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);
29extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf,
30 size_t csize, unsigned long offset,
31 int userbuf);
32
33void vmcore_cleanup(void);
34
35/* Architecture code defines this if there are other possible ELF
36 * machine types, e.g. on bi-arch capable hardware. */
37#ifndef vmcore_elf_check_arch_cross
38#define vmcore_elf_check_arch_cross(x) 0
39#endif
40
41/*
42 * Architecture code can redefine this if there are any special checks
43 * needed for 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit
44 * only architecture, vmcore_elf64_check_arch can be set to zero.
45 */
46#ifndef vmcore_elf32_check_arch
47#define vmcore_elf32_check_arch(x) elf_check_arch(x)
48#endif
49
50#ifndef vmcore_elf64_check_arch
51#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
52#endif
53
54/*
55 * is_kdump_kernel() checks whether this kernel is booting after a panic of
56 * previous kernel or not. This is determined by checking if previous kernel
57 * has passed the elf core header address on command line.
58 *
59 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
60 * return true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic
61 * of previous kernel.
62 */
63
64static inline bool is_kdump_kernel(void)
65{
66 return elfcorehdr_addr != ELFCORE_ADDR_MAX;
67}
68
69/* is_vmcore_usable() checks if the kernel is booting after a panic and
70 * the vmcore region is usable.
71 *
72 * This makes use of the fact that due to alignment -2ULL is not
73 * a valid pointer, much in the vain of IS_ERR(), except
74 * dealing directly with an unsigned long long rather than a pointer.
75 */
76
77static inline int is_vmcore_usable(void)
78{
79 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
80}
81
82/* vmcore_unusable() marks the vmcore as unusable,
83 * without disturbing the logic of is_kdump_kernel()
84 */
85
86static inline void vmcore_unusable(void)
87{
88 if (is_kdump_kernel())
89 elfcorehdr_addr = ELFCORE_ADDR_ERR;
90}
91
92#define HAVE_OLDMEM_PFN_IS_RAM 1
93extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
94extern void unregister_oldmem_pfn_is_ram(void);
95
96#else /* !CONFIG_CRASH_DUMP */
97static inline bool is_kdump_kernel(void) { return 0; }
98#endif /* CONFIG_CRASH_DUMP */
99
100extern unsigned long saved_max_pfn;
101
102/* Device Dump information to be filled by drivers */
103struct vmcoredd_data {
104 char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */
105 unsigned int size; /* Size of the dump */
106 /* Driver's registered callback to be invoked to collect dump */
107 int (*vmcoredd_callback)(struct vmcoredd_data *data, void *buf);
108};
109
110#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
111int vmcore_add_device_dump(struct vmcoredd_data *data);
112#else
113static inline int vmcore_add_device_dump(struct vmcoredd_data *data)
114{
115 return -EOPNOTSUPP;
116}
117#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
118#endif /* LINUX_CRASHDUMP_H */
119