lib: add fast path for find_next_*_bit()

[linux-2.6-microblaze.git] / include / asm-generic / bitops / le.h

diff --git a/include/asm-generic/bitops/le.h b/include/asm-generic/bitops/le.h
index 21305f6..5a28629 100644 (file)
--- a/include/asm-generic/bitops/le.h
+++ b/include/asm-generic/bitops/le.h
@@ -5,6 +5,7 @@
 #include <asm-generic/bitops/find.h>
 #include <asm/types.h>
 #include <asm/byteorder.h>
+#include <linux/swab.h>
 
 #if defined(__LITTLE_ENDIAN)
 
@@ -37,6 +38,16 @@ static inline
 unsigned long find_next_zero_bit_le(const void *addr, unsigned
                long size, unsigned long offset)
 {
+       if (small_const_nbits(size)) {
+               unsigned long val = *(const unsigned long *)addr;
+
+               if (unlikely(offset >= size))
+                       return size;
+
+               val = swab(val) | ~GENMASK(size - 1, offset);
+               return val == ~0UL ? size : ffz(val);
+       }
+
        return _find_next_bit(addr, NULL, size, offset, ~0UL, 1);
 }
 #endif
@@ -46,6 +57,16 @@ static inline
 unsigned long find_next_bit_le(const void *addr, unsigned
                long size, unsigned long offset)
 {
+       if (small_const_nbits(size)) {
+               unsigned long val = *(const unsigned long *)addr;
+
+               if (unlikely(offset >= size))
+                       return size;
+
+               val = swab(val) & GENMASK(size - 1, offset);
+               return val ? __ffs(val) : size;
+       }
+
        return _find_next_bit(addr, NULL, size, offset, 0UL, 1);
 }
 #endif