master
1/* $NetBSD: uvm_map.h,v 1.80 2020/05/26 00:50:53 kamil 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 *
129 * At runtime this is aligned on a cacheline boundary, with fields
130 * used during fault processing to do RB tree lookup clustered at
131 * the beginning.
132 */
133struct vm_map_entry {
134 struct rb_node rb_node; /* tree information */
135 vaddr_t start; /* start address */
136 vaddr_t end; /* end address */
137 vsize_t gap; /* free space after */
138 vsize_t maxgap; /* space in subtree */
139 struct vm_map_entry *prev; /* previous entry */
140 struct vm_map_entry *next; /* next entry */
141 union {
142 struct uvm_object *uvm_obj; /* uvm object */
143 struct vm_map *sub_map; /* belongs to another map */
144 } object; /* object I point to */
145 voff_t offset; /* offset into object */
146 uint8_t etype; /* entry type */
147 uint8_t flags; /* flags */
148 uint8_t advice; /* madvise advice */
149 uint8_t unused; /* unused */
150 vm_prot_t protection; /* protection code */
151 vm_prot_t max_protection; /* maximum protection */
152 vm_inherit_t inheritance; /* inheritance */
153 int wired_count; /* can be paged if == 0 */
154 struct vm_aref aref; /* anonymous overlay */
155};
156
157/* flags */
158#define UVM_MAP_KERNEL 0x01 /* kernel map entry */
159#define UVM_MAP_STATIC 0x04 /* special static entries */
160#define UVM_MAP_NOMERGE 0x08 /* this entry is not mergable */
161
162#define VM_MAPENT_ISWIRED(entry) ((entry)->wired_count != 0)
163
164/*
165 * Maps are doubly-linked lists of map entries, kept sorted
166 * by address. A single hint is provided to start
167 * searches again from the last successful search,
168 * insertion, or removal.
169 *
170 * LOCKING PROTOCOL NOTES:
171 * -----------------------
172 *
173 * VM map locking is a little complicated. There are both shared
174 * and exclusive locks on maps. However, it is sometimes required
175 * to downgrade an exclusive lock to a shared lock, and upgrade to
176 * an exclusive lock again (to perform error recovery). However,
177 * another thread *must not* queue itself to receive an exclusive
178 * lock while before we upgrade back to exclusive, otherwise the
179 * error recovery becomes extremely difficult, if not impossible.
180 *
181 * In order to prevent this scenario, we introduce the notion of
182 * a `busy' map. A `busy' map is read-locked, but other threads
183 * attempting to write-lock wait for this flag to clear before
184 * entering the lock manager. A map may only be marked busy
185 * when the map is write-locked (and then the map must be downgraded
186 * to read-locked), and may only be marked unbusy by the thread
187 * which marked it busy (holding *either* a read-lock or a
188 * write-lock, the latter being gained by an upgrade).
189 *
190 * Access to the map `flags' member is controlled by the `flags_lock'
191 * simple lock. Note that some flags are static (set once at map
192 * creation time, and never changed), and thus require no locking
193 * to check those flags. All flags which are r/w must be set or
194 * cleared while the `flags_lock' is asserted. Additional locking
195 * requirements are:
196 *
197 * VM_MAP_PAGEABLE r/o static flag; no locking required
198 *
199 * VM_MAP_WIREFUTURE r/w; may only be set or cleared when
200 * map is write-locked. may be tested
201 * without asserting `flags_lock'.
202 *
203 * VM_MAP_DYING r/o; set when a vmspace is being
204 * destroyed to indicate that updates
205 * to the pmap can be skipped.
206 *
207 * VM_MAP_TOPDOWN r/o; set when the vmspace is
208 * created if the unspecified map
209 * allocations are to be arranged in
210 * a "top down" manner.
211 */
212struct vm_map {
213 struct pmap * pmap; /* Physical map */
214 krwlock_t lock; /* Non-intrsafe lock */
215 struct lwp * busy; /* LWP holding map busy */
216 kmutex_t misc_lock; /* Lock for cv, busy */
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 volatile 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#endif /* defined(_KERNEL) */
234
235#define VM_MAP_IS_KERNEL(map) (vm_map_pmap(map) == pmap_kernel())
236
237/* vm_map flags */
238#define VM_MAP_PAGEABLE 0x01 /* ro: entries are pageable */
239#define VM_MAP_WIREFUTURE 0x04 /* rw: wire future mappings */
240#define VM_MAP_DYING 0x20 /* rw: map is being destroyed */
241#define VM_MAP_TOPDOWN 0x40 /* ro: arrange map top-down */
242#define VM_MAP_WANTVA 0x100 /* rw: want va */
243
244#define VM_MAP_BITS "\177\020\
245b\0PAGEABLE\0\
246b\2WIREFUTURE\0\
247b\5DYING\0\
248b\6TOPDOWN\0\
249b\10WANTVA\0"
250
251#ifdef _KERNEL
252struct uvm_map_args {
253 struct vm_map_entry *uma_prev;
254
255 vaddr_t uma_start;
256 vsize_t uma_size;
257
258 struct uvm_object *uma_uobj;
259 voff_t uma_uoffset;
260
261 uvm_flag_t uma_flags;
262};
263#endif /* _KERNEL */
264
265/*
266 * globals:
267 */
268
269#ifdef _KERNEL
270
271#include <sys/proc.h>
272
273#ifdef PMAP_GROWKERNEL
274extern vaddr_t uvm_maxkaddr;
275#endif
276
277/*
278 * protos: the following prototypes define the interface to vm_map
279 */
280
281void uvm_map_deallocate(struct vm_map *);
282
283int uvm_map_willneed(struct vm_map *, vaddr_t, vaddr_t);
284int uvm_map_clean(struct vm_map *, vaddr_t, vaddr_t, int);
285void uvm_map_clip_start(struct vm_map *, struct vm_map_entry *,
286 vaddr_t);
287void uvm_map_clip_end(struct vm_map *, struct vm_map_entry *,
288 vaddr_t);
289int uvm_map_extract(struct vm_map *, vaddr_t, vsize_t,
290 struct vm_map *, vaddr_t *, int);
291struct vm_map_entry *
292 uvm_map_findspace(struct vm_map *, vaddr_t, vsize_t,
293 vaddr_t *, struct uvm_object *, voff_t, vsize_t, int);
294int uvm_map_inherit(struct vm_map *, vaddr_t, vaddr_t,
295 vm_inherit_t);
296int uvm_map_advice(struct vm_map *, vaddr_t, vaddr_t, int);
297void uvm_map_init(void);
298void uvm_map_init_caches(void);
299bool uvm_map_lookup_entry(struct vm_map *, vaddr_t,
300 struct vm_map_entry **);
301void uvm_map_reference(struct vm_map *);
302int uvm_map_reserve(struct vm_map *, vsize_t, vaddr_t, vsize_t,
303 vaddr_t *, uvm_flag_t);
304void uvm_map_setup(struct vm_map *, vaddr_t, vaddr_t, int);
305int uvm_map_submap(struct vm_map *, vaddr_t, vaddr_t,
306 struct vm_map *);
307void uvm_unmap1(struct vm_map *, vaddr_t, vaddr_t, int);
308#define uvm_unmap(map, s, e) uvm_unmap1((map), (s), (e), 0)
309void uvm_unmap_detach(struct vm_map_entry *,int);
310void uvm_unmap_remove(struct vm_map *, vaddr_t, vaddr_t,
311 struct vm_map_entry **, int);
312
313int uvm_map_prepare(struct vm_map *, vaddr_t, vsize_t,
314 struct uvm_object *, voff_t, vsize_t, uvm_flag_t,
315 struct uvm_map_args *);
316int uvm_map_enter(struct vm_map *, const struct uvm_map_args *,
317 struct vm_map_entry *);
318
319int uvm_mapent_trymerge(struct vm_map *,
320 struct vm_map_entry *, int);
321#define UVM_MERGE_COPYING 1
322
323/*
324 * VM map locking operations.
325 */
326
327bool vm_map_lock_try(struct vm_map *);
328void vm_map_lock(struct vm_map *);
329void vm_map_unlock(struct vm_map *);
330void vm_map_unbusy(struct vm_map *);
331void vm_map_lock_read(struct vm_map *);
332void vm_map_unlock_read(struct vm_map *);
333void vm_map_busy(struct vm_map *);
334bool vm_map_locked_p(struct vm_map *);
335
336void uvm_map_lock_entry(struct vm_map_entry *, krw_t);
337void uvm_map_unlock_entry(struct vm_map_entry *);
338
339#endif /* _KERNEL */
340
341/*
342 * Functions implemented as macros
343 */
344#define vm_map_min(map) ((map)->header.end)
345#define vm_map_max(map) ((map)->header.start)
346#define vm_map_setmin(map, v) ((map)->header.end = (v))
347#define vm_map_setmax(map, v) ((map)->header.start = (v))
348
349#define vm_map_pmap(map) ((map)->pmap)
350
351#endif /* _UVM_UVM_MAP_H_ */