diff options
Diffstat (limited to 'lib/bitmap.c')
| -rw-r--r-- | lib/bitmap.c | 28 |
1 files changed, 11 insertions, 17 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c index 84d20b5c6bf1..e8a38bde7af9 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -771,34 +771,28 @@ static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigne * bitmap_ord_to_pos - find position of n-th set bit in bitmap * @buf: pointer to bitmap * @ord: ordinal bit position (n-th set bit, n >= 0) - * @bits: number of valid bit positions in @buf + * @nbits: number of valid bit positions in @buf * * Map the ordinal offset of bit @ord in @buf to its position in @buf. - * Value of @ord should be in range 0 <= @ord < weight(buf), else - * results are undefined. + * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord + * >= weight(buf), returns @nbits. * * If for example, just bits 4 through 7 are set in @buf, then @ord * values 0 through 3 will get mapped to 4 through 7, respectively, - * and all other @ord values return undefined values. When @ord value 3 + * and all other @ord values returns @nbits. When @ord value 3 * gets mapped to (returns) @pos value 7 in this example, that means * that the 3rd set bit (starting with 0th) is at position 7 in @buf. * - * The bit positions 0 through @bits are valid positions in @buf. + * The bit positions 0 through @nbits-1 are valid positions in @buf. */ -int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits) +unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) { - int pos = 0; + unsigned int pos; - if (ord >= 0 && ord < bits) { - int i; - - for (i = find_first_bit(buf, bits); - i < bits && ord > 0; - i = find_next_bit(buf, bits, i + 1)) - ord--; - if (i < bits && ord == 0) - pos = i; - } + for (pos = find_first_bit(buf, nbits); + pos < nbits && ord; + pos = find_next_bit(buf, nbits, pos + 1)) + ord--; return pos; } |