[PATCH 5.4 129/132] drm/msm/gpu: make ringbuffer readonly

Greg Kroah-Hartman
2020-09-15T14:52:03Z

From: Rob Clark <robdclark@chromium.org>

[ Upstream commit 352c83fb39cae3eff95a8e1ed23006291abb6196 ]

The GPU has no business writing into the ringbuffer, let's make it
readonly to the GPU.

Fixes: 7198e6b03155 ("drm/msm: add a3xx gpu support")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/msm/msm_ringbuffer.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.c b/drivers/gpu/drm/msm/msm_ringbuffer.c
index e397c44cc0112..39ecb5a18431e 100644
--- a/drivers/gpu/drm/msm/msm_ringbuffer.c
+++ b/drivers/gpu/drm/msm/msm_ringbuffer.c
@@ -27,7 +27,8 @@ struct msm_ringbuffer *msm_ringbuffer_new(struct msm_gpu *gpu, int id,
ring->id = id;

ring->start = msm_gem_kernel_new(gpu->dev, MSM_GPU_RINGBUFFER_SZ,
- MSM_BO_WC, gpu->aspace, &ring->bo, &ring->iova);
+ MSM_BO_WC | MSM_BO_GPU_READONLY, gpu->aspace, &ring->bo,
+ &ring->iova);

if (IS_ERR(ring->start)) {
ret = PTR_ERR(ring->start);
--
2.25.1