Commit | Line | Data |
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60e64d46 | 1 | /* |
835c34a1 | 2 | * Memory preserving reboot related code. |
60e64d46 VG |
3 | * |
4 | * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) | |
5 | * Copyright (C) IBM Corporation, 2004. All rights reserved | |
6 | */ | |
7 | ||
60e64d46 | 8 | #include <linux/errno.h> |
60e64d46 VG |
9 | #include <linux/crash_dump.h> |
10 | ||
60e64d46 | 11 | #include <asm/uaccess.h> |
4ae362be | 12 | #include <asm/io.h> |
2030eae5 | 13 | |
e77e1716 RD |
14 | /** |
15 | * copy_oldmem_page - copy one page from "oldmem" | |
16 | * @pfn: page frame number to be copied | |
17 | * @buf: target memory address for the copy; this can be in kernel address | |
18 | * space or user address space (see @userbuf) | |
19 | * @csize: number of bytes to copy | |
20 | * @offset: offset in bytes into the page (based on pfn) to begin the copy | |
21 | * @userbuf: if set, @buf is in user address space, use copy_to_user(), | |
22 | * otherwise @buf is in kernel address space, use memcpy(). | |
23 | * | |
60e64d46 VG |
24 | * Copy a page from "oldmem". For this page, there is no pte mapped |
25 | * in the current kernel. We stitch up a pte, similar to kmap_atomic. | |
26 | */ | |
27 | ssize_t copy_oldmem_page(unsigned long pfn, char *buf, | |
4ae362be | 28 | size_t csize, unsigned long offset, int userbuf) |
60e64d46 | 29 | { |
4ae362be | 30 | void *vaddr; |
60e64d46 VG |
31 | |
32 | if (!csize) | |
33 | return 0; | |
34 | ||
4ae362be | 35 | vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE); |
60e64d46 VG |
36 | |
37 | if (userbuf) { | |
4ae362be VG |
38 | if (copy_to_user(buf, (vaddr + offset), csize)) { |
39 | iounmap(vaddr); | |
60e64d46 VG |
40 | return -EFAULT; |
41 | } | |
4ae362be VG |
42 | } else |
43 | memcpy(buf, (vaddr + offset), csize); | |
60e64d46 | 44 | |
4ae362be | 45 | iounmap(vaddr); |
60e64d46 VG |
46 | return csize; |
47 | } |