1 /* $NetBSD: linux_notifier.c,v 1.2 2021/12/19 11:47:08 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2021 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 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: linux_notifier.c,v 1.2 2021/12/19 11:47:08 riastradh Exp $");
34
35 #include <sys/types.h>
36
37 #include <sys/pserialize.h>
38 #include <sys/xcall.h>
39
40 #include <linux/notifier.h>
41 #include <linux/spinlock.h>
42
43 void
ATOMIC_INIT_NOTIFIER_HEAD(struct atomic_notifier_head * H)44 ATOMIC_INIT_NOTIFIER_HEAD(struct atomic_notifier_head *H)
45 {
46
47 spin_lock_init(&H->anh_lock);
48 PSLIST_INIT(&H->anh_list);
49 }
50
51 void
ATOMIC_CLEANUP_NOTIFIER_HEAD(struct atomic_notifier_head * H)52 ATOMIC_CLEANUP_NOTIFIER_HEAD(struct atomic_notifier_head *H)
53 {
54
55 PSLIST_DESTROY(&H->anh_list);
56 spin_lock_destroy(&H->anh_lock);
57 }
58
59 void
atomic_notifier_chain_register(struct atomic_notifier_head * H,struct notifier_block * B)60 atomic_notifier_chain_register(struct atomic_notifier_head *H,
61 struct notifier_block *B)
62 {
63
64 spin_lock(&H->anh_lock);
65 PSLIST_WRITER_INSERT_HEAD(&H->anh_list, B, nb_entry);
66 spin_unlock(&H->anh_lock);
67 }
68
69 void
atomic_notifier_chain_unregister(struct atomic_notifier_head * H,struct notifier_block * B)70 atomic_notifier_chain_unregister(struct atomic_notifier_head *H,
71 struct notifier_block *B)
72 {
73
74 spin_lock(&H->anh_lock);
75 PSLIST_WRITER_REMOVE(B, nb_entry);
76 spin_unlock(&H->anh_lock);
77
78 xc_barrier(0);
79 }
80
81 void
atomic_notifier_call_chain(struct atomic_notifier_head * H,unsigned long arg0,void * arg1)82 atomic_notifier_call_chain(struct atomic_notifier_head *H,
83 unsigned long arg0, void *arg1)
84 {
85 struct notifier_block *B;
86 int s;
87
88 s = pserialize_read_enter();
89 PSLIST_READER_FOREACH(B, &H->anh_list, struct notifier_block, nb_entry)
90 {
91 if ((*B->notifier_call)(B, arg0, arg1) == NOTIFY_DONE)
92 break;
93 }
94 pserialize_read_exit(s);
95 }
96