1/* $NetBSD: uvm_map.h,v 1.73 2016/05/25 17:43:58 christos 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#define UVM_EXTRACT_PROT_ALL 0x20 /* set prot to UVM_PROT_ALL */
112
113#endif /* _KERNEL */
114
115#include <sys/rbtree.h>
116#include <sys/pool.h>
117#include <sys/rwlock.h>
118#include <sys/mutex.h>
119#include <sys/condvar.h>
120
121#include <uvm/uvm_anon.h>
122
123/*
124 * Address map entries consist of start and end addresses,
125 * a VM object (or sharing map) and offset into that object,
126 * and user-exported inheritance and protection information.
127 * Also included is control information for virtual copy operations.
128 */
129struct vm_map_entry {
130 struct rb_node rb_node; /* tree information */
131 vsize_t gap; /* free space after */
132 vsize_t maxgap; /* space in subtree */
133 struct vm_map_entry *prev; /* previous entry */
134 struct vm_map_entry *next; /* next entry */
135 vaddr_t start; /* start address */
136 vaddr_t end; /* end address */
137 union {
138 struct uvm_object *uvm_obj; /* uvm object */
139 struct vm_map *sub_map; /* belongs to another map */
140 } object; /* object I point to */
141 voff_t offset; /* offset into object */
142 int etype; /* entry type */
143 vm_prot_t protection; /* protection code */
144 vm_prot_t max_protection; /* maximum protection */
145 vm_inherit_t inheritance; /* inheritance */
146 int wired_count; /* can be paged if == 0 */
147 struct vm_aref aref; /* anonymous overlay */
148 int advice; /* madvise advice */
149 uint32_t map_attrib; /* uvm-external map attributes */
150#define uvm_map_entry_stop_copy flags
151 u_int8_t flags; /* flags */
152
153#define UVM_MAP_KERNEL 0x01 /* kernel map entry */
154#define UVM_MAP_STATIC 0x04 /* special static entries */
155#define UVM_MAP_NOMERGE 0x08 /* 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_WIREFUTURE r/w; may only be set or cleared when
197 * map is write-locked. may be tested
198 * without asserting `flags_lock'.
199 *
200 * VM_MAP_DYING r/o; set when a vmspace is being
201 * destroyed to indicate that updates
202 * to the pmap can be skipped.
203 *
204 * VM_MAP_TOPDOWN r/o; set when the vmspace is
205 * created if the unspecified map
206 * allocations are to be arranged in
207 * a "top down" manner.
208 */
209struct vm_map {
210 struct pmap * pmap; /* Physical map */
211 krwlock_t lock; /* Non-intrsafe lock */
212 struct lwp * busy; /* LWP holding map busy */
213 kmutex_t misc_lock; /* Lock for ref_count, cv */
214 kcondvar_t cv; /* For signalling */
215 int flags; /* flags */
216 struct rb_tree rb_tree; /* Tree for entries */
217 struct vm_map_entry header; /* List of entries */
218 int nentries; /* Number of entries */
219 vsize_t size; /* virtual size */
220 int ref_count; /* Reference count */
221 struct vm_map_entry * hint; /* hint for quick lookups */
222 struct vm_map_entry * first_free; /* First free space hint */
223 unsigned int timestamp; /* Version number */
224};
225
226#if defined(_KERNEL)
227
228#include <sys/callback.h>
229
230#endif /* defined(_KERNEL) */
231
232#define VM_MAP_IS_KERNEL(map) (vm_map_pmap(map) == pmap_kernel())
233
234/* vm_map flags */
235#define VM_MAP_PAGEABLE 0x01 /* ro: entries are pageable */
236#define VM_MAP_WIREFUTURE 0x04 /* rw: wire future mappings */
237#define VM_MAP_DYING 0x20 /* rw: map is being destroyed */
238#define VM_MAP_TOPDOWN 0x40 /* ro: arrange map top-down */
239#define VM_MAP_WANTVA 0x100 /* rw: want va */
240
241#ifdef _KERNEL
242struct uvm_map_args {
243 struct vm_map_entry *uma_prev;
244
245 vaddr_t uma_start;
246 vsize_t uma_size;
247
248 struct uvm_object *uma_uobj;
249 voff_t uma_uoffset;
250
251 uvm_flag_t uma_flags;
252};
253#endif /* _KERNEL */
254
255/*
256 * globals:
257 */
258
259#ifdef _KERNEL
260
261#include <sys/proc.h>
262
263#ifdef PMAP_GROWKERNEL
264extern vaddr_t uvm_maxkaddr;
265#endif
266
267/*
268 * protos: the following prototypes define the interface to vm_map
269 */
270
271void uvm_map_deallocate(struct vm_map *);
272
273int uvm_map_willneed(struct vm_map *, vaddr_t, vaddr_t);
274int uvm_map_clean(struct vm_map *, vaddr_t, vaddr_t, int);
275void uvm_map_clip_start(struct vm_map *, struct vm_map_entry *,
276 vaddr_t);
277void uvm_map_clip_end(struct vm_map *, struct vm_map_entry *,
278 vaddr_t);
279int uvm_map_extract(struct vm_map *, vaddr_t, vsize_t,
280 struct vm_map *, vaddr_t *, int);
281struct vm_map_entry *
282 uvm_map_findspace(struct vm_map *, vaddr_t, vsize_t,
283 vaddr_t *, struct uvm_object *, voff_t, vsize_t, int);
284int uvm_map_inherit(struct vm_map *, vaddr_t, vaddr_t,
285 vm_inherit_t);
286int uvm_map_advice(struct vm_map *, vaddr_t, vaddr_t, int);
287void uvm_map_init(void);
288void uvm_map_init_caches(void);
289bool uvm_map_lookup_entry(struct vm_map *, vaddr_t,
290 struct vm_map_entry **);
291void uvm_map_reference(struct vm_map *);
292int uvm_map_reserve(struct vm_map *, vsize_t, vaddr_t, vsize_t,
293 vaddr_t *, uvm_flag_t);
294void uvm_map_setup(struct vm_map *, vaddr_t, vaddr_t, int);
295int uvm_map_submap(struct vm_map *, vaddr_t, vaddr_t,
296 struct vm_map *);
297void uvm_unmap1(struct vm_map *, vaddr_t, vaddr_t, int);
298#define uvm_unmap(map, s, e) uvm_unmap1((map), (s), (e), 0)
299void uvm_unmap_detach(struct vm_map_entry *,int);
300void uvm_unmap_remove(struct vm_map *, vaddr_t, vaddr_t,
301 struct vm_map_entry **, int);
302
303int uvm_map_prepare(struct vm_map *, vaddr_t, vsize_t,
304 struct uvm_object *, voff_t, vsize_t, uvm_flag_t,
305 struct uvm_map_args *);
306int uvm_map_enter(struct vm_map *, const struct uvm_map_args *,
307 struct vm_map_entry *);
308
309int uvm_mapent_trymerge(struct vm_map *,
310 struct vm_map_entry *, int);
311#define UVM_MERGE_COPYING 1
312
313bool vm_map_starved_p(struct vm_map *);
314
315/*
316 * VM map locking operations.
317 */
318
319bool vm_map_lock_try(struct vm_map *);
320void vm_map_lock(struct vm_map *);
321void vm_map_unlock(struct vm_map *);
322void vm_map_unbusy(struct vm_map *);
323void vm_map_lock_read(struct vm_map *);
324void vm_map_unlock_read(struct vm_map *);
325void vm_map_busy(struct vm_map *);
326bool vm_map_locked_p(struct vm_map *);
327
328void uvm_map_lock_entry(struct vm_map_entry *);
329void uvm_map_unlock_entry(struct vm_map_entry *);
330
331#endif /* _KERNEL */
332
333/*
334 * Functions implemented as macros
335 */
336#define vm_map_min(map) ((map)->header.end)
337#define vm_map_max(map) ((map)->header.start)
338#define vm_map_setmin(map, v) ((map)->header.end = (v))
339#define vm_map_setmax(map, v) ((map)->header.start = (v))
340
341#define vm_map_pmap(map) ((map)->pmap)
342
343#endif /* _UVM_UVM_MAP_H_ */
344