xref: /linux/drivers/infiniband/sw/siw/siw_main.c (revision 9a6b55ac)
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 	rv = ib_register_device(base_dev, name);
71 	if (rv) {
72 		pr_warn("siw: device registration error %d\n", rv);
73 		return rv;
74 	}
75 	sdev->vendor_part_id = dev_id++;
76 
77 	siw_dbg(base_dev, "HWaddr=%pM\n", sdev->netdev->dev_addr);
78 
79 	return 0;
80 }
81 
82 static void siw_device_cleanup(struct ib_device *base_dev)
83 {
84 	struct siw_device *sdev = to_siw_dev(base_dev);
85 
86 	xa_destroy(&sdev->qp_xa);
87 	xa_destroy(&sdev->mem_xa);
88 }
89 
90 static int siw_create_tx_threads(void)
91 {
92 	int cpu, assigned = 0;
93 
94 	for_each_online_cpu(cpu) {
95 		/* Skip HT cores */
96 		if (cpu % cpumask_weight(topology_sibling_cpumask(cpu)))
97 			continue;
98 
99 		siw_tx_thread[cpu] =
100 			kthread_create(siw_run_sq, (unsigned long *)(long)cpu,
101 				       "siw_tx/%d", cpu);
102 		if (IS_ERR(siw_tx_thread[cpu])) {
103 			siw_tx_thread[cpu] = NULL;
104 			continue;
105 		}
106 		kthread_bind(siw_tx_thread[cpu], cpu);
107 
108 		wake_up_process(siw_tx_thread[cpu]);
109 		assigned++;
110 	}
111 	return assigned;
112 }
113 
114 static int siw_dev_qualified(struct net_device *netdev)
115 {
116 	/*
117 	 * Additional hardware support can be added here
118 	 * (e.g. ARPHRD_FDDI, ARPHRD_ATM, ...) - see
119 	 * <linux/if_arp.h> for type identifiers.
120 	 */
121 	if (netdev->type == ARPHRD_ETHER || netdev->type == ARPHRD_IEEE802 ||
122 	    (netdev->type == ARPHRD_LOOPBACK && loopback_enabled))
123 		return 1;
124 
125 	return 0;
126 }
127 
128 static DEFINE_PER_CPU(atomic_t, siw_use_cnt);
129 
130 static struct {
131 	struct cpumask **tx_valid_cpus;
132 	int num_nodes;
133 } siw_cpu_info;
134 
135 static int siw_init_cpulist(void)
136 {
137 	int i, num_nodes = num_possible_nodes();
138 
139 	memset(siw_tx_thread, 0, sizeof(siw_tx_thread));
140 
141 	siw_cpu_info.num_nodes = num_nodes;
142 
143 	siw_cpu_info.tx_valid_cpus =
144 		kcalloc(num_nodes, sizeof(struct cpumask *), GFP_KERNEL);
145 	if (!siw_cpu_info.tx_valid_cpus) {
146 		siw_cpu_info.num_nodes = 0;
147 		return -ENOMEM;
148 	}
149 	for (i = 0; i < siw_cpu_info.num_nodes; i++) {
150 		siw_cpu_info.tx_valid_cpus[i] =
151 			kzalloc(sizeof(struct cpumask), GFP_KERNEL);
152 		if (!siw_cpu_info.tx_valid_cpus[i])
153 			goto out_err;
154 
155 		cpumask_clear(siw_cpu_info.tx_valid_cpus[i]);
156 	}
157 	for_each_possible_cpu(i)
158 		cpumask_set_cpu(i, siw_cpu_info.tx_valid_cpus[cpu_to_node(i)]);
159 
160 	return 0;
161 
162 out_err:
163 	siw_cpu_info.num_nodes = 0;
164 	while (--i >= 0)
165 		kfree(siw_cpu_info.tx_valid_cpus[i]);
166 	kfree(siw_cpu_info.tx_valid_cpus);
167 	siw_cpu_info.tx_valid_cpus = NULL;
168 
169 	return -ENOMEM;
170 }
171 
172 static void siw_destroy_cpulist(void)
173 {
174 	int i = 0;
175 
176 	while (i < siw_cpu_info.num_nodes)
177 		kfree(siw_cpu_info.tx_valid_cpus[i++]);
178 
179 	kfree(siw_cpu_info.tx_valid_cpus);
180 }
181 
182 /*
183  * Choose CPU with least number of active QP's from NUMA node of
184  * TX interface.
185  */
186 int siw_get_tx_cpu(struct siw_device *sdev)
187 {
188 	const struct cpumask *tx_cpumask;
189 	int i, num_cpus, cpu, min_use, node = sdev->numa_node, tx_cpu = -1;
190 
191 	if (node < 0)
192 		tx_cpumask = cpu_online_mask;
193 	else
194 		tx_cpumask = siw_cpu_info.tx_valid_cpus[node];
195 
196 	num_cpus = cpumask_weight(tx_cpumask);
197 	if (!num_cpus) {
198 		/* no CPU on this NUMA node */
199 		tx_cpumask = cpu_online_mask;
200 		num_cpus = cpumask_weight(tx_cpumask);
201 	}
202 	if (!num_cpus)
203 		goto out;
204 
205 	cpu = cpumask_first(tx_cpumask);
206 
207 	for (i = 0, min_use = SIW_MAX_QP; i < num_cpus;
208 	     i++, cpu = cpumask_next(cpu, tx_cpumask)) {
209 		int usage;
210 
211 		/* Skip any cores which have no TX thread */
212 		if (!siw_tx_thread[cpu])
213 			continue;
214 
215 		usage = atomic_read(&per_cpu(siw_use_cnt, cpu));
216 		if (usage <= min_use) {
217 			tx_cpu = cpu;
218 			min_use = usage;
219 		}
220 	}
221 	siw_dbg(&sdev->base_dev,
222 		"tx cpu %d, node %d, %d qp's\n", tx_cpu, node, min_use);
223 
224 out:
225 	if (tx_cpu >= 0)
226 		atomic_inc(&per_cpu(siw_use_cnt, tx_cpu));
227 	else
228 		pr_warn("siw: no tx cpu found\n");
229 
230 	return tx_cpu;
231 }
232 
233 void siw_put_tx_cpu(int cpu)
234 {
235 	atomic_dec(&per_cpu(siw_use_cnt, cpu));
236 }
237 
238 static struct ib_qp *siw_get_base_qp(struct ib_device *base_dev, int id)
239 {
240 	struct siw_qp *qp = siw_qp_id2obj(to_siw_dev(base_dev), id);
241 
242 	if (qp) {
243 		/*
244 		 * siw_qp_id2obj() increments object reference count
245 		 */
246 		siw_qp_put(qp);
247 		return qp->ib_qp;
248 	}
249 	return NULL;
250 }
251 
252 static const struct ib_device_ops siw_device_ops = {
253 	.owner = THIS_MODULE,
254 	.uverbs_abi_ver = SIW_ABI_VERSION,
255 	.driver_id = RDMA_DRIVER_SIW,
256 
257 	.alloc_mr = siw_alloc_mr,
258 	.alloc_pd = siw_alloc_pd,
259 	.alloc_ucontext = siw_alloc_ucontext,
260 	.create_cq = siw_create_cq,
261 	.create_qp = siw_create_qp,
262 	.create_srq = siw_create_srq,
263 	.dealloc_driver = siw_device_cleanup,
264 	.dealloc_pd = siw_dealloc_pd,
265 	.dealloc_ucontext = siw_dealloc_ucontext,
266 	.dereg_mr = siw_dereg_mr,
267 	.destroy_cq = siw_destroy_cq,
268 	.destroy_qp = siw_destroy_qp,
269 	.destroy_srq = siw_destroy_srq,
270 	.get_dma_mr = siw_get_dma_mr,
271 	.get_port_immutable = siw_get_port_immutable,
272 	.iw_accept = siw_accept,
273 	.iw_add_ref = siw_qp_get_ref,
274 	.iw_connect = siw_connect,
275 	.iw_create_listen = siw_create_listen,
276 	.iw_destroy_listen = siw_destroy_listen,
277 	.iw_get_qp = siw_get_base_qp,
278 	.iw_reject = siw_reject,
279 	.iw_rem_ref = siw_qp_put_ref,
280 	.map_mr_sg = siw_map_mr_sg,
281 	.mmap = siw_mmap,
282 	.mmap_free = siw_mmap_free,
283 	.modify_qp = siw_verbs_modify_qp,
284 	.modify_srq = siw_modify_srq,
285 	.poll_cq = siw_poll_cq,
286 	.post_recv = siw_post_receive,
287 	.post_send = siw_post_send,
288 	.post_srq_recv = siw_post_srq_recv,
289 	.query_device = siw_query_device,
290 	.query_gid = siw_query_gid,
291 	.query_pkey = siw_query_pkey,
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 	int rv;
310 
311 	if (!parent) {
312 		/*
313 		 * The loopback device has no parent device,
314 		 * so it appears as a top-level device. To support
315 		 * loopback device connectivity, take this device
316 		 * as the parent device. Skip all other devices
317 		 * w/o parent device.
318 		 */
319 		if (netdev->type != ARPHRD_LOOPBACK) {
320 			pr_warn("siw: device %s error: no parent device\n",
321 				netdev->name);
322 			return NULL;
323 		}
324 		parent = &netdev->dev;
325 	}
326 	sdev = ib_alloc_device(siw_device, base_dev);
327 	if (!sdev)
328 		return NULL;
329 
330 	base_dev = &sdev->base_dev;
331 
332 	sdev->netdev = netdev;
333 
334 	if (netdev->type != ARPHRD_LOOPBACK) {
335 		addrconf_addr_eui48((unsigned char *)&base_dev->node_guid,
336 				    netdev->dev_addr);
337 	} else {
338 		/*
339 		 * The loopback device does not have a HW address,
340 		 * but connection mangagement lib expects gid != 0
341 		 */
342 		size_t len = min_t(size_t, strlen(base_dev->name), 6);
343 		char addr[6] = { };
344 
345 		memcpy(addr, base_dev->name, len);
346 		addrconf_addr_eui48((unsigned char *)&base_dev->node_guid,
347 				    addr);
348 	}
349 	base_dev->uverbs_cmd_mask =
350 		(1ull << IB_USER_VERBS_CMD_QUERY_DEVICE) |
351 		(1ull << IB_USER_VERBS_CMD_QUERY_PORT) |
352 		(1ull << IB_USER_VERBS_CMD_GET_CONTEXT) |
353 		(1ull << IB_USER_VERBS_CMD_ALLOC_PD) |
354 		(1ull << IB_USER_VERBS_CMD_DEALLOC_PD) |
355 		(1ull << IB_USER_VERBS_CMD_REG_MR) |
356 		(1ull << IB_USER_VERBS_CMD_DEREG_MR) |
357 		(1ull << IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL) |
358 		(1ull << IB_USER_VERBS_CMD_CREATE_CQ) |
359 		(1ull << IB_USER_VERBS_CMD_POLL_CQ) |
360 		(1ull << IB_USER_VERBS_CMD_REQ_NOTIFY_CQ) |
361 		(1ull << IB_USER_VERBS_CMD_DESTROY_CQ) |
362 		(1ull << IB_USER_VERBS_CMD_CREATE_QP) |
363 		(1ull << IB_USER_VERBS_CMD_QUERY_QP) |
364 		(1ull << IB_USER_VERBS_CMD_MODIFY_QP) |
365 		(1ull << IB_USER_VERBS_CMD_DESTROY_QP) |
366 		(1ull << IB_USER_VERBS_CMD_POST_SEND) |
367 		(1ull << IB_USER_VERBS_CMD_POST_RECV) |
368 		(1ull << IB_USER_VERBS_CMD_CREATE_SRQ) |
369 		(1ull << IB_USER_VERBS_CMD_POST_SRQ_RECV) |
370 		(1ull << IB_USER_VERBS_CMD_MODIFY_SRQ) |
371 		(1ull << IB_USER_VERBS_CMD_QUERY_SRQ) |
372 		(1ull << IB_USER_VERBS_CMD_DESTROY_SRQ);
373 
374 	base_dev->node_type = RDMA_NODE_RNIC;
375 	memcpy(base_dev->node_desc, SIW_NODE_DESC_COMMON,
376 	       sizeof(SIW_NODE_DESC_COMMON));
377 
378 	/*
379 	 * Current model (one-to-one device association):
380 	 * One Softiwarp device per net_device or, equivalently,
381 	 * per physical port.
382 	 */
383 	base_dev->phys_port_cnt = 1;
384 	base_dev->dev.parent = parent;
385 	base_dev->dev.dma_ops = &dma_virt_ops;
386 	base_dev->dev.dma_parms = &sdev->dma_parms;
387 	sdev->dma_parms = (struct device_dma_parameters)
388 		{ .max_segment_size = SZ_2G };
389 	base_dev->num_comp_vectors = num_possible_cpus();
390 
391 	ib_set_device_ops(base_dev, &siw_device_ops);
392 	rv = ib_device_set_netdev(base_dev, netdev, 1);
393 	if (rv)
394 		goto error;
395 
396 	memcpy(base_dev->iw_ifname, netdev->name,
397 	       sizeof(base_dev->iw_ifname));
398 
399 	/* Disable TCP port mapping */
400 	base_dev->iw_driver_flags = IW_F_NO_PORT_MAP,
401 
402 	sdev->attrs.max_qp = SIW_MAX_QP;
403 	sdev->attrs.max_qp_wr = SIW_MAX_QP_WR;
404 	sdev->attrs.max_ord = SIW_MAX_ORD_QP;
405 	sdev->attrs.max_ird = SIW_MAX_IRD_QP;
406 	sdev->attrs.max_sge = SIW_MAX_SGE;
407 	sdev->attrs.max_sge_rd = SIW_MAX_SGE_RD;
408 	sdev->attrs.max_cq = SIW_MAX_CQ;
409 	sdev->attrs.max_cqe = SIW_MAX_CQE;
410 	sdev->attrs.max_mr = SIW_MAX_MR;
411 	sdev->attrs.max_pd = SIW_MAX_PD;
412 	sdev->attrs.max_mw = SIW_MAX_MW;
413 	sdev->attrs.max_fmr = SIW_MAX_FMR;
414 	sdev->attrs.max_srq = SIW_MAX_SRQ;
415 	sdev->attrs.max_srq_wr = SIW_MAX_SRQ_WR;
416 	sdev->attrs.max_srq_sge = SIW_MAX_SGE;
417 
418 	xa_init_flags(&sdev->qp_xa, XA_FLAGS_ALLOC1);
419 	xa_init_flags(&sdev->mem_xa, XA_FLAGS_ALLOC1);
420 
421 	INIT_LIST_HEAD(&sdev->cep_list);
422 	INIT_LIST_HEAD(&sdev->qp_list);
423 
424 	atomic_set(&sdev->num_ctx, 0);
425 	atomic_set(&sdev->num_srq, 0);
426 	atomic_set(&sdev->num_qp, 0);
427 	atomic_set(&sdev->num_cq, 0);
428 	atomic_set(&sdev->num_mr, 0);
429 	atomic_set(&sdev->num_pd, 0);
430 
431 	sdev->numa_node = dev_to_node(parent);
432 	spin_lock_init(&sdev->lock);
433 
434 	return sdev;
435 error:
436 	ib_dealloc_device(base_dev);
437 
438 	return NULL;
439 }
440 
441 /*
442  * Network link becomes unavailable. Mark all
443  * affected QP's accordingly.
444  */
445 static void siw_netdev_down(struct work_struct *work)
446 {
447 	struct siw_device *sdev =
448 		container_of(work, struct siw_device, netdev_down);
449 
450 	struct siw_qp_attrs qp_attrs;
451 	struct list_head *pos, *tmp;
452 
453 	memset(&qp_attrs, 0, sizeof(qp_attrs));
454 	qp_attrs.state = SIW_QP_STATE_ERROR;
455 
456 	list_for_each_safe(pos, tmp, &sdev->qp_list) {
457 		struct siw_qp *qp = list_entry(pos, struct siw_qp, devq);
458 
459 		down_write(&qp->state_lock);
460 		WARN_ON(siw_qp_modify(qp, &qp_attrs, SIW_QP_ATTR_STATE));
461 		up_write(&qp->state_lock);
462 	}
463 	ib_device_put(&sdev->base_dev);
464 }
465 
466 static void siw_device_goes_down(struct siw_device *sdev)
467 {
468 	if (ib_device_try_get(&sdev->base_dev)) {
469 		INIT_WORK(&sdev->netdev_down, siw_netdev_down);
470 		schedule_work(&sdev->netdev_down);
471 	}
472 }
473 
474 static int siw_netdev_event(struct notifier_block *nb, unsigned long event,
475 			    void *arg)
476 {
477 	struct net_device *netdev = netdev_notifier_info_to_dev(arg);
478 	struct ib_device *base_dev;
479 	struct siw_device *sdev;
480 
481 	dev_dbg(&netdev->dev, "siw: event %lu\n", event);
482 
483 	if (dev_net(netdev) != &init_net)
484 		return NOTIFY_OK;
485 
486 	base_dev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_SIW);
487 	if (!base_dev)
488 		return NOTIFY_OK;
489 
490 	sdev = to_siw_dev(base_dev);
491 
492 	switch (event) {
493 	case NETDEV_UP:
494 		sdev->state = IB_PORT_ACTIVE;
495 		siw_port_event(sdev, 1, IB_EVENT_PORT_ACTIVE);
496 		break;
497 
498 	case NETDEV_GOING_DOWN:
499 		siw_device_goes_down(sdev);
500 		break;
501 
502 	case NETDEV_DOWN:
503 		sdev->state = IB_PORT_DOWN;
504 		siw_port_event(sdev, 1, IB_EVENT_PORT_ERR);
505 		break;
506 
507 	case NETDEV_REGISTER:
508 		/*
509 		 * Device registration now handled only by
510 		 * rdma netlink commands. So it shall be impossible
511 		 * to end up here with a valid siw device.
512 		 */
513 		siw_dbg(base_dev, "unexpected NETDEV_REGISTER event\n");
514 		break;
515 
516 	case NETDEV_UNREGISTER:
517 		ib_unregister_device_queued(&sdev->base_dev);
518 		break;
519 
520 	case NETDEV_CHANGEADDR:
521 		siw_port_event(sdev, 1, IB_EVENT_LID_CHANGE);
522 		break;
523 	/*
524 	 * Todo: Below netdev events are currently not handled.
525 	 */
526 	case NETDEV_CHANGEMTU:
527 	case NETDEV_CHANGE:
528 		break;
529 
530 	default:
531 		break;
532 	}
533 	ib_device_put(&sdev->base_dev);
534 
535 	return NOTIFY_OK;
536 }
537 
538 static struct notifier_block siw_netdev_nb = {
539 	.notifier_call = siw_netdev_event,
540 };
541 
542 static int siw_newlink(const char *basedev_name, struct net_device *netdev)
543 {
544 	struct ib_device *base_dev;
545 	struct siw_device *sdev = NULL;
546 	int rv = -ENOMEM;
547 
548 	if (!siw_dev_qualified(netdev))
549 		return -EINVAL;
550 
551 	base_dev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_SIW);
552 	if (base_dev) {
553 		ib_device_put(base_dev);
554 		return -EEXIST;
555 	}
556 	sdev = siw_device_create(netdev);
557 	if (sdev) {
558 		dev_dbg(&netdev->dev, "siw: new device\n");
559 
560 		if (netif_running(netdev) && netif_carrier_ok(netdev))
561 			sdev->state = IB_PORT_ACTIVE;
562 		else
563 			sdev->state = IB_PORT_DOWN;
564 
565 		rv = siw_device_register(sdev, basedev_name);
566 		if (rv)
567 			ib_dealloc_device(&sdev->base_dev);
568 	}
569 	return rv;
570 }
571 
572 static struct rdma_link_ops siw_link_ops = {
573 	.type = "siw",
574 	.newlink = siw_newlink,
575 };
576 
577 /*
578  * siw_init_module - Initialize Softiwarp module and register with netdev
579  *                   subsystem.
580  */
581 static __init int siw_init_module(void)
582 {
583 	int rv;
584 	int nr_cpu;
585 
586 	if (SENDPAGE_THRESH < SIW_MAX_INLINE) {
587 		pr_info("siw: sendpage threshold too small: %u\n",
588 			(int)SENDPAGE_THRESH);
589 		rv = -EINVAL;
590 		goto out_error;
591 	}
592 	rv = siw_init_cpulist();
593 	if (rv)
594 		goto out_error;
595 
596 	rv = siw_cm_init();
597 	if (rv)
598 		goto out_error;
599 
600 	if (!siw_create_tx_threads()) {
601 		pr_info("siw: Could not start any TX thread\n");
602 		rv = -ENOMEM;
603 		goto out_error;
604 	}
605 	/*
606 	 * Locate CRC32 algorithm. If unsuccessful, fail
607 	 * loading siw only, if CRC is required.
608 	 */
609 	siw_crypto_shash = crypto_alloc_shash("crc32c", 0, 0);
610 	if (IS_ERR(siw_crypto_shash)) {
611 		pr_info("siw: Loading CRC32c failed: %ld\n",
612 			PTR_ERR(siw_crypto_shash));
613 		siw_crypto_shash = NULL;
614 		if (mpa_crc_required) {
615 			rv = -EOPNOTSUPP;
616 			goto out_error;
617 		}
618 	}
619 	rv = register_netdevice_notifier(&siw_netdev_nb);
620 	if (rv)
621 		goto out_error;
622 
623 	rdma_link_register(&siw_link_ops);
624 
625 	pr_info("SoftiWARP attached\n");
626 	return 0;
627 
628 out_error:
629 	for (nr_cpu = 0; nr_cpu < nr_cpu_ids; nr_cpu++) {
630 		if (siw_tx_thread[nr_cpu]) {
631 			siw_stop_tx_thread(nr_cpu);
632 			siw_tx_thread[nr_cpu] = NULL;
633 		}
634 	}
635 	if (siw_crypto_shash)
636 		crypto_free_shash(siw_crypto_shash);
637 
638 	pr_info("SoftIWARP attach failed. Error: %d\n", rv);
639 
640 	siw_cm_exit();
641 	siw_destroy_cpulist();
642 
643 	return rv;
644 }
645 
646 static void __exit siw_exit_module(void)
647 {
648 	int cpu;
649 
650 	for_each_possible_cpu(cpu) {
651 		if (siw_tx_thread[cpu]) {
652 			siw_stop_tx_thread(cpu);
653 			siw_tx_thread[cpu] = NULL;
654 		}
655 	}
656 	unregister_netdevice_notifier(&siw_netdev_nb);
657 	rdma_link_unregister(&siw_link_ops);
658 	ib_unregister_driver(RDMA_DRIVER_SIW);
659 
660 	siw_cm_exit();
661 
662 	siw_destroy_cpulist();
663 
664 	if (siw_crypto_shash)
665 		crypto_free_shash(siw_crypto_shash);
666 
667 	pr_info("SoftiWARP detached\n");
668 }
669 
670 module_init(siw_init_module);
671 module_exit(siw_exit_module);
672 
673 MODULE_ALIAS_RDMA_LINK("siw");
674