xref: /openbmc/linux/drivers/infiniband/hw/hfi1/uc.c (revision 68198dca)
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 "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 (IS_ERR(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 		smp_read_barrier_depends(); /* see post_one_send() */
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 		hfi1_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 		smp_read_barrier_depends(); /* see post_one_send() */
123 		if (qp->s_cur == READ_ONCE(qp->s_head)) {
124 			clear_ahg(qp);
125 			goto bail;
126 		}
127 		/*
128 		 * Local operations are processed immediately
129 		 * after all prior requests have completed.
130 		 */
131 		if (wqe->wr.opcode == IB_WR_REG_MR ||
132 		    wqe->wr.opcode == IB_WR_LOCAL_INV) {
133 			int local_ops = 0;
134 			int err = 0;
135 
136 			if (qp->s_last != qp->s_cur)
137 				goto bail;
138 			if (++qp->s_cur == qp->s_size)
139 				qp->s_cur = 0;
140 			if (!(wqe->wr.send_flags & RVT_SEND_COMPLETION_ONLY)) {
141 				err = rvt_invalidate_rkey(
142 					qp, wqe->wr.ex.invalidate_rkey);
143 				local_ops = 1;
144 			}
145 			hfi1_send_complete(qp, wqe, err ? IB_WC_LOC_PROT_ERR
146 							: IB_WC_SUCCESS);
147 			if (local_ops)
148 				atomic_dec(&qp->local_ops_pending);
149 			qp->s_hdrwords = 0;
150 			goto done_free_tx;
151 		}
152 		/*
153 		 * Start a new request.
154 		 */
155 		qp->s_psn = wqe->psn;
156 		qp->s_sge.sge = wqe->sg_list[0];
157 		qp->s_sge.sg_list = wqe->sg_list + 1;
158 		qp->s_sge.num_sge = wqe->wr.num_sge;
159 		qp->s_sge.total_len = wqe->length;
160 		len = wqe->length;
161 		qp->s_len = len;
162 		switch (wqe->wr.opcode) {
163 		case IB_WR_SEND:
164 		case IB_WR_SEND_WITH_IMM:
165 			if (len > pmtu) {
166 				qp->s_state = OP(SEND_FIRST);
167 				len = pmtu;
168 				break;
169 			}
170 			if (wqe->wr.opcode == IB_WR_SEND) {
171 				qp->s_state = OP(SEND_ONLY);
172 			} else {
173 				qp->s_state =
174 					OP(SEND_ONLY_WITH_IMMEDIATE);
175 				/* Immediate data comes after the BTH */
176 				ohdr->u.imm_data = wqe->wr.ex.imm_data;
177 				hwords += 1;
178 			}
179 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
180 				bth0 |= IB_BTH_SOLICITED;
181 			qp->s_wqe = wqe;
182 			if (++qp->s_cur >= qp->s_size)
183 				qp->s_cur = 0;
184 			break;
185 
186 		case IB_WR_RDMA_WRITE:
187 		case IB_WR_RDMA_WRITE_WITH_IMM:
188 			ohdr->u.rc.reth.vaddr =
189 				cpu_to_be64(wqe->rdma_wr.remote_addr);
190 			ohdr->u.rc.reth.rkey =
191 				cpu_to_be32(wqe->rdma_wr.rkey);
192 			ohdr->u.rc.reth.length = cpu_to_be32(len);
193 			hwords += sizeof(struct ib_reth) / 4;
194 			if (len > pmtu) {
195 				qp->s_state = OP(RDMA_WRITE_FIRST);
196 				len = pmtu;
197 				break;
198 			}
199 			if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
200 				qp->s_state = OP(RDMA_WRITE_ONLY);
201 			} else {
202 				qp->s_state =
203 					OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
204 				/* Immediate data comes after the RETH */
205 				ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
206 				hwords += 1;
207 				if (wqe->wr.send_flags & IB_SEND_SOLICITED)
208 					bth0 |= IB_BTH_SOLICITED;
209 			}
210 			qp->s_wqe = wqe;
211 			if (++qp->s_cur >= qp->s_size)
212 				qp->s_cur = 0;
213 			break;
214 
215 		default:
216 			goto bail;
217 		}
218 		break;
219 
220 	case OP(SEND_FIRST):
221 		qp->s_state = OP(SEND_MIDDLE);
222 		/* FALLTHROUGH */
223 	case OP(SEND_MIDDLE):
224 		len = qp->s_len;
225 		if (len > pmtu) {
226 			len = pmtu;
227 			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
228 			break;
229 		}
230 		if (wqe->wr.opcode == IB_WR_SEND) {
231 			qp->s_state = OP(SEND_LAST);
232 		} else {
233 			qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
234 			/* Immediate data comes after the BTH */
235 			ohdr->u.imm_data = wqe->wr.ex.imm_data;
236 			hwords += 1;
237 		}
238 		if (wqe->wr.send_flags & IB_SEND_SOLICITED)
239 			bth0 |= IB_BTH_SOLICITED;
240 		qp->s_wqe = wqe;
241 		if (++qp->s_cur >= qp->s_size)
242 			qp->s_cur = 0;
243 		break;
244 
245 	case OP(RDMA_WRITE_FIRST):
246 		qp->s_state = OP(RDMA_WRITE_MIDDLE);
247 		/* FALLTHROUGH */
248 	case OP(RDMA_WRITE_MIDDLE):
249 		len = qp->s_len;
250 		if (len > pmtu) {
251 			len = pmtu;
252 			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
253 			break;
254 		}
255 		if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
256 			qp->s_state = OP(RDMA_WRITE_LAST);
257 		} else {
258 			qp->s_state =
259 				OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
260 			/* Immediate data comes after the BTH */
261 			ohdr->u.imm_data = wqe->wr.ex.imm_data;
262 			hwords += 1;
263 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
264 				bth0 |= IB_BTH_SOLICITED;
265 		}
266 		qp->s_wqe = wqe;
267 		if (++qp->s_cur >= qp->s_size)
268 			qp->s_cur = 0;
269 		break;
270 	}
271 	qp->s_len -= len;
272 	qp->s_hdrwords = hwords;
273 	ps->s_txreq->sde = priv->s_sde;
274 	ps->s_txreq->ss = &qp->s_sge;
275 	ps->s_txreq->s_cur_size = len;
276 	hfi1_make_ruc_header(qp, ohdr, bth0 | (qp->s_state << 24),
277 			     mask_psn(qp->s_psn++), middle, ps);
278 	/* pbc */
279 	ps->s_txreq->hdr_dwords = qp->s_hdrwords + 2;
280 	return 1;
281 
282 done_free_tx:
283 	hfi1_put_txreq(ps->s_txreq);
284 	ps->s_txreq = NULL;
285 	return 1;
286 
287 bail:
288 	hfi1_put_txreq(ps->s_txreq);
289 
290 bail_no_tx:
291 	ps->s_txreq = NULL;
292 	qp->s_flags &= ~RVT_S_BUSY;
293 	qp->s_hdrwords = 0;
294 	return 0;
295 }
296 
297 /**
298  * hfi1_uc_rcv - handle an incoming UC packet
299  * @ibp: the port the packet came in on
300  * @hdr: the header of the packet
301  * @rcv_flags: flags relevant to rcv processing
302  * @data: the packet data
303  * @tlen: the length of the packet
304  * @qp: the QP for this packet.
305  *
306  * This is called from qp_rcv() to process an incoming UC packet
307  * for the given QP.
308  * Called at interrupt level.
309  */
310 void hfi1_uc_rcv(struct hfi1_packet *packet)
311 {
312 	struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
313 	void *data = packet->payload;
314 	u32 tlen = packet->tlen;
315 	struct rvt_qp *qp = packet->qp;
316 	struct ib_other_headers *ohdr = packet->ohdr;
317 	u32 opcode = packet->opcode;
318 	u32 hdrsize = packet->hlen;
319 	u32 psn;
320 	u32 pad = packet->pad;
321 	struct ib_wc wc;
322 	u32 pmtu = qp->pmtu;
323 	struct ib_reth *reth;
324 	int ret;
325 	u8 extra_bytes = pad + packet->extra_byte + (SIZE_OF_CRC << 2);
326 
327 	if (hfi1_ruc_check_hdr(ibp, packet))
328 		return;
329 
330 	process_ecn(qp, packet, true);
331 
332 	psn = ib_bth_get_psn(ohdr);
333 	/* Compare the PSN verses the expected PSN. */
334 	if (unlikely(cmp_psn(psn, qp->r_psn) != 0)) {
335 		/*
336 		 * Handle a sequence error.
337 		 * Silently drop any current message.
338 		 */
339 		qp->r_psn = psn;
340 inv:
341 		if (qp->r_state == OP(SEND_FIRST) ||
342 		    qp->r_state == OP(SEND_MIDDLE)) {
343 			set_bit(RVT_R_REWIND_SGE, &qp->r_aflags);
344 			qp->r_sge.num_sge = 0;
345 		} else {
346 			rvt_put_ss(&qp->r_sge);
347 		}
348 		qp->r_state = OP(SEND_LAST);
349 		switch (opcode) {
350 		case OP(SEND_FIRST):
351 		case OP(SEND_ONLY):
352 		case OP(SEND_ONLY_WITH_IMMEDIATE):
353 			goto send_first;
354 
355 		case OP(RDMA_WRITE_FIRST):
356 		case OP(RDMA_WRITE_ONLY):
357 		case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
358 			goto rdma_first;
359 
360 		default:
361 			goto drop;
362 		}
363 	}
364 
365 	/* Check for opcode sequence errors. */
366 	switch (qp->r_state) {
367 	case OP(SEND_FIRST):
368 	case OP(SEND_MIDDLE):
369 		if (opcode == OP(SEND_MIDDLE) ||
370 		    opcode == OP(SEND_LAST) ||
371 		    opcode == OP(SEND_LAST_WITH_IMMEDIATE))
372 			break;
373 		goto inv;
374 
375 	case OP(RDMA_WRITE_FIRST):
376 	case OP(RDMA_WRITE_MIDDLE):
377 		if (opcode == OP(RDMA_WRITE_MIDDLE) ||
378 		    opcode == OP(RDMA_WRITE_LAST) ||
379 		    opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
380 			break;
381 		goto inv;
382 
383 	default:
384 		if (opcode == OP(SEND_FIRST) ||
385 		    opcode == OP(SEND_ONLY) ||
386 		    opcode == OP(SEND_ONLY_WITH_IMMEDIATE) ||
387 		    opcode == OP(RDMA_WRITE_FIRST) ||
388 		    opcode == OP(RDMA_WRITE_ONLY) ||
389 		    opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
390 			break;
391 		goto inv;
392 	}
393 
394 	if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
395 		rvt_comm_est(qp);
396 
397 	/* OK, process the packet. */
398 	switch (opcode) {
399 	case OP(SEND_FIRST):
400 	case OP(SEND_ONLY):
401 	case OP(SEND_ONLY_WITH_IMMEDIATE):
402 send_first:
403 		if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
404 			qp->r_sge = qp->s_rdma_read_sge;
405 		} else {
406 			ret = hfi1_rvt_get_rwqe(qp, 0);
407 			if (ret < 0)
408 				goto op_err;
409 			if (!ret)
410 				goto drop;
411 			/*
412 			 * qp->s_rdma_read_sge will be the owner
413 			 * of the mr references.
414 			 */
415 			qp->s_rdma_read_sge = qp->r_sge;
416 		}
417 		qp->r_rcv_len = 0;
418 		if (opcode == OP(SEND_ONLY))
419 			goto no_immediate_data;
420 		else if (opcode == OP(SEND_ONLY_WITH_IMMEDIATE))
421 			goto send_last_imm;
422 		/* FALLTHROUGH */
423 	case OP(SEND_MIDDLE):
424 		/* Check for invalid length PMTU or posted rwqe len. */
425 		/*
426 		 * There will be no padding for 9B packet but 16B packets
427 		 * will come in with some padding since we always add
428 		 * CRC and LT bytes which will need to be flit aligned
429 		 */
430 		if (unlikely(tlen != (hdrsize + pmtu + extra_bytes)))
431 			goto rewind;
432 		qp->r_rcv_len += pmtu;
433 		if (unlikely(qp->r_rcv_len > qp->r_len))
434 			goto rewind;
435 		hfi1_copy_sge(&qp->r_sge, data, pmtu, false, false);
436 		break;
437 
438 	case OP(SEND_LAST_WITH_IMMEDIATE):
439 send_last_imm:
440 		wc.ex.imm_data = ohdr->u.imm_data;
441 		wc.wc_flags = IB_WC_WITH_IMM;
442 		goto send_last;
443 	case OP(SEND_LAST):
444 no_immediate_data:
445 		wc.ex.imm_data = 0;
446 		wc.wc_flags = 0;
447 send_last:
448 		/* Check for invalid length. */
449 		/* LAST len should be >= 1 */
450 		if (unlikely(tlen < (hdrsize + extra_bytes)))
451 			goto rewind;
452 		/* Don't count the CRC. */
453 		tlen -= (hdrsize + extra_bytes);
454 		wc.byte_len = tlen + qp->r_rcv_len;
455 		if (unlikely(wc.byte_len > qp->r_len))
456 			goto rewind;
457 		wc.opcode = IB_WC_RECV;
458 		hfi1_copy_sge(&qp->r_sge, data, tlen, false, false);
459 		rvt_put_ss(&qp->s_rdma_read_sge);
460 last_imm:
461 		wc.wr_id = qp->r_wr_id;
462 		wc.status = IB_WC_SUCCESS;
463 		wc.qp = &qp->ibqp;
464 		wc.src_qp = qp->remote_qpn;
465 		wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
466 		/*
467 		 * It seems that IB mandates the presence of an SL in a
468 		 * work completion only for the UD transport (see section
469 		 * 11.4.2 of IBTA Vol. 1).
470 		 *
471 		 * However, the way the SL is chosen below is consistent
472 		 * with the way that IB/qib works and is trying avoid
473 		 * introducing incompatibilities.
474 		 *
475 		 * See also OPA Vol. 1, section 9.7.6, and table 9-17.
476 		 */
477 		wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
478 		/* zero fields that are N/A */
479 		wc.vendor_err = 0;
480 		wc.pkey_index = 0;
481 		wc.dlid_path_bits = 0;
482 		wc.port_num = 0;
483 		/* Signal completion event if the solicited bit is set. */
484 		rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
485 			     (ohdr->bth[0] &
486 			      cpu_to_be32(IB_BTH_SOLICITED)) != 0);
487 		break;
488 
489 	case OP(RDMA_WRITE_FIRST):
490 	case OP(RDMA_WRITE_ONLY):
491 	case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE): /* consume RWQE */
492 rdma_first:
493 		if (unlikely(!(qp->qp_access_flags &
494 			       IB_ACCESS_REMOTE_WRITE))) {
495 			goto drop;
496 		}
497 		reth = &ohdr->u.rc.reth;
498 		qp->r_len = be32_to_cpu(reth->length);
499 		qp->r_rcv_len = 0;
500 		qp->r_sge.sg_list = NULL;
501 		if (qp->r_len != 0) {
502 			u32 rkey = be32_to_cpu(reth->rkey);
503 			u64 vaddr = be64_to_cpu(reth->vaddr);
504 			int ok;
505 
506 			/* Check rkey */
507 			ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len,
508 					 vaddr, rkey, IB_ACCESS_REMOTE_WRITE);
509 			if (unlikely(!ok))
510 				goto drop;
511 			qp->r_sge.num_sge = 1;
512 		} else {
513 			qp->r_sge.num_sge = 0;
514 			qp->r_sge.sge.mr = NULL;
515 			qp->r_sge.sge.vaddr = NULL;
516 			qp->r_sge.sge.length = 0;
517 			qp->r_sge.sge.sge_length = 0;
518 		}
519 		if (opcode == OP(RDMA_WRITE_ONLY)) {
520 			goto rdma_last;
521 		} else if (opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE)) {
522 			wc.ex.imm_data = ohdr->u.rc.imm_data;
523 			goto rdma_last_imm;
524 		}
525 		/* FALLTHROUGH */
526 	case OP(RDMA_WRITE_MIDDLE):
527 		/* Check for invalid length PMTU or posted rwqe len. */
528 		if (unlikely(tlen != (hdrsize + pmtu + 4)))
529 			goto drop;
530 		qp->r_rcv_len += pmtu;
531 		if (unlikely(qp->r_rcv_len > qp->r_len))
532 			goto drop;
533 		hfi1_copy_sge(&qp->r_sge, data, pmtu, true, false);
534 		break;
535 
536 	case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
537 		wc.ex.imm_data = ohdr->u.imm_data;
538 rdma_last_imm:
539 		wc.wc_flags = IB_WC_WITH_IMM;
540 
541 		/* Check for invalid length. */
542 		/* LAST len should be >= 1 */
543 		if (unlikely(tlen < (hdrsize + pad + 4)))
544 			goto drop;
545 		/* Don't count the CRC. */
546 		tlen -= (hdrsize + extra_bytes);
547 		if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
548 			goto drop;
549 		if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
550 			rvt_put_ss(&qp->s_rdma_read_sge);
551 		} else {
552 			ret = hfi1_rvt_get_rwqe(qp, 1);
553 			if (ret < 0)
554 				goto op_err;
555 			if (!ret)
556 				goto drop;
557 		}
558 		wc.byte_len = qp->r_len;
559 		wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
560 		hfi1_copy_sge(&qp->r_sge, data, tlen, true, false);
561 		rvt_put_ss(&qp->r_sge);
562 		goto last_imm;
563 
564 	case OP(RDMA_WRITE_LAST):
565 rdma_last:
566 		/* Check for invalid length. */
567 		/* LAST len should be >= 1 */
568 		if (unlikely(tlen < (hdrsize + pad + 4)))
569 			goto drop;
570 		/* Don't count the CRC. */
571 		tlen -= (hdrsize + extra_bytes);
572 		if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
573 			goto drop;
574 		hfi1_copy_sge(&qp->r_sge, data, tlen, true, false);
575 		rvt_put_ss(&qp->r_sge);
576 		break;
577 
578 	default:
579 		/* Drop packet for unknown opcodes. */
580 		goto drop;
581 	}
582 	qp->r_psn++;
583 	qp->r_state = opcode;
584 	return;
585 
586 rewind:
587 	set_bit(RVT_R_REWIND_SGE, &qp->r_aflags);
588 	qp->r_sge.num_sge = 0;
589 drop:
590 	ibp->rvp.n_pkt_drops++;
591 	return;
592 
593 op_err:
594 	rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
595 }
596