1 #ifndef LINUX_CRASH_DUMP_H
2 #define LINUX_CRASH_DUMP_H
3
4 #ifdef CONFIG_CRASH_DUMP
5 #include <linux/kexec.h>
6 #include <linux/proc_fs.h>
7 #include <linux/elf.h>
8
9 #include <asm/pgtable.h> /* for pgprot_t */
10
11 #define ELFCORE_ADDR_MAX (-1ULL)
12 #define ELFCORE_ADDR_ERR (-2ULL)
13
14 extern unsigned long long elfcorehdr_addr;
15 extern unsigned long long elfcorehdr_size;
16
17 extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
18 extern void elfcorehdr_free(unsigned long long addr);
19 extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
20 extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
21 extern int remap_oldmem_pfn_range(struct vm_area_struct *vma,
22 unsigned long from, unsigned long pfn,
23 unsigned long size, pgprot_t prot);
24
25 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
26 unsigned long, int);
27 void vmcore_cleanup(void);
28
29 /* Architecture code defines this if there are other possible ELF
30 * machine types, e.g. on bi-arch capable hardware. */
31 #ifndef vmcore_elf_check_arch_cross
32 #define vmcore_elf_check_arch_cross(x) 0
33 #endif
34
35 /*
36 * Architecture code can redefine this if there are any special checks
37 * needed for 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit
38 * only architecture, vmcore_elf64_check_arch can be set to zero.
39 */
40 #ifndef vmcore_elf32_check_arch
41 #define vmcore_elf32_check_arch(x) elf_check_arch(x)
42 #endif
43
44 #ifndef vmcore_elf64_check_arch
45 #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
46 #endif
47
48 /*
49 * is_kdump_kernel() checks whether this kernel is booting after a panic of
50 * previous kernel or not. This is determined by checking if previous kernel
51 * has passed the elf core header address on command line.
52 *
53 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
54 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of
55 * previous kernel.
56 */
57
is_kdump_kernel(void)58 static inline int is_kdump_kernel(void)
59 {
60 return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0;
61 }
62
63 /* is_vmcore_usable() checks if the kernel is booting after a panic and
64 * the vmcore region is usable.
65 *
66 * This makes use of the fact that due to alignment -2ULL is not
67 * a valid pointer, much in the vain of IS_ERR(), except
68 * dealing directly with an unsigned long long rather than a pointer.
69 */
70
is_vmcore_usable(void)71 static inline int is_vmcore_usable(void)
72 {
73 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
74 }
75
76 /* vmcore_unusable() marks the vmcore as unusable,
77 * without disturbing the logic of is_kdump_kernel()
78 */
79
vmcore_unusable(void)80 static inline void vmcore_unusable(void)
81 {
82 if (is_kdump_kernel())
83 elfcorehdr_addr = ELFCORE_ADDR_ERR;
84 }
85
86 #define HAVE_OLDMEM_PFN_IS_RAM 1
87 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
88 extern void unregister_oldmem_pfn_is_ram(void);
89
90 #else /* !CONFIG_CRASH_DUMP */
is_kdump_kernel(void)91 static inline int is_kdump_kernel(void) { return 0; }
92 #endif /* CONFIG_CRASH_DUMP */
93
94 extern unsigned long saved_max_pfn;
95 #endif /* LINUX_CRASHDUMP_H */
96