idr.h revision 271127 
1/*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013 Mellanox Technologies, Ltd.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice unmodified, this list of conditions, and the following
13 *    disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#ifndef	_LINUX_IDR_H_
31#define	_LINUX_IDR_H_
32
33#include <sys/kernel.h>
34
35#define	IDR_BITS	5
36#define	IDR_SIZE	(1 << IDR_BITS)
37#define	IDR_MASK	(IDR_SIZE - 1)
38
39#define	MAX_ID_SHIFT	((sizeof(int) * NBBY) - 1)
40#define	MAX_ID_BIT	(1U << MAX_ID_SHIFT)
41#define	MAX_ID_MASK	(MAX_ID_BIT - 1)
42#define	MAX_LEVEL	(MAX_ID_SHIFT + IDR_BITS - 1) / IDR_BITS
43
44#define MAX_IDR_SHIFT (sizeof(int)*8 - 1)
45#define MAX_IDR_BIT (1U << MAX_IDR_SHIFT)
46#define MAX_IDR_MASK (MAX_IDR_BIT - 1)
47
48struct idr_layer {
49	unsigned long		bitmap;
50	struct idr_layer	*ary[IDR_SIZE];
51};
52
53struct idr {
54	struct mtx		lock;
55	struct idr_layer	*top;
56	struct idr_layer	*free;
57	int			layers;
58};
59
60#define DEFINE_IDR(name)						\
61	struct idr name;						\
62	SYSINIT(name##_idr_sysinit, SI_SUB_DRIVERS, SI_ORDER_FIRST,	\
63	    idr_init, &(name));
64
65void	*idr_find(struct idr *idp, int id);
66int	idr_pre_get(struct idr *idp, gfp_t gfp_mask);
67int	idr_get_new(struct idr *idp, void *ptr, int *id);
68int	idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id);
69void	*idr_replace(struct idr *idp, void *ptr, int id);
70void	idr_remove(struct idr *idp, int id);
71void	idr_remove_all(struct idr *idp);
72void	idr_destroy(struct idr *idp);
73void	idr_init(struct idr *idp);
74
75#endif	/* _LINUX_IDR_H_ */
76