1 /*
2  * Copyright (c) 2006, 2007, 2008, 2009, 2010 QLogic Corporation.
3  * 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 
38 #include "qib.h"
39 
40 #define BITS_PER_PAGE           (PAGE_SIZE*BITS_PER_BYTE)
41 #define BITS_PER_PAGE_MASK      (BITS_PER_PAGE-1)
42 
mk_qpn(struct qib_qpn_table * qpt,struct qpn_map * map,unsigned off)43 static inline unsigned mk_qpn(struct qib_qpn_table *qpt,
44 			      struct qpn_map *map, unsigned off)
45 {
46 	return (map - qpt->map) * BITS_PER_PAGE + off;
47 }
48 
find_next_offset(struct qib_qpn_table * qpt,struct qpn_map * map,unsigned off,unsigned n)49 static inline unsigned find_next_offset(struct qib_qpn_table *qpt,
50 					struct qpn_map *map, unsigned off,
51 					unsigned n)
52 {
53 	if (qpt->mask) {
54 		off++;
55 		if (((off & qpt->mask) >> 1) >= n)
56 			off = (off | qpt->mask) + 2;
57 	} else
58 		off = find_next_zero_bit(map->page, BITS_PER_PAGE, off);
59 	return off;
60 }
61 
62 /*
63  * Convert the AETH credit code into the number of credits.
64  */
65 static u32 credit_table[31] = {
66 	0,                      /* 0 */
67 	1,                      /* 1 */
68 	2,                      /* 2 */
69 	3,                      /* 3 */
70 	4,                      /* 4 */
71 	6,                      /* 5 */
72 	8,                      /* 6 */
73 	12,                     /* 7 */
74 	16,                     /* 8 */
75 	24,                     /* 9 */
76 	32,                     /* A */
77 	48,                     /* B */
78 	64,                     /* C */
79 	96,                     /* D */
80 	128,                    /* E */
81 	192,                    /* F */
82 	256,                    /* 10 */
83 	384,                    /* 11 */
84 	512,                    /* 12 */
85 	768,                    /* 13 */
86 	1024,                   /* 14 */
87 	1536,                   /* 15 */
88 	2048,                   /* 16 */
89 	3072,                   /* 17 */
90 	4096,                   /* 18 */
91 	6144,                   /* 19 */
92 	8192,                   /* 1A */
93 	12288,                  /* 1B */
94 	16384,                  /* 1C */
95 	24576,                  /* 1D */
96 	32768                   /* 1E */
97 };
98 
get_map_page(struct qib_qpn_table * qpt,struct qpn_map * map)99 static void get_map_page(struct qib_qpn_table *qpt, struct qpn_map *map)
100 {
101 	unsigned long page = get_zeroed_page(GFP_KERNEL);
102 
103 	/*
104 	 * Free the page if someone raced with us installing it.
105 	 */
106 
107 	spin_lock(&qpt->lock);
108 	if (map->page)
109 		free_page(page);
110 	else
111 		map->page = (void *)page;
112 	spin_unlock(&qpt->lock);
113 }
114 
115 /*
116  * Allocate the next available QPN or
117  * zero/one for QP type IB_QPT_SMI/IB_QPT_GSI.
118  */
alloc_qpn(struct qib_devdata * dd,struct qib_qpn_table * qpt,enum ib_qp_type type,u8 port)119 static int alloc_qpn(struct qib_devdata *dd, struct qib_qpn_table *qpt,
120 		     enum ib_qp_type type, u8 port)
121 {
122 	u32 i, offset, max_scan, qpn;
123 	struct qpn_map *map;
124 	u32 ret;
125 
126 	if (type == IB_QPT_SMI || type == IB_QPT_GSI) {
127 		unsigned n;
128 
129 		ret = type == IB_QPT_GSI;
130 		n = 1 << (ret + 2 * (port - 1));
131 		spin_lock(&qpt->lock);
132 		if (qpt->flags & n)
133 			ret = -EINVAL;
134 		else
135 			qpt->flags |= n;
136 		spin_unlock(&qpt->lock);
137 		goto bail;
138 	}
139 
140 	qpn = qpt->last + 2;
141 	if (qpn >= QPN_MAX)
142 		qpn = 2;
143 	if (qpt->mask && ((qpn & qpt->mask) >> 1) >= dd->n_krcv_queues)
144 		qpn = (qpn | qpt->mask) + 2;
145 	offset = qpn & BITS_PER_PAGE_MASK;
146 	map = &qpt->map[qpn / BITS_PER_PAGE];
147 	max_scan = qpt->nmaps - !offset;
148 	for (i = 0;;) {
149 		if (unlikely(!map->page)) {
150 			get_map_page(qpt, map);
151 			if (unlikely(!map->page))
152 				break;
153 		}
154 		do {
155 			if (!test_and_set_bit(offset, map->page)) {
156 				qpt->last = qpn;
157 				ret = qpn;
158 				goto bail;
159 			}
160 			offset = find_next_offset(qpt, map, offset,
161 				dd->n_krcv_queues);
162 			qpn = mk_qpn(qpt, map, offset);
163 			/*
164 			 * This test differs from alloc_pidmap().
165 			 * If find_next_offset() does find a zero
166 			 * bit, we don't need to check for QPN
167 			 * wrapping around past our starting QPN.
168 			 * We just need to be sure we don't loop
169 			 * forever.
170 			 */
171 		} while (offset < BITS_PER_PAGE && qpn < QPN_MAX);
172 		/*
173 		 * In order to keep the number of pages allocated to a
174 		 * minimum, we scan the all existing pages before increasing
175 		 * the size of the bitmap table.
176 		 */
177 		if (++i > max_scan) {
178 			if (qpt->nmaps == QPNMAP_ENTRIES)
179 				break;
180 			map = &qpt->map[qpt->nmaps++];
181 			offset = 0;
182 		} else if (map < &qpt->map[qpt->nmaps]) {
183 			++map;
184 			offset = 0;
185 		} else {
186 			map = &qpt->map[0];
187 			offset = 2;
188 		}
189 		qpn = mk_qpn(qpt, map, offset);
190 	}
191 
192 	ret = -ENOMEM;
193 
194 bail:
195 	return ret;
196 }
197 
free_qpn(struct qib_qpn_table * qpt,u32 qpn)198 static void free_qpn(struct qib_qpn_table *qpt, u32 qpn)
199 {
200 	struct qpn_map *map;
201 
202 	map = qpt->map + qpn / BITS_PER_PAGE;
203 	if (map->page)
204 		clear_bit(qpn & BITS_PER_PAGE_MASK, map->page);
205 }
206 
207 /*
208  * Put the QP into the hash table.
209  * The hash table holds a reference to the QP.
210  */
insert_qp(struct qib_ibdev * dev,struct qib_qp * qp)211 static void insert_qp(struct qib_ibdev *dev, struct qib_qp *qp)
212 {
213 	struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
214 	unsigned n = qp->ibqp.qp_num % dev->qp_table_size;
215 	unsigned long flags;
216 
217 	spin_lock_irqsave(&dev->qpt_lock, flags);
218 
219 	if (qp->ibqp.qp_num == 0)
220 		ibp->qp0 = qp;
221 	else if (qp->ibqp.qp_num == 1)
222 		ibp->qp1 = qp;
223 	else {
224 		qp->next = dev->qp_table[n];
225 		dev->qp_table[n] = qp;
226 	}
227 	atomic_inc(&qp->refcount);
228 
229 	spin_unlock_irqrestore(&dev->qpt_lock, flags);
230 }
231 
232 /*
233  * Remove the QP from the table so it can't be found asynchronously by
234  * the receive interrupt routine.
235  */
remove_qp(struct qib_ibdev * dev,struct qib_qp * qp)236 static void remove_qp(struct qib_ibdev *dev, struct qib_qp *qp)
237 {
238 	struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
239 	struct qib_qp *q, **qpp;
240 	unsigned long flags;
241 
242 	qpp = &dev->qp_table[qp->ibqp.qp_num % dev->qp_table_size];
243 
244 	spin_lock_irqsave(&dev->qpt_lock, flags);
245 
246 	if (ibp->qp0 == qp) {
247 		ibp->qp0 = NULL;
248 		atomic_dec(&qp->refcount);
249 	} else if (ibp->qp1 == qp) {
250 		ibp->qp1 = NULL;
251 		atomic_dec(&qp->refcount);
252 	} else
253 		for (; (q = *qpp) != NULL; qpp = &q->next)
254 			if (q == qp) {
255 				*qpp = qp->next;
256 				qp->next = NULL;
257 				atomic_dec(&qp->refcount);
258 				break;
259 			}
260 
261 	spin_unlock_irqrestore(&dev->qpt_lock, flags);
262 }
263 
264 /**
265  * qib_free_all_qps - check for QPs still in use
266  * @qpt: the QP table to empty
267  *
268  * There should not be any QPs still in use.
269  * Free memory for table.
270  */
qib_free_all_qps(struct qib_devdata * dd)271 unsigned qib_free_all_qps(struct qib_devdata *dd)
272 {
273 	struct qib_ibdev *dev = &dd->verbs_dev;
274 	unsigned long flags;
275 	struct qib_qp *qp;
276 	unsigned n, qp_inuse = 0;
277 
278 	for (n = 0; n < dd->num_pports; n++) {
279 		struct qib_ibport *ibp = &dd->pport[n].ibport_data;
280 
281 		if (!qib_mcast_tree_empty(ibp))
282 			qp_inuse++;
283 		if (ibp->qp0)
284 			qp_inuse++;
285 		if (ibp->qp1)
286 			qp_inuse++;
287 	}
288 
289 	spin_lock_irqsave(&dev->qpt_lock, flags);
290 	for (n = 0; n < dev->qp_table_size; n++) {
291 		qp = dev->qp_table[n];
292 		dev->qp_table[n] = NULL;
293 
294 		for (; qp; qp = qp->next)
295 			qp_inuse++;
296 	}
297 	spin_unlock_irqrestore(&dev->qpt_lock, flags);
298 
299 	return qp_inuse;
300 }
301 
302 /**
303  * qib_lookup_qpn - return the QP with the given QPN
304  * @qpt: the QP table
305  * @qpn: the QP number to look up
306  *
307  * The caller is responsible for decrementing the QP reference count
308  * when done.
309  */
qib_lookup_qpn(struct qib_ibport * ibp,u32 qpn)310 struct qib_qp *qib_lookup_qpn(struct qib_ibport *ibp, u32 qpn)
311 {
312 	struct qib_ibdev *dev = &ppd_from_ibp(ibp)->dd->verbs_dev;
313 	unsigned long flags;
314 	struct qib_qp *qp;
315 
316 	spin_lock_irqsave(&dev->qpt_lock, flags);
317 
318 	if (qpn == 0)
319 		qp = ibp->qp0;
320 	else if (qpn == 1)
321 		qp = ibp->qp1;
322 	else
323 		for (qp = dev->qp_table[qpn % dev->qp_table_size]; qp;
324 		     qp = qp->next)
325 			if (qp->ibqp.qp_num == qpn)
326 				break;
327 	if (qp)
328 		atomic_inc(&qp->refcount);
329 
330 	spin_unlock_irqrestore(&dev->qpt_lock, flags);
331 	return qp;
332 }
333 
334 /**
335  * qib_reset_qp - initialize the QP state to the reset state
336  * @qp: the QP to reset
337  * @type: the QP type
338  */
qib_reset_qp(struct qib_qp * qp,enum ib_qp_type type)339 static void qib_reset_qp(struct qib_qp *qp, enum ib_qp_type type)
340 {
341 	qp->remote_qpn = 0;
342 	qp->qkey = 0;
343 	qp->qp_access_flags = 0;
344 	atomic_set(&qp->s_dma_busy, 0);
345 	qp->s_flags &= QIB_S_SIGNAL_REQ_WR;
346 	qp->s_hdrwords = 0;
347 	qp->s_wqe = NULL;
348 	qp->s_draining = 0;
349 	qp->s_next_psn = 0;
350 	qp->s_last_psn = 0;
351 	qp->s_sending_psn = 0;
352 	qp->s_sending_hpsn = 0;
353 	qp->s_psn = 0;
354 	qp->r_psn = 0;
355 	qp->r_msn = 0;
356 	if (type == IB_QPT_RC) {
357 		qp->s_state = IB_OPCODE_RC_SEND_LAST;
358 		qp->r_state = IB_OPCODE_RC_SEND_LAST;
359 	} else {
360 		qp->s_state = IB_OPCODE_UC_SEND_LAST;
361 		qp->r_state = IB_OPCODE_UC_SEND_LAST;
362 	}
363 	qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
364 	qp->r_nak_state = 0;
365 	qp->r_aflags = 0;
366 	qp->r_flags = 0;
367 	qp->s_head = 0;
368 	qp->s_tail = 0;
369 	qp->s_cur = 0;
370 	qp->s_acked = 0;
371 	qp->s_last = 0;
372 	qp->s_ssn = 1;
373 	qp->s_lsn = 0;
374 	qp->s_mig_state = IB_MIG_MIGRATED;
375 	memset(qp->s_ack_queue, 0, sizeof(qp->s_ack_queue));
376 	qp->r_head_ack_queue = 0;
377 	qp->s_tail_ack_queue = 0;
378 	qp->s_num_rd_atomic = 0;
379 	if (qp->r_rq.wq) {
380 		qp->r_rq.wq->head = 0;
381 		qp->r_rq.wq->tail = 0;
382 	}
383 	qp->r_sge.num_sge = 0;
384 }
385 
clear_mr_refs(struct qib_qp * qp,int clr_sends)386 static void clear_mr_refs(struct qib_qp *qp, int clr_sends)
387 {
388 	unsigned n;
389 
390 	if (test_and_clear_bit(QIB_R_REWIND_SGE, &qp->r_aflags))
391 		while (qp->s_rdma_read_sge.num_sge) {
392 			atomic_dec(&qp->s_rdma_read_sge.sge.mr->refcount);
393 			if (--qp->s_rdma_read_sge.num_sge)
394 				qp->s_rdma_read_sge.sge =
395 					*qp->s_rdma_read_sge.sg_list++;
396 		}
397 
398 	while (qp->r_sge.num_sge) {
399 		atomic_dec(&qp->r_sge.sge.mr->refcount);
400 		if (--qp->r_sge.num_sge)
401 			qp->r_sge.sge = *qp->r_sge.sg_list++;
402 	}
403 
404 	if (clr_sends) {
405 		while (qp->s_last != qp->s_head) {
406 			struct qib_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
407 			unsigned i;
408 
409 			for (i = 0; i < wqe->wr.num_sge; i++) {
410 				struct qib_sge *sge = &wqe->sg_list[i];
411 
412 				atomic_dec(&sge->mr->refcount);
413 			}
414 			if (qp->ibqp.qp_type == IB_QPT_UD ||
415 			    qp->ibqp.qp_type == IB_QPT_SMI ||
416 			    qp->ibqp.qp_type == IB_QPT_GSI)
417 				atomic_dec(&to_iah(wqe->wr.wr.ud.ah)->refcount);
418 			if (++qp->s_last >= qp->s_size)
419 				qp->s_last = 0;
420 		}
421 		if (qp->s_rdma_mr) {
422 			atomic_dec(&qp->s_rdma_mr->refcount);
423 			qp->s_rdma_mr = NULL;
424 		}
425 	}
426 
427 	if (qp->ibqp.qp_type != IB_QPT_RC)
428 		return;
429 
430 	for (n = 0; n < ARRAY_SIZE(qp->s_ack_queue); n++) {
431 		struct qib_ack_entry *e = &qp->s_ack_queue[n];
432 
433 		if (e->opcode == IB_OPCODE_RC_RDMA_READ_REQUEST &&
434 		    e->rdma_sge.mr) {
435 			atomic_dec(&e->rdma_sge.mr->refcount);
436 			e->rdma_sge.mr = NULL;
437 		}
438 	}
439 }
440 
441 /**
442  * qib_error_qp - put a QP into the error state
443  * @qp: the QP to put into the error state
444  * @err: the receive completion error to signal if a RWQE is active
445  *
446  * Flushes both send and receive work queues.
447  * Returns true if last WQE event should be generated.
448  * The QP r_lock and s_lock should be held and interrupts disabled.
449  * If we are already in error state, just return.
450  */
qib_error_qp(struct qib_qp * qp,enum ib_wc_status err)451 int qib_error_qp(struct qib_qp *qp, enum ib_wc_status err)
452 {
453 	struct qib_ibdev *dev = to_idev(qp->ibqp.device);
454 	struct ib_wc wc;
455 	int ret = 0;
456 
457 	if (qp->state == IB_QPS_ERR || qp->state == IB_QPS_RESET)
458 		goto bail;
459 
460 	qp->state = IB_QPS_ERR;
461 
462 	if (qp->s_flags & (QIB_S_TIMER | QIB_S_WAIT_RNR)) {
463 		qp->s_flags &= ~(QIB_S_TIMER | QIB_S_WAIT_RNR);
464 		del_timer(&qp->s_timer);
465 	}
466 
467 	if (qp->s_flags & QIB_S_ANY_WAIT_SEND)
468 		qp->s_flags &= ~QIB_S_ANY_WAIT_SEND;
469 
470 	spin_lock(&dev->pending_lock);
471 	if (!list_empty(&qp->iowait) && !(qp->s_flags & QIB_S_BUSY)) {
472 		qp->s_flags &= ~QIB_S_ANY_WAIT_IO;
473 		list_del_init(&qp->iowait);
474 	}
475 	spin_unlock(&dev->pending_lock);
476 
477 	if (!(qp->s_flags & QIB_S_BUSY)) {
478 		qp->s_hdrwords = 0;
479 		if (qp->s_rdma_mr) {
480 			atomic_dec(&qp->s_rdma_mr->refcount);
481 			qp->s_rdma_mr = NULL;
482 		}
483 		if (qp->s_tx) {
484 			qib_put_txreq(qp->s_tx);
485 			qp->s_tx = NULL;
486 		}
487 	}
488 
489 	/* Schedule the sending tasklet to drain the send work queue. */
490 	if (qp->s_last != qp->s_head)
491 		qib_schedule_send(qp);
492 
493 	clear_mr_refs(qp, 0);
494 
495 	memset(&wc, 0, sizeof(wc));
496 	wc.qp = &qp->ibqp;
497 	wc.opcode = IB_WC_RECV;
498 
499 	if (test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags)) {
500 		wc.wr_id = qp->r_wr_id;
501 		wc.status = err;
502 		qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
503 	}
504 	wc.status = IB_WC_WR_FLUSH_ERR;
505 
506 	if (qp->r_rq.wq) {
507 		struct qib_rwq *wq;
508 		u32 head;
509 		u32 tail;
510 
511 		spin_lock(&qp->r_rq.lock);
512 
513 		/* sanity check pointers before trusting them */
514 		wq = qp->r_rq.wq;
515 		head = wq->head;
516 		if (head >= qp->r_rq.size)
517 			head = 0;
518 		tail = wq->tail;
519 		if (tail >= qp->r_rq.size)
520 			tail = 0;
521 		while (tail != head) {
522 			wc.wr_id = get_rwqe_ptr(&qp->r_rq, tail)->wr_id;
523 			if (++tail >= qp->r_rq.size)
524 				tail = 0;
525 			qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
526 		}
527 		wq->tail = tail;
528 
529 		spin_unlock(&qp->r_rq.lock);
530 	} else if (qp->ibqp.event_handler)
531 		ret = 1;
532 
533 bail:
534 	return ret;
535 }
536 
537 /**
538  * qib_modify_qp - modify the attributes of a queue pair
539  * @ibqp: the queue pair who's attributes we're modifying
540  * @attr: the new attributes
541  * @attr_mask: the mask of attributes to modify
542  * @udata: user data for libibverbs.so
543  *
544  * Returns 0 on success, otherwise returns an errno.
545  */
qib_modify_qp(struct ib_qp * ibqp,struct ib_qp_attr * attr,int attr_mask,struct ib_udata * udata)546 int qib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
547 		  int attr_mask, struct ib_udata *udata)
548 {
549 	struct qib_ibdev *dev = to_idev(ibqp->device);
550 	struct qib_qp *qp = to_iqp(ibqp);
551 	enum ib_qp_state cur_state, new_state;
552 	struct ib_event ev;
553 	int lastwqe = 0;
554 	int mig = 0;
555 	int ret;
556 	u32 pmtu = 0; /* for gcc warning only */
557 
558 	spin_lock_irq(&qp->r_lock);
559 	spin_lock(&qp->s_lock);
560 
561 	cur_state = attr_mask & IB_QP_CUR_STATE ?
562 		attr->cur_qp_state : qp->state;
563 	new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;
564 
565 	if (!ib_modify_qp_is_ok(cur_state, new_state, ibqp->qp_type,
566 				attr_mask))
567 		goto inval;
568 
569 	if (attr_mask & IB_QP_AV) {
570 		if (attr->ah_attr.dlid >= QIB_MULTICAST_LID_BASE)
571 			goto inval;
572 		if (qib_check_ah(qp->ibqp.device, &attr->ah_attr))
573 			goto inval;
574 	}
575 
576 	if (attr_mask & IB_QP_ALT_PATH) {
577 		if (attr->alt_ah_attr.dlid >= QIB_MULTICAST_LID_BASE)
578 			goto inval;
579 		if (qib_check_ah(qp->ibqp.device, &attr->alt_ah_attr))
580 			goto inval;
581 		if (attr->alt_pkey_index >= qib_get_npkeys(dd_from_dev(dev)))
582 			goto inval;
583 	}
584 
585 	if (attr_mask & IB_QP_PKEY_INDEX)
586 		if (attr->pkey_index >= qib_get_npkeys(dd_from_dev(dev)))
587 			goto inval;
588 
589 	if (attr_mask & IB_QP_MIN_RNR_TIMER)
590 		if (attr->min_rnr_timer > 31)
591 			goto inval;
592 
593 	if (attr_mask & IB_QP_PORT)
594 		if (qp->ibqp.qp_type == IB_QPT_SMI ||
595 		    qp->ibqp.qp_type == IB_QPT_GSI ||
596 		    attr->port_num == 0 ||
597 		    attr->port_num > ibqp->device->phys_port_cnt)
598 			goto inval;
599 
600 	if (attr_mask & IB_QP_DEST_QPN)
601 		if (attr->dest_qp_num > QIB_QPN_MASK)
602 			goto inval;
603 
604 	if (attr_mask & IB_QP_RETRY_CNT)
605 		if (attr->retry_cnt > 7)
606 			goto inval;
607 
608 	if (attr_mask & IB_QP_RNR_RETRY)
609 		if (attr->rnr_retry > 7)
610 			goto inval;
611 
612 	/*
613 	 * Don't allow invalid path_mtu values.  OK to set greater
614 	 * than the active mtu (or even the max_cap, if we have tuned
615 	 * that to a small mtu.  We'll set qp->path_mtu
616 	 * to the lesser of requested attribute mtu and active,
617 	 * for packetizing messages.
618 	 * Note that the QP port has to be set in INIT and MTU in RTR.
619 	 */
620 	if (attr_mask & IB_QP_PATH_MTU) {
621 		struct qib_devdata *dd = dd_from_dev(dev);
622 		int mtu, pidx = qp->port_num - 1;
623 
624 		mtu = ib_mtu_enum_to_int(attr->path_mtu);
625 		if (mtu == -1)
626 			goto inval;
627 		if (mtu > dd->pport[pidx].ibmtu) {
628 			switch (dd->pport[pidx].ibmtu) {
629 			case 4096:
630 				pmtu = IB_MTU_4096;
631 				break;
632 			case 2048:
633 				pmtu = IB_MTU_2048;
634 				break;
635 			case 1024:
636 				pmtu = IB_MTU_1024;
637 				break;
638 			case 512:
639 				pmtu = IB_MTU_512;
640 				break;
641 			case 256:
642 				pmtu = IB_MTU_256;
643 				break;
644 			default:
645 				pmtu = IB_MTU_2048;
646 			}
647 		} else
648 			pmtu = attr->path_mtu;
649 	}
650 
651 	if (attr_mask & IB_QP_PATH_MIG_STATE) {
652 		if (attr->path_mig_state == IB_MIG_REARM) {
653 			if (qp->s_mig_state == IB_MIG_ARMED)
654 				goto inval;
655 			if (new_state != IB_QPS_RTS)
656 				goto inval;
657 		} else if (attr->path_mig_state == IB_MIG_MIGRATED) {
658 			if (qp->s_mig_state == IB_MIG_REARM)
659 				goto inval;
660 			if (new_state != IB_QPS_RTS && new_state != IB_QPS_SQD)
661 				goto inval;
662 			if (qp->s_mig_state == IB_MIG_ARMED)
663 				mig = 1;
664 		} else
665 			goto inval;
666 	}
667 
668 	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
669 		if (attr->max_dest_rd_atomic > QIB_MAX_RDMA_ATOMIC)
670 			goto inval;
671 
672 	switch (new_state) {
673 	case IB_QPS_RESET:
674 		if (qp->state != IB_QPS_RESET) {
675 			qp->state = IB_QPS_RESET;
676 			spin_lock(&dev->pending_lock);
677 			if (!list_empty(&qp->iowait))
678 				list_del_init(&qp->iowait);
679 			spin_unlock(&dev->pending_lock);
680 			qp->s_flags &= ~(QIB_S_TIMER | QIB_S_ANY_WAIT);
681 			spin_unlock(&qp->s_lock);
682 			spin_unlock_irq(&qp->r_lock);
683 			/* Stop the sending work queue and retry timer */
684 			cancel_work_sync(&qp->s_work);
685 			del_timer_sync(&qp->s_timer);
686 			wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
687 			if (qp->s_tx) {
688 				qib_put_txreq(qp->s_tx);
689 				qp->s_tx = NULL;
690 			}
691 			remove_qp(dev, qp);
692 			wait_event(qp->wait, !atomic_read(&qp->refcount));
693 			spin_lock_irq(&qp->r_lock);
694 			spin_lock(&qp->s_lock);
695 			clear_mr_refs(qp, 1);
696 			qib_reset_qp(qp, ibqp->qp_type);
697 		}
698 		break;
699 
700 	case IB_QPS_RTR:
701 		/* Allow event to retrigger if QP set to RTR more than once */
702 		qp->r_flags &= ~QIB_R_COMM_EST;
703 		qp->state = new_state;
704 		break;
705 
706 	case IB_QPS_SQD:
707 		qp->s_draining = qp->s_last != qp->s_cur;
708 		qp->state = new_state;
709 		break;
710 
711 	case IB_QPS_SQE:
712 		if (qp->ibqp.qp_type == IB_QPT_RC)
713 			goto inval;
714 		qp->state = new_state;
715 		break;
716 
717 	case IB_QPS_ERR:
718 		lastwqe = qib_error_qp(qp, IB_WC_WR_FLUSH_ERR);
719 		break;
720 
721 	default:
722 		qp->state = new_state;
723 		break;
724 	}
725 
726 	if (attr_mask & IB_QP_PKEY_INDEX)
727 		qp->s_pkey_index = attr->pkey_index;
728 
729 	if (attr_mask & IB_QP_PORT)
730 		qp->port_num = attr->port_num;
731 
732 	if (attr_mask & IB_QP_DEST_QPN)
733 		qp->remote_qpn = attr->dest_qp_num;
734 
735 	if (attr_mask & IB_QP_SQ_PSN) {
736 		qp->s_next_psn = attr->sq_psn & QIB_PSN_MASK;
737 		qp->s_psn = qp->s_next_psn;
738 		qp->s_sending_psn = qp->s_next_psn;
739 		qp->s_last_psn = qp->s_next_psn - 1;
740 		qp->s_sending_hpsn = qp->s_last_psn;
741 	}
742 
743 	if (attr_mask & IB_QP_RQ_PSN)
744 		qp->r_psn = attr->rq_psn & QIB_PSN_MASK;
745 
746 	if (attr_mask & IB_QP_ACCESS_FLAGS)
747 		qp->qp_access_flags = attr->qp_access_flags;
748 
749 	if (attr_mask & IB_QP_AV) {
750 		qp->remote_ah_attr = attr->ah_attr;
751 		qp->s_srate = attr->ah_attr.static_rate;
752 	}
753 
754 	if (attr_mask & IB_QP_ALT_PATH) {
755 		qp->alt_ah_attr = attr->alt_ah_attr;
756 		qp->s_alt_pkey_index = attr->alt_pkey_index;
757 	}
758 
759 	if (attr_mask & IB_QP_PATH_MIG_STATE) {
760 		qp->s_mig_state = attr->path_mig_state;
761 		if (mig) {
762 			qp->remote_ah_attr = qp->alt_ah_attr;
763 			qp->port_num = qp->alt_ah_attr.port_num;
764 			qp->s_pkey_index = qp->s_alt_pkey_index;
765 		}
766 	}
767 
768 	if (attr_mask & IB_QP_PATH_MTU)
769 		qp->path_mtu = pmtu;
770 
771 	if (attr_mask & IB_QP_RETRY_CNT) {
772 		qp->s_retry_cnt = attr->retry_cnt;
773 		qp->s_retry = attr->retry_cnt;
774 	}
775 
776 	if (attr_mask & IB_QP_RNR_RETRY) {
777 		qp->s_rnr_retry_cnt = attr->rnr_retry;
778 		qp->s_rnr_retry = attr->rnr_retry;
779 	}
780 
781 	if (attr_mask & IB_QP_MIN_RNR_TIMER)
782 		qp->r_min_rnr_timer = attr->min_rnr_timer;
783 
784 	if (attr_mask & IB_QP_TIMEOUT)
785 		qp->timeout = attr->timeout;
786 
787 	if (attr_mask & IB_QP_QKEY)
788 		qp->qkey = attr->qkey;
789 
790 	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
791 		qp->r_max_rd_atomic = attr->max_dest_rd_atomic;
792 
793 	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC)
794 		qp->s_max_rd_atomic = attr->max_rd_atomic;
795 
796 	spin_unlock(&qp->s_lock);
797 	spin_unlock_irq(&qp->r_lock);
798 
799 	if (cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT)
800 		insert_qp(dev, qp);
801 
802 	if (lastwqe) {
803 		ev.device = qp->ibqp.device;
804 		ev.element.qp = &qp->ibqp;
805 		ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
806 		qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
807 	}
808 	if (mig) {
809 		ev.device = qp->ibqp.device;
810 		ev.element.qp = &qp->ibqp;
811 		ev.event = IB_EVENT_PATH_MIG;
812 		qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
813 	}
814 	ret = 0;
815 	goto bail;
816 
817 inval:
818 	spin_unlock(&qp->s_lock);
819 	spin_unlock_irq(&qp->r_lock);
820 	ret = -EINVAL;
821 
822 bail:
823 	return ret;
824 }
825 
qib_query_qp(struct ib_qp * ibqp,struct ib_qp_attr * attr,int attr_mask,struct ib_qp_init_attr * init_attr)826 int qib_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
827 		 int attr_mask, struct ib_qp_init_attr *init_attr)
828 {
829 	struct qib_qp *qp = to_iqp(ibqp);
830 
831 	attr->qp_state = qp->state;
832 	attr->cur_qp_state = attr->qp_state;
833 	attr->path_mtu = qp->path_mtu;
834 	attr->path_mig_state = qp->s_mig_state;
835 	attr->qkey = qp->qkey;
836 	attr->rq_psn = qp->r_psn & QIB_PSN_MASK;
837 	attr->sq_psn = qp->s_next_psn & QIB_PSN_MASK;
838 	attr->dest_qp_num = qp->remote_qpn;
839 	attr->qp_access_flags = qp->qp_access_flags;
840 	attr->cap.max_send_wr = qp->s_size - 1;
841 	attr->cap.max_recv_wr = qp->ibqp.srq ? 0 : qp->r_rq.size - 1;
842 	attr->cap.max_send_sge = qp->s_max_sge;
843 	attr->cap.max_recv_sge = qp->r_rq.max_sge;
844 	attr->cap.max_inline_data = 0;
845 	attr->ah_attr = qp->remote_ah_attr;
846 	attr->alt_ah_attr = qp->alt_ah_attr;
847 	attr->pkey_index = qp->s_pkey_index;
848 	attr->alt_pkey_index = qp->s_alt_pkey_index;
849 	attr->en_sqd_async_notify = 0;
850 	attr->sq_draining = qp->s_draining;
851 	attr->max_rd_atomic = qp->s_max_rd_atomic;
852 	attr->max_dest_rd_atomic = qp->r_max_rd_atomic;
853 	attr->min_rnr_timer = qp->r_min_rnr_timer;
854 	attr->port_num = qp->port_num;
855 	attr->timeout = qp->timeout;
856 	attr->retry_cnt = qp->s_retry_cnt;
857 	attr->rnr_retry = qp->s_rnr_retry_cnt;
858 	attr->alt_port_num = qp->alt_ah_attr.port_num;
859 	attr->alt_timeout = qp->alt_timeout;
860 
861 	init_attr->event_handler = qp->ibqp.event_handler;
862 	init_attr->qp_context = qp->ibqp.qp_context;
863 	init_attr->send_cq = qp->ibqp.send_cq;
864 	init_attr->recv_cq = qp->ibqp.recv_cq;
865 	init_attr->srq = qp->ibqp.srq;
866 	init_attr->cap = attr->cap;
867 	if (qp->s_flags & QIB_S_SIGNAL_REQ_WR)
868 		init_attr->sq_sig_type = IB_SIGNAL_REQ_WR;
869 	else
870 		init_attr->sq_sig_type = IB_SIGNAL_ALL_WR;
871 	init_attr->qp_type = qp->ibqp.qp_type;
872 	init_attr->port_num = qp->port_num;
873 	return 0;
874 }
875 
876 /**
877  * qib_compute_aeth - compute the AETH (syndrome + MSN)
878  * @qp: the queue pair to compute the AETH for
879  *
880  * Returns the AETH.
881  */
qib_compute_aeth(struct qib_qp * qp)882 __be32 qib_compute_aeth(struct qib_qp *qp)
883 {
884 	u32 aeth = qp->r_msn & QIB_MSN_MASK;
885 
886 	if (qp->ibqp.srq) {
887 		/*
888 		 * Shared receive queues don't generate credits.
889 		 * Set the credit field to the invalid value.
890 		 */
891 		aeth |= QIB_AETH_CREDIT_INVAL << QIB_AETH_CREDIT_SHIFT;
892 	} else {
893 		u32 min, max, x;
894 		u32 credits;
895 		struct qib_rwq *wq = qp->r_rq.wq;
896 		u32 head;
897 		u32 tail;
898 
899 		/* sanity check pointers before trusting them */
900 		head = wq->head;
901 		if (head >= qp->r_rq.size)
902 			head = 0;
903 		tail = wq->tail;
904 		if (tail >= qp->r_rq.size)
905 			tail = 0;
906 		/*
907 		 * Compute the number of credits available (RWQEs).
908 		 * XXX Not holding the r_rq.lock here so there is a small
909 		 * chance that the pair of reads are not atomic.
910 		 */
911 		credits = head - tail;
912 		if ((int)credits < 0)
913 			credits += qp->r_rq.size;
914 		/*
915 		 * Binary search the credit table to find the code to
916 		 * use.
917 		 */
918 		min = 0;
919 		max = 31;
920 		for (;;) {
921 			x = (min + max) / 2;
922 			if (credit_table[x] == credits)
923 				break;
924 			if (credit_table[x] > credits)
925 				max = x;
926 			else if (min == x)
927 				break;
928 			else
929 				min = x;
930 		}
931 		aeth |= x << QIB_AETH_CREDIT_SHIFT;
932 	}
933 	return cpu_to_be32(aeth);
934 }
935 
936 /**
937  * qib_create_qp - create a queue pair for a device
938  * @ibpd: the protection domain who's device we create the queue pair for
939  * @init_attr: the attributes of the queue pair
940  * @udata: user data for libibverbs.so
941  *
942  * Returns the queue pair on success, otherwise returns an errno.
943  *
944  * Called by the ib_create_qp() core verbs function.
945  */
qib_create_qp(struct ib_pd * ibpd,struct ib_qp_init_attr * init_attr,struct ib_udata * udata)946 struct ib_qp *qib_create_qp(struct ib_pd *ibpd,
947 			    struct ib_qp_init_attr *init_attr,
948 			    struct ib_udata *udata)
949 {
950 	struct qib_qp *qp;
951 	int err;
952 	struct qib_swqe *swq = NULL;
953 	struct qib_ibdev *dev;
954 	struct qib_devdata *dd;
955 	size_t sz;
956 	size_t sg_list_sz;
957 	struct ib_qp *ret;
958 
959 	if (init_attr->cap.max_send_sge > ib_qib_max_sges ||
960 	    init_attr->cap.max_send_wr > ib_qib_max_qp_wrs) {
961 		ret = ERR_PTR(-EINVAL);
962 		goto bail;
963 	}
964 
965 	/* Check receive queue parameters if no SRQ is specified. */
966 	if (!init_attr->srq) {
967 		if (init_attr->cap.max_recv_sge > ib_qib_max_sges ||
968 		    init_attr->cap.max_recv_wr > ib_qib_max_qp_wrs) {
969 			ret = ERR_PTR(-EINVAL);
970 			goto bail;
971 		}
972 		if (init_attr->cap.max_send_sge +
973 		    init_attr->cap.max_send_wr +
974 		    init_attr->cap.max_recv_sge +
975 		    init_attr->cap.max_recv_wr == 0) {
976 			ret = ERR_PTR(-EINVAL);
977 			goto bail;
978 		}
979 	}
980 
981 	switch (init_attr->qp_type) {
982 	case IB_QPT_SMI:
983 	case IB_QPT_GSI:
984 		if (init_attr->port_num == 0 ||
985 		    init_attr->port_num > ibpd->device->phys_port_cnt) {
986 			ret = ERR_PTR(-EINVAL);
987 			goto bail;
988 		}
989 	case IB_QPT_UC:
990 	case IB_QPT_RC:
991 	case IB_QPT_UD:
992 		sz = sizeof(struct qib_sge) *
993 			init_attr->cap.max_send_sge +
994 			sizeof(struct qib_swqe);
995 		swq = vmalloc((init_attr->cap.max_send_wr + 1) * sz);
996 		if (swq == NULL) {
997 			ret = ERR_PTR(-ENOMEM);
998 			goto bail;
999 		}
1000 		sz = sizeof(*qp);
1001 		sg_list_sz = 0;
1002 		if (init_attr->srq) {
1003 			struct qib_srq *srq = to_isrq(init_attr->srq);
1004 
1005 			if (srq->rq.max_sge > 1)
1006 				sg_list_sz = sizeof(*qp->r_sg_list) *
1007 					(srq->rq.max_sge - 1);
1008 		} else if (init_attr->cap.max_recv_sge > 1)
1009 			sg_list_sz = sizeof(*qp->r_sg_list) *
1010 				(init_attr->cap.max_recv_sge - 1);
1011 		qp = kzalloc(sz + sg_list_sz, GFP_KERNEL);
1012 		if (!qp) {
1013 			ret = ERR_PTR(-ENOMEM);
1014 			goto bail_swq;
1015 		}
1016 		if (init_attr->srq)
1017 			sz = 0;
1018 		else {
1019 			qp->r_rq.size = init_attr->cap.max_recv_wr + 1;
1020 			qp->r_rq.max_sge = init_attr->cap.max_recv_sge;
1021 			sz = (sizeof(struct ib_sge) * qp->r_rq.max_sge) +
1022 				sizeof(struct qib_rwqe);
1023 			qp->r_rq.wq = vmalloc_user(sizeof(struct qib_rwq) +
1024 						   qp->r_rq.size * sz);
1025 			if (!qp->r_rq.wq) {
1026 				ret = ERR_PTR(-ENOMEM);
1027 				goto bail_qp;
1028 			}
1029 		}
1030 
1031 		/*
1032 		 * ib_create_qp() will initialize qp->ibqp
1033 		 * except for qp->ibqp.qp_num.
1034 		 */
1035 		spin_lock_init(&qp->r_lock);
1036 		spin_lock_init(&qp->s_lock);
1037 		spin_lock_init(&qp->r_rq.lock);
1038 		atomic_set(&qp->refcount, 0);
1039 		init_waitqueue_head(&qp->wait);
1040 		init_waitqueue_head(&qp->wait_dma);
1041 		init_timer(&qp->s_timer);
1042 		qp->s_timer.data = (unsigned long)qp;
1043 		INIT_WORK(&qp->s_work, qib_do_send);
1044 		INIT_LIST_HEAD(&qp->iowait);
1045 		INIT_LIST_HEAD(&qp->rspwait);
1046 		qp->state = IB_QPS_RESET;
1047 		qp->s_wq = swq;
1048 		qp->s_size = init_attr->cap.max_send_wr + 1;
1049 		qp->s_max_sge = init_attr->cap.max_send_sge;
1050 		if (init_attr->sq_sig_type == IB_SIGNAL_REQ_WR)
1051 			qp->s_flags = QIB_S_SIGNAL_REQ_WR;
1052 		dev = to_idev(ibpd->device);
1053 		dd = dd_from_dev(dev);
1054 		err = alloc_qpn(dd, &dev->qpn_table, init_attr->qp_type,
1055 				init_attr->port_num);
1056 		if (err < 0) {
1057 			ret = ERR_PTR(err);
1058 			vfree(qp->r_rq.wq);
1059 			goto bail_qp;
1060 		}
1061 		qp->ibqp.qp_num = err;
1062 		qp->port_num = init_attr->port_num;
1063 		qib_reset_qp(qp, init_attr->qp_type);
1064 		break;
1065 
1066 	default:
1067 		/* Don't support raw QPs */
1068 		ret = ERR_PTR(-ENOSYS);
1069 		goto bail;
1070 	}
1071 
1072 	init_attr->cap.max_inline_data = 0;
1073 
1074 	/*
1075 	 * Return the address of the RWQ as the offset to mmap.
1076 	 * See qib_mmap() for details.
1077 	 */
1078 	if (udata && udata->outlen >= sizeof(__u64)) {
1079 		if (!qp->r_rq.wq) {
1080 			__u64 offset = 0;
1081 
1082 			err = ib_copy_to_udata(udata, &offset,
1083 					       sizeof(offset));
1084 			if (err) {
1085 				ret = ERR_PTR(err);
1086 				goto bail_ip;
1087 			}
1088 		} else {
1089 			u32 s = sizeof(struct qib_rwq) + qp->r_rq.size * sz;
1090 
1091 			qp->ip = qib_create_mmap_info(dev, s,
1092 						      ibpd->uobject->context,
1093 						      qp->r_rq.wq);
1094 			if (!qp->ip) {
1095 				ret = ERR_PTR(-ENOMEM);
1096 				goto bail_ip;
1097 			}
1098 
1099 			err = ib_copy_to_udata(udata, &(qp->ip->offset),
1100 					       sizeof(qp->ip->offset));
1101 			if (err) {
1102 				ret = ERR_PTR(err);
1103 				goto bail_ip;
1104 			}
1105 		}
1106 	}
1107 
1108 	spin_lock(&dev->n_qps_lock);
1109 	if (dev->n_qps_allocated == ib_qib_max_qps) {
1110 		spin_unlock(&dev->n_qps_lock);
1111 		ret = ERR_PTR(-ENOMEM);
1112 		goto bail_ip;
1113 	}
1114 
1115 	dev->n_qps_allocated++;
1116 	spin_unlock(&dev->n_qps_lock);
1117 
1118 	if (qp->ip) {
1119 		spin_lock_irq(&dev->pending_lock);
1120 		list_add(&qp->ip->pending_mmaps, &dev->pending_mmaps);
1121 		spin_unlock_irq(&dev->pending_lock);
1122 	}
1123 
1124 	ret = &qp->ibqp;
1125 	goto bail;
1126 
1127 bail_ip:
1128 	if (qp->ip)
1129 		kref_put(&qp->ip->ref, qib_release_mmap_info);
1130 	else
1131 		vfree(qp->r_rq.wq);
1132 	free_qpn(&dev->qpn_table, qp->ibqp.qp_num);
1133 bail_qp:
1134 	kfree(qp);
1135 bail_swq:
1136 	vfree(swq);
1137 bail:
1138 	return ret;
1139 }
1140 
1141 /**
1142  * qib_destroy_qp - destroy a queue pair
1143  * @ibqp: the queue pair to destroy
1144  *
1145  * Returns 0 on success.
1146  *
1147  * Note that this can be called while the QP is actively sending or
1148  * receiving!
1149  */
qib_destroy_qp(struct ib_qp * ibqp)1150 int qib_destroy_qp(struct ib_qp *ibqp)
1151 {
1152 	struct qib_qp *qp = to_iqp(ibqp);
1153 	struct qib_ibdev *dev = to_idev(ibqp->device);
1154 
1155 	/* Make sure HW and driver activity is stopped. */
1156 	spin_lock_irq(&qp->s_lock);
1157 	if (qp->state != IB_QPS_RESET) {
1158 		qp->state = IB_QPS_RESET;
1159 		spin_lock(&dev->pending_lock);
1160 		if (!list_empty(&qp->iowait))
1161 			list_del_init(&qp->iowait);
1162 		spin_unlock(&dev->pending_lock);
1163 		qp->s_flags &= ~(QIB_S_TIMER | QIB_S_ANY_WAIT);
1164 		spin_unlock_irq(&qp->s_lock);
1165 		cancel_work_sync(&qp->s_work);
1166 		del_timer_sync(&qp->s_timer);
1167 		wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
1168 		if (qp->s_tx) {
1169 			qib_put_txreq(qp->s_tx);
1170 			qp->s_tx = NULL;
1171 		}
1172 		remove_qp(dev, qp);
1173 		wait_event(qp->wait, !atomic_read(&qp->refcount));
1174 		clear_mr_refs(qp, 1);
1175 	} else
1176 		spin_unlock_irq(&qp->s_lock);
1177 
1178 	/* all user's cleaned up, mark it available */
1179 	free_qpn(&dev->qpn_table, qp->ibqp.qp_num);
1180 	spin_lock(&dev->n_qps_lock);
1181 	dev->n_qps_allocated--;
1182 	spin_unlock(&dev->n_qps_lock);
1183 
1184 	if (qp->ip)
1185 		kref_put(&qp->ip->ref, qib_release_mmap_info);
1186 	else
1187 		vfree(qp->r_rq.wq);
1188 	vfree(qp->s_wq);
1189 	kfree(qp);
1190 	return 0;
1191 }
1192 
1193 /**
1194  * qib_init_qpn_table - initialize the QP number table for a device
1195  * @qpt: the QPN table
1196  */
qib_init_qpn_table(struct qib_devdata * dd,struct qib_qpn_table * qpt)1197 void qib_init_qpn_table(struct qib_devdata *dd, struct qib_qpn_table *qpt)
1198 {
1199 	spin_lock_init(&qpt->lock);
1200 	qpt->last = 1;          /* start with QPN 2 */
1201 	qpt->nmaps = 1;
1202 	qpt->mask = dd->qpn_mask;
1203 }
1204 
1205 /**
1206  * qib_free_qpn_table - free the QP number table for a device
1207  * @qpt: the QPN table
1208  */
qib_free_qpn_table(struct qib_qpn_table * qpt)1209 void qib_free_qpn_table(struct qib_qpn_table *qpt)
1210 {
1211 	int i;
1212 
1213 	for (i = 0; i < ARRAY_SIZE(qpt->map); i++)
1214 		if (qpt->map[i].page)
1215 			free_page((unsigned long) qpt->map[i].page);
1216 }
1217 
1218 /**
1219  * qib_get_credit - flush the send work queue of a QP
1220  * @qp: the qp who's send work queue to flush
1221  * @aeth: the Acknowledge Extended Transport Header
1222  *
1223  * The QP s_lock should be held.
1224  */
qib_get_credit(struct qib_qp * qp,u32 aeth)1225 void qib_get_credit(struct qib_qp *qp, u32 aeth)
1226 {
1227 	u32 credit = (aeth >> QIB_AETH_CREDIT_SHIFT) & QIB_AETH_CREDIT_MASK;
1228 
1229 	/*
1230 	 * If the credit is invalid, we can send
1231 	 * as many packets as we like.  Otherwise, we have to
1232 	 * honor the credit field.
1233 	 */
1234 	if (credit == QIB_AETH_CREDIT_INVAL) {
1235 		if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) {
1236 			qp->s_flags |= QIB_S_UNLIMITED_CREDIT;
1237 			if (qp->s_flags & QIB_S_WAIT_SSN_CREDIT) {
1238 				qp->s_flags &= ~QIB_S_WAIT_SSN_CREDIT;
1239 				qib_schedule_send(qp);
1240 			}
1241 		}
1242 	} else if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) {
1243 		/* Compute new LSN (i.e., MSN + credit) */
1244 		credit = (aeth + credit_table[credit]) & QIB_MSN_MASK;
1245 		if (qib_cmp24(credit, qp->s_lsn) > 0) {
1246 			qp->s_lsn = credit;
1247 			if (qp->s_flags & QIB_S_WAIT_SSN_CREDIT) {
1248 				qp->s_flags &= ~QIB_S_WAIT_SSN_CREDIT;
1249 				qib_schedule_send(qp);
1250 			}
1251 		}
1252 	}
1253 }
1254