Misc: Add possibility to remove misc devices during suspend/resume

[linux-2.6-omap-h63xx.git] / drivers / char / misc.c

diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index 7e975f606924e04b6d24eef36707cbc97723cebc..a39101feb2ed8f70ff57f5d74e1a05855bec959d 100644 (file)
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -41,6 +41,7 @@
 #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>
@@ -53,7 +54,7 @@
  * 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
@@ -66,35 +67,23 @@ extern int pmu_device_init(void);
 #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;
@@ -129,7 +118,7 @@ static int misc_open(struct inode * inode, struct file * file)
        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) {
@@ -139,9 +128,9 @@ 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) {
@@ -165,7 +154,7 @@ static int misc_open(struct inode * inode, struct file * file)
        }
        fops_put(old_fops);
 fail:
-       up(&misc_sem);
+       mutex_unlock(&misc_mtx);
        return err;
 }
 
@@ -201,10 +190,10 @@ int misc_register(struct miscdevice * misc)
 
        INIT_LIST_HEAD(&misc->list);
 
-       down(&misc_sem);
+       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;
                }
        }
@@ -215,7 +204,7 @@ int misc_register(struct miscdevice * misc)
                        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;
@@ -238,13 +227,14 @@ int misc_register(struct miscdevice * misc)
         */
        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
@@ -252,25 +242,29 @@ int misc_register(struct miscdevice * misc)
  *     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)
 {