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

From: Catalin Marinas
Date: Mon Nov 10 2014 - 13:41:26 EST


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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