Commit | Line | Data |
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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 | 14 | #include <linux/crash_dump.h> |
edcee77f | 15 | #include <linux/io.h> |
95f72d1e | 16 | #include <linux/memblock.h> |
aaddd3ea | 17 | #include <asm/code-patching.h> |
0cc4746c | 18 | #include <asm/kdump.h> |
d9b2b2a2 | 19 | #include <asm/prom.h> |
0cc4746c | 20 | #include <asm/firmware.h> |
54c32021 | 21 | #include <asm/uaccess.h> |
d72e063b | 22 | #include <asm/rtas.h> |
0cc4746c ME |
23 | |
24 | #ifdef DEBUG | |
25 | #include <asm/udbg.h> | |
26 | #define DBG(fmt...) udbg_printf(fmt) | |
27 | #else | |
28 | #define DBG(fmt...) | |
29 | #endif | |
30 | ||
0f890c8d | 31 | #ifndef CONFIG_NONSTATIC_KERNEL |
d56c3aaa | 32 | void __init reserve_kdump_trampoline(void) |
47310413 | 33 | { |
95f72d1e | 34 | memblock_reserve(0, KDUMP_RESERVE_LIMIT); |
47310413 ME |
35 | } |
36 | ||
0cc4746c ME |
37 | static void __init create_trampoline(unsigned long addr) |
38 | { | |
e7a57273 ME |
39 | unsigned int *p = (unsigned int *)addr; |
40 | ||
0cc4746c ME |
41 | /* The maximum range of a single instruction branch, is the current |
42 | * instruction's address + (32 MB - 4) bytes. For the trampoline we | |
43 | * need to branch to current address + 32 MB. So we insert a nop at | |
44 | * the trampoline address, then the next instruction (+ 4 bytes) | |
45 | * does a branch to (32 MB - 4). The net effect is that when we | |
46 | * branch to "addr" we jump to ("addr" + 32 MB). Although it requires | |
47 | * two instructions it doesn't require any registers. | |
48 | */ | |
16c57b36 | 49 | patch_instruction(p, PPC_INST_NOP); |
e7a57273 | 50 | patch_branch(++p, addr + PHYSICAL_START, 0); |
0cc4746c ME |
51 | } |
52 | ||
47310413 | 53 | void __init setup_kdump_trampoline(void) |
0cc4746c ME |
54 | { |
55 | unsigned long i; | |
56 | ||
47310413 | 57 | DBG(" -> setup_kdump_trampoline()\n"); |
0cc4746c ME |
58 | |
59 | for (i = KDUMP_TRAMPOLINE_START; i < KDUMP_TRAMPOLINE_END; i += 8) { | |
60 | create_trampoline(i); | |
61 | } | |
62 | ||
9e4859ef | 63 | #ifdef CONFIG_PPC_PSERIES |
0cc4746c ME |
64 | create_trampoline(__pa(system_reset_fwnmi) - PHYSICAL_START); |
65 | create_trampoline(__pa(machine_check_fwnmi) - PHYSICAL_START); | |
9e4859ef | 66 | #endif /* CONFIG_PPC_PSERIES */ |
0cc4746c | 67 | |
47310413 | 68 | DBG(" <- setup_kdump_trampoline()\n"); |
0cc4746c | 69 | } |
0f890c8d | 70 | #endif /* CONFIG_NONSTATIC_KERNEL */ |
cc532915 | 71 | |
7230ced4 ME |
72 | static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize, |
73 | unsigned long offset, int userbuf) | |
74 | { | |
75 | if (userbuf) { | |
76 | if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) | |
77 | return -EFAULT; | |
78 | } else | |
79 | memcpy(buf, (vaddr + offset), csize); | |
80 | ||
81 | return csize; | |
82 | } | |
83 | ||
40681b95 | 84 | /** |
54c32021 ME |
85 | * copy_oldmem_page - copy one page from "oldmem" |
86 | * @pfn: page frame number to be copied | |
87 | * @buf: target memory address for the copy; this can be in kernel address | |
88 | * space or user address space (see @userbuf) | |
89 | * @csize: number of bytes to copy | |
90 | * @offset: offset in bytes into the page (based on pfn) to begin the copy | |
91 | * @userbuf: if set, @buf is in user address space, use copy_to_user(), | |
92 | * otherwise @buf is in kernel address space, use memcpy(). | |
93 | * | |
94 | * Copy a page from "oldmem". For this page, there is no pte mapped | |
95 | * in the current kernel. We stitch up a pte, similar to kmap_atomic. | |
96 | */ | |
97 | ssize_t copy_oldmem_page(unsigned long pfn, char *buf, | |
98 | size_t csize, unsigned long offset, int userbuf) | |
99 | { | |
100 | void *vaddr; | |
f5295bd8 | 101 | phys_addr_t paddr; |
54c32021 ME |
102 | |
103 | if (!csize) | |
104 | return 0; | |
105 | ||
bbc8e30f | 106 | csize = min_t(size_t, csize, PAGE_SIZE); |
f5295bd8 | 107 | paddr = pfn << PAGE_SHIFT; |
54c32021 | 108 | |
f5295bd8 LD |
109 | if (memblock_is_region_memory(paddr, csize)) { |
110 | vaddr = __va(paddr); | |
7230ced4 ME |
111 | csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); |
112 | } else { | |
f5295bd8 | 113 | vaddr = __ioremap(paddr, PAGE_SIZE, 0); |
7230ced4 ME |
114 | csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); |
115 | iounmap(vaddr); | |
116 | } | |
54c32021 | 117 | |
54c32021 ME |
118 | return csize; |
119 | } | |
d72e063b AB |
120 | |
121 | #ifdef CONFIG_PPC_RTAS | |
122 | /* | |
123 | * The crashkernel region will almost always overlap the RTAS region, so | |
124 | * we have to be careful when shrinking the crashkernel region. | |
125 | */ | |
126 | void crash_free_reserved_phys_range(unsigned long begin, unsigned long end) | |
127 | { | |
128 | unsigned long addr; | |
a29e30ef | 129 | const __be32 *basep, *sizep; |
d72e063b AB |
130 | unsigned int rtas_start = 0, rtas_end = 0; |
131 | ||
132 | basep = of_get_property(rtas.dev, "linux,rtas-base", NULL); | |
133 | sizep = of_get_property(rtas.dev, "rtas-size", NULL); | |
134 | ||
135 | if (basep && sizep) { | |
a29e30ef AB |
136 | rtas_start = be32_to_cpup(basep); |
137 | rtas_end = rtas_start + be32_to_cpup(sizep); | |
d72e063b AB |
138 | } |
139 | ||
140 | for (addr = begin; addr < end; addr += PAGE_SIZE) { | |
141 | /* Does this page overlap with the RTAS region? */ | |
142 | if (addr <= rtas_end && ((addr + PAGE_SIZE) > rtas_start)) | |
143 | continue; | |
144 | ||
5d585e5c | 145 | free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT)); |
d72e063b AB |
146 | } |
147 | } | |
148 | #endif |