LXR linux/include/linux/crash

   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
  14extern unsigned long long elfcorehdr_addr;
  15extern unsigned long long elfcorehdr_size;
  16
  17extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
  18extern void elfcorehdr_free(unsigned long long addr);
  19extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
  20extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
  21extern 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
  25extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
  26                                                unsigned long, int);
  27void 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
  54static 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
  67static 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
  76static 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
  83extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
  84extern void unregister_oldmem_pfn_is_ram(void);
  85
  86#else /* !CONFIG_CRASH_DUMP */
  87static inline int is_kdump_kernel(void) { return 0; }
  88#endif /* CONFIG_CRASH_DUMP */
  89
  90extern unsigned long saved_max_pfn;
  91#endif /* LINUX_CRASHDUMP_H */
  92