Annotation of sys/uvm/uvm_page.h, Revision 1.1.1.1
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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