| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 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 elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size); |
| 18 | extern void elfcorehdr_free(unsigned long long addr); |
| 19 | extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos); |
| 20 | extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos); |
| 21 | extern int remap_oldmem_pfn_range(struct vm_area_struct *vma, |
| 22 | unsigned long from, unsigned long pfn, |
| 23 | unsigned long size, pgprot_t prot); |
| 24 | |
| 25 | extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, |
| 26 | unsigned long, int); |
| 27 | void vmcore_cleanup(void); |
| 28 | |
| 29 | /* Architecture code defines this if there are other possible ELF |
| 30 | * machine types, e.g. on bi-arch capable hardware. */ |
| 31 | #ifndef vmcore_elf_check_arch_cross |
| 32 | #define vmcore_elf_check_arch_cross(x) 0 |
| 33 | #endif |
| 34 | |
| 35 | /* |
| 36 | * Architecture code can redefine this if there are any special checks |
| 37 | * needed for 64-bit ELF vmcores. In case of 32-bit only architecture, |
| 38 | * this can be set to zero. |
| 39 | */ |
| 40 | #ifndef vmcore_elf64_check_arch |
| 41 | #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) |
| 42 | #endif |
| 43 | |
| 44 | /* |
| 45 | * is_kdump_kernel() checks whether this kernel is booting after a panic of |
| 46 | * previous kernel or not. This is determined by checking if previous kernel |
| 47 | * has passed the elf core header address on command line. |
| 48 | * |
| 49 | * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will |
| 50 | * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of |
| 51 | * previous kernel. |
| 52 | */ |
| 53 | |
| 54 | static inline int is_kdump_kernel(void) |
| 55 | { |
| 56 | return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0; |
| 57 | } |
| 58 | |
| 59 | /* is_vmcore_usable() checks if the kernel is booting after a panic and |
| 60 | * the vmcore region is usable. |
| 61 | * |
| 62 | * This makes use of the fact that due to alignment -2ULL is not |
| 63 | * a valid pointer, much in the vain of IS_ERR(), except |
| 64 | * dealing directly with an unsigned long long rather than a pointer. |
| 65 | */ |
| 66 | |
| 67 | static inline int is_vmcore_usable(void) |
| 68 | { |
| 69 | return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; |
| 70 | } |
| 71 | |
| 72 | /* vmcore_unusable() marks the vmcore as unusable, |
| 73 | * without disturbing the logic of is_kdump_kernel() |
| 74 | */ |
| 75 | |
| 76 | static inline void vmcore_unusable(void) |
| 77 | { |
| 78 | if (is_kdump_kernel()) |
| 79 | elfcorehdr_addr = ELFCORE_ADDR_ERR; |
| 80 | } |
| 81 | |
| 82 | #define HAVE_OLDMEM_PFN_IS_RAM 1 |
| 83 | extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)); |
| 84 | extern void unregister_oldmem_pfn_is_ram(void); |
| 85 | |
| 86 | #else /* !CONFIG_CRASH_DUMP */ |
| 87 | static inline int is_kdump_kernel(void) { return 0; } |
| 88 | #endif /* CONFIG_CRASH_DUMP */ |
| 89 | |
| 90 | extern unsigned long saved_max_pfn; |
| 91 | #endif /* LINUX_CRASHDUMP_H */ |