xref: /freebsd/sys/vm/vm_page.c (revision 952d112864d8008aa87278a30a539d888a8493cd)
1 /*
2  * Copyright (c) 1991 Regents of the University of California.
3  * 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.c	7.4 (Berkeley) 5/7/91
37  *	$Id: vm_page.c,v 1.76 1997/02/22 09:48:31 peter Exp $
38  */
39 
40 /*
41  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
42  * All rights reserved.
43  *
44  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
45  *
46  * Permission to use, copy, modify and distribute this software and
47  * its documentation is hereby granted, provided that both the copyright
48  * notice and this permission notice appear in all copies of the
49  * software, derivative works or modified versions, and any portions
50  * thereof, and that both notices appear in supporting documentation.
51  *
52  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
53  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
54  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
55  *
56  * Carnegie Mellon requests users of this software to return to
57  *
58  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
59  *  School of Computer Science
60  *  Carnegie Mellon University
61  *  Pittsburgh PA 15213-3890
62  *
63  * any improvements or extensions that they make and grant Carnegie the
64  * rights to redistribute these changes.
65  */
66 
67 /*
68  *	Resident memory management module.
69  */
70 
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/malloc.h>
74 #include <sys/proc.h>
75 #include <sys/vmmeter.h>
76 
77 #include <vm/vm.h>
78 #include <vm/vm_param.h>
79 #include <vm/vm_prot.h>
80 #include <sys/lock.h>
81 #include <vm/vm_kern.h>
82 #include <vm/vm_object.h>
83 #include <vm/vm_page.h>
84 #include <vm/vm_map.h>
85 #include <vm/vm_pageout.h>
86 #include <vm/vm_extern.h>
87 
88 static void	vm_page_queue_init __P((void));
89 static vm_page_t vm_page_select_free __P((vm_object_t object,
90 			vm_pindex_t pindex, int prefqueue));
91 
92 /*
93  *	Associated with page of user-allocatable memory is a
94  *	page structure.
95  */
96 
97 static struct pglist *vm_page_buckets;	/* Array of buckets */
98 static int vm_page_bucket_count;	/* How big is array? */
99 static int vm_page_hash_mask;		/* Mask for hash function */
100 
101 struct pglist vm_page_queue_free[PQ_L2_SIZE] = {0};
102 struct pglist vm_page_queue_zero[PQ_L2_SIZE] = {0};
103 struct pglist vm_page_queue_active = {0};
104 struct pglist vm_page_queue_inactive = {0};
105 struct pglist vm_page_queue_cache[PQ_L2_SIZE] = {0};
106 
107 int no_queue=0;
108 
109 struct vpgqueues vm_page_queues[PQ_COUNT] = {0};
110 int pqcnt[PQ_COUNT] = {0};
111 
112 static void
113 vm_page_queue_init(void) {
114 	int i;
115 
116 	vm_page_queues[PQ_NONE].pl = NULL;
117 	vm_page_queues[PQ_NONE].cnt = &no_queue;
118 	for(i=0;i<PQ_L2_SIZE;i++) {
119 		vm_page_queues[PQ_FREE+i].pl = &vm_page_queue_free[i];
120 		vm_page_queues[PQ_FREE+i].cnt = &cnt.v_free_count;
121 	}
122 	for(i=0;i<PQ_L2_SIZE;i++) {
123 		vm_page_queues[PQ_ZERO+i].pl = &vm_page_queue_zero[i];
124 		vm_page_queues[PQ_ZERO+i].cnt = &cnt.v_free_count;
125 	}
126 	vm_page_queues[PQ_INACTIVE].pl = &vm_page_queue_inactive;
127 	vm_page_queues[PQ_INACTIVE].cnt = &cnt.v_inactive_count;
128 
129 	vm_page_queues[PQ_ACTIVE].pl = &vm_page_queue_active;
130 	vm_page_queues[PQ_ACTIVE].cnt = &cnt.v_active_count;
131 	for(i=0;i<PQ_L2_SIZE;i++) {
132 		vm_page_queues[PQ_CACHE+i].pl = &vm_page_queue_cache[i];
133 		vm_page_queues[PQ_CACHE+i].cnt = &cnt.v_cache_count;
134 	}
135 	for(i=0;i<PQ_COUNT;i++) {
136 		if (vm_page_queues[i].pl) {
137 			TAILQ_INIT(vm_page_queues[i].pl);
138 		} else if (i != 0) {
139 			panic("vm_page_queue_init: queue %d is null", i);
140 		}
141 		vm_page_queues[i].lcnt = &pqcnt[i];
142 	}
143 }
144 
145 vm_page_t vm_page_array = 0;
146 int vm_page_array_size = 0;
147 long first_page = 0;
148 static long last_page;
149 static vm_size_t page_mask;
150 static int page_shift;
151 int vm_page_zero_count = 0;
152 
153 /*
154  * map of contiguous valid DEV_BSIZE chunks in a page
155  * (this list is valid for page sizes upto 16*DEV_BSIZE)
156  */
157 static u_short vm_page_dev_bsize_chunks[] = {
158 	0x0, 0x1, 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff,
159 	0x1ff, 0x3ff, 0x7ff, 0xfff, 0x1fff, 0x3fff, 0x7fff, 0xffff
160 };
161 
162 static inline int vm_page_hash __P((vm_object_t object, vm_pindex_t pindex));
163 static int vm_page_freechk_and_unqueue __P((vm_page_t m));
164 static void vm_page_free_wakeup __P((void));
165 
166 /*
167  *	vm_set_page_size:
168  *
169  *	Sets the page size, perhaps based upon the memory
170  *	size.  Must be called before any use of page-size
171  *	dependent functions.
172  *
173  *	Sets page_shift and page_mask from cnt.v_page_size.
174  */
175 void
176 vm_set_page_size()
177 {
178 
179 	if (cnt.v_page_size == 0)
180 		cnt.v_page_size = DEFAULT_PAGE_SIZE;
181 	page_mask = cnt.v_page_size - 1;
182 	if ((page_mask & cnt.v_page_size) != 0)
183 		panic("vm_set_page_size: page size not a power of two");
184 	for (page_shift = 0;; page_shift++)
185 		if ((1 << page_shift) == cnt.v_page_size)
186 			break;
187 }
188 
189 /*
190  *	vm_page_startup:
191  *
192  *	Initializes the resident memory module.
193  *
194  *	Allocates memory for the page cells, and
195  *	for the object/offset-to-page hash table headers.
196  *	Each page cell is initialized and placed on the free list.
197  */
198 
199 vm_offset_t
200 vm_page_startup(starta, enda, vaddr)
201 	register vm_offset_t starta;
202 	vm_offset_t enda;
203 	register vm_offset_t vaddr;
204 {
205 	register vm_offset_t mapped;
206 	register vm_page_t m;
207 	register struct pglist *bucket;
208 	vm_size_t npages, page_range;
209 	register vm_offset_t new_start;
210 	int i;
211 	vm_offset_t pa;
212 	int nblocks;
213 	vm_offset_t first_managed_page;
214 
215 	/* the biggest memory array is the second group of pages */
216 	vm_offset_t start;
217 	vm_offset_t biggestone, biggestsize;
218 
219 	vm_offset_t total;
220 
221 	total = 0;
222 	biggestsize = 0;
223 	biggestone = 0;
224 	nblocks = 0;
225 	vaddr = round_page(vaddr);
226 
227 	for (i = 0; phys_avail[i + 1]; i += 2) {
228 		phys_avail[i] = round_page(phys_avail[i]);
229 		phys_avail[i + 1] = trunc_page(phys_avail[i + 1]);
230 	}
231 
232 	for (i = 0; phys_avail[i + 1]; i += 2) {
233 		int size = phys_avail[i + 1] - phys_avail[i];
234 
235 		if (size > biggestsize) {
236 			biggestone = i;
237 			biggestsize = size;
238 		}
239 		++nblocks;
240 		total += size;
241 	}
242 
243 	start = phys_avail[biggestone];
244 
245 	/*
246 	 * Initialize the queue headers for the free queue, the active queue
247 	 * and the inactive queue.
248 	 */
249 
250 	vm_page_queue_init();
251 
252 	/*
253 	 * Allocate (and initialize) the hash table buckets.
254 	 *
255 	 * The number of buckets MUST BE a power of 2, and the actual value is
256 	 * the next power of 2 greater than the number of physical pages in
257 	 * the system.
258 	 *
259 	 * Note: This computation can be tweaked if desired.
260 	 */
261 	vm_page_buckets = (struct pglist *) vaddr;
262 	bucket = vm_page_buckets;
263 	if (vm_page_bucket_count == 0) {
264 		vm_page_bucket_count = 1;
265 		while (vm_page_bucket_count < atop(total))
266 			vm_page_bucket_count <<= 1;
267 	}
268 	vm_page_hash_mask = vm_page_bucket_count - 1;
269 
270 	/*
271 	 * Validate these addresses.
272 	 */
273 
274 	new_start = start + vm_page_bucket_count * sizeof(struct pglist);
275 	new_start = round_page(new_start);
276 	mapped = vaddr;
277 	vaddr = pmap_map(mapped, start, new_start,
278 	    VM_PROT_READ | VM_PROT_WRITE);
279 	start = new_start;
280 	bzero((caddr_t) mapped, vaddr - mapped);
281 	mapped = vaddr;
282 
283 	for (i = 0; i < vm_page_bucket_count; i++) {
284 		TAILQ_INIT(bucket);
285 		bucket++;
286 	}
287 
288 	/*
289 	 * round (or truncate) the addresses to our page size.
290 	 */
291 
292 	/*
293 	 * Pre-allocate maps and map entries that cannot be dynamically
294 	 * allocated via malloc().  The maps include the kernel_map and
295 	 * kmem_map which must be initialized before malloc() will work
296 	 * (obviously).  Also could include pager maps which would be
297 	 * allocated before kmeminit.
298 	 *
299 	 * Allow some kernel map entries... this should be plenty since people
300 	 * shouldn't be cluttering up the kernel map (they should use their
301 	 * own maps).
302 	 */
303 
304 	kentry_data_size = MAX_KMAP * sizeof(struct vm_map) +
305 	    MAX_KMAPENT * sizeof(struct vm_map_entry);
306 	kentry_data_size = round_page(kentry_data_size);
307 	kentry_data = (vm_offset_t) vaddr;
308 	vaddr += kentry_data_size;
309 
310 	/*
311 	 * Validate these zone addresses.
312 	 */
313 
314 	new_start = start + (vaddr - mapped);
315 	pmap_map(mapped, start, new_start, VM_PROT_READ | VM_PROT_WRITE);
316 	bzero((caddr_t) mapped, (vaddr - mapped));
317 	start = round_page(new_start);
318 
319 	/*
320 	 * Compute the number of pages of memory that will be available for
321 	 * use (taking into account the overhead of a page structure per
322 	 * page).
323 	 */
324 
325 	first_page = phys_avail[0] / PAGE_SIZE;
326 	last_page = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE;
327 
328 	page_range = last_page - (phys_avail[0] / PAGE_SIZE);
329 	npages = (total - (page_range * sizeof(struct vm_page)) -
330 	    (start - phys_avail[biggestone])) / PAGE_SIZE;
331 
332 	/*
333 	 * Initialize the mem entry structures now, and put them in the free
334 	 * queue.
335 	 */
336 
337 	vm_page_array = (vm_page_t) vaddr;
338 	mapped = vaddr;
339 
340 	/*
341 	 * Validate these addresses.
342 	 */
343 
344 	new_start = round_page(start + page_range * sizeof(struct vm_page));
345 	mapped = pmap_map(mapped, start, new_start,
346 	    VM_PROT_READ | VM_PROT_WRITE);
347 	start = new_start;
348 
349 	first_managed_page = start / PAGE_SIZE;
350 
351 	/*
352 	 * Clear all of the page structures
353 	 */
354 	bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page));
355 	vm_page_array_size = page_range;
356 
357 	cnt.v_page_count = 0;
358 	cnt.v_free_count = 0;
359 	for (i = 0; phys_avail[i + 1] && npages > 0; i += 2) {
360 		if (i == biggestone)
361 			pa = ptoa(first_managed_page);
362 		else
363 			pa = phys_avail[i];
364 		while (pa < phys_avail[i + 1] && npages-- > 0) {
365 			++cnt.v_page_count;
366 			++cnt.v_free_count;
367 			m = PHYS_TO_VM_PAGE(pa);
368 			m->phys_addr = pa;
369 			m->flags = 0;
370 			m->pc = (pa >> PAGE_SHIFT) & PQ_L2_MASK;
371 			m->queue = PQ_FREE + m->pc;
372 			TAILQ_INSERT_TAIL(vm_page_queues[m->queue].pl, m, pageq);
373 			++(*vm_page_queues[m->queue].lcnt);
374 			pa += PAGE_SIZE;
375 		}
376 	}
377 
378 	return (mapped);
379 }
380 
381 /*
382  *	vm_page_hash:
383  *
384  *	Distributes the object/offset key pair among hash buckets.
385  *
386  *	NOTE:  This macro depends on vm_page_bucket_count being a power of 2.
387  */
388 static inline int
389 vm_page_hash(object, pindex)
390 	vm_object_t object;
391 	vm_pindex_t pindex;
392 {
393 	return ((((unsigned) object) >> 5) + (pindex >> 1)) & vm_page_hash_mask;
394 }
395 
396 /*
397  *	vm_page_insert:		[ internal use only ]
398  *
399  *	Inserts the given mem entry into the object/object-page
400  *	table and object list.
401  *
402  *	The object and page must be locked, and must be splhigh.
403  */
404 
405 void
406 vm_page_insert(m, object, pindex)
407 	register vm_page_t m;
408 	register vm_object_t object;
409 	register vm_pindex_t pindex;
410 {
411 	register struct pglist *bucket;
412 
413 	if (m->flags & PG_TABLED)
414 		panic("vm_page_insert: already inserted");
415 
416 	/*
417 	 * Record the object/offset pair in this page
418 	 */
419 
420 	m->object = object;
421 	m->pindex = pindex;
422 
423 	/*
424 	 * Insert it into the object_object/offset hash table
425 	 */
426 
427 	bucket = &vm_page_buckets[vm_page_hash(object, pindex)];
428 	TAILQ_INSERT_TAIL(bucket, m, hashq);
429 
430 	/*
431 	 * Now link into the object's list of backed pages.
432 	 */
433 
434 	TAILQ_INSERT_TAIL(&object->memq, m, listq);
435 	m->flags |= PG_TABLED;
436 	m->object->page_hint = m;
437 
438 	/*
439 	 * And show that the object has one more resident page.
440 	 */
441 
442 	object->resident_page_count++;
443 }
444 
445 /*
446  *	vm_page_remove:		[ internal use only ]
447  *				NOTE: used by device pager as well -wfj
448  *
449  *	Removes the given mem entry from the object/offset-page
450  *	table and the object page list.
451  *
452  *	The object and page must be locked, and at splhigh.
453  */
454 
455 void
456 vm_page_remove(m)
457 	register vm_page_t m;
458 {
459 	register struct pglist *bucket;
460 
461 	if (!(m->flags & PG_TABLED))
462 		return;
463 
464 	if (m->object->page_hint == m)
465 		m->object->page_hint = NULL;
466 
467 	/*
468 	 * Remove from the object_object/offset hash table
469 	 */
470 
471 	bucket = &vm_page_buckets[vm_page_hash(m->object, m->pindex)];
472 	TAILQ_REMOVE(bucket, m, hashq);
473 
474 	/*
475 	 * Now remove from the object's list of backed pages.
476 	 */
477 
478 	TAILQ_REMOVE(&m->object->memq, m, listq);
479 
480 	/*
481 	 * And show that the object has one fewer resident page.
482 	 */
483 
484 	m->object->resident_page_count--;
485 
486 	m->flags &= ~PG_TABLED;
487 }
488 
489 /*
490  *	vm_page_lookup:
491  *
492  *	Returns the page associated with the object/offset
493  *	pair specified; if none is found, NULL is returned.
494  *
495  *	The object must be locked.  No side effects.
496  */
497 
498 vm_page_t
499 vm_page_lookup(object, pindex)
500 	register vm_object_t object;
501 	register vm_pindex_t pindex;
502 {
503 	register vm_page_t m;
504 	register struct pglist *bucket;
505 	int s;
506 
507 	/*
508 	 * Search the hash table for this object/offset pair
509 	 */
510 
511 	bucket = &vm_page_buckets[vm_page_hash(object, pindex)];
512 
513 	s = splvm();
514 	for (m = TAILQ_FIRST(bucket); m != NULL; m = TAILQ_NEXT(m,hashq)) {
515 		if ((m->object == object) && (m->pindex == pindex)) {
516 			splx(s);
517 			m->object->page_hint = m;
518 			return (m);
519 		}
520 	}
521 	splx(s);
522 	return (NULL);
523 }
524 
525 /*
526  *	vm_page_rename:
527  *
528  *	Move the given memory entry from its
529  *	current object to the specified target object/offset.
530  *
531  *	The object must be locked.
532  */
533 void
534 vm_page_rename(m, new_object, new_pindex)
535 	register vm_page_t m;
536 	register vm_object_t new_object;
537 	vm_pindex_t new_pindex;
538 {
539 	int s;
540 
541 	s = splvm();
542 	vm_page_remove(m);
543 	vm_page_insert(m, new_object, new_pindex);
544 	splx(s);
545 }
546 
547 /*
548  * vm_page_unqueue without any wakeup
549  */
550 void
551 vm_page_unqueue_nowakeup(m)
552 	vm_page_t m;
553 {
554 	int queue = m->queue;
555 	struct vpgqueues *pq;
556 	if (queue != PQ_NONE) {
557 		pq = &vm_page_queues[queue];
558 		m->queue = PQ_NONE;
559 		TAILQ_REMOVE(pq->pl, m, pageq);
560 		--(*pq->cnt);
561 		--(*pq->lcnt);
562 	}
563 }
564 
565 /*
566  * vm_page_unqueue must be called at splhigh();
567  */
568 void
569 vm_page_unqueue(m)
570 	vm_page_t m;
571 {
572 	int queue = m->queue;
573 	struct vpgqueues *pq;
574 	if (queue != PQ_NONE) {
575 		m->queue = PQ_NONE;
576 		pq = &vm_page_queues[queue];
577 		TAILQ_REMOVE(pq->pl, m, pageq);
578 		--(*pq->cnt);
579 		--(*pq->lcnt);
580 		if ((m->queue - m->pc) == PQ_CACHE) {
581 			if ((cnt.v_cache_count + cnt.v_free_count) <
582 				(cnt.v_free_reserved + cnt.v_cache_min))
583 				pagedaemon_wakeup();
584 		}
585 	}
586 }
587 
588 /*
589  * Find a page on the specified queue with color optimization.
590  */
591 vm_page_t
592 vm_page_list_find(basequeue, index)
593 	int basequeue, index;
594 {
595 #if PQ_L2_SIZE > 1
596 
597 	int i,j;
598 	vm_page_t m;
599 	int hindex;
600 
601 	for(j = 0; j < PQ_L1_SIZE; j++) {
602 		for(i = (PQ_L2_SIZE/2) - (PQ_L1_SIZE - 1);
603 			i >= 0;
604 			i -= PQ_L1_SIZE) {
605 			hindex = (index + (i+j)) & PQ_L2_MASK;
606 			m = TAILQ_FIRST(vm_page_queues[basequeue + hindex].pl);
607 			if (m)
608 				return m;
609 
610 			hindex = (index - (i+j)) & PQ_L2_MASK;
611 			m = TAILQ_FIRST(vm_page_queues[basequeue + hindex].pl);
612 			if (m)
613 				return m;
614 		}
615 	}
616 	return NULL;
617 #else
618 	return TAILQ_FIRST(vm_page_queues[basequeue].pl);
619 #endif
620 
621 }
622 
623 /*
624  * Find a page on the specified queue with color optimization.
625  */
626 vm_page_t
627 vm_page_select(object, pindex, basequeue)
628 	vm_object_t object;
629 	vm_pindex_t pindex;
630 	int basequeue;
631 {
632 
633 #if PQ_L2_SIZE > 1
634 	int index;
635 	index = (pindex + object->pg_color) & PQ_L2_MASK;
636 	return vm_page_list_find(basequeue, index);
637 
638 #else
639 	return TAILQ_FIRST(vm_page_queues[basequeue].pl);
640 #endif
641 
642 }
643 
644 /*
645  * Find a free or zero page, with specified preference.
646  */
647 static vm_page_t
648 vm_page_select_free(object, pindex, prefqueue)
649 	vm_object_t object;
650 	vm_pindex_t pindex;
651 	int prefqueue;
652 {
653 #if PQ_L2_SIZE > 1
654 	int i,j;
655 	int index, hindex;
656 #endif
657 	vm_page_t m;
658 	int oqueuediff;
659 
660 	if (prefqueue == PQ_ZERO)
661 		oqueuediff = PQ_FREE - PQ_ZERO;
662 	else
663 		oqueuediff = PQ_ZERO - PQ_FREE;
664 
665 	if (object->page_hint) {
666 		 if (object->page_hint->pindex == (pindex - 1)) {
667 			vm_offset_t last_phys;
668 			if ((object->page_hint->flags & PG_FICTITIOUS) == 0) {
669 				if ((object->page_hint < &vm_page_array[cnt.v_page_count-1]) &&
670 					(object->page_hint >= &vm_page_array[0])) {
671 					int queue;
672 					last_phys = VM_PAGE_TO_PHYS(object->page_hint);
673 					m = PHYS_TO_VM_PAGE(last_phys + PAGE_SIZE);
674 					queue = m->queue - m->pc;
675 					if (queue == PQ_FREE || queue == PQ_ZERO) {
676 						return m;
677 					}
678 				}
679 			}
680 		}
681 	}
682 
683 
684 #if PQ_L2_SIZE > 1
685 
686 	index = pindex + object->pg_color;
687 	for(j = 0; j < PQ_L1_SIZE; j++) {
688 		for(i = (PQ_L2_SIZE/2) - (PQ_L1_SIZE - 1);
689 			(i + j) >= 0;
690 			i -= PQ_L1_SIZE) {
691 
692 			hindex = prefqueue + ((index + (i+j)) & PQ_L2_MASK);
693 			if (m = TAILQ_FIRST(vm_page_queues[hindex].pl))
694 				return m;
695 			if (m = TAILQ_FIRST(vm_page_queues[hindex + oqueuediff].pl))
696 				return m;
697 
698 			hindex = prefqueue + ((index - (i+j)) & PQ_L2_MASK);
699 			if (m = TAILQ_FIRST(vm_page_queues[hindex].pl))
700 				return m;
701 			if (m = TAILQ_FIRST(vm_page_queues[hindex + oqueuediff].pl))
702 				return m;
703 		}
704 	}
705 #else
706 	if (m = TAILQ_FIRST(vm_page_queues[prefqueue].pl))
707 		return m;
708 	else
709 		return TAILQ_FIRST(vm_page_queues[prefqueue + oqueuediff].pl);
710 #endif
711 
712 	return NULL;
713 }
714 
715 /*
716  *	vm_page_alloc:
717  *
718  *	Allocate and return a memory cell associated
719  *	with this VM object/offset pair.
720  *
721  *	page_req classes:
722  *	VM_ALLOC_NORMAL		normal process request
723  *	VM_ALLOC_SYSTEM		system *really* needs a page
724  *	VM_ALLOC_INTERRUPT	interrupt time request
725  *	VM_ALLOC_ZERO		zero page
726  *
727  *	Object must be locked.
728  */
729 vm_page_t
730 vm_page_alloc(object, pindex, page_req)
731 	vm_object_t object;
732 	vm_pindex_t pindex;
733 	int page_req;
734 {
735 	register vm_page_t m;
736 	struct vpgqueues *pq;
737 	int queue, qtype;
738 	int s;
739 
740 #ifdef DIAGNOSTIC
741 	m = vm_page_lookup(object, pindex);
742 	if (m)
743 		panic("vm_page_alloc: page already allocated");
744 #endif
745 
746 	if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) {
747 		page_req = VM_ALLOC_SYSTEM;
748 	};
749 
750 	s = splvm();
751 
752 	switch (page_req) {
753 
754 	case VM_ALLOC_NORMAL:
755 		if (cnt.v_free_count >= cnt.v_free_reserved) {
756 			m = vm_page_select_free(object, pindex, PQ_FREE);
757 #if defined(DIAGNOSTIC)
758 			if (m == NULL)
759 				panic("vm_page_alloc(NORMAL): missing page on free queue\n");
760 #endif
761 		} else {
762 			m = vm_page_select(object, pindex, PQ_CACHE);
763 			if (m == NULL) {
764 				splx(s);
765 #if defined(DIAGNOSTIC)
766 				if (cnt.v_cache_count > 0)
767 					printf("vm_page_alloc(NORMAL): missing pages on cache queue: %d\n", cnt.v_cache_count);
768 #endif
769 				pagedaemon_wakeup();
770 				return (NULL);
771 			}
772 		}
773 		break;
774 
775 	case VM_ALLOC_ZERO:
776 		if (cnt.v_free_count >= cnt.v_free_reserved) {
777 			m = vm_page_select_free(object, pindex, PQ_ZERO);
778 #if defined(DIAGNOSTIC)
779 			if (m == NULL)
780 				panic("vm_page_alloc(ZERO): missing page on free queue\n");
781 #endif
782 		} else {
783 			m = vm_page_select(object, pindex, PQ_CACHE);
784 			if (m == NULL) {
785 				splx(s);
786 #if defined(DIAGNOSTIC)
787 				if (cnt.v_cache_count > 0)
788 					printf("vm_page_alloc(ZERO): missing pages on cache queue: %d\n", cnt.v_cache_count);
789 #endif
790 				pagedaemon_wakeup();
791 				return (NULL);
792 			}
793 		}
794 		break;
795 
796 	case VM_ALLOC_SYSTEM:
797 		if ((cnt.v_free_count >= cnt.v_free_reserved) ||
798 		    ((cnt.v_cache_count == 0) &&
799 		    (cnt.v_free_count >= cnt.v_interrupt_free_min))) {
800 			m = vm_page_select_free(object, pindex, PQ_FREE);
801 #if defined(DIAGNOSTIC)
802 			if (m == NULL)
803 				panic("vm_page_alloc(SYSTEM): missing page on free queue\n");
804 #endif
805 		} else {
806 			m = vm_page_select(object, pindex, PQ_CACHE);
807 			if (m == NULL) {
808 				splx(s);
809 #if defined(DIAGNOSTIC)
810 				if (cnt.v_cache_count > 0)
811 					printf("vm_page_alloc(SYSTEM): missing pages on cache queue: %d\n", cnt.v_cache_count);
812 #endif
813 				pagedaemon_wakeup();
814 				return (NULL);
815 			}
816 		}
817 		break;
818 
819 	case VM_ALLOC_INTERRUPT:
820 		if (cnt.v_free_count > 0) {
821 			m = vm_page_select_free(object, pindex, PQ_FREE);
822 #if defined(DIAGNOSTIC)
823 			if (m == NULL)
824 				panic("vm_page_alloc(INTERRUPT): missing page on free queue\n");
825 #endif
826 		} else {
827 			splx(s);
828 			pagedaemon_wakeup();
829 			return (NULL);
830 		}
831 		break;
832 
833 	default:
834 		panic("vm_page_alloc: invalid allocation class");
835 	}
836 
837 	queue = m->queue;
838 	qtype = queue - m->pc;
839 	if (qtype == PQ_ZERO)
840 		--vm_page_zero_count;
841 	pq = &vm_page_queues[queue];
842 	TAILQ_REMOVE(pq->pl, m, pageq);
843 	--(*pq->cnt);
844 	--(*pq->lcnt);
845 	if (qtype == PQ_ZERO) {
846 		m->flags = PG_ZERO|PG_BUSY;
847 	} else if (qtype == PQ_CACHE) {
848 		vm_page_remove(m);
849 		m->flags = PG_BUSY;
850 	} else {
851 		m->flags = PG_BUSY;
852 	}
853 	m->wire_count = 0;
854 	m->hold_count = 0;
855 	m->act_count = 0;
856 	m->busy = 0;
857 	m->valid = 0;
858 	m->dirty = 0;
859 	m->queue = PQ_NONE;
860 
861 	/* XXX before splx until vm_page_insert is safe */
862 	vm_page_insert(m, object, pindex);
863 
864 	splx(s);
865 
866 	/*
867 	 * Don't wakeup too often - wakeup the pageout daemon when
868 	 * we would be nearly out of memory.
869 	 */
870 	if (((cnt.v_free_count + cnt.v_cache_count) <
871 		(cnt.v_free_reserved + cnt.v_cache_min)) ||
872 			(cnt.v_free_count < cnt.v_pageout_free_min))
873 		pagedaemon_wakeup();
874 
875 	return (m);
876 }
877 
878 void
879 vm_wait()
880 {
881 	int s;
882 
883 	s = splvm();
884 	if (curproc == pageproc) {
885 		vm_pageout_pages_needed = 1;
886 		tsleep(&vm_pageout_pages_needed, PSWP, "vmwait", 0);
887 	} else {
888 		if (!vm_pages_needed) {
889 			vm_pages_needed++;
890 			wakeup(&vm_pages_needed);
891 		}
892 		tsleep(&cnt.v_free_count, PVM, "vmwait", 0);
893 	}
894 	splx(s);
895 }
896 
897 
898 /*
899  *	vm_page_activate:
900  *
901  *	Put the specified page on the active list (if appropriate).
902  *
903  *	The page queues must be locked.
904  */
905 void
906 vm_page_activate(m)
907 	register vm_page_t m;
908 {
909 	int s;
910 
911 	s = splvm();
912 	if (m->queue == PQ_ACTIVE)
913 		panic("vm_page_activate: already active");
914 
915 	if ((m->queue - m->pc) == PQ_CACHE)
916 		cnt.v_reactivated++;
917 
918 	vm_page_unqueue(m);
919 
920 	if (m->wire_count == 0) {
921 		m->queue = PQ_ACTIVE;
922 		++(*vm_page_queues[PQ_ACTIVE].lcnt);
923 		TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq);
924 		if (m->act_count < ACT_INIT)
925 			m->act_count = ACT_INIT;
926 		cnt.v_active_count++;
927 	}
928 	splx(s);
929 }
930 
931 /*
932  * helper routine for vm_page_free and vm_page_free_zero
933  */
934 static int
935 vm_page_freechk_and_unqueue(m)
936 	vm_page_t m;
937 {
938 	if (m->busy ||
939 		(m->flags & PG_BUSY) ||
940 		((m->queue - m->pc) == PQ_FREE) ||
941 		(m->hold_count != 0)) {
942 		printf("vm_page_free: pindex(%ld), busy(%d), PG_BUSY(%d), hold(%d)\n",
943 			m->pindex, m->busy,
944 			(m->flags & PG_BUSY) ? 1 : 0, m->hold_count);
945 		if ((m->queue - m->pc) == PQ_FREE)
946 			panic("vm_page_free: freeing free page");
947 		else
948 			panic("vm_page_free: freeing busy page");
949 	}
950 
951 	vm_page_remove(m);
952 	vm_page_unqueue_nowakeup(m);
953 	if ((m->flags & PG_FICTITIOUS) != 0) {
954 		return 0;
955 	}
956 	if (m->wire_count != 0) {
957 		if (m->wire_count > 1) {
958 			panic("vm_page_free: invalid wire count (%d), pindex: 0x%x",
959 				m->wire_count, m->pindex);
960 		}
961 		m->wire_count = 0;
962 		cnt.v_wire_count--;
963 	}
964 
965 	return 1;
966 }
967 
968 /*
969  * helper routine for vm_page_free and vm_page_free_zero
970  */
971 static __inline void
972 vm_page_free_wakeup()
973 {
974 
975 /*
976  * if pageout daemon needs pages, then tell it that there are
977  * some free.
978  */
979 	if (vm_pageout_pages_needed) {
980 		wakeup(&vm_pageout_pages_needed);
981 		vm_pageout_pages_needed = 0;
982 	}
983 	/*
984 	 * wakeup processes that are waiting on memory if we hit a
985 	 * high water mark. And wakeup scheduler process if we have
986 	 * lots of memory. this process will swapin processes.
987 	 */
988 	if (vm_pages_needed &&
989 		((cnt.v_free_count + cnt.v_cache_count) >= cnt.v_free_min)) {
990 		wakeup(&cnt.v_free_count);
991 		vm_pages_needed = 0;
992 	}
993 }
994 
995 /*
996  *	vm_page_free:
997  *
998  *	Returns the given page to the free list,
999  *	disassociating it with any VM object.
1000  *
1001  *	Object and page must be locked prior to entry.
1002  */
1003 void
1004 vm_page_free(m)
1005 	register vm_page_t m;
1006 {
1007 	int s;
1008 	struct vpgqueues *pq;
1009 
1010 	s = splvm();
1011 
1012 	cnt.v_tfree++;
1013 
1014 	if (!vm_page_freechk_and_unqueue(m)) {
1015 		splx(s);
1016 		return;
1017 	}
1018 
1019 	m->queue = PQ_FREE + m->pc;
1020 	pq = &vm_page_queues[m->queue];
1021 	++(*pq->lcnt);
1022 	++(*pq->cnt);
1023 	/*
1024 	 * If the pageout process is grabbing the page, it is likely
1025 	 * that the page is NOT in the cache.  It is more likely that
1026 	 * the page will be partially in the cache if it is being
1027 	 * explicitly freed.
1028 	 */
1029 	if (curproc == pageproc) {
1030 		TAILQ_INSERT_TAIL(pq->pl, m, pageq);
1031 	} else {
1032 		TAILQ_INSERT_HEAD(pq->pl, m, pageq);
1033 	}
1034 	vm_page_free_wakeup();
1035 	splx(s);
1036 }
1037 
1038 void
1039 vm_page_free_zero(m)
1040 	register vm_page_t m;
1041 {
1042 	int s;
1043 	struct vpgqueues *pq;
1044 
1045 	s = splvm();
1046 
1047 	cnt.v_tfree++;
1048 
1049 	if (!vm_page_freechk_and_unqueue(m)) {
1050 		splx(s);
1051 		return;
1052 	}
1053 
1054 	m->queue = PQ_ZERO + m->pc;
1055 	pq = &vm_page_queues[m->queue];
1056 	++(*pq->lcnt);
1057 	++(*pq->cnt);
1058 
1059 	TAILQ_INSERT_HEAD(pq->pl, m, pageq);
1060 	++vm_page_zero_count;
1061 	vm_page_free_wakeup();
1062 	splx(s);
1063 }
1064 
1065 /*
1066  *	vm_page_wire:
1067  *
1068  *	Mark this page as wired down by yet
1069  *	another map, removing it from paging queues
1070  *	as necessary.
1071  *
1072  *	The page queues must be locked.
1073  */
1074 void
1075 vm_page_wire(m)
1076 	register vm_page_t m;
1077 {
1078 	int s;
1079 
1080 	if (m->wire_count == 0) {
1081 		s = splvm();
1082 		vm_page_unqueue(m);
1083 		splx(s);
1084 		cnt.v_wire_count++;
1085 	}
1086 	++(*vm_page_queues[PQ_NONE].lcnt);
1087 	m->wire_count++;
1088 	m->flags |= PG_MAPPED;
1089 }
1090 
1091 /*
1092  *	vm_page_unwire:
1093  *
1094  *	Release one wiring of this page, potentially
1095  *	enabling it to be paged again.
1096  *
1097  *	The page queues must be locked.
1098  */
1099 void
1100 vm_page_unwire(m)
1101 	register vm_page_t m;
1102 {
1103 	int s;
1104 
1105 	s = splvm();
1106 
1107 	if (m->wire_count > 0)
1108 		m->wire_count--;
1109 
1110 	if (m->wire_count == 0) {
1111 		cnt.v_wire_count--;
1112 		TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq);
1113 		m->queue = PQ_ACTIVE;
1114 		++(*vm_page_queues[PQ_ACTIVE].lcnt);
1115 		cnt.v_active_count++;
1116 	}
1117 	splx(s);
1118 }
1119 
1120 
1121 /*
1122  *	vm_page_deactivate:
1123  *
1124  *	Returns the given page to the inactive list,
1125  *	indicating that no physical maps have access
1126  *	to this page.  [Used by the physical mapping system.]
1127  *
1128  *	The page queues must be locked.
1129  */
1130 void
1131 vm_page_deactivate(m)
1132 	register vm_page_t m;
1133 {
1134 	int s;
1135 
1136 	/*
1137 	 * Only move active pages -- ignore locked or already inactive ones.
1138 	 *
1139 	 * XXX: sometimes we get pages which aren't wired down or on any queue -
1140 	 * we need to put them on the inactive queue also, otherwise we lose
1141 	 * track of them. Paul Mackerras (paulus@cs.anu.edu.au) 9-Jan-93.
1142 	 */
1143 	if (m->queue == PQ_INACTIVE)
1144 		return;
1145 
1146 	s = splvm();
1147 	if (m->wire_count == 0 && m->hold_count == 0) {
1148 		if ((m->queue - m->pc) == PQ_CACHE)
1149 			cnt.v_reactivated++;
1150 		vm_page_unqueue(m);
1151 		TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq);
1152 		m->queue = PQ_INACTIVE;
1153 		++(*vm_page_queues[PQ_INACTIVE].lcnt);
1154 		cnt.v_inactive_count++;
1155 	}
1156 	splx(s);
1157 }
1158 
1159 /*
1160  * vm_page_cache
1161  *
1162  * Put the specified page onto the page cache queue (if appropriate).
1163  */
1164 void
1165 vm_page_cache(m)
1166 	register vm_page_t m;
1167 {
1168 	int s;
1169 
1170 	if ((m->flags & PG_BUSY) || m->busy || m->wire_count) {
1171 		printf("vm_page_cache: attempting to cache busy page\n");
1172 		return;
1173 	}
1174 	if ((m->queue - m->pc) == PQ_CACHE)
1175 		return;
1176 
1177 	vm_page_protect(m, VM_PROT_NONE);
1178 	if (m->dirty != 0) {
1179 		panic("vm_page_cache: caching a dirty page, pindex: %d", m->pindex);
1180 	}
1181 	s = splvm();
1182 	vm_page_unqueue_nowakeup(m);
1183 	m->queue = PQ_CACHE + m->pc;
1184 	++(*vm_page_queues[m->queue].lcnt);
1185 	TAILQ_INSERT_TAIL(vm_page_queues[m->queue].pl, m, pageq);
1186 	cnt.v_cache_count++;
1187 	vm_page_free_wakeup();
1188 	splx(s);
1189 }
1190 
1191 
1192 /*
1193  * mapping function for valid bits or for dirty bits in
1194  * a page
1195  */
1196 inline int
1197 vm_page_bits(int base, int size)
1198 {
1199 	u_short chunk;
1200 
1201 	if ((base == 0) && (size >= PAGE_SIZE))
1202 		return VM_PAGE_BITS_ALL;
1203 	size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1);
1204 	base = (base % PAGE_SIZE) / DEV_BSIZE;
1205 	chunk = vm_page_dev_bsize_chunks[size / DEV_BSIZE];
1206 	return (chunk << base) & VM_PAGE_BITS_ALL;
1207 }
1208 
1209 /*
1210  * set a page valid and clean
1211  */
1212 void
1213 vm_page_set_validclean(m, base, size)
1214 	vm_page_t m;
1215 	int base;
1216 	int size;
1217 {
1218 	int pagebits = vm_page_bits(base, size);
1219 	m->valid |= pagebits;
1220 	m->dirty &= ~pagebits;
1221 	if( base == 0 && size == PAGE_SIZE)
1222 		pmap_clear_modify(VM_PAGE_TO_PHYS(m));
1223 }
1224 
1225 /*
1226  * set a page (partially) invalid
1227  */
1228 void
1229 vm_page_set_invalid(m, base, size)
1230 	vm_page_t m;
1231 	int base;
1232 	int size;
1233 {
1234 	int bits;
1235 
1236 	m->valid &= ~(bits = vm_page_bits(base, size));
1237 	if (m->valid == 0)
1238 		m->dirty &= ~bits;
1239 }
1240 
1241 /*
1242  * is (partial) page valid?
1243  */
1244 int
1245 vm_page_is_valid(m, base, size)
1246 	vm_page_t m;
1247 	int base;
1248 	int size;
1249 {
1250 	int bits = vm_page_bits(base, size);
1251 
1252 	if (m->valid && ((m->valid & bits) == bits))
1253 		return 1;
1254 	else
1255 		return 0;
1256 }
1257 
1258 void
1259 vm_page_test_dirty(m)
1260 	vm_page_t m;
1261 {
1262 	if ((m->dirty != VM_PAGE_BITS_ALL) &&
1263 	    pmap_is_modified(VM_PAGE_TO_PHYS(m))) {
1264 		m->dirty = VM_PAGE_BITS_ALL;
1265 	}
1266 }
1267 
1268 /*
1269  * This interface is for merging with malloc() someday.
1270  * Even if we never implement compaction so that contiguous allocation
1271  * works after initialization time, malloc()'s data structures are good
1272  * for statistics and for allocations of less than a page.
1273  */
1274 void *
1275 contigmalloc1(size, type, flags, low, high, alignment, boundary, map)
1276 	unsigned long size;	/* should be size_t here and for malloc() */
1277 	int type;
1278 	int flags;
1279 	unsigned long low;
1280 	unsigned long high;
1281 	unsigned long alignment;
1282 	unsigned long boundary;
1283 	vm_map_t map;
1284 {
1285 	int i, s, start;
1286 	vm_offset_t addr, phys, tmp_addr;
1287 	int pass;
1288 	vm_page_t pga = vm_page_array;
1289 
1290 	size = round_page(size);
1291 	if (size == 0)
1292 		panic("vm_page_alloc_contig: size must not be 0");
1293 	if ((alignment & (alignment - 1)) != 0)
1294 		panic("vm_page_alloc_contig: alignment must be a power of 2");
1295 	if ((boundary & (boundary - 1)) != 0)
1296 		panic("vm_page_alloc_contig: boundary must be a power of 2");
1297 
1298 	start = 0;
1299 	for (pass = 0; pass <= 1; pass++) {
1300 		s = splvm();
1301 again:
1302 		/*
1303 		 * Find first page in array that is free, within range, aligned, and
1304 		 * such that the boundary won't be crossed.
1305 		 */
1306 		for (i = start; i < cnt.v_page_count; i++) {
1307 			int pqtype;
1308 			phys = VM_PAGE_TO_PHYS(&pga[i]);
1309 			pqtype = pga[i].queue - pga[i].pc;
1310 			if (((pqtype == PQ_ZERO) || (pqtype == PQ_FREE) || (pqtype == PQ_CACHE)) &&
1311 			    (phys >= low) && (phys < high) &&
1312 			    ((phys & (alignment - 1)) == 0) &&
1313 			    (((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0))
1314 				break;
1315 		}
1316 
1317 		/*
1318 		 * If the above failed or we will exceed the upper bound, fail.
1319 		 */
1320 		if ((i == cnt.v_page_count) ||
1321 			((VM_PAGE_TO_PHYS(&pga[i]) + size) > high)) {
1322 			vm_page_t m, next;
1323 
1324 again1:
1325 			for (m = TAILQ_FIRST(&vm_page_queue_inactive);
1326 				m != NULL;
1327 				m = next) {
1328 
1329 				if (m->queue != PQ_INACTIVE) {
1330 					break;
1331 				}
1332 
1333 				next = TAILQ_NEXT(m, pageq);
1334 				if (m->flags & PG_BUSY) {
1335 					m->flags |= PG_WANTED;
1336 					tsleep(m, PVM, "vpctw0", 0);
1337 					goto again1;
1338 				}
1339 				vm_page_test_dirty(m);
1340 				if (m->dirty) {
1341 					if (m->object->type == OBJT_VNODE) {
1342 						vm_object_page_clean(m->object, 0, 0, TRUE, TRUE);
1343 						goto again1;
1344 					} else if (m->object->type == OBJT_SWAP ||
1345 								m->object->type == OBJT_DEFAULT) {
1346 						vm_page_protect(m, VM_PROT_NONE);
1347 						vm_pageout_flush(&m, 1, 0);
1348 						goto again1;
1349 					}
1350 				}
1351 				if ((m->dirty == 0) &&
1352 					(m->busy == 0) &&
1353 					(m->hold_count == 0))
1354 					vm_page_cache(m);
1355 			}
1356 
1357 			for (m = TAILQ_FIRST(&vm_page_queue_active);
1358 				m != NULL;
1359 				m = next) {
1360 
1361 				if (m->queue != PQ_ACTIVE) {
1362 					break;
1363 				}
1364 
1365 				next = TAILQ_NEXT(m, pageq);
1366 				if (m->flags & PG_BUSY) {
1367 					m->flags |= PG_WANTED;
1368 					tsleep(m, PVM, "vpctw1", 0);
1369 					goto again1;
1370 				}
1371 				vm_page_test_dirty(m);
1372 				if (m->dirty) {
1373 					if (m->object->type == OBJT_VNODE) {
1374 						vm_object_page_clean(m->object, 0, 0, TRUE, TRUE);
1375 						goto again1;
1376 					} else if (m->object->type == OBJT_SWAP ||
1377 								m->object->type == OBJT_DEFAULT) {
1378 						vm_page_protect(m, VM_PROT_NONE);
1379 						vm_pageout_flush(&m, 1, 0);
1380 						goto again1;
1381 					}
1382 				}
1383 				if ((m->dirty == 0) &&
1384 					(m->busy == 0) &&
1385 					(m->hold_count == 0))
1386 					vm_page_cache(m);
1387 			}
1388 
1389 			splx(s);
1390 			continue;
1391 		}
1392 		start = i;
1393 
1394 		/*
1395 		 * Check successive pages for contiguous and free.
1396 		 */
1397 		for (i = start + 1; i < (start + size / PAGE_SIZE); i++) {
1398 			int pqtype;
1399 			pqtype = pga[i].queue - pga[i].pc;
1400 			if ((VM_PAGE_TO_PHYS(&pga[i]) !=
1401 			    (VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)) ||
1402 			    ((pqtype != PQ_ZERO) && (pqtype != PQ_FREE) && (pqtype != PQ_CACHE))) {
1403 				start++;
1404 				goto again;
1405 			}
1406 		}
1407 
1408 		for (i = start; i < (start + size / PAGE_SIZE); i++) {
1409 			int pqtype;
1410 			vm_page_t m = &pga[i];
1411 
1412 			pqtype = m->queue - m->pc;
1413 			if (pqtype == PQ_CACHE)
1414 				vm_page_free(m);
1415 
1416 			TAILQ_REMOVE(vm_page_queues[m->queue].pl, m, pageq);
1417 			--(*vm_page_queues[m->queue].lcnt);
1418 			cnt.v_free_count--;
1419 			m->valid = VM_PAGE_BITS_ALL;
1420 			m->flags = 0;
1421 			m->dirty = 0;
1422 			m->wire_count = 0;
1423 			m->busy = 0;
1424 			m->queue = PQ_NONE;
1425 			m->object = NULL;
1426 			vm_page_wire(m);
1427 		}
1428 
1429 		/*
1430 		 * We've found a contiguous chunk that meets are requirements.
1431 		 * Allocate kernel VM, unfree and assign the physical pages to it and
1432 		 * return kernel VM pointer.
1433 		 */
1434 		tmp_addr = addr = kmem_alloc_pageable(map, size);
1435 		if (addr == 0) {
1436 			/*
1437 			 * XXX We almost never run out of kernel virtual
1438 			 * space, so we don't make the allocated memory
1439 			 * above available.
1440 			 */
1441 			splx(s);
1442 			return (NULL);
1443 		}
1444 
1445 		for (i = start; i < (start + size / PAGE_SIZE); i++) {
1446 			vm_page_t m = &pga[i];
1447 			vm_page_insert(m, kernel_object,
1448 				OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS));
1449 			pmap_kenter(tmp_addr, VM_PAGE_TO_PHYS(m));
1450 			tmp_addr += PAGE_SIZE;
1451 		}
1452 
1453 		splx(s);
1454 		return ((void *)addr);
1455 	}
1456 	return NULL;
1457 }
1458 
1459 void *
1460 contigmalloc(size, type, flags, low, high, alignment, boundary)
1461 	unsigned long size;	/* should be size_t here and for malloc() */
1462 	int type;
1463 	int flags;
1464 	unsigned long low;
1465 	unsigned long high;
1466 	unsigned long alignment;
1467 	unsigned long boundary;
1468 {
1469 	return contigmalloc1(size, type, flags, low, high, alignment, boundary,
1470 			     kernel_map);
1471 }
1472 
1473 vm_offset_t
1474 vm_page_alloc_contig(size, low, high, alignment)
1475 	vm_offset_t size;
1476 	vm_offset_t low;
1477 	vm_offset_t high;
1478 	vm_offset_t alignment;
1479 {
1480 	return ((vm_offset_t)contigmalloc1(size, M_DEVBUF, M_NOWAIT, low, high,
1481 					  alignment, 0ul, kernel_map));
1482 }
1483 
1484 #include "opt_ddb.h"
1485 #ifdef DDB
1486 #include <sys/kernel.h>
1487 
1488 #include <ddb/ddb.h>
1489 
1490 DB_SHOW_COMMAND(page, vm_page_print_page_info)
1491 {
1492 	db_printf("cnt.v_free_count: %d\n", cnt.v_free_count);
1493 	db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count);
1494 	db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count);
1495 	db_printf("cnt.v_active_count: %d\n", cnt.v_active_count);
1496 	db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count);
1497 	db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved);
1498 	db_printf("cnt.v_free_min: %d\n", cnt.v_free_min);
1499 	db_printf("cnt.v_free_target: %d\n", cnt.v_free_target);
1500 	db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min);
1501 	db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target);
1502 }
1503 
1504 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
1505 {
1506 	int i;
1507 	db_printf("PQ_FREE:");
1508 	for(i=0;i<PQ_L2_SIZE;i++) {
1509 		db_printf(" %d", *vm_page_queues[PQ_FREE + i].lcnt);
1510 	}
1511 	db_printf("\n");
1512 
1513 	db_printf("PQ_CACHE:");
1514 	for(i=0;i<PQ_L2_SIZE;i++) {
1515 		db_printf(" %d", *vm_page_queues[PQ_CACHE + i].lcnt);
1516 	}
1517 	db_printf("\n");
1518 
1519 	db_printf("PQ_ZERO:");
1520 	for(i=0;i<PQ_L2_SIZE;i++) {
1521 		db_printf(" %d", *vm_page_queues[PQ_ZERO + i].lcnt);
1522 	}
1523 	db_printf("\n");
1524 
1525 	db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n",
1526 		*vm_page_queues[PQ_ACTIVE].lcnt,
1527 		*vm_page_queues[PQ_INACTIVE].lcnt);
1528 }
1529 #endif /* DDB */
1530