46 lines
1.0 KiB
C
46 lines
1.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
|
|
/*
|
|
* A user-space bitmap wrapper to provide a subset of kernel bitmap operations.
|
|
*
|
|
* Most functions are not a direct copy of the kernel version, but should be
|
|
* good enough for single thread usage.
|
|
*/
|
|
|
|
#ifndef _BTRFS_PROGS_LINUX_BITMAP_H_
|
|
#define _BTRFS_PROGS_LINUX_BITMAP_H_
|
|
|
|
#include <stdlib.h>
|
|
#include "kerncompat.h"
|
|
#include "kernel-lib/bitops.h"
|
|
|
|
static inline unsigned long *bitmap_zalloc(unsigned int nbits)
|
|
{
|
|
return calloc(BITS_TO_LONGS(nbits), BITS_PER_LONG);
|
|
}
|
|
|
|
static inline void bitmap_free(unsigned long *bitmap)
|
|
{
|
|
free(bitmap);
|
|
}
|
|
|
|
#define BITMAP_LAST_WORK_MASK(nbits) (~0ULL >> (-(nbits) & (BITS_PER_LONG - 1)))
|
|
|
|
static inline unsigned int bitmap_weight(const unsigned long *bitmap, unsigned int nbits)
|
|
{
|
|
int ret = 0;
|
|
int i;
|
|
|
|
/* Handle the aligned part first. */
|
|
for (i = 0; i < nbits / BITS_PER_LONG; i++)
|
|
ret += hweight_long(bitmap[i]);
|
|
|
|
/* The remaining unaligned part. */
|
|
if (nbits % BITS_PER_LONG)
|
|
ret += bitmap[i] & BITMAP_LAST_WORD_MASK(nbits);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#endif
|