1/*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013-2016 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#ifndef	_LINUXKPI_LINUX_IDR_H_
30#define	_LINUXKPI_LINUX_IDR_H_
31
32#include <sys/param.h>
33#include <sys/lock.h>
34#include <sys/limits.h>
35#include <sys/mutex.h>
36
37#include <linux/types.h>
38
39#define	IDR_BITS	5
40#define	IDR_SIZE	(1 << IDR_BITS)
41#define	IDR_MASK	(IDR_SIZE - 1)
42
43#define	MAX_ID_SHIFT	((sizeof(int) * NBBY) - 1)
44#define	MAX_ID_BIT	(1U << MAX_ID_SHIFT)
45#define	MAX_ID_MASK	(MAX_ID_BIT - 1)
46#define	MAX_LEVEL	(MAX_ID_SHIFT + IDR_BITS - 1) / IDR_BITS
47
48#define MAX_IDR_SHIFT (sizeof(int)*8 - 1)
49#define MAX_IDR_BIT (1U << MAX_IDR_SHIFT)
50#define MAX_IDR_MASK (MAX_IDR_BIT - 1)
51
52struct idr_layer {
53	unsigned long		bitmap;
54	struct idr_layer	*ary[IDR_SIZE];
55};
56
57struct idr {
58	struct mtx		lock;
59	struct idr_layer	*top;
60	struct idr_layer	*free;
61	int			layers;
62	int			next_cyclic_id;
63};
64
65/* NOTE: It is the applications responsibility to destroy the IDR */
66#define	DEFINE_IDR(name)						\
67	struct idr name;						\
68	SYSINIT(name##_idr_sysinit, SI_SUB_DRIVERS, SI_ORDER_FIRST,	\
69	    idr_init, &(name))
70
71/* NOTE: It is the applications responsibility to destroy the IDA */
72#define	DEFINE_IDA(name)						\
73	struct ida name;						\
74	SYSINIT(name##_ida_sysinit, SI_SUB_DRIVERS, SI_ORDER_FIRST,	\
75	    ida_init, &(name))
76
77void	idr_preload(gfp_t gfp_mask);
78void	idr_preload_end(void);
79void	*idr_find(struct idr *idp, int id);
80void	*idr_get_next(struct idr *idp, int *nextid);
81bool	idr_is_empty(struct idr *idp);
82int	idr_pre_get(struct idr *idp, gfp_t gfp_mask);
83int	idr_get_new(struct idr *idp, void *ptr, int *id);
84int	idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id);
85void	*idr_replace(struct idr *idp, void *ptr, int id);
86void	*idr_remove(struct idr *idp, int id);
87void	idr_remove_all(struct idr *idp);
88void	idr_destroy(struct idr *idp);
89void	idr_init(struct idr *idp);
90int	idr_alloc(struct idr *idp, void *ptr, int start, int end, gfp_t);
91int	idr_alloc_cyclic(struct idr *idp, void *ptr, int start, int end, gfp_t);
92int	idr_for_each(struct idr *idp, int (*fn)(int id, void *p, void *data), void *data);
93
94#define	idr_for_each_entry(idp, entry, id)	\
95	for ((id) = 0; ((entry) = idr_get_next(idp, &(id))) != NULL; ++(id))
96
97#define	IDA_CHUNK_SIZE		128	/* 128 bytes per chunk */
98#define	IDA_BITMAP_LONGS	(IDA_CHUNK_SIZE / sizeof(long) - 1)
99#define	IDA_BITMAP_BITS		(IDA_BITMAP_LONGS * sizeof(long) * 8)
100
101struct ida_bitmap {
102	long			nr_busy;
103	unsigned long		bitmap[IDA_BITMAP_LONGS];
104};
105
106struct ida {
107	struct idr		idr;
108	struct ida_bitmap	*free_bitmap;
109};
110
111int	ida_pre_get(struct ida *ida, gfp_t gfp_mask);
112int	ida_get_new_above(struct ida *ida, int starting_id, int *p_id);
113void	ida_remove(struct ida *ida, int id);
114void	ida_destroy(struct ida *ida);
115void	ida_init(struct ida *ida);
116
117int	ida_simple_get(struct ida *ida, unsigned int start, unsigned int end,
118    gfp_t gfp_mask);
119void	ida_simple_remove(struct ida *ida, unsigned int id);
120
121static inline void
122ida_free(struct ida *ida, int id)
123{
124
125	ida_remove(ida, id);
126}
127
128static inline int
129ida_get_new(struct ida *ida, int *p_id)
130{
131
132	return (ida_get_new_above(ida, 0, p_id));
133}
134
135static inline int
136ida_alloc_min(struct ida *ida, unsigned int min, gfp_t gfp)
137{
138	return (ida_simple_get(ida, min, UINT_MAX, gfp));
139}
140
141static inline int
142ida_alloc_max(struct ida *ida, unsigned int max, gfp_t gfp)
143{
144
145	return (ida_simple_get(ida, 0, max, gfp));
146}
147
148static inline int ida_alloc(struct ida *ida, gfp_t gfp)
149{
150	return (ida_alloc_max(ida, ~0u, gfp));
151}
152
153static inline bool
154ida_is_empty(struct ida *ida)
155{
156
157	return (idr_is_empty(&ida->idr));
158}
159
160#endif	/* _LINUXKPI_LINUX_IDR_H_ */
161