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67742c81 MW |
1 | /* |
2 | * arch/arm/kernel/crash_dump.c | |
3 | * | |
4 | * Copyright (C) 2010 Nokia Corporation. | |
5 | * Author: Mika Westerberg | |
6 | * | |
7 | * This code is taken from arch/x86/kernel/crash_dump_64.c | |
8 | * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) | |
9 | * Copyright (C) IBM Corporation, 2004. All rights reserved | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License version 2 as | |
13 | * published by the Free Software Foundation. | |
14 | */ | |
15 | ||
16 | #include <linux/errno.h> | |
17 | #include <linux/crash_dump.h> | |
18 | #include <linux/uaccess.h> | |
19 | #include <linux/io.h> | |
20 | ||
67742c81 MW |
21 | /** |
22 | * copy_oldmem_page() - copy one page from old kernel memory | |
23 | * @pfn: page frame number to be copied | |
24 | * @buf: buffer where the copied page is placed | |
25 | * @csize: number of bytes to copy | |
26 | * @offset: offset in bytes into the page | |
27 | * @userbuf: if set, @buf is int he user address space | |
28 | * | |
29 | * This function copies one page from old kernel memory into buffer pointed by | |
30 | * @buf. If @buf is in userspace, set @userbuf to %1. Returns number of bytes | |
31 | * copied or negative error in case of failure. | |
32 | */ | |
33 | ssize_t copy_oldmem_page(unsigned long pfn, char *buf, | |
34 | size_t csize, unsigned long offset, | |
35 | int userbuf) | |
36 | { | |
37 | void *vaddr; | |
38 | ||
39 | if (!csize) | |
40 | return 0; | |
41 | ||
8fad87bc | 42 | vaddr = ioremap(__pfn_to_phys(pfn), PAGE_SIZE); |
67742c81 MW |
43 | if (!vaddr) |
44 | return -ENOMEM; | |
45 | ||
46 | if (userbuf) { | |
47 | if (copy_to_user(buf, vaddr + offset, csize)) { | |
48 | iounmap(vaddr); | |
49 | return -EFAULT; | |
50 | } | |
51 | } else { | |
52 | memcpy(buf, vaddr + offset, csize); | |
53 | } | |
54 | ||
55 | iounmap(vaddr); | |
56 | return csize; | |
57 | } |