diff options
Diffstat (limited to 'net/tipc/handler.c')
| -rw-r--r-- | net/tipc/handler.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/net/tipc/handler.c b/net/tipc/handler.c new file mode 100644 index 00000000000..f320010f8a6 --- /dev/null +++ b/net/tipc/handler.c @@ -0,0 +1,132 @@ +/* + * net/tipc/handler.c: TIPC signal handling + * + * Copyright (c) 2000-2006, Ericsson AB + * Copyright (c) 2005, Wind River Systems + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the names of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2 as published by the Free + * Software Foundation. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include "core.h" + +struct queue_item { + struct list_head next_signal; + void (*handler) (unsigned long); + unsigned long data; +}; + +static kmem_cache_t *tipc_queue_item_cache; +static struct list_head signal_queue_head; +static spinlock_t qitem_lock = SPIN_LOCK_UNLOCKED; +static int handler_enabled = 0; + +static void process_signal_queue(unsigned long dummy); + +static DECLARE_TASKLET_DISABLED(tipc_tasklet, process_signal_queue, 0); + + +unsigned int k_signal(Handler routine, unsigned long argument) +{ + struct queue_item *item; + + if (!handler_enabled) { + err("Signal request ignored by handler\n"); + return -ENOPROTOOPT; + } + + spin_lock_bh(&qitem_lock); + item = kmem_cache_alloc(tipc_queue_item_cache, GFP_ATOMIC); + if (!item) { + err("Signal queue out of memory\n"); + spin_unlock_bh(&qitem_lock); + return -ENOMEM; + } + item->handler = routine; + item->data = argument; + list_add_tail(&item->next_signal, &signal_queue_head); + spin_unlock_bh(&qitem_lock); + tasklet_schedule(&tipc_tasklet); + return 0; +} + +static void process_signal_queue(unsigned long dummy) +{ + struct queue_item *__volatile__ item; + struct list_head *l, *n; + + spin_lock_bh(&qitem_lock); + list_for_each_safe(l, n, &signal_queue_head) { + item = list_entry(l, struct queue_item, next_signal); + list_del(&item->next_signal); + spin_unlock_bh(&qitem_lock); + item->handler(item->data); + spin_lock_bh(&qitem_lock); + kmem_cache_free(tipc_queue_item_cache, item); + } + spin_unlock_bh(&qitem_lock); +} + +int handler_start(void) +{ + tipc_queue_item_cache = + kmem_cache_create("tipc_queue_items", sizeof(struct queue_item), + 0, SLAB_HWCACHE_ALIGN, NULL, NULL); + if (!tipc_queue_item_cache) + return -ENOMEM; + + INIT_LIST_HEAD(&signal_queue_head); + tasklet_enable(&tipc_tasklet); + handler_enabled = 1; + return 0; +} + +void handler_stop(void) +{ + struct list_head *l, *n; + struct queue_item *item; + + if (!handler_enabled) + return; + + handler_enabled = 0; + tasklet_disable(&tipc_tasklet); + tasklet_kill(&tipc_tasklet); + + spin_lock_bh(&qitem_lock); + list_for_each_safe(l, n, &signal_queue_head) { + item = list_entry(l, struct queue_item, next_signal); + list_del(&item->next_signal); + kmem_cache_free(tipc_queue_item_cache, item); + } + spin_unlock_bh(&qitem_lock); + + kmem_cache_destroy(tipc_queue_item_cache); +} + |