xen: introduce xen_dma_map/unmap_page and xen_dma_sync_single_for_cpu/device

Introduce xen_dma_map_page, xen_dma_unmap_page,
xen_dma_sync_single_for_cpu and xen_dma_sync_single_for_device.
They have empty implementations on x86 and ia64 but they call the
corresponding platform dma_ops function on arm and arm64.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

Changes in v9:
- xen_dma_map_page return void, avoid page_to_phys.

arch/arm/include/asm/xen/page-coherent.h

@@ -19,4 +19,32 @@ static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
 	__generic_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
 }
 
+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)
+{
+	if (__generic_dma_ops(hwdev)->unmap_page)
+		__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)
+{
+	if (__generic_dma_ops(hwdev)->sync_single_for_cpu)
+		__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)
+{
+	if (__generic_dma_ops(hwdev)->sync_single_for_device)
+		__generic_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
+}
 #endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */

arch/arm64/include/asm/xen/page-coherent.h

@@ -19,4 +19,29 @@ static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
 	__generic_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
 }
 
+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 */

arch/ia64/include/asm/xen/page-coherent.h

@@ -21,4 +21,18 @@ static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
 	free_pages((unsigned long) cpu_addr, get_order(size));
 }
 
+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) { }
+
+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) { }
+
+static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
+		dma_addr_t handle, size_t size, enum dma_data_direction 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) { }
+
 #endif /* _ASM_IA64_XEN_PAGE_COHERENT_H */

arch/x86/include/asm/xen/page-coherent.h

@@ -21,4 +21,18 @@ static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
 	free_pages((unsigned long) cpu_addr, get_order(size));
 }
 
+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) { }
+
+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) { }
+
+static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
+		dma_addr_t handle, size_t size, enum dma_data_direction 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) { }
+
 #endif /* _ASM_X86_XEN_PAGE_COHERENT_H */