Re: [PATCH] virtio, ring: Use ALIGN macros in virtio_ring.h

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Apr 26, 2011 at 12:11:10PM +0800, Liu Yuan wrote:
> From: Liu Yuan <tailai.ly@taobao.com>
> 
> 
> Signed-off-by: Liu Yuan <tailai.ly@taobao.com>

Issue is, these functions are exported to userspace,
which does not have these macros.

> ---
>  include/linux/virtio_ring.h |    8 +++-----
>  1 files changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
> index e4d144b..6299050 100644
> --- a/include/linux/virtio_ring.h
> +++ b/include/linux/virtio_ring.h
> @@ -99,15 +99,13 @@ static inline void vring_init(struct vring *vr, unsigned int num, void *p,
>  	vr->num = num;
>  	vr->desc = p;
>  	vr->avail = p + num*sizeof(struct vring_desc);
> -	vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + align-1)
> -			    & ~(align - 1));
> +	vr->used = (void *)PTR_ALIGN(&vr->avail->ring[num], align);
>  }
>  
>  static inline unsigned vring_size(unsigned int num, unsigned long align)
>  {
> -	return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (2 + num)
> -		 + align - 1) & ~(align - 1))
> -		+ sizeof(__u16) * 2 + sizeof(struct vring_used_elem) * num;
> +	return ((sizeof(struct vring_desc) * num + ALIGN(sizeof(__u16) * (2 + num), align))
> +		+ sizeof(__u16) * 2 + sizeof(struct vring_used_elem) * num);
>  }
>  
>  #ifdef __KERNEL__
> -- 
> 1.7.1