drm/nouveau: make fifo.create_context() responsible for mapping control regs

The regs belong to PFIFO, they're different for pretty much the same
generations we need different PFIFO control for, and NVC0 is going
to be even more different than the rest.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nv10_fifo.c b/drivers/gpu/drm/nouveau/nv10_fifo.c
index acb9216..d2ecbff 100644
--- a/drivers/gpu/drm/nouveau/nv10_fifo.c
+++ b/drivers/gpu/drm/nouveau/nv10_fifo.c
@@ -53,6 +53,11 @@
 	if (ret)
 		return ret;
 
+	chan->user = ioremap(pci_resource_start(dev->pdev, 0) +
+			     NV03_USER(chan->id), PAGE_SIZE);
+	if (!chan->user)
+		return -ENOMEM;
+
 	/* Fill entries that are seen filled in dumps of nvidia driver just
 	 * after channel's is put into DMA mode
 	 */