CAPI: Switch capiminor list to array

Using a plain array of pointers simplifies the management of capiminors.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index 6704b2b004aa6e9e027a083220763850feb430cf..46f85ae85f5fe44f60778486f92c0407663faf9e 100644 (file)
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -85,7 +85,6 @@ struct datahandle_queue {
 };
 
 struct capiminor {
-       struct list_head list;
        struct capincci  *nccip;
        unsigned int      minor;
        struct dentry *capifs_dentry;
@@ -151,8 +150,8 @@ static LIST_HEAD(capidev_list);
 
 #ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
 
-static DEFINE_RWLOCK(capiminor_list_lock);
-static LIST_HEAD(capiminor_list);
+static DEFINE_RWLOCK(capiminors_lock);
+static struct capiminor **capiminors;
 
 /* -------- datahandles --------------------------------------------- */
 
@@ -213,8 +212,8 @@ static void capiminor_del_all_ack(struct capiminor *mp)
 
 static struct capiminor *capiminor_alloc(struct capi20_appl *ap, u32 ncci)
 {
-       struct capiminor *mp, *p;
-       unsigned int minor = 0;
+       struct capiminor *mp;
+       unsigned int minor;
        unsigned long flags;
 
        mp = kzalloc(sizeof(*mp), GFP_KERNEL);
@@ -233,31 +232,23 @@ static struct capiminor *capiminor_alloc(struct capi20_appl *ap, u32 ncci)
        skb_queue_head_init(&mp->inqueue);
        skb_queue_head_init(&mp->outqueue);
 
-       /* Allocate the least unused minor number.
-        */
-       write_lock_irqsave(&capiminor_list_lock, flags);
-       if (list_empty(&capiminor_list))
-               list_add(&mp->list, &capiminor_list);
-       else {
-               list_for_each_entry(p, &capiminor_list, list) {
-                       if (p->minor > minor)
-                               break;
-                       minor++;
-               }
-               
-               if (minor < capi_ttyminors) {
-                       mp->minor = minor;
-                       list_add(&mp->list, p->list.prev);
+       /* Allocate the least unused minor number. */
+       write_lock_irqsave(&capiminors_lock, flags);
+       for (minor = 0; minor < capi_ttyminors; minor++)
+               if (!capiminors[minor]) {
+                       capiminors[minor] = mp;
+                       break;
                }
-       }
-               write_unlock_irqrestore(&capiminor_list_lock, flags);
+       write_unlock_irqrestore(&capiminors_lock, flags);
 
-       if (!(minor < capi_ttyminors)) {
+       if (minor == capi_ttyminors) {
                printk(KERN_NOTICE "capi: out of minors\n");
-                       kfree(mp);
+               kfree(mp);
                return NULL;
        }
 
+       mp->minor = minor;
+
        return mp;
 }
 
@@ -265,9 +256,9 @@ static void capiminor_free(struct capiminor *mp)
 {
        unsigned long flags;
 
-       write_lock_irqsave(&capiminor_list_lock, flags);
-       list_del(&mp->list);
-       write_unlock_irqrestore(&capiminor_list_lock, flags);
+       write_lock_irqsave(&capiminors_lock, flags);
+       capiminors[mp->minor] = NULL;
+       write_unlock_irqrestore(&capiminors_lock, flags);
 
        kfree_skb(mp->ttyskb);
        mp->ttyskb = NULL;
@@ -279,20 +270,16 @@ static void capiminor_free(struct capiminor *mp)
 
 static struct capiminor *capiminor_find(unsigned int minor)
 {
-       struct list_head *l;
-       struct capiminor *p = NULL;
+       struct capiminor *mp;
 
-       read_lock(&capiminor_list_lock);
-       list_for_each(l, &capiminor_list) {
-               p = list_entry(l, struct capiminor, list);
-               if (p->minor == minor)
-                       break;
-       }
-       read_unlock(&capiminor_list_lock);
-       if (l == &capiminor_list)
+       if (minor >= capi_ttyminors)
                return NULL;
 
-       return p;
+       read_lock(&capiminors_lock);
+       mp = capiminors[minor];
+       read_unlock(&capiminors_lock);
+
+       return mp;
 }
 
 /* -------- struct capincci ----------------------------------------- */
@@ -1329,10 +1316,16 @@ static int capinc_tty_init(void)
        if (capi_ttyminors <= 0)
                capi_ttyminors = CAPINC_NR_PORTS;
 
-       drv = alloc_tty_driver(capi_ttyminors);
-       if (!drv)
+       capiminors = kzalloc(sizeof(struct capi_minor *) * capi_ttyminors,
+                            GFP_KERNEL);
+       if (!capiminors)
                return -ENOMEM;
 
+       drv = alloc_tty_driver(capi_ttyminors);
+       if (!drv) {
+               kfree(capiminors);
+               return -ENOMEM;
+       }
        drv->owner = THIS_MODULE;
        drv->driver_name = "capi_nc";
        drv->name = "capi";
@@ -1349,6 +1342,7 @@ static int capinc_tty_init(void)
        tty_set_operations(drv, &capinc_ops);
        if (tty_register_driver(drv)) {
                put_tty_driver(drv);
+               kfree(capiminors);
                printk(KERN_ERR "Couldn't register capi_nc driver\n");
                return -1;
        }
@@ -1363,6 +1357,7 @@ static void capinc_tty_exit(void)
        if ((retval = tty_unregister_driver(drv)))
                printk(KERN_ERR "capi: failed to unregister capi_nc driver (%d)\n", retval);
        put_tty_driver(drv);
+       kfree(capiminors);
 }
 
 #else /* !CONFIG_ISDN_CAPI_MIDDLEWARE */