ctcmain.c

linux-2.6.15.6

		ch = ch->next;
	}
#ifdef DEBUG
	ctc_pr_debug("ctc: %s(): ch=0x%pq (id=%s, type=%d\n",
		     __func__, ch, ch->id, ch->type);
#endif
	if (!ch) {
		ctc_pr_warn("ctc: %s(): channel with id %s "
			    "and type %d not found in channel list\n",
			    __func__, id, type);
	} else {
		if (ch->flags & CHANNEL_FLAGS_INUSE)
			ch = NULL;
		else {
			ch->flags |= CHANNEL_FLAGS_INUSE;
			ch->flags &= ~CHANNEL_FLAGS_RWMASK;
			ch->flags |= (direction == WRITE)
			    ? CHANNEL_FLAGS_WRITE : CHANNEL_FLAGS_READ;
			fsm_newstate(ch->fsm, CH_STATE_STOPPED);
		}
	}
	return ch;
}

/**
 * Return the channel type by name.
 *
 * @param name Name of network interface.
 *
 * @return Type class of channel to be used for that interface.
 */
static enum channel_types inline
extract_channel_media(char *name)
{
	enum channel_types ret = channel_type_unknown;

	if (name != NULL) {
		if (strncmp(name, "ctc", 3) == 0)
			ret = channel_type_parallel;
		if (strncmp(name, "escon", 5) == 0)
			ret = channel_type_escon;
	}
	return ret;
}

static long
__ctc_check_irb_error(struct ccw_device *cdev, struct irb *irb)
{
	if (!IS_ERR(irb))
		return 0;

	switch (PTR_ERR(irb)) {
	case -EIO:
		ctc_pr_warn("i/o-error on device %s\n", cdev->dev.bus_id);
//		CTC_DBF_TEXT(trace, 2, "ckirberr");
//		CTC_DBF_TEXT_(trace, 2, "  rc%d", -EIO);
		break;
	case -ETIMEDOUT:
		ctc_pr_warn("timeout on device %s\n", cdev->dev.bus_id);
//		CTC_DBF_TEXT(trace, 2, "ckirberr");
//		CTC_DBF_TEXT_(trace, 2, "  rc%d", -ETIMEDOUT);
		break;
	default:
		ctc_pr_warn("unknown error %ld on device %s\n", PTR_ERR(irb),
			   cdev->dev.bus_id);
//		CTC_DBF_TEXT(trace, 2, "ckirberr");
//		CTC_DBF_TEXT(trace, 2, "  rc???");
	}
	return PTR_ERR(irb);
}

/**
 * Main IRQ handler.
 *
 * @param cdev    The ccw_device the interrupt is for.
 * @param intparm interruption parameter.
 * @param irb     interruption response block.
 */
static void
ctc_irq_handler(struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
{
	struct channel *ch;
	struct net_device *dev;
	struct ctc_priv *priv;

	DBF_TEXT(trace, 5, __FUNCTION__);
	if (__ctc_check_irb_error(cdev, irb))
		return;

	/* Check for unsolicited interrupts. */
	if (!cdev->dev.driver_data) {
		ctc_pr_warn("ctc: Got unsolicited irq: %s c-%02x d-%02x\n",
			    cdev->dev.bus_id, irb->scsw.cstat,
			    irb->scsw.dstat);
		return;
	}
	
	priv = ((struct ccwgroup_device *)cdev->dev.driver_data)
		->dev.driver_data;

	/* Try to extract channel from driver data. */
	if (priv->channel[READ]->cdev == cdev)
		ch = priv->channel[READ];
	else if (priv->channel[WRITE]->cdev == cdev)
		ch = priv->channel[WRITE];
	else {
		ctc_pr_err("ctc: Can't determine channel for interrupt, "
			   "device %s\n", cdev->dev.bus_id);
		return;
	}
	
	dev = (struct net_device *) (ch->netdev);
	if (dev == NULL) {
		ctc_pr_crit("ctc: ctc_irq_handler dev=NULL bus_id=%s, ch=0x%p\n",
			    cdev->dev.bus_id, ch);
		return;
	}

#ifdef DEBUG
	ctc_pr_debug("%s: interrupt for device: %s received c-%02x d-%02x\n",
		     dev->name, ch->id, irb->scsw.cstat, irb->scsw.dstat);
#endif

	/* Copy interruption response block. */
	memcpy(ch->irb, irb, sizeof(struct irb));

	/* Check for good subchannel return code, otherwise error message */
	if (ch->irb->scsw.cstat) {
		fsm_event(ch->fsm, CH_EVENT_SC_UNKNOWN, ch);
		ctc_pr_warn("%s: subchannel check for device: %s - %02x %02x\n",
			    dev->name, ch->id, ch->irb->scsw.cstat,
			    ch->irb->scsw.dstat);
		return;
	}

	/* Check the reason-code of a unit check */
	if (ch->irb->scsw.dstat & DEV_STAT_UNIT_CHECK) {
		ccw_unit_check(ch, ch->irb->ecw[0]);
		return;
	}
	if (ch->irb->scsw.dstat & DEV_STAT_BUSY) {
		if (ch->irb->scsw.dstat & DEV_STAT_ATTENTION)
			fsm_event(ch->fsm, CH_EVENT_ATTNBUSY, ch);
		else
			fsm_event(ch->fsm, CH_EVENT_BUSY, ch);
		return;
	}
	if (ch->irb->scsw.dstat & DEV_STAT_ATTENTION) {
		fsm_event(ch->fsm, CH_EVENT_ATTN, ch);
		return;
	}
	if ((ch->irb->scsw.stctl & SCSW_STCTL_SEC_STATUS) ||
	    (ch->irb->scsw.stctl == SCSW_STCTL_STATUS_PEND) ||
	    (ch->irb->scsw.stctl ==
	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)))
		fsm_event(ch->fsm, CH_EVENT_FINSTAT, ch);
	else
		fsm_event(ch->fsm, CH_EVENT_IRQ, ch);

}

/**
 * Actions for interface - statemachine.
 *****************************************************************************/

/**
 * Startup channels by sending CH_EVENT_START to each channel.
 *
 * @param fi    An instance of an interface statemachine.
 * @param event The event, just happened.
 * @param arg   Generic pointer, casted from struct net_device * upon call.
 */
static void
dev_action_start(fsm_instance * fi, int event, void *arg)
{
	struct net_device *dev = (struct net_device *) arg;
	struct ctc_priv *privptr = dev->priv;
	int direction;

	DBF_TEXT(setup, 3, __FUNCTION__);
	fsm_deltimer(&privptr->restart_timer);
	fsm_newstate(fi, DEV_STATE_STARTWAIT_RXTX);
	for (direction = READ; direction <= WRITE; direction++) {
		struct channel *ch = privptr->channel[direction];
		fsm_event(ch->fsm, CH_EVENT_START, ch);
	}
}

/**
 * Shutdown channels by sending CH_EVENT_STOP to each channel.
 *
 * @param fi    An instance of an interface statemachine.
 * @param event The event, just happened.
 * @param arg   Generic pointer, casted from struct net_device * upon call.
 */
static void
dev_action_stop(fsm_instance * fi, int event, void *arg)
{
	struct net_device *dev = (struct net_device *) arg;
	struct ctc_priv *privptr = dev->priv;
	int direction;

	DBF_TEXT(trace, 3, __FUNCTION__);
	fsm_newstate(fi, DEV_STATE_STOPWAIT_RXTX);
	for (direction = READ; direction <= WRITE; direction++) {
		struct channel *ch = privptr->channel[direction];
		fsm_event(ch->fsm, CH_EVENT_STOP, ch);
	}
}
static void 
dev_action_restart(fsm_instance *fi, int event, void *arg)
{
	struct net_device *dev = (struct net_device *)arg;
	struct ctc_priv *privptr = dev->priv;
	
	DBF_TEXT(trace, 3, __FUNCTION__);
	ctc_pr_debug("%s: Restarting\n", dev->name);
	dev_action_stop(fi, event, arg);
	fsm_event(privptr->fsm, DEV_EVENT_STOP, dev);
	fsm_addtimer(&privptr->restart_timer, CTC_TIMEOUT_5SEC,
		     DEV_EVENT_START, dev);
}

/**
 * Called from channel statemachine
 * when a channel is up and running.
 *
 * @param fi    An instance of an interface statemachine.
 * @param event The event, just happened.
 * @param arg   Generic pointer, casted from struct net_device * upon call.
 */
static void
dev_action_chup(fsm_instance * fi, int event, void *arg)
{
	struct net_device *dev = (struct net_device *) arg;
	struct ctc_priv *privptr = dev->priv;

	DBF_TEXT(trace, 3, __FUNCTION__);
	switch (fsm_getstate(fi)) {
		case DEV_STATE_STARTWAIT_RXTX:
			if (event == DEV_EVENT_RXUP)
				fsm_newstate(fi, DEV_STATE_STARTWAIT_TX);
			else
				fsm_newstate(fi, DEV_STATE_STARTWAIT_RX);
			break;
		case DEV_STATE_STARTWAIT_RX:
			if (event == DEV_EVENT_RXUP) {
				fsm_newstate(fi, DEV_STATE_RUNNING);
				ctc_pr_info("%s: connected with remote side\n",
					    dev->name);
				if (privptr->protocol == CTC_PROTO_LINUX_TTY)
					ctc_tty_setcarrier(dev, 1);
				ctc_clear_busy(dev);
			}
			break;
		case DEV_STATE_STARTWAIT_TX:
			if (event == DEV_EVENT_TXUP) {
				fsm_newstate(fi, DEV_STATE_RUNNING);
				ctc_pr_info("%s: connected with remote side\n",
					    dev->name);
				if (privptr->protocol == CTC_PROTO_LINUX_TTY)
					ctc_tty_setcarrier(dev, 1);
				ctc_clear_busy(dev);
			}
			break;
		case DEV_STATE_STOPWAIT_TX:
			if (event == DEV_EVENT_RXUP)
				fsm_newstate(fi, DEV_STATE_STOPWAIT_RXTX);
			break;
		case DEV_STATE_STOPWAIT_RX:
			if (event == DEV_EVENT_TXUP)
				fsm_newstate(fi, DEV_STATE_STOPWAIT_RXTX);
			break;
	}
}

/**
 * Called from channel statemachine
 * when a channel has been shutdown.
 *
 * @param fi    An instance of an interface statemachine.
 * @param event The event, just happened.
 * @param arg   Generic pointer, casted from struct net_device * upon call.
 */
static void
dev_action_chdown(fsm_instance * fi, int event, void *arg)
{
	struct net_device *dev = (struct net_device *) arg;
	struct ctc_priv *privptr = dev->priv;

	DBF_TEXT(trace, 3, __FUNCTION__);
	switch (fsm_getstate(fi)) {
		case DEV_STATE_RUNNING:
			if (privptr->protocol == CTC_PROTO_LINUX_TTY)
				ctc_tty_setcarrier(dev, 0);
			if (event == DEV_EVENT_TXDOWN)
				fsm_newstate(fi, DEV_STATE_STARTWAIT_TX);
			else
				fsm_newstate(fi, DEV_STATE_STARTWAIT_RX);
			break;
		case DEV_STATE_STARTWAIT_RX:
			if (event == DEV_EVENT_TXDOWN)
				fsm_newstate(fi, DEV_STATE_STARTWAIT_RXTX);
			break;
		case DEV_STATE_STARTWAIT_TX:
			if (event == DEV_EVENT_RXDOWN)
				fsm_newstate(fi, DEV_STATE_STARTWAIT_RXTX);
			break;
		case DEV_STATE_STOPWAIT_RXTX:
			if (event == DEV_EVENT_TXDOWN)
				fsm_newstate(fi, DEV_STATE_STOPWAIT_RX);
			else
				fsm_newstate(fi, DEV_STATE_STOPWAIT_TX);
			break;
		case DEV_STATE_STOPWAIT_RX:
			if (event == DEV_EVENT_RXDOWN)
				fsm_newstate(fi, DEV_STATE_STOPPED);
			break;
		case DEV_STATE_STOPWAIT_TX:
			if (event == DEV_EVENT_TXDOWN)
				fsm_newstate(fi, DEV_STATE_STOPPED);
			break;
	}
}

static const fsm_node dev_fsm[] = {
	{DEV_STATE_STOPPED, DEV_EVENT_START, dev_action_start},

	{DEV_STATE_STOPWAIT_RXTX,  DEV_EVENT_START,   dev_action_start   },
	{DEV_STATE_STOPWAIT_RXTX,  DEV_EVENT_RXDOWN,  dev_action_chdown  },
	{DEV_STATE_STOPWAIT_RXTX,  DEV_EVENT_TXDOWN,  dev_action_chdown  },
 	{DEV_STATE_STOPWAIT_RXTX,  DEV_EVENT_RESTART, dev_action_restart },

	{DEV_STATE_STOPWAIT_RX,    DEV_EVENT_START,   dev_action_start   },
	{DEV_STATE_STOPWAIT_RX,    DEV_EVENT_RXUP,    dev_action_chup    },
	{DEV_STATE_STOPWAIT_RX,    DEV_EVENT_TXUP,    dev_action_chup    },
	{DEV_STATE_STOPWAIT_RX,    DEV_EVENT_RXDOWN,  dev_action_chdown  },
 	{DEV_STATE_STOPWAIT_RX,    DEV_EVENT_RESTART, dev_action_restart },

	{DEV_STATE_STOPWAIT_TX,    DEV_EVENT_START,   dev_action_start   },
	{DEV_STATE_STOPWAIT_TX,    DEV_EVENT_RXUP,    dev_action_chup    },
	{DEV_STATE_STOPWAIT_TX,    DEV_EVENT_TXUP,    dev_action_chup    },
	{DEV_STATE_STOPWAIT_TX,    DEV_EVENT_TXDOWN,  dev_action_chdown  },
 	{DEV_STATE_STOPWAIT_TX,    DEV_EVENT_RESTART, dev_action_restart },

	{DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_STOP,    dev_action_stop    },
	{DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_RXUP,    dev_action_chup    },
	{DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_TXUP,    dev_action_chup    },
	{DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_RXDOWN,  dev_action_chdown  },
	{DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_TXDOWN,  dev_action_chdown  },
 	{DEV_STATE_STARTWAIT_RXTX, DEV_EVENT_RESTART, dev_action_restart },

	{DEV_STATE_STARTWAIT_TX,   DEV_EVENT_STOP,    dev_action_stop    },
	{DEV_STATE_STARTWAIT_TX,   DEV_EVENT_RXUP,    dev_action_chup    },
	{DEV_STATE_STARTWAIT_TX,   DEV_EVENT_TXUP,    dev_action_chup    },
	{DEV_STATE_STARTWAIT_TX,   DEV_EVENT_RXDOWN,  dev_action_chdown  },
 	{DEV_STATE_STARTWAIT_TX,   DEV_EVENT_RESTART, dev_action_restart },

	{DEV_STATE_STARTWAIT_RX,   DEV_EVENT_STOP,    dev_action_stop    },
	{DEV_STATE_STARTWAIT_RX,   DEV_EVENT_RXUP,    dev_action_chup    },
	{DEV_STATE_STARTWAIT_RX,   DEV_EVENT_TXUP,    dev_action_chup    },
	{DEV_STATE_STARTWAIT_RX,   DEV_EVENT_TXDOWN,  dev_action_chdown  },
 	{DEV_STATE_STARTWAIT_RX,   DEV_EVENT_RESTART, dev_action_restart },

	{DEV_STATE_RUNNING,        DEV_EVENT_STOP,    dev_action_stop    },
	{DEV_STATE_RUNNING,        DEV_EVENT_RXDOWN,  dev_action_chdown  },
	{DEV_STATE_RUNNING,        DEV_EVENT_TXDOWN,  dev_action_chdown  },
	{DEV_STATE_RUNNING,        DEV_EVENT_TXUP,    fsm_action_nop     },
	{DEV_STATE_RUNNING,        DEV_EVENT_RXUP,    fsm_action_nop     },
 	{DEV_STATE_RUNNING,        DEV_EVENT_RESTART, dev_action_restart },
};

static const int DEV_FSM_LEN = sizeof (dev_fsm) / sizeof (fsm_node);

/**
 * Transmit a packet.
 * This is a helper function for ctc_tx().
 *
 * @param ch Channel to be used for sending.
 * @param skb Pointer to struct sk_buff of packet to send.
 *            The linklevel header has already been set up
 *            by ctc_tx().
 *
 * @return 0 on success, -ERRNO on failure. (Never fails.)
 */
static int
transmit_skb(struct channel *ch, struct sk_buff *skb)
{
	unsigned long saveflags;
	struct ll_header header;
	int rc = 0;

	DBF_TEXT(trace, 5, __FUNCTION__);
	/* we need to acquire the lock for testing the state
	 * otherwise we can have an IRQ changing the state to 
	 * TXIDLE after the test but before acquiring the lock.
	 */
	spin_lock_irqsave(&ch->collect_lock, saveflags);
	if (fsm_getstate(ch->fsm) != CH_STATE_TXIDLE) {
		int l = skb->len + LL_HEADER_LENGTH;

		if (ch->collect_len + l > ch->max_bufsize - 2) {
			spin_unlock_irqrestore(&ch->collect_lock, saveflags);
			return -EBUSY;
		} else {
			atomic_inc(&skb->users);
			header.length = l;
			header.type = skb->protocol;
			header.unused = 0;
			memcpy(skb_push(skb, LL_HEADER_LENGTH), &header,
			       LL_HEADER_LENGTH);
			skb_queue_tail(&ch->collect_queue, skb);
			ch->collect_len += l;
		}
		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
	} else {
		__u16 block_len;
		int ccw_idx;
		struct sk_buff *nskb;
		unsigned long hi;
		spin_unlock_irqrestore(&ch->collect_lock, saveflags);
		/**
		 * Protect skb against beeing free'd by upper
		 * layers.
		 */
		atomic_inc(&skb->users);
		ch->prof.txlen += skb->len;
		header.length = skb->len + LL_HEADER_LENGTH;
		header.type = skb->protocol;
		header.unused = 0;
		memcpy(skb_push(skb, LL_HEADER_LENGTH), &header,
		       LL_HEADER_LENGTH);
		block_len = skb->len + 2;
		*((__u16 *) skb_push(skb, 2)) = block_len;

		/**
		 * IDAL support in CTC is broken, so we have to
		 * care about skb's above 2G ourselves.
		 */
		hi = ((unsigned long) skb->tail + LL_HEADER_LENGTH) >> 31;
		if (hi) {
			nskb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
			if (!nskb) {
				atomic_dec(&skb->users);
				skb_pull(skb, LL_HEADER_LENGTH + 2);
				ctc_clear_busy(ch->netdev);
				return -ENOMEM;
			} else {
				memcpy(skb_put(nskb, skb->len),
				       skb->data, skb->len);
				atomic_inc(&nskb->users);
				atomic_dec(&skb->users);