Merge tag 'nfs-for-5.14-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
[linux-2.6-microblaze.git] / drivers / infiniband / hw / hfi1 / rc.c
1 /*
2  * Copyright(c) 2015 - 2018 Intel Corporation.
3  *
4  * This file is provided under a dual BSD/GPLv2 license.  When using or
5  * redistributing this file, you may do so under either license.
6  *
7  * GPL LICENSE SUMMARY
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of version 2 of the GNU General Public License as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * BSD LICENSE
19  *
20  * Redistribution and use in source and binary forms, with or without
21  * modification, are permitted provided that the following conditions
22  * are met:
23  *
24  *  - Redistributions of source code must retain the above copyright
25  *    notice, this list of conditions and the following disclaimer.
26  *  - Redistributions in binary form must reproduce the above copyright
27  *    notice, this list of conditions and the following disclaimer in
28  *    the documentation and/or other materials provided with the
29  *    distribution.
30  *  - Neither the name of Intel Corporation nor the names of its
31  *    contributors may be used to endorse or promote products derived
32  *    from this software without specific prior written permission.
33  *
34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
45  *
46  */
47
48 #include <linux/io.h>
49 #include <rdma/rdma_vt.h>
50 #include <rdma/rdmavt_qp.h>
51
52 #include "hfi.h"
53 #include "qp.h"
54 #include "rc.h"
55 #include "verbs_txreq.h"
56 #include "trace.h"
57
58 struct rvt_ack_entry *find_prev_entry(struct rvt_qp *qp, u32 psn, u8 *prev,
59                                       u8 *prev_ack, bool *scheduled)
60         __must_hold(&qp->s_lock)
61 {
62         struct rvt_ack_entry *e = NULL;
63         u8 i, p;
64         bool s = true;
65
66         for (i = qp->r_head_ack_queue; ; i = p) {
67                 if (i == qp->s_tail_ack_queue)
68                         s = false;
69                 if (i)
70                         p = i - 1;
71                 else
72                         p = rvt_size_atomic(ib_to_rvt(qp->ibqp.device));
73                 if (p == qp->r_head_ack_queue) {
74                         e = NULL;
75                         break;
76                 }
77                 e = &qp->s_ack_queue[p];
78                 if (!e->opcode) {
79                         e = NULL;
80                         break;
81                 }
82                 if (cmp_psn(psn, e->psn) >= 0) {
83                         if (p == qp->s_tail_ack_queue &&
84                             cmp_psn(psn, e->lpsn) <= 0)
85                                 s = false;
86                         break;
87                 }
88         }
89         if (prev)
90                 *prev = p;
91         if (prev_ack)
92                 *prev_ack = i;
93         if (scheduled)
94                 *scheduled = s;
95         return e;
96 }
97
98 /**
99  * make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
100  * @dev: the device for this QP
101  * @qp: a pointer to the QP
102  * @ohdr: a pointer to the IB header being constructed
103  * @ps: the xmit packet state
104  *
105  * Return 1 if constructed; otherwise, return 0.
106  * Note that we are in the responder's side of the QP context.
107  * Note the QP s_lock must be held.
108  */
109 static int make_rc_ack(struct hfi1_ibdev *dev, struct rvt_qp *qp,
110                        struct ib_other_headers *ohdr,
111                        struct hfi1_pkt_state *ps)
112 {
113         struct rvt_ack_entry *e;
114         u32 hwords, hdrlen;
115         u32 len = 0;
116         u32 bth0 = 0, bth2 = 0;
117         u32 bth1 = qp->remote_qpn | (HFI1_CAP_IS_KSET(OPFN) << IB_BTHE_E_SHIFT);
118         int middle = 0;
119         u32 pmtu = qp->pmtu;
120         struct hfi1_qp_priv *qpriv = qp->priv;
121         bool last_pkt;
122         u32 delta;
123         u8 next = qp->s_tail_ack_queue;
124         struct tid_rdma_request *req;
125
126         trace_hfi1_rsp_make_rc_ack(qp, 0);
127         lockdep_assert_held(&qp->s_lock);
128         /* Don't send an ACK if we aren't supposed to. */
129         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
130                 goto bail;
131
132         if (qpriv->hdr_type == HFI1_PKT_TYPE_9B)
133                 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
134                 hwords = 5;
135         else
136                 /* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
137                 hwords = 7;
138
139         switch (qp->s_ack_state) {
140         case OP(RDMA_READ_RESPONSE_LAST):
141         case OP(RDMA_READ_RESPONSE_ONLY):
142                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
143                 release_rdma_sge_mr(e);
144                 fallthrough;
145         case OP(ATOMIC_ACKNOWLEDGE):
146                 /*
147                  * We can increment the tail pointer now that the last
148                  * response has been sent instead of only being
149                  * constructed.
150                  */
151                 if (++next > rvt_size_atomic(&dev->rdi))
152                         next = 0;
153                 /*
154                  * Only advance the s_acked_ack_queue pointer if there
155                  * have been no TID RDMA requests.
156                  */
157                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
158                 if (e->opcode != TID_OP(WRITE_REQ) &&
159                     qp->s_acked_ack_queue == qp->s_tail_ack_queue)
160                         qp->s_acked_ack_queue = next;
161                 qp->s_tail_ack_queue = next;
162                 trace_hfi1_rsp_make_rc_ack(qp, e->psn);
163                 fallthrough;
164         case OP(SEND_ONLY):
165         case OP(ACKNOWLEDGE):
166                 /* Check for no next entry in the queue. */
167                 if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
168                         if (qp->s_flags & RVT_S_ACK_PENDING)
169                                 goto normal;
170                         goto bail;
171                 }
172
173                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
174                 /* Check for tid write fence */
175                 if ((qpriv->s_flags & HFI1_R_TID_WAIT_INTERLCK) ||
176                     hfi1_tid_rdma_ack_interlock(qp, e)) {
177                         iowait_set_flag(&qpriv->s_iowait, IOWAIT_PENDING_IB);
178                         goto bail;
179                 }
180                 if (e->opcode == OP(RDMA_READ_REQUEST)) {
181                         /*
182                          * If a RDMA read response is being resent and
183                          * we haven't seen the duplicate request yet,
184                          * then stop sending the remaining responses the
185                          * responder has seen until the requester re-sends it.
186                          */
187                         len = e->rdma_sge.sge_length;
188                         if (len && !e->rdma_sge.mr) {
189                                 if (qp->s_acked_ack_queue ==
190                                     qp->s_tail_ack_queue)
191                                         qp->s_acked_ack_queue =
192                                                 qp->r_head_ack_queue;
193                                 qp->s_tail_ack_queue = qp->r_head_ack_queue;
194                                 goto bail;
195                         }
196                         /* Copy SGE state in case we need to resend */
197                         ps->s_txreq->mr = e->rdma_sge.mr;
198                         if (ps->s_txreq->mr)
199                                 rvt_get_mr(ps->s_txreq->mr);
200                         qp->s_ack_rdma_sge.sge = e->rdma_sge;
201                         qp->s_ack_rdma_sge.num_sge = 1;
202                         ps->s_txreq->ss = &qp->s_ack_rdma_sge;
203                         if (len > pmtu) {
204                                 len = pmtu;
205                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
206                         } else {
207                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
208                                 e->sent = 1;
209                         }
210                         ohdr->u.aeth = rvt_compute_aeth(qp);
211                         hwords++;
212                         qp->s_ack_rdma_psn = e->psn;
213                         bth2 = mask_psn(qp->s_ack_rdma_psn++);
214                 } else if (e->opcode == TID_OP(WRITE_REQ)) {
215                         /*
216                          * If a TID RDMA WRITE RESP is being resent, we have to
217                          * wait for the actual request. All requests that are to
218                          * be resent will have their state set to
219                          * TID_REQUEST_RESEND. When the new request arrives, the
220                          * state will be changed to TID_REQUEST_RESEND_ACTIVE.
221                          */
222                         req = ack_to_tid_req(e);
223                         if (req->state == TID_REQUEST_RESEND ||
224                             req->state == TID_REQUEST_INIT_RESEND)
225                                 goto bail;
226                         qp->s_ack_state = TID_OP(WRITE_RESP);
227                         qp->s_ack_rdma_psn = mask_psn(e->psn + req->cur_seg);
228                         goto write_resp;
229                 } else if (e->opcode == TID_OP(READ_REQ)) {
230                         /*
231                          * If a TID RDMA read response is being resent and
232                          * we haven't seen the duplicate request yet,
233                          * then stop sending the remaining responses the
234                          * responder has seen until the requester re-sends it.
235                          */
236                         len = e->rdma_sge.sge_length;
237                         if (len && !e->rdma_sge.mr) {
238                                 if (qp->s_acked_ack_queue ==
239                                     qp->s_tail_ack_queue)
240                                         qp->s_acked_ack_queue =
241                                                 qp->r_head_ack_queue;
242                                 qp->s_tail_ack_queue = qp->r_head_ack_queue;
243                                 goto bail;
244                         }
245                         /* Copy SGE state in case we need to resend */
246                         ps->s_txreq->mr = e->rdma_sge.mr;
247                         if (ps->s_txreq->mr)
248                                 rvt_get_mr(ps->s_txreq->mr);
249                         qp->s_ack_rdma_sge.sge = e->rdma_sge;
250                         qp->s_ack_rdma_sge.num_sge = 1;
251                         qp->s_ack_state = TID_OP(READ_RESP);
252                         goto read_resp;
253                 } else {
254                         /* COMPARE_SWAP or FETCH_ADD */
255                         ps->s_txreq->ss = NULL;
256                         len = 0;
257                         qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
258                         ohdr->u.at.aeth = rvt_compute_aeth(qp);
259                         ib_u64_put(e->atomic_data, &ohdr->u.at.atomic_ack_eth);
260                         hwords += sizeof(ohdr->u.at) / sizeof(u32);
261                         bth2 = mask_psn(e->psn);
262                         e->sent = 1;
263                 }
264                 trace_hfi1_tid_write_rsp_make_rc_ack(qp);
265                 bth0 = qp->s_ack_state << 24;
266                 break;
267
268         case OP(RDMA_READ_RESPONSE_FIRST):
269                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
270                 fallthrough;
271         case OP(RDMA_READ_RESPONSE_MIDDLE):
272                 ps->s_txreq->ss = &qp->s_ack_rdma_sge;
273                 ps->s_txreq->mr = qp->s_ack_rdma_sge.sge.mr;
274                 if (ps->s_txreq->mr)
275                         rvt_get_mr(ps->s_txreq->mr);
276                 len = qp->s_ack_rdma_sge.sge.sge_length;
277                 if (len > pmtu) {
278                         len = pmtu;
279                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
280                 } else {
281                         ohdr->u.aeth = rvt_compute_aeth(qp);
282                         hwords++;
283                         qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
284                         e = &qp->s_ack_queue[qp->s_tail_ack_queue];
285                         e->sent = 1;
286                 }
287                 bth0 = qp->s_ack_state << 24;
288                 bth2 = mask_psn(qp->s_ack_rdma_psn++);
289                 break;
290
291         case TID_OP(WRITE_RESP):
292 write_resp:
293                 /*
294                  * 1. Check if RVT_S_ACK_PENDING is set. If yes,
295                  *    goto normal.
296                  * 2. Attempt to allocate TID resources.
297                  * 3. Remove RVT_S_RESP_PENDING flags from s_flags
298                  * 4. If resources not available:
299                  *    4.1 Set RVT_S_WAIT_TID_SPACE
300                  *    4.2 Queue QP on RCD TID queue
301                  *    4.3 Put QP on iowait list.
302                  *    4.4 Build IB RNR NAK with appropriate timeout value
303                  *    4.5 Return indication progress made.
304                  * 5. If resources are available:
305                  *    5.1 Program HW flow CSRs
306                  *    5.2 Build TID RDMA WRITE RESP packet
307                  *    5.3 If more resources needed, do 2.1 - 2.3.
308                  *    5.4 Wake up next QP on RCD TID queue.
309                  *    5.5 Return indication progress made.
310                  */
311
312                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
313                 req = ack_to_tid_req(e);
314
315                 /*
316                  * Send scheduled RNR NAK's. RNR NAK's need to be sent at
317                  * segment boundaries, not at request boundaries. Don't change
318                  * s_ack_state because we are still in the middle of a request
319                  */
320                 if (qpriv->rnr_nak_state == TID_RNR_NAK_SEND &&
321                     qp->s_tail_ack_queue == qpriv->r_tid_alloc &&
322                     req->cur_seg == req->alloc_seg) {
323                         qpriv->rnr_nak_state = TID_RNR_NAK_SENT;
324                         goto normal_no_state;
325                 }
326
327                 bth2 = mask_psn(qp->s_ack_rdma_psn);
328                 hdrlen = hfi1_build_tid_rdma_write_resp(qp, e, ohdr, &bth1,
329                                                         bth2, &len,
330                                                         &ps->s_txreq->ss);
331                 if (!hdrlen)
332                         return 0;
333
334                 hwords += hdrlen;
335                 bth0 = qp->s_ack_state << 24;
336                 qp->s_ack_rdma_psn++;
337                 trace_hfi1_tid_req_make_rc_ack_write(qp, 0, e->opcode, e->psn,
338                                                      e->lpsn, req);
339                 if (req->cur_seg != req->total_segs)
340                         break;
341
342                 e->sent = 1;
343                 /* Do not free e->rdma_sge until all data are received */
344                 qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
345                 break;
346
347         case TID_OP(READ_RESP):
348 read_resp:
349                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
350                 ps->s_txreq->ss = &qp->s_ack_rdma_sge;
351                 delta = hfi1_build_tid_rdma_read_resp(qp, e, ohdr, &bth0,
352                                                       &bth1, &bth2, &len,
353                                                       &last_pkt);
354                 if (delta == 0)
355                         goto error_qp;
356                 hwords += delta;
357                 if (last_pkt) {
358                         e->sent = 1;
359                         /*
360                          * Increment qp->s_tail_ack_queue through s_ack_state
361                          * transition.
362                          */
363                         qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
364                 }
365                 break;
366         case TID_OP(READ_REQ):
367                 goto bail;
368
369         default:
370 normal:
371                 /*
372                  * Send a regular ACK.
373                  * Set the s_ack_state so we wait until after sending
374                  * the ACK before setting s_ack_state to ACKNOWLEDGE
375                  * (see above).
376                  */
377                 qp->s_ack_state = OP(SEND_ONLY);
378 normal_no_state:
379                 if (qp->s_nak_state)
380                         ohdr->u.aeth =
381                                 cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
382                                             (qp->s_nak_state <<
383                                              IB_AETH_CREDIT_SHIFT));
384                 else
385                         ohdr->u.aeth = rvt_compute_aeth(qp);
386                 hwords++;
387                 len = 0;
388                 bth0 = OP(ACKNOWLEDGE) << 24;
389                 bth2 = mask_psn(qp->s_ack_psn);
390                 qp->s_flags &= ~RVT_S_ACK_PENDING;
391                 ps->s_txreq->txreq.flags |= SDMA_TXREQ_F_VIP;
392                 ps->s_txreq->ss = NULL;
393         }
394         qp->s_rdma_ack_cnt++;
395         ps->s_txreq->sde = qpriv->s_sde;
396         ps->s_txreq->s_cur_size = len;
397         ps->s_txreq->hdr_dwords = hwords;
398         hfi1_make_ruc_header(qp, ohdr, bth0, bth1, bth2, middle, ps);
399         return 1;
400 error_qp:
401         spin_unlock_irqrestore(&qp->s_lock, ps->flags);
402         spin_lock_irqsave(&qp->r_lock, ps->flags);
403         spin_lock(&qp->s_lock);
404         rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
405         spin_unlock(&qp->s_lock);
406         spin_unlock_irqrestore(&qp->r_lock, ps->flags);
407         spin_lock_irqsave(&qp->s_lock, ps->flags);
408 bail:
409         qp->s_ack_state = OP(ACKNOWLEDGE);
410         /*
411          * Ensure s_rdma_ack_cnt changes are committed prior to resetting
412          * RVT_S_RESP_PENDING
413          */
414         smp_wmb();
415         qp->s_flags &= ~(RVT_S_RESP_PENDING
416                                 | RVT_S_ACK_PENDING
417                                 | HFI1_S_AHG_VALID);
418         return 0;
419 }
420
421 /**
422  * hfi1_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
423  * @qp: a pointer to the QP
424  * @ps: the current packet state
425  *
426  * Assumes s_lock is held.
427  *
428  * Return 1 if constructed; otherwise, return 0.
429  */
430 int hfi1_make_rc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
431 {
432         struct hfi1_qp_priv *priv = qp->priv;
433         struct hfi1_ibdev *dev = to_idev(qp->ibqp.device);
434         struct ib_other_headers *ohdr;
435         struct rvt_sge_state *ss = NULL;
436         struct rvt_swqe *wqe;
437         struct hfi1_swqe_priv *wpriv;
438         struct tid_rdma_request *req = NULL;
439         /* header size in 32-bit words LRH+BTH = (8+12)/4. */
440         u32 hwords = 5;
441         u32 len = 0;
442         u32 bth0 = 0, bth2 = 0;
443         u32 bth1 = qp->remote_qpn | (HFI1_CAP_IS_KSET(OPFN) << IB_BTHE_E_SHIFT);
444         u32 pmtu = qp->pmtu;
445         char newreq;
446         int middle = 0;
447         int delta;
448         struct tid_rdma_flow *flow = NULL;
449         struct tid_rdma_params *remote;
450
451         trace_hfi1_sender_make_rc_req(qp);
452         lockdep_assert_held(&qp->s_lock);
453         ps->s_txreq = get_txreq(ps->dev, qp);
454         if (!ps->s_txreq)
455                 goto bail_no_tx;
456
457         if (priv->hdr_type == HFI1_PKT_TYPE_9B) {
458                 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
459                 hwords = 5;
460                 if (rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)
461                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.l.oth;
462                 else
463                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.oth;
464         } else {
465                 /* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
466                 hwords = 7;
467                 if ((rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
468                     (hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))))
469                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.l.oth;
470                 else
471                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.oth;
472         }
473
474         /* Sending responses has higher priority over sending requests. */
475         if ((qp->s_flags & RVT_S_RESP_PENDING) &&
476             make_rc_ack(dev, qp, ohdr, ps))
477                 return 1;
478
479         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
480                 if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
481                         goto bail;
482                 /* We are in the error state, flush the work request. */
483                 if (qp->s_last == READ_ONCE(qp->s_head))
484                         goto bail;
485                 /* If DMAs are in progress, we can't flush immediately. */
486                 if (iowait_sdma_pending(&priv->s_iowait)) {
487                         qp->s_flags |= RVT_S_WAIT_DMA;
488                         goto bail;
489                 }
490                 clear_ahg(qp);
491                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
492                 hfi1_trdma_send_complete(qp, wqe, qp->s_last != qp->s_acked ?
493                                          IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR);
494                 /* will get called again */
495                 goto done_free_tx;
496         }
497
498         if (qp->s_flags & (RVT_S_WAIT_RNR | RVT_S_WAIT_ACK | HFI1_S_WAIT_HALT))
499                 goto bail;
500
501         if (cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) {
502                 if (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) {
503                         qp->s_flags |= RVT_S_WAIT_PSN;
504                         goto bail;
505                 }
506                 qp->s_sending_psn = qp->s_psn;
507                 qp->s_sending_hpsn = qp->s_psn - 1;
508         }
509
510         /* Send a request. */
511         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
512 check_s_state:
513         switch (qp->s_state) {
514         default:
515                 if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK))
516                         goto bail;
517                 /*
518                  * Resend an old request or start a new one.
519                  *
520                  * We keep track of the current SWQE so that
521                  * we don't reset the "furthest progress" state
522                  * if we need to back up.
523                  */
524                 newreq = 0;
525                 if (qp->s_cur == qp->s_tail) {
526                         /* Check if send work queue is empty. */
527                         if (qp->s_tail == READ_ONCE(qp->s_head)) {
528                                 clear_ahg(qp);
529                                 goto bail;
530                         }
531                         /*
532                          * If a fence is requested, wait for previous
533                          * RDMA read and atomic operations to finish.
534                          * However, there is no need to guard against
535                          * TID RDMA READ after TID RDMA READ.
536                          */
537                         if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
538                             qp->s_num_rd_atomic &&
539                             (wqe->wr.opcode != IB_WR_TID_RDMA_READ ||
540                              priv->pending_tid_r_segs < qp->s_num_rd_atomic)) {
541                                 qp->s_flags |= RVT_S_WAIT_FENCE;
542                                 goto bail;
543                         }
544                         /*
545                          * Local operations are processed immediately
546                          * after all prior requests have completed
547                          */
548                         if (wqe->wr.opcode == IB_WR_REG_MR ||
549                             wqe->wr.opcode == IB_WR_LOCAL_INV) {
550                                 int local_ops = 0;
551                                 int err = 0;
552
553                                 if (qp->s_last != qp->s_cur)
554                                         goto bail;
555                                 if (++qp->s_cur == qp->s_size)
556                                         qp->s_cur = 0;
557                                 if (++qp->s_tail == qp->s_size)
558                                         qp->s_tail = 0;
559                                 if (!(wqe->wr.send_flags &
560                                       RVT_SEND_COMPLETION_ONLY)) {
561                                         err = rvt_invalidate_rkey(
562                                                 qp,
563                                                 wqe->wr.ex.invalidate_rkey);
564                                         local_ops = 1;
565                                 }
566                                 rvt_send_complete(qp, wqe,
567                                                   err ? IB_WC_LOC_PROT_ERR
568                                                       : IB_WC_SUCCESS);
569                                 if (local_ops)
570                                         atomic_dec(&qp->local_ops_pending);
571                                 goto done_free_tx;
572                         }
573
574                         newreq = 1;
575                         qp->s_psn = wqe->psn;
576                 }
577                 /*
578                  * Note that we have to be careful not to modify the
579                  * original work request since we may need to resend
580                  * it.
581                  */
582                 len = wqe->length;
583                 ss = &qp->s_sge;
584                 bth2 = mask_psn(qp->s_psn);
585
586                 /*
587                  * Interlock between various IB requests and TID RDMA
588                  * if necessary.
589                  */
590                 if ((priv->s_flags & HFI1_S_TID_WAIT_INTERLCK) ||
591                     hfi1_tid_rdma_wqe_interlock(qp, wqe))
592                         goto bail;
593
594                 switch (wqe->wr.opcode) {
595                 case IB_WR_SEND:
596                 case IB_WR_SEND_WITH_IMM:
597                 case IB_WR_SEND_WITH_INV:
598                         /* If no credit, return. */
599                         if (!rvt_rc_credit_avail(qp, wqe))
600                                 goto bail;
601                         if (len > pmtu) {
602                                 qp->s_state = OP(SEND_FIRST);
603                                 len = pmtu;
604                                 break;
605                         }
606                         if (wqe->wr.opcode == IB_WR_SEND) {
607                                 qp->s_state = OP(SEND_ONLY);
608                         } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
609                                 qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
610                                 /* Immediate data comes after the BTH */
611                                 ohdr->u.imm_data = wqe->wr.ex.imm_data;
612                                 hwords += 1;
613                         } else {
614                                 qp->s_state = OP(SEND_ONLY_WITH_INVALIDATE);
615                                 /* Invalidate rkey comes after the BTH */
616                                 ohdr->u.ieth = cpu_to_be32(
617                                                 wqe->wr.ex.invalidate_rkey);
618                                 hwords += 1;
619                         }
620                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
621                                 bth0 |= IB_BTH_SOLICITED;
622                         bth2 |= IB_BTH_REQ_ACK;
623                         if (++qp->s_cur == qp->s_size)
624                                 qp->s_cur = 0;
625                         break;
626
627                 case IB_WR_RDMA_WRITE:
628                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
629                                 qp->s_lsn++;
630                         goto no_flow_control;
631                 case IB_WR_RDMA_WRITE_WITH_IMM:
632                         /* If no credit, return. */
633                         if (!rvt_rc_credit_avail(qp, wqe))
634                                 goto bail;
635 no_flow_control:
636                         put_ib_reth_vaddr(
637                                 wqe->rdma_wr.remote_addr,
638                                 &ohdr->u.rc.reth);
639                         ohdr->u.rc.reth.rkey =
640                                 cpu_to_be32(wqe->rdma_wr.rkey);
641                         ohdr->u.rc.reth.length = cpu_to_be32(len);
642                         hwords += sizeof(struct ib_reth) / sizeof(u32);
643                         if (len > pmtu) {
644                                 qp->s_state = OP(RDMA_WRITE_FIRST);
645                                 len = pmtu;
646                                 break;
647                         }
648                         if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
649                                 qp->s_state = OP(RDMA_WRITE_ONLY);
650                         } else {
651                                 qp->s_state =
652                                         OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
653                                 /* Immediate data comes after RETH */
654                                 ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
655                                 hwords += 1;
656                                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
657                                         bth0 |= IB_BTH_SOLICITED;
658                         }
659                         bth2 |= IB_BTH_REQ_ACK;
660                         if (++qp->s_cur == qp->s_size)
661                                 qp->s_cur = 0;
662                         break;
663
664                 case IB_WR_TID_RDMA_WRITE:
665                         if (newreq) {
666                                 /*
667                                  * Limit the number of TID RDMA WRITE requests.
668                                  */
669                                 if (atomic_read(&priv->n_tid_requests) >=
670                                     HFI1_TID_RDMA_WRITE_CNT)
671                                         goto bail;
672
673                                 if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
674                                         qp->s_lsn++;
675                         }
676
677                         hwords += hfi1_build_tid_rdma_write_req(qp, wqe, ohdr,
678                                                                 &bth1, &bth2,
679                                                                 &len);
680                         ss = NULL;
681                         if (priv->s_tid_cur == HFI1_QP_WQE_INVALID) {
682                                 priv->s_tid_cur = qp->s_cur;
683                                 if (priv->s_tid_tail == HFI1_QP_WQE_INVALID) {
684                                         priv->s_tid_tail = qp->s_cur;
685                                         priv->s_state = TID_OP(WRITE_RESP);
686                                 }
687                         } else if (priv->s_tid_cur == priv->s_tid_head) {
688                                 struct rvt_swqe *__w;
689                                 struct tid_rdma_request *__r;
690
691                                 __w = rvt_get_swqe_ptr(qp, priv->s_tid_cur);
692                                 __r = wqe_to_tid_req(__w);
693
694                                 /*
695                                  * The s_tid_cur pointer is advanced to s_cur if
696                                  * any of the following conditions about the WQE
697                                  * to which s_ti_cur currently points to are
698                                  * satisfied:
699                                  *   1. The request is not a TID RDMA WRITE
700                                  *      request,
701                                  *   2. The request is in the INACTIVE or
702                                  *      COMPLETE states (TID RDMA READ requests
703                                  *      stay at INACTIVE and TID RDMA WRITE
704                                  *      transition to COMPLETE when done),
705                                  *   3. The request is in the ACTIVE or SYNC
706                                  *      state and the number of completed
707                                  *      segments is equal to the total segment
708                                  *      count.
709                                  *      (If ACTIVE, the request is waiting for
710                                  *       ACKs. If SYNC, the request has not
711                                  *       received any responses because it's
712                                  *       waiting on a sync point.)
713                                  */
714                                 if (__w->wr.opcode != IB_WR_TID_RDMA_WRITE ||
715                                     __r->state == TID_REQUEST_INACTIVE ||
716                                     __r->state == TID_REQUEST_COMPLETE ||
717                                     ((__r->state == TID_REQUEST_ACTIVE ||
718                                       __r->state == TID_REQUEST_SYNC) &&
719                                      __r->comp_seg == __r->total_segs)) {
720                                         if (priv->s_tid_tail ==
721                                             priv->s_tid_cur &&
722                                             priv->s_state ==
723                                             TID_OP(WRITE_DATA_LAST)) {
724                                                 priv->s_tid_tail = qp->s_cur;
725                                                 priv->s_state =
726                                                         TID_OP(WRITE_RESP);
727                                         }
728                                         priv->s_tid_cur = qp->s_cur;
729                                 }
730                                 /*
731                                  * A corner case: when the last TID RDMA WRITE
732                                  * request was completed, s_tid_head,
733                                  * s_tid_cur, and s_tid_tail all point to the
734                                  * same location. Other requests are posted and
735                                  * s_cur wraps around to the same location,
736                                  * where a new TID RDMA WRITE is posted. In
737                                  * this case, none of the indices need to be
738                                  * updated. However, the priv->s_state should.
739                                  */
740                                 if (priv->s_tid_tail == qp->s_cur &&
741                                     priv->s_state == TID_OP(WRITE_DATA_LAST))
742                                         priv->s_state = TID_OP(WRITE_RESP);
743                         }
744                         req = wqe_to_tid_req(wqe);
745                         if (newreq) {
746                                 priv->s_tid_head = qp->s_cur;
747                                 priv->pending_tid_w_resp += req->total_segs;
748                                 atomic_inc(&priv->n_tid_requests);
749                                 atomic_dec(&priv->n_requests);
750                         } else {
751                                 req->state = TID_REQUEST_RESEND;
752                                 req->comp_seg = delta_psn(bth2, wqe->psn);
753                                 /*
754                                  * Pull back any segments since we are going
755                                  * to re-receive them.
756                                  */
757                                 req->setup_head = req->clear_tail;
758                                 priv->pending_tid_w_resp +=
759                                         delta_psn(wqe->lpsn, bth2) + 1;
760                         }
761
762                         trace_hfi1_tid_write_sender_make_req(qp, newreq);
763                         trace_hfi1_tid_req_make_req_write(qp, newreq,
764                                                           wqe->wr.opcode,
765                                                           wqe->psn, wqe->lpsn,
766                                                           req);
767                         if (++qp->s_cur == qp->s_size)
768                                 qp->s_cur = 0;
769                         break;
770
771                 case IB_WR_RDMA_READ:
772                         /*
773                          * Don't allow more operations to be started
774                          * than the QP limits allow.
775                          */
776                         if (qp->s_num_rd_atomic >=
777                             qp->s_max_rd_atomic) {
778                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
779                                 goto bail;
780                         }
781                         qp->s_num_rd_atomic++;
782                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
783                                 qp->s_lsn++;
784                         put_ib_reth_vaddr(
785                                 wqe->rdma_wr.remote_addr,
786                                 &ohdr->u.rc.reth);
787                         ohdr->u.rc.reth.rkey =
788                                 cpu_to_be32(wqe->rdma_wr.rkey);
789                         ohdr->u.rc.reth.length = cpu_to_be32(len);
790                         qp->s_state = OP(RDMA_READ_REQUEST);
791                         hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
792                         ss = NULL;
793                         len = 0;
794                         bth2 |= IB_BTH_REQ_ACK;
795                         if (++qp->s_cur == qp->s_size)
796                                 qp->s_cur = 0;
797                         break;
798
799                 case IB_WR_TID_RDMA_READ:
800                         trace_hfi1_tid_read_sender_make_req(qp, newreq);
801                         wpriv = wqe->priv;
802                         req = wqe_to_tid_req(wqe);
803                         trace_hfi1_tid_req_make_req_read(qp, newreq,
804                                                          wqe->wr.opcode,
805                                                          wqe->psn, wqe->lpsn,
806                                                          req);
807                         delta = cmp_psn(qp->s_psn, wqe->psn);
808
809                         /*
810                          * Don't allow more operations to be started
811                          * than the QP limits allow. We could get here under
812                          * three conditions; (1) It's a new request; (2) We are
813                          * sending the second or later segment of a request,
814                          * but the qp->s_state is set to OP(RDMA_READ_REQUEST)
815                          * when the last segment of a previous request is
816                          * received just before this; (3) We are re-sending a
817                          * request.
818                          */
819                         if (qp->s_num_rd_atomic >= qp->s_max_rd_atomic) {
820                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
821                                 goto bail;
822                         }
823                         if (newreq) {
824                                 struct tid_rdma_flow *flow =
825                                         &req->flows[req->setup_head];
826
827                                 /*
828                                  * Set up s_sge as it is needed for TID
829                                  * allocation. However, if the pages have been
830                                  * walked and mapped, skip it. An earlier try
831                                  * has failed to allocate the TID entries.
832                                  */
833                                 if (!flow->npagesets) {
834                                         qp->s_sge.sge = wqe->sg_list[0];
835                                         qp->s_sge.sg_list = wqe->sg_list + 1;
836                                         qp->s_sge.num_sge = wqe->wr.num_sge;
837                                         qp->s_sge.total_len = wqe->length;
838                                         qp->s_len = wqe->length;
839                                         req->isge = 0;
840                                         req->clear_tail = req->setup_head;
841                                         req->flow_idx = req->setup_head;
842                                         req->state = TID_REQUEST_ACTIVE;
843                                 }
844                         } else if (delta == 0) {
845                                 /* Re-send a request */
846                                 req->cur_seg = 0;
847                                 req->comp_seg = 0;
848                                 req->ack_pending = 0;
849                                 req->flow_idx = req->clear_tail;
850                                 req->state = TID_REQUEST_RESEND;
851                         }
852                         req->s_next_psn = qp->s_psn;
853                         /* Read one segment at a time */
854                         len = min_t(u32, req->seg_len,
855                                     wqe->length - req->seg_len * req->cur_seg);
856                         delta = hfi1_build_tid_rdma_read_req(qp, wqe, ohdr,
857                                                              &bth1, &bth2,
858                                                              &len);
859                         if (delta <= 0) {
860                                 /* Wait for TID space */
861                                 goto bail;
862                         }
863                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
864                                 qp->s_lsn++;
865                         hwords += delta;
866                         ss = &wpriv->ss;
867                         /* Check if this is the last segment */
868                         if (req->cur_seg >= req->total_segs &&
869                             ++qp->s_cur == qp->s_size)
870                                 qp->s_cur = 0;
871                         break;
872
873                 case IB_WR_ATOMIC_CMP_AND_SWP:
874                 case IB_WR_ATOMIC_FETCH_AND_ADD:
875                         /*
876                          * Don't allow more operations to be started
877                          * than the QP limits allow.
878                          */
879                         if (qp->s_num_rd_atomic >=
880                             qp->s_max_rd_atomic) {
881                                 qp->s_flags |= RVT_S_WAIT_RDMAR;
882                                 goto bail;
883                         }
884                         qp->s_num_rd_atomic++;
885                         fallthrough;
886                 case IB_WR_OPFN:
887                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
888                                 qp->s_lsn++;
889                         if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
890                             wqe->wr.opcode == IB_WR_OPFN) {
891                                 qp->s_state = OP(COMPARE_SWAP);
892                                 put_ib_ateth_swap(wqe->atomic_wr.swap,
893                                                   &ohdr->u.atomic_eth);
894                                 put_ib_ateth_compare(wqe->atomic_wr.compare_add,
895                                                      &ohdr->u.atomic_eth);
896                         } else {
897                                 qp->s_state = OP(FETCH_ADD);
898                                 put_ib_ateth_swap(wqe->atomic_wr.compare_add,
899                                                   &ohdr->u.atomic_eth);
900                                 put_ib_ateth_compare(0, &ohdr->u.atomic_eth);
901                         }
902                         put_ib_ateth_vaddr(wqe->atomic_wr.remote_addr,
903                                            &ohdr->u.atomic_eth);
904                         ohdr->u.atomic_eth.rkey = cpu_to_be32(
905                                 wqe->atomic_wr.rkey);
906                         hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
907                         ss = NULL;
908                         len = 0;
909                         bth2 |= IB_BTH_REQ_ACK;
910                         if (++qp->s_cur == qp->s_size)
911                                 qp->s_cur = 0;
912                         break;
913
914                 default:
915                         goto bail;
916                 }
917                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ) {
918                         qp->s_sge.sge = wqe->sg_list[0];
919                         qp->s_sge.sg_list = wqe->sg_list + 1;
920                         qp->s_sge.num_sge = wqe->wr.num_sge;
921                         qp->s_sge.total_len = wqe->length;
922                         qp->s_len = wqe->length;
923                 }
924                 if (newreq) {
925                         qp->s_tail++;
926                         if (qp->s_tail >= qp->s_size)
927                                 qp->s_tail = 0;
928                 }
929                 if (wqe->wr.opcode == IB_WR_RDMA_READ ||
930                     wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
931                         qp->s_psn = wqe->lpsn + 1;
932                 else if (wqe->wr.opcode == IB_WR_TID_RDMA_READ)
933                         qp->s_psn = req->s_next_psn;
934                 else
935                         qp->s_psn++;
936                 break;
937
938         case OP(RDMA_READ_RESPONSE_FIRST):
939                 /*
940                  * qp->s_state is normally set to the opcode of the
941                  * last packet constructed for new requests and therefore
942                  * is never set to RDMA read response.
943                  * RDMA_READ_RESPONSE_FIRST is used by the ACK processing
944                  * thread to indicate a SEND needs to be restarted from an
945                  * earlier PSN without interfering with the sending thread.
946                  * See restart_rc().
947                  */
948                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
949                 fallthrough;
950         case OP(SEND_FIRST):
951                 qp->s_state = OP(SEND_MIDDLE);
952                 fallthrough;
953         case OP(SEND_MIDDLE):
954                 bth2 = mask_psn(qp->s_psn++);
955                 ss = &qp->s_sge;
956                 len = qp->s_len;
957                 if (len > pmtu) {
958                         len = pmtu;
959                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
960                         break;
961                 }
962                 if (wqe->wr.opcode == IB_WR_SEND) {
963                         qp->s_state = OP(SEND_LAST);
964                 } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
965                         qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
966                         /* Immediate data comes after the BTH */
967                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
968                         hwords += 1;
969                 } else {
970                         qp->s_state = OP(SEND_LAST_WITH_INVALIDATE);
971                         /* invalidate data comes after the BTH */
972                         ohdr->u.ieth = cpu_to_be32(wqe->wr.ex.invalidate_rkey);
973                         hwords += 1;
974                 }
975                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
976                         bth0 |= IB_BTH_SOLICITED;
977                 bth2 |= IB_BTH_REQ_ACK;
978                 qp->s_cur++;
979                 if (qp->s_cur >= qp->s_size)
980                         qp->s_cur = 0;
981                 break;
982
983         case OP(RDMA_READ_RESPONSE_LAST):
984                 /*
985                  * qp->s_state is normally set to the opcode of the
986                  * last packet constructed for new requests and therefore
987                  * is never set to RDMA read response.
988                  * RDMA_READ_RESPONSE_LAST is used by the ACK processing
989                  * thread to indicate a RDMA write needs to be restarted from
990                  * an earlier PSN without interfering with the sending thread.
991                  * See restart_rc().
992                  */
993                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
994                 fallthrough;
995         case OP(RDMA_WRITE_FIRST):
996                 qp->s_state = OP(RDMA_WRITE_MIDDLE);
997                 fallthrough;
998         case OP(RDMA_WRITE_MIDDLE):
999                 bth2 = mask_psn(qp->s_psn++);
1000                 ss = &qp->s_sge;
1001                 len = qp->s_len;
1002                 if (len > pmtu) {
1003                         len = pmtu;
1004                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
1005                         break;
1006                 }
1007                 if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
1008                         qp->s_state = OP(RDMA_WRITE_LAST);
1009                 } else {
1010                         qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
1011                         /* Immediate data comes after the BTH */
1012                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
1013                         hwords += 1;
1014                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
1015                                 bth0 |= IB_BTH_SOLICITED;
1016                 }
1017                 bth2 |= IB_BTH_REQ_ACK;
1018                 qp->s_cur++;
1019                 if (qp->s_cur >= qp->s_size)
1020                         qp->s_cur = 0;
1021                 break;
1022
1023         case OP(RDMA_READ_RESPONSE_MIDDLE):
1024                 /*
1025                  * qp->s_state is normally set to the opcode of the
1026                  * last packet constructed for new requests and therefore
1027                  * is never set to RDMA read response.
1028                  * RDMA_READ_RESPONSE_MIDDLE is used by the ACK processing
1029                  * thread to indicate a RDMA read needs to be restarted from
1030                  * an earlier PSN without interfering with the sending thread.
1031                  * See restart_rc().
1032                  */
1033                 len = (delta_psn(qp->s_psn, wqe->psn)) * pmtu;
1034                 put_ib_reth_vaddr(
1035                         wqe->rdma_wr.remote_addr + len,
1036                         &ohdr->u.rc.reth);
1037                 ohdr->u.rc.reth.rkey =
1038                         cpu_to_be32(wqe->rdma_wr.rkey);
1039                 ohdr->u.rc.reth.length = cpu_to_be32(wqe->length - len);
1040                 qp->s_state = OP(RDMA_READ_REQUEST);
1041                 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
1042                 bth2 = mask_psn(qp->s_psn) | IB_BTH_REQ_ACK;
1043                 qp->s_psn = wqe->lpsn + 1;
1044                 ss = NULL;
1045                 len = 0;
1046                 qp->s_cur++;
1047                 if (qp->s_cur == qp->s_size)
1048                         qp->s_cur = 0;
1049                 break;
1050
1051         case TID_OP(WRITE_RESP):
1052                 /*
1053                  * This value for s_state is used for restarting a TID RDMA
1054                  * WRITE request. See comment in OP(RDMA_READ_RESPONSE_MIDDLE
1055                  * for more).
1056                  */
1057                 req = wqe_to_tid_req(wqe);
1058                 req->state = TID_REQUEST_RESEND;
1059                 rcu_read_lock();
1060                 remote = rcu_dereference(priv->tid_rdma.remote);
1061                 req->comp_seg = delta_psn(qp->s_psn, wqe->psn);
1062                 len = wqe->length - (req->comp_seg * remote->max_len);
1063                 rcu_read_unlock();
1064
1065                 bth2 = mask_psn(qp->s_psn);
1066                 hwords += hfi1_build_tid_rdma_write_req(qp, wqe, ohdr, &bth1,
1067                                                         &bth2, &len);
1068                 qp->s_psn = wqe->lpsn + 1;
1069                 ss = NULL;
1070                 qp->s_state = TID_OP(WRITE_REQ);
1071                 priv->pending_tid_w_resp += delta_psn(wqe->lpsn, bth2) + 1;
1072                 priv->s_tid_cur = qp->s_cur;
1073                 if (++qp->s_cur == qp->s_size)
1074                         qp->s_cur = 0;
1075                 trace_hfi1_tid_req_make_req_write(qp, 0, wqe->wr.opcode,
1076                                                   wqe->psn, wqe->lpsn, req);
1077                 break;
1078
1079         case TID_OP(READ_RESP):
1080                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ)
1081                         goto bail;
1082                 /* This is used to restart a TID read request */
1083                 req = wqe_to_tid_req(wqe);
1084                 wpriv = wqe->priv;
1085                 /*
1086                  * Back down. The field qp->s_psn has been set to the psn with
1087                  * which the request should be restart. It's OK to use division
1088                  * as this is on the retry path.
1089                  */
1090                 req->cur_seg = delta_psn(qp->s_psn, wqe->psn) / priv->pkts_ps;
1091
1092                 /*
1093                  * The following function need to be redefined to return the
1094                  * status to make sure that we find the flow. At the same
1095                  * time, we can use the req->state change to check if the
1096                  * call succeeds or not.
1097                  */
1098                 req->state = TID_REQUEST_RESEND;
1099                 hfi1_tid_rdma_restart_req(qp, wqe, &bth2);
1100                 if (req->state != TID_REQUEST_ACTIVE) {
1101                         /*
1102                          * Failed to find the flow. Release all allocated tid
1103                          * resources.
1104                          */
1105                         hfi1_kern_exp_rcv_clear_all(req);
1106                         hfi1_kern_clear_hw_flow(priv->rcd, qp);
1107
1108                         hfi1_trdma_send_complete(qp, wqe, IB_WC_LOC_QP_OP_ERR);
1109                         goto bail;
1110                 }
1111                 req->state = TID_REQUEST_RESEND;
1112                 len = min_t(u32, req->seg_len,
1113                             wqe->length - req->seg_len * req->cur_seg);
1114                 flow = &req->flows[req->flow_idx];
1115                 len -= flow->sent;
1116                 req->s_next_psn = flow->flow_state.ib_lpsn + 1;
1117                 delta = hfi1_build_tid_rdma_read_packet(wqe, ohdr, &bth1,
1118                                                         &bth2, &len);
1119                 if (delta <= 0) {
1120                         /* Wait for TID space */
1121                         goto bail;
1122                 }
1123                 hwords += delta;
1124                 ss = &wpriv->ss;
1125                 /* Check if this is the last segment */
1126                 if (req->cur_seg >= req->total_segs &&
1127                     ++qp->s_cur == qp->s_size)
1128                         qp->s_cur = 0;
1129                 qp->s_psn = req->s_next_psn;
1130                 trace_hfi1_tid_req_make_req_read(qp, 0, wqe->wr.opcode,
1131                                                  wqe->psn, wqe->lpsn, req);
1132                 break;
1133         case TID_OP(READ_REQ):
1134                 req = wqe_to_tid_req(wqe);
1135                 delta = cmp_psn(qp->s_psn, wqe->psn);
1136                 /*
1137                  * If the current WR is not TID RDMA READ, or this is the start
1138                  * of a new request, we need to change the qp->s_state so that
1139                  * the request can be set up properly.
1140                  */
1141                 if (wqe->wr.opcode != IB_WR_TID_RDMA_READ || delta == 0 ||
1142                     qp->s_cur == qp->s_tail) {
1143                         qp->s_state = OP(RDMA_READ_REQUEST);
1144                         if (delta == 0 || qp->s_cur == qp->s_tail)
1145                                 goto check_s_state;
1146                         else
1147                                 goto bail;
1148                 }
1149
1150                 /* Rate limiting */
1151                 if (qp->s_num_rd_atomic >= qp->s_max_rd_atomic) {
1152                         qp->s_flags |= RVT_S_WAIT_RDMAR;
1153                         goto bail;
1154                 }
1155
1156                 wpriv = wqe->priv;
1157                 /* Read one segment at a time */
1158                 len = min_t(u32, req->seg_len,
1159                             wqe->length - req->seg_len * req->cur_seg);
1160                 delta = hfi1_build_tid_rdma_read_req(qp, wqe, ohdr, &bth1,
1161                                                      &bth2, &len);
1162                 if (delta <= 0) {
1163                         /* Wait for TID space */
1164                         goto bail;
1165                 }
1166                 hwords += delta;
1167                 ss = &wpriv->ss;
1168                 /* Check if this is the last segment */
1169                 if (req->cur_seg >= req->total_segs &&
1170                     ++qp->s_cur == qp->s_size)
1171                         qp->s_cur = 0;
1172                 qp->s_psn = req->s_next_psn;
1173                 trace_hfi1_tid_req_make_req_read(qp, 0, wqe->wr.opcode,
1174                                                  wqe->psn, wqe->lpsn, req);
1175                 break;
1176         }
1177         qp->s_sending_hpsn = bth2;
1178         delta = delta_psn(bth2, wqe->psn);
1179         if (delta && delta % HFI1_PSN_CREDIT == 0 &&
1180             wqe->wr.opcode != IB_WR_TID_RDMA_WRITE)
1181                 bth2 |= IB_BTH_REQ_ACK;
1182         if (qp->s_flags & RVT_S_SEND_ONE) {
1183                 qp->s_flags &= ~RVT_S_SEND_ONE;
1184                 qp->s_flags |= RVT_S_WAIT_ACK;
1185                 bth2 |= IB_BTH_REQ_ACK;
1186         }
1187         qp->s_len -= len;
1188         ps->s_txreq->hdr_dwords = hwords;
1189         ps->s_txreq->sde = priv->s_sde;
1190         ps->s_txreq->ss = ss;
1191         ps->s_txreq->s_cur_size = len;
1192         hfi1_make_ruc_header(
1193                 qp,
1194                 ohdr,
1195                 bth0 | (qp->s_state << 24),
1196                 bth1,
1197                 bth2,
1198                 middle,
1199                 ps);
1200         return 1;
1201
1202 done_free_tx:
1203         hfi1_put_txreq(ps->s_txreq);
1204         ps->s_txreq = NULL;
1205         return 1;
1206
1207 bail:
1208         hfi1_put_txreq(ps->s_txreq);
1209
1210 bail_no_tx:
1211         ps->s_txreq = NULL;
1212         qp->s_flags &= ~RVT_S_BUSY;
1213         /*
1214          * If we didn't get a txreq, the QP will be woken up later to try
1215          * again. Set the flags to indicate which work item to wake
1216          * up.
1217          */
1218         iowait_set_flag(&priv->s_iowait, IOWAIT_PENDING_IB);
1219         return 0;
1220 }
1221
1222 static inline void hfi1_make_bth_aeth(struct rvt_qp *qp,
1223                                       struct ib_other_headers *ohdr,
1224                                       u32 bth0, u32 bth1)
1225 {
1226         if (qp->r_nak_state)
1227                 ohdr->u.aeth = cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
1228                                             (qp->r_nak_state <<
1229                                              IB_AETH_CREDIT_SHIFT));
1230         else
1231                 ohdr->u.aeth = rvt_compute_aeth(qp);
1232
1233         ohdr->bth[0] = cpu_to_be32(bth0);
1234         ohdr->bth[1] = cpu_to_be32(bth1 | qp->remote_qpn);
1235         ohdr->bth[2] = cpu_to_be32(mask_psn(qp->r_ack_psn));
1236 }
1237
1238 static inline void hfi1_queue_rc_ack(struct hfi1_packet *packet, bool is_fecn)
1239 {
1240         struct rvt_qp *qp = packet->qp;
1241         struct hfi1_ibport *ibp;
1242         unsigned long flags;
1243
1244         spin_lock_irqsave(&qp->s_lock, flags);
1245         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
1246                 goto unlock;
1247         ibp = rcd_to_iport(packet->rcd);
1248         this_cpu_inc(*ibp->rvp.rc_qacks);
1249         qp->s_flags |= RVT_S_ACK_PENDING | RVT_S_RESP_PENDING;
1250         qp->s_nak_state = qp->r_nak_state;
1251         qp->s_ack_psn = qp->r_ack_psn;
1252         if (is_fecn)
1253                 qp->s_flags |= RVT_S_ECN;
1254
1255         /* Schedule the send tasklet. */
1256         hfi1_schedule_send(qp);
1257 unlock:
1258         spin_unlock_irqrestore(&qp->s_lock, flags);
1259 }
1260
1261 static inline void hfi1_make_rc_ack_9B(struct hfi1_packet *packet,
1262                                        struct hfi1_opa_header *opa_hdr,
1263                                        u8 sc5, bool is_fecn,
1264                                        u64 *pbc_flags, u32 *hwords,
1265                                        u32 *nwords)
1266 {
1267         struct rvt_qp *qp = packet->qp;
1268         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
1269         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1270         struct ib_header *hdr = &opa_hdr->ibh;
1271         struct ib_other_headers *ohdr;
1272         u16 lrh0 = HFI1_LRH_BTH;
1273         u16 pkey;
1274         u32 bth0, bth1;
1275
1276         opa_hdr->hdr_type = HFI1_PKT_TYPE_9B;
1277         ohdr = &hdr->u.oth;
1278         /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4 */
1279         *hwords = 6;
1280
1281         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)) {
1282                 *hwords += hfi1_make_grh(ibp, &hdr->u.l.grh,
1283                                          rdma_ah_read_grh(&qp->remote_ah_attr),
1284                                          *hwords - 2, SIZE_OF_CRC);
1285                 ohdr = &hdr->u.l.oth;
1286                 lrh0 = HFI1_LRH_GRH;
1287         }
1288         /* set PBC_DC_INFO bit (aka SC[4]) in pbc_flags */
1289         *pbc_flags |= ((!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT);
1290
1291         /* read pkey_index w/o lock (its atomic) */
1292         pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
1293
1294         lrh0 |= (sc5 & IB_SC_MASK) << IB_SC_SHIFT |
1295                 (rdma_ah_get_sl(&qp->remote_ah_attr) & IB_SL_MASK) <<
1296                         IB_SL_SHIFT;
1297
1298         hfi1_make_ib_hdr(hdr, lrh0, *hwords + SIZE_OF_CRC,
1299                          opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr), 9B),
1300                          ppd->lid | rdma_ah_get_path_bits(&qp->remote_ah_attr));
1301
1302         bth0 = pkey | (OP(ACKNOWLEDGE) << 24);
1303         if (qp->s_mig_state == IB_MIG_MIGRATED)
1304                 bth0 |= IB_BTH_MIG_REQ;
1305         bth1 = (!!is_fecn) << IB_BECN_SHIFT;
1306         /*
1307          * Inline ACKs go out without the use of the Verbs send engine, so
1308          * we need to set the STL Verbs Extended bit here
1309          */
1310         bth1 |= HFI1_CAP_IS_KSET(OPFN) << IB_BTHE_E_SHIFT;
1311         hfi1_make_bth_aeth(qp, ohdr, bth0, bth1);
1312 }
1313
1314 static inline void hfi1_make_rc_ack_16B(struct hfi1_packet *packet,
1315                                         struct hfi1_opa_header *opa_hdr,
1316                                         u8 sc5, bool is_fecn,
1317                                         u64 *pbc_flags, u32 *hwords,
1318                                         u32 *nwords)
1319 {
1320         struct rvt_qp *qp = packet->qp;
1321         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
1322         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1323         struct hfi1_16b_header *hdr = &opa_hdr->opah;
1324         struct ib_other_headers *ohdr;
1325         u32 bth0, bth1 = 0;
1326         u16 len, pkey;
1327         bool becn = is_fecn;
1328         u8 l4 = OPA_16B_L4_IB_LOCAL;
1329         u8 extra_bytes;
1330
1331         opa_hdr->hdr_type = HFI1_PKT_TYPE_16B;
1332         ohdr = &hdr->u.oth;
1333         /* header size in 32-bit words 16B LRH+BTH+AETH = (16+12+4)/4 */
1334         *hwords = 8;
1335         extra_bytes = hfi1_get_16b_padding(*hwords << 2, 0);
1336         *nwords = SIZE_OF_CRC + ((extra_bytes + SIZE_OF_LT) >> 2);
1337
1338         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
1339             hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))) {
1340                 *hwords += hfi1_make_grh(ibp, &hdr->u.l.grh,
1341                                          rdma_ah_read_grh(&qp->remote_ah_attr),
1342                                          *hwords - 4, *nwords);
1343                 ohdr = &hdr->u.l.oth;
1344                 l4 = OPA_16B_L4_IB_GLOBAL;
1345         }
1346         *pbc_flags |= PBC_PACKET_BYPASS | PBC_INSERT_BYPASS_ICRC;
1347
1348         /* read pkey_index w/o lock (its atomic) */
1349         pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
1350
1351         /* Convert dwords to flits */
1352         len = (*hwords + *nwords) >> 1;
1353
1354         hfi1_make_16b_hdr(hdr, ppd->lid |
1355                           (rdma_ah_get_path_bits(&qp->remote_ah_attr) &
1356                           ((1 << ppd->lmc) - 1)),
1357                           opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr),
1358                                       16B), len, pkey, becn, 0, l4, sc5);
1359
1360         bth0 = pkey | (OP(ACKNOWLEDGE) << 24);
1361         bth0 |= extra_bytes << 20;
1362         if (qp->s_mig_state == IB_MIG_MIGRATED)
1363                 bth1 = OPA_BTH_MIG_REQ;
1364         hfi1_make_bth_aeth(qp, ohdr, bth0, bth1);
1365 }
1366
1367 typedef void (*hfi1_make_rc_ack)(struct hfi1_packet *packet,
1368                                  struct hfi1_opa_header *opa_hdr,
1369                                  u8 sc5, bool is_fecn,
1370                                  u64 *pbc_flags, u32 *hwords,
1371                                  u32 *nwords);
1372
1373 /* We support only two types - 9B and 16B for now */
1374 static const hfi1_make_rc_ack hfi1_make_rc_ack_tbl[2] = {
1375         [HFI1_PKT_TYPE_9B] = &hfi1_make_rc_ack_9B,
1376         [HFI1_PKT_TYPE_16B] = &hfi1_make_rc_ack_16B
1377 };
1378
1379 /*
1380  * hfi1_send_rc_ack - Construct an ACK packet and send it
1381  *
1382  * This is called from hfi1_rc_rcv() and handle_receive_interrupt().
1383  * Note that RDMA reads and atomics are handled in the
1384  * send side QP state and send engine.
1385  */
1386 void hfi1_send_rc_ack(struct hfi1_packet *packet, bool is_fecn)
1387 {
1388         struct hfi1_ctxtdata *rcd = packet->rcd;
1389         struct rvt_qp *qp = packet->qp;
1390         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
1391         struct hfi1_qp_priv *priv = qp->priv;
1392         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1393         u8 sc5 = ibp->sl_to_sc[rdma_ah_get_sl(&qp->remote_ah_attr)];
1394         u64 pbc, pbc_flags = 0;
1395         u32 hwords = 0;
1396         u32 nwords = 0;
1397         u32 plen;
1398         struct pio_buf *pbuf;
1399         struct hfi1_opa_header opa_hdr;
1400
1401         /* clear the defer count */
1402         qp->r_adefered = 0;
1403
1404         /* Don't send ACK or NAK if a RDMA read or atomic is pending. */
1405         if (qp->s_flags & RVT_S_RESP_PENDING) {
1406                 hfi1_queue_rc_ack(packet, is_fecn);
1407                 return;
1408         }
1409
1410         /* Ensure s_rdma_ack_cnt changes are committed */
1411         if (qp->s_rdma_ack_cnt) {
1412                 hfi1_queue_rc_ack(packet, is_fecn);
1413                 return;
1414         }
1415
1416         /* Don't try to send ACKs if the link isn't ACTIVE */
1417         if (driver_lstate(ppd) != IB_PORT_ACTIVE)
1418                 return;
1419
1420         /* Make the appropriate header */
1421         hfi1_make_rc_ack_tbl[priv->hdr_type](packet, &opa_hdr, sc5, is_fecn,
1422                                              &pbc_flags, &hwords, &nwords);
1423
1424         plen = 2 /* PBC */ + hwords + nwords;
1425         pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps,
1426                          sc_to_vlt(ppd->dd, sc5), plen);
1427         pbuf = sc_buffer_alloc(rcd->sc, plen, NULL, NULL);
1428         if (IS_ERR_OR_NULL(pbuf)) {
1429                 /*
1430                  * We have no room to send at the moment.  Pass
1431                  * responsibility for sending the ACK to the send engine
1432                  * so that when enough buffer space becomes available,
1433                  * the ACK is sent ahead of other outgoing packets.
1434                  */
1435                 hfi1_queue_rc_ack(packet, is_fecn);
1436                 return;
1437         }
1438         trace_ack_output_ibhdr(dd_from_ibdev(qp->ibqp.device),
1439                                &opa_hdr, ib_is_sc5(sc5));
1440
1441         /* write the pbc and data */
1442         ppd->dd->pio_inline_send(ppd->dd, pbuf, pbc,
1443                                  (priv->hdr_type == HFI1_PKT_TYPE_9B ?
1444                                  (void *)&opa_hdr.ibh :
1445                                  (void *)&opa_hdr.opah), hwords);
1446         return;
1447 }
1448
1449 /**
1450  * update_num_rd_atomic - update the qp->s_num_rd_atomic
1451  * @qp: the QP
1452  * @psn: the packet sequence number to restart at
1453  * @wqe: the wqe
1454  *
1455  * This is called from reset_psn() to update qp->s_num_rd_atomic
1456  * for the current wqe.
1457  * Called at interrupt level with the QP s_lock held.
1458  */
1459 static void update_num_rd_atomic(struct rvt_qp *qp, u32 psn,
1460                                  struct rvt_swqe *wqe)
1461 {
1462         u32 opcode = wqe->wr.opcode;
1463
1464         if (opcode == IB_WR_RDMA_READ ||
1465             opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1466             opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
1467                 qp->s_num_rd_atomic++;
1468         } else if (opcode == IB_WR_TID_RDMA_READ) {
1469                 struct tid_rdma_request *req = wqe_to_tid_req(wqe);
1470                 struct hfi1_qp_priv *priv = qp->priv;
1471
1472                 if (cmp_psn(psn, wqe->lpsn) <= 0) {
1473                         u32 cur_seg;
1474
1475                         cur_seg = (psn - wqe->psn) / priv->pkts_ps;
1476                         req->ack_pending = cur_seg - req->comp_seg;
1477                         priv->pending_tid_r_segs += req->ack_pending;
1478                         qp->s_num_rd_atomic += req->ack_pending;
1479                         trace_hfi1_tid_req_update_num_rd_atomic(qp, 0,
1480                                                                 wqe->wr.opcode,
1481                                                                 wqe->psn,
1482                                                                 wqe->lpsn,
1483                                                                 req);
1484                 } else {
1485                         priv->pending_tid_r_segs += req->total_segs;
1486                         qp->s_num_rd_atomic += req->total_segs;
1487                 }
1488         }
1489 }
1490
1491 /**
1492  * reset_psn - reset the QP state to send starting from PSN
1493  * @qp: the QP
1494  * @psn: the packet sequence number to restart at
1495  *
1496  * This is called from hfi1_rc_rcv() to process an incoming RC ACK
1497  * for the given QP.
1498  * Called at interrupt level with the QP s_lock held.
1499  */
1500 static void reset_psn(struct rvt_qp *qp, u32 psn)
1501 {
1502         u32 n = qp->s_acked;
1503         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, n);
1504         u32 opcode;
1505         struct hfi1_qp_priv *priv = qp->priv;
1506
1507         lockdep_assert_held(&qp->s_lock);
1508         qp->s_cur = n;
1509         priv->pending_tid_r_segs = 0;
1510         priv->pending_tid_w_resp = 0;
1511         qp->s_num_rd_atomic = 0;
1512
1513         /*
1514          * If we are starting the request from the beginning,
1515          * let the normal send code handle initialization.
1516          */
1517         if (cmp_psn(psn, wqe->psn) <= 0) {
1518                 qp->s_state = OP(SEND_LAST);
1519                 goto done;
1520         }
1521         update_num_rd_atomic(qp, psn, wqe);
1522
1523         /* Find the work request opcode corresponding to the given PSN. */
1524         for (;;) {
1525                 int diff;
1526
1527                 if (++n == qp->s_size)
1528                         n = 0;
1529                 if (n == qp->s_tail)
1530                         break;
1531                 wqe = rvt_get_swqe_ptr(qp, n);
1532                 diff = cmp_psn(psn, wqe->psn);
1533                 if (diff < 0) {
1534                         /* Point wqe back to the previous one*/
1535                         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
1536                         break;
1537                 }
1538                 qp->s_cur = n;
1539                 /*
1540                  * If we are starting the request from the beginning,
1541                  * let the normal send code handle initialization.
1542                  */
1543                 if (diff == 0) {
1544                         qp->s_state = OP(SEND_LAST);
1545                         goto done;
1546                 }
1547
1548                 update_num_rd_atomic(qp, psn, wqe);
1549         }
1550         opcode = wqe->wr.opcode;
1551
1552         /*
1553          * Set the state to restart in the middle of a request.
1554          * Don't change the s_sge, s_cur_sge, or s_cur_size.
1555          * See hfi1_make_rc_req().
1556          */
1557         switch (opcode) {
1558         case IB_WR_SEND:
1559         case IB_WR_SEND_WITH_IMM:
1560                 qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
1561                 break;
1562
1563         case IB_WR_RDMA_WRITE:
1564         case IB_WR_RDMA_WRITE_WITH_IMM:
1565                 qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
1566                 break;
1567
1568         case IB_WR_TID_RDMA_WRITE:
1569                 qp->s_state = TID_OP(WRITE_RESP);
1570                 break;
1571
1572         case IB_WR_RDMA_READ:
1573                 qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
1574                 break;
1575
1576         case IB_WR_TID_RDMA_READ:
1577                 qp->s_state = TID_OP(READ_RESP);
1578                 break;
1579
1580         default:
1581                 /*
1582                  * This case shouldn't happen since its only
1583                  * one PSN per req.
1584                  */
1585                 qp->s_state = OP(SEND_LAST);
1586         }
1587 done:
1588         priv->s_flags &= ~HFI1_S_TID_WAIT_INTERLCK;
1589         qp->s_psn = psn;
1590         /*
1591          * Set RVT_S_WAIT_PSN as rc_complete() may start the timer
1592          * asynchronously before the send engine can get scheduled.
1593          * Doing it in hfi1_make_rc_req() is too late.
1594          */
1595         if ((cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) &&
1596             (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0))
1597                 qp->s_flags |= RVT_S_WAIT_PSN;
1598         qp->s_flags &= ~HFI1_S_AHG_VALID;
1599         trace_hfi1_sender_reset_psn(qp);
1600 }
1601
1602 /*
1603  * Back up requester to resend the last un-ACKed request.
1604  * The QP r_lock and s_lock should be held and interrupts disabled.
1605  */
1606 void hfi1_restart_rc(struct rvt_qp *qp, u32 psn, int wait)
1607 {
1608         struct hfi1_qp_priv *priv = qp->priv;
1609         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1610         struct hfi1_ibport *ibp;
1611
1612         lockdep_assert_held(&qp->r_lock);
1613         lockdep_assert_held(&qp->s_lock);
1614         trace_hfi1_sender_restart_rc(qp);
1615         if (qp->s_retry == 0) {
1616                 if (qp->s_mig_state == IB_MIG_ARMED) {
1617                         hfi1_migrate_qp(qp);
1618                         qp->s_retry = qp->s_retry_cnt;
1619                 } else if (qp->s_last == qp->s_acked) {
1620                         /*
1621                          * We need special handling for the OPFN request WQEs as
1622                          * they are not allowed to generate real user errors
1623                          */
1624                         if (wqe->wr.opcode == IB_WR_OPFN) {
1625                                 struct hfi1_ibport *ibp =
1626                                         to_iport(qp->ibqp.device, qp->port_num);
1627                                 /*
1628                                  * Call opfn_conn_reply() with capcode and
1629                                  * remaining data as 0 to close out the
1630                                  * current request
1631                                  */
1632                                 opfn_conn_reply(qp, priv->opfn.curr);
1633                                 wqe = do_rc_completion(qp, wqe, ibp);
1634                                 qp->s_flags &= ~RVT_S_WAIT_ACK;
1635                         } else {
1636                                 trace_hfi1_tid_write_sender_restart_rc(qp, 0);
1637                                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ) {
1638                                         struct tid_rdma_request *req;
1639
1640                                         req = wqe_to_tid_req(wqe);
1641                                         hfi1_kern_exp_rcv_clear_all(req);
1642                                         hfi1_kern_clear_hw_flow(priv->rcd, qp);
1643                                 }
1644
1645                                 hfi1_trdma_send_complete(qp, wqe,
1646                                                          IB_WC_RETRY_EXC_ERR);
1647                                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1648                         }
1649                         return;
1650                 } else { /* need to handle delayed completion */
1651                         return;
1652                 }
1653         } else {
1654                 qp->s_retry--;
1655         }
1656
1657         ibp = to_iport(qp->ibqp.device, qp->port_num);
1658         if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1659             wqe->wr.opcode == IB_WR_TID_RDMA_READ)
1660                 ibp->rvp.n_rc_resends++;
1661         else
1662                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
1663
1664         qp->s_flags &= ~(RVT_S_WAIT_FENCE | RVT_S_WAIT_RDMAR |
1665                          RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_PSN |
1666                          RVT_S_WAIT_ACK | HFI1_S_WAIT_TID_RESP);
1667         if (wait)
1668                 qp->s_flags |= RVT_S_SEND_ONE;
1669         reset_psn(qp, psn);
1670 }
1671
1672 /*
1673  * Set qp->s_sending_psn to the next PSN after the given one.
1674  * This would be psn+1 except when RDMA reads or TID RDMA ops
1675  * are present.
1676  */
1677 static void reset_sending_psn(struct rvt_qp *qp, u32 psn)
1678 {
1679         struct rvt_swqe *wqe;
1680         u32 n = qp->s_last;
1681
1682         lockdep_assert_held(&qp->s_lock);
1683         /* Find the work request corresponding to the given PSN. */
1684         for (;;) {
1685                 wqe = rvt_get_swqe_ptr(qp, n);
1686                 if (cmp_psn(psn, wqe->lpsn) <= 0) {
1687                         if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1688                             wqe->wr.opcode == IB_WR_TID_RDMA_READ ||
1689                             wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
1690                                 qp->s_sending_psn = wqe->lpsn + 1;
1691                         else
1692                                 qp->s_sending_psn = psn + 1;
1693                         break;
1694                 }
1695                 if (++n == qp->s_size)
1696                         n = 0;
1697                 if (n == qp->s_tail)
1698                         break;
1699         }
1700 }
1701
1702 /**
1703  * hfi1_rc_verbs_aborted - handle abort status
1704  * @qp: the QP
1705  * @opah: the opa header
1706  *
1707  * This code modifies both ACK bit in BTH[2]
1708  * and the s_flags to go into send one mode.
1709  *
1710  * This serves to throttle the send engine to only
1711  * send a single packet in the likely case the
1712  * a link has gone down.
1713  */
1714 void hfi1_rc_verbs_aborted(struct rvt_qp *qp, struct hfi1_opa_header *opah)
1715 {
1716         struct ib_other_headers *ohdr = hfi1_get_rc_ohdr(opah);
1717         u8 opcode = ib_bth_get_opcode(ohdr);
1718         u32 psn;
1719
1720         /* ignore responses */
1721         if ((opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1722              opcode <= OP(ATOMIC_ACKNOWLEDGE)) ||
1723             opcode == TID_OP(READ_RESP) ||
1724             opcode == TID_OP(WRITE_RESP))
1725                 return;
1726
1727         psn = ib_bth_get_psn(ohdr) | IB_BTH_REQ_ACK;
1728         ohdr->bth[2] = cpu_to_be32(psn);
1729         qp->s_flags |= RVT_S_SEND_ONE;
1730 }
1731
1732 /*
1733  * This should be called with the QP s_lock held and interrupts disabled.
1734  */
1735 void hfi1_rc_send_complete(struct rvt_qp *qp, struct hfi1_opa_header *opah)
1736 {
1737         struct ib_other_headers *ohdr;
1738         struct hfi1_qp_priv *priv = qp->priv;
1739         struct rvt_swqe *wqe;
1740         u32 opcode, head, tail;
1741         u32 psn;
1742         struct tid_rdma_request *req;
1743
1744         lockdep_assert_held(&qp->s_lock);
1745         if (!(ib_rvt_state_ops[qp->state] & RVT_SEND_OR_FLUSH_OR_RECV_OK))
1746                 return;
1747
1748         ohdr = hfi1_get_rc_ohdr(opah);
1749         opcode = ib_bth_get_opcode(ohdr);
1750         if ((opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1751              opcode <= OP(ATOMIC_ACKNOWLEDGE)) ||
1752             opcode == TID_OP(READ_RESP) ||
1753             opcode == TID_OP(WRITE_RESP)) {
1754                 WARN_ON(!qp->s_rdma_ack_cnt);
1755                 qp->s_rdma_ack_cnt--;
1756                 return;
1757         }
1758
1759         psn = ib_bth_get_psn(ohdr);
1760         /*
1761          * Don't attempt to reset the sending PSN for packets in the
1762          * KDETH PSN space since the PSN does not match anything.
1763          */
1764         if (opcode != TID_OP(WRITE_DATA) &&
1765             opcode != TID_OP(WRITE_DATA_LAST) &&
1766             opcode != TID_OP(ACK) && opcode != TID_OP(RESYNC))
1767                 reset_sending_psn(qp, psn);
1768
1769         /* Handle TID RDMA WRITE packets differently */
1770         if (opcode >= TID_OP(WRITE_REQ) &&
1771             opcode <= TID_OP(WRITE_DATA_LAST)) {
1772                 head = priv->s_tid_head;
1773                 tail = priv->s_tid_cur;
1774                 /*
1775                  * s_tid_cur is set to s_tid_head in the case, where
1776                  * a new TID RDMA request is being started and all
1777                  * previous ones have been completed.
1778                  * Therefore, we need to do a secondary check in order
1779                  * to properly determine whether we should start the
1780                  * RC timer.
1781                  */
1782                 wqe = rvt_get_swqe_ptr(qp, tail);
1783                 req = wqe_to_tid_req(wqe);
1784                 if (head == tail && req->comp_seg < req->total_segs) {
1785                         if (tail == 0)
1786                                 tail = qp->s_size - 1;
1787                         else
1788                                 tail -= 1;
1789                 }
1790         } else {
1791                 head = qp->s_tail;
1792                 tail = qp->s_acked;
1793         }
1794
1795         /*
1796          * Start timer after a packet requesting an ACK has been sent and
1797          * there are still requests that haven't been acked.
1798          */
1799         if ((psn & IB_BTH_REQ_ACK) && tail != head &&
1800             opcode != TID_OP(WRITE_DATA) && opcode != TID_OP(WRITE_DATA_LAST) &&
1801             opcode != TID_OP(RESYNC) &&
1802             !(qp->s_flags &
1803               (RVT_S_TIMER | RVT_S_WAIT_RNR | RVT_S_WAIT_PSN)) &&
1804             (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
1805                 if (opcode == TID_OP(READ_REQ))
1806                         rvt_add_retry_timer_ext(qp, priv->timeout_shift);
1807                 else
1808                         rvt_add_retry_timer(qp);
1809         }
1810
1811         /* Start TID RDMA ACK timer */
1812         if ((opcode == TID_OP(WRITE_DATA) ||
1813              opcode == TID_OP(WRITE_DATA_LAST) ||
1814              opcode == TID_OP(RESYNC)) &&
1815             (psn & IB_BTH_REQ_ACK) &&
1816             !(priv->s_flags & HFI1_S_TID_RETRY_TIMER) &&
1817             (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
1818                 /*
1819                  * The TID RDMA ACK packet could be received before this
1820                  * function is called. Therefore, add the timer only if TID
1821                  * RDMA ACK packets are actually pending.
1822                  */
1823                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1824                 req = wqe_to_tid_req(wqe);
1825                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
1826                     req->ack_seg < req->cur_seg)
1827                         hfi1_add_tid_retry_timer(qp);
1828         }
1829
1830         while (qp->s_last != qp->s_acked) {
1831                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
1832                 if (cmp_psn(wqe->lpsn, qp->s_sending_psn) >= 0 &&
1833                     cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)
1834                         break;
1835                 trdma_clean_swqe(qp, wqe);
1836                 trace_hfi1_qp_send_completion(qp, wqe, qp->s_last);
1837                 rvt_qp_complete_swqe(qp,
1838                                      wqe,
1839                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1840                                      IB_WC_SUCCESS);
1841         }
1842         /*
1843          * If we were waiting for sends to complete before re-sending,
1844          * and they are now complete, restart sending.
1845          */
1846         trace_hfi1_sendcomplete(qp, psn);
1847         if (qp->s_flags & RVT_S_WAIT_PSN &&
1848             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1849                 qp->s_flags &= ~RVT_S_WAIT_PSN;
1850                 qp->s_sending_psn = qp->s_psn;
1851                 qp->s_sending_hpsn = qp->s_psn - 1;
1852                 hfi1_schedule_send(qp);
1853         }
1854 }
1855
1856 static inline void update_last_psn(struct rvt_qp *qp, u32 psn)
1857 {
1858         qp->s_last_psn = psn;
1859 }
1860
1861 /*
1862  * Generate a SWQE completion.
1863  * This is similar to hfi1_send_complete but has to check to be sure
1864  * that the SGEs are not being referenced if the SWQE is being resent.
1865  */
1866 struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
1867                                   struct rvt_swqe *wqe,
1868                                   struct hfi1_ibport *ibp)
1869 {
1870         struct hfi1_qp_priv *priv = qp->priv;
1871
1872         lockdep_assert_held(&qp->s_lock);
1873         /*
1874          * Don't decrement refcount and don't generate a
1875          * completion if the SWQE is being resent until the send
1876          * is finished.
1877          */
1878         trace_hfi1_rc_completion(qp, wqe->lpsn);
1879         if (cmp_psn(wqe->lpsn, qp->s_sending_psn) < 0 ||
1880             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1881                 trdma_clean_swqe(qp, wqe);
1882                 trace_hfi1_qp_send_completion(qp, wqe, qp->s_last);
1883                 rvt_qp_complete_swqe(qp,
1884                                      wqe,
1885                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1886                                      IB_WC_SUCCESS);
1887         } else {
1888                 struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1889
1890                 this_cpu_inc(*ibp->rvp.rc_delayed_comp);
1891                 /*
1892                  * If send progress not running attempt to progress
1893                  * SDMA queue.
1894                  */
1895                 if (ppd->dd->flags & HFI1_HAS_SEND_DMA) {
1896                         struct sdma_engine *engine;
1897                         u8 sl = rdma_ah_get_sl(&qp->remote_ah_attr);
1898                         u8 sc5;
1899
1900                         /* For now use sc to find engine */
1901                         sc5 = ibp->sl_to_sc[sl];
1902                         engine = qp_to_sdma_engine(qp, sc5);
1903                         sdma_engine_progress_schedule(engine);
1904                 }
1905         }
1906
1907         qp->s_retry = qp->s_retry_cnt;
1908         /*
1909          * Don't update the last PSN if the request being completed is
1910          * a TID RDMA WRITE request.
1911          * Completion of the TID RDMA WRITE requests are done by the
1912          * TID RDMA ACKs and as such could be for a request that has
1913          * already been ACKed as far as the IB state machine is
1914          * concerned.
1915          */
1916         if (wqe->wr.opcode != IB_WR_TID_RDMA_WRITE)
1917                 update_last_psn(qp, wqe->lpsn);
1918
1919         /*
1920          * If we are completing a request which is in the process of
1921          * being resent, we can stop re-sending it since we know the
1922          * responder has already seen it.
1923          */
1924         if (qp->s_acked == qp->s_cur) {
1925                 if (++qp->s_cur >= qp->s_size)
1926                         qp->s_cur = 0;
1927                 qp->s_acked = qp->s_cur;
1928                 wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
1929                 if (qp->s_acked != qp->s_tail) {
1930                         qp->s_state = OP(SEND_LAST);
1931                         qp->s_psn = wqe->psn;
1932                 }
1933         } else {
1934                 if (++qp->s_acked >= qp->s_size)
1935                         qp->s_acked = 0;
1936                 if (qp->state == IB_QPS_SQD && qp->s_acked == qp->s_cur)
1937                         qp->s_draining = 0;
1938                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1939         }
1940         if (priv->s_flags & HFI1_S_TID_WAIT_INTERLCK) {
1941                 priv->s_flags &= ~HFI1_S_TID_WAIT_INTERLCK;
1942                 hfi1_schedule_send(qp);
1943         }
1944         return wqe;
1945 }
1946
1947 static void set_restart_qp(struct rvt_qp *qp, struct hfi1_ctxtdata *rcd)
1948 {
1949         /* Retry this request. */
1950         if (!(qp->r_flags & RVT_R_RDMAR_SEQ)) {
1951                 qp->r_flags |= RVT_R_RDMAR_SEQ;
1952                 hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
1953                 if (list_empty(&qp->rspwait)) {
1954                         qp->r_flags |= RVT_R_RSP_SEND;
1955                         rvt_get_qp(qp);
1956                         list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1957                 }
1958         }
1959 }
1960
1961 /**
1962  * update_qp_retry_state - Update qp retry state.
1963  * @qp: the QP
1964  * @psn: the packet sequence number of the TID RDMA WRITE RESP.
1965  * @spsn:  The start psn for the given TID RDMA WRITE swqe.
1966  * @lpsn:  The last psn for the given TID RDMA WRITE swqe.
1967  *
1968  * This function is called to update the qp retry state upon
1969  * receiving a TID WRITE RESP after the qp is scheduled to retry
1970  * a request.
1971  */
1972 static void update_qp_retry_state(struct rvt_qp *qp, u32 psn, u32 spsn,
1973                                   u32 lpsn)
1974 {
1975         struct hfi1_qp_priv *qpriv = qp->priv;
1976
1977         qp->s_psn = psn + 1;
1978         /*
1979          * If this is the first TID RDMA WRITE RESP packet for the current
1980          * request, change the s_state so that the retry will be processed
1981          * correctly. Similarly, if this is the last TID RDMA WRITE RESP
1982          * packet, change the s_state and advance the s_cur.
1983          */
1984         if (cmp_psn(psn, lpsn) >= 0) {
1985                 qp->s_cur = qpriv->s_tid_cur + 1;
1986                 if (qp->s_cur >= qp->s_size)
1987                         qp->s_cur = 0;
1988                 qp->s_state = TID_OP(WRITE_REQ);
1989         } else  if (!cmp_psn(psn, spsn)) {
1990                 qp->s_cur = qpriv->s_tid_cur;
1991                 qp->s_state = TID_OP(WRITE_RESP);
1992         }
1993 }
1994
1995 /*
1996  * do_rc_ack - process an incoming RC ACK
1997  * @qp: the QP the ACK came in on
1998  * @psn: the packet sequence number of the ACK
1999  * @opcode: the opcode of the request that resulted in the ACK
2000  *
2001  * This is called from rc_rcv_resp() to process an incoming RC ACK
2002  * for the given QP.
2003  * May be called at interrupt level, with the QP s_lock held.
2004  * Returns 1 if OK, 0 if current operation should be aborted (NAK).
2005  */
2006 int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode,
2007               u64 val, struct hfi1_ctxtdata *rcd)
2008 {
2009         struct hfi1_ibport *ibp;
2010         enum ib_wc_status status;
2011         struct hfi1_qp_priv *qpriv = qp->priv;
2012         struct rvt_swqe *wqe;
2013         int ret = 0;
2014         u32 ack_psn;
2015         int diff;
2016         struct rvt_dev_info *rdi;
2017
2018         lockdep_assert_held(&qp->s_lock);
2019         /*
2020          * Note that NAKs implicitly ACK outstanding SEND and RDMA write
2021          * requests and implicitly NAK RDMA read and atomic requests issued
2022          * before the NAK'ed request.  The MSN won't include the NAK'ed
2023          * request but will include an ACK'ed request(s).
2024          */
2025         ack_psn = psn;
2026         if (aeth >> IB_AETH_NAK_SHIFT)
2027                 ack_psn--;
2028         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2029         ibp = rcd_to_iport(rcd);
2030
2031         /*
2032          * The MSN might be for a later WQE than the PSN indicates so
2033          * only complete WQEs that the PSN finishes.
2034          */
2035         while ((diff = delta_psn(ack_psn, wqe->lpsn)) >= 0) {
2036                 /*
2037                  * RDMA_READ_RESPONSE_ONLY is a special case since
2038                  * we want to generate completion events for everything
2039                  * before the RDMA read, copy the data, then generate
2040                  * the completion for the read.
2041                  */
2042                 if (wqe->wr.opcode == IB_WR_RDMA_READ &&
2043                     opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
2044                     diff == 0) {
2045                         ret = 1;
2046                         goto bail_stop;
2047                 }
2048                 /*
2049                  * If this request is a RDMA read or atomic, and the ACK is
2050                  * for a later operation, this ACK NAKs the RDMA read or
2051                  * atomic.  In other words, only a RDMA_READ_LAST or ONLY
2052                  * can ACK a RDMA read and likewise for atomic ops.  Note
2053                  * that the NAK case can only happen if relaxed ordering is
2054                  * used and requests are sent after an RDMA read or atomic
2055                  * is sent but before the response is received.
2056                  */
2057                 if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
2058                      (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
2059                     (wqe->wr.opcode == IB_WR_TID_RDMA_READ &&
2060                      (opcode != TID_OP(READ_RESP) || diff != 0)) ||
2061                     ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2062                       wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
2063                      (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0)) ||
2064                     (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2065                      (delta_psn(psn, qp->s_last_psn) != 1))) {
2066                         set_restart_qp(qp, rcd);
2067                         /*
2068                          * No need to process the ACK/NAK since we are
2069                          * restarting an earlier request.
2070                          */
2071                         goto bail_stop;
2072                 }
2073                 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2074                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
2075                         u64 *vaddr = wqe->sg_list[0].vaddr;
2076                         *vaddr = val;
2077                 }
2078                 if (wqe->wr.opcode == IB_WR_OPFN)
2079                         opfn_conn_reply(qp, val);
2080
2081                 if (qp->s_num_rd_atomic &&
2082                     (wqe->wr.opcode == IB_WR_RDMA_READ ||
2083                      wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2084                      wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
2085                         qp->s_num_rd_atomic--;
2086                         /* Restart sending task if fence is complete */
2087                         if ((qp->s_flags & RVT_S_WAIT_FENCE) &&
2088                             !qp->s_num_rd_atomic) {
2089                                 qp->s_flags &= ~(RVT_S_WAIT_FENCE |
2090                                                  RVT_S_WAIT_ACK);
2091                                 hfi1_schedule_send(qp);
2092                         } else if (qp->s_flags & RVT_S_WAIT_RDMAR) {
2093                                 qp->s_flags &= ~(RVT_S_WAIT_RDMAR |
2094                                                  RVT_S_WAIT_ACK);
2095                                 hfi1_schedule_send(qp);
2096                         }
2097                 }
2098
2099                 /*
2100                  * TID RDMA WRITE requests will be completed by the TID RDMA
2101                  * ACK packet handler (see tid_rdma.c).
2102                  */
2103                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE)
2104                         break;
2105
2106                 wqe = do_rc_completion(qp, wqe, ibp);
2107                 if (qp->s_acked == qp->s_tail)
2108                         break;
2109         }
2110
2111         trace_hfi1_rc_ack_do(qp, aeth, psn, wqe);
2112         trace_hfi1_sender_do_rc_ack(qp);
2113         switch (aeth >> IB_AETH_NAK_SHIFT) {
2114         case 0:         /* ACK */
2115                 this_cpu_inc(*ibp->rvp.rc_acks);
2116                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ) {
2117                         if (wqe_to_tid_req(wqe)->ack_pending)
2118                                 rvt_mod_retry_timer_ext(qp,
2119                                                         qpriv->timeout_shift);
2120                         else
2121                                 rvt_stop_rc_timers(qp);
2122                 } else if (qp->s_acked != qp->s_tail) {
2123                         struct rvt_swqe *__w = NULL;
2124
2125                         if (qpriv->s_tid_cur != HFI1_QP_WQE_INVALID)
2126                                 __w = rvt_get_swqe_ptr(qp, qpriv->s_tid_cur);
2127
2128                         /*
2129                          * Stop timers if we've received all of the TID RDMA
2130                          * WRITE * responses.
2131                          */
2132                         if (__w && __w->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2133                             opcode == TID_OP(WRITE_RESP)) {
2134                                 /*
2135                                  * Normally, the loop above would correctly
2136                                  * process all WQEs from s_acked onward and
2137                                  * either complete them or check for correct
2138                                  * PSN sequencing.
2139                                  * However, for TID RDMA, due to pipelining,
2140                                  * the response may not be for the request at
2141                                  * s_acked so the above look would just be
2142                                  * skipped. This does not allow for checking
2143                                  * the PSN sequencing. It has to be done
2144                                  * separately.
2145                                  */
2146                                 if (cmp_psn(psn, qp->s_last_psn + 1)) {
2147                                         set_restart_qp(qp, rcd);
2148                                         goto bail_stop;
2149                                 }
2150                                 /*
2151                                  * If the psn is being resent, stop the
2152                                  * resending.
2153                                  */
2154                                 if (qp->s_cur != qp->s_tail &&
2155                                     cmp_psn(qp->s_psn, psn) <= 0)
2156                                         update_qp_retry_state(qp, psn,
2157                                                               __w->psn,
2158                                                               __w->lpsn);
2159                                 else if (--qpriv->pending_tid_w_resp)
2160                                         rvt_mod_retry_timer(qp);
2161                                 else
2162                                         rvt_stop_rc_timers(qp);
2163                         } else {
2164                                 /*
2165                                  * We are expecting more ACKs so
2166                                  * mod the retry timer.
2167                                  */
2168                                 rvt_mod_retry_timer(qp);
2169                                 /*
2170                                  * We can stop re-sending the earlier packets
2171                                  * and continue with the next packet the
2172                                  * receiver wants.
2173                                  */
2174                                 if (cmp_psn(qp->s_psn, psn) <= 0)
2175                                         reset_psn(qp, psn + 1);
2176                         }
2177                 } else {
2178                         /* No more acks - kill all timers */
2179                         rvt_stop_rc_timers(qp);
2180                         if (cmp_psn(qp->s_psn, psn) <= 0) {
2181                                 qp->s_state = OP(SEND_LAST);
2182                                 qp->s_psn = psn + 1;
2183                         }
2184                 }
2185                 if (qp->s_flags & RVT_S_WAIT_ACK) {
2186                         qp->s_flags &= ~RVT_S_WAIT_ACK;
2187                         hfi1_schedule_send(qp);
2188                 }
2189                 rvt_get_credit(qp, aeth);
2190                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
2191                 qp->s_retry = qp->s_retry_cnt;
2192                 /*
2193                  * If the current request is a TID RDMA WRITE request and the
2194                  * response is not a TID RDMA WRITE RESP packet, s_last_psn
2195                  * can't be advanced.
2196                  */
2197                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE &&
2198                     opcode != TID_OP(WRITE_RESP) &&
2199                     cmp_psn(psn, wqe->psn) >= 0)
2200                         return 1;
2201                 update_last_psn(qp, psn);
2202                 return 1;
2203
2204         case 1:         /* RNR NAK */
2205                 ibp->rvp.n_rnr_naks++;
2206                 if (qp->s_acked == qp->s_tail)
2207                         goto bail_stop;
2208                 if (qp->s_flags & RVT_S_WAIT_RNR)
2209                         goto bail_stop;
2210                 rdi = ib_to_rvt(qp->ibqp.device);
2211                 if (!(rdi->post_parms[wqe->wr.opcode].flags &
2212                        RVT_OPERATION_IGN_RNR_CNT)) {
2213                         if (qp->s_rnr_retry == 0) {
2214                                 status = IB_WC_RNR_RETRY_EXC_ERR;
2215                                 goto class_b;
2216                         }
2217                         if (qp->s_rnr_retry_cnt < 7 && qp->s_rnr_retry_cnt > 0)
2218                                 qp->s_rnr_retry--;
2219                 }
2220
2221                 /*
2222                  * The last valid PSN is the previous PSN. For TID RDMA WRITE
2223                  * request, s_last_psn should be incremented only when a TID
2224                  * RDMA WRITE RESP is received to avoid skipping lost TID RDMA
2225                  * WRITE RESP packets.
2226                  */
2227                 if (wqe->wr.opcode == IB_WR_TID_RDMA_WRITE) {
2228                         reset_psn(qp, qp->s_last_psn + 1);
2229                 } else {
2230                         update_last_psn(qp, psn - 1);
2231                         reset_psn(qp, psn);
2232                 }
2233
2234                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
2235                 qp->s_flags &= ~(RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_ACK);
2236                 rvt_stop_rc_timers(qp);
2237                 rvt_add_rnr_timer(qp, aeth);
2238                 return 0;
2239
2240         case 3:         /* NAK */
2241                 if (qp->s_acked == qp->s_tail)
2242                         goto bail_stop;
2243                 /* The last valid PSN is the previous PSN. */
2244                 update_last_psn(qp, psn - 1);
2245                 switch ((aeth >> IB_AETH_CREDIT_SHIFT) &
2246                         IB_AETH_CREDIT_MASK) {
2247                 case 0: /* PSN sequence error */
2248                         ibp->rvp.n_seq_naks++;
2249                         /*
2250                          * Back up to the responder's expected PSN.
2251                          * Note that we might get a NAK in the middle of an
2252                          * RDMA READ response which terminates the RDMA
2253                          * READ.
2254                          */
2255                         hfi1_restart_rc(qp, psn, 0);
2256                         hfi1_schedule_send(qp);
2257                         break;
2258
2259                 case 1: /* Invalid Request */
2260                         status = IB_WC_REM_INV_REQ_ERR;
2261                         ibp->rvp.n_other_naks++;
2262                         goto class_b;
2263
2264                 case 2: /* Remote Access Error */
2265                         status = IB_WC_REM_ACCESS_ERR;
2266                         ibp->rvp.n_other_naks++;
2267                         goto class_b;
2268
2269                 case 3: /* Remote Operation Error */
2270                         status = IB_WC_REM_OP_ERR;
2271                         ibp->rvp.n_other_naks++;
2272 class_b:
2273                         if (qp->s_last == qp->s_acked) {
2274                                 if (wqe->wr.opcode == IB_WR_TID_RDMA_READ)
2275                                         hfi1_kern_read_tid_flow_free(qp);
2276
2277                                 hfi1_trdma_send_complete(qp, wqe, status);
2278                                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
2279                         }
2280                         break;
2281
2282                 default:
2283                         /* Ignore other reserved NAK error codes */
2284                         goto reserved;
2285                 }
2286                 qp->s_retry = qp->s_retry_cnt;
2287                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
2288                 goto bail_stop;
2289
2290         default:                /* 2: reserved */
2291 reserved:
2292                 /* Ignore reserved NAK codes. */
2293                 goto bail_stop;
2294         }
2295         /* cannot be reached  */
2296 bail_stop:
2297         rvt_stop_rc_timers(qp);
2298         return ret;
2299 }
2300
2301 /*
2302  * We have seen an out of sequence RDMA read middle or last packet.
2303  * This ACKs SENDs and RDMA writes up to the first RDMA read or atomic SWQE.
2304  */
2305 static void rdma_seq_err(struct rvt_qp *qp, struct hfi1_ibport *ibp, u32 psn,
2306                          struct hfi1_ctxtdata *rcd)
2307 {
2308         struct rvt_swqe *wqe;
2309
2310         lockdep_assert_held(&qp->s_lock);
2311         /* Remove QP from retry timer */
2312         rvt_stop_rc_timers(qp);
2313
2314         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2315
2316         while (cmp_psn(psn, wqe->lpsn) > 0) {
2317                 if (wqe->wr.opcode == IB_WR_RDMA_READ ||
2318                     wqe->wr.opcode == IB_WR_TID_RDMA_READ ||
2319                     wqe->wr.opcode == IB_WR_TID_RDMA_WRITE ||
2320                     wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
2321                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
2322                         break;
2323                 wqe = do_rc_completion(qp, wqe, ibp);
2324         }
2325
2326         ibp->rvp.n_rdma_seq++;
2327         qp->r_flags |= RVT_R_RDMAR_SEQ;
2328         hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
2329         if (list_empty(&qp->rspwait)) {
2330                 qp->r_flags |= RVT_R_RSP_SEND;
2331                 rvt_get_qp(qp);
2332                 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
2333         }
2334 }
2335
2336 /**
2337  * rc_rcv_resp - process an incoming RC response packet
2338  * @packet: data packet information
2339  *
2340  * This is called from hfi1_rc_rcv() to process an incoming RC response
2341  * packet for the given QP.
2342  * Called at interrupt level.
2343  */
2344 static void rc_rcv_resp(struct hfi1_packet *packet)
2345 {
2346         struct hfi1_ctxtdata *rcd = packet->rcd;
2347         void *data = packet->payload;
2348         u32 tlen = packet->tlen;
2349         struct rvt_qp *qp = packet->qp;
2350         struct hfi1_ibport *ibp;
2351         struct ib_other_headers *ohdr = packet->ohdr;
2352         struct rvt_swqe *wqe;
2353         enum ib_wc_status status;
2354         unsigned long flags;
2355         int diff;
2356         u64 val;
2357         u32 aeth;
2358         u32 psn = ib_bth_get_psn(packet->ohdr);
2359         u32 pmtu = qp->pmtu;
2360         u16 hdrsize = packet->hlen;
2361         u8 opcode = packet->opcode;
2362         u8 pad = packet->pad;
2363         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
2364
2365         spin_lock_irqsave(&qp->s_lock, flags);
2366         trace_hfi1_ack(qp, psn);
2367
2368         /* Ignore invalid responses. */
2369         if (cmp_psn(psn, READ_ONCE(qp->s_next_psn)) >= 0)
2370                 goto ack_done;
2371
2372         /* Ignore duplicate responses. */
2373         diff = cmp_psn(psn, qp->s_last_psn);
2374         if (unlikely(diff <= 0)) {
2375                 /* Update credits for "ghost" ACKs */
2376                 if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
2377                         aeth = be32_to_cpu(ohdr->u.aeth);
2378                         if ((aeth >> IB_AETH_NAK_SHIFT) == 0)
2379                                 rvt_get_credit(qp, aeth);
2380                 }
2381                 goto ack_done;
2382         }
2383
2384         /*
2385          * Skip everything other than the PSN we expect, if we are waiting
2386          * for a reply to a restarted RDMA read or atomic op.
2387          */
2388         if (qp->r_flags & RVT_R_RDMAR_SEQ) {
2389                 if (cmp_psn(psn, qp->s_last_psn + 1) != 0)
2390                         goto ack_done;
2391                 qp->r_flags &= ~RVT_R_RDMAR_SEQ;
2392         }
2393
2394         if (unlikely(qp->s_acked == qp->s_tail))
2395                 goto ack_done;
2396         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2397         status = IB_WC_SUCCESS;
2398
2399         switch (opcode) {
2400         case OP(ACKNOWLEDGE):
2401         case OP(ATOMIC_ACKNOWLEDGE):
2402         case OP(RDMA_READ_RESPONSE_FIRST):
2403                 aeth = be32_to_cpu(ohdr->u.aeth);
2404                 if (opcode == OP(ATOMIC_ACKNOWLEDGE))
2405                         val = ib_u64_get(&ohdr->u.at.atomic_ack_eth);
2406                 else
2407                         val = 0;
2408                 if (!do_rc_ack(qp, aeth, psn, opcode, val, rcd) ||
2409                     opcode != OP(RDMA_READ_RESPONSE_FIRST))
2410                         goto ack_done;
2411                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2412                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2413                         goto ack_op_err;
2414                 /*
2415                  * If this is a response to a resent RDMA read, we
2416                  * have to be careful to copy the data to the right
2417                  * location.
2418                  */
2419                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
2420                                                   wqe, psn, pmtu);
2421                 goto read_middle;
2422
2423         case OP(RDMA_READ_RESPONSE_MIDDLE):
2424                 /* no AETH, no ACK */
2425                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
2426                         goto ack_seq_err;
2427                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2428                         goto ack_op_err;
2429 read_middle:
2430                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
2431                         goto ack_len_err;
2432                 if (unlikely(pmtu >= qp->s_rdma_read_len))
2433                         goto ack_len_err;
2434
2435                 /*
2436                  * We got a response so update the timeout.
2437                  * 4.096 usec. * (1 << qp->timeout)
2438                  */
2439                 rvt_mod_retry_timer(qp);
2440                 if (qp->s_flags & RVT_S_WAIT_ACK) {
2441                         qp->s_flags &= ~RVT_S_WAIT_ACK;
2442                         hfi1_schedule_send(qp);
2443                 }
2444
2445                 if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
2446                         qp->s_retry = qp->s_retry_cnt;
2447
2448                 /*
2449                  * Update the RDMA receive state but do the copy w/o
2450                  * holding the locks and blocking interrupts.
2451                  */
2452                 qp->s_rdma_read_len -= pmtu;
2453                 update_last_psn(qp, psn);
2454                 spin_unlock_irqrestore(&qp->s_lock, flags);
2455                 rvt_copy_sge(qp, &qp->s_rdma_read_sge,
2456                              data, pmtu, false, false);
2457                 goto bail;
2458
2459         case OP(RDMA_READ_RESPONSE_ONLY):
2460                 aeth = be32_to_cpu(ohdr->u.aeth);
2461                 if (!do_rc_ack(qp, aeth, psn, opcode, 0, rcd))
2462                         goto ack_done;
2463                 /*
2464                  * Check that the data size is >= 0 && <= pmtu.
2465                  * Remember to account for ICRC (4).
2466                  */
2467                 if (unlikely(tlen < (hdrsize + extra_bytes)))
2468                         goto ack_len_err;
2469                 /*
2470                  * If this is a response to a resent RDMA read, we
2471                  * have to be careful to copy the data to the right
2472                  * location.
2473                  */
2474                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
2475                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
2476                                                   wqe, psn, pmtu);
2477                 goto read_last;
2478
2479         case OP(RDMA_READ_RESPONSE_LAST):
2480                 /* ACKs READ req. */
2481                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
2482                         goto ack_seq_err;
2483                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
2484                         goto ack_op_err;
2485                 /*
2486                  * Check that the data size is >= 1 && <= pmtu.
2487                  * Remember to account for ICRC (4).
2488                  */
2489                 if (unlikely(tlen <= (hdrsize + extra_bytes)))
2490                         goto ack_len_err;
2491 read_last:
2492                 tlen -= hdrsize + extra_bytes;
2493                 if (unlikely(tlen != qp->s_rdma_read_len))
2494                         goto ack_len_err;
2495                 aeth = be32_to_cpu(ohdr->u.aeth);
2496                 rvt_copy_sge(qp, &qp->s_rdma_read_sge,
2497                              data, tlen, false, false);
2498                 WARN_ON(qp->s_rdma_read_sge.num_sge);
2499                 (void)do_rc_ack(qp, aeth, psn,
2500                                  OP(RDMA_READ_RESPONSE_LAST), 0, rcd);
2501                 goto ack_done;
2502         }
2503
2504 ack_op_err:
2505         status = IB_WC_LOC_QP_OP_ERR;
2506         goto ack_err;
2507
2508 ack_seq_err:
2509         ibp = rcd_to_iport(rcd);
2510         rdma_seq_err(qp, ibp, psn, rcd);
2511         goto ack_done;
2512
2513 ack_len_err:
2514         status = IB_WC_LOC_LEN_ERR;
2515 ack_err:
2516         if (qp->s_last == qp->s_acked) {
2517                 rvt_send_complete(qp, wqe, status);
2518                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
2519         }
2520 ack_done:
2521         spin_unlock_irqrestore(&qp->s_lock, flags);
2522 bail:
2523         return;
2524 }
2525
2526 static inline void rc_cancel_ack(struct rvt_qp *qp)
2527 {
2528         qp->r_adefered = 0;
2529         if (list_empty(&qp->rspwait))
2530                 return;
2531         list_del_init(&qp->rspwait);
2532         qp->r_flags &= ~RVT_R_RSP_NAK;
2533         rvt_put_qp(qp);
2534 }
2535
2536 /**
2537  * rc_rcv_error - process an incoming duplicate or error RC packet
2538  * @ohdr: the other headers for this packet
2539  * @data: the packet data
2540  * @qp: the QP for this packet
2541  * @opcode: the opcode for this packet
2542  * @psn: the packet sequence number for this packet
2543  * @diff: the difference between the PSN and the expected PSN
2544  * @rcd: the receive context
2545  *
2546  * This is called from hfi1_rc_rcv() to process an unexpected
2547  * incoming RC packet for the given QP.
2548  * Called at interrupt level.
2549  * Return 1 if no more processing is needed; otherwise return 0 to
2550  * schedule a response to be sent.
2551  */
2552 static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
2553                                  struct rvt_qp *qp, u32 opcode, u32 psn,
2554                                  int diff, struct hfi1_ctxtdata *rcd)
2555 {
2556         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
2557         struct rvt_ack_entry *e;
2558         unsigned long flags;
2559         u8 prev;
2560         u8 mra; /* most recent ACK */
2561         bool old_req;
2562
2563         trace_hfi1_rcv_error(qp, psn);
2564         if (diff > 0) {
2565                 /*
2566                  * Packet sequence error.
2567                  * A NAK will ACK earlier sends and RDMA writes.
2568                  * Don't queue the NAK if we already sent one.
2569                  */
2570                 if (!qp->r_nak_state) {
2571                         ibp->rvp.n_rc_seqnak++;
2572                         qp->r_nak_state = IB_NAK_PSN_ERROR;
2573                         /* Use the expected PSN. */
2574                         qp->r_ack_psn = qp->r_psn;
2575                         /*
2576                          * Wait to send the sequence NAK until all packets
2577                          * in the receive queue have been processed.
2578                          * Otherwise, we end up propagating congestion.
2579                          */
2580                         rc_defered_ack(rcd, qp);
2581                 }
2582                 goto done;
2583         }
2584
2585         /*
2586          * Handle a duplicate request.  Don't re-execute SEND, RDMA
2587          * write or atomic op.  Don't NAK errors, just silently drop
2588          * the duplicate request.  Note that r_sge, r_len, and
2589          * r_rcv_len may be in use so don't modify them.
2590          *
2591          * We are supposed to ACK the earliest duplicate PSN but we
2592          * can coalesce an outstanding duplicate ACK.  We have to
2593          * send the earliest so that RDMA reads can be restarted at
2594          * the requester's expected PSN.
2595          *
2596          * First, find where this duplicate PSN falls within the
2597          * ACKs previously sent.
2598          * old_req is true if there is an older response that is scheduled
2599          * to be sent before sending this one.
2600          */
2601         e = NULL;
2602         old_req = true;
2603         ibp->rvp.n_rc_dupreq++;
2604
2605         spin_lock_irqsave(&qp->s_lock, flags);
2606
2607         e = find_prev_entry(qp, psn, &prev, &mra, &old_req);
2608
2609         switch (opcode) {
2610         case OP(RDMA_READ_REQUEST): {
2611                 struct ib_reth *reth;
2612                 u32 offset;
2613                 u32 len;
2614
2615                 /*
2616                  * If we didn't find the RDMA read request in the ack queue,
2617                  * we can ignore this request.
2618                  */
2619                 if (!e || e->opcode != OP(RDMA_READ_REQUEST))
2620                         goto unlock_done;
2621                 /* RETH comes after BTH */
2622                 reth = &ohdr->u.rc.reth;
2623                 /*
2624                  * Address range must be a subset of the original
2625                  * request and start on pmtu boundaries.
2626                  * We reuse the old ack_queue slot since the requester
2627                  * should not back up and request an earlier PSN for the
2628                  * same request.
2629                  */
2630                 offset = delta_psn(psn, e->psn) * qp->pmtu;
2631                 len = be32_to_cpu(reth->length);
2632                 if (unlikely(offset + len != e->rdma_sge.sge_length))
2633                         goto unlock_done;
2634                 release_rdma_sge_mr(e);
2635                 if (len != 0) {
2636                         u32 rkey = be32_to_cpu(reth->rkey);
2637                         u64 vaddr = get_ib_reth_vaddr(reth);
2638                         int ok;
2639
2640                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey,
2641                                          IB_ACCESS_REMOTE_READ);
2642                         if (unlikely(!ok))
2643                                 goto unlock_done;
2644                 } else {
2645                         e->rdma_sge.vaddr = NULL;
2646                         e->rdma_sge.length = 0;
2647                         e->rdma_sge.sge_length = 0;
2648                 }
2649                 e->psn = psn;
2650                 if (old_req)
2651                         goto unlock_done;
2652                 if (qp->s_acked_ack_queue == qp->s_tail_ack_queue)
2653                         qp->s_acked_ack_queue = prev;
2654                 qp->s_tail_ack_queue = prev;
2655                 break;
2656         }
2657
2658         case OP(COMPARE_SWAP):
2659         case OP(FETCH_ADD): {
2660                 /*
2661                  * If we didn't find the atomic request in the ack queue
2662                  * or the send engine is already backed up to send an
2663                  * earlier entry, we can ignore this request.
2664                  */
2665                 if (!e || e->opcode != (u8)opcode || old_req)
2666                         goto unlock_done;
2667                 if (qp->s_tail_ack_queue == qp->s_acked_ack_queue)
2668                         qp->s_acked_ack_queue = prev;
2669                 qp->s_tail_ack_queue = prev;
2670                 break;
2671         }
2672
2673         default:
2674                 /*
2675                  * Ignore this operation if it doesn't request an ACK
2676                  * or an earlier RDMA read or atomic is going to be resent.
2677                  */
2678                 if (!(psn & IB_BTH_REQ_ACK) || old_req)
2679                         goto unlock_done;
2680                 /*
2681                  * Resend the most recent ACK if this request is
2682                  * after all the previous RDMA reads and atomics.
2683                  */
2684                 if (mra == qp->r_head_ack_queue) {
2685                         spin_unlock_irqrestore(&qp->s_lock, flags);
2686                         qp->r_nak_state = 0;
2687                         qp->r_ack_psn = qp->r_psn - 1;
2688                         goto send_ack;
2689                 }
2690
2691                 /*
2692                  * Resend the RDMA read or atomic op which
2693                  * ACKs this duplicate request.
2694                  */
2695                 if (qp->s_tail_ack_queue == qp->s_acked_ack_queue)
2696                         qp->s_acked_ack_queue = mra;
2697                 qp->s_tail_ack_queue = mra;
2698                 break;
2699         }
2700         qp->s_ack_state = OP(ACKNOWLEDGE);
2701         qp->s_flags |= RVT_S_RESP_PENDING;
2702         qp->r_nak_state = 0;
2703         hfi1_schedule_send(qp);
2704
2705 unlock_done:
2706         spin_unlock_irqrestore(&qp->s_lock, flags);
2707 done:
2708         return 1;
2709
2710 send_ack:
2711         return 0;
2712 }
2713
2714 static void log_cca_event(struct hfi1_pportdata *ppd, u8 sl, u32 rlid,
2715                           u32 lqpn, u32 rqpn, u8 svc_type)
2716 {
2717         struct opa_hfi1_cong_log_event_internal *cc_event;
2718         unsigned long flags;
2719
2720         if (sl >= OPA_MAX_SLS)
2721                 return;
2722
2723         spin_lock_irqsave(&ppd->cc_log_lock, flags);
2724
2725         ppd->threshold_cong_event_map[sl / 8] |= 1 << (sl % 8);
2726         ppd->threshold_event_counter++;
2727
2728         cc_event = &ppd->cc_events[ppd->cc_log_idx++];
2729         if (ppd->cc_log_idx == OPA_CONG_LOG_ELEMS)
2730                 ppd->cc_log_idx = 0;
2731         cc_event->lqpn = lqpn & RVT_QPN_MASK;
2732         cc_event->rqpn = rqpn & RVT_QPN_MASK;
2733         cc_event->sl = sl;
2734         cc_event->svc_type = svc_type;
2735         cc_event->rlid = rlid;
2736         /* keep timestamp in units of 1.024 usec */
2737         cc_event->timestamp = ktime_get_ns() / 1024;
2738
2739         spin_unlock_irqrestore(&ppd->cc_log_lock, flags);
2740 }
2741
2742 void process_becn(struct hfi1_pportdata *ppd, u8 sl, u32 rlid, u32 lqpn,
2743                   u32 rqpn, u8 svc_type)
2744 {
2745         struct cca_timer *cca_timer;
2746         u16 ccti, ccti_incr, ccti_timer, ccti_limit;
2747         u8 trigger_threshold;
2748         struct cc_state *cc_state;
2749         unsigned long flags;
2750
2751         if (sl >= OPA_MAX_SLS)
2752                 return;
2753
2754         cc_state = get_cc_state(ppd);
2755
2756         if (!cc_state)
2757                 return;
2758
2759         /*
2760          * 1) increase CCTI (for this SL)
2761          * 2) select IPG (i.e., call set_link_ipg())
2762          * 3) start timer
2763          */
2764         ccti_limit = cc_state->cct.ccti_limit;
2765         ccti_incr = cc_state->cong_setting.entries[sl].ccti_increase;
2766         ccti_timer = cc_state->cong_setting.entries[sl].ccti_timer;
2767         trigger_threshold =
2768                 cc_state->cong_setting.entries[sl].trigger_threshold;
2769
2770         spin_lock_irqsave(&ppd->cca_timer_lock, flags);
2771
2772         cca_timer = &ppd->cca_timer[sl];
2773         if (cca_timer->ccti < ccti_limit) {
2774                 if (cca_timer->ccti + ccti_incr <= ccti_limit)
2775                         cca_timer->ccti += ccti_incr;
2776                 else
2777                         cca_timer->ccti = ccti_limit;
2778                 set_link_ipg(ppd);
2779         }
2780
2781         ccti = cca_timer->ccti;
2782
2783         if (!hrtimer_active(&cca_timer->hrtimer)) {
2784                 /* ccti_timer is in units of 1.024 usec */
2785                 unsigned long nsec = 1024 * ccti_timer;
2786
2787                 hrtimer_start(&cca_timer->hrtimer, ns_to_ktime(nsec),
2788                               HRTIMER_MODE_REL_PINNED);
2789         }
2790
2791         spin_unlock_irqrestore(&ppd->cca_timer_lock, flags);
2792
2793         if ((trigger_threshold != 0) && (ccti >= trigger_threshold))
2794                 log_cca_event(ppd, sl, rlid, lqpn, rqpn, svc_type);
2795 }
2796
2797 /**
2798  * hfi1_rc_rcv - process an incoming RC packet
2799  * @packet: data packet information
2800  *
2801  * This is called from qp_rcv() to process an incoming RC packet
2802  * for the given QP.
2803  * May be called at interrupt level.
2804  */
2805 void hfi1_rc_rcv(struct hfi1_packet *packet)
2806 {
2807         struct hfi1_ctxtdata *rcd = packet->rcd;
2808         void *data = packet->payload;
2809         u32 tlen = packet->tlen;
2810         struct rvt_qp *qp = packet->qp;
2811         struct hfi1_qp_priv *qpriv = qp->priv;
2812         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
2813         struct ib_other_headers *ohdr = packet->ohdr;
2814         u32 opcode = packet->opcode;
2815         u32 hdrsize = packet->hlen;
2816         u32 psn = ib_bth_get_psn(packet->ohdr);
2817         u32 pad = packet->pad;
2818         struct ib_wc wc;
2819         u32 pmtu = qp->pmtu;
2820         int diff;
2821         struct ib_reth *reth;
2822         unsigned long flags;
2823         int ret;
2824         bool copy_last = false, fecn;
2825         u32 rkey;
2826         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
2827
2828         lockdep_assert_held(&qp->r_lock);
2829
2830         if (hfi1_ruc_check_hdr(ibp, packet))
2831                 return;
2832
2833         fecn = process_ecn(qp, packet);
2834         opfn_trigger_conn_request(qp, be32_to_cpu(ohdr->bth[1]));
2835
2836         /*
2837          * Process responses (ACKs) before anything else.  Note that the
2838          * packet sequence number will be for something in the send work
2839          * queue rather than the expected receive packet sequence number.
2840          * In other words, this QP is the requester.
2841          */
2842         if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
2843             opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
2844                 rc_rcv_resp(packet);
2845                 return;
2846         }
2847
2848         /* Compute 24 bits worth of difference. */
2849         diff = delta_psn(psn, qp->r_psn);
2850         if (unlikely(diff)) {
2851                 if (rc_rcv_error(ohdr, data, qp, opcode, psn, diff, rcd))
2852                         return;
2853                 goto send_ack;
2854         }
2855
2856         /* Check for opcode sequence errors. */
2857         switch (qp->r_state) {
2858         case OP(SEND_FIRST):
2859         case OP(SEND_MIDDLE):
2860                 if (opcode == OP(SEND_MIDDLE) ||
2861                     opcode == OP(SEND_LAST) ||
2862                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2863                     opcode == OP(SEND_LAST_WITH_INVALIDATE))
2864                         break;
2865                 goto nack_inv;
2866
2867         case OP(RDMA_WRITE_FIRST):
2868         case OP(RDMA_WRITE_MIDDLE):
2869                 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
2870                     opcode == OP(RDMA_WRITE_LAST) ||
2871                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2872                         break;
2873                 goto nack_inv;
2874
2875         default:
2876                 if (opcode == OP(SEND_MIDDLE) ||
2877                     opcode == OP(SEND_LAST) ||
2878                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2879                     opcode == OP(SEND_LAST_WITH_INVALIDATE) ||
2880                     opcode == OP(RDMA_WRITE_MIDDLE) ||
2881                     opcode == OP(RDMA_WRITE_LAST) ||
2882                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2883                         goto nack_inv;
2884                 /*
2885                  * Note that it is up to the requester to not send a new
2886                  * RDMA read or atomic operation before receiving an ACK
2887                  * for the previous operation.
2888                  */
2889                 break;
2890         }
2891
2892         if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
2893                 rvt_comm_est(qp);
2894
2895         /* OK, process the packet. */
2896         switch (opcode) {
2897         case OP(SEND_FIRST):
2898                 ret = rvt_get_rwqe(qp, false);
2899                 if (ret < 0)
2900                         goto nack_op_err;
2901                 if (!ret)
2902                         goto rnr_nak;
2903                 qp->r_rcv_len = 0;
2904                 fallthrough;
2905         case OP(SEND_MIDDLE):
2906         case OP(RDMA_WRITE_MIDDLE):
2907 send_middle:
2908                 /* Check for invalid length PMTU or posted rwqe len. */
2909                 /*
2910                  * There will be no padding for 9B packet but 16B packets
2911                  * will come in with some padding since we always add
2912                  * CRC and LT bytes which will need to be flit aligned
2913                  */
2914                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
2915                         goto nack_inv;
2916                 qp->r_rcv_len += pmtu;
2917                 if (unlikely(qp->r_rcv_len > qp->r_len))
2918                         goto nack_inv;
2919                 rvt_copy_sge(qp, &qp->r_sge, data, pmtu, true, false);
2920                 break;
2921
2922         case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
2923                 /* consume RWQE */
2924                 ret = rvt_get_rwqe(qp, true);
2925                 if (ret < 0)
2926                         goto nack_op_err;
2927                 if (!ret)
2928                         goto rnr_nak;
2929                 goto send_last_imm;
2930
2931         case OP(SEND_ONLY):
2932         case OP(SEND_ONLY_WITH_IMMEDIATE):
2933         case OP(SEND_ONLY_WITH_INVALIDATE):
2934                 ret = rvt_get_rwqe(qp, false);
2935                 if (ret < 0)
2936                         goto nack_op_err;
2937                 if (!ret)
2938                         goto rnr_nak;
2939                 qp->r_rcv_len = 0;
2940                 if (opcode == OP(SEND_ONLY))
2941                         goto no_immediate_data;
2942                 if (opcode == OP(SEND_ONLY_WITH_INVALIDATE))
2943                         goto send_last_inv;
2944                 fallthrough;    /* for SEND_ONLY_WITH_IMMEDIATE */
2945         case OP(SEND_LAST_WITH_IMMEDIATE):
2946 send_last_imm:
2947                 wc.ex.imm_data = ohdr->u.imm_data;
2948                 wc.wc_flags = IB_WC_WITH_IMM;
2949                 goto send_last;
2950         case OP(SEND_LAST_WITH_INVALIDATE):
2951 send_last_inv:
2952                 rkey = be32_to_cpu(ohdr->u.ieth);
2953                 if (rvt_invalidate_rkey(qp, rkey))
2954                         goto no_immediate_data;
2955                 wc.ex.invalidate_rkey = rkey;
2956                 wc.wc_flags = IB_WC_WITH_INVALIDATE;
2957                 goto send_last;
2958         case OP(RDMA_WRITE_LAST):
2959                 copy_last = rvt_is_user_qp(qp);
2960                 fallthrough;
2961         case OP(SEND_LAST):
2962 no_immediate_data:
2963                 wc.wc_flags = 0;
2964                 wc.ex.imm_data = 0;
2965 send_last:
2966                 /* Check for invalid length. */
2967                 /* LAST len should be >= 1 */
2968                 if (unlikely(tlen < (hdrsize + extra_bytes)))
2969                         goto nack_inv;
2970                 /* Don't count the CRC(and padding and LT byte for 16B). */
2971                 tlen -= (hdrsize + extra_bytes);
2972                 wc.byte_len = tlen + qp->r_rcv_len;
2973                 if (unlikely(wc.byte_len > qp->r_len))
2974                         goto nack_inv;
2975                 rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, copy_last);
2976                 rvt_put_ss(&qp->r_sge);
2977                 qp->r_msn++;
2978                 if (!__test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
2979                         break;
2980                 wc.wr_id = qp->r_wr_id;
2981                 wc.status = IB_WC_SUCCESS;
2982                 if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
2983                     opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
2984                         wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
2985                 else
2986                         wc.opcode = IB_WC_RECV;
2987                 wc.qp = &qp->ibqp;
2988                 wc.src_qp = qp->remote_qpn;
2989                 wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
2990                 /*
2991                  * It seems that IB mandates the presence of an SL in a
2992                  * work completion only for the UD transport (see section
2993                  * 11.4.2 of IBTA Vol. 1).
2994                  *
2995                  * However, the way the SL is chosen below is consistent
2996                  * with the way that IB/qib works and is trying avoid
2997                  * introducing incompatibilities.
2998                  *
2999                  * See also OPA Vol. 1, section 9.7.6, and table 9-17.
3000                  */
3001                 wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
3002                 /* zero fields that are N/A */
3003                 wc.vendor_err = 0;
3004                 wc.pkey_index = 0;
3005                 wc.dlid_path_bits = 0;
3006                 wc.port_num = 0;
3007                 /* Signal completion event if the solicited bit is set. */
3008                 rvt_recv_cq(qp, &wc, ib_bth_is_solicited(ohdr));
3009                 break;
3010
3011         case OP(RDMA_WRITE_ONLY):
3012                 copy_last = rvt_is_user_qp(qp);
3013                 fallthrough;
3014         case OP(RDMA_WRITE_FIRST):
3015         case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
3016                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
3017                         goto nack_inv;
3018                 /* consume RWQE */
3019                 reth = &ohdr->u.rc.reth;
3020                 qp->r_len = be32_to_cpu(reth->length);
3021                 qp->r_rcv_len = 0;
3022                 qp->r_sge.sg_list = NULL;
3023                 if (qp->r_len != 0) {
3024                         u32 rkey = be32_to_cpu(reth->rkey);
3025                         u64 vaddr = get_ib_reth_vaddr(reth);
3026                         int ok;
3027
3028                         /* Check rkey & NAK */
3029                         ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len, vaddr,
3030                                          rkey, IB_ACCESS_REMOTE_WRITE);
3031                         if (unlikely(!ok))
3032                                 goto nack_acc;
3033                         qp->r_sge.num_sge = 1;
3034                 } else {
3035                         qp->r_sge.num_sge = 0;
3036                         qp->r_sge.sge.mr = NULL;
3037                         qp->r_sge.sge.vaddr = NULL;
3038                         qp->r_sge.sge.length = 0;
3039                         qp->r_sge.sge.sge_length = 0;
3040                 }
3041                 if (opcode == OP(RDMA_WRITE_FIRST))
3042                         goto send_middle;
3043                 else if (opcode == OP(RDMA_WRITE_ONLY))
3044                         goto no_immediate_data;
3045                 ret = rvt_get_rwqe(qp, true);
3046                 if (ret < 0)
3047                         goto nack_op_err;
3048                 if (!ret) {
3049                         /* peer will send again */
3050                         rvt_put_ss(&qp->r_sge);
3051                         goto rnr_nak;
3052                 }
3053                 wc.ex.imm_data = ohdr->u.rc.imm_data;
3054                 wc.wc_flags = IB_WC_WITH_IMM;
3055                 goto send_last;
3056
3057         case OP(RDMA_READ_REQUEST): {
3058                 struct rvt_ack_entry *e;
3059                 u32 len;
3060                 u8 next;
3061
3062                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
3063                         goto nack_inv;
3064                 next = qp->r_head_ack_queue + 1;
3065                 /* s_ack_queue is size rvt_size_atomic()+1 so use > not >= */
3066                 if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
3067                         next = 0;
3068                 spin_lock_irqsave(&qp->s_lock, flags);
3069                 if (unlikely(next == qp->s_acked_ack_queue)) {
3070                         if (!qp->s_ack_queue[next].sent)
3071                                 goto nack_inv_unlck;
3072                         update_ack_queue(qp, next);
3073                 }
3074                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
3075                 release_rdma_sge_mr(e);
3076                 reth = &ohdr->u.rc.reth;
3077                 len = be32_to_cpu(reth->length);
3078                 if (len) {
3079                         u32 rkey = be32_to_cpu(reth->rkey);
3080                         u64 vaddr = get_ib_reth_vaddr(reth);
3081                         int ok;
3082
3083                         /* Check rkey & NAK */
3084                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr,
3085                                          rkey, IB_ACCESS_REMOTE_READ);
3086                         if (unlikely(!ok))
3087                                 goto nack_acc_unlck;
3088                         /*
3089                          * Update the next expected PSN.  We add 1 later
3090                          * below, so only add the remainder here.
3091                          */
3092                         qp->r_psn += rvt_div_mtu(qp, len - 1);
3093                 } else {
3094                         e->rdma_sge.mr = NULL;
3095                         e->rdma_sge.vaddr = NULL;
3096                         e->rdma_sge.length = 0;
3097                         e->rdma_sge.sge_length = 0;
3098                 }
3099                 e->opcode = opcode;
3100                 e->sent = 0;
3101                 e->psn = psn;
3102                 e->lpsn = qp->r_psn;
3103                 /*
3104                  * We need to increment the MSN here instead of when we
3105                  * finish sending the result since a duplicate request would
3106                  * increment it more than once.
3107                  */
3108                 qp->r_msn++;
3109                 qp->r_psn++;
3110                 qp->r_state = opcode;
3111                 qp->r_nak_state = 0;
3112                 qp->r_head_ack_queue = next;
3113                 qpriv->r_tid_alloc = qp->r_head_ack_queue;
3114
3115                 /* Schedule the send engine. */
3116                 qp->s_flags |= RVT_S_RESP_PENDING;
3117                 if (fecn)
3118                         qp->s_flags |= RVT_S_ECN;
3119                 hfi1_schedule_send(qp);
3120
3121                 spin_unlock_irqrestore(&qp->s_lock, flags);
3122                 return;
3123         }
3124
3125         case OP(COMPARE_SWAP):
3126         case OP(FETCH_ADD): {
3127                 struct ib_atomic_eth *ateth = &ohdr->u.atomic_eth;
3128                 u64 vaddr = get_ib_ateth_vaddr(ateth);
3129                 bool opfn = opcode == OP(COMPARE_SWAP) &&
3130                         vaddr == HFI1_VERBS_E_ATOMIC_VADDR;
3131                 struct rvt_ack_entry *e;
3132                 atomic64_t *maddr;
3133                 u64 sdata;
3134                 u32 rkey;
3135                 u8 next;
3136
3137                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC) &&
3138                              !opfn))
3139                         goto nack_inv;
3140                 next = qp->r_head_ack_queue + 1;
3141                 if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
3142                         next = 0;
3143                 spin_lock_irqsave(&qp->s_lock, flags);
3144                 if (unlikely(next == qp->s_acked_ack_queue)) {
3145                         if (!qp->s_ack_queue[next].sent)
3146                                 goto nack_inv_unlck;
3147                         update_ack_queue(qp, next);
3148                 }
3149                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
3150                 release_rdma_sge_mr(e);
3151                 /* Process OPFN special virtual address */
3152                 if (opfn) {
3153                         opfn_conn_response(qp, e, ateth);
3154                         goto ack;
3155                 }
3156                 if (unlikely(vaddr & (sizeof(u64) - 1)))
3157                         goto nack_inv_unlck;
3158                 rkey = be32_to_cpu(ateth->rkey);
3159                 /* Check rkey & NAK */
3160                 if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
3161                                           vaddr, rkey,
3162                                           IB_ACCESS_REMOTE_ATOMIC)))
3163                         goto nack_acc_unlck;
3164                 /* Perform atomic OP and save result. */
3165                 maddr = (atomic64_t *)qp->r_sge.sge.vaddr;
3166                 sdata = get_ib_ateth_swap(ateth);
3167                 e->atomic_data = (opcode == OP(FETCH_ADD)) ?
3168                         (u64)atomic64_add_return(sdata, maddr) - sdata :
3169                         (u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr,
3170                                       get_ib_ateth_compare(ateth),
3171                                       sdata);
3172                 rvt_put_mr(qp->r_sge.sge.mr);
3173                 qp->r_sge.num_sge = 0;
3174 ack:
3175                 e->opcode = opcode;
3176                 e->sent = 0;
3177                 e->psn = psn;
3178                 e->lpsn = psn;
3179                 qp->r_msn++;
3180                 qp->r_psn++;
3181                 qp->r_state = opcode;
3182                 qp->r_nak_state = 0;
3183                 qp->r_head_ack_queue = next;
3184                 qpriv->r_tid_alloc = qp->r_head_ack_queue;
3185
3186                 /* Schedule the send engine. */
3187                 qp->s_flags |= RVT_S_RESP_PENDING;
3188                 if (fecn)
3189                         qp->s_flags |= RVT_S_ECN;
3190                 hfi1_schedule_send(qp);
3191
3192                 spin_unlock_irqrestore(&qp->s_lock, flags);
3193                 return;
3194         }
3195
3196         default:
3197                 /* NAK unknown opcodes. */
3198                 goto nack_inv;
3199         }
3200         qp->r_psn++;
3201         qp->r_state = opcode;
3202         qp->r_ack_psn = psn;
3203         qp->r_nak_state = 0;
3204         /* Send an ACK if requested or required. */
3205         if (psn & IB_BTH_REQ_ACK || fecn) {
3206                 if (packet->numpkt == 0 || fecn ||
3207                     qp->r_adefered >= HFI1_PSN_CREDIT) {
3208                         rc_cancel_ack(qp);
3209                         goto send_ack;
3210                 }
3211                 qp->r_adefered++;
3212                 rc_defered_ack(rcd, qp);
3213         }
3214         return;
3215
3216 rnr_nak:
3217         qp->r_nak_state = qp->r_min_rnr_timer | IB_RNR_NAK;
3218         qp->r_ack_psn = qp->r_psn;
3219         /* Queue RNR NAK for later */
3220         rc_defered_ack(rcd, qp);
3221         return;
3222
3223 nack_op_err:
3224         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
3225         qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR;
3226         qp->r_ack_psn = qp->r_psn;
3227         /* Queue NAK for later */
3228         rc_defered_ack(rcd, qp);
3229         return;
3230
3231 nack_inv_unlck:
3232         spin_unlock_irqrestore(&qp->s_lock, flags);
3233 nack_inv:
3234         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
3235         qp->r_nak_state = IB_NAK_INVALID_REQUEST;
3236         qp->r_ack_psn = qp->r_psn;
3237         /* Queue NAK for later */
3238         rc_defered_ack(rcd, qp);
3239         return;
3240
3241 nack_acc_unlck:
3242         spin_unlock_irqrestore(&qp->s_lock, flags);
3243 nack_acc:
3244         rvt_rc_error(qp, IB_WC_LOC_PROT_ERR);
3245         qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
3246         qp->r_ack_psn = qp->r_psn;
3247 send_ack:
3248         hfi1_send_rc_ack(packet, fecn);
3249 }
3250
3251 void hfi1_rc_hdrerr(
3252         struct hfi1_ctxtdata *rcd,
3253         struct hfi1_packet *packet,
3254         struct rvt_qp *qp)
3255 {
3256         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
3257         int diff;
3258         u32 opcode;
3259         u32 psn;
3260
3261         if (hfi1_ruc_check_hdr(ibp, packet))
3262                 return;
3263
3264         psn = ib_bth_get_psn(packet->ohdr);
3265         opcode = ib_bth_get_opcode(packet->ohdr);
3266
3267         /* Only deal with RDMA Writes for now */
3268         if (opcode < IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) {
3269                 diff = delta_psn(psn, qp->r_psn);
3270                 if (!qp->r_nak_state && diff >= 0) {
3271                         ibp->rvp.n_rc_seqnak++;
3272                         qp->r_nak_state = IB_NAK_PSN_ERROR;
3273                         /* Use the expected PSN. */
3274                         qp->r_ack_psn = qp->r_psn;
3275                         /*
3276                          * Wait to send the sequence
3277                          * NAK until all packets
3278                          * in the receive queue have
3279                          * been processed.
3280                          * Otherwise, we end up
3281                          * propagating congestion.
3282                          */
3283                         rc_defered_ack(rcd, qp);
3284                 } /* Out of sequence NAK */
3285         } /* QP Request NAKs */
3286 }