xref: /freebsd/sys/vm/vm_phys.c (revision 62d70a8174c9a78bf0caf7a405b5e7c670e28360)
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 cnt_prezero;
136 SYSCTL_INT(_vm_stats_misc, OID_AUTO, cnt_prezero, CTLFLAG_RD,
137     &cnt_prezero, 0, "The number of physical pages prezeroed at idle time");
138 
139 static int sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS);
140 SYSCTL_OID(_vm, OID_AUTO, phys_free, CTLTYPE_STRING | CTLFLAG_RD,
141     NULL, 0, sysctl_vm_phys_free, "A", "Phys Free Info");
142 
143 static int sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS);
144 SYSCTL_OID(_vm, OID_AUTO, phys_segs, CTLTYPE_STRING | CTLFLAG_RD,
145     NULL, 0, sysctl_vm_phys_segs, "A", "Phys Seg Info");
146 
147 #ifdef VM_NUMA_ALLOC
148 static int sysctl_vm_phys_locality(SYSCTL_HANDLER_ARGS);
149 SYSCTL_OID(_vm, OID_AUTO, phys_locality, CTLTYPE_STRING | CTLFLAG_RD,
150     NULL, 0, sysctl_vm_phys_locality, "A", "Phys Locality Info");
151 #endif
152 
153 SYSCTL_INT(_vm, OID_AUTO, ndomains, CTLFLAG_RD,
154     &vm_ndomains, 0, "Number of physical memory domains available.");
155 
156 /*
157  * Default to first-touch + round-robin.
158  */
159 static struct mtx vm_default_policy_mtx;
160 MTX_SYSINIT(vm_default_policy, &vm_default_policy_mtx, "default policy mutex",
161     MTX_DEF);
162 #ifdef VM_NUMA_ALLOC
163 static struct vm_domain_policy vm_default_policy =
164     VM_DOMAIN_POLICY_STATIC_INITIALISER(VM_POLICY_FIRST_TOUCH_ROUND_ROBIN, 0);
165 #else
166 /* Use round-robin so the domain policy code will only try once per allocation */
167 static struct vm_domain_policy vm_default_policy =
168     VM_DOMAIN_POLICY_STATIC_INITIALISER(VM_POLICY_ROUND_ROBIN, 0);
169 #endif
170 
171 static vm_page_t vm_phys_alloc_domain_pages(int domain, int flind, int pool,
172     int order);
173 static vm_page_t vm_phys_alloc_seg_contig(struct vm_phys_seg *seg,
174     u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
175     vm_paddr_t boundary);
176 static void _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int domain);
177 static void vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end);
178 static int vm_phys_paddr_to_segind(vm_paddr_t pa);
179 static void vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl,
180     int order);
181 
182 static int
183 sysctl_vm_default_policy(SYSCTL_HANDLER_ARGS)
184 {
185 	char policy_name[32];
186 	int error;
187 
188 	mtx_lock(&vm_default_policy_mtx);
189 
190 	/* Map policy to output string */
191 	switch (vm_default_policy.p.policy) {
192 	case VM_POLICY_FIRST_TOUCH:
193 		strcpy(policy_name, "first-touch");
194 		break;
195 	case VM_POLICY_FIRST_TOUCH_ROUND_ROBIN:
196 		strcpy(policy_name, "first-touch-rr");
197 		break;
198 	case VM_POLICY_ROUND_ROBIN:
199 	default:
200 		strcpy(policy_name, "rr");
201 		break;
202 	}
203 	mtx_unlock(&vm_default_policy_mtx);
204 
205 	error = sysctl_handle_string(oidp, &policy_name[0],
206 	    sizeof(policy_name), req);
207 	if (error != 0 || req->newptr == NULL)
208 		return (error);
209 
210 	mtx_lock(&vm_default_policy_mtx);
211 	/* Set: match on the subset of policies that make sense as a default */
212 	if (strcmp("first-touch-rr", policy_name) == 0) {
213 		vm_domain_policy_set(&vm_default_policy,
214 		    VM_POLICY_FIRST_TOUCH_ROUND_ROBIN, 0);
215 	} else if (strcmp("first-touch", policy_name) == 0) {
216 		vm_domain_policy_set(&vm_default_policy,
217 		    VM_POLICY_FIRST_TOUCH, 0);
218 	} else if (strcmp("rr", policy_name) == 0) {
219 		vm_domain_policy_set(&vm_default_policy,
220 		    VM_POLICY_ROUND_ROBIN, 0);
221 	} else {
222 		error = EINVAL;
223 		goto finish;
224 	}
225 
226 	error = 0;
227 finish:
228 	mtx_unlock(&vm_default_policy_mtx);
229 	return (error);
230 }
231 
232 SYSCTL_PROC(_vm, OID_AUTO, default_policy, CTLTYPE_STRING | CTLFLAG_RW,
233     0, 0, sysctl_vm_default_policy, "A",
234     "Default policy (rr, first-touch, first-touch-rr");
235 
236 /*
237  * Red-black tree helpers for vm fictitious range management.
238  */
239 static inline int
240 vm_phys_fictitious_in_range(struct vm_phys_fictitious_seg *p,
241     struct vm_phys_fictitious_seg *range)
242 {
243 
244 	KASSERT(range->start != 0 && range->end != 0,
245 	    ("Invalid range passed on search for vm_fictitious page"));
246 	if (p->start >= range->end)
247 		return (1);
248 	if (p->start < range->start)
249 		return (-1);
250 
251 	return (0);
252 }
253 
254 static int
255 vm_phys_fictitious_cmp(struct vm_phys_fictitious_seg *p1,
256     struct vm_phys_fictitious_seg *p2)
257 {
258 
259 	/* Check if this is a search for a page */
260 	if (p1->end == 0)
261 		return (vm_phys_fictitious_in_range(p1, p2));
262 
263 	KASSERT(p2->end != 0,
264     ("Invalid range passed as second parameter to vm fictitious comparison"));
265 
266 	/* Searching to add a new range */
267 	if (p1->end <= p2->start)
268 		return (-1);
269 	if (p1->start >= p2->end)
270 		return (1);
271 
272 	panic("Trying to add overlapping vm fictitious ranges:\n"
273 	    "[%#jx:%#jx] and [%#jx:%#jx]", (uintmax_t)p1->start,
274 	    (uintmax_t)p1->end, (uintmax_t)p2->start, (uintmax_t)p2->end);
275 }
276 
277 static __inline int
278 vm_rr_selectdomain(void)
279 {
280 #ifdef VM_NUMA_ALLOC
281 	struct thread *td;
282 
283 	td = curthread;
284 
285 	td->td_dom_rr_idx++;
286 	td->td_dom_rr_idx %= vm_ndomains;
287 	return (td->td_dom_rr_idx);
288 #else
289 	return (0);
290 #endif
291 }
292 
293 /*
294  * Initialise a VM domain iterator.
295  *
296  * Check the thread policy, then the proc policy,
297  * then default to the system policy.
298  *
299  * Later on the various layers will have this logic
300  * plumbed into them and the phys code will be explicitly
301  * handed a VM domain policy to use.
302  */
303 static void
304 vm_policy_iterator_init(struct vm_domain_iterator *vi)
305 {
306 #ifdef VM_NUMA_ALLOC
307 	struct vm_domain_policy lcl;
308 #endif
309 
310 	vm_domain_iterator_init(vi);
311 
312 #ifdef VM_NUMA_ALLOC
313 	/* Copy out the thread policy */
314 	vm_domain_policy_localcopy(&lcl, &curthread->td_vm_dom_policy);
315 	if (lcl.p.policy != VM_POLICY_NONE) {
316 		/* Thread policy is present; use it */
317 		vm_domain_iterator_set_policy(vi, &lcl);
318 		return;
319 	}
320 
321 	vm_domain_policy_localcopy(&lcl,
322 	    &curthread->td_proc->p_vm_dom_policy);
323 	if (lcl.p.policy != VM_POLICY_NONE) {
324 		/* Process policy is present; use it */
325 		vm_domain_iterator_set_policy(vi, &lcl);
326 		return;
327 	}
328 #endif
329 	/* Use system default policy */
330 	vm_domain_iterator_set_policy(vi, &vm_default_policy);
331 }
332 
333 static void
334 vm_policy_iterator_finish(struct vm_domain_iterator *vi)
335 {
336 
337 	vm_domain_iterator_cleanup(vi);
338 }
339 
340 boolean_t
341 vm_phys_domain_intersects(long mask, vm_paddr_t low, vm_paddr_t high)
342 {
343 	struct vm_phys_seg *s;
344 	int idx;
345 
346 	while ((idx = ffsl(mask)) != 0) {
347 		idx--;	/* ffsl counts from 1 */
348 		mask &= ~(1UL << idx);
349 		s = &vm_phys_segs[idx];
350 		if (low < s->end && high > s->start)
351 			return (TRUE);
352 	}
353 	return (FALSE);
354 }
355 
356 /*
357  * Outputs the state of the physical memory allocator, specifically,
358  * the amount of physical memory in each free list.
359  */
360 static int
361 sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS)
362 {
363 	struct sbuf sbuf;
364 	struct vm_freelist *fl;
365 	int dom, error, flind, oind, pind;
366 
367 	error = sysctl_wire_old_buffer(req, 0);
368 	if (error != 0)
369 		return (error);
370 	sbuf_new_for_sysctl(&sbuf, NULL, 128 * vm_ndomains, req);
371 	for (dom = 0; dom < vm_ndomains; dom++) {
372 		sbuf_printf(&sbuf,"\nDOMAIN %d:\n", dom);
373 		for (flind = 0; flind < vm_nfreelists; flind++) {
374 			sbuf_printf(&sbuf, "\nFREE LIST %d:\n"
375 			    "\n  ORDER (SIZE)  |  NUMBER"
376 			    "\n              ", flind);
377 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
378 				sbuf_printf(&sbuf, "  |  POOL %d", pind);
379 			sbuf_printf(&sbuf, "\n--            ");
380 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
381 				sbuf_printf(&sbuf, "-- --      ");
382 			sbuf_printf(&sbuf, "--\n");
383 			for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
384 				sbuf_printf(&sbuf, "  %2d (%6dK)", oind,
385 				    1 << (PAGE_SHIFT - 10 + oind));
386 				for (pind = 0; pind < VM_NFREEPOOL; pind++) {
387 				fl = vm_phys_free_queues[dom][flind][pind];
388 					sbuf_printf(&sbuf, "  |  %6d",
389 					    fl[oind].lcnt);
390 				}
391 				sbuf_printf(&sbuf, "\n");
392 			}
393 		}
394 	}
395 	error = sbuf_finish(&sbuf);
396 	sbuf_delete(&sbuf);
397 	return (error);
398 }
399 
400 /*
401  * Outputs the set of physical memory segments.
402  */
403 static int
404 sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS)
405 {
406 	struct sbuf sbuf;
407 	struct vm_phys_seg *seg;
408 	int error, segind;
409 
410 	error = sysctl_wire_old_buffer(req, 0);
411 	if (error != 0)
412 		return (error);
413 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
414 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
415 		sbuf_printf(&sbuf, "\nSEGMENT %d:\n\n", segind);
416 		seg = &vm_phys_segs[segind];
417 		sbuf_printf(&sbuf, "start:     %#jx\n",
418 		    (uintmax_t)seg->start);
419 		sbuf_printf(&sbuf, "end:       %#jx\n",
420 		    (uintmax_t)seg->end);
421 		sbuf_printf(&sbuf, "domain:    %d\n", seg->domain);
422 		sbuf_printf(&sbuf, "free list: %p\n", seg->free_queues);
423 	}
424 	error = sbuf_finish(&sbuf);
425 	sbuf_delete(&sbuf);
426 	return (error);
427 }
428 
429 /*
430  * Return affinity, or -1 if there's no affinity information.
431  */
432 int
433 vm_phys_mem_affinity(int f, int t)
434 {
435 
436 #ifdef VM_NUMA_ALLOC
437 	if (mem_locality == NULL)
438 		return (-1);
439 	if (f >= vm_ndomains || t >= vm_ndomains)
440 		return (-1);
441 	return (mem_locality[f * vm_ndomains + t]);
442 #else
443 	return (-1);
444 #endif
445 }
446 
447 #ifdef VM_NUMA_ALLOC
448 /*
449  * Outputs the VM locality table.
450  */
451 static int
452 sysctl_vm_phys_locality(SYSCTL_HANDLER_ARGS)
453 {
454 	struct sbuf sbuf;
455 	int error, i, j;
456 
457 	error = sysctl_wire_old_buffer(req, 0);
458 	if (error != 0)
459 		return (error);
460 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
461 
462 	sbuf_printf(&sbuf, "\n");
463 
464 	for (i = 0; i < vm_ndomains; i++) {
465 		sbuf_printf(&sbuf, "%d: ", i);
466 		for (j = 0; j < vm_ndomains; j++) {
467 			sbuf_printf(&sbuf, "%d ", vm_phys_mem_affinity(i, j));
468 		}
469 		sbuf_printf(&sbuf, "\n");
470 	}
471 	error = sbuf_finish(&sbuf);
472 	sbuf_delete(&sbuf);
473 	return (error);
474 }
475 #endif
476 
477 static void
478 vm_freelist_add(struct vm_freelist *fl, vm_page_t m, int order, int tail)
479 {
480 
481 	m->order = order;
482 	if (tail)
483 		TAILQ_INSERT_TAIL(&fl[order].pl, m, plinks.q);
484 	else
485 		TAILQ_INSERT_HEAD(&fl[order].pl, m, plinks.q);
486 	fl[order].lcnt++;
487 }
488 
489 static void
490 vm_freelist_rem(struct vm_freelist *fl, vm_page_t m, int order)
491 {
492 
493 	TAILQ_REMOVE(&fl[order].pl, m, plinks.q);
494 	fl[order].lcnt--;
495 	m->order = VM_NFREEORDER;
496 }
497 
498 /*
499  * Create a physical memory segment.
500  */
501 static void
502 _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int domain)
503 {
504 	struct vm_phys_seg *seg;
505 
506 	KASSERT(vm_phys_nsegs < VM_PHYSSEG_MAX,
507 	    ("vm_phys_create_seg: increase VM_PHYSSEG_MAX"));
508 	KASSERT(domain < vm_ndomains,
509 	    ("vm_phys_create_seg: invalid domain provided"));
510 	seg = &vm_phys_segs[vm_phys_nsegs++];
511 	while (seg > vm_phys_segs && (seg - 1)->start >= end) {
512 		*seg = *(seg - 1);
513 		seg--;
514 	}
515 	seg->start = start;
516 	seg->end = end;
517 	seg->domain = domain;
518 }
519 
520 static void
521 vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end)
522 {
523 #ifdef VM_NUMA_ALLOC
524 	int i;
525 
526 	if (mem_affinity == NULL) {
527 		_vm_phys_create_seg(start, end, 0);
528 		return;
529 	}
530 
531 	for (i = 0;; i++) {
532 		if (mem_affinity[i].end == 0)
533 			panic("Reached end of affinity info");
534 		if (mem_affinity[i].end <= start)
535 			continue;
536 		if (mem_affinity[i].start > start)
537 			panic("No affinity info for start %jx",
538 			    (uintmax_t)start);
539 		if (mem_affinity[i].end >= end) {
540 			_vm_phys_create_seg(start, end,
541 			    mem_affinity[i].domain);
542 			break;
543 		}
544 		_vm_phys_create_seg(start, mem_affinity[i].end,
545 		    mem_affinity[i].domain);
546 		start = mem_affinity[i].end;
547 	}
548 #else
549 	_vm_phys_create_seg(start, end, 0);
550 #endif
551 }
552 
553 /*
554  * Add a physical memory segment.
555  */
556 void
557 vm_phys_add_seg(vm_paddr_t start, vm_paddr_t end)
558 {
559 	vm_paddr_t paddr;
560 
561 	KASSERT((start & PAGE_MASK) == 0,
562 	    ("vm_phys_define_seg: start is not page aligned"));
563 	KASSERT((end & PAGE_MASK) == 0,
564 	    ("vm_phys_define_seg: end is not page aligned"));
565 
566 	/*
567 	 * Split the physical memory segment if it spans two or more free
568 	 * list boundaries.
569 	 */
570 	paddr = start;
571 #ifdef	VM_FREELIST_ISADMA
572 	if (paddr < VM_ISADMA_BOUNDARY && end > VM_ISADMA_BOUNDARY) {
573 		vm_phys_create_seg(paddr, VM_ISADMA_BOUNDARY);
574 		paddr = VM_ISADMA_BOUNDARY;
575 	}
576 #endif
577 #ifdef	VM_FREELIST_LOWMEM
578 	if (paddr < VM_LOWMEM_BOUNDARY && end > VM_LOWMEM_BOUNDARY) {
579 		vm_phys_create_seg(paddr, VM_LOWMEM_BOUNDARY);
580 		paddr = VM_LOWMEM_BOUNDARY;
581 	}
582 #endif
583 #ifdef	VM_FREELIST_DMA32
584 	if (paddr < VM_DMA32_BOUNDARY && end > VM_DMA32_BOUNDARY) {
585 		vm_phys_create_seg(paddr, VM_DMA32_BOUNDARY);
586 		paddr = VM_DMA32_BOUNDARY;
587 	}
588 #endif
589 	vm_phys_create_seg(paddr, end);
590 }
591 
592 /*
593  * Initialize the physical memory allocator.
594  *
595  * Requires that vm_page_array is initialized!
596  */
597 void
598 vm_phys_init(void)
599 {
600 	struct vm_freelist *fl;
601 	struct vm_phys_seg *seg;
602 	u_long npages;
603 	int dom, flind, freelist, oind, pind, segind;
604 
605 	/*
606 	 * Compute the number of free lists, and generate the mapping from the
607 	 * manifest constants VM_FREELIST_* to the free list indices.
608 	 *
609 	 * Initially, the entries of vm_freelist_to_flind[] are set to either
610 	 * 0 or 1 to indicate which free lists should be created.
611 	 */
612 	npages = 0;
613 	for (segind = vm_phys_nsegs - 1; segind >= 0; segind--) {
614 		seg = &vm_phys_segs[segind];
615 #ifdef	VM_FREELIST_ISADMA
616 		if (seg->end <= VM_ISADMA_BOUNDARY)
617 			vm_freelist_to_flind[VM_FREELIST_ISADMA] = 1;
618 		else
619 #endif
620 #ifdef	VM_FREELIST_LOWMEM
621 		if (seg->end <= VM_LOWMEM_BOUNDARY)
622 			vm_freelist_to_flind[VM_FREELIST_LOWMEM] = 1;
623 		else
624 #endif
625 #ifdef	VM_FREELIST_DMA32
626 		if (
627 #ifdef	VM_DMA32_NPAGES_THRESHOLD
628 		    /*
629 		     * Create the DMA32 free list only if the amount of
630 		     * physical memory above physical address 4G exceeds the
631 		     * given threshold.
632 		     */
633 		    npages > VM_DMA32_NPAGES_THRESHOLD &&
634 #endif
635 		    seg->end <= VM_DMA32_BOUNDARY)
636 			vm_freelist_to_flind[VM_FREELIST_DMA32] = 1;
637 		else
638 #endif
639 		{
640 			npages += atop(seg->end - seg->start);
641 			vm_freelist_to_flind[VM_FREELIST_DEFAULT] = 1;
642 		}
643 	}
644 	/* Change each entry into a running total of the free lists. */
645 	for (freelist = 1; freelist < VM_NFREELIST; freelist++) {
646 		vm_freelist_to_flind[freelist] +=
647 		    vm_freelist_to_flind[freelist - 1];
648 	}
649 	vm_nfreelists = vm_freelist_to_flind[VM_NFREELIST - 1];
650 	KASSERT(vm_nfreelists > 0, ("vm_phys_init: no free lists"));
651 	/* Change each entry into a free list index. */
652 	for (freelist = 0; freelist < VM_NFREELIST; freelist++)
653 		vm_freelist_to_flind[freelist]--;
654 
655 	/*
656 	 * Initialize the first_page and free_queues fields of each physical
657 	 * memory segment.
658 	 */
659 #ifdef VM_PHYSSEG_SPARSE
660 	npages = 0;
661 #endif
662 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
663 		seg = &vm_phys_segs[segind];
664 #ifdef VM_PHYSSEG_SPARSE
665 		seg->first_page = &vm_page_array[npages];
666 		npages += atop(seg->end - seg->start);
667 #else
668 		seg->first_page = PHYS_TO_VM_PAGE(seg->start);
669 #endif
670 #ifdef	VM_FREELIST_ISADMA
671 		if (seg->end <= VM_ISADMA_BOUNDARY) {
672 			flind = vm_freelist_to_flind[VM_FREELIST_ISADMA];
673 			KASSERT(flind >= 0,
674 			    ("vm_phys_init: ISADMA flind < 0"));
675 		} else
676 #endif
677 #ifdef	VM_FREELIST_LOWMEM
678 		if (seg->end <= VM_LOWMEM_BOUNDARY) {
679 			flind = vm_freelist_to_flind[VM_FREELIST_LOWMEM];
680 			KASSERT(flind >= 0,
681 			    ("vm_phys_init: LOWMEM flind < 0"));
682 		} else
683 #endif
684 #ifdef	VM_FREELIST_DMA32
685 		if (seg->end <= VM_DMA32_BOUNDARY) {
686 			flind = vm_freelist_to_flind[VM_FREELIST_DMA32];
687 			KASSERT(flind >= 0,
688 			    ("vm_phys_init: DMA32 flind < 0"));
689 		} else
690 #endif
691 		{
692 			flind = vm_freelist_to_flind[VM_FREELIST_DEFAULT];
693 			KASSERT(flind >= 0,
694 			    ("vm_phys_init: DEFAULT flind < 0"));
695 		}
696 		seg->free_queues = &vm_phys_free_queues[seg->domain][flind];
697 	}
698 
699 	/*
700 	 * Initialize the free queues.
701 	 */
702 	for (dom = 0; dom < vm_ndomains; dom++) {
703 		for (flind = 0; flind < vm_nfreelists; flind++) {
704 			for (pind = 0; pind < VM_NFREEPOOL; pind++) {
705 				fl = vm_phys_free_queues[dom][flind][pind];
706 				for (oind = 0; oind < VM_NFREEORDER; oind++)
707 					TAILQ_INIT(&fl[oind].pl);
708 			}
709 		}
710 	}
711 
712 	rw_init(&vm_phys_fictitious_reg_lock, "vmfctr");
713 }
714 
715 /*
716  * Split a contiguous, power of two-sized set of physical pages.
717  */
718 static __inline void
719 vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl, int order)
720 {
721 	vm_page_t m_buddy;
722 
723 	while (oind > order) {
724 		oind--;
725 		m_buddy = &m[1 << oind];
726 		KASSERT(m_buddy->order == VM_NFREEORDER,
727 		    ("vm_phys_split_pages: page %p has unexpected order %d",
728 		    m_buddy, m_buddy->order));
729 		vm_freelist_add(fl, m_buddy, oind, 0);
730         }
731 }
732 
733 /*
734  * Initialize a physical page and add it to the free lists.
735  */
736 void
737 vm_phys_add_page(vm_paddr_t pa)
738 {
739 	vm_page_t m;
740 	struct vm_domain *vmd;
741 
742 	vm_cnt.v_page_count++;
743 	m = vm_phys_paddr_to_vm_page(pa);
744 	m->phys_addr = pa;
745 	m->queue = PQ_NONE;
746 	m->segind = vm_phys_paddr_to_segind(pa);
747 	vmd = vm_phys_domain(m);
748 	vmd->vmd_page_count++;
749 	vmd->vmd_segs |= 1UL << m->segind;
750 	KASSERT(m->order == VM_NFREEORDER,
751 	    ("vm_phys_add_page: page %p has unexpected order %d",
752 	    m, m->order));
753 	m->pool = VM_FREEPOOL_DEFAULT;
754 	pmap_page_init(m);
755 	mtx_lock(&vm_page_queue_free_mtx);
756 	vm_phys_freecnt_adj(m, 1);
757 	vm_phys_free_pages(m, 0);
758 	mtx_unlock(&vm_page_queue_free_mtx);
759 }
760 
761 /*
762  * Allocate a contiguous, power of two-sized set of physical pages
763  * from the free lists.
764  *
765  * The free page queues must be locked.
766  */
767 vm_page_t
768 vm_phys_alloc_pages(int pool, int order)
769 {
770 	vm_page_t m;
771 	int domain, flind;
772 	struct vm_domain_iterator vi;
773 
774 	KASSERT(pool < VM_NFREEPOOL,
775 	    ("vm_phys_alloc_pages: pool %d is out of range", pool));
776 	KASSERT(order < VM_NFREEORDER,
777 	    ("vm_phys_alloc_pages: order %d is out of range", order));
778 
779 	vm_policy_iterator_init(&vi);
780 
781 	while ((vm_domain_iterator_run(&vi, &domain)) == 0) {
782 		for (flind = 0; flind < vm_nfreelists; flind++) {
783 			m = vm_phys_alloc_domain_pages(domain, flind, pool,
784 			    order);
785 			if (m != NULL)
786 				return (m);
787 		}
788 	}
789 
790 	vm_policy_iterator_finish(&vi);
791 	return (NULL);
792 }
793 
794 /*
795  * Allocate a contiguous, power of two-sized set of physical pages from the
796  * specified free list.  The free list must be specified using one of the
797  * manifest constants VM_FREELIST_*.
798  *
799  * The free page queues must be locked.
800  */
801 vm_page_t
802 vm_phys_alloc_freelist_pages(int freelist, int pool, int order)
803 {
804 	vm_page_t m;
805 	struct vm_domain_iterator vi;
806 	int domain;
807 
808 	KASSERT(freelist < VM_NFREELIST,
809 	    ("vm_phys_alloc_freelist_pages: freelist %d is out of range",
810 	    freelist));
811 	KASSERT(pool < VM_NFREEPOOL,
812 	    ("vm_phys_alloc_freelist_pages: pool %d is out of range", pool));
813 	KASSERT(order < VM_NFREEORDER,
814 	    ("vm_phys_alloc_freelist_pages: order %d is out of range", order));
815 
816 	vm_policy_iterator_init(&vi);
817 
818 	while ((vm_domain_iterator_run(&vi, &domain)) == 0) {
819 		m = vm_phys_alloc_domain_pages(domain,
820 		    vm_freelist_to_flind[freelist], pool, order);
821 		if (m != NULL)
822 			return (m);
823 	}
824 
825 	vm_policy_iterator_finish(&vi);
826 	return (NULL);
827 }
828 
829 static vm_page_t
830 vm_phys_alloc_domain_pages(int domain, int flind, int pool, int order)
831 {
832 	struct vm_freelist *fl;
833 	struct vm_freelist *alt;
834 	int oind, pind;
835 	vm_page_t m;
836 
837 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
838 	fl = &vm_phys_free_queues[domain][flind][pool][0];
839 	for (oind = order; oind < VM_NFREEORDER; oind++) {
840 		m = TAILQ_FIRST(&fl[oind].pl);
841 		if (m != NULL) {
842 			vm_freelist_rem(fl, m, oind);
843 			vm_phys_split_pages(m, oind, fl, order);
844 			return (m);
845 		}
846 	}
847 
848 	/*
849 	 * The given pool was empty.  Find the largest
850 	 * contiguous, power-of-two-sized set of pages in any
851 	 * pool.  Transfer these pages to the given pool, and
852 	 * use them to satisfy the allocation.
853 	 */
854 	for (oind = VM_NFREEORDER - 1; oind >= order; oind--) {
855 		for (pind = 0; pind < VM_NFREEPOOL; pind++) {
856 			alt = &vm_phys_free_queues[domain][flind][pind][0];
857 			m = TAILQ_FIRST(&alt[oind].pl);
858 			if (m != NULL) {
859 				vm_freelist_rem(alt, m, oind);
860 				vm_phys_set_pool(pool, m, oind);
861 				vm_phys_split_pages(m, oind, fl, order);
862 				return (m);
863 			}
864 		}
865 	}
866 	return (NULL);
867 }
868 
869 /*
870  * Find the vm_page corresponding to the given physical address.
871  */
872 vm_page_t
873 vm_phys_paddr_to_vm_page(vm_paddr_t pa)
874 {
875 	struct vm_phys_seg *seg;
876 	int segind;
877 
878 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
879 		seg = &vm_phys_segs[segind];
880 		if (pa >= seg->start && pa < seg->end)
881 			return (&seg->first_page[atop(pa - seg->start)]);
882 	}
883 	return (NULL);
884 }
885 
886 vm_page_t
887 vm_phys_fictitious_to_vm_page(vm_paddr_t pa)
888 {
889 	struct vm_phys_fictitious_seg tmp, *seg;
890 	vm_page_t m;
891 
892 	m = NULL;
893 	tmp.start = pa;
894 	tmp.end = 0;
895 
896 	rw_rlock(&vm_phys_fictitious_reg_lock);
897 	seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
898 	rw_runlock(&vm_phys_fictitious_reg_lock);
899 	if (seg == NULL)
900 		return (NULL);
901 
902 	m = &seg->first_page[atop(pa - seg->start)];
903 	KASSERT((m->flags & PG_FICTITIOUS) != 0, ("%p not fictitious", m));
904 
905 	return (m);
906 }
907 
908 static inline void
909 vm_phys_fictitious_init_range(vm_page_t range, vm_paddr_t start,
910     long page_count, vm_memattr_t memattr)
911 {
912 	long i;
913 
914 	for (i = 0; i < page_count; i++) {
915 		vm_page_initfake(&range[i], start + PAGE_SIZE * i, memattr);
916 		range[i].oflags &= ~VPO_UNMANAGED;
917 		range[i].busy_lock = VPB_UNBUSIED;
918 	}
919 }
920 
921 int
922 vm_phys_fictitious_reg_range(vm_paddr_t start, vm_paddr_t end,
923     vm_memattr_t memattr)
924 {
925 	struct vm_phys_fictitious_seg *seg;
926 	vm_page_t fp;
927 	long page_count;
928 #ifdef VM_PHYSSEG_DENSE
929 	long pi, pe;
930 	long dpage_count;
931 #endif
932 
933 	KASSERT(start < end,
934 	    ("Start of segment isn't less than end (start: %jx end: %jx)",
935 	    (uintmax_t)start, (uintmax_t)end));
936 
937 	page_count = (end - start) / PAGE_SIZE;
938 
939 #ifdef VM_PHYSSEG_DENSE
940 	pi = atop(start);
941 	pe = atop(end);
942 	if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
943 		fp = &vm_page_array[pi - first_page];
944 		if ((pe - first_page) > vm_page_array_size) {
945 			/*
946 			 * We have a segment that starts inside
947 			 * of vm_page_array, but ends outside of it.
948 			 *
949 			 * Use vm_page_array pages for those that are
950 			 * inside of the vm_page_array range, and
951 			 * allocate the remaining ones.
952 			 */
953 			dpage_count = vm_page_array_size - (pi - first_page);
954 			vm_phys_fictitious_init_range(fp, start, dpage_count,
955 			    memattr);
956 			page_count -= dpage_count;
957 			start += ptoa(dpage_count);
958 			goto alloc;
959 		}
960 		/*
961 		 * We can allocate the full range from vm_page_array,
962 		 * so there's no need to register the range in the tree.
963 		 */
964 		vm_phys_fictitious_init_range(fp, start, page_count, memattr);
965 		return (0);
966 	} else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
967 		/*
968 		 * We have a segment that ends inside of vm_page_array,
969 		 * but starts outside of it.
970 		 */
971 		fp = &vm_page_array[0];
972 		dpage_count = pe - first_page;
973 		vm_phys_fictitious_init_range(fp, ptoa(first_page), dpage_count,
974 		    memattr);
975 		end -= ptoa(dpage_count);
976 		page_count -= dpage_count;
977 		goto alloc;
978 	} else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
979 		/*
980 		 * Trying to register a fictitious range that expands before
981 		 * and after vm_page_array.
982 		 */
983 		return (EINVAL);
984 	} else {
985 alloc:
986 #endif
987 		fp = malloc(page_count * sizeof(struct vm_page), M_FICT_PAGES,
988 		    M_WAITOK | M_ZERO);
989 #ifdef VM_PHYSSEG_DENSE
990 	}
991 #endif
992 	vm_phys_fictitious_init_range(fp, start, page_count, memattr);
993 
994 	seg = malloc(sizeof(*seg), M_FICT_PAGES, M_WAITOK | M_ZERO);
995 	seg->start = start;
996 	seg->end = end;
997 	seg->first_page = fp;
998 
999 	rw_wlock(&vm_phys_fictitious_reg_lock);
1000 	RB_INSERT(fict_tree, &vm_phys_fictitious_tree, seg);
1001 	rw_wunlock(&vm_phys_fictitious_reg_lock);
1002 
1003 	return (0);
1004 }
1005 
1006 void
1007 vm_phys_fictitious_unreg_range(vm_paddr_t start, vm_paddr_t end)
1008 {
1009 	struct vm_phys_fictitious_seg *seg, tmp;
1010 #ifdef VM_PHYSSEG_DENSE
1011 	long pi, pe;
1012 #endif
1013 
1014 	KASSERT(start < end,
1015 	    ("Start of segment isn't less than end (start: %jx end: %jx)",
1016 	    (uintmax_t)start, (uintmax_t)end));
1017 
1018 #ifdef VM_PHYSSEG_DENSE
1019 	pi = atop(start);
1020 	pe = atop(end);
1021 	if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
1022 		if ((pe - first_page) <= vm_page_array_size) {
1023 			/*
1024 			 * This segment was allocated using vm_page_array
1025 			 * only, there's nothing to do since those pages
1026 			 * were never added to the tree.
1027 			 */
1028 			return;
1029 		}
1030 		/*
1031 		 * We have a segment that starts inside
1032 		 * of vm_page_array, but ends outside of it.
1033 		 *
1034 		 * Calculate how many pages were added to the
1035 		 * tree and free them.
1036 		 */
1037 		start = ptoa(first_page + vm_page_array_size);
1038 	} else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
1039 		/*
1040 		 * We have a segment that ends inside of vm_page_array,
1041 		 * but starts outside of it.
1042 		 */
1043 		end = ptoa(first_page);
1044 	} else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
1045 		/* Since it's not possible to register such a range, panic. */
1046 		panic(
1047 		    "Unregistering not registered fictitious range [%#jx:%#jx]",
1048 		    (uintmax_t)start, (uintmax_t)end);
1049 	}
1050 #endif
1051 	tmp.start = start;
1052 	tmp.end = 0;
1053 
1054 	rw_wlock(&vm_phys_fictitious_reg_lock);
1055 	seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
1056 	if (seg->start != start || seg->end != end) {
1057 		rw_wunlock(&vm_phys_fictitious_reg_lock);
1058 		panic(
1059 		    "Unregistering not registered fictitious range [%#jx:%#jx]",
1060 		    (uintmax_t)start, (uintmax_t)end);
1061 	}
1062 	RB_REMOVE(fict_tree, &vm_phys_fictitious_tree, seg);
1063 	rw_wunlock(&vm_phys_fictitious_reg_lock);
1064 	free(seg->first_page, M_FICT_PAGES);
1065 	free(seg, M_FICT_PAGES);
1066 }
1067 
1068 /*
1069  * Find the segment containing the given physical address.
1070  */
1071 static int
1072 vm_phys_paddr_to_segind(vm_paddr_t pa)
1073 {
1074 	struct vm_phys_seg *seg;
1075 	int segind;
1076 
1077 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
1078 		seg = &vm_phys_segs[segind];
1079 		if (pa >= seg->start && pa < seg->end)
1080 			return (segind);
1081 	}
1082 	panic("vm_phys_paddr_to_segind: paddr %#jx is not in any segment" ,
1083 	    (uintmax_t)pa);
1084 }
1085 
1086 /*
1087  * Free a contiguous, power of two-sized set of physical pages.
1088  *
1089  * The free page queues must be locked.
1090  */
1091 void
1092 vm_phys_free_pages(vm_page_t m, int order)
1093 {
1094 	struct vm_freelist *fl;
1095 	struct vm_phys_seg *seg;
1096 	vm_paddr_t pa;
1097 	vm_page_t m_buddy;
1098 
1099 	KASSERT(m->order == VM_NFREEORDER,
1100 	    ("vm_phys_free_pages: page %p has unexpected order %d",
1101 	    m, m->order));
1102 	KASSERT(m->pool < VM_NFREEPOOL,
1103 	    ("vm_phys_free_pages: page %p has unexpected pool %d",
1104 	    m, m->pool));
1105 	KASSERT(order < VM_NFREEORDER,
1106 	    ("vm_phys_free_pages: order %d is out of range", order));
1107 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1108 	seg = &vm_phys_segs[m->segind];
1109 	if (order < VM_NFREEORDER - 1) {
1110 		pa = VM_PAGE_TO_PHYS(m);
1111 		do {
1112 			pa ^= ((vm_paddr_t)1 << (PAGE_SHIFT + order));
1113 			if (pa < seg->start || pa >= seg->end)
1114 				break;
1115 			m_buddy = &seg->first_page[atop(pa - seg->start)];
1116 			if (m_buddy->order != order)
1117 				break;
1118 			fl = (*seg->free_queues)[m_buddy->pool];
1119 			vm_freelist_rem(fl, m_buddy, order);
1120 			if (m_buddy->pool != m->pool)
1121 				vm_phys_set_pool(m->pool, m_buddy, order);
1122 			order++;
1123 			pa &= ~(((vm_paddr_t)1 << (PAGE_SHIFT + order)) - 1);
1124 			m = &seg->first_page[atop(pa - seg->start)];
1125 		} while (order < VM_NFREEORDER - 1);
1126 	}
1127 	fl = (*seg->free_queues)[m->pool];
1128 	vm_freelist_add(fl, m, order, 1);
1129 }
1130 
1131 /*
1132  * Free a contiguous, arbitrarily sized set of physical pages.
1133  *
1134  * The free page queues must be locked.
1135  */
1136 void
1137 vm_phys_free_contig(vm_page_t m, u_long npages)
1138 {
1139 	u_int n;
1140 	int order;
1141 
1142 	/*
1143 	 * Avoid unnecessary coalescing by freeing the pages in the largest
1144 	 * possible power-of-two-sized subsets.
1145 	 */
1146 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1147 	for (;; npages -= n) {
1148 		/*
1149 		 * Unsigned "min" is used here so that "order" is assigned
1150 		 * "VM_NFREEORDER - 1" when "m"'s physical address is zero
1151 		 * or the low-order bits of its physical address are zero
1152 		 * because the size of a physical address exceeds the size of
1153 		 * a long.
1154 		 */
1155 		order = min(ffsl(VM_PAGE_TO_PHYS(m) >> PAGE_SHIFT) - 1,
1156 		    VM_NFREEORDER - 1);
1157 		n = 1 << order;
1158 		if (npages < n)
1159 			break;
1160 		vm_phys_free_pages(m, order);
1161 		m += n;
1162 	}
1163 	/* The residual "npages" is less than "1 << (VM_NFREEORDER - 1)". */
1164 	for (; npages > 0; npages -= n) {
1165 		order = flsl(npages) - 1;
1166 		n = 1 << order;
1167 		vm_phys_free_pages(m, order);
1168 		m += n;
1169 	}
1170 }
1171 
1172 /*
1173  * Scan physical memory between the specified addresses "low" and "high" for a
1174  * run of contiguous physical pages that satisfy the specified conditions, and
1175  * return the lowest page in the run.  The specified "alignment" determines
1176  * the alignment of the lowest physical page in the run.  If the specified
1177  * "boundary" is non-zero, then the run of physical pages cannot span a
1178  * physical address that is a multiple of "boundary".
1179  *
1180  * "npages" must be greater than zero.  Both "alignment" and "boundary" must
1181  * be a power of two.
1182  */
1183 vm_page_t
1184 vm_phys_scan_contig(u_long npages, vm_paddr_t low, vm_paddr_t high,
1185     u_long alignment, vm_paddr_t boundary, int options)
1186 {
1187 	vm_paddr_t pa_end;
1188 	vm_page_t m_end, m_run, m_start;
1189 	struct vm_phys_seg *seg;
1190 	int segind;
1191 
1192 	KASSERT(npages > 0, ("npages is 0"));
1193 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1194 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1195 	if (low >= high)
1196 		return (NULL);
1197 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
1198 		seg = &vm_phys_segs[segind];
1199 		if (seg->start >= high)
1200 			break;
1201 		if (low >= seg->end)
1202 			continue;
1203 		if (low <= seg->start)
1204 			m_start = seg->first_page;
1205 		else
1206 			m_start = &seg->first_page[atop(low - seg->start)];
1207 		if (high < seg->end)
1208 			pa_end = high;
1209 		else
1210 			pa_end = seg->end;
1211 		if (pa_end - VM_PAGE_TO_PHYS(m_start) < ptoa(npages))
1212 			continue;
1213 		m_end = &seg->first_page[atop(pa_end - seg->start)];
1214 		m_run = vm_page_scan_contig(npages, m_start, m_end,
1215 		    alignment, boundary, options);
1216 		if (m_run != NULL)
1217 			return (m_run);
1218 	}
1219 	return (NULL);
1220 }
1221 
1222 /*
1223  * Set the pool for a contiguous, power of two-sized set of physical pages.
1224  */
1225 void
1226 vm_phys_set_pool(int pool, vm_page_t m, int order)
1227 {
1228 	vm_page_t m_tmp;
1229 
1230 	for (m_tmp = m; m_tmp < &m[1 << order]; m_tmp++)
1231 		m_tmp->pool = pool;
1232 }
1233 
1234 /*
1235  * Search for the given physical page "m" in the free lists.  If the search
1236  * succeeds, remove "m" from the free lists and return TRUE.  Otherwise, return
1237  * FALSE, indicating that "m" is not in the free lists.
1238  *
1239  * The free page queues must be locked.
1240  */
1241 boolean_t
1242 vm_phys_unfree_page(vm_page_t m)
1243 {
1244 	struct vm_freelist *fl;
1245 	struct vm_phys_seg *seg;
1246 	vm_paddr_t pa, pa_half;
1247 	vm_page_t m_set, m_tmp;
1248 	int order;
1249 
1250 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1251 
1252 	/*
1253 	 * First, find the contiguous, power of two-sized set of free
1254 	 * physical pages containing the given physical page "m" and
1255 	 * assign it to "m_set".
1256 	 */
1257 	seg = &vm_phys_segs[m->segind];
1258 	for (m_set = m, order = 0; m_set->order == VM_NFREEORDER &&
1259 	    order < VM_NFREEORDER - 1; ) {
1260 		order++;
1261 		pa = m->phys_addr & (~(vm_paddr_t)0 << (PAGE_SHIFT + order));
1262 		if (pa >= seg->start)
1263 			m_set = &seg->first_page[atop(pa - seg->start)];
1264 		else
1265 			return (FALSE);
1266 	}
1267 	if (m_set->order < order)
1268 		return (FALSE);
1269 	if (m_set->order == VM_NFREEORDER)
1270 		return (FALSE);
1271 	KASSERT(m_set->order < VM_NFREEORDER,
1272 	    ("vm_phys_unfree_page: page %p has unexpected order %d",
1273 	    m_set, m_set->order));
1274 
1275 	/*
1276 	 * Next, remove "m_set" from the free lists.  Finally, extract
1277 	 * "m" from "m_set" using an iterative algorithm: While "m_set"
1278 	 * is larger than a page, shrink "m_set" by returning the half
1279 	 * of "m_set" that does not contain "m" to the free lists.
1280 	 */
1281 	fl = (*seg->free_queues)[m_set->pool];
1282 	order = m_set->order;
1283 	vm_freelist_rem(fl, m_set, order);
1284 	while (order > 0) {
1285 		order--;
1286 		pa_half = m_set->phys_addr ^ (1 << (PAGE_SHIFT + order));
1287 		if (m->phys_addr < pa_half)
1288 			m_tmp = &seg->first_page[atop(pa_half - seg->start)];
1289 		else {
1290 			m_tmp = m_set;
1291 			m_set = &seg->first_page[atop(pa_half - seg->start)];
1292 		}
1293 		vm_freelist_add(fl, m_tmp, order, 0);
1294 	}
1295 	KASSERT(m_set == m, ("vm_phys_unfree_page: fatal inconsistency"));
1296 	return (TRUE);
1297 }
1298 
1299 /*
1300  * Try to zero one physical page.  Used by an idle priority thread.
1301  */
1302 boolean_t
1303 vm_phys_zero_pages_idle(void)
1304 {
1305 	static struct vm_freelist *fl;
1306 	static int flind, oind, pind;
1307 	vm_page_t m, m_tmp;
1308 	int domain;
1309 
1310 	domain = vm_rr_selectdomain();
1311 	fl = vm_phys_free_queues[domain][0][0];
1312 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1313 	for (;;) {
1314 		TAILQ_FOREACH_REVERSE(m, &fl[oind].pl, pglist, plinks.q) {
1315 			for (m_tmp = m; m_tmp < &m[1 << oind]; m_tmp++) {
1316 				if ((m_tmp->flags & (PG_CACHED | PG_ZERO)) == 0) {
1317 					vm_phys_unfree_page(m_tmp);
1318 					vm_phys_freecnt_adj(m, -1);
1319 					mtx_unlock(&vm_page_queue_free_mtx);
1320 					pmap_zero_page_idle(m_tmp);
1321 					m_tmp->flags |= PG_ZERO;
1322 					mtx_lock(&vm_page_queue_free_mtx);
1323 					vm_phys_freecnt_adj(m, 1);
1324 					vm_phys_free_pages(m_tmp, 0);
1325 					vm_page_zero_count++;
1326 					cnt_prezero++;
1327 					return (TRUE);
1328 				}
1329 			}
1330 		}
1331 		oind++;
1332 		if (oind == VM_NFREEORDER) {
1333 			oind = 0;
1334 			pind++;
1335 			if (pind == VM_NFREEPOOL) {
1336 				pind = 0;
1337 				flind++;
1338 				if (flind == vm_nfreelists)
1339 					flind = 0;
1340 			}
1341 			fl = vm_phys_free_queues[domain][flind][pind];
1342 		}
1343 	}
1344 }
1345 
1346 /*
1347  * Allocate a contiguous set of physical pages of the given size
1348  * "npages" from the free lists.  All of the physical pages must be at
1349  * or above the given physical address "low" and below the given
1350  * physical address "high".  The given value "alignment" determines the
1351  * alignment of the first physical page in the set.  If the given value
1352  * "boundary" is non-zero, then the set of physical pages cannot cross
1353  * any physical address boundary that is a multiple of that value.  Both
1354  * "alignment" and "boundary" must be a power of two.
1355  */
1356 vm_page_t
1357 vm_phys_alloc_contig(u_long npages, vm_paddr_t low, vm_paddr_t high,
1358     u_long alignment, vm_paddr_t boundary)
1359 {
1360 	vm_paddr_t pa_end, pa_start;
1361 	vm_page_t m_run;
1362 	struct vm_domain_iterator vi;
1363 	struct vm_phys_seg *seg;
1364 	int domain, segind;
1365 
1366 	KASSERT(npages > 0, ("npages is 0"));
1367 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1368 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1369 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1370 	if (low >= high)
1371 		return (NULL);
1372 	vm_policy_iterator_init(&vi);
1373 restartdom:
1374 	if (vm_domain_iterator_run(&vi, &domain) != 0) {
1375 		vm_policy_iterator_finish(&vi);
1376 		return (NULL);
1377 	}
1378 	m_run = NULL;
1379 	for (segind = vm_phys_nsegs - 1; segind >= 0; segind--) {
1380 		seg = &vm_phys_segs[segind];
1381 		if (seg->start >= high || seg->domain != domain)
1382 			continue;
1383 		if (low >= seg->end)
1384 			break;
1385 		if (low <= seg->start)
1386 			pa_start = seg->start;
1387 		else
1388 			pa_start = low;
1389 		if (high < seg->end)
1390 			pa_end = high;
1391 		else
1392 			pa_end = seg->end;
1393 		if (pa_end - pa_start < ptoa(npages))
1394 			continue;
1395 		m_run = vm_phys_alloc_seg_contig(seg, npages, low, high,
1396 		    alignment, boundary);
1397 		if (m_run != NULL)
1398 			break;
1399 	}
1400 	if (m_run == NULL && !vm_domain_iterator_isdone(&vi))
1401 		goto restartdom;
1402 	vm_policy_iterator_finish(&vi);
1403 	return (m_run);
1404 }
1405 
1406 /*
1407  * Allocate a run of contiguous physical pages from the free list for the
1408  * specified segment.
1409  */
1410 static vm_page_t
1411 vm_phys_alloc_seg_contig(struct vm_phys_seg *seg, u_long npages,
1412     vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
1413 {
1414 	struct vm_freelist *fl;
1415 	vm_paddr_t pa, pa_end, size;
1416 	vm_page_t m, m_ret;
1417 	u_long npages_end;
1418 	int oind, order, pind;
1419 
1420 	KASSERT(npages > 0, ("npages is 0"));
1421 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1422 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1423 	mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1424 	/* Compute the queue that is the best fit for npages. */
1425 	for (order = 0; (1 << order) < npages; order++);
1426 	/* Search for a run satisfying the specified conditions. */
1427 	size = npages << PAGE_SHIFT;
1428 	for (oind = min(order, VM_NFREEORDER - 1); oind < VM_NFREEORDER;
1429 	    oind++) {
1430 		for (pind = 0; pind < VM_NFREEPOOL; pind++) {
1431 			fl = (*seg->free_queues)[pind];
1432 			TAILQ_FOREACH(m_ret, &fl[oind].pl, plinks.q) {
1433 				/*
1434 				 * Is the size of this allocation request
1435 				 * larger than the largest block size?
1436 				 */
1437 				if (order >= VM_NFREEORDER) {
1438 					/*
1439 					 * Determine if a sufficient number of
1440 					 * subsequent blocks to satisfy the
1441 					 * allocation request are free.
1442 					 */
1443 					pa = VM_PAGE_TO_PHYS(m_ret);
1444 					pa_end = pa + size;
1445 					for (;;) {
1446 						pa += 1 << (PAGE_SHIFT +
1447 						    VM_NFREEORDER - 1);
1448 						if (pa >= pa_end ||
1449 						    pa < seg->start ||
1450 						    pa >= seg->end)
1451 							break;
1452 						m = &seg->first_page[atop(pa -
1453 						    seg->start)];
1454 						if (m->order != VM_NFREEORDER -
1455 						    1)
1456 							break;
1457 					}
1458 					/* If not, go to the next block. */
1459 					if (pa < pa_end)
1460 						continue;
1461 				}
1462 
1463 				/*
1464 				 * Determine if the blocks are within the
1465 				 * given range, satisfy the given alignment,
1466 				 * and do not cross the given boundary.
1467 				 */
1468 				pa = VM_PAGE_TO_PHYS(m_ret);
1469 				pa_end = pa + size;
1470 				if (pa >= low && pa_end <= high && (pa &
1471 				    (alignment - 1)) == 0 && ((pa ^ (pa_end -
1472 				    1)) & ~(boundary - 1)) == 0)
1473 					goto done;
1474 			}
1475 		}
1476 	}
1477 	return (NULL);
1478 done:
1479 	for (m = m_ret; m < &m_ret[npages]; m = &m[1 << oind]) {
1480 		fl = (*seg->free_queues)[m->pool];
1481 		vm_freelist_rem(fl, m, m->order);
1482 	}
1483 	if (m_ret->pool != VM_FREEPOOL_DEFAULT)
1484 		vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m_ret, oind);
1485 	fl = (*seg->free_queues)[m_ret->pool];
1486 	vm_phys_split_pages(m_ret, oind, fl, order);
1487 	/* Return excess pages to the free lists. */
1488 	npages_end = roundup2(npages, 1 << imin(oind, order));
1489 	if (npages < npages_end)
1490 		vm_phys_free_contig(&m_ret[npages], npages_end - npages);
1491 	return (m_ret);
1492 }
1493 
1494 #ifdef DDB
1495 /*
1496  * Show the number of physical pages in each of the free lists.
1497  */
1498 DB_SHOW_COMMAND(freepages, db_show_freepages)
1499 {
1500 	struct vm_freelist *fl;
1501 	int flind, oind, pind, dom;
1502 
1503 	for (dom = 0; dom < vm_ndomains; dom++) {
1504 		db_printf("DOMAIN: %d\n", dom);
1505 		for (flind = 0; flind < vm_nfreelists; flind++) {
1506 			db_printf("FREE LIST %d:\n"
1507 			    "\n  ORDER (SIZE)  |  NUMBER"
1508 			    "\n              ", flind);
1509 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
1510 				db_printf("  |  POOL %d", pind);
1511 			db_printf("\n--            ");
1512 			for (pind = 0; pind < VM_NFREEPOOL; pind++)
1513 				db_printf("-- --      ");
1514 			db_printf("--\n");
1515 			for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
1516 				db_printf("  %2.2d (%6.6dK)", oind,
1517 				    1 << (PAGE_SHIFT - 10 + oind));
1518 				for (pind = 0; pind < VM_NFREEPOOL; pind++) {
1519 				fl = vm_phys_free_queues[dom][flind][pind];
1520 					db_printf("  |  %6.6d", fl[oind].lcnt);
1521 				}
1522 				db_printf("\n");
1523 			}
1524 			db_printf("\n");
1525 		}
1526 		db_printf("\n");
1527 	}
1528 }
1529 #endif
1530