From 1848d7bbcdb01b82188b6058421736c504c6e582 Mon Sep 17 00:00:00 2001
From: Stephen Hemminger <shemminger@osdl.org>
Date: Tue, 16 Sep 2003 23:56:30 -0700
Subject: [PATCH] [PATCH] drivers/char/misc -- use list() macros

Use list macros for misc_device list.
---
 drivers/char/misc.c        | 63 +++++++++++++++++++-------------------
 include/linux/miscdevice.h |  2 +-
 2 files changed, 32 insertions(+), 33 deletions(-)

diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index 8cc75c28a105d..0b085986cd972 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -53,7 +53,7 @@
 /*
  * Head entry for the doubly linked miscdevice list
  */
-static struct miscdevice misc_list = { 0, "head", NULL, &misc_list, &misc_list };
+static LIST_HEAD(misc_list);
 static DECLARE_MUTEX(misc_sem);
 
 /*
@@ -80,7 +80,9 @@ static int misc_read_proc(char *buf, char **start, off_t offset,
 	int written;
 
 	written=0;
-	for (p = misc_list.next; p != &misc_list && written < len; p = p->next) {
+	list_for_each_entry(p, &misc_list, list) {
+		if (written >= len)
+			break;
 		written += sprintf(buf+written, "%3i %s\n",p->minor, p->name ?: "");
 		if (written < offset) {
 			offset -= written;
@@ -97,7 +99,6 @@ static int misc_read_proc(char *buf, char **start, off_t offset,
 	return (written<0) ? 0 : written;
 }
 
-
 static int misc_open(struct inode * inode, struct file * file)
 {
 	int minor = iminor(inode);
@@ -107,21 +108,27 @@ static int misc_open(struct inode * inode, struct file * file)
 	
 	down(&misc_sem);
 	
-	c = misc_list.next;
-
-	while ((c != &misc_list) && (c->minor != minor))
-		c = c->next;
-	if (c != &misc_list)
-		new_fops = fops_get(c->fops);
+	list_for_each_entry(c, &misc_list, list) {
+		if (c->minor == minor) {
+			new_fops = fops_get(c->fops);		
+			break;
+		}
+	}
+		
 	if (!new_fops) {
 		up(&misc_sem);
 		request_module("char-major-%d-%d", MISC_MAJOR, minor);
 		down(&misc_sem);
-		c = misc_list.next;
-		while ((c != &misc_list) && (c->minor != minor))
-			c = c->next;
-		if (c == &misc_list || (new_fops = fops_get(c->fops)) == NULL)
-			goto fail;
+
+		list_for_each_entry(c, &misc_list, list) {
+			if (c->minor == minor) {
+				new_fops = fops_get(c->fops);
+				if (!new_fops)
+					goto fail;
+				break;
+			}
+		}
+		goto fail;
 	}
 
 	err = 0;
@@ -166,16 +173,12 @@ int misc_register(struct miscdevice * misc)
 {
 	struct miscdevice *c;
 	
-	if (misc->next || misc->prev)
-		return -EBUSY;
 	down(&misc_sem);
-	c = misc_list.next;
-
-	while ((c != &misc_list) && (c->minor != misc->minor))
-		c = c->next;
-	if (c != &misc_list) {
-		up(&misc_sem);
-		return -EBUSY;
+	list_for_each_entry(c, &misc_list, list) {
+		if (c->minor == misc->minor) {
+			up(&misc_sem);
+			return -EBUSY;
+		}
 	}
 
 	if (misc->minor == MISC_DYNAMIC_MINOR) {
@@ -205,10 +208,7 @@ int misc_register(struct miscdevice * misc)
 	 * Add it to the front, so that later devices can "override"
 	 * earlier defaults
 	 */
-	misc->prev = &misc_list;
-	misc->next = misc_list.next;
-	misc->prev->next = misc;
-	misc->next->prev = misc;
+	list_add(&misc->list, &misc_list);
 	up(&misc_sem);
 	return 0;
 }
@@ -226,13 +226,12 @@ int misc_register(struct miscdevice * misc)
 int misc_deregister(struct miscdevice * misc)
 {
 	int i = misc->minor;
-	if (!misc->next || !misc->prev)
+
+	if (list_empty(&misc->list))
 		return -EINVAL;
+
 	down(&misc_sem);
-	misc->prev->next = misc->next;
-	misc->next->prev = misc->prev;
-	misc->next = NULL;
-	misc->prev = NULL;
+	list_del(&misc->list);
 	devfs_remove(misc->devfs_name);
 	if (i < DYNAMIC_MINORS && i>0) {
 		misc_minors[i>>3] &= ~(1 << (misc->minor & 7));
diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h
index 23b0958891116..d3af913515211 100644
--- a/include/linux/miscdevice.h
+++ b/include/linux/miscdevice.h
@@ -43,7 +43,7 @@ struct miscdevice
 	int minor;
 	const char *name;
 	struct file_operations *fops;
-	struct miscdevice * next, * prev;
+	struct list_head list;
 	char devfs_name[64];
 };
 
-- 
2.53.0