-/*
- * Find next zero bit in a bitmap reasonably efficiently..
- */
-static inline unsigned long
-find_next_zero_bit(void * addr, unsigned long size, unsigned long offset)
-{
- unsigned long * p = ((unsigned long *) addr) + (offset >> 6);
- unsigned long result = offset & ~63UL;
- unsigned long tmp;
-
- if (offset >= size)
- return size;
- size -= result;
- offset &= 63UL;
- if (offset) {
- tmp = *(p++);
- tmp |= ~0UL >> (64-offset);
- if (size < 64)
- goto found_first;
- if (~tmp)
- goto found_middle;
- size -= 64;
- result += 64;
- }
- while (size & ~63UL) {
- if (~(tmp = *(p++)))
- goto found_middle;
- result += 64;
- size -= 64;
- }
- if (!size)
- return result;
- tmp = *p;
- found_first:
- tmp |= ~0UL << size;
- if (tmp == ~0UL) /* Are any bits zero? */
- return result + size; /* Nope. */
- found_middle:
- return result + ffz(tmp);
-}
-
-/*
- * Find next one bit in a bitmap reasonably efficiently.
- */
-static inline unsigned long
-find_next_bit(const void * addr, unsigned long size, unsigned long offset)
-{
- const unsigned long * p = ((const unsigned long *) addr) + (offset >> 6);
- unsigned long result = offset & ~63UL;
- unsigned long tmp;
-
- if (offset >= size)
- return size;
- size -= result;
- offset &= 63UL;
- if (offset) {
- tmp = *(p++);
- tmp &= ~0UL << offset;
- if (size < 64)
- goto found_first;
- if (tmp)
- goto found_middle;
- size -= 64;
- result += 64;
- }
- while (size & ~63UL) {
- if ((tmp = *(p++)))
- goto found_middle;
- result += 64;
- size -= 64;
- }
- if (!size)
- return result;
- tmp = *p;
- found_first:
- tmp &= ~0UL >> (64 - size);
- if (!tmp)
- return result + size;
- found_middle:
- return result + __ffs(tmp);
-}
-
-/*
- * The optimizer actually does good code for this case.
- */
-#define find_first_zero_bit(addr, size) \
- find_next_zero_bit((addr), (size), 0)
-#define find_first_bit(addr, size) \
- find_next_bit((addr), (size), 0)