Re: [PATCH v3 1/7] m68knommu: fix build error due to the lack of find_next_bit_le()

[Greg Ungerer <gerg@snapgear.com>]

Hi Akinobu,

On 27/04/11 23:20, Akinobu Mita wrote:
> m68knommu can't build ext4, udf, and ocfs2 due to the lack of
> find_next_bit_le().
>
> This implements find_next_bit_le() on m68knommu by duplicating the
> generic find_next_bit_le() in lib/find_next_bit.c.

Wouldn't the m68k specific implementation of this in
arch/m68k/include/asm/bitops_mm.h be better?

(bitops_*.h is still on my list of files to clean up and
merge for m68k mmu and non-mmu)

Regards
Greg



> Signed-off-by: Akinobu Mita<akinobu.mita@gmail.com>
> Cc: Greg Ungerer<gerg@uclinux.org>
> ---
>
> This patch should go into 2.6.39
>
>   arch/m68k/include/asm/bitops_no.h |   44 +++++++++++++++++++++++++++++++++++++
>   1 files changed, 44 insertions(+), 0 deletions(-)
>
> diff --git a/arch/m68k/include/asm/bitops_no.h b/arch/m68k/include/asm/bitops_no.h
> index 7d3779f..97d1d0c 100644
> --- a/arch/m68k/include/asm/bitops_no.h
> +++ b/arch/m68k/include/asm/bitops_no.h
> @@ -336,6 +336,50 @@ found_middle:
>   	return result + ffz(__swab32(tmp));
>   }
>
> +static inline unsigned long find_next_bit_le(const void *addr, unsigned
> +		long size, unsigned long offset)
> +{
> +	const unsigned long *p = addr;
> +	unsigned long result = offset&  ~(BITS_PER_LONG - 1);
> +	unsigned long tmp;
> +
> +	if (offset>= size)
> +		return size;
> +	p += offset / BITS_PER_LONG;
> +	size -= result;
> +	offset&= (BITS_PER_LONG - 1UL);
> +	if (offset) {
> +		tmp = __swab32(*(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 = __swab32(*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(__swab32(tmp));
> +}
> +
>   #endif /* __KERNEL__ */
>
>   #include<asm-generic/bitops/fls.h>


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Greg Ungerer  --  Principal Engineer        EMAIL:     gerg@snapgear.com
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