1/*
2 * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19FILE_LICENCE ( GPL2_OR_LATER );
20
21#include <errno.h>
22#include <gpxe/bitmap.h>
23
24/** @file
25 *
26 * Bitmaps for multicast downloads
27 *
28 */
29
30/**
31 * Resize bitmap
32 *
33 * @v bitmap		Bitmap
34 * @v new_length	New length of bitmap, in bits
35 * @ret rc		Return status code
36 */
37int bitmap_resize ( struct bitmap *bitmap, unsigned int new_length ) {
38	unsigned int old_num_blocks;
39	unsigned int new_num_blocks;
40	size_t new_size;
41	bitmap_block_t *new_blocks;
42
43	old_num_blocks = BITMAP_INDEX ( bitmap->length + BITMAP_BLKSIZE - 1 );
44	new_num_blocks = BITMAP_INDEX ( new_length + BITMAP_BLKSIZE - 1 );
45
46	if ( old_num_blocks != new_num_blocks ) {
47		new_size = ( new_num_blocks * sizeof ( bitmap->blocks[0] ) );
48		new_blocks = realloc ( bitmap->blocks, new_size );
49		if ( ! new_blocks ) {
50			DBGC ( bitmap, "Bitmap %p could not resize to %d "
51			       "bits\n", bitmap, new_length );
52			return -ENOMEM;
53		}
54		bitmap->blocks = new_blocks;
55	}
56	bitmap->length = new_length;
57
58	while ( old_num_blocks < new_num_blocks ) {
59		bitmap->blocks[old_num_blocks++] = 0;
60	}
61
62	DBGC ( bitmap, "Bitmap %p resized to %d bits\n", bitmap, new_length );
63	return 0;
64}
65
66/**
67 * Test bit in bitmap
68 *
69 * @v bitmap		Bitmap
70 * @v bit		Bit index
71 * @ret is_set		Bit is set
72 */
73int bitmap_test ( struct bitmap *bitmap, unsigned int bit ) {
74	unsigned int index = BITMAP_INDEX ( bit );
75        bitmap_block_t mask = BITMAP_MASK ( bit );
76
77	if ( bit >= bitmap->length )
78		return 0;
79	return ( bitmap->blocks[index] & mask );
80}
81
82/**
83 * Set bit in bitmap
84 *
85 * @v bitmap		Bitmap
86 * @v bit		Bit index
87 */
88void bitmap_set ( struct bitmap *bitmap, unsigned int bit ) {
89	unsigned int index = BITMAP_INDEX ( bit );
90        bitmap_block_t mask = BITMAP_MASK ( bit );
91
92	DBGC ( bitmap, "Bitmap %p setting bit %d\n", bitmap, bit );
93
94	/* Update bitmap */
95	bitmap->blocks[index] |= mask;
96
97	/* Update first gap counter */
98	while ( bitmap_test ( bitmap, bitmap->first_gap ) ) {
99		bitmap->first_gap++;
100	}
101}
102