intel/isl: Add a helper to get a subimage surface

We already have a helper for doing this in BLORP, this just moves the
logic into ISL where we can share it with other components.

Reviewed-by: Lionel Landwerlin <[email protected]>

1 files changed, 23 insertions, 0 deletions

diff --git a/src/intel/isl/isl.h b/src/intel/isl/isl.h
index 1e5b8689542..dafe952298e 100644
--- a/src/intel/isl/isl.h
+++ b/src/intel/isl/isl.h
@@ -1842,6 +1842,29 @@ isl_surf_get_image_offset_B_tile_sa(const struct isl_surf *surf,
                                     uint32_t *y_offset_sa);
 
 /**
+ * Create an isl_surf that represents a particular subimage in the surface.
+ *
+ * The newly created surface will have a single miplevel and array slice.  The
+ * surface lives at the returned byte and intratile offsets, in samples.
+ *
+ * It is safe to call this function with surf == image_surf.
+ *
+ * @invariant level < surface levels
+ * @invariant logical_array_layer < logical array length of surface
+ * @invariant logical_z_offset_px < logical depth of surface at level
+ */
+void
+isl_surf_get_image_surf(const struct isl_device *dev,
+                        const struct isl_surf *surf,
+                        uint32_t level,
+                        uint32_t logical_array_layer,
+                        uint32_t logical_z_offset_px,
+                        struct isl_surf *image_surf,
+                        uint32_t *offset_B,
+                        uint32_t *x_offset_sa,
+                        uint32_t *y_offset_sa);
+
+/**
  * @brief Calculate the intratile offsets to a surface.
  *
  * In @a base_address_offset return the offset from the base of the surface to