[PATCH 1/5] drm/msm: register a fault handler for display mmu faults

[Abhinav Kumar]

In preparation to register a iommu fault handler for display
related modules, register a fault handler for the backing
mmu object of msm_kms.

Currently, the fault handler only captures the display snapshot
but we can expand this later if more information needs to be
added to debug display mmu faults.

Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
---
 drivers/gpu/drm/msm/msm_kms.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_kms.c b/drivers/gpu/drm/msm/msm_kms.c
index af6a6fcb1173..2d7c5a5e22e0 100644
--- a/drivers/gpu/drm/msm/msm_kms.c
+++ b/drivers/gpu/drm/msm/msm_kms.c
@@ -164,12 +164,23 @@ void msm_crtc_disable_vblank(struct drm_crtc *crtc)
 	vblank_ctrl_queue_work(priv, crtc, false);
 }
 
+static int msm_kms_fault_handler(void *arg, unsigned long iova, int flags, void *data)
+{
+	struct msm_kms *kms = arg;
+
+	msm_disp_snapshot_state(kms->dev);
+
+	return -ENOSYS;
+}
+
 struct msm_gem_address_space *msm_kms_init_aspace(struct drm_device *dev)
 {
 	struct msm_gem_address_space *aspace;
 	struct msm_mmu *mmu;
 	struct device *mdp_dev = dev->dev;
 	struct device *mdss_dev = mdp_dev->parent;
+	struct msm_drm_private *priv = dev->dev_private;
+	struct msm_kms *kms = priv->kms;
 	struct device *iommu_dev;
 
 	/*
@@ -197,6 +208,8 @@ struct msm_gem_address_space *msm_kms_init_aspace(struct drm_device *dev)
 		mmu->funcs->destroy(mmu);
 	}
 
+	msm_mmu_set_fault_handler(aspace->mmu, kms, msm_kms_fault_handler);
+
 	return aspace;
 }
 
-- 
2.44.0