xref: /linux/net/smc/smc_core.c (revision 4fd18fc38757217c746aa063ba9e4729814dc737)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  Basic Transport Functions exploiting Infiniband API
6  *
7  *  Copyright IBM Corp. 2016
8  *
9  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
10  */
11 
12 #include <linux/socket.h>
13 #include <linux/if_vlan.h>
14 #include <linux/random.h>
15 #include <linux/workqueue.h>
16 #include <linux/wait.h>
17 #include <linux/reboot.h>
18 #include <linux/mutex.h>
19 #include <linux/list.h>
20 #include <linux/smc.h>
21 #include <net/tcp.h>
22 #include <net/sock.h>
23 #include <rdma/ib_verbs.h>
24 #include <rdma/ib_cache.h>
25 
26 #include "smc.h"
27 #include "smc_clc.h"
28 #include "smc_core.h"
29 #include "smc_ib.h"
30 #include "smc_wr.h"
31 #include "smc_llc.h"
32 #include "smc_cdc.h"
33 #include "smc_close.h"
34 #include "smc_ism.h"
35 #include "smc_netlink.h"
36 
37 #define SMC_LGR_NUM_INCR		256
38 #define SMC_LGR_FREE_DELAY_SERV		(600 * HZ)
39 #define SMC_LGR_FREE_DELAY_CLNT		(SMC_LGR_FREE_DELAY_SERV + 10 * HZ)
40 
41 struct smc_lgr_list smc_lgr_list = {	/* established link groups */
42 	.lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
43 	.list = LIST_HEAD_INIT(smc_lgr_list.list),
44 	.num = 0,
45 };
46 
47 static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */
48 static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted);
49 
50 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
51 			 struct smc_buf_desc *buf_desc);
52 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft);
53 
54 static void smc_link_down_work(struct work_struct *work);
55 
56 /* return head of link group list and its lock for a given link group */
57 static inline struct list_head *smc_lgr_list_head(struct smc_link_group *lgr,
58 						  spinlock_t **lgr_lock)
59 {
60 	if (lgr->is_smcd) {
61 		*lgr_lock = &lgr->smcd->lgr_lock;
62 		return &lgr->smcd->lgr_list;
63 	}
64 
65 	*lgr_lock = &smc_lgr_list.lock;
66 	return &smc_lgr_list.list;
67 }
68 
69 static void smc_ibdev_cnt_inc(struct smc_link *lnk)
70 {
71 	atomic_inc(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
72 }
73 
74 static void smc_ibdev_cnt_dec(struct smc_link *lnk)
75 {
76 	atomic_dec(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
77 }
78 
79 static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
80 {
81 	/* client link group creation always follows the server link group
82 	 * creation. For client use a somewhat higher removal delay time,
83 	 * otherwise there is a risk of out-of-sync link groups.
84 	 */
85 	if (!lgr->freeing) {
86 		mod_delayed_work(system_wq, &lgr->free_work,
87 				 (!lgr->is_smcd && lgr->role == SMC_CLNT) ?
88 						SMC_LGR_FREE_DELAY_CLNT :
89 						SMC_LGR_FREE_DELAY_SERV);
90 	}
91 }
92 
93 /* Register connection's alert token in our lookup structure.
94  * To use rbtrees we have to implement our own insert core.
95  * Requires @conns_lock
96  * @smc		connection to register
97  * Returns 0 on success, != otherwise.
98  */
99 static void smc_lgr_add_alert_token(struct smc_connection *conn)
100 {
101 	struct rb_node **link, *parent = NULL;
102 	u32 token = conn->alert_token_local;
103 
104 	link = &conn->lgr->conns_all.rb_node;
105 	while (*link) {
106 		struct smc_connection *cur = rb_entry(*link,
107 					struct smc_connection, alert_node);
108 
109 		parent = *link;
110 		if (cur->alert_token_local > token)
111 			link = &parent->rb_left;
112 		else
113 			link = &parent->rb_right;
114 	}
115 	/* Put the new node there */
116 	rb_link_node(&conn->alert_node, parent, link);
117 	rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
118 }
119 
120 /* assign an SMC-R link to the connection */
121 static int smcr_lgr_conn_assign_link(struct smc_connection *conn, bool first)
122 {
123 	enum smc_link_state expected = first ? SMC_LNK_ACTIVATING :
124 				       SMC_LNK_ACTIVE;
125 	int i, j;
126 
127 	/* do link balancing */
128 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
129 		struct smc_link *lnk = &conn->lgr->lnk[i];
130 
131 		if (lnk->state != expected || lnk->link_is_asym)
132 			continue;
133 		if (conn->lgr->role == SMC_CLNT) {
134 			conn->lnk = lnk; /* temporary, SMC server assigns link*/
135 			break;
136 		}
137 		if (conn->lgr->conns_num % 2) {
138 			for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
139 				struct smc_link *lnk2;
140 
141 				lnk2 = &conn->lgr->lnk[j];
142 				if (lnk2->state == expected &&
143 				    !lnk2->link_is_asym) {
144 					conn->lnk = lnk2;
145 					break;
146 				}
147 			}
148 		}
149 		if (!conn->lnk)
150 			conn->lnk = lnk;
151 		break;
152 	}
153 	if (!conn->lnk)
154 		return SMC_CLC_DECL_NOACTLINK;
155 	atomic_inc(&conn->lnk->conn_cnt);
156 	return 0;
157 }
158 
159 /* Register connection in link group by assigning an alert token
160  * registered in a search tree.
161  * Requires @conns_lock
162  * Note that '0' is a reserved value and not assigned.
163  */
164 static int smc_lgr_register_conn(struct smc_connection *conn, bool first)
165 {
166 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
167 	static atomic_t nexttoken = ATOMIC_INIT(0);
168 	int rc;
169 
170 	if (!conn->lgr->is_smcd) {
171 		rc = smcr_lgr_conn_assign_link(conn, first);
172 		if (rc)
173 			return rc;
174 	}
175 	/* find a new alert_token_local value not yet used by some connection
176 	 * in this link group
177 	 */
178 	sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
179 	while (!conn->alert_token_local) {
180 		conn->alert_token_local = atomic_inc_return(&nexttoken);
181 		if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
182 			conn->alert_token_local = 0;
183 	}
184 	smc_lgr_add_alert_token(conn);
185 	conn->lgr->conns_num++;
186 	return 0;
187 }
188 
189 /* Unregister connection and reset the alert token of the given connection<
190  */
191 static void __smc_lgr_unregister_conn(struct smc_connection *conn)
192 {
193 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
194 	struct smc_link_group *lgr = conn->lgr;
195 
196 	rb_erase(&conn->alert_node, &lgr->conns_all);
197 	if (conn->lnk)
198 		atomic_dec(&conn->lnk->conn_cnt);
199 	lgr->conns_num--;
200 	conn->alert_token_local = 0;
201 	sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
202 }
203 
204 /* Unregister connection from lgr
205  */
206 static void smc_lgr_unregister_conn(struct smc_connection *conn)
207 {
208 	struct smc_link_group *lgr = conn->lgr;
209 
210 	if (!lgr)
211 		return;
212 	write_lock_bh(&lgr->conns_lock);
213 	if (conn->alert_token_local) {
214 		__smc_lgr_unregister_conn(conn);
215 	}
216 	write_unlock_bh(&lgr->conns_lock);
217 	conn->lgr = NULL;
218 }
219 
220 int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb)
221 {
222 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
223 	char hostname[SMC_MAX_HOSTNAME_LEN + 1];
224 	char smc_seid[SMC_MAX_EID_LEN + 1];
225 	struct smcd_dev *smcd_dev;
226 	struct nlattr *attrs;
227 	u8 *seid = NULL;
228 	u8 *host = NULL;
229 	void *nlh;
230 
231 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
232 			  &smc_gen_nl_family, NLM_F_MULTI,
233 			  SMC_NETLINK_GET_SYS_INFO);
234 	if (!nlh)
235 		goto errmsg;
236 	if (cb_ctx->pos[0])
237 		goto errout;
238 	attrs = nla_nest_start(skb, SMC_GEN_SYS_INFO);
239 	if (!attrs)
240 		goto errout;
241 	if (nla_put_u8(skb, SMC_NLA_SYS_VER, SMC_V2))
242 		goto errattr;
243 	if (nla_put_u8(skb, SMC_NLA_SYS_REL, SMC_RELEASE))
244 		goto errattr;
245 	if (nla_put_u8(skb, SMC_NLA_SYS_IS_ISM_V2, smc_ism_is_v2_capable()))
246 		goto errattr;
247 	smc_clc_get_hostname(&host);
248 	if (host) {
249 		snprintf(hostname, sizeof(hostname), "%s", host);
250 		if (nla_put_string(skb, SMC_NLA_SYS_LOCAL_HOST, hostname))
251 			goto errattr;
252 	}
253 	mutex_lock(&smcd_dev_list.mutex);
254 	smcd_dev = list_first_entry_or_null(&smcd_dev_list.list,
255 					    struct smcd_dev, list);
256 	if (smcd_dev)
257 		smc_ism_get_system_eid(smcd_dev, &seid);
258 	mutex_unlock(&smcd_dev_list.mutex);
259 	if (seid && smc_ism_is_v2_capable()) {
260 		snprintf(smc_seid, sizeof(smc_seid), "%s", seid);
261 		if (nla_put_string(skb, SMC_NLA_SYS_SEID, smc_seid))
262 			goto errattr;
263 	}
264 	nla_nest_end(skb, attrs);
265 	genlmsg_end(skb, nlh);
266 	cb_ctx->pos[0] = 1;
267 	return skb->len;
268 
269 errattr:
270 	nla_nest_cancel(skb, attrs);
271 errout:
272 	genlmsg_cancel(skb, nlh);
273 errmsg:
274 	return skb->len;
275 }
276 
277 static int smc_nl_fill_lgr(struct smc_link_group *lgr,
278 			   struct sk_buff *skb,
279 			   struct netlink_callback *cb)
280 {
281 	char smc_target[SMC_MAX_PNETID_LEN + 1];
282 	struct nlattr *attrs;
283 
284 	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCR);
285 	if (!attrs)
286 		goto errout;
287 
288 	if (nla_put_u32(skb, SMC_NLA_LGR_R_ID, *((u32 *)&lgr->id)))
289 		goto errattr;
290 	if (nla_put_u32(skb, SMC_NLA_LGR_R_CONNS_NUM, lgr->conns_num))
291 		goto errattr;
292 	if (nla_put_u8(skb, SMC_NLA_LGR_R_ROLE, lgr->role))
293 		goto errattr;
294 	if (nla_put_u8(skb, SMC_NLA_LGR_R_TYPE, lgr->type))
295 		goto errattr;
296 	if (nla_put_u8(skb, SMC_NLA_LGR_R_VLAN_ID, lgr->vlan_id))
297 		goto errattr;
298 	snprintf(smc_target, sizeof(smc_target), "%s", lgr->pnet_id);
299 	if (nla_put_string(skb, SMC_NLA_LGR_R_PNETID, smc_target))
300 		goto errattr;
301 
302 	nla_nest_end(skb, attrs);
303 	return 0;
304 errattr:
305 	nla_nest_cancel(skb, attrs);
306 errout:
307 	return -EMSGSIZE;
308 }
309 
310 static int smc_nl_fill_lgr_link(struct smc_link_group *lgr,
311 				struct smc_link *link,
312 				struct sk_buff *skb,
313 				struct netlink_callback *cb)
314 {
315 	char smc_ibname[IB_DEVICE_NAME_MAX + 1];
316 	u8 smc_gid_target[41];
317 	struct nlattr *attrs;
318 	u32 link_uid = 0;
319 	void *nlh;
320 
321 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
322 			  &smc_gen_nl_family, NLM_F_MULTI,
323 			  SMC_NETLINK_GET_LINK_SMCR);
324 	if (!nlh)
325 		goto errmsg;
326 
327 	attrs = nla_nest_start(skb, SMC_GEN_LINK_SMCR);
328 	if (!attrs)
329 		goto errout;
330 
331 	if (nla_put_u8(skb, SMC_NLA_LINK_ID, link->link_id))
332 		goto errattr;
333 	if (nla_put_u32(skb, SMC_NLA_LINK_STATE, link->state))
334 		goto errattr;
335 	if (nla_put_u32(skb, SMC_NLA_LINK_CONN_CNT,
336 			atomic_read(&link->conn_cnt)))
337 		goto errattr;
338 	if (nla_put_u8(skb, SMC_NLA_LINK_IB_PORT, link->ibport))
339 		goto errattr;
340 	if (nla_put_u32(skb, SMC_NLA_LINK_NET_DEV, link->ndev_ifidx))
341 		goto errattr;
342 	snprintf(smc_ibname, sizeof(smc_ibname), "%s", link->ibname);
343 	if (nla_put_string(skb, SMC_NLA_LINK_IB_DEV, smc_ibname))
344 		goto errattr;
345 	memcpy(&link_uid, link->link_uid, sizeof(link_uid));
346 	if (nla_put_u32(skb, SMC_NLA_LINK_UID, link_uid))
347 		goto errattr;
348 	memcpy(&link_uid, link->peer_link_uid, sizeof(link_uid));
349 	if (nla_put_u32(skb, SMC_NLA_LINK_PEER_UID, link_uid))
350 		goto errattr;
351 	memset(smc_gid_target, 0, sizeof(smc_gid_target));
352 	smc_gid_be16_convert(smc_gid_target, link->gid);
353 	if (nla_put_string(skb, SMC_NLA_LINK_GID, smc_gid_target))
354 		goto errattr;
355 	memset(smc_gid_target, 0, sizeof(smc_gid_target));
356 	smc_gid_be16_convert(smc_gid_target, link->peer_gid);
357 	if (nla_put_string(skb, SMC_NLA_LINK_PEER_GID, smc_gid_target))
358 		goto errattr;
359 
360 	nla_nest_end(skb, attrs);
361 	genlmsg_end(skb, nlh);
362 	return 0;
363 errattr:
364 	nla_nest_cancel(skb, attrs);
365 errout:
366 	genlmsg_cancel(skb, nlh);
367 errmsg:
368 	return -EMSGSIZE;
369 }
370 
371 static int smc_nl_handle_lgr(struct smc_link_group *lgr,
372 			     struct sk_buff *skb,
373 			     struct netlink_callback *cb,
374 			     bool list_links)
375 {
376 	void *nlh;
377 	int i;
378 
379 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
380 			  &smc_gen_nl_family, NLM_F_MULTI,
381 			  SMC_NETLINK_GET_LGR_SMCR);
382 	if (!nlh)
383 		goto errmsg;
384 	if (smc_nl_fill_lgr(lgr, skb, cb))
385 		goto errout;
386 
387 	genlmsg_end(skb, nlh);
388 	if (!list_links)
389 		goto out;
390 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
391 		if (!smc_link_usable(&lgr->lnk[i]))
392 			continue;
393 		if (smc_nl_fill_lgr_link(lgr, &lgr->lnk[i], skb, cb))
394 			goto errout;
395 	}
396 out:
397 	return 0;
398 
399 errout:
400 	genlmsg_cancel(skb, nlh);
401 errmsg:
402 	return -EMSGSIZE;
403 }
404 
405 static void smc_nl_fill_lgr_list(struct smc_lgr_list *smc_lgr,
406 				 struct sk_buff *skb,
407 				 struct netlink_callback *cb,
408 				 bool list_links)
409 {
410 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
411 	struct smc_link_group *lgr;
412 	int snum = cb_ctx->pos[0];
413 	int num = 0;
414 
415 	spin_lock_bh(&smc_lgr->lock);
416 	list_for_each_entry(lgr, &smc_lgr->list, list) {
417 		if (num < snum)
418 			goto next;
419 		if (smc_nl_handle_lgr(lgr, skb, cb, list_links))
420 			goto errout;
421 next:
422 		num++;
423 	}
424 errout:
425 	spin_unlock_bh(&smc_lgr->lock);
426 	cb_ctx->pos[0] = num;
427 }
428 
429 static int smc_nl_fill_smcd_lgr(struct smc_link_group *lgr,
430 				struct sk_buff *skb,
431 				struct netlink_callback *cb)
432 {
433 	char smc_host[SMC_MAX_HOSTNAME_LEN + 1];
434 	char smc_pnet[SMC_MAX_PNETID_LEN + 1];
435 	char smc_eid[SMC_MAX_EID_LEN + 1];
436 	struct nlattr *v2_attrs;
437 	struct nlattr *attrs;
438 	void *nlh;
439 
440 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
441 			  &smc_gen_nl_family, NLM_F_MULTI,
442 			  SMC_NETLINK_GET_LGR_SMCD);
443 	if (!nlh)
444 		goto errmsg;
445 
446 	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCD);
447 	if (!attrs)
448 		goto errout;
449 
450 	if (nla_put_u32(skb, SMC_NLA_LGR_D_ID, *((u32 *)&lgr->id)))
451 		goto errattr;
452 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_GID, lgr->smcd->local_gid,
453 			      SMC_NLA_LGR_D_PAD))
454 		goto errattr;
455 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_PEER_GID, lgr->peer_gid,
456 			      SMC_NLA_LGR_D_PAD))
457 		goto errattr;
458 	if (nla_put_u8(skb, SMC_NLA_LGR_D_VLAN_ID, lgr->vlan_id))
459 		goto errattr;
460 	if (nla_put_u32(skb, SMC_NLA_LGR_D_CONNS_NUM, lgr->conns_num))
461 		goto errattr;
462 	if (nla_put_u32(skb, SMC_NLA_LGR_D_CHID, smc_ism_get_chid(lgr->smcd)))
463 		goto errattr;
464 	snprintf(smc_pnet, sizeof(smc_pnet), "%s", lgr->smcd->pnetid);
465 	if (nla_put_string(skb, SMC_NLA_LGR_D_PNETID, smc_pnet))
466 		goto errattr;
467 
468 	v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_V2);
469 	if (!v2_attrs)
470 		goto errattr;
471 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_VER, lgr->smc_version))
472 		goto errv2attr;
473 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_REL, lgr->peer_smc_release))
474 		goto errv2attr;
475 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_OS, lgr->peer_os))
476 		goto errv2attr;
477 	snprintf(smc_host, sizeof(smc_host), "%s", lgr->peer_hostname);
478 	if (nla_put_string(skb, SMC_NLA_LGR_V2_PEER_HOST, smc_host))
479 		goto errv2attr;
480 	snprintf(smc_eid, sizeof(smc_eid), "%s", lgr->negotiated_eid);
481 	if (nla_put_string(skb, SMC_NLA_LGR_V2_NEG_EID, smc_eid))
482 		goto errv2attr;
483 
484 	nla_nest_end(skb, v2_attrs);
485 	nla_nest_end(skb, attrs);
486 	genlmsg_end(skb, nlh);
487 	return 0;
488 
489 errv2attr:
490 	nla_nest_cancel(skb, v2_attrs);
491 errattr:
492 	nla_nest_cancel(skb, attrs);
493 errout:
494 	genlmsg_cancel(skb, nlh);
495 errmsg:
496 	return -EMSGSIZE;
497 }
498 
499 static int smc_nl_handle_smcd_lgr(struct smcd_dev *dev,
500 				  struct sk_buff *skb,
501 				  struct netlink_callback *cb)
502 {
503 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
504 	struct smc_link_group *lgr;
505 	int snum = cb_ctx->pos[1];
506 	int rc = 0, num = 0;
507 
508 	spin_lock_bh(&dev->lgr_lock);
509 	list_for_each_entry(lgr, &dev->lgr_list, list) {
510 		if (!lgr->is_smcd)
511 			continue;
512 		if (num < snum)
513 			goto next;
514 		rc = smc_nl_fill_smcd_lgr(lgr, skb, cb);
515 		if (rc)
516 			goto errout;
517 next:
518 		num++;
519 	}
520 errout:
521 	spin_unlock_bh(&dev->lgr_lock);
522 	cb_ctx->pos[1] = num;
523 	return rc;
524 }
525 
526 static int smc_nl_fill_smcd_dev(struct smcd_dev_list *dev_list,
527 				struct sk_buff *skb,
528 				struct netlink_callback *cb)
529 {
530 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
531 	struct smcd_dev *smcd_dev;
532 	int snum = cb_ctx->pos[0];
533 	int rc = 0, num = 0;
534 
535 	mutex_lock(&dev_list->mutex);
536 	list_for_each_entry(smcd_dev, &dev_list->list, list) {
537 		if (list_empty(&smcd_dev->lgr_list))
538 			continue;
539 		if (num < snum)
540 			goto next;
541 		rc = smc_nl_handle_smcd_lgr(smcd_dev, skb, cb);
542 		if (rc)
543 			goto errout;
544 next:
545 		num++;
546 	}
547 errout:
548 	mutex_unlock(&dev_list->mutex);
549 	cb_ctx->pos[0] = num;
550 	return rc;
551 }
552 
553 int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
554 {
555 	bool list_links = false;
556 
557 	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
558 	return skb->len;
559 }
560 
561 int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb)
562 {
563 	bool list_links = true;
564 
565 	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
566 	return skb->len;
567 }
568 
569 int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
570 {
571 	smc_nl_fill_smcd_dev(&smcd_dev_list, skb, cb);
572 	return skb->len;
573 }
574 
575 void smc_lgr_cleanup_early(struct smc_connection *conn)
576 {
577 	struct smc_link_group *lgr = conn->lgr;
578 	struct list_head *lgr_list;
579 	spinlock_t *lgr_lock;
580 
581 	if (!lgr)
582 		return;
583 
584 	smc_conn_free(conn);
585 	lgr_list = smc_lgr_list_head(lgr, &lgr_lock);
586 	spin_lock_bh(lgr_lock);
587 	/* do not use this link group for new connections */
588 	if (!list_empty(lgr_list))
589 		list_del_init(lgr_list);
590 	spin_unlock_bh(lgr_lock);
591 	__smc_lgr_terminate(lgr, true);
592 }
593 
594 static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
595 {
596 	int i;
597 
598 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
599 		struct smc_link *lnk = &lgr->lnk[i];
600 
601 		if (smc_link_usable(lnk))
602 			lnk->state = SMC_LNK_INACTIVE;
603 	}
604 	wake_up_all(&lgr->llc_msg_waiter);
605 	wake_up_all(&lgr->llc_flow_waiter);
606 }
607 
608 static void smc_lgr_free(struct smc_link_group *lgr);
609 
610 static void smc_lgr_free_work(struct work_struct *work)
611 {
612 	struct smc_link_group *lgr = container_of(to_delayed_work(work),
613 						  struct smc_link_group,
614 						  free_work);
615 	spinlock_t *lgr_lock;
616 	bool conns;
617 
618 	smc_lgr_list_head(lgr, &lgr_lock);
619 	spin_lock_bh(lgr_lock);
620 	if (lgr->freeing) {
621 		spin_unlock_bh(lgr_lock);
622 		return;
623 	}
624 	read_lock_bh(&lgr->conns_lock);
625 	conns = RB_EMPTY_ROOT(&lgr->conns_all);
626 	read_unlock_bh(&lgr->conns_lock);
627 	if (!conns) { /* number of lgr connections is no longer zero */
628 		spin_unlock_bh(lgr_lock);
629 		return;
630 	}
631 	list_del_init(&lgr->list); /* remove from smc_lgr_list */
632 	lgr->freeing = 1; /* this instance does the freeing, no new schedule */
633 	spin_unlock_bh(lgr_lock);
634 	cancel_delayed_work(&lgr->free_work);
635 
636 	if (!lgr->is_smcd && !lgr->terminating)
637 		smc_llc_send_link_delete_all(lgr, true,
638 					     SMC_LLC_DEL_PROG_INIT_TERM);
639 	if (lgr->is_smcd && !lgr->terminating)
640 		smc_ism_signal_shutdown(lgr);
641 	if (!lgr->is_smcd)
642 		smcr_lgr_link_deactivate_all(lgr);
643 	smc_lgr_free(lgr);
644 }
645 
646 static void smc_lgr_terminate_work(struct work_struct *work)
647 {
648 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
649 						  terminate_work);
650 
651 	__smc_lgr_terminate(lgr, true);
652 }
653 
654 /* return next unique link id for the lgr */
655 static u8 smcr_next_link_id(struct smc_link_group *lgr)
656 {
657 	u8 link_id;
658 	int i;
659 
660 	while (1) {
661 		link_id = ++lgr->next_link_id;
662 		if (!link_id)	/* skip zero as link_id */
663 			link_id = ++lgr->next_link_id;
664 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
665 			if (smc_link_usable(&lgr->lnk[i]) &&
666 			    lgr->lnk[i].link_id == link_id)
667 				continue;
668 		}
669 		break;
670 	}
671 	return link_id;
672 }
673 
674 static void smcr_copy_dev_info_to_link(struct smc_link *link)
675 {
676 	struct smc_ib_device *smcibdev = link->smcibdev;
677 
678 	snprintf(link->ibname, sizeof(link->ibname), "%s",
679 		 smcibdev->ibdev->name);
680 	link->ndev_ifidx = smcibdev->ndev_ifidx[link->ibport - 1];
681 }
682 
683 int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
684 		   u8 link_idx, struct smc_init_info *ini)
685 {
686 	u8 rndvec[3];
687 	int rc;
688 
689 	get_device(&ini->ib_dev->ibdev->dev);
690 	atomic_inc(&ini->ib_dev->lnk_cnt);
691 	lnk->link_id = smcr_next_link_id(lgr);
692 	lnk->lgr = lgr;
693 	lnk->link_idx = link_idx;
694 	lnk->smcibdev = ini->ib_dev;
695 	lnk->ibport = ini->ib_port;
696 	smc_ibdev_cnt_inc(lnk);
697 	smcr_copy_dev_info_to_link(lnk);
698 	lnk->path_mtu = ini->ib_dev->pattr[ini->ib_port - 1].active_mtu;
699 	atomic_set(&lnk->conn_cnt, 0);
700 	smc_llc_link_set_uid(lnk);
701 	INIT_WORK(&lnk->link_down_wrk, smc_link_down_work);
702 	if (!ini->ib_dev->initialized) {
703 		rc = (int)smc_ib_setup_per_ibdev(ini->ib_dev);
704 		if (rc)
705 			goto out;
706 	}
707 	get_random_bytes(rndvec, sizeof(rndvec));
708 	lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
709 		(rndvec[2] << 16);
710 	rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
711 				  ini->vlan_id, lnk->gid, &lnk->sgid_index);
712 	if (rc)
713 		goto out;
714 	rc = smc_llc_link_init(lnk);
715 	if (rc)
716 		goto out;
717 	rc = smc_wr_alloc_link_mem(lnk);
718 	if (rc)
719 		goto clear_llc_lnk;
720 	rc = smc_ib_create_protection_domain(lnk);
721 	if (rc)
722 		goto free_link_mem;
723 	rc = smc_ib_create_queue_pair(lnk);
724 	if (rc)
725 		goto dealloc_pd;
726 	rc = smc_wr_create_link(lnk);
727 	if (rc)
728 		goto destroy_qp;
729 	lnk->state = SMC_LNK_ACTIVATING;
730 	return 0;
731 
732 destroy_qp:
733 	smc_ib_destroy_queue_pair(lnk);
734 dealloc_pd:
735 	smc_ib_dealloc_protection_domain(lnk);
736 free_link_mem:
737 	smc_wr_free_link_mem(lnk);
738 clear_llc_lnk:
739 	smc_llc_link_clear(lnk, false);
740 out:
741 	smc_ibdev_cnt_dec(lnk);
742 	put_device(&ini->ib_dev->ibdev->dev);
743 	memset(lnk, 0, sizeof(struct smc_link));
744 	lnk->state = SMC_LNK_UNUSED;
745 	if (!atomic_dec_return(&ini->ib_dev->lnk_cnt))
746 		wake_up(&ini->ib_dev->lnks_deleted);
747 	return rc;
748 }
749 
750 /* create a new SMC link group */
751 static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
752 {
753 	struct smc_link_group *lgr;
754 	struct list_head *lgr_list;
755 	struct smc_link *lnk;
756 	spinlock_t *lgr_lock;
757 	u8 link_idx;
758 	int rc = 0;
759 	int i;
760 
761 	if (ini->is_smcd && ini->vlan_id) {
762 		if (smc_ism_get_vlan(ini->ism_dev[ini->ism_selected],
763 				     ini->vlan_id)) {
764 			rc = SMC_CLC_DECL_ISMVLANERR;
765 			goto out;
766 		}
767 	}
768 
769 	lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
770 	if (!lgr) {
771 		rc = SMC_CLC_DECL_MEM;
772 		goto ism_put_vlan;
773 	}
774 	lgr->tx_wq = alloc_workqueue("smc_tx_wq-%*phN", 0, 0,
775 				     SMC_LGR_ID_SIZE, &lgr->id);
776 	if (!lgr->tx_wq) {
777 		rc = -ENOMEM;
778 		goto free_lgr;
779 	}
780 	lgr->is_smcd = ini->is_smcd;
781 	lgr->sync_err = 0;
782 	lgr->terminating = 0;
783 	lgr->freeing = 0;
784 	lgr->vlan_id = ini->vlan_id;
785 	mutex_init(&lgr->sndbufs_lock);
786 	mutex_init(&lgr->rmbs_lock);
787 	rwlock_init(&lgr->conns_lock);
788 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
789 		INIT_LIST_HEAD(&lgr->sndbufs[i]);
790 		INIT_LIST_HEAD(&lgr->rmbs[i]);
791 	}
792 	lgr->next_link_id = 0;
793 	smc_lgr_list.num += SMC_LGR_NUM_INCR;
794 	memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
795 	INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
796 	INIT_WORK(&lgr->terminate_work, smc_lgr_terminate_work);
797 	lgr->conns_all = RB_ROOT;
798 	if (ini->is_smcd) {
799 		/* SMC-D specific settings */
800 		get_device(&ini->ism_dev[ini->ism_selected]->dev);
801 		lgr->peer_gid = ini->ism_peer_gid[ini->ism_selected];
802 		lgr->smcd = ini->ism_dev[ini->ism_selected];
803 		lgr_list = &ini->ism_dev[ini->ism_selected]->lgr_list;
804 		lgr_lock = &lgr->smcd->lgr_lock;
805 		lgr->smc_version = ini->smcd_version;
806 		lgr->peer_shutdown = 0;
807 		atomic_inc(&ini->ism_dev[ini->ism_selected]->lgr_cnt);
808 	} else {
809 		/* SMC-R specific settings */
810 		lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
811 		memcpy(lgr->peer_systemid, ini->ib_lcl->id_for_peer,
812 		       SMC_SYSTEMID_LEN);
813 		memcpy(lgr->pnet_id, ini->ib_dev->pnetid[ini->ib_port - 1],
814 		       SMC_MAX_PNETID_LEN);
815 		smc_llc_lgr_init(lgr, smc);
816 
817 		link_idx = SMC_SINGLE_LINK;
818 		lnk = &lgr->lnk[link_idx];
819 		rc = smcr_link_init(lgr, lnk, link_idx, ini);
820 		if (rc)
821 			goto free_wq;
822 		lgr_list = &smc_lgr_list.list;
823 		lgr_lock = &smc_lgr_list.lock;
824 		atomic_inc(&lgr_cnt);
825 	}
826 	smc->conn.lgr = lgr;
827 	spin_lock_bh(lgr_lock);
828 	list_add_tail(&lgr->list, lgr_list);
829 	spin_unlock_bh(lgr_lock);
830 	return 0;
831 
832 free_wq:
833 	destroy_workqueue(lgr->tx_wq);
834 free_lgr:
835 	kfree(lgr);
836 ism_put_vlan:
837 	if (ini->is_smcd && ini->vlan_id)
838 		smc_ism_put_vlan(ini->ism_dev[ini->ism_selected], ini->vlan_id);
839 out:
840 	if (rc < 0) {
841 		if (rc == -ENOMEM)
842 			rc = SMC_CLC_DECL_MEM;
843 		else
844 			rc = SMC_CLC_DECL_INTERR;
845 	}
846 	return rc;
847 }
848 
849 static int smc_write_space(struct smc_connection *conn)
850 {
851 	int buffer_len = conn->peer_rmbe_size;
852 	union smc_host_cursor prod;
853 	union smc_host_cursor cons;
854 	int space;
855 
856 	smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
857 	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
858 	/* determine rx_buf space */
859 	space = buffer_len - smc_curs_diff(buffer_len, &cons, &prod);
860 	return space;
861 }
862 
863 static int smc_switch_cursor(struct smc_sock *smc, struct smc_cdc_tx_pend *pend,
864 			     struct smc_wr_buf *wr_buf)
865 {
866 	struct smc_connection *conn = &smc->conn;
867 	union smc_host_cursor cons, fin;
868 	int rc = 0;
869 	int diff;
870 
871 	smc_curs_copy(&conn->tx_curs_sent, &conn->tx_curs_fin, conn);
872 	smc_curs_copy(&fin, &conn->local_tx_ctrl_fin, conn);
873 	/* set prod cursor to old state, enforce tx_rdma_writes() */
874 	smc_curs_copy(&conn->local_tx_ctrl.prod, &fin, conn);
875 	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
876 
877 	if (smc_curs_comp(conn->peer_rmbe_size, &cons, &fin) < 0) {
878 		/* cons cursor advanced more than fin, and prod was set
879 		 * fin above, so now prod is smaller than cons. Fix that.
880 		 */
881 		diff = smc_curs_diff(conn->peer_rmbe_size, &fin, &cons);
882 		smc_curs_add(conn->sndbuf_desc->len,
883 			     &conn->tx_curs_sent, diff);
884 		smc_curs_add(conn->sndbuf_desc->len,
885 			     &conn->tx_curs_fin, diff);
886 
887 		smp_mb__before_atomic();
888 		atomic_add(diff, &conn->sndbuf_space);
889 		smp_mb__after_atomic();
890 
891 		smc_curs_add(conn->peer_rmbe_size,
892 			     &conn->local_tx_ctrl.prod, diff);
893 		smc_curs_add(conn->peer_rmbe_size,
894 			     &conn->local_tx_ctrl_fin, diff);
895 	}
896 	/* recalculate, value is used by tx_rdma_writes() */
897 	atomic_set(&smc->conn.peer_rmbe_space, smc_write_space(conn));
898 
899 	if (smc->sk.sk_state != SMC_INIT &&
900 	    smc->sk.sk_state != SMC_CLOSED) {
901 		rc = smcr_cdc_msg_send_validation(conn, pend, wr_buf);
902 		if (!rc) {
903 			queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 0);
904 			smc->sk.sk_data_ready(&smc->sk);
905 		}
906 	} else {
907 		smc_wr_tx_put_slot(conn->lnk,
908 				   (struct smc_wr_tx_pend_priv *)pend);
909 	}
910 	return rc;
911 }
912 
913 static void smc_switch_link_and_count(struct smc_connection *conn,
914 				      struct smc_link *to_lnk)
915 {
916 	atomic_dec(&conn->lnk->conn_cnt);
917 	conn->lnk = to_lnk;
918 	atomic_inc(&conn->lnk->conn_cnt);
919 }
920 
921 struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
922 				  struct smc_link *from_lnk, bool is_dev_err)
923 {
924 	struct smc_link *to_lnk = NULL;
925 	struct smc_cdc_tx_pend *pend;
926 	struct smc_connection *conn;
927 	struct smc_wr_buf *wr_buf;
928 	struct smc_sock *smc;
929 	struct rb_node *node;
930 	int i, rc = 0;
931 
932 	/* link is inactive, wake up tx waiters */
933 	smc_wr_wakeup_tx_wait(from_lnk);
934 
935 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
936 		if (!smc_link_active(&lgr->lnk[i]) || i == from_lnk->link_idx)
937 			continue;
938 		if (is_dev_err && from_lnk->smcibdev == lgr->lnk[i].smcibdev &&
939 		    from_lnk->ibport == lgr->lnk[i].ibport) {
940 			continue;
941 		}
942 		to_lnk = &lgr->lnk[i];
943 		break;
944 	}
945 	if (!to_lnk) {
946 		smc_lgr_terminate_sched(lgr);
947 		return NULL;
948 	}
949 again:
950 	read_lock_bh(&lgr->conns_lock);
951 	for (node = rb_first(&lgr->conns_all); node; node = rb_next(node)) {
952 		conn = rb_entry(node, struct smc_connection, alert_node);
953 		if (conn->lnk != from_lnk)
954 			continue;
955 		smc = container_of(conn, struct smc_sock, conn);
956 		/* conn->lnk not yet set in SMC_INIT state */
957 		if (smc->sk.sk_state == SMC_INIT)
958 			continue;
959 		if (smc->sk.sk_state == SMC_CLOSED ||
960 		    smc->sk.sk_state == SMC_PEERCLOSEWAIT1 ||
961 		    smc->sk.sk_state == SMC_PEERCLOSEWAIT2 ||
962 		    smc->sk.sk_state == SMC_APPFINCLOSEWAIT ||
963 		    smc->sk.sk_state == SMC_APPCLOSEWAIT1 ||
964 		    smc->sk.sk_state == SMC_APPCLOSEWAIT2 ||
965 		    smc->sk.sk_state == SMC_PEERFINCLOSEWAIT ||
966 		    smc->sk.sk_state == SMC_PEERABORTWAIT ||
967 		    smc->sk.sk_state == SMC_PROCESSABORT) {
968 			spin_lock_bh(&conn->send_lock);
969 			smc_switch_link_and_count(conn, to_lnk);
970 			spin_unlock_bh(&conn->send_lock);
971 			continue;
972 		}
973 		sock_hold(&smc->sk);
974 		read_unlock_bh(&lgr->conns_lock);
975 		/* pre-fetch buffer outside of send_lock, might sleep */
976 		rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend);
977 		if (rc) {
978 			smcr_link_down_cond_sched(to_lnk);
979 			return NULL;
980 		}
981 		/* avoid race with smcr_tx_sndbuf_nonempty() */
982 		spin_lock_bh(&conn->send_lock);
983 		smc_switch_link_and_count(conn, to_lnk);
984 		rc = smc_switch_cursor(smc, pend, wr_buf);
985 		spin_unlock_bh(&conn->send_lock);
986 		sock_put(&smc->sk);
987 		if (rc) {
988 			smcr_link_down_cond_sched(to_lnk);
989 			return NULL;
990 		}
991 		goto again;
992 	}
993 	read_unlock_bh(&lgr->conns_lock);
994 	return to_lnk;
995 }
996 
997 static void smcr_buf_unuse(struct smc_buf_desc *rmb_desc,
998 			   struct smc_link_group *lgr)
999 {
1000 	int rc;
1001 
1002 	if (rmb_desc->is_conf_rkey && !list_empty(&lgr->list)) {
1003 		/* unregister rmb with peer */
1004 		rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
1005 		if (!rc) {
1006 			/* protect against smc_llc_cli_rkey_exchange() */
1007 			mutex_lock(&lgr->llc_conf_mutex);
1008 			smc_llc_do_delete_rkey(lgr, rmb_desc);
1009 			rmb_desc->is_conf_rkey = false;
1010 			mutex_unlock(&lgr->llc_conf_mutex);
1011 			smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1012 		}
1013 	}
1014 
1015 	if (rmb_desc->is_reg_err) {
1016 		/* buf registration failed, reuse not possible */
1017 		mutex_lock(&lgr->rmbs_lock);
1018 		list_del(&rmb_desc->list);
1019 		mutex_unlock(&lgr->rmbs_lock);
1020 
1021 		smc_buf_free(lgr, true, rmb_desc);
1022 	} else {
1023 		rmb_desc->used = 0;
1024 	}
1025 }
1026 
1027 static void smc_buf_unuse(struct smc_connection *conn,
1028 			  struct smc_link_group *lgr)
1029 {
1030 	if (conn->sndbuf_desc)
1031 		conn->sndbuf_desc->used = 0;
1032 	if (conn->rmb_desc && lgr->is_smcd)
1033 		conn->rmb_desc->used = 0;
1034 	else if (conn->rmb_desc)
1035 		smcr_buf_unuse(conn->rmb_desc, lgr);
1036 }
1037 
1038 /* remove a finished connection from its link group */
1039 void smc_conn_free(struct smc_connection *conn)
1040 {
1041 	struct smc_link_group *lgr = conn->lgr;
1042 
1043 	if (!lgr)
1044 		return;
1045 	if (lgr->is_smcd) {
1046 		if (!list_empty(&lgr->list))
1047 			smc_ism_unset_conn(conn);
1048 		tasklet_kill(&conn->rx_tsklet);
1049 	} else {
1050 		smc_cdc_tx_dismiss_slots(conn);
1051 		if (current_work() != &conn->abort_work)
1052 			cancel_work_sync(&conn->abort_work);
1053 	}
1054 	if (!list_empty(&lgr->list)) {
1055 		smc_lgr_unregister_conn(conn);
1056 		smc_buf_unuse(conn, lgr); /* allow buffer reuse */
1057 	}
1058 
1059 	if (!lgr->conns_num)
1060 		smc_lgr_schedule_free_work(lgr);
1061 }
1062 
1063 /* unregister a link from a buf_desc */
1064 static void smcr_buf_unmap_link(struct smc_buf_desc *buf_desc, bool is_rmb,
1065 				struct smc_link *lnk)
1066 {
1067 	if (is_rmb)
1068 		buf_desc->is_reg_mr[lnk->link_idx] = false;
1069 	if (!buf_desc->is_map_ib[lnk->link_idx])
1070 		return;
1071 	if (is_rmb) {
1072 		if (buf_desc->mr_rx[lnk->link_idx]) {
1073 			smc_ib_put_memory_region(
1074 					buf_desc->mr_rx[lnk->link_idx]);
1075 			buf_desc->mr_rx[lnk->link_idx] = NULL;
1076 		}
1077 		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_FROM_DEVICE);
1078 	} else {
1079 		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_TO_DEVICE);
1080 	}
1081 	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
1082 	buf_desc->is_map_ib[lnk->link_idx] = false;
1083 }
1084 
1085 /* unmap all buffers of lgr for a deleted link */
1086 static void smcr_buf_unmap_lgr(struct smc_link *lnk)
1087 {
1088 	struct smc_link_group *lgr = lnk->lgr;
1089 	struct smc_buf_desc *buf_desc, *bf;
1090 	int i;
1091 
1092 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1093 		mutex_lock(&lgr->rmbs_lock);
1094 		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list)
1095 			smcr_buf_unmap_link(buf_desc, true, lnk);
1096 		mutex_unlock(&lgr->rmbs_lock);
1097 		mutex_lock(&lgr->sndbufs_lock);
1098 		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i],
1099 					 list)
1100 			smcr_buf_unmap_link(buf_desc, false, lnk);
1101 		mutex_unlock(&lgr->sndbufs_lock);
1102 	}
1103 }
1104 
1105 static void smcr_rtoken_clear_link(struct smc_link *lnk)
1106 {
1107 	struct smc_link_group *lgr = lnk->lgr;
1108 	int i;
1109 
1110 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1111 		lgr->rtokens[i][lnk->link_idx].rkey = 0;
1112 		lgr->rtokens[i][lnk->link_idx].dma_addr = 0;
1113 	}
1114 }
1115 
1116 /* must be called under lgr->llc_conf_mutex lock */
1117 void smcr_link_clear(struct smc_link *lnk, bool log)
1118 {
1119 	struct smc_ib_device *smcibdev;
1120 
1121 	if (!lnk->lgr || lnk->state == SMC_LNK_UNUSED)
1122 		return;
1123 	lnk->peer_qpn = 0;
1124 	smc_llc_link_clear(lnk, log);
1125 	smcr_buf_unmap_lgr(lnk);
1126 	smcr_rtoken_clear_link(lnk);
1127 	smc_ib_modify_qp_reset(lnk);
1128 	smc_wr_free_link(lnk);
1129 	smc_ib_destroy_queue_pair(lnk);
1130 	smc_ib_dealloc_protection_domain(lnk);
1131 	smc_wr_free_link_mem(lnk);
1132 	smc_ibdev_cnt_dec(lnk);
1133 	put_device(&lnk->smcibdev->ibdev->dev);
1134 	smcibdev = lnk->smcibdev;
1135 	memset(lnk, 0, sizeof(struct smc_link));
1136 	lnk->state = SMC_LNK_UNUSED;
1137 	if (!atomic_dec_return(&smcibdev->lnk_cnt))
1138 		wake_up(&smcibdev->lnks_deleted);
1139 }
1140 
1141 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
1142 			  struct smc_buf_desc *buf_desc)
1143 {
1144 	int i;
1145 
1146 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1147 		smcr_buf_unmap_link(buf_desc, is_rmb, &lgr->lnk[i]);
1148 
1149 	if (buf_desc->pages)
1150 		__free_pages(buf_desc->pages, buf_desc->order);
1151 	kfree(buf_desc);
1152 }
1153 
1154 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
1155 			  struct smc_buf_desc *buf_desc)
1156 {
1157 	if (is_dmb) {
1158 		/* restore original buf len */
1159 		buf_desc->len += sizeof(struct smcd_cdc_msg);
1160 		smc_ism_unregister_dmb(lgr->smcd, buf_desc);
1161 	} else {
1162 		kfree(buf_desc->cpu_addr);
1163 	}
1164 	kfree(buf_desc);
1165 }
1166 
1167 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
1168 			 struct smc_buf_desc *buf_desc)
1169 {
1170 	if (lgr->is_smcd)
1171 		smcd_buf_free(lgr, is_rmb, buf_desc);
1172 	else
1173 		smcr_buf_free(lgr, is_rmb, buf_desc);
1174 }
1175 
1176 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
1177 {
1178 	struct smc_buf_desc *buf_desc, *bf_desc;
1179 	struct list_head *buf_list;
1180 	int i;
1181 
1182 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1183 		if (is_rmb)
1184 			buf_list = &lgr->rmbs[i];
1185 		else
1186 			buf_list = &lgr->sndbufs[i];
1187 		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
1188 					 list) {
1189 			list_del(&buf_desc->list);
1190 			smc_buf_free(lgr, is_rmb, buf_desc);
1191 		}
1192 	}
1193 }
1194 
1195 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
1196 {
1197 	/* free send buffers */
1198 	__smc_lgr_free_bufs(lgr, false);
1199 	/* free rmbs */
1200 	__smc_lgr_free_bufs(lgr, true);
1201 }
1202 
1203 /* remove a link group */
1204 static void smc_lgr_free(struct smc_link_group *lgr)
1205 {
1206 	int i;
1207 
1208 	if (!lgr->is_smcd) {
1209 		mutex_lock(&lgr->llc_conf_mutex);
1210 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1211 			if (lgr->lnk[i].state != SMC_LNK_UNUSED)
1212 				smcr_link_clear(&lgr->lnk[i], false);
1213 		}
1214 		mutex_unlock(&lgr->llc_conf_mutex);
1215 		smc_llc_lgr_clear(lgr);
1216 	}
1217 
1218 	smc_lgr_free_bufs(lgr);
1219 	destroy_workqueue(lgr->tx_wq);
1220 	if (lgr->is_smcd) {
1221 		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
1222 		put_device(&lgr->smcd->dev);
1223 		if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
1224 			wake_up(&lgr->smcd->lgrs_deleted);
1225 	} else {
1226 		if (!atomic_dec_return(&lgr_cnt))
1227 			wake_up(&lgrs_deleted);
1228 	}
1229 	kfree(lgr);
1230 }
1231 
1232 static void smcd_unregister_all_dmbs(struct smc_link_group *lgr)
1233 {
1234 	int i;
1235 
1236 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1237 		struct smc_buf_desc *buf_desc;
1238 
1239 		list_for_each_entry(buf_desc, &lgr->rmbs[i], list) {
1240 			buf_desc->len += sizeof(struct smcd_cdc_msg);
1241 			smc_ism_unregister_dmb(lgr->smcd, buf_desc);
1242 		}
1243 	}
1244 }
1245 
1246 static void smc_sk_wake_ups(struct smc_sock *smc)
1247 {
1248 	smc->sk.sk_write_space(&smc->sk);
1249 	smc->sk.sk_data_ready(&smc->sk);
1250 	smc->sk.sk_state_change(&smc->sk);
1251 }
1252 
1253 /* kill a connection */
1254 static void smc_conn_kill(struct smc_connection *conn, bool soft)
1255 {
1256 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1257 
1258 	if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
1259 		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
1260 	else
1261 		smc_close_abort(conn);
1262 	conn->killed = 1;
1263 	smc->sk.sk_err = ECONNABORTED;
1264 	smc_sk_wake_ups(smc);
1265 	if (conn->lgr->is_smcd) {
1266 		smc_ism_unset_conn(conn);
1267 		if (soft)
1268 			tasklet_kill(&conn->rx_tsklet);
1269 		else
1270 			tasklet_unlock_wait(&conn->rx_tsklet);
1271 	} else {
1272 		smc_cdc_tx_dismiss_slots(conn);
1273 	}
1274 	smc_lgr_unregister_conn(conn);
1275 	smc_close_active_abort(smc);
1276 }
1277 
1278 static void smc_lgr_cleanup(struct smc_link_group *lgr)
1279 {
1280 	if (lgr->is_smcd) {
1281 		smc_ism_signal_shutdown(lgr);
1282 		smcd_unregister_all_dmbs(lgr);
1283 	} else {
1284 		u32 rsn = lgr->llc_termination_rsn;
1285 
1286 		if (!rsn)
1287 			rsn = SMC_LLC_DEL_PROG_INIT_TERM;
1288 		smc_llc_send_link_delete_all(lgr, false, rsn);
1289 		smcr_lgr_link_deactivate_all(lgr);
1290 	}
1291 }
1292 
1293 /* terminate link group
1294  * @soft: true if link group shutdown can take its time
1295  *	  false if immediate link group shutdown is required
1296  */
1297 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
1298 {
1299 	struct smc_connection *conn;
1300 	struct smc_sock *smc;
1301 	struct rb_node *node;
1302 
1303 	if (lgr->terminating)
1304 		return;	/* lgr already terminating */
1305 	/* cancel free_work sync, will terminate when lgr->freeing is set */
1306 	cancel_delayed_work_sync(&lgr->free_work);
1307 	lgr->terminating = 1;
1308 
1309 	/* kill remaining link group connections */
1310 	read_lock_bh(&lgr->conns_lock);
1311 	node = rb_first(&lgr->conns_all);
1312 	while (node) {
1313 		read_unlock_bh(&lgr->conns_lock);
1314 		conn = rb_entry(node, struct smc_connection, alert_node);
1315 		smc = container_of(conn, struct smc_sock, conn);
1316 		sock_hold(&smc->sk); /* sock_put below */
1317 		lock_sock(&smc->sk);
1318 		smc_conn_kill(conn, soft);
1319 		release_sock(&smc->sk);
1320 		sock_put(&smc->sk); /* sock_hold above */
1321 		read_lock_bh(&lgr->conns_lock);
1322 		node = rb_first(&lgr->conns_all);
1323 	}
1324 	read_unlock_bh(&lgr->conns_lock);
1325 	smc_lgr_cleanup(lgr);
1326 	smc_lgr_free(lgr);
1327 }
1328 
1329 /* unlink link group and schedule termination */
1330 void smc_lgr_terminate_sched(struct smc_link_group *lgr)
1331 {
1332 	spinlock_t *lgr_lock;
1333 
1334 	smc_lgr_list_head(lgr, &lgr_lock);
1335 	spin_lock_bh(lgr_lock);
1336 	if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
1337 		spin_unlock_bh(lgr_lock);
1338 		return;	/* lgr already terminating */
1339 	}
1340 	list_del_init(&lgr->list);
1341 	lgr->freeing = 1;
1342 	spin_unlock_bh(lgr_lock);
1343 	schedule_work(&lgr->terminate_work);
1344 }
1345 
1346 /* Called when peer lgr shutdown (regularly or abnormally) is received */
1347 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
1348 {
1349 	struct smc_link_group *lgr, *l;
1350 	LIST_HEAD(lgr_free_list);
1351 
1352 	/* run common cleanup function and build free list */
1353 	spin_lock_bh(&dev->lgr_lock);
1354 	list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
1355 		if ((!peer_gid || lgr->peer_gid == peer_gid) &&
1356 		    (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
1357 			if (peer_gid) /* peer triggered termination */
1358 				lgr->peer_shutdown = 1;
1359 			list_move(&lgr->list, &lgr_free_list);
1360 			lgr->freeing = 1;
1361 		}
1362 	}
1363 	spin_unlock_bh(&dev->lgr_lock);
1364 
1365 	/* cancel the regular free workers and actually free lgrs */
1366 	list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
1367 		list_del_init(&lgr->list);
1368 		schedule_work(&lgr->terminate_work);
1369 	}
1370 }
1371 
1372 /* Called when an SMCD device is removed or the smc module is unloaded */
1373 void smc_smcd_terminate_all(struct smcd_dev *smcd)
1374 {
1375 	struct smc_link_group *lgr, *lg;
1376 	LIST_HEAD(lgr_free_list);
1377 
1378 	spin_lock_bh(&smcd->lgr_lock);
1379 	list_splice_init(&smcd->lgr_list, &lgr_free_list);
1380 	list_for_each_entry(lgr, &lgr_free_list, list)
1381 		lgr->freeing = 1;
1382 	spin_unlock_bh(&smcd->lgr_lock);
1383 
1384 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1385 		list_del_init(&lgr->list);
1386 		__smc_lgr_terminate(lgr, false);
1387 	}
1388 
1389 	if (atomic_read(&smcd->lgr_cnt))
1390 		wait_event(smcd->lgrs_deleted, !atomic_read(&smcd->lgr_cnt));
1391 }
1392 
1393 /* Called when an SMCR device is removed or the smc module is unloaded.
1394  * If smcibdev is given, all SMCR link groups using this device are terminated.
1395  * If smcibdev is NULL, all SMCR link groups are terminated.
1396  */
1397 void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
1398 {
1399 	struct smc_link_group *lgr, *lg;
1400 	LIST_HEAD(lgr_free_list);
1401 	int i;
1402 
1403 	spin_lock_bh(&smc_lgr_list.lock);
1404 	if (!smcibdev) {
1405 		list_splice_init(&smc_lgr_list.list, &lgr_free_list);
1406 		list_for_each_entry(lgr, &lgr_free_list, list)
1407 			lgr->freeing = 1;
1408 	} else {
1409 		list_for_each_entry_safe(lgr, lg, &smc_lgr_list.list, list) {
1410 			for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1411 				if (lgr->lnk[i].smcibdev == smcibdev)
1412 					smcr_link_down_cond_sched(&lgr->lnk[i]);
1413 			}
1414 		}
1415 	}
1416 	spin_unlock_bh(&smc_lgr_list.lock);
1417 
1418 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1419 		list_del_init(&lgr->list);
1420 		smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_OP_INIT_TERM);
1421 		__smc_lgr_terminate(lgr, false);
1422 	}
1423 
1424 	if (smcibdev) {
1425 		if (atomic_read(&smcibdev->lnk_cnt))
1426 			wait_event(smcibdev->lnks_deleted,
1427 				   !atomic_read(&smcibdev->lnk_cnt));
1428 	} else {
1429 		if (atomic_read(&lgr_cnt))
1430 			wait_event(lgrs_deleted, !atomic_read(&lgr_cnt));
1431 	}
1432 }
1433 
1434 /* set new lgr type and clear all asymmetric link tagging */
1435 void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type)
1436 {
1437 	char *lgr_type = "";
1438 	int i;
1439 
1440 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1441 		if (smc_link_usable(&lgr->lnk[i]))
1442 			lgr->lnk[i].link_is_asym = false;
1443 	if (lgr->type == new_type)
1444 		return;
1445 	lgr->type = new_type;
1446 
1447 	switch (lgr->type) {
1448 	case SMC_LGR_NONE:
1449 		lgr_type = "NONE";
1450 		break;
1451 	case SMC_LGR_SINGLE:
1452 		lgr_type = "SINGLE";
1453 		break;
1454 	case SMC_LGR_SYMMETRIC:
1455 		lgr_type = "SYMMETRIC";
1456 		break;
1457 	case SMC_LGR_ASYMMETRIC_PEER:
1458 		lgr_type = "ASYMMETRIC_PEER";
1459 		break;
1460 	case SMC_LGR_ASYMMETRIC_LOCAL:
1461 		lgr_type = "ASYMMETRIC_LOCAL";
1462 		break;
1463 	}
1464 	pr_warn_ratelimited("smc: SMC-R lg %*phN state changed: "
1465 			    "%s, pnetid %.16s\n", SMC_LGR_ID_SIZE, &lgr->id,
1466 			    lgr_type, lgr->pnet_id);
1467 }
1468 
1469 /* set new lgr type and tag a link as asymmetric */
1470 void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
1471 			    enum smc_lgr_type new_type, int asym_lnk_idx)
1472 {
1473 	smcr_lgr_set_type(lgr, new_type);
1474 	lgr->lnk[asym_lnk_idx].link_is_asym = true;
1475 }
1476 
1477 /* abort connection, abort_work scheduled from tasklet context */
1478 static void smc_conn_abort_work(struct work_struct *work)
1479 {
1480 	struct smc_connection *conn = container_of(work,
1481 						   struct smc_connection,
1482 						   abort_work);
1483 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1484 
1485 	smc_conn_kill(conn, true);
1486 	sock_put(&smc->sk); /* sock_hold done by schedulers of abort_work */
1487 }
1488 
1489 void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
1490 {
1491 	struct smc_link_group *lgr, *n;
1492 
1493 	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1494 		struct smc_link *link;
1495 
1496 		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1497 			    SMC_MAX_PNETID_LEN) ||
1498 		    lgr->type == SMC_LGR_SYMMETRIC ||
1499 		    lgr->type == SMC_LGR_ASYMMETRIC_PEER)
1500 			continue;
1501 
1502 		/* trigger local add link processing */
1503 		link = smc_llc_usable_link(lgr);
1504 		if (link)
1505 			smc_llc_add_link_local(link);
1506 	}
1507 }
1508 
1509 /* link is down - switch connections to alternate link,
1510  * must be called under lgr->llc_conf_mutex lock
1511  */
1512 static void smcr_link_down(struct smc_link *lnk)
1513 {
1514 	struct smc_link_group *lgr = lnk->lgr;
1515 	struct smc_link *to_lnk;
1516 	int del_link_id;
1517 
1518 	if (!lgr || lnk->state == SMC_LNK_UNUSED || list_empty(&lgr->list))
1519 		return;
1520 
1521 	smc_ib_modify_qp_reset(lnk);
1522 	to_lnk = smc_switch_conns(lgr, lnk, true);
1523 	if (!to_lnk) { /* no backup link available */
1524 		smcr_link_clear(lnk, true);
1525 		return;
1526 	}
1527 	smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1528 	del_link_id = lnk->link_id;
1529 
1530 	if (lgr->role == SMC_SERV) {
1531 		/* trigger local delete link processing */
1532 		smc_llc_srv_delete_link_local(to_lnk, del_link_id);
1533 	} else {
1534 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1535 			/* another llc task is ongoing */
1536 			mutex_unlock(&lgr->llc_conf_mutex);
1537 			wait_event_timeout(lgr->llc_flow_waiter,
1538 				(list_empty(&lgr->list) ||
1539 				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
1540 				SMC_LLC_WAIT_TIME);
1541 			mutex_lock(&lgr->llc_conf_mutex);
1542 		}
1543 		if (!list_empty(&lgr->list)) {
1544 			smc_llc_send_delete_link(to_lnk, del_link_id,
1545 						 SMC_LLC_REQ, true,
1546 						 SMC_LLC_DEL_LOST_PATH);
1547 			smcr_link_clear(lnk, true);
1548 		}
1549 		wake_up(&lgr->llc_flow_waiter);	/* wake up next waiter */
1550 	}
1551 }
1552 
1553 /* must be called under lgr->llc_conf_mutex lock */
1554 void smcr_link_down_cond(struct smc_link *lnk)
1555 {
1556 	if (smc_link_downing(&lnk->state))
1557 		smcr_link_down(lnk);
1558 }
1559 
1560 /* will get the lgr->llc_conf_mutex lock */
1561 void smcr_link_down_cond_sched(struct smc_link *lnk)
1562 {
1563 	if (smc_link_downing(&lnk->state))
1564 		schedule_work(&lnk->link_down_wrk);
1565 }
1566 
1567 void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport)
1568 {
1569 	struct smc_link_group *lgr, *n;
1570 	int i;
1571 
1572 	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1573 		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1574 			    SMC_MAX_PNETID_LEN))
1575 			continue; /* lgr is not affected */
1576 		if (list_empty(&lgr->list))
1577 			continue;
1578 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1579 			struct smc_link *lnk = &lgr->lnk[i];
1580 
1581 			if (smc_link_usable(lnk) &&
1582 			    lnk->smcibdev == smcibdev && lnk->ibport == ibport)
1583 				smcr_link_down_cond_sched(lnk);
1584 		}
1585 	}
1586 }
1587 
1588 static void smc_link_down_work(struct work_struct *work)
1589 {
1590 	struct smc_link *link = container_of(work, struct smc_link,
1591 					     link_down_wrk);
1592 	struct smc_link_group *lgr = link->lgr;
1593 
1594 	if (list_empty(&lgr->list))
1595 		return;
1596 	wake_up_all(&lgr->llc_msg_waiter);
1597 	mutex_lock(&lgr->llc_conf_mutex);
1598 	smcr_link_down(link);
1599 	mutex_unlock(&lgr->llc_conf_mutex);
1600 }
1601 
1602 /* Determine vlan of internal TCP socket.
1603  * @vlan_id: address to store the determined vlan id into
1604  */
1605 int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
1606 {
1607 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
1608 	struct net_device *ndev;
1609 	int i, nest_lvl, rc = 0;
1610 
1611 	ini->vlan_id = 0;
1612 	if (!dst) {
1613 		rc = -ENOTCONN;
1614 		goto out;
1615 	}
1616 	if (!dst->dev) {
1617 		rc = -ENODEV;
1618 		goto out_rel;
1619 	}
1620 
1621 	ndev = dst->dev;
1622 	if (is_vlan_dev(ndev)) {
1623 		ini->vlan_id = vlan_dev_vlan_id(ndev);
1624 		goto out_rel;
1625 	}
1626 
1627 	rtnl_lock();
1628 	nest_lvl = ndev->lower_level;
1629 	for (i = 0; i < nest_lvl; i++) {
1630 		struct list_head *lower = &ndev->adj_list.lower;
1631 
1632 		if (list_empty(lower))
1633 			break;
1634 		lower = lower->next;
1635 		ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);
1636 		if (is_vlan_dev(ndev)) {
1637 			ini->vlan_id = vlan_dev_vlan_id(ndev);
1638 			break;
1639 		}
1640 	}
1641 	rtnl_unlock();
1642 
1643 out_rel:
1644 	dst_release(dst);
1645 out:
1646 	return rc;
1647 }
1648 
1649 static bool smcr_lgr_match(struct smc_link_group *lgr,
1650 			   struct smc_clc_msg_local *lcl,
1651 			   enum smc_lgr_role role, u32 clcqpn)
1652 {
1653 	int i;
1654 
1655 	if (memcmp(lgr->peer_systemid, lcl->id_for_peer, SMC_SYSTEMID_LEN) ||
1656 	    lgr->role != role)
1657 		return false;
1658 
1659 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1660 		if (!smc_link_active(&lgr->lnk[i]))
1661 			continue;
1662 		if ((lgr->role == SMC_SERV || lgr->lnk[i].peer_qpn == clcqpn) &&
1663 		    !memcmp(lgr->lnk[i].peer_gid, &lcl->gid, SMC_GID_SIZE) &&
1664 		    !memcmp(lgr->lnk[i].peer_mac, lcl->mac, sizeof(lcl->mac)))
1665 			return true;
1666 	}
1667 	return false;
1668 }
1669 
1670 static bool smcd_lgr_match(struct smc_link_group *lgr,
1671 			   struct smcd_dev *smcismdev, u64 peer_gid)
1672 {
1673 	return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
1674 }
1675 
1676 /* create a new SMC connection (and a new link group if necessary) */
1677 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
1678 {
1679 	struct smc_connection *conn = &smc->conn;
1680 	struct list_head *lgr_list;
1681 	struct smc_link_group *lgr;
1682 	enum smc_lgr_role role;
1683 	spinlock_t *lgr_lock;
1684 	int rc = 0;
1685 
1686 	lgr_list = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_list :
1687 				  &smc_lgr_list.list;
1688 	lgr_lock = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_lock :
1689 				  &smc_lgr_list.lock;
1690 	ini->first_contact_local = 1;
1691 	role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
1692 	if (role == SMC_CLNT && ini->first_contact_peer)
1693 		/* create new link group as well */
1694 		goto create;
1695 
1696 	/* determine if an existing link group can be reused */
1697 	spin_lock_bh(lgr_lock);
1698 	list_for_each_entry(lgr, lgr_list, list) {
1699 		write_lock_bh(&lgr->conns_lock);
1700 		if ((ini->is_smcd ?
1701 		     smcd_lgr_match(lgr, ini->ism_dev[ini->ism_selected],
1702 				    ini->ism_peer_gid[ini->ism_selected]) :
1703 		     smcr_lgr_match(lgr, ini->ib_lcl, role, ini->ib_clcqpn)) &&
1704 		    !lgr->sync_err &&
1705 		    (ini->smcd_version == SMC_V2 ||
1706 		     lgr->vlan_id == ini->vlan_id) &&
1707 		    (role == SMC_CLNT || ini->is_smcd ||
1708 		     lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) {
1709 			/* link group found */
1710 			ini->first_contact_local = 0;
1711 			conn->lgr = lgr;
1712 			rc = smc_lgr_register_conn(conn, false);
1713 			write_unlock_bh(&lgr->conns_lock);
1714 			if (!rc && delayed_work_pending(&lgr->free_work))
1715 				cancel_delayed_work(&lgr->free_work);
1716 			break;
1717 		}
1718 		write_unlock_bh(&lgr->conns_lock);
1719 	}
1720 	spin_unlock_bh(lgr_lock);
1721 	if (rc)
1722 		return rc;
1723 
1724 	if (role == SMC_CLNT && !ini->first_contact_peer &&
1725 	    ini->first_contact_local) {
1726 		/* Server reuses a link group, but Client wants to start
1727 		 * a new one
1728 		 * send out_of_sync decline, reason synchr. error
1729 		 */
1730 		return SMC_CLC_DECL_SYNCERR;
1731 	}
1732 
1733 create:
1734 	if (ini->first_contact_local) {
1735 		rc = smc_lgr_create(smc, ini);
1736 		if (rc)
1737 			goto out;
1738 		lgr = conn->lgr;
1739 		write_lock_bh(&lgr->conns_lock);
1740 		rc = smc_lgr_register_conn(conn, true);
1741 		write_unlock_bh(&lgr->conns_lock);
1742 		if (rc)
1743 			goto out;
1744 	}
1745 	conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
1746 	conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
1747 	conn->urg_state = SMC_URG_READ;
1748 	INIT_WORK(&smc->conn.abort_work, smc_conn_abort_work);
1749 	if (ini->is_smcd) {
1750 		conn->rx_off = sizeof(struct smcd_cdc_msg);
1751 		smcd_cdc_rx_init(conn); /* init tasklet for this conn */
1752 	} else {
1753 		conn->rx_off = 0;
1754 	}
1755 #ifndef KERNEL_HAS_ATOMIC64
1756 	spin_lock_init(&conn->acurs_lock);
1757 #endif
1758 
1759 out:
1760 	return rc;
1761 }
1762 
1763 /* convert the RMB size into the compressed notation - minimum 16K.
1764  * In contrast to plain ilog2, this rounds towards the next power of 2,
1765  * so the socket application gets at least its desired sndbuf / rcvbuf size.
1766  */
1767 static u8 smc_compress_bufsize(int size)
1768 {
1769 	u8 compressed;
1770 
1771 	if (size <= SMC_BUF_MIN_SIZE)
1772 		return 0;
1773 
1774 	size = (size - 1) >> 14;
1775 	compressed = ilog2(size) + 1;
1776 	if (compressed >= SMC_RMBE_SIZES)
1777 		compressed = SMC_RMBE_SIZES - 1;
1778 	return compressed;
1779 }
1780 
1781 /* convert the RMB size from compressed notation into integer */
1782 int smc_uncompress_bufsize(u8 compressed)
1783 {
1784 	u32 size;
1785 
1786 	size = 0x00000001 << (((int)compressed) + 14);
1787 	return (int)size;
1788 }
1789 
1790 /* try to reuse a sndbuf or rmb description slot for a certain
1791  * buffer size; if not available, return NULL
1792  */
1793 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
1794 					     struct mutex *lock,
1795 					     struct list_head *buf_list)
1796 {
1797 	struct smc_buf_desc *buf_slot;
1798 
1799 	mutex_lock(lock);
1800 	list_for_each_entry(buf_slot, buf_list, list) {
1801 		if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
1802 			mutex_unlock(lock);
1803 			return buf_slot;
1804 		}
1805 	}
1806 	mutex_unlock(lock);
1807 	return NULL;
1808 }
1809 
1810 /* one of the conditions for announcing a receiver's current window size is
1811  * that it "results in a minimum increase in the window size of 10% of the
1812  * receive buffer space" [RFC7609]
1813  */
1814 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
1815 {
1816 	return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
1817 }
1818 
1819 /* map an rmb buf to a link */
1820 static int smcr_buf_map_link(struct smc_buf_desc *buf_desc, bool is_rmb,
1821 			     struct smc_link *lnk)
1822 {
1823 	int rc;
1824 
1825 	if (buf_desc->is_map_ib[lnk->link_idx])
1826 		return 0;
1827 
1828 	rc = sg_alloc_table(&buf_desc->sgt[lnk->link_idx], 1, GFP_KERNEL);
1829 	if (rc)
1830 		return rc;
1831 	sg_set_buf(buf_desc->sgt[lnk->link_idx].sgl,
1832 		   buf_desc->cpu_addr, buf_desc->len);
1833 
1834 	/* map sg table to DMA address */
1835 	rc = smc_ib_buf_map_sg(lnk, buf_desc,
1836 			       is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1837 	/* SMC protocol depends on mapping to one DMA address only */
1838 	if (rc != 1) {
1839 		rc = -EAGAIN;
1840 		goto free_table;
1841 	}
1842 
1843 	/* create a new memory region for the RMB */
1844 	if (is_rmb) {
1845 		rc = smc_ib_get_memory_region(lnk->roce_pd,
1846 					      IB_ACCESS_REMOTE_WRITE |
1847 					      IB_ACCESS_LOCAL_WRITE,
1848 					      buf_desc, lnk->link_idx);
1849 		if (rc)
1850 			goto buf_unmap;
1851 		smc_ib_sync_sg_for_device(lnk, buf_desc, DMA_FROM_DEVICE);
1852 	}
1853 	buf_desc->is_map_ib[lnk->link_idx] = true;
1854 	return 0;
1855 
1856 buf_unmap:
1857 	smc_ib_buf_unmap_sg(lnk, buf_desc,
1858 			    is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1859 free_table:
1860 	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
1861 	return rc;
1862 }
1863 
1864 /* register a new rmb on IB device,
1865  * must be called under lgr->llc_conf_mutex lock
1866  */
1867 int smcr_link_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc)
1868 {
1869 	if (list_empty(&link->lgr->list))
1870 		return -ENOLINK;
1871 	if (!rmb_desc->is_reg_mr[link->link_idx]) {
1872 		/* register memory region for new rmb */
1873 		if (smc_wr_reg_send(link, rmb_desc->mr_rx[link->link_idx])) {
1874 			rmb_desc->is_reg_err = true;
1875 			return -EFAULT;
1876 		}
1877 		rmb_desc->is_reg_mr[link->link_idx] = true;
1878 	}
1879 	return 0;
1880 }
1881 
1882 static int _smcr_buf_map_lgr(struct smc_link *lnk, struct mutex *lock,
1883 			     struct list_head *lst, bool is_rmb)
1884 {
1885 	struct smc_buf_desc *buf_desc, *bf;
1886 	int rc = 0;
1887 
1888 	mutex_lock(lock);
1889 	list_for_each_entry_safe(buf_desc, bf, lst, list) {
1890 		if (!buf_desc->used)
1891 			continue;
1892 		rc = smcr_buf_map_link(buf_desc, is_rmb, lnk);
1893 		if (rc)
1894 			goto out;
1895 	}
1896 out:
1897 	mutex_unlock(lock);
1898 	return rc;
1899 }
1900 
1901 /* map all used buffers of lgr for a new link */
1902 int smcr_buf_map_lgr(struct smc_link *lnk)
1903 {
1904 	struct smc_link_group *lgr = lnk->lgr;
1905 	int i, rc = 0;
1906 
1907 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1908 		rc = _smcr_buf_map_lgr(lnk, &lgr->rmbs_lock,
1909 				       &lgr->rmbs[i], true);
1910 		if (rc)
1911 			return rc;
1912 		rc = _smcr_buf_map_lgr(lnk, &lgr->sndbufs_lock,
1913 				       &lgr->sndbufs[i], false);
1914 		if (rc)
1915 			return rc;
1916 	}
1917 	return 0;
1918 }
1919 
1920 /* register all used buffers of lgr for a new link,
1921  * must be called under lgr->llc_conf_mutex lock
1922  */
1923 int smcr_buf_reg_lgr(struct smc_link *lnk)
1924 {
1925 	struct smc_link_group *lgr = lnk->lgr;
1926 	struct smc_buf_desc *buf_desc, *bf;
1927 	int i, rc = 0;
1928 
1929 	mutex_lock(&lgr->rmbs_lock);
1930 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1931 		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list) {
1932 			if (!buf_desc->used)
1933 				continue;
1934 			rc = smcr_link_reg_rmb(lnk, buf_desc);
1935 			if (rc)
1936 				goto out;
1937 		}
1938 	}
1939 out:
1940 	mutex_unlock(&lgr->rmbs_lock);
1941 	return rc;
1942 }
1943 
1944 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
1945 						bool is_rmb, int bufsize)
1946 {
1947 	struct smc_buf_desc *buf_desc;
1948 
1949 	/* try to alloc a new buffer */
1950 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
1951 	if (!buf_desc)
1952 		return ERR_PTR(-ENOMEM);
1953 
1954 	buf_desc->order = get_order(bufsize);
1955 	buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
1956 				      __GFP_NOMEMALLOC | __GFP_COMP |
1957 				      __GFP_NORETRY | __GFP_ZERO,
1958 				      buf_desc->order);
1959 	if (!buf_desc->pages) {
1960 		kfree(buf_desc);
1961 		return ERR_PTR(-EAGAIN);
1962 	}
1963 	buf_desc->cpu_addr = (void *)page_address(buf_desc->pages);
1964 	buf_desc->len = bufsize;
1965 	return buf_desc;
1966 }
1967 
1968 /* map buf_desc on all usable links,
1969  * unused buffers stay mapped as long as the link is up
1970  */
1971 static int smcr_buf_map_usable_links(struct smc_link_group *lgr,
1972 				     struct smc_buf_desc *buf_desc, bool is_rmb)
1973 {
1974 	int i, rc = 0;
1975 
1976 	/* protect against parallel link reconfiguration */
1977 	mutex_lock(&lgr->llc_conf_mutex);
1978 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1979 		struct smc_link *lnk = &lgr->lnk[i];
1980 
1981 		if (!smc_link_usable(lnk))
1982 			continue;
1983 		if (smcr_buf_map_link(buf_desc, is_rmb, lnk)) {
1984 			rc = -ENOMEM;
1985 			goto out;
1986 		}
1987 	}
1988 out:
1989 	mutex_unlock(&lgr->llc_conf_mutex);
1990 	return rc;
1991 }
1992 
1993 #define SMCD_DMBE_SIZES		6 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
1994 
1995 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
1996 						bool is_dmb, int bufsize)
1997 {
1998 	struct smc_buf_desc *buf_desc;
1999 	int rc;
2000 
2001 	if (smc_compress_bufsize(bufsize) > SMCD_DMBE_SIZES)
2002 		return ERR_PTR(-EAGAIN);
2003 
2004 	/* try to alloc a new DMB */
2005 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2006 	if (!buf_desc)
2007 		return ERR_PTR(-ENOMEM);
2008 	if (is_dmb) {
2009 		rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
2010 		if (rc) {
2011 			kfree(buf_desc);
2012 			if (rc == -ENOMEM)
2013 				return ERR_PTR(-EAGAIN);
2014 			if (rc == -ENOSPC)
2015 				return ERR_PTR(-ENOSPC);
2016 			return ERR_PTR(-EIO);
2017 		}
2018 		buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
2019 		/* CDC header stored in buf. So, pretend it was smaller */
2020 		buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
2021 	} else {
2022 		buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
2023 					     __GFP_NOWARN | __GFP_NORETRY |
2024 					     __GFP_NOMEMALLOC);
2025 		if (!buf_desc->cpu_addr) {
2026 			kfree(buf_desc);
2027 			return ERR_PTR(-EAGAIN);
2028 		}
2029 		buf_desc->len = bufsize;
2030 	}
2031 	return buf_desc;
2032 }
2033 
2034 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
2035 {
2036 	struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
2037 	struct smc_connection *conn = &smc->conn;
2038 	struct smc_link_group *lgr = conn->lgr;
2039 	struct list_head *buf_list;
2040 	int bufsize, bufsize_short;
2041 	struct mutex *lock;	/* lock buffer list */
2042 	int sk_buf_size;
2043 
2044 	if (is_rmb)
2045 		/* use socket recv buffer size (w/o overhead) as start value */
2046 		sk_buf_size = smc->sk.sk_rcvbuf / 2;
2047 	else
2048 		/* use socket send buffer size (w/o overhead) as start value */
2049 		sk_buf_size = smc->sk.sk_sndbuf / 2;
2050 
2051 	for (bufsize_short = smc_compress_bufsize(sk_buf_size);
2052 	     bufsize_short >= 0; bufsize_short--) {
2053 
2054 		if (is_rmb) {
2055 			lock = &lgr->rmbs_lock;
2056 			buf_list = &lgr->rmbs[bufsize_short];
2057 		} else {
2058 			lock = &lgr->sndbufs_lock;
2059 			buf_list = &lgr->sndbufs[bufsize_short];
2060 		}
2061 		bufsize = smc_uncompress_bufsize(bufsize_short);
2062 		if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)
2063 			continue;
2064 
2065 		/* check for reusable slot in the link group */
2066 		buf_desc = smc_buf_get_slot(bufsize_short, lock, buf_list);
2067 		if (buf_desc) {
2068 			memset(buf_desc->cpu_addr, 0, bufsize);
2069 			break; /* found reusable slot */
2070 		}
2071 
2072 		if (is_smcd)
2073 			buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
2074 		else
2075 			buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
2076 
2077 		if (PTR_ERR(buf_desc) == -ENOMEM)
2078 			break;
2079 		if (IS_ERR(buf_desc))
2080 			continue;
2081 
2082 		buf_desc->used = 1;
2083 		mutex_lock(lock);
2084 		list_add(&buf_desc->list, buf_list);
2085 		mutex_unlock(lock);
2086 		break; /* found */
2087 	}
2088 
2089 	if (IS_ERR(buf_desc))
2090 		return PTR_ERR(buf_desc);
2091 
2092 	if (!is_smcd) {
2093 		if (smcr_buf_map_usable_links(lgr, buf_desc, is_rmb)) {
2094 			smcr_buf_unuse(buf_desc, lgr);
2095 			return -ENOMEM;
2096 		}
2097 	}
2098 
2099 	if (is_rmb) {
2100 		conn->rmb_desc = buf_desc;
2101 		conn->rmbe_size_short = bufsize_short;
2102 		smc->sk.sk_rcvbuf = bufsize * 2;
2103 		atomic_set(&conn->bytes_to_rcv, 0);
2104 		conn->rmbe_update_limit =
2105 			smc_rmb_wnd_update_limit(buf_desc->len);
2106 		if (is_smcd)
2107 			smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
2108 	} else {
2109 		conn->sndbuf_desc = buf_desc;
2110 		smc->sk.sk_sndbuf = bufsize * 2;
2111 		atomic_set(&conn->sndbuf_space, bufsize);
2112 	}
2113 	return 0;
2114 }
2115 
2116 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)
2117 {
2118 	if (!conn->lgr || conn->lgr->is_smcd || !smc_link_active(conn->lnk))
2119 		return;
2120 	smc_ib_sync_sg_for_cpu(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);
2121 }
2122 
2123 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
2124 {
2125 	if (!conn->lgr || conn->lgr->is_smcd || !smc_link_active(conn->lnk))
2126 		return;
2127 	smc_ib_sync_sg_for_device(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);
2128 }
2129 
2130 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
2131 {
2132 	int i;
2133 
2134 	if (!conn->lgr || conn->lgr->is_smcd)
2135 		return;
2136 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2137 		if (!smc_link_active(&conn->lgr->lnk[i]))
2138 			continue;
2139 		smc_ib_sync_sg_for_cpu(&conn->lgr->lnk[i], conn->rmb_desc,
2140 				       DMA_FROM_DEVICE);
2141 	}
2142 }
2143 
2144 void smc_rmb_sync_sg_for_device(struct smc_connection *conn)
2145 {
2146 	int i;
2147 
2148 	if (!conn->lgr || conn->lgr->is_smcd)
2149 		return;
2150 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2151 		if (!smc_link_active(&conn->lgr->lnk[i]))
2152 			continue;
2153 		smc_ib_sync_sg_for_device(&conn->lgr->lnk[i], conn->rmb_desc,
2154 					  DMA_FROM_DEVICE);
2155 	}
2156 }
2157 
2158 /* create the send and receive buffer for an SMC socket;
2159  * receive buffers are called RMBs;
2160  * (even though the SMC protocol allows more than one RMB-element per RMB,
2161  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
2162  * extra RMB for every connection in a link group
2163  */
2164 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
2165 {
2166 	int rc;
2167 
2168 	/* create send buffer */
2169 	rc = __smc_buf_create(smc, is_smcd, false);
2170 	if (rc)
2171 		return rc;
2172 	/* create rmb */
2173 	rc = __smc_buf_create(smc, is_smcd, true);
2174 	if (rc) {
2175 		mutex_lock(&smc->conn.lgr->sndbufs_lock);
2176 		list_del(&smc->conn.sndbuf_desc->list);
2177 		mutex_unlock(&smc->conn.lgr->sndbufs_lock);
2178 		smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
2179 		smc->conn.sndbuf_desc = NULL;
2180 	}
2181 	return rc;
2182 }
2183 
2184 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
2185 {
2186 	int i;
2187 
2188 	for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
2189 		if (!test_and_set_bit(i, lgr->rtokens_used_mask))
2190 			return i;
2191 	}
2192 	return -ENOSPC;
2193 }
2194 
2195 static int smc_rtoken_find_by_link(struct smc_link_group *lgr, int lnk_idx,
2196 				   u32 rkey)
2197 {
2198 	int i;
2199 
2200 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2201 		if (test_bit(i, lgr->rtokens_used_mask) &&
2202 		    lgr->rtokens[i][lnk_idx].rkey == rkey)
2203 			return i;
2204 	}
2205 	return -ENOENT;
2206 }
2207 
2208 /* set rtoken for a new link to an existing rmb */
2209 void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
2210 		    __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey)
2211 {
2212 	int rtok_idx;
2213 
2214 	rtok_idx = smc_rtoken_find_by_link(lgr, link_idx, ntohl(nw_rkey_known));
2215 	if (rtok_idx == -ENOENT)
2216 		return;
2217 	lgr->rtokens[rtok_idx][link_idx_new].rkey = ntohl(nw_rkey);
2218 	lgr->rtokens[rtok_idx][link_idx_new].dma_addr = be64_to_cpu(nw_vaddr);
2219 }
2220 
2221 /* set rtoken for a new link whose link_id is given */
2222 void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
2223 		     __be64 nw_vaddr, __be32 nw_rkey)
2224 {
2225 	u64 dma_addr = be64_to_cpu(nw_vaddr);
2226 	u32 rkey = ntohl(nw_rkey);
2227 	bool found = false;
2228 	int link_idx;
2229 
2230 	for (link_idx = 0; link_idx < SMC_LINKS_PER_LGR_MAX; link_idx++) {
2231 		if (lgr->lnk[link_idx].link_id == link_id) {
2232 			found = true;
2233 			break;
2234 		}
2235 	}
2236 	if (!found)
2237 		return;
2238 	lgr->rtokens[rtok_idx][link_idx].rkey = rkey;
2239 	lgr->rtokens[rtok_idx][link_idx].dma_addr = dma_addr;
2240 }
2241 
2242 /* add a new rtoken from peer */
2243 int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey)
2244 {
2245 	struct smc_link_group *lgr = smc_get_lgr(lnk);
2246 	u64 dma_addr = be64_to_cpu(nw_vaddr);
2247 	u32 rkey = ntohl(nw_rkey);
2248 	int i;
2249 
2250 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2251 		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2252 		    lgr->rtokens[i][lnk->link_idx].dma_addr == dma_addr &&
2253 		    test_bit(i, lgr->rtokens_used_mask)) {
2254 			/* already in list */
2255 			return i;
2256 		}
2257 	}
2258 	i = smc_rmb_reserve_rtoken_idx(lgr);
2259 	if (i < 0)
2260 		return i;
2261 	lgr->rtokens[i][lnk->link_idx].rkey = rkey;
2262 	lgr->rtokens[i][lnk->link_idx].dma_addr = dma_addr;
2263 	return i;
2264 }
2265 
2266 /* delete an rtoken from all links */
2267 int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey)
2268 {
2269 	struct smc_link_group *lgr = smc_get_lgr(lnk);
2270 	u32 rkey = ntohl(nw_rkey);
2271 	int i, j;
2272 
2273 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2274 		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2275 		    test_bit(i, lgr->rtokens_used_mask)) {
2276 			for (j = 0; j < SMC_LINKS_PER_LGR_MAX; j++) {
2277 				lgr->rtokens[i][j].rkey = 0;
2278 				lgr->rtokens[i][j].dma_addr = 0;
2279 			}
2280 			clear_bit(i, lgr->rtokens_used_mask);
2281 			return 0;
2282 		}
2283 	}
2284 	return -ENOENT;
2285 }
2286 
2287 /* save rkey and dma_addr received from peer during clc handshake */
2288 int smc_rmb_rtoken_handling(struct smc_connection *conn,
2289 			    struct smc_link *lnk,
2290 			    struct smc_clc_msg_accept_confirm *clc)
2291 {
2292 	conn->rtoken_idx = smc_rtoken_add(lnk, clc->r0.rmb_dma_addr,
2293 					  clc->r0.rmb_rkey);
2294 	if (conn->rtoken_idx < 0)
2295 		return conn->rtoken_idx;
2296 	return 0;
2297 }
2298 
2299 static void smc_core_going_away(void)
2300 {
2301 	struct smc_ib_device *smcibdev;
2302 	struct smcd_dev *smcd;
2303 
2304 	mutex_lock(&smc_ib_devices.mutex);
2305 	list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
2306 		int i;
2307 
2308 		for (i = 0; i < SMC_MAX_PORTS; i++)
2309 			set_bit(i, smcibdev->ports_going_away);
2310 	}
2311 	mutex_unlock(&smc_ib_devices.mutex);
2312 
2313 	mutex_lock(&smcd_dev_list.mutex);
2314 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
2315 		smcd->going_away = 1;
2316 	}
2317 	mutex_unlock(&smcd_dev_list.mutex);
2318 }
2319 
2320 /* Clean up all SMC link groups */
2321 static void smc_lgrs_shutdown(void)
2322 {
2323 	struct smcd_dev *smcd;
2324 
2325 	smc_core_going_away();
2326 
2327 	smc_smcr_terminate_all(NULL);
2328 
2329 	mutex_lock(&smcd_dev_list.mutex);
2330 	list_for_each_entry(smcd, &smcd_dev_list.list, list)
2331 		smc_smcd_terminate_all(smcd);
2332 	mutex_unlock(&smcd_dev_list.mutex);
2333 }
2334 
2335 static int smc_core_reboot_event(struct notifier_block *this,
2336 				 unsigned long event, void *ptr)
2337 {
2338 	smc_lgrs_shutdown();
2339 	smc_ib_unregister_client();
2340 	return 0;
2341 }
2342 
2343 static struct notifier_block smc_reboot_notifier = {
2344 	.notifier_call = smc_core_reboot_event,
2345 };
2346 
2347 int __init smc_core_init(void)
2348 {
2349 	return register_reboot_notifier(&smc_reboot_notifier);
2350 }
2351 
2352 /* Called (from smc_exit) when module is removed */
2353 void smc_core_exit(void)
2354 {
2355 	unregister_reboot_notifier(&smc_reboot_notifier);
2356 	smc_lgrs_shutdown();
2357 }
2358