include/vm/vpage.h

   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  * Copyright (c) 2015, Joyent, Inc.  All rights reserved.
  25  */
  26
  27 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 /*
  31  * University Copyright- Copyright (c) 1982, 1986, 1988
  32  * The Regents of the University of California
  33  * All Rights Reserved
  34  *
  35  * University Acknowledgment- Portions of this document are derived from
  36  * software developed by the University of California, Berkeley, and its
  37  * contributors.
  38  */
  39
  40 #ifndef _VM_VPAGE_H
  41 #define _VM_VPAGE_H
  42
  43 #ifdef  __cplusplus
  44 extern "C" {
  45 #endif
  46
  47 /*
  48  * VM - Information per virtual page.
  49  */
  50 struct vpage {
  51         uchar_t nvp_prot;       /* see <sys/mman.h> prot flags */
  52         uchar_t nvp_advice;     /* pplock & <sys/mman.h> madvise flags */
  53 };
  54
  55 /*
  56  * This was changed from a bitfield to flags/macros in order
  57  * to conserve space (uchar_t bitfields are not ANSI).  This could
  58  * have been condensed to a uchar_t, but at the expense of complexity.
  59  * We've stolen three bits from the top of nvp_advice: the first to store
  60  * pplock, the second to identify pages for which we have reserved
  61  * swap space, but have not necessarily allocated anon slots, and the third to
  62  * indicate that the page should be zeroed on fork.
  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 #define VP_INHZERO_MASK (0x20)  /* zero page on fork() */
  73
  74 #define VPP_PROT(vpp)   ((vpp)->nvp_prot)
  75 #define VPP_ADVICE(vpp) ((vpp)->nvp_advice & VP_ADVICE_MASK)
  76 #define VPP_ISPPLOCK(vpp) \
  77         ((uchar_t)((vpp)->nvp_advice & VP_PPLOCK_MASK))
  78 #define VPP_ISSWAPRES(vpp) \
  79         ((uchar_t)((vpp)->nvp_advice & VP_SWAPRES_MASK))
  80 #define VPP_ISINHZERO(vpp) \
  81         ((uchar_t)((vpp)->nvp_advice & VP_INHZERO_MASK))
  82
  83 #define VPP_SETPROT(vpp, x)     ((vpp)->nvp_prot = (x))
  84 #define VPP_SETADVICE(vpp, x) \
  85         ((vpp)->nvp_advice = ((vpp)->nvp_advice & ~VP_ADVICE_MASK) | \
  86                 ((x) & VP_ADVICE_MASK))
  87 #define VPP_SETPPLOCK(vpp)      ((vpp)->nvp_advice |= VP_PPLOCK_MASK)
  88 #define VPP_CLRPPLOCK(vpp)      ((vpp)->nvp_advice &= ~VP_PPLOCK_MASK)
  89 #define VPP_SETSWAPRES(vpp)     ((vpp)->nvp_advice |= VP_SWAPRES_MASK)
  90 #define VPP_CLRSWAPRES(vpp)     ((vpp)->nvp_advice &= ~VP_SWAPRES_MASK)
  91 #define VPP_SETINHZERO(vpp)     ((vpp)->nvp_advice |= VP_INHZERO_MASK)
  92 #define VPP_CLRINHZERO(vpp)     ((vpp)->nvp_advice &= ~VP_INHZERO_MASK)
  93
  94 #ifdef  __cplusplus
  95 }
  96 #endif
  97
  98 #endif  /* _VM_VPAGE_H */