xref: /netbsd-src/sys/kern/subr_vmem.c (revision 6cf6fe02a981b55727c49c3d37b0d8191a98c0ee)
1 /*	$NetBSD: subr_vmem.c,v 1.92 2014/04/02 18:09:10 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 1.92 2014/04/02 18:09:10 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 	KASSERT(flags & VM_NOSLEEP);
234 
235 	VMEM_LOCK(vm);
236 	if (vm->vm_nfreetags > BT_MINRESERVE) {
237 		VMEM_UNLOCK(vm);
238 		return 0;
239 	}
240 
241 	mutex_enter(&vmem_btag_lock);
242 	while (!LIST_EMPTY(&vmem_btag_freelist) &&
243 	    vm->vm_nfreetags <= BT_MINRESERVE) {
244 		bt = LIST_FIRST(&vmem_btag_freelist);
245 		LIST_REMOVE(bt, bt_freelist);
246 		LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
247 		vm->vm_nfreetags++;
248 		vmem_btag_freelist_count--;
249 		VMEM_EVCNT_INCR(static_bt_inuse);
250 	}
251 	mutex_exit(&vmem_btag_lock);
252 
253 	while (vm->vm_nfreetags <= BT_MINRESERVE) {
254 		VMEM_UNLOCK(vm);
255 		mutex_enter(&vmem_btag_refill_lock);
256 		bt = pool_get(&vmem_btag_pool, PR_NOWAIT);
257 		mutex_exit(&vmem_btag_refill_lock);
258 		VMEM_LOCK(vm);
259 		if (bt == NULL)
260 			break;
261 		LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
262 		vm->vm_nfreetags++;
263 	}
264 
265 	if (vm->vm_nfreetags <= BT_MINRESERVE) {
266 		VMEM_UNLOCK(vm);
267 		return ENOMEM;
268 	}
269 
270 	VMEM_UNLOCK(vm);
271 
272 	if (kmem_meta_arena != NULL) {
273 		bt_refill(kmem_arena, (flags & ~VM_FITMASK)
274 		    | VM_INSTANTFIT | VM_POPULATING);
275 		bt_refill(kmem_va_meta_arena, (flags & ~VM_FITMASK)
276 		    | VM_INSTANTFIT | VM_POPULATING);
277 		bt_refill(kmem_meta_arena, (flags & ~VM_FITMASK)
278 		    | VM_INSTANTFIT | VM_POPULATING);
279 	}
280 
281 	return 0;
282 }
283 
284 static bt_t *
285 bt_alloc(vmem_t *vm, vm_flag_t flags)
286 {
287 	bt_t *bt;
288 	VMEM_LOCK(vm);
289 	while (vm->vm_nfreetags <= BT_MINRESERVE && (flags & VM_POPULATING) == 0) {
290 		VMEM_UNLOCK(vm);
291 		if (bt_refill(vm, VM_NOSLEEP | VM_INSTANTFIT)) {
292 			return NULL;
293 		}
294 		VMEM_LOCK(vm);
295 	}
296 	bt = LIST_FIRST(&vm->vm_freetags);
297 	LIST_REMOVE(bt, bt_freelist);
298 	vm->vm_nfreetags--;
299 	VMEM_UNLOCK(vm);
300 
301 	return bt;
302 }
303 
304 static void
305 bt_free(vmem_t *vm, bt_t *bt)
306 {
307 
308 	VMEM_LOCK(vm);
309 	LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
310 	vm->vm_nfreetags++;
311 	VMEM_UNLOCK(vm);
312 }
313 
314 static void
315 bt_freetrim(vmem_t *vm, int freelimit)
316 {
317 	bt_t *t;
318 	LIST_HEAD(, vmem_btag) tofree;
319 
320 	LIST_INIT(&tofree);
321 
322 	VMEM_LOCK(vm);
323 	while (vm->vm_nfreetags > freelimit) {
324 		bt_t *bt = LIST_FIRST(&vm->vm_freetags);
325 		LIST_REMOVE(bt, bt_freelist);
326 		vm->vm_nfreetags--;
327 		if (bt >= static_bts
328 		    && bt < &static_bts[STATIC_BT_COUNT]) {
329 			mutex_enter(&vmem_btag_lock);
330 			LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
331 			vmem_btag_freelist_count++;
332 			mutex_exit(&vmem_btag_lock);
333 			VMEM_EVCNT_DECR(static_bt_inuse);
334 		} else {
335 			LIST_INSERT_HEAD(&tofree, bt, bt_freelist);
336 		}
337 	}
338 
339 	VMEM_UNLOCK(vm);
340 	while (!LIST_EMPTY(&tofree)) {
341 		t = LIST_FIRST(&tofree);
342 		LIST_REMOVE(t, bt_freelist);
343 		pool_put(&vmem_btag_pool, t);
344 	}
345 }
346 #endif	/* defined(_KERNEL) */
347 
348 /*
349  * freelist[0] ... [1, 1]
350  * freelist[1] ... [2, 3]
351  * freelist[2] ... [4, 7]
352  * freelist[3] ... [8, 15]
353  *  :
354  * freelist[n] ... [(1 << n), (1 << (n + 1)) - 1]
355  *  :
356  */
357 
358 static struct vmem_freelist *
359 bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
360 {
361 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
362 	const int idx = SIZE2ORDER(qsize);
363 
364 	KASSERT(size != 0 && qsize != 0);
365 	KASSERT((size & vm->vm_quantum_mask) == 0);
366 	KASSERT(idx >= 0);
367 	KASSERT(idx < VMEM_MAXORDER);
368 
369 	return &vm->vm_freelist[idx];
370 }
371 
372 /*
373  * bt_freehead_toalloc: return the freelist for the given size and allocation
374  * strategy.
375  *
376  * for VM_INSTANTFIT, return the list in which any blocks are large enough
377  * for the requested size.  otherwise, return the list which can have blocks
378  * large enough for the requested size.
379  */
380 
381 static struct vmem_freelist *
382 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, vm_flag_t strat)
383 {
384 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
385 	int idx = SIZE2ORDER(qsize);
386 
387 	KASSERT(size != 0 && qsize != 0);
388 	KASSERT((size & vm->vm_quantum_mask) == 0);
389 
390 	if (strat == VM_INSTANTFIT && ORDER2SIZE(idx) != qsize) {
391 		idx++;
392 		/* check too large request? */
393 	}
394 	KASSERT(idx >= 0);
395 	KASSERT(idx < VMEM_MAXORDER);
396 
397 	return &vm->vm_freelist[idx];
398 }
399 
400 /* ---- boundary tag hash */
401 
402 static struct vmem_hashlist *
403 bt_hashhead(vmem_t *vm, vmem_addr_t addr)
404 {
405 	struct vmem_hashlist *list;
406 	unsigned int hash;
407 
408 	hash = hash32_buf(&addr, sizeof(addr), HASH32_BUF_INIT);
409 	list = &vm->vm_hashlist[hash % vm->vm_hashsize];
410 
411 	return list;
412 }
413 
414 static bt_t *
415 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
416 {
417 	struct vmem_hashlist *list;
418 	bt_t *bt;
419 
420 	list = bt_hashhead(vm, addr);
421 	LIST_FOREACH(bt, list, bt_hashlist) {
422 		if (bt->bt_start == addr) {
423 			break;
424 		}
425 	}
426 
427 	return bt;
428 }
429 
430 static void
431 bt_rembusy(vmem_t *vm, bt_t *bt)
432 {
433 
434 	KASSERT(vm->vm_nbusytag > 0);
435 	vm->vm_inuse -= bt->bt_size;
436 	vm->vm_nbusytag--;
437 	LIST_REMOVE(bt, bt_hashlist);
438 }
439 
440 static void
441 bt_insbusy(vmem_t *vm, bt_t *bt)
442 {
443 	struct vmem_hashlist *list;
444 
445 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
446 
447 	list = bt_hashhead(vm, bt->bt_start);
448 	LIST_INSERT_HEAD(list, bt, bt_hashlist);
449 	vm->vm_nbusytag++;
450 	vm->vm_inuse += bt->bt_size;
451 }
452 
453 /* ---- boundary tag list */
454 
455 static void
456 bt_remseg(vmem_t *vm, bt_t *bt)
457 {
458 
459 	TAILQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
460 }
461 
462 static void
463 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
464 {
465 
466 	TAILQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
467 }
468 
469 static void
470 bt_insseg_tail(vmem_t *vm, bt_t *bt)
471 {
472 
473 	TAILQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
474 }
475 
476 static void
477 bt_remfree(vmem_t *vm, bt_t *bt)
478 {
479 
480 	KASSERT(bt->bt_type == BT_TYPE_FREE);
481 
482 	LIST_REMOVE(bt, bt_freelist);
483 }
484 
485 static void
486 bt_insfree(vmem_t *vm, bt_t *bt)
487 {
488 	struct vmem_freelist *list;
489 
490 	list = bt_freehead_tofree(vm, bt->bt_size);
491 	LIST_INSERT_HEAD(list, bt, bt_freelist);
492 }
493 
494 /* ---- vmem internal functions */
495 
496 #if defined(QCACHE)
497 static inline vm_flag_t
498 prf_to_vmf(int prflags)
499 {
500 	vm_flag_t vmflags;
501 
502 	KASSERT((prflags & ~(PR_LIMITFAIL | PR_WAITOK | PR_NOWAIT)) == 0);
503 	if ((prflags & PR_WAITOK) != 0) {
504 		vmflags = VM_SLEEP;
505 	} else {
506 		vmflags = VM_NOSLEEP;
507 	}
508 	return vmflags;
509 }
510 
511 static inline int
512 vmf_to_prf(vm_flag_t vmflags)
513 {
514 	int prflags;
515 
516 	if ((vmflags & VM_SLEEP) != 0) {
517 		prflags = PR_WAITOK;
518 	} else {
519 		prflags = PR_NOWAIT;
520 	}
521 	return prflags;
522 }
523 
524 static size_t
525 qc_poolpage_size(size_t qcache_max)
526 {
527 	int i;
528 
529 	for (i = 0; ORDER2SIZE(i) <= qcache_max * 3; i++) {
530 		/* nothing */
531 	}
532 	return ORDER2SIZE(i);
533 }
534 
535 static void *
536 qc_poolpage_alloc(struct pool *pool, int prflags)
537 {
538 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
539 	vmem_t *vm = qc->qc_vmem;
540 	vmem_addr_t addr;
541 
542 	if (vmem_alloc(vm, pool->pr_alloc->pa_pagesz,
543 	    prf_to_vmf(prflags) | VM_INSTANTFIT, &addr) != 0)
544 		return NULL;
545 	return (void *)addr;
546 }
547 
548 static void
549 qc_poolpage_free(struct pool *pool, void *addr)
550 {
551 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
552 	vmem_t *vm = qc->qc_vmem;
553 
554 	vmem_free(vm, (vmem_addr_t)addr, pool->pr_alloc->pa_pagesz);
555 }
556 
557 static void
558 qc_init(vmem_t *vm, size_t qcache_max, int ipl)
559 {
560 	qcache_t *prevqc;
561 	struct pool_allocator *pa;
562 	int qcache_idx_max;
563 	int i;
564 
565 	KASSERT((qcache_max & vm->vm_quantum_mask) == 0);
566 	if (qcache_max > (VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift)) {
567 		qcache_max = VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift;
568 	}
569 	vm->vm_qcache_max = qcache_max;
570 	pa = &vm->vm_qcache_allocator;
571 	memset(pa, 0, sizeof(*pa));
572 	pa->pa_alloc = qc_poolpage_alloc;
573 	pa->pa_free = qc_poolpage_free;
574 	pa->pa_pagesz = qc_poolpage_size(qcache_max);
575 
576 	qcache_idx_max = qcache_max >> vm->vm_quantum_shift;
577 	prevqc = NULL;
578 	for (i = qcache_idx_max; i > 0; i--) {
579 		qcache_t *qc = &vm->vm_qcache_store[i - 1];
580 		size_t size = i << vm->vm_quantum_shift;
581 		pool_cache_t pc;
582 
583 		qc->qc_vmem = vm;
584 		snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu",
585 		    vm->vm_name, size);
586 
587 		pc = pool_cache_init(size,
588 		    ORDER2SIZE(vm->vm_quantum_shift), 0,
589 		    PR_NOALIGN | PR_NOTOUCH | PR_RECURSIVE /* XXX */,
590 		    qc->qc_name, pa, ipl, NULL, NULL, NULL);
591 
592 		KASSERT(pc);
593 
594 		qc->qc_cache = pc;
595 		KASSERT(qc->qc_cache != NULL);	/* XXX */
596 		if (prevqc != NULL &&
597 		    qc->qc_cache->pc_pool.pr_itemsperpage ==
598 		    prevqc->qc_cache->pc_pool.pr_itemsperpage) {
599 			pool_cache_destroy(qc->qc_cache);
600 			vm->vm_qcache[i - 1] = prevqc;
601 			continue;
602 		}
603 		qc->qc_cache->pc_pool.pr_qcache = qc;
604 		vm->vm_qcache[i - 1] = qc;
605 		prevqc = qc;
606 	}
607 }
608 
609 static void
610 qc_destroy(vmem_t *vm)
611 {
612 	const qcache_t *prevqc;
613 	int i;
614 	int qcache_idx_max;
615 
616 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
617 	prevqc = NULL;
618 	for (i = 0; i < qcache_idx_max; i++) {
619 		qcache_t *qc = vm->vm_qcache[i];
620 
621 		if (prevqc == qc) {
622 			continue;
623 		}
624 		pool_cache_destroy(qc->qc_cache);
625 		prevqc = qc;
626 	}
627 }
628 #endif
629 
630 #if defined(_KERNEL)
631 static void
632 vmem_bootstrap(void)
633 {
634 
635 	mutex_init(&vmem_list_lock, MUTEX_DEFAULT, IPL_VM);
636 	mutex_init(&vmem_btag_lock, MUTEX_DEFAULT, IPL_VM);
637 	mutex_init(&vmem_btag_refill_lock, MUTEX_DEFAULT, IPL_VM);
638 
639 	while (static_bt_count-- > 0) {
640 		bt_t *bt = &static_bts[static_bt_count];
641 		LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
642 		VMEM_EVCNT_INCR(static_bt_count);
643 		vmem_btag_freelist_count++;
644 	}
645 	vmem_bootstrapped = TRUE;
646 }
647 
648 void
649 vmem_subsystem_init(vmem_t *vm)
650 {
651 
652 	kmem_va_meta_arena = vmem_init(&kmem_va_meta_arena_store, "vmem-va",
653 	    0, 0, PAGE_SIZE, vmem_alloc, vmem_free, vm,
654 	    0, VM_NOSLEEP | VM_BOOTSTRAP | VM_LARGEIMPORT,
655 	    IPL_VM);
656 
657 	kmem_meta_arena = vmem_init(&kmem_meta_arena_store, "vmem-meta",
658 	    0, 0, PAGE_SIZE,
659 	    uvm_km_kmem_alloc, uvm_km_kmem_free, kmem_va_meta_arena,
660 	    0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM);
661 
662 	pool_init(&vmem_btag_pool, sizeof(bt_t), 0, 0, PR_PHINPAGE,
663 		    "vmembt", &pool_allocator_vmem_meta, IPL_VM);
664 }
665 #endif /* defined(_KERNEL) */
666 
667 static int
668 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags,
669     int spanbttype)
670 {
671 	bt_t *btspan;
672 	bt_t *btfree;
673 
674 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
675 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
676 	KASSERT(spanbttype == BT_TYPE_SPAN ||
677 	    spanbttype == BT_TYPE_SPAN_STATIC);
678 
679 	btspan = bt_alloc(vm, flags);
680 	if (btspan == NULL) {
681 		return ENOMEM;
682 	}
683 	btfree = bt_alloc(vm, flags);
684 	if (btfree == NULL) {
685 		bt_free(vm, btspan);
686 		return ENOMEM;
687 	}
688 
689 	btspan->bt_type = spanbttype;
690 	btspan->bt_start = addr;
691 	btspan->bt_size = size;
692 
693 	btfree->bt_type = BT_TYPE_FREE;
694 	btfree->bt_start = addr;
695 	btfree->bt_size = size;
696 
697 	VMEM_LOCK(vm);
698 	bt_insseg_tail(vm, btspan);
699 	bt_insseg(vm, btfree, btspan);
700 	bt_insfree(vm, btfree);
701 	vm->vm_size += size;
702 	VMEM_UNLOCK(vm);
703 
704 	return 0;
705 }
706 
707 static void
708 vmem_destroy1(vmem_t *vm)
709 {
710 
711 #if defined(QCACHE)
712 	qc_destroy(vm);
713 #endif /* defined(QCACHE) */
714 	if (vm->vm_hashlist != NULL) {
715 		int i;
716 
717 		for (i = 0; i < vm->vm_hashsize; i++) {
718 			bt_t *bt;
719 
720 			while ((bt = LIST_FIRST(&vm->vm_hashlist[i])) != NULL) {
721 				KASSERT(bt->bt_type == BT_TYPE_SPAN_STATIC);
722 				bt_free(vm, bt);
723 			}
724 		}
725 		if (vm->vm_hashlist != &vm->vm_hash0) {
726 			xfree(vm->vm_hashlist,
727 			    sizeof(struct vmem_hashlist *) * vm->vm_hashsize);
728 		}
729 	}
730 
731 	bt_freetrim(vm, 0);
732 
733 	VMEM_CONDVAR_DESTROY(vm);
734 	VMEM_LOCK_DESTROY(vm);
735 	xfree(vm, sizeof(*vm));
736 }
737 
738 static int
739 vmem_import(vmem_t *vm, vmem_size_t size, vm_flag_t flags)
740 {
741 	vmem_addr_t addr;
742 	int rc;
743 
744 	if (vm->vm_importfn == NULL) {
745 		return EINVAL;
746 	}
747 
748 	if (vm->vm_flags & VM_LARGEIMPORT) {
749 		size *= 16;
750 	}
751 
752 	if (vm->vm_flags & VM_XIMPORT) {
753 		rc = ((vmem_ximport_t *)vm->vm_importfn)(vm->vm_arg, size,
754 		    &size, flags, &addr);
755 	} else {
756 		rc = (vm->vm_importfn)(vm->vm_arg, size, flags, &addr);
757 	}
758 	if (rc) {
759 		return ENOMEM;
760 	}
761 
762 	if (vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN) != 0) {
763 		(*vm->vm_releasefn)(vm->vm_arg, addr, size);
764 		return ENOMEM;
765 	}
766 
767 	return 0;
768 }
769 
770 static int
771 vmem_rehash(vmem_t *vm, size_t newhashsize, vm_flag_t flags)
772 {
773 	bt_t *bt;
774 	int i;
775 	struct vmem_hashlist *newhashlist;
776 	struct vmem_hashlist *oldhashlist;
777 	size_t oldhashsize;
778 
779 	KASSERT(newhashsize > 0);
780 
781 	newhashlist =
782 	    xmalloc(sizeof(struct vmem_hashlist *) * newhashsize, flags);
783 	if (newhashlist == NULL) {
784 		return ENOMEM;
785 	}
786 	for (i = 0; i < newhashsize; i++) {
787 		LIST_INIT(&newhashlist[i]);
788 	}
789 
790 	if (!VMEM_TRYLOCK(vm)) {
791 		xfree(newhashlist,
792 		    sizeof(struct vmem_hashlist *) * newhashsize);
793 		return EBUSY;
794 	}
795 	oldhashlist = vm->vm_hashlist;
796 	oldhashsize = vm->vm_hashsize;
797 	vm->vm_hashlist = newhashlist;
798 	vm->vm_hashsize = newhashsize;
799 	if (oldhashlist == NULL) {
800 		VMEM_UNLOCK(vm);
801 		return 0;
802 	}
803 	for (i = 0; i < oldhashsize; i++) {
804 		while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
805 			bt_rembusy(vm, bt); /* XXX */
806 			bt_insbusy(vm, bt);
807 		}
808 	}
809 	VMEM_UNLOCK(vm);
810 
811 	if (oldhashlist != &vm->vm_hash0) {
812 		xfree(oldhashlist,
813 		    sizeof(struct vmem_hashlist *) * oldhashsize);
814 	}
815 
816 	return 0;
817 }
818 
819 /*
820  * vmem_fit: check if a bt can satisfy the given restrictions.
821  *
822  * it's a caller's responsibility to ensure the region is big enough
823  * before calling us.
824  */
825 
826 static int
827 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align,
828     vmem_size_t phase, vmem_size_t nocross,
829     vmem_addr_t minaddr, vmem_addr_t maxaddr, vmem_addr_t *addrp)
830 {
831 	vmem_addr_t start;
832 	vmem_addr_t end;
833 
834 	KASSERT(size > 0);
835 	KASSERT(bt->bt_size >= size); /* caller's responsibility */
836 
837 	/*
838 	 * XXX assumption: vmem_addr_t and vmem_size_t are
839 	 * unsigned integer of the same size.
840 	 */
841 
842 	start = bt->bt_start;
843 	if (start < minaddr) {
844 		start = minaddr;
845 	}
846 	end = BT_END(bt);
847 	if (end > maxaddr) {
848 		end = maxaddr;
849 	}
850 	if (start > end) {
851 		return ENOMEM;
852 	}
853 
854 	start = VMEM_ALIGNUP(start - phase, align) + phase;
855 	if (start < bt->bt_start) {
856 		start += align;
857 	}
858 	if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
859 		KASSERT(align < nocross);
860 		start = VMEM_ALIGNUP(start - phase, nocross) + phase;
861 	}
862 	if (start <= end && end - start >= size - 1) {
863 		KASSERT((start & (align - 1)) == phase);
864 		KASSERT(!VMEM_CROSS_P(start, start + size - 1, nocross));
865 		KASSERT(minaddr <= start);
866 		KASSERT(maxaddr == 0 || start + size - 1 <= maxaddr);
867 		KASSERT(bt->bt_start <= start);
868 		KASSERT(BT_END(bt) - start >= size - 1);
869 		*addrp = start;
870 		return 0;
871 	}
872 	return ENOMEM;
873 }
874 
875 /* ---- vmem API */
876 
877 /*
878  * vmem_create_internal: creates a vmem arena.
879  */
880 
881 vmem_t *
882 vmem_init(vmem_t *vm, const char *name,
883     vmem_addr_t base, vmem_size_t size, vmem_size_t quantum,
884     vmem_import_t *importfn, vmem_release_t *releasefn,
885     vmem_t *arg, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
886 {
887 	int i;
888 
889 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
890 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
891 	KASSERT(quantum > 0);
892 
893 #if defined(_KERNEL)
894 	/* XXX: SMP, we get called early... */
895 	if (!vmem_bootstrapped) {
896 		vmem_bootstrap();
897 	}
898 #endif /* defined(_KERNEL) */
899 
900 	if (vm == NULL) {
901 		vm = xmalloc(sizeof(*vm), flags);
902 	}
903 	if (vm == NULL) {
904 		return NULL;
905 	}
906 
907 	VMEM_CONDVAR_INIT(vm, "vmem");
908 	VMEM_LOCK_INIT(vm, ipl);
909 	vm->vm_flags = flags;
910 	vm->vm_nfreetags = 0;
911 	LIST_INIT(&vm->vm_freetags);
912 	strlcpy(vm->vm_name, name, sizeof(vm->vm_name));
913 	vm->vm_quantum_mask = quantum - 1;
914 	vm->vm_quantum_shift = SIZE2ORDER(quantum);
915 	KASSERT(ORDER2SIZE(vm->vm_quantum_shift) == quantum);
916 	vm->vm_importfn = importfn;
917 	vm->vm_releasefn = releasefn;
918 	vm->vm_arg = arg;
919 	vm->vm_nbusytag = 0;
920 	vm->vm_size = 0;
921 	vm->vm_inuse = 0;
922 #if defined(QCACHE)
923 	qc_init(vm, qcache_max, ipl);
924 #endif /* defined(QCACHE) */
925 
926 	TAILQ_INIT(&vm->vm_seglist);
927 	for (i = 0; i < VMEM_MAXORDER; i++) {
928 		LIST_INIT(&vm->vm_freelist[i]);
929 	}
930 	memset(&vm->vm_hash0, 0, sizeof(struct vmem_hashlist));
931 	vm->vm_hashsize = 1;
932 	vm->vm_hashlist = &vm->vm_hash0;
933 
934 	if (size != 0) {
935 		if (vmem_add(vm, base, size, flags) != 0) {
936 			vmem_destroy1(vm);
937 			return NULL;
938 		}
939 	}
940 
941 #if defined(_KERNEL)
942 	if (flags & VM_BOOTSTRAP) {
943 		bt_refill(vm, VM_NOSLEEP);
944 	}
945 
946 	mutex_enter(&vmem_list_lock);
947 	LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist);
948 	mutex_exit(&vmem_list_lock);
949 #endif /* defined(_KERNEL) */
950 
951 	return vm;
952 }
953 
954 
955 
956 /*
957  * vmem_create: create an arena.
958  *
959  * => must not be called from interrupt context.
960  */
961 
962 vmem_t *
963 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
964     vmem_size_t quantum, vmem_import_t *importfn, vmem_release_t *releasefn,
965     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
966 {
967 
968 	KASSERT((flags & (VM_XIMPORT)) == 0);
969 
970 	return vmem_init(NULL, name, base, size, quantum,
971 	    importfn, releasefn, source, qcache_max, flags, ipl);
972 }
973 
974 /*
975  * vmem_xcreate: create an arena takes alternative import func.
976  *
977  * => must not be called from interrupt context.
978  */
979 
980 vmem_t *
981 vmem_xcreate(const char *name, vmem_addr_t base, vmem_size_t size,
982     vmem_size_t quantum, vmem_ximport_t *importfn, vmem_release_t *releasefn,
983     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
984 {
985 
986 	KASSERT((flags & (VM_XIMPORT)) == 0);
987 
988 	return vmem_init(NULL, name, base, size, quantum,
989 	    (vmem_import_t *)importfn, releasefn, source,
990 	    qcache_max, flags | VM_XIMPORT, ipl);
991 }
992 
993 void
994 vmem_destroy(vmem_t *vm)
995 {
996 
997 #if defined(_KERNEL)
998 	mutex_enter(&vmem_list_lock);
999 	LIST_REMOVE(vm, vm_alllist);
1000 	mutex_exit(&vmem_list_lock);
1001 #endif /* defined(_KERNEL) */
1002 
1003 	vmem_destroy1(vm);
1004 }
1005 
1006 vmem_size_t
1007 vmem_roundup_size(vmem_t *vm, vmem_size_t size)
1008 {
1009 
1010 	return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
1011 }
1012 
1013 /*
1014  * vmem_alloc: allocate resource from the arena.
1015  */
1016 
1017 int
1018 vmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, vmem_addr_t *addrp)
1019 {
1020 	const vm_flag_t strat __diagused = flags & VM_FITMASK;
1021 
1022 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
1023 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
1024 
1025 	KASSERT(size > 0);
1026 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
1027 	if ((flags & VM_SLEEP) != 0) {
1028 		ASSERT_SLEEPABLE();
1029 	}
1030 
1031 #if defined(QCACHE)
1032 	if (size <= vm->vm_qcache_max) {
1033 		void *p;
1034 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1035 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1036 
1037 		p = pool_cache_get(qc->qc_cache, vmf_to_prf(flags));
1038 		if (addrp != NULL)
1039 			*addrp = (vmem_addr_t)p;
1040 		return (p == NULL) ? ENOMEM : 0;
1041 	}
1042 #endif /* defined(QCACHE) */
1043 
1044 	return vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
1045 	    flags, addrp);
1046 }
1047 
1048 int
1049 vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align,
1050     const vmem_size_t phase, const vmem_size_t nocross,
1051     const vmem_addr_t minaddr, const vmem_addr_t maxaddr, const vm_flag_t flags,
1052     vmem_addr_t *addrp)
1053 {
1054 	struct vmem_freelist *list;
1055 	struct vmem_freelist *first;
1056 	struct vmem_freelist *end;
1057 	bt_t *bt;
1058 	bt_t *btnew;
1059 	bt_t *btnew2;
1060 	const vmem_size_t size = vmem_roundup_size(vm, size0);
1061 	vm_flag_t strat = flags & VM_FITMASK;
1062 	vmem_addr_t start;
1063 	int rc;
1064 
1065 	KASSERT(size0 > 0);
1066 	KASSERT(size > 0);
1067 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
1068 	if ((flags & VM_SLEEP) != 0) {
1069 		ASSERT_SLEEPABLE();
1070 	}
1071 	KASSERT((align & vm->vm_quantum_mask) == 0);
1072 	KASSERT((align & (align - 1)) == 0);
1073 	KASSERT((phase & vm->vm_quantum_mask) == 0);
1074 	KASSERT((nocross & vm->vm_quantum_mask) == 0);
1075 	KASSERT((nocross & (nocross - 1)) == 0);
1076 	KASSERT((align == 0 && phase == 0) || phase < align);
1077 	KASSERT(nocross == 0 || nocross >= size);
1078 	KASSERT(minaddr <= maxaddr);
1079 	KASSERT(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
1080 
1081 	if (align == 0) {
1082 		align = vm->vm_quantum_mask + 1;
1083 	}
1084 
1085 	/*
1086 	 * allocate boundary tags before acquiring the vmem lock.
1087 	 */
1088 	btnew = bt_alloc(vm, flags);
1089 	if (btnew == NULL) {
1090 		return ENOMEM;
1091 	}
1092 	btnew2 = bt_alloc(vm, flags); /* XXX not necessary if no restrictions */
1093 	if (btnew2 == NULL) {
1094 		bt_free(vm, btnew);
1095 		return ENOMEM;
1096 	}
1097 
1098 	/*
1099 	 * choose a free block from which we allocate.
1100 	 */
1101 retry_strat:
1102 	first = bt_freehead_toalloc(vm, size, strat);
1103 	end = &vm->vm_freelist[VMEM_MAXORDER];
1104 retry:
1105 	bt = NULL;
1106 	VMEM_LOCK(vm);
1107 	vmem_check(vm);
1108 	if (strat == VM_INSTANTFIT) {
1109 		/*
1110 		 * just choose the first block which satisfies our restrictions.
1111 		 *
1112 		 * note that we don't need to check the size of the blocks
1113 		 * because any blocks found on these list should be larger than
1114 		 * the given size.
1115 		 */
1116 		for (list = first; list < end; list++) {
1117 			bt = LIST_FIRST(list);
1118 			if (bt != NULL) {
1119 				rc = vmem_fit(bt, size, align, phase,
1120 				    nocross, minaddr, maxaddr, &start);
1121 				if (rc == 0) {
1122 					goto gotit;
1123 				}
1124 				/*
1125 				 * don't bother to follow the bt_freelist link
1126 				 * here.  the list can be very long and we are
1127 				 * told to run fast.  blocks from the later free
1128 				 * lists are larger and have better chances to
1129 				 * satisfy our restrictions.
1130 				 */
1131 			}
1132 		}
1133 	} else { /* VM_BESTFIT */
1134 		/*
1135 		 * we assume that, for space efficiency, it's better to
1136 		 * allocate from a smaller block.  thus we will start searching
1137 		 * from the lower-order list than VM_INSTANTFIT.
1138 		 * however, don't bother to find the smallest block in a free
1139 		 * list because the list can be very long.  we can revisit it
1140 		 * if/when it turns out to be a problem.
1141 		 *
1142 		 * note that the 'first' list can contain blocks smaller than
1143 		 * the requested size.  thus we need to check bt_size.
1144 		 */
1145 		for (list = first; list < end; list++) {
1146 			LIST_FOREACH(bt, list, bt_freelist) {
1147 				if (bt->bt_size >= size) {
1148 					rc = vmem_fit(bt, size, align, phase,
1149 					    nocross, minaddr, maxaddr, &start);
1150 					if (rc == 0) {
1151 						goto gotit;
1152 					}
1153 				}
1154 			}
1155 		}
1156 	}
1157 	VMEM_UNLOCK(vm);
1158 #if 1
1159 	if (strat == VM_INSTANTFIT) {
1160 		strat = VM_BESTFIT;
1161 		goto retry_strat;
1162 	}
1163 #endif
1164 	if (align != vm->vm_quantum_mask + 1 || phase != 0 || nocross != 0) {
1165 
1166 		/*
1167 		 * XXX should try to import a region large enough to
1168 		 * satisfy restrictions?
1169 		 */
1170 
1171 		goto fail;
1172 	}
1173 	/* XXX eeek, minaddr & maxaddr not respected */
1174 	if (vmem_import(vm, size, flags) == 0) {
1175 		goto retry;
1176 	}
1177 	/* XXX */
1178 
1179 	if ((flags & VM_SLEEP) != 0) {
1180 #if defined(_KERNEL)
1181 		mutex_spin_enter(&uvm_fpageqlock);
1182 		uvm_kick_pdaemon();
1183 		mutex_spin_exit(&uvm_fpageqlock);
1184 #endif
1185 		VMEM_LOCK(vm);
1186 		VMEM_CONDVAR_WAIT(vm);
1187 		VMEM_UNLOCK(vm);
1188 		goto retry;
1189 	}
1190 fail:
1191 	bt_free(vm, btnew);
1192 	bt_free(vm, btnew2);
1193 	return ENOMEM;
1194 
1195 gotit:
1196 	KASSERT(bt->bt_type == BT_TYPE_FREE);
1197 	KASSERT(bt->bt_size >= size);
1198 	bt_remfree(vm, bt);
1199 	vmem_check(vm);
1200 	if (bt->bt_start != start) {
1201 		btnew2->bt_type = BT_TYPE_FREE;
1202 		btnew2->bt_start = bt->bt_start;
1203 		btnew2->bt_size = start - bt->bt_start;
1204 		bt->bt_start = start;
1205 		bt->bt_size -= btnew2->bt_size;
1206 		bt_insfree(vm, btnew2);
1207 		bt_insseg(vm, btnew2, TAILQ_PREV(bt, vmem_seglist, bt_seglist));
1208 		btnew2 = NULL;
1209 		vmem_check(vm);
1210 	}
1211 	KASSERT(bt->bt_start == start);
1212 	if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
1213 		/* split */
1214 		btnew->bt_type = BT_TYPE_BUSY;
1215 		btnew->bt_start = bt->bt_start;
1216 		btnew->bt_size = size;
1217 		bt->bt_start = bt->bt_start + size;
1218 		bt->bt_size -= size;
1219 		bt_insfree(vm, bt);
1220 		bt_insseg(vm, btnew, TAILQ_PREV(bt, vmem_seglist, bt_seglist));
1221 		bt_insbusy(vm, btnew);
1222 		vmem_check(vm);
1223 		VMEM_UNLOCK(vm);
1224 	} else {
1225 		bt->bt_type = BT_TYPE_BUSY;
1226 		bt_insbusy(vm, bt);
1227 		vmem_check(vm);
1228 		VMEM_UNLOCK(vm);
1229 		bt_free(vm, btnew);
1230 		btnew = bt;
1231 	}
1232 	if (btnew2 != NULL) {
1233 		bt_free(vm, btnew2);
1234 	}
1235 	KASSERT(btnew->bt_size >= size);
1236 	btnew->bt_type = BT_TYPE_BUSY;
1237 
1238 	if (addrp != NULL)
1239 		*addrp = btnew->bt_start;
1240 	return 0;
1241 }
1242 
1243 /*
1244  * vmem_free: free the resource to the arena.
1245  */
1246 
1247 void
1248 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1249 {
1250 
1251 	KASSERT(size > 0);
1252 
1253 #if defined(QCACHE)
1254 	if (size <= vm->vm_qcache_max) {
1255 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1256 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1257 
1258 		pool_cache_put(qc->qc_cache, (void *)addr);
1259 		return;
1260 	}
1261 #endif /* defined(QCACHE) */
1262 
1263 	vmem_xfree(vm, addr, size);
1264 }
1265 
1266 void
1267 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1268 {
1269 	bt_t *bt;
1270 	bt_t *t;
1271 	LIST_HEAD(, vmem_btag) tofree;
1272 
1273 	LIST_INIT(&tofree);
1274 
1275 	KASSERT(size > 0);
1276 
1277 	VMEM_LOCK(vm);
1278 
1279 	bt = bt_lookupbusy(vm, addr);
1280 	KASSERT(bt != NULL);
1281 	KASSERT(bt->bt_start == addr);
1282 	KASSERT(bt->bt_size == vmem_roundup_size(vm, size) ||
1283 	    bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
1284 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
1285 	bt_rembusy(vm, bt);
1286 	bt->bt_type = BT_TYPE_FREE;
1287 
1288 	/* coalesce */
1289 	t = TAILQ_NEXT(bt, bt_seglist);
1290 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1291 		KASSERT(BT_END(bt) < t->bt_start);	/* YYY */
1292 		bt_remfree(vm, t);
1293 		bt_remseg(vm, t);
1294 		bt->bt_size += t->bt_size;
1295 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1296 	}
1297 	t = TAILQ_PREV(bt, vmem_seglist, bt_seglist);
1298 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1299 		KASSERT(BT_END(t) < bt->bt_start);	/* YYY */
1300 		bt_remfree(vm, t);
1301 		bt_remseg(vm, t);
1302 		bt->bt_size += t->bt_size;
1303 		bt->bt_start = t->bt_start;
1304 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1305 	}
1306 
1307 	t = TAILQ_PREV(bt, vmem_seglist, bt_seglist);
1308 	KASSERT(t != NULL);
1309 	KASSERT(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY);
1310 	if (vm->vm_releasefn != NULL && t->bt_type == BT_TYPE_SPAN &&
1311 	    t->bt_size == bt->bt_size) {
1312 		vmem_addr_t spanaddr;
1313 		vmem_size_t spansize;
1314 
1315 		KASSERT(t->bt_start == bt->bt_start);
1316 		spanaddr = bt->bt_start;
1317 		spansize = bt->bt_size;
1318 		bt_remseg(vm, bt);
1319 		LIST_INSERT_HEAD(&tofree, bt, bt_freelist);
1320 		bt_remseg(vm, t);
1321 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1322 		vm->vm_size -= spansize;
1323 		VMEM_CONDVAR_BROADCAST(vm);
1324 		VMEM_UNLOCK(vm);
1325 		(*vm->vm_releasefn)(vm->vm_arg, spanaddr, spansize);
1326 	} else {
1327 		bt_insfree(vm, bt);
1328 		VMEM_CONDVAR_BROADCAST(vm);
1329 		VMEM_UNLOCK(vm);
1330 	}
1331 
1332 	while (!LIST_EMPTY(&tofree)) {
1333 		t = LIST_FIRST(&tofree);
1334 		LIST_REMOVE(t, bt_freelist);
1335 		bt_free(vm, t);
1336 	}
1337 
1338 	bt_freetrim(vm, BT_MAXFREE);
1339 }
1340 
1341 /*
1342  * vmem_add:
1343  *
1344  * => caller must ensure appropriate spl,
1345  *    if the arena can be accessed from interrupt context.
1346  */
1347 
1348 int
1349 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags)
1350 {
1351 
1352 	return vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN_STATIC);
1353 }
1354 
1355 /*
1356  * vmem_size: information about arenas size
1357  *
1358  * => return free/allocated size in arena
1359  */
1360 vmem_size_t
1361 vmem_size(vmem_t *vm, int typemask)
1362 {
1363 
1364 	switch (typemask) {
1365 	case VMEM_ALLOC:
1366 		return vm->vm_inuse;
1367 	case VMEM_FREE:
1368 		return vm->vm_size - vm->vm_inuse;
1369 	case VMEM_FREE|VMEM_ALLOC:
1370 		return vm->vm_size;
1371 	default:
1372 		panic("vmem_size");
1373 	}
1374 }
1375 
1376 /* ---- rehash */
1377 
1378 #if defined(_KERNEL)
1379 static struct callout vmem_rehash_ch;
1380 static int vmem_rehash_interval;
1381 static struct workqueue *vmem_rehash_wq;
1382 static struct work vmem_rehash_wk;
1383 
1384 static void
1385 vmem_rehash_all(struct work *wk, void *dummy)
1386 {
1387 	vmem_t *vm;
1388 
1389 	KASSERT(wk == &vmem_rehash_wk);
1390 	mutex_enter(&vmem_list_lock);
1391 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1392 		size_t desired;
1393 		size_t current;
1394 
1395 		if (!VMEM_TRYLOCK(vm)) {
1396 			continue;
1397 		}
1398 		desired = vm->vm_nbusytag;
1399 		current = vm->vm_hashsize;
1400 		VMEM_UNLOCK(vm);
1401 
1402 		if (desired > VMEM_HASHSIZE_MAX) {
1403 			desired = VMEM_HASHSIZE_MAX;
1404 		} else if (desired < VMEM_HASHSIZE_MIN) {
1405 			desired = VMEM_HASHSIZE_MIN;
1406 		}
1407 		if (desired > current * 2 || desired * 2 < current) {
1408 			vmem_rehash(vm, desired, VM_NOSLEEP);
1409 		}
1410 	}
1411 	mutex_exit(&vmem_list_lock);
1412 
1413 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1414 }
1415 
1416 static void
1417 vmem_rehash_all_kick(void *dummy)
1418 {
1419 
1420 	workqueue_enqueue(vmem_rehash_wq, &vmem_rehash_wk, NULL);
1421 }
1422 
1423 void
1424 vmem_rehash_start(void)
1425 {
1426 	int error;
1427 
1428 	error = workqueue_create(&vmem_rehash_wq, "vmem_rehash",
1429 	    vmem_rehash_all, NULL, PRI_VM, IPL_SOFTCLOCK, WQ_MPSAFE);
1430 	if (error) {
1431 		panic("%s: workqueue_create %d\n", __func__, error);
1432 	}
1433 	callout_init(&vmem_rehash_ch, CALLOUT_MPSAFE);
1434 	callout_setfunc(&vmem_rehash_ch, vmem_rehash_all_kick, NULL);
1435 
1436 	vmem_rehash_interval = hz * 10;
1437 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1438 }
1439 #endif /* defined(_KERNEL) */
1440 
1441 /* ---- debug */
1442 
1443 #if defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY)
1444 
1445 static void bt_dump(const bt_t *, void (*)(const char *, ...)
1446     __printflike(1, 2));
1447 
1448 static const char *
1449 bt_type_string(int type)
1450 {
1451 	static const char * const table[] = {
1452 		[BT_TYPE_BUSY] = "busy",
1453 		[BT_TYPE_FREE] = "free",
1454 		[BT_TYPE_SPAN] = "span",
1455 		[BT_TYPE_SPAN_STATIC] = "static span",
1456 	};
1457 
1458 	if (type >= __arraycount(table)) {
1459 		return "BOGUS";
1460 	}
1461 	return table[type];
1462 }
1463 
1464 static void
1465 bt_dump(const bt_t *bt, void (*pr)(const char *, ...))
1466 {
1467 
1468 	(*pr)("\t%p: %" PRIu64 ", %" PRIu64 ", %d(%s)\n",
1469 	    bt, (uint64_t)bt->bt_start, (uint64_t)bt->bt_size,
1470 	    bt->bt_type, bt_type_string(bt->bt_type));
1471 }
1472 
1473 static void
1474 vmem_dump(const vmem_t *vm , void (*pr)(const char *, ...) __printflike(1, 2))
1475 {
1476 	const bt_t *bt;
1477 	int i;
1478 
1479 	(*pr)("vmem %p '%s'\n", vm, vm->vm_name);
1480 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1481 		bt_dump(bt, pr);
1482 	}
1483 
1484 	for (i = 0; i < VMEM_MAXORDER; i++) {
1485 		const struct vmem_freelist *fl = &vm->vm_freelist[i];
1486 
1487 		if (LIST_EMPTY(fl)) {
1488 			continue;
1489 		}
1490 
1491 		(*pr)("freelist[%d]\n", i);
1492 		LIST_FOREACH(bt, fl, bt_freelist) {
1493 			bt_dump(bt, pr);
1494 		}
1495 	}
1496 }
1497 
1498 #endif /* defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY) */
1499 
1500 #if defined(DDB)
1501 static bt_t *
1502 vmem_whatis_lookup(vmem_t *vm, uintptr_t addr)
1503 {
1504 	bt_t *bt;
1505 
1506 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1507 		if (BT_ISSPAN_P(bt)) {
1508 			continue;
1509 		}
1510 		if (bt->bt_start <= addr && addr <= BT_END(bt)) {
1511 			return bt;
1512 		}
1513 	}
1514 
1515 	return NULL;
1516 }
1517 
1518 void
1519 vmem_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1520 {
1521 	vmem_t *vm;
1522 
1523 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1524 		bt_t *bt;
1525 
1526 		bt = vmem_whatis_lookup(vm, addr);
1527 		if (bt == NULL) {
1528 			continue;
1529 		}
1530 		(*pr)("%p is %p+%zu in VMEM '%s' (%s)\n",
1531 		    (void *)addr, (void *)bt->bt_start,
1532 		    (size_t)(addr - bt->bt_start), vm->vm_name,
1533 		    (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free");
1534 	}
1535 }
1536 
1537 void
1538 vmem_printall(const char *modif, void (*pr)(const char *, ...))
1539 {
1540 	const vmem_t *vm;
1541 
1542 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1543 		vmem_dump(vm, pr);
1544 	}
1545 }
1546 
1547 void
1548 vmem_print(uintptr_t addr, const char *modif, void (*pr)(const char *, ...))
1549 {
1550 	const vmem_t *vm = (const void *)addr;
1551 
1552 	vmem_dump(vm, pr);
1553 }
1554 #endif /* defined(DDB) */
1555 
1556 #if defined(_KERNEL)
1557 #define vmem_printf printf
1558 #else
1559 #include <stdio.h>
1560 #include <stdarg.h>
1561 
1562 static void
1563 vmem_printf(const char *fmt, ...)
1564 {
1565 	va_list ap;
1566 	va_start(ap, fmt);
1567 	vprintf(fmt, ap);
1568 	va_end(ap);
1569 }
1570 #endif
1571 
1572 #if defined(VMEM_SANITY)
1573 
1574 static bool
1575 vmem_check_sanity(vmem_t *vm)
1576 {
1577 	const bt_t *bt, *bt2;
1578 
1579 	KASSERT(vm != NULL);
1580 
1581 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1582 		if (bt->bt_start > BT_END(bt)) {
1583 			printf("corrupted tag\n");
1584 			bt_dump(bt, vmem_printf);
1585 			return false;
1586 		}
1587 	}
1588 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1589 		TAILQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) {
1590 			if (bt == bt2) {
1591 				continue;
1592 			}
1593 			if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) {
1594 				continue;
1595 			}
1596 			if (bt->bt_start <= BT_END(bt2) &&
1597 			    bt2->bt_start <= BT_END(bt)) {
1598 				printf("overwrapped tags\n");
1599 				bt_dump(bt, vmem_printf);
1600 				bt_dump(bt2, vmem_printf);
1601 				return false;
1602 			}
1603 		}
1604 	}
1605 
1606 	return true;
1607 }
1608 
1609 static void
1610 vmem_check(vmem_t *vm)
1611 {
1612 
1613 	if (!vmem_check_sanity(vm)) {
1614 		panic("insanity vmem %p", vm);
1615 	}
1616 }
1617 
1618 #endif /* defined(VMEM_SANITY) */
1619 
1620 #if defined(UNITTEST)
1621 int
1622 main(void)
1623 {
1624 	int rc;
1625 	vmem_t *vm;
1626 	vmem_addr_t p;
1627 	struct reg {
1628 		vmem_addr_t p;
1629 		vmem_size_t sz;
1630 		bool x;
1631 	} *reg = NULL;
1632 	int nreg = 0;
1633 	int nalloc = 0;
1634 	int nfree = 0;
1635 	vmem_size_t total = 0;
1636 #if 1
1637 	vm_flag_t strat = VM_INSTANTFIT;
1638 #else
1639 	vm_flag_t strat = VM_BESTFIT;
1640 #endif
1641 
1642 	vm = vmem_create("test", 0, 0, 1, NULL, NULL, NULL, 0, VM_SLEEP,
1643 #ifdef _KERNEL
1644 	    IPL_NONE
1645 #else
1646 	    0
1647 #endif
1648 	    );
1649 	if (vm == NULL) {
1650 		printf("vmem_create\n");
1651 		exit(EXIT_FAILURE);
1652 	}
1653 	vmem_dump(vm, vmem_printf);
1654 
1655 	rc = vmem_add(vm, 0, 50, VM_SLEEP);
1656 	assert(rc == 0);
1657 	rc = vmem_add(vm, 100, 200, VM_SLEEP);
1658 	assert(rc == 0);
1659 	rc = vmem_add(vm, 2000, 1, VM_SLEEP);
1660 	assert(rc == 0);
1661 	rc = vmem_add(vm, 40000, 65536, VM_SLEEP);
1662 	assert(rc == 0);
1663 	rc = vmem_add(vm, 10000, 10000, VM_SLEEP);
1664 	assert(rc == 0);
1665 	rc = vmem_add(vm, 500, 1000, VM_SLEEP);
1666 	assert(rc == 0);
1667 	rc = vmem_add(vm, 0xffffff00, 0x100, VM_SLEEP);
1668 	assert(rc == 0);
1669 	rc = vmem_xalloc(vm, 0x101, 0, 0, 0,
1670 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1671 	assert(rc != 0);
1672 	rc = vmem_xalloc(vm, 50, 0, 0, 0, 0, 49, strat|VM_SLEEP, &p);
1673 	assert(rc == 0 && p == 0);
1674 	vmem_xfree(vm, p, 50);
1675 	rc = vmem_xalloc(vm, 25, 0, 0, 0, 0, 24, strat|VM_SLEEP, &p);
1676 	assert(rc == 0 && p == 0);
1677 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1678 	    0xffffff01, 0xffffffff, strat|VM_SLEEP, &p);
1679 	assert(rc != 0);
1680 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1681 	    0xffffff00, 0xfffffffe, strat|VM_SLEEP, &p);
1682 	assert(rc != 0);
1683 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1684 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1685 	assert(rc == 0);
1686 	vmem_dump(vm, vmem_printf);
1687 	for (;;) {
1688 		struct reg *r;
1689 		int t = rand() % 100;
1690 
1691 		if (t > 45) {
1692 			/* alloc */
1693 			vmem_size_t sz = rand() % 500 + 1;
1694 			bool x;
1695 			vmem_size_t align, phase, nocross;
1696 			vmem_addr_t minaddr, maxaddr;
1697 
1698 			if (t > 70) {
1699 				x = true;
1700 				/* XXX */
1701 				align = 1 << (rand() % 15);
1702 				phase = rand() % 65536;
1703 				nocross = 1 << (rand() % 15);
1704 				if (align <= phase) {
1705 					phase = 0;
1706 				}
1707 				if (VMEM_CROSS_P(phase, phase + sz - 1,
1708 				    nocross)) {
1709 					nocross = 0;
1710 				}
1711 				do {
1712 					minaddr = rand() % 50000;
1713 					maxaddr = rand() % 70000;
1714 				} while (minaddr > maxaddr);
1715 				printf("=== xalloc %" PRIu64
1716 				    " align=%" PRIu64 ", phase=%" PRIu64
1717 				    ", nocross=%" PRIu64 ", min=%" PRIu64
1718 				    ", max=%" PRIu64 "\n",
1719 				    (uint64_t)sz,
1720 				    (uint64_t)align,
1721 				    (uint64_t)phase,
1722 				    (uint64_t)nocross,
1723 				    (uint64_t)minaddr,
1724 				    (uint64_t)maxaddr);
1725 				rc = vmem_xalloc(vm, sz, align, phase, nocross,
1726 				    minaddr, maxaddr, strat|VM_SLEEP, &p);
1727 			} else {
1728 				x = false;
1729 				printf("=== alloc %" PRIu64 "\n", (uint64_t)sz);
1730 				rc = vmem_alloc(vm, sz, strat|VM_SLEEP, &p);
1731 			}
1732 			printf("-> %" PRIu64 "\n", (uint64_t)p);
1733 			vmem_dump(vm, vmem_printf);
1734 			if (rc != 0) {
1735 				if (x) {
1736 					continue;
1737 				}
1738 				break;
1739 			}
1740 			nreg++;
1741 			reg = realloc(reg, sizeof(*reg) * nreg);
1742 			r = &reg[nreg - 1];
1743 			r->p = p;
1744 			r->sz = sz;
1745 			r->x = x;
1746 			total += sz;
1747 			nalloc++;
1748 		} else if (nreg != 0) {
1749 			/* free */
1750 			r = &reg[rand() % nreg];
1751 			printf("=== free %" PRIu64 ", %" PRIu64 "\n",
1752 			    (uint64_t)r->p, (uint64_t)r->sz);
1753 			if (r->x) {
1754 				vmem_xfree(vm, r->p, r->sz);
1755 			} else {
1756 				vmem_free(vm, r->p, r->sz);
1757 			}
1758 			total -= r->sz;
1759 			vmem_dump(vm, vmem_printf);
1760 			*r = reg[nreg - 1];
1761 			nreg--;
1762 			nfree++;
1763 		}
1764 		printf("total=%" PRIu64 "\n", (uint64_t)total);
1765 	}
1766 	fprintf(stderr, "total=%" PRIu64 ", nalloc=%d, nfree=%d\n",
1767 	    (uint64_t)total, nalloc, nfree);
1768 	exit(EXIT_SUCCESS);
1769 }
1770 #endif /* defined(UNITTEST) */
1771