Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 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 | |
Michael Ellerman | cc53291 | 2005-12-04 18:39:43 +1100 | [diff] [blame] | 14 | #include <linux/crash_dump.h> |
| 15 | #include <linux/bootmem.h> |
David S. Miller | d9b2b2a | 2008-02-13 16:56:49 -0800 | [diff] [blame] | 16 | #include <linux/lmb.h> |
Michael Ellerman | aaddd3e | 2008-06-24 11:32:21 +1000 | [diff] [blame] | 17 | #include <asm/code-patching.h> |
Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 18 | #include <asm/kdump.h> |
David S. Miller | d9b2b2a | 2008-02-13 16:56:49 -0800 | [diff] [blame] | 19 | #include <asm/prom.h> |
Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 20 | #include <asm/firmware.h> |
Michael Ellerman | 54c3202 | 2005-12-04 18:39:51 +1100 | [diff] [blame] | 21 | #include <asm/uaccess.h> |
Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 22 | |
| 23 | #ifdef DEBUG |
| 24 | #include <asm/udbg.h> |
| 25 | #define DBG(fmt...) udbg_printf(fmt) |
| 26 | #else |
| 27 | #define DBG(fmt...) |
| 28 | #endif |
| 29 | |
Vivek Goyal | 57cac4d | 2008-10-18 20:28:25 -0700 | [diff] [blame] | 30 | /* Stores the physical address of elf header of crash image. */ |
| 31 | unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; |
| 32 | |
Mohan Kumar M | 54622f1 | 2008-10-21 17:38:10 +0000 | [diff] [blame] | 33 | #ifndef CONFIG_RELOCATABLE |
Stephen Rothwell | d56c3aa | 2007-08-15 20:53:26 +1000 | [diff] [blame] | 34 | void __init reserve_kdump_trampoline(void) |
Michael Ellerman | 4731041 | 2006-05-17 18:00:49 +1000 | [diff] [blame] | 35 | { |
| 36 | lmb_reserve(0, KDUMP_RESERVE_LIMIT); |
| 37 | } |
| 38 | |
Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 39 | static void __init create_trampoline(unsigned long addr) |
| 40 | { |
Michael Ellerman | e7a5727 | 2008-06-24 11:32:22 +1000 | [diff] [blame] | 41 | unsigned int *p = (unsigned int *)addr; |
| 42 | |
Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 43 | /* The maximum range of a single instruction branch, is the current |
| 44 | * instruction's address + (32 MB - 4) bytes. For the trampoline we |
| 45 | * need to branch to current address + 32 MB. So we insert a nop at |
| 46 | * the trampoline address, then the next instruction (+ 4 bytes) |
| 47 | * does a branch to (32 MB - 4). The net effect is that when we |
| 48 | * branch to "addr" we jump to ("addr" + 32 MB). Although it requires |
| 49 | * two instructions it doesn't require any registers. |
| 50 | */ |
Kumar Gala | 16c57b3 | 2009-02-10 20:10:44 +0000 | [diff] [blame] | 51 | patch_instruction(p, PPC_INST_NOP); |
Michael Ellerman | e7a5727 | 2008-06-24 11:32:22 +1000 | [diff] [blame] | 52 | patch_branch(++p, addr + PHYSICAL_START, 0); |
Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 53 | } |
| 54 | |
Michael Ellerman | 4731041 | 2006-05-17 18:00:49 +1000 | [diff] [blame] | 55 | void __init setup_kdump_trampoline(void) |
Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 56 | { |
| 57 | unsigned long i; |
| 58 | |
Michael Ellerman | 4731041 | 2006-05-17 18:00:49 +1000 | [diff] [blame] | 59 | DBG(" -> setup_kdump_trampoline()\n"); |
Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 60 | |
| 61 | for (i = KDUMP_TRAMPOLINE_START; i < KDUMP_TRAMPOLINE_END; i += 8) { |
| 62 | create_trampoline(i); |
| 63 | } |
| 64 | |
Stephen Rothwell | 9e4859e | 2007-09-18 17:25:12 +1000 | [diff] [blame] | 65 | #ifdef CONFIG_PPC_PSERIES |
Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 66 | create_trampoline(__pa(system_reset_fwnmi) - PHYSICAL_START); |
| 67 | create_trampoline(__pa(machine_check_fwnmi) - PHYSICAL_START); |
Stephen Rothwell | 9e4859e | 2007-09-18 17:25:12 +1000 | [diff] [blame] | 68 | #endif /* CONFIG_PPC_PSERIES */ |
Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 69 | |
Michael Ellerman | 4731041 | 2006-05-17 18:00:49 +1000 | [diff] [blame] | 70 | DBG(" <- setup_kdump_trampoline()\n"); |
Michael Ellerman | 0cc4746 | 2005-12-04 18:39:37 +1100 | [diff] [blame] | 71 | } |
Mohan Kumar M | 54622f1 | 2008-10-21 17:38:10 +0000 | [diff] [blame] | 72 | #endif /* CONFIG_RELOCATABLE */ |
Michael Ellerman | cc53291 | 2005-12-04 18:39:43 +1100 | [diff] [blame] | 73 | |
Vivek Goyal | 57cac4d | 2008-10-18 20:28:25 -0700 | [diff] [blame] | 74 | /* |
| 75 | * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by |
| 76 | * is_kdump_kernel() to determine if we are booting after a panic. Hence |
| 77 | * ifdef it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE. |
| 78 | */ |
Michael Ellerman | cc53291 | 2005-12-04 18:39:43 +1100 | [diff] [blame] | 79 | static int __init parse_elfcorehdr(char *p) |
| 80 | { |
| 81 | if (p) |
| 82 | elfcorehdr_addr = memparse(p, &p); |
| 83 | |
OGAWA Hirofumi | 9b41046 | 2006-03-31 02:30:33 -0800 | [diff] [blame] | 84 | return 1; |
Michael Ellerman | cc53291 | 2005-12-04 18:39:43 +1100 | [diff] [blame] | 85 | } |
| 86 | __setup("elfcorehdr=", parse_elfcorehdr); |
| 87 | |
| 88 | static int __init parse_savemaxmem(char *p) |
| 89 | { |
| 90 | if (p) |
| 91 | saved_max_pfn = (memparse(p, &p) >> PAGE_SHIFT) - 1; |
| 92 | |
OGAWA Hirofumi | 9b41046 | 2006-03-31 02:30:33 -0800 | [diff] [blame] | 93 | return 1; |
Michael Ellerman | cc53291 | 2005-12-04 18:39:43 +1100 | [diff] [blame] | 94 | } |
| 95 | __setup("savemaxmem=", parse_savemaxmem); |
Michael Ellerman | 54c3202 | 2005-12-04 18:39:51 +1100 | [diff] [blame] | 96 | |
Michael Ellerman | 7230ced | 2008-07-31 16:54:28 +1000 | [diff] [blame] | 97 | |
| 98 | static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize, |
| 99 | unsigned long offset, int userbuf) |
| 100 | { |
| 101 | if (userbuf) { |
| 102 | if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) |
| 103 | return -EFAULT; |
| 104 | } else |
| 105 | memcpy(buf, (vaddr + offset), csize); |
| 106 | |
| 107 | return csize; |
| 108 | } |
| 109 | |
Michael Ellerman | 40681b9 | 2006-08-02 11:13:50 +1000 | [diff] [blame] | 110 | /** |
Michael Ellerman | 54c3202 | 2005-12-04 18:39:51 +1100 | [diff] [blame] | 111 | * copy_oldmem_page - copy one page from "oldmem" |
| 112 | * @pfn: page frame number to be copied |
| 113 | * @buf: target memory address for the copy; this can be in kernel address |
| 114 | * space or user address space (see @userbuf) |
| 115 | * @csize: number of bytes to copy |
| 116 | * @offset: offset in bytes into the page (based on pfn) to begin the copy |
| 117 | * @userbuf: if set, @buf is in user address space, use copy_to_user(), |
| 118 | * otherwise @buf is in kernel address space, use memcpy(). |
| 119 | * |
| 120 | * Copy a page from "oldmem". For this page, there is no pte mapped |
| 121 | * in the current kernel. We stitch up a pte, similar to kmap_atomic. |
| 122 | */ |
| 123 | ssize_t copy_oldmem_page(unsigned long pfn, char *buf, |
| 124 | size_t csize, unsigned long offset, int userbuf) |
| 125 | { |
| 126 | void *vaddr; |
| 127 | |
| 128 | if (!csize) |
| 129 | return 0; |
| 130 | |
Michael Ellerman | 7230ced | 2008-07-31 16:54:28 +1000 | [diff] [blame] | 131 | csize = min(csize, PAGE_SIZE); |
Michael Ellerman | 54c3202 | 2005-12-04 18:39:51 +1100 | [diff] [blame] | 132 | |
Michael Ellerman | 7230ced | 2008-07-31 16:54:28 +1000 | [diff] [blame] | 133 | if (pfn < max_pfn) { |
| 134 | vaddr = __va(pfn << PAGE_SHIFT); |
| 135 | csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); |
| 136 | } else { |
| 137 | vaddr = __ioremap(pfn << PAGE_SHIFT, PAGE_SIZE, 0); |
| 138 | csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); |
| 139 | iounmap(vaddr); |
| 140 | } |
Michael Ellerman | 54c3202 | 2005-12-04 18:39:51 +1100 | [diff] [blame] | 141 | |
Michael Ellerman | 54c3202 | 2005-12-04 18:39:51 +1100 | [diff] [blame] | 142 | return csize; |
| 143 | } |