[Intel-gfx] [PATCH] drm/i915: Report IOMMU enabled status for GPU hangs

[Chris Wilson]

The IOMMU for Intel graphics has historically had many issues resulting
in random GPU hangs. Lets include its status when capturing the GPU hang
error state for post-mortem analysis.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_drv.h       | 1 +
 drivers/gpu/drm/i915/i915_gpu_error.c | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 786ddd8b4e97..82d225786db2 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -488,6 +488,7 @@ struct drm_i915_error_state {
 	struct timeval time;
 
 	char error_msg[128];
+	int iommu;
 	u32 reset_count;
 	u32 suspend_count;
 
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 0110c2626859..21ae99e5b1ed 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -399,6 +399,7 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
 	err_printf(m, "Reset count: %u\n", error->reset_count);
 	err_printf(m, "Suspend count: %u\n", error->suspend_count);
 	err_printf(m, "PCI ID: 0x%04x\n", dev->pdev->device);
+	err_printf(m, "IOMMU enabled?: %d\n", error->iommu);
 	err_printf(m, "EIR: 0x%08x\n", error->eir);
 	err_printf(m, "IER: 0x%08x\n", error->ier);
 	if (INTEL_INFO(dev)->gen >= 8) {
@@ -1341,6 +1342,10 @@ static void i915_error_capture_msg(struct drm_device *dev,
 static void i915_capture_gen_state(struct drm_i915_private *dev_priv,
 				   struct drm_i915_error_state *error)
 {
+	error->iommu = -1;
+#ifdef CONFIG_INTEL_IOMMU
+	error->iommu = intel_iommu_gfx_mapped;
+#endif
 	error->reset_count = i915_reset_count(&dev_priv->gpu_error);
 	error->suspend_count = dev_priv->suspend_count;
 }
-- 
2.5.0