firewire-ohci: use dma_alloc_pages

Use dma_alloc_pages to allocate DMAable pages instead of hoping that
the architecture either has GFP_DMA32 or not more than 4G of memory.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

drivers/firewire/ohci.c

@@ -674,17 +674,16 @@ static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
 
 static void ar_context_release(struct ar_context *ctx)
 {
+	struct device *dev = ctx->ohci->card.device;
 	unsigned int i;
 
 	vunmap(ctx->buffer);
 
-	for (i = 0; i < AR_BUFFERS; i++)
-		if (ctx->pages[i]) {
-			dma_unmap_page(ctx->ohci->card.device,
-				       ar_buffer_bus(ctx, i),
-				       PAGE_SIZE, DMA_FROM_DEVICE);
-			__free_page(ctx->pages[i]);
-		}
+	for (i = 0; i < AR_BUFFERS; i++) {
+		if (ctx->pages[i])
+			dma_free_pages(dev, PAGE_SIZE, ctx->pages[i],
+				       ar_buffer_bus(ctx, i), DMA_FROM_DEVICE);
+	}
 }
 
 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
@@ -970,6 +969,7 @@ static void ar_context_tasklet(unsigned long data)
 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
 			   unsigned int descriptors_offset, u32 regs)
 {
+	struct device *dev = ohci->card.device;
 	unsigned int i;
 	dma_addr_t dma_addr;
 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
@@ -980,17 +980,13 @@ static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
 
 	for (i = 0; i < AR_BUFFERS; i++) {
-		ctx->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32);
+		ctx->pages[i] = dma_alloc_pages(dev, PAGE_SIZE, &dma_addr,
+						DMA_FROM_DEVICE, GFP_KERNEL);
 		if (!ctx->pages[i])
 			goto out_of_memory;
-		dma_addr = dma_map_page(ohci->card.device, ctx->pages[i],
-					0, PAGE_SIZE, DMA_FROM_DEVICE);
-		if (dma_mapping_error(ohci->card.device, dma_addr)) {
-			__free_page(ctx->pages[i]);
-			ctx->pages[i] = NULL;
-			goto out_of_memory;
-		}
 		set_page_private(ctx->pages[i], dma_addr);
+		dma_sync_single_for_device(dev, dma_addr, PAGE_SIZE,
+					   DMA_FROM_DEVICE);
 	}
 
 	for (i = 0; i < AR_BUFFERS; i++)