[cuda] Move to hal/drivers and wire up BUILD files

This commit moves the CUDA HAL driver rewrite to the
`hal/drivers` directory given it's functional and ready for
normal usage. By this we can start run tests with CI
to make sure it does not regress. Further improvements
can happen directly in this directory.

This provides an easy route for trying out the rewrite before
eventually replace the existing HAL driver.

Along the way wired up BUILD configurations.

.github/CODEOWNERS

@@ -79,5 +79,6 @@
 # Runtime
 /runtime/src/iree/ @benvanik
 /runtime/src/iree/hal/cts/ @ScottTodd
+/runtime/src/iree/hal/drivers/cuda2/ @antiagainst
 /runtime/src/iree/hal/drivers/metal/ @antiagainst
 /runtime/src/iree/hal/drivers/vulkan/ @antiagainst @ScottTodd

CMakeLists.txt

@@ -239,8 +239,10 @@ option(IREE_HAL_DRIVER_DEFAULTS "Sets the default value for all runtime HAL driv
 # not cross compiling. Note: a CUDA-compatible GPU with drivers is still
 # required to actually run CUDA workloads.
 set(IREE_HAL_DRIVER_CUDA_DEFAULT ${IREE_HAL_DRIVER_DEFAULTS})
+set(IREE_HAL_DRIVER_CUDA2_DEFAULT ${IREE_HAL_DRIVER_DEFAULTS})
 if(NOT IREE_CUDA_AVAILABLE OR CMAKE_CROSSCOMPILING)
   set(IREE_HAL_DRIVER_CUDA_DEFAULT OFF)
+  set(IREE_HAL_DRIVER_CUDA2_DEFAULT OFF)
 endif()
 
 # Vulkan support is enabled by default if the platform might support Vulkan.
@@ -258,6 +260,7 @@ if(NOT APPLE OR NOT ${CMAKE_SYSTEM_PROCESSOR} MATCHES "arm64")
 endif()
 
 option(IREE_HAL_DRIVER_CUDA "Enables the 'cuda' runtime HAL driver" ${IREE_HAL_DRIVER_CUDA_DEFAULT})
+option(IREE_HAL_DRIVER_CUDA2 "Enables the 'cuda2' runtime HAL driver" ${IREE_HAL_DRIVER_CUDA2_DEFAULT})
 option(IREE_HAL_DRIVER_LOCAL_SYNC "Enables the 'local-sync' runtime HAL driver" ${IREE_HAL_DRIVER_DEFAULTS})
 option(IREE_HAL_DRIVER_LOCAL_TASK "Enables the 'local-task' runtime HAL driver" ${IREE_HAL_DRIVER_DEFAULTS})
 option(IREE_HAL_DRIVER_VULKAN "Enables the 'vulkan' runtime HAL driver" ${IREE_HAL_DRIVER_VULKAN_DEFAULT})
@@ -313,6 +316,9 @@ message(STATUS "IREE HAL drivers:")
 if(IREE_HAL_DRIVER_CUDA)
   message(STATUS "  - cuda")
 endif()
+if(IREE_HAL_DRIVER_CUDA2)
+  message(STATUS "  - cuda2")
+endif()
 if(IREE_HAL_DRIVER_LOCAL_SYNC)
   message(STATUS "  - local-sync")
 endif()
@@ -575,22 +581,6 @@ set(IREE_PACKAGE_ROOT_PREFIX "iree")
 
 set(CMAKE_POSITION_INDEPENDENT_CODE TRUE)
 
-#-------------------------------------------------------------------------------
-# Experimental next-generation CUDA HAL driver
-# Enable with: -DIREE_EXTERNAL_HAL_DRIVERS=cuda2
-#-------------------------------------------------------------------------------
-
-iree_register_external_hal_driver(
-  NAME
-    cuda2
-  SOURCE_DIR
-    "${CMAKE_CURRENT_SOURCE_DIR}/experimental/cuda2"
-  DRIVER_TARGET
-    iree::experimental::cuda2::registration
-  REGISTER_FN
-    iree_hal_cuda2_driver_module_register
-)
-
 #-------------------------------------------------------------------------------
 # Experimental ROCM HAL driver
 # Enable with: -DIREE_EXTERNAL_HAL_DRIVERS=rocm