xref: /openbmc/linux/drivers/infiniband/hw/qib/qib_ud.c (revision ae213c44)
1 /*
2  * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved.
3  * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 #include <rdma/ib_smi.h>
35 #include <rdma/ib_verbs.h>
36 
37 #include "qib.h"
38 #include "qib_mad.h"
39 
40 /**
41  * qib_ud_loopback - handle send on loopback QPs
42  * @sqp: the sending QP
43  * @swqe: the send work request
44  *
45  * This is called from qib_make_ud_req() to forward a WQE addressed
46  * to the same HCA.
47  * Note that the receive interrupt handler may be calling qib_ud_rcv()
48  * while this is being called.
49  */
50 static void qib_ud_loopback(struct rvt_qp *sqp, struct rvt_swqe *swqe)
51 {
52 	struct qib_ibport *ibp = to_iport(sqp->ibqp.device, sqp->port_num);
53 	struct qib_pportdata *ppd = ppd_from_ibp(ibp);
54 	struct qib_devdata *dd = ppd->dd;
55 	struct rvt_dev_info *rdi = &dd->verbs_dev.rdi;
56 	struct rvt_qp *qp;
57 	struct rdma_ah_attr *ah_attr;
58 	unsigned long flags;
59 	struct rvt_sge_state ssge;
60 	struct rvt_sge *sge;
61 	struct ib_wc wc;
62 	u32 length;
63 	enum ib_qp_type sqptype, dqptype;
64 
65 	rcu_read_lock();
66 	qp = rvt_lookup_qpn(rdi, &ibp->rvp, swqe->ud_wr.remote_qpn);
67 	if (!qp) {
68 		ibp->rvp.n_pkt_drops++;
69 		goto drop;
70 	}
71 
72 	sqptype = sqp->ibqp.qp_type == IB_QPT_GSI ?
73 			IB_QPT_UD : sqp->ibqp.qp_type;
74 	dqptype = qp->ibqp.qp_type == IB_QPT_GSI ?
75 			IB_QPT_UD : qp->ibqp.qp_type;
76 
77 	if (dqptype != sqptype ||
78 	    !(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
79 		ibp->rvp.n_pkt_drops++;
80 		goto drop;
81 	}
82 
83 	ah_attr = &ibah_to_rvtah(swqe->ud_wr.ah)->attr;
84 	ppd = ppd_from_ibp(ibp);
85 
86 	if (qp->ibqp.qp_num > 1) {
87 		u16 pkey1;
88 		u16 pkey2;
89 		u16 lid;
90 
91 		pkey1 = qib_get_pkey(ibp, sqp->s_pkey_index);
92 		pkey2 = qib_get_pkey(ibp, qp->s_pkey_index);
93 		if (unlikely(!qib_pkey_ok(pkey1, pkey2))) {
94 			lid = ppd->lid | (rdma_ah_get_path_bits(ah_attr) &
95 					  ((1 << ppd->lmc) - 1));
96 			qib_bad_pkey(ibp, pkey1,
97 				     rdma_ah_get_sl(ah_attr),
98 				     sqp->ibqp.qp_num, qp->ibqp.qp_num,
99 				     cpu_to_be16(lid),
100 				     cpu_to_be16(rdma_ah_get_dlid(ah_attr)));
101 			goto drop;
102 		}
103 	}
104 
105 	/*
106 	 * Check that the qkey matches (except for QP0, see 9.6.1.4.1).
107 	 * Qkeys with the high order bit set mean use the
108 	 * qkey from the QP context instead of the WR (see 10.2.5).
109 	 */
110 	if (qp->ibqp.qp_num) {
111 		u32 qkey;
112 
113 		qkey = (int)swqe->ud_wr.remote_qkey < 0 ?
114 			sqp->qkey : swqe->ud_wr.remote_qkey;
115 		if (unlikely(qkey != qp->qkey))
116 			goto drop;
117 	}
118 
119 	/*
120 	 * A GRH is expected to precede the data even if not
121 	 * present on the wire.
122 	 */
123 	length = swqe->length;
124 	memset(&wc, 0, sizeof(wc));
125 	wc.byte_len = length + sizeof(struct ib_grh);
126 
127 	if (swqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
128 		wc.wc_flags = IB_WC_WITH_IMM;
129 		wc.ex.imm_data = swqe->wr.ex.imm_data;
130 	}
131 
132 	spin_lock_irqsave(&qp->r_lock, flags);
133 
134 	/*
135 	 * Get the next work request entry to find where to put the data.
136 	 */
137 	if (qp->r_flags & RVT_R_REUSE_SGE)
138 		qp->r_flags &= ~RVT_R_REUSE_SGE;
139 	else {
140 		int ret;
141 
142 		ret = rvt_get_rwqe(qp, false);
143 		if (ret < 0) {
144 			rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
145 			goto bail_unlock;
146 		}
147 		if (!ret) {
148 			if (qp->ibqp.qp_num == 0)
149 				ibp->rvp.n_vl15_dropped++;
150 			goto bail_unlock;
151 		}
152 	}
153 	/* Silently drop packets which are too big. */
154 	if (unlikely(wc.byte_len > qp->r_len)) {
155 		qp->r_flags |= RVT_R_REUSE_SGE;
156 		ibp->rvp.n_pkt_drops++;
157 		goto bail_unlock;
158 	}
159 
160 	if (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
161 		struct ib_grh grh;
162 		const struct ib_global_route *grd = rdma_ah_read_grh(ah_attr);
163 
164 		qib_make_grh(ibp, &grh, grd, 0, 0);
165 		rvt_copy_sge(qp, &qp->r_sge, &grh,
166 			     sizeof(grh), true, false);
167 		wc.wc_flags |= IB_WC_GRH;
168 	} else
169 		rvt_skip_sge(&qp->r_sge, sizeof(struct ib_grh), true);
170 	ssge.sg_list = swqe->sg_list + 1;
171 	ssge.sge = *swqe->sg_list;
172 	ssge.num_sge = swqe->wr.num_sge;
173 	sge = &ssge.sge;
174 	while (length) {
175 		u32 len = rvt_get_sge_length(sge, length);
176 
177 		rvt_copy_sge(qp, &qp->r_sge, sge->vaddr, len, true, false);
178 		sge->vaddr += len;
179 		sge->length -= len;
180 		sge->sge_length -= len;
181 		if (sge->sge_length == 0) {
182 			if (--ssge.num_sge)
183 				*sge = *ssge.sg_list++;
184 		} else if (sge->length == 0 && sge->mr->lkey) {
185 			if (++sge->n >= RVT_SEGSZ) {
186 				if (++sge->m >= sge->mr->mapsz)
187 					break;
188 				sge->n = 0;
189 			}
190 			sge->vaddr =
191 				sge->mr->map[sge->m]->segs[sge->n].vaddr;
192 			sge->length =
193 				sge->mr->map[sge->m]->segs[sge->n].length;
194 		}
195 		length -= len;
196 	}
197 	rvt_put_ss(&qp->r_sge);
198 	if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
199 		goto bail_unlock;
200 	wc.wr_id = qp->r_wr_id;
201 	wc.status = IB_WC_SUCCESS;
202 	wc.opcode = IB_WC_RECV;
203 	wc.qp = &qp->ibqp;
204 	wc.src_qp = sqp->ibqp.qp_num;
205 	wc.pkey_index = qp->ibqp.qp_type == IB_QPT_GSI ?
206 		swqe->ud_wr.pkey_index : 0;
207 	wc.slid = ppd->lid | (rdma_ah_get_path_bits(ah_attr) &
208 				((1 << ppd->lmc) - 1));
209 	wc.sl = rdma_ah_get_sl(ah_attr);
210 	wc.dlid_path_bits = rdma_ah_get_dlid(ah_attr) & ((1 << ppd->lmc) - 1);
211 	wc.port_num = qp->port_num;
212 	/* Signal completion event if the solicited bit is set. */
213 	rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
214 		     swqe->wr.send_flags & IB_SEND_SOLICITED);
215 	ibp->rvp.n_loop_pkts++;
216 bail_unlock:
217 	spin_unlock_irqrestore(&qp->r_lock, flags);
218 drop:
219 	rcu_read_unlock();
220 }
221 
222 /**
223  * qib_make_ud_req - construct a UD request packet
224  * @qp: the QP
225  *
226  * Assumes the s_lock is held.
227  *
228  * Return 1 if constructed; otherwise, return 0.
229  */
230 int qib_make_ud_req(struct rvt_qp *qp, unsigned long *flags)
231 {
232 	struct qib_qp_priv *priv = qp->priv;
233 	struct ib_other_headers *ohdr;
234 	struct rdma_ah_attr *ah_attr;
235 	struct qib_pportdata *ppd;
236 	struct qib_ibport *ibp;
237 	struct rvt_swqe *wqe;
238 	u32 nwords;
239 	u32 extra_bytes;
240 	u32 bth0;
241 	u16 lrh0;
242 	u16 lid;
243 	int ret = 0;
244 	int next_cur;
245 
246 	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK)) {
247 		if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
248 			goto bail;
249 		/* We are in the error state, flush the work request. */
250 		if (qp->s_last == READ_ONCE(qp->s_head))
251 			goto bail;
252 		/* If DMAs are in progress, we can't flush immediately. */
253 		if (atomic_read(&priv->s_dma_busy)) {
254 			qp->s_flags |= RVT_S_WAIT_DMA;
255 			goto bail;
256 		}
257 		wqe = rvt_get_swqe_ptr(qp, qp->s_last);
258 		rvt_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
259 		goto done;
260 	}
261 
262 	/* see post_one_send() */
263 	if (qp->s_cur == READ_ONCE(qp->s_head))
264 		goto bail;
265 
266 	wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
267 	next_cur = qp->s_cur + 1;
268 	if (next_cur >= qp->s_size)
269 		next_cur = 0;
270 
271 	/* Construct the header. */
272 	ibp = to_iport(qp->ibqp.device, qp->port_num);
273 	ppd = ppd_from_ibp(ibp);
274 	ah_attr = &ibah_to_rvtah(wqe->ud_wr.ah)->attr;
275 	if (rdma_ah_get_dlid(ah_attr) >= be16_to_cpu(IB_MULTICAST_LID_BASE)) {
276 		if (rdma_ah_get_dlid(ah_attr) !=
277 				be16_to_cpu(IB_LID_PERMISSIVE))
278 			this_cpu_inc(ibp->pmastats->n_multicast_xmit);
279 		else
280 			this_cpu_inc(ibp->pmastats->n_unicast_xmit);
281 	} else {
282 		this_cpu_inc(ibp->pmastats->n_unicast_xmit);
283 		lid = rdma_ah_get_dlid(ah_attr) & ~((1 << ppd->lmc) - 1);
284 		if (unlikely(lid == ppd->lid)) {
285 			unsigned long tflags = *flags;
286 			/*
287 			 * If DMAs are in progress, we can't generate
288 			 * a completion for the loopback packet since
289 			 * it would be out of order.
290 			 * XXX Instead of waiting, we could queue a
291 			 * zero length descriptor so we get a callback.
292 			 */
293 			if (atomic_read(&priv->s_dma_busy)) {
294 				qp->s_flags |= RVT_S_WAIT_DMA;
295 				goto bail;
296 			}
297 			qp->s_cur = next_cur;
298 			spin_unlock_irqrestore(&qp->s_lock, tflags);
299 			qib_ud_loopback(qp, wqe);
300 			spin_lock_irqsave(&qp->s_lock, tflags);
301 			*flags = tflags;
302 			rvt_send_complete(qp, wqe, IB_WC_SUCCESS);
303 			goto done;
304 		}
305 	}
306 
307 	qp->s_cur = next_cur;
308 	extra_bytes = -wqe->length & 3;
309 	nwords = (wqe->length + extra_bytes) >> 2;
310 
311 	/* header size in 32-bit words LRH+BTH+DETH = (8+12+8)/4. */
312 	qp->s_hdrwords = 7;
313 	qp->s_cur_size = wqe->length;
314 	qp->s_cur_sge = &qp->s_sge;
315 	qp->s_srate = rdma_ah_get_static_rate(ah_attr);
316 	qp->s_wqe = wqe;
317 	qp->s_sge.sge = wqe->sg_list[0];
318 	qp->s_sge.sg_list = wqe->sg_list + 1;
319 	qp->s_sge.num_sge = wqe->wr.num_sge;
320 	qp->s_sge.total_len = wqe->length;
321 
322 	if (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
323 		/* Header size in 32-bit words. */
324 		qp->s_hdrwords += qib_make_grh(ibp, &priv->s_hdr->u.l.grh,
325 					       rdma_ah_read_grh(ah_attr),
326 					       qp->s_hdrwords, nwords);
327 		lrh0 = QIB_LRH_GRH;
328 		ohdr = &priv->s_hdr->u.l.oth;
329 		/*
330 		 * Don't worry about sending to locally attached multicast
331 		 * QPs.  It is unspecified by the spec. what happens.
332 		 */
333 	} else {
334 		/* Header size in 32-bit words. */
335 		lrh0 = QIB_LRH_BTH;
336 		ohdr = &priv->s_hdr->u.oth;
337 	}
338 	if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
339 		qp->s_hdrwords++;
340 		ohdr->u.ud.imm_data = wqe->wr.ex.imm_data;
341 		bth0 = IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE << 24;
342 	} else
343 		bth0 = IB_OPCODE_UD_SEND_ONLY << 24;
344 	lrh0 |= rdma_ah_get_sl(ah_attr) << 4;
345 	if (qp->ibqp.qp_type == IB_QPT_SMI)
346 		lrh0 |= 0xF000; /* Set VL (see ch. 13.5.3.1) */
347 	else
348 		lrh0 |= ibp->sl_to_vl[rdma_ah_get_sl(ah_attr)] << 12;
349 	priv->s_hdr->lrh[0] = cpu_to_be16(lrh0);
350 	priv->s_hdr->lrh[1] =
351 			cpu_to_be16(rdma_ah_get_dlid(ah_attr));  /* DEST LID */
352 	priv->s_hdr->lrh[2] =
353 			cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
354 	lid = ppd->lid;
355 	if (lid) {
356 		lid |= rdma_ah_get_path_bits(ah_attr) &
357 			((1 << ppd->lmc) - 1);
358 		priv->s_hdr->lrh[3] = cpu_to_be16(lid);
359 	} else
360 		priv->s_hdr->lrh[3] = IB_LID_PERMISSIVE;
361 	if (wqe->wr.send_flags & IB_SEND_SOLICITED)
362 		bth0 |= IB_BTH_SOLICITED;
363 	bth0 |= extra_bytes << 20;
364 	bth0 |= qp->ibqp.qp_type == IB_QPT_SMI ? QIB_DEFAULT_P_KEY :
365 		qib_get_pkey(ibp, qp->ibqp.qp_type == IB_QPT_GSI ?
366 			     wqe->ud_wr.pkey_index : qp->s_pkey_index);
367 	ohdr->bth[0] = cpu_to_be32(bth0);
368 	/*
369 	 * Use the multicast QP if the destination LID is a multicast LID.
370 	 */
371 	ohdr->bth[1] = rdma_ah_get_dlid(ah_attr) >=
372 			be16_to_cpu(IB_MULTICAST_LID_BASE) &&
373 		rdma_ah_get_dlid(ah_attr) != be16_to_cpu(IB_LID_PERMISSIVE) ?
374 		cpu_to_be32(QIB_MULTICAST_QPN) :
375 		cpu_to_be32(wqe->ud_wr.remote_qpn);
376 	ohdr->bth[2] = cpu_to_be32(wqe->psn & QIB_PSN_MASK);
377 	/*
378 	 * Qkeys with the high order bit set mean use the
379 	 * qkey from the QP context instead of the WR (see 10.2.5).
380 	 */
381 	ohdr->u.ud.deth[0] = cpu_to_be32((int)wqe->ud_wr.remote_qkey < 0 ?
382 					 qp->qkey : wqe->ud_wr.remote_qkey);
383 	ohdr->u.ud.deth[1] = cpu_to_be32(qp->ibqp.qp_num);
384 
385 done:
386 	return 1;
387 bail:
388 	qp->s_flags &= ~RVT_S_BUSY;
389 	return ret;
390 }
391 
392 static unsigned qib_lookup_pkey(struct qib_ibport *ibp, u16 pkey)
393 {
394 	struct qib_pportdata *ppd = ppd_from_ibp(ibp);
395 	struct qib_devdata *dd = ppd->dd;
396 	unsigned ctxt = ppd->hw_pidx;
397 	unsigned i;
398 
399 	pkey &= 0x7fff;	/* remove limited/full membership bit */
400 
401 	for (i = 0; i < ARRAY_SIZE(dd->rcd[ctxt]->pkeys); ++i)
402 		if ((dd->rcd[ctxt]->pkeys[i] & 0x7fff) == pkey)
403 			return i;
404 
405 	/*
406 	 * Should not get here, this means hardware failed to validate pkeys.
407 	 * Punt and return index 0.
408 	 */
409 	return 0;
410 }
411 
412 /**
413  * qib_ud_rcv - receive an incoming UD packet
414  * @ibp: the port the packet came in on
415  * @hdr: the packet header
416  * @has_grh: true if the packet has a GRH
417  * @data: the packet data
418  * @tlen: the packet length
419  * @qp: the QP the packet came on
420  *
421  * This is called from qib_qp_rcv() to process an incoming UD packet
422  * for the given QP.
423  * Called at interrupt level.
424  */
425 void qib_ud_rcv(struct qib_ibport *ibp, struct ib_header *hdr,
426 		int has_grh, void *data, u32 tlen, struct rvt_qp *qp)
427 {
428 	struct ib_other_headers *ohdr;
429 	int opcode;
430 	u32 hdrsize;
431 	u32 pad;
432 	struct ib_wc wc;
433 	u32 qkey;
434 	u32 src_qp;
435 	u16 dlid;
436 
437 	/* Check for GRH */
438 	if (!has_grh) {
439 		ohdr = &hdr->u.oth;
440 		hdrsize = 8 + 12 + 8;   /* LRH + BTH + DETH */
441 	} else {
442 		ohdr = &hdr->u.l.oth;
443 		hdrsize = 8 + 40 + 12 + 8; /* LRH + GRH + BTH + DETH */
444 	}
445 	qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
446 	src_qp = be32_to_cpu(ohdr->u.ud.deth[1]) & RVT_QPN_MASK;
447 
448 	/*
449 	 * Get the number of bytes the message was padded by
450 	 * and drop incomplete packets.
451 	 */
452 	pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
453 	if (unlikely(tlen < (hdrsize + pad + 4)))
454 		goto drop;
455 
456 	tlen -= hdrsize + pad + 4;
457 
458 	/*
459 	 * Check that the permissive LID is only used on QP0
460 	 * and the QKEY matches (see 9.6.1.4.1 and 9.6.1.5.1).
461 	 */
462 	if (qp->ibqp.qp_num) {
463 		if (unlikely(hdr->lrh[1] == IB_LID_PERMISSIVE ||
464 			     hdr->lrh[3] == IB_LID_PERMISSIVE))
465 			goto drop;
466 		if (qp->ibqp.qp_num > 1) {
467 			u16 pkey1, pkey2;
468 
469 			pkey1 = be32_to_cpu(ohdr->bth[0]);
470 			pkey2 = qib_get_pkey(ibp, qp->s_pkey_index);
471 			if (unlikely(!qib_pkey_ok(pkey1, pkey2))) {
472 				qib_bad_pkey(ibp,
473 					     pkey1,
474 					     (be16_to_cpu(hdr->lrh[0]) >> 4) &
475 						0xF,
476 					     src_qp, qp->ibqp.qp_num,
477 					     hdr->lrh[3], hdr->lrh[1]);
478 				return;
479 			}
480 		}
481 		if (unlikely(qkey != qp->qkey))
482 			return;
483 
484 		/* Drop invalid MAD packets (see 13.5.3.1). */
485 		if (unlikely(qp->ibqp.qp_num == 1 &&
486 			     (tlen != 256 ||
487 			      (be16_to_cpu(hdr->lrh[0]) >> 12) == 15)))
488 			goto drop;
489 	} else {
490 		struct ib_smp *smp;
491 
492 		/* Drop invalid MAD packets (see 13.5.3.1). */
493 		if (tlen != 256 || (be16_to_cpu(hdr->lrh[0]) >> 12) != 15)
494 			goto drop;
495 		smp = (struct ib_smp *) data;
496 		if ((hdr->lrh[1] == IB_LID_PERMISSIVE ||
497 		     hdr->lrh[3] == IB_LID_PERMISSIVE) &&
498 		    smp->mgmt_class != IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
499 			goto drop;
500 	}
501 
502 	/*
503 	 * The opcode is in the low byte when its in network order
504 	 * (top byte when in host order).
505 	 */
506 	opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
507 	if (qp->ibqp.qp_num > 1 &&
508 	    opcode == IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE) {
509 		wc.ex.imm_data = ohdr->u.ud.imm_data;
510 		wc.wc_flags = IB_WC_WITH_IMM;
511 	} else if (opcode == IB_OPCODE_UD_SEND_ONLY) {
512 		wc.ex.imm_data = 0;
513 		wc.wc_flags = 0;
514 	} else
515 		goto drop;
516 
517 	/*
518 	 * A GRH is expected to precede the data even if not
519 	 * present on the wire.
520 	 */
521 	wc.byte_len = tlen + sizeof(struct ib_grh);
522 
523 	/*
524 	 * Get the next work request entry to find where to put the data.
525 	 */
526 	if (qp->r_flags & RVT_R_REUSE_SGE)
527 		qp->r_flags &= ~RVT_R_REUSE_SGE;
528 	else {
529 		int ret;
530 
531 		ret = rvt_get_rwqe(qp, false);
532 		if (ret < 0) {
533 			rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
534 			return;
535 		}
536 		if (!ret) {
537 			if (qp->ibqp.qp_num == 0)
538 				ibp->rvp.n_vl15_dropped++;
539 			return;
540 		}
541 	}
542 	/* Silently drop packets which are too big. */
543 	if (unlikely(wc.byte_len > qp->r_len)) {
544 		qp->r_flags |= RVT_R_REUSE_SGE;
545 		goto drop;
546 	}
547 	if (has_grh) {
548 		rvt_copy_sge(qp, &qp->r_sge, &hdr->u.l.grh,
549 			     sizeof(struct ib_grh), true, false);
550 		wc.wc_flags |= IB_WC_GRH;
551 	} else
552 		rvt_skip_sge(&qp->r_sge, sizeof(struct ib_grh), true);
553 	rvt_copy_sge(qp, &qp->r_sge, data, wc.byte_len - sizeof(struct ib_grh),
554 		     true, false);
555 	rvt_put_ss(&qp->r_sge);
556 	if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
557 		return;
558 	wc.wr_id = qp->r_wr_id;
559 	wc.status = IB_WC_SUCCESS;
560 	wc.opcode = IB_WC_RECV;
561 	wc.vendor_err = 0;
562 	wc.qp = &qp->ibqp;
563 	wc.src_qp = src_qp;
564 	wc.pkey_index = qp->ibqp.qp_type == IB_QPT_GSI ?
565 		qib_lookup_pkey(ibp, be32_to_cpu(ohdr->bth[0])) : 0;
566 	wc.slid = be16_to_cpu(hdr->lrh[3]);
567 	wc.sl = (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF;
568 	dlid = be16_to_cpu(hdr->lrh[1]);
569 	/*
570 	 * Save the LMC lower bits if the destination LID is a unicast LID.
571 	 */
572 	wc.dlid_path_bits = dlid >= be16_to_cpu(IB_MULTICAST_LID_BASE) ? 0 :
573 		dlid & ((1 << ppd_from_ibp(ibp)->lmc) - 1);
574 	wc.port_num = qp->port_num;
575 	/* Signal completion event if the solicited bit is set. */
576 	rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
577 		     ib_bth_is_solicited(ohdr));
578 	return;
579 
580 drop:
581 	ibp->rvp.n_pkt_drops++;
582 }
583