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_qp *qp, struct sk_buff *skb)
108 {
109 	int must_sched;
110 	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
111 
112 	skb_queue_tail(&qp->req_pkts, skb);
113 
114 	must_sched = (pkt->opcode == IB_OPCODE_RC_RDMA_READ_REQUEST) ||
115 			(skb_queue_len(&qp->req_pkts) > 1);
116 
117 	rxe_run_task(&qp->resp.task, must_sched);
118 }
119 
120 static inline enum resp_states get_req(struct rxe_qp *qp,
121 				       struct rxe_pkt_info **pkt_p)
122 {
123 	struct sk_buff *skb;
124 
125 	if (qp->resp.state == QP_STATE_ERROR) {
126 		while ((skb = skb_dequeue(&qp->req_pkts))) {
127 			rxe_drop_ref(qp);
128 			kfree_skb(skb);
129 		}
130 
131 		/* go drain recv wr queue */
132 		return RESPST_CHK_RESOURCE;
133 	}
134 
135 	skb = skb_peek(&qp->req_pkts);
136 	if (!skb)
137 		return RESPST_EXIT;
138 
139 	*pkt_p = SKB_TO_PKT(skb);
140 
141 	return (qp->resp.res) ? RESPST_READ_REPLY : RESPST_CHK_PSN;
142 }
143 
144 static enum resp_states check_psn(struct rxe_qp *qp,
145 				  struct rxe_pkt_info *pkt)
146 {
147 	int diff = psn_compare(pkt->psn, qp->resp.psn);
148 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
149 
150 	switch (qp_type(qp)) {
151 	case IB_QPT_RC:
152 		if (diff > 0) {
153 			if (qp->resp.sent_psn_nak)
154 				return RESPST_CLEANUP;
155 
156 			qp->resp.sent_psn_nak = 1;
157 			rxe_counter_inc(rxe, RXE_CNT_OUT_OF_SEQ_REQ);
158 			return RESPST_ERR_PSN_OUT_OF_SEQ;
159 
160 		} else if (diff < 0) {
161 			rxe_counter_inc(rxe, RXE_CNT_DUP_REQ);
162 			return RESPST_DUPLICATE_REQUEST;
163 		}
164 
165 		if (qp->resp.sent_psn_nak)
166 			qp->resp.sent_psn_nak = 0;
167 
168 		break;
169 
170 	case IB_QPT_UC:
171 		if (qp->resp.drop_msg || diff != 0) {
172 			if (pkt->mask & RXE_START_MASK) {
173 				qp->resp.drop_msg = 0;
174 				return RESPST_CHK_OP_SEQ;
175 			}
176 
177 			qp->resp.drop_msg = 1;
178 			return RESPST_CLEANUP;
179 		}
180 		break;
181 	default:
182 		break;
183 	}
184 
185 	return RESPST_CHK_OP_SEQ;
186 }
187 
188 static enum resp_states check_op_seq(struct rxe_qp *qp,
189 				     struct rxe_pkt_info *pkt)
190 {
191 	switch (qp_type(qp)) {
192 	case IB_QPT_RC:
193 		switch (qp->resp.opcode) {
194 		case IB_OPCODE_RC_SEND_FIRST:
195 		case IB_OPCODE_RC_SEND_MIDDLE:
196 			switch (pkt->opcode) {
197 			case IB_OPCODE_RC_SEND_MIDDLE:
198 			case IB_OPCODE_RC_SEND_LAST:
199 			case IB_OPCODE_RC_SEND_LAST_WITH_IMMEDIATE:
200 			case IB_OPCODE_RC_SEND_LAST_WITH_INVALIDATE:
201 				return RESPST_CHK_OP_VALID;
202 			default:
203 				return RESPST_ERR_MISSING_OPCODE_LAST_C;
204 			}
205 
206 		case IB_OPCODE_RC_RDMA_WRITE_FIRST:
207 		case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
208 			switch (pkt->opcode) {
209 			case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
210 			case IB_OPCODE_RC_RDMA_WRITE_LAST:
211 			case IB_OPCODE_RC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
212 				return RESPST_CHK_OP_VALID;
213 			default:
214 				return RESPST_ERR_MISSING_OPCODE_LAST_C;
215 			}
216 
217 		default:
218 			switch (pkt->opcode) {
219 			case IB_OPCODE_RC_SEND_MIDDLE:
220 			case IB_OPCODE_RC_SEND_LAST:
221 			case IB_OPCODE_RC_SEND_LAST_WITH_IMMEDIATE:
222 			case IB_OPCODE_RC_SEND_LAST_WITH_INVALIDATE:
223 			case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
224 			case IB_OPCODE_RC_RDMA_WRITE_LAST:
225 			case IB_OPCODE_RC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
226 				return RESPST_ERR_MISSING_OPCODE_FIRST;
227 			default:
228 				return RESPST_CHK_OP_VALID;
229 			}
230 		}
231 		break;
232 
233 	case IB_QPT_UC:
234 		switch (qp->resp.opcode) {
235 		case IB_OPCODE_UC_SEND_FIRST:
236 		case IB_OPCODE_UC_SEND_MIDDLE:
237 			switch (pkt->opcode) {
238 			case IB_OPCODE_UC_SEND_MIDDLE:
239 			case IB_OPCODE_UC_SEND_LAST:
240 			case IB_OPCODE_UC_SEND_LAST_WITH_IMMEDIATE:
241 				return RESPST_CHK_OP_VALID;
242 			default:
243 				return RESPST_ERR_MISSING_OPCODE_LAST_D1E;
244 			}
245 
246 		case IB_OPCODE_UC_RDMA_WRITE_FIRST:
247 		case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
248 			switch (pkt->opcode) {
249 			case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
250 			case IB_OPCODE_UC_RDMA_WRITE_LAST:
251 			case IB_OPCODE_UC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
252 				return RESPST_CHK_OP_VALID;
253 			default:
254 				return RESPST_ERR_MISSING_OPCODE_LAST_D1E;
255 			}
256 
257 		default:
258 			switch (pkt->opcode) {
259 			case IB_OPCODE_UC_SEND_MIDDLE:
260 			case IB_OPCODE_UC_SEND_LAST:
261 			case IB_OPCODE_UC_SEND_LAST_WITH_IMMEDIATE:
262 			case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
263 			case IB_OPCODE_UC_RDMA_WRITE_LAST:
264 			case IB_OPCODE_UC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
265 				qp->resp.drop_msg = 1;
266 				return RESPST_CLEANUP;
267 			default:
268 				return RESPST_CHK_OP_VALID;
269 			}
270 		}
271 		break;
272 
273 	default:
274 		return RESPST_CHK_OP_VALID;
275 	}
276 }
277 
278 static enum resp_states check_op_valid(struct rxe_qp *qp,
279 				       struct rxe_pkt_info *pkt)
280 {
281 	switch (qp_type(qp)) {
282 	case IB_QPT_RC:
283 		if (((pkt->mask & RXE_READ_MASK) &&
284 		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_READ)) ||
285 		    ((pkt->mask & RXE_WRITE_MASK) &&
286 		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_WRITE)) ||
287 		    ((pkt->mask & RXE_ATOMIC_MASK) &&
288 		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_ATOMIC))) {
289 			return RESPST_ERR_UNSUPPORTED_OPCODE;
290 		}
291 
292 		break;
293 
294 	case IB_QPT_UC:
295 		if ((pkt->mask & RXE_WRITE_MASK) &&
296 		    !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_WRITE)) {
297 			qp->resp.drop_msg = 1;
298 			return RESPST_CLEANUP;
299 		}
300 
301 		break;
302 
303 	case IB_QPT_UD:
304 	case IB_QPT_SMI:
305 	case IB_QPT_GSI:
306 		break;
307 
308 	default:
309 		WARN_ON_ONCE(1);
310 		break;
311 	}
312 
313 	return RESPST_CHK_RESOURCE;
314 }
315 
316 static enum resp_states get_srq_wqe(struct rxe_qp *qp)
317 {
318 	struct rxe_srq *srq = qp->srq;
319 	struct rxe_queue *q = srq->rq.queue;
320 	struct rxe_recv_wqe *wqe;
321 	struct ib_event ev;
322 
323 	if (srq->error)
324 		return RESPST_ERR_RNR;
325 
326 	spin_lock_bh(&srq->rq.consumer_lock);
327 
328 	wqe = queue_head(q);
329 	if (!wqe) {
330 		spin_unlock_bh(&srq->rq.consumer_lock);
331 		return RESPST_ERR_RNR;
332 	}
333 
334 	/* note kernel and user space recv wqes have same size */
335 	memcpy(&qp->resp.srq_wqe, wqe, sizeof(qp->resp.srq_wqe));
336 
337 	qp->resp.wqe = &qp->resp.srq_wqe.wqe;
338 	advance_consumer(q);
339 
340 	if (srq->limit && srq->ibsrq.event_handler &&
341 	    (queue_count(q) < srq->limit)) {
342 		srq->limit = 0;
343 		goto event;
344 	}
345 
346 	spin_unlock_bh(&srq->rq.consumer_lock);
347 	return RESPST_CHK_LENGTH;
348 
349 event:
350 	spin_unlock_bh(&srq->rq.consumer_lock);
351 	ev.device = qp->ibqp.device;
352 	ev.element.srq = qp->ibqp.srq;
353 	ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
354 	srq->ibsrq.event_handler(&ev, srq->ibsrq.srq_context);
355 	return RESPST_CHK_LENGTH;
356 }
357 
358 static enum resp_states check_resource(struct rxe_qp *qp,
359 				       struct rxe_pkt_info *pkt)
360 {
361 	struct rxe_srq *srq = qp->srq;
362 
363 	if (qp->resp.state == QP_STATE_ERROR) {
364 		if (qp->resp.wqe) {
365 			qp->resp.status = IB_WC_WR_FLUSH_ERR;
366 			return RESPST_COMPLETE;
367 		} else if (!srq) {
368 			qp->resp.wqe = queue_head(qp->rq.queue);
369 			if (qp->resp.wqe) {
370 				qp->resp.status = IB_WC_WR_FLUSH_ERR;
371 				return RESPST_COMPLETE;
372 			} else {
373 				return RESPST_EXIT;
374 			}
375 		} else {
376 			return RESPST_EXIT;
377 		}
378 	}
379 
380 	if (pkt->mask & RXE_READ_OR_ATOMIC) {
381 		/* it is the requesters job to not send
382 		 * too many read/atomic ops, we just
383 		 * recycle the responder resource queue
384 		 */
385 		if (likely(qp->attr.max_dest_rd_atomic > 0))
386 			return RESPST_CHK_LENGTH;
387 		else
388 			return RESPST_ERR_TOO_MANY_RDMA_ATM_REQ;
389 	}
390 
391 	if (pkt->mask & RXE_RWR_MASK) {
392 		if (srq)
393 			return get_srq_wqe(qp);
394 
395 		qp->resp.wqe = queue_head(qp->rq.queue);
396 		return (qp->resp.wqe) ? RESPST_CHK_LENGTH : RESPST_ERR_RNR;
397 	}
398 
399 	return RESPST_CHK_LENGTH;
400 }
401 
402 static enum resp_states check_length(struct rxe_qp *qp,
403 				     struct rxe_pkt_info *pkt)
404 {
405 	switch (qp_type(qp)) {
406 	case IB_QPT_RC:
407 		return RESPST_CHK_RKEY;
408 
409 	case IB_QPT_UC:
410 		return RESPST_CHK_RKEY;
411 
412 	default:
413 		return RESPST_CHK_RKEY;
414 	}
415 }
416 
417 static enum resp_states check_rkey(struct rxe_qp *qp,
418 				   struct rxe_pkt_info *pkt)
419 {
420 	struct rxe_mem *mem = NULL;
421 	u64 va;
422 	u32 rkey;
423 	u32 resid;
424 	u32 pktlen;
425 	int mtu = qp->mtu;
426 	enum resp_states state;
427 	int access;
428 
429 	if (pkt->mask & (RXE_READ_MASK | RXE_WRITE_MASK)) {
430 		if (pkt->mask & RXE_RETH_MASK) {
431 			qp->resp.va = reth_va(pkt);
432 			qp->resp.rkey = reth_rkey(pkt);
433 			qp->resp.resid = reth_len(pkt);
434 			qp->resp.length = reth_len(pkt);
435 		}
436 		access = (pkt->mask & RXE_READ_MASK) ? IB_ACCESS_REMOTE_READ
437 						     : IB_ACCESS_REMOTE_WRITE;
438 	} else if (pkt->mask & RXE_ATOMIC_MASK) {
439 		qp->resp.va = atmeth_va(pkt);
440 		qp->resp.rkey = atmeth_rkey(pkt);
441 		qp->resp.resid = sizeof(u64);
442 		access = IB_ACCESS_REMOTE_ATOMIC;
443 	} else {
444 		return RESPST_EXECUTE;
445 	}
446 
447 	/* A zero-byte op is not required to set an addr or rkey. */
448 	if ((pkt->mask & (RXE_READ_MASK | RXE_WRITE_OR_SEND)) &&
449 	    (pkt->mask & RXE_RETH_MASK) &&
450 	    reth_len(pkt) == 0) {
451 		return RESPST_EXECUTE;
452 	}
453 
454 	va	= qp->resp.va;
455 	rkey	= qp->resp.rkey;
456 	resid	= qp->resp.resid;
457 	pktlen	= payload_size(pkt);
458 
459 	mem = lookup_mem(qp->pd, access, rkey, lookup_remote);
460 	if (!mem) {
461 		state = RESPST_ERR_RKEY_VIOLATION;
462 		goto err;
463 	}
464 
465 	if (unlikely(mem->state == RXE_MEM_STATE_FREE)) {
466 		state = RESPST_ERR_RKEY_VIOLATION;
467 		goto err;
468 	}
469 
470 	if (mem_check_range(mem, va, resid)) {
471 		state = RESPST_ERR_RKEY_VIOLATION;
472 		goto err;
473 	}
474 
475 	if (pkt->mask & RXE_WRITE_MASK)	 {
476 		if (resid > mtu) {
477 			if (pktlen != mtu || bth_pad(pkt)) {
478 				state = RESPST_ERR_LENGTH;
479 				goto err;
480 			}
481 		} else {
482 			if (pktlen != resid) {
483 				state = RESPST_ERR_LENGTH;
484 				goto err;
485 			}
486 			if ((bth_pad(pkt) != (0x3 & (-resid)))) {
487 				/* This case may not be exactly that
488 				 * but nothing else fits.
489 				 */
490 				state = RESPST_ERR_LENGTH;
491 				goto err;
492 			}
493 		}
494 	}
495 
496 	WARN_ON_ONCE(qp->resp.mr);
497 
498 	qp->resp.mr = mem;
499 	return RESPST_EXECUTE;
500 
501 err:
502 	if (mem)
503 		rxe_drop_ref(mem);
504 	return state;
505 }
506 
507 static enum resp_states send_data_in(struct rxe_qp *qp, void *data_addr,
508 				     int data_len)
509 {
510 	int err;
511 
512 	err = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE, &qp->resp.wqe->dma,
513 			data_addr, data_len, to_mem_obj, NULL);
514 	if (unlikely(err))
515 		return (err == -ENOSPC) ? RESPST_ERR_LENGTH
516 					: RESPST_ERR_MALFORMED_WQE;
517 
518 	return RESPST_NONE;
519 }
520 
521 static enum resp_states write_data_in(struct rxe_qp *qp,
522 				      struct rxe_pkt_info *pkt)
523 {
524 	enum resp_states rc = RESPST_NONE;
525 	int	err;
526 	int data_len = payload_size(pkt);
527 
528 	err = rxe_mem_copy(qp->resp.mr, qp->resp.va, payload_addr(pkt),
529 			   data_len, to_mem_obj, NULL);
530 	if (err) {
531 		rc = RESPST_ERR_RKEY_VIOLATION;
532 		goto out;
533 	}
534 
535 	qp->resp.va += data_len;
536 	qp->resp.resid -= data_len;
537 
538 out:
539 	return rc;
540 }
541 
542 /* Guarantee atomicity of atomic operations at the machine level. */
543 static DEFINE_SPINLOCK(atomic_ops_lock);
544 
545 static enum resp_states process_atomic(struct rxe_qp *qp,
546 				       struct rxe_pkt_info *pkt)
547 {
548 	u64 iova = atmeth_va(pkt);
549 	u64 *vaddr;
550 	enum resp_states ret;
551 	struct rxe_mem *mr = qp->resp.mr;
552 
553 	if (mr->state != RXE_MEM_STATE_VALID) {
554 		ret = RESPST_ERR_RKEY_VIOLATION;
555 		goto out;
556 	}
557 
558 	vaddr = iova_to_vaddr(mr, iova, sizeof(u64));
559 
560 	/* check vaddr is 8 bytes aligned. */
561 	if (!vaddr || (uintptr_t)vaddr & 7) {
562 		ret = RESPST_ERR_MISALIGNED_ATOMIC;
563 		goto out;
564 	}
565 
566 	spin_lock_bh(&atomic_ops_lock);
567 
568 	qp->resp.atomic_orig = *vaddr;
569 
570 	if (pkt->opcode == IB_OPCODE_RC_COMPARE_SWAP ||
571 	    pkt->opcode == IB_OPCODE_RD_COMPARE_SWAP) {
572 		if (*vaddr == atmeth_comp(pkt))
573 			*vaddr = atmeth_swap_add(pkt);
574 	} else {
575 		*vaddr += atmeth_swap_add(pkt);
576 	}
577 
578 	spin_unlock_bh(&atomic_ops_lock);
579 
580 	ret = RESPST_NONE;
581 out:
582 	return ret;
583 }
584 
585 static struct sk_buff *prepare_ack_packet(struct rxe_qp *qp,
586 					  struct rxe_pkt_info *pkt,
587 					  struct rxe_pkt_info *ack,
588 					  int opcode,
589 					  int payload,
590 					  u32 psn,
591 					  u8 syndrome,
592 					  u32 *crcp)
593 {
594 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
595 	struct sk_buff *skb;
596 	u32 crc = 0;
597 	u32 *p;
598 	int paylen;
599 	int pad;
600 	int err;
601 
602 	/*
603 	 * allocate packet
604 	 */
605 	pad = (-payload) & 0x3;
606 	paylen = rxe_opcode[opcode].length + payload + pad + RXE_ICRC_SIZE;
607 
608 	skb = rxe_init_packet(rxe, &qp->pri_av, paylen, ack);
609 	if (!skb)
610 		return NULL;
611 
612 	ack->qp = qp;
613 	ack->opcode = opcode;
614 	ack->mask = rxe_opcode[opcode].mask;
615 	ack->offset = pkt->offset;
616 	ack->paylen = paylen;
617 
618 	/* fill in bth using the request packet headers */
619 	memcpy(ack->hdr, pkt->hdr, pkt->offset + RXE_BTH_BYTES);
620 
621 	bth_set_opcode(ack, opcode);
622 	bth_set_qpn(ack, qp->attr.dest_qp_num);
623 	bth_set_pad(ack, pad);
624 	bth_set_se(ack, 0);
625 	bth_set_psn(ack, psn);
626 	bth_set_ack(ack, 0);
627 	ack->psn = psn;
628 
629 	if (ack->mask & RXE_AETH_MASK) {
630 		aeth_set_syn(ack, syndrome);
631 		aeth_set_msn(ack, qp->resp.msn);
632 	}
633 
634 	if (ack->mask & RXE_ATMACK_MASK)
635 		atmack_set_orig(ack, qp->resp.atomic_orig);
636 
637 	err = rxe_prepare(ack, skb, &crc);
638 	if (err) {
639 		kfree_skb(skb);
640 		return NULL;
641 	}
642 
643 	if (crcp) {
644 		/* CRC computation will be continued by the caller */
645 		*crcp = crc;
646 	} else {
647 		p = payload_addr(ack) + payload + bth_pad(ack);
648 		*p = ~crc;
649 	}
650 
651 	return skb;
652 }
653 
654 /* RDMA read response. If res is not NULL, then we have a current RDMA request
655  * being processed or replayed.
656  */
657 static enum resp_states read_reply(struct rxe_qp *qp,
658 				   struct rxe_pkt_info *req_pkt)
659 {
660 	struct rxe_pkt_info ack_pkt;
661 	struct sk_buff *skb;
662 	int mtu = qp->mtu;
663 	enum resp_states state;
664 	int payload;
665 	int opcode;
666 	int err;
667 	struct resp_res *res = qp->resp.res;
668 	u32 icrc;
669 	u32 *p;
670 
671 	if (!res) {
672 		/* This is the first time we process that request. Get a
673 		 * resource
674 		 */
675 		res = &qp->resp.resources[qp->resp.res_head];
676 
677 		free_rd_atomic_resource(qp, res);
678 		rxe_advance_resp_resource(qp);
679 
680 		res->type		= RXE_READ_MASK;
681 		res->replay		= 0;
682 
683 		res->read.va		= qp->resp.va;
684 		res->read.va_org	= qp->resp.va;
685 
686 		res->first_psn		= req_pkt->psn;
687 
688 		if (reth_len(req_pkt)) {
689 			res->last_psn	= (req_pkt->psn +
690 					   (reth_len(req_pkt) + mtu - 1) /
691 					   mtu - 1) & BTH_PSN_MASK;
692 		} else {
693 			res->last_psn	= res->first_psn;
694 		}
695 		res->cur_psn		= req_pkt->psn;
696 
697 		res->read.resid		= qp->resp.resid;
698 		res->read.length	= qp->resp.resid;
699 		res->read.rkey		= qp->resp.rkey;
700 
701 		/* note res inherits the reference to mr from qp */
702 		res->read.mr		= qp->resp.mr;
703 		qp->resp.mr		= NULL;
704 
705 		qp->resp.res		= res;
706 		res->state		= rdatm_res_state_new;
707 	}
708 
709 	if (res->state == rdatm_res_state_new) {
710 		if (res->read.resid <= mtu)
711 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY;
712 		else
713 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST;
714 	} else {
715 		if (res->read.resid > mtu)
716 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE;
717 		else
718 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST;
719 	}
720 
721 	res->state = rdatm_res_state_next;
722 
723 	payload = min_t(int, res->read.resid, mtu);
724 
725 	skb = prepare_ack_packet(qp, req_pkt, &ack_pkt, opcode, payload,
726 				 res->cur_psn, AETH_ACK_UNLIMITED, &icrc);
727 	if (!skb)
728 		return RESPST_ERR_RNR;
729 
730 	err = rxe_mem_copy(res->read.mr, res->read.va, payload_addr(&ack_pkt),
731 			   payload, from_mem_obj, &icrc);
732 	if (err)
733 		pr_err("Failed copying memory\n");
734 
735 	p = payload_addr(&ack_pkt) + payload + bth_pad(&ack_pkt);
736 	*p = ~icrc;
737 
738 	err = rxe_xmit_packet(qp, &ack_pkt, skb);
739 	if (err) {
740 		pr_err("Failed sending RDMA reply.\n");
741 		return RESPST_ERR_RNR;
742 	}
743 
744 	res->read.va += payload;
745 	res->read.resid -= payload;
746 	res->cur_psn = (res->cur_psn + 1) & BTH_PSN_MASK;
747 
748 	if (res->read.resid > 0) {
749 		state = RESPST_DONE;
750 	} else {
751 		qp->resp.res = NULL;
752 		if (!res->replay)
753 			qp->resp.opcode = -1;
754 		if (psn_compare(res->cur_psn, qp->resp.psn) >= 0)
755 			qp->resp.psn = res->cur_psn;
756 		state = RESPST_CLEANUP;
757 	}
758 
759 	return state;
760 }
761 
762 static void build_rdma_network_hdr(union rdma_network_hdr *hdr,
763 				   struct rxe_pkt_info *pkt)
764 {
765 	struct sk_buff *skb = PKT_TO_SKB(pkt);
766 
767 	memset(hdr, 0, sizeof(*hdr));
768 	if (skb->protocol == htons(ETH_P_IP))
769 		memcpy(&hdr->roce4grh, ip_hdr(skb), sizeof(hdr->roce4grh));
770 	else if (skb->protocol == htons(ETH_P_IPV6))
771 		memcpy(&hdr->ibgrh, ipv6_hdr(skb), sizeof(hdr->ibgrh));
772 }
773 
774 /* Executes a new request. A retried request never reach that function (send
775  * and writes are discarded, and reads and atomics are retried elsewhere.
776  */
777 static enum resp_states execute(struct rxe_qp *qp, struct rxe_pkt_info *pkt)
778 {
779 	enum resp_states err;
780 
781 	if (pkt->mask & RXE_SEND_MASK) {
782 		if (qp_type(qp) == IB_QPT_UD ||
783 		    qp_type(qp) == IB_QPT_SMI ||
784 		    qp_type(qp) == IB_QPT_GSI) {
785 			union rdma_network_hdr hdr;
786 
787 			build_rdma_network_hdr(&hdr, pkt);
788 
789 			err = send_data_in(qp, &hdr, sizeof(hdr));
790 			if (err)
791 				return err;
792 		}
793 		err = send_data_in(qp, payload_addr(pkt), payload_size(pkt));
794 		if (err)
795 			return err;
796 	} else if (pkt->mask & RXE_WRITE_MASK) {
797 		err = write_data_in(qp, pkt);
798 		if (err)
799 			return err;
800 	} else if (pkt->mask & RXE_READ_MASK) {
801 		/* For RDMA Read we can increment the msn now. See C9-148. */
802 		qp->resp.msn++;
803 		return RESPST_READ_REPLY;
804 	} else if (pkt->mask & RXE_ATOMIC_MASK) {
805 		err = process_atomic(qp, pkt);
806 		if (err)
807 			return err;
808 	} else {
809 		/* Unreachable */
810 		WARN_ON_ONCE(1);
811 	}
812 
813 	/* next expected psn, read handles this separately */
814 	qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
815 	qp->resp.ack_psn = qp->resp.psn;
816 
817 	qp->resp.opcode = pkt->opcode;
818 	qp->resp.status = IB_WC_SUCCESS;
819 
820 	if (pkt->mask & RXE_COMP_MASK) {
821 		/* We successfully processed this new request. */
822 		qp->resp.msn++;
823 		return RESPST_COMPLETE;
824 	} else if (qp_type(qp) == IB_QPT_RC)
825 		return RESPST_ACKNOWLEDGE;
826 	else
827 		return RESPST_CLEANUP;
828 }
829 
830 static enum resp_states do_complete(struct rxe_qp *qp,
831 				    struct rxe_pkt_info *pkt)
832 {
833 	struct rxe_cqe cqe;
834 	struct ib_wc *wc = &cqe.ibwc;
835 	struct ib_uverbs_wc *uwc = &cqe.uibwc;
836 	struct rxe_recv_wqe *wqe = qp->resp.wqe;
837 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
838 
839 	if (unlikely(!wqe))
840 		return RESPST_CLEANUP;
841 
842 	memset(&cqe, 0, sizeof(cqe));
843 
844 	if (qp->rcq->is_user) {
845 		uwc->status             = qp->resp.status;
846 		uwc->qp_num             = qp->ibqp.qp_num;
847 		uwc->wr_id              = wqe->wr_id;
848 	} else {
849 		wc->status              = qp->resp.status;
850 		wc->qp                  = &qp->ibqp;
851 		wc->wr_id               = wqe->wr_id;
852 	}
853 
854 	if (wc->status == IB_WC_SUCCESS) {
855 		rxe_counter_inc(rxe, RXE_CNT_RDMA_RECV);
856 		wc->opcode = (pkt->mask & RXE_IMMDT_MASK &&
857 				pkt->mask & RXE_WRITE_MASK) ?
858 					IB_WC_RECV_RDMA_WITH_IMM : IB_WC_RECV;
859 		wc->vendor_err = 0;
860 		wc->byte_len = (pkt->mask & RXE_IMMDT_MASK &&
861 				pkt->mask & RXE_WRITE_MASK) ?
862 					qp->resp.length : wqe->dma.length - wqe->dma.resid;
863 
864 		/* fields after byte_len are different between kernel and user
865 		 * space
866 		 */
867 		if (qp->rcq->is_user) {
868 			uwc->wc_flags = IB_WC_GRH;
869 
870 			if (pkt->mask & RXE_IMMDT_MASK) {
871 				uwc->wc_flags |= IB_WC_WITH_IMM;
872 				uwc->ex.imm_data = immdt_imm(pkt);
873 			}
874 
875 			if (pkt->mask & RXE_IETH_MASK) {
876 				uwc->wc_flags |= IB_WC_WITH_INVALIDATE;
877 				uwc->ex.invalidate_rkey = ieth_rkey(pkt);
878 			}
879 
880 			uwc->qp_num		= qp->ibqp.qp_num;
881 
882 			if (pkt->mask & RXE_DETH_MASK)
883 				uwc->src_qp = deth_sqp(pkt);
884 
885 			uwc->port_num		= qp->attr.port_num;
886 		} else {
887 			struct sk_buff *skb = PKT_TO_SKB(pkt);
888 
889 			wc->wc_flags = IB_WC_GRH | IB_WC_WITH_NETWORK_HDR_TYPE;
890 			if (skb->protocol == htons(ETH_P_IP))
891 				wc->network_hdr_type = RDMA_NETWORK_IPV4;
892 			else
893 				wc->network_hdr_type = RDMA_NETWORK_IPV6;
894 
895 			if (is_vlan_dev(skb->dev)) {
896 				wc->wc_flags |= IB_WC_WITH_VLAN;
897 				wc->vlan_id = vlan_dev_vlan_id(skb->dev);
898 			}
899 
900 			if (pkt->mask & RXE_IMMDT_MASK) {
901 				wc->wc_flags |= IB_WC_WITH_IMM;
902 				wc->ex.imm_data = immdt_imm(pkt);
903 			}
904 
905 			if (pkt->mask & RXE_IETH_MASK) {
906 				struct rxe_mem *rmr;
907 
908 				wc->wc_flags |= IB_WC_WITH_INVALIDATE;
909 				wc->ex.invalidate_rkey = ieth_rkey(pkt);
910 
911 				rmr = rxe_pool_get_index(&rxe->mr_pool,
912 							 wc->ex.invalidate_rkey >> 8);
913 				if (unlikely(!rmr)) {
914 					pr_err("Bad rkey %#x invalidation\n",
915 					       wc->ex.invalidate_rkey);
916 					return RESPST_ERROR;
917 				}
918 				rmr->state = RXE_MEM_STATE_FREE;
919 				rxe_drop_ref(rmr);
920 			}
921 
922 			wc->qp			= &qp->ibqp;
923 
924 			if (pkt->mask & RXE_DETH_MASK)
925 				wc->src_qp = deth_sqp(pkt);
926 
927 			wc->port_num		= qp->attr.port_num;
928 		}
929 	}
930 
931 	/* have copy for srq and reference for !srq */
932 	if (!qp->srq)
933 		advance_consumer(qp->rq.queue);
934 
935 	qp->resp.wqe = NULL;
936 
937 	if (rxe_cq_post(qp->rcq, &cqe, pkt ? bth_se(pkt) : 1))
938 		return RESPST_ERR_CQ_OVERFLOW;
939 
940 	if (qp->resp.state == QP_STATE_ERROR)
941 		return RESPST_CHK_RESOURCE;
942 
943 	if (!pkt)
944 		return RESPST_DONE;
945 	else if (qp_type(qp) == IB_QPT_RC)
946 		return RESPST_ACKNOWLEDGE;
947 	else
948 		return RESPST_CLEANUP;
949 }
950 
951 static int send_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
952 		    u8 syndrome, u32 psn)
953 {
954 	int err = 0;
955 	struct rxe_pkt_info ack_pkt;
956 	struct sk_buff *skb;
957 
958 	skb = prepare_ack_packet(qp, pkt, &ack_pkt, IB_OPCODE_RC_ACKNOWLEDGE,
959 				 0, psn, syndrome, NULL);
960 	if (!skb) {
961 		err = -ENOMEM;
962 		goto err1;
963 	}
964 
965 	err = rxe_xmit_packet(qp, &ack_pkt, skb);
966 	if (err)
967 		pr_err_ratelimited("Failed sending ack\n");
968 
969 err1:
970 	return err;
971 }
972 
973 static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
974 			   u8 syndrome)
975 {
976 	int rc = 0;
977 	struct rxe_pkt_info ack_pkt;
978 	struct sk_buff *skb;
979 	struct resp_res *res;
980 
981 	skb = prepare_ack_packet(qp, pkt, &ack_pkt,
982 				 IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE, 0, pkt->psn,
983 				 syndrome, NULL);
984 	if (!skb) {
985 		rc = -ENOMEM;
986 		goto out;
987 	}
988 
989 	rxe_add_ref(qp);
990 
991 	res = &qp->resp.resources[qp->resp.res_head];
992 	free_rd_atomic_resource(qp, res);
993 	rxe_advance_resp_resource(qp);
994 
995 	memcpy(SKB_TO_PKT(skb), &ack_pkt, sizeof(ack_pkt));
996 	memset((unsigned char *)SKB_TO_PKT(skb) + sizeof(ack_pkt), 0,
997 	       sizeof(skb->cb) - sizeof(ack_pkt));
998 
999 	skb_get(skb);
1000 	res->type = RXE_ATOMIC_MASK;
1001 	res->atomic.skb = skb;
1002 	res->first_psn = ack_pkt.psn;
1003 	res->last_psn  = ack_pkt.psn;
1004 	res->cur_psn   = ack_pkt.psn;
1005 
1006 	rc = rxe_xmit_packet(qp, &ack_pkt, skb);
1007 	if (rc) {
1008 		pr_err_ratelimited("Failed sending ack\n");
1009 		rxe_drop_ref(qp);
1010 	}
1011 out:
1012 	return rc;
1013 }
1014 
1015 static enum resp_states acknowledge(struct rxe_qp *qp,
1016 				    struct rxe_pkt_info *pkt)
1017 {
1018 	if (qp_type(qp) != IB_QPT_RC)
1019 		return RESPST_CLEANUP;
1020 
1021 	if (qp->resp.aeth_syndrome != AETH_ACK_UNLIMITED)
1022 		send_ack(qp, pkt, qp->resp.aeth_syndrome, pkt->psn);
1023 	else if (pkt->mask & RXE_ATOMIC_MASK)
1024 		send_atomic_ack(qp, pkt, AETH_ACK_UNLIMITED);
1025 	else if (bth_ack(pkt))
1026 		send_ack(qp, pkt, AETH_ACK_UNLIMITED, pkt->psn);
1027 
1028 	return RESPST_CLEANUP;
1029 }
1030 
1031 static enum resp_states cleanup(struct rxe_qp *qp,
1032 				struct rxe_pkt_info *pkt)
1033 {
1034 	struct sk_buff *skb;
1035 
1036 	if (pkt) {
1037 		skb = skb_dequeue(&qp->req_pkts);
1038 		rxe_drop_ref(qp);
1039 		kfree_skb(skb);
1040 	}
1041 
1042 	if (qp->resp.mr) {
1043 		rxe_drop_ref(qp->resp.mr);
1044 		qp->resp.mr = NULL;
1045 	}
1046 
1047 	return RESPST_DONE;
1048 }
1049 
1050 static struct resp_res *find_resource(struct rxe_qp *qp, u32 psn)
1051 {
1052 	int i;
1053 
1054 	for (i = 0; i < qp->attr.max_dest_rd_atomic; i++) {
1055 		struct resp_res *res = &qp->resp.resources[i];
1056 
1057 		if (res->type == 0)
1058 			continue;
1059 
1060 		if (psn_compare(psn, res->first_psn) >= 0 &&
1061 		    psn_compare(psn, res->last_psn) <= 0) {
1062 			return res;
1063 		}
1064 	}
1065 
1066 	return NULL;
1067 }
1068 
1069 static enum resp_states duplicate_request(struct rxe_qp *qp,
1070 					  struct rxe_pkt_info *pkt)
1071 {
1072 	enum resp_states rc;
1073 	u32 prev_psn = (qp->resp.ack_psn - 1) & BTH_PSN_MASK;
1074 
1075 	if (pkt->mask & RXE_SEND_MASK ||
1076 	    pkt->mask & RXE_WRITE_MASK) {
1077 		/* SEND. Ack again and cleanup. C9-105. */
1078 		if (bth_ack(pkt))
1079 			send_ack(qp, pkt, AETH_ACK_UNLIMITED, prev_psn);
1080 		rc = RESPST_CLEANUP;
1081 		goto out;
1082 	} else if (pkt->mask & RXE_READ_MASK) {
1083 		struct resp_res *res;
1084 
1085 		res = find_resource(qp, pkt->psn);
1086 		if (!res) {
1087 			/* Resource not found. Class D error.  Drop the
1088 			 * request.
1089 			 */
1090 			rc = RESPST_CLEANUP;
1091 			goto out;
1092 		} else {
1093 			/* Ensure this new request is the same as the previous
1094 			 * one or a subset of it.
1095 			 */
1096 			u64 iova = reth_va(pkt);
1097 			u32 resid = reth_len(pkt);
1098 
1099 			if (iova < res->read.va_org ||
1100 			    resid > res->read.length ||
1101 			    (iova + resid) > (res->read.va_org +
1102 					      res->read.length)) {
1103 				rc = RESPST_CLEANUP;
1104 				goto out;
1105 			}
1106 
1107 			if (reth_rkey(pkt) != res->read.rkey) {
1108 				rc = RESPST_CLEANUP;
1109 				goto out;
1110 			}
1111 
1112 			res->cur_psn = pkt->psn;
1113 			res->state = (pkt->psn == res->first_psn) ?
1114 					rdatm_res_state_new :
1115 					rdatm_res_state_replay;
1116 			res->replay = 1;
1117 
1118 			/* Reset the resource, except length. */
1119 			res->read.va_org = iova;
1120 			res->read.va = iova;
1121 			res->read.resid = resid;
1122 
1123 			/* Replay the RDMA read reply. */
1124 			qp->resp.res = res;
1125 			rc = RESPST_READ_REPLY;
1126 			goto out;
1127 		}
1128 	} else {
1129 		struct resp_res *res;
1130 
1131 		/* Find the operation in our list of responder resources. */
1132 		res = find_resource(qp, pkt->psn);
1133 		if (res) {
1134 			skb_get(res->atomic.skb);
1135 			/* Resend the result. */
1136 			rc = rxe_xmit_packet(qp, pkt, res->atomic.skb);
1137 			if (rc) {
1138 				pr_err("Failed resending result. This flow is not handled - skb ignored\n");
1139 				rc = RESPST_CLEANUP;
1140 				goto out;
1141 			}
1142 		}
1143 
1144 		/* Resource not found. Class D error. Drop the request. */
1145 		rc = RESPST_CLEANUP;
1146 		goto out;
1147 	}
1148 out:
1149 	return rc;
1150 }
1151 
1152 /* Process a class A or C. Both are treated the same in this implementation. */
1153 static void do_class_ac_error(struct rxe_qp *qp, u8 syndrome,
1154 			      enum ib_wc_status status)
1155 {
1156 	qp->resp.aeth_syndrome	= syndrome;
1157 	qp->resp.status		= status;
1158 
1159 	/* indicate that we should go through the ERROR state */
1160 	qp->resp.goto_error	= 1;
1161 }
1162 
1163 static enum resp_states do_class_d1e_error(struct rxe_qp *qp)
1164 {
1165 	/* UC */
1166 	if (qp->srq) {
1167 		/* Class E */
1168 		qp->resp.drop_msg = 1;
1169 		if (qp->resp.wqe) {
1170 			qp->resp.status = IB_WC_REM_INV_REQ_ERR;
1171 			return RESPST_COMPLETE;
1172 		} else {
1173 			return RESPST_CLEANUP;
1174 		}
1175 	} else {
1176 		/* Class D1. This packet may be the start of a
1177 		 * new message and could be valid. The previous
1178 		 * message is invalid and ignored. reset the
1179 		 * recv wr to its original state
1180 		 */
1181 		if (qp->resp.wqe) {
1182 			qp->resp.wqe->dma.resid = qp->resp.wqe->dma.length;
1183 			qp->resp.wqe->dma.cur_sge = 0;
1184 			qp->resp.wqe->dma.sge_offset = 0;
1185 			qp->resp.opcode = -1;
1186 		}
1187 
1188 		if (qp->resp.mr) {
1189 			rxe_drop_ref(qp->resp.mr);
1190 			qp->resp.mr = NULL;
1191 		}
1192 
1193 		return RESPST_CLEANUP;
1194 	}
1195 }
1196 
1197 static void rxe_drain_req_pkts(struct rxe_qp *qp, bool notify)
1198 {
1199 	struct sk_buff *skb;
1200 
1201 	while ((skb = skb_dequeue(&qp->req_pkts))) {
1202 		rxe_drop_ref(qp);
1203 		kfree_skb(skb);
1204 	}
1205 
1206 	if (notify)
1207 		return;
1208 
1209 	while (!qp->srq && qp->rq.queue && queue_head(qp->rq.queue))
1210 		advance_consumer(qp->rq.queue);
1211 }
1212 
1213 int rxe_responder(void *arg)
1214 {
1215 	struct rxe_qp *qp = (struct rxe_qp *)arg;
1216 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
1217 	enum resp_states state;
1218 	struct rxe_pkt_info *pkt = NULL;
1219 	int ret = 0;
1220 
1221 	rxe_add_ref(qp);
1222 
1223 	qp->resp.aeth_syndrome = AETH_ACK_UNLIMITED;
1224 
1225 	if (!qp->valid) {
1226 		ret = -EINVAL;
1227 		goto done;
1228 	}
1229 
1230 	switch (qp->resp.state) {
1231 	case QP_STATE_RESET:
1232 		state = RESPST_RESET;
1233 		break;
1234 
1235 	default:
1236 		state = RESPST_GET_REQ;
1237 		break;
1238 	}
1239 
1240 	while (1) {
1241 		pr_debug("qp#%d state = %s\n", qp_num(qp),
1242 			 resp_state_name[state]);
1243 		switch (state) {
1244 		case RESPST_GET_REQ:
1245 			state = get_req(qp, &pkt);
1246 			break;
1247 		case RESPST_CHK_PSN:
1248 			state = check_psn(qp, pkt);
1249 			break;
1250 		case RESPST_CHK_OP_SEQ:
1251 			state = check_op_seq(qp, pkt);
1252 			break;
1253 		case RESPST_CHK_OP_VALID:
1254 			state = check_op_valid(qp, pkt);
1255 			break;
1256 		case RESPST_CHK_RESOURCE:
1257 			state = check_resource(qp, pkt);
1258 			break;
1259 		case RESPST_CHK_LENGTH:
1260 			state = check_length(qp, pkt);
1261 			break;
1262 		case RESPST_CHK_RKEY:
1263 			state = check_rkey(qp, pkt);
1264 			break;
1265 		case RESPST_EXECUTE:
1266 			state = execute(qp, pkt);
1267 			break;
1268 		case RESPST_COMPLETE:
1269 			state = do_complete(qp, pkt);
1270 			break;
1271 		case RESPST_READ_REPLY:
1272 			state = read_reply(qp, pkt);
1273 			break;
1274 		case RESPST_ACKNOWLEDGE:
1275 			state = acknowledge(qp, pkt);
1276 			break;
1277 		case RESPST_CLEANUP:
1278 			state = cleanup(qp, pkt);
1279 			break;
1280 		case RESPST_DUPLICATE_REQUEST:
1281 			state = duplicate_request(qp, pkt);
1282 			break;
1283 		case RESPST_ERR_PSN_OUT_OF_SEQ:
1284 			/* RC only - Class B. Drop packet. */
1285 			send_ack(qp, pkt, AETH_NAK_PSN_SEQ_ERROR, qp->resp.psn);
1286 			state = RESPST_CLEANUP;
1287 			break;
1288 
1289 		case RESPST_ERR_TOO_MANY_RDMA_ATM_REQ:
1290 		case RESPST_ERR_MISSING_OPCODE_FIRST:
1291 		case RESPST_ERR_MISSING_OPCODE_LAST_C:
1292 		case RESPST_ERR_UNSUPPORTED_OPCODE:
1293 		case RESPST_ERR_MISALIGNED_ATOMIC:
1294 			/* RC Only - Class C. */
1295 			do_class_ac_error(qp, AETH_NAK_INVALID_REQ,
1296 					  IB_WC_REM_INV_REQ_ERR);
1297 			state = RESPST_COMPLETE;
1298 			break;
1299 
1300 		case RESPST_ERR_MISSING_OPCODE_LAST_D1E:
1301 			state = do_class_d1e_error(qp);
1302 			break;
1303 		case RESPST_ERR_RNR:
1304 			if (qp_type(qp) == IB_QPT_RC) {
1305 				rxe_counter_inc(rxe, RXE_CNT_SND_RNR);
1306 				/* RC - class B */
1307 				send_ack(qp, pkt, AETH_RNR_NAK |
1308 					 (~AETH_TYPE_MASK &
1309 					 qp->attr.min_rnr_timer),
1310 					 pkt->psn);
1311 			} else {
1312 				/* UD/UC - class D */
1313 				qp->resp.drop_msg = 1;
1314 			}
1315 			state = RESPST_CLEANUP;
1316 			break;
1317 
1318 		case RESPST_ERR_RKEY_VIOLATION:
1319 			if (qp_type(qp) == IB_QPT_RC) {
1320 				/* Class C */
1321 				do_class_ac_error(qp, AETH_NAK_REM_ACC_ERR,
1322 						  IB_WC_REM_ACCESS_ERR);
1323 				state = RESPST_COMPLETE;
1324 			} else {
1325 				qp->resp.drop_msg = 1;
1326 				if (qp->srq) {
1327 					/* UC/SRQ Class D */
1328 					qp->resp.status = IB_WC_REM_ACCESS_ERR;
1329 					state = RESPST_COMPLETE;
1330 				} else {
1331 					/* UC/non-SRQ Class E. */
1332 					state = RESPST_CLEANUP;
1333 				}
1334 			}
1335 			break;
1336 
1337 		case RESPST_ERR_LENGTH:
1338 			if (qp_type(qp) == IB_QPT_RC) {
1339 				/* Class C */
1340 				do_class_ac_error(qp, AETH_NAK_INVALID_REQ,
1341 						  IB_WC_REM_INV_REQ_ERR);
1342 				state = RESPST_COMPLETE;
1343 			} else if (qp->srq) {
1344 				/* UC/UD - class E */
1345 				qp->resp.status = IB_WC_REM_INV_REQ_ERR;
1346 				state = RESPST_COMPLETE;
1347 			} else {
1348 				/* UC/UD - class D */
1349 				qp->resp.drop_msg = 1;
1350 				state = RESPST_CLEANUP;
1351 			}
1352 			break;
1353 
1354 		case RESPST_ERR_MALFORMED_WQE:
1355 			/* All, Class A. */
1356 			do_class_ac_error(qp, AETH_NAK_REM_OP_ERR,
1357 					  IB_WC_LOC_QP_OP_ERR);
1358 			state = RESPST_COMPLETE;
1359 			break;
1360 
1361 		case RESPST_ERR_CQ_OVERFLOW:
1362 			/* All - Class G */
1363 			state = RESPST_ERROR;
1364 			break;
1365 
1366 		case RESPST_DONE:
1367 			if (qp->resp.goto_error) {
1368 				state = RESPST_ERROR;
1369 				break;
1370 			}
1371 
1372 			goto done;
1373 
1374 		case RESPST_EXIT:
1375 			if (qp->resp.goto_error) {
1376 				state = RESPST_ERROR;
1377 				break;
1378 			}
1379 
1380 			goto exit;
1381 
1382 		case RESPST_RESET:
1383 			rxe_drain_req_pkts(qp, false);
1384 			qp->resp.wqe = NULL;
1385 			goto exit;
1386 
1387 		case RESPST_ERROR:
1388 			qp->resp.goto_error = 0;
1389 			pr_warn("qp#%d moved to error state\n", qp_num(qp));
1390 			rxe_qp_error(qp);
1391 			goto exit;
1392 
1393 		default:
1394 			WARN_ON_ONCE(1);
1395 		}
1396 	}
1397 
1398 exit:
1399 	ret = -EAGAIN;
1400 done:
1401 	rxe_drop_ref(qp);
1402 	return ret;
1403 }
1404