1 /*- 2 * SPDX-License-Identifier: BSD-2-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 31 */ 32 33 #ifndef _SYS_LOCK_H_ 34 #define _SYS_LOCK_H_ 35 36 #include <sys/queue.h> 37 #include <sys/_lock.h> 38 #include <sys/ktr_class.h> 39 40 struct lock_list_entry; 41 struct thread; 42 43 /* 44 * Lock classes. Each lock has a class which describes characteristics 45 * common to all types of locks of a given class. 46 * 47 * Spin locks in general must always protect against preemption, as it is 48 * an error to perform any type of context switch while holding a spin lock. 49 * Also, for an individual lock to be recursable, its class must allow 50 * recursion and the lock itself must explicitly allow recursion. 51 * 52 * The 'lc_ddb_show' function pointer is used to dump class-specific 53 * data for the 'show lock' DDB command. The 'lc_lock' and 54 * 'lc_unlock' function pointers are used in sleep(9) and cv_wait(9) 55 * to lock and unlock locks while blocking on a sleep queue. The 56 * return value of 'lc_unlock' will be passed to 'lc_lock' on resume 57 * to allow communication of state between the two routines. 58 */ 59 60 struct lock_class { 61 const char *lc_name; 62 u_int lc_flags; 63 void (*lc_assert)(const struct lock_object *lock, int what); 64 void (*lc_ddb_show)(const struct lock_object *lock); 65 void (*lc_lock)(struct lock_object *lock, uintptr_t how); 66 int (*lc_owner)(const struct lock_object *lock, 67 struct thread **owner); 68 uintptr_t (*lc_unlock)(struct lock_object *lock); 69 int (*lc_trylock)(struct lock_object *lock, uintptr_t how); 70 }; 71 72 #define LC_SLEEPLOCK 0x00000001 /* Sleep lock. */ 73 #define LC_SPINLOCK 0x00000002 /* Spin lock. */ 74 #define LC_SLEEPABLE 0x00000004 /* Sleeping allowed with this lock. */ 75 #define LC_RECURSABLE 0x00000008 /* Locks of this type may recurse. */ 76 #define LC_UPGRADABLE 0x00000010 /* Upgrades and downgrades permitted. */ 77 78 #define LO_CLASSFLAGS 0x0000ffff /* Class specific flags. */ 79 #define LO_INITIALIZED 0x00010000 /* Lock has been initialized. */ 80 #define LO_WITNESS 0x00020000 /* Should witness monitor this lock. */ 81 #define LO_QUIET 0x00040000 /* Don't log locking operations. */ 82 #define LO_RECURSABLE 0x00080000 /* Lock may recurse. */ 83 #define LO_SLEEPABLE 0x00100000 /* Lock may be held while sleeping. */ 84 #define LO_UPGRADABLE 0x00200000 /* Lock may be upgraded/downgraded. */ 85 #define LO_DUPOK 0x00400000 /* Don't check for duplicate acquires */ 86 #define LO_IS_VNODE 0x00800000 /* Tell WITNESS about a VNODE lock */ 87 #define LO_CLASSMASK 0x0f000000 /* Class index bitmask. */ 88 #define LO_NOPROFILE 0x10000000 /* Don't profile this lock */ 89 #define LO_NEW 0x20000000 /* Don't check for double-init */ 90 91 /* 92 * Lock classes are statically assigned an index into the gobal lock_classes 93 * array. Debugging code looks up the lock class for a given lock object 94 * by indexing the array. 95 */ 96 #define LO_CLASSSHIFT 24 97 #define LO_CLASSINDEX(lock) ((((lock)->lo_flags) & LO_CLASSMASK) >> LO_CLASSSHIFT) 98 #define LOCK_CLASS(lock) (lock_classes[LO_CLASSINDEX((lock))]) 99 #define LOCK_CLASS_MAX (LO_CLASSMASK >> LO_CLASSSHIFT) 100 101 /* 102 * Option flags passed to lock operations that witness also needs to know 103 * about or that are generic across all locks. 104 */ 105 #define LOP_NEWORDER 0x00000001 /* Define a new lock order. */ 106 #define LOP_QUIET 0x00000002 /* Don't log locking operations. */ 107 #define LOP_TRYLOCK 0x00000004 /* Don't check lock order. */ 108 #define LOP_EXCLUSIVE 0x00000008 /* Exclusive lock. */ 109 #define LOP_DUPOK 0x00000010 /* Don't check for duplicate acquires */ 110 #define LOP_NOSLEEP 0x00000020 /* Non-sleepable despite LO_SLEEPABLE */ 111 112 /* Flags passed to witness_assert. */ 113 #define LA_MASKASSERT 0x000000ff /* Mask for witness defined asserts. */ 114 #define LA_UNLOCKED 0x00000000 /* Lock is unlocked. */ 115 #define LA_LOCKED 0x00000001 /* Lock is at least share locked. */ 116 #define LA_SLOCKED 0x00000002 /* Lock is exactly share locked. */ 117 #define LA_XLOCKED 0x00000004 /* Lock is exclusively locked. */ 118 #define LA_RECURSED 0x00000008 /* Lock is recursed. */ 119 #define LA_NOTRECURSED 0x00000010 /* Lock is not recursed. */ 120 121 #ifdef _KERNEL 122 /* 123 * Macros for KTR_LOCK tracing. 124 * 125 * opname - name of this operation (LOCK/UNLOCK/SLOCK, etc.) 126 * lo - struct lock_object * for this lock 127 * flags - flags passed to the lock operation 128 * recurse - this locks recursion level (or 0 if class is not recursable) 129 * result - result of a try lock operation 130 * file - file name 131 * line - line number 132 */ 133 #if LOCK_DEBUG > 0 134 #define LOCK_LOG_TEST(lo, flags) \ 135 (((flags) & LOP_QUIET) == 0 && ((lo)->lo_flags & LO_QUIET) == 0) 136 #else 137 #define LOCK_LOG_TEST(lo, flags) 0 138 #endif 139 140 #define LOCK_LOG_LOCK(opname, lo, flags, recurse, file, line) do { \ 141 if (LOCK_LOG_TEST((lo), (flags))) \ 142 CTR6(KTR_LOCK, opname " (%s) %s %p r = %d at %s:%d", \ 143 LOCK_CLASS(lo)->lc_name, (lo)->lo_name, \ 144 (lo), (u_int)(recurse), (file), (line)); \ 145 } while (0) 146 147 #define LOCK_LOG_TRY(opname, lo, flags, result, file, line) do { \ 148 if (LOCK_LOG_TEST((lo), (flags))) \ 149 CTR6(KTR_LOCK, "TRY_" opname " (%s) %s %p result=%d at %s:%d",\ 150 LOCK_CLASS(lo)->lc_name, (lo)->lo_name, \ 151 (lo), (u_int)(result), (file), (line)); \ 152 } while (0) 153 154 #define LOCK_LOG_INIT(lo, flags) do { \ 155 if (LOCK_LOG_TEST((lo), (flags))) \ 156 CTR4(KTR_LOCK, "%s: %p (%s) %s", __func__, (lo), \ 157 LOCK_CLASS(lo)->lc_name, (lo)->lo_name); \ 158 } while (0) 159 160 #define LOCK_LOG_DESTROY(lo, flags) LOCK_LOG_INIT(lo, flags) 161 162 #define lock_initialized(lo) ((lo)->lo_flags & LO_INITIALIZED) 163 164 /* 165 * The lk2lo() macro is used to extract lock_object from various lock types 166 * that embed lock_object for purpose of writing a _Generic() macro that would 167 * allow to create a single KPI for different kinds of locks. 168 * The NOLOCK is lock-typed NULL pointer, to be used as no-lock argument in 169 * such _Generic() macros. 170 */ 171 #define lk2lo(lk) (&(lk)->lock_object) 172 #define NOLOCK ((struct mtx *)0) 173 174 extern struct lock_class lock_class_mtx_sleep; 175 extern struct lock_class lock_class_mtx_spin; 176 extern struct lock_class lock_class_sx; 177 extern struct lock_class lock_class_rw; 178 extern struct lock_class lock_class_rm; 179 extern struct lock_class lock_class_rm_sleepable; 180 extern struct lock_class lock_class_lockmgr; 181 182 extern struct lock_class *lock_classes[]; 183 184 struct lock_delay_config { 185 u_short base; 186 u_short max; 187 }; 188 189 extern struct lock_delay_config locks_delay; 190 extern u_short locks_delay_retries; 191 extern u_short locks_delay_loops; 192 193 struct lock_delay_arg { 194 struct lock_delay_config *config; 195 u_int delay; 196 u_int spin_cnt; 197 }; 198 199 static inline void 200 lock_delay_arg_init(struct lock_delay_arg *la, struct lock_delay_config *lc) 201 { 202 la->config = lc; 203 la->delay = lc->base; 204 la->spin_cnt = 0; 205 } 206 207 static inline void 208 lock_delay_arg_init_noadapt(struct lock_delay_arg *la) 209 { 210 la->delay = 0; 211 la->spin_cnt = 0; 212 } 213 214 #define lock_delay_spin(n) do { \ 215 u_int _i; \ 216 \ 217 for (_i = (n); _i > 0; _i--) \ 218 cpu_spinwait(); \ 219 } while (0) 220 221 #define LOCK_DELAY_SYSINIT(func) \ 222 SYSINIT(func##_ld, SI_SUB_LOCK, SI_ORDER_ANY, func, NULL) 223 224 #define LOCK_DELAY_SYSINIT_DEFAULT(lc) \ 225 SYSINIT(lock_delay_##lc##_ld, SI_SUB_LOCK, SI_ORDER_ANY, \ 226 lock_delay_default_init, &lc) 227 228 void lock_init(struct lock_object *, struct lock_class *, 229 const char *, const char *, int); 230 void lock_destroy(struct lock_object *); 231 void lock_delay(struct lock_delay_arg *); 232 void lock_delay_default_init(struct lock_delay_config *); 233 void spinlock_enter(void); 234 void spinlock_exit(void); 235 void witness_init(struct lock_object *, const char *); 236 void witness_destroy(struct lock_object *); 237 int witness_defineorder(struct lock_object *, struct lock_object *); 238 void witness_checkorder(struct lock_object *, int, const char *, int, 239 struct lock_object *); 240 void witness_lock(struct lock_object *, int, const char *, int); 241 void witness_upgrade(struct lock_object *, int, const char *, int); 242 void witness_downgrade(struct lock_object *, int, const char *, int); 243 void witness_unlock(struct lock_object *, int, const char *, int); 244 void witness_save(struct lock_object *, const char **, int *); 245 void witness_restore(struct lock_object *, const char *, int); 246 int witness_list_locks(struct lock_list_entry **, 247 int (*)(const char *, ...)); 248 int witness_warn(int, struct lock_object *, const char *, ...); 249 void witness_assert(const struct lock_object *, int, const char *, int); 250 int witness_is_owned(const struct lock_object *lock); 251 void witness_display_spinlock(struct lock_object *, struct thread *, 252 int (*)(const char *, ...)); 253 int witness_line(struct lock_object *); 254 void witness_norelease(struct lock_object *); 255 void witness_releaseok(struct lock_object *); 256 const char *witness_file(struct lock_object *); 257 void witness_thread_exit(struct thread *); 258 259 #ifdef WITNESS 260 u_long witness_startup_count(u_long); 261 void witness_startup(void *); 262 263 /* Flags for witness_warn(). */ 264 #define WARN_GIANTOK 0x01 /* Giant is exempt from this check. */ 265 #define WARN_PANIC 0x02 /* Panic if check fails. */ 266 #define WARN_SLEEPOK 0x04 /* Sleepable locks are exempt from check. */ 267 268 #define WITNESS_INIT(lock, type) \ 269 witness_init((lock), (type)) 270 271 #define WITNESS_DESTROY(lock) \ 272 witness_destroy(lock) 273 274 #define WITNESS_CHECKORDER(lock, flags, file, line, interlock) \ 275 witness_checkorder((lock), (flags), (file), (line), (interlock)) 276 277 #define WITNESS_DEFINEORDER(lock1, lock2) \ 278 witness_defineorder((struct lock_object *)(lock1), \ 279 (struct lock_object *)(lock2)) 280 281 #define WITNESS_LOCK(lock, flags, file, line) \ 282 witness_lock((lock), (flags), (file), (line)) 283 284 #define WITNESS_UPGRADE(lock, flags, file, line) \ 285 witness_upgrade((lock), (flags), (file), (line)) 286 287 #define WITNESS_DOWNGRADE(lock, flags, file, line) \ 288 witness_downgrade((lock), (flags), (file), (line)) 289 290 #define WITNESS_UNLOCK(lock, flags, file, line) \ 291 witness_unlock((lock), (flags), (file), (line)) 292 293 #define WITNESS_CHECK(flags, lock, fmt, ...) \ 294 witness_warn((flags), (lock), (fmt), ## __VA_ARGS__) 295 296 #define WITNESS_WARN(flags, lock, fmt, ...) \ 297 witness_warn((flags), (lock), (fmt), ## __VA_ARGS__) 298 299 #define WITNESS_SAVE_DECL(n) \ 300 const char * __CONCAT(n, __wf); \ 301 int __CONCAT(n, __wl) 302 303 #define WITNESS_SAVE(lock, n) \ 304 witness_save((lock), &__CONCAT(n, __wf), &__CONCAT(n, __wl)) 305 306 #define WITNESS_RESTORE(lock, n) \ 307 witness_restore((lock), __CONCAT(n, __wf), __CONCAT(n, __wl)) 308 309 #define WITNESS_NORELEASE(lock) \ 310 witness_norelease(&(lock)->lock_object) 311 312 #define WITNESS_RELEASEOK(lock) \ 313 witness_releaseok(&(lock)->lock_object) 314 315 #define WITNESS_FILE(lock) \ 316 witness_file(lock) 317 318 #define WITNESS_LINE(lock) \ 319 witness_line(lock) 320 321 #else /* WITNESS */ 322 #define WITNESS_INIT(lock, type) (void)0 323 #define WITNESS_DESTROY(lock) (void)0 324 #define WITNESS_DEFINEORDER(lock1, lock2) 0 325 #define WITNESS_CHECKORDER(lock, flags, file, line, interlock) (void)0 326 #define WITNESS_LOCK(lock, flags, file, line) (void)0 327 #define WITNESS_UPGRADE(lock, flags, file, line) (void)0 328 #define WITNESS_DOWNGRADE(lock, flags, file, line) (void)0 329 #define WITNESS_UNLOCK(lock, flags, file, line) (void)0 330 #define WITNESS_CHECK(flags, lock, fmt, ...) 0 331 #define WITNESS_WARN(flags, lock, fmt, ...) (void)0 332 #define WITNESS_SAVE_DECL(n) (void)0 333 #define WITNESS_SAVE(lock, n) (void)0 334 #define WITNESS_RESTORE(lock, n) (void)0 335 #define WITNESS_NORELEASE(lock) (void)0 336 #define WITNESS_RELEASEOK(lock) (void)0 337 #define WITNESS_FILE(lock) ("?") 338 #define WITNESS_LINE(lock) (0) 339 #endif /* WITNESS */ 340 341 #endif /* _KERNEL */ 342 #endif /* _SYS_LOCK_H_ */ 343