ((rnd_diff - RCU_SEQ_STATE_MASK - 1) >> RCU_SEQ_CTR_SHIFT) + 2;
159 }
160 
161 /*
162  * debug_rcu_head_queue()/debug_rcu_head_unqueue() are used internally
163  * by call_rcu() and rcu callback execution, and are therefore not part
164  * of the RCU API. These are in rcupdate.h because they are used by all
165  * RCU implementations.
166  */
167 
168 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
169 # define STATE_RCU_HEAD_READY	0
170 # define STATE_RCU_HEAD_QUEUED	1
171 
172 extern const struct debug_obj_descr rcuhead_debug_descr;
173 
debug_rcu_head_queue(struct rcu_head * head)174 static inline int debug_rcu_head_queue(struct rcu_head *head)
175 {
176 	int r1;
177 
178 	r1 = debug_object_activate(head, &rcuhead_debug_descr);
179 	debug_object_active_state(head, &rcuhead_debug_descr,
180 				  STATE_RCU_HEAD_READY,
181 				  STATE_RCU_HEAD_QUEUED);
182 	return r1;
183 }
184 
debug_rcu_head_unqueue(struct rcu_head * head)185 static inline void debug_rcu_head_unqueue(struct rcu_head *head)
186 {
187 	debug_object_active_state(head, &rcuhead_debug_descr,
188 				  STATE_RCU_HEAD_QUEUED,
189 				  STATE_RCU_HEAD_READY);
190 	debug_object_deactivate(head, &rcuhead_debug_descr);
191 }
192 #else	/* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
debug_rcu_head_queue(struct rcu_head * head)193 static inline int debug_rcu_head_queue(struct rcu_head *head)
194 {
195 	return 0;
196 }
197 
debug_rcu_head_unqueue(struct rcu_head * head)198 static inline void debug_rcu_head_unqueue(struct rcu_head *head)
199 {
200 }
201 #endif	/* #else !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
202 
203 extern int rcu_cpu_stall_suppress_at_boot;
204 
rcu_stall_is_suppressed_at_boot(void)205 static inline bool rcu_stall_is_suppressed_at_boot(void)
206 {
207 	return rcu_cpu_stall_suppress_at_boot && !rcu_inkernel_boot_has_ended();
208 }
209 
210 #ifdef CONFIG_RCU_STALL_COMMON
211 
212 extern int rcu_cpu_stall_ftrace_dump;
213 extern int rcu_cpu_stall_suppress;
214 extern int rcu_cpu_stall_timeout;
215 extern int rcu_exp_cpu_stall_timeout;
216 int rcu_jiffies_till_stall_check(void);
217 int rcu_exp_jiffies_till_stall_check(void);
218 
rcu_stall_is_suppressed(void)219 static inline bool rcu_stall_is_suppressed(void)
220 {
221 	return rcu_stall_is_suppressed_at_boot() || rcu_cpu_stall_suppress;
222 }
223 
224 #define rcu_ftrace_dump_stall_suppress() \
225 do { \
226 	if (!rcu_cpu_stall_suppress) \
227 		rcu_cpu_stall_suppress = 3; \
228 } while (0)
229 
230 #define rcu_ftrace_dump_stall_unsuppress() \
231 do { \
232 	if (rcu_cpu_stall_suppress == 3) \
233 		rcu_cpu_stall_suppress = 0; \
234 } while (0)
235 
236 #else /* #endif #ifdef CONFIG_RCU_STALL_COMMON */
237 
rcu_stall_is_suppressed(void)238 static inline bool rcu_stall_is_suppressed(void)
239 {
240 	return rcu_stall_is_suppressed_at_boot();
241 }
242 #define rcu_ftrace_dump_stall_suppress()
243 #define rcu_ftrace_dump_stall_unsuppress()
244 #endif /* #ifdef CONFIG_RCU_STALL_COMMON */
245 
246 /*
247  * Strings used in tracepoints need to be exported via the
248  * tracing system such that tools like perf and trace-cmd can
249  * translate the string address pointers to actual text.
250  */
251 #define TPS(x)  tracepoint_string(x)
252 
253 /*
254  * Dump the ftrace buffer, but only one time per callsite per boot.
255  */
256 #define rcu_ftrace_dump(oops_dump_mode) \
257 do { \
258 	static atomic_t ___rfd_beenhere = ATOMIC_INIT(0); \
259 	\
260 	if (!atomic_read(&___rfd_beenhere) && \
261 	    !atomic_xchg(&___rfd_beenhere, 1)) { \
262 		tracing_off(); \
263 		rcu_ftrace_dump_stall_suppress(); \
264 		ftrace_dump(oops_dump_mode); \
265 		rcu_ftrace_dump_stall_unsuppress(); \
266 	} \
267 } while (0)
268 
269 void rcu_early_boot_tests(void);
270 void rcu_test_sync_prims(void);
271 
272 /*
273  * This function really isn't for public consumption, but RCU is special in
274  * that context switches can allow the state machine to make progress.
275  */
276 extern void resched_cpu(int cpu);
277 
278 #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU)
279 
280 #include <linux/rcu_node_tree.h>
281 
282 extern int rcu_num_lvls;
283 extern int num_rcu_lvl[];
284 extern int rcu_num_nodes;
285 static bool rcu_fanout_exact;
286 static int rcu_fanout_leaf;
287 
288 /*
289  * Compute the per-level fanout, either using the exact fanout specified
290  * or balancing the tree, depending on the rcu_fanout_exact boot parameter.
291  */
rcu_init_levelspread(int * levelspread,const int * levelcnt)292 static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt)
293 {
294 	int i;
295 
296 	for (i = 0; i < RCU_NUM_LVLS; i++)
297 		levelspread[i] = INT_MIN;
298 	if (rcu_fanout_exact) {
299 		levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf;
300 		for (i = rcu_num_lvls - 2; i >= 0; i--)
301 			levelspread[i] = RCU_FANOUT;
302 	} else {
303 		int ccur;
304 		int cprv;
305 
306 		cprv = nr_cpu_ids;
307 		for (i = rcu_num_lvls - 1; i >= 0; i--) {
308 			ccur = levelcnt[i];
309 			levelspread[i] = (cprv + ccur - 1) / ccur;
310 			cprv = ccur;
311 		}
312 	}
313 }
314 
315 extern void rcu_init_geometry(void);
316 
317 /* Returns a pointer to the first leaf rcu_node structure. */
318 #define rcu_first_leaf_node() (rcu_state.level[rcu_num_lvls - 1])
319 
320 /* Is this rcu_node a leaf? */
321 #define rcu_is_leaf_node(rnp) ((rnp)->level == rcu_num_lvls - 1)
322 
323 /* Is this rcu_node the last leaf? */
324 #define rcu_is_last_leaf_node(rnp) ((rnp) == &rcu_state.node[rcu_num_nodes - 1])
325 
326 /*
327  * Do a full breadth-first scan of the {s,}rcu_node structures for the
328  * specified state structure (for SRCU) or the only rcu_state structure
329  * (for RCU).
330  */
331 #define srcu_for_each_node_breadth_first(sp, rnp) \
332 	for ((rnp) = &(sp)->node[0]; \
333 	     (rnp) < &(sp)->node[rcu_num_nodes]; (rnp)++)
334 #define rcu_for_each_node_breadth_first(rnp) \
335 	srcu_for_each_node_breadth_first(&rcu_state, rnp)
336 
337 /*
338  * Scan the leaves of the rcu_node hierarchy for the rcu_state structure.
339  * Note that if there is a singleton rcu_node tree with but one rcu_node
340  * structure, this loop -will- visit the rcu_node structure.  It is still
341  * a leaf node, even if it is also the root node.
342  */
343 #define rcu_for_each_leaf_node(rnp) \
344 	for ((rnp) = rcu_first_leaf_node(); \
345 	     (rnp) < &rcu_state.node[rcu_num_nodes]; (rnp)++)
346 
347 /*
348  * Iterate over all possible CPUs in a leaf RCU node.
349  */
350 #define for_each_leaf_node_possible_cpu(rnp, cpu) \
351 	for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \
352 	     (cpu) = cpumask_next((rnp)->grplo - 1, cpu_possible_mask); \
353 	     (cpu) <= rnp->grphi; \
354 	     (cpu) = cpumask_next((cpu), cpu_possible_mask))
355 
356 /*
357  * Iterate over all CPUs in a leaf RCU node's specified mask.
358  */
359 #define rcu_find_next_bit(rnp, cpu, mask) \
360 	((rnp)->grplo + find_next_bit(&(mask), BITS_PER_LONG, (cpu)))
361 #define for_each_leaf_node_cpu_mask(rnp, cpu, mask) \
362 	for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \
363 	     (cpu) = rcu_find_next_bit((rnp), 0, (mask)); \
364 	     (cpu) <= rnp->grphi; \
365 	     (cpu) = rcu_find_next_bit((rnp), (cpu) + 1 - (rnp->grplo), (mask)))
366 
367 /*
368  * Wrappers for the rcu_node::lock acquire and release.
369  *
370  * Because the rcu_nodes form a tree, the tree traversal locking will observe
371  * different lock values, this in turn means that an UNLOCK of one level
372  * followed by a LOCK of another level does not imply a full memory barrier;
373  * and most importantly transitivity is lost.
374  *
375  * In order to restore full ordering between tree levels, augment the regular
376  * lock acquire functions with smp_mb__after_unlock_lock().
377  *
378  * As ->lock of struct rcu_node is a __private field, therefore one should use
379  * these wrappers rather than directly call raw_spin_{lock,unlock}* on ->lock.
380  */
381 #define raw_spin_lock_rcu_node(p)					\
382 do {									\
383 	raw_spin_lock(&ACCESS_PRIVATE(p, lock));			\
384 	smp_mb__after_unlock_lock();					\
385 } while (0)
386 
387 #define raw_spin_unlock_rcu_node(p)					\
388 do {									\
389 	lockdep_assert_irqs_disabled();					\
390 	raw_spin_unlock(&ACCESS_PRIVATE(p, lock));			\
391 } while (0)
392 
393 #define raw_spin_lock_irq_rcu_node(p)					\
394 do {									\
395 	raw_spin_lock_irq(&ACCESS_PRIVATE(p, lock));			\
396 	smp_mb__after_unlock_lock();					\
397 } while (0)
398 
399 #define raw_spin_unlock_irq_rcu_node(p)					\
400 do {									\
401 	lockdep_assert_irqs_disabled();					\
402 	raw_spin_unlock_irq(&ACCESS_PRIVATE(p, lock));			\
403 } while (0)
404 
405 #define raw_spin_lock_irqsave_rcu_node(p, flags)			\
406 do {									\
407 	raw_spin_lock_irqsave(&ACCESS_PRIVATE(p, lock), flags);	\
408 	smp_mb__after_unlock_lock();					\
409 } while (0)
410 
411 #define raw_spin_unlock_irqrestore_rcu_node(p, flags)			\
412 do {									\
413 	lockdep_assert_irqs_disabled();					\
414 	raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags);	\
415 } while (0)
416 
417 #define raw_spin_trylock_rcu_node(p)					\
418 ({									\
419 	bool ___locked = raw_spin_trylock(&ACCESS_PRIVATE(p, lock));	\
420 									\
421 	if (___locked)							\
422 		smp_mb__after_unlock_lock();				\
423 	___locked;							\
424 })
425 
426 #define raw_lockdep_assert_held_rcu_node(p)				\
427 	lockdep_assert_held(&ACCESS_PRIVATE(p, lock))
428 
429 #endif /* #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) */
430 
431 #ifdef CONFIG_TINY_RCU
432 /* Tiny RCU doesn't expedite, as its purpose in life is instead to be tiny. */
rcu_gp_is_normal(void)433 static inline bool rcu_gp_is_normal(void) { return true; }
rcu_gp_is_expedited(void)434 static inline bool rcu_gp_is_expedited(void) { return false; }
rcu_expedite_gp(void)435 static inline void rcu_expedite_gp(void) { }
rcu_unexpedite_gp(void)436 static inline void rcu_unexpedite_gp(void) { }
rcu_request_urgent_qs_task(struct task_struct * t)437 static inline void rcu_request_urgent_qs_task(struct task_struct *t) { }
438 #else /* #ifdef CONFIG_TINY_RCU */
439 bool rcu_gp_is_normal(void);     /* Internal RCU use. */
440 bool rcu_gp_is_expedited(void);  /* Internal RCU use. */
441 void rcu_expedite_gp(void);
442 void rcu_unexpedite_gp(void);
443 void rcupdate_announce_bootup_oddness(void);
444 #ifdef CONFIG_TASKS_RCU_GENERIC
445 void show_rcu_tasks_gp_kthreads(void);
446 #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
show_rcu_tasks_gp_kthreads(void)447 static inline void show_rcu_tasks_gp_kthreads(void) {}
448 #endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */
449 void rcu_request_urgent_qs_task(struct task_struct *t);
450 #endif /* #else #ifdef CONFIG_TINY_RCU */
451 
452 #define RCU_SCHEDULER_INACTIVE	0
453 #define RCU_SCHEDULER_INIT	1
454 #define RCU_SCHEDULER_RUNNING	2
455 
456 enum rcutorture_type {
457 	RCU_FLAVOR,
458 	RCU_TASKS_FLAVOR,
459 	RCU_TASKS_RUDE_FLAVOR,
460 	RCU_TASKS_TRACING_FLAVOR,
461 	RCU_TRIVIAL_FLAVOR,
462 	SRCU_FLAVOR,
463 	INVALID_RCU_FLAVOR
464 };
465 
466 #if defined(CONFIG_TREE_RCU)
467 void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,
468 			    unsigned long *gp_seq);
469 void do_trace_rcu_torture_read(const char *rcutorturename,
470 			       struct rcu_head *rhp,
471 			       unsigned long secs,
472 			       unsigned long c_old,
473 			       unsigned long c);
474 void rcu_gp_set_torture_wait(int duration);
475 #else
rcutorture_get_gp_data(enum rcutorture_type test_type,int * flags,unsigned long * gp_seq)476 static inline void rcutorture_get_gp_data(enum rcutorture_type test_type,
477 					  int *flags, unsigned long *gp_seq)
478 {
479 	*flags = 0;
480 	*gp_seq = 0;
481 }
482 #ifdef CONFIG_RCU_TRACE
483 void do_trace_rcu_torture_read(const char *rcutorturename,
484 			       struct rcu_head *rhp,
485 			       unsigned long secs,
486 			       unsigned long c_old,
487 			       unsigned long c);
488 #else
489 #define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
490 	do { } while (0)
491 #endif
rcu_gp_set_torture_wait(int duration)492 static inline void rcu_gp_set_torture_wait(int duration) { }
493 #endif
494 
495 #if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST)
496 long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask);
497 #endif
498 
499 #ifdef CONFIG_TINY_SRCU
500 
srcutorture_get_gp_data(enum rcutorture_type test_type,struct srcu_struct * sp,int * flags,unsigned long * gp_seq)501 static inline void srcutorture_get_gp_data(enum rcutorture_type test_type,
502 					   struct srcu_struct *sp, int *flags,
503 					   unsigned long *gp_seq)
504 {
505 	if (test_type != SRCU_FLAVOR)
506 		return;
507 	*flags = 0;
508 	*gp_seq = sp->srcu_idx;
509 }
510 
511 #elif defined(CONFIG_TREE_SRCU)
512 
513 void srcutorture_get_gp_data(enum rcutorture_type test_type,
514 			     struct srcu_struct *sp, int *flags,
515 			     unsigned long *gp_seq);
516 
517 #endif
518 
519 #ifdef CONFIG_TINY_RCU
rcu_dynticks_zero_in_eqs(int cpu,int * vp)520 static inline bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) { return false; }
rcu_get_gp_seq(void)521 static inline unsigned long rcu_get_gp_seq(void) { return 0; }
rcu_exp_batches_completed(void)522 static inline unsigned long rcu_exp_batches_completed(void) { return 0; }
523 static inline unsigned long
srcu_batches_completed(struct srcu_struct * sp)524 srcu_batches_completed(struct srcu_struct *sp) { return 0; }
rcu_force_quiescent_state(void)525 static inline void rcu_force_quiescent_state(void) { }
rcu_check_boost_fail(unsigned long gp_state,int * cpup)526 static inline bool rcu_check_boost_fail(unsigned long gp_state, int *cpup) { return true; }
show_rcu_gp_kthreads(void)527 static inline void show_rcu_gp_kthreads(void) { }
rcu_get_gp_kthreads_prio(void)528 static inline int rcu_get_gp_kthreads_prio(void) { return 0; }
rcu_fwd_progress_check(unsigned long j)529 static inline void rcu_fwd_progress_check(unsigned long j) { }
rcu_gp_slow_register(atomic_t * rgssp)530 static inline void rcu_gp_slow_register(atomic_t *rgssp) { }
rcu_gp_slow_unregister(atomic_t * rgssp)531 static inline void rcu_gp_slow_unregister(atomic_t *rgssp) { }
532 #else /* #ifdef CONFIG_TINY_RCU */
533 bool rcu_dynticks_zero_in_eqs(int cpu, int *vp);
534 unsigned long rcu_get_gp_seq(void);
535 unsigned long rcu_exp_batches_completed(void);
536 unsigned long srcu_batches_completed(struct srcu_struct *sp);
537 bool rcu_check_boost_fail(unsigned long gp_state, int *cpup);
538 void show_rcu_gp_kthreads(void);
539 int rcu_get_gp_kthreads_prio(void);
540 void rcu_fwd_progress_check(unsigned long j);
541 void rcu_force_quiescent_state(void);
542 extern struct workqueue_struct *rcu_gp_wq;
543 #ifdef CONFIG_RCU_EXP_KTHREAD
544 extern struct kthread_worker *rcu_exp_gp_kworker;
545 extern struct kthread_worker *rcu_exp_par_gp_kworker;
546 #else /* !CONFIG_RCU_EXP_KTHREAD */
547 extern struct workqueue_struct *rcu_par_gp_wq;
548 #endif /* CONFIG_RCU_EXP_KTHREAD */
549 void rcu_gp_slow_register(atomic_t *rgssp);
550 void rcu_gp_slow_unregister(atomic_t *rgssp);
551 #endif /* #else #ifdef CONFIG_TINY_RCU */
552 
553 #ifdef CONFIG_RCU_NOCB_CPU
554 void rcu_bind_current_to_nocb(void);
555 #else
rcu_bind_current_to_nocb(void)556 static inline void rcu_bind_current_to_nocb(void) { }
557 #endif
558 
559 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RCU)
560 void show_rcu_tasks_classic_gp_kthread(void);
561 #else
show_rcu_tasks_classic_gp_kthread(void)562 static inline void show_rcu_tasks_classic_gp_kthread(void) {}
563 #endif
564 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RUDE_RCU)
565 void show_rcu_tasks_rude_gp_kthread(void);
566 #else
show_rcu_tasks_rude_gp_kthread(void)567 static inline void show_rcu_tasks_rude_gp_kthread(void) {}
568 #endif
569 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_TRACE_RCU)
570 void show_rcu_tasks_trace_gp_kthread(void);
571 #else
show_rcu_tasks_trace_gp_kthread(void)572 static inline void show_rcu_tasks_trace_gp_kthread(void) {}
573 #endif
574 
575 #endif /* __LINUX_RCU_H */
576