Re: [PATCH 1/2] x86: slightly simplify PHYSDEVOP_pirq_eoi_gmfn_v* handling

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 19/01/15 15:36, Jan Beulich wrote:
> We don't really need the MFN in more than one place (after dropping
> mfn_to_page() translations where we know the result already), so no
> need to have a local variable for it.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

>
> --- a/xen/arch/x86/physdev.c
> +++ b/xen/arch/x86/physdev.c
> @@ -336,7 +336,6 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
>      case PHYSDEVOP_pirq_eoi_gmfn_v2:
>      case PHYSDEVOP_pirq_eoi_gmfn_v1: {
>          struct physdev_pirq_eoi_gmfn info;
> -        unsigned long mfn;
>          struct page_info *page;
>  
>          ret = -EFAULT;
> @@ -352,21 +351,20 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
>              put_page(page);
>              break;
>          }
> -        mfn = page_to_mfn(page);
>  
>          if ( cmpxchg(&v->domain->arch.pirq_eoi_map_mfn,
> -                     0, mfn) != 0 )
> +                     0, page_to_mfn(page)) != 0 )
>          {
> -            put_page_and_type(mfn_to_page(mfn));
> +            put_page_and_type(page);
>              ret = -EBUSY;
>              break;
>          }
>  
> -        v->domain->arch.pirq_eoi_map = map_domain_page_global(mfn);
> +        v->domain->arch.pirq_eoi_map = __map_domain_page_global(page);
>          if ( v->domain->arch.pirq_eoi_map == NULL )
>          {
>              v->domain->arch.pirq_eoi_map_mfn = 0;
> -            put_page_and_type(mfn_to_page(mfn));
> +            put_page_and_type(page);
>              ret = -ENOSPC;
>              break;
>          }
>
>
>