/* * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ FILE_LICENCE ( GPL2_OR_LATER ); #include <errno.h> #include <gpxe/bitmap.h> /** @file * * Bitmaps for multicast downloads * */ /** * Resize bitmap * * @v bitmap Bitmap * @v new_length New length of bitmap, in bits * @ret rc Return status code */ int bitmap_resize ( struct bitmap *bitmap, unsigned int new_length ) { unsigned int old_num_blocks; unsigned int new_num_blocks; size_t new_size; bitmap_block_t *new_blocks; old_num_blocks = BITMAP_INDEX ( bitmap->length + BITMAP_BLKSIZE - 1 ); new_num_blocks = BITMAP_INDEX ( new_length + BITMAP_BLKSIZE - 1 ); if ( old_num_blocks != new_num_blocks ) { new_size = ( new_num_blocks * sizeof ( bitmap->blocks[0] ) ); new_blocks = realloc ( bitmap->blocks, new_size ); if ( ! new_blocks ) { DBGC ( bitmap, "Bitmap %p could not resize to %d " "bits\n", bitmap, new_length ); return -ENOMEM; } bitmap->blocks = new_blocks; } bitmap->length = new_length; while ( old_num_blocks < new_num_blocks ) { bitmap->blocks[old_num_blocks++] = 0; } DBGC ( bitmap, "Bitmap %p resized to %d bits\n", bitmap, new_length ); return 0; } /** * Test bit in bitmap * * @v bitmap Bitmap * @v bit Bit index * @ret is_set Bit is set */ int bitmap_test ( struct bitmap *bitmap, unsigned int bit ) { unsigned int index = BITMAP_INDEX ( bit ); bitmap_block_t mask = BITMAP_MASK ( bit ); if ( bit >= bitmap->length ) return 0; return ( bitmap->blocks[index] & mask ); } /** * Set bit in bitmap * * @v bitmap Bitmap * @v bit Bit index */ void bitmap_set ( struct bitmap *bitmap, unsigned int bit ) { unsigned int index = BITMAP_INDEX ( bit ); bitmap_block_t mask = BITMAP_MASK ( bit ); DBGC ( bitmap, "Bitmap %p setting bit %d\n", bitmap, bit ); /* Update bitmap */ bitmap->blocks[index] |= mask; /* Update first gap counter */ while ( bitmap_test ( bitmap, bitmap->first_gap ) ) { bitmap->first_gap++; } }