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0cc4746c ME |
1 | /* |
2 | * Routines for doing kexec-based kdump. | |
3 | * | |
4 | * Copyright (C) 2005, IBM Corp. | |
5 | * | |
6 | * Created by: Michael Ellerman | |
7 | * | |
8 | * This source code is licensed under the GNU General Public License, | |
9 | * Version 2. See the file COPYING for more details. | |
10 | */ | |
11 | ||
12 | #undef DEBUG | |
13 | ||
cc532915 ME |
14 | #include <linux/crash_dump.h> |
15 | #include <linux/bootmem.h> | |
d9b2b2a2 | 16 | #include <linux/lmb.h> |
0cc4746c | 17 | #include <asm/kdump.h> |
d9b2b2a2 | 18 | #include <asm/prom.h> |
0cc4746c | 19 | #include <asm/firmware.h> |
54c32021 | 20 | #include <asm/uaccess.h> |
0cc4746c ME |
21 | |
22 | #ifdef DEBUG | |
23 | #include <asm/udbg.h> | |
24 | #define DBG(fmt...) udbg_printf(fmt) | |
25 | #else | |
26 | #define DBG(fmt...) | |
27 | #endif | |
28 | ||
d56c3aaa | 29 | void __init reserve_kdump_trampoline(void) |
47310413 ME |
30 | { |
31 | lmb_reserve(0, KDUMP_RESERVE_LIMIT); | |
32 | } | |
33 | ||
0cc4746c ME |
34 | static void __init create_trampoline(unsigned long addr) |
35 | { | |
36 | /* The maximum range of a single instruction branch, is the current | |
37 | * instruction's address + (32 MB - 4) bytes. For the trampoline we | |
38 | * need to branch to current address + 32 MB. So we insert a nop at | |
39 | * the trampoline address, then the next instruction (+ 4 bytes) | |
40 | * does a branch to (32 MB - 4). The net effect is that when we | |
41 | * branch to "addr" we jump to ("addr" + 32 MB). Although it requires | |
42 | * two instructions it doesn't require any registers. | |
43 | */ | |
44 | create_instruction(addr, 0x60000000); /* nop */ | |
45 | create_branch(addr + 4, addr + PHYSICAL_START, 0); | |
46 | } | |
47 | ||
47310413 | 48 | void __init setup_kdump_trampoline(void) |
0cc4746c ME |
49 | { |
50 | unsigned long i; | |
51 | ||
47310413 | 52 | DBG(" -> setup_kdump_trampoline()\n"); |
0cc4746c ME |
53 | |
54 | for (i = KDUMP_TRAMPOLINE_START; i < KDUMP_TRAMPOLINE_END; i += 8) { | |
55 | create_trampoline(i); | |
56 | } | |
57 | ||
9e4859ef | 58 | #ifdef CONFIG_PPC_PSERIES |
0cc4746c ME |
59 | create_trampoline(__pa(system_reset_fwnmi) - PHYSICAL_START); |
60 | create_trampoline(__pa(machine_check_fwnmi) - PHYSICAL_START); | |
9e4859ef | 61 | #endif /* CONFIG_PPC_PSERIES */ |
0cc4746c | 62 | |
47310413 | 63 | DBG(" <- setup_kdump_trampoline()\n"); |
0cc4746c | 64 | } |
cc532915 | 65 | |
6bac953f | 66 | #ifdef CONFIG_PROC_VMCORE |
cc532915 ME |
67 | static int __init parse_elfcorehdr(char *p) |
68 | { | |
69 | if (p) | |
70 | elfcorehdr_addr = memparse(p, &p); | |
71 | ||
9b41046c | 72 | return 1; |
cc532915 ME |
73 | } |
74 | __setup("elfcorehdr=", parse_elfcorehdr); | |
6bac953f | 75 | #endif |
cc532915 ME |
76 | |
77 | static int __init parse_savemaxmem(char *p) | |
78 | { | |
79 | if (p) | |
80 | saved_max_pfn = (memparse(p, &p) >> PAGE_SHIFT) - 1; | |
81 | ||
9b41046c | 82 | return 1; |
cc532915 ME |
83 | } |
84 | __setup("savemaxmem=", parse_savemaxmem); | |
54c32021 | 85 | |
40681b95 | 86 | /** |
54c32021 ME |
87 | * copy_oldmem_page - copy one page from "oldmem" |
88 | * @pfn: page frame number to be copied | |
89 | * @buf: target memory address for the copy; this can be in kernel address | |
90 | * space or user address space (see @userbuf) | |
91 | * @csize: number of bytes to copy | |
92 | * @offset: offset in bytes into the page (based on pfn) to begin the copy | |
93 | * @userbuf: if set, @buf is in user address space, use copy_to_user(), | |
94 | * otherwise @buf is in kernel address space, use memcpy(). | |
95 | * | |
96 | * Copy a page from "oldmem". For this page, there is no pte mapped | |
97 | * in the current kernel. We stitch up a pte, similar to kmap_atomic. | |
98 | */ | |
99 | ssize_t copy_oldmem_page(unsigned long pfn, char *buf, | |
100 | size_t csize, unsigned long offset, int userbuf) | |
101 | { | |
102 | void *vaddr; | |
103 | ||
104 | if (!csize) | |
105 | return 0; | |
106 | ||
107 | vaddr = __ioremap(pfn << PAGE_SHIFT, PAGE_SIZE, 0); | |
108 | ||
109 | if (userbuf) { | |
110 | if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) { | |
111 | iounmap(vaddr); | |
112 | return -EFAULT; | |
113 | } | |
114 | } else | |
115 | memcpy(buf, (vaddr + offset), csize); | |
116 | ||
117 | iounmap(vaddr); | |
118 | return csize; | |
119 | } |