[v4,1/5] arm64: Declare ACPI parking protocol CPU operation if needed
diff mbox series

Message ID 20200226002356.86986-2-gshan@redhat.com
State New
Headers show
Series
  • arm64: Dereference CPU operations indirectly
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Commit Message

Gavin Shan Feb. 26, 2020, 12:23 a.m. UTC
It's obvious we needn't declare the corresponding CPU operation when
CONFIG_ARM64_ACPI_PARKING_PROTOCOL is disabled.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 arch/arm64/kernel/cpu_ops.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Mark Rutland March 17, 2020, 10:28 a.m. UTC | #1
On Wed, Feb 26, 2020 at 11:23:52AM +1100, Gavin Shan wrote:
> It's obvious we needn't declare the corresponding CPU operation when
> CONFIG_ARM64_ACPI_PARKING_PROTOCOL is disabled.
> 
> Signed-off-by: Gavin Shan <gshan@redhat.com>

Is there a problem leaving this as-is, e.g. a compiler warning? If so,
it'd be nice to mention that in the commit message.

We don't always bother placing declartions under ifdefs where the use
would result in a link-time error.

No strong feelings form me either way, so FWIW:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Mark.

> ---
>  arch/arm64/kernel/cpu_ops.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
> index 7e07072757af..2082cfb1be86 100644
> --- a/arch/arm64/kernel/cpu_ops.c
> +++ b/arch/arm64/kernel/cpu_ops.c
> @@ -15,7 +15,9 @@
>  #include <asm/smp_plat.h>
>  
>  extern const struct cpu_operations smp_spin_table_ops;
> +#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
>  extern const struct cpu_operations acpi_parking_protocol_ops;
> +#endif
>  extern const struct cpu_operations cpu_psci_ops;
>  
>  const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
> -- 
> 2.23.0
>
Gavin Shan March 18, 2020, 2:06 a.m. UTC | #2
On 3/17/20 9:28 PM, Mark Rutland wrote:
> On Wed, Feb 26, 2020 at 11:23:52AM +1100, Gavin Shan wrote:
>> It's obvious we needn't declare the corresponding CPU operation when
>> CONFIG_ARM64_ACPI_PARKING_PROTOCOL is disabled.
>>
>> Signed-off-by: Gavin Shan <gshan@redhat.com>
> 
> Is there a problem leaving this as-is, e.g. a compiler warning? If so,
> it'd be nice to mention that in the commit message.
> 
> We don't always bother placing declartions under ifdefs where the use
> would result in a link-time error.
> 
> No strong feelings form me either way, so FWIW:
> 
> Acked-by: Mark Rutland <mark.rutland@arm.com>
> 
> Mark.
> 

It doesn't cause a compiler warning because the corresponding CPU operations
is declared as "extern". I will have commit log in next revision as below:

It's obvious we needn't declare the corresponding CPU operation when
CONFIG_ARM64_ACPI_PARKING_PROTOCOL is disabled, even it doesn't cause
any compiling warnings.

Thanks,
Gavin

>> ---
>>   arch/arm64/kernel/cpu_ops.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
>> index 7e07072757af..2082cfb1be86 100644
>> --- a/arch/arm64/kernel/cpu_ops.c
>> +++ b/arch/arm64/kernel/cpu_ops.c
>> @@ -15,7 +15,9 @@
>>   #include <asm/smp_plat.h>
>>   
>>   extern const struct cpu_operations smp_spin_table_ops;
>> +#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
>>   extern const struct cpu_operations acpi_parking_protocol_ops;
>> +#endif
>>   extern const struct cpu_operations cpu_psci_ops;
>>   
>>   const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
>> -- 
>> 2.23.0
>>
>

Patch
diff mbox series

diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
index 7e07072757af..2082cfb1be86 100644
--- a/arch/arm64/kernel/cpu_ops.c
+++ b/arch/arm64/kernel/cpu_ops.c
@@ -15,7 +15,9 @@ 
 #include <asm/smp_plat.h>
 
 extern const struct cpu_operations smp_spin_table_ops;
+#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
 extern const struct cpu_operations acpi_parking_protocol_ops;
+#endif
 extern const struct cpu_operations cpu_psci_ops;
 
 const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;