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