if (bits & 0x07)
return -EINVAL;
- memset(bitmap, 0, bits / 8);
-
if (str[0] == '0' && str[1] == 'x')
str++;
if (*str == 'x')
}
/*
- * str2clrsetmasks() - parse bitmask argument and set the clear and
- * the set bitmap mask. A concatenation (done with ',') of these terms
- * is recognized:
+ * modify_bitmap() - parse bitmask argument and modify an existing
+ * bit mask accordingly. A concatenation (done with ',') of these
+ * terms is recognized:
* +<bitnr>[-<bitnr>] or -<bitnr>[-<bitnr>]
* <bitnr> may be any valid number (hex, decimal or octal) in the range
* 0...bits-1; the leading + or - is required. Here are some examples:
* +0-15,+32,-128,-0xFF
* -0-255,+1-16,+0x128
* +1,+2,+3,+4,-5,-7-10
- * Returns a clear and a set bitmask. Every positive value in the string
- * results in a bit set in the set mask and every negative value in the
- * string results in a bit SET in the clear mask. As a bit may be touched
- * more than once, the last 'operation' wins: +0-255,-128 = all but bit
- * 128 set in the set mask, only bit 128 set in the clear mask.
+ * Returns the new bitmap after all changes have been applied. Every
+ * positive value in the string will set a bit and every negative value
+ * in the string will clear a bit. As a bit may be touched more than once,
+ * the last 'operation' wins:
+ * +0-255,-128 = first bits 0-255 will be set, then bit 128 will be
+ * cleared again. All other bits are unmodified.
*/
-static int str2clrsetmasks(const char *str,
- unsigned long *clrmap,
- unsigned long *setmap,
- int bits)
+static int modify_bitmap(const char *str, unsigned long *bitmap, int bits)
{
int a, i, z;
char *np, sign;
if (bits & 0x07)
return -EINVAL;
- memset(clrmap, 0, bits / 8);
- memset(setmap, 0, bits / 8);
-
while (*str) {
sign = *str++;
if (sign != '+' && sign != '-')
str = np;
}
for (i = a; i <= z; i++)
- if (sign == '+') {
- set_bit_inv(i, setmap);
- clear_bit_inv(i, clrmap);
- } else {
- clear_bit_inv(i, setmap);
- set_bit_inv(i, clrmap);
- }
+ if (sign == '+')
+ set_bit_inv(i, bitmap);
+ else
+ clear_bit_inv(i, bitmap);
while (*str == ',' || *str == '\n')
str++;
}
unsigned long *bitmap, int bits,
struct mutex *lock)
{
- int i;
+ unsigned long *newmap, size;
+ int rc;
/* bits needs to be a multiple of 8 */
if (bits & 0x07)
return -EINVAL;
+ size = BITS_TO_LONGS(bits)*sizeof(unsigned long);
+ newmap = kmalloc(size, GFP_KERNEL);
+ if (!newmap)
+ return -ENOMEM;
+ if (mutex_lock_interruptible(lock)) {
+ kfree(newmap);
+ return -ERESTARTSYS;
+ }
+
if (*str == '+' || *str == '-') {
- DECLARE_BITMAP(clrm, bits);
- DECLARE_BITMAP(setm, bits);
-
- i = str2clrsetmasks(str, clrm, setm, bits);
- if (i)
- return i;
- if (mutex_lock_interruptible(lock))
- return -ERESTARTSYS;
- for (i = 0; i < bits; i++) {
- if (test_bit_inv(i, clrm))
- clear_bit_inv(i, bitmap);
- if (test_bit_inv(i, setm))
- set_bit_inv(i, bitmap);
- }
+ memcpy(newmap, bitmap, size);
+ rc = modify_bitmap(str, newmap, bits);
} else {
- DECLARE_BITMAP(setm, bits);
-
- i = hex2bitmap(str, setm, bits);
- if (i)
- return i;
- if (mutex_lock_interruptible(lock))
- return -ERESTARTSYS;
- for (i = 0; i < bits; i++)
- if (test_bit_inv(i, setm))
- set_bit_inv(i, bitmap);
- else
- clear_bit_inv(i, bitmap);
+ memset(newmap, 0, size);
+ rc = hex2bitmap(str, newmap, bits);
}
+ if (rc == 0)
+ memcpy(bitmap, newmap, size);
mutex_unlock(lock);
-
- return 0;
+ kfree(newmap);
+ return rc;
}
/*