diff --git a/drivers/char/agp/agp.h b/drivers/char/agp/agp.h
index ce110a3b..17e6d0d 100644
--- a/drivers/char/agp/agp.h
+++ b/drivers/char/agp/agp.h
@@ -121,6 +121,11 @@
 	void (*agp_destroy_pages)(struct agp_memory *);
 	int (*agp_type_to_mask_type) (struct agp_bridge_data *, int);
 	void (*chipset_flush)(struct agp_bridge_data *);
+
+	int (*agp_map_page)(void *addr, dma_addr_t *ret);
+	void (*agp_unmap_page)(void *addr, dma_addr_t dma);
+	int (*agp_map_memory)(struct agp_memory *mem);
+	void (*agp_unmap_memory)(struct agp_memory *mem);
 };
 
 struct agp_bridge_data {
@@ -135,6 +140,7 @@
 	u32 *gatt_table_real;
 	unsigned long scratch_page;
 	unsigned long scratch_page_real;
+	dma_addr_t scratch_page_dma;
 	unsigned long gart_bus_addr;
 	unsigned long gatt_bus_addr;
 	u32 mode;
diff --git a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c
index 3bd7e50..19ac366 100644
--- a/drivers/char/agp/backend.c
+++ b/drivers/char/agp/backend.c
@@ -152,6 +152,15 @@
 		bridge->scratch_page_real = phys_to_gart(page_to_phys(page));
 		bridge->scratch_page = bridge->driver->mask_memory(bridge,
 					   phys_to_gart(page_to_phys(page)), 0);
+
+		if (bridge->driver->agp_map_page &&
+		    bridge->driver->agp_map_page(phys_to_virt(page_to_phys(page)),
+						&bridge->scratch_page_dma)) {
+			dev_err(&bridge->dev->dev,
+				"unable to dma-map scratch page\n");
+			rc = -ENOMEM;
+			goto err_out_nounmap;
+		}
 	}
 
 	size_value = bridge->driver->fetch_size();
@@ -191,6 +200,13 @@
 	return 0;
 
 err_out:
+	if (bridge->driver->needs_scratch_page &&
+	    bridge->driver->agp_unmap_page) {
+		void *va = gart_to_virt(bridge->scratch_page_real);
+
+		bridge->driver->agp_unmap_page(va, bridge->scratch_page_dma);
+	}
+err_out_nounmap:
 	if (bridge->driver->needs_scratch_page) {
 		void *va = gart_to_virt(bridge->scratch_page_real);
 
@@ -221,6 +237,10 @@
 	    bridge->driver->needs_scratch_page) {
 		void *va = gart_to_virt(bridge->scratch_page_real);
 
+		if (bridge->driver->agp_unmap_page)
+			bridge->driver->agp_unmap_page(va,
+					       bridge->scratch_page_dma);
+
 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_UNMAP);
 		bridge->driver->agp_destroy_page(va, AGP_PAGE_DESTROY_FREE);
 	}
diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index a3bcc7e..28f0208 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -437,6 +437,12 @@
 		curr->bridge->driver->cache_flush();
 		curr->is_flushed = true;
 	}
+
+	if (curr->bridge->driver->agp_map_memory) {
+		ret_val = curr->bridge->driver->agp_map_memory(curr);
+		if (ret_val)
+			return ret_val;
+	}
 	ret_val = curr->bridge->driver->insert_memory(curr, pg_start, curr->type);
 
 	if (ret_val != 0)
@@ -478,6 +484,9 @@
 	if (ret_val != 0)
 		return ret_val;
 
+	if (curr->bridge->driver->agp_unmap_memory)
+		curr->bridge->driver->agp_unmap_memory(curr);
+
 	curr->is_bound = false;
 	curr->pg_start = 0;
 	spin_lock(&curr->bridge->mapped_lock);
diff --git a/include/linux/agp_backend.h b/include/linux/agp_backend.h
index 76fa794..8a294d6 100644
--- a/include/linux/agp_backend.h
+++ b/include/linux/agp_backend.h
@@ -79,9 +79,13 @@
 	u32 physical;
 	bool is_bound;
 	bool is_flushed;
-        bool vmalloc_flag;
+	bool vmalloc_flag;
+	bool sg_vmalloc_flag;
 	/* list of agp_memory mapped to the aperture */
 	struct list_head mapped_list;
+	/* DMA-mapped addresses */
+	struct scatterlist *sg_list;
+	int num_sg;
 };
 
 #define AGP_NORMAL_MEMORY 0