drm/nv50: fix instmem init on IGPs if stolen mem crosses 4GiB mark

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nv50_instmem.c b/drivers/gpu/drm/nouveau/nv50_instmem.c
index 34280eb..5f21df3 100644
--- a/drivers/gpu/drm/nouveau/nv50_instmem.c
+++ b/drivers/gpu/drm/nouveau/nv50_instmem.c
@@ -63,9 +63,10 @@
 	struct drm_nouveau_private *dev_priv = dev->dev_private;
 	struct nouveau_channel *chan;
 	uint32_t c_offset, c_size, c_ramfc, c_vmpd, c_base, pt_size;
+	uint32_t save_nv001700;
+	uint64_t v;
 	struct nv50_instmem_priv *priv;
 	int ret, i;
-	uint32_t v, save_nv001700;
 
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -184,8 +185,8 @@
 
 	i = 0;
 	while (v < dev_priv->vram_sys_base + c_offset + c_size) {
-		BAR0_WI32(priv->pramin_pt->gpuobj, i + 0, v);
-		BAR0_WI32(priv->pramin_pt->gpuobj, i + 4, 0x00000000);
+		BAR0_WI32(priv->pramin_pt->gpuobj, i + 0, lower_32_bits(v));
+		BAR0_WI32(priv->pramin_pt->gpuobj, i + 4, upper_32_bits(v));
 		v += 0x1000;
 		i += 8;
 	}