drm/nouveau: require explicit unmap of kmapped bos

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index ab661f459..841c63f 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -58,8 +58,6 @@
 	struct drm_device *dev = dev_priv->dev;
 	struct nouveau_bo *nvbo = nouveau_bo(bo);
 
-	ttm_bo_kunmap(&nvbo->kmap);
-
 	if (unlikely(nvbo->gem))
 		DRM_ERROR("bo %p still attached to GEM object\n", bo);
 
@@ -305,7 +303,8 @@
 void
 nouveau_bo_unmap(struct nouveau_bo *nvbo)
 {
-	ttm_bo_kunmap(&nvbo->kmap);
+	if (nvbo)
+		ttm_bo_kunmap(&nvbo->kmap);
 }
 
 u16
diff --git a/drivers/gpu/drm/nouveau/nouveau_channel.c b/drivers/gpu/drm/nouveau/nouveau_channel.c
index 0480f06..3144dde 100644
--- a/drivers/gpu/drm/nouveau/nouveau_channel.c
+++ b/drivers/gpu/drm/nouveau/nouveau_channel.c
@@ -310,6 +310,7 @@
 	/* Release the channel's resources */
 	nouveau_gpuobj_ref_del(dev, &chan->pushbuf);
 	if (chan->pushbuf_bo) {
+		nouveau_bo_unmap(chan->pushbuf_bo);
 		nouveau_bo_unpin(chan->pushbuf_bo);
 		nouveau_bo_ref(NULL, &chan->pushbuf_bo);
 	}
diff --git a/drivers/gpu/drm/nouveau/nv04_crtc.c b/drivers/gpu/drm/nouveau/nv04_crtc.c
index 932c914..1f0f978 100644
--- a/drivers/gpu/drm/nouveau/nv04_crtc.c
+++ b/drivers/gpu/drm/nouveau/nv04_crtc.c
@@ -718,6 +718,7 @@
 
 	drm_crtc_cleanup(crtc);
 
+	nouveau_bo_unmap(nv_crtc->cursor.nvbo);
 	nouveau_bo_ref(NULL, &nv_crtc->cursor.nvbo);
 	kfree(nv_crtc);
 }
diff --git a/drivers/gpu/drm/nouveau/nv50_crtc.c b/drivers/gpu/drm/nouveau/nv50_crtc.c
index bfd4ca2..d819eb9 100644
--- a/drivers/gpu/drm/nouveau/nv50_crtc.c
+++ b/drivers/gpu/drm/nouveau/nv50_crtc.c
@@ -338,7 +338,9 @@
 
 	nv50_cursor_fini(nv_crtc);
 
+	nouveau_bo_unmap(nv_crtc->lut.nvbo);
 	nouveau_bo_ref(NULL, &nv_crtc->lut.nvbo);
+	nouveau_bo_unmap(nv_crtc->cursor.nvbo);
 	nouveau_bo_ref(NULL, &nv_crtc->cursor.nvbo);
 	kfree(nv_crtc->mode);
 	kfree(nv_crtc);
diff --git a/drivers/gpu/drm/nouveau/nv50_display.c b/drivers/gpu/drm/nouveau/nv50_display.c
index 612fa6d..c87f874 100644
--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -42,6 +42,7 @@
 	*pchan = NULL;
 
 	nouveau_gpuobj_channel_takedown(chan);
+	nouveau_bo_unmap(chan->pushbuf_bo);
 	nouveau_bo_ref(NULL, &chan->pushbuf_bo);
 
 	if (chan->user)