1 /* $OpenBSD: uvm_page.h,v 1.21 2003/11/08 19:17:28 jmc 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 /*
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 (simple_lock's). so, we've
113 * separated things 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 struct vm_page {
122 TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO
123 * queue or free list (P) */
124 TAILQ_ENTRY(vm_page) hashq; /* hash table links (O)*/
125 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O)*/
126
127 struct vm_anon *uanon; /* anon (O,P) */
128 struct uvm_object *uobject; /* object (O,P) */
129 voff_t offset; /* offset into object (O,P) */
130
131 u_short flags; /* object flags [O] */
132 u_short version; /* version count [O] */
133 u_short wire_count; /* wired down map refs [P] */
134 u_short pqflags; /* page queue flags [P] */
135 u_int loan_count; /* number of active loans
136 * to read: [O or P]
137 * to modify: [O _and_ P] */
138 paddr_t phys_addr; /* physical address of page */
139
140 #ifdef __HAVE_VM_PAGE_MD
141 struct vm_page_md mdpage; /* pmap-specific data */
142 #endif
143 #if defined(UVM_PAGE_TRKOWN)
144 /* debugging fields to track page ownership */
145 pid_t owner; /* proc that set PG_BUSY */
146 char *owner_tag; /* why it was set busy */
147 #endif
148 };
149
150 /*
151 * These are the flags defined for vm_page.
152 *
153 * Note: PG_FILLED and PG_DIRTY are added for the filesystems.
154 */
155
156 /*
157 * locking rules:
158 * PG_ ==> locked by object lock
159 * PQ_ ==> lock by page queue lock
160 * PQ_FREE is locked by free queue lock and is mutex with all other PQs
161 *
162 * PG_ZERO is used to indicate that a page has been pre-zero'd. This flag
163 * is only set when the page is on no queues, and is cleared when the page
164 * is placed on the free list.
165 */
166
167 #define PG_BUSY 0x0001 /* page is locked */
168 #define PG_WANTED 0x0002 /* someone is waiting for page */
169 #define PG_TABLED 0x0004 /* page is in VP table */
170 #define PG_CLEAN 0x0008 /* page has not been modified */
171 #define PG_CLEANCHK 0x0010 /* clean bit has been checked */
172 #define PG_RELEASED 0x0020 /* page released while paging */
173 #define PG_FAKE 0x0040 /* page is not yet initialized */
174 #define PG_RDONLY 0x0080 /* page must be mapped read-only */
175 #define PG_ZERO 0x0100 /* page is pre-zero'd */
176
177 #define PG_PAGER1 0x1000 /* pager-specific flag */
178
179 #define PQ_FREE 0x0001 /* page is on free list */
180 #define PQ_INACTIVE 0x0002 /* page is in inactive list */
181 #define PQ_ACTIVE 0x0004 /* page is in active list */
182 #define PQ_ANON 0x0010 /* page is part of an anon, rather
183 than an uvm_object */
184 #define PQ_AOBJ 0x0020 /* page is part of an anonymous
185 uvm_object */
186 #define PQ_SWAPBACKED (PQ_ANON|PQ_AOBJ)
187 #define PQ_ENCRYPT 0x0040 /* page needs {en,de}cryption */
188
189 /*
190 * physical memory layout structure
191 *
192 * MD vmparam.h must #define:
193 * VM_PHYSEG_MAX = max number of physical memory segments we support
194 * (if this is "1" then we revert to a "contig" case)
195 * VM_PHYSSEG_STRAT: memory sort/search options (for VM_PHYSEG_MAX > 1)
196 * - VM_PSTRAT_RANDOM: linear search (random order)
197 * - VM_PSTRAT_BSEARCH: binary search (sorted by address)
198 * - VM_PSTRAT_BIGFIRST: linear search (sorted by largest segment first)
199 * - others?
200 * XXXCDC: eventually we should purge all left-over global variables...
201 */
202 #define VM_PSTRAT_RANDOM 1
203 #define VM_PSTRAT_BSEARCH 2
204 #define VM_PSTRAT_BIGFIRST 3
205
206 /*
207 * vm_physmemseg: describes one segment of physical memory
208 */
209 struct vm_physseg {
210 paddr_t start; /* PF# of first page in segment */
211 paddr_t end; /* (PF# of last page in segment) + 1 */
212 paddr_t avail_start; /* PF# of first free page in segment */
213 paddr_t avail_end; /* (PF# of last free page in segment) +1 */
214 int free_list; /* which free list they belong on */
215 struct vm_page *pgs; /* vm_page structures (from start) */
216 struct vm_page *lastpg; /* vm_page structure for end */
217 #ifdef __HAVE_PMAP_PHYSSEG
218 struct pmap_physseg pmseg; /* pmap specific (MD) data */
219 #endif
220 };
221
222 #ifdef _KERNEL
223
224 /*
225 * globals
226 */
227
228 extern boolean_t vm_page_zero_enable;
229
230 /*
231 * Each pageable resident page falls into one of three lists:
232 *
233 * free
234 * Available for allocation now.
235 * inactive
236 * Not referenced in any map, but still has an
237 * object/offset-page mapping, and may be dirty.
238 * This is the list of pages that should be
239 * paged out next.
240 * active
241 * A list of pages which have been placed in
242 * at least one physical map. This list is
243 * ordered, in LRU-like fashion.
244 */
245
246 extern struct pglist vm_page_queue_free; /* memory free queue */
247 extern struct pglist vm_page_queue_active; /* active memory queue */
248 extern struct pglist vm_page_queue_inactive; /* inactive memory queue */
249
250 /*
251 * physical memory config is stored in vm_physmem.
252 */
253
254 extern struct vm_physseg vm_physmem[VM_PHYSSEG_MAX];
255 extern int vm_nphysseg;
256
257 /*
258 * handle inline options
259 */
260
261 #ifdef UVM_PAGE_INLINE
262 #define PAGE_INLINE static __inline
263 #else
264 #define PAGE_INLINE /* nothing */
265 #endif /* UVM_PAGE_INLINE */
266
267 /*
268 * prototypes: the following prototypes define the interface to pages
269 */
270
271 void uvm_page_init(vaddr_t *, vaddr_t *);
272 #if defined(UVM_PAGE_TRKOWN)
273 void uvm_page_own(struct vm_page *, char *);
274 #endif
275 #if !defined(PMAP_STEAL_MEMORY)
276 boolean_t uvm_page_physget(paddr_t *);
277 #endif
278 void uvm_page_rehash(void);
279 void uvm_pageidlezero(void);
280
281 PAGE_INLINE int uvm_lock_fpageq(void);
282 PAGE_INLINE void uvm_unlock_fpageq(int);
283
284 PAGE_INLINE void uvm_pageactivate(struct vm_page *);
285 vaddr_t uvm_pageboot_alloc(vsize_t);
286 PAGE_INLINE void uvm_pagecopy(struct vm_page *, struct vm_page *);
287 PAGE_INLINE void uvm_pagedeactivate(struct vm_page *);
288 void uvm_pagefree(struct vm_page *);
289 void uvm_page_unbusy(struct vm_page **, int);
290 PAGE_INLINE struct vm_page *uvm_pagelookup(struct uvm_object *, voff_t);
291 PAGE_INLINE void uvm_pageunwire(struct vm_page *);
292 PAGE_INLINE void uvm_pagewait(struct vm_page *, int);
293 PAGE_INLINE void uvm_pagewake(struct vm_page *);
294 PAGE_INLINE void uvm_pagewire(struct vm_page *);
295 PAGE_INLINE void uvm_pagezero(struct vm_page *);
296
297 PAGE_INLINE int uvm_page_lookup_freelist(struct vm_page *);
298
299 static struct vm_page *PHYS_TO_VM_PAGE(paddr_t);
300 static int vm_physseg_find(paddr_t, int *);
301
302 /*
303 * macros
304 */
305
306 #define uvm_lock_pageq() simple_lock(&uvm.pageqlock)
307 #define uvm_unlock_pageq() simple_unlock(&uvm.pageqlock)
308
309 #define uvm_pagehash(obj,off) \
310 (((unsigned long)obj+(unsigned long)atop(off)) & uvm.page_hashmask)
311
312 #define UVM_PAGEZERO_TARGET (uvmexp.free)
313
314 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
315
316 /*
317 * when VM_PHYSSEG_MAX is 1, we can simplify these functions
318 */
319
320 /*
321 * vm_physseg_find: find vm_physseg structure that belongs to a PA
322 */
323 static __inline int
vm_physseg_find(pframe,offp)324 vm_physseg_find(pframe, offp)
325 paddr_t pframe;
326 int *offp;
327 {
328 #if VM_PHYSSEG_MAX == 1
329
330 /* 'contig' case */
331 if (pframe >= vm_physmem[0].start && pframe < vm_physmem[0].end) {
332 if (offp)
333 *offp = pframe - vm_physmem[0].start;
334 return(0);
335 }
336 return(-1);
337
338 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH)
339 /* binary search for it */
340 int start, len, try;
341
342 /*
343 * if try is too large (thus target is less than than try) we reduce
344 * the length to trunc(len/2) [i.e. everything smaller than "try"]
345 *
346 * if the try is too small (thus target is greater than try) then
347 * we set the new start to be (try + 1). this means we need to
348 * reduce the length to (round(len/2) - 1).
349 *
350 * note "adjust" below which takes advantage of the fact that
351 * (round(len/2) - 1) == trunc((len - 1) / 2)
352 * for any value of len we may have
353 */
354
355 for (start = 0, len = vm_nphysseg ; len != 0 ; len = len / 2) {
356 try = start + (len / 2); /* try in the middle */
357
358 /* start past our try? */
359 if (pframe >= vm_physmem[try].start) {
360 /* was try correct? */
361 if (pframe < vm_physmem[try].end) {
362 if (offp)
363 *offp = pframe - vm_physmem[try].start;
364 return(try); /* got it */
365 }
366 start = try + 1; /* next time, start here */
367 len--; /* "adjust" */
368 } else {
369 /*
370 * pframe before try, just reduce length of
371 * region, done in "for" loop
372 */
373 }
374 }
375 return(-1);
376
377 #else
378 /* linear search for it */
379 int lcv;
380
381 for (lcv = 0; lcv < vm_nphysseg; lcv++) {
382 if (pframe >= vm_physmem[lcv].start &&
383 pframe < vm_physmem[lcv].end) {
384 if (offp)
385 *offp = pframe - vm_physmem[lcv].start;
386 return(lcv); /* got it */
387 }
388 }
389 return(-1);
390
391 #endif
392 }
393
394
395 /*
396 * IS_VM_PHYSADDR: only used my mips/pmax/pica trap/pmap.
397 */
398
399 #define IS_VM_PHYSADDR(PA) (vm_physseg_find(atop(PA), NULL) != -1)
400
401 /*
402 * PHYS_TO_VM_PAGE: find vm_page for a PA. used by MI code to get vm_pages
403 * back from an I/O mapping (ugh!). used in some MD code as well.
404 */
405 static __inline struct vm_page *
PHYS_TO_VM_PAGE(pa)406 PHYS_TO_VM_PAGE(pa)
407 paddr_t pa;
408 {
409 paddr_t pf = atop(pa);
410 int off;
411 int psi;
412
413 psi = vm_physseg_find(pf, &off);
414 if (psi != -1)
415 return(&vm_physmem[psi].pgs[off]);
416 return(NULL);
417 }
418
419 #define VM_PAGE_IS_FREE(entry) ((entry)->pqflags & PQ_FREE)
420
421 #endif /* _KERNEL */
422
423 #endif /* _UVM_UVM_PAGE_H_ */
424