rxe_comp.c

  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
 14enum 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
 32static 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
 50static 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
 85static inline unsigned long rnrnak_jiffies(u8 timeout)
 86{
 87	return max_t(unsigned long,
 88		usecs_to_jiffies(rnrnak_usec[timeout]), 1);
 89}
 90
 91static 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	case IB_WR_ATOMIC_WRITE:		return IB_WC_ATOMIC_WRITE;
108	case IB_WR_FLUSH:			return IB_WC_FLUSH;
109
110	default:
111		return 0xff;
112	}
113}
114
115void retransmit_timer(struct timer_list *t)
116{
117	struct rxe_qp *qp = timer_container_of(qp, t, retrans_timer);
118	unsigned long flags;
119
120	rxe_dbg_qp(qp, "retransmit timer fired\n");
121
122	if (!rxe_get(qp))
123		return;
124	spin_lock_irqsave(&qp->state_lock, flags);
125	if (qp->valid) {
126		qp->comp.timeout = 1;
127		rxe_sched_task(&qp->send_task);
128	}
129	spin_unlock_irqrestore(&qp->state_lock, flags);
130	rxe_put(qp);
131}
132
133void rxe_comp_queue_pkt(struct rxe_qp *qp, struct sk_buff *skb)
134{
135	rxe_counter_inc(SKB_TO_PKT(skb)->rxe, RXE_CNT_SENDER_SCHED);
136	skb_queue_tail(&qp->resp_pkts, skb);
137	rxe_sched_task(&qp->send_task);
138}
139
140static inline enum comp_state get_wqe(struct rxe_qp *qp,
141				      struct rxe_pkt_info *pkt,
142				      struct rxe_send_wqe **wqe_p)
143{
144	struct rxe_send_wqe *wqe;
145
146	/* we come here whether or not we found a response packet to see if
147	 * there are any posted WQEs
148	 */
149	wqe = queue_head(qp->sq.queue, QUEUE_TYPE_FROM_CLIENT);
150	*wqe_p = wqe;
151
152	/* no WQE or requester has not started it yet */
153	if (!wqe || wqe->state == wqe_state_posted)
154		return pkt ? COMPST_DONE : COMPST_EXIT;
155
156	/* WQE does not require an ack */
157	if (wqe->state == wqe_state_done)
158		return COMPST_COMP_WQE;
159
160	/* WQE caused an error */
161	if (wqe->state == wqe_state_error)
162		return COMPST_ERROR;
163
164	/* we have a WQE, if we also have an ack check its PSN */
165	return pkt ? COMPST_CHECK_PSN : COMPST_EXIT;
166}
167
168static inline void reset_retry_counters(struct rxe_qp *qp)
169{
170	qp->comp.retry_cnt = qp->attr.retry_cnt;
171	qp->comp.rnr_retry = qp->attr.rnr_retry;
172	qp->comp.started_retry = 0;
173}
174
175static inline enum comp_state check_psn(struct rxe_qp *qp,
176					struct rxe_pkt_info *pkt,
177					struct rxe_send_wqe *wqe)
178{
179	s32 diff;
180
181	/* check to see if response is past the oldest WQE. if it is, complete
182	 * send/write or error read/atomic
183	 */
184	diff = psn_compare(pkt->psn, wqe->last_psn);
185	if (diff > 0) {
186		if (wqe->state == wqe_state_pending) {
187			if (wqe->mask & WR_ATOMIC_OR_READ_MASK)
188				return COMPST_ERROR_RETRY;
189
190			reset_retry_counters(qp);
191			return COMPST_COMP_WQE;
192		} else {
193			return COMPST_DONE;
194		}
195	}
196
197	/* compare response packet to expected response */
198	diff = psn_compare(pkt->psn, qp->comp.psn);
199	if (diff < 0) {
200		/* response is most likely a retried packet if it matches an
201		 * uncompleted WQE go complete it else ignore it
202		 */
203		if (pkt->psn == wqe->last_psn)
204			return COMPST_COMP_ACK;
205		else if (pkt->opcode == IB_OPCODE_RC_ACKNOWLEDGE &&
206			 (qp->comp.opcode == IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST ||
207			  qp->comp.opcode == IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE))
208			return COMPST_CHECK_ACK;
209		else
210			return COMPST_DONE;
211	} else if ((diff > 0) && (wqe->mask & WR_ATOMIC_OR_READ_MASK)) {
212		return COMPST_DONE;
213	} else {
214		return COMPST_CHECK_ACK;
215	}
216}
217
218static inline enum comp_state check_ack(struct rxe_qp *qp,
219					struct rxe_pkt_info *pkt,
220					struct rxe_send_wqe *wqe)
221{
222	unsigned int mask = pkt->mask;
223	u8 syn;
224	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
225
226	/* Check the sequence only */
227	switch (qp->comp.opcode) {
228	case -1:
229		/* Will catch all *_ONLY cases. */
230		if (!(mask & RXE_START_MASK))
231			return COMPST_ERROR;
232
233		break;
234
235	case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST:
236	case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE:
237		/* Check NAK code to handle a remote error */
238		if (pkt->opcode == IB_OPCODE_RC_ACKNOWLEDGE)
239			break;
240
241		if (pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE &&
242		    pkt->opcode != IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST) {
243			/* read retries of partial data may restart from
244			 * read response first or response only.
245			 */
246			if ((pkt->psn == wqe->first_psn &&
247			     pkt->opcode ==
248			     IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) ||
249			    (wqe->first_psn == wqe->last_psn &&
250			     pkt->opcode ==
251			     IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY))
252				break;
253
254			return COMPST_ERROR;
255		}
256		break;
257	default:
258		WARN_ON_ONCE(1);
259	}
260
261	/* Check operation validity. */
262	switch (pkt->opcode) {
263	case IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST:
264	case IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST:
265	case IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY:
266		syn = aeth_syn(pkt);
267
268		if ((syn & AETH_TYPE_MASK) != AETH_ACK)
269			return COMPST_ERROR;
270
271		if (wqe->wr.opcode == IB_WR_ATOMIC_WRITE)
272			return COMPST_WRITE_SEND;
273
274		fallthrough;
275		/* (IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE doesn't have an AETH)
276		 */
277	case IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE:
278		if (wqe->wr.opcode != IB_WR_RDMA_READ &&
279		    wqe->wr.opcode != IB_WR_RDMA_READ_WITH_INV &&
280		    wqe->wr.opcode != IB_WR_FLUSH) {
281			wqe->status = IB_WC_FATAL_ERR;
282			return COMPST_ERROR;
283		}
284		reset_retry_counters(qp);
285		return COMPST_READ;
286
287	case IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE:
288		syn = aeth_syn(pkt);
289
290		if ((syn & AETH_TYPE_MASK) != AETH_ACK)
291			return COMPST_ERROR;
292
293		if (wqe->wr.opcode != IB_WR_ATOMIC_CMP_AND_SWP &&
294		    wqe->wr.opcode != IB_WR_ATOMIC_FETCH_AND_ADD)
295			return COMPST_ERROR;
296		reset_retry_counters(qp);
297		return COMPST_ATOMIC;
298
299	case IB_OPCODE_RC_ACKNOWLEDGE:
300		syn = aeth_syn(pkt);
301		switch (syn & AETH_TYPE_MASK) {
302		case AETH_ACK:
303			reset_retry_counters(qp);
304			return COMPST_WRITE_SEND;
305
306		case AETH_RNR_NAK:
307			rxe_counter_inc(rxe, RXE_CNT_RCV_RNR);
308			return COMPST_RNR_RETRY;
309
310		case AETH_NAK:
311			switch (syn) {
312			case AETH_NAK_PSN_SEQ_ERROR:
313				/* a nak implicitly acks all packets with psns
314				 * before
315				 */
316				if (psn_compare(pkt->psn, qp->comp.psn) > 0) {
317					rxe_counter_inc(rxe,
318							RXE_CNT_RCV_SEQ_ERR);
319					qp->comp.psn = pkt->psn;
320					if (qp->req.wait_psn) {
321						qp->req.wait_psn = 0;
322						qp->req.again = 1;
323					}
324				}
325				return COMPST_ERROR_RETRY;
326
327			case AETH_NAK_INVALID_REQ:
328				wqe->status = IB_WC_REM_INV_REQ_ERR;
329				return COMPST_ERROR;
330
331			case AETH_NAK_REM_ACC_ERR:
332				wqe->status = IB_WC_REM_ACCESS_ERR;
333				return COMPST_ERROR;
334
335			case AETH_NAK_REM_OP_ERR:
336				wqe->status = IB_WC_REM_OP_ERR;
337				return COMPST_ERROR;
338
339			default:
340				rxe_dbg_qp(qp, "unexpected nak %x\n", syn);
341				wqe->status = IB_WC_REM_OP_ERR;
342				return COMPST_ERROR;
343			}
344
345		default:
346			return COMPST_ERROR;
347		}
348		break;
349
350	default:
351		rxe_dbg_qp(qp, "unexpected opcode\n");
352	}
353
354	return COMPST_ERROR;
355}
356
357static inline enum comp_state do_read(struct rxe_qp *qp,
358				      struct rxe_pkt_info *pkt,
359				      struct rxe_send_wqe *wqe)
360{
361	int ret;
362
363	ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE,
364			&wqe->dma, payload_addr(pkt),
365			payload_size(pkt), RXE_TO_MR_OBJ);
366	if (ret) {
367		wqe->status = IB_WC_LOC_PROT_ERR;
368		return COMPST_ERROR;
369	}
370
371	if (wqe->dma.resid == 0 && (pkt->mask & RXE_END_MASK))
372		return COMPST_COMP_ACK;
373
374	return COMPST_UPDATE_COMP;
375}
376
377static inline enum comp_state do_atomic(struct rxe_qp *qp,
378					struct rxe_pkt_info *pkt,
379					struct rxe_send_wqe *wqe)
380{
381	int ret;
382
383	u64 atomic_orig = atmack_orig(pkt);
384
385	ret = copy_data(qp->pd, IB_ACCESS_LOCAL_WRITE,
386			&wqe->dma, &atomic_orig,
387			sizeof(u64), RXE_TO_MR_OBJ);
388	if (ret) {
389		wqe->status = IB_WC_LOC_PROT_ERR;
390		return COMPST_ERROR;
391	}
392
393	return COMPST_COMP_ACK;
394}
395
396static void make_send_cqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe,
397			  struct rxe_cqe *cqe)
398{
399	struct ib_wc *wc = &cqe->ibwc;
400	struct ib_uverbs_wc *uwc = &cqe->uibwc;
401
402	memset(cqe, 0, sizeof(*cqe));
403
404	if (!qp->is_user) {
405		wc->wr_id = wqe->wr.wr_id;
406		wc->status = wqe->status;
407		wc->qp = &qp->ibqp;
408	} else {
409		uwc->wr_id = wqe->wr.wr_id;
410		uwc->status = wqe->status;
411		uwc->qp_num = qp->ibqp.qp_num;
412	}
413
414	if (wqe->status == IB_WC_SUCCESS) {
415		if (!qp->is_user) {
416			wc->opcode = wr_to_wc_opcode(wqe->wr.opcode);
417			if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM ||
418			    wqe->wr.opcode == IB_WR_SEND_WITH_IMM)
419				wc->wc_flags = IB_WC_WITH_IMM;
420			wc->byte_len = wqe->dma.length;
421		} else {
422			uwc->opcode = wr_to_wc_opcode(wqe->wr.opcode);
423			if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM ||
424			    wqe->wr.opcode == IB_WR_SEND_WITH_IMM)
425				uwc->wc_flags = IB_WC_WITH_IMM;
426			uwc->byte_len = wqe->dma.length;
427		}
428	} else {
429		if (wqe->status != IB_WC_WR_FLUSH_ERR)
430			rxe_err_qp(qp, "non-flush error status = %d\n",
431				wqe->status);
432	}
433}
434
435/*
436 * IBA Spec. Section 10.7.3.1 SIGNALED COMPLETIONS
437 * ---------8<---------8<-------------
438 * ...Note that if a completion error occurs, a Work Completion
439 * will always be generated, even if the signaling
440 * indicator requests an Unsignaled Completion.
441 * ---------8<---------8<-------------
442 */
443static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe)
444{
445	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
446	struct rxe_cqe cqe;
447	bool post;
448
449	/* do we need to post a completion */
450	post = ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) ||
451			(wqe->wr.send_flags & IB_SEND_SIGNALED) ||
452			wqe->status != IB_WC_SUCCESS);
453
454	if (post)
455		make_send_cqe(qp, wqe, &cqe);
456
457	queue_advance_consumer(qp->sq.queue, QUEUE_TYPE_FROM_CLIENT);
458
459	if (post)
460		rxe_cq_post(qp->scq, &cqe, 0);
461
462	if (wqe->wr.opcode == IB_WR_SEND ||
463	    wqe->wr.opcode == IB_WR_SEND_WITH_IMM ||
464	    wqe->wr.opcode == IB_WR_SEND_WITH_INV)
465		rxe_counter_inc(rxe, RXE_CNT_RDMA_SEND);
466
467	/*
468	 * we completed something so let req run again
469	 * if it is trying to fence
470	 */
471	if (qp->req.wait_fence) {
472		qp->req.wait_fence = 0;
473		qp->req.again = 1;
474	}
475}
476
477static void comp_check_sq_drain_done(struct rxe_qp *qp)
478{
479	unsigned long flags;
480
481	spin_lock_irqsave(&qp->state_lock, flags);
482	if (unlikely(qp_state(qp) == IB_QPS_SQD)) {
483		if (qp->attr.sq_draining && qp->comp.psn == qp->req.psn) {
484			qp->attr.sq_draining = 0;
485			spin_unlock_irqrestore(&qp->state_lock, flags);
486
487			if (qp->ibqp.event_handler) {
488				struct ib_event ev;
489
490				ev.device = qp->ibqp.device;
491				ev.element.qp = &qp->ibqp;
492				ev.event = IB_EVENT_SQ_DRAINED;
493				qp->ibqp.event_handler(&ev,
494					qp->ibqp.qp_context);
495			}
496			return;
497		}
498	}
499	spin_unlock_irqrestore(&qp->state_lock, flags);
500}
501
502static inline enum comp_state complete_ack(struct rxe_qp *qp,
503					   struct rxe_pkt_info *pkt,
504					   struct rxe_send_wqe *wqe)
505{
506	if (wqe->has_rd_atomic) {
507		wqe->has_rd_atomic = 0;
508		atomic_inc(&qp->req.rd_atomic);
509		if (qp->req.need_rd_atomic) {
510			qp->comp.timeout_retry = 0;
511			qp->req.need_rd_atomic = 0;
512			qp->req.again = 1;
513		}
514	}
515
516	comp_check_sq_drain_done(qp);
517
518	do_complete(qp, wqe);
519
520	if (psn_compare(pkt->psn, qp->comp.psn) >= 0)
521		return COMPST_UPDATE_COMP;
522	else
523		return COMPST_DONE;
524}
525
526static inline enum comp_state complete_wqe(struct rxe_qp *qp,
527					   struct rxe_pkt_info *pkt,
528					   struct rxe_send_wqe *wqe)
529{
530	if (pkt && wqe->state == wqe_state_pending) {
531		if (psn_compare(wqe->last_psn, qp->comp.psn) >= 0) {
532			qp->comp.psn = (wqe->last_psn + 1) & BTH_PSN_MASK;
533			qp->comp.opcode = -1;
534		}
535
536		if (qp->req.wait_psn) {
537			qp->req.wait_psn = 0;
538			qp->req.again = 1;
539		}
540	}
541
542	do_complete(qp, wqe);
543
544	return COMPST_GET_WQE;
545}
546
547/* drain incoming response packet queue */
548static void drain_resp_pkts(struct rxe_qp *qp)
549{
550	struct sk_buff *skb;
551
552	while ((skb = skb_dequeue(&qp->resp_pkts))) {
553		rxe_put(qp);
554		kfree_skb(skb);
555		ib_device_put(qp->ibqp.device);
556	}
557}
558
559/* complete send wqe with flush error */
560static int flush_send_wqe(struct rxe_qp *qp, struct rxe_send_wqe *wqe)
561{
562	struct rxe_cqe cqe = {};
563	struct ib_wc *wc = &cqe.ibwc;
564	struct ib_uverbs_wc *uwc = &cqe.uibwc;
565	int err;
566
567	if (qp->is_user) {
568		uwc->wr_id = wqe->wr.wr_id;
569		uwc->status = IB_WC_WR_FLUSH_ERR;
570		uwc->qp_num = qp->ibqp.qp_num;
571	} else {
572		wc->wr_id = wqe->wr.wr_id;
573		wc->status = IB_WC_WR_FLUSH_ERR;
574		wc->qp = &qp->ibqp;
575	}
576
577	err = rxe_cq_post(qp->scq, &cqe, 0);
578	if (err)
579		rxe_dbg_cq(qp->scq, "post cq failed, err = %d\n", err);
580
581	return err;
582}
583
584/* drain and optionally complete the send queue
585 * if unable to complete a wqe, i.e. cq is full, stop
586 * completing and flush the remaining wqes
587 */
588static void flush_send_queue(struct rxe_qp *qp, bool notify)
589{
590	struct rxe_send_wqe *wqe;
591	struct rxe_queue *q = qp->sq.queue;
592	int err;
593
594	/* send queue never got created. nothing to do. */
595	if (!qp->sq.queue)
596		return;
597
598	while ((wqe = queue_head(q, q->type))) {
599		if (notify) {
600			err = flush_send_wqe(qp, wqe);
601			if (err)
602				notify = 0;
603		}
604		queue_advance_consumer(q, q->type);
605	}
606}
607
608static void free_pkt(struct rxe_pkt_info *pkt)
609{
610	struct sk_buff *skb = PKT_TO_SKB(pkt);
611	struct rxe_qp *qp = pkt->qp;
612	struct ib_device *dev = qp->ibqp.device;
613
614	kfree_skb(skb);
615	rxe_put(qp);
616	ib_device_put(dev);
617}
618
619/* reset the retry timer if
620 * - QP is type RC
621 * - there is a packet sent by the requester that
622 *   might be acked (we still might get spurious
623 *   timeouts but try to keep them as few as possible)
624 * - the timeout parameter is set
625 * - the QP is alive
626 */
627static void reset_retry_timer(struct rxe_qp *qp)
628{
629	unsigned long flags;
630
631	if (qp_type(qp) == IB_QPT_RC && qp->qp_timeout_jiffies) {
632		spin_lock_irqsave(&qp->state_lock, flags);
633		if (qp_state(qp) >= IB_QPS_RTS &&
634		    psn_compare(qp->req.psn, qp->comp.psn) > 0)
635			mod_timer(&qp->retrans_timer,
636				  jiffies + qp->qp_timeout_jiffies);
637		spin_unlock_irqrestore(&qp->state_lock, flags);
638	}
639}
640
641int rxe_completer(struct rxe_qp *qp)
642{
643	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
644	struct rxe_send_wqe *wqe = NULL;
645	struct sk_buff *skb = NULL;
646	struct rxe_pkt_info *pkt = NULL;
647	enum comp_state state;
648	int ret;
649	unsigned long flags;
650
651	qp->req.again = 0;
652
653	spin_lock_irqsave(&qp->state_lock, flags);
654	if (!qp->valid || qp_state(qp) == IB_QPS_ERR ||
655			  qp_state(qp) == IB_QPS_RESET) {
656		bool notify = qp->valid && (qp_state(qp) == IB_QPS_ERR);
657
658		drain_resp_pkts(qp);
659		flush_send_queue(qp, notify);
660		spin_unlock_irqrestore(&qp->state_lock, flags);
661		goto exit;
662	}
663	spin_unlock_irqrestore(&qp->state_lock, flags);
664
665	if (qp->comp.timeout) {
666		qp->comp.timeout_retry = 1;
667		qp->comp.timeout = 0;
668	} else {
669		qp->comp.timeout_retry = 0;
670	}
671
672	if (qp->req.need_retry)
673		goto exit;
674
675	state = COMPST_GET_ACK;
676
677	while (1) {
678		rxe_dbg_qp(qp, "state = %s\n", comp_state_name[state]);
679		switch (state) {
680		case COMPST_GET_ACK:
681			skb = skb_dequeue(&qp->resp_pkts);
682			if (skb) {
683				pkt = SKB_TO_PKT(skb);
684				qp->comp.timeout_retry = 0;
685			}
686			state = COMPST_GET_WQE;
687			break;
688
689		case COMPST_GET_WQE:
690			state = get_wqe(qp, pkt, &wqe);
691			break;
692
693		case COMPST_CHECK_PSN:
694			state = check_psn(qp, pkt, wqe);
695			break;
696
697		case COMPST_CHECK_ACK:
698			state = check_ack(qp, pkt, wqe);
699			break;
700
701		case COMPST_READ:
702			state = do_read(qp, pkt, wqe);
703			break;
704
705		case COMPST_ATOMIC:
706			state = do_atomic(qp, pkt, wqe);
707			break;
708
709		case COMPST_WRITE_SEND:
710			if (wqe->state == wqe_state_pending &&
711			    wqe->last_psn == pkt->psn)
712				state = COMPST_COMP_ACK;
713			else
714				state = COMPST_UPDATE_COMP;
715			break;
716
717		case COMPST_COMP_ACK:
718			state = complete_ack(qp, pkt, wqe);
719			break;
720
721		case COMPST_COMP_WQE:
722			state = complete_wqe(qp, pkt, wqe);
723			break;
724
725		case COMPST_UPDATE_COMP:
726			if (pkt->mask & RXE_END_MASK)
727				qp->comp.opcode = -1;
728			else
729				qp->comp.opcode = pkt->opcode;
730
731			if (psn_compare(pkt->psn, qp->comp.psn) >= 0)
732				qp->comp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
733
734			if (qp->req.wait_psn) {
735				qp->req.wait_psn = 0;
736				qp->req.again = 1;
737			}
738
739			state = COMPST_DONE;
740			break;
741
742		case COMPST_DONE:
743			goto done;
744
745		case COMPST_EXIT:
746			if (qp->comp.timeout_retry && wqe) {
747				state = COMPST_ERROR_RETRY;
748				break;
749			}
750
751			reset_retry_timer(qp);
752			goto exit;
753
754		case COMPST_ERROR_RETRY:
755			/* we come here if the retry timer fired and we did
756			 * not receive a response packet. try to retry the send
757			 * queue if that makes sense and the limits have not
758			 * been exceeded. remember that some timeouts are
759			 * spurious since we do not reset the timer but kick
760			 * it down the road or let it expire
761			 */
762
763			/* there is nothing to retry in this case */
764			if (!wqe || (wqe->state == wqe_state_posted))
765				goto exit;
766
767			/* if we've started a retry, don't start another
768			 * retry sequence, unless this is a timeout.
769			 */
770			if (qp->comp.started_retry &&
771			    !qp->comp.timeout_retry)
772				goto done;
773
774			if (qp->comp.retry_cnt > 0) {
775				if (qp->comp.retry_cnt != 7)
776					qp->comp.retry_cnt--;
777
778				/* no point in retrying if we have already
779				 * seen the last ack that the requester could
780				 * have caused
781				 */
782				if (psn_compare(qp->req.psn,
783						qp->comp.psn) > 0) {
784					/* tell the requester to retry the
785					 * send queue next time around
786					 */
787					rxe_counter_inc(rxe,
788							RXE_CNT_COMP_RETRY);
789					qp->req.need_retry = 1;
790					qp->comp.started_retry = 1;
791					qp->req.again = 1;
792				}
793				goto done;
794
795			} else {
796				rxe_counter_inc(rxe, RXE_CNT_RETRY_EXCEEDED);
797				wqe->status = IB_WC_RETRY_EXC_ERR;
798				state = COMPST_ERROR;
799			}
800			break;
801
802		case COMPST_RNR_RETRY:
803			/* we come here if we received an RNR NAK */
804			if (qp->comp.rnr_retry > 0) {
805				if (qp->comp.rnr_retry != 7)
806					qp->comp.rnr_retry--;
807
808				/* don't start a retry flow until the
809				 * rnr timer has fired
810				 */
811				qp->req.wait_for_rnr_timer = 1;
812				rxe_dbg_qp(qp, "set rnr nak timer\n");
813				// TODO who protects from destroy_qp??
814				mod_timer(&qp->rnr_nak_timer,
815					  jiffies + rnrnak_jiffies(aeth_syn(pkt)
816						& ~AETH_TYPE_MASK));
817				goto exit;
818			} else {
819				rxe_counter_inc(rxe,
820						RXE_CNT_RNR_RETRY_EXCEEDED);
821				wqe->status = IB_WC_RNR_RETRY_EXC_ERR;
822				state = COMPST_ERROR;
823			}
824			break;
825
826		case COMPST_ERROR:
827			WARN_ON_ONCE(wqe->status == IB_WC_SUCCESS);
828			do_complete(qp, wqe);
829			rxe_qp_error(qp);
830			goto exit;
831		}
832	}
833
834	/* A non-zero return value will cause rxe_do_task to
835	 * exit its loop and end the work item. A zero return
836	 * will continue looping and return to rxe_completer
837	 */
838done:
839	ret = 0;
840	goto out;
841exit:
842	ret = (qp->req.again) ? 0 : -EAGAIN;
843out:
844	qp->req.again = 0;
845	if (pkt)
846		free_pkt(pkt);
847	return ret;
848}