5b5276a270bcca9aabeec32995cfaaae84f6665c
[linux-2.6.git] / drivers / infiniband / hw / ipath / ipath_rc.c
1 /*
2  * Copyright (c) 2006, 2007, 2008 QLogic Corporation. All rights reserved.
3  * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33
34 #include <linux/io.h>
35
36 #include "ipath_verbs.h"
37 #include "ipath_kernel.h"
38
39 /* cut down ridiculously long IB macro names */
40 #define OP(x) IB_OPCODE_RC_##x
41
42 static u32 restart_sge(struct ipath_sge_state *ss, struct ipath_swqe *wqe,
43                        u32 psn, u32 pmtu)
44 {
45         u32 len;
46
47         len = ((psn - wqe->psn) & IPATH_PSN_MASK) * pmtu;
48         ss->sge = wqe->sg_list[0];
49         ss->sg_list = wqe->sg_list + 1;
50         ss->num_sge = wqe->wr.num_sge;
51         ipath_skip_sge(ss, len);
52         return wqe->length - len;
53 }
54
55 /**
56  * ipath_init_restart- initialize the qp->s_sge after a restart
57  * @qp: the QP who's SGE we're restarting
58  * @wqe: the work queue to initialize the QP's SGE from
59  *
60  * The QP s_lock should be held and interrupts disabled.
61  */
62 static void ipath_init_restart(struct ipath_qp *qp, struct ipath_swqe *wqe)
63 {
64         struct ipath_ibdev *dev;
65
66         qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn,
67                                 ib_mtu_enum_to_int(qp->path_mtu));
68         dev = to_idev(qp->ibqp.device);
69         spin_lock(&dev->pending_lock);
70         if (list_empty(&qp->timerwait))
71                 list_add_tail(&qp->timerwait,
72                               &dev->pending[dev->pending_index]);
73         spin_unlock(&dev->pending_lock);
74 }
75
76 /**
77  * ipath_make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
78  * @qp: a pointer to the QP
79  * @ohdr: a pointer to the IB header being constructed
80  * @pmtu: the path MTU
81  *
82  * Return 1 if constructed; otherwise, return 0.
83  * Note that we are in the responder's side of the QP context.
84  * Note the QP s_lock must be held.
85  */
86 static int ipath_make_rc_ack(struct ipath_ibdev *dev, struct ipath_qp *qp,
87                              struct ipath_other_headers *ohdr, u32 pmtu)
88 {
89         struct ipath_ack_entry *e;
90         u32 hwords;
91         u32 len;
92         u32 bth0;
93         u32 bth2;
94
95         /* Don't send an ACK if we aren't supposed to. */
96         if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
97                 goto bail;
98
99         /* header size in 32-bit words LRH+BTH = (8+12)/4. */
100         hwords = 5;
101
102         switch (qp->s_ack_state) {
103         case OP(RDMA_READ_RESPONSE_LAST):
104         case OP(RDMA_READ_RESPONSE_ONLY):
105         case OP(ATOMIC_ACKNOWLEDGE):
106                 /*
107                  * We can increment the tail pointer now that the last
108                  * response has been sent instead of only being
109                  * constructed.
110                  */
111                 if (++qp->s_tail_ack_queue > IPATH_MAX_RDMA_ATOMIC)
112                         qp->s_tail_ack_queue = 0;
113                 /* FALLTHROUGH */
114         case OP(SEND_ONLY):
115         case OP(ACKNOWLEDGE):
116                 /* Check for no next entry in the queue. */
117                 if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
118                         if (qp->s_flags & IPATH_S_ACK_PENDING)
119                                 goto normal;
120                         qp->s_ack_state = OP(ACKNOWLEDGE);
121                         goto bail;
122                 }
123
124                 e = &qp->s_ack_queue[qp->s_tail_ack_queue];
125                 if (e->opcode == OP(RDMA_READ_REQUEST)) {
126                         /* Copy SGE state in case we need to resend */
127                         qp->s_ack_rdma_sge = e->rdma_sge;
128                         qp->s_cur_sge = &qp->s_ack_rdma_sge;
129                         len = e->rdma_sge.sge.sge_length;
130                         if (len > pmtu) {
131                                 len = pmtu;
132                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
133                         } else {
134                                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
135                                 e->sent = 1;
136                         }
137                         ohdr->u.aeth = ipath_compute_aeth(qp);
138                         hwords++;
139                         qp->s_ack_rdma_psn = e->psn;
140                         bth2 = qp->s_ack_rdma_psn++ & IPATH_PSN_MASK;
141                 } else {
142                         /* COMPARE_SWAP or FETCH_ADD */
143                         qp->s_cur_sge = NULL;
144                         len = 0;
145                         qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
146                         ohdr->u.at.aeth = ipath_compute_aeth(qp);
147                         ohdr->u.at.atomic_ack_eth[0] =
148                                 cpu_to_be32(e->atomic_data >> 32);
149                         ohdr->u.at.atomic_ack_eth[1] =
150                                 cpu_to_be32(e->atomic_data);
151                         hwords += sizeof(ohdr->u.at) / sizeof(u32);
152                         bth2 = e->psn;
153                         e->sent = 1;
154                 }
155                 bth0 = qp->s_ack_state << 24;
156                 break;
157
158         case OP(RDMA_READ_RESPONSE_FIRST):
159                 qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
160                 /* FALLTHROUGH */
161         case OP(RDMA_READ_RESPONSE_MIDDLE):
162                 len = qp->s_ack_rdma_sge.sge.sge_length;
163                 if (len > pmtu)
164                         len = pmtu;
165                 else {
166                         ohdr->u.aeth = ipath_compute_aeth(qp);
167                         hwords++;
168                         qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
169                         qp->s_ack_queue[qp->s_tail_ack_queue].sent = 1;
170                 }
171                 bth0 = qp->s_ack_state << 24;
172                 bth2 = qp->s_ack_rdma_psn++ & IPATH_PSN_MASK;
173                 break;
174
175         default:
176         normal:
177                 /*
178                  * Send a regular ACK.
179                  * Set the s_ack_state so we wait until after sending
180                  * the ACK before setting s_ack_state to ACKNOWLEDGE
181                  * (see above).
182                  */
183                 qp->s_ack_state = OP(SEND_ONLY);
184                 qp->s_flags &= ~IPATH_S_ACK_PENDING;
185                 qp->s_cur_sge = NULL;
186                 if (qp->s_nak_state)
187                         ohdr->u.aeth =
188                                 cpu_to_be32((qp->r_msn & IPATH_MSN_MASK) |
189                                             (qp->s_nak_state <<
190                                              IPATH_AETH_CREDIT_SHIFT));
191                 else
192                         ohdr->u.aeth = ipath_compute_aeth(qp);
193                 hwords++;
194                 len = 0;
195                 bth0 = OP(ACKNOWLEDGE) << 24;
196                 bth2 = qp->s_ack_psn & IPATH_PSN_MASK;
197         }
198         qp->s_hdrwords = hwords;
199         qp->s_cur_size = len;
200         ipath_make_ruc_header(dev, qp, ohdr, bth0, bth2);
201         return 1;
202
203 bail:
204         return 0;
205 }
206
207 /**
208  * ipath_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
209  * @qp: a pointer to the QP
210  *
211  * Return 1 if constructed; otherwise, return 0.
212  */
213 int ipath_make_rc_req(struct ipath_qp *qp)
214 {
215         struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
216         struct ipath_other_headers *ohdr;
217         struct ipath_sge_state *ss;
218         struct ipath_swqe *wqe;
219         u32 hwords;
220         u32 len;
221         u32 bth0;
222         u32 bth2;
223         u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
224         char newreq;
225         unsigned long flags;
226         int ret = 0;
227
228         ohdr = &qp->s_hdr.u.oth;
229         if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
230                 ohdr = &qp->s_hdr.u.l.oth;
231
232         /*
233          * The lock is needed to synchronize between the sending tasklet,
234          * the receive interrupt handler, and timeout resends.
235          */
236         spin_lock_irqsave(&qp->s_lock, flags);
237
238         /* Sending responses has higher priority over sending requests. */
239         if ((qp->r_head_ack_queue != qp->s_tail_ack_queue ||
240              (qp->s_flags & IPATH_S_ACK_PENDING) ||
241              qp->s_ack_state != OP(ACKNOWLEDGE)) &&
242             ipath_make_rc_ack(dev, qp, ohdr, pmtu))
243                 goto done;
244
245         if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK)) {
246                 if (!(ib_ipath_state_ops[qp->state] & IPATH_FLUSH_SEND))
247                         goto bail;
248                 /* We are in the error state, flush the work request. */
249                 if (qp->s_last == qp->s_head)
250                         goto bail;
251                 /* If DMAs are in progress, we can't flush immediately. */
252                 if (atomic_read(&qp->s_dma_busy)) {
253                         qp->s_flags |= IPATH_S_WAIT_DMA;
254                         goto bail;
255                 }
256                 wqe = get_swqe_ptr(qp, qp->s_last);
257                 ipath_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
258                 goto done;
259         }
260
261         /* Leave BUSY set until RNR timeout. */
262         if (qp->s_rnr_timeout) {
263                 qp->s_flags |= IPATH_S_WAITING;
264                 goto bail;
265         }
266
267         /* header size in 32-bit words LRH+BTH = (8+12)/4. */
268         hwords = 5;
269         bth0 = 1 << 22; /* Set M bit */
270
271         /* Send a request. */
272         wqe = get_swqe_ptr(qp, qp->s_cur);
273         switch (qp->s_state) {
274         default:
275                 if (!(ib_ipath_state_ops[qp->state] &
276                     IPATH_PROCESS_NEXT_SEND_OK))
277                         goto bail;
278                 /*
279                  * Resend an old request or start a new one.
280                  *
281                  * We keep track of the current SWQE so that
282                  * we don't reset the "furthest progress" state
283                  * if we need to back up.
284                  */
285                 newreq = 0;
286                 if (qp->s_cur == qp->s_tail) {
287                         /* Check if send work queue is empty. */
288                         if (qp->s_tail == qp->s_head)
289                                 goto bail;
290                         /*
291                          * If a fence is requested, wait for previous
292                          * RDMA read and atomic operations to finish.
293                          */
294                         if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
295                             qp->s_num_rd_atomic) {
296                                 qp->s_flags |= IPATH_S_FENCE_PENDING;
297                                 goto bail;
298                         }
299                         wqe->psn = qp->s_next_psn;
300                         newreq = 1;
301                 }
302                 /*
303                  * Note that we have to be careful not to modify the
304                  * original work request since we may need to resend
305                  * it.
306                  */
307                 len = wqe->length;
308                 ss = &qp->s_sge;
309                 bth2 = 0;
310                 switch (wqe->wr.opcode) {
311                 case IB_WR_SEND:
312                 case IB_WR_SEND_WITH_IMM:
313                         /* If no credit, return. */
314                         if (qp->s_lsn != (u32) -1 &&
315                             ipath_cmp24(wqe->ssn, qp->s_lsn + 1) > 0) {
316                                 qp->s_flags |= IPATH_S_WAIT_SSN_CREDIT;
317                                 goto bail;
318                         }
319                         wqe->lpsn = wqe->psn;
320                         if (len > pmtu) {
321                                 wqe->lpsn += (len - 1) / pmtu;
322                                 qp->s_state = OP(SEND_FIRST);
323                                 len = pmtu;
324                                 break;
325                         }
326                         if (wqe->wr.opcode == IB_WR_SEND)
327                                 qp->s_state = OP(SEND_ONLY);
328                         else {
329                                 qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
330                                 /* Immediate data comes after the BTH */
331                                 ohdr->u.imm_data = wqe->wr.ex.imm_data;
332                                 hwords += 1;
333                         }
334                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
335                                 bth0 |= 1 << 23;
336                         bth2 = 1 << 31; /* Request ACK. */
337                         if (++qp->s_cur == qp->s_size)
338                                 qp->s_cur = 0;
339                         break;
340
341                 case IB_WR_RDMA_WRITE:
342                         if (newreq && qp->s_lsn != (u32) -1)
343                                 qp->s_lsn++;
344                         /* FALLTHROUGH */
345                 case IB_WR_RDMA_WRITE_WITH_IMM:
346                         /* If no credit, return. */
347                         if (qp->s_lsn != (u32) -1 &&
348                             ipath_cmp24(wqe->ssn, qp->s_lsn + 1) > 0) {
349                                 qp->s_flags |= IPATH_S_WAIT_SSN_CREDIT;
350                                 goto bail;
351                         }
352                         ohdr->u.rc.reth.vaddr =
353                                 cpu_to_be64(wqe->wr.wr.rdma.remote_addr);
354                         ohdr->u.rc.reth.rkey =
355                                 cpu_to_be32(wqe->wr.wr.rdma.rkey);
356                         ohdr->u.rc.reth.length = cpu_to_be32(len);
357                         hwords += sizeof(struct ib_reth) / sizeof(u32);
358                         wqe->lpsn = wqe->psn;
359                         if (len > pmtu) {
360                                 wqe->lpsn += (len - 1) / pmtu;
361                                 qp->s_state = OP(RDMA_WRITE_FIRST);
362                                 len = pmtu;
363                                 break;
364                         }
365                         if (wqe->wr.opcode == IB_WR_RDMA_WRITE)
366                                 qp->s_state = OP(RDMA_WRITE_ONLY);
367                         else {
368                                 qp->s_state =
369                                         OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
370                                 /* Immediate data comes after RETH */
371                                 ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
372                                 hwords += 1;
373                                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
374                                         bth0 |= 1 << 23;
375                         }
376                         bth2 = 1 << 31; /* Request ACK. */
377                         if (++qp->s_cur == qp->s_size)
378                                 qp->s_cur = 0;
379                         break;
380
381                 case IB_WR_RDMA_READ:
382                         /*
383                          * Don't allow more operations to be started
384                          * than the QP limits allow.
385                          */
386                         if (newreq) {
387                                 if (qp->s_num_rd_atomic >=
388                                     qp->s_max_rd_atomic) {
389                                         qp->s_flags |= IPATH_S_RDMAR_PENDING;
390                                         goto bail;
391                                 }
392                                 qp->s_num_rd_atomic++;
393                                 if (qp->s_lsn != (u32) -1)
394                                         qp->s_lsn++;
395                                 /*
396                                  * Adjust s_next_psn to count the
397                                  * expected number of responses.
398                                  */
399                                 if (len > pmtu)
400                                         qp->s_next_psn += (len - 1) / pmtu;
401                                 wqe->lpsn = qp->s_next_psn++;
402                         }
403                         ohdr->u.rc.reth.vaddr =
404                                 cpu_to_be64(wqe->wr.wr.rdma.remote_addr);
405                         ohdr->u.rc.reth.rkey =
406                                 cpu_to_be32(wqe->wr.wr.rdma.rkey);
407                         ohdr->u.rc.reth.length = cpu_to_be32(len);
408                         qp->s_state = OP(RDMA_READ_REQUEST);
409                         hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
410                         ss = NULL;
411                         len = 0;
412                         if (++qp->s_cur == qp->s_size)
413                                 qp->s_cur = 0;
414                         break;
415
416                 case IB_WR_ATOMIC_CMP_AND_SWP:
417                 case IB_WR_ATOMIC_FETCH_AND_ADD:
418                         /*
419                          * Don't allow more operations to be started
420                          * than the QP limits allow.
421                          */
422                         if (newreq) {
423                                 if (qp->s_num_rd_atomic >=
424                                     qp->s_max_rd_atomic) {
425                                         qp->s_flags |= IPATH_S_RDMAR_PENDING;
426                                         goto bail;
427                                 }
428                                 qp->s_num_rd_atomic++;
429                                 if (qp->s_lsn != (u32) -1)
430                                         qp->s_lsn++;
431                                 wqe->lpsn = wqe->psn;
432                         }
433                         if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP) {
434                                 qp->s_state = OP(COMPARE_SWAP);
435                                 ohdr->u.atomic_eth.swap_data = cpu_to_be64(
436                                         wqe->wr.wr.atomic.swap);
437                                 ohdr->u.atomic_eth.compare_data = cpu_to_be64(
438                                         wqe->wr.wr.atomic.compare_add);
439                         } else {
440                                 qp->s_state = OP(FETCH_ADD);
441                                 ohdr->u.atomic_eth.swap_data = cpu_to_be64(
442                                         wqe->wr.wr.atomic.compare_add);
443                                 ohdr->u.atomic_eth.compare_data = 0;
444                         }
445                         ohdr->u.atomic_eth.vaddr[0] = cpu_to_be32(
446                                 wqe->wr.wr.atomic.remote_addr >> 32);
447                         ohdr->u.atomic_eth.vaddr[1] = cpu_to_be32(
448                                 wqe->wr.wr.atomic.remote_addr);
449                         ohdr->u.atomic_eth.rkey = cpu_to_be32(
450                                 wqe->wr.wr.atomic.rkey);
451                         hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
452                         ss = NULL;
453                         len = 0;
454                         if (++qp->s_cur == qp->s_size)
455                                 qp->s_cur = 0;
456                         break;
457
458                 default:
459                         goto bail;
460                 }
461                 qp->s_sge.sge = wqe->sg_list[0];
462                 qp->s_sge.sg_list = wqe->sg_list + 1;
463                 qp->s_sge.num_sge = wqe->wr.num_sge;
464                 qp->s_len = wqe->length;
465                 if (newreq) {
466                         qp->s_tail++;
467                         if (qp->s_tail >= qp->s_size)
468                                 qp->s_tail = 0;
469                 }
470                 bth2 |= qp->s_psn & IPATH_PSN_MASK;
471                 if (wqe->wr.opcode == IB_WR_RDMA_READ)
472                         qp->s_psn = wqe->lpsn + 1;
473                 else {
474                         qp->s_psn++;
475                         if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
476                                 qp->s_next_psn = qp->s_psn;
477                 }
478                 /*
479                  * Put the QP on the pending list so lost ACKs will cause
480                  * a retry.  More than one request can be pending so the
481                  * QP may already be on the dev->pending list.
482                  */
483                 spin_lock(&dev->pending_lock);
484                 if (list_empty(&qp->timerwait))
485                         list_add_tail(&qp->timerwait,
486                                       &dev->pending[dev->pending_index]);
487                 spin_unlock(&dev->pending_lock);
488                 break;
489
490         case OP(RDMA_READ_RESPONSE_FIRST):
491                 /*
492                  * This case can only happen if a send is restarted.
493                  * See ipath_restart_rc().
494                  */
495                 ipath_init_restart(qp, wqe);
496                 /* FALLTHROUGH */
497         case OP(SEND_FIRST):
498                 qp->s_state = OP(SEND_MIDDLE);
499                 /* FALLTHROUGH */
500         case OP(SEND_MIDDLE):
501                 bth2 = qp->s_psn++ & IPATH_PSN_MASK;
502                 if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
503                         qp->s_next_psn = qp->s_psn;
504                 ss = &qp->s_sge;
505                 len = qp->s_len;
506                 if (len > pmtu) {
507                         len = pmtu;
508                         break;
509                 }
510                 if (wqe->wr.opcode == IB_WR_SEND)
511                         qp->s_state = OP(SEND_LAST);
512                 else {
513                         qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
514                         /* Immediate data comes after the BTH */
515                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
516                         hwords += 1;
517                 }
518                 if (wqe->wr.send_flags & IB_SEND_SOLICITED)
519                         bth0 |= 1 << 23;
520                 bth2 |= 1 << 31;        /* Request ACK. */
521                 qp->s_cur++;
522                 if (qp->s_cur >= qp->s_size)
523                         qp->s_cur = 0;
524                 break;
525
526         case OP(RDMA_READ_RESPONSE_LAST):
527                 /*
528                  * This case can only happen if a RDMA write is restarted.
529                  * See ipath_restart_rc().
530                  */
531                 ipath_init_restart(qp, wqe);
532                 /* FALLTHROUGH */
533         case OP(RDMA_WRITE_FIRST):
534                 qp->s_state = OP(RDMA_WRITE_MIDDLE);
535                 /* FALLTHROUGH */
536         case OP(RDMA_WRITE_MIDDLE):
537                 bth2 = qp->s_psn++ & IPATH_PSN_MASK;
538                 if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
539                         qp->s_next_psn = qp->s_psn;
540                 ss = &qp->s_sge;
541                 len = qp->s_len;
542                 if (len > pmtu) {
543                         len = pmtu;
544                         break;
545                 }
546                 if (wqe->wr.opcode == IB_WR_RDMA_WRITE)
547                         qp->s_state = OP(RDMA_WRITE_LAST);
548                 else {
549                         qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
550                         /* Immediate data comes after the BTH */
551                         ohdr->u.imm_data = wqe->wr.ex.imm_data;
552                         hwords += 1;
553                         if (wqe->wr.send_flags & IB_SEND_SOLICITED)
554                                 bth0 |= 1 << 23;
555                 }
556                 bth2 |= 1 << 31;        /* Request ACK. */
557                 qp->s_cur++;
558                 if (qp->s_cur >= qp->s_size)
559                         qp->s_cur = 0;
560                 break;
561
562         case OP(RDMA_READ_RESPONSE_MIDDLE):
563                 /*
564                  * This case can only happen if a RDMA read is restarted.
565                  * See ipath_restart_rc().
566                  */
567                 ipath_init_restart(qp, wqe);
568                 len = ((qp->s_psn - wqe->psn) & IPATH_PSN_MASK) * pmtu;
569                 ohdr->u.rc.reth.vaddr =
570                         cpu_to_be64(wqe->wr.wr.rdma.remote_addr + len);
571                 ohdr->u.rc.reth.rkey =
572                         cpu_to_be32(wqe->wr.wr.rdma.rkey);
573                 ohdr->u.rc.reth.length = cpu_to_be32(qp->s_len);
574                 qp->s_state = OP(RDMA_READ_REQUEST);
575                 hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
576                 bth2 = qp->s_psn++ & IPATH_PSN_MASK;
577                 if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
578                         qp->s_next_psn = qp->s_psn;
579                 ss = NULL;
580                 len = 0;
581                 qp->s_cur++;
582                 if (qp->s_cur == qp->s_size)
583                         qp->s_cur = 0;
584                 break;
585         }
586         if (ipath_cmp24(qp->s_psn, qp->s_last_psn + IPATH_PSN_CREDIT - 1) >= 0)
587                 bth2 |= 1 << 31;        /* Request ACK. */
588         qp->s_len -= len;
589         qp->s_hdrwords = hwords;
590         qp->s_cur_sge = ss;
591         qp->s_cur_size = len;
592         ipath_make_ruc_header(dev, qp, ohdr, bth0 | (qp->s_state << 24), bth2);
593 done:
594         ret = 1;
595         goto unlock;
596
597 bail:
598         qp->s_flags &= ~IPATH_S_BUSY;
599 unlock:
600         spin_unlock_irqrestore(&qp->s_lock, flags);
601         return ret;
602 }
603
604 /**
605  * send_rc_ack - Construct an ACK packet and send it
606  * @qp: a pointer to the QP
607  *
608  * This is called from ipath_rc_rcv() and only uses the receive
609  * side QP state.
610  * Note that RDMA reads and atomics are handled in the
611  * send side QP state and tasklet.
612  */
613 static void send_rc_ack(struct ipath_qp *qp)
614 {
615         struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
616         struct ipath_devdata *dd;
617         u16 lrh0;
618         u32 bth0;
619         u32 hwords;
620         u32 __iomem *piobuf;
621         struct ipath_ib_header hdr;
622         struct ipath_other_headers *ohdr;
623         unsigned long flags;
624
625         spin_lock_irqsave(&qp->s_lock, flags);
626
627         /* Don't send ACK or NAK if a RDMA read or atomic is pending. */
628         if (qp->r_head_ack_queue != qp->s_tail_ack_queue ||
629             (qp->s_flags & IPATH_S_ACK_PENDING) ||
630             qp->s_ack_state != OP(ACKNOWLEDGE))
631                 goto queue_ack;
632
633         spin_unlock_irqrestore(&qp->s_lock, flags);
634
635         /* Don't try to send ACKs if the link isn't ACTIVE */
636         dd = dev->dd;
637         if (!(dd->ipath_flags & IPATH_LINKACTIVE))
638                 goto done;
639
640         piobuf = ipath_getpiobuf(dd, 0, NULL);
641         if (!piobuf) {
642                 /*
643                  * We are out of PIO buffers at the moment.
644                  * Pass responsibility for sending the ACK to the
645                  * send tasklet so that when a PIO buffer becomes
646                  * available, the ACK is sent ahead of other outgoing
647                  * packets.
648                  */
649                 spin_lock_irqsave(&qp->s_lock, flags);
650                 goto queue_ack;
651         }
652
653         /* Construct the header. */
654         ohdr = &hdr.u.oth;
655         lrh0 = IPATH_LRH_BTH;
656         /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4. */
657         hwords = 6;
658         if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
659                 hwords += ipath_make_grh(dev, &hdr.u.l.grh,
660                                          &qp->remote_ah_attr.grh,
661                                          hwords, 0);
662                 ohdr = &hdr.u.l.oth;
663                 lrh0 = IPATH_LRH_GRH;
664         }
665         /* read pkey_index w/o lock (its atomic) */
666         bth0 = ipath_get_pkey(dd, qp->s_pkey_index) |
667                 (OP(ACKNOWLEDGE) << 24) | (1 << 22);
668         if (qp->r_nak_state)
669                 ohdr->u.aeth = cpu_to_be32((qp->r_msn & IPATH_MSN_MASK) |
670                                             (qp->r_nak_state <<
671                                              IPATH_AETH_CREDIT_SHIFT));
672         else
673                 ohdr->u.aeth = ipath_compute_aeth(qp);
674         lrh0 |= qp->remote_ah_attr.sl << 4;
675         hdr.lrh[0] = cpu_to_be16(lrh0);
676         hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
677         hdr.lrh[2] = cpu_to_be16(hwords + SIZE_OF_CRC);
678         hdr.lrh[3] = cpu_to_be16(dd->ipath_lid);
679         ohdr->bth[0] = cpu_to_be32(bth0);
680         ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
681         ohdr->bth[2] = cpu_to_be32(qp->r_ack_psn & IPATH_PSN_MASK);
682
683         writeq(hwords + 1, piobuf);
684
685         if (dd->ipath_flags & IPATH_PIO_FLUSH_WC) {
686                 u32 *hdrp = (u32 *) &hdr;
687
688                 ipath_flush_wc();
689                 __iowrite32_copy(piobuf + 2, hdrp, hwords - 1);
690                 ipath_flush_wc();
691                 __raw_writel(hdrp[hwords - 1], piobuf + hwords + 1);
692         } else
693                 __iowrite32_copy(piobuf + 2, (u32 *) &hdr, hwords);
694
695         ipath_flush_wc();
696
697         dev->n_unicast_xmit++;
698         goto done;
699
700 queue_ack:
701         if (ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK) {
702                 dev->n_rc_qacks++;
703                 qp->s_flags |= IPATH_S_ACK_PENDING;
704                 qp->s_nak_state = qp->r_nak_state;
705                 qp->s_ack_psn = qp->r_ack_psn;
706
707                 /* Schedule the send tasklet. */
708                 ipath_schedule_send(qp);
709         }
710         spin_unlock_irqrestore(&qp->s_lock, flags);
711 done:
712         return;
713 }
714
715 /**
716  * reset_psn - reset the QP state to send starting from PSN
717  * @qp: the QP
718  * @psn: the packet sequence number to restart at
719  *
720  * This is called from ipath_rc_rcv() to process an incoming RC ACK
721  * for the given QP.
722  * Called at interrupt level with the QP s_lock held.
723  */
724 static void reset_psn(struct ipath_qp *qp, u32 psn)
725 {
726         u32 n = qp->s_last;
727         struct ipath_swqe *wqe = get_swqe_ptr(qp, n);
728         u32 opcode;
729
730         qp->s_cur = n;
731
732         /*
733          * If we are starting the request from the beginning,
734          * let the normal send code handle initialization.
735          */
736         if (ipath_cmp24(psn, wqe->psn) <= 0) {
737                 qp->s_state = OP(SEND_LAST);
738                 goto done;
739         }
740
741         /* Find the work request opcode corresponding to the given PSN. */
742         opcode = wqe->wr.opcode;
743         for (;;) {
744                 int diff;
745
746                 if (++n == qp->s_size)
747                         n = 0;
748                 if (n == qp->s_tail)
749                         break;
750                 wqe = get_swqe_ptr(qp, n);
751                 diff = ipath_cmp24(psn, wqe->psn);
752                 if (diff < 0)
753                         break;
754                 qp->s_cur = n;
755                 /*
756                  * If we are starting the request from the beginning,
757                  * let the normal send code handle initialization.
758                  */
759                 if (diff == 0) {
760                         qp->s_state = OP(SEND_LAST);
761                         goto done;
762                 }
763                 opcode = wqe->wr.opcode;
764         }
765
766         /*
767          * Set the state to restart in the middle of a request.
768          * Don't change the s_sge, s_cur_sge, or s_cur_size.
769          * See ipath_make_rc_req().
770          */
771         switch (opcode) {
772         case IB_WR_SEND:
773         case IB_WR_SEND_WITH_IMM:
774                 qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
775                 break;
776
777         case IB_WR_RDMA_WRITE:
778         case IB_WR_RDMA_WRITE_WITH_IMM:
779                 qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
780                 break;
781
782         case IB_WR_RDMA_READ:
783                 qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
784                 break;
785
786         default:
787                 /*
788                  * This case shouldn't happen since its only
789                  * one PSN per req.
790                  */
791                 qp->s_state = OP(SEND_LAST);
792         }
793 done:
794         qp->s_psn = psn;
795 }
796
797 /**
798  * ipath_restart_rc - back up requester to resend the last un-ACKed request
799  * @qp: the QP to restart
800  * @psn: packet sequence number for the request
801  * @wc: the work completion request
802  *
803  * The QP s_lock should be held and interrupts disabled.
804  */
805 void ipath_restart_rc(struct ipath_qp *qp, u32 psn)
806 {
807         struct ipath_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
808         struct ipath_ibdev *dev;
809
810         if (qp->s_retry == 0) {
811                 ipath_send_complete(qp, wqe, IB_WC_RETRY_EXC_ERR);
812                 ipath_error_qp(qp, IB_WC_WR_FLUSH_ERR);
813                 goto bail;
814         }
815         qp->s_retry--;
816
817         /*
818          * Remove the QP from the timeout queue.
819          * Note: it may already have been removed by ipath_ib_timer().
820          */
821         dev = to_idev(qp->ibqp.device);
822         spin_lock(&dev->pending_lock);
823         if (!list_empty(&qp->timerwait))
824                 list_del_init(&qp->timerwait);
825         if (!list_empty(&qp->piowait))
826                 list_del_init(&qp->piowait);
827         spin_unlock(&dev->pending_lock);
828
829         if (wqe->wr.opcode == IB_WR_RDMA_READ)
830                 dev->n_rc_resends++;
831         else
832                 dev->n_rc_resends += (qp->s_psn - psn) & IPATH_PSN_MASK;
833
834         reset_psn(qp, psn);
835         ipath_schedule_send(qp);
836
837 bail:
838         return;
839 }
840
841 static inline void update_last_psn(struct ipath_qp *qp, u32 psn)
842 {
843         qp->s_last_psn = psn;
844 }
845
846 /**
847  * do_rc_ack - process an incoming RC ACK
848  * @qp: the QP the ACK came in on
849  * @psn: the packet sequence number of the ACK
850  * @opcode: the opcode of the request that resulted in the ACK
851  *
852  * This is called from ipath_rc_rcv_resp() to process an incoming RC ACK
853  * for the given QP.
854  * Called at interrupt level with the QP s_lock held and interrupts disabled.
855  * Returns 1 if OK, 0 if current operation should be aborted (NAK).
856  */
857 static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode,
858                      u64 val)
859 {
860         struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
861         struct ib_wc wc;
862         enum ib_wc_status status;
863         struct ipath_swqe *wqe;
864         int ret = 0;
865         u32 ack_psn;
866         int diff;
867
868         /*
869          * Remove the QP from the timeout queue (or RNR timeout queue).
870          * If ipath_ib_timer() has already removed it,
871          * it's OK since we hold the QP s_lock and ipath_restart_rc()
872          * just won't find anything to restart if we ACK everything.
873          */
874         spin_lock(&dev->pending_lock);
875         if (!list_empty(&qp->timerwait))
876                 list_del_init(&qp->timerwait);
877         spin_unlock(&dev->pending_lock);
878
879         /*
880          * Note that NAKs implicitly ACK outstanding SEND and RDMA write
881          * requests and implicitly NAK RDMA read and atomic requests issued
882          * before the NAK'ed request.  The MSN won't include the NAK'ed
883          * request but will include an ACK'ed request(s).
884          */
885         ack_psn = psn;
886         if (aeth >> 29)
887                 ack_psn--;
888         wqe = get_swqe_ptr(qp, qp->s_last);
889
890         /*
891          * The MSN might be for a later WQE than the PSN indicates so
892          * only complete WQEs that the PSN finishes.
893          */
894         while ((diff = ipath_cmp24(ack_psn, wqe->lpsn)) >= 0) {
895                 /*
896                  * RDMA_READ_RESPONSE_ONLY is a special case since
897                  * we want to generate completion events for everything
898                  * before the RDMA read, copy the data, then generate
899                  * the completion for the read.
900                  */
901                 if (wqe->wr.opcode == IB_WR_RDMA_READ &&
902                     opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
903                     diff == 0) {
904                         ret = 1;
905                         goto bail;
906                 }
907                 /*
908                  * If this request is a RDMA read or atomic, and the ACK is
909                  * for a later operation, this ACK NAKs the RDMA read or
910                  * atomic.  In other words, only a RDMA_READ_LAST or ONLY
911                  * can ACK a RDMA read and likewise for atomic ops.  Note
912                  * that the NAK case can only happen if relaxed ordering is
913                  * used and requests are sent after an RDMA read or atomic
914                  * is sent but before the response is received.
915                  */
916                 if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
917                      (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
918                     ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
919                       wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
920                      (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0))) {
921                         /*
922                          * The last valid PSN seen is the previous
923                          * request's.
924                          */
925                         update_last_psn(qp, wqe->psn - 1);
926                         /* Retry this request. */
927                         ipath_restart_rc(qp, wqe->psn);
928                         /*
929                          * No need to process the ACK/NAK since we are
930                          * restarting an earlier request.
931                          */
932                         goto bail;
933                 }
934                 if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
935                     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
936                         *(u64 *) wqe->sg_list[0].vaddr = val;
937                 if (qp->s_num_rd_atomic &&
938                     (wqe->wr.opcode == IB_WR_RDMA_READ ||
939                      wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
940                      wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
941                         qp->s_num_rd_atomic--;
942                         /* Restart sending task if fence is complete */
943                         if (((qp->s_flags & IPATH_S_FENCE_PENDING) &&
944                              !qp->s_num_rd_atomic) ||
945                             qp->s_flags & IPATH_S_RDMAR_PENDING)
946                                 ipath_schedule_send(qp);
947                 }
948                 /* Post a send completion queue entry if requested. */
949                 if (!(qp->s_flags & IPATH_S_SIGNAL_REQ_WR) ||
950                     (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
951                         memset(&wc, 0, sizeof wc);
952                         wc.wr_id = wqe->wr.wr_id;
953                         wc.status = IB_WC_SUCCESS;
954                         wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
955                         wc.byte_len = wqe->length;
956                         wc.qp = &qp->ibqp;
957                         wc.src_qp = qp->remote_qpn;
958                         wc.slid = qp->remote_ah_attr.dlid;
959                         wc.sl = qp->remote_ah_attr.sl;
960                         ipath_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 0);
961                 }
962                 qp->s_retry = qp->s_retry_cnt;
963                 /*
964                  * If we are completing a request which is in the process of
965                  * being resent, we can stop resending it since we know the
966                  * responder has already seen it.
967                  */
968                 if (qp->s_last == qp->s_cur) {
969                         if (++qp->s_cur >= qp->s_size)
970                                 qp->s_cur = 0;
971                         qp->s_last = qp->s_cur;
972                         if (qp->s_last == qp->s_tail)
973                                 break;
974                         wqe = get_swqe_ptr(qp, qp->s_cur);
975                         qp->s_state = OP(SEND_LAST);
976                         qp->s_psn = wqe->psn;
977                 } else {
978                         if (++qp->s_last >= qp->s_size)
979                                 qp->s_last = 0;
980                         if (qp->state == IB_QPS_SQD && qp->s_last == qp->s_cur)
981                                 qp->s_draining = 0;
982                         if (qp->s_last == qp->s_tail)
983                                 break;
984                         wqe = get_swqe_ptr(qp, qp->s_last);
985                 }
986         }
987
988         switch (aeth >> 29) {
989         case 0:         /* ACK */
990                 dev->n_rc_acks++;
991                 /* If this is a partial ACK, reset the retransmit timer. */
992                 if (qp->s_last != qp->s_tail) {
993                         spin_lock(&dev->pending_lock);
994                         if (list_empty(&qp->timerwait))
995                                 list_add_tail(&qp->timerwait,
996                                         &dev->pending[dev->pending_index]);
997                         spin_unlock(&dev->pending_lock);
998                         /*
999                          * If we get a partial ACK for a resent operation,
1000                          * we can stop resending the earlier packets and
1001                          * continue with the next packet the receiver wants.
1002                          */
1003                         if (ipath_cmp24(qp->s_psn, psn) <= 0) {
1004                                 reset_psn(qp, psn + 1);
1005                                 ipath_schedule_send(qp);
1006                         }
1007                 } else if (ipath_cmp24(qp->s_psn, psn) <= 0) {
1008                         qp->s_state = OP(SEND_LAST);
1009                         qp->s_psn = psn + 1;
1010                 }
1011                 ipath_get_credit(qp, aeth);
1012                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1013                 qp->s_retry = qp->s_retry_cnt;
1014                 update_last_psn(qp, psn);
1015                 ret = 1;
1016                 goto bail;
1017
1018         case 1:         /* RNR NAK */
1019                 dev->n_rnr_naks++;
1020                 if (qp->s_last == qp->s_tail)
1021                         goto bail;
1022                 if (qp->s_rnr_retry == 0) {
1023                         status = IB_WC_RNR_RETRY_EXC_ERR;
1024                         goto class_b;
1025                 }
1026                 if (qp->s_rnr_retry_cnt < 7)
1027                         qp->s_rnr_retry--;
1028
1029                 /* The last valid PSN is the previous PSN. */
1030                 update_last_psn(qp, psn - 1);
1031
1032                 if (wqe->wr.opcode == IB_WR_RDMA_READ)
1033                         dev->n_rc_resends++;
1034                 else
1035                         dev->n_rc_resends +=
1036                                 (qp->s_psn - psn) & IPATH_PSN_MASK;
1037
1038                 reset_psn(qp, psn);
1039
1040                 qp->s_rnr_timeout =
1041                         ib_ipath_rnr_table[(aeth >> IPATH_AETH_CREDIT_SHIFT) &
1042                                            IPATH_AETH_CREDIT_MASK];
1043                 ipath_insert_rnr_queue(qp);
1044                 ipath_schedule_send(qp);
1045                 goto bail;
1046
1047         case 3:         /* NAK */
1048                 if (qp->s_last == qp->s_tail)
1049                         goto bail;
1050                 /* The last valid PSN is the previous PSN. */
1051                 update_last_psn(qp, psn - 1);
1052                 switch ((aeth >> IPATH_AETH_CREDIT_SHIFT) &
1053                         IPATH_AETH_CREDIT_MASK) {
1054                 case 0: /* PSN sequence error */
1055                         dev->n_seq_naks++;
1056                         /*
1057                          * Back up to the responder's expected PSN.
1058                          * Note that we might get a NAK in the middle of an
1059                          * RDMA READ response which terminates the RDMA
1060                          * READ.
1061                          */
1062                         ipath_restart_rc(qp, psn);
1063                         break;
1064
1065                 case 1: /* Invalid Request */
1066                         status = IB_WC_REM_INV_REQ_ERR;
1067                         dev->n_other_naks++;
1068                         goto class_b;
1069
1070                 case 2: /* Remote Access Error */
1071                         status = IB_WC_REM_ACCESS_ERR;
1072                         dev->n_other_naks++;
1073                         goto class_b;
1074
1075                 case 3: /* Remote Operation Error */
1076                         status = IB_WC_REM_OP_ERR;
1077                         dev->n_other_naks++;
1078                 class_b:
1079                         ipath_send_complete(qp, wqe, status);
1080                         ipath_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1081                         break;
1082
1083                 default:
1084                         /* Ignore other reserved NAK error codes */
1085                         goto reserved;
1086                 }
1087                 qp->s_rnr_retry = qp->s_rnr_retry_cnt;
1088                 goto bail;
1089
1090         default:                /* 2: reserved */
1091         reserved:
1092                 /* Ignore reserved NAK codes. */
1093                 goto bail;
1094         }
1095
1096 bail:
1097         return ret;
1098 }
1099
1100 /**
1101  * ipath_rc_rcv_resp - process an incoming RC response packet
1102  * @dev: the device this packet came in on
1103  * @ohdr: the other headers for this packet
1104  * @data: the packet data
1105  * @tlen: the packet length
1106  * @qp: the QP for this packet
1107  * @opcode: the opcode for this packet
1108  * @psn: the packet sequence number for this packet
1109  * @hdrsize: the header length
1110  * @pmtu: the path MTU
1111  * @header_in_data: true if part of the header data is in the data buffer
1112  *
1113  * This is called from ipath_rc_rcv() to process an incoming RC response
1114  * packet for the given QP.
1115  * Called at interrupt level.
1116  */
1117 static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
1118                                      struct ipath_other_headers *ohdr,
1119                                      void *data, u32 tlen,
1120                                      struct ipath_qp *qp,
1121                                      u32 opcode,
1122                                      u32 psn, u32 hdrsize, u32 pmtu,
1123                                      int header_in_data)
1124 {
1125         struct ipath_swqe *wqe;
1126         enum ib_wc_status status;
1127         unsigned long flags;
1128         int diff;
1129         u32 pad;
1130         u32 aeth;
1131         u64 val;
1132
1133         spin_lock_irqsave(&qp->s_lock, flags);
1134
1135         /* Double check we can process this now that we hold the s_lock. */
1136         if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1137                 goto ack_done;
1138
1139         /* Ignore invalid responses. */
1140         if (ipath_cmp24(psn, qp->s_next_psn) >= 0)
1141                 goto ack_done;
1142
1143         /* Ignore duplicate responses. */
1144         diff = ipath_cmp24(psn, qp->s_last_psn);
1145         if (unlikely(diff <= 0)) {
1146                 /* Update credits for "ghost" ACKs */
1147                 if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
1148                         if (!header_in_data)
1149                                 aeth = be32_to_cpu(ohdr->u.aeth);
1150                         else {
1151                                 aeth = be32_to_cpu(((__be32 *) data)[0]);
1152                                 data += sizeof(__be32);
1153                         }
1154                         if ((aeth >> 29) == 0)
1155                                 ipath_get_credit(qp, aeth);
1156                 }
1157                 goto ack_done;
1158         }
1159
1160         if (unlikely(qp->s_last == qp->s_tail))
1161                 goto ack_done;
1162         wqe = get_swqe_ptr(qp, qp->s_last);
1163         status = IB_WC_SUCCESS;
1164
1165         switch (opcode) {
1166         case OP(ACKNOWLEDGE):
1167         case OP(ATOMIC_ACKNOWLEDGE):
1168         case OP(RDMA_READ_RESPONSE_FIRST):
1169                 if (!header_in_data)
1170                         aeth = be32_to_cpu(ohdr->u.aeth);
1171                 else {
1172                         aeth = be32_to_cpu(((__be32 *) data)[0]);
1173                         data += sizeof(__be32);
1174                 }
1175                 if (opcode == OP(ATOMIC_ACKNOWLEDGE)) {
1176                         if (!header_in_data) {
1177                                 __be32 *p = ohdr->u.at.atomic_ack_eth;
1178
1179                                 val = ((u64) be32_to_cpu(p[0]) << 32) |
1180                                         be32_to_cpu(p[1]);
1181                         } else
1182                                 val = be64_to_cpu(((__be64 *) data)[0]);
1183                 } else
1184                         val = 0;
1185                 if (!do_rc_ack(qp, aeth, psn, opcode, val) ||
1186                     opcode != OP(RDMA_READ_RESPONSE_FIRST))
1187                         goto ack_done;
1188                 hdrsize += 4;
1189                 wqe = get_swqe_ptr(qp, qp->s_last);
1190                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1191                         goto ack_op_err;
1192                 /*
1193                  * If this is a response to a resent RDMA read, we
1194                  * have to be careful to copy the data to the right
1195                  * location.
1196                  */
1197                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1198                                                   wqe, psn, pmtu);
1199                 goto read_middle;
1200
1201         case OP(RDMA_READ_RESPONSE_MIDDLE):
1202                 /* no AETH, no ACK */
1203                 if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
1204                         dev->n_rdma_seq++;
1205                         ipath_restart_rc(qp, qp->s_last_psn + 1);
1206                         goto ack_done;
1207                 }
1208                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1209                         goto ack_op_err;
1210         read_middle:
1211                 if (unlikely(tlen != (hdrsize + pmtu + 4)))
1212                         goto ack_len_err;
1213                 if (unlikely(pmtu >= qp->s_rdma_read_len))
1214                         goto ack_len_err;
1215
1216                 /* We got a response so update the timeout. */
1217                 spin_lock(&dev->pending_lock);
1218                 if (qp->s_rnr_timeout == 0 && !list_empty(&qp->timerwait))
1219                         list_move_tail(&qp->timerwait,
1220                                        &dev->pending[dev->pending_index]);
1221                 spin_unlock(&dev->pending_lock);
1222
1223                 if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
1224                         qp->s_retry = qp->s_retry_cnt;
1225
1226                 /*
1227                  * Update the RDMA receive state but do the copy w/o
1228                  * holding the locks and blocking interrupts.
1229                  */
1230                 qp->s_rdma_read_len -= pmtu;
1231                 update_last_psn(qp, psn);
1232                 spin_unlock_irqrestore(&qp->s_lock, flags);
1233                 ipath_copy_sge(&qp->s_rdma_read_sge, data, pmtu);
1234                 goto bail;
1235
1236         case OP(RDMA_READ_RESPONSE_ONLY):
1237                 if (!header_in_data)
1238                         aeth = be32_to_cpu(ohdr->u.aeth);
1239                 else
1240                         aeth = be32_to_cpu(((__be32 *) data)[0]);
1241                 if (!do_rc_ack(qp, aeth, psn, opcode, 0))
1242                         goto ack_done;
1243                 /* Get the number of bytes the message was padded by. */
1244                 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1245                 /*
1246                  * Check that the data size is >= 0 && <= pmtu.
1247                  * Remember to account for the AETH header (4) and
1248                  * ICRC (4).
1249                  */
1250                 if (unlikely(tlen < (hdrsize + pad + 8)))
1251                         goto ack_len_err;
1252                 /*
1253                  * If this is a response to a resent RDMA read, we
1254                  * have to be careful to copy the data to the right
1255                  * location.
1256                  */
1257                 wqe = get_swqe_ptr(qp, qp->s_last);
1258                 qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
1259                                                   wqe, psn, pmtu);
1260                 goto read_last;
1261
1262         case OP(RDMA_READ_RESPONSE_LAST):
1263                 /* ACKs READ req. */
1264                 if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
1265                         dev->n_rdma_seq++;
1266                         ipath_restart_rc(qp, qp->s_last_psn + 1);
1267                         goto ack_done;
1268                 }
1269                 if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
1270                         goto ack_op_err;
1271                 /* Get the number of bytes the message was padded by. */
1272                 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1273                 /*
1274                  * Check that the data size is >= 1 && <= pmtu.
1275                  * Remember to account for the AETH header (4) and
1276                  * ICRC (4).
1277                  */
1278                 if (unlikely(tlen <= (hdrsize + pad + 8)))
1279                         goto ack_len_err;
1280         read_last:
1281                 tlen -= hdrsize + pad + 8;
1282                 if (unlikely(tlen != qp->s_rdma_read_len))
1283                         goto ack_len_err;
1284                 if (!header_in_data)
1285                         aeth = be32_to_cpu(ohdr->u.aeth);
1286                 else {
1287                         aeth = be32_to_cpu(((__be32 *) data)[0]);
1288                         data += sizeof(__be32);
1289                 }
1290                 ipath_copy_sge(&qp->s_rdma_read_sge, data, tlen);
1291                 (void) do_rc_ack(qp, aeth, psn,
1292                                  OP(RDMA_READ_RESPONSE_LAST), 0);
1293                 goto ack_done;
1294         }
1295
1296 ack_op_err:
1297         status = IB_WC_LOC_QP_OP_ERR;
1298         goto ack_err;
1299
1300 ack_len_err:
1301         status = IB_WC_LOC_LEN_ERR;
1302 ack_err:
1303         ipath_send_complete(qp, wqe, status);
1304         ipath_error_qp(qp, IB_WC_WR_FLUSH_ERR);
1305 ack_done:
1306         spin_unlock_irqrestore(&qp->s_lock, flags);
1307 bail:
1308         return;
1309 }
1310
1311 /**
1312  * ipath_rc_rcv_error - process an incoming duplicate or error RC packet
1313  * @dev: the device this packet came in on
1314  * @ohdr: the other headers for this packet
1315  * @data: the packet data
1316  * @qp: the QP for this packet
1317  * @opcode: the opcode for this packet
1318  * @psn: the packet sequence number for this packet
1319  * @diff: the difference between the PSN and the expected PSN
1320  * @header_in_data: true if part of the header data is in the data buffer
1321  *
1322  * This is called from ipath_rc_rcv() to process an unexpected
1323  * incoming RC packet for the given QP.
1324  * Called at interrupt level.
1325  * Return 1 if no more processing is needed; otherwise return 0 to
1326  * schedule a response to be sent.
1327  */
1328 static inline int ipath_rc_rcv_error(struct ipath_ibdev *dev,
1329                                      struct ipath_other_headers *ohdr,
1330                                      void *data,
1331                                      struct ipath_qp *qp,
1332                                      u32 opcode,
1333                                      u32 psn,
1334                                      int diff,
1335                                      int header_in_data)
1336 {
1337         struct ipath_ack_entry *e;
1338         u8 i, prev;
1339         int old_req;
1340         unsigned long flags;
1341
1342         if (diff > 0) {
1343                 /*
1344                  * Packet sequence error.
1345                  * A NAK will ACK earlier sends and RDMA writes.
1346                  * Don't queue the NAK if we already sent one.
1347                  */
1348                 if (!qp->r_nak_state) {
1349                         qp->r_nak_state = IB_NAK_PSN_ERROR;
1350                         /* Use the expected PSN. */
1351                         qp->r_ack_psn = qp->r_psn;
1352                         goto send_ack;
1353                 }
1354                 goto done;
1355         }
1356
1357         /*
1358          * Handle a duplicate request.  Don't re-execute SEND, RDMA
1359          * write or atomic op.  Don't NAK errors, just silently drop
1360          * the duplicate request.  Note that r_sge, r_len, and
1361          * r_rcv_len may be in use so don't modify them.
1362          *
1363          * We are supposed to ACK the earliest duplicate PSN but we
1364          * can coalesce an outstanding duplicate ACK.  We have to
1365          * send the earliest so that RDMA reads can be restarted at
1366          * the requester's expected PSN.
1367          *
1368          * First, find where this duplicate PSN falls within the
1369          * ACKs previously sent.
1370          */
1371         psn &= IPATH_PSN_MASK;
1372         e = NULL;
1373         old_req = 1;
1374
1375         spin_lock_irqsave(&qp->s_lock, flags);
1376         /* Double check we can process this now that we hold the s_lock. */
1377         if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1378                 goto unlock_done;
1379
1380         for (i = qp->r_head_ack_queue; ; i = prev) {
1381                 if (i == qp->s_tail_ack_queue)
1382                         old_req = 0;
1383                 if (i)
1384                         prev = i - 1;
1385                 else
1386                         prev = IPATH_MAX_RDMA_ATOMIC;
1387                 if (prev == qp->r_head_ack_queue) {
1388                         e = NULL;
1389                         break;
1390                 }
1391                 e = &qp->s_ack_queue[prev];
1392                 if (!e->opcode) {
1393                         e = NULL;
1394                         break;
1395                 }
1396                 if (ipath_cmp24(psn, e->psn) >= 0) {
1397                         if (prev == qp->s_tail_ack_queue)
1398                                 old_req = 0;
1399                         break;
1400                 }
1401         }
1402         switch (opcode) {
1403         case OP(RDMA_READ_REQUEST): {
1404                 struct ib_reth *reth;
1405                 u32 offset;
1406                 u32 len;
1407
1408                 /*
1409                  * If we didn't find the RDMA read 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 != OP(RDMA_READ_REQUEST) || old_req)
1414                         goto unlock_done;
1415                 /* RETH comes after BTH */
1416                 if (!header_in_data)
1417                         reth = &ohdr->u.rc.reth;
1418                 else {
1419                         reth = (struct ib_reth *)data;
1420                         data += sizeof(*reth);
1421                 }
1422                 /*
1423                  * Address range must be a subset of the original
1424                  * request and start on pmtu boundaries.
1425                  * We reuse the old ack_queue slot since the requester
1426                  * should not back up and request an earlier PSN for the
1427                  * same request.
1428                  */
1429                 offset = ((psn - e->psn) & IPATH_PSN_MASK) *
1430                         ib_mtu_enum_to_int(qp->path_mtu);
1431                 len = be32_to_cpu(reth->length);
1432                 if (unlikely(offset + len > e->rdma_sge.sge.sge_length))
1433                         goto unlock_done;
1434                 if (len != 0) {
1435                         u32 rkey = be32_to_cpu(reth->rkey);
1436                         u64 vaddr = be64_to_cpu(reth->vaddr);
1437                         int ok;
1438
1439                         ok = ipath_rkey_ok(qp, &e->rdma_sge,
1440                                            len, vaddr, rkey,
1441                                            IB_ACCESS_REMOTE_READ);
1442                         if (unlikely(!ok))
1443                                 goto unlock_done;
1444                 } else {
1445                         e->rdma_sge.sg_list = NULL;
1446                         e->rdma_sge.num_sge = 0;
1447                         e->rdma_sge.sge.mr = NULL;
1448                         e->rdma_sge.sge.vaddr = NULL;
1449                         e->rdma_sge.sge.length = 0;
1450                         e->rdma_sge.sge.sge_length = 0;
1451                 }
1452                 e->psn = psn;
1453                 qp->s_ack_state = OP(ACKNOWLEDGE);
1454                 qp->s_tail_ack_queue = prev;
1455                 break;
1456         }
1457
1458         case OP(COMPARE_SWAP):
1459         case OP(FETCH_ADD): {
1460                 /*
1461                  * If we didn't find the atomic request in the ack queue
1462                  * or the send tasklet is already backed up to send an
1463                  * earlier entry, we can ignore this request.
1464                  */
1465                 if (!e || e->opcode != (u8) opcode || old_req)
1466                         goto unlock_done;
1467                 qp->s_ack_state = OP(ACKNOWLEDGE);
1468                 qp->s_tail_ack_queue = prev;
1469                 break;
1470         }
1471
1472         default:
1473                 if (old_req)
1474                         goto unlock_done;
1475                 /*
1476                  * Resend the most recent ACK if this request is
1477                  * after all the previous RDMA reads and atomics.
1478                  */
1479                 if (i == qp->r_head_ack_queue) {
1480                         spin_unlock_irqrestore(&qp->s_lock, flags);
1481                         qp->r_nak_state = 0;
1482                         qp->r_ack_psn = qp->r_psn - 1;
1483                         goto send_ack;
1484                 }
1485                 /*
1486                  * Try to send a simple ACK to work around a Mellanox bug
1487                  * which doesn't accept a RDMA read response or atomic
1488                  * response as an ACK for earlier SENDs or RDMA writes.
1489                  */
1490                 if (qp->r_head_ack_queue == qp->s_tail_ack_queue &&
1491                     !(qp->s_flags & IPATH_S_ACK_PENDING) &&
1492                     qp->s_ack_state == OP(ACKNOWLEDGE)) {
1493                         spin_unlock_irqrestore(&qp->s_lock, flags);
1494                         qp->r_nak_state = 0;
1495                         qp->r_ack_psn = qp->s_ack_queue[i].psn - 1;
1496                         goto send_ack;
1497                 }
1498                 /*
1499                  * Resend the RDMA read or atomic op which
1500                  * ACKs this duplicate request.
1501                  */
1502                 qp->s_ack_state = OP(ACKNOWLEDGE);
1503                 qp->s_tail_ack_queue = i;
1504                 break;
1505         }
1506         qp->r_nak_state = 0;
1507         ipath_schedule_send(qp);
1508
1509 unlock_done:
1510         spin_unlock_irqrestore(&qp->s_lock, flags);
1511 done:
1512         return 1;
1513
1514 send_ack:
1515         return 0;
1516 }
1517
1518 void ipath_rc_error(struct ipath_qp *qp, enum ib_wc_status err)
1519 {
1520         unsigned long flags;
1521         int lastwqe;
1522
1523         spin_lock_irqsave(&qp->s_lock, flags);
1524         lastwqe = ipath_error_qp(qp, err);
1525         spin_unlock_irqrestore(&qp->s_lock, flags);
1526
1527         if (lastwqe) {
1528                 struct ib_event ev;
1529
1530                 ev.device = qp->ibqp.device;
1531                 ev.element.qp = &qp->ibqp;
1532                 ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
1533                 qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
1534         }
1535 }
1536
1537 static inline void ipath_update_ack_queue(struct ipath_qp *qp, unsigned n)
1538 {
1539         unsigned next;
1540
1541         next = n + 1;
1542         if (next > IPATH_MAX_RDMA_ATOMIC)
1543                 next = 0;
1544         if (n == qp->s_tail_ack_queue) {
1545                 qp->s_tail_ack_queue = next;
1546                 qp->s_ack_state = OP(ACKNOWLEDGE);
1547         }
1548 }
1549
1550 /**
1551  * ipath_rc_rcv - process an incoming RC packet
1552  * @dev: the device this packet came in on
1553  * @hdr: the header of this packet
1554  * @has_grh: true if the header has a GRH
1555  * @data: the packet data
1556  * @tlen: the packet length
1557  * @qp: the QP for this packet
1558  *
1559  * This is called from ipath_qp_rcv() to process an incoming RC packet
1560  * for the given QP.
1561  * Called at interrupt level.
1562  */
1563 void ipath_rc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
1564                   int has_grh, void *data, u32 tlen, struct ipath_qp *qp)
1565 {
1566         struct ipath_other_headers *ohdr;
1567         u32 opcode;
1568         u32 hdrsize;
1569         u32 psn;
1570         u32 pad;
1571         struct ib_wc wc;
1572         u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
1573         int diff;
1574         struct ib_reth *reth;
1575         int header_in_data;
1576         unsigned long flags;
1577
1578         /* Validate the SLID. See Ch. 9.6.1.5 */
1579         if (unlikely(be16_to_cpu(hdr->lrh[3]) != qp->remote_ah_attr.dlid))
1580                 goto done;
1581
1582         /* Check for GRH */
1583         if (!has_grh) {
1584                 ohdr = &hdr->u.oth;
1585                 hdrsize = 8 + 12;       /* LRH + BTH */
1586                 psn = be32_to_cpu(ohdr->bth[2]);
1587                 header_in_data = 0;
1588         } else {
1589                 ohdr = &hdr->u.l.oth;
1590                 hdrsize = 8 + 40 + 12;  /* LRH + GRH + BTH */
1591                 /*
1592                  * The header with GRH is 60 bytes and the core driver sets
1593                  * the eager header buffer size to 56 bytes so the last 4
1594                  * bytes of the BTH header (PSN) is in the data buffer.
1595                  */
1596                 header_in_data = dev->dd->ipath_rcvhdrentsize == 16;
1597                 if (header_in_data) {
1598                         psn = be32_to_cpu(((__be32 *) data)[0]);
1599                         data += sizeof(__be32);
1600                 } else
1601                         psn = be32_to_cpu(ohdr->bth[2]);
1602         }
1603
1604         /*
1605          * Process responses (ACKs) before anything else.  Note that the
1606          * packet sequence number will be for something in the send work
1607          * queue rather than the expected receive packet sequence number.
1608          * In other words, this QP is the requester.
1609          */
1610         opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
1611         if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
1612             opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
1613                 ipath_rc_rcv_resp(dev, ohdr, data, tlen, qp, opcode, psn,
1614                                   hdrsize, pmtu, header_in_data);
1615                 goto done;
1616         }
1617
1618         /* Compute 24 bits worth of difference. */
1619         diff = ipath_cmp24(psn, qp->r_psn);
1620         if (unlikely(diff)) {
1621                 if (ipath_rc_rcv_error(dev, ohdr, data, qp, opcode,
1622                                        psn, diff, header_in_data))
1623                         goto done;
1624                 goto send_ack;
1625         }
1626
1627         /* Check for opcode sequence errors. */
1628         switch (qp->r_state) {
1629         case OP(SEND_FIRST):
1630         case OP(SEND_MIDDLE):
1631                 if (opcode == OP(SEND_MIDDLE) ||
1632                     opcode == OP(SEND_LAST) ||
1633                     opcode == OP(SEND_LAST_WITH_IMMEDIATE))
1634                         break;
1635                 goto nack_inv;
1636
1637         case OP(RDMA_WRITE_FIRST):
1638         case OP(RDMA_WRITE_MIDDLE):
1639                 if (opcode == OP(RDMA_WRITE_MIDDLE) ||
1640                     opcode == OP(RDMA_WRITE_LAST) ||
1641                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1642                         break;
1643                 goto nack_inv;
1644
1645         default:
1646                 if (opcode == OP(SEND_MIDDLE) ||
1647                     opcode == OP(SEND_LAST) ||
1648                     opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
1649                     opcode == OP(RDMA_WRITE_MIDDLE) ||
1650                     opcode == OP(RDMA_WRITE_LAST) ||
1651                     opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
1652                         goto nack_inv;
1653                 /*
1654                  * Note that it is up to the requester to not send a new
1655                  * RDMA read or atomic operation before receiving an ACK
1656                  * for the previous operation.
1657                  */
1658                 break;
1659         }
1660
1661         memset(&wc, 0, sizeof wc);
1662
1663         /* OK, process the packet. */
1664         switch (opcode) {
1665         case OP(SEND_FIRST):
1666                 if (!ipath_get_rwqe(qp, 0))
1667                         goto rnr_nak;
1668                 qp->r_rcv_len = 0;
1669                 /* FALLTHROUGH */
1670         case OP(SEND_MIDDLE):
1671         case OP(RDMA_WRITE_MIDDLE):
1672         send_middle:
1673                 /* Check for invalid length PMTU or posted rwqe len. */
1674                 if (unlikely(tlen != (hdrsize + pmtu + 4)))
1675                         goto nack_inv;
1676                 qp->r_rcv_len += pmtu;
1677                 if (unlikely(qp->r_rcv_len > qp->r_len))
1678                         goto nack_inv;
1679                 ipath_copy_sge(&qp->r_sge, data, pmtu);
1680                 break;
1681
1682         case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
1683                 /* consume RWQE */
1684                 if (!ipath_get_rwqe(qp, 1))
1685                         goto rnr_nak;
1686                 goto send_last_imm;
1687
1688         case OP(SEND_ONLY):
1689         case OP(SEND_ONLY_WITH_IMMEDIATE):
1690                 if (!ipath_get_rwqe(qp, 0))
1691                         goto rnr_nak;
1692                 qp->r_rcv_len = 0;
1693                 if (opcode == OP(SEND_ONLY))
1694                         goto send_last;
1695                 /* FALLTHROUGH */
1696         case OP(SEND_LAST_WITH_IMMEDIATE):
1697         send_last_imm:
1698                 if (header_in_data) {
1699                         wc.imm_data = *(__be32 *) data;
1700                         data += sizeof(__be32);
1701                 } else {
1702                         /* Immediate data comes after BTH */
1703                         wc.imm_data = ohdr->u.imm_data;
1704                 }
1705                 hdrsize += 4;
1706                 wc.wc_flags = IB_WC_WITH_IMM;
1707                 /* FALLTHROUGH */
1708         case OP(SEND_LAST):
1709         case OP(RDMA_WRITE_LAST):
1710         send_last:
1711                 /* Get the number of bytes the message was padded by. */
1712                 pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
1713                 /* Check for invalid length. */
1714                 /* XXX LAST len should be >= 1 */
1715                 if (unlikely(tlen < (hdrsize + pad + 4)))
1716                         goto nack_inv;
1717                 /* Don't count the CRC. */
1718                 tlen -= (hdrsize + pad + 4);
1719                 wc.byte_len = tlen + qp->r_rcv_len;
1720                 if (unlikely(wc.byte_len > qp->r_len))
1721                         goto nack_inv;
1722                 ipath_copy_sge(&qp->r_sge, data, tlen);
1723                 qp->r_msn++;
1724                 if (!test_and_clear_bit(IPATH_R_WRID_VALID, &qp->r_aflags))
1725                         break;
1726                 wc.wr_id = qp->r_wr_id;
1727                 wc.status = IB_WC_SUCCESS;
1728                 if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
1729                     opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
1730                         wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
1731                 else
1732                         wc.opcode = IB_WC_RECV;
1733                 wc.qp = &qp->ibqp;
1734                 wc.src_qp = qp->remote_qpn;
1735                 wc.slid = qp->remote_ah_attr.dlid;
1736                 wc.sl = qp->remote_ah_attr.sl;
1737                 /* Signal completion event if the solicited bit is set. */
1738                 ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
1739                                (ohdr->bth[0] &
1740                                 __constant_cpu_to_be32(1 << 23)) != 0);
1741                 break;
1742
1743         case OP(RDMA_WRITE_FIRST):
1744         case OP(RDMA_WRITE_ONLY):
1745         case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
1746                 if (unlikely(!(qp->qp_access_flags &
1747                                IB_ACCESS_REMOTE_WRITE)))
1748                         goto nack_inv;
1749                 /* consume RWQE */
1750                 /* RETH comes after BTH */
1751                 if (!header_in_data)
1752                         reth = &ohdr->u.rc.reth;
1753                 else {
1754                         reth = (struct ib_reth *)data;
1755                         data += sizeof(*reth);
1756                 }
1757                 hdrsize += sizeof(*reth);
1758                 qp->r_len = be32_to_cpu(reth->length);
1759                 qp->r_rcv_len = 0;
1760                 if (qp->r_len != 0) {
1761                         u32 rkey = be32_to_cpu(reth->rkey);
1762                         u64 vaddr = be64_to_cpu(reth->vaddr);
1763                         int ok;
1764
1765                         /* Check rkey & NAK */
1766                         ok = ipath_rkey_ok(qp, &qp->r_sge,
1767                                            qp->r_len, vaddr, rkey,
1768                                            IB_ACCESS_REMOTE_WRITE);
1769                         if (unlikely(!ok))
1770                                 goto nack_acc;
1771                 } else {
1772                         qp->r_sge.sg_list = NULL;
1773                         qp->r_sge.sge.mr = NULL;
1774                         qp->r_sge.sge.vaddr = NULL;
1775                         qp->r_sge.sge.length = 0;
1776                         qp->r_sge.sge.sge_length = 0;
1777                 }
1778                 if (opcode == OP(RDMA_WRITE_FIRST))
1779                         goto send_middle;
1780                 else if (opcode == OP(RDMA_WRITE_ONLY))
1781                         goto send_last;
1782                 if (!ipath_get_rwqe(qp, 1))
1783                         goto rnr_nak;
1784                 goto send_last_imm;
1785
1786         case OP(RDMA_READ_REQUEST): {
1787                 struct ipath_ack_entry *e;
1788                 u32 len;
1789                 u8 next;
1790
1791                 if (unlikely(!(qp->qp_access_flags &
1792                                IB_ACCESS_REMOTE_READ)))
1793                         goto nack_inv;
1794                 next = qp->r_head_ack_queue + 1;
1795                 if (next > IPATH_MAX_RDMA_ATOMIC)
1796                         next = 0;
1797                 spin_lock_irqsave(&qp->s_lock, flags);
1798                 /* Double check we can process this while holding the s_lock. */
1799                 if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1800                         goto unlock;
1801                 if (unlikely(next == qp->s_tail_ack_queue)) {
1802                         if (!qp->s_ack_queue[next].sent)
1803                                 goto nack_inv_unlck;
1804                         ipath_update_ack_queue(qp, next);
1805                 }
1806                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
1807                 /* RETH comes after BTH */
1808                 if (!header_in_data)
1809                         reth = &ohdr->u.rc.reth;
1810                 else {
1811                         reth = (struct ib_reth *)data;
1812                         data += sizeof(*reth);
1813                 }
1814                 len = be32_to_cpu(reth->length);
1815                 if (len) {
1816                         u32 rkey = be32_to_cpu(reth->rkey);
1817                         u64 vaddr = be64_to_cpu(reth->vaddr);
1818                         int ok;
1819
1820                         /* Check rkey & NAK */
1821                         ok = ipath_rkey_ok(qp, &e->rdma_sge, len, vaddr,
1822                                            rkey, IB_ACCESS_REMOTE_READ);
1823                         if (unlikely(!ok))
1824                                 goto nack_acc_unlck;
1825                         /*
1826                          * Update the next expected PSN.  We add 1 later
1827                          * below, so only add the remainder here.
1828                          */
1829                         if (len > pmtu)
1830                                 qp->r_psn += (len - 1) / pmtu;
1831                 } else {
1832                         e->rdma_sge.sg_list = NULL;
1833                         e->rdma_sge.num_sge = 0;
1834                         e->rdma_sge.sge.mr = NULL;
1835                         e->rdma_sge.sge.vaddr = NULL;
1836                         e->rdma_sge.sge.length = 0;
1837                         e->rdma_sge.sge.sge_length = 0;
1838                 }
1839                 e->opcode = opcode;
1840                 e->sent = 0;
1841                 e->psn = psn;
1842                 /*
1843                  * We need to increment the MSN here instead of when we
1844                  * finish sending the result since a duplicate request would
1845                  * increment it more than once.
1846                  */
1847                 qp->r_msn++;
1848                 qp->r_psn++;
1849                 qp->r_state = opcode;
1850                 qp->r_nak_state = 0;
1851                 qp->r_head_ack_queue = next;
1852
1853                 /* Schedule the send tasklet. */
1854                 ipath_schedule_send(qp);
1855
1856                 goto unlock;
1857         }
1858
1859         case OP(COMPARE_SWAP):
1860         case OP(FETCH_ADD): {
1861                 struct ib_atomic_eth *ateth;
1862                 struct ipath_ack_entry *e;
1863                 u64 vaddr;
1864                 atomic64_t *maddr;
1865                 u64 sdata;
1866                 u32 rkey;
1867                 u8 next;
1868
1869                 if (unlikely(!(qp->qp_access_flags &
1870                                IB_ACCESS_REMOTE_ATOMIC)))
1871                         goto nack_inv;
1872                 next = qp->r_head_ack_queue + 1;
1873                 if (next > IPATH_MAX_RDMA_ATOMIC)
1874                         next = 0;
1875                 spin_lock_irqsave(&qp->s_lock, flags);
1876                 /* Double check we can process this while holding the s_lock. */
1877                 if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK))
1878                         goto unlock;
1879                 if (unlikely(next == qp->s_tail_ack_queue)) {
1880                         if (!qp->s_ack_queue[next].sent)
1881                                 goto nack_inv_unlck;
1882                         ipath_update_ack_queue(qp, next);
1883                 }
1884                 if (!header_in_data)
1885                         ateth = &ohdr->u.atomic_eth;
1886                 else
1887                         ateth = (struct ib_atomic_eth *)data;
1888                 vaddr = ((u64) be32_to_cpu(ateth->vaddr[0]) << 32) |
1889                         be32_to_cpu(ateth->vaddr[1]);
1890                 if (unlikely(vaddr & (sizeof(u64) - 1)))
1891                         goto nack_inv_unlck;
1892                 rkey = be32_to_cpu(ateth->rkey);
1893                 /* Check rkey & NAK */
1894                 if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge,
1895                                             sizeof(u64), vaddr, rkey,
1896                                             IB_ACCESS_REMOTE_ATOMIC)))
1897                         goto nack_acc_unlck;
1898                 /* Perform atomic OP and save result. */
1899                 maddr = (atomic64_t *) qp->r_sge.sge.vaddr;
1900                 sdata = be64_to_cpu(ateth->swap_data);
1901                 e = &qp->s_ack_queue[qp->r_head_ack_queue];
1902                 e->atomic_data = (opcode == OP(FETCH_ADD)) ?
1903                         (u64) atomic64_add_return(sdata, maddr) - sdata :
1904                         (u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr,
1905                                       be64_to_cpu(ateth->compare_data),
1906                                       sdata);
1907                 e->opcode = opcode;
1908                 e->sent = 0;
1909                 e->psn = psn & IPATH_PSN_MASK;
1910                 qp->r_msn++;
1911                 qp->r_psn++;
1912                 qp->r_state = opcode;
1913                 qp->r_nak_state = 0;
1914                 qp->r_head_ack_queue = next;
1915
1916                 /* Schedule the send tasklet. */
1917                 ipath_schedule_send(qp);
1918
1919                 goto unlock;
1920         }
1921
1922         default:
1923                 /* NAK unknown opcodes. */
1924                 goto nack_inv;
1925         }
1926         qp->r_psn++;
1927         qp->r_state = opcode;
1928         qp->r_ack_psn = psn;
1929         qp->r_nak_state = 0;
1930         /* Send an ACK if requested or required. */
1931         if (psn & (1 << 31))
1932                 goto send_ack;
1933         goto done;
1934
1935 rnr_nak:
1936         qp->r_nak_state = IB_RNR_NAK | qp->r_min_rnr_timer;
1937         qp->r_ack_psn = qp->r_psn;
1938         goto send_ack;
1939
1940 nack_inv_unlck:
1941         spin_unlock_irqrestore(&qp->s_lock, flags);
1942 nack_inv:
1943         ipath_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
1944         qp->r_nak_state = IB_NAK_INVALID_REQUEST;
1945         qp->r_ack_psn = qp->r_psn;
1946         goto send_ack;
1947
1948 nack_acc_unlck:
1949         spin_unlock_irqrestore(&qp->s_lock, flags);
1950 nack_acc:
1951         ipath_rc_error(qp, IB_WC_LOC_PROT_ERR);
1952         qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
1953         qp->r_ack_psn = qp->r_psn;
1954 send_ack:
1955         send_rc_ack(qp);
1956         goto done;
1957
1958 unlock:
1959         spin_unlock_irqrestore(&qp->s_lock, flags);
1960 done:
1961         return;
1962 }