lib: bitmap: make the start index of bitmap_clear 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 for
consistency with bitmap_set.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index ad2c67d..83c1c7d 100644 (file)
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -113,7 +113,7 @@ extern int __bitmap_subset(const unsigned long *bitmap1,
 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
 
 extern void bitmap_set(unsigned long *map, unsigned int start, int len);
-extern void bitmap_clear(unsigned long *map, int start, int nr);
+extern void bitmap_clear(unsigned long *map, unsigned int start, int len);
 extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
                                         unsigned long size,
                                         unsigned long start,

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 2a3a92f..5d25403 100644 (file)
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -295,21 +295,21 @@ void bitmap_set(unsigned long *map, unsigned int start, int len)
 }
 EXPORT_SYMBOL(bitmap_set);
 
-void bitmap_clear(unsigned long *map, int start, int nr)
+void bitmap_clear(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_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
        unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
 
-       while (nr - bits_to_clear >= 0) {
+       while (len - bits_to_clear >= 0) {
                *p &= ~mask_to_clear;
-               nr -= bits_to_clear;
+               len -= bits_to_clear;
                bits_to_clear = BITS_PER_LONG;
                mask_to_clear = ~0UL;
                p++;
        }
-       if (nr) {
+       if (len) {
                mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
                *p &= ~mask_to_clear;
        }