-
-/**
- * ipath_make_grh - construct a GRH header
- * @dev: a pointer to the ipath device
- * @hdr: a pointer to the GRH header being constructed
- * @grh: the global route address to send to
- * @hwords: the number of 32 bit words of header being sent
- * @nwords: the number of 32 bit words of data being sent
- *
- * Return the size of the header in 32 bit words.
- */
-u32 ipath_make_grh(struct ipath_ibdev *dev, struct ib_grh *hdr,
- struct ib_global_route *grh, u32 hwords, u32 nwords)
-{
- hdr->version_tclass_flow =
- cpu_to_be32((6 << 28) |
- (grh->traffic_class << 20) |
- grh->flow_label);
- hdr->paylen = cpu_to_be16((hwords - 2 + nwords + SIZE_OF_CRC) << 2);
- /* next_hdr is defined by C8-7 in ch. 8.4.1 */
- hdr->next_hdr = 0x1B;
- hdr->hop_limit = grh->hop_limit;
- /* The SGID is 32-bit aligned. */
- hdr->sgid.global.subnet_prefix = dev->gid_prefix;
- hdr->sgid.global.interface_id = ipath_layer_get_guid(dev->dd);
- hdr->dgid = grh->dgid;
-
- /* GRH header size in 32-bit words. */
- return sizeof(struct ib_grh) / sizeof(u32);
-}
-
-/**
- * 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_flags))
- goto bail;
-
- if (unlikely(qp->remote_ah_attr.dlid ==
- ipath_layer_get_lid(dev->dd))) {
- 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);
-
- /* Sending responses has higher priority over sending requests. */
- if (qp->s_ack_state != IB_OPCODE_RC_ACKNOWLEDGE &&
- (bth0 = ipath_make_rc_ack(qp, ohdr, pmtu)) != 0)
- bth2 = qp->s_ack_psn++ & IPATH_PSN_MASK;
- else 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_flags);
- 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(ipath_layer_get_lid(dev->dd));
- bth0 |= ipath_layer_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_flags);
-bail:
- return;
-}