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. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  *      from: @(#)vm_object.h   8.3 (Berkeley) 1/12/94
  33  *
  34  *
  35  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
  36  * All rights reserved.
  37  *
  38  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
  39  *
  40  * Permission to use, copy, modify and distribute this software and
  41  * its documentation is hereby granted, provided that both the copyright
  42  * notice and this permission notice appear in all copies of the
  43  * software, derivative works or modified versions, and any portions
  44  * thereof, and that both notices appear in supporting documentation.
  45  *
  46  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  47  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
  48  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  49  *
  50  * Carnegie Mellon requests users of this software to return to
  51  *
  52  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  53  *  School of Computer Science
  54  *  Carnegie Mellon University
  55  *  Pittsburgh PA 15213-3890
  56  *
  57  * any improvements or extensions that they make and grant Carnegie the
  58  * rights to redistribute these changes.
  59  *
  60  * $FreeBSD: src/sys/vm/vm_object.h,v 1.63.2.3 2003/05/26 19:17:56 alc Exp $
  61  */
  62
  63 /*
  64  *      Virtual memory object module definitions.
  65  */
  66
  67 #ifndef _VM_VM_OBJECT_H_
  68 #define _VM_VM_OBJECT_H_
  69
  70 #ifndef _SYS_TYPES_H_
  71 #include <sys/types.h>
  72 #endif
  73 #if defined(_KERNEL) && !defined(_SYS_SYSTM_H_)
  74 #include <sys/systm.h>
  75 #endif
  76 #ifndef _SYS_QUEUE_H_
  77 #include <sys/queue.h>
  78 #endif
  79 #ifndef _SYS_TREE_H_
  80 #include <sys/tree.h>
  81 #endif
  82 #ifndef _SYS_THREAD_H_
  83 #include <sys/thread.h>
  84 #endif
  85 #ifndef _MACHINE_PMAP_H_
  86 #include <machine/pmap.h>
  87 #endif
  88 #ifndef _CPU_ATOMIC_H_
  89 #include <machine/atomic.h>
  90 #endif
  91 #ifndef _VM_VM_H_
  92 #include <vm/vm.h>
  93 #endif
  94 #ifndef _VM_VM_PAGE_H_
  95 #include <vm/vm_page.h>
  96 #endif
  97
  98 #ifdef _KERNEL
  99
 100 #ifndef _SYS_THREAD2_H_
 101 #include <sys/thread2.h>
 102 #endif
 103
 104 #ifndef _SYS_REFCOUNT_H_
 105 #include <sys/refcount.h>
 106 #endif
 107
 108 #endif
 109
 110 struct swblock;
 111 struct swblock_rb_tree;
 112 int rb_swblock_compare(struct swblock *, struct swblock *);
 113
 114 RB_PROTOTYPE2(swblock_rb_tree, swblock, swb_entry, rb_swblock_compare,
 115               vm_pindex_t);
 116
 117 enum obj_type {
 118         OBJT_DEFAULT,
 119         OBJT_SWAP,      /* object backed by swap blocks */
 120         OBJT_VNODE,     /* object backed by file pages (vnode) */
 121         OBJT_DEVICE,    /* object backed by device pages */
 122         OBJT_MGTDEVICE,
 123         OBJT_PHYS,      /* object backed by physical pages */
 124         OBJT_DEAD,      /* dead object */
 125         OBJT_MARKER     /* marker object */
 126 };
 127 typedef u_char objtype_t;
 128
 129 /*
 130  * A VM object which represents an arbitrarily sized data store.
 131  *
 132  * NOTE:
 133  *      shadow_head is only used by OBJT_DEFAULT or OBJT_SWAP objects.
 134  *      OBJT_VNODE objects explicitly do not keep track of who is shadowing
 135  *      them.
 136  *
 137  * LOCKING:
 138  *      vmobj_tokens[n] for object_list, hashed by address.
 139  *
 140  *      vm_object_hold/drop() for most vm_object related operations.
 141  *      OBJ_CHAINLOCK to avoid chain/shadow object collisions.
 142  */
 143 struct vm_object {
 144         TAILQ_ENTRY(vm_object) object_list; /* locked by vmobj_tokens[n] */
 145         LIST_HEAD(, vm_object) shadow_head; /* objects we are a shadow for */
 146         LIST_ENTRY(vm_object) shadow_list;  /* chain of shadow objects */
 147         RB_HEAD(vm_page_rb_tree, vm_page) rb_memq;      /* resident pages */
 148         int generation;                 /* generation ID */
 149         vm_pindex_t size;               /* Object size */
 150         int ref_count;
 151         int shadow_count;               /* count of objs we are a shadow for */
 152         vm_memattr_t memattr;           /* default memory attribute for pages */
 153         objtype_t type;                 /* type of pager */
 154         u_short flags;                  /* see below */
 155         u_short pg_color;               /* color of first page in obj */
 156         u_int paging_in_progress;       /* Paging (in or out) so don't collapse or destroy */
 157         int resident_page_count;        /* number of resident pages */
 158         u_int agg_pv_list_count;        /* aggregate pv list count */
 159         struct vm_object *backing_object; /* object that I'm a shadow of */
 160         vm_ooffset_t backing_object_offset;/* Offset in backing object */
 161         TAILQ_ENTRY(vm_object) pager_object_list; /* list of all objects of this pager type */
 162         void *handle;                   /* control handle: vp, etc */
 163         int hold_count;                 /* count prevents destruction */
 164
 165 #if defined(DEBUG_LOCKS)
 166         /*
 167          * Record threads holding a vm_object
 168          */
 169
 170 #define VMOBJ_DEBUG_ARRAY_SIZE          (32)
 171         char debug_hold_thrs[VMOBJ_DEBUG_ARRAY_SIZE][64];
 172         const char *debug_hold_file[VMOBJ_DEBUG_ARRAY_SIZE];
 173         int debug_hold_line[VMOBJ_DEBUG_ARRAY_SIZE];
 174         int     debug_index;
 175 #endif
 176
 177         union {
 178                 /*
 179                  * Device pager
 180                  *
 181                  *      devp_pglist - list of allocated pages
 182                  */
 183                 struct {
 184                         TAILQ_HEAD(, vm_page) devp_pglist;
 185                         struct cdev_pager_ops *ops;
 186                         struct cdev *dev;
 187                 } devp;
 188         } un_pager;
 189
 190         /*
 191          * OBJT_SWAP and OBJT_VNODE VM objects may have swap backing
 192          * store.  For vnodes the swap backing store acts as a fast
 193          * data cache but the vnode contains the official data.
 194          */
 195         RB_HEAD(swblock_rb_tree, swblock) swblock_root;
 196         int     swblock_count;
 197         struct  lwkt_token      token;
 198         struct md_object        md;     /* machine specific (typ pmap) */
 199         uint32_t                chainlk;/* chaining lock */
 200 };
 201
 202 /*
 203  * Flags
 204  *
 205  * NOTE: OBJ_ONEMAPPING only applies to DEFAULT and SWAP objects.  It
 206  *       may be gratuitously re-cleared in other cases but will already be
 207  *       clear in those cases.  It might not be set on other object types
 208  *       (particularly OBJT_VNODE).
 209  */
 210 #define OBJ_UNUSED0001  0x0001          /* backing_object/shadow changing */
 211 #define OBJ_ONSHADOW    0x0002          /* backing_object on shadow list */
 212 #define OBJ_ACTIVE      0x0004          /* active objects */
 213 #define OBJ_DEAD        0x0008          /* dead objects (during rundown) */
 214 #define OBJ_NOSPLIT     0x0010          /* dont split this object */
 215 #define OBJ_UNUSED0040  0x0040
 216 #define OBJ_WRITEABLE   0x0080          /* object has been made writable */
 217 #define OBJ_MIGHTBEDIRTY 0x0100         /* object might be dirty */
 218 #define OBJ_CLEANING    0x0200
 219 #define OBJ_DEADWNT     0x1000          /* waiting because object is dead */
 220 #define OBJ_ONEMAPPING  0x2000          /* flag single vm_map_entry mapping */
 221 #define OBJ_NOMSYNC     0x4000          /* disable msync() system call */
 222
 223 #define CHAINLK_EXCL    0x80000000
 224 #define CHAINLK_WAIT    0x40000000
 225 #define CHAINLK_EXCLREQ 0x20000000
 226 #define CHAINLK_MASK    0x1FFFFFFF
 227
 228 #define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
 229 #define OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
 230
 231 #define VMOBJ_HSIZE     64
 232 #define VMOBJ_HMASK     (VMOBJ_HSIZE - 1)
 233 #define VMOBJ_HASH(obj) (((intptr_t)(obj) >> 8) & VMOBJ_HMASK)
 234
 235 #ifdef  _KERNEL
 236
 237 #define OBJPC_SYNC      0x1                     /* sync I/O */
 238 #define OBJPC_INVAL     0x2                     /* invalidate */
 239 #define OBJPC_NOSYNC    0x4                     /* skip if PG_NOSYNC */
 240
 241 /*
 242  * Used to chain vm_object deallocations
 243  */
 244 struct vm_object_dealloc_list {
 245         struct vm_object_dealloc_list *next;
 246         vm_object_t     object;
 247 };
 248
 249 TAILQ_HEAD(object_q, vm_object);
 250
 251 extern struct object_q vm_object_lists[VMOBJ_HSIZE];
 252 extern struct lwkt_token vmobj_tokens[VMOBJ_HSIZE];
 253
 254
 255  /* lock for object list and count */
 256
 257 extern struct vm_object kernel_object;  /* the single kernel object */
 258 extern int vm_shared_fault;
 259
 260 #endif                          /* _KERNEL */
 261
 262 #ifdef _KERNEL
 263
 264 #define VM_OBJECT_LOCK(object)          vm_object_hold(object)
 265 #define VM_OBJECT_UNLOCK(object)        vm_object_drop(object)
 266
 267 static __inline void
 268 vm_object_set_flag(vm_object_t object, u_int bits)
 269 {
 270         atomic_set_short(&object->flags, bits);
 271 }
 272
 273 static __inline void
 274 vm_object_clear_flag(vm_object_t object, u_int bits)
 275 {
 276         atomic_clear_short(&object->flags, bits);
 277 }
 278
 279 static __inline void
 280 vm_object_pip_add(vm_object_t object, u_int i)
 281 {
 282         refcount_acquire_n(&object->paging_in_progress, i);
 283 }
 284
 285 static __inline void
 286 vm_object_pip_wakeup_n(vm_object_t object, u_int i)
 287 {
 288         refcount_release_wakeup_n(&object->paging_in_progress, i);
 289 }
 290
 291 static __inline void
 292 vm_object_pip_wakeup(vm_object_t object)
 293 {
 294         vm_object_pip_wakeup_n(object, 1);
 295 }
 296
 297 static __inline void
 298 vm_object_pip_wait(vm_object_t object, char *waitid)
 299 {
 300         refcount_wait(&object->paging_in_progress, waitid);
 301 }
 302
 303 static __inline lwkt_token_t
 304 vm_object_token(vm_object_t obj)
 305 {
 306         return (&obj->token);
 307 }
 308
 309 vm_object_t vm_object_allocate (objtype_t, vm_pindex_t);
 310 vm_object_t vm_object_allocate_hold (objtype_t, vm_pindex_t);
 311 void _vm_object_allocate (objtype_t, vm_pindex_t, vm_object_t);
 312 boolean_t vm_object_coalesce (vm_object_t, vm_pindex_t, vm_size_t, vm_size_t);
 313 void vm_object_collapse (vm_object_t, struct vm_object_dealloc_list **);
 314 void vm_object_deallocate_list(struct vm_object_dealloc_list **);
 315 void vm_object_terminate (vm_object_t);
 316 void vm_object_set_writeable_dirty (vm_object_t);
 317 void vm_object_init (void);
 318 void vm_object_page_clean (vm_object_t, vm_pindex_t, vm_pindex_t, int);
 319 void vm_object_page_remove (vm_object_t, vm_pindex_t, vm_pindex_t, boolean_t);
 320 void vm_object_pmap_copy (vm_object_t, vm_pindex_t, vm_pindex_t);
 321 void vm_object_pmap_copy_1 (vm_object_t, vm_pindex_t, vm_pindex_t);
 322 void vm_object_pmap_remove (vm_object_t, vm_pindex_t, vm_pindex_t);
 323 void vm_object_chain_wait (vm_object_t object, int shared);
 324 void vm_object_chain_acquire(vm_object_t object, int shared);
 325 void vm_object_chain_release(vm_object_t object);
 326 void vm_object_chain_release_all(vm_object_t object, vm_object_t stopobj);
 327 void vm_object_shadow (vm_object_t *, vm_ooffset_t *, vm_size_t, int);
 328 void vm_object_madvise (vm_object_t, vm_pindex_t, int, int);
 329 void vm_object_init2 (void);
 330 vm_page_t vm_fault_object_page(vm_object_t, vm_ooffset_t,
 331                                 vm_prot_t, int, int *, int *);
 332 void vm_object_lock_swap(void);
 333 void vm_object_lock(vm_object_t);
 334 void vm_object_lock_shared(vm_object_t);
 335 void vm_object_unlock(vm_object_t);
 336
 337 #if defined(DEBUG_LOCKS)
 338
 339 #define VMOBJDEBUG(x)   debug ## x
 340 #define VMOBJDBARGS     , char *file, int line
 341 #define VMOBJDBFWD      , file, line
 342
 343 #define vm_object_hold(obj)                     \
 344                 debugvm_object_hold(obj, __FILE__, __LINE__)
 345 #define vm_object_hold_try(obj)                 \
 346                 debugvm_object_hold_try(obj, __FILE__, __LINE__)
 347 #define vm_object_hold_shared(obj)              \
 348                 debugvm_object_hold_shared(obj, __FILE__, __LINE__)
 349 #define vm_object_drop(obj)                     \
 350                 debugvm_object_drop(obj, __FILE__, __LINE__)
 351 #define vm_object_reference_quick(obj)          \
 352                 debugvm_object_reference_quick(obj, __FILE__, __LINE__)
 353 #define vm_object_reference_locked(obj)         \
 354                 debugvm_object_reference_locked(obj, __FILE__, __LINE__)
 355 #define vm_object_deallocate(obj)               \
 356                 debugvm_object_deallocate(obj, __FILE__, __LINE__)
 357 #define vm_object_deallocate_locked(obj)        \
 358                 debugvm_object_deallocate_locked(obj, __FILE__, __LINE__)
 359
 360 #else
 361
 362 #define VMOBJDEBUG(x)   x
 363 #define VMOBJDBARGS
 364 #define VMOBJDBFWD
 365
 366 #endif
 367
 368 void VMOBJDEBUG(vm_object_hold)(vm_object_t object VMOBJDBARGS);
 369 int VMOBJDEBUG(vm_object_hold_try)(vm_object_t object VMOBJDBARGS);
 370 void VMOBJDEBUG(vm_object_hold_shared)(vm_object_t object VMOBJDBARGS);
 371 void VMOBJDEBUG(vm_object_drop)(vm_object_t object VMOBJDBARGS);
 372 void VMOBJDEBUG(vm_object_reference_quick)(vm_object_t object VMOBJDBARGS);
 373 void VMOBJDEBUG(vm_object_reference_locked)(vm_object_t object VMOBJDBARGS);
 374 void VMOBJDEBUG(vm_object_deallocate)(vm_object_t object VMOBJDBARGS);
 375 void VMOBJDEBUG(vm_object_deallocate_locked)(vm_object_t object VMOBJDBARGS);
 376
 377 void vm_object_upgrade(vm_object_t);
 378 void vm_object_downgrade(vm_object_t);
 379
 380 #endif                          /* _KERNEL */
 381
 382 #endif                          /* _VM_VM_OBJECT_H_ */