From 77913bbcb43ac9a07a6fe849c2fd3bf85fc8bdd8 Mon Sep 17 00:00:00 2001
From: Ben Skeggs <bskeggs@redhat.com>
Date: Mon, 25 Sep 2017 15:05:38 +1000
Subject: [PATCH] drm/nouveau/mmu: flush tlbs before deleting page tables
Git-commit: 77913bbcb43ac9a07a6fe849c2fd3bf85fc8bdd8
Patch-mainline: v4.14-rc6
References: bsc#1051510

Even though we've zeroed the PDE, the GPU may have cached the PD, so we
need to flush when deleting them.

Noticed while working on replacement MMU code, but a backport might be a
good idea, so let's fix it in the current code too.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Cc: stable@vger.kernel.org
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c
@@ -241,6 +241,8 @@ nvkm_vm_unmap_pgt(struct nvkm_vm *vm, in
 			mmu->func->map_pgt(vpgd->obj, pde, vpgt->mem);
 		}
 
+		mmu->func->flush(vm);
+
 		nvkm_memory_del(&pgt);
 	}
 }