ttm: fix agp since ttm tt rework

ttm tt rework modified the way we allocate and populate the
ttm_tt structure, the AGP side was missing some bit to properly
work. Fix those and fix radeon and nouveau AGP support.

Tested on radeon only so far.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 8cf4a48..724b41a 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1066,6 +1066,12 @@
 	dev_priv = nouveau_bdev(ttm->bdev);
 	dev = dev_priv->dev;
 
+#if __OS_HAS_AGP
+	if (dev_priv->gart_info.type == NOUVEAU_GART_AGP) {
+		return ttm_agp_tt_populate(ttm);
+	}
+#endif
+
 #ifdef CONFIG_SWIOTLB
 	if (swiotlb_nr_tbl()) {
 		return ttm_dma_populate((void *)ttm, dev->dev);
@@ -1105,6 +1111,13 @@
 	dev_priv = nouveau_bdev(ttm->bdev);
 	dev = dev_priv->dev;
 
+#if __OS_HAS_AGP
+	if (dev_priv->gart_info.type == NOUVEAU_GART_AGP) {
+		ttm_agp_tt_unpopulate(ttm);
+		return;
+	}
+#endif
+
 #ifdef CONFIG_SWIOTLB
 	if (swiotlb_nr_tbl()) {
 		ttm_dma_unpopulate((void *)ttm, dev->dev);