Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland...
[linux-2.6] / drivers / infiniband / hw / ipath / ipath_ruc.c
1 /*
2  * Copyright (c) 2006, 2007 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/spinlock.h>
35
36 #include "ipath_verbs.h"
37 #include "ipath_kernel.h"
38
39 /*
40  * Convert the AETH RNR timeout code into the number of milliseconds.
41  */
42 const u32 ib_ipath_rnr_table[32] = {
43         656,                    /* 0 */
44         1,                      /* 1 */
45         1,                      /* 2 */
46         1,                      /* 3 */
47         1,                      /* 4 */
48         1,                      /* 5 */
49         1,                      /* 6 */
50         1,                      /* 7 */
51         1,                      /* 8 */
52         1,                      /* 9 */
53         1,                      /* A */
54         1,                      /* B */
55         1,                      /* C */
56         1,                      /* D */
57         2,                      /* E */
58         2,                      /* F */
59         3,                      /* 10 */
60         4,                      /* 11 */
61         6,                      /* 12 */
62         8,                      /* 13 */
63         11,                     /* 14 */
64         16,                     /* 15 */
65         21,                     /* 16 */
66         31,                     /* 17 */
67         41,                     /* 18 */
68         62,                     /* 19 */
69         82,                     /* 1A */
70         123,                    /* 1B */
71         164,                    /* 1C */
72         246,                    /* 1D */
73         328,                    /* 1E */
74         492                     /* 1F */
75 };
76
77 /**
78  * ipath_insert_rnr_queue - put QP on the RNR timeout list for the device
79  * @qp: the QP
80  *
81  * XXX Use a simple list for now.  We might need a priority
82  * queue if we have lots of QPs waiting for RNR timeouts
83  * but that should be rare.
84  */
85 void ipath_insert_rnr_queue(struct ipath_qp *qp)
86 {
87         struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
88         unsigned long flags;
89
90         spin_lock_irqsave(&dev->pending_lock, flags);
91         if (list_empty(&dev->rnrwait))
92                 list_add(&qp->timerwait, &dev->rnrwait);
93         else {
94                 struct list_head *l = &dev->rnrwait;
95                 struct ipath_qp *nqp = list_entry(l->next, struct ipath_qp,
96                                                   timerwait);
97
98                 while (qp->s_rnr_timeout >= nqp->s_rnr_timeout) {
99                         qp->s_rnr_timeout -= nqp->s_rnr_timeout;
100                         l = l->next;
101                         if (l->next == &dev->rnrwait)
102                                 break;
103                         nqp = list_entry(l->next, struct ipath_qp,
104                                          timerwait);
105                 }
106                 list_add(&qp->timerwait, l);
107         }
108         spin_unlock_irqrestore(&dev->pending_lock, flags);
109 }
110
111 /**
112  * ipath_init_sge - Validate a RWQE and fill in the SGE state
113  * @qp: the QP
114  *
115  * Return 1 if OK.
116  */
117 int ipath_init_sge(struct ipath_qp *qp, struct ipath_rwqe *wqe,
118                    u32 *lengthp, struct ipath_sge_state *ss)
119 {
120         int i, j, ret;
121         struct ib_wc wc;
122
123         *lengthp = 0;
124         for (i = j = 0; i < wqe->num_sge; i++) {
125                 if (wqe->sg_list[i].length == 0)
126                         continue;
127                 /* Check LKEY */
128                 if (!ipath_lkey_ok(qp, j ? &ss->sg_list[j - 1] : &ss->sge,
129                                    &wqe->sg_list[i], IB_ACCESS_LOCAL_WRITE))
130                         goto bad_lkey;
131                 *lengthp += wqe->sg_list[i].length;
132                 j++;
133         }
134         ss->num_sge = j;
135         ret = 1;
136         goto bail;
137
138 bad_lkey:
139         wc.wr_id = wqe->wr_id;
140         wc.status = IB_WC_LOC_PROT_ERR;
141         wc.opcode = IB_WC_RECV;
142         wc.vendor_err = 0;
143         wc.byte_len = 0;
144         wc.imm_data = 0;
145         wc.qp = &qp->ibqp;
146         wc.src_qp = 0;
147         wc.wc_flags = 0;
148         wc.pkey_index = 0;
149         wc.slid = 0;
150         wc.sl = 0;
151         wc.dlid_path_bits = 0;
152         wc.port_num = 0;
153         /* Signal solicited completion event. */
154         ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
155         ret = 0;
156 bail:
157         return ret;
158 }
159
160 /**
161  * ipath_get_rwqe - copy the next RWQE into the QP's RWQE
162  * @qp: the QP
163  * @wr_id_only: update wr_id only, not SGEs
164  *
165  * Return 0 if no RWQE is available, otherwise return 1.
166  *
167  * Can be called from interrupt level.
168  */
169 int ipath_get_rwqe(struct ipath_qp *qp, int wr_id_only)
170 {
171         unsigned long flags;
172         struct ipath_rq *rq;
173         struct ipath_rwq *wq;
174         struct ipath_srq *srq;
175         struct ipath_rwqe *wqe;
176         void (*handler)(struct ib_event *, void *);
177         u32 tail;
178         int ret;
179
180         qp->r_sge.sg_list = qp->r_sg_list;
181
182         if (qp->ibqp.srq) {
183                 srq = to_isrq(qp->ibqp.srq);
184                 handler = srq->ibsrq.event_handler;
185                 rq = &srq->rq;
186         } else {
187                 srq = NULL;
188                 handler = NULL;
189                 rq = &qp->r_rq;
190         }
191
192         spin_lock_irqsave(&rq->lock, flags);
193         wq = rq->wq;
194         tail = wq->tail;
195         /* Validate tail before using it since it is user writable. */
196         if (tail >= rq->size)
197                 tail = 0;
198         do {
199                 if (unlikely(tail == wq->head)) {
200                         spin_unlock_irqrestore(&rq->lock, flags);
201                         ret = 0;
202                         goto bail;
203                 }
204                 /* Make sure entry is read after head index is read. */
205                 smp_rmb();
206                 wqe = get_rwqe_ptr(rq, tail);
207                 if (++tail >= rq->size)
208                         tail = 0;
209         } while (!wr_id_only && !ipath_init_sge(qp, wqe, &qp->r_len,
210                                                 &qp->r_sge));
211         qp->r_wr_id = wqe->wr_id;
212         wq->tail = tail;
213
214         ret = 1;
215         qp->r_wrid_valid = 1;
216         if (handler) {
217                 u32 n;
218
219                 /*
220                  * validate head pointer value and compute
221                  * the number of remaining WQEs.
222                  */
223                 n = wq->head;
224                 if (n >= rq->size)
225                         n = 0;
226                 if (n < tail)
227                         n += rq->size - tail;
228                 else
229                         n -= tail;
230                 if (n < srq->limit) {
231                         struct ib_event ev;
232
233                         srq->limit = 0;
234                         spin_unlock_irqrestore(&rq->lock, flags);
235                         ev.device = qp->ibqp.device;
236                         ev.element.srq = qp->ibqp.srq;
237                         ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
238                         handler(&ev, srq->ibsrq.srq_context);
239                         goto bail;
240                 }
241         }
242         spin_unlock_irqrestore(&rq->lock, flags);
243
244 bail:
245         return ret;
246 }
247
248 /**
249  * ipath_ruc_loopback - handle UC and RC lookback requests
250  * @sqp: the sending QP
251  *
252  * This is called from ipath_do_send() to
253  * forward a WQE addressed to the same HCA.
254  * Note that although we are single threaded due to the tasklet, we still
255  * have to protect against post_send().  We don't have to worry about
256  * receive interrupts since this is a connected protocol and all packets
257  * will pass through here.
258  */
259 static void ipath_ruc_loopback(struct ipath_qp *sqp)
260 {
261         struct ipath_ibdev *dev = to_idev(sqp->ibqp.device);
262         struct ipath_qp *qp;
263         struct ipath_swqe *wqe;
264         struct ipath_sge *sge;
265         unsigned long flags;
266         struct ib_wc wc;
267         u64 sdata;
268         atomic64_t *maddr;
269
270         qp = ipath_lookup_qpn(&dev->qp_table, sqp->remote_qpn);
271         if (!qp) {
272                 dev->n_pkt_drops++;
273                 return;
274         }
275
276 again:
277         spin_lock_irqsave(&sqp->s_lock, flags);
278
279         if (!(ib_ipath_state_ops[sqp->state] & IPATH_PROCESS_SEND_OK) ||
280             sqp->s_rnr_timeout) {
281                 spin_unlock_irqrestore(&sqp->s_lock, flags);
282                 goto done;
283         }
284
285         /* Get the next send request. */
286         if (sqp->s_last == sqp->s_head) {
287                 /* Send work queue is empty. */
288                 spin_unlock_irqrestore(&sqp->s_lock, flags);
289                 goto done;
290         }
291
292         /*
293          * We can rely on the entry not changing without the s_lock
294          * being held until we update s_last.
295          */
296         wqe = get_swqe_ptr(sqp, sqp->s_last);
297         spin_unlock_irqrestore(&sqp->s_lock, flags);
298
299         wc.wc_flags = 0;
300         wc.imm_data = 0;
301
302         sqp->s_sge.sge = wqe->sg_list[0];
303         sqp->s_sge.sg_list = wqe->sg_list + 1;
304         sqp->s_sge.num_sge = wqe->wr.num_sge;
305         sqp->s_len = wqe->length;
306         switch (wqe->wr.opcode) {
307         case IB_WR_SEND_WITH_IMM:
308                 wc.wc_flags = IB_WC_WITH_IMM;
309                 wc.imm_data = wqe->wr.imm_data;
310                 /* FALLTHROUGH */
311         case IB_WR_SEND:
312                 if (!ipath_get_rwqe(qp, 0)) {
313                 rnr_nak:
314                         /* Handle RNR NAK */
315                         if (qp->ibqp.qp_type == IB_QPT_UC)
316                                 goto send_comp;
317                         if (sqp->s_rnr_retry == 0) {
318                                 wc.status = IB_WC_RNR_RETRY_EXC_ERR;
319                                 goto err;
320                         }
321                         if (sqp->s_rnr_retry_cnt < 7)
322                                 sqp->s_rnr_retry--;
323                         dev->n_rnr_naks++;
324                         sqp->s_rnr_timeout =
325                                 ib_ipath_rnr_table[qp->r_min_rnr_timer];
326                         ipath_insert_rnr_queue(sqp);
327                         goto done;
328                 }
329                 break;
330
331         case IB_WR_RDMA_WRITE_WITH_IMM:
332                 if (unlikely(!(qp->qp_access_flags &
333                                IB_ACCESS_REMOTE_WRITE))) {
334                         wc.status = IB_WC_REM_INV_REQ_ERR;
335                         goto err;
336                 }
337                 wc.wc_flags = IB_WC_WITH_IMM;
338                 wc.imm_data = wqe->wr.imm_data;
339                 if (!ipath_get_rwqe(qp, 1))
340                         goto rnr_nak;
341                 /* FALLTHROUGH */
342         case IB_WR_RDMA_WRITE:
343                 if (unlikely(!(qp->qp_access_flags &
344                                IB_ACCESS_REMOTE_WRITE))) {
345                         wc.status = IB_WC_REM_INV_REQ_ERR;
346                         goto err;
347                 }
348                 if (wqe->length == 0)
349                         break;
350                 if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge, wqe->length,
351                                             wqe->wr.wr.rdma.remote_addr,
352                                             wqe->wr.wr.rdma.rkey,
353                                             IB_ACCESS_REMOTE_WRITE))) {
354                 acc_err:
355                         wc.status = IB_WC_REM_ACCESS_ERR;
356                 err:
357                         wc.wr_id = wqe->wr.wr_id;
358                         wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
359                         wc.vendor_err = 0;
360                         wc.byte_len = 0;
361                         wc.qp = &sqp->ibqp;
362                         wc.src_qp = sqp->remote_qpn;
363                         wc.pkey_index = 0;
364                         wc.slid = sqp->remote_ah_attr.dlid;
365                         wc.sl = sqp->remote_ah_attr.sl;
366                         wc.dlid_path_bits = 0;
367                         wc.port_num = 0;
368                         spin_lock_irqsave(&sqp->s_lock, flags);
369                         ipath_sqerror_qp(sqp, &wc);
370                         spin_unlock_irqrestore(&sqp->s_lock, flags);
371                         goto done;
372                 }
373                 break;
374
375         case IB_WR_RDMA_READ:
376                 if (unlikely(!(qp->qp_access_flags &
377                                IB_ACCESS_REMOTE_READ))) {
378                         wc.status = IB_WC_REM_INV_REQ_ERR;
379                         goto err;
380                 }
381                 if (unlikely(!ipath_rkey_ok(qp, &sqp->s_sge, wqe->length,
382                                             wqe->wr.wr.rdma.remote_addr,
383                                             wqe->wr.wr.rdma.rkey,
384                                             IB_ACCESS_REMOTE_READ)))
385                         goto acc_err;
386                 qp->r_sge.sge = wqe->sg_list[0];
387                 qp->r_sge.sg_list = wqe->sg_list + 1;
388                 qp->r_sge.num_sge = wqe->wr.num_sge;
389                 break;
390
391         case IB_WR_ATOMIC_CMP_AND_SWP:
392         case IB_WR_ATOMIC_FETCH_AND_ADD:
393                 if (unlikely(!(qp->qp_access_flags &
394                                IB_ACCESS_REMOTE_ATOMIC))) {
395                         wc.status = IB_WC_REM_INV_REQ_ERR;
396                         goto err;
397                 }
398                 if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge, sizeof(u64),
399                                             wqe->wr.wr.atomic.remote_addr,
400                                             wqe->wr.wr.atomic.rkey,
401                                             IB_ACCESS_REMOTE_ATOMIC)))
402                         goto acc_err;
403                 /* Perform atomic OP and save result. */
404                 maddr = (atomic64_t *) qp->r_sge.sge.vaddr;
405                 sdata = wqe->wr.wr.atomic.compare_add;
406                 *(u64 *) sqp->s_sge.sge.vaddr =
407                         (wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) ?
408                         (u64) atomic64_add_return(sdata, maddr) - sdata :
409                         (u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr,
410                                       sdata, wqe->wr.wr.atomic.swap);
411                 goto send_comp;
412
413         default:
414                 goto done;
415         }
416
417         sge = &sqp->s_sge.sge;
418         while (sqp->s_len) {
419                 u32 len = sqp->s_len;
420
421                 if (len > sge->length)
422                         len = sge->length;
423                 if (len > sge->sge_length)
424                         len = sge->sge_length;
425                 BUG_ON(len == 0);
426                 ipath_copy_sge(&qp->r_sge, sge->vaddr, len);
427                 sge->vaddr += len;
428                 sge->length -= len;
429                 sge->sge_length -= len;
430                 if (sge->sge_length == 0) {
431                         if (--sqp->s_sge.num_sge)
432                                 *sge = *sqp->s_sge.sg_list++;
433                 } else if (sge->length == 0 && sge->mr != NULL) {
434                         if (++sge->n >= IPATH_SEGSZ) {
435                                 if (++sge->m >= sge->mr->mapsz)
436                                         break;
437                                 sge->n = 0;
438                         }
439                         sge->vaddr =
440                                 sge->mr->map[sge->m]->segs[sge->n].vaddr;
441                         sge->length =
442                                 sge->mr->map[sge->m]->segs[sge->n].length;
443                 }
444                 sqp->s_len -= len;
445         }
446
447         if (wqe->wr.opcode == IB_WR_RDMA_WRITE ||
448             wqe->wr.opcode == IB_WR_RDMA_READ)
449                 goto send_comp;
450
451         if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM)
452                 wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
453         else
454                 wc.opcode = IB_WC_RECV;
455         wc.wr_id = qp->r_wr_id;
456         wc.status = IB_WC_SUCCESS;
457         wc.vendor_err = 0;
458         wc.byte_len = wqe->length;
459         wc.qp = &qp->ibqp;
460         wc.src_qp = qp->remote_qpn;
461         wc.pkey_index = 0;
462         wc.slid = qp->remote_ah_attr.dlid;
463         wc.sl = qp->remote_ah_attr.sl;
464         wc.dlid_path_bits = 0;
465         wc.port_num = 1;
466         /* Signal completion event if the solicited bit is set. */
467         ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
468                        wqe->wr.send_flags & IB_SEND_SOLICITED);
469
470 send_comp:
471         sqp->s_rnr_retry = sqp->s_rnr_retry_cnt;
472         ipath_send_complete(sqp, wqe, IB_WC_SUCCESS);
473         goto again;
474
475 done:
476         if (atomic_dec_and_test(&qp->refcount))
477                 wake_up(&qp->wait);
478 }
479
480 static void want_buffer(struct ipath_devdata *dd)
481 {
482         set_bit(IPATH_S_PIOINTBUFAVAIL, &dd->ipath_sendctrl);
483         ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
484                          dd->ipath_sendctrl);
485 }
486
487 /**
488  * ipath_no_bufs_available - tell the layer driver we need buffers
489  * @qp: the QP that caused the problem
490  * @dev: the device we ran out of buffers on
491  *
492  * Called when we run out of PIO buffers.
493  */
494 static void ipath_no_bufs_available(struct ipath_qp *qp,
495                                     struct ipath_ibdev *dev)
496 {
497         unsigned long flags;
498
499         /*
500          * Note that as soon as want_buffer() is called and
501          * possibly before it returns, ipath_ib_piobufavail()
502          * could be called.  If we are still in the tasklet function,
503          * tasklet_hi_schedule() will not call us until the next time
504          * tasklet_hi_schedule() is called.
505          * We leave the busy flag set so that another post send doesn't
506          * try to put the same QP on the piowait list again.
507          */
508         spin_lock_irqsave(&dev->pending_lock, flags);
509         list_add_tail(&qp->piowait, &dev->piowait);
510         spin_unlock_irqrestore(&dev->pending_lock, flags);
511         want_buffer(dev->dd);
512         dev->n_piowait++;
513 }
514
515 /**
516  * ipath_make_grh - construct a GRH header
517  * @dev: a pointer to the ipath device
518  * @hdr: a pointer to the GRH header being constructed
519  * @grh: the global route address to send to
520  * @hwords: the number of 32 bit words of header being sent
521  * @nwords: the number of 32 bit words of data being sent
522  *
523  * Return the size of the header in 32 bit words.
524  */
525 u32 ipath_make_grh(struct ipath_ibdev *dev, struct ib_grh *hdr,
526                    struct ib_global_route *grh, u32 hwords, u32 nwords)
527 {
528         hdr->version_tclass_flow =
529                 cpu_to_be32((6 << 28) |
530                             (grh->traffic_class << 20) |
531                             grh->flow_label);
532         hdr->paylen = cpu_to_be16((hwords - 2 + nwords + SIZE_OF_CRC) << 2);
533         /* next_hdr is defined by C8-7 in ch. 8.4.1 */
534         hdr->next_hdr = 0x1B;
535         hdr->hop_limit = grh->hop_limit;
536         /* The SGID is 32-bit aligned. */
537         hdr->sgid.global.subnet_prefix = dev->gid_prefix;
538         hdr->sgid.global.interface_id = dev->dd->ipath_guid;
539         hdr->dgid = grh->dgid;
540
541         /* GRH header size in 32-bit words. */
542         return sizeof(struct ib_grh) / sizeof(u32);
543 }
544
545 void ipath_make_ruc_header(struct ipath_ibdev *dev, struct ipath_qp *qp,
546                            struct ipath_other_headers *ohdr,
547                            u32 bth0, u32 bth2)
548 {
549         u16 lrh0;
550         u32 nwords;
551         u32 extra_bytes;
552
553         /* Construct the header. */
554         extra_bytes = -qp->s_cur_size & 3;
555         nwords = (qp->s_cur_size + extra_bytes) >> 2;
556         lrh0 = IPATH_LRH_BTH;
557         if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
558                 qp->s_hdrwords += ipath_make_grh(dev, &qp->s_hdr.u.l.grh,
559                                                  &qp->remote_ah_attr.grh,
560                                                  qp->s_hdrwords, nwords);
561                 lrh0 = IPATH_LRH_GRH;
562         }
563         lrh0 |= qp->remote_ah_attr.sl << 4;
564         qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
565         qp->s_hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
566         qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
567         qp->s_hdr.lrh[3] = cpu_to_be16(dev->dd->ipath_lid);
568         bth0 |= ipath_get_pkey(dev->dd, qp->s_pkey_index);
569         bth0 |= extra_bytes << 20;
570         ohdr->bth[0] = cpu_to_be32(bth0 | (1 << 22));
571         ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
572         ohdr->bth[2] = cpu_to_be32(bth2);
573 }
574
575 /**
576  * ipath_do_send - perform a send on a QP
577  * @data: contains a pointer to the QP
578  *
579  * Process entries in the send work queue until credit or queue is
580  * exhausted.  Only allow one CPU to send a packet per QP (tasklet).
581  * Otherwise, two threads could send packets out of order.
582  */
583 void ipath_do_send(unsigned long data)
584 {
585         struct ipath_qp *qp = (struct ipath_qp *)data;
586         struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
587         int (*make_req)(struct ipath_qp *qp);
588
589         if (test_and_set_bit(IPATH_S_BUSY, &qp->s_busy))
590                 goto bail;
591
592         if ((qp->ibqp.qp_type == IB_QPT_RC ||
593              qp->ibqp.qp_type == IB_QPT_UC) &&
594             qp->remote_ah_attr.dlid == dev->dd->ipath_lid) {
595                 ipath_ruc_loopback(qp);
596                 goto clear;
597         }
598
599         if (qp->ibqp.qp_type == IB_QPT_RC)
600                make_req = ipath_make_rc_req;
601         else if (qp->ibqp.qp_type == IB_QPT_UC)
602                make_req = ipath_make_uc_req;
603         else
604                make_req = ipath_make_ud_req;
605
606 again:
607         /* Check for a constructed packet to be sent. */
608         if (qp->s_hdrwords != 0) {
609                 /*
610                  * If no PIO bufs are available, return.  An interrupt will
611                  * call ipath_ib_piobufavail() when one is available.
612                  */
613                 if (ipath_verbs_send(qp, &qp->s_hdr, qp->s_hdrwords,
614                                      qp->s_cur_sge, qp->s_cur_size)) {
615                         ipath_no_bufs_available(qp, dev);
616                         goto bail;
617                 }
618                 dev->n_unicast_xmit++;
619                 /* Record that we sent the packet and s_hdr is empty. */
620                 qp->s_hdrwords = 0;
621         }
622
623         if (make_req(qp))
624                 goto again;
625 clear:
626         clear_bit(IPATH_S_BUSY, &qp->s_busy);
627 bail:;
628 }
629
630 void ipath_send_complete(struct ipath_qp *qp, struct ipath_swqe *wqe,
631                          enum ib_wc_status status)
632 {
633         u32 last = qp->s_last;
634
635         if (++last == qp->s_size)
636                 last = 0;
637         qp->s_last = last;
638
639         /* See ch. 11.2.4.1 and 10.7.3.1 */
640         if (!(qp->s_flags & IPATH_S_SIGNAL_REQ_WR) ||
641             (wqe->wr.send_flags & IB_SEND_SIGNALED) ||
642             status != IB_WC_SUCCESS) {
643                 struct ib_wc wc;
644
645                 wc.wr_id = wqe->wr.wr_id;
646                 wc.status = status;
647                 wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
648                 wc.vendor_err = 0;
649                 wc.byte_len = wqe->length;
650                 wc.imm_data = 0;
651                 wc.qp = &qp->ibqp;
652                 wc.src_qp = 0;
653                 wc.wc_flags = 0;
654                 wc.pkey_index = 0;
655                 wc.slid = 0;
656                 wc.sl = 0;
657                 wc.dlid_path_bits = 0;
658                 wc.port_num = 0;
659                 ipath_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 0);
660         }
661 }