1 files changed, 69 insertions, 42 deletions

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index e9ec59e9a566..763d3f0a1f42 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -13,39 +13,13 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
 
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/compatmac.h>
 
 #include <asm/uaccess.h>
 
-static struct class *mtd_class;
-
-static void mtd_notify_add(struct mtd_info* mtd)
-{
-        if (!mtd)
-                return;
-
-        device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
-                      NULL, "mtd%d", mtd->index);
-
-        device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
-                      NULL, "mtd%dro", mtd->index);
-}
-
-static void mtd_notify_remove(struct mtd_info* mtd)
-{
-        if (!mtd)
-                return;
-
-        device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
-        device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
-}
-
-static struct mtd_notifier notifier = {
-        .add    = mtd_notify_add,
-        .remove = mtd_notify_remove,
-};
 
 /*
  * Data structure to hold the pointer to the mtd device as well
@@ -107,12 +81,15 @@ static int mtd_open(struct inode *inode, struct file *file)
                 goto out;
         }
 
-        if (MTD_ABSENT == mtd->type) {
+        if (mtd->type == MTD_ABSENT) {
                 put_mtd_device(mtd);
                 ret = -ENODEV;
                 goto out;
         }
 
+        if (mtd->backing_dev_info)
+                file->f_mapping->backing_dev_info = mtd->backing_dev_info;
+
         /* You can't open it RW if it's not a writeable device */
         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
                 put_mtd_device(mtd);
@@ -781,6 +758,59 @@ static int mtd_ioctl(struct inode *inode, struct file *file,
         return ret;
 } /* memory_ioctl */
 
+/*
+ * try to determine where a shared mapping can be made
+ * - only supported for NOMMU at the moment (MMU can't doesn't copy private
+ *   mappings)
+ */
+#ifndef CONFIG_MMU
+static unsigned long mtd_get_unmapped_area(struct file *file,
+                                           unsigned long addr,
+                                           unsigned long len,
+                                           unsigned long pgoff,
+                                           unsigned long flags)
+{
+        struct mtd_file_info *mfi = file->private_data;
+        struct mtd_info *mtd = mfi->mtd;
+
+        if (mtd->get_unmapped_area) {
+                unsigned long offset;
+
+                if (addr != 0)
+                        return (unsigned long) -EINVAL;
+
+                if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
+                        return (unsigned long) -EINVAL;
+
+                offset = pgoff << PAGE_SHIFT;
+                if (offset > mtd->size - len)
+                        return (unsigned long) -EINVAL;
+
+                return mtd->get_unmapped_area(mtd, len, offset, flags);
+        }
+
+        /* can't map directly */
+        return (unsigned long) -ENOSYS;
+}
+#endif
+
+/*
+ * set up a mapping for shared memory segments
+ */
+static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
+{
+#ifdef CONFIG_MMU
+        struct mtd_file_info *mfi = file->private_data;
+        struct mtd_info *mtd = mfi->mtd;
+
+        if (mtd->type == MTD_RAM || mtd->type == MTD_ROM)
+                return 0;
+        return -ENOSYS;
+#else
+        return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
+#endif
+}
+
 static const struct file_operations mtd_fops = {
         .owner          = THIS_MODULE,
         .llseek         = mtd_lseek,
@@ -789,39 +819,36 @@ static const struct file_operations mtd_fops = {
         .ioctl          = mtd_ioctl,
         .open           = mtd_open,
         .release        = mtd_close,
+        .mmap           = mtd_mmap,
+#ifndef CONFIG_MMU
+        .get_unmapped_area = mtd_get_unmapped_area,
+#endif
 };
 
 static int __init init_mtdchar(void)
 {
-        if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
+        int status;
+
+        status = register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops);
+        if (status < 0) {
                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
                        MTD_CHAR_MAJOR);
-                return -EAGAIN;
         }
 
-        mtd_class = class_create(THIS_MODULE, "mtd");
-
-        if (IS_ERR(mtd_class)) {
-                printk(KERN_ERR "Error creating mtd class.\n");
-                unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
-                return PTR_ERR(mtd_class);
-        }
-
-        register_mtd_user(&notifier);
-        return 0;
+        return status;
 }
 
 static void __exit cleanup_mtdchar(void)
 {
-        unregister_mtd_user(&notifier);
-        class_destroy(mtd_class);
         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 }
 
 module_init(init_mtdchar);
 module_exit(cleanup_mtdchar);
 
+MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
+MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);