drm/i915: Convert i915_gem_ring_throttle to use requests

Convert the throttle code to use the request structure rather than extracting a
ring/seqno pair from it and using those. This is in preparation for
__wait_seqno() becoming __wait_request().

For: VIZ-4377
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Thomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_gem.c

@@ -4098,10 +4098,8 @@ i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct drm_i915_file_private *file_priv = file->driver_priv;
 	unsigned long recent_enough = jiffies - msecs_to_jiffies(20);
-	struct drm_i915_gem_request *request;
-	struct intel_engine_cs *ring = NULL;
+	struct drm_i915_gem_request *request, *target = NULL;
 	unsigned reset_counter;
-	u32 seqno = 0;
 	int ret;
 
 	ret = i915_gem_wait_for_error(&dev_priv->gpu_error);
@@ -4117,16 +4115,17 @@ i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file)
 		if (time_after_eq(request->emitted_jiffies, recent_enough))
 			break;
 
-		ring = request->ring;
-		seqno = request->seqno;
+		target = request;
 	}
 	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
 	spin_unlock(&file_priv->mm.lock);
 
-	if (seqno == 0)
+	if (target == NULL)
 		return 0;
 
-	ret = __i915_wait_seqno(ring, seqno, reset_counter, true, NULL, NULL);
+	ret = __i915_wait_seqno(i915_gem_request_get_ring(target),
+				i915_gem_request_get_seqno(target),
+				reset_counter, true, NULL, NULL);
 	if (ret == 0)
 		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, 0);