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