static int omap_enter_idle_coupled()

in mach-omap2/cpuidle44xx.c [119:232]

• 63 lines of code
• 19 McCabe index (conditional complexity)

static int omap_enter_idle_coupled(struct cpuidle_device *dev,
			struct cpuidle_driver *drv,
			int index)
{
	struct idle_statedata *cx = state_ptr + index;
	u32 mpuss_can_lose_context = 0;
	int error;

	/*
	 * CPU0 has to wait and stay ON until CPU1 is OFF state.
	 * This is necessary to honour hardware recommondation
	 * of triggeing all the possible low power modes once CPU1 is
	 * out of coherency and in OFF mode.
	 */
	if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
		while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) {
			cpu_relax();

			/*
			 * CPU1 could have already entered & exited idle
			 * without hitting off because of a wakeup
			 * or a failed attempt to hit off mode.  Check for
			 * that here, otherwise we could spin forever
			 * waiting for CPU1 off.
			 */
			if (cpu_done[1])
			    goto fail;

		}
	}

	mpuss_can_lose_context = (cx->mpu_state == PWRDM_POWER_RET) &&
				 (cx->mpu_logic_state == PWRDM_POWER_OFF);

	/* Enter broadcast mode for periodic timers */
	RCU_NONIDLE(tick_broadcast_enable());

	/* Enter broadcast mode for one-shot timers */
	RCU_NONIDLE(tick_broadcast_enter());

	/*
	 * Call idle CPU PM enter notifier chain so that
	 * VFP and per CPU interrupt context is saved.
	 */
	error = cpu_pm_enter();
	if (error)
		goto cpu_pm_out;

	if (dev->cpu == 0) {
		pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
		RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state));

		/*
		 * Call idle CPU cluster PM enter notifier chain
		 * to save GIC and wakeupgen context.
		 */
		if (mpuss_can_lose_context) {
			error = cpu_cluster_pm_enter();
			if (error) {
				index = 0;
				cx = state_ptr + index;
				pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
				RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state));
				mpuss_can_lose_context = 0;
			}
		}
	}

	omap4_enter_lowpower(dev->cpu, cx->cpu_state);
	cpu_done[dev->cpu] = true;

	/* Wakeup CPU1 only if it is not offlined */
	if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {

		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) &&
		    mpuss_can_lose_context)
			gic_dist_disable();

		RCU_NONIDLE(clkdm_deny_idle(cpu_clkdm[1]));
		RCU_NONIDLE(omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON));
		RCU_NONIDLE(clkdm_allow_idle(cpu_clkdm[1]));

		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) &&
		    mpuss_can_lose_context) {
			while (gic_dist_disabled()) {
				udelay(1);
				cpu_relax();
			}
			gic_timer_retrigger();
		}
	}

	/*
	 * Call idle CPU cluster PM exit notifier chain
	 * to restore GIC and wakeupgen context.
	 */
	if (dev->cpu == 0 && mpuss_can_lose_context)
		cpu_cluster_pm_exit();

	/*
	 * Call idle CPU PM exit notifier chain to restore
	 * VFP and per CPU IRQ context.
	 */
	cpu_pm_exit();

cpu_pm_out:
	RCU_NONIDLE(tick_broadcast_exit());

fail:
	cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
	cpu_done[dev->cpu] = false;

	return index;
}