ail: report mip_tail_first_lod for sparse

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33682>

src/asahi/layout/layout.c

@@ -175,6 +175,11 @@ ail_initialize_twiddled(struct ail_layout *layout)
    assert(layout->levels < ARRAY_SIZE(layout->level_offsets_B));
    layout->level_offsets_B[layout->levels] = offset_B;
 
+   /* Determine the start of the miptail. From that level on, we can no longer
+    * precisely bind at page granularity.
+    */
+   layout->mip_tail_first_lod = MIN2(pot_level, layout->levels);
+
    /* Align layer size if we have mipmaps and one miptree is larger than one
     * page */
    layout->page_aligned_layers = layout->levels != 1 && offset_B > AIL_PAGESIZE;

src/asahi/layout/layout.h

@@ -118,6 +118,12 @@ struct ail_layout {
     */
    uint32_t stride_el[AIL_MAX_MIP_LEVELS];
 
+   /**
+    * If the image is bound sparsely, the first LOD/level of the miptail.
+    * This corresponds to Vulkan imageMipTailFirstLod.
+    */
+   uint32_t mip_tail_first_lod;
+
    /* Offset of the start of the compression metadata buffer */
    uint32_t metadata_offset_B;