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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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