* ranges. Consecutively set bits are shown as two hyphen-separated
* decimal numbers, the smallest and largest bit numbers set in
* the range.
+ * Optionally each range can be postfixed to denote that only parts of it
+ * should be set. The range will divided to groups of specific size.
+ * From each group will be used only defined amount of bits.
+ * Syntax: range:used_size/group_size
+ * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769
*
* Returns 0 on success, -errno on invalid input strings.
* Error values:
int is_user, unsigned long *maskp,
int nmaskbits)
{
- unsigned a, b;
+ unsigned int a, b, old_a, old_b;
+ unsigned int group_size, used_size;
int c, old_c, totaldigits, ndigits;
const char __user __force *ubuf = (const char __user __force *)buf;
- int at_start, in_range;
+ int at_start, in_range, in_partial_range;
totaldigits = c = 0;
+ old_a = old_b = 0;
+ group_size = used_size = 0;
bitmap_zero(maskp, nmaskbits);
do {
at_start = 1;
in_range = 0;
+ in_partial_range = 0;
a = b = 0;
ndigits = totaldigits;
if ((totaldigits != ndigits) && isspace(old_c))
return -EINVAL;
+ if (c == '/') {
+ used_size = a;
+ at_start = 1;
+ in_range = 0;
+ a = b = 0;
+ continue;
+ }
+
+ if (c == ':') {
+ old_a = a;
+ old_b = b;
+ at_start = 1;
+ in_range = 0;
+ in_partial_range = 1;
+ a = b = 0;
+ continue;
+ }
+
if (c == '-') {
if (at_start || in_range)
return -EINVAL;
}
if (ndigits == totaldigits)
continue;
+ if (in_partial_range) {
+ group_size = a;
+ a = old_a;
+ b = old_b;
+ old_a = old_b = 0;
+ }
/* if no digit is after '-', it's wrong*/
if (at_start && in_range)
return -EINVAL;
- if (!(a <= b))
+ if (!(a <= b) || !(used_size <= group_size))
return -EINVAL;
if (b >= nmaskbits)
return -ERANGE;
while (a <= b) {
- set_bit(a, maskp);
+ if (in_partial_range) {
+ static int pos_in_group = 1;
+
+ if (pos_in_group <= used_size)
+ set_bit(a, maskp);
+
+ if (a == b || ++pos_in_group > group_size)
+ pos_in_group = 1;
+ } else
+ set_bit(a, maskp);
a++;
}
} while (buflen && c == ',');