xref: /netbsd-src/sys/kern/subr_vmem.c (revision 96fc3e30a7c3f7bba53384bf41dad5f78306fac4)
1 /*	$NetBSD: subr_vmem.c,v 1.80 2013/01/29 21:26:24 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 
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: subr_vmem.c,v 1.80 2013/01/29 21:26:24 para 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 	} else {
208 		mutex_exit(&vmem_btag_lock);
209 	}
210 
211 	if (vmem_alloc(kmem_meta_arena, PAGE_SIZE,
212 	    (flags & ~VM_FITMASK) | VM_INSTANTFIT | VM_POPULATING, &va) != 0) {
213 		mutex_exit(&vmem_btag_lock);
214 		mutex_exit(&vmem_refill_lock);
215 		return ENOMEM;
216 	}
217 	VMEM_EVCNT_INCR(bt_pages);
218 
219 	mutex_enter(&vmem_btag_lock);
220 	btp = (void *) va;
221 	for (i = 0; i < (BT_PER_PAGE); i++) {
222 		bt = btp;
223 		memset(bt, 0, sizeof(*bt));
224 		LIST_INSERT_HEAD(&vmem_btag_freelist, bt,
225 		    bt_freelist);
226 		vmem_btag_freelist_count++;
227 		vmem_btag_count++;
228 		VMEM_EVCNT_INCR(bt_count);
229 		btp++;
230 	}
231 	mutex_exit(&vmem_btag_lock);
232 
233 	bt_refill(kmem_arena, (flags & ~VM_FITMASK)
234 	    | VM_INSTANTFIT | VM_POPULATING);
235 	bt_refill(kmem_va_meta_arena, (flags & ~VM_FITMASK)
236 	    | VM_INSTANTFIT | VM_POPULATING);
237 	bt_refill(kmem_meta_arena, (flags & ~VM_FITMASK)
238 	    | VM_INSTANTFIT | VM_POPULATING);
239 
240 	mutex_exit(&vmem_refill_lock);
241 
242 	return 0;
243 }
244 
245 static int
246 bt_refill(vmem_t *vm, vm_flag_t flags)
247 {
248 	bt_t *bt;
249 
250 	if (!(flags & VM_POPULATING)) {
251 		bt_refillglobal(flags);
252 	}
253 
254 	VMEM_LOCK(vm);
255 	mutex_enter(&vmem_btag_lock);
256 	while (!LIST_EMPTY(&vmem_btag_freelist) &&
257 	    vm->vm_nfreetags <= BT_MINRESERVE) {
258 		bt = LIST_FIRST(&vmem_btag_freelist);
259 		LIST_REMOVE(bt, bt_freelist);
260 		LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
261 		vm->vm_nfreetags++;
262 		vmem_btag_freelist_count--;
263 	}
264 	mutex_exit(&vmem_btag_lock);
265 
266 	if (vm->vm_nfreetags == 0) {
267 		VMEM_UNLOCK(vm);
268 		return ENOMEM;
269 	}
270 	VMEM_UNLOCK(vm);
271 
272 	return 0;
273 }
274 
275 static inline bt_t *
276 bt_alloc(vmem_t *vm, vm_flag_t flags)
277 {
278 	bt_t *bt;
279 again:
280 	VMEM_LOCK(vm);
281 	if (vm->vm_nfreetags <= BT_MINRESERVE &&
282 	    (flags & VM_POPULATING) == 0) {
283 		VMEM_UNLOCK(vm);
284 		if (bt_refill(vm, VM_NOSLEEP | VM_INSTANTFIT)) {
285 			return NULL;
286 		}
287 		goto again;
288 	}
289 	bt = LIST_FIRST(&vm->vm_freetags);
290 	LIST_REMOVE(bt, bt_freelist);
291 	vm->vm_nfreetags--;
292 	VMEM_UNLOCK(vm);
293 	VMEM_EVCNT_INCR(bt_inuse);
294 
295 	return bt;
296 }
297 
298 static inline void
299 bt_free(vmem_t *vm, bt_t *bt)
300 {
301 
302 	VMEM_LOCK(vm);
303 	LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
304 	vm->vm_nfreetags++;
305 	while (vm->vm_nfreetags > BT_MAXFREE) {
306 		bt = LIST_FIRST(&vm->vm_freetags);
307 		LIST_REMOVE(bt, bt_freelist);
308 		vm->vm_nfreetags--;
309 		mutex_enter(&vmem_btag_lock);
310 		LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
311 		vmem_btag_freelist_count++;
312 		mutex_exit(&vmem_btag_lock);
313 	}
314 	VMEM_UNLOCK(vm);
315 	VMEM_EVCNT_DECR(bt_inuse);
316 }
317 
318 #endif	/* defined(_KERNEL) */
319 
320 /*
321  * freelist[0] ... [1, 1]
322  * freelist[1] ... [2, 3]
323  * freelist[2] ... [4, 7]
324  * freelist[3] ... [8, 15]
325  *  :
326  * freelist[n] ... [(1 << n), (1 << (n + 1)) - 1]
327  *  :
328  */
329 
330 static struct vmem_freelist *
331 bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
332 {
333 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
334 	const int idx = SIZE2ORDER(qsize);
335 
336 	KASSERT(size != 0 && qsize != 0);
337 	KASSERT((size & vm->vm_quantum_mask) == 0);
338 	KASSERT(idx >= 0);
339 	KASSERT(idx < VMEM_MAXORDER);
340 
341 	return &vm->vm_freelist[idx];
342 }
343 
344 /*
345  * bt_freehead_toalloc: return the freelist for the given size and allocation
346  * strategy.
347  *
348  * for VM_INSTANTFIT, return the list in which any blocks are large enough
349  * for the requested size.  otherwise, return the list which can have blocks
350  * large enough for the requested size.
351  */
352 
353 static struct vmem_freelist *
354 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, vm_flag_t strat)
355 {
356 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
357 	int idx = SIZE2ORDER(qsize);
358 
359 	KASSERT(size != 0 && qsize != 0);
360 	KASSERT((size & vm->vm_quantum_mask) == 0);
361 
362 	if (strat == VM_INSTANTFIT && ORDER2SIZE(idx) != qsize) {
363 		idx++;
364 		/* check too large request? */
365 	}
366 	KASSERT(idx >= 0);
367 	KASSERT(idx < VMEM_MAXORDER);
368 
369 	return &vm->vm_freelist[idx];
370 }
371 
372 /* ---- boundary tag hash */
373 
374 static struct vmem_hashlist *
375 bt_hashhead(vmem_t *vm, vmem_addr_t addr)
376 {
377 	struct vmem_hashlist *list;
378 	unsigned int hash;
379 
380 	hash = hash32_buf(&addr, sizeof(addr), HASH32_BUF_INIT);
381 	list = &vm->vm_hashlist[hash % vm->vm_hashsize];
382 
383 	return list;
384 }
385 
386 static bt_t *
387 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
388 {
389 	struct vmem_hashlist *list;
390 	bt_t *bt;
391 
392 	list = bt_hashhead(vm, addr);
393 	LIST_FOREACH(bt, list, bt_hashlist) {
394 		if (bt->bt_start == addr) {
395 			break;
396 		}
397 	}
398 
399 	return bt;
400 }
401 
402 static void
403 bt_rembusy(vmem_t *vm, bt_t *bt)
404 {
405 
406 	KASSERT(vm->vm_nbusytag > 0);
407 	vm->vm_inuse -= bt->bt_size;
408 	vm->vm_nbusytag--;
409 	LIST_REMOVE(bt, bt_hashlist);
410 }
411 
412 static void
413 bt_insbusy(vmem_t *vm, bt_t *bt)
414 {
415 	struct vmem_hashlist *list;
416 
417 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
418 
419 	list = bt_hashhead(vm, bt->bt_start);
420 	LIST_INSERT_HEAD(list, bt, bt_hashlist);
421 	vm->vm_nbusytag++;
422 	vm->vm_inuse += bt->bt_size;
423 }
424 
425 /* ---- boundary tag list */
426 
427 static void
428 bt_remseg(vmem_t *vm, bt_t *bt)
429 {
430 
431 	CIRCLEQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
432 }
433 
434 static void
435 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
436 {
437 
438 	CIRCLEQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
439 }
440 
441 static void
442 bt_insseg_tail(vmem_t *vm, bt_t *bt)
443 {
444 
445 	CIRCLEQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
446 }
447 
448 static void
449 bt_remfree(vmem_t *vm, bt_t *bt)
450 {
451 
452 	KASSERT(bt->bt_type == BT_TYPE_FREE);
453 
454 	LIST_REMOVE(bt, bt_freelist);
455 }
456 
457 static void
458 bt_insfree(vmem_t *vm, bt_t *bt)
459 {
460 	struct vmem_freelist *list;
461 
462 	list = bt_freehead_tofree(vm, bt->bt_size);
463 	LIST_INSERT_HEAD(list, bt, bt_freelist);
464 }
465 
466 /* ---- vmem internal functions */
467 
468 #if defined(QCACHE)
469 static inline vm_flag_t
470 prf_to_vmf(int prflags)
471 {
472 	vm_flag_t vmflags;
473 
474 	KASSERT((prflags & ~(PR_LIMITFAIL | PR_WAITOK | PR_NOWAIT)) == 0);
475 	if ((prflags & PR_WAITOK) != 0) {
476 		vmflags = VM_SLEEP;
477 	} else {
478 		vmflags = VM_NOSLEEP;
479 	}
480 	return vmflags;
481 }
482 
483 static inline int
484 vmf_to_prf(vm_flag_t vmflags)
485 {
486 	int prflags;
487 
488 	if ((vmflags & VM_SLEEP) != 0) {
489 		prflags = PR_WAITOK;
490 	} else {
491 		prflags = PR_NOWAIT;
492 	}
493 	return prflags;
494 }
495 
496 static size_t
497 qc_poolpage_size(size_t qcache_max)
498 {
499 	int i;
500 
501 	for (i = 0; ORDER2SIZE(i) <= qcache_max * 3; i++) {
502 		/* nothing */
503 	}
504 	return ORDER2SIZE(i);
505 }
506 
507 static void *
508 qc_poolpage_alloc(struct pool *pool, int prflags)
509 {
510 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
511 	vmem_t *vm = qc->qc_vmem;
512 	vmem_addr_t addr;
513 
514 	if (vmem_alloc(vm, pool->pr_alloc->pa_pagesz,
515 	    prf_to_vmf(prflags) | VM_INSTANTFIT, &addr) != 0)
516 		return NULL;
517 	return (void *)addr;
518 }
519 
520 static void
521 qc_poolpage_free(struct pool *pool, void *addr)
522 {
523 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
524 	vmem_t *vm = qc->qc_vmem;
525 
526 	vmem_free(vm, (vmem_addr_t)addr, pool->pr_alloc->pa_pagesz);
527 }
528 
529 static void
530 qc_init(vmem_t *vm, size_t qcache_max, int ipl)
531 {
532 	qcache_t *prevqc;
533 	struct pool_allocator *pa;
534 	int qcache_idx_max;
535 	int i;
536 
537 	KASSERT((qcache_max & vm->vm_quantum_mask) == 0);
538 	if (qcache_max > (VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift)) {
539 		qcache_max = VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift;
540 	}
541 	vm->vm_qcache_max = qcache_max;
542 	pa = &vm->vm_qcache_allocator;
543 	memset(pa, 0, sizeof(*pa));
544 	pa->pa_alloc = qc_poolpage_alloc;
545 	pa->pa_free = qc_poolpage_free;
546 	pa->pa_pagesz = qc_poolpage_size(qcache_max);
547 
548 	qcache_idx_max = qcache_max >> vm->vm_quantum_shift;
549 	prevqc = NULL;
550 	for (i = qcache_idx_max; i > 0; i--) {
551 		qcache_t *qc = &vm->vm_qcache_store[i - 1];
552 		size_t size = i << vm->vm_quantum_shift;
553 		pool_cache_t pc;
554 
555 		qc->qc_vmem = vm;
556 		snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu",
557 		    vm->vm_name, size);
558 
559 		pc = pool_cache_init(size,
560 		    ORDER2SIZE(vm->vm_quantum_shift), 0,
561 		    PR_NOALIGN | PR_NOTOUCH | PR_RECURSIVE /* XXX */,
562 		    qc->qc_name, pa, ipl, NULL, NULL, NULL);
563 
564 		KASSERT(pc);
565 
566 		qc->qc_cache = pc;
567 		KASSERT(qc->qc_cache != NULL);	/* XXX */
568 		if (prevqc != NULL &&
569 		    qc->qc_cache->pc_pool.pr_itemsperpage ==
570 		    prevqc->qc_cache->pc_pool.pr_itemsperpage) {
571 			pool_cache_destroy(qc->qc_cache);
572 			vm->vm_qcache[i - 1] = prevqc;
573 			continue;
574 		}
575 		qc->qc_cache->pc_pool.pr_qcache = qc;
576 		vm->vm_qcache[i - 1] = qc;
577 		prevqc = qc;
578 	}
579 }
580 
581 static void
582 qc_destroy(vmem_t *vm)
583 {
584 	const qcache_t *prevqc;
585 	int i;
586 	int qcache_idx_max;
587 
588 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
589 	prevqc = NULL;
590 	for (i = 0; i < qcache_idx_max; i++) {
591 		qcache_t *qc = vm->vm_qcache[i];
592 
593 		if (prevqc == qc) {
594 			continue;
595 		}
596 		pool_cache_destroy(qc->qc_cache);
597 		prevqc = qc;
598 	}
599 }
600 #endif
601 
602 #if defined(_KERNEL)
603 static void
604 vmem_bootstrap(void)
605 {
606 
607 	mutex_init(&vmem_list_lock, MUTEX_DEFAULT, IPL_VM);
608 	mutex_init(&vmem_refill_lock, MUTEX_DEFAULT, IPL_VM);
609 	mutex_init(&vmem_btag_lock, MUTEX_DEFAULT, IPL_VM);
610 
611 	while (static_bt_count-- > 0) {
612 		bt_t *bt = &static_bts[static_bt_count];
613 		LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
614 		VMEM_EVCNT_INCR(bt_count);
615 		vmem_btag_freelist_count++;
616 	}
617 	vmem_bootstrapped = TRUE;
618 }
619 
620 void
621 vmem_subsystem_init(vmem_t *vm)
622 {
623 
624 	kmem_va_meta_arena = vmem_init(&kmem_va_meta_arena_store, "vmem-va",
625 	    0, 0, PAGE_SIZE, vmem_alloc, vmem_free, vm,
626 	    0, VM_NOSLEEP | VM_BOOTSTRAP | VM_LARGEIMPORT,
627 	    IPL_VM);
628 
629 	kmem_meta_arena = vmem_init(&kmem_meta_arena_store, "vmem-meta",
630 	    0, 0, PAGE_SIZE,
631 	    uvm_km_kmem_alloc, uvm_km_kmem_free, kmem_va_meta_arena,
632 	    0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM);
633 }
634 #endif /* defined(_KERNEL) */
635 
636 static int
637 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags,
638     int spanbttype)
639 {
640 	bt_t *btspan;
641 	bt_t *btfree;
642 
643 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
644 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
645 	KASSERT(spanbttype == BT_TYPE_SPAN ||
646 	    spanbttype == BT_TYPE_SPAN_STATIC);
647 
648 	btspan = bt_alloc(vm, flags);
649 	if (btspan == NULL) {
650 		return ENOMEM;
651 	}
652 	btfree = bt_alloc(vm, flags);
653 	if (btfree == NULL) {
654 		bt_free(vm, btspan);
655 		return ENOMEM;
656 	}
657 
658 	btspan->bt_type = spanbttype;
659 	btspan->bt_start = addr;
660 	btspan->bt_size = size;
661 
662 	btfree->bt_type = BT_TYPE_FREE;
663 	btfree->bt_start = addr;
664 	btfree->bt_size = size;
665 
666 	VMEM_LOCK(vm);
667 	bt_insseg_tail(vm, btspan);
668 	bt_insseg(vm, btfree, btspan);
669 	bt_insfree(vm, btfree);
670 	vm->vm_size += size;
671 	VMEM_UNLOCK(vm);
672 
673 	return 0;
674 }
675 
676 static void
677 vmem_destroy1(vmem_t *vm)
678 {
679 
680 #if defined(QCACHE)
681 	qc_destroy(vm);
682 #endif /* defined(QCACHE) */
683 	if (vm->vm_hashlist != NULL) {
684 		int i;
685 
686 		for (i = 0; i < vm->vm_hashsize; i++) {
687 			bt_t *bt;
688 
689 			while ((bt = LIST_FIRST(&vm->vm_hashlist[i])) != NULL) {
690 				KASSERT(bt->bt_type == BT_TYPE_SPAN_STATIC);
691 				bt_free(vm, bt);
692 			}
693 		}
694 		if (vm->vm_hashlist != &vm->vm_hash0) {
695 			xfree(vm->vm_hashlist,
696 			    sizeof(struct vmem_hashlist *) * vm->vm_hashsize);
697 		}
698 	}
699 
700 	while (vm->vm_nfreetags > 0) {
701 		bt_t *bt = LIST_FIRST(&vm->vm_freetags);
702 		LIST_REMOVE(bt, bt_freelist);
703 		vm->vm_nfreetags--;
704 		mutex_enter(&vmem_btag_lock);
705 #if defined (_KERNEL)
706 		LIST_INSERT_HEAD(&vmem_btag_freelist, bt, bt_freelist);
707 		vmem_btag_freelist_count++;
708 #endif /* defined(_KERNEL) */
709 		mutex_exit(&vmem_btag_lock);
710 	}
711 
712 	VMEM_CONDVAR_DESTROY(vm);
713 	VMEM_LOCK_DESTROY(vm);
714 	xfree(vm, sizeof(*vm));
715 }
716 
717 static int
718 vmem_import(vmem_t *vm, vmem_size_t size, vm_flag_t flags)
719 {
720 	vmem_addr_t addr;
721 	int rc;
722 
723 	if (vm->vm_importfn == NULL) {
724 		return EINVAL;
725 	}
726 
727 	if (vm->vm_flags & VM_LARGEIMPORT) {
728 		size *= 16;
729 	}
730 
731 	if (vm->vm_flags & VM_XIMPORT) {
732 		rc = ((vmem_ximport_t *)vm->vm_importfn)(vm->vm_arg, size,
733 		    &size, flags, &addr);
734 	} else {
735 		rc = (vm->vm_importfn)(vm->vm_arg, size, flags, &addr);
736 	}
737 	if (rc) {
738 		return ENOMEM;
739 	}
740 
741 	if (vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN) != 0) {
742 		(*vm->vm_releasefn)(vm->vm_arg, addr, size);
743 		return ENOMEM;
744 	}
745 
746 	return 0;
747 }
748 
749 static int
750 vmem_rehash(vmem_t *vm, size_t newhashsize, vm_flag_t flags)
751 {
752 	bt_t *bt;
753 	int i;
754 	struct vmem_hashlist *newhashlist;
755 	struct vmem_hashlist *oldhashlist;
756 	size_t oldhashsize;
757 
758 	KASSERT(newhashsize > 0);
759 
760 	newhashlist =
761 	    xmalloc(sizeof(struct vmem_hashlist *) * newhashsize, flags);
762 	if (newhashlist == NULL) {
763 		return ENOMEM;
764 	}
765 	for (i = 0; i < newhashsize; i++) {
766 		LIST_INIT(&newhashlist[i]);
767 	}
768 
769 	if (!VMEM_TRYLOCK(vm)) {
770 		xfree(newhashlist,
771 		    sizeof(struct vmem_hashlist *) * newhashsize);
772 		return EBUSY;
773 	}
774 	oldhashlist = vm->vm_hashlist;
775 	oldhashsize = vm->vm_hashsize;
776 	vm->vm_hashlist = newhashlist;
777 	vm->vm_hashsize = newhashsize;
778 	if (oldhashlist == NULL) {
779 		VMEM_UNLOCK(vm);
780 		return 0;
781 	}
782 	for (i = 0; i < oldhashsize; i++) {
783 		while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
784 			bt_rembusy(vm, bt); /* XXX */
785 			bt_insbusy(vm, bt);
786 		}
787 	}
788 	VMEM_UNLOCK(vm);
789 
790 	if (oldhashlist != &vm->vm_hash0) {
791 		xfree(oldhashlist,
792 		    sizeof(struct vmem_hashlist *) * oldhashsize);
793 	}
794 
795 	return 0;
796 }
797 
798 /*
799  * vmem_fit: check if a bt can satisfy the given restrictions.
800  *
801  * it's a caller's responsibility to ensure the region is big enough
802  * before calling us.
803  */
804 
805 static int
806 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align,
807     vmem_size_t phase, vmem_size_t nocross,
808     vmem_addr_t minaddr, vmem_addr_t maxaddr, vmem_addr_t *addrp)
809 {
810 	vmem_addr_t start;
811 	vmem_addr_t end;
812 
813 	KASSERT(size > 0);
814 	KASSERT(bt->bt_size >= size); /* caller's responsibility */
815 
816 	/*
817 	 * XXX assumption: vmem_addr_t and vmem_size_t are
818 	 * unsigned integer of the same size.
819 	 */
820 
821 	start = bt->bt_start;
822 	if (start < minaddr) {
823 		start = minaddr;
824 	}
825 	end = BT_END(bt);
826 	if (end > maxaddr) {
827 		end = maxaddr;
828 	}
829 	if (start > end) {
830 		return ENOMEM;
831 	}
832 
833 	start = VMEM_ALIGNUP(start - phase, align) + phase;
834 	if (start < bt->bt_start) {
835 		start += align;
836 	}
837 	if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
838 		KASSERT(align < nocross);
839 		start = VMEM_ALIGNUP(start - phase, nocross) + phase;
840 	}
841 	if (start <= end && end - start >= size - 1) {
842 		KASSERT((start & (align - 1)) == phase);
843 		KASSERT(!VMEM_CROSS_P(start, start + size - 1, nocross));
844 		KASSERT(minaddr <= start);
845 		KASSERT(maxaddr == 0 || start + size - 1 <= maxaddr);
846 		KASSERT(bt->bt_start <= start);
847 		KASSERT(BT_END(bt) - start >= size - 1);
848 		*addrp = start;
849 		return 0;
850 	}
851 	return ENOMEM;
852 }
853 
854 /* ---- vmem API */
855 
856 /*
857  * vmem_create_internal: creates a vmem arena.
858  */
859 
860 vmem_t *
861 vmem_init(vmem_t *vm, const char *name,
862     vmem_addr_t base, vmem_size_t size, vmem_size_t quantum,
863     vmem_import_t *importfn, vmem_release_t *releasefn,
864     vmem_t *arg, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
865 {
866 	int i;
867 
868 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
869 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
870 	KASSERT(quantum > 0);
871 
872 #if defined(_KERNEL)
873 	/* XXX: SMP, we get called early... */
874 	if (!vmem_bootstrapped) {
875 		vmem_bootstrap();
876 	}
877 #endif /* defined(_KERNEL) */
878 
879 	if (vm == NULL) {
880 		vm = xmalloc(sizeof(*vm), flags);
881 	}
882 	if (vm == NULL) {
883 		return NULL;
884 	}
885 
886 	VMEM_CONDVAR_INIT(vm, "vmem");
887 	VMEM_LOCK_INIT(vm, ipl);
888 	vm->vm_flags = flags;
889 	vm->vm_nfreetags = 0;
890 	LIST_INIT(&vm->vm_freetags);
891 	strlcpy(vm->vm_name, name, sizeof(vm->vm_name));
892 	vm->vm_quantum_mask = quantum - 1;
893 	vm->vm_quantum_shift = SIZE2ORDER(quantum);
894 	KASSERT(ORDER2SIZE(vm->vm_quantum_shift) == quantum);
895 	vm->vm_importfn = importfn;
896 	vm->vm_releasefn = releasefn;
897 	vm->vm_arg = arg;
898 	vm->vm_nbusytag = 0;
899 	vm->vm_size = 0;
900 	vm->vm_inuse = 0;
901 #if defined(QCACHE)
902 	qc_init(vm, qcache_max, ipl);
903 #endif /* defined(QCACHE) */
904 
905 	CIRCLEQ_INIT(&vm->vm_seglist);
906 	for (i = 0; i < VMEM_MAXORDER; i++) {
907 		LIST_INIT(&vm->vm_freelist[i]);
908 	}
909 	memset(&vm->vm_hash0, 0, sizeof(struct vmem_hashlist));
910 	vm->vm_hashsize = 1;
911 	vm->vm_hashlist = &vm->vm_hash0;
912 
913 	if (size != 0) {
914 		if (vmem_add(vm, base, size, flags) != 0) {
915 			vmem_destroy1(vm);
916 			return NULL;
917 		}
918 	}
919 
920 #if defined(_KERNEL)
921 	if (flags & VM_BOOTSTRAP) {
922 		bt_refill(vm, VM_NOSLEEP);
923 	}
924 
925 	mutex_enter(&vmem_list_lock);
926 	LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist);
927 	mutex_exit(&vmem_list_lock);
928 #endif /* defined(_KERNEL) */
929 
930 	return vm;
931 }
932 
933 
934 
935 /*
936  * vmem_create: create an arena.
937  *
938  * => must not be called from interrupt context.
939  */
940 
941 vmem_t *
942 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
943     vmem_size_t quantum, vmem_import_t *importfn, vmem_release_t *releasefn,
944     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
945 {
946 
947 	KASSERT((flags & (VM_XIMPORT)) == 0);
948 
949 	return vmem_init(NULL, name, base, size, quantum,
950 	    importfn, releasefn, source, qcache_max, flags, ipl);
951 }
952 
953 /*
954  * vmem_xcreate: create an arena takes alternative import func.
955  *
956  * => must not be called from interrupt context.
957  */
958 
959 vmem_t *
960 vmem_xcreate(const char *name, vmem_addr_t base, vmem_size_t size,
961     vmem_size_t quantum, vmem_ximport_t *importfn, vmem_release_t *releasefn,
962     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags, int ipl)
963 {
964 
965 	KASSERT((flags & (VM_XIMPORT)) == 0);
966 
967 	return vmem_init(NULL, name, base, size, quantum,
968 	    (vmem_import_t *)importfn, releasefn, source,
969 	    qcache_max, flags | VM_XIMPORT, ipl);
970 }
971 
972 void
973 vmem_destroy(vmem_t *vm)
974 {
975 
976 #if defined(_KERNEL)
977 	mutex_enter(&vmem_list_lock);
978 	LIST_REMOVE(vm, vm_alllist);
979 	mutex_exit(&vmem_list_lock);
980 #endif /* defined(_KERNEL) */
981 
982 	vmem_destroy1(vm);
983 }
984 
985 vmem_size_t
986 vmem_roundup_size(vmem_t *vm, vmem_size_t size)
987 {
988 
989 	return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
990 }
991 
992 /*
993  * vmem_alloc:
994  *
995  * => caller must ensure appropriate spl,
996  *    if the arena can be accessed from interrupt context.
997  */
998 
999 int
1000 vmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, vmem_addr_t *addrp)
1001 {
1002 	const vm_flag_t strat __unused = flags & VM_FITMASK;
1003 
1004 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
1005 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
1006 
1007 	KASSERT(size > 0);
1008 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
1009 	if ((flags & VM_SLEEP) != 0) {
1010 		ASSERT_SLEEPABLE();
1011 	}
1012 
1013 #if defined(QCACHE)
1014 	if (size <= vm->vm_qcache_max) {
1015 		void *p;
1016 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1017 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1018 
1019 		p = pool_cache_get(qc->qc_cache, vmf_to_prf(flags));
1020 		if (addrp != NULL)
1021 			*addrp = (vmem_addr_t)p;
1022 		return (p == NULL) ? ENOMEM : 0;
1023 	}
1024 #endif /* defined(QCACHE) */
1025 
1026 	return vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
1027 	    flags, addrp);
1028 }
1029 
1030 int
1031 vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align,
1032     const vmem_size_t phase, const vmem_size_t nocross,
1033     const vmem_addr_t minaddr, const vmem_addr_t maxaddr, const vm_flag_t flags,
1034     vmem_addr_t *addrp)
1035 {
1036 	struct vmem_freelist *list;
1037 	struct vmem_freelist *first;
1038 	struct vmem_freelist *end;
1039 	bt_t *bt;
1040 	bt_t *btnew;
1041 	bt_t *btnew2;
1042 	const vmem_size_t size = vmem_roundup_size(vm, size0);
1043 	vm_flag_t strat = flags & VM_FITMASK;
1044 	vmem_addr_t start;
1045 	int rc;
1046 
1047 	KASSERT(size0 > 0);
1048 	KASSERT(size > 0);
1049 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
1050 	if ((flags & VM_SLEEP) != 0) {
1051 		ASSERT_SLEEPABLE();
1052 	}
1053 	KASSERT((align & vm->vm_quantum_mask) == 0);
1054 	KASSERT((align & (align - 1)) == 0);
1055 	KASSERT((phase & vm->vm_quantum_mask) == 0);
1056 	KASSERT((nocross & vm->vm_quantum_mask) == 0);
1057 	KASSERT((nocross & (nocross - 1)) == 0);
1058 	KASSERT((align == 0 && phase == 0) || phase < align);
1059 	KASSERT(nocross == 0 || nocross >= size);
1060 	KASSERT(minaddr <= maxaddr);
1061 	KASSERT(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
1062 
1063 	if (align == 0) {
1064 		align = vm->vm_quantum_mask + 1;
1065 	}
1066 
1067 	/*
1068 	 * allocate boundary tags before acquiring the vmem lock.
1069 	 */
1070 	btnew = bt_alloc(vm, flags);
1071 	if (btnew == NULL) {
1072 		return ENOMEM;
1073 	}
1074 	btnew2 = bt_alloc(vm, flags); /* XXX not necessary if no restrictions */
1075 	if (btnew2 == NULL) {
1076 		bt_free(vm, btnew);
1077 		return ENOMEM;
1078 	}
1079 
1080 	/*
1081 	 * choose a free block from which we allocate.
1082 	 */
1083 retry_strat:
1084 	first = bt_freehead_toalloc(vm, size, strat);
1085 	end = &vm->vm_freelist[VMEM_MAXORDER];
1086 retry:
1087 	bt = NULL;
1088 	VMEM_LOCK(vm);
1089 	vmem_check(vm);
1090 	if (strat == VM_INSTANTFIT) {
1091 		/*
1092 		 * just choose the first block which satisfies our restrictions.
1093 		 *
1094 		 * note that we don't need to check the size of the blocks
1095 		 * because any blocks found on these list should be larger than
1096 		 * the given size.
1097 		 */
1098 		for (list = first; list < end; list++) {
1099 			bt = LIST_FIRST(list);
1100 			if (bt != NULL) {
1101 				rc = vmem_fit(bt, size, align, phase,
1102 				    nocross, minaddr, maxaddr, &start);
1103 				if (rc == 0) {
1104 					goto gotit;
1105 				}
1106 				/*
1107 				 * don't bother to follow the bt_freelist link
1108 				 * here.  the list can be very long and we are
1109 				 * told to run fast.  blocks from the later free
1110 				 * lists are larger and have better chances to
1111 				 * satisfy our restrictions.
1112 				 */
1113 			}
1114 		}
1115 	} else { /* VM_BESTFIT */
1116 		/*
1117 		 * we assume that, for space efficiency, it's better to
1118 		 * allocate from a smaller block.  thus we will start searching
1119 		 * from the lower-order list than VM_INSTANTFIT.
1120 		 * however, don't bother to find the smallest block in a free
1121 		 * list because the list can be very long.  we can revisit it
1122 		 * if/when it turns out to be a problem.
1123 		 *
1124 		 * note that the 'first' list can contain blocks smaller than
1125 		 * the requested size.  thus we need to check bt_size.
1126 		 */
1127 		for (list = first; list < end; list++) {
1128 			LIST_FOREACH(bt, list, bt_freelist) {
1129 				if (bt->bt_size >= size) {
1130 					rc = vmem_fit(bt, size, align, phase,
1131 					    nocross, minaddr, maxaddr, &start);
1132 					if (rc == 0) {
1133 						goto gotit;
1134 					}
1135 				}
1136 			}
1137 		}
1138 	}
1139 	VMEM_UNLOCK(vm);
1140 #if 1
1141 	if (strat == VM_INSTANTFIT) {
1142 		strat = VM_BESTFIT;
1143 		goto retry_strat;
1144 	}
1145 #endif
1146 	if (align != vm->vm_quantum_mask + 1 || phase != 0 || nocross != 0) {
1147 
1148 		/*
1149 		 * XXX should try to import a region large enough to
1150 		 * satisfy restrictions?
1151 		 */
1152 
1153 		goto fail;
1154 	}
1155 	/* XXX eeek, minaddr & maxaddr not respected */
1156 	if (vmem_import(vm, size, flags) == 0) {
1157 		goto retry;
1158 	}
1159 	/* XXX */
1160 
1161 	if ((flags & VM_SLEEP) != 0) {
1162 #if defined(_KERNEL) && !defined(_RUMPKERNEL)
1163 		mutex_spin_enter(&uvm_fpageqlock);
1164 		uvm_kick_pdaemon();
1165 		mutex_spin_exit(&uvm_fpageqlock);
1166 #endif
1167 		VMEM_LOCK(vm);
1168 		VMEM_CONDVAR_WAIT(vm);
1169 		VMEM_UNLOCK(vm);
1170 		goto retry;
1171 	}
1172 fail:
1173 	bt_free(vm, btnew);
1174 	bt_free(vm, btnew2);
1175 	return ENOMEM;
1176 
1177 gotit:
1178 	KASSERT(bt->bt_type == BT_TYPE_FREE);
1179 	KASSERT(bt->bt_size >= size);
1180 	bt_remfree(vm, bt);
1181 	vmem_check(vm);
1182 	if (bt->bt_start != start) {
1183 		btnew2->bt_type = BT_TYPE_FREE;
1184 		btnew2->bt_start = bt->bt_start;
1185 		btnew2->bt_size = start - bt->bt_start;
1186 		bt->bt_start = start;
1187 		bt->bt_size -= btnew2->bt_size;
1188 		bt_insfree(vm, btnew2);
1189 		bt_insseg(vm, btnew2, CIRCLEQ_PREV(bt, bt_seglist));
1190 		btnew2 = NULL;
1191 		vmem_check(vm);
1192 	}
1193 	KASSERT(bt->bt_start == start);
1194 	if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
1195 		/* split */
1196 		btnew->bt_type = BT_TYPE_BUSY;
1197 		btnew->bt_start = bt->bt_start;
1198 		btnew->bt_size = size;
1199 		bt->bt_start = bt->bt_start + size;
1200 		bt->bt_size -= size;
1201 		bt_insfree(vm, bt);
1202 		bt_insseg(vm, btnew, CIRCLEQ_PREV(bt, bt_seglist));
1203 		bt_insbusy(vm, btnew);
1204 		vmem_check(vm);
1205 		VMEM_UNLOCK(vm);
1206 	} else {
1207 		bt->bt_type = BT_TYPE_BUSY;
1208 		bt_insbusy(vm, bt);
1209 		vmem_check(vm);
1210 		VMEM_UNLOCK(vm);
1211 		bt_free(vm, btnew);
1212 		btnew = bt;
1213 	}
1214 	if (btnew2 != NULL) {
1215 		bt_free(vm, btnew2);
1216 	}
1217 	KASSERT(btnew->bt_size >= size);
1218 	btnew->bt_type = BT_TYPE_BUSY;
1219 
1220 	if (addrp != NULL)
1221 		*addrp = btnew->bt_start;
1222 	return 0;
1223 }
1224 
1225 /*
1226  * vmem_free:
1227  *
1228  * => caller must ensure appropriate spl,
1229  *    if the arena can be accessed from interrupt context.
1230  */
1231 
1232 void
1233 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1234 {
1235 
1236 	KASSERT(size > 0);
1237 
1238 #if defined(QCACHE)
1239 	if (size <= vm->vm_qcache_max) {
1240 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1241 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1242 
1243 		pool_cache_put(qc->qc_cache, (void *)addr);
1244 		return;
1245 	}
1246 #endif /* defined(QCACHE) */
1247 
1248 	vmem_xfree(vm, addr, size);
1249 }
1250 
1251 void
1252 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1253 {
1254 	bt_t *bt;
1255 	bt_t *t;
1256 	LIST_HEAD(, vmem_btag) tofree;
1257 
1258 	LIST_INIT(&tofree);
1259 
1260 	KASSERT(size > 0);
1261 
1262 	VMEM_LOCK(vm);
1263 
1264 	bt = bt_lookupbusy(vm, addr);
1265 	KASSERT(bt != NULL);
1266 	KASSERT(bt->bt_start == addr);
1267 	KASSERT(bt->bt_size == vmem_roundup_size(vm, size) ||
1268 	    bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
1269 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
1270 	bt_rembusy(vm, bt);
1271 	bt->bt_type = BT_TYPE_FREE;
1272 
1273 	/* coalesce */
1274 	t = CIRCLEQ_NEXT(bt, bt_seglist);
1275 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1276 		KASSERT(BT_END(bt) < t->bt_start);	/* YYY */
1277 		bt_remfree(vm, t);
1278 		bt_remseg(vm, t);
1279 		bt->bt_size += t->bt_size;
1280 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1281 	}
1282 	t = CIRCLEQ_PREV(bt, bt_seglist);
1283 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1284 		KASSERT(BT_END(t) < bt->bt_start);	/* YYY */
1285 		bt_remfree(vm, t);
1286 		bt_remseg(vm, t);
1287 		bt->bt_size += t->bt_size;
1288 		bt->bt_start = t->bt_start;
1289 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1290 	}
1291 
1292 	t = CIRCLEQ_PREV(bt, bt_seglist);
1293 	KASSERT(t != NULL);
1294 	KASSERT(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY);
1295 	if (vm->vm_releasefn != NULL && t->bt_type == BT_TYPE_SPAN &&
1296 	    t->bt_size == bt->bt_size) {
1297 		vmem_addr_t spanaddr;
1298 		vmem_size_t spansize;
1299 
1300 		KASSERT(t->bt_start == bt->bt_start);
1301 		spanaddr = bt->bt_start;
1302 		spansize = bt->bt_size;
1303 		bt_remseg(vm, bt);
1304 		LIST_INSERT_HEAD(&tofree, bt, bt_freelist);
1305 		bt_remseg(vm, t);
1306 		LIST_INSERT_HEAD(&tofree, t, bt_freelist);
1307 		vm->vm_size -= spansize;
1308 		VMEM_CONDVAR_BROADCAST(vm);
1309 		VMEM_UNLOCK(vm);
1310 		(*vm->vm_releasefn)(vm->vm_arg, spanaddr, spansize);
1311 	} else {
1312 		bt_insfree(vm, bt);
1313 		VMEM_CONDVAR_BROADCAST(vm);
1314 		VMEM_UNLOCK(vm);
1315 	}
1316 
1317 	while (!LIST_EMPTY(&tofree)) {
1318 		t = LIST_FIRST(&tofree);
1319 		LIST_REMOVE(t, bt_freelist);
1320 		bt_free(vm, t);
1321 	}
1322 }
1323 
1324 /*
1325  * vmem_add:
1326  *
1327  * => caller must ensure appropriate spl,
1328  *    if the arena can be accessed from interrupt context.
1329  */
1330 
1331 int
1332 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags)
1333 {
1334 
1335 	return vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN_STATIC);
1336 }
1337 
1338 /*
1339  * vmem_size: information about arenas size
1340  *
1341  * => return free/allocated size in arena
1342  */
1343 vmem_size_t
1344 vmem_size(vmem_t *vm, int typemask)
1345 {
1346 
1347 	switch (typemask) {
1348 	case VMEM_ALLOC:
1349 		return vm->vm_inuse;
1350 	case VMEM_FREE:
1351 		return vm->vm_size - vm->vm_inuse;
1352 	case VMEM_FREE|VMEM_ALLOC:
1353 		return vm->vm_size;
1354 	default:
1355 		panic("vmem_size");
1356 	}
1357 }
1358 
1359 /* ---- rehash */
1360 
1361 #if defined(_KERNEL)
1362 static struct callout vmem_rehash_ch;
1363 static int vmem_rehash_interval;
1364 static struct workqueue *vmem_rehash_wq;
1365 static struct work vmem_rehash_wk;
1366 
1367 static void
1368 vmem_rehash_all(struct work *wk, void *dummy)
1369 {
1370 	vmem_t *vm;
1371 
1372 	KASSERT(wk == &vmem_rehash_wk);
1373 	mutex_enter(&vmem_list_lock);
1374 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1375 		size_t desired;
1376 		size_t current;
1377 
1378 		if (!VMEM_TRYLOCK(vm)) {
1379 			continue;
1380 		}
1381 		desired = vm->vm_nbusytag;
1382 		current = vm->vm_hashsize;
1383 		VMEM_UNLOCK(vm);
1384 
1385 		if (desired > VMEM_HASHSIZE_MAX) {
1386 			desired = VMEM_HASHSIZE_MAX;
1387 		} else if (desired < VMEM_HASHSIZE_MIN) {
1388 			desired = VMEM_HASHSIZE_MIN;
1389 		}
1390 		if (desired > current * 2 || desired * 2 < current) {
1391 			vmem_rehash(vm, desired, VM_NOSLEEP);
1392 		}
1393 	}
1394 	mutex_exit(&vmem_list_lock);
1395 
1396 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1397 }
1398 
1399 static void
1400 vmem_rehash_all_kick(void *dummy)
1401 {
1402 
1403 	workqueue_enqueue(vmem_rehash_wq, &vmem_rehash_wk, NULL);
1404 }
1405 
1406 void
1407 vmem_rehash_start(void)
1408 {
1409 	int error;
1410 
1411 	error = workqueue_create(&vmem_rehash_wq, "vmem_rehash",
1412 	    vmem_rehash_all, NULL, PRI_VM, IPL_SOFTCLOCK, WQ_MPSAFE);
1413 	if (error) {
1414 		panic("%s: workqueue_create %d\n", __func__, error);
1415 	}
1416 	callout_init(&vmem_rehash_ch, CALLOUT_MPSAFE);
1417 	callout_setfunc(&vmem_rehash_ch, vmem_rehash_all_kick, NULL);
1418 
1419 	vmem_rehash_interval = hz * 10;
1420 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1421 }
1422 #endif /* defined(_KERNEL) */
1423 
1424 /* ---- debug */
1425 
1426 #if defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY)
1427 
1428 static void bt_dump(const bt_t *, void (*)(const char *, ...));
1429 
1430 static const char *
1431 bt_type_string(int type)
1432 {
1433 	static const char * const table[] = {
1434 		[BT_TYPE_BUSY] = "busy",
1435 		[BT_TYPE_FREE] = "free",
1436 		[BT_TYPE_SPAN] = "span",
1437 		[BT_TYPE_SPAN_STATIC] = "static span",
1438 	};
1439 
1440 	if (type >= __arraycount(table)) {
1441 		return "BOGUS";
1442 	}
1443 	return table[type];
1444 }
1445 
1446 static void
1447 bt_dump(const bt_t *bt, void (*pr)(const char *, ...))
1448 {
1449 
1450 	(*pr)("\t%p: %" PRIu64 ", %" PRIu64 ", %d(%s)\n",
1451 	    bt, (uint64_t)bt->bt_start, (uint64_t)bt->bt_size,
1452 	    bt->bt_type, bt_type_string(bt->bt_type));
1453 }
1454 
1455 static void
1456 vmem_dump(const vmem_t *vm , void (*pr)(const char *, ...))
1457 {
1458 	const bt_t *bt;
1459 	int i;
1460 
1461 	(*pr)("vmem %p '%s'\n", vm, vm->vm_name);
1462 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1463 		bt_dump(bt, pr);
1464 	}
1465 
1466 	for (i = 0; i < VMEM_MAXORDER; i++) {
1467 		const struct vmem_freelist *fl = &vm->vm_freelist[i];
1468 
1469 		if (LIST_EMPTY(fl)) {
1470 			continue;
1471 		}
1472 
1473 		(*pr)("freelist[%d]\n", i);
1474 		LIST_FOREACH(bt, fl, bt_freelist) {
1475 			bt_dump(bt, pr);
1476 		}
1477 	}
1478 }
1479 
1480 #endif /* defined(DDB) || defined(UNITTEST) || defined(VMEM_SANITY) */
1481 
1482 #if defined(DDB)
1483 static bt_t *
1484 vmem_whatis_lookup(vmem_t *vm, uintptr_t addr)
1485 {
1486 	bt_t *bt;
1487 
1488 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1489 		if (BT_ISSPAN_P(bt)) {
1490 			continue;
1491 		}
1492 		if (bt->bt_start <= addr && addr <= BT_END(bt)) {
1493 			return bt;
1494 		}
1495 	}
1496 
1497 	return NULL;
1498 }
1499 
1500 void
1501 vmem_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1502 {
1503 	vmem_t *vm;
1504 
1505 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1506 		bt_t *bt;
1507 
1508 		bt = vmem_whatis_lookup(vm, addr);
1509 		if (bt == NULL) {
1510 			continue;
1511 		}
1512 		(*pr)("%p is %p+%zu in VMEM '%s' (%s)\n",
1513 		    (void *)addr, (void *)bt->bt_start,
1514 		    (size_t)(addr - bt->bt_start), vm->vm_name,
1515 		    (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free");
1516 	}
1517 }
1518 
1519 void
1520 vmem_printall(const char *modif, void (*pr)(const char *, ...))
1521 {
1522 	const vmem_t *vm;
1523 
1524 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1525 		vmem_dump(vm, pr);
1526 	}
1527 }
1528 
1529 void
1530 vmem_print(uintptr_t addr, const char *modif, void (*pr)(const char *, ...))
1531 {
1532 	const vmem_t *vm = (const void *)addr;
1533 
1534 	vmem_dump(vm, pr);
1535 }
1536 #endif /* defined(DDB) */
1537 
1538 #if defined(_KERNEL)
1539 #define vmem_printf printf
1540 #else
1541 #include <stdio.h>
1542 #include <stdarg.h>
1543 
1544 static void
1545 vmem_printf(const char *fmt, ...)
1546 {
1547 	va_list ap;
1548 	va_start(ap, fmt);
1549 	vprintf(fmt, ap);
1550 	va_end(ap);
1551 }
1552 #endif
1553 
1554 #if defined(VMEM_SANITY)
1555 
1556 static bool
1557 vmem_check_sanity(vmem_t *vm)
1558 {
1559 	const bt_t *bt, *bt2;
1560 
1561 	KASSERT(vm != NULL);
1562 
1563 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1564 		if (bt->bt_start > BT_END(bt)) {
1565 			printf("corrupted tag\n");
1566 			bt_dump(bt, vmem_printf);
1567 			return false;
1568 		}
1569 	}
1570 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1571 		CIRCLEQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) {
1572 			if (bt == bt2) {
1573 				continue;
1574 			}
1575 			if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) {
1576 				continue;
1577 			}
1578 			if (bt->bt_start <= BT_END(bt2) &&
1579 			    bt2->bt_start <= BT_END(bt)) {
1580 				printf("overwrapped tags\n");
1581 				bt_dump(bt, vmem_printf);
1582 				bt_dump(bt2, vmem_printf);
1583 				return false;
1584 			}
1585 		}
1586 	}
1587 
1588 	return true;
1589 }
1590 
1591 static void
1592 vmem_check(vmem_t *vm)
1593 {
1594 
1595 	if (!vmem_check_sanity(vm)) {
1596 		panic("insanity vmem %p", vm);
1597 	}
1598 }
1599 
1600 #endif /* defined(VMEM_SANITY) */
1601 
1602 #if defined(UNITTEST)
1603 int
1604 main(void)
1605 {
1606 	int rc;
1607 	vmem_t *vm;
1608 	vmem_addr_t p;
1609 	struct reg {
1610 		vmem_addr_t p;
1611 		vmem_size_t sz;
1612 		bool x;
1613 	} *reg = NULL;
1614 	int nreg = 0;
1615 	int nalloc = 0;
1616 	int nfree = 0;
1617 	vmem_size_t total = 0;
1618 #if 1
1619 	vm_flag_t strat = VM_INSTANTFIT;
1620 #else
1621 	vm_flag_t strat = VM_BESTFIT;
1622 #endif
1623 
1624 	vm = vmem_create("test", 0, 0, 1, NULL, NULL, NULL, 0, VM_SLEEP,
1625 #ifdef _KERNEL
1626 	    IPL_NONE
1627 #else
1628 	    0
1629 #endif
1630 	    );
1631 	if (vm == NULL) {
1632 		printf("vmem_create\n");
1633 		exit(EXIT_FAILURE);
1634 	}
1635 	vmem_dump(vm, vmem_printf);
1636 
1637 	rc = vmem_add(vm, 0, 50, VM_SLEEP);
1638 	assert(rc == 0);
1639 	rc = vmem_add(vm, 100, 200, VM_SLEEP);
1640 	assert(rc == 0);
1641 	rc = vmem_add(vm, 2000, 1, VM_SLEEP);
1642 	assert(rc == 0);
1643 	rc = vmem_add(vm, 40000, 65536, VM_SLEEP);
1644 	assert(rc == 0);
1645 	rc = vmem_add(vm, 10000, 10000, VM_SLEEP);
1646 	assert(rc == 0);
1647 	rc = vmem_add(vm, 500, 1000, VM_SLEEP);
1648 	assert(rc == 0);
1649 	rc = vmem_add(vm, 0xffffff00, 0x100, VM_SLEEP);
1650 	assert(rc == 0);
1651 	rc = vmem_xalloc(vm, 0x101, 0, 0, 0,
1652 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1653 	assert(rc != 0);
1654 	rc = vmem_xalloc(vm, 50, 0, 0, 0, 0, 49, strat|VM_SLEEP, &p);
1655 	assert(rc == 0 && p == 0);
1656 	vmem_xfree(vm, p, 50);
1657 	rc = vmem_xalloc(vm, 25, 0, 0, 0, 0, 24, strat|VM_SLEEP, &p);
1658 	assert(rc == 0 && p == 0);
1659 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1660 	    0xffffff01, 0xffffffff, strat|VM_SLEEP, &p);
1661 	assert(rc != 0);
1662 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1663 	    0xffffff00, 0xfffffffe, strat|VM_SLEEP, &p);
1664 	assert(rc != 0);
1665 	rc = vmem_xalloc(vm, 0x100, 0, 0, 0,
1666 	    0xffffff00, 0xffffffff, strat|VM_SLEEP, &p);
1667 	assert(rc == 0);
1668 	vmem_dump(vm, vmem_printf);
1669 	for (;;) {
1670 		struct reg *r;
1671 		int t = rand() % 100;
1672 
1673 		if (t > 45) {
1674 			/* alloc */
1675 			vmem_size_t sz = rand() % 500 + 1;
1676 			bool x;
1677 			vmem_size_t align, phase, nocross;
1678 			vmem_addr_t minaddr, maxaddr;
1679 
1680 			if (t > 70) {
1681 				x = true;
1682 				/* XXX */
1683 				align = 1 << (rand() % 15);
1684 				phase = rand() % 65536;
1685 				nocross = 1 << (rand() % 15);
1686 				if (align <= phase) {
1687 					phase = 0;
1688 				}
1689 				if (VMEM_CROSS_P(phase, phase + sz - 1,
1690 				    nocross)) {
1691 					nocross = 0;
1692 				}
1693 				do {
1694 					minaddr = rand() % 50000;
1695 					maxaddr = rand() % 70000;
1696 				} while (minaddr > maxaddr);
1697 				printf("=== xalloc %" PRIu64
1698 				    " align=%" PRIu64 ", phase=%" PRIu64
1699 				    ", nocross=%" PRIu64 ", min=%" PRIu64
1700 				    ", max=%" PRIu64 "\n",
1701 				    (uint64_t)sz,
1702 				    (uint64_t)align,
1703 				    (uint64_t)phase,
1704 				    (uint64_t)nocross,
1705 				    (uint64_t)minaddr,
1706 				    (uint64_t)maxaddr);
1707 				rc = vmem_xalloc(vm, sz, align, phase, nocross,
1708 				    minaddr, maxaddr, strat|VM_SLEEP, &p);
1709 			} else {
1710 				x = false;
1711 				printf("=== alloc %" PRIu64 "\n", (uint64_t)sz);
1712 				rc = vmem_alloc(vm, sz, strat|VM_SLEEP, &p);
1713 			}
1714 			printf("-> %" PRIu64 "\n", (uint64_t)p);
1715 			vmem_dump(vm, vmem_printf);
1716 			if (rc != 0) {
1717 				if (x) {
1718 					continue;
1719 				}
1720 				break;
1721 			}
1722 			nreg++;
1723 			reg = realloc(reg, sizeof(*reg) * nreg);
1724 			r = &reg[nreg - 1];
1725 			r->p = p;
1726 			r->sz = sz;
1727 			r->x = x;
1728 			total += sz;
1729 			nalloc++;
1730 		} else if (nreg != 0) {
1731 			/* free */
1732 			r = &reg[rand() % nreg];
1733 			printf("=== free %" PRIu64 ", %" PRIu64 "\n",
1734 			    (uint64_t)r->p, (uint64_t)r->sz);
1735 			if (r->x) {
1736 				vmem_xfree(vm, r->p, r->sz);
1737 			} else {
1738 				vmem_free(vm, r->p, r->sz);
1739 			}
1740 			total -= r->sz;
1741 			vmem_dump(vm, vmem_printf);
1742 			*r = reg[nreg - 1];
1743 			nreg--;
1744 			nfree++;
1745 		}
1746 		printf("total=%" PRIu64 "\n", (uint64_t)total);
1747 	}
1748 	fprintf(stderr, "total=%" PRIu64 ", nalloc=%d, nfree=%d\n",
1749 	    (uint64_t)total, nalloc, nfree);
1750 	exit(EXIT_SUCCESS);
1751 }
1752 #endif /* defined(UNITTEST) */
1753