diff mbox series

[v10,17/19] arm64: Kconfig: Enable hotplug CPU on arm64 if ACPI_PROCESSOR is enabled.

Message ID 20240529133446.28446-18-Jonathan.Cameron@huawei.com (mailing list archive)
State Handled Elsewhere, archived
Headers show
Series ACPI/arm64: add support for virtual cpu hotplug | expand

Commit Message

Jonathan Cameron May 29, 2024, 1:34 p.m. UTC 
In order to move arch_register_cpu() to be called via the same path
for initially present CPUs described by ACPI and hotplugged CPUs
ACPI_HOTPLUG_CPU needs to be enabled.

The protection against invalid IDs in acpi_map_cpu() is needed as
at least one production BIOS is in the wild which reports entries
in DSDT (with no _STA method, so assumed enabled and present)
that don't match MADT.

Tested-by: Miguel Luis <miguel.luis@oracle.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 arch/arm64/Kconfig       |  1 +
 arch/arm64/kernel/acpi.c | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

Comments

Gavin Shan June 30, 2024, 12:39 a.m. UTC | #1 
Hi Jonathan and Catalin,

On 5/29/24 11:34 PM, Jonathan Cameron wrote:
> In order to move arch_register_cpu() to be called via the same path
> for initially present CPUs described by ACPI and hotplugged CPUs
> ACPI_HOTPLUG_CPU needs to be enabled.
> 
> The protection against invalid IDs in acpi_map_cpu() is needed as
> at least one production BIOS is in the wild which reports entries
> in DSDT (with no _STA method, so assumed enabled and present)
> that don't match MADT.
> 
> Tested-by: Miguel Luis <miguel.luis@oracle.com>
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---
>   arch/arm64/Kconfig       |  1 +
>   arch/arm64/kernel/acpi.c | 22 ++++++++++++++++++++++
>   2 files changed, 23 insertions(+)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 5d91259ee7b5..e8f2ef2312db 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -5,6 +5,7 @@ config ARM64
>   	select ACPI_CCA_REQUIRED if ACPI
>   	select ACPI_GENERIC_GSI if ACPI
>   	select ACPI_GTDT if ACPI
> +	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR

ACPI_HOTPLUG_CPU depends on (ACPI_PROCESSOR && HOTPLUG_CPU). It needs to be:

	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU

Otherwise, we can have compiling error with the following configurations.

CONFIG_ACPI_PROCESSOR=y
CONFIG_HOTPLUG_CPU=n
CONFIG_ACPI_HOTPLUG_CPU=y

arch/arm64/kernel/smp.c: In function ‘arch_unregister_cpu’:
arch/arm64/kernel/smp.c:563:9: error: implicit declaration of function ‘unregister_cpu’; did you mean ‘register_cpu’? [-Werror=implicit-function-declaration]
   563 |         unregister_cpu(c);
       |         ^~~~~~~~~~~~~~
       |         register_cpu

Since the series has been queued to Catalin's "for-next/vcpu-hotplug" branch, I
guess the easiest way would be to fix it in place with Catalin's help.

Thanks,
Gavin

>   	select ACPI_IORT if ACPI
>   	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
>   	select ACPI_MCFG if (ACPI && PCI)
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index e0e7b93c16cc..9360ba86678b 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -30,6 +30,7 @@
>   #include <linux/pgtable.h>
>   
>   #include <acpi/ghes.h>
> +#include <acpi/processor.h>
>   #include <asm/cputype.h>
>   #include <asm/cpu_ops.h>
>   #include <asm/daifflags.h>
> @@ -423,6 +424,27 @@ void arch_reserve_mem_area(acpi_physical_address addr, size_t size)
>   	memblock_mark_nomap(addr, size);
>   }
>   
> +#ifdef CONFIG_ACPI_HOTPLUG_CPU
> +int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 apci_id,
> +		 int *pcpu)
> +{
> +	/* If an error code is passed in this stub can't fix it */
> +	if (*pcpu < 0) {
> +		pr_warn_once("Unable to map CPU to valid ID\n");
> +		return *pcpu;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(acpi_map_cpu);
> +
> +int acpi_unmap_cpu(int cpu)
> +{
> +	return 0;
> +}
> +EXPORT_SYMBOL(acpi_unmap_cpu);
> +#endif /* CONFIG_ACPI_HOTPLUG_CPU */
> +
>   #ifdef CONFIG_ACPI_FFH
>   /*
>    * Implements ARM64 specific callbacks to support ACPI FFH Operation Region as
Catalin Marinas June 30, 2024, 9:26 a.m. UTC | #2 
Hi Gavin,

On Sun, Jun 30, 2024 at 10:39:04AM +1000, Gavin Shan wrote:
> On 5/29/24 11:34 PM, Jonathan Cameron wrote:
> > In order to move arch_register_cpu() to be called via the same path
> > for initially present CPUs described by ACPI and hotplugged CPUs
> > ACPI_HOTPLUG_CPU needs to be enabled.
> > 
> > The protection against invalid IDs in acpi_map_cpu() is needed as
> > at least one production BIOS is in the wild which reports entries
> > in DSDT (with no _STA method, so assumed enabled and present)
> > that don't match MADT.
> > 
> > Tested-by: Miguel Luis <miguel.luis@oracle.com>
> > Reviewed-by: Gavin Shan <gshan@redhat.com>
> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > ---
> >   arch/arm64/Kconfig       |  1 +
> >   arch/arm64/kernel/acpi.c | 22 ++++++++++++++++++++++
> >   2 files changed, 23 insertions(+)
> > 
> > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > index 5d91259ee7b5..e8f2ef2312db 100644
> > --- a/arch/arm64/Kconfig
> > +++ b/arch/arm64/Kconfig
> > @@ -5,6 +5,7 @@ config ARM64
> >   	select ACPI_CCA_REQUIRED if ACPI
> >   	select ACPI_GENERIC_GSI if ACPI
> >   	select ACPI_GTDT if ACPI
> > +	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR
> 
> ACPI_HOTPLUG_CPU depends on (ACPI_PROCESSOR && HOTPLUG_CPU). It needs to be:
> 
> 	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
> 
> Otherwise, we can have compiling error with the following configurations.
> 
> CONFIG_ACPI_PROCESSOR=y
> CONFIG_HOTPLUG_CPU=n
> CONFIG_ACPI_HOTPLUG_CPU=y
> 
> arch/arm64/kernel/smp.c: In function ‘arch_unregister_cpu’:
> arch/arm64/kernel/smp.c:563:9: error: implicit declaration of function ‘unregister_cpu’; did you mean ‘register_cpu’? [-Werror=implicit-function-declaration]
>   563 |         unregister_cpu(c);
>       |         ^~~~~~~~~~~~~~
>       |         register_cpu

Ah, I thought that in addition to the warning for unmet dependencies,
kbuild would also leave the option off. I need to add SUSPEND=n and
HIBERNATE=n to my build scripts.

The fix matches what x86 does, so I'm ok with it.

> Since the series has been queued to Catalin's "for-next/vcpu-hotplug" branch, I
> guess the easiest way would be to fix it in place with Catalin's help.

I wasn't planning to rebase the branch unless there's something major.
Since the doesn't happen with defconfig, it's doesn't affect bisection
that much, so my preference would be for a fix on top of this branch
(and with a Fixes: tag since the branch is stable).

Thanks.
Gavin Shan July 1, 2024, 12:17 a.m. UTC | #3 
Hi Catalin,

On 6/30/24 7:26 PM, Catalin Marinas wrote:
> On Sun, Jun 30, 2024 at 10:39:04AM +1000, Gavin Shan wrote:
>> On 5/29/24 11:34 PM, Jonathan Cameron wrote:
>>> In order to move arch_register_cpu() to be called via the same path
>>> for initially present CPUs described by ACPI and hotplugged CPUs
>>> ACPI_HOTPLUG_CPU needs to be enabled.
>>>
>>> The protection against invalid IDs in acpi_map_cpu() is needed as
>>> at least one production BIOS is in the wild which reports entries
>>> in DSDT (with no _STA method, so assumed enabled and present)
>>> that don't match MADT.
>>>
>>> Tested-by: Miguel Luis <miguel.luis@oracle.com>
>>> Reviewed-by: Gavin Shan <gshan@redhat.com>
>>> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>>> ---
>>>    arch/arm64/Kconfig       |  1 +
>>>    arch/arm64/kernel/acpi.c | 22 ++++++++++++++++++++++
>>>    2 files changed, 23 insertions(+)
>>>
>>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>>> index 5d91259ee7b5..e8f2ef2312db 100644
>>> --- a/arch/arm64/Kconfig
>>> +++ b/arch/arm64/Kconfig
>>> @@ -5,6 +5,7 @@ config ARM64
>>>    	select ACPI_CCA_REQUIRED if ACPI
>>>    	select ACPI_GENERIC_GSI if ACPI
>>>    	select ACPI_GTDT if ACPI
>>> +	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR
>>
>> ACPI_HOTPLUG_CPU depends on (ACPI_PROCESSOR && HOTPLUG_CPU). It needs to be:
>>
>> 	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
>>
>> Otherwise, we can have compiling error with the following configurations.
>>
>> CONFIG_ACPI_PROCESSOR=y
>> CONFIG_HOTPLUG_CPU=n
>> CONFIG_ACPI_HOTPLUG_CPU=y
>>
>> arch/arm64/kernel/smp.c: In function ‘arch_unregister_cpu’:
>> arch/arm64/kernel/smp.c:563:9: error: implicit declaration of function ‘unregister_cpu’; did you mean ‘register_cpu’? [-Werror=implicit-function-declaration]
>>    563 |         unregister_cpu(c);
>>        |         ^~~~~~~~~~~~~~
>>        |         register_cpu
> 
> Ah, I thought that in addition to the warning for unmet dependencies,
> kbuild would also leave the option off. I need to add SUSPEND=n and
> HIBERNATE=n to my build scripts.
> 
> The fix matches what x86 does, so I'm ok with it.
> 

Ok, thanks for your confirm.

>> Since the series has been queued to Catalin's "for-next/vcpu-hotplug" branch, I
>> guess the easiest way would be to fix it in place with Catalin's help.
> 
> I wasn't planning to rebase the branch unless there's something major.
> Since the doesn't happen with defconfig, it's doesn't affect bisection
> that much, so my preference would be for a fix on top of this branch
> (and with a Fixes: tag since the branch is stable).
> 

Sure, I've posted a fix, applicable to branch 'for-next/vcpu-hotplug'.

https://lists.infradead.org/pipermail/linux-arm-kernel/2024-June/939690.html

Thanks,
Gavin
diff mbox series

Patch

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 5d91259ee7b5..e8f2ef2312db 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -5,6 +5,7 @@  config ARM64
 	select ACPI_CCA_REQUIRED if ACPI
 	select ACPI_GENERIC_GSI if ACPI
 	select ACPI_GTDT if ACPI
+	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR
 	select ACPI_IORT if ACPI
 	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
 	select ACPI_MCFG if (ACPI && PCI)
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index e0e7b93c16cc..9360ba86678b 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -30,6 +30,7 @@ 
 #include <linux/pgtable.h>
 
 #include <acpi/ghes.h>
+#include <acpi/processor.h>
 #include <asm/cputype.h>
 #include <asm/cpu_ops.h>
 #include <asm/daifflags.h>
@@ -423,6 +424,27 @@  void arch_reserve_mem_area(acpi_physical_address addr, size_t size)
 	memblock_mark_nomap(addr, size);
 }
 
+#ifdef CONFIG_ACPI_HOTPLUG_CPU
+int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 apci_id,
+		 int *pcpu)
+{
+	/* If an error code is passed in this stub can't fix it */
+	if (*pcpu < 0) {
+		pr_warn_once("Unable to map CPU to valid ID\n");
+		return *pcpu;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(acpi_map_cpu);
+
+int acpi_unmap_cpu(int cpu)
+{
+	return 0;
+}
+EXPORT_SYMBOL(acpi_unmap_cpu);
+#endif /* CONFIG_ACPI_HOTPLUG_CPU */
+
 #ifdef CONFIG_ACPI_FFH
 /*
  * Implements ARM64 specific callbacks to support ACPI FFH Operation Region as