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/proc_fs.h> 7 #include <linux/elf.h> 8 9 #define ELFCORE_ADDR_MAX (-1ULL) 10 #define ELFCORE_ADDR_ERR (-2ULL) 11 12 extern unsigned long long elfcorehdr_addr; 13 extern unsigned long long elfcorehdr_size; 14 15 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, 16 unsigned long, int); 17 18 /* Architecture code defines this if there are other possible ELF 19 * machine types, e.g. on bi-arch capable hardware. */ 20 #ifndef vmcore_elf_check_arch_cross 21 #define vmcore_elf_check_arch_cross(x) 0 22 #endif 23 24 /* 25 * Architecture code can redefine this if there are any special checks 26 * needed for 64-bit ELF vmcores. In case of 32-bit only architecture, 27 * this can be set to zero. 28 */ 29 #ifndef vmcore_elf64_check_arch 30 #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) 31 #endif 32 33 /* 34 * is_kdump_kernel() checks whether this kernel is booting after a panic of 35 * previous kernel or not. This is determined by checking if previous kernel 36 * has passed the elf core header address on command line. 37 * 38 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will 39 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of 40 * previous kernel. 41 */ 42 is_kdump_kernel(void)43static inline int is_kdump_kernel(void) 44 { 45 return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0; 46 } 47 48 /* is_vmcore_usable() checks if the kernel is booting after a panic and 49 * the vmcore region is usable. 50 * 51 * This makes use of the fact that due to alignment -2ULL is not 52 * a valid pointer, much in the vain of IS_ERR(), except 53 * dealing directly with an unsigned long long rather than a pointer. 54 */ 55 is_vmcore_usable(void)56static inline int is_vmcore_usable(void) 57 { 58 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; 59 } 60 61 /* vmcore_unusable() marks the vmcore as unusable, 62 * without disturbing the logic of is_kdump_kernel() 63 */ 64 vmcore_unusable(void)65static inline void vmcore_unusable(void) 66 { 67 if (is_kdump_kernel()) 68 elfcorehdr_addr = ELFCORE_ADDR_ERR; 69 } 70 71 #define HAVE_OLDMEM_PFN_IS_RAM 1 72 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)); 73 extern void unregister_oldmem_pfn_is_ram(void); 74 75 #else /* !CONFIG_CRASH_DUMP */ is_kdump_kernel(void)76static inline int is_kdump_kernel(void) { return 0; } 77 #endif /* CONFIG_CRASH_DUMP */ 78 79 extern unsigned long saved_max_pfn; 80 #endif /* LINUX_CRASHDUMP_H */ 81