RISC-V: Add supported for ordered booting method using HSM

2020-03-31T18:27:50Z

Currently, all harts have to jump Linux in RISC-V. This complicates the multi-stage boot process as every transient stage also has to ensure all harts enter to that stage and jump to Linux afterwards. It also obstructs a clean Kexec implementation. SBI HSM extension provides alternate solutions where only a single hart need to boot and enter Linux. The booting hart can bring up secondary harts one by one afterwards. Add SBI HSM based cpu_ops that implements an ordered booting method in RISC-V. This change is also backward compatible with older firmware not implementing HSM extension. If a latest kernel is used with older firmware, it will continue to use the default spinning booting method. Signed-off-by: Atish Patra Reviewed-by: Anup Patel Signed-off-by: Palmer Dabbelt

RISC-V: Add cpu_ops and modify default booting method

2020-03-31T18:25:56Z

Currently, all non-booting harts start booting after the booting hart updates the per-hart stack pointer. This is done in a way that, it's difficult to implement any other booting method without breaking the backward compatibility. Define a cpu_ops method that allows to introduce other booting methods in future. Modify the current booting method to be compatible with cpu_ops. Signed-off-by: Atish Patra Reviewed-by: Anup Patel Signed-off-by: Palmer Dabbelt

wireguard-linux/arch/riscv/kernel/cpu_ops.c, branch jd/unified-crypt-queue

RISC-V: Add supported for ordered booting method using HSM

RISC-V: Add cpu_ops and modify default booting method