xref: /openbsd-src/sys/uvm/uvm_map.h (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: uvm_map.h,v 1.59 2016/09/16 03:39:25 dlg Exp $	*/
2 /*	$NetBSD: uvm_map.h,v 1.24 2001/02/18 21:19:08 chs Exp $	*/
3 
4 /*
5  * Copyright (c) 2011 Ariane van der Steldt <ariane@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  *
19  *
20  * Copyright (c) 1997 Charles D. Cranor and Washington University.
21  * Copyright (c) 1991, 1993, The Regents of the University of California.
22  *
23  * All rights reserved.
24  *
25  * This code is derived from software contributed to Berkeley by
26  * The Mach Operating System project at Carnegie-Mellon University.
27  *
28  * Redistribution and use in source and binary forms, with or without
29  * modification, are permitted provided that the following conditions
30  * are met:
31  * 1. Redistributions of source code must retain the above copyright
32  *    notice, this list of conditions and the following disclaimer.
33  * 2. Redistributions in binary form must reproduce the above copyright
34  *    notice, this list of conditions and the following disclaimer in the
35  *    documentation and/or other materials provided with the distribution.
36  * 3. Neither the name of the University nor the names of its contributors
37  *    may be used to endorse or promote products derived from this software
38  *    without specific prior written permission.
39  *
40  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  *	@(#)vm_map.h    8.3 (Berkeley) 3/15/94
53  * from: Id: uvm_map.h,v 1.1.2.3 1998/02/07 01:16:55 chs Exp
54  *
55  *
56  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
57  * All rights reserved.
58  *
59  * Permission to use, copy, modify and distribute this software and
60  * its documentation is hereby granted, provided that both the copyright
61  * notice and this permission notice appear in all copies of the
62  * software, derivative works or modified versions, and any portions
63  * thereof, and that both notices appear in supporting documentation.
64  *
65  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
66  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
67  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
68  *
69  * Carnegie Mellon requests users of this software to return to
70  *
71  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
72  *  School of Computer Science
73  *  Carnegie Mellon University
74  *  Pittsburgh PA 15213-3890
75  *
76  * any improvements or extensions that they make and grant Carnegie the
77  * rights to redistribute these changes.
78  */
79 
80 #ifndef _UVM_UVM_MAP_H_
81 #define _UVM_UVM_MAP_H_
82 
83 #include <sys/mutex.h>
84 #include <sys/rwlock.h>
85 
86 #ifdef _KERNEL
87 
88 /*
89  * Internal functions.
90  *
91  * Required by clipping macros.
92  */
93 void			 uvm_map_clip_end(struct vm_map*, struct vm_map_entry*,
94 			    vaddr_t);
95 void			 uvm_map_clip_start(struct vm_map*,
96 			    struct vm_map_entry*, vaddr_t);
97 
98 /*
99  * UVM_MAP_CLIP_START: ensure that the entry begins at or after
100  * the starting address, if it doesn't we split the entry.
101  *
102  * => map must be locked by caller
103  */
104 
105 #define UVM_MAP_CLIP_START(_map, _entry, _addr)				\
106 	do {								\
107 		KASSERT((_entry)->end + (_entry)->fspace > (_addr));	\
108 		if ((_entry)->start < (_addr))				\
109 			uvm_map_clip_start((_map), (_entry), (_addr));	\
110 	} while (0)
111 
112 /*
113  * UVM_MAP_CLIP_END: ensure that the entry ends at or before
114  *      the ending address, if it does't we split the entry.
115  *
116  * => map must be locked by caller
117  */
118 
119 #define UVM_MAP_CLIP_END(_map, _entry, _addr)				\
120 	do {								\
121 		KASSERT((_entry)->start < (_addr));			\
122 		if ((_entry)->end > (_addr))				\
123 			uvm_map_clip_end((_map), (_entry), (_addr));	\
124 	} while (0)
125 
126 /*
127  * extract flags
128  */
129 #define UVM_EXTRACT_FIXPROT	0x8	/* set prot to maxprot as we go */
130 
131 #endif /* _KERNEL */
132 
133 #include <uvm/uvm_anon.h>
134 
135 /*
136  * types defined:
137  *
138  *	vm_map_t		the high-level address map data structure.
139  *	vm_map_entry_t		an entry in an address map.
140  *	vm_map_version_t	a timestamp of a map, for use with vm_map_lookup
141  */
142 
143 /*
144  * Objects which live in maps may be either VM objects, or another map
145  * (called a "sharing map") which denotes read-write sharing with other maps.
146  *
147  * XXXCDC: private pager data goes here now
148  */
149 
150 union vm_map_object {
151 	struct uvm_object	*uvm_obj;	/* UVM OBJECT */
152 	struct vm_map		*sub_map;	/* belongs to another map */
153 };
154 
155 /*
156  * Address map entries consist of start and end addresses,
157  * a VM object (or sharing map) and offset into that object,
158  * and user-exported inheritance and protection information.
159  * Also included is control information for virtual copy operations.
160  */
161 struct vm_map_entry {
162 	union {
163 		RBT_ENTRY(vm_map_entry)	addr_entry; /* address tree */
164 		SLIST_ENTRY(vm_map_entry) addr_kentry;
165 	} daddrs;
166 
167 	union {
168 		RBT_ENTRY(vm_map_entry)	rbtree;	/* Link freespace tree. */
169 		TAILQ_ENTRY(vm_map_entry) tailq;/* Link freespace queue. */
170 		TAILQ_ENTRY(vm_map_entry) deadq;/* dead entry queue */
171 	} dfree;
172 
173 #define uvm_map_entry_start_copy start
174 	vaddr_t			start;		/* start address */
175 	vaddr_t			end;		/* end address */
176 
177 	vsize_t			guard;		/* bytes in guard */
178 	vsize_t			fspace;		/* free space */
179 
180 	union vm_map_object	object;		/* object I point to */
181 	voff_t			offset;		/* offset into object */
182 	struct vm_aref		aref;		/* anonymous overlay */
183 
184 	int			etype;		/* entry type */
185 
186 	vm_prot_t		protection;	/* protection code */
187 	vm_prot_t		max_protection;	/* maximum protection */
188 	vm_inherit_t		inheritance;	/* inheritance */
189 
190 	int			wired_count;	/* can be paged if == 0 */
191 	int			advice;		/* madvise advice */
192 #define uvm_map_entry_stop_copy flags
193 	u_int8_t		flags;		/* flags */
194 
195 #define UVM_MAP_STATIC		0x01		/* static map entry */
196 #define UVM_MAP_KMEM		0x02		/* from kmem entry pool */
197 
198 	vsize_t			fspace_augment;	/* max(fspace) in subtree */
199 };
200 
201 #define	VM_MAPENT_ISWIRED(entry)	((entry)->wired_count != 0)
202 
203 TAILQ_HEAD(uvm_map_deadq, vm_map_entry);	/* dead entry queue */
204 RBT_HEAD(uvm_map_addr, vm_map_entry);
205 #ifdef _KERNEL
206 RBT_PROTOTYPE(uvm_map_addr, vm_map_entry, daddrs.addr_entry,
207     uvm_mapentry_addrcmp);
208 #endif
209 
210 /*
211  *	A Map is a rbtree of map entries, kept sorted by address.
212  *	In addition, free space entries are also kept in a rbtree,
213  *	indexed by free size.
214  *
215  *
216  *
217  *	LOCKING PROTOCOL NOTES:
218  *	-----------------------
219  *
220  *	VM map locking is a little complicated.  There are both shared
221  *	and exclusive locks on maps.  However, it is sometimes required
222  *	to downgrade an exclusive lock to a shared lock, and upgrade to
223  *	an exclusive lock again (to perform error recovery).  However,
224  *	another thread *must not* queue itself to receive an exclusive
225  *	lock while before we upgrade back to exclusive, otherwise the
226  *	error recovery becomes extremely difficult, if not impossible.
227  *
228  *	In order to prevent this scenario, we introduce the notion of
229  *	a `busy' map.  A `busy' map is read-locked, but other threads
230  *	attempting to write-lock wait for this flag to clear before
231  *	entering the lock manager.  A map may only be marked busy
232  *	when the map is write-locked (and then the map must be downgraded
233  *	to read-locked), and may only be marked unbusy by the thread
234  *	which marked it busy (holding *either* a read-lock or a
235  *	write-lock, the latter being gained by an upgrade).
236  *
237  *	Access to the map `flags' member is controlled by the `flags_lock'
238  *	simple lock.  Note that some flags are static (set once at map
239  *	creation time, and never changed), and thus require no locking
240  *	to check those flags.  All flags which are r/w must be set or
241  *	cleared while the `flags_lock' is asserted.  Additional locking
242  *	requirements are:
243  *
244  *		VM_MAP_PAGEABLE		r/o static flag; no locking required
245  *
246  *		VM_MAP_INTRSAFE		r/o static flag; no locking required
247  *
248  *		VM_MAP_WIREFUTURE	r/w; may only be set or cleared when
249  *					map is write-locked.  may be tested
250  *					without asserting `flags_lock'.
251  *
252  *		VM_MAP_BUSY		r/w; may only be set when map is
253  *					write-locked, may only be cleared by
254  *					thread which set it, map read-locked
255  *					or write-locked.  must be tested
256  *					while `flags_lock' is asserted.
257  *
258  *		VM_MAP_WANTLOCK		r/w; may only be set when the map
259  *					is busy, and thread is attempting
260  *					to write-lock.  must be tested
261  *					while `flags_lock' is asserted.
262  *
263  *		VM_MAP_GUARDPAGES	r/o; must be specified at map
264  *					initialization time.
265  *					If set, guards will appear between
266  *					automatic allocations.
267  *					No locking required.
268  *
269  *		VM_MAP_ISVMSPACE	r/o; set by uvmspace_alloc.
270  *					Signifies that this map is a vmspace.
271  *					(The implementation treats all maps
272  *					without this bit as kernel maps.)
273  *					No locking required.
274  *
275  *
276  * All automatic allocations (uvm_map without MAP_FIXED) will allocate
277  * from vm_map.free.
278  * If that allocation fails:
279  * - vmspace maps will spill over into vm_map.bfree,
280  * - all other maps will call uvm_map_kmem_grow() to increase the arena.
281  *
282  * vmspace maps have their data, brk() and stack arenas automatically
283  * updated when uvm_map() is invoked without MAP_FIXED.
284  * The spill over arena (vm_map.bfree) will contain the space in the brk()
285  * and stack ranges.
286  * Kernel maps never have a bfree arena and this tree will always be empty.
287  *
288  *
289  * read_locks and write_locks are used in lock debugging code.
290  */
291 struct vm_map {
292 	struct pmap *		pmap;		/* Physical map */
293 	struct rwlock		lock;		/* Lock for map data */
294 	struct mutex		mtx;
295 
296 	struct uvm_map_addr	addr;		/* Entry tree, by addr */
297 
298 	vsize_t			size;		/* virtual size */
299 	int			ref_count;	/* Reference count */
300 	int			flags;		/* flags */
301 	struct mutex		flags_lock;	/* flags lock */
302 	unsigned int		timestamp;	/* Version number */
303 
304 	vaddr_t			min_offset;	/* First address in map. */
305 	vaddr_t			max_offset;	/* Last address in map. */
306 
307 	/*
308 	 * Allocation overflow regions.
309 	 */
310 	vaddr_t			b_start;	/* Start for brk() alloc. */
311 	vaddr_t			b_end;		/* End for brk() alloc. */
312 	vaddr_t			s_start;	/* Start for stack alloc. */
313 	vaddr_t			s_end;		/* End for stack alloc. */
314 
315 	/*
316 	 * Special address selectors.
317 	 *
318 	 * The uaddr_exe mapping is used if:
319 	 * - protX is selected
320 	 * - the pointer is not NULL
321 	 *
322 	 * If uaddr_exe is not used, the other mappings are checked in
323 	 * order of appearance.
324 	 * If a hint is given, the selection will only be used if the hint
325 	 * falls in the range described by the mapping.
326 	 *
327 	 * The states are pointers because:
328 	 * - they may not all be in use
329 	 * - the struct size for different schemes is variable
330 	 *
331 	 * The uaddr_brk_stack selector will select addresses that are in
332 	 * the brk/stack area of the map.
333 	 */
334 	struct uvm_addr_state	*uaddr_exe;	/* Executable selector. */
335 	struct uvm_addr_state	*uaddr_any[4];	/* More selectors. */
336 	struct uvm_addr_state	*uaddr_brk_stack; /* Brk/stack selector. */
337 };
338 
339 /* vm_map flags */
340 #define	VM_MAP_PAGEABLE		0x01		/* ro: entries are pageable */
341 #define	VM_MAP_INTRSAFE		0x02		/* ro: interrupt safe map */
342 #define	VM_MAP_WIREFUTURE	0x04		/* rw: wire future mappings */
343 #define	VM_MAP_BUSY		0x08		/* rw: map is busy */
344 #define	VM_MAP_WANTLOCK		0x10		/* rw: want to write-lock */
345 #define VM_MAP_GUARDPAGES	0x20		/* rw: add guard pgs to map */
346 #define VM_MAP_ISVMSPACE	0x40		/* ro: map is a vmspace */
347 
348 /* XXX: number of kernel maps and entries to statically allocate */
349 
350 #if !defined(MAX_KMAPENT)
351 #define	MAX_KMAPENT	1024	/* Sufficient to make it to the scheduler. */
352 #endif	/* !defined MAX_KMAPENT */
353 
354 #ifdef _KERNEL
355 #define	vm_map_modflags(map, set, clear)				\
356 do {									\
357 	mtx_enter(&(map)->flags_lock);					\
358 	(map)->flags = ((map)->flags | (set)) & ~(clear);		\
359 	mtx_leave(&(map)->flags_lock);					\
360 } while (0)
361 #endif /* _KERNEL */
362 
363 /*
364  *	Interrupt-safe maps must also be kept on a special list,
365  *	to assist uvm_fault() in avoiding locking problems.
366  */
367 struct vm_map_intrsafe {
368 	struct vm_map	vmi_map;
369 	LIST_ENTRY(vm_map_intrsafe) vmi_list;
370 };
371 
372 /*
373  * globals:
374  */
375 
376 #ifdef _KERNEL
377 
378 extern vaddr_t	uvm_maxkaddr;
379 
380 /*
381  * protos: the following prototypes define the interface to vm_map
382  */
383 
384 void		uvm_map_deallocate(vm_map_t);
385 
386 int		uvm_map_clean(vm_map_t, vaddr_t, vaddr_t, int);
387 vm_map_t	uvm_map_create(pmap_t, vaddr_t, vaddr_t, int);
388 int		uvm_map_extract(struct vm_map*, vaddr_t, vsize_t, vaddr_t*,
389 		    int);
390 vaddr_t		uvm_map_pie(vaddr_t);
391 vaddr_t		uvm_map_hint(struct vmspace *, vm_prot_t, vaddr_t, vaddr_t);
392 int		uvm_map_inherit(vm_map_t, vaddr_t, vaddr_t, vm_inherit_t);
393 int		uvm_map_advice(vm_map_t, vaddr_t, vaddr_t, int);
394 void		uvm_map_init(void);
395 boolean_t	uvm_map_lookup_entry(vm_map_t, vaddr_t, vm_map_entry_t *);
396 int		uvm_map_replace(vm_map_t, vaddr_t, vaddr_t,
397 		    vm_map_entry_t, int);
398 int		uvm_map_reserve(vm_map_t, vsize_t, vaddr_t, vsize_t,
399 		    vaddr_t *);
400 void		uvm_map_setup(vm_map_t, vaddr_t, vaddr_t, int);
401 int		uvm_map_submap(vm_map_t, vaddr_t, vaddr_t, vm_map_t);
402 void		uvm_unmap(vm_map_t, vaddr_t, vaddr_t);
403 void		uvm_map_set_uaddr(struct vm_map*, struct uvm_addr_state**,
404 		    struct uvm_addr_state*);
405 int		uvm_map_mquery(struct vm_map*, vaddr_t*, vsize_t, voff_t, int);
406 
407 void		uvm_unmap_detach(struct uvm_map_deadq*, int);
408 void		uvm_unmap_remove(struct vm_map*, vaddr_t, vaddr_t,
409 		    struct uvm_map_deadq*, boolean_t, boolean_t);
410 
411 struct kinfo_vmentry;
412 
413 int		uvm_map_fill_vmmap(struct vm_map *, struct kinfo_vmentry *,
414 		    size_t *);
415 
416 #endif /* _KERNEL */
417 
418 /*
419  * VM map locking operations:
420  *
421  *	These operations perform locking on the data portion of the
422  *	map.
423  *
424  *	vm_map_lock_try: try to lock a map, failing if it is already locked.
425  *
426  *	vm_map_lock: acquire an exclusive (write) lock on a map.
427  *
428  *	vm_map_lock_read: acquire a shared (read) lock on a map.
429  *
430  *	vm_map_unlock: release an exclusive lock on a map.
431  *
432  *	vm_map_unlock_read: release a shared lock on a map.
433  *
434  *	vm_map_downgrade: downgrade an exclusive lock to a shared lock.
435  *
436  *	vm_map_upgrade: upgrade a shared lock to an exclusive lock.
437  *
438  *	vm_map_busy: mark a map as busy.
439  *
440  *	vm_map_unbusy: clear busy status on a map.
441  *
442  */
443 
444 #ifdef _KERNEL
445 /*
446  * XXX: clean up later
447  * Half the kernel seems to depend on them being included here.
448  */
449 #include <sys/time.h>
450 #include <sys/systm.h>  /* for panic() */
451 
452 boolean_t	vm_map_lock_try_ln(struct vm_map*, char*, int);
453 void		vm_map_lock_ln(struct vm_map*, char*, int);
454 void		vm_map_lock_read_ln(struct vm_map*, char*, int);
455 void		vm_map_unlock_ln(struct vm_map*, char*, int);
456 void		vm_map_unlock_read_ln(struct vm_map*, char*, int);
457 void		vm_map_downgrade_ln(struct vm_map*, char*, int);
458 void		vm_map_upgrade_ln(struct vm_map*, char*, int);
459 void		vm_map_busy_ln(struct vm_map*, char*, int);
460 void		vm_map_unbusy_ln(struct vm_map*, char*, int);
461 
462 #ifdef DIAGNOSTIC
463 #define vm_map_lock_try(map)	vm_map_lock_try_ln(map, __FILE__, __LINE__)
464 #define vm_map_lock(map)	vm_map_lock_ln(map, __FILE__, __LINE__)
465 #define vm_map_lock_read(map)	vm_map_lock_read_ln(map, __FILE__, __LINE__)
466 #define vm_map_unlock(map)	vm_map_unlock_ln(map, __FILE__, __LINE__)
467 #define vm_map_unlock_read(map)	vm_map_unlock_read_ln(map, __FILE__, __LINE__)
468 #define vm_map_downgrade(map)	vm_map_downgrade_ln(map, __FILE__, __LINE__)
469 #define vm_map_upgrade(map)	vm_map_upgrade_ln(map, __FILE__, __LINE__)
470 #define vm_map_busy(map)	vm_map_busy_ln(map, __FILE__, __LINE__)
471 #define vm_map_unbusy(map)	vm_map_unbusy_ln(map, __FILE__, __LINE__)
472 #else
473 #define vm_map_lock_try(map)	vm_map_lock_try_ln(map, NULL, 0)
474 #define vm_map_lock(map)	vm_map_lock_ln(map, NULL, 0)
475 #define vm_map_lock_read(map)	vm_map_lock_read_ln(map, NULL, 0)
476 #define vm_map_unlock(map)	vm_map_unlock_ln(map, NULL, 0)
477 #define vm_map_unlock_read(map)	vm_map_unlock_read_ln(map, NULL, 0)
478 #define vm_map_downgrade(map)	vm_map_downgrade_ln(map, NULL, 0)
479 #define vm_map_upgrade(map)	vm_map_upgrade_ln(map, NULL, 0)
480 #define vm_map_busy(map)	vm_map_busy_ln(map, NULL, 0)
481 #define vm_map_unbusy(map)	vm_map_unbusy_ln(map, NULL, 0)
482 #endif
483 
484 #endif /* _KERNEL */
485 
486 /*
487  *	Functions implemented as macros
488  */
489 #define		vm_map_min(map)		((map)->min_offset)
490 #define		vm_map_max(map)		((map)->max_offset)
491 #define		vm_map_pmap(map)	((map)->pmap)
492 
493 #endif /* _UVM_UVM_MAP_H_ */
494