xref: /netbsd-src/sys/kern/subr_vmem.c (revision 466a16a118933bd295a8a104f095714fadf9cf68)
1 /*	$NetBSD: subr_vmem.c,v 1.52 2008/12/15 10:26:10 ad Exp $	*/
2 
3 /*-
4  * Copyright (c)2006 YAMAMOTO Takashi,
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * reference:
31  * -	Magazines and Vmem: Extending the Slab Allocator
32  *	to Many CPUs and Arbitrary Resources
33  *	http://www.usenix.org/event/usenix01/bonwick.html
34  *
35  * todo:
36  * -	decide how to import segments for vmem_xalloc.
37  * -	don't rely on malloc(9).
38  */
39 
40 #include <sys/cdefs.h>
41 __KERNEL_RCSID(0, "$NetBSD: subr_vmem.c,v 1.52 2008/12/15 10:26:10 ad 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 
52 #if defined(_KERNEL)
53 #include <sys/systm.h>
54 #include <sys/kernel.h>	/* hz */
55 #include <sys/callout.h>
56 #include <sys/malloc.h>
57 #include <sys/once.h>
58 #include <sys/pool.h>
59 #include <sys/vmem.h>
60 #include <sys/workqueue.h>
61 #else /* defined(_KERNEL) */
62 #include "../sys/vmem.h"
63 #endif /* defined(_KERNEL) */
64 
65 #if defined(_KERNEL)
66 #define	LOCK_DECL(name)		\
67     kmutex_t name; char lockpad[COHERENCY_UNIT - sizeof(kmutex_t)]
68 #else /* defined(_KERNEL) */
69 #include <errno.h>
70 #include <assert.h>
71 #include <stdlib.h>
72 
73 #define	KASSERT(a)		assert(a)
74 #define	LOCK_DECL(name)		/* nothing */
75 #define	mutex_init(a, b, c)	/* nothing */
76 #define	mutex_destroy(a)	/* nothing */
77 #define	mutex_enter(a)		/* nothing */
78 #define	mutex_exit(a)		/* nothing */
79 #define	mutex_owned(a)		/* nothing */
80 #define	ASSERT_SLEEPABLE()	 /* nothing */
81 #define	IPL_VM			0
82 #endif /* defined(_KERNEL) */
83 
84 struct vmem;
85 struct vmem_btag;
86 
87 #if defined(VMEM_DEBUG)
88 void vmem_dump(const vmem_t *);
89 #endif /* defined(VMEM_DEBUG) */
90 
91 #define	VMEM_MAXORDER		(sizeof(vmem_size_t) * CHAR_BIT)
92 
93 #define	VMEM_HASHSIZE_MIN	1	/* XXX */
94 #define	VMEM_HASHSIZE_MAX	8192	/* XXX */
95 #define	VMEM_HASHSIZE_INIT	VMEM_HASHSIZE_MIN
96 
97 #define	VM_FITMASK	(VM_BESTFIT | VM_INSTANTFIT)
98 
99 CIRCLEQ_HEAD(vmem_seglist, vmem_btag);
100 LIST_HEAD(vmem_freelist, vmem_btag);
101 LIST_HEAD(vmem_hashlist, vmem_btag);
102 
103 #if defined(QCACHE)
104 #define	VMEM_QCACHE_IDX_MAX	32
105 
106 #define	QC_NAME_MAX	16
107 
108 struct qcache {
109 	pool_cache_t qc_cache;
110 	vmem_t *qc_vmem;
111 	char qc_name[QC_NAME_MAX];
112 };
113 typedef struct qcache qcache_t;
114 #define	QC_POOL_TO_QCACHE(pool)	((qcache_t *)(pool->pr_qcache))
115 #endif /* defined(QCACHE) */
116 
117 /* vmem arena */
118 struct vmem {
119 	LOCK_DECL(vm_lock);
120 	vmem_addr_t (*vm_allocfn)(vmem_t *, vmem_size_t, vmem_size_t *,
121 	    vm_flag_t);
122 	void (*vm_freefn)(vmem_t *, vmem_addr_t, vmem_size_t);
123 	vmem_t *vm_source;
124 	struct vmem_seglist vm_seglist;
125 	struct vmem_freelist vm_freelist[VMEM_MAXORDER];
126 	size_t vm_hashsize;
127 	size_t vm_nbusytag;
128 	struct vmem_hashlist *vm_hashlist;
129 	size_t vm_quantum_mask;
130 	int vm_quantum_shift;
131 	const char *vm_name;
132 	LIST_ENTRY(vmem) vm_alllist;
133 
134 #if defined(QCACHE)
135 	/* quantum cache */
136 	size_t vm_qcache_max;
137 	struct pool_allocator vm_qcache_allocator;
138 	qcache_t vm_qcache_store[VMEM_QCACHE_IDX_MAX];
139 	qcache_t *vm_qcache[VMEM_QCACHE_IDX_MAX];
140 #endif /* defined(QCACHE) */
141 };
142 
143 #define	VMEM_LOCK(vm)		mutex_enter(&vm->vm_lock)
144 #define	VMEM_TRYLOCK(vm)	mutex_tryenter(&vm->vm_lock)
145 #define	VMEM_UNLOCK(vm)		mutex_exit(&vm->vm_lock)
146 #define	VMEM_LOCK_INIT(vm, ipl)	mutex_init(&vm->vm_lock, MUTEX_DEFAULT, ipl)
147 #define	VMEM_LOCK_DESTROY(vm)	mutex_destroy(&vm->vm_lock)
148 #define	VMEM_ASSERT_LOCKED(vm)	KASSERT(mutex_owned(&vm->vm_lock))
149 
150 /* boundary tag */
151 struct vmem_btag {
152 	CIRCLEQ_ENTRY(vmem_btag) bt_seglist;
153 	union {
154 		LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */
155 		LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */
156 	} bt_u;
157 #define	bt_hashlist	bt_u.u_hashlist
158 #define	bt_freelist	bt_u.u_freelist
159 	vmem_addr_t bt_start;
160 	vmem_size_t bt_size;
161 	int bt_type;
162 };
163 
164 #define	BT_TYPE_SPAN		1
165 #define	BT_TYPE_SPAN_STATIC	2
166 #define	BT_TYPE_FREE		3
167 #define	BT_TYPE_BUSY		4
168 #define	BT_ISSPAN_P(bt)	((bt)->bt_type <= BT_TYPE_SPAN_STATIC)
169 
170 #define	BT_END(bt)	((bt)->bt_start + (bt)->bt_size)
171 
172 typedef struct vmem_btag bt_t;
173 
174 /* ---- misc */
175 
176 #define	VMEM_ALIGNUP(addr, align) \
177 	(-(-(addr) & -(align)))
178 #define	VMEM_CROSS_P(addr1, addr2, boundary) \
179 	((((addr1) ^ (addr2)) & -(boundary)) != 0)
180 
181 #define	ORDER2SIZE(order)	((vmem_size_t)1 << (order))
182 
183 static int
184 calc_order(vmem_size_t size)
185 {
186 	vmem_size_t target;
187 	int i;
188 
189 	KASSERT(size != 0);
190 
191 	i = 0;
192 	target = size >> 1;
193 	while (ORDER2SIZE(i) <= target) {
194 		i++;
195 	}
196 
197 	KASSERT(ORDER2SIZE(i) <= size);
198 	KASSERT(size < ORDER2SIZE(i + 1) || ORDER2SIZE(i + 1) < ORDER2SIZE(i));
199 
200 	return i;
201 }
202 
203 #if defined(_KERNEL)
204 static MALLOC_DEFINE(M_VMEM, "vmem", "vmem");
205 #endif /* defined(_KERNEL) */
206 
207 static void *
208 xmalloc(size_t sz, vm_flag_t flags)
209 {
210 
211 #if defined(_KERNEL)
212 	return malloc(sz, M_VMEM,
213 	    M_CANFAIL | ((flags & VM_SLEEP) ? M_WAITOK : M_NOWAIT));
214 #else /* defined(_KERNEL) */
215 	return malloc(sz);
216 #endif /* defined(_KERNEL) */
217 }
218 
219 static void
220 xfree(void *p)
221 {
222 
223 #if defined(_KERNEL)
224 	return free(p, M_VMEM);
225 #else /* defined(_KERNEL) */
226 	return free(p);
227 #endif /* defined(_KERNEL) */
228 }
229 
230 /* ---- boundary tag */
231 
232 #if defined(_KERNEL)
233 static struct pool_cache bt_cache;
234 #endif /* defined(_KERNEL) */
235 
236 static bt_t *
237 bt_alloc(vmem_t *vm, vm_flag_t flags)
238 {
239 	bt_t *bt;
240 
241 #if defined(_KERNEL)
242 	bt = pool_cache_get(&bt_cache,
243 	    (flags & VM_SLEEP) != 0 ? PR_WAITOK : PR_NOWAIT);
244 #else /* defined(_KERNEL) */
245 	bt = malloc(sizeof *bt);
246 #endif /* defined(_KERNEL) */
247 
248 	return bt;
249 }
250 
251 static void
252 bt_free(vmem_t *vm, bt_t *bt)
253 {
254 
255 #if defined(_KERNEL)
256 	pool_cache_put(&bt_cache, bt);
257 #else /* defined(_KERNEL) */
258 	free(bt);
259 #endif /* defined(_KERNEL) */
260 }
261 
262 /*
263  * freelist[0] ... [1, 1]
264  * freelist[1] ... [2, 3]
265  * freelist[2] ... [4, 7]
266  * freelist[3] ... [8, 15]
267  *  :
268  * freelist[n] ... [(1 << n), (1 << (n + 1)) - 1]
269  *  :
270  */
271 
272 static struct vmem_freelist *
273 bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
274 {
275 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
276 	int idx;
277 
278 	KASSERT((size & vm->vm_quantum_mask) == 0);
279 	KASSERT(size != 0);
280 
281 	idx = calc_order(qsize);
282 	KASSERT(idx >= 0);
283 	KASSERT(idx < VMEM_MAXORDER);
284 
285 	return &vm->vm_freelist[idx];
286 }
287 
288 static struct vmem_freelist *
289 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, vm_flag_t strat)
290 {
291 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
292 	int idx;
293 
294 	KASSERT((size & vm->vm_quantum_mask) == 0);
295 	KASSERT(size != 0);
296 
297 	idx = calc_order(qsize);
298 	if (strat == VM_INSTANTFIT && ORDER2SIZE(idx) != qsize) {
299 		idx++;
300 		/* check too large request? */
301 	}
302 	KASSERT(idx >= 0);
303 	KASSERT(idx < VMEM_MAXORDER);
304 
305 	return &vm->vm_freelist[idx];
306 }
307 
308 /* ---- boundary tag hash */
309 
310 static struct vmem_hashlist *
311 bt_hashhead(vmem_t *vm, vmem_addr_t addr)
312 {
313 	struct vmem_hashlist *list;
314 	unsigned int hash;
315 
316 	hash = hash32_buf(&addr, sizeof(addr), HASH32_BUF_INIT);
317 	list = &vm->vm_hashlist[hash % vm->vm_hashsize];
318 
319 	return list;
320 }
321 
322 static bt_t *
323 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
324 {
325 	struct vmem_hashlist *list;
326 	bt_t *bt;
327 
328 	list = bt_hashhead(vm, addr);
329 	LIST_FOREACH(bt, list, bt_hashlist) {
330 		if (bt->bt_start == addr) {
331 			break;
332 		}
333 	}
334 
335 	return bt;
336 }
337 
338 static void
339 bt_rembusy(vmem_t *vm, bt_t *bt)
340 {
341 
342 	KASSERT(vm->vm_nbusytag > 0);
343 	vm->vm_nbusytag--;
344 	LIST_REMOVE(bt, bt_hashlist);
345 }
346 
347 static void
348 bt_insbusy(vmem_t *vm, bt_t *bt)
349 {
350 	struct vmem_hashlist *list;
351 
352 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
353 
354 	list = bt_hashhead(vm, bt->bt_start);
355 	LIST_INSERT_HEAD(list, bt, bt_hashlist);
356 	vm->vm_nbusytag++;
357 }
358 
359 /* ---- boundary tag list */
360 
361 static void
362 bt_remseg(vmem_t *vm, bt_t *bt)
363 {
364 
365 	CIRCLEQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
366 }
367 
368 static void
369 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
370 {
371 
372 	CIRCLEQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
373 }
374 
375 static void
376 bt_insseg_tail(vmem_t *vm, bt_t *bt)
377 {
378 
379 	CIRCLEQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
380 }
381 
382 static void
383 bt_remfree(vmem_t *vm, bt_t *bt)
384 {
385 
386 	KASSERT(bt->bt_type == BT_TYPE_FREE);
387 
388 	LIST_REMOVE(bt, bt_freelist);
389 }
390 
391 static void
392 bt_insfree(vmem_t *vm, bt_t *bt)
393 {
394 	struct vmem_freelist *list;
395 
396 	list = bt_freehead_tofree(vm, bt->bt_size);
397 	LIST_INSERT_HEAD(list, bt, bt_freelist);
398 }
399 
400 /* ---- vmem internal functions */
401 
402 #if defined(_KERNEL)
403 static kmutex_t vmem_list_lock;
404 static LIST_HEAD(, vmem) vmem_list = LIST_HEAD_INITIALIZER(vmem_list);
405 #endif /* defined(_KERNEL) */
406 
407 #if defined(QCACHE)
408 static inline vm_flag_t
409 prf_to_vmf(int prflags)
410 {
411 	vm_flag_t vmflags;
412 
413 	KASSERT((prflags & ~(PR_LIMITFAIL | PR_WAITOK | PR_NOWAIT)) == 0);
414 	if ((prflags & PR_WAITOK) != 0) {
415 		vmflags = VM_SLEEP;
416 	} else {
417 		vmflags = VM_NOSLEEP;
418 	}
419 	return vmflags;
420 }
421 
422 static inline int
423 vmf_to_prf(vm_flag_t vmflags)
424 {
425 	int prflags;
426 
427 	if ((vmflags & VM_SLEEP) != 0) {
428 		prflags = PR_WAITOK;
429 	} else {
430 		prflags = PR_NOWAIT;
431 	}
432 	return prflags;
433 }
434 
435 static size_t
436 qc_poolpage_size(size_t qcache_max)
437 {
438 	int i;
439 
440 	for (i = 0; ORDER2SIZE(i) <= qcache_max * 3; i++) {
441 		/* nothing */
442 	}
443 	return ORDER2SIZE(i);
444 }
445 
446 static void *
447 qc_poolpage_alloc(struct pool *pool, int prflags)
448 {
449 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
450 	vmem_t *vm = qc->qc_vmem;
451 
452 	return (void *)vmem_alloc(vm, pool->pr_alloc->pa_pagesz,
453 	    prf_to_vmf(prflags) | VM_INSTANTFIT);
454 }
455 
456 static void
457 qc_poolpage_free(struct pool *pool, void *addr)
458 {
459 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
460 	vmem_t *vm = qc->qc_vmem;
461 
462 	vmem_free(vm, (vmem_addr_t)addr, pool->pr_alloc->pa_pagesz);
463 }
464 
465 static void
466 qc_init(vmem_t *vm, size_t qcache_max, int ipl)
467 {
468 	qcache_t *prevqc;
469 	struct pool_allocator *pa;
470 	int qcache_idx_max;
471 	int i;
472 
473 	KASSERT((qcache_max & vm->vm_quantum_mask) == 0);
474 	if (qcache_max > (VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift)) {
475 		qcache_max = VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift;
476 	}
477 	vm->vm_qcache_max = qcache_max;
478 	pa = &vm->vm_qcache_allocator;
479 	memset(pa, 0, sizeof(*pa));
480 	pa->pa_alloc = qc_poolpage_alloc;
481 	pa->pa_free = qc_poolpage_free;
482 	pa->pa_pagesz = qc_poolpage_size(qcache_max);
483 
484 	qcache_idx_max = qcache_max >> vm->vm_quantum_shift;
485 	prevqc = NULL;
486 	for (i = qcache_idx_max; i > 0; i--) {
487 		qcache_t *qc = &vm->vm_qcache_store[i - 1];
488 		size_t size = i << vm->vm_quantum_shift;
489 
490 		qc->qc_vmem = vm;
491 		snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu",
492 		    vm->vm_name, size);
493 		qc->qc_cache = pool_cache_init(size,
494 		    ORDER2SIZE(vm->vm_quantum_shift), 0,
495 		    PR_NOALIGN | PR_NOTOUCH /* XXX */,
496 		    qc->qc_name, pa, ipl, NULL, NULL, NULL);
497 		KASSERT(qc->qc_cache != NULL);	/* XXX */
498 		if (prevqc != NULL &&
499 		    qc->qc_cache->pc_pool.pr_itemsperpage ==
500 		    prevqc->qc_cache->pc_pool.pr_itemsperpage) {
501 			pool_cache_destroy(qc->qc_cache);
502 			vm->vm_qcache[i - 1] = prevqc;
503 			continue;
504 		}
505 		qc->qc_cache->pc_pool.pr_qcache = qc;
506 		vm->vm_qcache[i - 1] = qc;
507 		prevqc = qc;
508 	}
509 }
510 
511 static void
512 qc_destroy(vmem_t *vm)
513 {
514 	const qcache_t *prevqc;
515 	int i;
516 	int qcache_idx_max;
517 
518 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
519 	prevqc = NULL;
520 	for (i = 0; i < qcache_idx_max; i++) {
521 		qcache_t *qc = vm->vm_qcache[i];
522 
523 		if (prevqc == qc) {
524 			continue;
525 		}
526 		pool_cache_destroy(qc->qc_cache);
527 		prevqc = qc;
528 	}
529 }
530 
531 static bool
532 qc_reap(vmem_t *vm)
533 {
534 	const qcache_t *prevqc;
535 	int i;
536 	int qcache_idx_max;
537 	bool didsomething = false;
538 
539 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
540 	prevqc = NULL;
541 	for (i = 0; i < qcache_idx_max; i++) {
542 		qcache_t *qc = vm->vm_qcache[i];
543 
544 		if (prevqc == qc) {
545 			continue;
546 		}
547 		if (pool_cache_reclaim(qc->qc_cache) != 0) {
548 			didsomething = true;
549 		}
550 		prevqc = qc;
551 	}
552 
553 	return didsomething;
554 }
555 #endif /* defined(QCACHE) */
556 
557 #if defined(_KERNEL)
558 static int
559 vmem_init(void)
560 {
561 
562 	mutex_init(&vmem_list_lock, MUTEX_DEFAULT, IPL_NONE);
563 	pool_cache_bootstrap(&bt_cache, sizeof(bt_t), 0, 0, 0, "vmembt",
564 	    NULL, IPL_VM, NULL, NULL, NULL);
565 	return 0;
566 }
567 #endif /* defined(_KERNEL) */
568 
569 static vmem_addr_t
570 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags,
571     int spanbttype)
572 {
573 	bt_t *btspan;
574 	bt_t *btfree;
575 
576 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
577 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
578 	KASSERT(spanbttype == BT_TYPE_SPAN || spanbttype == BT_TYPE_SPAN_STATIC);
579 
580 	btspan = bt_alloc(vm, flags);
581 	if (btspan == NULL) {
582 		return VMEM_ADDR_NULL;
583 	}
584 	btfree = bt_alloc(vm, flags);
585 	if (btfree == NULL) {
586 		bt_free(vm, btspan);
587 		return VMEM_ADDR_NULL;
588 	}
589 
590 	btspan->bt_type = spanbttype;
591 	btspan->bt_start = addr;
592 	btspan->bt_size = size;
593 
594 	btfree->bt_type = BT_TYPE_FREE;
595 	btfree->bt_start = addr;
596 	btfree->bt_size = size;
597 
598 	VMEM_LOCK(vm);
599 	bt_insseg_tail(vm, btspan);
600 	bt_insseg(vm, btfree, btspan);
601 	bt_insfree(vm, btfree);
602 	VMEM_UNLOCK(vm);
603 
604 	return addr;
605 }
606 
607 static void
608 vmem_destroy1(vmem_t *vm)
609 {
610 
611 #if defined(QCACHE)
612 	qc_destroy(vm);
613 #endif /* defined(QCACHE) */
614 	if (vm->vm_hashlist != NULL) {
615 		int i;
616 
617 		for (i = 0; i < vm->vm_hashsize; i++) {
618 			bt_t *bt;
619 
620 			while ((bt = LIST_FIRST(&vm->vm_hashlist[i])) != NULL) {
621 				KASSERT(bt->bt_type == BT_TYPE_SPAN_STATIC);
622 				bt_free(vm, bt);
623 			}
624 		}
625 		xfree(vm->vm_hashlist);
626 	}
627 	VMEM_LOCK_DESTROY(vm);
628 	xfree(vm);
629 }
630 
631 static int
632 vmem_import(vmem_t *vm, vmem_size_t size, vm_flag_t flags)
633 {
634 	vmem_addr_t addr;
635 
636 	if (vm->vm_allocfn == NULL) {
637 		return EINVAL;
638 	}
639 
640 	addr = (*vm->vm_allocfn)(vm->vm_source, size, &size, flags);
641 	if (addr == VMEM_ADDR_NULL) {
642 		return ENOMEM;
643 	}
644 
645 	if (vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN) == VMEM_ADDR_NULL) {
646 		(*vm->vm_freefn)(vm->vm_source, addr, size);
647 		return ENOMEM;
648 	}
649 
650 	return 0;
651 }
652 
653 static int
654 vmem_rehash(vmem_t *vm, size_t newhashsize, vm_flag_t flags)
655 {
656 	bt_t *bt;
657 	int i;
658 	struct vmem_hashlist *newhashlist;
659 	struct vmem_hashlist *oldhashlist;
660 	size_t oldhashsize;
661 
662 	KASSERT(newhashsize > 0);
663 
664 	newhashlist =
665 	    xmalloc(sizeof(struct vmem_hashlist *) * newhashsize, flags);
666 	if (newhashlist == NULL) {
667 		return ENOMEM;
668 	}
669 	for (i = 0; i < newhashsize; i++) {
670 		LIST_INIT(&newhashlist[i]);
671 	}
672 
673 	if (!VMEM_TRYLOCK(vm)) {
674 		xfree(newhashlist);
675 		return EBUSY;
676 	}
677 	oldhashlist = vm->vm_hashlist;
678 	oldhashsize = vm->vm_hashsize;
679 	vm->vm_hashlist = newhashlist;
680 	vm->vm_hashsize = newhashsize;
681 	if (oldhashlist == NULL) {
682 		VMEM_UNLOCK(vm);
683 		return 0;
684 	}
685 	for (i = 0; i < oldhashsize; i++) {
686 		while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
687 			bt_rembusy(vm, bt); /* XXX */
688 			bt_insbusy(vm, bt);
689 		}
690 	}
691 	VMEM_UNLOCK(vm);
692 
693 	xfree(oldhashlist);
694 
695 	return 0;
696 }
697 
698 /*
699  * vmem_fit: check if a bt can satisfy the given restrictions.
700  */
701 
702 static vmem_addr_t
703 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align, vmem_size_t phase,
704     vmem_size_t nocross, vmem_addr_t minaddr, vmem_addr_t maxaddr)
705 {
706 	vmem_addr_t start;
707 	vmem_addr_t end;
708 
709 	KASSERT(bt->bt_size >= size);
710 
711 	/*
712 	 * XXX assumption: vmem_addr_t and vmem_size_t are
713 	 * unsigned integer of the same size.
714 	 */
715 
716 	start = bt->bt_start;
717 	if (start < minaddr) {
718 		start = minaddr;
719 	}
720 	end = BT_END(bt);
721 	if (end > maxaddr - 1) {
722 		end = maxaddr - 1;
723 	}
724 	if (start >= end) {
725 		return VMEM_ADDR_NULL;
726 	}
727 
728 	start = VMEM_ALIGNUP(start - phase, align) + phase;
729 	if (start < bt->bt_start) {
730 		start += align;
731 	}
732 	if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
733 		KASSERT(align < nocross);
734 		start = VMEM_ALIGNUP(start - phase, nocross) + phase;
735 	}
736 	if (start < end && end - start >= size) {
737 		KASSERT((start & (align - 1)) == phase);
738 		KASSERT(!VMEM_CROSS_P(start, start + size - 1, nocross));
739 		KASSERT(minaddr <= start);
740 		KASSERT(maxaddr == 0 || start + size <= maxaddr);
741 		KASSERT(bt->bt_start <= start);
742 		KASSERT(start + size <= BT_END(bt));
743 		return start;
744 	}
745 	return VMEM_ADDR_NULL;
746 }
747 
748 #if !defined(VMEM_DEBUG)
749 #define vmem_check_sanity(vm)	true
750 #else
751 
752 static bool
753 vmem_check_spanoverlap(const char *func, const vmem_t *vm,
754 			const bt_t *bt, const bt_t *bt2)
755 {
756 	switch (bt->bt_type) {
757 	case BT_TYPE_BUSY:
758 	case BT_TYPE_FREE:
759 		if (BT_ISSPAN_P(bt2))
760 			return true;
761 		break;
762 	case BT_TYPE_SPAN:
763 	case BT_TYPE_SPAN_STATIC:
764 		if (bt2->bt_type == BT_TYPE_BUSY
765 		   || bt2->bt_type == BT_TYPE_FREE)
766 			return true;
767 		break;
768 	}
769 
770 	if (bt->bt_start > bt2->bt_start) {
771 		if (bt->bt_start >= BT_END(bt2))
772 			return true;
773 
774 		printf("%s: overlapping VMEM '%s' span 0x%"
775 			PRIx64" - 0x%"PRIx64" %s\n",
776 			func, vm->vm_name,
777 			(uint64_t)bt->bt_start,
778 			(uint64_t)BT_END(bt),
779 			(bt->bt_type == BT_TYPE_BUSY) ?
780 			"allocated" :
781 			(bt->bt_type == BT_TYPE_FREE) ?
782 			"free" :
783 			(bt->bt_type == BT_TYPE_SPAN) ?
784 			"span" : "static span");
785 		printf("%s: overlapping VMEM '%s' span 0x%"
786 			PRIx64" - 0x%"PRIx64" %s\n",
787 			func, vm->vm_name,
788 			(uint64_t)bt2->bt_start,
789 			(uint64_t)BT_END(bt2),
790 			(bt2->bt_type == BT_TYPE_BUSY) ?
791 			"allocated" :
792 			(bt2->bt_type == BT_TYPE_FREE) ?
793 			"free" :
794 			(bt2->bt_type == BT_TYPE_SPAN) ?
795 			"span" : "static span");
796 		return false;
797 	}
798 	if (BT_END(bt) > bt2->bt_start) {
799 		printf("%s: overlapping VMEM '%s' span 0x%"
800 			PRIx64" - 0x%"PRIx64" %s\n",
801 			func, vm->vm_name,
802 			(uint64_t)bt->bt_start,
803 			(uint64_t)BT_END(bt),
804 			(bt->bt_type == BT_TYPE_BUSY) ?
805 			"allocated" :
806 			(bt->bt_type == BT_TYPE_FREE) ?
807 			"free" :
808 			(bt->bt_type == BT_TYPE_SPAN) ?
809 			"span" : "static span");
810 		printf("%s: overlapping VMEM '%s' span 0x%"
811 			PRIx64" - 0x%"PRIx64" %s\n",
812 			func, vm->vm_name,
813 			(uint64_t)bt2->bt_start,
814 			(uint64_t)BT_END(bt2),
815 			(bt2->bt_type == BT_TYPE_BUSY) ?
816 			"allocated" :
817 			(bt2->bt_type == BT_TYPE_FREE) ?
818 			"free" :
819 			(bt2->bt_type == BT_TYPE_SPAN) ?
820 			"span" : "static span");
821 		return false;
822 	}
823 
824 	return true;
825 }
826 
827 static bool
828 vmem_check_sanity(vmem_t *vm)
829 {
830 	const bt_t *bt, *bt2;
831 
832 	KASSERT(vm != NULL);
833 
834 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
835 		if (bt->bt_start >= BT_END(bt)) {
836 			printf("%s: bogus VMEM '%s' span 0x%"PRIx64
837 				" - 0x%"PRIx64" %s\n",
838 				__func__, vm->vm_name,
839 				(uint64_t)bt->bt_start, (uint64_t)BT_END(bt),
840 				(bt->bt_type == BT_TYPE_BUSY) ?
841 				"allocated" :
842 				(bt->bt_type == BT_TYPE_FREE) ?
843 				"free" :
844 				(bt->bt_type == BT_TYPE_SPAN) ?
845 				"span" : "static span");
846 			return false;
847 		}
848 
849 		CIRCLEQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) {
850 			if (bt2->bt_start >= BT_END(bt2)) {
851 				printf("%s: bogus VMEM '%s' span 0x%"PRIx64
852 					" - 0x%"PRIx64" %s\n",
853 					__func__, vm->vm_name,
854 					(uint64_t)bt2->bt_start,
855 					(uint64_t)BT_END(bt2),
856 					(bt2->bt_type == BT_TYPE_BUSY) ?
857 					"allocated" :
858 					(bt2->bt_type == BT_TYPE_FREE) ?
859 					"free" :
860 					(bt2->bt_type == BT_TYPE_SPAN) ?
861 					"span" : "static span");
862 				return false;
863 			}
864 			if (bt == bt2)
865 				continue;
866 
867 			if (vmem_check_spanoverlap(__func__, vm, bt, bt2)
868 				== false)
869 				return false;
870 		}
871 	}
872 
873 	return true;
874 }
875 #endif	/* VMEM_DEBUG */
876 
877 /* ---- vmem API */
878 
879 /*
880  * vmem_create: create an arena.
881  *
882  * => must not be called from interrupt context.
883  */
884 
885 vmem_t *
886 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
887     vmem_size_t quantum,
888     vmem_addr_t (*allocfn)(vmem_t *, vmem_size_t, vmem_size_t *, vm_flag_t),
889     void (*freefn)(vmem_t *, vmem_addr_t, vmem_size_t),
890     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags,
891     int ipl)
892 {
893 	vmem_t *vm;
894 	int i;
895 #if defined(_KERNEL)
896 	static ONCE_DECL(control);
897 #endif /* defined(_KERNEL) */
898 
899 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
900 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
901 
902 #if defined(_KERNEL)
903 	if (RUN_ONCE(&control, vmem_init)) {
904 		return NULL;
905 	}
906 #endif /* defined(_KERNEL) */
907 	vm = xmalloc(sizeof(*vm), flags);
908 	if (vm == NULL) {
909 		return NULL;
910 	}
911 
912 	VMEM_LOCK_INIT(vm, ipl);
913 	vm->vm_name = name;
914 	vm->vm_quantum_mask = quantum - 1;
915 	vm->vm_quantum_shift = calc_order(quantum);
916 	KASSERT(ORDER2SIZE(vm->vm_quantum_shift) == quantum);
917 	vm->vm_allocfn = allocfn;
918 	vm->vm_freefn = freefn;
919 	vm->vm_source = source;
920 	vm->vm_nbusytag = 0;
921 #if defined(QCACHE)
922 	qc_init(vm, qcache_max, ipl);
923 #endif /* defined(QCACHE) */
924 
925 	CIRCLEQ_INIT(&vm->vm_seglist);
926 	for (i = 0; i < VMEM_MAXORDER; i++) {
927 		LIST_INIT(&vm->vm_freelist[i]);
928 	}
929 	vm->vm_hashlist = NULL;
930 	if (vmem_rehash(vm, VMEM_HASHSIZE_INIT, flags)) {
931 		vmem_destroy1(vm);
932 		return NULL;
933 	}
934 
935 	if (size != 0) {
936 		if (vmem_add(vm, base, size, flags) == 0) {
937 			vmem_destroy1(vm);
938 			return NULL;
939 		}
940 	}
941 
942 #if defined(_KERNEL)
943 	mutex_enter(&vmem_list_lock);
944 	LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist);
945 	mutex_exit(&vmem_list_lock);
946 #endif /* defined(_KERNEL) */
947 
948 	return vm;
949 }
950 
951 void
952 vmem_destroy(vmem_t *vm)
953 {
954 
955 #if defined(_KERNEL)
956 	mutex_enter(&vmem_list_lock);
957 	LIST_REMOVE(vm, vm_alllist);
958 	mutex_exit(&vmem_list_lock);
959 #endif /* defined(_KERNEL) */
960 
961 	vmem_destroy1(vm);
962 }
963 
964 vmem_size_t
965 vmem_roundup_size(vmem_t *vm, vmem_size_t size)
966 {
967 
968 	return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
969 }
970 
971 /*
972  * vmem_alloc:
973  *
974  * => caller must ensure appropriate spl,
975  *    if the arena can be accessed from interrupt context.
976  */
977 
978 vmem_addr_t
979 vmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags)
980 {
981 	const vm_flag_t strat __unused = flags & VM_FITMASK;
982 
983 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
984 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
985 
986 	KASSERT(size > 0);
987 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
988 	if ((flags & VM_SLEEP) != 0) {
989 		ASSERT_SLEEPABLE();
990 	}
991 
992 #if defined(QCACHE)
993 	if (size <= vm->vm_qcache_max) {
994 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
995 		qcache_t *qc = vm->vm_qcache[qidx - 1];
996 
997 		return (vmem_addr_t)pool_cache_get(qc->qc_cache,
998 		    vmf_to_prf(flags));
999 	}
1000 #endif /* defined(QCACHE) */
1001 
1002 	return vmem_xalloc(vm, size, 0, 0, 0, 0, 0, flags);
1003 }
1004 
1005 vmem_addr_t
1006 vmem_xalloc(vmem_t *vm, vmem_size_t size0, vmem_size_t align, vmem_size_t phase,
1007     vmem_size_t nocross, vmem_addr_t minaddr, vmem_addr_t maxaddr,
1008     vm_flag_t flags)
1009 {
1010 	struct vmem_freelist *list;
1011 	struct vmem_freelist *first;
1012 	struct vmem_freelist *end;
1013 	bt_t *bt;
1014 	bt_t *btnew;
1015 	bt_t *btnew2;
1016 	const vmem_size_t size = vmem_roundup_size(vm, size0);
1017 	vm_flag_t strat = flags & VM_FITMASK;
1018 	vmem_addr_t start;
1019 
1020 	KASSERT(size0 > 0);
1021 	KASSERT(size > 0);
1022 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
1023 	if ((flags & VM_SLEEP) != 0) {
1024 		ASSERT_SLEEPABLE();
1025 	}
1026 	KASSERT((align & vm->vm_quantum_mask) == 0);
1027 	KASSERT((align & (align - 1)) == 0);
1028 	KASSERT((phase & vm->vm_quantum_mask) == 0);
1029 	KASSERT((nocross & vm->vm_quantum_mask) == 0);
1030 	KASSERT((nocross & (nocross - 1)) == 0);
1031 	KASSERT((align == 0 && phase == 0) || phase < align);
1032 	KASSERT(nocross == 0 || nocross >= size);
1033 	KASSERT(maxaddr == 0 || minaddr < maxaddr);
1034 	KASSERT(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
1035 
1036 	if (align == 0) {
1037 		align = vm->vm_quantum_mask + 1;
1038 	}
1039 	btnew = bt_alloc(vm, flags);
1040 	if (btnew == NULL) {
1041 		return VMEM_ADDR_NULL;
1042 	}
1043 	btnew2 = bt_alloc(vm, flags); /* XXX not necessary if no restrictions */
1044 	if (btnew2 == NULL) {
1045 		bt_free(vm, btnew);
1046 		return VMEM_ADDR_NULL;
1047 	}
1048 
1049 retry_strat:
1050 	first = bt_freehead_toalloc(vm, size, strat);
1051 	end = &vm->vm_freelist[VMEM_MAXORDER];
1052 retry:
1053 	bt = NULL;
1054 	VMEM_LOCK(vm);
1055 	KASSERT(vmem_check_sanity(vm));
1056 	if (strat == VM_INSTANTFIT) {
1057 		for (list = first; list < end; list++) {
1058 			bt = LIST_FIRST(list);
1059 			if (bt != NULL) {
1060 				start = vmem_fit(bt, size, align, phase,
1061 				    nocross, minaddr, maxaddr);
1062 				if (start != VMEM_ADDR_NULL) {
1063 					goto gotit;
1064 				}
1065 			}
1066 		}
1067 	} else { /* VM_BESTFIT */
1068 		for (list = first; list < end; list++) {
1069 			LIST_FOREACH(bt, list, bt_freelist) {
1070 				if (bt->bt_size >= size) {
1071 					start = vmem_fit(bt, size, align, phase,
1072 					    nocross, minaddr, maxaddr);
1073 					if (start != VMEM_ADDR_NULL) {
1074 						goto gotit;
1075 					}
1076 				}
1077 			}
1078 		}
1079 	}
1080 	VMEM_UNLOCK(vm);
1081 #if 1
1082 	if (strat == VM_INSTANTFIT) {
1083 		strat = VM_BESTFIT;
1084 		goto retry_strat;
1085 	}
1086 #endif
1087 	if (align != vm->vm_quantum_mask + 1 || phase != 0 ||
1088 	    nocross != 0 || minaddr != 0 || maxaddr != 0) {
1089 
1090 		/*
1091 		 * XXX should try to import a region large enough to
1092 		 * satisfy restrictions?
1093 		 */
1094 
1095 		goto fail;
1096 	}
1097 	if (vmem_import(vm, size, flags) == 0) {
1098 		goto retry;
1099 	}
1100 	/* XXX */
1101 fail:
1102 	bt_free(vm, btnew);
1103 	bt_free(vm, btnew2);
1104 	return VMEM_ADDR_NULL;
1105 
1106 gotit:
1107 	KASSERT(bt->bt_type == BT_TYPE_FREE);
1108 	KASSERT(bt->bt_size >= size);
1109 	bt_remfree(vm, bt);
1110 	KASSERT(vmem_check_sanity(vm));
1111 	if (bt->bt_start != start) {
1112 		btnew2->bt_type = BT_TYPE_FREE;
1113 		btnew2->bt_start = bt->bt_start;
1114 		btnew2->bt_size = start - bt->bt_start;
1115 		bt->bt_start = start;
1116 		bt->bt_size -= btnew2->bt_size;
1117 		bt_insfree(vm, btnew2);
1118 		bt_insseg(vm, btnew2, CIRCLEQ_PREV(bt, bt_seglist));
1119 		btnew2 = NULL;
1120 		KASSERT(vmem_check_sanity(vm));
1121 	}
1122 	KASSERT(bt->bt_start == start);
1123 	if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
1124 		/* split */
1125 		btnew->bt_type = BT_TYPE_BUSY;
1126 		btnew->bt_start = bt->bt_start;
1127 		btnew->bt_size = size;
1128 		bt->bt_start = bt->bt_start + size;
1129 		bt->bt_size -= size;
1130 		bt_insfree(vm, bt);
1131 		bt_insseg(vm, btnew, CIRCLEQ_PREV(bt, bt_seglist));
1132 		bt_insbusy(vm, btnew);
1133 		KASSERT(vmem_check_sanity(vm));
1134 		VMEM_UNLOCK(vm);
1135 	} else {
1136 		bt->bt_type = BT_TYPE_BUSY;
1137 		bt_insbusy(vm, bt);
1138 		KASSERT(vmem_check_sanity(vm));
1139 		VMEM_UNLOCK(vm);
1140 		bt_free(vm, btnew);
1141 		btnew = bt;
1142 	}
1143 	if (btnew2 != NULL) {
1144 		bt_free(vm, btnew2);
1145 	}
1146 	KASSERT(btnew->bt_size >= size);
1147 	btnew->bt_type = BT_TYPE_BUSY;
1148 
1149 	KASSERT(vmem_check_sanity(vm));
1150 	return btnew->bt_start;
1151 }
1152 
1153 /*
1154  * vmem_free:
1155  *
1156  * => caller must ensure appropriate spl,
1157  *    if the arena can be accessed from interrupt context.
1158  */
1159 
1160 void
1161 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1162 {
1163 
1164 	KASSERT(addr != VMEM_ADDR_NULL);
1165 	KASSERT(size > 0);
1166 
1167 #if defined(QCACHE)
1168 	if (size <= vm->vm_qcache_max) {
1169 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1170 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1171 
1172 		return pool_cache_put(qc->qc_cache, (void *)addr);
1173 	}
1174 #endif /* defined(QCACHE) */
1175 
1176 	vmem_xfree(vm, addr, size);
1177 }
1178 
1179 void
1180 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1181 {
1182 	bt_t *bt;
1183 	bt_t *t;
1184 
1185 	KASSERT(addr != VMEM_ADDR_NULL);
1186 	KASSERT(size > 0);
1187 
1188 	VMEM_LOCK(vm);
1189 
1190 	bt = bt_lookupbusy(vm, addr);
1191 	KASSERT(bt != NULL);
1192 	KASSERT(bt->bt_start == addr);
1193 	KASSERT(bt->bt_size == vmem_roundup_size(vm, size) ||
1194 	    bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
1195 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
1196 	bt_rembusy(vm, bt);
1197 	bt->bt_type = BT_TYPE_FREE;
1198 
1199 	/* coalesce */
1200 	t = CIRCLEQ_NEXT(bt, bt_seglist);
1201 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1202 		KASSERT(BT_END(bt) == t->bt_start);
1203 		bt_remfree(vm, t);
1204 		bt_remseg(vm, t);
1205 		bt->bt_size += t->bt_size;
1206 		bt_free(vm, t);
1207 	}
1208 	t = CIRCLEQ_PREV(bt, bt_seglist);
1209 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1210 		KASSERT(BT_END(t) == bt->bt_start);
1211 		bt_remfree(vm, t);
1212 		bt_remseg(vm, t);
1213 		bt->bt_size += t->bt_size;
1214 		bt->bt_start = t->bt_start;
1215 		bt_free(vm, t);
1216 	}
1217 
1218 	t = CIRCLEQ_PREV(bt, bt_seglist);
1219 	KASSERT(t != NULL);
1220 	KASSERT(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY);
1221 	if (vm->vm_freefn != NULL && t->bt_type == BT_TYPE_SPAN &&
1222 	    t->bt_size == bt->bt_size) {
1223 		vmem_addr_t spanaddr;
1224 		vmem_size_t spansize;
1225 
1226 		KASSERT(t->bt_start == bt->bt_start);
1227 		spanaddr = bt->bt_start;
1228 		spansize = bt->bt_size;
1229 		bt_remseg(vm, bt);
1230 		bt_free(vm, bt);
1231 		bt_remseg(vm, t);
1232 		bt_free(vm, t);
1233 		VMEM_UNLOCK(vm);
1234 		(*vm->vm_freefn)(vm->vm_source, spanaddr, spansize);
1235 	} else {
1236 		bt_insfree(vm, bt);
1237 		VMEM_UNLOCK(vm);
1238 	}
1239 }
1240 
1241 /*
1242  * vmem_add:
1243  *
1244  * => caller must ensure appropriate spl,
1245  *    if the arena can be accessed from interrupt context.
1246  */
1247 
1248 vmem_addr_t
1249 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags)
1250 {
1251 
1252 	return vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN_STATIC);
1253 }
1254 
1255 /*
1256  * vmem_reap: reap unused resources.
1257  *
1258  * => return true if we successfully reaped something.
1259  */
1260 
1261 bool
1262 vmem_reap(vmem_t *vm)
1263 {
1264 	bool didsomething = false;
1265 
1266 #if defined(QCACHE)
1267 	didsomething = qc_reap(vm);
1268 #endif /* defined(QCACHE) */
1269 	return didsomething;
1270 }
1271 
1272 /* ---- rehash */
1273 
1274 #if defined(_KERNEL)
1275 static struct callout vmem_rehash_ch;
1276 static int vmem_rehash_interval;
1277 static struct workqueue *vmem_rehash_wq;
1278 static struct work vmem_rehash_wk;
1279 
1280 static void
1281 vmem_rehash_all(struct work *wk, void *dummy)
1282 {
1283 	vmem_t *vm;
1284 
1285 	KASSERT(wk == &vmem_rehash_wk);
1286 	mutex_enter(&vmem_list_lock);
1287 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1288 		size_t desired;
1289 		size_t current;
1290 
1291 		if (!VMEM_TRYLOCK(vm)) {
1292 			continue;
1293 		}
1294 		desired = vm->vm_nbusytag;
1295 		current = vm->vm_hashsize;
1296 		VMEM_UNLOCK(vm);
1297 
1298 		if (desired > VMEM_HASHSIZE_MAX) {
1299 			desired = VMEM_HASHSIZE_MAX;
1300 		} else if (desired < VMEM_HASHSIZE_MIN) {
1301 			desired = VMEM_HASHSIZE_MIN;
1302 		}
1303 		if (desired > current * 2 || desired * 2 < current) {
1304 			vmem_rehash(vm, desired, VM_NOSLEEP);
1305 		}
1306 	}
1307 	mutex_exit(&vmem_list_lock);
1308 
1309 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1310 }
1311 
1312 static void
1313 vmem_rehash_all_kick(void *dummy)
1314 {
1315 
1316 	workqueue_enqueue(vmem_rehash_wq, &vmem_rehash_wk, NULL);
1317 }
1318 
1319 void
1320 vmem_rehash_start(void)
1321 {
1322 	int error;
1323 
1324 	error = workqueue_create(&vmem_rehash_wq, "vmem_rehash",
1325 	    vmem_rehash_all, NULL, PRI_VM, IPL_SOFTCLOCK, WQ_MPSAFE);
1326 	if (error) {
1327 		panic("%s: workqueue_create %d\n", __func__, error);
1328 	}
1329 	callout_init(&vmem_rehash_ch, CALLOUT_MPSAFE);
1330 	callout_setfunc(&vmem_rehash_ch, vmem_rehash_all_kick, NULL);
1331 
1332 	vmem_rehash_interval = hz * 10;
1333 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1334 }
1335 #endif /* defined(_KERNEL) */
1336 
1337 /* ---- debug */
1338 
1339 #if defined(DDB)
1340 static bt_t *
1341 vmem_whatis_lookup(vmem_t *vm, uintptr_t addr)
1342 {
1343 	bt_t *bt;
1344 
1345 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1346 		if (BT_ISSPAN_P(bt)) {
1347 			continue;
1348 		}
1349 		if (bt->bt_start <= addr && addr < BT_END(bt)) {
1350 			return bt;
1351 		}
1352 	}
1353 
1354 	return NULL;
1355 }
1356 
1357 void
1358 vmem_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1359 {
1360 	vmem_t *vm;
1361 
1362 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1363 		bt_t *bt;
1364 
1365 		bt = vmem_whatis_lookup(vm, addr);
1366 		if (bt == NULL) {
1367 			continue;
1368 		}
1369 		(*pr)("%p is %p+%zu in VMEM '%s' (%s)\n",
1370 		    (void *)addr, (void *)bt->bt_start,
1371 		    (size_t)(addr - bt->bt_start), vm->vm_name,
1372 		    (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free");
1373 	}
1374 }
1375 
1376 static void
1377 vmem_showall(void (*pr)(const char *, ...))
1378 {
1379 	vmem_t *vm;
1380 
1381 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1382 		(*pr)("VMEM '%s' at %p\n", vm->vm_name, vm);
1383 		if (vm->vm_source)
1384 			(*pr)("  VMEM backend '%s' at %p\n",
1385 				vm->vm_source->vm_name, vm->vm_source);
1386 	}
1387 }
1388 
1389 static void
1390 vmem_show(uintptr_t addr, void (*pr)(const char *, ...))
1391 {
1392 	vmem_t *vm;
1393 	bt_t *bt = NULL;
1394 
1395 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1396 		if ((uintptr_t)vm == addr)
1397 			goto found;
1398 	}
1399 
1400 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1401 		bt = vmem_whatis_lookup(vm, addr);
1402 		if (bt != NULL)
1403 			goto found;
1404 	}
1405 
1406 	return;
1407 found:
1408 
1409 	(*pr)("VMEM '%s' spans\n", vm->vm_name);
1410 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1411 		(*pr)(" 0x%"PRIx64" - 0x%"PRIx64" %s\n",
1412 			bt->bt_start, BT_END(bt),
1413 			(bt->bt_type == BT_TYPE_BUSY) ?
1414 			"allocated" :
1415 			(bt->bt_type == BT_TYPE_FREE) ?
1416 			"free" :
1417 			(bt->bt_type == BT_TYPE_SPAN) ?
1418 			"span" : "static span");
1419 	}
1420 }
1421 
1422 void
1423 vmem_print(uintptr_t addr, const char *modif, void (*pr)(const char *, ...))
1424 {
1425 	if (modif[0] == 'a') {
1426 		vmem_showall(pr);
1427 		return;
1428 	}
1429 
1430 	vmem_show(addr, pr);
1431 }
1432 #endif /* defined(DDB) */
1433 
1434 #if defined(VMEM_DEBUG)
1435 
1436 #if !defined(_KERNEL)
1437 #include <stdio.h>
1438 #endif /* !defined(_KERNEL) */
1439 
1440 void bt_dump(const bt_t *);
1441 
1442 void
1443 bt_dump(const bt_t *bt)
1444 {
1445 
1446 	printf("\t%p: %" PRIu64 ", %" PRIu64 ", %d\n",
1447 	    bt, (uint64_t)bt->bt_start, (uint64_t)bt->bt_size,
1448 	    bt->bt_type);
1449 }
1450 
1451 void
1452 vmem_dump(const vmem_t *vm)
1453 {
1454 	const bt_t *bt;
1455 	int i;
1456 
1457 	printf("vmem %p '%s'\n", vm, vm->vm_name);
1458 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1459 		bt_dump(bt);
1460 	}
1461 
1462 	for (i = 0; i < VMEM_MAXORDER; i++) {
1463 		const struct vmem_freelist *fl = &vm->vm_freelist[i];
1464 
1465 		if (LIST_EMPTY(fl)) {
1466 			continue;
1467 		}
1468 
1469 		printf("freelist[%d]\n", i);
1470 		LIST_FOREACH(bt, fl, bt_freelist) {
1471 			bt_dump(bt);
1472 			if (bt->bt_size) {
1473 			}
1474 		}
1475 	}
1476 }
1477 
1478 #if !defined(_KERNEL)
1479 
1480 int
1481 main()
1482 {
1483 	vmem_t *vm;
1484 	vmem_addr_t p;
1485 	struct reg {
1486 		vmem_addr_t p;
1487 		vmem_size_t sz;
1488 		bool x;
1489 	} *reg = NULL;
1490 	int nreg = 0;
1491 	int nalloc = 0;
1492 	int nfree = 0;
1493 	vmem_size_t total = 0;
1494 #if 1
1495 	vm_flag_t strat = VM_INSTANTFIT;
1496 #else
1497 	vm_flag_t strat = VM_BESTFIT;
1498 #endif
1499 
1500 	vm = vmem_create("test", VMEM_ADDR_NULL, 0, 1,
1501 	    NULL, NULL, NULL, 0, VM_SLEEP);
1502 	if (vm == NULL) {
1503 		printf("vmem_create\n");
1504 		exit(EXIT_FAILURE);
1505 	}
1506 	vmem_dump(vm);
1507 
1508 	p = vmem_add(vm, 100, 200, VM_SLEEP);
1509 	p = vmem_add(vm, 2000, 1, VM_SLEEP);
1510 	p = vmem_add(vm, 40000, 0x10000000>>12, VM_SLEEP);
1511 	p = vmem_add(vm, 10000, 10000, VM_SLEEP);
1512 	p = vmem_add(vm, 500, 1000, VM_SLEEP);
1513 	vmem_dump(vm);
1514 	for (;;) {
1515 		struct reg *r;
1516 		int t = rand() % 100;
1517 
1518 		if (t > 45) {
1519 			/* alloc */
1520 			vmem_size_t sz = rand() % 500 + 1;
1521 			bool x;
1522 			vmem_size_t align, phase, nocross;
1523 			vmem_addr_t minaddr, maxaddr;
1524 
1525 			if (t > 70) {
1526 				x = true;
1527 				/* XXX */
1528 				align = 1 << (rand() % 15);
1529 				phase = rand() % 65536;
1530 				nocross = 1 << (rand() % 15);
1531 				if (align <= phase) {
1532 					phase = 0;
1533 				}
1534 				if (VMEM_CROSS_P(phase, phase + sz - 1,
1535 				    nocross)) {
1536 					nocross = 0;
1537 				}
1538 				minaddr = rand() % 50000;
1539 				maxaddr = rand() % 70000;
1540 				if (minaddr > maxaddr) {
1541 					minaddr = 0;
1542 					maxaddr = 0;
1543 				}
1544 				printf("=== xalloc %" PRIu64
1545 				    " align=%" PRIu64 ", phase=%" PRIu64
1546 				    ", nocross=%" PRIu64 ", min=%" PRIu64
1547 				    ", max=%" PRIu64 "\n",
1548 				    (uint64_t)sz,
1549 				    (uint64_t)align,
1550 				    (uint64_t)phase,
1551 				    (uint64_t)nocross,
1552 				    (uint64_t)minaddr,
1553 				    (uint64_t)maxaddr);
1554 				p = vmem_xalloc(vm, sz, align, phase, nocross,
1555 				    minaddr, maxaddr, strat|VM_SLEEP);
1556 			} else {
1557 				x = false;
1558 				printf("=== alloc %" PRIu64 "\n", (uint64_t)sz);
1559 				p = vmem_alloc(vm, sz, strat|VM_SLEEP);
1560 			}
1561 			printf("-> %" PRIu64 "\n", (uint64_t)p);
1562 			vmem_dump(vm);
1563 			if (p == VMEM_ADDR_NULL) {
1564 				if (x) {
1565 					continue;
1566 				}
1567 				break;
1568 			}
1569 			nreg++;
1570 			reg = realloc(reg, sizeof(*reg) * nreg);
1571 			r = &reg[nreg - 1];
1572 			r->p = p;
1573 			r->sz = sz;
1574 			r->x = x;
1575 			total += sz;
1576 			nalloc++;
1577 		} else if (nreg != 0) {
1578 			/* free */
1579 			r = &reg[rand() % nreg];
1580 			printf("=== free %" PRIu64 ", %" PRIu64 "\n",
1581 			    (uint64_t)r->p, (uint64_t)r->sz);
1582 			if (r->x) {
1583 				vmem_xfree(vm, r->p, r->sz);
1584 			} else {
1585 				vmem_free(vm, r->p, r->sz);
1586 			}
1587 			total -= r->sz;
1588 			vmem_dump(vm);
1589 			*r = reg[nreg - 1];
1590 			nreg--;
1591 			nfree++;
1592 		}
1593 		printf("total=%" PRIu64 "\n", (uint64_t)total);
1594 	}
1595 	fprintf(stderr, "total=%" PRIu64 ", nalloc=%d, nfree=%d\n",
1596 	    (uint64_t)total, nalloc, nfree);
1597 	exit(EXIT_SUCCESS);
1598 }
1599 #endif /* !defined(_KERNEL) */
1600 #endif /* defined(VMEM_DEBUG) */
1601