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