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/radix-tree.h>
38 #include <linux/gpf.h>
39 #include <linux/types.h>
40
41 #define IDR_BITS 5
42 #define IDR_SIZE (1 << IDR_BITS)
43 #define IDR_MASK (IDR_SIZE - 1)
44
45 #define MAX_ID_SHIFT ((sizeof(int) * NBBY) - 1)
46 #define MAX_ID_BIT (1U << MAX_ID_SHIFT)
47 #define MAX_ID_MASK (MAX_ID_BIT - 1)
48 #define MAX_LEVEL (MAX_ID_SHIFT + IDR_BITS - 1) / IDR_BITS
49
50 #define MAX_IDR_SHIFT (sizeof(int)*8 - 1)
51 #define MAX_IDR_BIT (1U << MAX_IDR_SHIFT)
52 #define MAX_IDR_MASK (MAX_IDR_BIT - 1)
53
54 struct idr_layer {
55 unsigned long bitmap;
56 struct idr_layer *ary[IDR_SIZE];
57 };
58
59 struct idr {
60 struct mtx lock;
61 struct idr_layer *top;
62 struct idr_layer *free;
63 int layers;
64 int next_cyclic_id;
65 };
66
67 /* NOTE: It is the applications responsibility to destroy the IDR */
68 #define DEFINE_IDR(name) \
69 struct idr name; \
70 SYSINIT(name##_idr_sysinit, SI_SUB_DRIVERS, SI_ORDER_FIRST, \
71 idr_init, &(name))
72
73 /* NOTE: It is the applications responsibility to destroy the IDA */
74 #define DEFINE_IDA(name) \
75 struct ida name; \
76 SYSINIT(name##_ida_sysinit, SI_SUB_DRIVERS, SI_ORDER_FIRST, \
77 ida_init, &(name))
78
79 void idr_preload(gfp_t gfp_mask);
80 void idr_preload_end(void);
81 void *idr_find(struct idr *idp, int id);
82 void *idr_get_next(struct idr *idp, int *nextid);
83 bool idr_is_empty(struct idr *idp);
84 int idr_pre_get(struct idr *idp, gfp_t gfp_mask);
85 int idr_get_new(struct idr *idp, void *ptr, int *id);
86 int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id);
87 void *idr_replace(struct idr *idp, void *ptr, int id);
88 void *idr_remove(struct idr *idp, int id);
89 void idr_remove_all(struct idr *idp);
90 void idr_destroy(struct idr *idp);
91 void idr_init(struct idr *idp);
92 int idr_alloc(struct idr *idp, void *ptr, int start, int end, gfp_t);
93 int idr_alloc_cyclic(struct idr *idp, void *ptr, int start, int end, gfp_t);
94 int idr_for_each(struct idr *idp, int (*fn)(int id, void *p, void *data), void *data);
95
96 #define idr_for_each_entry(idp, entry, id) \
97 for ((id) = 0; ((entry) = idr_get_next(idp, &(id))) != NULL; ++(id))
98
99 #define IDA_CHUNK_SIZE 128 /* 128 bytes per chunk */
100 #define IDA_BITMAP_LONGS (IDA_CHUNK_SIZE / sizeof(long) - 1)
101 #define IDA_BITMAP_BITS (IDA_BITMAP_LONGS * sizeof(long) * 8)
102
103 struct ida_bitmap {
104 long nr_busy;
105 unsigned long bitmap[IDA_BITMAP_LONGS];
106 };
107
108 struct ida {
109 struct idr idr;
110 struct ida_bitmap *free_bitmap;
111 };
112
113 int ida_pre_get(struct ida *ida, gfp_t gfp_mask);
114 int ida_get_new_above(struct ida *ida, int starting_id, int *p_id);
115 void ida_remove(struct ida *ida, int id);
116 void ida_destroy(struct ida *ida);
117 void ida_init(struct ida *ida);
118
119 int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end,
120 gfp_t gfp_mask);
121 void ida_simple_remove(struct ida *ida, unsigned int id);
122
123 static inline void
ida_free(struct ida * ida,int id)124 ida_free(struct ida *ida, int id)
125 {
126
127 ida_remove(ida, id);
128 }
129
130 static inline int
ida_get_new(struct ida * ida,int * p_id)131 ida_get_new(struct ida *ida, int *p_id)
132 {
133
134 return (ida_get_new_above(ida, 0, p_id));
135 }
136
137 static inline int
ida_alloc_min(struct ida * ida,unsigned int min,gfp_t gfp)138 ida_alloc_min(struct ida *ida, unsigned int min, gfp_t gfp)
139 {
140 return (ida_simple_get(ida, min, UINT_MAX, gfp));
141 }
142
143 static inline int
ida_alloc_max(struct ida * ida,unsigned int max,gfp_t gfp)144 ida_alloc_max(struct ida *ida, unsigned int max, gfp_t gfp)
145 {
146
147 return (ida_simple_get(ida, 0, max, gfp));
148 }
149
ida_alloc(struct ida * ida,gfp_t gfp)150 static inline int ida_alloc(struct ida *ida, gfp_t gfp)
151 {
152 return (ida_alloc_max(ida, ~0u, gfp));
153 }
154
155 static inline bool
ida_is_empty(struct ida * ida)156 ida_is_empty(struct ida *ida)
157 {
158
159 return (idr_is_empty(&ida->idr));
160 }
161
162 #endif /* _LINUXKPI_LINUX_IDR_H_ */
163