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 #ifdef CONFIG_RCU_STALL_COMMON 266 267 extern int rcu_cpu_stall_ftrace_dump; 268 extern int rcu_cpu_stall_suppress; 269 extern int rcu_cpu_stall_timeout; 270 extern int rcu_exp_cpu_stall_timeout; 271 extern int rcu_cpu_stall_cputime; 272 extern bool rcu_exp_stall_task_details __read_mostly; 273 int rcu_jiffies_till_stall_check(void); 274 int rcu_exp_jiffies_till_stall_check(void); 275 276 static inline bool rcu_stall_is_suppressed(void) 277 { 278 return rcu_stall_is_suppressed_at_boot() || rcu_cpu_stall_suppress; 279 } 280 281 #define rcu_ftrace_dump_stall_suppress() \ 282 do { \ 283 if (!rcu_cpu_stall_suppress) \ 284 rcu_cpu_stall_suppress = 3; \ 285 } while (0) 286 287 #define rcu_ftrace_dump_stall_unsuppress() \ 288 do { \ 289 if (rcu_cpu_stall_suppress == 3) \ 290 rcu_cpu_stall_suppress = 0; \ 291 } while (0) 292 293 #else /* #endif #ifdef CONFIG_RCU_STALL_COMMON */ 294 295 static inline bool rcu_stall_is_suppressed(void) 296 { 297 return rcu_stall_is_suppressed_at_boot(); 298 } 299 #define rcu_ftrace_dump_stall_suppress() 300 #define rcu_ftrace_dump_stall_unsuppress() 301 #endif /* #ifdef CONFIG_RCU_STALL_COMMON */ 302 303 /* 304 * Strings used in tracepoints need to be exported via the 305 * tracing system such that tools like perf and trace-cmd can 306 * translate the string address pointers to actual text. 307 */ 308 #define TPS(x) tracepoint_string(x) 309 310 /* 311 * Dump the ftrace buffer, but only one time per callsite per boot. 312 */ 313 #define rcu_ftrace_dump(oops_dump_mode) \ 314 do { \ 315 static atomic_t ___rfd_beenhere = ATOMIC_INIT(0); \ 316 \ 317 if (!atomic_read(&___rfd_beenhere) && \ 318 !atomic_xchg(&___rfd_beenhere, 1)) { \ 319 tracing_off(); \ 320 rcu_ftrace_dump_stall_suppress(); \ 321 ftrace_dump(oops_dump_mode); \ 322 rcu_ftrace_dump_stall_unsuppress(); \ 323 } \ 324 } while (0) 325 326 void rcu_early_boot_tests(void); 327 void rcu_test_sync_prims(void); 328 329 /* 330 * This function really isn't for public consumption, but RCU is special in 331 * that context switches can allow the state machine to make progress. 332 */ 333 extern void resched_cpu(int cpu); 334 335 #if !defined(CONFIG_TINY_RCU) 336 337 #include <linux/rcu_node_tree.h> 338 339 extern int rcu_num_lvls; 340 extern int num_rcu_lvl[]; 341 extern int rcu_num_nodes; 342 static bool rcu_fanout_exact; 343 static int rcu_fanout_leaf; 344 345 /* 346 * Compute the per-level fanout, either using the exact fanout specified 347 * or balancing the tree, depending on the rcu_fanout_exact boot parameter. 348 */ 349 static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt) 350 { 351 int i; 352 353 for (i = 0; i < RCU_NUM_LVLS; i++) 354 levelspread[i] = INT_MIN; 355 if (rcu_fanout_exact) { 356 levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf; 357 for (i = rcu_num_lvls - 2; i >= 0; i--) 358 levelspread[i] = RCU_FANOUT; 359 } else { 360 int ccur; 361 int cprv; 362 363 cprv = nr_cpu_ids; 364 for (i = rcu_num_lvls - 1; i >= 0; i--) { 365 ccur = levelcnt[i]; 366 levelspread[i] = (cprv + ccur - 1) / ccur; 367 cprv = ccur; 368 } 369 } 370 } 371 372 extern void rcu_init_geometry(void); 373 374 /* Returns a pointer to the first leaf rcu_node structure. */ 375 #define rcu_first_leaf_node() (rcu_state.level[rcu_num_lvls - 1]) 376 377 /* Is this rcu_node a leaf? */ 378 #define rcu_is_leaf_node(rnp) ((rnp)->level == rcu_num_lvls - 1) 379 380 /* Is this rcu_node the last leaf? */ 381 #define rcu_is_last_leaf_node(rnp) ((rnp) == &rcu_state.node[rcu_num_nodes - 1]) 382 383 /* 384 * Do a full breadth-first scan of the {s,}rcu_node structures for the 385 * specified state structure (for SRCU) or the only rcu_state structure 386 * (for RCU). 387 */ 388 #define _rcu_for_each_node_breadth_first(sp, rnp) \ 389 for ((rnp) = &(sp)->node[0]; \ 390 (rnp) < &(sp)->node[rcu_num_nodes]; (rnp)++) 391 #define rcu_for_each_node_breadth_first(rnp) \ 392 _rcu_for_each_node_breadth_first(&rcu_state, rnp) 393 #define srcu_for_each_node_breadth_first(ssp, rnp) \ 394 _rcu_for_each_node_breadth_first(ssp->srcu_sup, rnp) 395 396 /* 397 * Scan the leaves of the rcu_node hierarchy for the rcu_state structure. 398 * Note that if there is a singleton rcu_node tree with but one rcu_node 399 * structure, this loop -will- visit the rcu_node structure. It is still 400 * a leaf node, even if it is also the root node. 401 */ 402 #define rcu_for_each_leaf_node(rnp) \ 403 for ((rnp) = rcu_first_leaf_node(); \ 404 (rnp) < &rcu_state.node[rcu_num_nodes]; (rnp)++) 405 406 /* 407 * Iterate over all possible CPUs in a leaf RCU node. 408 */ 409 #define for_each_leaf_node_possible_cpu(rnp, cpu) \ 410 for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \ 411 (cpu) = cpumask_next((rnp)->grplo - 1, cpu_possible_mask); \ 412 (cpu) <= rnp->grphi; \ 413 (cpu) = cpumask_next((cpu), cpu_possible_mask)) 414 415 /* 416 * Iterate over all CPUs in a leaf RCU node's specified mask. 417 */ 418 #define rcu_find_next_bit(rnp, cpu, mask) \ 419 ((rnp)->grplo + find_next_bit(&(mask), BITS_PER_LONG, (cpu))) 420 #define for_each_leaf_node_cpu_mask(rnp, cpu, mask) \ 421 for (WARN_ON_ONCE(!rcu_is_leaf_node(rnp)), \ 422 (cpu) = rcu_find_next_bit((rnp), 0, (mask)); \ 423 (cpu) <= rnp->grphi; \ 424 (cpu) = rcu_find_next_bit((rnp), (cpu) + 1 - (rnp->grplo), (mask))) 425 426 #endif /* !defined(CONFIG_TINY_RCU) */ 427 428 #if !defined(CONFIG_TINY_RCU) || defined(CONFIG_TASKS_RCU_GENERIC) 429 430 /* 431 * Wrappers for the rcu_node::lock acquire and release. 432 * 433 * Because the rcu_nodes form a tree, the tree traversal locking will observe 434 * different lock values, this in turn means that an UNLOCK of one level 435 * followed by a LOCK of another level does not imply a full memory barrier; 436 * and most importantly transitivity is lost. 437 * 438 * In order to restore full ordering between tree levels, augment the regular 439 * lock acquire functions with smp_mb__after_unlock_lock(). 440 * 441 * As ->lock of struct rcu_node is a __private field, therefore one should use 442 * these wrappers rather than directly call raw_spin_{lock,unlock}* on ->lock. 443 */ 444 #define raw_spin_lock_rcu_node(p) \ 445 do { \ 446 raw_spin_lock(&ACCESS_PRIVATE(p, lock)); \ 447 smp_mb__after_unlock_lock(); \ 448 } while (0) 449 450 #define raw_spin_unlock_rcu_node(p) \ 451 do { \ 452 lockdep_assert_irqs_disabled(); \ 453 raw_spin_unlock(&ACCESS_PRIVATE(p, lock)); \ 454 } while (0) 455 456 #define raw_spin_lock_irq_rcu_node(p) \ 457 do { \ 458 raw_spin_lock_irq(&ACCESS_PRIVATE(p, lock)); \ 459 smp_mb__after_unlock_lock(); \ 460 } while (0) 461 462 #define raw_spin_unlock_irq_rcu_node(p) \ 463 do { \ 464 lockdep_assert_irqs_disabled(); \ 465 raw_spin_unlock_irq(&ACCESS_PRIVATE(p, lock)); \ 466 } while (0) 467 468 #define raw_spin_lock_irqsave_rcu_node(p, flags) \ 469 do { \ 470 raw_spin_lock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \ 471 smp_mb__after_unlock_lock(); \ 472 } while (0) 473 474 #define raw_spin_unlock_irqrestore_rcu_node(p, flags) \ 475 do { \ 476 lockdep_assert_irqs_disabled(); \ 477 raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags); \ 478 } while (0) 479 480 #define raw_spin_trylock_rcu_node(p) \ 481 ({ \ 482 bool ___locked = raw_spin_trylock(&ACCESS_PRIVATE(p, lock)); \ 483 \ 484 if (___locked) \ 485 smp_mb__after_unlock_lock(); \ 486 ___locked; \ 487 }) 488 489 #define raw_lockdep_assert_held_rcu_node(p) \ 490 lockdep_assert_held(&ACCESS_PRIVATE(p, lock)) 491 492 #endif // #if !defined(CONFIG_TINY_RCU) || defined(CONFIG_TASKS_RCU_GENERIC) 493 494 #ifdef CONFIG_TINY_RCU 495 /* Tiny RCU doesn't expedite, as its purpose in life is instead to be tiny. */ 496 static inline bool rcu_gp_is_normal(void) { return true; } 497 static inline bool rcu_gp_is_expedited(void) { return false; } 498 static inline bool rcu_async_should_hurry(void) { return false; } 499 static inline void rcu_expedite_gp(void) { } 500 static inline void rcu_unexpedite_gp(void) { } 501 static inline void rcu_async_hurry(void) { } 502 static inline void rcu_async_relax(void) { } 503 static inline bool rcu_cpu_online(int cpu) { return true; } 504 #else /* #ifdef CONFIG_TINY_RCU */ 505 bool rcu_gp_is_normal(void); /* Internal RCU use. */ 506 bool rcu_gp_is_expedited(void); /* Internal RCU use. */ 507 bool rcu_async_should_hurry(void); /* Internal RCU use. */ 508 void rcu_expedite_gp(void); 509 void rcu_unexpedite_gp(void); 510 void rcu_async_hurry(void); 511 void rcu_async_relax(void); 512 void rcupdate_announce_bootup_oddness(void); 513 bool rcu_cpu_online(int cpu); 514 #ifdef CONFIG_TASKS_RCU_GENERIC 515 void show_rcu_tasks_gp_kthreads(void); 516 #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */ 517 static inline void show_rcu_tasks_gp_kthreads(void) {} 518 #endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */ 519 #endif /* #else #ifdef CONFIG_TINY_RCU */ 520 521 #ifdef CONFIG_TASKS_RCU 522 struct task_struct *get_rcu_tasks_gp_kthread(void); 523 #endif // # ifdef CONFIG_TASKS_RCU 524 525 #ifdef CONFIG_TASKS_RUDE_RCU 526 struct task_struct *get_rcu_tasks_rude_gp_kthread(void); 527 #endif // # ifdef CONFIG_TASKS_RUDE_RCU 528 529 #define RCU_SCHEDULER_INACTIVE 0 530 #define RCU_SCHEDULER_INIT 1 531 #define RCU_SCHEDULER_RUNNING 2 532 533 enum rcutorture_type { 534 RCU_FLAVOR, 535 RCU_TASKS_FLAVOR, 536 RCU_TASKS_RUDE_FLAVOR, 537 RCU_TASKS_TRACING_FLAVOR, 538 RCU_TRIVIAL_FLAVOR, 539 SRCU_FLAVOR, 540 INVALID_RCU_FLAVOR 541 }; 542 543 #if defined(CONFIG_RCU_LAZY) 544 unsigned long rcu_lazy_get_jiffies_till_flush(void); 545 void rcu_lazy_set_jiffies_till_flush(unsigned long j); 546 #else 547 static inline unsigned long rcu_lazy_get_jiffies_till_flush(void) { return 0; } 548 static inline void rcu_lazy_set_jiffies_till_flush(unsigned long j) { } 549 #endif 550 551 #if defined(CONFIG_TREE_RCU) 552 void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags, 553 unsigned long *gp_seq); 554 void do_trace_rcu_torture_read(const char *rcutorturename, 555 struct rcu_head *rhp, 556 unsigned long secs, 557 unsigned long c_old, 558 unsigned long c); 559 void rcu_gp_set_torture_wait(int duration); 560 #else 561 static inline void rcutorture_get_gp_data(enum rcutorture_type test_type, 562 int *flags, unsigned long *gp_seq) 563 { 564 *flags = 0; 565 *gp_seq = 0; 566 } 567 #ifdef CONFIG_RCU_TRACE 568 void do_trace_rcu_torture_read(const char *rcutorturename, 569 struct rcu_head *rhp, 570 unsigned long secs, 571 unsigned long c_old, 572 unsigned long c); 573 #else 574 #define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \ 575 do { } while (0) 576 #endif 577 static inline void rcu_gp_set_torture_wait(int duration) { } 578 #endif 579 580 #ifdef CONFIG_TINY_SRCU 581 582 static inline void srcutorture_get_gp_data(enum rcutorture_type test_type, 583 struct srcu_struct *sp, int *flags, 584 unsigned long *gp_seq) 585 { 586 if (test_type != SRCU_FLAVOR) 587 return; 588 *flags = 0; 589 *gp_seq = sp->srcu_idx; 590 } 591 592 #elif defined(CONFIG_TREE_SRCU) 593 594 void srcutorture_get_gp_data(enum rcutorture_type test_type, 595 struct srcu_struct *sp, int *flags, 596 unsigned long *gp_seq); 597 598 #endif 599 600 #ifdef CONFIG_TINY_RCU 601 static inline bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) { return false; } 602 static inline unsigned long rcu_get_gp_seq(void) { return 0; } 603 static inline unsigned long rcu_exp_batches_completed(void) { return 0; } 604 static inline unsigned long 605 srcu_batches_completed(struct srcu_struct *sp) { return 0; } 606 static inline void rcu_force_quiescent_state(void) { } 607 static inline bool rcu_check_boost_fail(unsigned long gp_state, int *cpup) { return true; } 608 static inline void show_rcu_gp_kthreads(void) { } 609 static inline int rcu_get_gp_kthreads_prio(void) { return 0; } 610 static inline void rcu_fwd_progress_check(unsigned long j) { } 611 static inline void rcu_gp_slow_register(atomic_t *rgssp) { } 612 static inline void rcu_gp_slow_unregister(atomic_t *rgssp) { } 613 #else /* #ifdef CONFIG_TINY_RCU */ 614 bool rcu_dynticks_zero_in_eqs(int cpu, int *vp); 615 unsigned long rcu_get_gp_seq(void); 616 unsigned long rcu_exp_batches_completed(void); 617 unsigned long srcu_batches_completed(struct srcu_struct *sp); 618 bool rcu_check_boost_fail(unsigned long gp_state, int *cpup); 619 void show_rcu_gp_kthreads(void); 620 int rcu_get_gp_kthreads_prio(void); 621 void rcu_fwd_progress_check(unsigned long j); 622 void rcu_force_quiescent_state(void); 623 extern struct workqueue_struct *rcu_gp_wq; 624 #ifdef CONFIG_RCU_EXP_KTHREAD 625 extern struct kthread_worker *rcu_exp_gp_kworker; 626 extern struct kthread_worker *rcu_exp_par_gp_kworker; 627 #else /* !CONFIG_RCU_EXP_KTHREAD */ 628 extern struct workqueue_struct *rcu_par_gp_wq; 629 #endif /* CONFIG_RCU_EXP_KTHREAD */ 630 void rcu_gp_slow_register(atomic_t *rgssp); 631 void rcu_gp_slow_unregister(atomic_t *rgssp); 632 #endif /* #else #ifdef CONFIG_TINY_RCU */ 633 634 #ifdef CONFIG_RCU_NOCB_CPU 635 void rcu_bind_current_to_nocb(void); 636 #else 637 static inline void rcu_bind_current_to_nocb(void) { } 638 #endif 639 640 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RCU) 641 void show_rcu_tasks_classic_gp_kthread(void); 642 #else 643 static inline void show_rcu_tasks_classic_gp_kthread(void) {} 644 #endif 645 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_RUDE_RCU) 646 void show_rcu_tasks_rude_gp_kthread(void); 647 #else 648 static inline void show_rcu_tasks_rude_gp_kthread(void) {} 649 #endif 650 #if !defined(CONFIG_TINY_RCU) && defined(CONFIG_TASKS_TRACE_RCU) 651 void show_rcu_tasks_trace_gp_kthread(void); 652 #else 653 static inline void show_rcu_tasks_trace_gp_kthread(void) {} 654 #endif 655 656 #ifdef CONFIG_TINY_RCU 657 static inline bool rcu_cpu_beenfullyonline(int cpu) { return true; } 658 #else 659 bool rcu_cpu_beenfullyonline(int cpu); 660 #endif 661 662 #ifdef CONFIG_RCU_STALL_COMMON 663 int rcu_stall_notifier_call_chain(unsigned long val, void *v); 664 #else // #ifdef CONFIG_RCU_STALL_COMMON 665 static inline int rcu_stall_notifier_call_chain(unsigned long val, void *v) { return NOTIFY_DONE; } 666 #endif // #else // #ifdef CONFIG_RCU_STALL_COMMON 667 668 #endif /* __LINUX_RCU_H */ 669