usr/src/uts/common/sys/swap.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, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1983, 1984, 1985, 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 _SYS_SWAP_H
  41 #define _SYS_SWAP_H
  42
  43 #pragma ident   "%Z%%M% %I%     %E% SMI"
  44
  45 #include <sys/isa_defs.h>
  46 #include <sys/feature_tests.h>
  47 #include <vm/anon.h>
  48 #include <sys/fs/swapnode.h>
  49
  50 #ifdef  __cplusplus
  51 extern "C" {
  52 #endif
  53
  54 #if !defined(_LP64) && _FILE_OFFSET_BITS == 64
  55 #error  "Cannot use swapctl in the large files compilation environment"
  56 #endif
  57
  58 /* The following are for the swapctl system call */
  59
  60 #define SC_ADD          1       /* add a specified resource for swapping */
  61 #define SC_LIST         2       /* list all the swapping resources */
  62 #define SC_REMOVE       3       /* remove the specified swapping resource */
  63 #define SC_GETNSWP      4       /* get number of swap resources configured */
  64 #define SC_AINFO        5       /* get anonymous memory resource information */
  65
  66 typedef struct swapres {
  67         char    *sr_name;       /* pathname of the resource specified */
  68         off_t   sr_start;       /* starting offset of the swapping resource */
  69         off_t   sr_length;      /* length of the swap area */
  70 } swapres_t;
  71
  72 typedef struct swapent {
  73         char    *ste_path;      /* get the name of the swap file */
  74         off_t   ste_start;      /* starting block for swapping */
  75         off_t   ste_length;     /* length of swap area */
  76         long    ste_pages;      /* numbers of pages for swapping */
  77         long    ste_free;       /* numbers of ste_pages free */
  78         int     ste_flags;      /* see below */
  79 } swapent_t;
  80
  81 typedef struct swaptable {
  82         int     swt_n;                  /* number of swapents following */
  83         struct  swapent swt_ent[1];     /* array of swt_n swapents */
  84 } swaptbl_t;
  85
  86
  87 #if defined(_SYSCALL32)
  88
  89 /* Kernel's view of user ILP32 swapres and swapent structures */
  90
  91 typedef struct swapres32 {
  92         caddr32_t sr_name;      /* pathname of the resource specified */
  93         off32_t sr_start;       /* starting offset of the swapping resource */
  94         off32_t sr_length;      /* length of the swap area */
  95 } swapres32_t;
  96
  97 typedef struct swapent32 {
  98         caddr32_t ste_path;     /* get the name of the swap file */
  99         off32_t ste_start;      /* starting block for swapping */
 100         off32_t ste_length;     /* length of swap area */
 101         int32_t ste_pages;      /* numbers of pages for swapping */
 102         int32_t ste_free;       /* numbers of ste_pages free */
 103         int32_t ste_flags;      /* see below */
 104 } swapent32_t;
 105
 106 typedef struct  swaptable32 {
 107         int32_t swt_n;                  /* number of swapents following */
 108         struct  swapent32 swt_ent[1];   /* array of swt_n swapents */
 109 } swaptbl32_t;
 110
 111 #endif  /* _SYSCALL32 */
 112
 113 #if defined(_KERNEL)
 114 extern int swapctl(int, void *, int *);
 115 #if defined(_LP64) && defined(_SYSCALL32)
 116 extern int swapctl32(int, void *, int *);
 117 #endif /* _LP64 && _SYSCALL32 */
 118 #else /* !_KERNEL */
 119 #if defined(__STDC__)
 120 extern int swapctl(int, void *);
 121 #else
 122 extern int swapctl();
 123 #endif
 124 #endif /* _KERNEL */
 125
 126
 127 /* ste_flags values */
 128
 129 #define ST_INDEL        0x01            /* Deletion of file is in progress. */
 130                                         /* Prevents others from deleting or */
 131                                         /* allocating from it */
 132 #define ST_DOINGDEL     0x02            /* Set during deletion of file */
 133                                         /* Clearing during deletion signals */
 134                                         /* that you want to add the file back */
 135                                         /* again, and will eventually cause */
 136                                         /* it to be added back */
 137
 138 /*
 139  * VM - virtual swap device.
 140  */
 141 struct  swapinfo {
 142         ulong_t si_soff;                /* starting offset (bytes) of file */
 143         ulong_t si_eoff;                /* ending offset (bytes) of file */
 144         struct  vnode *si_vp;           /* vnode (commonvp if device) */
 145         struct  swapinfo *si_next;      /* next swap area */
 146         int     si_allocs;              /* # of conseq. allocs from this area */
 147         short   si_flags;               /* flags defined below */
 148         pgcnt_t si_npgs;                /* number of pages of swap space */
 149         pgcnt_t si_nfpgs;               /* number of free pages of swap space */
 150         int     si_pnamelen;            /* swap file name length + 1 */
 151         char    *si_pname;              /* swap file name */
 152         ssize_t si_mapsize;             /* # bytes allocated for bitmap */
 153         uint_t  *si_swapslots;          /* bitmap of slots, unset == free */
 154         pgcnt_t si_hint;                /* first page to check if free */
 155         ssize_t si_checkcnt;            /* # of checks to find freeslot */
 156         ssize_t si_alloccnt;            /* used to find ave checks */
 157 };
 158
 159 /*
 160  * Stuff to convert an anon slot pointer to a page name.
 161  * Because the address of the slot (ap) is a unique identifier, we
 162  * use it to generate a unique (vp,off), as shown below.
 163  *
 164  *      |<-- 11 bits -->|<------32 - 11 --------->|
 165  *         vp index bits        off bits
 166  *
 167  * The off bits are shifted PAGESHIFT to directly form a page aligned
 168  * offset; the vp index bits map 1-1 to a vnode.
 169  *
 170  * Note: if we go to 64 bit offsets, we could use all the bits as the
 171  * unique offset and just have one vnode.
 172  */
 173 #define AN_OFFSHIFT     11                      /* vnum # bits */
 174 #define AN_VPSHIFT      21                      /* 32 - 11 */
 175 #define AN_VPSIZEMASK   0x7FF                   /* vp index mask */
 176 #define MAX_SWAP_VNODES 2048                    /* 1 << AN_OFFSHIFT */
 177 #define AN_CACHE_ALIGN  16                      /* anon address aligned */
 178                                                 /* 16 bytes */
 179 /*
 180  * Convert from an anon slot to associated vnode and offset.
 181  */
 182 #define swap_xlate(AP, VPP, OFFP)                                       \
 183 {                                                                       \
 184         *(VPP) = (AP)->an_vp;                                           \
 185         *(OFFP) = (AP)->an_off;                                         \
 186 }
 187 #define swap_xlate_nopanic      swap_xlate
 188
 189 /*
 190  * Get a vnode name for an anon slot.
 191  * The vnum, offset are derived from anon struct address which is
 192  * 16 bytes aligned. To get swap offset the anon address is shifted
 193  * by additional 11 bits which yields 32K aligned swap offset
 194  * (11 bits plus 4 bits alignment).
 195  * The vnum (vnode index) is created from bits 31-21.
 196  * The 64 bit swap offset is created from bits 63-32 and 20-4.
 197  * The 32 bit offset is created from bits 20-4.
 198  *
 199  * +-----------...----------+--------+-----------------------+----+
 200  * |        swap offset     |  vnum  |       swap offset     |0000|
 201  * +-----------...----------+--------+-----------------------+----+
 202  *  63                    32 31    21 20                    4 3  0
 203  */
 204 #define swap_alloc(AP)                                                  \
 205 {                                                                       \
 206         (AP)->an_vp = swapfs_getvp(((uintptr_t)(AP) >> AN_VPSHIFT)      \
 207             & AN_VPSIZEMASK);                                           \
 208         (AP)->an_off = (anoff_t)(((uintptr_t)(AP) & ~(uintptr_t)0xFFFFFFFF) \
 209             | (((uintptr_t)(AP) << AN_OFFSHIFT) & (uintptr_t)0xFFFFFFFF)); \
 210 }
 211
 212 /*
 213  * Free the page name for the specified anon slot.
 214  * For now there's nothing to do.
 215  */
 216 #define swap_free(AP)
 217
 218 /* Flags for swap_phys_alloc */
 219 #define SA_NOT  0x01    /* Must have slot from swap dev other than input one */
 220
 221 /* Special error codes for swap_newphysname() */
 222 #define SE_NOSWAP       -1      /* No physical swap slots available */
 223 #define SE_NOANON       -2      /* No anon slot for swap slot */
 224
 225 #ifdef _KERNEL
 226 extern struct anon *swap_anon(struct vnode *vp, u_offset_t off);
 227 extern int swap_phys_alloc(struct vnode **vpp, u_offset_t *offp, size_t *lenp,
 228     uint_t flags);
 229 extern void swap_phys_free(struct vnode *vp, u_offset_t off, size_t len);
 230 extern int swap_getphysname(struct vnode *vp, u_offset_t off,
 231     struct vnode **pvpp, u_offset_t *poffp);
 232 extern int swap_newphysname(struct vnode *vp, u_offset_t offset,
 233     u_offset_t *offp, size_t *lenp, struct vnode **pvpp, u_offset_t *poffp);
 234
 235 extern struct swapinfo *swapinfo;
 236 extern int swap_debug;
 237 #endif  /* _KERNEL */
 238
 239 #ifdef SWAP_DEBUG
 240 #define SW_RENAME       0x01
 241 #define SW_RESV         0x02
 242 #define SW_ALLOC        0x04
 243 #define SW_CTL          0x08
 244 #define SWAP_PRINT(f, s, x1, x2, x3, x4, x5) \
 245                 if (swap_debug & f) \
 246                         printf(s, x1, x2, x3, x4, x5);
 247 #else   /* SWAP_DEBUG */
 248 #define SWAP_PRINT(f, s, x1, x2, x3, x4, x5)
 249 #endif  /* SWAP_DEBUG */
 250
 251 #ifdef  __cplusplus
 252 }
 253 #endif
 254
 255 #endif  /* _SYS_SWAP_H */