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-rw-r--r--lib/find_bit.c59
1 files changed, 43 insertions, 16 deletions
diff --git a/lib/find_bit.c b/lib/find_bit.c
index 6ed74f7..ee3df93 100644
--- a/lib/find_bit.c
+++ b/lib/find_bit.c
@@ -21,22 +21,29 @@
#include <linux/export.h>
#include <linux/kernel.h>
-#if !defined(find_next_bit) || !defined(find_next_zero_bit)
+#if !defined(find_next_bit) || !defined(find_next_zero_bit) || \
+ !defined(find_next_and_bit)
/*
- * This is a common helper function for find_next_bit and
- * find_next_zero_bit. The difference is the "invert" argument, which
- * is XORed with each fetched word before searching it for one bits.
+ * This is a common helper function for find_next_bit, find_next_zero_bit, and
+ * find_next_and_bit. The differences are:
+ * - The "invert" argument, which is XORed with each fetched word before
+ * searching it for one bits.
+ * - The optional "addr2", which is anded with "addr1" if present.
*/
-static unsigned long _find_next_bit(const unsigned long *addr,
- unsigned long nbits, unsigned long start, unsigned long invert)
+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 tmp;
if (unlikely(start >= nbits))
return nbits;
- tmp = addr[start / BITS_PER_LONG] ^ invert;
+ tmp = addr1[start / BITS_PER_LONG];
+ if (addr2)
+ tmp &= addr2[start / BITS_PER_LONG];
+ tmp ^= invert;
/* Handle 1st word. */
tmp &= BITMAP_FIRST_WORD_MASK(start);
@@ -47,7 +54,10 @@ static unsigned long _find_next_bit(const unsigned long *addr,
if (start >= nbits)
return nbits;
- tmp = addr[start / BITS_PER_LONG] ^ invert;
+ tmp = addr1[start / BITS_PER_LONG];
+ if (addr2)
+ tmp &= addr2[start / BITS_PER_LONG];
+ tmp ^= invert;
}
return min(start + __ffs(tmp), nbits);
@@ -61,7 +71,7 @@ static unsigned long _find_next_bit(const unsigned long *addr,
unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
unsigned long offset)
{
- return _find_next_bit(addr, size, offset, 0UL);
+ return _find_next_bit(addr, NULL, size, offset, 0UL);
}
EXPORT_SYMBOL(find_next_bit);
#endif
@@ -70,11 +80,21 @@ 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, size, offset, ~0UL);
+ return _find_next_bit(addr, NULL, size, offset, ~0UL);
}
EXPORT_SYMBOL(find_next_zero_bit);
#endif
+#if !defined(find_next_and_bit)
+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);
+}
+EXPORT_SYMBOL(find_next_and_bit);
+#endif
+
#ifndef find_first_bit
/*
* Find the first set bit in a memory region.
@@ -146,15 +166,19 @@ static inline unsigned long ext2_swab(const unsigned long y)
}
#if !defined(find_next_bit_le) || !defined(find_next_zero_bit_le)
-static unsigned long _find_next_bit_le(const unsigned long *addr,
- unsigned long nbits, unsigned long start, unsigned long invert)
+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 = addr[start / BITS_PER_LONG] ^ invert;
+ tmp = addr1[start / BITS_PER_LONG];
+ if (addr2)
+ tmp &= addr2[start / BITS_PER_LONG];
+ tmp ^= invert;
/* Handle 1st word. */
tmp &= ext2_swab(BITMAP_FIRST_WORD_MASK(start));
@@ -165,7 +189,10 @@ static unsigned long _find_next_bit_le(const unsigned long *addr,
if (start >= nbits)
return nbits;
- tmp = addr[start / BITS_PER_LONG] ^ invert;
+ tmp = addr1[start / BITS_PER_LONG];
+ if (addr2)
+ tmp &= addr2[start / BITS_PER_LONG];
+ tmp ^= invert;
}
return min(start + __ffs(ext2_swab(tmp)), nbits);
@@ -176,7 +203,7 @@ static unsigned long _find_next_bit_le(const unsigned long *addr,
unsigned long find_next_zero_bit_le(const void *addr, unsigned
long size, unsigned long offset)
{
- return _find_next_bit_le(addr, size, offset, ~0UL);
+ return _find_next_bit_le(addr, NULL, size, offset, ~0UL);
}
EXPORT_SYMBOL(find_next_zero_bit_le);
#endif
@@ -185,7 +212,7 @@ 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, size, offset, 0UL);
+ return _find_next_bit_le(addr, NULL, size, offset, 0UL);
}
EXPORT_SYMBOL(find_next_bit_le);
#endif
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