131 lines
4.0 KiB
C
131 lines
4.0 KiB
C
/*
|
|
* 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;
|
|
|
|
if (!handler_enabled) {
|
|
pr_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) {
|
|
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;
|
|
|
|
if (!handler_enabled)
|
|
return;
|
|
|
|
handler_enabled = 0;
|
|
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);
|
|
}
|