2 * Copyright (c) 2009 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Alex Hornung <ahornung@gmail.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/types.h>
38 #include <machine/limits.h>
39 #include <sys/devfs.h>
41 MALLOC_DECLARE(M_DEVFS);
44 * DEVFS clone bitmap functions
47 devfs_clone_bitmap_init(struct devfs_bitmap *bitmap)
49 bitmap->chunks = DEVFS_BITMAP_INITIAL_SIZE;
50 bitmap->bitmap = kmalloc(bitmap->chunks * sizeof(u_long),
52 memset(bitmap->bitmap, -1, bitmap->chunks * sizeof(u_long));
57 devfs_clone_bitmap_uninit(struct devfs_bitmap *bitmap)
59 kfree(bitmap->bitmap, M_DEVFS);
64 devfs_clone_bitmap_resize(struct devfs_bitmap *bitmap, int newchunks)
66 int oldchunks = bitmap->chunks;
68 bitmap->chunks = newchunks + 2;
69 bitmap->bitmap = krealloc(bitmap->bitmap,
70 sizeof(u_long) * bitmap->chunks,
72 memset(bitmap->bitmap + oldchunks, -1,
73 sizeof(u_long) * (bitmap->chunks - oldchunks));
78 devfs_clone_bitmap_fff(struct devfs_bitmap *bitmap)
84 chunks = bitmap->chunks;
86 for (i = 0; i < chunks + 1; i++) {
88 devfs_clone_bitmap_resize(bitmap, i);
89 curbitmap = bitmap->bitmap[i];
92 curbitmap &= (~curbitmap)+1;
93 for (bit = 1; curbitmap != 1; bit++)
96 return (bit - 1 + (i << 3) * sizeof(curbitmap));
103 panic("devfs_clone_bitmap_fff");
108 * Caller wants to know if the specified unit has been allocated
109 * or not. Return 0, indicating that it has not been allocated.
111 * (the bitmap implements 0=allocated, 1=not-allocated but the
112 * return value is inverted).
115 devfs_clone_bitmap_chk(struct devfs_bitmap *bitmap, int unit)
119 chunk = unit / (sizeof(u_long) * 8);
120 unit -= chunk * (sizeof(u_long) * 8);
122 if (chunk >= bitmap->chunks)
123 return 0; /* device does not exist */
125 return !((bitmap->bitmap[chunk]) & (1L << unit));
130 devfs_clone_bitmap_set(struct devfs_bitmap *bitmap, int unit)
134 chunk = unit / (sizeof(u_long) * 8);
135 unit -= chunk * (sizeof(u_long) * 8);
137 if (chunk >= bitmap->chunks)
138 devfs_clone_bitmap_resize(bitmap, chunk);
139 bitmap->bitmap[chunk] &= ~(1<<unit);
143 * Deallocate a unit number. We must synchronize any destroy_dev()'s
144 * the device called before we clear the bitmap bit to avoid races
145 * against a new clone.
148 devfs_clone_bitmap_put(struct devfs_bitmap *bitmap, int unit)
154 chunk = unit / (sizeof(u_long) * 8);
155 unit -= chunk * (sizeof(u_long) * 8);
157 if (chunk >= bitmap->chunks)
159 bitmap->bitmap[chunk] |= (1L << unit);
163 * Allocate a unit number for a device
166 devfs_clone_bitmap_get(struct devfs_bitmap *bitmap, int limit)
170 unit = devfs_clone_bitmap_fff(bitmap);
171 if ((limit > 0) && (unit > limit))
173 devfs_clone_bitmap_set(bitmap, unit);