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 <linux/slab.h> 14#include <trace/events/rcu.h> 15 16/* 17 * Grace-period counter management. 18 * 19 * The two least significant bits contain the control flags. 20 * The most significant bits contain the grace-period sequence counter. 21 * 22 * When both control flags are zero, no grace period is in progress. 23 * When either bit is non-zero, a grace period has started and is in 24 * progress. When the grace period completes, the control flags are reset 25 * to 0 and the grace-period sequence counter is incremented. 26 * 27 * However some specific RCU usages make use of custom values. 28 * 29 * SRCU special control values: 30 * 31 * SRCU_SNP_INIT_SEQ : Invalid/init value set when SRCU node 32 * is initialized. 33 * 34 * SRCU_STATE_IDLE : No SRCU gp is in progress 35 * 36 * SRCU_STATE_SCAN1 : State set by rcu_seq_start(). Indicates 37 * we are scanning the readers on the slot 38 * defined as inactive (there might well 39 * be pending readers that will use that 40 * index, but their number is bounded). 41 * 42 * SRCU_STATE_SCAN2 : State set manually via rcu_seq_set_state() 43 * Indicates we are flipping the readers 44 * index and then scanning the readers on the 45 * slot newly designated as inactive (again, 46 * the number of pending readers that will use 47 * this inactive index is bounded). 48 * 49 * RCU polled GP special control value: 50 * 51 * RCU_GET_STATE_COMPLETED : State value indicating an already-completed 52 * polled GP has completed. This value covers 53 * both the state and the counter of the 54 * grace-period sequence number. 55 */ 56 57#define RCU_SEQ_CTR_SHIFT 2 58#define RCU_SEQ_STATE_MASK ((1 << RCU_SEQ_CTR_SHIFT) - 1) 59 60/* Low-order bit definition for polled grace-period APIs. */ 61#define RCU_GET_STATE_COMPLETED 0x1 62 63extern int sysctl_sched_rt_runtime; 64 65/* 66 * Return the counter portion of a sequence number previously returned 67 * by rcu_seq_snap() or rcu_seq_current(). 68 */ 69static inline unsigned long rcu_seq_ctr(unsigned long s) 70{ 71 return s >> RCU_SEQ_CTR_SHIFT; 72} 73 74/* 75 * Return the state portion of a sequence number previously returned 76 * by rcu_seq_snap() or rcu_seq_current(). 77 */ 78static inline int rcu_seq_state(unsigned long s) 79{ 80 return s & RCU_SEQ_STATE_MASK; 81} 82 83/* 84 * Set the state portion of the pointed-to sequence number. 85 * The caller is responsible for preventing conflicting updates. 86 */ 87static inline void rcu_seq_set_state(unsigned long *sp, int newstate) 88{ 89 WARN_ON_ONCE(newstate & ~RCU_SEQ_STATE_MASK); 90 WRITE_ONCE(*sp, (*sp & ~RCU_SEQ_STATE_MASK) + newstate); 91} 92 93/* Adjust sequence number for start of update-side operation. */ 94static inline void rcu_seq_start(unsigned long *sp) 95{ 96 WRITE_ONCE(*sp, *sp + 1); 97 smp_mb(); /* Ensure update-side operation after counter increment. */ 98 WARN_ON_ONCE(rcu_seq_state(*sp) != 1); 99} 100 101/* Compute the end-of-grace-period value for the specified sequence number. */ 102static inline unsigned long rcu_seq_endval(unsigned long *sp) 103{ 104 return (*sp | RCU_SEQ_STATE_MASK) + 1; 105} 106 107/* Adjust sequence number for end of update-side operation. */ 108static inline void rcu_seq_end(unsigned long *sp) 109{ 110 smp_mb(); /* Ensure update-side operation before counter increment. */ 111 WARN_ON_ONCE(!rcu_seq_state(*sp)); 112 WRITE_ONCE(*sp, rcu_seq_endval(sp)); 113} 114 115/* 116 * rcu_seq_snap - Take a snapshot of the update side's sequence number. 117 * 118 * This function returns the earliest value of the grace-period sequence number 119 * that will indicate that a full grace period has elapsed since the current 120 * time. Once the grace-period sequence number has reached this value, it will 121 * be safe to invoke all callbacks that have been registered prior to the 122 * current time. This value is the current grace-period number plus two to the 123 * power of the number of low-order bits reserved for state, then rounded up to 124 * the next value in which the state bits are all zero. 125 */ 126static inline unsigned long rcu_seq_snap(unsigned long *sp) 127{ 128 unsigned long s; 129 130 s = (READ_ONCE(*sp) + 2 * RCU_SEQ_STATE_MASK + 1) & ~RCU_SEQ_STATE_MASK; 131 smp_mb(); /* Above access must not bleed into critical section. */ 132 return s; 133} 134 135/* Return the current value the update side's sequence number, no ordering. */ 136static inline unsigned long rcu_seq_current(unsigned long *sp) 137{ 138 return READ_ONCE(*sp); 139} 140 141/* 142 * Given a snapshot from rcu_seq_snap(), determine whether or not the 143 * corresponding update-side operation has started. 144 */ 145static inline bool rcu_seq_started(unsigned long *sp, unsigned long s) 146{ 147 return ULONG_CMP_LT((s - 1) & ~RCU_SEQ_STATE_MASK, READ_ONCE(*sp)); 148} 149 150/* 151 * Given a snapshot from rcu_seq_snap(), determine whether or not a 152 * full update-side operation has occurred. 153 */ 154static inline bool rcu_seq_done(unsigned long *sp, unsigned long s) 155{ 156 return ULONG_CMP_GE(READ_ONCE(*sp), s); 157} 158 159/* 160 * Given a snapshot from rcu_seq_snap(), determine whether or not a 161 * full update-side operation has occurred, but do not allow the 162 * (ULONG_MAX / 2) safety-factor/guard-band. 163 */ 164static inline bool rcu_seq_done_exact(unsigned long *sp, unsigned long s) 165{ 166 unsigned long cur_s = READ_ONCE(*sp); 167 168 return ULONG_CMP_GE(cur_s, s) || ULONG_CMP_LT(cur_s, s - (2 * RCU_SEQ_STATE_MASK + 1)); 169} 170 171/* 172 * Has a grace period completed since the time the old gp_seq was collected? 173 */ 174static inline bool rcu_seq_completed_gp(unsigned long old, unsigned long new) 175{ 176 return ULONG_CMP_LT(old, new & ~RCU_SEQ_STATE_MASK); 177} 178 179/* 180 * Has a grace period started since the time the old gp_seq was collected? 181 */ 182static inline bool rcu_seq_new_gp(unsigned long old, unsigned long new) 183{ 184 return ULONG_CMP_LT((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK, 185 new); 186} 187 188/* 189 * Roughly how many full grace periods have elapsed between the collection 190 * of the two specified grace periods? 191 */ 192static inline unsigned long rcu_seq_diff(unsigned long new, unsigned long old) 193{ 194 unsigned long rnd_diff; 195 196 if (old == new) 197 return 0; 198 /* 199 * Compute the number of grace periods (still shifted up), plus 200 * one if either of new and old is not an exact grace period. 201 */ 202 rnd_diff = (new & ~RCU_SEQ_STATE_MASK) - 203 ((old + RCU_SEQ_STATE_MASK) & ~RCU_SEQ_STATE_MASK) + 204 ((new & RCU_SEQ_STATE_MASK) || (old & RCU_SEQ_STATE_MASK)); 205 if (ULONG_CMP_GE(RCU_SEQ_STATE_MASK, rnd_diff)) 206 return 1; /* Definitely no grace period has elapsed. */ 207 return ((rnd_diff - RCU_SEQ_STATE_MASK - 1) >> RCU_SEQ_CTR_SHIFT) + 2; 208} 209 210/* 211 * debug_rcu_head_queue()/debug_rcu_head_unqueue() are used internally 212 * by call_rcu() and rcu callback execution, and are therefore not part 213 * of the RCU API. These are in rcupdate.h because they are used by all 214 * RCU implementations. 215 */ 216 217#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD 218# define STATE_RCU_HEAD_READY 0 219# define STATE_RCU_HEAD_QUEUED 1 220 221extern const struct debug_obj_descr rcuhead_debug_descr; 222 223static inline int debug_rcu_head_queue(struct rcu_head *head) 224{ 225 int r1; 226 227 r1 = debug_object_activate(head, &rcuhead_debug_descr); 228 debug_object_active_state(head, &rcuhead_debug_descr, 229 STATE_RCU_HEAD_READY, 230 STATE_RCU_HEAD_QUEUED); 231 return r1; 232} 233 234static inline void debug_rcu_head_unqueue(struct rcu_head *head) 235{ 236 debug_object_active_state(head, &rcuhead_debug_descr, 237 STATE_RCU_HEAD_QUEUED, 238 STATE_RCU_HEAD_READY); 239 debug_object_deactivate(head, &rcuhead_debug_descr); 240} 241#else /* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */ 242static inline int debug_rcu_head_queue(struct rcu_head *head) 243{ 244 return 0; 245} 246 247static inline void debug_rcu_head_unqueue(struct rcu_head *head) 248{ 249} 250#endif /* #else !CONFIG_DEBUG_OBJECTS_RCU_HEAD */ 251 252static inline void debug_rcu_head_callback(struct rcu_head *rhp) 253{ 254 if (unlikely(!rhp->func)) 255 kmem_dump_obj(rhp); 256} 257 258extern int rcu_cpu_stall_suppress_at_boot; 259 260static inline bool rcu_stall_is_suppressed_at_boot(void) 261{ 262 return rcu_cpu_stall_suppress_at_boot && !rcu_inkernel_boot_has_ended(); 263} 264 265extern int rcu_cpu_stall_notifiers; 266 267#ifdef CONFIG_RCU_STALL_COMMON 268 269extern int rcu_cpu_stall_ftrace_dump; 270extern int rcu_cpu_stall_suppress; 271extern int rcu_cpu_stall_timeout; 272extern int rcu_exp_cpu_stall_timeout; 273extern int rcu_cpu_stall_cputime; 274extern bool rcu_exp_stall_task_details __read_mostly; 275int rcu_jiffies_till_stall_check(void); 276int rcu_exp_jiffies_till_stall_check(void); 277 278static inline bool rcu_stall_is_suppressed(void) 279{ 280 return rcu_stall_is_suppressed_at_boot() || rcu_cpu_stall_suppress; 281} 282 283#define rcu_ftrace_dump_stall_suppress() \ 284do { \ 285 if (!rcu_cpu_stall_suppress) \ 286 rcu_cpu_stall_suppress = 3; \ 287} while (0) 288 289#define rcu_ftrace_dump_stall_unsuppress() \ 290do { \ 291 if (rcu_cpu_stall_suppress == 3) \ 292 rcu_cpu_stall_suppress = 0; \ 293} while (0) 294 295#else /* #endif #ifdef CONFIG_RCU_STALL_COMMON */ 296 297static inline bool rcu_stall_is_suppressed(void) 298{ 299 return rcu_stall_is_suppressed_at_boot(); 300} 301#define rcu_ftrace_dump_stall_suppress() 302#define rcu_ftrace_dump_stall_unsuppress() 303#endif /* #ifdef CONFIG_RCU_STALL_COMMON */ 304 305/* 306 * Strings used in tracepoints need to be exported via the 307 * tracing system such that tools like perf and trace-cmd can 308 * translate the string address pointers to actual text. 309 */ 310#define TPS(x) tracepoint_string(x) 311 312/* 313 * Dump the ftrace buffer, but only one time per callsite per boot. 314 */ 315#define rcu_ftrace_dump(oops_dump_mode) \ 316do { \ 317 static atomic_t ___rfd_beenhere = ATOMIC_INIT(0); \ 318 \ 319 if (!atomic_read(&___rfd_beenhere) && \ 320 !atomic_xchg(&___rfd_beenhere, 1)) { \ 321 tracing_off(); \ 322 rcu_ftrace_dump_stall_suppress(); \ 323 ftrace_dump(oops_dump_mode); \ 324 rcu_ftrace_dump_stall_unsuppress(); \ 325 } \ 326} while (0) 327 328void rcu_early_boot_tests(void); 329void rcu_test_sync_prims(void); 330 331/* 332 * This function really isn't for public consumption, but RCU is special in 333 * that context switches can allow the state machine to make progress. 334 */ 335extern void resched_cpu(int cpu); 336 337#if !defined(CONFIG_TINY_RCU) 338 339#include <linux/rcu_node_tree.h> 340 341extern int rcu_num_lvls; 342extern int num_rcu_lvl[]; 343extern int rcu_num_nodes; 344static bool rcu_fanout_exact; 345static int rcu_fanout_leaf; 346 347/* 348 * Compute the per-level fanout, either using the exact fanout specified 349 * or balancing the tree, depending on the rcu_fanout_exact boot parameter. 350 */ 351static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt) 352{ 353 int i; 354 355 for (i = 0; i < RCU_NUM_LVLS; i++) 356 levelspread[i] = INT_MIN; 357 if (rcu_fanout_exact) { 358 levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf; 359 for (i = rcu_num_lvls - 2; i >= 0; i--) 360 levelspread[i] = RCU_FANOUT; 361 } else { 362 int ccur; 363 int cprv; 364 365 cprv = nr_cpu_ids; 366 for (i = rcu_num_lvls - 1; i >= 0; i--) { 367 ccur = levelcnt[i]; 368 levelspread[i] = (cprv + ccur - 1) / ccur; 369 cprv = ccur; 370 } 371 } 372} 373 374extern void rcu_init_geometry(void); 375 376/* Returns a pointer to the first leaf rcu_node structure. */ 377#define rcu_first_leaf_node() (rcu_state.level[rcu_num_lvls - 1]) 378 379/* Is this rcu_node a leaf? */ 380#define rcu_is_leaf_node(rnp) ((rnp)->level == rcu_num_lvls - 1) 381 382/* Is this rcu_node the last leaf? */ 383#define rcu_is_last_leaf_node(rnp) ((rnp) == &rcu_state.node[rcu_num_nodes - 1]) 384 385/* 386 * Do a full breadth-first scan of the {s,}rcu_node structures for the 387 * specified state structure (for SRCU) or the only rcu_state structure 388 * (for RCU). 389 */ 390#define _rcu_for_each_node_breadth_first(sp, rnp) \ 391 for ((rnp) = &(sp)->node[0]; \ 392 (rnp) < &(sp)->node[rcu_num_nodes]; (rnp)++) 393#define rcu_for_each_node_breadth_first(rnp) \ 394 _rcu_for_each_node_breadth_first(&rcu_state, rnp) 395#define srcu_for_each_node_breadth_first(ssp, rnp) \ 396 _rcu_for_each_node_breadth_first(ssp->srcu_sup, rnp) 397 398/* 399 * Scan the leaves of the rcu_node hierarchy for the rcu_state structure. 400 * Note that if there is a singleton rcu_node tree with but one rcu_node 401 * structure, this loop -will- visit the rcu_node structure. It is still 402 * a leaf node, even if it is also the root node. 403 */ 404#define rcu_for_each_leaf_node(rnp) \ 405 for ((rnp) = rcu_first_leaf_node(); \ 406 (rnp) < &rcu_state.node[rcu_num_nodes]; (rnp)++) 407 408/* 409 * Iterate over all possible CPUs in a leaf RCU node. 410 */ 411#define for_each_leaf_node_possible_cpu(rnp, cpu) \ 412 for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \ 413 (cpu) = cpumask_next((rnp)->grplo - 1, cpu_possible_mask); \ 414 (cpu) <= rnp->grphi; \ 415 (cpu) = cpumask_next((cpu), cpu_possible_mask)) 416 417/* 418 * Iterate over all CPUs in a leaf RCU node's specified mask. 419 */ 420#define rcu_find_next_bit(rnp, cpu, mask) \ 421 ((rnp)->grplo + find_next_bit(&(mask), BITS_PER_LONG, (cpu))) 422#define for_each_leaf_node_cpu_mask(rnp, cpu, mask) \ 423 for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \ 424 (cpu) = rcu_find_next_bit((rnp), 0, (mask)); \ 425 (cpu) <= rnp->grphi; \ 426 (cpu) = rcu_find_next_bit((rnp), (cpu) + 1 - (rnp->grplo), (mask))) 427 428#endif /* !defined(CONFIG_TINY_RCU) */ 429 430#if !defined(CONFIG_TINY_RCU) || defined(CONFIG_TASKS_RCU_GENERIC) 431 432/* 433 * Wrappers for the rcu_node::lock acquire and release. 434 * 435 * Because the rcu_nodes form a tree, the tree traversal locking will observe 436 * different lock values, this in turn means that an UNLOCK of one level 437 * followed by a LOCK of another level does not imply a full memory barrier; 438 * and most importantly transitivity is lost. 439 * 440 * In order to restore full ordering between tree levels, augment the regular 441 * lock acquire functions with smp_mb__after_unlock_lock(). 442 * 443 * As ->lock of struct rcu_node is a __private field, therefore one should use 444 * these wrappers rather than directly call raw_spin_{lock,unlock}* on ->lock. 445 */ 446#define raw_spin_lock_rcu_node(p) \ 447do { \ 448 raw_spin_lock(&ACCESS_PRIVATE(p, lock)); \ 449 smp_mb__after_unlock_lock(); \ 450} while (0) 451 452#define raw_spin_unlock_rcu_node(p) \ 453do { \ 454 lockdep_assert_irqs_disabled(); \ 455 raw_spin_unlock(&ACCESS_PRIVATE(p, lock)); \ 456} while (0) 457 458#define raw_spin_lock_irq_rcu_node(p) \ 459do { \ 460 raw_spin_lock_irq(&ACCESS_PRIVATE(p, lock)); \ 461 smp_mb__after_unlock_lock(); \ 462} while (0) 463 464#define raw_spin_unlock_irq_rcu_node(p) \ 465do { \ 466 lockdep_assert_irqs_disabled(); \ 467 raw_spin_unlock_irq(&ACCESS_PRIVATE(p, lock)); \ 468} while (0) 469 470#define raw_spin_lock_irqsave_rcu_node(p, flags) \ 471do { \ 472 raw_spin_lock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \ 473 smp_mb__after_unlock_lock(); \ 474} while (0) 475 476#define raw_spin_unlock_irqrestore_rcu_node(p, flags) \ 477do { \ 478 lockdep_assert_irqs_disabled(); \ 479 raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags); \ 480} while (0) 481 482#define raw_spin_trylock_rcu_node(p) \ 483({ \ 484 bool ___locked = raw_spin_trylock(&ACCESS_PRIVATE(p, lock)); \ 485 \ 486 if (___locked) \ 487 smp_mb__after_unlock_lock(); \ 488 ___locked; \ 489}) 490 491#define raw_lockdep_assert_held_rcu_node(p) \ 492 lockdep_assert_held(&ACCESS_PRIVATE(p, lock)) 493 494#endif // #if !defined(CONFIG_TINY_RCU) || defined(CONFIG_TASKS_RCU_GENERIC) 495 496#ifdef CONFIG_TINY_RCU 497/* Tiny RCU doesn't expedite, as its purpose in life is instead to be tiny. */ 498static inline bool rcu_gp_is_normal(void) { return true; } 499static inline bool rcu_gp_is_expedited(void) { return false; } 500static inline bool rcu_async_should_hurry(void) { return false; } 501static inline void rcu_expedite_gp(void) { } 502static inline void rcu_unexpedite_gp(void) { } 503static inline void rcu_async_hurry(void) { } 504static inline void rcu_async_relax(void) { } 505static inline bool rcu_cpu_online(int cpu) { return true; } 506#else /* #ifdef CONFIG_TINY_RCU */ 507bool rcu_gp_is_normal(void); /* Internal RCU use. */ 508bool rcu_gp_is_expedited(void); /* Internal RCU use. */ 509bool rcu_async_should_hurry(void); /* Internal RCU use. */ 510void rcu_expedite_gp(void); 511void rcu_unexpedite_gp(void); 512void rcu_async_hurry(void); 513void rcu_async_relax(void); 514void rcupdate_announce_bootup_oddness(void); 515bool rcu_cpu_online(int cpu); 516#ifdef CONFIG_TASKS_RCU_GENERIC 517void show_rcu_tasks_gp_kthreads(void); 518#else /* #ifdef CONFIG_TASKS_RCU_GENERIC */ 519static inline void show_rcu_tasks_gp_kthreads(void) {} 520#endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */ 521#endif /* #else #ifdef CONFIG_TINY_RCU */ 522 523#ifdef CONFIG_TASKS_RCU 524struct task_struct *get_rcu_tasks_gp_kthread(void); 525#endif // # ifdef CONFIG_TASKS_RCU 526 527#ifdef CONFIG_TASKS_RUDE_RCU 528struct task_struct *get_rcu_tasks_rude_gp_kthread(void); 529#endif // # ifdef CONFIG_TASKS_RUDE_RCU 530 531#ifdef CONFIG_TASKS_RCU_GENERIC 532void tasks_cblist_init_generic(void); 533#else /* #ifdef CONFIG_TASKS_RCU_GENERIC */ 534static inline void tasks_cblist_init_generic(void) { } 535#endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */ 536 537#define RCU_SCHEDULER_INACTIVE 0 538#define RCU_SCHEDULER_INIT 1 539#define RCU_SCHEDULER_RUNNING 2 540 541enum rcutorture_type { 542 RCU_FLAVOR, 543 RCU_TASKS_FLAVOR, 544 RCU_TASKS_RUDE_FLAVOR, 545 RCU_TASKS_TRACING_FLAVOR, 546 RCU_TRIVIAL_FLAVOR, 547 SRCU_FLAVOR, 548 INVALID_RCU_FLAVOR 549}; 550 551#if defined(CONFIG_RCU_LAZY) 552unsigned long rcu_get_jiffies_lazy_flush(void); 553void rcu_set_jiffies_lazy_flush(unsigned long j); 554#else 555static inline unsigned long rcu_get_jiffies_lazy_flush(void) { return 0; } 556static inline void rcu_set_jiffies_lazy_flush(unsigned long j) { } 557#endif 558 559#if defined(CONFIG_TREE_RCU) 560void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags, 561 unsigned long *gp_seq); 562void do_trace_rcu_torture_read(const char *rcutorturename, 563 struct rcu_head *rhp, 564 unsigned long secs, 565 unsigned long c_old, 566 unsigned long c); 567void rcu_gp_set_torture_wait(int duration); 568#else 569static inline void rcutorture_get_gp_data(enum rcutorture_type test_type, 570 int *flags, unsigned long *gp_seq) 571{ 572 *flags = 0; 573 *gp_seq = 0; 574} 575#ifdef CONFIG_RCU_TRACE 576void do_trace_rcu_torture_read(const char *rcutorturename, 577 struct rcu_head *rhp, 578 unsigned long secs, 579 unsigned long c_old, 580 unsigned long c); 581#else 582#define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \ 583 do { } while (0) 584#endif 585static inline void rcu_gp_set_torture_wait(int duration) { } 586#endif 587 588#ifdef CONFIG_TINY_SRCU 589 590static inline void srcutorture_get_gp_data(enum rcutorture_type test_type, 591 struct srcu_struct *sp, int *flags, 592 unsigned long *gp_seq) 593{ 594 if (test_type != SRCU_FLAVOR) 595 return; 596 *flags = 0; 597 *gp_seq = sp->srcu_idx; 598} 599 600#elif defined(CONFIG_TREE_SRCU) 601 602void srcutorture_get_gp_data(enum rcutorture_type test_type, 603 struct srcu_struct *sp, int *flags, 604 unsigned long *gp_seq); 605 606#endif 607 608#ifdef CONFIG_TINY_RCU 609static inline bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) { return false; } 610static inline unsigned long rcu_get_gp_seq(void) { return 0; } 611static inline unsigned long rcu_exp_batches_completed(void) { return 0; } 612static inline unsigned long 613srcu_batches_completed(struct srcu_struct *sp) { return 0; } 614static inline void rcu_force_quiescent_state(void) { } 615static inline bool rcu_check_boost_fail(unsigned long gp_state, int *cpup) { return true; } 616static inline void show_rcu_gp_kthreads(void) { } 617static inline int rcu_get_gp_kthreads_prio(void) { return 0; } 618static inline void rcu_fwd_progress_check(unsigned long j) { } 619static inline void rcu_gp_slow_register(atomic_t *rgssp) { } 620static inline void rcu_gp_slow_unregister(atomic_t *rgssp) { } 621#else /* #ifdef CONFIG_TINY_RCU */ 622bool rcu_dynticks_zero_in_eqs(int cpu, int *vp); 623unsigned long rcu_get_gp_seq(void); 624unsigned long rcu_exp_batches_completed(void); 625unsigned long srcu_batches_completed(struct srcu_struct *sp); 626bool rcu_check_boost_fail(unsigned long gp_state, int *cpup); 627void show_rcu_gp_kthreads(void); 628int rcu_get_gp_kthreads_prio(void); 629void rcu_fwd_progress_check(unsigned long j); 630void rcu_force_quiescent_state(void); 631extern struct workqueue_struct *rcu_gp_wq; 632extern struct kthread_worker *rcu_exp_gp_kworker; 633void rcu_gp_slow_register(atomic_t *rgssp); 634void rcu_gp_slow_unregister(atomic_t *rgssp); 635#endif /* #else #ifdef CONFIG_TINY_RCU */ 636 637#ifdef CONFIG_RCU_NOCB_CPU 638void rcu_bind_current_to_nocb(void); 639#else 640static inline void rcu_bind_current_to_nocb(void) { } 641#endif 642 643#if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RCU) 644void show_rcu_tasks_classic_gp_kthread(void); 645#else 646static inline void show_rcu_tasks_classic_gp_kthread(void) {} 647#endif 648#if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RUDE_RCU) 649void show_rcu_tasks_rude_gp_kthread(void); 650#else 651static inline void show_rcu_tasks_rude_gp_kthread(void) {} 652#endif 653#if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_TRACE_RCU) 654void show_rcu_tasks_trace_gp_kthread(void); 655#else 656static inline void show_rcu_tasks_trace_gp_kthread(void) {} 657#endif 658 659#ifdef CONFIG_TINY_RCU 660static inline bool rcu_cpu_beenfullyonline(int cpu) { return true; } 661#else 662bool rcu_cpu_beenfullyonline(int cpu); 663#endif 664 665#if defined(CONFIG_RCU_STALL_COMMON) && defined(CONFIG_RCU_CPU_STALL_NOTIFIER) 666int rcu_stall_notifier_call_chain(unsigned long val, void *v); 667#else // #if defined(CONFIG_RCU_STALL_COMMON) && defined(CONFIG_RCU_CPU_STALL_NOTIFIER) 668static inline int rcu_stall_notifier_call_chain(unsigned long val, void *v) { return NOTIFY_DONE; } 669#endif // #else // #if defined(CONFIG_RCU_STALL_COMMON) && defined(CONFIG_RCU_CPU_STALL_NOTIFIER) 670 671#endif /* __LINUX_RCU_H */ 672