void start_secondary()

in kernel/smp.c [127:169]

• 28 lines of code
• 2 McCabe index (conditional complexity)

void start_secondary(void)
{
	unsigned long thread_ptr;
	unsigned int cpu, irq;

	/*  Calculate thread_info pointer from stack pointer  */
	__asm__ __volatile__(
		"%0 = SP;\n"
		: "=r" (thread_ptr)
	);

	thread_ptr = thread_ptr & ~(THREAD_SIZE-1);

	__asm__ __volatile__(
		QUOTED_THREADINFO_REG " = %0;\n"
		:
		: "r" (thread_ptr)
	);

	/*  Set the memory struct  */
	mmgrab(&init_mm);
	current->active_mm = &init_mm;

	cpu = smp_processor_id();

	irq = BASE_IPI_IRQ + cpu;
	if (request_irq(irq, handle_ipi, IRQF_TRIGGER_RISING, "ipi_handler",
			NULL))
		pr_err("Failed to request irq %u (ipi_handler)\n", irq);

	/*  Register the clock_event dummy  */
	setup_percpu_clockdev();

	printk(KERN_INFO "%s cpu %d\n", __func__, current_thread_info()->cpu);

	notify_cpu_starting(cpu);

	set_cpu_online(cpu, true);

	local_irq_enable();

	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
}