1 files changed, 57 insertions, 9 deletions

diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h
index e8275ea88e88..efd562412850 100644
--- a/arch/arm/include/asm/xen/page-coherent.h
+++ b/arch/arm/include/asm/xen/page-coherent.h
@@ -5,6 +5,18 @@
 #include <linux/dma-attrs.h>
 #include <linux/dma-mapping.h>
 
+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, struct dma_attrs *attrs);
+void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
+                size_t size, enum dma_data_direction dir,
+                struct dma_attrs *attrs);
+void __xen_dma_sync_single_for_cpu(struct device *hwdev,
+                dma_addr_t handle, size_t size, enum dma_data_direction dir);
+
+void __xen_dma_sync_single_for_device(struct device *hwdev,
+                dma_addr_t handle, size_t size, enum dma_data_direction dir);
+
 static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
                 dma_addr_t *dma_handle, gfp_t flags,
                 struct dma_attrs *attrs)
@@ -20,20 +32,56 @@ static inline void xen_free_coherent_pages(struct device *hwdev, size_t 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)
+             dma_addr_t dev_addr, 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);
+        bool local = PFN_DOWN(dev_addr) == page_to_pfn(page);
+        /* Dom0 is mapped 1:1, so if pfn == mfn the page is local otherwise
+         * is 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. */
+        if (local)
+                __generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
+        else
+                __xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
 }
 
-void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
+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);
+                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);
+        } else
+                __xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
+}
 
-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_cpu(struct device *hwdev,
+                dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+        unsigned long pfn = PFN_DOWN(handle);
+        if (pfn_valid(pfn)) {
+                if (__generic_dma_ops(hwdev)->sync_single_for_cpu)
+                        __generic_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
+        } else
+                __xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
+}
 
-void xen_dma_sync_single_for_device(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)
+{
+        unsigned long pfn = PFN_DOWN(handle);
+        if (pfn_valid(pfn)) {
+                if (__generic_dma_ops(hwdev)->sync_single_for_device)
+                        __generic_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
+        } else
+                __xen_dma_sync_single_for_device(hwdev, handle, size, dir);
+}
 
 #endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */