1 files changed, 84 insertions, 104 deletions

diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index 3e4c0414a01..ffa97d261cf 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -34,76 +34,61 @@
  */
 
 #include <linux/module.h>
-#include <linux/config.h>
 
 #include <linux/fs.h>
 #include <linux/errno.h>
 #include <linux/miscdevice.h>
 #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/devfs_fs_kernel.h>
 #include <linux/stat.h>
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/tty.h>
 #include <linux/kmod.h>
+#include <linux/gfp.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
  */
 #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)
 {
-	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;
 }
 
 
-static struct seq_operations misc_seq_ops = {
+static const struct seq_operations misc_seq_ops = {
 	.start = misc_seq_start,
 	.next  = misc_seq_next,
 	.stop  = misc_seq_stop,
@@ -115,7 +100,7 @@ static int misc_seq_open(struct inode *inode, struct file *file)
 	return seq_open(file, &misc_seq_ops);
 }
 
-static struct file_operations misc_proc_fops = {
+static const struct file_operations misc_proc_fops = {
 	.owner	 = THIS_MODULE,
 	.open    = misc_seq_open,
 	.read    = seq_read,
@@ -129,9 +114,9 @@ static int misc_open(struct inode * inode, struct file * file)
 	int minor = iminor(inode);
 	struct miscdevice *c;
 	int err = -ENODEV;
-	struct file_operations *old_fops, *new_fops = NULL;
-	
-	down(&misc_sem);
+	const struct file_operations *new_fops = NULL;
+
+	mutex_lock(&misc_mtx);
 	
 	list_for_each_entry(c, &misc_list, list) {
 		if (c->minor == minor) {
@@ -141,9 +126,9 @@ static int misc_open(struct inode * inode, struct file * file)
 	}
 		
 	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) {
@@ -156,34 +141,24 @@ static int misc_open(struct inode * inode, struct file * file)
 	}
 
 	err = 0;
-	old_fops = file->f_op;
-	file->f_op = new_fops;
+	replace_fops(file, new_fops);
 	if (file->f_op->open) {
-		err=file->f_op->open(inode,file);
-		if (err) {
-			fops_put(file->f_op);
-			file->f_op = fops_get(old_fops);
-		}
+		file->private_data = c;
+		err = file->f_op->open(inode,file);
 	}
-	fops_put(old_fops);
 fail:
-	up(&misc_sem);
+	mutex_unlock(&misc_mtx);
 	return err;
 }
 
-/* 
- * TODO for 2.7:
- *  - add a struct kref to struct miscdevice and make all usages of
- *    them dynamic.
- */
 static struct class *misc_class;
 
-static struct file_operations misc_fops = {
+static const struct file_operations misc_fops = {
 	.owner		= THIS_MODULE,
 	.open		= misc_open,
+	.llseek		= noop_llseek,
 };
 
-
 /**
  *	misc_register	-	register a miscellaneous device
  *	@misc: device structure
@@ -202,49 +177,41 @@ static struct file_operations misc_fops = {
  
 int misc_register(struct miscdevice * misc)
 {
-	struct miscdevice *c;
 	dev_t dev;
-	int err;
+	int err = 0;
 
-	down(&misc_sem);
-	list_for_each_entry(c, &misc_list, list) {
-		if (c->minor == misc->minor) {
-			up(&misc_sem);
-			return -EBUSY;
-		}
-	}
+	INIT_LIST_HEAD(&misc->list);
+
+	mutex_lock(&misc_mtx);
 
 	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) {
-			up(&misc_sem);
-			return -EBUSY;
+		int i = find_first_zero_bit(misc_minors, DYNAMIC_MINORS);
+		if (i >= DYNAMIC_MINORS) {
+			err = -EBUSY;
+			goto out;
 		}
-		misc->minor = i;
-	}
+		misc->minor = DYNAMIC_MINORS - i - 1;
+		set_bit(i, misc_minors);
+	} else {
+		struct miscdevice *c;
 
-	if (misc->minor < DYNAMIC_MINORS)
-		misc_minors[misc->minor >> 3] |= 1 << (misc->minor & 7);
-	if (misc->devfs_name[0] == '\0') {
-		snprintf(misc->devfs_name, sizeof(misc->devfs_name),
-				"misc/%s", misc->name);
+		list_for_each_entry(c, &misc_list, list) {
+			if (c->minor == misc->minor) {
+				err = -EBUSY;
+				goto out;
+			}
+		}
 	}
-	dev = MKDEV(MISC_MAJOR, misc->minor);
 
-	misc->class = class_device_create(misc_class, NULL, dev, misc->dev,
-					  "%s", misc->name);
-	if (IS_ERR(misc->class)) {
-		err = PTR_ERR(misc->class);
-		goto out;
-	}
+	dev = MKDEV(MISC_MAJOR, misc->minor);
 
-	err = devfs_mk_cdev(dev, S_IFCHR|S_IRUSR|S_IWUSR|S_IRGRP, 
-			    misc->devfs_name);
-	if (err) {
-		class_device_destroy(misc_class, dev);
+	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;
 	}
 
@@ -254,7 +221,7 @@ int misc_register(struct miscdevice * misc)
 	 */
 	list_add(&misc->list, &misc_list);
  out:
-	up(&misc_sem);
+	mutex_unlock(&misc_mtx);
 	return err;
 }
 
@@ -268,46 +235,59 @@ int misc_register(struct miscdevice * misc)
  *	indicates an error.
  */
 
-int misc_deregister(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))
+	if (WARN_ON(list_empty(&misc->list)))
 		return -EINVAL;
 
-	down(&misc_sem);
+	mutex_lock(&misc_mtx);
 	list_del(&misc->list);
-	class_device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor));
-	devfs_remove(misc->devfs_name);
-	if (i < DYNAMIC_MINORS && i>0) {
-		misc_minors[i>>3] &= ~(1 << (misc->minor & 7));
-	}
-	up(&misc_sem);
+	device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor));
+	if (i < DYNAMIC_MINORS && i >= 0)
+		clear_bit(i, misc_minors);
+	mutex_unlock(&misc_mtx);
 	return 0;
 }
 
 EXPORT_SYMBOL(misc_register);
 EXPORT_SYMBOL(misc_deregister);
 
+static char *misc_devnode(struct device *dev, umode_t *mode)
+{
+	struct miscdevice *c = dev_get_drvdata(dev);
+
+	if (mode && c->mode)
+		*mode = c->mode;
+	if (c->nodename)
+		return kstrdup(c->nodename, GFP_KERNEL);
+	return NULL;
+}
+
 static int __init misc_init(void)
 {
-#ifdef CONFIG_PROC_FS
-	struct proc_dir_entry *ent;
+	int err;
 
-	ent = create_proc_entry("misc", 0, NULL);
-	if (ent)
-		ent->proc_fops = &misc_proc_fops;
+#ifdef CONFIG_PROC_FS
+	proc_create("misc", 0, NULL, &misc_proc_fops);
 #endif
 	misc_class = class_create(THIS_MODULE, "misc");
+	err = PTR_ERR(misc_class);
 	if (IS_ERR(misc_class))
-		return PTR_ERR(misc_class);
+		goto fail_remove;
 
-	if (register_chrdev(MISC_MAJOR,"misc",&misc_fops)) {
-		printk("unable to get major %d for misc devices\n",
-		       MISC_MAJOR);
-		class_destroy(misc_class);
-		return -EIO;
-	}
+	err = -EIO;
+	if (register_chrdev(MISC_MAJOR,"misc",&misc_fops))
+		goto fail_printk;
+	misc_class->devnode = misc_devnode;
 	return 0;
+
+fail_printk:
+	printk("unable to get major %d for misc devices\n", MISC_MAJOR);
+	class_destroy(misc_class);
+fail_remove:
+	remove_proc_entry("misc", NULL);
+	return err;
 }
 subsys_initcall(misc_init);