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