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-rw-r--r--lib/bitmap.c68
1 files changed, 25 insertions, 43 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 488e6c3e5acc..1c81413c51f8 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -333,20 +333,32 @@ bool __bitmap_subset(const unsigned long *bitmap1,
}
EXPORT_SYMBOL(__bitmap_subset);
+#define BITMAP_WEIGHT(FETCH, bits) \
+({ \
+ unsigned int __bits = (bits), idx, w = 0; \
+ \
+ for (idx = 0; idx < __bits / BITS_PER_LONG; idx++) \
+ w += hweight_long(FETCH); \
+ \
+ if (__bits % BITS_PER_LONG) \
+ w += hweight_long((FETCH) & BITMAP_LAST_WORD_MASK(__bits)); \
+ \
+ w; \
+})
+
unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
{
- unsigned int k, lim = bits/BITS_PER_LONG, w = 0;
-
- for (k = 0; k < lim; k++)
- w += hweight_long(bitmap[k]);
-
- if (bits % BITS_PER_LONG)
- w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
-
- return w;
+ return BITMAP_WEIGHT(bitmap[idx], bits);
}
EXPORT_SYMBOL(__bitmap_weight);
+unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
+ const unsigned long *bitmap2, unsigned int bits)
+{
+ return BITMAP_WEIGHT(bitmap1[idx] & bitmap2[idx], bits);
+}
+EXPORT_SYMBOL(__bitmap_weight_and);
+
void __bitmap_set(unsigned long *map, unsigned int start, int len)
{
unsigned long *p = map + BIT_WORD(start);
@@ -953,37 +965,7 @@ static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigne
if (pos >= nbits || !test_bit(pos, buf))
return -1;
- return __bitmap_weight(buf, pos);
-}
-
-/**
- * bitmap_ord_to_pos - find position of n-th set bit in bitmap
- * @buf: pointer to bitmap
- * @ord: ordinal bit position (n-th set bit, n >= 0)
- * @nbits: number of valid bit positions in @buf
- *
- * Map the ordinal offset of bit @ord in @buf to its position in @buf.
- * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
- * >= weight(buf), returns @nbits.
- *
- * If for example, just bits 4 through 7 are set in @buf, then @ord
- * values 0 through 3 will get mapped to 4 through 7, respectively,
- * and all other @ord values returns @nbits. When @ord value 3
- * gets mapped to (returns) @pos value 7 in this example, that means
- * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
- *
- * The bit positions 0 through @nbits-1 are valid positions in @buf.
- */
-unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
-{
- unsigned int pos;
-
- for (pos = find_first_bit(buf, nbits);
- pos < nbits && ord;
- pos = find_next_bit(buf, nbits, pos + 1))
- ord--;
-
- return pos;
+ return bitmap_weight(buf, pos);
}
/**
@@ -1035,7 +1017,7 @@ void bitmap_remap(unsigned long *dst, const unsigned long *src,
if (n < 0 || w == 0)
set_bit(oldbit, dst); /* identity map */
else
- set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
+ set_bit(find_nth_bit(new, nbits, n % w), dst);
}
}
EXPORT_SYMBOL(bitmap_remap);
@@ -1074,7 +1056,7 @@ int bitmap_bitremap(int oldbit, const unsigned long *old,
if (n < 0 || w == 0)
return oldbit;
else
- return bitmap_ord_to_pos(new, n % w, bits);
+ return find_nth_bit(new, bits, n % w);
}
EXPORT_SYMBOL(bitmap_bitremap);
@@ -1198,7 +1180,7 @@ void bitmap_onto(unsigned long *dst, const unsigned long *orig,
* The following code is a more efficient, but less
* obvious, equivalent to the loop:
* for (m = 0; m < bitmap_weight(relmap, bits); m++) {
- * n = bitmap_ord_to_pos(orig, m, bits);
+ * n = find_nth_bit(orig, bits, m);
* if (test_bit(m, orig))
* set_bit(n, dst);
* }