2021-10-19 02:35:50

by Li, Meng

[permalink] [raw]
Subject: [PATCH v2] soc: fsl: dpio: instead smp_processor_id with raw_smp_processor_id

From: Meng Li <[email protected]>

When enable debug kernel configs,there will be calltrace as below:

BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
caller is debug_smp_processor_id+0x20/0x30
CPU: 6 PID: 1 Comm: swapper/0 Not tainted 5.10.63-yocto-standard #1
Hardware name: NXP Layerscape LX2160ARDB (DT)
Call trace:
dump_backtrace+0x0/0x1a0
show_stack+0x24/0x30
dump_stack+0xf0/0x13c
check_preemption_disabled+0x100/0x110
debug_smp_processor_id+0x20/0x30
dpaa2_io_query_fq_count+0xdc/0x154
dpaa2_eth_stop+0x144/0x314
__dev_close_many+0xdc/0x160
__dev_change_flags+0xe8/0x220
dev_change_flags+0x30/0x70
ic_close_devs+0x50/0x78
ip_auto_config+0xed0/0xf10
do_one_initcall+0xac/0x460
kernel_init_freeable+0x30c/0x378
kernel_init+0x20/0x128
ret_from_fork+0x10/0x38

Based on comment in the context, it doesn't matter whether
preemption is disable or not. So, instead smp_processor_id()
with raw_smp_processor_id() to avoid above call trace.

v2:
Remove the preempt_disable/enable() protection, instead smp_processor_id
with raw_smp_processor_id.

Fixes: c89105c9b390 ("staging: fsl-mc: Move DPIO from staging to drivers/soc/fsl")
Cc: [email protected]
Signed-off-by: Meng Li <[email protected]>
---
drivers/soc/fsl/dpio/dpio-service.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/fsl/dpio/dpio-service.c b/drivers/soc/fsl/dpio/dpio-service.c
index 19f47ea9dab0..3050a534d42c 100644
--- a/drivers/soc/fsl/dpio/dpio-service.c
+++ b/drivers/soc/fsl/dpio/dpio-service.c
@@ -59,7 +59,7 @@ static inline struct dpaa2_io *service_select_by_cpu(struct dpaa2_io *d,
* potentially being migrated away.
*/
if (cpu < 0)
- cpu = smp_processor_id();
+ cpu = raw_smp_processor_id();

/* If a specific cpu was requested, pick it up immediately */
return dpio_by_cpu[cpu];
--
2.17.1


2021-10-20 01:40:33

by Leo Li

[permalink] [raw]
Subject: Re: [PATCH v2] soc: fsl: dpio: instead smp_processor_id with raw_smp_processor_id

On Mon, Oct 18, 2021 at 9:46 PM <[email protected]> wrote:
>
> From: Meng Li <[email protected]>
>
> When enable debug kernel configs,there will be calltrace as below:
>
> BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
> caller is debug_smp_processor_id+0x20/0x30
> CPU: 6 PID: 1 Comm: swapper/0 Not tainted 5.10.63-yocto-standard #1
> Hardware name: NXP Layerscape LX2160ARDB (DT)
> Call trace:
> dump_backtrace+0x0/0x1a0
> show_stack+0x24/0x30
> dump_stack+0xf0/0x13c
> check_preemption_disabled+0x100/0x110
> debug_smp_processor_id+0x20/0x30
> dpaa2_io_query_fq_count+0xdc/0x154
> dpaa2_eth_stop+0x144/0x314
> __dev_close_many+0xdc/0x160
> __dev_change_flags+0xe8/0x220
> dev_change_flags+0x30/0x70
> ic_close_devs+0x50/0x78
> ip_auto_config+0xed0/0xf10
> do_one_initcall+0xac/0x460
> kernel_init_freeable+0x30c/0x378
> kernel_init+0x20/0x128
> ret_from_fork+0x10/0x38
>
> Based on comment in the context, it doesn't matter whether
> preemption is disable or not. So, instead smp_processor_id()

s/instead/replace/g

> with raw_smp_processor_id() to avoid above call trace.
>
> v2:
> Remove the preempt_disable/enable() protection, instead smp_processor_id
> with raw_smp_processor_id.

The revision history information should go after the "---" below.

>
> Fixes: c89105c9b390 ("staging: fsl-mc: Move DPIO from staging to drivers/soc/fsl")
> Cc: [email protected]
> Signed-off-by: Meng Li <[email protected]>

I helped to fix the issues I mentioned. Applied for fix. Thanks.

> ---
> drivers/soc/fsl/dpio/dpio-service.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/soc/fsl/dpio/dpio-service.c b/drivers/soc/fsl/dpio/dpio-service.c
> index 19f47ea9dab0..3050a534d42c 100644
> --- a/drivers/soc/fsl/dpio/dpio-service.c
> +++ b/drivers/soc/fsl/dpio/dpio-service.c
> @@ -59,7 +59,7 @@ static inline struct dpaa2_io *service_select_by_cpu(struct dpaa2_io *d,
> * potentially being migrated away.
> */
> if (cpu < 0)
> - cpu = smp_processor_id();
> + cpu = raw_smp_processor_id();
>
> /* If a specific cpu was requested, pick it up immediately */
> return dpio_by_cpu[cpu];
> --
> 2.17.1
>