1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef LINUX_CRASH_DUMP_H
3#define LINUX_CRASH_DUMP_H
4
5#include <linux/kexec.h>
6#include <linux/proc_fs.h>
7#include <linux/elf.h>
8#include <uapi/linux/vmcore.h>
9
10#include <asm/pgtable.h> /* for pgprot_t */
11
12#ifdef CONFIG_CRASH_DUMP
13#define ELFCORE_ADDR_MAX (-1ULL)
14#define ELFCORE_ADDR_ERR (-2ULL)
15
16extern unsigned long long elfcorehdr_addr;
17extern unsigned long long elfcorehdr_size;
18
19extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
20extern void elfcorehdr_free(unsigned long long addr);
21extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
22extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
23extern int remap_oldmem_pfn_range(struct vm_area_struct *vma,
24 unsigned long from, unsigned long pfn,
25 unsigned long size, pgprot_t prot);
26
27extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
28 unsigned long, int);
29void vmcore_cleanup(void);
30
31/* Architecture code defines this if there are other possible ELF
32 * machine types, e.g. on bi-arch capable hardware. */
33#ifndef vmcore_elf_check_arch_cross
34#define vmcore_elf_check_arch_cross(x) 0
35#endif
36
37/*
38 * Architecture code can redefine this if there are any special checks
39 * needed for 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit
40 * only architecture, vmcore_elf64_check_arch can be set to zero.
41 */
42#ifndef vmcore_elf32_check_arch
43#define vmcore_elf32_check_arch(x) elf_check_arch(x)
44#endif
45
46#ifndef vmcore_elf64_check_arch
47#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
48#endif
49
50/*
51 * is_kdump_kernel() checks whether this kernel is booting after a panic of
52 * previous kernel or not. This is determined by checking if previous kernel
53 * has passed the elf core header address on command line.
54 *
55 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
56 * return true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic
57 * of previous kernel.
58 */
59
60static inline bool is_kdump_kernel(void)
61{
62 return elfcorehdr_addr != ELFCORE_ADDR_MAX;
63}
64
65/* is_vmcore_usable() checks if the kernel is booting after a panic and
66 * the vmcore region is usable.
67 *
68 * This makes use of the fact that due to alignment -2ULL is not
69 * a valid pointer, much in the vain of IS_ERR(), except
70 * dealing directly with an unsigned long long rather than a pointer.
71 */
72
73static inline int is_vmcore_usable(void)
74{
75 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
76}
77
78/* vmcore_unusable() marks the vmcore as unusable,
79 * without disturbing the logic of is_kdump_kernel()
80 */
81
82static inline void vmcore_unusable(void)
83{
84 if (is_kdump_kernel())
85 elfcorehdr_addr = ELFCORE_ADDR_ERR;
86}
87
88#define HAVE_OLDMEM_PFN_IS_RAM 1
89extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
90extern void unregister_oldmem_pfn_is_ram(void);
91
92#else /* !CONFIG_CRASH_DUMP */
93static inline bool is_kdump_kernel(void) { return 0; }
94#endif /* CONFIG_CRASH_DUMP */
95
96extern unsigned long saved_max_pfn;
97
98/* Device Dump information to be filled by drivers */
99struct vmcoredd_data {
100 char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */
101 unsigned int size; /* Size of the dump */
102 /* Driver's registered callback to be invoked to collect dump */
103 int (*vmcoredd_callback)(struct vmcoredd_data *data, void *buf);
104};
105
106#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
107int vmcore_add_device_dump(struct vmcoredd_data *data);
108#else
109static inline int vmcore_add_device_dump(struct vmcoredd_data *data)
110{
111 return -EOPNOTSUPP;
112}
113#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
114#endif /* LINUX_CRASHDUMP_H */
115