drm/i915/skl: Read the pipe WM HW state

This patch provides the implementation for reading the pipe wm HW
state.

v2: Incorporated Damien's review comments and also made modifications
    to incorporate the plane/cursor split.

v3: No need to ident a line that was fitting 80 chars
    Return early instead of indenting the remaining of a function
    (Damien)

v4: Rebase on top of nightly (minor conflict in intel_drv.h)
v5: Rebase on top of nightly (minor conflict in intel_drv.h)
v6: Rebase on top of nightly (minor conflict in intel_drv.h)

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Pradeep Bhat <pradeep.bhat@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -13266,7 +13266,9 @@ void intel_modeset_setup_hw_state(struct drm_device *dev,
 		pll->on = false;
 	}
 
-	if (HAS_PCH_SPLIT(dev))
+	if (IS_GEN9(dev))
+		skl_wm_get_hw_state(dev);
+	else if (HAS_PCH_SPLIT(dev))
 		ilk_wm_get_hw_state(dev);
 
 	if (force_restore) {

drivers/gpu/drm/i915/intel_drv.h

@@ -1164,6 +1164,7 @@ void gen6_update_ring_freq(struct drm_device *dev);
 void gen6_rps_idle(struct drm_i915_private *dev_priv);
 void gen6_rps_boost(struct drm_i915_private *dev_priv);
 void ilk_wm_get_hw_state(struct drm_device *dev);
+void skl_wm_get_hw_state(struct drm_device *dev);
 
 
 /* intel_sdvo.c */

drivers/gpu/drm/i915/intel_pm.c

@@ -3624,6 +3624,110 @@ ilk_update_sprite_wm(struct drm_plane *plane,
 	ilk_update_wm(crtc);
 }
 
+static void skl_pipe_wm_active_state(uint32_t val,
+				     struct skl_pipe_wm *active,
+				     bool is_transwm,
+				     bool is_cursor,
+				     int i,
+				     int level)
+{
+	bool is_enabled = (val & PLANE_WM_EN) != 0;
+
+	if (!is_transwm) {
+		if (!is_cursor) {
+			active->wm[level].plane_en[i] = is_enabled;
+			active->wm[level].plane_res_b[i] =
+					val & PLANE_WM_BLOCKS_MASK;
+			active->wm[level].plane_res_l[i] =
+					(val >> PLANE_WM_LINES_SHIFT) &
+						PLANE_WM_LINES_MASK;
+		} else {
+			active->wm[level].cursor_en = is_enabled;
+			active->wm[level].cursor_res_b =
+					val & PLANE_WM_BLOCKS_MASK;
+			active->wm[level].cursor_res_l =
+					(val >> PLANE_WM_LINES_SHIFT) &
+						PLANE_WM_LINES_MASK;
+		}
+	} else {
+		if (!is_cursor) {
+			active->trans_wm.plane_en[i] = is_enabled;
+			active->trans_wm.plane_res_b[i] =
+					val & PLANE_WM_BLOCKS_MASK;
+			active->trans_wm.plane_res_l[i] =
+					(val >> PLANE_WM_LINES_SHIFT) &
+						PLANE_WM_LINES_MASK;
+		} else {
+			active->trans_wm.cursor_en = is_enabled;
+			active->trans_wm.cursor_res_b =
+					val & PLANE_WM_BLOCKS_MASK;
+			active->trans_wm.cursor_res_l =
+					(val >> PLANE_WM_LINES_SHIFT) &
+						PLANE_WM_LINES_MASK;
+		}
+	}
+}
+
+static void skl_pipe_wm_get_hw_state(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct skl_wm_values *hw = &dev_priv->wm.skl_hw;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	struct skl_pipe_wm *active = &intel_crtc->wm.skl_active;
+	enum pipe pipe = intel_crtc->pipe;
+	int level, i, max_level;
+	uint32_t temp;
+
+	max_level = ilk_wm_max_level(dev);
+
+	hw->wm_linetime[pipe] = I915_READ(PIPE_WM_LINETIME(pipe));
+
+	for (level = 0; level <= max_level; level++) {
+		for (i = 0; i < intel_num_planes(intel_crtc); i++)
+			hw->plane[pipe][i][level] =
+					I915_READ(PLANE_WM(pipe, i, level));
+		hw->cursor[pipe][level] = I915_READ(CUR_WM(pipe, level));
+	}
+
+	for (i = 0; i < intel_num_planes(intel_crtc); i++)
+		hw->plane_trans[pipe][i] = I915_READ(PLANE_WM_TRANS(pipe, i));
+	hw->cursor_trans[pipe] = I915_READ(CUR_WM_TRANS(pipe));
+
+	if (!intel_crtc_active(crtc))
+		return;
+
+	hw->dirty[pipe] = true;
+
+	active->linetime = hw->wm_linetime[pipe];
+
+	for (level = 0; level <= max_level; level++) {
+		for (i = 0; i < intel_num_planes(intel_crtc); i++) {
+			temp = hw->plane[pipe][i][level];
+			skl_pipe_wm_active_state(temp, active, false,
+						false, i, level);
+		}
+		temp = hw->cursor[pipe][level];
+		skl_pipe_wm_active_state(temp, active, false, true, i, level);
+	}
+
+	for (i = 0; i < intel_num_planes(intel_crtc); i++) {
+		temp = hw->plane_trans[pipe][i];
+		skl_pipe_wm_active_state(temp, active, true, false, i, 0);
+	}
+
+	temp = hw->cursor_trans[pipe];
+	skl_pipe_wm_active_state(temp, active, true, true, i, 0);
+}
+
+void skl_wm_get_hw_state(struct drm_device *dev)
+{
+	struct drm_crtc *crtc;
+
+	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
+		skl_pipe_wm_get_hw_state(crtc);
+}
+
 static void ilk_pipe_wm_get_hw_state(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;