1 /*
2 * Copyright (c) 2012 Intel Corporation. All rights reserved.
3 * Copyright (c) 2006 - 2012 QLogic Corporation. * All rights reserved.
4 * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
5 *
6 * This software is available to you under a choice of one of two
7 * licenses. You may choose to be licensed under the terms of the GNU
8 * General Public License (GPL) Version 2, available from the file
9 * COPYING in the main directory of this source tree, or the
10 * OpenIB.org BSD license below:
11 *
12 * Redistribution and use in source and binary forms, with or
13 * without modification, are permitted provided that the following
14 * conditions are met:
15 *
16 * - Redistributions of source code must retain the above
17 * copyright notice, this list of conditions and the following
18 * disclaimer.
19 *
20 * - Redistributions in binary form must reproduce the above
21 * copyright notice, this list of conditions and the following
22 * disclaimer in the documentation and/or other materials
23 * provided with the distribution.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32 * SOFTWARE.
33 */
34
35 #include <linux/err.h>
36 #include <linux/vmalloc.h>
37 #include <linux/jhash.h>
38
39 #include "qib.h"
40
41 #define BITS_PER_PAGE (PAGE_SIZE*BITS_PER_BYTE)
42 #define BITS_PER_PAGE_MASK (BITS_PER_PAGE-1)
43
mk_qpn(struct qib_qpn_table * qpt,struct qpn_map * map,unsigned off)44 static inline unsigned mk_qpn(struct qib_qpn_table *qpt,
45 struct qpn_map *map, unsigned off)
46 {
47 return (map - qpt->map) * BITS_PER_PAGE + off;
48 }
49
find_next_offset(struct qib_qpn_table * qpt,struct qpn_map * map,unsigned off,unsigned n)50 static inline unsigned find_next_offset(struct qib_qpn_table *qpt,
51 struct qpn_map *map, unsigned off,
52 unsigned n)
53 {
54 if (qpt->mask) {
55 off++;
56 if (((off & qpt->mask) >> 1) >= n)
57 off = (off | qpt->mask) + 2;
58 } else
59 off = find_next_zero_bit(map->page, BITS_PER_PAGE, off);
60 return off;
61 }
62
63 /*
64 * Convert the AETH credit code into the number of credits.
65 */
66 static u32 credit_table[31] = {
67 0, /* 0 */
68 1, /* 1 */
69 2, /* 2 */
70 3, /* 3 */
71 4, /* 4 */
72 6, /* 5 */
73 8, /* 6 */
74 12, /* 7 */
75 16, /* 8 */
76 24, /* 9 */
77 32, /* A */
78 48, /* B */
79 64, /* C */
80 96, /* D */
81 128, /* E */
82 192, /* F */
83 256, /* 10 */
84 384, /* 11 */
85 512, /* 12 */
86 768, /* 13 */
87 1024, /* 14 */
88 1536, /* 15 */
89 2048, /* 16 */
90 3072, /* 17 */
91 4096, /* 18 */
92 6144, /* 19 */
93 8192, /* 1A */
94 12288, /* 1B */
95 16384, /* 1C */
96 24576, /* 1D */
97 32768 /* 1E */
98 };
99
get_map_page(struct qib_qpn_table * qpt,struct qpn_map * map)100 static void get_map_page(struct qib_qpn_table *qpt, struct qpn_map *map)
101 {
102 unsigned long page = get_zeroed_page(GFP_KERNEL);
103
104 /*
105 * Free the page if someone raced with us installing it.
106 */
107
108 spin_lock(&qpt->lock);
109 if (map->page)
110 free_page(page);
111 else
112 map->page = (void *)page;
113 spin_unlock(&qpt->lock);
114 }
115
116 /*
117 * Allocate the next available QPN or
118 * zero/one for QP type IB_QPT_SMI/IB_QPT_GSI.
119 */
alloc_qpn(struct qib_devdata * dd,struct qib_qpn_table * qpt,enum ib_qp_type type,u8 port)120 static int alloc_qpn(struct qib_devdata *dd, struct qib_qpn_table *qpt,
121 enum ib_qp_type type, u8 port)
122 {
123 u32 i, offset, max_scan, qpn;
124 struct qpn_map *map;
125 u32 ret;
126
127 if (type == IB_QPT_SMI || type == IB_QPT_GSI) {
128 unsigned n;
129
130 ret = type == IB_QPT_GSI;
131 n = 1 << (ret + 2 * (port - 1));
132 spin_lock(&qpt->lock);
133 if (qpt->flags & n)
134 ret = -EINVAL;
135 else
136 qpt->flags |= n;
137 spin_unlock(&qpt->lock);
138 goto bail;
139 }
140
141 qpn = qpt->last + 2;
142 if (qpn >= QPN_MAX)
143 qpn = 2;
144 if (qpt->mask && ((qpn & qpt->mask) >> 1) >= dd->n_krcv_queues)
145 qpn = (qpn | qpt->mask) + 2;
146 offset = qpn & BITS_PER_PAGE_MASK;
147 map = &qpt->map[qpn / BITS_PER_PAGE];
148 max_scan = qpt->nmaps - !offset;
149 for (i = 0;;) {
150 if (unlikely(!map->page)) {
151 get_map_page(qpt, map);
152 if (unlikely(!map->page))
153 break;
154 }
155 do {
156 if (!test_and_set_bit(offset, map->page)) {
157 qpt->last = qpn;
158 ret = qpn;
159 goto bail;
160 }
161 offset = find_next_offset(qpt, map, offset,
162 dd->n_krcv_queues);
163 qpn = mk_qpn(qpt, map, offset);
164 /*
165 * This test differs from alloc_pidmap().
166 * If find_next_offset() does find a zero
167 * bit, we don't need to check for QPN
168 * wrapping around past our starting QPN.
169 * We just need to be sure we don't loop
170 * forever.
171 */
172 } while (offset < BITS_PER_PAGE && qpn < QPN_MAX);
173 /*
174 * In order to keep the number of pages allocated to a
175 * minimum, we scan the all existing pages before increasing
176 * the size of the bitmap table.
177 */
178 if (++i > max_scan) {
179 if (qpt->nmaps == QPNMAP_ENTRIES)
180 break;
181 map = &qpt->map[qpt->nmaps++];
182 offset = 0;
183 } else if (map < &qpt->map[qpt->nmaps]) {
184 ++map;
185 offset = 0;
186 } else {
187 map = &qpt->map[0];
188 offset = 2;
189 }
190 qpn = mk_qpn(qpt, map, offset);
191 }
192
193 ret = -ENOMEM;
194
195 bail:
196 return ret;
197 }
198
free_qpn(struct qib_qpn_table * qpt,u32 qpn)199 static void free_qpn(struct qib_qpn_table *qpt, u32 qpn)
200 {
201 struct qpn_map *map;
202
203 map = qpt->map + qpn / BITS_PER_PAGE;
204 if (map->page)
205 clear_bit(qpn & BITS_PER_PAGE_MASK, map->page);
206 }
207
qpn_hash(struct qib_ibdev * dev,u32 qpn)208 static inline unsigned qpn_hash(struct qib_ibdev *dev, u32 qpn)
209 {
210 return jhash_1word(qpn, dev->qp_rnd) &
211 (dev->qp_table_size - 1);
212 }
213
214
215 /*
216 * Put the QP into the hash table.
217 * The hash table holds a reference to the QP.
218 */
insert_qp(struct qib_ibdev * dev,struct qib_qp * qp)219 static void insert_qp(struct qib_ibdev *dev, struct qib_qp *qp)
220 {
221 struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
222 unsigned long flags;
223 unsigned n = qpn_hash(dev, qp->ibqp.qp_num);
224
225 spin_lock_irqsave(&dev->qpt_lock, flags);
226 atomic_inc(&qp->refcount);
227
228 if (qp->ibqp.qp_num == 0)
229 rcu_assign_pointer(ibp->qp0, qp);
230 else if (qp->ibqp.qp_num == 1)
231 rcu_assign_pointer(ibp->qp1, qp);
232 else {
233 qp->next = dev->qp_table[n];
234 rcu_assign_pointer(dev->qp_table[n], qp);
235 }
236
237 spin_unlock_irqrestore(&dev->qpt_lock, flags);
238 synchronize_rcu();
239 }
240
241 /*
242 * Remove the QP from the table so it can't be found asynchronously by
243 * the receive interrupt routine.
244 */
remove_qp(struct qib_ibdev * dev,struct qib_qp * qp)245 static void remove_qp(struct qib_ibdev *dev, struct qib_qp *qp)
246 {
247 struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
248 unsigned n = qpn_hash(dev, qp->ibqp.qp_num);
249 unsigned long flags;
250
251 spin_lock_irqsave(&dev->qpt_lock, flags);
252
253 if (rcu_dereference_protected(ibp->qp0,
254 lockdep_is_held(&dev->qpt_lock)) == qp) {
255 atomic_dec(&qp->refcount);
256 rcu_assign_pointer(ibp->qp0, NULL);
257 } else if (rcu_dereference_protected(ibp->qp1,
258 lockdep_is_held(&dev->qpt_lock)) == qp) {
259 atomic_dec(&qp->refcount);
260 rcu_assign_pointer(ibp->qp1, NULL);
261 } else {
262 struct qib_qp *q;
263 struct qib_qp __rcu **qpp;
264
265 qpp = &dev->qp_table[n];
266 for (; (q = rcu_dereference_protected(*qpp,
267 lockdep_is_held(&dev->qpt_lock))) != NULL;
268 qpp = &q->next)
269 if (q == qp) {
270 atomic_dec(&qp->refcount);
271 rcu_assign_pointer(*qpp,
272 rcu_dereference_protected(qp->next,
273 lockdep_is_held(&dev->qpt_lock)));
274 break;
275 }
276 }
277
278 spin_unlock_irqrestore(&dev->qpt_lock, flags);
279 synchronize_rcu();
280 }
281
282 /**
283 * qib_free_all_qps - check for QPs still in use
284 * @qpt: the QP table to empty
285 *
286 * There should not be any QPs still in use.
287 * Free memory for table.
288 */
qib_free_all_qps(struct qib_devdata * dd)289 unsigned qib_free_all_qps(struct qib_devdata *dd)
290 {
291 struct qib_ibdev *dev = &dd->verbs_dev;
292 unsigned long flags;
293 struct qib_qp *qp;
294 unsigned n, qp_inuse = 0;
295
296 for (n = 0; n < dd->num_pports; n++) {
297 struct qib_ibport *ibp = &dd->pport[n].ibport_data;
298
299 if (!qib_mcast_tree_empty(ibp))
300 qp_inuse++;
301 rcu_read_lock();
302 if (rcu_dereference(ibp->qp0))
303 qp_inuse++;
304 if (rcu_dereference(ibp->qp1))
305 qp_inuse++;
306 rcu_read_unlock();
307 }
308
309 spin_lock_irqsave(&dev->qpt_lock, flags);
310 for (n = 0; n < dev->qp_table_size; n++) {
311 qp = rcu_dereference_protected(dev->qp_table[n],
312 lockdep_is_held(&dev->qpt_lock));
313 rcu_assign_pointer(dev->qp_table[n], NULL);
314
315 for (; qp; qp = rcu_dereference_protected(qp->next,
316 lockdep_is_held(&dev->qpt_lock)))
317 qp_inuse++;
318 }
319 spin_unlock_irqrestore(&dev->qpt_lock, flags);
320 synchronize_rcu();
321
322 return qp_inuse;
323 }
324
325 /**
326 * qib_lookup_qpn - return the QP with the given QPN
327 * @qpt: the QP table
328 * @qpn: the QP number to look up
329 *
330 * The caller is responsible for decrementing the QP reference count
331 * when done.
332 */
qib_lookup_qpn(struct qib_ibport * ibp,u32 qpn)333 struct qib_qp *qib_lookup_qpn(struct qib_ibport *ibp, u32 qpn)
334 {
335 struct qib_qp *qp = NULL;
336
337 if (unlikely(qpn <= 1)) {
338 rcu_read_lock();
339 if (qpn == 0)
340 qp = rcu_dereference(ibp->qp0);
341 else
342 qp = rcu_dereference(ibp->qp1);
343 } else {
344 struct qib_ibdev *dev = &ppd_from_ibp(ibp)->dd->verbs_dev;
345 unsigned n = qpn_hash(dev, qpn);
346
347 rcu_read_lock();
348 for (qp = rcu_dereference(dev->qp_table[n]); qp;
349 qp = rcu_dereference(qp->next))
350 if (qp->ibqp.qp_num == qpn)
351 break;
352 }
353 if (qp)
354 if (unlikely(!atomic_inc_not_zero(&qp->refcount)))
355 qp = NULL;
356
357 rcu_read_unlock();
358 return qp;
359 }
360
361 /**
362 * qib_reset_qp - initialize the QP state to the reset state
363 * @qp: the QP to reset
364 * @type: the QP type
365 */
qib_reset_qp(struct qib_qp * qp,enum ib_qp_type type)366 static void qib_reset_qp(struct qib_qp *qp, enum ib_qp_type type)
367 {
368 qp->remote_qpn = 0;
369 qp->qkey = 0;
370 qp->qp_access_flags = 0;
371 atomic_set(&qp->s_dma_busy, 0);
372 qp->s_flags &= QIB_S_SIGNAL_REQ_WR;
373 qp->s_hdrwords = 0;
374 qp->s_wqe = NULL;
375 qp->s_draining = 0;
376 qp->s_next_psn = 0;
377 qp->s_last_psn = 0;
378 qp->s_sending_psn = 0;
379 qp->s_sending_hpsn = 0;
380 qp->s_psn = 0;
381 qp->r_psn = 0;
382 qp->r_msn = 0;
383 if (type == IB_QPT_RC) {
384 qp->s_state = IB_OPCODE_RC_SEND_LAST;
385 qp->r_state = IB_OPCODE_RC_SEND_LAST;
386 } else {
387 qp->s_state = IB_OPCODE_UC_SEND_LAST;
388 qp->r_state = IB_OPCODE_UC_SEND_LAST;
389 }
390 qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
391 qp->r_nak_state = 0;
392 qp->r_aflags = 0;
393 qp->r_flags = 0;
394 qp->s_head = 0;
395 qp->s_tail = 0;
396 qp->s_cur = 0;
397 qp->s_acked = 0;
398 qp->s_last = 0;
399 qp->s_ssn = 1;
400 qp->s_lsn = 0;
401 qp->s_mig_state = IB_MIG_MIGRATED;
402 memset(qp->s_ack_queue, 0, sizeof(qp->s_ack_queue));
403 qp->r_head_ack_queue = 0;
404 qp->s_tail_ack_queue = 0;
405 qp->s_num_rd_atomic = 0;
406 if (qp->r_rq.wq) {
407 qp->r_rq.wq->head = 0;
408 qp->r_rq.wq->tail = 0;
409 }
410 qp->r_sge.num_sge = 0;
411 }
412
clear_mr_refs(struct qib_qp * qp,int clr_sends)413 static void clear_mr_refs(struct qib_qp *qp, int clr_sends)
414 {
415 unsigned n;
416
417 if (test_and_clear_bit(QIB_R_REWIND_SGE, &qp->r_aflags))
418 qib_put_ss(&qp->s_rdma_read_sge);
419
420 qib_put_ss(&qp->r_sge);
421
422 if (clr_sends) {
423 while (qp->s_last != qp->s_head) {
424 struct qib_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
425 unsigned i;
426
427 for (i = 0; i < wqe->wr.num_sge; i++) {
428 struct qib_sge *sge = &wqe->sg_list[i];
429
430 qib_put_mr(sge->mr);
431 }
432 if (qp->ibqp.qp_type == IB_QPT_UD ||
433 qp->ibqp.qp_type == IB_QPT_SMI ||
434 qp->ibqp.qp_type == IB_QPT_GSI)
435 atomic_dec(&to_iah(wqe->wr.wr.ud.ah)->refcount);
436 if (++qp->s_last >= qp->s_size)
437 qp->s_last = 0;
438 }
439 if (qp->s_rdma_mr) {
440 qib_put_mr(qp->s_rdma_mr);
441 qp->s_rdma_mr = NULL;
442 }
443 }
444
445 if (qp->ibqp.qp_type != IB_QPT_RC)
446 return;
447
448 for (n = 0; n < ARRAY_SIZE(qp->s_ack_queue); n++) {
449 struct qib_ack_entry *e = &qp->s_ack_queue[n];
450
451 if (e->opcode == IB_OPCODE_RC_RDMA_READ_REQUEST &&
452 e->rdma_sge.mr) {
453 qib_put_mr(e->rdma_sge.mr);
454 e->rdma_sge.mr = NULL;
455 }
456 }
457 }
458
459 /**
460 * qib_error_qp - put a QP into the error state
461 * @qp: the QP to put into the error state
462 * @err: the receive completion error to signal if a RWQE is active
463 *
464 * Flushes both send and receive work queues.
465 * Returns true if last WQE event should be generated.
466 * The QP r_lock and s_lock should be held and interrupts disabled.
467 * If we are already in error state, just return.
468 */
qib_error_qp(struct qib_qp * qp,enum ib_wc_status err)469 int qib_error_qp(struct qib_qp *qp, enum ib_wc_status err)
470 {
471 struct qib_ibdev *dev = to_idev(qp->ibqp.device);
472 struct ib_wc wc;
473 int ret = 0;
474
475 if (qp->state == IB_QPS_ERR || qp->state == IB_QPS_RESET)
476 goto bail;
477
478 qp->state = IB_QPS_ERR;
479
480 if (qp->s_flags & (QIB_S_TIMER | QIB_S_WAIT_RNR)) {
481 qp->s_flags &= ~(QIB_S_TIMER | QIB_S_WAIT_RNR);
482 del_timer(&qp->s_timer);
483 }
484
485 if (qp->s_flags & QIB_S_ANY_WAIT_SEND)
486 qp->s_flags &= ~QIB_S_ANY_WAIT_SEND;
487
488 spin_lock(&dev->pending_lock);
489 if (!list_empty(&qp->iowait) && !(qp->s_flags & QIB_S_BUSY)) {
490 qp->s_flags &= ~QIB_S_ANY_WAIT_IO;
491 list_del_init(&qp->iowait);
492 }
493 spin_unlock(&dev->pending_lock);
494
495 if (!(qp->s_flags & QIB_S_BUSY)) {
496 qp->s_hdrwords = 0;
497 if (qp->s_rdma_mr) {
498 qib_put_mr(qp->s_rdma_mr);
499 qp->s_rdma_mr = NULL;
500 }
501 if (qp->s_tx) {
502 qib_put_txreq(qp->s_tx);
503 qp->s_tx = NULL;
504 }
505 }
506
507 /* Schedule the sending tasklet to drain the send work queue. */
508 if (qp->s_last != qp->s_head)
509 qib_schedule_send(qp);
510
511 clear_mr_refs(qp, 0);
512
513 memset(&wc, 0, sizeof(wc));
514 wc.qp = &qp->ibqp;
515 wc.opcode = IB_WC_RECV;
516
517 if (test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags)) {
518 wc.wr_id = qp->r_wr_id;
519 wc.status = err;
520 qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
521 }
522 wc.status = IB_WC_WR_FLUSH_ERR;
523
524 if (qp->r_rq.wq) {
525 struct qib_rwq *wq;
526 u32 head;
527 u32 tail;
528
529 spin_lock(&qp->r_rq.lock);
530
531 /* sanity check pointers before trusting them */
532 wq = qp->r_rq.wq;
533 head = wq->head;
534 if (head >= qp->r_rq.size)
535 head = 0;
536 tail = wq->tail;
537 if (tail >= qp->r_rq.size)
538 tail = 0;
539 while (tail != head) {
540 wc.wr_id = get_rwqe_ptr(&qp->r_rq, tail)->wr_id;
541 if (++tail >= qp->r_rq.size)
542 tail = 0;
543 qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
544 }
545 wq->tail = tail;
546
547 spin_unlock(&qp->r_rq.lock);
548 } else if (qp->ibqp.event_handler)
549 ret = 1;
550
551 bail:
552 return ret;
553 }
554
555 /**
556 * qib_modify_qp - modify the attributes of a queue pair
557 * @ibqp: the queue pair who's attributes we're modifying
558 * @attr: the new attributes
559 * @attr_mask: the mask of attributes to modify
560 * @udata: user data for libibverbs.so
561 *
562 * Returns 0 on success, otherwise returns an errno.
563 */
qib_modify_qp(struct ib_qp * ibqp,struct ib_qp_attr * attr,int attr_mask,struct ib_udata * udata)564 int qib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
565 int attr_mask, struct ib_udata *udata)
566 {
567 struct qib_ibdev *dev = to_idev(ibqp->device);
568 struct qib_qp *qp = to_iqp(ibqp);
569 enum ib_qp_state cur_state, new_state;
570 struct ib_event ev;
571 int lastwqe = 0;
572 int mig = 0;
573 int ret;
574 u32 pmtu = 0; /* for gcc warning only */
575
576 spin_lock_irq(&qp->r_lock);
577 spin_lock(&qp->s_lock);
578
579 cur_state = attr_mask & IB_QP_CUR_STATE ?
580 attr->cur_qp_state : qp->state;
581 new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;
582
583 if (!ib_modify_qp_is_ok(cur_state, new_state, ibqp->qp_type,
584 attr_mask))
585 goto inval;
586
587 if (attr_mask & IB_QP_AV) {
588 if (attr->ah_attr.dlid >= QIB_MULTICAST_LID_BASE)
589 goto inval;
590 if (qib_check_ah(qp->ibqp.device, &attr->ah_attr))
591 goto inval;
592 }
593
594 if (attr_mask & IB_QP_ALT_PATH) {
595 if (attr->alt_ah_attr.dlid >= QIB_MULTICAST_LID_BASE)
596 goto inval;
597 if (qib_check_ah(qp->ibqp.device, &attr->alt_ah_attr))
598 goto inval;
599 if (attr->alt_pkey_index >= qib_get_npkeys(dd_from_dev(dev)))
600 goto inval;
601 }
602
603 if (attr_mask & IB_QP_PKEY_INDEX)
604 if (attr->pkey_index >= qib_get_npkeys(dd_from_dev(dev)))
605 goto inval;
606
607 if (attr_mask & IB_QP_MIN_RNR_TIMER)
608 if (attr->min_rnr_timer > 31)
609 goto inval;
610
611 if (attr_mask & IB_QP_PORT)
612 if (qp->ibqp.qp_type == IB_QPT_SMI ||
613 qp->ibqp.qp_type == IB_QPT_GSI ||
614 attr->port_num == 0 ||
615 attr->port_num > ibqp->device->phys_port_cnt)
616 goto inval;
617
618 if (attr_mask & IB_QP_DEST_QPN)
619 if (attr->dest_qp_num > QIB_QPN_MASK)
620 goto inval;
621
622 if (attr_mask & IB_QP_RETRY_CNT)
623 if (attr->retry_cnt > 7)
624 goto inval;
625
626 if (attr_mask & IB_QP_RNR_RETRY)
627 if (attr->rnr_retry > 7)
628 goto inval;
629
630 /*
631 * Don't allow invalid path_mtu values. OK to set greater
632 * than the active mtu (or even the max_cap, if we have tuned
633 * that to a small mtu. We'll set qp->path_mtu
634 * to the lesser of requested attribute mtu and active,
635 * for packetizing messages.
636 * Note that the QP port has to be set in INIT and MTU in RTR.
637 */
638 if (attr_mask & IB_QP_PATH_MTU) {
639 struct qib_devdata *dd = dd_from_dev(dev);
640 int mtu, pidx = qp->port_num - 1;
641
642 mtu = ib_mtu_enum_to_int(attr->path_mtu);
643 if (mtu == -1)
644 goto inval;
645 if (mtu > dd->pport[pidx].ibmtu) {
646 switch (dd->pport[pidx].ibmtu) {
647 case 4096:
648 pmtu = IB_MTU_4096;
649 break;
650 case 2048:
651 pmtu = IB_MTU_2048;
652 break;
653 case 1024:
654 pmtu = IB_MTU_1024;
655 break;
656 case 512:
657 pmtu = IB_MTU_512;
658 break;
659 case 256:
660 pmtu = IB_MTU_256;
661 break;
662 default:
663 pmtu = IB_MTU_2048;
664 }
665 } else
666 pmtu = attr->path_mtu;
667 }
668
669 if (attr_mask & IB_QP_PATH_MIG_STATE) {
670 if (attr->path_mig_state == IB_MIG_REARM) {
671 if (qp->s_mig_state == IB_MIG_ARMED)
672 goto inval;
673 if (new_state != IB_QPS_RTS)
674 goto inval;
675 } else if (attr->path_mig_state == IB_MIG_MIGRATED) {
676 if (qp->s_mig_state == IB_MIG_REARM)
677 goto inval;
678 if (new_state != IB_QPS_RTS && new_state != IB_QPS_SQD)
679 goto inval;
680 if (qp->s_mig_state == IB_MIG_ARMED)
681 mig = 1;
682 } else
683 goto inval;
684 }
685
686 if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
687 if (attr->max_dest_rd_atomic > QIB_MAX_RDMA_ATOMIC)
688 goto inval;
689
690 switch (new_state) {
691 case IB_QPS_RESET:
692 if (qp->state != IB_QPS_RESET) {
693 qp->state = IB_QPS_RESET;
694 spin_lock(&dev->pending_lock);
695 if (!list_empty(&qp->iowait))
696 list_del_init(&qp->iowait);
697 spin_unlock(&dev->pending_lock);
698 qp->s_flags &= ~(QIB_S_TIMER | QIB_S_ANY_WAIT);
699 spin_unlock(&qp->s_lock);
700 spin_unlock_irq(&qp->r_lock);
701 /* Stop the sending work queue and retry timer */
702 cancel_work_sync(&qp->s_work);
703 del_timer_sync(&qp->s_timer);
704 wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
705 if (qp->s_tx) {
706 qib_put_txreq(qp->s_tx);
707 qp->s_tx = NULL;
708 }
709 remove_qp(dev, qp);
710 wait_event(qp->wait, !atomic_read(&qp->refcount));
711 spin_lock_irq(&qp->r_lock);
712 spin_lock(&qp->s_lock);
713 clear_mr_refs(qp, 1);
714 qib_reset_qp(qp, ibqp->qp_type);
715 }
716 break;
717
718 case IB_QPS_RTR:
719 /* Allow event to retrigger if QP set to RTR more than once */
720 qp->r_flags &= ~QIB_R_COMM_EST;
721 qp->state = new_state;
722 break;
723
724 case IB_QPS_SQD:
725 qp->s_draining = qp->s_last != qp->s_cur;
726 qp->state = new_state;
727 break;
728
729 case IB_QPS_SQE:
730 if (qp->ibqp.qp_type == IB_QPT_RC)
731 goto inval;
732 qp->state = new_state;
733 break;
734
735 case IB_QPS_ERR:
736 lastwqe = qib_error_qp(qp, IB_WC_WR_FLUSH_ERR);
737 break;
738
739 default:
740 qp->state = new_state;
741 break;
742 }
743
744 if (attr_mask & IB_QP_PKEY_INDEX)
745 qp->s_pkey_index = attr->pkey_index;
746
747 if (attr_mask & IB_QP_PORT)
748 qp->port_num = attr->port_num;
749
750 if (attr_mask & IB_QP_DEST_QPN)
751 qp->remote_qpn = attr->dest_qp_num;
752
753 if (attr_mask & IB_QP_SQ_PSN) {
754 qp->s_next_psn = attr->sq_psn & QIB_PSN_MASK;
755 qp->s_psn = qp->s_next_psn;
756 qp->s_sending_psn = qp->s_next_psn;
757 qp->s_last_psn = qp->s_next_psn - 1;
758 qp->s_sending_hpsn = qp->s_last_psn;
759 }
760
761 if (attr_mask & IB_QP_RQ_PSN)
762 qp->r_psn = attr->rq_psn & QIB_PSN_MASK;
763
764 if (attr_mask & IB_QP_ACCESS_FLAGS)
765 qp->qp_access_flags = attr->qp_access_flags;
766
767 if (attr_mask & IB_QP_AV) {
768 qp->remote_ah_attr = attr->ah_attr;
769 qp->s_srate = attr->ah_attr.static_rate;
770 }
771
772 if (attr_mask & IB_QP_ALT_PATH) {
773 qp->alt_ah_attr = attr->alt_ah_attr;
774 qp->s_alt_pkey_index = attr->alt_pkey_index;
775 }
776
777 if (attr_mask & IB_QP_PATH_MIG_STATE) {
778 qp->s_mig_state = attr->path_mig_state;
779 if (mig) {
780 qp->remote_ah_attr = qp->alt_ah_attr;
781 qp->port_num = qp->alt_ah_attr.port_num;
782 qp->s_pkey_index = qp->s_alt_pkey_index;
783 }
784 }
785
786 if (attr_mask & IB_QP_PATH_MTU) {
787 qp->path_mtu = pmtu;
788 qp->pmtu = ib_mtu_enum_to_int(pmtu);
789 }
790
791 if (attr_mask & IB_QP_RETRY_CNT) {
792 qp->s_retry_cnt = attr->retry_cnt;
793 qp->s_retry = attr->retry_cnt;
794 }
795
796 if (attr_mask & IB_QP_RNR_RETRY) {
797 qp->s_rnr_retry_cnt = attr->rnr_retry;
798 qp->s_rnr_retry = attr->rnr_retry;
799 }
800
801 if (attr_mask & IB_QP_MIN_RNR_TIMER)
802 qp->r_min_rnr_timer = attr->min_rnr_timer;
803
804 if (attr_mask & IB_QP_TIMEOUT) {
805 qp->timeout = attr->timeout;
806 qp->timeout_jiffies =
807 usecs_to_jiffies((4096UL * (1UL << qp->timeout)) /
808 1000UL);
809 }
810
811 if (attr_mask & IB_QP_QKEY)
812 qp->qkey = attr->qkey;
813
814 if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
815 qp->r_max_rd_atomic = attr->max_dest_rd_atomic;
816
817 if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC)
818 qp->s_max_rd_atomic = attr->max_rd_atomic;
819
820 spin_unlock(&qp->s_lock);
821 spin_unlock_irq(&qp->r_lock);
822
823 if (cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT)
824 insert_qp(dev, qp);
825
826 if (lastwqe) {
827 ev.device = qp->ibqp.device;
828 ev.element.qp = &qp->ibqp;
829 ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
830 qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
831 }
832 if (mig) {
833 ev.device = qp->ibqp.device;
834 ev.element.qp = &qp->ibqp;
835 ev.event = IB_EVENT_PATH_MIG;
836 qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
837 }
838 ret = 0;
839 goto bail;
840
841 inval:
842 spin_unlock(&qp->s_lock);
843 spin_unlock_irq(&qp->r_lock);
844 ret = -EINVAL;
845
846 bail:
847 return ret;
848 }
849
qib_query_qp(struct ib_qp * ibqp,struct ib_qp_attr * attr,int attr_mask,struct ib_qp_init_attr * init_attr)850 int qib_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
851 int attr_mask, struct ib_qp_init_attr *init_attr)
852 {
853 struct qib_qp *qp = to_iqp(ibqp);
854
855 attr->qp_state = qp->state;
856 attr->cur_qp_state = attr->qp_state;
857 attr->path_mtu = qp->path_mtu;
858 attr->path_mig_state = qp->s_mig_state;
859 attr->qkey = qp->qkey;
860 attr->rq_psn = qp->r_psn & QIB_PSN_MASK;
861 attr->sq_psn = qp->s_next_psn & QIB_PSN_MASK;
862 attr->dest_qp_num = qp->remote_qpn;
863 attr->qp_access_flags = qp->qp_access_flags;
864 attr->cap.max_send_wr = qp->s_size - 1;
865 attr->cap.max_recv_wr = qp->ibqp.srq ? 0 : qp->r_rq.size - 1;
866 attr->cap.max_send_sge = qp->s_max_sge;
867 attr->cap.max_recv_sge = qp->r_rq.max_sge;
868 attr->cap.max_inline_data = 0;
869 attr->ah_attr = qp->remote_ah_attr;
870 attr->alt_ah_attr = qp->alt_ah_attr;
871 attr->pkey_index = qp->s_pkey_index;
872 attr->alt_pkey_index = qp->s_alt_pkey_index;
873 attr->en_sqd_async_notify = 0;
874 attr->sq_draining = qp->s_draining;
875 attr->max_rd_atomic = qp->s_max_rd_atomic;
876 attr->max_dest_rd_atomic = qp->r_max_rd_atomic;
877 attr->min_rnr_timer = qp->r_min_rnr_timer;
878 attr->port_num = qp->port_num;
879 attr->timeout = qp->timeout;
880 attr->retry_cnt = qp->s_retry_cnt;
881 attr->rnr_retry = qp->s_rnr_retry_cnt;
882 attr->alt_port_num = qp->alt_ah_attr.port_num;
883 attr->alt_timeout = qp->alt_timeout;
884
885 init_attr->event_handler = qp->ibqp.event_handler;
886 init_attr->qp_context = qp->ibqp.qp_context;
887 init_attr->send_cq = qp->ibqp.send_cq;
888 init_attr->recv_cq = qp->ibqp.recv_cq;
889 init_attr->srq = qp->ibqp.srq;
890 init_attr->cap = attr->cap;
891 if (qp->s_flags & QIB_S_SIGNAL_REQ_WR)
892 init_attr->sq_sig_type = IB_SIGNAL_REQ_WR;
893 else
894 init_attr->sq_sig_type = IB_SIGNAL_ALL_WR;
895 init_attr->qp_type = qp->ibqp.qp_type;
896 init_attr->port_num = qp->port_num;
897 return 0;
898 }
899
900 /**
901 * qib_compute_aeth - compute the AETH (syndrome + MSN)
902 * @qp: the queue pair to compute the AETH for
903 *
904 * Returns the AETH.
905 */
qib_compute_aeth(struct qib_qp * qp)906 __be32 qib_compute_aeth(struct qib_qp *qp)
907 {
908 u32 aeth = qp->r_msn & QIB_MSN_MASK;
909
910 if (qp->ibqp.srq) {
911 /*
912 * Shared receive queues don't generate credits.
913 * Set the credit field to the invalid value.
914 */
915 aeth |= QIB_AETH_CREDIT_INVAL << QIB_AETH_CREDIT_SHIFT;
916 } else {
917 u32 min, max, x;
918 u32 credits;
919 struct qib_rwq *wq = qp->r_rq.wq;
920 u32 head;
921 u32 tail;
922
923 /* sanity check pointers before trusting them */
924 head = wq->head;
925 if (head >= qp->r_rq.size)
926 head = 0;
927 tail = wq->tail;
928 if (tail >= qp->r_rq.size)
929 tail = 0;
930 /*
931 * Compute the number of credits available (RWQEs).
932 * XXX Not holding the r_rq.lock here so there is a small
933 * chance that the pair of reads are not atomic.
934 */
935 credits = head - tail;
936 if ((int)credits < 0)
937 credits += qp->r_rq.size;
938 /*
939 * Binary search the credit table to find the code to
940 * use.
941 */
942 min = 0;
943 max = 31;
944 for (;;) {
945 x = (min + max) / 2;
946 if (credit_table[x] == credits)
947 break;
948 if (credit_table[x] > credits)
949 max = x;
950 else if (min == x)
951 break;
952 else
953 min = x;
954 }
955 aeth |= x << QIB_AETH_CREDIT_SHIFT;
956 }
957 return cpu_to_be32(aeth);
958 }
959
960 /**
961 * qib_create_qp - create a queue pair for a device
962 * @ibpd: the protection domain who's device we create the queue pair for
963 * @init_attr: the attributes of the queue pair
964 * @udata: user data for libibverbs.so
965 *
966 * Returns the queue pair on success, otherwise returns an errno.
967 *
968 * Called by the ib_create_qp() core verbs function.
969 */
qib_create_qp(struct ib_pd * ibpd,struct ib_qp_init_attr * init_attr,struct ib_udata * udata)970 struct ib_qp *qib_create_qp(struct ib_pd *ibpd,
971 struct ib_qp_init_attr *init_attr,
972 struct ib_udata *udata)
973 {
974 struct qib_qp *qp;
975 int err;
976 struct qib_swqe *swq = NULL;
977 struct qib_ibdev *dev;
978 struct qib_devdata *dd;
979 size_t sz;
980 size_t sg_list_sz;
981 struct ib_qp *ret;
982
983 if (init_attr->cap.max_send_sge > ib_qib_max_sges ||
984 init_attr->cap.max_send_wr > ib_qib_max_qp_wrs) {
985 ret = ERR_PTR(-EINVAL);
986 goto bail;
987 }
988
989 /* Check receive queue parameters if no SRQ is specified. */
990 if (!init_attr->srq) {
991 if (init_attr->cap.max_recv_sge > ib_qib_max_sges ||
992 init_attr->cap.max_recv_wr > ib_qib_max_qp_wrs) {
993 ret = ERR_PTR(-EINVAL);
994 goto bail;
995 }
996 if (init_attr->cap.max_send_sge +
997 init_attr->cap.max_send_wr +
998 init_attr->cap.max_recv_sge +
999 init_attr->cap.max_recv_wr == 0) {
1000 ret = ERR_PTR(-EINVAL);
1001 goto bail;
1002 }
1003 }
1004
1005 switch (init_attr->qp_type) {
1006 case IB_QPT_SMI:
1007 case IB_QPT_GSI:
1008 if (init_attr->port_num == 0 ||
1009 init_attr->port_num > ibpd->device->phys_port_cnt) {
1010 ret = ERR_PTR(-EINVAL);
1011 goto bail;
1012 }
1013 case IB_QPT_UC:
1014 case IB_QPT_RC:
1015 case IB_QPT_UD:
1016 sz = sizeof(struct qib_sge) *
1017 init_attr->cap.max_send_sge +
1018 sizeof(struct qib_swqe);
1019 swq = vmalloc((init_attr->cap.max_send_wr + 1) * sz);
1020 if (swq == NULL) {
1021 ret = ERR_PTR(-ENOMEM);
1022 goto bail;
1023 }
1024 sz = sizeof(*qp);
1025 sg_list_sz = 0;
1026 if (init_attr->srq) {
1027 struct qib_srq *srq = to_isrq(init_attr->srq);
1028
1029 if (srq->rq.max_sge > 1)
1030 sg_list_sz = sizeof(*qp->r_sg_list) *
1031 (srq->rq.max_sge - 1);
1032 } else if (init_attr->cap.max_recv_sge > 1)
1033 sg_list_sz = sizeof(*qp->r_sg_list) *
1034 (init_attr->cap.max_recv_sge - 1);
1035 qp = kzalloc(sz + sg_list_sz, GFP_KERNEL);
1036 if (!qp) {
1037 ret = ERR_PTR(-ENOMEM);
1038 goto bail_swq;
1039 }
1040 RCU_INIT_POINTER(qp->next, NULL);
1041 qp->s_hdr = kzalloc(sizeof(*qp->s_hdr), GFP_KERNEL);
1042 if (!qp->s_hdr) {
1043 ret = ERR_PTR(-ENOMEM);
1044 goto bail_qp;
1045 }
1046 qp->timeout_jiffies =
1047 usecs_to_jiffies((4096UL * (1UL << qp->timeout)) /
1048 1000UL);
1049 if (init_attr->srq)
1050 sz = 0;
1051 else {
1052 qp->r_rq.size = init_attr->cap.max_recv_wr + 1;
1053 qp->r_rq.max_sge = init_attr->cap.max_recv_sge;
1054 sz = (sizeof(struct ib_sge) * qp->r_rq.max_sge) +
1055 sizeof(struct qib_rwqe);
1056 qp->r_rq.wq = vmalloc_user(sizeof(struct qib_rwq) +
1057 qp->r_rq.size * sz);
1058 if (!qp->r_rq.wq) {
1059 ret = ERR_PTR(-ENOMEM);
1060 goto bail_qp;
1061 }
1062 }
1063
1064 /*
1065 * ib_create_qp() will initialize qp->ibqp
1066 * except for qp->ibqp.qp_num.
1067 */
1068 spin_lock_init(&qp->r_lock);
1069 spin_lock_init(&qp->s_lock);
1070 spin_lock_init(&qp->r_rq.lock);
1071 atomic_set(&qp->refcount, 0);
1072 init_waitqueue_head(&qp->wait);
1073 init_waitqueue_head(&qp->wait_dma);
1074 init_timer(&qp->s_timer);
1075 qp->s_timer.data = (unsigned long)qp;
1076 INIT_WORK(&qp->s_work, qib_do_send);
1077 INIT_LIST_HEAD(&qp->iowait);
1078 INIT_LIST_HEAD(&qp->rspwait);
1079 qp->state = IB_QPS_RESET;
1080 qp->s_wq = swq;
1081 qp->s_size = init_attr->cap.max_send_wr + 1;
1082 qp->s_max_sge = init_attr->cap.max_send_sge;
1083 if (init_attr->sq_sig_type == IB_SIGNAL_REQ_WR)
1084 qp->s_flags = QIB_S_SIGNAL_REQ_WR;
1085 dev = to_idev(ibpd->device);
1086 dd = dd_from_dev(dev);
1087 err = alloc_qpn(dd, &dev->qpn_table, init_attr->qp_type,
1088 init_attr->port_num);
1089 if (err < 0) {
1090 ret = ERR_PTR(err);
1091 vfree(qp->r_rq.wq);
1092 goto bail_qp;
1093 }
1094 qp->ibqp.qp_num = err;
1095 qp->port_num = init_attr->port_num;
1096 qib_reset_qp(qp, init_attr->qp_type);
1097 break;
1098
1099 default:
1100 /* Don't support raw QPs */
1101 ret = ERR_PTR(-ENOSYS);
1102 goto bail;
1103 }
1104
1105 init_attr->cap.max_inline_data = 0;
1106
1107 /*
1108 * Return the address of the RWQ as the offset to mmap.
1109 * See qib_mmap() for details.
1110 */
1111 if (udata && udata->outlen >= sizeof(__u64)) {
1112 if (!qp->r_rq.wq) {
1113 __u64 offset = 0;
1114
1115 err = ib_copy_to_udata(udata, &offset,
1116 sizeof(offset));
1117 if (err) {
1118 ret = ERR_PTR(err);
1119 goto bail_ip;
1120 }
1121 } else {
1122 u32 s = sizeof(struct qib_rwq) + qp->r_rq.size * sz;
1123
1124 qp->ip = qib_create_mmap_info(dev, s,
1125 ibpd->uobject->context,
1126 qp->r_rq.wq);
1127 if (!qp->ip) {
1128 ret = ERR_PTR(-ENOMEM);
1129 goto bail_ip;
1130 }
1131
1132 err = ib_copy_to_udata(udata, &(qp->ip->offset),
1133 sizeof(qp->ip->offset));
1134 if (err) {
1135 ret = ERR_PTR(err);
1136 goto bail_ip;
1137 }
1138 }
1139 }
1140
1141 spin_lock(&dev->n_qps_lock);
1142 if (dev->n_qps_allocated == ib_qib_max_qps) {
1143 spin_unlock(&dev->n_qps_lock);
1144 ret = ERR_PTR(-ENOMEM);
1145 goto bail_ip;
1146 }
1147
1148 dev->n_qps_allocated++;
1149 spin_unlock(&dev->n_qps_lock);
1150
1151 if (qp->ip) {
1152 spin_lock_irq(&dev->pending_lock);
1153 list_add(&qp->ip->pending_mmaps, &dev->pending_mmaps);
1154 spin_unlock_irq(&dev->pending_lock);
1155 }
1156
1157 ret = &qp->ibqp;
1158 goto bail;
1159
1160 bail_ip:
1161 if (qp->ip)
1162 kref_put(&qp->ip->ref, qib_release_mmap_info);
1163 else
1164 vfree(qp->r_rq.wq);
1165 free_qpn(&dev->qpn_table, qp->ibqp.qp_num);
1166 bail_qp:
1167 kfree(qp->s_hdr);
1168 kfree(qp);
1169 bail_swq:
1170 vfree(swq);
1171 bail:
1172 return ret;
1173 }
1174
1175 /**
1176 * qib_destroy_qp - destroy a queue pair
1177 * @ibqp: the queue pair to destroy
1178 *
1179 * Returns 0 on success.
1180 *
1181 * Note that this can be called while the QP is actively sending or
1182 * receiving!
1183 */
qib_destroy_qp(struct ib_qp * ibqp)1184 int qib_destroy_qp(struct ib_qp *ibqp)
1185 {
1186 struct qib_qp *qp = to_iqp(ibqp);
1187 struct qib_ibdev *dev = to_idev(ibqp->device);
1188
1189 /* Make sure HW and driver activity is stopped. */
1190 spin_lock_irq(&qp->s_lock);
1191 if (qp->state != IB_QPS_RESET) {
1192 qp->state = IB_QPS_RESET;
1193 spin_lock(&dev->pending_lock);
1194 if (!list_empty(&qp->iowait))
1195 list_del_init(&qp->iowait);
1196 spin_unlock(&dev->pending_lock);
1197 qp->s_flags &= ~(QIB_S_TIMER | QIB_S_ANY_WAIT);
1198 spin_unlock_irq(&qp->s_lock);
1199 cancel_work_sync(&qp->s_work);
1200 del_timer_sync(&qp->s_timer);
1201 wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
1202 if (qp->s_tx) {
1203 qib_put_txreq(qp->s_tx);
1204 qp->s_tx = NULL;
1205 }
1206 remove_qp(dev, qp);
1207 wait_event(qp->wait, !atomic_read(&qp->refcount));
1208 clear_mr_refs(qp, 1);
1209 } else
1210 spin_unlock_irq(&qp->s_lock);
1211
1212 /* all user's cleaned up, mark it available */
1213 free_qpn(&dev->qpn_table, qp->ibqp.qp_num);
1214 spin_lock(&dev->n_qps_lock);
1215 dev->n_qps_allocated--;
1216 spin_unlock(&dev->n_qps_lock);
1217
1218 if (qp->ip)
1219 kref_put(&qp->ip->ref, qib_release_mmap_info);
1220 else
1221 vfree(qp->r_rq.wq);
1222 vfree(qp->s_wq);
1223 kfree(qp->s_hdr);
1224 kfree(qp);
1225 return 0;
1226 }
1227
1228 /**
1229 * qib_init_qpn_table - initialize the QP number table for a device
1230 * @qpt: the QPN table
1231 */
qib_init_qpn_table(struct qib_devdata * dd,struct qib_qpn_table * qpt)1232 void qib_init_qpn_table(struct qib_devdata *dd, struct qib_qpn_table *qpt)
1233 {
1234 spin_lock_init(&qpt->lock);
1235 qpt->last = 1; /* start with QPN 2 */
1236 qpt->nmaps = 1;
1237 qpt->mask = dd->qpn_mask;
1238 }
1239
1240 /**
1241 * qib_free_qpn_table - free the QP number table for a device
1242 * @qpt: the QPN table
1243 */
qib_free_qpn_table(struct qib_qpn_table * qpt)1244 void qib_free_qpn_table(struct qib_qpn_table *qpt)
1245 {
1246 int i;
1247
1248 for (i = 0; i < ARRAY_SIZE(qpt->map); i++)
1249 if (qpt->map[i].page)
1250 free_page((unsigned long) qpt->map[i].page);
1251 }
1252
1253 /**
1254 * qib_get_credit - flush the send work queue of a QP
1255 * @qp: the qp who's send work queue to flush
1256 * @aeth: the Acknowledge Extended Transport Header
1257 *
1258 * The QP s_lock should be held.
1259 */
qib_get_credit(struct qib_qp * qp,u32 aeth)1260 void qib_get_credit(struct qib_qp *qp, u32 aeth)
1261 {
1262 u32 credit = (aeth >> QIB_AETH_CREDIT_SHIFT) & QIB_AETH_CREDIT_MASK;
1263
1264 /*
1265 * If the credit is invalid, we can send
1266 * as many packets as we like. Otherwise, we have to
1267 * honor the credit field.
1268 */
1269 if (credit == QIB_AETH_CREDIT_INVAL) {
1270 if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) {
1271 qp->s_flags |= QIB_S_UNLIMITED_CREDIT;
1272 if (qp->s_flags & QIB_S_WAIT_SSN_CREDIT) {
1273 qp->s_flags &= ~QIB_S_WAIT_SSN_CREDIT;
1274 qib_schedule_send(qp);
1275 }
1276 }
1277 } else if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) {
1278 /* Compute new LSN (i.e., MSN + credit) */
1279 credit = (aeth + credit_table[credit]) & QIB_MSN_MASK;
1280 if (qib_cmp24(credit, qp->s_lsn) > 0) {
1281 qp->s_lsn = credit;
1282 if (qp->s_flags & QIB_S_WAIT_SSN_CREDIT) {
1283 qp->s_flags &= ~QIB_S_WAIT_SSN_CREDIT;
1284 qib_schedule_send(qp);
1285 }
1286 }
1287 }
1288 }
1289