xref: /linux/drivers/infiniband/ulp/ipoib/ipoib_cm.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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  * $Id$
33  */
34 
35 #include <rdma/ib_cm.h>
36 #include <rdma/ib_cache.h>
37 #include <net/dst.h>
38 #include <net/icmp.h>
39 #include <linux/icmpv6.h>
40 
41 #ifdef CONFIG_INFINIBAND_IPOIB_DEBUG_DATA
42 static int data_debug_level;
43 
44 module_param_named(cm_data_debug_level, data_debug_level, int, 0644);
45 MODULE_PARM_DESC(cm_data_debug_level,
46 		 "Enable data path debug tracing for connected mode if > 0");
47 #endif
48 
49 #include "ipoib.h"
50 
51 #define IPOIB_CM_IETF_ID 0x1000000000000000ULL
52 
53 #define IPOIB_CM_RX_UPDATE_TIME (256 * HZ)
54 #define IPOIB_CM_RX_TIMEOUT     (2 * 256 * HZ)
55 #define IPOIB_CM_RX_DELAY       (3 * 256 * HZ)
56 #define IPOIB_CM_RX_UPDATE_MASK (0x3)
57 
58 struct ipoib_cm_id {
59 	struct ib_cm_id *id;
60 	int flags;
61 	u32 remote_qpn;
62 	u32 remote_mtu;
63 };
64 
65 static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
66 			       struct ib_cm_event *event);
67 
68 static void ipoib_cm_dma_unmap_rx(struct ipoib_dev_priv *priv, int frags,
69 				  u64 mapping[IPOIB_CM_RX_SG])
70 {
71 	int i;
72 
73 	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
74 
75 	for (i = 0; i < frags; ++i)
76 		ib_dma_unmap_single(priv->ca, mapping[i + 1], PAGE_SIZE, DMA_FROM_DEVICE);
77 }
78 
79 static int ipoib_cm_post_receive(struct net_device *dev, int id)
80 {
81 	struct ipoib_dev_priv *priv = netdev_priv(dev);
82 	struct ib_recv_wr *bad_wr;
83 	int i, ret;
84 
85 	priv->cm.rx_wr.wr_id = id | IPOIB_CM_OP_SRQ;
86 
87 	for (i = 0; i < IPOIB_CM_RX_SG; ++i)
88 		priv->cm.rx_sge[i].addr = priv->cm.srq_ring[id].mapping[i];
89 
90 	ret = ib_post_srq_recv(priv->cm.srq, &priv->cm.rx_wr, &bad_wr);
91 	if (unlikely(ret)) {
92 		ipoib_warn(priv, "post srq failed for buf %d (%d)\n", id, ret);
93 		ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
94 				      priv->cm.srq_ring[id].mapping);
95 		dev_kfree_skb_any(priv->cm.srq_ring[id].skb);
96 		priv->cm.srq_ring[id].skb = NULL;
97 	}
98 
99 	return ret;
100 }
101 
102 static struct sk_buff *ipoib_cm_alloc_rx_skb(struct net_device *dev, int id, int frags,
103 					     u64 mapping[IPOIB_CM_RX_SG])
104 {
105 	struct ipoib_dev_priv *priv = netdev_priv(dev);
106 	struct sk_buff *skb;
107 	int i;
108 
109 	skb = dev_alloc_skb(IPOIB_CM_HEAD_SIZE + 12);
110 	if (unlikely(!skb))
111 		return NULL;
112 
113 	/*
114 	 * IPoIB adds a 4 byte header. So we need 12 more bytes to align the
115 	 * IP header to a multiple of 16.
116 	 */
117 	skb_reserve(skb, 12);
118 
119 	mapping[0] = ib_dma_map_single(priv->ca, skb->data, IPOIB_CM_HEAD_SIZE,
120 				       DMA_FROM_DEVICE);
121 	if (unlikely(ib_dma_mapping_error(priv->ca, mapping[0]))) {
122 		dev_kfree_skb_any(skb);
123 		return NULL;
124 	}
125 
126 	for (i = 0; i < frags; i++) {
127 		struct page *page = alloc_page(GFP_ATOMIC);
128 
129 		if (!page)
130 			goto partial_error;
131 		skb_fill_page_desc(skb, i, page, 0, PAGE_SIZE);
132 
133 		mapping[i + 1] = ib_dma_map_page(priv->ca, skb_shinfo(skb)->frags[i].page,
134 						 0, PAGE_SIZE, DMA_TO_DEVICE);
135 		if (unlikely(ib_dma_mapping_error(priv->ca, mapping[i + 1])))
136 			goto partial_error;
137 	}
138 
139 	priv->cm.srq_ring[id].skb = skb;
140 	return skb;
141 
142 partial_error:
143 
144 	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
145 
146 	for (; i >= 0; --i)
147 		ib_dma_unmap_single(priv->ca, mapping[i + 1], PAGE_SIZE, DMA_FROM_DEVICE);
148 
149 	dev_kfree_skb_any(skb);
150 	return NULL;
151 }
152 
153 static struct ib_qp *ipoib_cm_create_rx_qp(struct net_device *dev,
154 					   struct ipoib_cm_rx *p)
155 {
156 	struct ipoib_dev_priv *priv = netdev_priv(dev);
157 	struct ib_qp_init_attr attr = {
158 		.send_cq = priv->cq, /* does not matter, we never send anything */
159 		.recv_cq = priv->cq,
160 		.srq = priv->cm.srq,
161 		.cap.max_send_wr = 1, /* FIXME: 0 Seems not to work */
162 		.cap.max_send_sge = 1, /* FIXME: 0 Seems not to work */
163 		.sq_sig_type = IB_SIGNAL_ALL_WR,
164 		.qp_type = IB_QPT_RC,
165 		.qp_context = p,
166 	};
167 	return ib_create_qp(priv->pd, &attr);
168 }
169 
170 static int ipoib_cm_modify_rx_qp(struct net_device *dev,
171 				  struct ib_cm_id *cm_id, struct ib_qp *qp,
172 				  unsigned psn)
173 {
174 	struct ipoib_dev_priv *priv = netdev_priv(dev);
175 	struct ib_qp_attr qp_attr;
176 	int qp_attr_mask, ret;
177 
178 	qp_attr.qp_state = IB_QPS_INIT;
179 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
180 	if (ret) {
181 		ipoib_warn(priv, "failed to init QP attr for INIT: %d\n", ret);
182 		return ret;
183 	}
184 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
185 	if (ret) {
186 		ipoib_warn(priv, "failed to modify QP to INIT: %d\n", ret);
187 		return ret;
188 	}
189 	qp_attr.qp_state = IB_QPS_RTR;
190 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
191 	if (ret) {
192 		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
193 		return ret;
194 	}
195 	qp_attr.rq_psn = psn;
196 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
197 	if (ret) {
198 		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
199 		return ret;
200 	}
201 	return 0;
202 }
203 
204 static int ipoib_cm_send_rep(struct net_device *dev, struct ib_cm_id *cm_id,
205 			     struct ib_qp *qp, struct ib_cm_req_event_param *req,
206 			     unsigned psn)
207 {
208 	struct ipoib_dev_priv *priv = netdev_priv(dev);
209 	struct ipoib_cm_data data = {};
210 	struct ib_cm_rep_param rep = {};
211 
212 	data.qpn = cpu_to_be32(priv->qp->qp_num);
213 	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
214 
215 	rep.private_data = &data;
216 	rep.private_data_len = sizeof data;
217 	rep.flow_control = 0;
218 	rep.rnr_retry_count = req->rnr_retry_count;
219 	rep.target_ack_delay = 20; /* FIXME */
220 	rep.srq = 1;
221 	rep.qp_num = qp->qp_num;
222 	rep.starting_psn = psn;
223 	return ib_send_cm_rep(cm_id, &rep);
224 }
225 
226 static int ipoib_cm_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
227 {
228 	struct net_device *dev = cm_id->context;
229 	struct ipoib_dev_priv *priv = netdev_priv(dev);
230 	struct ipoib_cm_rx *p;
231 	unsigned long flags;
232 	unsigned psn;
233 	int ret;
234 
235 	ipoib_dbg(priv, "REQ arrived\n");
236 	p = kzalloc(sizeof *p, GFP_KERNEL);
237 	if (!p)
238 		return -ENOMEM;
239 	p->dev = dev;
240 	p->id = cm_id;
241 	p->qp = ipoib_cm_create_rx_qp(dev, p);
242 	if (IS_ERR(p->qp)) {
243 		ret = PTR_ERR(p->qp);
244 		goto err_qp;
245 	}
246 
247 	psn = random32() & 0xffffff;
248 	ret = ipoib_cm_modify_rx_qp(dev, cm_id, p->qp, psn);
249 	if (ret)
250 		goto err_modify;
251 
252 	ret = ipoib_cm_send_rep(dev, cm_id, p->qp, &event->param.req_rcvd, psn);
253 	if (ret) {
254 		ipoib_warn(priv, "failed to send REP: %d\n", ret);
255 		goto err_rep;
256 	}
257 
258 	cm_id->context = p;
259 	p->jiffies = jiffies;
260 	spin_lock_irqsave(&priv->lock, flags);
261 	list_add(&p->list, &priv->cm.passive_ids);
262 	spin_unlock_irqrestore(&priv->lock, flags);
263 	queue_delayed_work(ipoib_workqueue,
264 			   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
265 	return 0;
266 
267 err_rep:
268 err_modify:
269 	ib_destroy_qp(p->qp);
270 err_qp:
271 	kfree(p);
272 	return ret;
273 }
274 
275 static int ipoib_cm_rx_handler(struct ib_cm_id *cm_id,
276 			       struct ib_cm_event *event)
277 {
278 	struct ipoib_cm_rx *p;
279 	struct ipoib_dev_priv *priv;
280 	unsigned long flags;
281 	int ret;
282 
283 	switch (event->event) {
284 	case IB_CM_REQ_RECEIVED:
285 		return ipoib_cm_req_handler(cm_id, event);
286 	case IB_CM_DREQ_RECEIVED:
287 		p = cm_id->context;
288 		ib_send_cm_drep(cm_id, NULL, 0);
289 		/* Fall through */
290 	case IB_CM_REJ_RECEIVED:
291 		p = cm_id->context;
292 		priv = netdev_priv(p->dev);
293 		spin_lock_irqsave(&priv->lock, flags);
294 		if (list_empty(&p->list))
295 			ret = 0; /* Connection is going away already. */
296 		else {
297 			list_del_init(&p->list);
298 			ret = -ECONNRESET;
299 		}
300 		spin_unlock_irqrestore(&priv->lock, flags);
301 		if (ret) {
302 			ib_destroy_qp(p->qp);
303 			kfree(p);
304 			return ret;
305 		}
306 		return 0;
307 	default:
308 		return 0;
309 	}
310 }
311 /* Adjust length of skb with fragments to match received data */
312 static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space,
313 			  unsigned int length, struct sk_buff *toskb)
314 {
315 	int i, num_frags;
316 	unsigned int size;
317 
318 	/* put header into skb */
319 	size = min(length, hdr_space);
320 	skb->tail += size;
321 	skb->len += size;
322 	length -= size;
323 
324 	num_frags = skb_shinfo(skb)->nr_frags;
325 	for (i = 0; i < num_frags; i++) {
326 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
327 
328 		if (length == 0) {
329 			/* don't need this page */
330 			skb_fill_page_desc(toskb, i, frag->page, 0, PAGE_SIZE);
331 			--skb_shinfo(skb)->nr_frags;
332 		} else {
333 			size = min(length, (unsigned) PAGE_SIZE);
334 
335 			frag->size = size;
336 			skb->data_len += size;
337 			skb->truesize += size;
338 			skb->len += size;
339 			length -= size;
340 		}
341 	}
342 }
343 
344 void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
345 {
346 	struct ipoib_dev_priv *priv = netdev_priv(dev);
347 	unsigned int wr_id = wc->wr_id & ~IPOIB_CM_OP_SRQ;
348 	struct sk_buff *skb, *newskb;
349 	struct ipoib_cm_rx *p;
350 	unsigned long flags;
351 	u64 mapping[IPOIB_CM_RX_SG];
352 	int frags;
353 
354 	ipoib_dbg_data(priv, "cm recv completion: id %d, op %d, status: %d\n",
355 		       wr_id, wc->opcode, wc->status);
356 
357 	if (unlikely(wr_id >= ipoib_recvq_size)) {
358 		ipoib_warn(priv, "cm recv completion event with wrid %d (> %d)\n",
359 			   wr_id, ipoib_recvq_size);
360 		return;
361 	}
362 
363 	skb  = priv->cm.srq_ring[wr_id].skb;
364 
365 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
366 		ipoib_dbg(priv, "cm recv error "
367 			   "(status=%d, wrid=%d vend_err %x)\n",
368 			   wc->status, wr_id, wc->vendor_err);
369 		++priv->stats.rx_dropped;
370 		goto repost;
371 	}
372 
373 	if (!likely(wr_id & IPOIB_CM_RX_UPDATE_MASK)) {
374 		p = wc->qp->qp_context;
375 		if (time_after_eq(jiffies, p->jiffies + IPOIB_CM_RX_UPDATE_TIME)) {
376 			spin_lock_irqsave(&priv->lock, flags);
377 			p->jiffies = jiffies;
378 			/* Move this entry to list head, but do
379 			 * not re-add it if it has been removed. */
380 			if (!list_empty(&p->list))
381 				list_move(&p->list, &priv->cm.passive_ids);
382 			spin_unlock_irqrestore(&priv->lock, flags);
383 			queue_delayed_work(ipoib_workqueue,
384 					   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
385 		}
386 	}
387 
388 	frags = PAGE_ALIGN(wc->byte_len - min(wc->byte_len,
389 					      (unsigned)IPOIB_CM_HEAD_SIZE)) / PAGE_SIZE;
390 
391 	newskb = ipoib_cm_alloc_rx_skb(dev, wr_id, frags, mapping);
392 	if (unlikely(!newskb)) {
393 		/*
394 		 * If we can't allocate a new RX buffer, dump
395 		 * this packet and reuse the old buffer.
396 		 */
397 		ipoib_dbg(priv, "failed to allocate receive buffer %d\n", wr_id);
398 		++priv->stats.rx_dropped;
399 		goto repost;
400 	}
401 
402 	ipoib_cm_dma_unmap_rx(priv, frags, priv->cm.srq_ring[wr_id].mapping);
403 	memcpy(priv->cm.srq_ring[wr_id].mapping, mapping, (frags + 1) * sizeof *mapping);
404 
405 	ipoib_dbg_data(priv, "received %d bytes, SLID 0x%04x\n",
406 		       wc->byte_len, wc->slid);
407 
408 	skb_put_frags(skb, IPOIB_CM_HEAD_SIZE, wc->byte_len, newskb);
409 
410 	skb->protocol = ((struct ipoib_header *) skb->data)->proto;
411 	skb->mac.raw = skb->data;
412 	skb_pull(skb, IPOIB_ENCAP_LEN);
413 
414 	dev->last_rx = jiffies;
415 	++priv->stats.rx_packets;
416 	priv->stats.rx_bytes += skb->len;
417 
418 	skb->dev = dev;
419 	/* XXX get correct PACKET_ type here */
420 	skb->pkt_type = PACKET_HOST;
421 	netif_rx_ni(skb);
422 
423 repost:
424 	if (unlikely(ipoib_cm_post_receive(dev, wr_id)))
425 		ipoib_warn(priv, "ipoib_cm_post_receive failed "
426 			   "for buf %d\n", wr_id);
427 }
428 
429 static inline int post_send(struct ipoib_dev_priv *priv,
430 			    struct ipoib_cm_tx *tx,
431 			    unsigned int wr_id,
432 			    u64 addr, int len)
433 {
434 	struct ib_send_wr *bad_wr;
435 
436 	priv->tx_sge.addr             = addr;
437 	priv->tx_sge.length           = len;
438 
439 	priv->tx_wr.wr_id 	      = wr_id;
440 
441 	return ib_post_send(tx->qp, &priv->tx_wr, &bad_wr);
442 }
443 
444 void ipoib_cm_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_cm_tx *tx)
445 {
446 	struct ipoib_dev_priv *priv = netdev_priv(dev);
447 	struct ipoib_tx_buf *tx_req;
448 	u64 addr;
449 
450 	if (unlikely(skb->len > tx->mtu)) {
451 		ipoib_warn(priv, "packet len %d (> %d) too long to send, dropping\n",
452 			   skb->len, tx->mtu);
453 		++priv->stats.tx_dropped;
454 		++priv->stats.tx_errors;
455 		ipoib_cm_skb_too_long(dev, skb, tx->mtu - INFINIBAND_ALEN);
456 		return;
457 	}
458 
459 	ipoib_dbg_data(priv, "sending packet: head 0x%x length %d connection 0x%x\n",
460 		       tx->tx_head, skb->len, tx->qp->qp_num);
461 
462 	/*
463 	 * We put the skb into the tx_ring _before_ we call post_send()
464 	 * because it's entirely possible that the completion handler will
465 	 * run before we execute anything after the post_send().  That
466 	 * means we have to make sure everything is properly recorded and
467 	 * our state is consistent before we call post_send().
468 	 */
469 	tx_req = &tx->tx_ring[tx->tx_head & (ipoib_sendq_size - 1)];
470 	tx_req->skb = skb;
471 	addr = ib_dma_map_single(priv->ca, skb->data, skb->len, DMA_TO_DEVICE);
472 	if (unlikely(ib_dma_mapping_error(priv->ca, addr))) {
473 		++priv->stats.tx_errors;
474 		dev_kfree_skb_any(skb);
475 		return;
476 	}
477 
478 	tx_req->mapping = addr;
479 
480 	if (unlikely(post_send(priv, tx, tx->tx_head & (ipoib_sendq_size - 1),
481 			        addr, skb->len))) {
482 		ipoib_warn(priv, "post_send failed\n");
483 		++priv->stats.tx_errors;
484 		ib_dma_unmap_single(priv->ca, addr, skb->len, DMA_TO_DEVICE);
485 		dev_kfree_skb_any(skb);
486 	} else {
487 		dev->trans_start = jiffies;
488 		++tx->tx_head;
489 
490 		if (tx->tx_head - tx->tx_tail == ipoib_sendq_size) {
491 			ipoib_dbg(priv, "TX ring 0x%x full, stopping kernel net queue\n",
492 				  tx->qp->qp_num);
493 			netif_stop_queue(dev);
494 			set_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags);
495 		}
496 	}
497 }
498 
499 static void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ipoib_cm_tx *tx,
500 				  struct ib_wc *wc)
501 {
502 	struct ipoib_dev_priv *priv = netdev_priv(dev);
503 	unsigned int wr_id = wc->wr_id;
504 	struct ipoib_tx_buf *tx_req;
505 	unsigned long flags;
506 
507 	ipoib_dbg_data(priv, "cm send completion: id %d, op %d, status: %d\n",
508 		       wr_id, wc->opcode, wc->status);
509 
510 	if (unlikely(wr_id >= ipoib_sendq_size)) {
511 		ipoib_warn(priv, "cm send completion event with wrid %d (> %d)\n",
512 			   wr_id, ipoib_sendq_size);
513 		return;
514 	}
515 
516 	tx_req = &tx->tx_ring[wr_id];
517 
518 	ib_dma_unmap_single(priv->ca, tx_req->mapping, tx_req->skb->len, DMA_TO_DEVICE);
519 
520 	/* FIXME: is this right? Shouldn't we only increment on success? */
521 	++priv->stats.tx_packets;
522 	priv->stats.tx_bytes += tx_req->skb->len;
523 
524 	dev_kfree_skb_any(tx_req->skb);
525 
526 	spin_lock_irqsave(&priv->tx_lock, flags);
527 	++tx->tx_tail;
528 	if (unlikely(test_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags)) &&
529 	    tx->tx_head - tx->tx_tail <= ipoib_sendq_size >> 1) {
530 		clear_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags);
531 		netif_wake_queue(dev);
532 	}
533 
534 	if (wc->status != IB_WC_SUCCESS &&
535 	    wc->status != IB_WC_WR_FLUSH_ERR) {
536 		struct ipoib_neigh *neigh;
537 
538 		ipoib_dbg(priv, "failed cm send event "
539 			   "(status=%d, wrid=%d vend_err %x)\n",
540 			   wc->status, wr_id, wc->vendor_err);
541 
542 		spin_lock(&priv->lock);
543 		neigh = tx->neigh;
544 
545 		if (neigh) {
546 			neigh->cm = NULL;
547 			list_del(&neigh->list);
548 			if (neigh->ah)
549 				ipoib_put_ah(neigh->ah);
550 			ipoib_neigh_free(dev, neigh);
551 
552 			tx->neigh = NULL;
553 		}
554 
555 		/* queue would be re-started anyway when TX is destroyed,
556 		 * but it makes sense to do it ASAP here. */
557 		if (test_and_clear_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags))
558 			netif_wake_queue(dev);
559 
560 		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
561 			list_move(&tx->list, &priv->cm.reap_list);
562 			queue_work(ipoib_workqueue, &priv->cm.reap_task);
563 		}
564 
565 		clear_bit(IPOIB_FLAG_OPER_UP, &tx->flags);
566 
567 		spin_unlock(&priv->lock);
568 	}
569 
570 	spin_unlock_irqrestore(&priv->tx_lock, flags);
571 }
572 
573 static void ipoib_cm_tx_completion(struct ib_cq *cq, void *tx_ptr)
574 {
575 	struct ipoib_cm_tx *tx = tx_ptr;
576 	int n, i;
577 
578 	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
579 	do {
580 		n = ib_poll_cq(cq, IPOIB_NUM_WC, tx->ibwc);
581 		for (i = 0; i < n; ++i)
582 			ipoib_cm_handle_tx_wc(tx->dev, tx, tx->ibwc + i);
583 	} while (n == IPOIB_NUM_WC);
584 }
585 
586 int ipoib_cm_dev_open(struct net_device *dev)
587 {
588 	struct ipoib_dev_priv *priv = netdev_priv(dev);
589 	int ret;
590 
591 	if (!IPOIB_CM_SUPPORTED(dev->dev_addr))
592 		return 0;
593 
594 	priv->cm.id = ib_create_cm_id(priv->ca, ipoib_cm_rx_handler, dev);
595 	if (IS_ERR(priv->cm.id)) {
596 		printk(KERN_WARNING "%s: failed to create CM ID\n", priv->ca->name);
597 		return IS_ERR(priv->cm.id);
598 	}
599 
600 	ret = ib_cm_listen(priv->cm.id, cpu_to_be64(IPOIB_CM_IETF_ID | priv->qp->qp_num),
601 			   0, NULL);
602 	if (ret) {
603 		printk(KERN_WARNING "%s: failed to listen on ID 0x%llx\n", priv->ca->name,
604 		       IPOIB_CM_IETF_ID | priv->qp->qp_num);
605 		ib_destroy_cm_id(priv->cm.id);
606 		return ret;
607 	}
608 	return 0;
609 }
610 
611 void ipoib_cm_dev_stop(struct net_device *dev)
612 {
613 	struct ipoib_dev_priv *priv = netdev_priv(dev);
614 	struct ipoib_cm_rx *p;
615 	unsigned long flags;
616 
617 	if (!IPOIB_CM_SUPPORTED(dev->dev_addr))
618 		return;
619 
620 	ib_destroy_cm_id(priv->cm.id);
621 	spin_lock_irqsave(&priv->lock, flags);
622 	while (!list_empty(&priv->cm.passive_ids)) {
623 		p = list_entry(priv->cm.passive_ids.next, typeof(*p), list);
624 		list_del_init(&p->list);
625 		spin_unlock_irqrestore(&priv->lock, flags);
626 		ib_destroy_cm_id(p->id);
627 		ib_destroy_qp(p->qp);
628 		kfree(p);
629 		spin_lock_irqsave(&priv->lock, flags);
630 	}
631 	spin_unlock_irqrestore(&priv->lock, flags);
632 
633 	cancel_delayed_work(&priv->cm.stale_task);
634 }
635 
636 static int ipoib_cm_rep_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
637 {
638 	struct ipoib_cm_tx *p = cm_id->context;
639 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
640 	struct ipoib_cm_data *data = event->private_data;
641 	struct sk_buff_head skqueue;
642 	struct ib_qp_attr qp_attr;
643 	int qp_attr_mask, ret;
644 	struct sk_buff *skb;
645 	unsigned long flags;
646 
647 	p->mtu = be32_to_cpu(data->mtu);
648 
649 	if (p->mtu < priv->dev->mtu + IPOIB_ENCAP_LEN) {
650 		ipoib_warn(priv, "Rejecting connection: mtu %d < device mtu %d + 4\n",
651 			   p->mtu, priv->dev->mtu);
652 		return -EINVAL;
653 	}
654 
655 	qp_attr.qp_state = IB_QPS_RTR;
656 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
657 	if (ret) {
658 		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
659 		return ret;
660 	}
661 
662 	qp_attr.rq_psn = 0 /* FIXME */;
663 	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
664 	if (ret) {
665 		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
666 		return ret;
667 	}
668 
669 	qp_attr.qp_state = IB_QPS_RTS;
670 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
671 	if (ret) {
672 		ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret);
673 		return ret;
674 	}
675 	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
676 	if (ret) {
677 		ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret);
678 		return ret;
679 	}
680 
681 	skb_queue_head_init(&skqueue);
682 
683 	spin_lock_irqsave(&priv->lock, flags);
684 	set_bit(IPOIB_FLAG_OPER_UP, &p->flags);
685 	if (p->neigh)
686 		while ((skb = __skb_dequeue(&p->neigh->queue)))
687 			__skb_queue_tail(&skqueue, skb);
688 	spin_unlock_irqrestore(&priv->lock, flags);
689 
690 	while ((skb = __skb_dequeue(&skqueue))) {
691 		skb->dev = p->dev;
692 		if (dev_queue_xmit(skb))
693 			ipoib_warn(priv, "dev_queue_xmit failed "
694 				   "to requeue packet\n");
695 	}
696 
697 	ret = ib_send_cm_rtu(cm_id, NULL, 0);
698 	if (ret) {
699 		ipoib_warn(priv, "failed to send RTU: %d\n", ret);
700 		return ret;
701 	}
702 	return 0;
703 }
704 
705 static struct ib_qp *ipoib_cm_create_tx_qp(struct net_device *dev, struct ib_cq *cq)
706 {
707 	struct ipoib_dev_priv *priv = netdev_priv(dev);
708 	struct ib_qp_init_attr attr = {};
709 	attr.recv_cq = priv->cq;
710 	attr.srq = priv->cm.srq;
711 	attr.cap.max_send_wr = ipoib_sendq_size;
712 	attr.cap.max_send_sge = 1;
713 	attr.sq_sig_type = IB_SIGNAL_ALL_WR;
714 	attr.qp_type = IB_QPT_RC;
715 	attr.send_cq = cq;
716 	return ib_create_qp(priv->pd, &attr);
717 }
718 
719 static int ipoib_cm_send_req(struct net_device *dev,
720 			     struct ib_cm_id *id, struct ib_qp *qp,
721 			     u32 qpn,
722 			     struct ib_sa_path_rec *pathrec)
723 {
724 	struct ipoib_dev_priv *priv = netdev_priv(dev);
725 	struct ipoib_cm_data data = {};
726 	struct ib_cm_req_param req = {};
727 
728 	data.qpn = cpu_to_be32(priv->qp->qp_num);
729 	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
730 
731 	req.primary_path 	      = pathrec;
732 	req.alternate_path 	      = NULL;
733 	req.service_id                = cpu_to_be64(IPOIB_CM_IETF_ID | qpn);
734 	req.qp_num 		      = qp->qp_num;
735 	req.qp_type 		      = qp->qp_type;
736 	req.private_data 	      = &data;
737 	req.private_data_len 	      = sizeof data;
738 	req.flow_control 	      = 0;
739 
740 	req.starting_psn              = 0; /* FIXME */
741 
742 	/*
743 	 * Pick some arbitrary defaults here; we could make these
744 	 * module parameters if anyone cared about setting them.
745 	 */
746 	req.responder_resources	      = 4;
747 	req.remote_cm_response_timeout = 20;
748 	req.local_cm_response_timeout  = 20;
749 	req.retry_count 	      = 0; /* RFC draft warns against retries */
750 	req.rnr_retry_count 	      = 0; /* RFC draft warns against retries */
751 	req.max_cm_retries 	      = 15;
752 	req.srq 	              = 1;
753 	return ib_send_cm_req(id, &req);
754 }
755 
756 static int ipoib_cm_modify_tx_init(struct net_device *dev,
757 				  struct ib_cm_id *cm_id, struct ib_qp *qp)
758 {
759 	struct ipoib_dev_priv *priv = netdev_priv(dev);
760 	struct ib_qp_attr qp_attr;
761 	int qp_attr_mask, ret;
762 	ret = ib_find_cached_pkey(priv->ca, priv->port, priv->pkey, &qp_attr.pkey_index);
763 	if (ret) {
764 		ipoib_warn(priv, "pkey 0x%x not in cache: %d\n", priv->pkey, ret);
765 		return ret;
766 	}
767 
768 	qp_attr.qp_state = IB_QPS_INIT;
769 	qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE;
770 	qp_attr.port_num = priv->port;
771 	qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PKEY_INDEX | IB_QP_PORT;
772 
773 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
774 	if (ret) {
775 		ipoib_warn(priv, "failed to modify tx QP to INIT: %d\n", ret);
776 		return ret;
777 	}
778 	return 0;
779 }
780 
781 static int ipoib_cm_tx_init(struct ipoib_cm_tx *p, u32 qpn,
782 			    struct ib_sa_path_rec *pathrec)
783 {
784 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
785 	int ret;
786 
787 	p->tx_ring = kzalloc(ipoib_sendq_size * sizeof *p->tx_ring,
788 				GFP_KERNEL);
789 	if (!p->tx_ring) {
790 		ipoib_warn(priv, "failed to allocate tx ring\n");
791 		ret = -ENOMEM;
792 		goto err_tx;
793 	}
794 
795 	p->cq = ib_create_cq(priv->ca, ipoib_cm_tx_completion, NULL, p,
796 			     ipoib_sendq_size + 1);
797 	if (IS_ERR(p->cq)) {
798 		ret = PTR_ERR(p->cq);
799 		ipoib_warn(priv, "failed to allocate tx cq: %d\n", ret);
800 		goto err_cq;
801 	}
802 
803 	ret = ib_req_notify_cq(p->cq, IB_CQ_NEXT_COMP);
804 	if (ret) {
805 		ipoib_warn(priv, "failed to request completion notification: %d\n", ret);
806 		goto err_req_notify;
807 	}
808 
809 	p->qp = ipoib_cm_create_tx_qp(p->dev, p->cq);
810 	if (IS_ERR(p->qp)) {
811 		ret = PTR_ERR(p->qp);
812 		ipoib_warn(priv, "failed to allocate tx qp: %d\n", ret);
813 		goto err_qp;
814 	}
815 
816 	p->id = ib_create_cm_id(priv->ca, ipoib_cm_tx_handler, p);
817 	if (IS_ERR(p->id)) {
818 		ret = PTR_ERR(p->id);
819 		ipoib_warn(priv, "failed to create tx cm id: %d\n", ret);
820 		goto err_id;
821 	}
822 
823 	ret = ipoib_cm_modify_tx_init(p->dev, p->id,  p->qp);
824 	if (ret) {
825 		ipoib_warn(priv, "failed to modify tx qp to rtr: %d\n", ret);
826 		goto err_modify;
827 	}
828 
829 	ret = ipoib_cm_send_req(p->dev, p->id, p->qp, qpn, pathrec);
830 	if (ret) {
831 		ipoib_warn(priv, "failed to send cm req: %d\n", ret);
832 		goto err_send_cm;
833 	}
834 
835 	ipoib_dbg(priv, "Request connection 0x%x for gid " IPOIB_GID_FMT " qpn 0x%x\n",
836 		  p->qp->qp_num, IPOIB_GID_ARG(pathrec->dgid), qpn);
837 
838 	return 0;
839 
840 err_send_cm:
841 err_modify:
842 	ib_destroy_cm_id(p->id);
843 err_id:
844 	p->id = NULL;
845 	ib_destroy_qp(p->qp);
846 err_req_notify:
847 err_qp:
848 	p->qp = NULL;
849 	ib_destroy_cq(p->cq);
850 err_cq:
851 	p->cq = NULL;
852 err_tx:
853 	return ret;
854 }
855 
856 static void ipoib_cm_tx_destroy(struct ipoib_cm_tx *p)
857 {
858 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
859 	struct ipoib_tx_buf *tx_req;
860 
861 	ipoib_dbg(priv, "Destroy active connection 0x%x head 0x%x tail 0x%x\n",
862 		  p->qp ? p->qp->qp_num : 0, p->tx_head, p->tx_tail);
863 
864 	if (p->id)
865 		ib_destroy_cm_id(p->id);
866 
867 	if (p->qp)
868 		ib_destroy_qp(p->qp);
869 
870 	if (p->cq)
871 		ib_destroy_cq(p->cq);
872 
873 	if (test_bit(IPOIB_FLAG_NETIF_STOPPED, &p->flags))
874 		netif_wake_queue(p->dev);
875 
876 	if (p->tx_ring) {
877 		while ((int) p->tx_tail - (int) p->tx_head < 0) {
878 			tx_req = &p->tx_ring[p->tx_tail & (ipoib_sendq_size - 1)];
879 			ib_dma_unmap_single(priv->ca, tx_req->mapping, tx_req->skb->len,
880 					 DMA_TO_DEVICE);
881 			dev_kfree_skb_any(tx_req->skb);
882 			++p->tx_tail;
883 		}
884 
885 		kfree(p->tx_ring);
886 	}
887 
888 	kfree(p);
889 }
890 
891 static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
892 			       struct ib_cm_event *event)
893 {
894 	struct ipoib_cm_tx *tx = cm_id->context;
895 	struct ipoib_dev_priv *priv = netdev_priv(tx->dev);
896 	struct net_device *dev = priv->dev;
897 	struct ipoib_neigh *neigh;
898 	unsigned long flags;
899 	int ret;
900 
901 	switch (event->event) {
902 	case IB_CM_DREQ_RECEIVED:
903 		ipoib_dbg(priv, "DREQ received.\n");
904 		ib_send_cm_drep(cm_id, NULL, 0);
905 		break;
906 	case IB_CM_REP_RECEIVED:
907 		ipoib_dbg(priv, "REP received.\n");
908 		ret = ipoib_cm_rep_handler(cm_id, event);
909 		if (ret)
910 			ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,
911 				       NULL, 0, NULL, 0);
912 		break;
913 	case IB_CM_REQ_ERROR:
914 	case IB_CM_REJ_RECEIVED:
915 	case IB_CM_TIMEWAIT_EXIT:
916 		ipoib_dbg(priv, "CM error %d.\n", event->event);
917 		spin_lock_irqsave(&priv->tx_lock, flags);
918 		spin_lock(&priv->lock);
919 		neigh = tx->neigh;
920 
921 		if (neigh) {
922 			neigh->cm = NULL;
923 			list_del(&neigh->list);
924 			if (neigh->ah)
925 				ipoib_put_ah(neigh->ah);
926 			ipoib_neigh_free(dev, neigh);
927 
928 			tx->neigh = NULL;
929 		}
930 
931 		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
932 			list_move(&tx->list, &priv->cm.reap_list);
933 			queue_work(ipoib_workqueue, &priv->cm.reap_task);
934 		}
935 
936 		spin_unlock(&priv->lock);
937 		spin_unlock_irqrestore(&priv->tx_lock, flags);
938 		break;
939 	default:
940 		break;
941 	}
942 
943 	return 0;
944 }
945 
946 struct ipoib_cm_tx *ipoib_cm_create_tx(struct net_device *dev, struct ipoib_path *path,
947 				       struct ipoib_neigh *neigh)
948 {
949 	struct ipoib_dev_priv *priv = netdev_priv(dev);
950 	struct ipoib_cm_tx *tx;
951 
952 	tx = kzalloc(sizeof *tx, GFP_ATOMIC);
953 	if (!tx)
954 		return NULL;
955 
956 	neigh->cm = tx;
957 	tx->neigh = neigh;
958 	tx->path = path;
959 	tx->dev = dev;
960 	list_add(&tx->list, &priv->cm.start_list);
961 	set_bit(IPOIB_FLAG_INITIALIZED, &tx->flags);
962 	queue_work(ipoib_workqueue, &priv->cm.start_task);
963 	return tx;
964 }
965 
966 void ipoib_cm_destroy_tx(struct ipoib_cm_tx *tx)
967 {
968 	struct ipoib_dev_priv *priv = netdev_priv(tx->dev);
969 	if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
970 		list_move(&tx->list, &priv->cm.reap_list);
971 		queue_work(ipoib_workqueue, &priv->cm.reap_task);
972 		ipoib_dbg(priv, "Reap connection for gid " IPOIB_GID_FMT "\n",
973 			  IPOIB_GID_ARG(tx->neigh->dgid));
974 		tx->neigh = NULL;
975 	}
976 }
977 
978 static void ipoib_cm_tx_start(struct work_struct *work)
979 {
980 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
981 						   cm.start_task);
982 	struct net_device *dev = priv->dev;
983 	struct ipoib_neigh *neigh;
984 	struct ipoib_cm_tx *p;
985 	unsigned long flags;
986 	int ret;
987 
988 	struct ib_sa_path_rec pathrec;
989 	u32 qpn;
990 
991 	spin_lock_irqsave(&priv->tx_lock, flags);
992 	spin_lock(&priv->lock);
993 	while (!list_empty(&priv->cm.start_list)) {
994 		p = list_entry(priv->cm.start_list.next, typeof(*p), list);
995 		list_del_init(&p->list);
996 		neigh = p->neigh;
997 		qpn = IPOIB_QPN(neigh->neighbour->ha);
998 		memcpy(&pathrec, &p->path->pathrec, sizeof pathrec);
999 		spin_unlock(&priv->lock);
1000 		spin_unlock_irqrestore(&priv->tx_lock, flags);
1001 		ret = ipoib_cm_tx_init(p, qpn, &pathrec);
1002 		spin_lock_irqsave(&priv->tx_lock, flags);
1003 		spin_lock(&priv->lock);
1004 		if (ret) {
1005 			neigh = p->neigh;
1006 			if (neigh) {
1007 				neigh->cm = NULL;
1008 				list_del(&neigh->list);
1009 				if (neigh->ah)
1010 					ipoib_put_ah(neigh->ah);
1011 				ipoib_neigh_free(dev, neigh);
1012 			}
1013 			list_del(&p->list);
1014 			kfree(p);
1015 		}
1016 	}
1017 	spin_unlock(&priv->lock);
1018 	spin_unlock_irqrestore(&priv->tx_lock, flags);
1019 }
1020 
1021 static void ipoib_cm_tx_reap(struct work_struct *work)
1022 {
1023 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1024 						   cm.reap_task);
1025 	struct ipoib_cm_tx *p;
1026 	unsigned long flags;
1027 
1028 	spin_lock_irqsave(&priv->tx_lock, flags);
1029 	spin_lock(&priv->lock);
1030 	while (!list_empty(&priv->cm.reap_list)) {
1031 		p = list_entry(priv->cm.reap_list.next, typeof(*p), list);
1032 		list_del(&p->list);
1033 		spin_unlock(&priv->lock);
1034 		spin_unlock_irqrestore(&priv->tx_lock, flags);
1035 		ipoib_cm_tx_destroy(p);
1036 		spin_lock_irqsave(&priv->tx_lock, flags);
1037 		spin_lock(&priv->lock);
1038 	}
1039 	spin_unlock(&priv->lock);
1040 	spin_unlock_irqrestore(&priv->tx_lock, flags);
1041 }
1042 
1043 static void ipoib_cm_skb_reap(struct work_struct *work)
1044 {
1045 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1046 						   cm.skb_task);
1047 	struct net_device *dev = priv->dev;
1048 	struct sk_buff *skb;
1049 	unsigned long flags;
1050 
1051 	unsigned mtu = priv->mcast_mtu;
1052 
1053 	spin_lock_irqsave(&priv->tx_lock, flags);
1054 	spin_lock(&priv->lock);
1055 	while ((skb = skb_dequeue(&priv->cm.skb_queue))) {
1056 		spin_unlock(&priv->lock);
1057 		spin_unlock_irqrestore(&priv->tx_lock, flags);
1058 		if (skb->protocol == htons(ETH_P_IP))
1059 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
1060 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1061 		else if (skb->protocol == htons(ETH_P_IPV6))
1062 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
1063 #endif
1064 		dev_kfree_skb_any(skb);
1065 		spin_lock_irqsave(&priv->tx_lock, flags);
1066 		spin_lock(&priv->lock);
1067 	}
1068 	spin_unlock(&priv->lock);
1069 	spin_unlock_irqrestore(&priv->tx_lock, flags);
1070 }
1071 
1072 void ipoib_cm_skb_too_long(struct net_device* dev, struct sk_buff *skb,
1073 			   unsigned int mtu)
1074 {
1075 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1076 	int e = skb_queue_empty(&priv->cm.skb_queue);
1077 
1078 	if (skb->dst)
1079 		skb->dst->ops->update_pmtu(skb->dst, mtu);
1080 
1081 	skb_queue_tail(&priv->cm.skb_queue, skb);
1082 	if (e)
1083 		queue_work(ipoib_workqueue, &priv->cm.skb_task);
1084 }
1085 
1086 static void ipoib_cm_stale_task(struct work_struct *work)
1087 {
1088 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1089 						   cm.stale_task.work);
1090 	struct ipoib_cm_rx *p;
1091 	unsigned long flags;
1092 
1093 	spin_lock_irqsave(&priv->lock, flags);
1094 	while (!list_empty(&priv->cm.passive_ids)) {
1095 		/* List if sorted by LRU, start from tail,
1096 		 * stop when we see a recently used entry */
1097 		p = list_entry(priv->cm.passive_ids.prev, typeof(*p), list);
1098 		if (time_after_eq(jiffies, p->jiffies + IPOIB_CM_RX_TIMEOUT))
1099 			break;
1100 		list_del_init(&p->list);
1101 		spin_unlock_irqrestore(&priv->lock, flags);
1102 		ib_destroy_cm_id(p->id);
1103 		ib_destroy_qp(p->qp);
1104 		kfree(p);
1105 		spin_lock_irqsave(&priv->lock, flags);
1106 	}
1107 	spin_unlock_irqrestore(&priv->lock, flags);
1108 }
1109 
1110 
1111 static ssize_t show_mode(struct device *d, struct device_attribute *attr,
1112 			 char *buf)
1113 {
1114 	struct ipoib_dev_priv *priv = netdev_priv(to_net_dev(d));
1115 
1116 	if (test_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags))
1117 		return sprintf(buf, "connected\n");
1118 	else
1119 		return sprintf(buf, "datagram\n");
1120 }
1121 
1122 static ssize_t set_mode(struct device *d, struct device_attribute *attr,
1123 			const char *buf, size_t count)
1124 {
1125 	struct net_device *dev = to_net_dev(d);
1126 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1127 
1128 	/* flush paths if we switch modes so that connections are restarted */
1129 	if (IPOIB_CM_SUPPORTED(dev->dev_addr) && !strcmp(buf, "connected\n")) {
1130 		set_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags);
1131 		ipoib_warn(priv, "enabling connected mode "
1132 			   "will cause multicast packet drops\n");
1133 		ipoib_flush_paths(dev);
1134 		return count;
1135 	}
1136 
1137 	if (!strcmp(buf, "datagram\n")) {
1138 		clear_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags);
1139 		dev->mtu = min(priv->mcast_mtu, dev->mtu);
1140 		ipoib_flush_paths(dev);
1141 		return count;
1142 	}
1143 
1144 	return -EINVAL;
1145 }
1146 
1147 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, show_mode, set_mode);
1148 
1149 int ipoib_cm_add_mode_attr(struct net_device *dev)
1150 {
1151 	return device_create_file(&dev->dev, &dev_attr_mode);
1152 }
1153 
1154 int ipoib_cm_dev_init(struct net_device *dev)
1155 {
1156 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1157 	struct ib_srq_init_attr srq_init_attr = {
1158 		.attr = {
1159 			.max_wr  = ipoib_recvq_size,
1160 			.max_sge = IPOIB_CM_RX_SG
1161 		}
1162 	};
1163 	int ret, i;
1164 
1165 	INIT_LIST_HEAD(&priv->cm.passive_ids);
1166 	INIT_LIST_HEAD(&priv->cm.reap_list);
1167 	INIT_LIST_HEAD(&priv->cm.start_list);
1168 	INIT_WORK(&priv->cm.start_task, ipoib_cm_tx_start);
1169 	INIT_WORK(&priv->cm.reap_task, ipoib_cm_tx_reap);
1170 	INIT_WORK(&priv->cm.skb_task, ipoib_cm_skb_reap);
1171 	INIT_DELAYED_WORK(&priv->cm.stale_task, ipoib_cm_stale_task);
1172 
1173 	skb_queue_head_init(&priv->cm.skb_queue);
1174 
1175 	priv->cm.srq = ib_create_srq(priv->pd, &srq_init_attr);
1176 	if (IS_ERR(priv->cm.srq)) {
1177 		ret = PTR_ERR(priv->cm.srq);
1178 		priv->cm.srq = NULL;
1179 		return ret;
1180 	}
1181 
1182 	priv->cm.srq_ring = kzalloc(ipoib_recvq_size * sizeof *priv->cm.srq_ring,
1183 				    GFP_KERNEL);
1184 	if (!priv->cm.srq_ring) {
1185 		printk(KERN_WARNING "%s: failed to allocate CM ring (%d entries)\n",
1186 		       priv->ca->name, ipoib_recvq_size);
1187 		ipoib_cm_dev_cleanup(dev);
1188 		return -ENOMEM;
1189 	}
1190 
1191 	for (i = 0; i < IPOIB_CM_RX_SG; ++i)
1192 		priv->cm.rx_sge[i].lkey	= priv->mr->lkey;
1193 
1194 	priv->cm.rx_sge[0].length = IPOIB_CM_HEAD_SIZE;
1195 	for (i = 1; i < IPOIB_CM_RX_SG; ++i)
1196 		priv->cm.rx_sge[i].length = PAGE_SIZE;
1197 	priv->cm.rx_wr.next = NULL;
1198 	priv->cm.rx_wr.sg_list = priv->cm.rx_sge;
1199 	priv->cm.rx_wr.num_sge = IPOIB_CM_RX_SG;
1200 
1201 	for (i = 0; i < ipoib_recvq_size; ++i) {
1202 		if (!ipoib_cm_alloc_rx_skb(dev, i, IPOIB_CM_RX_SG - 1,
1203 					   priv->cm.srq_ring[i].mapping)) {
1204 			ipoib_warn(priv, "failed to allocate receive buffer %d\n", i);
1205 			ipoib_cm_dev_cleanup(dev);
1206 			return -ENOMEM;
1207 		}
1208 		if (ipoib_cm_post_receive(dev, i)) {
1209 			ipoib_warn(priv, "ipoib_ib_post_receive failed for buf %d\n", i);
1210 			ipoib_cm_dev_cleanup(dev);
1211 			return -EIO;
1212 		}
1213 	}
1214 
1215 	priv->dev->dev_addr[0] = IPOIB_FLAGS_RC;
1216 	return 0;
1217 }
1218 
1219 void ipoib_cm_dev_cleanup(struct net_device *dev)
1220 {
1221 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1222 	int i, ret;
1223 
1224 	if (!priv->cm.srq)
1225 		return;
1226 
1227 	ipoib_dbg(priv, "Cleanup ipoib connected mode.\n");
1228 
1229 	ret = ib_destroy_srq(priv->cm.srq);
1230 	if (ret)
1231 		ipoib_warn(priv, "ib_destroy_srq failed: %d\n", ret);
1232 
1233 	priv->cm.srq = NULL;
1234 	if (!priv->cm.srq_ring)
1235 		return;
1236 	for (i = 0; i < ipoib_recvq_size; ++i)
1237 		if (priv->cm.srq_ring[i].skb) {
1238 			ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
1239 					      priv->cm.srq_ring[i].mapping);
1240 			dev_kfree_skb_any(priv->cm.srq_ring[i].skb);
1241 			priv->cm.srq_ring[i].skb = NULL;
1242 		}
1243 	kfree(priv->cm.srq_ring);
1244 	priv->cm.srq_ring = NULL;
1245 }
1246