Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 1 | /* |
| 2 | * net/tipc/handler.c: TIPC signal handling |
YOSHIFUJI Hideaki | c430728 | 2007-02-09 23:25:21 +0900 | [diff] [blame] | 3 | * |
Per Liden | 593a5f2 | 2006-01-11 19:14:19 +0100 | [diff] [blame] | 4 | * Copyright (c) 2000-2006, Ericsson AB |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 5 | * Copyright (c) 2005, Wind River Systems |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 6 | * All rights reserved. |
| 7 | * |
Per Liden | 9ea1fd3 | 2006-01-11 13:30:43 +0100 | [diff] [blame] | 8 | * Redistribution and use in source and binary forms, with or without |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 9 | * modification, are permitted provided that the following conditions are met: |
| 10 | * |
Per Liden | 9ea1fd3 | 2006-01-11 13:30:43 +0100 | [diff] [blame] | 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. |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 19 | * |
Per Liden | 9ea1fd3 | 2006-01-11 13:30:43 +0100 | [diff] [blame] | 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 |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 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 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 45 | static struct kmem_cache *tipc_queue_item_cache; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 46 | static struct list_head signal_queue_head; |
Ingo Molnar | 34af946 | 2006-06-27 02:53:55 -0700 | [diff] [blame] | 47 | static DEFINE_SPINLOCK(qitem_lock); |
Allan Stephens | e3ec9c7 | 2010-12-31 18:59:34 +0000 | [diff] [blame^] | 48 | static int handler_enabled; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 49 | |
| 50 | static void process_signal_queue(unsigned long dummy); |
| 51 | |
| 52 | static DECLARE_TASKLET_DISABLED(tipc_tasklet, process_signal_queue, 0); |
| 53 | |
| 54 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 55 | unsigned int tipc_k_signal(Handler routine, unsigned long argument) |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 56 | { |
| 57 | struct queue_item *item; |
| 58 | |
| 59 | if (!handler_enabled) { |
| 60 | err("Signal request ignored by handler\n"); |
| 61 | return -ENOPROTOOPT; |
| 62 | } |
| 63 | |
| 64 | spin_lock_bh(&qitem_lock); |
| 65 | item = kmem_cache_alloc(tipc_queue_item_cache, GFP_ATOMIC); |
| 66 | if (!item) { |
| 67 | err("Signal queue out of memory\n"); |
| 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 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 96 | int tipc_handler_start(void) |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 97 | { |
YOSHIFUJI Hideaki | c430728 | 2007-02-09 23:25:21 +0900 | [diff] [blame] | 98 | tipc_queue_item_cache = |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 99 | kmem_cache_create("tipc_queue_items", sizeof(struct queue_item), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 100 | 0, SLAB_HWCACHE_ALIGN, NULL); |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 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 | |
Per Liden | 4323add | 2006-01-18 00:38:21 +0100 | [diff] [blame] | 110 | void tipc_handler_stop(void) |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 111 | { |
| 112 | struct list_head *l, *n; |
YOSHIFUJI Hideaki | c430728 | 2007-02-09 23:25:21 +0900 | [diff] [blame] | 113 | struct queue_item *item; |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 114 | |
| 115 | if (!handler_enabled) |
| 116 | return; |
| 117 | |
| 118 | handler_enabled = 0; |
| 119 | tasklet_disable(&tipc_tasklet); |
| 120 | tasklet_kill(&tipc_tasklet); |
| 121 | |
| 122 | spin_lock_bh(&qitem_lock); |
| 123 | list_for_each_safe(l, n, &signal_queue_head) { |
| 124 | item = list_entry(l, struct queue_item, next_signal); |
| 125 | list_del(&item->next_signal); |
| 126 | kmem_cache_free(tipc_queue_item_cache, item); |
| 127 | } |
| 128 | spin_unlock_bh(&qitem_lock); |
| 129 | |
| 130 | kmem_cache_destroy(tipc_queue_item_cache); |
| 131 | } |
| 132 | |