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Subject[PATCH 8/8] lib: bitmap: Minor changes of bitmap_remap
Date
Make the nbits parameter unsigned for consistency with most other
bitmap_* functions, and pull the test of empty dst out of the loop.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
include/linux/bitmap.h | 2 +-
lib/bitmap.c | 23 ++++++++++++++---------
2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index e854934cdbf9..690b180d723a 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -133,7 +133,7 @@ extern int bitmap_parselist(const char *buf, unsigned long *maskp,
extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
unsigned long *dst, int nbits);
extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
- const unsigned long *old, const unsigned long *new, int bits);
+ const unsigned long *old, const unsigned long *new, unsigned int nbits);
extern int bitmap_bitremap(int oldbit,
const unsigned long *old, const unsigned long *new, int bits);
extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 89b61e42f173..eda3bf0673ad 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -772,7 +772,7 @@ unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsig
* @src: subset to be remapped
* @old: defines domain of map
* @new: defines range of map
- * @bits: number of bits in each of these bitmaps
+ * @nbits: number of bits in each of these bitmaps
*
* Let @old and @new define a mapping of bit positions, such that
* whatever position is held by the n-th set bit in @old is mapped
@@ -800,22 +800,27 @@ unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsig
*/
void bitmap_remap(unsigned long *dst, const unsigned long *src,
const unsigned long *old, const unsigned long *new,
- int bits)
+ unsigned int nbits)
{
- int oldbit, w;
+ unsigned int oldbit, w;

if (dst == src) /* following doesn't handle inplace remaps */
return;
- bitmap_zero(dst, bits);

- w = bitmap_weight(new, bits);
- for_each_set_bit(oldbit, src, bits) {
- int n = bitmap_pos_to_ord(old, oldbit, bits);
+ w = bitmap_weight(new, nbits);
+ if (!w) {
+ bitmap_copy(dst, src, nbits);
+ return;
+ }
+
+ bitmap_zero(dst, nbits);
+ for_each_set_bit(oldbit, src, nbits) {
+ int n = bitmap_pos_to_ord(old, oldbit, nbits);

- if (n < 0 || w == 0)
+ if (n < 0)
set_bit(oldbit, dst); /* identity map */
else
- set_bit(bitmap_ord_to_pos(new, n % w, bits), dst);
+ set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
}
}
EXPORT_SYMBOL(bitmap_remap);
--
2.1.3


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