1 files changed, 76 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/xen/page-coherent.h b/arch/arm64/include/asm/xen/page-coherent.h
index b3ef061d8b74..d88e56b90b93 100644
--- a/arch/arm64/include/asm/xen/page-coherent.h
+++ b/arch/arm64/include/asm/xen/page-coherent.h
@@ -1 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_ARM64_XEN_PAGE_COHERENT_H
+#define _ASM_ARM64_XEN_PAGE_COHERENT_H
+
+#include <linux/dma-mapping.h>
+#include <asm/page.h>
 #include <xen/arm/page-coherent.h>
+
+static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
+                dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
+{
+        return dma_direct_alloc(hwdev, size, dma_handle, flags, attrs);
+}
+
+static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
+                void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
+{
+        dma_direct_free(hwdev, size, cpu_addr, dma_handle, 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)
+{
+        unsigned long pfn = PFN_DOWN(handle);
+
+        if (pfn_valid(pfn))
+                dma_direct_sync_single_for_cpu(hwdev, handle, size, dir);
+        else
+                __xen_dma_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)
+{
+        unsigned long pfn = PFN_DOWN(handle);
+        if (pfn_valid(pfn))
+                dma_direct_sync_single_for_device(hwdev, handle, size, dir);
+        else
+                __xen_dma_sync_single_for_device(hwdev, handle, size, dir);
+}
+
+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);
+
+        if (local)
+                dma_direct_map_page(hwdev, page, offset, size, dir, attrs);
+        else
+                __xen_dma_map_page(hwdev, page, dev_addr, 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, 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
+                __xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
+}
+
+#endif /* _ASM_ARM64_XEN_PAGE_COHERENT_H */