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// SPDX-License-Identifier: GPL-2.0+
#ifndef __LINUX_BITMAP_H
#define __LINUX_BITMAP_H
#include <asm/types.h>
#include <linux/types.h>
#include <linux/bitops.h>
#define small_const_nbits(nbits) \
(__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
static inline void bitmap_zero(unsigned long *dst, int nbits)
{
if (small_const_nbits(nbits)) {
*dst = 0UL;
} else {
int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
memset(dst, 0, len);
}
}
static inline unsigned long
find_next_bit(const unsigned long *addr, unsigned long size,
unsigned long offset)
{
const unsigned long *p = addr + BIT_WORD(offset);
unsigned long result = offset & ~(BITS_PER_LONG - 1);
unsigned long tmp;
if (offset >= size)
return size;
size -= result;
offset %= BITS_PER_LONG;
if (offset) {
tmp = *(p++);
tmp &= (~0UL << offset);
if (size < BITS_PER_LONG)
goto found_first;
if (tmp)
goto found_middle;
size -= BITS_PER_LONG;
result += BITS_PER_LONG;
}
while (size & ~(BITS_PER_LONG - 1)) {
tmp = *(p++);
if ((tmp))
goto found_middle;
result += BITS_PER_LONG;
size -= BITS_PER_LONG;
}
if (!size)
return result;
tmp = *p;
found_first:
tmp &= (~0UL >> (BITS_PER_LONG - size));
if (tmp == 0UL) /* Are any bits set? */
return result + size; /* Nope. */
found_middle:
return result + __ffs(tmp);
}
/*
* Find the first set bit in a memory region.
*/
static inline unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
{
unsigned long idx;
for (idx = 0; idx * BITS_PER_LONG < size; idx++) {
if (addr[idx])
return min(idx * BITS_PER_LONG + __ffs(addr[idx]), size);
}
return size;
}
#define for_each_set_bit(bit, addr, size) \
for ((bit) = find_first_bit((addr), (size)); \
(bit) < (size); \
(bit) = find_next_bit((addr), (size), (bit) + 1))
#endif /* __LINUX_BITMAP_H */
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