xref: /linux/net/smc/af_smc.c (revision a4989fa91110508b64eea7ccde63d062113988ff)
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 
31 #include <net/sock.h>
32 #include <net/tcp.h>
33 #include <net/smc.h>
34 #include <asm/ioctls.h>
35 
36 #include <net/net_namespace.h>
37 #include <net/netns/generic.h>
38 #include "smc_netns.h"
39 
40 #include "smc.h"
41 #include "smc_clc.h"
42 #include "smc_llc.h"
43 #include "smc_cdc.h"
44 #include "smc_core.h"
45 #include "smc_ib.h"
46 #include "smc_ism.h"
47 #include "smc_pnet.h"
48 #include "smc_tx.h"
49 #include "smc_rx.h"
50 #include "smc_close.h"
51 
52 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
53 						 * creation on server
54 						 */
55 static DEFINE_MUTEX(smc_client_lgr_pending);	/* serialize link group
56 						 * creation on client
57 						 */
58 
59 struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
60 struct workqueue_struct	*smc_close_wq;	/* wq for close work */
61 
62 static void smc_tcp_listen_work(struct work_struct *);
63 static void smc_connect_work(struct work_struct *);
64 
65 static void smc_set_keepalive(struct sock *sk, int val)
66 {
67 	struct smc_sock *smc = smc_sk(sk);
68 
69 	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
70 }
71 
72 static struct smc_hashinfo smc_v4_hashinfo = {
73 	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
74 };
75 
76 static struct smc_hashinfo smc_v6_hashinfo = {
77 	.lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
78 };
79 
80 int smc_hash_sk(struct sock *sk)
81 {
82 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
83 	struct hlist_head *head;
84 
85 	head = &h->ht;
86 
87 	write_lock_bh(&h->lock);
88 	sk_add_node(sk, head);
89 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
90 	write_unlock_bh(&h->lock);
91 
92 	return 0;
93 }
94 EXPORT_SYMBOL_GPL(smc_hash_sk);
95 
96 void smc_unhash_sk(struct sock *sk)
97 {
98 	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
99 
100 	write_lock_bh(&h->lock);
101 	if (sk_del_node_init(sk))
102 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
103 	write_unlock_bh(&h->lock);
104 }
105 EXPORT_SYMBOL_GPL(smc_unhash_sk);
106 
107 struct proto smc_proto = {
108 	.name		= "SMC",
109 	.owner		= THIS_MODULE,
110 	.keepalive	= smc_set_keepalive,
111 	.hash		= smc_hash_sk,
112 	.unhash		= smc_unhash_sk,
113 	.obj_size	= sizeof(struct smc_sock),
114 	.h.smc_hash	= &smc_v4_hashinfo,
115 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
116 };
117 EXPORT_SYMBOL_GPL(smc_proto);
118 
119 struct proto smc_proto6 = {
120 	.name		= "SMC6",
121 	.owner		= THIS_MODULE,
122 	.keepalive	= smc_set_keepalive,
123 	.hash		= smc_hash_sk,
124 	.unhash		= smc_unhash_sk,
125 	.obj_size	= sizeof(struct smc_sock),
126 	.h.smc_hash	= &smc_v6_hashinfo,
127 	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
128 };
129 EXPORT_SYMBOL_GPL(smc_proto6);
130 
131 static void smc_restore_fallback_changes(struct smc_sock *smc)
132 {
133 	if (smc->clcsock->file) { /* non-accepted sockets have no file yet */
134 		smc->clcsock->file->private_data = smc->sk.sk_socket;
135 		smc->clcsock->file = NULL;
136 	}
137 }
138 
139 static int __smc_release(struct smc_sock *smc)
140 {
141 	struct sock *sk = &smc->sk;
142 	int rc = 0;
143 
144 	if (!smc->use_fallback) {
145 		rc = smc_close_active(smc);
146 		sock_set_flag(sk, SOCK_DEAD);
147 		sk->sk_shutdown |= SHUTDOWN_MASK;
148 	} else {
149 		if (sk->sk_state != SMC_LISTEN && sk->sk_state != SMC_INIT)
150 			sock_put(sk); /* passive closing */
151 		if (sk->sk_state == SMC_LISTEN) {
152 			/* wake up clcsock accept */
153 			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
154 		}
155 		sk->sk_state = SMC_CLOSED;
156 		sk->sk_state_change(sk);
157 		smc_restore_fallback_changes(smc);
158 	}
159 
160 	sk->sk_prot->unhash(sk);
161 
162 	if (sk->sk_state == SMC_CLOSED) {
163 		if (smc->clcsock) {
164 			release_sock(sk);
165 			smc_clcsock_release(smc);
166 			lock_sock(sk);
167 		}
168 		if (!smc->use_fallback)
169 			smc_conn_free(&smc->conn);
170 	}
171 
172 	return rc;
173 }
174 
175 static int smc_release(struct socket *sock)
176 {
177 	struct sock *sk = sock->sk;
178 	struct smc_sock *smc;
179 	int rc = 0;
180 
181 	if (!sk)
182 		goto out;
183 
184 	sock_hold(sk); /* sock_put below */
185 	smc = smc_sk(sk);
186 
187 	/* cleanup for a dangling non-blocking connect */
188 	if (smc->connect_nonblock && sk->sk_state == SMC_INIT)
189 		tcp_abort(smc->clcsock->sk, ECONNABORTED);
190 	flush_work(&smc->connect_work);
191 
192 	if (sk->sk_state == SMC_LISTEN)
193 		/* smc_close_non_accepted() is called and acquires
194 		 * sock lock for child sockets again
195 		 */
196 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
197 	else
198 		lock_sock(sk);
199 
200 	rc = __smc_release(smc);
201 
202 	/* detach socket */
203 	sock_orphan(sk);
204 	sock->sk = NULL;
205 	release_sock(sk);
206 
207 	sock_put(sk); /* sock_hold above */
208 	sock_put(sk); /* final sock_put */
209 out:
210 	return rc;
211 }
212 
213 static void smc_destruct(struct sock *sk)
214 {
215 	if (sk->sk_state != SMC_CLOSED)
216 		return;
217 	if (!sock_flag(sk, SOCK_DEAD))
218 		return;
219 
220 	sk_refcnt_debug_dec(sk);
221 }
222 
223 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
224 				   int protocol)
225 {
226 	struct smc_sock *smc;
227 	struct proto *prot;
228 	struct sock *sk;
229 
230 	prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
231 	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
232 	if (!sk)
233 		return NULL;
234 
235 	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
236 	sk->sk_state = SMC_INIT;
237 	sk->sk_destruct = smc_destruct;
238 	sk->sk_protocol = protocol;
239 	smc = smc_sk(sk);
240 	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
241 	INIT_WORK(&smc->connect_work, smc_connect_work);
242 	INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
243 	INIT_LIST_HEAD(&smc->accept_q);
244 	spin_lock_init(&smc->accept_q_lock);
245 	spin_lock_init(&smc->conn.send_lock);
246 	sk->sk_prot->hash(sk);
247 	sk_refcnt_debug_inc(sk);
248 	mutex_init(&smc->clcsock_release_lock);
249 
250 	return sk;
251 }
252 
253 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
254 		    int addr_len)
255 {
256 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
257 	struct sock *sk = sock->sk;
258 	struct smc_sock *smc;
259 	int rc;
260 
261 	smc = smc_sk(sk);
262 
263 	/* replicate tests from inet_bind(), to be safe wrt. future changes */
264 	rc = -EINVAL;
265 	if (addr_len < sizeof(struct sockaddr_in))
266 		goto out;
267 
268 	rc = -EAFNOSUPPORT;
269 	if (addr->sin_family != AF_INET &&
270 	    addr->sin_family != AF_INET6 &&
271 	    addr->sin_family != AF_UNSPEC)
272 		goto out;
273 	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
274 	if (addr->sin_family == AF_UNSPEC &&
275 	    addr->sin_addr.s_addr != htonl(INADDR_ANY))
276 		goto out;
277 
278 	lock_sock(sk);
279 
280 	/* Check if socket is already active */
281 	rc = -EINVAL;
282 	if (sk->sk_state != SMC_INIT || smc->connect_nonblock)
283 		goto out_rel;
284 
285 	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
286 	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
287 
288 out_rel:
289 	release_sock(sk);
290 out:
291 	return rc;
292 }
293 
294 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
295 				   unsigned long mask)
296 {
297 	/* options we don't get control via setsockopt for */
298 	nsk->sk_type = osk->sk_type;
299 	nsk->sk_sndbuf = osk->sk_sndbuf;
300 	nsk->sk_rcvbuf = osk->sk_rcvbuf;
301 	nsk->sk_sndtimeo = osk->sk_sndtimeo;
302 	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
303 	nsk->sk_mark = osk->sk_mark;
304 	nsk->sk_priority = osk->sk_priority;
305 	nsk->sk_rcvlowat = osk->sk_rcvlowat;
306 	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
307 	nsk->sk_err = osk->sk_err;
308 
309 	nsk->sk_flags &= ~mask;
310 	nsk->sk_flags |= osk->sk_flags & mask;
311 }
312 
313 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
314 			     (1UL << SOCK_KEEPOPEN) | \
315 			     (1UL << SOCK_LINGER) | \
316 			     (1UL << SOCK_BROADCAST) | \
317 			     (1UL << SOCK_TIMESTAMP) | \
318 			     (1UL << SOCK_DBG) | \
319 			     (1UL << SOCK_RCVTSTAMP) | \
320 			     (1UL << SOCK_RCVTSTAMPNS) | \
321 			     (1UL << SOCK_LOCALROUTE) | \
322 			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
323 			     (1UL << SOCK_RXQ_OVFL) | \
324 			     (1UL << SOCK_WIFI_STATUS) | \
325 			     (1UL << SOCK_NOFCS) | \
326 			     (1UL << SOCK_FILTER_LOCKED) | \
327 			     (1UL << SOCK_TSTAMP_NEW))
328 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
329  * clc socket (since smc is not called for these options from net/core)
330  */
331 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
332 {
333 	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
334 }
335 
336 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
337 			     (1UL << SOCK_KEEPOPEN) | \
338 			     (1UL << SOCK_LINGER) | \
339 			     (1UL << SOCK_DBG))
340 /* copy only settings and flags relevant for smc from clc to smc socket */
341 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
342 {
343 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
344 }
345 
346 /* register the new rmb on all links */
347 static int smcr_lgr_reg_rmbs(struct smc_link *link,
348 			     struct smc_buf_desc *rmb_desc)
349 {
350 	struct smc_link_group *lgr = link->lgr;
351 	int i, rc = 0;
352 
353 	rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
354 	if (rc)
355 		return rc;
356 	/* protect against parallel smc_llc_cli_rkey_exchange() and
357 	 * parallel smcr_link_reg_rmb()
358 	 */
359 	mutex_lock(&lgr->llc_conf_mutex);
360 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
361 		if (!smc_link_active(&lgr->lnk[i]))
362 			continue;
363 		rc = smcr_link_reg_rmb(&lgr->lnk[i], rmb_desc);
364 		if (rc)
365 			goto out;
366 	}
367 
368 	/* exchange confirm_rkey msg with peer */
369 	rc = smc_llc_do_confirm_rkey(link, rmb_desc);
370 	if (rc) {
371 		rc = -EFAULT;
372 		goto out;
373 	}
374 	rmb_desc->is_conf_rkey = true;
375 out:
376 	mutex_unlock(&lgr->llc_conf_mutex);
377 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
378 	return rc;
379 }
380 
381 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
382 {
383 	struct smc_link *link = smc->conn.lnk;
384 	struct smc_llc_qentry *qentry;
385 	int rc;
386 
387 	/* receive CONFIRM LINK request from server over RoCE fabric */
388 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
389 			      SMC_LLC_CONFIRM_LINK);
390 	if (!qentry) {
391 		struct smc_clc_msg_decline dclc;
392 
393 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
394 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
395 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
396 	}
397 	smc_llc_save_peer_uid(qentry);
398 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
399 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
400 	if (rc)
401 		return SMC_CLC_DECL_RMBE_EC;
402 
403 	rc = smc_ib_modify_qp_rts(link);
404 	if (rc)
405 		return SMC_CLC_DECL_ERR_RDYLNK;
406 
407 	smc_wr_remember_qp_attr(link);
408 
409 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
410 		return SMC_CLC_DECL_ERR_REGRMB;
411 
412 	/* confirm_rkey is implicit on 1st contact */
413 	smc->conn.rmb_desc->is_conf_rkey = true;
414 
415 	/* send CONFIRM LINK response over RoCE fabric */
416 	rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
417 	if (rc < 0)
418 		return SMC_CLC_DECL_TIMEOUT_CL;
419 
420 	smc_llc_link_active(link);
421 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
422 
423 	/* optional 2nd link, receive ADD LINK request from server */
424 	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
425 			      SMC_LLC_ADD_LINK);
426 	if (!qentry) {
427 		struct smc_clc_msg_decline dclc;
428 
429 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
430 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
431 		if (rc == -EAGAIN)
432 			rc = 0; /* no DECLINE received, go with one link */
433 		return rc;
434 	}
435 	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
436 	smc_llc_cli_add_link(link, qentry);
437 	return 0;
438 }
439 
440 static void smcr_conn_save_peer_info(struct smc_sock *smc,
441 				     struct smc_clc_msg_accept_confirm *clc)
442 {
443 	int bufsize = smc_uncompress_bufsize(clc->r0.rmbe_size);
444 
445 	smc->conn.peer_rmbe_idx = clc->r0.rmbe_idx;
446 	smc->conn.local_tx_ctrl.token = ntohl(clc->r0.rmbe_alert_token);
447 	smc->conn.peer_rmbe_size = bufsize;
448 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
449 	smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
450 }
451 
452 static bool smc_isascii(char *hostname)
453 {
454 	int i;
455 
456 	for (i = 0; i < SMC_MAX_HOSTNAME_LEN; i++)
457 		if (!isascii(hostname[i]))
458 			return false;
459 	return true;
460 }
461 
462 static void smcd_conn_save_peer_info(struct smc_sock *smc,
463 				     struct smc_clc_msg_accept_confirm *clc)
464 {
465 	int bufsize = smc_uncompress_bufsize(clc->d0.dmbe_size);
466 
467 	smc->conn.peer_rmbe_idx = clc->d0.dmbe_idx;
468 	smc->conn.peer_token = clc->d0.token;
469 	/* msg header takes up space in the buffer */
470 	smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
471 	atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
472 	smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
473 	if (clc->hdr.version > SMC_V1 &&
474 	    (clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK)) {
475 		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
476 			(struct smc_clc_msg_accept_confirm_v2 *)clc;
477 		struct smc_clc_first_contact_ext *fce =
478 			(struct smc_clc_first_contact_ext *)
479 				(((u8 *)clc_v2) + sizeof(*clc_v2));
480 
481 		memcpy(smc->conn.lgr->negotiated_eid, clc_v2->eid,
482 		       SMC_MAX_EID_LEN);
483 		smc->conn.lgr->peer_os = fce->os_type;
484 		smc->conn.lgr->peer_smc_release = fce->release;
485 		if (smc_isascii(fce->hostname))
486 			memcpy(smc->conn.lgr->peer_hostname, fce->hostname,
487 			       SMC_MAX_HOSTNAME_LEN);
488 	}
489 }
490 
491 static void smc_conn_save_peer_info(struct smc_sock *smc,
492 				    struct smc_clc_msg_accept_confirm *clc)
493 {
494 	if (smc->conn.lgr->is_smcd)
495 		smcd_conn_save_peer_info(smc, clc);
496 	else
497 		smcr_conn_save_peer_info(smc, clc);
498 }
499 
500 static void smc_link_save_peer_info(struct smc_link *link,
501 				    struct smc_clc_msg_accept_confirm *clc)
502 {
503 	link->peer_qpn = ntoh24(clc->r0.qpn);
504 	memcpy(link->peer_gid, clc->r0.lcl.gid, SMC_GID_SIZE);
505 	memcpy(link->peer_mac, clc->r0.lcl.mac, sizeof(link->peer_mac));
506 	link->peer_psn = ntoh24(clc->r0.psn);
507 	link->peer_mtu = clc->r0.qp_mtu;
508 }
509 
510 static void smc_switch_to_fallback(struct smc_sock *smc)
511 {
512 	smc->use_fallback = true;
513 	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
514 		smc->clcsock->file = smc->sk.sk_socket->file;
515 		smc->clcsock->file->private_data = smc->clcsock;
516 		smc->clcsock->wq.fasync_list =
517 			smc->sk.sk_socket->wq.fasync_list;
518 	}
519 }
520 
521 /* fall back during connect */
522 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
523 {
524 	smc_switch_to_fallback(smc);
525 	smc->fallback_rsn = reason_code;
526 	smc_copy_sock_settings_to_clc(smc);
527 	smc->connect_nonblock = 0;
528 	if (smc->sk.sk_state == SMC_INIT)
529 		smc->sk.sk_state = SMC_ACTIVE;
530 	return 0;
531 }
532 
533 /* decline and fall back during connect */
534 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
535 					u8 version)
536 {
537 	int rc;
538 
539 	if (reason_code < 0) { /* error, fallback is not possible */
540 		if (smc->sk.sk_state == SMC_INIT)
541 			sock_put(&smc->sk); /* passive closing */
542 		return reason_code;
543 	}
544 	if (reason_code != SMC_CLC_DECL_PEERDECL) {
545 		rc = smc_clc_send_decline(smc, reason_code, version);
546 		if (rc < 0) {
547 			if (smc->sk.sk_state == SMC_INIT)
548 				sock_put(&smc->sk); /* passive closing */
549 			return rc;
550 		}
551 	}
552 	return smc_connect_fallback(smc, reason_code);
553 }
554 
555 /* abort connecting */
556 static void smc_connect_abort(struct smc_sock *smc, int local_first)
557 {
558 	if (local_first)
559 		smc_lgr_cleanup_early(&smc->conn);
560 	else
561 		smc_conn_free(&smc->conn);
562 }
563 
564 /* check if there is a rdma device available for this connection. */
565 /* called for connect and listen */
566 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
567 {
568 	/* PNET table look up: search active ib_device and port
569 	 * within same PNETID that also contains the ethernet device
570 	 * used for the internal TCP socket
571 	 */
572 	smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
573 	if (!ini->ib_dev)
574 		return SMC_CLC_DECL_NOSMCRDEV;
575 	return 0;
576 }
577 
578 /* check if there is an ISM device available for this connection. */
579 /* called for connect and listen */
580 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
581 {
582 	/* Find ISM device with same PNETID as connecting interface  */
583 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
584 	if (!ini->ism_dev[0])
585 		return SMC_CLC_DECL_NOSMCDDEV;
586 	else
587 		ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
588 	return 0;
589 }
590 
591 /* is chid unique for the ism devices that are already determined? */
592 static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
593 					   int cnt)
594 {
595 	int i = (!ini->ism_dev[0]) ? 1 : 0;
596 
597 	for (; i < cnt; i++)
598 		if (ini->ism_chid[i] == chid)
599 			return false;
600 	return true;
601 }
602 
603 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
604  * PNETID matching net_device)
605  */
606 static int smc_find_ism_v2_device_clnt(struct smc_sock *smc,
607 				       struct smc_init_info *ini)
608 {
609 	int rc = SMC_CLC_DECL_NOSMCDDEV;
610 	struct smcd_dev *smcd;
611 	int i = 1;
612 	u16 chid;
613 
614 	if (smcd_indicated(ini->smc_type_v1))
615 		rc = 0;		/* already initialized for V1 */
616 	mutex_lock(&smcd_dev_list.mutex);
617 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
618 		if (smcd->going_away || smcd == ini->ism_dev[0])
619 			continue;
620 		chid = smc_ism_get_chid(smcd);
621 		if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
622 			continue;
623 		if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
624 		    smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
625 			ini->ism_dev[i] = smcd;
626 			ini->ism_chid[i] = chid;
627 			ini->is_smcd = true;
628 			rc = 0;
629 			i++;
630 			if (i > SMC_MAX_ISM_DEVS)
631 				break;
632 		}
633 	}
634 	mutex_unlock(&smcd_dev_list.mutex);
635 	ini->ism_offered_cnt = i - 1;
636 	if (!ini->ism_dev[0] && !ini->ism_dev[1])
637 		ini->smcd_version = 0;
638 
639 	return rc;
640 }
641 
642 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
643 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
644 				      struct smc_init_info *ini)
645 {
646 	if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev[0], ini->vlan_id))
647 		return SMC_CLC_DECL_ISMVLANERR;
648 	return 0;
649 }
650 
651 static int smc_find_proposal_devices(struct smc_sock *smc,
652 				     struct smc_init_info *ini)
653 {
654 	int rc = 0;
655 
656 	/* check if there is an ism device available */
657 	if (ini->smcd_version & SMC_V1) {
658 		if (smc_find_ism_device(smc, ini) ||
659 		    smc_connect_ism_vlan_setup(smc, ini)) {
660 			if (ini->smc_type_v1 == SMC_TYPE_B)
661 				ini->smc_type_v1 = SMC_TYPE_R;
662 			else
663 				ini->smc_type_v1 = SMC_TYPE_N;
664 		} /* else ISM V1 is supported for this connection */
665 		if (smc_find_rdma_device(smc, ini)) {
666 			if (ini->smc_type_v1 == SMC_TYPE_B)
667 				ini->smc_type_v1 = SMC_TYPE_D;
668 			else
669 				ini->smc_type_v1 = SMC_TYPE_N;
670 		} /* else RDMA is supported for this connection */
671 	}
672 	if (smc_ism_v2_capable && smc_find_ism_v2_device_clnt(smc, ini))
673 		ini->smc_type_v2 = SMC_TYPE_N;
674 
675 	/* if neither ISM nor RDMA are supported, fallback */
676 	if (!smcr_indicated(ini->smc_type_v1) &&
677 	    ini->smc_type_v1 == SMC_TYPE_N && ini->smc_type_v2 == SMC_TYPE_N)
678 		rc = SMC_CLC_DECL_NOSMCDEV;
679 
680 	return rc;
681 }
682 
683 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
684  * used, the VLAN ID will be registered again during the connection setup.
685  */
686 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
687 					struct smc_init_info *ini)
688 {
689 	if (!smcd_indicated(ini->smc_type_v1))
690 		return 0;
691 	if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev[0], ini->vlan_id))
692 		return SMC_CLC_DECL_CNFERR;
693 	return 0;
694 }
695 
696 #define SMC_CLC_MAX_ACCEPT_LEN \
697 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
698 	 sizeof(struct smc_clc_first_contact_ext) + \
699 	 sizeof(struct smc_clc_msg_trail))
700 
701 /* CLC handshake during connect */
702 static int smc_connect_clc(struct smc_sock *smc,
703 			   struct smc_clc_msg_accept_confirm_v2 *aclc2,
704 			   struct smc_init_info *ini)
705 {
706 	int rc = 0;
707 
708 	/* do inband token exchange */
709 	rc = smc_clc_send_proposal(smc, ini);
710 	if (rc)
711 		return rc;
712 	/* receive SMC Accept CLC message */
713 	return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
714 				SMC_CLC_ACCEPT, CLC_WAIT_TIME);
715 }
716 
717 /* setup for RDMA connection of client */
718 static int smc_connect_rdma(struct smc_sock *smc,
719 			    struct smc_clc_msg_accept_confirm *aclc,
720 			    struct smc_init_info *ini)
721 {
722 	int i, reason_code = 0;
723 	struct smc_link *link;
724 
725 	ini->is_smcd = false;
726 	ini->ib_lcl = &aclc->r0.lcl;
727 	ini->ib_clcqpn = ntoh24(aclc->r0.qpn);
728 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
729 
730 	mutex_lock(&smc_client_lgr_pending);
731 	reason_code = smc_conn_create(smc, ini);
732 	if (reason_code) {
733 		mutex_unlock(&smc_client_lgr_pending);
734 		return reason_code;
735 	}
736 
737 	smc_conn_save_peer_info(smc, aclc);
738 
739 	if (ini->first_contact_local) {
740 		link = smc->conn.lnk;
741 	} else {
742 		/* set link that was assigned by server */
743 		link = NULL;
744 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
745 			struct smc_link *l = &smc->conn.lgr->lnk[i];
746 
747 			if (l->peer_qpn == ntoh24(aclc->r0.qpn) &&
748 			    !memcmp(l->peer_gid, &aclc->r0.lcl.gid,
749 				    SMC_GID_SIZE) &&
750 			    !memcmp(l->peer_mac, &aclc->r0.lcl.mac,
751 				    sizeof(l->peer_mac))) {
752 				link = l;
753 				break;
754 			}
755 		}
756 		if (!link) {
757 			reason_code = SMC_CLC_DECL_NOSRVLINK;
758 			goto connect_abort;
759 		}
760 		smc->conn.lnk = link;
761 	}
762 
763 	/* create send buffer and rmb */
764 	if (smc_buf_create(smc, false)) {
765 		reason_code = SMC_CLC_DECL_MEM;
766 		goto connect_abort;
767 	}
768 
769 	if (ini->first_contact_local)
770 		smc_link_save_peer_info(link, aclc);
771 
772 	if (smc_rmb_rtoken_handling(&smc->conn, link, aclc)) {
773 		reason_code = SMC_CLC_DECL_ERR_RTOK;
774 		goto connect_abort;
775 	}
776 
777 	smc_close_init(smc);
778 	smc_rx_init(smc);
779 
780 	if (ini->first_contact_local) {
781 		if (smc_ib_ready_link(link)) {
782 			reason_code = SMC_CLC_DECL_ERR_RDYLNK;
783 			goto connect_abort;
784 		}
785 	} else {
786 		if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc)) {
787 			reason_code = SMC_CLC_DECL_ERR_REGRMB;
788 			goto connect_abort;
789 		}
790 	}
791 	smc_rmb_sync_sg_for_device(&smc->conn);
792 
793 	reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
794 					   SMC_V1);
795 	if (reason_code)
796 		goto connect_abort;
797 
798 	smc_tx_init(smc);
799 
800 	if (ini->first_contact_local) {
801 		/* QP confirmation over RoCE fabric */
802 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
803 		reason_code = smcr_clnt_conf_first_link(smc);
804 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
805 		if (reason_code)
806 			goto connect_abort;
807 	}
808 	mutex_unlock(&smc_client_lgr_pending);
809 
810 	smc_copy_sock_settings_to_clc(smc);
811 	smc->connect_nonblock = 0;
812 	if (smc->sk.sk_state == SMC_INIT)
813 		smc->sk.sk_state = SMC_ACTIVE;
814 
815 	return 0;
816 connect_abort:
817 	smc_connect_abort(smc, ini->first_contact_local);
818 	mutex_unlock(&smc_client_lgr_pending);
819 	smc->connect_nonblock = 0;
820 
821 	return reason_code;
822 }
823 
824 /* The server has chosen one of the proposed ISM devices for the communication.
825  * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
826  */
827 static int
828 smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
829 			       struct smc_init_info *ini)
830 {
831 	int i;
832 
833 	for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
834 		if (ini->ism_chid[i] == ntohs(aclc->chid)) {
835 			ini->ism_selected = i;
836 			return 0;
837 		}
838 	}
839 
840 	return -EPROTO;
841 }
842 
843 /* setup for ISM connection of client */
844 static int smc_connect_ism(struct smc_sock *smc,
845 			   struct smc_clc_msg_accept_confirm *aclc,
846 			   struct smc_init_info *ini)
847 {
848 	int rc = 0;
849 
850 	ini->is_smcd = true;
851 	ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
852 
853 	if (aclc->hdr.version == SMC_V2) {
854 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
855 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
856 
857 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
858 		if (rc)
859 			return rc;
860 	}
861 	ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
862 
863 	/* there is only one lgr role for SMC-D; use server lock */
864 	mutex_lock(&smc_server_lgr_pending);
865 	rc = smc_conn_create(smc, ini);
866 	if (rc) {
867 		mutex_unlock(&smc_server_lgr_pending);
868 		return rc;
869 	}
870 
871 	/* Create send and receive buffers */
872 	rc = smc_buf_create(smc, true);
873 	if (rc) {
874 		rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
875 		goto connect_abort;
876 	}
877 
878 	smc_conn_save_peer_info(smc, aclc);
879 	smc_close_init(smc);
880 	smc_rx_init(smc);
881 	smc_tx_init(smc);
882 
883 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
884 				  aclc->hdr.version);
885 	if (rc)
886 		goto connect_abort;
887 	mutex_unlock(&smc_server_lgr_pending);
888 
889 	smc_copy_sock_settings_to_clc(smc);
890 	smc->connect_nonblock = 0;
891 	if (smc->sk.sk_state == SMC_INIT)
892 		smc->sk.sk_state = SMC_ACTIVE;
893 
894 	return 0;
895 connect_abort:
896 	smc_connect_abort(smc, ini->first_contact_local);
897 	mutex_unlock(&smc_server_lgr_pending);
898 	smc->connect_nonblock = 0;
899 
900 	return rc;
901 }
902 
903 /* check if received accept type and version matches a proposed one */
904 static int smc_connect_check_aclc(struct smc_init_info *ini,
905 				  struct smc_clc_msg_accept_confirm *aclc)
906 {
907 	if ((aclc->hdr.typev1 == SMC_TYPE_R &&
908 	     !smcr_indicated(ini->smc_type_v1)) ||
909 	    (aclc->hdr.typev1 == SMC_TYPE_D &&
910 	     ((!smcd_indicated(ini->smc_type_v1) &&
911 	       !smcd_indicated(ini->smc_type_v2)) ||
912 	      (aclc->hdr.version == SMC_V1 &&
913 	       !smcd_indicated(ini->smc_type_v1)) ||
914 	      (aclc->hdr.version == SMC_V2 &&
915 	       !smcd_indicated(ini->smc_type_v2)))))
916 		return SMC_CLC_DECL_MODEUNSUPP;
917 
918 	return 0;
919 }
920 
921 /* perform steps before actually connecting */
922 static int __smc_connect(struct smc_sock *smc)
923 {
924 	u8 version = smc_ism_v2_capable ? SMC_V2 : SMC_V1;
925 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
926 	struct smc_clc_msg_accept_confirm *aclc;
927 	struct smc_init_info *ini = NULL;
928 	u8 *buf = NULL;
929 	int rc = 0;
930 
931 	if (smc->use_fallback)
932 		return smc_connect_fallback(smc, smc->fallback_rsn);
933 
934 	/* if peer has not signalled SMC-capability, fall back */
935 	if (!tcp_sk(smc->clcsock->sk)->syn_smc)
936 		return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
937 
938 	/* IPSec connections opt out of SMC optimizations */
939 	if (using_ipsec(smc))
940 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
941 						    version);
942 
943 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
944 	if (!ini)
945 		return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
946 						    version);
947 
948 	ini->smcd_version = SMC_V1;
949 	ini->smcd_version |= smc_ism_v2_capable ? SMC_V2 : 0;
950 	ini->smc_type_v1 = SMC_TYPE_B;
951 	ini->smc_type_v2 = smc_ism_v2_capable ? SMC_TYPE_D : SMC_TYPE_N;
952 
953 	/* get vlan id from IP device */
954 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
955 		ini->smcd_version &= ~SMC_V1;
956 		ini->smc_type_v1 = SMC_TYPE_N;
957 		if (!ini->smcd_version) {
958 			rc = SMC_CLC_DECL_GETVLANERR;
959 			goto fallback;
960 		}
961 	}
962 
963 	rc = smc_find_proposal_devices(smc, ini);
964 	if (rc)
965 		goto fallback;
966 
967 	buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
968 	if (!buf) {
969 		rc = SMC_CLC_DECL_MEM;
970 		goto fallback;
971 	}
972 	aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
973 	aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
974 
975 	/* perform CLC handshake */
976 	rc = smc_connect_clc(smc, aclc2, ini);
977 	if (rc)
978 		goto vlan_cleanup;
979 
980 	/* check if smc modes and versions of CLC proposal and accept match */
981 	rc = smc_connect_check_aclc(ini, aclc);
982 	version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
983 	ini->smcd_version = version;
984 	if (rc)
985 		goto vlan_cleanup;
986 
987 	/* depending on previous steps, connect using rdma or ism */
988 	if (aclc->hdr.typev1 == SMC_TYPE_R)
989 		rc = smc_connect_rdma(smc, aclc, ini);
990 	else if (aclc->hdr.typev1 == SMC_TYPE_D)
991 		rc = smc_connect_ism(smc, aclc, ini);
992 	if (rc)
993 		goto vlan_cleanup;
994 
995 	smc_connect_ism_vlan_cleanup(smc, ini);
996 	kfree(buf);
997 	kfree(ini);
998 	return 0;
999 
1000 vlan_cleanup:
1001 	smc_connect_ism_vlan_cleanup(smc, ini);
1002 	kfree(buf);
1003 fallback:
1004 	kfree(ini);
1005 	return smc_connect_decline_fallback(smc, rc, version);
1006 }
1007 
1008 static void smc_connect_work(struct work_struct *work)
1009 {
1010 	struct smc_sock *smc = container_of(work, struct smc_sock,
1011 					    connect_work);
1012 	long timeo = smc->sk.sk_sndtimeo;
1013 	int rc = 0;
1014 
1015 	if (!timeo)
1016 		timeo = MAX_SCHEDULE_TIMEOUT;
1017 	lock_sock(smc->clcsock->sk);
1018 	if (smc->clcsock->sk->sk_err) {
1019 		smc->sk.sk_err = smc->clcsock->sk->sk_err;
1020 	} else if ((1 << smc->clcsock->sk->sk_state) &
1021 					(TCPF_SYN_SENT | TCP_SYN_RECV)) {
1022 		rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
1023 		if ((rc == -EPIPE) &&
1024 		    ((1 << smc->clcsock->sk->sk_state) &
1025 					(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
1026 			rc = 0;
1027 	}
1028 	release_sock(smc->clcsock->sk);
1029 	lock_sock(&smc->sk);
1030 	if (rc != 0 || smc->sk.sk_err) {
1031 		smc->sk.sk_state = SMC_CLOSED;
1032 		if (rc == -EPIPE || rc == -EAGAIN)
1033 			smc->sk.sk_err = EPIPE;
1034 		else if (signal_pending(current))
1035 			smc->sk.sk_err = -sock_intr_errno(timeo);
1036 		sock_put(&smc->sk); /* passive closing */
1037 		goto out;
1038 	}
1039 
1040 	rc = __smc_connect(smc);
1041 	if (rc < 0)
1042 		smc->sk.sk_err = -rc;
1043 
1044 out:
1045 	if (!sock_flag(&smc->sk, SOCK_DEAD)) {
1046 		if (smc->sk.sk_err) {
1047 			smc->sk.sk_state_change(&smc->sk);
1048 		} else { /* allow polling before and after fallback decision */
1049 			smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
1050 			smc->sk.sk_write_space(&smc->sk);
1051 		}
1052 	}
1053 	release_sock(&smc->sk);
1054 }
1055 
1056 static int smc_connect(struct socket *sock, struct sockaddr *addr,
1057 		       int alen, int flags)
1058 {
1059 	struct sock *sk = sock->sk;
1060 	struct smc_sock *smc;
1061 	int rc = -EINVAL;
1062 
1063 	smc = smc_sk(sk);
1064 
1065 	/* separate smc parameter checking to be safe */
1066 	if (alen < sizeof(addr->sa_family))
1067 		goto out_err;
1068 	if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
1069 		goto out_err;
1070 
1071 	lock_sock(sk);
1072 	switch (sk->sk_state) {
1073 	default:
1074 		goto out;
1075 	case SMC_ACTIVE:
1076 		rc = -EISCONN;
1077 		goto out;
1078 	case SMC_INIT:
1079 		rc = 0;
1080 		break;
1081 	}
1082 
1083 	smc_copy_sock_settings_to_clc(smc);
1084 	tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1085 	if (smc->connect_nonblock) {
1086 		rc = -EALREADY;
1087 		goto out;
1088 	}
1089 	rc = kernel_connect(smc->clcsock, addr, alen, flags);
1090 	if (rc && rc != -EINPROGRESS)
1091 		goto out;
1092 
1093 	sock_hold(&smc->sk); /* sock put in passive closing */
1094 	if (smc->use_fallback)
1095 		goto out;
1096 	if (flags & O_NONBLOCK) {
1097 		if (queue_work(smc_hs_wq, &smc->connect_work))
1098 			smc->connect_nonblock = 1;
1099 		rc = -EINPROGRESS;
1100 	} else {
1101 		rc = __smc_connect(smc);
1102 		if (rc < 0)
1103 			goto out;
1104 		else
1105 			rc = 0; /* success cases including fallback */
1106 	}
1107 
1108 out:
1109 	release_sock(sk);
1110 out_err:
1111 	return rc;
1112 }
1113 
1114 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
1115 {
1116 	struct socket *new_clcsock = NULL;
1117 	struct sock *lsk = &lsmc->sk;
1118 	struct sock *new_sk;
1119 	int rc = -EINVAL;
1120 
1121 	release_sock(lsk);
1122 	new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
1123 	if (!new_sk) {
1124 		rc = -ENOMEM;
1125 		lsk->sk_err = ENOMEM;
1126 		*new_smc = NULL;
1127 		lock_sock(lsk);
1128 		goto out;
1129 	}
1130 	*new_smc = smc_sk(new_sk);
1131 
1132 	mutex_lock(&lsmc->clcsock_release_lock);
1133 	if (lsmc->clcsock)
1134 		rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
1135 	mutex_unlock(&lsmc->clcsock_release_lock);
1136 	lock_sock(lsk);
1137 	if  (rc < 0 && rc != -EAGAIN)
1138 		lsk->sk_err = -rc;
1139 	if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
1140 		new_sk->sk_prot->unhash(new_sk);
1141 		if (new_clcsock)
1142 			sock_release(new_clcsock);
1143 		new_sk->sk_state = SMC_CLOSED;
1144 		sock_set_flag(new_sk, SOCK_DEAD);
1145 		sock_put(new_sk); /* final */
1146 		*new_smc = NULL;
1147 		goto out;
1148 	}
1149 
1150 	/* new clcsock has inherited the smc listen-specific sk_data_ready
1151 	 * function; switch it back to the original sk_data_ready function
1152 	 */
1153 	new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
1154 	(*new_smc)->clcsock = new_clcsock;
1155 out:
1156 	return rc;
1157 }
1158 
1159 /* add a just created sock to the accept queue of the listen sock as
1160  * candidate for a following socket accept call from user space
1161  */
1162 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
1163 {
1164 	struct smc_sock *par = smc_sk(parent);
1165 
1166 	sock_hold(sk); /* sock_put in smc_accept_unlink () */
1167 	spin_lock(&par->accept_q_lock);
1168 	list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
1169 	spin_unlock(&par->accept_q_lock);
1170 	sk_acceptq_added(parent);
1171 }
1172 
1173 /* remove a socket from the accept queue of its parental listening socket */
1174 static void smc_accept_unlink(struct sock *sk)
1175 {
1176 	struct smc_sock *par = smc_sk(sk)->listen_smc;
1177 
1178 	spin_lock(&par->accept_q_lock);
1179 	list_del_init(&smc_sk(sk)->accept_q);
1180 	spin_unlock(&par->accept_q_lock);
1181 	sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
1182 	sock_put(sk); /* sock_hold in smc_accept_enqueue */
1183 }
1184 
1185 /* remove a sock from the accept queue to bind it to a new socket created
1186  * for a socket accept call from user space
1187  */
1188 struct sock *smc_accept_dequeue(struct sock *parent,
1189 				struct socket *new_sock)
1190 {
1191 	struct smc_sock *isk, *n;
1192 	struct sock *new_sk;
1193 
1194 	list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
1195 		new_sk = (struct sock *)isk;
1196 
1197 		smc_accept_unlink(new_sk);
1198 		if (new_sk->sk_state == SMC_CLOSED) {
1199 			new_sk->sk_prot->unhash(new_sk);
1200 			if (isk->clcsock) {
1201 				sock_release(isk->clcsock);
1202 				isk->clcsock = NULL;
1203 			}
1204 			sock_put(new_sk); /* final */
1205 			continue;
1206 		}
1207 		if (new_sock) {
1208 			sock_graft(new_sk, new_sock);
1209 			if (isk->use_fallback) {
1210 				smc_sk(new_sk)->clcsock->file = new_sock->file;
1211 				isk->clcsock->file->private_data = isk->clcsock;
1212 			}
1213 		}
1214 		return new_sk;
1215 	}
1216 	return NULL;
1217 }
1218 
1219 /* clean up for a created but never accepted sock */
1220 void smc_close_non_accepted(struct sock *sk)
1221 {
1222 	struct smc_sock *smc = smc_sk(sk);
1223 
1224 	sock_hold(sk); /* sock_put below */
1225 	lock_sock(sk);
1226 	if (!sk->sk_lingertime)
1227 		/* wait for peer closing */
1228 		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
1229 	__smc_release(smc);
1230 	release_sock(sk);
1231 	sock_put(sk); /* sock_hold above */
1232 	sock_put(sk); /* final sock_put */
1233 }
1234 
1235 static int smcr_serv_conf_first_link(struct smc_sock *smc)
1236 {
1237 	struct smc_link *link = smc->conn.lnk;
1238 	struct smc_llc_qentry *qentry;
1239 	int rc;
1240 
1241 	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc))
1242 		return SMC_CLC_DECL_ERR_REGRMB;
1243 
1244 	/* send CONFIRM LINK request to client over the RoCE fabric */
1245 	rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
1246 	if (rc < 0)
1247 		return SMC_CLC_DECL_TIMEOUT_CL;
1248 
1249 	/* receive CONFIRM LINK response from client over the RoCE fabric */
1250 	qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
1251 			      SMC_LLC_CONFIRM_LINK);
1252 	if (!qentry) {
1253 		struct smc_clc_msg_decline dclc;
1254 
1255 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
1256 				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
1257 		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
1258 	}
1259 	smc_llc_save_peer_uid(qentry);
1260 	rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
1261 	smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
1262 	if (rc)
1263 		return SMC_CLC_DECL_RMBE_EC;
1264 
1265 	/* confirm_rkey is implicit on 1st contact */
1266 	smc->conn.rmb_desc->is_conf_rkey = true;
1267 
1268 	smc_llc_link_active(link);
1269 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
1270 
1271 	/* initial contact - try to establish second link */
1272 	smc_llc_srv_add_link(link);
1273 	return 0;
1274 }
1275 
1276 /* listen worker: finish */
1277 static void smc_listen_out(struct smc_sock *new_smc)
1278 {
1279 	struct smc_sock *lsmc = new_smc->listen_smc;
1280 	struct sock *newsmcsk = &new_smc->sk;
1281 
1282 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1283 		lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
1284 		smc_accept_enqueue(&lsmc->sk, newsmcsk);
1285 		release_sock(&lsmc->sk);
1286 	} else { /* no longer listening */
1287 		smc_close_non_accepted(newsmcsk);
1288 	}
1289 
1290 	/* Wake up accept */
1291 	lsmc->sk.sk_data_ready(&lsmc->sk);
1292 	sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
1293 }
1294 
1295 /* listen worker: finish in state connected */
1296 static void smc_listen_out_connected(struct smc_sock *new_smc)
1297 {
1298 	struct sock *newsmcsk = &new_smc->sk;
1299 
1300 	sk_refcnt_debug_inc(newsmcsk);
1301 	if (newsmcsk->sk_state == SMC_INIT)
1302 		newsmcsk->sk_state = SMC_ACTIVE;
1303 
1304 	smc_listen_out(new_smc);
1305 }
1306 
1307 /* listen worker: finish in error state */
1308 static void smc_listen_out_err(struct smc_sock *new_smc)
1309 {
1310 	struct sock *newsmcsk = &new_smc->sk;
1311 
1312 	if (newsmcsk->sk_state == SMC_INIT)
1313 		sock_put(&new_smc->sk); /* passive closing */
1314 	newsmcsk->sk_state = SMC_CLOSED;
1315 
1316 	smc_listen_out(new_smc);
1317 }
1318 
1319 /* listen worker: decline and fall back if possible */
1320 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
1321 			       int local_first, u8 version)
1322 {
1323 	/* RDMA setup failed, switch back to TCP */
1324 	if (local_first)
1325 		smc_lgr_cleanup_early(&new_smc->conn);
1326 	else
1327 		smc_conn_free(&new_smc->conn);
1328 	if (reason_code < 0) { /* error, no fallback possible */
1329 		smc_listen_out_err(new_smc);
1330 		return;
1331 	}
1332 	smc_switch_to_fallback(new_smc);
1333 	new_smc->fallback_rsn = reason_code;
1334 	if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
1335 		if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
1336 			smc_listen_out_err(new_smc);
1337 			return;
1338 		}
1339 	}
1340 	smc_listen_out_connected(new_smc);
1341 }
1342 
1343 /* listen worker: version checking */
1344 static int smc_listen_v2_check(struct smc_sock *new_smc,
1345 			       struct smc_clc_msg_proposal *pclc,
1346 			       struct smc_init_info *ini)
1347 {
1348 	struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
1349 	struct smc_clc_v2_extension *pclc_v2_ext;
1350 	int rc = SMC_CLC_DECL_PEERNOSMC;
1351 
1352 	ini->smc_type_v1 = pclc->hdr.typev1;
1353 	ini->smc_type_v2 = pclc->hdr.typev2;
1354 	ini->smcd_version = ini->smc_type_v1 != SMC_TYPE_N ? SMC_V1 : 0;
1355 	if (pclc->hdr.version > SMC_V1)
1356 		ini->smcd_version |=
1357 				ini->smc_type_v2 != SMC_TYPE_N ? SMC_V2 : 0;
1358 	if (!(ini->smcd_version & SMC_V2)) {
1359 		rc = SMC_CLC_DECL_PEERNOSMC;
1360 		goto out;
1361 	}
1362 	if (!smc_ism_v2_capable) {
1363 		ini->smcd_version &= ~SMC_V2;
1364 		rc = SMC_CLC_DECL_NOISM2SUPP;
1365 		goto out;
1366 	}
1367 	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
1368 	if (!pclc_v2_ext) {
1369 		ini->smcd_version &= ~SMC_V2;
1370 		rc = SMC_CLC_DECL_NOV2EXT;
1371 		goto out;
1372 	}
1373 	pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
1374 	if (!pclc_smcd_v2_ext) {
1375 		ini->smcd_version &= ~SMC_V2;
1376 		rc = SMC_CLC_DECL_NOV2DEXT;
1377 	}
1378 
1379 out:
1380 	if (!ini->smcd_version)
1381 		return rc;
1382 
1383 	return 0;
1384 }
1385 
1386 /* listen worker: check prefixes */
1387 static int smc_listen_prfx_check(struct smc_sock *new_smc,
1388 				 struct smc_clc_msg_proposal *pclc)
1389 {
1390 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
1391 	struct socket *newclcsock = new_smc->clcsock;
1392 
1393 	if (pclc->hdr.typev1 == SMC_TYPE_N)
1394 		return 0;
1395 	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
1396 	if (smc_clc_prfx_match(newclcsock, pclc_prfx))
1397 		return SMC_CLC_DECL_DIFFPREFIX;
1398 
1399 	return 0;
1400 }
1401 
1402 /* listen worker: initialize connection and buffers */
1403 static int smc_listen_rdma_init(struct smc_sock *new_smc,
1404 				struct smc_init_info *ini)
1405 {
1406 	int rc;
1407 
1408 	/* allocate connection / link group */
1409 	rc = smc_conn_create(new_smc, ini);
1410 	if (rc)
1411 		return rc;
1412 
1413 	/* create send buffer and rmb */
1414 	if (smc_buf_create(new_smc, false))
1415 		return SMC_CLC_DECL_MEM;
1416 
1417 	return 0;
1418 }
1419 
1420 /* listen worker: initialize connection and buffers for SMC-D */
1421 static int smc_listen_ism_init(struct smc_sock *new_smc,
1422 			       struct smc_init_info *ini)
1423 {
1424 	int rc;
1425 
1426 	rc = smc_conn_create(new_smc, ini);
1427 	if (rc)
1428 		return rc;
1429 
1430 	/* Create send and receive buffers */
1431 	rc = smc_buf_create(new_smc, true);
1432 	if (rc) {
1433 		if (ini->first_contact_local)
1434 			smc_lgr_cleanup_early(&new_smc->conn);
1435 		else
1436 			smc_conn_free(&new_smc->conn);
1437 		return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
1438 					 SMC_CLC_DECL_MEM;
1439 	}
1440 
1441 	return 0;
1442 }
1443 
1444 static bool smc_is_already_selected(struct smcd_dev *smcd,
1445 				    struct smc_init_info *ini,
1446 				    int matches)
1447 {
1448 	int i;
1449 
1450 	for (i = 0; i < matches; i++)
1451 		if (smcd == ini->ism_dev[i])
1452 			return true;
1453 
1454 	return false;
1455 }
1456 
1457 /* check for ISM devices matching proposed ISM devices */
1458 static void smc_check_ism_v2_match(struct smc_init_info *ini,
1459 				   u16 proposed_chid, u64 proposed_gid,
1460 				   unsigned int *matches)
1461 {
1462 	struct smcd_dev *smcd;
1463 
1464 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1465 		if (smcd->going_away)
1466 			continue;
1467 		if (smc_is_already_selected(smcd, ini, *matches))
1468 			continue;
1469 		if (smc_ism_get_chid(smcd) == proposed_chid &&
1470 		    !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
1471 			ini->ism_peer_gid[*matches] = proposed_gid;
1472 			ini->ism_dev[*matches] = smcd;
1473 			(*matches)++;
1474 			break;
1475 		}
1476 	}
1477 }
1478 
1479 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
1480 {
1481 	if (!ini->rc)
1482 		ini->rc = rc;
1483 }
1484 
1485 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
1486 					struct smc_clc_msg_proposal *pclc,
1487 					struct smc_init_info *ini)
1488 {
1489 	struct smc_clc_smcd_v2_extension *smcd_v2_ext;
1490 	struct smc_clc_v2_extension *smc_v2_ext;
1491 	struct smc_clc_msg_smcd *pclc_smcd;
1492 	unsigned int matches = 0;
1493 	u8 smcd_version;
1494 	u8 *eid = NULL;
1495 	int i, rc;
1496 
1497 	if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
1498 		goto not_found;
1499 
1500 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
1501 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
1502 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
1503 	if (!smcd_v2_ext ||
1504 	    !smc_v2_ext->hdr.flag.seid) { /* no system EID support for SMCD */
1505 		smc_find_ism_store_rc(SMC_CLC_DECL_NOSEID, ini);
1506 		goto not_found;
1507 	}
1508 
1509 	mutex_lock(&smcd_dev_list.mutex);
1510 	if (pclc_smcd->ism.chid)
1511 		/* check for ISM device matching proposed native ISM device */
1512 		smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
1513 				       ntohll(pclc_smcd->ism.gid), &matches);
1514 	for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
1515 		/* check for ISM devices matching proposed non-native ISM
1516 		 * devices
1517 		 */
1518 		smc_check_ism_v2_match(ini,
1519 				       ntohs(smcd_v2_ext->gidchid[i - 1].chid),
1520 				       ntohll(smcd_v2_ext->gidchid[i - 1].gid),
1521 				       &matches);
1522 	}
1523 	mutex_unlock(&smcd_dev_list.mutex);
1524 
1525 	if (ini->ism_dev[0]) {
1526 		smc_ism_get_system_eid(ini->ism_dev[0], &eid);
1527 		if (memcmp(eid, smcd_v2_ext->system_eid, SMC_MAX_EID_LEN))
1528 			goto not_found;
1529 	} else {
1530 		goto not_found;
1531 	}
1532 
1533 	/* separate - outside the smcd_dev_list.lock */
1534 	smcd_version = ini->smcd_version;
1535 	for (i = 0; i < matches; i++) {
1536 		ini->smcd_version = SMC_V2;
1537 		ini->is_smcd = true;
1538 		ini->ism_selected = i;
1539 		rc = smc_listen_ism_init(new_smc, ini);
1540 		if (rc) {
1541 			smc_find_ism_store_rc(rc, ini);
1542 			/* try next active ISM device */
1543 			continue;
1544 		}
1545 		return; /* matching and usable V2 ISM device found */
1546 	}
1547 	/* no V2 ISM device could be initialized */
1548 	ini->smcd_version = smcd_version;	/* restore original value */
1549 
1550 not_found:
1551 	ini->smcd_version &= ~SMC_V2;
1552 	ini->ism_dev[0] = NULL;
1553 	ini->is_smcd = false;
1554 }
1555 
1556 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
1557 					struct smc_clc_msg_proposal *pclc,
1558 					struct smc_init_info *ini)
1559 {
1560 	struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
1561 	int rc = 0;
1562 
1563 	/* check if ISM V1 is available */
1564 	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
1565 		goto not_found;
1566 	ini->is_smcd = true; /* prepare ISM check */
1567 	ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
1568 	rc = smc_find_ism_device(new_smc, ini);
1569 	if (rc)
1570 		goto not_found;
1571 	ini->ism_selected = 0;
1572 	rc = smc_listen_ism_init(new_smc, ini);
1573 	if (!rc)
1574 		return;		/* V1 ISM device found */
1575 
1576 not_found:
1577 	smc_find_ism_store_rc(rc, ini);
1578 	ini->ism_dev[0] = NULL;
1579 	ini->is_smcd = false;
1580 }
1581 
1582 /* listen worker: register buffers */
1583 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
1584 {
1585 	struct smc_connection *conn = &new_smc->conn;
1586 
1587 	if (!local_first) {
1588 		if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
1589 			return SMC_CLC_DECL_ERR_REGRMB;
1590 	}
1591 	smc_rmb_sync_sg_for_device(&new_smc->conn);
1592 
1593 	return 0;
1594 }
1595 
1596 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
1597 					struct smc_clc_msg_proposal *pclc,
1598 					struct smc_init_info *ini)
1599 {
1600 	int rc;
1601 
1602 	if (!smcr_indicated(ini->smc_type_v1))
1603 		return SMC_CLC_DECL_NOSMCDEV;
1604 
1605 	/* prepare RDMA check */
1606 	ini->ib_lcl = &pclc->lcl;
1607 	rc = smc_find_rdma_device(new_smc, ini);
1608 	if (rc) {
1609 		/* no RDMA device found */
1610 		if (ini->smc_type_v1 == SMC_TYPE_B)
1611 			/* neither ISM nor RDMA device found */
1612 			rc = SMC_CLC_DECL_NOSMCDEV;
1613 		return rc;
1614 	}
1615 	rc = smc_listen_rdma_init(new_smc, ini);
1616 	if (rc)
1617 		return rc;
1618 	return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
1619 }
1620 
1621 /* determine the local device matching to proposal */
1622 static int smc_listen_find_device(struct smc_sock *new_smc,
1623 				  struct smc_clc_msg_proposal *pclc,
1624 				  struct smc_init_info *ini)
1625 {
1626 	int rc;
1627 
1628 	/* check for ISM device matching V2 proposed device */
1629 	smc_find_ism_v2_device_serv(new_smc, pclc, ini);
1630 	if (ini->ism_dev[0])
1631 		return 0;
1632 
1633 	if (!(ini->smcd_version & SMC_V1))
1634 		return ini->rc ?: SMC_CLC_DECL_NOSMCD2DEV;
1635 
1636 	/* check for matching IP prefix and subnet length */
1637 	rc = smc_listen_prfx_check(new_smc, pclc);
1638 	if (rc)
1639 		return ini->rc ?: rc;
1640 
1641 	/* get vlan id from IP device */
1642 	if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
1643 		return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
1644 
1645 	/* check for ISM device matching V1 proposed device */
1646 	smc_find_ism_v1_device_serv(new_smc, pclc, ini);
1647 	if (ini->ism_dev[0])
1648 		return 0;
1649 
1650 	if (pclc->hdr.typev1 == SMC_TYPE_D)
1651 		/* skip RDMA and decline */
1652 		return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
1653 
1654 	/* check if RDMA is available */
1655 	rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
1656 	smc_find_ism_store_rc(rc, ini);
1657 
1658 	return (!rc) ? 0 : ini->rc;
1659 }
1660 
1661 /* listen worker: finish RDMA setup */
1662 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
1663 				  struct smc_clc_msg_accept_confirm *cclc,
1664 				  bool local_first)
1665 {
1666 	struct smc_link *link = new_smc->conn.lnk;
1667 	int reason_code = 0;
1668 
1669 	if (local_first)
1670 		smc_link_save_peer_info(link, cclc);
1671 
1672 	if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
1673 		return SMC_CLC_DECL_ERR_RTOK;
1674 
1675 	if (local_first) {
1676 		if (smc_ib_ready_link(link))
1677 			return SMC_CLC_DECL_ERR_RDYLNK;
1678 		/* QP confirmation over RoCE fabric */
1679 		smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
1680 		reason_code = smcr_serv_conf_first_link(new_smc);
1681 		smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
1682 	}
1683 	return reason_code;
1684 }
1685 
1686 /* setup for connection of server */
1687 static void smc_listen_work(struct work_struct *work)
1688 {
1689 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
1690 						smc_listen_work);
1691 	u8 version = smc_ism_v2_capable ? SMC_V2 : SMC_V1;
1692 	struct socket *newclcsock = new_smc->clcsock;
1693 	struct smc_clc_msg_accept_confirm *cclc;
1694 	struct smc_clc_msg_proposal_area *buf;
1695 	struct smc_clc_msg_proposal *pclc;
1696 	struct smc_init_info *ini = NULL;
1697 	int rc = 0;
1698 
1699 	if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
1700 		return smc_listen_out_err(new_smc);
1701 
1702 	if (new_smc->use_fallback) {
1703 		smc_listen_out_connected(new_smc);
1704 		return;
1705 	}
1706 
1707 	/* check if peer is smc capable */
1708 	if (!tcp_sk(newclcsock->sk)->syn_smc) {
1709 		smc_switch_to_fallback(new_smc);
1710 		new_smc->fallback_rsn = SMC_CLC_DECL_PEERNOSMC;
1711 		smc_listen_out_connected(new_smc);
1712 		return;
1713 	}
1714 
1715 	/* do inband token exchange -
1716 	 * wait for and receive SMC Proposal CLC message
1717 	 */
1718 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
1719 	if (!buf) {
1720 		rc = SMC_CLC_DECL_MEM;
1721 		goto out_decl;
1722 	}
1723 	pclc = (struct smc_clc_msg_proposal *)buf;
1724 	rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
1725 			      SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
1726 	if (rc)
1727 		goto out_decl;
1728 	version = pclc->hdr.version == SMC_V1 ? SMC_V1 : version;
1729 
1730 	/* IPSec connections opt out of SMC optimizations */
1731 	if (using_ipsec(new_smc)) {
1732 		rc = SMC_CLC_DECL_IPSEC;
1733 		goto out_decl;
1734 	}
1735 
1736 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1737 	if (!ini) {
1738 		rc = SMC_CLC_DECL_MEM;
1739 		goto out_decl;
1740 	}
1741 
1742 	/* initial version checking */
1743 	rc = smc_listen_v2_check(new_smc, pclc, ini);
1744 	if (rc)
1745 		goto out_decl;
1746 
1747 	mutex_lock(&smc_server_lgr_pending);
1748 	smc_close_init(new_smc);
1749 	smc_rx_init(new_smc);
1750 	smc_tx_init(new_smc);
1751 
1752 	/* determine ISM or RoCE device used for connection */
1753 	rc = smc_listen_find_device(new_smc, pclc, ini);
1754 	if (rc)
1755 		goto out_unlock;
1756 
1757 	/* send SMC Accept CLC message */
1758 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
1759 				 ini->smcd_version == SMC_V2 ? SMC_V2 : SMC_V1);
1760 	if (rc)
1761 		goto out_unlock;
1762 
1763 	/* SMC-D does not need this lock any more */
1764 	if (ini->is_smcd)
1765 		mutex_unlock(&smc_server_lgr_pending);
1766 
1767 	/* receive SMC Confirm CLC message */
1768 	memset(buf, 0, sizeof(*buf));
1769 	cclc = (struct smc_clc_msg_accept_confirm *)buf;
1770 	rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
1771 			      SMC_CLC_CONFIRM, CLC_WAIT_TIME);
1772 	if (rc) {
1773 		if (!ini->is_smcd)
1774 			goto out_unlock;
1775 		goto out_decl;
1776 	}
1777 
1778 	/* finish worker */
1779 	if (!ini->is_smcd) {
1780 		rc = smc_listen_rdma_finish(new_smc, cclc,
1781 					    ini->first_contact_local);
1782 		if (rc)
1783 			goto out_unlock;
1784 		mutex_unlock(&smc_server_lgr_pending);
1785 	}
1786 	smc_conn_save_peer_info(new_smc, cclc);
1787 	smc_listen_out_connected(new_smc);
1788 	goto out_free;
1789 
1790 out_unlock:
1791 	mutex_unlock(&smc_server_lgr_pending);
1792 out_decl:
1793 	smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
1794 			   version);
1795 out_free:
1796 	kfree(ini);
1797 	kfree(buf);
1798 }
1799 
1800 static void smc_tcp_listen_work(struct work_struct *work)
1801 {
1802 	struct smc_sock *lsmc = container_of(work, struct smc_sock,
1803 					     tcp_listen_work);
1804 	struct sock *lsk = &lsmc->sk;
1805 	struct smc_sock *new_smc;
1806 	int rc = 0;
1807 
1808 	lock_sock(lsk);
1809 	while (lsk->sk_state == SMC_LISTEN) {
1810 		rc = smc_clcsock_accept(lsmc, &new_smc);
1811 		if (rc) /* clcsock accept queue empty or error */
1812 			goto out;
1813 		if (!new_smc)
1814 			continue;
1815 
1816 		new_smc->listen_smc = lsmc;
1817 		new_smc->use_fallback = lsmc->use_fallback;
1818 		new_smc->fallback_rsn = lsmc->fallback_rsn;
1819 		sock_hold(lsk); /* sock_put in smc_listen_work */
1820 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
1821 		smc_copy_sock_settings_to_smc(new_smc);
1822 		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
1823 		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
1824 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
1825 		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
1826 			sock_put(&new_smc->sk);
1827 	}
1828 
1829 out:
1830 	release_sock(lsk);
1831 	sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
1832 }
1833 
1834 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
1835 {
1836 	struct smc_sock *lsmc;
1837 
1838 	lsmc = (struct smc_sock *)
1839 	       ((uintptr_t)listen_clcsock->sk_user_data & ~SK_USER_DATA_NOCOPY);
1840 	if (!lsmc)
1841 		return;
1842 	lsmc->clcsk_data_ready(listen_clcsock);
1843 	if (lsmc->sk.sk_state == SMC_LISTEN) {
1844 		sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
1845 		if (!queue_work(smc_hs_wq, &lsmc->tcp_listen_work))
1846 			sock_put(&lsmc->sk);
1847 	}
1848 }
1849 
1850 static int smc_listen(struct socket *sock, int backlog)
1851 {
1852 	struct sock *sk = sock->sk;
1853 	struct smc_sock *smc;
1854 	int rc;
1855 
1856 	smc = smc_sk(sk);
1857 	lock_sock(sk);
1858 
1859 	rc = -EINVAL;
1860 	if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
1861 	    smc->connect_nonblock)
1862 		goto out;
1863 
1864 	rc = 0;
1865 	if (sk->sk_state == SMC_LISTEN) {
1866 		sk->sk_max_ack_backlog = backlog;
1867 		goto out;
1868 	}
1869 	/* some socket options are handled in core, so we could not apply
1870 	 * them to the clc socket -- copy smc socket options to clc socket
1871 	 */
1872 	smc_copy_sock_settings_to_clc(smc);
1873 	if (!smc->use_fallback)
1874 		tcp_sk(smc->clcsock->sk)->syn_smc = 1;
1875 
1876 	/* save original sk_data_ready function and establish
1877 	 * smc-specific sk_data_ready function
1878 	 */
1879 	smc->clcsk_data_ready = smc->clcsock->sk->sk_data_ready;
1880 	smc->clcsock->sk->sk_data_ready = smc_clcsock_data_ready;
1881 	smc->clcsock->sk->sk_user_data =
1882 		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
1883 	rc = kernel_listen(smc->clcsock, backlog);
1884 	if (rc)
1885 		goto out;
1886 	sk->sk_max_ack_backlog = backlog;
1887 	sk->sk_ack_backlog = 0;
1888 	sk->sk_state = SMC_LISTEN;
1889 
1890 out:
1891 	release_sock(sk);
1892 	return rc;
1893 }
1894 
1895 static int smc_accept(struct socket *sock, struct socket *new_sock,
1896 		      int flags, bool kern)
1897 {
1898 	struct sock *sk = sock->sk, *nsk;
1899 	DECLARE_WAITQUEUE(wait, current);
1900 	struct smc_sock *lsmc;
1901 	long timeo;
1902 	int rc = 0;
1903 
1904 	lsmc = smc_sk(sk);
1905 	sock_hold(sk); /* sock_put below */
1906 	lock_sock(sk);
1907 
1908 	if (lsmc->sk.sk_state != SMC_LISTEN) {
1909 		rc = -EINVAL;
1910 		release_sock(sk);
1911 		goto out;
1912 	}
1913 
1914 	/* Wait for an incoming connection */
1915 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
1916 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
1917 	while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
1918 		set_current_state(TASK_INTERRUPTIBLE);
1919 		if (!timeo) {
1920 			rc = -EAGAIN;
1921 			break;
1922 		}
1923 		release_sock(sk);
1924 		timeo = schedule_timeout(timeo);
1925 		/* wakeup by sk_data_ready in smc_listen_work() */
1926 		sched_annotate_sleep();
1927 		lock_sock(sk);
1928 		if (signal_pending(current)) {
1929 			rc = sock_intr_errno(timeo);
1930 			break;
1931 		}
1932 	}
1933 	set_current_state(TASK_RUNNING);
1934 	remove_wait_queue(sk_sleep(sk), &wait);
1935 
1936 	if (!rc)
1937 		rc = sock_error(nsk);
1938 	release_sock(sk);
1939 	if (rc)
1940 		goto out;
1941 
1942 	if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
1943 		/* wait till data arrives on the socket */
1944 		timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
1945 								MSEC_PER_SEC);
1946 		if (smc_sk(nsk)->use_fallback) {
1947 			struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
1948 
1949 			lock_sock(clcsk);
1950 			if (skb_queue_empty(&clcsk->sk_receive_queue))
1951 				sk_wait_data(clcsk, &timeo, NULL);
1952 			release_sock(clcsk);
1953 		} else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
1954 			lock_sock(nsk);
1955 			smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
1956 			release_sock(nsk);
1957 		}
1958 	}
1959 
1960 out:
1961 	sock_put(sk); /* sock_hold above */
1962 	return rc;
1963 }
1964 
1965 static int smc_getname(struct socket *sock, struct sockaddr *addr,
1966 		       int peer)
1967 {
1968 	struct smc_sock *smc;
1969 
1970 	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
1971 	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
1972 		return -ENOTCONN;
1973 
1974 	smc = smc_sk(sock->sk);
1975 
1976 	return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
1977 }
1978 
1979 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1980 {
1981 	struct sock *sk = sock->sk;
1982 	struct smc_sock *smc;
1983 	int rc = -EPIPE;
1984 
1985 	smc = smc_sk(sk);
1986 	lock_sock(sk);
1987 	if ((sk->sk_state != SMC_ACTIVE) &&
1988 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
1989 	    (sk->sk_state != SMC_INIT))
1990 		goto out;
1991 
1992 	if (msg->msg_flags & MSG_FASTOPEN) {
1993 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
1994 			smc_switch_to_fallback(smc);
1995 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
1996 		} else {
1997 			rc = -EINVAL;
1998 			goto out;
1999 		}
2000 	}
2001 
2002 	if (smc->use_fallback)
2003 		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
2004 	else
2005 		rc = smc_tx_sendmsg(smc, msg, len);
2006 out:
2007 	release_sock(sk);
2008 	return rc;
2009 }
2010 
2011 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2012 		       int flags)
2013 {
2014 	struct sock *sk = sock->sk;
2015 	struct smc_sock *smc;
2016 	int rc = -ENOTCONN;
2017 
2018 	smc = smc_sk(sk);
2019 	lock_sock(sk);
2020 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2021 		/* socket was connected before, no more data to read */
2022 		rc = 0;
2023 		goto out;
2024 	}
2025 	if ((sk->sk_state == SMC_INIT) ||
2026 	    (sk->sk_state == SMC_LISTEN) ||
2027 	    (sk->sk_state == SMC_CLOSED))
2028 		goto out;
2029 
2030 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2031 		rc = 0;
2032 		goto out;
2033 	}
2034 
2035 	if (smc->use_fallback) {
2036 		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
2037 	} else {
2038 		msg->msg_namelen = 0;
2039 		rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
2040 	}
2041 
2042 out:
2043 	release_sock(sk);
2044 	return rc;
2045 }
2046 
2047 static __poll_t smc_accept_poll(struct sock *parent)
2048 {
2049 	struct smc_sock *isk = smc_sk(parent);
2050 	__poll_t mask = 0;
2051 
2052 	spin_lock(&isk->accept_q_lock);
2053 	if (!list_empty(&isk->accept_q))
2054 		mask = EPOLLIN | EPOLLRDNORM;
2055 	spin_unlock(&isk->accept_q_lock);
2056 
2057 	return mask;
2058 }
2059 
2060 static __poll_t smc_poll(struct file *file, struct socket *sock,
2061 			     poll_table *wait)
2062 {
2063 	struct sock *sk = sock->sk;
2064 	struct smc_sock *smc;
2065 	__poll_t mask = 0;
2066 
2067 	if (!sk)
2068 		return EPOLLNVAL;
2069 
2070 	smc = smc_sk(sock->sk);
2071 	if (smc->use_fallback) {
2072 		/* delegate to CLC child sock */
2073 		mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
2074 		sk->sk_err = smc->clcsock->sk->sk_err;
2075 	} else {
2076 		if (sk->sk_state != SMC_CLOSED)
2077 			sock_poll_wait(file, sock, wait);
2078 		if (sk->sk_err)
2079 			mask |= EPOLLERR;
2080 		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
2081 		    (sk->sk_state == SMC_CLOSED))
2082 			mask |= EPOLLHUP;
2083 		if (sk->sk_state == SMC_LISTEN) {
2084 			/* woken up by sk_data_ready in smc_listen_work() */
2085 			mask |= smc_accept_poll(sk);
2086 		} else if (smc->use_fallback) { /* as result of connect_work()*/
2087 			mask |= smc->clcsock->ops->poll(file, smc->clcsock,
2088 							   wait);
2089 			sk->sk_err = smc->clcsock->sk->sk_err;
2090 		} else {
2091 			if ((sk->sk_state != SMC_INIT &&
2092 			     atomic_read(&smc->conn.sndbuf_space)) ||
2093 			    sk->sk_shutdown & SEND_SHUTDOWN) {
2094 				mask |= EPOLLOUT | EPOLLWRNORM;
2095 			} else {
2096 				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2097 				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2098 			}
2099 			if (atomic_read(&smc->conn.bytes_to_rcv))
2100 				mask |= EPOLLIN | EPOLLRDNORM;
2101 			if (sk->sk_shutdown & RCV_SHUTDOWN)
2102 				mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
2103 			if (sk->sk_state == SMC_APPCLOSEWAIT1)
2104 				mask |= EPOLLIN;
2105 			if (smc->conn.urg_state == SMC_URG_VALID)
2106 				mask |= EPOLLPRI;
2107 		}
2108 	}
2109 
2110 	return mask;
2111 }
2112 
2113 static int smc_shutdown(struct socket *sock, int how)
2114 {
2115 	struct sock *sk = sock->sk;
2116 	struct smc_sock *smc;
2117 	int rc = -EINVAL;
2118 	int rc1 = 0;
2119 
2120 	smc = smc_sk(sk);
2121 
2122 	if ((how < SHUT_RD) || (how > SHUT_RDWR))
2123 		return rc;
2124 
2125 	lock_sock(sk);
2126 
2127 	rc = -ENOTCONN;
2128 	if ((sk->sk_state != SMC_ACTIVE) &&
2129 	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
2130 	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
2131 	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
2132 	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
2133 	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
2134 		goto out;
2135 	if (smc->use_fallback) {
2136 		rc = kernel_sock_shutdown(smc->clcsock, how);
2137 		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
2138 		if (sk->sk_shutdown == SHUTDOWN_MASK)
2139 			sk->sk_state = SMC_CLOSED;
2140 		goto out;
2141 	}
2142 	switch (how) {
2143 	case SHUT_RDWR:		/* shutdown in both directions */
2144 		rc = smc_close_active(smc);
2145 		break;
2146 	case SHUT_WR:
2147 		rc = smc_close_shutdown_write(smc);
2148 		break;
2149 	case SHUT_RD:
2150 		rc = 0;
2151 		/* nothing more to do because peer is not involved */
2152 		break;
2153 	}
2154 	if (smc->clcsock)
2155 		rc1 = kernel_sock_shutdown(smc->clcsock, how);
2156 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
2157 	sk->sk_shutdown |= how + 1;
2158 
2159 out:
2160 	release_sock(sk);
2161 	return rc ? rc : rc1;
2162 }
2163 
2164 static int smc_setsockopt(struct socket *sock, int level, int optname,
2165 			  sockptr_t optval, unsigned int optlen)
2166 {
2167 	struct sock *sk = sock->sk;
2168 	struct smc_sock *smc;
2169 	int val, rc;
2170 
2171 	smc = smc_sk(sk);
2172 
2173 	/* generic setsockopts reaching us here always apply to the
2174 	 * CLC socket
2175 	 */
2176 	if (unlikely(!smc->clcsock->ops->setsockopt))
2177 		rc = -EOPNOTSUPP;
2178 	else
2179 		rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
2180 						   optval, optlen);
2181 	if (smc->clcsock->sk->sk_err) {
2182 		sk->sk_err = smc->clcsock->sk->sk_err;
2183 		sk->sk_error_report(sk);
2184 	}
2185 
2186 	if (optlen < sizeof(int))
2187 		return -EINVAL;
2188 	if (copy_from_sockptr(&val, optval, sizeof(int)))
2189 		return -EFAULT;
2190 
2191 	lock_sock(sk);
2192 	if (rc || smc->use_fallback)
2193 		goto out;
2194 	switch (optname) {
2195 	case TCP_ULP:
2196 	case TCP_FASTOPEN:
2197 	case TCP_FASTOPEN_CONNECT:
2198 	case TCP_FASTOPEN_KEY:
2199 	case TCP_FASTOPEN_NO_COOKIE:
2200 		/* option not supported by SMC */
2201 		if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
2202 			smc_switch_to_fallback(smc);
2203 			smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
2204 		} else {
2205 			rc = -EINVAL;
2206 		}
2207 		break;
2208 	case TCP_NODELAY:
2209 		if (sk->sk_state != SMC_INIT &&
2210 		    sk->sk_state != SMC_LISTEN &&
2211 		    sk->sk_state != SMC_CLOSED) {
2212 			if (val)
2213 				mod_delayed_work(smc->conn.lgr->tx_wq,
2214 						 &smc->conn.tx_work, 0);
2215 		}
2216 		break;
2217 	case TCP_CORK:
2218 		if (sk->sk_state != SMC_INIT &&
2219 		    sk->sk_state != SMC_LISTEN &&
2220 		    sk->sk_state != SMC_CLOSED) {
2221 			if (!val)
2222 				mod_delayed_work(smc->conn.lgr->tx_wq,
2223 						 &smc->conn.tx_work, 0);
2224 		}
2225 		break;
2226 	case TCP_DEFER_ACCEPT:
2227 		smc->sockopt_defer_accept = val;
2228 		break;
2229 	default:
2230 		break;
2231 	}
2232 out:
2233 	release_sock(sk);
2234 
2235 	return rc;
2236 }
2237 
2238 static int smc_getsockopt(struct socket *sock, int level, int optname,
2239 			  char __user *optval, int __user *optlen)
2240 {
2241 	struct smc_sock *smc;
2242 
2243 	smc = smc_sk(sock->sk);
2244 	/* socket options apply to the CLC socket */
2245 	if (unlikely(!smc->clcsock->ops->getsockopt))
2246 		return -EOPNOTSUPP;
2247 	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
2248 					     optval, optlen);
2249 }
2250 
2251 static int smc_ioctl(struct socket *sock, unsigned int cmd,
2252 		     unsigned long arg)
2253 {
2254 	union smc_host_cursor cons, urg;
2255 	struct smc_connection *conn;
2256 	struct smc_sock *smc;
2257 	int answ;
2258 
2259 	smc = smc_sk(sock->sk);
2260 	conn = &smc->conn;
2261 	lock_sock(&smc->sk);
2262 	if (smc->use_fallback) {
2263 		if (!smc->clcsock) {
2264 			release_sock(&smc->sk);
2265 			return -EBADF;
2266 		}
2267 		answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
2268 		release_sock(&smc->sk);
2269 		return answ;
2270 	}
2271 	switch (cmd) {
2272 	case SIOCINQ: /* same as FIONREAD */
2273 		if (smc->sk.sk_state == SMC_LISTEN) {
2274 			release_sock(&smc->sk);
2275 			return -EINVAL;
2276 		}
2277 		if (smc->sk.sk_state == SMC_INIT ||
2278 		    smc->sk.sk_state == SMC_CLOSED)
2279 			answ = 0;
2280 		else
2281 			answ = atomic_read(&smc->conn.bytes_to_rcv);
2282 		break;
2283 	case SIOCOUTQ:
2284 		/* output queue size (not send + not acked) */
2285 		if (smc->sk.sk_state == SMC_LISTEN) {
2286 			release_sock(&smc->sk);
2287 			return -EINVAL;
2288 		}
2289 		if (smc->sk.sk_state == SMC_INIT ||
2290 		    smc->sk.sk_state == SMC_CLOSED)
2291 			answ = 0;
2292 		else
2293 			answ = smc->conn.sndbuf_desc->len -
2294 					atomic_read(&smc->conn.sndbuf_space);
2295 		break;
2296 	case SIOCOUTQNSD:
2297 		/* output queue size (not send only) */
2298 		if (smc->sk.sk_state == SMC_LISTEN) {
2299 			release_sock(&smc->sk);
2300 			return -EINVAL;
2301 		}
2302 		if (smc->sk.sk_state == SMC_INIT ||
2303 		    smc->sk.sk_state == SMC_CLOSED)
2304 			answ = 0;
2305 		else
2306 			answ = smc_tx_prepared_sends(&smc->conn);
2307 		break;
2308 	case SIOCATMARK:
2309 		if (smc->sk.sk_state == SMC_LISTEN) {
2310 			release_sock(&smc->sk);
2311 			return -EINVAL;
2312 		}
2313 		if (smc->sk.sk_state == SMC_INIT ||
2314 		    smc->sk.sk_state == SMC_CLOSED) {
2315 			answ = 0;
2316 		} else {
2317 			smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
2318 			smc_curs_copy(&urg, &conn->urg_curs, conn);
2319 			answ = smc_curs_diff(conn->rmb_desc->len,
2320 					     &cons, &urg) == 1;
2321 		}
2322 		break;
2323 	default:
2324 		release_sock(&smc->sk);
2325 		return -ENOIOCTLCMD;
2326 	}
2327 	release_sock(&smc->sk);
2328 
2329 	return put_user(answ, (int __user *)arg);
2330 }
2331 
2332 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
2333 			    int offset, size_t size, int flags)
2334 {
2335 	struct sock *sk = sock->sk;
2336 	struct smc_sock *smc;
2337 	int rc = -EPIPE;
2338 
2339 	smc = smc_sk(sk);
2340 	lock_sock(sk);
2341 	if (sk->sk_state != SMC_ACTIVE) {
2342 		release_sock(sk);
2343 		goto out;
2344 	}
2345 	release_sock(sk);
2346 	if (smc->use_fallback)
2347 		rc = kernel_sendpage(smc->clcsock, page, offset,
2348 				     size, flags);
2349 	else
2350 		rc = sock_no_sendpage(sock, page, offset, size, flags);
2351 
2352 out:
2353 	return rc;
2354 }
2355 
2356 /* Map the affected portions of the rmbe into an spd, note the number of bytes
2357  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
2358  * updates till whenever a respective page has been fully processed.
2359  * Note that subsequent recv() calls have to wait till all splice() processing
2360  * completed.
2361  */
2362 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
2363 			       struct pipe_inode_info *pipe, size_t len,
2364 			       unsigned int flags)
2365 {
2366 	struct sock *sk = sock->sk;
2367 	struct smc_sock *smc;
2368 	int rc = -ENOTCONN;
2369 
2370 	smc = smc_sk(sk);
2371 	lock_sock(sk);
2372 	if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
2373 		/* socket was connected before, no more data to read */
2374 		rc = 0;
2375 		goto out;
2376 	}
2377 	if (sk->sk_state == SMC_INIT ||
2378 	    sk->sk_state == SMC_LISTEN ||
2379 	    sk->sk_state == SMC_CLOSED)
2380 		goto out;
2381 
2382 	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
2383 		rc = 0;
2384 		goto out;
2385 	}
2386 
2387 	if (smc->use_fallback) {
2388 		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
2389 						    pipe, len, flags);
2390 	} else {
2391 		if (*ppos) {
2392 			rc = -ESPIPE;
2393 			goto out;
2394 		}
2395 		if (flags & SPLICE_F_NONBLOCK)
2396 			flags = MSG_DONTWAIT;
2397 		else
2398 			flags = 0;
2399 		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
2400 	}
2401 out:
2402 	release_sock(sk);
2403 
2404 	return rc;
2405 }
2406 
2407 /* must look like tcp */
2408 static const struct proto_ops smc_sock_ops = {
2409 	.family		= PF_SMC,
2410 	.owner		= THIS_MODULE,
2411 	.release	= smc_release,
2412 	.bind		= smc_bind,
2413 	.connect	= smc_connect,
2414 	.socketpair	= sock_no_socketpair,
2415 	.accept		= smc_accept,
2416 	.getname	= smc_getname,
2417 	.poll		= smc_poll,
2418 	.ioctl		= smc_ioctl,
2419 	.listen		= smc_listen,
2420 	.shutdown	= smc_shutdown,
2421 	.setsockopt	= smc_setsockopt,
2422 	.getsockopt	= smc_getsockopt,
2423 	.sendmsg	= smc_sendmsg,
2424 	.recvmsg	= smc_recvmsg,
2425 	.mmap		= sock_no_mmap,
2426 	.sendpage	= smc_sendpage,
2427 	.splice_read	= smc_splice_read,
2428 };
2429 
2430 static int smc_create(struct net *net, struct socket *sock, int protocol,
2431 		      int kern)
2432 {
2433 	int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
2434 	struct smc_sock *smc;
2435 	struct sock *sk;
2436 	int rc;
2437 
2438 	rc = -ESOCKTNOSUPPORT;
2439 	if (sock->type != SOCK_STREAM)
2440 		goto out;
2441 
2442 	rc = -EPROTONOSUPPORT;
2443 	if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
2444 		goto out;
2445 
2446 	rc = -ENOBUFS;
2447 	sock->ops = &smc_sock_ops;
2448 	sk = smc_sock_alloc(net, sock, protocol);
2449 	if (!sk)
2450 		goto out;
2451 
2452 	/* create internal TCP socket for CLC handshake and fallback */
2453 	smc = smc_sk(sk);
2454 	smc->use_fallback = false; /* assume rdma capability first */
2455 	smc->fallback_rsn = 0;
2456 	rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
2457 			      &smc->clcsock);
2458 	if (rc) {
2459 		sk_common_release(sk);
2460 		goto out;
2461 	}
2462 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
2463 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
2464 
2465 out:
2466 	return rc;
2467 }
2468 
2469 static const struct net_proto_family smc_sock_family_ops = {
2470 	.family	= PF_SMC,
2471 	.owner	= THIS_MODULE,
2472 	.create	= smc_create,
2473 };
2474 
2475 unsigned int smc_net_id;
2476 
2477 static __net_init int smc_net_init(struct net *net)
2478 {
2479 	return smc_pnet_net_init(net);
2480 }
2481 
2482 static void __net_exit smc_net_exit(struct net *net)
2483 {
2484 	smc_pnet_net_exit(net);
2485 }
2486 
2487 static struct pernet_operations smc_net_ops = {
2488 	.init = smc_net_init,
2489 	.exit = smc_net_exit,
2490 	.id   = &smc_net_id,
2491 	.size = sizeof(struct smc_net),
2492 };
2493 
2494 static int __init smc_init(void)
2495 {
2496 	int rc;
2497 
2498 	rc = register_pernet_subsys(&smc_net_ops);
2499 	if (rc)
2500 		return rc;
2501 
2502 	smc_ism_init();
2503 	smc_clc_init();
2504 
2505 	rc = smc_pnet_init();
2506 	if (rc)
2507 		goto out_pernet_subsys;
2508 
2509 	rc = -ENOMEM;
2510 	smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
2511 	if (!smc_hs_wq)
2512 		goto out_pnet;
2513 
2514 	smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
2515 	if (!smc_close_wq)
2516 		goto out_alloc_hs_wq;
2517 
2518 	rc = smc_core_init();
2519 	if (rc) {
2520 		pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
2521 		goto out_alloc_wqs;
2522 	}
2523 
2524 	rc = smc_llc_init();
2525 	if (rc) {
2526 		pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
2527 		goto out_core;
2528 	}
2529 
2530 	rc = smc_cdc_init();
2531 	if (rc) {
2532 		pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
2533 		goto out_core;
2534 	}
2535 
2536 	rc = proto_register(&smc_proto, 1);
2537 	if (rc) {
2538 		pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
2539 		goto out_core;
2540 	}
2541 
2542 	rc = proto_register(&smc_proto6, 1);
2543 	if (rc) {
2544 		pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
2545 		goto out_proto;
2546 	}
2547 
2548 	rc = sock_register(&smc_sock_family_ops);
2549 	if (rc) {
2550 		pr_err("%s: sock_register fails with %d\n", __func__, rc);
2551 		goto out_proto6;
2552 	}
2553 	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
2554 	INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
2555 
2556 	rc = smc_ib_register_client();
2557 	if (rc) {
2558 		pr_err("%s: ib_register fails with %d\n", __func__, rc);
2559 		goto out_sock;
2560 	}
2561 
2562 	static_branch_enable(&tcp_have_smc);
2563 	return 0;
2564 
2565 out_sock:
2566 	sock_unregister(PF_SMC);
2567 out_proto6:
2568 	proto_unregister(&smc_proto6);
2569 out_proto:
2570 	proto_unregister(&smc_proto);
2571 out_core:
2572 	smc_core_exit();
2573 out_alloc_wqs:
2574 	destroy_workqueue(smc_close_wq);
2575 out_alloc_hs_wq:
2576 	destroy_workqueue(smc_hs_wq);
2577 out_pnet:
2578 	smc_pnet_exit();
2579 out_pernet_subsys:
2580 	unregister_pernet_subsys(&smc_net_ops);
2581 
2582 	return rc;
2583 }
2584 
2585 static void __exit smc_exit(void)
2586 {
2587 	static_branch_disable(&tcp_have_smc);
2588 	sock_unregister(PF_SMC);
2589 	smc_core_exit();
2590 	smc_ib_unregister_client();
2591 	destroy_workqueue(smc_close_wq);
2592 	destroy_workqueue(smc_hs_wq);
2593 	proto_unregister(&smc_proto6);
2594 	proto_unregister(&smc_proto);
2595 	smc_pnet_exit();
2596 	unregister_pernet_subsys(&smc_net_ops);
2597 	rcu_barrier();
2598 }
2599 
2600 module_init(smc_init);
2601 module_exit(smc_exit);
2602 
2603 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
2604 MODULE_DESCRIPTION("smc socket address family");
2605 MODULE_LICENSE("GPL");
2606 MODULE_ALIAS_NETPROTO(PF_SMC);
2607