sys/uvm/uvm_map.h

   1 /*      $NetBSD: uvm_map.h,v 1.72 2012/10/29 16:00:05 para 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. 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  *      @(#)vm_map.h    8.3 (Berkeley) 3/15/94
  37  * from: Id: uvm_map.h,v 1.1.2.3 1998/02/07 01:16:55 chs Exp
  38  *
  39  *
  40  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
  41  * All rights reserved.
  42  *
  43  * Permission to use, copy, modify and distribute this software and
  44  * its documentation is hereby granted, provided that both the copyright
  45  * notice and this permission notice appear in all copies of the
  46  * software, derivative works or modified versions, and any portions
  47  * thereof, and that both notices appear in supporting documentation.
  48  *
  49  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  50  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
  51  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  52  *
  53  * Carnegie Mellon requests users of this software to return to
  54  *
  55  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  56  *  School of Computer Science
  57  *  Carnegie Mellon University
  58  *  Pittsburgh PA 15213-3890
  59  *
  60  * any improvements or extensions that they make and grant Carnegie the
  61  * rights to redistribute these changes.
  62  */
  63
  64 #ifndef _UVM_UVM_MAP_H_
  65 #define _UVM_UVM_MAP_H_
  66
  67 /*
  68  * uvm_map.h
  69  */
  70
  71 #ifdef _KERNEL
  72
  73 /*
  74  * macros
  75  */
  76
  77 /*
  78  * UVM_MAP_CLIP_START: ensure that the entry begins at or after
  79  * the starting address, if it doesn't we split the entry.
  80  *
  81  * => map must be locked by caller
  82  */
  83
  84 #define UVM_MAP_CLIP_START(MAP,ENTRY,VA) { \
  85         if ((VA) > (ENTRY)->start && (VA) < (ENTRY)->end) { \
  86                 uvm_map_clip_start(MAP,ENTRY,VA); \
  87         } \
  88 }
  89
  90 /*
  91  * UVM_MAP_CLIP_END: ensure that the entry ends at or before
  92  *      the ending address, if it does't we split the entry.
  93  *
  94  * => map must be locked by caller
  95  */
  96
  97 #define UVM_MAP_CLIP_END(MAP,ENTRY,VA) { \
  98         if ((VA) > (ENTRY)->start && (VA) < (ENTRY)->end) { \
  99                 uvm_map_clip_end(MAP,ENTRY,VA); \
 100         } \
 101 }
 102
 103 /*
 104  * extract flags
 105  */
 106 #define UVM_EXTRACT_REMOVE      0x01    /* remove mapping from old map */
 107 #define UVM_EXTRACT_CONTIG      0x02    /* try to keep it contig */
 108 #define UVM_EXTRACT_QREF        0x04    /* use quick refs */
 109 #define UVM_EXTRACT_FIXPROT     0x08    /* set prot to maxprot as we go */
 110 #define UVM_EXTRACT_RESERVED    0x10    /* caller did uvm_map_reserve() */
 111
 112 #endif /* _KERNEL */
 113
 114 #include <sys/rbtree.h>
 115 #include <sys/pool.h>
 116 #include <sys/rwlock.h>
 117 #include <sys/mutex.h>
 118 #include <sys/condvar.h>
 119
 120 #include <uvm/uvm_anon.h>
 121
 122 /*
 123  * Address map entries consist of start and end addresses,
 124  * a VM object (or sharing map) and offset into that object,
 125  * and user-exported inheritance and protection information.
 126  * Also included is control information for virtual copy operations.
 127  */
 128 struct vm_map_entry {
 129         struct rb_node          rb_node;        /* tree information */
 130         vsize_t                 gap;            /* free space after */
 131         vsize_t                 maxgap;         /* space in subtree */
 132         struct vm_map_entry     *prev;          /* previous entry */
 133         struct vm_map_entry     *next;          /* next entry */
 134         vaddr_t                 start;          /* start address */
 135         vaddr_t                 end;            /* end address */
 136         union {
 137                 struct uvm_object *uvm_obj;     /* uvm object */
 138                 struct vm_map   *sub_map;       /* belongs to another map */
 139         } object;                               /* object I point to */
 140         voff_t                  offset;         /* offset into object */
 141         int                     etype;          /* entry type */
 142         vm_prot_t               protection;     /* protection code */
 143         vm_prot_t               max_protection; /* maximum protection */
 144         vm_inherit_t            inheritance;    /* inheritance */
 145         int                     wired_count;    /* can be paged if == 0 */
 146         struct vm_aref          aref;           /* anonymous overlay */
 147         int                     advice;         /* madvise advice */
 148         uint32_t                map_attrib;     /* uvm-external map attributes */
 149 #define uvm_map_entry_stop_copy flags
 150         u_int8_t                flags;          /* flags */
 151
 152 #define UVM_MAP_KERNEL          0x01            /* kernel map entry */
 153 #define UVM_MAP_STATIC          0x04            /* special static entries */
 154 #define UVM_MAP_NOMERGE         0x08            /* this entry is not mergable */
 155
 156 };
 157
 158 #define VM_MAPENT_ISWIRED(entry)        ((entry)->wired_count != 0)
 159
 160 /*
 161  *      Maps are doubly-linked lists of map entries, kept sorted
 162  *      by address.  A single hint is provided to start
 163  *      searches again from the last successful search,
 164  *      insertion, or removal.
 165  *
 166  *      LOCKING PROTOCOL NOTES:
 167  *      -----------------------
 168  *
 169  *      VM map locking is a little complicated.  There are both shared
 170  *      and exclusive locks on maps.  However, it is sometimes required
 171  *      to downgrade an exclusive lock to a shared lock, and upgrade to
 172  *      an exclusive lock again (to perform error recovery).  However,
 173  *      another thread *must not* queue itself to receive an exclusive
 174  *      lock while before we upgrade back to exclusive, otherwise the
 175  *      error recovery becomes extremely difficult, if not impossible.
 176  *
 177  *      In order to prevent this scenario, we introduce the notion of
 178  *      a `busy' map.  A `busy' map is read-locked, but other threads
 179  *      attempting to write-lock wait for this flag to clear before
 180  *      entering the lock manager.  A map may only be marked busy
 181  *      when the map is write-locked (and then the map must be downgraded
 182  *      to read-locked), and may only be marked unbusy by the thread
 183  *      which marked it busy (holding *either* a read-lock or a
 184  *      write-lock, the latter being gained by an upgrade).
 185  *
 186  *      Access to the map `flags' member is controlled by the `flags_lock'
 187  *      simple lock.  Note that some flags are static (set once at map
 188  *      creation time, and never changed), and thus require no locking
 189  *      to check those flags.  All flags which are r/w must be set or
 190  *      cleared while the `flags_lock' is asserted.  Additional locking
 191  *      requirements are:
 192  *
 193  *              VM_MAP_PAGEABLE         r/o static flag; no locking required
 194  *
 195  *              VM_MAP_WIREFUTURE       r/w; may only be set or cleared when
 196  *                                      map is write-locked.  may be tested
 197  *                                      without asserting `flags_lock'.
 198  *
 199  *              VM_MAP_DYING            r/o; set when a vmspace is being
 200  *                                      destroyed to indicate that updates
 201  *                                      to the pmap can be skipped.
 202  *
 203  *              VM_MAP_TOPDOWN          r/o; set when the vmspace is
 204  *                                      created if the unspecified map
 205  *                                      allocations are to be arranged in
 206  *                                      a "top down" manner.
 207  */
 208 struct vm_map {
 209         struct pmap *           pmap;           /* Physical map */
 210         krwlock_t               lock;           /* Non-intrsafe lock */
 211         struct lwp *            busy;           /* LWP holding map busy */
 212         kmutex_t                misc_lock;      /* Lock for ref_count, cv */
 213         kcondvar_t              cv;             /* For signalling */
 214         int                     flags;          /* flags */
 215         struct rb_tree          rb_tree;        /* Tree for entries */
 216         struct vm_map_entry     header;         /* List of entries */
 217         int                     nentries;       /* Number of entries */
 218         vsize_t                 size;           /* virtual size */
 219         int                     ref_count;      /* Reference count */
 220         struct vm_map_entry *   hint;           /* hint for quick lookups */
 221         struct vm_map_entry *   first_free;     /* First free space hint */
 222         unsigned int            timestamp;      /* Version number */
 223 };
 224
 225 #if defined(_KERNEL)
 226
 227 #include <sys/callback.h>
 228
 229 #endif /* defined(_KERNEL) */
 230
 231 #define VM_MAP_IS_KERNEL(map)   (vm_map_pmap(map) == pmap_kernel())
 232
 233 /* vm_map flags */
 234 #define VM_MAP_PAGEABLE         0x01            /* ro: entries are pageable */
 235 #define VM_MAP_WIREFUTURE       0x04            /* rw: wire future mappings */
 236 #define VM_MAP_DYING            0x20            /* rw: map is being destroyed */
 237 #define VM_MAP_TOPDOWN          0x40            /* ro: arrange map top-down */
 238 #define VM_MAP_WANTVA           0x100           /* rw: want va */
 239
 240 #ifdef _KERNEL
 241 struct uvm_map_args {
 242         struct vm_map_entry *uma_prev;
 243
 244         vaddr_t uma_start;
 245         vsize_t uma_size;
 246
 247         struct uvm_object *uma_uobj;
 248         voff_t uma_uoffset;
 249
 250         uvm_flag_t uma_flags;
 251 };
 252 #endif /* _KERNEL */
 253
 254 /*
 255  * globals:
 256  */
 257
 258 #ifdef _KERNEL
 259
 260 #include <sys/proc.h>
 261
 262 #ifdef PMAP_GROWKERNEL
 263 extern vaddr_t  uvm_maxkaddr;
 264 #endif
 265
 266 /*
 267  * protos: the following prototypes define the interface to vm_map
 268  */
 269
 270 void            uvm_map_deallocate(struct vm_map *);
 271
 272 int             uvm_map_willneed(struct vm_map *, vaddr_t, vaddr_t);
 273 int             uvm_map_clean(struct vm_map *, vaddr_t, vaddr_t, int);
 274 void            uvm_map_clip_start(struct vm_map *, struct vm_map_entry *,
 275                     vaddr_t);
 276 void            uvm_map_clip_end(struct vm_map *, struct vm_map_entry *,
 277                     vaddr_t);
 278 int             uvm_map_extract(struct vm_map *, vaddr_t, vsize_t,
 279                     struct vm_map *, vaddr_t *, int);
 280 struct vm_map_entry *
 281                 uvm_map_findspace(struct vm_map *, vaddr_t, vsize_t,
 282                     vaddr_t *, struct uvm_object *, voff_t, vsize_t, int);
 283 int             uvm_map_inherit(struct vm_map *, vaddr_t, vaddr_t,
 284                     vm_inherit_t);
 285 int             uvm_map_advice(struct vm_map *, vaddr_t, vaddr_t, int);
 286 void            uvm_map_init(void);
 287 void            uvm_map_init_caches(void);
 288 bool            uvm_map_lookup_entry(struct vm_map *, vaddr_t,
 289                     struct vm_map_entry **);
 290 void            uvm_map_reference(struct vm_map *);
 291 int             uvm_map_reserve(struct vm_map *, vsize_t, vaddr_t, vsize_t,
 292                     vaddr_t *, uvm_flag_t);
 293 void            uvm_map_setup(struct vm_map *, vaddr_t, vaddr_t, int);
 294 int             uvm_map_submap(struct vm_map *, vaddr_t, vaddr_t,
 295                     struct vm_map *);
 296 void            uvm_unmap1(struct vm_map *, vaddr_t, vaddr_t, int);
 297 #define uvm_unmap(map, s, e)    uvm_unmap1((map), (s), (e), 0)
 298 void            uvm_unmap_detach(struct vm_map_entry *,int);
 299 void            uvm_unmap_remove(struct vm_map *, vaddr_t, vaddr_t,
 300                     struct vm_map_entry **, int);
 301
 302 int             uvm_map_prepare(struct vm_map *, vaddr_t, vsize_t,
 303                     struct uvm_object *, voff_t, vsize_t, uvm_flag_t,
 304                     struct uvm_map_args *);
 305 int             uvm_map_enter(struct vm_map *, const struct uvm_map_args *,
 306                     struct vm_map_entry *);
 307
 308 int             uvm_mapent_trymerge(struct vm_map *,
 309                     struct vm_map_entry *, int);
 310 #define UVM_MERGE_COPYING       1
 311
 312 bool            vm_map_starved_p(struct vm_map *);
 313
 314 /*
 315  * VM map locking operations.
 316  */
 317
 318 bool            vm_map_lock_try(struct vm_map *);
 319 void            vm_map_lock(struct vm_map *);
 320 void            vm_map_unlock(struct vm_map *);
 321 void            vm_map_unbusy(struct vm_map *);
 322 void            vm_map_lock_read(struct vm_map *);
 323 void            vm_map_unlock_read(struct vm_map *);
 324 void            vm_map_busy(struct vm_map *);
 325 bool            vm_map_locked_p(struct vm_map *);
 326
 327 void            uvm_map_lock_entry(struct vm_map_entry *);
 328 void            uvm_map_unlock_entry(struct vm_map_entry *);
 329
 330 #endif /* _KERNEL */
 331
 332 /*
 333  *      Functions implemented as macros
 334  */
 335 #define         vm_map_min(map)         ((map)->header.end)
 336 #define         vm_map_max(map)         ((map)->header.start)
 337 #define         vm_map_setmin(map, v)   ((map)->header.end = (v))
 338 #define         vm_map_setmax(map, v)   ((map)->header.start = (v))
 339
 340 #define         vm_map_pmap(map)        ((map)->pmap)
 341
 342 #endif /* _UVM_UVM_MAP_H_ */