Home | History | Annotate | Line # | Download | only in uvm
uvm_map.h revision 1.70
      1 /*	$NetBSD: uvm_map.h,v 1.70 2012/01/27 19:48:41 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 (at) 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_KMAPENT		0x02		/* contains map entries */
    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_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 #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_INTRSAFE		0x02		/* ro: interrupt safe map */
    240 #define	VM_MAP_WIREFUTURE	0x04		/* rw: wire future mappings */
    241 #define	VM_MAP_DYING		0x20		/* rw: map is being destroyed */
    242 #define	VM_MAP_TOPDOWN		0x40		/* ro: arrange map top-down */
    243 #define	VM_MAP_WANTVA		0x100		/* rw: want va */
    244 
    245 #ifdef _KERNEL
    246 struct uvm_map_args {
    247 	struct vm_map_entry *uma_prev;
    248 
    249 	vaddr_t uma_start;
    250 	vsize_t uma_size;
    251 
    252 	struct uvm_object *uma_uobj;
    253 	voff_t uma_uoffset;
    254 
    255 	uvm_flag_t uma_flags;
    256 };
    257 #endif /* _KERNEL */
    258 
    259 /*
    260  * globals:
    261  */
    262 
    263 #ifdef _KERNEL
    264 
    265 #include <sys/proc.h>
    266 
    267 #ifdef PMAP_GROWKERNEL
    268 extern vaddr_t	uvm_maxkaddr;
    269 #endif
    270 
    271 /*
    272  * protos: the following prototypes define the interface to vm_map
    273  */
    274 
    275 void		uvm_map_deallocate(struct vm_map *);
    276 
    277 int		uvm_map_willneed(struct vm_map *, vaddr_t, vaddr_t);
    278 int		uvm_map_clean(struct vm_map *, vaddr_t, vaddr_t, int);
    279 void		uvm_map_clip_start(struct vm_map *, struct vm_map_entry *,
    280 		    vaddr_t);
    281 void		uvm_map_clip_end(struct vm_map *, struct vm_map_entry *,
    282 		    vaddr_t);
    283 int		uvm_map_extract(struct vm_map *, vaddr_t, vsize_t,
    284 		    struct vm_map *, vaddr_t *, int);
    285 struct vm_map_entry *
    286 		uvm_map_findspace(struct vm_map *, vaddr_t, vsize_t,
    287 		    vaddr_t *, struct uvm_object *, voff_t, vsize_t, int);
    288 int		uvm_map_inherit(struct vm_map *, vaddr_t, vaddr_t,
    289 		    vm_inherit_t);
    290 int		uvm_map_advice(struct vm_map *, vaddr_t, vaddr_t, int);
    291 void		uvm_map_init(void);
    292 void		uvm_map_init_caches(void);
    293 bool		uvm_map_lookup_entry(struct vm_map *, vaddr_t,
    294 		    struct vm_map_entry **);
    295 void		uvm_map_reference(struct vm_map *);
    296 int		uvm_map_reserve(struct vm_map *, vsize_t, vaddr_t, vsize_t,
    297 		    vaddr_t *, uvm_flag_t);
    298 void		uvm_map_setup(struct vm_map *, vaddr_t, vaddr_t, int);
    299 int		uvm_map_submap(struct vm_map *, vaddr_t, vaddr_t,
    300 		    struct vm_map *);
    301 void		uvm_unmap1(struct vm_map *, vaddr_t, vaddr_t, int);
    302 #define	uvm_unmap(map, s, e)	uvm_unmap1((map), (s), (e), 0)
    303 void		uvm_unmap_detach(struct vm_map_entry *,int);
    304 void		uvm_unmap_remove(struct vm_map *, vaddr_t, vaddr_t,
    305 		    struct vm_map_entry **, int);
    306 
    307 int		uvm_map_prepare(struct vm_map *, vaddr_t, vsize_t,
    308 		    struct uvm_object *, voff_t, vsize_t, uvm_flag_t,
    309 		    struct uvm_map_args *);
    310 int		uvm_map_enter(struct vm_map *, const struct uvm_map_args *,
    311 		    struct vm_map_entry *);
    312 
    313 int		uvm_mapent_trymerge(struct vm_map *,
    314 		    struct vm_map_entry *, int);
    315 #define	UVM_MERGE_COPYING	1
    316 
    317 bool		vm_map_starved_p(struct vm_map *);
    318 
    319 /*
    320  * VM map locking operations.
    321  */
    322 
    323 bool		vm_map_lock_try(struct vm_map *);
    324 void		vm_map_lock(struct vm_map *);
    325 void		vm_map_unlock(struct vm_map *);
    326 void		vm_map_unbusy(struct vm_map *);
    327 void		vm_map_lock_read(struct vm_map *);
    328 void		vm_map_unlock_read(struct vm_map *);
    329 void		vm_map_busy(struct vm_map *);
    330 bool		vm_map_locked_p(struct vm_map *);
    331 
    332 void		uvm_map_lock_entry(struct vm_map_entry *);
    333 void		uvm_map_unlock_entry(struct vm_map_entry *);
    334 
    335 #endif /* _KERNEL */
    336 
    337 /*
    338  *	Functions implemented as macros
    339  */
    340 #define		vm_map_min(map)		((map)->header.end)
    341 #define		vm_map_max(map)		((map)->header.start)
    342 #define		vm_map_setmin(map, v)	((map)->header.end = (v))
    343 #define		vm_map_setmax(map, v)	((map)->header.start = (v))
    344 
    345 #define		vm_map_pmap(map)	((map)->pmap)
    346 
    347 #endif /* _UVM_UVM_MAP_H_ */
    348