#ifndef __KSM_H
#define __KSM_H

#include <linux/types.h>
#include <linux/mm.h>
#include <linux/rwsem.h>
#include <linux/spinlock.h>
#include <linux/list.h>

/* this should really go to linux/miscdevice.h */
#define KSM_MINOR 233

#define KSM_MAX_SMAS 256

#define SharedPage 1

struct ksm_mem_slot {
	struct list_head link;
	struct list_head sma_link;
	struct mm_struct *mm;
	unsigned long addr; /* the begining of the virtual address */
	unsigned int npages; /* number of pages to share */
};

/*
 * sma - shared memory area, each process have its own sma that contain the
 * information about the slots that it own
 */
struct ksm_sma {
	struct list_head sma_slots;
};

struct ksm {
	struct list_head slots;
	struct rw_semaphore slots_lock;

	int npages_hash;
	struct hlist_head *page_hash;
	int nrmaps_hash;
	struct hlist_head *rmap_hash;

	struct kmem_cache *page_item_cache;
	struct kmem_cache *rmap_item_cache;

	struct address_space address_space;
	spinlock_t hash_lock;
};

struct ksm_scan {
	struct ksm_mem_slot *slot_index; /* the slot we are scanning now */
	int page_index; /* the page inside sma that is now being scanned */
};

struct page_item {
	struct hlist_node link;
	struct mm_struct *mm;
	unsigned long addr;
};

struct rmap_item {
	struct hlist_node link;
	struct page_item *page_item;
	unsigned long oldindex;
};

#endif