[Intel-gfx] [PATCH] drm/i915: Capture batchbuffer state upon GPU hang

[Chris Wilson]

The bbstate contains useful bits of debugging information such as
whether the batch is being read from GTT or PPGTT, or whether it is
allowed to execute privileged instructions.

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 | 2 ++
 drivers/gpu/drm/i915/i915_reg.h       | 1 +
 3 files changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3d65b511e320..ca1b223356eb 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -301,6 +301,7 @@ struct drm_i915_error_state {
 	u32 cpu_ring_tail[I915_NUM_RINGS];
 	u32 error; /* gen6+ */
 	u32 err_int; /* gen7 */
+	u32 bbstate[I915_NUM_RINGS];
 	u32 instpm[I915_NUM_RINGS];
 	u32 instps[I915_NUM_RINGS];
 	u32 extra_instdone[I915_NUM_INSTDONE_REG];
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 918d978dce4a..cdd9121a28bb 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -251,6 +251,7 @@ static void i915_ring_error_state(struct drm_i915_error_state_buf *m,
 	if (ring == RCS && INTEL_INFO(dev)->gen >= 4)
 		err_printf(m, "  BBADDR: 0x%08llx\n", error->bbaddr);
 
+	err_printf(m, "  BB_STATE: 0x%08x\n", error->bbstate[ring]);
 	if (INTEL_INFO(dev)->gen >= 4)
 		err_printf(m, "  INSTPS: 0x%08x\n", error->instps[ring]);
 	err_printf(m, "  INSTPM: 0x%08x\n", error->instpm[ring]);
@@ -735,6 +736,7 @@ static void i915_record_ring_state(struct drm_device *dev,
 	}
 
 	error->waiting[ring->id] = waitqueue_active(&ring->irq_queue);
+	error->bbstate[ring->id] = I915_READ(RING_BBSTATE(ring->mmio_base));
 	error->instpm[ring->id] = I915_READ(RING_INSTPM(ring->mmio_base));
 	error->seqno[ring->id] = ring->get_seqno(ring, false);
 	error->acthd[ring->id] = intel_ring_get_active_head(ring);
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index dbad19f4a983..9d79d28decb6 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -722,6 +722,7 @@
 #define NOPID		0x02094
 #define HWSTAM		0x02098
 #define DMA_FADD_I8XX	0x020d0
+#define RING_BBSTATE(base)	((base)+0x110)
 
 #define ERROR_GEN6	0x040a0
 #define GEN7_ERR_INT	0x44040
-- 
1.8.4.rc3