Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
[sfrench/cifs-2.6.git] / drivers / infiniband / hw / hfi1 / rc.c
1 /*
2  * Copyright(c) 2015, 2016 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 "verbs_txreq.h"
55 #include "trace.h"
56
57 /* cut down ridiculously long IB macro names */
58 #define OP(x) RC_OP(x)
59
60 static u32 restart_sge(struct rvt_sge_state *ss, struct rvt_swqe *wqe,
61                        u32 psn, u32 pmtu)
62 {
63         u32 len;
64
65         len = delta_psn(psn, wqe->psn) * pmtu;
66         ss->sge = wqe->sg_list[0];
67         ss->sg_list = wqe->sg_list + 1;
68         ss->num_sge = wqe->wr.num_sge;
69         ss->total_len = wqe->length;
70         rvt_skip_sge(ss, len, false);
71         return wqe->length - len;
72 }
73
74 /**
75  * make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
76  * @dev: the device for this QP
77  * @qp: a pointer to the QP
78  * @ohdr: a pointer to the IB header being constructed
79  * @ps: the xmit packet state
80  *
81  * Return 1 if constructed; otherwise, return 0.
82  * Note that we are in the responder's side of the QP context.
83  * Note the QP s_lock must be held.
84  */
85 static int make_rc_ack(struct hfi1_ibdev *dev, struct rvt_qp *qp,
86                        struct ib_other_headers *ohdr,
87                        struct hfi1_pkt_state *ps)
88 {
89         struct rvt_ack_entry *e;
90         u32 hwords;
91         u32 len;
92         u32 bth0;
93         u32 bth2;
94         int middle = 0;
95         u32 pmtu = qp->pmtu;
96         struct hfi1_qp_priv *priv = qp->priv;
97
98         lockdep_assert_held(&qp->s_lock);
99         /* Don't send an ACK if we aren't supposed to. */
100         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
101                 goto bail;
102
103         if (priv->hdr_type == HFI1_PKT_TYPE_9B)
104                 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
105                 hwords = 5;
106         else
107                 /* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
108                 hwords = 7;
109
110         switch (qp->s_ack_state) {
111         case OP(RDMA_READ_RESPONSE_LAST):
112         case OP(RDMA_READ_RESPONSE_ONLY):
113                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
114                 if (e->rdma_sge.mr) {
115                         rvt_put_mr(e->rdma_sge.mr);
116                         e->rdma_sge.mr = NULL;
117                 }
118                 /* FALLTHROUGH */
119         case OP(ATOMIC_ACKNOWLEDGE):
120                 /*
121                  * We can increment the tail pointer now that the last
122                  * response has been sent instead of only being
123                  * constructed.
124                  */
125                 if (++qp->s_tail_ack_queue > HFI1_MAX_RDMA_ATOMIC)
126                         qp->s_tail_ack_queue = 0;
127                 /* FALLTHROUGH */
128         case OP(SEND_ONLY):
129         case OP(ACKNOWLEDGE):
130                 /* Check for no next entry in the queue. */
131                 if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
132                         if (qp->s_flags & RVT_S_ACK_PENDING)
133                                 goto normal;
134                         goto bail;
135                 }
136
137                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
138                 if (e->opcode == OP(RDMA_READ_REQUEST)) {
139                         /*
140                          * If a RDMA read response is being resent and
141                          * we haven't seen the duplicate request yet,
142                          * then stop sending the remaining responses the
143                          * responder has seen until the requester re-sends it.
144                          */
145                         len = e->rdma_sge.sge_length;
146                         if (len && !e->rdma_sge.mr) {
147                                 qp->s_tail_ack_queue = qp->r_head_ack_queue;
148                                 goto bail;
149                         }
150                         /* Copy SGE state in case we need to resend */
151                         ps->s_txreq->mr = e->rdma_sge.mr;
152                         if (ps->s_txreq->mr)
153                                 rvt_get_mr(ps->s_txreq->mr);
154                         qp->s_ack_rdma_sge.sge = e->rdma_sge;
155                         qp->s_ack_rdma_sge.num_sge = 1;
156                         ps->s_txreq->ss = &qp->s_ack_rdma_sge;
157                         if (len > pmtu) {
158                                 len = pmtu;
159                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
160                         } else {
161                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
162                                 e->sent = 1;
163                         }
164                         ohdr->u.aeth = rvt_compute_aeth(qp);
165                         hwords++;
166                         qp->s_ack_rdma_psn = e->psn;
167                         bth2 = mask_psn(qp->s_ack_rdma_psn++);
168                 } else {
169                         /* COMPARE_SWAP or FETCH_ADD */
170                         ps->s_txreq->ss = NULL;
171                         len = 0;
172                         qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
173                         ohdr->u.at.aeth = rvt_compute_aeth(qp);
174                         ib_u64_put(e->atomic_data, &ohdr->u.at.atomic_ack_eth);
175                         hwords += sizeof(ohdr->u.at) / sizeof(u32);
176                         bth2 = mask_psn(e->psn);
177                         e->sent = 1;
178                 }
179                 bth0 = qp->s_ack_state << 24;
180                 break;
181
182         case OP(RDMA_READ_RESPONSE_FIRST):
183                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
184                 /* FALLTHROUGH */
185         case OP(RDMA_READ_RESPONSE_MIDDLE):
186                 ps->s_txreq->ss = &qp->s_ack_rdma_sge;
187                 ps->s_txreq->mr = qp->s_ack_rdma_sge.sge.mr;
188                 if (ps->s_txreq->mr)
189                         rvt_get_mr(ps->s_txreq->mr);
190                 len = qp->s_ack_rdma_sge.sge.sge_length;
191                 if (len > pmtu) {
192                         len = pmtu;
193                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
194                 } else {
195                         ohdr->u.aeth = rvt_compute_aeth(qp);
196                         hwords++;
197                         qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
198                         e = &qp->s_ack_queue[qp->s_tail_ack_queue];
199                         e->sent = 1;
200                 }
201                 bth0 = qp->s_ack_state << 24;
202                 bth2 = mask_psn(qp->s_ack_rdma_psn++);
203                 break;
204
205         default:
206 normal:
207                 /*
208                  * Send a regular ACK.
209                  * Set the s_ack_state so we wait until after sending
210                  * the ACK before setting s_ack_state to ACKNOWLEDGE
211                  * (see above).
212                  */
213                 qp->s_ack_state = OP(SEND_ONLY);
214                 qp->s_flags &= ~RVT_S_ACK_PENDING;
215                 ps->s_txreq->ss = NULL;
216                 if (qp->s_nak_state)
217                         ohdr->u.aeth =
218                                 cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
219                                             (qp->s_nak_state <<
220                                              IB_AETH_CREDIT_SHIFT));
221                 else
222                         ohdr->u.aeth = rvt_compute_aeth(qp);
223                 hwords++;
224                 len = 0;
225                 bth0 = OP(ACKNOWLEDGE) << 24;
226                 bth2 = mask_psn(qp->s_ack_psn);
227         }
228         qp->s_rdma_ack_cnt++;
229         ps->s_txreq->sde = priv->s_sde;
230         ps->s_txreq->s_cur_size = len;
231         ps->s_txreq->hdr_dwords = hwords;
232         hfi1_make_ruc_header(qp, ohdr, bth0, bth2, middle, ps);
233         return 1;
234
235 bail:
236         qp->s_ack_state = OP(ACKNOWLEDGE);
237         /*
238          * Ensure s_rdma_ack_cnt changes are committed prior to resetting
239          * RVT_S_RESP_PENDING
240          */
241         smp_wmb();
242         qp->s_flags &= ~(RVT_S_RESP_PENDING
243                                 | RVT_S_ACK_PENDING
244                                 | RVT_S_AHG_VALID);
245         return 0;
246 }
247
248 /**
249  * hfi1_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
250  * @qp: a pointer to the QP
251  *
252  * Assumes s_lock is held.
253  *
254  * Return 1 if constructed; otherwise, return 0.
255  */
256 int hfi1_make_rc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
257 {
258         struct hfi1_qp_priv *priv = qp->priv;
259         struct hfi1_ibdev *dev = to_idev(qp->ibqp.device);
260         struct ib_other_headers *ohdr;
261         struct rvt_sge_state *ss;
262         struct rvt_swqe *wqe;
263         u32 hwords;
264         u32 len;
265         u32 bth0 = 0;
266         u32 bth2;
267         u32 pmtu = qp->pmtu;
268         char newreq;
269         int middle = 0;
270         int delta;
271
272         lockdep_assert_held(&qp->s_lock);
273         ps->s_txreq = get_txreq(ps->dev, qp);
274         if (IS_ERR(ps->s_txreq))
275                 goto bail_no_tx;
276
277         if (priv->hdr_type == HFI1_PKT_TYPE_9B) {
278                 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
279                 hwords = 5;
280                 if (rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)
281                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.l.oth;
282                 else
283                         ohdr = &ps->s_txreq->phdr.hdr.ibh.u.oth;
284         } else {
285                 /* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
286                 hwords = 7;
287                 if ((rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
288                     (hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))))
289                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.l.oth;
290                 else
291                         ohdr = &ps->s_txreq->phdr.hdr.opah.u.oth;
292         }
293
294         /* Sending responses has higher priority over sending requests. */
295         if ((qp->s_flags & RVT_S_RESP_PENDING) &&
296             make_rc_ack(dev, qp, ohdr, ps))
297                 return 1;
298
299         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
300                 if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
301                         goto bail;
302                 /* We are in the error state, flush the work request. */
303                 if (qp->s_last == READ_ONCE(qp->s_head))
304                         goto bail;
305                 /* If DMAs are in progress, we can't flush immediately. */
306                 if (iowait_sdma_pending(&priv->s_iowait)) {
307                         qp->s_flags |= RVT_S_WAIT_DMA;
308                         goto bail;
309                 }
310                 clear_ahg(qp);
311                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
312                 hfi1_send_complete(qp, wqe, qp->s_last != qp->s_acked ?
313                         IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR);
314                 /* will get called again */
315                 goto done_free_tx;
316         }
317
318         if (qp->s_flags & (RVT_S_WAIT_RNR | RVT_S_WAIT_ACK))
319                 goto bail;
320
321         if (cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) {
322                 if (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) {
323                         qp->s_flags |= RVT_S_WAIT_PSN;
324                         goto bail;
325                 }
326                 qp->s_sending_psn = qp->s_psn;
327                 qp->s_sending_hpsn = qp->s_psn - 1;
328         }
329
330         /* Send a request. */
331         wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
332         switch (qp->s_state) {
333         default:
334                 if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK))
335                         goto bail;
336                 /*
337                  * Resend an old request or start a new one.
338                  *
339                  * We keep track of the current SWQE so that
340                  * we don't reset the "furthest progress" state
341                  * if we need to back up.
342                  */
343                 newreq = 0;
344                 if (qp->s_cur == qp->s_tail) {
345                         /* Check if send work queue is empty. */
346                         if (qp->s_tail == READ_ONCE(qp->s_head)) {
347                                 clear_ahg(qp);
348                                 goto bail;
349                         }
350                         /*
351                          * If a fence is requested, wait for previous
352                          * RDMA read and atomic operations to finish.
353                          */
354                         if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
355                             qp->s_num_rd_atomic) {
356                                 qp->s_flags |= RVT_S_WAIT_FENCE;
357                                 goto bail;
358                         }
359                         /*
360                          * Local operations are processed immediately
361                          * after all prior requests have completed
362                          */
363                         if (wqe->wr.opcode == IB_WR_REG_MR ||
364                             wqe->wr.opcode == IB_WR_LOCAL_INV) {
365                                 int local_ops = 0;
366                                 int err = 0;
367
368                                 if (qp->s_last != qp->s_cur)
369                                         goto bail;
370                                 if (++qp->s_cur == qp->s_size)
371                                         qp->s_cur = 0;
372                                 if (++qp->s_tail == qp->s_size)
373                                         qp->s_tail = 0;
374                                 if (!(wqe->wr.send_flags &
375                                       RVT_SEND_COMPLETION_ONLY)) {
376                                         err = rvt_invalidate_rkey(
377                                                 qp,
378                                                 wqe->wr.ex.invalidate_rkey);
379                                         local_ops = 1;
380                                 }
381                                 hfi1_send_complete(qp, wqe,
382                                                    err ? IB_WC_LOC_PROT_ERR
383                                                        : IB_WC_SUCCESS);
384                                 if (local_ops)
385                                         atomic_dec(&qp->local_ops_pending);
386                                 goto done_free_tx;
387                         }
388
389                         newreq = 1;
390                         qp->s_psn = wqe->psn;
391                 }
392                 /*
393                  * Note that we have to be careful not to modify the
394                  * original work request since we may need to resend
395                  * it.
396                  */
397                 len = wqe->length;
398                 ss = &qp->s_sge;
399                 bth2 = mask_psn(qp->s_psn);
400                 switch (wqe->wr.opcode) {
401                 case IB_WR_SEND:
402                 case IB_WR_SEND_WITH_IMM:
403                 case IB_WR_SEND_WITH_INV:
404                         /* If no credit, return. */
405                         if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
406                             rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
407                                 qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
408                                 goto bail;
409                         }
410                         if (len > pmtu) {
411                                 qp->s_state = OP(SEND_FIRST);
412                                 len = pmtu;
413                                 break;
414                         }
415                         if (wqe->wr.opcode == IB_WR_SEND) {
416                                 qp->s_state = OP(SEND_ONLY);
417                         } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
418                                 qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
419                                 /* Immediate data comes after the BTH */
420                                 ohdr->u.imm_data = wqe->wr.ex.imm_data;
421                                 hwords += 1;
422                         } else {
423                                 qp->s_state = OP(SEND_ONLY_WITH_INVALIDATE);
424                                 /* Invalidate rkey comes after the BTH */
425                                 ohdr->u.ieth = cpu_to_be32(
426                                                 wqe->wr.ex.invalidate_rkey);
427                                 hwords += 1;
428                         }
429                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
430                                 bth0 |= IB_BTH_SOLICITED;
431                         bth2 |= IB_BTH_REQ_ACK;
432                         if (++qp->s_cur == qp->s_size)
433                                 qp->s_cur = 0;
434                         break;
435
436                 case IB_WR_RDMA_WRITE:
437                         if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
438                                 qp->s_lsn++;
439                         goto no_flow_control;
440                 case IB_WR_RDMA_WRITE_WITH_IMM:
441                         /* If no credit, return. */
442                         if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
443                             rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
444                                 qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
445                                 goto bail;
446                         }
447 no_flow_control:
448                         put_ib_reth_vaddr(
449                                 wqe->rdma_wr.remote_addr,
450                                 &ohdr->u.rc.reth);
451                         ohdr->u.rc.reth.rkey =
452                                 cpu_to_be32(wqe->rdma_wr.rkey);
453                         ohdr->u.rc.reth.length = cpu_to_be32(len);
454                         hwords += sizeof(struct ib_reth) / sizeof(u32);
455                         if (len > pmtu) {
456                                 qp->s_state = OP(RDMA_WRITE_FIRST);
457                                 len = pmtu;
458                                 break;
459                         }
460                         if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
461                                 qp->s_state = OP(RDMA_WRITE_ONLY);
462                         } else {
463                                 qp->s_state =
464                                         OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
465                                 /* Immediate data comes after RETH */
466                                 ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
467                                 hwords += 1;
468                                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
469                                         bth0 |= IB_BTH_SOLICITED;
470                         }
471                         bth2 |= IB_BTH_REQ_ACK;
472                         if (++qp->s_cur == qp->s_size)
473                                 qp->s_cur = 0;
474                         break;
475
476                 case IB_WR_RDMA_READ:
477                         /*
478                          * Don't allow more operations to be started
479                          * than the QP limits allow.
480                          */
481                         if (newreq) {
482                                 if (qp->s_num_rd_atomic >=
483                                     qp->s_max_rd_atomic) {
484                                         qp->s_flags |= RVT_S_WAIT_RDMAR;
485                                         goto bail;
486                                 }
487                                 qp->s_num_rd_atomic++;
488                                 if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
489                                         qp->s_lsn++;
490                         }
491                         put_ib_reth_vaddr(
492                                 wqe->rdma_wr.remote_addr,
493                                 &ohdr->u.rc.reth);
494                         ohdr->u.rc.reth.rkey =
495                                 cpu_to_be32(wqe->rdma_wr.rkey);
496                         ohdr->u.rc.reth.length = cpu_to_be32(len);
497                         qp->s_state = OP(RDMA_READ_REQUEST);
498                         hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
499                         ss = NULL;
500                         len = 0;
501                         bth2 |= IB_BTH_REQ_ACK;
502                         if (++qp->s_cur == qp->s_size)
503                                 qp->s_cur = 0;
504                         break;
505
506                 case IB_WR_ATOMIC_CMP_AND_SWP:
507                 case IB_WR_ATOMIC_FETCH_AND_ADD:
508                         /*
509                          * Don't allow more operations to be started
510                          * than the QP limits allow.
511                          */
512                         if (newreq) {
513                                 if (qp->s_num_rd_atomic >=
514                                     qp->s_max_rd_atomic) {
515                                         qp->s_flags |= RVT_S_WAIT_RDMAR;
516                                         goto bail;
517                                 }
518                                 qp->s_num_rd_atomic++;
519                                 if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
520                                         qp->s_lsn++;
521                         }
522                         if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP) {
523                                 qp->s_state = OP(COMPARE_SWAP);
524                                 put_ib_ateth_swap(wqe->atomic_wr.swap,
525                                                   &ohdr->u.atomic_eth);
526                                 put_ib_ateth_compare(wqe->atomic_wr.compare_add,
527                                                      &ohdr->u.atomic_eth);
528                         } else {
529                                 qp->s_state = OP(FETCH_ADD);
530                                 put_ib_ateth_swap(wqe->atomic_wr.compare_add,
531                                                   &ohdr->u.atomic_eth);
532                                 put_ib_ateth_compare(0, &ohdr->u.atomic_eth);
533                         }
534                         put_ib_ateth_vaddr(wqe->atomic_wr.remote_addr,
535                                            &ohdr->u.atomic_eth);
536                         ohdr->u.atomic_eth.rkey = cpu_to_be32(
537                                 wqe->atomic_wr.rkey);
538                         hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
539                         ss = NULL;
540                         len = 0;
541                         bth2 |= IB_BTH_REQ_ACK;
542                         if (++qp->s_cur == qp->s_size)
543                                 qp->s_cur = 0;
544                         break;
545
546                 default:
547                         goto bail;
548                 }
549                 qp->s_sge.sge = wqe->sg_list[0];
550                 qp->s_sge.sg_list = wqe->sg_list + 1;
551                 qp->s_sge.num_sge = wqe->wr.num_sge;
552                 qp->s_sge.total_len = wqe->length;
553                 qp->s_len = wqe->length;
554                 if (newreq) {
555                         qp->s_tail++;
556                         if (qp->s_tail >= qp->s_size)
557                                 qp->s_tail = 0;
558                 }
559                 if (wqe->wr.opcode == IB_WR_RDMA_READ)
560                         qp->s_psn = wqe->lpsn + 1;
561                 else
562                         qp->s_psn++;
563                 break;
564
565         case OP(RDMA_READ_RESPONSE_FIRST):
566                 /*
567                  * qp->s_state is normally set to the opcode of the
568                  * last packet constructed for new requests and therefore
569                  * is never set to RDMA read response.
570                  * RDMA_READ_RESPONSE_FIRST is used by the ACK processing
571                  * thread to indicate a SEND needs to be restarted from an
572                  * earlier PSN without interfering with the sending thread.
573                  * See restart_rc().
574                  */
575                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
576                 /* FALLTHROUGH */
577         case OP(SEND_FIRST):
578                 qp->s_state = OP(SEND_MIDDLE);
579                 /* FALLTHROUGH */
580         case OP(SEND_MIDDLE):
581                 bth2 = mask_psn(qp->s_psn++);
582                 ss = &qp->s_sge;
583                 len = qp->s_len;
584                 if (len > pmtu) {
585                         len = pmtu;
586                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
587                         break;
588                 }
589                 if (wqe->wr.opcode == IB_WR_SEND) {
590                         qp->s_state = OP(SEND_LAST);
591                 } else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
592                         qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
593                         /* Immediate data comes after the BTH */
594                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
595                         hwords += 1;
596                 } else {
597                         qp->s_state = OP(SEND_LAST_WITH_INVALIDATE);
598                         /* invalidate data comes after the BTH */
599                         ohdr->u.ieth = cpu_to_be32(wqe->wr.ex.invalidate_rkey);
600                         hwords += 1;
601                 }
602                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
603                         bth0 |= IB_BTH_SOLICITED;
604                 bth2 |= IB_BTH_REQ_ACK;
605                 qp->s_cur++;
606                 if (qp->s_cur >= qp->s_size)
607                         qp->s_cur = 0;
608                 break;
609
610         case OP(RDMA_READ_RESPONSE_LAST):
611                 /*
612                  * qp->s_state is normally set to the opcode of the
613                  * last packet constructed for new requests and therefore
614                  * is never set to RDMA read response.
615                  * RDMA_READ_RESPONSE_LAST is used by the ACK processing
616                  * thread to indicate a RDMA write needs to be restarted from
617                  * an earlier PSN without interfering with the sending thread.
618                  * See restart_rc().
619                  */
620                 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
621                 /* FALLTHROUGH */
622         case OP(RDMA_WRITE_FIRST):
623                 qp->s_state = OP(RDMA_WRITE_MIDDLE);
624                 /* FALLTHROUGH */
625         case OP(RDMA_WRITE_MIDDLE):
626                 bth2 = mask_psn(qp->s_psn++);
627                 ss = &qp->s_sge;
628                 len = qp->s_len;
629                 if (len > pmtu) {
630                         len = pmtu;
631                         middle = HFI1_CAP_IS_KSET(SDMA_AHG);
632                         break;
633                 }
634                 if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
635                         qp->s_state = OP(RDMA_WRITE_LAST);
636                 } else {
637                         qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
638                         /* Immediate data comes after the BTH */
639                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
640                         hwords += 1;
641                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
642                                 bth0 |= IB_BTH_SOLICITED;
643                 }
644                 bth2 |= IB_BTH_REQ_ACK;
645                 qp->s_cur++;
646                 if (qp->s_cur >= qp->s_size)
647                         qp->s_cur = 0;
648                 break;
649
650         case OP(RDMA_READ_RESPONSE_MIDDLE):
651                 /*
652                  * qp->s_state is normally set to the opcode of the
653                  * last packet constructed for new requests and therefore
654                  * is never set to RDMA read response.
655                  * RDMA_READ_RESPONSE_MIDDLE is used by the ACK processing
656                  * thread to indicate a RDMA read needs to be restarted from
657                  * an earlier PSN without interfering with the sending thread.
658                  * See restart_rc().
659                  */
660                 len = (delta_psn(qp->s_psn, wqe->psn)) * pmtu;
661                 put_ib_reth_vaddr(
662                         wqe->rdma_wr.remote_addr + len,
663                         &ohdr->u.rc.reth);
664                 ohdr->u.rc.reth.rkey =
665                         cpu_to_be32(wqe->rdma_wr.rkey);
666                 ohdr->u.rc.reth.length = cpu_to_be32(wqe->length - len);
667                 qp->s_state = OP(RDMA_READ_REQUEST);
668                 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
669                 bth2 = mask_psn(qp->s_psn) | IB_BTH_REQ_ACK;
670                 qp->s_psn = wqe->lpsn + 1;
671                 ss = NULL;
672                 len = 0;
673                 qp->s_cur++;
674                 if (qp->s_cur == qp->s_size)
675                         qp->s_cur = 0;
676                 break;
677         }
678         qp->s_sending_hpsn = bth2;
679         delta = delta_psn(bth2, wqe->psn);
680         if (delta && delta % HFI1_PSN_CREDIT == 0)
681                 bth2 |= IB_BTH_REQ_ACK;
682         if (qp->s_flags & RVT_S_SEND_ONE) {
683                 qp->s_flags &= ~RVT_S_SEND_ONE;
684                 qp->s_flags |= RVT_S_WAIT_ACK;
685                 bth2 |= IB_BTH_REQ_ACK;
686         }
687         qp->s_len -= len;
688         ps->s_txreq->hdr_dwords = hwords;
689         ps->s_txreq->sde = priv->s_sde;
690         ps->s_txreq->ss = ss;
691         ps->s_txreq->s_cur_size = len;
692         hfi1_make_ruc_header(
693                 qp,
694                 ohdr,
695                 bth0 | (qp->s_state << 24),
696                 bth2,
697                 middle,
698                 ps);
699         return 1;
700
701 done_free_tx:
702         hfi1_put_txreq(ps->s_txreq);
703         ps->s_txreq = NULL;
704         return 1;
705
706 bail:
707         hfi1_put_txreq(ps->s_txreq);
708
709 bail_no_tx:
710         ps->s_txreq = NULL;
711         qp->s_flags &= ~RVT_S_BUSY;
712         return 0;
713 }
714
715 static inline void hfi1_make_bth_aeth(struct rvt_qp *qp,
716                                       struct ib_other_headers *ohdr,
717                                       u32 bth0, u32 bth1)
718 {
719         if (qp->r_nak_state)
720                 ohdr->u.aeth = cpu_to_be32((qp->r_msn & IB_MSN_MASK) |
721                                             (qp->r_nak_state <<
722                                              IB_AETH_CREDIT_SHIFT));
723         else
724                 ohdr->u.aeth = rvt_compute_aeth(qp);
725
726         ohdr->bth[0] = cpu_to_be32(bth0);
727         ohdr->bth[1] = cpu_to_be32(bth1 | qp->remote_qpn);
728         ohdr->bth[2] = cpu_to_be32(mask_psn(qp->r_ack_psn));
729 }
730
731 static inline void hfi1_queue_rc_ack(struct hfi1_packet *packet, bool is_fecn)
732 {
733         struct rvt_qp *qp = packet->qp;
734         struct hfi1_ibport *ibp;
735         unsigned long flags;
736
737         spin_lock_irqsave(&qp->s_lock, flags);
738         if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
739                 goto unlock;
740         ibp = rcd_to_iport(packet->rcd);
741         this_cpu_inc(*ibp->rvp.rc_qacks);
742         qp->s_flags |= RVT_S_ACK_PENDING | RVT_S_RESP_PENDING;
743         qp->s_nak_state = qp->r_nak_state;
744         qp->s_ack_psn = qp->r_ack_psn;
745         if (is_fecn)
746                 qp->s_flags |= RVT_S_ECN;
747
748         /* Schedule the send tasklet. */
749         hfi1_schedule_send(qp);
750 unlock:
751         spin_unlock_irqrestore(&qp->s_lock, flags);
752 }
753
754 static inline void hfi1_make_rc_ack_9B(struct hfi1_packet *packet,
755                                        struct hfi1_opa_header *opa_hdr,
756                                        u8 sc5, bool is_fecn,
757                                        u64 *pbc_flags, u32 *hwords,
758                                        u32 *nwords)
759 {
760         struct rvt_qp *qp = packet->qp;
761         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
762         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
763         struct ib_header *hdr = &opa_hdr->ibh;
764         struct ib_other_headers *ohdr;
765         u16 lrh0 = HFI1_LRH_BTH;
766         u16 pkey;
767         u32 bth0, bth1;
768
769         opa_hdr->hdr_type = HFI1_PKT_TYPE_9B;
770         ohdr = &hdr->u.oth;
771         /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4 */
772         *hwords = 6;
773
774         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)) {
775                 *hwords += hfi1_make_grh(ibp, &hdr->u.l.grh,
776                                          rdma_ah_read_grh(&qp->remote_ah_attr),
777                                          *hwords - 2, SIZE_OF_CRC);
778                 ohdr = &hdr->u.l.oth;
779                 lrh0 = HFI1_LRH_GRH;
780         }
781         /* set PBC_DC_INFO bit (aka SC[4]) in pbc_flags */
782         *pbc_flags |= ((!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT);
783
784         /* read pkey_index w/o lock (its atomic) */
785         pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
786
787         lrh0 |= (sc5 & IB_SC_MASK) << IB_SC_SHIFT |
788                 (rdma_ah_get_sl(&qp->remote_ah_attr) & IB_SL_MASK) <<
789                         IB_SL_SHIFT;
790
791         hfi1_make_ib_hdr(hdr, lrh0, *hwords + SIZE_OF_CRC,
792                          opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr), 9B),
793                          ppd->lid | rdma_ah_get_path_bits(&qp->remote_ah_attr));
794
795         bth0 = pkey | (OP(ACKNOWLEDGE) << 24);
796         if (qp->s_mig_state == IB_MIG_MIGRATED)
797                 bth0 |= IB_BTH_MIG_REQ;
798         bth1 = (!!is_fecn) << IB_BECN_SHIFT;
799         hfi1_make_bth_aeth(qp, ohdr, bth0, bth1);
800 }
801
802 static inline void hfi1_make_rc_ack_16B(struct hfi1_packet *packet,
803                                         struct hfi1_opa_header *opa_hdr,
804                                         u8 sc5, bool is_fecn,
805                                         u64 *pbc_flags, u32 *hwords,
806                                         u32 *nwords)
807 {
808         struct rvt_qp *qp = packet->qp;
809         struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
810         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
811         struct hfi1_16b_header *hdr = &opa_hdr->opah;
812         struct ib_other_headers *ohdr;
813         u32 bth0, bth1 = 0;
814         u16 len, pkey;
815         bool becn = is_fecn;
816         u8 l4 = OPA_16B_L4_IB_LOCAL;
817         u8 extra_bytes;
818
819         opa_hdr->hdr_type = HFI1_PKT_TYPE_16B;
820         ohdr = &hdr->u.oth;
821         /* header size in 32-bit words 16B LRH+BTH+AETH = (16+12+4)/4 */
822         *hwords = 8;
823         extra_bytes = hfi1_get_16b_padding(*hwords << 2, 0);
824         *nwords = SIZE_OF_CRC + ((extra_bytes + SIZE_OF_LT) >> 2);
825
826         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
827             hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))) {
828                 *hwords += hfi1_make_grh(ibp, &hdr->u.l.grh,
829                                          rdma_ah_read_grh(&qp->remote_ah_attr),
830                                          *hwords - 4, *nwords);
831                 ohdr = &hdr->u.l.oth;
832                 l4 = OPA_16B_L4_IB_GLOBAL;
833         }
834         *pbc_flags |= PBC_PACKET_BYPASS | PBC_INSERT_BYPASS_ICRC;
835
836         /* read pkey_index w/o lock (its atomic) */
837         pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
838
839         /* Convert dwords to flits */
840         len = (*hwords + *nwords) >> 1;
841
842         hfi1_make_16b_hdr(hdr, ppd->lid |
843                           (rdma_ah_get_path_bits(&qp->remote_ah_attr) &
844                           ((1 << ppd->lmc) - 1)),
845                           opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr),
846                                       16B), len, pkey, becn, 0, l4, sc5);
847
848         bth0 = pkey | (OP(ACKNOWLEDGE) << 24);
849         bth0 |= extra_bytes << 20;
850         if (qp->s_mig_state == IB_MIG_MIGRATED)
851                 bth1 = OPA_BTH_MIG_REQ;
852         hfi1_make_bth_aeth(qp, ohdr, bth0, bth1);
853 }
854
855 typedef void (*hfi1_make_rc_ack)(struct hfi1_packet *packet,
856                                  struct hfi1_opa_header *opa_hdr,
857                                  u8 sc5, bool is_fecn,
858                                  u64 *pbc_flags, u32 *hwords,
859                                  u32 *nwords);
860
861 /* We support only two types - 9B and 16B for now */
862 static const hfi1_make_rc_ack hfi1_make_rc_ack_tbl[2] = {
863         [HFI1_PKT_TYPE_9B] = &hfi1_make_rc_ack_9B,
864         [HFI1_PKT_TYPE_16B] = &hfi1_make_rc_ack_16B
865 };
866
867 /**
868  * hfi1_send_rc_ack - Construct an ACK packet and send it
869  * @qp: a pointer to the QP
870  *
871  * This is called from hfi1_rc_rcv() and handle_receive_interrupt().
872  * Note that RDMA reads and atomics are handled in the
873  * send side QP state and send engine.
874  */
875 void hfi1_send_rc_ack(struct hfi1_packet *packet, bool is_fecn)
876 {
877         struct hfi1_ctxtdata *rcd = packet->rcd;
878         struct rvt_qp *qp = packet->qp;
879         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
880         struct hfi1_qp_priv *priv = qp->priv;
881         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
882         u8 sc5 = ibp->sl_to_sc[rdma_ah_get_sl(&qp->remote_ah_attr)];
883         u64 pbc, pbc_flags = 0;
884         u32 hwords = 0;
885         u32 nwords = 0;
886         u32 plen;
887         struct pio_buf *pbuf;
888         struct hfi1_opa_header opa_hdr;
889
890         /* clear the defer count */
891         qp->r_adefered = 0;
892
893         /* Don't send ACK or NAK if a RDMA read or atomic is pending. */
894         if (qp->s_flags & RVT_S_RESP_PENDING) {
895                 hfi1_queue_rc_ack(packet, is_fecn);
896                 return;
897         }
898
899         /* Ensure s_rdma_ack_cnt changes are committed */
900         if (qp->s_rdma_ack_cnt) {
901                 hfi1_queue_rc_ack(packet, is_fecn);
902                 return;
903         }
904
905         /* Don't try to send ACKs if the link isn't ACTIVE */
906         if (driver_lstate(ppd) != IB_PORT_ACTIVE)
907                 return;
908
909         /* Make the appropriate header */
910         hfi1_make_rc_ack_tbl[priv->hdr_type](packet, &opa_hdr, sc5, is_fecn,
911                                              &pbc_flags, &hwords, &nwords);
912
913         plen = 2 /* PBC */ + hwords + nwords;
914         pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps,
915                          sc_to_vlt(ppd->dd, sc5), plen);
916         pbuf = sc_buffer_alloc(rcd->sc, plen, NULL, NULL);
917         if (!pbuf) {
918                 /*
919                  * We have no room to send at the moment.  Pass
920                  * responsibility for sending the ACK to the send engine
921                  * so that when enough buffer space becomes available,
922                  * the ACK is sent ahead of other outgoing packets.
923                  */
924                 hfi1_queue_rc_ack(packet, is_fecn);
925                 return;
926         }
927         trace_ack_output_ibhdr(dd_from_ibdev(qp->ibqp.device),
928                                &opa_hdr, ib_is_sc5(sc5));
929
930         /* write the pbc and data */
931         ppd->dd->pio_inline_send(ppd->dd, pbuf, pbc,
932                                  (priv->hdr_type == HFI1_PKT_TYPE_9B ?
933                                  (void *)&opa_hdr.ibh :
934                                  (void *)&opa_hdr.opah), hwords);
935         return;
936 }
937
938 /**
939  * reset_psn - reset the QP state to send starting from PSN
940  * @qp: the QP
941  * @psn: the packet sequence number to restart at
942  *
943  * This is called from hfi1_rc_rcv() to process an incoming RC ACK
944  * for the given QP.
945  * Called at interrupt level with the QP s_lock held.
946  */
947 static void reset_psn(struct rvt_qp *qp, u32 psn)
948 {
949         u32 n = qp->s_acked;
950         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, n);
951         u32 opcode;
952
953         lockdep_assert_held(&qp->s_lock);
954         qp->s_cur = n;
955
956         /*
957          * If we are starting the request from the beginning,
958          * let the normal send code handle initialization.
959          */
960         if (cmp_psn(psn, wqe->psn) <= 0) {
961                 qp->s_state = OP(SEND_LAST);
962                 goto done;
963         }
964
965         /* Find the work request opcode corresponding to the given PSN. */
966         opcode = wqe->wr.opcode;
967         for (;;) {
968                 int diff;
969
970                 if (++n == qp->s_size)
971                         n = 0;
972                 if (n == qp->s_tail)
973                         break;
974                 wqe = rvt_get_swqe_ptr(qp, n);
975                 diff = cmp_psn(psn, wqe->psn);
976                 if (diff < 0)
977                         break;
978                 qp->s_cur = n;
979                 /*
980                  * If we are starting the request from the beginning,
981                  * let the normal send code handle initialization.
982                  */
983                 if (diff == 0) {
984                         qp->s_state = OP(SEND_LAST);
985                         goto done;
986                 }
987                 opcode = wqe->wr.opcode;
988         }
989
990         /*
991          * Set the state to restart in the middle of a request.
992          * Don't change the s_sge, s_cur_sge, or s_cur_size.
993          * See hfi1_make_rc_req().
994          */
995         switch (opcode) {
996         case IB_WR_SEND:
997         case IB_WR_SEND_WITH_IMM:
998                 qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
999                 break;
1000
1001         case IB_WR_RDMA_WRITE:
1002         case IB_WR_RDMA_WRITE_WITH_IMM:
1003                 qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
1004                 break;
1005
1006         case IB_WR_RDMA_READ:
1007                 qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
1008                 break;
1009
1010         default:
1011                 /*
1012                  * This case shouldn't happen since its only
1013                  * one PSN per req.
1014                  */
1015                 qp->s_state = OP(SEND_LAST);
1016         }
1017 done:
1018         qp->s_psn = psn;
1019         /*
1020          * Set RVT_S_WAIT_PSN as rc_complete() may start the timer
1021          * asynchronously before the send engine can get scheduled.
1022          * Doing it in hfi1_make_rc_req() is too late.
1023          */
1024         if ((cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) &&
1025             (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0))
1026                 qp->s_flags |= RVT_S_WAIT_PSN;
1027         qp->s_flags &= ~RVT_S_AHG_VALID;
1028 }
1029
1030 /*
1031  * Back up requester to resend the last un-ACKed request.
1032  * The QP r_lock and s_lock should be held and interrupts disabled.
1033  */
1034 void hfi1_restart_rc(struct rvt_qp *qp, u32 psn, int wait)
1035 {
1036         struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1037         struct hfi1_ibport *ibp;
1038
1039         lockdep_assert_held(&qp->r_lock);
1040         lockdep_assert_held(&qp->s_lock);
1041         if (qp->s_retry == 0) {
1042                 if (qp->s_mig_state == IB_MIG_ARMED) {
1043                         hfi1_migrate_qp(qp);
1044                         qp->s_retry = qp->s_retry_cnt;
1045                 } else if (qp->s_last == qp->s_acked) {
1046                         hfi1_send_complete(qp, wqe, IB_WC_RETRY_EXC_ERR);
1047                         rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1048                         return;
1049                 } else { /* need to handle delayed completion */
1050                         return;
1051                 }
1052         } else {
1053                 qp->s_retry--;
1054         }
1055
1056         ibp = to_iport(qp->ibqp.device, qp->port_num);
1057         if (wqe->wr.opcode == IB_WR_RDMA_READ)
1058                 ibp->rvp.n_rc_resends++;
1059         else
1060                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
1061
1062         qp->s_flags &= ~(RVT_S_WAIT_FENCE | RVT_S_WAIT_RDMAR |
1063                          RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_PSN |
1064                          RVT_S_WAIT_ACK);
1065         if (wait)
1066                 qp->s_flags |= RVT_S_SEND_ONE;
1067         reset_psn(qp, psn);
1068 }
1069
1070 /*
1071  * Set qp->s_sending_psn to the next PSN after the given one.
1072  * This would be psn+1 except when RDMA reads are present.
1073  */
1074 static void reset_sending_psn(struct rvt_qp *qp, u32 psn)
1075 {
1076         struct rvt_swqe *wqe;
1077         u32 n = qp->s_last;
1078
1079         lockdep_assert_held(&qp->s_lock);
1080         /* Find the work request corresponding to the given PSN. */
1081         for (;;) {
1082                 wqe = rvt_get_swqe_ptr(qp, n);
1083                 if (cmp_psn(psn, wqe->lpsn) <= 0) {
1084                         if (wqe->wr.opcode == IB_WR_RDMA_READ)
1085                                 qp->s_sending_psn = wqe->lpsn + 1;
1086                         else
1087                                 qp->s_sending_psn = psn + 1;
1088                         break;
1089                 }
1090                 if (++n == qp->s_size)
1091                         n = 0;
1092                 if (n == qp->s_tail)
1093                         break;
1094         }
1095 }
1096
1097 /*
1098  * This should be called with the QP s_lock held and interrupts disabled.
1099  */
1100 void hfi1_rc_send_complete(struct rvt_qp *qp, struct hfi1_opa_header *opah)
1101 {
1102         struct ib_other_headers *ohdr;
1103         struct hfi1_qp_priv *priv = qp->priv;
1104         struct rvt_swqe *wqe;
1105         struct ib_header *hdr = NULL;
1106         struct hfi1_16b_header *hdr_16b = NULL;
1107         u32 opcode;
1108         u32 psn;
1109
1110         lockdep_assert_held(&qp->s_lock);
1111         if (!(ib_rvt_state_ops[qp->state] & RVT_SEND_OR_FLUSH_OR_RECV_OK))
1112                 return;
1113
1114         /* Find out where the BTH is */
1115         if (priv->hdr_type == HFI1_PKT_TYPE_9B) {
1116                 hdr = &opah->ibh;
1117                 if (ib_get_lnh(hdr) == HFI1_LRH_BTH)
1118                         ohdr = &hdr->u.oth;
1119                 else
1120                         ohdr = &hdr->u.l.oth;
1121         } else {
1122                 u8 l4;
1123
1124                 hdr_16b = &opah->opah;
1125                 l4  = hfi1_16B_get_l4(hdr_16b);
1126                 if (l4 == OPA_16B_L4_IB_LOCAL)
1127                         ohdr = &hdr_16b->u.oth;
1128                 else
1129                         ohdr = &hdr_16b->u.l.oth;
1130         }
1131
1132         opcode = ib_bth_get_opcode(ohdr);
1133         if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1134             opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
1135                 WARN_ON(!qp->s_rdma_ack_cnt);
1136                 qp->s_rdma_ack_cnt--;
1137                 return;
1138         }
1139
1140         psn = ib_bth_get_psn(ohdr);
1141         reset_sending_psn(qp, psn);
1142
1143         /*
1144          * Start timer after a packet requesting an ACK has been sent and
1145          * there are still requests that haven't been acked.
1146          */
1147         if ((psn & IB_BTH_REQ_ACK) && qp->s_acked != qp->s_tail &&
1148             !(qp->s_flags &
1149                 (RVT_S_TIMER | RVT_S_WAIT_RNR | RVT_S_WAIT_PSN)) &&
1150                 (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
1151                 rvt_add_retry_timer(qp);
1152
1153         while (qp->s_last != qp->s_acked) {
1154                 u32 s_last;
1155
1156                 wqe = rvt_get_swqe_ptr(qp, qp->s_last);
1157                 if (cmp_psn(wqe->lpsn, qp->s_sending_psn) >= 0 &&
1158                     cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)
1159                         break;
1160                 s_last = qp->s_last;
1161                 trace_hfi1_qp_send_completion(qp, wqe, s_last);
1162                 if (++s_last >= qp->s_size)
1163                         s_last = 0;
1164                 qp->s_last = s_last;
1165                 /* see post_send() */
1166                 barrier();
1167                 rvt_put_swqe(wqe);
1168                 rvt_qp_swqe_complete(qp,
1169                                      wqe,
1170                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1171                                      IB_WC_SUCCESS);
1172         }
1173         /*
1174          * If we were waiting for sends to complete before re-sending,
1175          * and they are now complete, restart sending.
1176          */
1177         trace_hfi1_sendcomplete(qp, psn);
1178         if (qp->s_flags & RVT_S_WAIT_PSN &&
1179             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1180                 qp->s_flags &= ~RVT_S_WAIT_PSN;
1181                 qp->s_sending_psn = qp->s_psn;
1182                 qp->s_sending_hpsn = qp->s_psn - 1;
1183                 hfi1_schedule_send(qp);
1184         }
1185 }
1186
1187 static inline void update_last_psn(struct rvt_qp *qp, u32 psn)
1188 {
1189         qp->s_last_psn = psn;
1190 }
1191
1192 /*
1193  * Generate a SWQE completion.
1194  * This is similar to hfi1_send_complete but has to check to be sure
1195  * that the SGEs are not being referenced if the SWQE is being resent.
1196  */
1197 static struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
1198                                          struct rvt_swqe *wqe,
1199                                          struct hfi1_ibport *ibp)
1200 {
1201         lockdep_assert_held(&qp->s_lock);
1202         /*
1203          * Don't decrement refcount and don't generate a
1204          * completion if the SWQE is being resent until the send
1205          * is finished.
1206          */
1207         if (cmp_psn(wqe->lpsn, qp->s_sending_psn) < 0 ||
1208             cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1209                 u32 s_last;
1210
1211                 rvt_put_swqe(wqe);
1212                 s_last = qp->s_last;
1213                 trace_hfi1_qp_send_completion(qp, wqe, s_last);
1214                 if (++s_last >= qp->s_size)
1215                         s_last = 0;
1216                 qp->s_last = s_last;
1217                 /* see post_send() */
1218                 barrier();
1219                 rvt_qp_swqe_complete(qp,
1220                                      wqe,
1221                                      ib_hfi1_wc_opcode[wqe->wr.opcode],
1222                                      IB_WC_SUCCESS);
1223         } else {
1224                 struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1225
1226                 this_cpu_inc(*ibp->rvp.rc_delayed_comp);
1227                 /*
1228                  * If send progress not running attempt to progress
1229                  * SDMA queue.
1230                  */
1231                 if (ppd->dd->flags & HFI1_HAS_SEND_DMA) {
1232                         struct sdma_engine *engine;
1233                         u8 sl = rdma_ah_get_sl(&qp->remote_ah_attr);
1234                         u8 sc5;
1235
1236                         /* For now use sc to find engine */
1237                         sc5 = ibp->sl_to_sc[sl];
1238                         engine = qp_to_sdma_engine(qp, sc5);
1239                         sdma_engine_progress_schedule(engine);
1240                 }
1241         }
1242
1243         qp->s_retry = qp->s_retry_cnt;
1244         update_last_psn(qp, wqe->lpsn);
1245
1246         /*
1247          * If we are completing a request which is in the process of
1248          * being resent, we can stop re-sending it since we know the
1249          * responder has already seen it.
1250          */
1251         if (qp->s_acked == qp->s_cur) {
1252                 if (++qp->s_cur >= qp->s_size)
1253                         qp->s_cur = 0;
1254                 qp->s_acked = qp->s_cur;
1255                 wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
1256                 if (qp->s_acked != qp->s_tail) {
1257                         qp->s_state = OP(SEND_LAST);
1258                         qp->s_psn = wqe->psn;
1259                 }
1260         } else {
1261                 if (++qp->s_acked >= qp->s_size)
1262                         qp->s_acked = 0;
1263                 if (qp->state == IB_QPS_SQD && qp->s_acked == qp->s_cur)
1264                         qp->s_draining = 0;
1265                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1266         }
1267         return wqe;
1268 }
1269
1270 /**
1271  * do_rc_ack - process an incoming RC ACK
1272  * @qp: the QP the ACK came in on
1273  * @psn: the packet sequence number of the ACK
1274  * @opcode: the opcode of the request that resulted in the ACK
1275  *
1276  * This is called from rc_rcv_resp() to process an incoming RC ACK
1277  * for the given QP.
1278  * May be called at interrupt level, with the QP s_lock held.
1279  * Returns 1 if OK, 0 if current operation should be aborted (NAK).
1280  */
1281 static int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode,
1282                      u64 val, struct hfi1_ctxtdata *rcd)
1283 {
1284         struct hfi1_ibport *ibp;
1285         enum ib_wc_status status;
1286         struct rvt_swqe *wqe;
1287         int ret = 0;
1288         u32 ack_psn;
1289         int diff;
1290
1291         lockdep_assert_held(&qp->s_lock);
1292         /*
1293          * Note that NAKs implicitly ACK outstanding SEND and RDMA write
1294          * requests and implicitly NAK RDMA read and atomic requests issued
1295          * before the NAK'ed request.  The MSN won't include the NAK'ed
1296          * request but will include an ACK'ed request(s).
1297          */
1298         ack_psn = psn;
1299         if (aeth >> IB_AETH_NAK_SHIFT)
1300                 ack_psn--;
1301         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1302         ibp = rcd_to_iport(rcd);
1303
1304         /*
1305          * The MSN might be for a later WQE than the PSN indicates so
1306          * only complete WQEs that the PSN finishes.
1307          */
1308         while ((diff = delta_psn(ack_psn, wqe->lpsn)) >= 0) {
1309                 /*
1310                  * RDMA_READ_RESPONSE_ONLY is a special case since
1311                  * we want to generate completion events for everything
1312                  * before the RDMA read, copy the data, then generate
1313                  * the completion for the read.
1314                  */
1315                 if (wqe->wr.opcode == IB_WR_RDMA_READ &&
1316                     opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
1317                     diff == 0) {
1318                         ret = 1;
1319                         goto bail_stop;
1320                 }
1321                 /*
1322                  * If this request is a RDMA read or atomic, and the ACK is
1323                  * for a later operation, this ACK NAKs the RDMA read or
1324                  * atomic.  In other words, only a RDMA_READ_LAST or ONLY
1325                  * can ACK a RDMA read and likewise for atomic ops.  Note
1326                  * that the NAK case can only happen if relaxed ordering is
1327                  * used and requests are sent after an RDMA read or atomic
1328                  * is sent but before the response is received.
1329                  */
1330                 if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
1331                      (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
1332                     ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1333                       wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
1334                      (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0))) {
1335                         /* Retry this request. */
1336                         if (!(qp->r_flags & RVT_R_RDMAR_SEQ)) {
1337                                 qp->r_flags |= RVT_R_RDMAR_SEQ;
1338                                 hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
1339                                 if (list_empty(&qp->rspwait)) {
1340                                         qp->r_flags |= RVT_R_RSP_SEND;
1341                                         rvt_get_qp(qp);
1342                                         list_add_tail(&qp->rspwait,
1343                                                       &rcd->qp_wait_list);
1344                                 }
1345                         }
1346                         /*
1347                          * No need to process the ACK/NAK since we are
1348                          * restarting an earlier request.
1349                          */
1350                         goto bail_stop;
1351                 }
1352                 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1353                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
1354                         u64 *vaddr = wqe->sg_list[0].vaddr;
1355                         *vaddr = val;
1356                 }
1357                 if (qp->s_num_rd_atomic &&
1358                     (wqe->wr.opcode == IB_WR_RDMA_READ ||
1359                      wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1360                      wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
1361                         qp->s_num_rd_atomic--;
1362                         /* Restart sending task if fence is complete */
1363                         if ((qp->s_flags & RVT_S_WAIT_FENCE) &&
1364                             !qp->s_num_rd_atomic) {
1365                                 qp->s_flags &= ~(RVT_S_WAIT_FENCE |
1366                                                  RVT_S_WAIT_ACK);
1367                                 hfi1_schedule_send(qp);
1368                         } else if (qp->s_flags & RVT_S_WAIT_RDMAR) {
1369                                 qp->s_flags &= ~(RVT_S_WAIT_RDMAR |
1370                                                  RVT_S_WAIT_ACK);
1371                                 hfi1_schedule_send(qp);
1372                         }
1373                 }
1374                 wqe = do_rc_completion(qp, wqe, ibp);
1375                 if (qp->s_acked == qp->s_tail)
1376                         break;
1377         }
1378
1379         switch (aeth >> IB_AETH_NAK_SHIFT) {
1380         case 0:         /* ACK */
1381                 this_cpu_inc(*ibp->rvp.rc_acks);
1382                 if (qp->s_acked != qp->s_tail) {
1383                         /*
1384                          * We are expecting more ACKs so
1385                          * mod the retry timer.
1386                          */
1387                         rvt_mod_retry_timer(qp);
1388                         /*
1389                          * We can stop re-sending the earlier packets and
1390                          * continue with the next packet the receiver wants.
1391                          */
1392                         if (cmp_psn(qp->s_psn, psn) <= 0)
1393                                 reset_psn(qp, psn + 1);
1394                 } else {
1395                         /* No more acks - kill all timers */
1396                         rvt_stop_rc_timers(qp);
1397                         if (cmp_psn(qp->s_psn, psn) <= 0) {
1398                                 qp->s_state = OP(SEND_LAST);
1399                                 qp->s_psn = psn + 1;
1400                         }
1401                 }
1402                 if (qp->s_flags & RVT_S_WAIT_ACK) {
1403                         qp->s_flags &= ~RVT_S_WAIT_ACK;
1404                         hfi1_schedule_send(qp);
1405                 }
1406                 rvt_get_credit(qp, aeth);
1407                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1408                 qp->s_retry = qp->s_retry_cnt;
1409                 update_last_psn(qp, psn);
1410                 return 1;
1411
1412         case 1:         /* RNR NAK */
1413                 ibp->rvp.n_rnr_naks++;
1414                 if (qp->s_acked == qp->s_tail)
1415                         goto bail_stop;
1416                 if (qp->s_flags & RVT_S_WAIT_RNR)
1417                         goto bail_stop;
1418                 if (qp->s_rnr_retry == 0) {
1419                         status = IB_WC_RNR_RETRY_EXC_ERR;
1420                         goto class_b;
1421                 }
1422                 if (qp->s_rnr_retry_cnt < 7)
1423                         qp->s_rnr_retry--;
1424
1425                 /* The last valid PSN is the previous PSN. */
1426                 update_last_psn(qp, psn - 1);
1427
1428                 ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
1429
1430                 reset_psn(qp, psn);
1431
1432                 qp->s_flags &= ~(RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_ACK);
1433                 rvt_stop_rc_timers(qp);
1434                 rvt_add_rnr_timer(qp, aeth);
1435                 return 0;
1436
1437         case 3:         /* NAK */
1438                 if (qp->s_acked == qp->s_tail)
1439                         goto bail_stop;
1440                 /* The last valid PSN is the previous PSN. */
1441                 update_last_psn(qp, psn - 1);
1442                 switch ((aeth >> IB_AETH_CREDIT_SHIFT) &
1443                         IB_AETH_CREDIT_MASK) {
1444                 case 0: /* PSN sequence error */
1445                         ibp->rvp.n_seq_naks++;
1446                         /*
1447                          * Back up to the responder's expected PSN.
1448                          * Note that we might get a NAK in the middle of an
1449                          * RDMA READ response which terminates the RDMA
1450                          * READ.
1451                          */
1452                         hfi1_restart_rc(qp, psn, 0);
1453                         hfi1_schedule_send(qp);
1454                         break;
1455
1456                 case 1: /* Invalid Request */
1457                         status = IB_WC_REM_INV_REQ_ERR;
1458                         ibp->rvp.n_other_naks++;
1459                         goto class_b;
1460
1461                 case 2: /* Remote Access Error */
1462                         status = IB_WC_REM_ACCESS_ERR;
1463                         ibp->rvp.n_other_naks++;
1464                         goto class_b;
1465
1466                 case 3: /* Remote Operation Error */
1467                         status = IB_WC_REM_OP_ERR;
1468                         ibp->rvp.n_other_naks++;
1469 class_b:
1470                         if (qp->s_last == qp->s_acked) {
1471                                 hfi1_send_complete(qp, wqe, status);
1472                                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1473                         }
1474                         break;
1475
1476                 default:
1477                         /* Ignore other reserved NAK error codes */
1478                         goto reserved;
1479                 }
1480                 qp->s_retry = qp->s_retry_cnt;
1481                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1482                 goto bail_stop;
1483
1484         default:                /* 2: reserved */
1485 reserved:
1486                 /* Ignore reserved NAK codes. */
1487                 goto bail_stop;
1488         }
1489         /* cannot be reached  */
1490 bail_stop:
1491         rvt_stop_rc_timers(qp);
1492         return ret;
1493 }
1494
1495 /*
1496  * We have seen an out of sequence RDMA read middle or last packet.
1497  * This ACKs SENDs and RDMA writes up to the first RDMA read or atomic SWQE.
1498  */
1499 static void rdma_seq_err(struct rvt_qp *qp, struct hfi1_ibport *ibp, u32 psn,
1500                          struct hfi1_ctxtdata *rcd)
1501 {
1502         struct rvt_swqe *wqe;
1503
1504         lockdep_assert_held(&qp->s_lock);
1505         /* Remove QP from retry timer */
1506         rvt_stop_rc_timers(qp);
1507
1508         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1509
1510         while (cmp_psn(psn, wqe->lpsn) > 0) {
1511                 if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1512                     wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1513                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
1514                         break;
1515                 wqe = do_rc_completion(qp, wqe, ibp);
1516         }
1517
1518         ibp->rvp.n_rdma_seq++;
1519         qp->r_flags |= RVT_R_RDMAR_SEQ;
1520         hfi1_restart_rc(qp, qp->s_last_psn + 1, 0);
1521         if (list_empty(&qp->rspwait)) {
1522                 qp->r_flags |= RVT_R_RSP_SEND;
1523                 rvt_get_qp(qp);
1524                 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1525         }
1526 }
1527
1528 /**
1529  * rc_rcv_resp - process an incoming RC response packet
1530  * @packet: data packet information
1531  *
1532  * This is called from hfi1_rc_rcv() to process an incoming RC response
1533  * packet for the given QP.
1534  * Called at interrupt level.
1535  */
1536 static void rc_rcv_resp(struct hfi1_packet *packet)
1537 {
1538         struct hfi1_ctxtdata *rcd = packet->rcd;
1539         void *data = packet->payload;
1540         u32 tlen = packet->tlen;
1541         struct rvt_qp *qp = packet->qp;
1542         struct hfi1_ibport *ibp;
1543         struct ib_other_headers *ohdr = packet->ohdr;
1544         struct rvt_swqe *wqe;
1545         enum ib_wc_status status;
1546         unsigned long flags;
1547         int diff;
1548         u64 val;
1549         u32 aeth;
1550         u32 psn = ib_bth_get_psn(packet->ohdr);
1551         u32 pmtu = qp->pmtu;
1552         u16 hdrsize = packet->hlen;
1553         u8 opcode = packet->opcode;
1554         u8 pad = packet->pad;
1555         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
1556
1557         spin_lock_irqsave(&qp->s_lock, flags);
1558         trace_hfi1_ack(qp, psn);
1559
1560         /* Ignore invalid responses. */
1561         if (cmp_psn(psn, READ_ONCE(qp->s_next_psn)) >= 0)
1562                 goto ack_done;
1563
1564         /* Ignore duplicate responses. */
1565         diff = cmp_psn(psn, qp->s_last_psn);
1566         if (unlikely(diff <= 0)) {
1567                 /* Update credits for "ghost" ACKs */
1568                 if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
1569                         aeth = be32_to_cpu(ohdr->u.aeth);
1570                         if ((aeth >> IB_AETH_NAK_SHIFT) == 0)
1571                                 rvt_get_credit(qp, aeth);
1572                 }
1573                 goto ack_done;
1574         }
1575
1576         /*
1577          * Skip everything other than the PSN we expect, if we are waiting
1578          * for a reply to a restarted RDMA read or atomic op.
1579          */
1580         if (qp->r_flags & RVT_R_RDMAR_SEQ) {
1581                 if (cmp_psn(psn, qp->s_last_psn + 1) != 0)
1582                         goto ack_done;
1583                 qp->r_flags &= ~RVT_R_RDMAR_SEQ;
1584         }
1585
1586         if (unlikely(qp->s_acked == qp->s_tail))
1587                 goto ack_done;
1588         wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1589         status = IB_WC_SUCCESS;
1590
1591         switch (opcode) {
1592         case OP(ACKNOWLEDGE):
1593         case OP(ATOMIC_ACKNOWLEDGE):
1594         case OP(RDMA_READ_RESPONSE_FIRST):
1595                 aeth = be32_to_cpu(ohdr->u.aeth);
1596                 if (opcode == OP(ATOMIC_ACKNOWLEDGE))
1597                         val = ib_u64_get(&ohdr->u.at.atomic_ack_eth);
1598                 else
1599                         val = 0;
1600                 if (!do_rc_ack(qp, aeth, psn, opcode, val, rcd) ||
1601                     opcode != OP(RDMA_READ_RESPONSE_FIRST))
1602                         goto ack_done;
1603                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1604                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1605                         goto ack_op_err;
1606                 /*
1607                  * If this is a response to a resent RDMA read, we
1608                  * have to be careful to copy the data to the right
1609                  * location.
1610                  */
1611                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1612                                                   wqe, psn, pmtu);
1613                 goto read_middle;
1614
1615         case OP(RDMA_READ_RESPONSE_MIDDLE):
1616                 /* no AETH, no ACK */
1617                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
1618                         goto ack_seq_err;
1619                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1620                         goto ack_op_err;
1621 read_middle:
1622                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
1623                         goto ack_len_err;
1624                 if (unlikely(pmtu >= qp->s_rdma_read_len))
1625                         goto ack_len_err;
1626
1627                 /*
1628                  * We got a response so update the timeout.
1629                  * 4.096 usec. * (1 << qp->timeout)
1630                  */
1631                 rvt_mod_retry_timer(qp);
1632                 if (qp->s_flags & RVT_S_WAIT_ACK) {
1633                         qp->s_flags &= ~RVT_S_WAIT_ACK;
1634                         hfi1_schedule_send(qp);
1635                 }
1636
1637                 if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
1638                         qp->s_retry = qp->s_retry_cnt;
1639
1640                 /*
1641                  * Update the RDMA receive state but do the copy w/o
1642                  * holding the locks and blocking interrupts.
1643                  */
1644                 qp->s_rdma_read_len -= pmtu;
1645                 update_last_psn(qp, psn);
1646                 spin_unlock_irqrestore(&qp->s_lock, flags);
1647                 hfi1_copy_sge(&qp->s_rdma_read_sge, data, pmtu, false, false);
1648                 goto bail;
1649
1650         case OP(RDMA_READ_RESPONSE_ONLY):
1651                 aeth = be32_to_cpu(ohdr->u.aeth);
1652                 if (!do_rc_ack(qp, aeth, psn, opcode, 0, rcd))
1653                         goto ack_done;
1654                 /*
1655                  * Check that the data size is >= 0 && <= pmtu.
1656                  * Remember to account for ICRC (4).
1657                  */
1658                 if (unlikely(tlen < (hdrsize + extra_bytes)))
1659                         goto ack_len_err;
1660                 /*
1661                  * If this is a response to a resent RDMA read, we
1662                  * have to be careful to copy the data to the right
1663                  * location.
1664                  */
1665                 wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1666                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1667                                                   wqe, psn, pmtu);
1668                 goto read_last;
1669
1670         case OP(RDMA_READ_RESPONSE_LAST):
1671                 /* ACKs READ req. */
1672                 if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
1673                         goto ack_seq_err;
1674                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1675                         goto ack_op_err;
1676                 /*
1677                  * Check that the data size is >= 1 && <= pmtu.
1678                  * Remember to account for ICRC (4).
1679                  */
1680                 if (unlikely(tlen <= (hdrsize + extra_bytes)))
1681                         goto ack_len_err;
1682 read_last:
1683                 tlen -= hdrsize + extra_bytes;
1684                 if (unlikely(tlen != qp->s_rdma_read_len))
1685                         goto ack_len_err;
1686                 aeth = be32_to_cpu(ohdr->u.aeth);
1687                 hfi1_copy_sge(&qp->s_rdma_read_sge, data, tlen, false, false);
1688                 WARN_ON(qp->s_rdma_read_sge.num_sge);
1689                 (void)do_rc_ack(qp, aeth, psn,
1690                                  OP(RDMA_READ_RESPONSE_LAST), 0, rcd);
1691                 goto ack_done;
1692         }
1693
1694 ack_op_err:
1695         status = IB_WC_LOC_QP_OP_ERR;
1696         goto ack_err;
1697
1698 ack_seq_err:
1699         ibp = rcd_to_iport(rcd);
1700         rdma_seq_err(qp, ibp, psn, rcd);
1701         goto ack_done;
1702
1703 ack_len_err:
1704         status = IB_WC_LOC_LEN_ERR;
1705 ack_err:
1706         if (qp->s_last == qp->s_acked) {
1707                 hfi1_send_complete(qp, wqe, status);
1708                 rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1709         }
1710 ack_done:
1711         spin_unlock_irqrestore(&qp->s_lock, flags);
1712 bail:
1713         return;
1714 }
1715
1716 static inline void rc_defered_ack(struct hfi1_ctxtdata *rcd,
1717                                   struct rvt_qp *qp)
1718 {
1719         if (list_empty(&qp->rspwait)) {
1720                 qp->r_flags |= RVT_R_RSP_NAK;
1721                 rvt_get_qp(qp);
1722                 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1723         }
1724 }
1725
1726 static inline void rc_cancel_ack(struct rvt_qp *qp)
1727 {
1728         qp->r_adefered = 0;
1729         if (list_empty(&qp->rspwait))
1730                 return;
1731         list_del_init(&qp->rspwait);
1732         qp->r_flags &= ~RVT_R_RSP_NAK;
1733         rvt_put_qp(qp);
1734 }
1735
1736 /**
1737  * rc_rcv_error - process an incoming duplicate or error RC packet
1738  * @ohdr: the other headers for this packet
1739  * @data: the packet data
1740  * @qp: the QP for this packet
1741  * @opcode: the opcode for this packet
1742  * @psn: the packet sequence number for this packet
1743  * @diff: the difference between the PSN and the expected PSN
1744  *
1745  * This is called from hfi1_rc_rcv() to process an unexpected
1746  * incoming RC packet for the given QP.
1747  * Called at interrupt level.
1748  * Return 1 if no more processing is needed; otherwise return 0 to
1749  * schedule a response to be sent.
1750  */
1751 static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
1752                                  struct rvt_qp *qp, u32 opcode, u32 psn,
1753                                  int diff, struct hfi1_ctxtdata *rcd)
1754 {
1755         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
1756         struct rvt_ack_entry *e;
1757         unsigned long flags;
1758         u8 i, prev;
1759         int old_req;
1760
1761         trace_hfi1_rcv_error(qp, psn);
1762         if (diff > 0) {
1763                 /*
1764                  * Packet sequence error.
1765                  * A NAK will ACK earlier sends and RDMA writes.
1766                  * Don't queue the NAK if we already sent one.
1767                  */
1768                 if (!qp->r_nak_state) {
1769                         ibp->rvp.n_rc_seqnak++;
1770                         qp->r_nak_state = IB_NAK_PSN_ERROR;
1771                         /* Use the expected PSN. */
1772                         qp->r_ack_psn = qp->r_psn;
1773                         /*
1774                          * Wait to send the sequence NAK until all packets
1775                          * in the receive queue have been processed.
1776                          * Otherwise, we end up propagating congestion.
1777                          */
1778                         rc_defered_ack(rcd, qp);
1779                 }
1780                 goto done;
1781         }
1782
1783         /*
1784          * Handle a duplicate request.  Don't re-execute SEND, RDMA
1785          * write or atomic op.  Don't NAK errors, just silently drop
1786          * the duplicate request.  Note that r_sge, r_len, and
1787          * r_rcv_len may be in use so don't modify them.
1788          *
1789          * We are supposed to ACK the earliest duplicate PSN but we
1790          * can coalesce an outstanding duplicate ACK.  We have to
1791          * send the earliest so that RDMA reads can be restarted at
1792          * the requester's expected PSN.
1793          *
1794          * First, find where this duplicate PSN falls within the
1795          * ACKs previously sent.
1796          * old_req is true if there is an older response that is scheduled
1797          * to be sent before sending this one.
1798          */
1799         e = NULL;
1800         old_req = 1;
1801         ibp->rvp.n_rc_dupreq++;
1802
1803         spin_lock_irqsave(&qp->s_lock, flags);
1804
1805         for (i = qp->r_head_ack_queue; ; i = prev) {
1806                 if (i == qp->s_tail_ack_queue)
1807                         old_req = 0;
1808                 if (i)
1809                         prev = i - 1;
1810                 else
1811                         prev = HFI1_MAX_RDMA_ATOMIC;
1812                 if (prev == qp->r_head_ack_queue) {
1813                         e = NULL;
1814                         break;
1815                 }
1816                 e = &qp->s_ack_queue[prev];
1817                 if (!e->opcode) {
1818                         e = NULL;
1819                         break;
1820                 }
1821                 if (cmp_psn(psn, e->psn) >= 0) {
1822                         if (prev == qp->s_tail_ack_queue &&
1823                             cmp_psn(psn, e->lpsn) <= 0)
1824                                 old_req = 0;
1825                         break;
1826                 }
1827         }
1828         switch (opcode) {
1829         case OP(RDMA_READ_REQUEST): {
1830                 struct ib_reth *reth;
1831                 u32 offset;
1832                 u32 len;
1833
1834                 /*
1835                  * If we didn't find the RDMA read request in the ack queue,
1836                  * we can ignore this request.
1837                  */
1838                 if (!e || e->opcode != OP(RDMA_READ_REQUEST))
1839                         goto unlock_done;
1840                 /* RETH comes after BTH */
1841                 reth = &ohdr->u.rc.reth;
1842                 /*
1843                  * Address range must be a subset of the original
1844                  * request and start on pmtu boundaries.
1845                  * We reuse the old ack_queue slot since the requester
1846                  * should not back up and request an earlier PSN for the
1847                  * same request.
1848                  */
1849                 offset = delta_psn(psn, e->psn) * qp->pmtu;
1850                 len = be32_to_cpu(reth->length);
1851                 if (unlikely(offset + len != e->rdma_sge.sge_length))
1852                         goto unlock_done;
1853                 if (e->rdma_sge.mr) {
1854                         rvt_put_mr(e->rdma_sge.mr);
1855                         e->rdma_sge.mr = NULL;
1856                 }
1857                 if (len != 0) {
1858                         u32 rkey = be32_to_cpu(reth->rkey);
1859                         u64 vaddr = get_ib_reth_vaddr(reth);
1860                         int ok;
1861
1862                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey,
1863                                          IB_ACCESS_REMOTE_READ);
1864                         if (unlikely(!ok))
1865                                 goto unlock_done;
1866                 } else {
1867                         e->rdma_sge.vaddr = NULL;
1868                         e->rdma_sge.length = 0;
1869                         e->rdma_sge.sge_length = 0;
1870                 }
1871                 e->psn = psn;
1872                 if (old_req)
1873                         goto unlock_done;
1874                 qp->s_tail_ack_queue = prev;
1875                 break;
1876         }
1877
1878         case OP(COMPARE_SWAP):
1879         case OP(FETCH_ADD): {
1880                 /*
1881                  * If we didn't find the atomic request in the ack queue
1882                  * or the send engine is already backed up to send an
1883                  * earlier entry, we can ignore this request.
1884                  */
1885                 if (!e || e->opcode != (u8)opcode || old_req)
1886                         goto unlock_done;
1887                 qp->s_tail_ack_queue = prev;
1888                 break;
1889         }
1890
1891         default:
1892                 /*
1893                  * Ignore this operation if it doesn't request an ACK
1894                  * or an earlier RDMA read or atomic is going to be resent.
1895                  */
1896                 if (!(psn & IB_BTH_REQ_ACK) || old_req)
1897                         goto unlock_done;
1898                 /*
1899                  * Resend the most recent ACK if this request is
1900                  * after all the previous RDMA reads and atomics.
1901                  */
1902                 if (i == qp->r_head_ack_queue) {
1903                         spin_unlock_irqrestore(&qp->s_lock, flags);
1904                         qp->r_nak_state = 0;
1905                         qp->r_ack_psn = qp->r_psn - 1;
1906                         goto send_ack;
1907                 }
1908
1909                 /*
1910                  * Resend the RDMA read or atomic op which
1911                  * ACKs this duplicate request.
1912                  */
1913                 qp->s_tail_ack_queue = i;
1914                 break;
1915         }
1916         qp->s_ack_state = OP(ACKNOWLEDGE);
1917         qp->s_flags |= RVT_S_RESP_PENDING;
1918         qp->r_nak_state = 0;
1919         hfi1_schedule_send(qp);
1920
1921 unlock_done:
1922         spin_unlock_irqrestore(&qp->s_lock, flags);
1923 done:
1924         return 1;
1925
1926 send_ack:
1927         return 0;
1928 }
1929
1930 static inline void update_ack_queue(struct rvt_qp *qp, unsigned n)
1931 {
1932         unsigned next;
1933
1934         next = n + 1;
1935         if (next > HFI1_MAX_RDMA_ATOMIC)
1936                 next = 0;
1937         qp->s_tail_ack_queue = next;
1938         qp->s_ack_state = OP(ACKNOWLEDGE);
1939 }
1940
1941 static void log_cca_event(struct hfi1_pportdata *ppd, u8 sl, u32 rlid,
1942                           u32 lqpn, u32 rqpn, u8 svc_type)
1943 {
1944         struct opa_hfi1_cong_log_event_internal *cc_event;
1945         unsigned long flags;
1946
1947         if (sl >= OPA_MAX_SLS)
1948                 return;
1949
1950         spin_lock_irqsave(&ppd->cc_log_lock, flags);
1951
1952         ppd->threshold_cong_event_map[sl / 8] |= 1 << (sl % 8);
1953         ppd->threshold_event_counter++;
1954
1955         cc_event = &ppd->cc_events[ppd->cc_log_idx++];
1956         if (ppd->cc_log_idx == OPA_CONG_LOG_ELEMS)
1957                 ppd->cc_log_idx = 0;
1958         cc_event->lqpn = lqpn & RVT_QPN_MASK;
1959         cc_event->rqpn = rqpn & RVT_QPN_MASK;
1960         cc_event->sl = sl;
1961         cc_event->svc_type = svc_type;
1962         cc_event->rlid = rlid;
1963         /* keep timestamp in units of 1.024 usec */
1964         cc_event->timestamp = ktime_get_ns() / 1024;
1965
1966         spin_unlock_irqrestore(&ppd->cc_log_lock, flags);
1967 }
1968
1969 void process_becn(struct hfi1_pportdata *ppd, u8 sl, u32 rlid, u32 lqpn,
1970                   u32 rqpn, u8 svc_type)
1971 {
1972         struct cca_timer *cca_timer;
1973         u16 ccti, ccti_incr, ccti_timer, ccti_limit;
1974         u8 trigger_threshold;
1975         struct cc_state *cc_state;
1976         unsigned long flags;
1977
1978         if (sl >= OPA_MAX_SLS)
1979                 return;
1980
1981         cc_state = get_cc_state(ppd);
1982
1983         if (!cc_state)
1984                 return;
1985
1986         /*
1987          * 1) increase CCTI (for this SL)
1988          * 2) select IPG (i.e., call set_link_ipg())
1989          * 3) start timer
1990          */
1991         ccti_limit = cc_state->cct.ccti_limit;
1992         ccti_incr = cc_state->cong_setting.entries[sl].ccti_increase;
1993         ccti_timer = cc_state->cong_setting.entries[sl].ccti_timer;
1994         trigger_threshold =
1995                 cc_state->cong_setting.entries[sl].trigger_threshold;
1996
1997         spin_lock_irqsave(&ppd->cca_timer_lock, flags);
1998
1999         cca_timer = &ppd->cca_timer[sl];
2000         if (cca_timer->ccti < ccti_limit) {
2001                 if (cca_timer->ccti + ccti_incr <= ccti_limit)
2002                         cca_timer->ccti += ccti_incr;
2003                 else
2004                         cca_timer->ccti = ccti_limit;
2005                 set_link_ipg(ppd);
2006         }
2007
2008         ccti = cca_timer->ccti;
2009
2010         if (!hrtimer_active(&cca_timer->hrtimer)) {
2011                 /* ccti_timer is in units of 1.024 usec */
2012                 unsigned long nsec = 1024 * ccti_timer;
2013
2014                 hrtimer_start(&cca_timer->hrtimer, ns_to_ktime(nsec),
2015                               HRTIMER_MODE_REL);
2016         }
2017
2018         spin_unlock_irqrestore(&ppd->cca_timer_lock, flags);
2019
2020         if ((trigger_threshold != 0) && (ccti >= trigger_threshold))
2021                 log_cca_event(ppd, sl, rlid, lqpn, rqpn, svc_type);
2022 }
2023
2024 /**
2025  * hfi1_rc_rcv - process an incoming RC packet
2026  * @packet: data packet information
2027  *
2028  * This is called from qp_rcv() to process an incoming RC packet
2029  * for the given QP.
2030  * May be called at interrupt level.
2031  */
2032 void hfi1_rc_rcv(struct hfi1_packet *packet)
2033 {
2034         struct hfi1_ctxtdata *rcd = packet->rcd;
2035         void *data = packet->payload;
2036         u32 tlen = packet->tlen;
2037         struct rvt_qp *qp = packet->qp;
2038         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
2039         struct ib_other_headers *ohdr = packet->ohdr;
2040         u32 opcode = packet->opcode;
2041         u32 hdrsize = packet->hlen;
2042         u32 psn = ib_bth_get_psn(packet->ohdr);
2043         u32 pad = packet->pad;
2044         struct ib_wc wc;
2045         u32 pmtu = qp->pmtu;
2046         int diff;
2047         struct ib_reth *reth;
2048         unsigned long flags;
2049         int ret;
2050         bool is_fecn = false;
2051         bool copy_last = false;
2052         u32 rkey;
2053         u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
2054
2055         lockdep_assert_held(&qp->r_lock);
2056
2057         if (hfi1_ruc_check_hdr(ibp, packet))
2058                 return;
2059
2060         is_fecn = process_ecn(qp, packet, false);
2061
2062         /*
2063          * Process responses (ACKs) before anything else.  Note that the
2064          * packet sequence number will be for something in the send work
2065          * queue rather than the expected receive packet sequence number.
2066          * In other words, this QP is the requester.
2067          */
2068         if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
2069             opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
2070                 rc_rcv_resp(packet);
2071                 if (is_fecn)
2072                         goto send_ack;
2073                 return;
2074         }
2075
2076         /* Compute 24 bits worth of difference. */
2077         diff = delta_psn(psn, qp->r_psn);
2078         if (unlikely(diff)) {
2079                 if (rc_rcv_error(ohdr, data, qp, opcode, psn, diff, rcd))
2080                         return;
2081                 goto send_ack;
2082         }
2083
2084         /* Check for opcode sequence errors. */
2085         switch (qp->r_state) {
2086         case OP(SEND_FIRST):
2087         case OP(SEND_MIDDLE):
2088                 if (opcode == OP(SEND_MIDDLE) ||
2089                     opcode == OP(SEND_LAST) ||
2090                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2091                     opcode == OP(SEND_LAST_WITH_INVALIDATE))
2092                         break;
2093                 goto nack_inv;
2094
2095         case OP(RDMA_WRITE_FIRST):
2096         case OP(RDMA_WRITE_MIDDLE):
2097                 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
2098                     opcode == OP(RDMA_WRITE_LAST) ||
2099                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2100                         break;
2101                 goto nack_inv;
2102
2103         default:
2104                 if (opcode == OP(SEND_MIDDLE) ||
2105                     opcode == OP(SEND_LAST) ||
2106                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2107                     opcode == OP(SEND_LAST_WITH_INVALIDATE) ||
2108                     opcode == OP(RDMA_WRITE_MIDDLE) ||
2109                     opcode == OP(RDMA_WRITE_LAST) ||
2110                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2111                         goto nack_inv;
2112                 /*
2113                  * Note that it is up to the requester to not send a new
2114                  * RDMA read or atomic operation before receiving an ACK
2115                  * for the previous operation.
2116                  */
2117                 break;
2118         }
2119
2120         if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
2121                 rvt_comm_est(qp);
2122
2123         /* OK, process the packet. */
2124         switch (opcode) {
2125         case OP(SEND_FIRST):
2126                 ret = hfi1_rvt_get_rwqe(qp, 0);
2127                 if (ret < 0)
2128                         goto nack_op_err;
2129                 if (!ret)
2130                         goto rnr_nak;
2131                 qp->r_rcv_len = 0;
2132                 /* FALLTHROUGH */
2133         case OP(SEND_MIDDLE):
2134         case OP(RDMA_WRITE_MIDDLE):
2135 send_middle:
2136                 /* Check for invalid length PMTU or posted rwqe len. */
2137                 /*
2138                  * There will be no padding for 9B packet but 16B packets
2139                  * will come in with some padding since we always add
2140                  * CRC and LT bytes which will need to be flit aligned
2141                  */
2142                 if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
2143                         goto nack_inv;
2144                 qp->r_rcv_len += pmtu;
2145                 if (unlikely(qp->r_rcv_len > qp->r_len))
2146                         goto nack_inv;
2147                 hfi1_copy_sge(&qp->r_sge, data, pmtu, true, false);
2148                 break;
2149
2150         case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
2151                 /* consume RWQE */
2152                 ret = hfi1_rvt_get_rwqe(qp, 1);
2153                 if (ret < 0)
2154                         goto nack_op_err;
2155                 if (!ret)
2156                         goto rnr_nak;
2157                 goto send_last_imm;
2158
2159         case OP(SEND_ONLY):
2160         case OP(SEND_ONLY_WITH_IMMEDIATE):
2161         case OP(SEND_ONLY_WITH_INVALIDATE):
2162                 ret = hfi1_rvt_get_rwqe(qp, 0);
2163                 if (ret < 0)
2164                         goto nack_op_err;
2165                 if (!ret)
2166                         goto rnr_nak;
2167                 qp->r_rcv_len = 0;
2168                 if (opcode == OP(SEND_ONLY))
2169                         goto no_immediate_data;
2170                 if (opcode == OP(SEND_ONLY_WITH_INVALIDATE))
2171                         goto send_last_inv;
2172                 /* FALLTHROUGH -- for SEND_ONLY_WITH_IMMEDIATE */
2173         case OP(SEND_LAST_WITH_IMMEDIATE):
2174 send_last_imm:
2175                 wc.ex.imm_data = ohdr->u.imm_data;
2176                 wc.wc_flags = IB_WC_WITH_IMM;
2177                 goto send_last;
2178         case OP(SEND_LAST_WITH_INVALIDATE):
2179 send_last_inv:
2180                 rkey = be32_to_cpu(ohdr->u.ieth);
2181                 if (rvt_invalidate_rkey(qp, rkey))
2182                         goto no_immediate_data;
2183                 wc.ex.invalidate_rkey = rkey;
2184                 wc.wc_flags = IB_WC_WITH_INVALIDATE;
2185                 goto send_last;
2186         case OP(RDMA_WRITE_LAST):
2187                 copy_last = rvt_is_user_qp(qp);
2188                 /* fall through */
2189         case OP(SEND_LAST):
2190 no_immediate_data:
2191                 wc.wc_flags = 0;
2192                 wc.ex.imm_data = 0;
2193 send_last:
2194                 /* Check for invalid length. */
2195                 /* LAST len should be >= 1 */
2196                 if (unlikely(tlen < (hdrsize + extra_bytes)))
2197                         goto nack_inv;
2198                 /* Don't count the CRC(and padding and LT byte for 16B). */
2199                 tlen -= (hdrsize + extra_bytes);
2200                 wc.byte_len = tlen + qp->r_rcv_len;
2201                 if (unlikely(wc.byte_len > qp->r_len))
2202                         goto nack_inv;
2203                 hfi1_copy_sge(&qp->r_sge, data, tlen, true, copy_last);
2204                 rvt_put_ss(&qp->r_sge);
2205                 qp->r_msn++;
2206                 if (!__test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
2207                         break;
2208                 wc.wr_id = qp->r_wr_id;
2209                 wc.status = IB_WC_SUCCESS;
2210                 if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
2211                     opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
2212                         wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
2213                 else
2214                         wc.opcode = IB_WC_RECV;
2215                 wc.qp = &qp->ibqp;
2216                 wc.src_qp = qp->remote_qpn;
2217                 wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
2218                 /*
2219                  * It seems that IB mandates the presence of an SL in a
2220                  * work completion only for the UD transport (see section
2221                  * 11.4.2 of IBTA Vol. 1).
2222                  *
2223                  * However, the way the SL is chosen below is consistent
2224                  * with the way that IB/qib works and is trying avoid
2225                  * introducing incompatibilities.
2226                  *
2227                  * See also OPA Vol. 1, section 9.7.6, and table 9-17.
2228                  */
2229                 wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
2230                 /* zero fields that are N/A */
2231                 wc.vendor_err = 0;
2232                 wc.pkey_index = 0;
2233                 wc.dlid_path_bits = 0;
2234                 wc.port_num = 0;
2235                 /* Signal completion event if the solicited bit is set. */
2236                 rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
2237                              ib_bth_is_solicited(ohdr));
2238                 break;
2239
2240         case OP(RDMA_WRITE_ONLY):
2241                 copy_last = rvt_is_user_qp(qp);
2242                 /* fall through */
2243         case OP(RDMA_WRITE_FIRST):
2244         case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
2245                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
2246                         goto nack_inv;
2247                 /* consume RWQE */
2248                 reth = &ohdr->u.rc.reth;
2249                 qp->r_len = be32_to_cpu(reth->length);
2250                 qp->r_rcv_len = 0;
2251                 qp->r_sge.sg_list = NULL;
2252                 if (qp->r_len != 0) {
2253                         u32 rkey = be32_to_cpu(reth->rkey);
2254                         u64 vaddr = get_ib_reth_vaddr(reth);
2255                         int ok;
2256
2257                         /* Check rkey & NAK */
2258                         ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len, vaddr,
2259                                          rkey, IB_ACCESS_REMOTE_WRITE);
2260                         if (unlikely(!ok))
2261                                 goto nack_acc;
2262                         qp->r_sge.num_sge = 1;
2263                 } else {
2264                         qp->r_sge.num_sge = 0;
2265                         qp->r_sge.sge.mr = NULL;
2266                         qp->r_sge.sge.vaddr = NULL;
2267                         qp->r_sge.sge.length = 0;
2268                         qp->r_sge.sge.sge_length = 0;
2269                 }
2270                 if (opcode == OP(RDMA_WRITE_FIRST))
2271                         goto send_middle;
2272                 else if (opcode == OP(RDMA_WRITE_ONLY))
2273                         goto no_immediate_data;
2274                 ret = hfi1_rvt_get_rwqe(qp, 1);
2275                 if (ret < 0)
2276                         goto nack_op_err;
2277                 if (!ret) {
2278                         /* peer will send again */
2279                         rvt_put_ss(&qp->r_sge);
2280                         goto rnr_nak;
2281                 }
2282                 wc.ex.imm_data = ohdr->u.rc.imm_data;
2283                 wc.wc_flags = IB_WC_WITH_IMM;
2284                 goto send_last;
2285
2286         case OP(RDMA_READ_REQUEST): {
2287                 struct rvt_ack_entry *e;
2288                 u32 len;
2289                 u8 next;
2290
2291                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
2292                         goto nack_inv;
2293                 next = qp->r_head_ack_queue + 1;
2294                 /* s_ack_queue is size HFI1_MAX_RDMA_ATOMIC+1 so use > not >= */
2295                 if (next > HFI1_MAX_RDMA_ATOMIC)
2296                         next = 0;
2297                 spin_lock_irqsave(&qp->s_lock, flags);
2298                 if (unlikely(next == qp->s_tail_ack_queue)) {
2299                         if (!qp->s_ack_queue[next].sent)
2300                                 goto nack_inv_unlck;
2301                         update_ack_queue(qp, next);
2302                 }
2303                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
2304                 if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
2305                         rvt_put_mr(e->rdma_sge.mr);
2306                         e->rdma_sge.mr = NULL;
2307                 }
2308                 reth = &ohdr->u.rc.reth;
2309                 len = be32_to_cpu(reth->length);
2310                 if (len) {
2311                         u32 rkey = be32_to_cpu(reth->rkey);
2312                         u64 vaddr = get_ib_reth_vaddr(reth);
2313                         int ok;
2314
2315                         /* Check rkey & NAK */
2316                         ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr,
2317                                          rkey, IB_ACCESS_REMOTE_READ);
2318                         if (unlikely(!ok))
2319                                 goto nack_acc_unlck;
2320                         /*
2321                          * Update the next expected PSN.  We add 1 later
2322                          * below, so only add the remainder here.
2323                          */
2324                         qp->r_psn += rvt_div_mtu(qp, len - 1);
2325                 } else {
2326                         e->rdma_sge.mr = NULL;
2327                         e->rdma_sge.vaddr = NULL;
2328                         e->rdma_sge.length = 0;
2329                         e->rdma_sge.sge_length = 0;
2330                 }
2331                 e->opcode = opcode;
2332                 e->sent = 0;
2333                 e->psn = psn;
2334                 e->lpsn = qp->r_psn;
2335                 /*
2336                  * We need to increment the MSN here instead of when we
2337                  * finish sending the result since a duplicate request would
2338                  * increment it more than once.
2339                  */
2340                 qp->r_msn++;
2341                 qp->r_psn++;
2342                 qp->r_state = opcode;
2343                 qp->r_nak_state = 0;
2344                 qp->r_head_ack_queue = next;
2345
2346                 /* Schedule the send engine. */
2347                 qp->s_flags |= RVT_S_RESP_PENDING;
2348                 hfi1_schedule_send(qp);
2349
2350                 spin_unlock_irqrestore(&qp->s_lock, flags);
2351                 if (is_fecn)
2352                         goto send_ack;
2353                 return;
2354         }
2355
2356         case OP(COMPARE_SWAP):
2357         case OP(FETCH_ADD): {
2358                 struct ib_atomic_eth *ateth;
2359                 struct rvt_ack_entry *e;
2360                 u64 vaddr;
2361                 atomic64_t *maddr;
2362                 u64 sdata;
2363                 u32 rkey;
2364                 u8 next;
2365
2366                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
2367                         goto nack_inv;
2368                 next = qp->r_head_ack_queue + 1;
2369                 if (next > HFI1_MAX_RDMA_ATOMIC)
2370                         next = 0;
2371                 spin_lock_irqsave(&qp->s_lock, flags);
2372                 if (unlikely(next == qp->s_tail_ack_queue)) {
2373                         if (!qp->s_ack_queue[next].sent)
2374                                 goto nack_inv_unlck;
2375                         update_ack_queue(qp, next);
2376                 }
2377                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
2378                 if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
2379                         rvt_put_mr(e->rdma_sge.mr);
2380                         e->rdma_sge.mr = NULL;
2381                 }
2382                 ateth = &ohdr->u.atomic_eth;
2383                 vaddr = get_ib_ateth_vaddr(ateth);
2384                 if (unlikely(vaddr & (sizeof(u64) - 1)))
2385                         goto nack_inv_unlck;
2386                 rkey = be32_to_cpu(ateth->rkey);
2387                 /* Check rkey & NAK */
2388                 if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
2389                                           vaddr, rkey,
2390                                           IB_ACCESS_REMOTE_ATOMIC)))
2391                         goto nack_acc_unlck;
2392                 /* Perform atomic OP and save result. */
2393                 maddr = (atomic64_t *)qp->r_sge.sge.vaddr;
2394                 sdata = get_ib_ateth_swap(ateth);
2395                 e->atomic_data = (opcode == OP(FETCH_ADD)) ?
2396                         (u64)atomic64_add_return(sdata, maddr) - sdata :
2397                         (u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr,
2398                                       get_ib_ateth_compare(ateth),
2399                                       sdata);
2400                 rvt_put_mr(qp->r_sge.sge.mr);
2401                 qp->r_sge.num_sge = 0;
2402                 e->opcode = opcode;
2403                 e->sent = 0;
2404                 e->psn = psn;
2405                 e->lpsn = psn;
2406                 qp->r_msn++;
2407                 qp->r_psn++;
2408                 qp->r_state = opcode;
2409                 qp->r_nak_state = 0;
2410                 qp->r_head_ack_queue = next;
2411
2412                 /* Schedule the send engine. */
2413                 qp->s_flags |= RVT_S_RESP_PENDING;
2414                 hfi1_schedule_send(qp);
2415
2416                 spin_unlock_irqrestore(&qp->s_lock, flags);
2417                 if (is_fecn)
2418                         goto send_ack;
2419                 return;
2420         }
2421
2422         default:
2423                 /* NAK unknown opcodes. */
2424                 goto nack_inv;
2425         }
2426         qp->r_psn++;
2427         qp->r_state = opcode;
2428         qp->r_ack_psn = psn;
2429         qp->r_nak_state = 0;
2430         /* Send an ACK if requested or required. */
2431         if (psn & IB_BTH_REQ_ACK) {
2432                 if (packet->numpkt == 0) {
2433                         rc_cancel_ack(qp);
2434                         goto send_ack;
2435                 }
2436                 if (qp->r_adefered >= HFI1_PSN_CREDIT) {
2437                         rc_cancel_ack(qp);
2438                         goto send_ack;
2439                 }
2440                 if (unlikely(is_fecn)) {
2441                         rc_cancel_ack(qp);
2442                         goto send_ack;
2443                 }
2444                 qp->r_adefered++;
2445                 rc_defered_ack(rcd, qp);
2446         }
2447         return;
2448
2449 rnr_nak:
2450         qp->r_nak_state = qp->r_min_rnr_timer | IB_RNR_NAK;
2451         qp->r_ack_psn = qp->r_psn;
2452         /* Queue RNR NAK for later */
2453         rc_defered_ack(rcd, qp);
2454         return;
2455
2456 nack_op_err:
2457         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
2458         qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR;
2459         qp->r_ack_psn = qp->r_psn;
2460         /* Queue NAK for later */
2461         rc_defered_ack(rcd, qp);
2462         return;
2463
2464 nack_inv_unlck:
2465         spin_unlock_irqrestore(&qp->s_lock, flags);
2466 nack_inv:
2467         rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
2468         qp->r_nak_state = IB_NAK_INVALID_REQUEST;
2469         qp->r_ack_psn = qp->r_psn;
2470         /* Queue NAK for later */
2471         rc_defered_ack(rcd, qp);
2472         return;
2473
2474 nack_acc_unlck:
2475         spin_unlock_irqrestore(&qp->s_lock, flags);
2476 nack_acc:
2477         rvt_rc_error(qp, IB_WC_LOC_PROT_ERR);
2478         qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
2479         qp->r_ack_psn = qp->r_psn;
2480 send_ack:
2481         hfi1_send_rc_ack(packet, is_fecn);
2482 }
2483
2484 void hfi1_rc_hdrerr(
2485         struct hfi1_ctxtdata *rcd,
2486         struct hfi1_packet *packet,
2487         struct rvt_qp *qp)
2488 {
2489         struct hfi1_ibport *ibp = rcd_to_iport(rcd);
2490         int diff;
2491         u32 opcode;
2492         u32 psn;
2493
2494         if (hfi1_ruc_check_hdr(ibp, packet))
2495                 return;
2496
2497         psn = ib_bth_get_psn(packet->ohdr);
2498         opcode = ib_bth_get_opcode(packet->ohdr);
2499
2500         /* Only deal with RDMA Writes for now */
2501         if (opcode < IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) {
2502                 diff = delta_psn(psn, qp->r_psn);
2503                 if (!qp->r_nak_state && diff >= 0) {
2504                         ibp->rvp.n_rc_seqnak++;
2505                         qp->r_nak_state = IB_NAK_PSN_ERROR;
2506                         /* Use the expected PSN. */
2507                         qp->r_ack_psn = qp->r_psn;
2508                         /*
2509                          * Wait to send the sequence
2510                          * NAK until all packets
2511                          * in the receive queue have
2512                          * been processed.
2513                          * Otherwise, we end up
2514                          * propagating congestion.
2515                          */
2516                         rc_defered_ack(rcd, qp);
2517                 } /* Out of sequence NAK */
2518         } /* QP Request NAKs */
2519 }