#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/slab.h>
+#include <linux/mutex.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/stat.h>
* Head entry for the doubly linked miscdevice list
*/
static LIST_HEAD(misc_list);
-static DECLARE_MUTEX(misc_sem);
+static DEFINE_MUTEX(misc_mtx);
/*
* Assigned numbers, used for dynamic minors
#ifdef CONFIG_PROC_FS
static void *misc_seq_start(struct seq_file *seq, loff_t *pos)
{
- struct miscdevice *p;
- loff_t off = 0;
-
- down(&misc_sem);
- list_for_each_entry(p, &misc_list, list) {
- if (*pos == off++)
- return p;
- }
- return NULL;
+ mutex_lock(&misc_mtx);
+ return seq_list_start(&misc_list, *pos);
}
static void *misc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
- struct list_head *n = ((struct miscdevice *)v)->list.next;
-
- ++*pos;
-
- return (n != &misc_list) ? list_entry(n, struct miscdevice, list)
- : NULL;
+ return seq_list_next(v, &misc_list, pos);
}
static void misc_seq_stop(struct seq_file *seq, void *v)
{
- up(&misc_sem);
+ mutex_unlock(&misc_mtx);
}
static int misc_seq_show(struct seq_file *seq, void *v)
{
- const struct miscdevice *p = v;
+ const struct miscdevice *p = list_entry(v, struct miscdevice, list);
seq_printf(seq, "%3i %s\n", p->minor, p->name ? p->name : "");
return 0;
int err = -ENODEV;
const struct file_operations *old_fops, *new_fops = NULL;
- down(&misc_sem);
+ mutex_lock(&misc_mtx);
list_for_each_entry(c, &misc_list, list) {
if (c->minor == minor) {
}
if (!new_fops) {
- up(&misc_sem);
+ mutex_unlock(&misc_mtx);
request_module("char-major-%d-%d", MISC_MAJOR, minor);
- down(&misc_sem);
+ mutex_lock(&misc_mtx);
list_for_each_entry(c, &misc_list, list) {
if (c->minor == minor) {
}
fops_put(old_fops);
fail:
- up(&misc_sem);
+ mutex_unlock(&misc_mtx);
return err;
}
dev_t dev;
int err = 0;
- down(&misc_sem);
+ INIT_LIST_HEAD(&misc->list);
+
+ mutex_lock(&misc_mtx);
list_for_each_entry(c, &misc_list, list) {
if (c->minor == misc->minor) {
- up(&misc_sem);
+ mutex_unlock(&misc_mtx);
return -EBUSY;
}
}
if ( (misc_minors[i>>3] & (1 << (i&7))) == 0)
break;
if (i<0) {
- up(&misc_sem);
+ mutex_unlock(&misc_mtx);
return -EBUSY;
}
misc->minor = i;
*/
list_add(&misc->list, &misc_list);
out:
- up(&misc_sem);
+ mutex_unlock(&misc_mtx);
return err;
}
/**
- * misc_deregister - unregister a miscellaneous device
+ * __misc_deregister - unregister a miscellaneous device
* @misc: device to unregister
+ * @suspended: to be set if the function is used during suspend/resume
*
* Unregister a miscellaneous device that was previously
* successfully registered with misc_register(). Success
* indicates an error.
*/
-int misc_deregister(struct miscdevice * misc)
+int __misc_deregister(struct miscdevice *misc, bool suspended)
{
int i = misc->minor;
if (list_empty(&misc->list))
return -EINVAL;
- down(&misc_sem);
+ mutex_lock(&misc_mtx);
list_del(&misc->list);
- device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor));
+ if (suspended)
+ destroy_suspended_device(misc_class,
+ MKDEV(MISC_MAJOR, misc->minor));
+ else
+ device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor));
if (i < DYNAMIC_MINORS && i>0) {
misc_minors[i>>3] &= ~(1 << (misc->minor & 7));
}
- up(&misc_sem);
+ mutex_unlock(&misc_mtx);
return 0;
}
EXPORT_SYMBOL(misc_register);
-EXPORT_SYMBOL(misc_deregister);
+EXPORT_SYMBOL(__misc_deregister);
static int __init misc_init(void)
{