xref: /freebsd/sys/vm/vm_phys.c (revision 74ca7bf1d4c7173d5575ba168bc4b5f6d181ff5a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002-2006 Rice University
5  * Copyright (c) 2007 Alan L. Cox <alc@cs.rice.edu>
6  * All rights reserved.
7  *
8  * This software was developed for the FreeBSD Project by Alan L. Cox,
9  * Olivier Crameri, Peter Druschel, Sitaram Iyer, and Juan Navarro.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
24  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
30  * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  *	Physical memory system implementation
36  *
37  * Any external functions defined by this module are only to be used by the
38  * virtual memory system.
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include "opt_ddb.h"
45 #include "opt_vm.h"
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/lock.h>
50 #include <sys/kernel.h>
51 #include <sys/malloc.h>
52 #include <sys/mutex.h>
53 #include <sys/proc.h>
54 #include <sys/queue.h>
55 #include <sys/rwlock.h>
56 #include <sys/sbuf.h>
57 #include <sys/sysctl.h>
58 #include <sys/tree.h>
59 #include <sys/vmmeter.h>
60 #include <sys/seq.h>
61 
62 #include <ddb/ddb.h>
63 
64 #include <vm/vm.h>
65 #include <vm/vm_param.h>
66 #include <vm/vm_kern.h>
67 #include <vm/vm_object.h>
68 #include <vm/vm_page.h>
69 #include <vm/vm_phys.h>
70 #include <vm/vm_pagequeue.h>
71 
72 _Static_assert(sizeof(long) * NBBY >= VM_PHYSSEG_MAX,
73     "Too many physsegs.");
74 
75 #ifdef NUMA
76 struct mem_affinity __read_mostly *mem_affinity;
77 int __read_mostly *mem_locality;
78 #endif
79 
80 int __read_mostly vm_ndomains = 1;
81 
82 struct vm_phys_seg __read_mostly vm_phys_segs[VM_PHYSSEG_MAX];
83 int __read_mostly vm_phys_nsegs;
84 
85 struct vm_phys_fictitious_seg;
86 static int vm_phys_fictitious_cmp(struct vm_phys_fictitious_seg *,
87     struct vm_phys_fictitious_seg *);
88 
89 RB_HEAD(fict_tree, vm_phys_fictitious_seg) vm_phys_fictitious_tree =
90     RB_INITIALIZER(_vm_phys_fictitious_tree);
91 
92 struct vm_phys_fictitious_seg {
93 	RB_ENTRY(vm_phys_fictitious_seg) node;
94 	/* Memory region data */
95 	vm_paddr_t	start;
96 	vm_paddr_t	end;
97 	vm_page_t	first_page;
98 };
99 
100 RB_GENERATE_STATIC(fict_tree, vm_phys_fictitious_seg, node,
101     vm_phys_fictitious_cmp);
102 
103 static struct rwlock_padalign vm_phys_fictitious_reg_lock;
104 MALLOC_DEFINE(M_FICT_PAGES, "vm_fictitious", "Fictitious VM pages");
105 
106 static struct vm_freelist __aligned(CACHE_LINE_SIZE)
107     vm_phys_free_queues[MAXMEMDOM][VM_NFREELIST][VM_NFREEPOOL][VM_NFREEORDER];
108 
109 static int __read_mostly vm_nfreelists;
110 
111 /*
112  * Provides the mapping from VM_FREELIST_* to free list indices (flind).
113  */
114 static int __read_mostly vm_freelist_to_flind[VM_NFREELIST];
115 
116 CTASSERT(VM_FREELIST_DEFAULT == 0);
117 
118 #ifdef VM_FREELIST_ISADMA
119 #define	VM_ISADMA_BOUNDARY	16777216
120 #endif
121 #ifdef VM_FREELIST_DMA32
122 #define	VM_DMA32_BOUNDARY	((vm_paddr_t)1 << 32)
123 #endif
124 
125 /*
126  * Enforce the assumptions made by vm_phys_add_seg() and vm_phys_init() about
127  * the ordering of the free list boundaries.
128  */
129 #if defined(VM_ISADMA_BOUNDARY) && defined(VM_LOWMEM_BOUNDARY)
130 CTASSERT(VM_ISADMA_BOUNDARY < VM_LOWMEM_BOUNDARY);
131 #endif
132 #if defined(VM_LOWMEM_BOUNDARY) && defined(VM_DMA32_BOUNDARY)
133 CTASSERT(VM_LOWMEM_BOUNDARY < VM_DMA32_BOUNDARY);
134 #endif
135 
136 static int sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS);
137 SYSCTL_OID(_vm, OID_AUTO, phys_free, CTLTYPE_STRING | CTLFLAG_RD,
138     NULL, 0, sysctl_vm_phys_free, "A", "Phys Free Info");
139 
140 static int sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS);
141 SYSCTL_OID(_vm, OID_AUTO, phys_segs, CTLTYPE_STRING | CTLFLAG_RD,
142     NULL, 0, sysctl_vm_phys_segs, "A", "Phys Seg Info");
143 
144 #ifdef NUMA
145 static int sysctl_vm_phys_locality(SYSCTL_HANDLER_ARGS);
146 SYSCTL_OID(_vm, OID_AUTO, phys_locality, CTLTYPE_STRING | CTLFLAG_RD,
147     NULL, 0, sysctl_vm_phys_locality, "A", "Phys Locality Info");
148 #endif
149 
150 SYSCTL_INT(_vm, OID_AUTO, ndomains, CTLFLAG_RD,
151     &vm_ndomains, 0, "Number of physical memory domains available.");
152 
153 static vm_page_t vm_phys_alloc_seg_contig(struct vm_phys_seg *seg,
154     u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
155     vm_paddr_t boundary);
156 static void _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int domain);
157 static void vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end);
158 static void vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl,
159     int order);
160 
161 /*
162  * Red-black tree helpers for vm fictitious range management.
163  */
164 static inline int
165 vm_phys_fictitious_in_range(struct vm_phys_fictitious_seg *p,
166     struct vm_phys_fictitious_seg *range)
167 {
168 
169 	KASSERT(range->start != 0 && range->end != 0,
170 	    ("Invalid range passed on search for vm_fictitious page"));
171 	if (p->start >= range->end)
172 		return (1);
173 	if (p->start < range->start)
174 		return (-1);
175 
176 	return (0);
177 }
178 
179 static int
180 vm_phys_fictitious_cmp(struct vm_phys_fictitious_seg *p1,
181     struct vm_phys_fictitious_seg *p2)
182 {
183 
184 	/* Check if this is a search for a page */
185 	if (p1->end == 0)
186 		return (vm_phys_fictitious_in_range(p1, p2));
187 
188 	KASSERT(p2->end != 0,
189     ("Invalid range passed as second parameter to vm fictitious comparison"));
190 
191 	/* Searching to add a new range */
192 	if (p1->end <= p2->start)
193 		return (-1);
194 	if (p1->start >= p2->end)
195 		return (1);
196 
197 	panic("Trying to add overlapping vm fictitious ranges:\n"
198 	    "[%#jx:%#jx] and [%#jx:%#jx]", (uintmax_t)p1->start,
199 	    (uintmax_t)p1->end, (uintmax_t)p2->start, (uintmax_t)p2->end);
200 }
201 
202 int
203 vm_phys_domain_match(int prefer, vm_paddr_t low, vm_paddr_t high)
204 {
205 #ifdef NUMA
206 	domainset_t mask;
207 	int i;
208 
209 	if (vm_ndomains == 1 || mem_affinity == NULL)
210 		return (0);
211 
212 	DOMAINSET_ZERO(&mask);
213 	/*
214 	 * Check for any memory that overlaps low, high.
215 	 */
216 	for (i = 0; mem_affinity[i].end != 0; i++)
217 		if (mem_affinity[i].start <= high &&
218 		    mem_affinity[i].end >= low)
219 			DOMAINSET_SET(mem_affinity[i].domain, &mask);
220 	if (prefer != -1 && DOMAINSET_ISSET(prefer, &mask))
221 		return (prefer);
222 	if (DOMAINSET_EMPTY(&mask))
223 		panic("vm_phys_domain_match:  Impossible constraint");
224 	return (DOMAINSET_FFS(&mask) - 1);
225 #else
226 	return (0);
227 #endif
228 }
229 
230 /*
231  * Outputs the state of the physical memory allocator, specifically,
232  * the amount of physical memory in each free list.
233  */
234 static int
235 sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS)
236 {
237 	struct sbuf sbuf;
238 	struct vm_freelist *fl;
239 	int dom, error, flind, oind, pind;
240 
241 	error = sysctl_wire_old_buffer(req, 0);
242 	if (error != 0)
243 		return (error);
244 	sbuf_new_for_sysctl(&sbuf, NULL, 128 * vm_ndomains, req);
245 	for (dom = 0; dom < vm_ndomains; dom++) {
246 		sbuf_printf(&sbuf,"\nDOMAIN %d:\n", dom);
247 		for (flind = 0; flind < vm_nfreelists; flind++) {
248 			sbuf_printf(&sbuf, "\nFREE LIST %d:\n"
249 			    "\n  ORDER (SIZE)  |  NUMBER"
250 			    "\n              ", flind);
251 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
252 				sbuf_printf(&sbuf, "  |  POOL %d", pind);
253 			sbuf_printf(&sbuf, "\n--            ");
254 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
255 				sbuf_printf(&sbuf, "-- --      ");
256 			sbuf_printf(&sbuf, "--\n");
257 			for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
258 				sbuf_printf(&sbuf, "  %2d (%6dK)", oind,
259 				    1 << (PAGE_SHIFT - 10 + oind));
260 				for (pind = 0; pind < VM_NFREEPOOL; pind++) {
261 				fl = vm_phys_free_queues[dom][flind][pind];
262 					sbuf_printf(&sbuf, "  |  %6d",
263 					    fl[oind].lcnt);
264 				}
265 				sbuf_printf(&sbuf, "\n");
266 			}
267 		}
268 	}
269 	error = sbuf_finish(&sbuf);
270 	sbuf_delete(&sbuf);
271 	return (error);
272 }
273 
274 /*
275  * Outputs the set of physical memory segments.
276  */
277 static int
278 sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS)
279 {
280 	struct sbuf sbuf;
281 	struct vm_phys_seg *seg;
282 	int error, segind;
283 
284 	error = sysctl_wire_old_buffer(req, 0);
285 	if (error != 0)
286 		return (error);
287 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
288 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
289 		sbuf_printf(&sbuf, "\nSEGMENT %d:\n\n", segind);
290 		seg = &vm_phys_segs[segind];
291 		sbuf_printf(&sbuf, "start:     %#jx\n",
292 		    (uintmax_t)seg->start);
293 		sbuf_printf(&sbuf, "end:       %#jx\n",
294 		    (uintmax_t)seg->end);
295 		sbuf_printf(&sbuf, "domain:    %d\n", seg->domain);
296 		sbuf_printf(&sbuf, "free list: %p\n", seg->free_queues);
297 	}
298 	error = sbuf_finish(&sbuf);
299 	sbuf_delete(&sbuf);
300 	return (error);
301 }
302 
303 /*
304  * Return affinity, or -1 if there's no affinity information.
305  */
306 int
307 vm_phys_mem_affinity(int f, int t)
308 {
309 
310 #ifdef NUMA
311 	if (mem_locality == NULL)
312 		return (-1);
313 	if (f >= vm_ndomains || t >= vm_ndomains)
314 		return (-1);
315 	return (mem_locality[f * vm_ndomains + t]);
316 #else
317 	return (-1);
318 #endif
319 }
320 
321 #ifdef NUMA
322 /*
323  * Outputs the VM locality table.
324  */
325 static int
326 sysctl_vm_phys_locality(SYSCTL_HANDLER_ARGS)
327 {
328 	struct sbuf sbuf;
329 	int error, i, j;
330 
331 	error = sysctl_wire_old_buffer(req, 0);
332 	if (error != 0)
333 		return (error);
334 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
335 
336 	sbuf_printf(&sbuf, "\n");
337 
338 	for (i = 0; i < vm_ndomains; i++) {
339 		sbuf_printf(&sbuf, "%d: ", i);
340 		for (j = 0; j < vm_ndomains; j++) {
341 			sbuf_printf(&sbuf, "%d ", vm_phys_mem_affinity(i, j));
342 		}
343 		sbuf_printf(&sbuf, "\n");
344 	}
345 	error = sbuf_finish(&sbuf);
346 	sbuf_delete(&sbuf);
347 	return (error);
348 }
349 #endif
350 
351 static void
352 vm_freelist_add(struct vm_freelist *fl, vm_page_t m, int order, int tail)
353 {
354 
355 	m->order = order;
356 	if (tail)
357 		TAILQ_INSERT_TAIL(&fl[order].pl, m, plinks.q);
358 	else
359 		TAILQ_INSERT_HEAD(&fl[order].pl, m, plinks.q);
360 	fl[order].lcnt++;
361 }
362 
363 static void
364 vm_freelist_rem(struct vm_freelist *fl, vm_page_t m, int order)
365 {
366 
367 	TAILQ_REMOVE(&fl[order].pl, m, plinks.q);
368 	fl[order].lcnt--;
369 	m->order = VM_NFREEORDER;
370 }
371 
372 /*
373  * Create a physical memory segment.
374  */
375 static void
376 _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int domain)
377 {
378 	struct vm_phys_seg *seg;
379 
380 	KASSERT(vm_phys_nsegs < VM_PHYSSEG_MAX,
381 	    ("vm_phys_create_seg: increase VM_PHYSSEG_MAX"));
382 	KASSERT(domain >= 0 && domain < vm_ndomains,
383 	    ("vm_phys_create_seg: invalid domain provided"));
384 	seg = &vm_phys_segs[vm_phys_nsegs++];
385 	while (seg > vm_phys_segs && (seg - 1)->start >= end) {
386 		*seg = *(seg - 1);
387 		seg--;
388 	}
389 	seg->start = start;
390 	seg->end = end;
391 	seg->domain = domain;
392 }
393 
394 static void
395 vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end)
396 {
397 #ifdef NUMA
398 	int i;
399 
400 	if (mem_affinity == NULL) {
401 		_vm_phys_create_seg(start, end, 0);
402 		return;
403 	}
404 
405 	for (i = 0;; i++) {
406 		if (mem_affinity[i].end == 0)
407 			panic("Reached end of affinity info");
408 		if (mem_affinity[i].end <= start)
409 			continue;
410 		if (mem_affinity[i].start > start)
411 			panic("No affinity info for start %jx",
412 			    (uintmax_t)start);
413 		if (mem_affinity[i].end >= end) {
414 			_vm_phys_create_seg(start, end,
415 			    mem_affinity[i].domain);
416 			break;
417 		}
418 		_vm_phys_create_seg(start, mem_affinity[i].end,
419 		    mem_affinity[i].domain);
420 		start = mem_affinity[i].end;
421 	}
422 #else
423 	_vm_phys_create_seg(start, end, 0);
424 #endif
425 }
426 
427 /*
428  * Add a physical memory segment.
429  */
430 void
431 vm_phys_add_seg(vm_paddr_t start, vm_paddr_t end)
432 {
433 	vm_paddr_t paddr;
434 
435 	KASSERT((start & PAGE_MASK) == 0,
436 	    ("vm_phys_define_seg: start is not page aligned"));
437 	KASSERT((end & PAGE_MASK) == 0,
438 	    ("vm_phys_define_seg: end is not page aligned"));
439 
440 	/*
441 	 * Split the physical memory segment if it spans two or more free
442 	 * list boundaries.
443 	 */
444 	paddr = start;
445 #ifdef	VM_FREELIST_ISADMA
446 	if (paddr < VM_ISADMA_BOUNDARY && end > VM_ISADMA_BOUNDARY) {
447 		vm_phys_create_seg(paddr, VM_ISADMA_BOUNDARY);
448 		paddr = VM_ISADMA_BOUNDARY;
449 	}
450 #endif
451 #ifdef	VM_FREELIST_LOWMEM
452 	if (paddr < VM_LOWMEM_BOUNDARY && end > VM_LOWMEM_BOUNDARY) {
453 		vm_phys_create_seg(paddr, VM_LOWMEM_BOUNDARY);
454 		paddr = VM_LOWMEM_BOUNDARY;
455 	}
456 #endif
457 #ifdef	VM_FREELIST_DMA32
458 	if (paddr < VM_DMA32_BOUNDARY && end > VM_DMA32_BOUNDARY) {
459 		vm_phys_create_seg(paddr, VM_DMA32_BOUNDARY);
460 		paddr = VM_DMA32_BOUNDARY;
461 	}
462 #endif
463 	vm_phys_create_seg(paddr, end);
464 }
465 
466 /*
467  * Initialize the physical memory allocator.
468  *
469  * Requires that vm_page_array is initialized!
470  */
471 void
472 vm_phys_init(void)
473 {
474 	struct vm_freelist *fl;
475 	struct vm_phys_seg *seg;
476 	u_long npages;
477 	int dom, flind, freelist, oind, pind, segind;
478 
479 	/*
480 	 * Compute the number of free lists, and generate the mapping from the
481 	 * manifest constants VM_FREELIST_* to the free list indices.
482 	 *
483 	 * Initially, the entries of vm_freelist_to_flind[] are set to either
484 	 * 0 or 1 to indicate which free lists should be created.
485 	 */
486 	npages = 0;
487 	for (segind = vm_phys_nsegs - 1; segind >= 0; segind--) {
488 		seg = &vm_phys_segs[segind];
489 #ifdef	VM_FREELIST_ISADMA
490 		if (seg->end <= VM_ISADMA_BOUNDARY)
491 			vm_freelist_to_flind[VM_FREELIST_ISADMA] = 1;
492 		else
493 #endif
494 #ifdef	VM_FREELIST_LOWMEM
495 		if (seg->end <= VM_LOWMEM_BOUNDARY)
496 			vm_freelist_to_flind[VM_FREELIST_LOWMEM] = 1;
497 		else
498 #endif
499 #ifdef	VM_FREELIST_DMA32
500 		if (
501 #ifdef	VM_DMA32_NPAGES_THRESHOLD
502 		    /*
503 		     * Create the DMA32 free list only if the amount of
504 		     * physical memory above physical address 4G exceeds the
505 		     * given threshold.
506 		     */
507 		    npages > VM_DMA32_NPAGES_THRESHOLD &&
508 #endif
509 		    seg->end <= VM_DMA32_BOUNDARY)
510 			vm_freelist_to_flind[VM_FREELIST_DMA32] = 1;
511 		else
512 #endif
513 		{
514 			npages += atop(seg->end - seg->start);
515 			vm_freelist_to_flind[VM_FREELIST_DEFAULT] = 1;
516 		}
517 	}
518 	/* Change each entry into a running total of the free lists. */
519 	for (freelist = 1; freelist < VM_NFREELIST; freelist++) {
520 		vm_freelist_to_flind[freelist] +=
521 		    vm_freelist_to_flind[freelist - 1];
522 	}
523 	vm_nfreelists = vm_freelist_to_flind[VM_NFREELIST - 1];
524 	KASSERT(vm_nfreelists > 0, ("vm_phys_init: no free lists"));
525 	/* Change each entry into a free list index. */
526 	for (freelist = 0; freelist < VM_NFREELIST; freelist++)
527 		vm_freelist_to_flind[freelist]--;
528 
529 	/*
530 	 * Initialize the first_page and free_queues fields of each physical
531 	 * memory segment.
532 	 */
533 #ifdef VM_PHYSSEG_SPARSE
534 	npages = 0;
535 #endif
536 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
537 		seg = &vm_phys_segs[segind];
538 #ifdef VM_PHYSSEG_SPARSE
539 		seg->first_page = &vm_page_array[npages];
540 		npages += atop(seg->end - seg->start);
541 #else
542 		seg->first_page = PHYS_TO_VM_PAGE(seg->start);
543 #endif
544 #ifdef	VM_FREELIST_ISADMA
545 		if (seg->end <= VM_ISADMA_BOUNDARY) {
546 			flind = vm_freelist_to_flind[VM_FREELIST_ISADMA];
547 			KASSERT(flind >= 0,
548 			    ("vm_phys_init: ISADMA flind < 0"));
549 		} else
550 #endif
551 #ifdef	VM_FREELIST_LOWMEM
552 		if (seg->end <= VM_LOWMEM_BOUNDARY) {
553 			flind = vm_freelist_to_flind[VM_FREELIST_LOWMEM];
554 			KASSERT(flind >= 0,
555 			    ("vm_phys_init: LOWMEM flind < 0"));
556 		} else
557 #endif
558 #ifdef	VM_FREELIST_DMA32
559 		if (seg->end <= VM_DMA32_BOUNDARY) {
560 			flind = vm_freelist_to_flind[VM_FREELIST_DMA32];
561 			KASSERT(flind >= 0,
562 			    ("vm_phys_init: DMA32 flind < 0"));
563 		} else
564 #endif
565 		{
566 			flind = vm_freelist_to_flind[VM_FREELIST_DEFAULT];
567 			KASSERT(flind >= 0,
568 			    ("vm_phys_init: DEFAULT flind < 0"));
569 		}
570 		seg->free_queues = &vm_phys_free_queues[seg->domain][flind];
571 	}
572 
573 	/*
574 	 * Initialize the free queues.
575 	 */
576 	for (dom = 0; dom < vm_ndomains; dom++) {
577 		for (flind = 0; flind < vm_nfreelists; flind++) {
578 			for (pind = 0; pind < VM_NFREEPOOL; pind++) {
579 				fl = vm_phys_free_queues[dom][flind][pind];
580 				for (oind = 0; oind < VM_NFREEORDER; oind++)
581 					TAILQ_INIT(&fl[oind].pl);
582 			}
583 		}
584 	}
585 
586 	rw_init(&vm_phys_fictitious_reg_lock, "vmfctr");
587 }
588 
589 /*
590  * Split a contiguous, power of two-sized set of physical pages.
591  */
592 static __inline void
593 vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl, int order)
594 {
595 	vm_page_t m_buddy;
596 
597 	while (oind > order) {
598 		oind--;
599 		m_buddy = &m[1 << oind];
600 		KASSERT(m_buddy->order == VM_NFREEORDER,
601 		    ("vm_phys_split_pages: page %p has unexpected order %d",
602 		    m_buddy, m_buddy->order));
603 		vm_freelist_add(fl, m_buddy, oind, 0);
604         }
605 }
606 
607 /*
608  * Allocate a contiguous, power of two-sized set of physical pages
609  * from the free lists.
610  *
611  * The free page queues must be locked.
612  */
613 vm_page_t
614 vm_phys_alloc_pages(int domain, int pool, int order)
615 {
616 	vm_page_t m;
617 	int freelist;
618 
619 	for (freelist = 0; freelist < VM_NFREELIST; freelist++) {
620 		m = vm_phys_alloc_freelist_pages(domain, freelist, pool, order);
621 		if (m != NULL)
622 			return (m);
623 	}
624 	return (NULL);
625 }
626 
627 int
628 vm_phys_alloc_npages(int domain, int pool, vm_page_t *mp, int cnt)
629 {
630 	vm_page_t m;
631 	int order, freelist;
632 
633 	for (freelist = 0; freelist < VM_NFREELIST; freelist++) {
634 		for (order = fls(cnt) -1; order >= 0; order--) {
635 			m = vm_phys_alloc_freelist_pages(domain, freelist,
636 			    pool, order);
637 			if (m != NULL) {
638 				*mp = m;
639 				return (1 << order);
640 			}
641 		}
642 	}
643 	*mp = NULL;
644 	return (0);
645 }
646 
647 /*
648  * Allocate a contiguous, power of two-sized set of physical pages from the
649  * specified free list.  The free list must be specified using one of the
650  * manifest constants VM_FREELIST_*.
651  *
652  * The free page queues must be locked.
653  */
654 vm_page_t
655 vm_phys_alloc_freelist_pages(int domain, int freelist, int pool, int order)
656 {
657 	struct vm_freelist *alt, *fl;
658 	vm_page_t m;
659 	int oind, pind, flind;
660 
661 	KASSERT(domain >= 0 && domain < vm_ndomains,
662 	    ("vm_phys_alloc_freelist_pages: domain %d is out of range",
663 	    domain));
664 	KASSERT(freelist < VM_NFREELIST,
665 	    ("vm_phys_alloc_freelist_pages: freelist %d is out of range",
666 	    freelist));
667 	KASSERT(pool < VM_NFREEPOOL,
668 	    ("vm_phys_alloc_freelist_pages: pool %d is out of range", pool));
669 	KASSERT(order < VM_NFREEORDER,
670 	    ("vm_phys_alloc_freelist_pages: order %d is out of range", order));
671 
672 	flind = vm_freelist_to_flind[freelist];
673 	/* Check if freelist is present */
674 	if (flind < 0)
675 		return (NULL);
676 
677 	vm_domain_free_assert_locked(VM_DOMAIN(domain));
678 	fl = &vm_phys_free_queues[domain][flind][pool][0];
679 	for (oind = order; oind < VM_NFREEORDER; oind++) {
680 		m = TAILQ_FIRST(&fl[oind].pl);
681 		if (m != NULL) {
682 			vm_freelist_rem(fl, m, oind);
683 			vm_phys_split_pages(m, oind, fl, order);
684 			return (m);
685 		}
686 	}
687 
688 	/*
689 	 * The given pool was empty.  Find the largest
690 	 * contiguous, power-of-two-sized set of pages in any
691 	 * pool.  Transfer these pages to the given pool, and
692 	 * use them to satisfy the allocation.
693 	 */
694 	for (oind = VM_NFREEORDER - 1; oind >= order; oind--) {
695 		for (pind = 0; pind < VM_NFREEPOOL; pind++) {
696 			alt = &vm_phys_free_queues[domain][flind][pind][0];
697 			m = TAILQ_FIRST(&alt[oind].pl);
698 			if (m != NULL) {
699 				vm_freelist_rem(alt, m, oind);
700 				vm_phys_set_pool(pool, m, oind);
701 				vm_phys_split_pages(m, oind, fl, order);
702 				return (m);
703 			}
704 		}
705 	}
706 	return (NULL);
707 }
708 
709 /*
710  * Find the vm_page corresponding to the given physical address.
711  */
712 vm_page_t
713 vm_phys_paddr_to_vm_page(vm_paddr_t pa)
714 {
715 	struct vm_phys_seg *seg;
716 	int segind;
717 
718 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
719 		seg = &vm_phys_segs[segind];
720 		if (pa >= seg->start && pa < seg->end)
721 			return (&seg->first_page[atop(pa - seg->start)]);
722 	}
723 	return (NULL);
724 }
725 
726 vm_page_t
727 vm_phys_fictitious_to_vm_page(vm_paddr_t pa)
728 {
729 	struct vm_phys_fictitious_seg tmp, *seg;
730 	vm_page_t m;
731 
732 	m = NULL;
733 	tmp.start = pa;
734 	tmp.end = 0;
735 
736 	rw_rlock(&vm_phys_fictitious_reg_lock);
737 	seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
738 	rw_runlock(&vm_phys_fictitious_reg_lock);
739 	if (seg == NULL)
740 		return (NULL);
741 
742 	m = &seg->first_page[atop(pa - seg->start)];
743 	KASSERT((m->flags & PG_FICTITIOUS) != 0, ("%p not fictitious", m));
744 
745 	return (m);
746 }
747 
748 static inline void
749 vm_phys_fictitious_init_range(vm_page_t range, vm_paddr_t start,
750     long page_count, vm_memattr_t memattr)
751 {
752 	long i;
753 
754 	bzero(range, page_count * sizeof(*range));
755 	for (i = 0; i < page_count; i++) {
756 		vm_page_initfake(&range[i], start + PAGE_SIZE * i, memattr);
757 		range[i].oflags &= ~VPO_UNMANAGED;
758 		range[i].busy_lock = VPB_UNBUSIED;
759 	}
760 }
761 
762 int
763 vm_phys_fictitious_reg_range(vm_paddr_t start, vm_paddr_t end,
764     vm_memattr_t memattr)
765 {
766 	struct vm_phys_fictitious_seg *seg;
767 	vm_page_t fp;
768 	long page_count;
769 #ifdef VM_PHYSSEG_DENSE
770 	long pi, pe;
771 	long dpage_count;
772 #endif
773 
774 	KASSERT(start < end,
775 	    ("Start of segment isn't less than end (start: %jx end: %jx)",
776 	    (uintmax_t)start, (uintmax_t)end));
777 
778 	page_count = (end - start) / PAGE_SIZE;
779 
780 #ifdef VM_PHYSSEG_DENSE
781 	pi = atop(start);
782 	pe = atop(end);
783 	if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
784 		fp = &vm_page_array[pi - first_page];
785 		if ((pe - first_page) > vm_page_array_size) {
786 			/*
787 			 * We have a segment that starts inside
788 			 * of vm_page_array, but ends outside of it.
789 			 *
790 			 * Use vm_page_array pages for those that are
791 			 * inside of the vm_page_array range, and
792 			 * allocate the remaining ones.
793 			 */
794 			dpage_count = vm_page_array_size - (pi - first_page);
795 			vm_phys_fictitious_init_range(fp, start, dpage_count,
796 			    memattr);
797 			page_count -= dpage_count;
798 			start += ptoa(dpage_count);
799 			goto alloc;
800 		}
801 		/*
802 		 * We can allocate the full range from vm_page_array,
803 		 * so there's no need to register the range in the tree.
804 		 */
805 		vm_phys_fictitious_init_range(fp, start, page_count, memattr);
806 		return (0);
807 	} else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
808 		/*
809 		 * We have a segment that ends inside of vm_page_array,
810 		 * but starts outside of it.
811 		 */
812 		fp = &vm_page_array[0];
813 		dpage_count = pe - first_page;
814 		vm_phys_fictitious_init_range(fp, ptoa(first_page), dpage_count,
815 		    memattr);
816 		end -= ptoa(dpage_count);
817 		page_count -= dpage_count;
818 		goto alloc;
819 	} else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
820 		/*
821 		 * Trying to register a fictitious range that expands before
822 		 * and after vm_page_array.
823 		 */
824 		return (EINVAL);
825 	} else {
826 alloc:
827 #endif
828 		fp = malloc(page_count * sizeof(struct vm_page), M_FICT_PAGES,
829 		    M_WAITOK);
830 #ifdef VM_PHYSSEG_DENSE
831 	}
832 #endif
833 	vm_phys_fictitious_init_range(fp, start, page_count, memattr);
834 
835 	seg = malloc(sizeof(*seg), M_FICT_PAGES, M_WAITOK | M_ZERO);
836 	seg->start = start;
837 	seg->end = end;
838 	seg->first_page = fp;
839 
840 	rw_wlock(&vm_phys_fictitious_reg_lock);
841 	RB_INSERT(fict_tree, &vm_phys_fictitious_tree, seg);
842 	rw_wunlock(&vm_phys_fictitious_reg_lock);
843 
844 	return (0);
845 }
846 
847 void
848 vm_phys_fictitious_unreg_range(vm_paddr_t start, vm_paddr_t end)
849 {
850 	struct vm_phys_fictitious_seg *seg, tmp;
851 #ifdef VM_PHYSSEG_DENSE
852 	long pi, pe;
853 #endif
854 
855 	KASSERT(start < end,
856 	    ("Start of segment isn't less than end (start: %jx end: %jx)",
857 	    (uintmax_t)start, (uintmax_t)end));
858 
859 #ifdef VM_PHYSSEG_DENSE
860 	pi = atop(start);
861 	pe = atop(end);
862 	if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
863 		if ((pe - first_page) <= vm_page_array_size) {
864 			/*
865 			 * This segment was allocated using vm_page_array
866 			 * only, there's nothing to do since those pages
867 			 * were never added to the tree.
868 			 */
869 			return;
870 		}
871 		/*
872 		 * We have a segment that starts inside
873 		 * of vm_page_array, but ends outside of it.
874 		 *
875 		 * Calculate how many pages were added to the
876 		 * tree and free them.
877 		 */
878 		start = ptoa(first_page + vm_page_array_size);
879 	} else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
880 		/*
881 		 * We have a segment that ends inside of vm_page_array,
882 		 * but starts outside of it.
883 		 */
884 		end = ptoa(first_page);
885 	} else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
886 		/* Since it's not possible to register such a range, panic. */
887 		panic(
888 		    "Unregistering not registered fictitious range [%#jx:%#jx]",
889 		    (uintmax_t)start, (uintmax_t)end);
890 	}
891 #endif
892 	tmp.start = start;
893 	tmp.end = 0;
894 
895 	rw_wlock(&vm_phys_fictitious_reg_lock);
896 	seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
897 	if (seg->start != start || seg->end != end) {
898 		rw_wunlock(&vm_phys_fictitious_reg_lock);
899 		panic(
900 		    "Unregistering not registered fictitious range [%#jx:%#jx]",
901 		    (uintmax_t)start, (uintmax_t)end);
902 	}
903 	RB_REMOVE(fict_tree, &vm_phys_fictitious_tree, seg);
904 	rw_wunlock(&vm_phys_fictitious_reg_lock);
905 	free(seg->first_page, M_FICT_PAGES);
906 	free(seg, M_FICT_PAGES);
907 }
908 
909 /*
910  * Free a contiguous, power of two-sized set of physical pages.
911  *
912  * The free page queues must be locked.
913  */
914 void
915 vm_phys_free_pages(vm_page_t m, int order)
916 {
917 	struct vm_freelist *fl;
918 	struct vm_phys_seg *seg;
919 	vm_paddr_t pa;
920 	vm_page_t m_buddy;
921 
922 	KASSERT(m->order == VM_NFREEORDER,
923 	    ("vm_phys_free_pages: page %p has unexpected order %d",
924 	    m, m->order));
925 	KASSERT(m->pool < VM_NFREEPOOL,
926 	    ("vm_phys_free_pages: page %p has unexpected pool %d",
927 	    m, m->pool));
928 	KASSERT(order < VM_NFREEORDER,
929 	    ("vm_phys_free_pages: order %d is out of range", order));
930 	seg = &vm_phys_segs[m->segind];
931 	vm_domain_free_assert_locked(VM_DOMAIN(seg->domain));
932 	if (order < VM_NFREEORDER - 1) {
933 		pa = VM_PAGE_TO_PHYS(m);
934 		do {
935 			pa ^= ((vm_paddr_t)1 << (PAGE_SHIFT + order));
936 			if (pa < seg->start || pa >= seg->end)
937 				break;
938 			m_buddy = &seg->first_page[atop(pa - seg->start)];
939 			if (m_buddy->order != order)
940 				break;
941 			fl = (*seg->free_queues)[m_buddy->pool];
942 			vm_freelist_rem(fl, m_buddy, order);
943 			if (m_buddy->pool != m->pool)
944 				vm_phys_set_pool(m->pool, m_buddy, order);
945 			order++;
946 			pa &= ~(((vm_paddr_t)1 << (PAGE_SHIFT + order)) - 1);
947 			m = &seg->first_page[atop(pa - seg->start)];
948 		} while (order < VM_NFREEORDER - 1);
949 	}
950 	fl = (*seg->free_queues)[m->pool];
951 	vm_freelist_add(fl, m, order, 1);
952 }
953 
954 /*
955  * Free a contiguous, arbitrarily sized set of physical pages.
956  *
957  * The free page queues must be locked.
958  */
959 void
960 vm_phys_free_contig(vm_page_t m, u_long npages)
961 {
962 	u_int n;
963 	int order;
964 
965 	/*
966 	 * Avoid unnecessary coalescing by freeing the pages in the largest
967 	 * possible power-of-two-sized subsets.
968 	 */
969 	vm_domain_free_assert_locked(vm_pagequeue_domain(m));
970 	for (;; npages -= n) {
971 		/*
972 		 * Unsigned "min" is used here so that "order" is assigned
973 		 * "VM_NFREEORDER - 1" when "m"'s physical address is zero
974 		 * or the low-order bits of its physical address are zero
975 		 * because the size of a physical address exceeds the size of
976 		 * a long.
977 		 */
978 		order = min(ffsl(VM_PAGE_TO_PHYS(m) >> PAGE_SHIFT) - 1,
979 		    VM_NFREEORDER - 1);
980 		n = 1 << order;
981 		if (npages < n)
982 			break;
983 		vm_phys_free_pages(m, order);
984 		m += n;
985 	}
986 	/* The residual "npages" is less than "1 << (VM_NFREEORDER - 1)". */
987 	for (; npages > 0; npages -= n) {
988 		order = flsl(npages) - 1;
989 		n = 1 << order;
990 		vm_phys_free_pages(m, order);
991 		m += n;
992 	}
993 }
994 
995 /*
996  * Scan physical memory between the specified addresses "low" and "high" for a
997  * run of contiguous physical pages that satisfy the specified conditions, and
998  * return the lowest page in the run.  The specified "alignment" determines
999  * the alignment of the lowest physical page in the run.  If the specified
1000  * "boundary" is non-zero, then the run of physical pages cannot span a
1001  * physical address that is a multiple of "boundary".
1002  *
1003  * "npages" must be greater than zero.  Both "alignment" and "boundary" must
1004  * be a power of two.
1005  */
1006 vm_page_t
1007 vm_phys_scan_contig(int domain, u_long npages, vm_paddr_t low, vm_paddr_t high,
1008     u_long alignment, vm_paddr_t boundary, int options)
1009 {
1010 	vm_paddr_t pa_end;
1011 	vm_page_t m_end, m_run, m_start;
1012 	struct vm_phys_seg *seg;
1013 	int segind;
1014 
1015 	KASSERT(npages > 0, ("npages is 0"));
1016 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1017 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1018 	if (low >= high)
1019 		return (NULL);
1020 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
1021 		seg = &vm_phys_segs[segind];
1022 		if (seg->domain != domain)
1023 			continue;
1024 		if (seg->start >= high)
1025 			break;
1026 		if (low >= seg->end)
1027 			continue;
1028 		if (low <= seg->start)
1029 			m_start = seg->first_page;
1030 		else
1031 			m_start = &seg->first_page[atop(low - seg->start)];
1032 		if (high < seg->end)
1033 			pa_end = high;
1034 		else
1035 			pa_end = seg->end;
1036 		if (pa_end - VM_PAGE_TO_PHYS(m_start) < ptoa(npages))
1037 			continue;
1038 		m_end = &seg->first_page[atop(pa_end - seg->start)];
1039 		m_run = vm_page_scan_contig(npages, m_start, m_end,
1040 		    alignment, boundary, options);
1041 		if (m_run != NULL)
1042 			return (m_run);
1043 	}
1044 	return (NULL);
1045 }
1046 
1047 /*
1048  * Set the pool for a contiguous, power of two-sized set of physical pages.
1049  */
1050 void
1051 vm_phys_set_pool(int pool, vm_page_t m, int order)
1052 {
1053 	vm_page_t m_tmp;
1054 
1055 	for (m_tmp = m; m_tmp < &m[1 << order]; m_tmp++)
1056 		m_tmp->pool = pool;
1057 }
1058 
1059 /*
1060  * Search for the given physical page "m" in the free lists.  If the search
1061  * succeeds, remove "m" from the free lists and return TRUE.  Otherwise, return
1062  * FALSE, indicating that "m" is not in the free lists.
1063  *
1064  * The free page queues must be locked.
1065  */
1066 boolean_t
1067 vm_phys_unfree_page(vm_page_t m)
1068 {
1069 	struct vm_freelist *fl;
1070 	struct vm_phys_seg *seg;
1071 	vm_paddr_t pa, pa_half;
1072 	vm_page_t m_set, m_tmp;
1073 	int order;
1074 
1075 	/*
1076 	 * First, find the contiguous, power of two-sized set of free
1077 	 * physical pages containing the given physical page "m" and
1078 	 * assign it to "m_set".
1079 	 */
1080 	seg = &vm_phys_segs[m->segind];
1081 	vm_domain_free_assert_locked(VM_DOMAIN(seg->domain));
1082 	for (m_set = m, order = 0; m_set->order == VM_NFREEORDER &&
1083 	    order < VM_NFREEORDER - 1; ) {
1084 		order++;
1085 		pa = m->phys_addr & (~(vm_paddr_t)0 << (PAGE_SHIFT + order));
1086 		if (pa >= seg->start)
1087 			m_set = &seg->first_page[atop(pa - seg->start)];
1088 		else
1089 			return (FALSE);
1090 	}
1091 	if (m_set->order < order)
1092 		return (FALSE);
1093 	if (m_set->order == VM_NFREEORDER)
1094 		return (FALSE);
1095 	KASSERT(m_set->order < VM_NFREEORDER,
1096 	    ("vm_phys_unfree_page: page %p has unexpected order %d",
1097 	    m_set, m_set->order));
1098 
1099 	/*
1100 	 * Next, remove "m_set" from the free lists.  Finally, extract
1101 	 * "m" from "m_set" using an iterative algorithm: While "m_set"
1102 	 * is larger than a page, shrink "m_set" by returning the half
1103 	 * of "m_set" that does not contain "m" to the free lists.
1104 	 */
1105 	fl = (*seg->free_queues)[m_set->pool];
1106 	order = m_set->order;
1107 	vm_freelist_rem(fl, m_set, order);
1108 	while (order > 0) {
1109 		order--;
1110 		pa_half = m_set->phys_addr ^ (1 << (PAGE_SHIFT + order));
1111 		if (m->phys_addr < pa_half)
1112 			m_tmp = &seg->first_page[atop(pa_half - seg->start)];
1113 		else {
1114 			m_tmp = m_set;
1115 			m_set = &seg->first_page[atop(pa_half - seg->start)];
1116 		}
1117 		vm_freelist_add(fl, m_tmp, order, 0);
1118 	}
1119 	KASSERT(m_set == m, ("vm_phys_unfree_page: fatal inconsistency"));
1120 	return (TRUE);
1121 }
1122 
1123 /*
1124  * Allocate a contiguous set of physical pages of the given size
1125  * "npages" from the free lists.  All of the physical pages must be at
1126  * or above the given physical address "low" and below the given
1127  * physical address "high".  The given value "alignment" determines the
1128  * alignment of the first physical page in the set.  If the given value
1129  * "boundary" is non-zero, then the set of physical pages cannot cross
1130  * any physical address boundary that is a multiple of that value.  Both
1131  * "alignment" and "boundary" must be a power of two.
1132  */
1133 vm_page_t
1134 vm_phys_alloc_contig(int domain, u_long npages, vm_paddr_t low, vm_paddr_t high,
1135     u_long alignment, vm_paddr_t boundary)
1136 {
1137 	vm_paddr_t pa_end, pa_start;
1138 	vm_page_t m_run;
1139 	struct vm_phys_seg *seg;
1140 	int segind;
1141 
1142 	KASSERT(npages > 0, ("npages is 0"));
1143 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1144 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1145 	vm_domain_free_assert_locked(VM_DOMAIN(domain));
1146 	if (low >= high)
1147 		return (NULL);
1148 	m_run = NULL;
1149 	for (segind = vm_phys_nsegs - 1; segind >= 0; segind--) {
1150 		seg = &vm_phys_segs[segind];
1151 		if (seg->start >= high || seg->domain != domain)
1152 			continue;
1153 		if (low >= seg->end)
1154 			break;
1155 		if (low <= seg->start)
1156 			pa_start = seg->start;
1157 		else
1158 			pa_start = low;
1159 		if (high < seg->end)
1160 			pa_end = high;
1161 		else
1162 			pa_end = seg->end;
1163 		if (pa_end - pa_start < ptoa(npages))
1164 			continue;
1165 		m_run = vm_phys_alloc_seg_contig(seg, npages, low, high,
1166 		    alignment, boundary);
1167 		if (m_run != NULL)
1168 			break;
1169 	}
1170 	return (m_run);
1171 }
1172 
1173 /*
1174  * Allocate a run of contiguous physical pages from the free list for the
1175  * specified segment.
1176  */
1177 static vm_page_t
1178 vm_phys_alloc_seg_contig(struct vm_phys_seg *seg, u_long npages,
1179     vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
1180 {
1181 	struct vm_freelist *fl;
1182 	vm_paddr_t pa, pa_end, size;
1183 	vm_page_t m, m_ret;
1184 	u_long npages_end;
1185 	int oind, order, pind;
1186 
1187 	KASSERT(npages > 0, ("npages is 0"));
1188 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1189 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1190 	vm_domain_free_assert_locked(VM_DOMAIN(seg->domain));
1191 	/* Compute the queue that is the best fit for npages. */
1192 	for (order = 0; (1 << order) < npages; order++);
1193 	/* Search for a run satisfying the specified conditions. */
1194 	size = npages << PAGE_SHIFT;
1195 	for (oind = min(order, VM_NFREEORDER - 1); oind < VM_NFREEORDER;
1196 	    oind++) {
1197 		for (pind = 0; pind < VM_NFREEPOOL; pind++) {
1198 			fl = (*seg->free_queues)[pind];
1199 			TAILQ_FOREACH(m_ret, &fl[oind].pl, plinks.q) {
1200 				/*
1201 				 * Is the size of this allocation request
1202 				 * larger than the largest block size?
1203 				 */
1204 				if (order >= VM_NFREEORDER) {
1205 					/*
1206 					 * Determine if a sufficient number of
1207 					 * subsequent blocks to satisfy the
1208 					 * allocation request are free.
1209 					 */
1210 					pa = VM_PAGE_TO_PHYS(m_ret);
1211 					pa_end = pa + size;
1212 					if (pa_end < pa)
1213 						continue;
1214 					for (;;) {
1215 						pa += 1 << (PAGE_SHIFT +
1216 						    VM_NFREEORDER - 1);
1217 						if (pa >= pa_end ||
1218 						    pa < seg->start ||
1219 						    pa >= seg->end)
1220 							break;
1221 						m = &seg->first_page[atop(pa -
1222 						    seg->start)];
1223 						if (m->order != VM_NFREEORDER -
1224 						    1)
1225 							break;
1226 					}
1227 					/* If not, go to the next block. */
1228 					if (pa < pa_end)
1229 						continue;
1230 				}
1231 
1232 				/*
1233 				 * Determine if the blocks are within the
1234 				 * given range, satisfy the given alignment,
1235 				 * and do not cross the given boundary.
1236 				 */
1237 				pa = VM_PAGE_TO_PHYS(m_ret);
1238 				pa_end = pa + size;
1239 				if (pa >= low && pa_end <= high &&
1240 				    (pa & (alignment - 1)) == 0 &&
1241 				    rounddown2(pa ^ (pa_end - 1), boundary) == 0)
1242 					goto done;
1243 			}
1244 		}
1245 	}
1246 	return (NULL);
1247 done:
1248 	for (m = m_ret; m < &m_ret[npages]; m = &m[1 << oind]) {
1249 		fl = (*seg->free_queues)[m->pool];
1250 		vm_freelist_rem(fl, m, m->order);
1251 	}
1252 	if (m_ret->pool != VM_FREEPOOL_DEFAULT)
1253 		vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m_ret, oind);
1254 	fl = (*seg->free_queues)[m_ret->pool];
1255 	vm_phys_split_pages(m_ret, oind, fl, order);
1256 	/* Return excess pages to the free lists. */
1257 	npages_end = roundup2(npages, 1 << imin(oind, order));
1258 	if (npages < npages_end)
1259 		vm_phys_free_contig(&m_ret[npages], npages_end - npages);
1260 	return (m_ret);
1261 }
1262 
1263 #ifdef DDB
1264 /*
1265  * Show the number of physical pages in each of the free lists.
1266  */
1267 DB_SHOW_COMMAND(freepages, db_show_freepages)
1268 {
1269 	struct vm_freelist *fl;
1270 	int flind, oind, pind, dom;
1271 
1272 	for (dom = 0; dom < vm_ndomains; dom++) {
1273 		db_printf("DOMAIN: %d\n", dom);
1274 		for (flind = 0; flind < vm_nfreelists; flind++) {
1275 			db_printf("FREE LIST %d:\n"
1276 			    "\n  ORDER (SIZE)  |  NUMBER"
1277 			    "\n              ", flind);
1278 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
1279 				db_printf("  |  POOL %d", pind);
1280 			db_printf("\n--            ");
1281 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
1282 				db_printf("-- --      ");
1283 			db_printf("--\n");
1284 			for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
1285 				db_printf("  %2.2d (%6.6dK)", oind,
1286 				    1 << (PAGE_SHIFT - 10 + oind));
1287 				for (pind = 0; pind < VM_NFREEPOOL; pind++) {
1288 				fl = vm_phys_free_queues[dom][flind][pind];
1289 					db_printf("  |  %6.6d", fl[oind].lcnt);
1290 				}
1291 				db_printf("\n");
1292 			}
1293 			db_printf("\n");
1294 		}
1295 		db_printf("\n");
1296 	}
1297 }
1298 #endif
1299