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 <rdma/ib_verbs.h>
20 #include <rdma/ib_user_verbs.h>
21 #include <rdma/rdma_netlink.h>
22 #include <linux/kthread.h>
23 
24 #include "siw.h"
25 #include "siw_verbs.h"
26 
27 MODULE_AUTHOR("Bernard Metzler");
28 MODULE_DESCRIPTION("Software iWARP Driver");
29 MODULE_LICENSE("Dual BSD/GPL");
30 
31 /* transmit from user buffer, if possible */
32 const bool zcopy_tx = true;
33 
34 /* Restrict usage of GSO, if hardware peer iwarp is unable to process
35  * large packets. try_gso = true lets siw try to use local GSO,
36  * if peer agrees.  Not using GSO severly limits siw maximum tx bandwidth.
37  */
38 const bool try_gso;
39 
40 /* Attach siw also with loopback devices */
41 const bool loopback_enabled = true;
42 
43 /* We try to negotiate CRC on, if true */
44 const bool mpa_crc_required;
45 
46 /* MPA CRC on/off enforced */
47 const bool mpa_crc_strict;
48 
49 /* Control TCP_NODELAY socket option */
50 const bool siw_tcp_nagle;
51 
52 /* Select MPA version to be used during connection setup */
53 u_char mpa_version = MPA_REVISION_2;
54 
55 /* Selects MPA P2P mode (additional handshake during connection
56  * setup, if true.
57  */
58 const bool peer_to_peer;
59 
60 struct task_struct *siw_tx_thread[NR_CPUS];
61 struct crypto_shash *siw_crypto_shash;
62 
63 static int siw_device_register(struct siw_device *sdev, const char *name)
64 {
65 	struct ib_device *base_dev = &sdev->base_dev;
66 	static int dev_id = 1;
67 	int rv;
68 
69 	rv = ib_register_device(base_dev, name);
70 	if (rv) {
71 		pr_warn("siw: device registration error %d\n", rv);
72 		return rv;
73 	}
74 	sdev->vendor_part_id = dev_id++;
75 
76 	siw_dbg(base_dev, "HWaddr=%pM\n", sdev->netdev->dev_addr);
77 
78 	return 0;
79 }
80 
81 static void siw_device_cleanup(struct ib_device *base_dev)
82 {
83 	struct siw_device *sdev = to_siw_dev(base_dev);
84 
85 	xa_destroy(&sdev->qp_xa);
86 	xa_destroy(&sdev->mem_xa);
87 }
88 
89 static int siw_create_tx_threads(void)
90 {
91 	int cpu, assigned = 0;
92 
93 	for_each_online_cpu(cpu) {
94 		/* Skip HT cores */
95 		if (cpu % cpumask_weight(topology_sibling_cpumask(cpu)))
96 			continue;
97 
98 		siw_tx_thread[cpu] =
99 			kthread_create(siw_run_sq, (unsigned long *)(long)cpu,
100 				       "siw_tx/%d", cpu);
101 		if (IS_ERR(siw_tx_thread[cpu])) {
102 			siw_tx_thread[cpu] = NULL;
103 			continue;
104 		}
105 		kthread_bind(siw_tx_thread[cpu], cpu);
106 
107 		wake_up_process(siw_tx_thread[cpu]);
108 		assigned++;
109 	}
110 	return assigned;
111 }
112 
113 static int siw_dev_qualified(struct net_device *netdev)
114 {
115 	/*
116 	 * Additional hardware support can be added here
117 	 * (e.g. ARPHRD_FDDI, ARPHRD_ATM, ...) - see
118 	 * <linux/if_arp.h> for type identifiers.
119 	 */
120 	if (netdev->type == ARPHRD_ETHER || netdev->type == ARPHRD_IEEE802 ||
121 	    (netdev->type == ARPHRD_LOOPBACK && loopback_enabled))
122 		return 1;
123 
124 	return 0;
125 }
126 
127 static DEFINE_PER_CPU(atomic_t, siw_use_cnt);
128 
129 static struct {
130 	struct cpumask **tx_valid_cpus;
131 	int num_nodes;
132 } siw_cpu_info;
133 
134 static int siw_init_cpulist(void)
135 {
136 	int i, num_nodes = num_possible_nodes();
137 
138 	memset(siw_tx_thread, 0, sizeof(siw_tx_thread));
139 
140 	siw_cpu_info.num_nodes = num_nodes;
141 
142 	siw_cpu_info.tx_valid_cpus =
143 		kcalloc(num_nodes, sizeof(struct cpumask *), GFP_KERNEL);
144 	if (!siw_cpu_info.tx_valid_cpus) {
145 		siw_cpu_info.num_nodes = 0;
146 		return -ENOMEM;
147 	}
148 	for (i = 0; i < siw_cpu_info.num_nodes; i++) {
149 		siw_cpu_info.tx_valid_cpus[i] =
150 			kzalloc(sizeof(struct cpumask), GFP_KERNEL);
151 		if (!siw_cpu_info.tx_valid_cpus[i])
152 			goto out_err;
153 
154 		cpumask_clear(siw_cpu_info.tx_valid_cpus[i]);
155 	}
156 	for_each_possible_cpu(i)
157 		cpumask_set_cpu(i, siw_cpu_info.tx_valid_cpus[cpu_to_node(i)]);
158 
159 	return 0;
160 
161 out_err:
162 	siw_cpu_info.num_nodes = 0;
163 	while (i) {
164 		kfree(siw_cpu_info.tx_valid_cpus[i]);
165 		siw_cpu_info.tx_valid_cpus[i--] = NULL;
166 	}
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->ib_qp;
249 	}
250 	return NULL;
251 }
252 
253 static void siw_verbs_sq_flush(struct ib_qp *base_qp)
254 {
255 	struct siw_qp *qp = to_siw_qp(base_qp);
256 
257 	down_write(&qp->state_lock);
258 	siw_sq_flush(qp);
259 	up_write(&qp->state_lock);
260 }
261 
262 static void siw_verbs_rq_flush(struct ib_qp *base_qp)
263 {
264 	struct siw_qp *qp = to_siw_qp(base_qp);
265 
266 	down_write(&qp->state_lock);
267 	siw_rq_flush(qp);
268 	up_write(&qp->state_lock);
269 }
270 
271 static const struct ib_device_ops siw_device_ops = {
272 	.owner = THIS_MODULE,
273 	.uverbs_abi_ver = SIW_ABI_VERSION,
274 	.driver_id = RDMA_DRIVER_SIW,
275 
276 	.alloc_mr = siw_alloc_mr,
277 	.alloc_pd = siw_alloc_pd,
278 	.alloc_ucontext = siw_alloc_ucontext,
279 	.create_cq = siw_create_cq,
280 	.create_qp = siw_create_qp,
281 	.create_srq = siw_create_srq,
282 	.dealloc_driver = siw_device_cleanup,
283 	.dealloc_pd = siw_dealloc_pd,
284 	.dealloc_ucontext = siw_dealloc_ucontext,
285 	.dereg_mr = siw_dereg_mr,
286 	.destroy_cq = siw_destroy_cq,
287 	.destroy_qp = siw_destroy_qp,
288 	.destroy_srq = siw_destroy_srq,
289 	.drain_rq = siw_verbs_rq_flush,
290 	.drain_sq = siw_verbs_sq_flush,
291 	.get_dma_mr = siw_get_dma_mr,
292 	.get_port_immutable = siw_get_port_immutable,
293 	.iw_accept = siw_accept,
294 	.iw_add_ref = siw_qp_get_ref,
295 	.iw_connect = siw_connect,
296 	.iw_create_listen = siw_create_listen,
297 	.iw_destroy_listen = siw_destroy_listen,
298 	.iw_get_qp = siw_get_base_qp,
299 	.iw_reject = siw_reject,
300 	.iw_rem_ref = siw_qp_put_ref,
301 	.map_mr_sg = siw_map_mr_sg,
302 	.mmap = siw_mmap,
303 	.modify_qp = siw_verbs_modify_qp,
304 	.modify_srq = siw_modify_srq,
305 	.poll_cq = siw_poll_cq,
306 	.post_recv = siw_post_receive,
307 	.post_send = siw_post_send,
308 	.post_srq_recv = siw_post_srq_recv,
309 	.query_device = siw_query_device,
310 	.query_gid = siw_query_gid,
311 	.query_pkey = siw_query_pkey,
312 	.query_port = siw_query_port,
313 	.query_qp = siw_query_qp,
314 	.query_srq = siw_query_srq,
315 	.req_notify_cq = siw_req_notify_cq,
316 	.reg_user_mr = siw_reg_user_mr,
317 
318 	INIT_RDMA_OBJ_SIZE(ib_cq, siw_cq, base_cq),
319 	INIT_RDMA_OBJ_SIZE(ib_pd, siw_pd, base_pd),
320 	INIT_RDMA_OBJ_SIZE(ib_srq, siw_srq, base_srq),
321 	INIT_RDMA_OBJ_SIZE(ib_ucontext, siw_ucontext, base_ucontext),
322 };
323 
324 static struct siw_device *siw_device_create(struct net_device *netdev)
325 {
326 	struct siw_device *sdev = NULL;
327 	struct ib_device *base_dev;
328 	struct device *parent = netdev->dev.parent;
329 	int rv;
330 
331 	if (!parent) {
332 		/*
333 		 * The loopback device has no parent device,
334 		 * so it appears as a top-level device. To support
335 		 * loopback device connectivity, take this device
336 		 * as the parent device. Skip all other devices
337 		 * w/o parent device.
338 		 */
339 		if (netdev->type != ARPHRD_LOOPBACK) {
340 			pr_warn("siw: device %s error: no parent device\n",
341 				netdev->name);
342 			return NULL;
343 		}
344 		parent = &netdev->dev;
345 	}
346 	sdev = ib_alloc_device(siw_device, base_dev);
347 	if (!sdev)
348 		return NULL;
349 
350 	base_dev = &sdev->base_dev;
351 
352 	sdev->netdev = netdev;
353 
354 	if (netdev->type != ARPHRD_LOOPBACK) {
355 		memcpy(&base_dev->node_guid, netdev->dev_addr, 6);
356 	} else {
357 		/*
358 		 * The loopback device does not have a HW address,
359 		 * but connection mangagement lib expects gid != 0
360 		 */
361 		size_t gidlen = min_t(size_t, strlen(base_dev->name), 6);
362 
363 		memcpy(&base_dev->node_guid, base_dev->name, gidlen);
364 	}
365 	base_dev->uverbs_cmd_mask =
366 		(1ull << IB_USER_VERBS_CMD_QUERY_DEVICE) |
367 		(1ull << IB_USER_VERBS_CMD_QUERY_PORT) |
368 		(1ull << IB_USER_VERBS_CMD_GET_CONTEXT) |
369 		(1ull << IB_USER_VERBS_CMD_ALLOC_PD) |
370 		(1ull << IB_USER_VERBS_CMD_DEALLOC_PD) |
371 		(1ull << IB_USER_VERBS_CMD_REG_MR) |
372 		(1ull << IB_USER_VERBS_CMD_DEREG_MR) |
373 		(1ull << IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL) |
374 		(1ull << IB_USER_VERBS_CMD_CREATE_CQ) |
375 		(1ull << IB_USER_VERBS_CMD_POLL_CQ) |
376 		(1ull << IB_USER_VERBS_CMD_REQ_NOTIFY_CQ) |
377 		(1ull << IB_USER_VERBS_CMD_DESTROY_CQ) |
378 		(1ull << IB_USER_VERBS_CMD_CREATE_QP) |
379 		(1ull << IB_USER_VERBS_CMD_QUERY_QP) |
380 		(1ull << IB_USER_VERBS_CMD_MODIFY_QP) |
381 		(1ull << IB_USER_VERBS_CMD_DESTROY_QP) |
382 		(1ull << IB_USER_VERBS_CMD_POST_SEND) |
383 		(1ull << IB_USER_VERBS_CMD_POST_RECV) |
384 		(1ull << IB_USER_VERBS_CMD_CREATE_SRQ) |
385 		(1ull << IB_USER_VERBS_CMD_POST_SRQ_RECV) |
386 		(1ull << IB_USER_VERBS_CMD_MODIFY_SRQ) |
387 		(1ull << IB_USER_VERBS_CMD_QUERY_SRQ) |
388 		(1ull << IB_USER_VERBS_CMD_DESTROY_SRQ);
389 
390 	base_dev->node_type = RDMA_NODE_RNIC;
391 	memcpy(base_dev->node_desc, SIW_NODE_DESC_COMMON,
392 	       sizeof(SIW_NODE_DESC_COMMON));
393 
394 	/*
395 	 * Current model (one-to-one device association):
396 	 * One Softiwarp device per net_device or, equivalently,
397 	 * per physical port.
398 	 */
399 	base_dev->phys_port_cnt = 1;
400 	base_dev->dev.parent = parent;
401 	base_dev->dev.dma_ops = &dma_virt_ops;
402 	base_dev->num_comp_vectors = num_possible_cpus();
403 
404 	ib_set_device_ops(base_dev, &siw_device_ops);
405 	rv = ib_device_set_netdev(base_dev, netdev, 1);
406 	if (rv)
407 		goto error;
408 
409 	memcpy(base_dev->iw_ifname, netdev->name,
410 	       sizeof(base_dev->iw_ifname));
411 
412 	/* Disable TCP port mapping */
413 	base_dev->iw_driver_flags = IW_F_NO_PORT_MAP,
414 
415 	sdev->attrs.max_qp = SIW_MAX_QP;
416 	sdev->attrs.max_qp_wr = SIW_MAX_QP_WR;
417 	sdev->attrs.max_ord = SIW_MAX_ORD_QP;
418 	sdev->attrs.max_ird = SIW_MAX_IRD_QP;
419 	sdev->attrs.max_sge = SIW_MAX_SGE;
420 	sdev->attrs.max_sge_rd = SIW_MAX_SGE_RD;
421 	sdev->attrs.max_cq = SIW_MAX_CQ;
422 	sdev->attrs.max_cqe = SIW_MAX_CQE;
423 	sdev->attrs.max_mr = SIW_MAX_MR;
424 	sdev->attrs.max_pd = SIW_MAX_PD;
425 	sdev->attrs.max_mw = SIW_MAX_MW;
426 	sdev->attrs.max_fmr = SIW_MAX_FMR;
427 	sdev->attrs.max_srq = SIW_MAX_SRQ;
428 	sdev->attrs.max_srq_wr = SIW_MAX_SRQ_WR;
429 	sdev->attrs.max_srq_sge = SIW_MAX_SGE;
430 
431 	xa_init_flags(&sdev->qp_xa, XA_FLAGS_ALLOC1);
432 	xa_init_flags(&sdev->mem_xa, XA_FLAGS_ALLOC1);
433 
434 	INIT_LIST_HEAD(&sdev->cep_list);
435 	INIT_LIST_HEAD(&sdev->qp_list);
436 
437 	atomic_set(&sdev->num_ctx, 0);
438 	atomic_set(&sdev->num_srq, 0);
439 	atomic_set(&sdev->num_qp, 0);
440 	atomic_set(&sdev->num_cq, 0);
441 	atomic_set(&sdev->num_mr, 0);
442 	atomic_set(&sdev->num_pd, 0);
443 
444 	sdev->numa_node = dev_to_node(parent);
445 	spin_lock_init(&sdev->lock);
446 
447 	return sdev;
448 error:
449 	ib_dealloc_device(base_dev);
450 
451 	return NULL;
452 }
453 
454 /*
455  * Network link becomes unavailable. Mark all
456  * affected QP's accordingly.
457  */
458 static void siw_netdev_down(struct work_struct *work)
459 {
460 	struct siw_device *sdev =
461 		container_of(work, struct siw_device, netdev_down);
462 
463 	struct siw_qp_attrs qp_attrs;
464 	struct list_head *pos, *tmp;
465 
466 	memset(&qp_attrs, 0, sizeof(qp_attrs));
467 	qp_attrs.state = SIW_QP_STATE_ERROR;
468 
469 	list_for_each_safe(pos, tmp, &sdev->qp_list) {
470 		struct siw_qp *qp = list_entry(pos, struct siw_qp, devq);
471 
472 		down_write(&qp->state_lock);
473 		WARN_ON(siw_qp_modify(qp, &qp_attrs, SIW_QP_ATTR_STATE));
474 		up_write(&qp->state_lock);
475 	}
476 	ib_device_put(&sdev->base_dev);
477 }
478 
479 static void siw_device_goes_down(struct siw_device *sdev)
480 {
481 	if (ib_device_try_get(&sdev->base_dev)) {
482 		INIT_WORK(&sdev->netdev_down, siw_netdev_down);
483 		schedule_work(&sdev->netdev_down);
484 	}
485 }
486 
487 static int siw_netdev_event(struct notifier_block *nb, unsigned long event,
488 			    void *arg)
489 {
490 	struct net_device *netdev = netdev_notifier_info_to_dev(arg);
491 	struct ib_device *base_dev;
492 	struct siw_device *sdev;
493 
494 	dev_dbg(&netdev->dev, "siw: event %lu\n", event);
495 
496 	if (dev_net(netdev) != &init_net)
497 		return NOTIFY_OK;
498 
499 	base_dev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_SIW);
500 	if (!base_dev)
501 		return NOTIFY_OK;
502 
503 	sdev = to_siw_dev(base_dev);
504 
505 	switch (event) {
506 	case NETDEV_UP:
507 		sdev->state = IB_PORT_ACTIVE;
508 		siw_port_event(sdev, 1, IB_EVENT_PORT_ACTIVE);
509 		break;
510 
511 	case NETDEV_GOING_DOWN:
512 		siw_device_goes_down(sdev);
513 		break;
514 
515 	case NETDEV_DOWN:
516 		sdev->state = IB_PORT_DOWN;
517 		siw_port_event(sdev, 1, IB_EVENT_PORT_ERR);
518 		break;
519 
520 	case NETDEV_REGISTER:
521 		/*
522 		 * Device registration now handled only by
523 		 * rdma netlink commands. So it shall be impossible
524 		 * to end up here with a valid siw device.
525 		 */
526 		siw_dbg(base_dev, "unexpected NETDEV_REGISTER event\n");
527 		break;
528 
529 	case NETDEV_UNREGISTER:
530 		ib_unregister_device_queued(&sdev->base_dev);
531 		break;
532 
533 	case NETDEV_CHANGEADDR:
534 		siw_port_event(sdev, 1, IB_EVENT_LID_CHANGE);
535 		break;
536 	/*
537 	 * Todo: Below netdev events are currently not handled.
538 	 */
539 	case NETDEV_CHANGEMTU:
540 	case NETDEV_CHANGE:
541 		break;
542 
543 	default:
544 		break;
545 	}
546 	ib_device_put(&sdev->base_dev);
547 
548 	return NOTIFY_OK;
549 }
550 
551 static struct notifier_block siw_netdev_nb = {
552 	.notifier_call = siw_netdev_event,
553 };
554 
555 static int siw_newlink(const char *basedev_name, struct net_device *netdev)
556 {
557 	struct ib_device *base_dev;
558 	struct siw_device *sdev = NULL;
559 	int rv = -ENOMEM;
560 
561 	if (!siw_dev_qualified(netdev))
562 		return -EINVAL;
563 
564 	base_dev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_SIW);
565 	if (base_dev) {
566 		ib_device_put(base_dev);
567 		return -EEXIST;
568 	}
569 	sdev = siw_device_create(netdev);
570 	if (sdev) {
571 		dev_dbg(&netdev->dev, "siw: new device\n");
572 
573 		if (netif_running(netdev) && netif_carrier_ok(netdev))
574 			sdev->state = IB_PORT_ACTIVE;
575 		else
576 			sdev->state = IB_PORT_DOWN;
577 
578 		rv = siw_device_register(sdev, basedev_name);
579 		if (rv)
580 			ib_dealloc_device(&sdev->base_dev);
581 	}
582 	return rv;
583 }
584 
585 static struct rdma_link_ops siw_link_ops = {
586 	.type = "siw",
587 	.newlink = siw_newlink,
588 };
589 
590 /*
591  * siw_init_module - Initialize Softiwarp module and register with netdev
592  *                   subsystem.
593  */
594 static __init int siw_init_module(void)
595 {
596 	int rv;
597 	int nr_cpu;
598 
599 	if (SENDPAGE_THRESH < SIW_MAX_INLINE) {
600 		pr_info("siw: sendpage threshold too small: %u\n",
601 			(int)SENDPAGE_THRESH);
602 		rv = -EINVAL;
603 		goto out_error;
604 	}
605 	rv = siw_init_cpulist();
606 	if (rv)
607 		goto out_error;
608 
609 	rv = siw_cm_init();
610 	if (rv)
611 		goto out_error;
612 
613 	if (!siw_create_tx_threads()) {
614 		pr_info("siw: Could not start any TX thread\n");
615 		rv = -ENOMEM;
616 		goto out_error;
617 	}
618 	/*
619 	 * Locate CRC32 algorithm. If unsuccessful, fail
620 	 * loading siw only, if CRC is required.
621 	 */
622 	siw_crypto_shash = crypto_alloc_shash("crc32c", 0, 0);
623 	if (IS_ERR(siw_crypto_shash)) {
624 		pr_info("siw: Loading CRC32c failed: %ld\n",
625 			PTR_ERR(siw_crypto_shash));
626 		siw_crypto_shash = NULL;
627 		if (mpa_crc_required) {
628 			rv = -EOPNOTSUPP;
629 			goto out_error;
630 		}
631 	}
632 	rv = register_netdevice_notifier(&siw_netdev_nb);
633 	if (rv)
634 		goto out_error;
635 
636 	rdma_link_register(&siw_link_ops);
637 
638 	pr_info("SoftiWARP attached\n");
639 	return 0;
640 
641 out_error:
642 	for (nr_cpu = 0; nr_cpu < nr_cpu_ids; nr_cpu++) {
643 		if (siw_tx_thread[nr_cpu]) {
644 			siw_stop_tx_thread(nr_cpu);
645 			siw_tx_thread[nr_cpu] = NULL;
646 		}
647 	}
648 	if (siw_crypto_shash)
649 		crypto_free_shash(siw_crypto_shash);
650 
651 	pr_info("SoftIWARP attach failed. Error: %d\n", rv);
652 
653 	siw_cm_exit();
654 	siw_destroy_cpulist();
655 
656 	return rv;
657 }
658 
659 static void __exit siw_exit_module(void)
660 {
661 	int cpu;
662 
663 	for_each_possible_cpu(cpu) {
664 		if (siw_tx_thread[cpu]) {
665 			siw_stop_tx_thread(cpu);
666 			siw_tx_thread[cpu] = NULL;
667 		}
668 	}
669 	unregister_netdevice_notifier(&siw_netdev_nb);
670 	rdma_link_unregister(&siw_link_ops);
671 	ib_unregister_driver(RDMA_DRIVER_SIW);
672 
673 	siw_cm_exit();
674 
675 	siw_destroy_cpulist();
676 
677 	if (siw_crypto_shash)
678 		crypto_free_shash(siw_crypto_shash);
679 
680 	pr_info("SoftiWARP detached\n");
681 }
682 
683 module_init(siw_init_module);
684 module_exit(siw_exit_module);
685 
686 MODULE_ALIAS_RDMA_LINK("siw");
687