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

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

[gregkh]

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 <stable@vger.kernel.org> know about it.


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

From: Ben Skeggs <bskeggs@redhat.com>

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.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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
@@ -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 bskeggs@redhat.com 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