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 _MACHINE_ATOMIC_H_
  85 #include <machine/atomic.h>
  86 #endif
  87 #ifndef _VM_VM_H_
  88 #include <vm/vm.h>
  89 #endif
  90 #ifndef _VM_VM_PAGE_H_
  91 #include <vm/vm_page.h>
  92 #endif
  93
  94 #ifdef _KERNEL
  95
  96 #ifndef _SYS_THREAD2_H_
  97 #include <sys/thread2.h>
  98 #endif
  99
 100 #endif
 101
 102 enum obj_type {
 103         OBJT_DEFAULT,
 104         OBJT_SWAP,      /* object backed by swap blocks */
 105         OBJT_VNODE,     /* object backed by file pages (vnode) */
 106         OBJT_DEVICE,    /* object backed by device pages */
 107         OBJT_PHYS,      /* object backed by physical pages */
 108         OBJT_DEAD       /* dead object */
 109 };
 110 typedef u_char objtype_t;
 111
 112 /*
 113  * vm_object_lock       A lock covering byte ranges within a VM object
 114  *
 115  */
 116 struct vm_object_lock {
 117         struct vm_object_lock *next;
 118         int     type;                   /* type of lock */
 119         int     waiting;                /* someone is waiting on the lock */
 120         off_t   base;                   /* byte offset into object */
 121         off_t   bytes;                  /* extent in bytes */
 122 };
 123
 124 #define VMOBJ_LOCK_SHARED       1
 125 #define VMOBJ_LOCK_EXCL         2
 126
 127 /*
 128  * vm_object            A VM object which represents an arbitrarily sized
 129  *                      data store.
 130  */
 131 struct vm_object {
 132         TAILQ_ENTRY(vm_object) object_list; /* list of all objects */
 133         LIST_HEAD(, vm_object) shadow_head; /* objects that this is a shadow for */
 134         LIST_ENTRY(vm_object) shadow_list; /* chain of shadow objects */
 135         RB_HEAD(vm_page_rb_tree, vm_page) rb_memq;      /* resident pages */
 136         int generation;                 /* generation ID */
 137         vm_size_t size;                 /* Object size */
 138         int ref_count;                  /* How many refs?? */
 139         int shadow_count;               /* how many objects that this is a shadow for */
 140         int hash_rand;                  /* vm hash table randomizer     */
 141         objtype_t type;                 /* type of pager */
 142         u_short flags;                  /* see below */
 143         u_short pg_color;               /* color of first page in obj */
 144         u_short paging_in_progress;     /* Paging (in or out) so don't collapse or destroy */
 145         int resident_page_count;        /* number of resident pages */
 146         struct vm_object *backing_object; /* object that I'm a shadow of */
 147         vm_ooffset_t backing_object_offset;/* Offset in backing object */
 148         TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
 149         void *handle;
 150         vm_object_lock_t range_locks;
 151         union {
 152                 /*
 153                  * Device pager
 154                  *
 155                  *      devp_pglist - list of allocated pages
 156                  */
 157                 struct {
 158                         TAILQ_HEAD(, vm_page) devp_pglist;
 159                 } devp;
 160
 161                 /*
 162                  * Swap pager
 163                  *
 164                  *      swp_bcount - number of swap 'swblock' metablocks, each
 165                  *                   contains up to 16 swapblk assignments.
 166                  *                   see vm/swap_pager.h
 167                  */
 168                 struct {
 169                         int swp_bcount;
 170                 } swp;
 171         } un_pager;
 172 };
 173
 174 /*
 175  * Flags
 176  */
 177 #define OBJ_ACTIVE      0x0004          /* active objects */
 178 #define OBJ_DEAD        0x0008          /* dead objects (during rundown) */
 179 #define OBJ_NOSPLIT     0x0010          /* dont split this object */
 180 #define OBJ_PIPWNT      0x0040          /* paging in progress wanted */
 181 #define OBJ_WRITEABLE   0x0080          /* object has been made writable */
 182 #define OBJ_MIGHTBEDIRTY 0x0100         /* object might be dirty */
 183 #define OBJ_CLEANING    0x0200
 184 #define OBJ_DEADWNT     0x1000          /* waiting because object is dead */
 185 #define OBJ_ONEMAPPING  0x2000          /* One USE (a single, non-forked) mapping flag */
 186
 187 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
 188 #define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
 189
 190 #ifdef  _KERNEL
 191
 192 #define OBJPC_SYNC      0x1                     /* sync I/O */
 193 #define OBJPC_INVAL     0x2                     /* invalidate */
 194 #define OBJPC_NOSYNC    0x4                     /* skip if PG_NOSYNC */
 195
 196 TAILQ_HEAD(object_q, vm_object);
 197
 198 extern struct object_q vm_object_list;  /* list of allocated objects */
 199
 200  /* lock for object list and count */
 201
 202 extern struct vm_object kernel_object;  /* the single kernel object */
 203
 204 #endif                          /* _KERNEL */
 205
 206 #ifdef _KERNEL
 207
 208 static __inline void
 209 vm_object_set_flag(vm_object_t object, u_int bits)
 210 {
 211         atomic_set_short(&object->flags, bits);
 212 }
 213
 214 static __inline void
 215 vm_object_clear_flag(vm_object_t object, u_int bits)
 216 {
 217         atomic_clear_short(&object->flags, bits);
 218 }
 219
 220 static __inline void
 221 vm_object_pip_add(vm_object_t object, int i)
 222 {
 223         atomic_add_short(&object->paging_in_progress, i);
 224 }
 225
 226 static __inline void
 227 vm_object_pip_subtract(vm_object_t object, int i)
 228 {
 229         atomic_subtract_short(&object->paging_in_progress, i);
 230 }
 231
 232 static __inline void
 233 vm_object_pip_wakeup(vm_object_t object)
 234 {
 235         atomic_subtract_short(&object->paging_in_progress, 1);
 236         if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
 237                 vm_object_clear_flag(object, OBJ_PIPWNT);
 238                 wakeup(object);
 239         }
 240 }
 241
 242 static __inline void
 243 vm_object_pip_wakeupn(vm_object_t object, int i)
 244 {
 245         if (i)
 246                 atomic_subtract_short(&object->paging_in_progress, i);
 247         if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
 248                 vm_object_clear_flag(object, OBJ_PIPWNT);
 249                 wakeup(object);
 250         }
 251 }
 252
 253 static __inline void
 254 vm_object_pip_sleep(vm_object_t object, char *waitid)
 255 {
 256         if (object->paging_in_progress) {
 257                 crit_enter();
 258                 if (object->paging_in_progress) {
 259                         vm_object_set_flag(object, OBJ_PIPWNT);
 260                         tsleep(object, 0, waitid, 0);
 261                 }
 262                 crit_exit();
 263         }
 264 }
 265
 266 static __inline void
 267 vm_object_pip_wait(vm_object_t object, char *waitid)
 268 {
 269         while (object->paging_in_progress)
 270                 vm_object_pip_sleep(object, waitid);
 271 }
 272
 273 vm_object_t vm_object_allocate (objtype_t, vm_size_t);
 274 void _vm_object_allocate (objtype_t, vm_size_t, vm_object_t);
 275 boolean_t vm_object_coalesce (vm_object_t, vm_pindex_t, vm_size_t, vm_size_t);
 276 void vm_object_collapse (vm_object_t);
 277 void vm_object_deallocate (vm_object_t);
 278 void vm_object_terminate (vm_object_t);
 279 void vm_object_set_writeable_dirty (vm_object_t);
 280 void vm_object_init (void);
 281 void vm_object_page_clean (vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t);
 282 void vm_object_page_remove (vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t);
 283 void vm_object_pmap_copy (vm_object_t, vm_pindex_t, vm_pindex_t);
 284 void vm_object_pmap_copy_1 (vm_object_t, vm_pindex_t, vm_pindex_t);
 285 void vm_object_pmap_remove (vm_object_t, vm_pindex_t, vm_pindex_t);
 286 void vm_object_reference (vm_object_t);
 287 void vm_object_shadow (vm_object_t *, vm_ooffset_t *, vm_size_t);
 288 void vm_object_madvise (vm_object_t, vm_pindex_t, int, int);
 289 void vm_object_init2 (void);
 290 vm_page_t vm_fault_object_page(vm_object_t, vm_ooffset_t, vm_prot_t, int, int *);
 291 void vm_object_dead_sleep(vm_object_t, const char *);
 292 void vm_object_dead_wakeup(vm_object_t);
 293
 294 #endif                          /* _KERNEL */
 295
 296 #endif                          /* _VM_VM_OBJECT_H_ */