1 /* $NetBSD: uvm_page.h,v 1.55 2008/06/04 15:06:04 ad 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 red-black tree rooted with the containing 88 * object is used to quickly perform object+ 89 * offset lookups 90 * 91 * A list of all pages for a given object, 92 * so they can be quickly deactivated at 93 * time of deallocation. 94 * 95 * An ordered list of pages due for pageout. 96 * 97 * In addition, the structure contains the object 98 * and offset to which this page belongs (for pageout), 99 * and sundry status bits. 100 * 101 * Fields in this structure are locked either by the lock on the 102 * object that the page belongs to (O) or by the lock on the page 103 * queues (P) [or both]. 104 */ 105 106 /* 107 * locking note: the mach version of this data structure had bit 108 * fields for the flags, and the bit fields were divided into two 109 * items (depending on who locked what). some time, in BSD, the bit 110 * fields were dumped and all the flags were lumped into one short. 111 * that is fine for a single threaded uniprocessor OS, but bad if you 112 * want to actual make use of locking. so, we've separated things 113 * back out again. 114 * 115 * note the page structure has no lock of its own. 116 */ 117 118 #include <uvm/uvm_extern.h> 119 #include <uvm/uvm_pglist.h> 120 121 #include <sys/rb.h> 122 123 struct vm_page { 124 struct rb_node rb_node; /* tree of pages in obj (O) */ 125 126 union { 127 TAILQ_ENTRY(vm_page) queue; 128 LIST_ENTRY(vm_page) list; 129 } pageq; /* queue info for FIFO 130 * queue or free list (P) */ 131 union { 132 TAILQ_ENTRY(vm_page) queue; 133 LIST_ENTRY(vm_page) list; 134 } listq; /* pages in same object (O)*/ 135 136 struct vm_anon *uanon; /* anon (O,P) */ 137 struct uvm_object *uobject; /* object (O,P) */ 138 voff_t offset; /* offset into object (O,P) */ 139 uint16_t flags; /* object flags [O] */ 140 uint16_t loan_count; /* number of active loans 141 * to read: [O or P] 142 * to modify: [O _and_ P] */ 143 uint16_t wire_count; /* wired down map refs [P] */ 144 uint16_t pqflags; /* page queue flags [P] */ 145 paddr_t phys_addr; /* physical address of page */ 146 147 #ifdef __HAVE_VM_PAGE_MD 148 struct vm_page_md mdpage; /* pmap-specific data */ 149 #endif 150 151 #if defined(UVM_PAGE_TRKOWN) 152 /* debugging fields to track page ownership */ 153 pid_t owner; /* proc that set PG_BUSY */ 154 lwpid_t lowner; /* lwp that set PG_BUSY */ 155 const char *owner_tag; /* why it was set busy */ 156 #endif 157 }; 158 159 /* 160 * These are the flags defined for vm_page. 161 */ 162 163 /* 164 * locking rules: 165 * PG_ ==> locked by object lock 166 * PQ_ ==> lock by page queue lock 167 * PQ_FREE is locked by free queue lock and is mutex with all other PQs 168 * 169 * PG_ZERO is used to indicate that a page has been pre-zero'd. This flag 170 * is only set when the page is on no queues, and is cleared when the page 171 * is placed on the free list. 172 */ 173 174 #define PG_BUSY 0x0001 /* page is locked */ 175 #define PG_WANTED 0x0002 /* someone is waiting for page */ 176 #define PG_TABLED 0x0004 /* page is in VP table */ 177 #define PG_CLEAN 0x0008 /* page has not been modified */ 178 #define PG_PAGEOUT 0x0010 /* page to be freed for pagedaemon */ 179 #define PG_RELEASED 0x0020 /* page to be freed when unbusied */ 180 #define PG_FAKE 0x0040 /* page is not yet initialized */ 181 #define PG_RDONLY 0x0080 /* page must be mapped read-only */ 182 #define PG_ZERO 0x0100 /* page is pre-zero'd */ 183 184 #define PG_PAGER1 0x1000 /* pager-specific flag */ 185 186 #define UVM_PGFLAGBITS \ 187 "\20\1BUSY\2WANTED\3TABLED\4CLEAN\5PAGEOUT\6RELEASED\7FAKE\10RDONLY" \ 188 "\11ZERO\15PAGER1" 189 190 #define PQ_FREE 0x0001 /* page is on free list */ 191 #define PQ_ANON 0x0002 /* page is part of an anon, rather 192 than an uvm_object */ 193 #define PQ_AOBJ 0x0004 /* page is part of an anonymous 194 uvm_object */ 195 #define PQ_SWAPBACKED (PQ_ANON|PQ_AOBJ) 196 #define PQ_READAHEAD 0x0008 /* read-ahead but has not been "hit" yet */ 197 198 #define PQ_PRIVATE1 0x0100 199 #define PQ_PRIVATE2 0x0200 200 #define PQ_PRIVATE3 0x0400 201 #define PQ_PRIVATE4 0x0800 202 #define PQ_PRIVATE5 0x1000 203 #define PQ_PRIVATE6 0x2000 204 #define PQ_PRIVATE7 0x4000 205 #define PQ_PRIVATE8 0x8000 206 207 #define UVM_PQFLAGBITS \ 208 "\20\1FREE\2ANON\3AOBJ\4READAHEAD" \ 209 "\11PRIVATE1\12PRIVATE2\13PRIVATE3\14PRIVATE4" \ 210 "\15PRIVATE5\16PRIVATE6\17PRIVATE7\20PRIVATE8" 211 212 /* 213 * physical memory layout structure 214 * 215 * MD vmparam.h must #define: 216 * VM_PHYSEG_MAX = max number of physical memory segments we support 217 * (if this is "1" then we revert to a "contig" case) 218 * VM_PHYSSEG_STRAT: memory sort/search options (for VM_PHYSEG_MAX > 1) 219 * - VM_PSTRAT_RANDOM: linear search (random order) 220 * - VM_PSTRAT_BSEARCH: binary search (sorted by address) 221 * - VM_PSTRAT_BIGFIRST: linear search (sorted by largest segment first) 222 * - others? 223 * XXXCDC: eventually we should purge all left-over global variables... 224 */ 225 #define VM_PSTRAT_RANDOM 1 226 #define VM_PSTRAT_BSEARCH 2 227 #define VM_PSTRAT_BIGFIRST 3 228 229 /* 230 * vm_physseg: describes one segment of physical memory 231 */ 232 struct vm_physseg { 233 paddr_t start; /* PF# of first page in segment */ 234 paddr_t end; /* (PF# of last page in segment) + 1 */ 235 paddr_t avail_start; /* PF# of first free page in segment */ 236 paddr_t avail_end; /* (PF# of last free page in segment) +1 */ 237 int free_list; /* which free list they belong on */ 238 struct vm_page *pgs; /* vm_page structures (from start) */ 239 struct vm_page *lastpg; /* vm_page structure for end */ 240 #ifdef __HAVE_PMAP_PHYSSEG 241 struct pmap_physseg pmseg; /* pmap specific (MD) data */ 242 #endif 243 }; 244 245 #ifdef _KERNEL 246 247 /* 248 * globals 249 */ 250 251 extern bool vm_page_zero_enable; 252 253 /* 254 * physical memory config is stored in vm_physmem. 255 */ 256 257 extern struct vm_physseg vm_physmem[VM_PHYSSEG_MAX]; 258 extern int vm_nphysseg; 259 260 /* 261 * prototypes: the following prototypes define the interface to pages 262 */ 263 264 void uvm_page_init(vaddr_t *, vaddr_t *); 265 #if defined(UVM_PAGE_TRKOWN) 266 void uvm_page_own(struct vm_page *, const char *); 267 #endif 268 #if !defined(PMAP_STEAL_MEMORY) 269 bool uvm_page_physget(paddr_t *); 270 #endif 271 void uvm_page_rehash(void); 272 void uvm_page_recolor(int); 273 void uvm_pageidlezero(void); 274 275 void uvm_pageactivate(struct vm_page *); 276 vaddr_t uvm_pageboot_alloc(vsize_t); 277 void uvm_pagecopy(struct vm_page *, struct vm_page *); 278 void uvm_pagedeactivate(struct vm_page *); 279 void uvm_pagedequeue(struct vm_page *); 280 void uvm_pageenqueue(struct vm_page *); 281 void uvm_pagefree(struct vm_page *); 282 void uvm_page_unbusy(struct vm_page **, int); 283 struct vm_page *uvm_pagelookup(struct uvm_object *, voff_t); 284 void uvm_pageunwire(struct vm_page *); 285 void uvm_pagewait(struct vm_page *, int); 286 void uvm_pagewake(struct vm_page *); 287 void uvm_pagewire(struct vm_page *); 288 void uvm_pagezero(struct vm_page *); 289 290 int uvm_page_lookup_freelist(struct vm_page *); 291 292 static struct vm_page *PHYS_TO_VM_PAGE(paddr_t); 293 static int vm_physseg_find(paddr_t, int *); 294 295 /* 296 * macros 297 */ 298 299 #define UVM_PAGE_HASH_PENALTY 4 /* XXX: a guess */ 300 301 #define uvm_pagehash(obj,off) \ 302 (((unsigned long)obj+(unsigned long)atop(off)) & uvm.page_hashmask) 303 304 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 305 306 /* 307 * Compute the page color bucket for a given page. 308 */ 309 #define VM_PGCOLOR_BUCKET(pg) \ 310 (atop(VM_PAGE_TO_PHYS((pg))) & uvmexp.colormask) 311 312 /* 313 * when VM_PHYSSEG_MAX is 1, we can simplify these functions 314 */ 315 316 /* 317 * vm_physseg_find: find vm_physseg structure that belongs to a PA 318 */ 319 static __inline int 320 vm_physseg_find(paddr_t pframe, int *offp) 321 { 322 #if VM_PHYSSEG_MAX == 1 323 324 /* 'contig' case */ 325 if (pframe >= vm_physmem[0].start && pframe < vm_physmem[0].end) { 326 if (offp) 327 *offp = pframe - vm_physmem[0].start; 328 return(0); 329 } 330 return(-1); 331 332 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 333 /* binary search for it */ 334 u_int start, len, try; 335 336 /* 337 * if try is too large (thus target is less than try) we reduce 338 * the length to trunc(len/2) [i.e. everything smaller than "try"] 339 * 340 * if the try is too small (thus target is greater than try) then 341 * we set the new start to be (try + 1). this means we need to 342 * reduce the length to (round(len/2) - 1). 343 * 344 * note "adjust" below which takes advantage of the fact that 345 * (round(len/2) - 1) == trunc((len - 1) / 2) 346 * for any value of len we may have 347 */ 348 349 for (start = 0, len = vm_nphysseg ; len != 0 ; len = len / 2) { 350 try = start + (len / 2); /* try in the middle */ 351 352 /* start past our try? */ 353 if (pframe >= vm_physmem[try].start) { 354 /* was try correct? */ 355 if (pframe < vm_physmem[try].end) { 356 if (offp) 357 *offp = pframe - vm_physmem[try].start; 358 return(try); /* got it */ 359 } 360 start = try + 1; /* next time, start here */ 361 len--; /* "adjust" */ 362 } else { 363 /* 364 * pframe before try, just reduce length of 365 * region, done in "for" loop 366 */ 367 } 368 } 369 return(-1); 370 371 #else 372 /* linear search for it */ 373 int lcv; 374 375 for (lcv = 0; lcv < vm_nphysseg; lcv++) { 376 if (pframe >= vm_physmem[lcv].start && 377 pframe < vm_physmem[lcv].end) { 378 if (offp) 379 *offp = pframe - vm_physmem[lcv].start; 380 return(lcv); /* got it */ 381 } 382 } 383 return(-1); 384 385 #endif 386 } 387 388 389 /* 390 * IS_VM_PHYSADDR: only used my mips/pmax/pica trap/pmap. 391 */ 392 393 #define IS_VM_PHYSADDR(PA) (vm_physseg_find(atop(PA), NULL) != -1) 394 395 /* 396 * PHYS_TO_VM_PAGE: find vm_page for a PA. used by MI code to get vm_pages 397 * back from an I/O mapping (ugh!). used in some MD code as well. 398 */ 399 static __inline struct vm_page * 400 PHYS_TO_VM_PAGE(paddr_t pa) 401 { 402 paddr_t pf = atop(pa); 403 int off; 404 int psi; 405 406 psi = vm_physseg_find(pf, &off); 407 if (psi != -1) 408 return(&vm_physmem[psi].pgs[off]); 409 return(NULL); 410 } 411 412 #define VM_PAGE_IS_FREE(entry) ((entry)->pqflags & PQ_FREE) 413 #define VM_FREE_PAGE_TO_CPU(pg) ((struct uvm_cpu *)((uintptr_t)pg->offset)) 414 415 #ifdef DEBUG 416 void uvm_pagezerocheck(struct vm_page *); 417 #endif /* DEBUG */ 418 419 #endif /* _KERNEL */ 420 421 #endif /* _UVM_UVM_PAGE_H_ */ 422