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 #ifndef LOCORE 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 <machine/atomic.h> 44 #include <machine/cpufunc.h> 45 #endif /* _KERNEL_ */ 46 #endif /* !LOCORE */ 47 48 #include <machine/mutex.h> 49 50 #ifdef _KERNEL 51 52 /* 53 * Mutex types and options passed to mtx_init(). MTX_QUIET and MTX_DUPOK 54 * can also be passed in. 55 */ 56 #define MTX_DEF 0x00000000 /* DEFAULT (sleep) lock */ 57 #define MTX_SPIN 0x00000001 /* Spin lock (disables interrupts) */ 58 #define MTX_RECURSE 0x00000004 /* Option: lock allowed to recurse */ 59 #define MTX_NOWITNESS 0x00000008 /* Don't do any witness checking. */ 60 #define MTX_NOPROFILE 0x00000020 /* Don't profile this lock */ 61 62 /* 63 * Option flags passed to certain lock/unlock routines, through the use 64 * of corresponding mtx_{lock,unlock}_flags() interface macros. 65 */ 66 #define MTX_QUIET LOP_QUIET /* Don't log a mutex event */ 67 #define MTX_DUPOK LOP_DUPOK /* Don't log a duplicate acquire */ 68 69 /* 70 * State bits kept in mutex->mtx_lock, for the DEFAULT lock type. None of this, 71 * with the exception of MTX_UNOWNED, applies to spin locks. 72 */ 73 #define MTX_RECURSED 0x00000001 /* lock recursed (for MTX_DEF only) */ 74 #define MTX_CONTESTED 0x00000002 /* lock contested (for MTX_DEF only) */ 75 #define MTX_UNOWNED 0x00000004 /* Cookie for free mutex */ 76 #define MTX_FLAGMASK (MTX_RECURSED | MTX_CONTESTED | MTX_UNOWNED) 77 78 /* 79 * Value stored in mutex->mtx_lock to denote a destroyed mutex. 80 */ 81 #define MTX_DESTROYED (MTX_CONTESTED | MTX_UNOWNED) 82 83 #endif /* _KERNEL */ 84 85 #ifndef LOCORE 86 87 /* 88 * XXX: Friendly reminder to fix things in MP code that is presently being 89 * XXX: worked on. 90 */ 91 #define mp_fixme(string) 92 93 #ifdef _KERNEL 94 95 /* 96 * Prototypes 97 * 98 * NOTE: Functions prepended with `_' (underscore) are exported to other parts 99 * of the kernel via macros, thus allowing us to use the cpp LOCK_FILE 100 * and LOCK_LINE. These functions should not be called directly by any 101 * code using the API. Their macros cover their functionality. 102 * 103 * [See below for descriptions] 104 * 105 */ 106 void mtx_init(struct mtx *m, const char *name, const char *type, int opts); 107 void mtx_destroy(struct mtx *m); 108 void mtx_sysinit(void *arg); 109 void mutex_init(void); 110 void _mtx_lock_sleep(struct mtx *m, uintptr_t tid, int opts, 111 const char *file, int line); 112 void _mtx_unlock_sleep(struct mtx *m, int opts, const char *file, int line); 113 #ifdef SMP 114 void _mtx_lock_spin(struct mtx *m, uintptr_t tid, int opts, 115 const char *file, int line); 116 #endif 117 void _mtx_unlock_spin(struct mtx *m, int opts, const char *file, int line); 118 int _mtx_trylock(struct mtx *m, int opts, const char *file, int line); 119 void _mtx_lock_flags(struct mtx *m, int opts, const char *file, int line); 120 void _mtx_unlock_flags(struct mtx *m, int opts, const char *file, int line); 121 void _mtx_lock_spin_flags(struct mtx *m, int opts, const char *file, 122 int line); 123 void _mtx_unlock_spin_flags(struct mtx *m, int opts, const char *file, 124 int line); 125 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 126 void _mtx_assert(struct mtx *m, int what, const char *file, int line); 127 #endif 128 void _thread_lock_flags(struct thread *, int, const char *, int); 129 130 #define thread_lock(tdp) \ 131 _thread_lock_flags((tdp), 0, __FILE__, __LINE__) 132 #define thread_lock_flags(tdp, opt) \ 133 _thread_lock_flags((tdp), (opt), __FILE__, __LINE__) 134 #define thread_unlock(tdp) \ 135 mtx_unlock_spin((tdp)->td_lock) 136 137 #define mtx_recurse lock_object.lo_data 138 139 /* 140 * We define our machine-independent (unoptimized) mutex micro-operations 141 * here, if they are not already defined in the machine-dependent mutex.h 142 */ 143 144 /* Try to obtain mtx_lock once. */ 145 #ifndef _obtain_lock 146 #define _obtain_lock(mp, tid) \ 147 atomic_cmpset_acq_ptr(&(mp)->mtx_lock, MTX_UNOWNED, (tid)) 148 #endif 149 150 /* Try to release mtx_lock if it is unrecursed and uncontested. */ 151 #ifndef _release_lock 152 #define _release_lock(mp, tid) \ 153 atomic_cmpset_rel_ptr(&(mp)->mtx_lock, (tid), MTX_UNOWNED) 154 #endif 155 156 /* Release mtx_lock quickly, assuming we own it. */ 157 #ifndef _release_lock_quick 158 #define _release_lock_quick(mp) \ 159 atomic_store_rel_ptr(&(mp)->mtx_lock, MTX_UNOWNED) 160 #endif 161 162 /* 163 * Obtain a sleep lock inline, or call the "hard" function if we can't get it 164 * easy. 165 */ 166 #ifndef _get_sleep_lock 167 #define _get_sleep_lock(mp, tid, opts, file, line) do { \ 168 uintptr_t _tid = (uintptr_t)(tid); \ 169 if (!_obtain_lock((mp), _tid)) { \ 170 _mtx_lock_sleep((mp), _tid, (opts), (file), (line)); \ 171 } else \ 172 lock_profile_obtain_lock_success(&(mp)->lock_object, 0, \ 173 0, (file), (line)); \ 174 } while (0) 175 #endif 176 177 /* 178 * Obtain a spin lock inline, or call the "hard" function if we can't get it 179 * easy. For spinlocks, we handle recursion inline (it turns out that function 180 * calls can be significantly expensive on some architectures). 181 * Since spin locks are not _too_ common, inlining this code is not too big 182 * a deal. 183 */ 184 #ifndef _get_spin_lock 185 #ifdef SMP 186 #define _get_spin_lock(mp, tid, opts, file, line) do { \ 187 uintptr_t _tid = (uintptr_t)(tid); \ 188 spinlock_enter(); \ 189 if (!_obtain_lock((mp), _tid)) { \ 190 if ((mp)->mtx_lock == _tid) \ 191 (mp)->mtx_recurse++; \ 192 else { \ 193 _mtx_lock_spin((mp), _tid, (opts), (file), (line)); \ 194 } \ 195 } else \ 196 lock_profile_obtain_lock_success(&(mp)->lock_object, 0, \ 197 0, (file), (line)); \ 198 } while (0) 199 #else /* SMP */ 200 #define _get_spin_lock(mp, tid, opts, file, line) do { \ 201 uintptr_t _tid = (uintptr_t)(tid); \ 202 \ 203 spinlock_enter(); \ 204 if ((mp)->mtx_lock == _tid) \ 205 (mp)->mtx_recurse++; \ 206 else { \ 207 KASSERT((mp)->mtx_lock == MTX_UNOWNED, ("corrupt spinlock")); \ 208 (mp)->mtx_lock = _tid; \ 209 } \ 210 } while (0) 211 #endif /* SMP */ 212 #endif 213 214 /* 215 * Release a sleep lock inline, or call the "hard" function if we can't do it 216 * easy. 217 */ 218 #ifndef _rel_sleep_lock 219 #define _rel_sleep_lock(mp, tid, opts, file, line) do { \ 220 uintptr_t _tid = (uintptr_t)(tid); \ 221 \ 222 if (!_release_lock((mp), _tid)) \ 223 _mtx_unlock_sleep((mp), (opts), (file), (line)); \ 224 } while (0) 225 #endif 226 227 /* 228 * For spinlocks, we can handle everything inline, as it's pretty simple and 229 * a function call would be too expensive (at least on some architectures). 230 * Since spin locks are not _too_ common, inlining this code is not too big 231 * a deal. 232 * 233 * Since we always perform a spinlock_enter() when attempting to acquire a 234 * spin lock, we need to always perform a matching spinlock_exit() when 235 * releasing a spin lock. This includes the recursion cases. 236 */ 237 #ifndef _rel_spin_lock 238 #ifdef SMP 239 #define _rel_spin_lock(mp) do { \ 240 if (mtx_recursed((mp))) \ 241 (mp)->mtx_recurse--; \ 242 else { \ 243 lock_profile_release_lock(&(mp)->lock_object); \ 244 _release_lock_quick((mp)); \ 245 } \ 246 spinlock_exit(); \ 247 } while (0) 248 #else /* SMP */ 249 #define _rel_spin_lock(mp) do { \ 250 if (mtx_recursed((mp))) \ 251 (mp)->mtx_recurse--; \ 252 else \ 253 (mp)->mtx_lock = MTX_UNOWNED; \ 254 spinlock_exit(); \ 255 } while (0) 256 #endif /* SMP */ 257 #endif 258 259 /* 260 * Exported lock manipulation interface. 261 * 262 * mtx_lock(m) locks MTX_DEF mutex `m' 263 * 264 * mtx_lock_spin(m) locks MTX_SPIN mutex `m' 265 * 266 * mtx_unlock(m) unlocks MTX_DEF mutex `m' 267 * 268 * mtx_unlock_spin(m) unlocks MTX_SPIN mutex `m' 269 * 270 * mtx_lock_spin_flags(m, opts) and mtx_lock_flags(m, opts) locks mutex `m' 271 * and passes option flags `opts' to the "hard" function, if required. 272 * With these routines, it is possible to pass flags such as MTX_QUIET 273 * to the appropriate lock manipulation routines. 274 * 275 * mtx_trylock(m) attempts to acquire MTX_DEF mutex `m' but doesn't sleep if 276 * it cannot. Rather, it returns 0 on failure and non-zero on success. 277 * It does NOT handle recursion as we assume that if a caller is properly 278 * using this part of the interface, he will know that the lock in question 279 * is _not_ recursed. 280 * 281 * mtx_trylock_flags(m, opts) is used the same way as mtx_trylock() but accepts 282 * relevant option flags `opts.' 283 * 284 * mtx_initialized(m) returns non-zero if the lock `m' has been initialized. 285 * 286 * mtx_owned(m) returns non-zero if the current thread owns the lock `m' 287 * 288 * mtx_recursed(m) returns non-zero if the lock `m' is presently recursed. 289 */ 290 #define mtx_lock(m) mtx_lock_flags((m), 0) 291 #define mtx_lock_spin(m) mtx_lock_spin_flags((m), 0) 292 #define mtx_trylock(m) mtx_trylock_flags((m), 0) 293 #define mtx_unlock(m) mtx_unlock_flags((m), 0) 294 #define mtx_unlock_spin(m) mtx_unlock_spin_flags((m), 0) 295 296 struct mtx_pool; 297 298 struct mtx_pool *mtx_pool_create(const char *mtx_name, int pool_size, int opts); 299 void mtx_pool_destroy(struct mtx_pool **poolp); 300 struct mtx *mtx_pool_find(struct mtx_pool *pool, void *ptr); 301 struct mtx *mtx_pool_alloc(struct mtx_pool *pool); 302 #define mtx_pool_lock(pool, ptr) \ 303 mtx_lock(mtx_pool_find((pool), (ptr))) 304 #define mtx_pool_lock_spin(pool, ptr) \ 305 mtx_lock_spin(mtx_pool_find((pool), (ptr))) 306 #define mtx_pool_unlock(pool, ptr) \ 307 mtx_unlock(mtx_pool_find((pool), (ptr))) 308 #define mtx_pool_unlock_spin(pool, ptr) \ 309 mtx_unlock_spin(mtx_pool_find((pool), (ptr))) 310 311 /* 312 * mtxpool_lockbuilder is a pool of sleep locks that is not witness 313 * checked and should only be used for building higher level locks. 314 * 315 * mtxpool_sleep is a general purpose pool of sleep mutexes. 316 */ 317 extern struct mtx_pool *mtxpool_lockbuilder; 318 extern struct mtx_pool *mtxpool_sleep; 319 320 #ifndef LOCK_DEBUG 321 #error LOCK_DEBUG not defined, include <sys/lock.h> before <sys/mutex.h> 322 #endif 323 #if LOCK_DEBUG > 0 || defined(MUTEX_NOINLINE) 324 #define mtx_lock_flags(m, opts) \ 325 _mtx_lock_flags((m), (opts), LOCK_FILE, LOCK_LINE) 326 #define mtx_unlock_flags(m, opts) \ 327 _mtx_unlock_flags((m), (opts), LOCK_FILE, LOCK_LINE) 328 #define mtx_lock_spin_flags(m, opts) \ 329 _mtx_lock_spin_flags((m), (opts), LOCK_FILE, LOCK_LINE) 330 #define mtx_unlock_spin_flags(m, opts) \ 331 _mtx_unlock_spin_flags((m), (opts), LOCK_FILE, LOCK_LINE) 332 #else /* LOCK_DEBUG == 0 && !MUTEX_NOINLINE */ 333 #define mtx_lock_flags(m, opts) \ 334 _get_sleep_lock((m), curthread, (opts), LOCK_FILE, LOCK_LINE) 335 #define mtx_unlock_flags(m, opts) \ 336 _rel_sleep_lock((m), curthread, (opts), LOCK_FILE, LOCK_LINE) 337 #define mtx_lock_spin_flags(m, opts) \ 338 _get_spin_lock((m), curthread, (opts), LOCK_FILE, LOCK_LINE) 339 #define mtx_unlock_spin_flags(m, opts) \ 340 _rel_spin_lock((m)) 341 #endif /* LOCK_DEBUG > 0 || MUTEX_NOINLINE */ 342 343 #define mtx_trylock_flags(m, opts) \ 344 _mtx_trylock((m), (opts), LOCK_FILE, LOCK_LINE) 345 346 #define mtx_sleep(chan, mtx, pri, wmesg, timo) \ 347 _sleep((chan), &(mtx)->lock_object, (pri), (wmesg), (timo)) 348 349 #define mtx_initialized(m) lock_initalized(&(m)->lock_object) 350 351 #define mtx_owned(m) (((m)->mtx_lock & ~MTX_FLAGMASK) == (uintptr_t)curthread) 352 353 #define mtx_recursed(m) ((m)->mtx_recurse != 0) 354 355 #define mtx_name(m) ((m)->lock_object.lo_name) 356 357 /* 358 * Global locks. 359 */ 360 extern struct mtx Giant; 361 extern struct mtx blocked_lock; 362 363 /* 364 * Giant lock manipulation and clean exit macros. 365 * Used to replace return with an exit Giant and return. 366 * 367 * Note that DROP_GIANT*() needs to be paired with PICKUP_GIANT() 368 * The #ifndef is to allow lint-like tools to redefine DROP_GIANT. 369 */ 370 #ifndef DROP_GIANT 371 #define DROP_GIANT() \ 372 do { \ 373 int _giantcnt = 0; \ 374 WITNESS_SAVE_DECL(Giant); \ 375 \ 376 if (mtx_owned(&Giant)) { \ 377 WITNESS_SAVE(&Giant.lock_object, Giant); \ 378 for (_giantcnt = 0; mtx_owned(&Giant); _giantcnt++) \ 379 mtx_unlock(&Giant); \ 380 } 381 382 #define PICKUP_GIANT() \ 383 PARTIAL_PICKUP_GIANT(); \ 384 } while (0) 385 386 #define PARTIAL_PICKUP_GIANT() \ 387 mtx_assert(&Giant, MA_NOTOWNED); \ 388 if (_giantcnt > 0) { \ 389 while (_giantcnt--) \ 390 mtx_lock(&Giant); \ 391 WITNESS_RESTORE(&Giant.lock_object, Giant); \ 392 } 393 #endif 394 395 #define UGAR(rval) do { \ 396 int _val = (rval); \ 397 mtx_unlock(&Giant); \ 398 return (_val); \ 399 } while (0) 400 401 struct mtx_args { 402 struct mtx *ma_mtx; 403 const char *ma_desc; 404 int ma_opts; 405 }; 406 407 #define MTX_SYSINIT(name, mtx, desc, opts) \ 408 static struct mtx_args name##_args = { \ 409 (mtx), \ 410 (desc), \ 411 (opts) \ 412 }; \ 413 SYSINIT(name##_mtx_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ 414 mtx_sysinit, &name##_args); \ 415 SYSUNINIT(name##_mtx_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ 416 mtx_destroy, (mtx)) 417 418 /* 419 * The INVARIANTS-enabled mtx_assert() functionality. 420 * 421 * The constants need to be defined for INVARIANT_SUPPORT infrastructure 422 * support as _mtx_assert() itself uses them and the latter implies that 423 * _mtx_assert() must build. 424 */ 425 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 426 #define MA_OWNED LA_XLOCKED 427 #define MA_NOTOWNED LA_UNLOCKED 428 #define MA_RECURSED LA_RECURSED 429 #define MA_NOTRECURSED LA_NOTRECURSED 430 #endif 431 432 #ifdef INVARIANTS 433 #define mtx_assert(m, what) \ 434 _mtx_assert((m), (what), __FILE__, __LINE__) 435 436 #define GIANT_REQUIRED mtx_assert(&Giant, MA_OWNED) 437 438 #else /* INVARIANTS */ 439 #define mtx_assert(m, what) 440 #define GIANT_REQUIRED 441 #endif /* INVARIANTS */ 442 443 /* 444 * Common lock type names. 445 */ 446 #define MTX_NETWORK_LOCK "network driver" 447 448 #endif /* _KERNEL */ 449 #endif /* !LOCORE */ 450 #endif /* _SYS_MUTEX_H_ */ 451