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
52 struct idr_layer {
53 unsigned long bitmap;
54 struct idr_layer *ary[IDR_SIZE];
55 };
56
57 struct 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
77 void idr_preload(gfp_t gfp_mask);
78 void idr_preload_end(void);
79 void *idr_find(struct idr *idp, int id);
80 void *idr_get_next(struct idr *idp, int *nextid);
81 bool idr_is_empty(struct idr *idp);
82 int idr_pre_get(struct idr *idp, gfp_t gfp_mask);
83 int idr_get_new(struct idr *idp, void *ptr, int *id);
84 int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id);
85 void *idr_replace(struct idr *idp, void *ptr, int id);
86 void *idr_remove(struct idr *idp, int id);
87 void idr_remove_all(struct idr *idp);
88 void idr_destroy(struct idr *idp);
89 void idr_init(struct idr *idp);
90 int idr_alloc(struct idr *idp, void *ptr, int start, int end, gfp_t);
91 int idr_alloc_cyclic(struct idr *idp, void *ptr, int start, int end, gfp_t);
92 int 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
101 struct ida_bitmap {
102 long nr_busy;
103 unsigned long bitmap[IDA_BITMAP_LONGS];
104 };
105
106 struct ida {
107 struct idr idr;
108 struct ida_bitmap *free_bitmap;
109 };
110
111 int ida_pre_get(struct ida *ida, gfp_t gfp_mask);
112 int ida_get_new_above(struct ida *ida, int starting_id, int *p_id);
113 void ida_remove(struct ida *ida, int id);
114 void ida_destroy(struct ida *ida);
115 void ida_init(struct ida *ida);
116
117 int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end,
118 gfp_t gfp_mask);
119 void ida_simple_remove(struct ida *ida, unsigned int id);
120
121 static inline void
ida_free(struct ida * ida,int id)122 ida_free(struct ida *ida, int id)
123 {
124
125 ida_remove(ida, id);
126 }
127
128 static inline int
ida_get_new(struct ida * ida,int * p_id)129 ida_get_new(struct ida *ida, int *p_id)
130 {
131
132 return (ida_get_new_above(ida, 0, p_id));
133 }
134
135 static inline int
ida_alloc_min(struct ida * ida,unsigned int min,gfp_t gfp)136 ida_alloc_min(struct ida *ida, unsigned int min, gfp_t gfp)
137 {
138 return (ida_simple_get(ida, min, UINT_MAX, gfp));
139 }
140
141 static inline int
ida_alloc_max(struct ida * ida,unsigned int max,gfp_t gfp)142 ida_alloc_max(struct ida *ida, unsigned int max, gfp_t gfp)
143 {
144
145 return (ida_simple_get(ida, 0, max, gfp));
146 }
147
ida_alloc(struct ida * ida,gfp_t gfp)148 static inline int ida_alloc(struct ida *ida, gfp_t gfp)
149 {
150 return (ida_alloc_max(ida, ~0u, gfp));
151 }
152
153 static inline bool
ida_is_empty(struct ida * ida)154 ida_is_empty(struct ida *ida)
155 {
156
157 return (idr_is_empty(&ida->idr));
158 }
159
160 #endif /* _LINUXKPI_LINUX_IDR_H_ */
161