xref: /netbsd-src/sys/kern/subr_vmem.c (revision e39ef1d61eee3ccba837ee281f1e098c864487aa)
1 /*	$NetBSD: subr_vmem.c,v 1.65 2011/10/20 03:05:14 yamt Exp $	*/
2 
3 /*-
4  * Copyright (c)2006,2007,2008,2009 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 1.65 2011/10/20 03:05:14 yamt Exp $");
42 
43 #if defined(_KERNEL)
44 #include "opt_ddb.h"
45 #define	QCACHE
46 #endif /* defined(_KERNEL) */
47 
48 #include <sys/param.h>
49 #include <sys/hash.h>
50 #include <sys/queue.h>
51 #include <sys/bitops.h>
52 
53 #if defined(_KERNEL)
54 #include <sys/systm.h>
55 #include <sys/kernel.h>	/* hz */
56 #include <sys/callout.h>
57 #include <sys/malloc.h>
58 #include <sys/once.h>
59 #include <sys/pool.h>
60 #include <sys/vmem.h>
61 #include <sys/workqueue.h>
62 #else /* defined(_KERNEL) */
63 #include "../sys/vmem.h"
64 #endif /* defined(_KERNEL) */
65 
66 #if defined(_KERNEL)
67 #define	LOCK_DECL(name)		\
68     kmutex_t name; char lockpad[COHERENCY_UNIT - sizeof(kmutex_t)]
69 #else /* defined(_KERNEL) */
70 #include <errno.h>
71 #include <assert.h>
72 #include <stdlib.h>
73 #include <string.h>
74 
75 #define	UNITTEST
76 #define	KASSERT(a)		assert(a)
77 #define	LOCK_DECL(name)		/* nothing */
78 #define	mutex_init(a, b, c)	/* nothing */
79 #define	mutex_destroy(a)	/* nothing */
80 #define	mutex_enter(a)		/* nothing */
81 #define	mutex_tryenter(a)	true
82 #define	mutex_exit(a)		/* nothing */
83 #define	mutex_owned(a)		/* nothing */
84 #define	ASSERT_SLEEPABLE()	/* nothing */
85 #define	panic(...)		printf(__VA_ARGS__); abort()
86 #endif /* defined(_KERNEL) */
87 
88 struct vmem;
89 struct vmem_btag;
90 
91 #if defined(VMEM_SANITY)
92 static void vmem_check(vmem_t *);
93 #else /* defined(VMEM_SANITY) */
94 #define vmem_check(vm)	/* nothing */
95 #endif /* defined(VMEM_SANITY) */
96 
97 #define	VMEM_MAXORDER		(sizeof(vmem_size_t) * CHAR_BIT)
98 
99 #define	VMEM_HASHSIZE_MIN	1	/* XXX */
100 #define	VMEM_HASHSIZE_MAX	65536	/* XXX */
101 #define	VMEM_HASHSIZE_INIT	128
102 
103 #define	VM_FITMASK	(VM_BESTFIT | VM_INSTANTFIT)
104 
105 CIRCLEQ_HEAD(vmem_seglist, vmem_btag);
106 LIST_HEAD(vmem_freelist, vmem_btag);
107 LIST_HEAD(vmem_hashlist, vmem_btag);
108 
109 #if defined(QCACHE)
110 #define	VMEM_QCACHE_IDX_MAX	32
111 
112 #define	QC_NAME_MAX	16
113 
114 struct qcache {
115 	pool_cache_t qc_cache;
116 	vmem_t *qc_vmem;
117 	char qc_name[QC_NAME_MAX];
118 };
119 typedef struct qcache qcache_t;
120 #define	QC_POOL_TO_QCACHE(pool)	((qcache_t *)(pool->pr_qcache))
121 #endif /* defined(QCACHE) */
122 
123 #define	VMEM_NAME_MAX	16
124 
125 /* vmem arena */
126 struct vmem {
127 	LOCK_DECL(vm_lock);
128 	int (*vm_importfn)(void *, vmem_size_t, vmem_size_t *,
129 	    vm_flag_t, vmem_addr_t *);
130 	void (*vm_releasefn)(void *, vmem_addr_t, vmem_size_t);
131 	vmem_t *vm_source;
132 	void *vm_arg;
133 	struct vmem_seglist vm_seglist;
134 	struct vmem_freelist vm_freelist[VMEM_MAXORDER];
135 	size_t vm_hashsize;
136 	size_t vm_nbusytag;
137 	struct vmem_hashlist *vm_hashlist;
138 	size_t vm_quantum_mask;
139 	int vm_quantum_shift;
140 	char vm_name[VMEM_NAME_MAX+1];
141 	LIST_ENTRY(vmem) vm_alllist;
142 
143 #if defined(QCACHE)
144 	/* quantum cache */
145 	size_t vm_qcache_max;
146 	struct pool_allocator vm_qcache_allocator;
147 	qcache_t vm_qcache_store[VMEM_QCACHE_IDX_MAX];
148 	qcache_t *vm_qcache[VMEM_QCACHE_IDX_MAX];
149 #endif /* defined(QCACHE) */
150 };
151 
152 #define	VMEM_LOCK(vm)		mutex_enter(&vm->vm_lock)
153 #define	VMEM_TRYLOCK(vm)	mutex_tryenter(&vm->vm_lock)
154 #define	VMEM_UNLOCK(vm)		mutex_exit(&vm->vm_lock)
155 #define	VMEM_LOCK_INIT(vm, ipl)	mutex_init(&vm->vm_lock, MUTEX_DEFAULT, ipl)
156 #define	VMEM_LOCK_DESTROY(vm)	mutex_destroy(&vm->vm_lock)
157 #define	VMEM_ASSERT_LOCKED(vm)	KASSERT(mutex_owned(&vm->vm_lock))
158 
159 /* boundary tag */
160 struct vmem_btag {
161 	CIRCLEQ_ENTRY(vmem_btag) bt_seglist;
162 	union {
163 		LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */
164 		LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */
165 	} bt_u;
166 #define	bt_hashlist	bt_u.u_hashlist
167 #define	bt_freelist	bt_u.u_freelist
168 	vmem_addr_t bt_start;
169 	vmem_size_t bt_size;
170 	int bt_type;
171 };
172 
173 #define	BT_TYPE_SPAN		1
174 #define	BT_TYPE_SPAN_STATIC	2
175 #define	BT_TYPE_FREE		3
176 #define	BT_TYPE_BUSY		4
177 #define	BT_ISSPAN_P(bt)	((bt)->bt_type <= BT_TYPE_SPAN_STATIC)
178 
179 #define	BT_END(bt)	((bt)->bt_start + (bt)->bt_size - 1)
180 
181 typedef struct vmem_btag bt_t;
182 
183 /* ---- misc */
184 
185 #define	VMEM_ALIGNUP(addr, align) \
186 	(-(-(addr) & -(align)))
187 
188 #define	VMEM_CROSS_P(addr1, addr2, boundary) \
189 	((((addr1) ^ (addr2)) & -(boundary)) != 0)
190 
191 #define	ORDER2SIZE(order)	((vmem_size_t)1 << (order))
192 #define	SIZE2ORDER(size)	((int)ilog2(size))
193 
194 #if !defined(_KERNEL)
195 #define	xmalloc(sz, flags)	malloc(sz)
196 #define	xfree(p)		free(p)
197 #define	bt_alloc(vm, flags)	malloc(sizeof(bt_t))
198 #define	bt_free(vm, bt)		free(bt)
199 #else	/* !defined(_KERNEL) */
200 
201 static MALLOC_DEFINE(M_VMEM, "vmem", "vmem");
202 
203 static inline void *
204 xmalloc(size_t sz, vm_flag_t flags)
205 {
206 	return malloc(sz, M_VMEM,
207 	    M_CANFAIL | ((flags & VM_SLEEP) ? M_WAITOK : M_NOWAIT));
208 }
209 
210 static inline void
211 xfree(void *p)
212 {
213 	free(p, M_VMEM);
214 }
215 
216 /* ---- boundary tag */
217 
218 static struct pool_cache bt_cache;
219 
220 static inline bt_t *
221 bt_alloc(vmem_t *vm, vm_flag_t flags)
222 {
223 	return pool_cache_get(&bt_cache,
224 	    (flags & VM_SLEEP) ? PR_WAITOK : PR_NOWAIT);
225 }
226 
227 static inline void
228 bt_free(vmem_t *vm, bt_t *bt)
229 {
230 	pool_cache_put(&bt_cache, bt);
231 }
232 
233 #endif	/* !defined(_KERNEL) */
234 
235 /*
236  * freelist[0] ... [1, 1]
237  * freelist[1] ... [2, 3]
238  * freelist[2] ... [4, 7]
239  * freelist[3] ... [8, 15]
240  *  :
241  * freelist[n] ... [(1 << n), (1 << (n + 1)) - 1]
242  *  :
243  */
244 
245 static struct vmem_freelist *
246 bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
247 {
248 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
249 	const int idx = SIZE2ORDER(qsize);
250 
251 	KASSERT(size != 0 && qsize != 0);
252 	KASSERT((size & vm->vm_quantum_mask) == 0);
253 	KASSERT(idx >= 0);
254 	KASSERT(idx < VMEM_MAXORDER);
255 
256 	return &vm->vm_freelist[idx];
257 }
258 
259 /*
260  * bt_freehead_toalloc: return the freelist for the given size and allocation
261  * strategy.
262  *
263  * for VM_INSTANTFIT, return the list in which any blocks are large enough
264  * for the requested size.  otherwise, return the list which can have blocks
265  * large enough for the requested size.
266  */
267 
268 static struct vmem_freelist *
269 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, vm_flag_t strat)
270 {
271 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
272 	int idx = SIZE2ORDER(qsize);
273 
274 	KASSERT(size != 0 && qsize != 0);
275 	KASSERT((size & vm->vm_quantum_mask) == 0);
276 
277 	if (strat == VM_INSTANTFIT && ORDER2SIZE(idx) != qsize) {
278 		idx++;
279 		/* check too large request? */
280 	}
281 	KASSERT(idx >= 0);
282 	KASSERT(idx < VMEM_MAXORDER);
283 
284 	return &vm->vm_freelist[idx];
285 }
286 
287 /* ---- boundary tag hash */
288 
289 static struct vmem_hashlist *
290 bt_hashhead(vmem_t *vm, vmem_addr_t addr)
291 {
292 	struct vmem_hashlist *list;
293 	unsigned int hash;
294 
295 	hash = hash32_buf(&addr, sizeof(addr), HASH32_BUF_INIT);
296 	list = &vm->vm_hashlist[hash % vm->vm_hashsize];
297 
298 	return list;
299 }
300 
301 static bt_t *
302 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
303 {
304 	struct vmem_hashlist *list;
305 	bt_t *bt;
306 
307 	list = bt_hashhead(vm, addr);
308 	LIST_FOREACH(bt, list, bt_hashlist) {
309 		if (bt->bt_start == addr) {
310 			break;
311 		}
312 	}
313 
314 	return bt;
315 }
316 
317 static void
318 bt_rembusy(vmem_t *vm, bt_t *bt)
319 {
320 
321 	KASSERT(vm->vm_nbusytag > 0);
322 	vm->vm_nbusytag--;
323 	LIST_REMOVE(bt, bt_hashlist);
324 }
325 
326 static void
327 bt_insbusy(vmem_t *vm, bt_t *bt)
328 {
329 	struct vmem_hashlist *list;
330 
331 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
332 
333 	list = bt_hashhead(vm, bt->bt_start);
334 	LIST_INSERT_HEAD(list, bt, bt_hashlist);
335 	vm->vm_nbusytag++;
336 }
337 
338 /* ---- boundary tag list */
339 
340 static void
341 bt_remseg(vmem_t *vm, bt_t *bt)
342 {
343 
344 	CIRCLEQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
345 }
346 
347 static void
348 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
349 {
350 
351 	CIRCLEQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
352 }
353 
354 static void
355 bt_insseg_tail(vmem_t *vm, bt_t *bt)
356 {
357 
358 	CIRCLEQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
359 }
360 
361 static void
362 bt_remfree(vmem_t *vm, bt_t *bt)
363 {
364 
365 	KASSERT(bt->bt_type == BT_TYPE_FREE);
366 
367 	LIST_REMOVE(bt, bt_freelist);
368 }
369 
370 static void
371 bt_insfree(vmem_t *vm, bt_t *bt)
372 {
373 	struct vmem_freelist *list;
374 
375 	list = bt_freehead_tofree(vm, bt->bt_size);
376 	LIST_INSERT_HEAD(list, bt, bt_freelist);
377 }
378 
379 /* ---- vmem internal functions */
380 
381 #if defined(_KERNEL)
382 static kmutex_t vmem_list_lock;
383 static LIST_HEAD(, vmem) vmem_list = LIST_HEAD_INITIALIZER(vmem_list);
384 #endif /* defined(_KERNEL) */
385 
386 #if defined(QCACHE)
387 static inline vm_flag_t
388 prf_to_vmf(int prflags)
389 {
390 	vm_flag_t vmflags;
391 
392 	KASSERT((prflags & ~(PR_LIMITFAIL | PR_WAITOK | PR_NOWAIT)) == 0);
393 	if ((prflags & PR_WAITOK) != 0) {
394 		vmflags = VM_SLEEP;
395 	} else {
396 		vmflags = VM_NOSLEEP;
397 	}
398 	return vmflags;
399 }
400 
401 static inline int
402 vmf_to_prf(vm_flag_t vmflags)
403 {
404 	int prflags;
405 
406 	if ((vmflags & VM_SLEEP) != 0) {
407 		prflags = PR_WAITOK;
408 	} else {
409 		prflags = PR_NOWAIT;
410 	}
411 	return prflags;
412 }
413 
414 static size_t
415 qc_poolpage_size(size_t qcache_max)
416 {
417 	int i;
418 
419 	for (i = 0; ORDER2SIZE(i) <= qcache_max * 3; i++) {
420 		/* nothing */
421 	}
422 	return ORDER2SIZE(i);
423 }
424 
425 static void *
426 qc_poolpage_alloc(struct pool *pool, int prflags)
427 {
428 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
429 	vmem_t *vm = qc->qc_vmem;
430 	vmem_addr_t addr;
431 
432 	if (vmem_alloc(vm, pool->pr_alloc->pa_pagesz,
433 	    prf_to_vmf(prflags) | VM_INSTANTFIT, &addr) != 0)
434 		return NULL;
435 	return (void *)addr;
436 }
437 
438 static void
439 qc_poolpage_free(struct pool *pool, void *addr)
440 {
441 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
442 	vmem_t *vm = qc->qc_vmem;
443 
444 	vmem_free(vm, (vmem_addr_t)addr, pool->pr_alloc->pa_pagesz);
445 }
446 
447 static void
448 qc_init(vmem_t *vm, size_t qcache_max, int ipl)
449 {
450 	qcache_t *prevqc;
451 	struct pool_allocator *pa;
452 	int qcache_idx_max;
453 	int i;
454 
455 	KASSERT((qcache_max & vm->vm_quantum_mask) == 0);
456 	if (qcache_max > (VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift)) {
457 		qcache_max = VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift;
458 	}
459 	vm->vm_qcache_max = qcache_max;
460 	pa = &vm->vm_qcache_allocator;
461 	memset(pa, 0, sizeof(*pa));
462 	pa->pa_alloc = qc_poolpage_alloc;
463 	pa->pa_free = qc_poolpage_free;
464 	pa->pa_pagesz = qc_poolpage_size(qcache_max);
465 
466 	qcache_idx_max = qcache_max >> vm->vm_quantum_shift;
467 	prevqc = NULL;
468 	for (i = qcache_idx_max; i > 0; i--) {
469 		qcache_t *qc = &vm->vm_qcache_store[i - 1];
470 		size_t size = i << vm->vm_quantum_shift;
471 
472 		qc->qc_vmem = vm;
473 		snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu",
474 		    vm->vm_name, size);
475 		qc->qc_cache = pool_cache_init(size,
476 		    ORDER2SIZE(vm->vm_quantum_shift), 0,
477 		    PR_NOALIGN | PR_NOTOUCH /* XXX */,
478 		    qc->qc_name, pa, ipl, NULL, NULL, NULL);
479 		KASSERT(qc->qc_cache != NULL);	/* XXX */
480 		if (prevqc != NULL &&
481 		    qc->qc_cache->pc_pool.pr_itemsperpage ==
482 		    prevqc->qc_cache->pc_pool.pr_itemsperpage) {
483 			pool_cache_destroy(qc->qc_cache);
484 			vm->vm_qcache[i - 1] = prevqc;
485 			continue;
486 		}
487 		qc->qc_cache->pc_pool.pr_qcache = qc;
488 		vm->vm_qcache[i - 1] = qc;
489 		prevqc = qc;
490 	}
491 }
492 
493 static void
494 qc_destroy(vmem_t *vm)
495 {
496 	const qcache_t *prevqc;
497 	int i;
498 	int qcache_idx_max;
499 
500 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
501 	prevqc = NULL;
502 	for (i = 0; i < qcache_idx_max; i++) {
503 		qcache_t *qc = vm->vm_qcache[i];
504 
505 		if (prevqc == qc) {
506 			continue;
507 		}
508 		pool_cache_destroy(qc->qc_cache);
509 		prevqc = qc;
510 	}
511 }
512 
513 static bool
514 qc_reap(vmem_t *vm)
515 {
516 	const qcache_t *prevqc;
517 	int i;
518 	int qcache_idx_max;
519 	bool didsomething = false;
520 
521 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
522 	prevqc = NULL;
523 	for (i = 0; i < qcache_idx_max; i++) {
524 		qcache_t *qc = vm->vm_qcache[i];
525 
526 		if (prevqc == qc) {
527 			continue;
528 		}
529 		if (pool_cache_reclaim(qc->qc_cache) != 0) {
530 			didsomething = true;
531 		}
532 		prevqc = qc;
533 	}
534 
535 	return didsomething;
536 }
537 #endif /* defined(QCACHE) */
538 
539 #if defined(_KERNEL)
540 static int
541 vmem_init(void)
542 {
543 
544 	mutex_init(&vmem_list_lock, MUTEX_DEFAULT, IPL_NONE);
545 	pool_cache_bootstrap(&bt_cache, sizeof(bt_t), 0, 0, 0, "vmembt",
546 	    NULL, IPL_VM, NULL, NULL, NULL);
547 	return 0;
548 }
549 #endif /* defined(_KERNEL) */
550 
551 static int
552 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags,
553     int spanbttype)
554 {
555 	bt_t *btspan;
556 	bt_t *btfree;
557 
558 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
559 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
560 	KASSERT(spanbttype == BT_TYPE_SPAN ||
561 	    spanbttype == BT_TYPE_SPAN_STATIC);
562 
563 	btspan = bt_alloc(vm, flags);
564 	if (btspan == NULL) {
565 		return ENOMEM;
566 	}
567 	btfree = bt_alloc(vm, flags);
568 	if (btfree == NULL) {
569 		bt_free(vm, btspan);
570 		return ENOMEM;
571 	}
572 
573 	btspan->bt_type = spanbttype;
574 	btspan->bt_start = addr;
575 	btspan->bt_size = size;
576 
577 	btfree->bt_type = BT_TYPE_FREE;
578 	btfree->bt_start = addr;
579 	btfree->bt_size = size;
580 
581 	VMEM_LOCK(vm);
582 	bt_insseg_tail(vm, btspan);
583 	bt_insseg(vm, btfree, btspan);
584 	bt_insfree(vm, btfree);
585 	VMEM_UNLOCK(vm);
586 
587 	return 0;
588 }
589 
590 static void
591 vmem_destroy1(vmem_t *vm)
592 {
593 
594 #if defined(QCACHE)
595 	qc_destroy(vm);
596 #endif /* defined(QCACHE) */
597 	if (vm->vm_hashlist != NULL) {
598 		int i;
599 
600 		for (i = 0; i < vm->vm_hashsize; i++) {
601 			bt_t *bt;
602 
603 			while ((bt = LIST_FIRST(&vm->vm_hashlist[i])) != NULL) {
604 				KASSERT(bt->bt_type == BT_TYPE_SPAN_STATIC);
605 				bt_free(vm, bt);
606 			}
607 		}
608 		xfree(vm->vm_hashlist);
609 	}
610 	VMEM_LOCK_DESTROY(vm);
611 	xfree(vm);
612 }
613 
614 static int
615 vmem_import(vmem_t *vm, vmem_size_t size, vm_flag_t flags)
616 {
617 	vmem_addr_t addr;
618 	int rc;
619 
620 	if (vm->vm_importfn == NULL) {
621 		return EINVAL;
622 	}
623 
624 	rc = (*vm->vm_importfn)(vm->vm_arg, size, &size, flags, &addr);
625 	if (rc != 0) {
626 		return ENOMEM;
627 	}
628 
629 	if (vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN) != 0) {
630 		(*vm->vm_releasefn)(vm->vm_arg, addr, size);
631 		return ENOMEM;
632 	}
633 
634 	return 0;
635 }
636 
637 static int
638 vmem_rehash(vmem_t *vm, size_t newhashsize, vm_flag_t flags)
639 {
640 	bt_t *bt;
641 	int i;
642 	struct vmem_hashlist *newhashlist;
643 	struct vmem_hashlist *oldhashlist;
644 	size_t oldhashsize;
645 
646 	KASSERT(newhashsize > 0);
647 
648 	newhashlist =
649 	    xmalloc(sizeof(struct vmem_hashlist *) * newhashsize, flags);
650 	if (newhashlist == NULL) {
651 		return ENOMEM;
652 	}
653 	for (i = 0; i < newhashsize; i++) {
654 		LIST_INIT(&newhashlist[i]);
655 	}
656 
657 	if (!VMEM_TRYLOCK(vm)) {
658 		xfree(newhashlist);
659 		return EBUSY;
660 	}
661 	oldhashlist = vm->vm_hashlist;
662 	oldhashsize = vm->vm_hashsize;
663 	vm->vm_hashlist = newhashlist;
664 	vm->vm_hashsize = newhashsize;
665 	if (oldhashlist == NULL) {
666 		VMEM_UNLOCK(vm);
667 		return 0;
668 	}
669 	for (i = 0; i < oldhashsize; i++) {
670 		while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
671 			bt_rembusy(vm, bt); /* XXX */
672 			bt_insbusy(vm, bt);
673 		}
674 	}
675 	VMEM_UNLOCK(vm);
676 
677 	xfree(oldhashlist);
678 
679 	return 0;
680 }
681 
682 /*
683  * vmem_fit: check if a bt can satisfy the given restrictions.
684  *
685  * it's a caller's responsibility to ensure the region is big enough
686  * before calling us.
687  */
688 
689 static int
690 vmem_fit(const bt_t const *bt, vmem_size_t size, vmem_size_t align,
691     vmem_size_t phase, vmem_size_t nocross,
692     vmem_addr_t minaddr, vmem_addr_t maxaddr, vmem_addr_t *addrp)
693 {
694 	vmem_addr_t start;
695 	vmem_addr_t end;
696 
697 	KASSERT(size > 0);
698 	KASSERT(bt->bt_size >= size); /* caller's responsibility */
699 
700 	/*
701 	 * XXX assumption: vmem_addr_t and vmem_size_t are
702 	 * unsigned integer of the same size.
703 	 */
704 
705 	start = bt->bt_start;
706 	if (start < minaddr) {
707 		start = minaddr;
708 	}
709 	end = BT_END(bt);
710 	if (end > maxaddr) {
711 		end = maxaddr;
712 	}
713 	if (start > end) {
714 		return ENOMEM;
715 	}
716 
717 	start = VMEM_ALIGNUP(start - phase, align) + phase;
718 	if (start < bt->bt_start) {
719 		start += align;
720 	}
721 	if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
722 		KASSERT(align < nocross);
723 		start = VMEM_ALIGNUP(start - phase, nocross) + phase;
724 	}
725 	if (start <= end && end - start >= size - 1) {
726 		KASSERT((start & (align - 1)) == phase);
727 		KASSERT(!VMEM_CROSS_P(start, start + size - 1, nocross));
728 		KASSERT(minaddr <= start);
729 		KASSERT(maxaddr == 0 || start + size - 1 <= maxaddr);
730 		KASSERT(bt->bt_start <= start);
731 		KASSERT(BT_END(bt) - start >= size - 1);
732 		*addrp = start;
733 		return 0;
734 	}
735 	return ENOMEM;
736 }
737 
738 /* ---- vmem API */
739 
740 /*
741  * vmem_create: create an arena.
742  *
743  * => must not be called from interrupt context.
744  */
745 
746 vmem_t *
747 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
748     vmem_size_t quantum,
749     int (*importfn)(void *, vmem_size_t, vmem_size_t *, vm_flag_t,
750         vmem_addr_t *),
751     void (*releasefn)(void *, vmem_addr_t, vmem_size_t),
752     void *arg, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
753 {
754 	vmem_t *vm;
755 	int i;
756 #if defined(_KERNEL)
757 	static ONCE_DECL(control);
758 #endif /* defined(_KERNEL) */
759 
760 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
761 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
762 	KASSERT(quantum > 0);
763 
764 #if defined(_KERNEL)
765 	if (RUN_ONCE(&control, vmem_init)) {
766 		return NULL;
767 	}
768 #endif /* defined(_KERNEL) */
769 	vm = xmalloc(sizeof(*vm), flags);
770 	if (vm == NULL) {
771 		return NULL;
772 	}
773 
774 	VMEM_LOCK_INIT(vm, ipl);
775 	strlcpy(vm->vm_name, name, sizeof(vm->vm_name));
776 	vm->vm_quantum_mask = quantum - 1;
777 	vm->vm_quantum_shift = SIZE2ORDER(quantum);
778 	KASSERT(ORDER2SIZE(vm->vm_quantum_shift) == quantum);
779 	vm->vm_importfn = importfn;
780 	vm->vm_releasefn = releasefn;
781 	vm->vm_arg = arg;
782 	vm->vm_nbusytag = 0;
783 #if defined(QCACHE)
784 	qc_init(vm, qcache_max, ipl);
785 #endif /* defined(QCACHE) */
786 
787 	CIRCLEQ_INIT(&vm->vm_seglist);
788 	for (i = 0; i < VMEM_MAXORDER; i++) {
789 		LIST_INIT(&vm->vm_freelist[i]);
790 	}
791 	vm->vm_hashlist = NULL;
792 	if (vmem_rehash(vm, VMEM_HASHSIZE_INIT, flags)) {
793 		vmem_destroy1(vm);
794 		return NULL;
795 	}
796 
797 	if (size != 0) {
798 		if (vmem_add(vm, base, size, flags) != 0) {
799 			vmem_destroy1(vm);
800 			return NULL;
801 		}
802 	}
803 
804 #if defined(_KERNEL)
805 	mutex_enter(&vmem_list_lock);
806 	LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist);
807 	mutex_exit(&vmem_list_lock);
808 #endif /* defined(_KERNEL) */
809 
810 	return vm;
811 }
812 
813 void
814 vmem_destroy(vmem_t *vm)
815 {
816 
817 #if defined(_KERNEL)
818 	mutex_enter(&vmem_list_lock);
819 	LIST_REMOVE(vm, vm_alllist);
820 	mutex_exit(&vmem_list_lock);
821 #endif /* defined(_KERNEL) */
822 
823 	vmem_destroy1(vm);
824 }
825 
826 vmem_size_t
827 vmem_roundup_size(vmem_t *vm, vmem_size_t size)
828 {
829 
830 	return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
831 }
832 
833 /*
834  * vmem_alloc:
835  *
836  * => caller must ensure appropriate spl,
837  *    if the arena can be accessed from interrupt context.
838  */
839 
840 int
841 vmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, vmem_addr_t *addrp)
842 {
843 	const vm_flag_t strat __unused = flags & VM_FITMASK;
844 
845 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
846 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
847 
848 	KASSERT(size > 0);
849 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
850 	if ((flags & VM_SLEEP) != 0) {
851 		ASSERT_SLEEPABLE();
852 	}
853 
854 #if defined(QCACHE)
855 	if (size <= vm->vm_qcache_max) {
856 		void *p;
857 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
858 		qcache_t *qc = vm->vm_qcache[qidx - 1];
859 
860 		p = pool_cache_get(qc->qc_cache, vmf_to_prf(flags));
861 		if (addrp != NULL)
862 			*addrp = (vmem_addr_t)p;
863 		return (p == NULL) ? ENOMEM : 0;
864 	}
865 #endif /* defined(QCACHE) */
866 
867 	return vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
868 	    flags, addrp);
869 }
870 
871 int
872 vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align,
873     const vmem_size_t phase, const vmem_size_t nocross,
874     const vmem_addr_t minaddr, const vmem_addr_t maxaddr, const vm_flag_t flags,
875     vmem_addr_t *addrp)
876 {
877 	struct vmem_freelist *list;
878 	struct vmem_freelist *first;
879 	struct vmem_freelist *end;
880 	bt_t *bt;
881 	bt_t *btnew;
882 	bt_t *btnew2;
883 	const vmem_size_t size = vmem_roundup_size(vm, size0);
884 	vm_flag_t strat = flags & VM_FITMASK;
885 	vmem_addr_t start;
886 	int rc;
887 
888 	KASSERT(size0 > 0);
889 	KASSERT(size > 0);
890 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
891 	if ((flags & VM_SLEEP) != 0) {
892 		ASSERT_SLEEPABLE();
893 	}
894 	KASSERT((align & vm->vm_quantum_mask) == 0);
895 	KASSERT((align & (align - 1)) == 0);
896 	KASSERT((phase & vm->vm_quantum_mask) == 0);
897 	KASSERT((nocross & vm->vm_quantum_mask) == 0);
898 	KASSERT((nocross & (nocross - 1)) == 0);
899 	KASSERT((align == 0 && phase == 0) || phase < align);
900 	KASSERT(nocross == 0 || nocross >= size);
901 	KASSERT(minaddr <= maxaddr);
902 	KASSERT(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
903 
904 	if (align == 0) {
905 		align = vm->vm_quantum_mask + 1;
906 	}
907 
908 	/*
909 	 * allocate boundary tags before acquiring the vmem lock.
910 	 */
911 	btnew = bt_alloc(vm, flags);
912 	if (btnew == NULL) {
913 		return ENOMEM;
914 	}
915 	btnew2 = bt_alloc(vm, flags); /* XXX not necessary if no restrictions */
916 	if (btnew2 == NULL) {
917 		bt_free(vm, btnew);
918 		return ENOMEM;
919 	}
920 
921 	/*
922 	 * choose a free block from which we allocate.
923 	 */
924 retry_strat:
925 	first = bt_freehead_toalloc(vm, size, strat);
926 	end = &vm->vm_freelist[VMEM_MAXORDER];
927 retry:
928 	bt = NULL;
929 	VMEM_LOCK(vm);
930 	vmem_check(vm);
931 	if (strat == VM_INSTANTFIT) {
932 		/*
933 		 * just choose the first block which satisfies our restrictions.
934 		 *
935 		 * note that we don't need to check the size of the blocks
936 		 * because any blocks found on these list should be larger than
937 		 * the given size.
938 		 */
939 		for (list = first; list < end; list++) {
940 			bt = LIST_FIRST(list);
941 			if (bt != NULL) {
942 				rc = vmem_fit(bt, size, align, phase,
943 				    nocross, minaddr, maxaddr, &start);
944 				if (rc == 0) {
945 					goto gotit;
946 				}
947 				/*
948 				 * don't bother to follow the bt_freelist link
949 				 * here.  the list can be very long and we are
950 				 * told to run fast.  blocks from the later free
951 				 * lists are larger and have better chances to
952 				 * satisfy our restrictions.
953 				 */
954 			}
955 		}
956 	} else { /* VM_BESTFIT */
957 		/*
958 		 * we assume that, for space efficiency, it's better to
959 		 * allocate from a smaller block.  thus we will start searching
960 		 * from the lower-order list than VM_INSTANTFIT.
961 		 * however, don't bother to find the smallest block in a free
962 		 * list because the list can be very long.  we can revisit it
963 		 * if/when it turns out to be a problem.
964 		 *
965 		 * note that the 'first' list can contain blocks smaller than
966 		 * the requested size.  thus we need to check bt_size.
967 		 */
968 		for (list = first; list < end; list++) {
969 			LIST_FOREACH(bt, list, bt_freelist) {
970 				if (bt->bt_size >= size) {
971 					rc = vmem_fit(bt, size, align, phase,
972 					    nocross, minaddr, maxaddr, &start);
973 					if (rc == 0) {
974 						goto gotit;
975 					}
976 				}
977 			}
978 		}
979 	}
980 	VMEM_UNLOCK(vm);
981 #if 1
982 	if (strat == VM_INSTANTFIT) {
983 		strat = VM_BESTFIT;
984 		goto retry_strat;
985 	}
986 #endif
987 	if (align != vm->vm_quantum_mask + 1 || phase != 0 ||
988 	    nocross != 0) {
989 
990 		/*
991 		 * XXX should try to import a region large enough to
992 		 * satisfy restrictions?
993 		 */
994 
995 		goto fail;
996 	}
997 	/* XXX eeek, minaddr & maxaddr not respected */
998 	if (vmem_import(vm, size, flags) == 0) {
999 		goto retry;
1000 	}
1001 	/* XXX */
1002 fail:
1003 	bt_free(vm, btnew);
1004 	bt_free(vm, btnew2);
1005 	return ENOMEM;
1006 
1007 gotit:
1008 	KASSERT(bt->bt_type == BT_TYPE_FREE);
1009 	KASSERT(bt->bt_size >= size);
1010 	bt_remfree(vm, bt);
1011 	vmem_check(vm);
1012 	if (bt->bt_start != start) {
1013 		btnew2->bt_type = BT_TYPE_FREE;
1014 		btnew2->bt_start = bt->bt_start;
1015 		btnew2->bt_size = start - bt->bt_start;
1016 		bt->bt_start = start;
1017 		bt->bt_size -= btnew2->bt_size;
1018 		bt_insfree(vm, btnew2);
1019 		bt_insseg(vm, btnew2, CIRCLEQ_PREV(bt, bt_seglist));
1020 		btnew2 = NULL;
1021 		vmem_check(vm);
1022 	}
1023 	KASSERT(bt->bt_start == start);
1024 	if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
1025 		/* split */
1026 		btnew->bt_type = BT_TYPE_BUSY;
1027 		btnew->bt_start = bt->bt_start;
1028 		btnew->bt_size = size;
1029 		bt->bt_start = bt->bt_start + size;
1030 		bt->bt_size -= size;
1031 		bt_insfree(vm, bt);
1032 		bt_insseg(vm, btnew, CIRCLEQ_PREV(bt, bt_seglist));
1033 		bt_insbusy(vm, btnew);
1034 		vmem_check(vm);
1035 		VMEM_UNLOCK(vm);
1036 	} else {
1037 		bt->bt_type = BT_TYPE_BUSY;
1038 		bt_insbusy(vm, bt);
1039 		vmem_check(vm);
1040 		VMEM_UNLOCK(vm);
1041 		bt_free(vm, btnew);
1042 		btnew = bt;
1043 	}
1044 	if (btnew2 != NULL) {
1045 		bt_free(vm, btnew2);
1046 	}
1047 	KASSERT(btnew->bt_size >= size);
1048 	btnew->bt_type = BT_TYPE_BUSY;
1049 
1050 	if (addrp != NULL)
1051 		*addrp = btnew->bt_start;
1052 	return 0;
1053 }
1054 
1055 /*
1056  * vmem_free:
1057  *
1058  * => caller must ensure appropriate spl,
1059  *    if the arena can be accessed from interrupt context.
1060  */
1061 
1062 void
1063 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1064 {
1065 
1066 	KASSERT(size > 0);
1067 
1068 #if defined(QCACHE)
1069 	if (size <= vm->vm_qcache_max) {
1070 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1071 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1072 
1073 		pool_cache_put(qc->qc_cache, (void *)addr);
1074 		return;
1075 	}
1076 #endif /* defined(QCACHE) */
1077 
1078 	vmem_xfree(vm, addr, size);
1079 }
1080 
1081 void
1082 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1083 {
1084 	bt_t *bt;
1085 	bt_t *t;
1086 
1087 	KASSERT(size > 0);
1088 
1089 	VMEM_LOCK(vm);
1090 
1091 	bt = bt_lookupbusy(vm, addr);
1092 	KASSERT(bt != NULL);
1093 	KASSERT(bt->bt_start == addr);
1094 	KASSERT(bt->bt_size == vmem_roundup_size(vm, size) ||
1095 	    bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
1096 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
1097 	bt_rembusy(vm, bt);
1098 	bt->bt_type = BT_TYPE_FREE;
1099 
1100 	/* coalesce */
1101 	t = CIRCLEQ_NEXT(bt, bt_seglist);
1102 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1103 		KASSERT(BT_END(bt) < t->bt_start);	/* YYY */
1104 		bt_remfree(vm, t);
1105 		bt_remseg(vm, t);
1106 		bt->bt_size += t->bt_size;
1107 		bt_free(vm, t);
1108 	}
1109 	t = CIRCLEQ_PREV(bt, bt_seglist);
1110 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1111 		KASSERT(BT_END(t) < bt->bt_start);	/* YYY */
1112 		bt_remfree(vm, t);
1113 		bt_remseg(vm, t);
1114 		bt->bt_size += t->bt_size;
1115 		bt->bt_start = t->bt_start;
1116 		bt_free(vm, t);
1117 	}
1118 
1119 	t = CIRCLEQ_PREV(bt, bt_seglist);
1120 	KASSERT(t != NULL);
1121 	KASSERT(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY);
1122 	if (vm->vm_releasefn != NULL && t->bt_type == BT_TYPE_SPAN &&
1123 	    t->bt_size == bt->bt_size) {
1124 		vmem_addr_t spanaddr;
1125 		vmem_size_t spansize;
1126 
1127 		KASSERT(t->bt_start == bt->bt_start);
1128 		spanaddr = bt->bt_start;
1129 		spansize = bt->bt_size;
1130 		bt_remseg(vm, bt);
1131 		bt_free(vm, bt);
1132 		bt_remseg(vm, t);
1133 		bt_free(vm, t);
1134 		VMEM_UNLOCK(vm);
1135 		(*vm->vm_releasefn)(vm->vm_arg, spanaddr, spansize);
1136 	} else {
1137 		bt_insfree(vm, bt);
1138 		VMEM_UNLOCK(vm);
1139 	}
1140 }
1141 
1142 /*
1143  * vmem_add:
1144  *
1145  * => caller must ensure appropriate spl,
1146  *    if the arena can be accessed from interrupt context.
1147  */
1148 
1149 int
1150 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags)
1151 {
1152 
1153 	return vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN_STATIC);
1154 }
1155 
1156 /*
1157  * vmem_reap: reap unused resources.
1158  *
1159  * => return true if we successfully reaped something.
1160  */
1161 
1162 bool
1163 vmem_reap(vmem_t *vm)
1164 {
1165 	bool didsomething = false;
1166 
1167 #if defined(QCACHE)
1168 	didsomething = qc_reap(vm);
1169 #endif /* defined(QCACHE) */
1170 	return didsomething;
1171 }
1172 
1173 /* ---- rehash */
1174 
1175 #if defined(_KERNEL)
1176 static struct callout vmem_rehash_ch;
1177 static int vmem_rehash_interval;
1178 static struct workqueue *vmem_rehash_wq;
1179 static struct work vmem_rehash_wk;
1180 
1181 static void
1182 vmem_rehash_all(struct work *wk, void *dummy)
1183 {
1184 	vmem_t *vm;
1185 
1186 	KASSERT(wk == &vmem_rehash_wk);
1187 	mutex_enter(&vmem_list_lock);
1188 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1189 		size_t desired;
1190 		size_t current;
1191 
1192 		if (!VMEM_TRYLOCK(vm)) {
1193 			continue;
1194 		}
1195 		desired = vm->vm_nbusytag;
1196 		current = vm->vm_hashsize;
1197 		VMEM_UNLOCK(vm);
1198 
1199 		if (desired > VMEM_HASHSIZE_MAX) {
1200 			desired = VMEM_HASHSIZE_MAX;
1201 		} else if (desired < VMEM_HASHSIZE_MIN) {
1202 			desired = VMEM_HASHSIZE_MIN;
1203 		}
1204 		if (desired > current * 2 || desired * 2 < current) {
1205 			vmem_rehash(vm, desired, VM_NOSLEEP);
1206 		}
1207 	}
1208 	mutex_exit(&vmem_list_lock);
1209 
1210 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1211 }
1212 
1213 static void
1214 vmem_rehash_all_kick(void *dummy)
1215 {
1216 
1217 	workqueue_enqueue(vmem_rehash_wq, &vmem_rehash_wk, NULL);
1218 }
1219 
1220 void
1221 vmem_rehash_start(void)
1222 {
1223 	int error;
1224 
1225 	error = workqueue_create(&vmem_rehash_wq, "vmem_rehash",
1226 	    vmem_rehash_all, NULL, PRI_VM, IPL_SOFTCLOCK, WQ_MPSAFE);
1227 	if (error) {
1228 		panic("%s: workqueue_create %d\n", __func__, error);
1229 	}
1230 	callout_init(&vmem_rehash_ch, CALLOUT_MPSAFE);
1231 	callout_setfunc(&vmem_rehash_ch, vmem_rehash_all_kick, NULL);
1232 
1233 	vmem_rehash_interval = hz * 10;
1234 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1235 }
1236 #endif /* defined(_KERNEL) */
1237 
1238 /* ---- debug */
1239 
1240 #if defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY)
1241 
1242 static void bt_dump(const bt_t *, void (*)(const char *, ...));
1243 
1244 static const char *
1245 bt_type_string(int type)
1246 {
1247 	static const char * const table[] = {
1248 		[BT_TYPE_BUSY] = "busy",
1249 		[BT_TYPE_FREE] = "free",
1250 		[BT_TYPE_SPAN] = "span",
1251 		[BT_TYPE_SPAN_STATIC] = "static span",
1252 	};
1253 
1254 	if (type >= __arraycount(table)) {
1255 		return "BOGUS";
1256 	}
1257 	return table[type];
1258 }
1259 
1260 static void
1261 bt_dump(const bt_t *bt, void (*pr)(const char *, ...))
1262 {
1263 
1264 	(*pr)("\t%p: %" PRIu64 ", %" PRIu64 ", %d(%s)\n",
1265 	    bt, (uint64_t)bt->bt_start, (uint64_t)bt->bt_size,
1266 	    bt->bt_type, bt_type_string(bt->bt_type));
1267 }
1268 
1269 static void
1270 vmem_dump(const vmem_t *vm , void (*pr)(const char *, ...))
1271 {
1272 	const bt_t *bt;
1273 	int i;
1274 
1275 	(*pr)("vmem %p '%s'\n", vm, vm->vm_name);
1276 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1277 		bt_dump(bt, pr);
1278 	}
1279 
1280 	for (i = 0; i < VMEM_MAXORDER; i++) {
1281 		const struct vmem_freelist *fl = &vm->vm_freelist[i];
1282 
1283 		if (LIST_EMPTY(fl)) {
1284 			continue;
1285 		}
1286 
1287 		(*pr)("freelist[%d]\n", i);
1288 		LIST_FOREACH(bt, fl, bt_freelist) {
1289 			bt_dump(bt, pr);
1290 		}
1291 	}
1292 }
1293 
1294 #endif /* defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY) */
1295 
1296 #if defined(DDB)
1297 static bt_t *
1298 vmem_whatis_lookup(vmem_t *vm, uintptr_t addr)
1299 {
1300 	bt_t *bt;
1301 
1302 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1303 		if (BT_ISSPAN_P(bt)) {
1304 			continue;
1305 		}
1306 		if (bt->bt_start <= addr && addr <= BT_END(bt)) {
1307 			return bt;
1308 		}
1309 	}
1310 
1311 	return NULL;
1312 }
1313 
1314 void
1315 vmem_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1316 {
1317 	vmem_t *vm;
1318 
1319 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1320 		bt_t *bt;
1321 
1322 		bt = vmem_whatis_lookup(vm, addr);
1323 		if (bt == NULL) {
1324 			continue;
1325 		}
1326 		(*pr)("%p is %p+%zu in VMEM '%s' (%s)\n",
1327 		    (void *)addr, (void *)bt->bt_start,
1328 		    (size_t)(addr - bt->bt_start), vm->vm_name,
1329 		    (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free");
1330 	}
1331 }
1332 
1333 void
1334 vmem_printall(const char *modif, void (*pr)(const char *, ...))
1335 {
1336 	const vmem_t *vm;
1337 
1338 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1339 		vmem_dump(vm, pr);
1340 	}
1341 }
1342 
1343 void
1344 vmem_print(uintptr_t addr, const char *modif, void (*pr)(const char *, ...))
1345 {
1346 	const vmem_t *vm = (const void *)addr;
1347 
1348 	vmem_dump(vm, pr);
1349 }
1350 #endif /* defined(DDB) */
1351 
1352 #if defined(_KERNEL)
1353 #define vmem_printf printf
1354 #else
1355 #include <stdio.h>
1356 #include <stdarg.h>
1357 
1358 static void
1359 vmem_printf(const char *fmt, ...)
1360 {
1361 	va_list ap;
1362 	va_start(ap, fmt);
1363 	vprintf(fmt, ap);
1364 	va_end(ap);
1365 }
1366 #endif
1367 
1368 #if defined(VMEM_SANITY)
1369 
1370 static bool
1371 vmem_check_sanity(vmem_t *vm)
1372 {
1373 	const bt_t *bt, *bt2;
1374 
1375 	KASSERT(vm != NULL);
1376 
1377 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1378 		if (bt->bt_start > BT_END(bt)) {
1379 			printf("corrupted tag\n");
1380 			bt_dump(bt, vmem_printf);
1381 			return false;
1382 		}
1383 	}
1384 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1385 		CIRCLEQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) {
1386 			if (bt == bt2) {
1387 				continue;
1388 			}
1389 			if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) {
1390 				continue;
1391 			}
1392 			if (bt->bt_start <= BT_END(bt2) &&
1393 			    bt2->bt_start <= BT_END(bt)) {
1394 				printf("overwrapped tags\n");
1395 				bt_dump(bt, vmem_printf);
1396 				bt_dump(bt2, vmem_printf);
1397 				return false;
1398 			}
1399 		}
1400 	}
1401 
1402 	return true;
1403 }
1404 
1405 static void
1406 vmem_check(vmem_t *vm)
1407 {
1408 
1409 	if (!vmem_check_sanity(vm)) {
1410 		panic("insanity vmem %p", vm);
1411 	}
1412 }
1413 
1414 #endif /* defined(VMEM_SANITY) */
1415 
1416 #if defined(UNITTEST)
1417 int
1418 main(void)
1419 {
1420 	int rc;
1421 	vmem_t *vm;
1422 	vmem_addr_t p;
1423 	struct reg {
1424 		vmem_addr_t p;
1425 		vmem_size_t sz;
1426 		bool x;
1427 	} *reg = NULL;
1428 	int nreg = 0;
1429 	int nalloc = 0;
1430 	int nfree = 0;
1431 	vmem_size_t total = 0;
1432 #if 1
1433 	vm_flag_t strat = VM_INSTANTFIT;
1434 #else
1435 	vm_flag_t strat = VM_BESTFIT;
1436 #endif
1437 
1438 	vm = vmem_create("test", 0, 0, 1, NULL, NULL, NULL, 0, VM_SLEEP,
1439 #ifdef _KERNEL
1440 	    IPL_NONE
1441 #else
1442 	    0
1443 #endif
1444 	    );
1445 	if (vm == NULL) {
1446 		printf("vmem_create\n");
1447 		exit(EXIT_FAILURE);
1448 	}
1449 	vmem_dump(vm, vmem_printf);
1450 
1451 	rc = vmem_add(vm, 0, 50, VM_SLEEP);
1452 	assert(rc == 0);
1453 	rc = vmem_add(vm, 100, 200, VM_SLEEP);
1454 	assert(rc == 0);
1455 	rc = vmem_add(vm, 2000, 1, VM_SLEEP);
1456 	assert(rc == 0);
1457 	rc = vmem_add(vm, 40000, 65536, VM_SLEEP);
1458 	assert(rc == 0);
1459 	rc = vmem_add(vm, 10000, 10000, VM_SLEEP);
1460 	assert(rc == 0);
1461 	rc = vmem_add(vm, 500, 1000, VM_SLEEP);
1462 	assert(rc == 0);
1463 	rc = vmem_add(vm, 0xffffff00, 0x100, VM_SLEEP);
1464 	assert(rc == 0);
1465 	rc = vmem_xalloc(vm, 0x101, 0, 0, 0,
1466 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1467 	assert(rc != 0);
1468 	rc = vmem_xalloc(vm, 50, 0, 0, 0, 0, 49, strat|VM_SLEEP, &p);
1469 	assert(rc == 0 && p == 0);
1470 	vmem_xfree(vm, p, 50);
1471 	rc = vmem_xalloc(vm, 25, 0, 0, 0, 0, 24, strat|VM_SLEEP, &p);
1472 	assert(rc == 0 && p == 0);
1473 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1474 	    0xffffff01, 0xffffffff, strat|VM_SLEEP, &p);
1475 	assert(rc != 0);
1476 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1477 	    0xffffff00, 0xfffffffe, strat|VM_SLEEP, &p);
1478 	assert(rc != 0);
1479 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1480 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1481 	assert(rc == 0);
1482 	vmem_dump(vm, vmem_printf);
1483 	for (;;) {
1484 		struct reg *r;
1485 		int t = rand() % 100;
1486 
1487 		if (t > 45) {
1488 			/* alloc */
1489 			vmem_size_t sz = rand() % 500 + 1;
1490 			bool x;
1491 			vmem_size_t align, phase, nocross;
1492 			vmem_addr_t minaddr, maxaddr;
1493 
1494 			if (t > 70) {
1495 				x = true;
1496 				/* XXX */
1497 				align = 1 << (rand() % 15);
1498 				phase = rand() % 65536;
1499 				nocross = 1 << (rand() % 15);
1500 				if (align <= phase) {
1501 					phase = 0;
1502 				}
1503 				if (VMEM_CROSS_P(phase, phase + sz - 1,
1504 				    nocross)) {
1505 					nocross = 0;
1506 				}
1507 				do {
1508 					minaddr = rand() % 50000;
1509 					maxaddr = rand() % 70000;
1510 				} while (minaddr > maxaddr);
1511 				printf("=== xalloc %" PRIu64
1512 				    " align=%" PRIu64 ", phase=%" PRIu64
1513 				    ", nocross=%" PRIu64 ", min=%" PRIu64
1514 				    ", max=%" PRIu64 "\n",
1515 				    (uint64_t)sz,
1516 				    (uint64_t)align,
1517 				    (uint64_t)phase,
1518 				    (uint64_t)nocross,
1519 				    (uint64_t)minaddr,
1520 				    (uint64_t)maxaddr);
1521 				rc = vmem_xalloc(vm, sz, align, phase, nocross,
1522 				    minaddr, maxaddr, strat|VM_SLEEP, &p);
1523 			} else {
1524 				x = false;
1525 				printf("=== alloc %" PRIu64 "\n", (uint64_t)sz);
1526 				rc = vmem_alloc(vm, sz, strat|VM_SLEEP, &p);
1527 			}
1528 			printf("-> %" PRIu64 "\n", (uint64_t)p);
1529 			vmem_dump(vm, vmem_printf);
1530 			if (rc != 0) {
1531 				if (x) {
1532 					continue;
1533 				}
1534 				break;
1535 			}
1536 			nreg++;
1537 			reg = realloc(reg, sizeof(*reg) * nreg);
1538 			r = &reg[nreg - 1];
1539 			r->p = p;
1540 			r->sz = sz;
1541 			r->x = x;
1542 			total += sz;
1543 			nalloc++;
1544 		} else if (nreg != 0) {
1545 			/* free */
1546 			r = &reg[rand() % nreg];
1547 			printf("=== free %" PRIu64 ", %" PRIu64 "\n",
1548 			    (uint64_t)r->p, (uint64_t)r->sz);
1549 			if (r->x) {
1550 				vmem_xfree(vm, r->p, r->sz);
1551 			} else {
1552 				vmem_free(vm, r->p, r->sz);
1553 			}
1554 			total -= r->sz;
1555 			vmem_dump(vm, vmem_printf);
1556 			*r = reg[nreg - 1];
1557 			nreg--;
1558 			nfree++;
1559 		}
1560 		printf("total=%" PRIu64 "\n", (uint64_t)total);
1561 	}
1562 	fprintf(stderr, "total=%" PRIu64 ", nalloc=%d, nfree=%d\n",
1563 	    (uint64_t)total, nalloc, nfree);
1564 	exit(EXIT_SUCCESS);
1565 }
1566 #endif /* defined(UNITTEST) */
1567