void ipath_make_ruc_header(struct ipath_ibdev *dev, struct ipath_qp *qp,
			   struct ipath_other_headers *ohdr,
			   u32 bth0, u32 bth2)
{
	u16 lrh0;
	u32 nwords;
	u32 extra_bytes;

	/* Construct the header. */
	extra_bytes = -qp->s_cur_size & 3;
	nwords = (qp->s_cur_size + extra_bytes) >> 2;
	lrh0 = IPATH_LRH_BTH;
	if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
		qp->s_hdrwords += ipath_make_grh(dev, &qp->s_hdr.u.l.grh,
						 &qp->remote_ah_attr.grh,
						 qp->s_hdrwords, nwords);
		lrh0 = IPATH_LRH_GRH;
	}
	lrh0 |= qp->remote_ah_attr.sl << 4;
	qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
	qp->s_hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
	qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
	qp->s_hdr.lrh[3] = cpu_to_be16(dev->dd->ipath_lid);
	bth0 |= ipath_get_pkey(dev->dd, qp->s_pkey_index);
	bth0 |= extra_bytes << 20;
	ohdr->bth[0] = cpu_to_be32(bth0 | (1 << 22));
	ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
	ohdr->bth[2] = cpu_to_be32(bth2);
}
Exemple #2
0
/**
 * ipath_do_ruc_send - perform a send on an RC or UC QP
 * @data: contains a pointer to the QP
 *
 * Process entries in the send work queue until credit or queue is
 * exhausted.  Only allow one CPU to send a packet per QP (tasklet).
 * Otherwise, after we drop the QP s_lock, two threads could send
 * packets out of order.
 */
void ipath_do_ruc_send(unsigned long data)
{
	struct ipath_qp *qp = (struct ipath_qp *)data;
	struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
	unsigned long flags;
	u16 lrh0;
	u32 nwords;
	u32 extra_bytes;
	u32 bth0;
	u32 bth2;
	u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
	struct ipath_other_headers *ohdr;

	if (test_and_set_bit(IPATH_S_BUSY, &qp->s_busy))
		goto bail;

	if (unlikely(qp->remote_ah_attr.dlid == dev->dd->ipath_lid)) {
		ipath_ruc_loopback(qp);
		goto clear;
	}

	ohdr = &qp->s_hdr.u.oth;
	if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
		ohdr = &qp->s_hdr.u.l.oth;

again:
	/* Check for a constructed packet to be sent. */
	if (qp->s_hdrwords != 0) {
		/*
		 * If no PIO bufs are available, return.  An interrupt will
		 * call ipath_ib_piobufavail() when one is available.
		 */
		if (ipath_verbs_send(dev->dd, qp->s_hdrwords,
				     (u32 *) &qp->s_hdr, qp->s_cur_size,
				     qp->s_cur_sge)) {
			ipath_no_bufs_available(qp, dev);
			goto bail;
		}
		dev->n_unicast_xmit++;
		/* Record that we sent the packet and s_hdr is empty. */
		qp->s_hdrwords = 0;
	}

	/*
	 * The lock is needed to synchronize between setting
	 * qp->s_ack_state, resend timer, and post_send().
	 */
	spin_lock_irqsave(&qp->s_lock, flags);

	if (!((qp->ibqp.qp_type == IB_QPT_RC) ?
	       ipath_make_rc_req(qp, ohdr, pmtu, &bth0, &bth2) :
	       ipath_make_uc_req(qp, ohdr, pmtu, &bth0, &bth2))) {
		/*
		 * Clear the busy bit before unlocking to avoid races with
		 * adding new work queue items and then failing to process
		 * them.
		 */
		clear_bit(IPATH_S_BUSY, &qp->s_busy);
		spin_unlock_irqrestore(&qp->s_lock, flags);
		goto bail;
	}

	spin_unlock_irqrestore(&qp->s_lock, flags);

	/* Construct the header. */
	extra_bytes = (4 - qp->s_cur_size) & 3;
	nwords = (qp->s_cur_size + extra_bytes) >> 2;
	lrh0 = IPATH_LRH_BTH;
	if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
		qp->s_hdrwords += ipath_make_grh(dev, &qp->s_hdr.u.l.grh,
						 &qp->remote_ah_attr.grh,
						 qp->s_hdrwords, nwords);
		lrh0 = IPATH_LRH_GRH;
	}
	lrh0 |= qp->remote_ah_attr.sl << 4;
	qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
	qp->s_hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
	qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords +
				       SIZE_OF_CRC);
	qp->s_hdr.lrh[3] = cpu_to_be16(dev->dd->ipath_lid);
	bth0 |= ipath_get_pkey(dev->dd, qp->s_pkey_index);
	bth0 |= extra_bytes << 20;
	ohdr->bth[0] = cpu_to_be32(bth0);
	ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
	ohdr->bth[2] = cpu_to_be32(bth2);

	/* Check for more work to do. */
	goto again;

clear:
	clear_bit(IPATH_S_BUSY, &qp->s_busy);
bail:
	return;
}