[PATCH v2 19/41] CAPI: Switch capiminor list to array

From: Jan Kiszka
Date: Mon Feb 08 2010 - 15:18:52 EST


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

Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxx>
---
drivers/isdn/capi/capi.c | 75 +++++++++++++++++++++------------------------
1 files changed, 35 insertions(+), 40 deletions(-)

diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index 6704b2b..46f85ae 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 */
--
1.6.0.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/