[PATCH v3 4/7] riscv: Clear pending IPIs on initialization

[Rick Chen]

> Even though we no longer call smp_function if an IPI was not sent by
> U-Boot, we still need to clear any IPIs which were pending from the
> execution environment. Otherwise, secondary harts will busy-wait in
> secondary_hart_loop, instead of relaxing.
>
> Along with the previous commit ("riscv: Use a valid bit to ignore
> already-pending IPIs"), this fixes SMP booting on the Kendryte K210.
>
> Signed-off-by: Sean Anderson <seanga2 at gmail.com>
> Reviewed-by: Bin Meng <bin.meng at windriver.com>
>
> ---
>
> Changes in v3:
> - Rename riscv_ipi_init_secondary_hart to dummy_pending_ipi_clear
> - Only compile dummy_pending_ipi_clear when SMP is enabled
>
> Changes in v2:
> - Make riscv_ipi_init_secondary_hart static
>
>  arch/riscv/cpu/cpu.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>

Reviewed-by: Rick Chen <rick at andestech.com>