arm: implement find_next_zero_bit function
This commit copies implementation of the find_next_zero_bit() from
git://git.denx.de/u-boot.git/arch/mips/include/asm/bitops.h. v2014.07
The function is required to enable MCAST_TFTP support for ARM platforms.
Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h
index 597dafb..9b78043 100644
--- a/arch/arm/include/asm/bitops.h
+++ b/arch/arm/include/asm/bitops.h
@@ -95,9 +95,6 @@
return (old & mask) != 0;
}
-extern int find_first_zero_bit(void * addr, unsigned size);
-extern int find_next_zero_bit(void * addr, int size, int offset);
-
/*
* This routine doesn't need to be atomic.
*/
@@ -129,6 +126,43 @@
return k;
}
+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 tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset &= 31UL;
+ if (offset) {
+ tmp = *(p++);
+ tmp |= ~0UL >> (32-offset);
+ if (size < 32)
+ goto found_first;
+ if (~tmp)
+ goto found_middle;
+ size -= 32;
+ result += 32;
+ }
+ while (size & ~31UL) {
+ tmp = *(p++);
+ if (~tmp)
+ goto found_middle;
+ result += 32;
+ size -= 32;
+ }
+ if (!size)
+ return result;
+ tmp = *p;
+
+found_first:
+ tmp |= ~0UL >> size;
+found_middle:
+ return result + ffz(tmp);
+}
+
/*
* hweightN: returns the hamming weight (i.e. the number
* of bits set) of a N-bit word
@@ -138,6 +172,9 @@
#define hweight16(x) generic_hweight16(x)
#define hweight8(x) generic_hweight8(x)
+#define find_first_zero_bit(addr, size) \
+ find_next_zero_bit((addr), (size), 0)
+
#define ext2_set_bit test_and_set_bit
#define ext2_clear_bit test_and_clear_bit
#define ext2_test_bit test_bit