The RISC-V CPU architecture changes have been merged for the in-development Linux 6.19 kernel.
With this new kernel RISC-V now supports CPU hot-plugging in parallel for secondary CPU cores. Secondary CPU cores can now be brought up asynchronously with the "HOTPLUG_PARALLEL" kernel feature now being supported on RISC-V for more quickly bringing up multiple CPU cores besides the primary CPU0. The CPU hot-plugging support particularly with RISC-V SoCs is primarily about dynamic enabling/disabling of CPU cores while the system is running rather than needing to handle their bring-up sequentially.
