drm/i915/skl+: Optimize WM calculation

Plane configuration parameters doesn't change for each WM-level
calculation. Currently we compute same parameters 8 times for each
wm-level.
This patch optimizes it by calculating these parameters in beginning
& reuse during each level-wm calculation.

Changes since V1:
 - rebase on top of Rodrigo's series for CNL
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170817134529.2839-3-mahesh1.kumar@intel.com

drivers/gpu/drm/i915/i915_drv.h

@@ -1837,6 +1837,20 @@ struct skl_wm_level {
 	uint8_t plane_res_l;
 };
 
+/* Stores plane specific WM parameters */
+struct skl_wm_params {
+	bool x_tiled, y_tiled;
+	bool rc_surface;
+	uint32_t width;
+	uint8_t cpp;
+	uint32_t plane_pixel_rate;
+	uint32_t y_min_scanlines;
+	uint32_t plane_bytes_per_line;
+	uint_fixed_16_16_t plane_blocks_per_line;
+	uint_fixed_16_16_t y_tile_minimum;
+	uint32_t linetime_us;
+};
+
 /*
  * This struct helps tracking the state needed for runtime PM, which puts the
  * device in PCI D3 state. Notice that when this happens, nothing on the

drivers/gpu/drm/i915/intel_pm.c

@@ -4376,134 +4376,146 @@ skl_adjusted_plane_pixel_rate(const struct intel_crtc_state *cstate,
 					    downscale_amount);
 }
 
-static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
-				struct intel_crtc_state *cstate,
-				const struct intel_plane_state *intel_pstate,
-				uint16_t ddb_allocation,
-				int level,
-				uint16_t *out_blocks, /* out */
-				uint8_t *out_lines, /* out */
-				bool *enabled /* out */)
+static int
+skl_compute_plane_wm_params(const struct drm_i915_private *dev_priv,
+			    struct intel_crtc_state *cstate,
+			    const struct intel_plane_state *intel_pstate,
+			    struct skl_wm_params *wp)
 {
 	struct intel_plane *plane = to_intel_plane(intel_pstate->base.plane);
 	const struct drm_plane_state *pstate = &intel_pstate->base;
 	const struct drm_framebuffer *fb = pstate->fb;
-	uint32_t latency = dev_priv->wm.skl_latency[level];
-	uint_fixed_16_16_t method1, method2;
-	uint_fixed_16_16_t plane_blocks_per_line;
-	uint_fixed_16_16_t selected_result;
 	uint32_t interm_pbpl;
-	uint32_t plane_bytes_per_line;
-	uint32_t res_blocks, res_lines;
-	uint8_t cpp;
-	uint32_t width = 0;
-	uint32_t plane_pixel_rate;
-	uint_fixed_16_16_t y_tile_minimum;
-	uint32_t y_min_scanlines;
 	struct intel_atomic_state *state =
 		to_intel_atomic_state(cstate->base.state);
 	bool apply_memory_bw_wa = skl_needs_memory_bw_wa(state);
-	bool y_tiled, x_tiled;
 
-	if (latency == 0 ||
-	    !intel_wm_plane_visible(cstate, intel_pstate)) {
-		*enabled = false;
+	if (!intel_wm_plane_visible(cstate, intel_pstate))
 		return 0;
-	}
 
-	y_tiled = fb->modifier == I915_FORMAT_MOD_Y_TILED ||
-		  fb->modifier == I915_FORMAT_MOD_Yf_TILED ||
-		  fb->modifier == I915_FORMAT_MOD_Y_TILED_CCS ||
-		  fb->modifier == I915_FORMAT_MOD_Yf_TILED_CCS;
-	x_tiled = fb->modifier == I915_FORMAT_MOD_X_TILED;
-
-	/* Display WA #1141: kbl,cfl */
-	if ((IS_KABYLAKE(dev_priv) || IS_COFFEELAKE(dev_priv)) &&
-	    dev_priv->ipc_enabled)
-		latency += 4;
-
-	if (apply_memory_bw_wa && x_tiled)
-		latency += 15;
+	wp->y_tiled = fb->modifier == I915_FORMAT_MOD_Y_TILED ||
+		      fb->modifier == I915_FORMAT_MOD_Yf_TILED ||
+		      fb->modifier == I915_FORMAT_MOD_Y_TILED_CCS ||
+		      fb->modifier == I915_FORMAT_MOD_Yf_TILED_CCS;
+	wp->x_tiled = fb->modifier == I915_FORMAT_MOD_X_TILED;
+	wp->rc_surface = fb->modifier == I915_FORMAT_MOD_Y_TILED_CCS ||
+			 fb->modifier == I915_FORMAT_MOD_Yf_TILED_CCS;
 
 	if (plane->id == PLANE_CURSOR) {
-		width = intel_pstate->base.crtc_w;
+		wp->width = intel_pstate->base.crtc_w;
 	} else {
 		/*
 		 * Src coordinates are already rotated by 270 degrees for
 		 * the 90/270 degree plane rotation cases (to match the
 		 * GTT mapping), hence no need to account for rotation here.
 		 */
-		width = drm_rect_width(&intel_pstate->base.src) >> 16;
+		wp->width = drm_rect_width(&intel_pstate->base.src) >> 16;
 	}
 
-	cpp = (fb->format->format == DRM_FORMAT_NV12) ? fb->format->cpp[1] :
-							fb->format->cpp[0];
-	plane_pixel_rate = skl_adjusted_plane_pixel_rate(cstate, intel_pstate);
+	wp->cpp = (fb->format->format == DRM_FORMAT_NV12) ? fb->format->cpp[1] :
+							    fb->format->cpp[0];
+	wp->plane_pixel_rate = skl_adjusted_plane_pixel_rate(cstate,
+							     intel_pstate);
 
 	if (drm_rotation_90_or_270(pstate->rotation)) {
 
-		switch (cpp) {
+		switch (wp->cpp) {
 		case 1:
-			y_min_scanlines = 16;
+			wp->y_min_scanlines = 16;
 			break;
 		case 2:
-			y_min_scanlines = 8;
+			wp->y_min_scanlines = 8;
 			break;
 		case 4:
-			y_min_scanlines = 4;
+			wp->y_min_scanlines = 4;
 			break;
 		default:
-			MISSING_CASE(cpp);
+			MISSING_CASE(wp->cpp);
 			return -EINVAL;
 		}
 	} else {
-		y_min_scanlines = 4;
+		wp->y_min_scanlines = 4;
 	}
 
 	if (apply_memory_bw_wa)
-		y_min_scanlines *= 2;
+		wp->y_min_scanlines *= 2;
 
-	plane_bytes_per_line = width * cpp;
-	if (y_tiled) {
-		interm_pbpl = DIV_ROUND_UP(plane_bytes_per_line *
-					   y_min_scanlines, 512);
+	wp->plane_bytes_per_line = wp->width * wp->cpp;
+	if (wp->y_tiled) {
+		interm_pbpl = DIV_ROUND_UP(wp->plane_bytes_per_line *
+					   wp->y_min_scanlines, 512);
 
 		if (INTEL_GEN(dev_priv) >= 10)
 			interm_pbpl++;
 
-		plane_blocks_per_line = div_fixed16(interm_pbpl,
-							y_min_scanlines);
-	} else if (x_tiled && INTEL_GEN(dev_priv) == 9) {
-		interm_pbpl = DIV_ROUND_UP(plane_bytes_per_line, 512);
-		plane_blocks_per_line = u32_to_fixed16(interm_pbpl);
+		wp->plane_blocks_per_line = div_fixed16(interm_pbpl,
+							wp->y_min_scanlines);
+	} else if (wp->x_tiled && IS_GEN9(dev_priv)) {
+		interm_pbpl = DIV_ROUND_UP(wp->plane_bytes_per_line, 512);
+		wp->plane_blocks_per_line = u32_to_fixed16(interm_pbpl);
 	} else {
-		interm_pbpl = DIV_ROUND_UP(plane_bytes_per_line, 512) + 1;
-		plane_blocks_per_line = u32_to_fixed16(interm_pbpl);
+		interm_pbpl = DIV_ROUND_UP(wp->plane_bytes_per_line, 512) + 1;
+		wp->plane_blocks_per_line = u32_to_fixed16(interm_pbpl);
 	}
 
-	method1 = skl_wm_method1(dev_priv, plane_pixel_rate, cpp, latency);
-	method2 = skl_wm_method2(plane_pixel_rate,
+	wp->y_tile_minimum = mul_u32_fixed16(wp->y_min_scanlines,
+					     wp->plane_blocks_per_line);
+	wp->linetime_us = fixed16_to_u32_round_up(
+					intel_get_linetime_us(cstate));
+
+	return 0;
+}
+
+static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
+				struct intel_crtc_state *cstate,
+				const struct intel_plane_state *intel_pstate,
+				uint16_t ddb_allocation,
+				int level,
+				const struct skl_wm_params *wp,
+				uint16_t *out_blocks, /* out */
+				uint8_t *out_lines, /* out */
+				bool *enabled /* out */)
+{
+	const struct drm_plane_state *pstate = &intel_pstate->base;
+	uint32_t latency = dev_priv->wm.skl_latency[level];
+	uint_fixed_16_16_t method1, method2;
+	uint_fixed_16_16_t selected_result;
+	uint32_t res_blocks, res_lines;
+	struct intel_atomic_state *state =
+		to_intel_atomic_state(cstate->base.state);
+	bool apply_memory_bw_wa = skl_needs_memory_bw_wa(state);
+
+	if (latency == 0 ||
+	    !intel_wm_plane_visible(cstate, intel_pstate)) {
+		*enabled = false;
+		return 0;
+	}
+
+	/* Display WA #1141: kbl,cfl */
+	if ((IS_KABYLAKE(dev_priv) || IS_COFFEELAKE(dev_priv)) &&
+	    dev_priv->ipc_enabled)
+		latency += 4;
+
+	if (apply_memory_bw_wa && wp->x_tiled)
+		latency += 15;
+
+	method1 = skl_wm_method1(dev_priv, wp->plane_pixel_rate,
+				 wp->cpp, latency);
+	method2 = skl_wm_method2(wp->plane_pixel_rate,
 				 cstate->base.adjusted_mode.crtc_htotal,
 				 latency,
-				 plane_blocks_per_line);
-
-	y_tile_minimum = mul_u32_fixed16(y_min_scanlines,
-					 plane_blocks_per_line);
+				 wp->plane_blocks_per_line);
 
-	if (y_tiled) {
-		selected_result = max_fixed16(method2, y_tile_minimum);
+	if (wp->y_tiled) {
+		selected_result = max_fixed16(method2, wp->y_tile_minimum);
 	} else {
-		uint32_t linetime_us;
-
-		linetime_us = fixed16_to_u32_round_up(
-				intel_get_linetime_us(cstate));
-		if ((cpp * cstate->base.adjusted_mode.crtc_htotal / 512 < 1) &&
-		    (plane_bytes_per_line / 512 < 1))
+		if ((wp->cpp * cstate->base.adjusted_mode.crtc_htotal /
+		     512 < 1) && (wp->plane_bytes_per_line / 512 < 1))
 			selected_result = method2;
 		else if (ddb_allocation >=
-			 fixed16_to_u32_round_up(plane_blocks_per_line))
+			 fixed16_to_u32_round_up(wp->plane_blocks_per_line))
 			selected_result = min_fixed16(method1, method2);
-		else if (latency >= linetime_us)
+		else if (latency >= wp->linetime_us)
 			selected_result = min_fixed16(method1, method2);
 		else
 			selected_result = method1;
@@ -4511,19 +4523,18 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
 
 	res_blocks = fixed16_to_u32_round_up(selected_result) + 1;
 	res_lines = div_round_up_fixed16(selected_result,
-					 plane_blocks_per_line);
+					 wp->plane_blocks_per_line);
 
 	/* Display WA #1125: skl,bxt,kbl,glk */
-	if (level == 0 &&
-	    (fb->modifier == I915_FORMAT_MOD_Y_TILED_CCS ||
-	     fb->modifier == I915_FORMAT_MOD_Yf_TILED_CCS))
-		res_blocks += fixed16_to_u32_round_up(y_tile_minimum);
+	if (level == 0 && wp->rc_surface)
+		res_blocks += fixed16_to_u32_round_up(wp->y_tile_minimum);
 
 	/* Display WA #1126: skl,bxt,kbl,glk */
 	if (level >= 1 && level <= 7) {
-		if (y_tiled) {
-			res_blocks += fixed16_to_u32_round_up(y_tile_minimum);
-			res_lines += y_min_scanlines;
+		if (wp->y_tiled) {
+			res_blocks += fixed16_to_u32_round_up(
+							wp->y_tile_minimum);
+			res_lines += wp->y_min_scanlines;
 		} else {
 			res_blocks++;
 		}
@@ -4561,6 +4572,7 @@ skl_compute_wm_levels(const struct drm_i915_private *dev_priv,
 		      struct skl_ddb_allocation *ddb,
 		      struct intel_crtc_state *cstate,
 		      const struct intel_plane_state *intel_pstate,
+		      const struct skl_wm_params *wm_params,
 		      struct skl_plane_wm *wm)
 {
 	struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);
@@ -4584,6 +4596,7 @@ skl_compute_wm_levels(const struct drm_i915_private *dev_priv,
 					   intel_pstate,
 					   ddb_blocks,
 					   level,
+					   wm_params,
 					   &result->plane_res_b,
 					   &result->plane_res_l,
 					   &result->plane_en);
@@ -4648,11 +4661,18 @@ static int skl_build_pipe_wm(struct intel_crtc_state *cstate,
 		const struct intel_plane_state *intel_pstate =
 						to_intel_plane_state(pstate);
 		enum plane_id plane_id = to_intel_plane(plane)->id;
+		struct skl_wm_params wm_params;
 
 		wm = &pipe_wm->planes[plane_id];
+		memset(&wm_params, 0, sizeof(struct skl_wm_params));
+
+		ret = skl_compute_plane_wm_params(dev_priv, cstate,
+						  intel_pstate, &wm_params);
+		if (ret)
+			return ret;
 
 		ret = skl_compute_wm_levels(dev_priv, ddb, cstate,
-					    intel_pstate, wm);
+					    intel_pstate, &wm_params, wm);
 		if (ret)
 			return ret;
 		skl_compute_transition_wm(cstate, &wm->trans_wm);