viocons.c

		tty_insert_flip_char(tty, cevent->data[index], TTY_NORMAL);
	}

	/* if cevent->len == 0 then no data was added to the buffer and flip.count == 0 */
	if (tty->flip.count)
		/* The next call resets flip.count when the data is flushed. */
		tty_flip_buffer_push(tty);
}

/*
 * Handle an ack charLpEvent. 
 */
static void vioHandleAck(struct HvLpEvent *event)
{
	struct viocharlpevent *cevent = (struct viocharlpevent *)event;
	unsigned long flags;
	u8 port = cevent->virtual_device;

	if (port >= VTTY_PORTS) {
		printk(VIOCONS_KERN_WARN "data on invalid virtual device\n");
		return;
	}

	spin_lock_irqsave(&consolelock, flags);
	port_info[port].ack = event->xCorrelationToken;
	spin_unlock_irqrestore(&consolelock, flags);

	if (port_info[port].used)
		send_buffers(&port_info[port]);
}

/*
 * Handle charLpEvents and route to the appropriate routine
 */
static void vioHandleCharEvent(struct HvLpEvent *event)
{
	int charminor;

	if (event == NULL)
		return;

	charminor = event->xSubtype & VIOMINOR_SUBTYPE_MASK;
	switch (charminor) {
	case viocharopen:
		vioHandleOpenEvent(event);
		break;
	case viocharclose:
		vioHandleCloseEvent(event);
		break;
	case viochardata:
		vioHandleData(event);
		break;
	case viocharack:
		vioHandleAck(event);
		break;
	case viocharconfig:
		vioHandleConfig(event);
		break;
	default:
		if ((event->xFlags.xFunction == HvLpEvent_Function_Int) &&
		    (event->xFlags.xAckInd == HvLpEvent_AckInd_DoAck)) {
			event->xRc = HvLpEvent_Rc_InvalidSubtype;
			HvCallEvent_ackLpEvent(event);
		}
	}
}

/*
 * Send an open event
 */
static int send_open(HvLpIndex remoteLp, void *sem)
{
	return HvCallEvent_signalLpEventFast(remoteLp,
			HvLpEvent_Type_VirtualIo,
			viomajorsubtype_chario | viocharopen,
			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
			viopath_sourceinst(remoteLp),
			viopath_targetinst(remoteLp),
			(u64)(unsigned long)sem, VIOVERSION << 16,
			0, 0, 0, 0);
}

static struct tty_operations serial_ops = {
	.open = viotty_open,
	.close = viotty_close,
	.write = viotty_write,
	.put_char = viotty_put_char,
	.write_room = viotty_write_room,
	.chars_in_buffer = viotty_chars_in_buffer,
	.ioctl = viotty_ioctl,
};

static int __init viocons_init2(void)
{
	atomic_t wait_flag;
	int rc;

	/* +2 for fudge */
	rc = viopath_open(HvLpConfig_getPrimaryLpIndex(),
			viomajorsubtype_chario, VIOCHAR_WINDOW + 2);
	if (rc)
		printk(VIOCONS_KERN_WARN "error opening to primary %d\n", rc);

	if (viopath_hostLp == HvLpIndexInvalid)
		vio_set_hostlp();

	/*
	 * And if the primary is not the same as the hosting LP, open to the 
	 * hosting lp
	 */
	if ((viopath_hostLp != HvLpIndexInvalid) &&
	    (viopath_hostLp != HvLpConfig_getPrimaryLpIndex())) {
		printk(VIOCONS_KERN_INFO "open path to hosting (%d)\n",
				viopath_hostLp);
		rc = viopath_open(viopath_hostLp, viomajorsubtype_chario,
				VIOCHAR_WINDOW + 2);	/* +2 for fudge */
		if (rc)
			printk(VIOCONS_KERN_WARN
				"error opening to partition %d: %d\n",
				viopath_hostLp, rc);
	}

	if (vio_setHandler(viomajorsubtype_chario, vioHandleCharEvent) < 0)
		printk(VIOCONS_KERN_WARN
				"error seting handler for console events!\n");

	/*
	 * First, try to open the console to the hosting lp.
	 * Wait on a semaphore for the response.
	 */
	atomic_set(&wait_flag, 0);
	if ((viopath_isactive(viopath_hostLp)) &&
	    (send_open(viopath_hostLp, (void *)&wait_flag) == 0)) {
		printk(VIOCONS_KERN_INFO "hosting partition %d\n",
			viopath_hostLp);
		while (atomic_read(&wait_flag) == 0)
			mb();
		atomic_set(&wait_flag, 0);
	}

	/*
	 * If we don't have an active console, try the primary
	 */
	if ((!viopath_isactive(port_info[0].lp)) &&
	    (viopath_isactive(HvLpConfig_getPrimaryLpIndex())) &&
	    (send_open(HvLpConfig_getPrimaryLpIndex(), (void *)&wait_flag)
	     == 0)) {
		printk(VIOCONS_KERN_INFO "opening console to primary partition\n");
		while (atomic_read(&wait_flag) == 0)
			mb();
	}

	/* Initialize the tty_driver structure */
	viotty_driver = alloc_tty_driver(VTTY_PORTS);
	viotty_driver->owner = THIS_MODULE;
	viotty_driver->driver_name = "vioconsole";
	viotty_driver->devfs_name = "vcs/";
	viotty_driver->name = "tty";
	viotty_driver->name_base = 1;
	viotty_driver->major = TTY_MAJOR;
	viotty_driver->minor_start = 1;
	viotty_driver->type = TTY_DRIVER_TYPE_CONSOLE;
	viotty_driver->subtype = 1;
	viotty_driver->init_termios = tty_std_termios;
	viotty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
	tty_set_operations(viotty_driver, &serial_ops);

	if (tty_register_driver(viotty_driver)) {
		printk(VIOCONS_KERN_WARN "couldn't register console driver\n");
		put_tty_driver(viotty_driver);
		viotty_driver = NULL;
	}

	unregister_console(&viocons_early);
	register_console(&viocons);

	return 0;
}

static int __init viocons_init(void)
{
	int i;

	printk(VIOCONS_KERN_INFO "registering console\n");
	for (i = 0; i < VTTY_PORTS; i++) {
		port_info[i].lp = HvLpIndexInvalid;
		port_info[i].magic = VIOTTY_MAGIC;
	}
	HvCall_setLogBufferFormatAndCodepage(HvCall_LogBuffer_ASCII, 437);
	register_console(&viocons_early);
	return 0;
}

console_initcall(viocons_init);
module_init(viocons_init2);