FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_page.h
1 /* $NetBSD: uvm_page.h,v 1.46 2006/09/15 15:51:13 yamt 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 uint16_t flags; /* object flags [O] */
130 uint16_t loan_count; /* number of active loans
131 * to read: [O or P]
132 * to modify: [O _and_ P] */
133 uint16_t wire_count; /* wired down map refs [P] */
134 uint16_t pqflags; /* page queue flags [P] */
135 paddr_t phys_addr; /* physical address of page */
136
137 #ifdef __HAVE_VM_PAGE_MD
138 struct vm_page_md mdpage; /* pmap-specific data */
139 #endif
140
141 #if defined(UVM_PAGE_TRKOWN)
142 /* debugging fields to track page ownership */
143 pid_t owner; /* proc that set PG_BUSY */
144 const char *owner_tag; /* why it was set busy */
145 #endif
146 };
147
148 /*
149 * These are the flags defined for vm_page.
150 */
151
152 /*
153 * locking rules:
154 * PG_ ==> locked by object lock
155 * PQ_ ==> lock by page queue lock
156 * PQ_FREE is locked by free queue lock and is mutex with all other PQs
157 *
158 * PG_ZERO is used to indicate that a page has been pre-zero'd. This flag
159 * is only set when the page is on no queues, and is cleared when the page
160 * is placed on the free list.
161 */
162
163 #define PG_BUSY 0x0001 /* page is locked */
164 #define PG_WANTED 0x0002 /* someone is waiting for page */
165 #define PG_TABLED 0x0004 /* page is in VP table */
166 #define PG_CLEAN 0x0008 /* page has not been modified */
167 #define PG_PAGEOUT 0x0010 /* page to be freed for pagedaemon */
168 #define PG_RELEASED 0x0020 /* page to be freed when unbusied */
169 #define PG_FAKE 0x0040 /* page is not yet initialized */
170 #define PG_RDONLY 0x0080 /* page must be mapped read-only */
171 #define PG_ZERO 0x0100 /* page is pre-zero'd */
172
173 #define PG_PAGER1 0x1000 /* pager-specific flag */
174
175 #define UVM_PGFLAGBITS \
176 "\2\1BUSY\2WANTED\3TABLED\4CLEAN\5PAGEOUT\6RELEASED\7FAKE\10RDONLY" \
177 "\11ZERO\15PAGER1"
178
179 #define PQ_FREE 0x0001 /* page is on free list */
180 #define PQ_ANON 0x0002 /* page is part of an anon, rather
181 than an uvm_object */
182 #define PQ_AOBJ 0x0004 /* page is part of an anonymous
183 uvm_object */
184 #define PQ_SWAPBACKED (PQ_ANON|PQ_AOBJ)
185 #define PQ_READAHEAD 0x0008 /* read-ahead but has not been "hit" yet */
186
187 #define PQ_PRIVATE1 0x0100
188 #define PQ_PRIVATE2 0x0200
189 #define PQ_PRIVATE3 0x0400
190 #define PQ_PRIVATE4 0x0800
191 #define PQ_PRIVATE5 0x1000
192 #define PQ_PRIVATE6 0x2000
193 #define PQ_PRIVATE7 0x4000
194 #define PQ_PRIVATE8 0x8000
195
196 #define UVM_PQFLAGBITS \
197 "\2\1FREE\2ANON\3AOBJ\4READAHEAD" \
198 "\11PRIVATE1\12PRIVATE2\13PRIVATE3\14PRIVATE4" \
199 "\15PRIVATE5\16PRIVATE6\17PRIVATE7\20PRIVATE8"
200
201 /*
202 * physical memory layout structure
203 *
204 * MD vmparam.h must #define:
205 * VM_PHYSEG_MAX = max number of physical memory segments we support
206 * (if this is "1" then we revert to a "contig" case)
207 * VM_PHYSSEG_STRAT: memory sort/search options (for VM_PHYSEG_MAX > 1)
208 * - VM_PSTRAT_RANDOM: linear search (random order)
209 * - VM_PSTRAT_BSEARCH: binary search (sorted by address)
210 * - VM_PSTRAT_BIGFIRST: linear search (sorted by largest segment first)
211 * - others?
212 * XXXCDC: eventually we should purge all left-over global variables...
213 */
214 #define VM_PSTRAT_RANDOM 1
215 #define VM_PSTRAT_BSEARCH 2
216 #define VM_PSTRAT_BIGFIRST 3
217
218 /*
219 * vm_physseg: describes one segment of physical memory
220 */
221 struct vm_physseg {
222 paddr_t start; /* PF# of first page in segment */
223 paddr_t end; /* (PF# of last page in segment) + 1 */
224 paddr_t avail_start; /* PF# of first free page in segment */
225 paddr_t avail_end; /* (PF# of last free page in segment) +1 */
226 int free_list; /* which free list they belong on */
227 struct vm_page *pgs; /* vm_page structures (from start) */
228 struct vm_page *lastpg; /* vm_page structure for end */
229 #ifdef __HAVE_PMAP_PHYSSEG
230 struct pmap_physseg pmseg; /* pmap specific (MD) data */
231 #endif
232 };
233
234 #ifdef _KERNEL
235
236 /*
237 * globals
238 */
239
240 extern boolean_t vm_page_zero_enable;
241
242 /*
243 * physical memory config is stored in vm_physmem.
244 */
245
246 extern struct vm_physseg vm_physmem[VM_PHYSSEG_MAX];
247 extern int vm_nphysseg;
248
249 /*
250 * prototypes: the following prototypes define the interface to pages
251 */
252
253 void uvm_page_init(vaddr_t *, vaddr_t *);
254 #if defined(UVM_PAGE_TRKOWN)
255 void uvm_page_own(struct vm_page *, const char *);
256 #endif
257 #if !defined(PMAP_STEAL_MEMORY)
258 boolean_t uvm_page_physget(paddr_t *);
259 #endif
260 void uvm_page_rehash(void);
261 void uvm_page_recolor(int);
262 void uvm_pageidlezero(void);
263
264 int uvm_lock_fpageq(void);
265 void uvm_unlock_fpageq(int);
266
267 void uvm_pageactivate(struct vm_page *);
268 vaddr_t uvm_pageboot_alloc(vsize_t);
269 void uvm_pagecopy(struct vm_page *, struct vm_page *);
270 void uvm_pagedeactivate(struct vm_page *);
271 void uvm_pagedequeue(struct vm_page *);
272 void uvm_pageenqueue(struct vm_page *);
273 void uvm_pagefree(struct vm_page *);
274 void uvm_page_unbusy(struct vm_page **, int);
275 struct vm_page *uvm_pagelookup(struct uvm_object *, voff_t);
276 void uvm_pageunwire(struct vm_page *);
277 void uvm_pagewait(struct vm_page *, int);
278 void uvm_pagewake(struct vm_page *);
279 void uvm_pagewire(struct vm_page *);
280 void uvm_pagezero(struct vm_page *);
281
282 int uvm_page_lookup_freelist(struct vm_page *);
283
284 static struct vm_page *PHYS_TO_VM_PAGE(paddr_t);
285 static int vm_physseg_find(paddr_t, int *);
286
287 /*
288 * macros
289 */
290
291 #define UVM_PAGE_HASH_PENALTY 4 /* XXX: a guess */
292
293 #define uvm_lock_pageq() simple_lock(&uvm.pageqlock)
294 #define uvm_unlock_pageq() simple_unlock(&uvm.pageqlock)
295 #define UVM_LOCK_ASSERT_PAGEQ() LOCK_ASSERT(simple_lock_held(&uvm.pageqlock))
296
297 #define uvm_pagehash(obj,off) \
298 (((unsigned long)obj+(unsigned long)atop(off)) & uvm.page_hashmask)
299
300 #define UVM_PAGEZERO_TARGET (uvmexp.free)
301
302 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
303
304 /*
305 * Compute the page color bucket for a given page.
306 */
307 #define VM_PGCOLOR_BUCKET(pg) \
308 (atop(VM_PAGE_TO_PHYS((pg))) & uvmexp.colormask)
309
310 /*
311 * when VM_PHYSSEG_MAX is 1, we can simplify these functions
312 */
313
314 /*
315 * vm_physseg_find: find vm_physseg structure that belongs to a PA
316 */
317 static __inline int
318 vm_physseg_find(pframe, offp)
319 paddr_t pframe;
320 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(pa)
401 paddr_t pa;
402 {
403 paddr_t pf = atop(pa);
404 int off;
405 int psi;
406
407 psi = vm_physseg_find(pf, &off);
408 if (psi != -1)
409 return(&vm_physmem[psi].pgs[off]);
410 return(NULL);
411 }
412
413 #define VM_PAGE_IS_FREE(entry) ((entry)->pqflags & PQ_FREE)
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_ */
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