[PATCH 2/8] xen-swiotlb: use is_swiotlb_buffer in is_xen_swiotlb_buffer

[Konrad Rzeszutek Wilk]

On Sun, Feb 07, 2021 at 05:09:28PM +0100, Christoph Hellwig wrote:
> Use the is_swiotlb_buffer to check if a physical address is
> a swiotlb buffer.  This works because xen-swiotlb does use the
> same buffer as the main swiotlb code, and xen_io_tlb_{start,end}
> are just the addresses for it that went through phys_to_virt.
> 

Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>

> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>  drivers/xen/swiotlb-xen.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
> index 2b385c1b4a99cb..a4026822a889f7 100644
> --- a/drivers/xen/swiotlb-xen.c
> +++ b/drivers/xen/swiotlb-xen.c
> @@ -111,10 +111,8 @@ static int is_xen_swiotlb_buffer(struct device *dev, dma_addr_t dma_addr)
>  	 * have the same virtual address as another address
>  	 * in our domain. Therefore _only_ check address within our domain.
>  	 */
> -	if (pfn_valid(PFN_DOWN(paddr))) {
> -		return paddr >= virt_to_phys(xen_io_tlb_start) &&
> -		       paddr < virt_to_phys(xen_io_tlb_end);
> -	}
> +	if (pfn_valid(PFN_DOWN(paddr)))
> +		return is_swiotlb_buffer(paddr);
>  	return 0;
>  }
>  
> -- 
> 2.29.2
>