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 #include <linux/vmalloc.h>
42 
43 #include "ipoib.h"
44 
45 int ipoib_max_conn_qp = 128;
46 
47 module_param_named(max_nonsrq_conn_qp, ipoib_max_conn_qp, int, 0444);
48 MODULE_PARM_DESC(max_nonsrq_conn_qp,
49 		 "Max number of connected-mode QPs per interface "
50 		 "(applied only if shared receive queue is not available)");
51 
52 #ifdef CONFIG_INFINIBAND_IPOIB_DEBUG_DATA
53 static int data_debug_level;
54 
55 module_param_named(cm_data_debug_level, data_debug_level, int, 0644);
56 MODULE_PARM_DESC(cm_data_debug_level,
57 		 "Enable data path debug tracing for connected mode if > 0");
58 #endif
59 
60 #define IPOIB_CM_IETF_ID 0x1000000000000000ULL
61 
62 #define IPOIB_CM_RX_UPDATE_TIME (256 * HZ)
63 #define IPOIB_CM_RX_TIMEOUT     (2 * 256 * HZ)
64 #define IPOIB_CM_RX_DELAY       (3 * 256 * HZ)
65 #define IPOIB_CM_RX_UPDATE_MASK (0x3)
66 
67 static struct ib_qp_attr ipoib_cm_err_attr = {
68 	.qp_state = IB_QPS_ERR
69 };
70 
71 #define IPOIB_CM_RX_DRAIN_WRID 0xffffffff
72 
73 static struct ib_send_wr ipoib_cm_rx_drain_wr = {
74 	.wr_id = IPOIB_CM_RX_DRAIN_WRID,
75 	.opcode = IB_WR_SEND,
76 };
77 
78 static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
79 			       struct ib_cm_event *event);
80 
81 static void ipoib_cm_dma_unmap_rx(struct ipoib_dev_priv *priv, int frags,
82 				  u64 mapping[IPOIB_CM_RX_SG])
83 {
84 	int i;
85 
86 	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
87 
88 	for (i = 0; i < frags; ++i)
89 		ib_dma_unmap_single(priv->ca, mapping[i + 1], PAGE_SIZE, DMA_FROM_DEVICE);
90 }
91 
92 static int ipoib_cm_post_receive_srq(struct net_device *dev, int id)
93 {
94 	struct ipoib_dev_priv *priv = netdev_priv(dev);
95 	struct ib_recv_wr *bad_wr;
96 	int i, ret;
97 
98 	priv->cm.rx_wr.wr_id = id | IPOIB_OP_CM | IPOIB_OP_RECV;
99 
100 	for (i = 0; i < priv->cm.num_frags; ++i)
101 		priv->cm.rx_sge[i].addr = priv->cm.srq_ring[id].mapping[i];
102 
103 	ret = ib_post_srq_recv(priv->cm.srq, &priv->cm.rx_wr, &bad_wr);
104 	if (unlikely(ret)) {
105 		ipoib_warn(priv, "post srq failed for buf %d (%d)\n", id, ret);
106 		ipoib_cm_dma_unmap_rx(priv, priv->cm.num_frags - 1,
107 				      priv->cm.srq_ring[id].mapping);
108 		dev_kfree_skb_any(priv->cm.srq_ring[id].skb);
109 		priv->cm.srq_ring[id].skb = NULL;
110 	}
111 
112 	return ret;
113 }
114 
115 static int ipoib_cm_post_receive_nonsrq(struct net_device *dev,
116 					struct ipoib_cm_rx *rx, int id)
117 {
118 	struct ipoib_dev_priv *priv = netdev_priv(dev);
119 	struct ib_recv_wr *bad_wr;
120 	int i, ret;
121 
122 	priv->cm.rx_wr.wr_id = id | IPOIB_OP_CM | IPOIB_OP_RECV;
123 
124 	for (i = 0; i < IPOIB_CM_RX_SG; ++i)
125 		priv->cm.rx_sge[i].addr = rx->rx_ring[id].mapping[i];
126 
127 	ret = ib_post_recv(rx->qp, &priv->cm.rx_wr, &bad_wr);
128 	if (unlikely(ret)) {
129 		ipoib_warn(priv, "post recv failed for buf %d (%d)\n", id, ret);
130 		ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
131 				      rx->rx_ring[id].mapping);
132 		dev_kfree_skb_any(rx->rx_ring[id].skb);
133 		rx->rx_ring[id].skb = NULL;
134 	}
135 
136 	return ret;
137 }
138 
139 static struct sk_buff *ipoib_cm_alloc_rx_skb(struct net_device *dev,
140 					     struct ipoib_cm_rx_buf *rx_ring,
141 					     int id, int frags,
142 					     u64 mapping[IPOIB_CM_RX_SG])
143 {
144 	struct ipoib_dev_priv *priv = netdev_priv(dev);
145 	struct sk_buff *skb;
146 	int i;
147 
148 	skb = dev_alloc_skb(IPOIB_CM_HEAD_SIZE + 12);
149 	if (unlikely(!skb))
150 		return NULL;
151 
152 	/*
153 	 * IPoIB adds a 4 byte header. So we need 12 more bytes to align the
154 	 * IP header to a multiple of 16.
155 	 */
156 	skb_reserve(skb, 12);
157 
158 	mapping[0] = ib_dma_map_single(priv->ca, skb->data, IPOIB_CM_HEAD_SIZE,
159 				       DMA_FROM_DEVICE);
160 	if (unlikely(ib_dma_mapping_error(priv->ca, mapping[0]))) {
161 		dev_kfree_skb_any(skb);
162 		return NULL;
163 	}
164 
165 	for (i = 0; i < frags; i++) {
166 		struct page *page = alloc_page(GFP_ATOMIC);
167 
168 		if (!page)
169 			goto partial_error;
170 		skb_fill_page_desc(skb, i, page, 0, PAGE_SIZE);
171 
172 		mapping[i + 1] = ib_dma_map_page(priv->ca, skb_shinfo(skb)->frags[i].page,
173 						 0, PAGE_SIZE, DMA_FROM_DEVICE);
174 		if (unlikely(ib_dma_mapping_error(priv->ca, mapping[i + 1])))
175 			goto partial_error;
176 	}
177 
178 	rx_ring[id].skb = skb;
179 	return skb;
180 
181 partial_error:
182 
183 	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
184 
185 	for (; i > 0; --i)
186 		ib_dma_unmap_single(priv->ca, mapping[i], PAGE_SIZE, DMA_FROM_DEVICE);
187 
188 	dev_kfree_skb_any(skb);
189 	return NULL;
190 }
191 
192 static void ipoib_cm_free_rx_ring(struct net_device *dev,
193 				  struct ipoib_cm_rx_buf *rx_ring)
194 {
195 	struct ipoib_dev_priv *priv = netdev_priv(dev);
196 	int i;
197 
198 	for (i = 0; i < ipoib_recvq_size; ++i)
199 		if (rx_ring[i].skb) {
200 			ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
201 					      rx_ring[i].mapping);
202 			dev_kfree_skb_any(rx_ring[i].skb);
203 		}
204 
205 	kfree(rx_ring);
206 }
207 
208 static void ipoib_cm_start_rx_drain(struct ipoib_dev_priv *priv)
209 {
210 	struct ib_send_wr *bad_wr;
211 	struct ipoib_cm_rx *p;
212 
213 	/* We only reserved 1 extra slot in CQ for drain WRs, so
214 	 * make sure we have at most 1 outstanding WR. */
215 	if (list_empty(&priv->cm.rx_flush_list) ||
216 	    !list_empty(&priv->cm.rx_drain_list))
217 		return;
218 
219 	/*
220 	 * QPs on flush list are error state.  This way, a "flush
221 	 * error" WC will be immediately generated for each WR we post.
222 	 */
223 	p = list_entry(priv->cm.rx_flush_list.next, typeof(*p), list);
224 	if (ib_post_send(p->qp, &ipoib_cm_rx_drain_wr, &bad_wr))
225 		ipoib_warn(priv, "failed to post drain wr\n");
226 
227 	list_splice_init(&priv->cm.rx_flush_list, &priv->cm.rx_drain_list);
228 }
229 
230 static void ipoib_cm_rx_event_handler(struct ib_event *event, void *ctx)
231 {
232 	struct ipoib_cm_rx *p = ctx;
233 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
234 	unsigned long flags;
235 
236 	if (event->event != IB_EVENT_QP_LAST_WQE_REACHED)
237 		return;
238 
239 	spin_lock_irqsave(&priv->lock, flags);
240 	list_move(&p->list, &priv->cm.rx_flush_list);
241 	p->state = IPOIB_CM_RX_FLUSH;
242 	ipoib_cm_start_rx_drain(priv);
243 	spin_unlock_irqrestore(&priv->lock, flags);
244 }
245 
246 static struct ib_qp *ipoib_cm_create_rx_qp(struct net_device *dev,
247 					   struct ipoib_cm_rx *p)
248 {
249 	struct ipoib_dev_priv *priv = netdev_priv(dev);
250 	struct ib_qp_init_attr attr = {
251 		.event_handler = ipoib_cm_rx_event_handler,
252 		.send_cq = priv->cq, /* For drain WR */
253 		.recv_cq = priv->cq,
254 		.srq = priv->cm.srq,
255 		.cap.max_send_wr = 1, /* For drain WR */
256 		.cap.max_send_sge = 1, /* FIXME: 0 Seems not to work */
257 		.sq_sig_type = IB_SIGNAL_ALL_WR,
258 		.qp_type = IB_QPT_RC,
259 		.qp_context = p,
260 	};
261 
262 	if (!ipoib_cm_has_srq(dev)) {
263 		attr.cap.max_recv_wr  = ipoib_recvq_size;
264 		attr.cap.max_recv_sge = IPOIB_CM_RX_SG;
265 	}
266 
267 	return ib_create_qp(priv->pd, &attr);
268 }
269 
270 static int ipoib_cm_modify_rx_qp(struct net_device *dev,
271 				 struct ib_cm_id *cm_id, struct ib_qp *qp,
272 				 unsigned psn)
273 {
274 	struct ipoib_dev_priv *priv = netdev_priv(dev);
275 	struct ib_qp_attr qp_attr;
276 	int qp_attr_mask, ret;
277 
278 	qp_attr.qp_state = IB_QPS_INIT;
279 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
280 	if (ret) {
281 		ipoib_warn(priv, "failed to init QP attr for INIT: %d\n", ret);
282 		return ret;
283 	}
284 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
285 	if (ret) {
286 		ipoib_warn(priv, "failed to modify QP to INIT: %d\n", ret);
287 		return ret;
288 	}
289 	qp_attr.qp_state = IB_QPS_RTR;
290 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
291 	if (ret) {
292 		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
293 		return ret;
294 	}
295 	qp_attr.rq_psn = psn;
296 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
297 	if (ret) {
298 		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
299 		return ret;
300 	}
301 
302 	/*
303 	 * Current Mellanox HCA firmware won't generate completions
304 	 * with error for drain WRs unless the QP has been moved to
305 	 * RTS first. This work-around leaves a window where a QP has
306 	 * moved to error asynchronously, but this will eventually get
307 	 * fixed in firmware, so let's not error out if modify QP
308 	 * fails.
309 	 */
310 	qp_attr.qp_state = IB_QPS_RTS;
311 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
312 	if (ret) {
313 		ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret);
314 		return 0;
315 	}
316 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
317 	if (ret) {
318 		ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret);
319 		return 0;
320 	}
321 
322 	return 0;
323 }
324 
325 static int ipoib_cm_nonsrq_init_rx(struct net_device *dev, struct ib_cm_id *cm_id,
326 				   struct ipoib_cm_rx *rx)
327 {
328 	struct ipoib_dev_priv *priv = netdev_priv(dev);
329 	int ret;
330 	int i;
331 
332 	rx->rx_ring = kcalloc(ipoib_recvq_size, sizeof *rx->rx_ring, GFP_KERNEL);
333 	if (!rx->rx_ring)
334 		return -ENOMEM;
335 
336 	spin_lock_irq(&priv->lock);
337 
338 	if (priv->cm.nonsrq_conn_qp >= ipoib_max_conn_qp) {
339 		spin_unlock_irq(&priv->lock);
340 		ib_send_cm_rej(cm_id, IB_CM_REJ_NO_QP, NULL, 0, NULL, 0);
341 		ret = -EINVAL;
342 		goto err_free;
343 	} else
344 		++priv->cm.nonsrq_conn_qp;
345 
346 	spin_unlock_irq(&priv->lock);
347 
348 	for (i = 0; i < ipoib_recvq_size; ++i) {
349 		if (!ipoib_cm_alloc_rx_skb(dev, rx->rx_ring, i, IPOIB_CM_RX_SG - 1,
350 					   rx->rx_ring[i].mapping)) {
351 			ipoib_warn(priv, "failed to allocate receive buffer %d\n", i);
352 				ret = -ENOMEM;
353 				goto err_count;
354 			}
355 		ret = ipoib_cm_post_receive_nonsrq(dev, rx, i);
356 		if (ret) {
357 			ipoib_warn(priv, "ipoib_cm_post_receive_nonsrq "
358 				   "failed for buf %d\n", i);
359 			ret = -EIO;
360 			goto err_count;
361 		}
362 	}
363 
364 	rx->recv_count = ipoib_recvq_size;
365 
366 	return 0;
367 
368 err_count:
369 	spin_lock_irq(&priv->lock);
370 	--priv->cm.nonsrq_conn_qp;
371 	spin_unlock_irq(&priv->lock);
372 
373 err_free:
374 	ipoib_cm_free_rx_ring(dev, rx->rx_ring);
375 
376 	return ret;
377 }
378 
379 static int ipoib_cm_send_rep(struct net_device *dev, struct ib_cm_id *cm_id,
380 			     struct ib_qp *qp, struct ib_cm_req_event_param *req,
381 			     unsigned psn)
382 {
383 	struct ipoib_dev_priv *priv = netdev_priv(dev);
384 	struct ipoib_cm_data data = {};
385 	struct ib_cm_rep_param rep = {};
386 
387 	data.qpn = cpu_to_be32(priv->qp->qp_num);
388 	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
389 
390 	rep.private_data = &data;
391 	rep.private_data_len = sizeof data;
392 	rep.flow_control = 0;
393 	rep.rnr_retry_count = req->rnr_retry_count;
394 	rep.srq = ipoib_cm_has_srq(dev);
395 	rep.qp_num = qp->qp_num;
396 	rep.starting_psn = psn;
397 	return ib_send_cm_rep(cm_id, &rep);
398 }
399 
400 static int ipoib_cm_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
401 {
402 	struct net_device *dev = cm_id->context;
403 	struct ipoib_dev_priv *priv = netdev_priv(dev);
404 	struct ipoib_cm_rx *p;
405 	unsigned psn;
406 	int ret;
407 
408 	ipoib_dbg(priv, "REQ arrived\n");
409 	p = kzalloc(sizeof *p, GFP_KERNEL);
410 	if (!p)
411 		return -ENOMEM;
412 	p->dev = dev;
413 	p->id = cm_id;
414 	cm_id->context = p;
415 	p->state = IPOIB_CM_RX_LIVE;
416 	p->jiffies = jiffies;
417 	INIT_LIST_HEAD(&p->list);
418 
419 	p->qp = ipoib_cm_create_rx_qp(dev, p);
420 	if (IS_ERR(p->qp)) {
421 		ret = PTR_ERR(p->qp);
422 		goto err_qp;
423 	}
424 
425 	psn = random32() & 0xffffff;
426 	ret = ipoib_cm_modify_rx_qp(dev, cm_id, p->qp, psn);
427 	if (ret)
428 		goto err_modify;
429 
430 	if (!ipoib_cm_has_srq(dev)) {
431 		ret = ipoib_cm_nonsrq_init_rx(dev, cm_id, p);
432 		if (ret)
433 			goto err_modify;
434 	}
435 
436 	spin_lock_irq(&priv->lock);
437 	queue_delayed_work(ipoib_workqueue,
438 			   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
439 	/* Add this entry to passive ids list head, but do not re-add it
440 	 * if IB_EVENT_QP_LAST_WQE_REACHED has moved it to flush list. */
441 	p->jiffies = jiffies;
442 	if (p->state == IPOIB_CM_RX_LIVE)
443 		list_move(&p->list, &priv->cm.passive_ids);
444 	spin_unlock_irq(&priv->lock);
445 
446 	ret = ipoib_cm_send_rep(dev, cm_id, p->qp, &event->param.req_rcvd, psn);
447 	if (ret) {
448 		ipoib_warn(priv, "failed to send REP: %d\n", ret);
449 		if (ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE))
450 			ipoib_warn(priv, "unable to move qp to error state\n");
451 	}
452 	return 0;
453 
454 err_modify:
455 	ib_destroy_qp(p->qp);
456 err_qp:
457 	kfree(p);
458 	return ret;
459 }
460 
461 static int ipoib_cm_rx_handler(struct ib_cm_id *cm_id,
462 			       struct ib_cm_event *event)
463 {
464 	struct ipoib_cm_rx *p;
465 	struct ipoib_dev_priv *priv;
466 
467 	switch (event->event) {
468 	case IB_CM_REQ_RECEIVED:
469 		return ipoib_cm_req_handler(cm_id, event);
470 	case IB_CM_DREQ_RECEIVED:
471 		p = cm_id->context;
472 		ib_send_cm_drep(cm_id, NULL, 0);
473 		/* Fall through */
474 	case IB_CM_REJ_RECEIVED:
475 		p = cm_id->context;
476 		priv = netdev_priv(p->dev);
477 		if (ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE))
478 			ipoib_warn(priv, "unable to move qp to error state\n");
479 		/* Fall through */
480 	default:
481 		return 0;
482 	}
483 }
484 /* Adjust length of skb with fragments to match received data */
485 static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space,
486 			  unsigned int length, struct sk_buff *toskb)
487 {
488 	int i, num_frags;
489 	unsigned int size;
490 
491 	/* put header into skb */
492 	size = min(length, hdr_space);
493 	skb->tail += size;
494 	skb->len += size;
495 	length -= size;
496 
497 	num_frags = skb_shinfo(skb)->nr_frags;
498 	for (i = 0; i < num_frags; i++) {
499 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
500 
501 		if (length == 0) {
502 			/* don't need this page */
503 			skb_fill_page_desc(toskb, i, frag->page, 0, PAGE_SIZE);
504 			--skb_shinfo(skb)->nr_frags;
505 		} else {
506 			size = min(length, (unsigned) PAGE_SIZE);
507 
508 			frag->size = size;
509 			skb->data_len += size;
510 			skb->truesize += size;
511 			skb->len += size;
512 			length -= size;
513 		}
514 	}
515 }
516 
517 void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
518 {
519 	struct ipoib_dev_priv *priv = netdev_priv(dev);
520 	struct ipoib_cm_rx_buf *rx_ring;
521 	unsigned int wr_id = wc->wr_id & ~(IPOIB_OP_CM | IPOIB_OP_RECV);
522 	struct sk_buff *skb, *newskb;
523 	struct ipoib_cm_rx *p;
524 	unsigned long flags;
525 	u64 mapping[IPOIB_CM_RX_SG];
526 	int frags;
527 	int has_srq;
528 
529 	ipoib_dbg_data(priv, "cm recv completion: id %d, status: %d\n",
530 		       wr_id, wc->status);
531 
532 	if (unlikely(wr_id >= ipoib_recvq_size)) {
533 		if (wr_id == (IPOIB_CM_RX_DRAIN_WRID & ~(IPOIB_OP_CM | IPOIB_OP_RECV))) {
534 			spin_lock_irqsave(&priv->lock, flags);
535 			list_splice_init(&priv->cm.rx_drain_list, &priv->cm.rx_reap_list);
536 			ipoib_cm_start_rx_drain(priv);
537 			queue_work(ipoib_workqueue, &priv->cm.rx_reap_task);
538 			spin_unlock_irqrestore(&priv->lock, flags);
539 		} else
540 			ipoib_warn(priv, "cm recv completion event with wrid %d (> %d)\n",
541 				   wr_id, ipoib_recvq_size);
542 		return;
543 	}
544 
545 	p = wc->qp->qp_context;
546 
547 	has_srq = ipoib_cm_has_srq(dev);
548 	rx_ring = has_srq ? priv->cm.srq_ring : p->rx_ring;
549 
550 	skb = rx_ring[wr_id].skb;
551 
552 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
553 		ipoib_dbg(priv, "cm recv error "
554 			   "(status=%d, wrid=%d vend_err %x)\n",
555 			   wc->status, wr_id, wc->vendor_err);
556 		++dev->stats.rx_dropped;
557 		if (has_srq)
558 			goto repost;
559 		else {
560 			if (!--p->recv_count) {
561 				spin_lock_irqsave(&priv->lock, flags);
562 				list_move(&p->list, &priv->cm.rx_reap_list);
563 				spin_unlock_irqrestore(&priv->lock, flags);
564 				queue_work(ipoib_workqueue, &priv->cm.rx_reap_task);
565 			}
566 			return;
567 		}
568 	}
569 
570 	if (unlikely(!(wr_id & IPOIB_CM_RX_UPDATE_MASK))) {
571 		if (p && time_after_eq(jiffies, p->jiffies + IPOIB_CM_RX_UPDATE_TIME)) {
572 			spin_lock_irqsave(&priv->lock, flags);
573 			p->jiffies = jiffies;
574 			/* Move this entry to list head, but do not re-add it
575 			 * if it has been moved out of list. */
576 			if (p->state == IPOIB_CM_RX_LIVE)
577 				list_move(&p->list, &priv->cm.passive_ids);
578 			spin_unlock_irqrestore(&priv->lock, flags);
579 		}
580 	}
581 
582 	frags = PAGE_ALIGN(wc->byte_len - min(wc->byte_len,
583 					      (unsigned)IPOIB_CM_HEAD_SIZE)) / PAGE_SIZE;
584 
585 	newskb = ipoib_cm_alloc_rx_skb(dev, rx_ring, wr_id, frags, mapping);
586 	if (unlikely(!newskb)) {
587 		/*
588 		 * If we can't allocate a new RX buffer, dump
589 		 * this packet and reuse the old buffer.
590 		 */
591 		ipoib_dbg(priv, "failed to allocate receive buffer %d\n", wr_id);
592 		++dev->stats.rx_dropped;
593 		goto repost;
594 	}
595 
596 	ipoib_cm_dma_unmap_rx(priv, frags, rx_ring[wr_id].mapping);
597 	memcpy(rx_ring[wr_id].mapping, mapping, (frags + 1) * sizeof *mapping);
598 
599 	ipoib_dbg_data(priv, "received %d bytes, SLID 0x%04x\n",
600 		       wc->byte_len, wc->slid);
601 
602 	skb_put_frags(skb, IPOIB_CM_HEAD_SIZE, wc->byte_len, newskb);
603 
604 	skb->protocol = ((struct ipoib_header *) skb->data)->proto;
605 	skb_reset_mac_header(skb);
606 	skb_pull(skb, IPOIB_ENCAP_LEN);
607 
608 	dev->last_rx = jiffies;
609 	++dev->stats.rx_packets;
610 	dev->stats.rx_bytes += skb->len;
611 
612 	skb->dev = dev;
613 	/* XXX get correct PACKET_ type here */
614 	skb->pkt_type = PACKET_HOST;
615 	netif_receive_skb(skb);
616 
617 repost:
618 	if (has_srq) {
619 		if (unlikely(ipoib_cm_post_receive_srq(dev, wr_id)))
620 			ipoib_warn(priv, "ipoib_cm_post_receive_srq failed "
621 				   "for buf %d\n", wr_id);
622 	} else {
623 		if (unlikely(ipoib_cm_post_receive_nonsrq(dev, p, wr_id))) {
624 			--p->recv_count;
625 			ipoib_warn(priv, "ipoib_cm_post_receive_nonsrq failed "
626 				   "for buf %d\n", wr_id);
627 		}
628 	}
629 }
630 
631 static inline int post_send(struct ipoib_dev_priv *priv,
632 			    struct ipoib_cm_tx *tx,
633 			    unsigned int wr_id,
634 			    u64 addr, int len)
635 {
636 	struct ib_send_wr *bad_wr;
637 
638 	priv->tx_sge[0].addr          = addr;
639 	priv->tx_sge[0].length        = len;
640 
641 	priv->tx_wr.num_sge	= 1;
642 	priv->tx_wr.wr_id	= wr_id | IPOIB_OP_CM;
643 
644 	return ib_post_send(tx->qp, &priv->tx_wr, &bad_wr);
645 }
646 
647 void ipoib_cm_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_cm_tx *tx)
648 {
649 	struct ipoib_dev_priv *priv = netdev_priv(dev);
650 	struct ipoib_tx_buf *tx_req;
651 	u64 addr;
652 
653 	if (unlikely(skb->len > tx->mtu)) {
654 		ipoib_warn(priv, "packet len %d (> %d) too long to send, dropping\n",
655 			   skb->len, tx->mtu);
656 		++dev->stats.tx_dropped;
657 		++dev->stats.tx_errors;
658 		ipoib_cm_skb_too_long(dev, skb, tx->mtu - IPOIB_ENCAP_LEN);
659 		return;
660 	}
661 
662 	ipoib_dbg_data(priv, "sending packet: head 0x%x length %d connection 0x%x\n",
663 		       tx->tx_head, skb->len, tx->qp->qp_num);
664 
665 	/*
666 	 * We put the skb into the tx_ring _before_ we call post_send()
667 	 * because it's entirely possible that the completion handler will
668 	 * run before we execute anything after the post_send().  That
669 	 * means we have to make sure everything is properly recorded and
670 	 * our state is consistent before we call post_send().
671 	 */
672 	tx_req = &tx->tx_ring[tx->tx_head & (ipoib_sendq_size - 1)];
673 	tx_req->skb = skb;
674 	addr = ib_dma_map_single(priv->ca, skb->data, skb->len, DMA_TO_DEVICE);
675 	if (unlikely(ib_dma_mapping_error(priv->ca, addr))) {
676 		++dev->stats.tx_errors;
677 		dev_kfree_skb_any(skb);
678 		return;
679 	}
680 
681 	tx_req->mapping[0] = addr;
682 
683 	if (unlikely(post_send(priv, tx, tx->tx_head & (ipoib_sendq_size - 1),
684 			       addr, skb->len))) {
685 		ipoib_warn(priv, "post_send failed\n");
686 		++dev->stats.tx_errors;
687 		ib_dma_unmap_single(priv->ca, addr, skb->len, DMA_TO_DEVICE);
688 		dev_kfree_skb_any(skb);
689 	} else {
690 		dev->trans_start = jiffies;
691 		++tx->tx_head;
692 
693 		if (++priv->tx_outstanding == ipoib_sendq_size) {
694 			ipoib_dbg(priv, "TX ring 0x%x full, stopping kernel net queue\n",
695 				  tx->qp->qp_num);
696 			netif_stop_queue(dev);
697 		}
698 	}
699 }
700 
701 void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ib_wc *wc)
702 {
703 	struct ipoib_dev_priv *priv = netdev_priv(dev);
704 	struct ipoib_cm_tx *tx = wc->qp->qp_context;
705 	unsigned int wr_id = wc->wr_id & ~IPOIB_OP_CM;
706 	struct ipoib_tx_buf *tx_req;
707 	unsigned long flags;
708 
709 	ipoib_dbg_data(priv, "cm send completion: id %d, status: %d\n",
710 		       wr_id, wc->status);
711 
712 	if (unlikely(wr_id >= ipoib_sendq_size)) {
713 		ipoib_warn(priv, "cm send completion event with wrid %d (> %d)\n",
714 			   wr_id, ipoib_sendq_size);
715 		return;
716 	}
717 
718 	tx_req = &tx->tx_ring[wr_id];
719 
720 	ib_dma_unmap_single(priv->ca, tx_req->mapping[0], tx_req->skb->len, DMA_TO_DEVICE);
721 
722 	/* FIXME: is this right? Shouldn't we only increment on success? */
723 	++dev->stats.tx_packets;
724 	dev->stats.tx_bytes += tx_req->skb->len;
725 
726 	dev_kfree_skb_any(tx_req->skb);
727 
728 	spin_lock_irqsave(&priv->tx_lock, flags);
729 	++tx->tx_tail;
730 	if (unlikely(--priv->tx_outstanding == ipoib_sendq_size >> 1) &&
731 	    netif_queue_stopped(dev) &&
732 	    test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
733 		netif_wake_queue(dev);
734 
735 	if (wc->status != IB_WC_SUCCESS &&
736 	    wc->status != IB_WC_WR_FLUSH_ERR) {
737 		struct ipoib_neigh *neigh;
738 
739 		ipoib_dbg(priv, "failed cm send event "
740 			   "(status=%d, wrid=%d vend_err %x)\n",
741 			   wc->status, wr_id, wc->vendor_err);
742 
743 		spin_lock(&priv->lock);
744 		neigh = tx->neigh;
745 
746 		if (neigh) {
747 			neigh->cm = NULL;
748 			list_del(&neigh->list);
749 			if (neigh->ah)
750 				ipoib_put_ah(neigh->ah);
751 			ipoib_neigh_free(dev, neigh);
752 
753 			tx->neigh = NULL;
754 		}
755 
756 		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
757 			list_move(&tx->list, &priv->cm.reap_list);
758 			queue_work(ipoib_workqueue, &priv->cm.reap_task);
759 		}
760 
761 		clear_bit(IPOIB_FLAG_OPER_UP, &tx->flags);
762 
763 		spin_unlock(&priv->lock);
764 	}
765 
766 	spin_unlock_irqrestore(&priv->tx_lock, flags);
767 }
768 
769 int ipoib_cm_dev_open(struct net_device *dev)
770 {
771 	struct ipoib_dev_priv *priv = netdev_priv(dev);
772 	int ret;
773 
774 	if (!IPOIB_CM_SUPPORTED(dev->dev_addr))
775 		return 0;
776 
777 	priv->cm.id = ib_create_cm_id(priv->ca, ipoib_cm_rx_handler, dev);
778 	if (IS_ERR(priv->cm.id)) {
779 		printk(KERN_WARNING "%s: failed to create CM ID\n", priv->ca->name);
780 		ret = PTR_ERR(priv->cm.id);
781 		goto err_cm;
782 	}
783 
784 	ret = ib_cm_listen(priv->cm.id, cpu_to_be64(IPOIB_CM_IETF_ID | priv->qp->qp_num),
785 			   0, NULL);
786 	if (ret) {
787 		printk(KERN_WARNING "%s: failed to listen on ID 0x%llx\n", priv->ca->name,
788 		       IPOIB_CM_IETF_ID | priv->qp->qp_num);
789 		goto err_listen;
790 	}
791 
792 	return 0;
793 
794 err_listen:
795 	ib_destroy_cm_id(priv->cm.id);
796 err_cm:
797 	priv->cm.id = NULL;
798 	return ret;
799 }
800 
801 static void ipoib_cm_free_rx_reap_list(struct net_device *dev)
802 {
803 	struct ipoib_dev_priv *priv = netdev_priv(dev);
804 	struct ipoib_cm_rx *rx, *n;
805 	LIST_HEAD(list);
806 
807 	spin_lock_irq(&priv->lock);
808 	list_splice_init(&priv->cm.rx_reap_list, &list);
809 	spin_unlock_irq(&priv->lock);
810 
811 	list_for_each_entry_safe(rx, n, &list, list) {
812 		ib_destroy_cm_id(rx->id);
813 		ib_destroy_qp(rx->qp);
814 		if (!ipoib_cm_has_srq(dev)) {
815 			ipoib_cm_free_rx_ring(priv->dev, rx->rx_ring);
816 			spin_lock_irq(&priv->lock);
817 			--priv->cm.nonsrq_conn_qp;
818 			spin_unlock_irq(&priv->lock);
819 		}
820 		kfree(rx);
821 	}
822 }
823 
824 void ipoib_cm_dev_stop(struct net_device *dev)
825 {
826 	struct ipoib_dev_priv *priv = netdev_priv(dev);
827 	struct ipoib_cm_rx *p;
828 	unsigned long begin;
829 	int ret;
830 
831 	if (!IPOIB_CM_SUPPORTED(dev->dev_addr) || !priv->cm.id)
832 		return;
833 
834 	ib_destroy_cm_id(priv->cm.id);
835 	priv->cm.id = NULL;
836 
837 	spin_lock_irq(&priv->lock);
838 	while (!list_empty(&priv->cm.passive_ids)) {
839 		p = list_entry(priv->cm.passive_ids.next, typeof(*p), list);
840 		list_move(&p->list, &priv->cm.rx_error_list);
841 		p->state = IPOIB_CM_RX_ERROR;
842 		spin_unlock_irq(&priv->lock);
843 		ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
844 		if (ret)
845 			ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
846 		spin_lock_irq(&priv->lock);
847 	}
848 
849 	/* Wait for all RX to be drained */
850 	begin = jiffies;
851 
852 	while (!list_empty(&priv->cm.rx_error_list) ||
853 	       !list_empty(&priv->cm.rx_flush_list) ||
854 	       !list_empty(&priv->cm.rx_drain_list)) {
855 		if (time_after(jiffies, begin + 5 * HZ)) {
856 			ipoib_warn(priv, "RX drain timing out\n");
857 
858 			/*
859 			 * assume the HW is wedged and just free up everything.
860 			 */
861 			list_splice_init(&priv->cm.rx_flush_list,
862 					 &priv->cm.rx_reap_list);
863 			list_splice_init(&priv->cm.rx_error_list,
864 					 &priv->cm.rx_reap_list);
865 			list_splice_init(&priv->cm.rx_drain_list,
866 					 &priv->cm.rx_reap_list);
867 			break;
868 		}
869 		spin_unlock_irq(&priv->lock);
870 		msleep(1);
871 		ipoib_drain_cq(dev);
872 		spin_lock_irq(&priv->lock);
873 	}
874 
875 	spin_unlock_irq(&priv->lock);
876 
877 	ipoib_cm_free_rx_reap_list(dev);
878 
879 	cancel_delayed_work(&priv->cm.stale_task);
880 }
881 
882 static int ipoib_cm_rep_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
883 {
884 	struct ipoib_cm_tx *p = cm_id->context;
885 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
886 	struct ipoib_cm_data *data = event->private_data;
887 	struct sk_buff_head skqueue;
888 	struct ib_qp_attr qp_attr;
889 	int qp_attr_mask, ret;
890 	struct sk_buff *skb;
891 
892 	p->mtu = be32_to_cpu(data->mtu);
893 
894 	if (p->mtu <= IPOIB_ENCAP_LEN) {
895 		ipoib_warn(priv, "Rejecting connection: mtu %d <= %d\n",
896 			   p->mtu, IPOIB_ENCAP_LEN);
897 		return -EINVAL;
898 	}
899 
900 	qp_attr.qp_state = IB_QPS_RTR;
901 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
902 	if (ret) {
903 		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
904 		return ret;
905 	}
906 
907 	qp_attr.rq_psn = 0 /* FIXME */;
908 	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
909 	if (ret) {
910 		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
911 		return ret;
912 	}
913 
914 	qp_attr.qp_state = IB_QPS_RTS;
915 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
916 	if (ret) {
917 		ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret);
918 		return ret;
919 	}
920 	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
921 	if (ret) {
922 		ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret);
923 		return ret;
924 	}
925 
926 	skb_queue_head_init(&skqueue);
927 
928 	spin_lock_irq(&priv->lock);
929 	set_bit(IPOIB_FLAG_OPER_UP, &p->flags);
930 	if (p->neigh)
931 		while ((skb = __skb_dequeue(&p->neigh->queue)))
932 			__skb_queue_tail(&skqueue, skb);
933 	spin_unlock_irq(&priv->lock);
934 
935 	while ((skb = __skb_dequeue(&skqueue))) {
936 		skb->dev = p->dev;
937 		if (dev_queue_xmit(skb))
938 			ipoib_warn(priv, "dev_queue_xmit failed "
939 				   "to requeue packet\n");
940 	}
941 
942 	ret = ib_send_cm_rtu(cm_id, NULL, 0);
943 	if (ret) {
944 		ipoib_warn(priv, "failed to send RTU: %d\n", ret);
945 		return ret;
946 	}
947 	return 0;
948 }
949 
950 static struct ib_qp *ipoib_cm_create_tx_qp(struct net_device *dev, struct ipoib_cm_tx *tx)
951 {
952 	struct ipoib_dev_priv *priv = netdev_priv(dev);
953 	struct ib_qp_init_attr attr = {
954 		.send_cq		= priv->cq,
955 		.recv_cq		= priv->cq,
956 		.srq			= priv->cm.srq,
957 		.cap.max_send_wr	= ipoib_sendq_size,
958 		.cap.max_send_sge	= 1,
959 		.sq_sig_type		= IB_SIGNAL_ALL_WR,
960 		.qp_type		= IB_QPT_RC,
961 		.qp_context		= tx
962 	};
963 
964 	return ib_create_qp(priv->pd, &attr);
965 }
966 
967 static int ipoib_cm_send_req(struct net_device *dev,
968 			     struct ib_cm_id *id, struct ib_qp *qp,
969 			     u32 qpn,
970 			     struct ib_sa_path_rec *pathrec)
971 {
972 	struct ipoib_dev_priv *priv = netdev_priv(dev);
973 	struct ipoib_cm_data data = {};
974 	struct ib_cm_req_param req = {};
975 
976 	data.qpn = cpu_to_be32(priv->qp->qp_num);
977 	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
978 
979 	req.primary_path		= pathrec;
980 	req.alternate_path		= NULL;
981 	req.service_id			= cpu_to_be64(IPOIB_CM_IETF_ID | qpn);
982 	req.qp_num			= qp->qp_num;
983 	req.qp_type			= qp->qp_type;
984 	req.private_data		= &data;
985 	req.private_data_len		= sizeof data;
986 	req.flow_control		= 0;
987 
988 	req.starting_psn		= 0; /* FIXME */
989 
990 	/*
991 	 * Pick some arbitrary defaults here; we could make these
992 	 * module parameters if anyone cared about setting them.
993 	 */
994 	req.responder_resources		= 4;
995 	req.remote_cm_response_timeout	= 20;
996 	req.local_cm_response_timeout	= 20;
997 	req.retry_count			= 0; /* RFC draft warns against retries */
998 	req.rnr_retry_count		= 0; /* RFC draft warns against retries */
999 	req.max_cm_retries		= 15;
1000 	req.srq				= ipoib_cm_has_srq(dev);
1001 	return ib_send_cm_req(id, &req);
1002 }
1003 
1004 static int ipoib_cm_modify_tx_init(struct net_device *dev,
1005 				  struct ib_cm_id *cm_id, struct ib_qp *qp)
1006 {
1007 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1008 	struct ib_qp_attr qp_attr;
1009 	int qp_attr_mask, ret;
1010 	ret = ib_find_cached_pkey(priv->ca, priv->port, priv->pkey, &qp_attr.pkey_index);
1011 	if (ret) {
1012 		ipoib_warn(priv, "pkey 0x%x not in cache: %d\n", priv->pkey, ret);
1013 		return ret;
1014 	}
1015 
1016 	qp_attr.qp_state = IB_QPS_INIT;
1017 	qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE;
1018 	qp_attr.port_num = priv->port;
1019 	qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PKEY_INDEX | IB_QP_PORT;
1020 
1021 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
1022 	if (ret) {
1023 		ipoib_warn(priv, "failed to modify tx QP to INIT: %d\n", ret);
1024 		return ret;
1025 	}
1026 	return 0;
1027 }
1028 
1029 static int ipoib_cm_tx_init(struct ipoib_cm_tx *p, u32 qpn,
1030 			    struct ib_sa_path_rec *pathrec)
1031 {
1032 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
1033 	int ret;
1034 
1035 	p->tx_ring = vmalloc(ipoib_sendq_size * sizeof *p->tx_ring);
1036 	if (!p->tx_ring) {
1037 		ipoib_warn(priv, "failed to allocate tx ring\n");
1038 		ret = -ENOMEM;
1039 		goto err_tx;
1040 	}
1041 	memset(p->tx_ring, 0, ipoib_sendq_size * sizeof *p->tx_ring);
1042 
1043 	p->qp = ipoib_cm_create_tx_qp(p->dev, p);
1044 	if (IS_ERR(p->qp)) {
1045 		ret = PTR_ERR(p->qp);
1046 		ipoib_warn(priv, "failed to allocate tx qp: %d\n", ret);
1047 		goto err_qp;
1048 	}
1049 
1050 	p->id = ib_create_cm_id(priv->ca, ipoib_cm_tx_handler, p);
1051 	if (IS_ERR(p->id)) {
1052 		ret = PTR_ERR(p->id);
1053 		ipoib_warn(priv, "failed to create tx cm id: %d\n", ret);
1054 		goto err_id;
1055 	}
1056 
1057 	ret = ipoib_cm_modify_tx_init(p->dev, p->id,  p->qp);
1058 	if (ret) {
1059 		ipoib_warn(priv, "failed to modify tx qp to rtr: %d\n", ret);
1060 		goto err_modify;
1061 	}
1062 
1063 	ret = ipoib_cm_send_req(p->dev, p->id, p->qp, qpn, pathrec);
1064 	if (ret) {
1065 		ipoib_warn(priv, "failed to send cm req: %d\n", ret);
1066 		goto err_send_cm;
1067 	}
1068 
1069 	ipoib_dbg(priv, "Request connection 0x%x for gid " IPOIB_GID_FMT " qpn 0x%x\n",
1070 		  p->qp->qp_num, IPOIB_GID_ARG(pathrec->dgid), qpn);
1071 
1072 	return 0;
1073 
1074 err_send_cm:
1075 err_modify:
1076 	ib_destroy_cm_id(p->id);
1077 err_id:
1078 	p->id = NULL;
1079 	ib_destroy_qp(p->qp);
1080 err_qp:
1081 	p->qp = NULL;
1082 	vfree(p->tx_ring);
1083 err_tx:
1084 	return ret;
1085 }
1086 
1087 static void ipoib_cm_tx_destroy(struct ipoib_cm_tx *p)
1088 {
1089 	struct ipoib_dev_priv *priv = netdev_priv(p->dev);
1090 	struct ipoib_tx_buf *tx_req;
1091 	unsigned long flags;
1092 	unsigned long begin;
1093 
1094 	ipoib_dbg(priv, "Destroy active connection 0x%x head 0x%x tail 0x%x\n",
1095 		  p->qp ? p->qp->qp_num : 0, p->tx_head, p->tx_tail);
1096 
1097 	if (p->id)
1098 		ib_destroy_cm_id(p->id);
1099 
1100 	if (p->tx_ring) {
1101 		/* Wait for all sends to complete */
1102 		begin = jiffies;
1103 		while ((int) p->tx_tail - (int) p->tx_head < 0) {
1104 			if (time_after(jiffies, begin + 5 * HZ)) {
1105 				ipoib_warn(priv, "timing out; %d sends not completed\n",
1106 					   p->tx_head - p->tx_tail);
1107 				goto timeout;
1108 			}
1109 
1110 			msleep(1);
1111 		}
1112 	}
1113 
1114 timeout:
1115 
1116 	while ((int) p->tx_tail - (int) p->tx_head < 0) {
1117 		tx_req = &p->tx_ring[p->tx_tail & (ipoib_sendq_size - 1)];
1118 		ib_dma_unmap_single(priv->ca, tx_req->mapping[0], tx_req->skb->len,
1119 				    DMA_TO_DEVICE);
1120 		dev_kfree_skb_any(tx_req->skb);
1121 		++p->tx_tail;
1122 		spin_lock_irqsave(&priv->tx_lock, flags);
1123 		if (unlikely(--priv->tx_outstanding == ipoib_sendq_size >> 1) &&
1124 		    netif_queue_stopped(p->dev) &&
1125 		    test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
1126 			netif_wake_queue(p->dev);
1127 		spin_unlock_irqrestore(&priv->tx_lock, flags);
1128 	}
1129 
1130 	if (p->qp)
1131 		ib_destroy_qp(p->qp);
1132 
1133 	vfree(p->tx_ring);
1134 	kfree(p);
1135 }
1136 
1137 static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
1138 			       struct ib_cm_event *event)
1139 {
1140 	struct ipoib_cm_tx *tx = cm_id->context;
1141 	struct ipoib_dev_priv *priv = netdev_priv(tx->dev);
1142 	struct net_device *dev = priv->dev;
1143 	struct ipoib_neigh *neigh;
1144 	int ret;
1145 
1146 	switch (event->event) {
1147 	case IB_CM_DREQ_RECEIVED:
1148 		ipoib_dbg(priv, "DREQ received.\n");
1149 		ib_send_cm_drep(cm_id, NULL, 0);
1150 		break;
1151 	case IB_CM_REP_RECEIVED:
1152 		ipoib_dbg(priv, "REP received.\n");
1153 		ret = ipoib_cm_rep_handler(cm_id, event);
1154 		if (ret)
1155 			ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,
1156 				       NULL, 0, NULL, 0);
1157 		break;
1158 	case IB_CM_REQ_ERROR:
1159 	case IB_CM_REJ_RECEIVED:
1160 	case IB_CM_TIMEWAIT_EXIT:
1161 		ipoib_dbg(priv, "CM error %d.\n", event->event);
1162 		spin_lock_irq(&priv->tx_lock);
1163 		spin_lock(&priv->lock);
1164 		neigh = tx->neigh;
1165 
1166 		if (neigh) {
1167 			neigh->cm = NULL;
1168 			list_del(&neigh->list);
1169 			if (neigh->ah)
1170 				ipoib_put_ah(neigh->ah);
1171 			ipoib_neigh_free(dev, neigh);
1172 
1173 			tx->neigh = NULL;
1174 		}
1175 
1176 		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
1177 			list_move(&tx->list, &priv->cm.reap_list);
1178 			queue_work(ipoib_workqueue, &priv->cm.reap_task);
1179 		}
1180 
1181 		spin_unlock(&priv->lock);
1182 		spin_unlock_irq(&priv->tx_lock);
1183 		break;
1184 	default:
1185 		break;
1186 	}
1187 
1188 	return 0;
1189 }
1190 
1191 struct ipoib_cm_tx *ipoib_cm_create_tx(struct net_device *dev, struct ipoib_path *path,
1192 				       struct ipoib_neigh *neigh)
1193 {
1194 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1195 	struct ipoib_cm_tx *tx;
1196 
1197 	tx = kzalloc(sizeof *tx, GFP_ATOMIC);
1198 	if (!tx)
1199 		return NULL;
1200 
1201 	neigh->cm = tx;
1202 	tx->neigh = neigh;
1203 	tx->path = path;
1204 	tx->dev = dev;
1205 	list_add(&tx->list, &priv->cm.start_list);
1206 	set_bit(IPOIB_FLAG_INITIALIZED, &tx->flags);
1207 	queue_work(ipoib_workqueue, &priv->cm.start_task);
1208 	return tx;
1209 }
1210 
1211 void ipoib_cm_destroy_tx(struct ipoib_cm_tx *tx)
1212 {
1213 	struct ipoib_dev_priv *priv = netdev_priv(tx->dev);
1214 	if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
1215 		list_move(&tx->list, &priv->cm.reap_list);
1216 		queue_work(ipoib_workqueue, &priv->cm.reap_task);
1217 		ipoib_dbg(priv, "Reap connection for gid " IPOIB_GID_FMT "\n",
1218 			  IPOIB_GID_ARG(tx->neigh->dgid));
1219 		tx->neigh = NULL;
1220 	}
1221 }
1222 
1223 static void ipoib_cm_tx_start(struct work_struct *work)
1224 {
1225 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1226 						   cm.start_task);
1227 	struct net_device *dev = priv->dev;
1228 	struct ipoib_neigh *neigh;
1229 	struct ipoib_cm_tx *p;
1230 	unsigned long flags;
1231 	int ret;
1232 
1233 	struct ib_sa_path_rec pathrec;
1234 	u32 qpn;
1235 
1236 	spin_lock_irqsave(&priv->tx_lock, flags);
1237 	spin_lock(&priv->lock);
1238 	while (!list_empty(&priv->cm.start_list)) {
1239 		p = list_entry(priv->cm.start_list.next, typeof(*p), list);
1240 		list_del_init(&p->list);
1241 		neigh = p->neigh;
1242 		qpn = IPOIB_QPN(neigh->neighbour->ha);
1243 		memcpy(&pathrec, &p->path->pathrec, sizeof pathrec);
1244 		spin_unlock(&priv->lock);
1245 		spin_unlock_irqrestore(&priv->tx_lock, flags);
1246 		ret = ipoib_cm_tx_init(p, qpn, &pathrec);
1247 		spin_lock_irqsave(&priv->tx_lock, flags);
1248 		spin_lock(&priv->lock);
1249 		if (ret) {
1250 			neigh = p->neigh;
1251 			if (neigh) {
1252 				neigh->cm = NULL;
1253 				list_del(&neigh->list);
1254 				if (neigh->ah)
1255 					ipoib_put_ah(neigh->ah);
1256 				ipoib_neigh_free(dev, neigh);
1257 			}
1258 			list_del(&p->list);
1259 			kfree(p);
1260 		}
1261 	}
1262 	spin_unlock(&priv->lock);
1263 	spin_unlock_irqrestore(&priv->tx_lock, flags);
1264 }
1265 
1266 static void ipoib_cm_tx_reap(struct work_struct *work)
1267 {
1268 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1269 						   cm.reap_task);
1270 	struct ipoib_cm_tx *p;
1271 
1272 	spin_lock_irq(&priv->tx_lock);
1273 	spin_lock(&priv->lock);
1274 	while (!list_empty(&priv->cm.reap_list)) {
1275 		p = list_entry(priv->cm.reap_list.next, typeof(*p), list);
1276 		list_del(&p->list);
1277 		spin_unlock(&priv->lock);
1278 		spin_unlock_irq(&priv->tx_lock);
1279 		ipoib_cm_tx_destroy(p);
1280 		spin_lock_irq(&priv->tx_lock);
1281 		spin_lock(&priv->lock);
1282 	}
1283 	spin_unlock(&priv->lock);
1284 	spin_unlock_irq(&priv->tx_lock);
1285 }
1286 
1287 static void ipoib_cm_skb_reap(struct work_struct *work)
1288 {
1289 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1290 						   cm.skb_task);
1291 	struct sk_buff *skb;
1292 
1293 	unsigned mtu = priv->mcast_mtu;
1294 
1295 	spin_lock_irq(&priv->tx_lock);
1296 	spin_lock(&priv->lock);
1297 	while ((skb = skb_dequeue(&priv->cm.skb_queue))) {
1298 		spin_unlock(&priv->lock);
1299 		spin_unlock_irq(&priv->tx_lock);
1300 		if (skb->protocol == htons(ETH_P_IP))
1301 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
1302 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1303 		else if (skb->protocol == htons(ETH_P_IPV6))
1304 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, priv->dev);
1305 #endif
1306 		dev_kfree_skb_any(skb);
1307 		spin_lock_irq(&priv->tx_lock);
1308 		spin_lock(&priv->lock);
1309 	}
1310 	spin_unlock(&priv->lock);
1311 	spin_unlock_irq(&priv->tx_lock);
1312 }
1313 
1314 void ipoib_cm_skb_too_long(struct net_device *dev, struct sk_buff *skb,
1315 			   unsigned int mtu)
1316 {
1317 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1318 	int e = skb_queue_empty(&priv->cm.skb_queue);
1319 
1320 	if (skb->dst)
1321 		skb->dst->ops->update_pmtu(skb->dst, mtu);
1322 
1323 	skb_queue_tail(&priv->cm.skb_queue, skb);
1324 	if (e)
1325 		queue_work(ipoib_workqueue, &priv->cm.skb_task);
1326 }
1327 
1328 static void ipoib_cm_rx_reap(struct work_struct *work)
1329 {
1330 	ipoib_cm_free_rx_reap_list(container_of(work, struct ipoib_dev_priv,
1331 						cm.rx_reap_task)->dev);
1332 }
1333 
1334 static void ipoib_cm_stale_task(struct work_struct *work)
1335 {
1336 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1337 						   cm.stale_task.work);
1338 	struct ipoib_cm_rx *p;
1339 	int ret;
1340 
1341 	spin_lock_irq(&priv->lock);
1342 	while (!list_empty(&priv->cm.passive_ids)) {
1343 		/* List is sorted by LRU, start from tail,
1344 		 * stop when we see a recently used entry */
1345 		p = list_entry(priv->cm.passive_ids.prev, typeof(*p), list);
1346 		if (time_before_eq(jiffies, p->jiffies + IPOIB_CM_RX_TIMEOUT))
1347 			break;
1348 		list_move(&p->list, &priv->cm.rx_error_list);
1349 		p->state = IPOIB_CM_RX_ERROR;
1350 		spin_unlock_irq(&priv->lock);
1351 		ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
1352 		if (ret)
1353 			ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
1354 		spin_lock_irq(&priv->lock);
1355 	}
1356 
1357 	if (!list_empty(&priv->cm.passive_ids))
1358 		queue_delayed_work(ipoib_workqueue,
1359 				   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
1360 	spin_unlock_irq(&priv->lock);
1361 }
1362 
1363 
1364 static ssize_t show_mode(struct device *d, struct device_attribute *attr,
1365 			 char *buf)
1366 {
1367 	struct ipoib_dev_priv *priv = netdev_priv(to_net_dev(d));
1368 
1369 	if (test_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags))
1370 		return sprintf(buf, "connected\n");
1371 	else
1372 		return sprintf(buf, "datagram\n");
1373 }
1374 
1375 static ssize_t set_mode(struct device *d, struct device_attribute *attr,
1376 			const char *buf, size_t count)
1377 {
1378 	struct net_device *dev = to_net_dev(d);
1379 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1380 
1381 	/* flush paths if we switch modes so that connections are restarted */
1382 	if (IPOIB_CM_SUPPORTED(dev->dev_addr) && !strcmp(buf, "connected\n")) {
1383 		set_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags);
1384 		ipoib_warn(priv, "enabling connected mode "
1385 			   "will cause multicast packet drops\n");
1386 		ipoib_flush_paths(dev);
1387 		return count;
1388 	}
1389 
1390 	if (!strcmp(buf, "datagram\n")) {
1391 		clear_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags);
1392 		dev->mtu = min(priv->mcast_mtu, dev->mtu);
1393 		ipoib_flush_paths(dev);
1394 		return count;
1395 	}
1396 
1397 	return -EINVAL;
1398 }
1399 
1400 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, show_mode, set_mode);
1401 
1402 int ipoib_cm_add_mode_attr(struct net_device *dev)
1403 {
1404 	return device_create_file(&dev->dev, &dev_attr_mode);
1405 }
1406 
1407 static void ipoib_cm_create_srq(struct net_device *dev, int max_sge)
1408 {
1409 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1410 	struct ib_srq_init_attr srq_init_attr = {
1411 		.attr = {
1412 			.max_wr  = ipoib_recvq_size,
1413 			.max_sge = max_sge
1414 		}
1415 	};
1416 
1417 	priv->cm.srq = ib_create_srq(priv->pd, &srq_init_attr);
1418 	if (IS_ERR(priv->cm.srq)) {
1419 		if (PTR_ERR(priv->cm.srq) != -ENOSYS)
1420 			printk(KERN_WARNING "%s: failed to allocate SRQ, error %ld\n",
1421 			       priv->ca->name, PTR_ERR(priv->cm.srq));
1422 		priv->cm.srq = NULL;
1423 		return;
1424 	}
1425 
1426 	priv->cm.srq_ring = kzalloc(ipoib_recvq_size * sizeof *priv->cm.srq_ring,
1427 				    GFP_KERNEL);
1428 	if (!priv->cm.srq_ring) {
1429 		printk(KERN_WARNING "%s: failed to allocate CM SRQ ring (%d entries)\n",
1430 		       priv->ca->name, ipoib_recvq_size);
1431 		ib_destroy_srq(priv->cm.srq);
1432 		priv->cm.srq = NULL;
1433 	}
1434 }
1435 
1436 int ipoib_cm_dev_init(struct net_device *dev)
1437 {
1438 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1439 	int i, ret;
1440 	struct ib_device_attr attr;
1441 
1442 	INIT_LIST_HEAD(&priv->cm.passive_ids);
1443 	INIT_LIST_HEAD(&priv->cm.reap_list);
1444 	INIT_LIST_HEAD(&priv->cm.start_list);
1445 	INIT_LIST_HEAD(&priv->cm.rx_error_list);
1446 	INIT_LIST_HEAD(&priv->cm.rx_flush_list);
1447 	INIT_LIST_HEAD(&priv->cm.rx_drain_list);
1448 	INIT_LIST_HEAD(&priv->cm.rx_reap_list);
1449 	INIT_WORK(&priv->cm.start_task, ipoib_cm_tx_start);
1450 	INIT_WORK(&priv->cm.reap_task, ipoib_cm_tx_reap);
1451 	INIT_WORK(&priv->cm.skb_task, ipoib_cm_skb_reap);
1452 	INIT_WORK(&priv->cm.rx_reap_task, ipoib_cm_rx_reap);
1453 	INIT_DELAYED_WORK(&priv->cm.stale_task, ipoib_cm_stale_task);
1454 
1455 	skb_queue_head_init(&priv->cm.skb_queue);
1456 
1457 	ret = ib_query_device(priv->ca, &attr);
1458 	if (ret) {
1459 		printk(KERN_WARNING "ib_query_device() failed with %d\n", ret);
1460 		return ret;
1461 	}
1462 
1463 	ipoib_dbg(priv, "max_srq_sge=%d\n", attr.max_srq_sge);
1464 
1465 	attr.max_srq_sge = min_t(int, IPOIB_CM_RX_SG, attr.max_srq_sge);
1466 	ipoib_cm_create_srq(dev, attr.max_srq_sge);
1467 	if (ipoib_cm_has_srq(dev)) {
1468 		priv->cm.max_cm_mtu = attr.max_srq_sge * PAGE_SIZE - 0x10;
1469 		priv->cm.num_frags  = attr.max_srq_sge;
1470 		ipoib_dbg(priv, "max_cm_mtu = 0x%x, num_frags=%d\n",
1471 			  priv->cm.max_cm_mtu, priv->cm.num_frags);
1472 	} else {
1473 		priv->cm.max_cm_mtu = IPOIB_CM_MTU;
1474 		priv->cm.num_frags  = IPOIB_CM_RX_SG;
1475 	}
1476 
1477 	for (i = 0; i < priv->cm.num_frags; ++i)
1478 		priv->cm.rx_sge[i].lkey	= priv->mr->lkey;
1479 
1480 	priv->cm.rx_sge[0].length = IPOIB_CM_HEAD_SIZE;
1481 	for (i = 1; i < priv->cm.num_frags; ++i)
1482 		priv->cm.rx_sge[i].length = PAGE_SIZE;
1483 	priv->cm.rx_wr.next = NULL;
1484 	priv->cm.rx_wr.sg_list = priv->cm.rx_sge;
1485 	priv->cm.rx_wr.num_sge = priv->cm.num_frags;
1486 
1487 	if (ipoib_cm_has_srq(dev)) {
1488 		for (i = 0; i < ipoib_recvq_size; ++i) {
1489 			if (!ipoib_cm_alloc_rx_skb(dev, priv->cm.srq_ring, i,
1490 						   priv->cm.num_frags - 1,
1491 						   priv->cm.srq_ring[i].mapping)) {
1492 				ipoib_warn(priv, "failed to allocate "
1493 					   "receive buffer %d\n", i);
1494 				ipoib_cm_dev_cleanup(dev);
1495 				return -ENOMEM;
1496 			}
1497 
1498 			if (ipoib_cm_post_receive_srq(dev, i)) {
1499 				ipoib_warn(priv, "ipoib_cm_post_receive_srq "
1500 					   "failed for buf %d\n", i);
1501 				ipoib_cm_dev_cleanup(dev);
1502 				return -EIO;
1503 			}
1504 		}
1505 	}
1506 
1507 	priv->dev->dev_addr[0] = IPOIB_FLAGS_RC;
1508 	return 0;
1509 }
1510 
1511 void ipoib_cm_dev_cleanup(struct net_device *dev)
1512 {
1513 	struct ipoib_dev_priv *priv = netdev_priv(dev);
1514 	int ret;
1515 
1516 	if (!priv->cm.srq)
1517 		return;
1518 
1519 	ipoib_dbg(priv, "Cleanup ipoib connected mode.\n");
1520 
1521 	ret = ib_destroy_srq(priv->cm.srq);
1522 	if (ret)
1523 		ipoib_warn(priv, "ib_destroy_srq failed: %d\n", ret);
1524 
1525 	priv->cm.srq = NULL;
1526 	if (!priv->cm.srq_ring)
1527 		return;
1528 
1529 	ipoib_cm_free_rx_ring(dev, priv->cm.srq_ring);
1530 	priv->cm.srq_ring = NULL;
1531 }
1532