vpage.h revision 9d12795f87b63c2e39e87bff369182edd34677d3
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
* Copyright (c) 2015, Joyent, Inc. All rights reserved.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* University Copyright- Copyright (c) 1982, 1986, 1988
* The Regents of the University of California
* All Rights Reserved
*
* University Acknowledgment- Portions of this document are derived from
* software developed by the University of California, Berkeley, and its
* contributors.
*/
#ifndef _VM_VPAGE_H
#define _VM_VPAGE_H
#ifdef __cplusplus
extern "C" {
#endif
/*
* VM - Information per virtual page.
*/
struct vpage {
uchar_t nvp_prot; /* see <sys/mman.h> prot flags */
uchar_t nvp_advice; /* pplock & <sys/mman.h> madvise flags */
};
/*
* This was changed from a bitfield to flags/macros in order
* to conserve space (uchar_t bitfields are not ANSI). This could
* have been condensed to a uchar_t, but at the expense of complexity.
* We've stolen three bits from the top of nvp_advice: the first to store
* pplock, the second to identify pages for which we have reserved
* swap space, but have not necessarily allocated anon slots, and the third to
* indicate that the page should be zeroed on fork.
*
* WARNING: VPP_SETADVICE(vpp, x) evaluates vpp twice, and VPP_PLOCK(vpp)
* returns a positive integer when the lock is held, not necessarily (1).
*/
#define VP_ADVICE_MASK (0x07)
#define VP_PPLOCK_MASK (0x80) /* physical page locked by me */
#define VP_PPLOCK_SHIFT (0x07) /* offset of lock hiding inside nvp_advice */
#define VP_SWAPRES_MASK (0x40) /* Swap space has been reserved, but we */
/* might not have allocated an anon slot */
#define VP_INHZERO_MASK (0x20) /* zero page on fork() */
#define VPP_PROT(vpp) ((vpp)->nvp_prot)
#define VPP_ADVICE(vpp) ((vpp)->nvp_advice & VP_ADVICE_MASK)
#define VPP_ISPPLOCK(vpp) \
((uchar_t)((vpp)->nvp_advice & VP_PPLOCK_MASK))
#define VPP_ISSWAPRES(vpp) \
((uchar_t)((vpp)->nvp_advice & VP_SWAPRES_MASK))
#define VPP_ISINHZERO(vpp) \
((uchar_t)((vpp)->nvp_advice & VP_INHZERO_MASK))
#define VPP_SETPROT(vpp, x) ((vpp)->nvp_prot = (x))
#define VPP_SETADVICE(vpp, x) \
((vpp)->nvp_advice = ((vpp)->nvp_advice & ~VP_ADVICE_MASK) | \
((x) & VP_ADVICE_MASK))
#define VPP_SETPPLOCK(vpp) ((vpp)->nvp_advice |= VP_PPLOCK_MASK)
#define VPP_CLRPPLOCK(vpp) ((vpp)->nvp_advice &= ~VP_PPLOCK_MASK)
#define VPP_SETSWAPRES(vpp) ((vpp)->nvp_advice |= VP_SWAPRES_MASK)
#define VPP_CLRSWAPRES(vpp) ((vpp)->nvp_advice &= ~VP_SWAPRES_MASK)
#define VPP_SETINHZERO(vpp) ((vpp)->nvp_advice |= VP_INHZERO_MASK)
#define VPP_CLRINHZERO(vpp) ((vpp)->nvp_advice &= ~VP_INHZERO_MASK)
#ifdef __cplusplus
}
#endif
#endif /* _VM_VPAGE_H */