+/* A subset of the valid tiled formats can be compressed. We do
+ * already require tiled in order to be compressed, but just because
+ * it can be tiled doesn't mean it can be compressed.
+ */
+static bool
+ok_ubwc_format(enum pipe_format pfmt)
+{
+ /* NOTE: both x24s8 and z24s8 map to RB6_X8Z24_UNORM, but UBWC
+ * does not seem to work properly when sampling x24s8.. possibly
+ * because we sample it as TFMT6_8_8_8_8_UINT.
+ *
+ * This could possibly be a hw limitation, or maybe something
+ * else wrong somewhere (although z24s8 blits and sampling with
+ * UBWC seem fine). Recheck on a later revision of a6xx
+ */
+ if (pfmt == PIPE_FORMAT_X24S8_UINT)
+ return false;
+
+ switch (fd6_pipe2color(pfmt)) {
+ case RB6_R10G10B10A2_UINT:
+ case RB6_R10G10B10A2_UNORM:
+ case RB6_R11G11B10_FLOAT:
+ case RB6_R16_FLOAT:
+ case RB6_R16G16B16A16_FLOAT:
+ case RB6_R16G16B16A16_SINT:
+ case RB6_R16G16B16A16_UINT:
+ case RB6_R16G16_FLOAT:
+ case RB6_R16G16_SINT:
+ case RB6_R16G16_UINT:
+ case RB6_R16_SINT:
+ case RB6_R16_UINT:
+ case RB6_R32G32B32A32_SINT:
+ case RB6_R32G32B32A32_UINT:
+ case RB6_R32G32_SINT:
+ case RB6_R32G32_UINT:
+ case RB6_R5G6B5_UNORM:
+ case RB6_R8G8B8A8_SINT:
+ case RB6_R8G8B8A8_UINT:
+ case RB6_R8G8B8A8_UNORM:
+ case RB6_R8G8B8_UNORM:
+ case RB6_R8G8_SINT:
+ case RB6_R8G8_UINT:
+ case RB6_R8G8_UNORM:
+ case RB6_Z24_UNORM_S8_UINT:
+ case RB6_Z24_UNORM_S8_UINT_AS_R8G8B8A8:
+ return true;
+ default:
+ return false;
+ }
+}
+
+uint32_t
+fd6_fill_ubwc_buffer_sizes(struct fd_resource *rsc)
+{
+#define RBG_TILE_WIDTH_ALIGNMENT 64
+#define RGB_TILE_HEIGHT_ALIGNMENT 16
+#define UBWC_PLANE_SIZE_ALIGNMENT 4096
+
+ struct pipe_resource *prsc = &rsc->base;
+ uint32_t width = prsc->width0;
+ uint32_t height = prsc->height0;
+
+ if (!ok_ubwc_format(prsc->format))
+ return 0;
+
+ /* limit things to simple single level 2d for now: */
+ if ((prsc->depth0 != 1) || (prsc->array_size != 1) || (prsc->last_level != 0))
+ return 0;
+
+ uint32_t block_width, block_height;
+ switch (rsc->layout.cpp) {
+ case 2:
+ case 4:
+ block_width = 16;
+ block_height = 4;
+ break;
+ case 8:
+ block_width = 8;
+ block_height = 4;
+ break;
+ case 16:
+ block_width = 4;
+ block_height = 4;
+ break;
+ default:
+ return 0;
+ }
+
+ uint32_t meta_stride =
+ ALIGN_POT(DIV_ROUND_UP(width, block_width), RBG_TILE_WIDTH_ALIGNMENT);
+ uint32_t meta_height =
+ ALIGN_POT(DIV_ROUND_UP(height, block_height), RGB_TILE_HEIGHT_ALIGNMENT);
+ uint32_t meta_size =
+ ALIGN_POT(meta_stride * meta_height, UBWC_PLANE_SIZE_ALIGNMENT);
+
+ /* UBWC goes first, then color data.. this constraint is mainly only
+ * because it is what the kernel expects for scanout. For non-2D we
+ * could just use a separate UBWC buffer..
+ */
+ rsc->layout.ubwc_offset = 0;
+ rsc->layout.offset = meta_size;
+ rsc->layout.ubwc_pitch = meta_stride;
+ rsc->layout.ubwc_size = meta_size >> 2; /* in dwords??? */
+ rsc->layout.tile_mode = TILE6_3;
+
+ return meta_size;
+}
+
+/**
+ * Ensure the rsc is in an ok state to be used with the specified format.
+ * This handles the case of UBWC buffers used with non-UBWC compatible
+ * formats, by triggering an uncompress.
+ */
+void
+fd6_validate_format(struct fd_context *ctx, struct fd_resource *rsc,
+ enum pipe_format format)
+{
+ if (!rsc->layout.ubwc_size)
+ return;
+
+ if (ok_ubwc_format(format))
+ return;
+
+ fd_resource_uncompress(ctx, rsc);
+}
+