Re: [U-Boot] [PATCH] arm: implement find_next_zero_bit function

Hello Vitaly,

On Thu, 5 Feb 2015 11:24:46 -0500, Vitaly Andrianov vitalya@ti.com wrote:

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

arch/arm/include/asm/bitops.h | 43 ++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 40 insertions(+), 3 deletions(-)

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 @@ static inline int __test_and_change_bit(int nr, volatile void *addr) 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 @@ static inline unsigned long ffz(unsigned long word) 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++);arm: implement find_next_zero_bit function
  

• 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 @@ static inline unsigned long ffz(unsigned long word) #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

1.9.1

Applied to u-boot-arm/master, thanks!

Amicalement,