ia64/linux-2.6.18-xen.hg

view drivers/mtd/mtdblock_ro.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
1 /*
2 * $Id: mtdblock_ro.c,v 1.19 2004/11/16 18:28:59 dwmw2 Exp $
3 *
4 * (C) 2003 David Woodhouse <dwmw2@infradead.org>
5 *
6 * Simple read-only (writable only for RAM) mtdblock driver
7 */
9 #include <linux/init.h>
10 #include <linux/slab.h>
11 #include <linux/mtd/mtd.h>
12 #include <linux/mtd/blktrans.h>
14 static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
15 unsigned long block, char *buf)
16 {
17 size_t retlen;
19 if (dev->mtd->read(dev->mtd, (block * 512), 512, &retlen, buf))
20 return 1;
21 return 0;
22 }
24 static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
25 unsigned long block, char *buf)
26 {
27 size_t retlen;
29 if (dev->mtd->write(dev->mtd, (block * 512), 512, &retlen, buf))
30 return 1;
31 return 0;
32 }
34 static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
35 {
36 struct mtd_blktrans_dev *dev = kmalloc(sizeof(*dev), GFP_KERNEL);
38 if (!dev)
39 return;
41 memset(dev, 0, sizeof(*dev));
43 dev->mtd = mtd;
44 dev->devnum = mtd->index;
45 dev->blksize = 512;
46 dev->size = mtd->size >> 9;
47 dev->tr = tr;
48 dev->readonly = 1;
50 add_mtd_blktrans_dev(dev);
51 }
53 static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
54 {
55 del_mtd_blktrans_dev(dev);
56 kfree(dev);
57 }
59 static struct mtd_blktrans_ops mtdblock_tr = {
60 .name = "mtdblock",
61 .major = 31,
62 .part_bits = 0,
63 .readsect = mtdblock_readsect,
64 .writesect = mtdblock_writesect,
65 .add_mtd = mtdblock_add_mtd,
66 .remove_dev = mtdblock_remove_dev,
67 .owner = THIS_MODULE,
68 };
70 static int __init mtdblock_init(void)
71 {
72 return register_mtd_blktrans(&mtdblock_tr);
73 }
75 static void __exit mtdblock_exit(void)
76 {
77 deregister_mtd_blktrans(&mtdblock_tr);
78 }
80 module_init(mtdblock_init);
81 module_exit(mtdblock_exit);
83 MODULE_LICENSE("GPL");
84 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
85 MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");