drm/i915: Nuke crtc->plane

Eliminate crtc->plane since it's pretty much a layering violation.
We can always get the plane via crtc->primary if we actually need it.

The only ugly thing left is plane_to_crtc_mapping[], but that's
still needed by the pre-g4x watermark code.

v2: Removed a misplaced comment change (Daniel)
v3: Rebase due to fbc crtc->y usage removal
v4: s/plane/i9xx_plane/ etc. (James)

Cc: James Ausmus <james.ausmus@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20171117191917.11506-9-ville.syrjala@linux.intel.com
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

drivers/gpu/drm/i915/intel_display.c

@@ -13463,14 +13463,13 @@ static int intel_crtc_init(struct drm_i915_private *dev_priv, enum pipe pipe)
 		goto fail;
 
 	intel_crtc->pipe = pipe;
-	intel_crtc->i9xx_plane = primary->i9xx_plane;
 
 	/* initialize shared scalers */
 	intel_crtc_init_scalers(intel_crtc, crtc_state);
 
 	BUG_ON(pipe >= ARRAY_SIZE(dev_priv->plane_to_crtc_mapping) ||
-	       dev_priv->plane_to_crtc_mapping[intel_crtc->i9xx_plane] != NULL);
-	dev_priv->plane_to_crtc_mapping[intel_crtc->i9xx_plane] = intel_crtc;
+	       dev_priv->plane_to_crtc_mapping[primary->i9xx_plane] != NULL);
+	dev_priv->plane_to_crtc_mapping[primary->i9xx_plane] = intel_crtc;
 	dev_priv->pipe_to_crtc_mapping[intel_crtc->pipe] = intel_crtc;
 
 	drm_crtc_helper_add(&intel_crtc->base, &intel_helper_funcs);

drivers/gpu/drm/i915/intel_drv.h

@@ -799,7 +799,6 @@ struct intel_crtc_state {
 struct intel_crtc {
 	struct drm_crtc base;
 	enum pipe pipe;
-	enum i9xx_plane_id i9xx_plane;
 	/*
 	 * Whether the crtc and the connected output pipeline is active. Implies
 	 * that crtc->enabled is set, i.e. the current mode configuration has

drivers/gpu/drm/i915/intel_fbc.c

@@ -890,7 +890,7 @@ static void intel_fbc_get_reg_params(struct intel_crtc *crtc,
 	params->vma = cache->vma;
 
 	params->crtc.pipe = crtc->pipe;
-	params->crtc.i9xx_plane = crtc->i9xx_plane;
+	params->crtc.i9xx_plane = to_intel_plane(crtc->base.primary)->i9xx_plane;
 	params->crtc.fence_y_offset = get_crtc_fence_y_offset(fbc);
 
 	params->fb.format = cache->fb.format;
@@ -1086,7 +1086,7 @@ void intel_fbc_choose_crtc(struct drm_i915_private *dev_priv,
 		if (fbc_on_pipe_a_only(dev_priv) && crtc->pipe != PIPE_A)
 			continue;
 
-		if (fbc_on_plane_a_only(dev_priv) && crtc->i9xx_plane != PLANE_A)
+		if (fbc_on_plane_a_only(dev_priv) && plane->i9xx_plane != PLANE_A)
 			continue;
 
 		crtc_state = intel_atomic_get_new_crtc_state(state, crtc);