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[3/3] drm/msm: Stop using iommu_present()

Message ID 20220501101022.3931295-4-dmitry.baryshkov@linaro.org
State Accepted
Commit 8cb72adb1c6618c77fdf3e7c8acd8876d6d1b0b7
Headers show
Series drm/msm: fixes for KMS iommu handling | expand

Commit Message

Dmitry Baryshkov May 1, 2022, 10:10 a.m. UTC 
Even if some IOMMU has registered itself on the platform "bus", that
doesn't necessarily mean it provides translation for the device we
care about. Replace iommu_present() with a more appropriate check.

On Qualcomm platforms the IOMMU can be specified either for the MDP/DPU
device or for its parent MDSS device depending on the actual platform.
Check both of them, since that is how both DPU and MDP5 drivers work.

Co-developed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/msm/msm_drv.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 4a3dda23e3e0..a37a3bbc04d9 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -266,8 +266,14 @@  bool msm_use_mmu(struct drm_device *dev)
 {
 	struct msm_drm_private *priv = dev->dev_private;
 
-	/* a2xx comes with its own MMU */
-	return priv->is_a2xx || iommu_present(&platform_bus_type);
+	/*
+	 * a2xx comes with its own MMU
+	 * On other platforms IOMMU can be declared specified either for the
+	 * MDP/DPU device or for its parent, MDSS device.
+	 */
+	return priv->is_a2xx ||
+		device_iommu_mapped(dev->dev) ||
+		device_iommu_mapped(dev->dev->parent);
 }
 
 static int msm_init_vram(struct drm_device *dev)