1 /* $NetBSD: uvm_page.h,v 1.30 2001/07/25 23:05:04 thorpej 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. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by Charles D. Cranor, 23 * Washington University, the University of California, Berkeley and 24 * its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)vm_page.h 7.3 (Berkeley) 4/21/91 42 * from: Id: uvm_page.h,v 1.1.2.6 1998/02/04 02:31:42 chuck Exp 43 * 44 * 45 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 46 * All rights reserved. 47 * 48 * Permission to use, copy, modify and distribute this software and 49 * its documentation is hereby granted, provided that both the copyright 50 * notice and this permission notice appear in all copies of the 51 * software, derivative works or modified versions, and any portions 52 * thereof, and that both notices appear in supporting documentation. 53 * 54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 55 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 57 * 58 * Carnegie Mellon requests users of this software to return to 59 * 60 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 61 * School of Computer Science 62 * Carnegie Mellon University 63 * Pittsburgh PA 15213-3890 64 * 65 * any improvements or extensions that they make and grant Carnegie the 66 * rights to redistribute these changes. 67 */ 68 69 #ifndef _UVM_UVM_PAGE_H_ 70 #define _UVM_UVM_PAGE_H_ 71 72 /* 73 * uvm_page.h 74 */ 75 76 /* 77 * Resident memory system definitions. 78 */ 79 80 /* 81 * Management of resident (logical) pages. 82 * 83 * A small structure is kept for each resident 84 * page, indexed by page number. Each structure 85 * is an element of several lists: 86 * 87 * A hash table bucket used to quickly 88 * perform object/offset lookups 89 * 90 * A list of all pages for a given object, 91 * so they can be quickly deactivated at 92 * time of deallocation. 93 * 94 * An ordered list of pages due for pageout. 95 * 96 * In addition, the structure contains the object 97 * and offset to which this page belongs (for pageout), 98 * and sundry status bits. 99 * 100 * Fields in this structure are locked either by the lock on the 101 * object that the page belongs to (O) or by the lock on the page 102 * queues (P) [or both]. 103 */ 104 105 /* 106 * locking note: the mach version of this data structure had bit 107 * fields for the flags, and the bit fields were divided into two 108 * items (depending on who locked what). some time, in BSD, the bit 109 * fields were dumped and all the flags were lumped into one short. 110 * that is fine for a single threaded uniprocessor OS, but bad if you 111 * want to actual make use of locking (simple_lock's). so, we've 112 * separated things back out again. 113 * 114 * note the page structure has no lock of its own. 115 */ 116 117 #include <uvm/uvm_extern.h> 118 #include <uvm/uvm_pglist.h> 119 120 struct vm_page { 121 TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO 122 * queue or free list (P) */ 123 TAILQ_ENTRY(vm_page) hashq; /* hash table links (O)*/ 124 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O)*/ 125 126 struct vm_anon *uanon; /* anon (O,P) */ 127 struct uvm_object *uobject; /* object (O,P) */ 128 voff_t offset; /* offset into object (O,P) */ 129 130 u_int flags: 16, /* object flags [O] */ 131 version: 16; /* version count [O] */ 132 133 u_int wire_count: 16, /* wired down map refs [P] */ 134 pqflags: 8, /* page queue flags [P] */ 135 : 8; 136 137 u_int loan_count; /* number of active loans 138 * to read: [O or P] 139 * to modify: [O _and_ P] */ 140 paddr_t phys_addr; /* physical address of page */ 141 142 #ifdef __HAVE_VM_PAGE_MD 143 struct vm_page_md mdpage; /* pmap-specific data */ 144 #endif 145 146 #if defined(UVM_PAGE_TRKOWN) 147 /* debugging fields to track page ownership */ 148 pid_t owner; /* proc that set PG_BUSY */ 149 char *owner_tag; /* why it was set busy */ 150 #endif 151 }; 152 153 /* 154 * These are the flags defined for vm_page. 155 */ 156 157 /* 158 * locking rules: 159 * PG_ ==> locked by object lock 160 * PQ_ ==> lock by page queue lock 161 * PQ_FREE is locked by free queue lock and is mutex with all other PQs 162 * 163 * PG_ZERO is used to indicate that a page has been pre-zero'd. This flag 164 * is only set when the page is on no queues, and is cleared when the page 165 * is placed on the free list. 166 */ 167 168 #define PG_BUSY 0x0001 /* page is locked */ 169 #define PG_WANTED 0x0002 /* someone is waiting for page */ 170 #define PG_TABLED 0x0004 /* page is in VP table */ 171 #define PG_CLEAN 0x0008 /* page has not been modified */ 172 #define PG_CLEANCHK 0x0010 /* clean bit has been checked */ 173 #define PG_RELEASED 0x0020 /* page released while paging */ 174 #define PG_FAKE 0x0040 /* page is not yet initialized */ 175 #define PG_RDONLY 0x0080 /* page must be mapped read-only */ 176 #define PG_ZERO 0x0100 /* page is pre-zero'd */ 177 178 #define PG_PAGER1 0x1000 /* pager-specific flag */ 179 180 #define PQ_FREE 0x01 /* page is on free list */ 181 #define PQ_INACTIVE 0x02 /* page is in inactive list */ 182 #define PQ_ACTIVE 0x04 /* page is in active list */ 183 #define PQ_ANON 0x10 /* page is part of an anon, rather 184 than an uvm_object */ 185 #define PQ_AOBJ 0x20 /* page is part of an anonymous 186 uvm_object */ 187 #define PQ_SWAPBACKED (PQ_ANON|PQ_AOBJ) 188 189 /* 190 * physical memory layout structure 191 * 192 * MD vmparam.h must #define: 193 * VM_PHYSEG_MAX = max number of physical memory segments we support 194 * (if this is "1" then we revert to a "contig" case) 195 * VM_PHYSSEG_STRAT: memory sort/search options (for VM_PHYSEG_MAX > 1) 196 * - VM_PSTRAT_RANDOM: linear search (random order) 197 * - VM_PSTRAT_BSEARCH: binary search (sorted by address) 198 * - VM_PSTRAT_BIGFIRST: linear search (sorted by largest segment first) 199 * - others? 200 * XXXCDC: eventually we should purge all left-over global variables... 201 */ 202 #define VM_PSTRAT_RANDOM 1 203 #define VM_PSTRAT_BSEARCH 2 204 #define VM_PSTRAT_BIGFIRST 3 205 206 /* 207 * vm_physmemseg: describes one segment of physical memory 208 */ 209 struct vm_physseg { 210 paddr_t start; /* PF# of first page in segment */ 211 paddr_t end; /* (PF# of last page in segment) + 1 */ 212 paddr_t avail_start; /* PF# of first free page in segment */ 213 paddr_t avail_end; /* (PF# of last free page in segment) +1 */ 214 int free_list; /* which free list they belong on */ 215 struct vm_page *pgs; /* vm_page structures (from start) */ 216 struct vm_page *lastpg; /* vm_page structure for end */ 217 #ifdef __HAVE_PMAP_PHYSSEG 218 struct pmap_physseg pmseg; /* pmap specific (MD) data */ 219 #endif 220 }; 221 222 #ifdef _KERNEL 223 224 /* 225 * globals 226 */ 227 228 extern boolean_t vm_page_zero_enable; 229 230 /* 231 * Each pageable resident page falls into one of three lists: 232 * 233 * free 234 * Available for allocation now. 235 * inactive 236 * Not referenced in any map, but still has an 237 * object/offset-page mapping, and may be dirty. 238 * This is the list of pages that should be 239 * paged out next. 240 * active 241 * A list of pages which have been placed in 242 * at least one physical map. This list is 243 * ordered, in LRU-like fashion. 244 */ 245 246 extern struct pglist vm_page_queue_free; /* memory free queue */ 247 extern struct pglist vm_page_queue_active; /* active memory queue */ 248 extern struct pglist vm_page_queue_inactive; /* inactive memory queue */ 249 250 /* 251 * physical memory config is stored in vm_physmem. 252 */ 253 254 extern struct vm_physseg vm_physmem[VM_PHYSSEG_MAX]; 255 extern int vm_nphysseg; 256 257 /* 258 * handle inline options 259 */ 260 261 #ifdef UVM_PAGE_INLINE 262 #define PAGE_INLINE static __inline 263 #else 264 #define PAGE_INLINE /* nothing */ 265 #endif /* UVM_PAGE_INLINE */ 266 267 /* 268 * prototypes: the following prototypes define the interface to pages 269 */ 270 271 void uvm_page_init __P((vaddr_t *, vaddr_t *)); 272 #if defined(UVM_PAGE_TRKOWN) 273 void uvm_page_own __P((struct vm_page *, char *)); 274 #endif 275 #if !defined(PMAP_STEAL_MEMORY) 276 boolean_t uvm_page_physget __P((paddr_t *)); 277 #endif 278 void uvm_page_rehash __P((void)); 279 void uvm_page_recolor __P((int)); 280 void uvm_pageidlezero __P((void)); 281 282 PAGE_INLINE int uvm_lock_fpageq __P((void)); 283 PAGE_INLINE void uvm_unlock_fpageq __P((int)); 284 285 PAGE_INLINE void uvm_pageactivate __P((struct vm_page *)); 286 vaddr_t uvm_pageboot_alloc __P((vsize_t)); 287 PAGE_INLINE void uvm_pagecopy __P((struct vm_page *, struct vm_page *)); 288 PAGE_INLINE void uvm_pagedeactivate __P((struct vm_page *)); 289 void uvm_pagefree __P((struct vm_page *)); 290 void uvm_page_unbusy __P((struct vm_page **, int)); 291 PAGE_INLINE struct vm_page *uvm_pagelookup __P((struct uvm_object *, voff_t)); 292 PAGE_INLINE void uvm_pageunwire __P((struct vm_page *)); 293 PAGE_INLINE void uvm_pagewait __P((struct vm_page *, int)); 294 PAGE_INLINE void uvm_pagewake __P((struct vm_page *)); 295 PAGE_INLINE void uvm_pagewire __P((struct vm_page *)); 296 PAGE_INLINE void uvm_pagezero __P((struct vm_page *)); 297 298 PAGE_INLINE int uvm_page_lookup_freelist __P((struct vm_page *)); 299 300 static struct vm_page *PHYS_TO_VM_PAGE __P((paddr_t)); 301 static int vm_physseg_find __P((paddr_t, int *)); 302 303 /* 304 * macros 305 */ 306 307 #define uvm_lock_pageq() simple_lock(&uvm.pageqlock) 308 #define uvm_unlock_pageq() simple_unlock(&uvm.pageqlock) 309 310 #define uvm_pagehash(obj,off) \ 311 (((unsigned long)obj+(unsigned long)atop(off)) & uvm.page_hashmask) 312 313 #define UVM_PAGEZERO_TARGET (uvmexp.free) 314 315 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 316 317 /* 318 * Compute the page color bucket for a given page. 319 */ 320 #define VM_PGCOLOR_BUCKET(pg) \ 321 (atop(VM_PAGE_TO_PHYS((pg))) & uvmexp.colormask) 322 323 /* 324 * when VM_PHYSSEG_MAX is 1, we can simplify these functions 325 */ 326 327 /* 328 * vm_physseg_find: find vm_physseg structure that belongs to a PA 329 */ 330 static __inline int 331 vm_physseg_find(pframe, offp) 332 paddr_t pframe; 333 int *offp; 334 { 335 #if VM_PHYSSEG_MAX == 1 336 337 /* 'contig' case */ 338 if (pframe >= vm_physmem[0].start && pframe < vm_physmem[0].end) { 339 if (offp) 340 *offp = pframe - vm_physmem[0].start; 341 return(0); 342 } 343 return(-1); 344 345 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 346 /* binary search for it */ 347 int start, len, try; 348 349 /* 350 * if try is too large (thus target is less than than try) we reduce 351 * the length to trunc(len/2) [i.e. everything smaller than "try"] 352 * 353 * if the try is too small (thus target is greater than try) then 354 * we set the new start to be (try + 1). this means we need to 355 * reduce the length to (round(len/2) - 1). 356 * 357 * note "adjust" below which takes advantage of the fact that 358 * (round(len/2) - 1) == trunc((len - 1) / 2) 359 * for any value of len we may have 360 */ 361 362 for (start = 0, len = vm_nphysseg ; len != 0 ; len = len / 2) { 363 try = start + (len / 2); /* try in the middle */ 364 365 /* start past our try? */ 366 if (pframe >= vm_physmem[try].start) { 367 /* was try correct? */ 368 if (pframe < vm_physmem[try].end) { 369 if (offp) 370 *offp = pframe - vm_physmem[try].start; 371 return(try); /* got it */ 372 } 373 start = try + 1; /* next time, start here */ 374 len--; /* "adjust" */ 375 } else { 376 /* 377 * pframe before try, just reduce length of 378 * region, done in "for" loop 379 */ 380 } 381 } 382 return(-1); 383 384 #else 385 /* linear search for it */ 386 int lcv; 387 388 for (lcv = 0; lcv < vm_nphysseg; lcv++) { 389 if (pframe >= vm_physmem[lcv].start && 390 pframe < vm_physmem[lcv].end) { 391 if (offp) 392 *offp = pframe - vm_physmem[lcv].start; 393 return(lcv); /* got it */ 394 } 395 } 396 return(-1); 397 398 #endif 399 } 400 401 402 /* 403 * IS_VM_PHYSADDR: only used my mips/pmax/pica trap/pmap. 404 */ 405 406 #define IS_VM_PHYSADDR(PA) (vm_physseg_find(atop(PA), NULL) != -1) 407 408 /* 409 * PHYS_TO_VM_PAGE: find vm_page for a PA. used by MI code to get vm_pages 410 * back from an I/O mapping (ugh!). used in some MD code as well. 411 */ 412 static __inline struct vm_page * 413 PHYS_TO_VM_PAGE(pa) 414 paddr_t pa; 415 { 416 paddr_t pf = atop(pa); 417 int off; 418 int psi; 419 420 psi = vm_physseg_find(pf, &off); 421 if (psi != -1) 422 return(&vm_physmem[psi].pgs[off]); 423 return(NULL); 424 } 425 426 #define VM_PAGE_IS_FREE(entry) ((entry)->pqflags & PQ_FREE) 427 428 #endif /* _KERNEL */ 429 430 #endif /* _UVM_UVM_PAGE_H_ */ 431