linux/tools/lib/bitmap.c
Wei Yang 692a68ee9c radix tree test suite: put definition of bitmap_clear() into lib/bitmap.c
In tools/ directory, function bitmap_clear() is currently only used in
object file tools/testing/radix-tree/xarray.o.

But instead of keeping a bitmap.c with only bitmap_clear() definition in
radix-tree's own directory, it would be more proper to put it in common
directory lib/.

Sync the kernel definition and link some related libs, no functional
change is expected.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Matthew Wilcox <willy@infradead.org>
CC: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
2024-07-10 14:24:27 -07:00

123 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* From lib/bitmap.c
* Helper functions for bitmap.h.
*/
#include <linux/bitmap.h>
unsigned int __bitmap_weight(const unsigned long *bitmap, int bits)
{
unsigned int k, w = 0, lim = bits/BITS_PER_LONG;
for (k = 0; k < lim; k++)
w += hweight_long(bitmap[k]);
if (bits % BITS_PER_LONG)
w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
return w;
}
void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
const unsigned long *bitmap2, int bits)
{
int k;
int nr = BITS_TO_LONGS(bits);
for (k = 0; k < nr; k++)
dst[k] = bitmap1[k] | bitmap2[k];
}
size_t bitmap_scnprintf(unsigned long *bitmap, unsigned int nbits,
char *buf, size_t size)
{
/* current bit is 'cur', most recently seen range is [rbot, rtop] */
unsigned int cur, rbot, rtop;
bool first = true;
size_t ret = 0;
rbot = cur = find_first_bit(bitmap, nbits);
while (cur < nbits) {
rtop = cur;
cur = find_next_bit(bitmap, nbits, cur + 1);
if (cur < nbits && cur <= rtop + 1)
continue;
if (!first)
ret += scnprintf(buf + ret, size - ret, ",");
first = false;
ret += scnprintf(buf + ret, size - ret, "%d", rbot);
if (rbot < rtop)
ret += scnprintf(buf + ret, size - ret, "-%d", rtop);
rbot = cur;
}
return ret;
}
bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int bits)
{
unsigned int k;
unsigned int lim = bits/BITS_PER_LONG;
unsigned long result = 0;
for (k = 0; k < lim; k++)
result |= (dst[k] = bitmap1[k] & bitmap2[k]);
if (bits % BITS_PER_LONG)
result |= (dst[k] = bitmap1[k] & bitmap2[k] &
BITMAP_LAST_WORD_MASK(bits));
return result != 0;
}
bool __bitmap_equal(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int bits)
{
unsigned int k, lim = bits/BITS_PER_LONG;
for (k = 0; k < lim; ++k)
if (bitmap1[k] != bitmap2[k])
return false;
if (bits % BITS_PER_LONG)
if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
return false;
return true;
}
bool __bitmap_intersects(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int bits)
{
unsigned int k, lim = bits/BITS_PER_LONG;
for (k = 0; k < lim; ++k)
if (bitmap1[k] & bitmap2[k])
return true;
if (bits % BITS_PER_LONG)
if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
return true;
return false;
}
void __bitmap_clear(unsigned long *map, unsigned int start, int len)
{
unsigned long *p = map + BIT_WORD(start);
const unsigned int size = start + len;
int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
while (len - bits_to_clear >= 0) {
*p &= ~mask_to_clear;
len -= bits_to_clear;
bits_to_clear = BITS_PER_LONG;
mask_to_clear = ~0UL;
p++;
}
if (len) {
mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
*p &= ~mask_to_clear;
}
}