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 #include <linux/delay.h>
41 
42 #ifdef CONFIG_INFINIBAND_IPOIB_DEBUG_DATA
43 static int data_debug_level;
44 
45 module_param_named(cm_data_debug_level, data_debug_level, int, 0644);
46 MODULE_PARM_DESC(cm_data_debug_level,
47 		 "Enable data path debug tracing for connected mode if > 0");
48 #endif
49 
50 #include "ipoib.h"
51 
52 #define IPOIB_CM_IETF_ID 0x1000000000000000ULL
53 
54 #define IPOIB_CM_RX_UPDATE_TIME (256 * HZ)
55 #define IPOIB_CM_RX_TIMEOUT     (2 * 256 * HZ)
56 #define IPOIB_CM_RX_DELAY       (3 * 256 * HZ)
57 #define IPOIB_CM_RX_UPDATE_MASK (0x3)
58 
59 static struct ib_qp_attr ipoib_cm_err_attr = {
60 	.qp_state = IB_QPS_ERR
61 };
62 
63 #define IPOIB_CM_RX_DRAIN_WRID 0x7fffffff
64 
65 static struct ib_send_wr ipoib_cm_rx_drain_wr = {
66 	.wr_id = IPOIB_CM_RX_DRAIN_WRID,
67 	.opcode = IB_WR_SEND,
68 };
69 
70 static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
71 			       struct ib_cm_event *event);
72 
73 static void ipoib_cm_dma_unmap_rx(struct ipoib_dev_priv *priv, int frags,
74 				  u64 mapping[IPOIB_CM_RX_SG])
75 {
76 	int i;
77 
78 	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
79 
80 	for (i = 0; i < frags; ++i)
81 		ib_dma_unmap_single(priv->ca, mapping[i + 1], PAGE_SIZE, DMA_FROM_DEVICE);
82 }
83 
84 static int ipoib_cm_post_receive(struct net_device *dev, int id)
85 {
86 	struct ipoib_dev_priv *priv = netdev_priv(dev);
87 	struct ib_recv_wr *bad_wr;
88 	int i, ret;
89 
90 	priv->cm.rx_wr.wr_id = id | IPOIB_CM_OP_SRQ;
91 
92 	for (i = 0; i < IPOIB_CM_RX_SG; ++i)
93 		priv->cm.rx_sge[i].addr = priv->cm.srq_ring[id].mapping[i];
94 
95 	ret = ib_post_srq_recv(priv->cm.srq, &priv->cm.rx_wr, &bad_wr);
96 	if (unlikely(ret)) {
97 		ipoib_warn(priv, "post srq failed for buf %d (%d)\n", id, ret);
98 		ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
99 				      priv->cm.srq_ring[id].mapping);
100 		dev_kfree_skb_any(priv->cm.srq_ring[id].skb);
101 		priv->cm.srq_ring[id].skb = NULL;
102 	}
103 
104 	return ret;
105 }
106 
107 static struct sk_buff *ipoib_cm_alloc_rx_skb(struct net_device *dev, int id, int frags,
108 					     u64 mapping[IPOIB_CM_RX_SG])
109 {
110 	struct ipoib_dev_priv *priv = netdev_priv(dev);
111 	struct sk_buff *skb;
112 	int i;
113 
114 	skb = dev_alloc_skb(IPOIB_CM_HEAD_SIZE + 12);
115 	if (unlikely(!skb))
116 		return NULL;
117 
118 	/*
119 	 * IPoIB adds a 4 byte header. So we need 12 more bytes to align the
120 	 * IP header to a multiple of 16.
121 	 */
122 	skb_reserve(skb, 12);
123 
124 	mapping[0] = ib_dma_map_single(priv->ca, skb->data, IPOIB_CM_HEAD_SIZE,
125 				       DMA_FROM_DEVICE);
126 	if (unlikely(ib_dma_mapping_error(priv->ca, mapping[0]))) {
127 		dev_kfree_skb_any(skb);
128 		return NULL;
129 	}
130 
131 	for (i = 0; i < frags; i++) {
132 		struct page *page = alloc_page(GFP_ATOMIC);
133 
134 		if (!page)
135 			goto partial_error;
136 		skb_fill_page_desc(skb, i, page, 0, PAGE_SIZE);
137 
138 		mapping[i + 1] = ib_dma_map_page(priv->ca, skb_shinfo(skb)->frags[i].page,
139 						 0, PAGE_SIZE, DMA_FROM_DEVICE);
140 		if (unlikely(ib_dma_mapping_error(priv->ca, mapping[i + 1])))
141 			goto partial_error;
142 	}
143 
144 	priv->cm.srq_ring[id].skb = skb;
145 	return skb;
146 
147 partial_error:
148 
149 	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
150 
151 	for (; i > 0; --i)
152 		ib_dma_unmap_single(priv->ca, mapping[i], PAGE_SIZE, DMA_FROM_DEVICE);
153 
154 	dev_kfree_skb_any(skb);
155 	return NULL;
156 }
157 
158 static void ipoib_cm_start_rx_drain(struct ipoib_dev_priv* priv)
159 {
160 	struct ib_send_wr *bad_wr;
161 	struct ipoib_cm_rx *p;
162 
163 	/* We only reserved 1 extra slot in CQ for drain WRs, so
164 	 * make sure we have at most 1 outstanding WR. */
165 	if (list_empty(&priv->cm.rx_flush_list) ||
166 	    !list_empty(&priv->cm.rx_drain_list))
167 		return;
168 
169 	/*
170 	 * QPs on flush list are error state.  This way, a "flush
171 	 * error" WC will be immediately generated for each WR we post.
172 	 */
173 	p = list_entry(priv->cm.rx_flush_list.next, typeof(*p), list);
174 	if (ib_post_send(p->qp, &ipoib_cm_rx_drain_wr, &bad_wr))
175 		ipoib_warn(priv, "failed to post drain wr\n");
176 
177 	list_splice_init(&priv->cm.rx_flush_list, &priv->cm.rx_drain_list);
178 }
179 
180 static void ipoib_cm_rx_event_handler(struct ib_event *event, void *ctx)
181 {
182 	struct ipoib_cm_rx *p = ctx;
183 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
184 	unsigned long flags;
185 
186 	if (event->event != IB_EVENT_QP_LAST_WQE_REACHED)
187 		return;
188 
189 	spin_lock_irqsave(&priv->lock, flags);
190 	list_move(&p->list, &priv->cm.rx_flush_list);
191 	p->state = IPOIB_CM_RX_FLUSH;
192 	ipoib_cm_start_rx_drain(priv);
193 	spin_unlock_irqrestore(&priv->lock, flags);
194 }
195 
196 static struct ib_qp *ipoib_cm_create_rx_qp(struct net_device *dev,
197 					   struct ipoib_cm_rx *p)
198 {
199 	struct ipoib_dev_priv *priv = netdev_priv(dev);
200 	struct ib_qp_init_attr attr = {
201 		.event_handler = ipoib_cm_rx_event_handler,
202 		.send_cq = priv->cq, /* For drain WR */
203 		.recv_cq = priv->cq,
204 		.srq = priv->cm.srq,
205 		.cap.max_send_wr = 1, /* For drain WR */
206 		.cap.max_send_sge = 1, /* FIXME: 0 Seems not to work */
207 		.sq_sig_type = IB_SIGNAL_ALL_WR,
208 		.qp_type = IB_QPT_RC,
209 		.qp_context = p,
210 	};
211 	return ib_create_qp(priv->pd, &attr);
212 }
213 
214 static int ipoib_cm_modify_rx_qp(struct net_device *dev,
215 				  struct ib_cm_id *cm_id, struct ib_qp *qp,
216 				  unsigned psn)
217 {
218 	struct ipoib_dev_priv *priv = netdev_priv(dev);
219 	struct ib_qp_attr qp_attr;
220 	int qp_attr_mask, ret;
221 
222 	qp_attr.qp_state = IB_QPS_INIT;
223 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
224 	if (ret) {
225 		ipoib_warn(priv, "failed to init QP attr for INIT: %d\n", ret);
226 		return ret;
227 	}
228 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
229 	if (ret) {
230 		ipoib_warn(priv, "failed to modify QP to INIT: %d\n", ret);
231 		return ret;
232 	}
233 	qp_attr.qp_state = IB_QPS_RTR;
234 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
235 	if (ret) {
236 		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
237 		return ret;
238 	}
239 	qp_attr.rq_psn = psn;
240 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
241 	if (ret) {
242 		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
243 		return ret;
244 	}
245 
246 	/*
247 	 * Current Mellanox HCA firmware won't generate completions
248 	 * with error for drain WRs unless the QP has been moved to
249 	 * RTS first. This work-around leaves a window where a QP has
250 	 * moved to error asynchronously, but this will eventually get
251 	 * fixed in firmware, so let's not error out if modify QP
252 	 * fails.
253 	 */
254 	qp_attr.qp_state = IB_QPS_RTS;
255 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
256 	if (ret) {
257 		ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret);
258 		return 0;
259 	}
260 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
261 	if (ret) {
262 		ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret);
263 		return 0;
264 	}
265 
266 	return 0;
267 }
268 
269 static int ipoib_cm_send_rep(struct net_device *dev, struct ib_cm_id *cm_id,
270 			     struct ib_qp *qp, struct ib_cm_req_event_param *req,
271 			     unsigned psn)
272 {
273 	struct ipoib_dev_priv *priv = netdev_priv(dev);
274 	struct ipoib_cm_data data = {};
275 	struct ib_cm_rep_param rep = {};
276 
277 	data.qpn = cpu_to_be32(priv->qp->qp_num);
278 	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
279 
280 	rep.private_data = &data;
281 	rep.private_data_len = sizeof data;
282 	rep.flow_control = 0;
283 	rep.rnr_retry_count = req->rnr_retry_count;
284 	rep.srq = 1;
285 	rep.qp_num = qp->qp_num;
286 	rep.starting_psn = psn;
287 	return ib_send_cm_rep(cm_id, &rep);
288 }
289 
290 static int ipoib_cm_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
291 {
292 	struct net_device *dev = cm_id->context;
293 	struct ipoib_dev_priv *priv = netdev_priv(dev);
294 	struct ipoib_cm_rx *p;
295 	unsigned psn;
296 	int ret;
297 
298 	ipoib_dbg(priv, "REQ arrived\n");
299 	p = kzalloc(sizeof *p, GFP_KERNEL);
300 	if (!p)
301 		return -ENOMEM;
302 	p->dev = dev;
303 	p->id = cm_id;
304 	cm_id->context = p;
305 	p->state = IPOIB_CM_RX_LIVE;
306 	p->jiffies = jiffies;
307 	INIT_LIST_HEAD(&p->list);
308 
309 	p->qp = ipoib_cm_create_rx_qp(dev, p);
310 	if (IS_ERR(p->qp)) {
311 		ret = PTR_ERR(p->qp);
312 		goto err_qp;
313 	}
314 
315 	psn = random32() & 0xffffff;
316 	ret = ipoib_cm_modify_rx_qp(dev, cm_id, p->qp, psn);
317 	if (ret)
318 		goto err_modify;
319 
320 	spin_lock_irq(&priv->lock);
321 	queue_delayed_work(ipoib_workqueue,
322 			   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
323 	/* Add this entry to passive ids list head, but do not re-add it
324 	 * if IB_EVENT_QP_LAST_WQE_REACHED has moved it to flush list. */
325 	p->jiffies = jiffies;
326 	if (p->state == IPOIB_CM_RX_LIVE)
327 		list_move(&p->list, &priv->cm.passive_ids);
328 	spin_unlock_irq(&priv->lock);
329 
330 	ret = ipoib_cm_send_rep(dev, cm_id, p->qp, &event->param.req_rcvd, psn);
331 	if (ret) {
332 		ipoib_warn(priv, "failed to send REP: %d\n", ret);
333 		if (ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE))
334 			ipoib_warn(priv, "unable to move qp to error state\n");
335 	}
336 	return 0;
337 
338 err_modify:
339 	ib_destroy_qp(p->qp);
340 err_qp:
341 	kfree(p);
342 	return ret;
343 }
344 
345 static int ipoib_cm_rx_handler(struct ib_cm_id *cm_id,
346 			       struct ib_cm_event *event)
347 {
348 	struct ipoib_cm_rx *p;
349 	struct ipoib_dev_priv *priv;
350 
351 	switch (event->event) {
352 	case IB_CM_REQ_RECEIVED:
353 		return ipoib_cm_req_handler(cm_id, event);
354 	case IB_CM_DREQ_RECEIVED:
355 		p = cm_id->context;
356 		ib_send_cm_drep(cm_id, NULL, 0);
357 		/* Fall through */
358 	case IB_CM_REJ_RECEIVED:
359 		p = cm_id->context;
360 		priv = netdev_priv(p->dev);
361 		if (ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE))
362 			ipoib_warn(priv, "unable to move qp to error state\n");
363 		/* Fall through */
364 	default:
365 		return 0;
366 	}
367 }
368 /* Adjust length of skb with fragments to match received data */
369 static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space,
370 			  unsigned int length, struct sk_buff *toskb)
371 {
372 	int i, num_frags;
373 	unsigned int size;
374 
375 	/* put header into skb */
376 	size = min(length, hdr_space);
377 	skb->tail += size;
378 	skb->len += size;
379 	length -= size;
380 
381 	num_frags = skb_shinfo(skb)->nr_frags;
382 	for (i = 0; i < num_frags; i++) {
383 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
384 
385 		if (length == 0) {
386 			/* don't need this page */
387 			skb_fill_page_desc(toskb, i, frag->page, 0, PAGE_SIZE);
388 			--skb_shinfo(skb)->nr_frags;
389 		} else {
390 			size = min(length, (unsigned) PAGE_SIZE);
391 
392 			frag->size = size;
393 			skb->data_len += size;
394 			skb->truesize += size;
395 			skb->len += size;
396 			length -= size;
397 		}
398 	}
399 }
400 
401 void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
402 {
403 	struct ipoib_dev_priv *priv = netdev_priv(dev);
404 	unsigned int wr_id = wc->wr_id & ~IPOIB_CM_OP_SRQ;
405 	struct sk_buff *skb, *newskb;
406 	struct ipoib_cm_rx *p;
407 	unsigned long flags;
408 	u64 mapping[IPOIB_CM_RX_SG];
409 	int frags;
410 
411 	ipoib_dbg_data(priv, "cm recv completion: id %d, status: %d\n",
412 		       wr_id, wc->status);
413 
414 	if (unlikely(wr_id >= ipoib_recvq_size)) {
415 		if (wr_id == (IPOIB_CM_RX_DRAIN_WRID & ~IPOIB_CM_OP_SRQ)) {
416 			spin_lock_irqsave(&priv->lock, flags);
417 			list_splice_init(&priv->cm.rx_drain_list, &priv->cm.rx_reap_list);
418 			ipoib_cm_start_rx_drain(priv);
419 			queue_work(ipoib_workqueue, &priv->cm.rx_reap_task);
420 			spin_unlock_irqrestore(&priv->lock, flags);
421 		} else
422 			ipoib_warn(priv, "cm recv completion event with wrid %d (> %d)\n",
423 				   wr_id, ipoib_recvq_size);
424 		return;
425 	}
426 
427 	skb  = priv->cm.srq_ring[wr_id].skb;
428 
429 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
430 		ipoib_dbg(priv, "cm recv error "
431 			   "(status=%d, wrid=%d vend_err %x)\n",
432 			   wc->status, wr_id, wc->vendor_err);
433 		++priv->stats.rx_dropped;
434 		goto repost;
435 	}
436 
437 	if (!likely(wr_id & IPOIB_CM_RX_UPDATE_MASK)) {
438 		p = wc->qp->qp_context;
439 		if (p && time_after_eq(jiffies, p->jiffies + IPOIB_CM_RX_UPDATE_TIME)) {
440 			spin_lock_irqsave(&priv->lock, flags);
441 			p->jiffies = jiffies;
442 			/* Move this entry to list head, but do not re-add it
443 			 * if it has been moved out of list. */
444 			if (p->state == IPOIB_CM_RX_LIVE)
445 				list_move(&p->list, &priv->cm.passive_ids);
446 			spin_unlock_irqrestore(&priv->lock, flags);
447 		}
448 	}
449 
450 	frags = PAGE_ALIGN(wc->byte_len - min(wc->byte_len,
451 					      (unsigned)IPOIB_CM_HEAD_SIZE)) / PAGE_SIZE;
452 
453 	newskb = ipoib_cm_alloc_rx_skb(dev, wr_id, frags, mapping);
454 	if (unlikely(!newskb)) {
455 		/*
456 		 * If we can't allocate a new RX buffer, dump
457 		 * this packet and reuse the old buffer.
458 		 */
459 		ipoib_dbg(priv, "failed to allocate receive buffer %d\n", wr_id);
460 		++priv->stats.rx_dropped;
461 		goto repost;
462 	}
463 
464 	ipoib_cm_dma_unmap_rx(priv, frags, priv->cm.srq_ring[wr_id].mapping);
465 	memcpy(priv->cm.srq_ring[wr_id].mapping, mapping, (frags + 1) * sizeof *mapping);
466 
467 	ipoib_dbg_data(priv, "received %d bytes, SLID 0x%04x\n",
468 		       wc->byte_len, wc->slid);
469 
470 	skb_put_frags(skb, IPOIB_CM_HEAD_SIZE, wc->byte_len, newskb);
471 
472 	skb->protocol = ((struct ipoib_header *) skb->data)->proto;
473 	skb_reset_mac_header(skb);
474 	skb_pull(skb, IPOIB_ENCAP_LEN);
475 
476 	dev->last_rx = jiffies;
477 	++priv->stats.rx_packets;
478 	priv->stats.rx_bytes += skb->len;
479 
480 	skb->dev = dev;
481 	/* XXX get correct PACKET_ type here */
482 	skb->pkt_type = PACKET_HOST;
483 	netif_receive_skb(skb);
484 
485 repost:
486 	if (unlikely(ipoib_cm_post_receive(dev, wr_id)))
487 		ipoib_warn(priv, "ipoib_cm_post_receive failed "
488 			   "for buf %d\n", wr_id);
489 }
490 
491 static inline int post_send(struct ipoib_dev_priv *priv,
492 			    struct ipoib_cm_tx *tx,
493 			    unsigned int wr_id,
494 			    u64 addr, int len)
495 {
496 	struct ib_send_wr *bad_wr;
497 
498 	priv->tx_sge.addr             = addr;
499 	priv->tx_sge.length           = len;
500 
501 	priv->tx_wr.wr_id 	      = wr_id;
502 
503 	return ib_post_send(tx->qp, &priv->tx_wr, &bad_wr);
504 }
505 
506 void ipoib_cm_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_cm_tx *tx)
507 {
508 	struct ipoib_dev_priv *priv = netdev_priv(dev);
509 	struct ipoib_tx_buf *tx_req;
510 	u64 addr;
511 
512 	if (unlikely(skb->len > tx->mtu)) {
513 		ipoib_warn(priv, "packet len %d (> %d) too long to send, dropping\n",
514 			   skb->len, tx->mtu);
515 		++priv->stats.tx_dropped;
516 		++priv->stats.tx_errors;
517 		ipoib_cm_skb_too_long(dev, skb, tx->mtu - IPOIB_ENCAP_LEN);
518 		return;
519 	}
520 
521 	ipoib_dbg_data(priv, "sending packet: head 0x%x length %d connection 0x%x\n",
522 		       tx->tx_head, skb->len, tx->qp->qp_num);
523 
524 	/*
525 	 * We put the skb into the tx_ring _before_ we call post_send()
526 	 * because it's entirely possible that the completion handler will
527 	 * run before we execute anything after the post_send().  That
528 	 * means we have to make sure everything is properly recorded and
529 	 * our state is consistent before we call post_send().
530 	 */
531 	tx_req = &tx->tx_ring[tx->tx_head & (ipoib_sendq_size - 1)];
532 	tx_req->skb = skb;
533 	addr = ib_dma_map_single(priv->ca, skb->data, skb->len, DMA_TO_DEVICE);
534 	if (unlikely(ib_dma_mapping_error(priv->ca, addr))) {
535 		++priv->stats.tx_errors;
536 		dev_kfree_skb_any(skb);
537 		return;
538 	}
539 
540 	tx_req->mapping = addr;
541 
542 	if (unlikely(post_send(priv, tx, tx->tx_head & (ipoib_sendq_size - 1),
543 			        addr, skb->len))) {
544 		ipoib_warn(priv, "post_send failed\n");
545 		++priv->stats.tx_errors;
546 		ib_dma_unmap_single(priv->ca, addr, skb->len, DMA_TO_DEVICE);
547 		dev_kfree_skb_any(skb);
548 	} else {
549 		dev->trans_start = jiffies;
550 		++tx->tx_head;
551 
552 		if (tx->tx_head - tx->tx_tail == ipoib_sendq_size) {
553 			ipoib_dbg(priv, "TX ring 0x%x full, stopping kernel net queue\n",
554 				  tx->qp->qp_num);
555 			netif_stop_queue(dev);
556 			set_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags);
557 		}
558 	}
559 }
560 
561 static void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ipoib_cm_tx *tx,
562 				  struct ib_wc *wc)
563 {
564 	struct ipoib_dev_priv *priv = netdev_priv(dev);
565 	unsigned int wr_id = wc->wr_id;
566 	struct ipoib_tx_buf *tx_req;
567 	unsigned long flags;
568 
569 	ipoib_dbg_data(priv, "cm send completion: id %d, status: %d\n",
570 		       wr_id, wc->status);
571 
572 	if (unlikely(wr_id >= ipoib_sendq_size)) {
573 		ipoib_warn(priv, "cm send completion event with wrid %d (> %d)\n",
574 			   wr_id, ipoib_sendq_size);
575 		return;
576 	}
577 
578 	tx_req = &tx->tx_ring[wr_id];
579 
580 	ib_dma_unmap_single(priv->ca, tx_req->mapping, tx_req->skb->len, DMA_TO_DEVICE);
581 
582 	/* FIXME: is this right? Shouldn't we only increment on success? */
583 	++priv->stats.tx_packets;
584 	priv->stats.tx_bytes += tx_req->skb->len;
585 
586 	dev_kfree_skb_any(tx_req->skb);
587 
588 	spin_lock_irqsave(&priv->tx_lock, flags);
589 	++tx->tx_tail;
590 	if (unlikely(test_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags)) &&
591 	    tx->tx_head - tx->tx_tail <= ipoib_sendq_size >> 1) {
592 		clear_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags);
593 		netif_wake_queue(dev);
594 	}
595 
596 	if (wc->status != IB_WC_SUCCESS &&
597 	    wc->status != IB_WC_WR_FLUSH_ERR) {
598 		struct ipoib_neigh *neigh;
599 
600 		ipoib_dbg(priv, "failed cm send event "
601 			   "(status=%d, wrid=%d vend_err %x)\n",
602 			   wc->status, wr_id, wc->vendor_err);
603 
604 		spin_lock(&priv->lock);
605 		neigh = tx->neigh;
606 
607 		if (neigh) {
608 			neigh->cm = NULL;
609 			list_del(&neigh->list);
610 			if (neigh->ah)
611 				ipoib_put_ah(neigh->ah);
612 			ipoib_neigh_free(dev, neigh);
613 
614 			tx->neigh = NULL;
615 		}
616 
617 		/* queue would be re-started anyway when TX is destroyed,
618 		 * but it makes sense to do it ASAP here. */
619 		if (test_and_clear_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags))
620 			netif_wake_queue(dev);
621 
622 		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
623 			list_move(&tx->list, &priv->cm.reap_list);
624 			queue_work(ipoib_workqueue, &priv->cm.reap_task);
625 		}
626 
627 		clear_bit(IPOIB_FLAG_OPER_UP, &tx->flags);
628 
629 		spin_unlock(&priv->lock);
630 	}
631 
632 	spin_unlock_irqrestore(&priv->tx_lock, flags);
633 }
634 
635 static void ipoib_cm_tx_completion(struct ib_cq *cq, void *tx_ptr)
636 {
637 	struct ipoib_cm_tx *tx = tx_ptr;
638 	int n, i;
639 
640 	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
641 	do {
642 		n = ib_poll_cq(cq, IPOIB_NUM_WC, tx->ibwc);
643 		for (i = 0; i < n; ++i)
644 			ipoib_cm_handle_tx_wc(tx->dev, tx, tx->ibwc + i);
645 	} while (n == IPOIB_NUM_WC);
646 }
647 
648 int ipoib_cm_dev_open(struct net_device *dev)
649 {
650 	struct ipoib_dev_priv *priv = netdev_priv(dev);
651 	int ret;
652 
653 	if (!IPOIB_CM_SUPPORTED(dev->dev_addr))
654 		return 0;
655 
656 	priv->cm.id = ib_create_cm_id(priv->ca, ipoib_cm_rx_handler, dev);
657 	if (IS_ERR(priv->cm.id)) {
658 		printk(KERN_WARNING "%s: failed to create CM ID\n", priv->ca->name);
659 		ret = PTR_ERR(priv->cm.id);
660 		goto err_cm;
661 	}
662 
663 	ret = ib_cm_listen(priv->cm.id, cpu_to_be64(IPOIB_CM_IETF_ID | priv->qp->qp_num),
664 			   0, NULL);
665 	if (ret) {
666 		printk(KERN_WARNING "%s: failed to listen on ID 0x%llx\n", priv->ca->name,
667 		       IPOIB_CM_IETF_ID | priv->qp->qp_num);
668 		goto err_listen;
669 	}
670 
671 	return 0;
672 
673 err_listen:
674 	ib_destroy_cm_id(priv->cm.id);
675 err_cm:
676 	priv->cm.id = NULL;
677 	return ret;
678 }
679 
680 void ipoib_cm_dev_stop(struct net_device *dev)
681 {
682 	struct ipoib_dev_priv *priv = netdev_priv(dev);
683 	struct ipoib_cm_rx *p, *n;
684 	unsigned long begin;
685 	LIST_HEAD(list);
686 	int ret;
687 
688 	if (!IPOIB_CM_SUPPORTED(dev->dev_addr) || !priv->cm.id)
689 		return;
690 
691 	ib_destroy_cm_id(priv->cm.id);
692 	priv->cm.id = NULL;
693 
694 	spin_lock_irq(&priv->lock);
695 	while (!list_empty(&priv->cm.passive_ids)) {
696 		p = list_entry(priv->cm.passive_ids.next, typeof(*p), list);
697 		list_move(&p->list, &priv->cm.rx_error_list);
698 		p->state = IPOIB_CM_RX_ERROR;
699 		spin_unlock_irq(&priv->lock);
700 		ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
701 		if (ret)
702 			ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
703 		spin_lock_irq(&priv->lock);
704 	}
705 
706 	/* Wait for all RX to be drained */
707 	begin = jiffies;
708 
709 	while (!list_empty(&priv->cm.rx_error_list) ||
710 	       !list_empty(&priv->cm.rx_flush_list) ||
711 	       !list_empty(&priv->cm.rx_drain_list)) {
712 		if (time_after(jiffies, begin + 5 * HZ)) {
713 			ipoib_warn(priv, "RX drain timing out\n");
714 
715 			/*
716 			 * assume the HW is wedged and just free up everything.
717 			 */
718 			list_splice_init(&priv->cm.rx_flush_list, &list);
719 			list_splice_init(&priv->cm.rx_error_list, &list);
720 			list_splice_init(&priv->cm.rx_drain_list, &list);
721 			break;
722 		}
723 		spin_unlock_irq(&priv->lock);
724 		msleep(1);
725 		ipoib_drain_cq(dev);
726 		spin_lock_irq(&priv->lock);
727 	}
728 
729 	list_splice_init(&priv->cm.rx_reap_list, &list);
730 
731 	spin_unlock_irq(&priv->lock);
732 
733 	list_for_each_entry_safe(p, n, &list, list) {
734 		ib_destroy_cm_id(p->id);
735 		ib_destroy_qp(p->qp);
736 		kfree(p);
737 	}
738 
739 	cancel_delayed_work(&priv->cm.stale_task);
740 }
741 
742 static int ipoib_cm_rep_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
743 {
744 	struct ipoib_cm_tx *p = cm_id->context;
745 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
746 	struct ipoib_cm_data *data = event->private_data;
747 	struct sk_buff_head skqueue;
748 	struct ib_qp_attr qp_attr;
749 	int qp_attr_mask, ret;
750 	struct sk_buff *skb;
751 
752 	p->mtu = be32_to_cpu(data->mtu);
753 
754 	if (p->mtu <= IPOIB_ENCAP_LEN) {
755 		ipoib_warn(priv, "Rejecting connection: mtu %d <= %d\n",
756 			   p->mtu, IPOIB_ENCAP_LEN);
757 		return -EINVAL;
758 	}
759 
760 	qp_attr.qp_state = IB_QPS_RTR;
761 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
762 	if (ret) {
763 		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
764 		return ret;
765 	}
766 
767 	qp_attr.rq_psn = 0 /* FIXME */;
768 	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
769 	if (ret) {
770 		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
771 		return ret;
772 	}
773 
774 	qp_attr.qp_state = IB_QPS_RTS;
775 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
776 	if (ret) {
777 		ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret);
778 		return ret;
779 	}
780 	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
781 	if (ret) {
782 		ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret);
783 		return ret;
784 	}
785 
786 	skb_queue_head_init(&skqueue);
787 
788 	spin_lock_irq(&priv->lock);
789 	set_bit(IPOIB_FLAG_OPER_UP, &p->flags);
790 	if (p->neigh)
791 		while ((skb = __skb_dequeue(&p->neigh->queue)))
792 			__skb_queue_tail(&skqueue, skb);
793 	spin_unlock_irq(&priv->lock);
794 
795 	while ((skb = __skb_dequeue(&skqueue))) {
796 		skb->dev = p->dev;
797 		if (dev_queue_xmit(skb))
798 			ipoib_warn(priv, "dev_queue_xmit failed "
799 				   "to requeue packet\n");
800 	}
801 
802 	ret = ib_send_cm_rtu(cm_id, NULL, 0);
803 	if (ret) {
804 		ipoib_warn(priv, "failed to send RTU: %d\n", ret);
805 		return ret;
806 	}
807 	return 0;
808 }
809 
810 static struct ib_qp *ipoib_cm_create_tx_qp(struct net_device *dev, struct ib_cq *cq)
811 {
812 	struct ipoib_dev_priv *priv = netdev_priv(dev);
813 	struct ib_qp_init_attr attr = {};
814 	attr.recv_cq = priv->cq;
815 	attr.srq = priv->cm.srq;
816 	attr.cap.max_send_wr = ipoib_sendq_size;
817 	attr.cap.max_send_sge = 1;
818 	attr.sq_sig_type = IB_SIGNAL_ALL_WR;
819 	attr.qp_type = IB_QPT_RC;
820 	attr.send_cq = cq;
821 	return ib_create_qp(priv->pd, &attr);
822 }
823 
824 static int ipoib_cm_send_req(struct net_device *dev,
825 			     struct ib_cm_id *id, struct ib_qp *qp,
826 			     u32 qpn,
827 			     struct ib_sa_path_rec *pathrec)
828 {
829 	struct ipoib_dev_priv *priv = netdev_priv(dev);
830 	struct ipoib_cm_data data = {};
831 	struct ib_cm_req_param req = {};
832 
833 	data.qpn = cpu_to_be32(priv->qp->qp_num);
834 	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
835 
836 	req.primary_path 	      = pathrec;
837 	req.alternate_path 	      = NULL;
838 	req.service_id                = cpu_to_be64(IPOIB_CM_IETF_ID | qpn);
839 	req.qp_num 		      = qp->qp_num;
840 	req.qp_type 		      = qp->qp_type;
841 	req.private_data 	      = &data;
842 	req.private_data_len 	      = sizeof data;
843 	req.flow_control 	      = 0;
844 
845 	req.starting_psn              = 0; /* FIXME */
846 
847 	/*
848 	 * Pick some arbitrary defaults here; we could make these
849 	 * module parameters if anyone cared about setting them.
850 	 */
851 	req.responder_resources	      = 4;
852 	req.remote_cm_response_timeout = 20;
853 	req.local_cm_response_timeout  = 20;
854 	req.retry_count 	      = 0; /* RFC draft warns against retries */
855 	req.rnr_retry_count 	      = 0; /* RFC draft warns against retries */
856 	req.max_cm_retries 	      = 15;
857 	req.srq 	              = 1;
858 	return ib_send_cm_req(id, &req);
859 }
860 
861 static int ipoib_cm_modify_tx_init(struct net_device *dev,
862 				  struct ib_cm_id *cm_id, struct ib_qp *qp)
863 {
864 	struct ipoib_dev_priv *priv = netdev_priv(dev);
865 	struct ib_qp_attr qp_attr;
866 	int qp_attr_mask, ret;
867 	ret = ib_find_cached_pkey(priv->ca, priv->port, priv->pkey, &qp_attr.pkey_index);
868 	if (ret) {
869 		ipoib_warn(priv, "pkey 0x%x not in cache: %d\n", priv->pkey, ret);
870 		return ret;
871 	}
872 
873 	qp_attr.qp_state = IB_QPS_INIT;
874 	qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE;
875 	qp_attr.port_num = priv->port;
876 	qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PKEY_INDEX | IB_QP_PORT;
877 
878 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
879 	if (ret) {
880 		ipoib_warn(priv, "failed to modify tx QP to INIT: %d\n", ret);
881 		return ret;
882 	}
883 	return 0;
884 }
885 
886 static int ipoib_cm_tx_init(struct ipoib_cm_tx *p, u32 qpn,
887 			    struct ib_sa_path_rec *pathrec)
888 {
889 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
890 	int ret;
891 
892 	p->tx_ring = kzalloc(ipoib_sendq_size * sizeof *p->tx_ring,
893 				GFP_KERNEL);
894 	if (!p->tx_ring) {
895 		ipoib_warn(priv, "failed to allocate tx ring\n");
896 		ret = -ENOMEM;
897 		goto err_tx;
898 	}
899 
900 	p->cq = ib_create_cq(priv->ca, ipoib_cm_tx_completion, NULL, p,
901 			     ipoib_sendq_size + 1, 0);
902 	if (IS_ERR(p->cq)) {
903 		ret = PTR_ERR(p->cq);
904 		ipoib_warn(priv, "failed to allocate tx cq: %d\n", ret);
905 		goto err_cq;
906 	}
907 
908 	ret = ib_req_notify_cq(p->cq, IB_CQ_NEXT_COMP);
909 	if (ret) {
910 		ipoib_warn(priv, "failed to request completion notification: %d\n", ret);
911 		goto err_req_notify;
912 	}
913 
914 	p->qp = ipoib_cm_create_tx_qp(p->dev, p->cq);
915 	if (IS_ERR(p->qp)) {
916 		ret = PTR_ERR(p->qp);
917 		ipoib_warn(priv, "failed to allocate tx qp: %d\n", ret);
918 		goto err_qp;
919 	}
920 
921 	p->id = ib_create_cm_id(priv->ca, ipoib_cm_tx_handler, p);
922 	if (IS_ERR(p->id)) {
923 		ret = PTR_ERR(p->id);
924 		ipoib_warn(priv, "failed to create tx cm id: %d\n", ret);
925 		goto err_id;
926 	}
927 
928 	ret = ipoib_cm_modify_tx_init(p->dev, p->id,  p->qp);
929 	if (ret) {
930 		ipoib_warn(priv, "failed to modify tx qp to rtr: %d\n", ret);
931 		goto err_modify;
932 	}
933 
934 	ret = ipoib_cm_send_req(p->dev, p->id, p->qp, qpn, pathrec);
935 	if (ret) {
936 		ipoib_warn(priv, "failed to send cm req: %d\n", ret);
937 		goto err_send_cm;
938 	}
939 
940 	ipoib_dbg(priv, "Request connection 0x%x for gid " IPOIB_GID_FMT " qpn 0x%x\n",
941 		  p->qp->qp_num, IPOIB_GID_ARG(pathrec->dgid), qpn);
942 
943 	return 0;
944 
945 err_send_cm:
946 err_modify:
947 	ib_destroy_cm_id(p->id);
948 err_id:
949 	p->id = NULL;
950 	ib_destroy_qp(p->qp);
951 err_req_notify:
952 err_qp:
953 	p->qp = NULL;
954 	ib_destroy_cq(p->cq);
955 err_cq:
956 	p->cq = NULL;
957 err_tx:
958 	return ret;
959 }
960 
961 static void ipoib_cm_tx_destroy(struct ipoib_cm_tx *p)
962 {
963 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
964 	struct ipoib_tx_buf *tx_req;
965 
966 	ipoib_dbg(priv, "Destroy active connection 0x%x head 0x%x tail 0x%x\n",
967 		  p->qp ? p->qp->qp_num : 0, p->tx_head, p->tx_tail);
968 
969 	if (p->id)
970 		ib_destroy_cm_id(p->id);
971 
972 	if (p->qp)
973 		ib_destroy_qp(p->qp);
974 
975 	if (p->cq)
976 		ib_destroy_cq(p->cq);
977 
978 	if (test_bit(IPOIB_FLAG_NETIF_STOPPED, &p->flags))
979 		netif_wake_queue(p->dev);
980 
981 	if (p->tx_ring) {
982 		while ((int) p->tx_tail - (int) p->tx_head < 0) {
983 			tx_req = &p->tx_ring[p->tx_tail & (ipoib_sendq_size - 1)];
984 			ib_dma_unmap_single(priv->ca, tx_req->mapping, tx_req->skb->len,
985 					 DMA_TO_DEVICE);
986 			dev_kfree_skb_any(tx_req->skb);
987 			++p->tx_tail;
988 		}
989 
990 		kfree(p->tx_ring);
991 	}
992 
993 	kfree(p);
994 }
995 
996 static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
997 			       struct ib_cm_event *event)
998 {
999 	struct ipoib_cm_tx *tx = cm_id->context;
1000 	struct ipoib_dev_priv *priv = netdev_priv(tx->dev);
1001 	struct net_device *dev = priv->dev;
1002 	struct ipoib_neigh *neigh;
1003 	int ret;
1004 
1005 	switch (event->event) {
1006 	case IB_CM_DREQ_RECEIVED:
1007 		ipoib_dbg(priv, "DREQ received.\n");
1008 		ib_send_cm_drep(cm_id, NULL, 0);
1009 		break;
1010 	case IB_CM_REP_RECEIVED:
1011 		ipoib_dbg(priv, "REP received.\n");
1012 		ret = ipoib_cm_rep_handler(cm_id, event);
1013 		if (ret)
1014 			ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,
1015 				       NULL, 0, NULL, 0);
1016 		break;
1017 	case IB_CM_REQ_ERROR:
1018 	case IB_CM_REJ_RECEIVED:
1019 	case IB_CM_TIMEWAIT_EXIT:
1020 		ipoib_dbg(priv, "CM error %d.\n", event->event);
1021 		spin_lock_irq(&priv->tx_lock);
1022 		spin_lock(&priv->lock);
1023 		neigh = tx->neigh;
1024 
1025 		if (neigh) {
1026 			neigh->cm = NULL;
1027 			list_del(&neigh->list);
1028 			if (neigh->ah)
1029 				ipoib_put_ah(neigh->ah);
1030 			ipoib_neigh_free(dev, neigh);
1031 
1032 			tx->neigh = NULL;
1033 		}
1034 
1035 		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
1036 			list_move(&tx->list, &priv->cm.reap_list);
1037 			queue_work(ipoib_workqueue, &priv->cm.reap_task);
1038 		}
1039 
1040 		spin_unlock(&priv->lock);
1041 		spin_unlock_irq(&priv->tx_lock);
1042 		break;
1043 	default:
1044 		break;
1045 	}
1046 
1047 	return 0;
1048 }
1049 
1050 struct ipoib_cm_tx *ipoib_cm_create_tx(struct net_device *dev, struct ipoib_path *path,
1051 				       struct ipoib_neigh *neigh)
1052 {
1053 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1054 	struct ipoib_cm_tx *tx;
1055 
1056 	tx = kzalloc(sizeof *tx, GFP_ATOMIC);
1057 	if (!tx)
1058 		return NULL;
1059 
1060 	neigh->cm = tx;
1061 	tx->neigh = neigh;
1062 	tx->path = path;
1063 	tx->dev = dev;
1064 	list_add(&tx->list, &priv->cm.start_list);
1065 	set_bit(IPOIB_FLAG_INITIALIZED, &tx->flags);
1066 	queue_work(ipoib_workqueue, &priv->cm.start_task);
1067 	return tx;
1068 }
1069 
1070 void ipoib_cm_destroy_tx(struct ipoib_cm_tx *tx)
1071 {
1072 	struct ipoib_dev_priv *priv = netdev_priv(tx->dev);
1073 	if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
1074 		list_move(&tx->list, &priv->cm.reap_list);
1075 		queue_work(ipoib_workqueue, &priv->cm.reap_task);
1076 		ipoib_dbg(priv, "Reap connection for gid " IPOIB_GID_FMT "\n",
1077 			  IPOIB_GID_ARG(tx->neigh->dgid));
1078 		tx->neigh = NULL;
1079 	}
1080 }
1081 
1082 static void ipoib_cm_tx_start(struct work_struct *work)
1083 {
1084 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1085 						   cm.start_task);
1086 	struct net_device *dev = priv->dev;
1087 	struct ipoib_neigh *neigh;
1088 	struct ipoib_cm_tx *p;
1089 	unsigned long flags;
1090 	int ret;
1091 
1092 	struct ib_sa_path_rec pathrec;
1093 	u32 qpn;
1094 
1095 	spin_lock_irqsave(&priv->tx_lock, flags);
1096 	spin_lock(&priv->lock);
1097 	while (!list_empty(&priv->cm.start_list)) {
1098 		p = list_entry(priv->cm.start_list.next, typeof(*p), list);
1099 		list_del_init(&p->list);
1100 		neigh = p->neigh;
1101 		qpn = IPOIB_QPN(neigh->neighbour->ha);
1102 		memcpy(&pathrec, &p->path->pathrec, sizeof pathrec);
1103 		spin_unlock(&priv->lock);
1104 		spin_unlock_irqrestore(&priv->tx_lock, flags);
1105 		ret = ipoib_cm_tx_init(p, qpn, &pathrec);
1106 		spin_lock_irqsave(&priv->tx_lock, flags);
1107 		spin_lock(&priv->lock);
1108 		if (ret) {
1109 			neigh = p->neigh;
1110 			if (neigh) {
1111 				neigh->cm = NULL;
1112 				list_del(&neigh->list);
1113 				if (neigh->ah)
1114 					ipoib_put_ah(neigh->ah);
1115 				ipoib_neigh_free(dev, neigh);
1116 			}
1117 			list_del(&p->list);
1118 			kfree(p);
1119 		}
1120 	}
1121 	spin_unlock(&priv->lock);
1122 	spin_unlock_irqrestore(&priv->tx_lock, flags);
1123 }
1124 
1125 static void ipoib_cm_tx_reap(struct work_struct *work)
1126 {
1127 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1128 						   cm.reap_task);
1129 	struct ipoib_cm_tx *p;
1130 
1131 	spin_lock_irq(&priv->tx_lock);
1132 	spin_lock(&priv->lock);
1133 	while (!list_empty(&priv->cm.reap_list)) {
1134 		p = list_entry(priv->cm.reap_list.next, typeof(*p), list);
1135 		list_del(&p->list);
1136 		spin_unlock(&priv->lock);
1137 		spin_unlock_irq(&priv->tx_lock);
1138 		ipoib_cm_tx_destroy(p);
1139 		spin_lock_irq(&priv->tx_lock);
1140 		spin_lock(&priv->lock);
1141 	}
1142 	spin_unlock(&priv->lock);
1143 	spin_unlock_irq(&priv->tx_lock);
1144 }
1145 
1146 static void ipoib_cm_skb_reap(struct work_struct *work)
1147 {
1148 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1149 						   cm.skb_task);
1150 	struct sk_buff *skb;
1151 
1152 	unsigned mtu = priv->mcast_mtu;
1153 
1154 	spin_lock_irq(&priv->tx_lock);
1155 	spin_lock(&priv->lock);
1156 	while ((skb = skb_dequeue(&priv->cm.skb_queue))) {
1157 		spin_unlock(&priv->lock);
1158 		spin_unlock_irq(&priv->tx_lock);
1159 		if (skb->protocol == htons(ETH_P_IP))
1160 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
1161 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1162 		else if (skb->protocol == htons(ETH_P_IPV6))
1163 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, priv->dev);
1164 #endif
1165 		dev_kfree_skb_any(skb);
1166 		spin_lock_irq(&priv->tx_lock);
1167 		spin_lock(&priv->lock);
1168 	}
1169 	spin_unlock(&priv->lock);
1170 	spin_unlock_irq(&priv->tx_lock);
1171 }
1172 
1173 void ipoib_cm_skb_too_long(struct net_device* dev, struct sk_buff *skb,
1174 			   unsigned int mtu)
1175 {
1176 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1177 	int e = skb_queue_empty(&priv->cm.skb_queue);
1178 
1179 	if (skb->dst)
1180 		skb->dst->ops->update_pmtu(skb->dst, mtu);
1181 
1182 	skb_queue_tail(&priv->cm.skb_queue, skb);
1183 	if (e)
1184 		queue_work(ipoib_workqueue, &priv->cm.skb_task);
1185 }
1186 
1187 static void ipoib_cm_rx_reap(struct work_struct *work)
1188 {
1189 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1190 						   cm.rx_reap_task);
1191 	struct ipoib_cm_rx *p, *n;
1192 	LIST_HEAD(list);
1193 
1194 	spin_lock_irq(&priv->lock);
1195 	list_splice_init(&priv->cm.rx_reap_list, &list);
1196 	spin_unlock_irq(&priv->lock);
1197 
1198 	list_for_each_entry_safe(p, n, &list, list) {
1199 		ib_destroy_cm_id(p->id);
1200 		ib_destroy_qp(p->qp);
1201 		kfree(p);
1202 	}
1203 }
1204 
1205 static void ipoib_cm_stale_task(struct work_struct *work)
1206 {
1207 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1208 						   cm.stale_task.work);
1209 	struct ipoib_cm_rx *p;
1210 	int ret;
1211 
1212 	spin_lock_irq(&priv->lock);
1213 	while (!list_empty(&priv->cm.passive_ids)) {
1214 		/* List is sorted by LRU, start from tail,
1215 		 * stop when we see a recently used entry */
1216 		p = list_entry(priv->cm.passive_ids.prev, typeof(*p), list);
1217 		if (time_before_eq(jiffies, p->jiffies + IPOIB_CM_RX_TIMEOUT))
1218 			break;
1219 		list_move(&p->list, &priv->cm.rx_error_list);
1220 		p->state = IPOIB_CM_RX_ERROR;
1221 		spin_unlock_irq(&priv->lock);
1222 		ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
1223 		if (ret)
1224 			ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
1225 		spin_lock_irq(&priv->lock);
1226 	}
1227 
1228 	if (!list_empty(&priv->cm.passive_ids))
1229 		queue_delayed_work(ipoib_workqueue,
1230 				   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
1231 	spin_unlock_irq(&priv->lock);
1232 }
1233 
1234 
1235 static ssize_t show_mode(struct device *d, struct device_attribute *attr,
1236 			 char *buf)
1237 {
1238 	struct ipoib_dev_priv *priv = netdev_priv(to_net_dev(d));
1239 
1240 	if (test_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags))
1241 		return sprintf(buf, "connected\n");
1242 	else
1243 		return sprintf(buf, "datagram\n");
1244 }
1245 
1246 static ssize_t set_mode(struct device *d, struct device_attribute *attr,
1247 			const char *buf, size_t count)
1248 {
1249 	struct net_device *dev = to_net_dev(d);
1250 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1251 
1252 	/* flush paths if we switch modes so that connections are restarted */
1253 	if (IPOIB_CM_SUPPORTED(dev->dev_addr) && !strcmp(buf, "connected\n")) {
1254 		set_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags);
1255 		ipoib_warn(priv, "enabling connected mode "
1256 			   "will cause multicast packet drops\n");
1257 		ipoib_flush_paths(dev);
1258 		return count;
1259 	}
1260 
1261 	if (!strcmp(buf, "datagram\n")) {
1262 		clear_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags);
1263 		dev->mtu = min(priv->mcast_mtu, dev->mtu);
1264 		ipoib_flush_paths(dev);
1265 		return count;
1266 	}
1267 
1268 	return -EINVAL;
1269 }
1270 
1271 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, show_mode, set_mode);
1272 
1273 int ipoib_cm_add_mode_attr(struct net_device *dev)
1274 {
1275 	return device_create_file(&dev->dev, &dev_attr_mode);
1276 }
1277 
1278 int ipoib_cm_dev_init(struct net_device *dev)
1279 {
1280 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1281 	struct ib_srq_init_attr srq_init_attr = {
1282 		.attr = {
1283 			.max_wr  = ipoib_recvq_size,
1284 			.max_sge = IPOIB_CM_RX_SG
1285 		}
1286 	};
1287 	int ret, i;
1288 
1289 	INIT_LIST_HEAD(&priv->cm.passive_ids);
1290 	INIT_LIST_HEAD(&priv->cm.reap_list);
1291 	INIT_LIST_HEAD(&priv->cm.start_list);
1292 	INIT_LIST_HEAD(&priv->cm.rx_error_list);
1293 	INIT_LIST_HEAD(&priv->cm.rx_flush_list);
1294 	INIT_LIST_HEAD(&priv->cm.rx_drain_list);
1295 	INIT_LIST_HEAD(&priv->cm.rx_reap_list);
1296 	INIT_WORK(&priv->cm.start_task, ipoib_cm_tx_start);
1297 	INIT_WORK(&priv->cm.reap_task, ipoib_cm_tx_reap);
1298 	INIT_WORK(&priv->cm.skb_task, ipoib_cm_skb_reap);
1299 	INIT_WORK(&priv->cm.rx_reap_task, ipoib_cm_rx_reap);
1300 	INIT_DELAYED_WORK(&priv->cm.stale_task, ipoib_cm_stale_task);
1301 
1302 	skb_queue_head_init(&priv->cm.skb_queue);
1303 
1304 	priv->cm.srq = ib_create_srq(priv->pd, &srq_init_attr);
1305 	if (IS_ERR(priv->cm.srq)) {
1306 		ret = PTR_ERR(priv->cm.srq);
1307 		priv->cm.srq = NULL;
1308 		return ret;
1309 	}
1310 
1311 	priv->cm.srq_ring = kzalloc(ipoib_recvq_size * sizeof *priv->cm.srq_ring,
1312 				    GFP_KERNEL);
1313 	if (!priv->cm.srq_ring) {
1314 		printk(KERN_WARNING "%s: failed to allocate CM ring (%d entries)\n",
1315 		       priv->ca->name, ipoib_recvq_size);
1316 		ipoib_cm_dev_cleanup(dev);
1317 		return -ENOMEM;
1318 	}
1319 
1320 	for (i = 0; i < IPOIB_CM_RX_SG; ++i)
1321 		priv->cm.rx_sge[i].lkey	= priv->mr->lkey;
1322 
1323 	priv->cm.rx_sge[0].length = IPOIB_CM_HEAD_SIZE;
1324 	for (i = 1; i < IPOIB_CM_RX_SG; ++i)
1325 		priv->cm.rx_sge[i].length = PAGE_SIZE;
1326 	priv->cm.rx_wr.next = NULL;
1327 	priv->cm.rx_wr.sg_list = priv->cm.rx_sge;
1328 	priv->cm.rx_wr.num_sge = IPOIB_CM_RX_SG;
1329 
1330 	for (i = 0; i < ipoib_recvq_size; ++i) {
1331 		if (!ipoib_cm_alloc_rx_skb(dev, i, IPOIB_CM_RX_SG - 1,
1332 					   priv->cm.srq_ring[i].mapping)) {
1333 			ipoib_warn(priv, "failed to allocate receive buffer %d\n", i);
1334 			ipoib_cm_dev_cleanup(dev);
1335 			return -ENOMEM;
1336 		}
1337 		if (ipoib_cm_post_receive(dev, i)) {
1338 			ipoib_warn(priv, "ipoib_ib_post_receive failed for buf %d\n", i);
1339 			ipoib_cm_dev_cleanup(dev);
1340 			return -EIO;
1341 		}
1342 	}
1343 
1344 	priv->dev->dev_addr[0] = IPOIB_FLAGS_RC;
1345 	return 0;
1346 }
1347 
1348 void ipoib_cm_dev_cleanup(struct net_device *dev)
1349 {
1350 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1351 	int i, ret;
1352 
1353 	if (!priv->cm.srq)
1354 		return;
1355 
1356 	ipoib_dbg(priv, "Cleanup ipoib connected mode.\n");
1357 
1358 	ret = ib_destroy_srq(priv->cm.srq);
1359 	if (ret)
1360 		ipoib_warn(priv, "ib_destroy_srq failed: %d\n", ret);
1361 
1362 	priv->cm.srq = NULL;
1363 	if (!priv->cm.srq_ring)
1364 		return;
1365 	for (i = 0; i < ipoib_recvq_size; ++i)
1366 		if (priv->cm.srq_ring[i].skb) {
1367 			ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
1368 					      priv->cm.srq_ring[i].mapping);
1369 			dev_kfree_skb_any(priv->cm.srq_ring[i].skb);
1370 			priv->cm.srq_ring[i].skb = NULL;
1371 		}
1372 	kfree(priv->cm.srq_ring);
1373 	priv->cm.srq_ring = NULL;
1374 }
1375