drm/i915: Move the DSB->mmio fallback into the LUT code

The use of DSB has to be done differently on a case by case basis.
So no way this kind of blind mmio fallback in the guts of the DSB
code will work properly. Move it at least one level up into the
LUT loading code. Not sure if this is the way we want do the
DSB vs. mmio handling in the end, but at least it's a bit
closer than what we had before.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221123152638.20622-8-ville.syrjala@linux.intel.comReviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>

drivers/gpu/drm/i915/display/intel_color.c

@@ -836,6 +836,28 @@ static void i965_load_luts(const struct intel_crtc_state *crtc_state)
 	}
 }
 
+static void ilk_lut_write(const struct intel_crtc_state *crtc_state,
+			  i915_reg_t reg, u32 val)
+{
+	struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev);
+
+	if (crtc_state->dsb)
+		intel_dsb_reg_write(crtc_state, reg, val);
+	else
+		intel_de_write_fw(i915, reg, val);
+}
+
+static void ilk_lut_write_indexed(const struct intel_crtc_state *crtc_state,
+				  i915_reg_t reg, u32 val)
+{
+	struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev);
+
+	if (crtc_state->dsb)
+		intel_dsb_indexed_reg_write(crtc_state, reg, val);
+	else
+		intel_de_write_fw(i915, reg, val);
+}
+
 static void ilk_load_lut_8(struct intel_crtc *crtc,
 			   const struct drm_property_blob *blob)
 {
@@ -958,9 +980,9 @@ static void ivb_load_lut_ext_max(const struct intel_crtc_state *crtc_state)
 	enum pipe pipe = crtc->pipe;
 
 	/* Program the max register to clamp values > 1.0. */
-	intel_dsb_reg_write(crtc_state, PREC_PAL_EXT_GC_MAX(pipe, 0), 1 << 16);
-	intel_dsb_reg_write(crtc_state, PREC_PAL_EXT_GC_MAX(pipe, 1), 1 << 16);
-	intel_dsb_reg_write(crtc_state, PREC_PAL_EXT_GC_MAX(pipe, 2), 1 << 16);
+	ilk_lut_write(crtc_state, PREC_PAL_EXT_GC_MAX(pipe, 0), 1 << 16);
+	ilk_lut_write(crtc_state, PREC_PAL_EXT_GC_MAX(pipe, 1), 1 << 16);
+	ilk_lut_write(crtc_state, PREC_PAL_EXT_GC_MAX(pipe, 2), 1 << 16);
 }
 
 static void glk_load_lut_ext2_max(const struct intel_crtc_state *crtc_state)
@@ -969,9 +991,9 @@ static void glk_load_lut_ext2_max(const struct intel_crtc_state *crtc_state)
 	enum pipe pipe = crtc->pipe;
 
 	/* Program the max register to clamp values > 1.0. */
-	intel_dsb_reg_write(crtc_state, PREC_PAL_EXT2_GC_MAX(pipe, 0), 1 << 16);
-	intel_dsb_reg_write(crtc_state, PREC_PAL_EXT2_GC_MAX(pipe, 1), 1 << 16);
-	intel_dsb_reg_write(crtc_state, PREC_PAL_EXT2_GC_MAX(pipe, 2), 1 << 16);
+	ilk_lut_write(crtc_state, PREC_PAL_EXT2_GC_MAX(pipe, 0), 1 << 16);
+	ilk_lut_write(crtc_state, PREC_PAL_EXT2_GC_MAX(pipe, 1), 1 << 16);
+	ilk_lut_write(crtc_state, PREC_PAL_EXT2_GC_MAX(pipe, 2), 1 << 16);
 }
 
 static void ivb_load_luts(const struct intel_crtc_state *crtc_state)
@@ -1118,9 +1140,9 @@ ivb_load_lut_max(const struct intel_crtc_state *crtc_state,
 	enum pipe pipe = crtc->pipe;
 
 	/* FIXME LUT entries are 16 bit only, so we can prog 0xFFFF max */
-	intel_dsb_reg_write(crtc_state, PREC_PAL_GC_MAX(pipe, 0), color->red);
-	intel_dsb_reg_write(crtc_state, PREC_PAL_GC_MAX(pipe, 1), color->green);
-	intel_dsb_reg_write(crtc_state, PREC_PAL_GC_MAX(pipe, 2), color->blue);
+	ilk_lut_write(crtc_state, PREC_PAL_GC_MAX(pipe, 0), color->red);
+	ilk_lut_write(crtc_state, PREC_PAL_GC_MAX(pipe, 1), color->green);
+	ilk_lut_write(crtc_state, PREC_PAL_GC_MAX(pipe, 2), color->blue);
 }
 
 static void
@@ -1139,23 +1161,23 @@ icl_program_gamma_superfine_segment(const struct intel_crtc_state *crtc_state)
 	 * 9 entries, corresponding to values 0, 1/(8 * 128 * 256),
 	 * 2/(8 * 128 * 256) ... 8/(8 * 128 * 256).
 	 */
-	intel_dsb_reg_write(crtc_state, PREC_PAL_MULTI_SEG_INDEX(pipe),
-			    PAL_PREC_MULTI_SEG_INDEX_VALUE(0));
-	intel_dsb_reg_write(crtc_state, PREC_PAL_MULTI_SEG_INDEX(pipe),
-			    PAL_PREC_AUTO_INCREMENT |
-			    PAL_PREC_MULTI_SEG_INDEX_VALUE(0));
+	ilk_lut_write(crtc_state, PREC_PAL_MULTI_SEG_INDEX(pipe),
+		      PAL_PREC_MULTI_SEG_INDEX_VALUE(0));
+	ilk_lut_write(crtc_state, PREC_PAL_MULTI_SEG_INDEX(pipe),
+		      PAL_PREC_AUTO_INCREMENT |
+		      PAL_PREC_MULTI_SEG_INDEX_VALUE(0));
 
 	for (i = 0; i < 9; i++) {
 		const struct drm_color_lut *entry = &lut[i];
 
-		intel_dsb_indexed_reg_write(crtc_state, PREC_PAL_MULTI_SEG_DATA(pipe),
-					    ilk_lut_12p4_ldw(entry));
-		intel_dsb_indexed_reg_write(crtc_state, PREC_PAL_MULTI_SEG_DATA(pipe),
-					    ilk_lut_12p4_udw(entry));
+		ilk_lut_write_indexed(crtc_state, PREC_PAL_MULTI_SEG_DATA(pipe),
+				      ilk_lut_12p4_ldw(entry));
+		ilk_lut_write_indexed(crtc_state, PREC_PAL_MULTI_SEG_DATA(pipe),
+				      ilk_lut_12p4_udw(entry));
 	}
 
-	intel_dsb_reg_write(crtc_state, PREC_PAL_MULTI_SEG_INDEX(pipe),
-			    PAL_PREC_MULTI_SEG_INDEX_VALUE(0));
+	ilk_lut_write(crtc_state, PREC_PAL_MULTI_SEG_INDEX(pipe),
+		      PAL_PREC_MULTI_SEG_INDEX_VALUE(0));
 }
 
 static void
@@ -1178,18 +1200,19 @@ icl_program_gamma_multi_segment(const struct intel_crtc_state *crtc_state)
 	 * PAL_PREC_INDEX[0] and PAL_PREC_INDEX[1] map to seg2[1],
 	 * seg2[0] being unused by the hardware.
 	 */
-	intel_dsb_reg_write(crtc_state, PREC_PAL_INDEX(pipe),
-			    PAL_PREC_INDEX_VALUE(0));
-	intel_dsb_reg_write(crtc_state, PREC_PAL_INDEX(pipe),
-			    PAL_PREC_AUTO_INCREMENT |
-			    PAL_PREC_INDEX_VALUE(0));
+	ilk_lut_write(crtc_state, PREC_PAL_INDEX(pipe),
+		      PAL_PREC_INDEX_VALUE(0));
+	ilk_lut_write(crtc_state, PREC_PAL_INDEX(pipe),
+		      PAL_PREC_AUTO_INCREMENT |
+		      PAL_PREC_INDEX_VALUE(0));
 
 	for (i = 1; i < 257; i++) {
 		entry = &lut[i * 8];
-		intel_dsb_indexed_reg_write(crtc_state, PREC_PAL_DATA(pipe),
-					    ilk_lut_12p4_ldw(entry));
-		intel_dsb_indexed_reg_write(crtc_state, PREC_PAL_DATA(pipe),
-					    ilk_lut_12p4_udw(entry));
+
+		ilk_lut_write_indexed(crtc_state, PREC_PAL_DATA(pipe),
+				      ilk_lut_12p4_ldw(entry));
+		ilk_lut_write_indexed(crtc_state, PREC_PAL_DATA(pipe),
+				      ilk_lut_12p4_udw(entry));
 	}
 
 	/*
@@ -1206,14 +1229,15 @@ icl_program_gamma_multi_segment(const struct intel_crtc_state *crtc_state)
 	 */
 	for (i = 0; i < 256; i++) {
 		entry = &lut[i * 8 * 128];
-		intel_dsb_indexed_reg_write(crtc_state, PREC_PAL_DATA(pipe),
-					    ilk_lut_12p4_ldw(entry));
-		intel_dsb_indexed_reg_write(crtc_state, PREC_PAL_DATA(pipe),
-					    ilk_lut_12p4_udw(entry));
+
+		ilk_lut_write_indexed(crtc_state, PREC_PAL_DATA(pipe),
+				      ilk_lut_12p4_ldw(entry));
+		ilk_lut_write_indexed(crtc_state, PREC_PAL_DATA(pipe),
+				      ilk_lut_12p4_udw(entry));
 	}
 
-	intel_dsb_reg_write(crtc_state, PREC_PAL_INDEX(pipe),
-			    PAL_PREC_INDEX_VALUE(0));
+	ilk_lut_write(crtc_state, PREC_PAL_INDEX(pipe),
+		      PAL_PREC_INDEX_VALUE(0));
 
 	/* The last entry in the LUT is to be programmed in GCMAX */
 	entry = &lut[256 * 8 * 128];

drivers/gpu/drm/i915/display/intel_dsb.c

@@ -129,14 +129,9 @@ void intel_dsb_indexed_reg_write(const struct intel_crtc_state *crtc_state,
 	struct intel_dsb *dsb = crtc_state->dsb;
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
-	u32 *buf;
+	u32 *buf = dsb->cmd_buf;
 	u32 reg_val;
 
-	if (!dsb) {
-		intel_de_write_fw(dev_priv, reg, val);
-		return;
-	}
-	buf = dsb->cmd_buf;
 	if (drm_WARN_ON(&dev_priv->drm, dsb->free_pos >= DSB_BUF_SIZE)) {
 		drm_dbg_kms(&dev_priv->drm, "DSB buffer overflow\n");
 		return;
@@ -205,16 +200,9 @@ void intel_dsb_reg_write(const struct intel_crtc_state *crtc_state,
 {
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
-	struct intel_dsb *dsb;
-	u32 *buf;
-
-	dsb = crtc_state->dsb;
-	if (!dsb) {
-		intel_de_write_fw(dev_priv, reg, val);
-		return;
-	}
+	struct intel_dsb *dsb = crtc_state->dsb;
+	u32 *buf = dsb->cmd_buf;
 
-	buf = dsb->cmd_buf;
 	if (drm_WARN_ON(&dev_priv->drm, dsb->free_pos >= DSB_BUF_SIZE)) {
 		drm_dbg_kms(&dev_priv->drm, "DSB buffer overflow\n");
 		return;