intel/aux_map: add helper to compute offset in aux data

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jianxun Zhang <jianxun.zhang@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26822>

src/intel/common/intel_aux_map.c

@@ -248,6 +248,13 @@ intel_aux_get_main_to_aux_ratio(struct intel_aux_map_context *ctx)
    return ctx->format->main_to_aux_ratio;
 }
 
+uint64_t
+intel_aux_main_to_aux_offset(struct intel_aux_map_context *ctx,
+                             uint64_t main_offset)
+{
+   return main_offset / ctx->format->main_to_aux_ratio;
+}
+
 static const struct aux_format_info *
 get_format(enum intel_aux_map_format format)
 {

src/intel/common/intel_aux_map.h

@@ -84,6 +84,14 @@ intel_aux_get_meta_address_mask(struct intel_aux_map_context *ctx);
 uint64_t
 intel_aux_get_main_to_aux_ratio(struct intel_aux_map_context *ctx);
 
+/**
+ * Takes a relative offset in the main surface and returns a relative offset
+ * in the aux surface that maps to the main offset.
+ */
+uint64_t
+intel_aux_main_to_aux_offset(struct intel_aux_map_context *ctx,
+                             uint64_t main_offset);
+
 /**
  * Fill an array of exec_object2 with aux-map buffer handles
  *