xref: /netbsd-src/sys/kern/subr_vmem.c (revision e5014a45d857e6639905eec7f40943a207fed007)
1 /*	$NetBSD: subr_vmem.c,v 1.115 2023/12/03 19:34:08 thorpej 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  * locking & the boundary tag pool:
36  * - 	A pool(9) is used for vmem boundary tags
37  * - 	During a pool get call the global vmem_btag_refill_lock is taken,
38  *	to serialize access to the allocation reserve, but no other
39  *	vmem arena locks.
40  * -	During pool_put calls no vmem mutexes are locked.
41  * - 	pool_drain doesn't hold the pool's mutex while releasing memory to
42  * 	its backing therefore no interference with any vmem mutexes.
43  * -	The boundary tag pool is forced to put page headers into pool pages
44  *  	(PR_PHINPAGE) and not off page to avoid pool recursion.
45  *  	(due to sizeof(bt_t) it should be the case anyway)
46  */
47 
48 #include <sys/cdefs.h>
49 __KERNEL_RCSID(0, "$NetBSD: subr_vmem.c,v 1.115 2023/12/03 19:34:08 thorpej Exp $");
50 
51 #if defined(_KERNEL) && defined(_KERNEL_OPT)
52 #include "opt_ddb.h"
53 #endif /* defined(_KERNEL) && defined(_KERNEL_OPT) */
54 
55 #include <sys/param.h>
56 #include <sys/hash.h>
57 #include <sys/queue.h>
58 #include <sys/bitops.h>
59 
60 #if defined(_KERNEL)
61 #include <sys/systm.h>
62 #include <sys/kernel.h>	/* hz */
63 #include <sys/callout.h>
64 #include <sys/kmem.h>
65 #include <sys/pool.h>
66 #include <sys/vmem.h>
67 #include <sys/vmem_impl.h>
68 #include <sys/workqueue.h>
69 #include <sys/atomic.h>
70 #include <uvm/uvm.h>
71 #include <uvm/uvm_extern.h>
72 #include <uvm/uvm_km.h>
73 #include <uvm/uvm_page.h>
74 #include <uvm/uvm_pdaemon.h>
75 #else /* defined(_KERNEL) */
76 #include <stdio.h>
77 #include <errno.h>
78 #include <assert.h>
79 #include <stdlib.h>
80 #include <string.h>
81 #include "../sys/vmem.h"
82 #include "../sys/vmem_impl.h"
83 #endif /* defined(_KERNEL) */
84 
85 
86 #if defined(_KERNEL)
87 #include <sys/evcnt.h>
88 #define VMEM_EVCNT_DEFINE(name) \
89 struct evcnt vmem_evcnt_##name = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, \
90     "vmem", #name); \
91 EVCNT_ATTACH_STATIC(vmem_evcnt_##name);
92 #define VMEM_EVCNT_INCR(ev)	vmem_evcnt_##ev.ev_count++
93 #define VMEM_EVCNT_DECR(ev)	vmem_evcnt_##ev.ev_count--
94 
95 VMEM_EVCNT_DEFINE(static_bt_count)
96 VMEM_EVCNT_DEFINE(static_bt_inuse)
97 
98 #define	VMEM_CONDVAR_INIT(vm, wchan)	cv_init(&vm->vm_cv, wchan)
99 #define	VMEM_CONDVAR_DESTROY(vm)	cv_destroy(&vm->vm_cv)
100 #define	VMEM_CONDVAR_WAIT(vm)		cv_wait(&vm->vm_cv, &vm->vm_lock)
101 #define	VMEM_CONDVAR_BROADCAST(vm)	cv_broadcast(&vm->vm_cv)
102 
103 #else /* defined(_KERNEL) */
104 
105 #define VMEM_EVCNT_INCR(ev)	/* nothing */
106 #define VMEM_EVCNT_DECR(ev)	/* nothing */
107 
108 #define	VMEM_CONDVAR_INIT(vm, wchan)	/* nothing */
109 #define	VMEM_CONDVAR_DESTROY(vm)	/* nothing */
110 #define	VMEM_CONDVAR_WAIT(vm)		/* nothing */
111 #define	VMEM_CONDVAR_BROADCAST(vm)	/* nothing */
112 
113 #define	UNITTEST
114 #define	KASSERT(a)		assert(a)
115 #define	KASSERTMSG(a, m, ...)	assert(a)
116 #define	mutex_init(a, b, c)	/* nothing */
117 #define	mutex_destroy(a)	/* nothing */
118 #define	mutex_enter(a)		/* nothing */
119 #define	mutex_tryenter(a)	true
120 #define	mutex_exit(a)		/* nothing */
121 #define	mutex_owned(a)		true
122 #define	ASSERT_SLEEPABLE()	/* nothing */
123 #define	panic(...)		printf(__VA_ARGS__); abort()
124 #endif /* defined(_KERNEL) */
125 
126 #if defined(VMEM_SANITY)
127 static void vmem_check(vmem_t *);
128 #else /* defined(VMEM_SANITY) */
129 #define vmem_check(vm)	/* nothing */
130 #endif /* defined(VMEM_SANITY) */
131 
132 #define	VMEM_HASHSIZE_MIN	1	/* XXX */
133 #define	VMEM_HASHSIZE_MAX	65536	/* XXX */
134 #define	VMEM_HASHSIZE_INIT	1
135 
136 #define	VM_FITMASK	(VM_BESTFIT | VM_INSTANTFIT)
137 
138 #if defined(_KERNEL)
139 static bool vmem_bootstrapped = false;
140 static kmutex_t vmem_list_lock;
141 static LIST_HEAD(, vmem) vmem_list = LIST_HEAD_INITIALIZER(vmem_list);
142 #endif /* defined(_KERNEL) */
143 
144 /* ---- misc */
145 
146 #define	VMEM_LOCK(vm)		mutex_enter(&(vm)->vm_lock)
147 #define	VMEM_TRYLOCK(vm)	mutex_tryenter(&(vm)->vm_lock)
148 #define	VMEM_UNLOCK(vm)		mutex_exit(&(vm)->vm_lock)
149 #define	VMEM_LOCK_INIT(vm, ipl)	mutex_init(&(vm)->vm_lock, MUTEX_DEFAULT, (ipl))
150 #define	VMEM_LOCK_DESTROY(vm)	mutex_destroy(&(vm)->vm_lock)
151 #define	VMEM_ASSERT_LOCKED(vm)	KASSERT(mutex_owned(&(vm)->vm_lock))
152 
153 #define	VMEM_ALIGNUP(addr, align) \
154 	(-(-(addr) & -(align)))
155 
156 #define	VMEM_CROSS_P(addr1, addr2, boundary) \
157 	((((addr1) ^ (addr2)) & -(boundary)) != 0)
158 
159 #define	ORDER2SIZE(order)	((vmem_size_t)1 << (order))
160 #define	SIZE2ORDER(size)	((int)ilog2(size))
161 
162 static void
163 vmem_kick_pdaemon(void)
164 {
165 #if defined(_KERNEL)
166 	uvm_kick_pdaemon();
167 #endif
168 }
169 
170 static void vmem_xfree_bt(vmem_t *, bt_t *);
171 
172 #if !defined(_KERNEL)
173 #define	xmalloc(sz, flags)	malloc(sz)
174 #define	xfree(p, sz)		free(p)
175 #define	bt_alloc(vm, flags)	malloc(sizeof(bt_t))
176 #define	bt_free(vm, bt)		free(bt)
177 #define	bt_freetrim(vm, l)	/* nothing */
178 #else /* defined(_KERNEL) */
179 
180 #define	xmalloc(sz, flags) \
181     kmem_alloc(sz, ((flags) & VM_SLEEP) ? KM_SLEEP : KM_NOSLEEP);
182 #define	xfree(p, sz)		kmem_free(p, sz);
183 
184 /*
185  * BT_RESERVE calculation:
186  * we allocate memory for boundary tags with vmem; therefore we have
187  * to keep a reserve of bts used to allocated memory for bts.
188  * This reserve is 4 for each arena involved in allocating vmems memory.
189  * BT_MAXFREE: don't cache excessive counts of bts in arenas
190  */
191 #define STATIC_BT_COUNT 200
192 #define BT_MINRESERVE 4
193 #define BT_MAXFREE 64
194 
195 static struct vmem_btag static_bts[STATIC_BT_COUNT];
196 static int static_bt_count = STATIC_BT_COUNT;
197 
198 static struct vmem kmem_va_meta_arena_store;
199 vmem_t *kmem_va_meta_arena;
200 static struct vmem kmem_meta_arena_store;
201 vmem_t *kmem_meta_arena = NULL;
202 
203 static kmutex_t vmem_btag_refill_lock;
204 static kmutex_t vmem_btag_lock;
205 static LIST_HEAD(, vmem_btag) vmem_btag_freelist;
206 static size_t vmem_btag_freelist_count = 0;
207 static struct pool vmem_btag_pool;
208 static bool vmem_btag_pool_initialized __read_mostly;
209 
210 /* ---- boundary tag */
211 
212 static int bt_refill(vmem_t *vm);
213 static int bt_refill_locked(vmem_t *vm);
214 
215 static void *
216 pool_page_alloc_vmem_meta(struct pool *pp, int flags)
217 {
218 	const vm_flag_t vflags = (flags & PR_WAITOK) ? VM_SLEEP: VM_NOSLEEP;
219 	vmem_addr_t va;
220 	int ret;
221 
222 	ret = vmem_alloc(kmem_meta_arena, pp->pr_alloc->pa_pagesz,
223 	    (vflags & ~VM_FITMASK) | VM_INSTANTFIT | VM_POPULATING, &va);
224 
225 	return ret ? NULL : (void *)va;
226 }
227 
228 static void
229 pool_page_free_vmem_meta(struct pool *pp, void *v)
230 {
231 
232 	vmem_free(kmem_meta_arena, (vmem_addr_t)v, pp->pr_alloc->pa_pagesz);
233 }
234 
235 /* allocator for vmem-pool metadata */
236 struct pool_allocator pool_allocator_vmem_meta = {
237 	.pa_alloc = pool_page_alloc_vmem_meta,
238 	.pa_free = pool_page_free_vmem_meta,
239 	.pa_pagesz = 0
240 };
241 
242 static int
243 bt_refill_locked(vmem_t *vm)
244 {
245 	bt_t *bt;
246 
247 	VMEM_ASSERT_LOCKED(vm);
248 
249 	if (vm->vm_nfreetags > BT_MINRESERVE) {
250 		return 0;
251 	}
252 
253 	mutex_enter(&vmem_btag_lock);
254 	while (!LIST_EMPTY(&vmem_btag_freelist) &&
255 	    vm->vm_nfreetags <= BT_MINRESERVE &&
256 	    (vm->vm_flags & VM_PRIVTAGS) == 0) {
257 		bt = LIST_FIRST(&vmem_btag_freelist);
258 		LIST_REMOVE(bt, bt_freelist);
259 		bt->bt_flags = 0;
260 		LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
261 		vm->vm_nfreetags++;
262 		vmem_btag_freelist_count--;
263 		VMEM_EVCNT_INCR(static_bt_inuse);
264 	}
265 	mutex_exit(&vmem_btag_lock);
266 
267 	while (vm->vm_nfreetags <= BT_MINRESERVE) {
268 		VMEM_UNLOCK(vm);
269 		KASSERT(vmem_btag_pool_initialized);
270 		mutex_enter(&vmem_btag_refill_lock);
271 		bt = pool_get(&vmem_btag_pool, PR_NOWAIT);
272 		mutex_exit(&vmem_btag_refill_lock);
273 		VMEM_LOCK(vm);
274 		if (bt == NULL)
275 			break;
276 		bt->bt_flags = 0;
277 		LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
278 		vm->vm_nfreetags++;
279 	}
280 
281 	if (vm->vm_nfreetags <= BT_MINRESERVE) {
282 		return ENOMEM;
283 	}
284 
285 	if (kmem_meta_arena != NULL) {
286 		VMEM_UNLOCK(vm);
287 		(void)bt_refill(kmem_arena);
288 		(void)bt_refill(kmem_va_meta_arena);
289 		(void)bt_refill(kmem_meta_arena);
290 		VMEM_LOCK(vm);
291 	}
292 
293 	return 0;
294 }
295 
296 static int
297 bt_refill(vmem_t *vm)
298 {
299 	int rv;
300 
301 	VMEM_LOCK(vm);
302 	rv = bt_refill_locked(vm);
303 	VMEM_UNLOCK(vm);
304 	return rv;
305 }
306 
307 static bt_t *
308 bt_alloc(vmem_t *vm, vm_flag_t flags)
309 {
310 	bt_t *bt;
311 
312 	VMEM_ASSERT_LOCKED(vm);
313 
314 	while (vm->vm_nfreetags <= BT_MINRESERVE && (flags & VM_POPULATING) == 0) {
315 		if (bt_refill_locked(vm)) {
316 			if ((flags & VM_NOSLEEP) != 0) {
317 				return NULL;
318 			}
319 
320 			/*
321 			 * It would be nice to wait for something specific here
322 			 * but there are multiple ways that a retry could
323 			 * succeed and we can't wait for multiple things
324 			 * simultaneously.  So we'll just sleep for an arbitrary
325 			 * short period of time and retry regardless.
326 			 * This should be a very rare case.
327 			 */
328 
329 			vmem_kick_pdaemon();
330 			kpause("btalloc", false, 1, &vm->vm_lock);
331 		}
332 	}
333 	bt = LIST_FIRST(&vm->vm_freetags);
334 	LIST_REMOVE(bt, bt_freelist);
335 	vm->vm_nfreetags--;
336 
337 	return bt;
338 }
339 
340 static void
341 bt_free(vmem_t *vm, bt_t *bt)
342 {
343 
344 	VMEM_ASSERT_LOCKED(vm);
345 
346 	LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
347 	vm->vm_nfreetags++;
348 }
349 
350 static void
351 bt_freetrim(vmem_t *vm, int freelimit)
352 {
353 	bt_t *bt, *next_bt;
354 	LIST_HEAD(, vmem_btag) tofree;
355 
356 	VMEM_ASSERT_LOCKED(vm);
357 
358 	LIST_INIT(&tofree);
359 
360 	LIST_FOREACH_SAFE(bt, &vm->vm_freetags, bt_freelist, next_bt) {
361 		if (vm->vm_nfreetags <= freelimit) {
362 			break;
363 		}
364 		if (bt->bt_flags & BT_F_PRIVATE) {
365 			continue;
366 		}
367 		LIST_REMOVE(bt, bt_freelist);
368 		vm->vm_nfreetags--;
369 		if (bt >= static_bts
370 		    && bt < &static_bts[STATIC_BT_COUNT]) {
371 			mutex_enter(&vmem_btag_lock);
372 			LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
373 			vmem_btag_freelist_count++;
374 			mutex_exit(&vmem_btag_lock);
375 			VMEM_EVCNT_DECR(static_bt_inuse);
376 		} else {
377 			LIST_INSERT_HEAD(&tofree, bt, bt_freelist);
378 		}
379 	}
380 
381 	VMEM_UNLOCK(vm);
382 	while (!LIST_EMPTY(&tofree)) {
383 		bt = LIST_FIRST(&tofree);
384 		LIST_REMOVE(bt, bt_freelist);
385 		pool_put(&vmem_btag_pool, bt);
386 	}
387 }
388 
389 /*
390  * Add private boundary tags (statically-allocated by the caller)
391  * to a vmem arena's free tag list.
392  */
393 void
394 vmem_add_bts(vmem_t *vm, struct vmem_btag *bts, unsigned int nbts)
395 {
396 	VMEM_LOCK(vm);
397 	while (nbts != 0) {
398 		bts->bt_flags = BT_F_PRIVATE;
399 		LIST_INSERT_HEAD(&vm->vm_freetags, bts, bt_freelist);
400 		vm->vm_nfreetags++;
401 		bts++;
402 		nbts--;
403 	}
404 	VMEM_UNLOCK(vm);
405 }
406 #endif	/* defined(_KERNEL) */
407 
408 /*
409  * freelist[0] ... [1, 1]
410  * freelist[1] ... [2, 3]
411  * freelist[2] ... [4, 7]
412  * freelist[3] ... [8, 15]
413  *  :
414  * freelist[n] ... [(1 << n), (1 << (n + 1)) - 1]
415  *  :
416  */
417 
418 static struct vmem_freelist *
419 bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
420 {
421 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
422 	const int idx = SIZE2ORDER(qsize);
423 
424 	KASSERT(size != 0);
425 	KASSERT(qsize != 0);
426 	KASSERT((size & vm->vm_quantum_mask) == 0);
427 	KASSERT(idx >= 0);
428 	KASSERT(idx < VMEM_MAXORDER);
429 
430 	return &vm->vm_freelist[idx];
431 }
432 
433 /*
434  * bt_freehead_toalloc: return the freelist for the given size and allocation
435  * strategy.
436  *
437  * for VM_INSTANTFIT, return the list in which any blocks are large enough
438  * for the requested size.  otherwise, return the list which can have blocks
439  * large enough for the requested size.
440  */
441 
442 static struct vmem_freelist *
443 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, vm_flag_t strat)
444 {
445 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
446 	int idx = SIZE2ORDER(qsize);
447 
448 	KASSERT(size != 0);
449 	KASSERT(qsize != 0);
450 	KASSERT((size & vm->vm_quantum_mask) == 0);
451 
452 	if (strat == VM_INSTANTFIT && ORDER2SIZE(idx) != qsize) {
453 		idx++;
454 		/* check too large request? */
455 	}
456 	KASSERT(idx >= 0);
457 	KASSERT(idx < VMEM_MAXORDER);
458 
459 	return &vm->vm_freelist[idx];
460 }
461 
462 /* ---- boundary tag hash */
463 
464 static struct vmem_hashlist *
465 bt_hashhead(vmem_t *vm, vmem_addr_t addr)
466 {
467 	struct vmem_hashlist *list;
468 	unsigned int hash;
469 
470 	hash = hash32_buf(&addr, sizeof(addr), HASH32_BUF_INIT);
471 	list = &vm->vm_hashlist[hash & vm->vm_hashmask];
472 
473 	return list;
474 }
475 
476 static bt_t *
477 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
478 {
479 	struct vmem_hashlist *list;
480 	bt_t *bt;
481 
482 	list = bt_hashhead(vm, addr);
483 	LIST_FOREACH(bt, list, bt_hashlist) {
484 		if (bt->bt_start == addr) {
485 			break;
486 		}
487 	}
488 
489 	return bt;
490 }
491 
492 static void
493 bt_rembusy(vmem_t *vm, bt_t *bt)
494 {
495 
496 	KASSERT(vm->vm_nbusytag > 0);
497 	vm->vm_inuse -= bt->bt_size;
498 	vm->vm_nbusytag--;
499 	LIST_REMOVE(bt, bt_hashlist);
500 }
501 
502 static void
503 bt_insbusy(vmem_t *vm, bt_t *bt)
504 {
505 	struct vmem_hashlist *list;
506 
507 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
508 
509 	list = bt_hashhead(vm, bt->bt_start);
510 	LIST_INSERT_HEAD(list, bt, bt_hashlist);
511 	if (++vm->vm_nbusytag > vm->vm_maxbusytag) {
512 		vm->vm_maxbusytag = vm->vm_nbusytag;
513 	}
514 	vm->vm_inuse += bt->bt_size;
515 }
516 
517 /* ---- boundary tag list */
518 
519 static void
520 bt_remseg(vmem_t *vm, bt_t *bt)
521 {
522 
523 	TAILQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
524 }
525 
526 static void
527 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
528 {
529 
530 	TAILQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
531 }
532 
533 static void
534 bt_insseg_tail(vmem_t *vm, bt_t *bt)
535 {
536 
537 	TAILQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
538 }
539 
540 static void
541 bt_remfree(vmem_t *vm, bt_t *bt)
542 {
543 
544 	KASSERT(bt->bt_type == BT_TYPE_FREE);
545 
546 	LIST_REMOVE(bt, bt_freelist);
547 }
548 
549 static void
550 bt_insfree(vmem_t *vm, bt_t *bt)
551 {
552 	struct vmem_freelist *list;
553 
554 	list = bt_freehead_tofree(vm, bt->bt_size);
555 	LIST_INSERT_HEAD(list, bt, bt_freelist);
556 }
557 
558 /* ---- vmem internal functions */
559 
560 #if defined(QCACHE)
561 static inline vm_flag_t
562 prf_to_vmf(int prflags)
563 {
564 	vm_flag_t vmflags;
565 
566 	KASSERT((prflags & ~(PR_LIMITFAIL | PR_WAITOK | PR_NOWAIT)) == 0);
567 	if ((prflags & PR_WAITOK) != 0) {
568 		vmflags = VM_SLEEP;
569 	} else {
570 		vmflags = VM_NOSLEEP;
571 	}
572 	return vmflags;
573 }
574 
575 static inline int
576 vmf_to_prf(vm_flag_t vmflags)
577 {
578 	int prflags;
579 
580 	if ((vmflags & VM_SLEEP) != 0) {
581 		prflags = PR_WAITOK;
582 	} else {
583 		prflags = PR_NOWAIT;
584 	}
585 	return prflags;
586 }
587 
588 static size_t
589 qc_poolpage_size(size_t qcache_max)
590 {
591 	int i;
592 
593 	for (i = 0; ORDER2SIZE(i) <= qcache_max * 3; i++) {
594 		/* nothing */
595 	}
596 	return ORDER2SIZE(i);
597 }
598 
599 static void *
600 qc_poolpage_alloc(struct pool *pool, int prflags)
601 {
602 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
603 	vmem_t *vm = qc->qc_vmem;
604 	vmem_addr_t addr;
605 
606 	if (vmem_alloc(vm, pool->pr_alloc->pa_pagesz,
607 	    prf_to_vmf(prflags) | VM_INSTANTFIT, &addr) != 0)
608 		return NULL;
609 	return (void *)addr;
610 }
611 
612 static void
613 qc_poolpage_free(struct pool *pool, void *addr)
614 {
615 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
616 	vmem_t *vm = qc->qc_vmem;
617 
618 	vmem_free(vm, (vmem_addr_t)addr, pool->pr_alloc->pa_pagesz);
619 }
620 
621 static void
622 qc_init(vmem_t *vm, size_t qcache_max, int ipl)
623 {
624 	qcache_t *prevqc;
625 	struct pool_allocator *pa;
626 	int qcache_idx_max;
627 	int i;
628 
629 	KASSERT((qcache_max & vm->vm_quantum_mask) == 0);
630 	if (qcache_max > (VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift)) {
631 		qcache_max = VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift;
632 	}
633 	vm->vm_qcache_max = qcache_max;
634 	pa = &vm->vm_qcache_allocator;
635 	memset(pa, 0, sizeof(*pa));
636 	pa->pa_alloc = qc_poolpage_alloc;
637 	pa->pa_free = qc_poolpage_free;
638 	pa->pa_pagesz = qc_poolpage_size(qcache_max);
639 
640 	qcache_idx_max = qcache_max >> vm->vm_quantum_shift;
641 	prevqc = NULL;
642 	for (i = qcache_idx_max; i > 0; i--) {
643 		qcache_t *qc = &vm->vm_qcache_store[i - 1];
644 		size_t size = i << vm->vm_quantum_shift;
645 		pool_cache_t pc;
646 
647 		qc->qc_vmem = vm;
648 		snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu",
649 		    vm->vm_name, size);
650 
651 		pc = pool_cache_init(size,
652 		    ORDER2SIZE(vm->vm_quantum_shift), 0,
653 		    PR_NOALIGN | PR_NOTOUCH | PR_RECURSIVE /* XXX */,
654 		    qc->qc_name, pa, ipl, NULL, NULL, NULL);
655 
656 		KASSERT(pc);
657 
658 		qc->qc_cache = pc;
659 		KASSERT(qc->qc_cache != NULL);	/* XXX */
660 		if (prevqc != NULL &&
661 		    qc->qc_cache->pc_pool.pr_itemsperpage ==
662 		    prevqc->qc_cache->pc_pool.pr_itemsperpage) {
663 			pool_cache_destroy(qc->qc_cache);
664 			vm->vm_qcache[i - 1] = prevqc;
665 			continue;
666 		}
667 		qc->qc_cache->pc_pool.pr_qcache = qc;
668 		vm->vm_qcache[i - 1] = qc;
669 		prevqc = qc;
670 	}
671 }
672 
673 static void
674 qc_destroy(vmem_t *vm)
675 {
676 	const qcache_t *prevqc;
677 	int i;
678 	int qcache_idx_max;
679 
680 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
681 	prevqc = NULL;
682 	for (i = 0; i < qcache_idx_max; i++) {
683 		qcache_t *qc = vm->vm_qcache[i];
684 
685 		if (prevqc == qc) {
686 			continue;
687 		}
688 		pool_cache_destroy(qc->qc_cache);
689 		prevqc = qc;
690 	}
691 }
692 #endif
693 
694 #if defined(_KERNEL)
695 static void
696 vmem_bootstrap(void)
697 {
698 
699 	mutex_init(&vmem_list_lock, MUTEX_DEFAULT, IPL_NONE);
700 	mutex_init(&vmem_btag_lock, MUTEX_DEFAULT, IPL_VM);
701 	mutex_init(&vmem_btag_refill_lock, MUTEX_DEFAULT, IPL_VM);
702 
703 	while (static_bt_count-- > 0) {
704 		bt_t *bt = &static_bts[static_bt_count];
705 		LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
706 		VMEM_EVCNT_INCR(static_bt_count);
707 		vmem_btag_freelist_count++;
708 	}
709 	vmem_bootstrapped = TRUE;
710 }
711 
712 void
713 vmem_subsystem_init(vmem_t *vm)
714 {
715 
716 	kmem_va_meta_arena = vmem_init(&kmem_va_meta_arena_store, "vmem-va",
717 	    0, 0, PAGE_SIZE, vmem_alloc, vmem_free, vm,
718 	    0, VM_NOSLEEP | VM_BOOTSTRAP | VM_LARGEIMPORT,
719 	    IPL_VM);
720 
721 	kmem_meta_arena = vmem_init(&kmem_meta_arena_store, "vmem-meta",
722 	    0, 0, PAGE_SIZE,
723 	    uvm_km_kmem_alloc, uvm_km_kmem_free, kmem_va_meta_arena,
724 	    0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM);
725 
726 	pool_init(&vmem_btag_pool, sizeof(bt_t), coherency_unit, 0,
727 	    PR_PHINPAGE, "vmembt", &pool_allocator_vmem_meta, IPL_VM);
728 	vmem_btag_pool_initialized = true;
729 }
730 #endif /* defined(_KERNEL) */
731 
732 static int
733 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags,
734     int spanbttype)
735 {
736 	bt_t *btspan;
737 	bt_t *btfree;
738 
739 	VMEM_ASSERT_LOCKED(vm);
740 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
741 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
742 	KASSERT(spanbttype == BT_TYPE_SPAN ||
743 	    spanbttype == BT_TYPE_SPAN_STATIC);
744 
745 	btspan = bt_alloc(vm, flags);
746 	if (btspan == NULL) {
747 		return ENOMEM;
748 	}
749 	btfree = bt_alloc(vm, flags);
750 	if (btfree == NULL) {
751 		bt_free(vm, btspan);
752 		return ENOMEM;
753 	}
754 
755 	btspan->bt_type = spanbttype;
756 	btspan->bt_start = addr;
757 	btspan->bt_size = size;
758 
759 	btfree->bt_type = BT_TYPE_FREE;
760 	btfree->bt_start = addr;
761 	btfree->bt_size = size;
762 
763 	bt_insseg_tail(vm, btspan);
764 	bt_insseg(vm, btfree, btspan);
765 	bt_insfree(vm, btfree);
766 	vm->vm_size += size;
767 
768 	return 0;
769 }
770 
771 static void
772 vmem_destroy1(vmem_t *vm)
773 {
774 
775 #if defined(QCACHE)
776 	qc_destroy(vm);
777 #endif /* defined(QCACHE) */
778 	VMEM_LOCK(vm);
779 
780 	for (int i = 0; i < vm->vm_hashsize; i++) {
781 		bt_t *bt;
782 
783 		while ((bt = LIST_FIRST(&vm->vm_hashlist[i])) != NULL) {
784 			KASSERT(bt->bt_type == BT_TYPE_SPAN_STATIC);
785 			LIST_REMOVE(bt, bt_hashlist);
786 			bt_free(vm, bt);
787 		}
788 	}
789 
790 	/* bt_freetrim() drops the lock. */
791 	bt_freetrim(vm, 0);
792 	if (vm->vm_hashlist != &vm->vm_hash0) {
793 		xfree(vm->vm_hashlist,
794 		    sizeof(struct vmem_hashlist) * vm->vm_hashsize);
795 	}
796 
797 	VMEM_CONDVAR_DESTROY(vm);
798 	VMEM_LOCK_DESTROY(vm);
799 	xfree(vm, sizeof(*vm));
800 }
801 
802 static int
803 vmem_import(vmem_t *vm, vmem_size_t size, vm_flag_t flags)
804 {
805 	vmem_addr_t addr;
806 	int rc;
807 
808 	VMEM_ASSERT_LOCKED(vm);
809 
810 	if (vm->vm_importfn == NULL) {
811 		return EINVAL;
812 	}
813 
814 	if (vm->vm_flags & VM_LARGEIMPORT) {
815 		size *= 16;
816 	}
817 
818 	VMEM_UNLOCK(vm);
819 	if (vm->vm_flags & VM_XIMPORT) {
820 		rc = __FPTRCAST(vmem_ximport_t *, vm->vm_importfn)(vm->vm_arg,
821 		    size, &size, flags, &addr);
822 	} else {
823 		rc = (vm->vm_importfn)(vm->vm_arg, size, flags, &addr);
824 	}
825 	VMEM_LOCK(vm);
826 
827 	if (rc) {
828 		return ENOMEM;
829 	}
830 
831 	if (vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN) != 0) {
832 		VMEM_UNLOCK(vm);
833 		(*vm->vm_releasefn)(vm->vm_arg, addr, size);
834 		VMEM_LOCK(vm);
835 		return ENOMEM;
836 	}
837 
838 	return 0;
839 }
840 
841 #if defined(_KERNEL)
842 static int
843 vmem_rehash(vmem_t *vm, size_t newhashsize, vm_flag_t flags)
844 {
845 	bt_t *bt;
846 	int i;
847 	struct vmem_hashlist *newhashlist;
848 	struct vmem_hashlist *oldhashlist;
849 	size_t oldhashsize;
850 
851 	KASSERT(newhashsize > 0);
852 
853 	/* Round hash size up to a power of 2. */
854 	newhashsize = 1 << (ilog2(newhashsize) + 1);
855 
856 	newhashlist =
857 	    xmalloc(sizeof(struct vmem_hashlist) * newhashsize, flags);
858 	if (newhashlist == NULL) {
859 		return ENOMEM;
860 	}
861 	for (i = 0; i < newhashsize; i++) {
862 		LIST_INIT(&newhashlist[i]);
863 	}
864 
865 	VMEM_LOCK(vm);
866 	/* Decay back to a small hash slowly. */
867 	if (vm->vm_maxbusytag >= 2) {
868 		vm->vm_maxbusytag = vm->vm_maxbusytag / 2 - 1;
869 		if (vm->vm_nbusytag > vm->vm_maxbusytag) {
870 			vm->vm_maxbusytag = vm->vm_nbusytag;
871 		}
872 	} else {
873 		vm->vm_maxbusytag = vm->vm_nbusytag;
874 	}
875 	oldhashlist = vm->vm_hashlist;
876 	oldhashsize = vm->vm_hashsize;
877 	vm->vm_hashlist = newhashlist;
878 	vm->vm_hashsize = newhashsize;
879 	vm->vm_hashmask = newhashsize - 1;
880 	if (oldhashlist == NULL) {
881 		VMEM_UNLOCK(vm);
882 		return 0;
883 	}
884 	for (i = 0; i < oldhashsize; i++) {
885 		while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
886 			bt_rembusy(vm, bt); /* XXX */
887 			bt_insbusy(vm, bt);
888 		}
889 	}
890 	VMEM_UNLOCK(vm);
891 
892 	if (oldhashlist != &vm->vm_hash0) {
893 		xfree(oldhashlist,
894 		    sizeof(struct vmem_hashlist) * oldhashsize);
895 	}
896 
897 	return 0;
898 }
899 #endif /* _KERNEL */
900 
901 /*
902  * vmem_fit: check if a bt can satisfy the given restrictions.
903  *
904  * it's a caller's responsibility to ensure the region is big enough
905  * before calling us.
906  */
907 
908 static int
909 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align,
910     vmem_size_t phase, vmem_size_t nocross,
911     vmem_addr_t minaddr, vmem_addr_t maxaddr, vmem_addr_t *addrp)
912 {
913 	vmem_addr_t start;
914 	vmem_addr_t end;
915 
916 	KASSERT(size > 0);
917 	KASSERT(bt->bt_size >= size); /* caller's responsibility */
918 
919 	/*
920 	 * XXX assumption: vmem_addr_t and vmem_size_t are
921 	 * unsigned integer of the same size.
922 	 */
923 
924 	start = bt->bt_start;
925 	if (start < minaddr) {
926 		start = minaddr;
927 	}
928 	end = BT_END(bt);
929 	if (end > maxaddr) {
930 		end = maxaddr;
931 	}
932 	if (start > end) {
933 		return ENOMEM;
934 	}
935 
936 	start = VMEM_ALIGNUP(start - phase, align) + phase;
937 	if (start < bt->bt_start) {
938 		start += align;
939 	}
940 	if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
941 		KASSERT(align < nocross);
942 		start = VMEM_ALIGNUP(start - phase, nocross) + phase;
943 	}
944 	if (start <= end && end - start >= size - 1) {
945 		KASSERT((start & (align - 1)) == phase);
946 		KASSERT(!VMEM_CROSS_P(start, start + size - 1, nocross));
947 		KASSERT(minaddr <= start);
948 		KASSERT(maxaddr == 0 || start + size - 1 <= maxaddr);
949 		KASSERT(bt->bt_start <= start);
950 		KASSERT(BT_END(bt) - start >= size - 1);
951 		*addrp = start;
952 		return 0;
953 	}
954 	return ENOMEM;
955 }
956 
957 /* ---- vmem API */
958 
959 /*
960  * vmem_init: creates a vmem arena.
961  */
962 
963 vmem_t *
964 vmem_init(vmem_t *vm, const char *name,
965     vmem_addr_t base, vmem_size_t size, vmem_size_t quantum,
966     vmem_import_t *importfn, vmem_release_t *releasefn,
967     vmem_t *arg, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
968 {
969 	int i;
970 
971 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
972 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
973 	KASSERT(quantum > 0);
974 
975 #if defined(_KERNEL)
976 	/* XXX: SMP, we get called early... */
977 	if (!vmem_bootstrapped) {
978 		vmem_bootstrap();
979 	}
980 #endif /* defined(_KERNEL) */
981 
982 	if (vm == NULL) {
983 		vm = xmalloc(sizeof(*vm), flags);
984 	}
985 	if (vm == NULL) {
986 		return NULL;
987 	}
988 
989 	VMEM_CONDVAR_INIT(vm, "vmem");
990 	VMEM_LOCK_INIT(vm, ipl);
991 	vm->vm_flags = flags;
992 	vm->vm_nfreetags = 0;
993 	LIST_INIT(&vm->vm_freetags);
994 	strlcpy(vm->vm_name, name, sizeof(vm->vm_name));
995 	vm->vm_quantum_mask = quantum - 1;
996 	vm->vm_quantum_shift = SIZE2ORDER(quantum);
997 	KASSERT(ORDER2SIZE(vm->vm_quantum_shift) == quantum);
998 	vm->vm_importfn = importfn;
999 	vm->vm_releasefn = releasefn;
1000 	vm->vm_arg = arg;
1001 	vm->vm_nbusytag = 0;
1002 	vm->vm_maxbusytag = 0;
1003 	vm->vm_size = 0;
1004 	vm->vm_inuse = 0;
1005 #if defined(QCACHE)
1006 	qc_init(vm, qcache_max, ipl);
1007 #endif /* defined(QCACHE) */
1008 
1009 	TAILQ_INIT(&vm->vm_seglist);
1010 	for (i = 0; i < VMEM_MAXORDER; i++) {
1011 		LIST_INIT(&vm->vm_freelist[i]);
1012 	}
1013 	memset(&vm->vm_hash0, 0, sizeof(vm->vm_hash0));
1014 	vm->vm_hashsize = 1;
1015 	vm->vm_hashmask = vm->vm_hashsize - 1;
1016 	vm->vm_hashlist = &vm->vm_hash0;
1017 
1018 	if (size != 0) {
1019 		if (vmem_add(vm, base, size, flags) != 0) {
1020 			vmem_destroy1(vm);
1021 			return NULL;
1022 		}
1023 	}
1024 
1025 #if defined(_KERNEL)
1026 	if (flags & VM_BOOTSTRAP) {
1027 		bt_refill(vm);
1028 	}
1029 
1030 	mutex_enter(&vmem_list_lock);
1031 	LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist);
1032 	mutex_exit(&vmem_list_lock);
1033 #endif /* defined(_KERNEL) */
1034 
1035 	return vm;
1036 }
1037 
1038 
1039 
1040 /*
1041  * vmem_create: create an arena.
1042  *
1043  * => must not be called from interrupt context.
1044  */
1045 
1046 vmem_t *
1047 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
1048     vmem_size_t quantum, vmem_import_t *importfn, vmem_release_t *releasefn,
1049     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
1050 {
1051 
1052 	KASSERT((flags & (VM_XIMPORT)) == 0);
1053 
1054 	return vmem_init(NULL, name, base, size, quantum,
1055 	    importfn, releasefn, source, qcache_max, flags, ipl);
1056 }
1057 
1058 /*
1059  * vmem_xcreate: create an arena takes alternative import func.
1060  *
1061  * => must not be called from interrupt context.
1062  */
1063 
1064 vmem_t *
1065 vmem_xcreate(const char *name, vmem_addr_t base, vmem_size_t size,
1066     vmem_size_t quantum, vmem_ximport_t *importfn, vmem_release_t *releasefn,
1067     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
1068 {
1069 
1070 	KASSERT((flags & (VM_XIMPORT)) == 0);
1071 
1072 	return vmem_init(NULL, name, base, size, quantum,
1073 	    __FPTRCAST(vmem_import_t *, importfn), releasefn, source,
1074 	    qcache_max, flags | VM_XIMPORT, ipl);
1075 }
1076 
1077 void
1078 vmem_destroy(vmem_t *vm)
1079 {
1080 
1081 #if defined(_KERNEL)
1082 	mutex_enter(&vmem_list_lock);
1083 	LIST_REMOVE(vm, vm_alllist);
1084 	mutex_exit(&vmem_list_lock);
1085 #endif /* defined(_KERNEL) */
1086 
1087 	vmem_destroy1(vm);
1088 }
1089 
1090 vmem_size_t
1091 vmem_roundup_size(vmem_t *vm, vmem_size_t size)
1092 {
1093 
1094 	return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
1095 }
1096 
1097 /*
1098  * vmem_alloc: allocate resource from the arena.
1099  */
1100 
1101 int
1102 vmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, vmem_addr_t *addrp)
1103 {
1104 	const vm_flag_t strat __diagused = flags & VM_FITMASK;
1105 	int error;
1106 
1107 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
1108 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
1109 
1110 	KASSERT(size > 0);
1111 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
1112 	if ((flags & VM_SLEEP) != 0) {
1113 		ASSERT_SLEEPABLE();
1114 	}
1115 
1116 #if defined(QCACHE)
1117 	if (size <= vm->vm_qcache_max) {
1118 		void *p;
1119 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1120 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1121 
1122 		p = pool_cache_get(qc->qc_cache, vmf_to_prf(flags));
1123 		if (addrp != NULL)
1124 			*addrp = (vmem_addr_t)p;
1125 		error = (p == NULL) ? ENOMEM : 0;
1126 		goto out;
1127 	}
1128 #endif /* defined(QCACHE) */
1129 
1130 	error = vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
1131 	    flags, addrp);
1132 #if defined(QCACHE)
1133  out:
1134 #endif /* defined(QCACHE) */
1135 	KASSERTMSG(error || addrp == NULL ||
1136 	    (*addrp & vm->vm_quantum_mask) == 0,
1137 	    "vmem %s mask=0x%jx addr=0x%jx",
1138 	    vm->vm_name, (uintmax_t)vm->vm_quantum_mask, (uintmax_t)*addrp);
1139 	KASSERT(error == 0 || (flags & VM_SLEEP) == 0);
1140 	return error;
1141 }
1142 
1143 int
1144 vmem_xalloc_addr(vmem_t *vm, const vmem_addr_t addr, const vmem_size_t size,
1145     vm_flag_t flags)
1146 {
1147 	vmem_addr_t result;
1148 	int error;
1149 
1150 	KASSERT((addr & vm->vm_quantum_mask) == 0);
1151 	KASSERT(size != 0);
1152 
1153 	flags = (flags & ~VM_INSTANTFIT) | VM_BESTFIT;
1154 
1155 	error = vmem_xalloc(vm, size, 0, 0, 0, addr, addr + size - 1,
1156 	    flags, &result);
1157 
1158 	KASSERT(error || result == addr);
1159 	KASSERT(error == 0 || (flags & VM_SLEEP) == 0);
1160 	return error;
1161 }
1162 
1163 int
1164 vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align,
1165     const vmem_size_t phase, const vmem_size_t nocross,
1166     const vmem_addr_t minaddr, const vmem_addr_t maxaddr, const vm_flag_t flags,
1167     vmem_addr_t *addrp)
1168 {
1169 	struct vmem_freelist *list;
1170 	struct vmem_freelist *first;
1171 	struct vmem_freelist *end;
1172 	bt_t *bt;
1173 	bt_t *btnew;
1174 	bt_t *btnew2;
1175 	const vmem_size_t size = vmem_roundup_size(vm, size0);
1176 	vm_flag_t strat = flags & VM_FITMASK;
1177 	vmem_addr_t start;
1178 	int rc;
1179 
1180 	KASSERT(size0 > 0);
1181 	KASSERT(size > 0);
1182 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
1183 	if ((flags & VM_SLEEP) != 0) {
1184 		ASSERT_SLEEPABLE();
1185 	}
1186 	KASSERT((align & vm->vm_quantum_mask) == 0);
1187 	KASSERT((align & (align - 1)) == 0);
1188 	KASSERT((phase & vm->vm_quantum_mask) == 0);
1189 	KASSERT((nocross & vm->vm_quantum_mask) == 0);
1190 	KASSERT((nocross & (nocross - 1)) == 0);
1191 	KASSERT(align == 0 || phase < align);
1192 	KASSERT(phase == 0 || phase < align);
1193 	KASSERT(nocross == 0 || nocross >= size);
1194 	KASSERT(minaddr <= maxaddr);
1195 	KASSERT(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
1196 
1197 	if (align == 0) {
1198 		align = vm->vm_quantum_mask + 1;
1199 	}
1200 
1201 	/*
1202 	 * allocate boundary tags before acquiring the vmem lock.
1203 	 */
1204 	VMEM_LOCK(vm);
1205 	btnew = bt_alloc(vm, flags);
1206 	if (btnew == NULL) {
1207 		VMEM_UNLOCK(vm);
1208 		return ENOMEM;
1209 	}
1210 	btnew2 = bt_alloc(vm, flags); /* XXX not necessary if no restrictions */
1211 	if (btnew2 == NULL) {
1212 		bt_free(vm, btnew);
1213 		VMEM_UNLOCK(vm);
1214 		return ENOMEM;
1215 	}
1216 
1217 	/*
1218 	 * choose a free block from which we allocate.
1219 	 */
1220 retry_strat:
1221 	first = bt_freehead_toalloc(vm, size, strat);
1222 	end = &vm->vm_freelist[VMEM_MAXORDER];
1223 retry:
1224 	bt = NULL;
1225 	vmem_check(vm);
1226 	if (strat == VM_INSTANTFIT) {
1227 		/*
1228 		 * just choose the first block which satisfies our restrictions.
1229 		 *
1230 		 * note that we don't need to check the size of the blocks
1231 		 * because any blocks found on these list should be larger than
1232 		 * the given size.
1233 		 */
1234 		for (list = first; list < end; list++) {
1235 			bt = LIST_FIRST(list);
1236 			if (bt != NULL) {
1237 				rc = vmem_fit(bt, size, align, phase,
1238 				    nocross, minaddr, maxaddr, &start);
1239 				if (rc == 0) {
1240 					goto gotit;
1241 				}
1242 				/*
1243 				 * don't bother to follow the bt_freelist link
1244 				 * here.  the list can be very long and we are
1245 				 * told to run fast.  blocks from the later free
1246 				 * lists are larger and have better chances to
1247 				 * satisfy our restrictions.
1248 				 */
1249 			}
1250 		}
1251 	} else { /* VM_BESTFIT */
1252 		/*
1253 		 * we assume that, for space efficiency, it's better to
1254 		 * allocate from a smaller block.  thus we will start searching
1255 		 * from the lower-order list than VM_INSTANTFIT.
1256 		 * however, don't bother to find the smallest block in a free
1257 		 * list because the list can be very long.  we can revisit it
1258 		 * if/when it turns out to be a problem.
1259 		 *
1260 		 * note that the 'first' list can contain blocks smaller than
1261 		 * the requested size.  thus we need to check bt_size.
1262 		 */
1263 		for (list = first; list < end; list++) {
1264 			LIST_FOREACH(bt, list, bt_freelist) {
1265 				if (bt->bt_size >= size) {
1266 					rc = vmem_fit(bt, size, align, phase,
1267 					    nocross, minaddr, maxaddr, &start);
1268 					if (rc == 0) {
1269 						goto gotit;
1270 					}
1271 				}
1272 			}
1273 		}
1274 	}
1275 #if 1
1276 	if (strat == VM_INSTANTFIT) {
1277 		strat = VM_BESTFIT;
1278 		goto retry_strat;
1279 	}
1280 #endif
1281 	if (align != vm->vm_quantum_mask + 1 || phase != 0 || nocross != 0) {
1282 
1283 		/*
1284 		 * XXX should try to import a region large enough to
1285 		 * satisfy restrictions?
1286 		 */
1287 
1288 		goto fail;
1289 	}
1290 	/* XXX eeek, minaddr & maxaddr not respected */
1291 	if (vmem_import(vm, size, flags) == 0) {
1292 		goto retry;
1293 	}
1294 	/* XXX */
1295 
1296 	if ((flags & VM_SLEEP) != 0) {
1297 		vmem_kick_pdaemon();
1298 		VMEM_CONDVAR_WAIT(vm);
1299 		goto retry;
1300 	}
1301 fail:
1302 	bt_free(vm, btnew);
1303 	bt_free(vm, btnew2);
1304 	VMEM_UNLOCK(vm);
1305 	return ENOMEM;
1306 
1307 gotit:
1308 	KASSERT(bt->bt_type == BT_TYPE_FREE);
1309 	KASSERT(bt->bt_size >= size);
1310 	bt_remfree(vm, bt);
1311 	vmem_check(vm);
1312 	if (bt->bt_start != start) {
1313 		btnew2->bt_type = BT_TYPE_FREE;
1314 		btnew2->bt_start = bt->bt_start;
1315 		btnew2->bt_size = start - bt->bt_start;
1316 		bt->bt_start = start;
1317 		bt->bt_size -= btnew2->bt_size;
1318 		bt_insfree(vm, btnew2);
1319 		bt_insseg(vm, btnew2, TAILQ_PREV(bt, vmem_seglist, bt_seglist));
1320 		btnew2 = NULL;
1321 		vmem_check(vm);
1322 	}
1323 	KASSERT(bt->bt_start == start);
1324 	if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
1325 		/* split */
1326 		btnew->bt_type = BT_TYPE_BUSY;
1327 		btnew->bt_start = bt->bt_start;
1328 		btnew->bt_size = size;
1329 		bt->bt_start = bt->bt_start + size;
1330 		bt->bt_size -= size;
1331 		bt_insfree(vm, bt);
1332 		bt_insseg(vm, btnew, TAILQ_PREV(bt, vmem_seglist, bt_seglist));
1333 		bt_insbusy(vm, btnew);
1334 		vmem_check(vm);
1335 	} else {
1336 		bt->bt_type = BT_TYPE_BUSY;
1337 		bt_insbusy(vm, bt);
1338 		vmem_check(vm);
1339 		bt_free(vm, btnew);
1340 		btnew = bt;
1341 	}
1342 	if (btnew2 != NULL) {
1343 		bt_free(vm, btnew2);
1344 	}
1345 	KASSERT(btnew->bt_size >= size);
1346 	btnew->bt_type = BT_TYPE_BUSY;
1347 	if (addrp != NULL)
1348 		*addrp = btnew->bt_start;
1349 	VMEM_UNLOCK(vm);
1350 	KASSERTMSG(addrp == NULL ||
1351 	    (*addrp & vm->vm_quantum_mask) == 0,
1352 	    "vmem %s mask=0x%jx addr=0x%jx",
1353 	    vm->vm_name, (uintmax_t)vm->vm_quantum_mask, (uintmax_t)*addrp);
1354 	return 0;
1355 }
1356 
1357 /*
1358  * vmem_free: free the resource to the arena.
1359  */
1360 
1361 void
1362 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1363 {
1364 
1365 	KASSERT(size > 0);
1366 	KASSERTMSG((addr & vm->vm_quantum_mask) == 0,
1367 	    "vmem %s mask=0x%jx addr=0x%jx",
1368 	    vm->vm_name, (uintmax_t)vm->vm_quantum_mask, (uintmax_t)addr);
1369 
1370 #if defined(QCACHE)
1371 	if (size <= vm->vm_qcache_max) {
1372 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1373 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1374 
1375 		pool_cache_put(qc->qc_cache, (void *)addr);
1376 		return;
1377 	}
1378 #endif /* defined(QCACHE) */
1379 
1380 	vmem_xfree(vm, addr, size);
1381 }
1382 
1383 void
1384 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1385 {
1386 	bt_t *bt;
1387 
1388 	KASSERT(size > 0);
1389 	KASSERTMSG((addr & vm->vm_quantum_mask) == 0,
1390 	    "vmem %s mask=0x%jx addr=0x%jx",
1391 	    vm->vm_name, (uintmax_t)vm->vm_quantum_mask, (uintmax_t)addr);
1392 
1393 	VMEM_LOCK(vm);
1394 
1395 	bt = bt_lookupbusy(vm, addr);
1396 	KASSERTMSG(bt != NULL, "vmem %s addr 0x%jx size 0x%jx",
1397 	    vm->vm_name, (uintmax_t)addr, (uintmax_t)size);
1398 	KASSERT(bt->bt_start == addr);
1399 	KASSERT(bt->bt_size == vmem_roundup_size(vm, size) ||
1400 	    bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
1401 
1402 	/* vmem_xfree_bt() drops the lock. */
1403 	vmem_xfree_bt(vm, bt);
1404 }
1405 
1406 void
1407 vmem_xfreeall(vmem_t *vm)
1408 {
1409 	bt_t *bt;
1410 
1411 #if defined(QCACHE)
1412 	/* This can't be used if the arena has a quantum cache. */
1413 	KASSERT(vm->vm_qcache_max == 0);
1414 #endif /* defined(QCACHE) */
1415 
1416 	for (;;) {
1417 		VMEM_LOCK(vm);
1418 		TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1419 			if (bt->bt_type == BT_TYPE_BUSY)
1420 				break;
1421 		}
1422 		if (bt != NULL) {
1423 			/* vmem_xfree_bt() drops the lock. */
1424 			vmem_xfree_bt(vm, bt);
1425 		} else {
1426 			VMEM_UNLOCK(vm);
1427 			return;
1428 		}
1429 	}
1430 }
1431 
1432 static void
1433 vmem_xfree_bt(vmem_t *vm, bt_t *bt)
1434 {
1435 	bt_t *t;
1436 
1437 	VMEM_ASSERT_LOCKED(vm);
1438 
1439 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
1440 	bt_rembusy(vm, bt);
1441 	bt->bt_type = BT_TYPE_FREE;
1442 
1443 	/* coalesce */
1444 	t = TAILQ_NEXT(bt, bt_seglist);
1445 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1446 		KASSERT(BT_END(bt) < t->bt_start);	/* YYY */
1447 		bt_remfree(vm, t);
1448 		bt_remseg(vm, t);
1449 		bt->bt_size += t->bt_size;
1450 		bt_free(vm, t);
1451 	}
1452 	t = TAILQ_PREV(bt, vmem_seglist, bt_seglist);
1453 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1454 		KASSERT(BT_END(t) < bt->bt_start);	/* YYY */
1455 		bt_remfree(vm, t);
1456 		bt_remseg(vm, t);
1457 		bt->bt_size += t->bt_size;
1458 		bt->bt_start = t->bt_start;
1459 		bt_free(vm, t);
1460 	}
1461 
1462 	t = TAILQ_PREV(bt, vmem_seglist, bt_seglist);
1463 	KASSERT(t != NULL);
1464 	KASSERT(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY);
1465 	if (vm->vm_releasefn != NULL && t->bt_type == BT_TYPE_SPAN &&
1466 	    t->bt_size == bt->bt_size) {
1467 		vmem_addr_t spanaddr;
1468 		vmem_size_t spansize;
1469 
1470 		KASSERT(t->bt_start == bt->bt_start);
1471 		spanaddr = bt->bt_start;
1472 		spansize = bt->bt_size;
1473 		bt_remseg(vm, bt);
1474 		bt_free(vm, bt);
1475 		bt_remseg(vm, t);
1476 		bt_free(vm, t);
1477 		vm->vm_size -= spansize;
1478 		VMEM_CONDVAR_BROADCAST(vm);
1479 		/* bt_freetrim() drops the lock. */
1480 		bt_freetrim(vm, BT_MAXFREE);
1481 		(*vm->vm_releasefn)(vm->vm_arg, spanaddr, spansize);
1482 	} else {
1483 		bt_insfree(vm, bt);
1484 		VMEM_CONDVAR_BROADCAST(vm);
1485 		/* bt_freetrim() drops the lock. */
1486 		bt_freetrim(vm, BT_MAXFREE);
1487 	}
1488 }
1489 
1490 /*
1491  * vmem_add:
1492  *
1493  * => caller must ensure appropriate spl,
1494  *    if the arena can be accessed from interrupt context.
1495  */
1496 
1497 int
1498 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags)
1499 {
1500 	int rv;
1501 
1502 	VMEM_LOCK(vm);
1503 	rv = vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN_STATIC);
1504 	VMEM_UNLOCK(vm);
1505 
1506 	return rv;
1507 }
1508 
1509 /*
1510  * vmem_size: information about arenas size
1511  *
1512  * => return free/allocated size in arena
1513  */
1514 vmem_size_t
1515 vmem_size(vmem_t *vm, int typemask)
1516 {
1517 
1518 	switch (typemask) {
1519 	case VMEM_ALLOC:
1520 		return vm->vm_inuse;
1521 	case VMEM_FREE:
1522 		return vm->vm_size - vm->vm_inuse;
1523 	case VMEM_FREE|VMEM_ALLOC:
1524 		return vm->vm_size;
1525 	default:
1526 		panic("vmem_size");
1527 	}
1528 }
1529 
1530 /* ---- rehash */
1531 
1532 #if defined(_KERNEL)
1533 static struct callout vmem_rehash_ch;
1534 static int vmem_rehash_interval;
1535 static struct workqueue *vmem_rehash_wq;
1536 static struct work vmem_rehash_wk;
1537 
1538 static void
1539 vmem_rehash_all(struct work *wk, void *dummy)
1540 {
1541 	vmem_t *vm;
1542 
1543 	KASSERT(wk == &vmem_rehash_wk);
1544 	mutex_enter(&vmem_list_lock);
1545 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1546 		size_t desired;
1547 		size_t current;
1548 
1549 		desired = atomic_load_relaxed(&vm->vm_maxbusytag);
1550 		current = atomic_load_relaxed(&vm->vm_hashsize);
1551 
1552 		if (desired > VMEM_HASHSIZE_MAX) {
1553 			desired = VMEM_HASHSIZE_MAX;
1554 		} else if (desired < VMEM_HASHSIZE_MIN) {
1555 			desired = VMEM_HASHSIZE_MIN;
1556 		}
1557 		if (desired > current * 2 || desired * 2 < current) {
1558 			vmem_rehash(vm, desired, VM_NOSLEEP);
1559 		}
1560 	}
1561 	mutex_exit(&vmem_list_lock);
1562 
1563 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1564 }
1565 
1566 static void
1567 vmem_rehash_all_kick(void *dummy)
1568 {
1569 
1570 	workqueue_enqueue(vmem_rehash_wq, &vmem_rehash_wk, NULL);
1571 }
1572 
1573 void
1574 vmem_rehash_start(void)
1575 {
1576 	int error;
1577 
1578 	error = workqueue_create(&vmem_rehash_wq, "vmem_rehash",
1579 	    vmem_rehash_all, NULL, PRI_VM, IPL_SOFTCLOCK, WQ_MPSAFE);
1580 	if (error) {
1581 		panic("%s: workqueue_create %d\n", __func__, error);
1582 	}
1583 	callout_init(&vmem_rehash_ch, CALLOUT_MPSAFE);
1584 	callout_setfunc(&vmem_rehash_ch, vmem_rehash_all_kick, NULL);
1585 
1586 	vmem_rehash_interval = hz * 10;
1587 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1588 }
1589 #endif /* defined(_KERNEL) */
1590 
1591 /* ---- debug */
1592 
1593 #if defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY)
1594 
1595 static void bt_dump(const bt_t *, void (*)(const char *, ...)
1596     __printflike(1, 2));
1597 
1598 static const char *
1599 bt_type_string(int type)
1600 {
1601 	static const char * const table[] = {
1602 		[BT_TYPE_BUSY] = "busy",
1603 		[BT_TYPE_FREE] = "free",
1604 		[BT_TYPE_SPAN] = "span",
1605 		[BT_TYPE_SPAN_STATIC] = "static span",
1606 	};
1607 
1608 	if (type >= __arraycount(table)) {
1609 		return "BOGUS";
1610 	}
1611 	return table[type];
1612 }
1613 
1614 static void
1615 bt_dump(const bt_t *bt, void (*pr)(const char *, ...))
1616 {
1617 
1618 	(*pr)("\t%p: %" PRIu64 ", %" PRIu64 ", %d(%s)\n",
1619 	    bt, (uint64_t)bt->bt_start, (uint64_t)bt->bt_size,
1620 	    bt->bt_type, bt_type_string(bt->bt_type));
1621 }
1622 
1623 static void
1624 vmem_dump(const vmem_t *vm , void (*pr)(const char *, ...) __printflike(1, 2))
1625 {
1626 	const bt_t *bt;
1627 	int i;
1628 
1629 	(*pr)("vmem %p '%s'\n", vm, vm->vm_name);
1630 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1631 		bt_dump(bt, pr);
1632 	}
1633 
1634 	for (i = 0; i < VMEM_MAXORDER; i++) {
1635 		const struct vmem_freelist *fl = &vm->vm_freelist[i];
1636 
1637 		if (LIST_EMPTY(fl)) {
1638 			continue;
1639 		}
1640 
1641 		(*pr)("freelist[%d]\n", i);
1642 		LIST_FOREACH(bt, fl, bt_freelist) {
1643 			bt_dump(bt, pr);
1644 		}
1645 	}
1646 }
1647 
1648 #endif /* defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY) */
1649 
1650 #if defined(DDB)
1651 static bt_t *
1652 vmem_whatis_lookup(vmem_t *vm, uintptr_t addr)
1653 {
1654 	bt_t *bt;
1655 
1656 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1657 		if (BT_ISSPAN_P(bt)) {
1658 			continue;
1659 		}
1660 		if (bt->bt_start <= addr && addr <= BT_END(bt)) {
1661 			return bt;
1662 		}
1663 	}
1664 
1665 	return NULL;
1666 }
1667 
1668 void
1669 vmem_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1670 {
1671 	vmem_t *vm;
1672 
1673 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1674 		bt_t *bt;
1675 
1676 		bt = vmem_whatis_lookup(vm, addr);
1677 		if (bt == NULL) {
1678 			continue;
1679 		}
1680 		(*pr)("%p is %p+%zu in VMEM '%s' (%s)\n",
1681 		    (void *)addr, (void *)bt->bt_start,
1682 		    (size_t)(addr - bt->bt_start), vm->vm_name,
1683 		    (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free");
1684 	}
1685 }
1686 
1687 void
1688 vmem_printall(const char *modif, void (*pr)(const char *, ...))
1689 {
1690 	const vmem_t *vm;
1691 
1692 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1693 		vmem_dump(vm, pr);
1694 	}
1695 }
1696 
1697 void
1698 vmem_print(uintptr_t addr, const char *modif, void (*pr)(const char *, ...))
1699 {
1700 	const vmem_t *vm = (const void *)addr;
1701 
1702 	vmem_dump(vm, pr);
1703 }
1704 #endif /* defined(DDB) */
1705 
1706 #if defined(_KERNEL)
1707 #define vmem_printf printf
1708 #else
1709 #include <stdio.h>
1710 #include <stdarg.h>
1711 
1712 static void
1713 vmem_printf(const char *fmt, ...)
1714 {
1715 	va_list ap;
1716 	va_start(ap, fmt);
1717 	vprintf(fmt, ap);
1718 	va_end(ap);
1719 }
1720 #endif
1721 
1722 #if defined(VMEM_SANITY)
1723 
1724 static bool
1725 vmem_check_sanity(vmem_t *vm)
1726 {
1727 	const bt_t *bt, *bt2;
1728 
1729 	KASSERT(vm != NULL);
1730 
1731 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1732 		if (bt->bt_start > BT_END(bt)) {
1733 			printf("corrupted tag\n");
1734 			bt_dump(bt, vmem_printf);
1735 			return false;
1736 		}
1737 	}
1738 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1739 		TAILQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) {
1740 			if (bt == bt2) {
1741 				continue;
1742 			}
1743 			if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) {
1744 				continue;
1745 			}
1746 			if (bt->bt_start <= BT_END(bt2) &&
1747 			    bt2->bt_start <= BT_END(bt)) {
1748 				printf("overwrapped tags\n");
1749 				bt_dump(bt, vmem_printf);
1750 				bt_dump(bt2, vmem_printf);
1751 				return false;
1752 			}
1753 		}
1754 	}
1755 
1756 	return true;
1757 }
1758 
1759 static void
1760 vmem_check(vmem_t *vm)
1761 {
1762 
1763 	if (!vmem_check_sanity(vm)) {
1764 		panic("insanity vmem %p", vm);
1765 	}
1766 }
1767 
1768 #endif /* defined(VMEM_SANITY) */
1769 
1770 #if defined(UNITTEST)
1771 int
1772 main(void)
1773 {
1774 	int rc;
1775 	vmem_t *vm;
1776 	vmem_addr_t p;
1777 	struct reg {
1778 		vmem_addr_t p;
1779 		vmem_size_t sz;
1780 		bool x;
1781 	} *reg = NULL;
1782 	int nreg = 0;
1783 	int nalloc = 0;
1784 	int nfree = 0;
1785 	vmem_size_t total = 0;
1786 #if 1
1787 	vm_flag_t strat = VM_INSTANTFIT;
1788 #else
1789 	vm_flag_t strat = VM_BESTFIT;
1790 #endif
1791 
1792 	vm = vmem_create("test", 0, 0, 1, NULL, NULL, NULL, 0, VM_SLEEP,
1793 #ifdef _KERNEL
1794 	    IPL_NONE
1795 #else
1796 	    0
1797 #endif
1798 	    );
1799 	if (vm == NULL) {
1800 		printf("vmem_create\n");
1801 		exit(EXIT_FAILURE);
1802 	}
1803 	vmem_dump(vm, vmem_printf);
1804 
1805 	rc = vmem_add(vm, 0, 50, VM_SLEEP);
1806 	assert(rc == 0);
1807 	rc = vmem_add(vm, 100, 200, VM_SLEEP);
1808 	assert(rc == 0);
1809 	rc = vmem_add(vm, 2000, 1, VM_SLEEP);
1810 	assert(rc == 0);
1811 	rc = vmem_add(vm, 40000, 65536, VM_SLEEP);
1812 	assert(rc == 0);
1813 	rc = vmem_add(vm, 10000, 10000, VM_SLEEP);
1814 	assert(rc == 0);
1815 	rc = vmem_add(vm, 500, 1000, VM_SLEEP);
1816 	assert(rc == 0);
1817 	rc = vmem_add(vm, 0xffffff00, 0x100, VM_SLEEP);
1818 	assert(rc == 0);
1819 	rc = vmem_xalloc(vm, 0x101, 0, 0, 0,
1820 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1821 	assert(rc != 0);
1822 	rc = vmem_xalloc(vm, 50, 0, 0, 0, 0, 49, strat|VM_SLEEP, &p);
1823 	assert(rc == 0 && p == 0);
1824 	vmem_xfree(vm, p, 50);
1825 	rc = vmem_xalloc(vm, 25, 0, 0, 0, 0, 24, strat|VM_SLEEP, &p);
1826 	assert(rc == 0 && p == 0);
1827 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1828 	    0xffffff01, 0xffffffff, strat|VM_SLEEP, &p);
1829 	assert(rc != 0);
1830 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1831 	    0xffffff00, 0xfffffffe, strat|VM_SLEEP, &p);
1832 	assert(rc != 0);
1833 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1834 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1835 	assert(rc == 0);
1836 	vmem_dump(vm, vmem_printf);
1837 	for (;;) {
1838 		struct reg *r;
1839 		int t = rand() % 100;
1840 
1841 		if (t > 45) {
1842 			/* alloc */
1843 			vmem_size_t sz = rand() % 500 + 1;
1844 			bool x;
1845 			vmem_size_t align, phase, nocross;
1846 			vmem_addr_t minaddr, maxaddr;
1847 
1848 			if (t > 70) {
1849 				x = true;
1850 				/* XXX */
1851 				align = 1 << (rand() % 15);
1852 				phase = rand() % 65536;
1853 				nocross = 1 << (rand() % 15);
1854 				if (align <= phase) {
1855 					phase = 0;
1856 				}
1857 				if (VMEM_CROSS_P(phase, phase + sz - 1,
1858 				    nocross)) {
1859 					nocross = 0;
1860 				}
1861 				do {
1862 					minaddr = rand() % 50000;
1863 					maxaddr = rand() % 70000;
1864 				} while (minaddr > maxaddr);
1865 				printf("=== xalloc %" PRIu64
1866 				    " align=%" PRIu64 ", phase=%" PRIu64
1867 				    ", nocross=%" PRIu64 ", min=%" PRIu64
1868 				    ", max=%" PRIu64 "\n",
1869 				    (uint64_t)sz,
1870 				    (uint64_t)align,
1871 				    (uint64_t)phase,
1872 				    (uint64_t)nocross,
1873 				    (uint64_t)minaddr,
1874 				    (uint64_t)maxaddr);
1875 				rc = vmem_xalloc(vm, sz, align, phase, nocross,
1876 				    minaddr, maxaddr, strat|VM_SLEEP, &p);
1877 			} else {
1878 				x = false;
1879 				printf("=== alloc %" PRIu64 "\n", (uint64_t)sz);
1880 				rc = vmem_alloc(vm, sz, strat|VM_SLEEP, &p);
1881 			}
1882 			printf("-> %" PRIu64 "\n", (uint64_t)p);
1883 			vmem_dump(vm, vmem_printf);
1884 			if (rc != 0) {
1885 				if (x) {
1886 					continue;
1887 				}
1888 				break;
1889 			}
1890 			nreg++;
1891 			reg = realloc(reg, sizeof(*reg) * nreg);
1892 			r = &reg[nreg - 1];
1893 			r->p = p;
1894 			r->sz = sz;
1895 			r->x = x;
1896 			total += sz;
1897 			nalloc++;
1898 		} else if (nreg != 0) {
1899 			/* free */
1900 			r = &reg[rand() % nreg];
1901 			printf("=== free %" PRIu64 ", %" PRIu64 "\n",
1902 			    (uint64_t)r->p, (uint64_t)r->sz);
1903 			if (r->x) {
1904 				vmem_xfree(vm, r->p, r->sz);
1905 			} else {
1906 				vmem_free(vm, r->p, r->sz);
1907 			}
1908 			total -= r->sz;
1909 			vmem_dump(vm, vmem_printf);
1910 			*r = reg[nreg - 1];
1911 			nreg--;
1912 			nfree++;
1913 		}
1914 		printf("total=%" PRIu64 "\n", (uint64_t)total);
1915 	}
1916 	fprintf(stderr, "total=%" PRIu64 ", nalloc=%d, nfree=%d\n",
1917 	    (uint64_t)total, nalloc, nfree);
1918 	exit(EXIT_SUCCESS);
1919 }
1920 #endif /* defined(UNITTEST) */
1921