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 #include "rxe_task.h"
13
14 enum comp_state {
15 COMPST_GET_ACK,
16 COMPST_GET_WQE,
17 COMPST_COMP_WQE,
18 COMPST_COMP_ACK,
19 COMPST_CHECK_PSN,
20 COMPST_CHECK_ACK,
21 COMPST_READ,
22 COMPST_ATOMIC,
23 COMPST_WRITE_SEND,
24 COMPST_UPDATE_COMP,
25 COMPST_ERROR_RETRY,
26 COMPST_RNR_RETRY,
27 COMPST_ERROR,
28 COMPST_EXIT, /* We have an issue, and we want to rerun the completer */
29 COMPST_DONE, /* The completer finished successflly */
30 };
31
32 static char *comp_state_name[] = {
33 [COMPST_GET_ACK] = "GET ACK",
34 [COMPST_GET_WQE] = "GET WQE",
35 [COMPST_COMP_WQE] = "COMP WQE",
36 [COMPST_COMP_ACK] = "COMP ACK",
37 [COMPST_CHECK_PSN] = "CHECK PSN",
38 [COMPST_CHECK_ACK] = "CHECK ACK",
39 [COMPST_READ] = "READ",
40 [COMPST_ATOMIC] = "ATOMIC",
41 [COMPST_WRITE_SEND] = "WRITE/SEND",
42 [COMPST_UPDATE_COMP] = "UPDATE COMP",
43 [COMPST_ERROR_RETRY] = "ERROR RETRY",
44 [COMPST_RNR_RETRY] = "RNR RETRY",
45 [COMPST_ERROR] = "ERROR",
46 [COMPST_EXIT] = "EXIT",
47 [COMPST_DONE] = "DONE",
48 };
49
50 static unsigned long rnrnak_usec[32] = {
51 [IB_RNR_TIMER_655_36] = 655360,
52 [IB_RNR_TIMER_000_01] = 10,
53 [IB_RNR_TIMER_000_02] = 20,
54 [IB_RNR_TIMER_000_03] = 30,
55 [IB_RNR_TIMER_000_04] = 40,
56 [IB_RNR_TIMER_000_06] = 60,
57 [IB_RNR_TIMER_000_08] = 80,
58 [IB_RNR_TIMER_000_12] = 120,
59 [IB_RNR_TIMER_000_16] = 160,
60 [IB_RNR_TIMER_000_24] = 240,
61 [IB_RNR_TIMER_000_32] = 320,
62 [IB_RNR_TIMER_000_48] = 480,
63 [IB_RNR_TIMER_000_64] = 640,
64 [IB_RNR_TIMER_000_96] = 960,
65 [IB_RNR_TIMER_001_28] = 1280,
66 [IB_RNR_TIMER_001_92] = 1920,
67 [IB_RNR_TIMER_002_56] = 2560,
68 [IB_RNR_TIMER_003_84] = 3840,
69 [IB_RNR_TIMER_005_12] = 5120,
70 [IB_RNR_TIMER_007_68] = 7680,
71 [IB_RNR_TIMER_010_24] = 10240,
72 [IB_RNR_TIMER_015_36] = 15360,
73 [IB_RNR_TIMER_020_48] = 20480,
74 [IB_RNR_TIMER_030_72] = 30720,
75 [IB_RNR_TIMER_040_96] = 40960,
76 [IB_RNR_TIMER_061_44] = 61410,
77 [IB_RNR_TIMER_081_92] = 81920,
78 [IB_RNR_TIMER_122_88] = 122880,
79 [IB_RNR_TIMER_163_84] = 163840,
80 [IB_RNR_TIMER_245_76] = 245760,
81 [IB_RNR_TIMER_327_68] = 327680,
82 [IB_RNR_TIMER_491_52] = 491520,
83 };
84
rnrnak_jiffies(u8 timeout)85 static inline unsigned long rnrnak_jiffies(u8 timeout)
86 {
87 return max_t(unsigned long,
88 usecs_to_jiffies(rnrnak_usec[timeout]), 1);
89 }
90
wr_to_wc_opcode(enum ib_wr_opcode opcode)91 static enum ib_wc_opcode wr_to_wc_opcode(enum ib_wr_opcode opcode)
92 {
93 switch (opcode) {
94 case IB_WR_RDMA_WRITE: return IB_WC_RDMA_WRITE;
95 case IB_WR_RDMA_WRITE_WITH_IMM: return IB_WC_RDMA_WRITE;
96 case IB_WR_SEND: return IB_WC_SEND;
97 case IB_WR_SEND_WITH_IMM: return IB_WC_SEND;
98 case IB_WR_RDMA_READ: return IB_WC_RDMA_READ;
99 case IB_WR_ATOMIC_CMP_AND_SWP: return IB_WC_COMP_SWAP;
100 case IB_WR_ATOMIC_FETCH_AND_ADD: return IB_WC_FETCH_ADD;
101 case IB_WR_LSO: return IB_WC_LSO;
102 case IB_WR_SEND_WITH_INV: return IB_WC_SEND;
103 case IB_WR_RDMA_READ_WITH_INV: return IB_WC_RDMA_READ;
104 case IB_WR_LOCAL_INV: return IB_WC_LOCAL_INV;
105 case IB_WR_REG_MR: return IB_WC_REG_MR;
106 case IB_WR_BIND_MW: return IB_WC_BIND_MW;
107
108 default:
109 return 0xff;
110 }
111 }
112
retransmit_timer(struct timer_list * t)113 void retransmit_timer(struct timer_list *t)
114 {
115 struct rxe_qp *qp = from_timer(qp, t, retrans_timer);
116
117 if (qp->valid) {
118 qp->comp.timeout = 1;
119 rxe_run_task(&qp->comp.task, 1);
120 }
121 }
122
rxe_comp_queue_pkt(struct rxe_qp * qp,struct sk_buff * skb)123 void rxe_comp_queue_pkt(struct rxe_qp *qp, struct sk_buff *skb)
124 {
125 int must_sched;
126
127 skb_queue_tail(&qp->resp_pkts, skb);
128
129 must_sched = skb_queue_len(&qp->resp_pkts) > 1;
130 if (must_sched != 0)
131 rxe_counter_inc(SKB_TO_PKT(skb)->rxe, RXE_CNT_COMPLETER_SCHED);
132
133 rxe_run_task(&qp->comp.task, must_sched);
134 }
135
get_wqe(struct rxe_qp * qp,struct rxe_pkt_info * pkt,struct rxe_send_wqe ** wqe_p)136 static inline enum comp_state get_wqe(struct rxe_qp *qp,
137 struct rxe_pkt_info *pkt,
138 struct rxe_send_wqe **wqe_p)
139 {
140 struct rxe_send_wqe *wqe;
141
142 /* we come here whether or not we found a response packet to see if
143 * there are any posted WQEs
144 */
145 if (qp->is_user)
146 wqe = queue_head(qp->sq.queue, QUEUE_TYPE_FROM_USER);
147 else
148 wqe = queue_head(qp->sq.queue, QUEUE_TYPE_KERNEL);
149 *wqe_p = wqe;
150
151 /* no WQE or requester has not started it yet */
152 if (!wqe || wqe->state == wqe_state_posted)
153 return pkt ? COMPST_DONE : COMPST_EXIT;
154
155 /* WQE does not require an ack */
156 if (wqe->state == wqe_state_done)
157 return COMPST_COMP_WQE;
158
159 /* WQE caused an error */
160 if (wqe->state == wqe_state_error)
161 return COMPST_ERROR;
162
163 /* we have a WQE, if we also have an ack check its PSN */
164 return pkt ? COMPST_CHECK_PSN : COMPST_EXIT;
165 }
166
reset_retry_counters(struct rxe_qp * qp)167 static inline void reset_retry_counters(struct rxe_qp *qp)
168 {
169 qp->comp.retry_cnt = qp->attr.retry_cnt;
170 qp->comp.rnr_retry = qp->attr.rnr_retry;
171 qp->comp.started_retry = 0;
172 }
173
check_psn(struct rxe_qp * qp,struct rxe_pkt_info * pkt,struct rxe_send_wqe * wqe)174 static inline enum comp_state check_psn(struct rxe_qp *qp,
175 struct rxe_pkt_info *pkt,
176 struct rxe_send_wqe *wqe)
177 {
178 s32 diff;
179
180 /* check to see if response is past the oldest WQE. if it is, complete
181 * send/write or error read/atomic
182 */
183 diff = psn_compare(pkt->psn, wqe->last_psn);
184 if (diff > 0) {
185 if (wqe->state == wqe_state_pending) {
186 if (wqe->mask & WR_ATOMIC_OR_READ_MASK)
187 return COMPST_ERROR_RETRY;
188
189 reset_retry_counters(qp);
190 return COMPST_COMP_WQE;
191 } else {
192 return COMPST_DONE;
193 }
194 }
195
196 /* compare response packet to expected response */
197 diff = psn_compare(pkt->psn, qp->comp.psn);
198 if (diff < 0) {
199 /* response is most likely a retried packet if it matches an
200 * uncompleted WQE go complete it else ignore it
201 */
202 if (pkt->psn == wqe->last_psn)
203 return COMPST_COMP_ACK;
204 else
205 return COMPST_DONE;
206 } else if ((diff > 0) && (wqe->mask & WR_ATOMIC_OR_READ_MASK)) {
207 return COMPST_DONE;
208 } else {
209 return COMPST_CHECK_ACK;
210 }
211 }
212
check_ack(struct rxe_qp * qp,struct rxe_pkt_info * pkt,struct rxe_send_wqe * wqe)213 static inline enum comp_state check_ack(struct rxe_qp *qp,
214 struct rxe_pkt_info *pkt,
215 struct rxe_send_wqe *wqe)
216 {
217 unsigned int mask = pkt->mask;
218 u8 syn;
219 struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
220
221 /* Check the sequence only */
222 switch (qp->comp.opcode) {
223 case -1:
224 /* Will catch all *_ONLY cases. */
225 if (!(mask & RXE_START_MASK))
226 return COMPST_ERROR;
227
228 break;
229
230 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST:
231 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE:
232 if (pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE &&
233 pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST) {
234 /* read retries of partial data may restart from
235 * read response first or response only.
236 */
237 if ((pkt->psn == wqe->first_psn &&
238 pkt->opcode ==
239 IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) ||
240 (wqe->first_psn == wqe->last_psn &&
241 pkt->opcode ==
242 IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY))
243 break;
244
245 return COMPST_ERROR;
246 }
247 break;
248 default:
249 WARN_ON_ONCE(1);
250 }
251
252 /* Check operation validity. */
253 switch (pkt->opcode) {
254 case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST:
255 case IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST:
256 case IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY:
257 syn = aeth_syn(pkt);
258
259 if ((syn & AETH_TYPE_MASK) != AETH_ACK)
260 return COMPST_ERROR;
261
262 fallthrough;
263 /* (IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE doesn't have an AETH)
264 */
265 case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE:
266 if (wqe->wr.opcode != IB_WR_RDMA_READ &&
267 wqe->wr.opcode != IB_WR_RDMA_READ_WITH_INV) {
268 wqe->status = IB_WC_FATAL_ERR;
269 return COMPST_ERROR;
270 }
271 reset_retry_counters(qp);
272 return COMPST_READ;
273
274 case IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE:
275 syn = aeth_syn(pkt);
276
277 if ((syn & AETH_TYPE_MASK) != AETH_ACK)
278 return COMPST_ERROR;
279
280 if (wqe->wr.opcode != IB_WR_ATOMIC_CMP_AND_SWP &&
281 wqe->wr.opcode != IB_WR_ATOMIC_FETCH_AND_ADD)
282 return COMPST_ERROR;
283 reset_retry_counters(qp);
284 return COMPST_ATOMIC;
285
286 case IB_OPCODE_RC_ACKNOWLEDGE:
287 syn = aeth_syn(pkt);
288 switch (syn & AETH_TYPE_MASK) {
289 case AETH_ACK:
290 reset_retry_counters(qp);
291 return COMPST_WRITE_SEND;
292
293 case AETH_RNR_NAK:
294 rxe_counter_inc(rxe, RXE_CNT_RCV_RNR);
295 return COMPST_RNR_RETRY;
296
297 case AETH_NAK:
298 switch (syn) {
299 case AETH_NAK_PSN_SEQ_ERROR:
300 /* a nak implicitly acks all packets with psns
301 * before
302 */
303 if (psn_compare(pkt->psn, qp->comp.psn) > 0) {
304 rxe_counter_inc(rxe,
305 RXE_CNT_RCV_SEQ_ERR);
306 qp->comp.psn = pkt->psn;
307 if (qp->req.wait_psn) {
308 qp->req.wait_psn = 0;
309 rxe_run_task(&qp->req.task, 0);
310 }
311 }
312 return COMPST_ERROR_RETRY;
313
314 case AETH_NAK_INVALID_REQ:
315 wqe->status = IB_WC_REM_INV_REQ_ERR;
316 return COMPST_ERROR;
317
318 case AETH_NAK_REM_ACC_ERR:
319 wqe->status = IB_WC_REM_ACCESS_ERR;
320 return COMPST_ERROR;
321
322 case AETH_NAK_REM_OP_ERR:
323 wqe->status = IB_WC_REM_OP_ERR;
324 return COMPST_ERROR;
325
326 default:
327 pr_warn("unexpected nak %x\n", syn);
328 wqe->status = IB_WC_REM_OP_ERR;
329 return COMPST_ERROR;
330 }
331
332 default:
333 return COMPST_ERROR;
334 }
335 break;
336
337 default:
338 pr_warn("unexpected opcode\n");
339 }
340
341 return COMPST_ERROR;
342 }
343
do_read(struct rxe_qp * qp,struct rxe_pkt_info * pkt,struct rxe_send_wqe * wqe)344 static inline enum comp_state do_read(struct rxe_qp *qp,
345 struct rxe_pkt_info *pkt,
346 struct rxe_send_wqe *wqe)
347 {
348 int ret;
349
350 ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE,
351 &wqe->dma, payload_addr(pkt),
352 payload_size(pkt), RXE_TO_MR_OBJ);
353 if (ret) {
354 wqe->status = IB_WC_LOC_PROT_ERR;
355 return COMPST_ERROR;
356 }
357
358 if (wqe->dma.resid == 0 && (pkt->mask & RXE_END_MASK))
359 return COMPST_COMP_ACK;
360
361 return COMPST_UPDATE_COMP;
362 }
363
do_atomic(struct rxe_qp * qp,struct rxe_pkt_info * pkt,struct rxe_send_wqe * wqe)364 static inline enum comp_state do_atomic(struct rxe_qp *qp,
365 struct rxe_pkt_info *pkt,
366 struct rxe_send_wqe *wqe)
367 {
368 int ret;
369
370 u64 atomic_orig = atmack_orig(pkt);
371
372 ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE,
373 &wqe->dma, &atomic_orig,
374 sizeof(u64), RXE_TO_MR_OBJ);
375 if (ret) {
376 wqe->status = IB_WC_LOC_PROT_ERR;
377 return COMPST_ERROR;
378 }
379
380 return COMPST_COMP_ACK;
381 }
382
make_send_cqe(struct rxe_qp * qp,struct rxe_send_wqe * wqe,struct rxe_cqe * cqe)383 static void make_send_cqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe,
384 struct rxe_cqe *cqe)
385 {
386 memset(cqe, 0, sizeof(*cqe));
387
388 if (!qp->is_user) {
389 struct ib_wc *wc = &cqe->ibwc;
390
391 wc->wr_id = wqe->wr.wr_id;
392 wc->status = wqe->status;
393 wc->opcode = wr_to_wc_opcode(wqe->wr.opcode);
394 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM ||
395 wqe->wr.opcode == IB_WR_SEND_WITH_IMM)
396 wc->wc_flags = IB_WC_WITH_IMM;
397 wc->byte_len = wqe->dma.length;
398 wc->qp = &qp->ibqp;
399 } else {
400 struct ib_uverbs_wc *uwc = &cqe->uibwc;
401
402 uwc->wr_id = wqe->wr.wr_id;
403 uwc->status = wqe->status;
404 uwc->opcode = wr_to_wc_opcode(wqe->wr.opcode);
405 if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM ||
406 wqe->wr.opcode == IB_WR_SEND_WITH_IMM)
407 uwc->wc_flags = IB_WC_WITH_IMM;
408 uwc->byte_len = wqe->dma.length;
409 uwc->qp_num = qp->ibqp.qp_num;
410 }
411 }
412
413 /*
414 * IBA Spec. Section 10.7.3.1 SIGNALED COMPLETIONS
415 * ---------8<---------8<-------------
416 * ...Note that if a completion error occurs, a Work Completion
417 * will always be generated, even if the signaling
418 * indicator requests an Unsignaled Completion.
419 * ---------8<---------8<-------------
420 */
do_complete(struct rxe_qp * qp,struct rxe_send_wqe * wqe)421 static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe)
422 {
423 struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
424 struct rxe_cqe cqe;
425 bool post;
426
427 /* do we need to post a completion */
428 post = ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) ||
429 (wqe->wr.send_flags & IB_SEND_SIGNALED) ||
430 wqe->status != IB_WC_SUCCESS);
431
432 if (post)
433 make_send_cqe(qp, wqe, &cqe);
434
435 if (qp->is_user)
436 advance_consumer(qp->sq.queue, QUEUE_TYPE_FROM_USER);
437 else
438 advance_consumer(qp->sq.queue, QUEUE_TYPE_KERNEL);
439
440 if (post)
441 rxe_cq_post(qp->scq, &cqe, 0);
442
443 if (wqe->wr.opcode == IB_WR_SEND ||
444 wqe->wr.opcode == IB_WR_SEND_WITH_IMM ||
445 wqe->wr.opcode == IB_WR_SEND_WITH_INV)
446 rxe_counter_inc(rxe, RXE_CNT_RDMA_SEND);
447
448 /*
449 * we completed something so let req run again
450 * if it is trying to fence
451 */
452 if (qp->req.wait_fence) {
453 qp->req.wait_fence = 0;
454 rxe_run_task(&qp->req.task, 0);
455 }
456 }
457
complete_ack(struct rxe_qp * qp,struct rxe_pkt_info * pkt,struct rxe_send_wqe * wqe)458 static inline enum comp_state complete_ack(struct rxe_qp *qp,
459 struct rxe_pkt_info *pkt,
460 struct rxe_send_wqe *wqe)
461 {
462 unsigned long flags;
463
464 if (wqe->has_rd_atomic) {
465 wqe->has_rd_atomic = 0;
466 atomic_inc(&qp->req.rd_atomic);
467 if (qp->req.need_rd_atomic) {
468 qp->comp.timeout_retry = 0;
469 qp->req.need_rd_atomic = 0;
470 rxe_run_task(&qp->req.task, 0);
471 }
472 }
473
474 if (unlikely(qp->req.state == QP_STATE_DRAIN)) {
475 /* state_lock used by requester & completer */
476 spin_lock_irqsave(&qp->state_lock, flags);
477 if ((qp->req.state == QP_STATE_DRAIN) &&
478 (qp->comp.psn == qp->req.psn)) {
479 qp->req.state = QP_STATE_DRAINED;
480 spin_unlock_irqrestore(&qp->state_lock, flags);
481
482 if (qp->ibqp.event_handler) {
483 struct ib_event ev;
484
485 ev.device = qp->ibqp.device;
486 ev.element.qp = &qp->ibqp;
487 ev.event = IB_EVENT_SQ_DRAINED;
488 qp->ibqp.event_handler(&ev,
489 qp->ibqp.qp_context);
490 }
491 } else {
492 spin_unlock_irqrestore(&qp->state_lock, flags);
493 }
494 }
495
496 do_complete(qp, wqe);
497
498 if (psn_compare(pkt->psn, qp->comp.psn) >= 0)
499 return COMPST_UPDATE_COMP;
500 else
501 return COMPST_DONE;
502 }
503
complete_wqe(struct rxe_qp * qp,struct rxe_pkt_info * pkt,struct rxe_send_wqe * wqe)504 static inline enum comp_state complete_wqe(struct rxe_qp *qp,
505 struct rxe_pkt_info *pkt,
506 struct rxe_send_wqe *wqe)
507 {
508 if (pkt && wqe->state == wqe_state_pending) {
509 if (psn_compare(wqe->last_psn, qp->comp.psn) >= 0) {
510 qp->comp.psn = (wqe->last_psn + 1) & BTH_PSN_MASK;
511 qp->comp.opcode = -1;
512 }
513
514 if (qp->req.wait_psn) {
515 qp->req.wait_psn = 0;
516 rxe_run_task(&qp->req.task, 1);
517 }
518 }
519
520 do_complete(qp, wqe);
521
522 return COMPST_GET_WQE;
523 }
524
rxe_drain_resp_pkts(struct rxe_qp * qp,bool notify)525 static void rxe_drain_resp_pkts(struct rxe_qp *qp, bool notify)
526 {
527 struct sk_buff *skb;
528 struct rxe_send_wqe *wqe;
529 struct rxe_queue *q = qp->sq.queue;
530
531 while ((skb = skb_dequeue(&qp->resp_pkts))) {
532 rxe_drop_ref(qp);
533 kfree_skb(skb);
534 ib_device_put(qp->ibqp.device);
535 }
536
537 while ((wqe = queue_head(q, q->type))) {
538 if (notify) {
539 wqe->status = IB_WC_WR_FLUSH_ERR;
540 do_complete(qp, wqe);
541 } else {
542 advance_consumer(q, q->type);
543 }
544 }
545 }
546
free_pkt(struct rxe_pkt_info * pkt)547 static void free_pkt(struct rxe_pkt_info *pkt)
548 {
549 struct sk_buff *skb = PKT_TO_SKB(pkt);
550 struct rxe_qp *qp = pkt->qp;
551 struct ib_device *dev = qp->ibqp.device;
552
553 kfree_skb(skb);
554 rxe_drop_ref(qp);
555 ib_device_put(dev);
556 }
557
rxe_completer(void * arg)558 int rxe_completer(void *arg)
559 {
560 struct rxe_qp *qp = (struct rxe_qp *)arg;
561 struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
562 struct rxe_send_wqe *wqe = NULL;
563 struct sk_buff *skb = NULL;
564 struct rxe_pkt_info *pkt = NULL;
565 enum comp_state state;
566 int ret = 0;
567
568 rxe_add_ref(qp);
569
570 if (!qp->valid || qp->req.state == QP_STATE_ERROR ||
571 qp->req.state == QP_STATE_RESET) {
572 rxe_drain_resp_pkts(qp, qp->valid &&
573 qp->req.state == QP_STATE_ERROR);
574 ret = -EAGAIN;
575 goto done;
576 }
577
578 if (qp->comp.timeout) {
579 qp->comp.timeout_retry = 1;
580 qp->comp.timeout = 0;
581 } else {
582 qp->comp.timeout_retry = 0;
583 }
584
585 if (qp->req.need_retry) {
586 ret = -EAGAIN;
587 goto done;
588 }
589
590 state = COMPST_GET_ACK;
591
592 while (1) {
593 pr_debug("qp#%d state = %s\n", qp_num(qp),
594 comp_state_name[state]);
595 switch (state) {
596 case COMPST_GET_ACK:
597 skb = skb_dequeue(&qp->resp_pkts);
598 if (skb) {
599 pkt = SKB_TO_PKT(skb);
600 qp->comp.timeout_retry = 0;
601 }
602 state = COMPST_GET_WQE;
603 break;
604
605 case COMPST_GET_WQE:
606 state = get_wqe(qp, pkt, &wqe);
607 break;
608
609 case COMPST_CHECK_PSN:
610 state = check_psn(qp, pkt, wqe);
611 break;
612
613 case COMPST_CHECK_ACK:
614 state = check_ack(qp, pkt, wqe);
615 break;
616
617 case COMPST_READ:
618 state = do_read(qp, pkt, wqe);
619 break;
620
621 case COMPST_ATOMIC:
622 state = do_atomic(qp, pkt, wqe);
623 break;
624
625 case COMPST_WRITE_SEND:
626 if (wqe->state == wqe_state_pending &&
627 wqe->last_psn == pkt->psn)
628 state = COMPST_COMP_ACK;
629 else
630 state = COMPST_UPDATE_COMP;
631 break;
632
633 case COMPST_COMP_ACK:
634 state = complete_ack(qp, pkt, wqe);
635 break;
636
637 case COMPST_COMP_WQE:
638 state = complete_wqe(qp, pkt, wqe);
639 break;
640
641 case COMPST_UPDATE_COMP:
642 if (pkt->mask & RXE_END_MASK)
643 qp->comp.opcode = -1;
644 else
645 qp->comp.opcode = pkt->opcode;
646
647 if (psn_compare(pkt->psn, qp->comp.psn) >= 0)
648 qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
649
650 if (qp->req.wait_psn) {
651 qp->req.wait_psn = 0;
652 rxe_run_task(&qp->req.task, 1);
653 }
654
655 state = COMPST_DONE;
656 break;
657
658 case COMPST_DONE:
659 goto done;
660
661 case COMPST_EXIT:
662 if (qp->comp.timeout_retry && wqe) {
663 state = COMPST_ERROR_RETRY;
664 break;
665 }
666
667 /* re reset the timeout counter if
668 * (1) QP is type RC
669 * (2) the QP is alive
670 * (3) there is a packet sent by the requester that
671 * might be acked (we still might get spurious
672 * timeouts but try to keep them as few as possible)
673 * (4) the timeout parameter is set
674 */
675 if ((qp_type(qp) == IB_QPT_RC) &&
676 (qp->req.state == QP_STATE_READY) &&
677 (psn_compare(qp->req.psn, qp->comp.psn) > 0) &&
678 qp->qp_timeout_jiffies)
679 mod_timer(&qp->retrans_timer,
680 jiffies + qp->qp_timeout_jiffies);
681 ret = -EAGAIN;
682 goto done;
683
684 case COMPST_ERROR_RETRY:
685 /* we come here if the retry timer fired and we did
686 * not receive a response packet. try to retry the send
687 * queue if that makes sense and the limits have not
688 * been exceeded. remember that some timeouts are
689 * spurious since we do not reset the timer but kick
690 * it down the road or let it expire
691 */
692
693 /* there is nothing to retry in this case */
694 if (!wqe || (wqe->state == wqe_state_posted)) {
695 ret = -EAGAIN;
696 goto done;
697 }
698
699 /* if we've started a retry, don't start another
700 * retry sequence, unless this is a timeout.
701 */
702 if (qp->comp.started_retry &&
703 !qp->comp.timeout_retry)
704 goto done;
705
706 if (qp->comp.retry_cnt > 0) {
707 if (qp->comp.retry_cnt != 7)
708 qp->comp.retry_cnt--;
709
710 /* no point in retrying if we have already
711 * seen the last ack that the requester could
712 * have caused
713 */
714 if (psn_compare(qp->req.psn,
715 qp->comp.psn) > 0) {
716 /* tell the requester to retry the
717 * send queue next time around
718 */
719 rxe_counter_inc(rxe,
720 RXE_CNT_COMP_RETRY);
721 qp->req.need_retry = 1;
722 qp->comp.started_retry = 1;
723 rxe_run_task(&qp->req.task, 0);
724 }
725 goto done;
726
727 } else {
728 rxe_counter_inc(rxe, RXE_CNT_RETRY_EXCEEDED);
729 wqe->status = IB_WC_RETRY_EXC_ERR;
730 state = COMPST_ERROR;
731 }
732 break;
733
734 case COMPST_RNR_RETRY:
735 if (qp->comp.rnr_retry > 0) {
736 if (qp->comp.rnr_retry != 7)
737 qp->comp.rnr_retry--;
738
739 qp->req.need_retry = 1;
740 pr_debug("qp#%d set rnr nak timer\n",
741 qp_num(qp));
742 mod_timer(&qp->rnr_nak_timer,
743 jiffies + rnrnak_jiffies(aeth_syn(pkt)
744 & ~AETH_TYPE_MASK));
745 ret = -EAGAIN;
746 goto done;
747 } else {
748 rxe_counter_inc(rxe,
749 RXE_CNT_RNR_RETRY_EXCEEDED);
750 wqe->status = IB_WC_RNR_RETRY_EXC_ERR;
751 state = COMPST_ERROR;
752 }
753 break;
754
755 case COMPST_ERROR:
756 WARN_ON_ONCE(wqe->status == IB_WC_SUCCESS);
757 do_complete(qp, wqe);
758 rxe_qp_error(qp);
759 ret = -EAGAIN;
760 goto done;
761 }
762 }
763
764 done:
765 if (pkt)
766 free_pkt(pkt);
767 rxe_drop_ref(qp);
768
769 return ret;
770 }
771
