sys/uvm/uvm_map.h

   1 /*      $NetBSD: uvm_map.h,v 1.63 2009/06/10 01:55:33 yamt Exp $        */
   2
   3 /*
   4  * Copyright (c) 1997 Charles D. Cranor and Washington University.
   5  * Copyright (c) 1991, 1993, The Regents of the University of California.
   6  *
   7  * All rights reserved.
   8  *
   9  * This code is derived from software contributed to Berkeley by
  10  * The Mach Operating System project at Carnegie-Mellon University.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. All advertising materials mentioning features or use of this software
  21  *    must display the following acknowledgement:
  22  *      This product includes software developed by Charles D. Cranor,
  23  *      Washington University, the University of California, Berkeley and
  24  *      its contributors.
  25  * 4. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40  *
  41  *      @(#)vm_map.h    8.3 (Berkeley) 3/15/94
  42  * from: Id: uvm_map.h,v 1.1.2.3 1998/02/07 01:16:55 chs Exp
  43  *
  44  *
  45  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
  46  * All rights reserved.
  47  *
  48  * Permission to use, copy, modify and distribute this software and
  49  * its documentation is hereby granted, provided that both the copyright
  50  * notice and this permission notice appear in all copies of the
  51  * software, derivative works or modified versions, and any portions
  52  * thereof, and that both notices appear in supporting documentation.
  53  *
  54  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  55  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
  56  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  57  *
  58  * Carnegie Mellon requests users of this software to return to
  59  *
  60  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  61  *  School of Computer Science
  62  *  Carnegie Mellon University
  63  *  Pittsburgh PA 15213-3890
  64  *
  65  * any improvements or extensions that they make and grant Carnegie the
  66  * rights to redistribute these changes.
  67  */
  68
  69 #ifndef _UVM_UVM_MAP_H_
  70 #define _UVM_UVM_MAP_H_
  71
  72 /*
  73  * uvm_map.h
  74  */
  75
  76 #ifdef _KERNEL
  77
  78 /*
  79  * macros
  80  */
  81
  82 /*
  83  * UVM_MAP_CLIP_START: ensure that the entry begins at or after
  84  * the starting address, if it doesn't we split the entry.
  85  *
  86  * => map must be locked by caller
  87  */
  88
  89 #define UVM_MAP_CLIP_START(MAP,ENTRY,VA,UMR) { \
  90         if ((VA) > (ENTRY)->start) uvm_map_clip_start(MAP,ENTRY,VA,UMR); }
  91
  92 /*
  93  * UVM_MAP_CLIP_END: ensure that the entry ends at or before
  94  *      the ending address, if it does't we split the entry.
  95  *
  96  * => map must be locked by caller
  97  */
  98
  99 #define UVM_MAP_CLIP_END(MAP,ENTRY,VA,UMR) { \
 100         if ((VA) < (ENTRY)->end) uvm_map_clip_end(MAP,ENTRY,VA,UMR); }
 101
 102 /*
 103  * extract flags
 104  */
 105 #define UVM_EXTRACT_REMOVE      0x01    /* remove mapping from old map */
 106 #define UVM_EXTRACT_CONTIG      0x02    /* try to keep it contig */
 107 #define UVM_EXTRACT_QREF        0x04    /* use quick refs */
 108 #define UVM_EXTRACT_FIXPROT     0x08    /* set prot to maxprot as we go */
 109 #define UVM_EXTRACT_RESERVED    0x10    /* caller did uvm_map_reserve() */
 110
 111 #endif /* _KERNEL */
 112
 113 #include <sys/rb.h>
 114 #include <sys/pool.h>
 115 #include <sys/rwlock.h>
 116 #include <sys/mutex.h>
 117 #include <sys/condvar.h>
 118
 119 #include <uvm/uvm_anon.h>
 120
 121 /*
 122  * Address map entries consist of start and end addresses,
 123  * a VM object (or sharing map) and offset into that object,
 124  * and user-exported inheritance and protection information.
 125  * Also included is control information for virtual copy operations.
 126  */
 127 struct vm_map_entry {
 128         struct rb_node          rb_node;        /* tree information */
 129         vsize_t                 gap;            /* free space after */
 130         vsize_t                 maxgap;         /* space in subtree */
 131         struct vm_map_entry     *prev;          /* previous entry */
 132         struct vm_map_entry     *next;          /* next entry */
 133         vaddr_t                 start;          /* start address */
 134         vaddr_t                 end;            /* end address */
 135         union {
 136                 struct uvm_object *uvm_obj;     /* uvm object */
 137                 struct vm_map   *sub_map;       /* belongs to another map */
 138         } object;                               /* object I point to */
 139         voff_t                  offset;         /* offset into object */
 140         int                     etype;          /* entry type */
 141         vm_prot_t               protection;     /* protection code */
 142         vm_prot_t               max_protection; /* maximum protection */
 143         vm_inherit_t            inheritance;    /* inheritance */
 144         int                     wired_count;    /* can be paged if == 0 */
 145         struct vm_aref          aref;           /* anonymous overlay */
 146         int                     advice;         /* madvise advice */
 147 #define uvm_map_entry_stop_copy flags
 148         u_int8_t                flags;          /* flags */
 149
 150 #define UVM_MAP_KERNEL          0x01            /* kernel map entry */
 151 #define UVM_MAP_KMAPENT         0x02            /* contains map entries */
 152 #define UVM_MAP_FIRST           0x04            /* the first special entry */
 153 #define UVM_MAP_QUANTUM         0x08            /* allocated with
 154                                                  * UVM_FLAG_QUANTUM */
 155 #define UVM_MAP_NOMERGE         0x10            /* this entry is not mergable */
 156
 157 };
 158
 159 #define VM_MAPENT_ISWIRED(entry)        ((entry)->wired_count != 0)
 160
 161 /*
 162  *      Maps are doubly-linked lists of map entries, kept sorted
 163  *      by address.  A single hint is provided to start
 164  *      searches again from the last successful search,
 165  *      insertion, or removal.
 166  *
 167  *      LOCKING PROTOCOL NOTES:
 168  *      -----------------------
 169  *
 170  *      VM map locking is a little complicated.  There are both shared
 171  *      and exclusive locks on maps.  However, it is sometimes required
 172  *      to downgrade an exclusive lock to a shared lock, and upgrade to
 173  *      an exclusive lock again (to perform error recovery).  However,
 174  *      another thread *must not* queue itself to receive an exclusive
 175  *      lock while before we upgrade back to exclusive, otherwise the
 176  *      error recovery becomes extremely difficult, if not impossible.
 177  *
 178  *      In order to prevent this scenario, we introduce the notion of
 179  *      a `busy' map.  A `busy' map is read-locked, but other threads
 180  *      attempting to write-lock wait for this flag to clear before
 181  *      entering the lock manager.  A map may only be marked busy
 182  *      when the map is write-locked (and then the map must be downgraded
 183  *      to read-locked), and may only be marked unbusy by the thread
 184  *      which marked it busy (holding *either* a read-lock or a
 185  *      write-lock, the latter being gained by an upgrade).
 186  *
 187  *      Access to the map `flags' member is controlled by the `flags_lock'
 188  *      simple lock.  Note that some flags are static (set once at map
 189  *      creation time, and never changed), and thus require no locking
 190  *      to check those flags.  All flags which are r/w must be set or
 191  *      cleared while the `flags_lock' is asserted.  Additional locking
 192  *      requirements are:
 193  *
 194  *              VM_MAP_PAGEABLE         r/o static flag; no locking required
 195  *
 196  *              VM_MAP_INTRSAFE         r/o static flag; no locking required
 197  *
 198  *              VM_MAP_WIREFUTURE       r/w; may only be set or cleared when
 199  *                                      map is write-locked.  may be tested
 200  *                                      without asserting `flags_lock'.
 201  *
 202  *              VM_MAP_DYING            r/o; set when a vmspace is being
 203  *                                      destroyed to indicate that updates
 204  *                                      to the pmap can be skipped.
 205  *
 206  *              VM_MAP_TOPDOWN          r/o; set when the vmspace is
 207  *                                      created if the unspecified map
 208  *                                      allocations are to be arranged in
 209  *                                      a "top down" manner.
 210  */
 211 struct vm_map {
 212         struct pmap *           pmap;           /* Physical map */
 213         krwlock_t               lock;           /* Non-intrsafe lock */
 214         struct lwp *            busy;           /* LWP holding map busy */
 215         kmutex_t                mutex;          /* INTRSAFE lock */
 216         kmutex_t                misc_lock;      /* Lock for ref_count, cv */
 217         kcondvar_t              cv;             /* For signalling */
 218         int                     flags;          /* flags */
 219         struct rb_tree          rb_tree;        /* Tree for entries */
 220         struct vm_map_entry     header;         /* List of entries */
 221         int                     nentries;       /* Number of entries */
 222         vsize_t                 size;           /* virtual size */
 223         int                     ref_count;      /* Reference count */
 224         struct vm_map_entry *   hint;           /* hint for quick lookups */
 225         struct vm_map_entry *   first_free;     /* First free space hint */
 226         unsigned int            timestamp;      /* Version number */
 227 };
 228
 229 #if defined(_KERNEL)
 230
 231 #include <sys/callback.h>
 232
 233 struct vm_map_kernel {
 234         struct vm_map vmk_map;
 235         LIST_HEAD(, uvm_kmapent_hdr) vmk_kentry_free;
 236                         /* Freelist of map entry */
 237         struct vm_map_entry     *vmk_merged_entries;
 238                         /* Merged entries, kept for later splitting */
 239
 240         struct callback_head vmk_reclaim_callback;
 241 #if !defined(PMAP_MAP_POOLPAGE)
 242         struct pool vmk_vacache; /* kva cache */
 243         struct pool_allocator vmk_vacache_allocator; /* ... and its allocator */
 244 #endif
 245 };
 246 #endif /* defined(_KERNEL) */
 247
 248 #define VM_MAP_IS_KERNEL(map)   (vm_map_pmap(map) == pmap_kernel())
 249
 250 /* vm_map flags */
 251 #define VM_MAP_PAGEABLE         0x01            /* ro: entries are pageable */
 252 #define VM_MAP_INTRSAFE         0x02            /* ro: interrupt safe map */
 253 #define VM_MAP_WIREFUTURE       0x04            /* rw: wire future mappings */
 254 #define VM_MAP_DYING            0x20            /* rw: map is being destroyed */
 255 #define VM_MAP_TOPDOWN          0x40            /* ro: arrange map top-down */
 256 #define VM_MAP_VACACHE          0x80            /* ro: use kva cache */
 257 #define VM_MAP_WANTVA           0x100           /* rw: want va */
 258
 259 #ifdef _KERNEL
 260 struct uvm_mapent_reservation {
 261         struct vm_map_entry *umr_entries[2];
 262         int umr_nentries;
 263 };
 264 #define UMR_EMPTY(umr)          ((umr) == NULL || (umr)->umr_nentries == 0)
 265 #define UMR_GETENTRY(umr)       ((umr)->umr_entries[--(umr)->umr_nentries])
 266 #define UMR_PUTENTRY(umr, ent)  \
 267         (umr)->umr_entries[(umr)->umr_nentries++] = (ent)
 268
 269 struct uvm_map_args {
 270         struct vm_map_entry *uma_prev;
 271
 272         vaddr_t uma_start;
 273         vsize_t uma_size;
 274
 275         struct uvm_object *uma_uobj;
 276         voff_t uma_uoffset;
 277
 278         uvm_flag_t uma_flags;
 279 };
 280 #endif /* _KERNEL */
 281
 282 /*
 283  * globals:
 284  */
 285
 286 #ifdef _KERNEL
 287
 288 #include <sys/proc.h>
 289
 290 #ifdef PMAP_GROWKERNEL
 291 extern vaddr_t  uvm_maxkaddr;
 292 #endif
 293
 294 /*
 295  * protos: the following prototypes define the interface to vm_map
 296  */
 297
 298 void            uvm_map_deallocate(struct vm_map *);
 299
 300 int             uvm_map_willneed(struct vm_map *, vaddr_t, vaddr_t);
 301 int             uvm_map_clean(struct vm_map *, vaddr_t, vaddr_t, int);
 302 void            uvm_map_clip_start(struct vm_map *, struct vm_map_entry *,
 303                     vaddr_t, struct uvm_mapent_reservation *);
 304 void            uvm_map_clip_end(struct vm_map *, struct vm_map_entry *,
 305                     vaddr_t, struct uvm_mapent_reservation *);
 306 struct vm_map   *uvm_map_create(pmap_t, vaddr_t, vaddr_t, int);
 307 int             uvm_map_extract(struct vm_map *, vaddr_t, vsize_t,
 308                     struct vm_map *, vaddr_t *, int);
 309 struct vm_map_entry *
 310                 uvm_map_findspace(struct vm_map *, vaddr_t, vsize_t,
 311                     vaddr_t *, struct uvm_object *, voff_t, vsize_t, int);
 312 int             uvm_map_inherit(struct vm_map *, vaddr_t, vaddr_t,
 313                     vm_inherit_t);
 314 int             uvm_map_advice(struct vm_map *, vaddr_t, vaddr_t, int);
 315 void            uvm_map_init(void);
 316 bool            uvm_map_lookup_entry(struct vm_map *, vaddr_t,
 317                     struct vm_map_entry **);
 318 void            uvm_map_reference(struct vm_map *);
 319 int             uvm_map_reserve(struct vm_map *, vsize_t, vaddr_t, vsize_t,
 320                     vaddr_t *, uvm_flag_t);
 321 void            uvm_map_setup(struct vm_map *, vaddr_t, vaddr_t, int);
 322 void            uvm_map_setup_kernel(struct vm_map_kernel *,
 323                     vaddr_t, vaddr_t, int);
 324 struct vm_map_kernel *
 325                 vm_map_to_kernel(struct vm_map *);
 326 int             uvm_map_submap(struct vm_map *, vaddr_t, vaddr_t,
 327                     struct vm_map *);
 328 void            uvm_unmap1(struct vm_map *, vaddr_t, vaddr_t, int);
 329 #define uvm_unmap(map, s, e)    uvm_unmap1((map), (s), (e), 0)
 330 void            uvm_unmap_detach(struct vm_map_entry *,int);
 331 void            uvm_unmap_remove(struct vm_map *, vaddr_t, vaddr_t,
 332                     struct vm_map_entry **, struct uvm_mapent_reservation *,
 333                     int);
 334
 335 int             uvm_map_prepare(struct vm_map *, vaddr_t, vsize_t,
 336                     struct uvm_object *, voff_t, vsize_t, uvm_flag_t,
 337                     struct uvm_map_args *);
 338 int             uvm_map_enter(struct vm_map *, const struct uvm_map_args *,
 339                     struct vm_map_entry *);
 340
 341 int             uvm_mapent_reserve(struct vm_map *,
 342                     struct uvm_mapent_reservation *, int, int);
 343 void            uvm_mapent_unreserve(struct vm_map *,
 344                     struct uvm_mapent_reservation *);
 345
 346 vsize_t         uvm_mapent_overhead(vsize_t, int);
 347
 348 int             uvm_mapent_trymerge(struct vm_map *,
 349                     struct vm_map_entry *, int);
 350 #define UVM_MERGE_COPYING       1
 351
 352 bool            vm_map_starved_p(struct vm_map *);
 353
 354 /*
 355  * VM map locking operations.
 356  */
 357
 358 bool            vm_map_lock_try(struct vm_map *);
 359 void            vm_map_lock(struct vm_map *);
 360 void            vm_map_unlock(struct vm_map *);
 361 void            vm_map_unbusy(struct vm_map *);
 362 void            vm_map_lock_read(struct vm_map *);
 363 void            vm_map_unlock_read(struct vm_map *);
 364 void            vm_map_busy(struct vm_map *);
 365 bool            vm_map_locked_p(struct vm_map *);
 366
 367 #endif /* _KERNEL */
 368
 369 /*
 370  *      Functions implemented as macros
 371  */
 372 #define         vm_map_min(map)         ((map)->header.end)
 373 #define         vm_map_max(map)         ((map)->header.start)
 374 #define         vm_map_setmin(map, v)   ((map)->header.end = (v))
 375 #define         vm_map_setmax(map, v)   ((map)->header.start = (v))
 376
 377 #define         vm_map_pmap(map)        ((map)->pmap)
 378
 379 #endif /* _UVM_UVM_MAP_H_ */