intel/blorp: Add blorp_surf_convert_to_single_level_tile()

Convert a Tile64/Yf/Ys surface to a single level or a single miptail.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/39974>

src/intel/blorp/blorp_blit.c

@@ -1717,6 +1717,133 @@ blorp_surf_convert_to_single_slice(const struct isl_device *isl_dev,
    info->z_offset = 0;
 }
 
+/* Convert a Tile64/Yf/Ys surface to a single level or a single miptail. */
+static void
+blorp_surf_convert_to_single_level_tile(const struct isl_device *isl_dev,
+                                        struct blorp_surface_info *info,
+                                        bool with_scaling)
+{
+   if (!isl_tiling_is_64(info->surf.tiling) &&
+       !isl_tiling_is_std_y(info->surf.tiling)) {
+      UNREACHABLE("Use blorp_surf_convert_to_single_slice() instead");
+   }
+
+   /* If the requested level is not part of the miptail, we just offset to the
+    * requested level. Because we're using standard tilings and aren't in the
+    * miptail, arrays and 3D textures should just work so long as we have the
+    * right array stride in the end.
+    *
+    * If the requested level is in the miptail, we instead offset to the base
+    * of the miptail.  Because offsets into the miptail are fixed by the
+    * tiling and don't depend on the actual size of the image, we can set the
+    * level in the view to offset into the miptail regardless of the fact
+    * minification yields different results for the unscaled and scaled
+    * surface.
+    */
+   const struct isl_surf *surf = &info->surf;
+   const struct isl_view *view = &info->view;
+   const uint32_t base_level =
+      MIN2(view->base_level, surf->miptail_start_level);
+   assert(view->levels == 1);
+
+   uint64_t offset_B;
+   uint32_t x_offset_el;
+   uint32_t y_offset_el;
+   isl_surf_get_image_offset_B_tile_el(surf, base_level, 0, 0,
+                                       &offset_B, &x_offset_el, &y_offset_el);
+
+   /* Tile64, Ys and Yf should have no intratile X or Y offset */
+   assert(x_offset_el == 0 && y_offset_el == 0);
+   assert(info->tile_x_sa == 0 && info->tile_y_sa == 0);
+   info->addr.offset += offset_B;
+
+   /* Save off the array pitch */
+   const uint32_t array_pitch_el_rows = surf->array_pitch_el_rows;
+
+   const struct isl_format_layout *surf_fmtl =
+      isl_format_get_layout(surf->format);
+   const struct isl_format_layout *view_fmtl =
+      isl_format_get_layout(view->format);
+   assert(isl_format_block_is_1x1x1(view->format));
+   assert(isl_format_block_is_1x1x1(surf->format));
+
+   const uint32_t view_height_el =
+      u_minify(surf->logical_level0_px.height, view->base_level);
+   const uint32_t view_depth_el =
+      u_minify(surf->logical_level0_px.depth, view->base_level);
+   uint32_t view_width_el =
+      u_minify(surf->logical_level0_px.width, view->base_level);
+
+   if (with_scaling) {
+      const int scale = view_fmtl->bpb / surf_fmtl->bpb;
+      view_width_el = DIV_ROUND_UP(view_width_el, scale);
+   } else {
+      assert(view_fmtl->bpb == surf_fmtl->bpb);
+   }
+
+   /* We need to compute the size of the scaled surface we will create. If
+    * we're not in the miptail, it is just the view size in surface
+    * elements. If we are in a miptail, we need a size that will minify to
+    * the view size in surface elements. This may not be the same as the
+    * size of base_level, but that's not a problem. Slot offsets are fixed
+    * in HW (see the tables used in isl_get_miptail_level_offset_el).
+    */
+   const uint32_t scaled_level = view->base_level - base_level;
+
+   /* The > 1 check is here to prevent a change in the surface's overall
+    * dimension (e.g. 2D->3D).
+    *
+    * Also having a base_level dimension = 1 doesn´t mean the HW will
+    * ignore higher mip level. Once the dimension has reached 1, it'll stay
+    * at 1 in the higher mip levels.
+    */
+   struct isl_extent3d scaled_surf_extent_el = {
+      .w = view_width_el  > 1 ? view_width_el  << scaled_level : 1,
+      .h = view_height_el > 1 ? view_height_el << scaled_level : 1,
+      .d = view_depth_el  > 1 ? view_depth_el  << scaled_level : 1,
+   };
+
+   isl_surf_usage_flags_t usage = surf->usage;
+   /* CCS-enabled surfaces can have different layout requirements than
+    * surfaces without CCS support. Disable CCS support if the original
+    * surface lacked it.
+    */
+   if (info->aux_usage == ISL_AUX_USAGE_NONE)
+      usage |= ISL_SURF_USAGE_DISABLE_AUX_BIT;
+
+   struct isl_surf *scaled_surf = &info->surf;
+   struct isl_view *scaled_view = &info->view;
+   bool ok UNUSED;
+   ok = isl_surf_init(isl_dev, scaled_surf,
+                      .dim = surf->dim,
+                      .format = view->format,
+                      .width = scaled_surf_extent_el.width,
+                      .height = scaled_surf_extent_el.height,
+                      .depth = scaled_surf_extent_el.depth,
+                      .levels = scaled_level + 1,
+                      .array_len = surf->logical_level0_px.array_len,
+                      .samples = surf->samples,
+                      .min_miptail_start_level =
+                         (int) (view->base_level < surf->miptail_start_level),
+                      .row_pitch_B = surf->row_pitch_B,
+                      .usage = usage,
+                      .tiling_flags = (1u << surf->tiling));
+   assert(ok);
+
+   /* Use the array pitch from the original surface.  This way 2D arrays and
+    * 3D textures should work properly, just with one LOD.
+    */
+   assert(scaled_surf->array_pitch_el_rows <= array_pitch_el_rows);
+   scaled_surf->array_pitch_el_rows = array_pitch_el_rows;
+
+   /* The newly created image represents only the one miplevel so we need to
+    * adjust the view accordingly.  Because we offset it to miplevel but used
+    * a Z and array slice of 0, the array range can be left alone.
+    */
+   *scaled_view = *view;
+   scaled_view->base_level -= base_level;
+}
+
 void
 blorp_surf_fake_interleaved_msaa(const struct isl_device *isl_dev,
                                  struct blorp_surface_info *info)