diff options
Diffstat (limited to 'kern/bitmap.c')
| -rw-r--r-- | kern/bitmap.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/kern/bitmap.c b/kern/bitmap.c index 849d3092..7343ba20 100644 --- a/kern/bitmap.c +++ b/kern/bitmap.c @@ -18,6 +18,15 @@ #include <kern/bitmap.h> #include <kern/limits.h> +static inline unsigned long +bitmap_find_next_compute_complement(unsigned long word, int nr_bits) +{ + if (nr_bits < LONG_BIT) + word |= (((unsigned long)-1) << nr_bits); + + return ~word; +} + int bitmap_find_next_bit(const unsigned long *bm, int nr_bits, int bit, int complement) @@ -28,13 +37,15 @@ bitmap_find_next_bit(const unsigned long *bm, int nr_bits, int bit, start = bm; end = bm + BITMAP_LONGS(nr_bits); - if (bit >= LONG_BIT) + if (bit >= LONG_BIT) { bitmap_lookup(bm, bit); + nr_bits -= ((bm - start) * LONG_BIT); + } word = *bm; if (complement) - word = ~word; + word = bitmap_find_next_compute_complement(word, nr_bits); if (bit < LONG_BIT) word &= ~(bitmap_mask(bit) - 1); @@ -50,9 +61,10 @@ bitmap_find_next_bit(const unsigned long *bm, int nr_bits, int bit, if (bm >= end) return -1; + nr_bits -= LONG_BIT; word = *bm; if (complement) - word = ~word; + word = bitmap_find_next_compute_complement(word, nr_bits); } } |