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

[Hari Bathini]

On 09/06/23 11:03 am, Mahesh J Salgaonkar wrote:

On 2023-06-09 10:48:46 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.


Thanks for the patch. Minor comment bellow.



Signed-off-by: Hari Bathini 
---
  arch/powerpc/kernel/rtas.c | 3 ++-
  1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index c087320f..f65b2a8cc0f1 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 +1608,7 @@ void rtas_os_term(char *str)
 * schedules.
 */
do {
-   status = rtas_call(token, 1, 1, NULL, __pa(rtas_os_term_buf));
+   status = rtas_call_unlocked(, token, 1, 1, NULL, 
__pa(rtas_os_term_buf));


rtas_call_unlocked() returns void. You may want to extract the status
from args->rets[0].


Yeah, Mahesh. I posted a stale version. Will post the updated version.

Thanks
Hari

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

[Mahesh J Salgaonkar]

On 2023-06-09 10:48:46 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.

Thanks for the patch. Minor comment bellow.

> 
> Signed-off-by: Hari Bathini 
> ---
>  arch/powerpc/kernel/rtas.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
> index c087320f..f65b2a8cc0f1 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 +1608,7 @@ void rtas_os_term(char *str)
>* schedules.
>*/
>   do {
> - status = rtas_call(token, 1, 1, NULL, __pa(rtas_os_term_buf));
> + status = rtas_call_unlocked(, token, 1, 1, NULL, 
> __pa(rtas_os_term_buf));

rtas_call_unlocked() returns void. You may want to extract the status
from args->rets[0].

Thanks,
-Mahesh.

>   } while (rtas_busy_delay_time(status));
>  
>   if (status != 0)
> -- 
> 2.40.1
> 

-- 
Mahesh J Salgaonkar