1 /*
2  * Copyright (c) 2006 Mellanox Technologies. All rights reserved
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #include <rdma/ib_cm.h>
34 #include <net/dst.h>
35 #include <net/icmp.h>
36 #include <linux/icmpv6.h>
37 #include <linux/delay.h>
38 #include <linux/slab.h>
39 #include <linux/vmalloc.h>
40 #include <linux/moduleparam.h>
41 
42 #include "ipoib.h"
43 
44 int ipoib_max_conn_qp = 128;
45 
46 module_param_named(max_nonsrq_conn_qp, ipoib_max_conn_qp, int, 0444);
47 MODULE_PARM_DESC(max_nonsrq_conn_qp,
48 		 "Max number of connected-mode QPs per interface "
49 		 "(applied only if shared receive queue is not available)");
50 
51 #ifdef CONFIG_INFINIBAND_IPOIB_DEBUG_DATA
52 static int data_debug_level;
53 
54 module_param_named(cm_data_debug_level, data_debug_level, int, 0644);
55 MODULE_PARM_DESC(cm_data_debug_level,
56 		 "Enable data path debug tracing for connected mode if > 0");
57 #endif
58 
59 #define IPOIB_CM_IETF_ID 0x1000000000000000ULL
60 
61 #define IPOIB_CM_RX_UPDATE_TIME (256 * HZ)
62 #define IPOIB_CM_RX_TIMEOUT     (2 * 256 * HZ)
63 #define IPOIB_CM_RX_DELAY       (3 * 256 * HZ)
64 #define IPOIB_CM_RX_UPDATE_MASK (0x3)
65 
66 static struct ib_qp_attr ipoib_cm_err_attr = {
67 	.qp_state = IB_QPS_ERR
68 };
69 
70 #define IPOIB_CM_RX_DRAIN_WRID 0xffffffff
71 
72 static struct ib_send_wr ipoib_cm_rx_drain_wr = {
73 	.wr_id = IPOIB_CM_RX_DRAIN_WRID,
74 	.opcode = IB_WR_SEND,
75 };
76 
77 static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
78 			       struct ib_cm_event *event);
79 
80 static void ipoib_cm_dma_unmap_rx(struct ipoib_dev_priv *priv, int frags,
81 				  u64 mapping[IPOIB_CM_RX_SG])
82 {
83 	int i;
84 
85 	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
86 
87 	for (i = 0; i < frags; ++i)
88 		ib_dma_unmap_page(priv->ca, mapping[i + 1], PAGE_SIZE, DMA_FROM_DEVICE);
89 }
90 
91 static int ipoib_cm_post_receive_srq(struct net_device *dev, int id)
92 {
93 	struct ipoib_dev_priv *priv = netdev_priv(dev);
94 	struct ib_recv_wr *bad_wr;
95 	int i, ret;
96 
97 	priv->cm.rx_wr.wr_id = id | IPOIB_OP_CM | IPOIB_OP_RECV;
98 
99 	for (i = 0; i < priv->cm.num_frags; ++i)
100 		priv->cm.rx_sge[i].addr = priv->cm.srq_ring[id].mapping[i];
101 
102 	ret = ib_post_srq_recv(priv->cm.srq, &priv->cm.rx_wr, &bad_wr);
103 	if (unlikely(ret)) {
104 		ipoib_warn(priv, "post srq failed for buf %d (%d)\n", id, ret);
105 		ipoib_cm_dma_unmap_rx(priv, priv->cm.num_frags - 1,
106 				      priv->cm.srq_ring[id].mapping);
107 		dev_kfree_skb_any(priv->cm.srq_ring[id].skb);
108 		priv->cm.srq_ring[id].skb = NULL;
109 	}
110 
111 	return ret;
112 }
113 
114 static int ipoib_cm_post_receive_nonsrq(struct net_device *dev,
115 					struct ipoib_cm_rx *rx,
116 					struct ib_recv_wr *wr,
117 					struct ib_sge *sge, int id)
118 {
119 	struct ipoib_dev_priv *priv = netdev_priv(dev);
120 	struct ib_recv_wr *bad_wr;
121 	int i, ret;
122 
123 	wr->wr_id = id | IPOIB_OP_CM | IPOIB_OP_RECV;
124 
125 	for (i = 0; i < IPOIB_CM_RX_SG; ++i)
126 		sge[i].addr = rx->rx_ring[id].mapping[i];
127 
128 	ret = ib_post_recv(rx->qp, wr, &bad_wr);
129 	if (unlikely(ret)) {
130 		ipoib_warn(priv, "post recv failed for buf %d (%d)\n", id, ret);
131 		ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
132 				      rx->rx_ring[id].mapping);
133 		dev_kfree_skb_any(rx->rx_ring[id].skb);
134 		rx->rx_ring[id].skb = NULL;
135 	}
136 
137 	return ret;
138 }
139 
140 static struct sk_buff *ipoib_cm_alloc_rx_skb(struct net_device *dev,
141 					     struct ipoib_cm_rx_buf *rx_ring,
142 					     int id, int frags,
143 					     u64 mapping[IPOIB_CM_RX_SG])
144 {
145 	struct ipoib_dev_priv *priv = netdev_priv(dev);
146 	struct sk_buff *skb;
147 	int i;
148 
149 	skb = dev_alloc_skb(IPOIB_CM_HEAD_SIZE + 12);
150 	if (unlikely(!skb))
151 		return NULL;
152 
153 	/*
154 	 * IPoIB adds a 4 byte header. So we need 12 more bytes to align the
155 	 * IP header to a multiple of 16.
156 	 */
157 	skb_reserve(skb, 12);
158 
159 	mapping[0] = ib_dma_map_single(priv->ca, skb->data, IPOIB_CM_HEAD_SIZE,
160 				       DMA_FROM_DEVICE);
161 	if (unlikely(ib_dma_mapping_error(priv->ca, mapping[0]))) {
162 		dev_kfree_skb_any(skb);
163 		return NULL;
164 	}
165 
166 	for (i = 0; i < frags; i++) {
167 		struct page *page = alloc_page(GFP_ATOMIC);
168 
169 		if (!page)
170 			goto partial_error;
171 		skb_fill_page_desc(skb, i, page, 0, PAGE_SIZE);
172 
173 		mapping[i + 1] = ib_dma_map_page(priv->ca, page,
174 						 0, PAGE_SIZE, DMA_FROM_DEVICE);
175 		if (unlikely(ib_dma_mapping_error(priv->ca, mapping[i + 1])))
176 			goto partial_error;
177 	}
178 
179 	rx_ring[id].skb = skb;
180 	return skb;
181 
182 partial_error:
183 
184 	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
185 
186 	for (; i > 0; --i)
187 		ib_dma_unmap_page(priv->ca, mapping[i], PAGE_SIZE, DMA_FROM_DEVICE);
188 
189 	dev_kfree_skb_any(skb);
190 	return NULL;
191 }
192 
193 static void ipoib_cm_free_rx_ring(struct net_device *dev,
194 				  struct ipoib_cm_rx_buf *rx_ring)
195 {
196 	struct ipoib_dev_priv *priv = netdev_priv(dev);
197 	int i;
198 
199 	for (i = 0; i < ipoib_recvq_size; ++i)
200 		if (rx_ring[i].skb) {
201 			ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
202 					      rx_ring[i].mapping);
203 			dev_kfree_skb_any(rx_ring[i].skb);
204 		}
205 
206 	vfree(rx_ring);
207 }
208 
209 static void ipoib_cm_start_rx_drain(struct ipoib_dev_priv *priv)
210 {
211 	struct ib_send_wr *bad_wr;
212 	struct ipoib_cm_rx *p;
213 
214 	/* We only reserved 1 extra slot in CQ for drain WRs, so
215 	 * make sure we have at most 1 outstanding WR. */
216 	if (list_empty(&priv->cm.rx_flush_list) ||
217 	    !list_empty(&priv->cm.rx_drain_list))
218 		return;
219 
220 	/*
221 	 * QPs on flush list are error state.  This way, a "flush
222 	 * error" WC will be immediately generated for each WR we post.
223 	 */
224 	p = list_entry(priv->cm.rx_flush_list.next, typeof(*p), list);
225 	if (ib_post_send(p->qp, &ipoib_cm_rx_drain_wr, &bad_wr))
226 		ipoib_warn(priv, "failed to post drain wr\n");
227 
228 	list_splice_init(&priv->cm.rx_flush_list, &priv->cm.rx_drain_list);
229 }
230 
231 static void ipoib_cm_rx_event_handler(struct ib_event *event, void *ctx)
232 {
233 	struct ipoib_cm_rx *p = ctx;
234 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
235 	unsigned long flags;
236 
237 	if (event->event != IB_EVENT_QP_LAST_WQE_REACHED)
238 		return;
239 
240 	spin_lock_irqsave(&priv->lock, flags);
241 	list_move(&p->list, &priv->cm.rx_flush_list);
242 	p->state = IPOIB_CM_RX_FLUSH;
243 	ipoib_cm_start_rx_drain(priv);
244 	spin_unlock_irqrestore(&priv->lock, flags);
245 }
246 
247 static struct ib_qp *ipoib_cm_create_rx_qp(struct net_device *dev,
248 					   struct ipoib_cm_rx *p)
249 {
250 	struct ipoib_dev_priv *priv = netdev_priv(dev);
251 	struct ib_qp_init_attr attr = {
252 		.event_handler = ipoib_cm_rx_event_handler,
253 		.send_cq = priv->recv_cq, /* For drain WR */
254 		.recv_cq = priv->recv_cq,
255 		.srq = priv->cm.srq,
256 		.cap.max_send_wr = 1, /* For drain WR */
257 		.cap.max_send_sge = 1, /* FIXME: 0 Seems not to work */
258 		.sq_sig_type = IB_SIGNAL_ALL_WR,
259 		.qp_type = IB_QPT_RC,
260 		.qp_context = p,
261 	};
262 
263 	if (!ipoib_cm_has_srq(dev)) {
264 		attr.cap.max_recv_wr  = ipoib_recvq_size;
265 		attr.cap.max_recv_sge = IPOIB_CM_RX_SG;
266 	}
267 
268 	return ib_create_qp(priv->pd, &attr);
269 }
270 
271 static int ipoib_cm_modify_rx_qp(struct net_device *dev,
272 				 struct ib_cm_id *cm_id, struct ib_qp *qp,
273 				 unsigned psn)
274 {
275 	struct ipoib_dev_priv *priv = netdev_priv(dev);
276 	struct ib_qp_attr qp_attr;
277 	int qp_attr_mask, ret;
278 
279 	qp_attr.qp_state = IB_QPS_INIT;
280 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
281 	if (ret) {
282 		ipoib_warn(priv, "failed to init QP attr for INIT: %d\n", ret);
283 		return ret;
284 	}
285 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
286 	if (ret) {
287 		ipoib_warn(priv, "failed to modify QP to INIT: %d\n", ret);
288 		return ret;
289 	}
290 	qp_attr.qp_state = IB_QPS_RTR;
291 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
292 	if (ret) {
293 		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
294 		return ret;
295 	}
296 	qp_attr.rq_psn = psn;
297 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
298 	if (ret) {
299 		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
300 		return ret;
301 	}
302 
303 	/*
304 	 * Current Mellanox HCA firmware won't generate completions
305 	 * with error for drain WRs unless the QP has been moved to
306 	 * RTS first. This work-around leaves a window where a QP has
307 	 * moved to error asynchronously, but this will eventually get
308 	 * fixed in firmware, so let's not error out if modify QP
309 	 * fails.
310 	 */
311 	qp_attr.qp_state = IB_QPS_RTS;
312 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
313 	if (ret) {
314 		ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret);
315 		return 0;
316 	}
317 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
318 	if (ret) {
319 		ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret);
320 		return 0;
321 	}
322 
323 	return 0;
324 }
325 
326 static void ipoib_cm_init_rx_wr(struct net_device *dev,
327 				struct ib_recv_wr *wr,
328 				struct ib_sge *sge)
329 {
330 	struct ipoib_dev_priv *priv = netdev_priv(dev);
331 	int i;
332 
333 	for (i = 0; i < priv->cm.num_frags; ++i)
334 		sge[i].lkey = priv->mr->lkey;
335 
336 	sge[0].length = IPOIB_CM_HEAD_SIZE;
337 	for (i = 1; i < priv->cm.num_frags; ++i)
338 		sge[i].length = PAGE_SIZE;
339 
340 	wr->next    = NULL;
341 	wr->sg_list = sge;
342 	wr->num_sge = priv->cm.num_frags;
343 }
344 
345 static int ipoib_cm_nonsrq_init_rx(struct net_device *dev, struct ib_cm_id *cm_id,
346 				   struct ipoib_cm_rx *rx)
347 {
348 	struct ipoib_dev_priv *priv = netdev_priv(dev);
349 	struct {
350 		struct ib_recv_wr wr;
351 		struct ib_sge sge[IPOIB_CM_RX_SG];
352 	} *t;
353 	int ret;
354 	int i;
355 
356 	rx->rx_ring = vzalloc(ipoib_recvq_size * sizeof *rx->rx_ring);
357 	if (!rx->rx_ring) {
358 		printk(KERN_WARNING "%s: failed to allocate CM non-SRQ ring (%d entries)\n",
359 		       priv->ca->name, ipoib_recvq_size);
360 		return -ENOMEM;
361 	}
362 
363 	t = kmalloc(sizeof *t, GFP_KERNEL);
364 	if (!t) {
365 		ret = -ENOMEM;
366 		goto err_free;
367 	}
368 
369 	ipoib_cm_init_rx_wr(dev, &t->wr, t->sge);
370 
371 	spin_lock_irq(&priv->lock);
372 
373 	if (priv->cm.nonsrq_conn_qp >= ipoib_max_conn_qp) {
374 		spin_unlock_irq(&priv->lock);
375 		ib_send_cm_rej(cm_id, IB_CM_REJ_NO_QP, NULL, 0, NULL, 0);
376 		ret = -EINVAL;
377 		goto err_free;
378 	} else
379 		++priv->cm.nonsrq_conn_qp;
380 
381 	spin_unlock_irq(&priv->lock);
382 
383 	for (i = 0; i < ipoib_recvq_size; ++i) {
384 		if (!ipoib_cm_alloc_rx_skb(dev, rx->rx_ring, i, IPOIB_CM_RX_SG - 1,
385 					   rx->rx_ring[i].mapping)) {
386 			ipoib_warn(priv, "failed to allocate receive buffer %d\n", i);
387 				ret = -ENOMEM;
388 				goto err_count;
389 		}
390 		ret = ipoib_cm_post_receive_nonsrq(dev, rx, &t->wr, t->sge, i);
391 		if (ret) {
392 			ipoib_warn(priv, "ipoib_cm_post_receive_nonsrq "
393 				   "failed for buf %d\n", i);
394 			ret = -EIO;
395 			goto err_count;
396 		}
397 	}
398 
399 	rx->recv_count = ipoib_recvq_size;
400 
401 	kfree(t);
402 
403 	return 0;
404 
405 err_count:
406 	spin_lock_irq(&priv->lock);
407 	--priv->cm.nonsrq_conn_qp;
408 	spin_unlock_irq(&priv->lock);
409 
410 err_free:
411 	kfree(t);
412 	ipoib_cm_free_rx_ring(dev, rx->rx_ring);
413 
414 	return ret;
415 }
416 
417 static int ipoib_cm_send_rep(struct net_device *dev, struct ib_cm_id *cm_id,
418 			     struct ib_qp *qp, struct ib_cm_req_event_param *req,
419 			     unsigned psn)
420 {
421 	struct ipoib_dev_priv *priv = netdev_priv(dev);
422 	struct ipoib_cm_data data = {};
423 	struct ib_cm_rep_param rep = {};
424 
425 	data.qpn = cpu_to_be32(priv->qp->qp_num);
426 	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
427 
428 	rep.private_data = &data;
429 	rep.private_data_len = sizeof data;
430 	rep.flow_control = 0;
431 	rep.rnr_retry_count = req->rnr_retry_count;
432 	rep.srq = ipoib_cm_has_srq(dev);
433 	rep.qp_num = qp->qp_num;
434 	rep.starting_psn = psn;
435 	return ib_send_cm_rep(cm_id, &rep);
436 }
437 
438 static int ipoib_cm_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
439 {
440 	struct net_device *dev = cm_id->context;
441 	struct ipoib_dev_priv *priv = netdev_priv(dev);
442 	struct ipoib_cm_rx *p;
443 	unsigned psn;
444 	int ret;
445 
446 	ipoib_dbg(priv, "REQ arrived\n");
447 	p = kzalloc(sizeof *p, GFP_KERNEL);
448 	if (!p)
449 		return -ENOMEM;
450 	p->dev = dev;
451 	p->id = cm_id;
452 	cm_id->context = p;
453 	p->state = IPOIB_CM_RX_LIVE;
454 	p->jiffies = jiffies;
455 	INIT_LIST_HEAD(&p->list);
456 
457 	p->qp = ipoib_cm_create_rx_qp(dev, p);
458 	if (IS_ERR(p->qp)) {
459 		ret = PTR_ERR(p->qp);
460 		goto err_qp;
461 	}
462 
463 	psn = prandom_u32() & 0xffffff;
464 	ret = ipoib_cm_modify_rx_qp(dev, cm_id, p->qp, psn);
465 	if (ret)
466 		goto err_modify;
467 
468 	if (!ipoib_cm_has_srq(dev)) {
469 		ret = ipoib_cm_nonsrq_init_rx(dev, cm_id, p);
470 		if (ret)
471 			goto err_modify;
472 	}
473 
474 	spin_lock_irq(&priv->lock);
475 	queue_delayed_work(ipoib_workqueue,
476 			   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
477 	/* Add this entry to passive ids list head, but do not re-add it
478 	 * if IB_EVENT_QP_LAST_WQE_REACHED has moved it to flush list. */
479 	p->jiffies = jiffies;
480 	if (p->state == IPOIB_CM_RX_LIVE)
481 		list_move(&p->list, &priv->cm.passive_ids);
482 	spin_unlock_irq(&priv->lock);
483 
484 	ret = ipoib_cm_send_rep(dev, cm_id, p->qp, &event->param.req_rcvd, psn);
485 	if (ret) {
486 		ipoib_warn(priv, "failed to send REP: %d\n", ret);
487 		if (ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE))
488 			ipoib_warn(priv, "unable to move qp to error state\n");
489 	}
490 	return 0;
491 
492 err_modify:
493 	ib_destroy_qp(p->qp);
494 err_qp:
495 	kfree(p);
496 	return ret;
497 }
498 
499 static int ipoib_cm_rx_handler(struct ib_cm_id *cm_id,
500 			       struct ib_cm_event *event)
501 {
502 	struct ipoib_cm_rx *p;
503 	struct ipoib_dev_priv *priv;
504 
505 	switch (event->event) {
506 	case IB_CM_REQ_RECEIVED:
507 		return ipoib_cm_req_handler(cm_id, event);
508 	case IB_CM_DREQ_RECEIVED:
509 		p = cm_id->context;
510 		ib_send_cm_drep(cm_id, NULL, 0);
511 		/* Fall through */
512 	case IB_CM_REJ_RECEIVED:
513 		p = cm_id->context;
514 		priv = netdev_priv(p->dev);
515 		if (ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE))
516 			ipoib_warn(priv, "unable to move qp to error state\n");
517 		/* Fall through */
518 	default:
519 		return 0;
520 	}
521 }
522 /* Adjust length of skb with fragments to match received data */
523 static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space,
524 			  unsigned int length, struct sk_buff *toskb)
525 {
526 	int i, num_frags;
527 	unsigned int size;
528 
529 	/* put header into skb */
530 	size = min(length, hdr_space);
531 	skb->tail += size;
532 	skb->len += size;
533 	length -= size;
534 
535 	num_frags = skb_shinfo(skb)->nr_frags;
536 	for (i = 0; i < num_frags; i++) {
537 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
538 
539 		if (length == 0) {
540 			/* don't need this page */
541 			skb_fill_page_desc(toskb, i, skb_frag_page(frag),
542 					   0, PAGE_SIZE);
543 			--skb_shinfo(skb)->nr_frags;
544 		} else {
545 			size = min(length, (unsigned) PAGE_SIZE);
546 
547 			skb_frag_size_set(frag, size);
548 			skb->data_len += size;
549 			skb->truesize += size;
550 			skb->len += size;
551 			length -= size;
552 		}
553 	}
554 }
555 
556 void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
557 {
558 	struct ipoib_dev_priv *priv = netdev_priv(dev);
559 	struct ipoib_cm_rx_buf *rx_ring;
560 	unsigned int wr_id = wc->wr_id & ~(IPOIB_OP_CM | IPOIB_OP_RECV);
561 	struct sk_buff *skb, *newskb;
562 	struct ipoib_cm_rx *p;
563 	unsigned long flags;
564 	u64 mapping[IPOIB_CM_RX_SG];
565 	int frags;
566 	int has_srq;
567 	struct sk_buff *small_skb;
568 
569 	ipoib_dbg_data(priv, "cm recv completion: id %d, status: %d\n",
570 		       wr_id, wc->status);
571 
572 	if (unlikely(wr_id >= ipoib_recvq_size)) {
573 		if (wr_id == (IPOIB_CM_RX_DRAIN_WRID & ~(IPOIB_OP_CM | IPOIB_OP_RECV))) {
574 			spin_lock_irqsave(&priv->lock, flags);
575 			list_splice_init(&priv->cm.rx_drain_list, &priv->cm.rx_reap_list);
576 			ipoib_cm_start_rx_drain(priv);
577 			queue_work(ipoib_workqueue, &priv->cm.rx_reap_task);
578 			spin_unlock_irqrestore(&priv->lock, flags);
579 		} else
580 			ipoib_warn(priv, "cm recv completion event with wrid %d (> %d)\n",
581 				   wr_id, ipoib_recvq_size);
582 		return;
583 	}
584 
585 	p = wc->qp->qp_context;
586 
587 	has_srq = ipoib_cm_has_srq(dev);
588 	rx_ring = has_srq ? priv->cm.srq_ring : p->rx_ring;
589 
590 	skb = rx_ring[wr_id].skb;
591 
592 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
593 		ipoib_dbg(priv, "cm recv error "
594 			   "(status=%d, wrid=%d vend_err %x)\n",
595 			   wc->status, wr_id, wc->vendor_err);
596 		++dev->stats.rx_dropped;
597 		if (has_srq)
598 			goto repost;
599 		else {
600 			if (!--p->recv_count) {
601 				spin_lock_irqsave(&priv->lock, flags);
602 				list_move(&p->list, &priv->cm.rx_reap_list);
603 				spin_unlock_irqrestore(&priv->lock, flags);
604 				queue_work(ipoib_workqueue, &priv->cm.rx_reap_task);
605 			}
606 			return;
607 		}
608 	}
609 
610 	if (unlikely(!(wr_id & IPOIB_CM_RX_UPDATE_MASK))) {
611 		if (p && time_after_eq(jiffies, p->jiffies + IPOIB_CM_RX_UPDATE_TIME)) {
612 			spin_lock_irqsave(&priv->lock, flags);
613 			p->jiffies = jiffies;
614 			/* Move this entry to list head, but do not re-add it
615 			 * if it has been moved out of list. */
616 			if (p->state == IPOIB_CM_RX_LIVE)
617 				list_move(&p->list, &priv->cm.passive_ids);
618 			spin_unlock_irqrestore(&priv->lock, flags);
619 		}
620 	}
621 
622 	if (wc->byte_len < IPOIB_CM_COPYBREAK) {
623 		int dlen = wc->byte_len;
624 
625 		small_skb = dev_alloc_skb(dlen + 12);
626 		if (small_skb) {
627 			skb_reserve(small_skb, 12);
628 			ib_dma_sync_single_for_cpu(priv->ca, rx_ring[wr_id].mapping[0],
629 						   dlen, DMA_FROM_DEVICE);
630 			skb_copy_from_linear_data(skb, small_skb->data, dlen);
631 			ib_dma_sync_single_for_device(priv->ca, rx_ring[wr_id].mapping[0],
632 						      dlen, DMA_FROM_DEVICE);
633 			skb_put(small_skb, dlen);
634 			skb = small_skb;
635 			goto copied;
636 		}
637 	}
638 
639 	frags = PAGE_ALIGN(wc->byte_len - min(wc->byte_len,
640 					      (unsigned)IPOIB_CM_HEAD_SIZE)) / PAGE_SIZE;
641 
642 	newskb = ipoib_cm_alloc_rx_skb(dev, rx_ring, wr_id, frags, mapping);
643 	if (unlikely(!newskb)) {
644 		/*
645 		 * If we can't allocate a new RX buffer, dump
646 		 * this packet and reuse the old buffer.
647 		 */
648 		ipoib_dbg(priv, "failed to allocate receive buffer %d\n", wr_id);
649 		++dev->stats.rx_dropped;
650 		goto repost;
651 	}
652 
653 	ipoib_cm_dma_unmap_rx(priv, frags, rx_ring[wr_id].mapping);
654 	memcpy(rx_ring[wr_id].mapping, mapping, (frags + 1) * sizeof *mapping);
655 
656 	ipoib_dbg_data(priv, "received %d bytes, SLID 0x%04x\n",
657 		       wc->byte_len, wc->slid);
658 
659 	skb_put_frags(skb, IPOIB_CM_HEAD_SIZE, wc->byte_len, newskb);
660 
661 copied:
662 	skb->protocol = ((struct ipoib_header *) skb->data)->proto;
663 	skb_reset_mac_header(skb);
664 	skb_pull(skb, IPOIB_ENCAP_LEN);
665 
666 	++dev->stats.rx_packets;
667 	dev->stats.rx_bytes += skb->len;
668 
669 	skb->dev = dev;
670 	/* XXX get correct PACKET_ type here */
671 	skb->pkt_type = PACKET_HOST;
672 	netif_receive_skb(skb);
673 
674 repost:
675 	if (has_srq) {
676 		if (unlikely(ipoib_cm_post_receive_srq(dev, wr_id)))
677 			ipoib_warn(priv, "ipoib_cm_post_receive_srq failed "
678 				   "for buf %d\n", wr_id);
679 	} else {
680 		if (unlikely(ipoib_cm_post_receive_nonsrq(dev, p,
681 							  &priv->cm.rx_wr,
682 							  priv->cm.rx_sge,
683 							  wr_id))) {
684 			--p->recv_count;
685 			ipoib_warn(priv, "ipoib_cm_post_receive_nonsrq failed "
686 				   "for buf %d\n", wr_id);
687 		}
688 	}
689 }
690 
691 static inline int post_send(struct ipoib_dev_priv *priv,
692 			    struct ipoib_cm_tx *tx,
693 			    unsigned int wr_id,
694 			    u64 addr, int len)
695 {
696 	struct ib_send_wr *bad_wr;
697 
698 	priv->tx_sge[0].addr          = addr;
699 	priv->tx_sge[0].length        = len;
700 
701 	priv->tx_wr.num_sge	= 1;
702 	priv->tx_wr.wr_id	= wr_id | IPOIB_OP_CM;
703 
704 	return ib_post_send(tx->qp, &priv->tx_wr, &bad_wr);
705 }
706 
707 void ipoib_cm_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_cm_tx *tx)
708 {
709 	struct ipoib_dev_priv *priv = netdev_priv(dev);
710 	struct ipoib_cm_tx_buf *tx_req;
711 	u64 addr;
712 	int rc;
713 
714 	if (unlikely(skb->len > tx->mtu)) {
715 		ipoib_warn(priv, "packet len %d (> %d) too long to send, dropping\n",
716 			   skb->len, tx->mtu);
717 		++dev->stats.tx_dropped;
718 		++dev->stats.tx_errors;
719 		ipoib_cm_skb_too_long(dev, skb, tx->mtu - IPOIB_ENCAP_LEN);
720 		return;
721 	}
722 
723 	ipoib_dbg_data(priv, "sending packet: head 0x%x length %d connection 0x%x\n",
724 		       tx->tx_head, skb->len, tx->qp->qp_num);
725 
726 	/*
727 	 * We put the skb into the tx_ring _before_ we call post_send()
728 	 * because it's entirely possible that the completion handler will
729 	 * run before we execute anything after the post_send().  That
730 	 * means we have to make sure everything is properly recorded and
731 	 * our state is consistent before we call post_send().
732 	 */
733 	tx_req = &tx->tx_ring[tx->tx_head & (ipoib_sendq_size - 1)];
734 	tx_req->skb = skb;
735 	addr = ib_dma_map_single(priv->ca, skb->data, skb->len, DMA_TO_DEVICE);
736 	if (unlikely(ib_dma_mapping_error(priv->ca, addr))) {
737 		++dev->stats.tx_errors;
738 		dev_kfree_skb_any(skb);
739 		return;
740 	}
741 
742 	tx_req->mapping = addr;
743 
744 	skb_orphan(skb);
745 	skb_dst_drop(skb);
746 
747 	rc = post_send(priv, tx, tx->tx_head & (ipoib_sendq_size - 1),
748 		       addr, skb->len);
749 	if (unlikely(rc)) {
750 		ipoib_warn(priv, "post_send failed, error %d\n", rc);
751 		++dev->stats.tx_errors;
752 		ib_dma_unmap_single(priv->ca, addr, skb->len, DMA_TO_DEVICE);
753 		dev_kfree_skb_any(skb);
754 	} else {
755 		dev->trans_start = jiffies;
756 		++tx->tx_head;
757 
758 		if (++priv->tx_outstanding == ipoib_sendq_size) {
759 			ipoib_dbg(priv, "TX ring 0x%x full, stopping kernel net queue\n",
760 				  tx->qp->qp_num);
761 			netif_stop_queue(dev);
762 			rc = ib_req_notify_cq(priv->send_cq,
763 				IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
764 			if (rc < 0)
765 				ipoib_warn(priv, "request notify on send CQ failed\n");
766 			else if (rc)
767 				ipoib_send_comp_handler(priv->send_cq, dev);
768 		}
769 	}
770 }
771 
772 void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ib_wc *wc)
773 {
774 	struct ipoib_dev_priv *priv = netdev_priv(dev);
775 	struct ipoib_cm_tx *tx = wc->qp->qp_context;
776 	unsigned int wr_id = wc->wr_id & ~IPOIB_OP_CM;
777 	struct ipoib_cm_tx_buf *tx_req;
778 	unsigned long flags;
779 
780 	ipoib_dbg_data(priv, "cm send completion: id %d, status: %d\n",
781 		       wr_id, wc->status);
782 
783 	if (unlikely(wr_id >= ipoib_sendq_size)) {
784 		ipoib_warn(priv, "cm send completion event with wrid %d (> %d)\n",
785 			   wr_id, ipoib_sendq_size);
786 		return;
787 	}
788 
789 	tx_req = &tx->tx_ring[wr_id];
790 
791 	ib_dma_unmap_single(priv->ca, tx_req->mapping, tx_req->skb->len, DMA_TO_DEVICE);
792 
793 	/* FIXME: is this right? Shouldn't we only increment on success? */
794 	++dev->stats.tx_packets;
795 	dev->stats.tx_bytes += tx_req->skb->len;
796 
797 	dev_kfree_skb_any(tx_req->skb);
798 
799 	netif_tx_lock(dev);
800 
801 	++tx->tx_tail;
802 	if (unlikely(--priv->tx_outstanding == ipoib_sendq_size >> 1) &&
803 	    netif_queue_stopped(dev) &&
804 	    test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
805 		netif_wake_queue(dev);
806 
807 	if (wc->status != IB_WC_SUCCESS &&
808 	    wc->status != IB_WC_WR_FLUSH_ERR) {
809 		struct ipoib_neigh *neigh;
810 
811 		ipoib_dbg(priv, "failed cm send event "
812 			   "(status=%d, wrid=%d vend_err %x)\n",
813 			   wc->status, wr_id, wc->vendor_err);
814 
815 		spin_lock_irqsave(&priv->lock, flags);
816 		neigh = tx->neigh;
817 
818 		if (neigh) {
819 			neigh->cm = NULL;
820 			ipoib_neigh_free(neigh);
821 
822 			tx->neigh = NULL;
823 		}
824 
825 		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
826 			list_move(&tx->list, &priv->cm.reap_list);
827 			queue_work(ipoib_workqueue, &priv->cm.reap_task);
828 		}
829 
830 		clear_bit(IPOIB_FLAG_OPER_UP, &tx->flags);
831 
832 		spin_unlock_irqrestore(&priv->lock, flags);
833 	}
834 
835 	netif_tx_unlock(dev);
836 }
837 
838 int ipoib_cm_dev_open(struct net_device *dev)
839 {
840 	struct ipoib_dev_priv *priv = netdev_priv(dev);
841 	int ret;
842 
843 	if (!IPOIB_CM_SUPPORTED(dev->dev_addr))
844 		return 0;
845 
846 	priv->cm.id = ib_create_cm_id(priv->ca, ipoib_cm_rx_handler, dev);
847 	if (IS_ERR(priv->cm.id)) {
848 		printk(KERN_WARNING "%s: failed to create CM ID\n", priv->ca->name);
849 		ret = PTR_ERR(priv->cm.id);
850 		goto err_cm;
851 	}
852 
853 	ret = ib_cm_listen(priv->cm.id, cpu_to_be64(IPOIB_CM_IETF_ID | priv->qp->qp_num),
854 			   0, NULL);
855 	if (ret) {
856 		printk(KERN_WARNING "%s: failed to listen on ID 0x%llx\n", priv->ca->name,
857 		       IPOIB_CM_IETF_ID | priv->qp->qp_num);
858 		goto err_listen;
859 	}
860 
861 	return 0;
862 
863 err_listen:
864 	ib_destroy_cm_id(priv->cm.id);
865 err_cm:
866 	priv->cm.id = NULL;
867 	return ret;
868 }
869 
870 static void ipoib_cm_free_rx_reap_list(struct net_device *dev)
871 {
872 	struct ipoib_dev_priv *priv = netdev_priv(dev);
873 	struct ipoib_cm_rx *rx, *n;
874 	LIST_HEAD(list);
875 
876 	spin_lock_irq(&priv->lock);
877 	list_splice_init(&priv->cm.rx_reap_list, &list);
878 	spin_unlock_irq(&priv->lock);
879 
880 	list_for_each_entry_safe(rx, n, &list, list) {
881 		ib_destroy_cm_id(rx->id);
882 		ib_destroy_qp(rx->qp);
883 		if (!ipoib_cm_has_srq(dev)) {
884 			ipoib_cm_free_rx_ring(priv->dev, rx->rx_ring);
885 			spin_lock_irq(&priv->lock);
886 			--priv->cm.nonsrq_conn_qp;
887 			spin_unlock_irq(&priv->lock);
888 		}
889 		kfree(rx);
890 	}
891 }
892 
893 void ipoib_cm_dev_stop(struct net_device *dev)
894 {
895 	struct ipoib_dev_priv *priv = netdev_priv(dev);
896 	struct ipoib_cm_rx *p;
897 	unsigned long begin;
898 	int ret;
899 
900 	if (!IPOIB_CM_SUPPORTED(dev->dev_addr) || !priv->cm.id)
901 		return;
902 
903 	ib_destroy_cm_id(priv->cm.id);
904 	priv->cm.id = NULL;
905 
906 	spin_lock_irq(&priv->lock);
907 	while (!list_empty(&priv->cm.passive_ids)) {
908 		p = list_entry(priv->cm.passive_ids.next, typeof(*p), list);
909 		list_move(&p->list, &priv->cm.rx_error_list);
910 		p->state = IPOIB_CM_RX_ERROR;
911 		spin_unlock_irq(&priv->lock);
912 		ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
913 		if (ret)
914 			ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
915 		spin_lock_irq(&priv->lock);
916 	}
917 
918 	/* Wait for all RX to be drained */
919 	begin = jiffies;
920 
921 	while (!list_empty(&priv->cm.rx_error_list) ||
922 	       !list_empty(&priv->cm.rx_flush_list) ||
923 	       !list_empty(&priv->cm.rx_drain_list)) {
924 		if (time_after(jiffies, begin + 5 * HZ)) {
925 			ipoib_warn(priv, "RX drain timing out\n");
926 
927 			/*
928 			 * assume the HW is wedged and just free up everything.
929 			 */
930 			list_splice_init(&priv->cm.rx_flush_list,
931 					 &priv->cm.rx_reap_list);
932 			list_splice_init(&priv->cm.rx_error_list,
933 					 &priv->cm.rx_reap_list);
934 			list_splice_init(&priv->cm.rx_drain_list,
935 					 &priv->cm.rx_reap_list);
936 			break;
937 		}
938 		spin_unlock_irq(&priv->lock);
939 		msleep(1);
940 		ipoib_drain_cq(dev);
941 		spin_lock_irq(&priv->lock);
942 	}
943 
944 	spin_unlock_irq(&priv->lock);
945 
946 	ipoib_cm_free_rx_reap_list(dev);
947 
948 	cancel_delayed_work(&priv->cm.stale_task);
949 }
950 
951 static int ipoib_cm_rep_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
952 {
953 	struct ipoib_cm_tx *p = cm_id->context;
954 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
955 	struct ipoib_cm_data *data = event->private_data;
956 	struct sk_buff_head skqueue;
957 	struct ib_qp_attr qp_attr;
958 	int qp_attr_mask, ret;
959 	struct sk_buff *skb;
960 
961 	p->mtu = be32_to_cpu(data->mtu);
962 
963 	if (p->mtu <= IPOIB_ENCAP_LEN) {
964 		ipoib_warn(priv, "Rejecting connection: mtu %d <= %d\n",
965 			   p->mtu, IPOIB_ENCAP_LEN);
966 		return -EINVAL;
967 	}
968 
969 	qp_attr.qp_state = IB_QPS_RTR;
970 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
971 	if (ret) {
972 		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
973 		return ret;
974 	}
975 
976 	qp_attr.rq_psn = 0 /* FIXME */;
977 	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
978 	if (ret) {
979 		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
980 		return ret;
981 	}
982 
983 	qp_attr.qp_state = IB_QPS_RTS;
984 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
985 	if (ret) {
986 		ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret);
987 		return ret;
988 	}
989 	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
990 	if (ret) {
991 		ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret);
992 		return ret;
993 	}
994 
995 	skb_queue_head_init(&skqueue);
996 
997 	spin_lock_irq(&priv->lock);
998 	set_bit(IPOIB_FLAG_OPER_UP, &p->flags);
999 	if (p->neigh)
1000 		while ((skb = __skb_dequeue(&p->neigh->queue)))
1001 			__skb_queue_tail(&skqueue, skb);
1002 	spin_unlock_irq(&priv->lock);
1003 
1004 	while ((skb = __skb_dequeue(&skqueue))) {
1005 		skb->dev = p->dev;
1006 		if (dev_queue_xmit(skb))
1007 			ipoib_warn(priv, "dev_queue_xmit failed "
1008 				   "to requeue packet\n");
1009 	}
1010 
1011 	ret = ib_send_cm_rtu(cm_id, NULL, 0);
1012 	if (ret) {
1013 		ipoib_warn(priv, "failed to send RTU: %d\n", ret);
1014 		return ret;
1015 	}
1016 	return 0;
1017 }
1018 
1019 static struct ib_qp *ipoib_cm_create_tx_qp(struct net_device *dev, struct ipoib_cm_tx *tx)
1020 {
1021 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1022 	struct ib_qp_init_attr attr = {
1023 		.send_cq		= priv->recv_cq,
1024 		.recv_cq		= priv->recv_cq,
1025 		.srq			= priv->cm.srq,
1026 		.cap.max_send_wr	= ipoib_sendq_size,
1027 		.cap.max_send_sge	= 1,
1028 		.sq_sig_type		= IB_SIGNAL_ALL_WR,
1029 		.qp_type		= IB_QPT_RC,
1030 		.qp_context		= tx
1031 	};
1032 
1033 	return ib_create_qp(priv->pd, &attr);
1034 }
1035 
1036 static int ipoib_cm_send_req(struct net_device *dev,
1037 			     struct ib_cm_id *id, struct ib_qp *qp,
1038 			     u32 qpn,
1039 			     struct ib_sa_path_rec *pathrec)
1040 {
1041 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1042 	struct ipoib_cm_data data = {};
1043 	struct ib_cm_req_param req = {};
1044 
1045 	data.qpn = cpu_to_be32(priv->qp->qp_num);
1046 	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
1047 
1048 	req.primary_path		= pathrec;
1049 	req.alternate_path		= NULL;
1050 	req.service_id			= cpu_to_be64(IPOIB_CM_IETF_ID | qpn);
1051 	req.qp_num			= qp->qp_num;
1052 	req.qp_type			= qp->qp_type;
1053 	req.private_data		= &data;
1054 	req.private_data_len		= sizeof data;
1055 	req.flow_control		= 0;
1056 
1057 	req.starting_psn		= 0; /* FIXME */
1058 
1059 	/*
1060 	 * Pick some arbitrary defaults here; we could make these
1061 	 * module parameters if anyone cared about setting them.
1062 	 */
1063 	req.responder_resources		= 4;
1064 	req.remote_cm_response_timeout	= 20;
1065 	req.local_cm_response_timeout	= 20;
1066 	req.retry_count			= 0; /* RFC draft warns against retries */
1067 	req.rnr_retry_count		= 0; /* RFC draft warns against retries */
1068 	req.max_cm_retries		= 15;
1069 	req.srq				= ipoib_cm_has_srq(dev);
1070 	return ib_send_cm_req(id, &req);
1071 }
1072 
1073 static int ipoib_cm_modify_tx_init(struct net_device *dev,
1074 				  struct ib_cm_id *cm_id, struct ib_qp *qp)
1075 {
1076 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1077 	struct ib_qp_attr qp_attr;
1078 	int qp_attr_mask, ret;
1079 	ret = ib_find_pkey(priv->ca, priv->port, priv->pkey, &qp_attr.pkey_index);
1080 	if (ret) {
1081 		ipoib_warn(priv, "pkey 0x%x not found: %d\n", priv->pkey, ret);
1082 		return ret;
1083 	}
1084 
1085 	qp_attr.qp_state = IB_QPS_INIT;
1086 	qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE;
1087 	qp_attr.port_num = priv->port;
1088 	qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PKEY_INDEX | IB_QP_PORT;
1089 
1090 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
1091 	if (ret) {
1092 		ipoib_warn(priv, "failed to modify tx QP to INIT: %d\n", ret);
1093 		return ret;
1094 	}
1095 	return 0;
1096 }
1097 
1098 static int ipoib_cm_tx_init(struct ipoib_cm_tx *p, u32 qpn,
1099 			    struct ib_sa_path_rec *pathrec)
1100 {
1101 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
1102 	int ret;
1103 
1104 	p->tx_ring = vzalloc(ipoib_sendq_size * sizeof *p->tx_ring);
1105 	if (!p->tx_ring) {
1106 		ipoib_warn(priv, "failed to allocate tx ring\n");
1107 		ret = -ENOMEM;
1108 		goto err_tx;
1109 	}
1110 
1111 	p->qp = ipoib_cm_create_tx_qp(p->dev, p);
1112 	if (IS_ERR(p->qp)) {
1113 		ret = PTR_ERR(p->qp);
1114 		ipoib_warn(priv, "failed to allocate tx qp: %d\n", ret);
1115 		goto err_qp;
1116 	}
1117 
1118 	p->id = ib_create_cm_id(priv->ca, ipoib_cm_tx_handler, p);
1119 	if (IS_ERR(p->id)) {
1120 		ret = PTR_ERR(p->id);
1121 		ipoib_warn(priv, "failed to create tx cm id: %d\n", ret);
1122 		goto err_id;
1123 	}
1124 
1125 	ret = ipoib_cm_modify_tx_init(p->dev, p->id,  p->qp);
1126 	if (ret) {
1127 		ipoib_warn(priv, "failed to modify tx qp to rtr: %d\n", ret);
1128 		goto err_modify;
1129 	}
1130 
1131 	ret = ipoib_cm_send_req(p->dev, p->id, p->qp, qpn, pathrec);
1132 	if (ret) {
1133 		ipoib_warn(priv, "failed to send cm req: %d\n", ret);
1134 		goto err_send_cm;
1135 	}
1136 
1137 	ipoib_dbg(priv, "Request connection 0x%x for gid %pI6 qpn 0x%x\n",
1138 		  p->qp->qp_num, pathrec->dgid.raw, qpn);
1139 
1140 	return 0;
1141 
1142 err_send_cm:
1143 err_modify:
1144 	ib_destroy_cm_id(p->id);
1145 err_id:
1146 	p->id = NULL;
1147 	ib_destroy_qp(p->qp);
1148 err_qp:
1149 	p->qp = NULL;
1150 	vfree(p->tx_ring);
1151 err_tx:
1152 	return ret;
1153 }
1154 
1155 static void ipoib_cm_tx_destroy(struct ipoib_cm_tx *p)
1156 {
1157 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
1158 	struct ipoib_cm_tx_buf *tx_req;
1159 	unsigned long begin;
1160 
1161 	ipoib_dbg(priv, "Destroy active connection 0x%x head 0x%x tail 0x%x\n",
1162 		  p->qp ? p->qp->qp_num : 0, p->tx_head, p->tx_tail);
1163 
1164 	if (p->id)
1165 		ib_destroy_cm_id(p->id);
1166 
1167 	if (p->tx_ring) {
1168 		/* Wait for all sends to complete */
1169 		begin = jiffies;
1170 		while ((int) p->tx_tail - (int) p->tx_head < 0) {
1171 			if (time_after(jiffies, begin + 5 * HZ)) {
1172 				ipoib_warn(priv, "timing out; %d sends not completed\n",
1173 					   p->tx_head - p->tx_tail);
1174 				goto timeout;
1175 			}
1176 
1177 			msleep(1);
1178 		}
1179 	}
1180 
1181 timeout:
1182 
1183 	while ((int) p->tx_tail - (int) p->tx_head < 0) {
1184 		tx_req = &p->tx_ring[p->tx_tail & (ipoib_sendq_size - 1)];
1185 		ib_dma_unmap_single(priv->ca, tx_req->mapping, tx_req->skb->len,
1186 				    DMA_TO_DEVICE);
1187 		dev_kfree_skb_any(tx_req->skb);
1188 		++p->tx_tail;
1189 		netif_tx_lock_bh(p->dev);
1190 		if (unlikely(--priv->tx_outstanding == ipoib_sendq_size >> 1) &&
1191 		    netif_queue_stopped(p->dev) &&
1192 		    test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
1193 			netif_wake_queue(p->dev);
1194 		netif_tx_unlock_bh(p->dev);
1195 	}
1196 
1197 	if (p->qp)
1198 		ib_destroy_qp(p->qp);
1199 
1200 	vfree(p->tx_ring);
1201 	kfree(p);
1202 }
1203 
1204 static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
1205 			       struct ib_cm_event *event)
1206 {
1207 	struct ipoib_cm_tx *tx = cm_id->context;
1208 	struct ipoib_dev_priv *priv = netdev_priv(tx->dev);
1209 	struct net_device *dev = priv->dev;
1210 	struct ipoib_neigh *neigh;
1211 	unsigned long flags;
1212 	int ret;
1213 
1214 	switch (event->event) {
1215 	case IB_CM_DREQ_RECEIVED:
1216 		ipoib_dbg(priv, "DREQ received.\n");
1217 		ib_send_cm_drep(cm_id, NULL, 0);
1218 		break;
1219 	case IB_CM_REP_RECEIVED:
1220 		ipoib_dbg(priv, "REP received.\n");
1221 		ret = ipoib_cm_rep_handler(cm_id, event);
1222 		if (ret)
1223 			ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,
1224 				       NULL, 0, NULL, 0);
1225 		break;
1226 	case IB_CM_REQ_ERROR:
1227 	case IB_CM_REJ_RECEIVED:
1228 	case IB_CM_TIMEWAIT_EXIT:
1229 		ipoib_dbg(priv, "CM error %d.\n", event->event);
1230 		netif_tx_lock_bh(dev);
1231 		spin_lock_irqsave(&priv->lock, flags);
1232 		neigh = tx->neigh;
1233 
1234 		if (neigh) {
1235 			neigh->cm = NULL;
1236 			ipoib_neigh_free(neigh);
1237 
1238 			tx->neigh = NULL;
1239 		}
1240 
1241 		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
1242 			list_move(&tx->list, &priv->cm.reap_list);
1243 			queue_work(ipoib_workqueue, &priv->cm.reap_task);
1244 		}
1245 
1246 		spin_unlock_irqrestore(&priv->lock, flags);
1247 		netif_tx_unlock_bh(dev);
1248 		break;
1249 	default:
1250 		break;
1251 	}
1252 
1253 	return 0;
1254 }
1255 
1256 struct ipoib_cm_tx *ipoib_cm_create_tx(struct net_device *dev, struct ipoib_path *path,
1257 				       struct ipoib_neigh *neigh)
1258 {
1259 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1260 	struct ipoib_cm_tx *tx;
1261 
1262 	tx = kzalloc(sizeof *tx, GFP_ATOMIC);
1263 	if (!tx)
1264 		return NULL;
1265 
1266 	neigh->cm = tx;
1267 	tx->neigh = neigh;
1268 	tx->path = path;
1269 	tx->dev = dev;
1270 	list_add(&tx->list, &priv->cm.start_list);
1271 	set_bit(IPOIB_FLAG_INITIALIZED, &tx->flags);
1272 	queue_work(ipoib_workqueue, &priv->cm.start_task);
1273 	return tx;
1274 }
1275 
1276 void ipoib_cm_destroy_tx(struct ipoib_cm_tx *tx)
1277 {
1278 	struct ipoib_dev_priv *priv = netdev_priv(tx->dev);
1279 	unsigned long flags;
1280 	if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
1281 		spin_lock_irqsave(&priv->lock, flags);
1282 		list_move(&tx->list, &priv->cm.reap_list);
1283 		queue_work(ipoib_workqueue, &priv->cm.reap_task);
1284 		ipoib_dbg(priv, "Reap connection for gid %pI6\n",
1285 			  tx->neigh->daddr + 4);
1286 		tx->neigh = NULL;
1287 		spin_unlock_irqrestore(&priv->lock, flags);
1288 	}
1289 }
1290 
1291 static void ipoib_cm_tx_start(struct work_struct *work)
1292 {
1293 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1294 						   cm.start_task);
1295 	struct net_device *dev = priv->dev;
1296 	struct ipoib_neigh *neigh;
1297 	struct ipoib_cm_tx *p;
1298 	unsigned long flags;
1299 	int ret;
1300 
1301 	struct ib_sa_path_rec pathrec;
1302 	u32 qpn;
1303 
1304 	netif_tx_lock_bh(dev);
1305 	spin_lock_irqsave(&priv->lock, flags);
1306 
1307 	while (!list_empty(&priv->cm.start_list)) {
1308 		p = list_entry(priv->cm.start_list.next, typeof(*p), list);
1309 		list_del_init(&p->list);
1310 		neigh = p->neigh;
1311 		qpn = IPOIB_QPN(neigh->daddr);
1312 		memcpy(&pathrec, &p->path->pathrec, sizeof pathrec);
1313 
1314 		spin_unlock_irqrestore(&priv->lock, flags);
1315 		netif_tx_unlock_bh(dev);
1316 
1317 		ret = ipoib_cm_tx_init(p, qpn, &pathrec);
1318 
1319 		netif_tx_lock_bh(dev);
1320 		spin_lock_irqsave(&priv->lock, flags);
1321 
1322 		if (ret) {
1323 			neigh = p->neigh;
1324 			if (neigh) {
1325 				neigh->cm = NULL;
1326 				ipoib_neigh_free(neigh);
1327 			}
1328 			list_del(&p->list);
1329 			kfree(p);
1330 		}
1331 	}
1332 
1333 	spin_unlock_irqrestore(&priv->lock, flags);
1334 	netif_tx_unlock_bh(dev);
1335 }
1336 
1337 static void ipoib_cm_tx_reap(struct work_struct *work)
1338 {
1339 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1340 						   cm.reap_task);
1341 	struct net_device *dev = priv->dev;
1342 	struct ipoib_cm_tx *p;
1343 	unsigned long flags;
1344 
1345 	netif_tx_lock_bh(dev);
1346 	spin_lock_irqsave(&priv->lock, flags);
1347 
1348 	while (!list_empty(&priv->cm.reap_list)) {
1349 		p = list_entry(priv->cm.reap_list.next, typeof(*p), list);
1350 		list_del(&p->list);
1351 		spin_unlock_irqrestore(&priv->lock, flags);
1352 		netif_tx_unlock_bh(dev);
1353 		ipoib_cm_tx_destroy(p);
1354 		netif_tx_lock_bh(dev);
1355 		spin_lock_irqsave(&priv->lock, flags);
1356 	}
1357 
1358 	spin_unlock_irqrestore(&priv->lock, flags);
1359 	netif_tx_unlock_bh(dev);
1360 }
1361 
1362 static void ipoib_cm_skb_reap(struct work_struct *work)
1363 {
1364 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1365 						   cm.skb_task);
1366 	struct net_device *dev = priv->dev;
1367 	struct sk_buff *skb;
1368 	unsigned long flags;
1369 	unsigned mtu = priv->mcast_mtu;
1370 
1371 	netif_tx_lock_bh(dev);
1372 	spin_lock_irqsave(&priv->lock, flags);
1373 
1374 	while ((skb = skb_dequeue(&priv->cm.skb_queue))) {
1375 		spin_unlock_irqrestore(&priv->lock, flags);
1376 		netif_tx_unlock_bh(dev);
1377 
1378 		if (skb->protocol == htons(ETH_P_IP))
1379 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
1380 #if IS_ENABLED(CONFIG_IPV6)
1381 		else if (skb->protocol == htons(ETH_P_IPV6))
1382 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1383 #endif
1384 		dev_kfree_skb_any(skb);
1385 
1386 		netif_tx_lock_bh(dev);
1387 		spin_lock_irqsave(&priv->lock, flags);
1388 	}
1389 
1390 	spin_unlock_irqrestore(&priv->lock, flags);
1391 	netif_tx_unlock_bh(dev);
1392 }
1393 
1394 void ipoib_cm_skb_too_long(struct net_device *dev, struct sk_buff *skb,
1395 			   unsigned int mtu)
1396 {
1397 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1398 	int e = skb_queue_empty(&priv->cm.skb_queue);
1399 
1400 	if (skb_dst(skb))
1401 		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1402 
1403 	skb_queue_tail(&priv->cm.skb_queue, skb);
1404 	if (e)
1405 		queue_work(ipoib_workqueue, &priv->cm.skb_task);
1406 }
1407 
1408 static void ipoib_cm_rx_reap(struct work_struct *work)
1409 {
1410 	ipoib_cm_free_rx_reap_list(container_of(work, struct ipoib_dev_priv,
1411 						cm.rx_reap_task)->dev);
1412 }
1413 
1414 static void ipoib_cm_stale_task(struct work_struct *work)
1415 {
1416 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1417 						   cm.stale_task.work);
1418 	struct ipoib_cm_rx *p;
1419 	int ret;
1420 
1421 	spin_lock_irq(&priv->lock);
1422 	while (!list_empty(&priv->cm.passive_ids)) {
1423 		/* List is sorted by LRU, start from tail,
1424 		 * stop when we see a recently used entry */
1425 		p = list_entry(priv->cm.passive_ids.prev, typeof(*p), list);
1426 		if (time_before_eq(jiffies, p->jiffies + IPOIB_CM_RX_TIMEOUT))
1427 			break;
1428 		list_move(&p->list, &priv->cm.rx_error_list);
1429 		p->state = IPOIB_CM_RX_ERROR;
1430 		spin_unlock_irq(&priv->lock);
1431 		ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
1432 		if (ret)
1433 			ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
1434 		spin_lock_irq(&priv->lock);
1435 	}
1436 
1437 	if (!list_empty(&priv->cm.passive_ids))
1438 		queue_delayed_work(ipoib_workqueue,
1439 				   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
1440 	spin_unlock_irq(&priv->lock);
1441 }
1442 
1443 
1444 static ssize_t show_mode(struct device *d, struct device_attribute *attr,
1445 			 char *buf)
1446 {
1447 	struct ipoib_dev_priv *priv = netdev_priv(to_net_dev(d));
1448 
1449 	if (test_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags))
1450 		return sprintf(buf, "connected\n");
1451 	else
1452 		return sprintf(buf, "datagram\n");
1453 }
1454 
1455 static ssize_t set_mode(struct device *d, struct device_attribute *attr,
1456 			const char *buf, size_t count)
1457 {
1458 	struct net_device *dev = to_net_dev(d);
1459 	int ret;
1460 
1461 	if (!rtnl_trylock())
1462 		return restart_syscall();
1463 
1464 	ret = ipoib_set_mode(dev, buf);
1465 
1466 	rtnl_unlock();
1467 
1468 	if (!ret)
1469 		return count;
1470 
1471 	return ret;
1472 }
1473 
1474 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, show_mode, set_mode);
1475 
1476 int ipoib_cm_add_mode_attr(struct net_device *dev)
1477 {
1478 	return device_create_file(&dev->dev, &dev_attr_mode);
1479 }
1480 
1481 static void ipoib_cm_create_srq(struct net_device *dev, int max_sge)
1482 {
1483 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1484 	struct ib_srq_init_attr srq_init_attr = {
1485 		.srq_type = IB_SRQT_BASIC,
1486 		.attr = {
1487 			.max_wr  = ipoib_recvq_size,
1488 			.max_sge = max_sge
1489 		}
1490 	};
1491 
1492 	priv->cm.srq = ib_create_srq(priv->pd, &srq_init_attr);
1493 	if (IS_ERR(priv->cm.srq)) {
1494 		if (PTR_ERR(priv->cm.srq) != -ENOSYS)
1495 			printk(KERN_WARNING "%s: failed to allocate SRQ, error %ld\n",
1496 			       priv->ca->name, PTR_ERR(priv->cm.srq));
1497 		priv->cm.srq = NULL;
1498 		return;
1499 	}
1500 
1501 	priv->cm.srq_ring = vzalloc(ipoib_recvq_size * sizeof *priv->cm.srq_ring);
1502 	if (!priv->cm.srq_ring) {
1503 		printk(KERN_WARNING "%s: failed to allocate CM SRQ ring (%d entries)\n",
1504 		       priv->ca->name, ipoib_recvq_size);
1505 		ib_destroy_srq(priv->cm.srq);
1506 		priv->cm.srq = NULL;
1507 		return;
1508 	}
1509 
1510 }
1511 
1512 int ipoib_cm_dev_init(struct net_device *dev)
1513 {
1514 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1515 	int i, ret;
1516 	struct ib_device_attr attr;
1517 
1518 	INIT_LIST_HEAD(&priv->cm.passive_ids);
1519 	INIT_LIST_HEAD(&priv->cm.reap_list);
1520 	INIT_LIST_HEAD(&priv->cm.start_list);
1521 	INIT_LIST_HEAD(&priv->cm.rx_error_list);
1522 	INIT_LIST_HEAD(&priv->cm.rx_flush_list);
1523 	INIT_LIST_HEAD(&priv->cm.rx_drain_list);
1524 	INIT_LIST_HEAD(&priv->cm.rx_reap_list);
1525 	INIT_WORK(&priv->cm.start_task, ipoib_cm_tx_start);
1526 	INIT_WORK(&priv->cm.reap_task, ipoib_cm_tx_reap);
1527 	INIT_WORK(&priv->cm.skb_task, ipoib_cm_skb_reap);
1528 	INIT_WORK(&priv->cm.rx_reap_task, ipoib_cm_rx_reap);
1529 	INIT_DELAYED_WORK(&priv->cm.stale_task, ipoib_cm_stale_task);
1530 
1531 	skb_queue_head_init(&priv->cm.skb_queue);
1532 
1533 	ret = ib_query_device(priv->ca, &attr);
1534 	if (ret) {
1535 		printk(KERN_WARNING "ib_query_device() failed with %d\n", ret);
1536 		return ret;
1537 	}
1538 
1539 	ipoib_dbg(priv, "max_srq_sge=%d\n", attr.max_srq_sge);
1540 
1541 	attr.max_srq_sge = min_t(int, IPOIB_CM_RX_SG, attr.max_srq_sge);
1542 	ipoib_cm_create_srq(dev, attr.max_srq_sge);
1543 	if (ipoib_cm_has_srq(dev)) {
1544 		priv->cm.max_cm_mtu = attr.max_srq_sge * PAGE_SIZE - 0x10;
1545 		priv->cm.num_frags  = attr.max_srq_sge;
1546 		ipoib_dbg(priv, "max_cm_mtu = 0x%x, num_frags=%d\n",
1547 			  priv->cm.max_cm_mtu, priv->cm.num_frags);
1548 	} else {
1549 		priv->cm.max_cm_mtu = IPOIB_CM_MTU;
1550 		priv->cm.num_frags  = IPOIB_CM_RX_SG;
1551 	}
1552 
1553 	ipoib_cm_init_rx_wr(dev, &priv->cm.rx_wr, priv->cm.rx_sge);
1554 
1555 	if (ipoib_cm_has_srq(dev)) {
1556 		for (i = 0; i < ipoib_recvq_size; ++i) {
1557 			if (!ipoib_cm_alloc_rx_skb(dev, priv->cm.srq_ring, i,
1558 						   priv->cm.num_frags - 1,
1559 						   priv->cm.srq_ring[i].mapping)) {
1560 				ipoib_warn(priv, "failed to allocate "
1561 					   "receive buffer %d\n", i);
1562 				ipoib_cm_dev_cleanup(dev);
1563 				return -ENOMEM;
1564 			}
1565 
1566 			if (ipoib_cm_post_receive_srq(dev, i)) {
1567 				ipoib_warn(priv, "ipoib_cm_post_receive_srq "
1568 					   "failed for buf %d\n", i);
1569 				ipoib_cm_dev_cleanup(dev);
1570 				return -EIO;
1571 			}
1572 		}
1573 	}
1574 
1575 	priv->dev->dev_addr[0] = IPOIB_FLAGS_RC;
1576 	return 0;
1577 }
1578 
1579 void ipoib_cm_dev_cleanup(struct net_device *dev)
1580 {
1581 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1582 	int ret;
1583 
1584 	if (!priv->cm.srq)
1585 		return;
1586 
1587 	ipoib_dbg(priv, "Cleanup ipoib connected mode.\n");
1588 
1589 	ret = ib_destroy_srq(priv->cm.srq);
1590 	if (ret)
1591 		ipoib_warn(priv, "ib_destroy_srq failed: %d\n", ret);
1592 
1593 	priv->cm.srq = NULL;
1594 	if (!priv->cm.srq_ring)
1595 		return;
1596 
1597 	ipoib_cm_free_rx_ring(dev, priv->cm.srq_ring);
1598 	priv->cm.srq_ring = NULL;
1599 }
1600