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60e64d46 VG |
1 | /* |
2 | * kernel/crash_dump.c - Memory preserving reboot related code. | |
3 | * | |
4 | * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) | |
5 | * Copyright (C) IBM Corporation, 2004. All rights reserved | |
6 | */ | |
7 | ||
8 | #include <linux/smp_lock.h> | |
9 | #include <linux/errno.h> | |
10 | #include <linux/proc_fs.h> | |
11 | #include <linux/bootmem.h> | |
12 | #include <linux/highmem.h> | |
13 | #include <linux/crash_dump.h> | |
14 | ||
15 | #include <asm/io.h> | |
16 | #include <asm/uaccess.h> | |
54c32021 | 17 | #include <asm/kexec.h> |
60e64d46 | 18 | |
2030eae5 | 19 | /* Stores the physical address of elf header of crash image. */ |
666bfddb | 20 | unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; |
2030eae5 | 21 | |
54c32021 | 22 | #ifndef HAVE_ARCH_COPY_OLDMEM_PAGE |
e77e1716 RD |
23 | /** |
24 | * copy_oldmem_page - copy one page from "oldmem" | |
25 | * @pfn: page frame number to be copied | |
26 | * @buf: target memory address for the copy; this can be in kernel address | |
27 | * space or user address space (see @userbuf) | |
28 | * @csize: number of bytes to copy | |
29 | * @offset: offset in bytes into the page (based on pfn) to begin the copy | |
30 | * @userbuf: if set, @buf is in user address space, use copy_to_user(), | |
31 | * otherwise @buf is in kernel address space, use memcpy(). | |
32 | * | |
60e64d46 VG |
33 | * Copy a page from "oldmem". For this page, there is no pte mapped |
34 | * in the current kernel. We stitch up a pte, similar to kmap_atomic. | |
35 | */ | |
36 | ssize_t copy_oldmem_page(unsigned long pfn, char *buf, | |
37 | size_t csize, unsigned long offset, int userbuf) | |
38 | { | |
39 | void *page, *vaddr; | |
40 | ||
41 | if (!csize) | |
42 | return 0; | |
43 | ||
44 | page = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
45 | if (!page) | |
46 | return -ENOMEM; | |
47 | ||
48 | vaddr = kmap_atomic_pfn(pfn, KM_PTE0); | |
49 | copy_page(page, vaddr); | |
50 | kunmap_atomic(vaddr, KM_PTE0); | |
51 | ||
52 | if (userbuf) { | |
53 | if (copy_to_user(buf, (page + offset), csize)) { | |
54 | kfree(page); | |
55 | return -EFAULT; | |
56 | } | |
57 | } else { | |
58 | memcpy(buf, (page + offset), csize); | |
59 | } | |
60 | ||
61 | kfree(page); | |
62 | return csize; | |
63 | } | |
54c32021 | 64 | #endif |