1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef LINUX_CRASH_DUMP_H 3 #define LINUX_CRASH_DUMP_H 4 5 #ifdef CONFIG_CRASH_DUMP 6 #include <linux/kexec.h> 7 #include <linux/proc_fs.h> 8 #include <linux/elf.h> 9 10 #include <asm/pgtable.h> /* for pgprot_t */ 11 12 #define ELFCORE_ADDR_MAX (-1ULL) 13 #define ELFCORE_ADDR_ERR (-2ULL) 14 15 extern unsigned long long elfcorehdr_addr; 16 extern unsigned long long elfcorehdr_size; 17 18 extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size); 19 extern void elfcorehdr_free(unsigned long long addr); 20 extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos); 21 extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos); 22 extern int 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 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit 39 * only architecture, vmcore_elf64_check_arch can be set to zero. 40 */ 41 #ifndef vmcore_elf32_check_arch 42 #define vmcore_elf32_check_arch(x) elf_check_arch(x) 43 #endif 44 45 #ifndef vmcore_elf64_check_arch 46 #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) 47 #endif 48 49 /* 50 * is_kdump_kernel() checks whether this kernel is booting after a panic of 51 * previous kernel or not. This is determined by checking if previous kernel 52 * has passed the elf core header address on command line. 53 * 54 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will 55 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of 56 * previous kernel. 57 */ 58 59 static inline int is_kdump_kernel(void) 60 { 61 return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0; 62 } 63 64 /* is_vmcore_usable() checks if the kernel is booting after a panic and 65 * the vmcore region is usable. 66 * 67 * This makes use of the fact that due to alignment -2ULL is not 68 * a valid pointer, much in the vain of IS_ERR(), except 69 * dealing directly with an unsigned long long rather than a pointer. 70 */ 71 72 static inline int is_vmcore_usable(void) 73 { 74 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; 75 } 76 77 /* vmcore_unusable() marks the vmcore as unusable, 78 * without disturbing the logic of is_kdump_kernel() 79 */ 80 81 static inline void vmcore_unusable(void) 82 { 83 if (is_kdump_kernel()) 84 elfcorehdr_addr = ELFCORE_ADDR_ERR; 85 } 86 87 #define HAVE_OLDMEM_PFN_IS_RAM 1 88 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)); 89 extern void unregister_oldmem_pfn_is_ram(void); 90 91 #else /* !CONFIG_CRASH_DUMP */ 92 static inline int is_kdump_kernel(void) { return 0; } 93 #endif /* CONFIG_CRASH_DUMP */ 94 95 extern unsigned long saved_max_pfn; 96 #endif /* LINUX_CRASHDUMP_H */ 97