[RFC PATCH 08/32] x86/topology: Switch over to GENERIC_CPU_DEVICES

From: James Morse
Date: Fri Feb 03 2023 - 08:53:49 EST


Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be
overridden by the arch code, switch over to this to allow common code
to choose when the register_cpu() call is made.

x86's struct cpus come from struct x86_cpu, which has no other members
or users. Remove this and use the version defined by common code.

This is an intermediate step to the logic being moved to drivers/acpi,
where GENERIC_CPU_DEVICES will do the work when booting with acpi=off.

Signed-off-by: James Morse <james.morse@xxxxxxx>
---
arch/x86/Kconfig | 1 +
arch/x86/include/asm/cpu.h | 4 ----
arch/x86/kernel/topology.c | 19 +++----------------
3 files changed, 4 insertions(+), 20 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 6a520c22c3eb..e1aaee2f8412 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -144,6 +144,7 @@ config X86
select GENERIC_CLOCKEVENTS_MIN_ADJUST
select GENERIC_CMOS_UPDATE
select GENERIC_CPU_AUTOPROBE
+ select GENERIC_CPU_DEVICES
select GENERIC_CPU_VULNERABILITIES
select GENERIC_EARLY_IOREMAP
select GENERIC_ENTRY
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index a0a62ac00e88..2955541abebb 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -23,10 +23,6 @@ static inline void prefill_possible_map(void) {}

#endif /* CONFIG_SMP */

-struct x86_cpu {
- struct cpu cpu;
-};
-
#ifdef CONFIG_HOTPLUG_CPU
extern void arch_unregister_cpu(int);
extern void start_cpu0(void);
diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c
index 1b83377274b8..2275e22dfc8b 100644
--- a/arch/x86/kernel/topology.c
+++ b/arch/x86/kernel/topology.c
@@ -35,8 +35,6 @@
#include <asm/io_apic.h>
#include <asm/cpu.h>

-static DEFINE_PER_CPU(struct x86_cpu, cpu_devices);
-
#ifdef CONFIG_HOTPLUG_CPU

#ifdef CONFIG_BOOTPARAM_HOTPLUG_CPU0
@@ -131,15 +129,15 @@ int arch_register_cpu(int num)
}
}
if (num || cpu0_hotpluggable)
- per_cpu(cpu_devices, num).cpu.hotpluggable = 1;
+ per_cpu(cpu_devices, num).hotpluggable = 1;

- return register_cpu(&per_cpu(cpu_devices, num).cpu, num);
+ return register_cpu(&per_cpu(cpu_devices, num), num);
}
EXPORT_SYMBOL(arch_register_cpu);

void arch_unregister_cpu(int num)
{
- unregister_cpu(&per_cpu(cpu_devices, num).cpu);
+ unregister_cpu(&per_cpu(cpu_devices, num));
}
EXPORT_SYMBOL(arch_unregister_cpu);
#else /* CONFIG_HOTPLUG_CPU */
@@ -149,14 +147,3 @@ static int __init arch_register_cpu(int num)
return register_cpu(&per_cpu(cpu_devices, num).cpu, num);
}
#endif /* CONFIG_HOTPLUG_CPU */
-
-static int __init topology_init(void)
-{
- int i;
-
- for_each_present_cpu(i)
- arch_register_cpu(i);
-
- return 0;
-}
-subsys_initcall(topology_init);
--
2.30.2