1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2 /*
3  * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
4  * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
5  */
6 
7 #include <linux/skbuff.h>
8 
9 #include "rxe.h"
10 #include "rxe_loc.h"
11 #include "rxe_queue.h"
12 
13 static char *resp_state_name[] = {
14 	[RESPST_NONE]				= "NONE",
15 	[RESPST_GET_REQ]			= "GET_REQ",
16 	[RESPST_CHK_PSN]			= "CHK_PSN",
17 	[RESPST_CHK_OP_SEQ]			= "CHK_OP_SEQ",
18 	[RESPST_CHK_OP_VALID]			= "CHK_OP_VALID",
19 	[RESPST_CHK_RESOURCE]			= "CHK_RESOURCE",
20 	[RESPST_CHK_LENGTH]			= "CHK_LENGTH",
21 	[RESPST_CHK_RKEY]			= "CHK_RKEY",
22 	[RESPST_EXECUTE]			= "EXECUTE",
23 	[RESPST_READ_REPLY]			= "READ_REPLY",
24 	[RESPST_ATOMIC_REPLY]			= "ATOMIC_REPLY",
25 	[RESPST_ATOMIC_WRITE_REPLY]		= "ATOMIC_WRITE_REPLY",
26 	[RESPST_PROCESS_FLUSH]			= "PROCESS_FLUSH",
27 	[RESPST_COMPLETE]			= "COMPLETE",
28 	[RESPST_ACKNOWLEDGE]			= "ACKNOWLEDGE",
29 	[RESPST_CLEANUP]			= "CLEANUP",
30 	[RESPST_DUPLICATE_REQUEST]		= "DUPLICATE_REQUEST",
31 	[RESPST_ERR_MALFORMED_WQE]		= "ERR_MALFORMED_WQE",
32 	[RESPST_ERR_UNSUPPORTED_OPCODE]		= "ERR_UNSUPPORTED_OPCODE",
33 	[RESPST_ERR_MISALIGNED_ATOMIC]		= "ERR_MISALIGNED_ATOMIC",
34 	[RESPST_ERR_PSN_OUT_OF_SEQ]		= "ERR_PSN_OUT_OF_SEQ",
35 	[RESPST_ERR_MISSING_OPCODE_FIRST]	= "ERR_MISSING_OPCODE_FIRST",
36 	[RESPST_ERR_MISSING_OPCODE_LAST_C]	= "ERR_MISSING_OPCODE_LAST_C",
37 	[RESPST_ERR_MISSING_OPCODE_LAST_D1E]	= "ERR_MISSING_OPCODE_LAST_D1E",
38 	[RESPST_ERR_TOO_MANY_RDMA_ATM_REQ]	= "ERR_TOO_MANY_RDMA_ATM_REQ",
39 	[RESPST_ERR_RNR]			= "ERR_RNR",
40 	[RESPST_ERR_RKEY_VIOLATION]		= "ERR_RKEY_VIOLATION",
41 	[RESPST_ERR_INVALIDATE_RKEY]		= "ERR_INVALIDATE_RKEY_VIOLATION",
42 	[RESPST_ERR_LENGTH]			= "ERR_LENGTH",
43 	[RESPST_ERR_CQ_OVERFLOW]		= "ERR_CQ_OVERFLOW",
44 	[RESPST_ERROR]				= "ERROR",
45 	[RESPST_DONE]				= "DONE",
46 	[RESPST_EXIT]				= "EXIT",
47 };
48 
49 /* rxe_recv calls here to add a request packet to the input queue */
50 void rxe_resp_queue_pkt(struct rxe_qp *qp, struct sk_buff *skb)
51 {
52 	skb_queue_tail(&qp->req_pkts, skb);
53 	rxe_sched_task(&qp->recv_task);
54 }
55 
56 static inline enum resp_states get_req(struct rxe_qp *qp,
57 				       struct rxe_pkt_info **pkt_p)
58 {
59 	struct sk_buff *skb;
60 
61 	skb = skb_peek(&qp->req_pkts);
62 	if (!skb)
63 		return RESPST_EXIT;
64 
65 	*pkt_p = SKB_TO_PKT(skb);
66 
67 	return (qp->resp.res) ? RESPST_READ_REPLY : RESPST_CHK_PSN;
68 }
69 
70 static enum resp_states check_psn(struct rxe_qp *qp,
71 				  struct rxe_pkt_info *pkt)
72 {
73 	int diff = psn_compare(pkt->psn, qp->resp.psn);
74 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
75 
76 	switch (qp_type(qp)) {
77 	case IB_QPT_RC:
78 		if (diff > 0) {
79 			if (qp->resp.sent_psn_nak)
80 				return RESPST_CLEANUP;
81 
82 			qp->resp.sent_psn_nak = 1;
83 			rxe_counter_inc(rxe, RXE_CNT_OUT_OF_SEQ_REQ);
84 			return RESPST_ERR_PSN_OUT_OF_SEQ;
85 
86 		} else if (diff < 0) {
87 			rxe_counter_inc(rxe, RXE_CNT_DUP_REQ);
88 			return RESPST_DUPLICATE_REQUEST;
89 		}
90 
91 		if (qp->resp.sent_psn_nak)
92 			qp->resp.sent_psn_nak = 0;
93 
94 		break;
95 
96 	case IB_QPT_UC:
97 		if (qp->resp.drop_msg || diff != 0) {
98 			if (pkt->mask & RXE_START_MASK) {
99 				qp->resp.drop_msg = 0;
100 				return RESPST_CHK_OP_SEQ;
101 			}
102 
103 			qp->resp.drop_msg = 1;
104 			return RESPST_CLEANUP;
105 		}
106 		break;
107 	default:
108 		break;
109 	}
110 
111 	return RESPST_CHK_OP_SEQ;
112 }
113 
114 static enum resp_states check_op_seq(struct rxe_qp *qp,
115 				     struct rxe_pkt_info *pkt)
116 {
117 	switch (qp_type(qp)) {
118 	case IB_QPT_RC:
119 		switch (qp->resp.opcode) {
120 		case IB_OPCODE_RC_SEND_FIRST:
121 		case IB_OPCODE_RC_SEND_MIDDLE:
122 			switch (pkt->opcode) {
123 			case IB_OPCODE_RC_SEND_MIDDLE:
124 			case IB_OPCODE_RC_SEND_LAST:
125 			case IB_OPCODE_RC_SEND_LAST_WITH_IMMEDIATE:
126 			case IB_OPCODE_RC_SEND_LAST_WITH_INVALIDATE:
127 				return RESPST_CHK_OP_VALID;
128 			default:
129 				return RESPST_ERR_MISSING_OPCODE_LAST_C;
130 			}
131 
132 		case IB_OPCODE_RC_RDMA_WRITE_FIRST:
133 		case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
134 			switch (pkt->opcode) {
135 			case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
136 			case IB_OPCODE_RC_RDMA_WRITE_LAST:
137 			case IB_OPCODE_RC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
138 				return RESPST_CHK_OP_VALID;
139 			default:
140 				return RESPST_ERR_MISSING_OPCODE_LAST_C;
141 			}
142 
143 		default:
144 			switch (pkt->opcode) {
145 			case IB_OPCODE_RC_SEND_MIDDLE:
146 			case IB_OPCODE_RC_SEND_LAST:
147 			case IB_OPCODE_RC_SEND_LAST_WITH_IMMEDIATE:
148 			case IB_OPCODE_RC_SEND_LAST_WITH_INVALIDATE:
149 			case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
150 			case IB_OPCODE_RC_RDMA_WRITE_LAST:
151 			case IB_OPCODE_RC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
152 				return RESPST_ERR_MISSING_OPCODE_FIRST;
153 			default:
154 				return RESPST_CHK_OP_VALID;
155 			}
156 		}
157 		break;
158 
159 	case IB_QPT_UC:
160 		switch (qp->resp.opcode) {
161 		case IB_OPCODE_UC_SEND_FIRST:
162 		case IB_OPCODE_UC_SEND_MIDDLE:
163 			switch (pkt->opcode) {
164 			case IB_OPCODE_UC_SEND_MIDDLE:
165 			case IB_OPCODE_UC_SEND_LAST:
166 			case IB_OPCODE_UC_SEND_LAST_WITH_IMMEDIATE:
167 				return RESPST_CHK_OP_VALID;
168 			default:
169 				return RESPST_ERR_MISSING_OPCODE_LAST_D1E;
170 			}
171 
172 		case IB_OPCODE_UC_RDMA_WRITE_FIRST:
173 		case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
174 			switch (pkt->opcode) {
175 			case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
176 			case IB_OPCODE_UC_RDMA_WRITE_LAST:
177 			case IB_OPCODE_UC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
178 				return RESPST_CHK_OP_VALID;
179 			default:
180 				return RESPST_ERR_MISSING_OPCODE_LAST_D1E;
181 			}
182 
183 		default:
184 			switch (pkt->opcode) {
185 			case IB_OPCODE_UC_SEND_MIDDLE:
186 			case IB_OPCODE_UC_SEND_LAST:
187 			case IB_OPCODE_UC_SEND_LAST_WITH_IMMEDIATE:
188 			case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
189 			case IB_OPCODE_UC_RDMA_WRITE_LAST:
190 			case IB_OPCODE_UC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
191 				qp->resp.drop_msg = 1;
192 				return RESPST_CLEANUP;
193 			default:
194 				return RESPST_CHK_OP_VALID;
195 			}
196 		}
197 		break;
198 
199 	default:
200 		return RESPST_CHK_OP_VALID;
201 	}
202 }
203 
204 static bool check_qp_attr_access(struct rxe_qp *qp,
205 				 struct rxe_pkt_info *pkt)
206 {
207 	if (((pkt->mask & RXE_READ_MASK) &&
208 	     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_READ)) ||
209 	    ((pkt->mask & (RXE_WRITE_MASK | RXE_ATOMIC_WRITE_MASK)) &&
210 	     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_WRITE)) ||
211 	    ((pkt->mask & RXE_ATOMIC_MASK) &&
212 	     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
213 		return false;
214 
215 	if (pkt->mask & RXE_FLUSH_MASK) {
216 		u32 flush_type = feth_plt(pkt);
217 
218 		if ((flush_type & IB_FLUSH_GLOBAL &&
219 		     !(qp->attr.qp_access_flags & IB_ACCESS_FLUSH_GLOBAL)) ||
220 		    (flush_type & IB_FLUSH_PERSISTENT &&
221 		     !(qp->attr.qp_access_flags & IB_ACCESS_FLUSH_PERSISTENT)))
222 			return false;
223 	}
224 
225 	return true;
226 }
227 
228 static enum resp_states check_op_valid(struct rxe_qp *qp,
229 				       struct rxe_pkt_info *pkt)
230 {
231 	switch (qp_type(qp)) {
232 	case IB_QPT_RC:
233 		if (!check_qp_attr_access(qp, pkt))
234 			return RESPST_ERR_UNSUPPORTED_OPCODE;
235 
236 		break;
237 
238 	case IB_QPT_UC:
239 		if ((pkt->mask & RXE_WRITE_MASK) &&
240 		    !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_WRITE)) {
241 			qp->resp.drop_msg = 1;
242 			return RESPST_CLEANUP;
243 		}
244 
245 		break;
246 
247 	case IB_QPT_UD:
248 	case IB_QPT_GSI:
249 		break;
250 
251 	default:
252 		WARN_ON_ONCE(1);
253 		break;
254 	}
255 
256 	return RESPST_CHK_RESOURCE;
257 }
258 
259 static enum resp_states get_srq_wqe(struct rxe_qp *qp)
260 {
261 	struct rxe_srq *srq = qp->srq;
262 	struct rxe_queue *q = srq->rq.queue;
263 	struct rxe_recv_wqe *wqe;
264 	struct ib_event ev;
265 	unsigned int count;
266 	size_t size;
267 	unsigned long flags;
268 
269 	if (srq->error)
270 		return RESPST_ERR_RNR;
271 
272 	spin_lock_irqsave(&srq->rq.consumer_lock, flags);
273 
274 	wqe = queue_head(q, QUEUE_TYPE_FROM_CLIENT);
275 	if (!wqe) {
276 		spin_unlock_irqrestore(&srq->rq.consumer_lock, flags);
277 		return RESPST_ERR_RNR;
278 	}
279 
280 	/* don't trust user space data */
281 	if (unlikely(wqe->dma.num_sge > srq->rq.max_sge)) {
282 		spin_unlock_irqrestore(&srq->rq.consumer_lock, flags);
283 		rxe_dbg_qp(qp, "invalid num_sge in SRQ entry\n");
284 		return RESPST_ERR_MALFORMED_WQE;
285 	}
286 	size = sizeof(*wqe) + wqe->dma.num_sge*sizeof(struct rxe_sge);
287 	memcpy(&qp->resp.srq_wqe, wqe, size);
288 
289 	qp->resp.wqe = &qp->resp.srq_wqe.wqe;
290 	queue_advance_consumer(q, QUEUE_TYPE_FROM_CLIENT);
291 	count = queue_count(q, QUEUE_TYPE_FROM_CLIENT);
292 
293 	if (srq->limit && srq->ibsrq.event_handler && (count < srq->limit)) {
294 		srq->limit = 0;
295 		goto event;
296 	}
297 
298 	spin_unlock_irqrestore(&srq->rq.consumer_lock, flags);
299 	return RESPST_CHK_LENGTH;
300 
301 event:
302 	spin_unlock_irqrestore(&srq->rq.consumer_lock, flags);
303 	ev.device = qp->ibqp.device;
304 	ev.element.srq = qp->ibqp.srq;
305 	ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
306 	srq->ibsrq.event_handler(&ev, srq->ibsrq.srq_context);
307 	return RESPST_CHK_LENGTH;
308 }
309 
310 static enum resp_states check_resource(struct rxe_qp *qp,
311 				       struct rxe_pkt_info *pkt)
312 {
313 	struct rxe_srq *srq = qp->srq;
314 
315 	if (pkt->mask & (RXE_READ_OR_ATOMIC_MASK | RXE_ATOMIC_WRITE_MASK)) {
316 		/* it is the requesters job to not send
317 		 * too many read/atomic ops, we just
318 		 * recycle the responder resource queue
319 		 */
320 		if (likely(qp->attr.max_dest_rd_atomic > 0))
321 			return RESPST_CHK_LENGTH;
322 		else
323 			return RESPST_ERR_TOO_MANY_RDMA_ATM_REQ;
324 	}
325 
326 	if (pkt->mask & RXE_RWR_MASK) {
327 		if (srq)
328 			return get_srq_wqe(qp);
329 
330 		qp->resp.wqe = queue_head(qp->rq.queue,
331 				QUEUE_TYPE_FROM_CLIENT);
332 		return (qp->resp.wqe) ? RESPST_CHK_LENGTH : RESPST_ERR_RNR;
333 	}
334 
335 	return RESPST_CHK_LENGTH;
336 }
337 
338 static enum resp_states rxe_resp_check_length(struct rxe_qp *qp,
339 					      struct rxe_pkt_info *pkt)
340 {
341 	/*
342 	 * See IBA C9-92
343 	 * For UD QPs we only check if the packet will fit in the
344 	 * receive buffer later. For RDMA operations additional
345 	 * length checks are performed in check_rkey.
346 	 */
347 	if ((qp_type(qp) == IB_QPT_GSI) || (qp_type(qp) == IB_QPT_UD)) {
348 		unsigned int payload = payload_size(pkt);
349 		unsigned int recv_buffer_len = 0;
350 		int i;
351 
352 		for (i = 0; i < qp->resp.wqe->dma.num_sge; i++)
353 			recv_buffer_len += qp->resp.wqe->dma.sge[i].length;
354 		if (payload + sizeof(union rdma_network_hdr) > recv_buffer_len) {
355 			rxe_dbg_qp(qp, "The receive buffer is too small for this UD packet.\n");
356 			return RESPST_ERR_LENGTH;
357 		}
358 	}
359 
360 	if (pkt->mask & RXE_PAYLOAD_MASK && ((qp_type(qp) == IB_QPT_RC) ||
361 					     (qp_type(qp) == IB_QPT_UC))) {
362 		unsigned int mtu = qp->mtu;
363 		unsigned int payload = payload_size(pkt);
364 
365 		if ((pkt->mask & RXE_START_MASK) &&
366 		    (pkt->mask & RXE_END_MASK)) {
367 			if (unlikely(payload > mtu)) {
368 				rxe_dbg_qp(qp, "only packet too long\n");
369 				return RESPST_ERR_LENGTH;
370 			}
371 		} else if ((pkt->mask & RXE_START_MASK) ||
372 			   (pkt->mask & RXE_MIDDLE_MASK)) {
373 			if (unlikely(payload != mtu)) {
374 				rxe_dbg_qp(qp, "first or middle packet not mtu\n");
375 				return RESPST_ERR_LENGTH;
376 			}
377 		} else if (pkt->mask & RXE_END_MASK) {
378 			if (unlikely((payload == 0) || (payload > mtu))) {
379 				rxe_dbg_qp(qp, "last packet zero or too long\n");
380 				return RESPST_ERR_LENGTH;
381 			}
382 		}
383 	}
384 
385 	/* See IBA C9-94 */
386 	if (pkt->mask & RXE_RETH_MASK) {
387 		if (reth_len(pkt) > (1U << 31)) {
388 			rxe_dbg_qp(qp, "dma length too long\n");
389 			return RESPST_ERR_LENGTH;
390 		}
391 	}
392 
393 	if (pkt->mask & RXE_RDMA_OP_MASK)
394 		return RESPST_CHK_RKEY;
395 	else
396 		return RESPST_EXECUTE;
397 }
398 
399 /* if the reth length field is zero we can assume nothing
400  * about the rkey value and should not validate or use it.
401  * Instead set qp->resp.rkey to 0 which is an invalid rkey
402  * value since the minimum index part is 1.
403  */
404 static void qp_resp_from_reth(struct rxe_qp *qp, struct rxe_pkt_info *pkt)
405 {
406 	unsigned int length = reth_len(pkt);
407 
408 	qp->resp.va = reth_va(pkt);
409 	qp->resp.offset = 0;
410 	qp->resp.resid = length;
411 	qp->resp.length = length;
412 	if (pkt->mask & RXE_READ_OR_WRITE_MASK && length == 0)
413 		qp->resp.rkey = 0;
414 	else
415 		qp->resp.rkey = reth_rkey(pkt);
416 }
417 
418 static void qp_resp_from_atmeth(struct rxe_qp *qp, struct rxe_pkt_info *pkt)
419 {
420 	qp->resp.va = atmeth_va(pkt);
421 	qp->resp.offset = 0;
422 	qp->resp.rkey = atmeth_rkey(pkt);
423 	qp->resp.resid = sizeof(u64);
424 }
425 
426 /* resolve the packet rkey to qp->resp.mr or set qp->resp.mr to NULL
427  * if an invalid rkey is received or the rdma length is zero. For middle
428  * or last packets use the stored value of mr.
429  */
430 static enum resp_states check_rkey(struct rxe_qp *qp,
431 				   struct rxe_pkt_info *pkt)
432 {
433 	struct rxe_mr *mr = NULL;
434 	struct rxe_mw *mw = NULL;
435 	u64 va;
436 	u32 rkey;
437 	u32 resid;
438 	u32 pktlen;
439 	int mtu = qp->mtu;
440 	enum resp_states state;
441 	int access = 0;
442 
443 	/* parse RETH or ATMETH header for first/only packets
444 	 * for va, length, rkey, etc. or use current value for
445 	 * middle/last packets.
446 	 */
447 	if (pkt->mask & (RXE_READ_OR_WRITE_MASK | RXE_ATOMIC_WRITE_MASK)) {
448 		if (pkt->mask & RXE_RETH_MASK)
449 			qp_resp_from_reth(qp, pkt);
450 
451 		access = (pkt->mask & RXE_READ_MASK) ? IB_ACCESS_REMOTE_READ
452 						     : IB_ACCESS_REMOTE_WRITE;
453 	} else if (pkt->mask & RXE_FLUSH_MASK) {
454 		u32 flush_type = feth_plt(pkt);
455 
456 		if (pkt->mask & RXE_RETH_MASK)
457 			qp_resp_from_reth(qp, pkt);
458 
459 		if (flush_type & IB_FLUSH_GLOBAL)
460 			access |= IB_ACCESS_FLUSH_GLOBAL;
461 		if (flush_type & IB_FLUSH_PERSISTENT)
462 			access |= IB_ACCESS_FLUSH_PERSISTENT;
463 	} else if (pkt->mask & RXE_ATOMIC_MASK) {
464 		qp_resp_from_atmeth(qp, pkt);
465 		access = IB_ACCESS_REMOTE_ATOMIC;
466 	} else {
467 		/* shouldn't happen */
468 		WARN_ON(1);
469 	}
470 
471 	/* A zero-byte read or write op is not required to
472 	 * set an addr or rkey. See C9-88
473 	 */
474 	if ((pkt->mask & RXE_READ_OR_WRITE_MASK) &&
475 	    (pkt->mask & RXE_RETH_MASK) && reth_len(pkt) == 0) {
476 		qp->resp.mr = NULL;
477 		return RESPST_EXECUTE;
478 	}
479 
480 	va	= qp->resp.va;
481 	rkey	= qp->resp.rkey;
482 	resid	= qp->resp.resid;
483 	pktlen	= payload_size(pkt);
484 
485 	if (rkey_is_mw(rkey)) {
486 		mw = rxe_lookup_mw(qp, access, rkey);
487 		if (!mw) {
488 			rxe_dbg_qp(qp, "no MW matches rkey %#x\n", rkey);
489 			state = RESPST_ERR_RKEY_VIOLATION;
490 			goto err;
491 		}
492 
493 		mr = mw->mr;
494 		if (!mr) {
495 			rxe_dbg_qp(qp, "MW doesn't have an MR\n");
496 			state = RESPST_ERR_RKEY_VIOLATION;
497 			goto err;
498 		}
499 
500 		if (mw->access & IB_ZERO_BASED)
501 			qp->resp.offset = mw->addr;
502 
503 		rxe_get(mr);
504 		rxe_put(mw);
505 		mw = NULL;
506 	} else {
507 		mr = lookup_mr(qp->pd, access, rkey, RXE_LOOKUP_REMOTE);
508 		if (!mr) {
509 			rxe_dbg_qp(qp, "no MR matches rkey %#x\n", rkey);
510 			state = RESPST_ERR_RKEY_VIOLATION;
511 			goto err;
512 		}
513 	}
514 
515 	if (pkt->mask & RXE_FLUSH_MASK) {
516 		/* FLUSH MR may not set va or resid
517 		 * no need to check range since we will flush whole mr
518 		 */
519 		if (feth_sel(pkt) == IB_FLUSH_MR)
520 			goto skip_check_range;
521 	}
522 
523 	if (mr_check_range(mr, va + qp->resp.offset, resid)) {
524 		state = RESPST_ERR_RKEY_VIOLATION;
525 		goto err;
526 	}
527 
528 skip_check_range:
529 	if (pkt->mask & (RXE_WRITE_MASK | RXE_ATOMIC_WRITE_MASK)) {
530 		if (resid > mtu) {
531 			if (pktlen != mtu || bth_pad(pkt)) {
532 				state = RESPST_ERR_LENGTH;
533 				goto err;
534 			}
535 		} else {
536 			if (pktlen != resid) {
537 				state = RESPST_ERR_LENGTH;
538 				goto err;
539 			}
540 			if ((bth_pad(pkt) != (0x3 & (-resid)))) {
541 				/* This case may not be exactly that
542 				 * but nothing else fits.
543 				 */
544 				state = RESPST_ERR_LENGTH;
545 				goto err;
546 			}
547 		}
548 	}
549 
550 	WARN_ON_ONCE(qp->resp.mr);
551 
552 	qp->resp.mr = mr;
553 	return RESPST_EXECUTE;
554 
555 err:
556 	qp->resp.mr = NULL;
557 	if (mr)
558 		rxe_put(mr);
559 	if (mw)
560 		rxe_put(mw);
561 
562 	return state;
563 }
564 
565 static enum resp_states send_data_in(struct rxe_qp *qp, void *data_addr,
566 				     int data_len)
567 {
568 	int err;
569 
570 	err = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, &qp->resp.wqe->dma,
571 			data_addr, data_len, RXE_TO_MR_OBJ);
572 	if (unlikely(err))
573 		return (err == -ENOSPC) ? RESPST_ERR_LENGTH
574 					: RESPST_ERR_MALFORMED_WQE;
575 
576 	return RESPST_NONE;
577 }
578 
579 static enum resp_states write_data_in(struct rxe_qp *qp,
580 				      struct rxe_pkt_info *pkt)
581 {
582 	enum resp_states rc = RESPST_NONE;
583 	int	err;
584 	int data_len = payload_size(pkt);
585 
586 	err = rxe_mr_copy(qp->resp.mr, qp->resp.va + qp->resp.offset,
587 			  payload_addr(pkt), data_len, RXE_TO_MR_OBJ);
588 	if (err) {
589 		rc = RESPST_ERR_RKEY_VIOLATION;
590 		goto out;
591 	}
592 
593 	qp->resp.va += data_len;
594 	qp->resp.resid -= data_len;
595 
596 out:
597 	return rc;
598 }
599 
600 static struct resp_res *rxe_prepare_res(struct rxe_qp *qp,
601 					struct rxe_pkt_info *pkt,
602 					int type)
603 {
604 	struct resp_res *res;
605 	u32 pkts;
606 
607 	res = &qp->resp.resources[qp->resp.res_head];
608 	rxe_advance_resp_resource(qp);
609 	free_rd_atomic_resource(res);
610 
611 	res->type = type;
612 	res->replay = 0;
613 
614 	switch (type) {
615 	case RXE_READ_MASK:
616 		res->read.va = qp->resp.va + qp->resp.offset;
617 		res->read.va_org = qp->resp.va + qp->resp.offset;
618 		res->read.resid = qp->resp.resid;
619 		res->read.length = qp->resp.resid;
620 		res->read.rkey = qp->resp.rkey;
621 
622 		pkts = max_t(u32, (reth_len(pkt) + qp->mtu - 1)/qp->mtu, 1);
623 		res->first_psn = pkt->psn;
624 		res->cur_psn = pkt->psn;
625 		res->last_psn = (pkt->psn + pkts - 1) & BTH_PSN_MASK;
626 
627 		res->state = rdatm_res_state_new;
628 		break;
629 	case RXE_ATOMIC_MASK:
630 	case RXE_ATOMIC_WRITE_MASK:
631 		res->first_psn = pkt->psn;
632 		res->last_psn = pkt->psn;
633 		res->cur_psn = pkt->psn;
634 		break;
635 	case RXE_FLUSH_MASK:
636 		res->flush.va = qp->resp.va + qp->resp.offset;
637 		res->flush.length = qp->resp.length;
638 		res->flush.type = feth_plt(pkt);
639 		res->flush.level = feth_sel(pkt);
640 	}
641 
642 	return res;
643 }
644 
645 static enum resp_states process_flush(struct rxe_qp *qp,
646 				       struct rxe_pkt_info *pkt)
647 {
648 	u64 length, start;
649 	struct rxe_mr *mr = qp->resp.mr;
650 	struct resp_res *res = qp->resp.res;
651 
652 	/* oA19-14, oA19-15 */
653 	if (res && res->replay)
654 		return RESPST_ACKNOWLEDGE;
655 	else if (!res) {
656 		res = rxe_prepare_res(qp, pkt, RXE_FLUSH_MASK);
657 		qp->resp.res = res;
658 	}
659 
660 	if (res->flush.level == IB_FLUSH_RANGE) {
661 		start = res->flush.va;
662 		length = res->flush.length;
663 	} else { /* level == IB_FLUSH_MR */
664 		start = mr->ibmr.iova;
665 		length = mr->ibmr.length;
666 	}
667 
668 	if (res->flush.type & IB_FLUSH_PERSISTENT) {
669 		if (rxe_flush_pmem_iova(mr, start, length))
670 			return RESPST_ERR_RKEY_VIOLATION;
671 		/* Make data persistent. */
672 		wmb();
673 	} else if (res->flush.type & IB_FLUSH_GLOBAL) {
674 		/* Make data global visibility. */
675 		wmb();
676 	}
677 
678 	qp->resp.msn++;
679 
680 	/* next expected psn, read handles this separately */
681 	qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
682 	qp->resp.ack_psn = qp->resp.psn;
683 
684 	qp->resp.opcode = pkt->opcode;
685 	qp->resp.status = IB_WC_SUCCESS;
686 
687 	return RESPST_ACKNOWLEDGE;
688 }
689 
690 static enum resp_states atomic_reply(struct rxe_qp *qp,
691 				     struct rxe_pkt_info *pkt)
692 {
693 	struct rxe_mr *mr = qp->resp.mr;
694 	struct resp_res *res = qp->resp.res;
695 	int err;
696 
697 	if (!res) {
698 		res = rxe_prepare_res(qp, pkt, RXE_ATOMIC_MASK);
699 		qp->resp.res = res;
700 	}
701 
702 	if (!res->replay) {
703 		u64 iova = qp->resp.va + qp->resp.offset;
704 
705 		if (is_odp_mr(mr))
706 			err = rxe_odp_atomic_op(mr, iova, pkt->opcode,
707 						atmeth_comp(pkt),
708 						atmeth_swap_add(pkt),
709 						&res->atomic.orig_val);
710 		else
711 			err = rxe_mr_do_atomic_op(mr, iova, pkt->opcode,
712 						  atmeth_comp(pkt),
713 						  atmeth_swap_add(pkt),
714 						  &res->atomic.orig_val);
715 		if (err)
716 			return err;
717 
718 		qp->resp.msn++;
719 
720 		/* next expected psn, read handles this separately */
721 		qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
722 		qp->resp.ack_psn = qp->resp.psn;
723 
724 		qp->resp.opcode = pkt->opcode;
725 		qp->resp.status = IB_WC_SUCCESS;
726 	}
727 
728 	return RESPST_ACKNOWLEDGE;
729 }
730 
731 static enum resp_states atomic_write_reply(struct rxe_qp *qp,
732 					   struct rxe_pkt_info *pkt)
733 {
734 	struct resp_res *res = qp->resp.res;
735 	struct rxe_mr *mr;
736 	u64 value;
737 	u64 iova;
738 	int err;
739 
740 	if (!res) {
741 		res = rxe_prepare_res(qp, pkt, RXE_ATOMIC_WRITE_MASK);
742 		qp->resp.res = res;
743 	}
744 
745 	if (res->replay)
746 		return RESPST_ACKNOWLEDGE;
747 
748 	mr = qp->resp.mr;
749 	value = *(u64 *)payload_addr(pkt);
750 	iova = qp->resp.va + qp->resp.offset;
751 
752 	/* See IBA oA19-28 */
753 	if (unlikely(mr->state != RXE_MR_STATE_VALID)) {
754 		rxe_dbg_mr(mr, "mr not in valid state\n");
755 		return RESPST_ERR_RKEY_VIOLATION;
756 	}
757 
758 	if (is_odp_mr(mr))
759 		err = rxe_odp_do_atomic_write(mr, iova, value);
760 	else
761 		err = rxe_mr_do_atomic_write(mr, iova, value);
762 	if (err)
763 		return err;
764 
765 	qp->resp.resid = 0;
766 	qp->resp.msn++;
767 
768 	/* next expected psn, read handles this separately */
769 	qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
770 	qp->resp.ack_psn = qp->resp.psn;
771 
772 	qp->resp.opcode = pkt->opcode;
773 	qp->resp.status = IB_WC_SUCCESS;
774 
775 	return RESPST_ACKNOWLEDGE;
776 }
777 
778 static struct sk_buff *prepare_ack_packet(struct rxe_qp *qp,
779 					  struct rxe_pkt_info *ack,
780 					  int opcode,
781 					  int payload,
782 					  u32 psn,
783 					  u8 syndrome)
784 {
785 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
786 	struct sk_buff *skb;
787 	int paylen;
788 	int pad;
789 	int err;
790 
791 	/*
792 	 * allocate packet
793 	 */
794 	pad = (-payload) & 0x3;
795 	paylen = rxe_opcode[opcode].length + payload + pad + RXE_ICRC_SIZE;
796 
797 	skb = rxe_init_packet(rxe, &qp->pri_av, paylen, ack);
798 	if (!skb)
799 		return NULL;
800 
801 	ack->qp = qp;
802 	ack->opcode = opcode;
803 	ack->mask = rxe_opcode[opcode].mask;
804 	ack->paylen = paylen;
805 	ack->psn = psn;
806 
807 	bth_init(ack, opcode, 0, 0, pad, IB_DEFAULT_PKEY_FULL,
808 		 qp->attr.dest_qp_num, 0, psn);
809 
810 	if (ack->mask & RXE_AETH_MASK) {
811 		aeth_set_syn(ack, syndrome);
812 		aeth_set_msn(ack, qp->resp.msn);
813 	}
814 
815 	if (ack->mask & RXE_ATMACK_MASK)
816 		atmack_set_orig(ack, qp->resp.res->atomic.orig_val);
817 
818 	err = rxe_prepare(&qp->pri_av, ack, skb);
819 	if (err) {
820 		kfree_skb(skb);
821 		return NULL;
822 	}
823 
824 	return skb;
825 }
826 
827 /**
828  * rxe_recheck_mr - revalidate MR from rkey and get a reference
829  * @qp: the qp
830  * @rkey: the rkey
831  *
832  * This code allows the MR to be invalidated or deregistered or
833  * the MW if one was used to be invalidated or deallocated.
834  * It is assumed that the access permissions if originally good
835  * are OK and the mappings to be unchanged.
836  *
837  * TODO: If someone reregisters an MR to change its size or
838  * access permissions during the processing of an RDMA read
839  * we should kill the responder resource and complete the
840  * operation with an error.
841  *
842  * Return: mr on success else NULL
843  */
844 static struct rxe_mr *rxe_recheck_mr(struct rxe_qp *qp, u32 rkey)
845 {
846 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
847 	struct rxe_mr *mr;
848 	struct rxe_mw *mw;
849 
850 	if (rkey_is_mw(rkey)) {
851 		mw = rxe_pool_get_index(&rxe->mw_pool, rkey >> 8);
852 		if (!mw)
853 			return NULL;
854 
855 		mr = mw->mr;
856 		if (mw->rkey != rkey || mw->state != RXE_MW_STATE_VALID ||
857 		    !mr || mr->state != RXE_MR_STATE_VALID) {
858 			rxe_put(mw);
859 			return NULL;
860 		}
861 
862 		rxe_get(mr);
863 		rxe_put(mw);
864 
865 		return mr;
866 	}
867 
868 	mr = rxe_pool_get_index(&rxe->mr_pool, rkey >> 8);
869 	if (!mr)
870 		return NULL;
871 
872 	if (mr->rkey != rkey || mr->state != RXE_MR_STATE_VALID) {
873 		rxe_put(mr);
874 		return NULL;
875 	}
876 
877 	return mr;
878 }
879 
880 /* RDMA read response. If res is not NULL, then we have a current RDMA request
881  * being processed or replayed.
882  */
883 static enum resp_states read_reply(struct rxe_qp *qp,
884 				   struct rxe_pkt_info *req_pkt)
885 {
886 	struct rxe_pkt_info ack_pkt;
887 	struct sk_buff *skb;
888 	int mtu = qp->mtu;
889 	enum resp_states state;
890 	int payload;
891 	int opcode;
892 	int err;
893 	struct resp_res *res = qp->resp.res;
894 	struct rxe_mr *mr;
895 
896 	if (!res) {
897 		res = rxe_prepare_res(qp, req_pkt, RXE_READ_MASK);
898 		qp->resp.res = res;
899 	}
900 
901 	if (res->state == rdatm_res_state_new) {
902 		if (!res->replay || qp->resp.length == 0) {
903 			/* if length == 0 mr will be NULL (is ok)
904 			 * otherwise qp->resp.mr holds a ref on mr
905 			 * which we transfer to mr and drop below.
906 			 */
907 			mr = qp->resp.mr;
908 			qp->resp.mr = NULL;
909 		} else {
910 			mr = rxe_recheck_mr(qp, res->read.rkey);
911 			if (!mr)
912 				return RESPST_ERR_RKEY_VIOLATION;
913 		}
914 
915 		if (res->read.resid <= mtu)
916 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY;
917 		else
918 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST;
919 	} else {
920 		/* re-lookup mr from rkey on all later packets.
921 		 * length will be non-zero. This can fail if someone
922 		 * modifies or destroys the mr since the first packet.
923 		 */
924 		mr = rxe_recheck_mr(qp, res->read.rkey);
925 		if (!mr)
926 			return RESPST_ERR_RKEY_VIOLATION;
927 
928 		if (res->read.resid > mtu)
929 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE;
930 		else
931 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST;
932 	}
933 
934 	res->state = rdatm_res_state_next;
935 
936 	payload = min_t(int, res->read.resid, mtu);
937 
938 	skb = prepare_ack_packet(qp, &ack_pkt, opcode, payload,
939 				 res->cur_psn, AETH_ACK_UNLIMITED);
940 	if (!skb) {
941 		state = RESPST_ERR_RNR;
942 		goto err_out;
943 	}
944 
945 	err = rxe_mr_copy(mr, res->read.va, payload_addr(&ack_pkt),
946 			  payload, RXE_FROM_MR_OBJ);
947 	if (err) {
948 		kfree_skb(skb);
949 		state = RESPST_ERR_RKEY_VIOLATION;
950 		goto err_out;
951 	}
952 
953 	if (bth_pad(&ack_pkt)) {
954 		u8 *pad = payload_addr(&ack_pkt) + payload;
955 
956 		memset(pad, 0, bth_pad(&ack_pkt));
957 	}
958 
959 	/* rxe_xmit_packet always consumes the skb */
960 	err = rxe_xmit_packet(qp, &ack_pkt, skb);
961 	if (err) {
962 		state = RESPST_ERR_RNR;
963 		goto err_out;
964 	}
965 
966 	res->read.va += payload;
967 	res->read.resid -= payload;
968 	res->cur_psn = (res->cur_psn + 1) & BTH_PSN_MASK;
969 
970 	if (res->read.resid > 0) {
971 		state = RESPST_DONE;
972 	} else {
973 		qp->resp.res = NULL;
974 		if (!res->replay)
975 			qp->resp.opcode = -1;
976 		if (psn_compare(res->cur_psn, qp->resp.psn) >= 0)
977 			qp->resp.psn = res->cur_psn;
978 		state = RESPST_CLEANUP;
979 	}
980 
981 err_out:
982 	if (mr)
983 		rxe_put(mr);
984 	return state;
985 }
986 
987 static int invalidate_rkey(struct rxe_qp *qp, u32 rkey)
988 {
989 	if (rkey_is_mw(rkey))
990 		return rxe_invalidate_mw(qp, rkey);
991 	else
992 		return rxe_invalidate_mr(qp, rkey);
993 }
994 
995 /* Executes a new request. A retried request never reach that function (send
996  * and writes are discarded, and reads and atomics are retried elsewhere.
997  */
998 static enum resp_states execute(struct rxe_qp *qp, struct rxe_pkt_info *pkt)
999 {
1000 	enum resp_states err;
1001 	struct sk_buff *skb = PKT_TO_SKB(pkt);
1002 	union rdma_network_hdr hdr;
1003 
1004 	if (pkt->mask & RXE_SEND_MASK) {
1005 		if (qp_type(qp) == IB_QPT_UD ||
1006 		    qp_type(qp) == IB_QPT_GSI) {
1007 			if (skb->protocol == htons(ETH_P_IP)) {
1008 				memset(&hdr.reserved, 0,
1009 						sizeof(hdr.reserved));
1010 				memcpy(&hdr.roce4grh, ip_hdr(skb),
1011 						sizeof(hdr.roce4grh));
1012 				err = send_data_in(qp, &hdr, sizeof(hdr));
1013 			} else {
1014 				err = send_data_in(qp, ipv6_hdr(skb),
1015 						sizeof(hdr));
1016 			}
1017 			if (err)
1018 				return err;
1019 		}
1020 		err = send_data_in(qp, payload_addr(pkt), payload_size(pkt));
1021 		if (err)
1022 			return err;
1023 	} else if (pkt->mask & RXE_WRITE_MASK) {
1024 		err = write_data_in(qp, pkt);
1025 		if (err)
1026 			return err;
1027 	} else if (pkt->mask & RXE_READ_MASK) {
1028 		/* For RDMA Read we can increment the msn now. See C9-148. */
1029 		qp->resp.msn++;
1030 		return RESPST_READ_REPLY;
1031 	} else if (pkt->mask & RXE_ATOMIC_MASK) {
1032 		return RESPST_ATOMIC_REPLY;
1033 	} else if (pkt->mask & RXE_ATOMIC_WRITE_MASK) {
1034 		return RESPST_ATOMIC_WRITE_REPLY;
1035 	} else if (pkt->mask & RXE_FLUSH_MASK) {
1036 		return RESPST_PROCESS_FLUSH;
1037 	} else {
1038 		/* Unreachable */
1039 		WARN_ON_ONCE(1);
1040 	}
1041 
1042 	if (pkt->mask & RXE_IETH_MASK) {
1043 		u32 rkey = ieth_rkey(pkt);
1044 
1045 		err = invalidate_rkey(qp, rkey);
1046 		if (err)
1047 			return RESPST_ERR_INVALIDATE_RKEY;
1048 	}
1049 
1050 	if (pkt->mask & RXE_END_MASK)
1051 		/* We successfully processed this new request. */
1052 		qp->resp.msn++;
1053 
1054 	/* next expected psn, read handles this separately */
1055 	qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
1056 	qp->resp.ack_psn = qp->resp.psn;
1057 
1058 	qp->resp.opcode = pkt->opcode;
1059 	qp->resp.status = IB_WC_SUCCESS;
1060 
1061 	if (pkt->mask & RXE_COMP_MASK)
1062 		return RESPST_COMPLETE;
1063 	else if (qp_type(qp) == IB_QPT_RC)
1064 		return RESPST_ACKNOWLEDGE;
1065 	else
1066 		return RESPST_CLEANUP;
1067 }
1068 
1069 static enum resp_states do_complete(struct rxe_qp *qp,
1070 				    struct rxe_pkt_info *pkt)
1071 {
1072 	struct rxe_cqe cqe;
1073 	struct ib_wc *wc = &cqe.ibwc;
1074 	struct ib_uverbs_wc *uwc = &cqe.uibwc;
1075 	struct rxe_recv_wqe *wqe = qp->resp.wqe;
1076 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
1077 	unsigned long flags;
1078 
1079 	if (!wqe)
1080 		goto finish;
1081 
1082 	memset(&cqe, 0, sizeof(cqe));
1083 
1084 	if (qp->rcq->is_user) {
1085 		uwc->status		= qp->resp.status;
1086 		uwc->qp_num		= qp->ibqp.qp_num;
1087 		uwc->wr_id		= wqe->wr_id;
1088 	} else {
1089 		wc->status		= qp->resp.status;
1090 		wc->qp			= &qp->ibqp;
1091 		wc->wr_id		= wqe->wr_id;
1092 	}
1093 
1094 	if (wc->status == IB_WC_SUCCESS) {
1095 		rxe_counter_inc(rxe, RXE_CNT_RDMA_RECV);
1096 		wc->opcode = (pkt->mask & RXE_IMMDT_MASK &&
1097 				pkt->mask & RXE_WRITE_MASK) ?
1098 					IB_WC_RECV_RDMA_WITH_IMM : IB_WC_RECV;
1099 		wc->byte_len = (pkt->mask & RXE_IMMDT_MASK &&
1100 				pkt->mask & RXE_WRITE_MASK) ?
1101 					qp->resp.length : wqe->dma.length - wqe->dma.resid;
1102 
1103 		/* fields after byte_len are different between kernel and user
1104 		 * space
1105 		 */
1106 		if (qp->rcq->is_user) {
1107 			uwc->wc_flags = IB_WC_GRH;
1108 
1109 			if (pkt->mask & RXE_IMMDT_MASK) {
1110 				uwc->wc_flags |= IB_WC_WITH_IMM;
1111 				uwc->ex.imm_data = immdt_imm(pkt);
1112 			}
1113 
1114 			if (pkt->mask & RXE_IETH_MASK) {
1115 				uwc->wc_flags |= IB_WC_WITH_INVALIDATE;
1116 				uwc->ex.invalidate_rkey = ieth_rkey(pkt);
1117 			}
1118 
1119 			if (pkt->mask & RXE_DETH_MASK)
1120 				uwc->src_qp = deth_sqp(pkt);
1121 
1122 			uwc->port_num		= qp->attr.port_num;
1123 		} else {
1124 			struct sk_buff *skb = PKT_TO_SKB(pkt);
1125 
1126 			wc->wc_flags = IB_WC_GRH | IB_WC_WITH_NETWORK_HDR_TYPE;
1127 			if (skb->protocol == htons(ETH_P_IP))
1128 				wc->network_hdr_type = RDMA_NETWORK_IPV4;
1129 			else
1130 				wc->network_hdr_type = RDMA_NETWORK_IPV6;
1131 
1132 			if (is_vlan_dev(skb->dev)) {
1133 				wc->wc_flags |= IB_WC_WITH_VLAN;
1134 				wc->vlan_id = vlan_dev_vlan_id(skb->dev);
1135 			}
1136 
1137 			if (pkt->mask & RXE_IMMDT_MASK) {
1138 				wc->wc_flags |= IB_WC_WITH_IMM;
1139 				wc->ex.imm_data = immdt_imm(pkt);
1140 			}
1141 
1142 			if (pkt->mask & RXE_IETH_MASK) {
1143 				wc->wc_flags |= IB_WC_WITH_INVALIDATE;
1144 				wc->ex.invalidate_rkey = ieth_rkey(pkt);
1145 			}
1146 
1147 			if (pkt->mask & RXE_DETH_MASK)
1148 				wc->src_qp = deth_sqp(pkt);
1149 
1150 			wc->port_num		= qp->attr.port_num;
1151 		}
1152 	} else {
1153 		if (wc->status != IB_WC_WR_FLUSH_ERR)
1154 			rxe_err_qp(qp, "non-flush error status = %d\n",
1155 				wc->status);
1156 	}
1157 
1158 	/* have copy for srq and reference for !srq */
1159 	if (!qp->srq)
1160 		queue_advance_consumer(qp->rq.queue, QUEUE_TYPE_FROM_CLIENT);
1161 
1162 	qp->resp.wqe = NULL;
1163 
1164 	if (rxe_cq_post(qp->rcq, &cqe, pkt ? bth_se(pkt) : 1))
1165 		return RESPST_ERR_CQ_OVERFLOW;
1166 
1167 finish:
1168 	spin_lock_irqsave(&qp->state_lock, flags);
1169 	if (unlikely(qp_state(qp) == IB_QPS_ERR)) {
1170 		spin_unlock_irqrestore(&qp->state_lock, flags);
1171 		return RESPST_CHK_RESOURCE;
1172 	}
1173 	spin_unlock_irqrestore(&qp->state_lock, flags);
1174 
1175 	if (unlikely(!pkt))
1176 		return RESPST_DONE;
1177 	if (qp_type(qp) == IB_QPT_RC)
1178 		return RESPST_ACKNOWLEDGE;
1179 	else
1180 		return RESPST_CLEANUP;
1181 }
1182 
1183 
1184 static int send_common_ack(struct rxe_qp *qp, u8 syndrome, u32 psn,
1185 				  int opcode, const char *msg)
1186 {
1187 	int err;
1188 	struct rxe_pkt_info ack_pkt;
1189 	struct sk_buff *skb;
1190 
1191 	skb = prepare_ack_packet(qp, &ack_pkt, opcode, 0, psn, syndrome);
1192 	if (!skb)
1193 		return -ENOMEM;
1194 
1195 	err = rxe_xmit_packet(qp, &ack_pkt, skb);
1196 	if (err)
1197 		rxe_dbg_qp(qp, "Failed sending %s\n", msg);
1198 
1199 	return err;
1200 }
1201 
1202 static int send_ack(struct rxe_qp *qp, u8 syndrome, u32 psn)
1203 {
1204 	return send_common_ack(qp, syndrome, psn,
1205 			IB_OPCODE_RC_ACKNOWLEDGE, "ACK");
1206 }
1207 
1208 static int send_atomic_ack(struct rxe_qp *qp, u8 syndrome, u32 psn)
1209 {
1210 	int ret = send_common_ack(qp, syndrome, psn,
1211 			IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE, "ATOMIC ACK");
1212 
1213 	/* have to clear this since it is used to trigger
1214 	 * long read replies
1215 	 */
1216 	qp->resp.res = NULL;
1217 	return ret;
1218 }
1219 
1220 static int send_read_response_ack(struct rxe_qp *qp, u8 syndrome, u32 psn)
1221 {
1222 	int ret = send_common_ack(qp, syndrome, psn,
1223 			IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY,
1224 			"RDMA READ response of length zero ACK");
1225 
1226 	/* have to clear this since it is used to trigger
1227 	 * long read replies
1228 	 */
1229 	qp->resp.res = NULL;
1230 	return ret;
1231 }
1232 
1233 static enum resp_states acknowledge(struct rxe_qp *qp,
1234 				    struct rxe_pkt_info *pkt)
1235 {
1236 	if (qp_type(qp) != IB_QPT_RC)
1237 		return RESPST_CLEANUP;
1238 
1239 	if (qp->resp.aeth_syndrome != AETH_ACK_UNLIMITED)
1240 		send_ack(qp, qp->resp.aeth_syndrome, pkt->psn);
1241 	else if (pkt->mask & RXE_ATOMIC_MASK)
1242 		send_atomic_ack(qp, AETH_ACK_UNLIMITED, pkt->psn);
1243 	else if (pkt->mask & (RXE_FLUSH_MASK | RXE_ATOMIC_WRITE_MASK))
1244 		send_read_response_ack(qp, AETH_ACK_UNLIMITED, pkt->psn);
1245 	else if (bth_ack(pkt))
1246 		send_ack(qp, AETH_ACK_UNLIMITED, pkt->psn);
1247 
1248 	return RESPST_CLEANUP;
1249 }
1250 
1251 static enum resp_states cleanup(struct rxe_qp *qp,
1252 				struct rxe_pkt_info *pkt)
1253 {
1254 	struct sk_buff *skb;
1255 
1256 	if (pkt) {
1257 		skb = skb_dequeue(&qp->req_pkts);
1258 		rxe_put(qp);
1259 		kfree_skb(skb);
1260 		ib_device_put(qp->ibqp.device);
1261 	}
1262 
1263 	if (qp->resp.mr) {
1264 		rxe_put(qp->resp.mr);
1265 		qp->resp.mr = NULL;
1266 	}
1267 
1268 	return RESPST_DONE;
1269 }
1270 
1271 static struct resp_res *find_resource(struct rxe_qp *qp, u32 psn)
1272 {
1273 	int i;
1274 
1275 	for (i = 0; i < qp->attr.max_dest_rd_atomic; i++) {
1276 		struct resp_res *res = &qp->resp.resources[i];
1277 
1278 		if (res->type == 0)
1279 			continue;
1280 
1281 		if (psn_compare(psn, res->first_psn) >= 0 &&
1282 		    psn_compare(psn, res->last_psn) <= 0) {
1283 			return res;
1284 		}
1285 	}
1286 
1287 	return NULL;
1288 }
1289 
1290 static enum resp_states duplicate_request(struct rxe_qp *qp,
1291 					  struct rxe_pkt_info *pkt)
1292 {
1293 	enum resp_states rc;
1294 	u32 prev_psn = (qp->resp.ack_psn - 1) & BTH_PSN_MASK;
1295 
1296 	if (pkt->mask & RXE_SEND_MASK ||
1297 	    pkt->mask & RXE_WRITE_MASK) {
1298 		/* SEND. Ack again and cleanup. C9-105. */
1299 		send_ack(qp, AETH_ACK_UNLIMITED, prev_psn);
1300 		return RESPST_CLEANUP;
1301 	} else if (pkt->mask & RXE_FLUSH_MASK) {
1302 		struct resp_res *res;
1303 
1304 		/* Find the operation in our list of responder resources. */
1305 		res = find_resource(qp, pkt->psn);
1306 		if (res) {
1307 			res->replay = 1;
1308 			res->cur_psn = pkt->psn;
1309 			qp->resp.res = res;
1310 			rc = RESPST_PROCESS_FLUSH;
1311 			goto out;
1312 		}
1313 
1314 		/* Resource not found. Class D error. Drop the request. */
1315 		rc = RESPST_CLEANUP;
1316 		goto out;
1317 	} else if (pkt->mask & RXE_READ_MASK) {
1318 		struct resp_res *res;
1319 
1320 		res = find_resource(qp, pkt->psn);
1321 		if (!res) {
1322 			/* Resource not found. Class D error.  Drop the
1323 			 * request.
1324 			 */
1325 			rc = RESPST_CLEANUP;
1326 			goto out;
1327 		} else {
1328 			/* Ensure this new request is the same as the previous
1329 			 * one or a subset of it.
1330 			 */
1331 			u64 iova = reth_va(pkt);
1332 			u32 resid = reth_len(pkt);
1333 
1334 			if (iova < res->read.va_org ||
1335 			    resid > res->read.length ||
1336 			    (iova + resid) > (res->read.va_org +
1337 					      res->read.length)) {
1338 				rc = RESPST_CLEANUP;
1339 				goto out;
1340 			}
1341 
1342 			if (reth_rkey(pkt) != res->read.rkey) {
1343 				rc = RESPST_CLEANUP;
1344 				goto out;
1345 			}
1346 
1347 			res->cur_psn = pkt->psn;
1348 			res->state = (pkt->psn == res->first_psn) ?
1349 					rdatm_res_state_new :
1350 					rdatm_res_state_replay;
1351 			res->replay = 1;
1352 
1353 			/* Reset the resource, except length. */
1354 			res->read.va_org = iova;
1355 			res->read.va = iova;
1356 			res->read.resid = resid;
1357 
1358 			/* Replay the RDMA read reply. */
1359 			qp->resp.res = res;
1360 			rc = RESPST_READ_REPLY;
1361 			goto out;
1362 		}
1363 	} else {
1364 		struct resp_res *res;
1365 
1366 		/* Find the operation in our list of responder resources. */
1367 		res = find_resource(qp, pkt->psn);
1368 		if (res) {
1369 			res->replay = 1;
1370 			res->cur_psn = pkt->psn;
1371 			qp->resp.res = res;
1372 			rc = pkt->mask & RXE_ATOMIC_MASK ?
1373 					RESPST_ATOMIC_REPLY :
1374 					RESPST_ATOMIC_WRITE_REPLY;
1375 			goto out;
1376 		}
1377 
1378 		/* Resource not found. Class D error. Drop the request. */
1379 		rc = RESPST_CLEANUP;
1380 		goto out;
1381 	}
1382 out:
1383 	return rc;
1384 }
1385 
1386 /* Process a class A or C. Both are treated the same in this implementation. */
1387 static void do_class_ac_error(struct rxe_qp *qp, u8 syndrome,
1388 			      enum ib_wc_status status)
1389 {
1390 	qp->resp.aeth_syndrome	= syndrome;
1391 	qp->resp.status		= status;
1392 
1393 	/* indicate that we should go through the ERROR state */
1394 	qp->resp.goto_error	= 1;
1395 }
1396 
1397 static enum resp_states do_class_d1e_error(struct rxe_qp *qp)
1398 {
1399 	/* UC */
1400 	if (qp->srq) {
1401 		/* Class E */
1402 		qp->resp.drop_msg = 1;
1403 		if (qp->resp.wqe) {
1404 			qp->resp.status = IB_WC_REM_INV_REQ_ERR;
1405 			return RESPST_COMPLETE;
1406 		} else {
1407 			return RESPST_CLEANUP;
1408 		}
1409 	} else {
1410 		/* Class D1. This packet may be the start of a
1411 		 * new message and could be valid. The previous
1412 		 * message is invalid and ignored. reset the
1413 		 * recv wr to its original state
1414 		 */
1415 		if (qp->resp.wqe) {
1416 			qp->resp.wqe->dma.resid = qp->resp.wqe->dma.length;
1417 			qp->resp.wqe->dma.cur_sge = 0;
1418 			qp->resp.wqe->dma.sge_offset = 0;
1419 			qp->resp.opcode = -1;
1420 		}
1421 
1422 		if (qp->resp.mr) {
1423 			rxe_put(qp->resp.mr);
1424 			qp->resp.mr = NULL;
1425 		}
1426 
1427 		return RESPST_CLEANUP;
1428 	}
1429 }
1430 
1431 /* drain incoming request packet queue */
1432 static void drain_req_pkts(struct rxe_qp *qp)
1433 {
1434 	struct sk_buff *skb;
1435 
1436 	while ((skb = skb_dequeue(&qp->req_pkts))) {
1437 		rxe_put(qp);
1438 		kfree_skb(skb);
1439 		ib_device_put(qp->ibqp.device);
1440 	}
1441 }
1442 
1443 /* complete receive wqe with flush error */
1444 static int flush_recv_wqe(struct rxe_qp *qp, struct rxe_recv_wqe *wqe)
1445 {
1446 	struct rxe_cqe cqe = {};
1447 	struct ib_wc *wc = &cqe.ibwc;
1448 	struct ib_uverbs_wc *uwc = &cqe.uibwc;
1449 	int err;
1450 
1451 	if (qp->rcq->is_user) {
1452 		uwc->wr_id = wqe->wr_id;
1453 		uwc->status = IB_WC_WR_FLUSH_ERR;
1454 		uwc->qp_num = qp_num(qp);
1455 	} else {
1456 		wc->wr_id = wqe->wr_id;
1457 		wc->status = IB_WC_WR_FLUSH_ERR;
1458 		wc->qp = &qp->ibqp;
1459 	}
1460 
1461 	err = rxe_cq_post(qp->rcq, &cqe, 0);
1462 	if (err)
1463 		rxe_dbg_cq(qp->rcq, "post cq failed err = %d\n", err);
1464 
1465 	return err;
1466 }
1467 
1468 /* drain and optionally complete the recive queue
1469  * if unable to complete a wqe stop completing and
1470  * just flush the remaining wqes
1471  */
1472 static void flush_recv_queue(struct rxe_qp *qp, bool notify)
1473 {
1474 	struct rxe_queue *q = qp->rq.queue;
1475 	struct rxe_recv_wqe *wqe;
1476 	int err;
1477 
1478 	if (qp->srq) {
1479 		if (notify && qp->ibqp.event_handler) {
1480 			struct ib_event ev;
1481 
1482 			ev.device = qp->ibqp.device;
1483 			ev.element.qp = &qp->ibqp;
1484 			ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
1485 			qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
1486 		}
1487 		return;
1488 	}
1489 
1490 	/* recv queue not created. nothing to do. */
1491 	if (!qp->rq.queue)
1492 		return;
1493 
1494 	while ((wqe = queue_head(q, q->type))) {
1495 		if (notify) {
1496 			err = flush_recv_wqe(qp, wqe);
1497 			if (err)
1498 				notify = 0;
1499 		}
1500 		queue_advance_consumer(q, q->type);
1501 	}
1502 
1503 	qp->resp.wqe = NULL;
1504 }
1505 
1506 int rxe_receiver(struct rxe_qp *qp)
1507 {
1508 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
1509 	enum resp_states state;
1510 	struct rxe_pkt_info *pkt = NULL;
1511 	int ret;
1512 	unsigned long flags;
1513 
1514 	spin_lock_irqsave(&qp->state_lock, flags);
1515 	if (!qp->valid || qp_state(qp) == IB_QPS_ERR ||
1516 			  qp_state(qp) == IB_QPS_RESET) {
1517 		bool notify = qp->valid && (qp_state(qp) == IB_QPS_ERR);
1518 
1519 		drain_req_pkts(qp);
1520 		flush_recv_queue(qp, notify);
1521 		spin_unlock_irqrestore(&qp->state_lock, flags);
1522 		goto exit;
1523 	}
1524 	spin_unlock_irqrestore(&qp->state_lock, flags);
1525 
1526 	qp->resp.aeth_syndrome = AETH_ACK_UNLIMITED;
1527 
1528 	state = RESPST_GET_REQ;
1529 
1530 	while (1) {
1531 		rxe_dbg_qp(qp, "state = %s\n", resp_state_name[state]);
1532 		switch (state) {
1533 		case RESPST_GET_REQ:
1534 			state = get_req(qp, &pkt);
1535 			break;
1536 		case RESPST_CHK_PSN:
1537 			state = check_psn(qp, pkt);
1538 			break;
1539 		case RESPST_CHK_OP_SEQ:
1540 			state = check_op_seq(qp, pkt);
1541 			break;
1542 		case RESPST_CHK_OP_VALID:
1543 			state = check_op_valid(qp, pkt);
1544 			break;
1545 		case RESPST_CHK_RESOURCE:
1546 			state = check_resource(qp, pkt);
1547 			break;
1548 		case RESPST_CHK_LENGTH:
1549 			state = rxe_resp_check_length(qp, pkt);
1550 			break;
1551 		case RESPST_CHK_RKEY:
1552 			state = check_rkey(qp, pkt);
1553 			break;
1554 		case RESPST_EXECUTE:
1555 			state = execute(qp, pkt);
1556 			break;
1557 		case RESPST_COMPLETE:
1558 			state = do_complete(qp, pkt);
1559 			break;
1560 		case RESPST_READ_REPLY:
1561 			state = read_reply(qp, pkt);
1562 			break;
1563 		case RESPST_ATOMIC_REPLY:
1564 			state = atomic_reply(qp, pkt);
1565 			break;
1566 		case RESPST_ATOMIC_WRITE_REPLY:
1567 			state = atomic_write_reply(qp, pkt);
1568 			break;
1569 		case RESPST_PROCESS_FLUSH:
1570 			state = process_flush(qp, pkt);
1571 			break;
1572 		case RESPST_ACKNOWLEDGE:
1573 			state = acknowledge(qp, pkt);
1574 			break;
1575 		case RESPST_CLEANUP:
1576 			state = cleanup(qp, pkt);
1577 			break;
1578 		case RESPST_DUPLICATE_REQUEST:
1579 			state = duplicate_request(qp, pkt);
1580 			break;
1581 		case RESPST_ERR_PSN_OUT_OF_SEQ:
1582 			/* RC only - Class B. Drop packet. */
1583 			send_ack(qp, AETH_NAK_PSN_SEQ_ERROR, qp->resp.psn);
1584 			state = RESPST_CLEANUP;
1585 			break;
1586 
1587 		case RESPST_ERR_TOO_MANY_RDMA_ATM_REQ:
1588 		case RESPST_ERR_MISSING_OPCODE_FIRST:
1589 		case RESPST_ERR_MISSING_OPCODE_LAST_C:
1590 		case RESPST_ERR_UNSUPPORTED_OPCODE:
1591 		case RESPST_ERR_MISALIGNED_ATOMIC:
1592 			/* RC Only - Class C. */
1593 			do_class_ac_error(qp, AETH_NAK_INVALID_REQ,
1594 					  IB_WC_REM_INV_REQ_ERR);
1595 			state = RESPST_COMPLETE;
1596 			break;
1597 
1598 		case RESPST_ERR_MISSING_OPCODE_LAST_D1E:
1599 			state = do_class_d1e_error(qp);
1600 			break;
1601 		case RESPST_ERR_RNR:
1602 			if (qp_type(qp) == IB_QPT_RC) {
1603 				rxe_counter_inc(rxe, RXE_CNT_SND_RNR);
1604 				/* RC - class B */
1605 				send_ack(qp, AETH_RNR_NAK |
1606 					 (~AETH_TYPE_MASK &
1607 					 qp->attr.min_rnr_timer),
1608 					 pkt->psn);
1609 			} else {
1610 				/* UD/UC - class D */
1611 				qp->resp.drop_msg = 1;
1612 			}
1613 			state = RESPST_CLEANUP;
1614 			break;
1615 
1616 		case RESPST_ERR_RKEY_VIOLATION:
1617 			if (qp_type(qp) == IB_QPT_RC) {
1618 				/* Class C */
1619 				do_class_ac_error(qp, AETH_NAK_REM_ACC_ERR,
1620 						  IB_WC_REM_ACCESS_ERR);
1621 				state = RESPST_COMPLETE;
1622 			} else {
1623 				qp->resp.drop_msg = 1;
1624 				if (qp->srq) {
1625 					/* UC/SRQ Class D */
1626 					qp->resp.status = IB_WC_REM_ACCESS_ERR;
1627 					state = RESPST_COMPLETE;
1628 				} else {
1629 					/* UC/non-SRQ Class E. */
1630 					state = RESPST_CLEANUP;
1631 				}
1632 			}
1633 			break;
1634 
1635 		case RESPST_ERR_INVALIDATE_RKEY:
1636 			/* RC - Class J. */
1637 			qp->resp.goto_error = 1;
1638 			qp->resp.status = IB_WC_REM_INV_REQ_ERR;
1639 			state = RESPST_COMPLETE;
1640 			break;
1641 
1642 		case RESPST_ERR_LENGTH:
1643 			if (qp_type(qp) == IB_QPT_RC) {
1644 				/* Class C */
1645 				do_class_ac_error(qp, AETH_NAK_INVALID_REQ,
1646 						  IB_WC_REM_INV_REQ_ERR);
1647 				state = RESPST_COMPLETE;
1648 			} else if (qp->srq) {
1649 				/* UC/UD - class E */
1650 				qp->resp.status = IB_WC_REM_INV_REQ_ERR;
1651 				state = RESPST_COMPLETE;
1652 			} else {
1653 				/* UC/UD - class D */
1654 				qp->resp.drop_msg = 1;
1655 				state = RESPST_CLEANUP;
1656 			}
1657 			break;
1658 
1659 		case RESPST_ERR_MALFORMED_WQE:
1660 			/* All, Class A. */
1661 			do_class_ac_error(qp, AETH_NAK_REM_OP_ERR,
1662 					  IB_WC_LOC_QP_OP_ERR);
1663 			state = RESPST_COMPLETE;
1664 			break;
1665 
1666 		case RESPST_ERR_CQ_OVERFLOW:
1667 			/* All - Class G */
1668 			state = RESPST_ERROR;
1669 			break;
1670 
1671 		case RESPST_DONE:
1672 			if (qp->resp.goto_error) {
1673 				state = RESPST_ERROR;
1674 				break;
1675 			}
1676 
1677 			goto done;
1678 
1679 		case RESPST_EXIT:
1680 			if (qp->resp.goto_error) {
1681 				state = RESPST_ERROR;
1682 				break;
1683 			}
1684 
1685 			goto exit;
1686 
1687 		case RESPST_ERROR:
1688 			qp->resp.goto_error = 0;
1689 			rxe_dbg_qp(qp, "moved to error state\n");
1690 			rxe_qp_error(qp);
1691 			goto exit;
1692 
1693 		default:
1694 			WARN_ON_ONCE(1);
1695 		}
1696 	}
1697 
1698 	/* A non-zero return value will cause rxe_do_task to
1699 	 * exit its loop and end the work item. A zero return
1700 	 * will continue looping and return to rxe_responder
1701 	 */
1702 done:
1703 	ret = 0;
1704 	goto out;
1705 exit:
1706 	ret = -EAGAIN;
1707 out:
1708 	return ret;
1709 }
1710