Current File : //usr/share/src/uts/i86pc/vm/hment.h

/*
 * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.
 */

#ifndef	_VM_HMENT_H
#define	_VM_HMENT_H

#ifdef	__cplusplus
extern "C" {
#endif


struct hment;
typedef struct hment hment_t;

#if defined(_KERNEL)

/*
 * Remove a page mapping, finds the matching mapping and unlinks it from
 * the page_t. If it returns a non-NULL pointer, the pointer must be
 * freed via hment_free() after doing x86_hm_exit().
 */
extern hment_t *hment_remove(page_t *, htable_t *ht, uint_t entry);
extern void hment_free(hment_t *);
extern hment_t *hment_alloc();

/*
 * Iterators to walk through all mappings of a page.
 */
extern hment_t *hment_walk(page_t *, htable_t **, uint_t *, hment_t *);
extern hment_t *hment_walk_all(page_t **, htable_t **, uint_t *, hment_t *,
	uint_t *);

/*
 * Prepare a page for a new mapping
 */
extern hment_t *hment_prepare(htable_t *ht, uint_t entry, page_t *);

/*
 * Used by hat_share to promote embeded mapping with preallocated hment
 * to avoid mlist lock resursion.
 */
extern void hment_promote(hment_t *, page_t *);

/*
 * Add a mapping to a page's mapping list
 */
extern void hment_assign(htable_t *ht, uint_t entry, page_t *, hment_t *);

/*
 * initialize hment data structures
 */
extern void hment_init(void);

/*
 * lock/unlock a page_t's mapping list/pte entry
 */
extern void x86_hm_enter(page_t *);
extern void x86_hm_exit(page_t *);
extern int x86_hm_held(page_t *pp);

/*
 * Called to allocate additional hments for reserve.
 *
 * The hment_reserve_count is exported for use by htable_hment_steal()
 */
extern void hment_reserve(uint_t);
extern uint_t hment_reserve_count;

/*
 * Used to readjust the hment reserve after the reserve list has been used.
 * Also called after boot to release left over boot reserves.
 */
extern void hment_adjust_reserve(void);

/*
 * Return the number of mappings of a page_t
 */
extern ulong_t hment_mapcnt(page_t *, int, ulong_t);

#endif	/* _KERNEL */


#ifdef	__cplusplus
}
#endif

#endif	/* _VM_HMENT_H */