1 /*
2 * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved.
3 * Copyright (c) 2005, 2006 PathScale, 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/io.h>
35
36 #include "qib.h"
37
38 /* cut down ridiculously long IB macro names */
39 #define OP(x) IB_OPCODE_RC_##x
40
41 static void rc_timeout(unsigned long arg);
42
restart_sge(struct qib_sge_state * ss,struct qib_swqe * wqe,u32 psn,u32 pmtu)43 static u32 restart_sge(struct qib_sge_state *ss, struct qib_swqe *wqe,
44 u32 psn, u32 pmtu)
45 {
46 u32 len;
47
48 len = ((psn - wqe->psn) & QIB_PSN_MASK) * pmtu;
49 ss->sge = wqe->sg_list[0];
50 ss->sg_list = wqe->sg_list + 1;
51 ss->num_sge = wqe->wr.num_sge;
52 ss->total_len = wqe->length;
53 qib_skip_sge(ss, len, 0);
54 return wqe->length - len;
55 }
56
start_timer(struct qib_qp * qp)57 static void start_timer(struct qib_qp *qp)
58 {
59 qp->s_flags |= QIB_S_TIMER;
60 qp->s_timer.function = rc_timeout;
61 /* 4.096 usec. * (1 << qp->timeout) */
62 qp->s_timer.expires = jiffies + qp->timeout_jiffies;
63 add_timer(&qp->s_timer);
64 }
65
66 /**
67 * qib_make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
68 * @dev: the device for this QP
69 * @qp: a pointer to the QP
70 * @ohdr: a pointer to the IB header being constructed
71 * @pmtu: the path MTU
72 *
73 * Return 1 if constructed; otherwise, return 0.
74 * Note that we are in the responder's side of the QP context.
75 * Note the QP s_lock must be held.
76 */
qib_make_rc_ack(struct qib_ibdev * dev,struct qib_qp * qp,struct qib_other_headers * ohdr,u32 pmtu)77 static int qib_make_rc_ack(struct qib_ibdev *dev, struct qib_qp *qp,
78 struct qib_other_headers *ohdr, u32 pmtu)
79 {
80 struct qib_ack_entry *e;
81 u32 hwords;
82 u32 len;
83 u32 bth0;
84 u32 bth2;
85
86 /* Don't send an ACK if we aren't supposed to. */
87 if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK))
88 goto bail;
89
90 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
91 hwords = 5;
92
93 switch (qp->s_ack_state) {
94 case OP(RDMA_READ_RESPONSE_LAST):
95 case OP(RDMA_READ_RESPONSE_ONLY):
96 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
97 if (e->rdma_sge.mr) {
98 atomic_dec(&e->rdma_sge.mr->refcount);
99 e->rdma_sge.mr = NULL;
100 }
101 /* FALLTHROUGH */
102 case OP(ATOMIC_ACKNOWLEDGE):
103 /*
104 * We can increment the tail pointer now that the last
105 * response has been sent instead of only being
106 * constructed.
107 */
108 if (++qp->s_tail_ack_queue > QIB_MAX_RDMA_ATOMIC)
109 qp->s_tail_ack_queue = 0;
110 /* FALLTHROUGH */
111 case OP(SEND_ONLY):
112 case OP(ACKNOWLEDGE):
113 /* Check for no next entry in the queue. */
114 if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
115 if (qp->s_flags & QIB_S_ACK_PENDING)
116 goto normal;
117 goto bail;
118 }
119
120 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
121 if (e->opcode == OP(RDMA_READ_REQUEST)) {
122 /*
123 * If a RDMA read response is being resent and
124 * we haven't seen the duplicate request yet,
125 * then stop sending the remaining responses the
126 * responder has seen until the requester resends it.
127 */
128 len = e->rdma_sge.sge_length;
129 if (len && !e->rdma_sge.mr) {
130 qp->s_tail_ack_queue = qp->r_head_ack_queue;
131 goto bail;
132 }
133 /* Copy SGE state in case we need to resend */
134 qp->s_rdma_mr = e->rdma_sge.mr;
135 if (qp->s_rdma_mr)
136 atomic_inc(&qp->s_rdma_mr->refcount);
137 qp->s_ack_rdma_sge.sge = e->rdma_sge;
138 qp->s_ack_rdma_sge.num_sge = 1;
139 qp->s_cur_sge = &qp->s_ack_rdma_sge;
140 if (len > pmtu) {
141 len = pmtu;
142 qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
143 } else {
144 qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
145 e->sent = 1;
146 }
147 ohdr->u.aeth = qib_compute_aeth(qp);
148 hwords++;
149 qp->s_ack_rdma_psn = e->psn;
150 bth2 = qp->s_ack_rdma_psn++ & QIB_PSN_MASK;
151 } else {
152 /* COMPARE_SWAP or FETCH_ADD */
153 qp->s_cur_sge = NULL;
154 len = 0;
155 qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
156 ohdr->u.at.aeth = qib_compute_aeth(qp);
157 ohdr->u.at.atomic_ack_eth[0] =
158 cpu_to_be32(e->atomic_data >> 32);
159 ohdr->u.at.atomic_ack_eth[1] =
160 cpu_to_be32(e->atomic_data);
161 hwords += sizeof(ohdr->u.at) / sizeof(u32);
162 bth2 = e->psn & QIB_PSN_MASK;
163 e->sent = 1;
164 }
165 bth0 = qp->s_ack_state << 24;
166 break;
167
168 case OP(RDMA_READ_RESPONSE_FIRST):
169 qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
170 /* FALLTHROUGH */
171 case OP(RDMA_READ_RESPONSE_MIDDLE):
172 qp->s_cur_sge = &qp->s_ack_rdma_sge;
173 qp->s_rdma_mr = qp->s_ack_rdma_sge.sge.mr;
174 if (qp->s_rdma_mr)
175 atomic_inc(&qp->s_rdma_mr->refcount);
176 len = qp->s_ack_rdma_sge.sge.sge_length;
177 if (len > pmtu)
178 len = pmtu;
179 else {
180 ohdr->u.aeth = qib_compute_aeth(qp);
181 hwords++;
182 qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
183 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
184 e->sent = 1;
185 }
186 bth0 = qp->s_ack_state << 24;
187 bth2 = qp->s_ack_rdma_psn++ & QIB_PSN_MASK;
188 break;
189
190 default:
191 normal:
192 /*
193 * Send a regular ACK.
194 * Set the s_ack_state so we wait until after sending
195 * the ACK before setting s_ack_state to ACKNOWLEDGE
196 * (see above).
197 */
198 qp->s_ack_state = OP(SEND_ONLY);
199 qp->s_flags &= ~QIB_S_ACK_PENDING;
200 qp->s_cur_sge = NULL;
201 if (qp->s_nak_state)
202 ohdr->u.aeth =
203 cpu_to_be32((qp->r_msn & QIB_MSN_MASK) |
204 (qp->s_nak_state <<
205 QIB_AETH_CREDIT_SHIFT));
206 else
207 ohdr->u.aeth = qib_compute_aeth(qp);
208 hwords++;
209 len = 0;
210 bth0 = OP(ACKNOWLEDGE) << 24;
211 bth2 = qp->s_ack_psn & QIB_PSN_MASK;
212 }
213 qp->s_rdma_ack_cnt++;
214 qp->s_hdrwords = hwords;
215 qp->s_cur_size = len;
216 qib_make_ruc_header(qp, ohdr, bth0, bth2);
217 return 1;
218
219 bail:
220 qp->s_ack_state = OP(ACKNOWLEDGE);
221 qp->s_flags &= ~(QIB_S_RESP_PENDING | QIB_S_ACK_PENDING);
222 return 0;
223 }
224
225 /**
226 * qib_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
227 * @qp: a pointer to the QP
228 *
229 * Return 1 if constructed; otherwise, return 0.
230 */
qib_make_rc_req(struct qib_qp * qp)231 int qib_make_rc_req(struct qib_qp *qp)
232 {
233 struct qib_ibdev *dev = to_idev(qp->ibqp.device);
234 struct qib_other_headers *ohdr;
235 struct qib_sge_state *ss;
236 struct qib_swqe *wqe;
237 u32 hwords;
238 u32 len;
239 u32 bth0;
240 u32 bth2;
241 u32 pmtu = qp->pmtu;
242 char newreq;
243 unsigned long flags;
244 int ret = 0;
245 int delta;
246
247 ohdr = &qp->s_hdr.u.oth;
248 if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
249 ohdr = &qp->s_hdr.u.l.oth;
250
251 /*
252 * The lock is needed to synchronize between the sending tasklet,
253 * the receive interrupt handler, and timeout resends.
254 */
255 spin_lock_irqsave(&qp->s_lock, flags);
256
257 /* Sending responses has higher priority over sending requests. */
258 if ((qp->s_flags & QIB_S_RESP_PENDING) &&
259 qib_make_rc_ack(dev, qp, ohdr, pmtu))
260 goto done;
261
262 if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_SEND_OK)) {
263 if (!(ib_qib_state_ops[qp->state] & QIB_FLUSH_SEND))
264 goto bail;
265 /* We are in the error state, flush the work request. */
266 if (qp->s_last == qp->s_head)
267 goto bail;
268 /* If DMAs are in progress, we can't flush immediately. */
269 if (atomic_read(&qp->s_dma_busy)) {
270 qp->s_flags |= QIB_S_WAIT_DMA;
271 goto bail;
272 }
273 wqe = get_swqe_ptr(qp, qp->s_last);
274 qib_send_complete(qp, wqe, qp->s_last != qp->s_acked ?
275 IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR);
276 /* will get called again */
277 goto done;
278 }
279
280 if (qp->s_flags & (QIB_S_WAIT_RNR | QIB_S_WAIT_ACK))
281 goto bail;
282
283 if (qib_cmp24(qp->s_psn, qp->s_sending_hpsn) <= 0) {
284 if (qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) {
285 qp->s_flags |= QIB_S_WAIT_PSN;
286 goto bail;
287 }
288 qp->s_sending_psn = qp->s_psn;
289 qp->s_sending_hpsn = qp->s_psn - 1;
290 }
291
292 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
293 hwords = 5;
294 bth0 = 0;
295
296 /* Send a request. */
297 wqe = get_swqe_ptr(qp, qp->s_cur);
298 switch (qp->s_state) {
299 default:
300 if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_NEXT_SEND_OK))
301 goto bail;
302 /*
303 * Resend an old request or start a new one.
304 *
305 * We keep track of the current SWQE so that
306 * we don't reset the "furthest progress" state
307 * if we need to back up.
308 */
309 newreq = 0;
310 if (qp->s_cur == qp->s_tail) {
311 /* Check if send work queue is empty. */
312 if (qp->s_tail == qp->s_head)
313 goto bail;
314 /*
315 * If a fence is requested, wait for previous
316 * RDMA read and atomic operations to finish.
317 */
318 if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
319 qp->s_num_rd_atomic) {
320 qp->s_flags |= QIB_S_WAIT_FENCE;
321 goto bail;
322 }
323 wqe->psn = qp->s_next_psn;
324 newreq = 1;
325 }
326 /*
327 * Note that we have to be careful not to modify the
328 * original work request since we may need to resend
329 * it.
330 */
331 len = wqe->length;
332 ss = &qp->s_sge;
333 bth2 = qp->s_psn & QIB_PSN_MASK;
334 switch (wqe->wr.opcode) {
335 case IB_WR_SEND:
336 case IB_WR_SEND_WITH_IMM:
337 /* If no credit, return. */
338 if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT) &&
339 qib_cmp24(wqe->ssn, qp->s_lsn + 1) > 0) {
340 qp->s_flags |= QIB_S_WAIT_SSN_CREDIT;
341 goto bail;
342 }
343 wqe->lpsn = wqe->psn;
344 if (len > pmtu) {
345 wqe->lpsn += (len - 1) / pmtu;
346 qp->s_state = OP(SEND_FIRST);
347 len = pmtu;
348 break;
349 }
350 if (wqe->wr.opcode == IB_WR_SEND)
351 qp->s_state = OP(SEND_ONLY);
352 else {
353 qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
354 /* Immediate data comes after the BTH */
355 ohdr->u.imm_data = wqe->wr.ex.imm_data;
356 hwords += 1;
357 }
358 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
359 bth0 |= IB_BTH_SOLICITED;
360 bth2 |= IB_BTH_REQ_ACK;
361 if (++qp->s_cur == qp->s_size)
362 qp->s_cur = 0;
363 break;
364
365 case IB_WR_RDMA_WRITE:
366 if (newreq && !(qp->s_flags & QIB_S_UNLIMITED_CREDIT))
367 qp->s_lsn++;
368 /* FALLTHROUGH */
369 case IB_WR_RDMA_WRITE_WITH_IMM:
370 /* If no credit, return. */
371 if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT) &&
372 qib_cmp24(wqe->ssn, qp->s_lsn + 1) > 0) {
373 qp->s_flags |= QIB_S_WAIT_SSN_CREDIT;
374 goto bail;
375 }
376 ohdr->u.rc.reth.vaddr =
377 cpu_to_be64(wqe->wr.wr.rdma.remote_addr);
378 ohdr->u.rc.reth.rkey =
379 cpu_to_be32(wqe->wr.wr.rdma.rkey);
380 ohdr->u.rc.reth.length = cpu_to_be32(len);
381 hwords += sizeof(struct ib_reth) / sizeof(u32);
382 wqe->lpsn = wqe->psn;
383 if (len > pmtu) {
384 wqe->lpsn += (len - 1) / pmtu;
385 qp->s_state = OP(RDMA_WRITE_FIRST);
386 len = pmtu;
387 break;
388 }
389 if (wqe->wr.opcode == IB_WR_RDMA_WRITE)
390 qp->s_state = OP(RDMA_WRITE_ONLY);
391 else {
392 qp->s_state =
393 OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
394 /* Immediate data comes after RETH */
395 ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
396 hwords += 1;
397 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
398 bth0 |= IB_BTH_SOLICITED;
399 }
400 bth2 |= IB_BTH_REQ_ACK;
401 if (++qp->s_cur == qp->s_size)
402 qp->s_cur = 0;
403 break;
404
405 case IB_WR_RDMA_READ:
406 /*
407 * Don't allow more operations to be started
408 * than the QP limits allow.
409 */
410 if (newreq) {
411 if (qp->s_num_rd_atomic >=
412 qp->s_max_rd_atomic) {
413 qp->s_flags |= QIB_S_WAIT_RDMAR;
414 goto bail;
415 }
416 qp->s_num_rd_atomic++;
417 if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT))
418 qp->s_lsn++;
419 /*
420 * Adjust s_next_psn to count the
421 * expected number of responses.
422 */
423 if (len > pmtu)
424 qp->s_next_psn += (len - 1) / pmtu;
425 wqe->lpsn = qp->s_next_psn++;
426 }
427 ohdr->u.rc.reth.vaddr =
428 cpu_to_be64(wqe->wr.wr.rdma.remote_addr);
429 ohdr->u.rc.reth.rkey =
430 cpu_to_be32(wqe->wr.wr.rdma.rkey);
431 ohdr->u.rc.reth.length = cpu_to_be32(len);
432 qp->s_state = OP(RDMA_READ_REQUEST);
433 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
434 ss = NULL;
435 len = 0;
436 bth2 |= IB_BTH_REQ_ACK;
437 if (++qp->s_cur == qp->s_size)
438 qp->s_cur = 0;
439 break;
440
441 case IB_WR_ATOMIC_CMP_AND_SWP:
442 case IB_WR_ATOMIC_FETCH_AND_ADD:
443 /*
444 * Don't allow more operations to be started
445 * than the QP limits allow.
446 */
447 if (newreq) {
448 if (qp->s_num_rd_atomic >=
449 qp->s_max_rd_atomic) {
450 qp->s_flags |= QIB_S_WAIT_RDMAR;
451 goto bail;
452 }
453 qp->s_num_rd_atomic++;
454 if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT))
455 qp->s_lsn++;
456 wqe->lpsn = wqe->psn;
457 }
458 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP) {
459 qp->s_state = OP(COMPARE_SWAP);
460 ohdr->u.atomic_eth.swap_data = cpu_to_be64(
461 wqe->wr.wr.atomic.swap);
462 ohdr->u.atomic_eth.compare_data = cpu_to_be64(
463 wqe->wr.wr.atomic.compare_add);
464 } else {
465 qp->s_state = OP(FETCH_ADD);
466 ohdr->u.atomic_eth.swap_data = cpu_to_be64(
467 wqe->wr.wr.atomic.compare_add);
468 ohdr->u.atomic_eth.compare_data = 0;
469 }
470 ohdr->u.atomic_eth.vaddr[0] = cpu_to_be32(
471 wqe->wr.wr.atomic.remote_addr >> 32);
472 ohdr->u.atomic_eth.vaddr[1] = cpu_to_be32(
473 wqe->wr.wr.atomic.remote_addr);
474 ohdr->u.atomic_eth.rkey = cpu_to_be32(
475 wqe->wr.wr.atomic.rkey);
476 hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
477 ss = NULL;
478 len = 0;
479 bth2 |= IB_BTH_REQ_ACK;
480 if (++qp->s_cur == qp->s_size)
481 qp->s_cur = 0;
482 break;
483
484 default:
485 goto bail;
486 }
487 qp->s_sge.sge = wqe->sg_list[0];
488 qp->s_sge.sg_list = wqe->sg_list + 1;
489 qp->s_sge.num_sge = wqe->wr.num_sge;
490 qp->s_sge.total_len = wqe->length;
491 qp->s_len = wqe->length;
492 if (newreq) {
493 qp->s_tail++;
494 if (qp->s_tail >= qp->s_size)
495 qp->s_tail = 0;
496 }
497 if (wqe->wr.opcode == IB_WR_RDMA_READ)
498 qp->s_psn = wqe->lpsn + 1;
499 else {
500 qp->s_psn++;
501 if (qib_cmp24(qp->s_psn, qp->s_next_psn) > 0)
502 qp->s_next_psn = qp->s_psn;
503 }
504 break;
505
506 case OP(RDMA_READ_RESPONSE_FIRST):
507 /*
508 * qp->s_state is normally set to the opcode of the
509 * last packet constructed for new requests and therefore
510 * is never set to RDMA read response.
511 * RDMA_READ_RESPONSE_FIRST is used by the ACK processing
512 * thread to indicate a SEND needs to be restarted from an
513 * earlier PSN without interferring with the sending thread.
514 * See qib_restart_rc().
515 */
516 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
517 /* FALLTHROUGH */
518 case OP(SEND_FIRST):
519 qp->s_state = OP(SEND_MIDDLE);
520 /* FALLTHROUGH */
521 case OP(SEND_MIDDLE):
522 bth2 = qp->s_psn++ & QIB_PSN_MASK;
523 if (qib_cmp24(qp->s_psn, qp->s_next_psn) > 0)
524 qp->s_next_psn = qp->s_psn;
525 ss = &qp->s_sge;
526 len = qp->s_len;
527 if (len > pmtu) {
528 len = pmtu;
529 break;
530 }
531 if (wqe->wr.opcode == IB_WR_SEND)
532 qp->s_state = OP(SEND_LAST);
533 else {
534 qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
535 /* Immediate data comes after the BTH */
536 ohdr->u.imm_data = wqe->wr.ex.imm_data;
537 hwords += 1;
538 }
539 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
540 bth0 |= IB_BTH_SOLICITED;
541 bth2 |= IB_BTH_REQ_ACK;
542 qp->s_cur++;
543 if (qp->s_cur >= qp->s_size)
544 qp->s_cur = 0;
545 break;
546
547 case OP(RDMA_READ_RESPONSE_LAST):
548 /*
549 * qp->s_state is normally set to the opcode of the
550 * last packet constructed for new requests and therefore
551 * is never set to RDMA read response.
552 * RDMA_READ_RESPONSE_LAST is used by the ACK processing
553 * thread to indicate a RDMA write needs to be restarted from
554 * an earlier PSN without interferring with the sending thread.
555 * See qib_restart_rc().
556 */
557 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
558 /* FALLTHROUGH */
559 case OP(RDMA_WRITE_FIRST):
560 qp->s_state = OP(RDMA_WRITE_MIDDLE);
561 /* FALLTHROUGH */
562 case OP(RDMA_WRITE_MIDDLE):
563 bth2 = qp->s_psn++ & QIB_PSN_MASK;
564 if (qib_cmp24(qp->s_psn, qp->s_next_psn) > 0)
565 qp->s_next_psn = qp->s_psn;
566 ss = &qp->s_sge;
567 len = qp->s_len;
568 if (len > pmtu) {
569 len = pmtu;
570 break;
571 }
572 if (wqe->wr.opcode == IB_WR_RDMA_WRITE)
573 qp->s_state = OP(RDMA_WRITE_LAST);
574 else {
575 qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
576 /* Immediate data comes after the BTH */
577 ohdr->u.imm_data = wqe->wr.ex.imm_data;
578 hwords += 1;
579 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
580 bth0 |= IB_BTH_SOLICITED;
581 }
582 bth2 |= IB_BTH_REQ_ACK;
583 qp->s_cur++;
584 if (qp->s_cur >= qp->s_size)
585 qp->s_cur = 0;
586 break;
587
588 case OP(RDMA_READ_RESPONSE_MIDDLE):
589 /*
590 * qp->s_state is normally set to the opcode of the
591 * last packet constructed for new requests and therefore
592 * is never set to RDMA read response.
593 * RDMA_READ_RESPONSE_MIDDLE is used by the ACK processing
594 * thread to indicate a RDMA read needs to be restarted from
595 * an earlier PSN without interferring with the sending thread.
596 * See qib_restart_rc().
597 */
598 len = ((qp->s_psn - wqe->psn) & QIB_PSN_MASK) * pmtu;
599 ohdr->u.rc.reth.vaddr =
600 cpu_to_be64(wqe->wr.wr.rdma.remote_addr + len);
601 ohdr->u.rc.reth.rkey =
602 cpu_to_be32(wqe->wr.wr.rdma.rkey);
603 ohdr->u.rc.reth.length = cpu_to_be32(wqe->length - len);
604 qp->s_state = OP(RDMA_READ_REQUEST);
605 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
606 bth2 = (qp->s_psn & QIB_PSN_MASK) | IB_BTH_REQ_ACK;
607 qp->s_psn = wqe->lpsn + 1;
608 ss = NULL;
609 len = 0;
610 qp->s_cur++;
611 if (qp->s_cur == qp->s_size)
612 qp->s_cur = 0;
613 break;
614 }
615 qp->s_sending_hpsn = bth2;
616 delta = (((int) bth2 - (int) wqe->psn) << 8) >> 8;
617 if (delta && delta % QIB_PSN_CREDIT == 0)
618 bth2 |= IB_BTH_REQ_ACK;
619 if (qp->s_flags & QIB_S_SEND_ONE) {
620 qp->s_flags &= ~QIB_S_SEND_ONE;
621 qp->s_flags |= QIB_S_WAIT_ACK;
622 bth2 |= IB_BTH_REQ_ACK;
623 }
624 qp->s_len -= len;
625 qp->s_hdrwords = hwords;
626 qp->s_cur_sge = ss;
627 qp->s_cur_size = len;
628 qib_make_ruc_header(qp, ohdr, bth0 | (qp->s_state << 24), bth2);
629 done:
630 ret = 1;
631 goto unlock;
632
633 bail:
634 qp->s_flags &= ~QIB_S_BUSY;
635 unlock:
636 spin_unlock_irqrestore(&qp->s_lock, flags);
637 return ret;
638 }
639
640 /**
641 * qib_send_rc_ack - Construct an ACK packet and send it
642 * @qp: a pointer to the QP
643 *
644 * This is called from qib_rc_rcv() and qib_kreceive().
645 * Note that RDMA reads and atomics are handled in the
646 * send side QP state and tasklet.
647 */
qib_send_rc_ack(struct qib_qp * qp)648 void qib_send_rc_ack(struct qib_qp *qp)
649 {
650 struct qib_devdata *dd = dd_from_ibdev(qp->ibqp.device);
651 struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
652 struct qib_pportdata *ppd = ppd_from_ibp(ibp);
653 u64 pbc;
654 u16 lrh0;
655 u32 bth0;
656 u32 hwords;
657 u32 pbufn;
658 u32 __iomem *piobuf;
659 struct qib_ib_header hdr;
660 struct qib_other_headers *ohdr;
661 u32 control;
662 unsigned long flags;
663
664 spin_lock_irqsave(&qp->s_lock, flags);
665
666 if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK))
667 goto unlock;
668
669 /* Don't send ACK or NAK if a RDMA read or atomic is pending. */
670 if ((qp->s_flags & QIB_S_RESP_PENDING) || qp->s_rdma_ack_cnt)
671 goto queue_ack;
672
673 /* Construct the header with s_lock held so APM doesn't change it. */
674 ohdr = &hdr.u.oth;
675 lrh0 = QIB_LRH_BTH;
676 /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4. */
677 hwords = 6;
678 if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
679 hwords += qib_make_grh(ibp, &hdr.u.l.grh,
680 &qp->remote_ah_attr.grh, hwords, 0);
681 ohdr = &hdr.u.l.oth;
682 lrh0 = QIB_LRH_GRH;
683 }
684 /* read pkey_index w/o lock (its atomic) */
685 bth0 = qib_get_pkey(ibp, qp->s_pkey_index) | (OP(ACKNOWLEDGE) << 24);
686 if (qp->s_mig_state == IB_MIG_MIGRATED)
687 bth0 |= IB_BTH_MIG_REQ;
688 if (qp->r_nak_state)
689 ohdr->u.aeth = cpu_to_be32((qp->r_msn & QIB_MSN_MASK) |
690 (qp->r_nak_state <<
691 QIB_AETH_CREDIT_SHIFT));
692 else
693 ohdr->u.aeth = qib_compute_aeth(qp);
694 lrh0 |= ibp->sl_to_vl[qp->remote_ah_attr.sl] << 12 |
695 qp->remote_ah_attr.sl << 4;
696 hdr.lrh[0] = cpu_to_be16(lrh0);
697 hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
698 hdr.lrh[2] = cpu_to_be16(hwords + SIZE_OF_CRC);
699 hdr.lrh[3] = cpu_to_be16(ppd->lid | qp->remote_ah_attr.src_path_bits);
700 ohdr->bth[0] = cpu_to_be32(bth0);
701 ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
702 ohdr->bth[2] = cpu_to_be32(qp->r_ack_psn & QIB_PSN_MASK);
703
704 spin_unlock_irqrestore(&qp->s_lock, flags);
705
706 /* Don't try to send ACKs if the link isn't ACTIVE */
707 if (!(ppd->lflags & QIBL_LINKACTIVE))
708 goto done;
709
710 control = dd->f_setpbc_control(ppd, hwords + SIZE_OF_CRC,
711 qp->s_srate, lrh0 >> 12);
712 /* length is + 1 for the control dword */
713 pbc = ((u64) control << 32) | (hwords + 1);
714
715 piobuf = dd->f_getsendbuf(ppd, pbc, &pbufn);
716 if (!piobuf) {
717 /*
718 * We are out of PIO buffers at the moment.
719 * Pass responsibility for sending the ACK to the
720 * send tasklet so that when a PIO buffer becomes
721 * available, the ACK is sent ahead of other outgoing
722 * packets.
723 */
724 spin_lock_irqsave(&qp->s_lock, flags);
725 goto queue_ack;
726 }
727
728 /*
729 * Write the pbc.
730 * We have to flush after the PBC for correctness
731 * on some cpus or WC buffer can be written out of order.
732 */
733 writeq(pbc, piobuf);
734
735 if (dd->flags & QIB_PIO_FLUSH_WC) {
736 u32 *hdrp = (u32 *) &hdr;
737
738 qib_flush_wc();
739 qib_pio_copy(piobuf + 2, hdrp, hwords - 1);
740 qib_flush_wc();
741 __raw_writel(hdrp[hwords - 1], piobuf + hwords + 1);
742 } else
743 qib_pio_copy(piobuf + 2, (u32 *) &hdr, hwords);
744
745 if (dd->flags & QIB_USE_SPCL_TRIG) {
746 u32 spcl_off = (pbufn >= dd->piobcnt2k) ? 2047 : 1023;
747
748 qib_flush_wc();
749 __raw_writel(0xaebecede, piobuf + spcl_off);
750 }
751
752 qib_flush_wc();
753 qib_sendbuf_done(dd, pbufn);
754
755 ibp->n_unicast_xmit++;
756 goto done;
757
758 queue_ack:
759 if (ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK) {
760 ibp->n_rc_qacks++;
761 qp->s_flags |= QIB_S_ACK_PENDING | QIB_S_RESP_PENDING;
762 qp->s_nak_state = qp->r_nak_state;
763 qp->s_ack_psn = qp->r_ack_psn;
764
765 /* Schedule the send tasklet. */
766 qib_schedule_send(qp);
767 }
768 unlock:
769 spin_unlock_irqrestore(&qp->s_lock, flags);
770 done:
771 return;
772 }
773
774 /**
775 * reset_psn - reset the QP state to send starting from PSN
776 * @qp: the QP
777 * @psn: the packet sequence number to restart at
778 *
779 * This is called from qib_rc_rcv() to process an incoming RC ACK
780 * for the given QP.
781 * Called at interrupt level with the QP s_lock held.
782 */
reset_psn(struct qib_qp * qp,u32 psn)783 static void reset_psn(struct qib_qp *qp, u32 psn)
784 {
785 u32 n = qp->s_acked;
786 struct qib_swqe *wqe = get_swqe_ptr(qp, n);
787 u32 opcode;
788
789 qp->s_cur = n;
790
791 /*
792 * If we are starting the request from the beginning,
793 * let the normal send code handle initialization.
794 */
795 if (qib_cmp24(psn, wqe->psn) <= 0) {
796 qp->s_state = OP(SEND_LAST);
797 goto done;
798 }
799
800 /* Find the work request opcode corresponding to the given PSN. */
801 opcode = wqe->wr.opcode;
802 for (;;) {
803 int diff;
804
805 if (++n == qp->s_size)
806 n = 0;
807 if (n == qp->s_tail)
808 break;
809 wqe = get_swqe_ptr(qp, n);
810 diff = qib_cmp24(psn, wqe->psn);
811 if (diff < 0)
812 break;
813 qp->s_cur = n;
814 /*
815 * If we are starting the request from the beginning,
816 * let the normal send code handle initialization.
817 */
818 if (diff == 0) {
819 qp->s_state = OP(SEND_LAST);
820 goto done;
821 }
822 opcode = wqe->wr.opcode;
823 }
824
825 /*
826 * Set the state to restart in the middle of a request.
827 * Don't change the s_sge, s_cur_sge, or s_cur_size.
828 * See qib_make_rc_req().
829 */
830 switch (opcode) {
831 case IB_WR_SEND:
832 case IB_WR_SEND_WITH_IMM:
833 qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
834 break;
835
836 case IB_WR_RDMA_WRITE:
837 case IB_WR_RDMA_WRITE_WITH_IMM:
838 qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
839 break;
840
841 case IB_WR_RDMA_READ:
842 qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
843 break;
844
845 default:
846 /*
847 * This case shouldn't happen since its only
848 * one PSN per req.
849 */
850 qp->s_state = OP(SEND_LAST);
851 }
852 done:
853 qp->s_psn = psn;
854 /*
855 * Set QIB_S_WAIT_PSN as qib_rc_complete() may start the timer
856 * asynchronously before the send tasklet can get scheduled.
857 * Doing it in qib_make_rc_req() is too late.
858 */
859 if ((qib_cmp24(qp->s_psn, qp->s_sending_hpsn) <= 0) &&
860 (qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) <= 0))
861 qp->s_flags |= QIB_S_WAIT_PSN;
862 }
863
864 /*
865 * Back up requester to resend the last un-ACKed request.
866 * The QP r_lock and s_lock should be held and interrupts disabled.
867 */
qib_restart_rc(struct qib_qp * qp,u32 psn,int wait)868 static void qib_restart_rc(struct qib_qp *qp, u32 psn, int wait)
869 {
870 struct qib_swqe *wqe = get_swqe_ptr(qp, qp->s_acked);
871 struct qib_ibport *ibp;
872
873 if (qp->s_retry == 0) {
874 if (qp->s_mig_state == IB_MIG_ARMED) {
875 qib_migrate_qp(qp);
876 qp->s_retry = qp->s_retry_cnt;
877 } else if (qp->s_last == qp->s_acked) {
878 qib_send_complete(qp, wqe, IB_WC_RETRY_EXC_ERR);
879 qib_error_qp(qp, IB_WC_WR_FLUSH_ERR);
880 return;
881 } else /* XXX need to handle delayed completion */
882 return;
883 } else
884 qp->s_retry--;
885
886 ibp = to_iport(qp->ibqp.device, qp->port_num);
887 if (wqe->wr.opcode == IB_WR_RDMA_READ)
888 ibp->n_rc_resends++;
889 else
890 ibp->n_rc_resends += (qp->s_psn - psn) & QIB_PSN_MASK;
891
892 qp->s_flags &= ~(QIB_S_WAIT_FENCE | QIB_S_WAIT_RDMAR |
893 QIB_S_WAIT_SSN_CREDIT | QIB_S_WAIT_PSN |
894 QIB_S_WAIT_ACK);
895 if (wait)
896 qp->s_flags |= QIB_S_SEND_ONE;
897 reset_psn(qp, psn);
898 }
899
900 /*
901 * This is called from s_timer for missing responses.
902 */
rc_timeout(unsigned long arg)903 static void rc_timeout(unsigned long arg)
904 {
905 struct qib_qp *qp = (struct qib_qp *)arg;
906 struct qib_ibport *ibp;
907 unsigned long flags;
908
909 spin_lock_irqsave(&qp->r_lock, flags);
910 spin_lock(&qp->s_lock);
911 if (qp->s_flags & QIB_S_TIMER) {
912 ibp = to_iport(qp->ibqp.device, qp->port_num);
913 ibp->n_rc_timeouts++;
914 qp->s_flags &= ~QIB_S_TIMER;
915 del_timer(&qp->s_timer);
916 qib_restart_rc(qp, qp->s_last_psn + 1, 1);
917 qib_schedule_send(qp);
918 }
919 spin_unlock(&qp->s_lock);
920 spin_unlock_irqrestore(&qp->r_lock, flags);
921 }
922
923 /*
924 * This is called from s_timer for RNR timeouts.
925 */
qib_rc_rnr_retry(unsigned long arg)926 void qib_rc_rnr_retry(unsigned long arg)
927 {
928 struct qib_qp *qp = (struct qib_qp *)arg;
929 unsigned long flags;
930
931 spin_lock_irqsave(&qp->s_lock, flags);
932 if (qp->s_flags & QIB_S_WAIT_RNR) {
933 qp->s_flags &= ~QIB_S_WAIT_RNR;
934 del_timer(&qp->s_timer);
935 qib_schedule_send(qp);
936 }
937 spin_unlock_irqrestore(&qp->s_lock, flags);
938 }
939
940 /*
941 * Set qp->s_sending_psn to the next PSN after the given one.
942 * This would be psn+1 except when RDMA reads are present.
943 */
reset_sending_psn(struct qib_qp * qp,u32 psn)944 static void reset_sending_psn(struct qib_qp *qp, u32 psn)
945 {
946 struct qib_swqe *wqe;
947 u32 n = qp->s_last;
948
949 /* Find the work request corresponding to the given PSN. */
950 for (;;) {
951 wqe = get_swqe_ptr(qp, n);
952 if (qib_cmp24(psn, wqe->lpsn) <= 0) {
953 if (wqe->wr.opcode == IB_WR_RDMA_READ)
954 qp->s_sending_psn = wqe->lpsn + 1;
955 else
956 qp->s_sending_psn = psn + 1;
957 break;
958 }
959 if (++n == qp->s_size)
960 n = 0;
961 if (n == qp->s_tail)
962 break;
963 }
964 }
965
966 /*
967 * This should be called with the QP s_lock held and interrupts disabled.
968 */
qib_rc_send_complete(struct qib_qp * qp,struct qib_ib_header * hdr)969 void qib_rc_send_complete(struct qib_qp *qp, struct qib_ib_header *hdr)
970 {
971 struct qib_other_headers *ohdr;
972 struct qib_swqe *wqe;
973 struct ib_wc wc;
974 unsigned i;
975 u32 opcode;
976 u32 psn;
977
978 if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_OR_FLUSH_SEND))
979 return;
980
981 /* Find out where the BTH is */
982 if ((be16_to_cpu(hdr->lrh[0]) & 3) == QIB_LRH_BTH)
983 ohdr = &hdr->u.oth;
984 else
985 ohdr = &hdr->u.l.oth;
986
987 opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
988 if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
989 opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
990 WARN_ON(!qp->s_rdma_ack_cnt);
991 qp->s_rdma_ack_cnt--;
992 return;
993 }
994
995 psn = be32_to_cpu(ohdr->bth[2]);
996 reset_sending_psn(qp, psn);
997
998 /*
999 * Start timer after a packet requesting an ACK has been sent and
1000 * there are still requests that haven't been acked.
1001 */
1002 if ((psn & IB_BTH_REQ_ACK) && qp->s_acked != qp->s_tail &&
1003 !(qp->s_flags & (QIB_S_TIMER | QIB_S_WAIT_RNR | QIB_S_WAIT_PSN)) &&
1004 (ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK))
1005 start_timer(qp);
1006
1007 while (qp->s_last != qp->s_acked) {
1008 wqe = get_swqe_ptr(qp, qp->s_last);
1009 if (qib_cmp24(wqe->lpsn, qp->s_sending_psn) >= 0 &&
1010 qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)
1011 break;
1012 for (i = 0; i < wqe->wr.num_sge; i++) {
1013 struct qib_sge *sge = &wqe->sg_list[i];
1014
1015 atomic_dec(&sge->mr->refcount);
1016 }
1017 /* Post a send completion queue entry if requested. */
1018 if (!(qp->s_flags & QIB_S_SIGNAL_REQ_WR) ||
1019 (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
1020 memset(&wc, 0, sizeof wc);
1021 wc.wr_id = wqe->wr.wr_id;
1022 wc.status = IB_WC_SUCCESS;
1023 wc.opcode = ib_qib_wc_opcode[wqe->wr.opcode];
1024 wc.byte_len = wqe->length;
1025 wc.qp = &qp->ibqp;
1026 qib_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 0);
1027 }
1028 if (++qp->s_last >= qp->s_size)
1029 qp->s_last = 0;
1030 }
1031 /*
1032 * If we were waiting for sends to complete before resending,
1033 * and they are now complete, restart sending.
1034 */
1035 if (qp->s_flags & QIB_S_WAIT_PSN &&
1036 qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1037 qp->s_flags &= ~QIB_S_WAIT_PSN;
1038 qp->s_sending_psn = qp->s_psn;
1039 qp->s_sending_hpsn = qp->s_psn - 1;
1040 qib_schedule_send(qp);
1041 }
1042 }
1043
update_last_psn(struct qib_qp * qp,u32 psn)1044 static inline void update_last_psn(struct qib_qp *qp, u32 psn)
1045 {
1046 qp->s_last_psn = psn;
1047 }
1048
1049 /*
1050 * Generate a SWQE completion.
1051 * This is similar to qib_send_complete but has to check to be sure
1052 * that the SGEs are not being referenced if the SWQE is being resent.
1053 */
do_rc_completion(struct qib_qp * qp,struct qib_swqe * wqe,struct qib_ibport * ibp)1054 static struct qib_swqe *do_rc_completion(struct qib_qp *qp,
1055 struct qib_swqe *wqe,
1056 struct qib_ibport *ibp)
1057 {
1058 struct ib_wc wc;
1059 unsigned i;
1060
1061 /*
1062 * Don't decrement refcount and don't generate a
1063 * completion if the SWQE is being resent until the send
1064 * is finished.
1065 */
1066 if (qib_cmp24(wqe->lpsn, qp->s_sending_psn) < 0 ||
1067 qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
1068 for (i = 0; i < wqe->wr.num_sge; i++) {
1069 struct qib_sge *sge = &wqe->sg_list[i];
1070
1071 atomic_dec(&sge->mr->refcount);
1072 }
1073 /* Post a send completion queue entry if requested. */
1074 if (!(qp->s_flags & QIB_S_SIGNAL_REQ_WR) ||
1075 (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
1076 memset(&wc, 0, sizeof wc);
1077 wc.wr_id = wqe->wr.wr_id;
1078 wc.status = IB_WC_SUCCESS;
1079 wc.opcode = ib_qib_wc_opcode[wqe->wr.opcode];
1080 wc.byte_len = wqe->length;
1081 wc.qp = &qp->ibqp;
1082 qib_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 0);
1083 }
1084 if (++qp->s_last >= qp->s_size)
1085 qp->s_last = 0;
1086 } else
1087 ibp->n_rc_delayed_comp++;
1088
1089 qp->s_retry = qp->s_retry_cnt;
1090 update_last_psn(qp, wqe->lpsn);
1091
1092 /*
1093 * If we are completing a request which is in the process of
1094 * being resent, we can stop resending it since we know the
1095 * responder has already seen it.
1096 */
1097 if (qp->s_acked == qp->s_cur) {
1098 if (++qp->s_cur >= qp->s_size)
1099 qp->s_cur = 0;
1100 qp->s_acked = qp->s_cur;
1101 wqe = get_swqe_ptr(qp, qp->s_cur);
1102 if (qp->s_acked != qp->s_tail) {
1103 qp->s_state = OP(SEND_LAST);
1104 qp->s_psn = wqe->psn;
1105 }
1106 } else {
1107 if (++qp->s_acked >= qp->s_size)
1108 qp->s_acked = 0;
1109 if (qp->state == IB_QPS_SQD && qp->s_acked == qp->s_cur)
1110 qp->s_draining = 0;
1111 wqe = get_swqe_ptr(qp, qp->s_acked);
1112 }
1113 return wqe;
1114 }
1115
1116 /**
1117 * do_rc_ack - process an incoming RC ACK
1118 * @qp: the QP the ACK came in on
1119 * @psn: the packet sequence number of the ACK
1120 * @opcode: the opcode of the request that resulted in the ACK
1121 *
1122 * This is called from qib_rc_rcv_resp() to process an incoming RC ACK
1123 * for the given QP.
1124 * Called at interrupt level with the QP s_lock held.
1125 * Returns 1 if OK, 0 if current operation should be aborted (NAK).
1126 */
do_rc_ack(struct qib_qp * qp,u32 aeth,u32 psn,int opcode,u64 val,struct qib_ctxtdata * rcd)1127 static int do_rc_ack(struct qib_qp *qp, u32 aeth, u32 psn, int opcode,
1128 u64 val, struct qib_ctxtdata *rcd)
1129 {
1130 struct qib_ibport *ibp;
1131 enum ib_wc_status status;
1132 struct qib_swqe *wqe;
1133 int ret = 0;
1134 u32 ack_psn;
1135 int diff;
1136
1137 /* Remove QP from retry timer */
1138 if (qp->s_flags & (QIB_S_TIMER | QIB_S_WAIT_RNR)) {
1139 qp->s_flags &= ~(QIB_S_TIMER | QIB_S_WAIT_RNR);
1140 del_timer(&qp->s_timer);
1141 }
1142
1143 /*
1144 * Note that NAKs implicitly ACK outstanding SEND and RDMA write
1145 * requests and implicitly NAK RDMA read and atomic requests issued
1146 * before the NAK'ed request. The MSN won't include the NAK'ed
1147 * request but will include an ACK'ed request(s).
1148 */
1149 ack_psn = psn;
1150 if (aeth >> 29)
1151 ack_psn--;
1152 wqe = get_swqe_ptr(qp, qp->s_acked);
1153 ibp = to_iport(qp->ibqp.device, qp->port_num);
1154
1155 /*
1156 * The MSN might be for a later WQE than the PSN indicates so
1157 * only complete WQEs that the PSN finishes.
1158 */
1159 while ((diff = qib_cmp24(ack_psn, wqe->lpsn)) >= 0) {
1160 /*
1161 * RDMA_READ_RESPONSE_ONLY is a special case since
1162 * we want to generate completion events for everything
1163 * before the RDMA read, copy the data, then generate
1164 * the completion for the read.
1165 */
1166 if (wqe->wr.opcode == IB_WR_RDMA_READ &&
1167 opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
1168 diff == 0) {
1169 ret = 1;
1170 goto bail;
1171 }
1172 /*
1173 * If this request is a RDMA read or atomic, and the ACK is
1174 * for a later operation, this ACK NAKs the RDMA read or
1175 * atomic. In other words, only a RDMA_READ_LAST or ONLY
1176 * can ACK a RDMA read and likewise for atomic ops. Note
1177 * that the NAK case can only happen if relaxed ordering is
1178 * used and requests are sent after an RDMA read or atomic
1179 * is sent but before the response is received.
1180 */
1181 if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
1182 (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
1183 ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1184 wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
1185 (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0))) {
1186 /* Retry this request. */
1187 if (!(qp->r_flags & QIB_R_RDMAR_SEQ)) {
1188 qp->r_flags |= QIB_R_RDMAR_SEQ;
1189 qib_restart_rc(qp, qp->s_last_psn + 1, 0);
1190 if (list_empty(&qp->rspwait)) {
1191 qp->r_flags |= QIB_R_RSP_SEND;
1192 atomic_inc(&qp->refcount);
1193 list_add_tail(&qp->rspwait,
1194 &rcd->qp_wait_list);
1195 }
1196 }
1197 /*
1198 * No need to process the ACK/NAK since we are
1199 * restarting an earlier request.
1200 */
1201 goto bail;
1202 }
1203 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1204 wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
1205 u64 *vaddr = wqe->sg_list[0].vaddr;
1206 *vaddr = val;
1207 }
1208 if (qp->s_num_rd_atomic &&
1209 (wqe->wr.opcode == IB_WR_RDMA_READ ||
1210 wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1211 wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
1212 qp->s_num_rd_atomic--;
1213 /* Restart sending task if fence is complete */
1214 if ((qp->s_flags & QIB_S_WAIT_FENCE) &&
1215 !qp->s_num_rd_atomic) {
1216 qp->s_flags &= ~(QIB_S_WAIT_FENCE |
1217 QIB_S_WAIT_ACK);
1218 qib_schedule_send(qp);
1219 } else if (qp->s_flags & QIB_S_WAIT_RDMAR) {
1220 qp->s_flags &= ~(QIB_S_WAIT_RDMAR |
1221 QIB_S_WAIT_ACK);
1222 qib_schedule_send(qp);
1223 }
1224 }
1225 wqe = do_rc_completion(qp, wqe, ibp);
1226 if (qp->s_acked == qp->s_tail)
1227 break;
1228 }
1229
1230 switch (aeth >> 29) {
1231 case 0: /* ACK */
1232 ibp->n_rc_acks++;
1233 if (qp->s_acked != qp->s_tail) {
1234 /*
1235 * We are expecting more ACKs so
1236 * reset the retransmit timer.
1237 */
1238 start_timer(qp);
1239 /*
1240 * We can stop resending the earlier packets and
1241 * continue with the next packet the receiver wants.
1242 */
1243 if (qib_cmp24(qp->s_psn, psn) <= 0)
1244 reset_psn(qp, psn + 1);
1245 } else if (qib_cmp24(qp->s_psn, psn) <= 0) {
1246 qp->s_state = OP(SEND_LAST);
1247 qp->s_psn = psn + 1;
1248 }
1249 if (qp->s_flags & QIB_S_WAIT_ACK) {
1250 qp->s_flags &= ~QIB_S_WAIT_ACK;
1251 qib_schedule_send(qp);
1252 }
1253 qib_get_credit(qp, aeth);
1254 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1255 qp->s_retry = qp->s_retry_cnt;
1256 update_last_psn(qp, psn);
1257 ret = 1;
1258 goto bail;
1259
1260 case 1: /* RNR NAK */
1261 ibp->n_rnr_naks++;
1262 if (qp->s_acked == qp->s_tail)
1263 goto bail;
1264 if (qp->s_flags & QIB_S_WAIT_RNR)
1265 goto bail;
1266 if (qp->s_rnr_retry == 0) {
1267 status = IB_WC_RNR_RETRY_EXC_ERR;
1268 goto class_b;
1269 }
1270 if (qp->s_rnr_retry_cnt < 7)
1271 qp->s_rnr_retry--;
1272
1273 /* The last valid PSN is the previous PSN. */
1274 update_last_psn(qp, psn - 1);
1275
1276 ibp->n_rc_resends += (qp->s_psn - psn) & QIB_PSN_MASK;
1277
1278 reset_psn(qp, psn);
1279
1280 qp->s_flags &= ~(QIB_S_WAIT_SSN_CREDIT | QIB_S_WAIT_ACK);
1281 qp->s_flags |= QIB_S_WAIT_RNR;
1282 qp->s_timer.function = qib_rc_rnr_retry;
1283 qp->s_timer.expires = jiffies + usecs_to_jiffies(
1284 ib_qib_rnr_table[(aeth >> QIB_AETH_CREDIT_SHIFT) &
1285 QIB_AETH_CREDIT_MASK]);
1286 add_timer(&qp->s_timer);
1287 goto bail;
1288
1289 case 3: /* NAK */
1290 if (qp->s_acked == qp->s_tail)
1291 goto bail;
1292 /* The last valid PSN is the previous PSN. */
1293 update_last_psn(qp, psn - 1);
1294 switch ((aeth >> QIB_AETH_CREDIT_SHIFT) &
1295 QIB_AETH_CREDIT_MASK) {
1296 case 0: /* PSN sequence error */
1297 ibp->n_seq_naks++;
1298 /*
1299 * Back up to the responder's expected PSN.
1300 * Note that we might get a NAK in the middle of an
1301 * RDMA READ response which terminates the RDMA
1302 * READ.
1303 */
1304 qib_restart_rc(qp, psn, 0);
1305 qib_schedule_send(qp);
1306 break;
1307
1308 case 1: /* Invalid Request */
1309 status = IB_WC_REM_INV_REQ_ERR;
1310 ibp->n_other_naks++;
1311 goto class_b;
1312
1313 case 2: /* Remote Access Error */
1314 status = IB_WC_REM_ACCESS_ERR;
1315 ibp->n_other_naks++;
1316 goto class_b;
1317
1318 case 3: /* Remote Operation Error */
1319 status = IB_WC_REM_OP_ERR;
1320 ibp->n_other_naks++;
1321 class_b:
1322 if (qp->s_last == qp->s_acked) {
1323 qib_send_complete(qp, wqe, status);
1324 qib_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1325 }
1326 break;
1327
1328 default:
1329 /* Ignore other reserved NAK error codes */
1330 goto reserved;
1331 }
1332 qp->s_retry = qp->s_retry_cnt;
1333 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1334 goto bail;
1335
1336 default: /* 2: reserved */
1337 reserved:
1338 /* Ignore reserved NAK codes. */
1339 goto bail;
1340 }
1341
1342 bail:
1343 return ret;
1344 }
1345
1346 /*
1347 * We have seen an out of sequence RDMA read middle or last packet.
1348 * This ACKs SENDs and RDMA writes up to the first RDMA read or atomic SWQE.
1349 */
rdma_seq_err(struct qib_qp * qp,struct qib_ibport * ibp,u32 psn,struct qib_ctxtdata * rcd)1350 static void rdma_seq_err(struct qib_qp *qp, struct qib_ibport *ibp, u32 psn,
1351 struct qib_ctxtdata *rcd)
1352 {
1353 struct qib_swqe *wqe;
1354
1355 /* Remove QP from retry timer */
1356 if (qp->s_flags & (QIB_S_TIMER | QIB_S_WAIT_RNR)) {
1357 qp->s_flags &= ~(QIB_S_TIMER | QIB_S_WAIT_RNR);
1358 del_timer(&qp->s_timer);
1359 }
1360
1361 wqe = get_swqe_ptr(qp, qp->s_acked);
1362
1363 while (qib_cmp24(psn, wqe->lpsn) > 0) {
1364 if (wqe->wr.opcode == IB_WR_RDMA_READ ||
1365 wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
1366 wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
1367 break;
1368 wqe = do_rc_completion(qp, wqe, ibp);
1369 }
1370
1371 ibp->n_rdma_seq++;
1372 qp->r_flags |= QIB_R_RDMAR_SEQ;
1373 qib_restart_rc(qp, qp->s_last_psn + 1, 0);
1374 if (list_empty(&qp->rspwait)) {
1375 qp->r_flags |= QIB_R_RSP_SEND;
1376 atomic_inc(&qp->refcount);
1377 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1378 }
1379 }
1380
1381 /**
1382 * qib_rc_rcv_resp - process an incoming RC response packet
1383 * @ibp: the port this packet came in on
1384 * @ohdr: the other headers for this packet
1385 * @data: the packet data
1386 * @tlen: the packet length
1387 * @qp: the QP for this packet
1388 * @opcode: the opcode for this packet
1389 * @psn: the packet sequence number for this packet
1390 * @hdrsize: the header length
1391 * @pmtu: the path MTU
1392 *
1393 * This is called from qib_rc_rcv() to process an incoming RC response
1394 * packet for the given QP.
1395 * Called at interrupt level.
1396 */
qib_rc_rcv_resp(struct qib_ibport * ibp,struct qib_other_headers * ohdr,void * data,u32 tlen,struct qib_qp * qp,u32 opcode,u32 psn,u32 hdrsize,u32 pmtu,struct qib_ctxtdata * rcd)1397 static void qib_rc_rcv_resp(struct qib_ibport *ibp,
1398 struct qib_other_headers *ohdr,
1399 void *data, u32 tlen,
1400 struct qib_qp *qp,
1401 u32 opcode,
1402 u32 psn, u32 hdrsize, u32 pmtu,
1403 struct qib_ctxtdata *rcd)
1404 {
1405 struct qib_swqe *wqe;
1406 struct qib_pportdata *ppd = ppd_from_ibp(ibp);
1407 enum ib_wc_status status;
1408 unsigned long flags;
1409 int diff;
1410 u32 pad;
1411 u32 aeth;
1412 u64 val;
1413
1414 if (opcode != OP(RDMA_READ_RESPONSE_MIDDLE)) {
1415 /*
1416 * If ACK'd PSN on SDMA busy list try to make progress to
1417 * reclaim SDMA credits.
1418 */
1419 if ((qib_cmp24(psn, qp->s_sending_psn) >= 0) &&
1420 (qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)) {
1421
1422 /*
1423 * If send tasklet not running attempt to progress
1424 * SDMA queue.
1425 */
1426 if (!(qp->s_flags & QIB_S_BUSY)) {
1427 /* Acquire SDMA Lock */
1428 spin_lock_irqsave(&ppd->sdma_lock, flags);
1429 /* Invoke sdma make progress */
1430 qib_sdma_make_progress(ppd);
1431 /* Release SDMA Lock */
1432 spin_unlock_irqrestore(&ppd->sdma_lock, flags);
1433 }
1434 }
1435 }
1436
1437 spin_lock_irqsave(&qp->s_lock, flags);
1438 if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK))
1439 goto ack_done;
1440
1441 /* Ignore invalid responses. */
1442 if (qib_cmp24(psn, qp->s_next_psn) >= 0)
1443 goto ack_done;
1444
1445 /* Ignore duplicate responses. */
1446 diff = qib_cmp24(psn, qp->s_last_psn);
1447 if (unlikely(diff <= 0)) {
1448 /* Update credits for "ghost" ACKs */
1449 if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
1450 aeth = be32_to_cpu(ohdr->u.aeth);
1451 if ((aeth >> 29) == 0)
1452 qib_get_credit(qp, aeth);
1453 }
1454 goto ack_done;
1455 }
1456
1457 /*
1458 * Skip everything other than the PSN we expect, if we are waiting
1459 * for a reply to a restarted RDMA read or atomic op.
1460 */
1461 if (qp->r_flags & QIB_R_RDMAR_SEQ) {
1462 if (qib_cmp24(psn, qp->s_last_psn + 1) != 0)
1463 goto ack_done;
1464 qp->r_flags &= ~QIB_R_RDMAR_SEQ;
1465 }
1466
1467 if (unlikely(qp->s_acked == qp->s_tail))
1468 goto ack_done;
1469 wqe = get_swqe_ptr(qp, qp->s_acked);
1470 status = IB_WC_SUCCESS;
1471
1472 switch (opcode) {
1473 case OP(ACKNOWLEDGE):
1474 case OP(ATOMIC_ACKNOWLEDGE):
1475 case OP(RDMA_READ_RESPONSE_FIRST):
1476 aeth = be32_to_cpu(ohdr->u.aeth);
1477 if (opcode == OP(ATOMIC_ACKNOWLEDGE)) {
1478 __be32 *p = ohdr->u.at.atomic_ack_eth;
1479
1480 val = ((u64) be32_to_cpu(p[0]) << 32) |
1481 be32_to_cpu(p[1]);
1482 } else
1483 val = 0;
1484 if (!do_rc_ack(qp, aeth, psn, opcode, val, rcd) ||
1485 opcode != OP(RDMA_READ_RESPONSE_FIRST))
1486 goto ack_done;
1487 hdrsize += 4;
1488 wqe = get_swqe_ptr(qp, qp->s_acked);
1489 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1490 goto ack_op_err;
1491 /*
1492 * If this is a response to a resent RDMA read, we
1493 * have to be careful to copy the data to the right
1494 * location.
1495 */
1496 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1497 wqe, psn, pmtu);
1498 goto read_middle;
1499
1500 case OP(RDMA_READ_RESPONSE_MIDDLE):
1501 /* no AETH, no ACK */
1502 if (unlikely(qib_cmp24(psn, qp->s_last_psn + 1)))
1503 goto ack_seq_err;
1504 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1505 goto ack_op_err;
1506 read_middle:
1507 if (unlikely(tlen != (hdrsize + pmtu + 4)))
1508 goto ack_len_err;
1509 if (unlikely(pmtu >= qp->s_rdma_read_len))
1510 goto ack_len_err;
1511
1512 /*
1513 * We got a response so update the timeout.
1514 * 4.096 usec. * (1 << qp->timeout)
1515 */
1516 qp->s_flags |= QIB_S_TIMER;
1517 mod_timer(&qp->s_timer, jiffies + qp->timeout_jiffies);
1518 if (qp->s_flags & QIB_S_WAIT_ACK) {
1519 qp->s_flags &= ~QIB_S_WAIT_ACK;
1520 qib_schedule_send(qp);
1521 }
1522
1523 if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
1524 qp->s_retry = qp->s_retry_cnt;
1525
1526 /*
1527 * Update the RDMA receive state but do the copy w/o
1528 * holding the locks and blocking interrupts.
1529 */
1530 qp->s_rdma_read_len -= pmtu;
1531 update_last_psn(qp, psn);
1532 spin_unlock_irqrestore(&qp->s_lock, flags);
1533 qib_copy_sge(&qp->s_rdma_read_sge, data, pmtu, 0);
1534 goto bail;
1535
1536 case OP(RDMA_READ_RESPONSE_ONLY):
1537 aeth = be32_to_cpu(ohdr->u.aeth);
1538 if (!do_rc_ack(qp, aeth, psn, opcode, 0, rcd))
1539 goto ack_done;
1540 /* Get the number of bytes the message was padded by. */
1541 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1542 /*
1543 * Check that the data size is >= 0 && <= pmtu.
1544 * Remember to account for the AETH header (4) and
1545 * ICRC (4).
1546 */
1547 if (unlikely(tlen < (hdrsize + pad + 8)))
1548 goto ack_len_err;
1549 /*
1550 * If this is a response to a resent RDMA read, we
1551 * have to be careful to copy the data to the right
1552 * location.
1553 */
1554 wqe = get_swqe_ptr(qp, qp->s_acked);
1555 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1556 wqe, psn, pmtu);
1557 goto read_last;
1558
1559 case OP(RDMA_READ_RESPONSE_LAST):
1560 /* ACKs READ req. */
1561 if (unlikely(qib_cmp24(psn, qp->s_last_psn + 1)))
1562 goto ack_seq_err;
1563 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1564 goto ack_op_err;
1565 /* Get the number of bytes the message was padded by. */
1566 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1567 /*
1568 * Check that the data size is >= 1 && <= pmtu.
1569 * Remember to account for the AETH header (4) and
1570 * ICRC (4).
1571 */
1572 if (unlikely(tlen <= (hdrsize + pad + 8)))
1573 goto ack_len_err;
1574 read_last:
1575 tlen -= hdrsize + pad + 8;
1576 if (unlikely(tlen != qp->s_rdma_read_len))
1577 goto ack_len_err;
1578 aeth = be32_to_cpu(ohdr->u.aeth);
1579 qib_copy_sge(&qp->s_rdma_read_sge, data, tlen, 0);
1580 WARN_ON(qp->s_rdma_read_sge.num_sge);
1581 (void) do_rc_ack(qp, aeth, psn,
1582 OP(RDMA_READ_RESPONSE_LAST), 0, rcd);
1583 goto ack_done;
1584 }
1585
1586 ack_op_err:
1587 status = IB_WC_LOC_QP_OP_ERR;
1588 goto ack_err;
1589
1590 ack_seq_err:
1591 rdma_seq_err(qp, ibp, psn, rcd);
1592 goto ack_done;
1593
1594 ack_len_err:
1595 status = IB_WC_LOC_LEN_ERR;
1596 ack_err:
1597 if (qp->s_last == qp->s_acked) {
1598 qib_send_complete(qp, wqe, status);
1599 qib_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1600 }
1601 ack_done:
1602 spin_unlock_irqrestore(&qp->s_lock, flags);
1603 bail:
1604 return;
1605 }
1606
1607 /**
1608 * qib_rc_rcv_error - process an incoming duplicate or error RC packet
1609 * @ohdr: the other headers for this packet
1610 * @data: the packet data
1611 * @qp: the QP for this packet
1612 * @opcode: the opcode for this packet
1613 * @psn: the packet sequence number for this packet
1614 * @diff: the difference between the PSN and the expected PSN
1615 *
1616 * This is called from qib_rc_rcv() to process an unexpected
1617 * incoming RC packet for the given QP.
1618 * Called at interrupt level.
1619 * Return 1 if no more processing is needed; otherwise return 0 to
1620 * schedule a response to be sent.
1621 */
qib_rc_rcv_error(struct qib_other_headers * ohdr,void * data,struct qib_qp * qp,u32 opcode,u32 psn,int diff,struct qib_ctxtdata * rcd)1622 static int qib_rc_rcv_error(struct qib_other_headers *ohdr,
1623 void *data,
1624 struct qib_qp *qp,
1625 u32 opcode,
1626 u32 psn,
1627 int diff,
1628 struct qib_ctxtdata *rcd)
1629 {
1630 struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
1631 struct qib_ack_entry *e;
1632 unsigned long flags;
1633 u8 i, prev;
1634 int old_req;
1635
1636 if (diff > 0) {
1637 /*
1638 * Packet sequence error.
1639 * A NAK will ACK earlier sends and RDMA writes.
1640 * Don't queue the NAK if we already sent one.
1641 */
1642 if (!qp->r_nak_state) {
1643 ibp->n_rc_seqnak++;
1644 qp->r_nak_state = IB_NAK_PSN_ERROR;
1645 /* Use the expected PSN. */
1646 qp->r_ack_psn = qp->r_psn;
1647 /*
1648 * Wait to send the sequence NAK until all packets
1649 * in the receive queue have been processed.
1650 * Otherwise, we end up propagating congestion.
1651 */
1652 if (list_empty(&qp->rspwait)) {
1653 qp->r_flags |= QIB_R_RSP_NAK;
1654 atomic_inc(&qp->refcount);
1655 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
1656 }
1657 }
1658 goto done;
1659 }
1660
1661 /*
1662 * Handle a duplicate request. Don't re-execute SEND, RDMA
1663 * write or atomic op. Don't NAK errors, just silently drop
1664 * the duplicate request. Note that r_sge, r_len, and
1665 * r_rcv_len may be in use so don't modify them.
1666 *
1667 * We are supposed to ACK the earliest duplicate PSN but we
1668 * can coalesce an outstanding duplicate ACK. We have to
1669 * send the earliest so that RDMA reads can be restarted at
1670 * the requester's expected PSN.
1671 *
1672 * First, find where this duplicate PSN falls within the
1673 * ACKs previously sent.
1674 * old_req is true if there is an older response that is scheduled
1675 * to be sent before sending this one.
1676 */
1677 e = NULL;
1678 old_req = 1;
1679 ibp->n_rc_dupreq++;
1680
1681 spin_lock_irqsave(&qp->s_lock, flags);
1682
1683 for (i = qp->r_head_ack_queue; ; i = prev) {
1684 if (i == qp->s_tail_ack_queue)
1685 old_req = 0;
1686 if (i)
1687 prev = i - 1;
1688 else
1689 prev = QIB_MAX_RDMA_ATOMIC;
1690 if (prev == qp->r_head_ack_queue) {
1691 e = NULL;
1692 break;
1693 }
1694 e = &qp->s_ack_queue[prev];
1695 if (!e->opcode) {
1696 e = NULL;
1697 break;
1698 }
1699 if (qib_cmp24(psn, e->psn) >= 0) {
1700 if (prev == qp->s_tail_ack_queue &&
1701 qib_cmp24(psn, e->lpsn) <= 0)
1702 old_req = 0;
1703 break;
1704 }
1705 }
1706 switch (opcode) {
1707 case OP(RDMA_READ_REQUEST): {
1708 struct ib_reth *reth;
1709 u32 offset;
1710 u32 len;
1711
1712 /*
1713 * If we didn't find the RDMA read request in the ack queue,
1714 * we can ignore this request.
1715 */
1716 if (!e || e->opcode != OP(RDMA_READ_REQUEST))
1717 goto unlock_done;
1718 /* RETH comes after BTH */
1719 reth = &ohdr->u.rc.reth;
1720 /*
1721 * Address range must be a subset of the original
1722 * request and start on pmtu boundaries.
1723 * We reuse the old ack_queue slot since the requester
1724 * should not back up and request an earlier PSN for the
1725 * same request.
1726 */
1727 offset = ((psn - e->psn) & QIB_PSN_MASK) *
1728 qp->pmtu;
1729 len = be32_to_cpu(reth->length);
1730 if (unlikely(offset + len != e->rdma_sge.sge_length))
1731 goto unlock_done;
1732 if (e->rdma_sge.mr) {
1733 atomic_dec(&e->rdma_sge.mr->refcount);
1734 e->rdma_sge.mr = NULL;
1735 }
1736 if (len != 0) {
1737 u32 rkey = be32_to_cpu(reth->rkey);
1738 u64 vaddr = be64_to_cpu(reth->vaddr);
1739 int ok;
1740
1741 ok = qib_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey,
1742 IB_ACCESS_REMOTE_READ);
1743 if (unlikely(!ok))
1744 goto unlock_done;
1745 } else {
1746 e->rdma_sge.vaddr = NULL;
1747 e->rdma_sge.length = 0;
1748 e->rdma_sge.sge_length = 0;
1749 }
1750 e->psn = psn;
1751 if (old_req)
1752 goto unlock_done;
1753 qp->s_tail_ack_queue = prev;
1754 break;
1755 }
1756
1757 case OP(COMPARE_SWAP):
1758 case OP(FETCH_ADD): {
1759 /*
1760 * If we didn't find the atomic request in the ack queue
1761 * or the send tasklet is already backed up to send an
1762 * earlier entry, we can ignore this request.
1763 */
1764 if (!e || e->opcode != (u8) opcode || old_req)
1765 goto unlock_done;
1766 qp->s_tail_ack_queue = prev;
1767 break;
1768 }
1769
1770 default:
1771 /*
1772 * Ignore this operation if it doesn't request an ACK
1773 * or an earlier RDMA read or atomic is going to be resent.
1774 */
1775 if (!(psn & IB_BTH_REQ_ACK) || old_req)
1776 goto unlock_done;
1777 /*
1778 * Resend the most recent ACK if this request is
1779 * after all the previous RDMA reads and atomics.
1780 */
1781 if (i == qp->r_head_ack_queue) {
1782 spin_unlock_irqrestore(&qp->s_lock, flags);
1783 qp->r_nak_state = 0;
1784 qp->r_ack_psn = qp->r_psn - 1;
1785 goto send_ack;
1786 }
1787 /*
1788 * Try to send a simple ACK to work around a Mellanox bug
1789 * which doesn't accept a RDMA read response or atomic
1790 * response as an ACK for earlier SENDs or RDMA writes.
1791 */
1792 if (!(qp->s_flags & QIB_S_RESP_PENDING)) {
1793 spin_unlock_irqrestore(&qp->s_lock, flags);
1794 qp->r_nak_state = 0;
1795 qp->r_ack_psn = qp->s_ack_queue[i].psn - 1;
1796 goto send_ack;
1797 }
1798 /*
1799 * Resend the RDMA read or atomic op which
1800 * ACKs this duplicate request.
1801 */
1802 qp->s_tail_ack_queue = i;
1803 break;
1804 }
1805 qp->s_ack_state = OP(ACKNOWLEDGE);
1806 qp->s_flags |= QIB_S_RESP_PENDING;
1807 qp->r_nak_state = 0;
1808 qib_schedule_send(qp);
1809
1810 unlock_done:
1811 spin_unlock_irqrestore(&qp->s_lock, flags);
1812 done:
1813 return 1;
1814
1815 send_ack:
1816 return 0;
1817 }
1818
qib_rc_error(struct qib_qp * qp,enum ib_wc_status err)1819 void qib_rc_error(struct qib_qp *qp, enum ib_wc_status err)
1820 {
1821 unsigned long flags;
1822 int lastwqe;
1823
1824 spin_lock_irqsave(&qp->s_lock, flags);
1825 lastwqe = qib_error_qp(qp, err);
1826 spin_unlock_irqrestore(&qp->s_lock, flags);
1827
1828 if (lastwqe) {
1829 struct ib_event ev;
1830
1831 ev.device = qp->ibqp.device;
1832 ev.element.qp = &qp->ibqp;
1833 ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
1834 qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
1835 }
1836 }
1837
qib_update_ack_queue(struct qib_qp * qp,unsigned n)1838 static inline void qib_update_ack_queue(struct qib_qp *qp, unsigned n)
1839 {
1840 unsigned next;
1841
1842 next = n + 1;
1843 if (next > QIB_MAX_RDMA_ATOMIC)
1844 next = 0;
1845 qp->s_tail_ack_queue = next;
1846 qp->s_ack_state = OP(ACKNOWLEDGE);
1847 }
1848
1849 /**
1850 * qib_rc_rcv - process an incoming RC packet
1851 * @rcd: the context pointer
1852 * @hdr: the header of this packet
1853 * @has_grh: true if the header has a GRH
1854 * @data: the packet data
1855 * @tlen: the packet length
1856 * @qp: the QP for this packet
1857 *
1858 * This is called from qib_qp_rcv() to process an incoming RC packet
1859 * for the given QP.
1860 * Called at interrupt level.
1861 */
qib_rc_rcv(struct qib_ctxtdata * rcd,struct qib_ib_header * hdr,int has_grh,void * data,u32 tlen,struct qib_qp * qp)1862 void qib_rc_rcv(struct qib_ctxtdata *rcd, struct qib_ib_header *hdr,
1863 int has_grh, void *data, u32 tlen, struct qib_qp *qp)
1864 {
1865 struct qib_ibport *ibp = &rcd->ppd->ibport_data;
1866 struct qib_other_headers *ohdr;
1867 u32 opcode;
1868 u32 hdrsize;
1869 u32 psn;
1870 u32 pad;
1871 struct ib_wc wc;
1872 u32 pmtu = qp->pmtu;
1873 int diff;
1874 struct ib_reth *reth;
1875 unsigned long flags;
1876 int ret;
1877
1878 /* Check for GRH */
1879 if (!has_grh) {
1880 ohdr = &hdr->u.oth;
1881 hdrsize = 8 + 12; /* LRH + BTH */
1882 } else {
1883 ohdr = &hdr->u.l.oth;
1884 hdrsize = 8 + 40 + 12; /* LRH + GRH + BTH */
1885 }
1886
1887 opcode = be32_to_cpu(ohdr->bth[0]);
1888 if (qib_ruc_check_hdr(ibp, hdr, has_grh, qp, opcode))
1889 return;
1890
1891 psn = be32_to_cpu(ohdr->bth[2]);
1892 opcode >>= 24;
1893
1894 /*
1895 * Process responses (ACKs) before anything else. Note that the
1896 * packet sequence number will be for something in the send work
1897 * queue rather than the expected receive packet sequence number.
1898 * In other words, this QP is the requester.
1899 */
1900 if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1901 opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
1902 qib_rc_rcv_resp(ibp, ohdr, data, tlen, qp, opcode, psn,
1903 hdrsize, pmtu, rcd);
1904 return;
1905 }
1906
1907 /* Compute 24 bits worth of difference. */
1908 diff = qib_cmp24(psn, qp->r_psn);
1909 if (unlikely(diff)) {
1910 if (qib_rc_rcv_error(ohdr, data, qp, opcode, psn, diff, rcd))
1911 return;
1912 goto send_ack;
1913 }
1914
1915 /* Check for opcode sequence errors. */
1916 switch (qp->r_state) {
1917 case OP(SEND_FIRST):
1918 case OP(SEND_MIDDLE):
1919 if (opcode == OP(SEND_MIDDLE) ||
1920 opcode == OP(SEND_LAST) ||
1921 opcode == OP(SEND_LAST_WITH_IMMEDIATE))
1922 break;
1923 goto nack_inv;
1924
1925 case OP(RDMA_WRITE_FIRST):
1926 case OP(RDMA_WRITE_MIDDLE):
1927 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
1928 opcode == OP(RDMA_WRITE_LAST) ||
1929 opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1930 break;
1931 goto nack_inv;
1932
1933 default:
1934 if (opcode == OP(SEND_MIDDLE) ||
1935 opcode == OP(SEND_LAST) ||
1936 opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
1937 opcode == OP(RDMA_WRITE_MIDDLE) ||
1938 opcode == OP(RDMA_WRITE_LAST) ||
1939 opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1940 goto nack_inv;
1941 /*
1942 * Note that it is up to the requester to not send a new
1943 * RDMA read or atomic operation before receiving an ACK
1944 * for the previous operation.
1945 */
1946 break;
1947 }
1948
1949 if (qp->state == IB_QPS_RTR && !(qp->r_flags & QIB_R_COMM_EST)) {
1950 qp->r_flags |= QIB_R_COMM_EST;
1951 if (qp->ibqp.event_handler) {
1952 struct ib_event ev;
1953
1954 ev.device = qp->ibqp.device;
1955 ev.element.qp = &qp->ibqp;
1956 ev.event = IB_EVENT_COMM_EST;
1957 qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
1958 }
1959 }
1960
1961 /* OK, process the packet. */
1962 switch (opcode) {
1963 case OP(SEND_FIRST):
1964 ret = qib_get_rwqe(qp, 0);
1965 if (ret < 0)
1966 goto nack_op_err;
1967 if (!ret)
1968 goto rnr_nak;
1969 qp->r_rcv_len = 0;
1970 /* FALLTHROUGH */
1971 case OP(SEND_MIDDLE):
1972 case OP(RDMA_WRITE_MIDDLE):
1973 send_middle:
1974 /* Check for invalid length PMTU or posted rwqe len. */
1975 if (unlikely(tlen != (hdrsize + pmtu + 4)))
1976 goto nack_inv;
1977 qp->r_rcv_len += pmtu;
1978 if (unlikely(qp->r_rcv_len > qp->r_len))
1979 goto nack_inv;
1980 qib_copy_sge(&qp->r_sge, data, pmtu, 1);
1981 break;
1982
1983 case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
1984 /* consume RWQE */
1985 ret = qib_get_rwqe(qp, 1);
1986 if (ret < 0)
1987 goto nack_op_err;
1988 if (!ret)
1989 goto rnr_nak;
1990 goto send_last_imm;
1991
1992 case OP(SEND_ONLY):
1993 case OP(SEND_ONLY_WITH_IMMEDIATE):
1994 ret = qib_get_rwqe(qp, 0);
1995 if (ret < 0)
1996 goto nack_op_err;
1997 if (!ret)
1998 goto rnr_nak;
1999 qp->r_rcv_len = 0;
2000 if (opcode == OP(SEND_ONLY))
2001 goto no_immediate_data;
2002 /* FALLTHROUGH for SEND_ONLY_WITH_IMMEDIATE */
2003 case OP(SEND_LAST_WITH_IMMEDIATE):
2004 send_last_imm:
2005 wc.ex.imm_data = ohdr->u.imm_data;
2006 hdrsize += 4;
2007 wc.wc_flags = IB_WC_WITH_IMM;
2008 goto send_last;
2009 case OP(SEND_LAST):
2010 case OP(RDMA_WRITE_LAST):
2011 no_immediate_data:
2012 wc.wc_flags = 0;
2013 wc.ex.imm_data = 0;
2014 send_last:
2015 /* Get the number of bytes the message was padded by. */
2016 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
2017 /* Check for invalid length. */
2018 /* XXX LAST len should be >= 1 */
2019 if (unlikely(tlen < (hdrsize + pad + 4)))
2020 goto nack_inv;
2021 /* Don't count the CRC. */
2022 tlen -= (hdrsize + pad + 4);
2023 wc.byte_len = tlen + qp->r_rcv_len;
2024 if (unlikely(wc.byte_len > qp->r_len))
2025 goto nack_inv;
2026 qib_copy_sge(&qp->r_sge, data, tlen, 1);
2027 while (qp->r_sge.num_sge) {
2028 atomic_dec(&qp->r_sge.sge.mr->refcount);
2029 if (--qp->r_sge.num_sge)
2030 qp->r_sge.sge = *qp->r_sge.sg_list++;
2031 }
2032 qp->r_msn++;
2033 if (!test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags))
2034 break;
2035 wc.wr_id = qp->r_wr_id;
2036 wc.status = IB_WC_SUCCESS;
2037 if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
2038 opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
2039 wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
2040 else
2041 wc.opcode = IB_WC_RECV;
2042 wc.qp = &qp->ibqp;
2043 wc.src_qp = qp->remote_qpn;
2044 wc.slid = qp->remote_ah_attr.dlid;
2045 wc.sl = qp->remote_ah_attr.sl;
2046 /* zero fields that are N/A */
2047 wc.vendor_err = 0;
2048 wc.pkey_index = 0;
2049 wc.dlid_path_bits = 0;
2050 wc.port_num = 0;
2051 /* Signal completion event if the solicited bit is set. */
2052 qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
2053 (ohdr->bth[0] &
2054 cpu_to_be32(IB_BTH_SOLICITED)) != 0);
2055 break;
2056
2057 case OP(RDMA_WRITE_FIRST):
2058 case OP(RDMA_WRITE_ONLY):
2059 case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
2060 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
2061 goto nack_inv;
2062 /* consume RWQE */
2063 reth = &ohdr->u.rc.reth;
2064 hdrsize += sizeof(*reth);
2065 qp->r_len = be32_to_cpu(reth->length);
2066 qp->r_rcv_len = 0;
2067 qp->r_sge.sg_list = NULL;
2068 if (qp->r_len != 0) {
2069 u32 rkey = be32_to_cpu(reth->rkey);
2070 u64 vaddr = be64_to_cpu(reth->vaddr);
2071 int ok;
2072
2073 /* Check rkey & NAK */
2074 ok = qib_rkey_ok(qp, &qp->r_sge.sge, qp->r_len, vaddr,
2075 rkey, IB_ACCESS_REMOTE_WRITE);
2076 if (unlikely(!ok))
2077 goto nack_acc;
2078 qp->r_sge.num_sge = 1;
2079 } else {
2080 qp->r_sge.num_sge = 0;
2081 qp->r_sge.sge.mr = NULL;
2082 qp->r_sge.sge.vaddr = NULL;
2083 qp->r_sge.sge.length = 0;
2084 qp->r_sge.sge.sge_length = 0;
2085 }
2086 if (opcode == OP(RDMA_WRITE_FIRST))
2087 goto send_middle;
2088 else if (opcode == OP(RDMA_WRITE_ONLY))
2089 goto no_immediate_data;
2090 ret = qib_get_rwqe(qp, 1);
2091 if (ret < 0)
2092 goto nack_op_err;
2093 if (!ret)
2094 goto rnr_nak;
2095 wc.ex.imm_data = ohdr->u.rc.imm_data;
2096 hdrsize += 4;
2097 wc.wc_flags = IB_WC_WITH_IMM;
2098 goto send_last;
2099
2100 case OP(RDMA_READ_REQUEST): {
2101 struct qib_ack_entry *e;
2102 u32 len;
2103 u8 next;
2104
2105 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
2106 goto nack_inv;
2107 next = qp->r_head_ack_queue + 1;
2108 /* s_ack_queue is size QIB_MAX_RDMA_ATOMIC+1 so use > not >= */
2109 if (next > QIB_MAX_RDMA_ATOMIC)
2110 next = 0;
2111 spin_lock_irqsave(&qp->s_lock, flags);
2112 if (unlikely(next == qp->s_tail_ack_queue)) {
2113 if (!qp->s_ack_queue[next].sent)
2114 goto nack_inv_unlck;
2115 qib_update_ack_queue(qp, next);
2116 }
2117 e = &qp->s_ack_queue[qp->r_head_ack_queue];
2118 if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
2119 atomic_dec(&e->rdma_sge.mr->refcount);
2120 e->rdma_sge.mr = NULL;
2121 }
2122 reth = &ohdr->u.rc.reth;
2123 len = be32_to_cpu(reth->length);
2124 if (len) {
2125 u32 rkey = be32_to_cpu(reth->rkey);
2126 u64 vaddr = be64_to_cpu(reth->vaddr);
2127 int ok;
2128
2129 /* Check rkey & NAK */
2130 ok = qib_rkey_ok(qp, &e->rdma_sge, len, vaddr,
2131 rkey, IB_ACCESS_REMOTE_READ);
2132 if (unlikely(!ok))
2133 goto nack_acc_unlck;
2134 /*
2135 * Update the next expected PSN. We add 1 later
2136 * below, so only add the remainder here.
2137 */
2138 if (len > pmtu)
2139 qp->r_psn += (len - 1) / pmtu;
2140 } else {
2141 e->rdma_sge.mr = NULL;
2142 e->rdma_sge.vaddr = NULL;
2143 e->rdma_sge.length = 0;
2144 e->rdma_sge.sge_length = 0;
2145 }
2146 e->opcode = opcode;
2147 e->sent = 0;
2148 e->psn = psn;
2149 e->lpsn = qp->r_psn;
2150 /*
2151 * We need to increment the MSN here instead of when we
2152 * finish sending the result since a duplicate request would
2153 * increment it more than once.
2154 */
2155 qp->r_msn++;
2156 qp->r_psn++;
2157 qp->r_state = opcode;
2158 qp->r_nak_state = 0;
2159 qp->r_head_ack_queue = next;
2160
2161 /* Schedule the send tasklet. */
2162 qp->s_flags |= QIB_S_RESP_PENDING;
2163 qib_schedule_send(qp);
2164
2165 goto sunlock;
2166 }
2167
2168 case OP(COMPARE_SWAP):
2169 case OP(FETCH_ADD): {
2170 struct ib_atomic_eth *ateth;
2171 struct qib_ack_entry *e;
2172 u64 vaddr;
2173 atomic64_t *maddr;
2174 u64 sdata;
2175 u32 rkey;
2176 u8 next;
2177
2178 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
2179 goto nack_inv;
2180 next = qp->r_head_ack_queue + 1;
2181 if (next > QIB_MAX_RDMA_ATOMIC)
2182 next = 0;
2183 spin_lock_irqsave(&qp->s_lock, flags);
2184 if (unlikely(next == qp->s_tail_ack_queue)) {
2185 if (!qp->s_ack_queue[next].sent)
2186 goto nack_inv_unlck;
2187 qib_update_ack_queue(qp, next);
2188 }
2189 e = &qp->s_ack_queue[qp->r_head_ack_queue];
2190 if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
2191 atomic_dec(&e->rdma_sge.mr->refcount);
2192 e->rdma_sge.mr = NULL;
2193 }
2194 ateth = &ohdr->u.atomic_eth;
2195 vaddr = ((u64) be32_to_cpu(ateth->vaddr[0]) << 32) |
2196 be32_to_cpu(ateth->vaddr[1]);
2197 if (unlikely(vaddr & (sizeof(u64) - 1)))
2198 goto nack_inv_unlck;
2199 rkey = be32_to_cpu(ateth->rkey);
2200 /* Check rkey & NAK */
2201 if (unlikely(!qib_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
2202 vaddr, rkey,
2203 IB_ACCESS_REMOTE_ATOMIC)))
2204 goto nack_acc_unlck;
2205 /* Perform atomic OP and save result. */
2206 maddr = (atomic64_t *) qp->r_sge.sge.vaddr;
2207 sdata = be64_to_cpu(ateth->swap_data);
2208 e->atomic_data = (opcode == OP(FETCH_ADD)) ?
2209 (u64) atomic64_add_return(sdata, maddr) - sdata :
2210 (u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr,
2211 be64_to_cpu(ateth->compare_data),
2212 sdata);
2213 atomic_dec(&qp->r_sge.sge.mr->refcount);
2214 qp->r_sge.num_sge = 0;
2215 e->opcode = opcode;
2216 e->sent = 0;
2217 e->psn = psn;
2218 e->lpsn = psn;
2219 qp->r_msn++;
2220 qp->r_psn++;
2221 qp->r_state = opcode;
2222 qp->r_nak_state = 0;
2223 qp->r_head_ack_queue = next;
2224
2225 /* Schedule the send tasklet. */
2226 qp->s_flags |= QIB_S_RESP_PENDING;
2227 qib_schedule_send(qp);
2228
2229 goto sunlock;
2230 }
2231
2232 default:
2233 /* NAK unknown opcodes. */
2234 goto nack_inv;
2235 }
2236 qp->r_psn++;
2237 qp->r_state = opcode;
2238 qp->r_ack_psn = psn;
2239 qp->r_nak_state = 0;
2240 /* Send an ACK if requested or required. */
2241 if (psn & (1 << 31))
2242 goto send_ack;
2243 return;
2244
2245 rnr_nak:
2246 qp->r_nak_state = IB_RNR_NAK | qp->r_min_rnr_timer;
2247 qp->r_ack_psn = qp->r_psn;
2248 /* Queue RNR NAK for later */
2249 if (list_empty(&qp->rspwait)) {
2250 qp->r_flags |= QIB_R_RSP_NAK;
2251 atomic_inc(&qp->refcount);
2252 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
2253 }
2254 return;
2255
2256 nack_op_err:
2257 qib_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
2258 qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR;
2259 qp->r_ack_psn = qp->r_psn;
2260 /* Queue NAK for later */
2261 if (list_empty(&qp->rspwait)) {
2262 qp->r_flags |= QIB_R_RSP_NAK;
2263 atomic_inc(&qp->refcount);
2264 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
2265 }
2266 return;
2267
2268 nack_inv_unlck:
2269 spin_unlock_irqrestore(&qp->s_lock, flags);
2270 nack_inv:
2271 qib_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
2272 qp->r_nak_state = IB_NAK_INVALID_REQUEST;
2273 qp->r_ack_psn = qp->r_psn;
2274 /* Queue NAK for later */
2275 if (list_empty(&qp->rspwait)) {
2276 qp->r_flags |= QIB_R_RSP_NAK;
2277 atomic_inc(&qp->refcount);
2278 list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
2279 }
2280 return;
2281
2282 nack_acc_unlck:
2283 spin_unlock_irqrestore(&qp->s_lock, flags);
2284 nack_acc:
2285 qib_rc_error(qp, IB_WC_LOC_PROT_ERR);
2286 qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
2287 qp->r_ack_psn = qp->r_psn;
2288 send_ack:
2289 qib_send_rc_ack(qp);
2290 return;
2291
2292 sunlock:
2293 spin_unlock_irqrestore(&qp->s_lock, flags);
2294 }
2295