1 files changed, 75 insertions, 7 deletions

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 467a4f177bfb..b177e750efc3 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -2,12 +2,14 @@
  * Core registration and callback routines for MTD
  * drivers and users.
  *
+ * bdi bits are:
+ * Copyright © 2006 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
  */
 
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/ptrace.h>
-#include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/timer.h>
 #include <linux/major.h>
@@ -17,11 +19,39 @@
 #include <linux/init.h>
 #include <linux/mtd/compatmac.h>
 #include <linux/proc_fs.h>
+#include <linux/backing-dev.h>
 
 #include <linux/mtd/mtd.h>
-#include "internal.h"
 
 #include "mtdcore.h"
+/*
+ * backing device capabilities for non-mappable devices (such as NAND flash)
+ * - permits private mappings, copies are taken of the data
+ */
+struct backing_dev_info mtd_bdi_unmappable = {
+        .capabilities   = BDI_CAP_MAP_COPY,
+};
+
+/*
+ * backing device capabilities for R/O mappable devices (such as ROM)
+ * - permits private mappings, copies are taken of the data
+ * - permits non-writable shared mappings
+ */
+struct backing_dev_info mtd_bdi_ro_mappable = {
+        .capabilities   = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
+                           BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP),
+};
+
+/*
+ * backing device capabilities for writable mappable devices (such as RAM)
+ * - permits private mappings, copies are taken of the data
+ * - permits non-writable shared mappings
+ */
+struct backing_dev_info mtd_bdi_rw_mappable = {
+        .capabilities   = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
+                           BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
+                           BDI_CAP_WRITE_MAP),
+};
 
 static int mtd_cls_suspend(struct device *dev, pm_message_t state);
 static int mtd_cls_resume(struct device *dev);
@@ -447,7 +477,7 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
                 for (i=0; i< MAX_MTD_DEVICES; i++)
                         if (mtd_table[i] == mtd)
                                 ret = mtd_table[i];
-        } else if (num < MAX_MTD_DEVICES) {
+        } else if (num >= 0 && num < MAX_MTD_DEVICES) {
                 ret = mtd_table[num];
                 if (mtd && mtd != ret)
                         ret = NULL;
@@ -629,20 +659,55 @@ done:
 /*====================================================================*/
 /* Init code */
 
+static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
+{
+        int ret;
+
+        ret = bdi_init(bdi);
+        if (!ret)
+                ret = bdi_register(bdi, NULL, name);
+
+        if (ret)
+                bdi_destroy(bdi);
+
+        return ret;
+}
+
 static int __init init_mtd(void)
 {
         int ret;
+
         ret = class_register(&mtd_class);
+        if (ret)
+                goto err_reg;
+
+        ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
+        if (ret)
+                goto err_bdi1;
+
+        ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
+        if (ret)
+                goto err_bdi2;
+
+        ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
+        if (ret)
+                goto err_bdi3;
 
-        if (ret) {
-                pr_err("Error registering mtd class: %d\n", ret);
-                return ret;
-        }
 #ifdef CONFIG_PROC_FS
         if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
                 proc_mtd->read_proc = mtd_read_proc;
 #endif /* CONFIG_PROC_FS */
         return 0;
+
+err_bdi3:
+        bdi_destroy(&mtd_bdi_ro_mappable);
+err_bdi2:
+        bdi_destroy(&mtd_bdi_unmappable);
+err_bdi1:
+        class_unregister(&mtd_class);
+err_reg:
+        pr_err("Error registering mtd class or bdi: %d\n", ret);
+        return ret;
 }
 
 static void __exit cleanup_mtd(void)
@@ -652,6 +717,9 @@ static void __exit cleanup_mtd(void)
                 remove_proc_entry( "mtd", NULL);
 #endif /* CONFIG_PROC_FS */
         class_unregister(&mtd_class);
+        bdi_destroy(&mtd_bdi_unmappable);
+        bdi_destroy(&mtd_bdi_ro_mappable);
+        bdi_destroy(&mtd_bdi_rw_mappable);
 }
 
 module_init(init_mtd);