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>

1 files changed, 35 insertions, 40 deletions

diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index 6704b2b004aa..46f85ae85f5f 100644
--- 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 */