xref: /illumos-gate/usr/src/uts/common/vm/vpage.h (revision b07ce584f4e28873b8927d7f83d9d3275a0f3ed2)
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
45 extern "C" {
46 #endif
47 
48 /*
49  * VM - Information per virtual page.
50  */
51 struct 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