diff --git a/drivers/gpu/drm/nouveau/core/subdev/instmem/nv50.c b/drivers/gpu/drm/nouveau/core/subdev/instmem/nv50.c
index cfc7e31..a68bc1d 100644
--- a/drivers/gpu/drm/nouveau/core/subdev/instmem/nv50.c
+++ b/drivers/gpu/drm/nouveau/core/subdev/instmem/nv50.c
@@ -81,8 +81,8 @@ nv50_instobj_rd32(struct nouveau_object *object, u64 offset)
 	struct nv50_instmem_priv *priv = (void *)object->engine;
 	struct nv50_instobj_priv *node = (void *)object;
 	unsigned long flags;
-	u64 base = (node->mem->offset + offset) & 0xffffff00000ULL;
-	u64 addr = (node->mem->offset + offset) & 0x000000fffffULL;
+	u64 base = (node->mem->offset + offset) & 0xfffffff0000ULL;
+	u64 addr = (node->mem->offset + offset) & 0x0000000ffffULL;
 	u32 data;
 
 	spin_lock_irqsave(&priv->lock, flags);
@@ -101,8 +101,8 @@ nv50_instobj_wr32(struct nouveau_object *object, u64 offset, u32 data)
 	struct nv50_instmem_priv *priv = (void *)object->engine;
 	struct nv50_instobj_priv *node = (void *)object;
 	unsigned long flags;
-	u64 base = (node->mem->offset + offset) & 0xffffff00000ULL;
-	u64 addr = (node->mem->offset + offset) & 0x000000fffffULL;
+	u64 base = (node->mem->offset + offset) & 0xfffffff0000ULL;
+	u64 addr = (node->mem->offset + offset) & 0x0000000ffffULL;
 
 	spin_lock_irqsave(&priv->lock, flags);
 	if (unlikely(priv->addr != base)) {