ctcmain.c

linux-2.6.15.6

		    (header->length > len)) {
#ifndef DEBUG
		        if (!(ch->logflags & LOG_FLAG_OVERRUN)) {
#endif
				ctc_pr_warn(
					"%s Illegal packet size %d "
					"(beyond the end of received data), "
					"dropping\n", dev->name, header->length);
				ch->logflags |= LOG_FLAG_OVERRUN;
#ifndef DEBUG
			}
#endif
#ifdef DEBUG
			ctc_dump_skb(pskb, -6);
#endif
			privptr->stats.rx_dropped++;
			privptr->stats.rx_length_errors++;
			return;
		}
		skb_put(pskb, header->length);
		pskb->mac.raw = pskb->data;
		len -= header->length;
		skb = dev_alloc_skb(pskb->len);
		if (!skb) {
#ifndef DEBUG
		        if (!(ch->logflags & LOG_FLAG_NOMEM)) {
#endif
				ctc_pr_warn(
					"%s Out of memory in ctc_unpack_skb\n",
					dev->name);
				ch->logflags |= LOG_FLAG_NOMEM;
#ifndef DEBUG
			}
#endif
			privptr->stats.rx_dropped++;
			return;
		}
		memcpy(skb_put(skb, pskb->len), pskb->data, pskb->len);
		skb->mac.raw = skb->data;
		skb->dev = pskb->dev;
		skb->protocol = pskb->protocol;
		pskb->ip_summed = CHECKSUM_UNNECESSARY;
		if (ch->protocol == CTC_PROTO_LINUX_TTY)
			ctc_tty_netif_rx(skb);
		else
			netif_rx_ni(skb);
		/**
		 * Successful rx; reset logflags
		 */
		ch->logflags = 0;
		dev->last_rx = jiffies;
		privptr->stats.rx_packets++;
		privptr->stats.rx_bytes += skb->len;
		if (len > 0) {
			skb_pull(pskb, header->length);
			if (skb_tailroom(pskb) < LL_HEADER_LENGTH) {
#ifndef DEBUG
				if (!(ch->logflags & LOG_FLAG_OVERRUN)) {
#endif
					ctc_pr_warn(
						"%s Overrun in ctc_unpack_skb\n",
						dev->name);
					ch->logflags |= LOG_FLAG_OVERRUN;
#ifndef DEBUG
				}
#endif
				return;
			}
			skb_put(pskb, LL_HEADER_LENGTH);
		}
	}
}

/**
 * Check return code of a preceeding ccw_device call, halt_IO etc...
 *
 * @param ch          The channel, the error belongs to.
 * @param return_code The error code to inspect.
 */
static void inline
ccw_check_return_code(struct channel *ch, int return_code, char *msg)
{
	DBF_TEXT(trace, 5, __FUNCTION__);
	switch (return_code) {
		case 0:
			fsm_event(ch->fsm, CH_EVENT_IO_SUCCESS, ch);
			break;
		case -EBUSY:
			ctc_pr_warn("%s (%s): Busy !\n", ch->id, msg);
			fsm_event(ch->fsm, CH_EVENT_IO_EBUSY, ch);
			break;
		case -ENODEV:
			ctc_pr_emerg("%s (%s): Invalid device called for IO\n",
				     ch->id, msg);
			fsm_event(ch->fsm, CH_EVENT_IO_ENODEV, ch);
			break;
		case -EIO:
			ctc_pr_emerg("%s (%s): Status pending... \n",
				     ch->id, msg);
			fsm_event(ch->fsm, CH_EVENT_IO_EIO, ch);
			break;
		default:
			ctc_pr_emerg("%s (%s): Unknown error in do_IO %04x\n",
				     ch->id, msg, return_code);
			fsm_event(ch->fsm, CH_EVENT_IO_UNKNOWN, ch);
	}
}

/**
 * Check sense of a unit check.
 *
 * @param ch    The channel, the sense code belongs to.
 * @param sense The sense code to inspect.
 */
static void inline
ccw_unit_check(struct channel *ch, unsigned char sense)
{
	DBF_TEXT(trace, 5, __FUNCTION__);
	if (sense & SNS0_INTERVENTION_REQ) {
		if (sense & 0x01) {
			if (ch->protocol != CTC_PROTO_LINUX_TTY)
				ctc_pr_debug("%s: Interface disc. or Sel. reset "
					"(remote)\n", ch->id);
			fsm_event(ch->fsm, CH_EVENT_UC_RCRESET, ch);
		} else {
			ctc_pr_debug("%s: System reset (remote)\n", ch->id);
			fsm_event(ch->fsm, CH_EVENT_UC_RSRESET, ch);
		}
	} else if (sense & SNS0_EQUIPMENT_CHECK) {
		if (sense & SNS0_BUS_OUT_CHECK) {
			ctc_pr_warn("%s: Hardware malfunction (remote)\n",
				    ch->id);
			fsm_event(ch->fsm, CH_EVENT_UC_HWFAIL, ch);
		} else {
			ctc_pr_warn("%s: Read-data parity error (remote)\n",
				    ch->id);
			fsm_event(ch->fsm, CH_EVENT_UC_RXPARITY, ch);
		}
	} else if (sense & SNS0_BUS_OUT_CHECK) {
		if (sense & 0x04) {
			ctc_pr_warn("%s: Data-streaming timeout)\n", ch->id);
			fsm_event(ch->fsm, CH_EVENT_UC_TXTIMEOUT, ch);
		} else {
			ctc_pr_warn("%s: Data-transfer parity error\n", ch->id);
			fsm_event(ch->fsm, CH_EVENT_UC_TXPARITY, ch);
		}
	} else if (sense & SNS0_CMD_REJECT) {
		ctc_pr_warn("%s: Command reject\n", ch->id);
	} else if (sense == 0) {
		ctc_pr_debug("%s: Unit check ZERO\n", ch->id);
		fsm_event(ch->fsm, CH_EVENT_UC_ZERO, ch);
	} else {
		ctc_pr_warn("%s: Unit Check with sense code: %02x\n",
			    ch->id, sense);
		fsm_event(ch->fsm, CH_EVENT_UC_UNKNOWN, ch);
	}
}

static void
ctc_purge_skb_queue(struct sk_buff_head *q)
{
	struct sk_buff *skb;

	DBF_TEXT(trace, 5, __FUNCTION__);

	while ((skb = skb_dequeue(q))) {
		atomic_dec(&skb->users);
		dev_kfree_skb_irq(skb);
	}
}

static __inline__ int
ctc_checkalloc_buffer(struct channel *ch, int warn)
{
	DBF_TEXT(trace, 5, __FUNCTION__);
	if ((ch->trans_skb == NULL) ||
	    (ch->flags & CHANNEL_FLAGS_BUFSIZE_CHANGED)) {
		if (ch->trans_skb != NULL)
			dev_kfree_skb(ch->trans_skb);
		clear_normalized_cda(&ch->ccw[1]);
		ch->trans_skb = __dev_alloc_skb(ch->max_bufsize,
						GFP_ATOMIC | GFP_DMA);
		if (ch->trans_skb == NULL) {
			if (warn)
				ctc_pr_warn(
					"%s: Couldn't alloc %s trans_skb\n",
					ch->id,
					(CHANNEL_DIRECTION(ch->flags) == READ) ?
					"RX" : "TX");
			return -ENOMEM;
		}
		ch->ccw[1].count = ch->max_bufsize;
		if (set_normalized_cda(&ch->ccw[1], ch->trans_skb->data)) {
			dev_kfree_skb(ch->trans_skb);
			ch->trans_skb = NULL;
			if (warn)
				ctc_pr_warn(
					"%s: set_normalized_cda for %s "
					"trans_skb failed, dropping packets\n",
					ch->id,
					(CHANNEL_DIRECTION(ch->flags) == READ) ?
					"RX" : "TX");
			return -ENOMEM;
		}
		ch->ccw[1].count = 0;
		ch->trans_skb_data = ch->trans_skb->data;
		ch->flags &= ~CHANNEL_FLAGS_BUFSIZE_CHANGED;
	}
	return 0;
}

/**
 * Dummy NOP action for statemachines
 */
static void
fsm_action_nop(fsm_instance * fi, int event, void *arg)
{
}

/**
 * Actions for channel - statemachines.
 *****************************************************************************/

/**
 * Normal data has been send. Free the corresponding
 * skb (it's in io_queue), reset dev->tbusy and
 * revert to idle state.
 *
 * @param fi    An instance of a channel statemachine.
 * @param event The event, just happened.
 * @param arg   Generic pointer, casted from channel * upon call.
 */
static void
ch_action_txdone(fsm_instance * fi, int event, void *arg)
{
	struct channel *ch = (struct channel *) arg;
	struct net_device *dev = ch->netdev;
	struct ctc_priv *privptr = dev->priv;
	struct sk_buff *skb;
	int first = 1;
	int i;
	unsigned long duration;
	struct timespec done_stamp = xtime;

	DBF_TEXT(trace, 4, __FUNCTION__);

	duration =
	    (done_stamp.tv_sec - ch->prof.send_stamp.tv_sec) * 1000000 +
	    (done_stamp.tv_nsec - ch->prof.send_stamp.tv_nsec) / 1000;
	if (duration > ch->prof.tx_time)
		ch->prof.tx_time = duration;

	if (ch->irb->scsw.count != 0)
		ctc_pr_debug("%s: TX not complete, remaining %d bytes\n",
			     dev->name, ch->irb->scsw.count);
	fsm_deltimer(&ch->timer);
	while ((skb = skb_dequeue(&ch->io_queue))) {
		privptr->stats.tx_packets++;
		privptr->stats.tx_bytes += skb->len - LL_HEADER_LENGTH;
		if (first) {
			privptr->stats.tx_bytes += 2;
			first = 0;
		}
		atomic_dec(&skb->users);
		dev_kfree_skb_irq(skb);
	}
	spin_lock(&ch->collect_lock);
	clear_normalized_cda(&ch->ccw[4]);
	if (ch->collect_len > 0) {
		int rc;

		if (ctc_checkalloc_buffer(ch, 1)) {
			spin_unlock(&ch->collect_lock);
			return;
		}
		ch->trans_skb->tail = ch->trans_skb->data = ch->trans_skb_data;
		ch->trans_skb->len = 0;
		if (ch->prof.maxmulti < (ch->collect_len + 2))
			ch->prof.maxmulti = ch->collect_len + 2;
		if (ch->prof.maxcqueue < skb_queue_len(&ch->collect_queue))
			ch->prof.maxcqueue = skb_queue_len(&ch->collect_queue);
		*((__u16 *) skb_put(ch->trans_skb, 2)) = ch->collect_len + 2;
		i = 0;
		while ((skb = skb_dequeue(&ch->collect_queue))) {
			memcpy(skb_put(ch->trans_skb, skb->len), skb->data,
			       skb->len);
			privptr->stats.tx_packets++;
			privptr->stats.tx_bytes += skb->len - LL_HEADER_LENGTH;
			atomic_dec(&skb->users);
			dev_kfree_skb_irq(skb);
			i++;
		}
		ch->collect_len = 0;
		spin_unlock(&ch->collect_lock);
		ch->ccw[1].count = ch->trans_skb->len;
		fsm_addtimer(&ch->timer, CTC_TIMEOUT_5SEC, CH_EVENT_TIMER, ch);
		ch->prof.send_stamp = xtime;
		rc = ccw_device_start(ch->cdev, &ch->ccw[0],
				      (unsigned long) ch, 0xff, 0);
		ch->prof.doios_multi++;
		if (rc != 0) {
			privptr->stats.tx_dropped += i;
			privptr->stats.tx_errors += i;
			fsm_deltimer(&ch->timer);
			ccw_check_return_code(ch, rc, "chained TX");
		}
	} else {
		spin_unlock(&ch->collect_lock);
		fsm_newstate(fi, CH_STATE_TXIDLE);
	}
	ctc_clear_busy(dev);
}

/**
 * Initial data is sent.
 * Notify device statemachine that we are up and
 * running.
 *
 * @param fi    An instance of a channel statemachine.
 * @param event The event, just happened.
 * @param arg   Generic pointer, casted from channel * upon call.
 */
static void
ch_action_txidle(fsm_instance * fi, int event, void *arg)
{
	struct channel *ch = (struct channel *) arg;

	DBF_TEXT(trace, 4, __FUNCTION__);
	fsm_deltimer(&ch->timer);
	fsm_newstate(fi, CH_STATE_TXIDLE);
	fsm_event(((struct ctc_priv *) ch->netdev->priv)->fsm, DEV_EVENT_TXUP,
		  ch->netdev);
}

/**
 * Got normal data, check for sanity, queue it up, allocate new buffer
 * trigger bottom half, and initiate next read.
 *
 * @param fi    An instance of a channel statemachine.
 * @param event The event, just happened.
 * @param arg   Generic pointer, casted from channel * upon call.
 */
static void
ch_action_rx(fsm_instance * fi, int event, void *arg)
{
	struct channel *ch = (struct channel *) arg;
	struct net_device *dev = ch->netdev;
	struct ctc_priv *privptr = dev->priv;
	int len = ch->max_bufsize - ch->irb->scsw.count;
	struct sk_buff *skb = ch->trans_skb;
	__u16 block_len = *((__u16 *) skb->data);
	int check_len;
	int rc;

	DBF_TEXT(trace, 4, __FUNCTION__);
	fsm_deltimer(&ch->timer);
	if (len < 8) {
		ctc_pr_debug("%s: got packet with length %d < 8\n",
			     dev->name, len);
		privptr->stats.rx_dropped++;
		privptr->stats.rx_length_errors++;
		goto again;
	}
	if (len > ch->max_bufsize) {
		ctc_pr_debug("%s: got packet with length %d > %d\n",
			     dev->name, len, ch->max_bufsize);
		privptr->stats.rx_dropped++;
		privptr->stats.rx_length_errors++;
		goto again;
	}

	/**
	 * VM TCP seems to have a bug sending 2 trailing bytes of garbage.
	 */
	switch (ch->protocol) {
		case CTC_PROTO_S390:
		case CTC_PROTO_OS390:
			check_len = block_len + 2;
			break;
		default:
			check_len = block_len;
			break;
	}
	if ((len < block_len) || (len > check_len)) {
		ctc_pr_debug("%s: got block length %d != rx length %d\n",
			     dev->name, block_len, len);
#ifdef DEBUG
		ctc_dump_skb(skb, 0);
#endif
		*((__u16 *) skb->data) = len;
		privptr->stats.rx_dropped++;
		privptr->stats.rx_length_errors++;
		goto again;
	}
	block_len -= 2;
	if (block_len > 0) {
		*((__u16 *) skb->data) = block_len;
		ctc_unpack_skb(ch, skb);
	}
 again:
	skb->data = skb->tail = ch->trans_skb_data;
	skb->len = 0;
	if (ctc_checkalloc_buffer(ch, 1))
		return;
	ch->ccw[1].count = ch->max_bufsize;
	rc = ccw_device_start(ch->cdev, &ch->ccw[0], (unsigned long) ch, 0xff, 0);
	if (rc != 0)
		ccw_check_return_code(ch, rc, "normal RX");
}

static void ch_action_rxidle(fsm_instance * fi, int event, void *arg);

/**
 * Initialize connection by sending a __u16 of value 0.
 *
 * @param fi    An instance of a channel statemachine.
 * @param event The event, just happened.
 * @param arg   Generic pointer, casted from channel * upon call.
 */
static void
ch_action_firstio(fsm_instance * fi, int event, void *arg)
{
	struct channel *ch = (struct channel *) arg;
	int rc;

	DBF_TEXT(trace, 4, __FUNCTION__);

	if (fsm_getstate(fi) == CH_STATE_TXIDLE)
		ctc_pr_debug("%s: remote side issued READ?, init ...\n", ch->id);
	fsm_deltimer(&ch->timer);
	if (ctc_checkalloc_buffer(ch, 1))
		return;
	if ((fsm_getstate(fi) == CH_STATE_SETUPWAIT) &&
	    (ch->protocol == CTC_PROTO_OS390)) {
		/* OS/390 resp. z/OS */
		if (CHANNEL_DIRECTION(ch->flags) == READ) {
			*((__u16 *) ch->trans_skb->data) = CTC_INITIAL_BLOCKLEN;
			fsm_addtimer(&ch->timer, CTC_TIMEOUT_5SEC,
				     CH_EVENT_TIMER, ch);
			ch_action_rxidle(fi, event, arg);
		} else {
			struct net_device *dev = ch->netdev;
			fsm_newstate(fi, CH_STATE_TXIDLE);
			fsm_event(((struct ctc_priv *) dev->priv)->fsm,
				  DEV_EVENT_TXUP, dev);
		}
		return;
	}

	/**
	 * Don磘 setup a timer for receiving the initial RX frame
	 * if in compatibility mode, since VM TCP delays the initial
	 * frame until it has some data to send.
	 */