csky/smp: Switch to hotplug core state synchronization

Switch to the CPU hotplug core state tracking and synchronization
mechanim. No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Link: https://lore.kernel.org/r/20230512205256.747254502@linutronix.de

arch/csky/Kconfig

@@ -96,6 +96,7 @@ config CSKY
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_STACKPROTECTOR
 	select HAVE_SYSCALL_TRACEPOINTS
+	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
 	select MAY_HAVE_SPARSE_IRQ
 	select MODULES_USE_ELF_RELA if MODULES
 	select OF

arch/csky/include/asm/smp.h

@@ -23,7 +23,7 @@ void __init set_send_ipi(void (*func)(const struct cpumask *mask), int irq);
 
 int __cpu_disable(void);
 
-void __cpu_die(unsigned int cpu);
+static inline void __cpu_die(unsigned int cpu) { }
 
 #endif /* CONFIG_SMP */
 

arch/csky/kernel/smp.c

@@ -291,12 +291,8 @@ int __cpu_disable(void)
 	return 0;
 }
 
-void __cpu_die(unsigned int cpu)
+void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu)
 {
-	if (!cpu_wait_death(cpu, 5)) {
-		pr_crit("CPU%u: shutdown failed\n", cpu);
-		return;
-	}
 	pr_notice("CPU%u: shutdown\n", cpu);
 }
 
@@ -304,7 +300,7 @@ void __noreturn arch_cpu_idle_dead(void)
 {
 	idle_task_exit();
 
-	cpu_report_death();
+	cpuhp_ap_report_dead();
 
 	while (!secondary_stack)
 		arch_cpu_idle();