* [PATCH] powerpc/fadump: invoke ibm,os-term with rtas_call_unlocked()
@ 2023-06-09 5:18 Hari Bathini
2023-06-09 5:33 ` Mahesh J Salgaonkar
0 siblings, 1 reply; 3+ messages in thread
From: Hari Bathini @ 2023-06-09 5:18 UTC (permalink / raw)
To: Michael Ellerman; +Cc: linuxppc-dev, Mahesh J Salgaonkar, Sourabh Jain
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 <hbathini@linux.ibm.com>
---
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 c087eeee320f..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(&args, token, 1, 1, NULL, __pa(rtas_os_term_buf));
} while (rtas_busy_delay_time(status));
if (status != 0)
--
2.40.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] powerpc/fadump: invoke ibm,os-term with rtas_call_unlocked()
2023-06-09 5:18 [PATCH] powerpc/fadump: invoke ibm,os-term with rtas_call_unlocked() Hari Bathini
@ 2023-06-09 5:33 ` Mahesh J Salgaonkar
2023-06-09 6:51 ` Hari Bathini
0 siblings, 1 reply; 3+ messages in thread
From: Mahesh J Salgaonkar @ 2023-06-09 5:33 UTC (permalink / raw)
To: Hari Bathini; +Cc: linuxppc-dev, Sourabh Jain
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 <hbathini@linux.ibm.com>
> ---
> 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 c087eeee320f..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(&args, 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
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] powerpc/fadump: invoke ibm,os-term with rtas_call_unlocked()
2023-06-09 5:33 ` Mahesh J Salgaonkar
@ 2023-06-09 6:51 ` Hari Bathini
0 siblings, 0 replies; 3+ messages in thread
From: Hari Bathini @ 2023-06-09 6:51 UTC (permalink / raw)
To: mahesh; +Cc: linuxppc-dev, Sourabh Jain
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 <hbathini@linux.ibm.com>
>> ---
>> 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 c087eeee320f..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(&args, 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
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-06-09 5:18 [PATCH] powerpc/fadump: invoke ibm,os-term with rtas_call_unlocked() Hari Bathini
2023-06-09 5:33 ` Mahesh J Salgaonkar
2023-06-09 6:51 ` Hari Bathini
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