Re: [Qemu-devel] [QEMU v2 7/9] bitmap: Add a new bitmap_move function

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Liang Li (liang.z.li@intel.com) wrote:
> Sometimes, it is need to move a portion of bitmap to another place
> in a large bitmap, if overlap happens, the bitmap_copy can't not
> work correctly, we need a new function to do this work.
> 
> Signed-off-by: Liang Li <liang.z.li@intel.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  include/qemu/bitmap.h | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h
> index ec5146f..6ac89ca 100644
> --- a/include/qemu/bitmap.h
> +++ b/include/qemu/bitmap.h
> @@ -37,6 +37,7 @@
>   * bitmap_set(dst, pos, nbits)			Set specified bit area
>   * bitmap_set_atomic(dst, pos, nbits)   Set specified bit area with atomic ops
>   * bitmap_clear(dst, pos, nbits)		Clear specified bit area
> + * bitmap_move(dst, src, nbits)                 Move *src to *dst
>   * bitmap_test_and_clear_atomic(dst, pos, nbits)    Test and clear area
>   * bitmap_find_next_zero_area(buf, len, pos, n, mask)	Find bit free area
>   */
> @@ -136,6 +137,18 @@ static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
>      }
>  }
>  
> +static inline void bitmap_move(unsigned long *dst, const unsigned long *src,
> +                               long nbits)
> +{
> +    if (small_nbits(nbits)) {
> +        unsigned long tmp = *src;
> +        *dst = tmp;
> +    } else {
> +        long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
> +        memmove(dst, src, len);
> +    }
> +}
> +
>  static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
>                               const unsigned long *src2, long nbits)
>  {
> -- 
> 1.9.1
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK