xref: /openbmc/linux/drivers/infiniband/hw/qib/qib_qp.c (revision 9d749629)
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 
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 
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 
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  */
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 
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 
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  */
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  */
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 				*qpp = qp->next;
272 				rcu_assign_pointer(qp->next, NULL);
273 				break;
274 			}
275 	}
276 
277 	spin_unlock_irqrestore(&dev->qpt_lock, flags);
278 	synchronize_rcu();
279 }
280 
281 /**
282  * qib_free_all_qps - check for QPs still in use
283  * @qpt: the QP table to empty
284  *
285  * There should not be any QPs still in use.
286  * Free memory for table.
287  */
288 unsigned qib_free_all_qps(struct qib_devdata *dd)
289 {
290 	struct qib_ibdev *dev = &dd->verbs_dev;
291 	unsigned long flags;
292 	struct qib_qp *qp;
293 	unsigned n, qp_inuse = 0;
294 
295 	for (n = 0; n < dd->num_pports; n++) {
296 		struct qib_ibport *ibp = &dd->pport[n].ibport_data;
297 
298 		if (!qib_mcast_tree_empty(ibp))
299 			qp_inuse++;
300 		rcu_read_lock();
301 		if (rcu_dereference(ibp->qp0))
302 			qp_inuse++;
303 		if (rcu_dereference(ibp->qp1))
304 			qp_inuse++;
305 		rcu_read_unlock();
306 	}
307 
308 	spin_lock_irqsave(&dev->qpt_lock, flags);
309 	for (n = 0; n < dev->qp_table_size; n++) {
310 		qp = rcu_dereference_protected(dev->qp_table[n],
311 			lockdep_is_held(&dev->qpt_lock));
312 		rcu_assign_pointer(dev->qp_table[n], NULL);
313 
314 		for (; qp; qp = rcu_dereference_protected(qp->next,
315 					lockdep_is_held(&dev->qpt_lock)))
316 			qp_inuse++;
317 	}
318 	spin_unlock_irqrestore(&dev->qpt_lock, flags);
319 	synchronize_rcu();
320 
321 	return qp_inuse;
322 }
323 
324 /**
325  * qib_lookup_qpn - return the QP with the given QPN
326  * @qpt: the QP table
327  * @qpn: the QP number to look up
328  *
329  * The caller is responsible for decrementing the QP reference count
330  * when done.
331  */
332 struct qib_qp *qib_lookup_qpn(struct qib_ibport *ibp, u32 qpn)
333 {
334 	struct qib_qp *qp = NULL;
335 
336 	if (unlikely(qpn <= 1)) {
337 		rcu_read_lock();
338 		if (qpn == 0)
339 			qp = rcu_dereference(ibp->qp0);
340 		else
341 			qp = rcu_dereference(ibp->qp1);
342 	} else {
343 		struct qib_ibdev *dev = &ppd_from_ibp(ibp)->dd->verbs_dev;
344 		unsigned n = qpn_hash(dev, qpn);
345 
346 		rcu_read_lock();
347 		for (qp = rcu_dereference(dev->qp_table[n]); qp;
348 			qp = rcu_dereference(qp->next))
349 			if (qp->ibqp.qp_num == qpn)
350 				break;
351 	}
352 	if (qp)
353 		if (unlikely(!atomic_inc_not_zero(&qp->refcount)))
354 			qp = NULL;
355 
356 	rcu_read_unlock();
357 	return qp;
358 }
359 
360 /**
361  * qib_reset_qp - initialize the QP state to the reset state
362  * @qp: the QP to reset
363  * @type: the QP type
364  */
365 static void qib_reset_qp(struct qib_qp *qp, enum ib_qp_type type)
366 {
367 	qp->remote_qpn = 0;
368 	qp->qkey = 0;
369 	qp->qp_access_flags = 0;
370 	atomic_set(&qp->s_dma_busy, 0);
371 	qp->s_flags &= QIB_S_SIGNAL_REQ_WR;
372 	qp->s_hdrwords = 0;
373 	qp->s_wqe = NULL;
374 	qp->s_draining = 0;
375 	qp->s_next_psn = 0;
376 	qp->s_last_psn = 0;
377 	qp->s_sending_psn = 0;
378 	qp->s_sending_hpsn = 0;
379 	qp->s_psn = 0;
380 	qp->r_psn = 0;
381 	qp->r_msn = 0;
382 	if (type == IB_QPT_RC) {
383 		qp->s_state = IB_OPCODE_RC_SEND_LAST;
384 		qp->r_state = IB_OPCODE_RC_SEND_LAST;
385 	} else {
386 		qp->s_state = IB_OPCODE_UC_SEND_LAST;
387 		qp->r_state = IB_OPCODE_UC_SEND_LAST;
388 	}
389 	qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
390 	qp->r_nak_state = 0;
391 	qp->r_aflags = 0;
392 	qp->r_flags = 0;
393 	qp->s_head = 0;
394 	qp->s_tail = 0;
395 	qp->s_cur = 0;
396 	qp->s_acked = 0;
397 	qp->s_last = 0;
398 	qp->s_ssn = 1;
399 	qp->s_lsn = 0;
400 	qp->s_mig_state = IB_MIG_MIGRATED;
401 	memset(qp->s_ack_queue, 0, sizeof(qp->s_ack_queue));
402 	qp->r_head_ack_queue = 0;
403 	qp->s_tail_ack_queue = 0;
404 	qp->s_num_rd_atomic = 0;
405 	if (qp->r_rq.wq) {
406 		qp->r_rq.wq->head = 0;
407 		qp->r_rq.wq->tail = 0;
408 	}
409 	qp->r_sge.num_sge = 0;
410 }
411 
412 static void clear_mr_refs(struct qib_qp *qp, int clr_sends)
413 {
414 	unsigned n;
415 
416 	if (test_and_clear_bit(QIB_R_REWIND_SGE, &qp->r_aflags))
417 		qib_put_ss(&qp->s_rdma_read_sge);
418 
419 	qib_put_ss(&qp->r_sge);
420 
421 	if (clr_sends) {
422 		while (qp->s_last != qp->s_head) {
423 			struct qib_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
424 			unsigned i;
425 
426 			for (i = 0; i < wqe->wr.num_sge; i++) {
427 				struct qib_sge *sge = &wqe->sg_list[i];
428 
429 				qib_put_mr(sge->mr);
430 			}
431 			if (qp->ibqp.qp_type == IB_QPT_UD ||
432 			    qp->ibqp.qp_type == IB_QPT_SMI ||
433 			    qp->ibqp.qp_type == IB_QPT_GSI)
434 				atomic_dec(&to_iah(wqe->wr.wr.ud.ah)->refcount);
435 			if (++qp->s_last >= qp->s_size)
436 				qp->s_last = 0;
437 		}
438 		if (qp->s_rdma_mr) {
439 			qib_put_mr(qp->s_rdma_mr);
440 			qp->s_rdma_mr = NULL;
441 		}
442 	}
443 
444 	if (qp->ibqp.qp_type != IB_QPT_RC)
445 		return;
446 
447 	for (n = 0; n < ARRAY_SIZE(qp->s_ack_queue); n++) {
448 		struct qib_ack_entry *e = &qp->s_ack_queue[n];
449 
450 		if (e->opcode == IB_OPCODE_RC_RDMA_READ_REQUEST &&
451 		    e->rdma_sge.mr) {
452 			qib_put_mr(e->rdma_sge.mr);
453 			e->rdma_sge.mr = NULL;
454 		}
455 	}
456 }
457 
458 /**
459  * qib_error_qp - put a QP into the error state
460  * @qp: the QP to put into the error state
461  * @err: the receive completion error to signal if a RWQE is active
462  *
463  * Flushes both send and receive work queues.
464  * Returns true if last WQE event should be generated.
465  * The QP r_lock and s_lock should be held and interrupts disabled.
466  * If we are already in error state, just return.
467  */
468 int qib_error_qp(struct qib_qp *qp, enum ib_wc_status err)
469 {
470 	struct qib_ibdev *dev = to_idev(qp->ibqp.device);
471 	struct ib_wc wc;
472 	int ret = 0;
473 
474 	if (qp->state == IB_QPS_ERR || qp->state == IB_QPS_RESET)
475 		goto bail;
476 
477 	qp->state = IB_QPS_ERR;
478 
479 	if (qp->s_flags & (QIB_S_TIMER | QIB_S_WAIT_RNR)) {
480 		qp->s_flags &= ~(QIB_S_TIMER | QIB_S_WAIT_RNR);
481 		del_timer(&qp->s_timer);
482 	}
483 
484 	if (qp->s_flags & QIB_S_ANY_WAIT_SEND)
485 		qp->s_flags &= ~QIB_S_ANY_WAIT_SEND;
486 
487 	spin_lock(&dev->pending_lock);
488 	if (!list_empty(&qp->iowait) && !(qp->s_flags & QIB_S_BUSY)) {
489 		qp->s_flags &= ~QIB_S_ANY_WAIT_IO;
490 		list_del_init(&qp->iowait);
491 	}
492 	spin_unlock(&dev->pending_lock);
493 
494 	if (!(qp->s_flags & QIB_S_BUSY)) {
495 		qp->s_hdrwords = 0;
496 		if (qp->s_rdma_mr) {
497 			qib_put_mr(qp->s_rdma_mr);
498 			qp->s_rdma_mr = NULL;
499 		}
500 		if (qp->s_tx) {
501 			qib_put_txreq(qp->s_tx);
502 			qp->s_tx = NULL;
503 		}
504 	}
505 
506 	/* Schedule the sending tasklet to drain the send work queue. */
507 	if (qp->s_last != qp->s_head)
508 		qib_schedule_send(qp);
509 
510 	clear_mr_refs(qp, 0);
511 
512 	memset(&wc, 0, sizeof(wc));
513 	wc.qp = &qp->ibqp;
514 	wc.opcode = IB_WC_RECV;
515 
516 	if (test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags)) {
517 		wc.wr_id = qp->r_wr_id;
518 		wc.status = err;
519 		qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
520 	}
521 	wc.status = IB_WC_WR_FLUSH_ERR;
522 
523 	if (qp->r_rq.wq) {
524 		struct qib_rwq *wq;
525 		u32 head;
526 		u32 tail;
527 
528 		spin_lock(&qp->r_rq.lock);
529 
530 		/* sanity check pointers before trusting them */
531 		wq = qp->r_rq.wq;
532 		head = wq->head;
533 		if (head >= qp->r_rq.size)
534 			head = 0;
535 		tail = wq->tail;
536 		if (tail >= qp->r_rq.size)
537 			tail = 0;
538 		while (tail != head) {
539 			wc.wr_id = get_rwqe_ptr(&qp->r_rq, tail)->wr_id;
540 			if (++tail >= qp->r_rq.size)
541 				tail = 0;
542 			qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
543 		}
544 		wq->tail = tail;
545 
546 		spin_unlock(&qp->r_rq.lock);
547 	} else if (qp->ibqp.event_handler)
548 		ret = 1;
549 
550 bail:
551 	return ret;
552 }
553 
554 /**
555  * qib_modify_qp - modify the attributes of a queue pair
556  * @ibqp: the queue pair who's attributes we're modifying
557  * @attr: the new attributes
558  * @attr_mask: the mask of attributes to modify
559  * @udata: user data for libibverbs.so
560  *
561  * Returns 0 on success, otherwise returns an errno.
562  */
563 int qib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
564 		  int attr_mask, struct ib_udata *udata)
565 {
566 	struct qib_ibdev *dev = to_idev(ibqp->device);
567 	struct qib_qp *qp = to_iqp(ibqp);
568 	enum ib_qp_state cur_state, new_state;
569 	struct ib_event ev;
570 	int lastwqe = 0;
571 	int mig = 0;
572 	int ret;
573 	u32 pmtu = 0; /* for gcc warning only */
574 
575 	spin_lock_irq(&qp->r_lock);
576 	spin_lock(&qp->s_lock);
577 
578 	cur_state = attr_mask & IB_QP_CUR_STATE ?
579 		attr->cur_qp_state : qp->state;
580 	new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;
581 
582 	if (!ib_modify_qp_is_ok(cur_state, new_state, ibqp->qp_type,
583 				attr_mask))
584 		goto inval;
585 
586 	if (attr_mask & IB_QP_AV) {
587 		if (attr->ah_attr.dlid >= QIB_MULTICAST_LID_BASE)
588 			goto inval;
589 		if (qib_check_ah(qp->ibqp.device, &attr->ah_attr))
590 			goto inval;
591 	}
592 
593 	if (attr_mask & IB_QP_ALT_PATH) {
594 		if (attr->alt_ah_attr.dlid >= QIB_MULTICAST_LID_BASE)
595 			goto inval;
596 		if (qib_check_ah(qp->ibqp.device, &attr->alt_ah_attr))
597 			goto inval;
598 		if (attr->alt_pkey_index >= qib_get_npkeys(dd_from_dev(dev)))
599 			goto inval;
600 	}
601 
602 	if (attr_mask & IB_QP_PKEY_INDEX)
603 		if (attr->pkey_index >= qib_get_npkeys(dd_from_dev(dev)))
604 			goto inval;
605 
606 	if (attr_mask & IB_QP_MIN_RNR_TIMER)
607 		if (attr->min_rnr_timer > 31)
608 			goto inval;
609 
610 	if (attr_mask & IB_QP_PORT)
611 		if (qp->ibqp.qp_type == IB_QPT_SMI ||
612 		    qp->ibqp.qp_type == IB_QPT_GSI ||
613 		    attr->port_num == 0 ||
614 		    attr->port_num > ibqp->device->phys_port_cnt)
615 			goto inval;
616 
617 	if (attr_mask & IB_QP_DEST_QPN)
618 		if (attr->dest_qp_num > QIB_QPN_MASK)
619 			goto inval;
620 
621 	if (attr_mask & IB_QP_RETRY_CNT)
622 		if (attr->retry_cnt > 7)
623 			goto inval;
624 
625 	if (attr_mask & IB_QP_RNR_RETRY)
626 		if (attr->rnr_retry > 7)
627 			goto inval;
628 
629 	/*
630 	 * Don't allow invalid path_mtu values.  OK to set greater
631 	 * than the active mtu (or even the max_cap, if we have tuned
632 	 * that to a small mtu.  We'll set qp->path_mtu
633 	 * to the lesser of requested attribute mtu and active,
634 	 * for packetizing messages.
635 	 * Note that the QP port has to be set in INIT and MTU in RTR.
636 	 */
637 	if (attr_mask & IB_QP_PATH_MTU) {
638 		struct qib_devdata *dd = dd_from_dev(dev);
639 		int mtu, pidx = qp->port_num - 1;
640 
641 		mtu = ib_mtu_enum_to_int(attr->path_mtu);
642 		if (mtu == -1)
643 			goto inval;
644 		if (mtu > dd->pport[pidx].ibmtu) {
645 			switch (dd->pport[pidx].ibmtu) {
646 			case 4096:
647 				pmtu = IB_MTU_4096;
648 				break;
649 			case 2048:
650 				pmtu = IB_MTU_2048;
651 				break;
652 			case 1024:
653 				pmtu = IB_MTU_1024;
654 				break;
655 			case 512:
656 				pmtu = IB_MTU_512;
657 				break;
658 			case 256:
659 				pmtu = IB_MTU_256;
660 				break;
661 			default:
662 				pmtu = IB_MTU_2048;
663 			}
664 		} else
665 			pmtu = attr->path_mtu;
666 	}
667 
668 	if (attr_mask & IB_QP_PATH_MIG_STATE) {
669 		if (attr->path_mig_state == IB_MIG_REARM) {
670 			if (qp->s_mig_state == IB_MIG_ARMED)
671 				goto inval;
672 			if (new_state != IB_QPS_RTS)
673 				goto inval;
674 		} else if (attr->path_mig_state == IB_MIG_MIGRATED) {
675 			if (qp->s_mig_state == IB_MIG_REARM)
676 				goto inval;
677 			if (new_state != IB_QPS_RTS && new_state != IB_QPS_SQD)
678 				goto inval;
679 			if (qp->s_mig_state == IB_MIG_ARMED)
680 				mig = 1;
681 		} else
682 			goto inval;
683 	}
684 
685 	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
686 		if (attr->max_dest_rd_atomic > QIB_MAX_RDMA_ATOMIC)
687 			goto inval;
688 
689 	switch (new_state) {
690 	case IB_QPS_RESET:
691 		if (qp->state != IB_QPS_RESET) {
692 			qp->state = IB_QPS_RESET;
693 			spin_lock(&dev->pending_lock);
694 			if (!list_empty(&qp->iowait))
695 				list_del_init(&qp->iowait);
696 			spin_unlock(&dev->pending_lock);
697 			qp->s_flags &= ~(QIB_S_TIMER | QIB_S_ANY_WAIT);
698 			spin_unlock(&qp->s_lock);
699 			spin_unlock_irq(&qp->r_lock);
700 			/* Stop the sending work queue and retry timer */
701 			cancel_work_sync(&qp->s_work);
702 			del_timer_sync(&qp->s_timer);
703 			wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
704 			if (qp->s_tx) {
705 				qib_put_txreq(qp->s_tx);
706 				qp->s_tx = NULL;
707 			}
708 			remove_qp(dev, qp);
709 			wait_event(qp->wait, !atomic_read(&qp->refcount));
710 			spin_lock_irq(&qp->r_lock);
711 			spin_lock(&qp->s_lock);
712 			clear_mr_refs(qp, 1);
713 			qib_reset_qp(qp, ibqp->qp_type);
714 		}
715 		break;
716 
717 	case IB_QPS_RTR:
718 		/* Allow event to retrigger if QP set to RTR more than once */
719 		qp->r_flags &= ~QIB_R_COMM_EST;
720 		qp->state = new_state;
721 		break;
722 
723 	case IB_QPS_SQD:
724 		qp->s_draining = qp->s_last != qp->s_cur;
725 		qp->state = new_state;
726 		break;
727 
728 	case IB_QPS_SQE:
729 		if (qp->ibqp.qp_type == IB_QPT_RC)
730 			goto inval;
731 		qp->state = new_state;
732 		break;
733 
734 	case IB_QPS_ERR:
735 		lastwqe = qib_error_qp(qp, IB_WC_WR_FLUSH_ERR);
736 		break;
737 
738 	default:
739 		qp->state = new_state;
740 		break;
741 	}
742 
743 	if (attr_mask & IB_QP_PKEY_INDEX)
744 		qp->s_pkey_index = attr->pkey_index;
745 
746 	if (attr_mask & IB_QP_PORT)
747 		qp->port_num = attr->port_num;
748 
749 	if (attr_mask & IB_QP_DEST_QPN)
750 		qp->remote_qpn = attr->dest_qp_num;
751 
752 	if (attr_mask & IB_QP_SQ_PSN) {
753 		qp->s_next_psn = attr->sq_psn & QIB_PSN_MASK;
754 		qp->s_psn = qp->s_next_psn;
755 		qp->s_sending_psn = qp->s_next_psn;
756 		qp->s_last_psn = qp->s_next_psn - 1;
757 		qp->s_sending_hpsn = qp->s_last_psn;
758 	}
759 
760 	if (attr_mask & IB_QP_RQ_PSN)
761 		qp->r_psn = attr->rq_psn & QIB_PSN_MASK;
762 
763 	if (attr_mask & IB_QP_ACCESS_FLAGS)
764 		qp->qp_access_flags = attr->qp_access_flags;
765 
766 	if (attr_mask & IB_QP_AV) {
767 		qp->remote_ah_attr = attr->ah_attr;
768 		qp->s_srate = attr->ah_attr.static_rate;
769 	}
770 
771 	if (attr_mask & IB_QP_ALT_PATH) {
772 		qp->alt_ah_attr = attr->alt_ah_attr;
773 		qp->s_alt_pkey_index = attr->alt_pkey_index;
774 	}
775 
776 	if (attr_mask & IB_QP_PATH_MIG_STATE) {
777 		qp->s_mig_state = attr->path_mig_state;
778 		if (mig) {
779 			qp->remote_ah_attr = qp->alt_ah_attr;
780 			qp->port_num = qp->alt_ah_attr.port_num;
781 			qp->s_pkey_index = qp->s_alt_pkey_index;
782 		}
783 	}
784 
785 	if (attr_mask & IB_QP_PATH_MTU) {
786 		qp->path_mtu = pmtu;
787 		qp->pmtu = ib_mtu_enum_to_int(pmtu);
788 	}
789 
790 	if (attr_mask & IB_QP_RETRY_CNT) {
791 		qp->s_retry_cnt = attr->retry_cnt;
792 		qp->s_retry = attr->retry_cnt;
793 	}
794 
795 	if (attr_mask & IB_QP_RNR_RETRY) {
796 		qp->s_rnr_retry_cnt = attr->rnr_retry;
797 		qp->s_rnr_retry = attr->rnr_retry;
798 	}
799 
800 	if (attr_mask & IB_QP_MIN_RNR_TIMER)
801 		qp->r_min_rnr_timer = attr->min_rnr_timer;
802 
803 	if (attr_mask & IB_QP_TIMEOUT) {
804 		qp->timeout = attr->timeout;
805 		qp->timeout_jiffies =
806 			usecs_to_jiffies((4096UL * (1UL << qp->timeout)) /
807 				1000UL);
808 	}
809 
810 	if (attr_mask & IB_QP_QKEY)
811 		qp->qkey = attr->qkey;
812 
813 	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
814 		qp->r_max_rd_atomic = attr->max_dest_rd_atomic;
815 
816 	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC)
817 		qp->s_max_rd_atomic = attr->max_rd_atomic;
818 
819 	spin_unlock(&qp->s_lock);
820 	spin_unlock_irq(&qp->r_lock);
821 
822 	if (cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT)
823 		insert_qp(dev, qp);
824 
825 	if (lastwqe) {
826 		ev.device = qp->ibqp.device;
827 		ev.element.qp = &qp->ibqp;
828 		ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
829 		qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
830 	}
831 	if (mig) {
832 		ev.device = qp->ibqp.device;
833 		ev.element.qp = &qp->ibqp;
834 		ev.event = IB_EVENT_PATH_MIG;
835 		qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
836 	}
837 	ret = 0;
838 	goto bail;
839 
840 inval:
841 	spin_unlock(&qp->s_lock);
842 	spin_unlock_irq(&qp->r_lock);
843 	ret = -EINVAL;
844 
845 bail:
846 	return ret;
847 }
848 
849 int qib_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
850 		 int attr_mask, struct ib_qp_init_attr *init_attr)
851 {
852 	struct qib_qp *qp = to_iqp(ibqp);
853 
854 	attr->qp_state = qp->state;
855 	attr->cur_qp_state = attr->qp_state;
856 	attr->path_mtu = qp->path_mtu;
857 	attr->path_mig_state = qp->s_mig_state;
858 	attr->qkey = qp->qkey;
859 	attr->rq_psn = qp->r_psn & QIB_PSN_MASK;
860 	attr->sq_psn = qp->s_next_psn & QIB_PSN_MASK;
861 	attr->dest_qp_num = qp->remote_qpn;
862 	attr->qp_access_flags = qp->qp_access_flags;
863 	attr->cap.max_send_wr = qp->s_size - 1;
864 	attr->cap.max_recv_wr = qp->ibqp.srq ? 0 : qp->r_rq.size - 1;
865 	attr->cap.max_send_sge = qp->s_max_sge;
866 	attr->cap.max_recv_sge = qp->r_rq.max_sge;
867 	attr->cap.max_inline_data = 0;
868 	attr->ah_attr = qp->remote_ah_attr;
869 	attr->alt_ah_attr = qp->alt_ah_attr;
870 	attr->pkey_index = qp->s_pkey_index;
871 	attr->alt_pkey_index = qp->s_alt_pkey_index;
872 	attr->en_sqd_async_notify = 0;
873 	attr->sq_draining = qp->s_draining;
874 	attr->max_rd_atomic = qp->s_max_rd_atomic;
875 	attr->max_dest_rd_atomic = qp->r_max_rd_atomic;
876 	attr->min_rnr_timer = qp->r_min_rnr_timer;
877 	attr->port_num = qp->port_num;
878 	attr->timeout = qp->timeout;
879 	attr->retry_cnt = qp->s_retry_cnt;
880 	attr->rnr_retry = qp->s_rnr_retry_cnt;
881 	attr->alt_port_num = qp->alt_ah_attr.port_num;
882 	attr->alt_timeout = qp->alt_timeout;
883 
884 	init_attr->event_handler = qp->ibqp.event_handler;
885 	init_attr->qp_context = qp->ibqp.qp_context;
886 	init_attr->send_cq = qp->ibqp.send_cq;
887 	init_attr->recv_cq = qp->ibqp.recv_cq;
888 	init_attr->srq = qp->ibqp.srq;
889 	init_attr->cap = attr->cap;
890 	if (qp->s_flags & QIB_S_SIGNAL_REQ_WR)
891 		init_attr->sq_sig_type = IB_SIGNAL_REQ_WR;
892 	else
893 		init_attr->sq_sig_type = IB_SIGNAL_ALL_WR;
894 	init_attr->qp_type = qp->ibqp.qp_type;
895 	init_attr->port_num = qp->port_num;
896 	return 0;
897 }
898 
899 /**
900  * qib_compute_aeth - compute the AETH (syndrome + MSN)
901  * @qp: the queue pair to compute the AETH for
902  *
903  * Returns the AETH.
904  */
905 __be32 qib_compute_aeth(struct qib_qp *qp)
906 {
907 	u32 aeth = qp->r_msn & QIB_MSN_MASK;
908 
909 	if (qp->ibqp.srq) {
910 		/*
911 		 * Shared receive queues don't generate credits.
912 		 * Set the credit field to the invalid value.
913 		 */
914 		aeth |= QIB_AETH_CREDIT_INVAL << QIB_AETH_CREDIT_SHIFT;
915 	} else {
916 		u32 min, max, x;
917 		u32 credits;
918 		struct qib_rwq *wq = qp->r_rq.wq;
919 		u32 head;
920 		u32 tail;
921 
922 		/* sanity check pointers before trusting them */
923 		head = wq->head;
924 		if (head >= qp->r_rq.size)
925 			head = 0;
926 		tail = wq->tail;
927 		if (tail >= qp->r_rq.size)
928 			tail = 0;
929 		/*
930 		 * Compute the number of credits available (RWQEs).
931 		 * XXX Not holding the r_rq.lock here so there is a small
932 		 * chance that the pair of reads are not atomic.
933 		 */
934 		credits = head - tail;
935 		if ((int)credits < 0)
936 			credits += qp->r_rq.size;
937 		/*
938 		 * Binary search the credit table to find the code to
939 		 * use.
940 		 */
941 		min = 0;
942 		max = 31;
943 		for (;;) {
944 			x = (min + max) / 2;
945 			if (credit_table[x] == credits)
946 				break;
947 			if (credit_table[x] > credits)
948 				max = x;
949 			else if (min == x)
950 				break;
951 			else
952 				min = x;
953 		}
954 		aeth |= x << QIB_AETH_CREDIT_SHIFT;
955 	}
956 	return cpu_to_be32(aeth);
957 }
958 
959 /**
960  * qib_create_qp - create a queue pair for a device
961  * @ibpd: the protection domain who's device we create the queue pair for
962  * @init_attr: the attributes of the queue pair
963  * @udata: user data for libibverbs.so
964  *
965  * Returns the queue pair on success, otherwise returns an errno.
966  *
967  * Called by the ib_create_qp() core verbs function.
968  */
969 struct ib_qp *qib_create_qp(struct ib_pd *ibpd,
970 			    struct ib_qp_init_attr *init_attr,
971 			    struct ib_udata *udata)
972 {
973 	struct qib_qp *qp;
974 	int err;
975 	struct qib_swqe *swq = NULL;
976 	struct qib_ibdev *dev;
977 	struct qib_devdata *dd;
978 	size_t sz;
979 	size_t sg_list_sz;
980 	struct ib_qp *ret;
981 
982 	if (init_attr->cap.max_send_sge > ib_qib_max_sges ||
983 	    init_attr->cap.max_send_wr > ib_qib_max_qp_wrs) {
984 		ret = ERR_PTR(-EINVAL);
985 		goto bail;
986 	}
987 
988 	/* Check receive queue parameters if no SRQ is specified. */
989 	if (!init_attr->srq) {
990 		if (init_attr->cap.max_recv_sge > ib_qib_max_sges ||
991 		    init_attr->cap.max_recv_wr > ib_qib_max_qp_wrs) {
992 			ret = ERR_PTR(-EINVAL);
993 			goto bail;
994 		}
995 		if (init_attr->cap.max_send_sge +
996 		    init_attr->cap.max_send_wr +
997 		    init_attr->cap.max_recv_sge +
998 		    init_attr->cap.max_recv_wr == 0) {
999 			ret = ERR_PTR(-EINVAL);
1000 			goto bail;
1001 		}
1002 	}
1003 
1004 	switch (init_attr->qp_type) {
1005 	case IB_QPT_SMI:
1006 	case IB_QPT_GSI:
1007 		if (init_attr->port_num == 0 ||
1008 		    init_attr->port_num > ibpd->device->phys_port_cnt) {
1009 			ret = ERR_PTR(-EINVAL);
1010 			goto bail;
1011 		}
1012 	case IB_QPT_UC:
1013 	case IB_QPT_RC:
1014 	case IB_QPT_UD:
1015 		sz = sizeof(struct qib_sge) *
1016 			init_attr->cap.max_send_sge +
1017 			sizeof(struct qib_swqe);
1018 		swq = vmalloc((init_attr->cap.max_send_wr + 1) * sz);
1019 		if (swq == NULL) {
1020 			ret = ERR_PTR(-ENOMEM);
1021 			goto bail;
1022 		}
1023 		sz = sizeof(*qp);
1024 		sg_list_sz = 0;
1025 		if (init_attr->srq) {
1026 			struct qib_srq *srq = to_isrq(init_attr->srq);
1027 
1028 			if (srq->rq.max_sge > 1)
1029 				sg_list_sz = sizeof(*qp->r_sg_list) *
1030 					(srq->rq.max_sge - 1);
1031 		} else if (init_attr->cap.max_recv_sge > 1)
1032 			sg_list_sz = sizeof(*qp->r_sg_list) *
1033 				(init_attr->cap.max_recv_sge - 1);
1034 		qp = kzalloc(sz + sg_list_sz, GFP_KERNEL);
1035 		if (!qp) {
1036 			ret = ERR_PTR(-ENOMEM);
1037 			goto bail_swq;
1038 		}
1039 		RCU_INIT_POINTER(qp->next, NULL);
1040 		qp->s_hdr = kzalloc(sizeof(*qp->s_hdr), GFP_KERNEL);
1041 		if (!qp->s_hdr) {
1042 			ret = ERR_PTR(-ENOMEM);
1043 			goto bail_qp;
1044 		}
1045 		qp->timeout_jiffies =
1046 			usecs_to_jiffies((4096UL * (1UL << qp->timeout)) /
1047 				1000UL);
1048 		if (init_attr->srq)
1049 			sz = 0;
1050 		else {
1051 			qp->r_rq.size = init_attr->cap.max_recv_wr + 1;
1052 			qp->r_rq.max_sge = init_attr->cap.max_recv_sge;
1053 			sz = (sizeof(struct ib_sge) * qp->r_rq.max_sge) +
1054 				sizeof(struct qib_rwqe);
1055 			qp->r_rq.wq = vmalloc_user(sizeof(struct qib_rwq) +
1056 						   qp->r_rq.size * sz);
1057 			if (!qp->r_rq.wq) {
1058 				ret = ERR_PTR(-ENOMEM);
1059 				goto bail_qp;
1060 			}
1061 		}
1062 
1063 		/*
1064 		 * ib_create_qp() will initialize qp->ibqp
1065 		 * except for qp->ibqp.qp_num.
1066 		 */
1067 		spin_lock_init(&qp->r_lock);
1068 		spin_lock_init(&qp->s_lock);
1069 		spin_lock_init(&qp->r_rq.lock);
1070 		atomic_set(&qp->refcount, 0);
1071 		init_waitqueue_head(&qp->wait);
1072 		init_waitqueue_head(&qp->wait_dma);
1073 		init_timer(&qp->s_timer);
1074 		qp->s_timer.data = (unsigned long)qp;
1075 		INIT_WORK(&qp->s_work, qib_do_send);
1076 		INIT_LIST_HEAD(&qp->iowait);
1077 		INIT_LIST_HEAD(&qp->rspwait);
1078 		qp->state = IB_QPS_RESET;
1079 		qp->s_wq = swq;
1080 		qp->s_size = init_attr->cap.max_send_wr + 1;
1081 		qp->s_max_sge = init_attr->cap.max_send_sge;
1082 		if (init_attr->sq_sig_type == IB_SIGNAL_REQ_WR)
1083 			qp->s_flags = QIB_S_SIGNAL_REQ_WR;
1084 		dev = to_idev(ibpd->device);
1085 		dd = dd_from_dev(dev);
1086 		err = alloc_qpn(dd, &dev->qpn_table, init_attr->qp_type,
1087 				init_attr->port_num);
1088 		if (err < 0) {
1089 			ret = ERR_PTR(err);
1090 			vfree(qp->r_rq.wq);
1091 			goto bail_qp;
1092 		}
1093 		qp->ibqp.qp_num = err;
1094 		qp->port_num = init_attr->port_num;
1095 		qib_reset_qp(qp, init_attr->qp_type);
1096 		break;
1097 
1098 	default:
1099 		/* Don't support raw QPs */
1100 		ret = ERR_PTR(-ENOSYS);
1101 		goto bail;
1102 	}
1103 
1104 	init_attr->cap.max_inline_data = 0;
1105 
1106 	/*
1107 	 * Return the address of the RWQ as the offset to mmap.
1108 	 * See qib_mmap() for details.
1109 	 */
1110 	if (udata && udata->outlen >= sizeof(__u64)) {
1111 		if (!qp->r_rq.wq) {
1112 			__u64 offset = 0;
1113 
1114 			err = ib_copy_to_udata(udata, &offset,
1115 					       sizeof(offset));
1116 			if (err) {
1117 				ret = ERR_PTR(err);
1118 				goto bail_ip;
1119 			}
1120 		} else {
1121 			u32 s = sizeof(struct qib_rwq) + qp->r_rq.size * sz;
1122 
1123 			qp->ip = qib_create_mmap_info(dev, s,
1124 						      ibpd->uobject->context,
1125 						      qp->r_rq.wq);
1126 			if (!qp->ip) {
1127 				ret = ERR_PTR(-ENOMEM);
1128 				goto bail_ip;
1129 			}
1130 
1131 			err = ib_copy_to_udata(udata, &(qp->ip->offset),
1132 					       sizeof(qp->ip->offset));
1133 			if (err) {
1134 				ret = ERR_PTR(err);
1135 				goto bail_ip;
1136 			}
1137 		}
1138 	}
1139 
1140 	spin_lock(&dev->n_qps_lock);
1141 	if (dev->n_qps_allocated == ib_qib_max_qps) {
1142 		spin_unlock(&dev->n_qps_lock);
1143 		ret = ERR_PTR(-ENOMEM);
1144 		goto bail_ip;
1145 	}
1146 
1147 	dev->n_qps_allocated++;
1148 	spin_unlock(&dev->n_qps_lock);
1149 
1150 	if (qp->ip) {
1151 		spin_lock_irq(&dev->pending_lock);
1152 		list_add(&qp->ip->pending_mmaps, &dev->pending_mmaps);
1153 		spin_unlock_irq(&dev->pending_lock);
1154 	}
1155 
1156 	ret = &qp->ibqp;
1157 	goto bail;
1158 
1159 bail_ip:
1160 	if (qp->ip)
1161 		kref_put(&qp->ip->ref, qib_release_mmap_info);
1162 	else
1163 		vfree(qp->r_rq.wq);
1164 	free_qpn(&dev->qpn_table, qp->ibqp.qp_num);
1165 bail_qp:
1166 	kfree(qp->s_hdr);
1167 	kfree(qp);
1168 bail_swq:
1169 	vfree(swq);
1170 bail:
1171 	return ret;
1172 }
1173 
1174 /**
1175  * qib_destroy_qp - destroy a queue pair
1176  * @ibqp: the queue pair to destroy
1177  *
1178  * Returns 0 on success.
1179  *
1180  * Note that this can be called while the QP is actively sending or
1181  * receiving!
1182  */
1183 int qib_destroy_qp(struct ib_qp *ibqp)
1184 {
1185 	struct qib_qp *qp = to_iqp(ibqp);
1186 	struct qib_ibdev *dev = to_idev(ibqp->device);
1187 
1188 	/* Make sure HW and driver activity is stopped. */
1189 	spin_lock_irq(&qp->s_lock);
1190 	if (qp->state != IB_QPS_RESET) {
1191 		qp->state = IB_QPS_RESET;
1192 		spin_lock(&dev->pending_lock);
1193 		if (!list_empty(&qp->iowait))
1194 			list_del_init(&qp->iowait);
1195 		spin_unlock(&dev->pending_lock);
1196 		qp->s_flags &= ~(QIB_S_TIMER | QIB_S_ANY_WAIT);
1197 		spin_unlock_irq(&qp->s_lock);
1198 		cancel_work_sync(&qp->s_work);
1199 		del_timer_sync(&qp->s_timer);
1200 		wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
1201 		if (qp->s_tx) {
1202 			qib_put_txreq(qp->s_tx);
1203 			qp->s_tx = NULL;
1204 		}
1205 		remove_qp(dev, qp);
1206 		wait_event(qp->wait, !atomic_read(&qp->refcount));
1207 		clear_mr_refs(qp, 1);
1208 	} else
1209 		spin_unlock_irq(&qp->s_lock);
1210 
1211 	/* all user's cleaned up, mark it available */
1212 	free_qpn(&dev->qpn_table, qp->ibqp.qp_num);
1213 	spin_lock(&dev->n_qps_lock);
1214 	dev->n_qps_allocated--;
1215 	spin_unlock(&dev->n_qps_lock);
1216 
1217 	if (qp->ip)
1218 		kref_put(&qp->ip->ref, qib_release_mmap_info);
1219 	else
1220 		vfree(qp->r_rq.wq);
1221 	vfree(qp->s_wq);
1222 	kfree(qp->s_hdr);
1223 	kfree(qp);
1224 	return 0;
1225 }
1226 
1227 /**
1228  * qib_init_qpn_table - initialize the QP number table for a device
1229  * @qpt: the QPN table
1230  */
1231 void qib_init_qpn_table(struct qib_devdata *dd, struct qib_qpn_table *qpt)
1232 {
1233 	spin_lock_init(&qpt->lock);
1234 	qpt->last = 1;          /* start with QPN 2 */
1235 	qpt->nmaps = 1;
1236 	qpt->mask = dd->qpn_mask;
1237 }
1238 
1239 /**
1240  * qib_free_qpn_table - free the QP number table for a device
1241  * @qpt: the QPN table
1242  */
1243 void qib_free_qpn_table(struct qib_qpn_table *qpt)
1244 {
1245 	int i;
1246 
1247 	for (i = 0; i < ARRAY_SIZE(qpt->map); i++)
1248 		if (qpt->map[i].page)
1249 			free_page((unsigned long) qpt->map[i].page);
1250 }
1251 
1252 /**
1253  * qib_get_credit - flush the send work queue of a QP
1254  * @qp: the qp who's send work queue to flush
1255  * @aeth: the Acknowledge Extended Transport Header
1256  *
1257  * The QP s_lock should be held.
1258  */
1259 void qib_get_credit(struct qib_qp *qp, u32 aeth)
1260 {
1261 	u32 credit = (aeth >> QIB_AETH_CREDIT_SHIFT) & QIB_AETH_CREDIT_MASK;
1262 
1263 	/*
1264 	 * If the credit is invalid, we can send
1265 	 * as many packets as we like.  Otherwise, we have to
1266 	 * honor the credit field.
1267 	 */
1268 	if (credit == QIB_AETH_CREDIT_INVAL) {
1269 		if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) {
1270 			qp->s_flags |= QIB_S_UNLIMITED_CREDIT;
1271 			if (qp->s_flags & QIB_S_WAIT_SSN_CREDIT) {
1272 				qp->s_flags &= ~QIB_S_WAIT_SSN_CREDIT;
1273 				qib_schedule_send(qp);
1274 			}
1275 		}
1276 	} else if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) {
1277 		/* Compute new LSN (i.e., MSN + credit) */
1278 		credit = (aeth + credit_table[credit]) & QIB_MSN_MASK;
1279 		if (qib_cmp24(credit, qp->s_lsn) > 0) {
1280 			qp->s_lsn = credit;
1281 			if (qp->s_flags & QIB_S_WAIT_SSN_CREDIT) {
1282 				qp->s_flags &= ~QIB_S_WAIT_SSN_CREDIT;
1283 				qib_schedule_send(qp);
1284 			}
1285 		}
1286 	}
1287 }
1288