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Subject[PATCH 2/3] lib/find_bit.c: join _find_next_bit{_le}
Date
_find_next_bit and _find_next_bit_le are very similar functions.
It's possible to join them by adding 1 parameter and a couple of
simple checks. It's simplify maintenance and make possible to
shrink the size of .text by un-inlining the unified function (in
the following patch).

Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
lib/find_bit.c | 64 +++++++++++++++-----------------------------------
1 file changed, 19 insertions(+), 45 deletions(-)

diff --git a/lib/find_bit.c b/lib/find_bit.c
index 06e503c339f37..c03cbecb2b1f6 100644
--- a/lib/find_bit.c
+++ b/lib/find_bit.c
@@ -17,9 +17,9 @@
#include <linux/export.h>
#include <linux/kernel.h>

-#if !defined(find_next_bit) || !defined(find_next_zero_bit) || \
- !defined(find_next_and_bit)
-
+#if !defined(find_next_bit) || !defined(find_next_zero_bit) || \
+ !defined(find_next_bit_le) || !defined(find_next_zero_bit_le) || \
+ !defined(find_next_and_bit)
/*
* This is a common helper function for find_next_bit, find_next_zero_bit, and
* find_next_and_bit. The differences are:
@@ -29,9 +29,9 @@
*/
static inline unsigned long _find_next_bit(const unsigned long *addr1,
const unsigned long *addr2, unsigned long nbits,
- unsigned long start, unsigned long invert)
+ unsigned long start, unsigned long invert, unsigned long le)
{
- unsigned long tmp;
+ unsigned long tmp, mask;

if (unlikely(start >= nbits))
return nbits;
@@ -42,7 +42,12 @@ static inline unsigned long _find_next_bit(const unsigned long *addr1,
tmp ^= invert;

/* Handle 1st word. */
- tmp &= BITMAP_FIRST_WORD_MASK(start);
+ mask = BITMAP_FIRST_WORD_MASK(start);
+ if (le)
+ mask = swab(mask);
+
+ tmp &= mask;
+
start = round_down(start, BITS_PER_LONG);

while (!tmp) {
@@ -56,6 +61,9 @@ static inline unsigned long _find_next_bit(const unsigned long *addr1,
tmp ^= invert;
}

+ if (le)
+ tmp = swab(tmp);
+
return min(start + __ffs(tmp), nbits);
}
#endif
@@ -67,7 +75,7 @@ static inline unsigned long _find_next_bit(const unsigned long *addr1,
unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
unsigned long offset)
{
- return _find_next_bit(addr, NULL, size, offset, 0UL);
+ return _find_next_bit(addr, NULL, size, offset, 0UL, 0);
}
EXPORT_SYMBOL(find_next_bit);
#endif
@@ -76,7 +84,7 @@ EXPORT_SYMBOL(find_next_bit);
unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
unsigned long offset)
{
- return _find_next_bit(addr, NULL, size, offset, ~0UL);
+ return _find_next_bit(addr, NULL, size, offset, ~0UL, 0);
}
EXPORT_SYMBOL(find_next_zero_bit);
#endif
@@ -86,7 +94,7 @@ unsigned long find_next_and_bit(const unsigned long *addr1,
const unsigned long *addr2, unsigned long size,
unsigned long offset)
{
- return _find_next_bit(addr1, addr2, size, offset, 0UL);
+ return _find_next_bit(addr1, addr2, size, offset, 0UL, 0);
}
EXPORT_SYMBOL(find_next_and_bit);
#endif
@@ -149,45 +157,11 @@ EXPORT_SYMBOL(find_last_bit);

#ifdef __BIG_ENDIAN

-#if !defined(find_next_bit_le) || !defined(find_next_zero_bit_le)
-static inline unsigned long _find_next_bit_le(const unsigned long *addr1,
- const unsigned long *addr2, unsigned long nbits,
- unsigned long start, unsigned long invert)
-{
- unsigned long tmp;
-
- if (unlikely(start >= nbits))
- return nbits;
-
- tmp = addr1[start / BITS_PER_LONG];
- if (addr2)
- tmp &= addr2[start / BITS_PER_LONG];
- tmp ^= invert;
-
- /* Handle 1st word. */
- tmp &= swab(BITMAP_FIRST_WORD_MASK(start));
- start = round_down(start, BITS_PER_LONG);
-
- while (!tmp) {
- start += BITS_PER_LONG;
- if (start >= nbits)
- return nbits;
-
- tmp = addr1[start / BITS_PER_LONG];
- if (addr2)
- tmp &= addr2[start / BITS_PER_LONG];
- tmp ^= invert;
- }
-
- return min(start + __ffs(swab(tmp)), nbits);
-}
-#endif
-
#ifndef find_next_zero_bit_le
unsigned long find_next_zero_bit_le(const void *addr, unsigned
long size, unsigned long offset)
{
- return _find_next_bit_le(addr, NULL, size, offset, ~0UL);
+ return _find_next_bit(addr, NULL, size, offset, ~0UL, 1);
}
EXPORT_SYMBOL(find_next_zero_bit_le);
#endif
@@ -196,7 +170,7 @@ EXPORT_SYMBOL(find_next_zero_bit_le);
unsigned long find_next_bit_le(const void *addr, unsigned
long size, unsigned long offset)
{
- return _find_next_bit_le(addr, NULL, size, offset, 0UL);
+ return _find_next_bit(addr, NULL, size, offset, 0UL, 1);
}
EXPORT_SYMBOL(find_next_bit_le);
#endif
--
2.20.1
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