swap.h

#ifndef _VM_SWAP_H
#define _VM_SWAP_H

#include <bitmap.h>

#define INVALID_SWAPADDR 0
#define SWAP_DEVICE "lhd0raw:"
#define SWAP_MIN_FACTOR 40

#define LOCK_SWAP() (lock_acquire(lk_sw))
#define UNLOCK_SWAP() (lock_release(lk_sw))

#define LOCK_PAGING_GIANT() KASSERT(curthread->t_vmp_count == 0 || curthread->t_clone ); lock_acquire(giant_paging_lock)
#define UNLOCK_PAGING_GIANT() (lock_release(giant_paging_lock))
#define LOCK_PAGING_IF_POSSIBLE() KASSERT( curthread->t_vmp_count == 0 || curthread->t_clone ); if( curthread != NULL && !curthread->t_in_interrupt ) lock_acquire( giant_paging_lock )
#define UNLOCK_PAGING_IF_POSSIBLE() if( curthread != NULL && !curthread->t_in_interrupt ) lock_release( giant_paging_lock )

/**
 * holds statistics regarding swapping.
 * ss_total: total number of pages we can hold.
 * ss_free: free pages count.
 * ss_reserved: how many of them are reserved.
 */
struct swap_stats {
	unsigned int		ss_total;
	unsigned int		ss_free;
	unsigned int		ss_reserved;
	unsigned int		ss_used;
};

void		swap_bootstrap( void );
off_t		swap_alloc(void);
void		swap_in( paddr_t, off_t );
void		swap_out( paddr_t, off_t );
void		swap_dealloc( off_t );
int		swap_reserve(unsigned);
void		swap_unreserve(unsigned);

extern struct lock	*giant_paging_lock;

#endif