sys/vm/vm_object.h

   1 /*
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * The Mach Operating System project at Carnegie-Mellon University.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  *      from: @(#)vm_object.h   8.3 (Berkeley) 1/12/94
  37  *
  38  *
  39  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
  40  * All rights reserved.
  41  *
  42  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
  43  *
  44  * Permission to use, copy, modify and distribute this software and
  45  * its documentation is hereby granted, provided that both the copyright
  46  * notice and this permission notice appear in all copies of the
  47  * software, derivative works or modified versions, and any portions
  48  * thereof, and that both notices appear in supporting documentation.
  49  *
  50  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  51  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
  52  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  53  *
  54  * Carnegie Mellon requests users of this software to return to
  55  *
  56  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  57  *  School of Computer Science
  58  *  Carnegie Mellon University
  59  *  Pittsburgh PA 15213-3890
  60  *
  61  * any improvements or extensions that they make and grant Carnegie the
  62  * rights to redistribute these changes.
  63  *
  64  * $FreeBSD: src/sys/vm/vm_object.h,v 1.63.2.3 2003/05/26 19:17:56 alc Exp $
  65  * $DragonFly: src/sys/vm/vm_object.h,v 1.14 2007/06/08 02:00:47 dillon Exp $
  66  */
  67
  68 /*
  69  *      Virtual memory object module definitions.
  70  */
  71
  72 #ifndef _VM_VM_OBJECT_H_
  73 #define _VM_VM_OBJECT_H_
  74
  75 #ifndef _SYS_TYPES_H_
  76 #include <sys/types.h>
  77 #endif
  78 #if defined(_KERNEL) && !defined(_SYS_SYSTM_H_)
  79 #include <sys/systm.h>
  80 #endif
  81 #ifndef _SYS_QUEUE_H_
  82 #include <sys/queue.h>
  83 #endif
  84 #ifndef _SYS_TREE_H_
  85 #include <sys/tree.h>
  86 #endif
  87 #ifndef _MACHINE_ATOMIC_H_
  88 #include <machine/atomic.h>
  89 #endif
  90 #ifndef _VM_VM_H_
  91 #include <vm/vm.h>
  92 #endif
  93 #ifndef _VM_VM_PAGE_H_
  94 #include <vm/vm_page.h>
  95 #endif
  96
  97 #ifdef _KERNEL
  98
  99 #ifndef _SYS_THREAD2_H_
 100 #include <sys/thread2.h>
 101 #endif
 102
 103 #endif
 104
 105 struct swblock;
 106 struct swblock_rb_tree;
 107 int rb_swblock_compare(struct swblock *, struct swblock *);
 108
 109 RB_PROTOTYPE2(swblock_rb_tree, swblock, swb_entry, rb_swblock_compare,
 110               vm_pindex_t);
 111
 112 enum obj_type {
 113         OBJT_DEFAULT,
 114         OBJT_SWAP,      /* object backed by swap blocks */
 115         OBJT_VNODE,     /* object backed by file pages (vnode) */
 116         OBJT_DEVICE,    /* object backed by device pages */
 117         OBJT_PHYS,      /* object backed by physical pages */
 118         OBJT_DEAD,      /* dead object */
 119         OBJT_MARKER     /* marker object */
 120 };
 121 typedef u_char objtype_t;
 122
 123 /*
 124  * vm_object_lock       A lock covering byte ranges within a VM object
 125  *
 126  */
 127 struct vm_object_lock {
 128         struct vm_object_lock *next;
 129         int     type;                   /* type of lock */
 130         int     waiting;                /* someone is waiting on the lock */
 131         off_t   base;                   /* byte offset into object */
 132         off_t   bytes;                  /* extent in bytes */
 133 };
 134
 135 #define VMOBJ_LOCK_SHARED       1
 136 #define VMOBJ_LOCK_EXCL         2
 137
 138 /*
 139  * vm_object            A VM object which represents an arbitrarily sized
 140  *                      data store.
 141  */
 142 struct vm_object {
 143         TAILQ_ENTRY(vm_object) object_list; /* list of all objects */
 144         LIST_HEAD(, vm_object) shadow_head; /* objects that this is a shadow for */
 145         LIST_ENTRY(vm_object) shadow_list; /* chain of shadow objects */
 146         RB_HEAD(vm_page_rb_tree, vm_page) rb_memq;      /* resident pages */
 147         int generation;                 /* generation ID */
 148         vm_pindex_t size;               /* Object size */
 149         int ref_count;                  /* How many refs?? */
 150         int shadow_count;               /* how many objects that this is a shadow for */
 151         int hash_rand;                  /* vm hash table randomizer     */
 152         objtype_t type;                 /* type of pager */
 153         u_short flags;                  /* see below */
 154         u_short pg_color;               /* color of first page in obj */
 155         u_short paging_in_progress;     /* Paging (in or out) so don't collapse or destroy */
 156         int resident_page_count;        /* number of resident pages */
 157         struct vm_object *backing_object; /* object that I'm a shadow of */
 158         vm_ooffset_t backing_object_offset;/* Offset in backing object */
 159         TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
 160         void *handle;
 161         vm_object_lock_t range_locks;
 162         union {
 163                 /*
 164                  * Device pager
 165                  *
 166                  *      devp_pglist - list of allocated pages
 167                  */
 168                 struct {
 169                         TAILQ_HEAD(, vm_page) devp_pglist;
 170                 } devp;
 171         } un_pager;
 172
 173         /*
 174          * OBJT_SWAP and OBJT_VNODE VM objects may have swap backing
 175          * store.  For vnodes the swap backing store acts as a fast
 176          * data cache but the vnode contains the official data.
 177          */
 178         RB_HEAD(swblock_rb_tree, swblock) swblock_root;
 179         int     swblock_count;
 180 };
 181
 182 /*
 183  * Flags
 184  */
 185 #define OBJ_ACTIVE      0x0004          /* active objects */
 186 #define OBJ_DEAD        0x0008          /* dead objects (during rundown) */
 187 #define OBJ_NOSPLIT     0x0010          /* dont split this object */
 188 #define OBJ_PIPWNT      0x0040          /* paging in progress wanted */
 189 #define OBJ_WRITEABLE   0x0080          /* object has been made writable */
 190 #define OBJ_MIGHTBEDIRTY 0x0100         /* object might be dirty */
 191 #define OBJ_CLEANING    0x0200
 192 #define OBJ_DEADWNT     0x1000          /* waiting because object is dead */
 193 #define OBJ_ONEMAPPING  0x2000          /* One USE (a single, non-forked) mapping flag */
 194
 195 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
 196 #define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
 197
 198 #ifdef  _KERNEL
 199
 200 #define OBJPC_SYNC      0x1                     /* sync I/O */
 201 #define OBJPC_INVAL     0x2                     /* invalidate */
 202 #define OBJPC_NOSYNC    0x4                     /* skip if PG_NOSYNC */
 203
 204 TAILQ_HEAD(object_q, vm_object);
 205
 206 extern struct object_q vm_object_list;  /* list of allocated objects */
 207
 208  /* lock for object list and count */
 209
 210 extern struct vm_object kernel_object;  /* the single kernel object */
 211
 212 #endif                          /* _KERNEL */
 213
 214 #ifdef _KERNEL
 215
 216 static __inline void
 217 vm_object_set_flag(vm_object_t object, u_int bits)
 218 {
 219         atomic_set_short(&object->flags, bits);
 220 }
 221
 222 static __inline void
 223 vm_object_clear_flag(vm_object_t object, u_int bits)
 224 {
 225         atomic_clear_short(&object->flags, bits);
 226 }
 227
 228 static __inline void
 229 vm_object_pip_add(vm_object_t object, int i)
 230 {
 231         atomic_add_short(&object->paging_in_progress, i);
 232 }
 233
 234 static __inline void
 235 vm_object_pip_subtract(vm_object_t object, int i)
 236 {
 237         atomic_subtract_short(&object->paging_in_progress, i);
 238 }
 239
 240 static __inline void
 241 vm_object_pip_wakeup(vm_object_t object)
 242 {
 243         atomic_subtract_short(&object->paging_in_progress, 1);
 244         if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
 245                 vm_object_clear_flag(object, OBJ_PIPWNT);
 246                 wakeup(object);
 247         }
 248 }
 249
 250 static __inline void
 251 vm_object_pip_wakeupn(vm_object_t object, int i)
 252 {
 253         if (i)
 254                 atomic_subtract_short(&object->paging_in_progress, i);
 255         if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
 256                 vm_object_clear_flag(object, OBJ_PIPWNT);
 257                 wakeup(object);
 258         }
 259 }
 260
 261 static __inline void
 262 vm_object_pip_sleep(vm_object_t object, char *waitid)
 263 {
 264         if (object->paging_in_progress) {
 265                 crit_enter();
 266                 if (object->paging_in_progress) {
 267                         vm_object_set_flag(object, OBJ_PIPWNT);
 268                         tsleep(object, 0, waitid, 0);
 269                 }
 270                 crit_exit();
 271         }
 272 }
 273
 274 static __inline void
 275 vm_object_pip_wait(vm_object_t object, char *waitid)
 276 {
 277         while (object->paging_in_progress)
 278                 vm_object_pip_sleep(object, waitid);
 279 }
 280
 281 vm_object_t vm_object_allocate (objtype_t, vm_pindex_t);
 282 void _vm_object_allocate (objtype_t, vm_pindex_t, vm_object_t);
 283 boolean_t vm_object_coalesce (vm_object_t, vm_pindex_t, vm_size_t, vm_size_t);
 284 void vm_object_collapse (vm_object_t);
 285 void vm_object_deallocate (vm_object_t);
 286 void vm_object_terminate (vm_object_t);
 287 void vm_object_set_writeable_dirty (vm_object_t);
 288 void vm_object_init (void);
 289 void vm_object_page_clean (vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t);
 290 void vm_object_page_remove (vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t);
 291 void vm_object_pmap_copy (vm_object_t, vm_pindex_t, vm_pindex_t);
 292 void vm_object_pmap_copy_1 (vm_object_t, vm_pindex_t, vm_pindex_t);
 293 void vm_object_pmap_remove (vm_object_t, vm_pindex_t, vm_pindex_t);
 294 void vm_object_reference (vm_object_t);
 295 void vm_object_shadow (vm_object_t *, vm_ooffset_t *, vm_size_t);
 296 void vm_object_madvise (vm_object_t, vm_pindex_t, int, int);
 297 void vm_object_init2 (void);
 298 vm_page_t vm_fault_object_page(vm_object_t, vm_ooffset_t, vm_prot_t, int, int *);
 299 void vm_object_dead_sleep(vm_object_t, const char *);
 300 void vm_object_dead_wakeup(vm_object_t);
 301
 302 #endif                          /* _KERNEL */
 303
 304 #endif                          /* _VM_VM_OBJECT_H_ */