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 int __weak elfcorehdr_alloc(unsigned long long *addr, 16 unsigned long long *size); 17 extern void __weak elfcorehdr_free(unsigned long long addr); 18 extern ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos); 19 extern ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos); 20 21 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, 22 unsigned long, int); 23 24 /* Architecture code defines this if there are other possible ELF 25 * machine types, e.g. on bi-arch capable hardware. */ 26 #ifndef vmcore_elf_check_arch_cross 27 #define vmcore_elf_check_arch_cross(x) 0 28 #endif 29 30 /* 31 * Architecture code can redefine this if there are any special checks 32 * needed for 64-bit ELF vmcores. In case of 32-bit only architecture, 33 * this can be set to zero. 34 */ 35 #ifndef vmcore_elf64_check_arch 36 #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) 37 #endif 38 39 /* 40 * is_kdump_kernel() checks whether this kernel is booting after a panic of 41 * previous kernel or not. This is determined by checking if previous kernel 42 * has passed the elf core header address on command line. 43 * 44 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will 45 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of 46 * previous kernel. 47 */ 48 49 static inline int is_kdump_kernel(void) 50 { 51 return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0; 52 } 53 54 /* is_vmcore_usable() checks if the kernel is booting after a panic and 55 * the vmcore region is usable. 56 * 57 * This makes use of the fact that due to alignment -2ULL is not 58 * a valid pointer, much in the vain of IS_ERR(), except 59 * dealing directly with an unsigned long long rather than a pointer. 60 */ 61 62 static inline int is_vmcore_usable(void) 63 { 64 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; 65 } 66 67 /* vmcore_unusable() marks the vmcore as unusable, 68 * without disturbing the logic of is_kdump_kernel() 69 */ 70 71 static inline void vmcore_unusable(void) 72 { 73 if (is_kdump_kernel()) 74 elfcorehdr_addr = ELFCORE_ADDR_ERR; 75 } 76 77 #define HAVE_OLDMEM_PFN_IS_RAM 1 78 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)); 79 extern void unregister_oldmem_pfn_is_ram(void); 80 81 #else /* !CONFIG_CRASH_DUMP */ 82 static inline int is_kdump_kernel(void) { return 0; } 83 #endif /* CONFIG_CRASH_DUMP */ 84 85 extern unsigned long saved_max_pfn; 86 #endif /* LINUX_CRASHDUMP_H */ 87