xen/arm: call dma_to_phys on the dma_addr_t parameter of dma_cache_maint

dma_cache_maint is getting called passing a dma address which could be
different from a physical address.

Add a struct device* parameter to dma_cache_maint.

Translate the dma_addr_t parameter of dma_cache_maint by calling
dma_to_phys. Do it for the first page and all the following pages, in
case of multipage handling.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Corey Minyard <cminyard@mvista.com>
Tested-by: Roman Shaposhnik <roman@zededa.com>
Link: https://lore.kernel.org/r/20200710223427.6897-11-sstabellini@kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>

arch/arm/xen/mm.c

@@ -43,15 +43,18 @@ unsigned long xen_get_swiotlb_free_pages(unsigned int order)
 static bool hypercall_cflush = false;
 
 /* buffers in highmem or foreign pages cannot cross page boundaries */
-static void dma_cache_maint(dma_addr_t handle, size_t size, u32 op)
+static void dma_cache_maint(struct device *dev, dma_addr_t handle,
+			    size_t size, u32 op)
 {
 	struct gnttab_cache_flush cflush;
 
-	cflush.a.dev_bus_addr = handle & XEN_PAGE_MASK;
 	cflush.offset = xen_offset_in_page(handle);
 	cflush.op = op;
+	handle &= XEN_PAGE_MASK;
 
 	do {
+		cflush.a.dev_bus_addr = dma_to_phys(dev, handle);
+
 		if (size + cflush.offset > XEN_PAGE_SIZE)
 			cflush.length = XEN_PAGE_SIZE - cflush.offset;
 		else
@@ -60,7 +63,7 @@ static void dma_cache_maint(dma_addr_t handle, size_t size, u32 op)
 		HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1);
 
 		cflush.offset = 0;
-		cflush.a.dev_bus_addr += cflush.length;
+		handle += cflush.length;
 		size -= cflush.length;
 	} while (size);
 }
@@ -76,16 +79,16 @@ void xen_dma_sync_for_cpu(struct device *dev, dma_addr_t handle,
 			  size_t size, enum dma_data_direction dir)
 {
 	if (dir != DMA_TO_DEVICE)
-		dma_cache_maint(handle, size, GNTTAB_CACHE_INVAL);
+		dma_cache_maint(dev, handle, size, GNTTAB_CACHE_INVAL);
 }
 
 void xen_dma_sync_for_device(struct device *dev, dma_addr_t handle,
 			     size_t size, enum dma_data_direction dir)
 {
 	if (dir == DMA_FROM_DEVICE)
-		dma_cache_maint(handle, size, GNTTAB_CACHE_INVAL);
+		dma_cache_maint(dev, handle, size, GNTTAB_CACHE_INVAL);
 	else
-		dma_cache_maint(handle, size, GNTTAB_CACHE_CLEAN);
+		dma_cache_maint(dev, handle, size, GNTTAB_CACHE_CLEAN);
 }
 
 bool xen_arch_need_swiotlb(struct device *dev,