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 #define MTX_NEW 0x00000040 /* Don't check for double-init */ 56 57 /* 58 * Option flags passed to certain lock/unlock routines, through the use 59 * of corresponding mtx_{lock,unlock}_flags() interface macros. 60 */ 61 #define MTX_QUIET LOP_QUIET /* Don't log a mutex event */ 62 #define MTX_DUPOK LOP_DUPOK /* Don't log a duplicate acquire */ 63 64 /* 65 * State bits kept in mutex->mtx_lock, for the DEFAULT lock type. None of this, 66 * with the exception of MTX_UNOWNED, applies to spin locks. 67 */ 68 #define MTX_RECURSED 0x00000001 /* lock recursed (for MTX_DEF only) */ 69 #define MTX_CONTESTED 0x00000002 /* lock contested (for MTX_DEF only) */ 70 #define MTX_UNOWNED 0x00000004 /* Cookie for free mutex */ 71 #define MTX_FLAGMASK (MTX_RECURSED | MTX_CONTESTED | MTX_UNOWNED) 72 73 /* 74 * Value stored in mutex->mtx_lock to denote a destroyed mutex. 75 */ 76 #define MTX_DESTROYED (MTX_CONTESTED | MTX_UNOWNED) 77 78 /* 79 * Prototypes 80 * 81 * NOTE: Functions prepended with `_' (underscore) are exported to other parts 82 * of the kernel via macros, thus allowing us to use the cpp LOCK_FILE 83 * and LOCK_LINE or for hiding the lock cookie crunching to the 84 * consumers. These functions should not be called directly by any 85 * code using the API. Their macros cover their functionality. 86 * Functions with a `_' suffix are the entrypoint for the common 87 * KPI covering both compat shims and fast path case. These can be 88 * used by consumers willing to pass options, file and line 89 * informations, in an option-independent way. 90 * 91 * [See below for descriptions] 92 * 93 */ 94 void _mtx_init(volatile uintptr_t *c, const char *name, const char *type, 95 int opts); 96 void _mtx_destroy(volatile uintptr_t *c); 97 void mtx_sysinit(void *arg); 98 int _mtx_trylock_flags_(volatile uintptr_t *c, int opts, const char *file, 99 int line); 100 void mutex_init(void); 101 void __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t tid, int opts, 102 const char *file, int line); 103 void __mtx_unlock_sleep(volatile uintptr_t *c, int opts, const char *file, 104 int line); 105 #ifdef SMP 106 void _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t tid, int opts, 107 const char *file, int line); 108 #endif 109 void __mtx_lock_flags(volatile uintptr_t *c, int opts, const char *file, 110 int line); 111 void __mtx_unlock_flags(volatile uintptr_t *c, int opts, const char *file, 112 int line); 113 void __mtx_lock_spin_flags(volatile uintptr_t *c, int opts, const char *file, 114 int line); 115 void __mtx_unlock_spin_flags(volatile uintptr_t *c, int opts, 116 const char *file, int line); 117 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 118 void __mtx_assert(const volatile uintptr_t *c, int what, const char *file, 119 int line); 120 #endif 121 void thread_lock_flags_(struct thread *, int, const char *, int); 122 123 #define thread_lock(tdp) \ 124 thread_lock_flags_((tdp), 0, __FILE__, __LINE__) 125 #define thread_lock_flags(tdp, opt) \ 126 thread_lock_flags_((tdp), (opt), __FILE__, __LINE__) 127 #define thread_unlock(tdp) \ 128 mtx_unlock_spin((tdp)->td_lock) 129 130 /* 131 * Top-level macros to provide lock cookie once the actual mtx is passed. 132 * They will also prevent passing a malformed object to the mtx KPI by 133 * failing compilation as the mtx_lock reserved member will not be found. 134 */ 135 #define mtx_init(m, n, t, o) \ 136 _mtx_init(&(m)->mtx_lock, n, t, o) 137 #define mtx_destroy(m) \ 138 _mtx_destroy(&(m)->mtx_lock) 139 #define mtx_trylock_flags_(m, o, f, l) \ 140 _mtx_trylock_flags_(&(m)->mtx_lock, o, f, l) 141 #define _mtx_lock_sleep(m, t, o, f, l) \ 142 __mtx_lock_sleep(&(m)->mtx_lock, t, o, f, l) 143 #define _mtx_unlock_sleep(m, o, f, l) \ 144 __mtx_unlock_sleep(&(m)->mtx_lock, o, f, l) 145 #ifdef SMP 146 #define _mtx_lock_spin(m, t, o, f, l) \ 147 _mtx_lock_spin_cookie(&(m)->mtx_lock, t, o, f, l) 148 #endif 149 #define _mtx_lock_flags(m, o, f, l) \ 150 __mtx_lock_flags(&(m)->mtx_lock, o, f, l) 151 #define _mtx_unlock_flags(m, o, f, l) \ 152 __mtx_unlock_flags(&(m)->mtx_lock, o, f, l) 153 #define _mtx_lock_spin_flags(m, o, f, l) \ 154 __mtx_lock_spin_flags(&(m)->mtx_lock, o, f, l) 155 #define _mtx_unlock_spin_flags(m, o, f, l) \ 156 __mtx_unlock_spin_flags(&(m)->mtx_lock, o, f, l) 157 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 158 #define _mtx_assert(m, w, f, l) \ 159 __mtx_assert(&(m)->mtx_lock, w, f, l) 160 #endif 161 162 #define mtx_recurse lock_object.lo_data 163 164 /* Very simple operations on mtx_lock. */ 165 166 /* Try to obtain mtx_lock once. */ 167 #define _mtx_obtain_lock(mp, tid) \ 168 atomic_cmpset_acq_ptr(&(mp)->mtx_lock, MTX_UNOWNED, (tid)) 169 170 /* Try to release mtx_lock if it is unrecursed and uncontested. */ 171 #define _mtx_release_lock(mp, tid) \ 172 atomic_cmpset_rel_ptr(&(mp)->mtx_lock, (tid), MTX_UNOWNED) 173 174 /* Release mtx_lock quickly, assuming we own it. */ 175 #define _mtx_release_lock_quick(mp) \ 176 atomic_store_rel_ptr(&(mp)->mtx_lock, MTX_UNOWNED) 177 178 /* 179 * Full lock operations that are suitable to be inlined in non-debug 180 * kernels. If the lock cannot be acquired or released trivially then 181 * the work is deferred to another function. 182 */ 183 184 /* Lock a normal mutex. */ 185 #define __mtx_lock(mp, tid, opts, file, line) do { \ 186 uintptr_t _tid = (uintptr_t)(tid); \ 187 \ 188 if (!_mtx_obtain_lock((mp), _tid)) \ 189 _mtx_lock_sleep((mp), _tid, (opts), (file), (line)); \ 190 else \ 191 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire, \ 192 mp, 0, 0, file, line); \ 193 } while (0) 194 195 /* 196 * Lock a spin mutex. For spinlocks, we handle recursion inline (it 197 * turns out that function calls can be significantly expensive on 198 * some architectures). Since spin locks are not _too_ common, 199 * inlining this code is not too big a deal. 200 */ 201 #ifdef SMP 202 #define __mtx_lock_spin(mp, tid, opts, file, line) do { \ 203 uintptr_t _tid = (uintptr_t)(tid); \ 204 \ 205 spinlock_enter(); \ 206 if (!_mtx_obtain_lock((mp), _tid)) { \ 207 if ((mp)->mtx_lock == _tid) \ 208 (mp)->mtx_recurse++; \ 209 else \ 210 _mtx_lock_spin((mp), _tid, (opts), (file), (line)); \ 211 } else \ 212 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, \ 213 mp, 0, 0, file, line); \ 214 } while (0) 215 #else /* SMP */ 216 #define __mtx_lock_spin(mp, tid, opts, file, line) do { \ 217 uintptr_t _tid = (uintptr_t)(tid); \ 218 \ 219 spinlock_enter(); \ 220 if ((mp)->mtx_lock == _tid) \ 221 (mp)->mtx_recurse++; \ 222 else { \ 223 KASSERT((mp)->mtx_lock == MTX_UNOWNED, ("corrupt spinlock")); \ 224 (mp)->mtx_lock = _tid; \ 225 } \ 226 } while (0) 227 #endif /* SMP */ 228 229 /* Unlock a normal mutex. */ 230 #define __mtx_unlock(mp, tid, opts, file, line) do { \ 231 uintptr_t _tid = (uintptr_t)(tid); \ 232 \ 233 if ((mp)->mtx_recurse == 0) \ 234 LOCKSTAT_PROFILE_RELEASE_LOCK(adaptive__release, mp); \ 235 if (!_mtx_release_lock((mp), _tid)) \ 236 _mtx_unlock_sleep((mp), (opts), (file), (line)); \ 237 } while (0) 238 239 /* 240 * Unlock a spin mutex. For spinlocks, we can handle everything 241 * inline, as it's pretty simple and a function call would be too 242 * expensive (at least on some architectures). Since spin locks are 243 * not _too_ common, inlining this code is not too big a deal. 244 * 245 * Since we always perform a spinlock_enter() when attempting to acquire a 246 * spin lock, we need to always perform a matching spinlock_exit() when 247 * releasing a spin lock. This includes the recursion cases. 248 */ 249 #ifdef SMP 250 #define __mtx_unlock_spin(mp) do { \ 251 if (mtx_recursed((mp))) \ 252 (mp)->mtx_recurse--; \ 253 else { \ 254 LOCKSTAT_PROFILE_RELEASE_LOCK(spin__release, mp); \ 255 _mtx_release_lock_quick((mp)); \ 256 } \ 257 spinlock_exit(); \ 258 } while (0) 259 #else /* SMP */ 260 #define __mtx_unlock_spin(mp) do { \ 261 if (mtx_recursed((mp))) \ 262 (mp)->mtx_recurse--; \ 263 else { \ 264 LOCKSTAT_PROFILE_RELEASE_LOCK(spin__release, mp); \ 265 (mp)->mtx_lock = MTX_UNOWNED; \ 266 } \ 267 spinlock_exit(); \ 268 } while (0) 269 #endif /* SMP */ 270 271 /* 272 * Exported lock manipulation interface. 273 * 274 * mtx_lock(m) locks MTX_DEF mutex `m' 275 * 276 * mtx_lock_spin(m) locks MTX_SPIN mutex `m' 277 * 278 * mtx_unlock(m) unlocks MTX_DEF mutex `m' 279 * 280 * mtx_unlock_spin(m) unlocks MTX_SPIN mutex `m' 281 * 282 * mtx_lock_spin_flags(m, opts) and mtx_lock_flags(m, opts) locks mutex `m' 283 * and passes option flags `opts' to the "hard" function, if required. 284 * With these routines, it is possible to pass flags such as MTX_QUIET 285 * to the appropriate lock manipulation routines. 286 * 287 * mtx_trylock(m) attempts to acquire MTX_DEF mutex `m' but doesn't sleep if 288 * it cannot. Rather, it returns 0 on failure and non-zero on success. 289 * It does NOT handle recursion as we assume that if a caller is properly 290 * using this part of the interface, he will know that the lock in question 291 * is _not_ recursed. 292 * 293 * mtx_trylock_flags(m, opts) is used the same way as mtx_trylock() but accepts 294 * relevant option flags `opts.' 295 * 296 * mtx_initialized(m) returns non-zero if the lock `m' has been initialized. 297 * 298 * mtx_owned(m) returns non-zero if the current thread owns the lock `m' 299 * 300 * mtx_recursed(m) returns non-zero if the lock `m' is presently recursed. 301 */ 302 #define mtx_lock(m) mtx_lock_flags((m), 0) 303 #define mtx_lock_spin(m) mtx_lock_spin_flags((m), 0) 304 #define mtx_trylock(m) mtx_trylock_flags((m), 0) 305 #define mtx_unlock(m) mtx_unlock_flags((m), 0) 306 #define mtx_unlock_spin(m) mtx_unlock_spin_flags((m), 0) 307 308 struct mtx_pool; 309 310 struct mtx_pool *mtx_pool_create(const char *mtx_name, int pool_size, int opts); 311 void mtx_pool_destroy(struct mtx_pool **poolp); 312 struct mtx *mtx_pool_find(struct mtx_pool *pool, void *ptr); 313 struct mtx *mtx_pool_alloc(struct mtx_pool *pool); 314 #define mtx_pool_lock(pool, ptr) \ 315 mtx_lock(mtx_pool_find((pool), (ptr))) 316 #define mtx_pool_lock_spin(pool, ptr) \ 317 mtx_lock_spin(mtx_pool_find((pool), (ptr))) 318 #define mtx_pool_unlock(pool, ptr) \ 319 mtx_unlock(mtx_pool_find((pool), (ptr))) 320 #define mtx_pool_unlock_spin(pool, ptr) \ 321 mtx_unlock_spin(mtx_pool_find((pool), (ptr))) 322 323 /* 324 * mtxpool_sleep is a general purpose pool of sleep mutexes. 325 */ 326 extern struct mtx_pool *mtxpool_sleep; 327 328 #ifndef LOCK_DEBUG 329 #error LOCK_DEBUG not defined, include <sys/lock.h> before <sys/mutex.h> 330 #endif 331 #if LOCK_DEBUG > 0 || defined(MUTEX_NOINLINE) 332 #define mtx_lock_flags_(m, opts, file, line) \ 333 _mtx_lock_flags((m), (opts), (file), (line)) 334 #define mtx_unlock_flags_(m, opts, file, line) \ 335 _mtx_unlock_flags((m), (opts), (file), (line)) 336 #define mtx_lock_spin_flags_(m, opts, file, line) \ 337 _mtx_lock_spin_flags((m), (opts), (file), (line)) 338 #define mtx_unlock_spin_flags_(m, opts, file, line) \ 339 _mtx_unlock_spin_flags((m), (opts), (file), (line)) 340 #else /* LOCK_DEBUG == 0 && !MUTEX_NOINLINE */ 341 #define mtx_lock_flags_(m, opts, file, line) \ 342 __mtx_lock((m), curthread, (opts), (file), (line)) 343 #define mtx_unlock_flags_(m, opts, file, line) \ 344 __mtx_unlock((m), curthread, (opts), (file), (line)) 345 #define mtx_lock_spin_flags_(m, opts, file, line) \ 346 __mtx_lock_spin((m), curthread, (opts), (file), (line)) 347 #define mtx_unlock_spin_flags_(m, opts, file, line) \ 348 __mtx_unlock_spin((m)) 349 #endif /* LOCK_DEBUG > 0 || MUTEX_NOINLINE */ 350 351 #ifdef INVARIANTS 352 #define mtx_assert_(m, what, file, line) \ 353 _mtx_assert((m), (what), (file), (line)) 354 355 #define GIANT_REQUIRED mtx_assert_(&Giant, MA_OWNED, __FILE__, __LINE__) 356 357 #else /* INVARIANTS */ 358 #define mtx_assert_(m, what, file, line) (void)0 359 #define GIANT_REQUIRED 360 #endif /* INVARIANTS */ 361 362 #define mtx_lock_flags(m, opts) \ 363 mtx_lock_flags_((m), (opts), LOCK_FILE, LOCK_LINE) 364 #define mtx_unlock_flags(m, opts) \ 365 mtx_unlock_flags_((m), (opts), LOCK_FILE, LOCK_LINE) 366 #define mtx_lock_spin_flags(m, opts) \ 367 mtx_lock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE) 368 #define mtx_unlock_spin_flags(m, opts) \ 369 mtx_unlock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE) 370 #define mtx_trylock_flags(m, opts) \ 371 mtx_trylock_flags_((m), (opts), LOCK_FILE, LOCK_LINE) 372 #define mtx_assert(m, what) \ 373 mtx_assert_((m), (what), __FILE__, __LINE__) 374 375 #define mtx_sleep(chan, mtx, pri, wmesg, timo) \ 376 _sleep((chan), &(mtx)->lock_object, (pri), (wmesg), \ 377 tick_sbt * (timo), 0, C_HARDCLOCK) 378 379 #define mtx_initialized(m) lock_initialized(&(m)->lock_object) 380 381 #define mtx_owned(m) (((m)->mtx_lock & ~MTX_FLAGMASK) == (uintptr_t)curthread) 382 383 #define mtx_recursed(m) ((m)->mtx_recurse != 0) 384 385 #define mtx_name(m) ((m)->lock_object.lo_name) 386 387 /* 388 * Global locks. 389 */ 390 extern struct mtx Giant; 391 extern struct mtx blocked_lock; 392 393 /* 394 * Giant lock manipulation and clean exit macros. 395 * Used to replace return with an exit Giant and return. 396 * 397 * Note that DROP_GIANT*() needs to be paired with PICKUP_GIANT() 398 * The #ifndef is to allow lint-like tools to redefine DROP_GIANT. 399 */ 400 #ifndef DROP_GIANT 401 #define DROP_GIANT() \ 402 do { \ 403 int _giantcnt = 0; \ 404 WITNESS_SAVE_DECL(Giant); \ 405 \ 406 if (mtx_owned(&Giant)) { \ 407 WITNESS_SAVE(&Giant.lock_object, Giant); \ 408 for (_giantcnt = 0; mtx_owned(&Giant) && \ 409 !SCHEDULER_STOPPED(); _giantcnt++) \ 410 mtx_unlock(&Giant); \ 411 } 412 413 #define PICKUP_GIANT() \ 414 PARTIAL_PICKUP_GIANT(); \ 415 } while (0) 416 417 #define PARTIAL_PICKUP_GIANT() \ 418 mtx_assert(&Giant, MA_NOTOWNED); \ 419 if (_giantcnt > 0) { \ 420 while (_giantcnt--) \ 421 mtx_lock(&Giant); \ 422 WITNESS_RESTORE(&Giant.lock_object, Giant); \ 423 } 424 #endif 425 426 struct mtx_args { 427 void *ma_mtx; 428 const char *ma_desc; 429 int ma_opts; 430 }; 431 432 #define MTX_SYSINIT(name, mtx, desc, opts) \ 433 static struct mtx_args name##_args = { \ 434 (mtx), \ 435 (desc), \ 436 (opts) \ 437 }; \ 438 SYSINIT(name##_mtx_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ 439 mtx_sysinit, &name##_args); \ 440 SYSUNINIT(name##_mtx_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ 441 _mtx_destroy, __DEVOLATILE(void *, &(mtx)->mtx_lock)) 442 443 /* 444 * The INVARIANTS-enabled mtx_assert() functionality. 445 * 446 * The constants need to be defined for INVARIANT_SUPPORT infrastructure 447 * support as _mtx_assert() itself uses them and the latter implies that 448 * _mtx_assert() must build. 449 */ 450 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 451 #define MA_OWNED LA_XLOCKED 452 #define MA_NOTOWNED LA_UNLOCKED 453 #define MA_RECURSED LA_RECURSED 454 #define MA_NOTRECURSED LA_NOTRECURSED 455 #endif 456 457 /* 458 * Common lock type names. 459 */ 460 #define MTX_NETWORK_LOCK "network driver" 461 462 #endif /* _KERNEL */ 463 #endif /* _SYS_MUTEX_H_ */ 464