diff mbox series

[v2,6/8] RISC-V: Add required checks during clock source init

Message ID 1546940318-9752-7-git-send-email-atish.patra@wdc.com (mailing list archive)
State New, archived
Headers show
Series Various SMP related fixes | expand

Commit Message

Atish Patra Jan. 8, 2019, 9:38 a.m. UTC
Currently, clocksource registration happens for an invalid cpu
for non-smp kernels. This lead to kernel panic as cpu hotplug
registration will fail for those cpus. Moreover,
riscv_hartid_to_cpuid can return errors now.

Do not proceed if hartid or cpuid is invalid. Take this opprtunity
to print appropriate error strings for different failure cases.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 drivers/clocksource/timer-riscv.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

Comments

Anup Patel Jan. 8, 2019, 11:56 a.m. UTC | #1
Few nit changes..

Prefer, "clocksource/drivers/riscv:" prefix instead of "RISC-V:" for
this patch.

On Tue, Jan 8, 2019 at 3:08 PM Atish Patra <atish.patra@wdc.com> wrote:
>
> Currently, clocksource registration happens for an invalid cpu
> for non-smp kernels. This lead to kernel panic as cpu hotplug
> registration will fail for those cpus. Moreover,
> riscv_hartid_to_cpuid can return errors now.
>
> Do not proceed if hartid or cpuid is invalid. Take this opprtunity
> to print appropriate error strings for different failure cases.
>
> Signed-off-by: Atish Patra <atish.patra@wdc.com>
> ---
>  drivers/clocksource/timer-riscv.c | 23 ++++++++++++++++++++---
>  1 file changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
> index 43189220..d9b914e9 100644
> --- a/drivers/clocksource/timer-riscv.c
> +++ b/drivers/clocksource/timer-riscv.c
> @@ -95,14 +95,31 @@ static int __init riscv_timer_init_dt(struct device_node *n)
>         struct clocksource *cs;
>
>         hartid = riscv_of_processor_hartid(n);
> +       if (hartid < 0) {
> +               pr_warn("Not valid hartid for node [%pOF] error = [%d]\n",
> +                       n, hartid);
> +               return hartid;
> +       }

Add empty line here.

>         cpuid = riscv_hartid_to_cpuid(hartid);
>

Remove empty line here

> +       if (cpuid < 0) {
> +               pr_warn("Invalid cpuid for hartid [%d]\n", hartid);
> +               return cpuid;
> +       }
> +
>         if (cpuid != smp_processor_id())
>                 return 0;
>
> +       pr_err("%s: Registering clocksource cpuid [%d] hartid [%d]\n",
> +              __func__, cpuid, hartid);
>         cs = per_cpu_ptr(&riscv_clocksource, cpuid);
> -       clocksource_register_hz(cs, riscv_timebase);
> +       error = clocksource_register_hz(cs, riscv_timebase);
>

Remove empty line here.

> +       if (error) {
> +               pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
> +                      error, cpuid);
> +               return error;
> +       }

Add empty line here.

>         sched_clock_register(riscv_sched_clock,
>                         BITS_PER_LONG, riscv_timebase);
>
> @@ -110,8 +127,8 @@ static int __init riscv_timer_init_dt(struct device_node *n)
>                          "clockevents/riscv/timer:starting",
>                          riscv_timer_starting_cpu, riscv_timer_dying_cpu);
>         if (error)
> -               pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
> -                      error, cpuid);
> +               pr_err("cpu hp setup state failed for RISCV timer [%d]\n",
> +                      error);
>         return error;
>  }
>
> --
> 2.7.4
>

Apart from above, looks good to me.

Reviewed-by: Anup Patel <anup@brainfault.org>

Regards,
Anup
Christoph Hellwig Jan. 15, 2019, 1:54 p.m. UTC | #2
>  	hartid = riscv_of_processor_hartid(n);
> +	if (hartid < 0) {
> +		pr_warn("Not valid hartid for node [%pOF] error = [%d]\n",
> +			n, hartid);
> +		return hartid;
> +	}
>  	cpuid = riscv_hartid_to_cpuid(hartid);
>  
> +	if (cpuid < 0) {
> +		pr_warn("Invalid cpuid for hartid [%d]\n", hartid);
> +		return cpuid;
> +	}
> +

No need for the empty line after the riscv_hartid_to_cpuid call.

> -	clocksource_register_hz(cs, riscv_timebase);
> +	error = clocksource_register_hz(cs, riscv_timebase);
>  
> +	if (error) {

Same here.
Atish Patra Jan. 18, 2019, 2:10 a.m. UTC | #3
On 1/8/19 3:57 AM, Anup Patel wrote:
> Few nit changes..
> 
> Prefer, "clocksource/drivers/riscv:" prefix instead of "RISC-V:" for
> this patch.
> 
> On Tue, Jan 8, 2019 at 3:08 PM Atish Patra <atish.patra@wdc.com> wrote:
>>
>> Currently, clocksource registration happens for an invalid cpu
>> for non-smp kernels. This lead to kernel panic as cpu hotplug
>> registration will fail for those cpus. Moreover,
>> riscv_hartid_to_cpuid can return errors now.
>>
>> Do not proceed if hartid or cpuid is invalid. Take this opprtunity
>> to print appropriate error strings for different failure cases.
>>
>> Signed-off-by: Atish Patra <atish.patra@wdc.com>
>> ---
>>   drivers/clocksource/timer-riscv.c | 23 ++++++++++++++++++++---
>>   1 file changed, 20 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
>> index 43189220..d9b914e9 100644
>> --- a/drivers/clocksource/timer-riscv.c
>> +++ b/drivers/clocksource/timer-riscv.c
>> @@ -95,14 +95,31 @@ static int __init riscv_timer_init_dt(struct device_node *n)
>>          struct clocksource *cs;
>>
>>          hartid = riscv_of_processor_hartid(n);
>> +       if (hartid < 0) {
>> +               pr_warn("Not valid hartid for node [%pOF] error = [%d]\n",
>> +                       n, hartid);
>> +               return hartid;
>> +       }
> 
> Add empty line here.
> 
>>          cpuid = riscv_hartid_to_cpuid(hartid);
>>
> 
> Remove empty line here
> 
>> +       if (cpuid < 0) {
>> +               pr_warn("Invalid cpuid for hartid [%d]\n", hartid);
>> +               return cpuid;
>> +       }
>> +
>>          if (cpuid != smp_processor_id())
>>                  return 0;
>>
>> +       pr_err("%s: Registering clocksource cpuid [%d] hartid [%d]\n",
>> +              __func__, cpuid, hartid);
>>          cs = per_cpu_ptr(&riscv_clocksource, cpuid);
>> -       clocksource_register_hz(cs, riscv_timebase);
>> +       error = clocksource_register_hz(cs, riscv_timebase);
>>
> 
> Remove empty line here.
> 
>> +       if (error) {
>> +               pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
>> +                      error, cpuid);
>> +               return error;
>> +       }
> 
> Add empty line here.
> 
>>          sched_clock_register(riscv_sched_clock,
>>                          BITS_PER_LONG, riscv_timebase);
>>
>> @@ -110,8 +127,8 @@ static int __init riscv_timer_init_dt(struct device_node *n)
>>                           "clockevents/riscv/timer:starting",
>>                           riscv_timer_starting_cpu, riscv_timer_dying_cpu);
>>          if (error)
>> -               pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
>> -                      error, cpuid);
>> +               pr_err("cpu hp setup state failed for RISCV timer [%d]\n",
>> +                      error);
>>          return error;
>>   }
>>
>> --
>> 2.7.4
>>
> 
> Apart from above, looks good to me.
> 
> Reviewed-by: Anup Patel <anup@brainfault.org>
>

Thanks for the review. I will fix the empty line issues and subject line.


> Regards,
> Anup
>
diff mbox series

Patch

diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index 43189220..d9b914e9 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -95,14 +95,31 @@  static int __init riscv_timer_init_dt(struct device_node *n)
 	struct clocksource *cs;
 
 	hartid = riscv_of_processor_hartid(n);
+	if (hartid < 0) {
+		pr_warn("Not valid hartid for node [%pOF] error = [%d]\n",
+			n, hartid);
+		return hartid;
+	}
 	cpuid = riscv_hartid_to_cpuid(hartid);
 
+	if (cpuid < 0) {
+		pr_warn("Invalid cpuid for hartid [%d]\n", hartid);
+		return cpuid;
+	}
+
 	if (cpuid != smp_processor_id())
 		return 0;
 
+	pr_err("%s: Registering clocksource cpuid [%d] hartid [%d]\n",
+	       __func__, cpuid, hartid);
 	cs = per_cpu_ptr(&riscv_clocksource, cpuid);
-	clocksource_register_hz(cs, riscv_timebase);
+	error = clocksource_register_hz(cs, riscv_timebase);
 
+	if (error) {
+		pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
+		       error, cpuid);
+		return error;
+	}
 	sched_clock_register(riscv_sched_clock,
 			BITS_PER_LONG, riscv_timebase);
 
@@ -110,8 +127,8 @@  static int __init riscv_timer_init_dt(struct device_node *n)
 			 "clockevents/riscv/timer:starting",
 			 riscv_timer_starting_cpu, riscv_timer_dying_cpu);
 	if (error)
-		pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
-		       error, cpuid);
+		pr_err("cpu hp setup state failed for RISCV timer [%d]\n",
+		       error);
 	return error;
 }