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 #include <asm/pgtable.h> /* for pgprot_t */ 10 11 #define ELFCORE_ADDR_MAX (-1ULL) 12 #define ELFCORE_ADDR_ERR (-2ULL) 13 14 extern unsigned long long elfcorehdr_addr; 15 extern unsigned long long elfcorehdr_size; 16 17 extern int __weak elfcorehdr_alloc(unsigned long long *addr, 18 unsigned long long *size); 19 extern void __weak elfcorehdr_free(unsigned long long addr); 20 extern ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos); 21 extern ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos); 22 extern int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma, 23 unsigned long from, unsigned long pfn, 24 unsigned long size, pgprot_t prot); 25 26 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, 27 unsigned long, int); 28 void vmcore_cleanup(void); 29 30 /* Architecture code defines this if there are other possible ELF 31 * machine types, e.g. on bi-arch capable hardware. */ 32 #ifndef vmcore_elf_check_arch_cross 33 #define vmcore_elf_check_arch_cross(x) 0 34 #endif 35 36 /* 37 * Architecture code can redefine this if there are any special checks 38 * needed for 64-bit ELF vmcores. In case of 32-bit only architecture, 39 * this can be set to zero. 40 */ 41 #ifndef vmcore_elf64_check_arch 42 #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) 43 #endif 44 45 /* 46 * is_kdump_kernel() checks whether this kernel is booting after a panic of 47 * previous kernel or not. This is determined by checking if previous kernel 48 * has passed the elf core header address on command line. 49 * 50 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will 51 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of 52 * previous kernel. 53 */ 54 55 static inline int is_kdump_kernel(void) 56 { 57 return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0; 58 } 59 60 /* is_vmcore_usable() checks if the kernel is booting after a panic and 61 * the vmcore region is usable. 62 * 63 * This makes use of the fact that due to alignment -2ULL is not 64 * a valid pointer, much in the vain of IS_ERR(), except 65 * dealing directly with an unsigned long long rather than a pointer. 66 */ 67 68 static inline int is_vmcore_usable(void) 69 { 70 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; 71 } 72 73 /* vmcore_unusable() marks the vmcore as unusable, 74 * without disturbing the logic of is_kdump_kernel() 75 */ 76 77 static inline void vmcore_unusable(void) 78 { 79 if (is_kdump_kernel()) 80 elfcorehdr_addr = ELFCORE_ADDR_ERR; 81 } 82 83 #define HAVE_OLDMEM_PFN_IS_RAM 1 84 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)); 85 extern void unregister_oldmem_pfn_is_ram(void); 86 87 #else /* !CONFIG_CRASH_DUMP */ 88 static inline int is_kdump_kernel(void) { return 0; } 89 #endif /* CONFIG_CRASH_DUMP */ 90 91 extern unsigned long saved_max_pfn; 92 #endif /* LINUX_CRASHDUMP_H */ 93