xref: /netbsd-src/sys/kern/subr_vmem.c (revision 48fb7bfab72acd4281a53bbee5ccf3f809019e75)
1 /*	$NetBSD: subr_vmem.c,v 1.88 2014/02/17 20:40:06 para 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 interferance 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 1.88 2014/02/17 20:40:06 para Exp $");
50 
51 #if defined(_KERNEL)
52 #include "opt_ddb.h"
53 #endif /* defined(_KERNEL) */
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	mutex_init(a, b, c)	/* nothing */
116 #define	mutex_destroy(a)	/* nothing */
117 #define	mutex_enter(a)		/* nothing */
118 #define	mutex_tryenter(a)	true
119 #define	mutex_exit(a)		/* nothing */
120 #define	mutex_owned(a)		/* nothing */
121 #define	ASSERT_SLEEPABLE()	/* nothing */
122 #define	panic(...)		printf(__VA_ARGS__); abort()
123 #endif /* defined(_KERNEL) */
124 
125 #if defined(VMEM_SANITY)
126 static void vmem_check(vmem_t *);
127 #else /* defined(VMEM_SANITY) */
128 #define vmem_check(vm)	/* nothing */
129 #endif /* defined(VMEM_SANITY) */
130 
131 #define	VMEM_HASHSIZE_MIN	1	/* XXX */
132 #define	VMEM_HASHSIZE_MAX	65536	/* XXX */
133 #define	VMEM_HASHSIZE_INIT	1
134 
135 #define	VM_FITMASK	(VM_BESTFIT | VM_INSTANTFIT)
136 
137 #if defined(_KERNEL)
138 static bool vmem_bootstrapped = false;
139 static kmutex_t vmem_list_lock;
140 static LIST_HEAD(, vmem) vmem_list = LIST_HEAD_INITIALIZER(vmem_list);
141 #endif /* defined(_KERNEL) */
142 
143 /* ---- misc */
144 
145 #define	VMEM_LOCK(vm)		mutex_enter(&vm->vm_lock)
146 #define	VMEM_TRYLOCK(vm)	mutex_tryenter(&vm->vm_lock)
147 #define	VMEM_UNLOCK(vm)		mutex_exit(&vm->vm_lock)
148 #define	VMEM_LOCK_INIT(vm, ipl)	mutex_init(&vm->vm_lock, MUTEX_DEFAULT, ipl)
149 #define	VMEM_LOCK_DESTROY(vm)	mutex_destroy(&vm->vm_lock)
150 #define	VMEM_ASSERT_LOCKED(vm)	KASSERT(mutex_owned(&vm->vm_lock))
151 
152 #define	VMEM_ALIGNUP(addr, align) \
153 	(-(-(addr) & -(align)))
154 
155 #define	VMEM_CROSS_P(addr1, addr2, boundary) \
156 	((((addr1) ^ (addr2)) & -(boundary)) != 0)
157 
158 #define	ORDER2SIZE(order)	((vmem_size_t)1 << (order))
159 #define	SIZE2ORDER(size)	((int)ilog2(size))
160 
161 #if !defined(_KERNEL)
162 #define	xmalloc(sz, flags)	malloc(sz)
163 #define	xfree(p, sz)		free(p)
164 #define	bt_alloc(vm, flags)	malloc(sizeof(bt_t))
165 #define	bt_free(vm, bt)		free(bt)
166 #else /* defined(_KERNEL) */
167 
168 #define	xmalloc(sz, flags) \
169     kmem_alloc(sz, ((flags) & VM_SLEEP) ? KM_SLEEP : KM_NOSLEEP);
170 #define	xfree(p, sz)		kmem_free(p, sz);
171 
172 /*
173  * BT_RESERVE calculation:
174  * we allocate memory for boundry tags with vmem, therefor we have
175  * to keep a reserve of bts used to allocated memory for bts.
176  * This reserve is 4 for each arena involved in allocating vmems memory.
177  * BT_MAXFREE: don't cache excessive counts of bts in arenas
178  */
179 #define STATIC_BT_COUNT 200
180 #define BT_MINRESERVE 4
181 #define BT_MAXFREE 64
182 
183 static struct vmem_btag static_bts[STATIC_BT_COUNT];
184 static int static_bt_count = STATIC_BT_COUNT;
185 
186 static struct vmem kmem_va_meta_arena_store;
187 vmem_t *kmem_va_meta_arena;
188 static struct vmem kmem_meta_arena_store;
189 vmem_t *kmem_meta_arena = NULL;
190 
191 static kmutex_t vmem_btag_refill_lock;
192 static kmutex_t vmem_btag_lock;
193 static LIST_HEAD(, vmem_btag) vmem_btag_freelist;
194 static size_t vmem_btag_freelist_count = 0;
195 static struct pool vmem_btag_pool;
196 
197 /* ---- boundary tag */
198 
199 static int bt_refill(vmem_t *vm, vm_flag_t flags);
200 
201 static void *
202 pool_page_alloc_vmem_meta(struct pool *pp, int flags)
203 {
204 	const vm_flag_t vflags = (flags & PR_WAITOK) ? VM_SLEEP: VM_NOSLEEP;
205 	vmem_addr_t va;
206 	int ret;
207 
208 	ret = vmem_alloc(kmem_meta_arena, pp->pr_alloc->pa_pagesz,
209 	    (vflags & ~VM_FITMASK) | VM_INSTANTFIT | VM_POPULATING, &va);
210 
211 	return ret ? NULL : (void *)va;
212 }
213 
214 static void
215 pool_page_free_vmem_meta(struct pool *pp, void *v)
216 {
217 
218 	vmem_free(kmem_meta_arena, (vmem_addr_t)v, pp->pr_alloc->pa_pagesz);
219 }
220 
221 /* allocator for vmem-pool metadata */
222 struct pool_allocator pool_allocator_vmem_meta = {
223 	.pa_alloc = pool_page_alloc_vmem_meta,
224 	.pa_free = pool_page_free_vmem_meta,
225 	.pa_pagesz = 0
226 };
227 
228 static int
229 bt_refill(vmem_t *vm, vm_flag_t flags)
230 {
231 	bt_t *bt;
232 
233 	VMEM_LOCK(vm);
234 	if (vm->vm_nfreetags > BT_MINRESERVE) {
235 		VMEM_UNLOCK(vm);
236 		return 0;
237 	}
238 
239 	mutex_enter(&vmem_btag_lock);
240 	while (!LIST_EMPTY(&vmem_btag_freelist) &&
241 	    vm->vm_nfreetags <= BT_MINRESERVE) {
242 		bt = LIST_FIRST(&vmem_btag_freelist);
243 		LIST_REMOVE(bt, bt_freelist);
244 		LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
245 		vm->vm_nfreetags++;
246 		vmem_btag_freelist_count--;
247 		VMEM_EVCNT_INCR(static_bt_inuse);
248 	}
249 	mutex_exit(&vmem_btag_lock);
250 
251 	while (vm->vm_nfreetags <= BT_MINRESERVE) {
252 		VMEM_UNLOCK(vm);
253 		mutex_enter(&vmem_btag_refill_lock);
254 		bt = pool_get(&vmem_btag_pool,
255 		    (flags & VM_SLEEP) ? PR_WAITOK: PR_NOWAIT);
256 		mutex_exit(&vmem_btag_refill_lock);
257 		VMEM_LOCK(vm);
258 		if (bt == NULL && (flags & VM_SLEEP) == 0)
259 			break;
260 		LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
261 		vm->vm_nfreetags++;
262 	}
263 
264 	VMEM_UNLOCK(vm);
265 
266 	if (vm->vm_nfreetags == 0) {
267 		return ENOMEM;
268 	}
269 
270 
271 	if (kmem_meta_arena != NULL) {
272 		bt_refill(kmem_arena, (flags & ~VM_FITMASK)
273 		    | VM_INSTANTFIT | VM_POPULATING);
274 		bt_refill(kmem_va_meta_arena, (flags & ~VM_FITMASK)
275 		    | VM_INSTANTFIT | VM_POPULATING);
276 		bt_refill(kmem_meta_arena, (flags & ~VM_FITMASK)
277 		    | VM_INSTANTFIT | VM_POPULATING);
278 	}
279 
280 	return 0;
281 }
282 
283 static bt_t *
284 bt_alloc(vmem_t *vm, vm_flag_t flags)
285 {
286 	bt_t *bt;
287 	VMEM_LOCK(vm);
288 	while (vm->vm_nfreetags <= BT_MINRESERVE && (flags & VM_POPULATING) == 0) {
289 		VMEM_UNLOCK(vm);
290 		if (bt_refill(vm, VM_NOSLEEP | VM_INSTANTFIT)) {
291 			return NULL;
292 		}
293 		VMEM_LOCK(vm);
294 	}
295 	bt = LIST_FIRST(&vm->vm_freetags);
296 	LIST_REMOVE(bt, bt_freelist);
297 	vm->vm_nfreetags--;
298 	VMEM_UNLOCK(vm);
299 
300 	return bt;
301 }
302 
303 static void
304 bt_free(vmem_t *vm, bt_t *bt)
305 {
306 
307 	VMEM_LOCK(vm);
308 	LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
309 	vm->vm_nfreetags++;
310 	VMEM_UNLOCK(vm);
311 }
312 
313 static void
314 bt_freetrim(vmem_t *vm, int freelimit)
315 {
316 	bt_t *t;
317 	LIST_HEAD(, vmem_btag) tofree;
318 
319 	LIST_INIT(&tofree);
320 
321 	VMEM_LOCK(vm);
322 	while (vm->vm_nfreetags > freelimit) {
323 		bt_t *bt = LIST_FIRST(&vm->vm_freetags);
324 		LIST_REMOVE(bt, bt_freelist);
325 		vm->vm_nfreetags--;
326 		if (bt >= static_bts
327 		    && bt < static_bts + sizeof(static_bts)) {
328 			mutex_enter(&vmem_btag_lock);
329 			LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
330 			vmem_btag_freelist_count++;
331 			mutex_exit(&vmem_btag_lock);
332 			VMEM_EVCNT_DECR(static_bt_inuse);
333 		} else {
334 			LIST_INSERT_HEAD(&tofree, bt, bt_freelist);
335 		}
336 	}
337 
338 	VMEM_UNLOCK(vm);
339 	while (!LIST_EMPTY(&tofree)) {
340 		t = LIST_FIRST(&tofree);
341 		LIST_REMOVE(t, bt_freelist);
342 		pool_put(&vmem_btag_pool, t);
343 	}
344 }
345 #endif	/* defined(_KERNEL) */
346 
347 /*
348  * freelist[0] ... [1, 1]
349  * freelist[1] ... [2, 3]
350  * freelist[2] ... [4, 7]
351  * freelist[3] ... [8, 15]
352  *  :
353  * freelist[n] ... [(1 << n), (1 << (n + 1)) - 1]
354  *  :
355  */
356 
357 static struct vmem_freelist *
358 bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
359 {
360 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
361 	const int idx = SIZE2ORDER(qsize);
362 
363 	KASSERT(size != 0 && qsize != 0);
364 	KASSERT((size & vm->vm_quantum_mask) == 0);
365 	KASSERT(idx >= 0);
366 	KASSERT(idx < VMEM_MAXORDER);
367 
368 	return &vm->vm_freelist[idx];
369 }
370 
371 /*
372  * bt_freehead_toalloc: return the freelist for the given size and allocation
373  * strategy.
374  *
375  * for VM_INSTANTFIT, return the list in which any blocks are large enough
376  * for the requested size.  otherwise, return the list which can have blocks
377  * large enough for the requested size.
378  */
379 
380 static struct vmem_freelist *
381 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, vm_flag_t strat)
382 {
383 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
384 	int idx = SIZE2ORDER(qsize);
385 
386 	KASSERT(size != 0 && qsize != 0);
387 	KASSERT((size & vm->vm_quantum_mask) == 0);
388 
389 	if (strat == VM_INSTANTFIT && ORDER2SIZE(idx) != qsize) {
390 		idx++;
391 		/* check too large request? */
392 	}
393 	KASSERT(idx >= 0);
394 	KASSERT(idx < VMEM_MAXORDER);
395 
396 	return &vm->vm_freelist[idx];
397 }
398 
399 /* ---- boundary tag hash */
400 
401 static struct vmem_hashlist *
402 bt_hashhead(vmem_t *vm, vmem_addr_t addr)
403 {
404 	struct vmem_hashlist *list;
405 	unsigned int hash;
406 
407 	hash = hash32_buf(&addr, sizeof(addr), HASH32_BUF_INIT);
408 	list = &vm->vm_hashlist[hash % vm->vm_hashsize];
409 
410 	return list;
411 }
412 
413 static bt_t *
414 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
415 {
416 	struct vmem_hashlist *list;
417 	bt_t *bt;
418 
419 	list = bt_hashhead(vm, addr);
420 	LIST_FOREACH(bt, list, bt_hashlist) {
421 		if (bt->bt_start == addr) {
422 			break;
423 		}
424 	}
425 
426 	return bt;
427 }
428 
429 static void
430 bt_rembusy(vmem_t *vm, bt_t *bt)
431 {
432 
433 	KASSERT(vm->vm_nbusytag > 0);
434 	vm->vm_inuse -= bt->bt_size;
435 	vm->vm_nbusytag--;
436 	LIST_REMOVE(bt, bt_hashlist);
437 }
438 
439 static void
440 bt_insbusy(vmem_t *vm, bt_t *bt)
441 {
442 	struct vmem_hashlist *list;
443 
444 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
445 
446 	list = bt_hashhead(vm, bt->bt_start);
447 	LIST_INSERT_HEAD(list, bt, bt_hashlist);
448 	vm->vm_nbusytag++;
449 	vm->vm_inuse += bt->bt_size;
450 }
451 
452 /* ---- boundary tag list */
453 
454 static void
455 bt_remseg(vmem_t *vm, bt_t *bt)
456 {
457 
458 	TAILQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
459 }
460 
461 static void
462 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
463 {
464 
465 	TAILQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
466 }
467 
468 static void
469 bt_insseg_tail(vmem_t *vm, bt_t *bt)
470 {
471 
472 	TAILQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
473 }
474 
475 static void
476 bt_remfree(vmem_t *vm, bt_t *bt)
477 {
478 
479 	KASSERT(bt->bt_type == BT_TYPE_FREE);
480 
481 	LIST_REMOVE(bt, bt_freelist);
482 }
483 
484 static void
485 bt_insfree(vmem_t *vm, bt_t *bt)
486 {
487 	struct vmem_freelist *list;
488 
489 	list = bt_freehead_tofree(vm, bt->bt_size);
490 	LIST_INSERT_HEAD(list, bt, bt_freelist);
491 }
492 
493 /* ---- vmem internal functions */
494 
495 #if defined(QCACHE)
496 static inline vm_flag_t
497 prf_to_vmf(int prflags)
498 {
499 	vm_flag_t vmflags;
500 
501 	KASSERT((prflags & ~(PR_LIMITFAIL | PR_WAITOK | PR_NOWAIT)) == 0);
502 	if ((prflags & PR_WAITOK) != 0) {
503 		vmflags = VM_SLEEP;
504 	} else {
505 		vmflags = VM_NOSLEEP;
506 	}
507 	return vmflags;
508 }
509 
510 static inline int
511 vmf_to_prf(vm_flag_t vmflags)
512 {
513 	int prflags;
514 
515 	if ((vmflags & VM_SLEEP) != 0) {
516 		prflags = PR_WAITOK;
517 	} else {
518 		prflags = PR_NOWAIT;
519 	}
520 	return prflags;
521 }
522 
523 static size_t
524 qc_poolpage_size(size_t qcache_max)
525 {
526 	int i;
527 
528 	for (i = 0; ORDER2SIZE(i) <= qcache_max * 3; i++) {
529 		/* nothing */
530 	}
531 	return ORDER2SIZE(i);
532 }
533 
534 static void *
535 qc_poolpage_alloc(struct pool *pool, int prflags)
536 {
537 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
538 	vmem_t *vm = qc->qc_vmem;
539 	vmem_addr_t addr;
540 
541 	if (vmem_alloc(vm, pool->pr_alloc->pa_pagesz,
542 	    prf_to_vmf(prflags) | VM_INSTANTFIT, &addr) != 0)
543 		return NULL;
544 	return (void *)addr;
545 }
546 
547 static void
548 qc_poolpage_free(struct pool *pool, void *addr)
549 {
550 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
551 	vmem_t *vm = qc->qc_vmem;
552 
553 	vmem_free(vm, (vmem_addr_t)addr, pool->pr_alloc->pa_pagesz);
554 }
555 
556 static void
557 qc_init(vmem_t *vm, size_t qcache_max, int ipl)
558 {
559 	qcache_t *prevqc;
560 	struct pool_allocator *pa;
561 	int qcache_idx_max;
562 	int i;
563 
564 	KASSERT((qcache_max & vm->vm_quantum_mask) == 0);
565 	if (qcache_max > (VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift)) {
566 		qcache_max = VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift;
567 	}
568 	vm->vm_qcache_max = qcache_max;
569 	pa = &vm->vm_qcache_allocator;
570 	memset(pa, 0, sizeof(*pa));
571 	pa->pa_alloc = qc_poolpage_alloc;
572 	pa->pa_free = qc_poolpage_free;
573 	pa->pa_pagesz = qc_poolpage_size(qcache_max);
574 
575 	qcache_idx_max = qcache_max >> vm->vm_quantum_shift;
576 	prevqc = NULL;
577 	for (i = qcache_idx_max; i > 0; i--) {
578 		qcache_t *qc = &vm->vm_qcache_store[i - 1];
579 		size_t size = i << vm->vm_quantum_shift;
580 		pool_cache_t pc;
581 
582 		qc->qc_vmem = vm;
583 		snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu",
584 		    vm->vm_name, size);
585 
586 		pc = pool_cache_init(size,
587 		    ORDER2SIZE(vm->vm_quantum_shift), 0,
588 		    PR_NOALIGN | PR_NOTOUCH | PR_RECURSIVE /* XXX */,
589 		    qc->qc_name, pa, ipl, NULL, NULL, NULL);
590 
591 		KASSERT(pc);
592 
593 		qc->qc_cache = pc;
594 		KASSERT(qc->qc_cache != NULL);	/* XXX */
595 		if (prevqc != NULL &&
596 		    qc->qc_cache->pc_pool.pr_itemsperpage ==
597 		    prevqc->qc_cache->pc_pool.pr_itemsperpage) {
598 			pool_cache_destroy(qc->qc_cache);
599 			vm->vm_qcache[i - 1] = prevqc;
600 			continue;
601 		}
602 		qc->qc_cache->pc_pool.pr_qcache = qc;
603 		vm->vm_qcache[i - 1] = qc;
604 		prevqc = qc;
605 	}
606 }
607 
608 static void
609 qc_destroy(vmem_t *vm)
610 {
611 	const qcache_t *prevqc;
612 	int i;
613 	int qcache_idx_max;
614 
615 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
616 	prevqc = NULL;
617 	for (i = 0; i < qcache_idx_max; i++) {
618 		qcache_t *qc = vm->vm_qcache[i];
619 
620 		if (prevqc == qc) {
621 			continue;
622 		}
623 		pool_cache_destroy(qc->qc_cache);
624 		prevqc = qc;
625 	}
626 }
627 #endif
628 
629 #if defined(_KERNEL)
630 static void
631 vmem_bootstrap(void)
632 {
633 
634 	mutex_init(&vmem_list_lock, MUTEX_DEFAULT, IPL_VM);
635 	mutex_init(&vmem_btag_lock, MUTEX_DEFAULT, IPL_VM);
636 	mutex_init(&vmem_btag_refill_lock, MUTEX_DEFAULT, IPL_VM);
637 
638 	while (static_bt_count-- > 0) {
639 		bt_t *bt = &static_bts[static_bt_count];
640 		LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
641 		VMEM_EVCNT_INCR(static_bt_count);
642 		vmem_btag_freelist_count++;
643 	}
644 	vmem_bootstrapped = TRUE;
645 }
646 
647 void
648 vmem_subsystem_init(vmem_t *vm)
649 {
650 
651 	kmem_va_meta_arena = vmem_init(&kmem_va_meta_arena_store, "vmem-va",
652 	    0, 0, PAGE_SIZE, vmem_alloc, vmem_free, vm,
653 	    0, VM_NOSLEEP | VM_BOOTSTRAP | VM_LARGEIMPORT,
654 	    IPL_VM);
655 
656 	kmem_meta_arena = vmem_init(&kmem_meta_arena_store, "vmem-meta",
657 	    0, 0, PAGE_SIZE,
658 	    uvm_km_kmem_alloc, uvm_km_kmem_free, kmem_va_meta_arena,
659 	    0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM);
660 
661 	pool_init(&vmem_btag_pool, sizeof(bt_t), 0, 0, PR_PHINPAGE,
662 		    "vmembt", &pool_allocator_vmem_meta, IPL_VM);
663 }
664 #endif /* defined(_KERNEL) */
665 
666 static int
667 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags,
668     int spanbttype)
669 {
670 	bt_t *btspan;
671 	bt_t *btfree;
672 
673 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
674 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
675 	KASSERT(spanbttype == BT_TYPE_SPAN ||
676 	    spanbttype == BT_TYPE_SPAN_STATIC);
677 
678 	btspan = bt_alloc(vm, flags);
679 	if (btspan == NULL) {
680 		return ENOMEM;
681 	}
682 	btfree = bt_alloc(vm, flags);
683 	if (btfree == NULL) {
684 		bt_free(vm, btspan);
685 		return ENOMEM;
686 	}
687 
688 	btspan->bt_type = spanbttype;
689 	btspan->bt_start = addr;
690 	btspan->bt_size = size;
691 
692 	btfree->bt_type = BT_TYPE_FREE;
693 	btfree->bt_start = addr;
694 	btfree->bt_size = size;
695 
696 	VMEM_LOCK(vm);
697 	bt_insseg_tail(vm, btspan);
698 	bt_insseg(vm, btfree, btspan);
699 	bt_insfree(vm, btfree);
700 	vm->vm_size += size;
701 	VMEM_UNLOCK(vm);
702 
703 	return 0;
704 }
705 
706 static void
707 vmem_destroy1(vmem_t *vm)
708 {
709 
710 #if defined(QCACHE)
711 	qc_destroy(vm);
712 #endif /* defined(QCACHE) */
713 	if (vm->vm_hashlist != NULL) {
714 		int i;
715 
716 		for (i = 0; i < vm->vm_hashsize; i++) {
717 			bt_t *bt;
718 
719 			while ((bt = LIST_FIRST(&vm->vm_hashlist[i])) != NULL) {
720 				KASSERT(bt->bt_type == BT_TYPE_SPAN_STATIC);
721 				bt_free(vm, bt);
722 			}
723 		}
724 		if (vm->vm_hashlist != &vm->vm_hash0) {
725 			xfree(vm->vm_hashlist,
726 			    sizeof(struct vmem_hashlist *) * vm->vm_hashsize);
727 		}
728 	}
729 
730 	bt_freetrim(vm, 0);
731 
732 	VMEM_CONDVAR_DESTROY(vm);
733 	VMEM_LOCK_DESTROY(vm);
734 	xfree(vm, sizeof(*vm));
735 }
736 
737 static int
738 vmem_import(vmem_t *vm, vmem_size_t size, vm_flag_t flags)
739 {
740 	vmem_addr_t addr;
741 	int rc;
742 
743 	if (vm->vm_importfn == NULL) {
744 		return EINVAL;
745 	}
746 
747 	if (vm->vm_flags & VM_LARGEIMPORT) {
748 		size *= 16;
749 	}
750 
751 	if (vm->vm_flags & VM_XIMPORT) {
752 		rc = ((vmem_ximport_t *)vm->vm_importfn)(vm->vm_arg, size,
753 		    &size, flags, &addr);
754 	} else {
755 		rc = (vm->vm_importfn)(vm->vm_arg, size, flags, &addr);
756 	}
757 	if (rc) {
758 		return ENOMEM;
759 	}
760 
761 	if (vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN) != 0) {
762 		(*vm->vm_releasefn)(vm->vm_arg, addr, size);
763 		return ENOMEM;
764 	}
765 
766 	return 0;
767 }
768 
769 static int
770 vmem_rehash(vmem_t *vm, size_t newhashsize, vm_flag_t flags)
771 {
772 	bt_t *bt;
773 	int i;
774 	struct vmem_hashlist *newhashlist;
775 	struct vmem_hashlist *oldhashlist;
776 	size_t oldhashsize;
777 
778 	KASSERT(newhashsize > 0);
779 
780 	newhashlist =
781 	    xmalloc(sizeof(struct vmem_hashlist *) * newhashsize, flags);
782 	if (newhashlist == NULL) {
783 		return ENOMEM;
784 	}
785 	for (i = 0; i < newhashsize; i++) {
786 		LIST_INIT(&newhashlist[i]);
787 	}
788 
789 	if (!VMEM_TRYLOCK(vm)) {
790 		xfree(newhashlist,
791 		    sizeof(struct vmem_hashlist *) * newhashsize);
792 		return EBUSY;
793 	}
794 	oldhashlist = vm->vm_hashlist;
795 	oldhashsize = vm->vm_hashsize;
796 	vm->vm_hashlist = newhashlist;
797 	vm->vm_hashsize = newhashsize;
798 	if (oldhashlist == NULL) {
799 		VMEM_UNLOCK(vm);
800 		return 0;
801 	}
802 	for (i = 0; i < oldhashsize; i++) {
803 		while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
804 			bt_rembusy(vm, bt); /* XXX */
805 			bt_insbusy(vm, bt);
806 		}
807 	}
808 	VMEM_UNLOCK(vm);
809 
810 	if (oldhashlist != &vm->vm_hash0) {
811 		xfree(oldhashlist,
812 		    sizeof(struct vmem_hashlist *) * oldhashsize);
813 	}
814 
815 	return 0;
816 }
817 
818 /*
819  * vmem_fit: check if a bt can satisfy the given restrictions.
820  *
821  * it's a caller's responsibility to ensure the region is big enough
822  * before calling us.
823  */
824 
825 static int
826 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align,
827     vmem_size_t phase, vmem_size_t nocross,
828     vmem_addr_t minaddr, vmem_addr_t maxaddr, vmem_addr_t *addrp)
829 {
830 	vmem_addr_t start;
831 	vmem_addr_t end;
832 
833 	KASSERT(size > 0);
834 	KASSERT(bt->bt_size >= size); /* caller's responsibility */
835 
836 	/*
837 	 * XXX assumption: vmem_addr_t and vmem_size_t are
838 	 * unsigned integer of the same size.
839 	 */
840 
841 	start = bt->bt_start;
842 	if (start < minaddr) {
843 		start = minaddr;
844 	}
845 	end = BT_END(bt);
846 	if (end > maxaddr) {
847 		end = maxaddr;
848 	}
849 	if (start > end) {
850 		return ENOMEM;
851 	}
852 
853 	start = VMEM_ALIGNUP(start - phase, align) + phase;
854 	if (start < bt->bt_start) {
855 		start += align;
856 	}
857 	if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
858 		KASSERT(align < nocross);
859 		start = VMEM_ALIGNUP(start - phase, nocross) + phase;
860 	}
861 	if (start <= end && end - start >= size - 1) {
862 		KASSERT((start & (align - 1)) == phase);
863 		KASSERT(!VMEM_CROSS_P(start, start + size - 1, nocross));
864 		KASSERT(minaddr <= start);
865 		KASSERT(maxaddr == 0 || start + size - 1 <= maxaddr);
866 		KASSERT(bt->bt_start <= start);
867 		KASSERT(BT_END(bt) - start >= size - 1);
868 		*addrp = start;
869 		return 0;
870 	}
871 	return ENOMEM;
872 }
873 
874 /* ---- vmem API */
875 
876 /*
877  * vmem_create_internal: creates a vmem arena.
878  */
879 
880 vmem_t *
881 vmem_init(vmem_t *vm, const char *name,
882     vmem_addr_t base, vmem_size_t size, vmem_size_t quantum,
883     vmem_import_t *importfn, vmem_release_t *releasefn,
884     vmem_t *arg, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
885 {
886 	int i;
887 
888 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
889 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
890 	KASSERT(quantum > 0);
891 
892 #if defined(_KERNEL)
893 	/* XXX: SMP, we get called early... */
894 	if (!vmem_bootstrapped) {
895 		vmem_bootstrap();
896 	}
897 #endif /* defined(_KERNEL) */
898 
899 	if (vm == NULL) {
900 		vm = xmalloc(sizeof(*vm), flags);
901 	}
902 	if (vm == NULL) {
903 		return NULL;
904 	}
905 
906 	VMEM_CONDVAR_INIT(vm, "vmem");
907 	VMEM_LOCK_INIT(vm, ipl);
908 	vm->vm_flags = flags;
909 	vm->vm_nfreetags = 0;
910 	LIST_INIT(&vm->vm_freetags);
911 	strlcpy(vm->vm_name, name, sizeof(vm->vm_name));
912 	vm->vm_quantum_mask = quantum - 1;
913 	vm->vm_quantum_shift = SIZE2ORDER(quantum);
914 	KASSERT(ORDER2SIZE(vm->vm_quantum_shift) == quantum);
915 	vm->vm_importfn = importfn;
916 	vm->vm_releasefn = releasefn;
917 	vm->vm_arg = arg;
918 	vm->vm_nbusytag = 0;
919 	vm->vm_size = 0;
920 	vm->vm_inuse = 0;
921 #if defined(QCACHE)
922 	qc_init(vm, qcache_max, ipl);
923 #endif /* defined(QCACHE) */
924 
925 	TAILQ_INIT(&vm->vm_seglist);
926 	for (i = 0; i < VMEM_MAXORDER; i++) {
927 		LIST_INIT(&vm->vm_freelist[i]);
928 	}
929 	memset(&vm->vm_hash0, 0, sizeof(struct vmem_hashlist));
930 	vm->vm_hashsize = 1;
931 	vm->vm_hashlist = &vm->vm_hash0;
932 
933 	if (size != 0) {
934 		if (vmem_add(vm, base, size, flags) != 0) {
935 			vmem_destroy1(vm);
936 			return NULL;
937 		}
938 	}
939 
940 #if defined(_KERNEL)
941 	if (flags & VM_BOOTSTRAP) {
942 		bt_refill(vm, VM_NOSLEEP);
943 	}
944 
945 	mutex_enter(&vmem_list_lock);
946 	LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist);
947 	mutex_exit(&vmem_list_lock);
948 #endif /* defined(_KERNEL) */
949 
950 	return vm;
951 }
952 
953 
954 
955 /*
956  * vmem_create: create an arena.
957  *
958  * => must not be called from interrupt context.
959  */
960 
961 vmem_t *
962 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
963     vmem_size_t quantum, vmem_import_t *importfn, vmem_release_t *releasefn,
964     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
965 {
966 
967 	KASSERT((flags & (VM_XIMPORT)) == 0);
968 
969 	return vmem_init(NULL, name, base, size, quantum,
970 	    importfn, releasefn, source, qcache_max, flags, ipl);
971 }
972 
973 /*
974  * vmem_xcreate: create an arena takes alternative import func.
975  *
976  * => must not be called from interrupt context.
977  */
978 
979 vmem_t *
980 vmem_xcreate(const char *name, vmem_addr_t base, vmem_size_t size,
981     vmem_size_t quantum, vmem_ximport_t *importfn, vmem_release_t *releasefn,
982     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
983 {
984 
985 	KASSERT((flags & (VM_XIMPORT)) == 0);
986 
987 	return vmem_init(NULL, name, base, size, quantum,
988 	    (vmem_import_t *)importfn, releasefn, source,
989 	    qcache_max, flags | VM_XIMPORT, ipl);
990 }
991 
992 void
993 vmem_destroy(vmem_t *vm)
994 {
995 
996 #if defined(_KERNEL)
997 	mutex_enter(&vmem_list_lock);
998 	LIST_REMOVE(vm, vm_alllist);
999 	mutex_exit(&vmem_list_lock);
1000 #endif /* defined(_KERNEL) */
1001 
1002 	vmem_destroy1(vm);
1003 }
1004 
1005 vmem_size_t
1006 vmem_roundup_size(vmem_t *vm, vmem_size_t size)
1007 {
1008 
1009 	return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
1010 }
1011 
1012 /*
1013  * vmem_alloc: allocate resource from the arena.
1014  */
1015 
1016 int
1017 vmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, vmem_addr_t *addrp)
1018 {
1019 	const vm_flag_t strat __diagused = flags & VM_FITMASK;
1020 
1021 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
1022 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
1023 
1024 	KASSERT(size > 0);
1025 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
1026 	if ((flags & VM_SLEEP) != 0) {
1027 		ASSERT_SLEEPABLE();
1028 	}
1029 
1030 #if defined(QCACHE)
1031 	if (size <= vm->vm_qcache_max) {
1032 		void *p;
1033 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1034 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1035 
1036 		p = pool_cache_get(qc->qc_cache, vmf_to_prf(flags));
1037 		if (addrp != NULL)
1038 			*addrp = (vmem_addr_t)p;
1039 		return (p == NULL) ? ENOMEM : 0;
1040 	}
1041 #endif /* defined(QCACHE) */
1042 
1043 	return vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
1044 	    flags, addrp);
1045 }
1046 
1047 int
1048 vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align,
1049     const vmem_size_t phase, const vmem_size_t nocross,
1050     const vmem_addr_t minaddr, const vmem_addr_t maxaddr, const vm_flag_t flags,
1051     vmem_addr_t *addrp)
1052 {
1053 	struct vmem_freelist *list;
1054 	struct vmem_freelist *first;
1055 	struct vmem_freelist *end;
1056 	bt_t *bt;
1057 	bt_t *btnew;
1058 	bt_t *btnew2;
1059 	const vmem_size_t size = vmem_roundup_size(vm, size0);
1060 	vm_flag_t strat = flags & VM_FITMASK;
1061 	vmem_addr_t start;
1062 	int rc;
1063 
1064 	KASSERT(size0 > 0);
1065 	KASSERT(size > 0);
1066 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
1067 	if ((flags & VM_SLEEP) != 0) {
1068 		ASSERT_SLEEPABLE();
1069 	}
1070 	KASSERT((align & vm->vm_quantum_mask) == 0);
1071 	KASSERT((align & (align - 1)) == 0);
1072 	KASSERT((phase & vm->vm_quantum_mask) == 0);
1073 	KASSERT((nocross & vm->vm_quantum_mask) == 0);
1074 	KASSERT((nocross & (nocross - 1)) == 0);
1075 	KASSERT((align == 0 && phase == 0) || phase < align);
1076 	KASSERT(nocross == 0 || nocross >= size);
1077 	KASSERT(minaddr <= maxaddr);
1078 	KASSERT(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
1079 
1080 	if (align == 0) {
1081 		align = vm->vm_quantum_mask + 1;
1082 	}
1083 
1084 	/*
1085 	 * allocate boundary tags before acquiring the vmem lock.
1086 	 */
1087 	btnew = bt_alloc(vm, flags);
1088 	if (btnew == NULL) {
1089 		return ENOMEM;
1090 	}
1091 	btnew2 = bt_alloc(vm, flags); /* XXX not necessary if no restrictions */
1092 	if (btnew2 == NULL) {
1093 		bt_free(vm, btnew);
1094 		return ENOMEM;
1095 	}
1096 
1097 	/*
1098 	 * choose a free block from which we allocate.
1099 	 */
1100 retry_strat:
1101 	first = bt_freehead_toalloc(vm, size, strat);
1102 	end = &vm->vm_freelist[VMEM_MAXORDER];
1103 retry:
1104 	bt = NULL;
1105 	VMEM_LOCK(vm);
1106 	vmem_check(vm);
1107 	if (strat == VM_INSTANTFIT) {
1108 		/*
1109 		 * just choose the first block which satisfies our restrictions.
1110 		 *
1111 		 * note that we don't need to check the size of the blocks
1112 		 * because any blocks found on these list should be larger than
1113 		 * the given size.
1114 		 */
1115 		for (list = first; list < end; list++) {
1116 			bt = LIST_FIRST(list);
1117 			if (bt != NULL) {
1118 				rc = vmem_fit(bt, size, align, phase,
1119 				    nocross, minaddr, maxaddr, &start);
1120 				if (rc == 0) {
1121 					goto gotit;
1122 				}
1123 				/*
1124 				 * don't bother to follow the bt_freelist link
1125 				 * here.  the list can be very long and we are
1126 				 * told to run fast.  blocks from the later free
1127 				 * lists are larger and have better chances to
1128 				 * satisfy our restrictions.
1129 				 */
1130 			}
1131 		}
1132 	} else { /* VM_BESTFIT */
1133 		/*
1134 		 * we assume that, for space efficiency, it's better to
1135 		 * allocate from a smaller block.  thus we will start searching
1136 		 * from the lower-order list than VM_INSTANTFIT.
1137 		 * however, don't bother to find the smallest block in a free
1138 		 * list because the list can be very long.  we can revisit it
1139 		 * if/when it turns out to be a problem.
1140 		 *
1141 		 * note that the 'first' list can contain blocks smaller than
1142 		 * the requested size.  thus we need to check bt_size.
1143 		 */
1144 		for (list = first; list < end; list++) {
1145 			LIST_FOREACH(bt, list, bt_freelist) {
1146 				if (bt->bt_size >= size) {
1147 					rc = vmem_fit(bt, size, align, phase,
1148 					    nocross, minaddr, maxaddr, &start);
1149 					if (rc == 0) {
1150 						goto gotit;
1151 					}
1152 				}
1153 			}
1154 		}
1155 	}
1156 	VMEM_UNLOCK(vm);
1157 #if 1
1158 	if (strat == VM_INSTANTFIT) {
1159 		strat = VM_BESTFIT;
1160 		goto retry_strat;
1161 	}
1162 #endif
1163 	if (align != vm->vm_quantum_mask + 1 || phase != 0 || nocross != 0) {
1164 
1165 		/*
1166 		 * XXX should try to import a region large enough to
1167 		 * satisfy restrictions?
1168 		 */
1169 
1170 		goto fail;
1171 	}
1172 	/* XXX eeek, minaddr & maxaddr not respected */
1173 	if (vmem_import(vm, size, flags) == 0) {
1174 		goto retry;
1175 	}
1176 	/* XXX */
1177 
1178 	if ((flags & VM_SLEEP) != 0) {
1179 #if defined(_KERNEL) && !defined(_RUMPKERNEL)
1180 		mutex_spin_enter(&uvm_fpageqlock);
1181 		uvm_kick_pdaemon();
1182 		mutex_spin_exit(&uvm_fpageqlock);
1183 #endif
1184 		VMEM_LOCK(vm);
1185 		VMEM_CONDVAR_WAIT(vm);
1186 		VMEM_UNLOCK(vm);
1187 		goto retry;
1188 	}
1189 fail:
1190 	bt_free(vm, btnew);
1191 	bt_free(vm, btnew2);
1192 	return ENOMEM;
1193 
1194 gotit:
1195 	KASSERT(bt->bt_type == BT_TYPE_FREE);
1196 	KASSERT(bt->bt_size >= size);
1197 	bt_remfree(vm, bt);
1198 	vmem_check(vm);
1199 	if (bt->bt_start != start) {
1200 		btnew2->bt_type = BT_TYPE_FREE;
1201 		btnew2->bt_start = bt->bt_start;
1202 		btnew2->bt_size = start - bt->bt_start;
1203 		bt->bt_start = start;
1204 		bt->bt_size -= btnew2->bt_size;
1205 		bt_insfree(vm, btnew2);
1206 		bt_insseg(vm, btnew2, TAILQ_PREV(bt, vmem_seglist, bt_seglist));
1207 		btnew2 = NULL;
1208 		vmem_check(vm);
1209 	}
1210 	KASSERT(bt->bt_start == start);
1211 	if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
1212 		/* split */
1213 		btnew->bt_type = BT_TYPE_BUSY;
1214 		btnew->bt_start = bt->bt_start;
1215 		btnew->bt_size = size;
1216 		bt->bt_start = bt->bt_start + size;
1217 		bt->bt_size -= size;
1218 		bt_insfree(vm, bt);
1219 		bt_insseg(vm, btnew, TAILQ_PREV(bt, vmem_seglist, bt_seglist));
1220 		bt_insbusy(vm, btnew);
1221 		vmem_check(vm);
1222 		VMEM_UNLOCK(vm);
1223 	} else {
1224 		bt->bt_type = BT_TYPE_BUSY;
1225 		bt_insbusy(vm, bt);
1226 		vmem_check(vm);
1227 		VMEM_UNLOCK(vm);
1228 		bt_free(vm, btnew);
1229 		btnew = bt;
1230 	}
1231 	if (btnew2 != NULL) {
1232 		bt_free(vm, btnew2);
1233 	}
1234 	KASSERT(btnew->bt_size >= size);
1235 	btnew->bt_type = BT_TYPE_BUSY;
1236 
1237 	if (addrp != NULL)
1238 		*addrp = btnew->bt_start;
1239 	return 0;
1240 }
1241 
1242 /*
1243  * vmem_free: free the resource to the arena.
1244  */
1245 
1246 void
1247 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1248 {
1249 
1250 	KASSERT(size > 0);
1251 
1252 #if defined(QCACHE)
1253 	if (size <= vm->vm_qcache_max) {
1254 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1255 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1256 
1257 		pool_cache_put(qc->qc_cache, (void *)addr);
1258 		return;
1259 	}
1260 #endif /* defined(QCACHE) */
1261 
1262 	vmem_xfree(vm, addr, size);
1263 }
1264 
1265 void
1266 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1267 {
1268 	bt_t *bt;
1269 	bt_t *t;
1270 	LIST_HEAD(, vmem_btag) tofree;
1271 
1272 	LIST_INIT(&tofree);
1273 
1274 	KASSERT(size > 0);
1275 
1276 	VMEM_LOCK(vm);
1277 
1278 	bt = bt_lookupbusy(vm, addr);
1279 	KASSERT(bt != NULL);
1280 	KASSERT(bt->bt_start == addr);
1281 	KASSERT(bt->bt_size == vmem_roundup_size(vm, size) ||
1282 	    bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
1283 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
1284 	bt_rembusy(vm, bt);
1285 	bt->bt_type = BT_TYPE_FREE;
1286 
1287 	/* coalesce */
1288 	t = TAILQ_NEXT(bt, bt_seglist);
1289 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1290 		KASSERT(BT_END(bt) < t->bt_start);	/* YYY */
1291 		bt_remfree(vm, t);
1292 		bt_remseg(vm, t);
1293 		bt->bt_size += t->bt_size;
1294 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1295 	}
1296 	t = TAILQ_PREV(bt, vmem_seglist, bt_seglist);
1297 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1298 		KASSERT(BT_END(t) < bt->bt_start);	/* YYY */
1299 		bt_remfree(vm, t);
1300 		bt_remseg(vm, t);
1301 		bt->bt_size += t->bt_size;
1302 		bt->bt_start = t->bt_start;
1303 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1304 	}
1305 
1306 	t = TAILQ_PREV(bt, vmem_seglist, bt_seglist);
1307 	KASSERT(t != NULL);
1308 	KASSERT(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY);
1309 	if (vm->vm_releasefn != NULL && t->bt_type == BT_TYPE_SPAN &&
1310 	    t->bt_size == bt->bt_size) {
1311 		vmem_addr_t spanaddr;
1312 		vmem_size_t spansize;
1313 
1314 		KASSERT(t->bt_start == bt->bt_start);
1315 		spanaddr = bt->bt_start;
1316 		spansize = bt->bt_size;
1317 		bt_remseg(vm, bt);
1318 		LIST_INSERT_HEAD(&tofree, bt, bt_freelist);
1319 		bt_remseg(vm, t);
1320 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1321 		vm->vm_size -= spansize;
1322 		VMEM_CONDVAR_BROADCAST(vm);
1323 		VMEM_UNLOCK(vm);
1324 		(*vm->vm_releasefn)(vm->vm_arg, spanaddr, spansize);
1325 	} else {
1326 		bt_insfree(vm, bt);
1327 		VMEM_CONDVAR_BROADCAST(vm);
1328 		VMEM_UNLOCK(vm);
1329 	}
1330 
1331 	while (!LIST_EMPTY(&tofree)) {
1332 		t = LIST_FIRST(&tofree);
1333 		LIST_REMOVE(t, bt_freelist);
1334 		bt_free(vm, t);
1335 	}
1336 
1337 	bt_freetrim(vm, BT_MAXFREE);
1338 }
1339 
1340 /*
1341  * vmem_add:
1342  *
1343  * => caller must ensure appropriate spl,
1344  *    if the arena can be accessed from interrupt context.
1345  */
1346 
1347 int
1348 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags)
1349 {
1350 
1351 	return vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN_STATIC);
1352 }
1353 
1354 /*
1355  * vmem_size: information about arenas size
1356  *
1357  * => return free/allocated size in arena
1358  */
1359 vmem_size_t
1360 vmem_size(vmem_t *vm, int typemask)
1361 {
1362 
1363 	switch (typemask) {
1364 	case VMEM_ALLOC:
1365 		return vm->vm_inuse;
1366 	case VMEM_FREE:
1367 		return vm->vm_size - vm->vm_inuse;
1368 	case VMEM_FREE|VMEM_ALLOC:
1369 		return vm->vm_size;
1370 	default:
1371 		panic("vmem_size");
1372 	}
1373 }
1374 
1375 /* ---- rehash */
1376 
1377 #if defined(_KERNEL)
1378 static struct callout vmem_rehash_ch;
1379 static int vmem_rehash_interval;
1380 static struct workqueue *vmem_rehash_wq;
1381 static struct work vmem_rehash_wk;
1382 
1383 static void
1384 vmem_rehash_all(struct work *wk, void *dummy)
1385 {
1386 	vmem_t *vm;
1387 
1388 	KASSERT(wk == &vmem_rehash_wk);
1389 	mutex_enter(&vmem_list_lock);
1390 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1391 		size_t desired;
1392 		size_t current;
1393 
1394 		if (!VMEM_TRYLOCK(vm)) {
1395 			continue;
1396 		}
1397 		desired = vm->vm_nbusytag;
1398 		current = vm->vm_hashsize;
1399 		VMEM_UNLOCK(vm);
1400 
1401 		if (desired > VMEM_HASHSIZE_MAX) {
1402 			desired = VMEM_HASHSIZE_MAX;
1403 		} else if (desired < VMEM_HASHSIZE_MIN) {
1404 			desired = VMEM_HASHSIZE_MIN;
1405 		}
1406 		if (desired > current * 2 || desired * 2 < current) {
1407 			vmem_rehash(vm, desired, VM_NOSLEEP);
1408 		}
1409 	}
1410 	mutex_exit(&vmem_list_lock);
1411 
1412 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1413 }
1414 
1415 static void
1416 vmem_rehash_all_kick(void *dummy)
1417 {
1418 
1419 	workqueue_enqueue(vmem_rehash_wq, &vmem_rehash_wk, NULL);
1420 }
1421 
1422 void
1423 vmem_rehash_start(void)
1424 {
1425 	int error;
1426 
1427 	error = workqueue_create(&vmem_rehash_wq, "vmem_rehash",
1428 	    vmem_rehash_all, NULL, PRI_VM, IPL_SOFTCLOCK, WQ_MPSAFE);
1429 	if (error) {
1430 		panic("%s: workqueue_create %d\n", __func__, error);
1431 	}
1432 	callout_init(&vmem_rehash_ch, CALLOUT_MPSAFE);
1433 	callout_setfunc(&vmem_rehash_ch, vmem_rehash_all_kick, NULL);
1434 
1435 	vmem_rehash_interval = hz * 10;
1436 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1437 }
1438 #endif /* defined(_KERNEL) */
1439 
1440 /* ---- debug */
1441 
1442 #if defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY)
1443 
1444 static void bt_dump(const bt_t *, void (*)(const char *, ...)
1445     __printflike(1, 2));
1446 
1447 static const char *
1448 bt_type_string(int type)
1449 {
1450 	static const char * const table[] = {
1451 		[BT_TYPE_BUSY] = "busy",
1452 		[BT_TYPE_FREE] = "free",
1453 		[BT_TYPE_SPAN] = "span",
1454 		[BT_TYPE_SPAN_STATIC] = "static span",
1455 	};
1456 
1457 	if (type >= __arraycount(table)) {
1458 		return "BOGUS";
1459 	}
1460 	return table[type];
1461 }
1462 
1463 static void
1464 bt_dump(const bt_t *bt, void (*pr)(const char *, ...))
1465 {
1466 
1467 	(*pr)("\t%p: %" PRIu64 ", %" PRIu64 ", %d(%s)\n",
1468 	    bt, (uint64_t)bt->bt_start, (uint64_t)bt->bt_size,
1469 	    bt->bt_type, bt_type_string(bt->bt_type));
1470 }
1471 
1472 static void
1473 vmem_dump(const vmem_t *vm , void (*pr)(const char *, ...) __printflike(1, 2))
1474 {
1475 	const bt_t *bt;
1476 	int i;
1477 
1478 	(*pr)("vmem %p '%s'\n", vm, vm->vm_name);
1479 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1480 		bt_dump(bt, pr);
1481 	}
1482 
1483 	for (i = 0; i < VMEM_MAXORDER; i++) {
1484 		const struct vmem_freelist *fl = &vm->vm_freelist[i];
1485 
1486 		if (LIST_EMPTY(fl)) {
1487 			continue;
1488 		}
1489 
1490 		(*pr)("freelist[%d]\n", i);
1491 		LIST_FOREACH(bt, fl, bt_freelist) {
1492 			bt_dump(bt, pr);
1493 		}
1494 	}
1495 }
1496 
1497 #endif /* defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY) */
1498 
1499 #if defined(DDB)
1500 static bt_t *
1501 vmem_whatis_lookup(vmem_t *vm, uintptr_t addr)
1502 {
1503 	bt_t *bt;
1504 
1505 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1506 		if (BT_ISSPAN_P(bt)) {
1507 			continue;
1508 		}
1509 		if (bt->bt_start <= addr && addr <= BT_END(bt)) {
1510 			return bt;
1511 		}
1512 	}
1513 
1514 	return NULL;
1515 }
1516 
1517 void
1518 vmem_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1519 {
1520 	vmem_t *vm;
1521 
1522 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1523 		bt_t *bt;
1524 
1525 		bt = vmem_whatis_lookup(vm, addr);
1526 		if (bt == NULL) {
1527 			continue;
1528 		}
1529 		(*pr)("%p is %p+%zu in VMEM '%s' (%s)\n",
1530 		    (void *)addr, (void *)bt->bt_start,
1531 		    (size_t)(addr - bt->bt_start), vm->vm_name,
1532 		    (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free");
1533 	}
1534 }
1535 
1536 void
1537 vmem_printall(const char *modif, void (*pr)(const char *, ...))
1538 {
1539 	const vmem_t *vm;
1540 
1541 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1542 		vmem_dump(vm, pr);
1543 	}
1544 }
1545 
1546 void
1547 vmem_print(uintptr_t addr, const char *modif, void (*pr)(const char *, ...))
1548 {
1549 	const vmem_t *vm = (const void *)addr;
1550 
1551 	vmem_dump(vm, pr);
1552 }
1553 #endif /* defined(DDB) */
1554 
1555 #if defined(_KERNEL)
1556 #define vmem_printf printf
1557 #else
1558 #include <stdio.h>
1559 #include <stdarg.h>
1560 
1561 static void
1562 vmem_printf(const char *fmt, ...)
1563 {
1564 	va_list ap;
1565 	va_start(ap, fmt);
1566 	vprintf(fmt, ap);
1567 	va_end(ap);
1568 }
1569 #endif
1570 
1571 #if defined(VMEM_SANITY)
1572 
1573 static bool
1574 vmem_check_sanity(vmem_t *vm)
1575 {
1576 	const bt_t *bt, *bt2;
1577 
1578 	KASSERT(vm != NULL);
1579 
1580 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1581 		if (bt->bt_start > BT_END(bt)) {
1582 			printf("corrupted tag\n");
1583 			bt_dump(bt, vmem_printf);
1584 			return false;
1585 		}
1586 	}
1587 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1588 		TAILQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) {
1589 			if (bt == bt2) {
1590 				continue;
1591 			}
1592 			if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) {
1593 				continue;
1594 			}
1595 			if (bt->bt_start <= BT_END(bt2) &&
1596 			    bt2->bt_start <= BT_END(bt)) {
1597 				printf("overwrapped tags\n");
1598 				bt_dump(bt, vmem_printf);
1599 				bt_dump(bt2, vmem_printf);
1600 				return false;
1601 			}
1602 		}
1603 	}
1604 
1605 	return true;
1606 }
1607 
1608 static void
1609 vmem_check(vmem_t *vm)
1610 {
1611 
1612 	if (!vmem_check_sanity(vm)) {
1613 		panic("insanity vmem %p", vm);
1614 	}
1615 }
1616 
1617 #endif /* defined(VMEM_SANITY) */
1618 
1619 #if defined(UNITTEST)
1620 int
1621 main(void)
1622 {
1623 	int rc;
1624 	vmem_t *vm;
1625 	vmem_addr_t p;
1626 	struct reg {
1627 		vmem_addr_t p;
1628 		vmem_size_t sz;
1629 		bool x;
1630 	} *reg = NULL;
1631 	int nreg = 0;
1632 	int nalloc = 0;
1633 	int nfree = 0;
1634 	vmem_size_t total = 0;
1635 #if 1
1636 	vm_flag_t strat = VM_INSTANTFIT;
1637 #else
1638 	vm_flag_t strat = VM_BESTFIT;
1639 #endif
1640 
1641 	vm = vmem_create("test", 0, 0, 1, NULL, NULL, NULL, 0, VM_SLEEP,
1642 #ifdef _KERNEL
1643 	    IPL_NONE
1644 #else
1645 	    0
1646 #endif
1647 	    );
1648 	if (vm == NULL) {
1649 		printf("vmem_create\n");
1650 		exit(EXIT_FAILURE);
1651 	}
1652 	vmem_dump(vm, vmem_printf);
1653 
1654 	rc = vmem_add(vm, 0, 50, VM_SLEEP);
1655 	assert(rc == 0);
1656 	rc = vmem_add(vm, 100, 200, VM_SLEEP);
1657 	assert(rc == 0);
1658 	rc = vmem_add(vm, 2000, 1, VM_SLEEP);
1659 	assert(rc == 0);
1660 	rc = vmem_add(vm, 40000, 65536, VM_SLEEP);
1661 	assert(rc == 0);
1662 	rc = vmem_add(vm, 10000, 10000, VM_SLEEP);
1663 	assert(rc == 0);
1664 	rc = vmem_add(vm, 500, 1000, VM_SLEEP);
1665 	assert(rc == 0);
1666 	rc = vmem_add(vm, 0xffffff00, 0x100, VM_SLEEP);
1667 	assert(rc == 0);
1668 	rc = vmem_xalloc(vm, 0x101, 0, 0, 0,
1669 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1670 	assert(rc != 0);
1671 	rc = vmem_xalloc(vm, 50, 0, 0, 0, 0, 49, strat|VM_SLEEP, &p);
1672 	assert(rc == 0 && p == 0);
1673 	vmem_xfree(vm, p, 50);
1674 	rc = vmem_xalloc(vm, 25, 0, 0, 0, 0, 24, strat|VM_SLEEP, &p);
1675 	assert(rc == 0 && p == 0);
1676 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1677 	    0xffffff01, 0xffffffff, strat|VM_SLEEP, &p);
1678 	assert(rc != 0);
1679 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1680 	    0xffffff00, 0xfffffffe, strat|VM_SLEEP, &p);
1681 	assert(rc != 0);
1682 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1683 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1684 	assert(rc == 0);
1685 	vmem_dump(vm, vmem_printf);
1686 	for (;;) {
1687 		struct reg *r;
1688 		int t = rand() % 100;
1689 
1690 		if (t > 45) {
1691 			/* alloc */
1692 			vmem_size_t sz = rand() % 500 + 1;
1693 			bool x;
1694 			vmem_size_t align, phase, nocross;
1695 			vmem_addr_t minaddr, maxaddr;
1696 
1697 			if (t > 70) {
1698 				x = true;
1699 				/* XXX */
1700 				align = 1 << (rand() % 15);
1701 				phase = rand() % 65536;
1702 				nocross = 1 << (rand() % 15);
1703 				if (align <= phase) {
1704 					phase = 0;
1705 				}
1706 				if (VMEM_CROSS_P(phase, phase + sz - 1,
1707 				    nocross)) {
1708 					nocross = 0;
1709 				}
1710 				do {
1711 					minaddr = rand() % 50000;
1712 					maxaddr = rand() % 70000;
1713 				} while (minaddr > maxaddr);
1714 				printf("=== xalloc %" PRIu64
1715 				    " align=%" PRIu64 ", phase=%" PRIu64
1716 				    ", nocross=%" PRIu64 ", min=%" PRIu64
1717 				    ", max=%" PRIu64 "\n",
1718 				    (uint64_t)sz,
1719 				    (uint64_t)align,
1720 				    (uint64_t)phase,
1721 				    (uint64_t)nocross,
1722 				    (uint64_t)minaddr,
1723 				    (uint64_t)maxaddr);
1724 				rc = vmem_xalloc(vm, sz, align, phase, nocross,
1725 				    minaddr, maxaddr, strat|VM_SLEEP, &p);
1726 			} else {
1727 				x = false;
1728 				printf("=== alloc %" PRIu64 "\n", (uint64_t)sz);
1729 				rc = vmem_alloc(vm, sz, strat|VM_SLEEP, &p);
1730 			}
1731 			printf("-> %" PRIu64 "\n", (uint64_t)p);
1732 			vmem_dump(vm, vmem_printf);
1733 			if (rc != 0) {
1734 				if (x) {
1735 					continue;
1736 				}
1737 				break;
1738 			}
1739 			nreg++;
1740 			reg = realloc(reg, sizeof(*reg) * nreg);
1741 			r = &reg[nreg - 1];
1742 			r->p = p;
1743 			r->sz = sz;
1744 			r->x = x;
1745 			total += sz;
1746 			nalloc++;
1747 		} else if (nreg != 0) {
1748 			/* free */
1749 			r = &reg[rand() % nreg];
1750 			printf("=== free %" PRIu64 ", %" PRIu64 "\n",
1751 			    (uint64_t)r->p, (uint64_t)r->sz);
1752 			if (r->x) {
1753 				vmem_xfree(vm, r->p, r->sz);
1754 			} else {
1755 				vmem_free(vm, r->p, r->sz);
1756 			}
1757 			total -= r->sz;
1758 			vmem_dump(vm, vmem_printf);
1759 			*r = reg[nreg - 1];
1760 			nreg--;
1761 			nfree++;
1762 		}
1763 		printf("total=%" PRIu64 "\n", (uint64_t)total);
1764 	}
1765 	fprintf(stderr, "total=%" PRIu64 ", nalloc=%d, nfree=%d\n",
1766 	    (uint64_t)total, nalloc, nfree);
1767 	exit(EXIT_SUCCESS);
1768 }
1769 #endif /* defined(UNITTEST) */
1770