1 files changed, 12 insertions, 19 deletions

diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index 07fa612a58d5..94a136e96c06 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -49,7 +49,6 @@
 #include <linux/device.h>
 #include <linux/tty.h>
 #include <linux/kmod.h>
-#include <linux/smp_lock.h>
 
 /*
  * Head entry for the doubly linked miscdevice list
@@ -61,9 +60,7 @@ static DEFINE_MUTEX(misc_mtx);
  * Assigned numbers, used for dynamic minors
  */
 #define DYNAMIC_MINORS 64 /* like dynamic majors */
-static unsigned char misc_minors[DYNAMIC_MINORS / 8];
-
-extern int pmu_device_init(void);
+static DECLARE_BITMAP(misc_minors, DYNAMIC_MINORS);
 
 #ifdef CONFIG_PROC_FS
 static void *misc_seq_start(struct seq_file *seq, loff_t *pos)
@@ -118,8 +115,7 @@ static int misc_open(struct inode * inode, struct file * file)
         struct miscdevice *c;
         int err = -ENODEV;
         const struct file_operations *old_fops, *new_fops = NULL;
-        
-        lock_kernel();
+
         mutex_lock(&misc_mtx);
         
         list_for_each_entry(c, &misc_list, list) {
@@ -157,7 +153,6 @@ static int misc_open(struct inode * inode, struct file * file)
         fops_put(old_fops);
 fail:
         mutex_unlock(&misc_mtx);
-        unlock_kernel();
         return err;
 }
 
@@ -201,24 +196,23 @@ int misc_register(struct miscdevice * misc)
         }
 
         if (misc->minor == MISC_DYNAMIC_MINOR) {
-                int i = DYNAMIC_MINORS;
-                while (--i >= 0)
-                        if ( (misc_minors[i>>3] & (1 << (i&7))) == 0)
-                                break;
-                if (i<0) {
+                int i = find_first_zero_bit(misc_minors, DYNAMIC_MINORS);
+                if (i >= DYNAMIC_MINORS) {
                         mutex_unlock(&misc_mtx);
                         return -EBUSY;
                 }
-                misc->minor = i;
+                misc->minor = DYNAMIC_MINORS - i - 1;
+                set_bit(i, misc_minors);
         }
 
-        if (misc->minor < DYNAMIC_MINORS)
-                misc_minors[misc->minor >> 3] |= 1 << (misc->minor & 7);
         dev = MKDEV(MISC_MAJOR, misc->minor);
 
         misc->this_device = device_create(misc_class, misc->parent, dev,
                                           misc, "%s", misc->name);
         if (IS_ERR(misc->this_device)) {
+                int i = DYNAMIC_MINORS - misc->minor - 1;
+                if (i < DYNAMIC_MINORS && i >= 0)
+                        clear_bit(i, misc_minors);
                 err = PTR_ERR(misc->this_device);
                 goto out;
         }
@@ -245,7 +239,7 @@ int misc_register(struct miscdevice * misc)
 
 int misc_deregister(struct miscdevice *misc)
 {
-        int i = misc->minor;
+        int i = DYNAMIC_MINORS - misc->minor - 1;
 
         if (list_empty(&misc->list))
                 return -EINVAL;
@@ -253,9 +247,8 @@ int misc_deregister(struct miscdevice *misc)
         mutex_lock(&misc_mtx);
         list_del(&misc->list);
         device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor));
-        if (i < DYNAMIC_MINORS && i>0) {
-                misc_minors[i>>3] &= ~(1 << (misc->minor & 7));
-        }
+        if (i < DYNAMIC_MINORS && i >= 0)
+                clear_bit(i, misc_minors);
         mutex_unlock(&misc_mtx);
         return 0;
 }