1 | /* $NetBSD: ww_mutex.h,v 1.11 2015/05/21 21:55:55 riastradh Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2014 The NetBSD Foundation, Inc. |
5 | * All rights reserved. |
6 | * |
7 | * This code is derived from software contributed to The NetBSD Foundation |
8 | * by Taylor R. Campbell. |
9 | * |
10 | * Redistribution and use in source and binary forms, with or without |
11 | * modification, are permitted provided that the following conditions |
12 | * are met: |
13 | * 1. Redistributions of source code must retain the above copyright |
14 | * notice, this list of conditions and the following disclaimer. |
15 | * 2. Redistributions in binary form must reproduce the above copyright |
16 | * notice, this list of conditions and the following disclaimer in the |
17 | * documentation and/or other materials provided with the distribution. |
18 | * |
19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
29 | * POSSIBILITY OF SUCH DAMAGE. |
30 | */ |
31 | |
32 | #ifndef _ASM_WW_MUTEX_H_ |
33 | #define _ASM_WW_MUTEX_H_ |
34 | |
35 | #include <sys/types.h> |
36 | #include <sys/condvar.h> |
37 | #include <sys/mutex.h> |
38 | #include <sys/rbtree.h> |
39 | |
40 | struct ww_class { |
41 | volatile uint64_t wwc_ticket; |
42 | }; |
43 | |
44 | #define DEFINE_WW_CLASS(CLASS) \ |
45 | struct ww_class CLASS = { \ |
46 | .wwc_ticket = 0, \ |
47 | } |
48 | |
49 | struct ww_acquire_ctx { |
50 | struct ww_class *wwx_class __diagused; |
51 | struct lwp *wwx_owner __diagused; |
52 | uint64_t wwx_ticket; |
53 | unsigned wwx_acquired; |
54 | bool wwx_acquire_done; |
55 | struct rb_node wwx_rb_node; |
56 | }; |
57 | |
58 | struct ww_mutex { |
59 | enum ww_mutex_state { |
60 | WW_UNLOCKED, /* nobody owns it */ |
61 | WW_OWNED, /* owned by a lwp without a context */ |
62 | WW_CTX, /* owned by a context */ |
63 | WW_WANTOWN, /* owned by ctx, waiters w/o ctx waiting */ |
64 | } wwm_state; |
65 | union { |
66 | struct lwp *owner; |
67 | struct ww_acquire_ctx *ctx; |
68 | } wwm_u; |
69 | /* |
70 | * XXX wwm_lock must *not* be first, so that the ww_mutex has a |
71 | * different address from the kmutex for LOCKDEBUG purposes. |
72 | */ |
73 | kmutex_t wwm_lock; |
74 | struct ww_class *wwm_class; |
75 | struct rb_tree wwm_waiters; |
76 | kcondvar_t wwm_cv; |
77 | #ifdef LOCKDEBUG |
78 | bool wwm_debug; |
79 | #endif |
80 | }; |
81 | |
82 | /* XXX Make the nm output a little more greppable... */ |
83 | #define ww_acquire_done linux_ww_acquire_done |
84 | #define ww_acquire_fini linux_ww_acquire_fini |
85 | #define ww_acquire_init linux_ww_acquire_init |
86 | #define ww_mutex_destroy linux_ww_mutex_destroy |
87 | #define ww_mutex_init linux_ww_mutex_init |
88 | #define ww_mutex_is_locked linux_ww_mutex_is_locked |
89 | #define ww_mutex_lock linux_ww_mutex_lock |
90 | #define ww_mutex_lock_interruptible linux_ww_mutex_lock_interruptible |
91 | #define ww_mutex_lock_slow linux_ww_mutex_lock_slow |
92 | #define ww_mutex_lock_slow_interruptible linux_ww_mutex_lock_slow_interruptible |
93 | #define ww_mutex_trylock linux_ww_mutex_trylock |
94 | #define ww_mutex_unlock linux_ww_mutex_unlock |
95 | |
96 | void ww_acquire_init(struct ww_acquire_ctx *, struct ww_class *); |
97 | void ww_acquire_done(struct ww_acquire_ctx *); |
98 | void ww_acquire_fini(struct ww_acquire_ctx *); |
99 | |
100 | void ww_mutex_init(struct ww_mutex *, struct ww_class *); |
101 | void ww_mutex_destroy(struct ww_mutex *); |
102 | |
103 | /* |
104 | * WARNING: ww_mutex_is_locked returns true if it is locked by ANYONE. |
105 | * Does NOT mean `Do I hold this lock?' (answering which really |
106 | * requires an acquire context). |
107 | */ |
108 | bool ww_mutex_is_locked(struct ww_mutex *); |
109 | |
110 | int ww_mutex_lock(struct ww_mutex *, struct ww_acquire_ctx *); |
111 | int ww_mutex_lock_interruptible(struct ww_mutex *, |
112 | struct ww_acquire_ctx *); |
113 | void ww_mutex_lock_slow(struct ww_mutex *, struct ww_acquire_ctx *); |
114 | int ww_mutex_lock_slow_interruptible(struct ww_mutex *, |
115 | struct ww_acquire_ctx *); |
116 | int ww_mutex_trylock(struct ww_mutex *); |
117 | void ww_mutex_unlock(struct ww_mutex *); |
118 | |
119 | #endif /* _ASM_WW_MUTEX_H_ */ |
120 | |