drm/i915: Split gen2 vs. gen3 .max_stride()

Plane .max_stride() is already a vfunc so having one made
up of two branches based on the display version is silly.
Split i9xx_plane_max_stride() into gen2 vs. gen3 variants
so  that we get rid of said check.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240506125718.26001-2-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/display/i9xx_plane.c

@@ -741,23 +741,25 @@ i965_plane_max_stride(struct intel_plane *plane,
 }
 
 static unsigned int
-i9xx_plane_max_stride(struct intel_plane *plane,
+i915_plane_max_stride(struct intel_plane *plane,
 		      u32 pixel_format, u64 modifier,
 		      unsigned int rotation)
 {
-	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
+	if (modifier == I915_FORMAT_MOD_X_TILED)
+		return 8 * 1024;
+	else
+		return 16 * 1024;
+}
 
-	if (DISPLAY_VER(dev_priv) >= 3) {
-		if (modifier == I915_FORMAT_MOD_X_TILED)
-			return 8*1024;
-		else
-			return 16*1024;
-	} else {
-		if (plane->i9xx_plane == PLANE_C)
-			return 4*1024;
-		else
-			return 8*1024;
-	}
+static unsigned int
+i8xx_plane_max_stride(struct intel_plane *plane,
+		      u32 pixel_format, u64 modifier,
+		      unsigned int rotation)
+{
+	if (plane->i9xx_plane == PLANE_C)
+		return 4 * 1024;
+	else
+		return 8 * 1024;
 }
 
 static const struct drm_plane_funcs i965_plane_funcs = {
@@ -854,8 +856,10 @@ intel_primary_plane_create(struct drm_i915_private *dev_priv, enum pipe pipe)
 	if (HAS_GMCH(dev_priv)) {
 		if (DISPLAY_VER(dev_priv) >= 4)
 			plane->max_stride = i965_plane_max_stride;
+		else if (DISPLAY_VER(dev_priv) == 3)
+			plane->max_stride = i915_plane_max_stride;
 		else
-			plane->max_stride = i9xx_plane_max_stride;
+			plane->max_stride = i8xx_plane_max_stride;
 	} else {
 		if (IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
 			plane->max_stride = hsw_primary_max_stride;