summaryrefslogtreecommitdiff
path: root/fs/char_dev.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/char_dev.c')
-rw-r--r--fs/char_dev.c30
1 files changed, 14 insertions, 16 deletions
diff --git a/fs/char_dev.c b/fs/char_dev.c
index 21195c481637..4e1b849f912f 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -19,6 +19,7 @@
#include <linux/kobject.h>
#include <linux/kobj_map.h>
#include <linux/cdev.h>
+#include <linux/mutex.h>
#ifdef CONFIG_KMOD
#include <linux/kmod.h>
@@ -28,7 +29,7 @@ static struct kobj_map *cdev_map;
#define MAX_PROBE_HASH 255 /* random */
-static DECLARE_MUTEX(chrdevs_lock);
+static DEFINE_MUTEX(chrdevs_lock);
static struct char_device_struct {
struct char_device_struct *next;
@@ -88,13 +89,13 @@ out:
void *acquire_chrdev_list(void)
{
- down(&chrdevs_lock);
+ mutex_lock(&chrdevs_lock);
return get_next_chrdev(NULL);
}
void release_chrdev_list(void *dev)
{
- up(&chrdevs_lock);
+ mutex_unlock(&chrdevs_lock);
kfree(dev);
}
@@ -145,13 +146,11 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
int ret = 0;
int i;
- cd = kmalloc(sizeof(struct char_device_struct), GFP_KERNEL);
+ cd = kzalloc(sizeof(struct char_device_struct), GFP_KERNEL);
if (cd == NULL)
return ERR_PTR(-ENOMEM);
- memset(cd, 0, sizeof(struct char_device_struct));
-
- down(&chrdevs_lock);
+ mutex_lock(&chrdevs_lock);
/* temporary */
if (major == 0) {
@@ -186,10 +185,10 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
}
cd->next = *cp;
*cp = cd;
- up(&chrdevs_lock);
+ mutex_unlock(&chrdevs_lock);
return cd;
out:
- up(&chrdevs_lock);
+ mutex_unlock(&chrdevs_lock);
kfree(cd);
return ERR_PTR(ret);
}
@@ -200,7 +199,7 @@ __unregister_chrdev_region(unsigned major, unsigned baseminor, int minorct)
struct char_device_struct *cd = NULL, **cp;
int i = major_to_index(major);
- down(&chrdevs_lock);
+ mutex_lock(&chrdevs_lock);
for (cp = &chrdevs[i]; *cp; cp = &(*cp)->next)
if ((*cp)->major == major &&
(*cp)->baseminor == baseminor &&
@@ -210,7 +209,7 @@ __unregister_chrdev_region(unsigned major, unsigned baseminor, int minorct)
cd = *cp;
*cp = cd->next;
}
- up(&chrdevs_lock);
+ mutex_unlock(&chrdevs_lock);
return cd;
}
@@ -251,7 +250,7 @@ int alloc_chrdev_region(dev_t *dev, unsigned baseminor, unsigned count,
}
int register_chrdev(unsigned int major, const char *name,
- struct file_operations *fops)
+ const struct file_operations *fops)
{
struct char_device_struct *cd;
struct cdev *cdev;
@@ -407,7 +406,7 @@ static void cdev_purge(struct cdev *cdev)
* is contain the open that then fills in the correct operations
* depending on the special file...
*/
-struct file_operations def_chr_fops = {
+const struct file_operations def_chr_fops = {
.open = chrdev_open,
};
@@ -465,9 +464,8 @@ static struct kobj_type ktype_cdev_dynamic = {
struct cdev *cdev_alloc(void)
{
- struct cdev *p = kmalloc(sizeof(struct cdev), GFP_KERNEL);
+ struct cdev *p = kzalloc(sizeof(struct cdev), GFP_KERNEL);
if (p) {
- memset(p, 0, sizeof(struct cdev));
p->kobj.ktype = &ktype_cdev_dynamic;
INIT_LIST_HEAD(&p->list);
kobject_init(&p->kobj);
@@ -475,7 +473,7 @@ struct cdev *cdev_alloc(void)
return p;
}
-void cdev_init(struct cdev *cdev, struct file_operations *fops)
+void cdev_init(struct cdev *cdev, const struct file_operations *fops)
{
memset(cdev, 0, sizeof *cdev);
INIT_LIST_HEAD(&cdev->list);