xref: /freebsd/sys/vm/vm_phys.c (revision f93f7cf199b6b07464760dbbbcae84edead6e1ee)
1 /*-
2  * Copyright (c) 2002-2006 Rice University
3  * Copyright (c) 2007 Alan L. Cox <alc@cs.rice.edu>
4  * All rights reserved.
5  *
6  * This software was developed for the FreeBSD Project by Alan L. Cox,
7  * Olivier Crameri, Peter Druschel, Sitaram Iyer, and Juan Navarro.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
22  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
25  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
28  * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  *	Physical memory system implementation
34  *
35  * Any external functions defined by this module are only to be used by the
36  * virtual memory system.
37  */
38 
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include "opt_ddb.h"
43 #include "opt_vm.h"
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/lock.h>
48 #include <sys/kernel.h>
49 #include <sys/malloc.h>
50 #include <sys/mutex.h>
51 #include <sys/proc.h>
52 #include <sys/queue.h>
53 #include <sys/rwlock.h>
54 #include <sys/sbuf.h>
55 #include <sys/sysctl.h>
56 #include <sys/tree.h>
57 #include <sys/vmmeter.h>
58 #include <sys/seq.h>
59 
60 #include <ddb/ddb.h>
61 
62 #include <vm/vm.h>
63 #include <vm/vm_param.h>
64 #include <vm/vm_kern.h>
65 #include <vm/vm_object.h>
66 #include <vm/vm_page.h>
67 #include <vm/vm_phys.h>
68 
69 #include <vm/vm_domain.h>
70 
71 _Static_assert(sizeof(long) * NBBY >= VM_PHYSSEG_MAX,
72     "Too many physsegs.");
73 
74 #ifdef VM_NUMA_ALLOC
75 struct mem_affinity *mem_affinity;
76 int *mem_locality;
77 #endif
78 
79 int vm_ndomains = 1;
80 
81 struct vm_phys_seg vm_phys_segs[VM_PHYSSEG_MAX];
82 int vm_phys_nsegs;
83 
84 struct vm_phys_fictitious_seg;
85 static int vm_phys_fictitious_cmp(struct vm_phys_fictitious_seg *,
86     struct vm_phys_fictitious_seg *);
87 
88 RB_HEAD(fict_tree, vm_phys_fictitious_seg) vm_phys_fictitious_tree =
89     RB_INITIALIZER(_vm_phys_fictitious_tree);
90 
91 struct vm_phys_fictitious_seg {
92 	RB_ENTRY(vm_phys_fictitious_seg) node;
93 	/* Memory region data */
94 	vm_paddr_t	start;
95 	vm_paddr_t	end;
96 	vm_page_t	first_page;
97 };
98 
99 RB_GENERATE_STATIC(fict_tree, vm_phys_fictitious_seg, node,
100     vm_phys_fictitious_cmp);
101 
102 static struct rwlock vm_phys_fictitious_reg_lock;
103 MALLOC_DEFINE(M_FICT_PAGES, "vm_fictitious", "Fictitious VM pages");
104 
105 static struct vm_freelist
106     vm_phys_free_queues[MAXMEMDOM][VM_NFREELIST][VM_NFREEPOOL][VM_NFREEORDER];
107 
108 static int vm_nfreelists;
109 
110 /*
111  * Provides the mapping from VM_FREELIST_* to free list indices (flind).
112  */
113 static int vm_freelist_to_flind[VM_NFREELIST];
114 
115 CTASSERT(VM_FREELIST_DEFAULT == 0);
116 
117 #ifdef VM_FREELIST_ISADMA
118 #define	VM_ISADMA_BOUNDARY	16777216
119 #endif
120 #ifdef VM_FREELIST_DMA32
121 #define	VM_DMA32_BOUNDARY	((vm_paddr_t)1 << 32)
122 #endif
123 
124 /*
125  * Enforce the assumptions made by vm_phys_add_seg() and vm_phys_init() about
126  * the ordering of the free list boundaries.
127  */
128 #if defined(VM_ISADMA_BOUNDARY) && defined(VM_LOWMEM_BOUNDARY)
129 CTASSERT(VM_ISADMA_BOUNDARY < VM_LOWMEM_BOUNDARY);
130 #endif
131 #if defined(VM_LOWMEM_BOUNDARY) && defined(VM_DMA32_BOUNDARY)
132 CTASSERT(VM_LOWMEM_BOUNDARY < VM_DMA32_BOUNDARY);
133 #endif
134 
135 static int sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS);
136 SYSCTL_OID(_vm, OID_AUTO, phys_free, CTLTYPE_STRING | CTLFLAG_RD,
137     NULL, 0, sysctl_vm_phys_free, "A", "Phys Free Info");
138 
139 static int sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS);
140 SYSCTL_OID(_vm, OID_AUTO, phys_segs, CTLTYPE_STRING | CTLFLAG_RD,
141     NULL, 0, sysctl_vm_phys_segs, "A", "Phys Seg Info");
142 
143 #ifdef VM_NUMA_ALLOC
144 static int sysctl_vm_phys_locality(SYSCTL_HANDLER_ARGS);
145 SYSCTL_OID(_vm, OID_AUTO, phys_locality, CTLTYPE_STRING | CTLFLAG_RD,
146     NULL, 0, sysctl_vm_phys_locality, "A", "Phys Locality Info");
147 #endif
148 
149 SYSCTL_INT(_vm, OID_AUTO, ndomains, CTLFLAG_RD,
150     &vm_ndomains, 0, "Number of physical memory domains available.");
151 
152 /*
153  * Default to first-touch + round-robin.
154  */
155 static struct mtx vm_default_policy_mtx;
156 MTX_SYSINIT(vm_default_policy, &vm_default_policy_mtx, "default policy mutex",
157     MTX_DEF);
158 #ifdef VM_NUMA_ALLOC
159 static struct vm_domain_policy vm_default_policy =
160     VM_DOMAIN_POLICY_STATIC_INITIALISER(VM_POLICY_FIRST_TOUCH_ROUND_ROBIN, 0);
161 #else
162 /* Use round-robin so the domain policy code will only try once per allocation */
163 static struct vm_domain_policy vm_default_policy =
164     VM_DOMAIN_POLICY_STATIC_INITIALISER(VM_POLICY_ROUND_ROBIN, 0);
165 #endif
166 
167 static vm_page_t vm_phys_alloc_domain_pages(int domain, int flind, int pool,
168     int order);
169 static vm_page_t vm_phys_alloc_seg_contig(struct vm_phys_seg *seg,
170     u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
171     vm_paddr_t boundary);
172 static void _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int domain);
173 static void vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end);
174 static int vm_phys_paddr_to_segind(vm_paddr_t pa);
175 static void vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl,
176     int order);
177 
178 static int
179 sysctl_vm_default_policy(SYSCTL_HANDLER_ARGS)
180 {
181 	char policy_name[32];
182 	int error;
183 
184 	mtx_lock(&vm_default_policy_mtx);
185 
186 	/* Map policy to output string */
187 	switch (vm_default_policy.p.policy) {
188 	case VM_POLICY_FIRST_TOUCH:
189 		strcpy(policy_name, "first-touch");
190 		break;
191 	case VM_POLICY_FIRST_TOUCH_ROUND_ROBIN:
192 		strcpy(policy_name, "first-touch-rr");
193 		break;
194 	case VM_POLICY_ROUND_ROBIN:
195 	default:
196 		strcpy(policy_name, "rr");
197 		break;
198 	}
199 	mtx_unlock(&vm_default_policy_mtx);
200 
201 	error = sysctl_handle_string(oidp, &policy_name[0],
202 	    sizeof(policy_name), req);
203 	if (error != 0 || req->newptr == NULL)
204 		return (error);
205 
206 	mtx_lock(&vm_default_policy_mtx);
207 	/* Set: match on the subset of policies that make sense as a default */
208 	if (strcmp("first-touch-rr", policy_name) == 0) {
209 		vm_domain_policy_set(&vm_default_policy,
210 		    VM_POLICY_FIRST_TOUCH_ROUND_ROBIN, 0);
211 	} else if (strcmp("first-touch", policy_name) == 0) {
212 		vm_domain_policy_set(&vm_default_policy,
213 		    VM_POLICY_FIRST_TOUCH, 0);
214 	} else if (strcmp("rr", policy_name) == 0) {
215 		vm_domain_policy_set(&vm_default_policy,
216 		    VM_POLICY_ROUND_ROBIN, 0);
217 	} else {
218 		error = EINVAL;
219 		goto finish;
220 	}
221 
222 	error = 0;
223 finish:
224 	mtx_unlock(&vm_default_policy_mtx);
225 	return (error);
226 }
227 
228 SYSCTL_PROC(_vm, OID_AUTO, default_policy, CTLTYPE_STRING | CTLFLAG_RW,
229     0, 0, sysctl_vm_default_policy, "A",
230     "Default policy (rr, first-touch, first-touch-rr");
231 
232 /*
233  * Red-black tree helpers for vm fictitious range management.
234  */
235 static inline int
236 vm_phys_fictitious_in_range(struct vm_phys_fictitious_seg *p,
237     struct vm_phys_fictitious_seg *range)
238 {
239 
240 	KASSERT(range->start != 0 && range->end != 0,
241 	    ("Invalid range passed on search for vm_fictitious page"));
242 	if (p->start >= range->end)
243 		return (1);
244 	if (p->start < range->start)
245 		return (-1);
246 
247 	return (0);
248 }
249 
250 static int
251 vm_phys_fictitious_cmp(struct vm_phys_fictitious_seg *p1,
252     struct vm_phys_fictitious_seg *p2)
253 {
254 
255 	/* Check if this is a search for a page */
256 	if (p1->end == 0)
257 		return (vm_phys_fictitious_in_range(p1, p2));
258 
259 	KASSERT(p2->end != 0,
260     ("Invalid range passed as second parameter to vm fictitious comparison"));
261 
262 	/* Searching to add a new range */
263 	if (p1->end <= p2->start)
264 		return (-1);
265 	if (p1->start >= p2->end)
266 		return (1);
267 
268 	panic("Trying to add overlapping vm fictitious ranges:\n"
269 	    "[%#jx:%#jx] and [%#jx:%#jx]", (uintmax_t)p1->start,
270 	    (uintmax_t)p1->end, (uintmax_t)p2->start, (uintmax_t)p2->end);
271 }
272 
273 #ifdef notyet
274 static __inline int
275 vm_rr_selectdomain(void)
276 {
277 #ifdef VM_NUMA_ALLOC
278 	struct thread *td;
279 
280 	td = curthread;
281 
282 	td->td_dom_rr_idx++;
283 	td->td_dom_rr_idx %= vm_ndomains;
284 	return (td->td_dom_rr_idx);
285 #else
286 	return (0);
287 #endif
288 }
289 #endif /* notyet */
290 
291 /*
292  * Initialise a VM domain iterator.
293  *
294  * Check the thread policy, then the proc policy,
295  * then default to the system policy.
296  *
297  * Later on the various layers will have this logic
298  * plumbed into them and the phys code will be explicitly
299  * handed a VM domain policy to use.
300  */
301 static void
302 vm_policy_iterator_init(struct vm_domain_iterator *vi)
303 {
304 #ifdef VM_NUMA_ALLOC
305 	struct vm_domain_policy lcl;
306 #endif
307 
308 	vm_domain_iterator_init(vi);
309 
310 #ifdef VM_NUMA_ALLOC
311 	/* Copy out the thread policy */
312 	vm_domain_policy_localcopy(&lcl, &curthread->td_vm_dom_policy);
313 	if (lcl.p.policy != VM_POLICY_NONE) {
314 		/* Thread policy is present; use it */
315 		vm_domain_iterator_set_policy(vi, &lcl);
316 		return;
317 	}
318 
319 	vm_domain_policy_localcopy(&lcl,
320 	    &curthread->td_proc->p_vm_dom_policy);
321 	if (lcl.p.policy != VM_POLICY_NONE) {
322 		/* Process policy is present; use it */
323 		vm_domain_iterator_set_policy(vi, &lcl);
324 		return;
325 	}
326 #endif
327 	/* Use system default policy */
328 	vm_domain_iterator_set_policy(vi, &vm_default_policy);
329 }
330 
331 static void
332 vm_policy_iterator_finish(struct vm_domain_iterator *vi)
333 {
334 
335 	vm_domain_iterator_cleanup(vi);
336 }
337 
338 boolean_t
339 vm_phys_domain_intersects(long mask, vm_paddr_t low, vm_paddr_t high)
340 {
341 	struct vm_phys_seg *s;
342 	int idx;
343 
344 	while ((idx = ffsl(mask)) != 0) {
345 		idx--;	/* ffsl counts from 1 */
346 		mask &= ~(1UL << idx);
347 		s = &vm_phys_segs[idx];
348 		if (low < s->end && high > s->start)
349 			return (TRUE);
350 	}
351 	return (FALSE);
352 }
353 
354 /*
355  * Outputs the state of the physical memory allocator, specifically,
356  * the amount of physical memory in each free list.
357  */
358 static int
359 sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS)
360 {
361 	struct sbuf sbuf;
362 	struct vm_freelist *fl;
363 	int dom, error, flind, oind, pind;
364 
365 	error = sysctl_wire_old_buffer(req, 0);
366 	if (error != 0)
367 		return (error);
368 	sbuf_new_for_sysctl(&sbuf, NULL, 128 * vm_ndomains, req);
369 	for (dom = 0; dom < vm_ndomains; dom++) {
370 		sbuf_printf(&sbuf,"\nDOMAIN %d:\n", dom);
371 		for (flind = 0; flind < vm_nfreelists; flind++) {
372 			sbuf_printf(&sbuf, "\nFREE LIST %d:\n"
373 			    "\n  ORDER (SIZE)  |  NUMBER"
374 			    "\n              ", flind);
375 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
376 				sbuf_printf(&sbuf, "  |  POOL %d", pind);
377 			sbuf_printf(&sbuf, "\n--            ");
378 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
379 				sbuf_printf(&sbuf, "-- --      ");
380 			sbuf_printf(&sbuf, "--\n");
381 			for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
382 				sbuf_printf(&sbuf, "  %2d (%6dK)", oind,
383 				    1 << (PAGE_SHIFT - 10 + oind));
384 				for (pind = 0; pind < VM_NFREEPOOL; pind++) {
385 				fl = vm_phys_free_queues[dom][flind][pind];
386 					sbuf_printf(&sbuf, "  |  %6d",
387 					    fl[oind].lcnt);
388 				}
389 				sbuf_printf(&sbuf, "\n");
390 			}
391 		}
392 	}
393 	error = sbuf_finish(&sbuf);
394 	sbuf_delete(&sbuf);
395 	return (error);
396 }
397 
398 /*
399  * Outputs the set of physical memory segments.
400  */
401 static int
402 sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS)
403 {
404 	struct sbuf sbuf;
405 	struct vm_phys_seg *seg;
406 	int error, segind;
407 
408 	error = sysctl_wire_old_buffer(req, 0);
409 	if (error != 0)
410 		return (error);
411 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
412 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
413 		sbuf_printf(&sbuf, "\nSEGMENT %d:\n\n", segind);
414 		seg = &vm_phys_segs[segind];
415 		sbuf_printf(&sbuf, "start:     %#jx\n",
416 		    (uintmax_t)seg->start);
417 		sbuf_printf(&sbuf, "end:       %#jx\n",
418 		    (uintmax_t)seg->end);
419 		sbuf_printf(&sbuf, "domain:    %d\n", seg->domain);
420 		sbuf_printf(&sbuf, "free list: %p\n", seg->free_queues);
421 	}
422 	error = sbuf_finish(&sbuf);
423 	sbuf_delete(&sbuf);
424 	return (error);
425 }
426 
427 /*
428  * Return affinity, or -1 if there's no affinity information.
429  */
430 int
431 vm_phys_mem_affinity(int f, int t)
432 {
433 
434 #ifdef VM_NUMA_ALLOC
435 	if (mem_locality == NULL)
436 		return (-1);
437 	if (f >= vm_ndomains || t >= vm_ndomains)
438 		return (-1);
439 	return (mem_locality[f * vm_ndomains + t]);
440 #else
441 	return (-1);
442 #endif
443 }
444 
445 #ifdef VM_NUMA_ALLOC
446 /*
447  * Outputs the VM locality table.
448  */
449 static int
450 sysctl_vm_phys_locality(SYSCTL_HANDLER_ARGS)
451 {
452 	struct sbuf sbuf;
453 	int error, i, j;
454 
455 	error = sysctl_wire_old_buffer(req, 0);
456 	if (error != 0)
457 		return (error);
458 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
459 
460 	sbuf_printf(&sbuf, "\n");
461 
462 	for (i = 0; i < vm_ndomains; i++) {
463 		sbuf_printf(&sbuf, "%d: ", i);
464 		for (j = 0; j < vm_ndomains; j++) {
465 			sbuf_printf(&sbuf, "%d ", vm_phys_mem_affinity(i, j));
466 		}
467 		sbuf_printf(&sbuf, "\n");
468 	}
469 	error = sbuf_finish(&sbuf);
470 	sbuf_delete(&sbuf);
471 	return (error);
472 }
473 #endif
474 
475 static void
476 vm_freelist_add(struct vm_freelist *fl, vm_page_t m, int order, int tail)
477 {
478 
479 	m->order = order;
480 	if (tail)
481 		TAILQ_INSERT_TAIL(&fl[order].pl, m, plinks.q);
482 	else
483 		TAILQ_INSERT_HEAD(&fl[order].pl, m, plinks.q);
484 	fl[order].lcnt++;
485 }
486 
487 static void
488 vm_freelist_rem(struct vm_freelist *fl, vm_page_t m, int order)
489 {
490 
491 	TAILQ_REMOVE(&fl[order].pl, m, plinks.q);
492 	fl[order].lcnt--;
493 	m->order = VM_NFREEORDER;
494 }
495 
496 /*
497  * Create a physical memory segment.
498  */
499 static void
500 _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int domain)
501 {
502 	struct vm_phys_seg *seg;
503 
504 	KASSERT(vm_phys_nsegs < VM_PHYSSEG_MAX,
505 	    ("vm_phys_create_seg: increase VM_PHYSSEG_MAX"));
506 	KASSERT(domain < vm_ndomains,
507 	    ("vm_phys_create_seg: invalid domain provided"));
508 	seg = &vm_phys_segs[vm_phys_nsegs++];
509 	while (seg > vm_phys_segs && (seg - 1)->start >= end) {
510 		*seg = *(seg - 1);
511 		seg--;
512 	}
513 	seg->start = start;
514 	seg->end = end;
515 	seg->domain = domain;
516 }
517 
518 static void
519 vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end)
520 {
521 #ifdef VM_NUMA_ALLOC
522 	int i;
523 
524 	if (mem_affinity == NULL) {
525 		_vm_phys_create_seg(start, end, 0);
526 		return;
527 	}
528 
529 	for (i = 0;; i++) {
530 		if (mem_affinity[i].end == 0)
531 			panic("Reached end of affinity info");
532 		if (mem_affinity[i].end <= start)
533 			continue;
534 		if (mem_affinity[i].start > start)
535 			panic("No affinity info for start %jx",
536 			    (uintmax_t)start);
537 		if (mem_affinity[i].end >= end) {
538 			_vm_phys_create_seg(start, end,
539 			    mem_affinity[i].domain);
540 			break;
541 		}
542 		_vm_phys_create_seg(start, mem_affinity[i].end,
543 		    mem_affinity[i].domain);
544 		start = mem_affinity[i].end;
545 	}
546 #else
547 	_vm_phys_create_seg(start, end, 0);
548 #endif
549 }
550 
551 /*
552  * Add a physical memory segment.
553  */
554 void
555 vm_phys_add_seg(vm_paddr_t start, vm_paddr_t end)
556 {
557 	vm_paddr_t paddr;
558 
559 	KASSERT((start & PAGE_MASK) == 0,
560 	    ("vm_phys_define_seg: start is not page aligned"));
561 	KASSERT((end & PAGE_MASK) == 0,
562 	    ("vm_phys_define_seg: end is not page aligned"));
563 
564 	/*
565 	 * Split the physical memory segment if it spans two or more free
566 	 * list boundaries.
567 	 */
568 	paddr = start;
569 #ifdef	VM_FREELIST_ISADMA
570 	if (paddr < VM_ISADMA_BOUNDARY && end > VM_ISADMA_BOUNDARY) {
571 		vm_phys_create_seg(paddr, VM_ISADMA_BOUNDARY);
572 		paddr = VM_ISADMA_BOUNDARY;
573 	}
574 #endif
575 #ifdef	VM_FREELIST_LOWMEM
576 	if (paddr < VM_LOWMEM_BOUNDARY && end > VM_LOWMEM_BOUNDARY) {
577 		vm_phys_create_seg(paddr, VM_LOWMEM_BOUNDARY);
578 		paddr = VM_LOWMEM_BOUNDARY;
579 	}
580 #endif
581 #ifdef	VM_FREELIST_DMA32
582 	if (paddr < VM_DMA32_BOUNDARY && end > VM_DMA32_BOUNDARY) {
583 		vm_phys_create_seg(paddr, VM_DMA32_BOUNDARY);
584 		paddr = VM_DMA32_BOUNDARY;
585 	}
586 #endif
587 	vm_phys_create_seg(paddr, end);
588 }
589 
590 /*
591  * Initialize the physical memory allocator.
592  *
593  * Requires that vm_page_array is initialized!
594  */
595 void
596 vm_phys_init(void)
597 {
598 	struct vm_freelist *fl;
599 	struct vm_phys_seg *seg;
600 	u_long npages;
601 	int dom, flind, freelist, oind, pind, segind;
602 
603 	/*
604 	 * Compute the number of free lists, and generate the mapping from the
605 	 * manifest constants VM_FREELIST_* to the free list indices.
606 	 *
607 	 * Initially, the entries of vm_freelist_to_flind[] are set to either
608 	 * 0 or 1 to indicate which free lists should be created.
609 	 */
610 	npages = 0;
611 	for (segind = vm_phys_nsegs - 1; segind >= 0; segind--) {
612 		seg = &vm_phys_segs[segind];
613 #ifdef	VM_FREELIST_ISADMA
614 		if (seg->end <= VM_ISADMA_BOUNDARY)
615 			vm_freelist_to_flind[VM_FREELIST_ISADMA] = 1;
616 		else
617 #endif
618 #ifdef	VM_FREELIST_LOWMEM
619 		if (seg->end <= VM_LOWMEM_BOUNDARY)
620 			vm_freelist_to_flind[VM_FREELIST_LOWMEM] = 1;
621 		else
622 #endif
623 #ifdef	VM_FREELIST_DMA32
624 		if (
625 #ifdef	VM_DMA32_NPAGES_THRESHOLD
626 		    /*
627 		     * Create the DMA32 free list only if the amount of
628 		     * physical memory above physical address 4G exceeds the
629 		     * given threshold.
630 		     */
631 		    npages > VM_DMA32_NPAGES_THRESHOLD &&
632 #endif
633 		    seg->end <= VM_DMA32_BOUNDARY)
634 			vm_freelist_to_flind[VM_FREELIST_DMA32] = 1;
635 		else
636 #endif
637 		{
638 			npages += atop(seg->end - seg->start);
639 			vm_freelist_to_flind[VM_FREELIST_DEFAULT] = 1;
640 		}
641 	}
642 	/* Change each entry into a running total of the free lists. */
643 	for (freelist = 1; freelist < VM_NFREELIST; freelist++) {
644 		vm_freelist_to_flind[freelist] +=
645 		    vm_freelist_to_flind[freelist - 1];
646 	}
647 	vm_nfreelists = vm_freelist_to_flind[VM_NFREELIST - 1];
648 	KASSERT(vm_nfreelists > 0, ("vm_phys_init: no free lists"));
649 	/* Change each entry into a free list index. */
650 	for (freelist = 0; freelist < VM_NFREELIST; freelist++)
651 		vm_freelist_to_flind[freelist]--;
652 
653 	/*
654 	 * Initialize the first_page and free_queues fields of each physical
655 	 * memory segment.
656 	 */
657 #ifdef VM_PHYSSEG_SPARSE
658 	npages = 0;
659 #endif
660 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
661 		seg = &vm_phys_segs[segind];
662 #ifdef VM_PHYSSEG_SPARSE
663 		seg->first_page = &vm_page_array[npages];
664 		npages += atop(seg->end - seg->start);
665 #else
666 		seg->first_page = PHYS_TO_VM_PAGE(seg->start);
667 #endif
668 #ifdef	VM_FREELIST_ISADMA
669 		if (seg->end <= VM_ISADMA_BOUNDARY) {
670 			flind = vm_freelist_to_flind[VM_FREELIST_ISADMA];
671 			KASSERT(flind >= 0,
672 			    ("vm_phys_init: ISADMA flind < 0"));
673 		} else
674 #endif
675 #ifdef	VM_FREELIST_LOWMEM
676 		if (seg->end <= VM_LOWMEM_BOUNDARY) {
677 			flind = vm_freelist_to_flind[VM_FREELIST_LOWMEM];
678 			KASSERT(flind >= 0,
679 			    ("vm_phys_init: LOWMEM flind < 0"));
680 		} else
681 #endif
682 #ifdef	VM_FREELIST_DMA32
683 		if (seg->end <= VM_DMA32_BOUNDARY) {
684 			flind = vm_freelist_to_flind[VM_FREELIST_DMA32];
685 			KASSERT(flind >= 0,
686 			    ("vm_phys_init: DMA32 flind < 0"));
687 		} else
688 #endif
689 		{
690 			flind = vm_freelist_to_flind[VM_FREELIST_DEFAULT];
691 			KASSERT(flind >= 0,
692 			    ("vm_phys_init: DEFAULT flind < 0"));
693 		}
694 		seg->free_queues = &vm_phys_free_queues[seg->domain][flind];
695 	}
696 
697 	/*
698 	 * Initialize the free queues.
699 	 */
700 	for (dom = 0; dom < vm_ndomains; dom++) {
701 		for (flind = 0; flind < vm_nfreelists; flind++) {
702 			for (pind = 0; pind < VM_NFREEPOOL; pind++) {
703 				fl = vm_phys_free_queues[dom][flind][pind];
704 				for (oind = 0; oind < VM_NFREEORDER; oind++)
705 					TAILQ_INIT(&fl[oind].pl);
706 			}
707 		}
708 	}
709 
710 	rw_init(&vm_phys_fictitious_reg_lock, "vmfctr");
711 }
712 
713 /*
714  * Split a contiguous, power of two-sized set of physical pages.
715  */
716 static __inline void
717 vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl, int order)
718 {
719 	vm_page_t m_buddy;
720 
721 	while (oind > order) {
722 		oind--;
723 		m_buddy = &m[1 << oind];
724 		KASSERT(m_buddy->order == VM_NFREEORDER,
725 		    ("vm_phys_split_pages: page %p has unexpected order %d",
726 		    m_buddy, m_buddy->order));
727 		vm_freelist_add(fl, m_buddy, oind, 0);
728         }
729 }
730 
731 /*
732  * Initialize a physical page in preparation for adding it to the free
733  * lists.
734  */
735 void
736 vm_phys_init_page(vm_paddr_t pa)
737 {
738 	vm_page_t m;
739 
740 	m = vm_phys_paddr_to_vm_page(pa);
741 	m->object = NULL;
742 	m->wire_count = 0;
743 	m->busy_lock = VPB_UNBUSIED;
744 	m->hold_count = 0;
745 	m->flags = m->aflags = m->oflags = 0;
746 	m->phys_addr = pa;
747 	m->queue = PQ_NONE;
748 	m->psind = 0;
749 	m->segind = vm_phys_paddr_to_segind(pa);
750 	m->order = VM_NFREEORDER;
751 	m->pool = VM_FREEPOOL_DEFAULT;
752 	m->valid = m->dirty = 0;
753 	pmap_page_init(m);
754 }
755 
756 /*
757  * Allocate a contiguous, power of two-sized set of physical pages
758  * from the free lists.
759  *
760  * The free page queues must be locked.
761  */
762 vm_page_t
763 vm_phys_alloc_pages(int pool, int order)
764 {
765 	vm_page_t m;
766 	int domain, flind;
767 	struct vm_domain_iterator vi;
768 
769 	KASSERT(pool < VM_NFREEPOOL,
770 	    ("vm_phys_alloc_pages: pool %d is out of range", pool));
771 	KASSERT(order < VM_NFREEORDER,
772 	    ("vm_phys_alloc_pages: order %d is out of range", order));
773 
774 	vm_policy_iterator_init(&vi);
775 
776 	while ((vm_domain_iterator_run(&vi, &domain)) == 0) {
777 		for (flind = 0; flind < vm_nfreelists; flind++) {
778 			m = vm_phys_alloc_domain_pages(domain, flind, pool,
779 			    order);
780 			if (m != NULL)
781 				return (m);
782 		}
783 	}
784 
785 	vm_policy_iterator_finish(&vi);
786 	return (NULL);
787 }
788 
789 /*
790  * Allocate a contiguous, power of two-sized set of physical pages from the
791  * specified free list.  The free list must be specified using one of the
792  * manifest constants VM_FREELIST_*.
793  *
794  * The free page queues must be locked.
795  */
796 vm_page_t
797 vm_phys_alloc_freelist_pages(int freelist, int pool, int order)
798 {
799 	vm_page_t m;
800 	struct vm_domain_iterator vi;
801 	int domain;
802 
803 	KASSERT(freelist < VM_NFREELIST,
804 	    ("vm_phys_alloc_freelist_pages: freelist %d is out of range",
805 	    freelist));
806 	KASSERT(pool < VM_NFREEPOOL,
807 	    ("vm_phys_alloc_freelist_pages: pool %d is out of range", pool));
808 	KASSERT(order < VM_NFREEORDER,
809 	    ("vm_phys_alloc_freelist_pages: order %d is out of range", order));
810 
811 	vm_policy_iterator_init(&vi);
812 
813 	while ((vm_domain_iterator_run(&vi, &domain)) == 0) {
814 		m = vm_phys_alloc_domain_pages(domain,
815 		    vm_freelist_to_flind[freelist], pool, order);
816 		if (m != NULL)
817 			return (m);
818 	}
819 
820 	vm_policy_iterator_finish(&vi);
821 	return (NULL);
822 }
823 
824 static vm_page_t
825 vm_phys_alloc_domain_pages(int domain, int flind, int pool, int order)
826 {
827 	struct vm_freelist *fl;
828 	struct vm_freelist *alt;
829 	int oind, pind;
830 	vm_page_t m;
831 
832 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
833 	fl = &vm_phys_free_queues[domain][flind][pool][0];
834 	for (oind = order; oind < VM_NFREEORDER; oind++) {
835 		m = TAILQ_FIRST(&fl[oind].pl);
836 		if (m != NULL) {
837 			vm_freelist_rem(fl, m, oind);
838 			vm_phys_split_pages(m, oind, fl, order);
839 			return (m);
840 		}
841 	}
842 
843 	/*
844 	 * The given pool was empty.  Find the largest
845 	 * contiguous, power-of-two-sized set of pages in any
846 	 * pool.  Transfer these pages to the given pool, and
847 	 * use them to satisfy the allocation.
848 	 */
849 	for (oind = VM_NFREEORDER - 1; oind >= order; oind--) {
850 		for (pind = 0; pind < VM_NFREEPOOL; pind++) {
851 			alt = &vm_phys_free_queues[domain][flind][pind][0];
852 			m = TAILQ_FIRST(&alt[oind].pl);
853 			if (m != NULL) {
854 				vm_freelist_rem(alt, m, oind);
855 				vm_phys_set_pool(pool, m, oind);
856 				vm_phys_split_pages(m, oind, fl, order);
857 				return (m);
858 			}
859 		}
860 	}
861 	return (NULL);
862 }
863 
864 /*
865  * Find the vm_page corresponding to the given physical address.
866  */
867 vm_page_t
868 vm_phys_paddr_to_vm_page(vm_paddr_t pa)
869 {
870 	struct vm_phys_seg *seg;
871 	int segind;
872 
873 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
874 		seg = &vm_phys_segs[segind];
875 		if (pa >= seg->start && pa < seg->end)
876 			return (&seg->first_page[atop(pa - seg->start)]);
877 	}
878 	return (NULL);
879 }
880 
881 vm_page_t
882 vm_phys_fictitious_to_vm_page(vm_paddr_t pa)
883 {
884 	struct vm_phys_fictitious_seg tmp, *seg;
885 	vm_page_t m;
886 
887 	m = NULL;
888 	tmp.start = pa;
889 	tmp.end = 0;
890 
891 	rw_rlock(&vm_phys_fictitious_reg_lock);
892 	seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
893 	rw_runlock(&vm_phys_fictitious_reg_lock);
894 	if (seg == NULL)
895 		return (NULL);
896 
897 	m = &seg->first_page[atop(pa - seg->start)];
898 	KASSERT((m->flags & PG_FICTITIOUS) != 0, ("%p not fictitious", m));
899 
900 	return (m);
901 }
902 
903 static inline void
904 vm_phys_fictitious_init_range(vm_page_t range, vm_paddr_t start,
905     long page_count, vm_memattr_t memattr)
906 {
907 	long i;
908 
909 	bzero(range, page_count * sizeof(*range));
910 	for (i = 0; i < page_count; i++) {
911 		vm_page_initfake(&range[i], start + PAGE_SIZE * i, memattr);
912 		range[i].oflags &= ~VPO_UNMANAGED;
913 		range[i].busy_lock = VPB_UNBUSIED;
914 	}
915 }
916 
917 int
918 vm_phys_fictitious_reg_range(vm_paddr_t start, vm_paddr_t end,
919     vm_memattr_t memattr)
920 {
921 	struct vm_phys_fictitious_seg *seg;
922 	vm_page_t fp;
923 	long page_count;
924 #ifdef VM_PHYSSEG_DENSE
925 	long pi, pe;
926 	long dpage_count;
927 #endif
928 
929 	KASSERT(start < end,
930 	    ("Start of segment isn't less than end (start: %jx end: %jx)",
931 	    (uintmax_t)start, (uintmax_t)end));
932 
933 	page_count = (end - start) / PAGE_SIZE;
934 
935 #ifdef VM_PHYSSEG_DENSE
936 	pi = atop(start);
937 	pe = atop(end);
938 	if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
939 		fp = &vm_page_array[pi - first_page];
940 		if ((pe - first_page) > vm_page_array_size) {
941 			/*
942 			 * We have a segment that starts inside
943 			 * of vm_page_array, but ends outside of it.
944 			 *
945 			 * Use vm_page_array pages for those that are
946 			 * inside of the vm_page_array range, and
947 			 * allocate the remaining ones.
948 			 */
949 			dpage_count = vm_page_array_size - (pi - first_page);
950 			vm_phys_fictitious_init_range(fp, start, dpage_count,
951 			    memattr);
952 			page_count -= dpage_count;
953 			start += ptoa(dpage_count);
954 			goto alloc;
955 		}
956 		/*
957 		 * We can allocate the full range from vm_page_array,
958 		 * so there's no need to register the range in the tree.
959 		 */
960 		vm_phys_fictitious_init_range(fp, start, page_count, memattr);
961 		return (0);
962 	} else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
963 		/*
964 		 * We have a segment that ends inside of vm_page_array,
965 		 * but starts outside of it.
966 		 */
967 		fp = &vm_page_array[0];
968 		dpage_count = pe - first_page;
969 		vm_phys_fictitious_init_range(fp, ptoa(first_page), dpage_count,
970 		    memattr);
971 		end -= ptoa(dpage_count);
972 		page_count -= dpage_count;
973 		goto alloc;
974 	} else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
975 		/*
976 		 * Trying to register a fictitious range that expands before
977 		 * and after vm_page_array.
978 		 */
979 		return (EINVAL);
980 	} else {
981 alloc:
982 #endif
983 		fp = malloc(page_count * sizeof(struct vm_page), M_FICT_PAGES,
984 		    M_WAITOK);
985 #ifdef VM_PHYSSEG_DENSE
986 	}
987 #endif
988 	vm_phys_fictitious_init_range(fp, start, page_count, memattr);
989 
990 	seg = malloc(sizeof(*seg), M_FICT_PAGES, M_WAITOK | M_ZERO);
991 	seg->start = start;
992 	seg->end = end;
993 	seg->first_page = fp;
994 
995 	rw_wlock(&vm_phys_fictitious_reg_lock);
996 	RB_INSERT(fict_tree, &vm_phys_fictitious_tree, seg);
997 	rw_wunlock(&vm_phys_fictitious_reg_lock);
998 
999 	return (0);
1000 }
1001 
1002 void
1003 vm_phys_fictitious_unreg_range(vm_paddr_t start, vm_paddr_t end)
1004 {
1005 	struct vm_phys_fictitious_seg *seg, tmp;
1006 #ifdef VM_PHYSSEG_DENSE
1007 	long pi, pe;
1008 #endif
1009 
1010 	KASSERT(start < end,
1011 	    ("Start of segment isn't less than end (start: %jx end: %jx)",
1012 	    (uintmax_t)start, (uintmax_t)end));
1013 
1014 #ifdef VM_PHYSSEG_DENSE
1015 	pi = atop(start);
1016 	pe = atop(end);
1017 	if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
1018 		if ((pe - first_page) <= vm_page_array_size) {
1019 			/*
1020 			 * This segment was allocated using vm_page_array
1021 			 * only, there's nothing to do since those pages
1022 			 * were never added to the tree.
1023 			 */
1024 			return;
1025 		}
1026 		/*
1027 		 * We have a segment that starts inside
1028 		 * of vm_page_array, but ends outside of it.
1029 		 *
1030 		 * Calculate how many pages were added to the
1031 		 * tree and free them.
1032 		 */
1033 		start = ptoa(first_page + vm_page_array_size);
1034 	} else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
1035 		/*
1036 		 * We have a segment that ends inside of vm_page_array,
1037 		 * but starts outside of it.
1038 		 */
1039 		end = ptoa(first_page);
1040 	} else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
1041 		/* Since it's not possible to register such a range, panic. */
1042 		panic(
1043 		    "Unregistering not registered fictitious range [%#jx:%#jx]",
1044 		    (uintmax_t)start, (uintmax_t)end);
1045 	}
1046 #endif
1047 	tmp.start = start;
1048 	tmp.end = 0;
1049 
1050 	rw_wlock(&vm_phys_fictitious_reg_lock);
1051 	seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
1052 	if (seg->start != start || seg->end != end) {
1053 		rw_wunlock(&vm_phys_fictitious_reg_lock);
1054 		panic(
1055 		    "Unregistering not registered fictitious range [%#jx:%#jx]",
1056 		    (uintmax_t)start, (uintmax_t)end);
1057 	}
1058 	RB_REMOVE(fict_tree, &vm_phys_fictitious_tree, seg);
1059 	rw_wunlock(&vm_phys_fictitious_reg_lock);
1060 	free(seg->first_page, M_FICT_PAGES);
1061 	free(seg, M_FICT_PAGES);
1062 }
1063 
1064 /*
1065  * Find the segment containing the given physical address.
1066  */
1067 static int
1068 vm_phys_paddr_to_segind(vm_paddr_t pa)
1069 {
1070 	struct vm_phys_seg *seg;
1071 	int segind;
1072 
1073 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
1074 		seg = &vm_phys_segs[segind];
1075 		if (pa >= seg->start && pa < seg->end)
1076 			return (segind);
1077 	}
1078 	panic("vm_phys_paddr_to_segind: paddr %#jx is not in any segment" ,
1079 	    (uintmax_t)pa);
1080 }
1081 
1082 /*
1083  * Free a contiguous, power of two-sized set of physical pages.
1084  *
1085  * The free page queues must be locked.
1086  */
1087 void
1088 vm_phys_free_pages(vm_page_t m, int order)
1089 {
1090 	struct vm_freelist *fl;
1091 	struct vm_phys_seg *seg;
1092 	vm_paddr_t pa;
1093 	vm_page_t m_buddy;
1094 
1095 	KASSERT(m->order == VM_NFREEORDER,
1096 	    ("vm_phys_free_pages: page %p has unexpected order %d",
1097 	    m, m->order));
1098 	KASSERT(m->pool < VM_NFREEPOOL,
1099 	    ("vm_phys_free_pages: page %p has unexpected pool %d",
1100 	    m, m->pool));
1101 	KASSERT(order < VM_NFREEORDER,
1102 	    ("vm_phys_free_pages: order %d is out of range", order));
1103 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1104 	seg = &vm_phys_segs[m->segind];
1105 	if (order < VM_NFREEORDER - 1) {
1106 		pa = VM_PAGE_TO_PHYS(m);
1107 		do {
1108 			pa ^= ((vm_paddr_t)1 << (PAGE_SHIFT + order));
1109 			if (pa < seg->start || pa >= seg->end)
1110 				break;
1111 			m_buddy = &seg->first_page[atop(pa - seg->start)];
1112 			if (m_buddy->order != order)
1113 				break;
1114 			fl = (*seg->free_queues)[m_buddy->pool];
1115 			vm_freelist_rem(fl, m_buddy, order);
1116 			if (m_buddy->pool != m->pool)
1117 				vm_phys_set_pool(m->pool, m_buddy, order);
1118 			order++;
1119 			pa &= ~(((vm_paddr_t)1 << (PAGE_SHIFT + order)) - 1);
1120 			m = &seg->first_page[atop(pa - seg->start)];
1121 		} while (order < VM_NFREEORDER - 1);
1122 	}
1123 	fl = (*seg->free_queues)[m->pool];
1124 	vm_freelist_add(fl, m, order, 1);
1125 }
1126 
1127 /*
1128  * Free a contiguous, arbitrarily sized set of physical pages.
1129  *
1130  * The free page queues must be locked.
1131  */
1132 void
1133 vm_phys_free_contig(vm_page_t m, u_long npages)
1134 {
1135 	u_int n;
1136 	int order;
1137 
1138 	/*
1139 	 * Avoid unnecessary coalescing by freeing the pages in the largest
1140 	 * possible power-of-two-sized subsets.
1141 	 */
1142 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1143 	for (;; npages -= n) {
1144 		/*
1145 		 * Unsigned "min" is used here so that "order" is assigned
1146 		 * "VM_NFREEORDER - 1" when "m"'s physical address is zero
1147 		 * or the low-order bits of its physical address are zero
1148 		 * because the size of a physical address exceeds the size of
1149 		 * a long.
1150 		 */
1151 		order = min(ffsl(VM_PAGE_TO_PHYS(m) >> PAGE_SHIFT) - 1,
1152 		    VM_NFREEORDER - 1);
1153 		n = 1 << order;
1154 		if (npages < n)
1155 			break;
1156 		vm_phys_free_pages(m, order);
1157 		m += n;
1158 	}
1159 	/* The residual "npages" is less than "1 << (VM_NFREEORDER - 1)". */
1160 	for (; npages > 0; npages -= n) {
1161 		order = flsl(npages) - 1;
1162 		n = 1 << order;
1163 		vm_phys_free_pages(m, order);
1164 		m += n;
1165 	}
1166 }
1167 
1168 /*
1169  * Scan physical memory between the specified addresses "low" and "high" for a
1170  * run of contiguous physical pages that satisfy the specified conditions, and
1171  * return the lowest page in the run.  The specified "alignment" determines
1172  * the alignment of the lowest physical page in the run.  If the specified
1173  * "boundary" is non-zero, then the run of physical pages cannot span a
1174  * physical address that is a multiple of "boundary".
1175  *
1176  * "npages" must be greater than zero.  Both "alignment" and "boundary" must
1177  * be a power of two.
1178  */
1179 vm_page_t
1180 vm_phys_scan_contig(u_long npages, vm_paddr_t low, vm_paddr_t high,
1181     u_long alignment, vm_paddr_t boundary, int options)
1182 {
1183 	vm_paddr_t pa_end;
1184 	vm_page_t m_end, m_run, m_start;
1185 	struct vm_phys_seg *seg;
1186 	int segind;
1187 
1188 	KASSERT(npages > 0, ("npages is 0"));
1189 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1190 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1191 	if (low >= high)
1192 		return (NULL);
1193 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
1194 		seg = &vm_phys_segs[segind];
1195 		if (seg->start >= high)
1196 			break;
1197 		if (low >= seg->end)
1198 			continue;
1199 		if (low <= seg->start)
1200 			m_start = seg->first_page;
1201 		else
1202 			m_start = &seg->first_page[atop(low - seg->start)];
1203 		if (high < seg->end)
1204 			pa_end = high;
1205 		else
1206 			pa_end = seg->end;
1207 		if (pa_end - VM_PAGE_TO_PHYS(m_start) < ptoa(npages))
1208 			continue;
1209 		m_end = &seg->first_page[atop(pa_end - seg->start)];
1210 		m_run = vm_page_scan_contig(npages, m_start, m_end,
1211 		    alignment, boundary, options);
1212 		if (m_run != NULL)
1213 			return (m_run);
1214 	}
1215 	return (NULL);
1216 }
1217 
1218 /*
1219  * Set the pool for a contiguous, power of two-sized set of physical pages.
1220  */
1221 void
1222 vm_phys_set_pool(int pool, vm_page_t m, int order)
1223 {
1224 	vm_page_t m_tmp;
1225 
1226 	for (m_tmp = m; m_tmp < &m[1 << order]; m_tmp++)
1227 		m_tmp->pool = pool;
1228 }
1229 
1230 /*
1231  * Search for the given physical page "m" in the free lists.  If the search
1232  * succeeds, remove "m" from the free lists and return TRUE.  Otherwise, return
1233  * FALSE, indicating that "m" is not in the free lists.
1234  *
1235  * The free page queues must be locked.
1236  */
1237 boolean_t
1238 vm_phys_unfree_page(vm_page_t m)
1239 {
1240 	struct vm_freelist *fl;
1241 	struct vm_phys_seg *seg;
1242 	vm_paddr_t pa, pa_half;
1243 	vm_page_t m_set, m_tmp;
1244 	int order;
1245 
1246 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1247 
1248 	/*
1249 	 * First, find the contiguous, power of two-sized set of free
1250 	 * physical pages containing the given physical page "m" and
1251 	 * assign it to "m_set".
1252 	 */
1253 	seg = &vm_phys_segs[m->segind];
1254 	for (m_set = m, order = 0; m_set->order == VM_NFREEORDER &&
1255 	    order < VM_NFREEORDER - 1; ) {
1256 		order++;
1257 		pa = m->phys_addr & (~(vm_paddr_t)0 << (PAGE_SHIFT + order));
1258 		if (pa >= seg->start)
1259 			m_set = &seg->first_page[atop(pa - seg->start)];
1260 		else
1261 			return (FALSE);
1262 	}
1263 	if (m_set->order < order)
1264 		return (FALSE);
1265 	if (m_set->order == VM_NFREEORDER)
1266 		return (FALSE);
1267 	KASSERT(m_set->order < VM_NFREEORDER,
1268 	    ("vm_phys_unfree_page: page %p has unexpected order %d",
1269 	    m_set, m_set->order));
1270 
1271 	/*
1272 	 * Next, remove "m_set" from the free lists.  Finally, extract
1273 	 * "m" from "m_set" using an iterative algorithm: While "m_set"
1274 	 * is larger than a page, shrink "m_set" by returning the half
1275 	 * of "m_set" that does not contain "m" to the free lists.
1276 	 */
1277 	fl = (*seg->free_queues)[m_set->pool];
1278 	order = m_set->order;
1279 	vm_freelist_rem(fl, m_set, order);
1280 	while (order > 0) {
1281 		order--;
1282 		pa_half = m_set->phys_addr ^ (1 << (PAGE_SHIFT + order));
1283 		if (m->phys_addr < pa_half)
1284 			m_tmp = &seg->first_page[atop(pa_half - seg->start)];
1285 		else {
1286 			m_tmp = m_set;
1287 			m_set = &seg->first_page[atop(pa_half - seg->start)];
1288 		}
1289 		vm_freelist_add(fl, m_tmp, order, 0);
1290 	}
1291 	KASSERT(m_set == m, ("vm_phys_unfree_page: fatal inconsistency"));
1292 	return (TRUE);
1293 }
1294 
1295 /*
1296  * Allocate a contiguous set of physical pages of the given size
1297  * "npages" from the free lists.  All of the physical pages must be at
1298  * or above the given physical address "low" and below the given
1299  * physical address "high".  The given value "alignment" determines the
1300  * alignment of the first physical page in the set.  If the given value
1301  * "boundary" is non-zero, then the set of physical pages cannot cross
1302  * any physical address boundary that is a multiple of that value.  Both
1303  * "alignment" and "boundary" must be a power of two.
1304  */
1305 vm_page_t
1306 vm_phys_alloc_contig(u_long npages, vm_paddr_t low, vm_paddr_t high,
1307     u_long alignment, vm_paddr_t boundary)
1308 {
1309 	vm_paddr_t pa_end, pa_start;
1310 	vm_page_t m_run;
1311 	struct vm_domain_iterator vi;
1312 	struct vm_phys_seg *seg;
1313 	int domain, segind;
1314 
1315 	KASSERT(npages > 0, ("npages is 0"));
1316 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1317 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1318 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1319 	if (low >= high)
1320 		return (NULL);
1321 	vm_policy_iterator_init(&vi);
1322 restartdom:
1323 	if (vm_domain_iterator_run(&vi, &domain) != 0) {
1324 		vm_policy_iterator_finish(&vi);
1325 		return (NULL);
1326 	}
1327 	m_run = NULL;
1328 	for (segind = vm_phys_nsegs - 1; segind >= 0; segind--) {
1329 		seg = &vm_phys_segs[segind];
1330 		if (seg->start >= high || seg->domain != domain)
1331 			continue;
1332 		if (low >= seg->end)
1333 			break;
1334 		if (low <= seg->start)
1335 			pa_start = seg->start;
1336 		else
1337 			pa_start = low;
1338 		if (high < seg->end)
1339 			pa_end = high;
1340 		else
1341 			pa_end = seg->end;
1342 		if (pa_end - pa_start < ptoa(npages))
1343 			continue;
1344 		m_run = vm_phys_alloc_seg_contig(seg, npages, low, high,
1345 		    alignment, boundary);
1346 		if (m_run != NULL)
1347 			break;
1348 	}
1349 	if (m_run == NULL && !vm_domain_iterator_isdone(&vi))
1350 		goto restartdom;
1351 	vm_policy_iterator_finish(&vi);
1352 	return (m_run);
1353 }
1354 
1355 /*
1356  * Allocate a run of contiguous physical pages from the free list for the
1357  * specified segment.
1358  */
1359 static vm_page_t
1360 vm_phys_alloc_seg_contig(struct vm_phys_seg *seg, u_long npages,
1361     vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
1362 {
1363 	struct vm_freelist *fl;
1364 	vm_paddr_t pa, pa_end, size;
1365 	vm_page_t m, m_ret;
1366 	u_long npages_end;
1367 	int oind, order, pind;
1368 
1369 	KASSERT(npages > 0, ("npages is 0"));
1370 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1371 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1372 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1373 	/* Compute the queue that is the best fit for npages. */
1374 	for (order = 0; (1 << order) < npages; order++);
1375 	/* Search for a run satisfying the specified conditions. */
1376 	size = npages << PAGE_SHIFT;
1377 	for (oind = min(order, VM_NFREEORDER - 1); oind < VM_NFREEORDER;
1378 	    oind++) {
1379 		for (pind = 0; pind < VM_NFREEPOOL; pind++) {
1380 			fl = (*seg->free_queues)[pind];
1381 			TAILQ_FOREACH(m_ret, &fl[oind].pl, plinks.q) {
1382 				/*
1383 				 * Is the size of this allocation request
1384 				 * larger than the largest block size?
1385 				 */
1386 				if (order >= VM_NFREEORDER) {
1387 					/*
1388 					 * Determine if a sufficient number of
1389 					 * subsequent blocks to satisfy the
1390 					 * allocation request are free.
1391 					 */
1392 					pa = VM_PAGE_TO_PHYS(m_ret);
1393 					pa_end = pa + size;
1394 					for (;;) {
1395 						pa += 1 << (PAGE_SHIFT +
1396 						    VM_NFREEORDER - 1);
1397 						if (pa >= pa_end ||
1398 						    pa < seg->start ||
1399 						    pa >= seg->end)
1400 							break;
1401 						m = &seg->first_page[atop(pa -
1402 						    seg->start)];
1403 						if (m->order != VM_NFREEORDER -
1404 						    1)
1405 							break;
1406 					}
1407 					/* If not, go to the next block. */
1408 					if (pa < pa_end)
1409 						continue;
1410 				}
1411 
1412 				/*
1413 				 * Determine if the blocks are within the
1414 				 * given range, satisfy the given alignment,
1415 				 * and do not cross the given boundary.
1416 				 */
1417 				pa = VM_PAGE_TO_PHYS(m_ret);
1418 				pa_end = pa + size;
1419 				if (pa >= low && pa_end <= high &&
1420 				    (pa & (alignment - 1)) == 0 &&
1421 				    rounddown2(pa ^ (pa_end - 1), boundary) == 0)
1422 					goto done;
1423 			}
1424 		}
1425 	}
1426 	return (NULL);
1427 done:
1428 	for (m = m_ret; m < &m_ret[npages]; m = &m[1 << oind]) {
1429 		fl = (*seg->free_queues)[m->pool];
1430 		vm_freelist_rem(fl, m, m->order);
1431 	}
1432 	if (m_ret->pool != VM_FREEPOOL_DEFAULT)
1433 		vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m_ret, oind);
1434 	fl = (*seg->free_queues)[m_ret->pool];
1435 	vm_phys_split_pages(m_ret, oind, fl, order);
1436 	/* Return excess pages to the free lists. */
1437 	npages_end = roundup2(npages, 1 << imin(oind, order));
1438 	if (npages < npages_end)
1439 		vm_phys_free_contig(&m_ret[npages], npages_end - npages);
1440 	return (m_ret);
1441 }
1442 
1443 #ifdef DDB
1444 /*
1445  * Show the number of physical pages in each of the free lists.
1446  */
1447 DB_SHOW_COMMAND(freepages, db_show_freepages)
1448 {
1449 	struct vm_freelist *fl;
1450 	int flind, oind, pind, dom;
1451 
1452 	for (dom = 0; dom < vm_ndomains; dom++) {
1453 		db_printf("DOMAIN: %d\n", dom);
1454 		for (flind = 0; flind < vm_nfreelists; flind++) {
1455 			db_printf("FREE LIST %d:\n"
1456 			    "\n  ORDER (SIZE)  |  NUMBER"
1457 			    "\n              ", flind);
1458 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
1459 				db_printf("  |  POOL %d", pind);
1460 			db_printf("\n--            ");
1461 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
1462 				db_printf("-- --      ");
1463 			db_printf("--\n");
1464 			for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
1465 				db_printf("  %2.2d (%6.6dK)", oind,
1466 				    1 << (PAGE_SHIFT - 10 + oind));
1467 				for (pind = 0; pind < VM_NFREEPOOL; pind++) {
1468 				fl = vm_phys_free_queues[dom][flind][pind];
1469 					db_printf("  |  %6.6d", fl[oind].lcnt);
1470 				}
1471 				db_printf("\n");
1472 			}
1473 			db_printf("\n");
1474 		}
1475 		db_printf("\n");
1476 	}
1477 }
1478 #endif
1479