arch/x86_64/lib/bitstr.c

   1 #include <linux/module.h>
   2 #include <linux/bitops.h>
   3
   4 /* Find string of zero bits in a bitmap */
   5 unsigned long
   6 find_next_zero_string(unsigned long *bitmap, long start, long nbits, int len)
   7 {
   8         unsigned long n, end, i;
   9
  10  again:
  11         n = find_next_zero_bit(bitmap, nbits, start);
  12         if (n == -1)
  13                 return -1;
  14
  15         /* could test bitsliced, but it's hardly worth it */
  16         end = n+len;
  17         if (end >= nbits)
  18                 return -1;
  19         for (i = n+1; i < end; i++) {
  20                 if (test_bit(i, bitmap)) {
  21                         start = i+1;
  22                         goto again;
  23                 }
  24         }
  25         return n;
  26 }
  27
  28 EXPORT_SYMBOL(find_next_zero_string);