drm/i915: Bump DSL linemask to 20 bits

Since tgl PIPE_DSL has 20 bits for the scanline. Let's bump our
definition to match. And while at it let's also add the define
for the current field readback.

We can also get rid of the gen2 vs. gen3+ nonsense since none
of the extra bits ever did anything and just always read
as zero. And now we extend all platforms to use the tgl+
20 bits deinition, but again that is fine since all the bits
used to be mbz and always read as zero on all the platforms.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211112193813.8224-2-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

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

@@ -353,16 +353,10 @@ static bool pipe_scanline_is_moving(struct drm_i915_private *dev_priv,
 {
 	i915_reg_t reg = PIPEDSL(pipe);
 	u32 line1, line2;
-	u32 line_mask;
 
-	if (DISPLAY_VER(dev_priv) == 2)
-		line_mask = DSL_LINEMASK_GEN2;
-	else
-		line_mask = DSL_LINEMASK_GEN3;
-
-	line1 = intel_de_read(dev_priv, reg) & line_mask;
+	line1 = intel_de_read(dev_priv, reg) & PIPEDSL_LINE_MASK;
 	msleep(5);
-	line2 = intel_de_read(dev_priv, reg) & line_mask;
+	line2 = intel_de_read(dev_priv, reg) & PIPEDSL_LINE_MASK;
 
 	return line1 != line2;
 }

drivers/gpu/drm/i915/i915_irq.c

@@ -836,10 +836,7 @@ static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 		vtotal /= 2;
 
-	if (DISPLAY_VER(dev_priv) == 2)
-		position = intel_de_read_fw(dev_priv, PIPEDSL(pipe)) & DSL_LINEMASK_GEN2;
-	else
-		position = intel_de_read_fw(dev_priv, PIPEDSL(pipe)) & DSL_LINEMASK_GEN3;
+	position = intel_de_read_fw(dev_priv, PIPEDSL(pipe)) & PIPEDSL_LINE_MASK;
 
 	/*
 	 * On HSW, the DSL reg (0x70000) appears to return 0 if we
@@ -858,7 +855,7 @@ static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
 
 		for (i = 0; i < 100; i++) {
 			udelay(1);
-			temp = intel_de_read_fw(dev_priv, PIPEDSL(pipe)) & DSL_LINEMASK_GEN3;
+			temp = intel_de_read_fw(dev_priv, PIPEDSL(pipe)) & PIPEDSL_LINE_MASK;
 			if (temp != position) {
 				position = temp;
 				break;

drivers/gpu/drm/i915/i915_reg.h

@@ -5165,8 +5165,8 @@ enum {
 
 /* Pipe A */
 #define _PIPEADSL		0x70000
-#define   DSL_LINEMASK_GEN2	0x00000fff
-#define   DSL_LINEMASK_GEN3	0x00001fff
+#define   PIPEDSL_CURR_FIELD	REG_BIT(31) /* ctg+ */
+#define   PIPEDSL_LINE_MASK	REG_GENMASK(19, 0)
 #define _PIPEACONF		0x70008
 #define   PIPECONF_ENABLE	(1 << 31)
 #define   PIPECONF_DISABLE	0