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

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

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,
-- 
Albert.