Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
a8018766 | 2 | * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> |
7785925d | 3 | * |
1da177e4 LT |
4 | * This program is free software; you can redistribute it and/or modify |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
1da177e4 LT |
13 | */ |
14 | ||
15 | #include <linux/spinlock.h> | |
16 | #include <linux/list.h> | |
3f07c014 | 17 | #include <linux/sched/signal.h> |
1da177e4 | 18 | #include <linux/delay.h> |
9623932c | 19 | #include <linux/export.h> |
1da177e4 | 20 | |
de0d6dbd | 21 | #include "w1_internal.h" |
1da177e4 LT |
22 | |
23 | DEFINE_SPINLOCK(w1_flock); | |
24 | static LIST_HEAD(w1_families); | |
25 | ||
b3be177a DF |
26 | /** |
27 | * w1_register_family() - register a device family driver | |
28 | * @newf: family to register | |
29 | */ | |
1da177e4 LT |
30 | int w1_register_family(struct w1_family *newf) |
31 | { | |
32 | struct list_head *ent, *n; | |
33 | struct w1_family *f; | |
34 | int ret = 0; | |
35 | ||
1da177e4 LT |
36 | spin_lock(&w1_flock); |
37 | list_for_each_safe(ent, n, &w1_families) { | |
38 | f = list_entry(ent, struct w1_family, family_entry); | |
39 | ||
40 | if (f->fid == newf->fid) { | |
41 | ret = -EEXIST; | |
42 | break; | |
43 | } | |
44 | } | |
45 | ||
46 | if (!ret) { | |
47 | atomic_set(&newf->refcnt, 0); | |
1da177e4 LT |
48 | list_add_tail(&newf->family_entry, &w1_families); |
49 | } | |
1da177e4 LT |
50 | spin_unlock(&w1_flock); |
51 | ||
c30c9b15 DF |
52 | /* check default devices against the new set of drivers */ |
53 | w1_reconnect_slaves(newf, 1); | |
6adf87bd | 54 | |
1da177e4 LT |
55 | return ret; |
56 | } | |
50fa2951 | 57 | EXPORT_SYMBOL(w1_register_family); |
1da177e4 | 58 | |
b3be177a DF |
59 | /** |
60 | * w1_unregister_family() - unregister a device family driver | |
61 | * @fent: family to unregister | |
62 | */ | |
1da177e4 LT |
63 | void w1_unregister_family(struct w1_family *fent) |
64 | { | |
65 | struct list_head *ent, *n; | |
66 | struct w1_family *f; | |
67 | ||
68 | spin_lock(&w1_flock); | |
69 | list_for_each_safe(ent, n, &w1_families) { | |
70 | f = list_entry(ent, struct w1_family, family_entry); | |
71 | ||
72 | if (f->fid == fent->fid) { | |
73 | list_del(&fent->family_entry); | |
74 | break; | |
75 | } | |
76 | } | |
1da177e4 LT |
77 | spin_unlock(&w1_flock); |
78 | ||
c30c9b15 DF |
79 | /* deatch devices using this family code */ |
80 | w1_reconnect_slaves(fent, 0); | |
81 | ||
1da177e4 | 82 | while (atomic_read(&fent->refcnt)) { |
fdc9167a | 83 | pr_info("Waiting for family %u to become free: refcnt=%d.\n", |
1da177e4 LT |
84 | fent->fid, atomic_read(&fent->refcnt)); |
85 | ||
86 | if (msleep_interruptible(1000)) | |
87 | flush_signals(current); | |
88 | } | |
89 | } | |
50fa2951 | 90 | EXPORT_SYMBOL(w1_unregister_family); |
1da177e4 LT |
91 | |
92 | /* | |
93 | * Should be called under w1_flock held. | |
94 | */ | |
95 | struct w1_family * w1_family_registered(u8 fid) | |
96 | { | |
97 | struct list_head *ent, *n; | |
98 | struct w1_family *f = NULL; | |
99 | int ret = 0; | |
100 | ||
101 | list_for_each_safe(ent, n, &w1_families) { | |
102 | f = list_entry(ent, struct w1_family, family_entry); | |
103 | ||
104 | if (f->fid == fid) { | |
105 | ret = 1; | |
106 | break; | |
107 | } | |
108 | } | |
109 | ||
110 | return (ret) ? f : NULL; | |
111 | } | |
112 | ||
70d484bf EP |
113 | static void __w1_family_put(struct w1_family *f) |
114 | { | |
fe3cb823 | 115 | atomic_dec(&f->refcnt); |
70d484bf EP |
116 | } |
117 | ||
1da177e4 LT |
118 | void w1_family_put(struct w1_family *f) |
119 | { | |
120 | spin_lock(&w1_flock); | |
121 | __w1_family_put(f); | |
122 | spin_unlock(&w1_flock); | |
123 | } | |
124 | ||
70d484bf | 125 | #if 0 |
1da177e4 LT |
126 | void w1_family_get(struct w1_family *f) |
127 | { | |
128 | spin_lock(&w1_flock); | |
129 | __w1_family_get(f); | |
130 | spin_unlock(&w1_flock); | |
1da177e4 | 131 | } |
70d484bf | 132 | #endif /* 0 */ |
1da177e4 LT |
133 | |
134 | void __w1_family_get(struct w1_family *f) | |
135 | { | |
4e857c58 | 136 | smp_mb__before_atomic(); |
1da177e4 | 137 | atomic_inc(&f->refcnt); |
4e857c58 | 138 | smp_mb__after_atomic(); |
1da177e4 | 139 | } |