+++ /dev/null
-/*
- * 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 struct kmem_cache *tipc_queue_item_cache;
-static struct list_head signal_queue_head;
-static DEFINE_SPINLOCK(qitem_lock);
-static int handler_enabled __read_mostly;
-
-static void process_signal_queue(unsigned long dummy);
-
-static DECLARE_TASKLET_DISABLED(tipc_tasklet, process_signal_queue, 0);
-
-
-unsigned int tipc_k_signal(Handler routine, unsigned long argument)
-{
- struct queue_item *item;
-
- spin_lock_bh(&qitem_lock);
- if (!handler_enabled) {
- spin_unlock_bh(&qitem_lock);
- return -ENOPROTOOPT;
- }
-
- item = kmem_cache_alloc(tipc_queue_item_cache, GFP_ATOMIC);
- if (!item) {
- pr_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 tipc_handler_start(void)
-{
- tipc_queue_item_cache =
- kmem_cache_create("tipc_queue_items", sizeof(struct queue_item),
- 0, SLAB_HWCACHE_ALIGN, NULL);
- if (!tipc_queue_item_cache)
- return -ENOMEM;
-
- INIT_LIST_HEAD(&signal_queue_head);
- tasklet_enable(&tipc_tasklet);
- handler_enabled = 1;
- return 0;
-}
-
-void tipc_handler_stop(void)
-{
- struct list_head *l, *n;
- struct queue_item *item;
-
- spin_lock_bh(&qitem_lock);
- if (!handler_enabled) {
- spin_unlock_bh(&qitem_lock);
- return;
- }
- handler_enabled = 0;
- spin_unlock_bh(&qitem_lock);
-
- 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);
-}