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