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IB/ipath: Fix a race condition when generating ACKs
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / infiniband / hw / ipath / ipath_rc.c
1 /*
2 * Copyright (c) 2006 QLogic, Inc. 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 "ipath_verbs.h"
35 #include "ipath_kernel.h"
36
37 /* cut down ridiculously long IB macro names */
38 #define OP(x) IB_OPCODE_RC_##x
39
40 static u32 restart_sge(struct ipath_sge_state *ss, struct ipath_swqe *wqe,
41 u32 psn, u32 pmtu)
42 {
43 u32 len;
44
45 len = ((psn - wqe->psn) & IPATH_PSN_MASK) * pmtu;
46 ss->sge = wqe->sg_list[0];
47 ss->sg_list = wqe->sg_list + 1;
48 ss->num_sge = wqe->wr.num_sge;
49 ipath_skip_sge(ss, len);
50 return wqe->length - len;
51 }
52
53 /**
54 * ipath_init_restart- initialize the qp->s_sge after a restart
55 * @qp: the QP who's SGE we're restarting
56 * @wqe: the work queue to initialize the QP's SGE from
57 *
58 * The QP s_lock should be held and interrupts disabled.
59 */
60 static void ipath_init_restart(struct ipath_qp *qp, struct ipath_swqe *wqe)
61 {
62 struct ipath_ibdev *dev;
63
64 qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn,
65 ib_mtu_enum_to_int(qp->path_mtu));
66 dev = to_idev(qp->ibqp.device);
67 spin_lock(&dev->pending_lock);
68 if (list_empty(&qp->timerwait))
69 list_add_tail(&qp->timerwait,
70 &dev->pending[dev->pending_index]);
71 spin_unlock(&dev->pending_lock);
72 }
73
74 /**
75 * ipath_make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
76 * @qp: a pointer to the QP
77 * @ohdr: a pointer to the IB header being constructed
78 * @pmtu: the path MTU
79 *
80 * Return 1 if constructed; otherwise, return 0.
81 * Note that we are in the responder's side of the QP context.
82 * Note the QP s_lock must be held.
83 */
84 static int ipath_make_rc_ack(struct ipath_qp *qp,
85 struct ipath_other_headers *ohdr,
86 u32 pmtu, u32 *bth0p, u32 *bth2p)
87 {
88 struct ipath_ack_entry *e;
89 u32 hwords;
90 u32 len;
91 u32 bth0;
92 u32 bth2;
93
94 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
95 hwords = 5;
96
97 switch (qp->s_ack_state) {
98 case OP(RDMA_READ_RESPONSE_LAST):
99 case OP(RDMA_READ_RESPONSE_ONLY):
100 case OP(ATOMIC_ACKNOWLEDGE):
101 /*
102 * We can increment the tail pointer now that the last
103 * response has been sent instead of only being
104 * constructed.
105 */
106 if (++qp->s_tail_ack_queue > IPATH_MAX_RDMA_ATOMIC)
107 qp->s_tail_ack_queue = 0;
108 /* FALLTHROUGH */
109 case OP(SEND_ONLY):
110 case OP(ACKNOWLEDGE):
111 /* Check for no next entry in the queue. */
112 if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
113 if (qp->s_flags & IPATH_S_ACK_PENDING)
114 goto normal;
115 qp->s_ack_state = OP(ACKNOWLEDGE);
116 goto bail;
117 }
118
119 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
120 if (e->opcode == OP(RDMA_READ_REQUEST)) {
121 /* Copy SGE state in case we need to resend */
122 qp->s_ack_rdma_sge = e->rdma_sge;
123 qp->s_cur_sge = &qp->s_ack_rdma_sge;
124 len = e->rdma_sge.sge.sge_length;
125 if (len > pmtu) {
126 len = pmtu;
127 qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
128 } else
129 qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
130 ohdr->u.aeth = ipath_compute_aeth(qp);
131 hwords++;
132 qp->s_ack_rdma_psn = e->psn;
133 bth2 = qp->s_ack_rdma_psn++ & IPATH_PSN_MASK;
134 } else {
135 /* COMPARE_SWAP or FETCH_ADD */
136 qp->s_cur_sge = NULL;
137 len = 0;
138 qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
139 ohdr->u.at.aeth = ipath_compute_aeth(qp);
140 ohdr->u.at.atomic_ack_eth[0] =
141 cpu_to_be32(e->atomic_data >> 32);
142 ohdr->u.at.atomic_ack_eth[1] =
143 cpu_to_be32(e->atomic_data);
144 hwords += sizeof(ohdr->u.at) / sizeof(u32);
145 bth2 = e->psn;
146 }
147 bth0 = qp->s_ack_state << 24;
148 break;
149
150 case OP(RDMA_READ_RESPONSE_FIRST):
151 qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
152 /* FALLTHROUGH */
153 case OP(RDMA_READ_RESPONSE_MIDDLE):
154 len = qp->s_ack_rdma_sge.sge.sge_length;
155 if (len > pmtu)
156 len = pmtu;
157 else {
158 ohdr->u.aeth = ipath_compute_aeth(qp);
159 hwords++;
160 qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
161 }
162 bth0 = qp->s_ack_state << 24;
163 bth2 = qp->s_ack_rdma_psn++ & IPATH_PSN_MASK;
164 break;
165
166 default:
167 normal:
168 /*
169 * Send a regular ACK.
170 * Set the s_ack_state so we wait until after sending
171 * the ACK before setting s_ack_state to ACKNOWLEDGE
172 * (see above).
173 */
174 qp->s_ack_state = OP(SEND_ONLY);
175 qp->s_flags &= ~IPATH_S_ACK_PENDING;
176 qp->s_cur_sge = NULL;
177 if (qp->s_nak_state)
178 ohdr->u.aeth =
179 cpu_to_be32((qp->r_msn & IPATH_MSN_MASK) |
180 (qp->s_nak_state <<
181 IPATH_AETH_CREDIT_SHIFT));
182 else
183 ohdr->u.aeth = ipath_compute_aeth(qp);
184 hwords++;
185 len = 0;
186 bth0 = OP(ACKNOWLEDGE) << 24;
187 bth2 = qp->s_ack_psn & IPATH_PSN_MASK;
188 }
189 qp->s_hdrwords = hwords;
190 qp->s_cur_size = len;
191 *bth0p = bth0;
192 *bth2p = bth2;
193 return 1;
194
195 bail:
196 return 0;
197 }
198
199 /**
200 * ipath_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
201 * @qp: a pointer to the QP
202 * @ohdr: a pointer to the IB header being constructed
203 * @pmtu: the path MTU
204 * @bth0p: pointer to the BTH opcode word
205 * @bth2p: pointer to the BTH PSN word
206 *
207 * Return 1 if constructed; otherwise, return 0.
208 * Note the QP s_lock must be held and interrupts disabled.
209 */
210 int ipath_make_rc_req(struct ipath_qp *qp,
211 struct ipath_other_headers *ohdr,
212 u32 pmtu, u32 *bth0p, u32 *bth2p)
213 {
214 struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
215 struct ipath_sge_state *ss;
216 struct ipath_swqe *wqe;
217 u32 hwords;
218 u32 len;
219 u32 bth0;
220 u32 bth2;
221 char newreq;
222
223 /* Sending responses has higher priority over sending requests. */
224 if ((qp->r_head_ack_queue != qp->s_tail_ack_queue ||
225 (qp->s_flags & IPATH_S_ACK_PENDING) ||
226 qp->s_ack_state != OP(ACKNOWLEDGE)) &&
227 ipath_make_rc_ack(qp, ohdr, pmtu, bth0p, bth2p))
228 goto done;
229
230 if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK) ||
231 qp->s_rnr_timeout || qp->s_wait_credit)
232 goto bail;
233
234 /* Limit the number of packets sent without an ACK. */
235 if (ipath_cmp24(qp->s_psn, qp->s_last_psn + IPATH_PSN_CREDIT) > 0) {
236 qp->s_wait_credit = 1;
237 dev->n_rc_stalls++;
238 goto bail;
239 }
240
241 /* header size in 32-bit words LRH+BTH = (8+12)/4. */
242 hwords = 5;
243 bth0 = 0;
244
245 /* Send a request. */
246 wqe = get_swqe_ptr(qp, qp->s_cur);
247 switch (qp->s_state) {
248 default:
249 /*
250 * Resend an old request or start a new one.
251 *
252 * We keep track of the current SWQE so that
253 * we don't reset the "furthest progress" state
254 * if we need to back up.
255 */
256 newreq = 0;
257 if (qp->s_cur == qp->s_tail) {
258 /* Check if send work queue is empty. */
259 if (qp->s_tail == qp->s_head)
260 goto bail;
261 /*
262 * If a fence is requested, wait for previous
263 * RDMA read and atomic operations to finish.
264 */
265 if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
266 qp->s_num_rd_atomic) {
267 qp->s_flags |= IPATH_S_FENCE_PENDING;
268 goto bail;
269 }
270 wqe->psn = qp->s_next_psn;
271 newreq = 1;
272 }
273 /*
274 * Note that we have to be careful not to modify the
275 * original work request since we may need to resend
276 * it.
277 */
278 len = wqe->length;
279 ss = &qp->s_sge;
280 bth2 = 0;
281 switch (wqe->wr.opcode) {
282 case IB_WR_SEND:
283 case IB_WR_SEND_WITH_IMM:
284 /* If no credit, return. */
285 if (qp->s_lsn != (u32) -1 &&
286 ipath_cmp24(wqe->ssn, qp->s_lsn + 1) > 0)
287 goto bail;
288 wqe->lpsn = wqe->psn;
289 if (len > pmtu) {
290 wqe->lpsn += (len - 1) / pmtu;
291 qp->s_state = OP(SEND_FIRST);
292 len = pmtu;
293 break;
294 }
295 if (wqe->wr.opcode == IB_WR_SEND)
296 qp->s_state = OP(SEND_ONLY);
297 else {
298 qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
299 /* Immediate data comes after the BTH */
300 ohdr->u.imm_data = wqe->wr.imm_data;
301 hwords += 1;
302 }
303 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
304 bth0 |= 1 << 23;
305 bth2 = 1 << 31; /* Request ACK. */
306 if (++qp->s_cur == qp->s_size)
307 qp->s_cur = 0;
308 break;
309
310 case IB_WR_RDMA_WRITE:
311 if (newreq && qp->s_lsn != (u32) -1)
312 qp->s_lsn++;
313 /* FALLTHROUGH */
314 case IB_WR_RDMA_WRITE_WITH_IMM:
315 /* If no credit, return. */
316 if (qp->s_lsn != (u32) -1 &&
317 ipath_cmp24(wqe->ssn, qp->s_lsn + 1) > 0)
318 goto bail;
319 ohdr->u.rc.reth.vaddr =
320 cpu_to_be64(wqe->wr.wr.rdma.remote_addr);
321 ohdr->u.rc.reth.rkey =
322 cpu_to_be32(wqe->wr.wr.rdma.rkey);
323 ohdr->u.rc.reth.length = cpu_to_be32(len);
324 hwords += sizeof(struct ib_reth) / sizeof(u32);
325 wqe->lpsn = wqe->psn;
326 if (len > pmtu) {
327 wqe->lpsn += (len - 1) / pmtu;
328 qp->s_state = OP(RDMA_WRITE_FIRST);
329 len = pmtu;
330 break;
331 }
332 if (wqe->wr.opcode == IB_WR_RDMA_WRITE)
333 qp->s_state = OP(RDMA_WRITE_ONLY);
334 else {
335 qp->s_state =
336 OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
337 /* Immediate data comes after RETH */
338 ohdr->u.rc.imm_data = wqe->wr.imm_data;
339 hwords += 1;
340 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
341 bth0 |= 1 << 23;
342 }
343 bth2 = 1 << 31; /* Request ACK. */
344 if (++qp->s_cur == qp->s_size)
345 qp->s_cur = 0;
346 break;
347
348 case IB_WR_RDMA_READ:
349 /*
350 * Don't allow more operations to be started
351 * than the QP limits allow.
352 */
353 if (newreq) {
354 if (qp->s_num_rd_atomic >=
355 qp->s_max_rd_atomic) {
356 qp->s_flags |= IPATH_S_RDMAR_PENDING;
357 goto bail;
358 }
359 qp->s_num_rd_atomic++;
360 if (qp->s_lsn != (u32) -1)
361 qp->s_lsn++;
362 /*
363 * Adjust s_next_psn to count the
364 * expected number of responses.
365 */
366 if (len > pmtu)
367 qp->s_next_psn += (len - 1) / pmtu;
368 wqe->lpsn = qp->s_next_psn++;
369 }
370 ohdr->u.rc.reth.vaddr =
371 cpu_to_be64(wqe->wr.wr.rdma.remote_addr);
372 ohdr->u.rc.reth.rkey =
373 cpu_to_be32(wqe->wr.wr.rdma.rkey);
374 ohdr->u.rc.reth.length = cpu_to_be32(len);
375 qp->s_state = OP(RDMA_READ_REQUEST);
376 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
377 ss = NULL;
378 len = 0;
379 if (++qp->s_cur == qp->s_size)
380 qp->s_cur = 0;
381 break;
382
383 case IB_WR_ATOMIC_CMP_AND_SWP:
384 case IB_WR_ATOMIC_FETCH_AND_ADD:
385 /*
386 * Don't allow more operations to be started
387 * than the QP limits allow.
388 */
389 if (newreq) {
390 if (qp->s_num_rd_atomic >=
391 qp->s_max_rd_atomic) {
392 qp->s_flags |= IPATH_S_RDMAR_PENDING;
393 goto bail;
394 }
395 qp->s_num_rd_atomic++;
396 if (qp->s_lsn != (u32) -1)
397 qp->s_lsn++;
398 wqe->lpsn = wqe->psn;
399 }
400 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP) {
401 qp->s_state = OP(COMPARE_SWAP);
402 ohdr->u.atomic_eth.swap_data = cpu_to_be64(
403 wqe->wr.wr.atomic.swap);
404 ohdr->u.atomic_eth.compare_data = cpu_to_be64(
405 wqe->wr.wr.atomic.compare_add);
406 } else {
407 qp->s_state = OP(FETCH_ADD);
408 ohdr->u.atomic_eth.swap_data = cpu_to_be64(
409 wqe->wr.wr.atomic.compare_add);
410 ohdr->u.atomic_eth.compare_data = 0;
411 }
412 ohdr->u.atomic_eth.vaddr[0] = cpu_to_be32(
413 wqe->wr.wr.atomic.remote_addr >> 32);
414 ohdr->u.atomic_eth.vaddr[1] = cpu_to_be32(
415 wqe->wr.wr.atomic.remote_addr);
416 ohdr->u.atomic_eth.rkey = cpu_to_be32(
417 wqe->wr.wr.atomic.rkey);
418 hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
419 ss = NULL;
420 len = 0;
421 if (++qp->s_cur == qp->s_size)
422 qp->s_cur = 0;
423 break;
424
425 default:
426 goto bail;
427 }
428 qp->s_sge.sge = wqe->sg_list[0];
429 qp->s_sge.sg_list = wqe->sg_list + 1;
430 qp->s_sge.num_sge = wqe->wr.num_sge;
431 qp->s_len = wqe->length;
432 if (newreq) {
433 qp->s_tail++;
434 if (qp->s_tail >= qp->s_size)
435 qp->s_tail = 0;
436 }
437 bth2 |= qp->s_psn & IPATH_PSN_MASK;
438 if (wqe->wr.opcode == IB_WR_RDMA_READ)
439 qp->s_psn = wqe->lpsn + 1;
440 else {
441 qp->s_psn++;
442 if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
443 qp->s_next_psn = qp->s_psn;
444 }
445 /*
446 * Put the QP on the pending list so lost ACKs will cause
447 * a retry. More than one request can be pending so the
448 * QP may already be on the dev->pending list.
449 */
450 spin_lock(&dev->pending_lock);
451 if (list_empty(&qp->timerwait))
452 list_add_tail(&qp->timerwait,
453 &dev->pending[dev->pending_index]);
454 spin_unlock(&dev->pending_lock);
455 break;
456
457 case OP(RDMA_READ_RESPONSE_FIRST):
458 /*
459 * This case can only happen if a send is restarted.
460 * See ipath_restart_rc().
461 */
462 ipath_init_restart(qp, wqe);
463 /* FALLTHROUGH */
464 case OP(SEND_FIRST):
465 qp->s_state = OP(SEND_MIDDLE);
466 /* FALLTHROUGH */
467 case OP(SEND_MIDDLE):
468 bth2 = qp->s_psn++ & IPATH_PSN_MASK;
469 if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
470 qp->s_next_psn = qp->s_psn;
471 ss = &qp->s_sge;
472 len = qp->s_len;
473 if (len > pmtu) {
474 len = pmtu;
475 break;
476 }
477 if (wqe->wr.opcode == IB_WR_SEND)
478 qp->s_state = OP(SEND_LAST);
479 else {
480 qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
481 /* Immediate data comes after the BTH */
482 ohdr->u.imm_data = wqe->wr.imm_data;
483 hwords += 1;
484 }
485 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
486 bth0 |= 1 << 23;
487 bth2 |= 1 << 31; /* Request ACK. */
488 qp->s_cur++;
489 if (qp->s_cur >= qp->s_size)
490 qp->s_cur = 0;
491 break;
492
493 case OP(RDMA_READ_RESPONSE_LAST):
494 /*
495 * This case can only happen if a RDMA write is restarted.
496 * See ipath_restart_rc().
497 */
498 ipath_init_restart(qp, wqe);
499 /* FALLTHROUGH */
500 case OP(RDMA_WRITE_FIRST):
501 qp->s_state = OP(RDMA_WRITE_MIDDLE);
502 /* FALLTHROUGH */
503 case OP(RDMA_WRITE_MIDDLE):
504 bth2 = qp->s_psn++ & IPATH_PSN_MASK;
505 if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
506 qp->s_next_psn = qp->s_psn;
507 ss = &qp->s_sge;
508 len = qp->s_len;
509 if (len > pmtu) {
510 len = pmtu;
511 break;
512 }
513 if (wqe->wr.opcode == IB_WR_RDMA_WRITE)
514 qp->s_state = OP(RDMA_WRITE_LAST);
515 else {
516 qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
517 /* Immediate data comes after the BTH */
518 ohdr->u.imm_data = wqe->wr.imm_data;
519 hwords += 1;
520 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
521 bth0 |= 1 << 23;
522 }
523 bth2 |= 1 << 31; /* Request ACK. */
524 qp->s_cur++;
525 if (qp->s_cur >= qp->s_size)
526 qp->s_cur = 0;
527 break;
528
529 case OP(RDMA_READ_RESPONSE_MIDDLE):
530 /*
531 * This case can only happen if a RDMA read is restarted.
532 * See ipath_restart_rc().
533 */
534 ipath_init_restart(qp, wqe);
535 len = ((qp->s_psn - wqe->psn) & IPATH_PSN_MASK) * pmtu;
536 ohdr->u.rc.reth.vaddr =
537 cpu_to_be64(wqe->wr.wr.rdma.remote_addr + len);
538 ohdr->u.rc.reth.rkey =
539 cpu_to_be32(wqe->wr.wr.rdma.rkey);
540 ohdr->u.rc.reth.length = cpu_to_be32(qp->s_len);
541 qp->s_state = OP(RDMA_READ_REQUEST);
542 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
543 bth2 = qp->s_psn++ & IPATH_PSN_MASK;
544 if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
545 qp->s_next_psn = qp->s_psn;
546 ss = NULL;
547 len = 0;
548 qp->s_cur++;
549 if (qp->s_cur == qp->s_size)
550 qp->s_cur = 0;
551 break;
552 }
553 if (ipath_cmp24(qp->s_psn, qp->s_last_psn + IPATH_PSN_CREDIT - 1) >= 0)
554 bth2 |= 1 << 31; /* Request ACK. */
555 qp->s_len -= len;
556 qp->s_hdrwords = hwords;
557 qp->s_cur_sge = ss;
558 qp->s_cur_size = len;
559 *bth0p = bth0 | (qp->s_state << 24);
560 *bth2p = bth2;
561 done:
562 return 1;
563
564 bail:
565 return 0;
566 }
567
568 /**
569 * send_rc_ack - Construct an ACK packet and send it
570 * @qp: a pointer to the QP
571 *
572 * This is called from ipath_rc_rcv() and only uses the receive
573 * side QP state.
574 * Note that RDMA reads and atomics are handled in the
575 * send side QP state and tasklet.
576 */
577 static void send_rc_ack(struct ipath_qp *qp)
578 {
579 struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
580 u16 lrh0;
581 u32 bth0;
582 u32 hwords;
583 struct ipath_ib_header hdr;
584 struct ipath_other_headers *ohdr;
585 unsigned long flags;
586
587 /* Don't send ACK or NAK if a RDMA read or atomic is pending. */
588 if (qp->r_head_ack_queue != qp->s_tail_ack_queue ||
589 (qp->s_flags & IPATH_S_ACK_PENDING) ||
590 qp->s_ack_state != OP(ACKNOWLEDGE))
591 goto queue_ack;
592
593 /* Construct the header. */
594 ohdr = &hdr.u.oth;
595 lrh0 = IPATH_LRH_BTH;
596 /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4. */
597 hwords = 6;
598 if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
599 hwords += ipath_make_grh(dev, &hdr.u.l.grh,
600 &qp->remote_ah_attr.grh,
601 hwords, 0);
602 ohdr = &hdr.u.l.oth;
603 lrh0 = IPATH_LRH_GRH;
604 }
605 /* read pkey_index w/o lock (its atomic) */
606 bth0 = ipath_get_pkey(dev->dd, qp->s_pkey_index) |
607 OP(ACKNOWLEDGE) << 24;
608 if (qp->r_nak_state)
609 ohdr->u.aeth = cpu_to_be32((qp->r_msn & IPATH_MSN_MASK) |
610 (qp->r_nak_state <<
611 IPATH_AETH_CREDIT_SHIFT));
612 else
613 ohdr->u.aeth = ipath_compute_aeth(qp);
614 lrh0 |= qp->remote_ah_attr.sl << 4;
615 hdr.lrh[0] = cpu_to_be16(lrh0);
616 hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
617 hdr.lrh[2] = cpu_to_be16(hwords + SIZE_OF_CRC);
618 hdr.lrh[3] = cpu_to_be16(dev->dd->ipath_lid);
619 ohdr->bth[0] = cpu_to_be32(bth0);
620 ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
621 ohdr->bth[2] = cpu_to_be32(qp->r_ack_psn & IPATH_PSN_MASK);
622
623 /*
624 * If we can send the ACK, clear the ACK state.
625 */
626 if (ipath_verbs_send(dev->dd, hwords, (u32 *) &hdr, 0, NULL) == 0) {
627 dev->n_unicast_xmit++;
628 goto done;
629 }
630
631 /*
632 * We are out of PIO buffers at the moment.
633 * Pass responsibility for sending the ACK to the
634 * send tasklet so that when a PIO buffer becomes
635 * available, the ACK is sent ahead of other outgoing
636 * packets.
637 */
638 dev->n_rc_qacks++;
639
640 queue_ack:
641 spin_lock_irqsave(&qp->s_lock, flags);
642 qp->s_flags |= IPATH_S_ACK_PENDING;
643 qp->s_nak_state = qp->r_nak_state;
644 qp->s_ack_psn = qp->r_ack_psn;
645 spin_unlock_irqrestore(&qp->s_lock, flags);
646
647 /* Call ipath_do_rc_send() in another thread. */
648 tasklet_hi_schedule(&qp->s_task);
649
650 done:
651 return;
652 }
653
654 /**
655 * reset_psn - reset the QP state to send starting from PSN
656 * @qp: the QP
657 * @psn: the packet sequence number to restart at
658 *
659 * This is called from ipath_rc_rcv() to process an incoming RC ACK
660 * for the given QP.
661 * Called at interrupt level with the QP s_lock held.
662 */
663 static void reset_psn(struct ipath_qp *qp, u32 psn)
664 {
665 u32 n = qp->s_last;
666 struct ipath_swqe *wqe = get_swqe_ptr(qp, n);
667 u32 opcode;
668
669 qp->s_cur = n;
670
671 /*
672 * If we are starting the request from the beginning,
673 * let the normal send code handle initialization.
674 */
675 if (ipath_cmp24(psn, wqe->psn) <= 0) {
676 qp->s_state = OP(SEND_LAST);
677 goto done;
678 }
679
680 /* Find the work request opcode corresponding to the given PSN. */
681 opcode = wqe->wr.opcode;
682 for (;;) {
683 int diff;
684
685 if (++n == qp->s_size)
686 n = 0;
687 if (n == qp->s_tail)
688 break;
689 wqe = get_swqe_ptr(qp, n);
690 diff = ipath_cmp24(psn, wqe->psn);
691 if (diff < 0)
692 break;
693 qp->s_cur = n;
694 /*
695 * If we are starting the request from the beginning,
696 * let the normal send code handle initialization.
697 */
698 if (diff == 0) {
699 qp->s_state = OP(SEND_LAST);
700 goto done;
701 }
702 opcode = wqe->wr.opcode;
703 }
704
705 /*
706 * Set the state to restart in the middle of a request.
707 * Don't change the s_sge, s_cur_sge, or s_cur_size.
708 * See ipath_do_rc_send().
709 */
710 switch (opcode) {
711 case IB_WR_SEND:
712 case IB_WR_SEND_WITH_IMM:
713 qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
714 break;
715
716 case IB_WR_RDMA_WRITE:
717 case IB_WR_RDMA_WRITE_WITH_IMM:
718 qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
719 break;
720
721 case IB_WR_RDMA_READ:
722 qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
723 break;
724
725 default:
726 /*
727 * This case shouldn't happen since its only
728 * one PSN per req.
729 */
730 qp->s_state = OP(SEND_LAST);
731 }
732 done:
733 qp->s_psn = psn;
734 }
735
736 /**
737 * ipath_restart_rc - back up requester to resend the last un-ACKed request
738 * @qp: the QP to restart
739 * @psn: packet sequence number for the request
740 * @wc: the work completion request
741 *
742 * The QP s_lock should be held and interrupts disabled.
743 */
744 void ipath_restart_rc(struct ipath_qp *qp, u32 psn, struct ib_wc *wc)
745 {
746 struct ipath_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
747 struct ipath_ibdev *dev;
748
749 if (qp->s_retry == 0) {
750 wc->wr_id = wqe->wr.wr_id;
751 wc->status = IB_WC_RETRY_EXC_ERR;
752 wc->opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
753 wc->vendor_err = 0;
754 wc->byte_len = 0;
755 wc->qp = &qp->ibqp;
756 wc->src_qp = qp->remote_qpn;
757 wc->pkey_index = 0;
758 wc->slid = qp->remote_ah_attr.dlid;
759 wc->sl = qp->remote_ah_attr.sl;
760 wc->dlid_path_bits = 0;
761 wc->port_num = 0;
762 ipath_sqerror_qp(qp, wc);
763 goto bail;
764 }
765 qp->s_retry--;
766
767 /*
768 * Remove the QP from the timeout queue.
769 * Note: it may already have been removed by ipath_ib_timer().
770 */
771 dev = to_idev(qp->ibqp.device);
772 spin_lock(&dev->pending_lock);
773 if (!list_empty(&qp->timerwait))
774 list_del_init(&qp->timerwait);
775 spin_unlock(&dev->pending_lock);
776
777 if (wqe->wr.opcode == IB_WR_RDMA_READ)
778 dev->n_rc_resends++;
779 else
780 dev->n_rc_resends += (qp->s_psn - psn) & IPATH_PSN_MASK;
781
782 reset_psn(qp, psn);
783 tasklet_hi_schedule(&qp->s_task);
784
785 bail:
786 return;
787 }
788
789 static inline void update_last_psn(struct ipath_qp *qp, u32 psn)
790 {
791 if (qp->s_wait_credit) {
792 qp->s_wait_credit = 0;
793 tasklet_hi_schedule(&qp->s_task);
794 }
795 qp->s_last_psn = psn;
796 }
797
798 /**
799 * do_rc_ack - process an incoming RC ACK
800 * @qp: the QP the ACK came in on
801 * @psn: the packet sequence number of the ACK
802 * @opcode: the opcode of the request that resulted in the ACK
803 *
804 * This is called from ipath_rc_rcv_resp() to process an incoming RC ACK
805 * for the given QP.
806 * Called at interrupt level with the QP s_lock held and interrupts disabled.
807 * Returns 1 if OK, 0 if current operation should be aborted (NAK).
808 */
809 static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode)
810 {
811 struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
812 struct ib_wc wc;
813 struct ipath_swqe *wqe;
814 int ret = 0;
815 u32 ack_psn;
816
817 /*
818 * Remove the QP from the timeout queue (or RNR timeout queue).
819 * If ipath_ib_timer() has already removed it,
820 * it's OK since we hold the QP s_lock and ipath_restart_rc()
821 * just won't find anything to restart if we ACK everything.
822 */
823 spin_lock(&dev->pending_lock);
824 if (!list_empty(&qp->timerwait))
825 list_del_init(&qp->timerwait);
826 spin_unlock(&dev->pending_lock);
827
828 /*
829 * Note that NAKs implicitly ACK outstanding SEND and RDMA write
830 * requests and implicitly NAK RDMA read and atomic requests issued
831 * before the NAK'ed request. The MSN won't include the NAK'ed
832 * request but will include an ACK'ed request(s).
833 */
834 ack_psn = psn;
835 if (aeth >> 29)
836 ack_psn--;
837 wqe = get_swqe_ptr(qp, qp->s_last);
838
839 /*
840 * The MSN might be for a later WQE than the PSN indicates so
841 * only complete WQEs that the PSN finishes.
842 */
843 while (ipath_cmp24(ack_psn, wqe->lpsn) >= 0) {
844 /*
845 * If this request is a RDMA read or atomic, and the ACK is
846 * for a later operation, this ACK NAKs the RDMA read or
847 * atomic. In other words, only a RDMA_READ_LAST or ONLY
848 * can ACK a RDMA read and likewise for atomic ops. Note
849 * that the NAK case can only happen if relaxed ordering is
850 * used and requests are sent after an RDMA read or atomic
851 * is sent but before the response is received.
852 */
853 if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
854 (opcode != OP(RDMA_READ_RESPONSE_LAST) ||
855 ipath_cmp24(ack_psn, wqe->lpsn) != 0)) ||
856 ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
857 wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
858 (opcode != OP(ATOMIC_ACKNOWLEDGE) ||
859 ipath_cmp24(wqe->psn, psn) != 0))) {
860 /*
861 * The last valid PSN seen is the previous
862 * request's.
863 */
864 update_last_psn(qp, wqe->psn - 1);
865 /* Retry this request. */
866 ipath_restart_rc(qp, wqe->psn, &wc);
867 /*
868 * No need to process the ACK/NAK since we are
869 * restarting an earlier request.
870 */
871 goto bail;
872 }
873 if (qp->s_num_rd_atomic &&
874 (wqe->wr.opcode == IB_WR_RDMA_READ ||
875 wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
876 wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
877 qp->s_num_rd_atomic--;
878 /* Restart sending task if fence is complete */
879 if ((qp->s_flags & IPATH_S_FENCE_PENDING) &&
880 !qp->s_num_rd_atomic) {
881 qp->s_flags &= ~IPATH_S_FENCE_PENDING;
882 tasklet_hi_schedule(&qp->s_task);
883 } else if (qp->s_flags & IPATH_S_RDMAR_PENDING) {
884 qp->s_flags &= ~IPATH_S_RDMAR_PENDING;
885 tasklet_hi_schedule(&qp->s_task);
886 }
887 }
888 /* Post a send completion queue entry if requested. */
889 if (!(qp->s_flags & IPATH_S_SIGNAL_REQ_WR) ||
890 (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
891 wc.wr_id = wqe->wr.wr_id;
892 wc.status = IB_WC_SUCCESS;
893 wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
894 wc.vendor_err = 0;
895 wc.byte_len = wqe->length;
896 wc.imm_data = 0;
897 wc.qp = &qp->ibqp;
898 wc.src_qp = qp->remote_qpn;
899 wc.wc_flags = 0;
900 wc.pkey_index = 0;
901 wc.slid = qp->remote_ah_attr.dlid;
902 wc.sl = qp->remote_ah_attr.sl;
903 wc.dlid_path_bits = 0;
904 wc.port_num = 0;
905 ipath_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 0);
906 }
907 qp->s_retry = qp->s_retry_cnt;
908 /*
909 * If we are completing a request which is in the process of
910 * being resent, we can stop resending it since we know the
911 * responder has already seen it.
912 */
913 if (qp->s_last == qp->s_cur) {
914 if (++qp->s_cur >= qp->s_size)
915 qp->s_cur = 0;
916 qp->s_last = qp->s_cur;
917 if (qp->s_last == qp->s_tail)
918 break;
919 wqe = get_swqe_ptr(qp, qp->s_cur);
920 qp->s_state = OP(SEND_LAST);
921 qp->s_psn = wqe->psn;
922 } else {
923 if (++qp->s_last >= qp->s_size)
924 qp->s_last = 0;
925 if (qp->s_last == qp->s_tail)
926 break;
927 wqe = get_swqe_ptr(qp, qp->s_last);
928 }
929 }
930
931 switch (aeth >> 29) {
932 case 0: /* ACK */
933 dev->n_rc_acks++;
934 /* If this is a partial ACK, reset the retransmit timer. */
935 if (qp->s_last != qp->s_tail) {
936 spin_lock(&dev->pending_lock);
937 list_add_tail(&qp->timerwait,
938 &dev->pending[dev->pending_index]);
939 spin_unlock(&dev->pending_lock);
940 /*
941 * If we get a partial ACK for a resent operation,
942 * we can stop resending the earlier packets and
943 * continue with the next packet the receiver wants.
944 */
945 if (ipath_cmp24(qp->s_psn, psn) <= 0) {
946 reset_psn(qp, psn + 1);
947 tasklet_hi_schedule(&qp->s_task);
948 }
949 } else if (ipath_cmp24(qp->s_psn, psn) <= 0) {
950 qp->s_state = OP(SEND_LAST);
951 qp->s_psn = psn + 1;
952 }
953 ipath_get_credit(qp, aeth);
954 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
955 qp->s_retry = qp->s_retry_cnt;
956 update_last_psn(qp, psn);
957 ret = 1;
958 goto bail;
959
960 case 1: /* RNR NAK */
961 dev->n_rnr_naks++;
962 if (qp->s_last == qp->s_tail)
963 goto bail;
964 if (qp->s_rnr_retry == 0) {
965 wc.status = IB_WC_RNR_RETRY_EXC_ERR;
966 goto class_b;
967 }
968 if (qp->s_rnr_retry_cnt < 7)
969 qp->s_rnr_retry--;
970
971 /* The last valid PSN is the previous PSN. */
972 update_last_psn(qp, psn - 1);
973
974 if (wqe->wr.opcode == IB_WR_RDMA_READ)
975 dev->n_rc_resends++;
976 else
977 dev->n_rc_resends +=
978 (qp->s_psn - psn) & IPATH_PSN_MASK;
979
980 reset_psn(qp, psn);
981
982 qp->s_rnr_timeout =
983 ib_ipath_rnr_table[(aeth >> IPATH_AETH_CREDIT_SHIFT) &
984 IPATH_AETH_CREDIT_MASK];
985 ipath_insert_rnr_queue(qp);
986 goto bail;
987
988 case 3: /* NAK */
989 if (qp->s_last == qp->s_tail)
990 goto bail;
991 /* The last valid PSN is the previous PSN. */
992 update_last_psn(qp, psn - 1);
993 switch ((aeth >> IPATH_AETH_CREDIT_SHIFT) &
994 IPATH_AETH_CREDIT_MASK) {
995 case 0: /* PSN sequence error */
996 dev->n_seq_naks++;
997 /*
998 * Back up to the responder's expected PSN.
999 * Note that we might get a NAK in the middle of an
1000 * RDMA READ response which terminates the RDMA
1001 * READ.
1002 */
1003 ipath_restart_rc(qp, psn, &wc);
1004 break;
1005
1006 case 1: /* Invalid Request */
1007 wc.status = IB_WC_REM_INV_REQ_ERR;
1008 dev->n_other_naks++;
1009 goto class_b;
1010
1011 case 2: /* Remote Access Error */
1012 wc.status = IB_WC_REM_ACCESS_ERR;
1013 dev->n_other_naks++;
1014 goto class_b;
1015
1016 case 3: /* Remote Operation Error */
1017 wc.status = IB_WC_REM_OP_ERR;
1018 dev->n_other_naks++;
1019 class_b:
1020 wc.wr_id = wqe->wr.wr_id;
1021 wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
1022 wc.vendor_err = 0;
1023 wc.byte_len = 0;
1024 wc.qp = &qp->ibqp;
1025 wc.src_qp = qp->remote_qpn;
1026 wc.pkey_index = 0;
1027 wc.slid = qp->remote_ah_attr.dlid;
1028 wc.sl = qp->remote_ah_attr.sl;
1029 wc.dlid_path_bits = 0;
1030 wc.port_num = 0;
1031 ipath_sqerror_qp(qp, &wc);
1032 break;
1033
1034 default:
1035 /* Ignore other reserved NAK error codes */
1036 goto reserved;
1037 }
1038 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1039 goto bail;
1040
1041 default: /* 2: reserved */
1042 reserved:
1043 /* Ignore reserved NAK codes. */
1044 goto bail;
1045 }
1046
1047 bail:
1048 return ret;
1049 }
1050
1051 /**
1052 * ipath_rc_rcv_resp - process an incoming RC response packet
1053 * @dev: the device this packet came in on
1054 * @ohdr: the other headers for this packet
1055 * @data: the packet data
1056 * @tlen: the packet length
1057 * @qp: the QP for this packet
1058 * @opcode: the opcode for this packet
1059 * @psn: the packet sequence number for this packet
1060 * @hdrsize: the header length
1061 * @pmtu: the path MTU
1062 * @header_in_data: true if part of the header data is in the data buffer
1063 *
1064 * This is called from ipath_rc_rcv() to process an incoming RC response
1065 * packet for the given QP.
1066 * Called at interrupt level.
1067 */
1068 static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
1069 struct ipath_other_headers *ohdr,
1070 void *data, u32 tlen,
1071 struct ipath_qp *qp,
1072 u32 opcode,
1073 u32 psn, u32 hdrsize, u32 pmtu,
1074 int header_in_data)
1075 {
1076 struct ipath_swqe *wqe;
1077 unsigned long flags;
1078 struct ib_wc wc;
1079 int diff;
1080 u32 pad;
1081 u32 aeth;
1082
1083 spin_lock_irqsave(&qp->s_lock, flags);
1084
1085 /* Ignore invalid responses. */
1086 if (ipath_cmp24(psn, qp->s_next_psn) >= 0)
1087 goto ack_done;
1088
1089 /* Ignore duplicate responses. */
1090 diff = ipath_cmp24(psn, qp->s_last_psn);
1091 if (unlikely(diff <= 0)) {
1092 /* Update credits for "ghost" ACKs */
1093 if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
1094 if (!header_in_data)
1095 aeth = be32_to_cpu(ohdr->u.aeth);
1096 else {
1097 aeth = be32_to_cpu(((__be32 *) data)[0]);
1098 data += sizeof(__be32);
1099 }
1100 if ((aeth >> 29) == 0)
1101 ipath_get_credit(qp, aeth);
1102 }
1103 goto ack_done;
1104 }
1105
1106 if (unlikely(qp->s_last == qp->s_tail))
1107 goto ack_done;
1108 wqe = get_swqe_ptr(qp, qp->s_last);
1109
1110 switch (opcode) {
1111 case OP(ACKNOWLEDGE):
1112 case OP(ATOMIC_ACKNOWLEDGE):
1113 case OP(RDMA_READ_RESPONSE_FIRST):
1114 if (!header_in_data)
1115 aeth = be32_to_cpu(ohdr->u.aeth);
1116 else {
1117 aeth = be32_to_cpu(((__be32 *) data)[0]);
1118 data += sizeof(__be32);
1119 }
1120 if (opcode == OP(ATOMIC_ACKNOWLEDGE)) {
1121 u64 val;
1122
1123 if (!header_in_data) {
1124 __be32 *p = ohdr->u.at.atomic_ack_eth;
1125
1126 val = ((u64) be32_to_cpu(p[0]) << 32) |
1127 be32_to_cpu(p[1]);
1128 } else
1129 val = be64_to_cpu(((__be64 *) data)[0]);
1130 *(u64 *) wqe->sg_list[0].vaddr = val;
1131 }
1132 if (!do_rc_ack(qp, aeth, psn, opcode) ||
1133 opcode != OP(RDMA_READ_RESPONSE_FIRST))
1134 goto ack_done;
1135 hdrsize += 4;
1136 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1137 goto ack_op_err;
1138 /*
1139 * If this is a response to a resent RDMA read, we
1140 * have to be careful to copy the data to the right
1141 * location.
1142 */
1143 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1144 wqe, psn, pmtu);
1145 goto read_middle;
1146
1147 case OP(RDMA_READ_RESPONSE_MIDDLE):
1148 /* no AETH, no ACK */
1149 if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
1150 dev->n_rdma_seq++;
1151 ipath_restart_rc(qp, qp->s_last_psn + 1, &wc);
1152 goto ack_done;
1153 }
1154 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1155 goto ack_op_err;
1156 read_middle:
1157 if (unlikely(tlen != (hdrsize + pmtu + 4)))
1158 goto ack_len_err;
1159 if (unlikely(pmtu >= qp->s_rdma_read_len))
1160 goto ack_len_err;
1161
1162 /* We got a response so update the timeout. */
1163 spin_lock(&dev->pending_lock);
1164 if (qp->s_rnr_timeout == 0 && !list_empty(&qp->timerwait))
1165 list_move_tail(&qp->timerwait,
1166 &dev->pending[dev->pending_index]);
1167 spin_unlock(&dev->pending_lock);
1168 /*
1169 * Update the RDMA receive state but do the copy w/o
1170 * holding the locks and blocking interrupts.
1171 */
1172 qp->s_rdma_read_len -= pmtu;
1173 update_last_psn(qp, psn);
1174 spin_unlock_irqrestore(&qp->s_lock, flags);
1175 ipath_copy_sge(&qp->s_rdma_read_sge, data, pmtu);
1176 goto bail;
1177
1178 case OP(RDMA_READ_RESPONSE_ONLY):
1179 if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
1180 dev->n_rdma_seq++;
1181 ipath_restart_rc(qp, qp->s_last_psn + 1, &wc);
1182 goto ack_done;
1183 }
1184 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1185 goto ack_op_err;
1186 /* Get the number of bytes the message was padded by. */
1187 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1188 /*
1189 * Check that the data size is >= 0 && <= pmtu.
1190 * Remember to account for the AETH header (4) and
1191 * ICRC (4).
1192 */
1193 if (unlikely(tlen < (hdrsize + pad + 8)))
1194 goto ack_len_err;
1195 /*
1196 * If this is a response to a resent RDMA read, we
1197 * have to be careful to copy the data to the right
1198 * location.
1199 */
1200 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1201 wqe, psn, pmtu);
1202 goto read_last;
1203
1204 case OP(RDMA_READ_RESPONSE_LAST):
1205 /* ACKs READ req. */
1206 if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
1207 dev->n_rdma_seq++;
1208 ipath_restart_rc(qp, qp->s_last_psn + 1, &wc);
1209 goto ack_done;
1210 }
1211 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1212 goto ack_op_err;
1213 /* Get the number of bytes the message was padded by. */
1214 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1215 /*
1216 * Check that the data size is >= 1 && <= pmtu.
1217 * Remember to account for the AETH header (4) and
1218 * ICRC (4).
1219 */
1220 if (unlikely(tlen <= (hdrsize + pad + 8)))
1221 goto ack_len_err;
1222 read_last:
1223 tlen -= hdrsize + pad + 8;
1224 if (unlikely(tlen != qp->s_rdma_read_len))
1225 goto ack_len_err;
1226 if (!header_in_data)
1227 aeth = be32_to_cpu(ohdr->u.aeth);
1228 else {
1229 aeth = be32_to_cpu(((__be32 *) data)[0]);
1230 data += sizeof(__be32);
1231 }
1232 ipath_copy_sge(&qp->s_rdma_read_sge, data, tlen);
1233 (void) do_rc_ack(qp, aeth, psn, OP(RDMA_READ_RESPONSE_LAST));
1234 goto ack_done;
1235 }
1236
1237 ack_done:
1238 spin_unlock_irqrestore(&qp->s_lock, flags);
1239 goto bail;
1240
1241 ack_op_err:
1242 wc.status = IB_WC_LOC_QP_OP_ERR;
1243 goto ack_err;
1244
1245 ack_len_err:
1246 wc.status = IB_WC_LOC_LEN_ERR;
1247 ack_err:
1248 wc.wr_id = wqe->wr.wr_id;
1249 wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
1250 wc.vendor_err = 0;
1251 wc.byte_len = 0;
1252 wc.imm_data = 0;
1253 wc.qp = &qp->ibqp;
1254 wc.src_qp = qp->remote_qpn;
1255 wc.wc_flags = 0;
1256 wc.pkey_index = 0;
1257 wc.slid = qp->remote_ah_attr.dlid;
1258 wc.sl = qp->remote_ah_attr.sl;
1259 wc.dlid_path_bits = 0;
1260 wc.port_num = 0;
1261 ipath_sqerror_qp(qp, &wc);
1262 spin_unlock_irqrestore(&qp->s_lock, flags);
1263 bail:
1264 return;
1265 }
1266
1267 /**
1268 * ipath_rc_rcv_error - process an incoming duplicate or error RC packet
1269 * @dev: the device this packet came in on
1270 * @ohdr: the other headers for this packet
1271 * @data: the packet data
1272 * @qp: the QP for this packet
1273 * @opcode: the opcode for this packet
1274 * @psn: the packet sequence number for this packet
1275 * @diff: the difference between the PSN and the expected PSN
1276 * @header_in_data: true if part of the header data is in the data buffer
1277 *
1278 * This is called from ipath_rc_rcv() to process an unexpected
1279 * incoming RC packet for the given QP.
1280 * Called at interrupt level.
1281 * Return 1 if no more processing is needed; otherwise return 0 to
1282 * schedule a response to be sent.
1283 */
1284 static inline int ipath_rc_rcv_error(struct ipath_ibdev *dev,
1285 struct ipath_other_headers *ohdr,
1286 void *data,
1287 struct ipath_qp *qp,
1288 u32 opcode,
1289 u32 psn,
1290 int diff,
1291 int header_in_data)
1292 {
1293 struct ipath_ack_entry *e;
1294 u8 i, prev;
1295 int old_req;
1296 unsigned long flags;
1297
1298 if (diff > 0) {
1299 /*
1300 * Packet sequence error.
1301 * A NAK will ACK earlier sends and RDMA writes.
1302 * Don't queue the NAK if we already sent one.
1303 */
1304 if (!qp->r_nak_state) {
1305 qp->r_nak_state = IB_NAK_PSN_ERROR;
1306 /* Use the expected PSN. */
1307 qp->r_ack_psn = qp->r_psn;
1308 goto send_ack;
1309 }
1310 goto done;
1311 }
1312
1313 /*
1314 * Handle a duplicate request. Don't re-execute SEND, RDMA
1315 * write or atomic op. Don't NAK errors, just silently drop
1316 * the duplicate request. Note that r_sge, r_len, and
1317 * r_rcv_len may be in use so don't modify them.
1318 *
1319 * We are supposed to ACK the earliest duplicate PSN but we
1320 * can coalesce an outstanding duplicate ACK. We have to
1321 * send the earliest so that RDMA reads can be restarted at
1322 * the requester's expected PSN.
1323 *
1324 * First, find where this duplicate PSN falls within the
1325 * ACKs previously sent.
1326 */
1327 psn &= IPATH_PSN_MASK;
1328 e = NULL;
1329 old_req = 1;
1330 spin_lock_irqsave(&qp->s_lock, flags);
1331 for (i = qp->r_head_ack_queue; ; i = prev) {
1332 if (i == qp->s_tail_ack_queue)
1333 old_req = 0;
1334 if (i)
1335 prev = i - 1;
1336 else
1337 prev = IPATH_MAX_RDMA_ATOMIC;
1338 if (prev == qp->r_head_ack_queue) {
1339 e = NULL;
1340 break;
1341 }
1342 e = &qp->s_ack_queue[prev];
1343 if (!e->opcode) {
1344 e = NULL;
1345 break;
1346 }
1347 if (ipath_cmp24(psn, e->psn) >= 0)
1348 break;
1349 }
1350 switch (opcode) {
1351 case OP(RDMA_READ_REQUEST): {
1352 struct ib_reth *reth;
1353 u32 offset;
1354 u32 len;
1355
1356 /*
1357 * If we didn't find the RDMA read request in the ack queue,
1358 * or the send tasklet is already backed up to send an
1359 * earlier entry, we can ignore this request.
1360 */
1361 if (!e || e->opcode != OP(RDMA_READ_REQUEST) || old_req)
1362 goto unlock_done;
1363 /* RETH comes after BTH */
1364 if (!header_in_data)
1365 reth = &ohdr->u.rc.reth;
1366 else {
1367 reth = (struct ib_reth *)data;
1368 data += sizeof(*reth);
1369 }
1370 /*
1371 * Address range must be a subset of the original
1372 * request and start on pmtu boundaries.
1373 * We reuse the old ack_queue slot since the requester
1374 * should not back up and request an earlier PSN for the
1375 * same request.
1376 */
1377 offset = ((psn - e->psn) & IPATH_PSN_MASK) *
1378 ib_mtu_enum_to_int(qp->path_mtu);
1379 len = be32_to_cpu(reth->length);
1380 if (unlikely(offset + len > e->rdma_sge.sge.sge_length))
1381 goto unlock_done;
1382 if (len != 0) {
1383 u32 rkey = be32_to_cpu(reth->rkey);
1384 u64 vaddr = be64_to_cpu(reth->vaddr);
1385 int ok;
1386
1387 ok = ipath_rkey_ok(qp, &e->rdma_sge,
1388 len, vaddr, rkey,
1389 IB_ACCESS_REMOTE_READ);
1390 if (unlikely(!ok))
1391 goto unlock_done;
1392 } else {
1393 e->rdma_sge.sg_list = NULL;
1394 e->rdma_sge.num_sge = 0;
1395 e->rdma_sge.sge.mr = NULL;
1396 e->rdma_sge.sge.vaddr = NULL;
1397 e->rdma_sge.sge.length = 0;
1398 e->rdma_sge.sge.sge_length = 0;
1399 }
1400 e->psn = psn;
1401 qp->s_ack_state = OP(ACKNOWLEDGE);
1402 qp->s_tail_ack_queue = prev;
1403 break;
1404 }
1405
1406 case OP(COMPARE_SWAP):
1407 case OP(FETCH_ADD): {
1408 /*
1409 * If we didn't find the atomic request in the ack queue
1410 * or the send tasklet is already backed up to send an
1411 * earlier entry, we can ignore this request.
1412 */
1413 if (!e || e->opcode != (u8) opcode || old_req)
1414 goto unlock_done;
1415 qp->s_ack_state = OP(ACKNOWLEDGE);
1416 qp->s_tail_ack_queue = prev;
1417 break;
1418 }
1419
1420 default:
1421 if (old_req)
1422 goto unlock_done;
1423 /*
1424 * Resend the most recent ACK if this request is
1425 * after all the previous RDMA reads and atomics.
1426 */
1427 if (i == qp->r_head_ack_queue) {
1428 spin_unlock_irqrestore(&qp->s_lock, flags);
1429 qp->r_nak_state = 0;
1430 qp->r_ack_psn = qp->r_psn - 1;
1431 goto send_ack;
1432 }
1433 /*
1434 * Resend the RDMA read or atomic op which
1435 * ACKs this duplicate request.
1436 */
1437 qp->s_ack_state = OP(ACKNOWLEDGE);
1438 qp->s_tail_ack_queue = i;
1439 break;
1440 }
1441 qp->r_nak_state = 0;
1442 tasklet_hi_schedule(&qp->s_task);
1443
1444 unlock_done:
1445 spin_unlock_irqrestore(&qp->s_lock, flags);
1446 done:
1447 return 1;
1448
1449 send_ack:
1450 return 0;
1451 }
1452
1453 static void ipath_rc_error(struct ipath_qp *qp, enum ib_wc_status err)
1454 {
1455 unsigned long flags;
1456
1457 spin_lock_irqsave(&qp->s_lock, flags);
1458 qp->state = IB_QPS_ERR;
1459 ipath_error_qp(qp, err);
1460 spin_unlock_irqrestore(&qp->s_lock, flags);
1461 }
1462
1463 /**
1464 * ipath_rc_rcv - process an incoming RC packet
1465 * @dev: the device this packet came in on
1466 * @hdr: the header of this packet
1467 * @has_grh: true if the header has a GRH
1468 * @data: the packet data
1469 * @tlen: the packet length
1470 * @qp: the QP for this packet
1471 *
1472 * This is called from ipath_qp_rcv() to process an incoming RC packet
1473 * for the given QP.
1474 * Called at interrupt level.
1475 */
1476 void ipath_rc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
1477 int has_grh, void *data, u32 tlen, struct ipath_qp *qp)
1478 {
1479 struct ipath_other_headers *ohdr;
1480 u32 opcode;
1481 u32 hdrsize;
1482 u32 psn;
1483 u32 pad;
1484 struct ib_wc wc;
1485 u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
1486 int diff;
1487 struct ib_reth *reth;
1488 int header_in_data;
1489
1490 /* Validate the SLID. See Ch. 9.6.1.5 */
1491 if (unlikely(be16_to_cpu(hdr->lrh[3]) != qp->remote_ah_attr.dlid))
1492 goto done;
1493
1494 /* Check for GRH */
1495 if (!has_grh) {
1496 ohdr = &hdr->u.oth;
1497 hdrsize = 8 + 12; /* LRH + BTH */
1498 psn = be32_to_cpu(ohdr->bth[2]);
1499 header_in_data = 0;
1500 } else {
1501 ohdr = &hdr->u.l.oth;
1502 hdrsize = 8 + 40 + 12; /* LRH + GRH + BTH */
1503 /*
1504 * The header with GRH is 60 bytes and the core driver sets
1505 * the eager header buffer size to 56 bytes so the last 4
1506 * bytes of the BTH header (PSN) is in the data buffer.
1507 */
1508 header_in_data = dev->dd->ipath_rcvhdrentsize == 16;
1509 if (header_in_data) {
1510 psn = be32_to_cpu(((__be32 *) data)[0]);
1511 data += sizeof(__be32);
1512 } else
1513 psn = be32_to_cpu(ohdr->bth[2]);
1514 }
1515
1516 /*
1517 * Process responses (ACKs) before anything else. Note that the
1518 * packet sequence number will be for something in the send work
1519 * queue rather than the expected receive packet sequence number.
1520 * In other words, this QP is the requester.
1521 */
1522 opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
1523 if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1524 opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
1525 ipath_rc_rcv_resp(dev, ohdr, data, tlen, qp, opcode, psn,
1526 hdrsize, pmtu, header_in_data);
1527 goto done;
1528 }
1529
1530 /* Compute 24 bits worth of difference. */
1531 diff = ipath_cmp24(psn, qp->r_psn);
1532 if (unlikely(diff)) {
1533 if (ipath_rc_rcv_error(dev, ohdr, data, qp, opcode,
1534 psn, diff, header_in_data))
1535 goto done;
1536 goto send_ack;
1537 }
1538
1539 /* Check for opcode sequence errors. */
1540 switch (qp->r_state) {
1541 case OP(SEND_FIRST):
1542 case OP(SEND_MIDDLE):
1543 if (opcode == OP(SEND_MIDDLE) ||
1544 opcode == OP(SEND_LAST) ||
1545 opcode == OP(SEND_LAST_WITH_IMMEDIATE))
1546 break;
1547 nack_inv:
1548 ipath_rc_error(qp, IB_WC_REM_INV_REQ_ERR);
1549 qp->r_nak_state = IB_NAK_INVALID_REQUEST;
1550 qp->r_ack_psn = qp->r_psn;
1551 goto send_ack;
1552
1553 case OP(RDMA_WRITE_FIRST):
1554 case OP(RDMA_WRITE_MIDDLE):
1555 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
1556 opcode == OP(RDMA_WRITE_LAST) ||
1557 opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1558 break;
1559 goto nack_inv;
1560
1561 default:
1562 if (opcode == OP(SEND_MIDDLE) ||
1563 opcode == OP(SEND_LAST) ||
1564 opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
1565 opcode == OP(RDMA_WRITE_MIDDLE) ||
1566 opcode == OP(RDMA_WRITE_LAST) ||
1567 opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1568 goto nack_inv;
1569 /*
1570 * Note that it is up to the requester to not send a new
1571 * RDMA read or atomic operation before receiving an ACK
1572 * for the previous operation.
1573 */
1574 break;
1575 }
1576
1577 wc.imm_data = 0;
1578 wc.wc_flags = 0;
1579
1580 /* OK, process the packet. */
1581 switch (opcode) {
1582 case OP(SEND_FIRST):
1583 if (!ipath_get_rwqe(qp, 0)) {
1584 rnr_nak:
1585 /*
1586 * A RNR NAK will ACK earlier sends and RDMA writes.
1587 * Don't queue the NAK if a RDMA read or atomic
1588 * is pending though.
1589 */
1590 if (qp->r_nak_state)
1591 goto done;
1592 qp->r_nak_state = IB_RNR_NAK | qp->r_min_rnr_timer;
1593 qp->r_ack_psn = qp->r_psn;
1594 goto send_ack;
1595 }
1596 qp->r_rcv_len = 0;
1597 /* FALLTHROUGH */
1598 case OP(SEND_MIDDLE):
1599 case OP(RDMA_WRITE_MIDDLE):
1600 send_middle:
1601 /* Check for invalid length PMTU or posted rwqe len. */
1602 if (unlikely(tlen != (hdrsize + pmtu + 4)))
1603 goto nack_inv;
1604 qp->r_rcv_len += pmtu;
1605 if (unlikely(qp->r_rcv_len > qp->r_len))
1606 goto nack_inv;
1607 ipath_copy_sge(&qp->r_sge, data, pmtu);
1608 break;
1609
1610 case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
1611 /* consume RWQE */
1612 if (!ipath_get_rwqe(qp, 1))
1613 goto rnr_nak;
1614 goto send_last_imm;
1615
1616 case OP(SEND_ONLY):
1617 case OP(SEND_ONLY_WITH_IMMEDIATE):
1618 if (!ipath_get_rwqe(qp, 0))
1619 goto rnr_nak;
1620 qp->r_rcv_len = 0;
1621 if (opcode == OP(SEND_ONLY))
1622 goto send_last;
1623 /* FALLTHROUGH */
1624 case OP(SEND_LAST_WITH_IMMEDIATE):
1625 send_last_imm:
1626 if (header_in_data) {
1627 wc.imm_data = *(__be32 *) data;
1628 data += sizeof(__be32);
1629 } else {
1630 /* Immediate data comes after BTH */
1631 wc.imm_data = ohdr->u.imm_data;
1632 }
1633 hdrsize += 4;
1634 wc.wc_flags = IB_WC_WITH_IMM;
1635 /* FALLTHROUGH */
1636 case OP(SEND_LAST):
1637 case OP(RDMA_WRITE_LAST):
1638 send_last:
1639 /* Get the number of bytes the message was padded by. */
1640 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1641 /* Check for invalid length. */
1642 /* XXX LAST len should be >= 1 */
1643 if (unlikely(tlen < (hdrsize + pad + 4)))
1644 goto nack_inv;
1645 /* Don't count the CRC. */
1646 tlen -= (hdrsize + pad + 4);
1647 wc.byte_len = tlen + qp->r_rcv_len;
1648 if (unlikely(wc.byte_len > qp->r_len))
1649 goto nack_inv;
1650 ipath_copy_sge(&qp->r_sge, data, tlen);
1651 qp->r_msn++;
1652 if (!qp->r_wrid_valid)
1653 break;
1654 qp->r_wrid_valid = 0;
1655 wc.wr_id = qp->r_wr_id;
1656 wc.status = IB_WC_SUCCESS;
1657 wc.opcode = IB_WC_RECV;
1658 wc.vendor_err = 0;
1659 wc.qp = &qp->ibqp;
1660 wc.src_qp = qp->remote_qpn;
1661 wc.pkey_index = 0;
1662 wc.slid = qp->remote_ah_attr.dlid;
1663 wc.sl = qp->remote_ah_attr.sl;
1664 wc.dlid_path_bits = 0;
1665 wc.port_num = 0;
1666 /* Signal completion event if the solicited bit is set. */
1667 ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
1668 (ohdr->bth[0] &
1669 __constant_cpu_to_be32(1 << 23)) != 0);
1670 break;
1671
1672 case OP(RDMA_WRITE_FIRST):
1673 case OP(RDMA_WRITE_ONLY):
1674 case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
1675 /* consume RWQE */
1676 /* RETH comes after BTH */
1677 if (!header_in_data)
1678 reth = &ohdr->u.rc.reth;
1679 else {
1680 reth = (struct ib_reth *)data;
1681 data += sizeof(*reth);
1682 }
1683 hdrsize += sizeof(*reth);
1684 qp->r_len = be32_to_cpu(reth->length);
1685 qp->r_rcv_len = 0;
1686 if (qp->r_len != 0) {
1687 u32 rkey = be32_to_cpu(reth->rkey);
1688 u64 vaddr = be64_to_cpu(reth->vaddr);
1689 int ok;
1690
1691 /* Check rkey & NAK */
1692 ok = ipath_rkey_ok(qp, &qp->r_sge,
1693 qp->r_len, vaddr, rkey,
1694 IB_ACCESS_REMOTE_WRITE);
1695 if (unlikely(!ok))
1696 goto nack_acc;
1697 } else {
1698 qp->r_sge.sg_list = NULL;
1699 qp->r_sge.sge.mr = NULL;
1700 qp->r_sge.sge.vaddr = NULL;
1701 qp->r_sge.sge.length = 0;
1702 qp->r_sge.sge.sge_length = 0;
1703 }
1704 if (unlikely(!(qp->qp_access_flags &
1705 IB_ACCESS_REMOTE_WRITE)))
1706 goto nack_acc;
1707 if (opcode == OP(RDMA_WRITE_FIRST))
1708 goto send_middle;
1709 else if (opcode == OP(RDMA_WRITE_ONLY))
1710 goto send_last;
1711 if (!ipath_get_rwqe(qp, 1))
1712 goto rnr_nak;
1713 goto send_last_imm;
1714
1715 case OP(RDMA_READ_REQUEST): {
1716 struct ipath_ack_entry *e;
1717 u32 len;
1718 u8 next;
1719
1720 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
1721 goto nack_acc;
1722 next = qp->r_head_ack_queue + 1;
1723 if (next > IPATH_MAX_RDMA_ATOMIC)
1724 next = 0;
1725 if (unlikely(next == qp->s_tail_ack_queue))
1726 goto nack_inv;
1727 e = &qp->s_ack_queue[qp->r_head_ack_queue];
1728 /* RETH comes after BTH */
1729 if (!header_in_data)
1730 reth = &ohdr->u.rc.reth;
1731 else {
1732 reth = (struct ib_reth *)data;
1733 data += sizeof(*reth);
1734 }
1735 len = be32_to_cpu(reth->length);
1736 if (len) {
1737 u32 rkey = be32_to_cpu(reth->rkey);
1738 u64 vaddr = be64_to_cpu(reth->vaddr);
1739 int ok;
1740
1741 /* Check rkey & NAK */
1742 ok = ipath_rkey_ok(qp, &e->rdma_sge, len, vaddr,
1743 rkey, IB_ACCESS_REMOTE_READ);
1744 if (unlikely(!ok))
1745 goto nack_acc;
1746 /*
1747 * Update the next expected PSN. We add 1 later
1748 * below, so only add the remainder here.
1749 */
1750 if (len > pmtu)
1751 qp->r_psn += (len - 1) / pmtu;
1752 } else {
1753 e->rdma_sge.sg_list = NULL;
1754 e->rdma_sge.num_sge = 0;
1755 e->rdma_sge.sge.mr = NULL;
1756 e->rdma_sge.sge.vaddr = NULL;
1757 e->rdma_sge.sge.length = 0;
1758 e->rdma_sge.sge.sge_length = 0;
1759 }
1760 e->opcode = opcode;
1761 e->psn = psn;
1762 /*
1763 * We need to increment the MSN here instead of when we
1764 * finish sending the result since a duplicate request would
1765 * increment it more than once.
1766 */
1767 qp->r_msn++;
1768 qp->r_psn++;
1769 qp->r_state = opcode;
1770 qp->r_nak_state = 0;
1771 barrier();
1772 qp->r_head_ack_queue = next;
1773
1774 /* Call ipath_do_rc_send() in another thread. */
1775 tasklet_hi_schedule(&qp->s_task);
1776
1777 goto done;
1778 }
1779
1780 case OP(COMPARE_SWAP):
1781 case OP(FETCH_ADD): {
1782 struct ib_atomic_eth *ateth;
1783 struct ipath_ack_entry *e;
1784 u64 vaddr;
1785 atomic64_t *maddr;
1786 u64 sdata;
1787 u32 rkey;
1788 u8 next;
1789
1790 if (unlikely(!(qp->qp_access_flags &
1791 IB_ACCESS_REMOTE_ATOMIC)))
1792 goto nack_acc;
1793 next = qp->r_head_ack_queue + 1;
1794 if (next > IPATH_MAX_RDMA_ATOMIC)
1795 next = 0;
1796 if (unlikely(next == qp->s_tail_ack_queue))
1797 goto nack_inv;
1798 if (!header_in_data)
1799 ateth = &ohdr->u.atomic_eth;
1800 else
1801 ateth = (struct ib_atomic_eth *)data;
1802 vaddr = ((u64) be32_to_cpu(ateth->vaddr[0]) << 32) |
1803 be32_to_cpu(ateth->vaddr[1]);
1804 if (unlikely(vaddr & (sizeof(u64) - 1)))
1805 goto nack_inv;
1806 rkey = be32_to_cpu(ateth->rkey);
1807 /* Check rkey & NAK */
1808 if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge,
1809 sizeof(u64), vaddr, rkey,
1810 IB_ACCESS_REMOTE_ATOMIC)))
1811 goto nack_acc;
1812 /* Perform atomic OP and save result. */
1813 maddr = (atomic64_t *) qp->r_sge.sge.vaddr;
1814 sdata = be64_to_cpu(ateth->swap_data);
1815 e = &qp->s_ack_queue[qp->r_head_ack_queue];
1816 e->atomic_data = (opcode == OP(FETCH_ADD)) ?
1817 (u64) atomic64_add_return(sdata, maddr) - sdata :
1818 (u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr,
1819 be64_to_cpu(ateth->compare_data),
1820 sdata);
1821 e->opcode = opcode;
1822 e->psn = psn & IPATH_PSN_MASK;
1823 qp->r_msn++;
1824 qp->r_psn++;
1825 qp->r_state = opcode;
1826 qp->r_nak_state = 0;
1827 barrier();
1828 qp->r_head_ack_queue = next;
1829
1830 /* Call ipath_do_rc_send() in another thread. */
1831 tasklet_hi_schedule(&qp->s_task);
1832
1833 goto done;
1834 }
1835
1836 default:
1837 /* NAK unknown opcodes. */
1838 goto nack_inv;
1839 }
1840 qp->r_psn++;
1841 qp->r_state = opcode;
1842 qp->r_ack_psn = psn;
1843 qp->r_nak_state = 0;
1844 /* Send an ACK if requested or required. */
1845 if (psn & (1 << 31))
1846 goto send_ack;
1847 goto done;
1848
1849 nack_acc:
1850 ipath_rc_error(qp, IB_WC_REM_ACCESS_ERR);
1851 qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
1852 qp->r_ack_psn = qp->r_psn;
1853
1854 send_ack:
1855 send_rc_ack(qp);
1856
1857 done:
1858 return;
1859 }
kernel source for telekom puls (alcatel/mediatek)