| Message ID | 1386605160-3185-1-git-send-email-stefano.stabellini@eu.citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 2013-12-09 at 16:06 +0000, Stefano Stabellini wrote: > On arm64 the dma_map_ops implementation is based on the swiotlb. > swiotlb-xen, used by default in dom0 on Xen, is also based on the > swiotlb. > > Avoid calling into the default arm64 dma_map_ops functions from > xen_dma_map_page, xen_dma_unmap_page, xen_dma_sync_single_for_cpu, and > xen_dma_sync_single_for_device otherwise we end up calling into the > swiotlb twice. > > When arm64 gets a non-swiotlb based implementation of dma_map_ops, we'll > probably have to reintroduce dma_map_ops calls in page-coherent.h. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > CC: catalin.marinas@arm.com > CC: Will.Deacon@arm.com Tested-by: Ian Campbell <ian.campbell@citrix.com> Ian.
diff --git a/arch/arm64/include/asm/xen/page-coherent.h b/arch/arm64/include/asm/xen/page-coherent.h index 2820f1a..dde3fc9 100644 --- a/arch/arm64/include/asm/xen/page-coherent.h +++ b/arch/arm64/include/asm/xen/page-coherent.h @@ -23,25 +23,21 @@ static inline void xen_dma_map_page(struct device *hwdev, struct page *page, unsigned long offset, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs) { - __generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs); } static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs) { - __generic_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs); } static inline void xen_dma_sync_single_for_cpu(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - __generic_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir); } static inline void xen_dma_sync_single_for_device(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - __generic_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir); } #endif /* _ASM_ARM64_XEN_PAGE_COHERENT_H */
On arm64 the dma_map_ops implementation is based on the swiotlb. swiotlb-xen, used by default in dom0 on Xen, is also based on the swiotlb. Avoid calling into the default arm64 dma_map_ops functions from xen_dma_map_page, xen_dma_unmap_page, xen_dma_sync_single_for_cpu, and xen_dma_sync_single_for_device otherwise we end up calling into the swiotlb twice. When arm64 gets a non-swiotlb based implementation of dma_map_ops, we'll probably have to reintroduce dma_map_ops calls in page-coherent.h. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> CC: catalin.marinas@arm.com CC: Will.Deacon@arm.com CC: Ian.Campbell@citrix.com --- arch/arm64/include/asm/xen/page-coherent.h | 4 ---- 1 file changed, 4 deletions(-)