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
29 * $FreeBSD$
30 */
31
32 #ifndef _SYS_LOCK_H_
33 #define _SYS_LOCK_H_
34
35 #include <sys/queue.h>
36 #include <sys/_lock.h>
37 #include <sys/ktr_class.h>
38
39 struct lock_list_entry;
40 struct thread;
41
42 /*
43 * Lock classes. Each lock has a class which describes characteristics
44 * common to all types of locks of a given class.
45 *
46 * Spin locks in general must always protect against preemption, as it is
47 * an error to perform any type of context switch while holding a spin lock.
48 * Also, for an individual lock to be recursable, its class must allow
49 * recursion and the lock itself must explicitly allow recursion.
50 *
51 * The 'lc_ddb_show' function pointer is used to dump class-specific
52 * data for the 'show lock' DDB command. The 'lc_lock' and
53 * 'lc_unlock' function pointers are used in sleep(9) and cv_wait(9)
54 * to lock and unlock locks while blocking on a sleep queue. The
55 * return value of 'lc_unlock' will be passed to 'lc_lock' on resume
56 * to allow communication of state between the two routines.
57 */
58
59 struct lock_class {
60 const char *lc_name;
61 u_int lc_flags;
62 void (*lc_assert)(const struct lock_object *lock, int what);
63 void (*lc_ddb_show)(const struct lock_object *lock);
64 void (*lc_lock)(struct lock_object *lock, uintptr_t how);
65 int (*lc_owner)(const struct lock_object *lock,
66 struct thread **owner);
67 uintptr_t (*lc_unlock)(struct lock_object *lock);
68 };
69
70 #define LC_SLEEPLOCK 0x00000001 /* Sleep lock. */
71 #define LC_SPINLOCK 0x00000002 /* Spin lock. */
72 #define LC_SLEEPABLE 0x00000004 /* Sleeping allowed with this lock. */
73 #define LC_RECURSABLE 0x00000008 /* Locks of this type may recurse. */
74 #define LC_UPGRADABLE 0x00000010 /* Upgrades and downgrades permitted. */
75
76 #define LO_CLASSFLAGS 0x0000ffff /* Class specific flags. */
77 #define LO_INITIALIZED 0x00010000 /* Lock has been initialized. */
78 #define LO_WITNESS 0x00020000 /* Should witness monitor this lock. */
79 #define LO_QUIET 0x00040000 /* Don't log locking operations. */
80 #define LO_RECURSABLE 0x00080000 /* Lock may recurse. */
81 #define LO_SLEEPABLE 0x00100000 /* Lock may be held while sleeping. */
82 #define LO_UPGRADABLE 0x00200000 /* Lock may be upgraded/downgraded. */
83 #define LO_DUPOK 0x00400000 /* Don't check for duplicate acquires */
84 #define LO_IS_VNODE 0x00800000 /* Tell WITNESS about a VNODE lock */
85 #define LO_CLASSMASK 0x0f000000 /* Class index bitmask. */
86 #define LO_NOPROFILE 0x10000000 /* Don't profile this lock */
87 #define LO_NEW 0x20000000 /* Don't check for double-init */
88
89 /*
90 * Lock classes are statically assigned an index into the gobal lock_classes
91 * array. Debugging code looks up the lock class for a given lock object
92 * by indexing the array.
93 */
94 #define LO_CLASSSHIFT 24
95 #define LO_CLASSINDEX(lock) ((((lock)->lo_flags) & LO_CLASSMASK) >> LO_CLASSSHIFT)
96 #define LOCK_CLASS(lock) (lock_classes[LO_CLASSINDEX((lock))])
97 #define LOCK_CLASS_MAX (LO_CLASSMASK >> LO_CLASSSHIFT)
98
99 /*
100 * Option flags passed to lock operations that witness also needs to know
101 * about or that are generic across all locks.
102 */
103 #define LOP_NEWORDER 0x00000001 /* Define a new lock order. */
104 #define LOP_QUIET 0x00000002 /* Don't log locking operations. */
105 #define LOP_TRYLOCK 0x00000004 /* Don't check lock order. */
106 #define LOP_EXCLUSIVE 0x00000008 /* Exclusive lock. */
107 #define LOP_DUPOK 0x00000010 /* Don't check for duplicate acquires */
108
109 /* Flags passed to witness_assert. */
110 #define LA_MASKASSERT 0x000000ff /* Mask for witness defined asserts. */
111 #define LA_UNLOCKED 0x00000000 /* Lock is unlocked. */
112 #define LA_LOCKED 0x00000001 /* Lock is at least share locked. */
113 #define LA_SLOCKED 0x00000002 /* Lock is exactly share locked. */
114 #define LA_XLOCKED 0x00000004 /* Lock is exclusively locked. */
115 #define LA_RECURSED 0x00000008 /* Lock is recursed. */
116 #define LA_NOTRECURSED 0x00000010 /* Lock is not recursed. */
117
118 #ifdef _KERNEL
119 /*
120 * If any of WITNESS, INVARIANTS, or KTR_LOCK KTR tracing has been enabled,
121 * then turn on LOCK_DEBUG. When this option is on, extra debugging
122 * facilities such as tracking the file and line number of lock operations
123 * are enabled. Also, mutex locking operations are not inlined to avoid
124 * bloat from all the extra debugging code. We also have to turn on all the
125 * calling conventions for this debugging code in modules so that modules can
126 * work with both debug and non-debug kernels.
127 */
128 #if defined(KLD_MODULE) || defined(WITNESS) || defined(INVARIANTS) || \
129 defined(INVARIANT_SUPPORT) || defined(LOCK_PROFILING) || defined(KTR)
130 #define LOCK_DEBUG 1
131 #else
132 #define LOCK_DEBUG 0
133 #endif
134
135 /*
136 * In the LOCK_DEBUG case, use the filename and line numbers for debugging
137 * operations. Otherwise, use default values to avoid the unneeded bloat.
138 */
139 #if LOCK_DEBUG > 0
140 #define LOCK_FILE_LINE_ARG_DEF , const char *file, int line
141 #define LOCK_FILE_LINE_ARG , file, line
142 #define LOCK_FILE __FILE__
143 #define LOCK_LINE __LINE__
144 #else
145 #define LOCK_FILE_LINE_ARG_DEF
146 #define LOCK_FILE_LINE_ARG
147 #define LOCK_FILE NULL
148 #define LOCK_LINE 0
149 #endif
150
151 /*
152 * Macros for KTR_LOCK tracing.
153 *
154 * opname - name of this operation (LOCK/UNLOCK/SLOCK, etc.)
155 * lo - struct lock_object * for this lock
156 * flags - flags passed to the lock operation
157 * recurse - this locks recursion level (or 0 if class is not recursable)
158 * result - result of a try lock operation
159 * file - file name
160 * line - line number
161 */
162 #if LOCK_DEBUG > 0
163 #define LOCK_LOG_TEST(lo, flags) \
164 (((flags) & LOP_QUIET) == 0 && ((lo)->lo_flags & LO_QUIET) == 0)
165 #else
166 #define LOCK_LOG_TEST(lo, flags) 0
167 #endif
168
169
170 #define LOCK_LOG_LOCK(opname, lo, flags, recurse, file, line) do { \
171 if (LOCK_LOG_TEST((lo), (flags))) \
172 CTR6(KTR_LOCK, opname " (%s) %s %p r = %d at %s:%d", \
173 LOCK_CLASS(lo)->lc_name, (lo)->lo_name, \
174 (lo), (u_int)(recurse), (file), (line)); \
175 } while (0)
176
177 #define LOCK_LOG_TRY(opname, lo, flags, result, file, line) do { \
178 if (LOCK_LOG_TEST((lo), (flags))) \
179 CTR6(KTR_LOCK, "TRY_" opname " (%s) %s %p result=%d at %s:%d",\
180 LOCK_CLASS(lo)->lc_name, (lo)->lo_name, \
181 (lo), (u_int)(result), (file), (line)); \
182 } while (0)
183
184 #define LOCK_LOG_INIT(lo, flags) do { \
185 if (LOCK_LOG_TEST((lo), (flags))) \
186 CTR4(KTR_LOCK, "%s: %p (%s) %s", __func__, (lo), \
187 LOCK_CLASS(lo)->lc_name, (lo)->lo_name); \
188 } while (0)
189
190 #define LOCK_LOG_DESTROY(lo, flags) LOCK_LOG_INIT(lo, flags)
191
192 #define lock_initialized(lo) ((lo)->lo_flags & LO_INITIALIZED)
193
194 /*
195 * Helpful macros for quickly coming up with assertions with informative
196 * panic messages.
197 */
198 #define MPASS(ex) MPASS4(ex, #ex, __FILE__, __LINE__)
199 #define MPASS2(ex, what) MPASS4(ex, what, __FILE__, __LINE__)
200 #define MPASS3(ex, file, line) MPASS4(ex, #ex, file, line)
201 #define MPASS4(ex, what, file, line) \
202 KASSERT((ex), ("Assertion %s failed at %s:%d", what, file, line))
203
204 extern struct lock_class lock_class_mtx_sleep;
205 extern struct lock_class lock_class_mtx_spin;
206 extern struct lock_class lock_class_sx;
207 extern struct lock_class lock_class_rw;
208 extern struct lock_class lock_class_rm;
209 extern struct lock_class lock_class_rm_sleepable;
210 extern struct lock_class lock_class_lockmgr;
211
212 extern struct lock_class *lock_classes[];
213
214 struct lock_delay_config {
215 u_int base;
216 u_int max;
217 };
218
219 struct lock_delay_arg {
220 struct lock_delay_config *config;
221 u_int delay;
222 u_int spin_cnt;
223 };
224
225 static inline void
lock_delay_arg_init(struct lock_delay_arg * la,struct lock_delay_config * lc)226 lock_delay_arg_init(struct lock_delay_arg *la, struct lock_delay_config *lc)
227 {
228 la->config = lc;
229 la->delay = lc->base;
230 la->spin_cnt = 0;
231 }
232
233 #define lock_delay_spin(n) do { \
234 u_int _i; \
235 \
236 for (_i = (n); _i > 0; _i--) \
237 cpu_spinwait(); \
238 } while (0)
239
240 #define LOCK_DELAY_SYSINIT(func) \
241 SYSINIT(func##_ld, SI_SUB_LOCK, SI_ORDER_ANY, func, NULL)
242
243 #define LOCK_DELAY_SYSINIT_DEFAULT(lc) \
244 SYSINIT(lock_delay_##lc##_ld, SI_SUB_LOCK, SI_ORDER_ANY, \
245 lock_delay_default_init, &lc)
246
247 void lock_init(struct lock_object *, struct lock_class *,
248 const char *, const char *, int);
249 void lock_destroy(struct lock_object *);
250 void lock_delay(struct lock_delay_arg *);
251 void lock_delay_default_init(struct lock_delay_config *);
252 void spinlock_enter(void);
253 void spinlock_exit(void);
254 void witness_init(struct lock_object *, const char *);
255 void witness_destroy(struct lock_object *);
256 int witness_defineorder(struct lock_object *, struct lock_object *);
257 void witness_checkorder(struct lock_object *, int, const char *, int,
258 struct lock_object *);
259 void witness_lock(struct lock_object *, int, const char *, int);
260 void witness_upgrade(struct lock_object *, int, const char *, int);
261 void witness_downgrade(struct lock_object *, int, const char *, int);
262 void witness_unlock(struct lock_object *, int, const char *, int);
263 void witness_save(struct lock_object *, const char **, int *);
264 void witness_restore(struct lock_object *, const char *, int);
265 int witness_list_locks(struct lock_list_entry **,
266 int (*)(const char *, ...));
267 int witness_warn(int, struct lock_object *, const char *, ...);
268 void witness_assert(const struct lock_object *, int, const char *, int);
269 void witness_display_spinlock(struct lock_object *, struct thread *,
270 int (*)(const char *, ...));
271 int witness_line(struct lock_object *);
272 void witness_norelease(struct lock_object *);
273 void witness_releaseok(struct lock_object *);
274 const char *witness_file(struct lock_object *);
275 void witness_thread_exit(struct thread *);
276
277 #ifdef WITNESS
278
279 /* Flags for witness_warn(). */
280 #define WARN_GIANTOK 0x01 /* Giant is exempt from this check. */
281 #define WARN_PANIC 0x02 /* Panic if check fails. */
282 #define WARN_SLEEPOK 0x04 /* Sleepable locks are exempt from check. */
283
284 #define WITNESS_INIT(lock, type) \
285 witness_init((lock), (type))
286
287 #define WITNESS_DESTROY(lock) \
288 witness_destroy(lock)
289
290 #define WITNESS_CHECKORDER(lock, flags, file, line, interlock) \
291 witness_checkorder((lock), (flags), (file), (line), (interlock))
292
293 #define WITNESS_DEFINEORDER(lock1, lock2) \
294 witness_defineorder((struct lock_object *)(lock1), \
295 (struct lock_object *)(lock2))
296
297 #define WITNESS_LOCK(lock, flags, file, line) \
298 witness_lock((lock), (flags), (file), (line))
299
300 #define WITNESS_UPGRADE(lock, flags, file, line) \
301 witness_upgrade((lock), (flags), (file), (line))
302
303 #define WITNESS_DOWNGRADE(lock, flags, file, line) \
304 witness_downgrade((lock), (flags), (file), (line))
305
306 #define WITNESS_UNLOCK(lock, flags, file, line) \
307 witness_unlock((lock), (flags), (file), (line))
308
309 #define WITNESS_CHECK(flags, lock, fmt, ...) \
310 witness_warn((flags), (lock), (fmt), ## __VA_ARGS__)
311
312 #define WITNESS_WARN(flags, lock, fmt, ...) \
313 witness_warn((flags), (lock), (fmt), ## __VA_ARGS__)
314
315 #define WITNESS_SAVE_DECL(n) \
316 const char * __CONCAT(n, __wf); \
317 int __CONCAT(n, __wl)
318
319 #define WITNESS_SAVE(lock, n) \
320 witness_save((lock), &__CONCAT(n, __wf), &__CONCAT(n, __wl))
321
322 #define WITNESS_RESTORE(lock, n) \
323 witness_restore((lock), __CONCAT(n, __wf), __CONCAT(n, __wl))
324
325 #define WITNESS_NORELEASE(lock) \
326 witness_norelease(&(lock)->lock_object)
327
328 #define WITNESS_RELEASEOK(lock) \
329 witness_releaseok(&(lock)->lock_object)
330
331 #define WITNESS_FILE(lock) \
332 witness_file(lock)
333
334 #define WITNESS_LINE(lock) \
335 witness_line(lock)
336
337 #else /* WITNESS */
338 #define WITNESS_INIT(lock, type) (void)0
339 #define WITNESS_DESTROY(lock) (void)0
340 #define WITNESS_DEFINEORDER(lock1, lock2) 0
341 #define WITNESS_CHECKORDER(lock, flags, file, line, interlock) (void)0
342 #define WITNESS_LOCK(lock, flags, file, line) (void)0
343 #define WITNESS_UPGRADE(lock, flags, file, line) (void)0
344 #define WITNESS_DOWNGRADE(lock, flags, file, line) (void)0
345 #define WITNESS_UNLOCK(lock, flags, file, line) (void)0
346 #define WITNESS_CHECK(flags, lock, fmt, ...) 0
347 #define WITNESS_WARN(flags, lock, fmt, ...) (void)0
348 #define WITNESS_SAVE_DECL(n) (void)0
349 #define WITNESS_SAVE(lock, n) (void)0
350 #define WITNESS_RESTORE(lock, n) (void)0
351 #define WITNESS_NORELEASE(lock) (void)0
352 #define WITNESS_RELEASEOK(lock) (void)0
353 #define WITNESS_FILE(lock) ("?")
354 #define WITNESS_LINE(lock) (0)
355 #endif /* WITNESS */
356
357 #endif /* _KERNEL */
358 #endif /* _SYS_LOCK_H_ */
359