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22#include <linux/spinlock.h>
23#include <linux/list.h>
24#include <linux/sched.h>
25#include <linux/delay.h>
26
27#include "w1_family.h"
28#include "w1.h"
29
30DEFINE_SPINLOCK(w1_flock);
31static LIST_HEAD(w1_families);
32
33int w1_register_family(struct w1_family *newf)
34{
35 struct list_head *ent, *n;
36 struct w1_family *f;
37 int ret = 0;
38
39 spin_lock(&w1_flock);
40 list_for_each_safe(ent, n, &w1_families) {
41 f = list_entry(ent, struct w1_family, family_entry);
42
43 if (f->fid == newf->fid) {
44 ret = -EEXIST;
45 break;
46 }
47 }
48
49 if (!ret) {
50 atomic_set(&newf->refcnt, 0);
51 list_add_tail(&newf->family_entry, &w1_families);
52 }
53 spin_unlock(&w1_flock);
54
55
56 w1_reconnect_slaves(newf, 1);
57
58 return ret;
59}
60
61void w1_unregister_family(struct w1_family *fent)
62{
63 struct list_head *ent, *n;
64 struct w1_family *f;
65
66 spin_lock(&w1_flock);
67 list_for_each_safe(ent, n, &w1_families) {
68 f = list_entry(ent, struct w1_family, family_entry);
69
70 if (f->fid == fent->fid) {
71 list_del(&fent->family_entry);
72 break;
73 }
74 }
75 spin_unlock(&w1_flock);
76
77
78 w1_reconnect_slaves(fent, 0);
79
80 while (atomic_read(&fent->refcnt)) {
81 printk(KERN_INFO "Waiting for family %u to become free: refcnt=%d.\n",
82 fent->fid, atomic_read(&fent->refcnt));
83
84 if (msleep_interruptible(1000))
85 flush_signals(current);
86 }
87}
88
89
90
91
92struct w1_family * w1_family_registered(u8 fid)
93{
94 struct list_head *ent, *n;
95 struct w1_family *f = NULL;
96 int ret = 0;
97
98 list_for_each_safe(ent, n, &w1_families) {
99 f = list_entry(ent, struct w1_family, family_entry);
100
101 if (f->fid == fid) {
102 ret = 1;
103 break;
104 }
105 }
106
107 return (ret) ? f : NULL;
108}
109
110static void __w1_family_put(struct w1_family *f)
111{
112 atomic_dec(&f->refcnt);
113}
114
115void w1_family_put(struct w1_family *f)
116{
117 spin_lock(&w1_flock);
118 __w1_family_put(f);
119 spin_unlock(&w1_flock);
120}
121
122#if 0
123void w1_family_get(struct w1_family *f)
124{
125 spin_lock(&w1_flock);
126 __w1_family_get(f);
127 spin_unlock(&w1_flock);
128}
129#endif
130
131void __w1_family_get(struct w1_family *f)
132{
133 smp_mb__before_atomic_inc();
134 atomic_inc(&f->refcnt);
135 smp_mb__after_atomic_inc();
136}
137
138EXPORT_SYMBOL(w1_unregister_family);
139EXPORT_SYMBOL(w1_register_family);
140