// SPDX-License-Identifier: GPL-2.0+ #ifndef __LINUX_BITMAP_H #define __LINUX_BITMAP_H #include #include #include #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 */