FreeBSD/Linux Kernel Cross Reference
sys/vm/vm_phys.c
1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2002-2006 Rice University
5 * Copyright (c) 2007 Alan L. Cox <alc@cs.rice.edu>
6 * All rights reserved.
7 *
8 * This software was developed for the FreeBSD Project by Alan L. Cox,
9 * Olivier Crameri, Peter Druschel, Sitaram Iyer, and Juan Navarro.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
30 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 /*
35 * Physical memory system implementation
36 *
37 * Any external functions defined by this module are only to be used by the
38 * virtual memory system.
39 */
40
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD: releng/12.0/sys/vm/vm_phys.c 340007 2018-11-01 16:50:19Z markj $");
43
44 #include "opt_ddb.h"
45 #include "opt_vm.h"
46
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/domainset.h>
50 #include <sys/lock.h>
51 #include <sys/kernel.h>
52 #include <sys/malloc.h>
53 #include <sys/mutex.h>
54 #include <sys/proc.h>
55 #include <sys/queue.h>
56 #include <sys/rwlock.h>
57 #include <sys/sbuf.h>
58 #include <sys/sysctl.h>
59 #include <sys/tree.h>
60 #include <sys/vmmeter.h>
61 #include <sys/seq.h>
62
63 #include <ddb/ddb.h>
64
65 #include <vm/vm.h>
66 #include <vm/vm_param.h>
67 #include <vm/vm_kern.h>
68 #include <vm/vm_object.h>
69 #include <vm/vm_page.h>
70 #include <vm/vm_phys.h>
71 #include <vm/vm_pagequeue.h>
72
73 _Static_assert(sizeof(long) * NBBY >= VM_PHYSSEG_MAX,
74 "Too many physsegs.");
75
76 #ifdef NUMA
77 struct mem_affinity __read_mostly *mem_affinity;
78 int __read_mostly *mem_locality;
79 #endif
80
81 int __read_mostly vm_ndomains = 1;
82 domainset_t __read_mostly all_domains = DOMAINSET_T_INITIALIZER(0x1);
83
84 struct vm_phys_seg __read_mostly vm_phys_segs[VM_PHYSSEG_MAX];
85 int __read_mostly vm_phys_nsegs;
86
87 struct vm_phys_fictitious_seg;
88 static int vm_phys_fictitious_cmp(struct vm_phys_fictitious_seg *,
89 struct vm_phys_fictitious_seg *);
90
91 RB_HEAD(fict_tree, vm_phys_fictitious_seg) vm_phys_fictitious_tree =
92 RB_INITIALIZER(_vm_phys_fictitious_tree);
93
94 struct vm_phys_fictitious_seg {
95 RB_ENTRY(vm_phys_fictitious_seg) node;
96 /* Memory region data */
97 vm_paddr_t start;
98 vm_paddr_t end;
99 vm_page_t first_page;
100 };
101
102 RB_GENERATE_STATIC(fict_tree, vm_phys_fictitious_seg, node,
103 vm_phys_fictitious_cmp);
104
105 static struct rwlock_padalign vm_phys_fictitious_reg_lock;
106 MALLOC_DEFINE(M_FICT_PAGES, "vm_fictitious", "Fictitious VM pages");
107
108 static struct vm_freelist __aligned(CACHE_LINE_SIZE)
109 vm_phys_free_queues[MAXMEMDOM][VM_NFREELIST][VM_NFREEPOOL][VM_NFREEORDER];
110
111 static int __read_mostly vm_nfreelists;
112
113 /*
114 * Provides the mapping from VM_FREELIST_* to free list indices (flind).
115 */
116 static int __read_mostly vm_freelist_to_flind[VM_NFREELIST];
117
118 CTASSERT(VM_FREELIST_DEFAULT == 0);
119
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_LOWMEM_BOUNDARY) && defined(VM_DMA32_BOUNDARY)
129 CTASSERT(VM_LOWMEM_BOUNDARY < VM_DMA32_BOUNDARY);
130 #endif
131
132 static int sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS);
133 SYSCTL_OID(_vm, OID_AUTO, phys_free, CTLTYPE_STRING | CTLFLAG_RD,
134 NULL, 0, sysctl_vm_phys_free, "A", "Phys Free Info");
135
136 static int sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS);
137 SYSCTL_OID(_vm, OID_AUTO, phys_segs, CTLTYPE_STRING | CTLFLAG_RD,
138 NULL, 0, sysctl_vm_phys_segs, "A", "Phys Seg Info");
139
140 #ifdef NUMA
141 static int sysctl_vm_phys_locality(SYSCTL_HANDLER_ARGS);
142 SYSCTL_OID(_vm, OID_AUTO, phys_locality, CTLTYPE_STRING | CTLFLAG_RD,
143 NULL, 0, sysctl_vm_phys_locality, "A", "Phys Locality Info");
144 #endif
145
146 SYSCTL_INT(_vm, OID_AUTO, ndomains, CTLFLAG_RD,
147 &vm_ndomains, 0, "Number of physical memory domains available.");
148
149 static vm_page_t vm_phys_alloc_seg_contig(struct vm_phys_seg *seg,
150 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
151 vm_paddr_t boundary);
152 static void _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int domain);
153 static void vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end);
154 static void vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl,
155 int order, int tail);
156
157 /*
158 * Red-black tree helpers for vm fictitious range management.
159 */
160 static inline int
161 vm_phys_fictitious_in_range(struct vm_phys_fictitious_seg *p,
162 struct vm_phys_fictitious_seg *range)
163 {
164
165 KASSERT(range->start != 0 && range->end != 0,
166 ("Invalid range passed on search for vm_fictitious page"));
167 if (p->start >= range->end)
168 return (1);
169 if (p->start < range->start)
170 return (-1);
171
172 return (0);
173 }
174
175 static int
176 vm_phys_fictitious_cmp(struct vm_phys_fictitious_seg *p1,
177 struct vm_phys_fictitious_seg *p2)
178 {
179
180 /* Check if this is a search for a page */
181 if (p1->end == 0)
182 return (vm_phys_fictitious_in_range(p1, p2));
183
184 KASSERT(p2->end != 0,
185 ("Invalid range passed as second parameter to vm fictitious comparison"));
186
187 /* Searching to add a new range */
188 if (p1->end <= p2->start)
189 return (-1);
190 if (p1->start >= p2->end)
191 return (1);
192
193 panic("Trying to add overlapping vm fictitious ranges:\n"
194 "[%#jx:%#jx] and [%#jx:%#jx]", (uintmax_t)p1->start,
195 (uintmax_t)p1->end, (uintmax_t)p2->start, (uintmax_t)p2->end);
196 }
197
198 int
199 vm_phys_domain_match(int prefer, vm_paddr_t low, vm_paddr_t high)
200 {
201 #ifdef NUMA
202 domainset_t mask;
203 int i;
204
205 if (vm_ndomains == 1 || mem_affinity == NULL)
206 return (0);
207
208 DOMAINSET_ZERO(&mask);
209 /*
210 * Check for any memory that overlaps low, high.
211 */
212 for (i = 0; mem_affinity[i].end != 0; i++)
213 if (mem_affinity[i].start <= high &&
214 mem_affinity[i].end >= low)
215 DOMAINSET_SET(mem_affinity[i].domain, &mask);
216 if (prefer != -1 && DOMAINSET_ISSET(prefer, &mask))
217 return (prefer);
218 if (DOMAINSET_EMPTY(&mask))
219 panic("vm_phys_domain_match: Impossible constraint");
220 return (DOMAINSET_FFS(&mask) - 1);
221 #else
222 return (0);
223 #endif
224 }
225
226 /*
227 * Outputs the state of the physical memory allocator, specifically,
228 * the amount of physical memory in each free list.
229 */
230 static int
231 sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS)
232 {
233 struct sbuf sbuf;
234 struct vm_freelist *fl;
235 int dom, error, flind, oind, pind;
236
237 error = sysctl_wire_old_buffer(req, 0);
238 if (error != 0)
239 return (error);
240 sbuf_new_for_sysctl(&sbuf, NULL, 128 * vm_ndomains, req);
241 for (dom = 0; dom < vm_ndomains; dom++) {
242 sbuf_printf(&sbuf,"\nDOMAIN %d:\n", dom);
243 for (flind = 0; flind < vm_nfreelists; flind++) {
244 sbuf_printf(&sbuf, "\nFREE LIST %d:\n"
245 "\n ORDER (SIZE) | NUMBER"
246 "\n ", flind);
247 for (pind = 0; pind < VM_NFREEPOOL; pind++)
248 sbuf_printf(&sbuf, " | POOL %d", pind);
249 sbuf_printf(&sbuf, "\n-- ");
250 for (pind = 0; pind < VM_NFREEPOOL; pind++)
251 sbuf_printf(&sbuf, "-- -- ");
252 sbuf_printf(&sbuf, "--\n");
253 for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
254 sbuf_printf(&sbuf, " %2d (%6dK)", oind,
255 1 << (PAGE_SHIFT - 10 + oind));
256 for (pind = 0; pind < VM_NFREEPOOL; pind++) {
257 fl = vm_phys_free_queues[dom][flind][pind];
258 sbuf_printf(&sbuf, " | %6d",
259 fl[oind].lcnt);
260 }
261 sbuf_printf(&sbuf, "\n");
262 }
263 }
264 }
265 error = sbuf_finish(&sbuf);
266 sbuf_delete(&sbuf);
267 return (error);
268 }
269
270 /*
271 * Outputs the set of physical memory segments.
272 */
273 static int
274 sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS)
275 {
276 struct sbuf sbuf;
277 struct vm_phys_seg *seg;
278 int error, segind;
279
280 error = sysctl_wire_old_buffer(req, 0);
281 if (error != 0)
282 return (error);
283 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
284 for (segind = 0; segind < vm_phys_nsegs; segind++) {
285 sbuf_printf(&sbuf, "\nSEGMENT %d:\n\n", segind);
286 seg = &vm_phys_segs[segind];
287 sbuf_printf(&sbuf, "start: %#jx\n",
288 (uintmax_t)seg->start);
289 sbuf_printf(&sbuf, "end: %#jx\n",
290 (uintmax_t)seg->end);
291 sbuf_printf(&sbuf, "domain: %d\n", seg->domain);
292 sbuf_printf(&sbuf, "free list: %p\n", seg->free_queues);
293 }
294 error = sbuf_finish(&sbuf);
295 sbuf_delete(&sbuf);
296 return (error);
297 }
298
299 /*
300 * Return affinity, or -1 if there's no affinity information.
301 */
302 int
303 vm_phys_mem_affinity(int f, int t)
304 {
305
306 #ifdef NUMA
307 if (mem_locality == NULL)
308 return (-1);
309 if (f >= vm_ndomains || t >= vm_ndomains)
310 return (-1);
311 return (mem_locality[f * vm_ndomains + t]);
312 #else
313 return (-1);
314 #endif
315 }
316
317 #ifdef NUMA
318 /*
319 * Outputs the VM locality table.
320 */
321 static int
322 sysctl_vm_phys_locality(SYSCTL_HANDLER_ARGS)
323 {
324 struct sbuf sbuf;
325 int error, i, j;
326
327 error = sysctl_wire_old_buffer(req, 0);
328 if (error != 0)
329 return (error);
330 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
331
332 sbuf_printf(&sbuf, "\n");
333
334 for (i = 0; i < vm_ndomains; i++) {
335 sbuf_printf(&sbuf, "%d: ", i);
336 for (j = 0; j < vm_ndomains; j++) {
337 sbuf_printf(&sbuf, "%d ", vm_phys_mem_affinity(i, j));
338 }
339 sbuf_printf(&sbuf, "\n");
340 }
341 error = sbuf_finish(&sbuf);
342 sbuf_delete(&sbuf);
343 return (error);
344 }
345 #endif
346
347 static void
348 vm_freelist_add(struct vm_freelist *fl, vm_page_t m, int order, int tail)
349 {
350
351 m->order = order;
352 if (tail)
353 TAILQ_INSERT_TAIL(&fl[order].pl, m, listq);
354 else
355 TAILQ_INSERT_HEAD(&fl[order].pl, m, listq);
356 fl[order].lcnt++;
357 }
358
359 static void
360 vm_freelist_rem(struct vm_freelist *fl, vm_page_t m, int order)
361 {
362
363 TAILQ_REMOVE(&fl[order].pl, m, listq);
364 fl[order].lcnt--;
365 m->order = VM_NFREEORDER;
366 }
367
368 /*
369 * Create a physical memory segment.
370 */
371 static void
372 _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int domain)
373 {
374 struct vm_phys_seg *seg;
375
376 KASSERT(vm_phys_nsegs < VM_PHYSSEG_MAX,
377 ("vm_phys_create_seg: increase VM_PHYSSEG_MAX"));
378 KASSERT(domain >= 0 && domain < vm_ndomains,
379 ("vm_phys_create_seg: invalid domain provided"));
380 seg = &vm_phys_segs[vm_phys_nsegs++];
381 while (seg > vm_phys_segs && (seg - 1)->start >= end) {
382 *seg = *(seg - 1);
383 seg--;
384 }
385 seg->start = start;
386 seg->end = end;
387 seg->domain = domain;
388 }
389
390 static void
391 vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end)
392 {
393 #ifdef NUMA
394 int i;
395
396 if (mem_affinity == NULL) {
397 _vm_phys_create_seg(start, end, 0);
398 return;
399 }
400
401 for (i = 0;; i++) {
402 if (mem_affinity[i].end == 0)
403 panic("Reached end of affinity info");
404 if (mem_affinity[i].end <= start)
405 continue;
406 if (mem_affinity[i].start > start)
407 panic("No affinity info for start %jx",
408 (uintmax_t)start);
409 if (mem_affinity[i].end >= end) {
410 _vm_phys_create_seg(start, end,
411 mem_affinity[i].domain);
412 break;
413 }
414 _vm_phys_create_seg(start, mem_affinity[i].end,
415 mem_affinity[i].domain);
416 start = mem_affinity[i].end;
417 }
418 #else
419 _vm_phys_create_seg(start, end, 0);
420 #endif
421 }
422
423 /*
424 * Add a physical memory segment.
425 */
426 void
427 vm_phys_add_seg(vm_paddr_t start, vm_paddr_t end)
428 {
429 vm_paddr_t paddr;
430
431 KASSERT((start & PAGE_MASK) == 0,
432 ("vm_phys_define_seg: start is not page aligned"));
433 KASSERT((end & PAGE_MASK) == 0,
434 ("vm_phys_define_seg: end is not page aligned"));
435
436 /*
437 * Split the physical memory segment if it spans two or more free
438 * list boundaries.
439 */
440 paddr = start;
441 #ifdef VM_FREELIST_LOWMEM
442 if (paddr < VM_LOWMEM_BOUNDARY && end > VM_LOWMEM_BOUNDARY) {
443 vm_phys_create_seg(paddr, VM_LOWMEM_BOUNDARY);
444 paddr = VM_LOWMEM_BOUNDARY;
445 }
446 #endif
447 #ifdef VM_FREELIST_DMA32
448 if (paddr < VM_DMA32_BOUNDARY && end > VM_DMA32_BOUNDARY) {
449 vm_phys_create_seg(paddr, VM_DMA32_BOUNDARY);
450 paddr = VM_DMA32_BOUNDARY;
451 }
452 #endif
453 vm_phys_create_seg(paddr, end);
454 }
455
456 /*
457 * Initialize the physical memory allocator.
458 *
459 * Requires that vm_page_array is initialized!
460 */
461 void
462 vm_phys_init(void)
463 {
464 struct vm_freelist *fl;
465 struct vm_phys_seg *end_seg, *prev_seg, *seg, *tmp_seg;
466 u_long npages;
467 int dom, flind, freelist, oind, pind, segind;
468
469 /*
470 * Compute the number of free lists, and generate the mapping from the
471 * manifest constants VM_FREELIST_* to the free list indices.
472 *
473 * Initially, the entries of vm_freelist_to_flind[] are set to either
474 * 0 or 1 to indicate which free lists should be created.
475 */
476 npages = 0;
477 for (segind = vm_phys_nsegs - 1; segind >= 0; segind--) {
478 seg = &vm_phys_segs[segind];
479 #ifdef VM_FREELIST_LOWMEM
480 if (seg->end <= VM_LOWMEM_BOUNDARY)
481 vm_freelist_to_flind[VM_FREELIST_LOWMEM] = 1;
482 else
483 #endif
484 #ifdef VM_FREELIST_DMA32
485 if (
486 #ifdef VM_DMA32_NPAGES_THRESHOLD
487 /*
488 * Create the DMA32 free list only if the amount of
489 * physical memory above physical address 4G exceeds the
490 * given threshold.
491 */
492 npages > VM_DMA32_NPAGES_THRESHOLD &&
493 #endif
494 seg->end <= VM_DMA32_BOUNDARY)
495 vm_freelist_to_flind[VM_FREELIST_DMA32] = 1;
496 else
497 #endif
498 {
499 npages += atop(seg->end - seg->start);
500 vm_freelist_to_flind[VM_FREELIST_DEFAULT] = 1;
501 }
502 }
503 /* Change each entry into a running total of the free lists. */
504 for (freelist = 1; freelist < VM_NFREELIST; freelist++) {
505 vm_freelist_to_flind[freelist] +=
506 vm_freelist_to_flind[freelist - 1];
507 }
508 vm_nfreelists = vm_freelist_to_flind[VM_NFREELIST - 1];
509 KASSERT(vm_nfreelists > 0, ("vm_phys_init: no free lists"));
510 /* Change each entry into a free list index. */
511 for (freelist = 0; freelist < VM_NFREELIST; freelist++)
512 vm_freelist_to_flind[freelist]--;
513
514 /*
515 * Initialize the first_page and free_queues fields of each physical
516 * memory segment.
517 */
518 #ifdef VM_PHYSSEG_SPARSE
519 npages = 0;
520 #endif
521 for (segind = 0; segind < vm_phys_nsegs; segind++) {
522 seg = &vm_phys_segs[segind];
523 #ifdef VM_PHYSSEG_SPARSE
524 seg->first_page = &vm_page_array[npages];
525 npages += atop(seg->end - seg->start);
526 #else
527 seg->first_page = PHYS_TO_VM_PAGE(seg->start);
528 #endif
529 #ifdef VM_FREELIST_LOWMEM
530 if (seg->end <= VM_LOWMEM_BOUNDARY) {
531 flind = vm_freelist_to_flind[VM_FREELIST_LOWMEM];
532 KASSERT(flind >= 0,
533 ("vm_phys_init: LOWMEM flind < 0"));
534 } else
535 #endif
536 #ifdef VM_FREELIST_DMA32
537 if (seg->end <= VM_DMA32_BOUNDARY) {
538 flind = vm_freelist_to_flind[VM_FREELIST_DMA32];
539 KASSERT(flind >= 0,
540 ("vm_phys_init: DMA32 flind < 0"));
541 } else
542 #endif
543 {
544 flind = vm_freelist_to_flind[VM_FREELIST_DEFAULT];
545 KASSERT(flind >= 0,
546 ("vm_phys_init: DEFAULT flind < 0"));
547 }
548 seg->free_queues = &vm_phys_free_queues[seg->domain][flind];
549 }
550
551 /*
552 * Coalesce physical memory segments that are contiguous and share the
553 * same per-domain free queues.
554 */
555 prev_seg = vm_phys_segs;
556 seg = &vm_phys_segs[1];
557 end_seg = &vm_phys_segs[vm_phys_nsegs];
558 while (seg < end_seg) {
559 if (prev_seg->end == seg->start &&
560 prev_seg->free_queues == seg->free_queues) {
561 prev_seg->end = seg->end;
562 KASSERT(prev_seg->domain == seg->domain,
563 ("vm_phys_init: free queues cannot span domains"));
564 vm_phys_nsegs--;
565 end_seg--;
566 for (tmp_seg = seg; tmp_seg < end_seg; tmp_seg++)
567 *tmp_seg = *(tmp_seg + 1);
568 } else {
569 prev_seg = seg;
570 seg++;
571 }
572 }
573
574 /*
575 * Initialize the free queues.
576 */
577 for (dom = 0; dom < vm_ndomains; dom++) {
578 for (flind = 0; flind < vm_nfreelists; flind++) {
579 for (pind = 0; pind < VM_NFREEPOOL; pind++) {
580 fl = vm_phys_free_queues[dom][flind][pind];
581 for (oind = 0; oind < VM_NFREEORDER; oind++)
582 TAILQ_INIT(&fl[oind].pl);
583 }
584 }
585 }
586
587 rw_init(&vm_phys_fictitious_reg_lock, "vmfctr");
588 }
589
590 /*
591 * Register info about the NUMA topology of the system.
592 *
593 * Invoked by platform-dependent code prior to vm_phys_init().
594 */
595 void
596 vm_phys_register_domains(int ndomains, struct mem_affinity *affinity,
597 int *locality)
598 {
599 #ifdef NUMA
600 int d, i;
601
602 /*
603 * For now the only override value that we support is 1, which
604 * effectively disables NUMA-awareness in the allocators.
605 */
606 d = 0;
607 TUNABLE_INT_FETCH("vm.numa.disabled", &d);
608 if (d)
609 ndomains = 1;
610
611 if (ndomains > 1) {
612 vm_ndomains = ndomains;
613 mem_affinity = affinity;
614 mem_locality = locality;
615 }
616
617 for (i = 0; i < vm_ndomains; i++)
618 DOMAINSET_SET(i, &all_domains);
619 #else
620 (void)ndomains;
621 (void)affinity;
622 (void)locality;
623 #endif
624 }
625
626 /*
627 * Split a contiguous, power of two-sized set of physical pages.
628 *
629 * When this function is called by a page allocation function, the caller
630 * should request insertion at the head unless the order [order, oind) queues
631 * are known to be empty. The objective being to reduce the likelihood of
632 * long-term fragmentation by promoting contemporaneous allocation and
633 * (hopefully) deallocation.
634 */
635 static __inline void
636 vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl, int order,
637 int tail)
638 {
639 vm_page_t m_buddy;
640
641 while (oind > order) {
642 oind--;
643 m_buddy = &m[1 << oind];
644 KASSERT(m_buddy->order == VM_NFREEORDER,
645 ("vm_phys_split_pages: page %p has unexpected order %d",
646 m_buddy, m_buddy->order));
647 vm_freelist_add(fl, m_buddy, oind, tail);
648 }
649 }
650
651 /*
652 * Add the physical pages [m, m + npages) at the end of a power-of-two aligned
653 * and sized set to the specified free list.
654 *
655 * When this function is called by a page allocation function, the caller
656 * should request insertion at the head unless the lower-order queues are
657 * known to be empty. The objective being to reduce the likelihood of long-
658 * term fragmentation by promoting contemporaneous allocation and (hopefully)
659 * deallocation.
660 *
661 * The physical page m's buddy must not be free.
662 */
663 static void
664 vm_phys_enq_range(vm_page_t m, u_int npages, struct vm_freelist *fl, int tail)
665 {
666 u_int n;
667 int order;
668
669 KASSERT(npages > 0, ("vm_phys_enq_range: npages is 0"));
670 KASSERT(((VM_PAGE_TO_PHYS(m) + npages * PAGE_SIZE) &
671 ((PAGE_SIZE << (fls(npages) - 1)) - 1)) == 0,
672 ("vm_phys_enq_range: page %p and npages %u are misaligned",
673 m, npages));
674 do {
675 KASSERT(m->order == VM_NFREEORDER,
676 ("vm_phys_enq_range: page %p has unexpected order %d",
677 m, m->order));
678 order = ffs(npages) - 1;
679 KASSERT(order < VM_NFREEORDER,
680 ("vm_phys_enq_range: order %d is out of range", order));
681 vm_freelist_add(fl, m, order, tail);
682 n = 1 << order;
683 m += n;
684 npages -= n;
685 } while (npages > 0);
686 }
687
688 /*
689 * Tries to allocate the specified number of pages from the specified pool
690 * within the specified domain. Returns the actual number of allocated pages
691 * and a pointer to each page through the array ma[].
692 *
693 * The returned pages may not be physically contiguous. However, in contrast
694 * to performing multiple, back-to-back calls to vm_phys_alloc_pages(..., 0),
695 * calling this function once to allocate the desired number of pages will
696 * avoid wasted time in vm_phys_split_pages().
697 *
698 * The free page queues for the specified domain must be locked.
699 */
700 int
701 vm_phys_alloc_npages(int domain, int pool, int npages, vm_page_t ma[])
702 {
703 struct vm_freelist *alt, *fl;
704 vm_page_t m;
705 int avail, end, flind, freelist, i, need, oind, pind;
706
707 KASSERT(domain >= 0 && domain < vm_ndomains,
708 ("vm_phys_alloc_npages: domain %d is out of range", domain));
709 KASSERT(pool < VM_NFREEPOOL,
710 ("vm_phys_alloc_npages: pool %d is out of range", pool));
711 KASSERT(npages <= 1 << (VM_NFREEORDER - 1),
712 ("vm_phys_alloc_npages: npages %d is out of range", npages));
713 vm_domain_free_assert_locked(VM_DOMAIN(domain));
714 i = 0;
715 for (freelist = 0; freelist < VM_NFREELIST; freelist++) {
716 flind = vm_freelist_to_flind[freelist];
717 if (flind < 0)
718 continue;
719 fl = vm_phys_free_queues[domain][flind][pool];
720 for (oind = 0; oind < VM_NFREEORDER; oind++) {
721 while ((m = TAILQ_FIRST(&fl[oind].pl)) != NULL) {
722 vm_freelist_rem(fl, m, oind);
723 avail = 1 << oind;
724 need = imin(npages - i, avail);
725 for (end = i + need; i < end;)
726 ma[i++] = m++;
727 if (need < avail) {
728 /*
729 * Return excess pages to fl. Its
730 * order [0, oind) queues are empty.
731 */
732 vm_phys_enq_range(m, avail - need, fl,
733 1);
734 return (npages);
735 } else if (i == npages)
736 return (npages);
737 }
738 }
739 for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
740 for (pind = 0; pind < VM_NFREEPOOL; pind++) {
741 alt = vm_phys_free_queues[domain][flind][pind];
742 while ((m = TAILQ_FIRST(&alt[oind].pl)) !=
743 NULL) {
744 vm_freelist_rem(alt, m, oind);
745 vm_phys_set_pool(pool, m, oind);
746 avail = 1 << oind;
747 need = imin(npages - i, avail);
748 for (end = i + need; i < end;)
749 ma[i++] = m++;
750 if (need < avail) {
751 /*
752 * Return excess pages to fl.
753 * Its order [0, oind) queues
754 * are empty.
755 */
756 vm_phys_enq_range(m, avail -
757 need, fl, 1);
758 return (npages);
759 } else if (i == npages)
760 return (npages);
761 }
762 }
763 }
764 }
765 return (i);
766 }
767
768 /*
769 * Allocate a contiguous, power of two-sized set of physical pages
770 * from the free lists.
771 *
772 * The free page queues must be locked.
773 */
774 vm_page_t
775 vm_phys_alloc_pages(int domain, int pool, int order)
776 {
777 vm_page_t m;
778 int freelist;
779
780 for (freelist = 0; freelist < VM_NFREELIST; freelist++) {
781 m = vm_phys_alloc_freelist_pages(domain, freelist, pool, order);
782 if (m != NULL)
783 return (m);
784 }
785 return (NULL);
786 }
787
788 /*
789 * Allocate a contiguous, power of two-sized set of physical pages from the
790 * specified free list. The free list must be specified using one of the
791 * manifest constants VM_FREELIST_*.
792 *
793 * The free page queues must be locked.
794 */
795 vm_page_t
796 vm_phys_alloc_freelist_pages(int domain, int freelist, int pool, int order)
797 {
798 struct vm_freelist *alt, *fl;
799 vm_page_t m;
800 int oind, pind, flind;
801
802 KASSERT(domain >= 0 && domain < vm_ndomains,
803 ("vm_phys_alloc_freelist_pages: domain %d is out of range",
804 domain));
805 KASSERT(freelist < VM_NFREELIST,
806 ("vm_phys_alloc_freelist_pages: freelist %d is out of range",
807 freelist));
808 KASSERT(pool < VM_NFREEPOOL,
809 ("vm_phys_alloc_freelist_pages: pool %d is out of range", pool));
810 KASSERT(order < VM_NFREEORDER,
811 ("vm_phys_alloc_freelist_pages: order %d is out of range", order));
812
813 flind = vm_freelist_to_flind[freelist];
814 /* Check if freelist is present */
815 if (flind < 0)
816 return (NULL);
817
818 vm_domain_free_assert_locked(VM_DOMAIN(domain));
819 fl = &vm_phys_free_queues[domain][flind][pool][0];
820 for (oind = order; oind < VM_NFREEORDER; oind++) {
821 m = TAILQ_FIRST(&fl[oind].pl);
822 if (m != NULL) {
823 vm_freelist_rem(fl, m, oind);
824 /* The order [order, oind) queues are empty. */
825 vm_phys_split_pages(m, oind, fl, order, 1);
826 return (m);
827 }
828 }
829
830 /*
831 * The given pool was empty. Find the largest
832 * contiguous, power-of-two-sized set of pages in any
833 * pool. Transfer these pages to the given pool, and
834 * use them to satisfy the allocation.
835 */
836 for (oind = VM_NFREEORDER - 1; oind >= order; oind--) {
837 for (pind = 0; pind < VM_NFREEPOOL; pind++) {
838 alt = &vm_phys_free_queues[domain][flind][pind][0];
839 m = TAILQ_FIRST(&alt[oind].pl);
840 if (m != NULL) {
841 vm_freelist_rem(alt, m, oind);
842 vm_phys_set_pool(pool, m, oind);
843 /* The order [order, oind) queues are empty. */
844 vm_phys_split_pages(m, oind, fl, order, 1);
845 return (m);
846 }
847 }
848 }
849 return (NULL);
850 }
851
852 /*
853 * Find the vm_page corresponding to the given physical address.
854 */
855 vm_page_t
856 vm_phys_paddr_to_vm_page(vm_paddr_t pa)
857 {
858 struct vm_phys_seg *seg;
859 int segind;
860
861 for (segind = 0; segind < vm_phys_nsegs; segind++) {
862 seg = &vm_phys_segs[segind];
863 if (pa >= seg->start && pa < seg->end)
864 return (&seg->first_page[atop(pa - seg->start)]);
865 }
866 return (NULL);
867 }
868
869 vm_page_t
870 vm_phys_fictitious_to_vm_page(vm_paddr_t pa)
871 {
872 struct vm_phys_fictitious_seg tmp, *seg;
873 vm_page_t m;
874
875 m = NULL;
876 tmp.start = pa;
877 tmp.end = 0;
878
879 rw_rlock(&vm_phys_fictitious_reg_lock);
880 seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
881 rw_runlock(&vm_phys_fictitious_reg_lock);
882 if (seg == NULL)
883 return (NULL);
884
885 m = &seg->first_page[atop(pa - seg->start)];
886 KASSERT((m->flags & PG_FICTITIOUS) != 0, ("%p not fictitious", m));
887
888 return (m);
889 }
890
891 static inline void
892 vm_phys_fictitious_init_range(vm_page_t range, vm_paddr_t start,
893 long page_count, vm_memattr_t memattr)
894 {
895 long i;
896
897 bzero(range, page_count * sizeof(*range));
898 for (i = 0; i < page_count; i++) {
899 vm_page_initfake(&range[i], start + PAGE_SIZE * i, memattr);
900 range[i].oflags &= ~VPO_UNMANAGED;
901 range[i].busy_lock = VPB_UNBUSIED;
902 }
903 }
904
905 int
906 vm_phys_fictitious_reg_range(vm_paddr_t start, vm_paddr_t end,
907 vm_memattr_t memattr)
908 {
909 struct vm_phys_fictitious_seg *seg;
910 vm_page_t fp;
911 long page_count;
912 #ifdef VM_PHYSSEG_DENSE
913 long pi, pe;
914 long dpage_count;
915 #endif
916
917 KASSERT(start < end,
918 ("Start of segment isn't less than end (start: %jx end: %jx)",
919 (uintmax_t)start, (uintmax_t)end));
920
921 page_count = (end - start) / PAGE_SIZE;
922
923 #ifdef VM_PHYSSEG_DENSE
924 pi = atop(start);
925 pe = atop(end);
926 if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
927 fp = &vm_page_array[pi - first_page];
928 if ((pe - first_page) > vm_page_array_size) {
929 /*
930 * We have a segment that starts inside
931 * of vm_page_array, but ends outside of it.
932 *
933 * Use vm_page_array pages for those that are
934 * inside of the vm_page_array range, and
935 * allocate the remaining ones.
936 */
937 dpage_count = vm_page_array_size - (pi - first_page);
938 vm_phys_fictitious_init_range(fp, start, dpage_count,
939 memattr);
940 page_count -= dpage_count;
941 start += ptoa(dpage_count);
942 goto alloc;
943 }
944 /*
945 * We can allocate the full range from vm_page_array,
946 * so there's no need to register the range in the tree.
947 */
948 vm_phys_fictitious_init_range(fp, start, page_count, memattr);
949 return (0);
950 } else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
951 /*
952 * We have a segment that ends inside of vm_page_array,
953 * but starts outside of it.
954 */
955 fp = &vm_page_array[0];
956 dpage_count = pe - first_page;
957 vm_phys_fictitious_init_range(fp, ptoa(first_page), dpage_count,
958 memattr);
959 end -= ptoa(dpage_count);
960 page_count -= dpage_count;
961 goto alloc;
962 } else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
963 /*
964 * Trying to register a fictitious range that expands before
965 * and after vm_page_array.
966 */
967 return (EINVAL);
968 } else {
969 alloc:
970 #endif
971 fp = malloc(page_count * sizeof(struct vm_page), M_FICT_PAGES,
972 M_WAITOK);
973 #ifdef VM_PHYSSEG_DENSE
974 }
975 #endif
976 vm_phys_fictitious_init_range(fp, start, page_count, memattr);
977
978 seg = malloc(sizeof(*seg), M_FICT_PAGES, M_WAITOK | M_ZERO);
979 seg->start = start;
980 seg->end = end;
981 seg->first_page = fp;
982
983 rw_wlock(&vm_phys_fictitious_reg_lock);
984 RB_INSERT(fict_tree, &vm_phys_fictitious_tree, seg);
985 rw_wunlock(&vm_phys_fictitious_reg_lock);
986
987 return (0);
988 }
989
990 void
991 vm_phys_fictitious_unreg_range(vm_paddr_t start, vm_paddr_t end)
992 {
993 struct vm_phys_fictitious_seg *seg, tmp;
994 #ifdef VM_PHYSSEG_DENSE
995 long pi, pe;
996 #endif
997
998 KASSERT(start < end,
999 ("Start of segment isn't less than end (start: %jx end: %jx)",
1000 (uintmax_t)start, (uintmax_t)end));
1001
1002 #ifdef VM_PHYSSEG_DENSE
1003 pi = atop(start);
1004 pe = atop(end);
1005 if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
1006 if ((pe - first_page) <= vm_page_array_size) {
1007 /*
1008 * This segment was allocated using vm_page_array
1009 * only, there's nothing to do since those pages
1010 * were never added to the tree.
1011 */
1012 return;
1013 }
1014 /*
1015 * We have a segment that starts inside
1016 * of vm_page_array, but ends outside of it.
1017 *
1018 * Calculate how many pages were added to the
1019 * tree and free them.
1020 */
1021 start = ptoa(first_page + vm_page_array_size);
1022 } else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
1023 /*
1024 * We have a segment that ends inside of vm_page_array,
1025 * but starts outside of it.
1026 */
1027 end = ptoa(first_page);
1028 } else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
1029 /* Since it's not possible to register such a range, panic. */
1030 panic(
1031 "Unregistering not registered fictitious range [%#jx:%#jx]",
1032 (uintmax_t)start, (uintmax_t)end);
1033 }
1034 #endif
1035 tmp.start = start;
1036 tmp.end = 0;
1037
1038 rw_wlock(&vm_phys_fictitious_reg_lock);
1039 seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
1040 if (seg->start != start || seg->end != end) {
1041 rw_wunlock(&vm_phys_fictitious_reg_lock);
1042 panic(
1043 "Unregistering not registered fictitious range [%#jx:%#jx]",
1044 (uintmax_t)start, (uintmax_t)end);
1045 }
1046 RB_REMOVE(fict_tree, &vm_phys_fictitious_tree, seg);
1047 rw_wunlock(&vm_phys_fictitious_reg_lock);
1048 free(seg->first_page, M_FICT_PAGES);
1049 free(seg, M_FICT_PAGES);
1050 }
1051
1052 /*
1053 * Free a contiguous, power of two-sized set of physical pages.
1054 *
1055 * The free page queues must be locked.
1056 */
1057 void
1058 vm_phys_free_pages(vm_page_t m, int order)
1059 {
1060 struct vm_freelist *fl;
1061 struct vm_phys_seg *seg;
1062 vm_paddr_t pa;
1063 vm_page_t m_buddy;
1064
1065 KASSERT(m->order == VM_NFREEORDER,
1066 ("vm_phys_free_pages: page %p has unexpected order %d",
1067 m, m->order));
1068 KASSERT(m->pool < VM_NFREEPOOL,
1069 ("vm_phys_free_pages: page %p has unexpected pool %d",
1070 m, m->pool));
1071 KASSERT(order < VM_NFREEORDER,
1072 ("vm_phys_free_pages: order %d is out of range", order));
1073 seg = &vm_phys_segs[m->segind];
1074 vm_domain_free_assert_locked(VM_DOMAIN(seg->domain));
1075 if (order < VM_NFREEORDER - 1) {
1076 pa = VM_PAGE_TO_PHYS(m);
1077 do {
1078 pa ^= ((vm_paddr_t)1 << (PAGE_SHIFT + order));
1079 if (pa < seg->start || pa >= seg->end)
1080 break;
1081 m_buddy = &seg->first_page[atop(pa - seg->start)];
1082 if (m_buddy->order != order)
1083 break;
1084 fl = (*seg->free_queues)[m_buddy->pool];
1085 vm_freelist_rem(fl, m_buddy, order);
1086 if (m_buddy->pool != m->pool)
1087 vm_phys_set_pool(m->pool, m_buddy, order);
1088 order++;
1089 pa &= ~(((vm_paddr_t)1 << (PAGE_SHIFT + order)) - 1);
1090 m = &seg->first_page[atop(pa - seg->start)];
1091 } while (order < VM_NFREEORDER - 1);
1092 }
1093 fl = (*seg->free_queues)[m->pool];
1094 vm_freelist_add(fl, m, order, 1);
1095 }
1096
1097 /*
1098 * Free a contiguous, arbitrarily sized set of physical pages.
1099 *
1100 * The free page queues must be locked.
1101 */
1102 void
1103 vm_phys_free_contig(vm_page_t m, u_long npages)
1104 {
1105 u_int n;
1106 int order;
1107
1108 /*
1109 * Avoid unnecessary coalescing by freeing the pages in the largest
1110 * possible power-of-two-sized subsets.
1111 */
1112 vm_domain_free_assert_locked(vm_pagequeue_domain(m));
1113 for (;; npages -= n) {
1114 /*
1115 * Unsigned "min" is used here so that "order" is assigned
1116 * "VM_NFREEORDER - 1" when "m"'s physical address is zero
1117 * or the low-order bits of its physical address are zero
1118 * because the size of a physical address exceeds the size of
1119 * a long.
1120 */
1121 order = min(ffsl(VM_PAGE_TO_PHYS(m) >> PAGE_SHIFT) - 1,
1122 VM_NFREEORDER - 1);
1123 n = 1 << order;
1124 if (npages < n)
1125 break;
1126 vm_phys_free_pages(m, order);
1127 m += n;
1128 }
1129 /* The residual "npages" is less than "1 << (VM_NFREEORDER - 1)". */
1130 for (; npages > 0; npages -= n) {
1131 order = flsl(npages) - 1;
1132 n = 1 << order;
1133 vm_phys_free_pages(m, order);
1134 m += n;
1135 }
1136 }
1137
1138 /*
1139 * Scan physical memory between the specified addresses "low" and "high" for a
1140 * run of contiguous physical pages that satisfy the specified conditions, and
1141 * return the lowest page in the run. The specified "alignment" determines
1142 * the alignment of the lowest physical page in the run. If the specified
1143 * "boundary" is non-zero, then the run of physical pages cannot span a
1144 * physical address that is a multiple of "boundary".
1145 *
1146 * "npages" must be greater than zero. Both "alignment" and "boundary" must
1147 * be a power of two.
1148 */
1149 vm_page_t
1150 vm_phys_scan_contig(int domain, u_long npages, vm_paddr_t low, vm_paddr_t high,
1151 u_long alignment, vm_paddr_t boundary, int options)
1152 {
1153 vm_paddr_t pa_end;
1154 vm_page_t m_end, m_run, m_start;
1155 struct vm_phys_seg *seg;
1156 int segind;
1157
1158 KASSERT(npages > 0, ("npages is 0"));
1159 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1160 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1161 if (low >= high)
1162 return (NULL);
1163 for (segind = 0; segind < vm_phys_nsegs; segind++) {
1164 seg = &vm_phys_segs[segind];
1165 if (seg->domain != domain)
1166 continue;
1167 if (seg->start >= high)
1168 break;
1169 if (low >= seg->end)
1170 continue;
1171 if (low <= seg->start)
1172 m_start = seg->first_page;
1173 else
1174 m_start = &seg->first_page[atop(low - seg->start)];
1175 if (high < seg->end)
1176 pa_end = high;
1177 else
1178 pa_end = seg->end;
1179 if (pa_end - VM_PAGE_TO_PHYS(m_start) < ptoa(npages))
1180 continue;
1181 m_end = &seg->first_page[atop(pa_end - seg->start)];
1182 m_run = vm_page_scan_contig(npages, m_start, m_end,
1183 alignment, boundary, options);
1184 if (m_run != NULL)
1185 return (m_run);
1186 }
1187 return (NULL);
1188 }
1189
1190 /*
1191 * Set the pool for a contiguous, power of two-sized set of physical pages.
1192 */
1193 void
1194 vm_phys_set_pool(int pool, vm_page_t m, int order)
1195 {
1196 vm_page_t m_tmp;
1197
1198 for (m_tmp = m; m_tmp < &m[1 << order]; m_tmp++)
1199 m_tmp->pool = pool;
1200 }
1201
1202 /*
1203 * Search for the given physical page "m" in the free lists. If the search
1204 * succeeds, remove "m" from the free lists and return TRUE. Otherwise, return
1205 * FALSE, indicating that "m" is not in the free lists.
1206 *
1207 * The free page queues must be locked.
1208 */
1209 boolean_t
1210 vm_phys_unfree_page(vm_page_t m)
1211 {
1212 struct vm_freelist *fl;
1213 struct vm_phys_seg *seg;
1214 vm_paddr_t pa, pa_half;
1215 vm_page_t m_set, m_tmp;
1216 int order;
1217
1218 /*
1219 * First, find the contiguous, power of two-sized set of free
1220 * physical pages containing the given physical page "m" and
1221 * assign it to "m_set".
1222 */
1223 seg = &vm_phys_segs[m->segind];
1224 vm_domain_free_assert_locked(VM_DOMAIN(seg->domain));
1225 for (m_set = m, order = 0; m_set->order == VM_NFREEORDER &&
1226 order < VM_NFREEORDER - 1; ) {
1227 order++;
1228 pa = m->phys_addr & (~(vm_paddr_t)0 << (PAGE_SHIFT + order));
1229 if (pa >= seg->start)
1230 m_set = &seg->first_page[atop(pa - seg->start)];
1231 else
1232 return (FALSE);
1233 }
1234 if (m_set->order < order)
1235 return (FALSE);
1236 if (m_set->order == VM_NFREEORDER)
1237 return (FALSE);
1238 KASSERT(m_set->order < VM_NFREEORDER,
1239 ("vm_phys_unfree_page: page %p has unexpected order %d",
1240 m_set, m_set->order));
1241
1242 /*
1243 * Next, remove "m_set" from the free lists. Finally, extract
1244 * "m" from "m_set" using an iterative algorithm: While "m_set"
1245 * is larger than a page, shrink "m_set" by returning the half
1246 * of "m_set" that does not contain "m" to the free lists.
1247 */
1248 fl = (*seg->free_queues)[m_set->pool];
1249 order = m_set->order;
1250 vm_freelist_rem(fl, m_set, order);
1251 while (order > 0) {
1252 order--;
1253 pa_half = m_set->phys_addr ^ (1 << (PAGE_SHIFT + order));
1254 if (m->phys_addr < pa_half)
1255 m_tmp = &seg->first_page[atop(pa_half - seg->start)];
1256 else {
1257 m_tmp = m_set;
1258 m_set = &seg->first_page[atop(pa_half - seg->start)];
1259 }
1260 vm_freelist_add(fl, m_tmp, order, 0);
1261 }
1262 KASSERT(m_set == m, ("vm_phys_unfree_page: fatal inconsistency"));
1263 return (TRUE);
1264 }
1265
1266 /*
1267 * Allocate a contiguous set of physical pages of the given size
1268 * "npages" from the free lists. All of the physical pages must be at
1269 * or above the given physical address "low" and below the given
1270 * physical address "high". The given value "alignment" determines the
1271 * alignment of the first physical page in the set. If the given value
1272 * "boundary" is non-zero, then the set of physical pages cannot cross
1273 * any physical address boundary that is a multiple of that value. Both
1274 * "alignment" and "boundary" must be a power of two.
1275 */
1276 vm_page_t
1277 vm_phys_alloc_contig(int domain, u_long npages, vm_paddr_t low, vm_paddr_t high,
1278 u_long alignment, vm_paddr_t boundary)
1279 {
1280 vm_paddr_t pa_end, pa_start;
1281 vm_page_t m_run;
1282 struct vm_phys_seg *seg;
1283 int segind;
1284
1285 KASSERT(npages > 0, ("npages is 0"));
1286 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1287 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1288 vm_domain_free_assert_locked(VM_DOMAIN(domain));
1289 if (low >= high)
1290 return (NULL);
1291 m_run = NULL;
1292 for (segind = vm_phys_nsegs - 1; segind >= 0; segind--) {
1293 seg = &vm_phys_segs[segind];
1294 if (seg->start >= high || seg->domain != domain)
1295 continue;
1296 if (low >= seg->end)
1297 break;
1298 if (low <= seg->start)
1299 pa_start = seg->start;
1300 else
1301 pa_start = low;
1302 if (high < seg->end)
1303 pa_end = high;
1304 else
1305 pa_end = seg->end;
1306 if (pa_end - pa_start < ptoa(npages))
1307 continue;
1308 m_run = vm_phys_alloc_seg_contig(seg, npages, low, high,
1309 alignment, boundary);
1310 if (m_run != NULL)
1311 break;
1312 }
1313 return (m_run);
1314 }
1315
1316 /*
1317 * Allocate a run of contiguous physical pages from the free list for the
1318 * specified segment.
1319 */
1320 static vm_page_t
1321 vm_phys_alloc_seg_contig(struct vm_phys_seg *seg, u_long npages,
1322 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
1323 {
1324 struct vm_freelist *fl;
1325 vm_paddr_t pa, pa_end, size;
1326 vm_page_t m, m_ret;
1327 u_long npages_end;
1328 int oind, order, pind;
1329
1330 KASSERT(npages > 0, ("npages is 0"));
1331 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
1332 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
1333 vm_domain_free_assert_locked(VM_DOMAIN(seg->domain));
1334 /* Compute the queue that is the best fit for npages. */
1335 order = flsl(npages - 1);
1336 /* Search for a run satisfying the specified conditions. */
1337 size = npages << PAGE_SHIFT;
1338 for (oind = min(order, VM_NFREEORDER - 1); oind < VM_NFREEORDER;
1339 oind++) {
1340 for (pind = 0; pind < VM_NFREEPOOL; pind++) {
1341 fl = (*seg->free_queues)[pind];
1342 TAILQ_FOREACH(m_ret, &fl[oind].pl, listq) {
1343 /*
1344 * Is the size of this allocation request
1345 * larger than the largest block size?
1346 */
1347 if (order >= VM_NFREEORDER) {
1348 /*
1349 * Determine if a sufficient number of
1350 * subsequent blocks to satisfy the
1351 * allocation request are free.
1352 */
1353 pa = VM_PAGE_TO_PHYS(m_ret);
1354 pa_end = pa + size;
1355 if (pa_end < pa)
1356 continue;
1357 for (;;) {
1358 pa += 1 << (PAGE_SHIFT +
1359 VM_NFREEORDER - 1);
1360 if (pa >= pa_end ||
1361 pa < seg->start ||
1362 pa >= seg->end)
1363 break;
1364 m = &seg->first_page[atop(pa -
1365 seg->start)];
1366 if (m->order != VM_NFREEORDER -
1367 1)
1368 break;
1369 }
1370 /* If not, go to the next block. */
1371 if (pa < pa_end)
1372 continue;
1373 }
1374
1375 /*
1376 * Determine if the blocks are within the
1377 * given range, satisfy the given alignment,
1378 * and do not cross the given boundary.
1379 */
1380 pa = VM_PAGE_TO_PHYS(m_ret);
1381 pa_end = pa + size;
1382 if (pa >= low && pa_end <= high &&
1383 (pa & (alignment - 1)) == 0 &&
1384 rounddown2(pa ^ (pa_end - 1), boundary) == 0)
1385 goto done;
1386 }
1387 }
1388 }
1389 return (NULL);
1390 done:
1391 for (m = m_ret; m < &m_ret[npages]; m = &m[1 << oind]) {
1392 fl = (*seg->free_queues)[m->pool];
1393 vm_freelist_rem(fl, m, oind);
1394 if (m->pool != VM_FREEPOOL_DEFAULT)
1395 vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, oind);
1396 }
1397 /* Return excess pages to the free lists. */
1398 npages_end = roundup2(npages, 1 << oind);
1399 if (npages < npages_end) {
1400 fl = (*seg->free_queues)[VM_FREEPOOL_DEFAULT];
1401 vm_phys_enq_range(&m_ret[npages], npages_end - npages, fl, 0);
1402 }
1403 return (m_ret);
1404 }
1405
1406 #ifdef DDB
1407 /*
1408 * Show the number of physical pages in each of the free lists.
1409 */
1410 DB_SHOW_COMMAND(freepages, db_show_freepages)
1411 {
1412 struct vm_freelist *fl;
1413 int flind, oind, pind, dom;
1414
1415 for (dom = 0; dom < vm_ndomains; dom++) {
1416 db_printf("DOMAIN: %d\n", dom);
1417 for (flind = 0; flind < vm_nfreelists; flind++) {
1418 db_printf("FREE LIST %d:\n"
1419 "\n ORDER (SIZE) | NUMBER"
1420 "\n ", flind);
1421 for (pind = 0; pind < VM_NFREEPOOL; pind++)
1422 db_printf(" | POOL %d", pind);
1423 db_printf("\n-- ");
1424 for (pind = 0; pind < VM_NFREEPOOL; pind++)
1425 db_printf("-- -- ");
1426 db_printf("--\n");
1427 for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
1428 db_printf(" %2.2d (%6.6dK)", oind,
1429 1 << (PAGE_SHIFT - 10 + oind));
1430 for (pind = 0; pind < VM_NFREEPOOL; pind++) {
1431 fl = vm_phys_free_queues[dom][flind][pind];
1432 db_printf(" | %6.6d", fl[oind].lcnt);
1433 }
1434 db_printf("\n");
1435 }
1436 db_printf("\n");
1437 }
1438 db_printf("\n");
1439 }
1440 }
1441 #endif
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