drm/i915: Introduce new Tile 4 format

This tiling layout uses 4KB tiles in a row-major layout. It has the same
shape as Tile Y at two granularities: 4KB (128B x 32) and 64B (16B x 4). It
only differs from Tile Y at the 256B granularity in between. At this
granularity, Tile Y has a shape of 16B x 32 rows, but this tiling has a shape
of 64B x 8 rows.
Reviewed-by: Imre Deak <imre.deak@intel.com>
Acked-by: Nanley Chery <nanley.g.chery@intel.com>
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220118115544.15116-2-stanislav.lisovskiy@intel.com

include/uapi/drm/drm_fourcc.h

@@ -572,6 +572,17 @@ extern "C" {
  */
 #define I915_FORMAT_MOD_Y_TILED_GEN12_RC_CCS_CC fourcc_mod_code(INTEL, 8)
 
+/*
+ * Intel Tile 4 layout
+ *
+ * This is a tiled layout using 4KB tiles in a row-major layout. It has the same
+ * shape as Tile Y at two granularities: 4KB (128B x 32) and 64B (16B x 4). It
+ * only differs from Tile Y at the 256B granularity in between. At this
+ * granularity, Tile Y has a shape of 16B x 32 rows, but this tiling has a shape
+ * of 64B x 8 rows.
+ */
+#define I915_FORMAT_MOD_4_TILED         fourcc_mod_code(INTEL, 9)
+
 /*
  * Tiled, NV12MT, grouped in 64 (pixels) x 32 (lines) -sized macroblocks
  *