Re: [PATCH v2] powerpc/fadump: invoke ibm,os-term with rtas_call_unlocked()

[Mahesh J Salgaonkar]

On 2023-06-09 12:44:04 Fri, Hari Bathini wrote:
> Invoke ibm,os-term call with rtas_call_unlocked(), without using the
> RTAS spinlock, to avoid deadlock in the unlikely event of a machine
> crash while making an RTAS call.
> 
> Signed-off-by: Hari Bathini <hbath...@linux.ibm.com>
> ---
>  arch/powerpc/kernel/rtas.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
> index c087eeee320f..a8192e5b1a5f 100644
> --- a/arch/powerpc/kernel/rtas.c
> +++ b/arch/powerpc/kernel/rtas.c
> @@ -1587,6 +1587,7 @@ static bool ibm_extended_os_term;
>  void rtas_os_term(char *str)
>  {
>       s32 token = rtas_function_token(RTAS_FN_IBM_OS_TERM);
> +     static struct rtas_args args;
>       int status;
>  
>       /*
> @@ -1607,7 +1608,8 @@ void rtas_os_term(char *str)
>        * schedules.
>        */
>       do {
> -             status = rtas_call(token, 1, 1, NULL, __pa(rtas_os_term_buf));
> +             rtas_call_unlocked(&args, token, 1, 1, NULL, 
> __pa(rtas_os_term_buf));
> +             status = be32_to_cpu(args.rets[0]);

Looks good to me.

Reviewed-by: Mahesh Salgaonkar <mah...@linux.ibm.com>

>       } while (rtas_busy_delay_time(status));

Thanks,
-Mahesh.