lib: bitmap: make the start index of bitmap_set unsigned

The compiler can generate slightly smaller and simpler code when it
knows that "start" is non-negative.

Also, use the names "start" and "len" for the two parameters in both
header file and implementation, instead of the previous mix.

Signed-off-by: Rasmus Villemoes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 64b0ebe..ad2c67d 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -112,7 +112,7 @@
 			const unsigned long *bitmap2, unsigned int nbits);
 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
 
-extern void bitmap_set(unsigned long *map, int i, int len);
+extern void bitmap_set(unsigned long *map, unsigned int start, int len);
 extern void bitmap_clear(unsigned long *map, int start, int nr);
 extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
 					 unsigned long size,
diff --git a/lib/bitmap.c b/lib/bitmap.c
index f69435c..2a3a92f 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -274,21 +274,21 @@
 }
 EXPORT_SYMBOL(__bitmap_weight);
 
-void bitmap_set(unsigned long *map, int start, int nr)
+void bitmap_set(unsigned long *map, unsigned int start, int len)
 {
 	unsigned long *p = map + BIT_WORD(start);
-	const int size = start + nr;
+	const unsigned int size = start + len;
 	int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
 	unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
 
-	while (nr - bits_to_set >= 0) {
+	while (len - bits_to_set >= 0) {
 		*p |= mask_to_set;
-		nr -= bits_to_set;
+		len -= bits_to_set;
 		bits_to_set = BITS_PER_LONG;
 		mask_to_set = ~0UL;
 		p++;
 	}
-	if (nr) {
+	if (len) {
 		mask_to_set &= BITMAP_LAST_WORD_MASK(size);
 		*p |= mask_to_set;
 	}