cpu-hotplug: Provide prototypes for arch CPU registration

Provide common prototypes for arch_register_cpu() and
arch_unregister_cpu(). These are called by acpi_processor.c, with weak
versions, so the prototype for this is already set. It is generally not
necessary for function prototypes to be conditional on preprocessor macros.

Some architectures (e.g. Loongarch) are missing the prototype for this, and
rather than add it to Loongarch's asm/cpu.h, do the job once for everyone.

Since this covers everyone, remove the now unnecessary prototypes in
asm/cpu.h, and therefore remove the 'static' from one of ia64's
arch_register_cpu() definitions.

[ tglx: Bring back the ia64 part and remove the ACPI prototypes ]

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/E1qkoRr-0088Q8-Da@rmk-PC.armlinux.org.uk

7 files changed, 5 insertions, 14 deletions

diff --git a/arch/ia64/include/asm/cpu.h b/arch/ia64/include/asm/cpu.h
index db125df9e08882..642d71675ddb29 100644
--- a/arch/ia64/include/asm/cpu.h
+++ b/arch/ia64/include/asm/cpu.h
@@ -15,9 +15,4 @@ DECLARE_PER_CPU(struct ia64_cpu, cpu_devices);
 
 DECLARE_PER_CPU(int, cpu_state);
 
-#ifdef CONFIG_HOTPLUG_CPU
-extern int arch_register_cpu(int num);
-extern void arch_unregister_cpu(int);
-#endif
-
 #endif /* _ASM_IA64_CPU_H_ */
diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c
index 94a848b06f15a9..741863a187a661 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -59,7 +59,7 @@ void __ref arch_unregister_cpu(int num)
 }
 EXPORT_SYMBOL(arch_unregister_cpu);
 #else
-static int __init arch_register_cpu(int num)
+int __init arch_register_cpu(int num)
 {
 	return register_cpu(&sysfs_cpus[num].cpu, num);
 }
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index 3a233ebff7129c..25050d953eee02 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -28,8 +28,6 @@ struct x86_cpu {
 };
 
 #ifdef CONFIG_HOTPLUG_CPU
-extern int arch_register_cpu(int num);
-extern void arch_unregister_cpu(int);
 extern void soft_restart_cpu(void);
 #endif
 
diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c
index ca004e2e44699e..0bab0313003362 100644
--- a/arch/x86/kernel/topology.c
+++ b/arch/x86/kernel/topology.c
@@ -54,7 +54,7 @@ void arch_unregister_cpu(int num)
 EXPORT_SYMBOL(arch_unregister_cpu);
 #else /* CONFIG_HOTPLUG_CPU */
 
-static int __init arch_register_cpu(int num)
+int __init arch_register_cpu(int num)
 {
 	return register_cpu(&per_cpu(cpu_devices, num).cpu, num);
 }
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index c711db8a9c3328..0f5218e361df5c 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -12,6 +12,7 @@
 #define pr_fmt(fmt) "ACPI: " fmt
 
 #include <linux/acpi.h>
+#include <linux/cpu.h>
 #include <linux/device.h>
 #include <linux/dmi.h>
 #include <linux/kernel.h>
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 94181fe9780a5e..3f34ebb275253e 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -465,9 +465,4 @@ extern int acpi_processor_ffh_lpi_probe(unsigned int cpu);
 extern int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi);
 #endif
 
-#ifdef CONFIG_ACPI_HOTPLUG_CPU
-extern int arch_register_cpu(int cpu);
-extern void arch_unregister_cpu(int cpu);
-#endif
-
 #endif
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 0abd60a7987b68..eb768a866fe31e 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -80,6 +80,8 @@ extern __printf(4, 5)
 struct device *cpu_device_create(struct device *parent, void *drvdata,
 				 const struct attribute_group **groups,
 				 const char *fmt, ...);
+extern int arch_register_cpu(int cpu);
+extern void arch_unregister_cpu(int cpu);
 #ifdef CONFIG_HOTPLUG_CPU
 extern void unregister_cpu(struct cpu *cpu);
 extern ssize_t arch_cpu_probe(const char *, size_t);