diff options
Diffstat (limited to 'include/xen/arm')
| -rw-r--r-- | include/xen/arm/page-coherent.h | 31 |
1 files changed, 9 insertions, 22 deletions
diff --git a/include/xen/arm/page-coherent.h b/include/xen/arm/page-coherent.h index a840d6949a87..a8d9c0678c27 100644 --- a/include/xen/arm/page-coherent.h +++ b/include/xen/arm/page-coherent.h @@ -53,23 +53,17 @@ static inline void xen_dma_map_page(struct device *hwdev, struct page *page, dma_addr_t dev_addr, unsigned long offset, size_t size, enum dma_data_direction dir, unsigned long attrs) { - unsigned long page_pfn = page_to_xen_pfn(page); - unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr); - unsigned long compound_pages = - (1<<compound_order(page)) * XEN_PFN_PER_PAGE; - bool local = (page_pfn <= dev_pfn) && - (dev_pfn - page_pfn < compound_pages); + unsigned long pfn = PFN_DOWN(dev_addr); /* - * Dom0 is mapped 1:1, while the Linux page can span across - * multiple Xen pages, it's not possible for it to contain a - * mix of local and foreign Xen pages. So if the first xen_pfn - * == mfn the page is local otherwise it's a foreign page - * grant-mapped in dom0. If the page is local we can safely - * call the native dma_ops function, otherwise we call the xen - * specific function. + * Dom0 is mapped 1:1, and while the Linux page can span across multiple + * Xen pages, it is not possible for it to contain a mix of local and + * foreign Xen pages. Calling pfn_valid on a foreign mfn will always + * return false, so if pfn_valid returns true the pages is local and we + * can use the native dma-direct functions, otherwise we call the Xen + * specific version. */ - if (local) + if (pfn_valid(pfn)) dma_direct_map_page(hwdev, page, offset, size, dir, attrs); else __xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs); @@ -79,14 +73,7 @@ static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir, unsigned long attrs) { unsigned long pfn = PFN_DOWN(handle); - /* - * Dom0 is mapped 1:1, while the Linux page can be spanned accross - * multiple Xen page, it's not possible to have a mix of local and - * foreign Xen page. 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)) dma_direct_unmap_page(hwdev, handle, size, dir, attrs); else |