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