linux/fs/xfs/libxfs/xfs_bit.c
Eric Sandeen 250d4b4c40 xfs: remove unused header files
There are many, many xfs header files which are included but
unneeded (or included twice) in the xfs code, so remove them.

nb: xfs_linux.h includes about 9 headers for everyone, so those
explicit includes get removed by this.  I'm not sure what the
preference is, but if we wanted explicit includes everywhere,
a followup patch could remove those xfs_*.h includes from
xfs_linux.h and move them into the files that need them.
Or it could be left as-is.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-28 19:30:43 -07:00

106 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_log_format.h"
/*
* XFS bit manipulation routines, used in non-realtime code.
*/
/*
* Return whether bitmap is empty.
* Size is number of words in the bitmap, which is padded to word boundary
* Returns 1 for empty, 0 for non-empty.
*/
int
xfs_bitmap_empty(uint *map, uint size)
{
uint i;
for (i = 0; i < size; i++) {
if (map[i] != 0)
return 0;
}
return 1;
}
/*
* Count the number of contiguous bits set in the bitmap starting with bit
* start_bit. Size is the size of the bitmap in words.
*/
int
xfs_contig_bits(uint *map, uint size, uint start_bit)
{
uint * p = ((unsigned int *) map) + (start_bit >> BIT_TO_WORD_SHIFT);
uint result = 0;
uint tmp;
size <<= BIT_TO_WORD_SHIFT;
ASSERT(start_bit < size);
size -= start_bit & ~(NBWORD - 1);
start_bit &= (NBWORD - 1);
if (start_bit) {
tmp = *p++;
/* set to one first offset bits prior to start */
tmp |= (~0U >> (NBWORD-start_bit));
if (tmp != ~0U)
goto found;
result += NBWORD;
size -= NBWORD;
}
while (size) {
if ((tmp = *p++) != ~0U)
goto found;
result += NBWORD;
size -= NBWORD;
}
return result - start_bit;
found:
return result + ffz(tmp) - start_bit;
}
/*
* This takes the bit number to start looking from and
* returns the next set bit from there. It returns -1
* if there are no more bits set or the start bit is
* beyond the end of the bitmap.
*
* Size is the number of words, not bytes, in the bitmap.
*/
int xfs_next_bit(uint *map, uint size, uint start_bit)
{
uint * p = ((unsigned int *) map) + (start_bit >> BIT_TO_WORD_SHIFT);
uint result = start_bit & ~(NBWORD - 1);
uint tmp;
size <<= BIT_TO_WORD_SHIFT;
if (start_bit >= size)
return -1;
size -= result;
start_bit &= (NBWORD - 1);
if (start_bit) {
tmp = *p++;
/* set to zero first offset bits prior to start */
tmp &= (~0U << start_bit);
if (tmp != 0U)
goto found;
result += NBWORD;
size -= NBWORD;
}
while (size) {
if ((tmp = *p++) != 0U)
goto found;
result += NBWORD;
size -= NBWORD;
}
return -1;
found:
return result + ffs(tmp) - 1;
}