drm/i915: Convert 'trace_irq' to use requests rather than seqnos

Updated the trace_irq code to use requests instead of seqnos. This includes
reference counting the request object to ensure it sticks around when required.
Note that getting access to the reference counting functions means moving the
inline i915_trace_irq_get() function from intel_ringbuffer.h to i915_drv.h.

For: VIZ-4377
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Thomas Daniel <Thomas.Daniel@intel.com>
[danvet: Resolve conflict due to shuffled merge order.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -3132,4 +3132,11 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 	}
 }
 
+static inline void i915_trace_irq_get(struct intel_engine_cs *ring,
+				      struct drm_i915_gem_request *req)
+{
+	if (ring->trace_irq_req == NULL && ring->irq_get(ring))
+		i915_gem_request_assign(&ring->trace_irq_req, req);
+}
+
 #endif

drivers/gpu/drm/i915/i915_gem.c

@@ -2786,11 +2786,10 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
 		i915_gem_free_request(request);
 	}
 
-	if (unlikely(ring->trace_irq_seqno &&
-		     i915_seqno_passed(ring->get_seqno(ring, true),
-				       ring->trace_irq_seqno))) {
+	if (unlikely(ring->trace_irq_req &&
+		     i915_gem_request_completed(ring->trace_irq_req, true))) {
 		ring->irq_put(ring);
-		ring->trace_irq_seqno = 0;
+		i915_gem_request_assign(&ring->trace_irq_req, NULL);
 	}
 
 	WARN_ON(i915_verify_lists(ring->dev));

drivers/gpu/drm/i915/i915_trace.h

@@ -369,7 +369,7 @@ TRACE_EVENT(i915_gem_ring_dispatch,
 			   __entry->ring = ring->id;
 			   __entry->seqno = i915_gem_request_get_seqno(req);
 			   __entry->flags = flags;
-			   i915_trace_irq_get(ring, __entry->seqno);
+			   i915_trace_irq_get(ring, req);
 			   ),
 
 	    TP_printk("dev=%u, ring=%u, seqno=%u, flags=%x",

drivers/gpu/drm/i915/intel_ringbuffer.h

@@ -142,7 +142,7 @@ struct  intel_engine_cs {
 
 	unsigned irq_refcount; /* protected by dev_priv->irq_lock */
 	u32		irq_enable_mask;	/* bitmask to enable ring interrupt */
-	u32		trace_irq_seqno;
+	struct drm_i915_gem_request *trace_irq_req;
 	bool __must_check (*irq_get)(struct intel_engine_cs *ring);
 	void		(*irq_put)(struct intel_engine_cs *ring);
 
@@ -442,10 +442,4 @@ intel_ring_get_request(struct intel_engine_cs *ring)
 	return ring->outstanding_lazy_request;
 }
 
-static inline void i915_trace_irq_get(struct intel_engine_cs *ring, u32 seqno)
-{
-	if (ring->trace_irq_seqno == 0 && ring->irq_get(ring))
-		ring->trace_irq_seqno = seqno;
-}
-
 #endif /* _INTEL_RINGBUFFER_H_ */