Annotation of sys/uvm/uvm_page.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: uvm_page.h,v 1.25 2007/04/18 18:51:37 art Exp $ */
! 2: /* $NetBSD: uvm_page.h,v 1.19 2000/12/28 08:24:55 chs Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1997 Charles D. Cranor and Washington University.
! 6: * Copyright (c) 1991, 1993, The Regents of the University of California.
! 7: *
! 8: * All rights reserved.
! 9: *
! 10: * This code is derived from software contributed to Berkeley by
! 11: * The Mach Operating System project at Carnegie-Mellon University.
! 12: *
! 13: * Redistribution and use in source and binary forms, with or without
! 14: * modification, are permitted provided that the following conditions
! 15: * are met:
! 16: * 1. Redistributions of source code must retain the above copyright
! 17: * notice, this list of conditions and the following disclaimer.
! 18: * 2. Redistributions in binary form must reproduce the above copyright
! 19: * notice, this list of conditions and the following disclaimer in the
! 20: * documentation and/or other materials provided with the distribution.
! 21: * 3. All advertising materials mentioning features or use of this software
! 22: * must display the following acknowledgement:
! 23: * This product includes software developed by Charles D. Cranor,
! 24: * Washington University, the University of California, Berkeley and
! 25: * its contributors.
! 26: * 4. Neither the name of the University nor the names of its contributors
! 27: * may be used to endorse or promote products derived from this software
! 28: * without specific prior written permission.
! 29: *
! 30: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 31: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 32: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 33: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 34: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 35: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 36: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 37: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 38: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 39: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 40: * SUCH DAMAGE.
! 41: *
! 42: * @(#)vm_page.h 7.3 (Berkeley) 4/21/91
! 43: * from: Id: uvm_page.h,v 1.1.2.6 1998/02/04 02:31:42 chuck Exp
! 44: *
! 45: *
! 46: * Copyright (c) 1987, 1990 Carnegie-Mellon University.
! 47: * All rights reserved.
! 48: *
! 49: * Permission to use, copy, modify and distribute this software and
! 50: * its documentation is hereby granted, provided that both the copyright
! 51: * notice and this permission notice appear in all copies of the
! 52: * software, derivative works or modified versions, and any portions
! 53: * thereof, and that both notices appear in supporting documentation.
! 54: *
! 55: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
! 56: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
! 57: * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
! 58: *
! 59: * Carnegie Mellon requests users of this software to return to
! 60: *
! 61: * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
! 62: * School of Computer Science
! 63: * Carnegie Mellon University
! 64: * Pittsburgh PA 15213-3890
! 65: *
! 66: * any improvements or extensions that they make and grant Carnegie the
! 67: * rights to redistribute these changes.
! 68: */
! 69:
! 70: #ifndef _UVM_UVM_PAGE_H_
! 71: #define _UVM_UVM_PAGE_H_
! 72:
! 73: /*
! 74: * uvm_page.h
! 75: */
! 76:
! 77: /*
! 78: * Resident memory system definitions.
! 79: */
! 80:
! 81: /*
! 82: * Management of resident (logical) pages.
! 83: *
! 84: * A small structure is kept for each resident
! 85: * page, indexed by page number. Each structure
! 86: * is an element of several lists:
! 87: *
! 88: * A hash table bucket used to quickly
! 89: * perform object/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: #include <uvm/uvm_extern.h>
! 107: #include <uvm/uvm_pglist.h>
! 108:
! 109: struct vm_page {
! 110: TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO
! 111: * queue or free list (P) */
! 112: TAILQ_ENTRY(vm_page) hashq; /* hash table links (O)*/
! 113: TAILQ_ENTRY(vm_page) listq; /* pages in same object (O)*/
! 114:
! 115: struct vm_anon *uanon; /* anon (O,P) */
! 116: struct uvm_object *uobject; /* object (O,P) */
! 117: voff_t offset; /* offset into object (O,P) */
! 118:
! 119: u_int pg_flags; /* object flags [O or P] */
! 120:
! 121: u_int pg_version; /* version count [O] */
! 122: u_int wire_count; /* wired down map refs [P] */
! 123:
! 124: u_int loan_count; /* number of active loans
! 125: * to read: [O or P]
! 126: * to modify: [O _and_ P] */
! 127: paddr_t phys_addr; /* physical address of page */
! 128:
! 129: #ifdef __HAVE_VM_PAGE_MD
! 130: struct vm_page_md mdpage; /* pmap-specific data */
! 131: #endif
! 132: #if defined(UVM_PAGE_TRKOWN)
! 133: /* debugging fields to track page ownership */
! 134: pid_t owner; /* proc that set PG_BUSY */
! 135: char *owner_tag; /* why it was set busy */
! 136: #endif
! 137: };
! 138:
! 139: /*
! 140: * These are the flags defined for vm_page.
! 141: *
! 142: * Note: PG_FILLED and PG_DIRTY are added for the filesystems.
! 143: */
! 144:
! 145: /*
! 146: * locking rules:
! 147: * PG_ ==> locked by object lock
! 148: * PQ_ ==> lock by page queue lock
! 149: * PQ_FREE is locked by free queue lock and is mutex with all other PQs
! 150: * pg_flags may only be changed using the atomic operations.
! 151: *
! 152: * PG_ZERO is used to indicate that a page has been pre-zero'd. This flag
! 153: * is only set when the page is on no queues, and is cleared when the page
! 154: * is placed on the free list.
! 155: */
! 156:
! 157: #define PG_BUSY 0x00000001 /* page is locked */
! 158: #define PG_WANTED 0x00000002 /* someone is waiting for page */
! 159: #define PG_TABLED 0x00000004 /* page is in VP table */
! 160: #define PG_CLEAN 0x00000008 /* page has not been modified */
! 161: #define PG_CLEANCHK 0x00000010 /* clean bit has been checked */
! 162: #define PG_RELEASED 0x00000020 /* page released while paging */
! 163: #define PG_FAKE 0x00000040 /* page is not yet initialized */
! 164: #define PG_RDONLY 0x00000080 /* page must be mapped read-only */
! 165: #define PG_ZERO 0x00000100 /* page is pre-zero'd */
! 166:
! 167: #define PG_PAGER1 0x00001000 /* pager-specific flag */
! 168: #define PG_MASK 0x0000ffff
! 169:
! 170: #define PQ_FREE 0x00010000 /* page is on free list */
! 171: #define PQ_INACTIVE 0x00020000 /* page is in inactive list */
! 172: #define PQ_ACTIVE 0x00040000 /* page is in active list */
! 173: #define PQ_ANON 0x00100000 /* page is part of an anon, rather
! 174: than an uvm_object */
! 175: #define PQ_AOBJ 0x00200000 /* page is part of an anonymous
! 176: uvm_object */
! 177: #define PQ_SWAPBACKED (PQ_ANON|PQ_AOBJ)
! 178: #define PQ_ENCRYPT 0x00400000 /* page needs {en,de}cryption */
! 179: #define PQ_MASK 0x00ff0000
! 180:
! 181: #define PG_PMAP0 0x01000000 /* Used by some pmaps. */
! 182: #define PG_PMAP1 0x02000000 /* Used by some pmaps. */
! 183: #define PG_PMAP2 0x04000000 /* Used by some pmaps. */
! 184: #define PG_PMAP3 0x08000000 /* Used by some pmaps. */
! 185:
! 186: /*
! 187: * physical memory layout structure
! 188: *
! 189: * MD vmparam.h must #define:
! 190: * VM_PHYSEG_MAX = max number of physical memory segments we support
! 191: * (if this is "1" then we revert to a "contig" case)
! 192: * VM_PHYSSEG_STRAT: memory sort/search options (for VM_PHYSEG_MAX > 1)
! 193: * - VM_PSTRAT_RANDOM: linear search (random order)
! 194: * - VM_PSTRAT_BSEARCH: binary search (sorted by address)
! 195: * - VM_PSTRAT_BIGFIRST: linear search (sorted by largest segment first)
! 196: * - others?
! 197: * XXXCDC: eventually we should purge all left-over global variables...
! 198: */
! 199: #define VM_PSTRAT_RANDOM 1
! 200: #define VM_PSTRAT_BSEARCH 2
! 201: #define VM_PSTRAT_BIGFIRST 3
! 202:
! 203: /*
! 204: * vm_physmemseg: describes one segment of physical memory
! 205: */
! 206: struct vm_physseg {
! 207: paddr_t start; /* PF# of first page in segment */
! 208: paddr_t end; /* (PF# of last page in segment) + 1 */
! 209: paddr_t avail_start; /* PF# of first free page in segment */
! 210: paddr_t avail_end; /* (PF# of last free page in segment) +1 */
! 211: int free_list; /* which free list they belong on */
! 212: struct vm_page *pgs; /* vm_page structures (from start) */
! 213: struct vm_page *lastpg; /* vm_page structure for end */
! 214: #ifdef __HAVE_PMAP_PHYSSEG
! 215: struct pmap_physseg pmseg; /* pmap specific (MD) data */
! 216: #endif
! 217: };
! 218:
! 219: #ifdef _KERNEL
! 220:
! 221: /*
! 222: * globals
! 223: */
! 224:
! 225: extern boolean_t vm_page_zero_enable;
! 226:
! 227: /*
! 228: * Each pageable resident page falls into one of three lists:
! 229: *
! 230: * free
! 231: * Available for allocation now.
! 232: * inactive
! 233: * Not referenced in any map, but still has an
! 234: * object/offset-page mapping, and may be dirty.
! 235: * This is the list of pages that should be
! 236: * paged out next.
! 237: * active
! 238: * A list of pages which have been placed in
! 239: * at least one physical map. This list is
! 240: * ordered, in LRU-like fashion.
! 241: */
! 242:
! 243: extern struct pglist vm_page_queue_free; /* memory free queue */
! 244: extern struct pglist vm_page_queue_active; /* active memory queue */
! 245: extern struct pglist vm_page_queue_inactive; /* inactive memory queue */
! 246:
! 247: /*
! 248: * physical memory config is stored in vm_physmem.
! 249: */
! 250:
! 251: extern struct vm_physseg vm_physmem[VM_PHYSSEG_MAX];
! 252: extern int vm_nphysseg;
! 253:
! 254: /*
! 255: * handle inline options
! 256: */
! 257:
! 258: #ifdef UVM_PAGE_INLINE
! 259: #define PAGE_INLINE static __inline
! 260: #else
! 261: #define PAGE_INLINE /* nothing */
! 262: #endif /* UVM_PAGE_INLINE */
! 263:
! 264: /*
! 265: * prototypes: the following prototypes define the interface to pages
! 266: */
! 267:
! 268: void uvm_page_init(vaddr_t *, vaddr_t *);
! 269: #if defined(UVM_PAGE_TRKOWN)
! 270: void uvm_page_own(struct vm_page *, char *);
! 271: #endif
! 272: #if !defined(PMAP_STEAL_MEMORY)
! 273: boolean_t uvm_page_physget(paddr_t *);
! 274: #endif
! 275: void uvm_page_rehash(void);
! 276: void uvm_pageidlezero(void);
! 277:
! 278: PAGE_INLINE int uvm_lock_fpageq(void);
! 279: PAGE_INLINE void uvm_unlock_fpageq(int);
! 280:
! 281: PAGE_INLINE void uvm_pageactivate(struct vm_page *);
! 282: vaddr_t uvm_pageboot_alloc(vsize_t);
! 283: PAGE_INLINE void uvm_pagecopy(struct vm_page *, struct vm_page *);
! 284: PAGE_INLINE void uvm_pagedeactivate(struct vm_page *);
! 285: void uvm_pagefree(struct vm_page *);
! 286: void uvm_page_unbusy(struct vm_page **, int);
! 287: PAGE_INLINE struct vm_page *uvm_pagelookup(struct uvm_object *, voff_t);
! 288: PAGE_INLINE void uvm_pageunwire(struct vm_page *);
! 289: PAGE_INLINE void uvm_pagewait(struct vm_page *, int);
! 290: PAGE_INLINE void uvm_pagewake(struct vm_page *);
! 291: PAGE_INLINE void uvm_pagewire(struct vm_page *);
! 292: PAGE_INLINE void uvm_pagezero(struct vm_page *);
! 293:
! 294: PAGE_INLINE int uvm_page_lookup_freelist(struct vm_page *);
! 295:
! 296: static struct vm_page *PHYS_TO_VM_PAGE(paddr_t);
! 297: static int vm_physseg_find(paddr_t, int *);
! 298:
! 299: /*
! 300: * macros
! 301: */
! 302:
! 303: #define uvm_lock_pageq() simple_lock(&uvm.pageqlock)
! 304: #define uvm_unlock_pageq() simple_unlock(&uvm.pageqlock)
! 305:
! 306: #define uvm_pagehash(obj,off) \
! 307: (((unsigned long)obj+(unsigned long)atop(off)) & uvm.page_hashmask)
! 308:
! 309: #define UVM_PAGEZERO_TARGET (uvmexp.free)
! 310:
! 311: #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
! 312:
! 313: /*
! 314: * when VM_PHYSSEG_MAX is 1, we can simplify these functions
! 315: */
! 316:
! 317: /*
! 318: * vm_physseg_find: find vm_physseg structure that belongs to a PA
! 319: */
! 320: static __inline int
! 321: vm_physseg_find(pframe, offp)
! 322: paddr_t pframe;
! 323: int *offp;
! 324: {
! 325: #if VM_PHYSSEG_MAX == 1
! 326:
! 327: /* 'contig' case */
! 328: if (pframe >= vm_physmem[0].start && pframe < vm_physmem[0].end) {
! 329: if (offp)
! 330: *offp = pframe - vm_physmem[0].start;
! 331: return(0);
! 332: }
! 333: return(-1);
! 334:
! 335: #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH)
! 336: /* binary search for it */
! 337: int start, len, try;
! 338:
! 339: /*
! 340: * if try is too large (thus target is less than than try) we reduce
! 341: * the length to trunc(len/2) [i.e. everything smaller than "try"]
! 342: *
! 343: * if the try is too small (thus target is greater than try) then
! 344: * we set the new start to be (try + 1). this means we need to
! 345: * reduce the length to (round(len/2) - 1).
! 346: *
! 347: * note "adjust" below which takes advantage of the fact that
! 348: * (round(len/2) - 1) == trunc((len - 1) / 2)
! 349: * for any value of len we may have
! 350: */
! 351:
! 352: for (start = 0, len = vm_nphysseg ; len != 0 ; len = len / 2) {
! 353: try = start + (len / 2); /* try in the middle */
! 354:
! 355: /* start past our try? */
! 356: if (pframe >= vm_physmem[try].start) {
! 357: /* was try correct? */
! 358: if (pframe < vm_physmem[try].end) {
! 359: if (offp)
! 360: *offp = pframe - vm_physmem[try].start;
! 361: return(try); /* got it */
! 362: }
! 363: start = try + 1; /* next time, start here */
! 364: len--; /* "adjust" */
! 365: } else {
! 366: /*
! 367: * pframe before try, just reduce length of
! 368: * region, done in "for" loop
! 369: */
! 370: }
! 371: }
! 372: return(-1);
! 373:
! 374: #else
! 375: /* linear search for it */
! 376: int lcv;
! 377:
! 378: for (lcv = 0; lcv < vm_nphysseg; lcv++) {
! 379: if (pframe >= vm_physmem[lcv].start &&
! 380: pframe < vm_physmem[lcv].end) {
! 381: if (offp)
! 382: *offp = pframe - vm_physmem[lcv].start;
! 383: return(lcv); /* got it */
! 384: }
! 385: }
! 386: return(-1);
! 387:
! 388: #endif
! 389: }
! 390:
! 391: /*
! 392: * PHYS_TO_VM_PAGE: find vm_page for a PA. used by MI code to get vm_pages
! 393: * back from an I/O mapping (ugh!). used in some MD code as well.
! 394: */
! 395: static __inline struct vm_page *
! 396: PHYS_TO_VM_PAGE(pa)
! 397: paddr_t pa;
! 398: {
! 399: paddr_t pf = atop(pa);
! 400: int off;
! 401: int psi;
! 402:
! 403: psi = vm_physseg_find(pf, &off);
! 404: if (psi != -1)
! 405: return(&vm_physmem[psi].pgs[off]);
! 406: return(NULL);
! 407: }
! 408:
! 409: #define VM_PAGE_IS_FREE(entry) ((entry)->pg_flags & PQ_FREE)
! 410:
! 411: #endif /* _KERNEL */
! 412:
! 413: #endif /* _UVM_UVM_PAGE_H_ */
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