DBCSR's OpenCL accelerator path no longer carries a separate src/acc/opencl/smm implementation in the documentation tree. The OpenCL SMM code, sample benchmark, tuned-parameter files, and OpenTuner workflow are maintained in LIBXSTREAM. LIBXSTREAM in turn uses LIBXS, which also provides host-side batched small matrix multiplication support relevant to DBCSR's CPU path.
Inside DBCSR, -DUSE_ACCEL=opencl enables the OpenCL accelerator backend. The build requires OpenCL headers/runtime support, LIBXS, and LIBXSTREAM; CMake can use prebuilt installations through pkg-config, LIBXSROOT, and LIBXSTREAMROOT, or obtain sources through the configured dependency mechanism.
For kernel-level experimentation, benchmarking, tuned-parameter management, and auto-tuning, use the LIBXSTREAM SMM sample documentation rather than the historical DBCSR OpenCL tuning notes.