[PATCH 4/6] drm/i915/gt: Only invalidate TLBs exposed to user manipulation

[Mauro Carvalho Chehab]

From: Chris Wilson <chris.p.wilson@xxxxxxxxx>

Don't flush TLBs when the buffer is only used in the GGTT under full
control of the kernel, as there's no risk of of concurrent access
and stale access from prefetch.

We only need to invalidate the TLB if they are accessible by the user.

Fixes: 7938d61591d3 ("drm/i915: Flush TLBs before releasing backing store")

Signed-off-by: Chris Wilson <chris.p.wilson@xxxxxxxxx>
Cc: Fei Yang <fei.yang@xxxxxxxxx>
Cc: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
---

See [PATCH 0/6] at: https://lore.kernel.org/all/cover.1655306128.git.mchehab@xxxxxxxxxx/

 drivers/gpu/drm/i915/i915_vma.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 0bffb70b3c5f..7989986161e8 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -537,7 +537,8 @@ int i915_vma_bind(struct i915_vma *vma,
 				   bind_flags);
 	}
 
-	set_bit(I915_BO_WAS_BOUND_BIT, &vma->obj->flags);
+	if (bind_flags & I915_VMA_LOCAL_BIND)
+		set_bit(I915_BO_WAS_BOUND_BIT, &vma->obj->flags);
 
 	atomic_or(bind_flags, &vma->flags);
 	return 0;
-- 
2.36.1