void mpc_channel_action()

in net/ctcm_mpc.c [915:1017]

• 87 lines of code
• 19 McCabe index (conditional complexity)

void mpc_channel_action(struct channel *ch, int direction, int action)
{
	struct net_device  *dev  = ch->netdev;
	struct ctcm_priv   *priv = dev->ml_priv;
	struct mpc_group   *grp  = priv->mpcg;

	if (grp == NULL) {
		CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
			"%s(%s): No MPC group",
				CTCM_FUNTAIL, dev->name);
		return;
	}

	CTCM_PR_DEBUG("enter %s: ch=0x%p id=%s\n", __func__, ch, ch->id);

	CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_NOTICE,
		"%s: %i / Grp:%s total_channels=%i, active_channels: "
		"read=%i, write=%i\n", __func__, action,
		fsm_getstate_str(grp->fsm), grp->num_channel_paths,
		grp->active_channels[CTCM_READ],
		grp->active_channels[CTCM_WRITE]);

	if ((action == MPC_CHANNEL_ADD) && (ch->in_mpcgroup == 0)) {
		grp->num_channel_paths++;
		grp->active_channels[direction]++;
		grp->outstanding_xid2++;
		ch->in_mpcgroup = 1;

		if (ch->xid_skb != NULL)
			dev_kfree_skb_any(ch->xid_skb);

		ch->xid_skb = __dev_alloc_skb(MPC_BUFSIZE_DEFAULT,
					GFP_ATOMIC | GFP_DMA);
		if (ch->xid_skb == NULL) {
			CTCM_DBF_TEXT_(MPC_ERROR, CTC_DBF_ERROR,
				"%s(%s): Couldn't alloc ch xid_skb\n",
				CTCM_FUNTAIL, dev->name);
			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
			return;
		}
		ch->xid_skb_data = ch->xid_skb->data;
		ch->xid_th = (struct th_header *)ch->xid_skb->data;
		skb_put(ch->xid_skb, TH_HEADER_LENGTH);
		ch->xid = (struct xid2 *)skb_tail_pointer(ch->xid_skb);
		skb_put(ch->xid_skb, XID2_LENGTH);
		ch->xid_id = skb_tail_pointer(ch->xid_skb);
		ch->xid_skb->data = ch->xid_skb_data;
		skb_reset_tail_pointer(ch->xid_skb);
		ch->xid_skb->len = 0;

		skb_put_data(ch->xid_skb, grp->xid_skb->data,
			     grp->xid_skb->len);

		ch->xid->xid2_dlc_type =
			((CHANNEL_DIRECTION(ch->flags) == CTCM_READ)
				? XID2_READ_SIDE : XID2_WRITE_SIDE);

		if (CHANNEL_DIRECTION(ch->flags) == CTCM_WRITE)
			ch->xid->xid2_buf_len = 0x00;

		ch->xid_skb->data = ch->xid_skb_data;
		skb_reset_tail_pointer(ch->xid_skb);
		ch->xid_skb->len = 0;

		fsm_newstate(ch->fsm, CH_XID0_PENDING);

		if ((grp->active_channels[CTCM_READ] > 0) &&
		    (grp->active_channels[CTCM_WRITE] > 0) &&
			(fsm_getstate(grp->fsm) < MPCG_STATE_XID2INITW)) {
			fsm_newstate(grp->fsm, MPCG_STATE_XID2INITW);
			CTCM_DBF_TEXT_(MPC_SETUP, CTC_DBF_NOTICE,
				"%s: %s: MPC GROUP CHANNELS ACTIVE\n",
						__func__, dev->name);
		}
	} else if ((action == MPC_CHANNEL_REMOVE) &&
			(ch->in_mpcgroup == 1)) {
		ch->in_mpcgroup = 0;
		grp->num_channel_paths--;
		grp->active_channels[direction]--;

		if (ch->xid_skb != NULL)
			dev_kfree_skb_any(ch->xid_skb);
		ch->xid_skb = NULL;

		if (grp->channels_terminating)
					goto done;

		if (((grp->active_channels[CTCM_READ] == 0) &&
					(grp->active_channels[CTCM_WRITE] > 0))
			|| ((grp->active_channels[CTCM_WRITE] == 0) &&
					(grp->active_channels[CTCM_READ] > 0)))
			fsm_event(grp->fsm, MPCG_EVENT_INOP, dev);
	}
done:
	CTCM_DBF_TEXT_(MPC_TRACE, CTC_DBF_DEBUG,
		"exit %s: %i / Grp:%s total_channels=%i, active_channels: "
		"read=%i, write=%i\n", __func__, action,
		fsm_getstate_str(grp->fsm), grp->num_channel_paths,
		grp->active_channels[CTCM_READ],
		grp->active_channels[CTCM_WRITE]);

	CTCM_PR_DEBUG("exit %s: ch=0x%p id=%s\n", __func__, ch, ch->id);
}