ail: Introduce layer_alignment flag

The hardware uses this flag to determine whether layer strides are
implicitly aligned to the page size or not.

Signed-off-by: Asahi Lina <lina@asahilina.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20031>

src/asahi/layout/layout.c

@@ -168,6 +168,9 @@ ail_initialize_twiddled(struct ail_layout *layout)
     */
    if ((layout->levels != 1 && layout->depth_px != 1 && offset_B > AIL_PAGESIZE)
         || layout->tiling != AIL_TILING_TWIDDLED_COMPRESSED)
+      layout->page_aligned_layers = true;
+
+   if (layout->page_aligned_layers)
       layout->layer_stride_B = ALIGN_POT(offset_B, AIL_PAGESIZE);
    else
       layout->layer_stride_B = offset_B;

src/asahi/layout/layout.h

@@ -99,6 +99,12 @@ struct ail_layout {
     */
    uint32_t layer_stride_B;
 
+   /**
+    * Whether the layer stride is aligned to the page size or not. The hardware
+    * needs this flag to compute the implicit layer stride.
+    */
+   bool page_aligned_layers;
+
    /**
     * Offsets of mip levels within a layer.
     */