smp: Mark smp_prepare_boot_cpu() __init

smp_prepare_boot_cpu() is only called during boot, hence mark it as
__init.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://lore.kernel.org/all/20240907082720.452148-1-maobibo@loongson.cn

arch/loongarch/kernel/smp.c

@@ -476,7 +476,7 @@ core_initcall(ipi_pm_init);
 #endif
 
 /* Preload SMP state for boot cpu */
-void smp_prepare_boot_cpu(void)
+void __init smp_prepare_boot_cpu(void)
 {
 	unsigned int cpu, node, rr_node;
 

arch/mips/kernel/smp.c

@@ -439,7 +439,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 }
 
 /* preload SMP state for boot cpu */
-void smp_prepare_boot_cpu(void)
+void __init smp_prepare_boot_cpu(void)
 {
 	if (mp_ops->prepare_boot_cpu)
 		mp_ops->prepare_boot_cpu();

arch/powerpc/kernel/smp.c

@@ -1166,7 +1166,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 	cpu_smt_set_num_threads(num_threads, threads_per_core);
 }
 
-void smp_prepare_boot_cpu(void)
+void __init smp_prepare_boot_cpu(void)
 {
 	BUG_ON(smp_processor_id() != boot_cpuid);
 #ifdef CONFIG_PPC64

include/linux/smp.h

@@ -109,7 +109,7 @@ static inline void on_each_cpu_cond(smp_cond_func_t cond_func,
  * Architecture specific boot CPU setup.  Defined as empty weak function in
  * init/main.c. Architectures can override it.
  */
-void smp_prepare_boot_cpu(void);
+void __init smp_prepare_boot_cpu(void);
 
 #ifdef CONFIG_SMP