1#ifndef LINUX_CRASH_DUMP_H 2#define LINUX_CRASH_DUMP_H 3 4#ifdef CONFIG_CRASH_DUMP 5#include <linux/kexec.h> 6#include <linux/device.h> 7#include <linux/proc_fs.h> 8 9#define ELFCORE_ADDR_MAX (-1ULL) 10#define ELFCORE_ADDR_ERR (-2ULL) 11 12extern unsigned long long elfcorehdr_addr; 13 14extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, 15 unsigned long, int); 16 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 22 23#define vmcore_elf_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) 24 25/* 26 * is_kdump_kernel() checks whether this kernel is booting after a panic of 27 * previous kernel or not. This is determined by checking if previous kernel 28 * has passed the elf core header address on command line. 29 * 30 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will 31 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of 32 * previous kernel. 33 */ 34 35static inline int is_kdump_kernel(void) 36{ 37 return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0; 38} 39 40/* is_vmcore_usable() checks if the kernel is booting after a panic and 41 * the vmcore region is usable. 42 * 43 * This makes use of the fact that due to alignment -2ULL is not 44 * a valid pointer, much in the vain of IS_ERR(), except 45 * dealing directly with an unsigned long long rather than a pointer. 46 */ 47 48static inline int is_vmcore_usable(void) 49{ 50 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; 51} 52 53/* vmcore_unusable() marks the vmcore as unusable, 54 * without disturbing the logic of is_kdump_kernel() 55 */ 56 57static inline void vmcore_unusable(void) 58{ 59 if (is_kdump_kernel()) 60 elfcorehdr_addr = ELFCORE_ADDR_ERR; 61} 62#else /* !CONFIG_CRASH_DUMP */ 63static inline int is_kdump_kernel(void) { return 0; } 64#endif /* CONFIG_CRASH_DUMP */ 65 66extern unsigned long saved_max_pfn; 67#endif /* LINUX_CRASHDUMP_H */ 68