swiotlb: use dma_capable()

This converts swiotlb to use dma_capable() instead of
swiotlb_arch_address_needs_mapping() and is_buffer_dma_capable().
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NBecky Bruce <beckyb@kernel.crashing.org>

lib/swiotlb.c

@@ -131,12 +131,6 @@ static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
 	return swiotlb_phys_to_bus(hwdev, virt_to_phys(address));
 }
 
-int __weak swiotlb_arch_address_needs_mapping(struct device *hwdev,
-					       dma_addr_t addr, size_t size)
-{
-	return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
-}
-
 static void swiotlb_print_info(unsigned long bytes)
 {
 	phys_addr_t pstart, pend;
@@ -297,12 +291,6 @@ swiotlb_late_init_with_default_size(size_t default_size)
 	return -ENOMEM;
 }
 
-static inline int
-address_needs_mapping(struct device *hwdev, dma_addr_t addr, size_t size)
-{
-	return swiotlb_arch_address_needs_mapping(hwdev, addr, size);
-}
-
 static int is_swiotlb_buffer(phys_addr_t paddr)
 {
 	return paddr >= virt_to_phys(io_tlb_start) &&
@@ -539,9 +527,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 		dma_mask = hwdev->coherent_dma_mask;
 
 	ret = (void *)__get_free_pages(flags, order);
-	if (ret &&
-	    !is_buffer_dma_capable(dma_mask, swiotlb_virt_to_bus(hwdev, ret),
-				   size)) {
+	if (ret && swiotlb_virt_to_bus(hwdev, ret) + size > dma_mask) {
 		/*
 		 * The allocated memory isn't reachable by the device.
 		 */
@@ -563,7 +549,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 	dev_addr = swiotlb_virt_to_bus(hwdev, ret);
 
 	/* Confirm address can be DMA'd by device */
-	if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
+	if (dev_addr + size > dma_mask) {
 		printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
 		       (unsigned long long)dma_mask,
 		       (unsigned long long)dev_addr);
@@ -635,7 +621,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
 	 * we can safely return the device addr and not worry about bounce
 	 * buffering it.
 	 */
-	if (!address_needs_mapping(dev, dev_addr, size) && !swiotlb_force)
+	if (dma_capable(dev, dev_addr, size) && !swiotlb_force)
 		return dev_addr;
 
 	/*
@@ -652,7 +638,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
 	/*
 	 * Ensure that the address returned is DMA'ble
 	 */
-	if (address_needs_mapping(dev, dev_addr, size))
+	if (!dma_capable(dev, dev_addr, size))
 		panic("map_single: bounce buffer is not DMA'ble");
 
 	return dev_addr;
@@ -805,7 +791,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
 		dma_addr_t dev_addr = swiotlb_phys_to_bus(hwdev, paddr);
 
 		if (swiotlb_force ||
-		    address_needs_mapping(hwdev, dev_addr, sg->length)) {
+		    !dma_capable(hwdev, dev_addr, sg->length)) {
 			void *map = map_single(hwdev, sg_phys(sg),
 					       sg->length, dir);
 			if (!map) {