[PATCH v2 5/7] riscv: Consolidate fences into AMOs for available_harts_lock

[Rick Chen]

> We can reduce the number of instructions needed to use available_harts_lock
> by using the aq and rl suffixes for AMOs.
>
> Signed-off-by: Sean Anderson <seanga2 at gmail.com>
> ---
>
> Changes in v2:
> - Remove fences after amoswaps
> - Reword commit message
>
>  arch/riscv/cpu/start.S | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
>

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