xref: /linux/drivers/infiniband/hw/hfi1/uc.c (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
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  *
59  * Assume s_lock is held.
60  *
61  * Return 1 if constructed; otherwise, return 0.
62  */
63 int hfi1_make_uc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
64 {
65 	struct hfi1_qp_priv *priv = qp->priv;
66 	struct ib_other_headers *ohdr;
67 	struct rvt_swqe *wqe;
68 	u32 hwords;
69 	u32 bth0 = 0;
70 	u32 len;
71 	u32 pmtu = qp->pmtu;
72 	int middle = 0;
73 
74 	ps->s_txreq = get_txreq(ps->dev, qp);
75 	if (!ps->s_txreq)
76 		goto bail_no_tx;
77 
78 	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
79 		if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
80 			goto bail;
81 		/* We are in the error state, flush the work request. */
82 		if (qp->s_last == READ_ONCE(qp->s_head))
83 			goto bail;
84 		/* If DMAs are in progress, we can't flush immediately. */
85 		if (iowait_sdma_pending(&priv->s_iowait)) {
86 			qp->s_flags |= RVT_S_WAIT_DMA;
87 			goto bail;
88 		}
89 		clear_ahg(qp);
90 		wqe = rvt_get_swqe_ptr(qp, qp->s_last);
91 		rvt_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
92 		goto done_free_tx;
93 	}
94 
95 	if (priv->hdr_type == HFI1_PKT_TYPE_9B) {
96 		/* header size in 32-bit words LRH+BTH = (8+12)/4. */
97 		hwords = 5;
98 		if (rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)
99 			ohdr = &ps->s_txreq->phdr.hdr.ibh.u.l.oth;
100 		else
101 			ohdr = &ps->s_txreq->phdr.hdr.ibh.u.oth;
102 	} else {
103 		/* header size in 32-bit words 16B LRH+BTH = (16+12)/4. */
104 		hwords = 7;
105 		if ((rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
106 		    (hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))))
107 			ohdr = &ps->s_txreq->phdr.hdr.opah.u.l.oth;
108 		else
109 			ohdr = &ps->s_txreq->phdr.hdr.opah.u.oth;
110 	}
111 
112 	/* Get the next send request. */
113 	wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
114 	qp->s_wqe = NULL;
115 	switch (qp->s_state) {
116 	default:
117 		if (!(ib_rvt_state_ops[qp->state] &
118 		    RVT_PROCESS_NEXT_SEND_OK))
119 			goto bail;
120 		/* Check if send work queue is empty. */
121 		if (qp->s_cur == READ_ONCE(qp->s_head)) {
122 			clear_ahg(qp);
123 			goto bail;
124 		}
125 		/*
126 		 * Local operations are processed immediately
127 		 * after all prior requests have completed.
128 		 */
129 		if (wqe->wr.opcode == IB_WR_REG_MR ||
130 		    wqe->wr.opcode == IB_WR_LOCAL_INV) {
131 			int local_ops = 0;
132 			int err = 0;
133 
134 			if (qp->s_last != qp->s_cur)
135 				goto bail;
136 			if (++qp->s_cur == qp->s_size)
137 				qp->s_cur = 0;
138 			if (!(wqe->wr.send_flags & RVT_SEND_COMPLETION_ONLY)) {
139 				err = rvt_invalidate_rkey(
140 					qp, wqe->wr.ex.invalidate_rkey);
141 				local_ops = 1;
142 			}
143 			rvt_send_complete(qp, wqe, err ? IB_WC_LOC_PROT_ERR
144 							: IB_WC_SUCCESS);
145 			if (local_ops)
146 				atomic_dec(&qp->local_ops_pending);
147 			goto done_free_tx;
148 		}
149 		/*
150 		 * Start a new request.
151 		 */
152 		qp->s_psn = wqe->psn;
153 		qp->s_sge.sge = wqe->sg_list[0];
154 		qp->s_sge.sg_list = wqe->sg_list + 1;
155 		qp->s_sge.num_sge = wqe->wr.num_sge;
156 		qp->s_sge.total_len = wqe->length;
157 		len = wqe->length;
158 		qp->s_len = len;
159 		switch (wqe->wr.opcode) {
160 		case IB_WR_SEND:
161 		case IB_WR_SEND_WITH_IMM:
162 			if (len > pmtu) {
163 				qp->s_state = OP(SEND_FIRST);
164 				len = pmtu;
165 				break;
166 			}
167 			if (wqe->wr.opcode == IB_WR_SEND) {
168 				qp->s_state = OP(SEND_ONLY);
169 			} else {
170 				qp->s_state =
171 					OP(SEND_ONLY_WITH_IMMEDIATE);
172 				/* Immediate data comes after the BTH */
173 				ohdr->u.imm_data = wqe->wr.ex.imm_data;
174 				hwords += 1;
175 			}
176 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
177 				bth0 |= IB_BTH_SOLICITED;
178 			qp->s_wqe = wqe;
179 			if (++qp->s_cur >= qp->s_size)
180 				qp->s_cur = 0;
181 			break;
182 
183 		case IB_WR_RDMA_WRITE:
184 		case IB_WR_RDMA_WRITE_WITH_IMM:
185 			ohdr->u.rc.reth.vaddr =
186 				cpu_to_be64(wqe->rdma_wr.remote_addr);
187 			ohdr->u.rc.reth.rkey =
188 				cpu_to_be32(wqe->rdma_wr.rkey);
189 			ohdr->u.rc.reth.length = cpu_to_be32(len);
190 			hwords += sizeof(struct ib_reth) / 4;
191 			if (len > pmtu) {
192 				qp->s_state = OP(RDMA_WRITE_FIRST);
193 				len = pmtu;
194 				break;
195 			}
196 			if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
197 				qp->s_state = OP(RDMA_WRITE_ONLY);
198 			} else {
199 				qp->s_state =
200 					OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
201 				/* Immediate data comes after the RETH */
202 				ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
203 				hwords += 1;
204 				if (wqe->wr.send_flags & IB_SEND_SOLICITED)
205 					bth0 |= IB_BTH_SOLICITED;
206 			}
207 			qp->s_wqe = wqe;
208 			if (++qp->s_cur >= qp->s_size)
209 				qp->s_cur = 0;
210 			break;
211 
212 		default:
213 			goto bail;
214 		}
215 		break;
216 
217 	case OP(SEND_FIRST):
218 		qp->s_state = OP(SEND_MIDDLE);
219 		fallthrough;
220 	case OP(SEND_MIDDLE):
221 		len = qp->s_len;
222 		if (len > pmtu) {
223 			len = pmtu;
224 			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
225 			break;
226 		}
227 		if (wqe->wr.opcode == IB_WR_SEND) {
228 			qp->s_state = OP(SEND_LAST);
229 		} else {
230 			qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
231 			/* Immediate data comes after the BTH */
232 			ohdr->u.imm_data = wqe->wr.ex.imm_data;
233 			hwords += 1;
234 		}
235 		if (wqe->wr.send_flags & IB_SEND_SOLICITED)
236 			bth0 |= IB_BTH_SOLICITED;
237 		qp->s_wqe = wqe;
238 		if (++qp->s_cur >= qp->s_size)
239 			qp->s_cur = 0;
240 		break;
241 
242 	case OP(RDMA_WRITE_FIRST):
243 		qp->s_state = OP(RDMA_WRITE_MIDDLE);
244 		fallthrough;
245 	case OP(RDMA_WRITE_MIDDLE):
246 		len = qp->s_len;
247 		if (len > pmtu) {
248 			len = pmtu;
249 			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
250 			break;
251 		}
252 		if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
253 			qp->s_state = OP(RDMA_WRITE_LAST);
254 		} else {
255 			qp->s_state =
256 				OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
257 			/* Immediate data comes after the BTH */
258 			ohdr->u.imm_data = wqe->wr.ex.imm_data;
259 			hwords += 1;
260 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
261 				bth0 |= IB_BTH_SOLICITED;
262 		}
263 		qp->s_wqe = wqe;
264 		if (++qp->s_cur >= qp->s_size)
265 			qp->s_cur = 0;
266 		break;
267 	}
268 	qp->s_len -= len;
269 	ps->s_txreq->hdr_dwords = hwords;
270 	ps->s_txreq->sde = priv->s_sde;
271 	ps->s_txreq->ss = &qp->s_sge;
272 	ps->s_txreq->s_cur_size = len;
273 	hfi1_make_ruc_header(qp, ohdr, bth0 | (qp->s_state << 24),
274 			     qp->remote_qpn, mask_psn(qp->s_psn++),
275 			     middle, ps);
276 	return 1;
277 
278 done_free_tx:
279 	hfi1_put_txreq(ps->s_txreq);
280 	ps->s_txreq = NULL;
281 	return 1;
282 
283 bail:
284 	hfi1_put_txreq(ps->s_txreq);
285 
286 bail_no_tx:
287 	ps->s_txreq = NULL;
288 	qp->s_flags &= ~RVT_S_BUSY;
289 	return 0;
290 }
291 
292 /**
293  * hfi1_uc_rcv - handle an incoming UC packet
294  * @ibp: the port the packet came in on
295  * @hdr: the header of the packet
296  * @rcv_flags: flags relevant to rcv processing
297  * @data: the packet data
298  * @tlen: the length of the packet
299  * @qp: the QP for this packet.
300  *
301  * This is called from qp_rcv() to process an incoming UC packet
302  * for the given QP.
303  * Called at interrupt level.
304  */
305 void hfi1_uc_rcv(struct hfi1_packet *packet)
306 {
307 	struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
308 	void *data = packet->payload;
309 	u32 tlen = packet->tlen;
310 	struct rvt_qp *qp = packet->qp;
311 	struct ib_other_headers *ohdr = packet->ohdr;
312 	u32 opcode = packet->opcode;
313 	u32 hdrsize = packet->hlen;
314 	u32 psn;
315 	u32 pad = packet->pad;
316 	struct ib_wc wc;
317 	u32 pmtu = qp->pmtu;
318 	struct ib_reth *reth;
319 	int ret;
320 	u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
321 
322 	if (hfi1_ruc_check_hdr(ibp, packet))
323 		return;
324 
325 	process_ecn(qp, packet);
326 
327 	psn = ib_bth_get_psn(ohdr);
328 	/* Compare the PSN verses the expected PSN. */
329 	if (unlikely(cmp_psn(psn, qp->r_psn) != 0)) {
330 		/*
331 		 * Handle a sequence error.
332 		 * Silently drop any current message.
333 		 */
334 		qp->r_psn = psn;
335 inv:
336 		if (qp->r_state == OP(SEND_FIRST) ||
337 		    qp->r_state == OP(SEND_MIDDLE)) {
338 			set_bit(RVT_R_REWIND_SGE, &qp->r_aflags);
339 			qp->r_sge.num_sge = 0;
340 		} else {
341 			rvt_put_ss(&qp->r_sge);
342 		}
343 		qp->r_state = OP(SEND_LAST);
344 		switch (opcode) {
345 		case OP(SEND_FIRST):
346 		case OP(SEND_ONLY):
347 		case OP(SEND_ONLY_WITH_IMMEDIATE):
348 			goto send_first;
349 
350 		case OP(RDMA_WRITE_FIRST):
351 		case OP(RDMA_WRITE_ONLY):
352 		case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
353 			goto rdma_first;
354 
355 		default:
356 			goto drop;
357 		}
358 	}
359 
360 	/* Check for opcode sequence errors. */
361 	switch (qp->r_state) {
362 	case OP(SEND_FIRST):
363 	case OP(SEND_MIDDLE):
364 		if (opcode == OP(SEND_MIDDLE) ||
365 		    opcode == OP(SEND_LAST) ||
366 		    opcode == OP(SEND_LAST_WITH_IMMEDIATE))
367 			break;
368 		goto inv;
369 
370 	case OP(RDMA_WRITE_FIRST):
371 	case OP(RDMA_WRITE_MIDDLE):
372 		if (opcode == OP(RDMA_WRITE_MIDDLE) ||
373 		    opcode == OP(RDMA_WRITE_LAST) ||
374 		    opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
375 			break;
376 		goto inv;
377 
378 	default:
379 		if (opcode == OP(SEND_FIRST) ||
380 		    opcode == OP(SEND_ONLY) ||
381 		    opcode == OP(SEND_ONLY_WITH_IMMEDIATE) ||
382 		    opcode == OP(RDMA_WRITE_FIRST) ||
383 		    opcode == OP(RDMA_WRITE_ONLY) ||
384 		    opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
385 			break;
386 		goto inv;
387 	}
388 
389 	if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
390 		rvt_comm_est(qp);
391 
392 	/* OK, process the packet. */
393 	switch (opcode) {
394 	case OP(SEND_FIRST):
395 	case OP(SEND_ONLY):
396 	case OP(SEND_ONLY_WITH_IMMEDIATE):
397 send_first:
398 		if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
399 			qp->r_sge = qp->s_rdma_read_sge;
400 		} else {
401 			ret = rvt_get_rwqe(qp, false);
402 			if (ret < 0)
403 				goto op_err;
404 			if (!ret)
405 				goto drop;
406 			/*
407 			 * qp->s_rdma_read_sge will be the owner
408 			 * of the mr references.
409 			 */
410 			qp->s_rdma_read_sge = qp->r_sge;
411 		}
412 		qp->r_rcv_len = 0;
413 		if (opcode == OP(SEND_ONLY))
414 			goto no_immediate_data;
415 		else if (opcode == OP(SEND_ONLY_WITH_IMMEDIATE))
416 			goto send_last_imm;
417 		fallthrough;
418 	case OP(SEND_MIDDLE):
419 		/* Check for invalid length PMTU or posted rwqe len. */
420 		/*
421 		 * There will be no padding for 9B packet but 16B packets
422 		 * will come in with some padding since we always add
423 		 * CRC and LT bytes which will need to be flit aligned
424 		 */
425 		if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
426 			goto rewind;
427 		qp->r_rcv_len += pmtu;
428 		if (unlikely(qp->r_rcv_len > qp->r_len))
429 			goto rewind;
430 		rvt_copy_sge(qp, &qp->r_sge, data, pmtu, false, false);
431 		break;
432 
433 	case OP(SEND_LAST_WITH_IMMEDIATE):
434 send_last_imm:
435 		wc.ex.imm_data = ohdr->u.imm_data;
436 		wc.wc_flags = IB_WC_WITH_IMM;
437 		goto send_last;
438 	case OP(SEND_LAST):
439 no_immediate_data:
440 		wc.ex.imm_data = 0;
441 		wc.wc_flags = 0;
442 send_last:
443 		/* Check for invalid length. */
444 		/* LAST len should be >= 1 */
445 		if (unlikely(tlen < (hdrsize + extra_bytes)))
446 			goto rewind;
447 		/* Don't count the CRC. */
448 		tlen -= (hdrsize + extra_bytes);
449 		wc.byte_len = tlen + qp->r_rcv_len;
450 		if (unlikely(wc.byte_len > qp->r_len))
451 			goto rewind;
452 		wc.opcode = IB_WC_RECV;
453 		rvt_copy_sge(qp, &qp->r_sge, data, tlen, false, false);
454 		rvt_put_ss(&qp->s_rdma_read_sge);
455 last_imm:
456 		wc.wr_id = qp->r_wr_id;
457 		wc.status = IB_WC_SUCCESS;
458 		wc.qp = &qp->ibqp;
459 		wc.src_qp = qp->remote_qpn;
460 		wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
461 		/*
462 		 * It seems that IB mandates the presence of an SL in a
463 		 * work completion only for the UD transport (see section
464 		 * 11.4.2 of IBTA Vol. 1).
465 		 *
466 		 * However, the way the SL is chosen below is consistent
467 		 * with the way that IB/qib works and is trying avoid
468 		 * introducing incompatibilities.
469 		 *
470 		 * See also OPA Vol. 1, section 9.7.6, and table 9-17.
471 		 */
472 		wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
473 		/* zero fields that are N/A */
474 		wc.vendor_err = 0;
475 		wc.pkey_index = 0;
476 		wc.dlid_path_bits = 0;
477 		wc.port_num = 0;
478 		/* Signal completion event if the solicited bit is set. */
479 		rvt_recv_cq(qp, &wc, ib_bth_is_solicited(ohdr));
480 		break;
481 
482 	case OP(RDMA_WRITE_FIRST):
483 	case OP(RDMA_WRITE_ONLY):
484 	case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE): /* consume RWQE */
485 rdma_first:
486 		if (unlikely(!(qp->qp_access_flags &
487 			       IB_ACCESS_REMOTE_WRITE))) {
488 			goto drop;
489 		}
490 		reth = &ohdr->u.rc.reth;
491 		qp->r_len = be32_to_cpu(reth->length);
492 		qp->r_rcv_len = 0;
493 		qp->r_sge.sg_list = NULL;
494 		if (qp->r_len != 0) {
495 			u32 rkey = be32_to_cpu(reth->rkey);
496 			u64 vaddr = be64_to_cpu(reth->vaddr);
497 			int ok;
498 
499 			/* Check rkey */
500 			ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len,
501 					 vaddr, rkey, IB_ACCESS_REMOTE_WRITE);
502 			if (unlikely(!ok))
503 				goto drop;
504 			qp->r_sge.num_sge = 1;
505 		} else {
506 			qp->r_sge.num_sge = 0;
507 			qp->r_sge.sge.mr = NULL;
508 			qp->r_sge.sge.vaddr = NULL;
509 			qp->r_sge.sge.length = 0;
510 			qp->r_sge.sge.sge_length = 0;
511 		}
512 		if (opcode == OP(RDMA_WRITE_ONLY)) {
513 			goto rdma_last;
514 		} else if (opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE)) {
515 			wc.ex.imm_data = ohdr->u.rc.imm_data;
516 			goto rdma_last_imm;
517 		}
518 		fallthrough;
519 	case OP(RDMA_WRITE_MIDDLE):
520 		/* Check for invalid length PMTU or posted rwqe len. */
521 		if (unlikely(tlen != (hdrsize + pmtu + 4)))
522 			goto drop;
523 		qp->r_rcv_len += pmtu;
524 		if (unlikely(qp->r_rcv_len > qp->r_len))
525 			goto drop;
526 		rvt_copy_sge(qp, &qp->r_sge, data, pmtu, true, false);
527 		break;
528 
529 	case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
530 		wc.ex.imm_data = ohdr->u.imm_data;
531 rdma_last_imm:
532 		wc.wc_flags = IB_WC_WITH_IMM;
533 
534 		/* Check for invalid length. */
535 		/* LAST len should be >= 1 */
536 		if (unlikely(tlen < (hdrsize + pad + 4)))
537 			goto drop;
538 		/* Don't count the CRC. */
539 		tlen -= (hdrsize + extra_bytes);
540 		if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
541 			goto drop;
542 		if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
543 			rvt_put_ss(&qp->s_rdma_read_sge);
544 		} else {
545 			ret = rvt_get_rwqe(qp, true);
546 			if (ret < 0)
547 				goto op_err;
548 			if (!ret)
549 				goto drop;
550 		}
551 		wc.byte_len = qp->r_len;
552 		wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
553 		rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, false);
554 		rvt_put_ss(&qp->r_sge);
555 		goto last_imm;
556 
557 	case OP(RDMA_WRITE_LAST):
558 rdma_last:
559 		/* Check for invalid length. */
560 		/* LAST len should be >= 1 */
561 		if (unlikely(tlen < (hdrsize + pad + 4)))
562 			goto drop;
563 		/* Don't count the CRC. */
564 		tlen -= (hdrsize + extra_bytes);
565 		if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
566 			goto drop;
567 		rvt_copy_sge(qp, &qp->r_sge, data, tlen, true, false);
568 		rvt_put_ss(&qp->r_sge);
569 		break;
570 
571 	default:
572 		/* Drop packet for unknown opcodes. */
573 		goto drop;
574 	}
575 	qp->r_psn++;
576 	qp->r_state = opcode;
577 	return;
578 
579 rewind:
580 	set_bit(RVT_R_REWIND_SGE, &qp->r_aflags);
581 	qp->r_sge.num_sge = 0;
582 drop:
583 	ibp->rvp.n_pkt_drops++;
584 	return;
585 
586 op_err:
587 	rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
588 }
589