[v2,6/6] drm/v3d: Invalidate the caches from the outside in.
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Message ID 20181203222438.25417-6-eric@anholt.net
State New
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Series
  • [v2,1/6] drm/v3d: Document cache flushing ABI.
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Commit Message

Eric Anholt Dec. 3, 2018, 10:24 p.m. UTC
This would be a fairly obscure race, but let's make sure we don't ever
lose it.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/v3d/v3d_gem.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Comments

Dave Emett Dec. 4, 2018, 12:01 p.m. UTC | #1
On Mon, 3 Dec 2018 at 22:24, Eric Anholt <eric@anholt.net> wrote:
>
> This would be a fairly obscure race, but let's make sure we don't ever
> lose it.
>
> Signed-off-by: Eric Anholt <eric@anholt.net>

Reviewed-by: Dave Emett <david.emett@broadcom.com>

> ---
>  drivers/gpu/drm/v3d/v3d_gem.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c
> index 8a4be9515179..443b1c53117a 100644
> --- a/drivers/gpu/drm/v3d/v3d_gem.c
> +++ b/drivers/gpu/drm/v3d/v3d_gem.c
> @@ -171,11 +171,15 @@ v3d_invalidate_slices(struct v3d_dev *v3d, int core)
>  void
>  v3d_invalidate_caches(struct v3d_dev *v3d)
>  {
> +       /* Invalidate the caches from the outside in.  That way if
> +        * another CL's concurrent use of nearby memory were to pull
> +        * an invalidated cacheline back in, we wouldn't leave stale
> +        * data in the inner cache.
> +        */
>         v3d_flush_l3(v3d);
> -
>         v3d_invalidate_l2c(v3d, 0);
> -       v3d_invalidate_slices(v3d, 0);
>         v3d_flush_l2t(v3d, 0);
> +       v3d_invalidate_slices(v3d, 0);
>  }
>
>  static void
> --
> 2.20.0.rc1
>

Patch
diff mbox series

diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c
index 8a4be9515179..443b1c53117a 100644
--- a/drivers/gpu/drm/v3d/v3d_gem.c
+++ b/drivers/gpu/drm/v3d/v3d_gem.c
@@ -171,11 +171,15 @@  v3d_invalidate_slices(struct v3d_dev *v3d, int core)
 void
 v3d_invalidate_caches(struct v3d_dev *v3d)
 {
+	/* Invalidate the caches from the outside in.  That way if
+	 * another CL's concurrent use of nearby memory were to pull
+	 * an invalidated cacheline back in, we wouldn't leave stale
+	 * data in the inner cache.
+	 */
 	v3d_flush_l3(v3d);
-
 	v3d_invalidate_l2c(v3d, 0);
-	v3d_invalidate_slices(v3d, 0);
 	v3d_flush_l2t(v3d, 0);
+	v3d_invalidate_slices(v3d, 0);
 }
 
 static void