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Commit | Line | Data |
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b97bf3fd PL |
1 | /* |
2 | * net/tipc/handler.c: TIPC signal handling | |
c4307285 | 3 | * |
593a5f22 | 4 | * Copyright (c) 2000-2006, Ericsson AB |
b97bf3fd | 5 | * Copyright (c) 2005, Wind River Systems |
b97bf3fd PL |
6 | * All rights reserved. |
7 | * | |
9ea1fd3c | 8 | * Redistribution and use in source and binary forms, with or without |
b97bf3fd PL |
9 | * modification, are permitted provided that the following conditions are met: |
10 | * | |
9ea1fd3c PL |
11 | * 1. Redistributions of source code must retain the above copyright |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * 3. Neither the names of the copyright holders nor the names of its | |
17 | * contributors may be used to endorse or promote products derived from | |
18 | * this software without specific prior written permission. | |
b97bf3fd | 19 | * |
9ea1fd3c PL |
20 | * Alternatively, this software may be distributed under the terms of the |
21 | * GNU General Public License ("GPL") version 2 as published by the Free | |
22 | * Software Foundation. | |
23 | * | |
24 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
25 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | |
28 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
29 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
30 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
31 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
32 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
33 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
b97bf3fd PL |
34 | * POSSIBILITY OF SUCH DAMAGE. |
35 | */ | |
36 | ||
37 | #include "core.h" | |
38 | ||
39 | struct queue_item { | |
40 | struct list_head next_signal; | |
41 | void (*handler) (unsigned long); | |
42 | unsigned long data; | |
43 | }; | |
44 | ||
e18b890b | 45 | static struct kmem_cache *tipc_queue_item_cache; |
b97bf3fd | 46 | static struct list_head signal_queue_head; |
34af946a | 47 | static DEFINE_SPINLOCK(qitem_lock); |
61cdd4d8 | 48 | static int handler_enabled __read_mostly; |
b97bf3fd PL |
49 | |
50 | static void process_signal_queue(unsigned long dummy); | |
51 | ||
52 | static DECLARE_TASKLET_DISABLED(tipc_tasklet, process_signal_queue, 0); | |
53 | ||
54 | ||
4323add6 | 55 | unsigned int tipc_k_signal(Handler routine, unsigned long argument) |
b97bf3fd PL |
56 | { |
57 | struct queue_item *item; | |
58 | ||
00ede977 | 59 | spin_lock_bh(&qitem_lock); |
b97bf3fd | 60 | if (!handler_enabled) { |
00ede977 | 61 | spin_unlock_bh(&qitem_lock); |
b97bf3fd PL |
62 | return -ENOPROTOOPT; |
63 | } | |
64 | ||
b97bf3fd PL |
65 | item = kmem_cache_alloc(tipc_queue_item_cache, GFP_ATOMIC); |
66 | if (!item) { | |
2cf8aa19 | 67 | pr_err("Signal queue out of memory\n"); |
b97bf3fd PL |
68 | spin_unlock_bh(&qitem_lock); |
69 | return -ENOMEM; | |
70 | } | |
71 | item->handler = routine; | |
72 | item->data = argument; | |
73 | list_add_tail(&item->next_signal, &signal_queue_head); | |
74 | spin_unlock_bh(&qitem_lock); | |
75 | tasklet_schedule(&tipc_tasklet); | |
76 | return 0; | |
77 | } | |
78 | ||
79 | static void process_signal_queue(unsigned long dummy) | |
80 | { | |
81 | struct queue_item *__volatile__ item; | |
82 | struct list_head *l, *n; | |
83 | ||
84 | spin_lock_bh(&qitem_lock); | |
85 | list_for_each_safe(l, n, &signal_queue_head) { | |
86 | item = list_entry(l, struct queue_item, next_signal); | |
87 | list_del(&item->next_signal); | |
88 | spin_unlock_bh(&qitem_lock); | |
89 | item->handler(item->data); | |
90 | spin_lock_bh(&qitem_lock); | |
91 | kmem_cache_free(tipc_queue_item_cache, item); | |
92 | } | |
93 | spin_unlock_bh(&qitem_lock); | |
94 | } | |
95 | ||
4323add6 | 96 | int tipc_handler_start(void) |
b97bf3fd | 97 | { |
c4307285 | 98 | tipc_queue_item_cache = |
b97bf3fd | 99 | kmem_cache_create("tipc_queue_items", sizeof(struct queue_item), |
20c2df83 | 100 | 0, SLAB_HWCACHE_ALIGN, NULL); |
b97bf3fd PL |
101 | if (!tipc_queue_item_cache) |
102 | return -ENOMEM; | |
103 | ||
104 | INIT_LIST_HEAD(&signal_queue_head); | |
105 | tasklet_enable(&tipc_tasklet); | |
106 | handler_enabled = 1; | |
107 | return 0; | |
108 | } | |
109 | ||
4323add6 | 110 | void tipc_handler_stop(void) |
b97bf3fd PL |
111 | { |
112 | struct list_head *l, *n; | |
c4307285 | 113 | struct queue_item *item; |
b97bf3fd | 114 | |
00ede977 YX |
115 | spin_lock_bh(&qitem_lock); |
116 | if (!handler_enabled) { | |
117 | spin_unlock_bh(&qitem_lock); | |
b97bf3fd | 118 | return; |
00ede977 | 119 | } |
b97bf3fd | 120 | handler_enabled = 0; |
00ede977 YX |
121 | spin_unlock_bh(&qitem_lock); |
122 | ||
b97bf3fd PL |
123 | tasklet_kill(&tipc_tasklet); |
124 | ||
125 | spin_lock_bh(&qitem_lock); | |
126 | list_for_each_safe(l, n, &signal_queue_head) { | |
127 | item = list_entry(l, struct queue_item, next_signal); | |
128 | list_del(&item->next_signal); | |
129 | kmem_cache_free(tipc_queue_item_cache, item); | |
130 | } | |
131 | spin_unlock_bh(&qitem_lock); | |
132 | ||
133 | kmem_cache_destroy(tipc_queue_item_cache); | |
134 | } |