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10#ifndef __LINUX_RCU_H
11#define __LINUX_RCU_H
12
13#include <trace/events/rcu.h>
14
15
16#define DYNTICK_IRQ_NONIDLE ((LONG_MAX / 2) + 1)
17
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21
22
23#define RCU_SEQ_CTR_SHIFT 2
24#define RCU_SEQ_STATE_MASK ((1 << RCU_SEQ_CTR_SHIFT) - 1)
25
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28
29
30static inline unsigned long rcu_seq_ctr(unsigned long s)
31{
32 return s >> RCU_SEQ_CTR_SHIFT;
33}
34
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36
37
38
39static inline int rcu_seq_state(unsigned long s)
40{
41 return s & RCU_SEQ_STATE_MASK;
42}
43
44
45
46
47
48static inline void rcu_seq_set_state(unsigned long *sp, int newstate)
49{
50 WARN_ON_ONCE(newstate & ~RCU_SEQ_STATE_MASK);
51 WRITE_ONCE(*sp, (*sp & ~RCU_SEQ_STATE_MASK) + newstate);
52}
53
54
55static inline void rcu_seq_start(unsigned long *sp)
56{
57 WRITE_ONCE(*sp, *sp + 1);
58 smp_mb();
59 WARN_ON_ONCE(rcu_seq_state(*sp) != 1);
60}
61
62
63static inline unsigned long rcu_seq_endval(unsigned long *sp)
64{
65 return (*sp | RCU_SEQ_STATE_MASK) + 1;
66}
67
68
69static inline void rcu_seq_end(unsigned long *sp)
70{
71 smp_mb();
72 WARN_ON_ONCE(!rcu_seq_state(*sp));
73 WRITE_ONCE(*sp, rcu_seq_endval(sp));
74}
75
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86
87static inline unsigned long rcu_seq_snap(unsigned long *sp)
88{
89 unsigned long s;
90
91 s = (READ_ONCE(*sp) + 2 * RCU_SEQ_STATE_MASK + 1) & ~RCU_SEQ_STATE_MASK;
92 smp_mb();
93 return s;
94}
95
96
97static inline unsigned long rcu_seq_current(unsigned long *sp)
98{
99 return READ_ONCE(*sp);
100}
101
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105
106static inline bool rcu_seq_started(unsigned long *sp, unsigned long s)
107{
108 return ULONG_CMP_LT((s - 1) & ~RCU_SEQ_STATE_MASK, READ_ONCE(*sp));
109}
110
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114
115static inline bool rcu_seq_done(unsigned long *sp, unsigned long s)
116{
117 return ULONG_CMP_GE(READ_ONCE(*sp), s);
118}
119
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121
122
123static inline bool rcu_seq_completed_gp(unsigned long old, unsigned long new)
124{
125 return ULONG_CMP_LT(old, new & ~RCU_SEQ_STATE_MASK);
126}
127
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129
130
131static inline bool rcu_seq_new_gp(unsigned long old, unsigned long new)
132{
133 return ULONG_CMP_LT((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK,
134 new);
135}
136
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139
140
141static inline unsigned long rcu_seq_diff(unsigned long new, unsigned long old)
142{
143 unsigned long rnd_diff;
144
145 if (old == new)
146 return 0;
147
148
149
150
151 rnd_diff = (new & ~RCU_SEQ_STATE_MASK) -
152 ((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK) +
153 ((new & RCU_SEQ_STATE_MASK) || (old & RCU_SEQ_STATE_MASK));
154 if (ULONG_CMP_GE(RCU_SEQ_STATE_MASK, rnd_diff))
155 return 1;
156 return ((rnd_diff - RCU_SEQ_STATE_MASK - 1) >> RCU_SEQ_CTR_SHIFT) + 2;
157}
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165
166#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
167# define STATE_RCU_HEAD_READY 0
168# define STATE_RCU_HEAD_QUEUED 1
169
170extern const struct debug_obj_descr rcuhead_debug_descr;
171
172static inline int debug_rcu_head_queue(struct rcu_head *head)
173{
174 int r1;
175
176 r1 = debug_object_activate(head, &rcuhead_debug_descr);
177 debug_object_active_state(head, &rcuhead_debug_descr,
178 STATE_RCU_HEAD_READY,
179 STATE_RCU_HEAD_QUEUED);
180 return r1;
181}
182
183static inline void debug_rcu_head_unqueue(struct rcu_head *head)
184{
185 debug_object_active_state(head, &rcuhead_debug_descr,
186 STATE_RCU_HEAD_QUEUED,
187 STATE_RCU_HEAD_READY);
188 debug_object_deactivate(head, &rcuhead_debug_descr);
189}
190#else
191static inline int debug_rcu_head_queue(struct rcu_head *head)
192{
193 return 0;
194}
195
196static inline void debug_rcu_head_unqueue(struct rcu_head *head)
197{
198}
199#endif
200
201extern int rcu_cpu_stall_suppress_at_boot;
202
203static inline bool rcu_stall_is_suppressed_at_boot(void)
204{
205 return rcu_cpu_stall_suppress_at_boot && !rcu_inkernel_boot_has_ended();
206}
207
208#ifdef CONFIG_RCU_STALL_COMMON
209
210extern int rcu_cpu_stall_ftrace_dump;
211extern int rcu_cpu_stall_suppress;
212extern int rcu_cpu_stall_timeout;
213int rcu_jiffies_till_stall_check(void);
214
215static inline bool rcu_stall_is_suppressed(void)
216{
217 return rcu_stall_is_suppressed_at_boot() || rcu_cpu_stall_suppress;
218}
219
220#define rcu_ftrace_dump_stall_suppress() \
221do { \
222 if (!rcu_cpu_stall_suppress) \
223 rcu_cpu_stall_suppress = 3; \
224} while (0)
225
226#define rcu_ftrace_dump_stall_unsuppress() \
227do { \
228 if (rcu_cpu_stall_suppress == 3) \
229 rcu_cpu_stall_suppress = 0; \
230} while (0)
231
232#else
233
234static inline bool rcu_stall_is_suppressed(void)
235{
236 return rcu_stall_is_suppressed_at_boot();
237}
238#define rcu_ftrace_dump_stall_suppress()
239#define rcu_ftrace_dump_stall_unsuppress()
240#endif
241
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245
246
247#define TPS(x) tracepoint_string(x)
248
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251
252#define rcu_ftrace_dump(oops_dump_mode) \
253do { \
254 static atomic_t ___rfd_beenhere = ATOMIC_INIT(0); \
255 \
256 if (!atomic_read(&___rfd_beenhere) && \
257 !atomic_xchg(&___rfd_beenhere, 1)) { \
258 tracing_off(); \
259 rcu_ftrace_dump_stall_suppress(); \
260 ftrace_dump(oops_dump_mode); \
261 rcu_ftrace_dump_stall_unsuppress(); \
262 } \
263} while (0)
264
265void rcu_early_boot_tests(void);
266void rcu_test_sync_prims(void);
267
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270
271
272extern void resched_cpu(int cpu);
273
274#if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU)
275
276#include <linux/rcu_node_tree.h>
277
278extern int rcu_num_lvls;
279extern int num_rcu_lvl[];
280extern int rcu_num_nodes;
281static bool rcu_fanout_exact;
282static int rcu_fanout_leaf;
283
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287
288static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt)
289{
290 int i;
291
292 for (i = 0; i < RCU_NUM_LVLS; i++)
293 levelspread[i] = INT_MIN;
294 if (rcu_fanout_exact) {
295 levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf;
296 for (i = rcu_num_lvls - 2; i >= 0; i--)
297 levelspread[i] = RCU_FANOUT;
298 } else {
299 int ccur;
300 int cprv;
301
302 cprv = nr_cpu_ids;
303 for (i = rcu_num_lvls - 1; i >= 0; i--) {
304 ccur = levelcnt[i];
305 levelspread[i] = (cprv + ccur - 1) / ccur;
306 cprv = ccur;
307 }
308 }
309}
310
311extern void rcu_init_geometry(void);
312
313
314#define rcu_first_leaf_node() (rcu_state.level[rcu_num_lvls - 1])
315
316
317#define rcu_is_leaf_node(rnp) ((rnp)->level == rcu_num_lvls - 1)
318
319
320#define rcu_is_last_leaf_node(rnp) ((rnp) == &rcu_state.node[rcu_num_nodes - 1])
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327#define srcu_for_each_node_breadth_first(sp, rnp) \
328 for ((rnp) = &(sp)->node[0]; \
329 (rnp) < &(sp)->node[rcu_num_nodes]; (rnp)++)
330#define rcu_for_each_node_breadth_first(rnp) \
331 srcu_for_each_node_breadth_first(&rcu_state, rnp)
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338
339#define rcu_for_each_leaf_node(rnp) \
340 for ((rnp) = rcu_first_leaf_node(); \
341 (rnp) < &rcu_state.node[rcu_num_nodes]; (rnp)++)
342
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345
346#define for_each_leaf_node_possible_cpu(rnp, cpu) \
347 for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \
348 (cpu) = cpumask_next((rnp)->grplo - 1, cpu_possible_mask); \
349 (cpu) <= rnp->grphi; \
350 (cpu) = cpumask_next((cpu), cpu_possible_mask))
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354
355#define rcu_find_next_bit(rnp, cpu, mask) \
356 ((rnp)->grplo + find_next_bit(&(mask), BITS_PER_LONG, (cpu)))
357#define for_each_leaf_node_cpu_mask(rnp, cpu, mask) \
358 for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \
359 (cpu) = rcu_find_next_bit((rnp), 0, (mask)); \
360 (cpu) <= rnp->grphi; \
361 (cpu) = rcu_find_next_bit((rnp), (cpu) + 1 - (rnp->grplo), (mask)))
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377#define raw_spin_lock_rcu_node(p) \
378do { \
379 raw_spin_lock(&ACCESS_PRIVATE(p, lock)); \
380 smp_mb__after_unlock_lock(); \
381} while (0)
382
383#define raw_spin_unlock_rcu_node(p) \
384do { \
385 lockdep_assert_irqs_disabled(); \
386 raw_spin_unlock(&ACCESS_PRIVATE(p, lock)); \
387} while (0)
388
389#define raw_spin_lock_irq_rcu_node(p) \
390do { \
391 raw_spin_lock_irq(&ACCESS_PRIVATE(p, lock)); \
392 smp_mb__after_unlock_lock(); \
393} while (0)
394
395#define raw_spin_unlock_irq_rcu_node(p) \
396do { \
397 lockdep_assert_irqs_disabled(); \
398 raw_spin_unlock_irq(&ACCESS_PRIVATE(p, lock)); \
399} while (0)
400
401#define raw_spin_lock_irqsave_rcu_node(p, flags) \
402do { \
403 raw_spin_lock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \
404 smp_mb__after_unlock_lock(); \
405} while (0)
406
407#define raw_spin_unlock_irqrestore_rcu_node(p, flags) \
408do { \
409 lockdep_assert_irqs_disabled(); \
410 raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags); \
411} while (0)
412
413#define raw_spin_trylock_rcu_node(p) \
414({ \
415 bool ___locked = raw_spin_trylock(&ACCESS_PRIVATE(p, lock)); \
416 \
417 if (___locked) \
418 smp_mb__after_unlock_lock(); \
419 ___locked; \
420})
421
422#define raw_lockdep_assert_held_rcu_node(p) \
423 lockdep_assert_held(&ACCESS_PRIVATE(p, lock))
424
425#endif
426
427#ifdef CONFIG_TINY_RCU
428
429static inline bool rcu_gp_is_normal(void) { return true; }
430static inline bool rcu_gp_is_expedited(void) { return false; }
431static inline void rcu_expedite_gp(void) { }
432static inline void rcu_unexpedite_gp(void) { }
433static inline void rcu_request_urgent_qs_task(struct task_struct *t) { }
434#else
435bool rcu_gp_is_normal(void);
436bool rcu_gp_is_expedited(void);
437void rcu_expedite_gp(void);
438void rcu_unexpedite_gp(void);
439void rcupdate_announce_bootup_oddness(void);
440#ifdef CONFIG_TASKS_RCU_GENERIC
441void show_rcu_tasks_gp_kthreads(void);
442#else
443static inline void show_rcu_tasks_gp_kthreads(void) {}
444#endif
445void rcu_request_urgent_qs_task(struct task_struct *t);
446#endif
447
448#define RCU_SCHEDULER_INACTIVE 0
449#define RCU_SCHEDULER_INIT 1
450#define RCU_SCHEDULER_RUNNING 2
451
452enum rcutorture_type {
453 RCU_FLAVOR,
454 RCU_TASKS_FLAVOR,
455 RCU_TASKS_RUDE_FLAVOR,
456 RCU_TASKS_TRACING_FLAVOR,
457 RCU_TRIVIAL_FLAVOR,
458 SRCU_FLAVOR,
459 INVALID_RCU_FLAVOR
460};
461
462#if defined(CONFIG_TREE_RCU)
463void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,
464 unsigned long *gp_seq);
465void do_trace_rcu_torture_read(const char *rcutorturename,
466 struct rcu_head *rhp,
467 unsigned long secs,
468 unsigned long c_old,
469 unsigned long c);
470void rcu_gp_set_torture_wait(int duration);
471#else
472static inline void rcutorture_get_gp_data(enum rcutorture_type test_type,
473 int *flags, unsigned long *gp_seq)
474{
475 *flags = 0;
476 *gp_seq = 0;
477}
478#ifdef CONFIG_RCU_TRACE
479void do_trace_rcu_torture_read(const char *rcutorturename,
480 struct rcu_head *rhp,
481 unsigned long secs,
482 unsigned long c_old,
483 unsigned long c);
484#else
485#define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
486 do { } while (0)
487#endif
488static inline void rcu_gp_set_torture_wait(int duration) { }
489#endif
490
491#if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST)
492long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask);
493#endif
494
495#ifdef CONFIG_TINY_SRCU
496
497static inline void srcutorture_get_gp_data(enum rcutorture_type test_type,
498 struct srcu_struct *sp, int *flags,
499 unsigned long *gp_seq)
500{
501 if (test_type != SRCU_FLAVOR)
502 return;
503 *flags = 0;
504 *gp_seq = sp->srcu_idx;
505}
506
507#elif defined(CONFIG_TREE_SRCU)
508
509void srcutorture_get_gp_data(enum rcutorture_type test_type,
510 struct srcu_struct *sp, int *flags,
511 unsigned long *gp_seq);
512
513#endif
514
515#ifdef CONFIG_TINY_RCU
516static inline bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) { return false; }
517static inline unsigned long rcu_get_gp_seq(void) { return 0; }
518static inline unsigned long rcu_exp_batches_completed(void) { return 0; }
519static inline unsigned long
520srcu_batches_completed(struct srcu_struct *sp) { return 0; }
521static inline void rcu_force_quiescent_state(void) { }
522static inline bool rcu_check_boost_fail(unsigned long gp_state, int *cpup) { return true; }
523static inline void show_rcu_gp_kthreads(void) { }
524static inline int rcu_get_gp_kthreads_prio(void) { return 0; }
525static inline void rcu_fwd_progress_check(unsigned long j) { }
526#else
527bool rcu_dynticks_zero_in_eqs(int cpu, int *vp);
528unsigned long rcu_get_gp_seq(void);
529unsigned long rcu_exp_batches_completed(void);
530unsigned long srcu_batches_completed(struct srcu_struct *sp);
531bool rcu_check_boost_fail(unsigned long gp_state, int *cpup);
532void show_rcu_gp_kthreads(void);
533int rcu_get_gp_kthreads_prio(void);
534void rcu_fwd_progress_check(unsigned long j);
535void rcu_force_quiescent_state(void);
536extern struct workqueue_struct *rcu_gp_wq;
537extern struct workqueue_struct *rcu_par_gp_wq;
538#endif
539
540#ifdef CONFIG_RCU_NOCB_CPU
541bool rcu_is_nocb_cpu(int cpu);
542void rcu_bind_current_to_nocb(void);
543#else
544static inline bool rcu_is_nocb_cpu(int cpu) { return false; }
545static inline void rcu_bind_current_to_nocb(void) { }
546#endif
547
548#if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RCU)
549void show_rcu_tasks_classic_gp_kthread(void);
550#else
551static inline void show_rcu_tasks_classic_gp_kthread(void) {}
552#endif
553#if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RUDE_RCU)
554void show_rcu_tasks_rude_gp_kthread(void);
555#else
556static inline void show_rcu_tasks_rude_gp_kthread(void) {}
557#endif
558#if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_TRACE_RCU)
559void show_rcu_tasks_trace_gp_kthread(void);
560#else
561static inline void show_rcu_tasks_trace_gp_kthread(void) {}
562#endif
563
564#endif
565