1 files changed, 129 insertions, 0 deletions

diff --git a/net/tipc/handler.c b/net/tipc/handler.c
new file mode 100644
index 000000000000..c8fbb2071dfc
--- /dev/null
+++ b/net/tipc/handler.c
@@ -0,0 +1,129 @@
+/*
+ * net/tipc/handler.c: TIPC signal handling
+ * 
+ * Copyright (c) 2003-2005, Ericsson Research Canada
+ * Copyright (c) 2005, Wind River Systems
+ * Copyright (c) 2005-2006, Ericsson AB
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without 
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this 
+ * list of conditions and the following disclaimer.
+ * 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.
+ * 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.
+ *
+ * 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);
+}
+