[PATCH v8 03/13] xen/arm: if(pfn_valid(pfn)) call native dma_ops

Catalin Marinas catalin.marinas at arm.com
Mon Nov 10 10:41:11 PST 2014


On Mon, Nov 10, 2014 at 04:13:55PM +0000, Stefano Stabellini wrote:
>  void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
>  		size_t size, enum dma_data_direction dir,
> -		struct dma_attrs *attrs);
> +		struct dma_attrs *attrs)
> +{
> +	unsigned long pfn = PFN_DOWN(handle);
> +	/* Dom0 is mapped 1:1, so calling pfn_valid on a foreign mfn will
> +	 * always return false. If the page is local we can safely call the
> +	 * native dma_ops function, otherwise we call the xen specific
> +	 * function. */
> +	if (pfn_valid(pfn)) {
> +		if (__generic_dma_ops(hwdev)->unmap_page)
> +			__generic_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);

Similarly here, do we need the unmap_page check? dma_map_page() does not
do it.

-- 
Catalin



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