1 /*
2  * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
3  * Copyright (c) 2015 System Fabric Works, 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 <linux/skbuff.h>
35 
36 #include "rxe.h"
37 #include "rxe_loc.h"
38 #include "rxe_queue.h"
39 
40 enum resp_states {
41 	RESPST_NONE,
42 	RESPST_GET_REQ,
43 	RESPST_CHK_PSN,
44 	RESPST_CHK_OP_SEQ,
45 	RESPST_CHK_OP_VALID,
46 	RESPST_CHK_RESOURCE,
47 	RESPST_CHK_LENGTH,
48 	RESPST_CHK_RKEY,
49 	RESPST_EXECUTE,
50 	RESPST_READ_REPLY,
51 	RESPST_COMPLETE,
52 	RESPST_ACKNOWLEDGE,
53 	RESPST_CLEANUP,
54 	RESPST_DUPLICATE_REQUEST,
55 	RESPST_ERR_MALFORMED_WQE,
56 	RESPST_ERR_UNSUPPORTED_OPCODE,
57 	RESPST_ERR_MISALIGNED_ATOMIC,
58 	RESPST_ERR_PSN_OUT_OF_SEQ,
59 	RESPST_ERR_MISSING_OPCODE_FIRST,
60 	RESPST_ERR_MISSING_OPCODE_LAST_C,
61 	RESPST_ERR_MISSING_OPCODE_LAST_D1E,
62 	RESPST_ERR_TOO_MANY_RDMA_ATM_REQ,
63 	RESPST_ERR_RNR,
64 	RESPST_ERR_RKEY_VIOLATION,
65 	RESPST_ERR_LENGTH,
66 	RESPST_ERR_CQ_OVERFLOW,
67 	RESPST_ERROR,
68 	RESPST_RESET,
69 	RESPST_DONE,
70 	RESPST_EXIT,
71 };
72 
73 static char *resp_state_name[] = {
74 	[RESPST_NONE]				= "NONE",
75 	[RESPST_GET_REQ]			= "GET_REQ",
76 	[RESPST_CHK_PSN]			= "CHK_PSN",
77 	[RESPST_CHK_OP_SEQ]			= "CHK_OP_SEQ",
78 	[RESPST_CHK_OP_VALID]			= "CHK_OP_VALID",
79 	[RESPST_CHK_RESOURCE]			= "CHK_RESOURCE",
80 	[RESPST_CHK_LENGTH]			= "CHK_LENGTH",
81 	[RESPST_CHK_RKEY]			= "CHK_RKEY",
82 	[RESPST_EXECUTE]			= "EXECUTE",
83 	[RESPST_READ_REPLY]			= "READ_REPLY",
84 	[RESPST_COMPLETE]			= "COMPLETE",
85 	[RESPST_ACKNOWLEDGE]			= "ACKNOWLEDGE",
86 	[RESPST_CLEANUP]			= "CLEANUP",
87 	[RESPST_DUPLICATE_REQUEST]		= "DUPLICATE_REQUEST",
88 	[RESPST_ERR_MALFORMED_WQE]		= "ERR_MALFORMED_WQE",
89 	[RESPST_ERR_UNSUPPORTED_OPCODE]		= "ERR_UNSUPPORTED_OPCODE",
90 	[RESPST_ERR_MISALIGNED_ATOMIC]		= "ERR_MISALIGNED_ATOMIC",
91 	[RESPST_ERR_PSN_OUT_OF_SEQ]		= "ERR_PSN_OUT_OF_SEQ",
92 	[RESPST_ERR_MISSING_OPCODE_FIRST]	= "ERR_MISSING_OPCODE_FIRST",
93 	[RESPST_ERR_MISSING_OPCODE_LAST_C]	= "ERR_MISSING_OPCODE_LAST_C",
94 	[RESPST_ERR_MISSING_OPCODE_LAST_D1E]	= "ERR_MISSING_OPCODE_LAST_D1E",
95 	[RESPST_ERR_TOO_MANY_RDMA_ATM_REQ]	= "ERR_TOO_MANY_RDMA_ATM_REQ",
96 	[RESPST_ERR_RNR]			= "ERR_RNR",
97 	[RESPST_ERR_RKEY_VIOLATION]		= "ERR_RKEY_VIOLATION",
98 	[RESPST_ERR_LENGTH]			= "ERR_LENGTH",
99 	[RESPST_ERR_CQ_OVERFLOW]		= "ERR_CQ_OVERFLOW",
100 	[RESPST_ERROR]				= "ERROR",
101 	[RESPST_RESET]				= "RESET",
102 	[RESPST_DONE]				= "DONE",
103 	[RESPST_EXIT]				= "EXIT",
104 };
105 
106 /* rxe_recv calls here to add a request packet to the input queue */
107 void rxe_resp_queue_pkt(struct rxe_dev *rxe, struct rxe_qp *qp,
108 			struct sk_buff *skb)
109 {
110 	int must_sched;
111 	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
112 
113 	skb_queue_tail(&qp->req_pkts, skb);
114 
115 	must_sched = (pkt->opcode == IB_OPCODE_RC_RDMA_READ_REQUEST) ||
116 			(skb_queue_len(&qp->req_pkts) > 1);
117 
118 	rxe_run_task(&qp->resp.task, must_sched);
119 }
120 
121 static inline enum resp_states get_req(struct rxe_qp *qp,
122 				       struct rxe_pkt_info **pkt_p)
123 {
124 	struct sk_buff *skb;
125 
126 	if (qp->resp.state == QP_STATE_ERROR) {
127 		skb = skb_dequeue(&qp->req_pkts);
128 		if (skb) {
129 			/* drain request packet queue */
130 			rxe_drop_ref(qp);
131 			kfree_skb(skb);
132 			return RESPST_GET_REQ;
133 		}
134 
135 		/* go drain recv wr queue */
136 		return RESPST_CHK_RESOURCE;
137 	}
138 
139 	skb = skb_peek(&qp->req_pkts);
140 	if (!skb)
141 		return RESPST_EXIT;
142 
143 	*pkt_p = SKB_TO_PKT(skb);
144 
145 	return (qp->resp.res) ? RESPST_READ_REPLY : RESPST_CHK_PSN;
146 }
147 
148 static enum resp_states check_psn(struct rxe_qp *qp,
149 				  struct rxe_pkt_info *pkt)
150 {
151 	int diff = psn_compare(pkt->psn, qp->resp.psn);
152 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
153 
154 	switch (qp_type(qp)) {
155 	case IB_QPT_RC:
156 		if (diff > 0) {
157 			if (qp->resp.sent_psn_nak)
158 				return RESPST_CLEANUP;
159 
160 			qp->resp.sent_psn_nak = 1;
161 			rxe_counter_inc(rxe, RXE_CNT_OUT_OF_SEQ_REQ);
162 			return RESPST_ERR_PSN_OUT_OF_SEQ;
163 
164 		} else if (diff < 0) {
165 			rxe_counter_inc(rxe, RXE_CNT_DUP_REQ);
166 			return RESPST_DUPLICATE_REQUEST;
167 		}
168 
169 		if (qp->resp.sent_psn_nak)
170 			qp->resp.sent_psn_nak = 0;
171 
172 		break;
173 
174 	case IB_QPT_UC:
175 		if (qp->resp.drop_msg || diff != 0) {
176 			if (pkt->mask & RXE_START_MASK) {
177 				qp->resp.drop_msg = 0;
178 				return RESPST_CHK_OP_SEQ;
179 			}
180 
181 			qp->resp.drop_msg = 1;
182 			return RESPST_CLEANUP;
183 		}
184 		break;
185 	default:
186 		break;
187 	}
188 
189 	return RESPST_CHK_OP_SEQ;
190 }
191 
192 static enum resp_states check_op_seq(struct rxe_qp *qp,
193 				     struct rxe_pkt_info *pkt)
194 {
195 	switch (qp_type(qp)) {
196 	case IB_QPT_RC:
197 		switch (qp->resp.opcode) {
198 		case IB_OPCODE_RC_SEND_FIRST:
199 		case IB_OPCODE_RC_SEND_MIDDLE:
200 			switch (pkt->opcode) {
201 			case IB_OPCODE_RC_SEND_MIDDLE:
202 			case IB_OPCODE_RC_SEND_LAST:
203 			case IB_OPCODE_RC_SEND_LAST_WITH_IMMEDIATE:
204 			case IB_OPCODE_RC_SEND_LAST_WITH_INVALIDATE:
205 				return RESPST_CHK_OP_VALID;
206 			default:
207 				return RESPST_ERR_MISSING_OPCODE_LAST_C;
208 			}
209 
210 		case IB_OPCODE_RC_RDMA_WRITE_FIRST:
211 		case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
212 			switch (pkt->opcode) {
213 			case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
214 			case IB_OPCODE_RC_RDMA_WRITE_LAST:
215 			case IB_OPCODE_RC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
216 				return RESPST_CHK_OP_VALID;
217 			default:
218 				return RESPST_ERR_MISSING_OPCODE_LAST_C;
219 			}
220 
221 		default:
222 			switch (pkt->opcode) {
223 			case IB_OPCODE_RC_SEND_MIDDLE:
224 			case IB_OPCODE_RC_SEND_LAST:
225 			case IB_OPCODE_RC_SEND_LAST_WITH_IMMEDIATE:
226 			case IB_OPCODE_RC_SEND_LAST_WITH_INVALIDATE:
227 			case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
228 			case IB_OPCODE_RC_RDMA_WRITE_LAST:
229 			case IB_OPCODE_RC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
230 				return RESPST_ERR_MISSING_OPCODE_FIRST;
231 			default:
232 				return RESPST_CHK_OP_VALID;
233 			}
234 		}
235 		break;
236 
237 	case IB_QPT_UC:
238 		switch (qp->resp.opcode) {
239 		case IB_OPCODE_UC_SEND_FIRST:
240 		case IB_OPCODE_UC_SEND_MIDDLE:
241 			switch (pkt->opcode) {
242 			case IB_OPCODE_UC_SEND_MIDDLE:
243 			case IB_OPCODE_UC_SEND_LAST:
244 			case IB_OPCODE_UC_SEND_LAST_WITH_IMMEDIATE:
245 				return RESPST_CHK_OP_VALID;
246 			default:
247 				return RESPST_ERR_MISSING_OPCODE_LAST_D1E;
248 			}
249 
250 		case IB_OPCODE_UC_RDMA_WRITE_FIRST:
251 		case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
252 			switch (pkt->opcode) {
253 			case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
254 			case IB_OPCODE_UC_RDMA_WRITE_LAST:
255 			case IB_OPCODE_UC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
256 				return RESPST_CHK_OP_VALID;
257 			default:
258 				return RESPST_ERR_MISSING_OPCODE_LAST_D1E;
259 			}
260 
261 		default:
262 			switch (pkt->opcode) {
263 			case IB_OPCODE_UC_SEND_MIDDLE:
264 			case IB_OPCODE_UC_SEND_LAST:
265 			case IB_OPCODE_UC_SEND_LAST_WITH_IMMEDIATE:
266 			case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
267 			case IB_OPCODE_UC_RDMA_WRITE_LAST:
268 			case IB_OPCODE_UC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
269 				qp->resp.drop_msg = 1;
270 				return RESPST_CLEANUP;
271 			default:
272 				return RESPST_CHK_OP_VALID;
273 			}
274 		}
275 		break;
276 
277 	default:
278 		return RESPST_CHK_OP_VALID;
279 	}
280 }
281 
282 static enum resp_states check_op_valid(struct rxe_qp *qp,
283 				       struct rxe_pkt_info *pkt)
284 {
285 	switch (qp_type(qp)) {
286 	case IB_QPT_RC:
287 		if (((pkt->mask & RXE_READ_MASK) &&
288 		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_READ)) ||
289 		    ((pkt->mask & RXE_WRITE_MASK) &&
290 		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_WRITE)) ||
291 		    ((pkt->mask & RXE_ATOMIC_MASK) &&
292 		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_ATOMIC))) {
293 			return RESPST_ERR_UNSUPPORTED_OPCODE;
294 		}
295 
296 		break;
297 
298 	case IB_QPT_UC:
299 		if ((pkt->mask & RXE_WRITE_MASK) &&
300 		    !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_WRITE)) {
301 			qp->resp.drop_msg = 1;
302 			return RESPST_CLEANUP;
303 		}
304 
305 		break;
306 
307 	case IB_QPT_UD:
308 	case IB_QPT_SMI:
309 	case IB_QPT_GSI:
310 		break;
311 
312 	default:
313 		WARN_ON_ONCE(1);
314 		break;
315 	}
316 
317 	return RESPST_CHK_RESOURCE;
318 }
319 
320 static enum resp_states get_srq_wqe(struct rxe_qp *qp)
321 {
322 	struct rxe_srq *srq = qp->srq;
323 	struct rxe_queue *q = srq->rq.queue;
324 	struct rxe_recv_wqe *wqe;
325 	struct ib_event ev;
326 
327 	if (srq->error)
328 		return RESPST_ERR_RNR;
329 
330 	spin_lock_bh(&srq->rq.consumer_lock);
331 
332 	wqe = queue_head(q);
333 	if (!wqe) {
334 		spin_unlock_bh(&srq->rq.consumer_lock);
335 		return RESPST_ERR_RNR;
336 	}
337 
338 	/* note kernel and user space recv wqes have same size */
339 	memcpy(&qp->resp.srq_wqe, wqe, sizeof(qp->resp.srq_wqe));
340 
341 	qp->resp.wqe = &qp->resp.srq_wqe.wqe;
342 	advance_consumer(q);
343 
344 	if (srq->limit && srq->ibsrq.event_handler &&
345 	    (queue_count(q) < srq->limit)) {
346 		srq->limit = 0;
347 		goto event;
348 	}
349 
350 	spin_unlock_bh(&srq->rq.consumer_lock);
351 	return RESPST_CHK_LENGTH;
352 
353 event:
354 	spin_unlock_bh(&srq->rq.consumer_lock);
355 	ev.device = qp->ibqp.device;
356 	ev.element.srq = qp->ibqp.srq;
357 	ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
358 	srq->ibsrq.event_handler(&ev, srq->ibsrq.srq_context);
359 	return RESPST_CHK_LENGTH;
360 }
361 
362 static enum resp_states check_resource(struct rxe_qp *qp,
363 				       struct rxe_pkt_info *pkt)
364 {
365 	struct rxe_srq *srq = qp->srq;
366 
367 	if (qp->resp.state == QP_STATE_ERROR) {
368 		if (qp->resp.wqe) {
369 			qp->resp.status = IB_WC_WR_FLUSH_ERR;
370 			return RESPST_COMPLETE;
371 		} else if (!srq) {
372 			qp->resp.wqe = queue_head(qp->rq.queue);
373 			if (qp->resp.wqe) {
374 				qp->resp.status = IB_WC_WR_FLUSH_ERR;
375 				return RESPST_COMPLETE;
376 			} else {
377 				return RESPST_EXIT;
378 			}
379 		} else {
380 			return RESPST_EXIT;
381 		}
382 	}
383 
384 	if (pkt->mask & RXE_READ_OR_ATOMIC) {
385 		/* it is the requesters job to not send
386 		 * too many read/atomic ops, we just
387 		 * recycle the responder resource queue
388 		 */
389 		if (likely(qp->attr.max_dest_rd_atomic > 0))
390 			return RESPST_CHK_LENGTH;
391 		else
392 			return RESPST_ERR_TOO_MANY_RDMA_ATM_REQ;
393 	}
394 
395 	if (pkt->mask & RXE_RWR_MASK) {
396 		if (srq)
397 			return get_srq_wqe(qp);
398 
399 		qp->resp.wqe = queue_head(qp->rq.queue);
400 		return (qp->resp.wqe) ? RESPST_CHK_LENGTH : RESPST_ERR_RNR;
401 	}
402 
403 	return RESPST_CHK_LENGTH;
404 }
405 
406 static enum resp_states check_length(struct rxe_qp *qp,
407 				     struct rxe_pkt_info *pkt)
408 {
409 	switch (qp_type(qp)) {
410 	case IB_QPT_RC:
411 		return RESPST_CHK_RKEY;
412 
413 	case IB_QPT_UC:
414 		return RESPST_CHK_RKEY;
415 
416 	default:
417 		return RESPST_CHK_RKEY;
418 	}
419 }
420 
421 static enum resp_states check_rkey(struct rxe_qp *qp,
422 				   struct rxe_pkt_info *pkt)
423 {
424 	struct rxe_mem *mem = NULL;
425 	u64 va;
426 	u32 rkey;
427 	u32 resid;
428 	u32 pktlen;
429 	int mtu = qp->mtu;
430 	enum resp_states state;
431 	int access;
432 
433 	if (pkt->mask & (RXE_READ_MASK | RXE_WRITE_MASK)) {
434 		if (pkt->mask & RXE_RETH_MASK) {
435 			qp->resp.va = reth_va(pkt);
436 			qp->resp.rkey = reth_rkey(pkt);
437 			qp->resp.resid = reth_len(pkt);
438 		}
439 		access = (pkt->mask & RXE_READ_MASK) ? IB_ACCESS_REMOTE_READ
440 						     : IB_ACCESS_REMOTE_WRITE;
441 	} else if (pkt->mask & RXE_ATOMIC_MASK) {
442 		qp->resp.va = atmeth_va(pkt);
443 		qp->resp.rkey = atmeth_rkey(pkt);
444 		qp->resp.resid = sizeof(u64);
445 		access = IB_ACCESS_REMOTE_ATOMIC;
446 	} else {
447 		return RESPST_EXECUTE;
448 	}
449 
450 	/* A zero-byte op is not required to set an addr or rkey. */
451 	if ((pkt->mask & (RXE_READ_MASK | RXE_WRITE_OR_SEND)) &&
452 	    (pkt->mask & RXE_RETH_MASK) &&
453 	    reth_len(pkt) == 0) {
454 		return RESPST_EXECUTE;
455 	}
456 
457 	va	= qp->resp.va;
458 	rkey	= qp->resp.rkey;
459 	resid	= qp->resp.resid;
460 	pktlen	= payload_size(pkt);
461 
462 	mem = lookup_mem(qp->pd, access, rkey, lookup_remote);
463 	if (!mem) {
464 		state = RESPST_ERR_RKEY_VIOLATION;
465 		goto err;
466 	}
467 
468 	if (unlikely(mem->state == RXE_MEM_STATE_FREE)) {
469 		state = RESPST_ERR_RKEY_VIOLATION;
470 		goto err;
471 	}
472 
473 	if (mem_check_range(mem, va, resid)) {
474 		state = RESPST_ERR_RKEY_VIOLATION;
475 		goto err;
476 	}
477 
478 	if (pkt->mask & RXE_WRITE_MASK)	 {
479 		if (resid > mtu) {
480 			if (pktlen != mtu || bth_pad(pkt)) {
481 				state = RESPST_ERR_LENGTH;
482 				goto err;
483 			}
484 		} else {
485 			if (pktlen != resid) {
486 				state = RESPST_ERR_LENGTH;
487 				goto err;
488 			}
489 			if ((bth_pad(pkt) != (0x3 & (-resid)))) {
490 				/* This case may not be exactly that
491 				 * but nothing else fits.
492 				 */
493 				state = RESPST_ERR_LENGTH;
494 				goto err;
495 			}
496 		}
497 	}
498 
499 	WARN_ON_ONCE(qp->resp.mr);
500 
501 	qp->resp.mr = mem;
502 	return RESPST_EXECUTE;
503 
504 err:
505 	if (mem)
506 		rxe_drop_ref(mem);
507 	return state;
508 }
509 
510 static enum resp_states send_data_in(struct rxe_qp *qp, void *data_addr,
511 				     int data_len)
512 {
513 	int err;
514 
515 	err = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, &qp->resp.wqe->dma,
516 			data_addr, data_len, to_mem_obj, NULL);
517 	if (unlikely(err))
518 		return (err == -ENOSPC) ? RESPST_ERR_LENGTH
519 					: RESPST_ERR_MALFORMED_WQE;
520 
521 	return RESPST_NONE;
522 }
523 
524 static enum resp_states write_data_in(struct rxe_qp *qp,
525 				      struct rxe_pkt_info *pkt)
526 {
527 	enum resp_states rc = RESPST_NONE;
528 	int	err;
529 	int data_len = payload_size(pkt);
530 
531 	err = rxe_mem_copy(qp->resp.mr, qp->resp.va, payload_addr(pkt),
532 			   data_len, to_mem_obj, NULL);
533 	if (err) {
534 		rc = RESPST_ERR_RKEY_VIOLATION;
535 		goto out;
536 	}
537 
538 	qp->resp.va += data_len;
539 	qp->resp.resid -= data_len;
540 
541 out:
542 	return rc;
543 }
544 
545 /* Guarantee atomicity of atomic operations at the machine level. */
546 static DEFINE_SPINLOCK(atomic_ops_lock);
547 
548 static enum resp_states process_atomic(struct rxe_qp *qp,
549 				       struct rxe_pkt_info *pkt)
550 {
551 	u64 iova = atmeth_va(pkt);
552 	u64 *vaddr;
553 	enum resp_states ret;
554 	struct rxe_mem *mr = qp->resp.mr;
555 
556 	if (mr->state != RXE_MEM_STATE_VALID) {
557 		ret = RESPST_ERR_RKEY_VIOLATION;
558 		goto out;
559 	}
560 
561 	vaddr = iova_to_vaddr(mr, iova, sizeof(u64));
562 
563 	/* check vaddr is 8 bytes aligned. */
564 	if (!vaddr || (uintptr_t)vaddr & 7) {
565 		ret = RESPST_ERR_MISALIGNED_ATOMIC;
566 		goto out;
567 	}
568 
569 	spin_lock_bh(&atomic_ops_lock);
570 
571 	qp->resp.atomic_orig = *vaddr;
572 
573 	if (pkt->opcode == IB_OPCODE_RC_COMPARE_SWAP ||
574 	    pkt->opcode == IB_OPCODE_RD_COMPARE_SWAP) {
575 		if (*vaddr == atmeth_comp(pkt))
576 			*vaddr = atmeth_swap_add(pkt);
577 	} else {
578 		*vaddr += atmeth_swap_add(pkt);
579 	}
580 
581 	spin_unlock_bh(&atomic_ops_lock);
582 
583 	ret = RESPST_NONE;
584 out:
585 	return ret;
586 }
587 
588 static struct sk_buff *prepare_ack_packet(struct rxe_qp *qp,
589 					  struct rxe_pkt_info *pkt,
590 					  struct rxe_pkt_info *ack,
591 					  int opcode,
592 					  int payload,
593 					  u32 psn,
594 					  u8 syndrome,
595 					  u32 *crcp)
596 {
597 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
598 	struct sk_buff *skb;
599 	u32 crc = 0;
600 	u32 *p;
601 	int paylen;
602 	int pad;
603 	int err;
604 
605 	/*
606 	 * allocate packet
607 	 */
608 	pad = (-payload) & 0x3;
609 	paylen = rxe_opcode[opcode].length + payload + pad + RXE_ICRC_SIZE;
610 
611 	skb = rxe_init_packet(rxe, &qp->pri_av, paylen, ack);
612 	if (!skb)
613 		return NULL;
614 
615 	ack->qp = qp;
616 	ack->opcode = opcode;
617 	ack->mask = rxe_opcode[opcode].mask;
618 	ack->offset = pkt->offset;
619 	ack->paylen = paylen;
620 
621 	/* fill in bth using the request packet headers */
622 	memcpy(ack->hdr, pkt->hdr, pkt->offset + RXE_BTH_BYTES);
623 
624 	bth_set_opcode(ack, opcode);
625 	bth_set_qpn(ack, qp->attr.dest_qp_num);
626 	bth_set_pad(ack, pad);
627 	bth_set_se(ack, 0);
628 	bth_set_psn(ack, psn);
629 	bth_set_ack(ack, 0);
630 	ack->psn = psn;
631 
632 	if (ack->mask & RXE_AETH_MASK) {
633 		aeth_set_syn(ack, syndrome);
634 		aeth_set_msn(ack, qp->resp.msn);
635 	}
636 
637 	if (ack->mask & RXE_ATMACK_MASK)
638 		atmack_set_orig(ack, qp->resp.atomic_orig);
639 
640 	err = rxe_prepare(rxe, ack, skb, &crc);
641 	if (err) {
642 		kfree_skb(skb);
643 		return NULL;
644 	}
645 
646 	if (crcp) {
647 		/* CRC computation will be continued by the caller */
648 		*crcp = crc;
649 	} else {
650 		p = payload_addr(ack) + payload + bth_pad(ack);
651 		*p = ~crc;
652 	}
653 
654 	return skb;
655 }
656 
657 /* RDMA read response. If res is not NULL, then we have a current RDMA request
658  * being processed or replayed.
659  */
660 static enum resp_states read_reply(struct rxe_qp *qp,
661 				   struct rxe_pkt_info *req_pkt)
662 {
663 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
664 	struct rxe_pkt_info ack_pkt;
665 	struct sk_buff *skb;
666 	int mtu = qp->mtu;
667 	enum resp_states state;
668 	int payload;
669 	int opcode;
670 	int err;
671 	struct resp_res *res = qp->resp.res;
672 	u32 icrc;
673 	u32 *p;
674 
675 	if (!res) {
676 		/* This is the first time we process that request. Get a
677 		 * resource
678 		 */
679 		res = &qp->resp.resources[qp->resp.res_head];
680 
681 		free_rd_atomic_resource(qp, res);
682 		rxe_advance_resp_resource(qp);
683 
684 		res->type		= RXE_READ_MASK;
685 
686 		res->read.va		= qp->resp.va;
687 		res->read.va_org	= qp->resp.va;
688 
689 		res->first_psn		= req_pkt->psn;
690 
691 		if (reth_len(req_pkt)) {
692 			res->last_psn	= (req_pkt->psn +
693 					   (reth_len(req_pkt) + mtu - 1) /
694 					   mtu - 1) & BTH_PSN_MASK;
695 		} else {
696 			res->last_psn	= res->first_psn;
697 		}
698 		res->cur_psn		= req_pkt->psn;
699 
700 		res->read.resid		= qp->resp.resid;
701 		res->read.length	= qp->resp.resid;
702 		res->read.rkey		= qp->resp.rkey;
703 
704 		/* note res inherits the reference to mr from qp */
705 		res->read.mr		= qp->resp.mr;
706 		qp->resp.mr		= NULL;
707 
708 		qp->resp.res		= res;
709 		res->state		= rdatm_res_state_new;
710 	}
711 
712 	if (res->state == rdatm_res_state_new) {
713 		if (res->read.resid <= mtu)
714 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY;
715 		else
716 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST;
717 	} else {
718 		if (res->read.resid > mtu)
719 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE;
720 		else
721 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST;
722 	}
723 
724 	res->state = rdatm_res_state_next;
725 
726 	payload = min_t(int, res->read.resid, mtu);
727 
728 	skb = prepare_ack_packet(qp, req_pkt, &ack_pkt, opcode, payload,
729 				 res->cur_psn, AETH_ACK_UNLIMITED, &icrc);
730 	if (!skb)
731 		return RESPST_ERR_RNR;
732 
733 	err = rxe_mem_copy(res->read.mr, res->read.va, payload_addr(&ack_pkt),
734 			   payload, from_mem_obj, &icrc);
735 	if (err)
736 		pr_err("Failed copying memory\n");
737 
738 	p = payload_addr(&ack_pkt) + payload + bth_pad(&ack_pkt);
739 	*p = ~icrc;
740 
741 	err = rxe_xmit_packet(rxe, qp, &ack_pkt, skb);
742 	if (err) {
743 		pr_err("Failed sending RDMA reply.\n");
744 		return RESPST_ERR_RNR;
745 	}
746 
747 	res->read.va += payload;
748 	res->read.resid -= payload;
749 	res->cur_psn = (res->cur_psn + 1) & BTH_PSN_MASK;
750 
751 	if (res->read.resid > 0) {
752 		state = RESPST_DONE;
753 	} else {
754 		qp->resp.res = NULL;
755 		qp->resp.opcode = -1;
756 		if (psn_compare(res->cur_psn, qp->resp.psn) >= 0)
757 			qp->resp.psn = res->cur_psn;
758 		state = RESPST_CLEANUP;
759 	}
760 
761 	return state;
762 }
763 
764 static void build_rdma_network_hdr(union rdma_network_hdr *hdr,
765 				   struct rxe_pkt_info *pkt)
766 {
767 	struct sk_buff *skb = PKT_TO_SKB(pkt);
768 
769 	memset(hdr, 0, sizeof(*hdr));
770 	if (skb->protocol == htons(ETH_P_IP))
771 		memcpy(&hdr->roce4grh, ip_hdr(skb), sizeof(hdr->roce4grh));
772 	else if (skb->protocol == htons(ETH_P_IPV6))
773 		memcpy(&hdr->ibgrh, ipv6_hdr(skb), sizeof(hdr->ibgrh));
774 }
775 
776 /* Executes a new request. A retried request never reach that function (send
777  * and writes are discarded, and reads and atomics are retried elsewhere.
778  */
779 static enum resp_states execute(struct rxe_qp *qp, struct rxe_pkt_info *pkt)
780 {
781 	enum resp_states err;
782 
783 	if (pkt->mask & RXE_SEND_MASK) {
784 		if (qp_type(qp) == IB_QPT_UD ||
785 		    qp_type(qp) == IB_QPT_SMI ||
786 		    qp_type(qp) == IB_QPT_GSI) {
787 			union rdma_network_hdr hdr;
788 
789 			build_rdma_network_hdr(&hdr, pkt);
790 
791 			err = send_data_in(qp, &hdr, sizeof(hdr));
792 			if (err)
793 				return err;
794 		}
795 		err = send_data_in(qp, payload_addr(pkt), payload_size(pkt));
796 		if (err)
797 			return err;
798 	} else if (pkt->mask & RXE_WRITE_MASK) {
799 		err = write_data_in(qp, pkt);
800 		if (err)
801 			return err;
802 	} else if (pkt->mask & RXE_READ_MASK) {
803 		/* For RDMA Read we can increment the msn now. See C9-148. */
804 		qp->resp.msn++;
805 		return RESPST_READ_REPLY;
806 	} else if (pkt->mask & RXE_ATOMIC_MASK) {
807 		err = process_atomic(qp, pkt);
808 		if (err)
809 			return err;
810 	} else {
811 		/* Unreachable */
812 		WARN_ON_ONCE(1);
813 	}
814 
815 	/* next expected psn, read handles this separately */
816 	qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
817 
818 	qp->resp.opcode = pkt->opcode;
819 	qp->resp.status = IB_WC_SUCCESS;
820 
821 	if (pkt->mask & RXE_COMP_MASK) {
822 		/* We successfully processed this new request. */
823 		qp->resp.msn++;
824 		return RESPST_COMPLETE;
825 	} else if (qp_type(qp) == IB_QPT_RC)
826 		return RESPST_ACKNOWLEDGE;
827 	else
828 		return RESPST_CLEANUP;
829 }
830 
831 static enum resp_states do_complete(struct rxe_qp *qp,
832 				    struct rxe_pkt_info *pkt)
833 {
834 	struct rxe_cqe cqe;
835 	struct ib_wc *wc = &cqe.ibwc;
836 	struct ib_uverbs_wc *uwc = &cqe.uibwc;
837 	struct rxe_recv_wqe *wqe = qp->resp.wqe;
838 
839 	if (unlikely(!wqe))
840 		return RESPST_CLEANUP;
841 
842 	memset(&cqe, 0, sizeof(cqe));
843 
844 	wc->wr_id		= wqe->wr_id;
845 	wc->status		= qp->resp.status;
846 	wc->qp			= &qp->ibqp;
847 
848 	/* fields after status are not required for errors */
849 	if (wc->status == IB_WC_SUCCESS) {
850 		wc->opcode = (pkt->mask & RXE_IMMDT_MASK &&
851 				pkt->mask & RXE_WRITE_MASK) ?
852 					IB_WC_RECV_RDMA_WITH_IMM : IB_WC_RECV;
853 		wc->vendor_err = 0;
854 		wc->byte_len = wqe->dma.length - wqe->dma.resid;
855 
856 		/* fields after byte_len are different between kernel and user
857 		 * space
858 		 */
859 		if (qp->rcq->is_user) {
860 			uwc->wc_flags = IB_WC_GRH;
861 
862 			if (pkt->mask & RXE_IMMDT_MASK) {
863 				uwc->wc_flags |= IB_WC_WITH_IMM;
864 				uwc->ex.imm_data = immdt_imm(pkt);
865 			}
866 
867 			if (pkt->mask & RXE_IETH_MASK) {
868 				uwc->wc_flags |= IB_WC_WITH_INVALIDATE;
869 				uwc->ex.invalidate_rkey = ieth_rkey(pkt);
870 			}
871 
872 			uwc->qp_num		= qp->ibqp.qp_num;
873 
874 			if (pkt->mask & RXE_DETH_MASK)
875 				uwc->src_qp = deth_sqp(pkt);
876 
877 			uwc->port_num		= qp->attr.port_num;
878 		} else {
879 			struct sk_buff *skb = PKT_TO_SKB(pkt);
880 
881 			wc->wc_flags = IB_WC_GRH | IB_WC_WITH_NETWORK_HDR_TYPE;
882 			if (skb->protocol == htons(ETH_P_IP))
883 				wc->network_hdr_type = RDMA_NETWORK_IPV4;
884 			else
885 				wc->network_hdr_type = RDMA_NETWORK_IPV6;
886 
887 			if (is_vlan_dev(skb->dev)) {
888 				wc->wc_flags |= IB_WC_WITH_VLAN;
889 				wc->vlan_id = vlan_dev_vlan_id(skb->dev);
890 			}
891 
892 			if (pkt->mask & RXE_IMMDT_MASK) {
893 				wc->wc_flags |= IB_WC_WITH_IMM;
894 				wc->ex.imm_data = immdt_imm(pkt);
895 			}
896 
897 			if (pkt->mask & RXE_IETH_MASK) {
898 				struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
899 				struct rxe_mem *rmr;
900 
901 				wc->wc_flags |= IB_WC_WITH_INVALIDATE;
902 				wc->ex.invalidate_rkey = ieth_rkey(pkt);
903 
904 				rmr = rxe_pool_get_index(&rxe->mr_pool,
905 							 wc->ex.invalidate_rkey >> 8);
906 				if (unlikely(!rmr)) {
907 					pr_err("Bad rkey %#x invalidation\n",
908 					       wc->ex.invalidate_rkey);
909 					return RESPST_ERROR;
910 				}
911 				rmr->state = RXE_MEM_STATE_FREE;
912 				rxe_drop_ref(rmr);
913 			}
914 
915 			wc->qp			= &qp->ibqp;
916 
917 			if (pkt->mask & RXE_DETH_MASK)
918 				wc->src_qp = deth_sqp(pkt);
919 
920 			wc->port_num		= qp->attr.port_num;
921 		}
922 	}
923 
924 	/* have copy for srq and reference for !srq */
925 	if (!qp->srq)
926 		advance_consumer(qp->rq.queue);
927 
928 	qp->resp.wqe = NULL;
929 
930 	if (rxe_cq_post(qp->rcq, &cqe, pkt ? bth_se(pkt) : 1))
931 		return RESPST_ERR_CQ_OVERFLOW;
932 
933 	if (qp->resp.state == QP_STATE_ERROR)
934 		return RESPST_CHK_RESOURCE;
935 
936 	if (!pkt)
937 		return RESPST_DONE;
938 	else if (qp_type(qp) == IB_QPT_RC)
939 		return RESPST_ACKNOWLEDGE;
940 	else
941 		return RESPST_CLEANUP;
942 }
943 
944 static int send_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
945 		    u8 syndrome, u32 psn)
946 {
947 	int err = 0;
948 	struct rxe_pkt_info ack_pkt;
949 	struct sk_buff *skb;
950 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
951 
952 	skb = prepare_ack_packet(qp, pkt, &ack_pkt, IB_OPCODE_RC_ACKNOWLEDGE,
953 				 0, psn, syndrome, NULL);
954 	if (!skb) {
955 		err = -ENOMEM;
956 		goto err1;
957 	}
958 
959 	err = rxe_xmit_packet(rxe, qp, &ack_pkt, skb);
960 	if (err)
961 		pr_err_ratelimited("Failed sending ack\n");
962 
963 err1:
964 	return err;
965 }
966 
967 static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
968 			   u8 syndrome)
969 {
970 	int rc = 0;
971 	struct rxe_pkt_info ack_pkt;
972 	struct sk_buff *skb;
973 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
974 	struct resp_res *res;
975 
976 	skb = prepare_ack_packet(qp, pkt, &ack_pkt,
977 				 IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE, 0, pkt->psn,
978 				 syndrome, NULL);
979 	if (!skb) {
980 		rc = -ENOMEM;
981 		goto out;
982 	}
983 
984 	rxe_add_ref(qp);
985 
986 	res = &qp->resp.resources[qp->resp.res_head];
987 	free_rd_atomic_resource(qp, res);
988 	rxe_advance_resp_resource(qp);
989 
990 	memcpy(SKB_TO_PKT(skb), &ack_pkt, sizeof(ack_pkt));
991 	memset((unsigned char *)SKB_TO_PKT(skb) + sizeof(ack_pkt), 0,
992 	       sizeof(skb->cb) - sizeof(ack_pkt));
993 
994 	skb_get(skb);
995 	res->type = RXE_ATOMIC_MASK;
996 	res->atomic.skb = skb;
997 	res->first_psn = ack_pkt.psn;
998 	res->last_psn  = ack_pkt.psn;
999 	res->cur_psn   = ack_pkt.psn;
1000 
1001 	rc = rxe_xmit_packet(rxe, qp, &ack_pkt, skb);
1002 	if (rc) {
1003 		pr_err_ratelimited("Failed sending ack\n");
1004 		rxe_drop_ref(qp);
1005 	}
1006 out:
1007 	return rc;
1008 }
1009 
1010 static enum resp_states acknowledge(struct rxe_qp *qp,
1011 				    struct rxe_pkt_info *pkt)
1012 {
1013 	if (qp_type(qp) != IB_QPT_RC)
1014 		return RESPST_CLEANUP;
1015 
1016 	if (qp->resp.aeth_syndrome != AETH_ACK_UNLIMITED)
1017 		send_ack(qp, pkt, qp->resp.aeth_syndrome, pkt->psn);
1018 	else if (pkt->mask & RXE_ATOMIC_MASK)
1019 		send_atomic_ack(qp, pkt, AETH_ACK_UNLIMITED);
1020 	else if (bth_ack(pkt))
1021 		send_ack(qp, pkt, AETH_ACK_UNLIMITED, pkt->psn);
1022 
1023 	return RESPST_CLEANUP;
1024 }
1025 
1026 static enum resp_states cleanup(struct rxe_qp *qp,
1027 				struct rxe_pkt_info *pkt)
1028 {
1029 	struct sk_buff *skb;
1030 
1031 	if (pkt) {
1032 		skb = skb_dequeue(&qp->req_pkts);
1033 		rxe_drop_ref(qp);
1034 		kfree_skb(skb);
1035 	}
1036 
1037 	if (qp->resp.mr) {
1038 		rxe_drop_ref(qp->resp.mr);
1039 		qp->resp.mr = NULL;
1040 	}
1041 
1042 	return RESPST_DONE;
1043 }
1044 
1045 static struct resp_res *find_resource(struct rxe_qp *qp, u32 psn)
1046 {
1047 	int i;
1048 
1049 	for (i = 0; i < qp->attr.max_dest_rd_atomic; i++) {
1050 		struct resp_res *res = &qp->resp.resources[i];
1051 
1052 		if (res->type == 0)
1053 			continue;
1054 
1055 		if (psn_compare(psn, res->first_psn) >= 0 &&
1056 		    psn_compare(psn, res->last_psn) <= 0) {
1057 			return res;
1058 		}
1059 	}
1060 
1061 	return NULL;
1062 }
1063 
1064 static enum resp_states duplicate_request(struct rxe_qp *qp,
1065 					  struct rxe_pkt_info *pkt)
1066 {
1067 	enum resp_states rc;
1068 	u32 prev_psn = (qp->resp.psn - 1) & BTH_PSN_MASK;
1069 
1070 	if (pkt->mask & RXE_SEND_MASK ||
1071 	    pkt->mask & RXE_WRITE_MASK) {
1072 		/* SEND. Ack again and cleanup. C9-105. */
1073 		if (bth_ack(pkt))
1074 			send_ack(qp, pkt, AETH_ACK_UNLIMITED, prev_psn);
1075 		rc = RESPST_CLEANUP;
1076 		goto out;
1077 	} else if (pkt->mask & RXE_READ_MASK) {
1078 		struct resp_res *res;
1079 
1080 		res = find_resource(qp, pkt->psn);
1081 		if (!res) {
1082 			/* Resource not found. Class D error.  Drop the
1083 			 * request.
1084 			 */
1085 			rc = RESPST_CLEANUP;
1086 			goto out;
1087 		} else {
1088 			/* Ensure this new request is the same as the previous
1089 			 * one or a subset of it.
1090 			 */
1091 			u64 iova = reth_va(pkt);
1092 			u32 resid = reth_len(pkt);
1093 
1094 			if (iova < res->read.va_org ||
1095 			    resid > res->read.length ||
1096 			    (iova + resid) > (res->read.va_org +
1097 					      res->read.length)) {
1098 				rc = RESPST_CLEANUP;
1099 				goto out;
1100 			}
1101 
1102 			if (reth_rkey(pkt) != res->read.rkey) {
1103 				rc = RESPST_CLEANUP;
1104 				goto out;
1105 			}
1106 
1107 			res->cur_psn = pkt->psn;
1108 			res->state = (pkt->psn == res->first_psn) ?
1109 					rdatm_res_state_new :
1110 					rdatm_res_state_replay;
1111 
1112 			/* Reset the resource, except length. */
1113 			res->read.va_org = iova;
1114 			res->read.va = iova;
1115 			res->read.resid = resid;
1116 
1117 			/* Replay the RDMA read reply. */
1118 			qp->resp.res = res;
1119 			rc = RESPST_READ_REPLY;
1120 			goto out;
1121 		}
1122 	} else {
1123 		struct resp_res *res;
1124 
1125 		/* Find the operation in our list of responder resources. */
1126 		res = find_resource(qp, pkt->psn);
1127 		if (res) {
1128 			skb_get(res->atomic.skb);
1129 			/* Resend the result. */
1130 			rc = rxe_xmit_packet(to_rdev(qp->ibqp.device), qp,
1131 					     pkt, res->atomic.skb);
1132 			if (rc) {
1133 				pr_err("Failed resending result. This flow is not handled - skb ignored\n");
1134 				rc = RESPST_CLEANUP;
1135 				goto out;
1136 			}
1137 		}
1138 
1139 		/* Resource not found. Class D error. Drop the request. */
1140 		rc = RESPST_CLEANUP;
1141 		goto out;
1142 	}
1143 out:
1144 	return rc;
1145 }
1146 
1147 /* Process a class A or C. Both are treated the same in this implementation. */
1148 static void do_class_ac_error(struct rxe_qp *qp, u8 syndrome,
1149 			      enum ib_wc_status status)
1150 {
1151 	qp->resp.aeth_syndrome	= syndrome;
1152 	qp->resp.status		= status;
1153 
1154 	/* indicate that we should go through the ERROR state */
1155 	qp->resp.goto_error	= 1;
1156 }
1157 
1158 static enum resp_states do_class_d1e_error(struct rxe_qp *qp)
1159 {
1160 	/* UC */
1161 	if (qp->srq) {
1162 		/* Class E */
1163 		qp->resp.drop_msg = 1;
1164 		if (qp->resp.wqe) {
1165 			qp->resp.status = IB_WC_REM_INV_REQ_ERR;
1166 			return RESPST_COMPLETE;
1167 		} else {
1168 			return RESPST_CLEANUP;
1169 		}
1170 	} else {
1171 		/* Class D1. This packet may be the start of a
1172 		 * new message and could be valid. The previous
1173 		 * message is invalid and ignored. reset the
1174 		 * recv wr to its original state
1175 		 */
1176 		if (qp->resp.wqe) {
1177 			qp->resp.wqe->dma.resid = qp->resp.wqe->dma.length;
1178 			qp->resp.wqe->dma.cur_sge = 0;
1179 			qp->resp.wqe->dma.sge_offset = 0;
1180 			qp->resp.opcode = -1;
1181 		}
1182 
1183 		if (qp->resp.mr) {
1184 			rxe_drop_ref(qp->resp.mr);
1185 			qp->resp.mr = NULL;
1186 		}
1187 
1188 		return RESPST_CLEANUP;
1189 	}
1190 }
1191 
1192 static void rxe_drain_req_pkts(struct rxe_qp *qp, bool notify)
1193 {
1194 	struct sk_buff *skb;
1195 
1196 	while ((skb = skb_dequeue(&qp->req_pkts))) {
1197 		rxe_drop_ref(qp);
1198 		kfree_skb(skb);
1199 	}
1200 
1201 	if (notify)
1202 		return;
1203 
1204 	while (!qp->srq && qp->rq.queue && queue_head(qp->rq.queue))
1205 		advance_consumer(qp->rq.queue);
1206 }
1207 
1208 int rxe_responder(void *arg)
1209 {
1210 	struct rxe_qp *qp = (struct rxe_qp *)arg;
1211 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
1212 	enum resp_states state;
1213 	struct rxe_pkt_info *pkt = NULL;
1214 	int ret = 0;
1215 
1216 	rxe_add_ref(qp);
1217 
1218 	qp->resp.aeth_syndrome = AETH_ACK_UNLIMITED;
1219 
1220 	if (!qp->valid) {
1221 		ret = -EINVAL;
1222 		goto done;
1223 	}
1224 
1225 	switch (qp->resp.state) {
1226 	case QP_STATE_RESET:
1227 		state = RESPST_RESET;
1228 		break;
1229 
1230 	default:
1231 		state = RESPST_GET_REQ;
1232 		break;
1233 	}
1234 
1235 	while (1) {
1236 		pr_debug("qp#%d state = %s\n", qp_num(qp),
1237 			 resp_state_name[state]);
1238 		switch (state) {
1239 		case RESPST_GET_REQ:
1240 			state = get_req(qp, &pkt);
1241 			break;
1242 		case RESPST_CHK_PSN:
1243 			state = check_psn(qp, pkt);
1244 			break;
1245 		case RESPST_CHK_OP_SEQ:
1246 			state = check_op_seq(qp, pkt);
1247 			break;
1248 		case RESPST_CHK_OP_VALID:
1249 			state = check_op_valid(qp, pkt);
1250 			break;
1251 		case RESPST_CHK_RESOURCE:
1252 			state = check_resource(qp, pkt);
1253 			break;
1254 		case RESPST_CHK_LENGTH:
1255 			state = check_length(qp, pkt);
1256 			break;
1257 		case RESPST_CHK_RKEY:
1258 			state = check_rkey(qp, pkt);
1259 			break;
1260 		case RESPST_EXECUTE:
1261 			state = execute(qp, pkt);
1262 			break;
1263 		case RESPST_COMPLETE:
1264 			state = do_complete(qp, pkt);
1265 			break;
1266 		case RESPST_READ_REPLY:
1267 			state = read_reply(qp, pkt);
1268 			break;
1269 		case RESPST_ACKNOWLEDGE:
1270 			state = acknowledge(qp, pkt);
1271 			break;
1272 		case RESPST_CLEANUP:
1273 			state = cleanup(qp, pkt);
1274 			break;
1275 		case RESPST_DUPLICATE_REQUEST:
1276 			state = duplicate_request(qp, pkt);
1277 			break;
1278 		case RESPST_ERR_PSN_OUT_OF_SEQ:
1279 			/* RC only - Class B. Drop packet. */
1280 			send_ack(qp, pkt, AETH_NAK_PSN_SEQ_ERROR, qp->resp.psn);
1281 			state = RESPST_CLEANUP;
1282 			break;
1283 
1284 		case RESPST_ERR_TOO_MANY_RDMA_ATM_REQ:
1285 		case RESPST_ERR_MISSING_OPCODE_FIRST:
1286 		case RESPST_ERR_MISSING_OPCODE_LAST_C:
1287 		case RESPST_ERR_UNSUPPORTED_OPCODE:
1288 		case RESPST_ERR_MISALIGNED_ATOMIC:
1289 			/* RC Only - Class C. */
1290 			do_class_ac_error(qp, AETH_NAK_INVALID_REQ,
1291 					  IB_WC_REM_INV_REQ_ERR);
1292 			state = RESPST_COMPLETE;
1293 			break;
1294 
1295 		case RESPST_ERR_MISSING_OPCODE_LAST_D1E:
1296 			state = do_class_d1e_error(qp);
1297 			break;
1298 		case RESPST_ERR_RNR:
1299 			if (qp_type(qp) == IB_QPT_RC) {
1300 				rxe_counter_inc(rxe, RXE_CNT_SND_RNR);
1301 				/* RC - class B */
1302 				send_ack(qp, pkt, AETH_RNR_NAK |
1303 					 (~AETH_TYPE_MASK &
1304 					 qp->attr.min_rnr_timer),
1305 					 pkt->psn);
1306 			} else {
1307 				/* UD/UC - class D */
1308 				qp->resp.drop_msg = 1;
1309 			}
1310 			state = RESPST_CLEANUP;
1311 			break;
1312 
1313 		case RESPST_ERR_RKEY_VIOLATION:
1314 			if (qp_type(qp) == IB_QPT_RC) {
1315 				/* Class C */
1316 				do_class_ac_error(qp, AETH_NAK_REM_ACC_ERR,
1317 						  IB_WC_REM_ACCESS_ERR);
1318 				state = RESPST_COMPLETE;
1319 			} else {
1320 				qp->resp.drop_msg = 1;
1321 				if (qp->srq) {
1322 					/* UC/SRQ Class D */
1323 					qp->resp.status = IB_WC_REM_ACCESS_ERR;
1324 					state = RESPST_COMPLETE;
1325 				} else {
1326 					/* UC/non-SRQ Class E. */
1327 					state = RESPST_CLEANUP;
1328 				}
1329 			}
1330 			break;
1331 
1332 		case RESPST_ERR_LENGTH:
1333 			if (qp_type(qp) == IB_QPT_RC) {
1334 				/* Class C */
1335 				do_class_ac_error(qp, AETH_NAK_INVALID_REQ,
1336 						  IB_WC_REM_INV_REQ_ERR);
1337 				state = RESPST_COMPLETE;
1338 			} else if (qp->srq) {
1339 				/* UC/UD - class E */
1340 				qp->resp.status = IB_WC_REM_INV_REQ_ERR;
1341 				state = RESPST_COMPLETE;
1342 			} else {
1343 				/* UC/UD - class D */
1344 				qp->resp.drop_msg = 1;
1345 				state = RESPST_CLEANUP;
1346 			}
1347 			break;
1348 
1349 		case RESPST_ERR_MALFORMED_WQE:
1350 			/* All, Class A. */
1351 			do_class_ac_error(qp, AETH_NAK_REM_OP_ERR,
1352 					  IB_WC_LOC_QP_OP_ERR);
1353 			state = RESPST_COMPLETE;
1354 			break;
1355 
1356 		case RESPST_ERR_CQ_OVERFLOW:
1357 			/* All - Class G */
1358 			state = RESPST_ERROR;
1359 			break;
1360 
1361 		case RESPST_DONE:
1362 			if (qp->resp.goto_error) {
1363 				state = RESPST_ERROR;
1364 				break;
1365 			}
1366 
1367 			goto done;
1368 
1369 		case RESPST_EXIT:
1370 			if (qp->resp.goto_error) {
1371 				state = RESPST_ERROR;
1372 				break;
1373 			}
1374 
1375 			goto exit;
1376 
1377 		case RESPST_RESET:
1378 			rxe_drain_req_pkts(qp, false);
1379 			qp->resp.wqe = NULL;
1380 			goto exit;
1381 
1382 		case RESPST_ERROR:
1383 			qp->resp.goto_error = 0;
1384 			pr_warn("qp#%d moved to error state\n", qp_num(qp));
1385 			rxe_qp_error(qp);
1386 			goto exit;
1387 
1388 		default:
1389 			WARN_ON_ONCE(1);
1390 		}
1391 	}
1392 
1393 exit:
1394 	ret = -EAGAIN;
1395 done:
1396 	rxe_drop_ref(qp);
1397 	return ret;
1398 }
1399