xref: /netbsd-src/sys/kern/subr_vmem.c (revision 5b239d0be1d6682ecf6030411841b40cc91e8b34)
1 /*	$NetBSD: subr_vmem.c,v 1.20 2006/11/09 10:08:53 yamt Exp $	*/
2 
3 /*-
4  * Copyright (c)2006 YAMAMOTO Takashi,
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * reference:
31  * -	Magazines and Vmem: Extending the Slab Allocator
32  *	to Many CPUs and Arbitrary Resources
33  *	http://www.usenix.org/event/usenix01/bonwick.html
34  *
35  * todo:
36  * -	decide how to import segments for vmem_xalloc.
37  * -	don't rely on malloc(9).
38  */
39 
40 #include <sys/cdefs.h>
41 __KERNEL_RCSID(0, "$NetBSD: subr_vmem.c,v 1.20 2006/11/09 10:08:53 yamt Exp $");
42 
43 #define	VMEM_DEBUG
44 #if defined(_KERNEL)
45 #define	QCACHE
46 #endif /* defined(_KERNEL) */
47 
48 #include <sys/param.h>
49 #include <sys/hash.h>
50 #include <sys/queue.h>
51 
52 #if defined(_KERNEL)
53 #include <sys/systm.h>
54 #include <sys/lock.h>
55 #include <sys/malloc.h>
56 #include <sys/once.h>
57 #include <sys/pool.h>
58 #include <sys/proc.h>
59 #include <sys/vmem.h>
60 #else /* defined(_KERNEL) */
61 #include "../sys/vmem.h"
62 #endif /* defined(_KERNEL) */
63 
64 #if defined(_KERNEL)
65 #define	SIMPLELOCK_DECL(name)	struct simplelock name
66 #else /* defined(_KERNEL) */
67 #include <errno.h>
68 #include <assert.h>
69 #include <stdlib.h>
70 
71 #define	KASSERT(a)		assert(a)
72 #define	SIMPLELOCK_DECL(name)	/* nothing */
73 #define	LOCK_ASSERT(a)		/* nothing */
74 #define	simple_lock_init(a)	/* nothing */
75 #define	simple_lock(a)		/* nothing */
76 #define	simple_unlock(a)	/* nothing */
77 #define	ASSERT_SLEEPABLE(lk, msg) /* nothing */
78 #endif /* defined(_KERNEL) */
79 
80 struct vmem;
81 struct vmem_btag;
82 
83 #if defined(VMEM_DEBUG)
84 void vmem_dump(const vmem_t *);
85 #endif /* defined(VMEM_DEBUG) */
86 
87 #define	VMEM_MAXORDER		(sizeof(vmem_size_t) * CHAR_BIT)
88 #define	VMEM_HASHSIZE_INIT	4096	/* XXX */
89 
90 #define	VM_FITMASK	(VM_BESTFIT | VM_INSTANTFIT)
91 
92 CIRCLEQ_HEAD(vmem_seglist, vmem_btag);
93 LIST_HEAD(vmem_freelist, vmem_btag);
94 LIST_HEAD(vmem_hashlist, vmem_btag);
95 
96 #if defined(QCACHE)
97 #define	VMEM_QCACHE_IDX_MAX	32
98 
99 #define	QC_NAME_MAX	16
100 
101 struct qcache {
102 	struct pool qc_pool;
103 	struct pool_cache qc_cache;
104 	vmem_t *qc_vmem;
105 	char qc_name[QC_NAME_MAX];
106 };
107 typedef struct qcache qcache_t;
108 #define	QC_POOL_TO_QCACHE(pool)	((qcache_t *)(pool))
109 #endif /* defined(QCACHE) */
110 
111 /* vmem arena */
112 struct vmem {
113 	SIMPLELOCK_DECL(vm_lock);
114 	vmem_addr_t (*vm_allocfn)(vmem_t *, vmem_size_t, vmem_size_t *,
115 	    vm_flag_t);
116 	void (*vm_freefn)(vmem_t *, vmem_addr_t, vmem_size_t);
117 	vmem_t *vm_source;
118 	struct vmem_seglist vm_seglist;
119 	struct vmem_freelist vm_freelist[VMEM_MAXORDER];
120 	size_t vm_hashsize;
121 	size_t vm_nbusytag;
122 	struct vmem_hashlist *vm_hashlist;
123 	size_t vm_quantum_mask;
124 	int vm_quantum_shift;
125 	const char *vm_name;
126 
127 #if defined(QCACHE)
128 	/* quantum cache */
129 	size_t vm_qcache_max;
130 	struct pool_allocator vm_qcache_allocator;
131 	qcache_t vm_qcache[VMEM_QCACHE_IDX_MAX];
132 #endif /* defined(QCACHE) */
133 };
134 
135 #define	VMEM_LOCK(vm)	simple_lock(&vm->vm_lock)
136 #define	VMEM_UNLOCK(vm)	simple_unlock(&vm->vm_lock)
137 #define	VMEM_LOCK_INIT(vm)	simple_lock_init(&vm->vm_lock);
138 #define	VMEM_ASSERT_LOCKED(vm) \
139 	LOCK_ASSERT(simple_lock_held(&vm->vm_lock))
140 #define	VMEM_ASSERT_UNLOCKED(vm) \
141 	LOCK_ASSERT(!simple_lock_held(&vm->vm_lock))
142 
143 /* boundary tag */
144 struct vmem_btag {
145 	CIRCLEQ_ENTRY(vmem_btag) bt_seglist;
146 	union {
147 		LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */
148 		LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */
149 	} bt_u;
150 #define	bt_hashlist	bt_u.u_hashlist
151 #define	bt_freelist	bt_u.u_freelist
152 	vmem_addr_t bt_start;
153 	vmem_size_t bt_size;
154 	int bt_type;
155 };
156 
157 #define	BT_TYPE_SPAN		1
158 #define	BT_TYPE_SPAN_STATIC	2
159 #define	BT_TYPE_FREE		3
160 #define	BT_TYPE_BUSY		4
161 #define	BT_ISSPAN_P(bt)	((bt)->bt_type <= BT_TYPE_SPAN_STATIC)
162 
163 #define	BT_END(bt)	((bt)->bt_start + (bt)->bt_size)
164 
165 typedef struct vmem_btag bt_t;
166 
167 /* ---- misc */
168 
169 #define	VMEM_ALIGNUP(addr, align) \
170 	(-(-(addr) & -(align)))
171 #define	VMEM_CROSS_P(addr1, addr2, boundary) \
172 	((((addr1) ^ (addr2)) & -(boundary)) != 0)
173 
174 #define	ORDER2SIZE(order)	((vmem_size_t)1 << (order))
175 
176 static int
177 calc_order(vmem_size_t size)
178 {
179 	vmem_size_t target;
180 	int i;
181 
182 	KASSERT(size != 0);
183 
184 	i = 0;
185 	target = size >> 1;
186 	while (ORDER2SIZE(i) <= target) {
187 		i++;
188 	}
189 
190 	KASSERT(ORDER2SIZE(i) <= size);
191 	KASSERT(size < ORDER2SIZE(i + 1) || ORDER2SIZE(i + 1) < ORDER2SIZE(i));
192 
193 	return i;
194 }
195 
196 #if defined(_KERNEL)
197 static MALLOC_DEFINE(M_VMEM, "vmem", "vmem");
198 #endif /* defined(_KERNEL) */
199 
200 static void *
201 xmalloc(size_t sz, vm_flag_t flags)
202 {
203 
204 #if defined(_KERNEL)
205 	return malloc(sz, M_VMEM,
206 	    M_CANFAIL | ((flags & VM_SLEEP) ? M_WAITOK : M_NOWAIT));
207 #else /* defined(_KERNEL) */
208 	return malloc(sz);
209 #endif /* defined(_KERNEL) */
210 }
211 
212 static void
213 xfree(void *p)
214 {
215 
216 #if defined(_KERNEL)
217 	return free(p, M_VMEM);
218 #else /* defined(_KERNEL) */
219 	return free(p);
220 #endif /* defined(_KERNEL) */
221 }
222 
223 /* ---- boundary tag */
224 
225 #if defined(_KERNEL)
226 static struct pool_cache bt_poolcache;
227 static POOL_INIT(bt_pool, sizeof(bt_t), 0, 0, 0, "vmembtpl", NULL);
228 #endif /* defined(_KERNEL) */
229 
230 static bt_t *
231 bt_alloc(vmem_t *vm, vm_flag_t flags)
232 {
233 	bt_t *bt;
234 
235 #if defined(_KERNEL)
236 	/* XXX bootstrap */
237 	bt = pool_cache_get(&bt_poolcache,
238 	    (flags & VM_SLEEP) != 0 ? PR_WAITOK : PR_NOWAIT);
239 #else /* defined(_KERNEL) */
240 	bt = malloc(sizeof *bt);
241 #endif /* defined(_KERNEL) */
242 
243 	return bt;
244 }
245 
246 static void
247 bt_free(vmem_t *vm, bt_t *bt)
248 {
249 
250 #if defined(_KERNEL)
251 	/* XXX bootstrap */
252 	pool_cache_put(&bt_poolcache, bt);
253 #else /* defined(_KERNEL) */
254 	free(bt);
255 #endif /* defined(_KERNEL) */
256 }
257 
258 /*
259  * freelist[0] ... [1, 1]
260  * freelist[1] ... [2, 3]
261  * freelist[2] ... [4, 7]
262  * freelist[3] ... [8, 15]
263  *  :
264  * freelist[n] ... [(1 << n), (1 << (n + 1)) - 1]
265  *  :
266  */
267 
268 static struct vmem_freelist *
269 bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
270 {
271 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
272 	int idx;
273 
274 	KASSERT((size & vm->vm_quantum_mask) == 0);
275 	KASSERT(size != 0);
276 
277 	idx = calc_order(qsize);
278 	KASSERT(idx >= 0);
279 	KASSERT(idx < VMEM_MAXORDER);
280 
281 	return &vm->vm_freelist[idx];
282 }
283 
284 static struct vmem_freelist *
285 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, vm_flag_t strat)
286 {
287 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
288 	int idx;
289 
290 	KASSERT((size & vm->vm_quantum_mask) == 0);
291 	KASSERT(size != 0);
292 
293 	idx = calc_order(qsize);
294 	if (strat == VM_INSTANTFIT && ORDER2SIZE(idx) != qsize) {
295 		idx++;
296 		/* check too large request? */
297 	}
298 	KASSERT(idx >= 0);
299 	KASSERT(idx < VMEM_MAXORDER);
300 
301 	return &vm->vm_freelist[idx];
302 }
303 
304 /* ---- boundary tag hash */
305 
306 static struct vmem_hashlist *
307 bt_hashhead(vmem_t *vm, vmem_addr_t addr)
308 {
309 	struct vmem_hashlist *list;
310 	unsigned int hash;
311 
312 	hash = hash32_buf(&addr, sizeof(addr), HASH32_BUF_INIT);
313 	list = &vm->vm_hashlist[hash % vm->vm_hashsize];
314 
315 	return list;
316 }
317 
318 static bt_t *
319 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
320 {
321 	struct vmem_hashlist *list;
322 	bt_t *bt;
323 
324 	list = bt_hashhead(vm, addr);
325 	LIST_FOREACH(bt, list, bt_hashlist) {
326 		if (bt->bt_start == addr) {
327 			break;
328 		}
329 	}
330 
331 	return bt;
332 }
333 
334 static void
335 bt_rembusy(vmem_t *vm, bt_t *bt)
336 {
337 
338 	KASSERT(vm->vm_nbusytag > 0);
339 	vm->vm_nbusytag--;
340 	LIST_REMOVE(bt, bt_hashlist);
341 }
342 
343 static void
344 bt_insbusy(vmem_t *vm, bt_t *bt)
345 {
346 	struct vmem_hashlist *list;
347 
348 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
349 
350 	list = bt_hashhead(vm, bt->bt_start);
351 	LIST_INSERT_HEAD(list, bt, bt_hashlist);
352 	vm->vm_nbusytag++;
353 }
354 
355 /* ---- boundary tag list */
356 
357 static void
358 bt_remseg(vmem_t *vm, bt_t *bt)
359 {
360 
361 	CIRCLEQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
362 }
363 
364 static void
365 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
366 {
367 
368 	CIRCLEQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
369 }
370 
371 static void
372 bt_insseg_tail(vmem_t *vm, bt_t *bt)
373 {
374 
375 	CIRCLEQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
376 }
377 
378 static void
379 bt_remfree(vmem_t *vm, bt_t *bt)
380 {
381 
382 	KASSERT(bt->bt_type == BT_TYPE_FREE);
383 
384 	LIST_REMOVE(bt, bt_freelist);
385 }
386 
387 static void
388 bt_insfree(vmem_t *vm, bt_t *bt)
389 {
390 	struct vmem_freelist *list;
391 
392 	list = bt_freehead_tofree(vm, bt->bt_size);
393 	LIST_INSERT_HEAD(list, bt, bt_freelist);
394 }
395 
396 /* ---- vmem internal functions */
397 
398 #if defined(QCACHE)
399 static inline vm_flag_t
400 prf_to_vmf(int prflags)
401 {
402 	vm_flag_t vmflags;
403 
404 	KASSERT((prflags & ~(PR_LIMITFAIL | PR_WAITOK | PR_NOWAIT)) == 0);
405 	if ((prflags & PR_WAITOK) != 0) {
406 		vmflags = VM_SLEEP;
407 	} else {
408 		vmflags = VM_NOSLEEP;
409 	}
410 	return vmflags;
411 }
412 
413 static inline int
414 vmf_to_prf(vm_flag_t vmflags)
415 {
416 	int prflags;
417 
418 	if ((vmflags & VM_SLEEP) != 0) {
419 		prflags = PR_WAITOK;
420 	} else {
421 		prflags = PR_NOWAIT;
422 	}
423 	return prflags;
424 }
425 
426 static size_t
427 qc_poolpage_size(size_t qcache_max)
428 {
429 	int i;
430 
431 	for (i = 0; ORDER2SIZE(i) <= qcache_max * 3; i++) {
432 		/* nothing */
433 	}
434 	return ORDER2SIZE(i);
435 }
436 
437 static void *
438 qc_poolpage_alloc(struct pool *pool, int prflags)
439 {
440 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
441 	vmem_t *vm = qc->qc_vmem;
442 
443 	return (void *)vmem_alloc(vm, pool->pr_alloc->pa_pagesz,
444 	    prf_to_vmf(prflags) | VM_INSTANTFIT);
445 }
446 
447 static void
448 qc_poolpage_free(struct pool *pool, void *addr)
449 {
450 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
451 	vmem_t *vm = qc->qc_vmem;
452 
453 	vmem_free(vm, (vmem_addr_t)addr, pool->pr_alloc->pa_pagesz);
454 }
455 
456 static void
457 qc_init(vmem_t *vm, size_t qcache_max)
458 {
459 	struct pool_allocator *pa;
460 	int qcache_idx_max;
461 	int i;
462 
463 	KASSERT((qcache_max & vm->vm_quantum_mask) == 0);
464 	if (qcache_max > (VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift)) {
465 		qcache_max = VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift;
466 	}
467 	vm->vm_qcache_max = qcache_max;
468 	pa = &vm->vm_qcache_allocator;
469 	memset(pa, 0, sizeof(*pa));
470 	pa->pa_alloc = qc_poolpage_alloc;
471 	pa->pa_free = qc_poolpage_free;
472 	pa->pa_pagesz = qc_poolpage_size(qcache_max);
473 
474 	qcache_idx_max = qcache_max >> vm->vm_quantum_shift;
475 	for (i = 1; i <= qcache_idx_max; i++) {
476 		qcache_t *qc = &vm->vm_qcache[i - 1];
477 		size_t size = i << vm->vm_quantum_shift;
478 
479 		qc->qc_vmem = vm;
480 		snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu",
481 		    vm->vm_name, size);
482 		pool_init(&qc->qc_pool, size, ORDER2SIZE(vm->vm_quantum_shift),
483 		    0, PR_NOALIGN | PR_NOTOUCH /* XXX */, qc->qc_name, pa);
484 		pool_cache_init(&qc->qc_cache, &qc->qc_pool, NULL, NULL, NULL);
485 	}
486 }
487 
488 static boolean_t
489 qc_reap(vmem_t *vm)
490 {
491 	int i;
492 	int qcache_idx_max;
493 	boolean_t didsomething = FALSE;
494 
495 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
496 	for (i = 1; i <= qcache_idx_max; i++) {
497 		qcache_t *qc = &vm->vm_qcache[i - 1];
498 
499 		if (pool_reclaim(&qc->qc_pool) != 0) {
500 			didsomething = TRUE;
501 		}
502 	}
503 
504 	return didsomething;
505 }
506 #endif /* defined(QCACHE) */
507 
508 #if defined(_KERNEL)
509 static int
510 vmem_init(void)
511 {
512 
513 	pool_cache_init(&bt_poolcache, &bt_pool, NULL, NULL, NULL);
514 	return 0;
515 }
516 #endif /* defined(_KERNEL) */
517 
518 static vmem_addr_t
519 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags,
520     int spanbttype)
521 {
522 	bt_t *btspan;
523 	bt_t *btfree;
524 
525 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
526 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
527 	VMEM_ASSERT_UNLOCKED(vm);
528 
529 	btspan = bt_alloc(vm, flags);
530 	if (btspan == NULL) {
531 		return VMEM_ADDR_NULL;
532 	}
533 	btfree = bt_alloc(vm, flags);
534 	if (btfree == NULL) {
535 		bt_free(vm, btspan);
536 		return VMEM_ADDR_NULL;
537 	}
538 
539 	btspan->bt_type = spanbttype;
540 	btspan->bt_start = addr;
541 	btspan->bt_size = size;
542 
543 	btfree->bt_type = BT_TYPE_FREE;
544 	btfree->bt_start = addr;
545 	btfree->bt_size = size;
546 
547 	VMEM_LOCK(vm);
548 	bt_insseg_tail(vm, btspan);
549 	bt_insseg(vm, btfree, btspan);
550 	bt_insfree(vm, btfree);
551 	VMEM_UNLOCK(vm);
552 
553 	return addr;
554 }
555 
556 static int
557 vmem_import(vmem_t *vm, vmem_size_t size, vm_flag_t flags)
558 {
559 	vmem_addr_t addr;
560 
561 	VMEM_ASSERT_UNLOCKED(vm);
562 
563 	if (vm->vm_allocfn == NULL) {
564 		return EINVAL;
565 	}
566 
567 	addr = (*vm->vm_allocfn)(vm->vm_source, size, &size, flags);
568 	if (addr == VMEM_ADDR_NULL) {
569 		return ENOMEM;
570 	}
571 
572 	if (vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN) == VMEM_ADDR_NULL) {
573 		(*vm->vm_freefn)(vm->vm_source, addr, size);
574 		return ENOMEM;
575 	}
576 
577 	return 0;
578 }
579 
580 static int
581 vmem_rehash(vmem_t *vm, size_t newhashsize, vm_flag_t flags)
582 {
583 	bt_t *bt;
584 	int i;
585 	struct vmem_hashlist *newhashlist;
586 	struct vmem_hashlist *oldhashlist;
587 	size_t oldhashsize;
588 
589 	KASSERT(newhashsize > 0);
590 	VMEM_ASSERT_UNLOCKED(vm);
591 
592 	newhashlist =
593 	    xmalloc(sizeof(struct vmem_hashlist *) * newhashsize, flags);
594 	if (newhashlist == NULL) {
595 		return ENOMEM;
596 	}
597 	for (i = 0; i < newhashsize; i++) {
598 		LIST_INIT(&newhashlist[i]);
599 	}
600 
601 	VMEM_LOCK(vm);
602 	oldhashlist = vm->vm_hashlist;
603 	oldhashsize = vm->vm_hashsize;
604 	vm->vm_hashlist = newhashlist;
605 	vm->vm_hashsize = newhashsize;
606 	if (oldhashlist == NULL) {
607 		VMEM_UNLOCK(vm);
608 		return 0;
609 	}
610 	for (i = 0; i < oldhashsize; i++) {
611 		while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
612 			bt_rembusy(vm, bt); /* XXX */
613 			bt_insbusy(vm, bt);
614 		}
615 	}
616 	VMEM_UNLOCK(vm);
617 
618 	xfree(oldhashlist);
619 
620 	return 0;
621 }
622 
623 /*
624  * vmem_fit: check if a bt can satisfy the given restrictions.
625  */
626 
627 static vmem_addr_t
628 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align, vmem_size_t phase,
629     vmem_size_t nocross, vmem_addr_t minaddr, vmem_addr_t maxaddr)
630 {
631 	vmem_addr_t start;
632 	vmem_addr_t end;
633 
634 	KASSERT(bt->bt_size >= size);
635 
636 	/*
637 	 * XXX assumption: vmem_addr_t and vmem_size_t are
638 	 * unsigned integer of the same size.
639 	 */
640 
641 	start = bt->bt_start;
642 	if (start < minaddr) {
643 		start = minaddr;
644 	}
645 	end = BT_END(bt);
646 	if (end > maxaddr - 1) {
647 		end = maxaddr - 1;
648 	}
649 	if (start >= end) {
650 		return VMEM_ADDR_NULL;
651 	}
652 
653 	start = VMEM_ALIGNUP(start - phase, align) + phase;
654 	if (start < bt->bt_start) {
655 		start += align;
656 	}
657 	if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
658 		KASSERT(align < nocross);
659 		start = VMEM_ALIGNUP(start - phase, nocross) + phase;
660 	}
661 	if (start < end && end - start >= size) {
662 		KASSERT((start & (align - 1)) == phase);
663 		KASSERT(!VMEM_CROSS_P(start, start + size - 1, nocross));
664 		KASSERT(minaddr <= start);
665 		KASSERT(maxaddr == 0 || start + size <= maxaddr);
666 		KASSERT(bt->bt_start <= start);
667 		KASSERT(start + size <= BT_END(bt));
668 		return start;
669 	}
670 	return VMEM_ADDR_NULL;
671 }
672 
673 /* ---- vmem API */
674 
675 /*
676  * vmem_create: create an arena.
677  *
678  * => must not be called from interrupt context.
679  */
680 
681 vmem_t *
682 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
683     vmem_size_t quantum,
684     vmem_addr_t (*allocfn)(vmem_t *, vmem_size_t, vmem_size_t *, vm_flag_t),
685     void (*freefn)(vmem_t *, vmem_addr_t, vmem_size_t),
686     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags)
687 {
688 	vmem_t *vm;
689 	int i;
690 #if defined(_KERNEL)
691 	static ONCE_DECL(control);
692 #endif /* defined(_KERNEL) */
693 
694 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
695 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
696 
697 #if defined(_KERNEL)
698 	if (RUN_ONCE(&control, vmem_init)) {
699 		return NULL;
700 	}
701 #endif /* defined(_KERNEL) */
702 	vm = xmalloc(sizeof(*vm), flags);
703 	if (vm == NULL) {
704 		return NULL;
705 	}
706 
707 	VMEM_LOCK_INIT(vm);
708 	vm->vm_name = name;
709 	vm->vm_quantum_mask = quantum - 1;
710 	vm->vm_quantum_shift = calc_order(quantum);
711 	KASSERT(ORDER2SIZE(vm->vm_quantum_shift) == quantum);
712 	vm->vm_allocfn = allocfn;
713 	vm->vm_freefn = freefn;
714 	vm->vm_source = source;
715 	vm->vm_nbusytag = 0;
716 #if defined(QCACHE)
717 	qc_init(vm, qcache_max);
718 #endif /* defined(QCACHE) */
719 
720 	CIRCLEQ_INIT(&vm->vm_seglist);
721 	for (i = 0; i < VMEM_MAXORDER; i++) {
722 		LIST_INIT(&vm->vm_freelist[i]);
723 	}
724 	vm->vm_hashlist = NULL;
725 	if (vmem_rehash(vm, VMEM_HASHSIZE_INIT, flags)) {
726 		vmem_destroy(vm);
727 		return NULL;
728 	}
729 
730 	if (size != 0) {
731 		if (vmem_add(vm, base, size, flags) == 0) {
732 			vmem_destroy(vm);
733 			return NULL;
734 		}
735 	}
736 
737 	return vm;
738 }
739 
740 void
741 vmem_destroy(vmem_t *vm)
742 {
743 
744 	VMEM_ASSERT_UNLOCKED(vm);
745 
746 	if (vm->vm_hashlist != NULL) {
747 		int i;
748 
749 		for (i = 0; i < vm->vm_hashsize; i++) {
750 			bt_t *bt;
751 
752 			while ((bt = LIST_FIRST(&vm->vm_hashlist[i])) != NULL) {
753 				KASSERT(bt->bt_type == BT_TYPE_SPAN_STATIC);
754 				bt_free(vm, bt);
755 			}
756 		}
757 		xfree(vm->vm_hashlist);
758 	}
759 	xfree(vm);
760 }
761 
762 vmem_size_t
763 vmem_roundup_size(vmem_t *vm, vmem_size_t size)
764 {
765 
766 	return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
767 }
768 
769 /*
770  * vmem_alloc:
771  *
772  * => caller must ensure appropriate spl,
773  *    if the arena can be accessed from interrupt context.
774  */
775 
776 vmem_addr_t
777 vmem_alloc(vmem_t *vm, vmem_size_t size0, vm_flag_t flags)
778 {
779 	const vmem_size_t size __unused = vmem_roundup_size(vm, size0);
780 	const vm_flag_t strat __unused = flags & VM_FITMASK;
781 
782 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
783 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
784 	VMEM_ASSERT_UNLOCKED(vm);
785 
786 	KASSERT(size0 > 0);
787 	KASSERT(size > 0);
788 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
789 	if ((flags & VM_SLEEP) != 0) {
790 		ASSERT_SLEEPABLE(NULL, __func__);
791 	}
792 
793 #if defined(QCACHE)
794 	if (size <= vm->vm_qcache_max) {
795 		int qidx = size >> vm->vm_quantum_shift;
796 		qcache_t *qc = &vm->vm_qcache[qidx - 1];
797 
798 		return (vmem_addr_t)pool_cache_get(&qc->qc_cache,
799 		    vmf_to_prf(flags));
800 	}
801 #endif /* defined(QCACHE) */
802 
803 	return vmem_xalloc(vm, size0, 0, 0, 0, 0, 0, flags);
804 }
805 
806 vmem_addr_t
807 vmem_xalloc(vmem_t *vm, vmem_size_t size0, vmem_size_t align, vmem_size_t phase,
808     vmem_size_t nocross, vmem_addr_t minaddr, vmem_addr_t maxaddr,
809     vm_flag_t flags)
810 {
811 	struct vmem_freelist *list;
812 	struct vmem_freelist *first;
813 	struct vmem_freelist *end;
814 	bt_t *bt;
815 	bt_t *btnew;
816 	bt_t *btnew2;
817 	const vmem_size_t size = vmem_roundup_size(vm, size0);
818 	vm_flag_t strat = flags & VM_FITMASK;
819 	vmem_addr_t start;
820 
821 	KASSERT(size0 > 0);
822 	KASSERT(size > 0);
823 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
824 	if ((flags & VM_SLEEP) != 0) {
825 		ASSERT_SLEEPABLE(NULL, __func__);
826 	}
827 	KASSERT((align & vm->vm_quantum_mask) == 0);
828 	KASSERT((align & (align - 1)) == 0);
829 	KASSERT((phase & vm->vm_quantum_mask) == 0);
830 	KASSERT((nocross & vm->vm_quantum_mask) == 0);
831 	KASSERT((nocross & (nocross - 1)) == 0);
832 	KASSERT((align == 0 && phase == 0) || phase < align);
833 	KASSERT(nocross == 0 || nocross >= size);
834 	KASSERT(maxaddr == 0 || minaddr < maxaddr);
835 	KASSERT(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
836 
837 	if (align == 0) {
838 		align = vm->vm_quantum_mask + 1;
839 	}
840 	btnew = bt_alloc(vm, flags);
841 	if (btnew == NULL) {
842 		return VMEM_ADDR_NULL;
843 	}
844 	btnew2 = bt_alloc(vm, flags); /* XXX not necessary if no restrictions */
845 	if (btnew2 == NULL) {
846 		bt_free(vm, btnew);
847 		return VMEM_ADDR_NULL;
848 	}
849 
850 retry_strat:
851 	first = bt_freehead_toalloc(vm, size, strat);
852 	end = &vm->vm_freelist[VMEM_MAXORDER];
853 retry:
854 	bt = NULL;
855 	VMEM_LOCK(vm);
856 	if (strat == VM_INSTANTFIT) {
857 		for (list = first; list < end; list++) {
858 			bt = LIST_FIRST(list);
859 			if (bt != NULL) {
860 				start = vmem_fit(bt, size, align, phase,
861 				    nocross, minaddr, maxaddr);
862 				if (start != VMEM_ADDR_NULL) {
863 					goto gotit;
864 				}
865 			}
866 		}
867 	} else { /* VM_BESTFIT */
868 		for (list = first; list < end; list++) {
869 			LIST_FOREACH(bt, list, bt_freelist) {
870 				if (bt->bt_size >= size) {
871 					start = vmem_fit(bt, size, align, phase,
872 					    nocross, minaddr, maxaddr);
873 					if (start != VMEM_ADDR_NULL) {
874 						goto gotit;
875 					}
876 				}
877 			}
878 		}
879 	}
880 	VMEM_UNLOCK(vm);
881 #if 1
882 	if (strat == VM_INSTANTFIT) {
883 		strat = VM_BESTFIT;
884 		goto retry_strat;
885 	}
886 #endif
887 	if (align != vm->vm_quantum_mask + 1 || phase != 0 ||
888 	    nocross != 0 || minaddr != 0 || maxaddr != 0) {
889 
890 		/*
891 		 * XXX should try to import a region large enough to
892 		 * satisfy restrictions?
893 		 */
894 
895 		goto fail;
896 	}
897 	if (vmem_import(vm, size, flags) == 0) {
898 		goto retry;
899 	}
900 	/* XXX */
901 fail:
902 	bt_free(vm, btnew);
903 	bt_free(vm, btnew2);
904 	return VMEM_ADDR_NULL;
905 
906 gotit:
907 	KASSERT(bt->bt_type == BT_TYPE_FREE);
908 	KASSERT(bt->bt_size >= size);
909 	bt_remfree(vm, bt);
910 	if (bt->bt_start != start) {
911 		btnew2->bt_type = BT_TYPE_FREE;
912 		btnew2->bt_start = bt->bt_start;
913 		btnew2->bt_size = start - bt->bt_start;
914 		bt->bt_start = start;
915 		bt->bt_size -= btnew2->bt_size;
916 		bt_insfree(vm, btnew2);
917 		bt_insseg(vm, btnew2, CIRCLEQ_PREV(bt, bt_seglist));
918 		btnew2 = NULL;
919 	}
920 	KASSERT(bt->bt_start == start);
921 	if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
922 		/* split */
923 		btnew->bt_type = BT_TYPE_BUSY;
924 		btnew->bt_start = bt->bt_start;
925 		btnew->bt_size = size;
926 		bt->bt_start = bt->bt_start + size;
927 		bt->bt_size -= size;
928 		bt_insfree(vm, bt);
929 		bt_insseg(vm, btnew, CIRCLEQ_PREV(bt, bt_seglist));
930 		bt_insbusy(vm, btnew);
931 		VMEM_UNLOCK(vm);
932 	} else {
933 		bt->bt_type = BT_TYPE_BUSY;
934 		bt_insbusy(vm, bt);
935 		VMEM_UNLOCK(vm);
936 		bt_free(vm, btnew);
937 		btnew = bt;
938 	}
939 	if (btnew2 != NULL) {
940 		bt_free(vm, btnew2);
941 	}
942 	KASSERT(btnew->bt_size >= size);
943 	btnew->bt_type = BT_TYPE_BUSY;
944 
945 	return btnew->bt_start;
946 }
947 
948 /*
949  * vmem_free:
950  *
951  * => caller must ensure appropriate spl,
952  *    if the arena can be accessed from interrupt context.
953  */
954 
955 void
956 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
957 {
958 
959 	VMEM_ASSERT_UNLOCKED(vm);
960 	KASSERT(addr != VMEM_ADDR_NULL);
961 	KASSERT(size > 0);
962 
963 #if defined(QCACHE)
964 	if (size <= vm->vm_qcache_max) {
965 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
966 		qcache_t *qc = &vm->vm_qcache[qidx - 1];
967 
968 		return pool_cache_put(&qc->qc_cache, (void *)addr);
969 	}
970 #endif /* defined(QCACHE) */
971 
972 	vmem_xfree(vm, addr, size);
973 }
974 
975 void
976 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
977 {
978 	bt_t *bt;
979 	bt_t *t;
980 
981 	VMEM_ASSERT_UNLOCKED(vm);
982 	KASSERT(addr != VMEM_ADDR_NULL);
983 	KASSERT(size > 0);
984 
985 	VMEM_LOCK(vm);
986 
987 	bt = bt_lookupbusy(vm, addr);
988 	KASSERT(bt != NULL);
989 	KASSERT(bt->bt_start == addr);
990 	KASSERT(bt->bt_size == vmem_roundup_size(vm, size) ||
991 	    bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
992 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
993 	bt_rembusy(vm, bt);
994 	bt->bt_type = BT_TYPE_FREE;
995 
996 	/* coalesce */
997 	t = CIRCLEQ_NEXT(bt, bt_seglist);
998 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
999 		KASSERT(BT_END(bt) == t->bt_start);
1000 		bt_remfree(vm, t);
1001 		bt_remseg(vm, t);
1002 		bt->bt_size += t->bt_size;
1003 		bt_free(vm, t);
1004 	}
1005 	t = CIRCLEQ_PREV(bt, bt_seglist);
1006 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1007 		KASSERT(BT_END(t) == bt->bt_start);
1008 		bt_remfree(vm, t);
1009 		bt_remseg(vm, t);
1010 		bt->bt_size += t->bt_size;
1011 		bt->bt_start = t->bt_start;
1012 		bt_free(vm, t);
1013 	}
1014 
1015 	t = CIRCLEQ_PREV(bt, bt_seglist);
1016 	KASSERT(t != NULL);
1017 	KASSERT(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY);
1018 	if (vm->vm_freefn != NULL && t->bt_type == BT_TYPE_SPAN &&
1019 	    t->bt_size == bt->bt_size) {
1020 		vmem_addr_t spanaddr;
1021 		vmem_size_t spansize;
1022 
1023 		KASSERT(t->bt_start == bt->bt_start);
1024 		spanaddr = bt->bt_start;
1025 		spansize = bt->bt_size;
1026 		bt_remseg(vm, bt);
1027 		bt_free(vm, bt);
1028 		bt_remseg(vm, t);
1029 		bt_free(vm, t);
1030 		VMEM_UNLOCK(vm);
1031 		(*vm->vm_freefn)(vm->vm_source, spanaddr, spansize);
1032 	} else {
1033 		bt_insfree(vm, bt);
1034 		VMEM_UNLOCK(vm);
1035 	}
1036 }
1037 
1038 /*
1039  * vmem_add:
1040  *
1041  * => caller must ensure appropriate spl,
1042  *    if the arena can be accessed from interrupt context.
1043  */
1044 
1045 vmem_addr_t
1046 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags)
1047 {
1048 
1049 	return vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN_STATIC);
1050 }
1051 
1052 /*
1053  * vmem_reap: reap unused resources.
1054  *
1055  * => return TRUE if we successfully reaped something.
1056  */
1057 
1058 boolean_t
1059 vmem_reap(vmem_t *vm)
1060 {
1061 	boolean_t didsomething = FALSE;
1062 
1063 	VMEM_ASSERT_UNLOCKED(vm);
1064 
1065 #if defined(QCACHE)
1066 	didsomething = qc_reap(vm);
1067 #endif /* defined(QCACHE) */
1068 	return didsomething;
1069 }
1070 
1071 /* ---- debug */
1072 
1073 #if defined(VMEM_DEBUG)
1074 
1075 #if !defined(_KERNEL)
1076 #include <stdio.h>
1077 #endif /* !defined(_KERNEL) */
1078 
1079 void bt_dump(const bt_t *);
1080 
1081 void
1082 bt_dump(const bt_t *bt)
1083 {
1084 
1085 	printf("\t%p: %" PRIu64 ", %" PRIu64 ", %d\n",
1086 	    bt, (uint64_t)bt->bt_start, (uint64_t)bt->bt_size,
1087 	    bt->bt_type);
1088 }
1089 
1090 void
1091 vmem_dump(const vmem_t *vm)
1092 {
1093 	const bt_t *bt;
1094 	int i;
1095 
1096 	printf("vmem %p '%s'\n", vm, vm->vm_name);
1097 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1098 		bt_dump(bt);
1099 	}
1100 
1101 	for (i = 0; i < VMEM_MAXORDER; i++) {
1102 		const struct vmem_freelist *fl = &vm->vm_freelist[i];
1103 
1104 		if (LIST_EMPTY(fl)) {
1105 			continue;
1106 		}
1107 
1108 		printf("freelist[%d]\n", i);
1109 		LIST_FOREACH(bt, fl, bt_freelist) {
1110 			bt_dump(bt);
1111 			if (bt->bt_size) {
1112 			}
1113 		}
1114 	}
1115 }
1116 
1117 #if !defined(_KERNEL)
1118 
1119 #include <stdlib.h>
1120 
1121 int
1122 main()
1123 {
1124 	vmem_t *vm;
1125 	vmem_addr_t p;
1126 	struct reg {
1127 		vmem_addr_t p;
1128 		vmem_size_t sz;
1129 		boolean_t x;
1130 	} *reg = NULL;
1131 	int nreg = 0;
1132 	int nalloc = 0;
1133 	int nfree = 0;
1134 	vmem_size_t total = 0;
1135 #if 1
1136 	vm_flag_t strat = VM_INSTANTFIT;
1137 #else
1138 	vm_flag_t strat = VM_BESTFIT;
1139 #endif
1140 
1141 	vm = vmem_create("test", VMEM_ADDR_NULL, 0, 1,
1142 	    NULL, NULL, NULL, 0, VM_NOSLEEP);
1143 	if (vm == NULL) {
1144 		printf("vmem_create\n");
1145 		exit(EXIT_FAILURE);
1146 	}
1147 	vmem_dump(vm);
1148 
1149 	p = vmem_add(vm, 100, 200, VM_SLEEP);
1150 	p = vmem_add(vm, 2000, 1, VM_SLEEP);
1151 	p = vmem_add(vm, 40000, 0x10000000>>12, VM_SLEEP);
1152 	p = vmem_add(vm, 10000, 10000, VM_SLEEP);
1153 	p = vmem_add(vm, 500, 1000, VM_SLEEP);
1154 	vmem_dump(vm);
1155 	for (;;) {
1156 		struct reg *r;
1157 		int t = rand() % 100;
1158 
1159 		if (t > 45) {
1160 			/* alloc */
1161 			vmem_size_t sz = rand() % 500 + 1;
1162 			boolean_t x;
1163 			vmem_size_t align, phase, nocross;
1164 			vmem_addr_t minaddr, maxaddr;
1165 
1166 			if (t > 70) {
1167 				x = TRUE;
1168 				/* XXX */
1169 				align = 1 << (rand() % 15);
1170 				phase = rand() % 65536;
1171 				nocross = 1 << (rand() % 15);
1172 				if (align <= phase) {
1173 					phase = 0;
1174 				}
1175 				if (VMEM_CROSS_P(phase, phase + sz - 1,
1176 				    nocross)) {
1177 					nocross = 0;
1178 				}
1179 				minaddr = rand() % 50000;
1180 				maxaddr = rand() % 70000;
1181 				if (minaddr > maxaddr) {
1182 					minaddr = 0;
1183 					maxaddr = 0;
1184 				}
1185 				printf("=== xalloc %" PRIu64
1186 				    " align=%" PRIu64 ", phase=%" PRIu64
1187 				    ", nocross=%" PRIu64 ", min=%" PRIu64
1188 				    ", max=%" PRIu64 "\n",
1189 				    (uint64_t)sz,
1190 				    (uint64_t)align,
1191 				    (uint64_t)phase,
1192 				    (uint64_t)nocross,
1193 				    (uint64_t)minaddr,
1194 				    (uint64_t)maxaddr);
1195 				p = vmem_xalloc(vm, sz, align, phase, nocross,
1196 				    minaddr, maxaddr, strat|VM_SLEEP);
1197 			} else {
1198 				x = FALSE;
1199 				printf("=== alloc %" PRIu64 "\n", (uint64_t)sz);
1200 				p = vmem_alloc(vm, sz, strat|VM_SLEEP);
1201 			}
1202 			printf("-> %" PRIu64 "\n", (uint64_t)p);
1203 			vmem_dump(vm);
1204 			if (p == VMEM_ADDR_NULL) {
1205 				if (x) {
1206 					continue;
1207 				}
1208 				break;
1209 			}
1210 			nreg++;
1211 			reg = realloc(reg, sizeof(*reg) * nreg);
1212 			r = &reg[nreg - 1];
1213 			r->p = p;
1214 			r->sz = sz;
1215 			r->x = x;
1216 			total += sz;
1217 			nalloc++;
1218 		} else if (nreg != 0) {
1219 			/* free */
1220 			r = &reg[rand() % nreg];
1221 			printf("=== free %" PRIu64 ", %" PRIu64 "\n",
1222 			    (uint64_t)r->p, (uint64_t)r->sz);
1223 			if (r->x) {
1224 				vmem_xfree(vm, r->p, r->sz);
1225 			} else {
1226 				vmem_free(vm, r->p, r->sz);
1227 			}
1228 			total -= r->sz;
1229 			vmem_dump(vm);
1230 			*r = reg[nreg - 1];
1231 			nreg--;
1232 			nfree++;
1233 		}
1234 		printf("total=%" PRIu64 "\n", (uint64_t)total);
1235 	}
1236 	fprintf(stderr, "total=%" PRIu64 ", nalloc=%d, nfree=%d\n",
1237 	    (uint64_t)total, nalloc, nfree);
1238 	exit(EXIT_SUCCESS);
1239 }
1240 #endif /* !defined(_KERNEL) */
1241 #endif /* defined(VMEM_DEBUG) */
1242