#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
-/**
- * find_next_bit - find the next set bit in a memory region
- * @addr: The address to base the search on
- * @offset: The bitnumber to start searching at
- * @size: The maximum size to search
+#ifdef CONFIG_GENERIC_FIND_NEXT_BIT
+/*
+ * Find the next set bit in a memory region.
*/
unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
- unsigned long offset)
+ unsigned long offset)
{
const unsigned long *p = addr + BITOP_WORD(offset);
unsigned long result = offset & ~(BITS_PER_LONG-1);
found_middle:
return result + __ffs(tmp);
}
-
EXPORT_SYMBOL(find_next_bit);
/*
* Linus' asm-alpha/bitops.h.
*/
unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
- unsigned long offset)
+ unsigned long offset)
{
const unsigned long *p = addr + BITOP_WORD(offset);
unsigned long result = offset & ~(BITS_PER_LONG-1);
found_middle:
return result + ffz(tmp);
}
-
EXPORT_SYMBOL(find_next_zero_bit);
+#endif /* CONFIG_GENERIC_FIND_NEXT_BIT */
+
+#ifdef CONFIG_GENERIC_FIND_FIRST_BIT
+/*
+ * Find the first set bit in a memory region.
+ */
+unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
+{
+ const unsigned long *p = addr;
+ unsigned long result = 0;
+ unsigned long tmp;
+
+ while (size & ~(BITS_PER_LONG-1)) {
+ if ((tmp = *(p++)))
+ goto found;
+ result += BITS_PER_LONG;
+ size -= BITS_PER_LONG;
+ }
+ if (!size)
+ return result;
+
+ tmp = (*p) & (~0UL >> (BITS_PER_LONG - size));
+ if (tmp == 0UL) /* Are any bits set? */
+ return result + size; /* Nope. */
+found:
+ return result + __ffs(tmp);
+}
+EXPORT_SYMBOL(find_first_bit);
+
+/*
+ * Find the first cleared bit in a memory region.
+ */
+unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
+{
+ const unsigned long *p = addr;
+ unsigned long result = 0;
+ unsigned long tmp;
+
+ while (size & ~(BITS_PER_LONG-1)) {
+ if (~(tmp = *(p++)))
+ goto found;
+ result += BITS_PER_LONG;
+ size -= BITS_PER_LONG;
+ }
+ if (!size)
+ return result;
+
+ tmp = (*p) | (~0UL << size);
+ if (tmp == ~0UL) /* Are any bits zero? */
+ return result + size; /* Nope. */
+found:
+ return result + ffz(tmp);
+}
+EXPORT_SYMBOL(find_first_zero_bit);
+#endif /* CONFIG_GENERIC_FIND_FIRST_BIT */
#ifdef __BIG_ENDIAN
EXPORT_SYMBOL(generic_find_next_zero_le_bit);
+unsigned long generic_find_next_le_bit(const unsigned long *addr, unsigned
+ long size, unsigned long offset)
+{
+ const unsigned long *p = addr + BITOP_WORD(offset);
+ unsigned long result = offset & ~(BITS_PER_LONG - 1);
+ unsigned long tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset &= (BITS_PER_LONG - 1UL);
+ if (offset) {
+ tmp = ext2_swabp(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_swap;
+ result += BITS_PER_LONG;
+ size -= BITS_PER_LONG;
+ }
+ if (!size)
+ return result;
+ tmp = ext2_swabp(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);
+
+found_middle_swap:
+ return result + __ffs(ext2_swab(tmp));
+}
+EXPORT_SYMBOL(generic_find_next_le_bit);
#endif /* __BIG_ENDIAN */