tree c1f7e822e73d88ff13c04d723fbf7e15a27270a2
parent 8de4b3e0c9227c5fd4cae35828d2f1324d8c3fec
author Lukas Auer <lukas.auer@aisec.fraunhofer.de> 1552847317 +0100
committer Andes <uboot@andestech.com> 1554687866 +0800

riscv: add support for multi-hart systems

On RISC-V, all harts boot independently. To be able to run on a
multi-hart system, U-Boot must be extended with the functionality to
manage all harts in the system. All harts entering U-Boot are registered
in the available_harts mask stored in global data. A hart lottery system
as used in the Linux kernel selects the hart U-Boot runs on. All other
harts are halted. U-Boot can delegate functions to them using
smp_call_function().

Every hart has a valid pointer to the global data structure and a 8KiB
stack by default. The stack size is set with CONFIG_STACK_SIZE_SHIFT.

Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>