x86, hotplug, suspend: Online CPU0 for suspend or hibernate (209efae1) · Commits · 戴 / test

arch/x86/power/cpu.c

+44 −0

Original line number	Diff line number	Diff line
		@@ -237,3 +237,47 @@ void restore_processor_state(void)
		#ifdef CONFIG_X86_32
		EXPORT_SYMBOL(restore_processor_state);
		#endif

		/*
		* When bsp_check() is called in hibernate and suspend, cpu hotplug
		* is disabled already. So it's unnessary to handle race condition between
		* cpumask query and cpu hotplug.
		*/
		static int bsp_check(void)
		{
		if (cpumask_first(cpu_online_mask) != 0) {
		pr_warn("CPU0 is offline.\n");
		return -ENODEV;
		}

		return 0;
		}

		static int bsp_pm_callback(struct notifier_block *nb, unsigned long action,
		void *ptr)
		{
		int ret = 0;

		switch (action) {
		case PM_SUSPEND_PREPARE:
		case PM_HIBERNATION_PREPARE:
		ret = bsp_check();
		break;
		default:
		break;
		}
		return notifier_from_errno(ret);
		}

		static int __init bsp_pm_check_init(void)
		{
		/*
		* Set this bsp_pm_callback as lower priority than
		* cpu_hotplug_pm_callback. So cpu_hotplug_pm_callback will be called
		* earlier to disable cpu hotplug before bsp online check.
		*/
		pm_notifier(bsp_pm_callback, -INT_MAX);
		return 0;
		}

		core_initcall(bsp_pm_check_init);