drm/i915: Extract icl_set_pipe_chicken()

We need configure PIPE_CHICKEN during fastboot as well. Let's extract
it to a helper.

v2: Apparently PIPE_CHICKEN is icl+ only
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190204202139.26884-1-ville.syrjala@linux.intel.comReviewed-by: Matt Roper <matthew.d.roper@intel.com>

drivers/gpu/drm/i915/intel_display.c

@@ -3896,6 +3896,24 @@ void intel_finish_reset(struct drm_i915_private *dev_priv)
 	clear_bit(I915_RESET_MODESET, &dev_priv->gpu_error.flags);
 }
 
+static void icl_set_pipe_chicken(struct intel_crtc *crtc)
+{
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	enum pipe pipe = crtc->pipe;
+	u32 tmp;
+
+	tmp = I915_READ(PIPE_CHICKEN(pipe));
+
+	/*
+	 * Display WA #1153: icl
+	 * enable hardware to bypass the alpha math
+	 * and rounding for per-pixel values 00 and 0xff
+	 */
+	tmp |= PER_PIXEL_ALPHA_BYPASS_EN;
+
+	I915_WRITE(PIPE_CHICKEN(pipe), tmp);
+}
+
 static void intel_update_pipe_config(const struct intel_crtc_state *old_crtc_state,
 				     const struct intel_crtc_state *new_crtc_state)
 {
@@ -5782,7 +5800,6 @@ static void haswell_crtc_enable(struct intel_crtc_state *pipe_config,
 	struct intel_atomic_state *old_intel_state =
 		to_intel_atomic_state(old_state);
 	bool psl_clkgate_wa;
-	u32 pipe_chicken;
 
 	if (WARN_ON(intel_crtc->active))
 		return;
@@ -5839,16 +5856,8 @@ static void haswell_crtc_enable(struct intel_crtc_state *pipe_config,
 	 */
 	intel_color_load_luts(pipe_config);
 
-	/*
-	 * Display WA #1153: enable hardware to bypass the alpha math
-	 * and rounding for per-pixel values 00 and 0xff
-	 */
-	if (INTEL_GEN(dev_priv) >= 11) {
-		pipe_chicken = I915_READ(PIPE_CHICKEN(pipe));
-		if (!(pipe_chicken & PER_PIXEL_ALPHA_BYPASS_EN))
-			I915_WRITE_FW(PIPE_CHICKEN(pipe),
-				      pipe_chicken | PER_PIXEL_ALPHA_BYPASS_EN);
-	}
+	if (INTEL_GEN(dev_priv) >= 11)
+		icl_set_pipe_chicken(intel_crtc);
 
 	intel_ddi_set_pipe_settings(pipe_config);
 	if (!transcoder_is_dsi(cpu_transcoder))