[PATCH 11/18] lib: bitmap: Make the start index of bitmap_clear unsigned

From: Rasmus Villemoes
Date: Thu Jul 03 2014 - 18:45:57 EST


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@xxxxxxxxxxxxxxxxxx>
---
include/linux/bitmap.h | 2 +-
lib/bitmap.c | 10 +++++-----
2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index ad2c67d..83c1c7d 100644
--- 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
--- 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;
}
--
1.9.2

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