xref: /freebsd/sys/sys/lockmgr.h (revision 9768746b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2008 Attilio Rao <attilio@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice(s), this list of conditions and the following disclaimer as
12  *    the first lines of this file unmodified other than the possible
13  *    addition of one or more copyright notices.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice(s), this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21  * DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
25  * 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 SUCH
28  * DAMAGE.
29  *
30  * $FreeBSD$
31  */
32 
33 #ifndef	_SYS_LOCKMGR_H_
34 #define	_SYS_LOCKMGR_H_
35 
36 #include <sys/_lock.h>
37 #include <sys/_lockmgr.h>
38 #include <sys/_mutex.h>
39 #include <sys/_rwlock.h>
40 
41 #define	LK_SHARE			0x01
42 #define	LK_SHARED_WAITERS		0x02
43 #define	LK_EXCLUSIVE_WAITERS		0x04
44 #define	LK_EXCLUSIVE_SPINNERS		0x08
45 #define	LK_WRITER_RECURSED		0x10
46 #define	LK_ALL_WAITERS							\
47 	(LK_SHARED_WAITERS | LK_EXCLUSIVE_WAITERS)
48 #define	LK_FLAGMASK							\
49 	(LK_SHARE | LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS | LK_WRITER_RECURSED)
50 
51 #define	LK_HOLDER(x)			((x) & ~LK_FLAGMASK)
52 #define	LK_SHARERS_SHIFT		5
53 #define	LK_SHARERS(x)			(LK_HOLDER(x) >> LK_SHARERS_SHIFT)
54 #define	LK_SHARERS_LOCK(x)		((x) << LK_SHARERS_SHIFT | LK_SHARE)
55 #define	LK_ONE_SHARER			(1 << LK_SHARERS_SHIFT)
56 #define	LK_UNLOCKED			LK_SHARERS_LOCK(0)
57 #define	LK_KERNPROC			((uintptr_t)(-1) & ~LK_FLAGMASK)
58 
59 #ifdef _KERNEL
60 
61 #if !defined(LOCK_FILE) || !defined(LOCK_LINE)
62 #error	"LOCK_FILE and LOCK_LINE not defined, include <sys/lock.h> before"
63 #endif
64 
65 struct thread;
66 #define	lk_recurse	lock_object.lo_data
67 
68 /*
69  * Function prototipes.  Routines that start with an underscore are not part
70  * of the public interface and might be wrappered with a macro.
71  */
72 int	 __lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk,
73 	    const char *wmesg, int prio, int timo, const char *file, int line);
74 int	 lockmgr_lock_flags(struct lock *lk, u_int flags,
75 	    struct lock_object *ilk, const char *file, int line);
76 int	lockmgr_slock(struct lock *lk, u_int flags, const char *file, int line);
77 int	lockmgr_xlock(struct lock *lk, u_int flags, const char *file, int line);
78 int	lockmgr_unlock(struct lock *lk);
79 
80 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
81 void	 _lockmgr_assert(const struct lock *lk, int what, const char *file, int line);
82 #endif
83 void	 _lockmgr_disown(struct lock *lk, const char *file, int line);
84 
85 void	 lockallowrecurse(struct lock *lk);
86 void	 lockallowshare(struct lock *lk);
87 void	 lockdestroy(struct lock *lk);
88 void	 lockdisablerecurse(struct lock *lk);
89 void	 lockdisableshare(struct lock *lk);
90 void	 lockinit(struct lock *lk, int prio, const char *wmesg, int timo,
91 	    int flags);
92 #ifdef DDB
93 int	 lockmgr_chain(struct thread *td, struct thread **ownerp);
94 #endif
95 void	 lockmgr_printinfo(const struct lock *lk);
96 int	 lockstatus(const struct lock *lk);
97 
98 /*
99  * As far as the ilk can be a static NULL pointer these functions need a
100  * strict prototype in order to safely use the lock_object member.
101  */
102 static __inline int
103 _lockmgr_args(struct lock *lk, u_int flags, struct mtx *ilk, const char *wmesg,
104     int prio, int timo, const char *file, int line)
105 {
106 
107 	return (__lockmgr_args(lk, flags, (ilk != NULL) ? &ilk->lock_object :
108 	    NULL, wmesg, prio, timo, file, line));
109 }
110 
111 static __inline int
112 _lockmgr_args_rw(struct lock *lk, u_int flags, struct rwlock *ilk,
113     const char *wmesg, int prio, int timo, const char *file, int line)
114 {
115 
116 	return (__lockmgr_args(lk, flags, (ilk != NULL) ? &ilk->lock_object :
117 	    NULL, wmesg, prio, timo, file, line));
118 }
119 
120 /*
121  * Define aliases in order to complete lockmgr KPI.
122  */
123 #define	lockmgr_read_value(lk)	((lk)->lk_lock)
124 #define	lockmgr(lk, flags, ilk)						\
125 	_lockmgr_args((lk), (flags), (ilk), LK_WMESG_DEFAULT,		\
126 	    LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, LOCK_FILE, LOCK_LINE)
127 #define	lockmgr_args(lk, flags, ilk, wmesg, prio, timo)			\
128 	_lockmgr_args((lk), (flags), (ilk), (wmesg), (prio), (timo),	\
129 	    LOCK_FILE, LOCK_LINE)
130 #define	lockmgr_args_rw(lk, flags, ilk, wmesg, prio, timo)		\
131 	_lockmgr_args_rw((lk), (flags), (ilk), (wmesg), (prio), (timo),	\
132 	    LOCK_FILE, LOCK_LINE)
133 #define	lockmgr_disown(lk)						\
134 	_lockmgr_disown((lk), LOCK_FILE, LOCK_LINE)
135 #define	lockmgr_recursed_v(v)						\
136 	(v & LK_WRITER_RECURSED)
137 #define	lockmgr_recursed(lk)						\
138 	lockmgr_recursed_v((lk)->lk_lock)
139 #define	lockmgr_rw(lk, flags, ilk)					\
140 	_lockmgr_args_rw((lk), (flags), (ilk), LK_WMESG_DEFAULT,	\
141 	    LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, LOCK_FILE, LOCK_LINE)
142 #ifdef INVARIANTS
143 #define	lockmgr_assert(lk, what)					\
144 	_lockmgr_assert((lk), (what), LOCK_FILE, LOCK_LINE)
145 #else
146 #define	lockmgr_assert(lk, what)
147 #endif
148 
149 /*
150  * Flags for lockinit().
151  */
152 #define	LK_INIT_MASK	0x0001FF
153 #define	LK_CANRECURSE	0x000001
154 #define	LK_NODUP	0x000002
155 #define	LK_NOPROFILE	0x000004
156 #define	LK_NOSHARE	0x000008
157 #define	LK_NOWITNESS	0x000010
158 #define	LK_QUIET	0x000020
159 #define	LK_UNUSED0	0x000040	/* Was LK_ADAPTIVE */
160 #define	LK_IS_VNODE	0x000080	/* Tell WITNESS about a VNODE lock */
161 #define	LK_NEW		0x000100
162 
163 /*
164  * Additional attributes to be used in lockmgr().
165  */
166 #define	LK_EATTR_MASK	0x00FF00
167 #define	LK_INTERLOCK	0x000100
168 #define	LK_NOWAIT	0x000200
169 #define	LK_RETRY	0x000400
170 #define	LK_SLEEPFAIL	0x000800
171 #define	LK_TIMELOCK	0x001000
172 #define	LK_NODDLKTREAT	0x002000
173 #define	LK_ADAPTIVE	0x004000
174 
175 /*
176  * Operations for lockmgr().
177  */
178 #define	LK_TYPE_MASK	0xFF0000
179 #define	LK_DOWNGRADE	0x010000
180 #define	LK_DRAIN	0x020000
181 #define	LK_EXCLOTHER	0x040000
182 #define	LK_EXCLUSIVE	0x080000
183 #define	LK_RELEASE	0x100000
184 #define	LK_SHARED	0x200000
185 #define	LK_UPGRADE	0x400000
186 #define	LK_TRYUPGRADE	0x800000
187 
188 #define	LK_TOTAL_MASK	(LK_INIT_MASK | LK_EATTR_MASK | LK_TYPE_MASK)
189 
190 /*
191  * Default values for lockmgr_args().
192  */
193 #define	LK_WMESG_DEFAULT	(NULL)
194 #define	LK_PRIO_DEFAULT		(0)
195 #define	LK_TIMO_DEFAULT		(0)
196 
197 /*
198  * Assertion flags.
199  */
200 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
201 #define	KA_LOCKED	LA_LOCKED
202 #define	KA_SLOCKED	LA_SLOCKED
203 #define	KA_XLOCKED	LA_XLOCKED
204 #define	KA_UNLOCKED	LA_UNLOCKED
205 #define	KA_RECURSED	LA_RECURSED
206 #define	KA_NOTRECURSED	LA_NOTRECURSED
207 #endif
208 
209 #endif /* _KERNEL */
210 
211 #endif /* !_SYS_LOCKMGR_H_ */
212