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 32-bit ELF or 64-bit ELF vmcores.  In case of 32-bit
  38 * only architecture, vmcore_elf64_check_arch can be set to zero.
  39 */
  40#ifndef vmcore_elf32_check_arch
  41#define vmcore_elf32_check_arch(x) elf_check_arch(x)
  42#endif
  43
  44#ifndef vmcore_elf64_check_arch
  45#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
  46#endif
  47
  48/*
  49 * is_kdump_kernel() checks whether this kernel is booting after a panic of
  50 * previous kernel or not. This is determined by checking if previous kernel
  51 * has passed the elf core header address on command line.
  52 *
  53 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
  54 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of
  55 * previous kernel.
  56 */
  57
  58static inline int is_kdump_kernel(void)
  59{
  60        return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0;
  61}
  62
  63/* is_vmcore_usable() checks if the kernel is booting after a panic and
  64 * the vmcore region is usable.
  65 *
  66 * This makes use of the fact that due to alignment -2ULL is not
  67 * a valid pointer, much in the vain of IS_ERR(), except
  68 * dealing directly with an unsigned long long rather than a pointer.
  69 */
  70
  71static inline int is_vmcore_usable(void)
  72{
  73        return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
  74}
  75
  76/* vmcore_unusable() marks the vmcore as unusable,
  77 * without disturbing the logic of is_kdump_kernel()
  78 */
  79
  80static inline void vmcore_unusable(void)
  81{
  82        if (is_kdump_kernel())
  83                elfcorehdr_addr = ELFCORE_ADDR_ERR;
  84}
  85
  86#define HAVE_OLDMEM_PFN_IS_RAM 1
  87extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
  88extern void unregister_oldmem_pfn_is_ram(void);
  89
  90#else /* !CONFIG_CRASH_DUMP */
  91static inline int is_kdump_kernel(void) { return 0; }
  92#endif /* CONFIG_CRASH_DUMP */
  93
  94extern unsigned long saved_max_pfn;
  95#endif /* LINUX_CRASHDUMP_H */
  96