uvm_map.h revision 1.73
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 (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 #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 struct 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 */ 209 struct 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 242 struct 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 264 extern vaddr_t uvm_maxkaddr; 265 #endif 266 267 /* 268 * protos: the following prototypes define the interface to vm_map 269 */ 270 271 void uvm_map_deallocate(struct vm_map *); 272 273 int uvm_map_willneed(struct vm_map *, vaddr_t, vaddr_t); 274 int uvm_map_clean(struct vm_map *, vaddr_t, vaddr_t, int); 275 void uvm_map_clip_start(struct vm_map *, struct vm_map_entry *, 276 vaddr_t); 277 void uvm_map_clip_end(struct vm_map *, struct vm_map_entry *, 278 vaddr_t); 279 int uvm_map_extract(struct vm_map *, vaddr_t, vsize_t, 280 struct vm_map *, vaddr_t *, int); 281 struct 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); 284 int uvm_map_inherit(struct vm_map *, vaddr_t, vaddr_t, 285 vm_inherit_t); 286 int uvm_map_advice(struct vm_map *, vaddr_t, vaddr_t, int); 287 void uvm_map_init(void); 288 void uvm_map_init_caches(void); 289 bool uvm_map_lookup_entry(struct vm_map *, vaddr_t, 290 struct vm_map_entry **); 291 void uvm_map_reference(struct vm_map *); 292 int uvm_map_reserve(struct vm_map *, vsize_t, vaddr_t, vsize_t, 293 vaddr_t *, uvm_flag_t); 294 void uvm_map_setup(struct vm_map *, vaddr_t, vaddr_t, int); 295 int uvm_map_submap(struct vm_map *, vaddr_t, vaddr_t, 296 struct vm_map *); 297 void uvm_unmap1(struct vm_map *, vaddr_t, vaddr_t, int); 298 #define uvm_unmap(map, s, e) uvm_unmap1((map), (s), (e), 0) 299 void uvm_unmap_detach(struct vm_map_entry *,int); 300 void uvm_unmap_remove(struct vm_map *, vaddr_t, vaddr_t, 301 struct vm_map_entry **, int); 302 303 int 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 *); 306 int uvm_map_enter(struct vm_map *, const struct uvm_map_args *, 307 struct vm_map_entry *); 308 309 int uvm_mapent_trymerge(struct vm_map *, 310 struct vm_map_entry *, int); 311 #define UVM_MERGE_COPYING 1 312 313 bool vm_map_starved_p(struct vm_map *); 314 315 /* 316 * VM map locking operations. 317 */ 318 319 bool vm_map_lock_try(struct vm_map *); 320 void vm_map_lock(struct vm_map *); 321 void vm_map_unlock(struct vm_map *); 322 void vm_map_unbusy(struct vm_map *); 323 void vm_map_lock_read(struct vm_map *); 324 void vm_map_unlock_read(struct vm_map *); 325 void vm_map_busy(struct vm_map *); 326 bool vm_map_locked_p(struct vm_map *); 327 328 void uvm_map_lock_entry(struct vm_map_entry *); 329 void 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
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