void vfio_pci_core_disable()

in pci/vfio_pci_core.c [315:410]

• 58 lines of code
• 11 McCabe index (conditional complexity)

void vfio_pci_core_disable(struct vfio_pci_core_device *vdev)
{
	struct pci_dev *pdev = vdev->pdev;
	struct vfio_pci_dummy_resource *dummy_res, *tmp;
	struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp;
	int i, bar;

	/* For needs_reset */
	lockdep_assert_held(&vdev->vdev.dev_set->lock);

	/* Stop the device from further DMA */
	pci_clear_master(pdev);

	vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
				VFIO_IRQ_SET_ACTION_TRIGGER,
				vdev->irq_type, 0, 0, NULL);

	/* Device closed, don't need mutex here */
	list_for_each_entry_safe(ioeventfd, ioeventfd_tmp,
				 &vdev->ioeventfds_list, next) {
		vfio_virqfd_disable(&ioeventfd->virqfd);
		list_del(&ioeventfd->next);
		kfree(ioeventfd);
	}
	vdev->ioeventfds_nr = 0;

	vdev->virq_disabled = false;

	for (i = 0; i < vdev->num_regions; i++)
		vdev->region[i].ops->release(vdev, &vdev->region[i]);

	vdev->num_regions = 0;
	kfree(vdev->region);
	vdev->region = NULL; /* don't krealloc a freed pointer */

	vfio_config_free(vdev);

	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
		bar = i + PCI_STD_RESOURCES;
		if (!vdev->barmap[bar])
			continue;
		pci_iounmap(pdev, vdev->barmap[bar]);
		pci_release_selected_regions(pdev, 1 << bar);
		vdev->barmap[bar] = NULL;
	}

	list_for_each_entry_safe(dummy_res, tmp,
				 &vdev->dummy_resources_list, res_next) {
		list_del(&dummy_res->res_next);
		release_resource(&dummy_res->resource);
		kfree(dummy_res);
	}

	vdev->needs_reset = true;

	/*
	 * If we have saved state, restore it.  If we can reset the device,
	 * even better.  Resetting with current state seems better than
	 * nothing, but saving and restoring current state without reset
	 * is just busy work.
	 */
	if (pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state)) {
		pci_info(pdev, "%s: Couldn't reload saved state\n", __func__);

		if (!vdev->reset_works)
			goto out;

		pci_save_state(pdev);
	}

	/*
	 * Disable INTx and MSI, presumably to avoid spurious interrupts
	 * during reset.  Stolen from pci_reset_function()
	 */
	pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);

	/*
	 * Try to get the locks ourselves to prevent a deadlock. The
	 * success of this is dependent on being able to lock the device,
	 * which is not always possible.
	 * We can not use the "try" reset interface here, which will
	 * overwrite the previously restored configuration information.
	 */
	if (vdev->reset_works && pci_dev_trylock(pdev)) {
		if (!__pci_reset_function_locked(pdev))
			vdev->needs_reset = false;
		pci_dev_unlock(pdev);
	}

	pci_restore_state(pdev);
out:
	pci_disable_device(pdev);

	if (!vfio_pci_dev_set_try_reset(vdev->vdev.dev_set) && !disable_idle_d3)
		vfio_pci_set_power_state(vdev, PCI_D3hot);
}