static int mhi_pm_mission_mode_transition()

in mhi/core/pm.c [374:448]

• 51 lines of code
• 9 McCabe index (conditional complexity)

static int mhi_pm_mission_mode_transition(struct mhi_controller *mhi_cntrl)
{
	struct mhi_event *mhi_event;
	struct device *dev = &mhi_cntrl->mhi_dev->dev;
	enum mhi_ee_type ee = MHI_EE_MAX, current_ee = mhi_cntrl->ee;
	int i, ret;

	dev_dbg(dev, "Processing Mission Mode transition\n");

	write_lock_irq(&mhi_cntrl->pm_lock);
	if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state))
		ee = mhi_get_exec_env(mhi_cntrl);

	if (!MHI_IN_MISSION_MODE(ee)) {
		mhi_cntrl->pm_state = MHI_PM_LD_ERR_FATAL_DETECT;
		write_unlock_irq(&mhi_cntrl->pm_lock);
		wake_up_all(&mhi_cntrl->state_event);
		return -EIO;
	}
	mhi_cntrl->ee = ee;
	write_unlock_irq(&mhi_cntrl->pm_lock);

	wake_up_all(&mhi_cntrl->state_event);

	device_for_each_child(&mhi_cntrl->mhi_dev->dev, &current_ee,
			      mhi_destroy_device);
	mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_MISSION_MODE);

	/* Force MHI to be in M0 state before continuing */
	ret = __mhi_device_get_sync(mhi_cntrl);
	if (ret)
		return ret;

	read_lock_bh(&mhi_cntrl->pm_lock);

	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
		ret = -EIO;
		goto error_mission_mode;
	}

	/* Add elements to all HW event rings */
	mhi_event = mhi_cntrl->mhi_event;
	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
		struct mhi_ring *ring = &mhi_event->ring;

		if (mhi_event->offload_ev || !mhi_event->hw_ring)
			continue;

		ring->wp = ring->base + ring->len - ring->el_size;
		*ring->ctxt_wp = ring->iommu_base + ring->len - ring->el_size;
		/* Update to all cores */
		smp_wmb();

		spin_lock_irq(&mhi_event->lock);
		if (MHI_DB_ACCESS_VALID(mhi_cntrl))
			mhi_ring_er_db(mhi_event);
		spin_unlock_irq(&mhi_event->lock);
	}

	read_unlock_bh(&mhi_cntrl->pm_lock);

	/*
	 * The MHI devices are only created when the client device switches its
	 * Execution Environment (EE) to either SBL or AMSS states
	 */
	mhi_create_devices(mhi_cntrl);

	read_lock_bh(&mhi_cntrl->pm_lock);

error_mission_mode:
	mhi_cntrl->wake_put(mhi_cntrl, false);
	read_unlock_bh(&mhi_cntrl->pm_lock);

	return ret;
}