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 /*
16 * Grace-period counter management.
17 */
18
19 #define RCU_SEQ_CTR_SHIFT 2
20 #define RCU_SEQ_STATE_MASK ((1 << RCU_SEQ_CTR_SHIFT) - 1)
21
22 /* Low-order bit definition for polled grace-period APIs. */
23 #define RCU_GET_STATE_COMPLETED 0x1
24
25 extern int sysctl_sched_rt_runtime;
26
27 /*
28 * Return the counter portion of a sequence number previously returned
29 * by rcu_seq_snap() or rcu_seq_current().
30 */
rcu_seq_ctr(unsigned long s)31 static inline unsigned long rcu_seq_ctr(unsigned long s)
32 {
33 return s >> RCU_SEQ_CTR_SHIFT;
34 }
35
36 /*
37 * Return the state portion of a sequence number previously returned
38 * by rcu_seq_snap() or rcu_seq_current().
39 */
rcu_seq_state(unsigned long s)40 static inline int rcu_seq_state(unsigned long s)
41 {
42 return s & RCU_SEQ_STATE_MASK;
43 }
44
45 /*
46 * Set the state portion of the pointed-to sequence number.
47 * The caller is responsible for preventing conflicting updates.
48 */
rcu_seq_set_state(unsigned long * sp,int newstate)49 static inline void rcu_seq_set_state(unsigned long *sp, int newstate)
50 {
51 WARN_ON_ONCE(newstate & ~RCU_SEQ_STATE_MASK);
52 WRITE_ONCE(*sp, (*sp & ~RCU_SEQ_STATE_MASK) + newstate);
53 }
54
55 /* Adjust sequence number for start of update-side operation. */
rcu_seq_start(unsigned long * sp)56 static inline void rcu_seq_start(unsigned long *sp)
57 {
58 WRITE_ONCE(*sp, *sp + 1);
59 smp_mb(); /* Ensure update-side operation after counter increment. */
60 WARN_ON_ONCE(rcu_seq_state(*sp) != 1);
61 }
62
63 /* Compute the end-of-grace-period value for the specified sequence number. */
rcu_seq_endval(unsigned long * sp)64 static inline unsigned long rcu_seq_endval(unsigned long *sp)
65 {
66 return (*sp | RCU_SEQ_STATE_MASK) + 1;
67 }
68
69 /* Adjust sequence number for end of update-side operation. */
rcu_seq_end(unsigned long * sp)70 static inline void rcu_seq_end(unsigned long *sp)
71 {
72 smp_mb(); /* Ensure update-side operation before counter increment. */
73 WARN_ON_ONCE(!rcu_seq_state(*sp));
74 WRITE_ONCE(*sp, rcu_seq_endval(sp));
75 }
76
77 /*
78 * rcu_seq_snap - Take a snapshot of the update side's sequence number.
79 *
80 * This function returns the earliest value of the grace-period sequence number
81 * that will indicate that a full grace period has elapsed since the current
82 * time. Once the grace-period sequence number has reached this value, it will
83 * be safe to invoke all callbacks that have been registered prior to the
84 * current time. This value is the current grace-period number plus two to the
85 * power of the number of low-order bits reserved for state, then rounded up to
86 * the next value in which the state bits are all zero.
87 */
rcu_seq_snap(unsigned long * sp)88 static inline unsigned long rcu_seq_snap(unsigned long *sp)
89 {
90 unsigned long s;
91
92 s = (READ_ONCE(*sp) + 2 * RCU_SEQ_STATE_MASK + 1) & ~RCU_SEQ_STATE_MASK;
93 smp_mb(); /* Above access must not bleed into critical section. */
94 return s;
95 }
96
97 /* Return the current value the update side's sequence number, no ordering. */
rcu_seq_current(unsigned long * sp)98 static inline unsigned long rcu_seq_current(unsigned long *sp)
99 {
100 return READ_ONCE(*sp);
101 }
102
103 /*
104 * Given a snapshot from rcu_seq_snap(), determine whether or not the
105 * corresponding update-side operation has started.
106 */
rcu_seq_started(unsigned long * sp,unsigned long s)107 static inline bool rcu_seq_started(unsigned long *sp, unsigned long s)
108 {
109 return ULONG_CMP_LT((s - 1) & ~RCU_SEQ_STATE_MASK, READ_ONCE(*sp));
110 }
111
112 /*
113 * Given a snapshot from rcu_seq_snap(), determine whether or not a
114 * full update-side operation has occurred.
115 */
rcu_seq_done(unsigned long * sp,unsigned long s)116 static inline bool rcu_seq_done(unsigned long *sp, unsigned long s)
117 {
118 return ULONG_CMP_GE(READ_ONCE(*sp), s);
119 }
120
121 /*
122 * Given a snapshot from rcu_seq_snap(), determine whether or not a
123 * full update-side operation has occurred, but do not allow the
124 * (ULONG_MAX / 2) safety-factor/guard-band.
125 */
rcu_seq_done_exact(unsigned long * sp,unsigned long s)126 static inline bool rcu_seq_done_exact(unsigned long *sp, unsigned long s)
127 {
128 unsigned long cur_s = READ_ONCE(*sp);
129
130 return ULONG_CMP_GE(cur_s, s) || ULONG_CMP_LT(cur_s, s - (2 * RCU_SEQ_STATE_MASK + 1));
131 }
132
133 /*
134 * Has a grace period completed since the time the old gp_seq was collected?
135 */
rcu_seq_completed_gp(unsigned long old,unsigned long new)136 static inline bool rcu_seq_completed_gp(unsigned long old, unsigned long new)
137 {
138 return ULONG_CMP_LT(old, new & ~RCU_SEQ_STATE_MASK);
139 }
140
141 /*
142 * Has a grace period started since the time the old gp_seq was collected?
143 */
rcu_seq_new_gp(unsigned long old,unsigned long new)144 static inline bool rcu_seq_new_gp(unsigned long old, unsigned long new)
145 {
146 return ULONG_CMP_LT((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK,
147 new);
148 }
149
150 /*
151 * Roughly how many full grace periods have elapsed between the collection
152 * of the two specified grace periods?
153 */
rcu_seq_diff(unsigned long new,unsigned long old)154 static inline unsigned long rcu_seq_diff(unsigned long new, unsigned long old)
155 {
156 unsigned long rnd_diff;
157
158 if (old == new)
159 return 0;
160 /*
161 * Compute the number of grace periods (still shifted up), plus
162 * one if either of new and old is not an exact grace period.
163 */
164 rnd_diff = (new & ~RCU_SEQ_STATE_MASK) -
165 ((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK) +
166 ((new & RCU_SEQ_STATE_MASK) || (old & RCU_SEQ_STATE_MASK));
167 if (ULONG_CMP_GE(RCU_SEQ_STATE_MASK, rnd_diff))
168 return 1; /* Definitely no grace period has elapsed. */
169 return ((rnd_diff - RCU_SEQ_STATE_MASK - 1) >> RCU_SEQ_CTR_SHIFT) + 2;
170 }
171
172 /*
173 * debug_rcu_head_queue()/debug_rcu_head_unqueue() are used internally
174 * by call_rcu() and rcu callback execution, and are therefore not part
175 * of the RCU API. These are in rcupdate.h because they are used by all
176 * RCU implementations.
177 */
178
179 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
180 # define STATE_RCU_HEAD_READY 0
181 # define STATE_RCU_HEAD_QUEUED 1
182
183 extern const struct debug_obj_descr rcuhead_debug_descr;
184
debug_rcu_head_queue(struct rcu_head * head)185 static inline int debug_rcu_head_queue(struct rcu_head *head)
186 {
187 int r1;
188
189 r1 = debug_object_activate(head, &rcuhead_debug_descr);
190 debug_object_active_state(head, &rcuhead_debug_descr,
191 STATE_RCU_HEAD_READY,
192 STATE_RCU_HEAD_QUEUED);
193 return r1;
194 }
195
debug_rcu_head_unqueue(struct rcu_head * head)196 static inline void debug_rcu_head_unqueue(struct rcu_head *head)
197 {
198 debug_object_active_state(head, &rcuhead_debug_descr,
199 STATE_RCU_HEAD_QUEUED,
200 STATE_RCU_HEAD_READY);
201 debug_object_deactivate(head, &rcuhead_debug_descr);
202 }
203 #else /* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
debug_rcu_head_queue(struct rcu_head * head)204 static inline int debug_rcu_head_queue(struct rcu_head *head)
205 {
206 return 0;
207 }
208
debug_rcu_head_unqueue(struct rcu_head * head)209 static inline void debug_rcu_head_unqueue(struct rcu_head *head)
210 {
211 }
212 #endif /* #else !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
213
214 extern int rcu_cpu_stall_suppress_at_boot;
215
rcu_stall_is_suppressed_at_boot(void)216 static inline bool rcu_stall_is_suppressed_at_boot(void)
217 {
218 return rcu_cpu_stall_suppress_at_boot && !rcu_inkernel_boot_has_ended();
219 }
220
221 #ifdef CONFIG_RCU_STALL_COMMON
222
223 extern int rcu_cpu_stall_ftrace_dump;
224 extern int rcu_cpu_stall_suppress;
225 extern int rcu_cpu_stall_timeout;
226 extern int rcu_exp_cpu_stall_timeout;
227 int rcu_jiffies_till_stall_check(void);
228 int rcu_exp_jiffies_till_stall_check(void);
229
rcu_stall_is_suppressed(void)230 static inline bool rcu_stall_is_suppressed(void)
231 {
232 return rcu_stall_is_suppressed_at_boot() || rcu_cpu_stall_suppress;
233 }
234
235 #define rcu_ftrace_dump_stall_suppress() \
236 do { \
237 if (!rcu_cpu_stall_suppress) \
238 rcu_cpu_stall_suppress = 3; \
239 } while (0)
240
241 #define rcu_ftrace_dump_stall_unsuppress() \
242 do { \
243 if (rcu_cpu_stall_suppress == 3) \
244 rcu_cpu_stall_suppress = 0; \
245 } while (0)
246
247 #else /* #endif #ifdef CONFIG_RCU_STALL_COMMON */
248
rcu_stall_is_suppressed(void)249 static inline bool rcu_stall_is_suppressed(void)
250 {
251 return rcu_stall_is_suppressed_at_boot();
252 }
253 #define rcu_ftrace_dump_stall_suppress()
254 #define rcu_ftrace_dump_stall_unsuppress()
255 #endif /* #ifdef CONFIG_RCU_STALL_COMMON */
256
257 /*
258 * Strings used in tracepoints need to be exported via the
259 * tracing system such that tools like perf and trace-cmd can
260 * translate the string address pointers to actual text.
261 */
262 #define TPS(x) tracepoint_string(x)
263
264 /*
265 * Dump the ftrace buffer, but only one time per callsite per boot.
266 */
267 #define rcu_ftrace_dump(oops_dump_mode) \
268 do { \
269 static atomic_t ___rfd_beenhere = ATOMIC_INIT(0); \
270 \
271 if (!atomic_read(&___rfd_beenhere) && \
272 !atomic_xchg(&___rfd_beenhere, 1)) { \
273 tracing_off(); \
274 rcu_ftrace_dump_stall_suppress(); \
275 ftrace_dump(oops_dump_mode); \
276 rcu_ftrace_dump_stall_unsuppress(); \
277 } \
278 } while (0)
279
280 void rcu_early_boot_tests(void);
281 void rcu_test_sync_prims(void);
282
283 /*
284 * This function really isn't for public consumption, but RCU is special in
285 * that context switches can allow the state machine to make progress.
286 */
287 extern void resched_cpu(int cpu);
288
289 #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU)
290
291 #include <linux/rcu_node_tree.h>
292
293 extern int rcu_num_lvls;
294 extern int num_rcu_lvl[];
295 extern int rcu_num_nodes;
296 static bool rcu_fanout_exact;
297 static int rcu_fanout_leaf;
298
299 /*
300 * Compute the per-level fanout, either using the exact fanout specified
301 * or balancing the tree, depending on the rcu_fanout_exact boot parameter.
302 */
rcu_init_levelspread(int * levelspread,const int * levelcnt)303 static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt)
304 {
305 int i;
306
307 for (i = 0; i < RCU_NUM_LVLS; i++)
308 levelspread[i] = INT_MIN;
309 if (rcu_fanout_exact) {
310 levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf;
311 for (i = rcu_num_lvls - 2; i >= 0; i--)
312 levelspread[i] = RCU_FANOUT;
313 } else {
314 int ccur;
315 int cprv;
316
317 cprv = nr_cpu_ids;
318 for (i = rcu_num_lvls - 1; i >= 0; i--) {
319 ccur = levelcnt[i];
320 levelspread[i] = (cprv + ccur - 1) / ccur;
321 cprv = ccur;
322 }
323 }
324 }
325
326 extern void rcu_init_geometry(void);
327
328 /* Returns a pointer to the first leaf rcu_node structure. */
329 #define rcu_first_leaf_node() (rcu_state.level[rcu_num_lvls - 1])
330
331 /* Is this rcu_node a leaf? */
332 #define rcu_is_leaf_node(rnp) ((rnp)->level == rcu_num_lvls - 1)
333
334 /* Is this rcu_node the last leaf? */
335 #define rcu_is_last_leaf_node(rnp) ((rnp) == &rcu_state.node[rcu_num_nodes - 1])
336
337 /*
338 * Do a full breadth-first scan of the {s,}rcu_node structures for the
339 * specified state structure (for SRCU) or the only rcu_state structure
340 * (for RCU).
341 */
342 #define srcu_for_each_node_breadth_first(sp, rnp) \
343 for ((rnp) = &(sp)->node[0]; \
344 (rnp) < &(sp)->node[rcu_num_nodes]; (rnp)++)
345 #define rcu_for_each_node_breadth_first(rnp) \
346 srcu_for_each_node_breadth_first(&rcu_state, rnp)
347
348 /*
349 * Scan the leaves of the rcu_node hierarchy for the rcu_state structure.
350 * Note that if there is a singleton rcu_node tree with but one rcu_node
351 * structure, this loop -will- visit the rcu_node structure. It is still
352 * a leaf node, even if it is also the root node.
353 */
354 #define rcu_for_each_leaf_node(rnp) \
355 for ((rnp) = rcu_first_leaf_node(); \
356 (rnp) < &rcu_state.node[rcu_num_nodes]; (rnp)++)
357
358 /*
359 * Iterate over all possible CPUs in a leaf RCU node.
360 */
361 #define for_each_leaf_node_possible_cpu(rnp, cpu) \
362 for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \
363 (cpu) = cpumask_next((rnp)->grplo - 1, cpu_possible_mask); \
364 (cpu) <= rnp->grphi; \
365 (cpu) = cpumask_next((cpu), cpu_possible_mask))
366
367 /*
368 * Iterate over all CPUs in a leaf RCU node's specified mask.
369 */
370 #define rcu_find_next_bit(rnp, cpu, mask) \
371 ((rnp)->grplo + find_next_bit(&(mask), BITS_PER_LONG, (cpu)))
372 #define for_each_leaf_node_cpu_mask(rnp, cpu, mask) \
373 for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \
374 (cpu) = rcu_find_next_bit((rnp), 0, (mask)); \
375 (cpu) <= rnp->grphi; \
376 (cpu) = rcu_find_next_bit((rnp), (cpu) + 1 - (rnp->grplo), (mask)))
377
378 /*
379 * Wrappers for the rcu_node::lock acquire and release.
380 *
381 * Because the rcu_nodes form a tree, the tree traversal locking will observe
382 * different lock values, this in turn means that an UNLOCK of one level
383 * followed by a LOCK of another level does not imply a full memory barrier;
384 * and most importantly transitivity is lost.
385 *
386 * In order to restore full ordering between tree levels, augment the regular
387 * lock acquire functions with smp_mb__after_unlock_lock().
388 *
389 * As ->lock of struct rcu_node is a __private field, therefore one should use
390 * these wrappers rather than directly call raw_spin_{lock,unlock}* on ->lock.
391 */
392 #define raw_spin_lock_rcu_node(p) \
393 do { \
394 raw_spin_lock(&ACCESS_PRIVATE(p, lock)); \
395 smp_mb__after_unlock_lock(); \
396 } while (0)
397
398 #define raw_spin_unlock_rcu_node(p) \
399 do { \
400 lockdep_assert_irqs_disabled(); \
401 raw_spin_unlock(&ACCESS_PRIVATE(p, lock)); \
402 } while (0)
403
404 #define raw_spin_lock_irq_rcu_node(p) \
405 do { \
406 raw_spin_lock_irq(&ACCESS_PRIVATE(p, lock)); \
407 smp_mb__after_unlock_lock(); \
408 } while (0)
409
410 #define raw_spin_unlock_irq_rcu_node(p) \
411 do { \
412 lockdep_assert_irqs_disabled(); \
413 raw_spin_unlock_irq(&ACCESS_PRIVATE(p, lock)); \
414 } while (0)
415
416 #define raw_spin_lock_irqsave_rcu_node(p, flags) \
417 do { \
418 raw_spin_lock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \
419 smp_mb__after_unlock_lock(); \
420 } while (0)
421
422 #define raw_spin_unlock_irqrestore_rcu_node(p, flags) \
423 do { \
424 lockdep_assert_irqs_disabled(); \
425 raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags); \
426 } while (0)
427
428 #define raw_spin_trylock_rcu_node(p) \
429 ({ \
430 bool ___locked = raw_spin_trylock(&ACCESS_PRIVATE(p, lock)); \
431 \
432 if (___locked) \
433 smp_mb__after_unlock_lock(); \
434 ___locked; \
435 })
436
437 #define raw_lockdep_assert_held_rcu_node(p) \
438 lockdep_assert_held(&ACCESS_PRIVATE(p, lock))
439
440 #endif /* #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) */
441
442 #ifdef CONFIG_TINY_RCU
443 /* Tiny RCU doesn't expedite, as its purpose in life is instead to be tiny. */
rcu_gp_is_normal(void)444 static inline bool rcu_gp_is_normal(void) { return true; }
rcu_gp_is_expedited(void)445 static inline bool rcu_gp_is_expedited(void) { return false; }
rcu_expedite_gp(void)446 static inline void rcu_expedite_gp(void) { }
rcu_unexpedite_gp(void)447 static inline void rcu_unexpedite_gp(void) { }
rcu_request_urgent_qs_task(struct task_struct * t)448 static inline void rcu_request_urgent_qs_task(struct task_struct *t) { }
449 #else /* #ifdef CONFIG_TINY_RCU */
450 bool rcu_gp_is_normal(void); /* Internal RCU use. */
451 bool rcu_gp_is_expedited(void); /* Internal RCU use. */
452 void rcu_expedite_gp(void);
453 void rcu_unexpedite_gp(void);
454 void rcupdate_announce_bootup_oddness(void);
455 #ifdef CONFIG_TASKS_RCU_GENERIC
456 void show_rcu_tasks_gp_kthreads(void);
457 #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
show_rcu_tasks_gp_kthreads(void)458 static inline void show_rcu_tasks_gp_kthreads(void) {}
459 #endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */
460 void rcu_request_urgent_qs_task(struct task_struct *t);
461 #endif /* #else #ifdef CONFIG_TINY_RCU */
462
463 #define RCU_SCHEDULER_INACTIVE 0
464 #define RCU_SCHEDULER_INIT 1
465 #define RCU_SCHEDULER_RUNNING 2
466
467 enum rcutorture_type {
468 RCU_FLAVOR,
469 RCU_TASKS_FLAVOR,
470 RCU_TASKS_RUDE_FLAVOR,
471 RCU_TASKS_TRACING_FLAVOR,
472 RCU_TRIVIAL_FLAVOR,
473 SRCU_FLAVOR,
474 INVALID_RCU_FLAVOR
475 };
476
477 #if defined(CONFIG_TREE_RCU)
478 void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,
479 unsigned long *gp_seq);
480 void do_trace_rcu_torture_read(const char *rcutorturename,
481 struct rcu_head *rhp,
482 unsigned long secs,
483 unsigned long c_old,
484 unsigned long c);
485 void rcu_gp_set_torture_wait(int duration);
486 #else
rcutorture_get_gp_data(enum rcutorture_type test_type,int * flags,unsigned long * gp_seq)487 static inline void rcutorture_get_gp_data(enum rcutorture_type test_type,
488 int *flags, unsigned long *gp_seq)
489 {
490 *flags = 0;
491 *gp_seq = 0;
492 }
493 #ifdef CONFIG_RCU_TRACE
494 void do_trace_rcu_torture_read(const char *rcutorturename,
495 struct rcu_head *rhp,
496 unsigned long secs,
497 unsigned long c_old,
498 unsigned long c);
499 #else
500 #define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
501 do { } while (0)
502 #endif
rcu_gp_set_torture_wait(int duration)503 static inline void rcu_gp_set_torture_wait(int duration) { }
504 #endif
505
506 #if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST)
507 long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask);
508 #endif
509
510 #ifdef CONFIG_TINY_SRCU
511
srcutorture_get_gp_data(enum rcutorture_type test_type,struct srcu_struct * sp,int * flags,unsigned long * gp_seq)512 static inline void srcutorture_get_gp_data(enum rcutorture_type test_type,
513 struct srcu_struct *sp, int *flags,
514 unsigned long *gp_seq)
515 {
516 if (test_type != SRCU_FLAVOR)
517 return;
518 *flags = 0;
519 *gp_seq = sp->srcu_idx;
520 }
521
522 #elif defined(CONFIG_TREE_SRCU)
523
524 void srcutorture_get_gp_data(enum rcutorture_type test_type,
525 struct srcu_struct *sp, int *flags,
526 unsigned long *gp_seq);
527
528 #endif
529
530 #ifdef CONFIG_TINY_RCU
rcu_dynticks_zero_in_eqs(int cpu,int * vp)531 static inline bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) { return false; }
rcu_get_gp_seq(void)532 static inline unsigned long rcu_get_gp_seq(void) { return 0; }
rcu_exp_batches_completed(void)533 static inline unsigned long rcu_exp_batches_completed(void) { return 0; }
534 static inline unsigned long
srcu_batches_completed(struct srcu_struct * sp)535 srcu_batches_completed(struct srcu_struct *sp) { return 0; }
rcu_force_quiescent_state(void)536 static inline void rcu_force_quiescent_state(void) { }
rcu_check_boost_fail(unsigned long gp_state,int * cpup)537 static inline bool rcu_check_boost_fail(unsigned long gp_state, int *cpup) { return true; }
show_rcu_gp_kthreads(void)538 static inline void show_rcu_gp_kthreads(void) { }
rcu_get_gp_kthreads_prio(void)539 static inline int rcu_get_gp_kthreads_prio(void) { return 0; }
rcu_fwd_progress_check(unsigned long j)540 static inline void rcu_fwd_progress_check(unsigned long j) { }
rcu_gp_slow_register(atomic_t * rgssp)541 static inline void rcu_gp_slow_register(atomic_t *rgssp) { }
rcu_gp_slow_unregister(atomic_t * rgssp)542 static inline void rcu_gp_slow_unregister(atomic_t *rgssp) { }
543 #else /* #ifdef CONFIG_TINY_RCU */
544 bool rcu_dynticks_zero_in_eqs(int cpu, int *vp);
545 unsigned long rcu_get_gp_seq(void);
546 unsigned long rcu_exp_batches_completed(void);
547 unsigned long srcu_batches_completed(struct srcu_struct *sp);
548 bool rcu_check_boost_fail(unsigned long gp_state, int *cpup);
549 void show_rcu_gp_kthreads(void);
550 int rcu_get_gp_kthreads_prio(void);
551 void rcu_fwd_progress_check(unsigned long j);
552 void rcu_force_quiescent_state(void);
553 extern struct workqueue_struct *rcu_gp_wq;
554 #ifdef CONFIG_RCU_EXP_KTHREAD
555 extern struct kthread_worker *rcu_exp_gp_kworker;
556 extern struct kthread_worker *rcu_exp_par_gp_kworker;
557 #else /* !CONFIG_RCU_EXP_KTHREAD */
558 extern struct workqueue_struct *rcu_par_gp_wq;
559 #endif /* CONFIG_RCU_EXP_KTHREAD */
560 void rcu_gp_slow_register(atomic_t *rgssp);
561 void rcu_gp_slow_unregister(atomic_t *rgssp);
562 #endif /* #else #ifdef CONFIG_TINY_RCU */
563
564 #ifdef CONFIG_RCU_NOCB_CPU
565 void rcu_bind_current_to_nocb(void);
566 #else
rcu_bind_current_to_nocb(void)567 static inline void rcu_bind_current_to_nocb(void) { }
568 #endif
569
570 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RCU)
571 void show_rcu_tasks_classic_gp_kthread(void);
572 #else
show_rcu_tasks_classic_gp_kthread(void)573 static inline void show_rcu_tasks_classic_gp_kthread(void) {}
574 #endif
575 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RUDE_RCU)
576 void show_rcu_tasks_rude_gp_kthread(void);
577 #else
show_rcu_tasks_rude_gp_kthread(void)578 static inline void show_rcu_tasks_rude_gp_kthread(void) {}
579 #endif
580 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_TRACE_RCU)
581 void show_rcu_tasks_trace_gp_kthread(void);
582 #else
show_rcu_tasks_trace_gp_kthread(void)583 static inline void show_rcu_tasks_trace_gp_kthread(void) {}
584 #endif
585
586 #endif /* __LINUX_RCU_H */
587