xref: /dragonfly/sys/dev/drm/include/linux/idr.h (revision a3127495)
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 MALLOC_DECLARE(M_IDR);
33 
34 #define	IDA_CHUNK_SIZE		128	/* 128 bytes per chunk */
35 #define	IDA_BITMAP_LONGS	(IDA_CHUNK_SIZE / sizeof(long) - 1)
36 #define	IDA_BITMAP_BITS 	(IDA_BITMAP_LONGS * sizeof(long) * 8)
37 
38 struct ida_bitmap {
39 	long			nr_busy;
40 	unsigned long		bitmap[IDA_BITMAP_LONGS];
41 };
42 
43 struct ida {
44 	struct idr		idr;
45 	struct ida_bitmap	*free_bitmap;
46 };
47 
48 static inline void
49 ida_init(struct ida *ida)
50 {
51 	idr_init(&ida->idr);
52 }
53 
54 static inline void
55 ida_simple_remove(struct ida *ida, unsigned int id)
56 {
57 	idr_remove(&ida->idr, id);
58 }
59 
60 static inline void
61 ida_remove(struct ida *ida, int id)
62 {
63 	idr_remove(&ida->idr, id);
64 }
65 
66 static inline void
67 ida_destroy(struct ida *ida)
68 {
69 	idr_destroy(&ida->idr);
70 	if (ida->free_bitmap != NULL) {
71 		/* kfree() is a linux macro! Work around the cpp pass */
72 		(kfree)(ida->free_bitmap, M_IDR);
73 	}
74 }
75 
76 static inline int
77 ida_simple_get(struct ida *ida, unsigned int start, unsigned int end, gfp_t gfp_mask)
78 {
79 	int id;
80 	unsigned int lim;
81 
82 	if ((end == 0) || (end > 0x80000000))
83 		lim = 0x80000000;
84 	else
85 		lim = end - 1;
86 
87 	idr_preload(gfp_mask);
88 	id = idr_alloc(&ida->idr, NULL, start, lim, gfp_mask);
89 	idr_preload_end();
90 
91 	return id;
92 }
93 
94 #endif	/* _LINUX_IDR_H_ */
95