drm/msm/a6xx: Track current ctx by seqno

In theory a context can be destroyed and a new one allocated at the same
address, making the pointer comparision to detect when we don't need to
update the current pagetables invalid.  Instead assign a sequence number
to each context on creation, and use this for the check.

Fixes: 84c31ee16f90 ("drm/msm/a6xx: Add support for per-instance pagetables")
Signed-off-by: Rob Clark <robdclark@chromium.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 6176519d8bb0..4443d7b48618 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -682,6 +682,7 @@ static void load_gpu(struct drm_device *dev)
 
 static int context_init(struct drm_device *dev, struct drm_file *file)
 {
+	static atomic_t ident = ATOMIC_INIT(0);
 	struct msm_drm_private *priv = dev->dev_private;
 	struct msm_file_private *ctx;
 
@@ -698,6 +699,8 @@ static int context_init(struct drm_device *dev, struct drm_file *file)
 	ctx->aspace = msm_gpu_create_private_address_space(priv->gpu, current);
 	file->driver_priv = ctx;
 
+	ctx->seqno = atomic_inc_return(&ident);
+
 	return 0;
 }