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