xref: /dragonfly/sys/dev/drm/include/linux/idr.h (revision 335b9e93)
1 /*
2  * Copyright (c) 2013-2016 François Tigeot
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #ifndef _LINUX_IDR_H_
28 #define _LINUX_IDR_H_
29 
30 #include <sys/idr.h>
31 
32 #ifdef MALLOC_DECLARE
33 MALLOC_DECLARE(M_IDR);
34 #endif
35 
36 #define	IDA_CHUNK_SIZE		128	/* 128 bytes per chunk */
37 #define	IDA_BITMAP_LONGS	(IDA_CHUNK_SIZE / sizeof(long) - 1)
38 #define	IDA_BITMAP_BITS 	(IDA_BITMAP_LONGS * sizeof(long) * 8)
39 
40 struct ida_bitmap {
41 	long			nr_busy;
42 	unsigned long		bitmap[IDA_BITMAP_LONGS];
43 };
44 
45 struct ida {
46 	struct idr		idr;
47 	struct ida_bitmap	*free_bitmap;
48 };
49 
50 static inline void
51 ida_init(struct ida *ida)
52 {
53 	idr_init(&ida->idr);
54 }
55 
56 static inline void
57 ida_simple_remove(struct ida *ida, unsigned int id)
58 {
59 	idr_remove(&ida->idr, id);
60 }
61 
62 static inline void
63 ida_remove(struct ida *ida, int id)
64 {
65 	idr_remove(&ida->idr, id);
66 }
67 
68 static inline void
69 ida_destroy(struct ida *ida)
70 {
71 	idr_destroy(&ida->idr);
72 	if (ida->free_bitmap != NULL) {
73 		/* kfree() is a linux macro! Work around the cpp pass */
74 		(kfree)(ida->free_bitmap, M_IDR);
75 	}
76 }
77 
78 static inline int
79 ida_simple_get(struct ida *ida, unsigned int start, unsigned int end, gfp_t gfp_mask)
80 {
81 	int id;
82 	unsigned int lim;
83 
84 	if ((end == 0) || (end > 0x80000000))
85 		lim = 0x80000000;
86 	else
87 		lim = end - 1;
88 
89 	idr_preload(gfp_mask);
90 	id = idr_alloc(&ida->idr, NULL, start, lim, gfp_mask);
91 	idr_preload_end();
92 
93 	return id;
94 }
95 
96 static inline void *
97 idr_get_next(struct idr *idp, int *nextid)
98 {
99 	void *res = NULL;
100 
101 	lwkt_gettoken(&idp->idr_token);
102 
103 	for (int id = *nextid; id < idp->idr_count; id++) {
104 		res = idr_find(idp, id);
105 		if (res == NULL)
106 			continue;
107 		*nextid = id;
108 		break;
109 	}
110 
111 	lwkt_reltoken(&idp->idr_token);
112 	return res;
113 }
114 
115 #define idr_for_each_entry(idp, entry, id)			\
116 	for (id = 0; ((entry) = idr_get_next(idp, &(id))) != NULL; ++id)
117 
118 #endif	/* _LINUX_IDR_H_ */
119