xref: /freebsd/sys/vm/vm_phys.c (revision 370a338a7db27ff9244d2cd24cedf75e992daa80)
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, int tail);
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, listq);
358 	else
359 		TAILQ_INSERT_HEAD(&fl[order].pl, m, listq);
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, listq);
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  * When this function is called by a page allocation function, the caller
593  * should request insertion at the head unless the order [order, oind) queues
594  * are known to be empty.  The objective being to reduce the likelihood of
595  * long-term fragmentation by promoting contemporaneous allocation and
596  * (hopefully) deallocation.
597  */
598 static __inline void
599 vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl, int order,
600     int tail)
601 {
602 	vm_page_t m_buddy;
603 
604 	while (oind > order) {
605 		oind--;
606 		m_buddy = &m[1 << oind];
607 		KASSERT(m_buddy->order == VM_NFREEORDER,
608 		    ("vm_phys_split_pages: page %p has unexpected order %d",
609 		    m_buddy, m_buddy->order));
610 		vm_freelist_add(fl, m_buddy, oind, tail);
611         }
612 }
613 
614 /*
615  * Add the physical pages [m, m + npages) at the end of a power-of-two aligned
616  * and sized set to the specified free list.
617  *
618  * When this function is called by a page allocation function, the caller
619  * should request insertion at the head unless the lower-order queues are
620  * known to be empty.  The objective being to reduce the likelihood of long-
621  * term fragmentation by promoting contemporaneous allocation and (hopefully)
622  * deallocation.
623  *
624  * The physical page m's buddy must not be free.
625  */
626 static void
627 vm_phys_enq_range(vm_page_t m, u_int npages, struct vm_freelist *fl, int tail)
628 {
629 	u_int n;
630 	int order;
631 
632 	KASSERT(npages > 0, ("vm_phys_enq_range: npages is 0"));
633 	KASSERT(((VM_PAGE_TO_PHYS(m) + npages * PAGE_SIZE) &
634 	    ((PAGE_SIZE << (fls(npages) - 1)) - 1)) == 0,
635 	    ("vm_phys_enq_range: page %p and npages %u are misaligned",
636 	    m, npages));
637 	do {
638 		KASSERT(m->order == VM_NFREEORDER,
639 		    ("vm_phys_enq_range: page %p has unexpected order %d",
640 		    m, m->order));
641 		order = ffs(npages) - 1;
642 		KASSERT(order < VM_NFREEORDER,
643 		    ("vm_phys_enq_range: order %d is out of range", order));
644 		vm_freelist_add(fl, m, order, tail);
645 		n = 1 << order;
646 		m += n;
647 		npages -= n;
648 	} while (npages > 0);
649 }
650 
651 /*
652  * Tries to allocate the specified number of pages from the specified pool
653  * within the specified domain.  Returns the actual number of allocated pages
654  * and a pointer to each page through the array ma[].
655  *
656  * The returned pages may not be physically contiguous.  However, in contrast
657  * to performing multiple, back-to-back calls to vm_phys_alloc_pages(..., 0),
658  * calling this function once to allocate the desired number of pages will
659  * avoid wasted time in vm_phys_split_pages().
660  *
661  * The free page queues for the specified domain must be locked.
662  */
663 int
664 vm_phys_alloc_npages(int domain, int pool, int npages, vm_page_t ma[])
665 {
666 	struct vm_freelist *alt, *fl;
667 	vm_page_t m;
668 	int avail, end, flind, freelist, i, need, oind, pind;
669 
670 	KASSERT(domain >= 0 && domain < vm_ndomains,
671 	    ("vm_phys_alloc_npages: domain %d is out of range", domain));
672 	KASSERT(pool < VM_NFREEPOOL,
673 	    ("vm_phys_alloc_npages: pool %d is out of range", pool));
674 	KASSERT(npages <= 1 << (VM_NFREEORDER - 1),
675 	    ("vm_phys_alloc_npages: npages %d is out of range", npages));
676 	vm_domain_free_assert_locked(VM_DOMAIN(domain));
677 	i = 0;
678 	for (freelist = 0; freelist < VM_NFREELIST; freelist++) {
679 		flind = vm_freelist_to_flind[freelist];
680 		if (flind < 0)
681 			continue;
682 		fl = vm_phys_free_queues[domain][flind][pool];
683 		for (oind = 0; oind < VM_NFREEORDER; oind++) {
684 			while ((m = TAILQ_FIRST(&fl[oind].pl)) != NULL) {
685 				vm_freelist_rem(fl, m, oind);
686 				avail = 1 << oind;
687 				need = imin(npages - i, avail);
688 				for (end = i + need; i < end;)
689 					ma[i++] = m++;
690 				if (need < avail) {
691 					/*
692 					 * Return excess pages to fl.  Its
693 					 * order [0, oind) queues are empty.
694 					 */
695 					vm_phys_enq_range(m, avail - need, fl,
696 					    1);
697 					return (npages);
698 				} else if (i == npages)
699 					return (npages);
700 			}
701 		}
702 		for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
703 			for (pind = 0; pind < VM_NFREEPOOL; pind++) {
704 				alt = vm_phys_free_queues[domain][flind][pind];
705 				while ((m = TAILQ_FIRST(&alt[oind].pl)) !=
706 				    NULL) {
707 					vm_freelist_rem(alt, m, oind);
708 					vm_phys_set_pool(pool, m, oind);
709 					avail = 1 << oind;
710 					need = imin(npages - i, avail);
711 					for (end = i + need; i < end;)
712 						ma[i++] = m++;
713 					if (need < avail) {
714 						/*
715 						 * Return excess pages to fl.
716 						 * Its order [0, oind) queues
717 						 * are empty.
718 						 */
719 						vm_phys_enq_range(m, avail -
720 						    need, fl, 1);
721 						return (npages);
722 					} else if (i == npages)
723 						return (npages);
724 				}
725 			}
726 		}
727 	}
728 	return (i);
729 }
730 
731 /*
732  * Allocate a contiguous, power of two-sized set of physical pages
733  * from the free lists.
734  *
735  * The free page queues must be locked.
736  */
737 vm_page_t
738 vm_phys_alloc_pages(int domain, int pool, int order)
739 {
740 	vm_page_t m;
741 	int freelist;
742 
743 	for (freelist = 0; freelist < VM_NFREELIST; freelist++) {
744 		m = vm_phys_alloc_freelist_pages(domain, freelist, pool, order);
745 		if (m != NULL)
746 			return (m);
747 	}
748 	return (NULL);
749 }
750 
751 /*
752  * Allocate a contiguous, power of two-sized set of physical pages from the
753  * specified free list.  The free list must be specified using one of the
754  * manifest constants VM_FREELIST_*.
755  *
756  * The free page queues must be locked.
757  */
758 vm_page_t
759 vm_phys_alloc_freelist_pages(int domain, int freelist, int pool, int order)
760 {
761 	struct vm_freelist *alt, *fl;
762 	vm_page_t m;
763 	int oind, pind, flind;
764 
765 	KASSERT(domain >= 0 && domain < vm_ndomains,
766 	    ("vm_phys_alloc_freelist_pages: domain %d is out of range",
767 	    domain));
768 	KASSERT(freelist < VM_NFREELIST,
769 	    ("vm_phys_alloc_freelist_pages: freelist %d is out of range",
770 	    freelist));
771 	KASSERT(pool < VM_NFREEPOOL,
772 	    ("vm_phys_alloc_freelist_pages: pool %d is out of range", pool));
773 	KASSERT(order < VM_NFREEORDER,
774 	    ("vm_phys_alloc_freelist_pages: order %d is out of range", order));
775 
776 	flind = vm_freelist_to_flind[freelist];
777 	/* Check if freelist is present */
778 	if (flind < 0)
779 		return (NULL);
780 
781 	vm_domain_free_assert_locked(VM_DOMAIN(domain));
782 	fl = &vm_phys_free_queues[domain][flind][pool][0];
783 	for (oind = order; oind < VM_NFREEORDER; oind++) {
784 		m = TAILQ_FIRST(&fl[oind].pl);
785 		if (m != NULL) {
786 			vm_freelist_rem(fl, m, oind);
787 			/* The order [order, oind) queues are empty. */
788 			vm_phys_split_pages(m, oind, fl, order, 1);
789 			return (m);
790 		}
791 	}
792 
793 	/*
794 	 * The given pool was empty.  Find the largest
795 	 * contiguous, power-of-two-sized set of pages in any
796 	 * pool.  Transfer these pages to the given pool, and
797 	 * use them to satisfy the allocation.
798 	 */
799 	for (oind = VM_NFREEORDER - 1; oind >= order; oind--) {
800 		for (pind = 0; pind < VM_NFREEPOOL; pind++) {
801 			alt = &vm_phys_free_queues[domain][flind][pind][0];
802 			m = TAILQ_FIRST(&alt[oind].pl);
803 			if (m != NULL) {
804 				vm_freelist_rem(alt, m, oind);
805 				vm_phys_set_pool(pool, m, oind);
806 				/* The order [order, oind) queues are empty. */
807 				vm_phys_split_pages(m, oind, fl, order, 1);
808 				return (m);
809 			}
810 		}
811 	}
812 	return (NULL);
813 }
814 
815 /*
816  * Find the vm_page corresponding to the given physical address.
817  */
818 vm_page_t
819 vm_phys_paddr_to_vm_page(vm_paddr_t pa)
820 {
821 	struct vm_phys_seg *seg;
822 	int segind;
823 
824 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
825 		seg = &vm_phys_segs[segind];
826 		if (pa >= seg->start && pa < seg->end)
827 			return (&seg->first_page[atop(pa - seg->start)]);
828 	}
829 	return (NULL);
830 }
831 
832 vm_page_t
833 vm_phys_fictitious_to_vm_page(vm_paddr_t pa)
834 {
835 	struct vm_phys_fictitious_seg tmp, *seg;
836 	vm_page_t m;
837 
838 	m = NULL;
839 	tmp.start = pa;
840 	tmp.end = 0;
841 
842 	rw_rlock(&vm_phys_fictitious_reg_lock);
843 	seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
844 	rw_runlock(&vm_phys_fictitious_reg_lock);
845 	if (seg == NULL)
846 		return (NULL);
847 
848 	m = &seg->first_page[atop(pa - seg->start)];
849 	KASSERT((m->flags & PG_FICTITIOUS) != 0, ("%p not fictitious", m));
850 
851 	return (m);
852 }
853 
854 static inline void
855 vm_phys_fictitious_init_range(vm_page_t range, vm_paddr_t start,
856     long page_count, vm_memattr_t memattr)
857 {
858 	long i;
859 
860 	bzero(range, page_count * sizeof(*range));
861 	for (i = 0; i < page_count; i++) {
862 		vm_page_initfake(&range[i], start + PAGE_SIZE * i, memattr);
863 		range[i].oflags &= ~VPO_UNMANAGED;
864 		range[i].busy_lock = VPB_UNBUSIED;
865 	}
866 }
867 
868 int
869 vm_phys_fictitious_reg_range(vm_paddr_t start, vm_paddr_t end,
870     vm_memattr_t memattr)
871 {
872 	struct vm_phys_fictitious_seg *seg;
873 	vm_page_t fp;
874 	long page_count;
875 #ifdef VM_PHYSSEG_DENSE
876 	long pi, pe;
877 	long dpage_count;
878 #endif
879 
880 	KASSERT(start < end,
881 	    ("Start of segment isn't less than end (start: %jx end: %jx)",
882 	    (uintmax_t)start, (uintmax_t)end));
883 
884 	page_count = (end - start) / PAGE_SIZE;
885 
886 #ifdef VM_PHYSSEG_DENSE
887 	pi = atop(start);
888 	pe = atop(end);
889 	if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
890 		fp = &vm_page_array[pi - first_page];
891 		if ((pe - first_page) > vm_page_array_size) {
892 			/*
893 			 * We have a segment that starts inside
894 			 * of vm_page_array, but ends outside of it.
895 			 *
896 			 * Use vm_page_array pages for those that are
897 			 * inside of the vm_page_array range, and
898 			 * allocate the remaining ones.
899 			 */
900 			dpage_count = vm_page_array_size - (pi - first_page);
901 			vm_phys_fictitious_init_range(fp, start, dpage_count,
902 			    memattr);
903 			page_count -= dpage_count;
904 			start += ptoa(dpage_count);
905 			goto alloc;
906 		}
907 		/*
908 		 * We can allocate the full range from vm_page_array,
909 		 * so there's no need to register the range in the tree.
910 		 */
911 		vm_phys_fictitious_init_range(fp, start, page_count, memattr);
912 		return (0);
913 	} else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
914 		/*
915 		 * We have a segment that ends inside of vm_page_array,
916 		 * but starts outside of it.
917 		 */
918 		fp = &vm_page_array[0];
919 		dpage_count = pe - first_page;
920 		vm_phys_fictitious_init_range(fp, ptoa(first_page), dpage_count,
921 		    memattr);
922 		end -= ptoa(dpage_count);
923 		page_count -= dpage_count;
924 		goto alloc;
925 	} else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
926 		/*
927 		 * Trying to register a fictitious range that expands before
928 		 * and after vm_page_array.
929 		 */
930 		return (EINVAL);
931 	} else {
932 alloc:
933 #endif
934 		fp = malloc(page_count * sizeof(struct vm_page), M_FICT_PAGES,
935 		    M_WAITOK);
936 #ifdef VM_PHYSSEG_DENSE
937 	}
938 #endif
939 	vm_phys_fictitious_init_range(fp, start, page_count, memattr);
940 
941 	seg = malloc(sizeof(*seg), M_FICT_PAGES, M_WAITOK | M_ZERO);
942 	seg->start = start;
943 	seg->end = end;
944 	seg->first_page = fp;
945 
946 	rw_wlock(&vm_phys_fictitious_reg_lock);
947 	RB_INSERT(fict_tree, &vm_phys_fictitious_tree, seg);
948 	rw_wunlock(&vm_phys_fictitious_reg_lock);
949 
950 	return (0);
951 }
952 
953 void
954 vm_phys_fictitious_unreg_range(vm_paddr_t start, vm_paddr_t end)
955 {
956 	struct vm_phys_fictitious_seg *seg, tmp;
957 #ifdef VM_PHYSSEG_DENSE
958 	long pi, pe;
959 #endif
960 
961 	KASSERT(start < end,
962 	    ("Start of segment isn't less than end (start: %jx end: %jx)",
963 	    (uintmax_t)start, (uintmax_t)end));
964 
965 #ifdef VM_PHYSSEG_DENSE
966 	pi = atop(start);
967 	pe = atop(end);
968 	if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
969 		if ((pe - first_page) <= vm_page_array_size) {
970 			/*
971 			 * This segment was allocated using vm_page_array
972 			 * only, there's nothing to do since those pages
973 			 * were never added to the tree.
974 			 */
975 			return;
976 		}
977 		/*
978 		 * We have a segment that starts inside
979 		 * of vm_page_array, but ends outside of it.
980 		 *
981 		 * Calculate how many pages were added to the
982 		 * tree and free them.
983 		 */
984 		start = ptoa(first_page + vm_page_array_size);
985 	} else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
986 		/*
987 		 * We have a segment that ends inside of vm_page_array,
988 		 * but starts outside of it.
989 		 */
990 		end = ptoa(first_page);
991 	} else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
992 		/* Since it's not possible to register such a range, panic. */
993 		panic(
994 		    "Unregistering not registered fictitious range [%#jx:%#jx]",
995 		    (uintmax_t)start, (uintmax_t)end);
996 	}
997 #endif
998 	tmp.start = start;
999 	tmp.end = 0;
1000 
1001 	rw_wlock(&vm_phys_fictitious_reg_lock);
1002 	seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
1003 	if (seg->start != start || seg->end != end) {
1004 		rw_wunlock(&vm_phys_fictitious_reg_lock);
1005 		panic(
1006 		    "Unregistering not registered fictitious range [%#jx:%#jx]",
1007 		    (uintmax_t)start, (uintmax_t)end);
1008 	}
1009 	RB_REMOVE(fict_tree, &vm_phys_fictitious_tree, seg);
1010 	rw_wunlock(&vm_phys_fictitious_reg_lock);
1011 	free(seg->first_page, M_FICT_PAGES);
1012 	free(seg, M_FICT_PAGES);
1013 }
1014 
1015 /*
1016  * Free a contiguous, power of two-sized set of physical pages.
1017  *
1018  * The free page queues must be locked.
1019  */
1020 void
1021 vm_phys_free_pages(vm_page_t m, int order)
1022 {
1023 	struct vm_freelist *fl;
1024 	struct vm_phys_seg *seg;
1025 	vm_paddr_t pa;
1026 	vm_page_t m_buddy;
1027 
1028 	KASSERT(m->order == VM_NFREEORDER,
1029 	    ("vm_phys_free_pages: page %p has unexpected order %d",
1030 	    m, m->order));
1031 	KASSERT(m->pool < VM_NFREEPOOL,
1032 	    ("vm_phys_free_pages: page %p has unexpected pool %d",
1033 	    m, m->pool));
1034 	KASSERT(order < VM_NFREEORDER,
1035 	    ("vm_phys_free_pages: order %d is out of range", order));
1036 	seg = &vm_phys_segs[m->segind];
1037 	vm_domain_free_assert_locked(VM_DOMAIN(seg->domain));
1038 	if (order < VM_NFREEORDER - 1) {
1039 		pa = VM_PAGE_TO_PHYS(m);
1040 		do {
1041 			pa ^= ((vm_paddr_t)1 << (PAGE_SHIFT + order));
1042 			if (pa < seg->start || pa >= seg->end)
1043 				break;
1044 			m_buddy = &seg->first_page[atop(pa - seg->start)];
1045 			if (m_buddy->order != order)
1046 				break;
1047 			fl = (*seg->free_queues)[m_buddy->pool];
1048 			vm_freelist_rem(fl, m_buddy, order);
1049 			if (m_buddy->pool != m->pool)
1050 				vm_phys_set_pool(m->pool, m_buddy, order);
1051 			order++;
1052 			pa &= ~(((vm_paddr_t)1 << (PAGE_SHIFT + order)) - 1);
1053 			m = &seg->first_page[atop(pa - seg->start)];
1054 		} while (order < VM_NFREEORDER - 1);
1055 	}
1056 	fl = (*seg->free_queues)[m->pool];
1057 	vm_freelist_add(fl, m, order, 1);
1058 }
1059 
1060 /*
1061  * Free a contiguous, arbitrarily sized set of physical pages.
1062  *
1063  * The free page queues must be locked.
1064  */
1065 void
1066 vm_phys_free_contig(vm_page_t m, u_long npages)
1067 {
1068 	u_int n;
1069 	int order;
1070 
1071 	/*
1072 	 * Avoid unnecessary coalescing by freeing the pages in the largest
1073 	 * possible power-of-two-sized subsets.
1074 	 */
1075 	vm_domain_free_assert_locked(vm_pagequeue_domain(m));
1076 	for (;; npages -= n) {
1077 		/*
1078 		 * Unsigned "min" is used here so that "order" is assigned
1079 		 * "VM_NFREEORDER - 1" when "m"'s physical address is zero
1080 		 * or the low-order bits of its physical address are zero
1081 		 * because the size of a physical address exceeds the size of
1082 		 * a long.
1083 		 */
1084 		order = min(ffsl(VM_PAGE_TO_PHYS(m) >> PAGE_SHIFT) - 1,
1085 		    VM_NFREEORDER - 1);
1086 		n = 1 << order;
1087 		if (npages < n)
1088 			break;
1089 		vm_phys_free_pages(m, order);
1090 		m += n;
1091 	}
1092 	/* The residual "npages" is less than "1 << (VM_NFREEORDER - 1)". */
1093 	for (; npages > 0; npages -= n) {
1094 		order = flsl(npages) - 1;
1095 		n = 1 << order;
1096 		vm_phys_free_pages(m, order);
1097 		m += n;
1098 	}
1099 }
1100 
1101 /*
1102  * Scan physical memory between the specified addresses "low" and "high" for a
1103  * run of contiguous physical pages that satisfy the specified conditions, and
1104  * return the lowest page in the run.  The specified "alignment" determines
1105  * the alignment of the lowest physical page in the run.  If the specified
1106  * "boundary" is non-zero, then the run of physical pages cannot span a
1107  * physical address that is a multiple of "boundary".
1108  *
1109  * "npages" must be greater than zero.  Both "alignment" and "boundary" must
1110  * be a power of two.
1111  */
1112 vm_page_t
1113 vm_phys_scan_contig(int domain, u_long npages, vm_paddr_t low, vm_paddr_t high,
1114     u_long alignment, vm_paddr_t boundary, int options)
1115 {
1116 	vm_paddr_t pa_end;
1117 	vm_page_t m_end, m_run, m_start;
1118 	struct vm_phys_seg *seg;
1119 	int segind;
1120 
1121 	KASSERT(npages > 0, ("npages is 0"));
1122 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1123 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1124 	if (low >= high)
1125 		return (NULL);
1126 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
1127 		seg = &vm_phys_segs[segind];
1128 		if (seg->domain != domain)
1129 			continue;
1130 		if (seg->start >= high)
1131 			break;
1132 		if (low >= seg->end)
1133 			continue;
1134 		if (low <= seg->start)
1135 			m_start = seg->first_page;
1136 		else
1137 			m_start = &seg->first_page[atop(low - seg->start)];
1138 		if (high < seg->end)
1139 			pa_end = high;
1140 		else
1141 			pa_end = seg->end;
1142 		if (pa_end - VM_PAGE_TO_PHYS(m_start) < ptoa(npages))
1143 			continue;
1144 		m_end = &seg->first_page[atop(pa_end - seg->start)];
1145 		m_run = vm_page_scan_contig(npages, m_start, m_end,
1146 		    alignment, boundary, options);
1147 		if (m_run != NULL)
1148 			return (m_run);
1149 	}
1150 	return (NULL);
1151 }
1152 
1153 /*
1154  * Set the pool for a contiguous, power of two-sized set of physical pages.
1155  */
1156 void
1157 vm_phys_set_pool(int pool, vm_page_t m, int order)
1158 {
1159 	vm_page_t m_tmp;
1160 
1161 	for (m_tmp = m; m_tmp < &m[1 << order]; m_tmp++)
1162 		m_tmp->pool = pool;
1163 }
1164 
1165 /*
1166  * Search for the given physical page "m" in the free lists.  If the search
1167  * succeeds, remove "m" from the free lists and return TRUE.  Otherwise, return
1168  * FALSE, indicating that "m" is not in the free lists.
1169  *
1170  * The free page queues must be locked.
1171  */
1172 boolean_t
1173 vm_phys_unfree_page(vm_page_t m)
1174 {
1175 	struct vm_freelist *fl;
1176 	struct vm_phys_seg *seg;
1177 	vm_paddr_t pa, pa_half;
1178 	vm_page_t m_set, m_tmp;
1179 	int order;
1180 
1181 	/*
1182 	 * First, find the contiguous, power of two-sized set of free
1183 	 * physical pages containing the given physical page "m" and
1184 	 * assign it to "m_set".
1185 	 */
1186 	seg = &vm_phys_segs[m->segind];
1187 	vm_domain_free_assert_locked(VM_DOMAIN(seg->domain));
1188 	for (m_set = m, order = 0; m_set->order == VM_NFREEORDER &&
1189 	    order < VM_NFREEORDER - 1; ) {
1190 		order++;
1191 		pa = m->phys_addr & (~(vm_paddr_t)0 << (PAGE_SHIFT + order));
1192 		if (pa >= seg->start)
1193 			m_set = &seg->first_page[atop(pa - seg->start)];
1194 		else
1195 			return (FALSE);
1196 	}
1197 	if (m_set->order < order)
1198 		return (FALSE);
1199 	if (m_set->order == VM_NFREEORDER)
1200 		return (FALSE);
1201 	KASSERT(m_set->order < VM_NFREEORDER,
1202 	    ("vm_phys_unfree_page: page %p has unexpected order %d",
1203 	    m_set, m_set->order));
1204 
1205 	/*
1206 	 * Next, remove "m_set" from the free lists.  Finally, extract
1207 	 * "m" from "m_set" using an iterative algorithm: While "m_set"
1208 	 * is larger than a page, shrink "m_set" by returning the half
1209 	 * of "m_set" that does not contain "m" to the free lists.
1210 	 */
1211 	fl = (*seg->free_queues)[m_set->pool];
1212 	order = m_set->order;
1213 	vm_freelist_rem(fl, m_set, order);
1214 	while (order > 0) {
1215 		order--;
1216 		pa_half = m_set->phys_addr ^ (1 << (PAGE_SHIFT + order));
1217 		if (m->phys_addr < pa_half)
1218 			m_tmp = &seg->first_page[atop(pa_half - seg->start)];
1219 		else {
1220 			m_tmp = m_set;
1221 			m_set = &seg->first_page[atop(pa_half - seg->start)];
1222 		}
1223 		vm_freelist_add(fl, m_tmp, order, 0);
1224 	}
1225 	KASSERT(m_set == m, ("vm_phys_unfree_page: fatal inconsistency"));
1226 	return (TRUE);
1227 }
1228 
1229 /*
1230  * Allocate a contiguous set of physical pages of the given size
1231  * "npages" from the free lists.  All of the physical pages must be at
1232  * or above the given physical address "low" and below the given
1233  * physical address "high".  The given value "alignment" determines the
1234  * alignment of the first physical page in the set.  If the given value
1235  * "boundary" is non-zero, then the set of physical pages cannot cross
1236  * any physical address boundary that is a multiple of that value.  Both
1237  * "alignment" and "boundary" must be a power of two.
1238  */
1239 vm_page_t
1240 vm_phys_alloc_contig(int domain, u_long npages, vm_paddr_t low, vm_paddr_t high,
1241     u_long alignment, vm_paddr_t boundary)
1242 {
1243 	vm_paddr_t pa_end, pa_start;
1244 	vm_page_t m_run;
1245 	struct vm_phys_seg *seg;
1246 	int segind;
1247 
1248 	KASSERT(npages > 0, ("npages is 0"));
1249 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1250 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1251 	vm_domain_free_assert_locked(VM_DOMAIN(domain));
1252 	if (low >= high)
1253 		return (NULL);
1254 	m_run = NULL;
1255 	for (segind = vm_phys_nsegs - 1; segind >= 0; segind--) {
1256 		seg = &vm_phys_segs[segind];
1257 		if (seg->start >= high || seg->domain != domain)
1258 			continue;
1259 		if (low >= seg->end)
1260 			break;
1261 		if (low <= seg->start)
1262 			pa_start = seg->start;
1263 		else
1264 			pa_start = low;
1265 		if (high < seg->end)
1266 			pa_end = high;
1267 		else
1268 			pa_end = seg->end;
1269 		if (pa_end - pa_start < ptoa(npages))
1270 			continue;
1271 		m_run = vm_phys_alloc_seg_contig(seg, npages, low, high,
1272 		    alignment, boundary);
1273 		if (m_run != NULL)
1274 			break;
1275 	}
1276 	return (m_run);
1277 }
1278 
1279 /*
1280  * Allocate a run of contiguous physical pages from the free list for the
1281  * specified segment.
1282  */
1283 static vm_page_t
1284 vm_phys_alloc_seg_contig(struct vm_phys_seg *seg, u_long npages,
1285     vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
1286 {
1287 	struct vm_freelist *fl;
1288 	vm_paddr_t pa, pa_end, size;
1289 	vm_page_t m, m_ret;
1290 	u_long npages_end;
1291 	int oind, order, pind;
1292 
1293 	KASSERT(npages > 0, ("npages is 0"));
1294 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1295 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1296 	vm_domain_free_assert_locked(VM_DOMAIN(seg->domain));
1297 	/* Compute the queue that is the best fit for npages. */
1298 	order = flsl(npages - 1);
1299 	/* Search for a run satisfying the specified conditions. */
1300 	size = npages << PAGE_SHIFT;
1301 	for (oind = min(order, VM_NFREEORDER - 1); oind < VM_NFREEORDER;
1302 	    oind++) {
1303 		for (pind = 0; pind < VM_NFREEPOOL; pind++) {
1304 			fl = (*seg->free_queues)[pind];
1305 			TAILQ_FOREACH(m_ret, &fl[oind].pl, listq) {
1306 				/*
1307 				 * Is the size of this allocation request
1308 				 * larger than the largest block size?
1309 				 */
1310 				if (order >= VM_NFREEORDER) {
1311 					/*
1312 					 * Determine if a sufficient number of
1313 					 * subsequent blocks to satisfy the
1314 					 * allocation request are free.
1315 					 */
1316 					pa = VM_PAGE_TO_PHYS(m_ret);
1317 					pa_end = pa + size;
1318 					if (pa_end < pa)
1319 						continue;
1320 					for (;;) {
1321 						pa += 1 << (PAGE_SHIFT +
1322 						    VM_NFREEORDER - 1);
1323 						if (pa >= pa_end ||
1324 						    pa < seg->start ||
1325 						    pa >= seg->end)
1326 							break;
1327 						m = &seg->first_page[atop(pa -
1328 						    seg->start)];
1329 						if (m->order != VM_NFREEORDER -
1330 						    1)
1331 							break;
1332 					}
1333 					/* If not, go to the next block. */
1334 					if (pa < pa_end)
1335 						continue;
1336 				}
1337 
1338 				/*
1339 				 * Determine if the blocks are within the
1340 				 * given range, satisfy the given alignment,
1341 				 * and do not cross the given boundary.
1342 				 */
1343 				pa = VM_PAGE_TO_PHYS(m_ret);
1344 				pa_end = pa + size;
1345 				if (pa >= low && pa_end <= high &&
1346 				    (pa & (alignment - 1)) == 0 &&
1347 				    rounddown2(pa ^ (pa_end - 1), boundary) == 0)
1348 					goto done;
1349 			}
1350 		}
1351 	}
1352 	return (NULL);
1353 done:
1354 	for (m = m_ret; m < &m_ret[npages]; m = &m[1 << oind]) {
1355 		fl = (*seg->free_queues)[m->pool];
1356 		vm_freelist_rem(fl, m, oind);
1357 		if (m->pool != VM_FREEPOOL_DEFAULT)
1358 			vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, oind);
1359 	}
1360 	/* Return excess pages to the free lists. */
1361 	npages_end = roundup2(npages, 1 << oind);
1362 	if (npages < npages_end) {
1363 		fl = (*seg->free_queues)[VM_FREEPOOL_DEFAULT];
1364 		vm_phys_enq_range(&m_ret[npages], npages_end - npages, fl, 0);
1365 	}
1366 	return (m_ret);
1367 }
1368 
1369 #ifdef DDB
1370 /*
1371  * Show the number of physical pages in each of the free lists.
1372  */
1373 DB_SHOW_COMMAND(freepages, db_show_freepages)
1374 {
1375 	struct vm_freelist *fl;
1376 	int flind, oind, pind, dom;
1377 
1378 	for (dom = 0; dom < vm_ndomains; dom++) {
1379 		db_printf("DOMAIN: %d\n", dom);
1380 		for (flind = 0; flind < vm_nfreelists; flind++) {
1381 			db_printf("FREE LIST %d:\n"
1382 			    "\n  ORDER (SIZE)  |  NUMBER"
1383 			    "\n              ", flind);
1384 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
1385 				db_printf("  |  POOL %d", pind);
1386 			db_printf("\n--            ");
1387 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
1388 				db_printf("-- --      ");
1389 			db_printf("--\n");
1390 			for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
1391 				db_printf("  %2.2d (%6.6dK)", oind,
1392 				    1 << (PAGE_SHIFT - 10 + oind));
1393 				for (pind = 0; pind < VM_NFREEPOOL; pind++) {
1394 				fl = vm_phys_free_queues[dom][flind][pind];
1395 					db_printf("  |  %6.6d", fl[oind].lcnt);
1396 				}
1397 				db_printf("\n");
1398 			}
1399 			db_printf("\n");
1400 		}
1401 		db_printf("\n");
1402 	}
1403 }
1404 #endif
1405