s390/cio: use generic bitmap functions

Use generic bitmap functions in the subchannel id bitmap to
simplify and de-bloat the code.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/cio/idset.c

 /*
- *    Copyright IBM Corp. 2007
+ *    Copyright IBM Corp. 2007, 2012
  *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
  */
 
 #include <linux/vmalloc.h>
+#include <linux/bitmap.h>
 #include <linux/bitops.h>
 #include "idset.h"
 #include "css.h"
@@ -111,20 +112,13 @@ int idset_sch_get_first(struct idset *set, struct subchannel_id *schid)
 
 int idset_is_empty(struct idset *set)
 {
-	int bitnum;
-
-	bitnum = find_first_bit(set->bitmap, set->num_ssid * set->num_id);
-	if (bitnum >= set->num_ssid * set->num_id)
-		return 1;
-	return 0;
+	return bitmap_empty(set->bitmap, set->num_ssid * set->num_id);
 }
 
 void idset_add_set(struct idset *to, struct idset *from)
 {
-	unsigned long i, len;
-
-	len = min(__BITOPS_WORDS(to->num_ssid * to->num_id),
+	int len = min(__BITOPS_WORDS(to->num_ssid * to->num_id),
 		      __BITOPS_WORDS(from->num_ssid * from->num_id));
-	for (i = 0; i < len ; i++)
-		to->bitmap[i] |= from->bitmap[i];
+
+	bitmap_or(to->bitmap, to->bitmap, from->bitmap, len);
 }