Commit | Line | Data |
---|---|---|
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 | 9 | #include <linux/crash_dump.h> |
08aadf06 GP |
10 | #include <linux/uaccess.h> |
11 | #include <linux/io.h> | |
2030eae5 | 12 | |
e77e1716 RD |
13 | /** |
14 | * copy_oldmem_page - copy one page from "oldmem" | |
15 | * @pfn: page frame number to be copied | |
16 | * @buf: target memory address for the copy; this can be in kernel address | |
17 | * space or user address space (see @userbuf) | |
18 | * @csize: number of bytes to copy | |
19 | * @offset: offset in bytes into the page (based on pfn) to begin the copy | |
20 | * @userbuf: if set, @buf is in user address space, use copy_to_user(), | |
21 | * otherwise @buf is in kernel address space, use memcpy(). | |
22 | * | |
60e64d46 VG |
23 | * Copy a page from "oldmem". For this page, there is no pte mapped |
24 | * in the current kernel. We stitch up a pte, similar to kmap_atomic. | |
25 | */ | |
26 | ssize_t copy_oldmem_page(unsigned long pfn, char *buf, | |
08aadf06 | 27 | size_t csize, unsigned long offset, int userbuf) |
60e64d46 | 28 | { |
4ae362be | 29 | void *vaddr; |
60e64d46 VG |
30 | |
31 | if (!csize) | |
32 | return 0; | |
33 | ||
37a2f9f3 | 34 | vaddr = ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE); |
af2d237b AM |
35 | if (!vaddr) |
36 | return -ENOMEM; | |
60e64d46 VG |
37 | |
38 | if (userbuf) { | |
af2d237b | 39 | if (copy_to_user(buf, vaddr + offset, csize)) { |
4ae362be | 40 | iounmap(vaddr); |
60e64d46 VG |
41 | return -EFAULT; |
42 | } | |
4ae362be | 43 | } else |
af2d237b | 44 | memcpy(buf, vaddr + offset, csize); |
60e64d46 | 45 | |
3ee48b6a | 46 | set_iounmap_nonlazy(); |
4ae362be | 47 | iounmap(vaddr); |
60e64d46 VG |
48 | return csize; |
49 | } |