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