static int __init riscv_timer_init_dt()

in timer-riscv.c [102:169]

• 59 lines of code
• 10 McCabe index (conditional complexity)

static int __init riscv_timer_init_dt(struct device_node *n)
{
	int cpuid, hartid, error;
	struct device_node *child;
	struct irq_domain *domain;

	hartid = riscv_of_processor_hartid(n);
	if (hartid < 0) {
		pr_warn("Not valid hartid for node [%pOF] error = [%d]\n",
			n, hartid);
		return hartid;
	}

	cpuid = riscv_hartid_to_cpuid(hartid);
	if (cpuid < 0) {
		pr_warn("Invalid cpuid for hartid [%d]\n", hartid);
		return cpuid;
	}

	if (cpuid != smp_processor_id())
		return 0;

	domain = NULL;
	child = of_get_compatible_child(n, "riscv,cpu-intc");
	if (!child) {
		pr_err("Failed to find INTC node [%pOF]\n", n);
		return -ENODEV;
	}
	domain = irq_find_host(child);
	of_node_put(child);
	if (!domain) {
		pr_err("Failed to find IRQ domain for node [%pOF]\n", n);
		return -ENODEV;
	}

	riscv_clock_event_irq = irq_create_mapping(domain, RV_IRQ_TIMER);
	if (!riscv_clock_event_irq) {
		pr_err("Failed to map timer interrupt for node [%pOF]\n", n);
		return -ENODEV;
	}

	pr_info("%s: Registering clocksource cpuid [%d] hartid [%d]\n",
	       __func__, cpuid, hartid);
	error = clocksource_register_hz(&riscv_clocksource, riscv_timebase);
	if (error) {
		pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
		       error, cpuid);
		return error;
	}

	sched_clock_register(riscv_sched_clock, 64, riscv_timebase);

	error = request_percpu_irq(riscv_clock_event_irq,
				    riscv_timer_interrupt,
				    "riscv-timer", &riscv_clock_event);
	if (error) {
		pr_err("registering percpu irq failed [%d]\n", error);
		return error;
	}

	error = cpuhp_setup_state(CPUHP_AP_RISCV_TIMER_STARTING,
			 "clockevents/riscv/timer:starting",
			 riscv_timer_starting_cpu, riscv_timer_dying_cpu);
	if (error)
		pr_err("cpu hp setup state failed for RISCV timer [%d]\n",
		       error);
	return error;
}