x86/cpuid: Move the hotplug callbacks to online

No point to have this file around before the cpu is online and no point to
have it around until the cpu is dead. Get rid of the explicit state.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Siewior <bigeasy@linutronix.de>

arch/x86/kernel/cpuid.c

@@ -45,6 +45,7 @@
 #include <asm/msr.h>
 
 static struct class *cpuid_class;
+static enum cpuhp_state cpuhp_cpuid_state;
 
 struct cpuid_regs {
 	u32 eax, ebx, ecx, edx;
@@ -152,11 +153,12 @@ static int __init cpuid_init(void)
 	}
 	cpuid_class->devnode = cpuid_devnode;
 
-	err = cpuhp_setup_state(CPUHP_X86_CPUID_PREPARE, "x86/cpuid:prepare",
+	err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/cpuid:online",
 				cpuid_device_create, cpuid_device_destroy);
-	if (err)
+	if (err < 0)
 		goto out_class;
 
+	cpuhp_cpuid_state = err;
 	return 0;
 
 out_class:
@@ -165,15 +167,14 @@ out_chrdev:
 	__unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");
 	return err;
 }
+module_init(cpuid_init);
 
 static void __exit cpuid_exit(void)
 {
-	cpuhp_remove_state(CPUHP_X86_CPUID_PREPARE);
+	cpuhp_remove_state(cpuhp_cpuid_state);
 	class_destroy(cpuid_class);
 	__unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");
 }
-
-module_init(cpuid_init);
 module_exit(cpuid_exit);
 
 MODULE_AUTHOR("H. Peter Anvin <hpa@zytor.com>");

include/linux/cpuhotplug.h

@@ -59,7 +59,6 @@ enum cpuhp_state {
 	CPUHP_BLK_MQ_PREPARE,
 	CPUHP_NET_FLOW_PREPARE,
 	CPUHP_TOPOLOGY_PREPARE,
-	CPUHP_X86_CPUID_PREPARE,
 	CPUHP_TIMERS_DEAD,
 	CPUHP_NOTF_ERR_INJ_PREPARE,
 	CPUHP_MIPS_SOC_PREPARE,