xref: /netbsd-src/sys/kern/subr_vmem.c (revision ba65fde2d7fefa7d39838fa5fa855e62bd606b5e)
1 /*	$NetBSD: subr_vmem.c,v 1.82 2013/02/09 00:31:21 christos 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 
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: subr_vmem.c,v 1.82 2013/02/09 00:31:21 christos Exp $");
38 
39 #if defined(_KERNEL)
40 #include "opt_ddb.h"
41 #endif /* defined(_KERNEL) */
42 
43 #include <sys/param.h>
44 #include <sys/hash.h>
45 #include <sys/queue.h>
46 #include <sys/bitops.h>
47 
48 #if defined(_KERNEL)
49 #include <sys/systm.h>
50 #include <sys/kernel.h>	/* hz */
51 #include <sys/callout.h>
52 #include <sys/kmem.h>
53 #include <sys/pool.h>
54 #include <sys/vmem.h>
55 #include <sys/vmem_impl.h>
56 #include <sys/workqueue.h>
57 #include <sys/atomic.h>
58 #include <uvm/uvm.h>
59 #include <uvm/uvm_extern.h>
60 #include <uvm/uvm_km.h>
61 #include <uvm/uvm_page.h>
62 #include <uvm/uvm_pdaemon.h>
63 #else /* defined(_KERNEL) */
64 #include <stdio.h>
65 #include <errno.h>
66 #include <assert.h>
67 #include <stdlib.h>
68 #include <string.h>
69 #include "../sys/vmem.h"
70 #include "../sys/vmem_impl.h"
71 #endif /* defined(_KERNEL) */
72 
73 
74 #if defined(_KERNEL)
75 #include <sys/evcnt.h>
76 #define VMEM_EVCNT_DEFINE(name) \
77 struct evcnt vmem_evcnt_##name = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, \
78     "vmemev", #name); \
79 EVCNT_ATTACH_STATIC(vmem_evcnt_##name);
80 #define VMEM_EVCNT_INCR(ev)	vmem_evcnt_##ev.ev_count++
81 #define VMEM_EVCNT_DECR(ev)	vmem_evcnt_##ev.ev_count--
82 
83 VMEM_EVCNT_DEFINE(bt_pages)
84 VMEM_EVCNT_DEFINE(bt_count)
85 VMEM_EVCNT_DEFINE(bt_inuse)
86 
87 #define	VMEM_CONDVAR_INIT(vm, wchan)	cv_init(&vm->vm_cv, wchan)
88 #define	VMEM_CONDVAR_DESTROY(vm)	cv_destroy(&vm->vm_cv)
89 #define	VMEM_CONDVAR_WAIT(vm)		cv_wait(&vm->vm_cv, &vm->vm_lock)
90 #define	VMEM_CONDVAR_BROADCAST(vm)	cv_broadcast(&vm->vm_cv)
91 
92 #else /* defined(_KERNEL) */
93 
94 #define VMEM_EVCNT_INCR(ev)	/* nothing */
95 #define VMEM_EVCNT_DECR(ev)	/* nothing */
96 
97 #define	VMEM_CONDVAR_INIT(vm, wchan)	/* nothing */
98 #define	VMEM_CONDVAR_DESTROY(vm)	/* nothing */
99 #define	VMEM_CONDVAR_WAIT(vm)		/* nothing */
100 #define	VMEM_CONDVAR_BROADCAST(vm)	/* nothing */
101 
102 #define	UNITTEST
103 #define	KASSERT(a)		assert(a)
104 #define	mutex_init(a, b, c)	/* nothing */
105 #define	mutex_destroy(a)	/* nothing */
106 #define	mutex_enter(a)		/* nothing */
107 #define	mutex_tryenter(a)	true
108 #define	mutex_exit(a)		/* nothing */
109 #define	mutex_owned(a)		/* nothing */
110 #define	ASSERT_SLEEPABLE()	/* nothing */
111 #define	panic(...)		printf(__VA_ARGS__); abort()
112 #endif /* defined(_KERNEL) */
113 
114 #if defined(VMEM_SANITY)
115 static void vmem_check(vmem_t *);
116 #else /* defined(VMEM_SANITY) */
117 #define vmem_check(vm)	/* nothing */
118 #endif /* defined(VMEM_SANITY) */
119 
120 #define	VMEM_HASHSIZE_MIN	1	/* XXX */
121 #define	VMEM_HASHSIZE_MAX	65536	/* XXX */
122 #define	VMEM_HASHSIZE_INIT	1
123 
124 #define	VM_FITMASK	(VM_BESTFIT | VM_INSTANTFIT)
125 
126 #if defined(_KERNEL)
127 static bool vmem_bootstrapped = false;
128 static kmutex_t vmem_list_lock;
129 static LIST_HEAD(, vmem) vmem_list = LIST_HEAD_INITIALIZER(vmem_list);
130 #endif /* defined(_KERNEL) */
131 
132 /* ---- misc */
133 
134 #define	VMEM_LOCK(vm)		mutex_enter(&vm->vm_lock)
135 #define	VMEM_TRYLOCK(vm)	mutex_tryenter(&vm->vm_lock)
136 #define	VMEM_UNLOCK(vm)		mutex_exit(&vm->vm_lock)
137 #define	VMEM_LOCK_INIT(vm, ipl)	mutex_init(&vm->vm_lock, MUTEX_DEFAULT, ipl)
138 #define	VMEM_LOCK_DESTROY(vm)	mutex_destroy(&vm->vm_lock)
139 #define	VMEM_ASSERT_LOCKED(vm)	KASSERT(mutex_owned(&vm->vm_lock))
140 
141 #define	VMEM_ALIGNUP(addr, align) \
142 	(-(-(addr) & -(align)))
143 
144 #define	VMEM_CROSS_P(addr1, addr2, boundary) \
145 	((((addr1) ^ (addr2)) & -(boundary)) != 0)
146 
147 #define	ORDER2SIZE(order)	((vmem_size_t)1 << (order))
148 #define	SIZE2ORDER(size)	((int)ilog2(size))
149 
150 #if !defined(_KERNEL)
151 #define	xmalloc(sz, flags)	malloc(sz)
152 #define	xfree(p, sz)		free(p)
153 #define	bt_alloc(vm, flags)	malloc(sizeof(bt_t))
154 #define	bt_free(vm, bt)		free(bt)
155 #else /* defined(_KERNEL) */
156 
157 #define	xmalloc(sz, flags) \
158     kmem_alloc(sz, ((flags) & VM_SLEEP) ? KM_SLEEP : KM_NOSLEEP);
159 #define	xfree(p, sz)		kmem_free(p, sz);
160 
161 /*
162  * BT_RESERVE calculation:
163  * we allocate memory for boundry tags with vmem, therefor we have
164  * to keep a reserve of bts used to allocated memory for bts.
165  * This reserve is 4 for each arena involved in allocating vmems memory.
166  * BT_MAXFREE: don't cache excessive counts of bts in arenas
167  */
168 #define STATIC_BT_COUNT 200
169 #define BT_MINRESERVE 4
170 #define BT_MAXFREE 64
171 
172 static struct vmem_btag static_bts[STATIC_BT_COUNT];
173 static int static_bt_count = STATIC_BT_COUNT;
174 
175 static struct vmem kmem_va_meta_arena_store;
176 vmem_t *kmem_va_meta_arena;
177 static struct vmem kmem_meta_arena_store;
178 vmem_t *kmem_meta_arena;
179 
180 static kmutex_t vmem_refill_lock;
181 static kmutex_t vmem_btag_lock;
182 static LIST_HEAD(, vmem_btag) vmem_btag_freelist;
183 static size_t vmem_btag_freelist_count = 0;
184 static size_t vmem_btag_count = STATIC_BT_COUNT;
185 
186 /* ---- boundary tag */
187 
188 #define	BT_PER_PAGE	(PAGE_SIZE / sizeof(bt_t))
189 
190 static int bt_refill(vmem_t *vm, vm_flag_t flags);
191 
192 static int
193 bt_refillglobal(vm_flag_t flags)
194 {
195 	vmem_addr_t va;
196 	bt_t *btp;
197 	bt_t *bt;
198 	int i;
199 
200 	mutex_enter(&vmem_refill_lock);
201 
202 	mutex_enter(&vmem_btag_lock);
203 	if (vmem_btag_freelist_count > 0) {
204 		mutex_exit(&vmem_btag_lock);
205 		mutex_exit(&vmem_refill_lock);
206 		return 0;
207 	}
208 	mutex_exit(&vmem_btag_lock);
209 
210 	if (vmem_alloc(kmem_meta_arena, PAGE_SIZE,
211 	    (flags & ~VM_FITMASK) | VM_INSTANTFIT | VM_POPULATING, &va) != 0) {
212 		mutex_exit(&vmem_refill_lock);
213 		return ENOMEM;
214 	}
215 	VMEM_EVCNT_INCR(bt_pages);
216 
217 	mutex_enter(&vmem_btag_lock);
218 	btp = (void *) va;
219 	for (i = 0; i < (BT_PER_PAGE); i++) {
220 		bt = btp;
221 		memset(bt, 0, sizeof(*bt));
222 		LIST_INSERT_HEAD(&vmem_btag_freelist, bt,
223 		    bt_freelist);
224 		vmem_btag_freelist_count++;
225 		vmem_btag_count++;
226 		VMEM_EVCNT_INCR(bt_count);
227 		btp++;
228 	}
229 	mutex_exit(&vmem_btag_lock);
230 
231 	bt_refill(kmem_arena, (flags & ~VM_FITMASK)
232 	    | VM_INSTANTFIT | VM_POPULATING);
233 	bt_refill(kmem_va_meta_arena, (flags & ~VM_FITMASK)
234 	    | VM_INSTANTFIT | VM_POPULATING);
235 	bt_refill(kmem_meta_arena, (flags & ~VM_FITMASK)
236 	    | VM_INSTANTFIT | VM_POPULATING);
237 
238 	mutex_exit(&vmem_refill_lock);
239 
240 	return 0;
241 }
242 
243 static int
244 bt_refill(vmem_t *vm, vm_flag_t flags)
245 {
246 	bt_t *bt;
247 
248 	if (!(flags & VM_POPULATING)) {
249 		bt_refillglobal(flags);
250 	}
251 
252 	VMEM_LOCK(vm);
253 	mutex_enter(&vmem_btag_lock);
254 	while (!LIST_EMPTY(&vmem_btag_freelist) &&
255 	    vm->vm_nfreetags <= BT_MINRESERVE) {
256 		bt = LIST_FIRST(&vmem_btag_freelist);
257 		LIST_REMOVE(bt, bt_freelist);
258 		LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
259 		vm->vm_nfreetags++;
260 		vmem_btag_freelist_count--;
261 	}
262 	mutex_exit(&vmem_btag_lock);
263 
264 	if (vm->vm_nfreetags == 0) {
265 		VMEM_UNLOCK(vm);
266 		return ENOMEM;
267 	}
268 	VMEM_UNLOCK(vm);
269 
270 	return 0;
271 }
272 
273 static inline bt_t *
274 bt_alloc(vmem_t *vm, vm_flag_t flags)
275 {
276 	bt_t *bt;
277 again:
278 	VMEM_LOCK(vm);
279 	if (vm->vm_nfreetags <= BT_MINRESERVE &&
280 	    (flags & VM_POPULATING) == 0) {
281 		VMEM_UNLOCK(vm);
282 		if (bt_refill(vm, VM_NOSLEEP | VM_INSTANTFIT)) {
283 			return NULL;
284 		}
285 		goto again;
286 	}
287 	bt = LIST_FIRST(&vm->vm_freetags);
288 	LIST_REMOVE(bt, bt_freelist);
289 	vm->vm_nfreetags--;
290 	VMEM_UNLOCK(vm);
291 	VMEM_EVCNT_INCR(bt_inuse);
292 
293 	return bt;
294 }
295 
296 static inline void
297 bt_free(vmem_t *vm, bt_t *bt)
298 {
299 
300 	VMEM_LOCK(vm);
301 	LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
302 	vm->vm_nfreetags++;
303 	while (vm->vm_nfreetags > BT_MAXFREE) {
304 		bt = LIST_FIRST(&vm->vm_freetags);
305 		LIST_REMOVE(bt, bt_freelist);
306 		vm->vm_nfreetags--;
307 		mutex_enter(&vmem_btag_lock);
308 		LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
309 		vmem_btag_freelist_count++;
310 		mutex_exit(&vmem_btag_lock);
311 	}
312 	VMEM_UNLOCK(vm);
313 	VMEM_EVCNT_DECR(bt_inuse);
314 }
315 
316 #endif	/* defined(_KERNEL) */
317 
318 /*
319  * freelist[0] ... [1, 1]
320  * freelist[1] ... [2, 3]
321  * freelist[2] ... [4, 7]
322  * freelist[3] ... [8, 15]
323  *  :
324  * freelist[n] ... [(1 << n), (1 << (n + 1)) - 1]
325  *  :
326  */
327 
328 static struct vmem_freelist *
329 bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
330 {
331 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
332 	const int idx = SIZE2ORDER(qsize);
333 
334 	KASSERT(size != 0 && qsize != 0);
335 	KASSERT((size & vm->vm_quantum_mask) == 0);
336 	KASSERT(idx >= 0);
337 	KASSERT(idx < VMEM_MAXORDER);
338 
339 	return &vm->vm_freelist[idx];
340 }
341 
342 /*
343  * bt_freehead_toalloc: return the freelist for the given size and allocation
344  * strategy.
345  *
346  * for VM_INSTANTFIT, return the list in which any blocks are large enough
347  * for the requested size.  otherwise, return the list which can have blocks
348  * large enough for the requested size.
349  */
350 
351 static struct vmem_freelist *
352 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, vm_flag_t strat)
353 {
354 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
355 	int idx = SIZE2ORDER(qsize);
356 
357 	KASSERT(size != 0 && qsize != 0);
358 	KASSERT((size & vm->vm_quantum_mask) == 0);
359 
360 	if (strat == VM_INSTANTFIT && ORDER2SIZE(idx) != qsize) {
361 		idx++;
362 		/* check too large request? */
363 	}
364 	KASSERT(idx >= 0);
365 	KASSERT(idx < VMEM_MAXORDER);
366 
367 	return &vm->vm_freelist[idx];
368 }
369 
370 /* ---- boundary tag hash */
371 
372 static struct vmem_hashlist *
373 bt_hashhead(vmem_t *vm, vmem_addr_t addr)
374 {
375 	struct vmem_hashlist *list;
376 	unsigned int hash;
377 
378 	hash = hash32_buf(&addr, sizeof(addr), HASH32_BUF_INIT);
379 	list = &vm->vm_hashlist[hash % vm->vm_hashsize];
380 
381 	return list;
382 }
383 
384 static bt_t *
385 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
386 {
387 	struct vmem_hashlist *list;
388 	bt_t *bt;
389 
390 	list = bt_hashhead(vm, addr);
391 	LIST_FOREACH(bt, list, bt_hashlist) {
392 		if (bt->bt_start == addr) {
393 			break;
394 		}
395 	}
396 
397 	return bt;
398 }
399 
400 static void
401 bt_rembusy(vmem_t *vm, bt_t *bt)
402 {
403 
404 	KASSERT(vm->vm_nbusytag > 0);
405 	vm->vm_inuse -= bt->bt_size;
406 	vm->vm_nbusytag--;
407 	LIST_REMOVE(bt, bt_hashlist);
408 }
409 
410 static void
411 bt_insbusy(vmem_t *vm, bt_t *bt)
412 {
413 	struct vmem_hashlist *list;
414 
415 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
416 
417 	list = bt_hashhead(vm, bt->bt_start);
418 	LIST_INSERT_HEAD(list, bt, bt_hashlist);
419 	vm->vm_nbusytag++;
420 	vm->vm_inuse += bt->bt_size;
421 }
422 
423 /* ---- boundary tag list */
424 
425 static void
426 bt_remseg(vmem_t *vm, bt_t *bt)
427 {
428 
429 	CIRCLEQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
430 }
431 
432 static void
433 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
434 {
435 
436 	CIRCLEQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
437 }
438 
439 static void
440 bt_insseg_tail(vmem_t *vm, bt_t *bt)
441 {
442 
443 	CIRCLEQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
444 }
445 
446 static void
447 bt_remfree(vmem_t *vm, bt_t *bt)
448 {
449 
450 	KASSERT(bt->bt_type == BT_TYPE_FREE);
451 
452 	LIST_REMOVE(bt, bt_freelist);
453 }
454 
455 static void
456 bt_insfree(vmem_t *vm, bt_t *bt)
457 {
458 	struct vmem_freelist *list;
459 
460 	list = bt_freehead_tofree(vm, bt->bt_size);
461 	LIST_INSERT_HEAD(list, bt, bt_freelist);
462 }
463 
464 /* ---- vmem internal functions */
465 
466 #if defined(QCACHE)
467 static inline vm_flag_t
468 prf_to_vmf(int prflags)
469 {
470 	vm_flag_t vmflags;
471 
472 	KASSERT((prflags & ~(PR_LIMITFAIL | PR_WAITOK | PR_NOWAIT)) == 0);
473 	if ((prflags & PR_WAITOK) != 0) {
474 		vmflags = VM_SLEEP;
475 	} else {
476 		vmflags = VM_NOSLEEP;
477 	}
478 	return vmflags;
479 }
480 
481 static inline int
482 vmf_to_prf(vm_flag_t vmflags)
483 {
484 	int prflags;
485 
486 	if ((vmflags & VM_SLEEP) != 0) {
487 		prflags = PR_WAITOK;
488 	} else {
489 		prflags = PR_NOWAIT;
490 	}
491 	return prflags;
492 }
493 
494 static size_t
495 qc_poolpage_size(size_t qcache_max)
496 {
497 	int i;
498 
499 	for (i = 0; ORDER2SIZE(i) <= qcache_max * 3; i++) {
500 		/* nothing */
501 	}
502 	return ORDER2SIZE(i);
503 }
504 
505 static void *
506 qc_poolpage_alloc(struct pool *pool, int prflags)
507 {
508 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
509 	vmem_t *vm = qc->qc_vmem;
510 	vmem_addr_t addr;
511 
512 	if (vmem_alloc(vm, pool->pr_alloc->pa_pagesz,
513 	    prf_to_vmf(prflags) | VM_INSTANTFIT, &addr) != 0)
514 		return NULL;
515 	return (void *)addr;
516 }
517 
518 static void
519 qc_poolpage_free(struct pool *pool, void *addr)
520 {
521 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
522 	vmem_t *vm = qc->qc_vmem;
523 
524 	vmem_free(vm, (vmem_addr_t)addr, pool->pr_alloc->pa_pagesz);
525 }
526 
527 static void
528 qc_init(vmem_t *vm, size_t qcache_max, int ipl)
529 {
530 	qcache_t *prevqc;
531 	struct pool_allocator *pa;
532 	int qcache_idx_max;
533 	int i;
534 
535 	KASSERT((qcache_max & vm->vm_quantum_mask) == 0);
536 	if (qcache_max > (VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift)) {
537 		qcache_max = VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift;
538 	}
539 	vm->vm_qcache_max = qcache_max;
540 	pa = &vm->vm_qcache_allocator;
541 	memset(pa, 0, sizeof(*pa));
542 	pa->pa_alloc = qc_poolpage_alloc;
543 	pa->pa_free = qc_poolpage_free;
544 	pa->pa_pagesz = qc_poolpage_size(qcache_max);
545 
546 	qcache_idx_max = qcache_max >> vm->vm_quantum_shift;
547 	prevqc = NULL;
548 	for (i = qcache_idx_max; i > 0; i--) {
549 		qcache_t *qc = &vm->vm_qcache_store[i - 1];
550 		size_t size = i << vm->vm_quantum_shift;
551 		pool_cache_t pc;
552 
553 		qc->qc_vmem = vm;
554 		snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu",
555 		    vm->vm_name, size);
556 
557 		pc = pool_cache_init(size,
558 		    ORDER2SIZE(vm->vm_quantum_shift), 0,
559 		    PR_NOALIGN | PR_NOTOUCH | PR_RECURSIVE /* XXX */,
560 		    qc->qc_name, pa, ipl, NULL, NULL, NULL);
561 
562 		KASSERT(pc);
563 
564 		qc->qc_cache = pc;
565 		KASSERT(qc->qc_cache != NULL);	/* XXX */
566 		if (prevqc != NULL &&
567 		    qc->qc_cache->pc_pool.pr_itemsperpage ==
568 		    prevqc->qc_cache->pc_pool.pr_itemsperpage) {
569 			pool_cache_destroy(qc->qc_cache);
570 			vm->vm_qcache[i - 1] = prevqc;
571 			continue;
572 		}
573 		qc->qc_cache->pc_pool.pr_qcache = qc;
574 		vm->vm_qcache[i - 1] = qc;
575 		prevqc = qc;
576 	}
577 }
578 
579 static void
580 qc_destroy(vmem_t *vm)
581 {
582 	const qcache_t *prevqc;
583 	int i;
584 	int qcache_idx_max;
585 
586 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
587 	prevqc = NULL;
588 	for (i = 0; i < qcache_idx_max; i++) {
589 		qcache_t *qc = vm->vm_qcache[i];
590 
591 		if (prevqc == qc) {
592 			continue;
593 		}
594 		pool_cache_destroy(qc->qc_cache);
595 		prevqc = qc;
596 	}
597 }
598 #endif
599 
600 #if defined(_KERNEL)
601 static void
602 vmem_bootstrap(void)
603 {
604 
605 	mutex_init(&vmem_list_lock, MUTEX_DEFAULT, IPL_VM);
606 	mutex_init(&vmem_refill_lock, MUTEX_DEFAULT, IPL_VM);
607 	mutex_init(&vmem_btag_lock, MUTEX_DEFAULT, IPL_VM);
608 
609 	while (static_bt_count-- > 0) {
610 		bt_t *bt = &static_bts[static_bt_count];
611 		LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
612 		VMEM_EVCNT_INCR(bt_count);
613 		vmem_btag_freelist_count++;
614 	}
615 	vmem_bootstrapped = TRUE;
616 }
617 
618 void
619 vmem_subsystem_init(vmem_t *vm)
620 {
621 
622 	kmem_va_meta_arena = vmem_init(&kmem_va_meta_arena_store, "vmem-va",
623 	    0, 0, PAGE_SIZE, vmem_alloc, vmem_free, vm,
624 	    0, VM_NOSLEEP | VM_BOOTSTRAP | VM_LARGEIMPORT,
625 	    IPL_VM);
626 
627 	kmem_meta_arena = vmem_init(&kmem_meta_arena_store, "vmem-meta",
628 	    0, 0, PAGE_SIZE,
629 	    uvm_km_kmem_alloc, uvm_km_kmem_free, kmem_va_meta_arena,
630 	    0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM);
631 }
632 #endif /* defined(_KERNEL) */
633 
634 static int
635 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags,
636     int spanbttype)
637 {
638 	bt_t *btspan;
639 	bt_t *btfree;
640 
641 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
642 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
643 	KASSERT(spanbttype == BT_TYPE_SPAN ||
644 	    spanbttype == BT_TYPE_SPAN_STATIC);
645 
646 	btspan = bt_alloc(vm, flags);
647 	if (btspan == NULL) {
648 		return ENOMEM;
649 	}
650 	btfree = bt_alloc(vm, flags);
651 	if (btfree == NULL) {
652 		bt_free(vm, btspan);
653 		return ENOMEM;
654 	}
655 
656 	btspan->bt_type = spanbttype;
657 	btspan->bt_start = addr;
658 	btspan->bt_size = size;
659 
660 	btfree->bt_type = BT_TYPE_FREE;
661 	btfree->bt_start = addr;
662 	btfree->bt_size = size;
663 
664 	VMEM_LOCK(vm);
665 	bt_insseg_tail(vm, btspan);
666 	bt_insseg(vm, btfree, btspan);
667 	bt_insfree(vm, btfree);
668 	vm->vm_size += size;
669 	VMEM_UNLOCK(vm);
670 
671 	return 0;
672 }
673 
674 static void
675 vmem_destroy1(vmem_t *vm)
676 {
677 
678 #if defined(QCACHE)
679 	qc_destroy(vm);
680 #endif /* defined(QCACHE) */
681 	if (vm->vm_hashlist != NULL) {
682 		int i;
683 
684 		for (i = 0; i < vm->vm_hashsize; i++) {
685 			bt_t *bt;
686 
687 			while ((bt = LIST_FIRST(&vm->vm_hashlist[i])) != NULL) {
688 				KASSERT(bt->bt_type == BT_TYPE_SPAN_STATIC);
689 				bt_free(vm, bt);
690 			}
691 		}
692 		if (vm->vm_hashlist != &vm->vm_hash0) {
693 			xfree(vm->vm_hashlist,
694 			    sizeof(struct vmem_hashlist *) * vm->vm_hashsize);
695 		}
696 	}
697 
698 	while (vm->vm_nfreetags > 0) {
699 		bt_t *bt = LIST_FIRST(&vm->vm_freetags);
700 		LIST_REMOVE(bt, bt_freelist);
701 		vm->vm_nfreetags--;
702 		mutex_enter(&vmem_btag_lock);
703 #if defined (_KERNEL)
704 		LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
705 		vmem_btag_freelist_count++;
706 #endif /* defined(_KERNEL) */
707 		mutex_exit(&vmem_btag_lock);
708 	}
709 
710 	VMEM_CONDVAR_DESTROY(vm);
711 	VMEM_LOCK_DESTROY(vm);
712 	xfree(vm, sizeof(*vm));
713 }
714 
715 static int
716 vmem_import(vmem_t *vm, vmem_size_t size, vm_flag_t flags)
717 {
718 	vmem_addr_t addr;
719 	int rc;
720 
721 	if (vm->vm_importfn == NULL) {
722 		return EINVAL;
723 	}
724 
725 	if (vm->vm_flags & VM_LARGEIMPORT) {
726 		size *= 16;
727 	}
728 
729 	if (vm->vm_flags & VM_XIMPORT) {
730 		rc = ((vmem_ximport_t *)vm->vm_importfn)(vm->vm_arg, size,
731 		    &size, flags, &addr);
732 	} else {
733 		rc = (vm->vm_importfn)(vm->vm_arg, size, flags, &addr);
734 	}
735 	if (rc) {
736 		return ENOMEM;
737 	}
738 
739 	if (vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN) != 0) {
740 		(*vm->vm_releasefn)(vm->vm_arg, addr, size);
741 		return ENOMEM;
742 	}
743 
744 	return 0;
745 }
746 
747 static int
748 vmem_rehash(vmem_t *vm, size_t newhashsize, vm_flag_t flags)
749 {
750 	bt_t *bt;
751 	int i;
752 	struct vmem_hashlist *newhashlist;
753 	struct vmem_hashlist *oldhashlist;
754 	size_t oldhashsize;
755 
756 	KASSERT(newhashsize > 0);
757 
758 	newhashlist =
759 	    xmalloc(sizeof(struct vmem_hashlist *) * newhashsize, flags);
760 	if (newhashlist == NULL) {
761 		return ENOMEM;
762 	}
763 	for (i = 0; i < newhashsize; i++) {
764 		LIST_INIT(&newhashlist[i]);
765 	}
766 
767 	if (!VMEM_TRYLOCK(vm)) {
768 		xfree(newhashlist,
769 		    sizeof(struct vmem_hashlist *) * newhashsize);
770 		return EBUSY;
771 	}
772 	oldhashlist = vm->vm_hashlist;
773 	oldhashsize = vm->vm_hashsize;
774 	vm->vm_hashlist = newhashlist;
775 	vm->vm_hashsize = newhashsize;
776 	if (oldhashlist == NULL) {
777 		VMEM_UNLOCK(vm);
778 		return 0;
779 	}
780 	for (i = 0; i < oldhashsize; i++) {
781 		while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
782 			bt_rembusy(vm, bt); /* XXX */
783 			bt_insbusy(vm, bt);
784 		}
785 	}
786 	VMEM_UNLOCK(vm);
787 
788 	if (oldhashlist != &vm->vm_hash0) {
789 		xfree(oldhashlist,
790 		    sizeof(struct vmem_hashlist *) * oldhashsize);
791 	}
792 
793 	return 0;
794 }
795 
796 /*
797  * vmem_fit: check if a bt can satisfy the given restrictions.
798  *
799  * it's a caller's responsibility to ensure the region is big enough
800  * before calling us.
801  */
802 
803 static int
804 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align,
805     vmem_size_t phase, vmem_size_t nocross,
806     vmem_addr_t minaddr, vmem_addr_t maxaddr, vmem_addr_t *addrp)
807 {
808 	vmem_addr_t start;
809 	vmem_addr_t end;
810 
811 	KASSERT(size > 0);
812 	KASSERT(bt->bt_size >= size); /* caller's responsibility */
813 
814 	/*
815 	 * XXX assumption: vmem_addr_t and vmem_size_t are
816 	 * unsigned integer of the same size.
817 	 */
818 
819 	start = bt->bt_start;
820 	if (start < minaddr) {
821 		start = minaddr;
822 	}
823 	end = BT_END(bt);
824 	if (end > maxaddr) {
825 		end = maxaddr;
826 	}
827 	if (start > end) {
828 		return ENOMEM;
829 	}
830 
831 	start = VMEM_ALIGNUP(start - phase, align) + phase;
832 	if (start < bt->bt_start) {
833 		start += align;
834 	}
835 	if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
836 		KASSERT(align < nocross);
837 		start = VMEM_ALIGNUP(start - phase, nocross) + phase;
838 	}
839 	if (start <= end && end - start >= size - 1) {
840 		KASSERT((start & (align - 1)) == phase);
841 		KASSERT(!VMEM_CROSS_P(start, start + size - 1, nocross));
842 		KASSERT(minaddr <= start);
843 		KASSERT(maxaddr == 0 || start + size - 1 <= maxaddr);
844 		KASSERT(bt->bt_start <= start);
845 		KASSERT(BT_END(bt) - start >= size - 1);
846 		*addrp = start;
847 		return 0;
848 	}
849 	return ENOMEM;
850 }
851 
852 /* ---- vmem API */
853 
854 /*
855  * vmem_create_internal: creates a vmem arena.
856  */
857 
858 vmem_t *
859 vmem_init(vmem_t *vm, const char *name,
860     vmem_addr_t base, vmem_size_t size, vmem_size_t quantum,
861     vmem_import_t *importfn, vmem_release_t *releasefn,
862     vmem_t *arg, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
863 {
864 	int i;
865 
866 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
867 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
868 	KASSERT(quantum > 0);
869 
870 #if defined(_KERNEL)
871 	/* XXX: SMP, we get called early... */
872 	if (!vmem_bootstrapped) {
873 		vmem_bootstrap();
874 	}
875 #endif /* defined(_KERNEL) */
876 
877 	if (vm == NULL) {
878 		vm = xmalloc(sizeof(*vm), flags);
879 	}
880 	if (vm == NULL) {
881 		return NULL;
882 	}
883 
884 	VMEM_CONDVAR_INIT(vm, "vmem");
885 	VMEM_LOCK_INIT(vm, ipl);
886 	vm->vm_flags = flags;
887 	vm->vm_nfreetags = 0;
888 	LIST_INIT(&vm->vm_freetags);
889 	strlcpy(vm->vm_name, name, sizeof(vm->vm_name));
890 	vm->vm_quantum_mask = quantum - 1;
891 	vm->vm_quantum_shift = SIZE2ORDER(quantum);
892 	KASSERT(ORDER2SIZE(vm->vm_quantum_shift) == quantum);
893 	vm->vm_importfn = importfn;
894 	vm->vm_releasefn = releasefn;
895 	vm->vm_arg = arg;
896 	vm->vm_nbusytag = 0;
897 	vm->vm_size = 0;
898 	vm->vm_inuse = 0;
899 #if defined(QCACHE)
900 	qc_init(vm, qcache_max, ipl);
901 #endif /* defined(QCACHE) */
902 
903 	CIRCLEQ_INIT(&vm->vm_seglist);
904 	for (i = 0; i < VMEM_MAXORDER; i++) {
905 		LIST_INIT(&vm->vm_freelist[i]);
906 	}
907 	memset(&vm->vm_hash0, 0, sizeof(struct vmem_hashlist));
908 	vm->vm_hashsize = 1;
909 	vm->vm_hashlist = &vm->vm_hash0;
910 
911 	if (size != 0) {
912 		if (vmem_add(vm, base, size, flags) != 0) {
913 			vmem_destroy1(vm);
914 			return NULL;
915 		}
916 	}
917 
918 #if defined(_KERNEL)
919 	if (flags & VM_BOOTSTRAP) {
920 		bt_refill(vm, VM_NOSLEEP);
921 	}
922 
923 	mutex_enter(&vmem_list_lock);
924 	LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist);
925 	mutex_exit(&vmem_list_lock);
926 #endif /* defined(_KERNEL) */
927 
928 	return vm;
929 }
930 
931 
932 
933 /*
934  * vmem_create: create an arena.
935  *
936  * => must not be called from interrupt context.
937  */
938 
939 vmem_t *
940 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
941     vmem_size_t quantum, vmem_import_t *importfn, vmem_release_t *releasefn,
942     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
943 {
944 
945 	KASSERT((flags & (VM_XIMPORT)) == 0);
946 
947 	return vmem_init(NULL, name, base, size, quantum,
948 	    importfn, releasefn, source, qcache_max, flags, ipl);
949 }
950 
951 /*
952  * vmem_xcreate: create an arena takes alternative import func.
953  *
954  * => must not be called from interrupt context.
955  */
956 
957 vmem_t *
958 vmem_xcreate(const char *name, vmem_addr_t base, vmem_size_t size,
959     vmem_size_t quantum, vmem_ximport_t *importfn, vmem_release_t *releasefn,
960     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
961 {
962 
963 	KASSERT((flags & (VM_XIMPORT)) == 0);
964 
965 	return vmem_init(NULL, name, base, size, quantum,
966 	    (vmem_import_t *)importfn, releasefn, source,
967 	    qcache_max, flags | VM_XIMPORT, ipl);
968 }
969 
970 void
971 vmem_destroy(vmem_t *vm)
972 {
973 
974 #if defined(_KERNEL)
975 	mutex_enter(&vmem_list_lock);
976 	LIST_REMOVE(vm, vm_alllist);
977 	mutex_exit(&vmem_list_lock);
978 #endif /* defined(_KERNEL) */
979 
980 	vmem_destroy1(vm);
981 }
982 
983 vmem_size_t
984 vmem_roundup_size(vmem_t *vm, vmem_size_t size)
985 {
986 
987 	return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
988 }
989 
990 /*
991  * vmem_alloc:
992  *
993  * => caller must ensure appropriate spl,
994  *    if the arena can be accessed from interrupt context.
995  */
996 
997 int
998 vmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, vmem_addr_t *addrp)
999 {
1000 	const vm_flag_t strat __unused = flags & VM_FITMASK;
1001 
1002 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
1003 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
1004 
1005 	KASSERT(size > 0);
1006 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
1007 	if ((flags & VM_SLEEP) != 0) {
1008 		ASSERT_SLEEPABLE();
1009 	}
1010 
1011 #if defined(QCACHE)
1012 	if (size <= vm->vm_qcache_max) {
1013 		void *p;
1014 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1015 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1016 
1017 		p = pool_cache_get(qc->qc_cache, vmf_to_prf(flags));
1018 		if (addrp != NULL)
1019 			*addrp = (vmem_addr_t)p;
1020 		return (p == NULL) ? ENOMEM : 0;
1021 	}
1022 #endif /* defined(QCACHE) */
1023 
1024 	return vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
1025 	    flags, addrp);
1026 }
1027 
1028 int
1029 vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align,
1030     const vmem_size_t phase, const vmem_size_t nocross,
1031     const vmem_addr_t minaddr, const vmem_addr_t maxaddr, const vm_flag_t flags,
1032     vmem_addr_t *addrp)
1033 {
1034 	struct vmem_freelist *list;
1035 	struct vmem_freelist *first;
1036 	struct vmem_freelist *end;
1037 	bt_t *bt;
1038 	bt_t *btnew;
1039 	bt_t *btnew2;
1040 	const vmem_size_t size = vmem_roundup_size(vm, size0);
1041 	vm_flag_t strat = flags & VM_FITMASK;
1042 	vmem_addr_t start;
1043 	int rc;
1044 
1045 	KASSERT(size0 > 0);
1046 	KASSERT(size > 0);
1047 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
1048 	if ((flags & VM_SLEEP) != 0) {
1049 		ASSERT_SLEEPABLE();
1050 	}
1051 	KASSERT((align & vm->vm_quantum_mask) == 0);
1052 	KASSERT((align & (align - 1)) == 0);
1053 	KASSERT((phase & vm->vm_quantum_mask) == 0);
1054 	KASSERT((nocross & vm->vm_quantum_mask) == 0);
1055 	KASSERT((nocross & (nocross - 1)) == 0);
1056 	KASSERT((align == 0 && phase == 0) || phase < align);
1057 	KASSERT(nocross == 0 || nocross >= size);
1058 	KASSERT(minaddr <= maxaddr);
1059 	KASSERT(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
1060 
1061 	if (align == 0) {
1062 		align = vm->vm_quantum_mask + 1;
1063 	}
1064 
1065 	/*
1066 	 * allocate boundary tags before acquiring the vmem lock.
1067 	 */
1068 	btnew = bt_alloc(vm, flags);
1069 	if (btnew == NULL) {
1070 		return ENOMEM;
1071 	}
1072 	btnew2 = bt_alloc(vm, flags); /* XXX not necessary if no restrictions */
1073 	if (btnew2 == NULL) {
1074 		bt_free(vm, btnew);
1075 		return ENOMEM;
1076 	}
1077 
1078 	/*
1079 	 * choose a free block from which we allocate.
1080 	 */
1081 retry_strat:
1082 	first = bt_freehead_toalloc(vm, size, strat);
1083 	end = &vm->vm_freelist[VMEM_MAXORDER];
1084 retry:
1085 	bt = NULL;
1086 	VMEM_LOCK(vm);
1087 	vmem_check(vm);
1088 	if (strat == VM_INSTANTFIT) {
1089 		/*
1090 		 * just choose the first block which satisfies our restrictions.
1091 		 *
1092 		 * note that we don't need to check the size of the blocks
1093 		 * because any blocks found on these list should be larger than
1094 		 * the given size.
1095 		 */
1096 		for (list = first; list < end; list++) {
1097 			bt = LIST_FIRST(list);
1098 			if (bt != NULL) {
1099 				rc = vmem_fit(bt, size, align, phase,
1100 				    nocross, minaddr, maxaddr, &start);
1101 				if (rc == 0) {
1102 					goto gotit;
1103 				}
1104 				/*
1105 				 * don't bother to follow the bt_freelist link
1106 				 * here.  the list can be very long and we are
1107 				 * told to run fast.  blocks from the later free
1108 				 * lists are larger and have better chances to
1109 				 * satisfy our restrictions.
1110 				 */
1111 			}
1112 		}
1113 	} else { /* VM_BESTFIT */
1114 		/*
1115 		 * we assume that, for space efficiency, it's better to
1116 		 * allocate from a smaller block.  thus we will start searching
1117 		 * from the lower-order list than VM_INSTANTFIT.
1118 		 * however, don't bother to find the smallest block in a free
1119 		 * list because the list can be very long.  we can revisit it
1120 		 * if/when it turns out to be a problem.
1121 		 *
1122 		 * note that the 'first' list can contain blocks smaller than
1123 		 * the requested size.  thus we need to check bt_size.
1124 		 */
1125 		for (list = first; list < end; list++) {
1126 			LIST_FOREACH(bt, list, bt_freelist) {
1127 				if (bt->bt_size >= size) {
1128 					rc = vmem_fit(bt, size, align, phase,
1129 					    nocross, minaddr, maxaddr, &start);
1130 					if (rc == 0) {
1131 						goto gotit;
1132 					}
1133 				}
1134 			}
1135 		}
1136 	}
1137 	VMEM_UNLOCK(vm);
1138 #if 1
1139 	if (strat == VM_INSTANTFIT) {
1140 		strat = VM_BESTFIT;
1141 		goto retry_strat;
1142 	}
1143 #endif
1144 	if (align != vm->vm_quantum_mask + 1 || phase != 0 || nocross != 0) {
1145 
1146 		/*
1147 		 * XXX should try to import a region large enough to
1148 		 * satisfy restrictions?
1149 		 */
1150 
1151 		goto fail;
1152 	}
1153 	/* XXX eeek, minaddr & maxaddr not respected */
1154 	if (vmem_import(vm, size, flags) == 0) {
1155 		goto retry;
1156 	}
1157 	/* XXX */
1158 
1159 	if ((flags & VM_SLEEP) != 0) {
1160 #if defined(_KERNEL) && !defined(_RUMPKERNEL)
1161 		mutex_spin_enter(&uvm_fpageqlock);
1162 		uvm_kick_pdaemon();
1163 		mutex_spin_exit(&uvm_fpageqlock);
1164 #endif
1165 		VMEM_LOCK(vm);
1166 		VMEM_CONDVAR_WAIT(vm);
1167 		VMEM_UNLOCK(vm);
1168 		goto retry;
1169 	}
1170 fail:
1171 	bt_free(vm, btnew);
1172 	bt_free(vm, btnew2);
1173 	return ENOMEM;
1174 
1175 gotit:
1176 	KASSERT(bt->bt_type == BT_TYPE_FREE);
1177 	KASSERT(bt->bt_size >= size);
1178 	bt_remfree(vm, bt);
1179 	vmem_check(vm);
1180 	if (bt->bt_start != start) {
1181 		btnew2->bt_type = BT_TYPE_FREE;
1182 		btnew2->bt_start = bt->bt_start;
1183 		btnew2->bt_size = start - bt->bt_start;
1184 		bt->bt_start = start;
1185 		bt->bt_size -= btnew2->bt_size;
1186 		bt_insfree(vm, btnew2);
1187 		bt_insseg(vm, btnew2, CIRCLEQ_PREV(bt, bt_seglist));
1188 		btnew2 = NULL;
1189 		vmem_check(vm);
1190 	}
1191 	KASSERT(bt->bt_start == start);
1192 	if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
1193 		/* split */
1194 		btnew->bt_type = BT_TYPE_BUSY;
1195 		btnew->bt_start = bt->bt_start;
1196 		btnew->bt_size = size;
1197 		bt->bt_start = bt->bt_start + size;
1198 		bt->bt_size -= size;
1199 		bt_insfree(vm, bt);
1200 		bt_insseg(vm, btnew, CIRCLEQ_PREV(bt, bt_seglist));
1201 		bt_insbusy(vm, btnew);
1202 		vmem_check(vm);
1203 		VMEM_UNLOCK(vm);
1204 	} else {
1205 		bt->bt_type = BT_TYPE_BUSY;
1206 		bt_insbusy(vm, bt);
1207 		vmem_check(vm);
1208 		VMEM_UNLOCK(vm);
1209 		bt_free(vm, btnew);
1210 		btnew = bt;
1211 	}
1212 	if (btnew2 != NULL) {
1213 		bt_free(vm, btnew2);
1214 	}
1215 	KASSERT(btnew->bt_size >= size);
1216 	btnew->bt_type = BT_TYPE_BUSY;
1217 
1218 	if (addrp != NULL)
1219 		*addrp = btnew->bt_start;
1220 	return 0;
1221 }
1222 
1223 /*
1224  * vmem_free:
1225  *
1226  * => caller must ensure appropriate spl,
1227  *    if the arena can be accessed from interrupt context.
1228  */
1229 
1230 void
1231 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1232 {
1233 
1234 	KASSERT(size > 0);
1235 
1236 #if defined(QCACHE)
1237 	if (size <= vm->vm_qcache_max) {
1238 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1239 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1240 
1241 		pool_cache_put(qc->qc_cache, (void *)addr);
1242 		return;
1243 	}
1244 #endif /* defined(QCACHE) */
1245 
1246 	vmem_xfree(vm, addr, size);
1247 }
1248 
1249 void
1250 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1251 {
1252 	bt_t *bt;
1253 	bt_t *t;
1254 	LIST_HEAD(, vmem_btag) tofree;
1255 
1256 	LIST_INIT(&tofree);
1257 
1258 	KASSERT(size > 0);
1259 
1260 	VMEM_LOCK(vm);
1261 
1262 	bt = bt_lookupbusy(vm, addr);
1263 	KASSERT(bt != NULL);
1264 	KASSERT(bt->bt_start == addr);
1265 	KASSERT(bt->bt_size == vmem_roundup_size(vm, size) ||
1266 	    bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
1267 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
1268 	bt_rembusy(vm, bt);
1269 	bt->bt_type = BT_TYPE_FREE;
1270 
1271 	/* coalesce */
1272 	t = CIRCLEQ_NEXT(bt, bt_seglist);
1273 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1274 		KASSERT(BT_END(bt) < t->bt_start);	/* YYY */
1275 		bt_remfree(vm, t);
1276 		bt_remseg(vm, t);
1277 		bt->bt_size += t->bt_size;
1278 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1279 	}
1280 	t = CIRCLEQ_PREV(bt, bt_seglist);
1281 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1282 		KASSERT(BT_END(t) < bt->bt_start);	/* YYY */
1283 		bt_remfree(vm, t);
1284 		bt_remseg(vm, t);
1285 		bt->bt_size += t->bt_size;
1286 		bt->bt_start = t->bt_start;
1287 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1288 	}
1289 
1290 	t = CIRCLEQ_PREV(bt, bt_seglist);
1291 	KASSERT(t != NULL);
1292 	KASSERT(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY);
1293 	if (vm->vm_releasefn != NULL && t->bt_type == BT_TYPE_SPAN &&
1294 	    t->bt_size == bt->bt_size) {
1295 		vmem_addr_t spanaddr;
1296 		vmem_size_t spansize;
1297 
1298 		KASSERT(t->bt_start == bt->bt_start);
1299 		spanaddr = bt->bt_start;
1300 		spansize = bt->bt_size;
1301 		bt_remseg(vm, bt);
1302 		LIST_INSERT_HEAD(&tofree, bt, bt_freelist);
1303 		bt_remseg(vm, t);
1304 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1305 		vm->vm_size -= spansize;
1306 		VMEM_CONDVAR_BROADCAST(vm);
1307 		VMEM_UNLOCK(vm);
1308 		(*vm->vm_releasefn)(vm->vm_arg, spanaddr, spansize);
1309 	} else {
1310 		bt_insfree(vm, bt);
1311 		VMEM_CONDVAR_BROADCAST(vm);
1312 		VMEM_UNLOCK(vm);
1313 	}
1314 
1315 	while (!LIST_EMPTY(&tofree)) {
1316 		t = LIST_FIRST(&tofree);
1317 		LIST_REMOVE(t, bt_freelist);
1318 		bt_free(vm, t);
1319 	}
1320 }
1321 
1322 /*
1323  * vmem_add:
1324  *
1325  * => caller must ensure appropriate spl,
1326  *    if the arena can be accessed from interrupt context.
1327  */
1328 
1329 int
1330 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags)
1331 {
1332 
1333 	return vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN_STATIC);
1334 }
1335 
1336 /*
1337  * vmem_size: information about arenas size
1338  *
1339  * => return free/allocated size in arena
1340  */
1341 vmem_size_t
1342 vmem_size(vmem_t *vm, int typemask)
1343 {
1344 
1345 	switch (typemask) {
1346 	case VMEM_ALLOC:
1347 		return vm->vm_inuse;
1348 	case VMEM_FREE:
1349 		return vm->vm_size - vm->vm_inuse;
1350 	case VMEM_FREE|VMEM_ALLOC:
1351 		return vm->vm_size;
1352 	default:
1353 		panic("vmem_size");
1354 	}
1355 }
1356 
1357 /* ---- rehash */
1358 
1359 #if defined(_KERNEL)
1360 static struct callout vmem_rehash_ch;
1361 static int vmem_rehash_interval;
1362 static struct workqueue *vmem_rehash_wq;
1363 static struct work vmem_rehash_wk;
1364 
1365 static void
1366 vmem_rehash_all(struct work *wk, void *dummy)
1367 {
1368 	vmem_t *vm;
1369 
1370 	KASSERT(wk == &vmem_rehash_wk);
1371 	mutex_enter(&vmem_list_lock);
1372 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1373 		size_t desired;
1374 		size_t current;
1375 
1376 		if (!VMEM_TRYLOCK(vm)) {
1377 			continue;
1378 		}
1379 		desired = vm->vm_nbusytag;
1380 		current = vm->vm_hashsize;
1381 		VMEM_UNLOCK(vm);
1382 
1383 		if (desired > VMEM_HASHSIZE_MAX) {
1384 			desired = VMEM_HASHSIZE_MAX;
1385 		} else if (desired < VMEM_HASHSIZE_MIN) {
1386 			desired = VMEM_HASHSIZE_MIN;
1387 		}
1388 		if (desired > current * 2 || desired * 2 < current) {
1389 			vmem_rehash(vm, desired, VM_NOSLEEP);
1390 		}
1391 	}
1392 	mutex_exit(&vmem_list_lock);
1393 
1394 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1395 }
1396 
1397 static void
1398 vmem_rehash_all_kick(void *dummy)
1399 {
1400 
1401 	workqueue_enqueue(vmem_rehash_wq, &vmem_rehash_wk, NULL);
1402 }
1403 
1404 void
1405 vmem_rehash_start(void)
1406 {
1407 	int error;
1408 
1409 	error = workqueue_create(&vmem_rehash_wq, "vmem_rehash",
1410 	    vmem_rehash_all, NULL, PRI_VM, IPL_SOFTCLOCK, WQ_MPSAFE);
1411 	if (error) {
1412 		panic("%s: workqueue_create %d\n", __func__, error);
1413 	}
1414 	callout_init(&vmem_rehash_ch, CALLOUT_MPSAFE);
1415 	callout_setfunc(&vmem_rehash_ch, vmem_rehash_all_kick, NULL);
1416 
1417 	vmem_rehash_interval = hz * 10;
1418 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1419 }
1420 #endif /* defined(_KERNEL) */
1421 
1422 /* ---- debug */
1423 
1424 #if defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY)
1425 
1426 static void bt_dump(const bt_t *, void (*)(const char *, ...)
1427     __printflike(1, 2));
1428 
1429 static const char *
1430 bt_type_string(int type)
1431 {
1432 	static const char * const table[] = {
1433 		[BT_TYPE_BUSY] = "busy",
1434 		[BT_TYPE_FREE] = "free",
1435 		[BT_TYPE_SPAN] = "span",
1436 		[BT_TYPE_SPAN_STATIC] = "static span",
1437 	};
1438 
1439 	if (type >= __arraycount(table)) {
1440 		return "BOGUS";
1441 	}
1442 	return table[type];
1443 }
1444 
1445 static void
1446 bt_dump(const bt_t *bt, void (*pr)(const char *, ...))
1447 {
1448 
1449 	(*pr)("\t%p: %" PRIu64 ", %" PRIu64 ", %d(%s)\n",
1450 	    bt, (uint64_t)bt->bt_start, (uint64_t)bt->bt_size,
1451 	    bt->bt_type, bt_type_string(bt->bt_type));
1452 }
1453 
1454 static void
1455 vmem_dump(const vmem_t *vm , void (*pr)(const char *, ...) __printflike(1, 2))
1456 {
1457 	const bt_t *bt;
1458 	int i;
1459 
1460 	(*pr)("vmem %p '%s'\n", vm, vm->vm_name);
1461 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1462 		bt_dump(bt, pr);
1463 	}
1464 
1465 	for (i = 0; i < VMEM_MAXORDER; i++) {
1466 		const struct vmem_freelist *fl = &vm->vm_freelist[i];
1467 
1468 		if (LIST_EMPTY(fl)) {
1469 			continue;
1470 		}
1471 
1472 		(*pr)("freelist[%d]\n", i);
1473 		LIST_FOREACH(bt, fl, bt_freelist) {
1474 			bt_dump(bt, pr);
1475 		}
1476 	}
1477 }
1478 
1479 #endif /* defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY) */
1480 
1481 #if defined(DDB)
1482 static bt_t *
1483 vmem_whatis_lookup(vmem_t *vm, uintptr_t addr)
1484 {
1485 	bt_t *bt;
1486 
1487 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1488 		if (BT_ISSPAN_P(bt)) {
1489 			continue;
1490 		}
1491 		if (bt->bt_start <= addr && addr <= BT_END(bt)) {
1492 			return bt;
1493 		}
1494 	}
1495 
1496 	return NULL;
1497 }
1498 
1499 void
1500 vmem_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1501 {
1502 	vmem_t *vm;
1503 
1504 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1505 		bt_t *bt;
1506 
1507 		bt = vmem_whatis_lookup(vm, addr);
1508 		if (bt == NULL) {
1509 			continue;
1510 		}
1511 		(*pr)("%p is %p+%zu in VMEM '%s' (%s)\n",
1512 		    (void *)addr, (void *)bt->bt_start,
1513 		    (size_t)(addr - bt->bt_start), vm->vm_name,
1514 		    (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free");
1515 	}
1516 }
1517 
1518 void
1519 vmem_printall(const char *modif, void (*pr)(const char *, ...))
1520 {
1521 	const vmem_t *vm;
1522 
1523 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1524 		vmem_dump(vm, pr);
1525 	}
1526 }
1527 
1528 void
1529 vmem_print(uintptr_t addr, const char *modif, void (*pr)(const char *, ...))
1530 {
1531 	const vmem_t *vm = (const void *)addr;
1532 
1533 	vmem_dump(vm, pr);
1534 }
1535 #endif /* defined(DDB) */
1536 
1537 #if defined(_KERNEL)
1538 #define vmem_printf printf
1539 #else
1540 #include <stdio.h>
1541 #include <stdarg.h>
1542 
1543 static void
1544 vmem_printf(const char *fmt, ...)
1545 {
1546 	va_list ap;
1547 	va_start(ap, fmt);
1548 	vprintf(fmt, ap);
1549 	va_end(ap);
1550 }
1551 #endif
1552 
1553 #if defined(VMEM_SANITY)
1554 
1555 static bool
1556 vmem_check_sanity(vmem_t *vm)
1557 {
1558 	const bt_t *bt, *bt2;
1559 
1560 	KASSERT(vm != NULL);
1561 
1562 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1563 		if (bt->bt_start > BT_END(bt)) {
1564 			printf("corrupted tag\n");
1565 			bt_dump(bt, vmem_printf);
1566 			return false;
1567 		}
1568 	}
1569 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1570 		CIRCLEQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) {
1571 			if (bt == bt2) {
1572 				continue;
1573 			}
1574 			if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) {
1575 				continue;
1576 			}
1577 			if (bt->bt_start <= BT_END(bt2) &&
1578 			    bt2->bt_start <= BT_END(bt)) {
1579 				printf("overwrapped tags\n");
1580 				bt_dump(bt, vmem_printf);
1581 				bt_dump(bt2, vmem_printf);
1582 				return false;
1583 			}
1584 		}
1585 	}
1586 
1587 	return true;
1588 }
1589 
1590 static void
1591 vmem_check(vmem_t *vm)
1592 {
1593 
1594 	if (!vmem_check_sanity(vm)) {
1595 		panic("insanity vmem %p", vm);
1596 	}
1597 }
1598 
1599 #endif /* defined(VMEM_SANITY) */
1600 
1601 #if defined(UNITTEST)
1602 int
1603 main(void)
1604 {
1605 	int rc;
1606 	vmem_t *vm;
1607 	vmem_addr_t p;
1608 	struct reg {
1609 		vmem_addr_t p;
1610 		vmem_size_t sz;
1611 		bool x;
1612 	} *reg = NULL;
1613 	int nreg = 0;
1614 	int nalloc = 0;
1615 	int nfree = 0;
1616 	vmem_size_t total = 0;
1617 #if 1
1618 	vm_flag_t strat = VM_INSTANTFIT;
1619 #else
1620 	vm_flag_t strat = VM_BESTFIT;
1621 #endif
1622 
1623 	vm = vmem_create("test", 0, 0, 1, NULL, NULL, NULL, 0, VM_SLEEP,
1624 #ifdef _KERNEL
1625 	    IPL_NONE
1626 #else
1627 	    0
1628 #endif
1629 	    );
1630 	if (vm == NULL) {
1631 		printf("vmem_create\n");
1632 		exit(EXIT_FAILURE);
1633 	}
1634 	vmem_dump(vm, vmem_printf);
1635 
1636 	rc = vmem_add(vm, 0, 50, VM_SLEEP);
1637 	assert(rc == 0);
1638 	rc = vmem_add(vm, 100, 200, VM_SLEEP);
1639 	assert(rc == 0);
1640 	rc = vmem_add(vm, 2000, 1, VM_SLEEP);
1641 	assert(rc == 0);
1642 	rc = vmem_add(vm, 40000, 65536, VM_SLEEP);
1643 	assert(rc == 0);
1644 	rc = vmem_add(vm, 10000, 10000, VM_SLEEP);
1645 	assert(rc == 0);
1646 	rc = vmem_add(vm, 500, 1000, VM_SLEEP);
1647 	assert(rc == 0);
1648 	rc = vmem_add(vm, 0xffffff00, 0x100, VM_SLEEP);
1649 	assert(rc == 0);
1650 	rc = vmem_xalloc(vm, 0x101, 0, 0, 0,
1651 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1652 	assert(rc != 0);
1653 	rc = vmem_xalloc(vm, 50, 0, 0, 0, 0, 49, strat|VM_SLEEP, &p);
1654 	assert(rc == 0 && p == 0);
1655 	vmem_xfree(vm, p, 50);
1656 	rc = vmem_xalloc(vm, 25, 0, 0, 0, 0, 24, strat|VM_SLEEP, &p);
1657 	assert(rc == 0 && p == 0);
1658 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1659 	    0xffffff01, 0xffffffff, strat|VM_SLEEP, &p);
1660 	assert(rc != 0);
1661 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1662 	    0xffffff00, 0xfffffffe, strat|VM_SLEEP, &p);
1663 	assert(rc != 0);
1664 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1665 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1666 	assert(rc == 0);
1667 	vmem_dump(vm, vmem_printf);
1668 	for (;;) {
1669 		struct reg *r;
1670 		int t = rand() % 100;
1671 
1672 		if (t > 45) {
1673 			/* alloc */
1674 			vmem_size_t sz = rand() % 500 + 1;
1675 			bool x;
1676 			vmem_size_t align, phase, nocross;
1677 			vmem_addr_t minaddr, maxaddr;
1678 
1679 			if (t > 70) {
1680 				x = true;
1681 				/* XXX */
1682 				align = 1 << (rand() % 15);
1683 				phase = rand() % 65536;
1684 				nocross = 1 << (rand() % 15);
1685 				if (align <= phase) {
1686 					phase = 0;
1687 				}
1688 				if (VMEM_CROSS_P(phase, phase + sz - 1,
1689 				    nocross)) {
1690 					nocross = 0;
1691 				}
1692 				do {
1693 					minaddr = rand() % 50000;
1694 					maxaddr = rand() % 70000;
1695 				} while (minaddr > maxaddr);
1696 				printf("=== xalloc %" PRIu64
1697 				    " align=%" PRIu64 ", phase=%" PRIu64
1698 				    ", nocross=%" PRIu64 ", min=%" PRIu64
1699 				    ", max=%" PRIu64 "\n",
1700 				    (uint64_t)sz,
1701 				    (uint64_t)align,
1702 				    (uint64_t)phase,
1703 				    (uint64_t)nocross,
1704 				    (uint64_t)minaddr,
1705 				    (uint64_t)maxaddr);
1706 				rc = vmem_xalloc(vm, sz, align, phase, nocross,
1707 				    minaddr, maxaddr, strat|VM_SLEEP, &p);
1708 			} else {
1709 				x = false;
1710 				printf("=== alloc %" PRIu64 "\n", (uint64_t)sz);
1711 				rc = vmem_alloc(vm, sz, strat|VM_SLEEP, &p);
1712 			}
1713 			printf("-> %" PRIu64 "\n", (uint64_t)p);
1714 			vmem_dump(vm, vmem_printf);
1715 			if (rc != 0) {
1716 				if (x) {
1717 					continue;
1718 				}
1719 				break;
1720 			}
1721 			nreg++;
1722 			reg = realloc(reg, sizeof(*reg) * nreg);
1723 			r = &reg[nreg - 1];
1724 			r->p = p;
1725 			r->sz = sz;
1726 			r->x = x;
1727 			total += sz;
1728 			nalloc++;
1729 		} else if (nreg != 0) {
1730 			/* free */
1731 			r = &reg[rand() % nreg];
1732 			printf("=== free %" PRIu64 ", %" PRIu64 "\n",
1733 			    (uint64_t)r->p, (uint64_t)r->sz);
1734 			if (r->x) {
1735 				vmem_xfree(vm, r->p, r->sz);
1736 			} else {
1737 				vmem_free(vm, r->p, r->sz);
1738 			}
1739 			total -= r->sz;
1740 			vmem_dump(vm, vmem_printf);
1741 			*r = reg[nreg - 1];
1742 			nreg--;
1743 			nfree++;
1744 		}
1745 		printf("total=%" PRIu64 "\n", (uint64_t)total);
1746 	}
1747 	fprintf(stderr, "total=%" PRIu64 ", nalloc=%d, nfree=%d\n",
1748 	    (uint64_t)total, nalloc, nfree);
1749 	exit(EXIT_SUCCESS);
1750 }
1751 #endif /* defined(UNITTEST) */
1752