Merge branches 'topic/fix/hda' and 'topic/fix/sound-core' into for-linus
[linux-2.6] / 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                                  qp->remote_ah_attr.src_path_bits);
680         ohdr->bth[0] = cpu_to_be32(bth0);
681         ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
682         ohdr->bth[2] = cpu_to_be32(qp->r_ack_psn & IPATH_PSN_MASK);
683
684         writeq(hwords + 1, piobuf);
685
686         if (dd->ipath_flags & IPATH_PIO_FLUSH_WC) {
687                 u32 *hdrp = (u32 *) &hdr;
688
689                 ipath_flush_wc();
690                 __iowrite32_copy(piobuf + 2, hdrp, hwords - 1);
691                 ipath_flush_wc();
692                 __raw_writel(hdrp[hwords - 1], piobuf + hwords + 1);
693         } else
694                 __iowrite32_copy(piobuf + 2, (u32 *) &hdr, hwords);
695
696         ipath_flush_wc();
697
698         dev->n_unicast_xmit++;
699         goto done;
700
701 queue_ack:
702         if (ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK) {
703                 dev->n_rc_qacks++;
704                 qp->s_flags |= IPATH_S_ACK_PENDING;
705                 qp->s_nak_state = qp->r_nak_state;
706                 qp->s_ack_psn = qp->r_ack_psn;
707
708                 /* Schedule the send tasklet. */
709                 ipath_schedule_send(qp);
710         }
711         spin_unlock_irqrestore(&qp->s_lock, flags);
712 done:
713         return;
714 }
715
716 /**
717  * reset_psn - reset the QP state to send starting from PSN
718  * @qp: the QP
719  * @psn: the packet sequence number to restart at
720  *
721  * This is called from ipath_rc_rcv() to process an incoming RC ACK
722  * for the given QP.
723  * Called at interrupt level with the QP s_lock held.
724  */
725 static void reset_psn(struct ipath_qp *qp, u32 psn)
726 {
727         u32 n = qp->s_last;
728         struct ipath_swqe *wqe = get_swqe_ptr(qp, n);
729         u32 opcode;
730
731         qp->s_cur = n;
732
733         /*
734          * If we are starting the request from the beginning,
735          * let the normal send code handle initialization.
736          */
737         if (ipath_cmp24(psn, wqe->psn) <= 0) {
738                 qp->s_state = OP(SEND_LAST);
739                 goto done;
740         }
741
742         /* Find the work request opcode corresponding to the given PSN. */
743         opcode = wqe->wr.opcode;
744         for (;;) {
745                 int diff;
746
747                 if (++n == qp->s_size)
748                         n = 0;
749                 if (n == qp->s_tail)
750                         break;
751                 wqe = get_swqe_ptr(qp, n);
752                 diff = ipath_cmp24(psn, wqe->psn);
753                 if (diff < 0)
754                         break;
755                 qp->s_cur = n;
756                 /*
757                  * If we are starting the request from the beginning,
758                  * let the normal send code handle initialization.
759                  */
760                 if (diff == 0) {
761                         qp->s_state = OP(SEND_LAST);
762                         goto done;
763                 }
764                 opcode = wqe->wr.opcode;
765         }
766
767         /*
768          * Set the state to restart in the middle of a request.
769          * Don't change the s_sge, s_cur_sge, or s_cur_size.
770          * See ipath_make_rc_req().
771          */
772         switch (opcode) {
773         case IB_WR_SEND:
774         case IB_WR_SEND_WITH_IMM:
775                 qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
776                 break;
777
778         case IB_WR_RDMA_WRITE:
779         case IB_WR_RDMA_WRITE_WITH_IMM:
780                 qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
781                 break;
782
783         case IB_WR_RDMA_READ:
784                 qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
785                 break;
786
787         default:
788                 /*
789                  * This case shouldn't happen since its only
790                  * one PSN per req.
791                  */
792                 qp->s_state = OP(SEND_LAST);
793         }
794 done:
795         qp->s_psn = psn;
796 }
797
798 /**
799  * ipath_restart_rc - back up requester to resend the last un-ACKed request
800  * @qp: the QP to restart
801  * @psn: packet sequence number for the request
802  * @wc: the work completion request
803  *
804  * The QP s_lock should be held and interrupts disabled.
805  */
806 void ipath_restart_rc(struct ipath_qp *qp, u32 psn)
807 {
808         struct ipath_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
809         struct ipath_ibdev *dev;
810
811         if (qp->s_retry == 0) {
812                 ipath_send_complete(qp, wqe, IB_WC_RETRY_EXC_ERR);
813                 ipath_error_qp(qp, IB_WC_WR_FLUSH_ERR);
814                 goto bail;
815         }
816         qp->s_retry--;
817
818         /*
819          * Remove the QP from the timeout queue.
820          * Note: it may already have been removed by ipath_ib_timer().
821          */
822         dev = to_idev(qp->ibqp.device);
823         spin_lock(&dev->pending_lock);
824         if (!list_empty(&qp->timerwait))
825                 list_del_init(&qp->timerwait);
826         if (!list_empty(&qp->piowait))
827                 list_del_init(&qp->piowait);
828         spin_unlock(&dev->pending_lock);
829
830         if (wqe->wr.opcode == IB_WR_RDMA_READ)
831                 dev->n_rc_resends++;
832         else
833                 dev->n_rc_resends += (qp->s_psn - psn) & IPATH_PSN_MASK;
834
835         reset_psn(qp, psn);
836         ipath_schedule_send(qp);
837
838 bail:
839         return;
840 }
841
842 static inline void update_last_psn(struct ipath_qp *qp, u32 psn)
843 {
844         qp->s_last_psn = psn;
845 }
846
847 /**
848  * do_rc_ack - process an incoming RC ACK
849  * @qp: the QP the ACK came in on
850  * @psn: the packet sequence number of the ACK
851  * @opcode: the opcode of the request that resulted in the ACK
852  *
853  * This is called from ipath_rc_rcv_resp() to process an incoming RC ACK
854  * for the given QP.
855  * Called at interrupt level with the QP s_lock held and interrupts disabled.
856  * Returns 1 if OK, 0 if current operation should be aborted (NAK).
857  */
858 static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode,
859                      u64 val)
860 {
861         struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
862         struct ib_wc wc;
863         enum ib_wc_status status;
864         struct ipath_swqe *wqe;
865         int ret = 0;
866         u32 ack_psn;
867         int diff;
868
869         /*
870          * Remove the QP from the timeout queue (or RNR timeout queue).
871          * If ipath_ib_timer() has already removed it,
872          * it's OK since we hold the QP s_lock and ipath_restart_rc()
873          * just won't find anything to restart if we ACK everything.
874          */
875         spin_lock(&dev->pending_lock);
876         if (!list_empty(&qp->timerwait))
877                 list_del_init(&qp->timerwait);
878         spin_unlock(&dev->pending_lock);
879
880         /*
881          * Note that NAKs implicitly ACK outstanding SEND and RDMA write
882          * requests and implicitly NAK RDMA read and atomic requests issued
883          * before the NAK'ed request.  The MSN won't include the NAK'ed
884          * request but will include an ACK'ed request(s).
885          */
886         ack_psn = psn;
887         if (aeth >> 29)
888                 ack_psn--;
889         wqe = get_swqe_ptr(qp, qp->s_last);
890
891         /*
892          * The MSN might be for a later WQE than the PSN indicates so
893          * only complete WQEs that the PSN finishes.
894          */
895         while ((diff = ipath_cmp24(ack_psn, wqe->lpsn)) >= 0) {
896                 /*
897                  * RDMA_READ_RESPONSE_ONLY is a special case since
898                  * we want to generate completion events for everything
899                  * before the RDMA read, copy the data, then generate
900                  * the completion for the read.
901                  */
902                 if (wqe->wr.opcode == IB_WR_RDMA_READ &&
903                     opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
904                     diff == 0) {
905                         ret = 1;
906                         goto bail;
907                 }
908                 /*
909                  * If this request is a RDMA read or atomic, and the ACK is
910                  * for a later operation, this ACK NAKs the RDMA read or
911                  * atomic.  In other words, only a RDMA_READ_LAST or ONLY
912                  * can ACK a RDMA read and likewise for atomic ops.  Note
913                  * that the NAK case can only happen if relaxed ordering is
914                  * used and requests are sent after an RDMA read or atomic
915                  * is sent but before the response is received.
916                  */
917                 if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
918                      (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
919                     ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
920                       wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
921                      (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0))) {
922                         /*
923                          * The last valid PSN seen is the previous
924                          * request's.
925                          */
926                         update_last_psn(qp, wqe->psn - 1);
927                         /* Retry this request. */
928                         ipath_restart_rc(qp, wqe->psn);
929                         /*
930                          * No need to process the ACK/NAK since we are
931                          * restarting an earlier request.
932                          */
933                         goto bail;
934                 }
935                 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
936                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
937                         *(u64 *) wqe->sg_list[0].vaddr = val;
938                 if (qp->s_num_rd_atomic &&
939                     (wqe->wr.opcode == IB_WR_RDMA_READ ||
940                      wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
941                      wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
942                         qp->s_num_rd_atomic--;
943                         /* Restart sending task if fence is complete */
944                         if (((qp->s_flags & IPATH_S_FENCE_PENDING) &&
945                              !qp->s_num_rd_atomic) ||
946                             qp->s_flags & IPATH_S_RDMAR_PENDING)
947                                 ipath_schedule_send(qp);
948                 }
949                 /* Post a send completion queue entry if requested. */
950                 if (!(qp->s_flags & IPATH_S_SIGNAL_REQ_WR) ||
951                     (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
952                         memset(&wc, 0, sizeof wc);
953                         wc.wr_id = wqe->wr.wr_id;
954                         wc.status = IB_WC_SUCCESS;
955                         wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
956                         wc.byte_len = wqe->length;
957                         wc.qp = &qp->ibqp;
958                         wc.src_qp = qp->remote_qpn;
959                         wc.slid = qp->remote_ah_attr.dlid;
960                         wc.sl = qp->remote_ah_attr.sl;
961                         ipath_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 0);
962                 }
963                 qp->s_retry = qp->s_retry_cnt;
964                 /*
965                  * If we are completing a request which is in the process of
966                  * being resent, we can stop resending it since we know the
967                  * responder has already seen it.
968                  */
969                 if (qp->s_last == qp->s_cur) {
970                         if (++qp->s_cur >= qp->s_size)
971                                 qp->s_cur = 0;
972                         qp->s_last = qp->s_cur;
973                         if (qp->s_last == qp->s_tail)
974                                 break;
975                         wqe = get_swqe_ptr(qp, qp->s_cur);
976                         qp->s_state = OP(SEND_LAST);
977                         qp->s_psn = wqe->psn;
978                 } else {
979                         if (++qp->s_last >= qp->s_size)
980                                 qp->s_last = 0;
981                         if (qp->state == IB_QPS_SQD && qp->s_last == qp->s_cur)
982                                 qp->s_draining = 0;
983                         if (qp->s_last == qp->s_tail)
984                                 break;
985                         wqe = get_swqe_ptr(qp, qp->s_last);
986                 }
987         }
988
989         switch (aeth >> 29) {
990         case 0:         /* ACK */
991                 dev->n_rc_acks++;
992                 /* If this is a partial ACK, reset the retransmit timer. */
993                 if (qp->s_last != qp->s_tail) {
994                         spin_lock(&dev->pending_lock);
995                         if (list_empty(&qp->timerwait))
996                                 list_add_tail(&qp->timerwait,
997                                         &dev->pending[dev->pending_index]);
998                         spin_unlock(&dev->pending_lock);
999                         /*
1000                          * If we get a partial ACK for a resent operation,
1001                          * we can stop resending the earlier packets and
1002                          * continue with the next packet the receiver wants.
1003                          */
1004                         if (ipath_cmp24(qp->s_psn, psn) <= 0) {
1005                                 reset_psn(qp, psn + 1);
1006                                 ipath_schedule_send(qp);
1007                         }
1008                 } else if (ipath_cmp24(qp->s_psn, psn) <= 0) {
1009                         qp->s_state = OP(SEND_LAST);
1010                         qp->s_psn = psn + 1;
1011                 }
1012                 ipath_get_credit(qp, aeth);
1013                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1014                 qp->s_retry = qp->s_retry_cnt;
1015                 update_last_psn(qp, psn);
1016                 ret = 1;
1017                 goto bail;
1018
1019         case 1:         /* RNR NAK */
1020                 dev->n_rnr_naks++;
1021                 if (qp->s_last == qp->s_tail)
1022                         goto bail;
1023                 if (qp->s_rnr_retry == 0) {
1024                         status = IB_WC_RNR_RETRY_EXC_ERR;
1025                         goto class_b;
1026                 }
1027                 if (qp->s_rnr_retry_cnt < 7)
1028                         qp->s_rnr_retry--;
1029
1030                 /* The last valid PSN is the previous PSN. */
1031                 update_last_psn(qp, psn - 1);
1032
1033                 if (wqe->wr.opcode == IB_WR_RDMA_READ)
1034                         dev->n_rc_resends++;
1035                 else
1036                         dev->n_rc_resends +=
1037                                 (qp->s_psn - psn) & IPATH_PSN_MASK;
1038
1039                 reset_psn(qp, psn);
1040
1041                 qp->s_rnr_timeout =
1042                         ib_ipath_rnr_table[(aeth >> IPATH_AETH_CREDIT_SHIFT) &
1043                                            IPATH_AETH_CREDIT_MASK];
1044                 ipath_insert_rnr_queue(qp);
1045                 ipath_schedule_send(qp);
1046                 goto bail;
1047
1048         case 3:         /* NAK */
1049                 if (qp->s_last == qp->s_tail)
1050                         goto bail;
1051                 /* The last valid PSN is the previous PSN. */
1052                 update_last_psn(qp, psn - 1);
1053                 switch ((aeth >> IPATH_AETH_CREDIT_SHIFT) &
1054                         IPATH_AETH_CREDIT_MASK) {
1055                 case 0: /* PSN sequence error */
1056                         dev->n_seq_naks++;
1057                         /*
1058                          * Back up to the responder's expected PSN.
1059                          * Note that we might get a NAK in the middle of an
1060                          * RDMA READ response which terminates the RDMA
1061                          * READ.
1062                          */
1063                         ipath_restart_rc(qp, psn);
1064                         break;
1065
1066                 case 1: /* Invalid Request */
1067                         status = IB_WC_REM_INV_REQ_ERR;
1068                         dev->n_other_naks++;
1069                         goto class_b;
1070
1071                 case 2: /* Remote Access Error */
1072                         status = IB_WC_REM_ACCESS_ERR;
1073                         dev->n_other_naks++;
1074                         goto class_b;
1075
1076                 case 3: /* Remote Operation Error */
1077                         status = IB_WC_REM_OP_ERR;
1078                         dev->n_other_naks++;
1079                 class_b:
1080                         ipath_send_complete(qp, wqe, status);
1081                         ipath_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1082                         break;
1083
1084                 default:
1085                         /* Ignore other reserved NAK error codes */
1086                         goto reserved;
1087                 }
1088                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1089                 goto bail;
1090
1091         default:                /* 2: reserved */
1092         reserved:
1093                 /* Ignore reserved NAK codes. */
1094                 goto bail;
1095         }
1096
1097 bail:
1098         return ret;
1099 }
1100
1101 /**
1102  * ipath_rc_rcv_resp - process an incoming RC response packet
1103  * @dev: the device this packet came in on
1104  * @ohdr: the other headers for this packet
1105  * @data: the packet data
1106  * @tlen: the packet length
1107  * @qp: the QP for this packet
1108  * @opcode: the opcode for this packet
1109  * @psn: the packet sequence number for this packet
1110  * @hdrsize: the header length
1111  * @pmtu: the path MTU
1112  * @header_in_data: true if part of the header data is in the data buffer
1113  *
1114  * This is called from ipath_rc_rcv() to process an incoming RC response
1115  * packet for the given QP.
1116  * Called at interrupt level.
1117  */
1118 static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
1119                                      struct ipath_other_headers *ohdr,
1120                                      void *data, u32 tlen,
1121                                      struct ipath_qp *qp,
1122                                      u32 opcode,
1123                                      u32 psn, u32 hdrsize, u32 pmtu,
1124                                      int header_in_data)
1125 {
1126         struct ipath_swqe *wqe;
1127         enum ib_wc_status status;
1128         unsigned long flags;
1129         int diff;
1130         u32 pad;
1131         u32 aeth;
1132         u64 val;
1133
1134         spin_lock_irqsave(&qp->s_lock, flags);
1135
1136         /* Double check we can process this now that we hold the s_lock. */
1137         if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1138                 goto ack_done;
1139
1140         /* Ignore invalid responses. */
1141         if (ipath_cmp24(psn, qp->s_next_psn) >= 0)
1142                 goto ack_done;
1143
1144         /* Ignore duplicate responses. */
1145         diff = ipath_cmp24(psn, qp->s_last_psn);
1146         if (unlikely(diff <= 0)) {
1147                 /* Update credits for "ghost" ACKs */
1148                 if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
1149                         if (!header_in_data)
1150                                 aeth = be32_to_cpu(ohdr->u.aeth);
1151                         else {
1152                                 aeth = be32_to_cpu(((__be32 *) data)[0]);
1153                                 data += sizeof(__be32);
1154                         }
1155                         if ((aeth >> 29) == 0)
1156                                 ipath_get_credit(qp, aeth);
1157                 }
1158                 goto ack_done;
1159         }
1160
1161         if (unlikely(qp->s_last == qp->s_tail))
1162                 goto ack_done;
1163         wqe = get_swqe_ptr(qp, qp->s_last);
1164         status = IB_WC_SUCCESS;
1165
1166         switch (opcode) {
1167         case OP(ACKNOWLEDGE):
1168         case OP(ATOMIC_ACKNOWLEDGE):
1169         case OP(RDMA_READ_RESPONSE_FIRST):
1170                 if (!header_in_data)
1171                         aeth = be32_to_cpu(ohdr->u.aeth);
1172                 else {
1173                         aeth = be32_to_cpu(((__be32 *) data)[0]);
1174                         data += sizeof(__be32);
1175                 }
1176                 if (opcode == OP(ATOMIC_ACKNOWLEDGE)) {
1177                         if (!header_in_data) {
1178                                 __be32 *p = ohdr->u.at.atomic_ack_eth;
1179
1180                                 val = ((u64) be32_to_cpu(p[0]) << 32) |
1181                                         be32_to_cpu(p[1]);
1182                         } else
1183                                 val = be64_to_cpu(((__be64 *) data)[0]);
1184                 } else
1185                         val = 0;
1186                 if (!do_rc_ack(qp, aeth, psn, opcode, val) ||
1187                     opcode != OP(RDMA_READ_RESPONSE_FIRST))
1188                         goto ack_done;
1189                 hdrsize += 4;
1190                 wqe = get_swqe_ptr(qp, qp->s_last);
1191                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1192                         goto ack_op_err;
1193                 qp->r_flags &= ~IPATH_R_RDMAR_SEQ;
1194                 /*
1195                  * If this is a response to a resent RDMA read, we
1196                  * have to be careful to copy the data to the right
1197                  * location.
1198                  */
1199                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1200                                                   wqe, psn, pmtu);
1201                 goto read_middle;
1202
1203         case OP(RDMA_READ_RESPONSE_MIDDLE):
1204                 /* no AETH, no ACK */
1205                 if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
1206                         dev->n_rdma_seq++;
1207                         if (qp->r_flags & IPATH_R_RDMAR_SEQ)
1208                                 goto ack_done;
1209                         qp->r_flags |= IPATH_R_RDMAR_SEQ;
1210                         ipath_restart_rc(qp, qp->s_last_psn + 1);
1211                         goto ack_done;
1212                 }
1213                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1214                         goto ack_op_err;
1215         read_middle:
1216                 if (unlikely(tlen != (hdrsize + pmtu + 4)))
1217                         goto ack_len_err;
1218                 if (unlikely(pmtu >= qp->s_rdma_read_len))
1219                         goto ack_len_err;
1220
1221                 /* We got a response so update the timeout. */
1222                 spin_lock(&dev->pending_lock);
1223                 if (qp->s_rnr_timeout == 0 && !list_empty(&qp->timerwait))
1224                         list_move_tail(&qp->timerwait,
1225                                        &dev->pending[dev->pending_index]);
1226                 spin_unlock(&dev->pending_lock);
1227
1228                 if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
1229                         qp->s_retry = qp->s_retry_cnt;
1230
1231                 /*
1232                  * Update the RDMA receive state but do the copy w/o
1233                  * holding the locks and blocking interrupts.
1234                  */
1235                 qp->s_rdma_read_len -= pmtu;
1236                 update_last_psn(qp, psn);
1237                 spin_unlock_irqrestore(&qp->s_lock, flags);
1238                 ipath_copy_sge(&qp->s_rdma_read_sge, data, pmtu);
1239                 goto bail;
1240
1241         case OP(RDMA_READ_RESPONSE_ONLY):
1242                 if (!header_in_data)
1243                         aeth = be32_to_cpu(ohdr->u.aeth);
1244                 else
1245                         aeth = be32_to_cpu(((__be32 *) data)[0]);
1246                 if (!do_rc_ack(qp, aeth, psn, opcode, 0))
1247                         goto ack_done;
1248                 /* Get the number of bytes the message was padded by. */
1249                 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1250                 /*
1251                  * Check that the data size is >= 0 && <= pmtu.
1252                  * Remember to account for the AETH header (4) and
1253                  * ICRC (4).
1254                  */
1255                 if (unlikely(tlen < (hdrsize + pad + 8)))
1256                         goto ack_len_err;
1257                 /*
1258                  * If this is a response to a resent RDMA read, we
1259                  * have to be careful to copy the data to the right
1260                  * location.
1261                  */
1262                 wqe = get_swqe_ptr(qp, qp->s_last);
1263                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1264                                                   wqe, psn, pmtu);
1265                 goto read_last;
1266
1267         case OP(RDMA_READ_RESPONSE_LAST):
1268                 /* ACKs READ req. */
1269                 if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
1270                         dev->n_rdma_seq++;
1271                         if (qp->r_flags & IPATH_R_RDMAR_SEQ)
1272                                 goto ack_done;
1273                         qp->r_flags |= IPATH_R_RDMAR_SEQ;
1274                         ipath_restart_rc(qp, qp->s_last_psn + 1);
1275                         goto ack_done;
1276                 }
1277                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1278                         goto ack_op_err;
1279                 /* Get the number of bytes the message was padded by. */
1280                 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1281                 /*
1282                  * Check that the data size is >= 1 && <= pmtu.
1283                  * Remember to account for the AETH header (4) and
1284                  * ICRC (4).
1285                  */
1286                 if (unlikely(tlen <= (hdrsize + pad + 8)))
1287                         goto ack_len_err;
1288         read_last:
1289                 tlen -= hdrsize + pad + 8;
1290                 if (unlikely(tlen != qp->s_rdma_read_len))
1291                         goto ack_len_err;
1292                 if (!header_in_data)
1293                         aeth = be32_to_cpu(ohdr->u.aeth);
1294                 else {
1295                         aeth = be32_to_cpu(((__be32 *) data)[0]);
1296                         data += sizeof(__be32);
1297                 }
1298                 ipath_copy_sge(&qp->s_rdma_read_sge, data, tlen);
1299                 (void) do_rc_ack(qp, aeth, psn,
1300                                  OP(RDMA_READ_RESPONSE_LAST), 0);
1301                 goto ack_done;
1302         }
1303
1304 ack_op_err:
1305         status = IB_WC_LOC_QP_OP_ERR;
1306         goto ack_err;
1307
1308 ack_len_err:
1309         status = IB_WC_LOC_LEN_ERR;
1310 ack_err:
1311         ipath_send_complete(qp, wqe, status);
1312         ipath_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1313 ack_done:
1314         spin_unlock_irqrestore(&qp->s_lock, flags);
1315 bail:
1316         return;
1317 }
1318
1319 /**
1320  * ipath_rc_rcv_error - process an incoming duplicate or error RC packet
1321  * @dev: the device this packet came in on
1322  * @ohdr: the other headers for this packet
1323  * @data: the packet data
1324  * @qp: the QP for this packet
1325  * @opcode: the opcode for this packet
1326  * @psn: the packet sequence number for this packet
1327  * @diff: the difference between the PSN and the expected PSN
1328  * @header_in_data: true if part of the header data is in the data buffer
1329  *
1330  * This is called from ipath_rc_rcv() to process an unexpected
1331  * incoming RC packet for the given QP.
1332  * Called at interrupt level.
1333  * Return 1 if no more processing is needed; otherwise return 0 to
1334  * schedule a response to be sent.
1335  */
1336 static inline int ipath_rc_rcv_error(struct ipath_ibdev *dev,
1337                                      struct ipath_other_headers *ohdr,
1338                                      void *data,
1339                                      struct ipath_qp *qp,
1340                                      u32 opcode,
1341                                      u32 psn,
1342                                      int diff,
1343                                      int header_in_data)
1344 {
1345         struct ipath_ack_entry *e;
1346         u8 i, prev;
1347         int old_req;
1348         unsigned long flags;
1349
1350         if (diff > 0) {
1351                 /*
1352                  * Packet sequence error.
1353                  * A NAK will ACK earlier sends and RDMA writes.
1354                  * Don't queue the NAK if we already sent one.
1355                  */
1356                 if (!qp->r_nak_state) {
1357                         qp->r_nak_state = IB_NAK_PSN_ERROR;
1358                         /* Use the expected PSN. */
1359                         qp->r_ack_psn = qp->r_psn;
1360                         goto send_ack;
1361                 }
1362                 goto done;
1363         }
1364
1365         /*
1366          * Handle a duplicate request.  Don't re-execute SEND, RDMA
1367          * write or atomic op.  Don't NAK errors, just silently drop
1368          * the duplicate request.  Note that r_sge, r_len, and
1369          * r_rcv_len may be in use so don't modify them.
1370          *
1371          * We are supposed to ACK the earliest duplicate PSN but we
1372          * can coalesce an outstanding duplicate ACK.  We have to
1373          * send the earliest so that RDMA reads can be restarted at
1374          * the requester's expected PSN.
1375          *
1376          * First, find where this duplicate PSN falls within the
1377          * ACKs previously sent.
1378          */
1379         psn &= IPATH_PSN_MASK;
1380         e = NULL;
1381         old_req = 1;
1382
1383         spin_lock_irqsave(&qp->s_lock, flags);
1384         /* Double check we can process this now that we hold the s_lock. */
1385         if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1386                 goto unlock_done;
1387
1388         for (i = qp->r_head_ack_queue; ; i = prev) {
1389                 if (i == qp->s_tail_ack_queue)
1390                         old_req = 0;
1391                 if (i)
1392                         prev = i - 1;
1393                 else
1394                         prev = IPATH_MAX_RDMA_ATOMIC;
1395                 if (prev == qp->r_head_ack_queue) {
1396                         e = NULL;
1397                         break;
1398                 }
1399                 e = &qp->s_ack_queue[prev];
1400                 if (!e->opcode) {
1401                         e = NULL;
1402                         break;
1403                 }
1404                 if (ipath_cmp24(psn, e->psn) >= 0) {
1405                         if (prev == qp->s_tail_ack_queue)
1406                                 old_req = 0;
1407                         break;
1408                 }
1409         }
1410         switch (opcode) {
1411         case OP(RDMA_READ_REQUEST): {
1412                 struct ib_reth *reth;
1413                 u32 offset;
1414                 u32 len;
1415
1416                 /*
1417                  * If we didn't find the RDMA read request in the ack queue,
1418                  * or the send tasklet is already backed up to send an
1419                  * earlier entry, we can ignore this request.
1420                  */
1421                 if (!e || e->opcode != OP(RDMA_READ_REQUEST) || old_req)
1422                         goto unlock_done;
1423                 /* RETH comes after BTH */
1424                 if (!header_in_data)
1425                         reth = &ohdr->u.rc.reth;
1426                 else {
1427                         reth = (struct ib_reth *)data;
1428                         data += sizeof(*reth);
1429                 }
1430                 /*
1431                  * Address range must be a subset of the original
1432                  * request and start on pmtu boundaries.
1433                  * We reuse the old ack_queue slot since the requester
1434                  * should not back up and request an earlier PSN for the
1435                  * same request.
1436                  */
1437                 offset = ((psn - e->psn) & IPATH_PSN_MASK) *
1438                         ib_mtu_enum_to_int(qp->path_mtu);
1439                 len = be32_to_cpu(reth->length);
1440                 if (unlikely(offset + len > e->rdma_sge.sge.sge_length))
1441                         goto unlock_done;
1442                 if (len != 0) {
1443                         u32 rkey = be32_to_cpu(reth->rkey);
1444                         u64 vaddr = be64_to_cpu(reth->vaddr);
1445                         int ok;
1446
1447                         ok = ipath_rkey_ok(qp, &e->rdma_sge,
1448                                            len, vaddr, rkey,
1449                                            IB_ACCESS_REMOTE_READ);
1450                         if (unlikely(!ok))
1451                                 goto unlock_done;
1452                 } else {
1453                         e->rdma_sge.sg_list = NULL;
1454                         e->rdma_sge.num_sge = 0;
1455                         e->rdma_sge.sge.mr = NULL;
1456                         e->rdma_sge.sge.vaddr = NULL;
1457                         e->rdma_sge.sge.length = 0;
1458                         e->rdma_sge.sge.sge_length = 0;
1459                 }
1460                 e->psn = psn;
1461                 qp->s_ack_state = OP(ACKNOWLEDGE);
1462                 qp->s_tail_ack_queue = prev;
1463                 break;
1464         }
1465
1466         case OP(COMPARE_SWAP):
1467         case OP(FETCH_ADD): {
1468                 /*
1469                  * If we didn't find the atomic request in the ack queue
1470                  * or the send tasklet is already backed up to send an
1471                  * earlier entry, we can ignore this request.
1472                  */
1473                 if (!e || e->opcode != (u8) opcode || old_req)
1474                         goto unlock_done;
1475                 qp->s_ack_state = OP(ACKNOWLEDGE);
1476                 qp->s_tail_ack_queue = prev;
1477                 break;
1478         }
1479
1480         default:
1481                 if (old_req)
1482                         goto unlock_done;
1483                 /*
1484                  * Resend the most recent ACK if this request is
1485                  * after all the previous RDMA reads and atomics.
1486                  */
1487                 if (i == qp->r_head_ack_queue) {
1488                         spin_unlock_irqrestore(&qp->s_lock, flags);
1489                         qp->r_nak_state = 0;
1490                         qp->r_ack_psn = qp->r_psn - 1;
1491                         goto send_ack;
1492                 }
1493                 /*
1494                  * Try to send a simple ACK to work around a Mellanox bug
1495                  * which doesn't accept a RDMA read response or atomic
1496                  * response as an ACK for earlier SENDs or RDMA writes.
1497                  */
1498                 if (qp->r_head_ack_queue == qp->s_tail_ack_queue &&
1499                     !(qp->s_flags & IPATH_S_ACK_PENDING) &&
1500                     qp->s_ack_state == OP(ACKNOWLEDGE)) {
1501                         spin_unlock_irqrestore(&qp->s_lock, flags);
1502                         qp->r_nak_state = 0;
1503                         qp->r_ack_psn = qp->s_ack_queue[i].psn - 1;
1504                         goto send_ack;
1505                 }
1506                 /*
1507                  * Resend the RDMA read or atomic op which
1508                  * ACKs this duplicate request.
1509                  */
1510                 qp->s_ack_state = OP(ACKNOWLEDGE);
1511                 qp->s_tail_ack_queue = i;
1512                 break;
1513         }
1514         qp->r_nak_state = 0;
1515         ipath_schedule_send(qp);
1516
1517 unlock_done:
1518         spin_unlock_irqrestore(&qp->s_lock, flags);
1519 done:
1520         return 1;
1521
1522 send_ack:
1523         return 0;
1524 }
1525
1526 void ipath_rc_error(struct ipath_qp *qp, enum ib_wc_status err)
1527 {
1528         unsigned long flags;
1529         int lastwqe;
1530
1531         spin_lock_irqsave(&qp->s_lock, flags);
1532         lastwqe = ipath_error_qp(qp, err);
1533         spin_unlock_irqrestore(&qp->s_lock, flags);
1534
1535         if (lastwqe) {
1536                 struct ib_event ev;
1537
1538                 ev.device = qp->ibqp.device;
1539                 ev.element.qp = &qp->ibqp;
1540                 ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
1541                 qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
1542         }
1543 }
1544
1545 static inline void ipath_update_ack_queue(struct ipath_qp *qp, unsigned n)
1546 {
1547         unsigned next;
1548
1549         next = n + 1;
1550         if (next > IPATH_MAX_RDMA_ATOMIC)
1551                 next = 0;
1552         if (n == qp->s_tail_ack_queue) {
1553                 qp->s_tail_ack_queue = next;
1554                 qp->s_ack_state = OP(ACKNOWLEDGE);
1555         }
1556 }
1557
1558 /**
1559  * ipath_rc_rcv - process an incoming RC packet
1560  * @dev: the device this packet came in on
1561  * @hdr: the header of this packet
1562  * @has_grh: true if the header has a GRH
1563  * @data: the packet data
1564  * @tlen: the packet length
1565  * @qp: the QP for this packet
1566  *
1567  * This is called from ipath_qp_rcv() to process an incoming RC packet
1568  * for the given QP.
1569  * Called at interrupt level.
1570  */
1571 void ipath_rc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
1572                   int has_grh, void *data, u32 tlen, struct ipath_qp *qp)
1573 {
1574         struct ipath_other_headers *ohdr;
1575         u32 opcode;
1576         u32 hdrsize;
1577         u32 psn;
1578         u32 pad;
1579         struct ib_wc wc;
1580         u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
1581         int diff;
1582         struct ib_reth *reth;
1583         int header_in_data;
1584         unsigned long flags;
1585
1586         /* Validate the SLID. See Ch. 9.6.1.5 */
1587         if (unlikely(be16_to_cpu(hdr->lrh[3]) != qp->remote_ah_attr.dlid))
1588                 goto done;
1589
1590         /* Check for GRH */
1591         if (!has_grh) {
1592                 ohdr = &hdr->u.oth;
1593                 hdrsize = 8 + 12;       /* LRH + BTH */
1594                 psn = be32_to_cpu(ohdr->bth[2]);
1595                 header_in_data = 0;
1596         } else {
1597                 ohdr = &hdr->u.l.oth;
1598                 hdrsize = 8 + 40 + 12;  /* LRH + GRH + BTH */
1599                 /*
1600                  * The header with GRH is 60 bytes and the core driver sets
1601                  * the eager header buffer size to 56 bytes so the last 4
1602                  * bytes of the BTH header (PSN) is in the data buffer.
1603                  */
1604                 header_in_data = dev->dd->ipath_rcvhdrentsize == 16;
1605                 if (header_in_data) {
1606                         psn = be32_to_cpu(((__be32 *) data)[0]);
1607                         data += sizeof(__be32);
1608                 } else
1609                         psn = be32_to_cpu(ohdr->bth[2]);
1610         }
1611
1612         /*
1613          * Process responses (ACKs) before anything else.  Note that the
1614          * packet sequence number will be for something in the send work
1615          * queue rather than the expected receive packet sequence number.
1616          * In other words, this QP is the requester.
1617          */
1618         opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
1619         if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1620             opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
1621                 ipath_rc_rcv_resp(dev, ohdr, data, tlen, qp, opcode, psn,
1622                                   hdrsize, pmtu, header_in_data);
1623                 goto done;
1624         }
1625
1626         /* Compute 24 bits worth of difference. */
1627         diff = ipath_cmp24(psn, qp->r_psn);
1628         if (unlikely(diff)) {
1629                 if (ipath_rc_rcv_error(dev, ohdr, data, qp, opcode,
1630                                        psn, diff, header_in_data))
1631                         goto done;
1632                 goto send_ack;
1633         }
1634
1635         /* Check for opcode sequence errors. */
1636         switch (qp->r_state) {
1637         case OP(SEND_FIRST):
1638         case OP(SEND_MIDDLE):
1639                 if (opcode == OP(SEND_MIDDLE) ||
1640                     opcode == OP(SEND_LAST) ||
1641                     opcode == OP(SEND_LAST_WITH_IMMEDIATE))
1642                         break;
1643                 goto nack_inv;
1644
1645         case OP(RDMA_WRITE_FIRST):
1646         case OP(RDMA_WRITE_MIDDLE):
1647                 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
1648                     opcode == OP(RDMA_WRITE_LAST) ||
1649                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1650                         break;
1651                 goto nack_inv;
1652
1653         default:
1654                 if (opcode == OP(SEND_MIDDLE) ||
1655                     opcode == OP(SEND_LAST) ||
1656                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
1657                     opcode == OP(RDMA_WRITE_MIDDLE) ||
1658                     opcode == OP(RDMA_WRITE_LAST) ||
1659                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1660                         goto nack_inv;
1661                 /*
1662                  * Note that it is up to the requester to not send a new
1663                  * RDMA read or atomic operation before receiving an ACK
1664                  * for the previous operation.
1665                  */
1666                 break;
1667         }
1668
1669         memset(&wc, 0, sizeof wc);
1670
1671         /* OK, process the packet. */
1672         switch (opcode) {
1673         case OP(SEND_FIRST):
1674                 if (!ipath_get_rwqe(qp, 0))
1675                         goto rnr_nak;
1676                 qp->r_rcv_len = 0;
1677                 /* FALLTHROUGH */
1678         case OP(SEND_MIDDLE):
1679         case OP(RDMA_WRITE_MIDDLE):
1680         send_middle:
1681                 /* Check for invalid length PMTU or posted rwqe len. */
1682                 if (unlikely(tlen != (hdrsize + pmtu + 4)))
1683                         goto nack_inv;
1684                 qp->r_rcv_len += pmtu;
1685                 if (unlikely(qp->r_rcv_len > qp->r_len))
1686                         goto nack_inv;
1687                 ipath_copy_sge(&qp->r_sge, data, pmtu);
1688                 break;
1689
1690         case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
1691                 /* consume RWQE */
1692                 if (!ipath_get_rwqe(qp, 1))
1693                         goto rnr_nak;
1694                 goto send_last_imm;
1695
1696         case OP(SEND_ONLY):
1697         case OP(SEND_ONLY_WITH_IMMEDIATE):
1698                 if (!ipath_get_rwqe(qp, 0))
1699                         goto rnr_nak;
1700                 qp->r_rcv_len = 0;
1701                 if (opcode == OP(SEND_ONLY))
1702                         goto send_last;
1703                 /* FALLTHROUGH */
1704         case OP(SEND_LAST_WITH_IMMEDIATE):
1705         send_last_imm:
1706                 if (header_in_data) {
1707                         wc.ex.imm_data = *(__be32 *) data;
1708                         data += sizeof(__be32);
1709                 } else {
1710                         /* Immediate data comes after BTH */
1711                         wc.ex.imm_data = ohdr->u.imm_data;
1712                 }
1713                 hdrsize += 4;
1714                 wc.wc_flags = IB_WC_WITH_IMM;
1715                 /* FALLTHROUGH */
1716         case OP(SEND_LAST):
1717         case OP(RDMA_WRITE_LAST):
1718         send_last:
1719                 /* Get the number of bytes the message was padded by. */
1720                 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1721                 /* Check for invalid length. */
1722                 /* XXX LAST len should be >= 1 */
1723                 if (unlikely(tlen < (hdrsize + pad + 4)))
1724                         goto nack_inv;
1725                 /* Don't count the CRC. */
1726                 tlen -= (hdrsize + pad + 4);
1727                 wc.byte_len = tlen + qp->r_rcv_len;
1728                 if (unlikely(wc.byte_len > qp->r_len))
1729                         goto nack_inv;
1730                 ipath_copy_sge(&qp->r_sge, data, tlen);
1731                 qp->r_msn++;
1732                 if (!test_and_clear_bit(IPATH_R_WRID_VALID, &qp->r_aflags))
1733                         break;
1734                 wc.wr_id = qp->r_wr_id;
1735                 wc.status = IB_WC_SUCCESS;
1736                 if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
1737                     opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
1738                         wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
1739                 else
1740                         wc.opcode = IB_WC_RECV;
1741                 wc.qp = &qp->ibqp;
1742                 wc.src_qp = qp->remote_qpn;
1743                 wc.slid = qp->remote_ah_attr.dlid;
1744                 wc.sl = qp->remote_ah_attr.sl;
1745                 /* Signal completion event if the solicited bit is set. */
1746                 ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
1747                                (ohdr->bth[0] &
1748                                 __constant_cpu_to_be32(1 << 23)) != 0);
1749                 break;
1750
1751         case OP(RDMA_WRITE_FIRST):
1752         case OP(RDMA_WRITE_ONLY):
1753         case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
1754                 if (unlikely(!(qp->qp_access_flags &
1755                                IB_ACCESS_REMOTE_WRITE)))
1756                         goto nack_inv;
1757                 /* consume RWQE */
1758                 /* RETH comes after BTH */
1759                 if (!header_in_data)
1760                         reth = &ohdr->u.rc.reth;
1761                 else {
1762                         reth = (struct ib_reth *)data;
1763                         data += sizeof(*reth);
1764                 }
1765                 hdrsize += sizeof(*reth);
1766                 qp->r_len = be32_to_cpu(reth->length);
1767                 qp->r_rcv_len = 0;
1768                 if (qp->r_len != 0) {
1769                         u32 rkey = be32_to_cpu(reth->rkey);
1770                         u64 vaddr = be64_to_cpu(reth->vaddr);
1771                         int ok;
1772
1773                         /* Check rkey & NAK */
1774                         ok = ipath_rkey_ok(qp, &qp->r_sge,
1775                                            qp->r_len, vaddr, rkey,
1776                                            IB_ACCESS_REMOTE_WRITE);
1777                         if (unlikely(!ok))
1778                                 goto nack_acc;
1779                 } else {
1780                         qp->r_sge.sg_list = NULL;
1781                         qp->r_sge.sge.mr = NULL;
1782                         qp->r_sge.sge.vaddr = NULL;
1783                         qp->r_sge.sge.length = 0;
1784                         qp->r_sge.sge.sge_length = 0;
1785                 }
1786                 if (opcode == OP(RDMA_WRITE_FIRST))
1787                         goto send_middle;
1788                 else if (opcode == OP(RDMA_WRITE_ONLY))
1789                         goto send_last;
1790                 if (!ipath_get_rwqe(qp, 1))
1791                         goto rnr_nak;
1792                 goto send_last_imm;
1793
1794         case OP(RDMA_READ_REQUEST): {
1795                 struct ipath_ack_entry *e;
1796                 u32 len;
1797                 u8 next;
1798
1799                 if (unlikely(!(qp->qp_access_flags &
1800                                IB_ACCESS_REMOTE_READ)))
1801                         goto nack_inv;
1802                 next = qp->r_head_ack_queue + 1;
1803                 if (next > IPATH_MAX_RDMA_ATOMIC)
1804                         next = 0;
1805                 spin_lock_irqsave(&qp->s_lock, flags);
1806                 /* Double check we can process this while holding the s_lock. */
1807                 if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1808                         goto unlock;
1809                 if (unlikely(next == qp->s_tail_ack_queue)) {
1810                         if (!qp->s_ack_queue[next].sent)
1811                                 goto nack_inv_unlck;
1812                         ipath_update_ack_queue(qp, next);
1813                 }
1814                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
1815                 /* RETH comes after BTH */
1816                 if (!header_in_data)
1817                         reth = &ohdr->u.rc.reth;
1818                 else {
1819                         reth = (struct ib_reth *)data;
1820                         data += sizeof(*reth);
1821                 }
1822                 len = be32_to_cpu(reth->length);
1823                 if (len) {
1824                         u32 rkey = be32_to_cpu(reth->rkey);
1825                         u64 vaddr = be64_to_cpu(reth->vaddr);
1826                         int ok;
1827
1828                         /* Check rkey & NAK */
1829                         ok = ipath_rkey_ok(qp, &e->rdma_sge, len, vaddr,
1830                                            rkey, IB_ACCESS_REMOTE_READ);
1831                         if (unlikely(!ok))
1832                                 goto nack_acc_unlck;
1833                         /*
1834                          * Update the next expected PSN.  We add 1 later
1835                          * below, so only add the remainder here.
1836                          */
1837                         if (len > pmtu)
1838                                 qp->r_psn += (len - 1) / pmtu;
1839                 } else {
1840                         e->rdma_sge.sg_list = NULL;
1841                         e->rdma_sge.num_sge = 0;
1842                         e->rdma_sge.sge.mr = NULL;
1843                         e->rdma_sge.sge.vaddr = NULL;
1844                         e->rdma_sge.sge.length = 0;
1845                         e->rdma_sge.sge.sge_length = 0;
1846                 }
1847                 e->opcode = opcode;
1848                 e->sent = 0;
1849                 e->psn = psn;
1850                 /*
1851                  * We need to increment the MSN here instead of when we
1852                  * finish sending the result since a duplicate request would
1853                  * increment it more than once.
1854                  */
1855                 qp->r_msn++;
1856                 qp->r_psn++;
1857                 qp->r_state = opcode;
1858                 qp->r_nak_state = 0;
1859                 qp->r_head_ack_queue = next;
1860
1861                 /* Schedule the send tasklet. */
1862                 ipath_schedule_send(qp);
1863
1864                 goto unlock;
1865         }
1866
1867         case OP(COMPARE_SWAP):
1868         case OP(FETCH_ADD): {
1869                 struct ib_atomic_eth *ateth;
1870                 struct ipath_ack_entry *e;
1871                 u64 vaddr;
1872                 atomic64_t *maddr;
1873                 u64 sdata;
1874                 u32 rkey;
1875                 u8 next;
1876
1877                 if (unlikely(!(qp->qp_access_flags &
1878                                IB_ACCESS_REMOTE_ATOMIC)))
1879                         goto nack_inv;
1880                 next = qp->r_head_ack_queue + 1;
1881                 if (next > IPATH_MAX_RDMA_ATOMIC)
1882                         next = 0;
1883                 spin_lock_irqsave(&qp->s_lock, flags);
1884                 /* Double check we can process this while holding the s_lock. */
1885                 if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1886                         goto unlock;
1887                 if (unlikely(next == qp->s_tail_ack_queue)) {
1888                         if (!qp->s_ack_queue[next].sent)
1889                                 goto nack_inv_unlck;
1890                         ipath_update_ack_queue(qp, next);
1891                 }
1892                 if (!header_in_data)
1893                         ateth = &ohdr->u.atomic_eth;
1894                 else
1895                         ateth = (struct ib_atomic_eth *)data;
1896                 vaddr = ((u64) be32_to_cpu(ateth->vaddr[0]) << 32) |
1897                         be32_to_cpu(ateth->vaddr[1]);
1898                 if (unlikely(vaddr & (sizeof(u64) - 1)))
1899                         goto nack_inv_unlck;
1900                 rkey = be32_to_cpu(ateth->rkey);
1901                 /* Check rkey & NAK */
1902                 if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge,
1903                                             sizeof(u64), vaddr, rkey,
1904                                             IB_ACCESS_REMOTE_ATOMIC)))
1905                         goto nack_acc_unlck;
1906                 /* Perform atomic OP and save result. */
1907                 maddr = (atomic64_t *) qp->r_sge.sge.vaddr;
1908                 sdata = be64_to_cpu(ateth->swap_data);
1909                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
1910                 e->atomic_data = (opcode == OP(FETCH_ADD)) ?
1911                         (u64) atomic64_add_return(sdata, maddr) - sdata :
1912                         (u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr,
1913                                       be64_to_cpu(ateth->compare_data),
1914                                       sdata);
1915                 e->opcode = opcode;
1916                 e->sent = 0;
1917                 e->psn = psn & IPATH_PSN_MASK;
1918                 qp->r_msn++;
1919                 qp->r_psn++;
1920                 qp->r_state = opcode;
1921                 qp->r_nak_state = 0;
1922                 qp->r_head_ack_queue = next;
1923
1924                 /* Schedule the send tasklet. */
1925                 ipath_schedule_send(qp);
1926
1927                 goto unlock;
1928         }
1929
1930         default:
1931                 /* NAK unknown opcodes. */
1932                 goto nack_inv;
1933         }
1934         qp->r_psn++;
1935         qp->r_state = opcode;
1936         qp->r_ack_psn = psn;
1937         qp->r_nak_state = 0;
1938         /* Send an ACK if requested or required. */
1939         if (psn & (1 << 31))
1940                 goto send_ack;
1941         goto done;
1942
1943 rnr_nak:
1944         qp->r_nak_state = IB_RNR_NAK | qp->r_min_rnr_timer;
1945         qp->r_ack_psn = qp->r_psn;
1946         goto send_ack;
1947
1948 nack_inv_unlck:
1949         spin_unlock_irqrestore(&qp->s_lock, flags);
1950 nack_inv:
1951         ipath_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
1952         qp->r_nak_state = IB_NAK_INVALID_REQUEST;
1953         qp->r_ack_psn = qp->r_psn;
1954         goto send_ack;
1955
1956 nack_acc_unlck:
1957         spin_unlock_irqrestore(&qp->s_lock, flags);
1958 nack_acc:
1959         ipath_rc_error(qp, IB_WC_LOC_PROT_ERR);
1960         qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
1961         qp->r_ack_psn = qp->r_psn;
1962 send_ack:
1963         send_rc_ack(qp);
1964         goto done;
1965
1966 unlock:
1967         spin_unlock_irqrestore(&qp->s_lock, flags);
1968 done:
1969         return;
1970 }