On 9/14/23 02:38, James Morse wrote:
Add arch_unregister_cpu() to allow the ACPI machinery to call
unregister_cpu(). This is enough for arm64, riscv and loongarch, but
needs to be overridden by x86 and ia64 who need to do more work.
CC: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
Signed-off-by: James Morse <james.morse@xxxxxxx>
---
Changes since v1:
* Added CONFIG_HOTPLUG_CPU ifdeffery around unregister_cpu
---
arch/ia64/include/asm/cpu.h | 4 ----
arch/loongarch/include/asm/cpu.h | 6 ------
arch/x86/include/asm/cpu.h | 1 -
drivers/base/cpu.c | 9 ++++++++-
4 files changed, 8 insertions(+), 12 deletions(-)
I agree with Jonathan this patch needs to come early. Maybe move this
before the following one:
[RFC PATCH v2 19/35] ACPI: Move acpi_bus_trim_one() before acpi_scan_hot_remove()
diff --git a/arch/ia64/include/asm/cpu.h b/arch/ia64/include/asm/cpu.h
index a3e690e685e5..642d71675ddb 100644
--- a/arch/ia64/include/asm/cpu.h
+++ b/arch/ia64/include/asm/cpu.h
@@ -15,8 +15,4 @@ DECLARE_PER_CPU(struct ia64_cpu, cpu_devices);
DECLARE_PER_CPU(int, cpu_state);
-#ifdef CONFIG_HOTPLUG_CPU
-extern void arch_unregister_cpu(int);
-#endif
-
#endif /* _ASM_IA64_CPU_H_ */
diff --git a/arch/loongarch/include/asm/cpu.h b/arch/loongarch/include/asm/cpu.h
index b8568e637420..48b9f7168bcc 100644
--- a/arch/loongarch/include/asm/cpu.h
+++ b/arch/loongarch/include/asm/cpu.h
@@ -128,10 +128,4 @@ enum cpu_type_enum {
#define LOONGARCH_CPU_HYPERVISOR BIT_ULL(CPU_FEATURE_HYPERVISOR)
#define LOONGARCH_CPU_PTW BIT_ULL(CPU_FEATURE_PTW)
-#if !defined(__ASSEMBLY__)
-#ifdef CONFIG_HOTPLUG_CPU
-void arch_unregister_cpu(int cpu);
-#endif
-#endif /* ! __ASSEMBLY__ */
-
#endif /* _ASM_CPU_H */
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index f349c94510e8..91867a6a9f8e 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -24,7 +24,6 @@ static inline void prefill_possible_map(void) {}
#endif /* CONFIG_SMP */
#ifdef CONFIG_HOTPLUG_CPU
-extern void arch_unregister_cpu(int);
extern void soft_restart_cpu(void);
#endif
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 677f963e02ce..c709747c4a18 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -531,7 +531,14 @@ int __weak arch_register_cpu(int cpu)
{
return register_cpu(&per_cpu(cpu_devices, cpu), cpu);
}
-#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+void __weak arch_unregister_cpu(int num)
+{
+ unregister_cpu(&per_cpu(cpu_devices, num));
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+#endif /* CONFIG_GENERIC_CPU_DEVICES */
It seems conflicting with its declaration in include/linux/cpu.h. Besides,
the function is still needed by drivers/acpi/acpi_processor.c::acpi_processor_make_not_present()
even both CONFIG_HOTPLUG_CPU and CONFIG_GENERIC_CPU_DEVICES are disabled?
static void __init cpu_dev_register_generic(void)
{
Thanks,
Gavin
