xref: /netbsd-src/sys/kern/subr_vmem.c (revision c0179c282a5968435315a82f4128c61372c68fc3)
1 /*	$NetBSD: subr_vmem.c,v 1.24 2006/11/18 07:51:54 yamt Exp $	*/
2 
3 /*-
4  * Copyright (c)2006 YAMAMOTO Takashi,
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * reference:
31  * -	Magazines and Vmem: Extending the Slab Allocator
32  *	to Many CPUs and Arbitrary Resources
33  *	http://www.usenix.org/event/usenix01/bonwick.html
34  *
35  * todo:
36  * -	decide how to import segments for vmem_xalloc.
37  * -	don't rely on malloc(9).
38  */
39 
40 #include <sys/cdefs.h>
41 __KERNEL_RCSID(0, "$NetBSD: subr_vmem.c,v 1.24 2006/11/18 07:51:54 yamt Exp $");
42 
43 #define	VMEM_DEBUG
44 #if defined(_KERNEL)
45 #define	QCACHE
46 #endif /* defined(_KERNEL) */
47 
48 #include <sys/param.h>
49 #include <sys/hash.h>
50 #include <sys/queue.h>
51 
52 #if defined(_KERNEL)
53 #include <sys/systm.h>
54 #include <sys/lock.h>
55 #include <sys/malloc.h>
56 #include <sys/once.h>
57 #include <sys/pool.h>
58 #include <sys/proc.h>
59 #include <sys/vmem.h>
60 #else /* defined(_KERNEL) */
61 #include "../sys/vmem.h"
62 #endif /* defined(_KERNEL) */
63 
64 #if defined(_KERNEL)
65 #define	SIMPLELOCK_DECL(name)	struct simplelock name
66 #else /* defined(_KERNEL) */
67 #include <errno.h>
68 #include <assert.h>
69 #include <stdlib.h>
70 
71 #define	KASSERT(a)		assert(a)
72 #define	SIMPLELOCK_DECL(name)	/* nothing */
73 #define	LOCK_ASSERT(a)		/* nothing */
74 #define	simple_lock_init(a)	/* nothing */
75 #define	simple_lock(a)		/* nothing */
76 #define	simple_unlock(a)	/* nothing */
77 #define	ASSERT_SLEEPABLE(lk, msg) /* nothing */
78 #endif /* defined(_KERNEL) */
79 
80 struct vmem;
81 struct vmem_btag;
82 
83 #if defined(VMEM_DEBUG)
84 void vmem_dump(const vmem_t *);
85 #endif /* defined(VMEM_DEBUG) */
86 
87 #define	VMEM_MAXORDER		(sizeof(vmem_size_t) * CHAR_BIT)
88 #define	VMEM_HASHSIZE_INIT	4096	/* XXX */
89 
90 #define	VM_FITMASK	(VM_BESTFIT | VM_INSTANTFIT)
91 
92 CIRCLEQ_HEAD(vmem_seglist, vmem_btag);
93 LIST_HEAD(vmem_freelist, vmem_btag);
94 LIST_HEAD(vmem_hashlist, vmem_btag);
95 
96 #if defined(QCACHE)
97 #define	VMEM_QCACHE_IDX_MAX	32
98 
99 #define	QC_NAME_MAX	16
100 
101 struct qcache {
102 	struct pool qc_pool;
103 	struct pool_cache qc_cache;
104 	vmem_t *qc_vmem;
105 	char qc_name[QC_NAME_MAX];
106 };
107 typedef struct qcache qcache_t;
108 #define	QC_POOL_TO_QCACHE(pool)	((qcache_t *)(pool))
109 #endif /* defined(QCACHE) */
110 
111 /* vmem arena */
112 struct vmem {
113 	SIMPLELOCK_DECL(vm_lock);
114 	vmem_addr_t (*vm_allocfn)(vmem_t *, vmem_size_t, vmem_size_t *,
115 	    vm_flag_t);
116 	void (*vm_freefn)(vmem_t *, vmem_addr_t, vmem_size_t);
117 	vmem_t *vm_source;
118 	struct vmem_seglist vm_seglist;
119 	struct vmem_freelist vm_freelist[VMEM_MAXORDER];
120 	size_t vm_hashsize;
121 	size_t vm_nbusytag;
122 	struct vmem_hashlist *vm_hashlist;
123 	size_t vm_quantum_mask;
124 	int vm_quantum_shift;
125 	const char *vm_name;
126 
127 #if defined(QCACHE)
128 	/* quantum cache */
129 	size_t vm_qcache_max;
130 	struct pool_allocator vm_qcache_allocator;
131 	qcache_t vm_qcache_store[VMEM_QCACHE_IDX_MAX];
132 	qcache_t *vm_qcache[VMEM_QCACHE_IDX_MAX];
133 #endif /* defined(QCACHE) */
134 };
135 
136 #define	VMEM_LOCK(vm)	simple_lock(&vm->vm_lock)
137 #define	VMEM_UNLOCK(vm)	simple_unlock(&vm->vm_lock)
138 #define	VMEM_LOCK_INIT(vm)	simple_lock_init(&vm->vm_lock);
139 #define	VMEM_ASSERT_LOCKED(vm) \
140 	LOCK_ASSERT(simple_lock_held(&vm->vm_lock))
141 #define	VMEM_ASSERT_UNLOCKED(vm) \
142 	LOCK_ASSERT(!simple_lock_held(&vm->vm_lock))
143 
144 /* boundary tag */
145 struct vmem_btag {
146 	CIRCLEQ_ENTRY(vmem_btag) bt_seglist;
147 	union {
148 		LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */
149 		LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */
150 	} bt_u;
151 #define	bt_hashlist	bt_u.u_hashlist
152 #define	bt_freelist	bt_u.u_freelist
153 	vmem_addr_t bt_start;
154 	vmem_size_t bt_size;
155 	int bt_type;
156 };
157 
158 #define	BT_TYPE_SPAN		1
159 #define	BT_TYPE_SPAN_STATIC	2
160 #define	BT_TYPE_FREE		3
161 #define	BT_TYPE_BUSY		4
162 #define	BT_ISSPAN_P(bt)	((bt)->bt_type <= BT_TYPE_SPAN_STATIC)
163 
164 #define	BT_END(bt)	((bt)->bt_start + (bt)->bt_size)
165 
166 typedef struct vmem_btag bt_t;
167 
168 /* ---- misc */
169 
170 #define	VMEM_ALIGNUP(addr, align) \
171 	(-(-(addr) & -(align)))
172 #define	VMEM_CROSS_P(addr1, addr2, boundary) \
173 	((((addr1) ^ (addr2)) & -(boundary)) != 0)
174 
175 #define	ORDER2SIZE(order)	((vmem_size_t)1 << (order))
176 
177 static int
178 calc_order(vmem_size_t size)
179 {
180 	vmem_size_t target;
181 	int i;
182 
183 	KASSERT(size != 0);
184 
185 	i = 0;
186 	target = size >> 1;
187 	while (ORDER2SIZE(i) <= target) {
188 		i++;
189 	}
190 
191 	KASSERT(ORDER2SIZE(i) <= size);
192 	KASSERT(size < ORDER2SIZE(i + 1) || ORDER2SIZE(i + 1) < ORDER2SIZE(i));
193 
194 	return i;
195 }
196 
197 #if defined(_KERNEL)
198 static MALLOC_DEFINE(M_VMEM, "vmem", "vmem");
199 #endif /* defined(_KERNEL) */
200 
201 static void *
202 xmalloc(size_t sz, vm_flag_t flags)
203 {
204 
205 #if defined(_KERNEL)
206 	return malloc(sz, M_VMEM,
207 	    M_CANFAIL | ((flags & VM_SLEEP) ? M_WAITOK : M_NOWAIT));
208 #else /* defined(_KERNEL) */
209 	return malloc(sz);
210 #endif /* defined(_KERNEL) */
211 }
212 
213 static void
214 xfree(void *p)
215 {
216 
217 #if defined(_KERNEL)
218 	return free(p, M_VMEM);
219 #else /* defined(_KERNEL) */
220 	return free(p);
221 #endif /* defined(_KERNEL) */
222 }
223 
224 /* ---- boundary tag */
225 
226 #if defined(_KERNEL)
227 static struct pool_cache bt_poolcache;
228 static POOL_INIT(bt_pool, sizeof(bt_t), 0, 0, 0, "vmembtpl", NULL);
229 #endif /* defined(_KERNEL) */
230 
231 static bt_t *
232 bt_alloc(vmem_t *vm, vm_flag_t flags)
233 {
234 	bt_t *bt;
235 
236 #if defined(_KERNEL)
237 	int s;
238 
239 	/* XXX bootstrap */
240 	s = splvm();
241 	bt = pool_cache_get(&bt_poolcache,
242 	    (flags & VM_SLEEP) != 0 ? PR_WAITOK : PR_NOWAIT);
243 	splx(s);
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 	int s;
257 
258 	/* XXX bootstrap */
259 	s = splvm();
260 	pool_cache_put(&bt_poolcache, bt);
261 	splx(s);
262 #else /* defined(_KERNEL) */
263 	free(bt);
264 #endif /* defined(_KERNEL) */
265 }
266 
267 /*
268  * freelist[0] ... [1, 1]
269  * freelist[1] ... [2, 3]
270  * freelist[2] ... [4, 7]
271  * freelist[3] ... [8, 15]
272  *  :
273  * freelist[n] ... [(1 << n), (1 << (n + 1)) - 1]
274  *  :
275  */
276 
277 static struct vmem_freelist *
278 bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
279 {
280 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
281 	int idx;
282 
283 	KASSERT((size & vm->vm_quantum_mask) == 0);
284 	KASSERT(size != 0);
285 
286 	idx = calc_order(qsize);
287 	KASSERT(idx >= 0);
288 	KASSERT(idx < VMEM_MAXORDER);
289 
290 	return &vm->vm_freelist[idx];
291 }
292 
293 static struct vmem_freelist *
294 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, vm_flag_t strat)
295 {
296 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
297 	int idx;
298 
299 	KASSERT((size & vm->vm_quantum_mask) == 0);
300 	KASSERT(size != 0);
301 
302 	idx = calc_order(qsize);
303 	if (strat == VM_INSTANTFIT && ORDER2SIZE(idx) != qsize) {
304 		idx++;
305 		/* check too large request? */
306 	}
307 	KASSERT(idx >= 0);
308 	KASSERT(idx < VMEM_MAXORDER);
309 
310 	return &vm->vm_freelist[idx];
311 }
312 
313 /* ---- boundary tag hash */
314 
315 static struct vmem_hashlist *
316 bt_hashhead(vmem_t *vm, vmem_addr_t addr)
317 {
318 	struct vmem_hashlist *list;
319 	unsigned int hash;
320 
321 	hash = hash32_buf(&addr, sizeof(addr), HASH32_BUF_INIT);
322 	list = &vm->vm_hashlist[hash % vm->vm_hashsize];
323 
324 	return list;
325 }
326 
327 static bt_t *
328 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
329 {
330 	struct vmem_hashlist *list;
331 	bt_t *bt;
332 
333 	list = bt_hashhead(vm, addr);
334 	LIST_FOREACH(bt, list, bt_hashlist) {
335 		if (bt->bt_start == addr) {
336 			break;
337 		}
338 	}
339 
340 	return bt;
341 }
342 
343 static void
344 bt_rembusy(vmem_t *vm, bt_t *bt)
345 {
346 
347 	KASSERT(vm->vm_nbusytag > 0);
348 	vm->vm_nbusytag--;
349 	LIST_REMOVE(bt, bt_hashlist);
350 }
351 
352 static void
353 bt_insbusy(vmem_t *vm, bt_t *bt)
354 {
355 	struct vmem_hashlist *list;
356 
357 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
358 
359 	list = bt_hashhead(vm, bt->bt_start);
360 	LIST_INSERT_HEAD(list, bt, bt_hashlist);
361 	vm->vm_nbusytag++;
362 }
363 
364 /* ---- boundary tag list */
365 
366 static void
367 bt_remseg(vmem_t *vm, bt_t *bt)
368 {
369 
370 	CIRCLEQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
371 }
372 
373 static void
374 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
375 {
376 
377 	CIRCLEQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
378 }
379 
380 static void
381 bt_insseg_tail(vmem_t *vm, bt_t *bt)
382 {
383 
384 	CIRCLEQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
385 }
386 
387 static void
388 bt_remfree(vmem_t *vm, bt_t *bt)
389 {
390 
391 	KASSERT(bt->bt_type == BT_TYPE_FREE);
392 
393 	LIST_REMOVE(bt, bt_freelist);
394 }
395 
396 static void
397 bt_insfree(vmem_t *vm, bt_t *bt)
398 {
399 	struct vmem_freelist *list;
400 
401 	list = bt_freehead_tofree(vm, bt->bt_size);
402 	LIST_INSERT_HEAD(list, bt, bt_freelist);
403 }
404 
405 /* ---- vmem internal functions */
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)
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 		pool_init(&qc->qc_pool, size, ORDER2SIZE(vm->vm_quantum_shift),
494 		    0, PR_NOALIGN | PR_NOTOUCH /* XXX */, qc->qc_name, pa);
495 		if (prevqc != NULL &&
496 		    qc->qc_pool.pr_itemsperpage ==
497 		    prevqc->qc_pool.pr_itemsperpage) {
498 			pool_destroy(&qc->qc_pool);
499 			vm->vm_qcache[i - 1] = prevqc;
500 		}
501 		pool_cache_init(&qc->qc_cache, &qc->qc_pool, NULL, NULL, NULL);
502 		vm->vm_qcache[i - 1] = qc;
503 		prevqc = qc;
504 	}
505 }
506 
507 static void
508 qc_destroy(vmem_t *vm)
509 {
510 	const qcache_t *prevqc;
511 	int i;
512 	int qcache_idx_max;
513 
514 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
515 	prevqc = NULL;
516 	for (i = 0; i < qcache_idx_max; i++) {
517 		qcache_t *qc = vm->vm_qcache[i];
518 
519 		if (prevqc == qc) {
520 			continue;
521 		}
522 		pool_cache_destroy(&qc->qc_cache);
523 		pool_destroy(&qc->qc_pool);
524 		prevqc = qc;
525 	}
526 }
527 
528 static boolean_t
529 qc_reap(vmem_t *vm)
530 {
531 	const qcache_t *prevqc;
532 	int i;
533 	int qcache_idx_max;
534 	boolean_t didsomething = FALSE;
535 
536 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
537 	prevqc = NULL;
538 	for (i = 0; i < qcache_idx_max; i++) {
539 		qcache_t *qc = vm->vm_qcache[i];
540 
541 		if (prevqc == qc) {
542 			continue;
543 		}
544 		if (pool_reclaim(&qc->qc_pool) != 0) {
545 			didsomething = TRUE;
546 		}
547 		prevqc = qc;
548 	}
549 
550 	return didsomething;
551 }
552 #endif /* defined(QCACHE) */
553 
554 #if defined(_KERNEL)
555 static int
556 vmem_init(void)
557 {
558 
559 	pool_cache_init(&bt_poolcache, &bt_pool, NULL, NULL, NULL);
560 	return 0;
561 }
562 #endif /* defined(_KERNEL) */
563 
564 static vmem_addr_t
565 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags,
566     int spanbttype)
567 {
568 	bt_t *btspan;
569 	bt_t *btfree;
570 
571 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
572 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
573 	VMEM_ASSERT_UNLOCKED(vm);
574 
575 	btspan = bt_alloc(vm, flags);
576 	if (btspan == NULL) {
577 		return VMEM_ADDR_NULL;
578 	}
579 	btfree = bt_alloc(vm, flags);
580 	if (btfree == NULL) {
581 		bt_free(vm, btspan);
582 		return VMEM_ADDR_NULL;
583 	}
584 
585 	btspan->bt_type = spanbttype;
586 	btspan->bt_start = addr;
587 	btspan->bt_size = size;
588 
589 	btfree->bt_type = BT_TYPE_FREE;
590 	btfree->bt_start = addr;
591 	btfree->bt_size = size;
592 
593 	VMEM_LOCK(vm);
594 	bt_insseg_tail(vm, btspan);
595 	bt_insseg(vm, btfree, btspan);
596 	bt_insfree(vm, btfree);
597 	VMEM_UNLOCK(vm);
598 
599 	return addr;
600 }
601 
602 static int
603 vmem_import(vmem_t *vm, vmem_size_t size, vm_flag_t flags)
604 {
605 	vmem_addr_t addr;
606 
607 	VMEM_ASSERT_UNLOCKED(vm);
608 
609 	if (vm->vm_allocfn == NULL) {
610 		return EINVAL;
611 	}
612 
613 	addr = (*vm->vm_allocfn)(vm->vm_source, size, &size, flags);
614 	if (addr == VMEM_ADDR_NULL) {
615 		return ENOMEM;
616 	}
617 
618 	if (vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN) == VMEM_ADDR_NULL) {
619 		(*vm->vm_freefn)(vm->vm_source, addr, size);
620 		return ENOMEM;
621 	}
622 
623 	return 0;
624 }
625 
626 static int
627 vmem_rehash(vmem_t *vm, size_t newhashsize, vm_flag_t flags)
628 {
629 	bt_t *bt;
630 	int i;
631 	struct vmem_hashlist *newhashlist;
632 	struct vmem_hashlist *oldhashlist;
633 	size_t oldhashsize;
634 
635 	KASSERT(newhashsize > 0);
636 	VMEM_ASSERT_UNLOCKED(vm);
637 
638 	newhashlist =
639 	    xmalloc(sizeof(struct vmem_hashlist *) * newhashsize, flags);
640 	if (newhashlist == NULL) {
641 		return ENOMEM;
642 	}
643 	for (i = 0; i < newhashsize; i++) {
644 		LIST_INIT(&newhashlist[i]);
645 	}
646 
647 	VMEM_LOCK(vm);
648 	oldhashlist = vm->vm_hashlist;
649 	oldhashsize = vm->vm_hashsize;
650 	vm->vm_hashlist = newhashlist;
651 	vm->vm_hashsize = newhashsize;
652 	if (oldhashlist == NULL) {
653 		VMEM_UNLOCK(vm);
654 		return 0;
655 	}
656 	for (i = 0; i < oldhashsize; i++) {
657 		while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
658 			bt_rembusy(vm, bt); /* XXX */
659 			bt_insbusy(vm, bt);
660 		}
661 	}
662 	VMEM_UNLOCK(vm);
663 
664 	xfree(oldhashlist);
665 
666 	return 0;
667 }
668 
669 /*
670  * vmem_fit: check if a bt can satisfy the given restrictions.
671  */
672 
673 static vmem_addr_t
674 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align, vmem_size_t phase,
675     vmem_size_t nocross, vmem_addr_t minaddr, vmem_addr_t maxaddr)
676 {
677 	vmem_addr_t start;
678 	vmem_addr_t end;
679 
680 	KASSERT(bt->bt_size >= size);
681 
682 	/*
683 	 * XXX assumption: vmem_addr_t and vmem_size_t are
684 	 * unsigned integer of the same size.
685 	 */
686 
687 	start = bt->bt_start;
688 	if (start < minaddr) {
689 		start = minaddr;
690 	}
691 	end = BT_END(bt);
692 	if (end > maxaddr - 1) {
693 		end = maxaddr - 1;
694 	}
695 	if (start >= end) {
696 		return VMEM_ADDR_NULL;
697 	}
698 
699 	start = VMEM_ALIGNUP(start - phase, align) + phase;
700 	if (start < bt->bt_start) {
701 		start += align;
702 	}
703 	if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
704 		KASSERT(align < nocross);
705 		start = VMEM_ALIGNUP(start - phase, nocross) + phase;
706 	}
707 	if (start < end && end - start >= size) {
708 		KASSERT((start & (align - 1)) == phase);
709 		KASSERT(!VMEM_CROSS_P(start, start + size - 1, nocross));
710 		KASSERT(minaddr <= start);
711 		KASSERT(maxaddr == 0 || start + size <= maxaddr);
712 		KASSERT(bt->bt_start <= start);
713 		KASSERT(start + size <= BT_END(bt));
714 		return start;
715 	}
716 	return VMEM_ADDR_NULL;
717 }
718 
719 /* ---- vmem API */
720 
721 /*
722  * vmem_create: create an arena.
723  *
724  * => must not be called from interrupt context.
725  */
726 
727 vmem_t *
728 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
729     vmem_size_t quantum,
730     vmem_addr_t (*allocfn)(vmem_t *, vmem_size_t, vmem_size_t *, vm_flag_t),
731     void (*freefn)(vmem_t *, vmem_addr_t, vmem_size_t),
732     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags)
733 {
734 	vmem_t *vm;
735 	int i;
736 #if defined(_KERNEL)
737 	static ONCE_DECL(control);
738 #endif /* defined(_KERNEL) */
739 
740 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
741 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
742 
743 #if defined(_KERNEL)
744 	if (RUN_ONCE(&control, vmem_init)) {
745 		return NULL;
746 	}
747 #endif /* defined(_KERNEL) */
748 	vm = xmalloc(sizeof(*vm), flags);
749 	if (vm == NULL) {
750 		return NULL;
751 	}
752 
753 	VMEM_LOCK_INIT(vm);
754 	vm->vm_name = name;
755 	vm->vm_quantum_mask = quantum - 1;
756 	vm->vm_quantum_shift = calc_order(quantum);
757 	KASSERT(ORDER2SIZE(vm->vm_quantum_shift) == quantum);
758 	vm->vm_allocfn = allocfn;
759 	vm->vm_freefn = freefn;
760 	vm->vm_source = source;
761 	vm->vm_nbusytag = 0;
762 #if defined(QCACHE)
763 	qc_init(vm, qcache_max);
764 #endif /* defined(QCACHE) */
765 
766 	CIRCLEQ_INIT(&vm->vm_seglist);
767 	for (i = 0; i < VMEM_MAXORDER; i++) {
768 		LIST_INIT(&vm->vm_freelist[i]);
769 	}
770 	vm->vm_hashlist = NULL;
771 	if (vmem_rehash(vm, VMEM_HASHSIZE_INIT, flags)) {
772 		vmem_destroy(vm);
773 		return NULL;
774 	}
775 
776 	if (size != 0) {
777 		if (vmem_add(vm, base, size, flags) == 0) {
778 			vmem_destroy(vm);
779 			return NULL;
780 		}
781 	}
782 
783 	return vm;
784 }
785 
786 void
787 vmem_destroy(vmem_t *vm)
788 {
789 
790 	VMEM_ASSERT_UNLOCKED(vm);
791 
792 #if defined(QCACHE)
793 	qc_destroy(vm);
794 #endif /* defined(QCACHE) */
795 	if (vm->vm_hashlist != NULL) {
796 		int i;
797 
798 		for (i = 0; i < vm->vm_hashsize; i++) {
799 			bt_t *bt;
800 
801 			while ((bt = LIST_FIRST(&vm->vm_hashlist[i])) != NULL) {
802 				KASSERT(bt->bt_type == BT_TYPE_SPAN_STATIC);
803 				bt_free(vm, bt);
804 			}
805 		}
806 		xfree(vm->vm_hashlist);
807 	}
808 	xfree(vm);
809 }
810 
811 vmem_size_t
812 vmem_roundup_size(vmem_t *vm, vmem_size_t size)
813 {
814 
815 	return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
816 }
817 
818 /*
819  * vmem_alloc:
820  *
821  * => caller must ensure appropriate spl,
822  *    if the arena can be accessed from interrupt context.
823  */
824 
825 vmem_addr_t
826 vmem_alloc(vmem_t *vm, vmem_size_t size0, vm_flag_t flags)
827 {
828 	const vmem_size_t size __unused = vmem_roundup_size(vm, size0);
829 	const vm_flag_t strat __unused = flags & VM_FITMASK;
830 
831 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
832 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
833 	VMEM_ASSERT_UNLOCKED(vm);
834 
835 	KASSERT(size0 > 0);
836 	KASSERT(size > 0);
837 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
838 	if ((flags & VM_SLEEP) != 0) {
839 		ASSERT_SLEEPABLE(NULL, __func__);
840 	}
841 
842 #if defined(QCACHE)
843 	if (size <= vm->vm_qcache_max) {
844 		int qidx = size >> vm->vm_quantum_shift;
845 		qcache_t *qc = vm->vm_qcache[qidx - 1];
846 
847 		return (vmem_addr_t)pool_cache_get(&qc->qc_cache,
848 		    vmf_to_prf(flags));
849 	}
850 #endif /* defined(QCACHE) */
851 
852 	return vmem_xalloc(vm, size0, 0, 0, 0, 0, 0, flags);
853 }
854 
855 vmem_addr_t
856 vmem_xalloc(vmem_t *vm, vmem_size_t size0, vmem_size_t align, vmem_size_t phase,
857     vmem_size_t nocross, vmem_addr_t minaddr, vmem_addr_t maxaddr,
858     vm_flag_t flags)
859 {
860 	struct vmem_freelist *list;
861 	struct vmem_freelist *first;
862 	struct vmem_freelist *end;
863 	bt_t *bt;
864 	bt_t *btnew;
865 	bt_t *btnew2;
866 	const vmem_size_t size = vmem_roundup_size(vm, size0);
867 	vm_flag_t strat = flags & VM_FITMASK;
868 	vmem_addr_t start;
869 
870 	KASSERT(size0 > 0);
871 	KASSERT(size > 0);
872 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
873 	if ((flags & VM_SLEEP) != 0) {
874 		ASSERT_SLEEPABLE(NULL, __func__);
875 	}
876 	KASSERT((align & vm->vm_quantum_mask) == 0);
877 	KASSERT((align & (align - 1)) == 0);
878 	KASSERT((phase & vm->vm_quantum_mask) == 0);
879 	KASSERT((nocross & vm->vm_quantum_mask) == 0);
880 	KASSERT((nocross & (nocross - 1)) == 0);
881 	KASSERT((align == 0 && phase == 0) || phase < align);
882 	KASSERT(nocross == 0 || nocross >= size);
883 	KASSERT(maxaddr == 0 || minaddr < maxaddr);
884 	KASSERT(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
885 
886 	if (align == 0) {
887 		align = vm->vm_quantum_mask + 1;
888 	}
889 	btnew = bt_alloc(vm, flags);
890 	if (btnew == NULL) {
891 		return VMEM_ADDR_NULL;
892 	}
893 	btnew2 = bt_alloc(vm, flags); /* XXX not necessary if no restrictions */
894 	if (btnew2 == NULL) {
895 		bt_free(vm, btnew);
896 		return VMEM_ADDR_NULL;
897 	}
898 
899 retry_strat:
900 	first = bt_freehead_toalloc(vm, size, strat);
901 	end = &vm->vm_freelist[VMEM_MAXORDER];
902 retry:
903 	bt = NULL;
904 	VMEM_LOCK(vm);
905 	if (strat == VM_INSTANTFIT) {
906 		for (list = first; list < end; list++) {
907 			bt = LIST_FIRST(list);
908 			if (bt != NULL) {
909 				start = vmem_fit(bt, size, align, phase,
910 				    nocross, minaddr, maxaddr);
911 				if (start != VMEM_ADDR_NULL) {
912 					goto gotit;
913 				}
914 			}
915 		}
916 	} else { /* VM_BESTFIT */
917 		for (list = first; list < end; list++) {
918 			LIST_FOREACH(bt, list, bt_freelist) {
919 				if (bt->bt_size >= size) {
920 					start = vmem_fit(bt, size, align, phase,
921 					    nocross, minaddr, maxaddr);
922 					if (start != VMEM_ADDR_NULL) {
923 						goto gotit;
924 					}
925 				}
926 			}
927 		}
928 	}
929 	VMEM_UNLOCK(vm);
930 #if 1
931 	if (strat == VM_INSTANTFIT) {
932 		strat = VM_BESTFIT;
933 		goto retry_strat;
934 	}
935 #endif
936 	if (align != vm->vm_quantum_mask + 1 || phase != 0 ||
937 	    nocross != 0 || minaddr != 0 || maxaddr != 0) {
938 
939 		/*
940 		 * XXX should try to import a region large enough to
941 		 * satisfy restrictions?
942 		 */
943 
944 		goto fail;
945 	}
946 	if (vmem_import(vm, size, flags) == 0) {
947 		goto retry;
948 	}
949 	/* XXX */
950 fail:
951 	bt_free(vm, btnew);
952 	bt_free(vm, btnew2);
953 	return VMEM_ADDR_NULL;
954 
955 gotit:
956 	KASSERT(bt->bt_type == BT_TYPE_FREE);
957 	KASSERT(bt->bt_size >= size);
958 	bt_remfree(vm, bt);
959 	if (bt->bt_start != start) {
960 		btnew2->bt_type = BT_TYPE_FREE;
961 		btnew2->bt_start = bt->bt_start;
962 		btnew2->bt_size = start - bt->bt_start;
963 		bt->bt_start = start;
964 		bt->bt_size -= btnew2->bt_size;
965 		bt_insfree(vm, btnew2);
966 		bt_insseg(vm, btnew2, CIRCLEQ_PREV(bt, bt_seglist));
967 		btnew2 = NULL;
968 	}
969 	KASSERT(bt->bt_start == start);
970 	if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
971 		/* split */
972 		btnew->bt_type = BT_TYPE_BUSY;
973 		btnew->bt_start = bt->bt_start;
974 		btnew->bt_size = size;
975 		bt->bt_start = bt->bt_start + size;
976 		bt->bt_size -= size;
977 		bt_insfree(vm, bt);
978 		bt_insseg(vm, btnew, CIRCLEQ_PREV(bt, bt_seglist));
979 		bt_insbusy(vm, btnew);
980 		VMEM_UNLOCK(vm);
981 	} else {
982 		bt->bt_type = BT_TYPE_BUSY;
983 		bt_insbusy(vm, bt);
984 		VMEM_UNLOCK(vm);
985 		bt_free(vm, btnew);
986 		btnew = bt;
987 	}
988 	if (btnew2 != NULL) {
989 		bt_free(vm, btnew2);
990 	}
991 	KASSERT(btnew->bt_size >= size);
992 	btnew->bt_type = BT_TYPE_BUSY;
993 
994 	return btnew->bt_start;
995 }
996 
997 /*
998  * vmem_free:
999  *
1000  * => caller must ensure appropriate spl,
1001  *    if the arena can be accessed from interrupt context.
1002  */
1003 
1004 void
1005 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1006 {
1007 
1008 	VMEM_ASSERT_UNLOCKED(vm);
1009 	KASSERT(addr != VMEM_ADDR_NULL);
1010 	KASSERT(size > 0);
1011 
1012 #if defined(QCACHE)
1013 	if (size <= vm->vm_qcache_max) {
1014 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1015 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1016 
1017 		return pool_cache_put(&qc->qc_cache, (void *)addr);
1018 	}
1019 #endif /* defined(QCACHE) */
1020 
1021 	vmem_xfree(vm, addr, size);
1022 }
1023 
1024 void
1025 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1026 {
1027 	bt_t *bt;
1028 	bt_t *t;
1029 
1030 	VMEM_ASSERT_UNLOCKED(vm);
1031 	KASSERT(addr != VMEM_ADDR_NULL);
1032 	KASSERT(size > 0);
1033 
1034 	VMEM_LOCK(vm);
1035 
1036 	bt = bt_lookupbusy(vm, addr);
1037 	KASSERT(bt != NULL);
1038 	KASSERT(bt->bt_start == addr);
1039 	KASSERT(bt->bt_size == vmem_roundup_size(vm, size) ||
1040 	    bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
1041 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
1042 	bt_rembusy(vm, bt);
1043 	bt->bt_type = BT_TYPE_FREE;
1044 
1045 	/* coalesce */
1046 	t = CIRCLEQ_NEXT(bt, bt_seglist);
1047 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1048 		KASSERT(BT_END(bt) == t->bt_start);
1049 		bt_remfree(vm, t);
1050 		bt_remseg(vm, t);
1051 		bt->bt_size += t->bt_size;
1052 		bt_free(vm, t);
1053 	}
1054 	t = CIRCLEQ_PREV(bt, bt_seglist);
1055 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1056 		KASSERT(BT_END(t) == bt->bt_start);
1057 		bt_remfree(vm, t);
1058 		bt_remseg(vm, t);
1059 		bt->bt_size += t->bt_size;
1060 		bt->bt_start = t->bt_start;
1061 		bt_free(vm, t);
1062 	}
1063 
1064 	t = CIRCLEQ_PREV(bt, bt_seglist);
1065 	KASSERT(t != NULL);
1066 	KASSERT(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY);
1067 	if (vm->vm_freefn != NULL && t->bt_type == BT_TYPE_SPAN &&
1068 	    t->bt_size == bt->bt_size) {
1069 		vmem_addr_t spanaddr;
1070 		vmem_size_t spansize;
1071 
1072 		KASSERT(t->bt_start == bt->bt_start);
1073 		spanaddr = bt->bt_start;
1074 		spansize = bt->bt_size;
1075 		bt_remseg(vm, bt);
1076 		bt_free(vm, bt);
1077 		bt_remseg(vm, t);
1078 		bt_free(vm, t);
1079 		VMEM_UNLOCK(vm);
1080 		(*vm->vm_freefn)(vm->vm_source, spanaddr, spansize);
1081 	} else {
1082 		bt_insfree(vm, bt);
1083 		VMEM_UNLOCK(vm);
1084 	}
1085 }
1086 
1087 /*
1088  * vmem_add:
1089  *
1090  * => caller must ensure appropriate spl,
1091  *    if the arena can be accessed from interrupt context.
1092  */
1093 
1094 vmem_addr_t
1095 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags)
1096 {
1097 
1098 	return vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN_STATIC);
1099 }
1100 
1101 /*
1102  * vmem_reap: reap unused resources.
1103  *
1104  * => return TRUE if we successfully reaped something.
1105  */
1106 
1107 boolean_t
1108 vmem_reap(vmem_t *vm)
1109 {
1110 	boolean_t didsomething = FALSE;
1111 
1112 	VMEM_ASSERT_UNLOCKED(vm);
1113 
1114 #if defined(QCACHE)
1115 	didsomething = qc_reap(vm);
1116 #endif /* defined(QCACHE) */
1117 	return didsomething;
1118 }
1119 
1120 /* ---- debug */
1121 
1122 #if defined(VMEM_DEBUG)
1123 
1124 #if !defined(_KERNEL)
1125 #include <stdio.h>
1126 #endif /* !defined(_KERNEL) */
1127 
1128 void bt_dump(const bt_t *);
1129 
1130 void
1131 bt_dump(const bt_t *bt)
1132 {
1133 
1134 	printf("\t%p: %" PRIu64 ", %" PRIu64 ", %d\n",
1135 	    bt, (uint64_t)bt->bt_start, (uint64_t)bt->bt_size,
1136 	    bt->bt_type);
1137 }
1138 
1139 void
1140 vmem_dump(const vmem_t *vm)
1141 {
1142 	const bt_t *bt;
1143 	int i;
1144 
1145 	printf("vmem %p '%s'\n", vm, vm->vm_name);
1146 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1147 		bt_dump(bt);
1148 	}
1149 
1150 	for (i = 0; i < VMEM_MAXORDER; i++) {
1151 		const struct vmem_freelist *fl = &vm->vm_freelist[i];
1152 
1153 		if (LIST_EMPTY(fl)) {
1154 			continue;
1155 		}
1156 
1157 		printf("freelist[%d]\n", i);
1158 		LIST_FOREACH(bt, fl, bt_freelist) {
1159 			bt_dump(bt);
1160 			if (bt->bt_size) {
1161 			}
1162 		}
1163 	}
1164 }
1165 
1166 #if !defined(_KERNEL)
1167 
1168 #include <stdlib.h>
1169 
1170 int
1171 main()
1172 {
1173 	vmem_t *vm;
1174 	vmem_addr_t p;
1175 	struct reg {
1176 		vmem_addr_t p;
1177 		vmem_size_t sz;
1178 		boolean_t x;
1179 	} *reg = NULL;
1180 	int nreg = 0;
1181 	int nalloc = 0;
1182 	int nfree = 0;
1183 	vmem_size_t total = 0;
1184 #if 1
1185 	vm_flag_t strat = VM_INSTANTFIT;
1186 #else
1187 	vm_flag_t strat = VM_BESTFIT;
1188 #endif
1189 
1190 	vm = vmem_create("test", VMEM_ADDR_NULL, 0, 1,
1191 	    NULL, NULL, NULL, 0, VM_NOSLEEP);
1192 	if (vm == NULL) {
1193 		printf("vmem_create\n");
1194 		exit(EXIT_FAILURE);
1195 	}
1196 	vmem_dump(vm);
1197 
1198 	p = vmem_add(vm, 100, 200, VM_SLEEP);
1199 	p = vmem_add(vm, 2000, 1, VM_SLEEP);
1200 	p = vmem_add(vm, 40000, 0x10000000>>12, VM_SLEEP);
1201 	p = vmem_add(vm, 10000, 10000, VM_SLEEP);
1202 	p = vmem_add(vm, 500, 1000, VM_SLEEP);
1203 	vmem_dump(vm);
1204 	for (;;) {
1205 		struct reg *r;
1206 		int t = rand() % 100;
1207 
1208 		if (t > 45) {
1209 			/* alloc */
1210 			vmem_size_t sz = rand() % 500 + 1;
1211 			boolean_t x;
1212 			vmem_size_t align, phase, nocross;
1213 			vmem_addr_t minaddr, maxaddr;
1214 
1215 			if (t > 70) {
1216 				x = TRUE;
1217 				/* XXX */
1218 				align = 1 << (rand() % 15);
1219 				phase = rand() % 65536;
1220 				nocross = 1 << (rand() % 15);
1221 				if (align <= phase) {
1222 					phase = 0;
1223 				}
1224 				if (VMEM_CROSS_P(phase, phase + sz - 1,
1225 				    nocross)) {
1226 					nocross = 0;
1227 				}
1228 				minaddr = rand() % 50000;
1229 				maxaddr = rand() % 70000;
1230 				if (minaddr > maxaddr) {
1231 					minaddr = 0;
1232 					maxaddr = 0;
1233 				}
1234 				printf("=== xalloc %" PRIu64
1235 				    " align=%" PRIu64 ", phase=%" PRIu64
1236 				    ", nocross=%" PRIu64 ", min=%" PRIu64
1237 				    ", max=%" PRIu64 "\n",
1238 				    (uint64_t)sz,
1239 				    (uint64_t)align,
1240 				    (uint64_t)phase,
1241 				    (uint64_t)nocross,
1242 				    (uint64_t)minaddr,
1243 				    (uint64_t)maxaddr);
1244 				p = vmem_xalloc(vm, sz, align, phase, nocross,
1245 				    minaddr, maxaddr, strat|VM_SLEEP);
1246 			} else {
1247 				x = FALSE;
1248 				printf("=== alloc %" PRIu64 "\n", (uint64_t)sz);
1249 				p = vmem_alloc(vm, sz, strat|VM_SLEEP);
1250 			}
1251 			printf("-> %" PRIu64 "\n", (uint64_t)p);
1252 			vmem_dump(vm);
1253 			if (p == VMEM_ADDR_NULL) {
1254 				if (x) {
1255 					continue;
1256 				}
1257 				break;
1258 			}
1259 			nreg++;
1260 			reg = realloc(reg, sizeof(*reg) * nreg);
1261 			r = &reg[nreg - 1];
1262 			r->p = p;
1263 			r->sz = sz;
1264 			r->x = x;
1265 			total += sz;
1266 			nalloc++;
1267 		} else if (nreg != 0) {
1268 			/* free */
1269 			r = &reg[rand() % nreg];
1270 			printf("=== free %" PRIu64 ", %" PRIu64 "\n",
1271 			    (uint64_t)r->p, (uint64_t)r->sz);
1272 			if (r->x) {
1273 				vmem_xfree(vm, r->p, r->sz);
1274 			} else {
1275 				vmem_free(vm, r->p, r->sz);
1276 			}
1277 			total -= r->sz;
1278 			vmem_dump(vm);
1279 			*r = reg[nreg - 1];
1280 			nreg--;
1281 			nfree++;
1282 		}
1283 		printf("total=%" PRIu64 "\n", (uint64_t)total);
1284 	}
1285 	fprintf(stderr, "total=%" PRIu64 ", nalloc=%d, nfree=%d\n",
1286 	    (uint64_t)total, nalloc, nfree);
1287 	exit(EXIT_SUCCESS);
1288 }
1289 #endif /* !defined(_KERNEL) */
1290 #endif /* defined(VMEM_DEBUG) */
1291