diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index c7320ce..28f3fcf 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1581,7 +1581,8 @@ void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
 
 	if (!bdev->dev_mapping)
 		return;
-
+	if (bdev->driver->io_mem_free)
+		bdev->driver->io_mem_free(bdev, &bo->mem);
 	unmap_mapping_range(bdev->dev_mapping, offset, holelen, 1);
 }
 EXPORT_SYMBOL(ttm_bo_unmap_virtual);
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 3f72fe1..10c5fc6 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -84,26 +84,36 @@ int ttm_mem_reg_ioremap(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem,
 			void **virtual)
 {
 	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
-	unsigned long bus_offset;
-	unsigned long bus_size;
-	unsigned long bus_base;
+	struct ttm_bus_placement pl;
 	int ret;
 	void *addr;
 
 	*virtual = NULL;
-	ret = ttm_bo_pci_offset(bdev, mem, &bus_base, &bus_offset, &bus_size);
-	if (ret || bus_size == 0)
-		return ret;
+	if (bdev->driver->io_mem_reserve) {
+		ret = bdev->driver->io_mem_reserve(bdev, mem, &pl);
+		if (unlikely(ret != 0)) {
+			return ret;
+		}
+	} else {
+		ret = ttm_bo_pci_offset(bdev, mem, &pl.base, &pl.offset, &pl.size);
+		if (unlikely(ret != 0) || pl.size == 0) {
+			return ret;
+		}
+		pl.is_iomem = (pl.size != 0);
+	}
 
 	if (!(man->flags & TTM_MEMTYPE_FLAG_NEEDS_IOREMAP))
-		addr = (void *)(((u8 *) man->io_addr) + bus_offset);
+		addr = (void *)(pl.base + pl.offset);
 	else {
 		if (mem->placement & TTM_PL_FLAG_WC)
-			addr = ioremap_wc(bus_base + bus_offset, bus_size);
+			addr = ioremap_wc(pl.base + pl.offset, pl.size);
 		else
-			addr = ioremap_nocache(bus_base + bus_offset, bus_size);
-		if (!addr)
+			addr = ioremap_nocache(pl.base + pl.offset, pl.size);
+		if (!addr) {
+			if (bdev->driver->io_mem_free)
+				bdev->driver->io_mem_free(bdev, mem);
 			return -ENOMEM;
+		}
 	}
 	*virtual = addr;
 	return 0;
@@ -118,6 +128,8 @@ void ttm_mem_reg_iounmap(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem,
 
 	if (virtual && (man->flags & TTM_MEMTYPE_FLAG_NEEDS_IOREMAP))
 		iounmap(virtual);
+	if (bdev->driver->io_mem_free)
+		bdev->driver->io_mem_free(bdev, mem);
 }
 
 static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
@@ -440,13 +452,12 @@ int ttm_bo_kmap(struct ttm_buffer_object *bo,
 		unsigned long start_page, unsigned long num_pages,
 		struct ttm_bo_kmap_obj *map)
 {
+	struct ttm_bus_placement pl;
 	int ret;
-	unsigned long bus_base;
-	unsigned long bus_offset;
-	unsigned long bus_size;
 
 	BUG_ON(!list_empty(&bo->swap));
 	map->virtual = NULL;
+	map->bo = bo;
 	if (num_pages > bo->num_pages)
 		return -EINVAL;
 	if (start_page > bo->num_pages)
@@ -455,16 +466,24 @@ int ttm_bo_kmap(struct ttm_buffer_object *bo,
 	if (num_pages > 1 && !DRM_SUSER(DRM_CURPROC))
 		return -EPERM;
 #endif
-	ret = ttm_bo_pci_offset(bo->bdev, &bo->mem, &bus_base,
-				&bus_offset, &bus_size);
-	if (ret)
-		return ret;
-	if (bus_size == 0) {
+	if (bo->bdev->driver->io_mem_reserve) {
+		ret = bo->bdev->driver->io_mem_reserve(bo->bdev, &bo->mem, &pl);
+		if (unlikely(ret != 0)) {
+			return ret;
+		}
+	} else {
+		ret = ttm_bo_pci_offset(bo->bdev, &bo->mem, &pl.base, &pl.offset, &pl.size);
+		if (unlikely(ret != 0)) {
+			return ret;
+		}
+		pl.is_iomem = (pl.size != 0);
+	}
+	if (!pl.is_iomem) {
 		return ttm_bo_kmap_ttm(bo, start_page, num_pages, map);
 	} else {
-		bus_offset += start_page << PAGE_SHIFT;
-		bus_size = num_pages << PAGE_SHIFT;
-		return ttm_bo_ioremap(bo, bus_base, bus_offset, bus_size, map);
+		pl.offset += start_page << PAGE_SHIFT;
+		pl.size = num_pages << PAGE_SHIFT;
+		return ttm_bo_ioremap(bo, pl.base, pl.offset, pl.size, map);
 	}
 }
 EXPORT_SYMBOL(ttm_bo_kmap);
@@ -476,6 +495,8 @@ void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
 	switch (map->bo_kmap_type) {
 	case ttm_bo_map_iomap:
 		iounmap(map->virtual);
+		if (map->bo->bdev->driver->io_mem_free)
+			map->bo->bdev->driver->io_mem_free(map->bo->bdev, &map->bo->mem);
 		break;
 	case ttm_bo_map_vmap:
 		vunmap(map->virtual);
@@ -493,35 +514,6 @@ void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
 }
 EXPORT_SYMBOL(ttm_bo_kunmap);
 
-int ttm_bo_pfn_prot(struct ttm_buffer_object *bo,
-		    unsigned long dst_offset,
-		    unsigned long *pfn, pgprot_t *prot)
-{
-	struct ttm_mem_reg *mem = &bo->mem;
-	struct ttm_bo_device *bdev = bo->bdev;
-	unsigned long bus_offset;
-	unsigned long bus_size;
-	unsigned long bus_base;
-	int ret;
-	ret = ttm_bo_pci_offset(bdev, mem, &bus_base, &bus_offset,
-			&bus_size);
-	if (ret)
-		return -EINVAL;
-	if (bus_size != 0)
-		*pfn = (bus_base + bus_offset + dst_offset) >> PAGE_SHIFT;
-	else
-		if (!bo->ttm)
-			return -EINVAL;
-		else
-			*pfn = page_to_pfn(ttm_tt_get_page(bo->ttm,
-							   dst_offset >>
-							   PAGE_SHIFT));
-	*prot = (mem->placement & TTM_PL_FLAG_CACHED) ?
-		PAGE_KERNEL : ttm_io_prot(mem->placement, PAGE_KERNEL);
-
-	return 0;
-}
-
 int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
 			      void *sync_obj,
 			      void *sync_obj_arg,
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 668dbe8..fe4ac95 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -74,9 +74,7 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
 	    vma->vm_private_data;
 	struct ttm_bo_device *bdev = bo->bdev;
-	unsigned long bus_base;
-	unsigned long bus_offset;
-	unsigned long bus_size;
+	struct ttm_bus_placement pl;
 	unsigned long page_offset;
 	unsigned long page_last;
 	unsigned long pfn;
@@ -84,7 +82,6 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	struct page *page;
 	int ret;
 	int i;
-	bool is_iomem;
 	unsigned long address = (unsigned long)vmf->virtual_address;
 	int retval = VM_FAULT_NOPAGE;
 
@@ -104,11 +101,33 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	if (bdev->driver->fault_reserve_notify)
 		bdev->driver->fault_reserve_notify(bo);
 
+	if (bdev->driver->fault_reserve) {
+		ret = bdev->driver->fault_reserve(bo, &pl);
+		switch (ret) {
+		case 0:
+			break;
+		case -EBUSY:
+			set_need_resched();
+		case -ERESTARTSYS:
+			retval = VM_FAULT_NOPAGE;
+			goto out_unlock;
+		default:
+			retval = VM_FAULT_SIGBUS;
+			goto out_unlock;
+		}
+	} else {
+		ret = ttm_bo_pci_offset(bdev, &bo->mem, &pl.base, &pl.offset, &pl.size);
+		if (unlikely(ret != 0)) {
+			retval = VM_FAULT_SIGBUS;
+			goto out_unlock;
+		}
+		pl.is_iomem = (pl.size != 0);
+	}
+
 	/*
 	 * Wait for buffer data in transit, due to a pipelined
 	 * move.
 	 */
-
 	spin_lock(&bo->lock);
 	if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
 		ret = ttm_bo_wait(bo, false, true, false);
@@ -122,20 +141,10 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		spin_unlock(&bo->lock);
 
 
-	ret = ttm_bo_pci_offset(bdev, &bo->mem, &bus_base, &bus_offset,
-				&bus_size);
-	if (unlikely(ret != 0)) {
-		retval = VM_FAULT_SIGBUS;
-		goto out_unlock;
-	}
-
-	is_iomem = (bus_size != 0);
-
 	page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 	    bo->vm_node->start - vma->vm_pgoff;
 	page_last = ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) +
 	    bo->vm_node->start - vma->vm_pgoff;
-
 	if (unlikely(page_offset >= bo->num_pages)) {
 		retval = VM_FAULT_SIGBUS;
 		goto out_unlock;
@@ -154,8 +163,7 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	 * vma->vm_page_prot when the object changes caching policy, with
 	 * the correct locks held.
 	 */
-
-	if (is_iomem) {
+	if (pl.is_iomem) {
 		vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
 						vma->vm_page_prot);
 	} else {
@@ -169,12 +177,9 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	 * Speculatively prefault a number of pages. Only error on
 	 * first page.
 	 */
-
 	for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
-
-		if (is_iomem)
-			pfn = ((bus_base + bus_offset) >> PAGE_SHIFT) +
-			    page_offset;
+		if (pl.is_iomem)
+			pfn = ((pl.base + pl.offset) >> PAGE_SHIFT) + page_offset;
 		else {
 			page = ttm_tt_get_page(ttm, page_offset);
 			if (unlikely(!page && i == 0)) {
@@ -191,14 +196,12 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		 * Somebody beat us to this PTE or prefaulting to
 		 * an already populated PTE, or prefaulting error.
 		 */
-
 		if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 			break;
 		else if (unlikely(ret != 0)) {
 			retval =
 			    (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 			goto out_unlock;
-
 		}
 
 		address += PAGE_SIZE;
@@ -221,9 +224,10 @@ static void ttm_bo_vm_open(struct vm_area_struct *vma)
 
 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 {
-	struct ttm_buffer_object *bo =
-	    (struct ttm_buffer_object *)vma->vm_private_data;
+	struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
 
+	if (bo->bdev->driver->io_mem_free)
+		bo->bdev->driver->io_mem_free(bo->bdev, &bo->mem);
 	ttm_bo_unref(&bo);
 	vma->vm_private_data = NULL;
 }
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 81eb9f4..1b38c67 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -274,6 +274,7 @@ struct ttm_bo_kmap_obj {
 		ttm_bo_map_kmap         = 3,
 		ttm_bo_map_premapped    = 4 | TTM_BO_MAP_IOMEM_MASK,
 	} bo_kmap_type;
+	struct ttm_buffer_object *bo;
 };
 
 /**
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index 4c4e0f8..923fecf 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -240,6 +240,23 @@ struct ttm_mem_type_manager {
 };
 
 /**
+ * struct ttm_bus_placement
+ *
+ * @base:		bus base address
+ * @is_iomem:		is this io memory ?
+ * @size:		size in byte
+ * @offset:		offset from the base address
+ *
+ * Structure indicating the bus placement of an object.
+ */
+struct ttm_bus_placement {
+	unsigned long	base;
+	unsigned long	size;
+	unsigned long	offset;
+	bool		is_iomem;
+};
+
+/**
  * struct ttm_bo_driver
  *
  * @create_ttm_backend_entry: Callback to create a struct ttm_backend.
@@ -358,6 +375,19 @@ struct ttm_bo_driver {
 	 * notify the driver that we're about to swap out this bo
 	 */
 	void (*swap_notify) (struct ttm_buffer_object *bo);
+
+	/**
+	 * Driver callback on bo fault, driver is responsible to fill the
+	 * bus placement and has the opportunity to move the buffer into
+	 * visible space.
+	 */
+	int (*fault_reserve)(struct ttm_buffer_object *bo, struct ttm_bus_placement *pl);
+	/**
+	 * Driver callback on when mapping io memory (for bo_move_memcpy for instance).
+	 * TTM will take care to call io_mem_free whenever the mapping is not use anymore.
+	 */
+	int (*io_mem_reserve)(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem, struct ttm_bus_placement *pl);
+	void (*io_mem_free)(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem);
 };
 
 /**
