xref: /dragonfly/sys/sys/idr.h (revision 68b1c3c8)
1 /*
2  * Copyright (c) 2005-2012 The DragonFly Project.
3  * Copyright (c) 2013 François Tigeot
4  * All rights reserved.
5  *
6  * This code is derived from software contributed to The DragonFly Project
7  * by Jeffrey Hsu.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  * 3. Neither the name of The DragonFly Project nor the names of its
20  *    contributors may be used to endorse or promote products derived
21  *    from this software without specific, prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
26  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
27  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
28  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
29  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
31  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
33  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  */
37 
38 /**
39  * IDR is a small Integer ID management library that provides an interface to
40  * map integers with some pointer that can later be retrieved.
41  *
42  * NOTE: Maintains compatibility with linux, allowing NULL pointers.
43  */
44 
45 
46 #ifndef _SYS_IDR_H_
47 #define _SYS_IDR_H_
48 
49 #ifdef _KERNEL
50 
51 #include <sys/thread.h>
52 
53 struct idr_node {
54 	void	*data;
55 	int	 allocated;
56 };
57 
58 struct idr {
59 	struct	    idr_node *idr_nodes;
60 	int	    idr_count;
61 	int	    idr_lastindex;
62 	int	    idr_freeindex;
63 	int	    idr_nexpands;
64 	int	    idr_maxwant;
65 	struct lwkt_token idr_token;
66 };
67 
68 void	*idr_find(struct idr *idp, int id);
69 void	*idr_replace(struct idr *idp, void *ptr, int id);
70 void	*idr_remove(struct idr *idp, int id);
71 void	 idr_remove_all(struct idr *idp);
72 void	 idr_destroy(struct idr *idp);
73 int	 idr_for_each(struct idr *idp, int (*fn)(int id, void *p, void *data), void *data);
74 int	 idr_get_new(struct idr *idp, void *ptr, int *id);
75 int	 idr_get_new_above(struct idr *idp, void *ptr, int sid, int *id);
76 int	 idr_pre_get(struct idr *idp, unsigned gfp_mask);
77 
78 void	 idr_init(struct idr *idp);
79 
80 int idr_alloc(struct idr *idp, void *ptr, int start, int end, unsigned gfp_mask);
81 
idr_preload(unsigned gfp_mask)82 static inline void idr_preload(unsigned gfp_mask)
83 {
84 	/* Linux disables preemption and allocates a per-cpu buffer here */
85 }
86 
idr_preload_end(void)87 static inline void idr_preload_end(void)
88 {
89 	/* Linux re-enables preemption here */
90 }
91 
92 #endif /* _KERNEL */
93 
94 #endif /* !_SYS_IDR_H_ */
95