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softlockup: fix watchdog task wakeup frequency
[mirror_ubuntu-hirsute-kernel.git] / drivers / infiniband / hw / ipath / ipath_rc.c
1 /*
2 * Copyright (c) 2006, 2007, 2008 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 "ipath_verbs.h"
37 #include "ipath_kernel.h"
38
39 /* cut down ridiculously long IB macro names */
40 #define OP(x) IB_OPCODE_RC_##x
41
42 static u32 restart_sge(struct ipath_sge_state *ss, struct ipath_swqe *wqe,
43 u32 psn, u32 pmtu)
44 {
45 u32 len;
46
47 len = ((psn - wqe->psn) & IPATH_PSN_MASK) * pmtu;
48 ss->sge = wqe->sg_list[0];
49 ss->sg_list = wqe->sg_list + 1;
50 ss->num_sge = wqe->wr.num_sge;
51 ipath_skip_sge(ss, len);
52 return wqe->length - len;
53 }
54
55 /**
56 * ipath_init_restart- initialize the qp->s_sge after a restart
57 * @qp: the QP who's SGE we're restarting
58 * @wqe: the work queue to initialize the QP's SGE from
59 *
60 * The QP s_lock should be held and interrupts disabled.
61 */
62 static void ipath_init_restart(struct ipath_qp *qp, struct ipath_swqe *wqe)
63 {
64 struct ipath_ibdev *dev;
65
66 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn,
67 ib_mtu_enum_to_int(qp->path_mtu));
68 dev = to_idev(qp->ibqp.device);
69 spin_lock(&dev->pending_lock);
70 if (list_empty(&qp->timerwait))
71 list_add_tail(&qp->timerwait,
72 &dev->pending[dev->pending_index]);
73 spin_unlock(&dev->pending_lock);
74 }
75
76 /**
77 * ipath_make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
78 * @qp: a pointer to the QP
79 * @ohdr: a pointer to the IB header being constructed
80 * @pmtu: the path MTU
81 *
82 * Return 1 if constructed; otherwise, return 0.
83 * Note that we are in the responder's side of the QP context.
84 * Note the QP s_lock must be held.
85 */
86 static int ipath_make_rc_ack(struct ipath_ibdev *dev, struct ipath_qp *qp,
87 struct ipath_other_headers *ohdr, u32 pmtu)
88 {
89 struct ipath_ack_entry *e;
90 u32 hwords;
91 u32 len;
92 u32 bth0;
93 u32 bth2;
94
95 /* Don't send an ACK if we aren't supposed to. */
96 if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
97 goto bail;
98
99 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
100 hwords = 5;
101
102 switch (qp->s_ack_state) {
103 case OP(RDMA_READ_RESPONSE_LAST):
104 case OP(RDMA_READ_RESPONSE_ONLY):
105 case OP(ATOMIC_ACKNOWLEDGE):
106 /*
107 * We can increment the tail pointer now that the last
108 * response has been sent instead of only being
109 * constructed.
110 */
111 if (++qp->s_tail_ack_queue > IPATH_MAX_RDMA_ATOMIC)
112 qp->s_tail_ack_queue = 0;
113 /* FALLTHROUGH */
114 case OP(SEND_ONLY):
115 case OP(ACKNOWLEDGE):
116 /* Check for no next entry in the queue. */
117 if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
118 if (qp->s_flags & IPATH_S_ACK_PENDING)
119 goto normal;
120 qp->s_ack_state = OP(ACKNOWLEDGE);
121 goto bail;
122 }
123
124 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
125 if (e->opcode == OP(RDMA_READ_REQUEST)) {
126 /* Copy SGE state in case we need to resend */
127 qp->s_ack_rdma_sge = e->rdma_sge;
128 qp->s_cur_sge = &qp->s_ack_rdma_sge;
129 len = e->rdma_sge.sge.sge_length;
130 if (len > pmtu) {
131 len = pmtu;
132 qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
133 } else {
134 qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
135 e->sent = 1;
136 }
137 ohdr->u.aeth = ipath_compute_aeth(qp);
138 hwords++;
139 qp->s_ack_rdma_psn = e->psn;
140 bth2 = qp->s_ack_rdma_psn++ & IPATH_PSN_MASK;
141 } else {
142 /* COMPARE_SWAP or FETCH_ADD */
143 qp->s_cur_sge = NULL;
144 len = 0;
145 qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
146 ohdr->u.at.aeth = ipath_compute_aeth(qp);
147 ohdr->u.at.atomic_ack_eth[0] =
148 cpu_to_be32(e->atomic_data >> 32);
149 ohdr->u.at.atomic_ack_eth[1] =
150 cpu_to_be32(e->atomic_data);
151 hwords += sizeof(ohdr->u.at) / sizeof(u32);
152 bth2 = e->psn;
153 e->sent = 1;
154 }
155 bth0 = qp->s_ack_state << 24;
156 break;
157
158 case OP(RDMA_READ_RESPONSE_FIRST):
159 qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
160 /* FALLTHROUGH */
161 case OP(RDMA_READ_RESPONSE_MIDDLE):
162 len = qp->s_ack_rdma_sge.sge.sge_length;
163 if (len > pmtu)
164 len = pmtu;
165 else {
166 ohdr->u.aeth = ipath_compute_aeth(qp);
167 hwords++;
168 qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
169 qp->s_ack_queue[qp->s_tail_ack_queue].sent = 1;
170 }
171 bth0 = qp->s_ack_state << 24;
172 bth2 = qp->s_ack_rdma_psn++ & IPATH_PSN_MASK;
173 break;
174
175 default:
176 normal:
177 /*
178 * Send a regular ACK.
179 * Set the s_ack_state so we wait until after sending
180 * the ACK before setting s_ack_state to ACKNOWLEDGE
181 * (see above).
182 */
183 qp->s_ack_state = OP(SEND_ONLY);
184 qp->s_flags &= ~IPATH_S_ACK_PENDING;
185 qp->s_cur_sge = NULL;
186 if (qp->s_nak_state)
187 ohdr->u.aeth =
188 cpu_to_be32((qp->r_msn & IPATH_MSN_MASK) |
189 (qp->s_nak_state <<
190 IPATH_AETH_CREDIT_SHIFT));
191 else
192 ohdr->u.aeth = ipath_compute_aeth(qp);
193 hwords++;
194 len = 0;
195 bth0 = OP(ACKNOWLEDGE) << 24;
196 bth2 = qp->s_ack_psn & IPATH_PSN_MASK;
197 }
198 qp->s_hdrwords = hwords;
199 qp->s_cur_size = len;
200 ipath_make_ruc_header(dev, qp, ohdr, bth0, bth2);
201 return 1;
202
203 bail:
204 return 0;
205 }
206
207 /**
208 * ipath_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
209 * @qp: a pointer to the QP
210 *
211 * Return 1 if constructed; otherwise, return 0.
212 */
213 int ipath_make_rc_req(struct ipath_qp *qp)
214 {
215 struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
216 struct ipath_other_headers *ohdr;
217 struct ipath_sge_state *ss;
218 struct ipath_swqe *wqe;
219 u32 hwords;
220 u32 len;
221 u32 bth0;
222 u32 bth2;
223 u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
224 char newreq;
225 unsigned long flags;
226 int ret = 0;
227
228 ohdr = &qp->s_hdr.u.oth;
229 if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
230 ohdr = &qp->s_hdr.u.l.oth;
231
232 /*
233 * The lock is needed to synchronize between the sending tasklet,
234 * the receive interrupt handler, and timeout resends.
235 */
236 spin_lock_irqsave(&qp->s_lock, flags);
237
238 /* Sending responses has higher priority over sending requests. */
239 if ((qp->r_head_ack_queue != qp->s_tail_ack_queue ||
240 (qp->s_flags & IPATH_S_ACK_PENDING) ||
241 qp->s_ack_state != OP(ACKNOWLEDGE)) &&
242 ipath_make_rc_ack(dev, qp, ohdr, pmtu))
243 goto done;
244
245 if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK)) {
246 if (!(ib_ipath_state_ops[qp->state] & IPATH_FLUSH_SEND))
247 goto bail;
248 /* We are in the error state, flush the work request. */
249 if (qp->s_last == qp->s_head)
250 goto bail;
251 /* If DMAs are in progress, we can't flush immediately. */
252 if (atomic_read(&qp->s_dma_busy)) {
253 qp->s_flags |= IPATH_S_WAIT_DMA;
254 goto bail;
255 }
256 wqe = get_swqe_ptr(qp, qp->s_last);
257 ipath_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
258 goto done;
259 }
260
261 /* Leave BUSY set until RNR timeout. */
262 if (qp->s_rnr_timeout) {
263 qp->s_flags |= IPATH_S_WAITING;
264 goto bail;
265 }
266
267 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
268 hwords = 5;
269 bth0 = 1 << 22; /* Set M bit */
270
271 /* Send a request. */
272 wqe = get_swqe_ptr(qp, qp->s_cur);
273 switch (qp->s_state) {
274 default:
275 if (!(ib_ipath_state_ops[qp->state] &
276 IPATH_PROCESS_NEXT_SEND_OK))
277 goto bail;
278 /*
279 * Resend an old request or start a new one.
280 *
281 * We keep track of the current SWQE so that
282 * we don't reset the "furthest progress" state
283 * if we need to back up.
284 */
285 newreq = 0;
286 if (qp->s_cur == qp->s_tail) {
287 /* Check if send work queue is empty. */
288 if (qp->s_tail == qp->s_head)
289 goto bail;
290 /*
291 * If a fence is requested, wait for previous
292 * RDMA read and atomic operations to finish.
293 */
294 if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
295 qp->s_num_rd_atomic) {
296 qp->s_flags |= IPATH_S_FENCE_PENDING;
297 goto bail;
298 }
299 wqe->psn = qp->s_next_psn;
300 newreq = 1;
301 }
302 /*
303 * Note that we have to be careful not to modify the
304 * original work request since we may need to resend
305 * it.
306 */
307 len = wqe->length;
308 ss = &qp->s_sge;
309 bth2 = 0;
310 switch (wqe->wr.opcode) {
311 case IB_WR_SEND:
312 case IB_WR_SEND_WITH_IMM:
313 /* If no credit, return. */
314 if (qp->s_lsn != (u32) -1 &&
315 ipath_cmp24(wqe->ssn, qp->s_lsn + 1) > 0) {
316 qp->s_flags |= IPATH_S_WAIT_SSN_CREDIT;
317 goto bail;
318 }
319 wqe->lpsn = wqe->psn;
320 if (len > pmtu) {
321 wqe->lpsn += (len - 1) / pmtu;
322 qp->s_state = OP(SEND_FIRST);
323 len = pmtu;
324 break;
325 }
326 if (wqe->wr.opcode == IB_WR_SEND)
327 qp->s_state = OP(SEND_ONLY);
328 else {
329 qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
330 /* Immediate data comes after the BTH */
331 ohdr->u.imm_data = wqe->wr.ex.imm_data;
332 hwords += 1;
333 }
334 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
335 bth0 |= 1 << 23;
336 bth2 = 1 << 31; /* Request ACK. */
337 if (++qp->s_cur == qp->s_size)
338 qp->s_cur = 0;
339 break;
340
341 case IB_WR_RDMA_WRITE:
342 if (newreq && qp->s_lsn != (u32) -1)
343 qp->s_lsn++;
344 /* FALLTHROUGH */
345 case IB_WR_RDMA_WRITE_WITH_IMM:
346 /* If no credit, return. */
347 if (qp->s_lsn != (u32) -1 &&
348 ipath_cmp24(wqe->ssn, qp->s_lsn + 1) > 0) {
349 qp->s_flags |= IPATH_S_WAIT_SSN_CREDIT;
350 goto bail;
351 }
352 ohdr->u.rc.reth.vaddr =
353 cpu_to_be64(wqe->wr.wr.rdma.remote_addr);
354 ohdr->u.rc.reth.rkey =
355 cpu_to_be32(wqe->wr.wr.rdma.rkey);
356 ohdr->u.rc.reth.length = cpu_to_be32(len);
357 hwords += sizeof(struct ib_reth) / sizeof(u32);
358 wqe->lpsn = wqe->psn;
359 if (len > pmtu) {
360 wqe->lpsn += (len - 1) / pmtu;
361 qp->s_state = OP(RDMA_WRITE_FIRST);
362 len = pmtu;
363 break;
364 }
365 if (wqe->wr.opcode == IB_WR_RDMA_WRITE)
366 qp->s_state = OP(RDMA_WRITE_ONLY);
367 else {
368 qp->s_state =
369 OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
370 /* Immediate data comes after RETH */
371 ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
372 hwords += 1;
373 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
374 bth0 |= 1 << 23;
375 }
376 bth2 = 1 << 31; /* Request ACK. */
377 if (++qp->s_cur == qp->s_size)
378 qp->s_cur = 0;
379 break;
380
381 case IB_WR_RDMA_READ:
382 /*
383 * Don't allow more operations to be started
384 * than the QP limits allow.
385 */
386 if (newreq) {
387 if (qp->s_num_rd_atomic >=
388 qp->s_max_rd_atomic) {
389 qp->s_flags |= IPATH_S_RDMAR_PENDING;
390 goto bail;
391 }
392 qp->s_num_rd_atomic++;
393 if (qp->s_lsn != (u32) -1)
394 qp->s_lsn++;
395 /*
396 * Adjust s_next_psn to count the
397 * expected number of responses.
398 */
399 if (len > pmtu)
400 qp->s_next_psn += (len - 1) / pmtu;
401 wqe->lpsn = qp->s_next_psn++;
402 }
403 ohdr->u.rc.reth.vaddr =
404 cpu_to_be64(wqe->wr.wr.rdma.remote_addr);
405 ohdr->u.rc.reth.rkey =
406 cpu_to_be32(wqe->wr.wr.rdma.rkey);
407 ohdr->u.rc.reth.length = cpu_to_be32(len);
408 qp->s_state = OP(RDMA_READ_REQUEST);
409 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
410 ss = NULL;
411 len = 0;
412 if (++qp->s_cur == qp->s_size)
413 qp->s_cur = 0;
414 break;
415
416 case IB_WR_ATOMIC_CMP_AND_SWP:
417 case IB_WR_ATOMIC_FETCH_AND_ADD:
418 /*
419 * Don't allow more operations to be started
420 * than the QP limits allow.
421 */
422 if (newreq) {
423 if (qp->s_num_rd_atomic >=
424 qp->s_max_rd_atomic) {
425 qp->s_flags |= IPATH_S_RDMAR_PENDING;
426 goto bail;
427 }
428 qp->s_num_rd_atomic++;
429 if (qp->s_lsn != (u32) -1)
430 qp->s_lsn++;
431 wqe->lpsn = wqe->psn;
432 }
433 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP) {
434 qp->s_state = OP(COMPARE_SWAP);
435 ohdr->u.atomic_eth.swap_data = cpu_to_be64(
436 wqe->wr.wr.atomic.swap);
437 ohdr->u.atomic_eth.compare_data = cpu_to_be64(
438 wqe->wr.wr.atomic.compare_add);
439 } else {
440 qp->s_state = OP(FETCH_ADD);
441 ohdr->u.atomic_eth.swap_data = cpu_to_be64(
442 wqe->wr.wr.atomic.compare_add);
443 ohdr->u.atomic_eth.compare_data = 0;
444 }
445 ohdr->u.atomic_eth.vaddr[0] = cpu_to_be32(
446 wqe->wr.wr.atomic.remote_addr >> 32);
447 ohdr->u.atomic_eth.vaddr[1] = cpu_to_be32(
448 wqe->wr.wr.atomic.remote_addr);
449 ohdr->u.atomic_eth.rkey = cpu_to_be32(
450 wqe->wr.wr.atomic.rkey);
451 hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
452 ss = NULL;
453 len = 0;
454 if (++qp->s_cur == qp->s_size)
455 qp->s_cur = 0;
456 break;
457
458 default:
459 goto bail;
460 }
461 qp->s_sge.sge = wqe->sg_list[0];
462 qp->s_sge.sg_list = wqe->sg_list + 1;
463 qp->s_sge.num_sge = wqe->wr.num_sge;
464 qp->s_len = wqe->length;
465 if (newreq) {
466 qp->s_tail++;
467 if (qp->s_tail >= qp->s_size)
468 qp->s_tail = 0;
469 }
470 bth2 |= qp->s_psn & IPATH_PSN_MASK;
471 if (wqe->wr.opcode == IB_WR_RDMA_READ)
472 qp->s_psn = wqe->lpsn + 1;
473 else {
474 qp->s_psn++;
475 if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
476 qp->s_next_psn = qp->s_psn;
477 }
478 /*
479 * Put the QP on the pending list so lost ACKs will cause
480 * a retry. More than one request can be pending so the
481 * QP may already be on the dev->pending list.
482 */
483 spin_lock(&dev->pending_lock);
484 if (list_empty(&qp->timerwait))
485 list_add_tail(&qp->timerwait,
486 &dev->pending[dev->pending_index]);
487 spin_unlock(&dev->pending_lock);
488 break;
489
490 case OP(RDMA_READ_RESPONSE_FIRST):
491 /*
492 * This case can only happen if a send is restarted.
493 * See ipath_restart_rc().
494 */
495 ipath_init_restart(qp, wqe);
496 /* FALLTHROUGH */
497 case OP(SEND_FIRST):
498 qp->s_state = OP(SEND_MIDDLE);
499 /* FALLTHROUGH */
500 case OP(SEND_MIDDLE):
501 bth2 = qp->s_psn++ & IPATH_PSN_MASK;
502 if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
503 qp->s_next_psn = qp->s_psn;
504 ss = &qp->s_sge;
505 len = qp->s_len;
506 if (len > pmtu) {
507 len = pmtu;
508 break;
509 }
510 if (wqe->wr.opcode == IB_WR_SEND)
511 qp->s_state = OP(SEND_LAST);
512 else {
513 qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
514 /* Immediate data comes after the BTH */
515 ohdr->u.imm_data = wqe->wr.ex.imm_data;
516 hwords += 1;
517 }
518 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
519 bth0 |= 1 << 23;
520 bth2 |= 1 << 31; /* Request ACK. */
521 qp->s_cur++;
522 if (qp->s_cur >= qp->s_size)
523 qp->s_cur = 0;
524 break;
525
526 case OP(RDMA_READ_RESPONSE_LAST):
527 /*
528 * This case can only happen if a RDMA write is restarted.
529 * See ipath_restart_rc().
530 */
531 ipath_init_restart(qp, wqe);
532 /* FALLTHROUGH */
533 case OP(RDMA_WRITE_FIRST):
534 qp->s_state = OP(RDMA_WRITE_MIDDLE);
535 /* FALLTHROUGH */
536 case OP(RDMA_WRITE_MIDDLE):
537 bth2 = qp->s_psn++ & IPATH_PSN_MASK;
538 if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
539 qp->s_next_psn = qp->s_psn;
540 ss = &qp->s_sge;
541 len = qp->s_len;
542 if (len > pmtu) {
543 len = pmtu;
544 break;
545 }
546 if (wqe->wr.opcode == IB_WR_RDMA_WRITE)
547 qp->s_state = OP(RDMA_WRITE_LAST);
548 else {
549 qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
550 /* Immediate data comes after the BTH */
551 ohdr->u.imm_data = wqe->wr.ex.imm_data;
552 hwords += 1;
553 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
554 bth0 |= 1 << 23;
555 }
556 bth2 |= 1 << 31; /* Request ACK. */
557 qp->s_cur++;
558 if (qp->s_cur >= qp->s_size)
559 qp->s_cur = 0;
560 break;
561
562 case OP(RDMA_READ_RESPONSE_MIDDLE):
563 /*
564 * This case can only happen if a RDMA read is restarted.
565 * See ipath_restart_rc().
566 */
567 ipath_init_restart(qp, wqe);
568 len = ((qp->s_psn - wqe->psn) & IPATH_PSN_MASK) * pmtu;
569 ohdr->u.rc.reth.vaddr =
570 cpu_to_be64(wqe->wr.wr.rdma.remote_addr + len);
571 ohdr->u.rc.reth.rkey =
572 cpu_to_be32(wqe->wr.wr.rdma.rkey);
573 ohdr->u.rc.reth.length = cpu_to_be32(qp->s_len);
574 qp->s_state = OP(RDMA_READ_REQUEST);
575 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
576 bth2 = qp->s_psn++ & IPATH_PSN_MASK;
577 if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
578 qp->s_next_psn = qp->s_psn;
579 ss = NULL;
580 len = 0;
581 qp->s_cur++;
582 if (qp->s_cur == qp->s_size)
583 qp->s_cur = 0;
584 break;
585 }
586 if (ipath_cmp24(qp->s_psn, qp->s_last_psn + IPATH_PSN_CREDIT - 1) >= 0)
587 bth2 |= 1 << 31; /* Request ACK. */
588 qp->s_len -= len;
589 qp->s_hdrwords = hwords;
590 qp->s_cur_sge = ss;
591 qp->s_cur_size = len;
592 ipath_make_ruc_header(dev, qp, ohdr, bth0 | (qp->s_state << 24), bth2);
593 done:
594 ret = 1;
595 goto unlock;
596
597 bail:
598 qp->s_flags &= ~IPATH_S_BUSY;
599 unlock:
600 spin_unlock_irqrestore(&qp->s_lock, flags);
601 return ret;
602 }
603
604 /**
605 * send_rc_ack - Construct an ACK packet and send it
606 * @qp: a pointer to the QP
607 *
608 * This is called from ipath_rc_rcv() and only uses the receive
609 * side QP state.
610 * Note that RDMA reads and atomics are handled in the
611 * send side QP state and tasklet.
612 */
613 static void send_rc_ack(struct ipath_qp *qp)
614 {
615 struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
616 struct ipath_devdata *dd;
617 u16 lrh0;
618 u32 bth0;
619 u32 hwords;
620 u32 __iomem *piobuf;
621 struct ipath_ib_header hdr;
622 struct ipath_other_headers *ohdr;
623 unsigned long flags;
624
625 spin_lock_irqsave(&qp->s_lock, flags);
626
627 /* Don't send ACK or NAK if a RDMA read or atomic is pending. */
628 if (qp->r_head_ack_queue != qp->s_tail_ack_queue ||
629 (qp->s_flags & IPATH_S_ACK_PENDING) ||
630 qp->s_ack_state != OP(ACKNOWLEDGE))
631 goto queue_ack;
632
633 spin_unlock_irqrestore(&qp->s_lock, flags);
634
635 /* Don't try to send ACKs if the link isn't ACTIVE */
636 dd = dev->dd;
637 if (!(dd->ipath_flags & IPATH_LINKACTIVE))
638 goto done;
639
640 piobuf = ipath_getpiobuf(dd, 0, NULL);
641 if (!piobuf) {
642 /*
643 * We are out of PIO buffers at the moment.
644 * Pass responsibility for sending the ACK to the
645 * send tasklet so that when a PIO buffer becomes
646 * available, the ACK is sent ahead of other outgoing
647 * packets.
648 */
649 spin_lock_irqsave(&qp->s_lock, flags);
650 goto queue_ack;
651 }
652
653 /* Construct the header. */
654 ohdr = &hdr.u.oth;
655 lrh0 = IPATH_LRH_BTH;
656 /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4. */
657 hwords = 6;
658 if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
659 hwords += ipath_make_grh(dev, &hdr.u.l.grh,
660 &qp->remote_ah_attr.grh,
661 hwords, 0);
662 ohdr = &hdr.u.l.oth;
663 lrh0 = IPATH_LRH_GRH;
664 }
665 /* read pkey_index w/o lock (its atomic) */
666 bth0 = ipath_get_pkey(dd, qp->s_pkey_index) |
667 (OP(ACKNOWLEDGE) << 24) | (1 << 22);
668 if (qp->r_nak_state)
669 ohdr->u.aeth = cpu_to_be32((qp->r_msn & IPATH_MSN_MASK) |
670 (qp->r_nak_state <<
671 IPATH_AETH_CREDIT_SHIFT));
672 else
673 ohdr->u.aeth = ipath_compute_aeth(qp);
674 lrh0 |= qp->remote_ah_attr.sl << 4;
675 hdr.lrh[0] = cpu_to_be16(lrh0);
676 hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
677 hdr.lrh[2] = cpu_to_be16(hwords + SIZE_OF_CRC);
678 hdr.lrh[3] = cpu_to_be16(dd->ipath_lid);
679 ohdr->bth[0] = cpu_to_be32(bth0);
680 ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
681 ohdr->bth[2] = cpu_to_be32(qp->r_ack_psn & IPATH_PSN_MASK);
682
683 writeq(hwords + 1, piobuf);
684
685 if (dd->ipath_flags & IPATH_PIO_FLUSH_WC) {
686 u32 *hdrp = (u32 *) &hdr;
687
688 ipath_flush_wc();
689 __iowrite32_copy(piobuf + 2, hdrp, hwords - 1);
690 ipath_flush_wc();
691 __raw_writel(hdrp[hwords - 1], piobuf + hwords + 1);
692 } else
693 __iowrite32_copy(piobuf + 2, (u32 *) &hdr, hwords);
694
695 ipath_flush_wc();
696
697 dev->n_unicast_xmit++;
698 goto done;
699
700 queue_ack:
701 if (ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK) {
702 dev->n_rc_qacks++;
703 qp->s_flags |= IPATH_S_ACK_PENDING;
704 qp->s_nak_state = qp->r_nak_state;
705 qp->s_ack_psn = qp->r_ack_psn;
706
707 /* Schedule the send tasklet. */
708 ipath_schedule_send(qp);
709 }
710 spin_unlock_irqrestore(&qp->s_lock, flags);
711 done:
712 return;
713 }
714
715 /**
716 * reset_psn - reset the QP state to send starting from PSN
717 * @qp: the QP
718 * @psn: the packet sequence number to restart at
719 *
720 * This is called from ipath_rc_rcv() to process an incoming RC ACK
721 * for the given QP.
722 * Called at interrupt level with the QP s_lock held.
723 */
724 static void reset_psn(struct ipath_qp *qp, u32 psn)
725 {
726 u32 n = qp->s_last;
727 struct ipath_swqe *wqe = get_swqe_ptr(qp, n);
728 u32 opcode;
729
730 qp->s_cur = n;
731
732 /*
733 * If we are starting the request from the beginning,
734 * let the normal send code handle initialization.
735 */
736 if (ipath_cmp24(psn, wqe->psn) <= 0) {
737 qp->s_state = OP(SEND_LAST);
738 goto done;
739 }
740
741 /* Find the work request opcode corresponding to the given PSN. */
742 opcode = wqe->wr.opcode;
743 for (;;) {
744 int diff;
745
746 if (++n == qp->s_size)
747 n = 0;
748 if (n == qp->s_tail)
749 break;
750 wqe = get_swqe_ptr(qp, n);
751 diff = ipath_cmp24(psn, wqe->psn);
752 if (diff < 0)
753 break;
754 qp->s_cur = n;
755 /*
756 * If we are starting the request from the beginning,
757 * let the normal send code handle initialization.
758 */
759 if (diff == 0) {
760 qp->s_state = OP(SEND_LAST);
761 goto done;
762 }
763 opcode = wqe->wr.opcode;
764 }
765
766 /*
767 * Set the state to restart in the middle of a request.
768 * Don't change the s_sge, s_cur_sge, or s_cur_size.
769 * See ipath_make_rc_req().
770 */
771 switch (opcode) {
772 case IB_WR_SEND:
773 case IB_WR_SEND_WITH_IMM:
774 qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
775 break;
776
777 case IB_WR_RDMA_WRITE:
778 case IB_WR_RDMA_WRITE_WITH_IMM:
779 qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
780 break;
781
782 case IB_WR_RDMA_READ:
783 qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
784 break;
785
786 default:
787 /*
788 * This case shouldn't happen since its only
789 * one PSN per req.
790 */
791 qp->s_state = OP(SEND_LAST);
792 }
793 done:
794 qp->s_psn = psn;
795 }
796
797 /**
798 * ipath_restart_rc - back up requester to resend the last un-ACKed request
799 * @qp: the QP to restart
800 * @psn: packet sequence number for the request
801 * @wc: the work completion request
802 *
803 * The QP s_lock should be held and interrupts disabled.
804 */
805 void ipath_restart_rc(struct ipath_qp *qp, u32 psn)
806 {
807 struct ipath_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
808 struct ipath_ibdev *dev;
809
810 if (qp->s_retry == 0) {
811 ipath_send_complete(qp, wqe, IB_WC_RETRY_EXC_ERR);
812 ipath_error_qp(qp, IB_WC_WR_FLUSH_ERR);
813 goto bail;
814 }
815 qp->s_retry--;
816
817 /*
818 * Remove the QP from the timeout queue.
819 * Note: it may already have been removed by ipath_ib_timer().
820 */
821 dev = to_idev(qp->ibqp.device);
822 spin_lock(&dev->pending_lock);
823 if (!list_empty(&qp->timerwait))
824 list_del_init(&qp->timerwait);
825 if (!list_empty(&qp->piowait))
826 list_del_init(&qp->piowait);
827 spin_unlock(&dev->pending_lock);
828
829 if (wqe->wr.opcode == IB_WR_RDMA_READ)
830 dev->n_rc_resends++;
831 else
832 dev->n_rc_resends += (qp->s_psn - psn) & IPATH_PSN_MASK;
833
834 reset_psn(qp, psn);
835 ipath_schedule_send(qp);
836
837 bail:
838 return;
839 }
840
841 static inline void update_last_psn(struct ipath_qp *qp, u32 psn)
842 {
843 qp->s_last_psn = psn;
844 }
845
846 /**
847 * do_rc_ack - process an incoming RC ACK
848 * @qp: the QP the ACK came in on
849 * @psn: the packet sequence number of the ACK
850 * @opcode: the opcode of the request that resulted in the ACK
851 *
852 * This is called from ipath_rc_rcv_resp() to process an incoming RC ACK
853 * for the given QP.
854 * Called at interrupt level with the QP s_lock held and interrupts disabled.
855 * Returns 1 if OK, 0 if current operation should be aborted (NAK).
856 */
857 static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode,
858 u64 val)
859 {
860 struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
861 struct ib_wc wc;
862 enum ib_wc_status status;
863 struct ipath_swqe *wqe;
864 int ret = 0;
865 u32 ack_psn;
866 int diff;
867
868 /*
869 * Remove the QP from the timeout queue (or RNR timeout queue).
870 * If ipath_ib_timer() has already removed it,
871 * it's OK since we hold the QP s_lock and ipath_restart_rc()
872 * just won't find anything to restart if we ACK everything.
873 */
874 spin_lock(&dev->pending_lock);
875 if (!list_empty(&qp->timerwait))
876 list_del_init(&qp->timerwait);
877 spin_unlock(&dev->pending_lock);
878
879 /*
880 * Note that NAKs implicitly ACK outstanding SEND and RDMA write
881 * requests and implicitly NAK RDMA read and atomic requests issued
882 * before the NAK'ed request. The MSN won't include the NAK'ed
883 * request but will include an ACK'ed request(s).
884 */
885 ack_psn = psn;
886 if (aeth >> 29)
887 ack_psn--;
888 wqe = get_swqe_ptr(qp, qp->s_last);
889
890 /*
891 * The MSN might be for a later WQE than the PSN indicates so
892 * only complete WQEs that the PSN finishes.
893 */
894 while ((diff = ipath_cmp24(ack_psn, wqe->lpsn)) >= 0) {
895 /*
896 * RDMA_READ_RESPONSE_ONLY is a special case since
897 * we want to generate completion events for everything
898 * before the RDMA read, copy the data, then generate
899 * the completion for the read.
900 */
901 if (wqe->wr.opcode == IB_WR_RDMA_READ &&
902 opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
903 diff == 0) {
904 ret = 1;
905 goto bail;
906 }
907 /*
908 * If this request is a RDMA read or atomic, and the ACK is
909 * for a later operation, this ACK NAKs the RDMA read or
910 * atomic. In other words, only a RDMA_READ_LAST or ONLY
911 * can ACK a RDMA read and likewise for atomic ops. Note
912 * that the NAK case can only happen if relaxed ordering is
913 * used and requests are sent after an RDMA read or atomic
914 * is sent but before the response is received.
915 */
916 if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
917 (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
918 ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
919 wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
920 (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0))) {
921 /*
922 * The last valid PSN seen is the previous
923 * request's.
924 */
925 update_last_psn(qp, wqe->psn - 1);
926 /* Retry this request. */
927 ipath_restart_rc(qp, wqe->psn);
928 /*
929 * No need to process the ACK/NAK since we are
930 * restarting an earlier request.
931 */
932 goto bail;
933 }
934 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
935 wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
936 *(u64 *) wqe->sg_list[0].vaddr = val;
937 if (qp->s_num_rd_atomic &&
938 (wqe->wr.opcode == IB_WR_RDMA_READ ||
939 wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
940 wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
941 qp->s_num_rd_atomic--;
942 /* Restart sending task if fence is complete */
943 if (((qp->s_flags & IPATH_S_FENCE_PENDING) &&
944 !qp->s_num_rd_atomic) ||
945 qp->s_flags & IPATH_S_RDMAR_PENDING)
946 ipath_schedule_send(qp);
947 }
948 /* Post a send completion queue entry if requested. */
949 if (!(qp->s_flags & IPATH_S_SIGNAL_REQ_WR) ||
950 (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
951 memset(&wc, 0, sizeof wc);
952 wc.wr_id = wqe->wr.wr_id;
953 wc.status = IB_WC_SUCCESS;
954 wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
955 wc.byte_len = wqe->length;
956 wc.qp = &qp->ibqp;
957 wc.src_qp = qp->remote_qpn;
958 wc.slid = qp->remote_ah_attr.dlid;
959 wc.sl = qp->remote_ah_attr.sl;
960 ipath_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 0);
961 }
962 qp->s_retry = qp->s_retry_cnt;
963 /*
964 * If we are completing a request which is in the process of
965 * being resent, we can stop resending it since we know the
966 * responder has already seen it.
967 */
968 if (qp->s_last == qp->s_cur) {
969 if (++qp->s_cur >= qp->s_size)
970 qp->s_cur = 0;
971 qp->s_last = qp->s_cur;
972 if (qp->s_last == qp->s_tail)
973 break;
974 wqe = get_swqe_ptr(qp, qp->s_cur);
975 qp->s_state = OP(SEND_LAST);
976 qp->s_psn = wqe->psn;
977 } else {
978 if (++qp->s_last >= qp->s_size)
979 qp->s_last = 0;
980 if (qp->state == IB_QPS_SQD && qp->s_last == qp->s_cur)
981 qp->s_draining = 0;
982 if (qp->s_last == qp->s_tail)
983 break;
984 wqe = get_swqe_ptr(qp, qp->s_last);
985 }
986 }
987
988 switch (aeth >> 29) {
989 case 0: /* ACK */
990 dev->n_rc_acks++;
991 /* If this is a partial ACK, reset the retransmit timer. */
992 if (qp->s_last != qp->s_tail) {
993 spin_lock(&dev->pending_lock);
994 if (list_empty(&qp->timerwait))
995 list_add_tail(&qp->timerwait,
996 &dev->pending[dev->pending_index]);
997 spin_unlock(&dev->pending_lock);
998 /*
999 * If we get a partial ACK for a resent operation,
1000 * we can stop resending the earlier packets and
1001 * continue with the next packet the receiver wants.
1002 */
1003 if (ipath_cmp24(qp->s_psn, psn) <= 0) {
1004 reset_psn(qp, psn + 1);
1005 ipath_schedule_send(qp);
1006 }
1007 } else if (ipath_cmp24(qp->s_psn, psn) <= 0) {
1008 qp->s_state = OP(SEND_LAST);
1009 qp->s_psn = psn + 1;
1010 }
1011 ipath_get_credit(qp, aeth);
1012 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1013 qp->s_retry = qp->s_retry_cnt;
1014 update_last_psn(qp, psn);
1015 ret = 1;
1016 goto bail;
1017
1018 case 1: /* RNR NAK */
1019 dev->n_rnr_naks++;
1020 if (qp->s_last == qp->s_tail)
1021 goto bail;
1022 if (qp->s_rnr_retry == 0) {
1023 status = IB_WC_RNR_RETRY_EXC_ERR;
1024 goto class_b;
1025 }
1026 if (qp->s_rnr_retry_cnt < 7)
1027 qp->s_rnr_retry--;
1028
1029 /* The last valid PSN is the previous PSN. */
1030 update_last_psn(qp, psn - 1);
1031
1032 if (wqe->wr.opcode == IB_WR_RDMA_READ)
1033 dev->n_rc_resends++;
1034 else
1035 dev->n_rc_resends +=
1036 (qp->s_psn - psn) & IPATH_PSN_MASK;
1037
1038 reset_psn(qp, psn);
1039
1040 qp->s_rnr_timeout =
1041 ib_ipath_rnr_table[(aeth >> IPATH_AETH_CREDIT_SHIFT) &
1042 IPATH_AETH_CREDIT_MASK];
1043 ipath_insert_rnr_queue(qp);
1044 ipath_schedule_send(qp);
1045 goto bail;
1046
1047 case 3: /* NAK */
1048 if (qp->s_last == qp->s_tail)
1049 goto bail;
1050 /* The last valid PSN is the previous PSN. */
1051 update_last_psn(qp, psn - 1);
1052 switch ((aeth >> IPATH_AETH_CREDIT_SHIFT) &
1053 IPATH_AETH_CREDIT_MASK) {
1054 case 0: /* PSN sequence error */
1055 dev->n_seq_naks++;
1056 /*
1057 * Back up to the responder's expected PSN.
1058 * Note that we might get a NAK in the middle of an
1059 * RDMA READ response which terminates the RDMA
1060 * READ.
1061 */
1062 ipath_restart_rc(qp, psn);
1063 break;
1064
1065 case 1: /* Invalid Request */
1066 status = IB_WC_REM_INV_REQ_ERR;
1067 dev->n_other_naks++;
1068 goto class_b;
1069
1070 case 2: /* Remote Access Error */
1071 status = IB_WC_REM_ACCESS_ERR;
1072 dev->n_other_naks++;
1073 goto class_b;
1074
1075 case 3: /* Remote Operation Error */
1076 status = IB_WC_REM_OP_ERR;
1077 dev->n_other_naks++;
1078 class_b:
1079 ipath_send_complete(qp, wqe, status);
1080 ipath_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1081 break;
1082
1083 default:
1084 /* Ignore other reserved NAK error codes */
1085 goto reserved;
1086 }
1087 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1088 goto bail;
1089
1090 default: /* 2: reserved */
1091 reserved:
1092 /* Ignore reserved NAK codes. */
1093 goto bail;
1094 }
1095
1096 bail:
1097 return ret;
1098 }
1099
1100 /**
1101 * ipath_rc_rcv_resp - process an incoming RC response packet
1102 * @dev: the device this packet came in on
1103 * @ohdr: the other headers for this packet
1104 * @data: the packet data
1105 * @tlen: the packet length
1106 * @qp: the QP for this packet
1107 * @opcode: the opcode for this packet
1108 * @psn: the packet sequence number for this packet
1109 * @hdrsize: the header length
1110 * @pmtu: the path MTU
1111 * @header_in_data: true if part of the header data is in the data buffer
1112 *
1113 * This is called from ipath_rc_rcv() to process an incoming RC response
1114 * packet for the given QP.
1115 * Called at interrupt level.
1116 */
1117 static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
1118 struct ipath_other_headers *ohdr,
1119 void *data, u32 tlen,
1120 struct ipath_qp *qp,
1121 u32 opcode,
1122 u32 psn, u32 hdrsize, u32 pmtu,
1123 int header_in_data)
1124 {
1125 struct ipath_swqe *wqe;
1126 enum ib_wc_status status;
1127 unsigned long flags;
1128 int diff;
1129 u32 pad;
1130 u32 aeth;
1131 u64 val;
1132
1133 spin_lock_irqsave(&qp->s_lock, flags);
1134
1135 /* Double check we can process this now that we hold the s_lock. */
1136 if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1137 goto ack_done;
1138
1139 /* Ignore invalid responses. */
1140 if (ipath_cmp24(psn, qp->s_next_psn) >= 0)
1141 goto ack_done;
1142
1143 /* Ignore duplicate responses. */
1144 diff = ipath_cmp24(psn, qp->s_last_psn);
1145 if (unlikely(diff <= 0)) {
1146 /* Update credits for "ghost" ACKs */
1147 if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
1148 if (!header_in_data)
1149 aeth = be32_to_cpu(ohdr->u.aeth);
1150 else {
1151 aeth = be32_to_cpu(((__be32 *) data)[0]);
1152 data += sizeof(__be32);
1153 }
1154 if ((aeth >> 29) == 0)
1155 ipath_get_credit(qp, aeth);
1156 }
1157 goto ack_done;
1158 }
1159
1160 if (unlikely(qp->s_last == qp->s_tail))
1161 goto ack_done;
1162 wqe = get_swqe_ptr(qp, qp->s_last);
1163 status = IB_WC_SUCCESS;
1164
1165 switch (opcode) {
1166 case OP(ACKNOWLEDGE):
1167 case OP(ATOMIC_ACKNOWLEDGE):
1168 case OP(RDMA_READ_RESPONSE_FIRST):
1169 if (!header_in_data)
1170 aeth = be32_to_cpu(ohdr->u.aeth);
1171 else {
1172 aeth = be32_to_cpu(((__be32 *) data)[0]);
1173 data += sizeof(__be32);
1174 }
1175 if (opcode == OP(ATOMIC_ACKNOWLEDGE)) {
1176 if (!header_in_data) {
1177 __be32 *p = ohdr->u.at.atomic_ack_eth;
1178
1179 val = ((u64) be32_to_cpu(p[0]) << 32) |
1180 be32_to_cpu(p[1]);
1181 } else
1182 val = be64_to_cpu(((__be64 *) data)[0]);
1183 } else
1184 val = 0;
1185 if (!do_rc_ack(qp, aeth, psn, opcode, val) ||
1186 opcode != OP(RDMA_READ_RESPONSE_FIRST))
1187 goto ack_done;
1188 hdrsize += 4;
1189 wqe = get_swqe_ptr(qp, qp->s_last);
1190 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1191 goto ack_op_err;
1192 qp->r_flags &= ~IPATH_R_RDMAR_SEQ;
1193 /*
1194 * If this is a response to a resent RDMA read, we
1195 * have to be careful to copy the data to the right
1196 * location.
1197 */
1198 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1199 wqe, psn, pmtu);
1200 goto read_middle;
1201
1202 case OP(RDMA_READ_RESPONSE_MIDDLE):
1203 /* no AETH, no ACK */
1204 if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
1205 dev->n_rdma_seq++;
1206 if (qp->r_flags & IPATH_R_RDMAR_SEQ)
1207 goto ack_done;
1208 qp->r_flags |= IPATH_R_RDMAR_SEQ;
1209 ipath_restart_rc(qp, qp->s_last_psn + 1);
1210 goto ack_done;
1211 }
1212 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1213 goto ack_op_err;
1214 read_middle:
1215 if (unlikely(tlen != (hdrsize + pmtu + 4)))
1216 goto ack_len_err;
1217 if (unlikely(pmtu >= qp->s_rdma_read_len))
1218 goto ack_len_err;
1219
1220 /* We got a response so update the timeout. */
1221 spin_lock(&dev->pending_lock);
1222 if (qp->s_rnr_timeout == 0 && !list_empty(&qp->timerwait))
1223 list_move_tail(&qp->timerwait,
1224 &dev->pending[dev->pending_index]);
1225 spin_unlock(&dev->pending_lock);
1226
1227 if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
1228 qp->s_retry = qp->s_retry_cnt;
1229
1230 /*
1231 * Update the RDMA receive state but do the copy w/o
1232 * holding the locks and blocking interrupts.
1233 */
1234 qp->s_rdma_read_len -= pmtu;
1235 update_last_psn(qp, psn);
1236 spin_unlock_irqrestore(&qp->s_lock, flags);
1237 ipath_copy_sge(&qp->s_rdma_read_sge, data, pmtu);
1238 goto bail;
1239
1240 case OP(RDMA_READ_RESPONSE_ONLY):
1241 if (!header_in_data)
1242 aeth = be32_to_cpu(ohdr->u.aeth);
1243 else
1244 aeth = be32_to_cpu(((__be32 *) data)[0]);
1245 if (!do_rc_ack(qp, aeth, psn, opcode, 0))
1246 goto ack_done;
1247 /* Get the number of bytes the message was padded by. */
1248 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1249 /*
1250 * Check that the data size is >= 0 && <= pmtu.
1251 * Remember to account for the AETH header (4) and
1252 * ICRC (4).
1253 */
1254 if (unlikely(tlen < (hdrsize + pad + 8)))
1255 goto ack_len_err;
1256 /*
1257 * If this is a response to a resent RDMA read, we
1258 * have to be careful to copy the data to the right
1259 * location.
1260 */
1261 wqe = get_swqe_ptr(qp, qp->s_last);
1262 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1263 wqe, psn, pmtu);
1264 goto read_last;
1265
1266 case OP(RDMA_READ_RESPONSE_LAST):
1267 /* ACKs READ req. */
1268 if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
1269 dev->n_rdma_seq++;
1270 if (qp->r_flags & IPATH_R_RDMAR_SEQ)
1271 goto ack_done;
1272 qp->r_flags |= IPATH_R_RDMAR_SEQ;
1273 ipath_restart_rc(qp, qp->s_last_psn + 1);
1274 goto ack_done;
1275 }
1276 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1277 goto ack_op_err;
1278 /* Get the number of bytes the message was padded by. */
1279 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1280 /*
1281 * Check that the data size is >= 1 && <= pmtu.
1282 * Remember to account for the AETH header (4) and
1283 * ICRC (4).
1284 */
1285 if (unlikely(tlen <= (hdrsize + pad + 8)))
1286 goto ack_len_err;
1287 read_last:
1288 tlen -= hdrsize + pad + 8;
1289 if (unlikely(tlen != qp->s_rdma_read_len))
1290 goto ack_len_err;
1291 if (!header_in_data)
1292 aeth = be32_to_cpu(ohdr->u.aeth);
1293 else {
1294 aeth = be32_to_cpu(((__be32 *) data)[0]);
1295 data += sizeof(__be32);
1296 }
1297 ipath_copy_sge(&qp->s_rdma_read_sge, data, tlen);
1298 (void) do_rc_ack(qp, aeth, psn,
1299 OP(RDMA_READ_RESPONSE_LAST), 0);
1300 goto ack_done;
1301 }
1302
1303 ack_op_err:
1304 status = IB_WC_LOC_QP_OP_ERR;
1305 goto ack_err;
1306
1307 ack_len_err:
1308 status = IB_WC_LOC_LEN_ERR;
1309 ack_err:
1310 ipath_send_complete(qp, wqe, status);
1311 ipath_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1312 ack_done:
1313 spin_unlock_irqrestore(&qp->s_lock, flags);
1314 bail:
1315 return;
1316 }
1317
1318 /**
1319 * ipath_rc_rcv_error - process an incoming duplicate or error RC packet
1320 * @dev: the device this packet came in on
1321 * @ohdr: the other headers for this packet
1322 * @data: the packet data
1323 * @qp: the QP for this packet
1324 * @opcode: the opcode for this packet
1325 * @psn: the packet sequence number for this packet
1326 * @diff: the difference between the PSN and the expected PSN
1327 * @header_in_data: true if part of the header data is in the data buffer
1328 *
1329 * This is called from ipath_rc_rcv() to process an unexpected
1330 * incoming RC packet for the given QP.
1331 * Called at interrupt level.
1332 * Return 1 if no more processing is needed; otherwise return 0 to
1333 * schedule a response to be sent.
1334 */
1335 static inline int ipath_rc_rcv_error(struct ipath_ibdev *dev,
1336 struct ipath_other_headers *ohdr,
1337 void *data,
1338 struct ipath_qp *qp,
1339 u32 opcode,
1340 u32 psn,
1341 int diff,
1342 int header_in_data)
1343 {
1344 struct ipath_ack_entry *e;
1345 u8 i, prev;
1346 int old_req;
1347 unsigned long flags;
1348
1349 if (diff > 0) {
1350 /*
1351 * Packet sequence error.
1352 * A NAK will ACK earlier sends and RDMA writes.
1353 * Don't queue the NAK if we already sent one.
1354 */
1355 if (!qp->r_nak_state) {
1356 qp->r_nak_state = IB_NAK_PSN_ERROR;
1357 /* Use the expected PSN. */
1358 qp->r_ack_psn = qp->r_psn;
1359 goto send_ack;
1360 }
1361 goto done;
1362 }
1363
1364 /*
1365 * Handle a duplicate request. Don't re-execute SEND, RDMA
1366 * write or atomic op. Don't NAK errors, just silently drop
1367 * the duplicate request. Note that r_sge, r_len, and
1368 * r_rcv_len may be in use so don't modify them.
1369 *
1370 * We are supposed to ACK the earliest duplicate PSN but we
1371 * can coalesce an outstanding duplicate ACK. We have to
1372 * send the earliest so that RDMA reads can be restarted at
1373 * the requester's expected PSN.
1374 *
1375 * First, find where this duplicate PSN falls within the
1376 * ACKs previously sent.
1377 */
1378 psn &= IPATH_PSN_MASK;
1379 e = NULL;
1380 old_req = 1;
1381
1382 spin_lock_irqsave(&qp->s_lock, flags);
1383 /* Double check we can process this now that we hold the s_lock. */
1384 if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1385 goto unlock_done;
1386
1387 for (i = qp->r_head_ack_queue; ; i = prev) {
1388 if (i == qp->s_tail_ack_queue)
1389 old_req = 0;
1390 if (i)
1391 prev = i - 1;
1392 else
1393 prev = IPATH_MAX_RDMA_ATOMIC;
1394 if (prev == qp->r_head_ack_queue) {
1395 e = NULL;
1396 break;
1397 }
1398 e = &qp->s_ack_queue[prev];
1399 if (!e->opcode) {
1400 e = NULL;
1401 break;
1402 }
1403 if (ipath_cmp24(psn, e->psn) >= 0) {
1404 if (prev == qp->s_tail_ack_queue)
1405 old_req = 0;
1406 break;
1407 }
1408 }
1409 switch (opcode) {
1410 case OP(RDMA_READ_REQUEST): {
1411 struct ib_reth *reth;
1412 u32 offset;
1413 u32 len;
1414
1415 /*
1416 * If we didn't find the RDMA read request in the ack queue,
1417 * or the send tasklet is already backed up to send an
1418 * earlier entry, we can ignore this request.
1419 */
1420 if (!e || e->opcode != OP(RDMA_READ_REQUEST) || old_req)
1421 goto unlock_done;
1422 /* RETH comes after BTH */
1423 if (!header_in_data)
1424 reth = &ohdr->u.rc.reth;
1425 else {
1426 reth = (struct ib_reth *)data;
1427 data += sizeof(*reth);
1428 }
1429 /*
1430 * Address range must be a subset of the original
1431 * request and start on pmtu boundaries.
1432 * We reuse the old ack_queue slot since the requester
1433 * should not back up and request an earlier PSN for the
1434 * same request.
1435 */
1436 offset = ((psn - e->psn) & IPATH_PSN_MASK) *
1437 ib_mtu_enum_to_int(qp->path_mtu);
1438 len = be32_to_cpu(reth->length);
1439 if (unlikely(offset + len > e->rdma_sge.sge.sge_length))
1440 goto unlock_done;
1441 if (len != 0) {
1442 u32 rkey = be32_to_cpu(reth->rkey);
1443 u64 vaddr = be64_to_cpu(reth->vaddr);
1444 int ok;
1445
1446 ok = ipath_rkey_ok(qp, &e->rdma_sge,
1447 len, vaddr, rkey,
1448 IB_ACCESS_REMOTE_READ);
1449 if (unlikely(!ok))
1450 goto unlock_done;
1451 } else {
1452 e->rdma_sge.sg_list = NULL;
1453 e->rdma_sge.num_sge = 0;
1454 e->rdma_sge.sge.mr = NULL;
1455 e->rdma_sge.sge.vaddr = NULL;
1456 e->rdma_sge.sge.length = 0;
1457 e->rdma_sge.sge.sge_length = 0;
1458 }
1459 e->psn = psn;
1460 qp->s_ack_state = OP(ACKNOWLEDGE);
1461 qp->s_tail_ack_queue = prev;
1462 break;
1463 }
1464
1465 case OP(COMPARE_SWAP):
1466 case OP(FETCH_ADD): {
1467 /*
1468 * If we didn't find the atomic request in the ack queue
1469 * or the send tasklet is already backed up to send an
1470 * earlier entry, we can ignore this request.
1471 */
1472 if (!e || e->opcode != (u8) opcode || old_req)
1473 goto unlock_done;
1474 qp->s_ack_state = OP(ACKNOWLEDGE);
1475 qp->s_tail_ack_queue = prev;
1476 break;
1477 }
1478
1479 default:
1480 if (old_req)
1481 goto unlock_done;
1482 /*
1483 * Resend the most recent ACK if this request is
1484 * after all the previous RDMA reads and atomics.
1485 */
1486 if (i == qp->r_head_ack_queue) {
1487 spin_unlock_irqrestore(&qp->s_lock, flags);
1488 qp->r_nak_state = 0;
1489 qp->r_ack_psn = qp->r_psn - 1;
1490 goto send_ack;
1491 }
1492 /*
1493 * Try to send a simple ACK to work around a Mellanox bug
1494 * which doesn't accept a RDMA read response or atomic
1495 * response as an ACK for earlier SENDs or RDMA writes.
1496 */
1497 if (qp->r_head_ack_queue == qp->s_tail_ack_queue &&
1498 !(qp->s_flags & IPATH_S_ACK_PENDING) &&
1499 qp->s_ack_state == OP(ACKNOWLEDGE)) {
1500 spin_unlock_irqrestore(&qp->s_lock, flags);
1501 qp->r_nak_state = 0;
1502 qp->r_ack_psn = qp->s_ack_queue[i].psn - 1;
1503 goto send_ack;
1504 }
1505 /*
1506 * Resend the RDMA read or atomic op which
1507 * ACKs this duplicate request.
1508 */
1509 qp->s_ack_state = OP(ACKNOWLEDGE);
1510 qp->s_tail_ack_queue = i;
1511 break;
1512 }
1513 qp->r_nak_state = 0;
1514 ipath_schedule_send(qp);
1515
1516 unlock_done:
1517 spin_unlock_irqrestore(&qp->s_lock, flags);
1518 done:
1519 return 1;
1520
1521 send_ack:
1522 return 0;
1523 }
1524
1525 void ipath_rc_error(struct ipath_qp *qp, enum ib_wc_status err)
1526 {
1527 unsigned long flags;
1528 int lastwqe;
1529
1530 spin_lock_irqsave(&qp->s_lock, flags);
1531 lastwqe = ipath_error_qp(qp, err);
1532 spin_unlock_irqrestore(&qp->s_lock, flags);
1533
1534 if (lastwqe) {
1535 struct ib_event ev;
1536
1537 ev.device = qp->ibqp.device;
1538 ev.element.qp = &qp->ibqp;
1539 ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
1540 qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
1541 }
1542 }
1543
1544 static inline void ipath_update_ack_queue(struct ipath_qp *qp, unsigned n)
1545 {
1546 unsigned next;
1547
1548 next = n + 1;
1549 if (next > IPATH_MAX_RDMA_ATOMIC)
1550 next = 0;
1551 if (n == qp->s_tail_ack_queue) {
1552 qp->s_tail_ack_queue = next;
1553 qp->s_ack_state = OP(ACKNOWLEDGE);
1554 }
1555 }
1556
1557 /**
1558 * ipath_rc_rcv - process an incoming RC packet
1559 * @dev: the device this packet came in on
1560 * @hdr: the header of this packet
1561 * @has_grh: true if the header has a GRH
1562 * @data: the packet data
1563 * @tlen: the packet length
1564 * @qp: the QP for this packet
1565 *
1566 * This is called from ipath_qp_rcv() to process an incoming RC packet
1567 * for the given QP.
1568 * Called at interrupt level.
1569 */
1570 void ipath_rc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
1571 int has_grh, void *data, u32 tlen, struct ipath_qp *qp)
1572 {
1573 struct ipath_other_headers *ohdr;
1574 u32 opcode;
1575 u32 hdrsize;
1576 u32 psn;
1577 u32 pad;
1578 struct ib_wc wc;
1579 u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
1580 int diff;
1581 struct ib_reth *reth;
1582 int header_in_data;
1583 unsigned long flags;
1584
1585 /* Validate the SLID. See Ch. 9.6.1.5 */
1586 if (unlikely(be16_to_cpu(hdr->lrh[3]) != qp->remote_ah_attr.dlid))
1587 goto done;
1588
1589 /* Check for GRH */
1590 if (!has_grh) {
1591 ohdr = &hdr->u.oth;
1592 hdrsize = 8 + 12; /* LRH + BTH */
1593 psn = be32_to_cpu(ohdr->bth[2]);
1594 header_in_data = 0;
1595 } else {
1596 ohdr = &hdr->u.l.oth;
1597 hdrsize = 8 + 40 + 12; /* LRH + GRH + BTH */
1598 /*
1599 * The header with GRH is 60 bytes and the core driver sets
1600 * the eager header buffer size to 56 bytes so the last 4
1601 * bytes of the BTH header (PSN) is in the data buffer.
1602 */
1603 header_in_data = dev->dd->ipath_rcvhdrentsize == 16;
1604 if (header_in_data) {
1605 psn = be32_to_cpu(((__be32 *) data)[0]);
1606 data += sizeof(__be32);
1607 } else
1608 psn = be32_to_cpu(ohdr->bth[2]);
1609 }
1610
1611 /*
1612 * Process responses (ACKs) before anything else. Note that the
1613 * packet sequence number will be for something in the send work
1614 * queue rather than the expected receive packet sequence number.
1615 * In other words, this QP is the requester.
1616 */
1617 opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
1618 if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1619 opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
1620 ipath_rc_rcv_resp(dev, ohdr, data, tlen, qp, opcode, psn,
1621 hdrsize, pmtu, header_in_data);
1622 goto done;
1623 }
1624
1625 /* Compute 24 bits worth of difference. */
1626 diff = ipath_cmp24(psn, qp->r_psn);
1627 if (unlikely(diff)) {
1628 if (ipath_rc_rcv_error(dev, ohdr, data, qp, opcode,
1629 psn, diff, header_in_data))
1630 goto done;
1631 goto send_ack;
1632 }
1633
1634 /* Check for opcode sequence errors. */
1635 switch (qp->r_state) {
1636 case OP(SEND_FIRST):
1637 case OP(SEND_MIDDLE):
1638 if (opcode == OP(SEND_MIDDLE) ||
1639 opcode == OP(SEND_LAST) ||
1640 opcode == OP(SEND_LAST_WITH_IMMEDIATE))
1641 break;
1642 goto nack_inv;
1643
1644 case OP(RDMA_WRITE_FIRST):
1645 case OP(RDMA_WRITE_MIDDLE):
1646 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
1647 opcode == OP(RDMA_WRITE_LAST) ||
1648 opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1649 break;
1650 goto nack_inv;
1651
1652 default:
1653 if (opcode == OP(SEND_MIDDLE) ||
1654 opcode == OP(SEND_LAST) ||
1655 opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
1656 opcode == OP(RDMA_WRITE_MIDDLE) ||
1657 opcode == OP(RDMA_WRITE_LAST) ||
1658 opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1659 goto nack_inv;
1660 /*
1661 * Note that it is up to the requester to not send a new
1662 * RDMA read or atomic operation before receiving an ACK
1663 * for the previous operation.
1664 */
1665 break;
1666 }
1667
1668 memset(&wc, 0, sizeof wc);
1669
1670 /* OK, process the packet. */
1671 switch (opcode) {
1672 case OP(SEND_FIRST):
1673 if (!ipath_get_rwqe(qp, 0))
1674 goto rnr_nak;
1675 qp->r_rcv_len = 0;
1676 /* FALLTHROUGH */
1677 case OP(SEND_MIDDLE):
1678 case OP(RDMA_WRITE_MIDDLE):
1679 send_middle:
1680 /* Check for invalid length PMTU or posted rwqe len. */
1681 if (unlikely(tlen != (hdrsize + pmtu + 4)))
1682 goto nack_inv;
1683 qp->r_rcv_len += pmtu;
1684 if (unlikely(qp->r_rcv_len > qp->r_len))
1685 goto nack_inv;
1686 ipath_copy_sge(&qp->r_sge, data, pmtu);
1687 break;
1688
1689 case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
1690 /* consume RWQE */
1691 if (!ipath_get_rwqe(qp, 1))
1692 goto rnr_nak;
1693 goto send_last_imm;
1694
1695 case OP(SEND_ONLY):
1696 case OP(SEND_ONLY_WITH_IMMEDIATE):
1697 if (!ipath_get_rwqe(qp, 0))
1698 goto rnr_nak;
1699 qp->r_rcv_len = 0;
1700 if (opcode == OP(SEND_ONLY))
1701 goto send_last;
1702 /* FALLTHROUGH */
1703 case OP(SEND_LAST_WITH_IMMEDIATE):
1704 send_last_imm:
1705 if (header_in_data) {
1706 wc.imm_data = *(__be32 *) data;
1707 data += sizeof(__be32);
1708 } else {
1709 /* Immediate data comes after BTH */
1710 wc.imm_data = ohdr->u.imm_data;
1711 }
1712 hdrsize += 4;
1713 wc.wc_flags = IB_WC_WITH_IMM;
1714 /* FALLTHROUGH */
1715 case OP(SEND_LAST):
1716 case OP(RDMA_WRITE_LAST):
1717 send_last:
1718 /* Get the number of bytes the message was padded by. */
1719 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1720 /* Check for invalid length. */
1721 /* XXX LAST len should be >= 1 */
1722 if (unlikely(tlen < (hdrsize + pad + 4)))
1723 goto nack_inv;
1724 /* Don't count the CRC. */
1725 tlen -= (hdrsize + pad + 4);
1726 wc.byte_len = tlen + qp->r_rcv_len;
1727 if (unlikely(wc.byte_len > qp->r_len))
1728 goto nack_inv;
1729 ipath_copy_sge(&qp->r_sge, data, tlen);
1730 qp->r_msn++;
1731 if (!test_and_clear_bit(IPATH_R_WRID_VALID, &qp->r_aflags))
1732 break;
1733 wc.wr_id = qp->r_wr_id;
1734 wc.status = IB_WC_SUCCESS;
1735 if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
1736 opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
1737 wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
1738 else
1739 wc.opcode = IB_WC_RECV;
1740 wc.qp = &qp->ibqp;
1741 wc.src_qp = qp->remote_qpn;
1742 wc.slid = qp->remote_ah_attr.dlid;
1743 wc.sl = qp->remote_ah_attr.sl;
1744 /* Signal completion event if the solicited bit is set. */
1745 ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
1746 (ohdr->bth[0] &
1747 __constant_cpu_to_be32(1 << 23)) != 0);
1748 break;
1749
1750 case OP(RDMA_WRITE_FIRST):
1751 case OP(RDMA_WRITE_ONLY):
1752 case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
1753 if (unlikely(!(qp->qp_access_flags &
1754 IB_ACCESS_REMOTE_WRITE)))
1755 goto nack_inv;
1756 /* consume RWQE */
1757 /* RETH comes after BTH */
1758 if (!header_in_data)
1759 reth = &ohdr->u.rc.reth;
1760 else {
1761 reth = (struct ib_reth *)data;
1762 data += sizeof(*reth);
1763 }
1764 hdrsize += sizeof(*reth);
1765 qp->r_len = be32_to_cpu(reth->length);
1766 qp->r_rcv_len = 0;
1767 if (qp->r_len != 0) {
1768 u32 rkey = be32_to_cpu(reth->rkey);
1769 u64 vaddr = be64_to_cpu(reth->vaddr);
1770 int ok;
1771
1772 /* Check rkey & NAK */
1773 ok = ipath_rkey_ok(qp, &qp->r_sge,
1774 qp->r_len, vaddr, rkey,
1775 IB_ACCESS_REMOTE_WRITE);
1776 if (unlikely(!ok))
1777 goto nack_acc;
1778 } else {
1779 qp->r_sge.sg_list = NULL;
1780 qp->r_sge.sge.mr = NULL;
1781 qp->r_sge.sge.vaddr = NULL;
1782 qp->r_sge.sge.length = 0;
1783 qp->r_sge.sge.sge_length = 0;
1784 }
1785 if (opcode == OP(RDMA_WRITE_FIRST))
1786 goto send_middle;
1787 else if (opcode == OP(RDMA_WRITE_ONLY))
1788 goto send_last;
1789 if (!ipath_get_rwqe(qp, 1))
1790 goto rnr_nak;
1791 goto send_last_imm;
1792
1793 case OP(RDMA_READ_REQUEST): {
1794 struct ipath_ack_entry *e;
1795 u32 len;
1796 u8 next;
1797
1798 if (unlikely(!(qp->qp_access_flags &
1799 IB_ACCESS_REMOTE_READ)))
1800 goto nack_inv;
1801 next = qp->r_head_ack_queue + 1;
1802 if (next > IPATH_MAX_RDMA_ATOMIC)
1803 next = 0;
1804 spin_lock_irqsave(&qp->s_lock, flags);
1805 /* Double check we can process this while holding the s_lock. */
1806 if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1807 goto unlock;
1808 if (unlikely(next == qp->s_tail_ack_queue)) {
1809 if (!qp->s_ack_queue[next].sent)
1810 goto nack_inv_unlck;
1811 ipath_update_ack_queue(qp, next);
1812 }
1813 e = &qp->s_ack_queue[qp->r_head_ack_queue];
1814 /* RETH comes after BTH */
1815 if (!header_in_data)
1816 reth = &ohdr->u.rc.reth;
1817 else {
1818 reth = (struct ib_reth *)data;
1819 data += sizeof(*reth);
1820 }
1821 len = be32_to_cpu(reth->length);
1822 if (len) {
1823 u32 rkey = be32_to_cpu(reth->rkey);
1824 u64 vaddr = be64_to_cpu(reth->vaddr);
1825 int ok;
1826
1827 /* Check rkey & NAK */
1828 ok = ipath_rkey_ok(qp, &e->rdma_sge, len, vaddr,
1829 rkey, IB_ACCESS_REMOTE_READ);
1830 if (unlikely(!ok))
1831 goto nack_acc_unlck;
1832 /*
1833 * Update the next expected PSN. We add 1 later
1834 * below, so only add the remainder here.
1835 */
1836 if (len > pmtu)
1837 qp->r_psn += (len - 1) / pmtu;
1838 } else {
1839 e->rdma_sge.sg_list = NULL;
1840 e->rdma_sge.num_sge = 0;
1841 e->rdma_sge.sge.mr = NULL;
1842 e->rdma_sge.sge.vaddr = NULL;
1843 e->rdma_sge.sge.length = 0;
1844 e->rdma_sge.sge.sge_length = 0;
1845 }
1846 e->opcode = opcode;
1847 e->sent = 0;
1848 e->psn = psn;
1849 /*
1850 * We need to increment the MSN here instead of when we
1851 * finish sending the result since a duplicate request would
1852 * increment it more than once.
1853 */
1854 qp->r_msn++;
1855 qp->r_psn++;
1856 qp->r_state = opcode;
1857 qp->r_nak_state = 0;
1858 qp->r_head_ack_queue = next;
1859
1860 /* Schedule the send tasklet. */
1861 ipath_schedule_send(qp);
1862
1863 goto unlock;
1864 }
1865
1866 case OP(COMPARE_SWAP):
1867 case OP(FETCH_ADD): {
1868 struct ib_atomic_eth *ateth;
1869 struct ipath_ack_entry *e;
1870 u64 vaddr;
1871 atomic64_t *maddr;
1872 u64 sdata;
1873 u32 rkey;
1874 u8 next;
1875
1876 if (unlikely(!(qp->qp_access_flags &
1877 IB_ACCESS_REMOTE_ATOMIC)))
1878 goto nack_inv;
1879 next = qp->r_head_ack_queue + 1;
1880 if (next > IPATH_MAX_RDMA_ATOMIC)
1881 next = 0;
1882 spin_lock_irqsave(&qp->s_lock, flags);
1883 /* Double check we can process this while holding the s_lock. */
1884 if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1885 goto unlock;
1886 if (unlikely(next == qp->s_tail_ack_queue)) {
1887 if (!qp->s_ack_queue[next].sent)
1888 goto nack_inv_unlck;
1889 ipath_update_ack_queue(qp, next);
1890 }
1891 if (!header_in_data)
1892 ateth = &ohdr->u.atomic_eth;
1893 else
1894 ateth = (struct ib_atomic_eth *)data;
1895 vaddr = ((u64) be32_to_cpu(ateth->vaddr[0]) << 32) |
1896 be32_to_cpu(ateth->vaddr[1]);
1897 if (unlikely(vaddr & (sizeof(u64) - 1)))
1898 goto nack_inv_unlck;
1899 rkey = be32_to_cpu(ateth->rkey);
1900 /* Check rkey & NAK */
1901 if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge,
1902 sizeof(u64), vaddr, rkey,
1903 IB_ACCESS_REMOTE_ATOMIC)))
1904 goto nack_acc_unlck;
1905 /* Perform atomic OP and save result. */
1906 maddr = (atomic64_t *) qp->r_sge.sge.vaddr;
1907 sdata = be64_to_cpu(ateth->swap_data);
1908 e = &qp->s_ack_queue[qp->r_head_ack_queue];
1909 e->atomic_data = (opcode == OP(FETCH_ADD)) ?
1910 (u64) atomic64_add_return(sdata, maddr) - sdata :
1911 (u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr,
1912 be64_to_cpu(ateth->compare_data),
1913 sdata);
1914 e->opcode = opcode;
1915 e->sent = 0;
1916 e->psn = psn & IPATH_PSN_MASK;
1917 qp->r_msn++;
1918 qp->r_psn++;
1919 qp->r_state = opcode;
1920 qp->r_nak_state = 0;
1921 qp->r_head_ack_queue = next;
1922
1923 /* Schedule the send tasklet. */
1924 ipath_schedule_send(qp);
1925
1926 goto unlock;
1927 }
1928
1929 default:
1930 /* NAK unknown opcodes. */
1931 goto nack_inv;
1932 }
1933 qp->r_psn++;
1934 qp->r_state = opcode;
1935 qp->r_ack_psn = psn;
1936 qp->r_nak_state = 0;
1937 /* Send an ACK if requested or required. */
1938 if (psn & (1 << 31))
1939 goto send_ack;
1940 goto done;
1941
1942 rnr_nak:
1943 qp->r_nak_state = IB_RNR_NAK | qp->r_min_rnr_timer;
1944 qp->r_ack_psn = qp->r_psn;
1945 goto send_ack;
1946
1947 nack_inv_unlck:
1948 spin_unlock_irqrestore(&qp->s_lock, flags);
1949 nack_inv:
1950 ipath_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
1951 qp->r_nak_state = IB_NAK_INVALID_REQUEST;
1952 qp->r_ack_psn = qp->r_psn;
1953 goto send_ack;
1954
1955 nack_acc_unlck:
1956 spin_unlock_irqrestore(&qp->s_lock, flags);
1957 nack_acc:
1958 ipath_rc_error(qp, IB_WC_LOC_PROT_ERR);
1959 qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
1960 qp->r_ack_psn = qp->r_psn;
1961 send_ack:
1962 send_rc_ack(qp);
1963 goto done;
1964
1965 unlock:
1966 spin_unlock_irqrestore(&qp->s_lock, flags);
1967 done:
1968 return;
1969 }
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