sysfs: Remove support for tagged directories with untagged members (again)
[linux-btrfs-devel.git] / include / linux / crash_dump.h
blob74054074e876d8da1ae9de24dc8ae64f856391c7
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/device.h>
7 #include <linux/proc_fs.h>
9 #define ELFCORE_ADDR_MAX (-1ULL)
10 #define ELFCORE_ADDR_ERR (-2ULL)
12 extern unsigned long long elfcorehdr_addr;
14 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
15 unsigned long, int);
17 /* Architecture code defines this if there are other possible ELF
18 * machine types, e.g. on bi-arch capable hardware. */
19 #ifndef vmcore_elf_check_arch_cross
20 #define vmcore_elf_check_arch_cross(x) 0
21 #endif
24 * Architecture code can redefine this if there are any special checks
25 * needed for 64-bit ELF vmcores. In case of 32-bit only architecture,
26 * this can be set to zero.
28 #ifndef vmcore_elf64_check_arch
29 #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
30 #endif
33 * is_kdump_kernel() checks whether this kernel is booting after a panic of
34 * previous kernel or not. This is determined by checking if previous kernel
35 * has passed the elf core header address on command line.
37 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
38 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of
39 * previous kernel.
42 static inline int is_kdump_kernel(void)
44 return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0;
47 /* is_vmcore_usable() checks if the kernel is booting after a panic and
48 * the vmcore region is usable.
50 * This makes use of the fact that due to alignment -2ULL is not
51 * a valid pointer, much in the vain of IS_ERR(), except
52 * dealing directly with an unsigned long long rather than a pointer.
55 static inline int is_vmcore_usable(void)
57 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
60 /* vmcore_unusable() marks the vmcore as unusable,
61 * without disturbing the logic of is_kdump_kernel()
64 static inline void vmcore_unusable(void)
66 if (is_kdump_kernel())
67 elfcorehdr_addr = ELFCORE_ADDR_ERR;
70 #define HAVE_OLDMEM_PFN_IS_RAM 1
71 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
72 extern void unregister_oldmem_pfn_is_ram(void);
74 #else /* !CONFIG_CRASH_DUMP */
75 static inline int is_kdump_kernel(void) { return 0; }
76 #endif /* CONFIG_CRASH_DUMP */
78 extern unsigned long saved_max_pfn;
79 #endif /* LINUX_CRASHDUMP_H */