reproduce (this is a W=1 build):
        # https://github.com/avpatel/linux/commit/5c381ad05935a6c1e0108a97d1197952ca46201e
        git remote add avpatel https://github.com/avpatel/linux.git
        git fetch --no-tags avpatel riscv_trace_acpi_support_v1
        git checkout 5c381ad05935a6c1e0108a97d1197952ca46201e

        # install sparc64 cross compiling tool for clang build
        # apt-get install binutils-sparc64-linux-gnu
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=sparc64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=sparc64 SHELL=/bin/bash drivers/hwtracing/gtrace/