slub: Deal with config variable dependencies
[linux-2.6.git] / lib / find_next_bit.c
index 9c90853..78ccd73 100644 (file)
@@ -12,6 +12,7 @@
 #include <linux/bitops.h>
 #include <linux/module.h>
 #include <asm/types.h>
+#include <asm/byteorder.h>
 
 #define BITOP_WORD(nr)         ((nr) / BITS_PER_LONG)
 
@@ -106,3 +107,118 @@ found_middle:
 }
 
 EXPORT_SYMBOL(find_next_zero_bit);
+
+#ifdef __BIG_ENDIAN
+
+/* include/linux/byteorder does not support "unsigned long" type */
+static inline unsigned long ext2_swabp(const unsigned long * x)
+{
+#if BITS_PER_LONG == 64
+       return (unsigned long) __swab64p((u64 *) x);
+#elif BITS_PER_LONG == 32
+       return (unsigned long) __swab32p((u32 *) x);
+#else
+#error BITS_PER_LONG not defined
+#endif
+}
+
+/* include/linux/byteorder doesn't support "unsigned long" type */
+static inline unsigned long ext2_swab(const unsigned long y)
+{
+#if BITS_PER_LONG == 64
+       return (unsigned long) __swab64((u64) y);
+#elif BITS_PER_LONG == 32
+       return (unsigned long) __swab32((u32) y);
+#else
+#error BITS_PER_LONG not defined
+#endif
+}
+
+unsigned long generic_find_next_zero_le_bit(const unsigned long *addr, unsigned
+               long size, unsigned long offset)
+{
+       const unsigned long *p = addr + BITOP_WORD(offset);
+       unsigned long result = offset & ~(BITS_PER_LONG - 1);
+       unsigned long tmp;
+
+       if (offset >= size)
+               return size;
+       size -= result;
+       offset &= (BITS_PER_LONG - 1UL);
+       if (offset) {
+               tmp = ext2_swabp(p++);
+               tmp |= (~0UL >> (BITS_PER_LONG - offset));
+               if (size < BITS_PER_LONG)
+                       goto found_first;
+               if (~tmp)
+                       goto found_middle;
+               size -= BITS_PER_LONG;
+               result += BITS_PER_LONG;
+       }
+
+       while (size & ~(BITS_PER_LONG - 1)) {
+               if (~(tmp = *(p++)))
+                       goto found_middle_swap;
+               result += BITS_PER_LONG;
+               size -= BITS_PER_LONG;
+       }
+       if (!size)
+               return result;
+       tmp = ext2_swabp(p);
+found_first:
+       tmp |= ~0UL << size;
+       if (tmp == ~0UL)        /* Are any bits zero? */
+               return result + size; /* Nope. Skip ffz */
+found_middle:
+       return result + ffz(tmp);
+
+found_middle_swap:
+       return result + ffz(ext2_swab(tmp));
+}
+
+EXPORT_SYMBOL(generic_find_next_zero_le_bit);
+
+unsigned long generic_find_next_le_bit(const unsigned long *addr, unsigned
+               long size, unsigned long offset)
+{
+       const unsigned long *p = addr + BITOP_WORD(offset);
+       unsigned long result = offset & ~(BITS_PER_LONG - 1);
+       unsigned long tmp;
+
+       if (offset >= size)
+               return size;
+       size -= result;
+       offset &= (BITS_PER_LONG - 1UL);
+       if (offset) {
+               tmp = ext2_swabp(p++);
+               tmp &= (~0UL << offset);
+               if (size < BITS_PER_LONG)
+                       goto found_first;
+               if (tmp)
+                       goto found_middle;
+               size -= BITS_PER_LONG;
+               result += BITS_PER_LONG;
+       }
+
+       while (size & ~(BITS_PER_LONG - 1)) {
+               tmp = *(p++);
+               if (tmp)
+                       goto found_middle_swap;
+               result += BITS_PER_LONG;
+               size -= BITS_PER_LONG;
+       }
+       if (!size)
+               return result;
+       tmp = ext2_swabp(p);
+found_first:
+       tmp &= (~0UL >> (BITS_PER_LONG - size));
+       if (tmp == 0UL)         /* Are any bits set? */
+               return result + size; /* Nope. */
+found_middle:
+       return result + __ffs(tmp);
+
+found_middle_swap:
+       return result + __ffs(ext2_swab(tmp));
+}
+EXPORT_SYMBOL(generic_find_next_le_bit);
+#endif /* __BIG_ENDIAN */