Commit 5490e769 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Peter Zijlstra
Browse files

ARM: 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 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/20230512205256.635326070@linutronix.de
parent 5356297d

arch/arm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -124,6 +124,7 @@ config ARM 
	select HAVE_SYSCALL_TRACEPOINTS

	select HAVE_UID16

	select HAVE_VIRT_CPU_ACCOUNTING_GEN

	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU

	select IRQ_FORCED_THREADING

	select MODULES_USE_ELF_REL

	select NEED_DMA_MAP_STATE

arch/arm/include/asm/smp.h

+1 −1
Original line number Diff line number Diff line
@@ -64,7 +64,7 @@ extern void secondary_startup_arm(void); 


extern int __cpu_disable(void);



extern void __cpu_die(unsigned int cpu);

static inline void __cpu_die(unsigned int cpu) { }



extern void arch_send_call_function_single_ipi(int cpu);

extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);

arch/arm/kernel/smp.c

+7 −11
Original line number Diff line number Diff line
@@ -288,15 +288,11 @@ int __cpu_disable(void) 
}



/*

 * 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)

{

	if (!cpu_wait_death(cpu, 5)) {

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

		return;

	}

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



	clear_tasks_mm_cpumask(cpu);
@@ -336,11 +332,11 @@ void __noreturn arch_cpu_idle_dead(void) 
	flush_cache_louis();



	/*

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

	 * this returns, power and/or clocks can be removed at any point

	 * from this CPU and its cache by platform_cpu_kill().

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

	 * of. Once this returns, power and/or clocks can be removed at

	 * any point from this CPU and its cache by platform_cpu_kill().

	 */

	(void)cpu_report_death();

	cpuhp_ap_report_dead();



	/*

	 * Ensure that the cache lines associated with that completion are