Patch "drm/nouveau/mmu: flush tlbs before deleting page tables" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

drm/nouveau/mmu: flush tlbs before deleting page tables

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
drm-nouveau-mmu-flush-tlbs-before-deleting-page-tables.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Ben Skeggs <[email protected]>
Date: Mon, 25 Sep 2017 15:05:38 +1000
Subject: drm/nouveau/mmu: flush tlbs before deleting page tables

From: Ben Skeggs <[email protected]>

commit 77913bbcb43ac9a07a6fe849c2fd3bf85fc8bdd8 upstream.

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.

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

@@ -240,6 +240,8 @@ 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);
 	}
 }

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/drm-nouveau-mmu-flush-tlbs-before-deleting-page-tables.patch queue-4.4/drm-nouveau-bsp-g92-disable-by-default.patch