1 /*
2  * Copyright (c) 2006 Mellanox Technologies. All rights reserved
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #include <rdma/ib_cm.h>
34 #include <net/dst.h>
35 #include <net/icmp.h>
36 #include <linux/icmpv6.h>
37 #include <linux/delay.h>
38 #include <linux/slab.h>
39 #include <linux/vmalloc.h>
40 #include <linux/moduleparam.h>
41 #include <linux/sched/signal.h>
42 #include <linux/sched/mm.h>
43 
44 #include "ipoib.h"
45 
46 int ipoib_max_conn_qp = 128;
47 
48 module_param_named(max_nonsrq_conn_qp, ipoib_max_conn_qp, int, 0444);
49 MODULE_PARM_DESC(max_nonsrq_conn_qp,
50 		 "Max number of connected-mode QPs per interface "
51 		 "(applied only if shared receive queue is not available)");
52 
53 #ifdef CONFIG_INFINIBAND_IPOIB_DEBUG_DATA
54 static int data_debug_level;
55 
56 module_param_named(cm_data_debug_level, data_debug_level, int, 0644);
57 MODULE_PARM_DESC(cm_data_debug_level,
58 		 "Enable data path debug tracing for connected mode if > 0");
59 #endif
60 
61 #define IPOIB_CM_IETF_ID 0x1000000000000000ULL
62 
63 #define IPOIB_CM_RX_UPDATE_TIME (256 * HZ)
64 #define IPOIB_CM_RX_TIMEOUT     (2 * 256 * HZ)
65 #define IPOIB_CM_RX_DELAY       (3 * 256 * HZ)
66 #define IPOIB_CM_RX_UPDATE_MASK (0x3)
67 
68 #define IPOIB_CM_RX_RESERVE     (ALIGN(IPOIB_HARD_LEN, 16) - IPOIB_ENCAP_LEN)
69 
70 static struct ib_qp_attr ipoib_cm_err_attr = {
71 	.qp_state = IB_QPS_ERR
72 };
73 
74 #define IPOIB_CM_RX_DRAIN_WRID 0xffffffff
75 
76 static struct ib_send_wr ipoib_cm_rx_drain_wr = {
77 	.opcode = IB_WR_SEND,
78 };
79 
80 static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
81 			       struct ib_cm_event *event);
82 
83 static void ipoib_cm_dma_unmap_rx(struct ipoib_dev_priv *priv, int frags,
84 				  u64 mapping[IPOIB_CM_RX_SG])
85 {
86 	int i;
87 
88 	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
89 
90 	for (i = 0; i < frags; ++i)
91 		ib_dma_unmap_page(priv->ca, mapping[i + 1], PAGE_SIZE, DMA_FROM_DEVICE);
92 }
93 
94 static int ipoib_cm_post_receive_srq(struct net_device *dev, int id)
95 {
96 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
97 	struct ib_recv_wr *bad_wr;
98 	int i, ret;
99 
100 	priv->cm.rx_wr.wr_id = id | IPOIB_OP_CM | IPOIB_OP_RECV;
101 
102 	for (i = 0; i < priv->cm.num_frags; ++i)
103 		priv->cm.rx_sge[i].addr = priv->cm.srq_ring[id].mapping[i];
104 
105 	ret = ib_post_srq_recv(priv->cm.srq, &priv->cm.rx_wr, &bad_wr);
106 	if (unlikely(ret)) {
107 		ipoib_warn(priv, "post srq failed for buf %d (%d)\n", id, ret);
108 		ipoib_cm_dma_unmap_rx(priv, priv->cm.num_frags - 1,
109 				      priv->cm.srq_ring[id].mapping);
110 		dev_kfree_skb_any(priv->cm.srq_ring[id].skb);
111 		priv->cm.srq_ring[id].skb = NULL;
112 	}
113 
114 	return ret;
115 }
116 
117 static int ipoib_cm_post_receive_nonsrq(struct net_device *dev,
118 					struct ipoib_cm_rx *rx,
119 					struct ib_recv_wr *wr,
120 					struct ib_sge *sge, int id)
121 {
122 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
123 	struct ib_recv_wr *bad_wr;
124 	int i, ret;
125 
126 	wr->wr_id = id | IPOIB_OP_CM | IPOIB_OP_RECV;
127 
128 	for (i = 0; i < IPOIB_CM_RX_SG; ++i)
129 		sge[i].addr = rx->rx_ring[id].mapping[i];
130 
131 	ret = ib_post_recv(rx->qp, wr, &bad_wr);
132 	if (unlikely(ret)) {
133 		ipoib_warn(priv, "post recv failed for buf %d (%d)\n", id, ret);
134 		ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
135 				      rx->rx_ring[id].mapping);
136 		dev_kfree_skb_any(rx->rx_ring[id].skb);
137 		rx->rx_ring[id].skb = NULL;
138 	}
139 
140 	return ret;
141 }
142 
143 static struct sk_buff *ipoib_cm_alloc_rx_skb(struct net_device *dev,
144 					     struct ipoib_cm_rx_buf *rx_ring,
145 					     int id, int frags,
146 					     u64 mapping[IPOIB_CM_RX_SG],
147 					     gfp_t gfp)
148 {
149 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
150 	struct sk_buff *skb;
151 	int i;
152 
153 	skb = dev_alloc_skb(ALIGN(IPOIB_CM_HEAD_SIZE + IPOIB_PSEUDO_LEN, 16));
154 	if (unlikely(!skb))
155 		return NULL;
156 
157 	/*
158 	 * IPoIB adds a IPOIB_ENCAP_LEN byte header, this will align the
159 	 * IP header to a multiple of 16.
160 	 */
161 	skb_reserve(skb, IPOIB_CM_RX_RESERVE);
162 
163 	mapping[0] = ib_dma_map_single(priv->ca, skb->data, IPOIB_CM_HEAD_SIZE,
164 				       DMA_FROM_DEVICE);
165 	if (unlikely(ib_dma_mapping_error(priv->ca, mapping[0]))) {
166 		dev_kfree_skb_any(skb);
167 		return NULL;
168 	}
169 
170 	for (i = 0; i < frags; i++) {
171 		struct page *page = alloc_page(gfp);
172 
173 		if (!page)
174 			goto partial_error;
175 		skb_fill_page_desc(skb, i, page, 0, PAGE_SIZE);
176 
177 		mapping[i + 1] = ib_dma_map_page(priv->ca, page,
178 						 0, PAGE_SIZE, DMA_FROM_DEVICE);
179 		if (unlikely(ib_dma_mapping_error(priv->ca, mapping[i + 1])))
180 			goto partial_error;
181 	}
182 
183 	rx_ring[id].skb = skb;
184 	return skb;
185 
186 partial_error:
187 
188 	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
189 
190 	for (; i > 0; --i)
191 		ib_dma_unmap_page(priv->ca, mapping[i], PAGE_SIZE, DMA_FROM_DEVICE);
192 
193 	dev_kfree_skb_any(skb);
194 	return NULL;
195 }
196 
197 static void ipoib_cm_free_rx_ring(struct net_device *dev,
198 				  struct ipoib_cm_rx_buf *rx_ring)
199 {
200 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
201 	int i;
202 
203 	for (i = 0; i < ipoib_recvq_size; ++i)
204 		if (rx_ring[i].skb) {
205 			ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
206 					      rx_ring[i].mapping);
207 			dev_kfree_skb_any(rx_ring[i].skb);
208 		}
209 
210 	vfree(rx_ring);
211 }
212 
213 static void ipoib_cm_start_rx_drain(struct ipoib_dev_priv *priv)
214 {
215 	struct ib_send_wr *bad_wr;
216 	struct ipoib_cm_rx *p;
217 
218 	/* We only reserved 1 extra slot in CQ for drain WRs, so
219 	 * make sure we have at most 1 outstanding WR. */
220 	if (list_empty(&priv->cm.rx_flush_list) ||
221 	    !list_empty(&priv->cm.rx_drain_list))
222 		return;
223 
224 	/*
225 	 * QPs on flush list are error state.  This way, a "flush
226 	 * error" WC will be immediately generated for each WR we post.
227 	 */
228 	p = list_entry(priv->cm.rx_flush_list.next, typeof(*p), list);
229 	ipoib_cm_rx_drain_wr.wr_id = IPOIB_CM_RX_DRAIN_WRID;
230 	if (ib_post_send(p->qp, &ipoib_cm_rx_drain_wr, &bad_wr))
231 		ipoib_warn(priv, "failed to post drain wr\n");
232 
233 	list_splice_init(&priv->cm.rx_flush_list, &priv->cm.rx_drain_list);
234 }
235 
236 static void ipoib_cm_rx_event_handler(struct ib_event *event, void *ctx)
237 {
238 	struct ipoib_cm_rx *p = ctx;
239 	struct ipoib_dev_priv *priv = ipoib_priv(p->dev);
240 	unsigned long flags;
241 
242 	if (event->event != IB_EVENT_QP_LAST_WQE_REACHED)
243 		return;
244 
245 	spin_lock_irqsave(&priv->lock, flags);
246 	list_move(&p->list, &priv->cm.rx_flush_list);
247 	p->state = IPOIB_CM_RX_FLUSH;
248 	ipoib_cm_start_rx_drain(priv);
249 	spin_unlock_irqrestore(&priv->lock, flags);
250 }
251 
252 static struct ib_qp *ipoib_cm_create_rx_qp(struct net_device *dev,
253 					   struct ipoib_cm_rx *p)
254 {
255 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
256 	struct ib_qp_init_attr attr = {
257 		.event_handler = ipoib_cm_rx_event_handler,
258 		.send_cq = priv->recv_cq, /* For drain WR */
259 		.recv_cq = priv->recv_cq,
260 		.srq = priv->cm.srq,
261 		.cap.max_send_wr = 1, /* For drain WR */
262 		.cap.max_send_sge = 1, /* FIXME: 0 Seems not to work */
263 		.sq_sig_type = IB_SIGNAL_ALL_WR,
264 		.qp_type = IB_QPT_RC,
265 		.qp_context = p,
266 	};
267 
268 	if (!ipoib_cm_has_srq(dev)) {
269 		attr.cap.max_recv_wr  = ipoib_recvq_size;
270 		attr.cap.max_recv_sge = IPOIB_CM_RX_SG;
271 	}
272 
273 	return ib_create_qp(priv->pd, &attr);
274 }
275 
276 static int ipoib_cm_modify_rx_qp(struct net_device *dev,
277 				 struct ib_cm_id *cm_id, struct ib_qp *qp,
278 				 unsigned psn)
279 {
280 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
281 	struct ib_qp_attr qp_attr;
282 	int qp_attr_mask, ret;
283 
284 	qp_attr.qp_state = IB_QPS_INIT;
285 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
286 	if (ret) {
287 		ipoib_warn(priv, "failed to init QP attr for INIT: %d\n", ret);
288 		return ret;
289 	}
290 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
291 	if (ret) {
292 		ipoib_warn(priv, "failed to modify QP to INIT: %d\n", ret);
293 		return ret;
294 	}
295 	qp_attr.qp_state = IB_QPS_RTR;
296 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
297 	if (ret) {
298 		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
299 		return ret;
300 	}
301 	qp_attr.rq_psn = psn;
302 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
303 	if (ret) {
304 		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
305 		return ret;
306 	}
307 
308 	/*
309 	 * Current Mellanox HCA firmware won't generate completions
310 	 * with error for drain WRs unless the QP has been moved to
311 	 * RTS first. This work-around leaves a window where a QP has
312 	 * moved to error asynchronously, but this will eventually get
313 	 * fixed in firmware, so let's not error out if modify QP
314 	 * fails.
315 	 */
316 	qp_attr.qp_state = IB_QPS_RTS;
317 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
318 	if (ret) {
319 		ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret);
320 		return 0;
321 	}
322 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
323 	if (ret) {
324 		ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret);
325 		return 0;
326 	}
327 
328 	return 0;
329 }
330 
331 static void ipoib_cm_init_rx_wr(struct net_device *dev,
332 				struct ib_recv_wr *wr,
333 				struct ib_sge *sge)
334 {
335 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
336 	int i;
337 
338 	for (i = 0; i < priv->cm.num_frags; ++i)
339 		sge[i].lkey = priv->pd->local_dma_lkey;
340 
341 	sge[0].length = IPOIB_CM_HEAD_SIZE;
342 	for (i = 1; i < priv->cm.num_frags; ++i)
343 		sge[i].length = PAGE_SIZE;
344 
345 	wr->next    = NULL;
346 	wr->sg_list = sge;
347 	wr->num_sge = priv->cm.num_frags;
348 }
349 
350 static int ipoib_cm_nonsrq_init_rx(struct net_device *dev, struct ib_cm_id *cm_id,
351 				   struct ipoib_cm_rx *rx)
352 {
353 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
354 	struct {
355 		struct ib_recv_wr wr;
356 		struct ib_sge sge[IPOIB_CM_RX_SG];
357 	} *t;
358 	int ret;
359 	int i;
360 
361 	rx->rx_ring = vzalloc(ipoib_recvq_size * sizeof *rx->rx_ring);
362 	if (!rx->rx_ring)
363 		return -ENOMEM;
364 
365 	t = kmalloc(sizeof *t, GFP_KERNEL);
366 	if (!t) {
367 		ret = -ENOMEM;
368 		goto err_free_1;
369 	}
370 
371 	ipoib_cm_init_rx_wr(dev, &t->wr, t->sge);
372 
373 	spin_lock_irq(&priv->lock);
374 
375 	if (priv->cm.nonsrq_conn_qp >= ipoib_max_conn_qp) {
376 		spin_unlock_irq(&priv->lock);
377 		ib_send_cm_rej(cm_id, IB_CM_REJ_NO_QP, NULL, 0, NULL, 0);
378 		ret = -EINVAL;
379 		goto err_free;
380 	} else
381 		++priv->cm.nonsrq_conn_qp;
382 
383 	spin_unlock_irq(&priv->lock);
384 
385 	for (i = 0; i < ipoib_recvq_size; ++i) {
386 		if (!ipoib_cm_alloc_rx_skb(dev, rx->rx_ring, i, IPOIB_CM_RX_SG - 1,
387 					   rx->rx_ring[i].mapping,
388 					   GFP_KERNEL)) {
389 			ipoib_warn(priv, "failed to allocate receive buffer %d\n", i);
390 			ret = -ENOMEM;
391 			goto err_count;
392 		}
393 		ret = ipoib_cm_post_receive_nonsrq(dev, rx, &t->wr, t->sge, i);
394 		if (ret) {
395 			ipoib_warn(priv, "ipoib_cm_post_receive_nonsrq "
396 				   "failed for buf %d\n", i);
397 			ret = -EIO;
398 			goto err_count;
399 		}
400 	}
401 
402 	rx->recv_count = ipoib_recvq_size;
403 
404 	kfree(t);
405 
406 	return 0;
407 
408 err_count:
409 	spin_lock_irq(&priv->lock);
410 	--priv->cm.nonsrq_conn_qp;
411 	spin_unlock_irq(&priv->lock);
412 
413 err_free:
414 	kfree(t);
415 
416 err_free_1:
417 	ipoib_cm_free_rx_ring(dev, rx->rx_ring);
418 
419 	return ret;
420 }
421 
422 static int ipoib_cm_send_rep(struct net_device *dev, struct ib_cm_id *cm_id,
423 			     struct ib_qp *qp, struct ib_cm_req_event_param *req,
424 			     unsigned psn)
425 {
426 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
427 	struct ipoib_cm_data data = {};
428 	struct ib_cm_rep_param rep = {};
429 
430 	data.qpn = cpu_to_be32(priv->qp->qp_num);
431 	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
432 
433 	rep.private_data = &data;
434 	rep.private_data_len = sizeof data;
435 	rep.flow_control = 0;
436 	rep.rnr_retry_count = req->rnr_retry_count;
437 	rep.srq = ipoib_cm_has_srq(dev);
438 	rep.qp_num = qp->qp_num;
439 	rep.starting_psn = psn;
440 	return ib_send_cm_rep(cm_id, &rep);
441 }
442 
443 static int ipoib_cm_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
444 {
445 	struct net_device *dev = cm_id->context;
446 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
447 	struct ipoib_cm_rx *p;
448 	unsigned psn;
449 	int ret;
450 
451 	ipoib_dbg(priv, "REQ arrived\n");
452 	p = kzalloc(sizeof *p, GFP_KERNEL);
453 	if (!p)
454 		return -ENOMEM;
455 	p->dev = dev;
456 	p->id = cm_id;
457 	cm_id->context = p;
458 	p->state = IPOIB_CM_RX_LIVE;
459 	p->jiffies = jiffies;
460 	INIT_LIST_HEAD(&p->list);
461 
462 	p->qp = ipoib_cm_create_rx_qp(dev, p);
463 	if (IS_ERR(p->qp)) {
464 		ret = PTR_ERR(p->qp);
465 		goto err_qp;
466 	}
467 
468 	psn = prandom_u32() & 0xffffff;
469 	ret = ipoib_cm_modify_rx_qp(dev, cm_id, p->qp, psn);
470 	if (ret)
471 		goto err_modify;
472 
473 	if (!ipoib_cm_has_srq(dev)) {
474 		ret = ipoib_cm_nonsrq_init_rx(dev, cm_id, p);
475 		if (ret)
476 			goto err_modify;
477 	}
478 
479 	spin_lock_irq(&priv->lock);
480 	queue_delayed_work(priv->wq,
481 			   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
482 	/* Add this entry to passive ids list head, but do not re-add it
483 	 * if IB_EVENT_QP_LAST_WQE_REACHED has moved it to flush list. */
484 	p->jiffies = jiffies;
485 	if (p->state == IPOIB_CM_RX_LIVE)
486 		list_move(&p->list, &priv->cm.passive_ids);
487 	spin_unlock_irq(&priv->lock);
488 
489 	ret = ipoib_cm_send_rep(dev, cm_id, p->qp, &event->param.req_rcvd, psn);
490 	if (ret) {
491 		ipoib_warn(priv, "failed to send REP: %d\n", ret);
492 		if (ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE))
493 			ipoib_warn(priv, "unable to move qp to error state\n");
494 	}
495 	return 0;
496 
497 err_modify:
498 	ib_destroy_qp(p->qp);
499 err_qp:
500 	kfree(p);
501 	return ret;
502 }
503 
504 static int ipoib_cm_rx_handler(struct ib_cm_id *cm_id,
505 			       struct ib_cm_event *event)
506 {
507 	struct ipoib_cm_rx *p;
508 	struct ipoib_dev_priv *priv;
509 
510 	switch (event->event) {
511 	case IB_CM_REQ_RECEIVED:
512 		return ipoib_cm_req_handler(cm_id, event);
513 	case IB_CM_DREQ_RECEIVED:
514 		p = cm_id->context;
515 		ib_send_cm_drep(cm_id, NULL, 0);
516 		/* Fall through */
517 	case IB_CM_REJ_RECEIVED:
518 		p = cm_id->context;
519 		priv = ipoib_priv(p->dev);
520 		if (ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE))
521 			ipoib_warn(priv, "unable to move qp to error state\n");
522 		/* Fall through */
523 	default:
524 		return 0;
525 	}
526 }
527 /* Adjust length of skb with fragments to match received data */
528 static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space,
529 			  unsigned int length, struct sk_buff *toskb)
530 {
531 	int i, num_frags;
532 	unsigned int size;
533 
534 	/* put header into skb */
535 	size = min(length, hdr_space);
536 	skb->tail += size;
537 	skb->len += size;
538 	length -= size;
539 
540 	num_frags = skb_shinfo(skb)->nr_frags;
541 	for (i = 0; i < num_frags; i++) {
542 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
543 
544 		if (length == 0) {
545 			/* don't need this page */
546 			skb_fill_page_desc(toskb, i, skb_frag_page(frag),
547 					   0, PAGE_SIZE);
548 			--skb_shinfo(skb)->nr_frags;
549 		} else {
550 			size = min(length, (unsigned) PAGE_SIZE);
551 
552 			skb_frag_size_set(frag, size);
553 			skb->data_len += size;
554 			skb->truesize += size;
555 			skb->len += size;
556 			length -= size;
557 		}
558 	}
559 }
560 
561 void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
562 {
563 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
564 	struct ipoib_cm_rx_buf *rx_ring;
565 	unsigned int wr_id = wc->wr_id & ~(IPOIB_OP_CM | IPOIB_OP_RECV);
566 	struct sk_buff *skb, *newskb;
567 	struct ipoib_cm_rx *p;
568 	unsigned long flags;
569 	u64 mapping[IPOIB_CM_RX_SG];
570 	int frags;
571 	int has_srq;
572 	struct sk_buff *small_skb;
573 
574 	ipoib_dbg_data(priv, "cm recv completion: id %d, status: %d\n",
575 		       wr_id, wc->status);
576 
577 	if (unlikely(wr_id >= ipoib_recvq_size)) {
578 		if (wr_id == (IPOIB_CM_RX_DRAIN_WRID & ~(IPOIB_OP_CM | IPOIB_OP_RECV))) {
579 			spin_lock_irqsave(&priv->lock, flags);
580 			list_splice_init(&priv->cm.rx_drain_list, &priv->cm.rx_reap_list);
581 			ipoib_cm_start_rx_drain(priv);
582 			queue_work(priv->wq, &priv->cm.rx_reap_task);
583 			spin_unlock_irqrestore(&priv->lock, flags);
584 		} else
585 			ipoib_warn(priv, "cm recv completion event with wrid %d (> %d)\n",
586 				   wr_id, ipoib_recvq_size);
587 		return;
588 	}
589 
590 	p = wc->qp->qp_context;
591 
592 	has_srq = ipoib_cm_has_srq(dev);
593 	rx_ring = has_srq ? priv->cm.srq_ring : p->rx_ring;
594 
595 	skb = rx_ring[wr_id].skb;
596 
597 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
598 		ipoib_dbg(priv, "cm recv error "
599 			   "(status=%d, wrid=%d vend_err %x)\n",
600 			   wc->status, wr_id, wc->vendor_err);
601 		++dev->stats.rx_dropped;
602 		if (has_srq)
603 			goto repost;
604 		else {
605 			if (!--p->recv_count) {
606 				spin_lock_irqsave(&priv->lock, flags);
607 				list_move(&p->list, &priv->cm.rx_reap_list);
608 				spin_unlock_irqrestore(&priv->lock, flags);
609 				queue_work(priv->wq, &priv->cm.rx_reap_task);
610 			}
611 			return;
612 		}
613 	}
614 
615 	if (unlikely(!(wr_id & IPOIB_CM_RX_UPDATE_MASK))) {
616 		if (p && time_after_eq(jiffies, p->jiffies + IPOIB_CM_RX_UPDATE_TIME)) {
617 			spin_lock_irqsave(&priv->lock, flags);
618 			p->jiffies = jiffies;
619 			/* Move this entry to list head, but do not re-add it
620 			 * if it has been moved out of list. */
621 			if (p->state == IPOIB_CM_RX_LIVE)
622 				list_move(&p->list, &priv->cm.passive_ids);
623 			spin_unlock_irqrestore(&priv->lock, flags);
624 		}
625 	}
626 
627 	if (wc->byte_len < IPOIB_CM_COPYBREAK) {
628 		int dlen = wc->byte_len;
629 
630 		small_skb = dev_alloc_skb(dlen + IPOIB_CM_RX_RESERVE);
631 		if (small_skb) {
632 			skb_reserve(small_skb, IPOIB_CM_RX_RESERVE);
633 			ib_dma_sync_single_for_cpu(priv->ca, rx_ring[wr_id].mapping[0],
634 						   dlen, DMA_FROM_DEVICE);
635 			skb_copy_from_linear_data(skb, small_skb->data, dlen);
636 			ib_dma_sync_single_for_device(priv->ca, rx_ring[wr_id].mapping[0],
637 						      dlen, DMA_FROM_DEVICE);
638 			skb_put(small_skb, dlen);
639 			skb = small_skb;
640 			goto copied;
641 		}
642 	}
643 
644 	frags = PAGE_ALIGN(wc->byte_len - min(wc->byte_len,
645 					      (unsigned)IPOIB_CM_HEAD_SIZE)) / PAGE_SIZE;
646 
647 	newskb = ipoib_cm_alloc_rx_skb(dev, rx_ring, wr_id, frags,
648 				       mapping, GFP_ATOMIC);
649 	if (unlikely(!newskb)) {
650 		/*
651 		 * If we can't allocate a new RX buffer, dump
652 		 * this packet and reuse the old buffer.
653 		 */
654 		ipoib_dbg(priv, "failed to allocate receive buffer %d\n", wr_id);
655 		++dev->stats.rx_dropped;
656 		goto repost;
657 	}
658 
659 	ipoib_cm_dma_unmap_rx(priv, frags, rx_ring[wr_id].mapping);
660 	memcpy(rx_ring[wr_id].mapping, mapping, (frags + 1) * sizeof *mapping);
661 
662 	ipoib_dbg_data(priv, "received %d bytes, SLID 0x%04x\n",
663 		       wc->byte_len, wc->slid);
664 
665 	skb_put_frags(skb, IPOIB_CM_HEAD_SIZE, wc->byte_len, newskb);
666 
667 copied:
668 	skb->protocol = ((struct ipoib_header *) skb->data)->proto;
669 	skb_add_pseudo_hdr(skb);
670 
671 	++dev->stats.rx_packets;
672 	dev->stats.rx_bytes += skb->len;
673 
674 	skb->dev = dev;
675 	/* XXX get correct PACKET_ type here */
676 	skb->pkt_type = PACKET_HOST;
677 	netif_receive_skb(skb);
678 
679 repost:
680 	if (has_srq) {
681 		if (unlikely(ipoib_cm_post_receive_srq(dev, wr_id)))
682 			ipoib_warn(priv, "ipoib_cm_post_receive_srq failed "
683 				   "for buf %d\n", wr_id);
684 	} else {
685 		if (unlikely(ipoib_cm_post_receive_nonsrq(dev, p,
686 							  &priv->cm.rx_wr,
687 							  priv->cm.rx_sge,
688 							  wr_id))) {
689 			--p->recv_count;
690 			ipoib_warn(priv, "ipoib_cm_post_receive_nonsrq failed "
691 				   "for buf %d\n", wr_id);
692 		}
693 	}
694 }
695 
696 static inline int post_send(struct ipoib_dev_priv *priv,
697 			    struct ipoib_cm_tx *tx,
698 			    unsigned int wr_id,
699 			    struct ipoib_tx_buf *tx_req)
700 {
701 	struct ib_send_wr *bad_wr;
702 
703 	ipoib_build_sge(priv, tx_req);
704 
705 	priv->tx_wr.wr.wr_id	= wr_id | IPOIB_OP_CM;
706 
707 	return ib_post_send(tx->qp, &priv->tx_wr.wr, &bad_wr);
708 }
709 
710 void ipoib_cm_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_cm_tx *tx)
711 {
712 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
713 	struct ipoib_tx_buf *tx_req;
714 	int rc;
715 	unsigned usable_sge = tx->max_send_sge - !!skb_headlen(skb);
716 
717 	if (unlikely(skb->len > tx->mtu)) {
718 		ipoib_warn(priv, "packet len %d (> %d) too long to send, dropping\n",
719 			   skb->len, tx->mtu);
720 		++dev->stats.tx_dropped;
721 		++dev->stats.tx_errors;
722 		ipoib_cm_skb_too_long(dev, skb, tx->mtu - IPOIB_ENCAP_LEN);
723 		return;
724 	}
725 	if (skb_shinfo(skb)->nr_frags > usable_sge) {
726 		if (skb_linearize(skb) < 0) {
727 			ipoib_warn(priv, "skb could not be linearized\n");
728 			++dev->stats.tx_dropped;
729 			++dev->stats.tx_errors;
730 			dev_kfree_skb_any(skb);
731 			return;
732 		}
733 		/* Does skb_linearize return ok without reducing nr_frags? */
734 		if (skb_shinfo(skb)->nr_frags > usable_sge) {
735 			ipoib_warn(priv, "too many frags after skb linearize\n");
736 			++dev->stats.tx_dropped;
737 			++dev->stats.tx_errors;
738 			dev_kfree_skb_any(skb);
739 			return;
740 		}
741 	}
742 	ipoib_dbg_data(priv, "sending packet: head 0x%x length %d connection 0x%x\n",
743 		       tx->tx_head, skb->len, tx->qp->qp_num);
744 
745 	/*
746 	 * We put the skb into the tx_ring _before_ we call post_send()
747 	 * because it's entirely possible that the completion handler will
748 	 * run before we execute anything after the post_send().  That
749 	 * means we have to make sure everything is properly recorded and
750 	 * our state is consistent before we call post_send().
751 	 */
752 	tx_req = &tx->tx_ring[tx->tx_head & (ipoib_sendq_size - 1)];
753 	tx_req->skb = skb;
754 
755 	if (unlikely(ipoib_dma_map_tx(priv->ca, tx_req))) {
756 		++dev->stats.tx_errors;
757 		dev_kfree_skb_any(skb);
758 		return;
759 	}
760 
761 	skb_orphan(skb);
762 	skb_dst_drop(skb);
763 
764 	rc = post_send(priv, tx, tx->tx_head & (ipoib_sendq_size - 1), tx_req);
765 	if (unlikely(rc)) {
766 		ipoib_warn(priv, "post_send failed, error %d\n", rc);
767 		++dev->stats.tx_errors;
768 		ipoib_dma_unmap_tx(priv, tx_req);
769 		dev_kfree_skb_any(skb);
770 	} else {
771 		netif_trans_update(dev);
772 		++tx->tx_head;
773 
774 		if (++priv->tx_outstanding == ipoib_sendq_size) {
775 			ipoib_dbg(priv, "TX ring 0x%x full, stopping kernel net queue\n",
776 				  tx->qp->qp_num);
777 			netif_stop_queue(dev);
778 			rc = ib_req_notify_cq(priv->send_cq,
779 				IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
780 			if (rc < 0)
781 				ipoib_warn(priv, "request notify on send CQ failed\n");
782 			else if (rc)
783 				ipoib_send_comp_handler(priv->send_cq, dev);
784 		}
785 	}
786 }
787 
788 void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ib_wc *wc)
789 {
790 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
791 	struct ipoib_cm_tx *tx = wc->qp->qp_context;
792 	unsigned int wr_id = wc->wr_id & ~IPOIB_OP_CM;
793 	struct ipoib_tx_buf *tx_req;
794 	unsigned long flags;
795 
796 	ipoib_dbg_data(priv, "cm send completion: id %d, status: %d\n",
797 		       wr_id, wc->status);
798 
799 	if (unlikely(wr_id >= ipoib_sendq_size)) {
800 		ipoib_warn(priv, "cm send completion event with wrid %d (> %d)\n",
801 			   wr_id, ipoib_sendq_size);
802 		return;
803 	}
804 
805 	tx_req = &tx->tx_ring[wr_id];
806 
807 	ipoib_dma_unmap_tx(priv, tx_req);
808 
809 	/* FIXME: is this right? Shouldn't we only increment on success? */
810 	++dev->stats.tx_packets;
811 	dev->stats.tx_bytes += tx_req->skb->len;
812 
813 	dev_kfree_skb_any(tx_req->skb);
814 
815 	netif_tx_lock(dev);
816 
817 	++tx->tx_tail;
818 	if (unlikely(--priv->tx_outstanding == ipoib_sendq_size >> 1) &&
819 	    netif_queue_stopped(dev) &&
820 	    test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
821 		netif_wake_queue(dev);
822 
823 	if (wc->status != IB_WC_SUCCESS &&
824 	    wc->status != IB_WC_WR_FLUSH_ERR) {
825 		struct ipoib_neigh *neigh;
826 
827 		if (wc->status != IB_WC_RNR_RETRY_EXC_ERR)
828 			ipoib_warn(priv, "failed cm send event (status=%d, wrid=%d vend_err %x)\n",
829 				   wc->status, wr_id, wc->vendor_err);
830 		else
831 			ipoib_dbg(priv, "failed cm send event (status=%d, wrid=%d vend_err %x)\n",
832 				  wc->status, wr_id, wc->vendor_err);
833 
834 		spin_lock_irqsave(&priv->lock, flags);
835 		neigh = tx->neigh;
836 
837 		if (neigh) {
838 			neigh->cm = NULL;
839 			ipoib_neigh_free(neigh);
840 
841 			tx->neigh = NULL;
842 		}
843 
844 		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
845 			list_move(&tx->list, &priv->cm.reap_list);
846 			queue_work(priv->wq, &priv->cm.reap_task);
847 		}
848 
849 		clear_bit(IPOIB_FLAG_OPER_UP, &tx->flags);
850 
851 		spin_unlock_irqrestore(&priv->lock, flags);
852 	}
853 
854 	netif_tx_unlock(dev);
855 }
856 
857 int ipoib_cm_dev_open(struct net_device *dev)
858 {
859 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
860 	int ret;
861 
862 	if (!IPOIB_CM_SUPPORTED(dev->dev_addr))
863 		return 0;
864 
865 	priv->cm.id = ib_create_cm_id(priv->ca, ipoib_cm_rx_handler, dev);
866 	if (IS_ERR(priv->cm.id)) {
867 		printk(KERN_WARNING "%s: failed to create CM ID\n", priv->ca->name);
868 		ret = PTR_ERR(priv->cm.id);
869 		goto err_cm;
870 	}
871 
872 	ret = ib_cm_listen(priv->cm.id, cpu_to_be64(IPOIB_CM_IETF_ID | priv->qp->qp_num),
873 			   0);
874 	if (ret) {
875 		printk(KERN_WARNING "%s: failed to listen on ID 0x%llx\n", priv->ca->name,
876 		       IPOIB_CM_IETF_ID | priv->qp->qp_num);
877 		goto err_listen;
878 	}
879 
880 	return 0;
881 
882 err_listen:
883 	ib_destroy_cm_id(priv->cm.id);
884 err_cm:
885 	priv->cm.id = NULL;
886 	return ret;
887 }
888 
889 static void ipoib_cm_free_rx_reap_list(struct net_device *dev)
890 {
891 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
892 	struct ipoib_cm_rx *rx, *n;
893 	LIST_HEAD(list);
894 
895 	spin_lock_irq(&priv->lock);
896 	list_splice_init(&priv->cm.rx_reap_list, &list);
897 	spin_unlock_irq(&priv->lock);
898 
899 	list_for_each_entry_safe(rx, n, &list, list) {
900 		ib_destroy_cm_id(rx->id);
901 		ib_destroy_qp(rx->qp);
902 		if (!ipoib_cm_has_srq(dev)) {
903 			ipoib_cm_free_rx_ring(priv->dev, rx->rx_ring);
904 			spin_lock_irq(&priv->lock);
905 			--priv->cm.nonsrq_conn_qp;
906 			spin_unlock_irq(&priv->lock);
907 		}
908 		kfree(rx);
909 	}
910 }
911 
912 void ipoib_cm_dev_stop(struct net_device *dev)
913 {
914 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
915 	struct ipoib_cm_rx *p;
916 	unsigned long begin;
917 	int ret;
918 
919 	if (!IPOIB_CM_SUPPORTED(dev->dev_addr) || !priv->cm.id)
920 		return;
921 
922 	ib_destroy_cm_id(priv->cm.id);
923 	priv->cm.id = NULL;
924 
925 	spin_lock_irq(&priv->lock);
926 	while (!list_empty(&priv->cm.passive_ids)) {
927 		p = list_entry(priv->cm.passive_ids.next, typeof(*p), list);
928 		list_move(&p->list, &priv->cm.rx_error_list);
929 		p->state = IPOIB_CM_RX_ERROR;
930 		spin_unlock_irq(&priv->lock);
931 		ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
932 		if (ret)
933 			ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
934 		spin_lock_irq(&priv->lock);
935 	}
936 
937 	/* Wait for all RX to be drained */
938 	begin = jiffies;
939 
940 	while (!list_empty(&priv->cm.rx_error_list) ||
941 	       !list_empty(&priv->cm.rx_flush_list) ||
942 	       !list_empty(&priv->cm.rx_drain_list)) {
943 		if (time_after(jiffies, begin + 5 * HZ)) {
944 			ipoib_warn(priv, "RX drain timing out\n");
945 
946 			/*
947 			 * assume the HW is wedged and just free up everything.
948 			 */
949 			list_splice_init(&priv->cm.rx_flush_list,
950 					 &priv->cm.rx_reap_list);
951 			list_splice_init(&priv->cm.rx_error_list,
952 					 &priv->cm.rx_reap_list);
953 			list_splice_init(&priv->cm.rx_drain_list,
954 					 &priv->cm.rx_reap_list);
955 			break;
956 		}
957 		spin_unlock_irq(&priv->lock);
958 		usleep_range(1000, 2000);
959 		ipoib_drain_cq(dev);
960 		spin_lock_irq(&priv->lock);
961 	}
962 
963 	spin_unlock_irq(&priv->lock);
964 
965 	ipoib_cm_free_rx_reap_list(dev);
966 
967 	cancel_delayed_work(&priv->cm.stale_task);
968 }
969 
970 static int ipoib_cm_rep_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
971 {
972 	struct ipoib_cm_tx *p = cm_id->context;
973 	struct ipoib_dev_priv *priv = ipoib_priv(p->dev);
974 	struct ipoib_cm_data *data = event->private_data;
975 	struct sk_buff_head skqueue;
976 	struct ib_qp_attr qp_attr;
977 	int qp_attr_mask, ret;
978 	struct sk_buff *skb;
979 
980 	p->mtu = be32_to_cpu(data->mtu);
981 
982 	if (p->mtu <= IPOIB_ENCAP_LEN) {
983 		ipoib_warn(priv, "Rejecting connection: mtu %d <= %d\n",
984 			   p->mtu, IPOIB_ENCAP_LEN);
985 		return -EINVAL;
986 	}
987 
988 	qp_attr.qp_state = IB_QPS_RTR;
989 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
990 	if (ret) {
991 		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
992 		return ret;
993 	}
994 
995 	qp_attr.rq_psn = 0 /* FIXME */;
996 	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
997 	if (ret) {
998 		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
999 		return ret;
1000 	}
1001 
1002 	qp_attr.qp_state = IB_QPS_RTS;
1003 	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
1004 	if (ret) {
1005 		ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret);
1006 		return ret;
1007 	}
1008 	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
1009 	if (ret) {
1010 		ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret);
1011 		return ret;
1012 	}
1013 
1014 	skb_queue_head_init(&skqueue);
1015 
1016 	spin_lock_irq(&priv->lock);
1017 	set_bit(IPOIB_FLAG_OPER_UP, &p->flags);
1018 	if (p->neigh)
1019 		while ((skb = __skb_dequeue(&p->neigh->queue)))
1020 			__skb_queue_tail(&skqueue, skb);
1021 	spin_unlock_irq(&priv->lock);
1022 
1023 	while ((skb = __skb_dequeue(&skqueue))) {
1024 		skb->dev = p->dev;
1025 		ret = dev_queue_xmit(skb);
1026 		if (ret)
1027 			ipoib_warn(priv, "%s:dev_queue_xmit failed to re-queue packet, ret:%d\n",
1028 				   __func__, ret);
1029 	}
1030 
1031 	ret = ib_send_cm_rtu(cm_id, NULL, 0);
1032 	if (ret) {
1033 		ipoib_warn(priv, "failed to send RTU: %d\n", ret);
1034 		return ret;
1035 	}
1036 	return 0;
1037 }
1038 
1039 static struct ib_qp *ipoib_cm_create_tx_qp(struct net_device *dev, struct ipoib_cm_tx *tx)
1040 {
1041 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
1042 	struct ib_qp_init_attr attr = {
1043 		.send_cq		= priv->recv_cq,
1044 		.recv_cq		= priv->recv_cq,
1045 		.srq			= priv->cm.srq,
1046 		.cap.max_send_wr	= ipoib_sendq_size,
1047 		.cap.max_send_sge	= 1,
1048 		.sq_sig_type		= IB_SIGNAL_ALL_WR,
1049 		.qp_type		= IB_QPT_RC,
1050 		.qp_context		= tx,
1051 		.create_flags		= 0
1052 	};
1053 	struct ib_qp *tx_qp;
1054 
1055 	if (dev->features & NETIF_F_SG)
1056 		attr.cap.max_send_sge =
1057 			min_t(u32, priv->ca->attrs.max_sge, MAX_SKB_FRAGS + 1);
1058 
1059 	tx_qp = ib_create_qp(priv->pd, &attr);
1060 	tx->max_send_sge = attr.cap.max_send_sge;
1061 	return tx_qp;
1062 }
1063 
1064 static int ipoib_cm_send_req(struct net_device *dev,
1065 			     struct ib_cm_id *id, struct ib_qp *qp,
1066 			     u32 qpn,
1067 			     struct sa_path_rec *pathrec)
1068 {
1069 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
1070 	struct ipoib_cm_data data = {};
1071 	struct ib_cm_req_param req = {};
1072 
1073 	data.qpn = cpu_to_be32(priv->qp->qp_num);
1074 	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
1075 
1076 	req.primary_path		= pathrec;
1077 	req.alternate_path		= NULL;
1078 	req.service_id			= cpu_to_be64(IPOIB_CM_IETF_ID | qpn);
1079 	req.qp_num			= qp->qp_num;
1080 	req.qp_type			= qp->qp_type;
1081 	req.private_data		= &data;
1082 	req.private_data_len		= sizeof data;
1083 	req.flow_control		= 0;
1084 
1085 	req.starting_psn		= 0; /* FIXME */
1086 
1087 	/*
1088 	 * Pick some arbitrary defaults here; we could make these
1089 	 * module parameters if anyone cared about setting them.
1090 	 */
1091 	req.responder_resources		= 4;
1092 	req.remote_cm_response_timeout	= 20;
1093 	req.local_cm_response_timeout	= 20;
1094 	req.retry_count			= 0; /* RFC draft warns against retries */
1095 	req.rnr_retry_count		= 0; /* RFC draft warns against retries */
1096 	req.max_cm_retries		= 15;
1097 	req.srq				= ipoib_cm_has_srq(dev);
1098 	return ib_send_cm_req(id, &req);
1099 }
1100 
1101 static int ipoib_cm_modify_tx_init(struct net_device *dev,
1102 				  struct ib_cm_id *cm_id, struct ib_qp *qp)
1103 {
1104 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
1105 	struct ib_qp_attr qp_attr;
1106 	int qp_attr_mask, ret;
1107 	ret = ib_find_pkey(priv->ca, priv->port, priv->pkey, &qp_attr.pkey_index);
1108 	if (ret) {
1109 		ipoib_warn(priv, "pkey 0x%x not found: %d\n", priv->pkey, ret);
1110 		return ret;
1111 	}
1112 
1113 	qp_attr.qp_state = IB_QPS_INIT;
1114 	qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE;
1115 	qp_attr.port_num = priv->port;
1116 	qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PKEY_INDEX | IB_QP_PORT;
1117 
1118 	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
1119 	if (ret) {
1120 		ipoib_warn(priv, "failed to modify tx QP to INIT: %d\n", ret);
1121 		return ret;
1122 	}
1123 	return 0;
1124 }
1125 
1126 static int ipoib_cm_tx_init(struct ipoib_cm_tx *p, u32 qpn,
1127 			    struct sa_path_rec *pathrec)
1128 {
1129 	struct ipoib_dev_priv *priv = ipoib_priv(p->dev);
1130 	unsigned int noio_flag;
1131 	int ret;
1132 
1133 	noio_flag = memalloc_noio_save();
1134 	p->tx_ring = vzalloc(ipoib_sendq_size * sizeof(*p->tx_ring));
1135 	if (!p->tx_ring) {
1136 		ret = -ENOMEM;
1137 		goto err_tx;
1138 	}
1139 	memset(p->tx_ring, 0, ipoib_sendq_size * sizeof *p->tx_ring);
1140 
1141 	p->qp = ipoib_cm_create_tx_qp(p->dev, p);
1142 	memalloc_noio_restore(noio_flag);
1143 	if (IS_ERR(p->qp)) {
1144 		ret = PTR_ERR(p->qp);
1145 		ipoib_warn(priv, "failed to create tx qp: %d\n", ret);
1146 		goto err_qp;
1147 	}
1148 
1149 	p->id = ib_create_cm_id(priv->ca, ipoib_cm_tx_handler, p);
1150 	if (IS_ERR(p->id)) {
1151 		ret = PTR_ERR(p->id);
1152 		ipoib_warn(priv, "failed to create tx cm id: %d\n", ret);
1153 		goto err_id;
1154 	}
1155 
1156 	ret = ipoib_cm_modify_tx_init(p->dev, p->id,  p->qp);
1157 	if (ret) {
1158 		ipoib_warn(priv, "failed to modify tx qp to rtr: %d\n", ret);
1159 		goto err_modify_send;
1160 	}
1161 
1162 	ret = ipoib_cm_send_req(p->dev, p->id, p->qp, qpn, pathrec);
1163 	if (ret) {
1164 		ipoib_warn(priv, "failed to send cm req: %d\n", ret);
1165 		goto err_modify_send;
1166 	}
1167 
1168 	ipoib_dbg(priv, "Request connection 0x%x for gid %pI6 qpn 0x%x\n",
1169 		  p->qp->qp_num, pathrec->dgid.raw, qpn);
1170 
1171 	return 0;
1172 
1173 err_modify_send:
1174 	ib_destroy_cm_id(p->id);
1175 err_id:
1176 	p->id = NULL;
1177 	ib_destroy_qp(p->qp);
1178 err_qp:
1179 	p->qp = NULL;
1180 	vfree(p->tx_ring);
1181 err_tx:
1182 	return ret;
1183 }
1184 
1185 static void ipoib_cm_tx_destroy(struct ipoib_cm_tx *p)
1186 {
1187 	struct ipoib_dev_priv *priv = ipoib_priv(p->dev);
1188 	struct ipoib_tx_buf *tx_req;
1189 	unsigned long begin;
1190 
1191 	ipoib_dbg(priv, "Destroy active connection 0x%x head 0x%x tail 0x%x\n",
1192 		  p->qp ? p->qp->qp_num : 0, p->tx_head, p->tx_tail);
1193 
1194 	if (p->id)
1195 		ib_destroy_cm_id(p->id);
1196 
1197 	if (p->tx_ring) {
1198 		/* Wait for all sends to complete */
1199 		begin = jiffies;
1200 		while ((int) p->tx_tail - (int) p->tx_head < 0) {
1201 			if (time_after(jiffies, begin + 5 * HZ)) {
1202 				ipoib_warn(priv, "timing out; %d sends not completed\n",
1203 					   p->tx_head - p->tx_tail);
1204 				goto timeout;
1205 			}
1206 
1207 			usleep_range(1000, 2000);
1208 		}
1209 	}
1210 
1211 timeout:
1212 
1213 	while ((int) p->tx_tail - (int) p->tx_head < 0) {
1214 		tx_req = &p->tx_ring[p->tx_tail & (ipoib_sendq_size - 1)];
1215 		ipoib_dma_unmap_tx(priv, tx_req);
1216 		dev_kfree_skb_any(tx_req->skb);
1217 		++p->tx_tail;
1218 		netif_tx_lock_bh(p->dev);
1219 		if (unlikely(--priv->tx_outstanding == ipoib_sendq_size >> 1) &&
1220 		    netif_queue_stopped(p->dev) &&
1221 		    test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
1222 			netif_wake_queue(p->dev);
1223 		netif_tx_unlock_bh(p->dev);
1224 	}
1225 
1226 	if (p->qp)
1227 		ib_destroy_qp(p->qp);
1228 
1229 	vfree(p->tx_ring);
1230 	kfree(p);
1231 }
1232 
1233 static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
1234 			       struct ib_cm_event *event)
1235 {
1236 	struct ipoib_cm_tx *tx = cm_id->context;
1237 	struct ipoib_dev_priv *priv = ipoib_priv(tx->dev);
1238 	struct net_device *dev = priv->dev;
1239 	struct ipoib_neigh *neigh;
1240 	unsigned long flags;
1241 	int ret;
1242 
1243 	switch (event->event) {
1244 	case IB_CM_DREQ_RECEIVED:
1245 		ipoib_dbg(priv, "DREQ received.\n");
1246 		ib_send_cm_drep(cm_id, NULL, 0);
1247 		break;
1248 	case IB_CM_REP_RECEIVED:
1249 		ipoib_dbg(priv, "REP received.\n");
1250 		ret = ipoib_cm_rep_handler(cm_id, event);
1251 		if (ret)
1252 			ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,
1253 				       NULL, 0, NULL, 0);
1254 		break;
1255 	case IB_CM_REQ_ERROR:
1256 	case IB_CM_REJ_RECEIVED:
1257 	case IB_CM_TIMEWAIT_EXIT:
1258 		ipoib_dbg(priv, "CM error %d.\n", event->event);
1259 		netif_tx_lock_bh(dev);
1260 		spin_lock_irqsave(&priv->lock, flags);
1261 		neigh = tx->neigh;
1262 
1263 		if (neigh) {
1264 			neigh->cm = NULL;
1265 			ipoib_neigh_free(neigh);
1266 
1267 			tx->neigh = NULL;
1268 		}
1269 
1270 		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
1271 			list_move(&tx->list, &priv->cm.reap_list);
1272 			queue_work(priv->wq, &priv->cm.reap_task);
1273 		}
1274 
1275 		spin_unlock_irqrestore(&priv->lock, flags);
1276 		netif_tx_unlock_bh(dev);
1277 		break;
1278 	default:
1279 		break;
1280 	}
1281 
1282 	return 0;
1283 }
1284 
1285 struct ipoib_cm_tx *ipoib_cm_create_tx(struct net_device *dev, struct ipoib_path *path,
1286 				       struct ipoib_neigh *neigh)
1287 {
1288 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
1289 	struct ipoib_cm_tx *tx;
1290 
1291 	tx = kzalloc(sizeof *tx, GFP_ATOMIC);
1292 	if (!tx)
1293 		return NULL;
1294 
1295 	neigh->cm = tx;
1296 	tx->neigh = neigh;
1297 	tx->path = path;
1298 	tx->dev = dev;
1299 	list_add(&tx->list, &priv->cm.start_list);
1300 	set_bit(IPOIB_FLAG_INITIALIZED, &tx->flags);
1301 	queue_work(priv->wq, &priv->cm.start_task);
1302 	return tx;
1303 }
1304 
1305 void ipoib_cm_destroy_tx(struct ipoib_cm_tx *tx)
1306 {
1307 	struct ipoib_dev_priv *priv = ipoib_priv(tx->dev);
1308 	unsigned long flags;
1309 	if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
1310 		spin_lock_irqsave(&priv->lock, flags);
1311 		list_move(&tx->list, &priv->cm.reap_list);
1312 		queue_work(priv->wq, &priv->cm.reap_task);
1313 		ipoib_dbg(priv, "Reap connection for gid %pI6\n",
1314 			  tx->neigh->daddr + 4);
1315 		tx->neigh = NULL;
1316 		spin_unlock_irqrestore(&priv->lock, flags);
1317 	}
1318 }
1319 
1320 #define QPN_AND_OPTIONS_OFFSET	4
1321 
1322 static void ipoib_cm_tx_start(struct work_struct *work)
1323 {
1324 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1325 						   cm.start_task);
1326 	struct net_device *dev = priv->dev;
1327 	struct ipoib_neigh *neigh;
1328 	struct ipoib_cm_tx *p;
1329 	unsigned long flags;
1330 	struct ipoib_path *path;
1331 	int ret;
1332 
1333 	struct sa_path_rec pathrec;
1334 	u32 qpn;
1335 
1336 	netif_tx_lock_bh(dev);
1337 	spin_lock_irqsave(&priv->lock, flags);
1338 
1339 	while (!list_empty(&priv->cm.start_list)) {
1340 		p = list_entry(priv->cm.start_list.next, typeof(*p), list);
1341 		list_del_init(&p->list);
1342 		neigh = p->neigh;
1343 
1344 		qpn = IPOIB_QPN(neigh->daddr);
1345 		/*
1346 		 * As long as the search is with these 2 locks,
1347 		 * path existence indicates its validity.
1348 		 */
1349 		path = __path_find(dev, neigh->daddr + QPN_AND_OPTIONS_OFFSET);
1350 		if (!path) {
1351 			pr_info("%s ignore not valid path %pI6\n",
1352 				__func__,
1353 				neigh->daddr + QPN_AND_OPTIONS_OFFSET);
1354 			goto free_neigh;
1355 		}
1356 		memcpy(&pathrec, &p->path->pathrec, sizeof pathrec);
1357 
1358 		spin_unlock_irqrestore(&priv->lock, flags);
1359 		netif_tx_unlock_bh(dev);
1360 
1361 		ret = ipoib_cm_tx_init(p, qpn, &pathrec);
1362 
1363 		netif_tx_lock_bh(dev);
1364 		spin_lock_irqsave(&priv->lock, flags);
1365 
1366 		if (ret) {
1367 free_neigh:
1368 			neigh = p->neigh;
1369 			if (neigh) {
1370 				neigh->cm = NULL;
1371 				ipoib_neigh_free(neigh);
1372 			}
1373 			list_del(&p->list);
1374 			kfree(p);
1375 		}
1376 	}
1377 
1378 	spin_unlock_irqrestore(&priv->lock, flags);
1379 	netif_tx_unlock_bh(dev);
1380 }
1381 
1382 static void ipoib_cm_tx_reap(struct work_struct *work)
1383 {
1384 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1385 						   cm.reap_task);
1386 	struct net_device *dev = priv->dev;
1387 	struct ipoib_cm_tx *p;
1388 	unsigned long flags;
1389 
1390 	netif_tx_lock_bh(dev);
1391 	spin_lock_irqsave(&priv->lock, flags);
1392 
1393 	while (!list_empty(&priv->cm.reap_list)) {
1394 		p = list_entry(priv->cm.reap_list.next, typeof(*p), list);
1395 		list_del_init(&p->list);
1396 		spin_unlock_irqrestore(&priv->lock, flags);
1397 		netif_tx_unlock_bh(dev);
1398 		ipoib_cm_tx_destroy(p);
1399 		netif_tx_lock_bh(dev);
1400 		spin_lock_irqsave(&priv->lock, flags);
1401 	}
1402 
1403 	spin_unlock_irqrestore(&priv->lock, flags);
1404 	netif_tx_unlock_bh(dev);
1405 }
1406 
1407 static void ipoib_cm_skb_reap(struct work_struct *work)
1408 {
1409 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1410 						   cm.skb_task);
1411 	struct net_device *dev = priv->dev;
1412 	struct sk_buff *skb;
1413 	unsigned long flags;
1414 	unsigned mtu = priv->mcast_mtu;
1415 
1416 	netif_tx_lock_bh(dev);
1417 	spin_lock_irqsave(&priv->lock, flags);
1418 
1419 	while ((skb = skb_dequeue(&priv->cm.skb_queue))) {
1420 		spin_unlock_irqrestore(&priv->lock, flags);
1421 		netif_tx_unlock_bh(dev);
1422 
1423 		if (skb->protocol == htons(ETH_P_IP))
1424 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
1425 #if IS_ENABLED(CONFIG_IPV6)
1426 		else if (skb->protocol == htons(ETH_P_IPV6))
1427 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1428 #endif
1429 		dev_kfree_skb_any(skb);
1430 
1431 		netif_tx_lock_bh(dev);
1432 		spin_lock_irqsave(&priv->lock, flags);
1433 	}
1434 
1435 	spin_unlock_irqrestore(&priv->lock, flags);
1436 	netif_tx_unlock_bh(dev);
1437 }
1438 
1439 void ipoib_cm_skb_too_long(struct net_device *dev, struct sk_buff *skb,
1440 			   unsigned int mtu)
1441 {
1442 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
1443 	int e = skb_queue_empty(&priv->cm.skb_queue);
1444 
1445 	if (skb_dst(skb))
1446 		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1447 
1448 	skb_queue_tail(&priv->cm.skb_queue, skb);
1449 	if (e)
1450 		queue_work(priv->wq, &priv->cm.skb_task);
1451 }
1452 
1453 static void ipoib_cm_rx_reap(struct work_struct *work)
1454 {
1455 	ipoib_cm_free_rx_reap_list(container_of(work, struct ipoib_dev_priv,
1456 						cm.rx_reap_task)->dev);
1457 }
1458 
1459 static void ipoib_cm_stale_task(struct work_struct *work)
1460 {
1461 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
1462 						   cm.stale_task.work);
1463 	struct ipoib_cm_rx *p;
1464 	int ret;
1465 
1466 	spin_lock_irq(&priv->lock);
1467 	while (!list_empty(&priv->cm.passive_ids)) {
1468 		/* List is sorted by LRU, start from tail,
1469 		 * stop when we see a recently used entry */
1470 		p = list_entry(priv->cm.passive_ids.prev, typeof(*p), list);
1471 		if (time_before_eq(jiffies, p->jiffies + IPOIB_CM_RX_TIMEOUT))
1472 			break;
1473 		list_move(&p->list, &priv->cm.rx_error_list);
1474 		p->state = IPOIB_CM_RX_ERROR;
1475 		spin_unlock_irq(&priv->lock);
1476 		ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
1477 		if (ret)
1478 			ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
1479 		spin_lock_irq(&priv->lock);
1480 	}
1481 
1482 	if (!list_empty(&priv->cm.passive_ids))
1483 		queue_delayed_work(priv->wq,
1484 				   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
1485 	spin_unlock_irq(&priv->lock);
1486 }
1487 
1488 static ssize_t show_mode(struct device *d, struct device_attribute *attr,
1489 			 char *buf)
1490 {
1491 	struct net_device *dev = to_net_dev(d);
1492 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
1493 
1494 	if (test_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags))
1495 		return sprintf(buf, "connected\n");
1496 	else
1497 		return sprintf(buf, "datagram\n");
1498 }
1499 
1500 static ssize_t set_mode(struct device *d, struct device_attribute *attr,
1501 			const char *buf, size_t count)
1502 {
1503 	struct net_device *dev = to_net_dev(d);
1504 	int ret;
1505 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
1506 
1507 	if (test_bit(IPOIB_FLAG_GOING_DOWN, &priv->flags))
1508 		return -EPERM;
1509 
1510 	if (!rtnl_trylock())
1511 		return restart_syscall();
1512 
1513 	ret = ipoib_set_mode(dev, buf);
1514 
1515 	/* The assumption is that the function ipoib_set_mode returned
1516 	 * with the rtnl held by it, if not the value -EBUSY returned,
1517 	 * then no need to rtnl_unlock
1518 	 */
1519 	if (ret != -EBUSY)
1520 		rtnl_unlock();
1521 
1522 	return (!ret || ret == -EBUSY) ? count : ret;
1523 }
1524 
1525 static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, show_mode, set_mode);
1526 
1527 int ipoib_cm_add_mode_attr(struct net_device *dev)
1528 {
1529 	return device_create_file(&dev->dev, &dev_attr_mode);
1530 }
1531 
1532 static void ipoib_cm_create_srq(struct net_device *dev, int max_sge)
1533 {
1534 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
1535 	struct ib_srq_init_attr srq_init_attr = {
1536 		.srq_type = IB_SRQT_BASIC,
1537 		.attr = {
1538 			.max_wr  = ipoib_recvq_size,
1539 			.max_sge = max_sge
1540 		}
1541 	};
1542 
1543 	priv->cm.srq = ib_create_srq(priv->pd, &srq_init_attr);
1544 	if (IS_ERR(priv->cm.srq)) {
1545 		if (PTR_ERR(priv->cm.srq) != -ENOSYS)
1546 			printk(KERN_WARNING "%s: failed to allocate SRQ, error %ld\n",
1547 			       priv->ca->name, PTR_ERR(priv->cm.srq));
1548 		priv->cm.srq = NULL;
1549 		return;
1550 	}
1551 
1552 	priv->cm.srq_ring = vzalloc(ipoib_recvq_size * sizeof *priv->cm.srq_ring);
1553 	if (!priv->cm.srq_ring) {
1554 		ib_destroy_srq(priv->cm.srq);
1555 		priv->cm.srq = NULL;
1556 		return;
1557 	}
1558 
1559 }
1560 
1561 int ipoib_cm_dev_init(struct net_device *dev)
1562 {
1563 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
1564 	int max_srq_sge, i;
1565 
1566 	INIT_LIST_HEAD(&priv->cm.passive_ids);
1567 	INIT_LIST_HEAD(&priv->cm.reap_list);
1568 	INIT_LIST_HEAD(&priv->cm.start_list);
1569 	INIT_LIST_HEAD(&priv->cm.rx_error_list);
1570 	INIT_LIST_HEAD(&priv->cm.rx_flush_list);
1571 	INIT_LIST_HEAD(&priv->cm.rx_drain_list);
1572 	INIT_LIST_HEAD(&priv->cm.rx_reap_list);
1573 	INIT_WORK(&priv->cm.start_task, ipoib_cm_tx_start);
1574 	INIT_WORK(&priv->cm.reap_task, ipoib_cm_tx_reap);
1575 	INIT_WORK(&priv->cm.skb_task, ipoib_cm_skb_reap);
1576 	INIT_WORK(&priv->cm.rx_reap_task, ipoib_cm_rx_reap);
1577 	INIT_DELAYED_WORK(&priv->cm.stale_task, ipoib_cm_stale_task);
1578 
1579 	skb_queue_head_init(&priv->cm.skb_queue);
1580 
1581 	ipoib_dbg(priv, "max_srq_sge=%d\n", priv->ca->attrs.max_srq_sge);
1582 
1583 	max_srq_sge = min_t(int, IPOIB_CM_RX_SG, priv->ca->attrs.max_srq_sge);
1584 	ipoib_cm_create_srq(dev, max_srq_sge);
1585 	if (ipoib_cm_has_srq(dev)) {
1586 		priv->cm.max_cm_mtu = max_srq_sge * PAGE_SIZE - 0x10;
1587 		priv->cm.num_frags  = max_srq_sge;
1588 		ipoib_dbg(priv, "max_cm_mtu = 0x%x, num_frags=%d\n",
1589 			  priv->cm.max_cm_mtu, priv->cm.num_frags);
1590 	} else {
1591 		priv->cm.max_cm_mtu = IPOIB_CM_MTU;
1592 		priv->cm.num_frags  = IPOIB_CM_RX_SG;
1593 	}
1594 
1595 	ipoib_cm_init_rx_wr(dev, &priv->cm.rx_wr, priv->cm.rx_sge);
1596 
1597 	if (ipoib_cm_has_srq(dev)) {
1598 		for (i = 0; i < ipoib_recvq_size; ++i) {
1599 			if (!ipoib_cm_alloc_rx_skb(dev, priv->cm.srq_ring, i,
1600 						   priv->cm.num_frags - 1,
1601 						   priv->cm.srq_ring[i].mapping,
1602 						   GFP_KERNEL)) {
1603 				ipoib_warn(priv, "failed to allocate "
1604 					   "receive buffer %d\n", i);
1605 				ipoib_cm_dev_cleanup(dev);
1606 				return -ENOMEM;
1607 			}
1608 
1609 			if (ipoib_cm_post_receive_srq(dev, i)) {
1610 				ipoib_warn(priv, "ipoib_cm_post_receive_srq "
1611 					   "failed for buf %d\n", i);
1612 				ipoib_cm_dev_cleanup(dev);
1613 				return -EIO;
1614 			}
1615 		}
1616 	}
1617 
1618 	priv->dev->dev_addr[0] = IPOIB_FLAGS_RC;
1619 	return 0;
1620 }
1621 
1622 void ipoib_cm_dev_cleanup(struct net_device *dev)
1623 {
1624 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
1625 	int ret;
1626 
1627 	if (!priv->cm.srq)
1628 		return;
1629 
1630 	ipoib_dbg(priv, "Cleanup ipoib connected mode.\n");
1631 
1632 	ret = ib_destroy_srq(priv->cm.srq);
1633 	if (ret)
1634 		ipoib_warn(priv, "ib_destroy_srq failed: %d\n", ret);
1635 
1636 	priv->cm.srq = NULL;
1637 	if (!priv->cm.srq_ring)
1638 		return;
1639 
1640 	ipoib_cm_free_rx_ring(dev, priv->cm.srq_ring);
1641 	priv->cm.srq_ring = NULL;
1642 }
1643