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
14extern unsigned long long elfcorehdr_addr;
15extern unsigned long long elfcorehdr_size;
16
17extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
18extern void elfcorehdr_free(unsigned long long addr);
19extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
20extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
21extern 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
25extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
26						unsigned long, int);
27void 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 64-bit ELF vmcores. In case of 32-bit only architecture,
38 * this can be set to zero.
39 */
40#ifndef vmcore_elf64_check_arch
41#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
42#endif
43
44/*
45 * is_kdump_kernel() checks whether this kernel is booting after a panic of
46 * previous kernel or not. This is determined by checking if previous kernel
47 * has passed the elf core header address on command line.
48 *
49 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
50 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of
51 * previous kernel.
52 */
53
54static inline int is_kdump_kernel(void)
55{
56	return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0;
57}
58
59/* is_vmcore_usable() checks if the kernel is booting after a panic and
60 * the vmcore region is usable.
61 *
62 * This makes use of the fact that due to alignment -2ULL is not
63 * a valid pointer, much in the vain of IS_ERR(), except
64 * dealing directly with an unsigned long long rather than a pointer.
65 */
66
67static inline int is_vmcore_usable(void)
68{
69	return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
70}
71
72/* vmcore_unusable() marks the vmcore as unusable,
73 * without disturbing the logic of is_kdump_kernel()
74 */
75
76static inline void vmcore_unusable(void)
77{
78	if (is_kdump_kernel())
79		elfcorehdr_addr = ELFCORE_ADDR_ERR;
80}
81
82#define HAVE_OLDMEM_PFN_IS_RAM 1
83extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
84extern void unregister_oldmem_pfn_is_ram(void);
85
86#else /* !CONFIG_CRASH_DUMP */
87static inline int is_kdump_kernel(void) { return 0; }
88#endif /* CONFIG_CRASH_DUMP */
89
90extern unsigned long saved_max_pfn;
91#endif /* LINUX_CRASHDUMP_H */
92