xref: /linux/net/smc/af_smc.c (revision a4ff64edf9edc8f05e2183610dc8306d3279c6ac)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
6  *  applies to SOCK_STREAM sockets only
7  *  offers an alternative communication option for TCP-protocol sockets
8  *  applicable with RoCE-cards only
9  *
10  *  Initial restrictions:
11  *    - support for alternate links postponed
12  *
13  *  Copyright IBM Corp. 2016, 2018
14  *
15  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
16  *              based on prototype from Frank Blaschka
17  */
18 
19 #define KMSG_COMPONENT "smc"
20 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
21 
22 #include <linux/module.h>
23 #include <linux/socket.h>
24 #include <linux/workqueue.h>
25 #include <linux/in.h>
26 #include <linux/sched/signal.h>
27 #include <linux/if_vlan.h>
28 #include <linux/rcupdate_wait.h>
29 #include <linux/ctype.h>
30 #include <linux/splice.h>
31 
32 #include <net/sock.h>
33 #include <net/tcp.h>
34 #include <net/smc.h>
35 #include <asm/ioctls.h>
36 
37 #include <net/net_namespace.h>
38 #include <net/netns/generic.h>
39 #include "smc_netns.h"
40 
41 #include "smc.h"
42 #include "smc_clc.h"
43 #include "smc_llc.h"
44 #include "smc_cdc.h"
45 #include "smc_core.h"
46 #include "smc_ib.h"
47 #include "smc_ism.h"
48 #include "smc_pnet.h"
49 #include "smc_netlink.h"
50 #include "smc_tx.h"
51 #include "smc_rx.h"
52 #include "smc_close.h"
53 #include "smc_stats.h"
54 #include "smc_tracepoint.h"
55 #include "smc_sysctl.h"
56 
57 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
58 						 * creation on server
59 						 */
60 static DEFINE_MUTEX(smc_client_lgr_pending);	/* serialize link group
61 						 * creation on client
62 						 */
63 
64 static struct workqueue_struct	*smc_tcp_ls_wq;	/* wq for tcp listen work */
65 struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
66 struct workqueue_struct	*smc_close_wq;	/* wq for close work */
67 
68 static void smc_tcp_listen_work(struct work_struct *);
69 static void smc_connect_work(struct work_struct *);
70 
71 int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb)
72 {
73 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
74 	void *hdr;
75 
76 	if (cb_ctx->pos[0])
77 		goto out;
78 
79 	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
80 			  &smc_gen_nl_family, NLM_F_MULTI,
81 			  SMC_NETLINK_DUMP_HS_LIMITATION);
82 	if (!hdr)
83 		return -ENOMEM;
84 
85 	if (nla_put_u8(skb, SMC_NLA_HS_LIMITATION_ENABLED,
86 		       sock_net(skb->sk)->smc.limit_smc_hs))
87 		goto err;
88 
89 	genlmsg_end(skb, hdr);
90 	cb_ctx->pos[0] = 1;
91 out:
92 	return skb->len;
93 err:
94 	genlmsg_cancel(skb, hdr);
95 	return -EMSGSIZE;
96 }
97 
98 int smc_nl_enable_hs_limitation(struct sk_buff *skb, struct genl_info *info)
99 {
100 	sock_net(skb->sk)->smc.limit_smc_hs = true;
101 	return 0;
102 }
103 
104 int smc_nl_disable_hs_limitation(struct sk_buff *skb, struct genl_info *info)
105 {
106 	sock_net(skb->sk)->smc.limit_smc_hs = false;
107 	return 0;
108 }
109 
110 static void smc_set_keepalive(struct sock *sk, int val)
111 {
112 	struct smc_sock *smc = smc_sk(sk);
113 
114 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
115 }
116 
117 static struct sock *smc_tcp_syn_recv_sock(const struct sock *sk,
118 					  struct sk_buff *skb,
119 					  struct request_sock *req,
120 					  struct dst_entry *dst,
121 					  struct request_sock *req_unhash,
122 					  bool *own_req)
123 {
124 	struct smc_sock *smc;
125 	struct sock *child;
126 
127 	smc = smc_clcsock_user_data(sk);
128 
129 	if (READ_ONCE(sk->sk_ack_backlog) + atomic_read(&smc->queued_smc_hs) >
130 				sk->sk_max_ack_backlog)
131 		goto drop;
132 
133 	if (sk_acceptq_is_full(&smc->sk)) {
134 		NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
135 		goto drop;
136 	}
137 
138 	/* passthrough to original syn recv sock fct */
139 	child = smc->ori_af_ops->syn_recv_sock(sk, skb, req, dst, req_unhash,
140 					       own_req);
141 	/* child must not inherit smc or its ops */
142 	if (child) {
143 		rcu_assign_sk_user_data(child, NULL);
144 
145 		/* v4-mapped sockets don't inherit parent ops. Don't restore. */
146 		if (inet_csk(child)->icsk_af_ops == inet_csk(sk)->icsk_af_ops)
147 			inet_csk(child)->icsk_af_ops = smc->ori_af_ops;
148 	}
149 	return child;
150 
151 drop:
152 	dst_release(dst);
153 	tcp_listendrop(sk);
154 	return NULL;
155 }
156 
157 static bool smc_hs_congested(const struct sock *sk)
158 {
159 	const struct smc_sock *smc;
160 
161 	smc = smc_clcsock_user_data(sk);
162 
163 	if (!smc)
164 		return true;
165 
166 	if (workqueue_congested(WORK_CPU_UNBOUND, smc_hs_wq))
167 		return true;
168 
169 	return false;
170 }
171 
172 static struct smc_hashinfo smc_v4_hashinfo = {
173 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
174 };
175 
176 static struct smc_hashinfo smc_v6_hashinfo = {
177 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
178 };
179 
180 int smc_hash_sk(struct sock *sk)
181 {
182 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
183 	struct hlist_head *head;
184 
185 	head = &h->ht;
186 
187 	write_lock_bh(&h->lock);
188 	sk_add_node(sk, head);
189 	write_unlock_bh(&h->lock);
190 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
191 
192 	return 0;
193 }
194 EXPORT_SYMBOL_GPL(smc_hash_sk);
195 
196 void smc_unhash_sk(struct sock *sk)
197 {
198 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
199 
200 	write_lock_bh(&h->lock);
201 	if (sk_del_node_init(sk))
202 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
203 	write_unlock_bh(&h->lock);
204 }
205 EXPORT_SYMBOL_GPL(smc_unhash_sk);
206 
207 /* This will be called before user really release sock_lock. So do the
208  * work which we didn't do because of user hold the sock_lock in the
209  * BH context
210  */
211 static void smc_release_cb(struct sock *sk)
212 {
213 	struct smc_sock *smc = smc_sk(sk);
214 
215 	if (smc->conn.tx_in_release_sock) {
216 		smc_tx_pending(&smc->conn);
217 		smc->conn.tx_in_release_sock = false;
218 	}
219 }
220 
221 struct proto smc_proto = {
222 	.name		= "SMC",
223 	.owner		= THIS_MODULE,
224 	.keepalive	= smc_set_keepalive,
225 	.hash		= smc_hash_sk,
226 	.unhash		= smc_unhash_sk,
227 	.release_cb	= smc_release_cb,
228 	.obj_size	= sizeof(struct smc_sock),
229 	.h.smc_hash	= &smc_v4_hashinfo,
230 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
231 };
232 EXPORT_SYMBOL_GPL(smc_proto);
233 
234 struct proto smc_proto6 = {
235 	.name		= "SMC6",
236 	.owner		= THIS_MODULE,
237 	.keepalive	= smc_set_keepalive,
238 	.hash		= smc_hash_sk,
239 	.unhash		= smc_unhash_sk,
240 	.release_cb	= smc_release_cb,
241 	.obj_size	= sizeof(struct smc_sock),
242 	.h.smc_hash	= &smc_v6_hashinfo,
243 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
244 };
245 EXPORT_SYMBOL_GPL(smc_proto6);
246 
247 static void smc_fback_restore_callbacks(struct smc_sock *smc)
248 {
249 	struct sock *clcsk = smc->clcsock->sk;
250 
251 	write_lock_bh(&clcsk->sk_callback_lock);
252 	clcsk->sk_user_data = NULL;
253 
254 	smc_clcsock_restore_cb(&clcsk->sk_state_change, &smc->clcsk_state_change);
255 	smc_clcsock_restore_cb(&clcsk->sk_data_ready, &smc->clcsk_data_ready);
256 	smc_clcsock_restore_cb(&clcsk->sk_write_space, &smc->clcsk_write_space);
257 	smc_clcsock_restore_cb(&clcsk->sk_error_report, &smc->clcsk_error_report);
258 
259 	write_unlock_bh(&clcsk->sk_callback_lock);
260 }
261 
262 static void smc_restore_fallback_changes(struct smc_sock *smc)
263 {
264 	if (smc->clcsock->file) { /* non-accepted sockets have no file yet */
265 		smc->clcsock->file->private_data = smc->sk.sk_socket;
266 		smc->clcsock->file = NULL;
267 		smc_fback_restore_callbacks(smc);
268 	}
269 }
270 
271 static int __smc_release(struct smc_sock *smc)
272 {
273 	struct sock *sk = &smc->sk;
274 	int rc = 0;
275 
276 	if (!smc->use_fallback) {
277 		rc = smc_close_active(smc);
278 		smc_sock_set_flag(sk, SOCK_DEAD);
279 		sk->sk_shutdown |= SHUTDOWN_MASK;
280 	} else {
281 		if (sk->sk_state != SMC_CLOSED) {
282 			if (sk->sk_state != SMC_LISTEN &&
283 			    sk->sk_state != SMC_INIT)
284 				sock_put(sk); /* passive closing */
285 			if (sk->sk_state == SMC_LISTEN) {
286 				/* wake up clcsock accept */
287 				rc = kernel_sock_shutdown(smc->clcsock,
288 							  SHUT_RDWR);
289 			}
290 			sk->sk_state = SMC_CLOSED;
291 			sk->sk_state_change(sk);
292 		}
293 		smc_restore_fallback_changes(smc);
294 	}
295 
296 	sk->sk_prot->unhash(sk);
297 
298 	if (sk->sk_state == SMC_CLOSED) {
299 		if (smc->clcsock) {
300 			release_sock(sk);
301 			smc_clcsock_release(smc);
302 			lock_sock(sk);
303 		}
304 		if (!smc->use_fallback)
305 			smc_conn_free(&smc->conn);
306 	}
307 
308 	return rc;
309 }
310 
311 static int smc_release(struct socket *sock)
312 {
313 	struct sock *sk = sock->sk;
314 	struct smc_sock *smc;
315 	int old_state, rc = 0;
316 
317 	if (!sk)
318 		goto out;
319 
320 	sock_hold(sk); /* sock_put below */
321 	smc = smc_sk(sk);
322 
323 	old_state = sk->sk_state;
324 
325 	/* cleanup for a dangling non-blocking connect */
326 	if (smc->connect_nonblock && old_state == SMC_INIT)
327 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
328 
329 	if (cancel_work_sync(&smc->connect_work))
330 		sock_put(&smc->sk); /* sock_hold in smc_connect for passive closing */
331 
332 	if (sk->sk_state == SMC_LISTEN)
333 		/* smc_close_non_accepted() is called and acquires
334 		 * sock lock for child sockets again
335 		 */
336 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
337 	else
338 		lock_sock(sk);
339 
340 	if (old_state == SMC_INIT && sk->sk_state == SMC_ACTIVE &&
341 	    !smc->use_fallback)
342 		smc_close_active_abort(smc);
343 
344 	rc = __smc_release(smc);
345 
346 	/* detach socket */
347 	sock_orphan(sk);
348 	sock->sk = NULL;
349 	release_sock(sk);
350 
351 	sock_put(sk); /* sock_hold above */
352 	sock_put(sk); /* final sock_put */
353 out:
354 	return rc;
355 }
356 
357 static void smc_destruct(struct sock *sk)
358 {
359 	if (sk->sk_state != SMC_CLOSED)
360 		return;
361 	if (!sock_flag(sk, SOCK_DEAD))
362 		return;
363 }
364 
365 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
366 				   int protocol)
367 {
368 	struct smc_sock *smc;
369 	struct proto *prot;
370 	struct sock *sk;
371 
372 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
373 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
374 	if (!sk)
375 		return NULL;
376 
377 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
378 	sk->sk_state = SMC_INIT;
379 	sk->sk_destruct = smc_destruct;
380 	sk->sk_protocol = protocol;
381 	WRITE_ONCE(sk->sk_sndbuf, 2 * READ_ONCE(net->smc.sysctl_wmem));
382 	WRITE_ONCE(sk->sk_rcvbuf, 2 * READ_ONCE(net->smc.sysctl_rmem));
383 	smc = smc_sk(sk);
384 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
385 	INIT_WORK(&smc->connect_work, smc_connect_work);
386 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
387 	INIT_LIST_HEAD(&smc->accept_q);
388 	spin_lock_init(&smc->accept_q_lock);
389 	spin_lock_init(&smc->conn.send_lock);
390 	sk->sk_prot->hash(sk);
391 	mutex_init(&smc->clcsock_release_lock);
392 	smc_init_saved_callbacks(smc);
393 
394 	return sk;
395 }
396 
397 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
398 		    int addr_len)
399 {
400 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
401 	struct sock *sk = sock->sk;
402 	struct smc_sock *smc;
403 	int rc;
404 
405 	smc = smc_sk(sk);
406 
407 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
408 	rc = -EINVAL;
409 	if (addr_len < sizeof(struct sockaddr_in))
410 		goto out;
411 
412 	rc = -EAFNOSUPPORT;
413 	if (addr->sin_family != AF_INET &&
414 	    addr->sin_family != AF_INET6 &&
415 	    addr->sin_family != AF_UNSPEC)
416 		goto out;
417 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
418 	if (addr->sin_family == AF_UNSPEC &&
419 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
420 		goto out;
421 
422 	lock_sock(sk);
423 
424 	/* Check if socket is already active */
425 	rc = -EINVAL;
426 	if (sk->sk_state != SMC_INIT || smc->connect_nonblock)
427 		goto out_rel;
428 
429 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
430 	smc->clcsock->sk->sk_reuseport = sk->sk_reuseport;
431 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
432 
433 out_rel:
434 	release_sock(sk);
435 out:
436 	return rc;
437 }
438 
439 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
440  * clc socket (since smc is not called for these options from net/core)
441  */
442 
443 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
444 			     (1UL << SOCK_KEEPOPEN) | \
445 			     (1UL << SOCK_LINGER) | \
446 			     (1UL << SOCK_BROADCAST) | \
447 			     (1UL << SOCK_TIMESTAMP) | \
448 			     (1UL << SOCK_DBG) | \
449 			     (1UL << SOCK_RCVTSTAMP) | \
450 			     (1UL << SOCK_RCVTSTAMPNS) | \
451 			     (1UL << SOCK_LOCALROUTE) | \
452 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
453 			     (1UL << SOCK_RXQ_OVFL) | \
454 			     (1UL << SOCK_WIFI_STATUS) | \
455 			     (1UL << SOCK_NOFCS) | \
456 			     (1UL << SOCK_FILTER_LOCKED) | \
457 			     (1UL << SOCK_TSTAMP_NEW))
458 
459 /* if set, use value set by setsockopt() - else use IPv4 or SMC sysctl value */
460 static void smc_adjust_sock_bufsizes(struct sock *nsk, struct sock *osk,
461 				     unsigned long mask)
462 {
463 	struct net *nnet = sock_net(nsk);
464 
465 	nsk->sk_userlocks = osk->sk_userlocks;
466 	if (osk->sk_userlocks & SOCK_SNDBUF_LOCK) {
467 		nsk->sk_sndbuf = osk->sk_sndbuf;
468 	} else {
469 		if (mask == SK_FLAGS_SMC_TO_CLC)
470 			WRITE_ONCE(nsk->sk_sndbuf,
471 				   READ_ONCE(nnet->ipv4.sysctl_tcp_wmem[1]));
472 		else
473 			WRITE_ONCE(nsk->sk_sndbuf,
474 				   2 * READ_ONCE(nnet->smc.sysctl_wmem));
475 	}
476 	if (osk->sk_userlocks & SOCK_RCVBUF_LOCK) {
477 		nsk->sk_rcvbuf = osk->sk_rcvbuf;
478 	} else {
479 		if (mask == SK_FLAGS_SMC_TO_CLC)
480 			WRITE_ONCE(nsk->sk_rcvbuf,
481 				   READ_ONCE(nnet->ipv4.sysctl_tcp_rmem[1]));
482 		else
483 			WRITE_ONCE(nsk->sk_rcvbuf,
484 				   2 * READ_ONCE(nnet->smc.sysctl_rmem));
485 	}
486 }
487 
488 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
489 				   unsigned long mask)
490 {
491 	/* options we don't get control via setsockopt for */
492 	nsk->sk_type = osk->sk_type;
493 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
494 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
495 	nsk->sk_mark = READ_ONCE(osk->sk_mark);
496 	nsk->sk_priority = READ_ONCE(osk->sk_priority);
497 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
498 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
499 	nsk->sk_err = osk->sk_err;
500 
501 	nsk->sk_flags &= ~mask;
502 	nsk->sk_flags |= osk->sk_flags & mask;
503 
504 	smc_adjust_sock_bufsizes(nsk, osk, mask);
505 }
506 
507 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
508 {
509 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
510 }
511 
512 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
513 			     (1UL << SOCK_KEEPOPEN) | \
514 			     (1UL << SOCK_LINGER) | \
515 			     (1UL << SOCK_DBG))
516 /* copy only settings and flags relevant for smc from clc to smc socket */
517 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
518 {
519 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
520 }
521 
522 /* register the new vzalloced sndbuf on all links */
523 static int smcr_lgr_reg_sndbufs(struct smc_link *link,
524 				struct smc_buf_desc *snd_desc)
525 {
526 	struct smc_link_group *lgr = link->lgr;
527 	int i, rc = 0;
528 
529 	if (!snd_desc->is_vm)
530 		return -EINVAL;
531 
532 	/* protect against parallel smcr_link_reg_buf() */
533 	down_write(&lgr->llc_conf_mutex);
534 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
535 		if (!smc_link_active(&lgr->lnk[i]))
536 			continue;
537 		rc = smcr_link_reg_buf(&lgr->lnk[i], snd_desc);
538 		if (rc)
539 			break;
540 	}
541 	up_write(&lgr->llc_conf_mutex);
542 	return rc;
543 }
544 
545 /* register the new rmb on all links */
546 static int smcr_lgr_reg_rmbs(struct smc_link *link,
547 			     struct smc_buf_desc *rmb_desc)
548 {
549 	struct smc_link_group *lgr = link->lgr;
550 	bool do_slow = false;
551 	int i, rc = 0;
552 
553 	rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
554 	if (rc)
555 		return rc;
556 
557 	down_read(&lgr->llc_conf_mutex);
558 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
559 		if (!smc_link_active(&lgr->lnk[i]))
560 			continue;
561 		if (!rmb_desc->is_reg_mr[link->link_idx]) {
562 			up_read(&lgr->llc_conf_mutex);
563 			goto slow_path;
564 		}
565 	}
566 	/* mr register already */
567 	goto fast_path;
568 slow_path:
569 	do_slow = true;
570 	/* protect against parallel smc_llc_cli_rkey_exchange() and
571 	 * parallel smcr_link_reg_buf()
572 	 */
573 	down_write(&lgr->llc_conf_mutex);
574 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
575 		if (!smc_link_active(&lgr->lnk[i]))
576 			continue;
577 		rc = smcr_link_reg_buf(&lgr->lnk[i], rmb_desc);
578 		if (rc)
579 			goto out;
580 	}
581 fast_path:
582 	/* exchange confirm_rkey msg with peer */
583 	rc = smc_llc_do_confirm_rkey(link, rmb_desc);
584 	if (rc) {
585 		rc = -EFAULT;
586 		goto out;
587 	}
588 	rmb_desc->is_conf_rkey = true;
589 out:
590 	do_slow ? up_write(&lgr->llc_conf_mutex) : up_read(&lgr->llc_conf_mutex);
591 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
592 	return rc;
593 }
594 
595 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
596 {
597 	struct smc_link *link = smc->conn.lnk;
598 	struct smc_llc_qentry *qentry;
599 	int rc;
600 
601 	/* receive CONFIRM LINK request from server over RoCE fabric */
602 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
603 			      SMC_LLC_CONFIRM_LINK);
604 	if (!qentry) {
605 		struct smc_clc_msg_decline dclc;
606 
607 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
608 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
609 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
610 	}
611 	smc_llc_save_peer_uid(qentry);
612 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
613 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
614 	if (rc)
615 		return SMC_CLC_DECL_RMBE_EC;
616 
617 	rc = smc_ib_modify_qp_rts(link);
618 	if (rc)
619 		return SMC_CLC_DECL_ERR_RDYLNK;
620 
621 	smc_wr_remember_qp_attr(link);
622 
623 	/* reg the sndbuf if it was vzalloced */
624 	if (smc->conn.sndbuf_desc->is_vm) {
625 		if (smcr_link_reg_buf(link, smc->conn.sndbuf_desc))
626 			return SMC_CLC_DECL_ERR_REGBUF;
627 	}
628 
629 	/* reg the rmb */
630 	if (smcr_link_reg_buf(link, smc->conn.rmb_desc))
631 		return SMC_CLC_DECL_ERR_REGBUF;
632 
633 	/* confirm_rkey is implicit on 1st contact */
634 	smc->conn.rmb_desc->is_conf_rkey = true;
635 
636 	/* send CONFIRM LINK response over RoCE fabric */
637 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
638 	if (rc < 0)
639 		return SMC_CLC_DECL_TIMEOUT_CL;
640 
641 	smc_llc_link_active(link);
642 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
643 
644 	if (link->lgr->max_links > 1) {
645 		/* optional 2nd link, receive ADD LINK request from server */
646 		qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
647 				      SMC_LLC_ADD_LINK);
648 		if (!qentry) {
649 			struct smc_clc_msg_decline dclc;
650 
651 			rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
652 					      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
653 			if (rc == -EAGAIN)
654 				rc = 0; /* no DECLINE received, go with one link */
655 			return rc;
656 		}
657 		smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
658 		smc_llc_cli_add_link(link, qentry);
659 	}
660 	return 0;
661 }
662 
663 static bool smc_isascii(char *hostname)
664 {
665 	int i;
666 
667 	for (i = 0; i < SMC_MAX_HOSTNAME_LEN; i++)
668 		if (!isascii(hostname[i]))
669 			return false;
670 	return true;
671 }
672 
673 static void smc_conn_save_peer_info_fce(struct smc_sock *smc,
674 					struct smc_clc_msg_accept_confirm *clc)
675 {
676 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
677 		(struct smc_clc_msg_accept_confirm_v2 *)clc;
678 	struct smc_clc_first_contact_ext *fce;
679 	int clc_v2_len;
680 
681 	if (clc->hdr.version == SMC_V1 ||
682 	    !(clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
683 		return;
684 
685 	if (smc->conn.lgr->is_smcd) {
686 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->d1.eid,
687 		       SMC_MAX_EID_LEN);
688 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
689 					 d1);
690 	} else {
691 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->r1.eid,
692 		       SMC_MAX_EID_LEN);
693 		clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
694 					 r1);
695 	}
696 	fce = (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) + clc_v2_len);
697 	smc->conn.lgr->peer_os = fce->os_type;
698 	smc->conn.lgr->peer_smc_release = fce->release;
699 	if (smc_isascii(fce->hostname))
700 		memcpy(smc->conn.lgr->peer_hostname, fce->hostname,
701 		       SMC_MAX_HOSTNAME_LEN);
702 }
703 
704 static void smcr_conn_save_peer_info(struct smc_sock *smc,
705 				     struct smc_clc_msg_accept_confirm *clc)
706 {
707 	int bufsize = smc_uncompress_bufsize(clc->r0.rmbe_size);
708 
709 	smc->conn.peer_rmbe_idx = clc->r0.rmbe_idx;
710 	smc->conn.local_tx_ctrl.token = ntohl(clc->r0.rmbe_alert_token);
711 	smc->conn.peer_rmbe_size = bufsize;
712 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
713 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
714 }
715 
716 static void smcd_conn_save_peer_info(struct smc_sock *smc,
717 				     struct smc_clc_msg_accept_confirm *clc)
718 {
719 	int bufsize = smc_uncompress_bufsize(clc->d0.dmbe_size);
720 
721 	smc->conn.peer_rmbe_idx = clc->d0.dmbe_idx;
722 	smc->conn.peer_token = clc->d0.token;
723 	/* msg header takes up space in the buffer */
724 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
725 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
726 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
727 }
728 
729 static void smc_conn_save_peer_info(struct smc_sock *smc,
730 				    struct smc_clc_msg_accept_confirm *clc)
731 {
732 	if (smc->conn.lgr->is_smcd)
733 		smcd_conn_save_peer_info(smc, clc);
734 	else
735 		smcr_conn_save_peer_info(smc, clc);
736 	smc_conn_save_peer_info_fce(smc, clc);
737 }
738 
739 static void smc_link_save_peer_info(struct smc_link *link,
740 				    struct smc_clc_msg_accept_confirm *clc,
741 				    struct smc_init_info *ini)
742 {
743 	link->peer_qpn = ntoh24(clc->r0.qpn);
744 	memcpy(link->peer_gid, ini->peer_gid, SMC_GID_SIZE);
745 	memcpy(link->peer_mac, ini->peer_mac, sizeof(link->peer_mac));
746 	link->peer_psn = ntoh24(clc->r0.psn);
747 	link->peer_mtu = clc->r0.qp_mtu;
748 }
749 
750 static void smc_stat_inc_fback_rsn_cnt(struct smc_sock *smc,
751 				       struct smc_stats_fback *fback_arr)
752 {
753 	int cnt;
754 
755 	for (cnt = 0; cnt < SMC_MAX_FBACK_RSN_CNT; cnt++) {
756 		if (fback_arr[cnt].fback_code == smc->fallback_rsn) {
757 			fback_arr[cnt].count++;
758 			break;
759 		}
760 		if (!fback_arr[cnt].fback_code) {
761 			fback_arr[cnt].fback_code = smc->fallback_rsn;
762 			fback_arr[cnt].count++;
763 			break;
764 		}
765 	}
766 }
767 
768 static void smc_stat_fallback(struct smc_sock *smc)
769 {
770 	struct net *net = sock_net(&smc->sk);
771 
772 	mutex_lock(&net->smc.mutex_fback_rsn);
773 	if (smc->listen_smc) {
774 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->srv);
775 		net->smc.fback_rsn->srv_fback_cnt++;
776 	} else {
777 		smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->clnt);
778 		net->smc.fback_rsn->clnt_fback_cnt++;
779 	}
780 	mutex_unlock(&net->smc.mutex_fback_rsn);
781 }
782 
783 /* must be called under rcu read lock */
784 static void smc_fback_wakeup_waitqueue(struct smc_sock *smc, void *key)
785 {
786 	struct socket_wq *wq;
787 	__poll_t flags;
788 
789 	wq = rcu_dereference(smc->sk.sk_wq);
790 	if (!skwq_has_sleeper(wq))
791 		return;
792 
793 	/* wake up smc sk->sk_wq */
794 	if (!key) {
795 		/* sk_state_change */
796 		wake_up_interruptible_all(&wq->wait);
797 	} else {
798 		flags = key_to_poll(key);
799 		if (flags & (EPOLLIN | EPOLLOUT))
800 			/* sk_data_ready or sk_write_space */
801 			wake_up_interruptible_sync_poll(&wq->wait, flags);
802 		else if (flags & EPOLLERR)
803 			/* sk_error_report */
804 			wake_up_interruptible_poll(&wq->wait, flags);
805 	}
806 }
807 
808 static int smc_fback_mark_woken(wait_queue_entry_t *wait,
809 				unsigned int mode, int sync, void *key)
810 {
811 	struct smc_mark_woken *mark =
812 		container_of(wait, struct smc_mark_woken, wait_entry);
813 
814 	mark->woken = true;
815 	mark->key = key;
816 	return 0;
817 }
818 
819 static void smc_fback_forward_wakeup(struct smc_sock *smc, struct sock *clcsk,
820 				     void (*clcsock_callback)(struct sock *sk))
821 {
822 	struct smc_mark_woken mark = { .woken = false };
823 	struct socket_wq *wq;
824 
825 	init_waitqueue_func_entry(&mark.wait_entry,
826 				  smc_fback_mark_woken);
827 	rcu_read_lock();
828 	wq = rcu_dereference(clcsk->sk_wq);
829 	if (!wq)
830 		goto out;
831 	add_wait_queue(sk_sleep(clcsk), &mark.wait_entry);
832 	clcsock_callback(clcsk);
833 	remove_wait_queue(sk_sleep(clcsk), &mark.wait_entry);
834 
835 	if (mark.woken)
836 		smc_fback_wakeup_waitqueue(smc, mark.key);
837 out:
838 	rcu_read_unlock();
839 }
840 
841 static void smc_fback_state_change(struct sock *clcsk)
842 {
843 	struct smc_sock *smc;
844 
845 	read_lock_bh(&clcsk->sk_callback_lock);
846 	smc = smc_clcsock_user_data(clcsk);
847 	if (smc)
848 		smc_fback_forward_wakeup(smc, clcsk,
849 					 smc->clcsk_state_change);
850 	read_unlock_bh(&clcsk->sk_callback_lock);
851 }
852 
853 static void smc_fback_data_ready(struct sock *clcsk)
854 {
855 	struct smc_sock *smc;
856 
857 	read_lock_bh(&clcsk->sk_callback_lock);
858 	smc = smc_clcsock_user_data(clcsk);
859 	if (smc)
860 		smc_fback_forward_wakeup(smc, clcsk,
861 					 smc->clcsk_data_ready);
862 	read_unlock_bh(&clcsk->sk_callback_lock);
863 }
864 
865 static void smc_fback_write_space(struct sock *clcsk)
866 {
867 	struct smc_sock *smc;
868 
869 	read_lock_bh(&clcsk->sk_callback_lock);
870 	smc = smc_clcsock_user_data(clcsk);
871 	if (smc)
872 		smc_fback_forward_wakeup(smc, clcsk,
873 					 smc->clcsk_write_space);
874 	read_unlock_bh(&clcsk->sk_callback_lock);
875 }
876 
877 static void smc_fback_error_report(struct sock *clcsk)
878 {
879 	struct smc_sock *smc;
880 
881 	read_lock_bh(&clcsk->sk_callback_lock);
882 	smc = smc_clcsock_user_data(clcsk);
883 	if (smc)
884 		smc_fback_forward_wakeup(smc, clcsk,
885 					 smc->clcsk_error_report);
886 	read_unlock_bh(&clcsk->sk_callback_lock);
887 }
888 
889 static void smc_fback_replace_callbacks(struct smc_sock *smc)
890 {
891 	struct sock *clcsk = smc->clcsock->sk;
892 
893 	write_lock_bh(&clcsk->sk_callback_lock);
894 	clcsk->sk_user_data = (void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
895 
896 	smc_clcsock_replace_cb(&clcsk->sk_state_change, smc_fback_state_change,
897 			       &smc->clcsk_state_change);
898 	smc_clcsock_replace_cb(&clcsk->sk_data_ready, smc_fback_data_ready,
899 			       &smc->clcsk_data_ready);
900 	smc_clcsock_replace_cb(&clcsk->sk_write_space, smc_fback_write_space,
901 			       &smc->clcsk_write_space);
902 	smc_clcsock_replace_cb(&clcsk->sk_error_report, smc_fback_error_report,
903 			       &smc->clcsk_error_report);
904 
905 	write_unlock_bh(&clcsk->sk_callback_lock);
906 }
907 
908 static int smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
909 {
910 	int rc = 0;
911 
912 	mutex_lock(&smc->clcsock_release_lock);
913 	if (!smc->clcsock) {
914 		rc = -EBADF;
915 		goto out;
916 	}
917 
918 	smc->use_fallback = true;
919 	smc->fallback_rsn = reason_code;
920 	smc_stat_fallback(smc);
921 	trace_smc_switch_to_fallback(smc, reason_code);
922 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
923 		smc->clcsock->file = smc->sk.sk_socket->file;
924 		smc->clcsock->file->private_data = smc->clcsock;
925 		smc->clcsock->wq.fasync_list =
926 			smc->sk.sk_socket->wq.fasync_list;
927 
928 		/* There might be some wait entries remaining
929 		 * in smc sk->sk_wq and they should be woken up
930 		 * as clcsock's wait queue is woken up.
931 		 */
932 		smc_fback_replace_callbacks(smc);
933 	}
934 out:
935 	mutex_unlock(&smc->clcsock_release_lock);
936 	return rc;
937 }
938 
939 /* fall back during connect */
940 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
941 {
942 	struct net *net = sock_net(&smc->sk);
943 	int rc = 0;
944 
945 	rc = smc_switch_to_fallback(smc, reason_code);
946 	if (rc) { /* fallback fails */
947 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
948 		if (smc->sk.sk_state == SMC_INIT)
949 			sock_put(&smc->sk); /* passive closing */
950 		return rc;
951 	}
952 	smc_copy_sock_settings_to_clc(smc);
953 	smc->connect_nonblock = 0;
954 	if (smc->sk.sk_state == SMC_INIT)
955 		smc->sk.sk_state = SMC_ACTIVE;
956 	return 0;
957 }
958 
959 /* decline and fall back during connect */
960 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
961 					u8 version)
962 {
963 	struct net *net = sock_net(&smc->sk);
964 	int rc;
965 
966 	if (reason_code < 0) { /* error, fallback is not possible */
967 		this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
968 		if (smc->sk.sk_state == SMC_INIT)
969 			sock_put(&smc->sk); /* passive closing */
970 		return reason_code;
971 	}
972 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
973 		rc = smc_clc_send_decline(smc, reason_code, version);
974 		if (rc < 0) {
975 			this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
976 			if (smc->sk.sk_state == SMC_INIT)
977 				sock_put(&smc->sk); /* passive closing */
978 			return rc;
979 		}
980 	}
981 	return smc_connect_fallback(smc, reason_code);
982 }
983 
984 static void smc_conn_abort(struct smc_sock *smc, int local_first)
985 {
986 	struct smc_connection *conn = &smc->conn;
987 	struct smc_link_group *lgr = conn->lgr;
988 	bool lgr_valid = false;
989 
990 	if (smc_conn_lgr_valid(conn))
991 		lgr_valid = true;
992 
993 	smc_conn_free(conn);
994 	if (local_first && lgr_valid)
995 		smc_lgr_cleanup_early(lgr);
996 }
997 
998 /* check if there is a rdma device available for this connection. */
999 /* called for connect and listen */
1000 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
1001 {
1002 	/* PNET table look up: search active ib_device and port
1003 	 * within same PNETID that also contains the ethernet device
1004 	 * used for the internal TCP socket
1005 	 */
1006 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
1007 	if (!ini->check_smcrv2 && !ini->ib_dev)
1008 		return SMC_CLC_DECL_NOSMCRDEV;
1009 	if (ini->check_smcrv2 && !ini->smcrv2.ib_dev_v2)
1010 		return SMC_CLC_DECL_NOSMCRDEV;
1011 	return 0;
1012 }
1013 
1014 /* check if there is an ISM device available for this connection. */
1015 /* called for connect and listen */
1016 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
1017 {
1018 	/* Find ISM device with same PNETID as connecting interface  */
1019 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
1020 	if (!ini->ism_dev[0])
1021 		return SMC_CLC_DECL_NOSMCDDEV;
1022 	else
1023 		ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
1024 	return 0;
1025 }
1026 
1027 /* is chid unique for the ism devices that are already determined? */
1028 static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
1029 					   int cnt)
1030 {
1031 	int i = (!ini->ism_dev[0]) ? 1 : 0;
1032 
1033 	for (; i < cnt; i++)
1034 		if (ini->ism_chid[i] == chid)
1035 			return false;
1036 	return true;
1037 }
1038 
1039 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
1040  * PNETID matching net_device)
1041  */
1042 static int smc_find_ism_v2_device_clnt(struct smc_sock *smc,
1043 				       struct smc_init_info *ini)
1044 {
1045 	int rc = SMC_CLC_DECL_NOSMCDDEV;
1046 	struct smcd_dev *smcd;
1047 	int i = 1;
1048 	u16 chid;
1049 
1050 	if (smcd_indicated(ini->smc_type_v1))
1051 		rc = 0;		/* already initialized for V1 */
1052 	mutex_lock(&smcd_dev_list.mutex);
1053 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1054 		if (smcd->going_away || smcd == ini->ism_dev[0])
1055 			continue;
1056 		chid = smc_ism_get_chid(smcd);
1057 		if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
1058 			continue;
1059 		if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
1060 		    smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
1061 			ini->ism_dev[i] = smcd;
1062 			ini->ism_chid[i] = chid;
1063 			ini->is_smcd = true;
1064 			rc = 0;
1065 			i++;
1066 			if (i > SMC_MAX_ISM_DEVS)
1067 				break;
1068 		}
1069 	}
1070 	mutex_unlock(&smcd_dev_list.mutex);
1071 	ini->ism_offered_cnt = i - 1;
1072 	if (!ini->ism_dev[0] && !ini->ism_dev[1])
1073 		ini->smcd_version = 0;
1074 
1075 	return rc;
1076 }
1077 
1078 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
1079 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
1080 				      struct smc_init_info *ini)
1081 {
1082 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev[0], ini->vlan_id))
1083 		return SMC_CLC_DECL_ISMVLANERR;
1084 	return 0;
1085 }
1086 
1087 static int smc_find_proposal_devices(struct smc_sock *smc,
1088 				     struct smc_init_info *ini)
1089 {
1090 	int rc = 0;
1091 
1092 	/* check if there is an ism device available */
1093 	if (!(ini->smcd_version & SMC_V1) ||
1094 	    smc_find_ism_device(smc, ini) ||
1095 	    smc_connect_ism_vlan_setup(smc, ini))
1096 		ini->smcd_version &= ~SMC_V1;
1097 	/* else ISM V1 is supported for this connection */
1098 
1099 	/* check if there is an rdma device available */
1100 	if (!(ini->smcr_version & SMC_V1) ||
1101 	    smc_find_rdma_device(smc, ini))
1102 		ini->smcr_version &= ~SMC_V1;
1103 	/* else RDMA is supported for this connection */
1104 
1105 	ini->smc_type_v1 = smc_indicated_type(ini->smcd_version & SMC_V1,
1106 					      ini->smcr_version & SMC_V1);
1107 
1108 	/* check if there is an ism v2 device available */
1109 	if (!(ini->smcd_version & SMC_V2) ||
1110 	    !smc_ism_is_v2_capable() ||
1111 	    smc_find_ism_v2_device_clnt(smc, ini))
1112 		ini->smcd_version &= ~SMC_V2;
1113 
1114 	/* check if there is an rdma v2 device available */
1115 	ini->check_smcrv2 = true;
1116 	ini->smcrv2.saddr = smc->clcsock->sk->sk_rcv_saddr;
1117 	if (!(ini->smcr_version & SMC_V2) ||
1118 	    smc->clcsock->sk->sk_family != AF_INET ||
1119 	    !smc_clc_ueid_count() ||
1120 	    smc_find_rdma_device(smc, ini))
1121 		ini->smcr_version &= ~SMC_V2;
1122 	ini->check_smcrv2 = false;
1123 
1124 	ini->smc_type_v2 = smc_indicated_type(ini->smcd_version & SMC_V2,
1125 					      ini->smcr_version & SMC_V2);
1126 
1127 	/* if neither ISM nor RDMA are supported, fallback */
1128 	if (ini->smc_type_v1 == SMC_TYPE_N && ini->smc_type_v2 == SMC_TYPE_N)
1129 		rc = SMC_CLC_DECL_NOSMCDEV;
1130 
1131 	return rc;
1132 }
1133 
1134 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
1135  * used, the VLAN ID will be registered again during the connection setup.
1136  */
1137 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
1138 					struct smc_init_info *ini)
1139 {
1140 	if (!smcd_indicated(ini->smc_type_v1))
1141 		return 0;
1142 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev[0], ini->vlan_id))
1143 		return SMC_CLC_DECL_CNFERR;
1144 	return 0;
1145 }
1146 
1147 #define SMC_CLC_MAX_ACCEPT_LEN \
1148 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
1149 	 sizeof(struct smc_clc_first_contact_ext_v2x) + \
1150 	 sizeof(struct smc_clc_msg_trail))
1151 
1152 /* CLC handshake during connect */
1153 static int smc_connect_clc(struct smc_sock *smc,
1154 			   struct smc_clc_msg_accept_confirm_v2 *aclc2,
1155 			   struct smc_init_info *ini)
1156 {
1157 	int rc = 0;
1158 
1159 	/* do inband token exchange */
1160 	rc = smc_clc_send_proposal(smc, ini);
1161 	if (rc)
1162 		return rc;
1163 	/* receive SMC Accept CLC message */
1164 	return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
1165 				SMC_CLC_ACCEPT, CLC_WAIT_TIME);
1166 }
1167 
1168 void smc_fill_gid_list(struct smc_link_group *lgr,
1169 		       struct smc_gidlist *gidlist,
1170 		       struct smc_ib_device *known_dev, u8 *known_gid)
1171 {
1172 	struct smc_init_info *alt_ini = NULL;
1173 
1174 	memset(gidlist, 0, sizeof(*gidlist));
1175 	memcpy(gidlist->list[gidlist->len++], known_gid, SMC_GID_SIZE);
1176 
1177 	alt_ini = kzalloc(sizeof(*alt_ini), GFP_KERNEL);
1178 	if (!alt_ini)
1179 		goto out;
1180 
1181 	alt_ini->vlan_id = lgr->vlan_id;
1182 	alt_ini->check_smcrv2 = true;
1183 	alt_ini->smcrv2.saddr = lgr->saddr;
1184 	smc_pnet_find_alt_roce(lgr, alt_ini, known_dev);
1185 
1186 	if (!alt_ini->smcrv2.ib_dev_v2)
1187 		goto out;
1188 
1189 	memcpy(gidlist->list[gidlist->len++], alt_ini->smcrv2.ib_gid_v2,
1190 	       SMC_GID_SIZE);
1191 
1192 out:
1193 	kfree(alt_ini);
1194 }
1195 
1196 static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
1197 				       struct smc_clc_msg_accept_confirm *aclc,
1198 				       struct smc_init_info *ini)
1199 {
1200 	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1201 		(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1202 	struct smc_clc_first_contact_ext *fce =
1203 		smc_get_clc_first_contact_ext(clc_v2, false);
1204 	struct net *net = sock_net(&smc->sk);
1205 	int rc;
1206 
1207 	if (!ini->first_contact_peer || aclc->hdr.version == SMC_V1)
1208 		return 0;
1209 
1210 	if (fce->v2_direct) {
1211 		memcpy(ini->smcrv2.nexthop_mac, &aclc->r0.lcl.mac, ETH_ALEN);
1212 		ini->smcrv2.uses_gateway = false;
1213 	} else {
1214 		if (smc_ib_find_route(net, smc->clcsock->sk->sk_rcv_saddr,
1215 				      smc_ib_gid_to_ipv4(aclc->r0.lcl.gid),
1216 				      ini->smcrv2.nexthop_mac,
1217 				      &ini->smcrv2.uses_gateway))
1218 			return SMC_CLC_DECL_NOROUTE;
1219 		if (!ini->smcrv2.uses_gateway) {
1220 			/* mismatch: peer claims indirect, but its direct */
1221 			return SMC_CLC_DECL_NOINDIRECT;
1222 		}
1223 	}
1224 
1225 	ini->release_nr = fce->release;
1226 	rc = smc_clc_clnt_v2x_features_validate(fce, ini);
1227 	if (rc)
1228 		return rc;
1229 
1230 	return 0;
1231 }
1232 
1233 /* setup for RDMA connection of client */
1234 static int smc_connect_rdma(struct smc_sock *smc,
1235 			    struct smc_clc_msg_accept_confirm *aclc,
1236 			    struct smc_init_info *ini)
1237 {
1238 	int i, reason_code = 0;
1239 	struct smc_link *link;
1240 	u8 *eid = NULL;
1241 
1242 	ini->is_smcd = false;
1243 	ini->ib_clcqpn = ntoh24(aclc->r0.qpn);
1244 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1245 	memcpy(ini->peer_systemid, aclc->r0.lcl.id_for_peer, SMC_SYSTEMID_LEN);
1246 	memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
1247 	memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
1248 	ini->max_conns = SMC_CONN_PER_LGR_MAX;
1249 	ini->max_links = SMC_LINKS_ADD_LNK_MAX;
1250 
1251 	reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
1252 	if (reason_code)
1253 		return reason_code;
1254 
1255 	mutex_lock(&smc_client_lgr_pending);
1256 	reason_code = smc_conn_create(smc, ini);
1257 	if (reason_code) {
1258 		mutex_unlock(&smc_client_lgr_pending);
1259 		return reason_code;
1260 	}
1261 
1262 	smc_conn_save_peer_info(smc, aclc);
1263 
1264 	if (ini->first_contact_local) {
1265 		link = smc->conn.lnk;
1266 	} else {
1267 		/* set link that was assigned by server */
1268 		link = NULL;
1269 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1270 			struct smc_link *l = &smc->conn.lgr->lnk[i];
1271 
1272 			if (l->peer_qpn == ntoh24(aclc->r0.qpn) &&
1273 			    !memcmp(l->peer_gid, &aclc->r0.lcl.gid,
1274 				    SMC_GID_SIZE) &&
1275 			    (aclc->hdr.version > SMC_V1 ||
1276 			     !memcmp(l->peer_mac, &aclc->r0.lcl.mac,
1277 				     sizeof(l->peer_mac)))) {
1278 				link = l;
1279 				break;
1280 			}
1281 		}
1282 		if (!link) {
1283 			reason_code = SMC_CLC_DECL_NOSRVLINK;
1284 			goto connect_abort;
1285 		}
1286 		smc_switch_link_and_count(&smc->conn, link);
1287 	}
1288 
1289 	/* create send buffer and rmb */
1290 	if (smc_buf_create(smc, false)) {
1291 		reason_code = SMC_CLC_DECL_MEM;
1292 		goto connect_abort;
1293 	}
1294 
1295 	if (ini->first_contact_local)
1296 		smc_link_save_peer_info(link, aclc, ini);
1297 
1298 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc)) {
1299 		reason_code = SMC_CLC_DECL_ERR_RTOK;
1300 		goto connect_abort;
1301 	}
1302 
1303 	smc_close_init(smc);
1304 	smc_rx_init(smc);
1305 
1306 	if (ini->first_contact_local) {
1307 		if (smc_ib_ready_link(link)) {
1308 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
1309 			goto connect_abort;
1310 		}
1311 	} else {
1312 		/* reg sendbufs if they were vzalloced */
1313 		if (smc->conn.sndbuf_desc->is_vm) {
1314 			if (smcr_lgr_reg_sndbufs(link, smc->conn.sndbuf_desc)) {
1315 				reason_code = SMC_CLC_DECL_ERR_REGBUF;
1316 				goto connect_abort;
1317 			}
1318 		}
1319 		if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc)) {
1320 			reason_code = SMC_CLC_DECL_ERR_REGBUF;
1321 			goto connect_abort;
1322 		}
1323 	}
1324 
1325 	if (aclc->hdr.version > SMC_V1) {
1326 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1327 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1328 
1329 		eid = clc_v2->r1.eid;
1330 		if (ini->first_contact_local)
1331 			smc_fill_gid_list(link->lgr, &ini->smcrv2.gidlist,
1332 					  link->smcibdev, link->gid);
1333 	}
1334 
1335 	reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
1336 					   aclc->hdr.version, eid, ini);
1337 	if (reason_code)
1338 		goto connect_abort;
1339 
1340 	smc_tx_init(smc);
1341 
1342 	if (ini->first_contact_local) {
1343 		/* QP confirmation over RoCE fabric */
1344 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1345 		reason_code = smcr_clnt_conf_first_link(smc);
1346 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1347 		if (reason_code)
1348 			goto connect_abort;
1349 	}
1350 	mutex_unlock(&smc_client_lgr_pending);
1351 
1352 	smc_copy_sock_settings_to_clc(smc);
1353 	smc->connect_nonblock = 0;
1354 	if (smc->sk.sk_state == SMC_INIT)
1355 		smc->sk.sk_state = SMC_ACTIVE;
1356 
1357 	return 0;
1358 connect_abort:
1359 	smc_conn_abort(smc, ini->first_contact_local);
1360 	mutex_unlock(&smc_client_lgr_pending);
1361 	smc->connect_nonblock = 0;
1362 
1363 	return reason_code;
1364 }
1365 
1366 /* The server has chosen one of the proposed ISM devices for the communication.
1367  * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
1368  */
1369 static int
1370 smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
1371 			       struct smc_init_info *ini)
1372 {
1373 	int i;
1374 
1375 	for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
1376 		if (ini->ism_chid[i] == ntohs(aclc->d1.chid)) {
1377 			ini->ism_selected = i;
1378 			return 0;
1379 		}
1380 	}
1381 
1382 	return -EPROTO;
1383 }
1384 
1385 /* setup for ISM connection of client */
1386 static int smc_connect_ism(struct smc_sock *smc,
1387 			   struct smc_clc_msg_accept_confirm *aclc,
1388 			   struct smc_init_info *ini)
1389 {
1390 	u8 *eid = NULL;
1391 	int rc = 0;
1392 
1393 	ini->is_smcd = true;
1394 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
1395 
1396 	if (aclc->hdr.version == SMC_V2) {
1397 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
1398 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1399 
1400 		if (ini->first_contact_peer) {
1401 			struct smc_clc_first_contact_ext *fce =
1402 				smc_get_clc_first_contact_ext(aclc_v2, true);
1403 
1404 			ini->release_nr = fce->release;
1405 			rc = smc_clc_clnt_v2x_features_validate(fce, ini);
1406 			if (rc)
1407 				return rc;
1408 		}
1409 
1410 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
1411 		if (rc)
1412 			return rc;
1413 	}
1414 	ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
1415 
1416 	/* there is only one lgr role for SMC-D; use server lock */
1417 	mutex_lock(&smc_server_lgr_pending);
1418 	rc = smc_conn_create(smc, ini);
1419 	if (rc) {
1420 		mutex_unlock(&smc_server_lgr_pending);
1421 		return rc;
1422 	}
1423 
1424 	/* Create send and receive buffers */
1425 	rc = smc_buf_create(smc, true);
1426 	if (rc) {
1427 		rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
1428 		goto connect_abort;
1429 	}
1430 
1431 	smc_conn_save_peer_info(smc, aclc);
1432 	smc_close_init(smc);
1433 	smc_rx_init(smc);
1434 	smc_tx_init(smc);
1435 
1436 	if (aclc->hdr.version > SMC_V1) {
1437 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
1438 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
1439 
1440 		eid = clc_v2->d1.eid;
1441 	}
1442 
1443 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
1444 				  aclc->hdr.version, eid, ini);
1445 	if (rc)
1446 		goto connect_abort;
1447 	mutex_unlock(&smc_server_lgr_pending);
1448 
1449 	smc_copy_sock_settings_to_clc(smc);
1450 	smc->connect_nonblock = 0;
1451 	if (smc->sk.sk_state == SMC_INIT)
1452 		smc->sk.sk_state = SMC_ACTIVE;
1453 
1454 	return 0;
1455 connect_abort:
1456 	smc_conn_abort(smc, ini->first_contact_local);
1457 	mutex_unlock(&smc_server_lgr_pending);
1458 	smc->connect_nonblock = 0;
1459 
1460 	return rc;
1461 }
1462 
1463 /* check if received accept type and version matches a proposed one */
1464 static int smc_connect_check_aclc(struct smc_init_info *ini,
1465 				  struct smc_clc_msg_accept_confirm *aclc)
1466 {
1467 	if (aclc->hdr.typev1 != SMC_TYPE_R &&
1468 	    aclc->hdr.typev1 != SMC_TYPE_D)
1469 		return SMC_CLC_DECL_MODEUNSUPP;
1470 
1471 	if (aclc->hdr.version >= SMC_V2) {
1472 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1473 		     !smcr_indicated(ini->smc_type_v2)) ||
1474 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1475 		     !smcd_indicated(ini->smc_type_v2)))
1476 			return SMC_CLC_DECL_MODEUNSUPP;
1477 	} else {
1478 		if ((aclc->hdr.typev1 == SMC_TYPE_R &&
1479 		     !smcr_indicated(ini->smc_type_v1)) ||
1480 		    (aclc->hdr.typev1 == SMC_TYPE_D &&
1481 		     !smcd_indicated(ini->smc_type_v1)))
1482 			return SMC_CLC_DECL_MODEUNSUPP;
1483 	}
1484 
1485 	return 0;
1486 }
1487 
1488 /* perform steps before actually connecting */
1489 static int __smc_connect(struct smc_sock *smc)
1490 {
1491 	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
1492 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
1493 	struct smc_clc_msg_accept_confirm *aclc;
1494 	struct smc_init_info *ini = NULL;
1495 	u8 *buf = NULL;
1496 	int rc = 0;
1497 
1498 	if (smc->use_fallback)
1499 		return smc_connect_fallback(smc, smc->fallback_rsn);
1500 
1501 	/* if peer has not signalled SMC-capability, fall back */
1502 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
1503 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
1504 
1505 	/* IPSec connections opt out of SMC optimizations */
1506 	if (using_ipsec(smc))
1507 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
1508 						    version);
1509 
1510 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1511 	if (!ini)
1512 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
1513 						    version);
1514 
1515 	ini->smcd_version = SMC_V1 | SMC_V2;
1516 	ini->smcr_version = SMC_V1 | SMC_V2;
1517 	ini->smc_type_v1 = SMC_TYPE_B;
1518 	ini->smc_type_v2 = SMC_TYPE_B;
1519 
1520 	/* get vlan id from IP device */
1521 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
1522 		ini->smcd_version &= ~SMC_V1;
1523 		ini->smcr_version = 0;
1524 		ini->smc_type_v1 = SMC_TYPE_N;
1525 		if (!ini->smcd_version) {
1526 			rc = SMC_CLC_DECL_GETVLANERR;
1527 			goto fallback;
1528 		}
1529 	}
1530 
1531 	rc = smc_find_proposal_devices(smc, ini);
1532 	if (rc)
1533 		goto fallback;
1534 
1535 	buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
1536 	if (!buf) {
1537 		rc = SMC_CLC_DECL_MEM;
1538 		goto fallback;
1539 	}
1540 	aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
1541 	aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
1542 
1543 	/* perform CLC handshake */
1544 	rc = smc_connect_clc(smc, aclc2, ini);
1545 	if (rc) {
1546 		/* -EAGAIN on timeout, see tcp_recvmsg() */
1547 		if (rc == -EAGAIN) {
1548 			rc = -ETIMEDOUT;
1549 			smc->sk.sk_err = ETIMEDOUT;
1550 		}
1551 		goto vlan_cleanup;
1552 	}
1553 
1554 	/* check if smc modes and versions of CLC proposal and accept match */
1555 	rc = smc_connect_check_aclc(ini, aclc);
1556 	version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
1557 	if (rc)
1558 		goto vlan_cleanup;
1559 
1560 	/* depending on previous steps, connect using rdma or ism */
1561 	if (aclc->hdr.typev1 == SMC_TYPE_R) {
1562 		ini->smcr_version = version;
1563 		rc = smc_connect_rdma(smc, aclc, ini);
1564 	} else if (aclc->hdr.typev1 == SMC_TYPE_D) {
1565 		ini->smcd_version = version;
1566 		rc = smc_connect_ism(smc, aclc, ini);
1567 	}
1568 	if (rc)
1569 		goto vlan_cleanup;
1570 
1571 	SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc);
1572 	smc_connect_ism_vlan_cleanup(smc, ini);
1573 	kfree(buf);
1574 	kfree(ini);
1575 	return 0;
1576 
1577 vlan_cleanup:
1578 	smc_connect_ism_vlan_cleanup(smc, ini);
1579 	kfree(buf);
1580 fallback:
1581 	kfree(ini);
1582 	return smc_connect_decline_fallback(smc, rc, version);
1583 }
1584 
1585 static void smc_connect_work(struct work_struct *work)
1586 {
1587 	struct smc_sock *smc = container_of(work, struct smc_sock,
1588 					    connect_work);
1589 	long timeo = smc->sk.sk_sndtimeo;
1590 	int rc = 0;
1591 
1592 	if (!timeo)
1593 		timeo = MAX_SCHEDULE_TIMEOUT;
1594 	lock_sock(smc->clcsock->sk);
1595 	if (smc->clcsock->sk->sk_err) {
1596 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1597 	} else if ((1 << smc->clcsock->sk->sk_state) &
1598 					(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
1599 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
1600 		if ((rc == -EPIPE) &&
1601 		    ((1 << smc->clcsock->sk->sk_state) &
1602 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
1603 			rc = 0;
1604 	}
1605 	release_sock(smc->clcsock->sk);
1606 	lock_sock(&smc->sk);
1607 	if (rc != 0 || smc->sk.sk_err) {
1608 		smc->sk.sk_state = SMC_CLOSED;
1609 		if (rc == -EPIPE || rc == -EAGAIN)
1610 			smc->sk.sk_err = EPIPE;
1611 		else if (rc == -ECONNREFUSED)
1612 			smc->sk.sk_err = ECONNREFUSED;
1613 		else if (signal_pending(current))
1614 			smc->sk.sk_err = -sock_intr_errno(timeo);
1615 		sock_put(&smc->sk); /* passive closing */
1616 		goto out;
1617 	}
1618 
1619 	rc = __smc_connect(smc);
1620 	if (rc < 0)
1621 		smc->sk.sk_err = -rc;
1622 
1623 out:
1624 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
1625 		if (smc->sk.sk_err) {
1626 			smc->sk.sk_state_change(&smc->sk);
1627 		} else { /* allow polling before and after fallback decision */
1628 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
1629 			smc->sk.sk_write_space(&smc->sk);
1630 		}
1631 	}
1632 	release_sock(&smc->sk);
1633 }
1634 
1635 static int smc_connect(struct socket *sock, struct sockaddr *addr,
1636 		       int alen, int flags)
1637 {
1638 	struct sock *sk = sock->sk;
1639 	struct smc_sock *smc;
1640 	int rc = -EINVAL;
1641 
1642 	smc = smc_sk(sk);
1643 
1644 	/* separate smc parameter checking to be safe */
1645 	if (alen < sizeof(addr->sa_family))
1646 		goto out_err;
1647 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
1648 		goto out_err;
1649 
1650 	lock_sock(sk);
1651 	switch (sock->state) {
1652 	default:
1653 		rc = -EINVAL;
1654 		goto out;
1655 	case SS_CONNECTED:
1656 		rc = sk->sk_state == SMC_ACTIVE ? -EISCONN : -EINVAL;
1657 		goto out;
1658 	case SS_CONNECTING:
1659 		if (sk->sk_state == SMC_ACTIVE)
1660 			goto connected;
1661 		break;
1662 	case SS_UNCONNECTED:
1663 		sock->state = SS_CONNECTING;
1664 		break;
1665 	}
1666 
1667 	switch (sk->sk_state) {
1668 	default:
1669 		goto out;
1670 	case SMC_CLOSED:
1671 		rc = sock_error(sk) ? : -ECONNABORTED;
1672 		sock->state = SS_UNCONNECTED;
1673 		goto out;
1674 	case SMC_ACTIVE:
1675 		rc = -EISCONN;
1676 		goto out;
1677 	case SMC_INIT:
1678 		break;
1679 	}
1680 
1681 	smc_copy_sock_settings_to_clc(smc);
1682 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1683 	if (smc->connect_nonblock) {
1684 		rc = -EALREADY;
1685 		goto out;
1686 	}
1687 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
1688 	if (rc && rc != -EINPROGRESS)
1689 		goto out;
1690 
1691 	if (smc->use_fallback) {
1692 		sock->state = rc ? SS_CONNECTING : SS_CONNECTED;
1693 		goto out;
1694 	}
1695 	sock_hold(&smc->sk); /* sock put in passive closing */
1696 	if (flags & O_NONBLOCK) {
1697 		if (queue_work(smc_hs_wq, &smc->connect_work))
1698 			smc->connect_nonblock = 1;
1699 		rc = -EINPROGRESS;
1700 		goto out;
1701 	} else {
1702 		rc = __smc_connect(smc);
1703 		if (rc < 0)
1704 			goto out;
1705 	}
1706 
1707 connected:
1708 	rc = 0;
1709 	sock->state = SS_CONNECTED;
1710 out:
1711 	release_sock(sk);
1712 out_err:
1713 	return rc;
1714 }
1715 
1716 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
1717 {
1718 	struct socket *new_clcsock = NULL;
1719 	struct sock *lsk = &lsmc->sk;
1720 	struct sock *new_sk;
1721 	int rc = -EINVAL;
1722 
1723 	release_sock(lsk);
1724 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
1725 	if (!new_sk) {
1726 		rc = -ENOMEM;
1727 		lsk->sk_err = ENOMEM;
1728 		*new_smc = NULL;
1729 		lock_sock(lsk);
1730 		goto out;
1731 	}
1732 	*new_smc = smc_sk(new_sk);
1733 
1734 	mutex_lock(&lsmc->clcsock_release_lock);
1735 	if (lsmc->clcsock)
1736 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
1737 	mutex_unlock(&lsmc->clcsock_release_lock);
1738 	lock_sock(lsk);
1739 	if  (rc < 0 && rc != -EAGAIN)
1740 		lsk->sk_err = -rc;
1741 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
1742 		new_sk->sk_prot->unhash(new_sk);
1743 		if (new_clcsock)
1744 			sock_release(new_clcsock);
1745 		new_sk->sk_state = SMC_CLOSED;
1746 		smc_sock_set_flag(new_sk, SOCK_DEAD);
1747 		sock_put(new_sk); /* final */
1748 		*new_smc = NULL;
1749 		goto out;
1750 	}
1751 
1752 	/* new clcsock has inherited the smc listen-specific sk_data_ready
1753 	 * function; switch it back to the original sk_data_ready function
1754 	 */
1755 	new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
1756 
1757 	/* if new clcsock has also inherited the fallback-specific callback
1758 	 * functions, switch them back to the original ones.
1759 	 */
1760 	if (lsmc->use_fallback) {
1761 		if (lsmc->clcsk_state_change)
1762 			new_clcsock->sk->sk_state_change = lsmc->clcsk_state_change;
1763 		if (lsmc->clcsk_write_space)
1764 			new_clcsock->sk->sk_write_space = lsmc->clcsk_write_space;
1765 		if (lsmc->clcsk_error_report)
1766 			new_clcsock->sk->sk_error_report = lsmc->clcsk_error_report;
1767 	}
1768 
1769 	(*new_smc)->clcsock = new_clcsock;
1770 out:
1771 	return rc;
1772 }
1773 
1774 /* add a just created sock to the accept queue of the listen sock as
1775  * candidate for a following socket accept call from user space
1776  */
1777 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
1778 {
1779 	struct smc_sock *par = smc_sk(parent);
1780 
1781 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
1782 	spin_lock(&par->accept_q_lock);
1783 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
1784 	spin_unlock(&par->accept_q_lock);
1785 	sk_acceptq_added(parent);
1786 }
1787 
1788 /* remove a socket from the accept queue of its parental listening socket */
1789 static void smc_accept_unlink(struct sock *sk)
1790 {
1791 	struct smc_sock *par = smc_sk(sk)->listen_smc;
1792 
1793 	spin_lock(&par->accept_q_lock);
1794 	list_del_init(&smc_sk(sk)->accept_q);
1795 	spin_unlock(&par->accept_q_lock);
1796 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
1797 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
1798 }
1799 
1800 /* remove a sock from the accept queue to bind it to a new socket created
1801  * for a socket accept call from user space
1802  */
1803 struct sock *smc_accept_dequeue(struct sock *parent,
1804 				struct socket *new_sock)
1805 {
1806 	struct smc_sock *isk, *n;
1807 	struct sock *new_sk;
1808 
1809 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1810 		new_sk = (struct sock *)isk;
1811 
1812 		smc_accept_unlink(new_sk);
1813 		if (new_sk->sk_state == SMC_CLOSED) {
1814 			new_sk->sk_prot->unhash(new_sk);
1815 			if (isk->clcsock) {
1816 				sock_release(isk->clcsock);
1817 				isk->clcsock = NULL;
1818 			}
1819 			sock_put(new_sk); /* final */
1820 			continue;
1821 		}
1822 		if (new_sock) {
1823 			sock_graft(new_sk, new_sock);
1824 			new_sock->state = SS_CONNECTED;
1825 			if (isk->use_fallback) {
1826 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1827 				isk->clcsock->file->private_data = isk->clcsock;
1828 			}
1829 		}
1830 		return new_sk;
1831 	}
1832 	return NULL;
1833 }
1834 
1835 /* clean up for a created but never accepted sock */
1836 void smc_close_non_accepted(struct sock *sk)
1837 {
1838 	struct smc_sock *smc = smc_sk(sk);
1839 
1840 	sock_hold(sk); /* sock_put below */
1841 	lock_sock(sk);
1842 	if (!sk->sk_lingertime)
1843 		/* wait for peer closing */
1844 		WRITE_ONCE(sk->sk_lingertime, SMC_MAX_STREAM_WAIT_TIMEOUT);
1845 	__smc_release(smc);
1846 	release_sock(sk);
1847 	sock_put(sk); /* sock_hold above */
1848 	sock_put(sk); /* final sock_put */
1849 }
1850 
1851 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1852 {
1853 	struct smc_link *link = smc->conn.lnk;
1854 	struct smc_llc_qentry *qentry;
1855 	int rc;
1856 
1857 	/* reg the sndbuf if it was vzalloced*/
1858 	if (smc->conn.sndbuf_desc->is_vm) {
1859 		if (smcr_link_reg_buf(link, smc->conn.sndbuf_desc))
1860 			return SMC_CLC_DECL_ERR_REGBUF;
1861 	}
1862 
1863 	/* reg the rmb */
1864 	if (smcr_link_reg_buf(link, smc->conn.rmb_desc))
1865 		return SMC_CLC_DECL_ERR_REGBUF;
1866 
1867 	/* send CONFIRM LINK request to client over the RoCE fabric */
1868 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1869 	if (rc < 0)
1870 		return SMC_CLC_DECL_TIMEOUT_CL;
1871 
1872 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1873 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1874 			      SMC_LLC_CONFIRM_LINK);
1875 	if (!qentry) {
1876 		struct smc_clc_msg_decline dclc;
1877 
1878 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1879 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1880 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1881 	}
1882 	smc_llc_save_peer_uid(qentry);
1883 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1884 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1885 	if (rc)
1886 		return SMC_CLC_DECL_RMBE_EC;
1887 
1888 	/* confirm_rkey is implicit on 1st contact */
1889 	smc->conn.rmb_desc->is_conf_rkey = true;
1890 
1891 	smc_llc_link_active(link);
1892 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1893 
1894 	if (link->lgr->max_links > 1) {
1895 		down_write(&link->lgr->llc_conf_mutex);
1896 		/* initial contact - try to establish second link */
1897 		smc_llc_srv_add_link(link, NULL);
1898 		up_write(&link->lgr->llc_conf_mutex);
1899 	}
1900 	return 0;
1901 }
1902 
1903 /* listen worker: finish */
1904 static void smc_listen_out(struct smc_sock *new_smc)
1905 {
1906 	struct smc_sock *lsmc = new_smc->listen_smc;
1907 	struct sock *newsmcsk = &new_smc->sk;
1908 
1909 	if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
1910 		atomic_dec(&lsmc->queued_smc_hs);
1911 
1912 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1913 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1914 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1915 		release_sock(&lsmc->sk);
1916 	} else { /* no longer listening */
1917 		smc_close_non_accepted(newsmcsk);
1918 	}
1919 
1920 	/* Wake up accept */
1921 	lsmc->sk.sk_data_ready(&lsmc->sk);
1922 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1923 }
1924 
1925 /* listen worker: finish in state connected */
1926 static void smc_listen_out_connected(struct smc_sock *new_smc)
1927 {
1928 	struct sock *newsmcsk = &new_smc->sk;
1929 
1930 	if (newsmcsk->sk_state == SMC_INIT)
1931 		newsmcsk->sk_state = SMC_ACTIVE;
1932 
1933 	smc_listen_out(new_smc);
1934 }
1935 
1936 /* listen worker: finish in error state */
1937 static void smc_listen_out_err(struct smc_sock *new_smc)
1938 {
1939 	struct sock *newsmcsk = &new_smc->sk;
1940 	struct net *net = sock_net(newsmcsk);
1941 
1942 	this_cpu_inc(net->smc.smc_stats->srv_hshake_err_cnt);
1943 	if (newsmcsk->sk_state == SMC_INIT)
1944 		sock_put(&new_smc->sk); /* passive closing */
1945 	newsmcsk->sk_state = SMC_CLOSED;
1946 
1947 	smc_listen_out(new_smc);
1948 }
1949 
1950 /* listen worker: decline and fall back if possible */
1951 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1952 			       int local_first, u8 version)
1953 {
1954 	/* RDMA setup failed, switch back to TCP */
1955 	smc_conn_abort(new_smc, local_first);
1956 	if (reason_code < 0 ||
1957 	    smc_switch_to_fallback(new_smc, reason_code)) {
1958 		/* error, no fallback possible */
1959 		smc_listen_out_err(new_smc);
1960 		return;
1961 	}
1962 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1963 		if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
1964 			smc_listen_out_err(new_smc);
1965 			return;
1966 		}
1967 	}
1968 	smc_listen_out_connected(new_smc);
1969 }
1970 
1971 /* listen worker: version checking */
1972 static int smc_listen_v2_check(struct smc_sock *new_smc,
1973 			       struct smc_clc_msg_proposal *pclc,
1974 			       struct smc_init_info *ini)
1975 {
1976 	struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
1977 	struct smc_clc_v2_extension *pclc_v2_ext;
1978 	int rc = SMC_CLC_DECL_PEERNOSMC;
1979 
1980 	ini->smc_type_v1 = pclc->hdr.typev1;
1981 	ini->smc_type_v2 = pclc->hdr.typev2;
1982 	ini->smcd_version = smcd_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1983 	ini->smcr_version = smcr_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
1984 	if (pclc->hdr.version > SMC_V1) {
1985 		if (smcd_indicated(ini->smc_type_v2))
1986 			ini->smcd_version |= SMC_V2;
1987 		if (smcr_indicated(ini->smc_type_v2))
1988 			ini->smcr_version |= SMC_V2;
1989 	}
1990 	if (!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) {
1991 		rc = SMC_CLC_DECL_PEERNOSMC;
1992 		goto out;
1993 	}
1994 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1995 	if (!pclc_v2_ext) {
1996 		ini->smcd_version &= ~SMC_V2;
1997 		ini->smcr_version &= ~SMC_V2;
1998 		rc = SMC_CLC_DECL_NOV2EXT;
1999 		goto out;
2000 	}
2001 	pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
2002 	if (ini->smcd_version & SMC_V2) {
2003 		if (!smc_ism_is_v2_capable()) {
2004 			ini->smcd_version &= ~SMC_V2;
2005 			rc = SMC_CLC_DECL_NOISM2SUPP;
2006 		} else if (!pclc_smcd_v2_ext) {
2007 			ini->smcd_version &= ~SMC_V2;
2008 			rc = SMC_CLC_DECL_NOV2DEXT;
2009 		} else if (!pclc_v2_ext->hdr.eid_cnt &&
2010 			   !pclc_v2_ext->hdr.flag.seid) {
2011 			ini->smcd_version &= ~SMC_V2;
2012 			rc = SMC_CLC_DECL_NOUEID;
2013 		}
2014 	}
2015 	if (ini->smcr_version & SMC_V2) {
2016 		if (!pclc_v2_ext->hdr.eid_cnt) {
2017 			ini->smcr_version &= ~SMC_V2;
2018 			rc = SMC_CLC_DECL_NOUEID;
2019 		}
2020 	}
2021 
2022 	ini->release_nr = pclc_v2_ext->hdr.flag.release;
2023 	if (pclc_v2_ext->hdr.flag.release > SMC_RELEASE)
2024 		ini->release_nr = SMC_RELEASE;
2025 
2026 out:
2027 	if (!ini->smcd_version && !ini->smcr_version)
2028 		return rc;
2029 
2030 	return 0;
2031 }
2032 
2033 /* listen worker: check prefixes */
2034 static int smc_listen_prfx_check(struct smc_sock *new_smc,
2035 				 struct smc_clc_msg_proposal *pclc)
2036 {
2037 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
2038 	struct socket *newclcsock = new_smc->clcsock;
2039 
2040 	if (pclc->hdr.typev1 == SMC_TYPE_N)
2041 		return 0;
2042 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
2043 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
2044 		return SMC_CLC_DECL_DIFFPREFIX;
2045 
2046 	return 0;
2047 }
2048 
2049 /* listen worker: initialize connection and buffers */
2050 static int smc_listen_rdma_init(struct smc_sock *new_smc,
2051 				struct smc_init_info *ini)
2052 {
2053 	int rc;
2054 
2055 	/* allocate connection / link group */
2056 	rc = smc_conn_create(new_smc, ini);
2057 	if (rc)
2058 		return rc;
2059 
2060 	/* create send buffer and rmb */
2061 	if (smc_buf_create(new_smc, false)) {
2062 		smc_conn_abort(new_smc, ini->first_contact_local);
2063 		return SMC_CLC_DECL_MEM;
2064 	}
2065 
2066 	return 0;
2067 }
2068 
2069 /* listen worker: initialize connection and buffers for SMC-D */
2070 static int smc_listen_ism_init(struct smc_sock *new_smc,
2071 			       struct smc_init_info *ini)
2072 {
2073 	int rc;
2074 
2075 	rc = smc_conn_create(new_smc, ini);
2076 	if (rc)
2077 		return rc;
2078 
2079 	/* Create send and receive buffers */
2080 	rc = smc_buf_create(new_smc, true);
2081 	if (rc) {
2082 		smc_conn_abort(new_smc, ini->first_contact_local);
2083 		return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
2084 					 SMC_CLC_DECL_MEM;
2085 	}
2086 
2087 	return 0;
2088 }
2089 
2090 static bool smc_is_already_selected(struct smcd_dev *smcd,
2091 				    struct smc_init_info *ini,
2092 				    int matches)
2093 {
2094 	int i;
2095 
2096 	for (i = 0; i < matches; i++)
2097 		if (smcd == ini->ism_dev[i])
2098 			return true;
2099 
2100 	return false;
2101 }
2102 
2103 /* check for ISM devices matching proposed ISM devices */
2104 static void smc_check_ism_v2_match(struct smc_init_info *ini,
2105 				   u16 proposed_chid, u64 proposed_gid,
2106 				   unsigned int *matches)
2107 {
2108 	struct smcd_dev *smcd;
2109 
2110 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
2111 		if (smcd->going_away)
2112 			continue;
2113 		if (smc_is_already_selected(smcd, ini, *matches))
2114 			continue;
2115 		if (smc_ism_get_chid(smcd) == proposed_chid &&
2116 		    !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
2117 			ini->ism_peer_gid[*matches] = proposed_gid;
2118 			ini->ism_dev[*matches] = smcd;
2119 			(*matches)++;
2120 			break;
2121 		}
2122 	}
2123 }
2124 
2125 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
2126 {
2127 	if (!ini->rc)
2128 		ini->rc = rc;
2129 }
2130 
2131 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
2132 					struct smc_clc_msg_proposal *pclc,
2133 					struct smc_init_info *ini)
2134 {
2135 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
2136 	struct smc_clc_v2_extension *smc_v2_ext;
2137 	struct smc_clc_msg_smcd *pclc_smcd;
2138 	unsigned int matches = 0;
2139 	u8 smcd_version;
2140 	u8 *eid = NULL;
2141 	int i, rc;
2142 
2143 	if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
2144 		goto not_found;
2145 
2146 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
2147 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
2148 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
2149 
2150 	mutex_lock(&smcd_dev_list.mutex);
2151 	if (pclc_smcd->ism.chid)
2152 		/* check for ISM device matching proposed native ISM device */
2153 		smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
2154 				       ntohll(pclc_smcd->ism.gid), &matches);
2155 	for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
2156 		/* check for ISM devices matching proposed non-native ISM
2157 		 * devices
2158 		 */
2159 		smc_check_ism_v2_match(ini,
2160 				       ntohs(smcd_v2_ext->gidchid[i - 1].chid),
2161 				       ntohll(smcd_v2_ext->gidchid[i - 1].gid),
2162 				       &matches);
2163 	}
2164 	mutex_unlock(&smcd_dev_list.mutex);
2165 
2166 	if (!ini->ism_dev[0]) {
2167 		smc_find_ism_store_rc(SMC_CLC_DECL_NOSMCD2DEV, ini);
2168 		goto not_found;
2169 	}
2170 
2171 	smc_ism_get_system_eid(&eid);
2172 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
2173 			       smcd_v2_ext->system_eid, eid))
2174 		goto not_found;
2175 
2176 	/* separate - outside the smcd_dev_list.lock */
2177 	smcd_version = ini->smcd_version;
2178 	for (i = 0; i < matches; i++) {
2179 		ini->smcd_version = SMC_V2;
2180 		ini->is_smcd = true;
2181 		ini->ism_selected = i;
2182 		rc = smc_listen_ism_init(new_smc, ini);
2183 		if (rc) {
2184 			smc_find_ism_store_rc(rc, ini);
2185 			/* try next active ISM device */
2186 			continue;
2187 		}
2188 		return; /* matching and usable V2 ISM device found */
2189 	}
2190 	/* no V2 ISM device could be initialized */
2191 	ini->smcd_version = smcd_version;	/* restore original value */
2192 	ini->negotiated_eid[0] = 0;
2193 
2194 not_found:
2195 	ini->smcd_version &= ~SMC_V2;
2196 	ini->ism_dev[0] = NULL;
2197 	ini->is_smcd = false;
2198 }
2199 
2200 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
2201 					struct smc_clc_msg_proposal *pclc,
2202 					struct smc_init_info *ini)
2203 {
2204 	struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
2205 	int rc = 0;
2206 
2207 	/* check if ISM V1 is available */
2208 	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
2209 		goto not_found;
2210 	ini->is_smcd = true; /* prepare ISM check */
2211 	ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
2212 	rc = smc_find_ism_device(new_smc, ini);
2213 	if (rc)
2214 		goto not_found;
2215 	ini->ism_selected = 0;
2216 	rc = smc_listen_ism_init(new_smc, ini);
2217 	if (!rc)
2218 		return;		/* V1 ISM device found */
2219 
2220 not_found:
2221 	smc_find_ism_store_rc(rc, ini);
2222 	ini->smcd_version &= ~SMC_V1;
2223 	ini->ism_dev[0] = NULL;
2224 	ini->is_smcd = false;
2225 }
2226 
2227 /* listen worker: register buffers */
2228 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
2229 {
2230 	struct smc_connection *conn = &new_smc->conn;
2231 
2232 	if (!local_first) {
2233 		/* reg sendbufs if they were vzalloced */
2234 		if (conn->sndbuf_desc->is_vm) {
2235 			if (smcr_lgr_reg_sndbufs(conn->lnk,
2236 						 conn->sndbuf_desc))
2237 				return SMC_CLC_DECL_ERR_REGBUF;
2238 		}
2239 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
2240 			return SMC_CLC_DECL_ERR_REGBUF;
2241 	}
2242 
2243 	return 0;
2244 }
2245 
2246 static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
2247 					 struct smc_clc_msg_proposal *pclc,
2248 					 struct smc_init_info *ini)
2249 {
2250 	struct smc_clc_v2_extension *smc_v2_ext;
2251 	u8 smcr_version;
2252 	int rc;
2253 
2254 	if (!(ini->smcr_version & SMC_V2) || !smcr_indicated(ini->smc_type_v2))
2255 		goto not_found;
2256 
2257 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
2258 	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL))
2259 		goto not_found;
2260 
2261 	/* prepare RDMA check */
2262 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
2263 	memcpy(ini->peer_gid, smc_v2_ext->roce, SMC_GID_SIZE);
2264 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
2265 	ini->check_smcrv2 = true;
2266 	ini->smcrv2.clc_sk = new_smc->clcsock->sk;
2267 	ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr;
2268 	ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce);
2269 	rc = smc_find_rdma_device(new_smc, ini);
2270 	if (rc) {
2271 		smc_find_ism_store_rc(rc, ini);
2272 		goto not_found;
2273 	}
2274 	if (!ini->smcrv2.uses_gateway)
2275 		memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN);
2276 
2277 	smcr_version = ini->smcr_version;
2278 	ini->smcr_version = SMC_V2;
2279 	rc = smc_listen_rdma_init(new_smc, ini);
2280 	if (!rc) {
2281 		rc = smc_listen_rdma_reg(new_smc, ini->first_contact_local);
2282 		if (rc)
2283 			smc_conn_abort(new_smc, ini->first_contact_local);
2284 	}
2285 	if (!rc)
2286 		return;
2287 	ini->smcr_version = smcr_version;
2288 	smc_find_ism_store_rc(rc, ini);
2289 
2290 not_found:
2291 	ini->smcr_version &= ~SMC_V2;
2292 	ini->smcrv2.ib_dev_v2 = NULL;
2293 	ini->check_smcrv2 = false;
2294 }
2295 
2296 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
2297 					struct smc_clc_msg_proposal *pclc,
2298 					struct smc_init_info *ini)
2299 {
2300 	int rc;
2301 
2302 	if (!(ini->smcr_version & SMC_V1) || !smcr_indicated(ini->smc_type_v1))
2303 		return SMC_CLC_DECL_NOSMCDEV;
2304 
2305 	/* prepare RDMA check */
2306 	memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
2307 	memcpy(ini->peer_gid, pclc->lcl.gid, SMC_GID_SIZE);
2308 	memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
2309 	rc = smc_find_rdma_device(new_smc, ini);
2310 	if (rc) {
2311 		/* no RDMA device found */
2312 		return SMC_CLC_DECL_NOSMCDEV;
2313 	}
2314 	rc = smc_listen_rdma_init(new_smc, ini);
2315 	if (rc)
2316 		return rc;
2317 	return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
2318 }
2319 
2320 /* determine the local device matching to proposal */
2321 static int smc_listen_find_device(struct smc_sock *new_smc,
2322 				  struct smc_clc_msg_proposal *pclc,
2323 				  struct smc_init_info *ini)
2324 {
2325 	int prfx_rc;
2326 
2327 	/* check for ISM device matching V2 proposed device */
2328 	smc_find_ism_v2_device_serv(new_smc, pclc, ini);
2329 	if (ini->ism_dev[0])
2330 		return 0;
2331 
2332 	/* check for matching IP prefix and subnet length (V1) */
2333 	prfx_rc = smc_listen_prfx_check(new_smc, pclc);
2334 	if (prfx_rc)
2335 		smc_find_ism_store_rc(prfx_rc, ini);
2336 
2337 	/* get vlan id from IP device */
2338 	if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
2339 		return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
2340 
2341 	/* check for ISM device matching V1 proposed device */
2342 	if (!prfx_rc)
2343 		smc_find_ism_v1_device_serv(new_smc, pclc, ini);
2344 	if (ini->ism_dev[0])
2345 		return 0;
2346 
2347 	if (!smcr_indicated(pclc->hdr.typev1) &&
2348 	    !smcr_indicated(pclc->hdr.typev2))
2349 		/* skip RDMA and decline */
2350 		return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
2351 
2352 	/* check if RDMA V2 is available */
2353 	smc_find_rdma_v2_device_serv(new_smc, pclc, ini);
2354 	if (ini->smcrv2.ib_dev_v2)
2355 		return 0;
2356 
2357 	/* check if RDMA V1 is available */
2358 	if (!prfx_rc) {
2359 		int rc;
2360 
2361 		rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
2362 		smc_find_ism_store_rc(rc, ini);
2363 		return (!rc) ? 0 : ini->rc;
2364 	}
2365 	return prfx_rc;
2366 }
2367 
2368 /* listen worker: finish RDMA setup */
2369 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
2370 				  struct smc_clc_msg_accept_confirm *cclc,
2371 				  bool local_first,
2372 				  struct smc_init_info *ini)
2373 {
2374 	struct smc_link *link = new_smc->conn.lnk;
2375 	int reason_code = 0;
2376 
2377 	if (local_first)
2378 		smc_link_save_peer_info(link, cclc, ini);
2379 
2380 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
2381 		return SMC_CLC_DECL_ERR_RTOK;
2382 
2383 	if (local_first) {
2384 		if (smc_ib_ready_link(link))
2385 			return SMC_CLC_DECL_ERR_RDYLNK;
2386 		/* QP confirmation over RoCE fabric */
2387 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
2388 		reason_code = smcr_serv_conf_first_link(new_smc);
2389 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
2390 	}
2391 	return reason_code;
2392 }
2393 
2394 /* setup for connection of server */
2395 static void smc_listen_work(struct work_struct *work)
2396 {
2397 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
2398 						smc_listen_work);
2399 	struct socket *newclcsock = new_smc->clcsock;
2400 	struct smc_clc_msg_accept_confirm *cclc;
2401 	struct smc_clc_msg_proposal_area *buf;
2402 	struct smc_clc_msg_proposal *pclc;
2403 	struct smc_init_info *ini = NULL;
2404 	u8 proposal_version = SMC_V1;
2405 	u8 accept_version;
2406 	int rc = 0;
2407 
2408 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
2409 		return smc_listen_out_err(new_smc);
2410 
2411 	if (new_smc->use_fallback) {
2412 		smc_listen_out_connected(new_smc);
2413 		return;
2414 	}
2415 
2416 	/* check if peer is smc capable */
2417 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
2418 		rc = smc_switch_to_fallback(new_smc, SMC_CLC_DECL_PEERNOSMC);
2419 		if (rc)
2420 			smc_listen_out_err(new_smc);
2421 		else
2422 			smc_listen_out_connected(new_smc);
2423 		return;
2424 	}
2425 
2426 	/* do inband token exchange -
2427 	 * wait for and receive SMC Proposal CLC message
2428 	 */
2429 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
2430 	if (!buf) {
2431 		rc = SMC_CLC_DECL_MEM;
2432 		goto out_decl;
2433 	}
2434 	pclc = (struct smc_clc_msg_proposal *)buf;
2435 	rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
2436 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
2437 	if (rc)
2438 		goto out_decl;
2439 
2440 	if (pclc->hdr.version > SMC_V1)
2441 		proposal_version = SMC_V2;
2442 
2443 	/* IPSec connections opt out of SMC optimizations */
2444 	if (using_ipsec(new_smc)) {
2445 		rc = SMC_CLC_DECL_IPSEC;
2446 		goto out_decl;
2447 	}
2448 
2449 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
2450 	if (!ini) {
2451 		rc = SMC_CLC_DECL_MEM;
2452 		goto out_decl;
2453 	}
2454 
2455 	/* initial version checking */
2456 	rc = smc_listen_v2_check(new_smc, pclc, ini);
2457 	if (rc)
2458 		goto out_decl;
2459 
2460 	rc = smc_clc_srv_v2x_features_validate(pclc, ini);
2461 	if (rc)
2462 		goto out_decl;
2463 
2464 	mutex_lock(&smc_server_lgr_pending);
2465 	smc_close_init(new_smc);
2466 	smc_rx_init(new_smc);
2467 	smc_tx_init(new_smc);
2468 
2469 	/* determine ISM or RoCE device used for connection */
2470 	rc = smc_listen_find_device(new_smc, pclc, ini);
2471 	if (rc)
2472 		goto out_unlock;
2473 
2474 	/* send SMC Accept CLC message */
2475 	accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version;
2476 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
2477 				 accept_version, ini->negotiated_eid, ini);
2478 	if (rc)
2479 		goto out_unlock;
2480 
2481 	/* SMC-D does not need this lock any more */
2482 	if (ini->is_smcd)
2483 		mutex_unlock(&smc_server_lgr_pending);
2484 
2485 	/* receive SMC Confirm CLC message */
2486 	memset(buf, 0, sizeof(*buf));
2487 	cclc = (struct smc_clc_msg_accept_confirm *)buf;
2488 	rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
2489 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
2490 	if (rc) {
2491 		if (!ini->is_smcd)
2492 			goto out_unlock;
2493 		goto out_decl;
2494 	}
2495 
2496 	rc = smc_clc_v2x_features_confirm_check(cclc, ini);
2497 	if (rc) {
2498 		if (!ini->is_smcd)
2499 			goto out_unlock;
2500 		goto out_decl;
2501 	}
2502 
2503 	/* fce smc release version is needed in smc_listen_rdma_finish,
2504 	 * so save fce info here.
2505 	 */
2506 	smc_conn_save_peer_info_fce(new_smc, cclc);
2507 
2508 	/* finish worker */
2509 	if (!ini->is_smcd) {
2510 		rc = smc_listen_rdma_finish(new_smc, cclc,
2511 					    ini->first_contact_local, ini);
2512 		if (rc)
2513 			goto out_unlock;
2514 		mutex_unlock(&smc_server_lgr_pending);
2515 	}
2516 	smc_conn_save_peer_info(new_smc, cclc);
2517 	smc_listen_out_connected(new_smc);
2518 	SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
2519 	goto out_free;
2520 
2521 out_unlock:
2522 	mutex_unlock(&smc_server_lgr_pending);
2523 out_decl:
2524 	smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
2525 			   proposal_version);
2526 out_free:
2527 	kfree(ini);
2528 	kfree(buf);
2529 }
2530 
2531 static void smc_tcp_listen_work(struct work_struct *work)
2532 {
2533 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
2534 					     tcp_listen_work);
2535 	struct sock *lsk = &lsmc->sk;
2536 	struct smc_sock *new_smc;
2537 	int rc = 0;
2538 
2539 	lock_sock(lsk);
2540 	while (lsk->sk_state == SMC_LISTEN) {
2541 		rc = smc_clcsock_accept(lsmc, &new_smc);
2542 		if (rc) /* clcsock accept queue empty or error */
2543 			goto out;
2544 		if (!new_smc)
2545 			continue;
2546 
2547 		if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
2548 			atomic_inc(&lsmc->queued_smc_hs);
2549 
2550 		new_smc->listen_smc = lsmc;
2551 		new_smc->use_fallback = lsmc->use_fallback;
2552 		new_smc->fallback_rsn = lsmc->fallback_rsn;
2553 		sock_hold(lsk); /* sock_put in smc_listen_work */
2554 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
2555 		smc_copy_sock_settings_to_smc(new_smc);
2556 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
2557 		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
2558 			sock_put(&new_smc->sk);
2559 	}
2560 
2561 out:
2562 	release_sock(lsk);
2563 	sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
2564 }
2565 
2566 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
2567 {
2568 	struct smc_sock *lsmc;
2569 
2570 	read_lock_bh(&listen_clcsock->sk_callback_lock);
2571 	lsmc = smc_clcsock_user_data(listen_clcsock);
2572 	if (!lsmc)
2573 		goto out;
2574 	lsmc->clcsk_data_ready(listen_clcsock);
2575 	if (lsmc->sk.sk_state == SMC_LISTEN) {
2576 		sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
2577 		if (!queue_work(smc_tcp_ls_wq, &lsmc->tcp_listen_work))
2578 			sock_put(&lsmc->sk);
2579 	}
2580 out:
2581 	read_unlock_bh(&listen_clcsock->sk_callback_lock);
2582 }
2583 
2584 static int smc_listen(struct socket *sock, int backlog)
2585 {
2586 	struct sock *sk = sock->sk;
2587 	struct smc_sock *smc;
2588 	int rc;
2589 
2590 	smc = smc_sk(sk);
2591 	lock_sock(sk);
2592 
2593 	rc = -EINVAL;
2594 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
2595 	    smc->connect_nonblock || sock->state != SS_UNCONNECTED)
2596 		goto out;
2597 
2598 	rc = 0;
2599 	if (sk->sk_state == SMC_LISTEN) {
2600 		sk->sk_max_ack_backlog = backlog;
2601 		goto out;
2602 	}
2603 	/* some socket options are handled in core, so we could not apply
2604 	 * them to the clc socket -- copy smc socket options to clc socket
2605 	 */
2606 	smc_copy_sock_settings_to_clc(smc);
2607 	if (!smc->use_fallback)
2608 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
2609 
2610 	/* save original sk_data_ready function and establish
2611 	 * smc-specific sk_data_ready function
2612 	 */
2613 	write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
2614 	smc->clcsock->sk->sk_user_data =
2615 		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
2616 	smc_clcsock_replace_cb(&smc->clcsock->sk->sk_data_ready,
2617 			       smc_clcsock_data_ready, &smc->clcsk_data_ready);
2618 	write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
2619 
2620 	/* save original ops */
2621 	smc->ori_af_ops = inet_csk(smc->clcsock->sk)->icsk_af_ops;
2622 
2623 	smc->af_ops = *smc->ori_af_ops;
2624 	smc->af_ops.syn_recv_sock = smc_tcp_syn_recv_sock;
2625 
2626 	inet_csk(smc->clcsock->sk)->icsk_af_ops = &smc->af_ops;
2627 
2628 	if (smc->limit_smc_hs)
2629 		tcp_sk(smc->clcsock->sk)->smc_hs_congested = smc_hs_congested;
2630 
2631 	rc = kernel_listen(smc->clcsock, backlog);
2632 	if (rc) {
2633 		write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
2634 		smc_clcsock_restore_cb(&smc->clcsock->sk->sk_data_ready,
2635 				       &smc->clcsk_data_ready);
2636 		smc->clcsock->sk->sk_user_data = NULL;
2637 		write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
2638 		goto out;
2639 	}
2640 	sk->sk_max_ack_backlog = backlog;
2641 	sk->sk_ack_backlog = 0;
2642 	sk->sk_state = SMC_LISTEN;
2643 
2644 out:
2645 	release_sock(sk);
2646 	return rc;
2647 }
2648 
2649 static int smc_accept(struct socket *sock, struct socket *new_sock,
2650 		      int flags, bool kern)
2651 {
2652 	struct sock *sk = sock->sk, *nsk;
2653 	DECLARE_WAITQUEUE(wait, current);
2654 	struct smc_sock *lsmc;
2655 	long timeo;
2656 	int rc = 0;
2657 
2658 	lsmc = smc_sk(sk);
2659 	sock_hold(sk); /* sock_put below */
2660 	lock_sock(sk);
2661 
2662 	if (lsmc->sk.sk_state != SMC_LISTEN) {
2663 		rc = -EINVAL;
2664 		release_sock(sk);
2665 		goto out;
2666 	}
2667 
2668 	/* Wait for an incoming connection */
2669 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
2670 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
2671 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
2672 		set_current_state(TASK_INTERRUPTIBLE);
2673 		if (!timeo) {
2674 			rc = -EAGAIN;
2675 			break;
2676 		}
2677 		release_sock(sk);
2678 		timeo = schedule_timeout(timeo);
2679 		/* wakeup by sk_data_ready in smc_listen_work() */
2680 		sched_annotate_sleep();
2681 		lock_sock(sk);
2682 		if (signal_pending(current)) {
2683 			rc = sock_intr_errno(timeo);
2684 			break;
2685 		}
2686 	}
2687 	set_current_state(TASK_RUNNING);
2688 	remove_wait_queue(sk_sleep(sk), &wait);
2689 
2690 	if (!rc)
2691 		rc = sock_error(nsk);
2692 	release_sock(sk);
2693 	if (rc)
2694 		goto out;
2695 
2696 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
2697 		/* wait till data arrives on the socket */
2698 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
2699 								MSEC_PER_SEC);
2700 		if (smc_sk(nsk)->use_fallback) {
2701 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
2702 
2703 			lock_sock(clcsk);
2704 			if (skb_queue_empty(&clcsk->sk_receive_queue))
2705 				sk_wait_data(clcsk, &timeo, NULL);
2706 			release_sock(clcsk);
2707 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
2708 			lock_sock(nsk);
2709 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
2710 			release_sock(nsk);
2711 		}
2712 	}
2713 
2714 out:
2715 	sock_put(sk); /* sock_hold above */
2716 	return rc;
2717 }
2718 
2719 static int smc_getname(struct socket *sock, struct sockaddr *addr,
2720 		       int peer)
2721 {
2722 	struct smc_sock *smc;
2723 
2724 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
2725 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
2726 		return -ENOTCONN;
2727 
2728 	smc = smc_sk(sock->sk);
2729 
2730 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
2731 }
2732 
2733 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2734 {
2735 	struct sock *sk = sock->sk;
2736 	struct smc_sock *smc;
2737 	int rc;
2738 
2739 	smc = smc_sk(sk);
2740 	lock_sock(sk);
2741 
2742 	/* SMC does not support connect with fastopen */
2743 	if (msg->msg_flags & MSG_FASTOPEN) {
2744 		/* not connected yet, fallback */
2745 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2746 			rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
2747 			if (rc)
2748 				goto out;
2749 		} else {
2750 			rc = -EINVAL;
2751 			goto out;
2752 		}
2753 	} else if ((sk->sk_state != SMC_ACTIVE) &&
2754 		   (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2755 		   (sk->sk_state != SMC_INIT)) {
2756 		rc = -EPIPE;
2757 		goto out;
2758 	}
2759 
2760 	if (smc->use_fallback) {
2761 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
2762 	} else {
2763 		rc = smc_tx_sendmsg(smc, msg, len);
2764 		SMC_STAT_TX_PAYLOAD(smc, len, rc);
2765 	}
2766 out:
2767 	release_sock(sk);
2768 	return rc;
2769 }
2770 
2771 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2772 		       int flags)
2773 {
2774 	struct sock *sk = sock->sk;
2775 	struct smc_sock *smc;
2776 	int rc = -ENOTCONN;
2777 
2778 	smc = smc_sk(sk);
2779 	lock_sock(sk);
2780 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2781 		/* socket was connected before, no more data to read */
2782 		rc = 0;
2783 		goto out;
2784 	}
2785 	if ((sk->sk_state == SMC_INIT) ||
2786 	    (sk->sk_state == SMC_LISTEN) ||
2787 	    (sk->sk_state == SMC_CLOSED))
2788 		goto out;
2789 
2790 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2791 		rc = 0;
2792 		goto out;
2793 	}
2794 
2795 	if (smc->use_fallback) {
2796 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
2797 	} else {
2798 		msg->msg_namelen = 0;
2799 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
2800 		SMC_STAT_RX_PAYLOAD(smc, rc, rc);
2801 	}
2802 
2803 out:
2804 	release_sock(sk);
2805 	return rc;
2806 }
2807 
2808 static __poll_t smc_accept_poll(struct sock *parent)
2809 {
2810 	struct smc_sock *isk = smc_sk(parent);
2811 	__poll_t mask = 0;
2812 
2813 	spin_lock(&isk->accept_q_lock);
2814 	if (!list_empty(&isk->accept_q))
2815 		mask = EPOLLIN | EPOLLRDNORM;
2816 	spin_unlock(&isk->accept_q_lock);
2817 
2818 	return mask;
2819 }
2820 
2821 static __poll_t smc_poll(struct file *file, struct socket *sock,
2822 			     poll_table *wait)
2823 {
2824 	struct sock *sk = sock->sk;
2825 	struct smc_sock *smc;
2826 	__poll_t mask = 0;
2827 
2828 	if (!sk)
2829 		return EPOLLNVAL;
2830 
2831 	smc = smc_sk(sock->sk);
2832 	if (smc->use_fallback) {
2833 		/* delegate to CLC child sock */
2834 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
2835 		sk->sk_err = smc->clcsock->sk->sk_err;
2836 	} else {
2837 		if (sk->sk_state != SMC_CLOSED)
2838 			sock_poll_wait(file, sock, wait);
2839 		if (sk->sk_err)
2840 			mask |= EPOLLERR;
2841 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
2842 		    (sk->sk_state == SMC_CLOSED))
2843 			mask |= EPOLLHUP;
2844 		if (sk->sk_state == SMC_LISTEN) {
2845 			/* woken up by sk_data_ready in smc_listen_work() */
2846 			mask |= smc_accept_poll(sk);
2847 		} else if (smc->use_fallback) { /* as result of connect_work()*/
2848 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
2849 							   wait);
2850 			sk->sk_err = smc->clcsock->sk->sk_err;
2851 		} else {
2852 			if ((sk->sk_state != SMC_INIT &&
2853 			     atomic_read(&smc->conn.sndbuf_space)) ||
2854 			    sk->sk_shutdown & SEND_SHUTDOWN) {
2855 				mask |= EPOLLOUT | EPOLLWRNORM;
2856 			} else {
2857 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2858 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2859 			}
2860 			if (atomic_read(&smc->conn.bytes_to_rcv))
2861 				mask |= EPOLLIN | EPOLLRDNORM;
2862 			if (sk->sk_shutdown & RCV_SHUTDOWN)
2863 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
2864 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
2865 				mask |= EPOLLIN;
2866 			if (smc->conn.urg_state == SMC_URG_VALID)
2867 				mask |= EPOLLPRI;
2868 		}
2869 	}
2870 
2871 	return mask;
2872 }
2873 
2874 static int smc_shutdown(struct socket *sock, int how)
2875 {
2876 	struct sock *sk = sock->sk;
2877 	bool do_shutdown = true;
2878 	struct smc_sock *smc;
2879 	int rc = -EINVAL;
2880 	int old_state;
2881 	int rc1 = 0;
2882 
2883 	smc = smc_sk(sk);
2884 
2885 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
2886 		return rc;
2887 
2888 	lock_sock(sk);
2889 
2890 	if (sock->state == SS_CONNECTING) {
2891 		if (sk->sk_state == SMC_ACTIVE)
2892 			sock->state = SS_CONNECTED;
2893 		else if (sk->sk_state == SMC_PEERCLOSEWAIT1 ||
2894 			 sk->sk_state == SMC_PEERCLOSEWAIT2 ||
2895 			 sk->sk_state == SMC_APPCLOSEWAIT1 ||
2896 			 sk->sk_state == SMC_APPCLOSEWAIT2 ||
2897 			 sk->sk_state == SMC_APPFINCLOSEWAIT)
2898 			sock->state = SS_DISCONNECTING;
2899 	}
2900 
2901 	rc = -ENOTCONN;
2902 	if ((sk->sk_state != SMC_ACTIVE) &&
2903 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
2904 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
2905 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2906 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
2907 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
2908 		goto out;
2909 	if (smc->use_fallback) {
2910 		rc = kernel_sock_shutdown(smc->clcsock, how);
2911 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
2912 		if (sk->sk_shutdown == SHUTDOWN_MASK) {
2913 			sk->sk_state = SMC_CLOSED;
2914 			sk->sk_socket->state = SS_UNCONNECTED;
2915 			sock_put(sk);
2916 		}
2917 		goto out;
2918 	}
2919 	switch (how) {
2920 	case SHUT_RDWR:		/* shutdown in both directions */
2921 		old_state = sk->sk_state;
2922 		rc = smc_close_active(smc);
2923 		if (old_state == SMC_ACTIVE &&
2924 		    sk->sk_state == SMC_PEERCLOSEWAIT1)
2925 			do_shutdown = false;
2926 		break;
2927 	case SHUT_WR:
2928 		rc = smc_close_shutdown_write(smc);
2929 		break;
2930 	case SHUT_RD:
2931 		rc = 0;
2932 		/* nothing more to do because peer is not involved */
2933 		break;
2934 	}
2935 	if (do_shutdown && smc->clcsock)
2936 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
2937 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
2938 	sk->sk_shutdown |= how + 1;
2939 
2940 	if (sk->sk_state == SMC_CLOSED)
2941 		sock->state = SS_UNCONNECTED;
2942 	else
2943 		sock->state = SS_DISCONNECTING;
2944 out:
2945 	release_sock(sk);
2946 	return rc ? rc : rc1;
2947 }
2948 
2949 static int __smc_getsockopt(struct socket *sock, int level, int optname,
2950 			    char __user *optval, int __user *optlen)
2951 {
2952 	struct smc_sock *smc;
2953 	int val, len;
2954 
2955 	smc = smc_sk(sock->sk);
2956 
2957 	if (get_user(len, optlen))
2958 		return -EFAULT;
2959 
2960 	len = min_t(int, len, sizeof(int));
2961 
2962 	if (len < 0)
2963 		return -EINVAL;
2964 
2965 	switch (optname) {
2966 	case SMC_LIMIT_HS:
2967 		val = smc->limit_smc_hs;
2968 		break;
2969 	default:
2970 		return -EOPNOTSUPP;
2971 	}
2972 
2973 	if (put_user(len, optlen))
2974 		return -EFAULT;
2975 	if (copy_to_user(optval, &val, len))
2976 		return -EFAULT;
2977 
2978 	return 0;
2979 }
2980 
2981 static int __smc_setsockopt(struct socket *sock, int level, int optname,
2982 			    sockptr_t optval, unsigned int optlen)
2983 {
2984 	struct sock *sk = sock->sk;
2985 	struct smc_sock *smc;
2986 	int val, rc;
2987 
2988 	smc = smc_sk(sk);
2989 
2990 	lock_sock(sk);
2991 	switch (optname) {
2992 	case SMC_LIMIT_HS:
2993 		if (optlen < sizeof(int)) {
2994 			rc = -EINVAL;
2995 			break;
2996 		}
2997 		if (copy_from_sockptr(&val, optval, sizeof(int))) {
2998 			rc = -EFAULT;
2999 			break;
3000 		}
3001 
3002 		smc->limit_smc_hs = !!val;
3003 		rc = 0;
3004 		break;
3005 	default:
3006 		rc = -EOPNOTSUPP;
3007 		break;
3008 	}
3009 	release_sock(sk);
3010 
3011 	return rc;
3012 }
3013 
3014 static int smc_setsockopt(struct socket *sock, int level, int optname,
3015 			  sockptr_t optval, unsigned int optlen)
3016 {
3017 	struct sock *sk = sock->sk;
3018 	struct smc_sock *smc;
3019 	int val, rc;
3020 
3021 	if (level == SOL_TCP && optname == TCP_ULP)
3022 		return -EOPNOTSUPP;
3023 	else if (level == SOL_SMC)
3024 		return __smc_setsockopt(sock, level, optname, optval, optlen);
3025 
3026 	smc = smc_sk(sk);
3027 
3028 	/* generic setsockopts reaching us here always apply to the
3029 	 * CLC socket
3030 	 */
3031 	mutex_lock(&smc->clcsock_release_lock);
3032 	if (!smc->clcsock) {
3033 		mutex_unlock(&smc->clcsock_release_lock);
3034 		return -EBADF;
3035 	}
3036 	if (unlikely(!smc->clcsock->ops->setsockopt))
3037 		rc = -EOPNOTSUPP;
3038 	else
3039 		rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
3040 						   optval, optlen);
3041 	if (smc->clcsock->sk->sk_err) {
3042 		sk->sk_err = smc->clcsock->sk->sk_err;
3043 		sk_error_report(sk);
3044 	}
3045 	mutex_unlock(&smc->clcsock_release_lock);
3046 
3047 	if (optlen < sizeof(int))
3048 		return -EINVAL;
3049 	if (copy_from_sockptr(&val, optval, sizeof(int)))
3050 		return -EFAULT;
3051 
3052 	lock_sock(sk);
3053 	if (rc || smc->use_fallback)
3054 		goto out;
3055 	switch (optname) {
3056 	case TCP_FASTOPEN:
3057 	case TCP_FASTOPEN_CONNECT:
3058 	case TCP_FASTOPEN_KEY:
3059 	case TCP_FASTOPEN_NO_COOKIE:
3060 		/* option not supported by SMC */
3061 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
3062 			rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
3063 		} else {
3064 			rc = -EINVAL;
3065 		}
3066 		break;
3067 	case TCP_NODELAY:
3068 		if (sk->sk_state != SMC_INIT &&
3069 		    sk->sk_state != SMC_LISTEN &&
3070 		    sk->sk_state != SMC_CLOSED) {
3071 			if (val) {
3072 				SMC_STAT_INC(smc, ndly_cnt);
3073 				smc_tx_pending(&smc->conn);
3074 				cancel_delayed_work(&smc->conn.tx_work);
3075 			}
3076 		}
3077 		break;
3078 	case TCP_CORK:
3079 		if (sk->sk_state != SMC_INIT &&
3080 		    sk->sk_state != SMC_LISTEN &&
3081 		    sk->sk_state != SMC_CLOSED) {
3082 			if (!val) {
3083 				SMC_STAT_INC(smc, cork_cnt);
3084 				smc_tx_pending(&smc->conn);
3085 				cancel_delayed_work(&smc->conn.tx_work);
3086 			}
3087 		}
3088 		break;
3089 	case TCP_DEFER_ACCEPT:
3090 		smc->sockopt_defer_accept = val;
3091 		break;
3092 	default:
3093 		break;
3094 	}
3095 out:
3096 	release_sock(sk);
3097 
3098 	return rc;
3099 }
3100 
3101 static int smc_getsockopt(struct socket *sock, int level, int optname,
3102 			  char __user *optval, int __user *optlen)
3103 {
3104 	struct smc_sock *smc;
3105 	int rc;
3106 
3107 	if (level == SOL_SMC)
3108 		return __smc_getsockopt(sock, level, optname, optval, optlen);
3109 
3110 	smc = smc_sk(sock->sk);
3111 	mutex_lock(&smc->clcsock_release_lock);
3112 	if (!smc->clcsock) {
3113 		mutex_unlock(&smc->clcsock_release_lock);
3114 		return -EBADF;
3115 	}
3116 	/* socket options apply to the CLC socket */
3117 	if (unlikely(!smc->clcsock->ops->getsockopt)) {
3118 		mutex_unlock(&smc->clcsock_release_lock);
3119 		return -EOPNOTSUPP;
3120 	}
3121 	rc = smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
3122 					   optval, optlen);
3123 	mutex_unlock(&smc->clcsock_release_lock);
3124 	return rc;
3125 }
3126 
3127 static int smc_ioctl(struct socket *sock, unsigned int cmd,
3128 		     unsigned long arg)
3129 {
3130 	union smc_host_cursor cons, urg;
3131 	struct smc_connection *conn;
3132 	struct smc_sock *smc;
3133 	int answ;
3134 
3135 	smc = smc_sk(sock->sk);
3136 	conn = &smc->conn;
3137 	lock_sock(&smc->sk);
3138 	if (smc->use_fallback) {
3139 		if (!smc->clcsock) {
3140 			release_sock(&smc->sk);
3141 			return -EBADF;
3142 		}
3143 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
3144 		release_sock(&smc->sk);
3145 		return answ;
3146 	}
3147 	switch (cmd) {
3148 	case SIOCINQ: /* same as FIONREAD */
3149 		if (smc->sk.sk_state == SMC_LISTEN) {
3150 			release_sock(&smc->sk);
3151 			return -EINVAL;
3152 		}
3153 		if (smc->sk.sk_state == SMC_INIT ||
3154 		    smc->sk.sk_state == SMC_CLOSED)
3155 			answ = 0;
3156 		else
3157 			answ = atomic_read(&smc->conn.bytes_to_rcv);
3158 		break;
3159 	case SIOCOUTQ:
3160 		/* output queue size (not send + not acked) */
3161 		if (smc->sk.sk_state == SMC_LISTEN) {
3162 			release_sock(&smc->sk);
3163 			return -EINVAL;
3164 		}
3165 		if (smc->sk.sk_state == SMC_INIT ||
3166 		    smc->sk.sk_state == SMC_CLOSED)
3167 			answ = 0;
3168 		else
3169 			answ = smc->conn.sndbuf_desc->len -
3170 					atomic_read(&smc->conn.sndbuf_space);
3171 		break;
3172 	case SIOCOUTQNSD:
3173 		/* output queue size (not send only) */
3174 		if (smc->sk.sk_state == SMC_LISTEN) {
3175 			release_sock(&smc->sk);
3176 			return -EINVAL;
3177 		}
3178 		if (smc->sk.sk_state == SMC_INIT ||
3179 		    smc->sk.sk_state == SMC_CLOSED)
3180 			answ = 0;
3181 		else
3182 			answ = smc_tx_prepared_sends(&smc->conn);
3183 		break;
3184 	case SIOCATMARK:
3185 		if (smc->sk.sk_state == SMC_LISTEN) {
3186 			release_sock(&smc->sk);
3187 			return -EINVAL;
3188 		}
3189 		if (smc->sk.sk_state == SMC_INIT ||
3190 		    smc->sk.sk_state == SMC_CLOSED) {
3191 			answ = 0;
3192 		} else {
3193 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
3194 			smc_curs_copy(&urg, &conn->urg_curs, conn);
3195 			answ = smc_curs_diff(conn->rmb_desc->len,
3196 					     &cons, &urg) == 1;
3197 		}
3198 		break;
3199 	default:
3200 		release_sock(&smc->sk);
3201 		return -ENOIOCTLCMD;
3202 	}
3203 	release_sock(&smc->sk);
3204 
3205 	return put_user(answ, (int __user *)arg);
3206 }
3207 
3208 /* Map the affected portions of the rmbe into an spd, note the number of bytes
3209  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
3210  * updates till whenever a respective page has been fully processed.
3211  * Note that subsequent recv() calls have to wait till all splice() processing
3212  * completed.
3213  */
3214 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
3215 			       struct pipe_inode_info *pipe, size_t len,
3216 			       unsigned int flags)
3217 {
3218 	struct sock *sk = sock->sk;
3219 	struct smc_sock *smc;
3220 	int rc = -ENOTCONN;
3221 
3222 	smc = smc_sk(sk);
3223 	lock_sock(sk);
3224 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
3225 		/* socket was connected before, no more data to read */
3226 		rc = 0;
3227 		goto out;
3228 	}
3229 	if (sk->sk_state == SMC_INIT ||
3230 	    sk->sk_state == SMC_LISTEN ||
3231 	    sk->sk_state == SMC_CLOSED)
3232 		goto out;
3233 
3234 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
3235 		rc = 0;
3236 		goto out;
3237 	}
3238 
3239 	if (smc->use_fallback) {
3240 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
3241 						    pipe, len, flags);
3242 	} else {
3243 		if (*ppos) {
3244 			rc = -ESPIPE;
3245 			goto out;
3246 		}
3247 		if (flags & SPLICE_F_NONBLOCK)
3248 			flags = MSG_DONTWAIT;
3249 		else
3250 			flags = 0;
3251 		SMC_STAT_INC(smc, splice_cnt);
3252 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
3253 	}
3254 out:
3255 	release_sock(sk);
3256 
3257 	return rc;
3258 }
3259 
3260 /* must look like tcp */
3261 static const struct proto_ops smc_sock_ops = {
3262 	.family		= PF_SMC,
3263 	.owner		= THIS_MODULE,
3264 	.release	= smc_release,
3265 	.bind		= smc_bind,
3266 	.connect	= smc_connect,
3267 	.socketpair	= sock_no_socketpair,
3268 	.accept		= smc_accept,
3269 	.getname	= smc_getname,
3270 	.poll		= smc_poll,
3271 	.ioctl		= smc_ioctl,
3272 	.listen		= smc_listen,
3273 	.shutdown	= smc_shutdown,
3274 	.setsockopt	= smc_setsockopt,
3275 	.getsockopt	= smc_getsockopt,
3276 	.sendmsg	= smc_sendmsg,
3277 	.recvmsg	= smc_recvmsg,
3278 	.mmap		= sock_no_mmap,
3279 	.splice_read	= smc_splice_read,
3280 };
3281 
3282 static int __smc_create(struct net *net, struct socket *sock, int protocol,
3283 			int kern, struct socket *clcsock)
3284 {
3285 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
3286 	struct smc_sock *smc;
3287 	struct sock *sk;
3288 	int rc;
3289 
3290 	rc = -ESOCKTNOSUPPORT;
3291 	if (sock->type != SOCK_STREAM)
3292 		goto out;
3293 
3294 	rc = -EPROTONOSUPPORT;
3295 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
3296 		goto out;
3297 
3298 	rc = -ENOBUFS;
3299 	sock->ops = &smc_sock_ops;
3300 	sock->state = SS_UNCONNECTED;
3301 	sk = smc_sock_alloc(net, sock, protocol);
3302 	if (!sk)
3303 		goto out;
3304 
3305 	/* create internal TCP socket for CLC handshake and fallback */
3306 	smc = smc_sk(sk);
3307 	smc->use_fallback = false; /* assume rdma capability first */
3308 	smc->fallback_rsn = 0;
3309 
3310 	/* default behavior from limit_smc_hs in every net namespace */
3311 	smc->limit_smc_hs = net->smc.limit_smc_hs;
3312 
3313 	rc = 0;
3314 	if (!clcsock) {
3315 		rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
3316 				      &smc->clcsock);
3317 		if (rc) {
3318 			sk_common_release(sk);
3319 			goto out;
3320 		}
3321 
3322 		/* smc_clcsock_release() does not wait smc->clcsock->sk's
3323 		 * destruction;  its sk_state might not be TCP_CLOSE after
3324 		 * smc->sk is close()d, and TCP timers can be fired later,
3325 		 * which need net ref.
3326 		 */
3327 		sk = smc->clcsock->sk;
3328 		__netns_tracker_free(net, &sk->ns_tracker, false);
3329 		sk->sk_net_refcnt = 1;
3330 		get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
3331 		sock_inuse_add(net, 1);
3332 	} else {
3333 		smc->clcsock = clcsock;
3334 	}
3335 
3336 out:
3337 	return rc;
3338 }
3339 
3340 static int smc_create(struct net *net, struct socket *sock, int protocol,
3341 		      int kern)
3342 {
3343 	return __smc_create(net, sock, protocol, kern, NULL);
3344 }
3345 
3346 static const struct net_proto_family smc_sock_family_ops = {
3347 	.family	= PF_SMC,
3348 	.owner	= THIS_MODULE,
3349 	.create	= smc_create,
3350 };
3351 
3352 static int smc_ulp_init(struct sock *sk)
3353 {
3354 	struct socket *tcp = sk->sk_socket;
3355 	struct net *net = sock_net(sk);
3356 	struct socket *smcsock;
3357 	int protocol, ret;
3358 
3359 	/* only TCP can be replaced */
3360 	if (tcp->type != SOCK_STREAM || sk->sk_protocol != IPPROTO_TCP ||
3361 	    (sk->sk_family != AF_INET && sk->sk_family != AF_INET6))
3362 		return -ESOCKTNOSUPPORT;
3363 	/* don't handle wq now */
3364 	if (tcp->state != SS_UNCONNECTED || !tcp->file || tcp->wq.fasync_list)
3365 		return -ENOTCONN;
3366 
3367 	if (sk->sk_family == AF_INET)
3368 		protocol = SMCPROTO_SMC;
3369 	else
3370 		protocol = SMCPROTO_SMC6;
3371 
3372 	smcsock = sock_alloc();
3373 	if (!smcsock)
3374 		return -ENFILE;
3375 
3376 	smcsock->type = SOCK_STREAM;
3377 	__module_get(THIS_MODULE); /* tried in __tcp_ulp_find_autoload */
3378 	ret = __smc_create(net, smcsock, protocol, 1, tcp);
3379 	if (ret) {
3380 		sock_release(smcsock); /* module_put() which ops won't be NULL */
3381 		return ret;
3382 	}
3383 
3384 	/* replace tcp socket to smc */
3385 	smcsock->file = tcp->file;
3386 	smcsock->file->private_data = smcsock;
3387 	smcsock->file->f_inode = SOCK_INODE(smcsock); /* replace inode when sock_close */
3388 	smcsock->file->f_path.dentry->d_inode = SOCK_INODE(smcsock); /* dput() in __fput */
3389 	tcp->file = NULL;
3390 
3391 	return ret;
3392 }
3393 
3394 static void smc_ulp_clone(const struct request_sock *req, struct sock *newsk,
3395 			  const gfp_t priority)
3396 {
3397 	struct inet_connection_sock *icsk = inet_csk(newsk);
3398 
3399 	/* don't inherit ulp ops to child when listen */
3400 	icsk->icsk_ulp_ops = NULL;
3401 }
3402 
3403 static struct tcp_ulp_ops smc_ulp_ops __read_mostly = {
3404 	.name		= "smc",
3405 	.owner		= THIS_MODULE,
3406 	.init		= smc_ulp_init,
3407 	.clone		= smc_ulp_clone,
3408 };
3409 
3410 unsigned int smc_net_id;
3411 
3412 static __net_init int smc_net_init(struct net *net)
3413 {
3414 	int rc;
3415 
3416 	rc = smc_sysctl_net_init(net);
3417 	if (rc)
3418 		return rc;
3419 	return smc_pnet_net_init(net);
3420 }
3421 
3422 static void __net_exit smc_net_exit(struct net *net)
3423 {
3424 	smc_sysctl_net_exit(net);
3425 	smc_pnet_net_exit(net);
3426 }
3427 
3428 static __net_init int smc_net_stat_init(struct net *net)
3429 {
3430 	return smc_stats_init(net);
3431 }
3432 
3433 static void __net_exit smc_net_stat_exit(struct net *net)
3434 {
3435 	smc_stats_exit(net);
3436 }
3437 
3438 static struct pernet_operations smc_net_ops = {
3439 	.init = smc_net_init,
3440 	.exit = smc_net_exit,
3441 	.id   = &smc_net_id,
3442 	.size = sizeof(struct smc_net),
3443 };
3444 
3445 static struct pernet_operations smc_net_stat_ops = {
3446 	.init = smc_net_stat_init,
3447 	.exit = smc_net_stat_exit,
3448 };
3449 
3450 static int __init smc_init(void)
3451 {
3452 	int rc;
3453 
3454 	rc = register_pernet_subsys(&smc_net_ops);
3455 	if (rc)
3456 		return rc;
3457 
3458 	rc = register_pernet_subsys(&smc_net_stat_ops);
3459 	if (rc)
3460 		goto out_pernet_subsys;
3461 
3462 	rc = smc_ism_init();
3463 	if (rc)
3464 		goto out_pernet_subsys_stat;
3465 	smc_clc_init();
3466 
3467 	rc = smc_nl_init();
3468 	if (rc)
3469 		goto out_ism;
3470 
3471 	rc = smc_pnet_init();
3472 	if (rc)
3473 		goto out_nl;
3474 
3475 	rc = -ENOMEM;
3476 
3477 	smc_tcp_ls_wq = alloc_workqueue("smc_tcp_ls_wq", 0, 0);
3478 	if (!smc_tcp_ls_wq)
3479 		goto out_pnet;
3480 
3481 	smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
3482 	if (!smc_hs_wq)
3483 		goto out_alloc_tcp_ls_wq;
3484 
3485 	smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
3486 	if (!smc_close_wq)
3487 		goto out_alloc_hs_wq;
3488 
3489 	rc = smc_core_init();
3490 	if (rc) {
3491 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
3492 		goto out_alloc_wqs;
3493 	}
3494 
3495 	rc = smc_llc_init();
3496 	if (rc) {
3497 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
3498 		goto out_core;
3499 	}
3500 
3501 	rc = smc_cdc_init();
3502 	if (rc) {
3503 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
3504 		goto out_core;
3505 	}
3506 
3507 	rc = proto_register(&smc_proto, 1);
3508 	if (rc) {
3509 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
3510 		goto out_core;
3511 	}
3512 
3513 	rc = proto_register(&smc_proto6, 1);
3514 	if (rc) {
3515 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
3516 		goto out_proto;
3517 	}
3518 
3519 	rc = sock_register(&smc_sock_family_ops);
3520 	if (rc) {
3521 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
3522 		goto out_proto6;
3523 	}
3524 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
3525 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
3526 
3527 	rc = smc_ib_register_client();
3528 	if (rc) {
3529 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
3530 		goto out_sock;
3531 	}
3532 
3533 	rc = tcp_register_ulp(&smc_ulp_ops);
3534 	if (rc) {
3535 		pr_err("%s: tcp_ulp_register fails with %d\n", __func__, rc);
3536 		goto out_ib;
3537 	}
3538 
3539 	static_branch_enable(&tcp_have_smc);
3540 	return 0;
3541 
3542 out_ib:
3543 	smc_ib_unregister_client();
3544 out_sock:
3545 	sock_unregister(PF_SMC);
3546 out_proto6:
3547 	proto_unregister(&smc_proto6);
3548 out_proto:
3549 	proto_unregister(&smc_proto);
3550 out_core:
3551 	smc_core_exit();
3552 out_alloc_wqs:
3553 	destroy_workqueue(smc_close_wq);
3554 out_alloc_hs_wq:
3555 	destroy_workqueue(smc_hs_wq);
3556 out_alloc_tcp_ls_wq:
3557 	destroy_workqueue(smc_tcp_ls_wq);
3558 out_pnet:
3559 	smc_pnet_exit();
3560 out_nl:
3561 	smc_nl_exit();
3562 out_ism:
3563 	smc_clc_exit();
3564 	smc_ism_exit();
3565 out_pernet_subsys_stat:
3566 	unregister_pernet_subsys(&smc_net_stat_ops);
3567 out_pernet_subsys:
3568 	unregister_pernet_subsys(&smc_net_ops);
3569 
3570 	return rc;
3571 }
3572 
3573 static void __exit smc_exit(void)
3574 {
3575 	static_branch_disable(&tcp_have_smc);
3576 	tcp_unregister_ulp(&smc_ulp_ops);
3577 	sock_unregister(PF_SMC);
3578 	smc_core_exit();
3579 	smc_ib_unregister_client();
3580 	smc_ism_exit();
3581 	destroy_workqueue(smc_close_wq);
3582 	destroy_workqueue(smc_tcp_ls_wq);
3583 	destroy_workqueue(smc_hs_wq);
3584 	proto_unregister(&smc_proto6);
3585 	proto_unregister(&smc_proto);
3586 	smc_pnet_exit();
3587 	smc_nl_exit();
3588 	smc_clc_exit();
3589 	unregister_pernet_subsys(&smc_net_stat_ops);
3590 	unregister_pernet_subsys(&smc_net_ops);
3591 	rcu_barrier();
3592 }
3593 
3594 module_init(smc_init);
3595 module_exit(smc_exit);
3596 
3597 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
3598 MODULE_DESCRIPTION("smc socket address family");
3599 MODULE_LICENSE("GPL");
3600 MODULE_ALIAS_NETPROTO(PF_SMC);
3601 MODULE_ALIAS_TCP_ULP("smc");
3602 MODULE_ALIAS_GENL_FAMILY(SMC_GENL_FAMILY_NAME);
3603