1/*-
2 * Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
3 * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice unmodified, this list of conditions, and the following
11 *    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 ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 *
29 */
30
31/*
32 * uma.h - External definitions for the Universal Memory Allocator
33 *
34*/
35
36#ifndef VM_UMA_H
37#define VM_UMA_H
38
39#include <sys/param.h>		/* For NULL */
40#include <sys/malloc.h>		/* For M_* */
41
42/* User visible parameters */
43#define UMA_SMALLEST_UNIT       (PAGE_SIZE / 256) /* Smallest item allocated */
44
45/* Types and type defs */
46
47struct uma_zone;
48/* Opaque type used as a handle to the zone */
49typedef struct uma_zone * uma_zone_t;
50
51void zone_drain(uma_zone_t);
52
53/*
54 * Item constructor
55 *
56 * Arguments:
57 *	item  A pointer to the memory which has been allocated.
58 *	arg   The arg field passed to uma_zalloc_arg
59 *	size  The size of the allocated item
60 *	flags See zalloc flags
61 *
62 * Returns:
63 *	0      on success
64 *      errno  on failure
65 *
66 * Discussion:
67 *	The constructor is called just before the memory is returned
68 *	to the user. It may block if necessary.
69 */
70typedef int (*uma_ctor)(void *mem, int size, void *arg, int flags);
71
72/*
73 * Item destructor
74 *
75 * Arguments:
76 *	item  A pointer to the memory which has been allocated.
77 *	size  The size of the item being destructed.
78 *	arg   Argument passed through uma_zfree_arg
79 *
80 * Returns:
81 *	Nothing
82 *
83 * Discussion:
84 *	The destructor may perform operations that differ from those performed
85 *	by the initializer, but it must leave the object in the same state.
86 *	This IS type stable storage.  This is called after EVERY zfree call.
87 */
88typedef void (*uma_dtor)(void *mem, int size, void *arg);
89
90/*
91 * Item initializer
92 *
93 * Arguments:
94 *	item  A pointer to the memory which has been allocated.
95 *	size  The size of the item being initialized.
96 *	flags See zalloc flags
97 *
98 * Returns:
99 *	0      on success
100 *      errno  on failure
101 *
102 * Discussion:
103 *	The initializer is called when the memory is cached in the uma zone.
104 *	The initializer and the destructor should leave the object in the same
105 *	state.
106 */
107typedef int (*uma_init)(void *mem, int size, int flags);
108
109/*
110 * Item discard function
111 *
112 * Arguments:
113 * 	item  A pointer to memory which has been 'freed' but has not left the
114 *	      zone's cache.
115 *	size  The size of the item being discarded.
116 *
117 * Returns:
118 *	Nothing
119 *
120 * Discussion:
121 *	This routine is called when memory leaves a zone and is returned to the
122 *	system for other uses.  It is the counter-part to the init function.
123 */
124typedef void (*uma_fini)(void *mem, int size);
125
126/*
127 * What's the difference between initializing and constructing?
128 *
129 * The item is initialized when it is cached, and this is the state that the
130 * object should be in when returned to the allocator. The purpose of this is
131 * to remove some code which would otherwise be called on each allocation by
132 * utilizing a known, stable state.  This differs from the constructor which
133 * will be called on EVERY allocation.
134 *
135 * For example, in the initializer you may want to initialize embedded locks,
136 * NULL list pointers, set up initial states, magic numbers, etc.  This way if
137 * the object is held in the allocator and re-used it won't be necessary to
138 * re-initialize it.
139 *
140 * The constructor may be used to lock a data structure, link it on to lists,
141 * bump reference counts or total counts of outstanding structures, etc.
142 *
143 */
144
145
146/* Function proto types */
147
148/*
149 * Create a new uma zone
150 *
151 * Arguments:
152 *	name  The text name of the zone for debugging and stats. This memory
153 *		should not be freed until the zone has been deallocated.
154 *	size  The size of the object that is being created.
155 *	ctor  The constructor that is called when the object is allocated.
156 *	dtor  The destructor that is called when the object is freed.
157 *	init  An initializer that sets up the initial state of the memory.
158 *	fini  A discard function that undoes initialization done by init.
159 *		ctor/dtor/init/fini may all be null, see notes above.
160 *	align A bitmask that corresponds to the requested alignment
161 *		eg 4 would be 0x3
162 *	flags A set of parameters that control the behavior of the zone.
163 *
164 * Returns:
165 *	A pointer to a structure which is intended to be opaque to users of
166 *	the interface.  The value may be null if the wait flag is not set.
167 */
168uma_zone_t uma_zcreate(const char *name, size_t size, uma_ctor ctor,
169		    uma_dtor dtor, uma_init uminit, uma_fini fini,
170		    int align, u_int32_t flags);
171
172/*
173 * Create a secondary uma zone
174 *
175 * Arguments:
176 *	name  The text name of the zone for debugging and stats. This memory
177 *		should not be freed until the zone has been deallocated.
178 *	ctor  The constructor that is called when the object is allocated.
179 *	dtor  The destructor that is called when the object is freed.
180 *	zinit  An initializer that sets up the initial state of the memory
181 *		as the object passes from the Keg's slab to the Zone's cache.
182 *	zfini  A discard function that undoes initialization done by init
183 *		as the object passes from the Zone's cache to the Keg's slab.
184 *
185 *		ctor/dtor/zinit/zfini may all be null, see notes above.
186 *		Note that the zinit and zfini specified here are NOT
187 *		exactly the same as the init/fini specified to uma_zcreate()
188 *		when creating a master zone.  These zinit/zfini are called
189 *		on the TRANSITION from keg to zone (and vice-versa). Once
190 *		these are set, the primary zone may alter its init/fini
191 *		(which are called when the object passes from VM to keg)
192 *		using uma_zone_set_init/fini()) as well as its own
193 *		zinit/zfini (unset by default for master zone) with
194 *		uma_zone_set_zinit/zfini() (note subtle 'z' prefix).
195 *
196 *	master  A reference to this zone's Master Zone (Primary Zone),
197 *		which contains the backing Keg for the Secondary Zone
198 *		being added.
199 *
200 * Returns:
201 *	A pointer to a structure which is intended to be opaque to users of
202 *	the interface.  The value may be null if the wait flag is not set.
203 */
204uma_zone_t uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
205		    uma_init zinit, uma_fini zfini, uma_zone_t master);
206
207/*
208 * Add a second master to a secondary zone.  This provides multiple data
209 * backends for objects with the same size.  Both masters must have
210 * compatible allocation flags.  Presently, UMA_ZONE_MALLOC type zones are
211 * the only supported.
212 *
213 * Returns:
214 * 	Error on failure, 0 on success.
215 */
216int uma_zsecond_add(uma_zone_t zone, uma_zone_t master);
217
218/*
219 * Definitions for uma_zcreate flags
220 *
221 * These flags share space with UMA_ZFLAGs in uma_int.h.  Be careful not to
222 * overlap when adding new features.  0xf0000000 is in use by uma_int.h.
223 */
224#define UMA_ZONE_PAGEABLE	0x0001	/* Return items not fully backed by
225					   physical memory XXX Not yet */
226#define UMA_ZONE_ZINIT		0x0002	/* Initialize with zeros */
227#define UMA_ZONE_STATIC		0x0004	/* Statically sized zone */
228#define UMA_ZONE_OFFPAGE	0x0008	/* Force the slab structure allocation
229					   off of the real memory */
230#define UMA_ZONE_MALLOC		0x0010	/* For use by malloc(9) only! */
231#define UMA_ZONE_NOFREE		0x0020	/* Do not free slabs of this type! */
232#define UMA_ZONE_MTXCLASS	0x0040	/* Create a new lock class */
233#define	UMA_ZONE_VM		0x0080	/*
234					 * Used for internal vm datastructures
235					 * only.
236					 */
237#define	UMA_ZONE_HASH		0x0100	/*
238					 * Use a hash table instead of caching
239					 * information in the vm_page.
240					 */
241#define	UMA_ZONE_SECONDARY	0x0200	/* Zone is a Secondary Zone */
242#define	UMA_ZONE_REFCNT		0x0400	/* Allocate refcnts in slabs */
243#define	UMA_ZONE_MAXBUCKET	0x0800	/* Use largest buckets */
244#define	UMA_ZONE_CACHESPREAD	0x1000	/*
245					 * Spread memory start locations across
246					 * all possible cache lines.  May
247					 * require many virtually contiguous
248					 * backend pages and can fail early.
249					 */
250#define	UMA_ZONE_VTOSLAB	0x2000	/* Zone uses vtoslab for lookup. */
251#define	UMA_ZONE_NODUMP		0x4000	/*
252					 * Zone's pages will not be included in
253					 * mini-dumps.
254					 */
255
256/*
257 * These flags are shared between the keg and zone.  In zones wishing to add
258 * new kegs these flags must be compatible.  Some are determined based on
259 * physical parameters of the request and may not be provided by the consumer.
260 */
261#define	UMA_ZONE_INHERIT						\
262    (UMA_ZONE_OFFPAGE | UMA_ZONE_MALLOC | UMA_ZONE_HASH |		\
263    UMA_ZONE_REFCNT | UMA_ZONE_VTOSLAB)
264
265/* Definitions for align */
266#define UMA_ALIGN_PTR	(sizeof(void *) - 1)	/* Alignment fit for ptr */
267#define UMA_ALIGN_LONG	(sizeof(long) - 1)	/* "" long */
268#define UMA_ALIGN_INT	(sizeof(int) - 1)	/* "" int */
269#define UMA_ALIGN_SHORT	(sizeof(short) - 1)	/* "" short */
270#define UMA_ALIGN_CHAR	(sizeof(char) - 1)	/* "" char */
271#define UMA_ALIGN_CACHE	(0 - 1)			/* Cache line size align */
272
273/*
274 * Destroys an empty uma zone.  If the zone is not empty uma complains loudly.
275 *
276 * Arguments:
277 *	zone  The zone we want to destroy.
278 *
279 */
280void uma_zdestroy(uma_zone_t zone);
281
282/*
283 * Allocates an item out of a zone
284 *
285 * Arguments:
286 *	zone  The zone we are allocating from
287 *	arg   This data is passed to the ctor function
288 *	flags See sys/malloc.h for available flags.
289 *
290 * Returns:
291 *	A non-null pointer to an initialized element from the zone is
292 *	guaranteed if the wait flag is M_WAITOK.  Otherwise a null pointer
293 *	may be returned if the zone is empty or the ctor failed.
294 */
295
296void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags);
297
298/*
299 * Allocates an item out of a zone without supplying an argument
300 *
301 * This is just a wrapper for uma_zalloc_arg for convenience.
302 *
303 */
304static __inline void *uma_zalloc(uma_zone_t zone, int flags);
305
306static __inline void *
307uma_zalloc(uma_zone_t zone, int flags)
308{
309	return uma_zalloc_arg(zone, NULL, flags);
310}
311
312/*
313 * Frees an item back into the specified zone.
314 *
315 * Arguments:
316 *	zone  The zone the item was originally allocated out of.
317 *	item  The memory to be freed.
318 *	arg   Argument passed to the destructor
319 *
320 * Returns:
321 *	Nothing.
322 */
323
324void uma_zfree_arg(uma_zone_t zone, void *item, void *arg);
325
326/*
327 * Frees an item back to a zone without supplying an argument
328 *
329 * This is just a wrapper for uma_zfree_arg for convenience.
330 *
331 */
332static __inline void uma_zfree(uma_zone_t zone, void *item);
333
334static __inline void
335uma_zfree(uma_zone_t zone, void *item)
336{
337	uma_zfree_arg(zone, item, NULL);
338}
339
340/*
341 * XXX The rest of the prototypes in this header are h0h0 magic for the VM.
342 * If you think you need to use it for a normal zone you're probably incorrect.
343 */
344
345/*
346 * Backend page supplier routines
347 *
348 * Arguments:
349 *	zone  The zone that is requesting pages.
350 *	size  The number of bytes being requested.
351 *	pflag Flags for these memory pages, see below.
352 *	wait  Indicates our willingness to block.
353 *
354 * Returns:
355 *	A pointer to the allocated memory or NULL on failure.
356 */
357
358typedef void *(*uma_alloc)(uma_zone_t zone, int size, u_int8_t *pflag, int wait);
359
360/*
361 * Backend page free routines
362 *
363 * Arguments:
364 *	item  A pointer to the previously allocated pages.
365 *	size  The original size of the allocation.
366 *	pflag The flags for the slab.  See UMA_SLAB_* below.
367 *
368 * Returns:
369 *	None
370 */
371typedef void (*uma_free)(void *item, int size, u_int8_t pflag);
372
373
374
375/*
376 * Sets up the uma allocator. (Called by vm_mem_init)
377 *
378 * Arguments:
379 *	bootmem  A pointer to memory used to bootstrap the system.
380 *
381 * Returns:
382 *	Nothing
383 *
384 * Discussion:
385 *	This memory is used for zones which allocate things before the
386 *	backend page supplier can give us pages.  It should be
387 *	UMA_SLAB_SIZE * boot_pages bytes. (see uma_int.h)
388 *
389 */
390
391void uma_startup(void *bootmem, int boot_pages);
392
393/*
394 * Finishes starting up the allocator.  This should
395 * be called when kva is ready for normal allocs.
396 *
397 * Arguments:
398 *	None
399 *
400 * Returns:
401 *	Nothing
402 *
403 * Discussion:
404 *	uma_startup2 is called by kmeminit() to enable us of uma for malloc.
405 */
406
407void uma_startup2(void);
408
409/*
410 * Reclaims unused memory for all zones
411 *
412 * Arguments:
413 *	None
414 * Returns:
415 *	None
416 *
417 * This should only be called by the page out daemon.
418 */
419
420void uma_reclaim(void);
421
422/*
423 * Sets the alignment mask to be used for all zones requesting cache
424 * alignment.  Should be called by MD boot code prior to starting VM/UMA.
425 *
426 * Arguments:
427 *	align The alignment mask
428 *
429 * Returns:
430 *	Nothing
431 */
432void uma_set_align(int align);
433
434/*
435 * Switches the backing object of a zone
436 *
437 * Arguments:
438 *	zone  The zone to update.
439 *	obj   The VM object to use for future allocations.
440 *	size  The size of the object to allocate.
441 *
442 * Returns:
443 *	0  if kva space can not be allocated
444 *	1  if successful
445 *
446 * Discussion:
447 *	A NULL object can be used and uma will allocate one for you.  Setting
448 *	the size will limit the amount of memory allocated to this zone.
449 *
450 */
451struct vm_object;
452int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int size);
453
454/*
455 * Sets a high limit on the number of items allowed in a zone
456 *
457 * Arguments:
458 *	zone  The zone to limit
459 *	nitems  The requested upper limit on the number of items allowed
460 *
461 * Returns:
462 *	int  The effective value of nitems after rounding up based on page size
463 */
464int uma_zone_set_max(uma_zone_t zone, int nitems);
465
466/*
467 * Obtains the effective limit on the number of items in a zone
468 *
469 * Arguments:
470 *	zone  The zone to obtain the effective limit from
471 *
472 * Return:
473 *	0  No limit
474 *	int  The effective limit of the zone
475 */
476int uma_zone_get_max(uma_zone_t zone);
477
478/*
479 * Obtains the approximate current number of items allocated from a zone
480 *
481 * Arguments:
482 *	zone  The zone to obtain the current allocation count from
483 *
484 * Return:
485 *	int  The approximate current number of items allocated from the zone
486 */
487int uma_zone_get_cur(uma_zone_t zone);
488
489/*
490 * The following two routines (uma_zone_set_init/fini)
491 * are used to set the backend init/fini pair which acts on an
492 * object as it becomes allocated and is placed in a slab within
493 * the specified zone's backing keg.  These should probably not
494 * be changed once allocations have already begun, but only be set
495 * immediately upon zone creation.
496 */
497void uma_zone_set_init(uma_zone_t zone, uma_init uminit);
498void uma_zone_set_fini(uma_zone_t zone, uma_fini fini);
499
500/*
501 * The following two routines (uma_zone_set_zinit/zfini) are
502 * used to set the zinit/zfini pair which acts on an object as
503 * it passes from the backing Keg's slab cache to the
504 * specified Zone's bucket cache.  These should probably not
505 * be changed once allocations have already begun, but only be set
506 * immediately upon zone creation.
507 */
508void uma_zone_set_zinit(uma_zone_t zone, uma_init zinit);
509void uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini);
510
511/*
512 * Replaces the standard page_alloc or obj_alloc functions for this zone
513 *
514 * Arguments:
515 *	zone   The zone whose backend allocator is being changed.
516 *	allocf A pointer to the allocation function
517 *
518 * Returns:
519 *	Nothing
520 *
521 * Discussion:
522 *	This could be used to implement pageable allocation, or perhaps
523 *	even DMA allocators if used in conjunction with the OFFPAGE
524 *	zone flag.
525 */
526
527void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf);
528
529/*
530 * Used for freeing memory provided by the allocf above
531 *
532 * Arguments:
533 *	zone  The zone that intends to use this free routine.
534 *	freef The page freeing routine.
535 *
536 * Returns:
537 *	Nothing
538 */
539
540void uma_zone_set_freef(uma_zone_t zone, uma_free freef);
541
542/*
543 * These flags are setable in the allocf and visible in the freef.
544 */
545#define UMA_SLAB_BOOT	0x01		/* Slab alloced from boot pages */
546#define UMA_SLAB_KMEM	0x02		/* Slab alloced from kmem_map */
547#define UMA_SLAB_KERNEL	0x04		/* Slab alloced from kernel_map */
548#define UMA_SLAB_PRIV	0x08		/* Slab alloced from priv allocator */
549#define UMA_SLAB_OFFP	0x10		/* Slab is managed separately  */
550#define UMA_SLAB_MALLOC	0x20		/* Slab is a large malloc slab */
551/* 0x40 and 0x80 are available */
552
553/*
554 * Used to pre-fill a zone with some number of items
555 *
556 * Arguments:
557 *	zone    The zone to fill
558 *	itemcnt The number of items to reserve
559 *
560 * Returns:
561 *	Nothing
562 *
563 * NOTE: This is blocking and should only be done at startup
564 */
565void uma_prealloc(uma_zone_t zone, int itemcnt);
566
567/*
568 * Used to lookup the reference counter allocated for an item
569 * from a UMA_ZONE_REFCNT zone.  For UMA_ZONE_REFCNT zones,
570 * reference counters are allocated for items and stored in
571 * the underlying slab header.
572 *
573 * Arguments:
574 * 	zone  The UMA_ZONE_REFCNT zone to which the item belongs.
575 *	item  The address of the item for which we want a refcnt.
576 *
577 * Returns:
578 * 	A pointer to a u_int32_t reference counter.
579 */
580u_int32_t *uma_find_refcnt(uma_zone_t zone, void *item);
581
582/*
583 * Used to determine if a fixed-size zone is exhausted.
584 *
585 * Arguments:
586 *	zone    The zone to check
587 *
588 * Returns:
589 * 	Non-zero if zone is exhausted.
590 */
591int uma_zone_exhausted(uma_zone_t zone);
592int uma_zone_exhausted_nolock(uma_zone_t zone);
593
594/*
595 * Exported statistics structures to be used by user space monitoring tools.
596 * Statistics stream consists of a uma_stream_header, followed by a series of
597 * alternative uma_type_header and uma_type_stat structures.
598 */
599#define	UMA_STREAM_VERSION	0x00000001
600struct uma_stream_header {
601	u_int32_t	ush_version;	/* Stream format version. */
602	u_int32_t	ush_maxcpus;	/* Value of MAXCPU for stream. */
603	u_int32_t	ush_count;	/* Number of records. */
604	u_int32_t	_ush_pad;	/* Pad/reserved field. */
605};
606
607#define	UTH_MAX_NAME	32
608#define	UTH_ZONE_SECONDARY	0x00000001
609struct uma_type_header {
610	/*
611	 * Static per-zone data, some extracted from the supporting keg.
612	 */
613	char		uth_name[UTH_MAX_NAME];
614	u_int32_t	uth_align;	/* Keg: alignment. */
615	u_int32_t	uth_size;	/* Keg: requested size of item. */
616	u_int32_t	uth_rsize;	/* Keg: real size of item. */
617	u_int32_t	uth_maxpages;	/* Keg: maximum number of pages. */
618	u_int32_t	uth_limit;	/* Keg: max items to allocate. */
619
620	/*
621	 * Current dynamic zone/keg-derived statistics.
622	 */
623	u_int32_t	uth_pages;	/* Keg: pages allocated. */
624	u_int32_t	uth_keg_free;	/* Keg: items free. */
625	u_int32_t	uth_zone_free;	/* Zone: items free. */
626	u_int32_t	uth_bucketsize;	/* Zone: desired bucket size. */
627	u_int32_t	uth_zone_flags;	/* Zone: flags. */
628	u_int64_t	uth_allocs;	/* Zone: number of allocations. */
629	u_int64_t	uth_frees;	/* Zone: number of frees. */
630	u_int64_t	uth_fails;	/* Zone: number of alloc failures. */
631	u_int64_t	uth_sleeps;	/* Zone: number of alloc sleeps. */
632	u_int64_t	_uth_reserved1[2];	/* Reserved. */
633};
634
635struct uma_percpu_stat {
636	u_int64_t	ups_allocs;	/* Cache: number of allocations. */
637	u_int64_t	ups_frees;	/* Cache: number of frees. */
638	u_int64_t	ups_cache_free;	/* Cache: free items in cache. */
639	u_int64_t	_ups_reserved[5];	/* Reserved. */
640};
641
642#endif
643