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 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 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 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 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 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