arm/arm64: bitops: fix find_next_zero_bit to be compat with arm64

Current implementation of find_next_zero_bit() is incompatible with arm64.
Hence fix it by using BITS_PER_LONG define instead of constants and
use generic ffz() implementation.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>

diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h
index 2750d9b..b02c454 100644 (file)
--- a/arch/arm/include/asm/bitops.h
+++ b/arch/arm/include/asm/bitops.h
@@ -15,6 +15,8 @@
 #ifndef __ASM_ARM_BITOPS_H
 #define __ASM_ARM_BITOPS_H
 
+#include <asm-generic/bitops/__ffs.h>
+
 #ifdef __KERNEL__
 
 #include <asm/proc-armv/system.h>
@@ -108,50 +110,34 @@ static inline int __ilog2(unsigned int x)
        return generic_fls(x) - 1;
 }
 
-/*
- * ffz = Find First Zero in word. Undefined if no zero exists,
- * so code should check against ~0UL first..
- */
-static inline unsigned long ffz(unsigned long word)
-{
-       int k;
-
-       word = ~word;
-       k = 31;
-       if (word & 0x0000ffff) { k -= 16; word <<= 16; }
-       if (word & 0x00ff0000) { k -= 8;  word <<= 8;  }
-       if (word & 0x0f000000) { k -= 4;  word <<= 4;  }
-       if (word & 0x30000000) { k -= 2;  word <<= 2;  }
-       if (word & 0x40000000) { k -= 1; }
-       return k;
-}
+#define ffz(x)  __ffs(~(x))
 
 static inline int find_next_zero_bit(void *addr, int size, int offset)
 {
-       unsigned long *p = ((unsigned long *)addr) + (offset >> 5);
-       unsigned long result = offset & ~31UL;
+       unsigned long *p = ((unsigned long *)addr) + (offset / BITS_PER_LONG);
+       unsigned long result = offset & ~(BITS_PER_LONG - 1);
        unsigned long tmp;
 
        if (offset >= size)
                return size;
        size -= result;
-       offset &= 31UL;
+       offset &= (BITS_PER_LONG - 1);
        if (offset) {
                tmp = *(p++);
-               tmp |= ~0UL >> (32-offset);
-               if (size < 32)
+               tmp |= ~0UL >> (BITS_PER_LONG - offset);
+               if (size < BITS_PER_LONG)
                        goto found_first;
                if (~tmp)
                        goto found_middle;
-               size -= 32;
-               result += 32;
+               size -= BITS_PER_LONG;
+               result += BITS_PER_LONG;
        }
-       while (size & ~31UL) {
+       while (size & ~(BITS_PER_LONG - 1)) {
                tmp = *(p++);
                if (~tmp)
                        goto found_middle;
-               result += 32;
-               size -= 32;
+               result += BITS_PER_LONG;
+               size -= BITS_PER_LONG;
        }
        if (!size)
                return result;
@@ -191,7 +177,6 @@ found_middle:
 #endif /* __KERNEL__ */
 
 #include <asm-generic/bitops/__fls.h>
-#include <asm-generic/bitops/__ffs.h>
 #include <asm-generic/bitops/fls.h>
 #include <asm-generic/bitops/fls64.h>