| /* |
| * Copyright(c) 2015, 2016 Intel Corporation. |
| * |
| * This file is provided under a dual BSD/GPLv2 license. When using or |
| * redistributing this file, you may do so under either license. |
| * |
| * GPL LICENSE SUMMARY |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of version 2 of the GNU General Public License as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * BSD LICENSE |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * - Neither the name of Intel Corporation nor the names of its |
| * contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include <linux/io.h> |
| #include <rdma/rdma_vt.h> |
| #include <rdma/rdmavt_qp.h> |
| |
| #include "hfi.h" |
| #include "qp.h" |
| #include "verbs_txreq.h" |
| #include "trace.h" |
| |
| /* cut down ridiculously long IB macro names */ |
| #define OP(x) RC_OP(x) |
| |
| static u32 restart_sge(struct rvt_sge_state *ss, struct rvt_swqe *wqe, |
| u32 psn, u32 pmtu) |
| { |
| u32 len; |
| |
| len = delta_psn(psn, wqe->psn) * pmtu; |
| ss->sge = wqe->sg_list[0]; |
| ss->sg_list = wqe->sg_list + 1; |
| ss->num_sge = wqe->wr.num_sge; |
| ss->total_len = wqe->length; |
| hfi1_skip_sge(ss, len, false); |
| return wqe->length - len; |
| } |
| |
| /** |
| * make_rc_ack - construct a response packet (ACK, NAK, or RDMA read) |
| * @dev: the device for this QP |
| * @qp: a pointer to the QP |
| * @ohdr: a pointer to the IB header being constructed |
| * @ps: the xmit packet state |
| * |
| * Return 1 if constructed; otherwise, return 0. |
| * Note that we are in the responder's side of the QP context. |
| * Note the QP s_lock must be held. |
| */ |
| static int make_rc_ack(struct hfi1_ibdev *dev, struct rvt_qp *qp, |
| struct ib_other_headers *ohdr, |
| struct hfi1_pkt_state *ps) |
| { |
| struct rvt_ack_entry *e; |
| u32 hwords; |
| u32 len; |
| u32 bth0; |
| u32 bth2; |
| int middle = 0; |
| u32 pmtu = qp->pmtu; |
| struct hfi1_qp_priv *priv = qp->priv; |
| |
| lockdep_assert_held(&qp->s_lock); |
| /* Don't send an ACK if we aren't supposed to. */ |
| if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) |
| goto bail; |
| |
| /* header size in 32-bit words LRH+BTH = (8+12)/4. */ |
| hwords = 5; |
| |
| switch (qp->s_ack_state) { |
| case OP(RDMA_READ_RESPONSE_LAST): |
| case OP(RDMA_READ_RESPONSE_ONLY): |
| e = &qp->s_ack_queue[qp->s_tail_ack_queue]; |
| if (e->rdma_sge.mr) { |
| rvt_put_mr(e->rdma_sge.mr); |
| e->rdma_sge.mr = NULL; |
| } |
| /* FALLTHROUGH */ |
| case OP(ATOMIC_ACKNOWLEDGE): |
| /* |
| * We can increment the tail pointer now that the last |
| * response has been sent instead of only being |
| * constructed. |
| */ |
| if (++qp->s_tail_ack_queue > HFI1_MAX_RDMA_ATOMIC) |
| qp->s_tail_ack_queue = 0; |
| /* FALLTHROUGH */ |
| case OP(SEND_ONLY): |
| case OP(ACKNOWLEDGE): |
| /* Check for no next entry in the queue. */ |
| if (qp->r_head_ack_queue == qp->s_tail_ack_queue) { |
| if (qp->s_flags & RVT_S_ACK_PENDING) |
| goto normal; |
| goto bail; |
| } |
| |
| e = &qp->s_ack_queue[qp->s_tail_ack_queue]; |
| if (e->opcode == OP(RDMA_READ_REQUEST)) { |
| /* |
| * If a RDMA read response is being resent and |
| * we haven't seen the duplicate request yet, |
| * then stop sending the remaining responses the |
| * responder has seen until the requester re-sends it. |
| */ |
| len = e->rdma_sge.sge_length; |
| if (len && !e->rdma_sge.mr) { |
| qp->s_tail_ack_queue = qp->r_head_ack_queue; |
| goto bail; |
| } |
| /* Copy SGE state in case we need to resend */ |
| ps->s_txreq->mr = e->rdma_sge.mr; |
| if (ps->s_txreq->mr) |
| rvt_get_mr(ps->s_txreq->mr); |
| qp->s_ack_rdma_sge.sge = e->rdma_sge; |
| qp->s_ack_rdma_sge.num_sge = 1; |
| ps->s_txreq->ss = &qp->s_ack_rdma_sge; |
| if (len > pmtu) { |
| len = pmtu; |
| qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST); |
| } else { |
| qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY); |
| e->sent = 1; |
| } |
| ohdr->u.aeth = rvt_compute_aeth(qp); |
| hwords++; |
| qp->s_ack_rdma_psn = e->psn; |
| bth2 = mask_psn(qp->s_ack_rdma_psn++); |
| } else { |
| /* COMPARE_SWAP or FETCH_ADD */ |
| ps->s_txreq->ss = NULL; |
| len = 0; |
| qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE); |
| ohdr->u.at.aeth = rvt_compute_aeth(qp); |
| ib_u64_put(e->atomic_data, &ohdr->u.at.atomic_ack_eth); |
| hwords += sizeof(ohdr->u.at) / sizeof(u32); |
| bth2 = mask_psn(e->psn); |
| e->sent = 1; |
| } |
| bth0 = qp->s_ack_state << 24; |
| break; |
| |
| case OP(RDMA_READ_RESPONSE_FIRST): |
| qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE); |
| /* FALLTHROUGH */ |
| case OP(RDMA_READ_RESPONSE_MIDDLE): |
| ps->s_txreq->ss = &qp->s_ack_rdma_sge; |
| ps->s_txreq->mr = qp->s_ack_rdma_sge.sge.mr; |
| if (ps->s_txreq->mr) |
| rvt_get_mr(ps->s_txreq->mr); |
| len = qp->s_ack_rdma_sge.sge.sge_length; |
| if (len > pmtu) { |
| len = pmtu; |
| middle = HFI1_CAP_IS_KSET(SDMA_AHG); |
| } else { |
| ohdr->u.aeth = rvt_compute_aeth(qp); |
| hwords++; |
| qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST); |
| e = &qp->s_ack_queue[qp->s_tail_ack_queue]; |
| e->sent = 1; |
| } |
| bth0 = qp->s_ack_state << 24; |
| bth2 = mask_psn(qp->s_ack_rdma_psn++); |
| break; |
| |
| default: |
| normal: |
| /* |
| * Send a regular ACK. |
| * Set the s_ack_state so we wait until after sending |
| * the ACK before setting s_ack_state to ACKNOWLEDGE |
| * (see above). |
| */ |
| qp->s_ack_state = OP(SEND_ONLY); |
| qp->s_flags &= ~RVT_S_ACK_PENDING; |
| ps->s_txreq->ss = NULL; |
| if (qp->s_nak_state) |
| ohdr->u.aeth = |
| cpu_to_be32((qp->r_msn & RVT_MSN_MASK) | |
| (qp->s_nak_state << |
| RVT_AETH_CREDIT_SHIFT)); |
| else |
| ohdr->u.aeth = rvt_compute_aeth(qp); |
| hwords++; |
| len = 0; |
| bth0 = OP(ACKNOWLEDGE) << 24; |
| bth2 = mask_psn(qp->s_ack_psn); |
| } |
| qp->s_rdma_ack_cnt++; |
| qp->s_hdrwords = hwords; |
| ps->s_txreq->sde = priv->s_sde; |
| ps->s_txreq->s_cur_size = len; |
| hfi1_make_ruc_header(qp, ohdr, bth0, bth2, middle, ps); |
| /* pbc */ |
| ps->s_txreq->hdr_dwords = qp->s_hdrwords + 2; |
| return 1; |
| |
| bail: |
| qp->s_ack_state = OP(ACKNOWLEDGE); |
| /* |
| * Ensure s_rdma_ack_cnt changes are committed prior to resetting |
| * RVT_S_RESP_PENDING |
| */ |
| smp_wmb(); |
| qp->s_flags &= ~(RVT_S_RESP_PENDING |
| | RVT_S_ACK_PENDING |
| | RVT_S_AHG_VALID); |
| return 0; |
| } |
| |
| /** |
| * hfi1_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC) |
| * @qp: a pointer to the QP |
| * |
| * Assumes s_lock is held. |
| * |
| * Return 1 if constructed; otherwise, return 0. |
| */ |
| int hfi1_make_rc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps) |
| { |
| struct hfi1_qp_priv *priv = qp->priv; |
| struct hfi1_ibdev *dev = to_idev(qp->ibqp.device); |
| struct ib_other_headers *ohdr; |
| struct rvt_sge_state *ss; |
| struct rvt_swqe *wqe; |
| /* header size in 32-bit words LRH+BTH = (8+12)/4. */ |
| u32 hwords = 5; |
| u32 len; |
| u32 bth0 = 0; |
| u32 bth2; |
| u32 pmtu = qp->pmtu; |
| char newreq; |
| int middle = 0; |
| int delta; |
| |
| lockdep_assert_held(&qp->s_lock); |
| ps->s_txreq = get_txreq(ps->dev, qp); |
| if (IS_ERR(ps->s_txreq)) |
| goto bail_no_tx; |
| |
| ohdr = &ps->s_txreq->phdr.hdr.u.oth; |
| if (qp->remote_ah_attr.ah_flags & IB_AH_GRH) |
| ohdr = &ps->s_txreq->phdr.hdr.u.l.oth; |
| |
| /* Sending responses has higher priority over sending requests. */ |
| if ((qp->s_flags & RVT_S_RESP_PENDING) && |
| make_rc_ack(dev, qp, ohdr, ps)) |
| return 1; |
| |
| if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) { |
| if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND)) |
| goto bail; |
| /* We are in the error state, flush the work request. */ |
| smp_read_barrier_depends(); /* see post_one_send() */ |
| if (qp->s_last == READ_ONCE(qp->s_head)) |
| goto bail; |
| /* If DMAs are in progress, we can't flush immediately. */ |
| if (iowait_sdma_pending(&priv->s_iowait)) { |
| qp->s_flags |= RVT_S_WAIT_DMA; |
| goto bail; |
| } |
| clear_ahg(qp); |
| wqe = rvt_get_swqe_ptr(qp, qp->s_last); |
| hfi1_send_complete(qp, wqe, qp->s_last != qp->s_acked ? |
| IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR); |
| /* will get called again */ |
| goto done_free_tx; |
| } |
| |
| if (qp->s_flags & (RVT_S_WAIT_RNR | RVT_S_WAIT_ACK)) |
| goto bail; |
| |
| if (cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) { |
| if (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) { |
| qp->s_flags |= RVT_S_WAIT_PSN; |
| goto bail; |
| } |
| qp->s_sending_psn = qp->s_psn; |
| qp->s_sending_hpsn = qp->s_psn - 1; |
| } |
| |
| /* Send a request. */ |
| wqe = rvt_get_swqe_ptr(qp, qp->s_cur); |
| switch (qp->s_state) { |
| default: |
| if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK)) |
| goto bail; |
| /* |
| * Resend an old request or start a new one. |
| * |
| * We keep track of the current SWQE so that |
| * we don't reset the "furthest progress" state |
| * if we need to back up. |
| */ |
| newreq = 0; |
| if (qp->s_cur == qp->s_tail) { |
| /* Check if send work queue is empty. */ |
| smp_read_barrier_depends(); /* see post_one_send() */ |
| if (qp->s_tail == READ_ONCE(qp->s_head)) { |
| clear_ahg(qp); |
| goto bail; |
| } |
| /* |
| * If a fence is requested, wait for previous |
| * RDMA read and atomic operations to finish. |
| */ |
| if ((wqe->wr.send_flags & IB_SEND_FENCE) && |
| qp->s_num_rd_atomic) { |
| qp->s_flags |= RVT_S_WAIT_FENCE; |
| goto bail; |
| } |
| /* |
| * Local operations are processed immediately |
| * after all prior requests have completed |
| */ |
| if (wqe->wr.opcode == IB_WR_REG_MR || |
| wqe->wr.opcode == IB_WR_LOCAL_INV) { |
| int local_ops = 0; |
| int err = 0; |
| |
| if (qp->s_last != qp->s_cur) |
| goto bail; |
| if (++qp->s_cur == qp->s_size) |
| qp->s_cur = 0; |
| if (++qp->s_tail == qp->s_size) |
| qp->s_tail = 0; |
| if (!(wqe->wr.send_flags & |
| RVT_SEND_COMPLETION_ONLY)) { |
| err = rvt_invalidate_rkey( |
| qp, |
| wqe->wr.ex.invalidate_rkey); |
| local_ops = 1; |
| } |
| hfi1_send_complete(qp, wqe, |
| err ? IB_WC_LOC_PROT_ERR |
| : IB_WC_SUCCESS); |
| if (local_ops) |
| atomic_dec(&qp->local_ops_pending); |
| qp->s_hdrwords = 0; |
| goto done_free_tx; |
| } |
| |
| newreq = 1; |
| qp->s_psn = wqe->psn; |
| } |
| /* |
| * Note that we have to be careful not to modify the |
| * original work request since we may need to resend |
| * it. |
| */ |
| len = wqe->length; |
| ss = &qp->s_sge; |
| bth2 = mask_psn(qp->s_psn); |
| switch (wqe->wr.opcode) { |
| case IB_WR_SEND: |
| case IB_WR_SEND_WITH_IMM: |
| case IB_WR_SEND_WITH_INV: |
| /* If no credit, return. */ |
| if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) && |
| rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) { |
| qp->s_flags |= RVT_S_WAIT_SSN_CREDIT; |
| goto bail; |
| } |
| if (len > pmtu) { |
| qp->s_state = OP(SEND_FIRST); |
| len = pmtu; |
| break; |
| } |
| if (wqe->wr.opcode == IB_WR_SEND) { |
| qp->s_state = OP(SEND_ONLY); |
| } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) { |
| qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE); |
| /* Immediate data comes after the BTH */ |
| ohdr->u.imm_data = wqe->wr.ex.imm_data; |
| hwords += 1; |
| } else { |
| qp->s_state = OP(SEND_ONLY_WITH_INVALIDATE); |
| /* Invalidate rkey comes after the BTH */ |
| ohdr->u.ieth = cpu_to_be32( |
| wqe->wr.ex.invalidate_rkey); |
| hwords += 1; |
| } |
| if (wqe->wr.send_flags & IB_SEND_SOLICITED) |
| bth0 |= IB_BTH_SOLICITED; |
| bth2 |= IB_BTH_REQ_ACK; |
| if (++qp->s_cur == qp->s_size) |
| qp->s_cur = 0; |
| break; |
| |
| case IB_WR_RDMA_WRITE: |
| if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT)) |
| qp->s_lsn++; |
| /* FALLTHROUGH */ |
| case IB_WR_RDMA_WRITE_WITH_IMM: |
| /* If no credit, return. */ |
| if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) && |
| rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) { |
| qp->s_flags |= RVT_S_WAIT_SSN_CREDIT; |
| goto bail; |
| } |
| put_ib_reth_vaddr( |
| wqe->rdma_wr.remote_addr, |
| &ohdr->u.rc.reth); |
| ohdr->u.rc.reth.rkey = |
| cpu_to_be32(wqe->rdma_wr.rkey); |
| ohdr->u.rc.reth.length = cpu_to_be32(len); |
| hwords += sizeof(struct ib_reth) / sizeof(u32); |
| if (len > pmtu) { |
| qp->s_state = OP(RDMA_WRITE_FIRST); |
| len = pmtu; |
| break; |
| } |
| if (wqe->wr.opcode == IB_WR_RDMA_WRITE) { |
| qp->s_state = OP(RDMA_WRITE_ONLY); |
| } else { |
| qp->s_state = |
| OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE); |
| /* Immediate data comes after RETH */ |
| ohdr->u.rc.imm_data = wqe->wr.ex.imm_data; |
| hwords += 1; |
| if (wqe->wr.send_flags & IB_SEND_SOLICITED) |
| bth0 |= IB_BTH_SOLICITED; |
| } |
| bth2 |= IB_BTH_REQ_ACK; |
| if (++qp->s_cur == qp->s_size) |
| qp->s_cur = 0; |
| break; |
| |
| case IB_WR_RDMA_READ: |
| /* |
| * Don't allow more operations to be started |
| * than the QP limits allow. |
| */ |
| if (newreq) { |
| if (qp->s_num_rd_atomic >= |
| qp->s_max_rd_atomic) { |
| qp->s_flags |= RVT_S_WAIT_RDMAR; |
| goto bail; |
| } |
| qp->s_num_rd_atomic++; |
| if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT)) |
| qp->s_lsn++; |
| } |
| put_ib_reth_vaddr( |
| wqe->rdma_wr.remote_addr, |
| &ohdr->u.rc.reth); |
| ohdr->u.rc.reth.rkey = |
| cpu_to_be32(wqe->rdma_wr.rkey); |
| ohdr->u.rc.reth.length = cpu_to_be32(len); |
| qp->s_state = OP(RDMA_READ_REQUEST); |
| hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32); |
| ss = NULL; |
| len = 0; |
| bth2 |= IB_BTH_REQ_ACK; |
| if (++qp->s_cur == qp->s_size) |
| qp->s_cur = 0; |
| break; |
| |
| case IB_WR_ATOMIC_CMP_AND_SWP: |
| case IB_WR_ATOMIC_FETCH_AND_ADD: |
| /* |
| * Don't allow more operations to be started |
| * than the QP limits allow. |
| */ |
| if (newreq) { |
| if (qp->s_num_rd_atomic >= |
| qp->s_max_rd_atomic) { |
| qp->s_flags |= RVT_S_WAIT_RDMAR; |
| goto bail; |
| } |
| qp->s_num_rd_atomic++; |
| if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT)) |
| qp->s_lsn++; |
| } |
| if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP) { |
| qp->s_state = OP(COMPARE_SWAP); |
| put_ib_ateth_swap(wqe->atomic_wr.swap, |
| &ohdr->u.atomic_eth); |
| put_ib_ateth_compare(wqe->atomic_wr.compare_add, |
| &ohdr->u.atomic_eth); |
| } else { |
| qp->s_state = OP(FETCH_ADD); |
| put_ib_ateth_swap(wqe->atomic_wr.compare_add, |
| &ohdr->u.atomic_eth); |
| put_ib_ateth_compare(0, &ohdr->u.atomic_eth); |
| } |
| put_ib_ateth_vaddr(wqe->atomic_wr.remote_addr, |
| &ohdr->u.atomic_eth); |
| ohdr->u.atomic_eth.rkey = cpu_to_be32( |
| wqe->atomic_wr.rkey); |
| hwords += sizeof(struct ib_atomic_eth) / sizeof(u32); |
| ss = NULL; |
| len = 0; |
| bth2 |= IB_BTH_REQ_ACK; |
| if (++qp->s_cur == qp->s_size) |
| qp->s_cur = 0; |
| break; |
| |
| default: |
| goto bail; |
| } |
| qp->s_sge.sge = wqe->sg_list[0]; |
| qp->s_sge.sg_list = wqe->sg_list + 1; |
| qp->s_sge.num_sge = wqe->wr.num_sge; |
| qp->s_sge.total_len = wqe->length; |
| qp->s_len = wqe->length; |
| if (newreq) { |
| qp->s_tail++; |
| if (qp->s_tail >= qp->s_size) |
| qp->s_tail = 0; |
| } |
| if (wqe->wr.opcode == IB_WR_RDMA_READ) |
| qp->s_psn = wqe->lpsn + 1; |
| else |
| qp->s_psn++; |
| break; |
| |
| case OP(RDMA_READ_RESPONSE_FIRST): |
| /* |
| * qp->s_state is normally set to the opcode of the |
| * last packet constructed for new requests and therefore |
| * is never set to RDMA read response. |
| * RDMA_READ_RESPONSE_FIRST is used by the ACK processing |
| * thread to indicate a SEND needs to be restarted from an |
| * earlier PSN without interfering with the sending thread. |
| * See restart_rc(). |
| */ |
| qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu); |
| /* FALLTHROUGH */ |
| case OP(SEND_FIRST): |
| qp->s_state = OP(SEND_MIDDLE); |
| /* FALLTHROUGH */ |
| case OP(SEND_MIDDLE): |
| bth2 = mask_psn(qp->s_psn++); |
| ss = &qp->s_sge; |
| len = qp->s_len; |
| if (len > pmtu) { |
| len = pmtu; |
| middle = HFI1_CAP_IS_KSET(SDMA_AHG); |
| break; |
| } |
| if (wqe->wr.opcode == IB_WR_SEND) { |
| qp->s_state = OP(SEND_LAST); |
| } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) { |
| qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE); |
| /* Immediate data comes after the BTH */ |
| ohdr->u.imm_data = wqe->wr.ex.imm_data; |
| hwords += 1; |
| } else { |
| qp->s_state = OP(SEND_LAST_WITH_INVALIDATE); |
| /* invalidate data comes after the BTH */ |
| ohdr->u.ieth = cpu_to_be32(wqe->wr.ex.invalidate_rkey); |
| hwords += 1; |
| } |
| if (wqe->wr.send_flags & IB_SEND_SOLICITED) |
| bth0 |= IB_BTH_SOLICITED; |
| bth2 |= IB_BTH_REQ_ACK; |
| qp->s_cur++; |
| if (qp->s_cur >= qp->s_size) |
| qp->s_cur = 0; |
| break; |
| |
| case OP(RDMA_READ_RESPONSE_LAST): |
| /* |
| * qp->s_state is normally set to the opcode of the |
| * last packet constructed for new requests and therefore |
| * is never set to RDMA read response. |
| * RDMA_READ_RESPONSE_LAST is used by the ACK processing |
| * thread to indicate a RDMA write needs to be restarted from |
| * an earlier PSN without interfering with the sending thread. |
| * See restart_rc(). |
| */ |
| qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu); |
| /* FALLTHROUGH */ |
| case OP(RDMA_WRITE_FIRST): |
| qp->s_state = OP(RDMA_WRITE_MIDDLE); |
| /* FALLTHROUGH */ |
| case OP(RDMA_WRITE_MIDDLE): |
| bth2 = mask_psn(qp->s_psn++); |
| ss = &qp->s_sge; |
| len = qp->s_len; |
| if (len > pmtu) { |
| len = pmtu; |
| middle = HFI1_CAP_IS_KSET(SDMA_AHG); |
| break; |
| } |
| if (wqe->wr.opcode == IB_WR_RDMA_WRITE) { |
| qp->s_state = OP(RDMA_WRITE_LAST); |
| } else { |
| qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE); |
| /* Immediate data comes after the BTH */ |
| ohdr->u.imm_data = wqe->wr.ex.imm_data; |
| hwords += 1; |
| if (wqe->wr.send_flags & IB_SEND_SOLICITED) |
| bth0 |= IB_BTH_SOLICITED; |
| } |
| bth2 |= IB_BTH_REQ_ACK; |
| qp->s_cur++; |
| if (qp->s_cur >= qp->s_size) |
| qp->s_cur = 0; |
| break; |
| |
| case OP(RDMA_READ_RESPONSE_MIDDLE): |
| /* |
| * qp->s_state is normally set to the opcode of the |
| * last packet constructed for new requests and therefore |
| * is never set to RDMA read response. |
| * RDMA_READ_RESPONSE_MIDDLE is used by the ACK processing |
| * thread to indicate a RDMA read needs to be restarted from |
| * an earlier PSN without interfering with the sending thread. |
| * See restart_rc(). |
| */ |
| len = (delta_psn(qp->s_psn, wqe->psn)) * pmtu; |
| put_ib_reth_vaddr( |
| wqe->rdma_wr.remote_addr + len, |
| &ohdr->u.rc.reth); |
| ohdr->u.rc.reth.rkey = |
| cpu_to_be32(wqe->rdma_wr.rkey); |
| ohdr->u.rc.reth.length = cpu_to_be32(wqe->length - len); |
| qp->s_state = OP(RDMA_READ_REQUEST); |
| hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32); |
| bth2 = mask_psn(qp->s_psn) | IB_BTH_REQ_ACK; |
| qp->s_psn = wqe->lpsn + 1; |
| ss = NULL; |
| len = 0; |
| qp->s_cur++; |
| if (qp->s_cur == qp->s_size) |
| qp->s_cur = 0; |
| break; |
| } |
| qp->s_sending_hpsn = bth2; |
| delta = delta_psn(bth2, wqe->psn); |
| if (delta && delta % HFI1_PSN_CREDIT == 0) |
| bth2 |= IB_BTH_REQ_ACK; |
| if (qp->s_flags & RVT_S_SEND_ONE) { |
| qp->s_flags &= ~RVT_S_SEND_ONE; |
| qp->s_flags |= RVT_S_WAIT_ACK; |
| bth2 |= IB_BTH_REQ_ACK; |
| } |
| qp->s_len -= len; |
| qp->s_hdrwords = hwords; |
| ps->s_txreq->sde = priv->s_sde; |
| ps->s_txreq->ss = ss; |
| ps->s_txreq->s_cur_size = len; |
| hfi1_make_ruc_header( |
| qp, |
| ohdr, |
| bth0 | (qp->s_state << 24), |
| bth2, |
| middle, |
| ps); |
| /* pbc */ |
| ps->s_txreq->hdr_dwords = qp->s_hdrwords + 2; |
| return 1; |
| |
| done_free_tx: |
| hfi1_put_txreq(ps->s_txreq); |
| ps->s_txreq = NULL; |
| return 1; |
| |
| bail: |
| hfi1_put_txreq(ps->s_txreq); |
| |
| bail_no_tx: |
| ps->s_txreq = NULL; |
| qp->s_flags &= ~RVT_S_BUSY; |
| qp->s_hdrwords = 0; |
| return 0; |
| } |
| |
| /** |
| * hfi1_send_rc_ack - Construct an ACK packet and send it |
| * @qp: a pointer to the QP |
| * |
| * This is called from hfi1_rc_rcv() and handle_receive_interrupt(). |
| * Note that RDMA reads and atomics are handled in the |
| * send side QP state and send engine. |
| */ |
| void hfi1_send_rc_ack(struct hfi1_ctxtdata *rcd, struct rvt_qp *qp, |
| int is_fecn) |
| { |
| struct hfi1_ibport *ibp = rcd_to_iport(rcd); |
| struct hfi1_pportdata *ppd = ppd_from_ibp(ibp); |
| u64 pbc, pbc_flags = 0; |
| u16 lrh0; |
| u16 sc5; |
| u32 bth0; |
| u32 hwords; |
| u32 vl, plen; |
| struct send_context *sc; |
| struct pio_buf *pbuf; |
| struct ib_header hdr; |
| struct ib_other_headers *ohdr; |
| unsigned long flags; |
| struct hfi1_qp_priv *priv = qp->priv; |
| |
| /* clear the defer count */ |
| priv->r_adefered = 0; |
| |
| /* Don't send ACK or NAK if a RDMA read or atomic is pending. */ |
| if (qp->s_flags & RVT_S_RESP_PENDING) |
| goto queue_ack; |
| |
| /* Ensure s_rdma_ack_cnt changes are committed */ |
| smp_read_barrier_depends(); |
| if (qp->s_rdma_ack_cnt) |
| goto queue_ack; |
| |
| /* Construct the header */ |
| /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4 */ |
| hwords = 6; |
| if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) { |
| hwords += hfi1_make_grh(ibp, &hdr.u.l.grh, |
| &qp->remote_ah_attr.grh, hwords, 0); |
| ohdr = &hdr.u.l.oth; |
| lrh0 = HFI1_LRH_GRH; |
| } else { |
| ohdr = &hdr.u.oth; |
| lrh0 = HFI1_LRH_BTH; |
| } |
| /* read pkey_index w/o lock (its atomic) */ |
| bth0 = hfi1_get_pkey(ibp, qp->s_pkey_index) | (OP(ACKNOWLEDGE) << 24); |
| if (qp->s_mig_state == IB_MIG_MIGRATED) |
| bth0 |= IB_BTH_MIG_REQ; |
| if (qp->r_nak_state) |
| ohdr->u.aeth = cpu_to_be32((qp->r_msn & RVT_MSN_MASK) | |
| (qp->r_nak_state << |
| RVT_AETH_CREDIT_SHIFT)); |
| else |
| ohdr->u.aeth = rvt_compute_aeth(qp); |
| sc5 = ibp->sl_to_sc[qp->remote_ah_attr.sl]; |
| /* set PBC_DC_INFO bit (aka SC[4]) in pbc_flags */ |
| pbc_flags |= ((!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT); |
| lrh0 |= (sc5 & 0xf) << 12 | (qp->remote_ah_attr.sl & 0xf) << 4; |
| hdr.lrh[0] = cpu_to_be16(lrh0); |
| hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid); |
| hdr.lrh[2] = cpu_to_be16(hwords + SIZE_OF_CRC); |
| hdr.lrh[3] = cpu_to_be16(ppd->lid | qp->remote_ah_attr.src_path_bits); |
| ohdr->bth[0] = cpu_to_be32(bth0); |
| ohdr->bth[1] = cpu_to_be32(qp->remote_qpn); |
| ohdr->bth[1] |= cpu_to_be32((!!is_fecn) << HFI1_BECN_SHIFT); |
| ohdr->bth[2] = cpu_to_be32(mask_psn(qp->r_ack_psn)); |
| |
| /* Don't try to send ACKs if the link isn't ACTIVE */ |
| if (driver_lstate(ppd) != IB_PORT_ACTIVE) |
| return; |
| |
| sc = rcd->sc; |
| plen = 2 /* PBC */ + hwords; |
| vl = sc_to_vlt(ppd->dd, sc5); |
| pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps, vl, plen); |
| |
| pbuf = sc_buffer_alloc(sc, plen, NULL, NULL); |
| if (!pbuf) { |
| /* |
| * We have no room to send at the moment. Pass |
| * responsibility for sending the ACK to the send engine |
| * so that when enough buffer space becomes available, |
| * the ACK is sent ahead of other outgoing packets. |
| */ |
| goto queue_ack; |
| } |
| |
| trace_ack_output_ibhdr(dd_from_ibdev(qp->ibqp.device), &hdr); |
| |
| /* write the pbc and data */ |
| ppd->dd->pio_inline_send(ppd->dd, pbuf, pbc, &hdr, hwords); |
| |
| return; |
| |
| queue_ack: |
| spin_lock_irqsave(&qp->s_lock, flags); |
| if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) |
| goto unlock; |
| this_cpu_inc(*ibp->rvp.rc_qacks); |
| qp->s_flags |= RVT_S_ACK_PENDING | RVT_S_RESP_PENDING; |
| qp->s_nak_state = qp->r_nak_state; |
| qp->s_ack_psn = qp->r_ack_psn; |
| if (is_fecn) |
| qp->s_flags |= RVT_S_ECN; |
| |
| /* Schedule the send engine. */ |
| hfi1_schedule_send(qp); |
| unlock: |
| spin_unlock_irqrestore(&qp->s_lock, flags); |
| } |
| |
| /** |
| * reset_psn - reset the QP state to send starting from PSN |
| * @qp: the QP |
| * @psn: the packet sequence number to restart at |
| * |
| * This is called from hfi1_rc_rcv() to process an incoming RC ACK |
| * for the given QP. |
| * Called at interrupt level with the QP s_lock held. |
| */ |
| static void reset_psn(struct rvt_qp *qp, u32 psn) |
| { |
| u32 n = qp->s_acked; |
| struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, n); |
| u32 opcode; |
| |
| lockdep_assert_held(&qp->s_lock); |
| qp->s_cur = n; |
| |
| /* |
| * If we are starting the request from the beginning, |
| * let the normal send code handle initialization. |
| */ |
| if (cmp_psn(psn, wqe->psn) <= 0) { |
| qp->s_state = OP(SEND_LAST); |
| goto done; |
| } |
| |
| /* Find the work request opcode corresponding to the given PSN. */ |
| opcode = wqe->wr.opcode; |
| for (;;) { |
| int diff; |
| |
| if (++n == qp->s_size) |
| n = 0; |
| if (n == qp->s_tail) |
| break; |
| wqe = rvt_get_swqe_ptr(qp, n); |
| diff = cmp_psn(psn, wqe->psn); |
| if (diff < 0) |
| break; |
| qp->s_cur = n; |
| /* |
| * If we are starting the request from the beginning, |
| * let the normal send code handle initialization. |
| */ |
| if (diff == 0) { |
| qp->s_state = OP(SEND_LAST); |
| goto done; |
| } |
| opcode = wqe->wr.opcode; |
| } |
| |
| /* |
| * Set the state to restart in the middle of a request. |
| * Don't change the s_sge, s_cur_sge, or s_cur_size. |
| * See hfi1_make_rc_req(). |
| */ |
| switch (opcode) { |
| case IB_WR_SEND: |
| case IB_WR_SEND_WITH_IMM: |
| qp->s_state = OP(RDMA_READ_RESPONSE_FIRST); |
| break; |
| |
| case IB_WR_RDMA_WRITE: |
| case IB_WR_RDMA_WRITE_WITH_IMM: |
| qp->s_state = OP(RDMA_READ_RESPONSE_LAST); |
| break; |
| |
| case IB_WR_RDMA_READ: |
| qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE); |
| break; |
| |
| default: |
| /* |
| * This case shouldn't happen since its only |
| * one PSN per req. |
| */ |
| qp->s_state = OP(SEND_LAST); |
| } |
| done: |
| qp->s_psn = psn; |
| /* |
| * Set RVT_S_WAIT_PSN as rc_complete() may start the timer |
| * asynchronously before the send engine can get scheduled. |
| * Doing it in hfi1_make_rc_req() is too late. |
| */ |
| if ((cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) && |
| (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)) |
| qp->s_flags |= RVT_S_WAIT_PSN; |
| qp->s_flags &= ~RVT_S_AHG_VALID; |
| } |
| |
| /* |
| * Back up requester to resend the last un-ACKed request. |
| * The QP r_lock and s_lock should be held and interrupts disabled. |
| */ |
| void hfi1_restart_rc(struct rvt_qp *qp, u32 psn, int wait) |
| { |
| struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, qp->s_acked); |
| struct hfi1_ibport *ibp; |
| |
| lockdep_assert_held(&qp->r_lock); |
| lockdep_assert_held(&qp->s_lock); |
| if (qp->s_retry == 0) { |
| if (qp->s_mig_state == IB_MIG_ARMED) { |
| hfi1_migrate_qp(qp); |
| qp->s_retry = qp->s_retry_cnt; |
| } else if (qp->s_last == qp->s_acked) { |
| hfi1_send_complete(qp, wqe, IB_WC_RETRY_EXC_ERR); |
| rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR); |
| return; |
| } else { /* need to handle delayed completion */ |
| return; |
| } |
| } else { |
| qp->s_retry--; |
| } |
| |
| ibp = to_iport(qp->ibqp.device, qp->port_num); |
| if (wqe->wr.opcode == IB_WR_RDMA_READ) |
| ibp->rvp.n_rc_resends++; |
| else |
| ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn); |
| |
| qp->s_flags &= ~(RVT_S_WAIT_FENCE | RVT_S_WAIT_RDMAR | |
| RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_PSN | |
| RVT_S_WAIT_ACK); |
| if (wait) |
| qp->s_flags |= RVT_S_SEND_ONE; |
| reset_psn(qp, psn); |
| } |
| |
| /* |
| * Set qp->s_sending_psn to the next PSN after the given one. |
| * This would be psn+1 except when RDMA reads are present. |
| */ |
| static void reset_sending_psn(struct rvt_qp *qp, u32 psn) |
| { |
| struct rvt_swqe *wqe; |
| u32 n = qp->s_last; |
| |
| lockdep_assert_held(&qp->s_lock); |
| /* Find the work request corresponding to the given PSN. */ |
| for (;;) { |
| wqe = rvt_get_swqe_ptr(qp, n); |
| if (cmp_psn(psn, wqe->lpsn) <= 0) { |
| if (wqe->wr.opcode == IB_WR_RDMA_READ) |
| qp->s_sending_psn = wqe->lpsn + 1; |
| else |
| qp->s_sending_psn = psn + 1; |
| break; |
| } |
| if (++n == qp->s_size) |
| n = 0; |
| if (n == qp->s_tail) |
| break; |
| } |
| } |
| |
| /* |
| * This should be called with the QP s_lock held and interrupts disabled. |
| */ |
| void hfi1_rc_send_complete(struct rvt_qp *qp, struct ib_header *hdr) |
| { |
| struct ib_other_headers *ohdr; |
| struct rvt_swqe *wqe; |
| u32 opcode; |
| u32 psn; |
| |
| lockdep_assert_held(&qp->s_lock); |
| if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_OR_FLUSH_SEND)) |
| return; |
| |
| /* Find out where the BTH is */ |
| if ((be16_to_cpu(hdr->lrh[0]) & 3) == HFI1_LRH_BTH) |
| ohdr = &hdr->u.oth; |
| else |
| ohdr = &hdr->u.l.oth; |
| |
| opcode = be32_to_cpu(ohdr->bth[0]) >> 24; |
| if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) && |
| opcode <= OP(ATOMIC_ACKNOWLEDGE)) { |
| WARN_ON(!qp->s_rdma_ack_cnt); |
| qp->s_rdma_ack_cnt--; |
| return; |
| } |
| |
| psn = be32_to_cpu(ohdr->bth[2]); |
| reset_sending_psn(qp, psn); |
| |
| /* |
| * Start timer after a packet requesting an ACK has been sent and |
| * there are still requests that haven't been acked. |
| */ |
| if ((psn & IB_BTH_REQ_ACK) && qp->s_acked != qp->s_tail && |
| !(qp->s_flags & |
| (RVT_S_TIMER | RVT_S_WAIT_RNR | RVT_S_WAIT_PSN)) && |
| (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) |
| rvt_add_retry_timer(qp); |
| |
| while (qp->s_last != qp->s_acked) { |
| u32 s_last; |
| |
| wqe = rvt_get_swqe_ptr(qp, qp->s_last); |
| if (cmp_psn(wqe->lpsn, qp->s_sending_psn) >= 0 && |
| cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) |
| break; |
| s_last = qp->s_last; |
| if (++s_last >= qp->s_size) |
| s_last = 0; |
| qp->s_last = s_last; |
| /* see post_send() */ |
| barrier(); |
| rvt_put_swqe(wqe); |
| rvt_qp_swqe_complete(qp, wqe, IB_WC_SUCCESS); |
| } |
| /* |
| * If we were waiting for sends to complete before re-sending, |
| * and they are now complete, restart sending. |
| */ |
| trace_hfi1_sendcomplete(qp, psn); |
| if (qp->s_flags & RVT_S_WAIT_PSN && |
| cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) { |
| qp->s_flags &= ~RVT_S_WAIT_PSN; |
| qp->s_sending_psn = qp->s_psn; |
| qp->s_sending_hpsn = qp->s_psn - 1; |
| hfi1_schedule_send(qp); |
| } |
| } |
| |
| static inline void update_last_psn(struct rvt_qp *qp, u32 psn) |
| { |
| qp->s_last_psn = psn; |
| } |
| |
| /* |
| * Generate a SWQE completion. |
| * This is similar to hfi1_send_complete but has to check to be sure |
| * that the SGEs are not being referenced if the SWQE is being resent. |
| */ |
| static struct rvt_swqe *do_rc_completion(struct rvt_qp *qp, |
| struct rvt_swqe *wqe, |
| struct hfi1_ibport *ibp) |
| { |
| lockdep_assert_held(&qp->s_lock); |
| /* |
| * Don't decrement refcount and don't generate a |
| * completion if the SWQE is being resent until the send |
| * is finished. |
| */ |
| if (cmp_psn(wqe->lpsn, qp->s_sending_psn) < 0 || |
| cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) { |
| u32 s_last; |
| |
| rvt_put_swqe(wqe); |
| s_last = qp->s_last; |
| if (++s_last >= qp->s_size) |
| s_last = 0; |
| qp->s_last = s_last; |
| /* see post_send() */ |
| barrier(); |
| rvt_qp_swqe_complete(qp, wqe, IB_WC_SUCCESS); |
| } else { |
| struct hfi1_pportdata *ppd = ppd_from_ibp(ibp); |
| |
| this_cpu_inc(*ibp->rvp.rc_delayed_comp); |
| /* |
| * If send progress not running attempt to progress |
| * SDMA queue. |
| */ |
| if (ppd->dd->flags & HFI1_HAS_SEND_DMA) { |
| struct sdma_engine *engine; |
| u8 sc5; |
| |
| /* For now use sc to find engine */ |
| sc5 = ibp->sl_to_sc[qp->remote_ah_attr.sl]; |
| engine = qp_to_sdma_engine(qp, sc5); |
| sdma_engine_progress_schedule(engine); |
| } |
| } |
| |
| qp->s_retry = qp->s_retry_cnt; |
| update_last_psn(qp, wqe->lpsn); |
| |
| /* |
| * If we are completing a request which is in the process of |
| * being resent, we can stop re-sending it since we know the |
| * responder has already seen it. |
| */ |
| if (qp->s_acked == qp->s_cur) { |
| if (++qp->s_cur >= qp->s_size) |
| qp->s_cur = 0; |
| qp->s_acked = qp->s_cur; |
| wqe = rvt_get_swqe_ptr(qp, qp->s_cur); |
| if (qp->s_acked != qp->s_tail) { |
| qp->s_state = OP(SEND_LAST); |
| qp->s_psn = wqe->psn; |
| } |
| } else { |
| if (++qp->s_acked >= qp->s_size) |
| qp->s_acked = 0; |
| if (qp->state == IB_QPS_SQD && qp->s_acked == qp->s_cur) |
| qp->s_draining = 0; |
| wqe = rvt_get_swqe_ptr(qp, qp->s_acked); |
| } |
| return wqe; |
| } |
| |
| /** |
| * do_rc_ack - process an incoming RC ACK |
| * @qp: the QP the ACK came in on |
| * @psn: the packet sequence number of the ACK |
| * @opcode: the opcode of the request that resulted in the ACK |
| * |
| * This is called from rc_rcv_resp() to process an incoming RC ACK |
| * for the given QP. |
| * May be called at interrupt level, with the QP s_lock held. |
| * Returns 1 if OK, 0 if current operation should be aborted (NAK). |
| */ |
| static int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode, |
| u64 val, struct hfi1_ctxtdata *rcd) |
| { |
| struct hfi1_ibport *ibp; |
| enum ib_wc_status status; |
| struct rvt_swqe *wqe; |
| int ret = 0; |
| u32 ack_psn; |
| int diff; |
| |
| lockdep_assert_held(&qp->s_lock); |
| /* |
| * Note that NAKs implicitly ACK outstanding SEND and RDMA write |
| * requests and implicitly NAK RDMA read and atomic requests issued |
| * before the NAK'ed request. The MSN won't include the NAK'ed |
| * request but will include an ACK'ed request(s). |
| */ |
| ack_psn = psn; |
| if (aeth >> RVT_AETH_NAK_SHIFT) |
| ack_psn--; |
| wqe = rvt_get_swqe_ptr(qp, qp->s_acked); |
| ibp = rcd_to_iport(rcd); |
| |
| /* |
| * The MSN might be for a later WQE than the PSN indicates so |
| * only complete WQEs that the PSN finishes. |
| */ |
| while ((diff = delta_psn(ack_psn, wqe->lpsn)) >= 0) { |
| /* |
| * RDMA_READ_RESPONSE_ONLY is a special case since |
| * we want to generate completion events for everything |
| * before the RDMA read, copy the data, then generate |
| * the completion for the read. |
| */ |
| if (wqe->wr.opcode == IB_WR_RDMA_READ && |
| opcode == OP(RDMA_READ_RESPONSE_ONLY) && |
| diff == 0) { |
| ret = 1; |
| goto bail_stop; |
| } |
| /* |
| * If this request is a RDMA read or atomic, and the ACK is |
| * for a later operation, this ACK NAKs the RDMA read or |
| * atomic. In other words, only a RDMA_READ_LAST or ONLY |
| * can ACK a RDMA read and likewise for atomic ops. Note |
| * that the NAK case can only happen if relaxed ordering is |
| * used and requests are sent after an RDMA read or atomic |
| * is sent but before the response is received. |
| */ |
| if ((wqe->wr.opcode == IB_WR_RDMA_READ && |
| (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) || |
| ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP || |
| wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) && |
| (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0))) { |
| /* Retry this request. */ |
| if (!(qp->r_flags & RVT_R_RDMAR_SEQ)) { |
| qp->r_flags |= RVT_R_RDMAR_SEQ; |
| hfi1_restart_rc(qp, qp->s_last_psn + 1, 0); |
| if (list_empty(&qp->rspwait)) { |
| qp->r_flags |= RVT_R_RSP_SEND; |
| rvt_get_qp(qp); |
| list_add_tail(&qp->rspwait, |
| &rcd->qp_wait_list); |
| } |
| } |
| /* |
| * No need to process the ACK/NAK since we are |
| * restarting an earlier request. |
| */ |
| goto bail_stop; |
| } |
| if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP || |
| wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) { |
| u64 *vaddr = wqe->sg_list[0].vaddr; |
| *vaddr = val; |
| } |
| if (qp->s_num_rd_atomic && |
| (wqe->wr.opcode == IB_WR_RDMA_READ || |
| wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP || |
| wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) { |
| qp->s_num_rd_atomic--; |
| /* Restart sending task if fence is complete */ |
| if ((qp->s_flags & RVT_S_WAIT_FENCE) && |
| !qp->s_num_rd_atomic) { |
| qp->s_flags &= ~(RVT_S_WAIT_FENCE | |
| RVT_S_WAIT_ACK); |
| hfi1_schedule_send(qp); |
| } else if (qp->s_flags & RVT_S_WAIT_RDMAR) { |
| qp->s_flags &= ~(RVT_S_WAIT_RDMAR | |
| RVT_S_WAIT_ACK); |
| hfi1_schedule_send(qp); |
| } |
| } |
| wqe = do_rc_completion(qp, wqe, ibp); |
| if (qp->s_acked == qp->s_tail) |
| break; |
| } |
| |
| switch (aeth >> RVT_AETH_NAK_SHIFT) { |
| case 0: /* ACK */ |
| this_cpu_inc(*ibp->rvp.rc_acks); |
| if (qp->s_acked != qp->s_tail) { |
| /* |
| * We are expecting more ACKs so |
| * mod the retry timer. |
| */ |
| rvt_mod_retry_timer(qp); |
| /* |
| * We can stop re-sending the earlier packets and |
| * continue with the next packet the receiver wants. |
| */ |
| if (cmp_psn(qp->s_psn, psn) <= 0) |
| reset_psn(qp, psn + 1); |
| } else { |
| /* No more acks - kill all timers */ |
| rvt_stop_rc_timers(qp); |
| if (cmp_psn(qp->s_psn, psn) <= 0) { |
| qp->s_state = OP(SEND_LAST); |
| qp->s_psn = psn + 1; |
| } |
| } |
| if (qp->s_flags & RVT_S_WAIT_ACK) { |
| qp->s_flags &= ~RVT_S_WAIT_ACK; |
| hfi1_schedule_send(qp); |
| } |
| rvt_get_credit(qp, aeth); |
| qp->s_rnr_retry = qp->s_rnr_retry_cnt; |
| qp->s_retry = qp->s_retry_cnt; |
| update_last_psn(qp, psn); |
| return 1; |
| |
| case 1: /* RNR NAK */ |
| ibp->rvp.n_rnr_naks++; |
| if (qp->s_acked == qp->s_tail) |
| goto bail_stop; |
| if (qp->s_flags & RVT_S_WAIT_RNR) |
| goto bail_stop; |
| if (qp->s_rnr_retry == 0) { |
| status = IB_WC_RNR_RETRY_EXC_ERR; |
| goto class_b; |
| } |
| if (qp->s_rnr_retry_cnt < 7) |
| qp->s_rnr_retry--; |
| |
| /* The last valid PSN is the previous PSN. */ |
| update_last_psn(qp, psn - 1); |
| |
| ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn); |
| |
| reset_psn(qp, psn); |
| |
| qp->s_flags &= ~(RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_ACK); |
| rvt_stop_rc_timers(qp); |
| rvt_add_rnr_timer(qp, aeth); |
| return 0; |
| |
| case 3: /* NAK */ |
| if (qp->s_acked == qp->s_tail) |
| goto bail_stop; |
| /* The last valid PSN is the previous PSN. */ |
| update_last_psn(qp, psn - 1); |
| switch ((aeth >> RVT_AETH_CREDIT_SHIFT) & |
| RVT_AETH_CREDIT_MASK) { |
| case 0: /* PSN sequence error */ |
| ibp->rvp.n_seq_naks++; |
| /* |
| * Back up to the responder's expected PSN. |
| * Note that we might get a NAK in the middle of an |
| * RDMA READ response which terminates the RDMA |
| * READ. |
| */ |
| hfi1_restart_rc(qp, psn, 0); |
| hfi1_schedule_send(qp); |
| break; |
| |
| case 1: /* Invalid Request */ |
| status = IB_WC_REM_INV_REQ_ERR; |
| ibp->rvp.n_other_naks++; |
| goto class_b; |
| |
| case 2: /* Remote Access Error */ |
| status = IB_WC_REM_ACCESS_ERR; |
| ibp->rvp.n_other_naks++; |
| goto class_b; |
| |
| case 3: /* Remote Operation Error */ |
| status = IB_WC_REM_OP_ERR; |
| ibp->rvp.n_other_naks++; |
| class_b: |
| if (qp->s_last == qp->s_acked) { |
| hfi1_send_complete(qp, wqe, status); |
| rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR); |
| } |
| break; |
| |
| default: |
| /* Ignore other reserved NAK error codes */ |
| goto reserved; |
| } |
| qp->s_retry = qp->s_retry_cnt; |
| qp->s_rnr_retry = qp->s_rnr_retry_cnt; |
| goto bail_stop; |
| |
| default: /* 2: reserved */ |
| reserved: |
| /* Ignore reserved NAK codes. */ |
| goto bail_stop; |
| } |
| /* cannot be reached */ |
| bail_stop: |
| rvt_stop_rc_timers(qp); |
| return ret; |
| } |
| |
| /* |
| * We have seen an out of sequence RDMA read middle or last packet. |
| * This ACKs SENDs and RDMA writes up to the first RDMA read or atomic SWQE. |
| */ |
| static void rdma_seq_err(struct rvt_qp *qp, struct hfi1_ibport *ibp, u32 psn, |
| struct hfi1_ctxtdata *rcd) |
| { |
| struct rvt_swqe *wqe; |
| |
| lockdep_assert_held(&qp->s_lock); |
| /* Remove QP from retry timer */ |
| rvt_stop_rc_timers(qp); |
| |
| wqe = rvt_get_swqe_ptr(qp, qp->s_acked); |
| |
| while (cmp_psn(psn, wqe->lpsn) > 0) { |
| if (wqe->wr.opcode == IB_WR_RDMA_READ || |
| wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP || |
| wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) |
| break; |
| wqe = do_rc_completion(qp, wqe, ibp); |
| } |
| |
| ibp->rvp.n_rdma_seq++; |
| qp->r_flags |= RVT_R_RDMAR_SEQ; |
| hfi1_restart_rc(qp, qp->s_last_psn + 1, 0); |
| if (list_empty(&qp->rspwait)) { |
| qp->r_flags |= RVT_R_RSP_SEND; |
| rvt_get_qp(qp); |
| list_add_tail(&qp->rspwait, &rcd->qp_wait_list); |
| } |
| } |
| |
| /** |
| * rc_rcv_resp - process an incoming RC response packet |
| * @ibp: the port this packet came in on |
| * @ohdr: the other headers for this packet |
| * @data: the packet data |
| * @tlen: the packet length |
| * @qp: the QP for this packet |
| * @opcode: the opcode for this packet |
| * @psn: the packet sequence number for this packet |
| * @hdrsize: the header length |
| * @pmtu: the path MTU |
| * |
| * This is called from hfi1_rc_rcv() to process an incoming RC response |
| * packet for the given QP. |
| * Called at interrupt level. |
| */ |
| static void rc_rcv_resp(struct hfi1_ibport *ibp, |
| struct ib_other_headers *ohdr, |
| void *data, u32 tlen, struct rvt_qp *qp, |
| u32 opcode, u32 psn, u32 hdrsize, u32 pmtu, |
| struct hfi1_ctxtdata *rcd) |
| { |
| struct rvt_swqe *wqe; |
| enum ib_wc_status status; |
| unsigned long flags; |
| int diff; |
| u32 pad; |
| u32 aeth; |
| u64 val; |
| |
| spin_lock_irqsave(&qp->s_lock, flags); |
| |
| trace_hfi1_ack(qp, psn); |
| |
| /* Ignore invalid responses. */ |
| smp_read_barrier_depends(); /* see post_one_send */ |
| if (cmp_psn(psn, READ_ONCE(qp->s_next_psn)) >= 0) |
| goto ack_done; |
| |
| /* Ignore duplicate responses. */ |
| diff = cmp_psn(psn, qp->s_last_psn); |
| if (unlikely(diff <= 0)) { |
| /* Update credits for "ghost" ACKs */ |
| if (diff == 0 && opcode == OP(ACKNOWLEDGE)) { |
| aeth = be32_to_cpu(ohdr->u.aeth); |
| if ((aeth >> RVT_AETH_NAK_SHIFT) == 0) |
| rvt_get_credit(qp, aeth); |
| } |
| goto ack_done; |
| } |
| |
| /* |
| * Skip everything other than the PSN we expect, if we are waiting |
| * for a reply to a restarted RDMA read or atomic op. |
| */ |
| if (qp->r_flags & RVT_R_RDMAR_SEQ) { |
| if (cmp_psn(psn, qp->s_last_psn + 1) != 0) |
| goto ack_done; |
| qp->r_flags &= ~RVT_R_RDMAR_SEQ; |
| } |
| |
| if (unlikely(qp->s_acked == qp->s_tail)) |
| goto ack_done; |
| wqe = rvt_get_swqe_ptr(qp, qp->s_acked); |
| status = IB_WC_SUCCESS; |
| |
| switch (opcode) { |
| case OP(ACKNOWLEDGE): |
| case OP(ATOMIC_ACKNOWLEDGE): |
| case OP(RDMA_READ_RESPONSE_FIRST): |
| aeth = be32_to_cpu(ohdr->u.aeth); |
| if (opcode == OP(ATOMIC_ACKNOWLEDGE)) |
| val = ib_u64_get(&ohdr->u.at.atomic_ack_eth); |
| else |
| val = 0; |
| if (!do_rc_ack(qp, aeth, psn, opcode, val, rcd) || |
| opcode != OP(RDMA_READ_RESPONSE_FIRST)) |
| goto ack_done; |
| wqe = rvt_get_swqe_ptr(qp, qp->s_acked); |
| if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ)) |
| goto ack_op_err; |
| /* |
| * If this is a response to a resent RDMA read, we |
| * have to be careful to copy the data to the right |
| * location. |
| */ |
| qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge, |
| wqe, psn, pmtu); |
| goto read_middle; |
| |
| case OP(RDMA_READ_RESPONSE_MIDDLE): |
| /* no AETH, no ACK */ |
| if (unlikely(cmp_psn(psn, qp->s_last_psn + 1))) |
| goto ack_seq_err; |
| if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ)) |
| goto ack_op_err; |
| read_middle: |
| if (unlikely(tlen != (hdrsize + pmtu + 4))) |
| goto ack_len_err; |
| if (unlikely(pmtu >= qp->s_rdma_read_len)) |
| goto ack_len_err; |
| |
| /* |
| * We got a response so update the timeout. |
| * 4.096 usec. * (1 << qp->timeout) |
| */ |
| rvt_mod_retry_timer(qp); |
| if (qp->s_flags & RVT_S_WAIT_ACK) { |
| qp->s_flags &= ~RVT_S_WAIT_ACK; |
| hfi1_schedule_send(qp); |
| } |
| |
| if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE)) |
| qp->s_retry = qp->s_retry_cnt; |
| |
| /* |
| * Update the RDMA receive state but do the copy w/o |
| * holding the locks and blocking interrupts. |
| */ |
| qp->s_rdma_read_len -= pmtu; |
| update_last_psn(qp, psn); |
| spin_unlock_irqrestore(&qp->s_lock, flags); |
| hfi1_copy_sge(&qp->s_rdma_read_sge, data, pmtu, false, false); |
| goto bail; |
| |
| case OP(RDMA_READ_RESPONSE_ONLY): |
| aeth = be32_to_cpu(ohdr->u.aeth); |
| if (!do_rc_ack(qp, aeth, psn, opcode, 0, rcd)) |
| goto ack_done; |
| /* Get the number of bytes the message was padded by. */ |
| pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3; |
| /* |
| * Check that the data size is >= 0 && <= pmtu. |
| * Remember to account for ICRC (4). |
| */ |
| if (unlikely(tlen < (hdrsize + pad + 4))) |
| goto ack_len_err; |
| /* |
| * If this is a response to a resent RDMA read, we |
| * have to be careful to copy the data to the right |
| * location. |
| */ |
| wqe = rvt_get_swqe_ptr(qp, qp->s_acked); |
| qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge, |
| wqe, psn, pmtu); |
| goto read_last; |
| |
| case OP(RDMA_READ_RESPONSE_LAST): |
| /* ACKs READ req. */ |
| if (unlikely(cmp_psn(psn, qp->s_last_psn + 1))) |
| goto ack_seq_err; |
| if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ)) |
| goto ack_op_err; |
| /* Get the number of bytes the message was padded by. */ |
| pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3; |
| /* |
| * Check that the data size is >= 1 && <= pmtu. |
| * Remember to account for ICRC (4). |
| */ |
| if (unlikely(tlen <= (hdrsize + pad + 4))) |
| goto ack_len_err; |
| read_last: |
| tlen -= hdrsize + pad + 4; |
| if (unlikely(tlen != qp->s_rdma_read_len)) |
| goto ack_len_err; |
| aeth = be32_to_cpu(ohdr->u.aeth); |
| hfi1_copy_sge(&qp->s_rdma_read_sge, data, tlen, false, false); |
| WARN_ON(qp->s_rdma_read_sge.num_sge); |
| (void)do_rc_ack(qp, aeth, psn, |
| OP(RDMA_READ_RESPONSE_LAST), 0, rcd); |
| goto ack_done; |
| } |
| |
| ack_op_err: |
| status = IB_WC_LOC_QP_OP_ERR; |
| goto ack_err; |
| |
| ack_seq_err: |
| rdma_seq_err(qp, ibp, psn, rcd); |
| goto ack_done; |
| |
| ack_len_err: |
| status = IB_WC_LOC_LEN_ERR; |
| ack_err: |
| if (qp->s_last == qp->s_acked) { |
| hfi1_send_complete(qp, wqe, status); |
| rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR); |
| } |
| ack_done: |
| spin_unlock_irqrestore(&qp->s_lock, flags); |
| bail: |
| return; |
| } |
| |
| static inline void rc_defered_ack(struct hfi1_ctxtdata *rcd, |
| struct rvt_qp *qp) |
| { |
| if (list_empty(&qp->rspwait)) { |
| qp->r_flags |= RVT_R_RSP_NAK; |
| rvt_get_qp(qp); |
| list_add_tail(&qp->rspwait, &rcd->qp_wait_list); |
| } |
| } |
| |
| static inline void rc_cancel_ack(struct rvt_qp *qp) |
| { |
| struct hfi1_qp_priv *priv = qp->priv; |
| |
| priv->r_adefered = 0; |
| if (list_empty(&qp->rspwait)) |
| return; |
| list_del_init(&qp->rspwait); |
| qp->r_flags &= ~RVT_R_RSP_NAK; |
| rvt_put_qp(qp); |
| } |
| |
| /** |
| * rc_rcv_error - process an incoming duplicate or error RC packet |
| * @ohdr: the other headers for this packet |
| * @data: the packet data |
| * @qp: the QP for this packet |
| * @opcode: the opcode for this packet |
| * @psn: the packet sequence number for this packet |
| * @diff: the difference between the PSN and the expected PSN |
| * |
| * This is called from hfi1_rc_rcv() to process an unexpected |
| * incoming RC packet for the given QP. |
| * Called at interrupt level. |
| * Return 1 if no more processing is needed; otherwise return 0 to |
| * schedule a response to be sent. |
| */ |
| static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data, |
| struct rvt_qp *qp, u32 opcode, u32 psn, |
| int diff, struct hfi1_ctxtdata *rcd) |
| { |
| struct hfi1_ibport *ibp = rcd_to_iport(rcd); |
| struct rvt_ack_entry *e; |
| unsigned long flags; |
| u8 i, prev; |
| int old_req; |
| |
| trace_hfi1_rcv_error(qp, psn); |
| if (diff > 0) { |
| /* |
| * Packet sequence error. |
| * A NAK will ACK earlier sends and RDMA writes. |
| * Don't queue the NAK if we already sent one. |
| */ |
| if (!qp->r_nak_state) { |
| ibp->rvp.n_rc_seqnak++; |
| qp->r_nak_state = IB_NAK_PSN_ERROR; |
| /* Use the expected PSN. */ |
| qp->r_ack_psn = qp->r_psn; |
| /* |
| * Wait to send the sequence NAK until all packets |
| * in the receive queue have been processed. |
| * Otherwise, we end up propagating congestion. |
| */ |
| rc_defered_ack(rcd, qp); |
| } |
| goto done; |
| } |
| |
| /* |
| * Handle a duplicate request. Don't re-execute SEND, RDMA |
| * write or atomic op. Don't NAK errors, just silently drop |
| * the duplicate request. Note that r_sge, r_len, and |
| * r_rcv_len may be in use so don't modify them. |
| * |
| * We are supposed to ACK the earliest duplicate PSN but we |
| * can coalesce an outstanding duplicate ACK. We have to |
| * send the earliest so that RDMA reads can be restarted at |
| * the requester's expected PSN. |
| * |
| * First, find where this duplicate PSN falls within the |
| * ACKs previously sent. |
| * old_req is true if there is an older response that is scheduled |
| * to be sent before sending this one. |
| */ |
| e = NULL; |
| old_req = 1; |
| ibp->rvp.n_rc_dupreq++; |
| |
| spin_lock_irqsave(&qp->s_lock, flags); |
| |
| for (i = qp->r_head_ack_queue; ; i = prev) { |
| if (i == qp->s_tail_ack_queue) |
| old_req = 0; |
| if (i) |
| prev = i - 1; |
| else |
| prev = HFI1_MAX_RDMA_ATOMIC; |
| if (prev == qp->r_head_ack_queue) { |
| e = NULL; |
| break; |
| } |
| e = &qp->s_ack_queue[prev]; |
| if (!e->opcode) { |
| e = NULL; |
| break; |
| } |
| if (cmp_psn(psn, e->psn) >= 0) { |
| if (prev == qp->s_tail_ack_queue && |
| cmp_psn(psn, e->lpsn) <= 0) |
| old_req = 0; |
| break; |
| } |
| } |
| switch (opcode) { |
| case OP(RDMA_READ_REQUEST): { |
| struct ib_reth *reth; |
| u32 offset; |
| u32 len; |
| |
| /* |
| * If we didn't find the RDMA read request in the ack queue, |
| * we can ignore this request. |
| */ |
| if (!e || e->opcode != OP(RDMA_READ_REQUEST)) |
| goto unlock_done; |
| /* RETH comes after BTH */ |
| reth = &ohdr->u.rc.reth; |
| /* |
| * Address range must be a subset of the original |
| * request and start on pmtu boundaries. |
| * We reuse the old ack_queue slot since the requester |
| * should not back up and request an earlier PSN for the |
| * same request. |
| */ |
| offset = delta_psn(psn, e->psn) * qp->pmtu; |
| len = be32_to_cpu(reth->length); |
| if (unlikely(offset + len != e->rdma_sge.sge_length)) |
| goto unlock_done; |
| if (e->rdma_sge.mr) { |
| rvt_put_mr(e->rdma_sge.mr); |
| e->rdma_sge.mr = NULL; |
| } |
| if (len != 0) { |
| u32 rkey = be32_to_cpu(reth->rkey); |
| u64 vaddr = get_ib_reth_vaddr(reth); |
| int ok; |
| |
| ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey, |
| IB_ACCESS_REMOTE_READ); |
| if (unlikely(!ok)) |
| goto unlock_done; |
| } else { |
| e->rdma_sge.vaddr = NULL; |
| e->rdma_sge.length = 0; |
| e->rdma_sge.sge_length = 0; |
| } |
| e->psn = psn; |
| if (old_req) |
| goto unlock_done; |
| qp->s_tail_ack_queue = prev; |
| break; |
| } |
| |
| case OP(COMPARE_SWAP): |
| case OP(FETCH_ADD): { |
| /* |
| * If we didn't find the atomic request in the ack queue |
| * or the send engine is already backed up to send an |
| * earlier entry, we can ignore this request. |
| */ |
| if (!e || e->opcode != (u8)opcode || old_req) |
| goto unlock_done; |
| qp->s_tail_ack_queue = prev; |
| break; |
| } |
| |
| default: |
| /* |
| * Ignore this operation if it doesn't request an ACK |
| * or an earlier RDMA read or atomic is going to be resent. |
| */ |
| if (!(psn & IB_BTH_REQ_ACK) || old_req) |
| goto unlock_done; |
| /* |
| * Resend the most recent ACK if this request is |
| * after all the previous RDMA reads and atomics. |
| */ |
| if (i == qp->r_head_ack_queue) { |
| spin_unlock_irqrestore(&qp->s_lock, flags); |
| qp->r_nak_state = 0; |
| qp->r_ack_psn = qp->r_psn - 1; |
| goto send_ack; |
| } |
| |
| /* |
| * Resend the RDMA read or atomic op which |
| * ACKs this duplicate request. |
| */ |
| qp->s_tail_ack_queue = i; |
| break; |
| } |
| qp->s_ack_state = OP(ACKNOWLEDGE); |
| qp->s_flags |= RVT_S_RESP_PENDING; |
| qp->r_nak_state = 0; |
| hfi1_schedule_send(qp); |
| |
| unlock_done: |
| spin_unlock_irqrestore(&qp->s_lock, flags); |
| done: |
| return 1; |
| |
| send_ack: |
| return 0; |
| } |
| |
| static inline void update_ack_queue(struct rvt_qp *qp, unsigned n) |
| { |
| unsigned next; |
| |
| next = n + 1; |
| if (next > HFI1_MAX_RDMA_ATOMIC) |
| next = 0; |
| qp->s_tail_ack_queue = next; |
| qp->s_ack_state = OP(ACKNOWLEDGE); |
| } |
| |
| static void log_cca_event(struct hfi1_pportdata *ppd, u8 sl, u32 rlid, |
| u32 lqpn, u32 rqpn, u8 svc_type) |
| { |
| struct opa_hfi1_cong_log_event_internal *cc_event; |
| unsigned long flags; |
| |
| if (sl >= OPA_MAX_SLS) |
| return; |
| |
| spin_lock_irqsave(&ppd->cc_log_lock, flags); |
| |
| ppd->threshold_cong_event_map[sl / 8] |= 1 << (sl % 8); |
| ppd->threshold_event_counter++; |
| |
| cc_event = &ppd->cc_events[ppd->cc_log_idx++]; |
| if (ppd->cc_log_idx == OPA_CONG_LOG_ELEMS) |
| ppd->cc_log_idx = 0; |
| cc_event->lqpn = lqpn & RVT_QPN_MASK; |
| cc_event->rqpn = rqpn & RVT_QPN_MASK; |
| cc_event->sl = sl; |
| cc_event->svc_type = svc_type; |
| cc_event->rlid = rlid; |
| /* keep timestamp in units of 1.024 usec */ |
| cc_event->timestamp = ktime_to_ns(ktime_get()) / 1024; |
| |
| spin_unlock_irqrestore(&ppd->cc_log_lock, flags); |
| } |
| |
| void process_becn(struct hfi1_pportdata *ppd, u8 sl, u16 rlid, u32 lqpn, |
| u32 rqpn, u8 svc_type) |
| { |
| struct cca_timer *cca_timer; |
| u16 ccti, ccti_incr, ccti_timer, ccti_limit; |
| u8 trigger_threshold; |
| struct cc_state *cc_state; |
| unsigned long flags; |
| |
| if (sl >= OPA_MAX_SLS) |
| return; |
| |
| cc_state = get_cc_state(ppd); |
| |
| if (!cc_state) |
| return; |
| |
| /* |
| * 1) increase CCTI (for this SL) |
| * 2) select IPG (i.e., call set_link_ipg()) |
| * 3) start timer |
| */ |
| ccti_limit = cc_state->cct.ccti_limit; |
| ccti_incr = cc_state->cong_setting.entries[sl].ccti_increase; |
| ccti_timer = cc_state->cong_setting.entries[sl].ccti_timer; |
| trigger_threshold = |
| cc_state->cong_setting.entries[sl].trigger_threshold; |
| |
| spin_lock_irqsave(&ppd->cca_timer_lock, flags); |
| |
| cca_timer = &ppd->cca_timer[sl]; |
| if (cca_timer->ccti < ccti_limit) { |
| if (cca_timer->ccti + ccti_incr <= ccti_limit) |
| cca_timer->ccti += ccti_incr; |
| else |
| cca_timer->ccti = ccti_limit; |
| set_link_ipg(ppd); |
| } |
| |
| ccti = cca_timer->ccti; |
| |
| if (!hrtimer_active(&cca_timer->hrtimer)) { |
| /* ccti_timer is in units of 1.024 usec */ |
| unsigned long nsec = 1024 * ccti_timer; |
| |
| hrtimer_start(&cca_timer->hrtimer, ns_to_ktime(nsec), |
| HRTIMER_MODE_REL); |
| } |
| |
| spin_unlock_irqrestore(&ppd->cca_timer_lock, flags); |
| |
| if ((trigger_threshold != 0) && (ccti >= trigger_threshold)) |
| log_cca_event(ppd, sl, rlid, lqpn, rqpn, svc_type); |
| } |
| |
| /** |
| * hfi1_rc_rcv - process an incoming RC packet |
| * @rcd: the context pointer |
| * @hdr: the header of this packet |
| * @rcv_flags: flags relevant to rcv processing |
| * @data: the packet data |
| * @tlen: the packet length |
| * @qp: the QP for this packet |
| * |
| * This is called from qp_rcv() to process an incoming RC packet |
| * for the given QP. |
| * May be called at interrupt level. |
| */ |
| void hfi1_rc_rcv(struct hfi1_packet *packet) |
| { |
| struct hfi1_ctxtdata *rcd = packet->rcd; |
| struct ib_header *hdr = packet->hdr; |
| u32 rcv_flags = packet->rcv_flags; |
| void *data = packet->ebuf; |
| u32 tlen = packet->tlen; |
| struct rvt_qp *qp = packet->qp; |
| struct hfi1_ibport *ibp = rcd_to_iport(rcd); |
| struct ib_other_headers *ohdr = packet->ohdr; |
| u32 bth0, opcode; |
| u32 hdrsize = packet->hlen; |
| u32 psn; |
| u32 pad; |
| struct ib_wc wc; |
| u32 pmtu = qp->pmtu; |
| int diff; |
| struct ib_reth *reth; |
| unsigned long flags; |
| int ret, is_fecn = 0; |
| bool copy_last = false; |
| u32 rkey; |
| |
| lockdep_assert_held(&qp->r_lock); |
| bth0 = be32_to_cpu(ohdr->bth[0]); |
| if (hfi1_ruc_check_hdr(ibp, hdr, rcv_flags & HFI1_HAS_GRH, qp, bth0)) |
| return; |
| |
| is_fecn = process_ecn(qp, packet, false); |
| |
| psn = be32_to_cpu(ohdr->bth[2]); |
| opcode = (bth0 >> 24) & 0xff; |
| |
| /* |
| * Process responses (ACKs) before anything else. Note that the |
| * packet sequence number will be for something in the send work |
| * queue rather than the expected receive packet sequence number. |
| * In other words, this QP is the requester. |
| */ |
| if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) && |
| opcode <= OP(ATOMIC_ACKNOWLEDGE)) { |
| rc_rcv_resp(ibp, ohdr, data, tlen, qp, opcode, psn, |
| hdrsize, pmtu, rcd); |
| if (is_fecn) |
| goto send_ack; |
| return; |
| } |
| |
| /* Compute 24 bits worth of difference. */ |
| diff = delta_psn(psn, qp->r_psn); |
| if (unlikely(diff)) { |
| if (rc_rcv_error(ohdr, data, qp, opcode, psn, diff, rcd)) |
| return; |
| goto send_ack; |
| } |
| |
| /* Check for opcode sequence errors. */ |
| switch (qp->r_state) { |
| case OP(SEND_FIRST): |
| case OP(SEND_MIDDLE): |
| if (opcode == OP(SEND_MIDDLE) || |
| opcode == OP(SEND_LAST) || |
| opcode == OP(SEND_LAST_WITH_IMMEDIATE) || |
| opcode == OP(SEND_LAST_WITH_INVALIDATE)) |
| break; |
| goto nack_inv; |
| |
| case OP(RDMA_WRITE_FIRST): |
| case OP(RDMA_WRITE_MIDDLE): |
| if (opcode == OP(RDMA_WRITE_MIDDLE) || |
| opcode == OP(RDMA_WRITE_LAST) || |
| opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE)) |
| break; |
| goto nack_inv; |
| |
| default: |
| if (opcode == OP(SEND_MIDDLE) || |
| opcode == OP(SEND_LAST) || |
| opcode == OP(SEND_LAST_WITH_IMMEDIATE) || |
| opcode == OP(SEND_LAST_WITH_INVALIDATE) || |
| opcode == OP(RDMA_WRITE_MIDDLE) || |
| opcode == OP(RDMA_WRITE_LAST) || |
| opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE)) |
| goto nack_inv; |
| /* |
| * Note that it is up to the requester to not send a new |
| * RDMA read or atomic operation before receiving an ACK |
| * for the previous operation. |
| */ |
| break; |
| } |
| |
| if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST)) |
| rvt_comm_est(qp); |
| |
| /* OK, process the packet. */ |
| switch (opcode) { |
| case OP(SEND_FIRST): |
| ret = hfi1_rvt_get_rwqe(qp, 0); |
| if (ret < 0) |
| goto nack_op_err; |
| if (!ret) |
| goto rnr_nak; |
| qp->r_rcv_len = 0; |
| /* FALLTHROUGH */ |
| case OP(SEND_MIDDLE): |
| case OP(RDMA_WRITE_MIDDLE): |
| send_middle: |
| /* Check for invalid length PMTU or posted rwqe len. */ |
| if (unlikely(tlen != (hdrsize + pmtu + 4))) |
| goto nack_inv; |
| qp->r_rcv_len += pmtu; |
| if (unlikely(qp->r_rcv_len > qp->r_len)) |
| goto nack_inv; |
| hfi1_copy_sge(&qp->r_sge, data, pmtu, true, false); |
| break; |
| |
| case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE): |
| /* consume RWQE */ |
| ret = hfi1_rvt_get_rwqe(qp, 1); |
| if (ret < 0) |
| goto nack_op_err; |
| if (!ret) |
| goto rnr_nak; |
| goto send_last_imm; |
| |
| case OP(SEND_ONLY): |
| case OP(SEND_ONLY_WITH_IMMEDIATE): |
| case OP(SEND_ONLY_WITH_INVALIDATE): |
| ret = hfi1_rvt_get_rwqe(qp, 0); |
| if (ret < 0) |
| goto nack_op_err; |
| if (!ret) |
| goto rnr_nak; |
| qp->r_rcv_len = 0; |
| if (opcode == OP(SEND_ONLY)) |
| goto no_immediate_data; |
| if (opcode == OP(SEND_ONLY_WITH_INVALIDATE)) |
| goto send_last_inv; |
| /* FALLTHROUGH for SEND_ONLY_WITH_IMMEDIATE */ |
| case OP(SEND_LAST_WITH_IMMEDIATE): |
| send_last_imm: |
| wc.ex.imm_data = ohdr->u.imm_data; |
| wc.wc_flags = IB_WC_WITH_IMM; |
| goto send_last; |
| case OP(SEND_LAST_WITH_INVALIDATE): |
| send_last_inv: |
| rkey = be32_to_cpu(ohdr->u.ieth); |
| if (rvt_invalidate_rkey(qp, rkey)) |
| goto no_immediate_data; |
| wc.ex.invalidate_rkey = rkey; |
| wc.wc_flags = IB_WC_WITH_INVALIDATE; |
| goto send_last; |
| case OP(RDMA_WRITE_LAST): |
| copy_last = rvt_is_user_qp(qp); |
| /* fall through */ |
| case OP(SEND_LAST): |
| no_immediate_data: |
| wc.wc_flags = 0; |
| wc.ex.imm_data = 0; |
| send_last: |
| /* Get the number of bytes the message was padded by. */ |
| pad = (bth0 >> 20) & 3; |
| /* Check for invalid length. */ |
| /* LAST len should be >= 1 */ |
| if (unlikely(tlen < (hdrsize + pad + 4))) |
| goto nack_inv; |
| /* Don't count the CRC. */ |
| tlen -= (hdrsize + pad + 4); |
| wc.byte_len = tlen + qp->r_rcv_len; |
| if (unlikely(wc.byte_len > qp->r_len)) |
| goto nack_inv; |
| hfi1_copy_sge(&qp->r_sge, data, tlen, true, copy_last); |
| rvt_put_ss(&qp->r_sge); |
| qp->r_msn++; |
| if (!__test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags)) |
| break; |
| wc.wr_id = qp->r_wr_id; |
| wc.status = IB_WC_SUCCESS; |
| if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) || |
| opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE)) |
| wc.opcode = IB_WC_RECV_RDMA_WITH_IMM; |
| else |
| wc.opcode = IB_WC_RECV; |
| wc.qp = &qp->ibqp; |
| wc.src_qp = qp->remote_qpn; |
| wc.slid = qp->remote_ah_attr.dlid; |
| /* |
| * It seems that IB mandates the presence of an SL in a |
| * work completion only for the UD transport (see section |
| * 11.4.2 of IBTA Vol. 1). |
| * |
| * However, the way the SL is chosen below is consistent |
| * with the way that IB/qib works and is trying avoid |
| * introducing incompatibilities. |
| * |
| * See also OPA Vol. 1, section 9.7.6, and table 9-17. |
| */ |
| wc.sl = qp->remote_ah_attr.sl; |
| /* zero fields that are N/A */ |
| wc.vendor_err = 0; |
| wc.pkey_index = 0; |
| wc.dlid_path_bits = 0; |
| wc.port_num = 0; |
| /* Signal completion event if the solicited bit is set. */ |
| rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc, |
| (bth0 & IB_BTH_SOLICITED) != 0); |
| break; |
| |
| case OP(RDMA_WRITE_ONLY): |
| copy_last = rvt_is_user_qp(qp); |
| /* fall through */ |
| case OP(RDMA_WRITE_FIRST): |
| case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE): |
| if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE))) |
| goto nack_inv; |
| /* consume RWQE */ |
| reth = &ohdr->u.rc.reth; |
| qp->r_len = be32_to_cpu(reth->length); |
| qp->r_rcv_len = 0; |
| qp->r_sge.sg_list = NULL; |
| if (qp->r_len != 0) { |
| u32 rkey = be32_to_cpu(reth->rkey); |
| u64 vaddr = get_ib_reth_vaddr(reth); |
| int ok; |
| |
| /* Check rkey & NAK */ |
| ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len, vaddr, |
| rkey, IB_ACCESS_REMOTE_WRITE); |
| if (unlikely(!ok)) |
| goto nack_acc; |
| qp->r_sge.num_sge = 1; |
| } else { |
| qp->r_sge.num_sge = 0; |
| qp->r_sge.sge.mr = NULL; |
| qp->r_sge.sge.vaddr = NULL; |
| qp->r_sge.sge.length = 0; |
| qp->r_sge.sge.sge_length = 0; |
| } |
| if (opcode == OP(RDMA_WRITE_FIRST)) |
| goto send_middle; |
| else if (opcode == OP(RDMA_WRITE_ONLY)) |
| goto no_immediate_data; |
| ret = hfi1_rvt_get_rwqe(qp, 1); |
| if (ret < 0) |
| goto nack_op_err; |
| if (!ret) |
| goto rnr_nak; |
| wc.ex.imm_data = ohdr->u.rc.imm_data; |
| wc.wc_flags = IB_WC_WITH_IMM; |
| goto send_last; |
| |
| case OP(RDMA_READ_REQUEST): { |
| struct rvt_ack_entry *e; |
| u32 len; |
| u8 next; |
| |
| if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ))) |
| goto nack_inv; |
| next = qp->r_head_ack_queue + 1; |
| /* s_ack_queue is size HFI1_MAX_RDMA_ATOMIC+1 so use > not >= */ |
| if (next > HFI1_MAX_RDMA_ATOMIC) |
| next = 0; |
| spin_lock_irqsave(&qp->s_lock, flags); |
| if (unlikely(next == qp->s_tail_ack_queue)) { |
| if (!qp->s_ack_queue[next].sent) |
| goto nack_inv_unlck; |
| update_ack_queue(qp, next); |
| } |
| e = &qp->s_ack_queue[qp->r_head_ack_queue]; |
| if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) { |
| rvt_put_mr(e->rdma_sge.mr); |
| e->rdma_sge.mr = NULL; |
| } |
| reth = &ohdr->u.rc.reth; |
| len = be32_to_cpu(reth->length); |
| if (len) { |
| u32 rkey = be32_to_cpu(reth->rkey); |
| u64 vaddr = get_ib_reth_vaddr(reth); |
| int ok; |
| |
| /* Check rkey & NAK */ |
| ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr, |
| rkey, IB_ACCESS_REMOTE_READ); |
| if (unlikely(!ok)) |
| goto nack_acc_unlck; |
| /* |
| * Update the next expected PSN. We add 1 later |
| * below, so only add the remainder here. |
| */ |
| qp->r_psn += rvt_div_mtu(qp, len - 1); |
| } else { |
| e->rdma_sge.mr = NULL; |
| e->rdma_sge.vaddr = NULL; |
| e->rdma_sge.length = 0; |
| e->rdma_sge.sge_length = 0; |
| } |
| e->opcode = opcode; |
| e->sent = 0; |
| e->psn = psn; |
| e->lpsn = qp->r_psn; |
| /* |
| * We need to increment the MSN here instead of when we |
| * finish sending the result since a duplicate request would |
| * increment it more than once. |
| */ |
| qp->r_msn++; |
| qp->r_psn++; |
| qp->r_state = opcode; |
| qp->r_nak_state = 0; |
| qp->r_head_ack_queue = next; |
| |
| /* Schedule the send engine. */ |
| qp->s_flags |= RVT_S_RESP_PENDING; |
| hfi1_schedule_send(qp); |
| |
| spin_unlock_irqrestore(&qp->s_lock, flags); |
| if (is_fecn) |
| goto send_ack; |
| return; |
| } |
| |
| case OP(COMPARE_SWAP): |
| case OP(FETCH_ADD): { |
| struct ib_atomic_eth *ateth; |
| struct rvt_ack_entry *e; |
| u64 vaddr; |
| atomic64_t *maddr; |
| u64 sdata; |
| u32 rkey; |
| u8 next; |
| |
| if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC))) |
| goto nack_inv; |
| next = qp->r_head_ack_queue + 1; |
| if (next > HFI1_MAX_RDMA_ATOMIC) |
| next = 0; |
| spin_lock_irqsave(&qp->s_lock, flags); |
| if (unlikely(next == qp->s_tail_ack_queue)) { |
| if (!qp->s_ack_queue[next].sent) |
| goto nack_inv_unlck; |
| update_ack_queue(qp, next); |
| } |
| e = &qp->s_ack_queue[qp->r_head_ack_queue]; |
| if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) { |
| rvt_put_mr(e->rdma_sge.mr); |
| e->rdma_sge.mr = NULL; |
| } |
| ateth = &ohdr->u.atomic_eth; |
| vaddr = get_ib_ateth_vaddr(ateth); |
| if (unlikely(vaddr & (sizeof(u64) - 1))) |
| goto nack_inv_unlck; |
| rkey = be32_to_cpu(ateth->rkey); |
| /* Check rkey & NAK */ |
| if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64), |
| vaddr, rkey, |
| IB_ACCESS_REMOTE_ATOMIC))) |
| goto nack_acc_unlck; |
| /* Perform atomic OP and save result. */ |
| maddr = (atomic64_t *)qp->r_sge.sge.vaddr; |
| sdata = get_ib_ateth_swap(ateth); |
| e->atomic_data = (opcode == OP(FETCH_ADD)) ? |
| (u64)atomic64_add_return(sdata, maddr) - sdata : |
| (u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr, |
| get_ib_ateth_compare(ateth), |
| sdata); |
| rvt_put_mr(qp->r_sge.sge.mr); |
| qp->r_sge.num_sge = 0; |
| e->opcode = opcode; |
| e->sent = 0; |
| e->psn = psn; |
| e->lpsn = psn; |
| qp->r_msn++; |
| qp->r_psn++; |
| qp->r_state = opcode; |
| qp->r_nak_state = 0; |
| qp->r_head_ack_queue = next; |
| |
| /* Schedule the send engine. */ |
| qp->s_flags |= RVT_S_RESP_PENDING; |
| hfi1_schedule_send(qp); |
| |
| spin_unlock_irqrestore(&qp->s_lock, flags); |
| if (is_fecn) |
| goto send_ack; |
| return; |
| } |
| |
| default: |
| /* NAK unknown opcodes. */ |
| goto nack_inv; |
| } |
| qp->r_psn++; |
| qp->r_state = opcode; |
| qp->r_ack_psn = psn; |
| qp->r_nak_state = 0; |
| /* Send an ACK if requested or required. */ |
| if (psn & IB_BTH_REQ_ACK) { |
| struct hfi1_qp_priv *priv = qp->priv; |
| |
| if (packet->numpkt == 0) { |
| rc_cancel_ack(qp); |
| goto send_ack; |
| } |
| if (priv->r_adefered >= HFI1_PSN_CREDIT) { |
| rc_cancel_ack(qp); |
| goto send_ack; |
| } |
| if (unlikely(is_fecn)) { |
| rc_cancel_ack(qp); |
| goto send_ack; |
| } |
| priv->r_adefered++; |
| rc_defered_ack(rcd, qp); |
| } |
| return; |
| |
| rnr_nak: |
| qp->r_nak_state = qp->r_min_rnr_timer | IB_RNR_NAK; |
| qp->r_ack_psn = qp->r_psn; |
| /* Queue RNR NAK for later */ |
| rc_defered_ack(rcd, qp); |
| return; |
| |
| nack_op_err: |
| rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR); |
| qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR; |
| qp->r_ack_psn = qp->r_psn; |
| /* Queue NAK for later */ |
| rc_defered_ack(rcd, qp); |
| return; |
| |
| nack_inv_unlck: |
| spin_unlock_irqrestore(&qp->s_lock, flags); |
| nack_inv: |
| rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR); |
| qp->r_nak_state = IB_NAK_INVALID_REQUEST; |
| qp->r_ack_psn = qp->r_psn; |
| /* Queue NAK for later */ |
| rc_defered_ack(rcd, qp); |
| return; |
| |
| nack_acc_unlck: |
| spin_unlock_irqrestore(&qp->s_lock, flags); |
| nack_acc: |
| rvt_rc_error(qp, IB_WC_LOC_PROT_ERR); |
| qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR; |
| qp->r_ack_psn = qp->r_psn; |
| send_ack: |
| hfi1_send_rc_ack(rcd, qp, is_fecn); |
| } |
| |
| void hfi1_rc_hdrerr( |
| struct hfi1_ctxtdata *rcd, |
| struct ib_header *hdr, |
| u32 rcv_flags, |
| struct rvt_qp *qp) |
| { |
| int has_grh = rcv_flags & HFI1_HAS_GRH; |
| struct ib_other_headers *ohdr; |
| struct hfi1_ibport *ibp = rcd_to_iport(rcd); |
| int diff; |
| u32 opcode; |
| u32 psn, bth0; |
| |
| /* Check for GRH */ |
| ohdr = &hdr->u.oth; |
| if (has_grh) |
| ohdr = &hdr->u.l.oth; |
| |
| bth0 = be32_to_cpu(ohdr->bth[0]); |
| if (hfi1_ruc_check_hdr(ibp, hdr, has_grh, qp, bth0)) |
| return; |
| |
| psn = be32_to_cpu(ohdr->bth[2]); |
| opcode = (bth0 >> 24) & 0xff; |
| |
| /* Only deal with RDMA Writes for now */ |
| if (opcode < IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) { |
| diff = delta_psn(psn, qp->r_psn); |
| if (!qp->r_nak_state && diff >= 0) { |
| ibp->rvp.n_rc_seqnak++; |
| qp->r_nak_state = IB_NAK_PSN_ERROR; |
| /* Use the expected PSN. */ |
| qp->r_ack_psn = qp->r_psn; |
| /* |
| * Wait to send the sequence |
| * NAK until all packets |
| * in the receive queue have |
| * been processed. |
| * Otherwise, we end up |
| * propagating congestion. |
| */ |
| rc_defered_ack(rcd, qp); |
| } /* Out of sequence NAK */ |
| } /* QP Request NAKs */ |
| } |