1 files changed, 43 insertions, 16 deletions

diff --git a/lib/find_bit.c b/lib/find_bit.c
index 6ed74f78380c..ee3df93ba69a 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