include/linux/kexec.h

#ifndef LINUX_KEXEC_H
#define LINUX_KEXEC_H

#ifdef CONFIG_KEXEC
#include <linux/types.h>
#include <linux/list.h>
#include <linux/linkage.h>
#include <linux/compat.h>
#include <asm/kexec.h>

/* Verify architecture specific macros are defined */

#ifndef KEXEC_SOURCE_MEMORY_LIMIT
#error KEXEC_SOURCE_MEMORY_LIMIT not defined
#endif

#ifndef KEXEC_DESTINATION_MEMORY_LIMIT
#error KEXEC_DESTINATION_MEMORY_LIMIT not defined
#endif

#ifndef KEXEC_CONTROL_MEMORY_LIMIT
#error KEXEC_CONTROL_MEMORY_LIMIT not defined
#endif

#ifndef KEXEC_CONTROL_CODE_SIZE
#error KEXEC_CONTROL_CODE_SIZE not defined
#endif

#ifndef KEXEC_ARCH
#error KEXEC_ARCH not defined
#endif

/*
 * This structure is used to hold the arguments that are used when loading
 * kernel binaries.
 */

typedef unsigned long kimage_entry_t;
#define IND_DESTINATION  0x1
#define IND_INDIRECTION  0x2
#define IND_DONE         0x4
#define IND_SOURCE       0x8

#define KEXEC_SEGMENT_MAX 16
struct kexec_segment {
	void __user *buf;
	size_t bufsz;
	unsigned long mem;	/* User space sees this as a (void *) ... */
	size_t memsz;
};

#ifdef CONFIG_COMPAT
struct compat_kexec_segment {
	compat_uptr_t buf;
	compat_size_t bufsz;
	compat_ulong_t mem;	/* User space sees this as a (void *) ... */
	compat_size_t memsz;
};
#endif

struct kimage {
	kimage_entry_t head;
	kimage_entry_t *entry;
	kimage_entry_t *last_entry;

	unsigned long destination;

	unsigned long start;
	struct page *control_code_page;

	unsigned long nr_segments;
	struct kexec_segment segment[KEXEC_SEGMENT_MAX];

	struct list_head control_pages;
	struct list_head dest_pages;
	struct list_head unuseable_pages;

	/* Address of next control page to allocate for crash kernels. */
	unsigned long control_page;

	/* Flags to indicate special processing */
	unsigned int type : 1;
#define KEXEC_TYPE_DEFAULT 0
#define KEXEC_TYPE_CRASH   1
};



/* kexec interface functions */
extern NORET_TYPE void machine_kexec(struct kimage *image) ATTRIB_NORET;
extern int machine_kexec_prepare(struct kimage *image);
extern void machine_kexec_cleanup(struct kimage *image);
extern asmlinkage long sys_kexec_load(unsigned long entry,
					unsigned long nr_segments,
					struct kexec_segment __user *segments,
					unsigned long flags);
#ifdef CONFIG_COMPAT
extern asmlinkage long compat_sys_kexec_load(unsigned long entry,
				unsigned long nr_segments,
				struct compat_kexec_segment __user *segments,
				unsigned long flags);
#endif
extern struct page *kimage_alloc_control_pages(struct kimage *image,
						unsigned int order);
extern void crash_kexec(struct pt_regs *);
int kexec_should_crash(struct task_struct *);
extern struct kimage *kexec_image;

#define KEXEC_ON_CRASH  0x00000001
#define KEXEC_ARCH_MASK 0xffff0000

/* These values match the ELF architecture values.
 * Unless there is a good reason that should continue to be the case.
 */
#define KEXEC_ARCH_DEFAULT ( 0 << 16)
#define KEXEC_ARCH_386     ( 3 << 16)
#define KEXEC_ARCH_X86_64  (62 << 16)
#define KEXEC_ARCH_PPC     (20 << 16)
#define KEXEC_ARCH_PPC64   (21 << 16)
#define KEXEC_ARCH_IA_64   (50 << 16)
#define KEXEC_ARCH_S390    (22 << 16)

#define KEXEC_FLAGS    (KEXEC_ON_CRASH)  /* List of defined/legal kexec flags */

/* Location of a reserved region to hold the crash kernel.
 */
extern struct resource crashk_res;
typedef u32 note_buf_t[MAX_NOTE_BYTES/4];
extern note_buf_t *crash_notes;

#else /* !CONFIG_KEXEC */
struct pt_regs;
struct task_struct;
static inline void crash_kexec(struct pt_regs *regs) { }
static inline int kexec_should_crash(struct task_struct *p) { return 0; }
#endif /* CONFIG_KEXEC */
#endif /* LINUX_KEXEC_H */