1 /* $NetBSD: uvm_map.h,v 1.75 2019/08/01 02:28:55 riastradh 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 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 #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_STATIC 0x04 /* special static entries */ 154 #define UVM_MAP_NOMERGE 0x08 /* this entry is not mergable */ 155 156 }; 157 158 #define VM_MAPENT_ISWIRED(entry) ((entry)->wired_count != 0) 159 160 /* 161 * Maps are doubly-linked lists of map entries, kept sorted 162 * by address. A single hint is provided to start 163 * searches again from the last successful search, 164 * insertion, or removal. 165 * 166 * LOCKING PROTOCOL NOTES: 167 * ----------------------- 168 * 169 * VM map locking is a little complicated. There are both shared 170 * and exclusive locks on maps. However, it is sometimes required 171 * to downgrade an exclusive lock to a shared lock, and upgrade to 172 * an exclusive lock again (to perform error recovery). However, 173 * another thread *must not* queue itself to receive an exclusive 174 * lock while before we upgrade back to exclusive, otherwise the 175 * error recovery becomes extremely difficult, if not impossible. 176 * 177 * In order to prevent this scenario, we introduce the notion of 178 * a `busy' map. A `busy' map is read-locked, but other threads 179 * attempting to write-lock wait for this flag to clear before 180 * entering the lock manager. A map may only be marked busy 181 * when the map is write-locked (and then the map must be downgraded 182 * to read-locked), and may only be marked unbusy by the thread 183 * which marked it busy (holding *either* a read-lock or a 184 * write-lock, the latter being gained by an upgrade). 185 * 186 * Access to the map `flags' member is controlled by the `flags_lock' 187 * simple lock. Note that some flags are static (set once at map 188 * creation time, and never changed), and thus require no locking 189 * to check those flags. All flags which are r/w must be set or 190 * cleared while the `flags_lock' is asserted. Additional locking 191 * requirements are: 192 * 193 * VM_MAP_PAGEABLE r/o static flag; no locking required 194 * 195 * VM_MAP_WIREFUTURE r/w; may only be set or cleared when 196 * map is write-locked. may be tested 197 * without asserting `flags_lock'. 198 * 199 * VM_MAP_DYING r/o; set when a vmspace is being 200 * destroyed to indicate that updates 201 * to the pmap can be skipped. 202 * 203 * VM_MAP_TOPDOWN r/o; set when the vmspace is 204 * created if the unspecified map 205 * allocations are to be arranged in 206 * a "top down" manner. 207 */ 208 struct vm_map { 209 struct pmap * pmap; /* Physical map */ 210 krwlock_t lock; /* Non-intrsafe lock */ 211 struct lwp * busy; /* LWP holding map busy */ 212 kmutex_t misc_lock; /* Lock for ref_count, cv */ 213 kcondvar_t cv; /* For signalling */ 214 int flags; /* flags */ 215 struct rb_tree rb_tree; /* Tree for entries */ 216 struct vm_map_entry header; /* List of entries */ 217 int nentries; /* Number of entries */ 218 vsize_t size; /* virtual size */ 219 int ref_count; /* Reference count */ 220 struct vm_map_entry * hint; /* hint for quick lookups */ 221 struct vm_map_entry * first_free; /* First free space hint */ 222 unsigned int timestamp; /* Version number */ 223 }; 224 225 #if defined(_KERNEL) 226 227 #include <sys/callback.h> 228 229 #endif /* defined(_KERNEL) */ 230 231 #define VM_MAP_IS_KERNEL(map) (vm_map_pmap(map) == pmap_kernel()) 232 233 /* vm_map flags */ 234 #define VM_MAP_PAGEABLE 0x01 /* ro: entries are pageable */ 235 #define VM_MAP_WIREFUTURE 0x04 /* rw: wire future mappings */ 236 #define VM_MAP_DYING 0x20 /* rw: map is being destroyed */ 237 #define VM_MAP_TOPDOWN 0x40 /* ro: arrange map top-down */ 238 #define VM_MAP_WANTVA 0x100 /* rw: want va */ 239 240 #define VM_MAP_BITS "\177\020\ 241 b\0PAGEABLE\0\ 242 b\2WIREFUTURE\0\ 243 b\5DYING\0\ 244 b\6TOPDOWN\0\ 245 b\10WANTVA\0" 246 247 #ifdef _KERNEL 248 struct uvm_map_args { 249 struct vm_map_entry *uma_prev; 250 251 vaddr_t uma_start; 252 vsize_t uma_size; 253 254 struct uvm_object *uma_uobj; 255 voff_t uma_uoffset; 256 257 uvm_flag_t uma_flags; 258 }; 259 #endif /* _KERNEL */ 260 261 /* 262 * globals: 263 */ 264 265 #ifdef _KERNEL 266 267 #include <sys/proc.h> 268 269 #ifdef PMAP_GROWKERNEL 270 extern vaddr_t uvm_maxkaddr; 271 #endif 272 273 /* 274 * protos: the following prototypes define the interface to vm_map 275 */ 276 277 void uvm_map_deallocate(struct vm_map *); 278 279 int uvm_map_willneed(struct vm_map *, vaddr_t, vaddr_t); 280 int uvm_map_clean(struct vm_map *, vaddr_t, vaddr_t, int); 281 void uvm_map_clip_start(struct vm_map *, struct vm_map_entry *, 282 vaddr_t); 283 void uvm_map_clip_end(struct vm_map *, struct vm_map_entry *, 284 vaddr_t); 285 int uvm_map_extract(struct vm_map *, vaddr_t, vsize_t, 286 struct vm_map *, vaddr_t *, int); 287 struct vm_map_entry * 288 uvm_map_findspace(struct vm_map *, vaddr_t, vsize_t, 289 vaddr_t *, struct uvm_object *, voff_t, vsize_t, int); 290 int uvm_map_inherit(struct vm_map *, vaddr_t, vaddr_t, 291 vm_inherit_t); 292 int uvm_map_advice(struct vm_map *, vaddr_t, vaddr_t, int); 293 void uvm_map_init(void); 294 void uvm_map_init_caches(void); 295 bool uvm_map_lookup_entry(struct vm_map *, vaddr_t, 296 struct vm_map_entry **); 297 void uvm_map_reference(struct vm_map *); 298 int uvm_map_reserve(struct vm_map *, vsize_t, vaddr_t, vsize_t, 299 vaddr_t *, uvm_flag_t); 300 void uvm_map_setup(struct vm_map *, vaddr_t, vaddr_t, int); 301 int uvm_map_submap(struct vm_map *, vaddr_t, vaddr_t, 302 struct vm_map *); 303 void uvm_unmap1(struct vm_map *, vaddr_t, vaddr_t, int); 304 #define uvm_unmap(map, s, e) uvm_unmap1((map), (s), (e), 0) 305 void uvm_unmap_detach(struct vm_map_entry *,int); 306 void uvm_unmap_remove(struct vm_map *, vaddr_t, vaddr_t, 307 struct vm_map_entry **, int); 308 309 int uvm_map_prepare(struct vm_map *, vaddr_t, vsize_t, 310 struct uvm_object *, voff_t, vsize_t, uvm_flag_t, 311 struct uvm_map_args *); 312 int uvm_map_enter(struct vm_map *, const struct uvm_map_args *, 313 struct vm_map_entry *); 314 315 int uvm_mapent_trymerge(struct vm_map *, 316 struct vm_map_entry *, int); 317 #define UVM_MERGE_COPYING 1 318 319 bool vm_map_starved_p(struct vm_map *); 320 321 /* 322 * VM map locking operations. 323 */ 324 325 bool vm_map_lock_try(struct vm_map *); 326 void vm_map_lock(struct vm_map *); 327 void vm_map_unlock(struct vm_map *); 328 void vm_map_unbusy(struct vm_map *); 329 void vm_map_lock_read(struct vm_map *); 330 void vm_map_unlock_read(struct vm_map *); 331 void vm_map_busy(struct vm_map *); 332 bool vm_map_locked_p(struct vm_map *); 333 334 void uvm_map_lock_entry(struct vm_map_entry *); 335 void uvm_map_unlock_entry(struct vm_map_entry *); 336 337 #endif /* _KERNEL */ 338 339 /* 340 * Functions implemented as macros 341 */ 342 #define vm_map_min(map) ((map)->header.end) 343 #define vm_map_max(map) ((map)->header.start) 344 #define vm_map_setmin(map, v) ((map)->header.end = (v)) 345 #define vm_map_setmax(map, v) ((map)->header.start = (v)) 346 347 #define vm_map_pmap(map) ((map)->pmap) 348 349 #endif /* _UVM_UVM_MAP_H_ */ 350