vpage.h revision 6517:dc84548e930e 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27/*	  All Rights Reserved  	*/
28
29/*
30 * University Copyright- Copyright (c) 1982, 1986, 1988
31 * The Regents of the University of California
32 * All Rights Reserved
33 *
34 * University Acknowledgment- Portions of this document are derived from
35 * software developed by the University of California, Berkeley, and its
36 * contributors.
37 */
38
39#ifndef	_VM_VPAGE_H
40#define	_VM_VPAGE_H
41
42#pragma ident	"%Z%%M%	%I%	%E% SMI"
43
44#ifdef	__cplusplus
45extern "C" {
46#endif
47
48/*
49 * VM - Information per virtual page.
50 */
51struct vpage {
52	uchar_t nvp_prot;	/* see <sys/mman.h> prot flags */
53	uchar_t nvp_advice;	/* pplock & <sys/mman.h> madvise flags */
54};
55
56/*
57 * This was changed from a bitfield to flags/macros in order
58 * to conserve space (uchar_t bitfields are not ANSI).  This could
59 * have been condensed to a uchar_t, but at the expense of complexity.
60 * We've stolen two bits from the top of nvp_advice: the first to store
61 * pplock, and the second to identify pages for which we have reserved
62 * swap space, but have not necessarily allocated anon slots.
63 *
64 * WARNING: VPP_SETADVICE(vpp, x) evaluates vpp twice, and VPP_PLOCK(vpp)
65 * returns a positive integer when the lock is held, not necessarily (1).
66 */
67#define	VP_ADVICE_MASK	(0x07)
68#define	VP_PPLOCK_MASK	(0x80)	/* physical page locked by me */
69#define	VP_PPLOCK_SHIFT	(0x07)	/* offset of lock hiding inside nvp_advice */
70#define	VP_SWAPRES_MASK	(0x40)	/* Swap space has been reserved, but we */
71				/* might not have allocated an anon slot */
72
73#define	VPP_PROT(vpp)	((vpp)->nvp_prot)
74#define	VPP_ADVICE(vpp)	((vpp)->nvp_advice & VP_ADVICE_MASK)
75#define	VPP_ISPPLOCK(vpp) \
76	((uchar_t)((vpp)->nvp_advice & VP_PPLOCK_MASK))
77#define	VPP_ISSWAPRES(vpp) \
78	((uchar_t)((vpp)->nvp_advice & VP_SWAPRES_MASK))
79
80#define	VPP_SETPROT(vpp, x)	((vpp)->nvp_prot = (x))
81#define	VPP_SETADVICE(vpp, x) \
82	((vpp)->nvp_advice = ((vpp)->nvp_advice & ~VP_ADVICE_MASK) | \
83		((x) & VP_ADVICE_MASK))
84#define	VPP_SETPPLOCK(vpp)	((vpp)->nvp_advice |= VP_PPLOCK_MASK)
85#define	VPP_CLRPPLOCK(vpp)	((vpp)->nvp_advice &= ~VP_PPLOCK_MASK)
86#define	VPP_SETSWAPRES(vpp)	((vpp)->nvp_advice |= VP_SWAPRES_MASK)
87#define	VPP_CLRSWAPRES(vpp)	((vpp)->nvp_advice &= ~VP_SWAPRES_MASK)
88
89#ifdef	__cplusplus
90}
91#endif
92
93#endif	/* _VM_VPAGE_H */
94