1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Berkeley Software Design Inc's name may not be used to endorse or 15 * promote products derived from this software without specific prior 16 * written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $ 31 */ 32 33 #ifndef _SYS_MUTEX_H_ 34 #define _SYS_MUTEX_H_ 35 36 #include <sys/queue.h> 37 #include <sys/_lock.h> 38 #include <sys/_mutex.h> 39 40 #ifdef _KERNEL 41 #include <sys/pcpu.h> 42 #include <sys/lock_profile.h> 43 #include <sys/lockstat.h> 44 #include <machine/atomic.h> 45 #include <machine/cpufunc.h> 46 47 /* 48 * Mutex types and options passed to mtx_init(). MTX_QUIET and MTX_DUPOK 49 * can also be passed in. 50 */ 51 #define MTX_DEF 0x00000000 /* DEFAULT (sleep) lock */ 52 #define MTX_SPIN 0x00000001 /* Spin lock (disables interrupts) */ 53 #define MTX_RECURSE 0x00000004 /* Option: lock allowed to recurse */ 54 #define MTX_NOWITNESS 0x00000008 /* Don't do any witness checking. */ 55 #define MTX_NOPROFILE 0x00000020 /* Don't profile this lock */ 56 #define MTX_NEW 0x00000040 /* Don't check for double-init */ 57 58 /* 59 * Option flags passed to certain lock/unlock routines, through the use 60 * of corresponding mtx_{lock,unlock}_flags() interface macros. 61 */ 62 #define MTX_QUIET LOP_QUIET /* Don't log a mutex event */ 63 #define MTX_DUPOK LOP_DUPOK /* Don't log a duplicate acquire */ 64 65 /* 66 * State bits kept in mutex->mtx_lock, for the DEFAULT lock type. None of this, 67 * with the exception of MTX_UNOWNED, applies to spin locks. 68 */ 69 #define MTX_UNOWNED 0x00000000 /* Cookie for free mutex */ 70 #define MTX_RECURSED 0x00000001 /* lock recursed (for MTX_DEF only) */ 71 #define MTX_CONTESTED 0x00000002 /* lock contested (for MTX_DEF only) */ 72 #define MTX_DESTROYED 0x00000004 /* lock destroyed */ 73 #define MTX_FLAGMASK (MTX_RECURSED | MTX_CONTESTED | MTX_DESTROYED) 74 75 /* 76 * Prototypes 77 * 78 * NOTE: Functions prepended with `_' (underscore) are exported to other parts 79 * of the kernel via macros, thus allowing us to use the cpp LOCK_FILE 80 * and LOCK_LINE or for hiding the lock cookie crunching to the 81 * consumers. These functions should not be called directly by any 82 * code using the API. Their macros cover their functionality. 83 * Functions with a `_' suffix are the entrypoint for the common 84 * KPI covering both compat shims and fast path case. These can be 85 * used by consumers willing to pass options, file and line 86 * informations, in an option-independent way. 87 * 88 * [See below for descriptions] 89 * 90 */ 91 void _mtx_init(volatile uintptr_t *c, const char *name, const char *type, 92 int opts); 93 void _mtx_destroy(volatile uintptr_t *c); 94 void mtx_sysinit(void *arg); 95 int _mtx_trylock_flags_int(struct mtx *m, int opts LOCK_FILE_LINE_ARG_DEF); 96 int _mtx_trylock_flags_(volatile uintptr_t *c, int opts, const char *file, 97 int line); 98 void mutex_init(void); 99 #if LOCK_DEBUG > 0 100 void __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v, int opts, 101 const char *file, int line); 102 void __mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v, int opts, 103 const char *file, int line); 104 #else 105 void __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v); 106 void __mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v); 107 #endif 108 void mtx_wait_unlocked(struct mtx *m); 109 110 #ifdef SMP 111 #if LOCK_DEBUG > 0 112 void _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v, int opts, 113 const char *file, int line); 114 #else 115 void _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v); 116 #endif 117 #endif 118 void __mtx_lock_flags(volatile uintptr_t *c, int opts, const char *file, 119 int line); 120 void __mtx_unlock_flags(volatile uintptr_t *c, int opts, const char *file, 121 int line); 122 void __mtx_lock_spin_flags(volatile uintptr_t *c, int opts, const char *file, 123 int line); 124 int __mtx_trylock_spin_flags(volatile uintptr_t *c, int opts, 125 const char *file, int line); 126 void __mtx_unlock_spin_flags(volatile uintptr_t *c, int opts, 127 const char *file, int line); 128 void mtx_spin_wait_unlocked(struct mtx *m); 129 130 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 131 void __mtx_assert(const volatile uintptr_t *c, int what, const char *file, 132 int line); 133 #endif 134 void thread_lock_flags_(struct thread *, int, const char *, int); 135 #if LOCK_DEBUG > 0 136 void _thread_lock(struct thread *td, int opts, const char *file, int line); 137 #else 138 void _thread_lock(struct thread *); 139 #endif 140 141 #if defined(LOCK_PROFILING) || (defined(KLD_MODULE) && !defined(KLD_TIED)) 142 #define thread_lock(tdp) \ 143 thread_lock_flags_((tdp), 0, __FILE__, __LINE__) 144 #elif LOCK_DEBUG > 0 145 #define thread_lock(tdp) \ 146 _thread_lock((tdp), 0, __FILE__, __LINE__) 147 #else 148 #define thread_lock(tdp) \ 149 _thread_lock((tdp)) 150 #endif 151 152 #if LOCK_DEBUG > 0 153 #define thread_lock_flags(tdp, opt) \ 154 thread_lock_flags_((tdp), (opt), __FILE__, __LINE__) 155 #else 156 #define thread_lock_flags(tdp, opt) \ 157 _thread_lock(tdp) 158 #endif 159 160 #define thread_unlock(tdp) \ 161 mtx_unlock_spin((tdp)->td_lock) 162 163 /* 164 * Top-level macros to provide lock cookie once the actual mtx is passed. 165 * They will also prevent passing a malformed object to the mtx KPI by 166 * failing compilation as the mtx_lock reserved member will not be found. 167 */ 168 #define mtx_init(m, n, t, o) \ 169 _mtx_init(&(m)->mtx_lock, n, t, o) 170 #define mtx_destroy(m) \ 171 _mtx_destroy(&(m)->mtx_lock) 172 #define mtx_trylock_flags_(m, o, f, l) \ 173 _mtx_trylock_flags_(&(m)->mtx_lock, o, f, l) 174 #if LOCK_DEBUG > 0 175 #define _mtx_lock_sleep(m, v, o, f, l) \ 176 __mtx_lock_sleep(&(m)->mtx_lock, v, o, f, l) 177 #define _mtx_unlock_sleep(m, v, o, f, l) \ 178 __mtx_unlock_sleep(&(m)->mtx_lock, v, o, f, l) 179 #else 180 #define _mtx_lock_sleep(m, v, o, f, l) \ 181 __mtx_lock_sleep(&(m)->mtx_lock, v) 182 #define _mtx_unlock_sleep(m, v, o, f, l) \ 183 __mtx_unlock_sleep(&(m)->mtx_lock, v) 184 #endif 185 #ifdef SMP 186 #if LOCK_DEBUG > 0 187 #define _mtx_lock_spin(m, v, o, f, l) \ 188 _mtx_lock_spin_cookie(&(m)->mtx_lock, v, o, f, l) 189 #else 190 #define _mtx_lock_spin(m, v, o, f, l) \ 191 _mtx_lock_spin_cookie(&(m)->mtx_lock, v) 192 #endif 193 #endif 194 #define _mtx_lock_flags(m, o, f, l) \ 195 __mtx_lock_flags(&(m)->mtx_lock, o, f, l) 196 #define _mtx_unlock_flags(m, o, f, l) \ 197 __mtx_unlock_flags(&(m)->mtx_lock, o, f, l) 198 #define _mtx_lock_spin_flags(m, o, f, l) \ 199 __mtx_lock_spin_flags(&(m)->mtx_lock, o, f, l) 200 #define _mtx_trylock_spin_flags(m, o, f, l) \ 201 __mtx_trylock_spin_flags(&(m)->mtx_lock, o, f, l) 202 #define _mtx_unlock_spin_flags(m, o, f, l) \ 203 __mtx_unlock_spin_flags(&(m)->mtx_lock, o, f, l) 204 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 205 #define _mtx_assert(m, w, f, l) \ 206 __mtx_assert(&(m)->mtx_lock, w, f, l) 207 #endif 208 209 #define mtx_recurse lock_object.lo_data 210 211 /* Very simple operations on mtx_lock. */ 212 213 /* Try to obtain mtx_lock once. */ 214 #define _mtx_obtain_lock(mp, tid) \ 215 atomic_cmpset_acq_ptr(&(mp)->mtx_lock, MTX_UNOWNED, (tid)) 216 217 #define _mtx_obtain_lock_fetch(mp, vp, tid) \ 218 atomic_fcmpset_acq_ptr(&(mp)->mtx_lock, vp, (tid)) 219 220 /* Try to release mtx_lock if it is unrecursed and uncontested. */ 221 #define _mtx_release_lock(mp, tid) \ 222 atomic_cmpset_rel_ptr(&(mp)->mtx_lock, (tid), MTX_UNOWNED) 223 224 /* Release mtx_lock quickly, assuming we own it. */ 225 #define _mtx_release_lock_quick(mp) \ 226 atomic_store_rel_ptr(&(mp)->mtx_lock, MTX_UNOWNED) 227 228 #define _mtx_release_lock_fetch(mp, vp) \ 229 atomic_fcmpset_rel_ptr(&(mp)->mtx_lock, (vp), MTX_UNOWNED) 230 231 /* 232 * Full lock operations that are suitable to be inlined in non-debug 233 * kernels. If the lock cannot be acquired or released trivially then 234 * the work is deferred to another function. 235 */ 236 237 /* Lock a normal mutex. */ 238 #define __mtx_lock(mp, tid, opts, file, line) __extension__ ({ \ 239 uintptr_t _tid = (uintptr_t)(tid); \ 240 uintptr_t _v = MTX_UNOWNED; \ 241 \ 242 if (__predict_false(LOCKSTAT_PROFILE_ENABLED(adaptive__acquire) ||\ 243 !_mtx_obtain_lock_fetch((mp), &_v, _tid))) \ 244 _mtx_lock_sleep((mp), _v, (opts), (file), (line)); \ 245 (void)0; /* ensure void type for expression */ \ 246 }) 247 248 /* 249 * Lock a spin mutex. For spinlocks, we handle recursion inline (it 250 * turns out that function calls can be significantly expensive on 251 * some architectures). Since spin locks are not _too_ common, 252 * inlining this code is not too big a deal. 253 */ 254 #ifdef SMP 255 #define __mtx_lock_spin(mp, tid, opts, file, line) __extension__ ({ \ 256 uintptr_t _tid = (uintptr_t)(tid); \ 257 uintptr_t _v = MTX_UNOWNED; \ 258 \ 259 spinlock_enter(); \ 260 if (__predict_false(LOCKSTAT_PROFILE_ENABLED(spin__acquire) || \ 261 !_mtx_obtain_lock_fetch((mp), &_v, _tid))) \ 262 _mtx_lock_spin((mp), _v, (opts), (file), (line)); \ 263 (void)0; /* ensure void type for expression */ \ 264 }) 265 #define __mtx_trylock_spin(mp, tid, opts, file, line) __extension__ ({ \ 266 uintptr_t _tid = (uintptr_t)(tid); \ 267 int _ret; \ 268 \ 269 spinlock_enter(); \ 270 if (((mp)->mtx_lock != MTX_UNOWNED || !_mtx_obtain_lock((mp), _tid))) {\ 271 spinlock_exit(); \ 272 _ret = 0; \ 273 } else { \ 274 LOCKSTAT_PROFILE_OBTAIN_SPIN_LOCK_SUCCESS(spin__acquire, \ 275 mp, 0, 0, file, line); \ 276 _ret = 1; \ 277 } \ 278 _ret; \ 279 }) 280 #else /* SMP */ 281 #define __mtx_lock_spin(mp, tid, opts, file, line) __extension__ ({ \ 282 uintptr_t _tid = (uintptr_t)(tid); \ 283 \ 284 spinlock_enter(); \ 285 if ((mp)->mtx_lock == _tid) \ 286 (mp)->mtx_recurse++; \ 287 else { \ 288 KASSERT((mp)->mtx_lock == MTX_UNOWNED, ("corrupt spinlock")); \ 289 (mp)->mtx_lock = _tid; \ 290 } \ 291 (void)0; /* ensure void type for expression */ \ 292 }) 293 #define __mtx_trylock_spin(mp, tid, opts, file, line) __extension__ ({ \ 294 uintptr_t _tid = (uintptr_t)(tid); \ 295 int _ret; \ 296 \ 297 spinlock_enter(); \ 298 if ((mp)->mtx_lock != MTX_UNOWNED) { \ 299 spinlock_exit(); \ 300 _ret = 0; \ 301 } else { \ 302 (mp)->mtx_lock = _tid; \ 303 _ret = 1; \ 304 } \ 305 _ret; \ 306 }) 307 #endif /* SMP */ 308 309 /* Unlock a normal mutex. */ 310 #define __mtx_unlock(mp, tid, opts, file, line) __extension__ ({ \ 311 uintptr_t _v = (uintptr_t)(tid); \ 312 \ 313 if (__predict_false(LOCKSTAT_PROFILE_ENABLED(adaptive__release) ||\ 314 !_mtx_release_lock_fetch((mp), &_v))) \ 315 _mtx_unlock_sleep((mp), _v, (opts), (file), (line)); \ 316 (void)0; /* ensure void type for expression */ \ 317 }) 318 319 /* 320 * Unlock a spin mutex. For spinlocks, we can handle everything 321 * inline, as it's pretty simple and a function call would be too 322 * expensive (at least on some architectures). Since spin locks are 323 * not _too_ common, inlining this code is not too big a deal. 324 * 325 * Since we always perform a spinlock_enter() when attempting to acquire a 326 * spin lock, we need to always perform a matching spinlock_exit() when 327 * releasing a spin lock. This includes the recursion cases. 328 */ 329 #ifdef SMP 330 #define __mtx_unlock_spin(mp) __extension__ ({ \ 331 if (mtx_recursed((mp))) \ 332 (mp)->mtx_recurse--; \ 333 else { \ 334 LOCKSTAT_PROFILE_RELEASE_SPIN_LOCK(spin__release, mp); \ 335 _mtx_release_lock_quick((mp)); \ 336 } \ 337 spinlock_exit(); \ 338 }) 339 #else /* SMP */ 340 #define __mtx_unlock_spin(mp) __extension__ ({ \ 341 if (mtx_recursed((mp))) \ 342 (mp)->mtx_recurse--; \ 343 else { \ 344 LOCKSTAT_PROFILE_RELEASE_SPIN_LOCK(spin__release, mp); \ 345 (mp)->mtx_lock = MTX_UNOWNED; \ 346 } \ 347 spinlock_exit(); \ 348 }) 349 #endif /* SMP */ 350 351 /* 352 * Exported lock manipulation interface. 353 * 354 * mtx_lock(m) locks MTX_DEF mutex `m' 355 * 356 * mtx_lock_spin(m) locks MTX_SPIN mutex `m' 357 * 358 * mtx_unlock(m) unlocks MTX_DEF mutex `m' 359 * 360 * mtx_unlock_spin(m) unlocks MTX_SPIN mutex `m' 361 * 362 * mtx_lock_spin_flags(m, opts) and mtx_lock_flags(m, opts) locks mutex `m' 363 * and passes option flags `opts' to the "hard" function, if required. 364 * With these routines, it is possible to pass flags such as MTX_QUIET 365 * to the appropriate lock manipulation routines. 366 * 367 * mtx_trylock(m) attempts to acquire MTX_DEF mutex `m' but doesn't sleep if 368 * it cannot. Rather, it returns 0 on failure and non-zero on success. 369 * It does NOT handle recursion as we assume that if a caller is properly 370 * using this part of the interface, he will know that the lock in question 371 * is _not_ recursed. 372 * 373 * mtx_trylock_flags(m, opts) is used the same way as mtx_trylock() but accepts 374 * relevant option flags `opts.' 375 * 376 * mtx_trylock_spin(m) attempts to acquire MTX_SPIN mutex `m' but doesn't 377 * spin if it cannot. Rather, it returns 0 on failure and non-zero on 378 * success. It always returns failure for recursed lock attempts. 379 * 380 * mtx_initialized(m) returns non-zero if the lock `m' has been initialized. 381 * 382 * mtx_owned(m) returns non-zero if the current thread owns the lock `m' 383 * 384 * mtx_recursed(m) returns non-zero if the lock `m' is presently recursed. 385 */ 386 #define mtx_lock(m) mtx_lock_flags((m), 0) 387 #define mtx_lock_spin(m) mtx_lock_spin_flags((m), 0) 388 #define mtx_trylock(m) mtx_trylock_flags((m), 0) 389 #define mtx_trylock_spin(m) mtx_trylock_spin_flags((m), 0) 390 #define mtx_unlock(m) mtx_unlock_flags((m), 0) 391 #define mtx_unlock_spin(m) mtx_unlock_spin_flags((m), 0) 392 393 struct mtx_pool; 394 395 struct mtx_pool *mtx_pool_create(const char *mtx_name, int pool_size, int opts); 396 void mtx_pool_destroy(struct mtx_pool **poolp); 397 struct mtx *mtx_pool_find(struct mtx_pool *pool, void *ptr); 398 struct mtx *mtx_pool_alloc(struct mtx_pool *pool); 399 #define mtx_pool_lock(pool, ptr) \ 400 mtx_lock(mtx_pool_find((pool), (ptr))) 401 #define mtx_pool_lock_spin(pool, ptr) \ 402 mtx_lock_spin(mtx_pool_find((pool), (ptr))) 403 #define mtx_pool_unlock(pool, ptr) \ 404 mtx_unlock(mtx_pool_find((pool), (ptr))) 405 #define mtx_pool_unlock_spin(pool, ptr) \ 406 mtx_unlock_spin(mtx_pool_find((pool), (ptr))) 407 408 /* 409 * mtxpool_sleep is a general purpose pool of sleep mutexes. 410 */ 411 extern struct mtx_pool *mtxpool_sleep; 412 413 #ifndef LOCK_DEBUG 414 #error LOCK_DEBUG not defined, include <sys/lock.h> before <sys/mutex.h> 415 #endif 416 #if LOCK_DEBUG > 0 || defined(MUTEX_NOINLINE) 417 #define mtx_lock_flags_(m, opts, file, line) \ 418 _mtx_lock_flags((m), (opts), (file), (line)) 419 #define mtx_unlock_flags_(m, opts, file, line) \ 420 _mtx_unlock_flags((m), (opts), (file), (line)) 421 #define mtx_lock_spin_flags_(m, opts, file, line) \ 422 _mtx_lock_spin_flags((m), (opts), (file), (line)) 423 #define mtx_trylock_spin_flags_(m, opts, file, line) \ 424 _mtx_trylock_spin_flags((m), (opts), (file), (line)) 425 #define mtx_unlock_spin_flags_(m, opts, file, line) \ 426 _mtx_unlock_spin_flags((m), (opts), (file), (line)) 427 #else /* LOCK_DEBUG == 0 && !MUTEX_NOINLINE */ 428 #define mtx_lock_flags_(m, opts, file, line) \ 429 __mtx_lock((m), curthread, (opts), (file), (line)) 430 #define mtx_unlock_flags_(m, opts, file, line) \ 431 __mtx_unlock((m), curthread, (opts), (file), (line)) 432 #define mtx_lock_spin_flags_(m, opts, file, line) \ 433 __mtx_lock_spin((m), curthread, (opts), (file), (line)) 434 #define mtx_trylock_spin_flags_(m, opts, file, line) \ 435 __mtx_trylock_spin((m), curthread, (opts), (file), (line)) 436 #define mtx_unlock_spin_flags_(m, opts, file, line) \ 437 __mtx_unlock_spin((m)) 438 #endif /* LOCK_DEBUG > 0 || MUTEX_NOINLINE */ 439 440 #ifdef INVARIANTS 441 #define mtx_assert_(m, what, file, line) \ 442 _mtx_assert((m), (what), (file), (line)) 443 444 #define GIANT_REQUIRED mtx_assert_(&Giant, MA_OWNED, __FILE__, __LINE__) 445 446 #else /* INVARIANTS */ 447 #define mtx_assert_(m, what, file, line) (void)0 448 #define GIANT_REQUIRED 449 #endif /* INVARIANTS */ 450 451 #define mtx_lock_flags(m, opts) \ 452 mtx_lock_flags_((m), (opts), LOCK_FILE, LOCK_LINE) 453 #define mtx_unlock_flags(m, opts) \ 454 mtx_unlock_flags_((m), (opts), LOCK_FILE, LOCK_LINE) 455 #define mtx_lock_spin_flags(m, opts) \ 456 mtx_lock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE) 457 #define mtx_unlock_spin_flags(m, opts) \ 458 mtx_unlock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE) 459 #define mtx_trylock_flags(m, opts) \ 460 mtx_trylock_flags_((m), (opts), LOCK_FILE, LOCK_LINE) 461 #define mtx_trylock_spin_flags(m, opts) \ 462 mtx_trylock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE) 463 #define mtx_assert(m, what) \ 464 mtx_assert_((m), (what), __FILE__, __LINE__) 465 466 #define mtx_sleep(chan, mtx, pri, wmesg, timo) \ 467 _sleep((chan), &(mtx)->lock_object, (pri), (wmesg), \ 468 tick_sbt * (timo), 0, C_HARDCLOCK) 469 470 #define MTX_READ_VALUE(m) ((m)->mtx_lock) 471 472 #define mtx_initialized(m) lock_initialized(&(m)->lock_object) 473 474 #define lv_mtx_owner(v) ((struct thread *)((v) & ~MTX_FLAGMASK)) 475 476 #define mtx_owner(m) lv_mtx_owner(MTX_READ_VALUE(m)) 477 478 #define mtx_owned(m) (mtx_owner(m) == curthread) 479 480 #define mtx_recursed(m) ((m)->mtx_recurse != 0) 481 482 #define mtx_name(m) ((m)->lock_object.lo_name) 483 484 /* 485 * Global locks. 486 */ 487 extern struct mtx Giant; 488 extern struct mtx blocked_lock; 489 490 /* 491 * Giant lock manipulation and clean exit macros. 492 * Used to replace return with an exit Giant and return. 493 * 494 * Note that DROP_GIANT*() needs to be paired with PICKUP_GIANT() 495 * The #ifndef is to allow lint-like tools to redefine DROP_GIANT. 496 */ 497 #ifndef DROP_GIANT 498 #define DROP_GIANT() \ 499 do { \ 500 int _giantcnt = 0; \ 501 WITNESS_SAVE_DECL(Giant); \ 502 \ 503 if (__predict_false(mtx_owned(&Giant))) { \ 504 WITNESS_SAVE(&Giant.lock_object, Giant); \ 505 for (_giantcnt = 0; mtx_owned(&Giant) && \ 506 !SCHEDULER_STOPPED(); _giantcnt++) \ 507 mtx_unlock(&Giant); \ 508 } 509 510 #define PICKUP_GIANT() \ 511 mtx_assert(&Giant, MA_NOTOWNED); \ 512 if (__predict_false(_giantcnt > 0)) { \ 513 while (_giantcnt--) \ 514 mtx_lock(&Giant); \ 515 WITNESS_RESTORE(&Giant.lock_object, Giant); \ 516 } \ 517 } while (0) 518 #endif 519 520 struct mtx_args { 521 void *ma_mtx; 522 const char *ma_desc; 523 int ma_opts; 524 }; 525 526 #define MTX_SYSINIT(name, mtx, desc, opts) \ 527 static struct mtx_args name##_args = { \ 528 (mtx), \ 529 (desc), \ 530 (opts) \ 531 }; \ 532 SYSINIT(name##_mtx_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ 533 mtx_sysinit, &name##_args); \ 534 SYSUNINIT(name##_mtx_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ 535 _mtx_destroy, __DEVOLATILE(void *, &(mtx)->mtx_lock)) 536 537 /* 538 * The INVARIANTS-enabled mtx_assert() functionality. 539 * 540 * The constants need to be defined for INVARIANT_SUPPORT infrastructure 541 * support as _mtx_assert() itself uses them and the latter implies that 542 * _mtx_assert() must build. 543 */ 544 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 545 #define MA_OWNED LA_XLOCKED 546 #define MA_NOTOWNED LA_UNLOCKED 547 #define MA_RECURSED LA_RECURSED 548 #define MA_NOTRECURSED LA_NOTRECURSED 549 #endif 550 551 /* 552 * Common lock type names. 553 */ 554 #define MTX_NETWORK_LOCK "network driver" 555 556 #endif /* _KERNEL */ 557 #endif /* _SYS_MUTEX_H_ */ 558