1 // SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
2 
3 /* Authors: Bernard Metzler <bmt@zurich.ibm.com> */
4 /* Copyright (c) 2008-2019, IBM Corporation */
5 
6 #include <linux/init.h>
7 #include <linux/errno.h>
8 #include <linux/netdevice.h>
9 #include <linux/inetdevice.h>
10 #include <net/net_namespace.h>
11 #include <linux/rtnetlink.h>
12 #include <linux/if_arp.h>
13 #include <linux/list.h>
14 #include <linux/kernel.h>
15 #include <linux/sched.h>
16 #include <linux/module.h>
17 #include <linux/dma-mapping.h>
18 
19 #include <net/addrconf.h>
20 #include <rdma/ib_verbs.h>
21 #include <rdma/ib_user_verbs.h>
22 #include <rdma/rdma_netlink.h>
23 #include <linux/kthread.h>
24 
25 #include "siw.h"
26 #include "siw_verbs.h"
27 
28 MODULE_AUTHOR("Bernard Metzler");
29 MODULE_DESCRIPTION("Software iWARP Driver");
30 MODULE_LICENSE("Dual BSD/GPL");
31 
32 /* transmit from user buffer, if possible */
33 const bool zcopy_tx = true;
34 
35 /* Restrict usage of GSO, if hardware peer iwarp is unable to process
36  * large packets. try_gso = true lets siw try to use local GSO,
37  * if peer agrees.  Not using GSO severly limits siw maximum tx bandwidth.
38  */
39 const bool try_gso;
40 
41 /* Attach siw also with loopback devices */
42 const bool loopback_enabled = true;
43 
44 /* We try to negotiate CRC on, if true */
45 const bool mpa_crc_required;
46 
47 /* MPA CRC on/off enforced */
48 const bool mpa_crc_strict;
49 
50 /* Control TCP_NODELAY socket option */
51 const bool siw_tcp_nagle;
52 
53 /* Select MPA version to be used during connection setup */
54 u_char mpa_version = MPA_REVISION_2;
55 
56 /* Selects MPA P2P mode (additional handshake during connection
57  * setup, if true.
58  */
59 const bool peer_to_peer;
60 
61 struct task_struct *siw_tx_thread[NR_CPUS];
62 struct crypto_shash *siw_crypto_shash;
63 
64 static int siw_device_register(struct siw_device *sdev, const char *name)
65 {
66 	struct ib_device *base_dev = &sdev->base_dev;
67 	static int dev_id = 1;
68 	int rv;
69 
70 	sdev->vendor_part_id = dev_id++;
71 
72 	rv = ib_register_device(base_dev, name, NULL);
73 	if (rv) {
74 		pr_warn("siw: device registration error %d\n", rv);
75 		return rv;
76 	}
77 
78 	siw_dbg(base_dev, "HWaddr=%pM\n", sdev->netdev->dev_addr);
79 
80 	return 0;
81 }
82 
83 static void siw_device_cleanup(struct ib_device *base_dev)
84 {
85 	struct siw_device *sdev = to_siw_dev(base_dev);
86 
87 	xa_destroy(&sdev->qp_xa);
88 	xa_destroy(&sdev->mem_xa);
89 }
90 
91 static int siw_create_tx_threads(void)
92 {
93 	int cpu, assigned = 0;
94 
95 	for_each_online_cpu(cpu) {
96 		/* Skip HT cores */
97 		if (cpu % cpumask_weight(topology_sibling_cpumask(cpu)))
98 			continue;
99 
100 		siw_tx_thread[cpu] =
101 			kthread_create(siw_run_sq, (unsigned long *)(long)cpu,
102 				       "siw_tx/%d", cpu);
103 		if (IS_ERR(siw_tx_thread[cpu])) {
104 			siw_tx_thread[cpu] = NULL;
105 			continue;
106 		}
107 		kthread_bind(siw_tx_thread[cpu], cpu);
108 
109 		wake_up_process(siw_tx_thread[cpu]);
110 		assigned++;
111 	}
112 	return assigned;
113 }
114 
115 static int siw_dev_qualified(struct net_device *netdev)
116 {
117 	/*
118 	 * Additional hardware support can be added here
119 	 * (e.g. ARPHRD_FDDI, ARPHRD_ATM, ...) - see
120 	 * <linux/if_arp.h> for type identifiers.
121 	 */
122 	if (netdev->type == ARPHRD_ETHER || netdev->type == ARPHRD_IEEE802 ||
123 	    (netdev->type == ARPHRD_LOOPBACK && loopback_enabled))
124 		return 1;
125 
126 	return 0;
127 }
128 
129 static DEFINE_PER_CPU(atomic_t, siw_use_cnt);
130 
131 static struct {
132 	struct cpumask **tx_valid_cpus;
133 	int num_nodes;
134 } siw_cpu_info;
135 
136 static int siw_init_cpulist(void)
137 {
138 	int i, num_nodes = num_possible_nodes();
139 
140 	memset(siw_tx_thread, 0, sizeof(siw_tx_thread));
141 
142 	siw_cpu_info.num_nodes = num_nodes;
143 
144 	siw_cpu_info.tx_valid_cpus =
145 		kcalloc(num_nodes, sizeof(struct cpumask *), GFP_KERNEL);
146 	if (!siw_cpu_info.tx_valid_cpus) {
147 		siw_cpu_info.num_nodes = 0;
148 		return -ENOMEM;
149 	}
150 	for (i = 0; i < siw_cpu_info.num_nodes; i++) {
151 		siw_cpu_info.tx_valid_cpus[i] =
152 			kzalloc(sizeof(struct cpumask), GFP_KERNEL);
153 		if (!siw_cpu_info.tx_valid_cpus[i])
154 			goto out_err;
155 
156 		cpumask_clear(siw_cpu_info.tx_valid_cpus[i]);
157 	}
158 	for_each_possible_cpu(i)
159 		cpumask_set_cpu(i, siw_cpu_info.tx_valid_cpus[cpu_to_node(i)]);
160 
161 	return 0;
162 
163 out_err:
164 	siw_cpu_info.num_nodes = 0;
165 	while (--i >= 0)
166 		kfree(siw_cpu_info.tx_valid_cpus[i]);
167 	kfree(siw_cpu_info.tx_valid_cpus);
168 	siw_cpu_info.tx_valid_cpus = NULL;
169 
170 	return -ENOMEM;
171 }
172 
173 static void siw_destroy_cpulist(void)
174 {
175 	int i = 0;
176 
177 	while (i < siw_cpu_info.num_nodes)
178 		kfree(siw_cpu_info.tx_valid_cpus[i++]);
179 
180 	kfree(siw_cpu_info.tx_valid_cpus);
181 }
182 
183 /*
184  * Choose CPU with least number of active QP's from NUMA node of
185  * TX interface.
186  */
187 int siw_get_tx_cpu(struct siw_device *sdev)
188 {
189 	const struct cpumask *tx_cpumask;
190 	int i, num_cpus, cpu, min_use, node = sdev->numa_node, tx_cpu = -1;
191 
192 	if (node < 0)
193 		tx_cpumask = cpu_online_mask;
194 	else
195 		tx_cpumask = siw_cpu_info.tx_valid_cpus[node];
196 
197 	num_cpus = cpumask_weight(tx_cpumask);
198 	if (!num_cpus) {
199 		/* no CPU on this NUMA node */
200 		tx_cpumask = cpu_online_mask;
201 		num_cpus = cpumask_weight(tx_cpumask);
202 	}
203 	if (!num_cpus)
204 		goto out;
205 
206 	cpu = cpumask_first(tx_cpumask);
207 
208 	for (i = 0, min_use = SIW_MAX_QP; i < num_cpus;
209 	     i++, cpu = cpumask_next(cpu, tx_cpumask)) {
210 		int usage;
211 
212 		/* Skip any cores which have no TX thread */
213 		if (!siw_tx_thread[cpu])
214 			continue;
215 
216 		usage = atomic_read(&per_cpu(siw_use_cnt, cpu));
217 		if (usage <= min_use) {
218 			tx_cpu = cpu;
219 			min_use = usage;
220 		}
221 	}
222 	siw_dbg(&sdev->base_dev,
223 		"tx cpu %d, node %d, %d qp's\n", tx_cpu, node, min_use);
224 
225 out:
226 	if (tx_cpu >= 0)
227 		atomic_inc(&per_cpu(siw_use_cnt, tx_cpu));
228 	else
229 		pr_warn("siw: no tx cpu found\n");
230 
231 	return tx_cpu;
232 }
233 
234 void siw_put_tx_cpu(int cpu)
235 {
236 	atomic_dec(&per_cpu(siw_use_cnt, cpu));
237 }
238 
239 static struct ib_qp *siw_get_base_qp(struct ib_device *base_dev, int id)
240 {
241 	struct siw_qp *qp = siw_qp_id2obj(to_siw_dev(base_dev), id);
242 
243 	if (qp) {
244 		/*
245 		 * siw_qp_id2obj() increments object reference count
246 		 */
247 		siw_qp_put(qp);
248 		return &qp->base_qp;
249 	}
250 	return NULL;
251 }
252 
253 static const struct ib_device_ops siw_device_ops = {
254 	.owner = THIS_MODULE,
255 	.uverbs_abi_ver = SIW_ABI_VERSION,
256 	.driver_id = RDMA_DRIVER_SIW,
257 
258 	.alloc_mr = siw_alloc_mr,
259 	.alloc_pd = siw_alloc_pd,
260 	.alloc_ucontext = siw_alloc_ucontext,
261 	.create_cq = siw_create_cq,
262 	.create_qp = siw_create_qp,
263 	.create_srq = siw_create_srq,
264 	.dealloc_driver = siw_device_cleanup,
265 	.dealloc_pd = siw_dealloc_pd,
266 	.dealloc_ucontext = siw_dealloc_ucontext,
267 	.dereg_mr = siw_dereg_mr,
268 	.destroy_cq = siw_destroy_cq,
269 	.destroy_qp = siw_destroy_qp,
270 	.destroy_srq = siw_destroy_srq,
271 	.get_dma_mr = siw_get_dma_mr,
272 	.get_port_immutable = siw_get_port_immutable,
273 	.iw_accept = siw_accept,
274 	.iw_add_ref = siw_qp_get_ref,
275 	.iw_connect = siw_connect,
276 	.iw_create_listen = siw_create_listen,
277 	.iw_destroy_listen = siw_destroy_listen,
278 	.iw_get_qp = siw_get_base_qp,
279 	.iw_reject = siw_reject,
280 	.iw_rem_ref = siw_qp_put_ref,
281 	.map_mr_sg = siw_map_mr_sg,
282 	.mmap = siw_mmap,
283 	.mmap_free = siw_mmap_free,
284 	.modify_qp = siw_verbs_modify_qp,
285 	.modify_srq = siw_modify_srq,
286 	.poll_cq = siw_poll_cq,
287 	.post_recv = siw_post_receive,
288 	.post_send = siw_post_send,
289 	.post_srq_recv = siw_post_srq_recv,
290 	.query_device = siw_query_device,
291 	.query_gid = siw_query_gid,
292 	.query_port = siw_query_port,
293 	.query_qp = siw_query_qp,
294 	.query_srq = siw_query_srq,
295 	.req_notify_cq = siw_req_notify_cq,
296 	.reg_user_mr = siw_reg_user_mr,
297 
298 	INIT_RDMA_OBJ_SIZE(ib_cq, siw_cq, base_cq),
299 	INIT_RDMA_OBJ_SIZE(ib_pd, siw_pd, base_pd),
300 	INIT_RDMA_OBJ_SIZE(ib_srq, siw_srq, base_srq),
301 	INIT_RDMA_OBJ_SIZE(ib_ucontext, siw_ucontext, base_ucontext),
302 };
303 
304 static struct siw_device *siw_device_create(struct net_device *netdev)
305 {
306 	struct siw_device *sdev = NULL;
307 	struct ib_device *base_dev;
308 	struct device *parent = netdev->dev.parent;
309 	u64 dma_mask;
310 	int rv;
311 
312 	if (!parent) {
313 		/*
314 		 * The loopback device has no parent device,
315 		 * so it appears as a top-level device. To support
316 		 * loopback device connectivity, take this device
317 		 * as the parent device. Skip all other devices
318 		 * w/o parent device.
319 		 */
320 		if (netdev->type != ARPHRD_LOOPBACK) {
321 			pr_warn("siw: device %s error: no parent device\n",
322 				netdev->name);
323 			return NULL;
324 		}
325 		parent = &netdev->dev;
326 	}
327 	sdev = ib_alloc_device(siw_device, base_dev);
328 	if (!sdev)
329 		return NULL;
330 
331 	base_dev = &sdev->base_dev;
332 
333 	sdev->netdev = netdev;
334 
335 	if (netdev->type != ARPHRD_LOOPBACK) {
336 		addrconf_addr_eui48((unsigned char *)&base_dev->node_guid,
337 				    netdev->dev_addr);
338 	} else {
339 		/*
340 		 * The loopback device does not have a HW address,
341 		 * but connection mangagement lib expects gid != 0
342 		 */
343 		size_t len = min_t(size_t, strlen(base_dev->name), 6);
344 		char addr[6] = { };
345 
346 		memcpy(addr, base_dev->name, len);
347 		addrconf_addr_eui48((unsigned char *)&base_dev->node_guid,
348 				    addr);
349 	}
350 	base_dev->uverbs_cmd_mask =
351 		(1ull << IB_USER_VERBS_CMD_QUERY_DEVICE) |
352 		(1ull << IB_USER_VERBS_CMD_QUERY_PORT) |
353 		(1ull << IB_USER_VERBS_CMD_GET_CONTEXT) |
354 		(1ull << IB_USER_VERBS_CMD_ALLOC_PD) |
355 		(1ull << IB_USER_VERBS_CMD_DEALLOC_PD) |
356 		(1ull << IB_USER_VERBS_CMD_REG_MR) |
357 		(1ull << IB_USER_VERBS_CMD_DEREG_MR) |
358 		(1ull << IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL) |
359 		(1ull << IB_USER_VERBS_CMD_CREATE_CQ) |
360 		(1ull << IB_USER_VERBS_CMD_POLL_CQ) |
361 		(1ull << IB_USER_VERBS_CMD_REQ_NOTIFY_CQ) |
362 		(1ull << IB_USER_VERBS_CMD_DESTROY_CQ) |
363 		(1ull << IB_USER_VERBS_CMD_CREATE_QP) |
364 		(1ull << IB_USER_VERBS_CMD_QUERY_QP) |
365 		(1ull << IB_USER_VERBS_CMD_MODIFY_QP) |
366 		(1ull << IB_USER_VERBS_CMD_DESTROY_QP) |
367 		(1ull << IB_USER_VERBS_CMD_POST_SEND) |
368 		(1ull << IB_USER_VERBS_CMD_POST_RECV) |
369 		(1ull << IB_USER_VERBS_CMD_CREATE_SRQ) |
370 		(1ull << IB_USER_VERBS_CMD_POST_SRQ_RECV) |
371 		(1ull << IB_USER_VERBS_CMD_MODIFY_SRQ) |
372 		(1ull << IB_USER_VERBS_CMD_QUERY_SRQ) |
373 		(1ull << IB_USER_VERBS_CMD_DESTROY_SRQ);
374 
375 	base_dev->node_type = RDMA_NODE_RNIC;
376 	memcpy(base_dev->node_desc, SIW_NODE_DESC_COMMON,
377 	       sizeof(SIW_NODE_DESC_COMMON));
378 
379 	/*
380 	 * Current model (one-to-one device association):
381 	 * One Softiwarp device per net_device or, equivalently,
382 	 * per physical port.
383 	 */
384 	base_dev->phys_port_cnt = 1;
385 	base_dev->dev.parent = parent;
386 	base_dev->dev.dma_parms = &sdev->dma_parms;
387 	dma_set_max_seg_size(&base_dev->dev, UINT_MAX);
388 	dma_mask = IS_ENABLED(CONFIG_64BIT) ? DMA_BIT_MASK(64) : DMA_BIT_MASK(32);
389 	if (dma_coerce_mask_and_coherent(&base_dev->dev, dma_mask))
390 		goto error;
391 
392 	base_dev->num_comp_vectors = num_possible_cpus();
393 
394 	xa_init_flags(&sdev->qp_xa, XA_FLAGS_ALLOC1);
395 	xa_init_flags(&sdev->mem_xa, XA_FLAGS_ALLOC1);
396 
397 	ib_set_device_ops(base_dev, &siw_device_ops);
398 	rv = ib_device_set_netdev(base_dev, netdev, 1);
399 	if (rv)
400 		goto error;
401 
402 	memcpy(base_dev->iw_ifname, netdev->name,
403 	       sizeof(base_dev->iw_ifname));
404 
405 	/* Disable TCP port mapping */
406 	base_dev->iw_driver_flags = IW_F_NO_PORT_MAP,
407 
408 	sdev->attrs.max_qp = SIW_MAX_QP;
409 	sdev->attrs.max_qp_wr = SIW_MAX_QP_WR;
410 	sdev->attrs.max_ord = SIW_MAX_ORD_QP;
411 	sdev->attrs.max_ird = SIW_MAX_IRD_QP;
412 	sdev->attrs.max_sge = SIW_MAX_SGE;
413 	sdev->attrs.max_sge_rd = SIW_MAX_SGE_RD;
414 	sdev->attrs.max_cq = SIW_MAX_CQ;
415 	sdev->attrs.max_cqe = SIW_MAX_CQE;
416 	sdev->attrs.max_mr = SIW_MAX_MR;
417 	sdev->attrs.max_pd = SIW_MAX_PD;
418 	sdev->attrs.max_mw = SIW_MAX_MW;
419 	sdev->attrs.max_srq = SIW_MAX_SRQ;
420 	sdev->attrs.max_srq_wr = SIW_MAX_SRQ_WR;
421 	sdev->attrs.max_srq_sge = SIW_MAX_SGE;
422 
423 	INIT_LIST_HEAD(&sdev->cep_list);
424 	INIT_LIST_HEAD(&sdev->qp_list);
425 
426 	atomic_set(&sdev->num_ctx, 0);
427 	atomic_set(&sdev->num_srq, 0);
428 	atomic_set(&sdev->num_qp, 0);
429 	atomic_set(&sdev->num_cq, 0);
430 	atomic_set(&sdev->num_mr, 0);
431 	atomic_set(&sdev->num_pd, 0);
432 
433 	sdev->numa_node = dev_to_node(parent);
434 	spin_lock_init(&sdev->lock);
435 
436 	return sdev;
437 error:
438 	ib_dealloc_device(base_dev);
439 
440 	return NULL;
441 }
442 
443 /*
444  * Network link becomes unavailable. Mark all
445  * affected QP's accordingly.
446  */
447 static void siw_netdev_down(struct work_struct *work)
448 {
449 	struct siw_device *sdev =
450 		container_of(work, struct siw_device, netdev_down);
451 
452 	struct siw_qp_attrs qp_attrs;
453 	struct list_head *pos, *tmp;
454 
455 	memset(&qp_attrs, 0, sizeof(qp_attrs));
456 	qp_attrs.state = SIW_QP_STATE_ERROR;
457 
458 	list_for_each_safe(pos, tmp, &sdev->qp_list) {
459 		struct siw_qp *qp = list_entry(pos, struct siw_qp, devq);
460 
461 		down_write(&qp->state_lock);
462 		WARN_ON(siw_qp_modify(qp, &qp_attrs, SIW_QP_ATTR_STATE));
463 		up_write(&qp->state_lock);
464 	}
465 	ib_device_put(&sdev->base_dev);
466 }
467 
468 static void siw_device_goes_down(struct siw_device *sdev)
469 {
470 	if (ib_device_try_get(&sdev->base_dev)) {
471 		INIT_WORK(&sdev->netdev_down, siw_netdev_down);
472 		schedule_work(&sdev->netdev_down);
473 	}
474 }
475 
476 static int siw_netdev_event(struct notifier_block *nb, unsigned long event,
477 			    void *arg)
478 {
479 	struct net_device *netdev = netdev_notifier_info_to_dev(arg);
480 	struct ib_device *base_dev;
481 	struct siw_device *sdev;
482 
483 	dev_dbg(&netdev->dev, "siw: event %lu\n", event);
484 
485 	if (dev_net(netdev) != &init_net)
486 		return NOTIFY_OK;
487 
488 	base_dev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_SIW);
489 	if (!base_dev)
490 		return NOTIFY_OK;
491 
492 	sdev = to_siw_dev(base_dev);
493 
494 	switch (event) {
495 	case NETDEV_UP:
496 		sdev->state = IB_PORT_ACTIVE;
497 		siw_port_event(sdev, 1, IB_EVENT_PORT_ACTIVE);
498 		break;
499 
500 	case NETDEV_GOING_DOWN:
501 		siw_device_goes_down(sdev);
502 		break;
503 
504 	case NETDEV_DOWN:
505 		sdev->state = IB_PORT_DOWN;
506 		siw_port_event(sdev, 1, IB_EVENT_PORT_ERR);
507 		break;
508 
509 	case NETDEV_REGISTER:
510 		/*
511 		 * Device registration now handled only by
512 		 * rdma netlink commands. So it shall be impossible
513 		 * to end up here with a valid siw device.
514 		 */
515 		siw_dbg(base_dev, "unexpected NETDEV_REGISTER event\n");
516 		break;
517 
518 	case NETDEV_UNREGISTER:
519 		ib_unregister_device_queued(&sdev->base_dev);
520 		break;
521 
522 	case NETDEV_CHANGEADDR:
523 		siw_port_event(sdev, 1, IB_EVENT_LID_CHANGE);
524 		break;
525 	/*
526 	 * Todo: Below netdev events are currently not handled.
527 	 */
528 	case NETDEV_CHANGEMTU:
529 	case NETDEV_CHANGE:
530 		break;
531 
532 	default:
533 		break;
534 	}
535 	ib_device_put(&sdev->base_dev);
536 
537 	return NOTIFY_OK;
538 }
539 
540 static struct notifier_block siw_netdev_nb = {
541 	.notifier_call = siw_netdev_event,
542 };
543 
544 static int siw_newlink(const char *basedev_name, struct net_device *netdev)
545 {
546 	struct ib_device *base_dev;
547 	struct siw_device *sdev = NULL;
548 	int rv = -ENOMEM;
549 
550 	if (!siw_dev_qualified(netdev))
551 		return -EINVAL;
552 
553 	base_dev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_SIW);
554 	if (base_dev) {
555 		ib_device_put(base_dev);
556 		return -EEXIST;
557 	}
558 	sdev = siw_device_create(netdev);
559 	if (sdev) {
560 		dev_dbg(&netdev->dev, "siw: new device\n");
561 
562 		if (netif_running(netdev) && netif_carrier_ok(netdev))
563 			sdev->state = IB_PORT_ACTIVE;
564 		else
565 			sdev->state = IB_PORT_DOWN;
566 
567 		rv = siw_device_register(sdev, basedev_name);
568 		if (rv)
569 			ib_dealloc_device(&sdev->base_dev);
570 	}
571 	return rv;
572 }
573 
574 static struct rdma_link_ops siw_link_ops = {
575 	.type = "siw",
576 	.newlink = siw_newlink,
577 };
578 
579 /*
580  * siw_init_module - Initialize Softiwarp module and register with netdev
581  *                   subsystem.
582  */
583 static __init int siw_init_module(void)
584 {
585 	int rv;
586 	int nr_cpu;
587 
588 	if (SENDPAGE_THRESH < SIW_MAX_INLINE) {
589 		pr_info("siw: sendpage threshold too small: %u\n",
590 			(int)SENDPAGE_THRESH);
591 		rv = -EINVAL;
592 		goto out_error;
593 	}
594 	rv = siw_init_cpulist();
595 	if (rv)
596 		goto out_error;
597 
598 	rv = siw_cm_init();
599 	if (rv)
600 		goto out_error;
601 
602 	if (!siw_create_tx_threads()) {
603 		pr_info("siw: Could not start any TX thread\n");
604 		rv = -ENOMEM;
605 		goto out_error;
606 	}
607 	/*
608 	 * Locate CRC32 algorithm. If unsuccessful, fail
609 	 * loading siw only, if CRC is required.
610 	 */
611 	siw_crypto_shash = crypto_alloc_shash("crc32c", 0, 0);
612 	if (IS_ERR(siw_crypto_shash)) {
613 		pr_info("siw: Loading CRC32c failed: %ld\n",
614 			PTR_ERR(siw_crypto_shash));
615 		siw_crypto_shash = NULL;
616 		if (mpa_crc_required) {
617 			rv = -EOPNOTSUPP;
618 			goto out_error;
619 		}
620 	}
621 	rv = register_netdevice_notifier(&siw_netdev_nb);
622 	if (rv)
623 		goto out_error;
624 
625 	rdma_link_register(&siw_link_ops);
626 
627 	pr_info("SoftiWARP attached\n");
628 	return 0;
629 
630 out_error:
631 	for (nr_cpu = 0; nr_cpu < nr_cpu_ids; nr_cpu++) {
632 		if (siw_tx_thread[nr_cpu]) {
633 			siw_stop_tx_thread(nr_cpu);
634 			siw_tx_thread[nr_cpu] = NULL;
635 		}
636 	}
637 	if (siw_crypto_shash)
638 		crypto_free_shash(siw_crypto_shash);
639 
640 	pr_info("SoftIWARP attach failed. Error: %d\n", rv);
641 
642 	siw_cm_exit();
643 	siw_destroy_cpulist();
644 
645 	return rv;
646 }
647 
648 static void __exit siw_exit_module(void)
649 {
650 	int cpu;
651 
652 	for_each_possible_cpu(cpu) {
653 		if (siw_tx_thread[cpu]) {
654 			siw_stop_tx_thread(cpu);
655 			siw_tx_thread[cpu] = NULL;
656 		}
657 	}
658 	unregister_netdevice_notifier(&siw_netdev_nb);
659 	rdma_link_unregister(&siw_link_ops);
660 	ib_unregister_driver(RDMA_DRIVER_SIW);
661 
662 	siw_cm_exit();
663 
664 	siw_destroy_cpulist();
665 
666 	if (siw_crypto_shash)
667 		crypto_free_shash(siw_crypto_shash);
668 
669 	pr_info("SoftiWARP detached\n");
670 }
671 
672 module_init(siw_init_module);
673 module_exit(siw_exit_module);
674 
675 MODULE_ALIAS_RDMA_LINK("siw");
676