drm/i915/gen9: Allow calculation of data rate for in-flight state (v2)

Our skl_get_total_relative_data_rate() function gets passed a crtc state
object to calculate the data rate for, but it currently always looks
up the committed plane states that correspond to that CRTC.  Let's
check whether the CRTC state is an in-flight state (meaning
cstate->state is non-NULL) and if so, use the corresponding in-flight
plane states.

We'll soon be using this function exclusively for in-flight states; at
that time we'll be able to simplify the function a bit, but for now we
allow it to be used in either mode.

v2:
 - Rebase on top of changes to cache plane data rates.
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463061971-19638-5-git-send-email-matthew.d.roper@intel.com

drivers/gpu/drm/i915/intel_pm.c

@@ -2975,25 +2975,69 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
  *   3 * 4096 * 8192  * 4 < 2^32
  */
 static unsigned int
-skl_get_total_relative_data_rate(struct intel_crtc_state *cstate)
+skl_get_total_relative_data_rate(struct intel_crtc_state *intel_cstate)
 {
-	struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);
-	struct drm_device *dev = intel_crtc->base.dev;
+	struct drm_crtc_state *cstate = &intel_cstate->base;
+	struct drm_atomic_state *state = cstate->state;
+	struct drm_crtc *crtc = cstate->crtc;
+	struct drm_device *dev = crtc->dev;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	const struct intel_plane *intel_plane;
 	unsigned int rate, total_data_rate = 0;
+	int id;
 
 	/* Calculate and cache data rate for each plane */
+	/*
+	 * FIXME: At the moment this function can be called on either an
+	 * in-flight or a committed state object.  If it's in-flight then we
+	 * only want to re-calculate the plane data rate for planes that are
+	 * part of the transaction (i.e., we don't want to grab any additional
+	 * plane states if we don't have to).  If we're operating on committed
+	 * state, we'll just go ahead and recalculate the plane data rate for
+	 * all planes.
+	 *
+	 * Once we finish moving our DDB allocation to the atomic check phase,
+	 * we'll only be calling this function on in-flight state objects, so
+	 * the 'else' branch here will go away.
+	 */
+	if (state) {
+		struct drm_plane *plane;
+		struct drm_plane_state *pstate;
+		int i;
+
+		for_each_plane_in_state(state, plane, pstate, i) {
+			intel_plane = to_intel_plane(plane);
+			id = skl_wm_plane_id(intel_plane);
+
+			if (intel_plane->pipe != intel_crtc->pipe)
+				continue;
+
+			/* packed/uv */
+			rate = skl_plane_relative_data_rate(intel_cstate,
+							    pstate, 0);
+			intel_cstate->wm.skl.plane_data_rate[id] = rate;
+
+			/* y-plane */
+			rate = skl_plane_relative_data_rate(intel_cstate,
+							    pstate, 1);
+			intel_cstate->wm.skl.plane_y_data_rate[id] = rate;
+		}
+	} else {
 		for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
-		const struct drm_plane_state *pstate = intel_plane->base.state;
+			const struct drm_plane_state *pstate =
+				intel_plane->base.state;
 			int id = skl_wm_plane_id(intel_plane);
 
 			/* packed/uv */
-		rate = skl_plane_relative_data_rate(cstate, pstate, 0);
-		cstate->wm.skl.plane_data_rate[id] = rate;
+			rate = skl_plane_relative_data_rate(intel_cstate,
+							    pstate, 0);
+			intel_cstate->wm.skl.plane_data_rate[id] = rate;
 
 			/* y-plane */
-		rate = skl_plane_relative_data_rate(cstate, pstate, 1);
-		cstate->wm.skl.plane_y_data_rate[id] = rate;
+			rate = skl_plane_relative_data_rate(intel_cstate,
+							    pstate, 1);
+			intel_cstate->wm.skl.plane_y_data_rate[id] = rate;
+		}
 	}
 
 	/* Calculate CRTC's total data rate from cached values */
@@ -3001,10 +3045,12 @@ skl_get_total_relative_data_rate(struct intel_crtc_state *cstate)
 		int id = skl_wm_plane_id(intel_plane);
 
 		/* packed/uv */
-		total_data_rate += cstate->wm.skl.plane_data_rate[id];
-		total_data_rate += cstate->wm.skl.plane_y_data_rate[id];
+		total_data_rate += intel_cstate->wm.skl.plane_data_rate[id];
+		total_data_rate += intel_cstate->wm.skl.plane_y_data_rate[id];
 	}
 
+	WARN_ON(cstate->plane_mask && total_data_rate == 0);
+
 	return total_data_rate;
 }