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| /* |
| * Copyright (C) 2006 Jakub Jermar |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** @addtogroup genericadt |
| * @{ |
| */ |
| /** |
| * @file |
| * @brief Implementation of bitmap ADT. |
| * |
| * This file implements bitmap ADT and provides functions for |
| * setting and clearing ranges of bits. |
| */ |
| |
| #include <adt/bitmap.h> |
| #include <typedefs.h> |
| #include <arch/types.h> |
| #include <align.h> |
| #include <debug.h> |
| #include <macros.h> |
| |
| #define ALL_ONES 0xff |
| #define ALL_ZEROES 0x00 |
| |
| /** Initialize bitmap. |
| * |
| * No portion of the bitmap is set or cleared by this function. |
| * |
| * @param bitmap Bitmap structure. |
| * @param map Address of the memory used to hold the map. |
| * @param bits Number of bits stored in bitmap. |
| */ |
| void bitmap_initialize(bitmap_t *bitmap, uint8_t *map, count_t bits) |
| { |
| bitmap->map = map; |
| bitmap->bits = bits; |
| } |
| |
| /** Set range of bits. |
| * |
| * @param bitmap Bitmap structure. |
| * @param start Starting bit. |
| * @param bits Number of bits to set. |
| */ |
| void bitmap_set_range(bitmap_t *bitmap, index_t start, count_t bits) |
| { |
| index_t i=0; |
| index_t aligned_start; |
| count_t lub; /* leading unaligned bits */ |
| count_t amb; /* aligned middle bits */ |
| count_t tab; /* trailing aligned bits */ |
| |
| ASSERT(start + bits <= bitmap->bits); |
| |
| aligned_start = ALIGN_UP(start, 8); |
| lub = min(aligned_start - start, bits); |
| amb = bits > lub ? bits - lub : 0; |
| tab = amb % 8; |
| |
| if ( start + bits < aligned_start ) { |
| /* |
| * Set bits in the middle of byte |
| */ |
| bitmap->map[start / 8] |= ((1 << lub)-1) << (start&7); |
| return; |
| } |
| |
| if (lub) { |
| /* |
| * Make sure to set any leading unaligned bits. |
| */ |
| bitmap->map[start / 8] |= ~((1 << (8 - lub)) - 1); |
| } |
| for (i = 0; i < amb / 8; i++) { |
| /* |
| * The middle bits can be set byte by byte. |
| */ |
| bitmap->map[aligned_start / 8 + i] = ALL_ONES; |
| } |
| if (tab) { |
| /* |
| * Make sure to set any trailing aligned bits. |
| */ |
| bitmap->map[aligned_start / 8 + i] |= (1 << tab) - 1; |
| } |
| |
| } |
| |
| /** Clear range of bits. |
| * |
| * @param bitmap Bitmap structure. |
| * @param start Starting bit. |
| * @param bits Number of bits to clear. |
| */ |
| void bitmap_clear_range(bitmap_t *bitmap, index_t start, count_t bits) |
| { |
| index_t i=0; |
| index_t aligned_start; |
| count_t lub; /* leading unaligned bits */ |
| count_t amb; /* aligned middle bits */ |
| count_t tab; /* trailing aligned bits */ |
| |
| ASSERT(start + bits <= bitmap->bits); |
| |
| aligned_start = ALIGN_UP(start, 8); |
| lub = min(aligned_start - start, bits); |
| amb = bits > lub ? bits - lub : 0; |
| tab = amb % 8; |
| |
| if ( start + bits < aligned_start ) |
| { |
| /* |
| * Set bits in the middle of byte |
| */ |
| bitmap->map[start / 8] &= ~(((1 << lub)-1) << (start&7)); |
| return; |
| } |
| |
| |
| if (lub) { |
| /* |
| * Make sure to clear any leading unaligned bits. |
| */ |
| bitmap->map[start / 8] &= (1 << (8 - lub)) - 1; |
| } |
| for (i = 0; i < amb / 8; i++) { |
| /* |
| * The middle bits can be cleared byte by byte. |
| */ |
| bitmap->map[aligned_start / 8 + i] = ALL_ZEROES; |
| } |
| if (tab) { |
| /* |
| * Make sure to clear any trailing aligned bits. |
| */ |
| bitmap->map[aligned_start / 8 + i] &= ~((1 << tab) - 1); |
| } |
| |
| } |
| |
| /** Copy portion of one bitmap into another bitmap. |
| * |
| * @param dst Destination bitmap. |
| * @param src Source bitmap. |
| * @param bits Number of bits to copy. |
| */ |
| void bitmap_copy(bitmap_t *dst, bitmap_t *src, count_t bits) |
| { |
| index_t i; |
| |
| ASSERT(bits <= dst->bits); |
| ASSERT(bits <= src->bits); |
| |
| for (i = 0; i < bits / 8; i++) |
| dst->map[i] = src->map[i]; |
| |
| if (bits % 8) { |
| bitmap_clear_range(dst, i * 8, bits % 8); |
| dst->map[i] |= src->map[i] & ((1 << (bits % 8)) - 1); |
| } |
| } |
| |
| /** @} |
| */ |