Greg Hartman | 76d05dc | 2016-11-23 15:51:27 -0800 | [diff] [blame] | 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 | |
| 19 | FILE_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 | */ |
| 37 | int 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 | */ |
| 73 | int 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 | */ |
| 88 | void 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 | } |