0,0 → 1,152 |
/* |
* 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. |
*/ |
|
#include <adt/bitmap.h> |
#include <typedefs.h> |
#include <arch/types.h> |
#include <align.h> |
#include <debug.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, __u8 *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; |
index_t aligned_start; |
count_t lub; /* leading unaligned bits */ |
count_t tub; /* trailing unaligned bits */ |
|
ASSERT(start + bits <= bitmap->bits); |
|
aligned_start = ALIGN_UP(start, 8); |
lub = aligned_start - start; |
tub = (bits - lub) % 8; |
|
if (lub) { |
/* |
* Make sure to set any leading unaligned bits. |
*/ |
bitmap->map[start / 8] |= ~((1 << (8 - lub)) - 1); |
} |
for (i = 0; i < (bits - lub) / 8; i++) { |
/* |
* The middle bits can be set byte by byte. |
*/ |
bitmap->map[aligned_start / 8 + i] = ALL_ONES; |
} |
if (tub) { |
/* |
* Make sure to set any trailing unaligned bits. |
*/ |
bitmap->map[aligned_start / 8 + i] |= (1 << tub) - 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; |
index_t aligned_start; |
count_t lub; /* leading unaligned bits */ |
count_t tub; /* trailing unaligned bits */ |
|
ASSERT(start + bits <= bitmap->bits); |
|
aligned_start = ALIGN_UP(start, 8); |
lub = aligned_start - start; |
tub = (bits - lub) % 8; |
|
if (lub) { |
/* |
* Make sure to clear any leading unaligned bits. |
*/ |
bitmap->map[start / 8] &= (1 << (8 - lub)) - 1; |
} |
for (i = 0; i < (bits - lub) / 8; i++) { |
/* |
* The middle bits can be cleared byte by byte. |
*/ |
bitmap->map[aligned_start / 8 + i] = ALL_ZEROES; |
} |
if (tub) { |
/* |
* Make sure to clear any trailing unaligned bits. |
*/ |
bitmap->map[aligned_start / 8 + i] &= ~((1 << tub) - 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); |
} |
} |