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 63 extern 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 */ 69 static 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 */ 78 static 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 */ 87 static 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. */ 94 static 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. */ 102 static 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. */ 108 static 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 */ 126 static 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. */ 136 static 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 */ 145 static 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 */ 154 static 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 */ 164 static 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 */ 174 static 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 */ 182 static 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 */ 192 static 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 1 220 221 extern const struct debug_obj_descr rcuhead_debug_descr; 222 223 static 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 } 233 234 static 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 */ 242 static inline int debug_rcu_head_queue(struct rcu_head *head) 243 { 244 return 0; 245 } 246 247 static inline void debug_rcu_head_unqueue(struct rcu_head *head) 248 { 249 } 250 #endif /* #else !CONFIG_DEBUG_OBJECTS_RCU_HEAD */ 251 252 static inline void debug_rcu_head_callback(struct rcu_head *rhp) 253 { 254 if (unlikely(!rhp->func)) 255 kmem_dump_obj(rhp); 256 } 257 258 extern int rcu_cpu_stall_suppress_at_boot; 259 260 static inline bool rcu_stall_is_suppressed_at_boot(void) 261 { 262 return rcu_cpu_stall_suppress_at_boot && !rcu_inkernel_boot_has_ended(); 263 } 264 265 extern int rcu_cpu_stall_notifiers; 266 267 #ifdef CONFIG_RCU_STALL_COMMON 268 269 extern int rcu_cpu_stall_ftrace_dump; 270 extern int rcu_cpu_stall_suppress; 271 extern int rcu_cpu_stall_timeout; 272 extern int rcu_exp_cpu_stall_timeout; 273 extern int rcu_cpu_stall_cputime; 274 extern bool rcu_exp_stall_task_details __read_mostly; 275 int rcu_jiffies_till_stall_check(void); 276 int rcu_exp_jiffies_till_stall_check(void); 277 278 static 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() \ 284 do { \ 285 if (!rcu_cpu_stall_suppress) \ 286 rcu_cpu_stall_suppress = 3; \ 287 } while (0) 288 289 #define rcu_ftrace_dump_stall_unsuppress() \ 290 do { \ 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 */ 296 297 static 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) \ 316 do { \ 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) 327 328 void rcu_early_boot_tests(void); 329 void 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 */ 335 extern void resched_cpu(int cpu); 336 337 #if !defined(CONFIG_TINY_RCU) 338 339 #include <linux/rcu_node_tree.h> 340 341 extern int rcu_num_lvls; 342 extern int num_rcu_lvl[]; 343 extern int rcu_num_nodes; 344 static bool rcu_fanout_exact; 345 static 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 */ 351 static 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 } 373 374 extern 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) \ 447 do { \ 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) \ 453 do { \ 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) \ 459 do { \ 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) \ 465 do { \ 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) \ 471 do { \ 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) \ 477 do { \ 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. */ 498 static inline bool rcu_gp_is_normal(void) { return true; } 499 static inline bool rcu_gp_is_expedited(void) { return false; } 500 static inline bool rcu_async_should_hurry(void) { return false; } 501 static inline void rcu_expedite_gp(void) { } 502 static inline void rcu_unexpedite_gp(void) { } 503 static inline void rcu_async_hurry(void) { } 504 static inline void rcu_async_relax(void) { } 505 static inline bool rcu_cpu_online(int cpu) { return true; } 506 #else /* #ifdef CONFIG_TINY_RCU */ 507 bool rcu_gp_is_normal(void); /* Internal RCU use. */ 508 bool rcu_gp_is_expedited(void); /* Internal RCU use. */ 509 bool rcu_async_should_hurry(void); /* Internal RCU use. */ 510 void rcu_expedite_gp(void); 511 void rcu_unexpedite_gp(void); 512 void rcu_async_hurry(void); 513 void rcu_async_relax(void); 514 void rcupdate_announce_bootup_oddness(void); 515 bool rcu_cpu_online(int cpu); 516 #ifdef CONFIG_TASKS_RCU_GENERIC 517 void show_rcu_tasks_gp_kthreads(void); 518 #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */ 519 static 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 524 struct task_struct *get_rcu_tasks_gp_kthread(void); 525 void rcu_tasks_get_gp_data(int *flags, unsigned long *gp_seq); 526 #endif // # ifdef CONFIG_TASKS_RCU 527 528 #ifdef CONFIG_TASKS_RUDE_RCU 529 struct task_struct *get_rcu_tasks_rude_gp_kthread(void); 530 void rcu_tasks_rude_get_gp_data(int *flags, unsigned long *gp_seq); 531 #endif // # ifdef CONFIG_TASKS_RUDE_RCU 532 533 #ifdef CONFIG_TASKS_TRACE_RCU 534 void rcu_tasks_trace_get_gp_data(int *flags, unsigned long *gp_seq); 535 #endif 536 537 #ifdef CONFIG_TASKS_RCU_GENERIC 538 void tasks_cblist_init_generic(void); 539 #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */ 540 static inline void tasks_cblist_init_generic(void) { } 541 #endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */ 542 543 #define RCU_SCHEDULER_INACTIVE 0 544 #define RCU_SCHEDULER_INIT 1 545 #define RCU_SCHEDULER_RUNNING 2 546 547 enum rcutorture_type { 548 RCU_FLAVOR, 549 RCU_TASKS_FLAVOR, 550 RCU_TASKS_RUDE_FLAVOR, 551 RCU_TASKS_TRACING_FLAVOR, 552 RCU_TRIVIAL_FLAVOR, 553 SRCU_FLAVOR, 554 INVALID_RCU_FLAVOR 555 }; 556 557 #if defined(CONFIG_RCU_LAZY) 558 unsigned long rcu_get_jiffies_lazy_flush(void); 559 void rcu_set_jiffies_lazy_flush(unsigned long j); 560 #else 561 static inline unsigned long rcu_get_jiffies_lazy_flush(void) { return 0; } 562 static inline void rcu_set_jiffies_lazy_flush(unsigned long j) { } 563 #endif 564 565 #if defined(CONFIG_TREE_RCU) 566 void rcutorture_get_gp_data(int *flags, unsigned long *gp_seq); 567 void do_trace_rcu_torture_read(const char *rcutorturename, 568 struct rcu_head *rhp, 569 unsigned long secs, 570 unsigned long c_old, 571 unsigned long c); 572 void rcu_gp_set_torture_wait(int duration); 573 #else 574 static inline void rcutorture_get_gp_data(int *flags, unsigned long *gp_seq) 575 { 576 *flags = 0; 577 *gp_seq = 0; 578 } 579 #ifdef CONFIG_RCU_TRACE 580 void do_trace_rcu_torture_read(const char *rcutorturename, 581 struct rcu_head *rhp, 582 unsigned long secs, 583 unsigned long c_old, 584 unsigned long c); 585 #else 586 #define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \ 587 do { } while (0) 588 #endif 589 static inline void rcu_gp_set_torture_wait(int duration) { } 590 #endif 591 592 #ifdef CONFIG_TINY_SRCU 593 594 static inline void srcutorture_get_gp_data(struct srcu_struct *sp, int *flags, 595 unsigned long *gp_seq) 596 { 597 *flags = 0; 598 *gp_seq = sp->srcu_idx; 599 } 600 601 #elif defined(CONFIG_TREE_SRCU) 602 603 void srcutorture_get_gp_data(struct srcu_struct *sp, int *flags, 604 unsigned long *gp_seq); 605 606 #endif 607 608 #ifdef CONFIG_TINY_RCU 609 static inline bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) { return false; } 610 static inline unsigned long rcu_get_gp_seq(void) { return 0; } 611 static inline unsigned long rcu_exp_batches_completed(void) { return 0; } 612 static inline unsigned long 613 srcu_batches_completed(struct srcu_struct *sp) { return 0; } 614 static inline void rcu_force_quiescent_state(void) { } 615 static inline bool rcu_check_boost_fail(unsigned long gp_state, int *cpup) { return true; } 616 static inline void show_rcu_gp_kthreads(void) { } 617 static inline int rcu_get_gp_kthreads_prio(void) { return 0; } 618 static inline void rcu_fwd_progress_check(unsigned long j) { } 619 static inline void rcu_gp_slow_register(atomic_t *rgssp) { } 620 static inline void rcu_gp_slow_unregister(atomic_t *rgssp) { } 621 #else /* #ifdef CONFIG_TINY_RCU */ 622 bool rcu_dynticks_zero_in_eqs(int cpu, int *vp); 623 unsigned long rcu_get_gp_seq(void); 624 unsigned long rcu_exp_batches_completed(void); 625 unsigned long srcu_batches_completed(struct srcu_struct *sp); 626 bool rcu_check_boost_fail(unsigned long gp_state, int *cpup); 627 void show_rcu_gp_kthreads(void); 628 int rcu_get_gp_kthreads_prio(void); 629 void rcu_fwd_progress_check(unsigned long j); 630 void rcu_force_quiescent_state(void); 631 extern struct workqueue_struct *rcu_gp_wq; 632 extern struct kthread_worker *rcu_exp_gp_kworker; 633 void rcu_gp_slow_register(atomic_t *rgssp); 634 void rcu_gp_slow_unregister(atomic_t *rgssp); 635 #endif /* #else #ifdef CONFIG_TINY_RCU */ 636 637 #ifdef CONFIG_RCU_NOCB_CPU 638 void rcu_bind_current_to_nocb(void); 639 #else 640 static inline void rcu_bind_current_to_nocb(void) { } 641 #endif 642 643 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RCU) 644 void show_rcu_tasks_classic_gp_kthread(void); 645 #else 646 static inline void show_rcu_tasks_classic_gp_kthread(void) {} 647 #endif 648 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RUDE_RCU) 649 void show_rcu_tasks_rude_gp_kthread(void); 650 #else 651 static inline void show_rcu_tasks_rude_gp_kthread(void) {} 652 #endif 653 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_TRACE_RCU) 654 void show_rcu_tasks_trace_gp_kthread(void); 655 #else 656 static inline void show_rcu_tasks_trace_gp_kthread(void) {} 657 #endif 658 659 #ifdef CONFIG_TINY_RCU 660 static inline bool rcu_cpu_beenfullyonline(int cpu) { return true; } 661 #else 662 bool rcu_cpu_beenfullyonline(int cpu); 663 #endif 664 665 #if defined(CONFIG_RCU_STALL_COMMON) && defined(CONFIG_RCU_CPU_STALL_NOTIFIER) 666 int rcu_stall_notifier_call_chain(unsigned long val, void *v); 667 #else // #if defined(CONFIG_RCU_STALL_COMMON) && defined(CONFIG_RCU_CPU_STALL_NOTIFIER) 668 static 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