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      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