drm/i915: Add IVB DDB partitioning control

On IVB the display data buffer partitioning control lives in the
DISP_ARB_CTL2 register. Add the relevant defines/code for it.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -4148,6 +4148,8 @@
 #define DISP_ARB_CTL	0x45000
 #define  DISP_TILE_SURFACE_SWIZZLING	(1<<13)
 #define  DISP_FBC_WM_DIS		(1<<15)
+#define DISP_ARB_CTL2	0x45004
+#define  DISP_DATA_PARTITION_5_6	(1<<6)
 #define GEN7_MSG_CTL	0x45010
 #define  WAIT_FOR_PCH_RESET_ACK		(1<<1)
 #define  WAIT_FOR_PCH_FLR_ACK		(1<<0)

drivers/gpu/drm/i915/intel_pm.c

@@ -2864,6 +2864,7 @@ static unsigned int ilk_compute_wm_dirty(struct drm_device *dev,
 static void hsw_write_wm_values(struct drm_i915_private *dev_priv,
 				struct hsw_wm_values *results)
 {
+	struct drm_device *dev = dev_priv->dev;
 	struct hsw_wm_values *previous = &dev_priv->wm.hw;
 	unsigned int dirty;
 	uint32_t val;
@@ -2894,12 +2895,21 @@ static void hsw_write_wm_values(struct drm_i915_private *dev_priv,
 		I915_WRITE(PIPE_WM_LINETIME(PIPE_C), results->wm_linetime[2]);
 
 	if (dirty & WM_DIRTY_DDB) {
+		if (IS_HASWELL(dev)) {
 			val = I915_READ(WM_MISC);
 			if (results->partitioning == INTEL_DDB_PART_1_2)
 				val &= ~WM_MISC_DATA_PARTITION_5_6;
 			else
 				val |= WM_MISC_DATA_PARTITION_5_6;
 			I915_WRITE(WM_MISC, val);
+		} else {
+			val = I915_READ(DISP_ARB_CTL2);
+			if (results->partitioning == INTEL_DDB_PART_1_2)
+				val &= ~DISP_DATA_PARTITION_5_6;
+			else
+				val |= DISP_DATA_PARTITION_5_6;
+			I915_WRITE(DISP_ARB_CTL2, val);
+		}
 	}
 
 	if (dirty & WM_DIRTY_FBC) {
@@ -3210,8 +3220,12 @@ void ilk_wm_get_hw_state(struct drm_device *dev)
 	hw->wm_lp_spr[1] = I915_READ(WM2S_LP_IVB);
 	hw->wm_lp_spr[2] = I915_READ(WM3S_LP_IVB);
 
+	if (IS_HASWELL(dev))
 		hw->partitioning = (I915_READ(WM_MISC) & WM_MISC_DATA_PARTITION_5_6) ?
 			INTEL_DDB_PART_5_6 : INTEL_DDB_PART_1_2;
+	else if (IS_IVYBRIDGE(dev))
+		hw->partitioning = (I915_READ(DISP_ARB_CTL2) & DISP_DATA_PARTITION_5_6) ?
+			INTEL_DDB_PART_5_6 : INTEL_DDB_PART_1_2;
 
 	hw->enable_fbc_wm =
 		!(I915_READ(DISP_ARB_CTL) & DISP_FBC_WM_DIS);