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
16 extern unsigned long long elfcorehdr_addr;
17 extern unsigned long long elfcorehdr_size;
18
19 extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
20 extern void elfcorehdr_free(unsigned long long addr);
21 extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
22 extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
23 extern 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
27 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
28 unsigned long, int);
29 void 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
is_kdump_kernel(void)60 static 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
is_vmcore_usable(void)73 static 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
vmcore_unusable(void)82 static 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
89 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
90 extern void unregister_oldmem_pfn_is_ram(void);
91
92 #else /* !CONFIG_CRASH_DUMP */
is_kdump_kernel(void)93 static inline bool is_kdump_kernel(void) { return 0; }
94 #endif /* CONFIG_CRASH_DUMP */
95
96 extern unsigned long saved_max_pfn;
97
98 /* Device Dump information to be filled by drivers */
99 struct 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
107 int vmcore_add_device_dump(struct vmcoredd_data *data);
108 #else
vmcore_add_device_dump(struct vmcoredd_data * data)109 static 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