/*
 * swsusp.h
 *
 * Common definitions for user space suspend and resume handlers.
 *
 * Copyright (C) 2005 Rafael J. Wysocki <rjw@sisk.pl>
 *
 * This file is released under the GPLv2.
 *
 */

#define PAGE_SIZE	4096

#define SNAPSHOT_IOC_MAGIC	'3'
#define SNAPSHOT_IOCFREEZE		_IO(SNAPSHOT_IOC_MAGIC, 1)
#define SNAPSHOT_IOCUNFREEZE		_IO(SNAPSHOT_IOC_MAGIC, 2)
#define SNAPSHOT_IOCATOMIC_SNAPSHOT	_IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
#define SNAPSHOT_IOCATOMIC_RESTORE	_IO(SNAPSHOT_IOC_MAGIC, 4)
#define SNAPSHOT_IOCSET_IMAGE_SIZE	_IOW(SNAPSHOT_IOC_MAGIC, 5, unsigned long)
#define SNAPSHOT_IOCAVAIL_SWAP		_IOR(SNAPSHOT_IOC_MAGIC, 6, void *)
#define SNAPSHOT_IOCGET_SWAP_PAGE	_IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
#define SNAPSHOT_IOCFREE_SWAP_PAGE	_IOW(SNAPSHOT_IOC_MAGIC, 8, unsigned long)
#define SNAPSHOT_IOC_MAXNR	8

#define	LINUX_REBOOT_MAGIC1	0xfee1dead
#define	LINUX_REBOOT_MAGIC2	672274793

#define LINUX_REBOOT_CMD_RESTART	0x01234567
#define LINUX_REBOOT_CMD_HALT		0xCDEF0123
#define LINUX_REBOOT_CMD_POWER_OFF	0x4321FEDC
#define LINUX_REBOOT_CMD_RESTART2	0xA1B2C3D4
#define LINUX_REBOOT_CMD_SW_SUSPEND	0xD000FCE2

struct new_utsname {
	char sysname[65];
	char nodename[65];
	char release[65];
	char version[65];
	char machine[65];
	char domainname[65];
};

struct swsusp_info {
	struct new_utsname	uts;
	unsigned int		version_code;
	unsigned long		num_physpages;
	int			cpus;
	unsigned long		image_pages;
	unsigned long		pages;
} __attribute__((aligned(PAGE_SIZE)));

#define SWSUSP_SIG	"S1SUSPEND"

static struct swsusp_header {
	char reserved[PAGE_SIZE - 20 - sizeof(long)];
	unsigned long image;
	char	orig_sig[10];
	char	sig[10];
} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;

static inline int freeze(int dev)
{
	return ioctl(dev, SNAPSHOT_IOCFREEZE, 0);
}

static inline int unfreeze(int dev)
{
	return ioctl(dev, SNAPSHOT_IOCUNFREEZE, 0);
}

static inline int atomic_snapshot(int dev, int *in_suspend)
{
	return ioctl(dev, SNAPSHOT_IOCATOMIC_SNAPSHOT, in_suspend);
}

static inline int atomic_restore(int dev)
{
	return ioctl(dev, SNAPSHOT_IOCATOMIC_RESTORE, 0);
}

static inline int set_image_size(int dev, unsigned int size)
{
	return ioctl(dev, SNAPSHOT_IOCSET_IMAGE_SIZE, size);
}

static inline void reboot(void)
{
	syscall(SYS_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
		LINUX_REBOOT_CMD_RESTART, 0);
}

static inline void power_off(void)
{
	syscall(SYS_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
		LINUX_REBOOT_CMD_POWER_OFF, 0);
}

/*
 *	The swap map is a data structure used for keeping track of each page
 *	written to the swap.  It consists of many swap_map_page structures
 *	that contain each an array of MAP_PAGE_SIZE swap entries.
 *	These structures are linked together with the help of either the
 *	.next (in memory) or the .next_swap (in swap) member.
 *
 *	The swap map is created during suspend.  At that time we need to keep
 *	it in memory, because we have to free all of the allocated swap
 *	entries if an error occurs.  The memory needed is preallocated
 *	so that we know in advance if there's enough of it.
 *
 *	The first swap_map_page structure is filled with the swap entries that
 *	correspond to the first MAP_PAGE_SIZE data pages written to swap and
 *	so on.  After the all of the data pages have been written, the order
 *	of the swap_map_page structures in the map is reversed so that they
 *	can be read from swap in the original order.  This causes the data
 *	pages to be loaded in exactly the same order in which they have been
 *	saved.
 *
 *	During resume we only need to use one swap_map_page structure
 *	at a time, which means that we only need to use two memory pages for
 *	reading the image - one for reading the swap_map_page structures
 *	and the second for reading the data pages from swap.
 */

#define MAP_PAGE_SIZE	((PAGE_SIZE - sizeof(long) - sizeof(void *)) \
			/ sizeof(long))

struct swap_map_page {
	unsigned long		entries[MAP_PAGE_SIZE];
	unsigned long		next_swap;
	struct swap_map_page	*next;
};

/*
 *	The swap_map_handle structure is used for handling the swap map in
 *	a file-alike way
 */

struct swap_map_handle {
	struct swap_map_page *cur;
	unsigned int k;
	int fd;
};

#define SNAPSHOT_DEVICE	"/dev/snapshot"
#define RESUME_DEVICE "/dev/hdc3"

#define DEFAULT_IMAGE_SIZE	500