xref: /openbmc/linux/drivers/infiniband/hw/hfi1/rc.c (revision 8730046c)
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 /**
61  * hfi1_add_retry_timer - add/start a retry timer
62  * @qp - the QP
63  *
64  * add a retry timer on the QP
65  */
66 static inline void hfi1_add_retry_timer(struct rvt_qp *qp)
67 {
68 	struct ib_qp *ibqp = &qp->ibqp;
69 	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
70 
71 	lockdep_assert_held(&qp->s_lock);
72 	qp->s_flags |= RVT_S_TIMER;
73 	/* 4.096 usec. * (1 << qp->timeout) */
74 	qp->s_timer.expires = jiffies + qp->timeout_jiffies +
75 			      rdi->busy_jiffies;
76 	add_timer(&qp->s_timer);
77 }
78 
79 /**
80  * hfi1_add_rnr_timer - add/start an rnr timer
81  * @qp - the QP
82  * @to - timeout in usecs
83  *
84  * add an rnr timer on the QP
85  */
86 void hfi1_add_rnr_timer(struct rvt_qp *qp, u32 to)
87 {
88 	struct hfi1_qp_priv *priv = qp->priv;
89 
90 	lockdep_assert_held(&qp->s_lock);
91 	qp->s_flags |= RVT_S_WAIT_RNR;
92 	priv->s_rnr_timer.expires = jiffies + usecs_to_jiffies(to);
93 	add_timer(&priv->s_rnr_timer);
94 }
95 
96 /**
97  * hfi1_mod_retry_timer - mod a retry timer
98  * @qp - the QP
99  *
100  * Modify a potentially already running retry
101  * timer
102  */
103 static inline void hfi1_mod_retry_timer(struct rvt_qp *qp)
104 {
105 	struct ib_qp *ibqp = &qp->ibqp;
106 	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
107 
108 	lockdep_assert_held(&qp->s_lock);
109 	qp->s_flags |= RVT_S_TIMER;
110 	/* 4.096 usec. * (1 << qp->timeout) */
111 	mod_timer(&qp->s_timer, jiffies + qp->timeout_jiffies +
112 		  rdi->busy_jiffies);
113 }
114 
115 /**
116  * hfi1_stop_retry_timer - stop a retry timer
117  * @qp - the QP
118  *
119  * stop a retry timer and return if the timer
120  * had been pending.
121  */
122 static inline int hfi1_stop_retry_timer(struct rvt_qp *qp)
123 {
124 	int rval = 0;
125 
126 	lockdep_assert_held(&qp->s_lock);
127 	/* Remove QP from retry */
128 	if (qp->s_flags & RVT_S_TIMER) {
129 		qp->s_flags &= ~RVT_S_TIMER;
130 		rval = del_timer(&qp->s_timer);
131 	}
132 	return rval;
133 }
134 
135 /**
136  * hfi1_stop_rc_timers - stop all timers
137  * @qp - the QP
138  *
139  * stop any pending timers
140  */
141 void hfi1_stop_rc_timers(struct rvt_qp *qp)
142 {
143 	struct hfi1_qp_priv *priv = qp->priv;
144 
145 	lockdep_assert_held(&qp->s_lock);
146 	/* Remove QP from all timers */
147 	if (qp->s_flags & (RVT_S_TIMER | RVT_S_WAIT_RNR)) {
148 		qp->s_flags &= ~(RVT_S_TIMER | RVT_S_WAIT_RNR);
149 		del_timer(&qp->s_timer);
150 		del_timer(&priv->s_rnr_timer);
151 	}
152 }
153 
154 /**
155  * hfi1_stop_rnr_timer - stop an rnr timer
156  * @qp - the QP
157  *
158  * stop an rnr timer and return if the timer
159  * had been pending.
160  */
161 static inline int hfi1_stop_rnr_timer(struct rvt_qp *qp)
162 {
163 	int rval = 0;
164 	struct hfi1_qp_priv *priv = qp->priv;
165 
166 	lockdep_assert_held(&qp->s_lock);
167 	/* Remove QP from rnr timer */
168 	if (qp->s_flags & RVT_S_WAIT_RNR) {
169 		qp->s_flags &= ~RVT_S_WAIT_RNR;
170 		rval = del_timer(&priv->s_rnr_timer);
171 	}
172 	return rval;
173 }
174 
175 /**
176  * hfi1_del_timers_sync - wait for any timeout routines to exit
177  * @qp - the QP
178  */
179 void hfi1_del_timers_sync(struct rvt_qp *qp)
180 {
181 	struct hfi1_qp_priv *priv = qp->priv;
182 
183 	del_timer_sync(&qp->s_timer);
184 	del_timer_sync(&priv->s_rnr_timer);
185 }
186 
187 static u32 restart_sge(struct rvt_sge_state *ss, struct rvt_swqe *wqe,
188 		       u32 psn, u32 pmtu)
189 {
190 	u32 len;
191 
192 	len = delta_psn(psn, wqe->psn) * pmtu;
193 	ss->sge = wqe->sg_list[0];
194 	ss->sg_list = wqe->sg_list + 1;
195 	ss->num_sge = wqe->wr.num_sge;
196 	ss->total_len = wqe->length;
197 	hfi1_skip_sge(ss, len, 0);
198 	return wqe->length - len;
199 }
200 
201 /**
202  * make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
203  * @dev: the device for this QP
204  * @qp: a pointer to the QP
205  * @ohdr: a pointer to the IB header being constructed
206  * @ps: the xmit packet state
207  *
208  * Return 1 if constructed; otherwise, return 0.
209  * Note that we are in the responder's side of the QP context.
210  * Note the QP s_lock must be held.
211  */
212 static int make_rc_ack(struct hfi1_ibdev *dev, struct rvt_qp *qp,
213 		       struct ib_other_headers *ohdr,
214 		       struct hfi1_pkt_state *ps)
215 {
216 	struct rvt_ack_entry *e;
217 	u32 hwords;
218 	u32 len;
219 	u32 bth0;
220 	u32 bth2;
221 	int middle = 0;
222 	u32 pmtu = qp->pmtu;
223 	struct hfi1_qp_priv *priv = qp->priv;
224 
225 	lockdep_assert_held(&qp->s_lock);
226 	/* Don't send an ACK if we aren't supposed to. */
227 	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
228 		goto bail;
229 
230 	/* header size in 32-bit words LRH+BTH = (8+12)/4. */
231 	hwords = 5;
232 
233 	switch (qp->s_ack_state) {
234 	case OP(RDMA_READ_RESPONSE_LAST):
235 	case OP(RDMA_READ_RESPONSE_ONLY):
236 		e = &qp->s_ack_queue[qp->s_tail_ack_queue];
237 		if (e->rdma_sge.mr) {
238 			rvt_put_mr(e->rdma_sge.mr);
239 			e->rdma_sge.mr = NULL;
240 		}
241 		/* FALLTHROUGH */
242 	case OP(ATOMIC_ACKNOWLEDGE):
243 		/*
244 		 * We can increment the tail pointer now that the last
245 		 * response has been sent instead of only being
246 		 * constructed.
247 		 */
248 		if (++qp->s_tail_ack_queue > HFI1_MAX_RDMA_ATOMIC)
249 			qp->s_tail_ack_queue = 0;
250 		/* FALLTHROUGH */
251 	case OP(SEND_ONLY):
252 	case OP(ACKNOWLEDGE):
253 		/* Check for no next entry in the queue. */
254 		if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
255 			if (qp->s_flags & RVT_S_ACK_PENDING)
256 				goto normal;
257 			goto bail;
258 		}
259 
260 		e = &qp->s_ack_queue[qp->s_tail_ack_queue];
261 		if (e->opcode == OP(RDMA_READ_REQUEST)) {
262 			/*
263 			 * If a RDMA read response is being resent and
264 			 * we haven't seen the duplicate request yet,
265 			 * then stop sending the remaining responses the
266 			 * responder has seen until the requester re-sends it.
267 			 */
268 			len = e->rdma_sge.sge_length;
269 			if (len && !e->rdma_sge.mr) {
270 				qp->s_tail_ack_queue = qp->r_head_ack_queue;
271 				goto bail;
272 			}
273 			/* Copy SGE state in case we need to resend */
274 			ps->s_txreq->mr = e->rdma_sge.mr;
275 			if (ps->s_txreq->mr)
276 				rvt_get_mr(ps->s_txreq->mr);
277 			qp->s_ack_rdma_sge.sge = e->rdma_sge;
278 			qp->s_ack_rdma_sge.num_sge = 1;
279 			ps->s_txreq->ss = &qp->s_ack_rdma_sge;
280 			if (len > pmtu) {
281 				len = pmtu;
282 				qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
283 			} else {
284 				qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
285 				e->sent = 1;
286 			}
287 			ohdr->u.aeth = hfi1_compute_aeth(qp);
288 			hwords++;
289 			qp->s_ack_rdma_psn = e->psn;
290 			bth2 = mask_psn(qp->s_ack_rdma_psn++);
291 		} else {
292 			/* COMPARE_SWAP or FETCH_ADD */
293 			ps->s_txreq->ss = NULL;
294 			len = 0;
295 			qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
296 			ohdr->u.at.aeth = hfi1_compute_aeth(qp);
297 			ib_u64_put(e->atomic_data, &ohdr->u.at.atomic_ack_eth);
298 			hwords += sizeof(ohdr->u.at) / sizeof(u32);
299 			bth2 = mask_psn(e->psn);
300 			e->sent = 1;
301 		}
302 		bth0 = qp->s_ack_state << 24;
303 		break;
304 
305 	case OP(RDMA_READ_RESPONSE_FIRST):
306 		qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
307 		/* FALLTHROUGH */
308 	case OP(RDMA_READ_RESPONSE_MIDDLE):
309 		ps->s_txreq->ss = &qp->s_ack_rdma_sge;
310 		ps->s_txreq->mr = qp->s_ack_rdma_sge.sge.mr;
311 		if (ps->s_txreq->mr)
312 			rvt_get_mr(ps->s_txreq->mr);
313 		len = qp->s_ack_rdma_sge.sge.sge_length;
314 		if (len > pmtu) {
315 			len = pmtu;
316 			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
317 		} else {
318 			ohdr->u.aeth = hfi1_compute_aeth(qp);
319 			hwords++;
320 			qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
321 			e = &qp->s_ack_queue[qp->s_tail_ack_queue];
322 			e->sent = 1;
323 		}
324 		bth0 = qp->s_ack_state << 24;
325 		bth2 = mask_psn(qp->s_ack_rdma_psn++);
326 		break;
327 
328 	default:
329 normal:
330 		/*
331 		 * Send a regular ACK.
332 		 * Set the s_ack_state so we wait until after sending
333 		 * the ACK before setting s_ack_state to ACKNOWLEDGE
334 		 * (see above).
335 		 */
336 		qp->s_ack_state = OP(SEND_ONLY);
337 		qp->s_flags &= ~RVT_S_ACK_PENDING;
338 		ps->s_txreq->ss = NULL;
339 		if (qp->s_nak_state)
340 			ohdr->u.aeth =
341 				cpu_to_be32((qp->r_msn & HFI1_MSN_MASK) |
342 					    (qp->s_nak_state <<
343 					     HFI1_AETH_CREDIT_SHIFT));
344 		else
345 			ohdr->u.aeth = hfi1_compute_aeth(qp);
346 		hwords++;
347 		len = 0;
348 		bth0 = OP(ACKNOWLEDGE) << 24;
349 		bth2 = mask_psn(qp->s_ack_psn);
350 	}
351 	qp->s_rdma_ack_cnt++;
352 	qp->s_hdrwords = hwords;
353 	ps->s_txreq->sde = priv->s_sde;
354 	ps->s_txreq->s_cur_size = len;
355 	hfi1_make_ruc_header(qp, ohdr, bth0, bth2, middle, ps);
356 	/* pbc */
357 	ps->s_txreq->hdr_dwords = qp->s_hdrwords + 2;
358 	return 1;
359 
360 bail:
361 	qp->s_ack_state = OP(ACKNOWLEDGE);
362 	/*
363 	 * Ensure s_rdma_ack_cnt changes are committed prior to resetting
364 	 * RVT_S_RESP_PENDING
365 	 */
366 	smp_wmb();
367 	qp->s_flags &= ~(RVT_S_RESP_PENDING
368 				| RVT_S_ACK_PENDING
369 				| RVT_S_AHG_VALID);
370 	return 0;
371 }
372 
373 /**
374  * hfi1_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
375  * @qp: a pointer to the QP
376  *
377  * Assumes s_lock is held.
378  *
379  * Return 1 if constructed; otherwise, return 0.
380  */
381 int hfi1_make_rc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
382 {
383 	struct hfi1_qp_priv *priv = qp->priv;
384 	struct hfi1_ibdev *dev = to_idev(qp->ibqp.device);
385 	struct ib_other_headers *ohdr;
386 	struct rvt_sge_state *ss;
387 	struct rvt_swqe *wqe;
388 	/* header size in 32-bit words LRH+BTH = (8+12)/4. */
389 	u32 hwords = 5;
390 	u32 len;
391 	u32 bth0 = 0;
392 	u32 bth2;
393 	u32 pmtu = qp->pmtu;
394 	char newreq;
395 	int middle = 0;
396 	int delta;
397 
398 	lockdep_assert_held(&qp->s_lock);
399 	ps->s_txreq = get_txreq(ps->dev, qp);
400 	if (IS_ERR(ps->s_txreq))
401 		goto bail_no_tx;
402 
403 	ohdr = &ps->s_txreq->phdr.hdr.u.oth;
404 	if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
405 		ohdr = &ps->s_txreq->phdr.hdr.u.l.oth;
406 
407 	/* Sending responses has higher priority over sending requests. */
408 	if ((qp->s_flags & RVT_S_RESP_PENDING) &&
409 	    make_rc_ack(dev, qp, ohdr, ps))
410 		return 1;
411 
412 	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
413 		if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
414 			goto bail;
415 		/* We are in the error state, flush the work request. */
416 		smp_read_barrier_depends(); /* see post_one_send() */
417 		if (qp->s_last == ACCESS_ONCE(qp->s_head))
418 			goto bail;
419 		/* If DMAs are in progress, we can't flush immediately. */
420 		if (iowait_sdma_pending(&priv->s_iowait)) {
421 			qp->s_flags |= RVT_S_WAIT_DMA;
422 			goto bail;
423 		}
424 		clear_ahg(qp);
425 		wqe = rvt_get_swqe_ptr(qp, qp->s_last);
426 		hfi1_send_complete(qp, wqe, qp->s_last != qp->s_acked ?
427 			IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR);
428 		/* will get called again */
429 		goto done_free_tx;
430 	}
431 
432 	if (qp->s_flags & (RVT_S_WAIT_RNR | RVT_S_WAIT_ACK))
433 		goto bail;
434 
435 	if (cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) {
436 		if (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) {
437 			qp->s_flags |= RVT_S_WAIT_PSN;
438 			goto bail;
439 		}
440 		qp->s_sending_psn = qp->s_psn;
441 		qp->s_sending_hpsn = qp->s_psn - 1;
442 	}
443 
444 	/* Send a request. */
445 	wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
446 	switch (qp->s_state) {
447 	default:
448 		if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK))
449 			goto bail;
450 		/*
451 		 * Resend an old request or start a new one.
452 		 *
453 		 * We keep track of the current SWQE so that
454 		 * we don't reset the "furthest progress" state
455 		 * if we need to back up.
456 		 */
457 		newreq = 0;
458 		if (qp->s_cur == qp->s_tail) {
459 			/* Check if send work queue is empty. */
460 			if (qp->s_tail == qp->s_head) {
461 				clear_ahg(qp);
462 				goto bail;
463 			}
464 			/*
465 			 * If a fence is requested, wait for previous
466 			 * RDMA read and atomic operations to finish.
467 			 */
468 			if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
469 			    qp->s_num_rd_atomic) {
470 				qp->s_flags |= RVT_S_WAIT_FENCE;
471 				goto bail;
472 			}
473 			/*
474 			 * Local operations are processed immediately
475 			 * after all prior requests have completed
476 			 */
477 			if (wqe->wr.opcode == IB_WR_REG_MR ||
478 			    wqe->wr.opcode == IB_WR_LOCAL_INV) {
479 				int local_ops = 0;
480 				int err = 0;
481 
482 				if (qp->s_last != qp->s_cur)
483 					goto bail;
484 				if (++qp->s_cur == qp->s_size)
485 					qp->s_cur = 0;
486 				if (++qp->s_tail == qp->s_size)
487 					qp->s_tail = 0;
488 				if (!(wqe->wr.send_flags &
489 				      RVT_SEND_COMPLETION_ONLY)) {
490 					err = rvt_invalidate_rkey(
491 						qp,
492 						wqe->wr.ex.invalidate_rkey);
493 					local_ops = 1;
494 				}
495 				hfi1_send_complete(qp, wqe,
496 						   err ? IB_WC_LOC_PROT_ERR
497 						       : IB_WC_SUCCESS);
498 				if (local_ops)
499 					atomic_dec(&qp->local_ops_pending);
500 				qp->s_hdrwords = 0;
501 				goto done_free_tx;
502 			}
503 
504 			newreq = 1;
505 			qp->s_psn = wqe->psn;
506 		}
507 		/*
508 		 * Note that we have to be careful not to modify the
509 		 * original work request since we may need to resend
510 		 * it.
511 		 */
512 		len = wqe->length;
513 		ss = &qp->s_sge;
514 		bth2 = mask_psn(qp->s_psn);
515 		switch (wqe->wr.opcode) {
516 		case IB_WR_SEND:
517 		case IB_WR_SEND_WITH_IMM:
518 		case IB_WR_SEND_WITH_INV:
519 			/* If no credit, return. */
520 			if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
521 			    cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
522 				qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
523 				goto bail;
524 			}
525 			if (len > pmtu) {
526 				qp->s_state = OP(SEND_FIRST);
527 				len = pmtu;
528 				break;
529 			}
530 			if (wqe->wr.opcode == IB_WR_SEND) {
531 				qp->s_state = OP(SEND_ONLY);
532 			} else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
533 				qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
534 				/* Immediate data comes after the BTH */
535 				ohdr->u.imm_data = wqe->wr.ex.imm_data;
536 				hwords += 1;
537 			} else {
538 				qp->s_state = OP(SEND_ONLY_WITH_INVALIDATE);
539 				/* Invalidate rkey comes after the BTH */
540 				ohdr->u.ieth = cpu_to_be32(
541 						wqe->wr.ex.invalidate_rkey);
542 				hwords += 1;
543 			}
544 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
545 				bth0 |= IB_BTH_SOLICITED;
546 			bth2 |= IB_BTH_REQ_ACK;
547 			if (++qp->s_cur == qp->s_size)
548 				qp->s_cur = 0;
549 			break;
550 
551 		case IB_WR_RDMA_WRITE:
552 			if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
553 				qp->s_lsn++;
554 			/* FALLTHROUGH */
555 		case IB_WR_RDMA_WRITE_WITH_IMM:
556 			/* If no credit, return. */
557 			if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
558 			    cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
559 				qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
560 				goto bail;
561 			}
562 			put_ib_reth_vaddr(
563 				wqe->rdma_wr.remote_addr,
564 				&ohdr->u.rc.reth);
565 			ohdr->u.rc.reth.rkey =
566 				cpu_to_be32(wqe->rdma_wr.rkey);
567 			ohdr->u.rc.reth.length = cpu_to_be32(len);
568 			hwords += sizeof(struct ib_reth) / sizeof(u32);
569 			if (len > pmtu) {
570 				qp->s_state = OP(RDMA_WRITE_FIRST);
571 				len = pmtu;
572 				break;
573 			}
574 			if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
575 				qp->s_state = OP(RDMA_WRITE_ONLY);
576 			} else {
577 				qp->s_state =
578 					OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
579 				/* Immediate data comes after RETH */
580 				ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
581 				hwords += 1;
582 				if (wqe->wr.send_flags & IB_SEND_SOLICITED)
583 					bth0 |= IB_BTH_SOLICITED;
584 			}
585 			bth2 |= IB_BTH_REQ_ACK;
586 			if (++qp->s_cur == qp->s_size)
587 				qp->s_cur = 0;
588 			break;
589 
590 		case IB_WR_RDMA_READ:
591 			/*
592 			 * Don't allow more operations to be started
593 			 * than the QP limits allow.
594 			 */
595 			if (newreq) {
596 				if (qp->s_num_rd_atomic >=
597 				    qp->s_max_rd_atomic) {
598 					qp->s_flags |= RVT_S_WAIT_RDMAR;
599 					goto bail;
600 				}
601 				qp->s_num_rd_atomic++;
602 				if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
603 					qp->s_lsn++;
604 			}
605 			put_ib_reth_vaddr(
606 				wqe->rdma_wr.remote_addr,
607 				&ohdr->u.rc.reth);
608 			ohdr->u.rc.reth.rkey =
609 				cpu_to_be32(wqe->rdma_wr.rkey);
610 			ohdr->u.rc.reth.length = cpu_to_be32(len);
611 			qp->s_state = OP(RDMA_READ_REQUEST);
612 			hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
613 			ss = NULL;
614 			len = 0;
615 			bth2 |= IB_BTH_REQ_ACK;
616 			if (++qp->s_cur == qp->s_size)
617 				qp->s_cur = 0;
618 			break;
619 
620 		case IB_WR_ATOMIC_CMP_AND_SWP:
621 		case IB_WR_ATOMIC_FETCH_AND_ADD:
622 			/*
623 			 * Don't allow more operations to be started
624 			 * than the QP limits allow.
625 			 */
626 			if (newreq) {
627 				if (qp->s_num_rd_atomic >=
628 				    qp->s_max_rd_atomic) {
629 					qp->s_flags |= RVT_S_WAIT_RDMAR;
630 					goto bail;
631 				}
632 				qp->s_num_rd_atomic++;
633 				if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
634 					qp->s_lsn++;
635 			}
636 			if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP) {
637 				qp->s_state = OP(COMPARE_SWAP);
638 				put_ib_ateth_swap(wqe->atomic_wr.swap,
639 						  &ohdr->u.atomic_eth);
640 				put_ib_ateth_compare(wqe->atomic_wr.compare_add,
641 						     &ohdr->u.atomic_eth);
642 			} else {
643 				qp->s_state = OP(FETCH_ADD);
644 				put_ib_ateth_swap(wqe->atomic_wr.compare_add,
645 						  &ohdr->u.atomic_eth);
646 				put_ib_ateth_compare(0, &ohdr->u.atomic_eth);
647 			}
648 			put_ib_ateth_vaddr(wqe->atomic_wr.remote_addr,
649 					   &ohdr->u.atomic_eth);
650 			ohdr->u.atomic_eth.rkey = cpu_to_be32(
651 				wqe->atomic_wr.rkey);
652 			hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
653 			ss = NULL;
654 			len = 0;
655 			bth2 |= IB_BTH_REQ_ACK;
656 			if (++qp->s_cur == qp->s_size)
657 				qp->s_cur = 0;
658 			break;
659 
660 		default:
661 			goto bail;
662 		}
663 		qp->s_sge.sge = wqe->sg_list[0];
664 		qp->s_sge.sg_list = wqe->sg_list + 1;
665 		qp->s_sge.num_sge = wqe->wr.num_sge;
666 		qp->s_sge.total_len = wqe->length;
667 		qp->s_len = wqe->length;
668 		if (newreq) {
669 			qp->s_tail++;
670 			if (qp->s_tail >= qp->s_size)
671 				qp->s_tail = 0;
672 		}
673 		if (wqe->wr.opcode == IB_WR_RDMA_READ)
674 			qp->s_psn = wqe->lpsn + 1;
675 		else
676 			qp->s_psn++;
677 		break;
678 
679 	case OP(RDMA_READ_RESPONSE_FIRST):
680 		/*
681 		 * qp->s_state is normally set to the opcode of the
682 		 * last packet constructed for new requests and therefore
683 		 * is never set to RDMA read response.
684 		 * RDMA_READ_RESPONSE_FIRST is used by the ACK processing
685 		 * thread to indicate a SEND needs to be restarted from an
686 		 * earlier PSN without interfering with the sending thread.
687 		 * See restart_rc().
688 		 */
689 		qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
690 		/* FALLTHROUGH */
691 	case OP(SEND_FIRST):
692 		qp->s_state = OP(SEND_MIDDLE);
693 		/* FALLTHROUGH */
694 	case OP(SEND_MIDDLE):
695 		bth2 = mask_psn(qp->s_psn++);
696 		ss = &qp->s_sge;
697 		len = qp->s_len;
698 		if (len > pmtu) {
699 			len = pmtu;
700 			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
701 			break;
702 		}
703 		if (wqe->wr.opcode == IB_WR_SEND) {
704 			qp->s_state = OP(SEND_LAST);
705 		} else if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
706 			qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
707 			/* Immediate data comes after the BTH */
708 			ohdr->u.imm_data = wqe->wr.ex.imm_data;
709 			hwords += 1;
710 		} else {
711 			qp->s_state = OP(SEND_LAST_WITH_INVALIDATE);
712 			/* invalidate data comes after the BTH */
713 			ohdr->u.ieth = cpu_to_be32(wqe->wr.ex.invalidate_rkey);
714 			hwords += 1;
715 		}
716 		if (wqe->wr.send_flags & IB_SEND_SOLICITED)
717 			bth0 |= IB_BTH_SOLICITED;
718 		bth2 |= IB_BTH_REQ_ACK;
719 		qp->s_cur++;
720 		if (qp->s_cur >= qp->s_size)
721 			qp->s_cur = 0;
722 		break;
723 
724 	case OP(RDMA_READ_RESPONSE_LAST):
725 		/*
726 		 * qp->s_state is normally set to the opcode of the
727 		 * last packet constructed for new requests and therefore
728 		 * is never set to RDMA read response.
729 		 * RDMA_READ_RESPONSE_LAST is used by the ACK processing
730 		 * thread to indicate a RDMA write needs to be restarted from
731 		 * an earlier PSN without interfering with the sending thread.
732 		 * See restart_rc().
733 		 */
734 		qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
735 		/* FALLTHROUGH */
736 	case OP(RDMA_WRITE_FIRST):
737 		qp->s_state = OP(RDMA_WRITE_MIDDLE);
738 		/* FALLTHROUGH */
739 	case OP(RDMA_WRITE_MIDDLE):
740 		bth2 = mask_psn(qp->s_psn++);
741 		ss = &qp->s_sge;
742 		len = qp->s_len;
743 		if (len > pmtu) {
744 			len = pmtu;
745 			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
746 			break;
747 		}
748 		if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
749 			qp->s_state = OP(RDMA_WRITE_LAST);
750 		} else {
751 			qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
752 			/* Immediate data comes after the BTH */
753 			ohdr->u.imm_data = wqe->wr.ex.imm_data;
754 			hwords += 1;
755 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
756 				bth0 |= IB_BTH_SOLICITED;
757 		}
758 		bth2 |= IB_BTH_REQ_ACK;
759 		qp->s_cur++;
760 		if (qp->s_cur >= qp->s_size)
761 			qp->s_cur = 0;
762 		break;
763 
764 	case OP(RDMA_READ_RESPONSE_MIDDLE):
765 		/*
766 		 * qp->s_state is normally set to the opcode of the
767 		 * last packet constructed for new requests and therefore
768 		 * is never set to RDMA read response.
769 		 * RDMA_READ_RESPONSE_MIDDLE is used by the ACK processing
770 		 * thread to indicate a RDMA read needs to be restarted from
771 		 * an earlier PSN without interfering with the sending thread.
772 		 * See restart_rc().
773 		 */
774 		len = (delta_psn(qp->s_psn, wqe->psn)) * pmtu;
775 		put_ib_reth_vaddr(
776 			wqe->rdma_wr.remote_addr + len,
777 			&ohdr->u.rc.reth);
778 		ohdr->u.rc.reth.rkey =
779 			cpu_to_be32(wqe->rdma_wr.rkey);
780 		ohdr->u.rc.reth.length = cpu_to_be32(wqe->length - len);
781 		qp->s_state = OP(RDMA_READ_REQUEST);
782 		hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
783 		bth2 = mask_psn(qp->s_psn) | IB_BTH_REQ_ACK;
784 		qp->s_psn = wqe->lpsn + 1;
785 		ss = NULL;
786 		len = 0;
787 		qp->s_cur++;
788 		if (qp->s_cur == qp->s_size)
789 			qp->s_cur = 0;
790 		break;
791 	}
792 	qp->s_sending_hpsn = bth2;
793 	delta = delta_psn(bth2, wqe->psn);
794 	if (delta && delta % HFI1_PSN_CREDIT == 0)
795 		bth2 |= IB_BTH_REQ_ACK;
796 	if (qp->s_flags & RVT_S_SEND_ONE) {
797 		qp->s_flags &= ~RVT_S_SEND_ONE;
798 		qp->s_flags |= RVT_S_WAIT_ACK;
799 		bth2 |= IB_BTH_REQ_ACK;
800 	}
801 	qp->s_len -= len;
802 	qp->s_hdrwords = hwords;
803 	ps->s_txreq->sde = priv->s_sde;
804 	ps->s_txreq->ss = ss;
805 	ps->s_txreq->s_cur_size = len;
806 	hfi1_make_ruc_header(
807 		qp,
808 		ohdr,
809 		bth0 | (qp->s_state << 24),
810 		bth2,
811 		middle,
812 		ps);
813 	/* pbc */
814 	ps->s_txreq->hdr_dwords = qp->s_hdrwords + 2;
815 	return 1;
816 
817 done_free_tx:
818 	hfi1_put_txreq(ps->s_txreq);
819 	ps->s_txreq = NULL;
820 	return 1;
821 
822 bail:
823 	hfi1_put_txreq(ps->s_txreq);
824 
825 bail_no_tx:
826 	ps->s_txreq = NULL;
827 	qp->s_flags &= ~RVT_S_BUSY;
828 	qp->s_hdrwords = 0;
829 	return 0;
830 }
831 
832 /**
833  * hfi1_send_rc_ack - Construct an ACK packet and send it
834  * @qp: a pointer to the QP
835  *
836  * This is called from hfi1_rc_rcv() and handle_receive_interrupt().
837  * Note that RDMA reads and atomics are handled in the
838  * send side QP state and send engine.
839  */
840 void hfi1_send_rc_ack(struct hfi1_ctxtdata *rcd, struct rvt_qp *qp,
841 		      int is_fecn)
842 {
843 	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
844 	struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
845 	u64 pbc, pbc_flags = 0;
846 	u16 lrh0;
847 	u16 sc5;
848 	u32 bth0;
849 	u32 hwords;
850 	u32 vl, plen;
851 	struct send_context *sc;
852 	struct pio_buf *pbuf;
853 	struct ib_header hdr;
854 	struct ib_other_headers *ohdr;
855 	unsigned long flags;
856 
857 	/* Don't send ACK or NAK if a RDMA read or atomic is pending. */
858 	if (qp->s_flags & RVT_S_RESP_PENDING)
859 		goto queue_ack;
860 
861 	/* Ensure s_rdma_ack_cnt changes are committed */
862 	smp_read_barrier_depends();
863 	if (qp->s_rdma_ack_cnt)
864 		goto queue_ack;
865 
866 	/* Construct the header */
867 	/* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4 */
868 	hwords = 6;
869 	if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
870 		hwords += hfi1_make_grh(ibp, &hdr.u.l.grh,
871 				       &qp->remote_ah_attr.grh, hwords, 0);
872 		ohdr = &hdr.u.l.oth;
873 		lrh0 = HFI1_LRH_GRH;
874 	} else {
875 		ohdr = &hdr.u.oth;
876 		lrh0 = HFI1_LRH_BTH;
877 	}
878 	/* read pkey_index w/o lock (its atomic) */
879 	bth0 = hfi1_get_pkey(ibp, qp->s_pkey_index) | (OP(ACKNOWLEDGE) << 24);
880 	if (qp->s_mig_state == IB_MIG_MIGRATED)
881 		bth0 |= IB_BTH_MIG_REQ;
882 	if (qp->r_nak_state)
883 		ohdr->u.aeth = cpu_to_be32((qp->r_msn & HFI1_MSN_MASK) |
884 					    (qp->r_nak_state <<
885 					     HFI1_AETH_CREDIT_SHIFT));
886 	else
887 		ohdr->u.aeth = hfi1_compute_aeth(qp);
888 	sc5 = ibp->sl_to_sc[qp->remote_ah_attr.sl];
889 	/* set PBC_DC_INFO bit (aka SC[4]) in pbc_flags */
890 	pbc_flags |= ((!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT);
891 	lrh0 |= (sc5 & 0xf) << 12 | (qp->remote_ah_attr.sl & 0xf) << 4;
892 	hdr.lrh[0] = cpu_to_be16(lrh0);
893 	hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
894 	hdr.lrh[2] = cpu_to_be16(hwords + SIZE_OF_CRC);
895 	hdr.lrh[3] = cpu_to_be16(ppd->lid | qp->remote_ah_attr.src_path_bits);
896 	ohdr->bth[0] = cpu_to_be32(bth0);
897 	ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
898 	ohdr->bth[1] |= cpu_to_be32((!!is_fecn) << HFI1_BECN_SHIFT);
899 	ohdr->bth[2] = cpu_to_be32(mask_psn(qp->r_ack_psn));
900 
901 	/* Don't try to send ACKs if the link isn't ACTIVE */
902 	if (driver_lstate(ppd) != IB_PORT_ACTIVE)
903 		return;
904 
905 	sc = rcd->sc;
906 	plen = 2 /* PBC */ + hwords;
907 	vl = sc_to_vlt(ppd->dd, sc5);
908 	pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps, vl, plen);
909 
910 	pbuf = sc_buffer_alloc(sc, plen, NULL, NULL);
911 	if (!pbuf) {
912 		/*
913 		 * We have no room to send at the moment.  Pass
914 		 * responsibility for sending the ACK to the send engine
915 		 * so that when enough buffer space becomes available,
916 		 * the ACK is sent ahead of other outgoing packets.
917 		 */
918 		goto queue_ack;
919 	}
920 
921 	trace_ack_output_ibhdr(dd_from_ibdev(qp->ibqp.device), &hdr);
922 
923 	/* write the pbc and data */
924 	ppd->dd->pio_inline_send(ppd->dd, pbuf, pbc, &hdr, hwords);
925 
926 	return;
927 
928 queue_ack:
929 	spin_lock_irqsave(&qp->s_lock, flags);
930 	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
931 		goto unlock;
932 	this_cpu_inc(*ibp->rvp.rc_qacks);
933 	qp->s_flags |= RVT_S_ACK_PENDING | RVT_S_RESP_PENDING;
934 	qp->s_nak_state = qp->r_nak_state;
935 	qp->s_ack_psn = qp->r_ack_psn;
936 	if (is_fecn)
937 		qp->s_flags |= RVT_S_ECN;
938 
939 	/* Schedule the send engine. */
940 	hfi1_schedule_send(qp);
941 unlock:
942 	spin_unlock_irqrestore(&qp->s_lock, flags);
943 }
944 
945 /**
946  * reset_psn - reset the QP state to send starting from PSN
947  * @qp: the QP
948  * @psn: the packet sequence number to restart at
949  *
950  * This is called from hfi1_rc_rcv() to process an incoming RC ACK
951  * for the given QP.
952  * Called at interrupt level with the QP s_lock held.
953  */
954 static void reset_psn(struct rvt_qp *qp, u32 psn)
955 {
956 	u32 n = qp->s_acked;
957 	struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, n);
958 	u32 opcode;
959 
960 	lockdep_assert_held(&qp->s_lock);
961 	qp->s_cur = n;
962 
963 	/*
964 	 * If we are starting the request from the beginning,
965 	 * let the normal send code handle initialization.
966 	 */
967 	if (cmp_psn(psn, wqe->psn) <= 0) {
968 		qp->s_state = OP(SEND_LAST);
969 		goto done;
970 	}
971 
972 	/* Find the work request opcode corresponding to the given PSN. */
973 	opcode = wqe->wr.opcode;
974 	for (;;) {
975 		int diff;
976 
977 		if (++n == qp->s_size)
978 			n = 0;
979 		if (n == qp->s_tail)
980 			break;
981 		wqe = rvt_get_swqe_ptr(qp, n);
982 		diff = cmp_psn(psn, wqe->psn);
983 		if (diff < 0)
984 			break;
985 		qp->s_cur = n;
986 		/*
987 		 * If we are starting the request from the beginning,
988 		 * let the normal send code handle initialization.
989 		 */
990 		if (diff == 0) {
991 			qp->s_state = OP(SEND_LAST);
992 			goto done;
993 		}
994 		opcode = wqe->wr.opcode;
995 	}
996 
997 	/*
998 	 * Set the state to restart in the middle of a request.
999 	 * Don't change the s_sge, s_cur_sge, or s_cur_size.
1000 	 * See hfi1_make_rc_req().
1001 	 */
1002 	switch (opcode) {
1003 	case IB_WR_SEND:
1004 	case IB_WR_SEND_WITH_IMM:
1005 		qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
1006 		break;
1007 
1008 	case IB_WR_RDMA_WRITE:
1009 	case IB_WR_RDMA_WRITE_WITH_IMM:
1010 		qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
1011 		break;
1012 
1013 	case IB_WR_RDMA_READ:
1014 		qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
1015 		break;
1016 
1017 	default:
1018 		/*
1019 		 * This case shouldn't happen since its only
1020 		 * one PSN per req.
1021 		 */
1022 		qp->s_state = OP(SEND_LAST);
1023 	}
1024 done:
1025 	qp->s_psn = psn;
1026 	/*
1027 	 * Set RVT_S_WAIT_PSN as rc_complete() may start the timer
1028 	 * asynchronously before the send engine can get scheduled.
1029 	 * Doing it in hfi1_make_rc_req() is too late.
1030 	 */
1031 	if ((cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) &&
1032 	    (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0))
1033 		qp->s_flags |= RVT_S_WAIT_PSN;
1034 	qp->s_flags &= ~RVT_S_AHG_VALID;
1035 }
1036 
1037 /*
1038  * Back up requester to resend the last un-ACKed request.
1039  * The QP r_lock and s_lock should be held and interrupts disabled.
1040  */
1041 static void restart_rc(struct rvt_qp *qp, u32 psn, int wait)
1042 {
1043 	struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1044 	struct hfi1_ibport *ibp;
1045 
1046 	lockdep_assert_held(&qp->r_lock);
1047 	lockdep_assert_held(&qp->s_lock);
1048 	if (qp->s_retry == 0) {
1049 		if (qp->s_mig_state == IB_MIG_ARMED) {
1050 			hfi1_migrate_qp(qp);
1051 			qp->s_retry = qp->s_retry_cnt;
1052 		} else if (qp->s_last == qp->s_acked) {
1053 			hfi1_send_complete(qp, wqe, IB_WC_RETRY_EXC_ERR);
1054 			rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1055 			return;
1056 		} else { /* need to handle delayed completion */
1057 			return;
1058 		}
1059 	} else {
1060 		qp->s_retry--;
1061 	}
1062 
1063 	ibp = to_iport(qp->ibqp.device, qp->port_num);
1064 	if (wqe->wr.opcode == IB_WR_RDMA_READ)
1065 		ibp->rvp.n_rc_resends++;
1066 	else
1067 		ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
1068 
1069 	qp->s_flags &= ~(RVT_S_WAIT_FENCE | RVT_S_WAIT_RDMAR |
1070 			 RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_PSN |
1071 			 RVT_S_WAIT_ACK);
1072 	if (wait)
1073 		qp->s_flags |= RVT_S_SEND_ONE;
1074 	reset_psn(qp, psn);
1075 }
1076 
1077 /*
1078  * This is called from s_timer for missing responses.
1079  */
1080 void hfi1_rc_timeout(unsigned long arg)
1081 {
1082 	struct rvt_qp *qp = (struct rvt_qp *)arg;
1083 	struct hfi1_ibport *ibp;
1084 	unsigned long flags;
1085 
1086 	spin_lock_irqsave(&qp->r_lock, flags);
1087 	spin_lock(&qp->s_lock);
1088 	if (qp->s_flags & RVT_S_TIMER) {
1089 		ibp = to_iport(qp->ibqp.device, qp->port_num);
1090 		ibp->rvp.n_rc_timeouts++;
1091 		qp->s_flags &= ~RVT_S_TIMER;
1092 		del_timer(&qp->s_timer);
1093 		trace_hfi1_timeout(qp, qp->s_last_psn + 1);
1094 		restart_rc(qp, qp->s_last_psn + 1, 1);
1095 		hfi1_schedule_send(qp);
1096 	}
1097 	spin_unlock(&qp->s_lock);
1098 	spin_unlock_irqrestore(&qp->r_lock, flags);
1099 }
1100 
1101 /*
1102  * This is called from s_timer for RNR timeouts.
1103  */
1104 void hfi1_rc_rnr_retry(unsigned long arg)
1105 {
1106 	struct rvt_qp *qp = (struct rvt_qp *)arg;
1107 	unsigned long flags;
1108 
1109 	spin_lock_irqsave(&qp->s_lock, flags);
1110 	hfi1_stop_rnr_timer(qp);
1111 	hfi1_schedule_send(qp);
1112 	spin_unlock_irqrestore(&qp->s_lock, flags);
1113 }
1114 
1115 /*
1116  * Set qp->s_sending_psn to the next PSN after the given one.
1117  * This would be psn+1 except when RDMA reads are present.
1118  */
1119 static void reset_sending_psn(struct rvt_qp *qp, u32 psn)
1120 {
1121 	struct rvt_swqe *wqe;
1122 	u32 n = qp->s_last;
1123 
1124 	lockdep_assert_held(&qp->s_lock);
1125 	/* Find the work request corresponding to the given PSN. */
1126 	for (;;) {
1127 		wqe = rvt_get_swqe_ptr(qp, n);
1128 		if (cmp_psn(psn, wqe->lpsn) <= 0) {
1129 			if (wqe->wr.opcode == IB_WR_RDMA_READ)
1130 				qp->s_sending_psn = wqe->lpsn + 1;
1131 			else
1132 				qp->s_sending_psn = psn + 1;
1133 			break;
1134 		}
1135 		if (++n == qp->s_size)
1136 			n = 0;
1137 		if (n == qp->s_tail)
1138 			break;
1139 	}
1140 }
1141 
1142 /*
1143  * This should be called with the QP s_lock held and interrupts disabled.
1144  */
1145 void hfi1_rc_send_complete(struct rvt_qp *qp, struct ib_header *hdr)
1146 {
1147 	struct ib_other_headers *ohdr;
1148 	struct rvt_swqe *wqe;
1149 	u32 opcode;
1150 	u32 psn;
1151 
1152 	lockdep_assert_held(&qp->s_lock);
1153 	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_OR_FLUSH_SEND))
1154 		return;
1155 
1156 	/* Find out where the BTH is */
1157 	if ((be16_to_cpu(hdr->lrh[0]) & 3) == HFI1_LRH_BTH)
1158 		ohdr = &hdr->u.oth;
1159 	else
1160 		ohdr = &hdr->u.l.oth;
1161 
1162 	opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
1163 	if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1164 	    opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
1165 		WARN_ON(!qp->s_rdma_ack_cnt);
1166 		qp->s_rdma_ack_cnt--;
1167 		return;
1168 	}
1169 
1170 	psn = be32_to_cpu(ohdr->bth[2]);
1171 	reset_sending_psn(qp, psn);
1172 
1173 	/*
1174 	 * Start timer after a packet requesting an ACK has been sent and
1175 	 * there are still requests that haven't been acked.
1176 	 */
1177 	if ((psn & IB_BTH_REQ_ACK) && qp->s_acked != qp->s_tail &&
1178 	    !(qp->s_flags &
1179 		(RVT_S_TIMER | RVT_S_WAIT_RNR | RVT_S_WAIT_PSN)) &&
1180 		(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
1181 		hfi1_add_retry_timer(qp);
1182 
1183 	while (qp->s_last != qp->s_acked) {
1184 		u32 s_last;
1185 
1186 		wqe = rvt_get_swqe_ptr(qp, qp->s_last);
1187 		if (cmp_psn(wqe->lpsn, qp->s_sending_psn) >= 0 &&
1188 		    cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)
1189 			break;
1190 		s_last = qp->s_last;
1191 		if (++s_last >= qp->s_size)
1192 			s_last = 0;
1193 		qp->s_last = s_last;
1194 		/* see post_send() */
1195 		barrier();
1196 		rvt_put_swqe(wqe);
1197 		rvt_qp_swqe_complete(qp, wqe, IB_WC_SUCCESS);
1198 	}
1199 	/*
1200 	 * If we were waiting for sends to complete before re-sending,
1201 	 * and they are now complete, restart sending.
1202 	 */
1203 	trace_hfi1_sendcomplete(qp, psn);
1204 	if (qp->s_flags & RVT_S_WAIT_PSN &&
1205 	    cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1206 		qp->s_flags &= ~RVT_S_WAIT_PSN;
1207 		qp->s_sending_psn = qp->s_psn;
1208 		qp->s_sending_hpsn = qp->s_psn - 1;
1209 		hfi1_schedule_send(qp);
1210 	}
1211 }
1212 
1213 static inline void update_last_psn(struct rvt_qp *qp, u32 psn)
1214 {
1215 	qp->s_last_psn = psn;
1216 }
1217 
1218 /*
1219  * Generate a SWQE completion.
1220  * This is similar to hfi1_send_complete but has to check to be sure
1221  * that the SGEs are not being referenced if the SWQE is being resent.
1222  */
1223 static struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
1224 					 struct rvt_swqe *wqe,
1225 					 struct hfi1_ibport *ibp)
1226 {
1227 	lockdep_assert_held(&qp->s_lock);
1228 	/*
1229 	 * Don't decrement refcount and don't generate a
1230 	 * completion if the SWQE is being resent until the send
1231 	 * is finished.
1232 	 */
1233 	if (cmp_psn(wqe->lpsn, qp->s_sending_psn) < 0 ||
1234 	    cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1235 		u32 s_last;
1236 
1237 		rvt_put_swqe(wqe);
1238 		s_last = qp->s_last;
1239 		if (++s_last >= qp->s_size)
1240 			s_last = 0;
1241 		qp->s_last = s_last;
1242 		/* see post_send() */
1243 		barrier();
1244 		rvt_qp_swqe_complete(qp, wqe, IB_WC_SUCCESS);
1245 	} else {
1246 		struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
1247 
1248 		this_cpu_inc(*ibp->rvp.rc_delayed_comp);
1249 		/*
1250 		 * If send progress not running attempt to progress
1251 		 * SDMA queue.
1252 		 */
1253 		if (ppd->dd->flags & HFI1_HAS_SEND_DMA) {
1254 			struct sdma_engine *engine;
1255 			u8 sc5;
1256 
1257 			/* For now use sc to find engine */
1258 			sc5 = ibp->sl_to_sc[qp->remote_ah_attr.sl];
1259 			engine = qp_to_sdma_engine(qp, sc5);
1260 			sdma_engine_progress_schedule(engine);
1261 		}
1262 	}
1263 
1264 	qp->s_retry = qp->s_retry_cnt;
1265 	update_last_psn(qp, wqe->lpsn);
1266 
1267 	/*
1268 	 * If we are completing a request which is in the process of
1269 	 * being resent, we can stop re-sending it since we know the
1270 	 * responder has already seen it.
1271 	 */
1272 	if (qp->s_acked == qp->s_cur) {
1273 		if (++qp->s_cur >= qp->s_size)
1274 			qp->s_cur = 0;
1275 		qp->s_acked = qp->s_cur;
1276 		wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
1277 		if (qp->s_acked != qp->s_tail) {
1278 			qp->s_state = OP(SEND_LAST);
1279 			qp->s_psn = wqe->psn;
1280 		}
1281 	} else {
1282 		if (++qp->s_acked >= qp->s_size)
1283 			qp->s_acked = 0;
1284 		if (qp->state == IB_QPS_SQD && qp->s_acked == qp->s_cur)
1285 			qp->s_draining = 0;
1286 		wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1287 	}
1288 	return wqe;
1289 }
1290 
1291 /**
1292  * do_rc_ack - process an incoming RC ACK
1293  * @qp: the QP the ACK came in on
1294  * @psn: the packet sequence number of the ACK
1295  * @opcode: the opcode of the request that resulted in the ACK
1296  *
1297  * This is called from rc_rcv_resp() to process an incoming RC ACK
1298  * for the given QP.
1299  * May be called at interrupt level, with the QP s_lock held.
1300  * Returns 1 if OK, 0 if current operation should be aborted (NAK).
1301  */
1302 static int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode,
1303 		     u64 val, struct hfi1_ctxtdata *rcd)
1304 {
1305 	struct hfi1_ibport *ibp;
1306 	enum ib_wc_status status;
1307 	struct rvt_swqe *wqe;
1308 	int ret = 0;
1309 	u32 ack_psn;
1310 	int diff;
1311 	unsigned long to;
1312 
1313 	lockdep_assert_held(&qp->s_lock);
1314 	/*
1315 	 * Note that NAKs implicitly ACK outstanding SEND and RDMA write
1316 	 * requests and implicitly NAK RDMA read and atomic requests issued
1317 	 * before the NAK'ed request.  The MSN won't include the NAK'ed
1318 	 * request but will include an ACK'ed request(s).
1319 	 */
1320 	ack_psn = psn;
1321 	if (aeth >> 29)
1322 		ack_psn--;
1323 	wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1324 	ibp = to_iport(qp->ibqp.device, qp->port_num);
1325 
1326 	/*
1327 	 * The MSN might be for a later WQE than the PSN indicates so
1328 	 * only complete WQEs that the PSN finishes.
1329 	 */
1330 	while ((diff = delta_psn(ack_psn, wqe->lpsn)) >= 0) {
1331 		/*
1332 		 * RDMA_READ_RESPONSE_ONLY is a special case since
1333 		 * we want to generate completion events for everything
1334 		 * before the RDMA read, copy the data, then generate
1335 		 * the completion for the read.
1336 		 */
1337 		if (wqe->wr.opcode == IB_WR_RDMA_READ &&
1338 		    opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
1339 		    diff == 0) {
1340 			ret = 1;
1341 			goto bail_stop;
1342 		}
1343 		/*
1344 		 * If this request is a RDMA read or atomic, and the ACK is
1345 		 * for a later operation, this ACK NAKs the RDMA read or
1346 		 * atomic.  In other words, only a RDMA_READ_LAST or ONLY
1347 		 * can ACK a RDMA read and likewise for atomic ops.  Note
1348 		 * that the NAK case can only happen if relaxed ordering is
1349 		 * used and requests are sent after an RDMA read or atomic
1350 		 * is sent but before the response is received.
1351 		 */
1352 		if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
1353 		     (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
1354 		    ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1355 		      wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
1356 		     (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0))) {
1357 			/* Retry this request. */
1358 			if (!(qp->r_flags & RVT_R_RDMAR_SEQ)) {
1359 				qp->r_flags |= RVT_R_RDMAR_SEQ;
1360 				restart_rc(qp, qp->s_last_psn + 1, 0);
1361 				if (list_empty(&qp->rspwait)) {
1362 					qp->r_flags |= RVT_R_RSP_SEND;
1363 					rvt_get_qp(qp);
1364 					list_add_tail(&qp->rspwait,
1365 						      &rcd->qp_wait_list);
1366 				}
1367 			}
1368 			/*
1369 			 * No need to process the ACK/NAK since we are
1370 			 * restarting an earlier request.
1371 			 */
1372 			goto bail_stop;
1373 		}
1374 		if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1375 		    wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
1376 			u64 *vaddr = wqe->sg_list[0].vaddr;
1377 			*vaddr = val;
1378 		}
1379 		if (qp->s_num_rd_atomic &&
1380 		    (wqe->wr.opcode == IB_WR_RDMA_READ ||
1381 		     wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1382 		     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
1383 			qp->s_num_rd_atomic--;
1384 			/* Restart sending task if fence is complete */
1385 			if ((qp->s_flags & RVT_S_WAIT_FENCE) &&
1386 			    !qp->s_num_rd_atomic) {
1387 				qp->s_flags &= ~(RVT_S_WAIT_FENCE |
1388 						 RVT_S_WAIT_ACK);
1389 				hfi1_schedule_send(qp);
1390 			} else if (qp->s_flags & RVT_S_WAIT_RDMAR) {
1391 				qp->s_flags &= ~(RVT_S_WAIT_RDMAR |
1392 						 RVT_S_WAIT_ACK);
1393 				hfi1_schedule_send(qp);
1394 			}
1395 		}
1396 		wqe = do_rc_completion(qp, wqe, ibp);
1397 		if (qp->s_acked == qp->s_tail)
1398 			break;
1399 	}
1400 
1401 	switch (aeth >> 29) {
1402 	case 0:         /* ACK */
1403 		this_cpu_inc(*ibp->rvp.rc_acks);
1404 		if (qp->s_acked != qp->s_tail) {
1405 			/*
1406 			 * We are expecting more ACKs so
1407 			 * mod the retry timer.
1408 			 */
1409 			hfi1_mod_retry_timer(qp);
1410 			/*
1411 			 * We can stop re-sending the earlier packets and
1412 			 * continue with the next packet the receiver wants.
1413 			 */
1414 			if (cmp_psn(qp->s_psn, psn) <= 0)
1415 				reset_psn(qp, psn + 1);
1416 		} else {
1417 			/* No more acks - kill all timers */
1418 			hfi1_stop_rc_timers(qp);
1419 			if (cmp_psn(qp->s_psn, psn) <= 0) {
1420 				qp->s_state = OP(SEND_LAST);
1421 				qp->s_psn = psn + 1;
1422 			}
1423 		}
1424 		if (qp->s_flags & RVT_S_WAIT_ACK) {
1425 			qp->s_flags &= ~RVT_S_WAIT_ACK;
1426 			hfi1_schedule_send(qp);
1427 		}
1428 		hfi1_get_credit(qp, aeth);
1429 		qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1430 		qp->s_retry = qp->s_retry_cnt;
1431 		update_last_psn(qp, psn);
1432 		return 1;
1433 
1434 	case 1:         /* RNR NAK */
1435 		ibp->rvp.n_rnr_naks++;
1436 		if (qp->s_acked == qp->s_tail)
1437 			goto bail_stop;
1438 		if (qp->s_flags & RVT_S_WAIT_RNR)
1439 			goto bail_stop;
1440 		if (qp->s_rnr_retry == 0) {
1441 			status = IB_WC_RNR_RETRY_EXC_ERR;
1442 			goto class_b;
1443 		}
1444 		if (qp->s_rnr_retry_cnt < 7)
1445 			qp->s_rnr_retry--;
1446 
1447 		/* The last valid PSN is the previous PSN. */
1448 		update_last_psn(qp, psn - 1);
1449 
1450 		ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
1451 
1452 		reset_psn(qp, psn);
1453 
1454 		qp->s_flags &= ~(RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_ACK);
1455 		hfi1_stop_rc_timers(qp);
1456 		to =
1457 			ib_hfi1_rnr_table[(aeth >> HFI1_AETH_CREDIT_SHIFT) &
1458 					   HFI1_AETH_CREDIT_MASK];
1459 		hfi1_add_rnr_timer(qp, to);
1460 		return 0;
1461 
1462 	case 3:         /* NAK */
1463 		if (qp->s_acked == qp->s_tail)
1464 			goto bail_stop;
1465 		/* The last valid PSN is the previous PSN. */
1466 		update_last_psn(qp, psn - 1);
1467 		switch ((aeth >> HFI1_AETH_CREDIT_SHIFT) &
1468 			HFI1_AETH_CREDIT_MASK) {
1469 		case 0: /* PSN sequence error */
1470 			ibp->rvp.n_seq_naks++;
1471 			/*
1472 			 * Back up to the responder's expected PSN.
1473 			 * Note that we might get a NAK in the middle of an
1474 			 * RDMA READ response which terminates the RDMA
1475 			 * READ.
1476 			 */
1477 			restart_rc(qp, psn, 0);
1478 			hfi1_schedule_send(qp);
1479 			break;
1480 
1481 		case 1: /* Invalid Request */
1482 			status = IB_WC_REM_INV_REQ_ERR;
1483 			ibp->rvp.n_other_naks++;
1484 			goto class_b;
1485 
1486 		case 2: /* Remote Access Error */
1487 			status = IB_WC_REM_ACCESS_ERR;
1488 			ibp->rvp.n_other_naks++;
1489 			goto class_b;
1490 
1491 		case 3: /* Remote Operation Error */
1492 			status = IB_WC_REM_OP_ERR;
1493 			ibp->rvp.n_other_naks++;
1494 class_b:
1495 			if (qp->s_last == qp->s_acked) {
1496 				hfi1_send_complete(qp, wqe, status);
1497 				rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1498 			}
1499 			break;
1500 
1501 		default:
1502 			/* Ignore other reserved NAK error codes */
1503 			goto reserved;
1504 		}
1505 		qp->s_retry = qp->s_retry_cnt;
1506 		qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1507 		goto bail_stop;
1508 
1509 	default:                /* 2: reserved */
1510 reserved:
1511 		/* Ignore reserved NAK codes. */
1512 		goto bail_stop;
1513 	}
1514 	/* cannot be reached  */
1515 bail_stop:
1516 	hfi1_stop_rc_timers(qp);
1517 	return ret;
1518 }
1519 
1520 /*
1521  * We have seen an out of sequence RDMA read middle or last packet.
1522  * This ACKs SENDs and RDMA writes up to the first RDMA read or atomic SWQE.
1523  */
1524 static void rdma_seq_err(struct rvt_qp *qp, struct hfi1_ibport *ibp, u32 psn,
1525 			 struct hfi1_ctxtdata *rcd)
1526 {
1527 	struct rvt_swqe *wqe;
1528 
1529 	lockdep_assert_held(&qp->s_lock);
1530 	/* Remove QP from retry timer */
1531 	hfi1_stop_rc_timers(qp);
1532 
1533 	wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1534 
1535 	while (cmp_psn(psn, wqe->lpsn) > 0) {
1536 		if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1537 		    wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1538 		    wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
1539 			break;
1540 		wqe = do_rc_completion(qp, wqe, ibp);
1541 	}
1542 
1543 	ibp->rvp.n_rdma_seq++;
1544 	qp->r_flags |= RVT_R_RDMAR_SEQ;
1545 	restart_rc(qp, qp->s_last_psn + 1, 0);
1546 	if (list_empty(&qp->rspwait)) {
1547 		qp->r_flags |= RVT_R_RSP_SEND;
1548 		rvt_get_qp(qp);
1549 		list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1550 	}
1551 }
1552 
1553 /**
1554  * rc_rcv_resp - process an incoming RC response packet
1555  * @ibp: the port this packet came in on
1556  * @ohdr: the other headers for this packet
1557  * @data: the packet data
1558  * @tlen: the packet length
1559  * @qp: the QP for this packet
1560  * @opcode: the opcode for this packet
1561  * @psn: the packet sequence number for this packet
1562  * @hdrsize: the header length
1563  * @pmtu: the path MTU
1564  *
1565  * This is called from hfi1_rc_rcv() to process an incoming RC response
1566  * packet for the given QP.
1567  * Called at interrupt level.
1568  */
1569 static void rc_rcv_resp(struct hfi1_ibport *ibp,
1570 			struct ib_other_headers *ohdr,
1571 			void *data, u32 tlen, struct rvt_qp *qp,
1572 			u32 opcode, u32 psn, u32 hdrsize, u32 pmtu,
1573 			struct hfi1_ctxtdata *rcd)
1574 {
1575 	struct rvt_swqe *wqe;
1576 	enum ib_wc_status status;
1577 	unsigned long flags;
1578 	int diff;
1579 	u32 pad;
1580 	u32 aeth;
1581 	u64 val;
1582 
1583 	spin_lock_irqsave(&qp->s_lock, flags);
1584 
1585 	trace_hfi1_ack(qp, psn);
1586 
1587 	/* Ignore invalid responses. */
1588 	smp_read_barrier_depends(); /* see post_one_send */
1589 	if (cmp_psn(psn, ACCESS_ONCE(qp->s_next_psn)) >= 0)
1590 		goto ack_done;
1591 
1592 	/* Ignore duplicate responses. */
1593 	diff = cmp_psn(psn, qp->s_last_psn);
1594 	if (unlikely(diff <= 0)) {
1595 		/* Update credits for "ghost" ACKs */
1596 		if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
1597 			aeth = be32_to_cpu(ohdr->u.aeth);
1598 			if ((aeth >> 29) == 0)
1599 				hfi1_get_credit(qp, aeth);
1600 		}
1601 		goto ack_done;
1602 	}
1603 
1604 	/*
1605 	 * Skip everything other than the PSN we expect, if we are waiting
1606 	 * for a reply to a restarted RDMA read or atomic op.
1607 	 */
1608 	if (qp->r_flags & RVT_R_RDMAR_SEQ) {
1609 		if (cmp_psn(psn, qp->s_last_psn + 1) != 0)
1610 			goto ack_done;
1611 		qp->r_flags &= ~RVT_R_RDMAR_SEQ;
1612 	}
1613 
1614 	if (unlikely(qp->s_acked == qp->s_tail))
1615 		goto ack_done;
1616 	wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1617 	status = IB_WC_SUCCESS;
1618 
1619 	switch (opcode) {
1620 	case OP(ACKNOWLEDGE):
1621 	case OP(ATOMIC_ACKNOWLEDGE):
1622 	case OP(RDMA_READ_RESPONSE_FIRST):
1623 		aeth = be32_to_cpu(ohdr->u.aeth);
1624 		if (opcode == OP(ATOMIC_ACKNOWLEDGE))
1625 			val = ib_u64_get(&ohdr->u.at.atomic_ack_eth);
1626 		else
1627 			val = 0;
1628 		if (!do_rc_ack(qp, aeth, psn, opcode, val, rcd) ||
1629 		    opcode != OP(RDMA_READ_RESPONSE_FIRST))
1630 			goto ack_done;
1631 		wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1632 		if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1633 			goto ack_op_err;
1634 		/*
1635 		 * If this is a response to a resent RDMA read, we
1636 		 * have to be careful to copy the data to the right
1637 		 * location.
1638 		 */
1639 		qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1640 						  wqe, psn, pmtu);
1641 		goto read_middle;
1642 
1643 	case OP(RDMA_READ_RESPONSE_MIDDLE):
1644 		/* no AETH, no ACK */
1645 		if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
1646 			goto ack_seq_err;
1647 		if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1648 			goto ack_op_err;
1649 read_middle:
1650 		if (unlikely(tlen != (hdrsize + pmtu + 4)))
1651 			goto ack_len_err;
1652 		if (unlikely(pmtu >= qp->s_rdma_read_len))
1653 			goto ack_len_err;
1654 
1655 		/*
1656 		 * We got a response so update the timeout.
1657 		 * 4.096 usec. * (1 << qp->timeout)
1658 		 */
1659 		qp->s_flags |= RVT_S_TIMER;
1660 		mod_timer(&qp->s_timer, jiffies + qp->timeout_jiffies);
1661 		if (qp->s_flags & RVT_S_WAIT_ACK) {
1662 			qp->s_flags &= ~RVT_S_WAIT_ACK;
1663 			hfi1_schedule_send(qp);
1664 		}
1665 
1666 		if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
1667 			qp->s_retry = qp->s_retry_cnt;
1668 
1669 		/*
1670 		 * Update the RDMA receive state but do the copy w/o
1671 		 * holding the locks and blocking interrupts.
1672 		 */
1673 		qp->s_rdma_read_len -= pmtu;
1674 		update_last_psn(qp, psn);
1675 		spin_unlock_irqrestore(&qp->s_lock, flags);
1676 		hfi1_copy_sge(&qp->s_rdma_read_sge, data, pmtu, 0, 0);
1677 		goto bail;
1678 
1679 	case OP(RDMA_READ_RESPONSE_ONLY):
1680 		aeth = be32_to_cpu(ohdr->u.aeth);
1681 		if (!do_rc_ack(qp, aeth, psn, opcode, 0, rcd))
1682 			goto ack_done;
1683 		/* Get the number of bytes the message was padded by. */
1684 		pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1685 		/*
1686 		 * Check that the data size is >= 0 && <= pmtu.
1687 		 * Remember to account for ICRC (4).
1688 		 */
1689 		if (unlikely(tlen < (hdrsize + pad + 4)))
1690 			goto ack_len_err;
1691 		/*
1692 		 * If this is a response to a resent RDMA read, we
1693 		 * have to be careful to copy the data to the right
1694 		 * location.
1695 		 */
1696 		wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
1697 		qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1698 						  wqe, psn, pmtu);
1699 		goto read_last;
1700 
1701 	case OP(RDMA_READ_RESPONSE_LAST):
1702 		/* ACKs READ req. */
1703 		if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
1704 			goto ack_seq_err;
1705 		if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1706 			goto ack_op_err;
1707 		/* Get the number of bytes the message was padded by. */
1708 		pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1709 		/*
1710 		 * Check that the data size is >= 1 && <= pmtu.
1711 		 * Remember to account for ICRC (4).
1712 		 */
1713 		if (unlikely(tlen <= (hdrsize + pad + 4)))
1714 			goto ack_len_err;
1715 read_last:
1716 		tlen -= hdrsize + pad + 4;
1717 		if (unlikely(tlen != qp->s_rdma_read_len))
1718 			goto ack_len_err;
1719 		aeth = be32_to_cpu(ohdr->u.aeth);
1720 		hfi1_copy_sge(&qp->s_rdma_read_sge, data, tlen, 0, 0);
1721 		WARN_ON(qp->s_rdma_read_sge.num_sge);
1722 		(void)do_rc_ack(qp, aeth, psn,
1723 				 OP(RDMA_READ_RESPONSE_LAST), 0, rcd);
1724 		goto ack_done;
1725 	}
1726 
1727 ack_op_err:
1728 	status = IB_WC_LOC_QP_OP_ERR;
1729 	goto ack_err;
1730 
1731 ack_seq_err:
1732 	rdma_seq_err(qp, ibp, psn, rcd);
1733 	goto ack_done;
1734 
1735 ack_len_err:
1736 	status = IB_WC_LOC_LEN_ERR;
1737 ack_err:
1738 	if (qp->s_last == qp->s_acked) {
1739 		hfi1_send_complete(qp, wqe, status);
1740 		rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1741 	}
1742 ack_done:
1743 	spin_unlock_irqrestore(&qp->s_lock, flags);
1744 bail:
1745 	return;
1746 }
1747 
1748 static inline void rc_defered_ack(struct hfi1_ctxtdata *rcd,
1749 				  struct rvt_qp *qp)
1750 {
1751 	if (list_empty(&qp->rspwait)) {
1752 		qp->r_flags |= RVT_R_RSP_NAK;
1753 		rvt_get_qp(qp);
1754 		list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1755 	}
1756 }
1757 
1758 static inline void rc_cancel_ack(struct rvt_qp *qp)
1759 {
1760 	struct hfi1_qp_priv *priv = qp->priv;
1761 
1762 	priv->r_adefered = 0;
1763 	if (list_empty(&qp->rspwait))
1764 		return;
1765 	list_del_init(&qp->rspwait);
1766 	qp->r_flags &= ~RVT_R_RSP_NAK;
1767 	rvt_put_qp(qp);
1768 }
1769 
1770 /**
1771  * rc_rcv_error - process an incoming duplicate or error RC packet
1772  * @ohdr: the other headers for this packet
1773  * @data: the packet data
1774  * @qp: the QP for this packet
1775  * @opcode: the opcode for this packet
1776  * @psn: the packet sequence number for this packet
1777  * @diff: the difference between the PSN and the expected PSN
1778  *
1779  * This is called from hfi1_rc_rcv() to process an unexpected
1780  * incoming RC packet for the given QP.
1781  * Called at interrupt level.
1782  * Return 1 if no more processing is needed; otherwise return 0 to
1783  * schedule a response to be sent.
1784  */
1785 static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
1786 				 struct rvt_qp *qp, u32 opcode, u32 psn,
1787 				 int diff, struct hfi1_ctxtdata *rcd)
1788 {
1789 	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
1790 	struct rvt_ack_entry *e;
1791 	unsigned long flags;
1792 	u8 i, prev;
1793 	int old_req;
1794 
1795 	trace_hfi1_rcv_error(qp, psn);
1796 	if (diff > 0) {
1797 		/*
1798 		 * Packet sequence error.
1799 		 * A NAK will ACK earlier sends and RDMA writes.
1800 		 * Don't queue the NAK if we already sent one.
1801 		 */
1802 		if (!qp->r_nak_state) {
1803 			ibp->rvp.n_rc_seqnak++;
1804 			qp->r_nak_state = IB_NAK_PSN_ERROR;
1805 			/* Use the expected PSN. */
1806 			qp->r_ack_psn = qp->r_psn;
1807 			/*
1808 			 * Wait to send the sequence NAK until all packets
1809 			 * in the receive queue have been processed.
1810 			 * Otherwise, we end up propagating congestion.
1811 			 */
1812 			rc_defered_ack(rcd, qp);
1813 		}
1814 		goto done;
1815 	}
1816 
1817 	/*
1818 	 * Handle a duplicate request.  Don't re-execute SEND, RDMA
1819 	 * write or atomic op.  Don't NAK errors, just silently drop
1820 	 * the duplicate request.  Note that r_sge, r_len, and
1821 	 * r_rcv_len may be in use so don't modify them.
1822 	 *
1823 	 * We are supposed to ACK the earliest duplicate PSN but we
1824 	 * can coalesce an outstanding duplicate ACK.  We have to
1825 	 * send the earliest so that RDMA reads can be restarted at
1826 	 * the requester's expected PSN.
1827 	 *
1828 	 * First, find where this duplicate PSN falls within the
1829 	 * ACKs previously sent.
1830 	 * old_req is true if there is an older response that is scheduled
1831 	 * to be sent before sending this one.
1832 	 */
1833 	e = NULL;
1834 	old_req = 1;
1835 	ibp->rvp.n_rc_dupreq++;
1836 
1837 	spin_lock_irqsave(&qp->s_lock, flags);
1838 
1839 	for (i = qp->r_head_ack_queue; ; i = prev) {
1840 		if (i == qp->s_tail_ack_queue)
1841 			old_req = 0;
1842 		if (i)
1843 			prev = i - 1;
1844 		else
1845 			prev = HFI1_MAX_RDMA_ATOMIC;
1846 		if (prev == qp->r_head_ack_queue) {
1847 			e = NULL;
1848 			break;
1849 		}
1850 		e = &qp->s_ack_queue[prev];
1851 		if (!e->opcode) {
1852 			e = NULL;
1853 			break;
1854 		}
1855 		if (cmp_psn(psn, e->psn) >= 0) {
1856 			if (prev == qp->s_tail_ack_queue &&
1857 			    cmp_psn(psn, e->lpsn) <= 0)
1858 				old_req = 0;
1859 			break;
1860 		}
1861 	}
1862 	switch (opcode) {
1863 	case OP(RDMA_READ_REQUEST): {
1864 		struct ib_reth *reth;
1865 		u32 offset;
1866 		u32 len;
1867 
1868 		/*
1869 		 * If we didn't find the RDMA read request in the ack queue,
1870 		 * we can ignore this request.
1871 		 */
1872 		if (!e || e->opcode != OP(RDMA_READ_REQUEST))
1873 			goto unlock_done;
1874 		/* RETH comes after BTH */
1875 		reth = &ohdr->u.rc.reth;
1876 		/*
1877 		 * Address range must be a subset of the original
1878 		 * request and start on pmtu boundaries.
1879 		 * We reuse the old ack_queue slot since the requester
1880 		 * should not back up and request an earlier PSN for the
1881 		 * same request.
1882 		 */
1883 		offset = delta_psn(psn, e->psn) * qp->pmtu;
1884 		len = be32_to_cpu(reth->length);
1885 		if (unlikely(offset + len != e->rdma_sge.sge_length))
1886 			goto unlock_done;
1887 		if (e->rdma_sge.mr) {
1888 			rvt_put_mr(e->rdma_sge.mr);
1889 			e->rdma_sge.mr = NULL;
1890 		}
1891 		if (len != 0) {
1892 			u32 rkey = be32_to_cpu(reth->rkey);
1893 			u64 vaddr = get_ib_reth_vaddr(reth);
1894 			int ok;
1895 
1896 			ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey,
1897 					 IB_ACCESS_REMOTE_READ);
1898 			if (unlikely(!ok))
1899 				goto unlock_done;
1900 		} else {
1901 			e->rdma_sge.vaddr = NULL;
1902 			e->rdma_sge.length = 0;
1903 			e->rdma_sge.sge_length = 0;
1904 		}
1905 		e->psn = psn;
1906 		if (old_req)
1907 			goto unlock_done;
1908 		qp->s_tail_ack_queue = prev;
1909 		break;
1910 	}
1911 
1912 	case OP(COMPARE_SWAP):
1913 	case OP(FETCH_ADD): {
1914 		/*
1915 		 * If we didn't find the atomic request in the ack queue
1916 		 * or the send engine is already backed up to send an
1917 		 * earlier entry, we can ignore this request.
1918 		 */
1919 		if (!e || e->opcode != (u8)opcode || old_req)
1920 			goto unlock_done;
1921 		qp->s_tail_ack_queue = prev;
1922 		break;
1923 	}
1924 
1925 	default:
1926 		/*
1927 		 * Ignore this operation if it doesn't request an ACK
1928 		 * or an earlier RDMA read or atomic is going to be resent.
1929 		 */
1930 		if (!(psn & IB_BTH_REQ_ACK) || old_req)
1931 			goto unlock_done;
1932 		/*
1933 		 * Resend the most recent ACK if this request is
1934 		 * after all the previous RDMA reads and atomics.
1935 		 */
1936 		if (i == qp->r_head_ack_queue) {
1937 			spin_unlock_irqrestore(&qp->s_lock, flags);
1938 			qp->r_nak_state = 0;
1939 			qp->r_ack_psn = qp->r_psn - 1;
1940 			goto send_ack;
1941 		}
1942 
1943 		/*
1944 		 * Resend the RDMA read or atomic op which
1945 		 * ACKs this duplicate request.
1946 		 */
1947 		qp->s_tail_ack_queue = i;
1948 		break;
1949 	}
1950 	qp->s_ack_state = OP(ACKNOWLEDGE);
1951 	qp->s_flags |= RVT_S_RESP_PENDING;
1952 	qp->r_nak_state = 0;
1953 	hfi1_schedule_send(qp);
1954 
1955 unlock_done:
1956 	spin_unlock_irqrestore(&qp->s_lock, flags);
1957 done:
1958 	return 1;
1959 
1960 send_ack:
1961 	return 0;
1962 }
1963 
1964 void hfi1_rc_error(struct rvt_qp *qp, enum ib_wc_status err)
1965 {
1966 	unsigned long flags;
1967 	int lastwqe;
1968 
1969 	spin_lock_irqsave(&qp->s_lock, flags);
1970 	lastwqe = rvt_error_qp(qp, err);
1971 	spin_unlock_irqrestore(&qp->s_lock, flags);
1972 
1973 	if (lastwqe) {
1974 		struct ib_event ev;
1975 
1976 		ev.device = qp->ibqp.device;
1977 		ev.element.qp = &qp->ibqp;
1978 		ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
1979 		qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
1980 	}
1981 }
1982 
1983 static inline void update_ack_queue(struct rvt_qp *qp, unsigned n)
1984 {
1985 	unsigned next;
1986 
1987 	next = n + 1;
1988 	if (next > HFI1_MAX_RDMA_ATOMIC)
1989 		next = 0;
1990 	qp->s_tail_ack_queue = next;
1991 	qp->s_ack_state = OP(ACKNOWLEDGE);
1992 }
1993 
1994 static void log_cca_event(struct hfi1_pportdata *ppd, u8 sl, u32 rlid,
1995 			  u32 lqpn, u32 rqpn, u8 svc_type)
1996 {
1997 	struct opa_hfi1_cong_log_event_internal *cc_event;
1998 	unsigned long flags;
1999 
2000 	if (sl >= OPA_MAX_SLS)
2001 		return;
2002 
2003 	spin_lock_irqsave(&ppd->cc_log_lock, flags);
2004 
2005 	ppd->threshold_cong_event_map[sl / 8] |= 1 << (sl % 8);
2006 	ppd->threshold_event_counter++;
2007 
2008 	cc_event = &ppd->cc_events[ppd->cc_log_idx++];
2009 	if (ppd->cc_log_idx == OPA_CONG_LOG_ELEMS)
2010 		ppd->cc_log_idx = 0;
2011 	cc_event->lqpn = lqpn & RVT_QPN_MASK;
2012 	cc_event->rqpn = rqpn & RVT_QPN_MASK;
2013 	cc_event->sl = sl;
2014 	cc_event->svc_type = svc_type;
2015 	cc_event->rlid = rlid;
2016 	/* keep timestamp in units of 1.024 usec */
2017 	cc_event->timestamp = ktime_to_ns(ktime_get()) / 1024;
2018 
2019 	spin_unlock_irqrestore(&ppd->cc_log_lock, flags);
2020 }
2021 
2022 void process_becn(struct hfi1_pportdata *ppd, u8 sl, u16 rlid, u32 lqpn,
2023 		  u32 rqpn, u8 svc_type)
2024 {
2025 	struct cca_timer *cca_timer;
2026 	u16 ccti, ccti_incr, ccti_timer, ccti_limit;
2027 	u8 trigger_threshold;
2028 	struct cc_state *cc_state;
2029 	unsigned long flags;
2030 
2031 	if (sl >= OPA_MAX_SLS)
2032 		return;
2033 
2034 	cc_state = get_cc_state(ppd);
2035 
2036 	if (!cc_state)
2037 		return;
2038 
2039 	/*
2040 	 * 1) increase CCTI (for this SL)
2041 	 * 2) select IPG (i.e., call set_link_ipg())
2042 	 * 3) start timer
2043 	 */
2044 	ccti_limit = cc_state->cct.ccti_limit;
2045 	ccti_incr = cc_state->cong_setting.entries[sl].ccti_increase;
2046 	ccti_timer = cc_state->cong_setting.entries[sl].ccti_timer;
2047 	trigger_threshold =
2048 		cc_state->cong_setting.entries[sl].trigger_threshold;
2049 
2050 	spin_lock_irqsave(&ppd->cca_timer_lock, flags);
2051 
2052 	cca_timer = &ppd->cca_timer[sl];
2053 	if (cca_timer->ccti < ccti_limit) {
2054 		if (cca_timer->ccti + ccti_incr <= ccti_limit)
2055 			cca_timer->ccti += ccti_incr;
2056 		else
2057 			cca_timer->ccti = ccti_limit;
2058 		set_link_ipg(ppd);
2059 	}
2060 
2061 	ccti = cca_timer->ccti;
2062 
2063 	if (!hrtimer_active(&cca_timer->hrtimer)) {
2064 		/* ccti_timer is in units of 1.024 usec */
2065 		unsigned long nsec = 1024 * ccti_timer;
2066 
2067 		hrtimer_start(&cca_timer->hrtimer, ns_to_ktime(nsec),
2068 			      HRTIMER_MODE_REL);
2069 	}
2070 
2071 	spin_unlock_irqrestore(&ppd->cca_timer_lock, flags);
2072 
2073 	if ((trigger_threshold != 0) && (ccti >= trigger_threshold))
2074 		log_cca_event(ppd, sl, rlid, lqpn, rqpn, svc_type);
2075 }
2076 
2077 /**
2078  * hfi1_rc_rcv - process an incoming RC packet
2079  * @rcd: the context pointer
2080  * @hdr: the header of this packet
2081  * @rcv_flags: flags relevant to rcv processing
2082  * @data: the packet data
2083  * @tlen: the packet length
2084  * @qp: the QP for this packet
2085  *
2086  * This is called from qp_rcv() to process an incoming RC packet
2087  * for the given QP.
2088  * May be called at interrupt level.
2089  */
2090 void hfi1_rc_rcv(struct hfi1_packet *packet)
2091 {
2092 	struct hfi1_ctxtdata *rcd = packet->rcd;
2093 	struct ib_header *hdr = packet->hdr;
2094 	u32 rcv_flags = packet->rcv_flags;
2095 	void *data = packet->ebuf;
2096 	u32 tlen = packet->tlen;
2097 	struct rvt_qp *qp = packet->qp;
2098 	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
2099 	struct ib_other_headers *ohdr = packet->ohdr;
2100 	u32 bth0, opcode;
2101 	u32 hdrsize = packet->hlen;
2102 	u32 psn;
2103 	u32 pad;
2104 	struct ib_wc wc;
2105 	u32 pmtu = qp->pmtu;
2106 	int diff;
2107 	struct ib_reth *reth;
2108 	unsigned long flags;
2109 	int ret, is_fecn = 0;
2110 	int copy_last = 0;
2111 	u32 rkey;
2112 
2113 	lockdep_assert_held(&qp->r_lock);
2114 	bth0 = be32_to_cpu(ohdr->bth[0]);
2115 	if (hfi1_ruc_check_hdr(ibp, hdr, rcv_flags & HFI1_HAS_GRH, qp, bth0))
2116 		return;
2117 
2118 	is_fecn = process_ecn(qp, packet, false);
2119 
2120 	psn = be32_to_cpu(ohdr->bth[2]);
2121 	opcode = (bth0 >> 24) & 0xff;
2122 
2123 	/*
2124 	 * Process responses (ACKs) before anything else.  Note that the
2125 	 * packet sequence number will be for something in the send work
2126 	 * queue rather than the expected receive packet sequence number.
2127 	 * In other words, this QP is the requester.
2128 	 */
2129 	if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
2130 	    opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
2131 		rc_rcv_resp(ibp, ohdr, data, tlen, qp, opcode, psn,
2132 			    hdrsize, pmtu, rcd);
2133 		if (is_fecn)
2134 			goto send_ack;
2135 		return;
2136 	}
2137 
2138 	/* Compute 24 bits worth of difference. */
2139 	diff = delta_psn(psn, qp->r_psn);
2140 	if (unlikely(diff)) {
2141 		if (rc_rcv_error(ohdr, data, qp, opcode, psn, diff, rcd))
2142 			return;
2143 		goto send_ack;
2144 	}
2145 
2146 	/* Check for opcode sequence errors. */
2147 	switch (qp->r_state) {
2148 	case OP(SEND_FIRST):
2149 	case OP(SEND_MIDDLE):
2150 		if (opcode == OP(SEND_MIDDLE) ||
2151 		    opcode == OP(SEND_LAST) ||
2152 		    opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2153 		    opcode == OP(SEND_LAST_WITH_INVALIDATE))
2154 			break;
2155 		goto nack_inv;
2156 
2157 	case OP(RDMA_WRITE_FIRST):
2158 	case OP(RDMA_WRITE_MIDDLE):
2159 		if (opcode == OP(RDMA_WRITE_MIDDLE) ||
2160 		    opcode == OP(RDMA_WRITE_LAST) ||
2161 		    opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2162 			break;
2163 		goto nack_inv;
2164 
2165 	default:
2166 		if (opcode == OP(SEND_MIDDLE) ||
2167 		    opcode == OP(SEND_LAST) ||
2168 		    opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
2169 		    opcode == OP(SEND_LAST_WITH_INVALIDATE) ||
2170 		    opcode == OP(RDMA_WRITE_MIDDLE) ||
2171 		    opcode == OP(RDMA_WRITE_LAST) ||
2172 		    opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
2173 			goto nack_inv;
2174 		/*
2175 		 * Note that it is up to the requester to not send a new
2176 		 * RDMA read or atomic operation before receiving an ACK
2177 		 * for the previous operation.
2178 		 */
2179 		break;
2180 	}
2181 
2182 	if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
2183 		qp_comm_est(qp);
2184 
2185 	/* OK, process the packet. */
2186 	switch (opcode) {
2187 	case OP(SEND_FIRST):
2188 		ret = hfi1_rvt_get_rwqe(qp, 0);
2189 		if (ret < 0)
2190 			goto nack_op_err;
2191 		if (!ret)
2192 			goto rnr_nak;
2193 		qp->r_rcv_len = 0;
2194 		/* FALLTHROUGH */
2195 	case OP(SEND_MIDDLE):
2196 	case OP(RDMA_WRITE_MIDDLE):
2197 send_middle:
2198 		/* Check for invalid length PMTU or posted rwqe len. */
2199 		if (unlikely(tlen != (hdrsize + pmtu + 4)))
2200 			goto nack_inv;
2201 		qp->r_rcv_len += pmtu;
2202 		if (unlikely(qp->r_rcv_len > qp->r_len))
2203 			goto nack_inv;
2204 		hfi1_copy_sge(&qp->r_sge, data, pmtu, 1, 0);
2205 		break;
2206 
2207 	case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
2208 		/* consume RWQE */
2209 		ret = hfi1_rvt_get_rwqe(qp, 1);
2210 		if (ret < 0)
2211 			goto nack_op_err;
2212 		if (!ret)
2213 			goto rnr_nak;
2214 		goto send_last_imm;
2215 
2216 	case OP(SEND_ONLY):
2217 	case OP(SEND_ONLY_WITH_IMMEDIATE):
2218 	case OP(SEND_ONLY_WITH_INVALIDATE):
2219 		ret = hfi1_rvt_get_rwqe(qp, 0);
2220 		if (ret < 0)
2221 			goto nack_op_err;
2222 		if (!ret)
2223 			goto rnr_nak;
2224 		qp->r_rcv_len = 0;
2225 		if (opcode == OP(SEND_ONLY))
2226 			goto no_immediate_data;
2227 		if (opcode == OP(SEND_ONLY_WITH_INVALIDATE))
2228 			goto send_last_inv;
2229 		/* FALLTHROUGH for SEND_ONLY_WITH_IMMEDIATE */
2230 	case OP(SEND_LAST_WITH_IMMEDIATE):
2231 send_last_imm:
2232 		wc.ex.imm_data = ohdr->u.imm_data;
2233 		wc.wc_flags = IB_WC_WITH_IMM;
2234 		goto send_last;
2235 	case OP(SEND_LAST_WITH_INVALIDATE):
2236 send_last_inv:
2237 		rkey = be32_to_cpu(ohdr->u.ieth);
2238 		if (rvt_invalidate_rkey(qp, rkey))
2239 			goto no_immediate_data;
2240 		wc.ex.invalidate_rkey = rkey;
2241 		wc.wc_flags = IB_WC_WITH_INVALIDATE;
2242 		goto send_last;
2243 	case OP(RDMA_WRITE_LAST):
2244 		copy_last = ibpd_to_rvtpd(qp->ibqp.pd)->user;
2245 		/* fall through */
2246 	case OP(SEND_LAST):
2247 no_immediate_data:
2248 		wc.wc_flags = 0;
2249 		wc.ex.imm_data = 0;
2250 send_last:
2251 		/* Get the number of bytes the message was padded by. */
2252 		pad = (bth0 >> 20) & 3;
2253 		/* Check for invalid length. */
2254 		/* LAST len should be >= 1 */
2255 		if (unlikely(tlen < (hdrsize + pad + 4)))
2256 			goto nack_inv;
2257 		/* Don't count the CRC. */
2258 		tlen -= (hdrsize + pad + 4);
2259 		wc.byte_len = tlen + qp->r_rcv_len;
2260 		if (unlikely(wc.byte_len > qp->r_len))
2261 			goto nack_inv;
2262 		hfi1_copy_sge(&qp->r_sge, data, tlen, 1, copy_last);
2263 		rvt_put_ss(&qp->r_sge);
2264 		qp->r_msn++;
2265 		if (!__test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
2266 			break;
2267 		wc.wr_id = qp->r_wr_id;
2268 		wc.status = IB_WC_SUCCESS;
2269 		if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
2270 		    opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
2271 			wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
2272 		else
2273 			wc.opcode = IB_WC_RECV;
2274 		wc.qp = &qp->ibqp;
2275 		wc.src_qp = qp->remote_qpn;
2276 		wc.slid = qp->remote_ah_attr.dlid;
2277 		/*
2278 		 * It seems that IB mandates the presence of an SL in a
2279 		 * work completion only for the UD transport (see section
2280 		 * 11.4.2 of IBTA Vol. 1).
2281 		 *
2282 		 * However, the way the SL is chosen below is consistent
2283 		 * with the way that IB/qib works and is trying avoid
2284 		 * introducing incompatibilities.
2285 		 *
2286 		 * See also OPA Vol. 1, section 9.7.6, and table 9-17.
2287 		 */
2288 		wc.sl = qp->remote_ah_attr.sl;
2289 		/* zero fields that are N/A */
2290 		wc.vendor_err = 0;
2291 		wc.pkey_index = 0;
2292 		wc.dlid_path_bits = 0;
2293 		wc.port_num = 0;
2294 		/* Signal completion event if the solicited bit is set. */
2295 		rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
2296 			     (bth0 & IB_BTH_SOLICITED) != 0);
2297 		break;
2298 
2299 	case OP(RDMA_WRITE_ONLY):
2300 		copy_last = 1;
2301 		/* fall through */
2302 	case OP(RDMA_WRITE_FIRST):
2303 	case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
2304 		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
2305 			goto nack_inv;
2306 		/* consume RWQE */
2307 		reth = &ohdr->u.rc.reth;
2308 		qp->r_len = be32_to_cpu(reth->length);
2309 		qp->r_rcv_len = 0;
2310 		qp->r_sge.sg_list = NULL;
2311 		if (qp->r_len != 0) {
2312 			u32 rkey = be32_to_cpu(reth->rkey);
2313 			u64 vaddr = get_ib_reth_vaddr(reth);
2314 			int ok;
2315 
2316 			/* Check rkey & NAK */
2317 			ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len, vaddr,
2318 					 rkey, IB_ACCESS_REMOTE_WRITE);
2319 			if (unlikely(!ok))
2320 				goto nack_acc;
2321 			qp->r_sge.num_sge = 1;
2322 		} else {
2323 			qp->r_sge.num_sge = 0;
2324 			qp->r_sge.sge.mr = NULL;
2325 			qp->r_sge.sge.vaddr = NULL;
2326 			qp->r_sge.sge.length = 0;
2327 			qp->r_sge.sge.sge_length = 0;
2328 		}
2329 		if (opcode == OP(RDMA_WRITE_FIRST))
2330 			goto send_middle;
2331 		else if (opcode == OP(RDMA_WRITE_ONLY))
2332 			goto no_immediate_data;
2333 		ret = hfi1_rvt_get_rwqe(qp, 1);
2334 		if (ret < 0)
2335 			goto nack_op_err;
2336 		if (!ret)
2337 			goto rnr_nak;
2338 		wc.ex.imm_data = ohdr->u.rc.imm_data;
2339 		wc.wc_flags = IB_WC_WITH_IMM;
2340 		goto send_last;
2341 
2342 	case OP(RDMA_READ_REQUEST): {
2343 		struct rvt_ack_entry *e;
2344 		u32 len;
2345 		u8 next;
2346 
2347 		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
2348 			goto nack_inv;
2349 		next = qp->r_head_ack_queue + 1;
2350 		/* s_ack_queue is size HFI1_MAX_RDMA_ATOMIC+1 so use > not >= */
2351 		if (next > HFI1_MAX_RDMA_ATOMIC)
2352 			next = 0;
2353 		spin_lock_irqsave(&qp->s_lock, flags);
2354 		if (unlikely(next == qp->s_tail_ack_queue)) {
2355 			if (!qp->s_ack_queue[next].sent)
2356 				goto nack_inv_unlck;
2357 			update_ack_queue(qp, next);
2358 		}
2359 		e = &qp->s_ack_queue[qp->r_head_ack_queue];
2360 		if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
2361 			rvt_put_mr(e->rdma_sge.mr);
2362 			e->rdma_sge.mr = NULL;
2363 		}
2364 		reth = &ohdr->u.rc.reth;
2365 		len = be32_to_cpu(reth->length);
2366 		if (len) {
2367 			u32 rkey = be32_to_cpu(reth->rkey);
2368 			u64 vaddr = get_ib_reth_vaddr(reth);
2369 			int ok;
2370 
2371 			/* Check rkey & NAK */
2372 			ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr,
2373 					 rkey, IB_ACCESS_REMOTE_READ);
2374 			if (unlikely(!ok))
2375 				goto nack_acc_unlck;
2376 			/*
2377 			 * Update the next expected PSN.  We add 1 later
2378 			 * below, so only add the remainder here.
2379 			 */
2380 			qp->r_psn += rvt_div_mtu(qp, len - 1);
2381 		} else {
2382 			e->rdma_sge.mr = NULL;
2383 			e->rdma_sge.vaddr = NULL;
2384 			e->rdma_sge.length = 0;
2385 			e->rdma_sge.sge_length = 0;
2386 		}
2387 		e->opcode = opcode;
2388 		e->sent = 0;
2389 		e->psn = psn;
2390 		e->lpsn = qp->r_psn;
2391 		/*
2392 		 * We need to increment the MSN here instead of when we
2393 		 * finish sending the result since a duplicate request would
2394 		 * increment it more than once.
2395 		 */
2396 		qp->r_msn++;
2397 		qp->r_psn++;
2398 		qp->r_state = opcode;
2399 		qp->r_nak_state = 0;
2400 		qp->r_head_ack_queue = next;
2401 
2402 		/* Schedule the send engine. */
2403 		qp->s_flags |= RVT_S_RESP_PENDING;
2404 		hfi1_schedule_send(qp);
2405 
2406 		spin_unlock_irqrestore(&qp->s_lock, flags);
2407 		if (is_fecn)
2408 			goto send_ack;
2409 		return;
2410 	}
2411 
2412 	case OP(COMPARE_SWAP):
2413 	case OP(FETCH_ADD): {
2414 		struct ib_atomic_eth *ateth;
2415 		struct rvt_ack_entry *e;
2416 		u64 vaddr;
2417 		atomic64_t *maddr;
2418 		u64 sdata;
2419 		u32 rkey;
2420 		u8 next;
2421 
2422 		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
2423 			goto nack_inv;
2424 		next = qp->r_head_ack_queue + 1;
2425 		if (next > HFI1_MAX_RDMA_ATOMIC)
2426 			next = 0;
2427 		spin_lock_irqsave(&qp->s_lock, flags);
2428 		if (unlikely(next == qp->s_tail_ack_queue)) {
2429 			if (!qp->s_ack_queue[next].sent)
2430 				goto nack_inv_unlck;
2431 			update_ack_queue(qp, next);
2432 		}
2433 		e = &qp->s_ack_queue[qp->r_head_ack_queue];
2434 		if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
2435 			rvt_put_mr(e->rdma_sge.mr);
2436 			e->rdma_sge.mr = NULL;
2437 		}
2438 		ateth = &ohdr->u.atomic_eth;
2439 		vaddr = get_ib_ateth_vaddr(ateth);
2440 		if (unlikely(vaddr & (sizeof(u64) - 1)))
2441 			goto nack_inv_unlck;
2442 		rkey = be32_to_cpu(ateth->rkey);
2443 		/* Check rkey & NAK */
2444 		if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
2445 					  vaddr, rkey,
2446 					  IB_ACCESS_REMOTE_ATOMIC)))
2447 			goto nack_acc_unlck;
2448 		/* Perform atomic OP and save result. */
2449 		maddr = (atomic64_t *)qp->r_sge.sge.vaddr;
2450 		sdata = get_ib_ateth_swap(ateth);
2451 		e->atomic_data = (opcode == OP(FETCH_ADD)) ?
2452 			(u64)atomic64_add_return(sdata, maddr) - sdata :
2453 			(u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr,
2454 				      get_ib_ateth_compare(ateth),
2455 				      sdata);
2456 		rvt_put_mr(qp->r_sge.sge.mr);
2457 		qp->r_sge.num_sge = 0;
2458 		e->opcode = opcode;
2459 		e->sent = 0;
2460 		e->psn = psn;
2461 		e->lpsn = psn;
2462 		qp->r_msn++;
2463 		qp->r_psn++;
2464 		qp->r_state = opcode;
2465 		qp->r_nak_state = 0;
2466 		qp->r_head_ack_queue = next;
2467 
2468 		/* Schedule the send engine. */
2469 		qp->s_flags |= RVT_S_RESP_PENDING;
2470 		hfi1_schedule_send(qp);
2471 
2472 		spin_unlock_irqrestore(&qp->s_lock, flags);
2473 		if (is_fecn)
2474 			goto send_ack;
2475 		return;
2476 	}
2477 
2478 	default:
2479 		/* NAK unknown opcodes. */
2480 		goto nack_inv;
2481 	}
2482 	qp->r_psn++;
2483 	qp->r_state = opcode;
2484 	qp->r_ack_psn = psn;
2485 	qp->r_nak_state = 0;
2486 	/* Send an ACK if requested or required. */
2487 	if (psn & IB_BTH_REQ_ACK) {
2488 		struct hfi1_qp_priv *priv = qp->priv;
2489 
2490 		if (packet->numpkt == 0) {
2491 			rc_cancel_ack(qp);
2492 			goto send_ack;
2493 		}
2494 		if (priv->r_adefered >= HFI1_PSN_CREDIT) {
2495 			rc_cancel_ack(qp);
2496 			goto send_ack;
2497 		}
2498 		if (unlikely(is_fecn)) {
2499 			rc_cancel_ack(qp);
2500 			goto send_ack;
2501 		}
2502 		priv->r_adefered++;
2503 		rc_defered_ack(rcd, qp);
2504 	}
2505 	return;
2506 
2507 rnr_nak:
2508 	qp->r_nak_state = qp->r_min_rnr_timer | IB_RNR_NAK;
2509 	qp->r_ack_psn = qp->r_psn;
2510 	/* Queue RNR NAK for later */
2511 	rc_defered_ack(rcd, qp);
2512 	return;
2513 
2514 nack_op_err:
2515 	hfi1_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
2516 	qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR;
2517 	qp->r_ack_psn = qp->r_psn;
2518 	/* Queue NAK for later */
2519 	rc_defered_ack(rcd, qp);
2520 	return;
2521 
2522 nack_inv_unlck:
2523 	spin_unlock_irqrestore(&qp->s_lock, flags);
2524 nack_inv:
2525 	hfi1_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
2526 	qp->r_nak_state = IB_NAK_INVALID_REQUEST;
2527 	qp->r_ack_psn = qp->r_psn;
2528 	/* Queue NAK for later */
2529 	rc_defered_ack(rcd, qp);
2530 	return;
2531 
2532 nack_acc_unlck:
2533 	spin_unlock_irqrestore(&qp->s_lock, flags);
2534 nack_acc:
2535 	hfi1_rc_error(qp, IB_WC_LOC_PROT_ERR);
2536 	qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
2537 	qp->r_ack_psn = qp->r_psn;
2538 send_ack:
2539 	hfi1_send_rc_ack(rcd, qp, is_fecn);
2540 }
2541 
2542 void hfi1_rc_hdrerr(
2543 	struct hfi1_ctxtdata *rcd,
2544 	struct ib_header *hdr,
2545 	u32 rcv_flags,
2546 	struct rvt_qp *qp)
2547 {
2548 	int has_grh = rcv_flags & HFI1_HAS_GRH;
2549 	struct ib_other_headers *ohdr;
2550 	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
2551 	int diff;
2552 	u32 opcode;
2553 	u32 psn, bth0;
2554 
2555 	/* Check for GRH */
2556 	ohdr = &hdr->u.oth;
2557 	if (has_grh)
2558 		ohdr = &hdr->u.l.oth;
2559 
2560 	bth0 = be32_to_cpu(ohdr->bth[0]);
2561 	if (hfi1_ruc_check_hdr(ibp, hdr, has_grh, qp, bth0))
2562 		return;
2563 
2564 	psn = be32_to_cpu(ohdr->bth[2]);
2565 	opcode = (bth0 >> 24) & 0xff;
2566 
2567 	/* Only deal with RDMA Writes for now */
2568 	if (opcode < IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) {
2569 		diff = delta_psn(psn, qp->r_psn);
2570 		if (!qp->r_nak_state && diff >= 0) {
2571 			ibp->rvp.n_rc_seqnak++;
2572 			qp->r_nak_state = IB_NAK_PSN_ERROR;
2573 			/* Use the expected PSN. */
2574 			qp->r_ack_psn = qp->r_psn;
2575 			/*
2576 			 * Wait to send the sequence
2577 			 * NAK until all packets
2578 			 * in the receive queue have
2579 			 * been processed.
2580 			 * Otherwise, we end up
2581 			 * propagating congestion.
2582 			 */
2583 			rc_defered_ack(rcd, qp);
2584 		} /* Out of sequence NAK */
2585 	} /* QP Request NAKs */
2586 }
2587