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 extern int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma, 21 unsigned long from, unsigned long pfn, 22 unsigned long size, pgprot_t prot); 23 24 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, 25 unsigned long, int); 26 27 /* Architecture code defines this if there are other possible ELF 28 * machine types, e.g. on bi-arch capable hardware. */ 29 #ifndef vmcore_elf_check_arch_cross 30 #define vmcore_elf_check_arch_cross(x) 0 31 #endif 32 33 /* 34 * Architecture code can redefine this if there are any special checks 35 * needed for 64-bit ELF vmcores. In case of 32-bit only architecture, 36 * this can be set to zero. 37 */ 38 #ifndef vmcore_elf64_check_arch 39 #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) 40 #endif 41 42 /* 43 * is_kdump_kernel() checks whether this kernel is booting after a panic of 44 * previous kernel or not. This is determined by checking if previous kernel 45 * has passed the elf core header address on command line. 46 * 47 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will 48 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of 49 * previous kernel. 50 */ 51 52 static inline int is_kdump_kernel(void) 53 { 54 return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0; 55 } 56 57 /* is_vmcore_usable() checks if the kernel is booting after a panic and 58 * the vmcore region is usable. 59 * 60 * This makes use of the fact that due to alignment -2ULL is not 61 * a valid pointer, much in the vain of IS_ERR(), except 62 * dealing directly with an unsigned long long rather than a pointer. 63 */ 64 65 static inline int is_vmcore_usable(void) 66 { 67 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; 68 } 69 70 /* vmcore_unusable() marks the vmcore as unusable, 71 * without disturbing the logic of is_kdump_kernel() 72 */ 73 74 static inline void vmcore_unusable(void) 75 { 76 if (is_kdump_kernel()) 77 elfcorehdr_addr = ELFCORE_ADDR_ERR; 78 } 79 80 #define HAVE_OLDMEM_PFN_IS_RAM 1 81 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)); 82 extern void unregister_oldmem_pfn_is_ram(void); 83 84 #else /* !CONFIG_CRASH_DUMP */ 85 static inline int is_kdump_kernel(void) { return 0; } 86 #endif /* CONFIG_CRASH_DUMP */ 87 88 extern unsigned long saved_max_pfn; 89 #endif /* LINUX_CRASHDUMP_H */ 90