drm/i915: Calculate pipe watermarks into CRTC state (v3)

A future patch will calculate these during the atomic 'check' phase
rather than at WM programming time, so let's store the watermark
values we're planning to use in the CRTC state; the values actually
active on the hardware remains in intel_crtc.

While we're at it, do some minor restructuring to keep ILK and SKL
values in a union.

v2: Don't move cxsr_allowed to state (Maarten)

v3: Only calculate watermarks in state.  Still keep active watermarks in
    intel_crtc itself.  (Ville)

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Smoke-tested-by: Paulo Zanoni <przanoni@gmail.com>
Link: http://patchwork.freedesktop.org/patch/59556/
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index fdfd4e2..9361df5 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -334,6 +334,21 @@
 /* drm_mode->private_flags */
 #define I915_MODE_FLAG_INHERITED 1
 
+struct intel_pipe_wm {
+	struct intel_wm_level wm[5];
+	uint32_t linetime;
+	bool fbc_wm_enabled;
+	bool pipe_enabled;
+	bool sprites_enabled;
+	bool sprites_scaled;
+};
+
+struct skl_pipe_wm {
+	struct skl_wm_level wm[8];
+	struct skl_wm_level trans_wm;
+	uint32_t linetime;
+};
+
 struct intel_crtc_state {
 	struct drm_crtc_state base;
 
@@ -471,6 +486,17 @@
 
 	/* IVB sprite scaling w/a (WaCxSRDisabledForSpriteScaling:ivb) */
 	bool disable_lp_wm;
+
+	struct {
+		/*
+		 * optimal watermarks, programmed post-vblank when this state
+		 * is committed
+		 */
+		union {
+			struct intel_pipe_wm ilk;
+			struct skl_pipe_wm skl;
+		} optimal;
+	} wm;
 };
 
 struct vlv_wm_state {
@@ -482,15 +508,6 @@
 	bool cxsr;
 };
 
-struct intel_pipe_wm {
-	struct intel_wm_level wm[5];
-	uint32_t linetime;
-	bool fbc_wm_enabled;
-	bool pipe_enabled;
-	bool sprites_enabled;
-	bool sprites_scaled;
-};
-
 struct intel_mmio_flip {
 	struct work_struct work;
 	struct drm_i915_private *i915;
@@ -499,12 +516,6 @@
 	unsigned int rotation;
 };
 
-struct skl_pipe_wm {
-	struct skl_wm_level wm[8];
-	struct skl_wm_level trans_wm;
-	uint32_t linetime;
-};
-
 /*
  * Tracking of operations that need to be performed at the beginning/end of an
  * atomic commit, outside the atomic section where interrupts are disabled.
@@ -571,9 +582,10 @@
 	/* per-pipe watermark state */
 	struct {
 		/* watermarks currently being used  */
-		struct intel_pipe_wm active;
-		/* SKL wm values currently in use */
-		struct skl_pipe_wm skl_active;
+		union {
+			struct intel_pipe_wm ilk;
+			struct skl_pipe_wm skl;
+		} active;
 		/* allow CxSR on this pipe */
 		bool cxsr_allowed;
 	} wm;