[PATCH RESEND 0/2] ARM: Switch over to GENERIC_CPU_DEVICES

[PATCH RESEND 0/2] ARM: Switch over to GENERIC_CPU_DEVICES

[Jinjie Ruan]

Currently, almost all architectures have switched to GENERIC_CPU_DEVICES,
except for arm32. Also switch over to GENERIC_CPU_DEVICES, which can also
make the code more concise.

Jinjie Ruan (2):
  ARM: Switch over to GENERIC_CPU_DEVICES using arch_register_cpu()
  ARM: Convert to arch_cpu_is_hotpluggable()

 arch/arm/Kconfig           |  1 +
 arch/arm/include/asm/cpu.h |  1 -
 arch/arm/kernel/setup.c    | 14 ++------------
 3 files changed, 3 insertions(+), 13 deletions(-)

-- 
2.34.1

[PATCH RESEND 1/2] ARM: Switch over to GENERIC_CPU_DEVICES using arch_register_cpu()

[Jinjie Ruan]

Currently, almost all architectures have switched to GENERIC_CPU_DEVICES,
except for arm32. Also switch over to GENERIC_CPU_DEVICES, and provide an
arch_register_cpu() that populates the hotpluggable flag for arm32.

The struct cpu in struct cpuinfo_arm is never used directly, remove
it to use the one GENERIC_CPU_DEVICES provides.

This also has the effect of moving the registration of CPUs from subsys to
driver core initialisation, prior to any initcalls running.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 arch/arm/Kconfig           |  1 +
 arch/arm/include/asm/cpu.h |  1 -
 arch/arm/kernel/setup.c    | 15 ++++-----------
 3 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b211b7f5a138..68990e1645d5 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -63,6 +63,7 @@ config ARM
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
 	select GENERIC_IRQ_IPI if SMP
 	select GENERIC_CPU_AUTOPROBE
+	select GENERIC_CPU_DEVICES
 	select GENERIC_EARLY_IOREMAP
 	select GENERIC_IDLE_POLL_SETUP
 	select GENERIC_IRQ_MULTI_HANDLER
diff --git a/arch/arm/include/asm/cpu.h b/arch/arm/include/asm/cpu.h
index bd6fdb4b922d..9d8863537aa5 100644
--- a/arch/arm/include/asm/cpu.h
+++ b/arch/arm/include/asm/cpu.h
@@ -11,7 +11,6 @@
 #include <linux/cpu.h>
 
 struct cpuinfo_arm {
-	struct cpu	cpu;
 	u32		cpuid;
 #ifdef CONFIG_SMP
 	unsigned int	loops_per_jiffy;
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 7b33b157fca0..f91e2b5b8b20 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1201,20 +1201,13 @@ void __init setup_arch(char **cmdline_p)
 		mdesc->init_early();
 }
 
-
-static int __init topology_init(void)
+int arch_register_cpu(int num)
 {
-	int cpu;
-
-	for_each_possible_cpu(cpu) {
-		struct cpuinfo_arm *cpuinfo = &per_cpu(cpu_data, cpu);
-		cpuinfo->cpu.hotpluggable = platform_can_hotplug_cpu(cpu);
-		register_cpu(&cpuinfo->cpu, cpu);
-	}
+	struct cpu *cpu = &per_cpu(cpu_devices, num);
 
-	return 0;
+	cpu->hotpluggable = platform_can_hotplug_cpu(num);
+	return register_cpu(cpu, num);
 }
-subsys_initcall(topology_init);
 
 #ifdef CONFIG_HAVE_PROC_CPU
 static int __init proc_cpu_init(void)
-- 
2.34.1

[PATCH RESEND 2/2] ARM: Convert to arch_cpu_is_hotpluggable()

[Jinjie Ruan]

Convert arm32 to use the arch_cpu_is_hotpluggable() helper rather than
arch_register_cpu().

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 arch/arm/kernel/setup.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index f91e2b5b8b20..e6a857bf0ce6 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1201,12 +1201,9 @@ void __init setup_arch(char **cmdline_p)
 		mdesc->init_early();
 }
 
-int arch_register_cpu(int num)
+bool arch_cpu_is_hotpluggable(int num)
 {
-	struct cpu *cpu = &per_cpu(cpu_devices, num);
-
-	cpu->hotpluggable = platform_can_hotplug_cpu(num);
-	return register_cpu(cpu, num);
+	return platform_can_hotplug_cpu(num);
 }
 
 #ifdef CONFIG_HAVE_PROC_CPU
-- 
2.34.1

Re: [PATCH RESEND 0/2] ARM: Switch over to GENERIC_CPU_DEVICES

[Jinjie Ruan]

Gentle ping.

On 2024/7/2 15:57, Jinjie Ruan wrote:
> Currently, almost all architectures have switched to GENERIC_CPU_DEVICES,
> except for arm32. Also switch over to GENERIC_CPU_DEVICES, which can also
> make the code more concise.
> 
> Jinjie Ruan (2):
>   ARM: Switch over to GENERIC_CPU_DEVICES using arch_register_cpu()
>   ARM: Convert to arch_cpu_is_hotpluggable()
> 
>  arch/arm/Kconfig           |  1 +
>  arch/arm/include/asm/cpu.h |  1 -
>  arch/arm/kernel/setup.c    | 14 ++------------
>  3 files changed, 3 insertions(+), 13 deletions(-)
> 

Re: [PATCH RESEND 0/2] ARM: Switch over to GENERIC_CPU_DEVICES

[Russell King (Oracle)]

On Wed, Jul 31, 2024 at 09:52:07AM +0800, Jinjie Ruan wrote:
> On 2024/7/2 15:57, Jinjie Ruan wrote:
> > Currently, almost all architectures have switched to GENERIC_CPU_DEVICES,
> > except for arm32. Also switch over to GENERIC_CPU_DEVICES, which can also
> > make the code more concise.
> > 
> > Jinjie Ruan (2):
> >   ARM: Switch over to GENERIC_CPU_DEVICES using arch_register_cpu()
> >   ARM: Convert to arch_cpu_is_hotpluggable()
> > 
> >  arch/arm/Kconfig           |  1 +
> >  arch/arm/include/asm/cpu.h |  1 -
> >  arch/arm/kernel/setup.c    | 14 ++------------
> >  3 files changed, 3 insertions(+), 13 deletions(-)

I think it's fine, but it needs to end up in the patch system to be
applied. Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

Re: [PATCH RESEND 0/2] ARM: Switch over to GENERIC_CPU_DEVICES

[Jinjie Ruan]

On 2024/7/31 16:27, Russell King (Oracle) wrote:
> On Wed, Jul 31, 2024 at 09:52:07AM +0800, Jinjie Ruan wrote:
>> On 2024/7/2 15:57, Jinjie Ruan wrote:
>>> Currently, almost all architectures have switched to GENERIC_CPU_DEVICES,
>>> except for arm32. Also switch over to GENERIC_CPU_DEVICES, which can also
>>> make the code more concise.
>>>
>>> Jinjie Ruan (2):
>>>   ARM: Switch over to GENERIC_CPU_DEVICES using arch_register_cpu()
>>>   ARM: Convert to arch_cpu_is_hotpluggable()
>>>
>>>  arch/arm/Kconfig           |  1 +
>>>  arch/arm/include/asm/cpu.h |  1 -
>>>  arch/arm/kernel/setup.c    | 14 ++------------
>>>  3 files changed, 3 insertions(+), 13 deletions(-)
> 
> I think it's fine, but it needs to end up in the patch system to be
> applied. Thanks.

Hi, Russell

Thank you very much! I'll push it in rmk's patch tracker sooner.

>