1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. 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 * from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93 37 * 38 * 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 * 64 * $Id: vm_page.h,v 1.24 1996/01/19 04:00:17 dyson Exp $ 65 */ 66 67 /* 68 * Resident memory system definitions. 69 */ 70 71 #ifndef _VM_PAGE_ 72 #define _VM_PAGE_ 73 74 #include <vm/pmap.h> 75 /* 76 * Management of resident (logical) pages. 77 * 78 * A small structure is kept for each resident 79 * page, indexed by page number. Each structure 80 * is an element of several lists: 81 * 82 * A hash table bucket used to quickly 83 * perform object/offset lookups 84 * 85 * A list of all pages for a given object, 86 * so they can be quickly deactivated at 87 * time of deallocation. 88 * 89 * An ordered list of pages due for pageout. 90 * 91 * In addition, the structure contains the object 92 * and offset to which this page belongs (for pageout), 93 * and sundry status bits. 94 * 95 * Fields in this structure are locked either by the lock on the 96 * object that the page belongs to (O) or by the lock on the page 97 * queues (P). 98 */ 99 100 TAILQ_HEAD(pglist, vm_page); 101 102 struct vm_page { 103 TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (P) */ 104 TAILQ_ENTRY(vm_page) hashq; /* hash table links (O) */ 105 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */ 106 107 vm_object_t object; /* which object am I in (O,P) */ 108 vm_pindex_t pindex; /* offset into object (O,P) */ 109 vm_offset_t phys_addr; /* physical address of page */ 110 u_short queue:4, /* page queue index */ 111 flags:12; /* see below */ 112 u_short wire_count; /* wired down maps refs (P) */ 113 short hold_count; /* page hold count */ 114 u_char act_count; /* page usage count */ 115 u_char busy; /* page busy count */ 116 /* NOTE that these must support one bit per DEV_BSIZE in a page!!! */ 117 /* so, on normal X86 kernels, they must be at least 8 bits wide */ 118 u_char valid; /* map of valid DEV_BSIZE chunks */ 119 u_char dirty; /* map of dirty DEV_BSIZE chunks */ 120 }; 121 122 #define PQ_NONE 0 123 #define PQ_FREE 1 124 #define PQ_ZERO 2 125 #define PQ_INACTIVE 3 126 #define PQ_ACTIVE 4 127 #define PQ_CACHE 5 128 129 /* 130 * These are the flags defined for vm_page. 131 * 132 * Note: PG_FILLED and PG_DIRTY are added for the filesystems. 133 */ 134 #define PG_BUSY 0x01 /* page is in transit (O) */ 135 #define PG_WANTED 0x02 /* someone is waiting for page (O) */ 136 #define PG_TABLED 0x04 /* page is in VP table (O) */ 137 #define PG_FICTITIOUS 0x08 /* physical page doesn't exist (O) */ 138 #define PG_WRITEABLE 0x10 /* page is mapped writeable */ 139 #define PG_MAPPED 0x20 /* page is mapped */ 140 #define PG_ZERO 0x40 /* page is zeroed */ 141 #define PG_REFERENCED 0x80 /* page has been referenced */ 142 #define PG_CLEANCHK 0x100 /* page has been checked for cleaning */ 143 144 /* 145 * Misc constants. 146 */ 147 148 #define ACT_DECLINE 1 149 #define ACT_ADVANCE 3 150 #define ACT_MAX 100 151 #define PFCLUSTER_BEHIND 3 152 #define PFCLUSTER_AHEAD 3 153 154 #ifdef KERNEL 155 /* 156 * Each pageable resident page falls into one of four lists: 157 * 158 * free 159 * Available for allocation now. 160 * 161 * The following are all LRU sorted: 162 * 163 * cache 164 * Almost available for allocation. Still in an 165 * object, but clean and immediately freeable at 166 * non-interrupt times. 167 * 168 * inactive 169 * Low activity, candidates for reclamation. 170 * This is the list of pages that should be 171 * paged out next. 172 * 173 * active 174 * Pages that are "active" i.e. they have been 175 * recently referenced. 176 * 177 * zero 178 * Pages that are really free and have been pre-zeroed 179 * 180 */ 181 182 extern struct pglist vm_page_queue_free; /* memory free queue */ 183 extern struct pglist vm_page_queue_zero; /* zeroed memory free queue */ 184 extern struct pglist vm_page_queue_active; /* active memory queue */ 185 extern struct pglist vm_page_queue_inactive; /* inactive memory queue */ 186 extern struct pglist vm_page_queue_cache; /* cache memory queue */ 187 188 extern int vm_page_zero_count; 189 190 extern vm_page_t vm_page_array; /* First resident page in table */ 191 extern long first_page; /* first physical page number */ 192 193 /* ... represented in vm_page_array */ 194 extern long last_page; /* last physical page number */ 195 196 /* ... represented in vm_page_array */ 197 /* [INCLUSIVE] */ 198 extern vm_offset_t first_phys_addr; /* physical address for first_page */ 199 extern vm_offset_t last_phys_addr; /* physical address for last_page */ 200 201 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 202 203 #define IS_VM_PHYSADDR(pa) \ 204 ((pa) >= first_phys_addr && (pa) <= last_phys_addr) 205 206 #define PHYS_TO_VM_PAGE(pa) \ 207 (&vm_page_array[atop(pa) - first_page ]) 208 209 /* 210 * Functions implemented as macros 211 */ 212 213 #define PAGE_ASSERT_WAIT(m, interruptible) { \ 214 (m)->flags |= PG_WANTED; \ 215 assert_wait((int) (m), (interruptible)); \ 216 } 217 218 #define PAGE_WAKEUP(m) { \ 219 (m)->flags &= ~PG_BUSY; \ 220 if ((m)->flags & PG_WANTED) { \ 221 (m)->flags &= ~PG_WANTED; \ 222 wakeup((caddr_t) (m)); \ 223 } \ 224 } 225 226 #if PAGE_SIZE == 4096 227 #define VM_PAGE_BITS_ALL 0xff 228 #endif 229 230 #if PAGE_SIZE == 8192 231 #define VM_PAGE_BITS_ALL 0xffff 232 #endif 233 234 #define VM_ALLOC_NORMAL 0 235 #define VM_ALLOC_INTERRUPT 1 236 #define VM_ALLOC_SYSTEM 2 237 #define VM_ALLOC_ZERO 3 238 239 void vm_page_activate __P((vm_page_t)); 240 vm_page_t vm_page_alloc __P((vm_object_t, vm_pindex_t, int)); 241 void vm_page_cache __P((register vm_page_t)); 242 void vm_page_copy __P((vm_page_t, vm_page_t)); 243 void vm_page_deactivate __P((vm_page_t)); 244 void vm_page_free __P((vm_page_t)); 245 void vm_page_insert __P((vm_page_t, vm_object_t, vm_pindex_t)); 246 vm_page_t vm_page_lookup __P((vm_object_t, vm_pindex_t)); 247 void vm_page_remove __P((vm_page_t)); 248 void vm_page_rename __P((vm_page_t, vm_object_t, vm_pindex_t)); 249 vm_offset_t vm_page_startup __P((vm_offset_t, vm_offset_t, vm_offset_t)); 250 void vm_page_unwire __P((vm_page_t)); 251 void vm_page_wire __P((vm_page_t)); 252 boolean_t vm_page_zero_fill __P((vm_page_t)); 253 void vm_page_set_validclean __P((vm_page_t, int, int)); 254 void vm_page_set_invalid __P((vm_page_t, int, int)); 255 int vm_page_is_valid __P((vm_page_t, int, int)); 256 void vm_page_test_dirty __P((vm_page_t)); 257 int vm_page_bits __P((int, int)); 258 259 260 /* 261 * Keep page from being freed by the page daemon 262 * much of the same effect as wiring, except much lower 263 * overhead and should be used only for *very* temporary 264 * holding ("wiring"). 265 */ 266 static __inline void 267 vm_page_hold(vm_page_t mem) 268 { 269 mem->hold_count++; 270 } 271 272 #ifdef DIAGNOSTIC 273 #include <sys/systm.h> /* make GCC shut up */ 274 #endif 275 276 static __inline void 277 vm_page_unhold(vm_page_t mem) 278 { 279 #ifdef DIAGNOSTIC 280 if (--mem->hold_count < 0) 281 panic("vm_page_unhold: hold count < 0!!!"); 282 #else 283 --mem->hold_count; 284 #endif 285 } 286 287 static __inline void 288 vm_page_protect(vm_page_t mem, int prot) 289 { 290 if (prot == VM_PROT_NONE) { 291 if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) { 292 pmap_page_protect(VM_PAGE_TO_PHYS(mem), prot); 293 mem->flags &= ~(PG_WRITEABLE|PG_MAPPED); 294 } 295 } else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) { 296 pmap_page_protect(VM_PAGE_TO_PHYS(mem), prot); 297 mem->flags &= ~PG_WRITEABLE; 298 } 299 } 300 301 302 #endif /* KERNEL */ 303 #endif /* !_VM_PAGE_ */ 304