linux/arch/x86_64/lib/bitstr.c

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#include <linux/module.h>
#include <linux/bitops.h>
/* Find string of zero bits in a bitmap */
unsigned long
find_next_zero_string(unsigned long *bitmap, long start, long nbits, int len)
{
unsigned long n, end, i;
again:
n = find_next_zero_bit(bitmap, nbits, start);
if (n == -1)
return -1;
/* could test bitsliced, but it's hardly worth it */
end = n+len;
if (end >= nbits)
return -1;
for (i = n+1; i < end; i++) {
if (test_bit(i, bitmap)) {
start = i+1;
goto again;
}
}
return n;
}
EXPORT_SYMBOL(find_next_zero_string);