[PATCH] ISDN kernelcapi notifier workqueue re-structured

From: Armin Schindler <armin@melware.de>

Use the notifier workqueue in a cleaner way.

diff --git a/drivers/isdn/capi/kcapi.c b/drivers/isdn/capi/kcapi.c
index 01a54bc9ae9047bdbc425a2470716afa7b20f36c..1b4d069b6135057086684639da8be02ef74903f9 100644 (file)
--- a/drivers/isdn/capi/kcapi.c
+++ b/drivers/isdn/capi/kcapi.c
@@ -1,4 +1,4 @@
-/* $Id: kcapi.c,v 1.1.2.5 2004/03/15 12:32:31 armin Exp $
+/* $Id: kcapi.c,v 1.1.2.6 2004/03/16 08:00:08 armin Exp $
  * 
  * Kernel CAPI 2.0 Module
  * 
@@ -31,7 +31,7 @@
 #include <linux/b1lli.h>
 #endif
 
-static char *revision = "$Revision: 1.1.2.5 $";
+static char *revision = "$Revision: 1.1.2.6 $";
 
 /* ------------------------------------------------------------- */
 
@@ -45,7 +45,7 @@ MODULE_PARM(showcapimsgs, "i");
 /* ------------------------------------------------------------- */
 
 struct capi_notifier {
-       struct capi_notifier *next;
+       struct work_struct work;
        unsigned int cmd;
        u32 controller;
        u16 applid;
@@ -69,7 +69,6 @@ struct capi_ctr *capi_cards[CAPI_MAXCONTR];
 static int ncards;
 static struct sk_buff_head recv_queue;
 
-static struct work_struct tq_state_notify;
 static struct work_struct tq_recv_notify;
 
 /* -------- controller ref counting -------------------------------------- */
@@ -161,79 +160,6 @@ static void release_appl(struct capi_ctr *card, u16 applid)
        capi_ctr_put(card);
 }
 
-
-/* -------- Notifier handling --------------------------------- */
-
-static struct capi_notifier_list{
-       struct capi_notifier *head;
-       struct capi_notifier *tail;
-} notifier_list;
-
-static spinlock_t notifier_lock = SPIN_LOCK_UNLOCKED;
-
-static inline void notify_enqueue(struct capi_notifier *np)
-{
-       struct capi_notifier_list *q = &notifier_list;
-       unsigned long flags;
-
-       spin_lock_irqsave(&notifier_lock, flags);
-       if (q->tail) {
-               q->tail->next = np;
-               q->tail = np;
-       } else {
-               q->head = q->tail = np;
-       }
-       spin_unlock_irqrestore(&notifier_lock, flags);
-}
-
-static inline struct capi_notifier *notify_dequeue(void)
-{
-       struct capi_notifier_list *q = &notifier_list;
-       struct capi_notifier *np = 0;
-       unsigned long flags;
-
-       spin_lock_irqsave(&notifier_lock, flags);
-       if (q->head) {
-               np = q->head;
-               if ((q->head = np->next) == 0)
-                       q->tail = 0;
-               np->next = 0;
-       }
-       spin_unlock_irqrestore(&notifier_lock, flags);
-       return np;
-}
-
-static int notify_push(unsigned int cmd, u32 controller,
-                               u16 applid, u32 ncci)
-{
-       struct capi_notifier *np;
-
-       if (!try_module_get(THIS_MODULE)) {
-               printk(KERN_WARNING "%s: cannot reserve module\n", __FUNCTION__);
-               return -1;
-       }
-       np = (struct capi_notifier *)kmalloc(sizeof(struct capi_notifier), GFP_ATOMIC);
-       if (!np) {
-               module_put(THIS_MODULE);
-               return -1;
-       }
-       memset(np, 0, sizeof(struct capi_notifier));
-       np->cmd = cmd;
-       np->controller = controller;
-       np->applid = applid;
-       np->ncci = ncci;
-       notify_enqueue(np);
-       /*
-        * The notifier will result in adding/deleteing
-        * of devices. Devices can only removed in
-        * user process, not in bh.
-        */
-       __module_get(THIS_MODULE);
-       if (schedule_work(&tq_state_notify) == 0)
-               module_put(THIS_MODULE);
-       return 0;
-}
-
 /* -------- KCI_CONTRUP --------------------------------------- */
 
 static void notify_up(u32 contr)
@@ -271,31 +197,43 @@ static void notify_down(u32 contr)
        }
 }
 
-/* ------------------------------------------------------------ */
-
-static inline void notify_doit(struct capi_notifier *np)
+static void notify_handler(void *data)
 {
+       struct capi_notifier *np = data;
+
        switch (np->cmd) {
-               case KCI_CONTRUP:
-                       notify_up(np->controller);
-                       break;
-               case KCI_CONTRDOWN:
-                       notify_down(np->controller);
-                       break;
+       case KCI_CONTRUP:
+               notify_up(np->controller);
+               break;
+       case KCI_CONTRDOWN:
+               notify_down(np->controller);
+               break;
        }
+
+       kfree(np);
 }
 
-static void notify_handler(void *dummy)
+/*
+ * The notifier will result in adding/deleteing of devices. Devices can
+ * only removed in user process, not in bh.
+ */
+static int notify_push(unsigned int cmd, u32 controller, u16 applid, u32 ncci)
 {
-       struct capi_notifier *np;
+       struct capi_notifier *np = kmalloc(sizeof(*np), GFP_ATOMIC);
 
-       while ((np = notify_dequeue()) != 0) {
-               notify_doit(np);
-               kfree(np);
-               module_put(THIS_MODULE);
-       }
-       module_put(THIS_MODULE);
+       if (!np)
+               return -ENOMEM;
+
+       INIT_WORK(&np->work, notify_handler, np);
+       np->cmd = cmd;
+       np->controller = controller;
+       np->applid = applid;
+       np->ncci = ncci;
+
+       schedule_work(&np->work);
+       return 0;
 }
+
        
 /* -------- Receiver ------------------------------------------ */
 
@@ -989,7 +927,6 @@ static int __init kcapi_init(void)
 
        skb_queue_head_init(&recv_queue);
 
-       INIT_WORK(&tq_state_notify, notify_handler, NULL);
        INIT_WORK(&tq_recv_notify, recv_handler, NULL);
 
         kcapi_proc_init();
@@ -1009,6 +946,9 @@ static int __init kcapi_init(void)
 static void __exit kcapi_exit(void)
 {
         kcapi_proc_exit();
+
+       /* make sure all notifiers are finished */
+       flush_scheduled_work();
 }
 
 module_init(kcapi_init);