xref: /openbmc/linux/drivers/infiniband/hw/hfi1/uc.c (revision 75020f2d)
1 /*
2  * Copyright(c) 2015 - 2018 Intel Corporation.
3  *
4  * This file is provided under a dual BSD/GPLv2 license.  When using or
5  * redistributing this file, you may do so under either license.
6  *
7  * GPL LICENSE SUMMARY
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of version 2 of the GNU General Public License as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * BSD LICENSE
19  *
20  * Redistribution and use in source and binary forms, with or without
21  * modification, are permitted provided that the following conditions
22  * are met:
23  *
24  *  - Redistributions of source code must retain the above copyright
25  *    notice, this list of conditions and the following disclaimer.
26  *  - Redistributions in binary form must reproduce the above copyright
27  *    notice, this list of conditions and the following disclaimer in
28  *    the documentation and/or other materials provided with the
29  *    distribution.
30  *  - Neither the name of Intel Corporation nor the names of its
31  *    contributors may be used to endorse or promote products derived
32  *    from this software without specific prior written permission.
33  *
34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
45  *
46  */
47 
48 #include "hfi.h"
49 #include "verbs_txreq.h"
50 #include "qp.h"
51 
52 /* cut down ridiculously long IB macro names */
53 #define OP(x) UC_OP(x)
54 
55 /**
56  * hfi1_make_uc_req - construct a request packet (SEND, RDMA write)
57  * @qp: a pointer to the QP
58  * @ps: the current packet state
59  *
60  * Assume s_lock is held.
61  *
62  * Return 1 if constructed; otherwise, return 0.
63  */
64 int hfi1_make_uc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
65 {
66 	struct hfi1_qp_priv *priv = qp->priv;
67 	struct ib_other_headers *ohdr;
68 	struct rvt_swqe *wqe;
69 	u32 hwords;
70 	u32 bth0 = 0;
71 	u32 len;
72 	u32 pmtu = qp->pmtu;
73 	int middle = 0;
74 
75 	ps->s_txreq = get_txreq(ps->dev, qp);
76 	if (!ps->s_txreq)
77 		goto bail_no_tx;
78 
79 	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
80 		if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
81 			goto bail;
82 		/* We are in the error state, flush the work request. */
83 		if (qp->s_last == READ_ONCE(qp->s_head))
84 			goto bail;
85 		/* If DMAs are in progress, we can't flush immediately. */
86 		if (iowait_sdma_pending(&priv->s_iowait)) {
87 			qp->s_flags |= RVT_S_WAIT_DMA;
88 			goto bail;
89 		}
90 		clear_ahg(qp);
91 		wqe = rvt_get_swqe_ptr(qp, qp->s_last);
92 		rvt_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
93 		goto done_free_tx;
94 	}
95 
96 	if (priv->hdr_type == HFI1_PKT_TYPE_9B) {
97 		/* header size in 32-bit words LRH+BTH = (8+12)/4. */
98 		hwords = 5;
99 		if (rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)
100 			ohdr = &ps->s_txreq->phdr.hdr.ibh.u.l.oth;
101 		else
102 			ohdr = &ps->s_txreq->phdr.hdr.ibh.u.oth;
103 	} else {
104 		/* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
105 		hwords = 7;
106 		if ((rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
107 		    (hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))))
108 			ohdr = &ps->s_txreq->phdr.hdr.opah.u.l.oth;
109 		else
110 			ohdr = &ps->s_txreq->phdr.hdr.opah.u.oth;
111 	}
112 
113 	/* Get the next send request. */
114 	wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
115 	qp->s_wqe = NULL;
116 	switch (qp->s_state) {
117 	default:
118 		if (!(ib_rvt_state_ops[qp->state] &
119 		    RVT_PROCESS_NEXT_SEND_OK))
120 			goto bail;
121 		/* Check if send work queue is empty. */
122 		if (qp->s_cur == READ_ONCE(qp->s_head)) {
123 			clear_ahg(qp);
124 			goto bail;
125 		}
126 		/*
127 		 * Local operations are processed immediately
128 		 * after all prior requests have completed.
129 		 */
130 		if (wqe->wr.opcode == IB_WR_REG_MR ||
131 		    wqe->wr.opcode == IB_WR_LOCAL_INV) {
132 			int local_ops = 0;
133 			int err = 0;
134 
135 			if (qp->s_last != qp->s_cur)
136 				goto bail;
137 			if (++qp->s_cur == qp->s_size)
138 				qp->s_cur = 0;
139 			if (!(wqe->wr.send_flags & RVT_SEND_COMPLETION_ONLY)) {
140 				err = rvt_invalidate_rkey(
141 					qp, wqe->wr.ex.invalidate_rkey);
142 				local_ops = 1;
143 			}
144 			rvt_send_complete(qp, wqe, err ? IB_WC_LOC_PROT_ERR
145 							: IB_WC_SUCCESS);
146 			if (local_ops)
147 				atomic_dec(&qp->local_ops_pending);
148 			goto done_free_tx;
149 		}
150 		/*
151 		 * Start a new request.
152 		 */
153 		qp->s_psn = wqe->psn;
154 		qp->s_sge.sge = wqe->sg_list[0];
155 		qp->s_sge.sg_list = wqe->sg_list + 1;
156 		qp->s_sge.num_sge = wqe->wr.num_sge;
157 		qp->s_sge.total_len = wqe->length;
158 		len = wqe->length;
159 		qp->s_len = len;
160 		switch (wqe->wr.opcode) {
161 		case IB_WR_SEND:
162 		case IB_WR_SEND_WITH_IMM:
163 			if (len > pmtu) {
164 				qp->s_state = OP(SEND_FIRST);
165 				len = pmtu;
166 				break;
167 			}
168 			if (wqe->wr.opcode == IB_WR_SEND) {
169 				qp->s_state = OP(SEND_ONLY);
170 			} else {
171 				qp->s_state =
172 					OP(SEND_ONLY_WITH_IMMEDIATE);
173 				/* Immediate data comes after the BTH */
174 				ohdr->u.imm_data = wqe->wr.ex.imm_data;
175 				hwords += 1;
176 			}
177 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
178 				bth0 |= IB_BTH_SOLICITED;
179 			qp->s_wqe = wqe;
180 			if (++qp->s_cur >= qp->s_size)
181 				qp->s_cur = 0;
182 			break;
183 
184 		case IB_WR_RDMA_WRITE:
185 		case IB_WR_RDMA_WRITE_WITH_IMM:
186 			ohdr->u.rc.reth.vaddr =
187 				cpu_to_be64(wqe->rdma_wr.remote_addr);
188 			ohdr->u.rc.reth.rkey =
189 				cpu_to_be32(wqe->rdma_wr.rkey);
190 			ohdr->u.rc.reth.length = cpu_to_be32(len);
191 			hwords += sizeof(struct ib_reth) / 4;
192 			if (len > pmtu) {
193 				qp->s_state = OP(RDMA_WRITE_FIRST);
194 				len = pmtu;
195 				break;
196 			}
197 			if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
198 				qp->s_state = OP(RDMA_WRITE_ONLY);
199 			} else {
200 				qp->s_state =
201 					OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
202 				/* Immediate data comes after the RETH */
203 				ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
204 				hwords += 1;
205 				if (wqe->wr.send_flags & IB_SEND_SOLICITED)
206 					bth0 |= IB_BTH_SOLICITED;
207 			}
208 			qp->s_wqe = wqe;
209 			if (++qp->s_cur >= qp->s_size)
210 				qp->s_cur = 0;
211 			break;
212 
213 		default:
214 			goto bail;
215 		}
216 		break;
217 
218 	case OP(SEND_FIRST):
219 		qp->s_state = OP(SEND_MIDDLE);
220 		fallthrough;
221 	case OP(SEND_MIDDLE):
222 		len = qp->s_len;
223 		if (len > pmtu) {
224 			len = pmtu;
225 			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
226 			break;
227 		}
228 		if (wqe->wr.opcode == IB_WR_SEND) {
229 			qp->s_state = OP(SEND_LAST);
230 		} else {
231 			qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
232 			/* Immediate data comes after the BTH */
233 			ohdr->u.imm_data = wqe->wr.ex.imm_data;
234 			hwords += 1;
235 		}
236 		if (wqe->wr.send_flags & IB_SEND_SOLICITED)
237 			bth0 |= IB_BTH_SOLICITED;
238 		qp->s_wqe = wqe;
239 		if (++qp->s_cur >= qp->s_size)
240 			qp->s_cur = 0;
241 		break;
242 
243 	case OP(RDMA_WRITE_FIRST):
244 		qp->s_state = OP(RDMA_WRITE_MIDDLE);
245 		fallthrough;
246 	case OP(RDMA_WRITE_MIDDLE):
247 		len = qp->s_len;
248 		if (len > pmtu) {
249 			len = pmtu;
250 			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
251 			break;
252 		}
253 		if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
254 			qp->s_state = OP(RDMA_WRITE_LAST);
255 		} else {
256 			qp->s_state =
257 				OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
258 			/* Immediate data comes after the BTH */
259 			ohdr->u.imm_data = wqe->wr.ex.imm_data;
260 			hwords += 1;
261 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
262 				bth0 |= IB_BTH_SOLICITED;
263 		}
264 		qp->s_wqe = wqe;
265 		if (++qp->s_cur >= qp->s_size)
266 			qp->s_cur = 0;
267 		break;
268 	}
269 	qp->s_len -= len;
270 	ps->s_txreq->hdr_dwords = hwords;
271 	ps->s_txreq->sde = priv->s_sde;
272 	ps->s_txreq->ss = &qp->s_sge;
273 	ps->s_txreq->s_cur_size = len;
274 	hfi1_make_ruc_header(qp, ohdr, bth0 | (qp->s_state << 24),
275 			     qp->remote_qpn, mask_psn(qp->s_psn++),
276 			     middle, ps);
277 	return 1;
278 
279 done_free_tx:
280 	hfi1_put_txreq(ps->s_txreq);
281 	ps->s_txreq = NULL;
282 	return 1;
283 
284 bail:
285 	hfi1_put_txreq(ps->s_txreq);
286 
287 bail_no_tx:
288 	ps->s_txreq = NULL;
289 	qp->s_flags &= ~RVT_S_BUSY;
290 	return 0;
291 }
292 
293 /**
294  * hfi1_uc_rcv - handle an incoming UC packet
295  * @packet: the packet structure
296  *
297  * This is called from qp_rcv() to process an incoming UC packet
298  * for the given QP.
299  * Called at interrupt level.
300  */
301 void hfi1_uc_rcv(struct hfi1_packet *packet)
302 {
303 	struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
304 	void *data = packet->payload;
305 	u32 tlen = packet->tlen;
306 	struct rvt_qp *qp = packet->qp;
307 	struct ib_other_headers *ohdr = packet->ohdr;
308 	u32 opcode = packet->opcode;
309 	u32 hdrsize = packet->hlen;
310 	u32 psn;
311 	u32 pad = packet->pad;
312 	struct ib_wc wc;
313 	u32 pmtu = qp->pmtu;
314 	struct ib_reth *reth;
315 	int ret;
316 	u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
317 
318 	if (hfi1_ruc_check_hdr(ibp, packet))
319 		return;
320 
321 	process_ecn(qp, packet);
322 
323 	psn = ib_bth_get_psn(ohdr);
324 	/* Compare the PSN verses the expected PSN. */
325 	if (unlikely(cmp_psn(psn, qp->r_psn) != 0)) {
326 		/*
327 		 * Handle a sequence error.
328 		 * Silently drop any current message.
329 		 */
330 		qp->r_psn = psn;
331 inv:
332 		if (qp->r_state == OP(SEND_FIRST) ||
333 		    qp->r_state == OP(SEND_MIDDLE)) {
334 			set_bit(RVT_R_REWIND_SGE, &qp->r_aflags);
335 			qp->r_sge.num_sge = 0;
336 		} else {
337 			rvt_put_ss(&qp->r_sge);
338 		}
339 		qp->r_state = OP(SEND_LAST);
340 		switch (opcode) {
341 		case OP(SEND_FIRST):
342 		case OP(SEND_ONLY):
343 		case OP(SEND_ONLY_WITH_IMMEDIATE):
344 			goto send_first;
345 
346 		case OP(RDMA_WRITE_FIRST):
347 		case OP(RDMA_WRITE_ONLY):
348 		case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
349 			goto rdma_first;
350 
351 		default:
352 			goto drop;
353 		}
354 	}
355 
356 	/* Check for opcode sequence errors. */
357 	switch (qp->r_state) {
358 	case OP(SEND_FIRST):
359 	case OP(SEND_MIDDLE):
360 		if (opcode == OP(SEND_MIDDLE) ||
361 		    opcode == OP(SEND_LAST) ||
362 		    opcode == OP(SEND_LAST_WITH_IMMEDIATE))
363 			break;
364 		goto inv;
365 
366 	case OP(RDMA_WRITE_FIRST):
367 	case OP(RDMA_WRITE_MIDDLE):
368 		if (opcode == OP(RDMA_WRITE_MIDDLE) ||
369 		    opcode == OP(RDMA_WRITE_LAST) ||
370 		    opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
371 			break;
372 		goto inv;
373 
374 	default:
375 		if (opcode == OP(SEND_FIRST) ||
376 		    opcode == OP(SEND_ONLY) ||
377 		    opcode == OP(SEND_ONLY_WITH_IMMEDIATE) ||
378 		    opcode == OP(RDMA_WRITE_FIRST) ||
379 		    opcode == OP(RDMA_WRITE_ONLY) ||
380 		    opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
381 			break;
382 		goto inv;
383 	}
384 
385 	if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
386 		rvt_comm_est(qp);
387 
388 	/* OK, process the packet. */
389 	switch (opcode) {
390 	case OP(SEND_FIRST):
391 	case OP(SEND_ONLY):
392 	case OP(SEND_ONLY_WITH_IMMEDIATE):
393 send_first:
394 		if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
395 			qp->r_sge = qp->s_rdma_read_sge;
396 		} else {
397 			ret = rvt_get_rwqe(qp, false);
398 			if (ret < 0)
399 				goto op_err;
400 			if (!ret)
401 				goto drop;
402 			/*
403 			 * qp->s_rdma_read_sge will be the owner
404 			 * of the mr references.
405 			 */
406 			qp->s_rdma_read_sge = qp->r_sge;
407 		}
408 		qp->r_rcv_len = 0;
409 		if (opcode == OP(SEND_ONLY))
410 			goto no_immediate_data;
411 		else if (opcode == OP(SEND_ONLY_WITH_IMMEDIATE))
412 			goto send_last_imm;
413 		fallthrough;
414 	case OP(SEND_MIDDLE):
415 		/* Check for invalid length PMTU or posted rwqe len. */
416 		/*
417 		 * There will be no padding for 9B packet but 16B packets
418 		 * will come in with some padding since we always add
419 		 * CRC and LT bytes which will need to be flit aligned
420 		 */
421 		if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
422 			goto rewind;
423 		qp->r_rcv_len += pmtu;
424 		if (unlikely(qp->r_rcv_len > qp->r_len))
425 			goto rewind;
426 		rvt_copy_sge(qp, &qp->r_sge, data, pmtu, false, false);
427 		break;
428 
429 	case OP(SEND_LAST_WITH_IMMEDIATE):
430 send_last_imm:
431 		wc.ex.imm_data = ohdr->u.imm_data;
432 		wc.wc_flags = IB_WC_WITH_IMM;
433 		goto send_last;
434 	case OP(SEND_LAST):
435 no_immediate_data:
436 		wc.ex.imm_data = 0;
437 		wc.wc_flags = 0;
438 send_last:
439 		/* Check for invalid length. */
440 		/* LAST len should be >= 1 */
441 		if (unlikely(tlen < (hdrsize + extra_bytes)))
442 			goto rewind;
443 		/* Don't count the CRC. */
444 		tlen -= (hdrsize + extra_bytes);
445 		wc.byte_len = tlen + qp->r_rcv_len;
446 		if (unlikely(wc.byte_len > qp->r_len))
447 			goto rewind;
448 		wc.opcode = IB_WC_RECV;
449 		rvt_copy_sge(qp, &qp->r_sge, data, tlen, false, false);
450 		rvt_put_ss(&qp->s_rdma_read_sge);
451 last_imm:
452 		wc.wr_id = qp->r_wr_id;
453 		wc.status = IB_WC_SUCCESS;
454 		wc.qp = &qp->ibqp;
455 		wc.src_qp = qp->remote_qpn;
456 		wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
457 		/*
458 		 * It seems that IB mandates the presence of an SL in a
459 		 * work completion only for the UD transport (see section
460 		 * 11.4.2 of IBTA Vol. 1).
461 		 *
462 		 * However, the way the SL is chosen below is consistent
463 		 * with the way that IB/qib works and is trying avoid
464 		 * introducing incompatibilities.
465 		 *
466 		 * See also OPA Vol. 1, section 9.7.6, and table 9-17.
467 		 */
468 		wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
469 		/* zero fields that are N/A */
470 		wc.vendor_err = 0;
471 		wc.pkey_index = 0;
472 		wc.dlid_path_bits = 0;
473 		wc.port_num = 0;
474 		/* Signal completion event if the solicited bit is set. */
475 		rvt_recv_cq(qp, &wc, ib_bth_is_solicited(ohdr));
476 		break;
477 
478 	case OP(RDMA_WRITE_FIRST):
479 	case OP(RDMA_WRITE_ONLY):
480 	case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE): /* consume RWQE */
481 rdma_first:
482 		if (unlikely(!(qp->qp_access_flags &
483 			       IB_ACCESS_REMOTE_WRITE))) {
484 			goto drop;
485 		}
486 		reth = &ohdr->u.rc.reth;
487 		qp->r_len = be32_to_cpu(reth->length);
488 		qp->r_rcv_len = 0;
489 		qp->r_sge.sg_list = NULL;
490 		if (qp->r_len != 0) {
491 			u32 rkey = be32_to_cpu(reth->rkey);
492 			u64 vaddr = be64_to_cpu(reth->vaddr);
493 			int ok;
494 
495 			/* Check rkey */
496 			ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len,
497 					 vaddr, rkey, IB_ACCESS_REMOTE_WRITE);
498 			if (unlikely(!ok))
499 				goto drop;
500 			qp->r_sge.num_sge = 1;
501 		} else {
502 			qp->r_sge.num_sge = 0;
503 			qp->r_sge.sge.mr = NULL;
504 			qp->r_sge.sge.vaddr = NULL;
505 			qp->r_sge.sge.length = 0;
506 			qp->r_sge.sge.sge_length = 0;
507 		}
508 		if (opcode == OP(RDMA_WRITE_ONLY)) {
509 			goto rdma_last;
510 		} else if (opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE)) {
511 			wc.ex.imm_data = ohdr->u.rc.imm_data;
512 			goto rdma_last_imm;
513 		}
514 		fallthrough;
515 	case OP(RDMA_WRITE_MIDDLE):
516 		/* Check for invalid length PMTU or posted rwqe len. */
517 		if (unlikely(tlen != (hdrsize + pmtu + 4)))
518 			goto drop;
519 		qp->r_rcv_len += pmtu;
520 		if (unlikely(qp->r_rcv_len > qp->r_len))
521 			goto drop;
522 		rvt_copy_sge(qp, &qp->r_sge, data, pmtu, true, false);
523 		break;
524 
525 	case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
526 		wc.ex.imm_data = ohdr->u.imm_data;
527 rdma_last_imm:
528 		wc.wc_flags = IB_WC_WITH_IMM;
529 
530 		/* Check for invalid length. */
531 		/* LAST len should be >= 1 */
532 		if (unlikely(tlen < (hdrsize + pad + 4)))
533 			goto drop;
534 		/* Don't count the CRC. */
535 		tlen -= (hdrsize + extra_bytes);
536 		if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
537 			goto drop;
538 		if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
539 			rvt_put_ss(&qp->s_rdma_read_sge);
540 		} else {
541 			ret = rvt_get_rwqe(qp, true);
542 			if (ret < 0)
543 				goto op_err;
544 			if (!ret)
545 				goto drop;
546 		}
547 		wc.byte_len = qp->r_len;
548 		wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
549 		rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, false);
550 		rvt_put_ss(&qp->r_sge);
551 		goto last_imm;
552 
553 	case OP(RDMA_WRITE_LAST):
554 rdma_last:
555 		/* Check for invalid length. */
556 		/* LAST len should be >= 1 */
557 		if (unlikely(tlen < (hdrsize + pad + 4)))
558 			goto drop;
559 		/* Don't count the CRC. */
560 		tlen -= (hdrsize + extra_bytes);
561 		if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
562 			goto drop;
563 		rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, false);
564 		rvt_put_ss(&qp->r_sge);
565 		break;
566 
567 	default:
568 		/* Drop packet for unknown opcodes. */
569 		goto drop;
570 	}
571 	qp->r_psn++;
572 	qp->r_state = opcode;
573 	return;
574 
575 rewind:
576 	set_bit(RVT_R_REWIND_SGE, &qp->r_aflags);
577 	qp->r_sge.num_sge = 0;
578 drop:
579 	ibp->rvp.n_pkt_drops++;
580 	return;
581 
582 op_err:
583 	rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
584 }
585