drm/i915/guc: Fix for error capture after full GPU reset with GuC

In the case of a full GPU reset (e.g. because GuC has died or because
GuC's hang detection has been disabled), the driver can't rely on GuC
reporting the guilty context. Instead, the driver needs to scan all
active contexts and find one that is currently executing, as per the
execlist mode behaviour. In GuC mode, this scan is different to
execlist mode as the active request list is handled very differently.

Similarly, the request state dump in debugfs needs to be handled
differently when in GuC submission mode.

Also refactured some of the request scanning code to avoid duplication
across the multiple code paths that are now replicating it.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727002348.97202-20-matthew.brost@intel.com

1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index aeef45679897..28f38b02a5d2 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -2041,6 +2041,47 @@ void i915_request_show(struct drm_printer *m,
 		   name);
 }
 
+static bool engine_match_ring(struct intel_engine_cs *engine, struct i915_request *rq)
+{
+	u32 ring = ENGINE_READ(engine, RING_START);
+
+	return ring == i915_ggtt_offset(rq->ring->vma);
+}
+
+static bool match_ring(struct i915_request *rq)
+{
+	struct intel_engine_cs *engine;
+	bool found;
+	int i;
+
+	if (!intel_engine_is_virtual(rq->engine))
+		return engine_match_ring(rq->engine, rq);
+
+	found = false;
+	i = 0;
+	while ((engine = intel_engine_get_sibling(rq->engine, i++))) {
+		found = engine_match_ring(engine, rq);
+		if (found)
+			break;
+	}
+
+	return found;
+}
+
+enum i915_request_state i915_test_request_state(struct i915_request *rq)
+{
+	if (i915_request_completed(rq))
+		return I915_REQUEST_COMPLETE;
+
+	if (!i915_request_started(rq))
+		return I915_REQUEST_PENDING;
+
+	if (match_ring(rq))
+		return I915_REQUEST_ACTIVE;
+
+	return I915_REQUEST_QUEUED;
+}
+
 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
 #include "selftests/mock_request.c"
 #include "selftests/i915_request.c"