xref: /linux/drivers/infiniband/hw/hfi1/uc.c (revision 071bf69a0220253a44acb8b2a27f7a262b9a46bf)
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) IB_OPCODE_UC_##x
54 
55 /* only opcode mask for adaptive pio */
56 const u32 uc_only_opcode =
57 	BIT(OP(SEND_ONLY) & 0x1f) |
58 	BIT(OP(SEND_ONLY_WITH_IMMEDIATE & 0x1f)) |
59 	BIT(OP(RDMA_WRITE_ONLY & 0x1f)) |
60 	BIT(OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE & 0x1f));
61 
62 /**
63  * hfi1_make_uc_req - construct a request packet (SEND, RDMA write)
64  * @qp: a pointer to the QP
65  *
66  * Assume s_lock is held.
67  *
68  * Return 1 if constructed; otherwise, return 0.
69  */
70 int hfi1_make_uc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
71 {
72 	struct hfi1_qp_priv *priv = qp->priv;
73 	struct hfi1_other_headers *ohdr;
74 	struct rvt_swqe *wqe;
75 	u32 hwords = 5;
76 	u32 bth0 = 0;
77 	u32 len;
78 	u32 pmtu = qp->pmtu;
79 	int middle = 0;
80 
81 	ps->s_txreq = get_txreq(ps->dev, qp);
82 	if (IS_ERR(ps->s_txreq))
83 		goto bail_no_tx;
84 
85 	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
86 		if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
87 			goto bail;
88 		/* We are in the error state, flush the work request. */
89 		smp_read_barrier_depends(); /* see post_one_send() */
90 		if (qp->s_last == ACCESS_ONCE(qp->s_head))
91 			goto bail;
92 		/* If DMAs are in progress, we can't flush immediately. */
93 		if (iowait_sdma_pending(&priv->s_iowait)) {
94 			qp->s_flags |= RVT_S_WAIT_DMA;
95 			goto bail;
96 		}
97 		clear_ahg(qp);
98 		wqe = rvt_get_swqe_ptr(qp, qp->s_last);
99 		hfi1_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
100 		goto done_free_tx;
101 	}
102 
103 	ohdr = &ps->s_txreq->phdr.hdr.u.oth;
104 	if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
105 		ohdr = &ps->s_txreq->phdr.hdr.u.l.oth;
106 
107 	/* Get the next send request. */
108 	wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
109 	qp->s_wqe = NULL;
110 	switch (qp->s_state) {
111 	default:
112 		if (!(ib_rvt_state_ops[qp->state] &
113 		    RVT_PROCESS_NEXT_SEND_OK))
114 			goto bail;
115 		/* Check if send work queue is empty. */
116 		smp_read_barrier_depends(); /* see post_one_send() */
117 		if (qp->s_cur == ACCESS_ONCE(qp->s_head)) {
118 			clear_ahg(qp);
119 			goto bail;
120 		}
121 		/*
122 		 * Local operations are processed immediately
123 		 * after all prior requests have completed.
124 		 */
125 		if (wqe->wr.opcode == IB_WR_REG_MR ||
126 		    wqe->wr.opcode == IB_WR_LOCAL_INV) {
127 			int local_ops = 0;
128 			int err = 0;
129 
130 			if (qp->s_last != qp->s_cur)
131 				goto bail;
132 			if (++qp->s_cur == qp->s_size)
133 				qp->s_cur = 0;
134 			if (!(wqe->wr.send_flags & RVT_SEND_COMPLETION_ONLY)) {
135 				err = rvt_invalidate_rkey(
136 					qp, wqe->wr.ex.invalidate_rkey);
137 				local_ops = 1;
138 			}
139 			hfi1_send_complete(qp, wqe, err ? IB_WC_LOC_PROT_ERR
140 							: IB_WC_SUCCESS);
141 			if (local_ops)
142 				atomic_dec(&qp->local_ops_pending);
143 			qp->s_hdrwords = 0;
144 			goto done_free_tx;
145 		}
146 		/*
147 		 * Start a new request.
148 		 */
149 		qp->s_psn = wqe->psn;
150 		qp->s_sge.sge = wqe->sg_list[0];
151 		qp->s_sge.sg_list = wqe->sg_list + 1;
152 		qp->s_sge.num_sge = wqe->wr.num_sge;
153 		qp->s_sge.total_len = wqe->length;
154 		len = wqe->length;
155 		qp->s_len = len;
156 		switch (wqe->wr.opcode) {
157 		case IB_WR_SEND:
158 		case IB_WR_SEND_WITH_IMM:
159 			if (len > pmtu) {
160 				qp->s_state = OP(SEND_FIRST);
161 				len = pmtu;
162 				break;
163 			}
164 			if (wqe->wr.opcode == IB_WR_SEND) {
165 				qp->s_state = OP(SEND_ONLY);
166 			} else {
167 				qp->s_state =
168 					OP(SEND_ONLY_WITH_IMMEDIATE);
169 				/* Immediate data comes after the BTH */
170 				ohdr->u.imm_data = wqe->wr.ex.imm_data;
171 				hwords += 1;
172 			}
173 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
174 				bth0 |= IB_BTH_SOLICITED;
175 			qp->s_wqe = wqe;
176 			if (++qp->s_cur >= qp->s_size)
177 				qp->s_cur = 0;
178 			break;
179 
180 		case IB_WR_RDMA_WRITE:
181 		case IB_WR_RDMA_WRITE_WITH_IMM:
182 			ohdr->u.rc.reth.vaddr =
183 				cpu_to_be64(wqe->rdma_wr.remote_addr);
184 			ohdr->u.rc.reth.rkey =
185 				cpu_to_be32(wqe->rdma_wr.rkey);
186 			ohdr->u.rc.reth.length = cpu_to_be32(len);
187 			hwords += sizeof(struct ib_reth) / 4;
188 			if (len > pmtu) {
189 				qp->s_state = OP(RDMA_WRITE_FIRST);
190 				len = pmtu;
191 				break;
192 			}
193 			if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
194 				qp->s_state = OP(RDMA_WRITE_ONLY);
195 			} else {
196 				qp->s_state =
197 					OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
198 				/* Immediate data comes after the RETH */
199 				ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
200 				hwords += 1;
201 				if (wqe->wr.send_flags & IB_SEND_SOLICITED)
202 					bth0 |= IB_BTH_SOLICITED;
203 			}
204 			qp->s_wqe = wqe;
205 			if (++qp->s_cur >= qp->s_size)
206 				qp->s_cur = 0;
207 			break;
208 
209 		default:
210 			goto bail;
211 		}
212 		break;
213 
214 	case OP(SEND_FIRST):
215 		qp->s_state = OP(SEND_MIDDLE);
216 		/* FALLTHROUGH */
217 	case OP(SEND_MIDDLE):
218 		len = qp->s_len;
219 		if (len > pmtu) {
220 			len = pmtu;
221 			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
222 			break;
223 		}
224 		if (wqe->wr.opcode == IB_WR_SEND) {
225 			qp->s_state = OP(SEND_LAST);
226 		} else {
227 			qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
228 			/* Immediate data comes after the BTH */
229 			ohdr->u.imm_data = wqe->wr.ex.imm_data;
230 			hwords += 1;
231 		}
232 		if (wqe->wr.send_flags & IB_SEND_SOLICITED)
233 			bth0 |= IB_BTH_SOLICITED;
234 		qp->s_wqe = wqe;
235 		if (++qp->s_cur >= qp->s_size)
236 			qp->s_cur = 0;
237 		break;
238 
239 	case OP(RDMA_WRITE_FIRST):
240 		qp->s_state = OP(RDMA_WRITE_MIDDLE);
241 		/* FALLTHROUGH */
242 	case OP(RDMA_WRITE_MIDDLE):
243 		len = qp->s_len;
244 		if (len > pmtu) {
245 			len = pmtu;
246 			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
247 			break;
248 		}
249 		if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
250 			qp->s_state = OP(RDMA_WRITE_LAST);
251 		} else {
252 			qp->s_state =
253 				OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
254 			/* Immediate data comes after the BTH */
255 			ohdr->u.imm_data = wqe->wr.ex.imm_data;
256 			hwords += 1;
257 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
258 				bth0 |= IB_BTH_SOLICITED;
259 		}
260 		qp->s_wqe = wqe;
261 		if (++qp->s_cur >= qp->s_size)
262 			qp->s_cur = 0;
263 		break;
264 	}
265 	qp->s_len -= len;
266 	qp->s_hdrwords = hwords;
267 	ps->s_txreq->sde = priv->s_sde;
268 	qp->s_cur_sge = &qp->s_sge;
269 	qp->s_cur_size = len;
270 	hfi1_make_ruc_header(qp, ohdr, bth0 | (qp->s_state << 24),
271 			     mask_psn(qp->s_psn++), middle, ps);
272 	/* pbc */
273 	ps->s_txreq->hdr_dwords = qp->s_hdrwords + 2;
274 	return 1;
275 
276 done_free_tx:
277 	hfi1_put_txreq(ps->s_txreq);
278 	ps->s_txreq = NULL;
279 	return 1;
280 
281 bail:
282 	hfi1_put_txreq(ps->s_txreq);
283 
284 bail_no_tx:
285 	ps->s_txreq = NULL;
286 	qp->s_flags &= ~RVT_S_BUSY;
287 	qp->s_hdrwords = 0;
288 	return 0;
289 }
290 
291 /**
292  * hfi1_uc_rcv - handle an incoming UC packet
293  * @ibp: the port the packet came in on
294  * @hdr: the header of the packet
295  * @rcv_flags: flags relevant to rcv processing
296  * @data: the packet data
297  * @tlen: the length of the packet
298  * @qp: the QP for this packet.
299  *
300  * This is called from qp_rcv() to process an incoming UC packet
301  * for the given QP.
302  * Called at interrupt level.
303  */
304 void hfi1_uc_rcv(struct hfi1_packet *packet)
305 {
306 	struct hfi1_ibport *ibp = &packet->rcd->ppd->ibport_data;
307 	struct hfi1_ib_header *hdr = packet->hdr;
308 	u32 rcv_flags = packet->rcv_flags;
309 	void *data = packet->ebuf;
310 	u32 tlen = packet->tlen;
311 	struct rvt_qp *qp = packet->qp;
312 	struct hfi1_other_headers *ohdr = packet->ohdr;
313 	u32 bth0, opcode;
314 	u32 hdrsize = packet->hlen;
315 	u32 psn;
316 	u32 pad;
317 	struct ib_wc wc;
318 	u32 pmtu = qp->pmtu;
319 	struct ib_reth *reth;
320 	int has_grh = rcv_flags & HFI1_HAS_GRH;
321 	int ret;
322 
323 	bth0 = be32_to_cpu(ohdr->bth[0]);
324 	if (hfi1_ruc_check_hdr(ibp, hdr, has_grh, qp, bth0))
325 		return;
326 
327 	process_ecn(qp, packet, true);
328 
329 	psn = be32_to_cpu(ohdr->bth[2]);
330 	opcode = (bth0 >> 24) & 0xff;
331 
332 	/* Compare the PSN verses the expected PSN. */
333 	if (unlikely(cmp_psn(psn, qp->r_psn) != 0)) {
334 		/*
335 		 * Handle a sequence error.
336 		 * Silently drop any current message.
337 		 */
338 		qp->r_psn = psn;
339 inv:
340 		if (qp->r_state == OP(SEND_FIRST) ||
341 		    qp->r_state == OP(SEND_MIDDLE)) {
342 			set_bit(RVT_R_REWIND_SGE, &qp->r_aflags);
343 			qp->r_sge.num_sge = 0;
344 		} else {
345 			rvt_put_ss(&qp->r_sge);
346 		}
347 		qp->r_state = OP(SEND_LAST);
348 		switch (opcode) {
349 		case OP(SEND_FIRST):
350 		case OP(SEND_ONLY):
351 		case OP(SEND_ONLY_WITH_IMMEDIATE):
352 			goto send_first;
353 
354 		case OP(RDMA_WRITE_FIRST):
355 		case OP(RDMA_WRITE_ONLY):
356 		case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
357 			goto rdma_first;
358 
359 		default:
360 			goto drop;
361 		}
362 	}
363 
364 	/* Check for opcode sequence errors. */
365 	switch (qp->r_state) {
366 	case OP(SEND_FIRST):
367 	case OP(SEND_MIDDLE):
368 		if (opcode == OP(SEND_MIDDLE) ||
369 		    opcode == OP(SEND_LAST) ||
370 		    opcode == OP(SEND_LAST_WITH_IMMEDIATE))
371 			break;
372 		goto inv;
373 
374 	case OP(RDMA_WRITE_FIRST):
375 	case OP(RDMA_WRITE_MIDDLE):
376 		if (opcode == OP(RDMA_WRITE_MIDDLE) ||
377 		    opcode == OP(RDMA_WRITE_LAST) ||
378 		    opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
379 			break;
380 		goto inv;
381 
382 	default:
383 		if (opcode == OP(SEND_FIRST) ||
384 		    opcode == OP(SEND_ONLY) ||
385 		    opcode == OP(SEND_ONLY_WITH_IMMEDIATE) ||
386 		    opcode == OP(RDMA_WRITE_FIRST) ||
387 		    opcode == OP(RDMA_WRITE_ONLY) ||
388 		    opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
389 			break;
390 		goto inv;
391 	}
392 
393 	if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
394 		qp_comm_est(qp);
395 
396 	/* OK, process the packet. */
397 	switch (opcode) {
398 	case OP(SEND_FIRST):
399 	case OP(SEND_ONLY):
400 	case OP(SEND_ONLY_WITH_IMMEDIATE):
401 send_first:
402 		if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
403 			qp->r_sge = qp->s_rdma_read_sge;
404 		} else {
405 			ret = hfi1_rvt_get_rwqe(qp, 0);
406 			if (ret < 0)
407 				goto op_err;
408 			if (!ret)
409 				goto drop;
410 			/*
411 			 * qp->s_rdma_read_sge will be the owner
412 			 * of the mr references.
413 			 */
414 			qp->s_rdma_read_sge = qp->r_sge;
415 		}
416 		qp->r_rcv_len = 0;
417 		if (opcode == OP(SEND_ONLY))
418 			goto no_immediate_data;
419 		else if (opcode == OP(SEND_ONLY_WITH_IMMEDIATE))
420 			goto send_last_imm;
421 		/* FALLTHROUGH */
422 	case OP(SEND_MIDDLE):
423 		/* Check for invalid length PMTU or posted rwqe len. */
424 		if (unlikely(tlen != (hdrsize + pmtu + 4)))
425 			goto rewind;
426 		qp->r_rcv_len += pmtu;
427 		if (unlikely(qp->r_rcv_len > qp->r_len))
428 			goto rewind;
429 		hfi1_copy_sge(&qp->r_sge, data, pmtu, 0, 0);
430 		break;
431 
432 	case OP(SEND_LAST_WITH_IMMEDIATE):
433 send_last_imm:
434 		wc.ex.imm_data = ohdr->u.imm_data;
435 		wc.wc_flags = IB_WC_WITH_IMM;
436 		goto send_last;
437 	case OP(SEND_LAST):
438 no_immediate_data:
439 		wc.ex.imm_data = 0;
440 		wc.wc_flags = 0;
441 send_last:
442 		/* Get the number of bytes the message was padded by. */
443 		pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
444 		/* Check for invalid length. */
445 		/* LAST len should be >= 1 */
446 		if (unlikely(tlen < (hdrsize + pad + 4)))
447 			goto rewind;
448 		/* Don't count the CRC. */
449 		tlen -= (hdrsize + pad + 4);
450 		wc.byte_len = tlen + qp->r_rcv_len;
451 		if (unlikely(wc.byte_len > qp->r_len))
452 			goto rewind;
453 		wc.opcode = IB_WC_RECV;
454 		hfi1_copy_sge(&qp->r_sge, data, tlen, 0, 0);
455 		rvt_put_ss(&qp->s_rdma_read_sge);
456 last_imm:
457 		wc.wr_id = qp->r_wr_id;
458 		wc.status = IB_WC_SUCCESS;
459 		wc.qp = &qp->ibqp;
460 		wc.src_qp = qp->remote_qpn;
461 		wc.slid = qp->remote_ah_attr.dlid;
462 		/*
463 		 * It seems that IB mandates the presence of an SL in a
464 		 * work completion only for the UD transport (see section
465 		 * 11.4.2 of IBTA Vol. 1).
466 		 *
467 		 * However, the way the SL is chosen below is consistent
468 		 * with the way that IB/qib works and is trying avoid
469 		 * introducing incompatibilities.
470 		 *
471 		 * See also OPA Vol. 1, section 9.7.6, and table 9-17.
472 		 */
473 		wc.sl = qp->remote_ah_attr.sl;
474 		/* zero fields that are N/A */
475 		wc.vendor_err = 0;
476 		wc.pkey_index = 0;
477 		wc.dlid_path_bits = 0;
478 		wc.port_num = 0;
479 		/* Signal completion event if the solicited bit is set. */
480 		rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
481 			     (ohdr->bth[0] &
482 			      cpu_to_be32(IB_BTH_SOLICITED)) != 0);
483 		break;
484 
485 	case OP(RDMA_WRITE_FIRST):
486 	case OP(RDMA_WRITE_ONLY):
487 	case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE): /* consume RWQE */
488 rdma_first:
489 		if (unlikely(!(qp->qp_access_flags &
490 			       IB_ACCESS_REMOTE_WRITE))) {
491 			goto drop;
492 		}
493 		reth = &ohdr->u.rc.reth;
494 		qp->r_len = be32_to_cpu(reth->length);
495 		qp->r_rcv_len = 0;
496 		qp->r_sge.sg_list = NULL;
497 		if (qp->r_len != 0) {
498 			u32 rkey = be32_to_cpu(reth->rkey);
499 			u64 vaddr = be64_to_cpu(reth->vaddr);
500 			int ok;
501 
502 			/* Check rkey */
503 			ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len,
504 					 vaddr, rkey, IB_ACCESS_REMOTE_WRITE);
505 			if (unlikely(!ok))
506 				goto drop;
507 			qp->r_sge.num_sge = 1;
508 		} else {
509 			qp->r_sge.num_sge = 0;
510 			qp->r_sge.sge.mr = NULL;
511 			qp->r_sge.sge.vaddr = NULL;
512 			qp->r_sge.sge.length = 0;
513 			qp->r_sge.sge.sge_length = 0;
514 		}
515 		if (opcode == OP(RDMA_WRITE_ONLY)) {
516 			goto rdma_last;
517 		} else if (opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE)) {
518 			wc.ex.imm_data = ohdr->u.rc.imm_data;
519 			goto rdma_last_imm;
520 		}
521 		/* FALLTHROUGH */
522 	case OP(RDMA_WRITE_MIDDLE):
523 		/* Check for invalid length PMTU or posted rwqe len. */
524 		if (unlikely(tlen != (hdrsize + pmtu + 4)))
525 			goto drop;
526 		qp->r_rcv_len += pmtu;
527 		if (unlikely(qp->r_rcv_len > qp->r_len))
528 			goto drop;
529 		hfi1_copy_sge(&qp->r_sge, data, pmtu, 1, 0);
530 		break;
531 
532 	case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
533 		wc.ex.imm_data = ohdr->u.imm_data;
534 rdma_last_imm:
535 		wc.wc_flags = IB_WC_WITH_IMM;
536 
537 		/* Get the number of bytes the message was padded by. */
538 		pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
539 		/* Check for invalid length. */
540 		/* LAST len should be >= 1 */
541 		if (unlikely(tlen < (hdrsize + pad + 4)))
542 			goto drop;
543 		/* Don't count the CRC. */
544 		tlen -= (hdrsize + pad + 4);
545 		if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
546 			goto drop;
547 		if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags)) {
548 			rvt_put_ss(&qp->s_rdma_read_sge);
549 		} else {
550 			ret = hfi1_rvt_get_rwqe(qp, 1);
551 			if (ret < 0)
552 				goto op_err;
553 			if (!ret)
554 				goto drop;
555 		}
556 		wc.byte_len = qp->r_len;
557 		wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
558 		hfi1_copy_sge(&qp->r_sge, data, tlen, 1, 0);
559 		rvt_put_ss(&qp->r_sge);
560 		goto last_imm;
561 
562 	case OP(RDMA_WRITE_LAST):
563 rdma_last:
564 		/* Get the number of bytes the message was padded by. */
565 		pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
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 + pad + 4);
572 		if (unlikely(tlen + qp->r_rcv_len != qp->r_len))
573 			goto drop;
574 		hfi1_copy_sge(&qp->r_sge, data, tlen, 1, 0);
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 	hfi1_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
595 }
596