Commit b3091f17 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Peter Zijlstra
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arm64: 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: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: default avatarMark Rutland <mark.rutland@arm.com>
Tested-by: default avatarMichael Kelley <mikelley@microsoft.com>
Tested-by: default avatarOleksandr 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/20230512205256.690926018@linutronix.de
parent 5490e769

arch/arm64/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -222,6 +222,7 @@ config ARM64 
	select HAVE_KPROBES

	select HAVE_KRETPROBES

	select HAVE_GENERIC_VDSO

	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU

	select IRQ_DOMAIN

	select IRQ_FORCED_THREADING

	select KASAN_VMALLOC if KASAN

arch/arm64/include/asm/smp.h

+1 −1
Original line number Diff line number Diff line
@@ -99,7 +99,7 @@ static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask) 


extern int __cpu_disable(void);



extern void __cpu_die(unsigned int cpu);

static inline void __cpu_die(unsigned int cpu) { }

extern void __noreturn cpu_die(void);

extern void __noreturn cpu_die_early(void);

arch/arm64/kernel/smp.c

+5 −9
Original line number Diff line number Diff line
@@ -332,17 +332,13 @@ static int op_cpu_kill(unsigned int cpu) 
}



/*

 * called on the thread which is asking for a CPU to be shutdown -

 * waits until shutdown has completed, or it is timed out.

 * Called on the thread which is asking for a CPU to be shutdown after the

 * shutdown completed.

 */

void __cpu_die(unsigned int cpu)

void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu)

{

	int err;



	if (!cpu_wait_death(cpu, 5)) {

		pr_crit("CPU%u: cpu didn't die\n", cpu);

		return;

	}

	pr_debug("CPU%u: shutdown\n", cpu);



	/*
@@ -369,8 +365,8 @@ void __noreturn cpu_die(void) 


	local_daif_mask();



	/* Tell __cpu_die() that this CPU is now safe to dispose of */

	(void)cpu_report_death();

	/* Tell cpuhp_bp_sync_dead() that this CPU is now safe to dispose of */

	cpuhp_ap_report_dead();



	/*

	 * Actually shutdown the CPU. This must never fail. The specific hotplug