xref: /linux/net/smc/smc_core.c (revision 1634b7adcc5bef645b3666fdd564e5952a9e24e0)
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 #include "smc_stats.h"
37 #include "smc_tracepoint.h"
38 
39 #define SMC_LGR_NUM_INCR		256
40 #define SMC_LGR_FREE_DELAY_SERV		(600 * HZ)
41 #define SMC_LGR_FREE_DELAY_CLNT		(SMC_LGR_FREE_DELAY_SERV + 10 * HZ)
42 
43 struct smc_lgr_list smc_lgr_list = {	/* established link groups */
44 	.lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
45 	.list = LIST_HEAD_INIT(smc_lgr_list.list),
46 	.num = 0,
47 };
48 
49 static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */
50 static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted);
51 
52 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
53 			 struct smc_buf_desc *buf_desc);
54 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft);
55 
56 static void smc_link_down_work(struct work_struct *work);
57 
58 /* return head of link group list and its lock for a given link group */
59 static inline struct list_head *smc_lgr_list_head(struct smc_link_group *lgr,
60 						  spinlock_t **lgr_lock)
61 {
62 	if (lgr->is_smcd) {
63 		*lgr_lock = &lgr->smcd->lgr_lock;
64 		return &lgr->smcd->lgr_list;
65 	}
66 
67 	*lgr_lock = &smc_lgr_list.lock;
68 	return &smc_lgr_list.list;
69 }
70 
71 static void smc_ibdev_cnt_inc(struct smc_link *lnk)
72 {
73 	atomic_inc(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
74 }
75 
76 static void smc_ibdev_cnt_dec(struct smc_link *lnk)
77 {
78 	atomic_dec(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
79 }
80 
81 static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
82 {
83 	/* client link group creation always follows the server link group
84 	 * creation. For client use a somewhat higher removal delay time,
85 	 * otherwise there is a risk of out-of-sync link groups.
86 	 */
87 	if (!lgr->freeing) {
88 		mod_delayed_work(system_wq, &lgr->free_work,
89 				 (!lgr->is_smcd && lgr->role == SMC_CLNT) ?
90 						SMC_LGR_FREE_DELAY_CLNT :
91 						SMC_LGR_FREE_DELAY_SERV);
92 	}
93 }
94 
95 /* Register connection's alert token in our lookup structure.
96  * To use rbtrees we have to implement our own insert core.
97  * Requires @conns_lock
98  * @smc		connection to register
99  * Returns 0 on success, != otherwise.
100  */
101 static void smc_lgr_add_alert_token(struct smc_connection *conn)
102 {
103 	struct rb_node **link, *parent = NULL;
104 	u32 token = conn->alert_token_local;
105 
106 	link = &conn->lgr->conns_all.rb_node;
107 	while (*link) {
108 		struct smc_connection *cur = rb_entry(*link,
109 					struct smc_connection, alert_node);
110 
111 		parent = *link;
112 		if (cur->alert_token_local > token)
113 			link = &parent->rb_left;
114 		else
115 			link = &parent->rb_right;
116 	}
117 	/* Put the new node there */
118 	rb_link_node(&conn->alert_node, parent, link);
119 	rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
120 }
121 
122 /* assign an SMC-R link to the connection */
123 static int smcr_lgr_conn_assign_link(struct smc_connection *conn, bool first)
124 {
125 	enum smc_link_state expected = first ? SMC_LNK_ACTIVATING :
126 				       SMC_LNK_ACTIVE;
127 	int i, j;
128 
129 	/* do link balancing */
130 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
131 		struct smc_link *lnk = &conn->lgr->lnk[i];
132 
133 		if (lnk->state != expected || lnk->link_is_asym)
134 			continue;
135 		if (conn->lgr->role == SMC_CLNT) {
136 			conn->lnk = lnk; /* temporary, SMC server assigns link*/
137 			break;
138 		}
139 		if (conn->lgr->conns_num % 2) {
140 			for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
141 				struct smc_link *lnk2;
142 
143 				lnk2 = &conn->lgr->lnk[j];
144 				if (lnk2->state == expected &&
145 				    !lnk2->link_is_asym) {
146 					conn->lnk = lnk2;
147 					break;
148 				}
149 			}
150 		}
151 		if (!conn->lnk)
152 			conn->lnk = lnk;
153 		break;
154 	}
155 	if (!conn->lnk)
156 		return SMC_CLC_DECL_NOACTLINK;
157 	atomic_inc(&conn->lnk->conn_cnt);
158 	return 0;
159 }
160 
161 /* Register connection in link group by assigning an alert token
162  * registered in a search tree.
163  * Requires @conns_lock
164  * Note that '0' is a reserved value and not assigned.
165  */
166 static int smc_lgr_register_conn(struct smc_connection *conn, bool first)
167 {
168 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
169 	static atomic_t nexttoken = ATOMIC_INIT(0);
170 	int rc;
171 
172 	if (!conn->lgr->is_smcd) {
173 		rc = smcr_lgr_conn_assign_link(conn, first);
174 		if (rc) {
175 			conn->lgr = NULL;
176 			return rc;
177 		}
178 	}
179 	/* find a new alert_token_local value not yet used by some connection
180 	 * in this link group
181 	 */
182 	sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
183 	while (!conn->alert_token_local) {
184 		conn->alert_token_local = atomic_inc_return(&nexttoken);
185 		if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
186 			conn->alert_token_local = 0;
187 	}
188 	smc_lgr_add_alert_token(conn);
189 	conn->lgr->conns_num++;
190 	return 0;
191 }
192 
193 /* Unregister connection and reset the alert token of the given connection<
194  */
195 static void __smc_lgr_unregister_conn(struct smc_connection *conn)
196 {
197 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
198 	struct smc_link_group *lgr = conn->lgr;
199 
200 	rb_erase(&conn->alert_node, &lgr->conns_all);
201 	if (conn->lnk)
202 		atomic_dec(&conn->lnk->conn_cnt);
203 	lgr->conns_num--;
204 	conn->alert_token_local = 0;
205 	sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
206 }
207 
208 /* Unregister connection from lgr
209  */
210 static void smc_lgr_unregister_conn(struct smc_connection *conn)
211 {
212 	struct smc_link_group *lgr = conn->lgr;
213 
214 	if (!smc_conn_lgr_valid(conn))
215 		return;
216 	write_lock_bh(&lgr->conns_lock);
217 	if (conn->alert_token_local) {
218 		__smc_lgr_unregister_conn(conn);
219 	}
220 	write_unlock_bh(&lgr->conns_lock);
221 }
222 
223 int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb)
224 {
225 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
226 	char hostname[SMC_MAX_HOSTNAME_LEN + 1];
227 	char smc_seid[SMC_MAX_EID_LEN + 1];
228 	struct nlattr *attrs;
229 	u8 *seid = NULL;
230 	u8 *host = NULL;
231 	void *nlh;
232 
233 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
234 			  &smc_gen_nl_family, NLM_F_MULTI,
235 			  SMC_NETLINK_GET_SYS_INFO);
236 	if (!nlh)
237 		goto errmsg;
238 	if (cb_ctx->pos[0])
239 		goto errout;
240 	attrs = nla_nest_start(skb, SMC_GEN_SYS_INFO);
241 	if (!attrs)
242 		goto errout;
243 	if (nla_put_u8(skb, SMC_NLA_SYS_VER, SMC_V2))
244 		goto errattr;
245 	if (nla_put_u8(skb, SMC_NLA_SYS_REL, SMC_RELEASE))
246 		goto errattr;
247 	if (nla_put_u8(skb, SMC_NLA_SYS_IS_ISM_V2, smc_ism_is_v2_capable()))
248 		goto errattr;
249 	if (nla_put_u8(skb, SMC_NLA_SYS_IS_SMCR_V2, true))
250 		goto errattr;
251 	smc_clc_get_hostname(&host);
252 	if (host) {
253 		memcpy(hostname, host, SMC_MAX_HOSTNAME_LEN);
254 		hostname[SMC_MAX_HOSTNAME_LEN] = 0;
255 		if (nla_put_string(skb, SMC_NLA_SYS_LOCAL_HOST, hostname))
256 			goto errattr;
257 	}
258 	if (smc_ism_is_v2_capable()) {
259 		smc_ism_get_system_eid(&seid);
260 		memcpy(smc_seid, seid, SMC_MAX_EID_LEN);
261 		smc_seid[SMC_MAX_EID_LEN] = 0;
262 		if (nla_put_string(skb, SMC_NLA_SYS_SEID, smc_seid))
263 			goto errattr;
264 	}
265 	nla_nest_end(skb, attrs);
266 	genlmsg_end(skb, nlh);
267 	cb_ctx->pos[0] = 1;
268 	return skb->len;
269 
270 errattr:
271 	nla_nest_cancel(skb, attrs);
272 errout:
273 	genlmsg_cancel(skb, nlh);
274 errmsg:
275 	return skb->len;
276 }
277 
278 /* Fill SMC_NLA_LGR_D_V2_COMMON/SMC_NLA_LGR_R_V2_COMMON nested attributes */
279 static int smc_nl_fill_lgr_v2_common(struct smc_link_group *lgr,
280 				     struct sk_buff *skb,
281 				     struct netlink_callback *cb,
282 				     struct nlattr *v2_attrs)
283 {
284 	char smc_host[SMC_MAX_HOSTNAME_LEN + 1];
285 	char smc_eid[SMC_MAX_EID_LEN + 1];
286 
287 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_VER, lgr->smc_version))
288 		goto errv2attr;
289 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_REL, lgr->peer_smc_release))
290 		goto errv2attr;
291 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_OS, lgr->peer_os))
292 		goto errv2attr;
293 	memcpy(smc_host, lgr->peer_hostname, SMC_MAX_HOSTNAME_LEN);
294 	smc_host[SMC_MAX_HOSTNAME_LEN] = 0;
295 	if (nla_put_string(skb, SMC_NLA_LGR_V2_PEER_HOST, smc_host))
296 		goto errv2attr;
297 	memcpy(smc_eid, lgr->negotiated_eid, SMC_MAX_EID_LEN);
298 	smc_eid[SMC_MAX_EID_LEN] = 0;
299 	if (nla_put_string(skb, SMC_NLA_LGR_V2_NEG_EID, smc_eid))
300 		goto errv2attr;
301 
302 	nla_nest_end(skb, v2_attrs);
303 	return 0;
304 
305 errv2attr:
306 	nla_nest_cancel(skb, v2_attrs);
307 	return -EMSGSIZE;
308 }
309 
310 static int smc_nl_fill_smcr_lgr_v2(struct smc_link_group *lgr,
311 				   struct sk_buff *skb,
312 				   struct netlink_callback *cb)
313 {
314 	struct nlattr *v2_attrs;
315 
316 	v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2);
317 	if (!v2_attrs)
318 		goto errattr;
319 	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_DIRECT, !lgr->uses_gateway))
320 		goto errv2attr;
321 
322 	nla_nest_end(skb, v2_attrs);
323 	return 0;
324 
325 errv2attr:
326 	nla_nest_cancel(skb, v2_attrs);
327 errattr:
328 	return -EMSGSIZE;
329 }
330 
331 static int smc_nl_fill_lgr(struct smc_link_group *lgr,
332 			   struct sk_buff *skb,
333 			   struct netlink_callback *cb)
334 {
335 	char smc_target[SMC_MAX_PNETID_LEN + 1];
336 	struct nlattr *attrs, *v2_attrs;
337 
338 	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCR);
339 	if (!attrs)
340 		goto errout;
341 
342 	if (nla_put_u32(skb, SMC_NLA_LGR_R_ID, *((u32 *)&lgr->id)))
343 		goto errattr;
344 	if (nla_put_u32(skb, SMC_NLA_LGR_R_CONNS_NUM, lgr->conns_num))
345 		goto errattr;
346 	if (nla_put_u8(skb, SMC_NLA_LGR_R_ROLE, lgr->role))
347 		goto errattr;
348 	if (nla_put_u8(skb, SMC_NLA_LGR_R_TYPE, lgr->type))
349 		goto errattr;
350 	if (nla_put_u8(skb, SMC_NLA_LGR_R_BUF_TYPE, lgr->buf_type))
351 		goto errattr;
352 	if (nla_put_u8(skb, SMC_NLA_LGR_R_VLAN_ID, lgr->vlan_id))
353 		goto errattr;
354 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_R_NET_COOKIE,
355 			      lgr->net->net_cookie, SMC_NLA_LGR_R_PAD))
356 		goto errattr;
357 	memcpy(smc_target, lgr->pnet_id, SMC_MAX_PNETID_LEN);
358 	smc_target[SMC_MAX_PNETID_LEN] = 0;
359 	if (nla_put_string(skb, SMC_NLA_LGR_R_PNETID, smc_target))
360 		goto errattr;
361 	if (lgr->smc_version > SMC_V1) {
362 		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2_COMMON);
363 		if (!v2_attrs)
364 			goto errattr;
365 		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
366 			goto errattr;
367 		if (smc_nl_fill_smcr_lgr_v2(lgr, skb, cb))
368 			goto errattr;
369 	}
370 
371 	nla_nest_end(skb, attrs);
372 	return 0;
373 errattr:
374 	nla_nest_cancel(skb, attrs);
375 errout:
376 	return -EMSGSIZE;
377 }
378 
379 static int smc_nl_fill_lgr_link(struct smc_link_group *lgr,
380 				struct smc_link *link,
381 				struct sk_buff *skb,
382 				struct netlink_callback *cb)
383 {
384 	char smc_ibname[IB_DEVICE_NAME_MAX];
385 	u8 smc_gid_target[41];
386 	struct nlattr *attrs;
387 	u32 link_uid = 0;
388 	void *nlh;
389 
390 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
391 			  &smc_gen_nl_family, NLM_F_MULTI,
392 			  SMC_NETLINK_GET_LINK_SMCR);
393 	if (!nlh)
394 		goto errmsg;
395 
396 	attrs = nla_nest_start(skb, SMC_GEN_LINK_SMCR);
397 	if (!attrs)
398 		goto errout;
399 
400 	if (nla_put_u8(skb, SMC_NLA_LINK_ID, link->link_id))
401 		goto errattr;
402 	if (nla_put_u32(skb, SMC_NLA_LINK_STATE, link->state))
403 		goto errattr;
404 	if (nla_put_u32(skb, SMC_NLA_LINK_CONN_CNT,
405 			atomic_read(&link->conn_cnt)))
406 		goto errattr;
407 	if (nla_put_u8(skb, SMC_NLA_LINK_IB_PORT, link->ibport))
408 		goto errattr;
409 	if (nla_put_u32(skb, SMC_NLA_LINK_NET_DEV, link->ndev_ifidx))
410 		goto errattr;
411 	snprintf(smc_ibname, sizeof(smc_ibname), "%s", link->ibname);
412 	if (nla_put_string(skb, SMC_NLA_LINK_IB_DEV, smc_ibname))
413 		goto errattr;
414 	memcpy(&link_uid, link->link_uid, sizeof(link_uid));
415 	if (nla_put_u32(skb, SMC_NLA_LINK_UID, link_uid))
416 		goto errattr;
417 	memcpy(&link_uid, link->peer_link_uid, sizeof(link_uid));
418 	if (nla_put_u32(skb, SMC_NLA_LINK_PEER_UID, link_uid))
419 		goto errattr;
420 	memset(smc_gid_target, 0, sizeof(smc_gid_target));
421 	smc_gid_be16_convert(smc_gid_target, link->gid);
422 	if (nla_put_string(skb, SMC_NLA_LINK_GID, smc_gid_target))
423 		goto errattr;
424 	memset(smc_gid_target, 0, sizeof(smc_gid_target));
425 	smc_gid_be16_convert(smc_gid_target, link->peer_gid);
426 	if (nla_put_string(skb, SMC_NLA_LINK_PEER_GID, smc_gid_target))
427 		goto errattr;
428 
429 	nla_nest_end(skb, attrs);
430 	genlmsg_end(skb, nlh);
431 	return 0;
432 errattr:
433 	nla_nest_cancel(skb, attrs);
434 errout:
435 	genlmsg_cancel(skb, nlh);
436 errmsg:
437 	return -EMSGSIZE;
438 }
439 
440 static int smc_nl_handle_lgr(struct smc_link_group *lgr,
441 			     struct sk_buff *skb,
442 			     struct netlink_callback *cb,
443 			     bool list_links)
444 {
445 	void *nlh;
446 	int i;
447 
448 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
449 			  &smc_gen_nl_family, NLM_F_MULTI,
450 			  SMC_NETLINK_GET_LGR_SMCR);
451 	if (!nlh)
452 		goto errmsg;
453 	if (smc_nl_fill_lgr(lgr, skb, cb))
454 		goto errout;
455 
456 	genlmsg_end(skb, nlh);
457 	if (!list_links)
458 		goto out;
459 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
460 		if (!smc_link_usable(&lgr->lnk[i]))
461 			continue;
462 		if (smc_nl_fill_lgr_link(lgr, &lgr->lnk[i], skb, cb))
463 			goto errout;
464 	}
465 out:
466 	return 0;
467 
468 errout:
469 	genlmsg_cancel(skb, nlh);
470 errmsg:
471 	return -EMSGSIZE;
472 }
473 
474 static void smc_nl_fill_lgr_list(struct smc_lgr_list *smc_lgr,
475 				 struct sk_buff *skb,
476 				 struct netlink_callback *cb,
477 				 bool list_links)
478 {
479 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
480 	struct smc_link_group *lgr;
481 	int snum = cb_ctx->pos[0];
482 	int num = 0;
483 
484 	spin_lock_bh(&smc_lgr->lock);
485 	list_for_each_entry(lgr, &smc_lgr->list, list) {
486 		if (num < snum)
487 			goto next;
488 		if (smc_nl_handle_lgr(lgr, skb, cb, list_links))
489 			goto errout;
490 next:
491 		num++;
492 	}
493 errout:
494 	spin_unlock_bh(&smc_lgr->lock);
495 	cb_ctx->pos[0] = num;
496 }
497 
498 static int smc_nl_fill_smcd_lgr(struct smc_link_group *lgr,
499 				struct sk_buff *skb,
500 				struct netlink_callback *cb)
501 {
502 	char smc_pnet[SMC_MAX_PNETID_LEN + 1];
503 	struct smcd_dev *smcd = lgr->smcd;
504 	struct nlattr *attrs;
505 	void *nlh;
506 
507 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
508 			  &smc_gen_nl_family, NLM_F_MULTI,
509 			  SMC_NETLINK_GET_LGR_SMCD);
510 	if (!nlh)
511 		goto errmsg;
512 
513 	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCD);
514 	if (!attrs)
515 		goto errout;
516 
517 	if (nla_put_u32(skb, SMC_NLA_LGR_D_ID, *((u32 *)&lgr->id)))
518 		goto errattr;
519 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_GID,
520 			      smcd->ops->get_local_gid(smcd),
521 				  SMC_NLA_LGR_D_PAD))
522 		goto errattr;
523 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_PEER_GID, lgr->peer_gid,
524 			      SMC_NLA_LGR_D_PAD))
525 		goto errattr;
526 	if (nla_put_u8(skb, SMC_NLA_LGR_D_VLAN_ID, lgr->vlan_id))
527 		goto errattr;
528 	if (nla_put_u32(skb, SMC_NLA_LGR_D_CONNS_NUM, lgr->conns_num))
529 		goto errattr;
530 	if (nla_put_u32(skb, SMC_NLA_LGR_D_CHID, smc_ism_get_chid(lgr->smcd)))
531 		goto errattr;
532 	memcpy(smc_pnet, lgr->smcd->pnetid, SMC_MAX_PNETID_LEN);
533 	smc_pnet[SMC_MAX_PNETID_LEN] = 0;
534 	if (nla_put_string(skb, SMC_NLA_LGR_D_PNETID, smc_pnet))
535 		goto errattr;
536 	if (lgr->smc_version > SMC_V1) {
537 		struct nlattr *v2_attrs;
538 
539 		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_D_V2_COMMON);
540 		if (!v2_attrs)
541 			goto errattr;
542 		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
543 			goto errattr;
544 	}
545 	nla_nest_end(skb, attrs);
546 	genlmsg_end(skb, nlh);
547 	return 0;
548 
549 errattr:
550 	nla_nest_cancel(skb, attrs);
551 errout:
552 	genlmsg_cancel(skb, nlh);
553 errmsg:
554 	return -EMSGSIZE;
555 }
556 
557 static int smc_nl_handle_smcd_lgr(struct smcd_dev *dev,
558 				  struct sk_buff *skb,
559 				  struct netlink_callback *cb)
560 {
561 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
562 	struct smc_link_group *lgr;
563 	int snum = cb_ctx->pos[1];
564 	int rc = 0, num = 0;
565 
566 	spin_lock_bh(&dev->lgr_lock);
567 	list_for_each_entry(lgr, &dev->lgr_list, list) {
568 		if (!lgr->is_smcd)
569 			continue;
570 		if (num < snum)
571 			goto next;
572 		rc = smc_nl_fill_smcd_lgr(lgr, skb, cb);
573 		if (rc)
574 			goto errout;
575 next:
576 		num++;
577 	}
578 errout:
579 	spin_unlock_bh(&dev->lgr_lock);
580 	cb_ctx->pos[1] = num;
581 	return rc;
582 }
583 
584 static int smc_nl_fill_smcd_dev(struct smcd_dev_list *dev_list,
585 				struct sk_buff *skb,
586 				struct netlink_callback *cb)
587 {
588 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
589 	struct smcd_dev *smcd_dev;
590 	int snum = cb_ctx->pos[0];
591 	int rc = 0, num = 0;
592 
593 	mutex_lock(&dev_list->mutex);
594 	list_for_each_entry(smcd_dev, &dev_list->list, list) {
595 		if (list_empty(&smcd_dev->lgr_list))
596 			continue;
597 		if (num < snum)
598 			goto next;
599 		rc = smc_nl_handle_smcd_lgr(smcd_dev, skb, cb);
600 		if (rc)
601 			goto errout;
602 next:
603 		num++;
604 	}
605 errout:
606 	mutex_unlock(&dev_list->mutex);
607 	cb_ctx->pos[0] = num;
608 	return rc;
609 }
610 
611 int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
612 {
613 	bool list_links = false;
614 
615 	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
616 	return skb->len;
617 }
618 
619 int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb)
620 {
621 	bool list_links = true;
622 
623 	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
624 	return skb->len;
625 }
626 
627 int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
628 {
629 	smc_nl_fill_smcd_dev(&smcd_dev_list, skb, cb);
630 	return skb->len;
631 }
632 
633 void smc_lgr_cleanup_early(struct smc_link_group *lgr)
634 {
635 	spinlock_t *lgr_lock;
636 
637 	if (!lgr)
638 		return;
639 
640 	smc_lgr_list_head(lgr, &lgr_lock);
641 	spin_lock_bh(lgr_lock);
642 	/* do not use this link group for new connections */
643 	if (!list_empty(&lgr->list))
644 		list_del_init(&lgr->list);
645 	spin_unlock_bh(lgr_lock);
646 	__smc_lgr_terminate(lgr, true);
647 }
648 
649 static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
650 {
651 	int i;
652 
653 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
654 		struct smc_link *lnk = &lgr->lnk[i];
655 
656 		if (smc_link_sendable(lnk))
657 			lnk->state = SMC_LNK_INACTIVE;
658 	}
659 	wake_up_all(&lgr->llc_msg_waiter);
660 	wake_up_all(&lgr->llc_flow_waiter);
661 }
662 
663 static void smc_lgr_free(struct smc_link_group *lgr);
664 
665 static void smc_lgr_free_work(struct work_struct *work)
666 {
667 	struct smc_link_group *lgr = container_of(to_delayed_work(work),
668 						  struct smc_link_group,
669 						  free_work);
670 	spinlock_t *lgr_lock;
671 	bool conns;
672 
673 	smc_lgr_list_head(lgr, &lgr_lock);
674 	spin_lock_bh(lgr_lock);
675 	if (lgr->freeing) {
676 		spin_unlock_bh(lgr_lock);
677 		return;
678 	}
679 	read_lock_bh(&lgr->conns_lock);
680 	conns = RB_EMPTY_ROOT(&lgr->conns_all);
681 	read_unlock_bh(&lgr->conns_lock);
682 	if (!conns) { /* number of lgr connections is no longer zero */
683 		spin_unlock_bh(lgr_lock);
684 		return;
685 	}
686 	list_del_init(&lgr->list); /* remove from smc_lgr_list */
687 	lgr->freeing = 1; /* this instance does the freeing, no new schedule */
688 	spin_unlock_bh(lgr_lock);
689 	cancel_delayed_work(&lgr->free_work);
690 
691 	if (!lgr->is_smcd && !lgr->terminating)
692 		smc_llc_send_link_delete_all(lgr, true,
693 					     SMC_LLC_DEL_PROG_INIT_TERM);
694 	if (lgr->is_smcd && !lgr->terminating)
695 		smc_ism_signal_shutdown(lgr);
696 	if (!lgr->is_smcd)
697 		smcr_lgr_link_deactivate_all(lgr);
698 	smc_lgr_free(lgr);
699 }
700 
701 static void smc_lgr_terminate_work(struct work_struct *work)
702 {
703 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
704 						  terminate_work);
705 
706 	__smc_lgr_terminate(lgr, true);
707 }
708 
709 /* return next unique link id for the lgr */
710 static u8 smcr_next_link_id(struct smc_link_group *lgr)
711 {
712 	u8 link_id;
713 	int i;
714 
715 	while (1) {
716 again:
717 		link_id = ++lgr->next_link_id;
718 		if (!link_id)	/* skip zero as link_id */
719 			link_id = ++lgr->next_link_id;
720 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
721 			if (smc_link_usable(&lgr->lnk[i]) &&
722 			    lgr->lnk[i].link_id == link_id)
723 				goto again;
724 		}
725 		break;
726 	}
727 	return link_id;
728 }
729 
730 static void smcr_copy_dev_info_to_link(struct smc_link *link)
731 {
732 	struct smc_ib_device *smcibdev = link->smcibdev;
733 
734 	snprintf(link->ibname, sizeof(link->ibname), "%s",
735 		 smcibdev->ibdev->name);
736 	link->ndev_ifidx = smcibdev->ndev_ifidx[link->ibport - 1];
737 }
738 
739 int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
740 		   u8 link_idx, struct smc_init_info *ini)
741 {
742 	struct smc_ib_device *smcibdev;
743 	u8 rndvec[3];
744 	int rc;
745 
746 	if (lgr->smc_version == SMC_V2) {
747 		lnk->smcibdev = ini->smcrv2.ib_dev_v2;
748 		lnk->ibport = ini->smcrv2.ib_port_v2;
749 	} else {
750 		lnk->smcibdev = ini->ib_dev;
751 		lnk->ibport = ini->ib_port;
752 	}
753 	get_device(&lnk->smcibdev->ibdev->dev);
754 	atomic_inc(&lnk->smcibdev->lnk_cnt);
755 	refcount_set(&lnk->refcnt, 1); /* link refcnt is set to 1 */
756 	lnk->clearing = 0;
757 	lnk->path_mtu = lnk->smcibdev->pattr[lnk->ibport - 1].active_mtu;
758 	lnk->link_id = smcr_next_link_id(lgr);
759 	lnk->lgr = lgr;
760 	smc_lgr_hold(lgr); /* lgr_put in smcr_link_clear() */
761 	lnk->link_idx = link_idx;
762 	lnk->wr_rx_id_compl = 0;
763 	smc_ibdev_cnt_inc(lnk);
764 	smcr_copy_dev_info_to_link(lnk);
765 	atomic_set(&lnk->conn_cnt, 0);
766 	smc_llc_link_set_uid(lnk);
767 	INIT_WORK(&lnk->link_down_wrk, smc_link_down_work);
768 	if (!lnk->smcibdev->initialized) {
769 		rc = (int)smc_ib_setup_per_ibdev(lnk->smcibdev);
770 		if (rc)
771 			goto out;
772 	}
773 	get_random_bytes(rndvec, sizeof(rndvec));
774 	lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
775 		(rndvec[2] << 16);
776 	rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
777 				  ini->vlan_id, lnk->gid, &lnk->sgid_index,
778 				  lgr->smc_version == SMC_V2 ?
779 						  &ini->smcrv2 : NULL);
780 	if (rc)
781 		goto out;
782 	rc = smc_llc_link_init(lnk);
783 	if (rc)
784 		goto out;
785 	rc = smc_wr_alloc_link_mem(lnk);
786 	if (rc)
787 		goto clear_llc_lnk;
788 	rc = smc_ib_create_protection_domain(lnk);
789 	if (rc)
790 		goto free_link_mem;
791 	rc = smc_ib_create_queue_pair(lnk);
792 	if (rc)
793 		goto dealloc_pd;
794 	rc = smc_wr_create_link(lnk);
795 	if (rc)
796 		goto destroy_qp;
797 	lnk->state = SMC_LNK_ACTIVATING;
798 	return 0;
799 
800 destroy_qp:
801 	smc_ib_destroy_queue_pair(lnk);
802 dealloc_pd:
803 	smc_ib_dealloc_protection_domain(lnk);
804 free_link_mem:
805 	smc_wr_free_link_mem(lnk);
806 clear_llc_lnk:
807 	smc_llc_link_clear(lnk, false);
808 out:
809 	smc_ibdev_cnt_dec(lnk);
810 	put_device(&lnk->smcibdev->ibdev->dev);
811 	smcibdev = lnk->smcibdev;
812 	memset(lnk, 0, sizeof(struct smc_link));
813 	lnk->state = SMC_LNK_UNUSED;
814 	if (!atomic_dec_return(&smcibdev->lnk_cnt))
815 		wake_up(&smcibdev->lnks_deleted);
816 	smc_lgr_put(lgr); /* lgr_hold above */
817 	return rc;
818 }
819 
820 /* create a new SMC link group */
821 static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
822 {
823 	struct smc_link_group *lgr;
824 	struct list_head *lgr_list;
825 	struct smcd_dev *smcd;
826 	struct smc_link *lnk;
827 	spinlock_t *lgr_lock;
828 	u8 link_idx;
829 	int rc = 0;
830 	int i;
831 
832 	if (ini->is_smcd && ini->vlan_id) {
833 		if (smc_ism_get_vlan(ini->ism_dev[ini->ism_selected],
834 				     ini->vlan_id)) {
835 			rc = SMC_CLC_DECL_ISMVLANERR;
836 			goto out;
837 		}
838 	}
839 
840 	lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
841 	if (!lgr) {
842 		rc = SMC_CLC_DECL_MEM;
843 		goto ism_put_vlan;
844 	}
845 	lgr->tx_wq = alloc_workqueue("smc_tx_wq-%*phN", 0, 0,
846 				     SMC_LGR_ID_SIZE, &lgr->id);
847 	if (!lgr->tx_wq) {
848 		rc = -ENOMEM;
849 		goto free_lgr;
850 	}
851 	lgr->is_smcd = ini->is_smcd;
852 	lgr->sync_err = 0;
853 	lgr->terminating = 0;
854 	lgr->freeing = 0;
855 	lgr->vlan_id = ini->vlan_id;
856 	refcount_set(&lgr->refcnt, 1); /* set lgr refcnt to 1 */
857 	init_rwsem(&lgr->sndbufs_lock);
858 	init_rwsem(&lgr->rmbs_lock);
859 	rwlock_init(&lgr->conns_lock);
860 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
861 		INIT_LIST_HEAD(&lgr->sndbufs[i]);
862 		INIT_LIST_HEAD(&lgr->rmbs[i]);
863 	}
864 	lgr->next_link_id = 0;
865 	smc_lgr_list.num += SMC_LGR_NUM_INCR;
866 	memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
867 	INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
868 	INIT_WORK(&lgr->terminate_work, smc_lgr_terminate_work);
869 	lgr->conns_all = RB_ROOT;
870 	if (ini->is_smcd) {
871 		/* SMC-D specific settings */
872 		smcd = ini->ism_dev[ini->ism_selected];
873 		get_device(smcd->ops->get_dev(smcd));
874 		lgr->peer_gid = ini->ism_peer_gid[ini->ism_selected];
875 		lgr->smcd = ini->ism_dev[ini->ism_selected];
876 		lgr_list = &ini->ism_dev[ini->ism_selected]->lgr_list;
877 		lgr_lock = &lgr->smcd->lgr_lock;
878 		lgr->smc_version = ini->smcd_version;
879 		lgr->peer_shutdown = 0;
880 		atomic_inc(&ini->ism_dev[ini->ism_selected]->lgr_cnt);
881 	} else {
882 		/* SMC-R specific settings */
883 		struct smc_ib_device *ibdev;
884 		int ibport;
885 
886 		lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
887 		lgr->smc_version = ini->smcr_version;
888 		memcpy(lgr->peer_systemid, ini->peer_systemid,
889 		       SMC_SYSTEMID_LEN);
890 		if (lgr->smc_version == SMC_V2) {
891 			ibdev = ini->smcrv2.ib_dev_v2;
892 			ibport = ini->smcrv2.ib_port_v2;
893 			lgr->saddr = ini->smcrv2.saddr;
894 			lgr->uses_gateway = ini->smcrv2.uses_gateway;
895 			memcpy(lgr->nexthop_mac, ini->smcrv2.nexthop_mac,
896 			       ETH_ALEN);
897 		} else {
898 			ibdev = ini->ib_dev;
899 			ibport = ini->ib_port;
900 		}
901 		memcpy(lgr->pnet_id, ibdev->pnetid[ibport - 1],
902 		       SMC_MAX_PNETID_LEN);
903 		rc = smc_wr_alloc_lgr_mem(lgr);
904 		if (rc)
905 			goto free_wq;
906 		smc_llc_lgr_init(lgr, smc);
907 
908 		link_idx = SMC_SINGLE_LINK;
909 		lnk = &lgr->lnk[link_idx];
910 		rc = smcr_link_init(lgr, lnk, link_idx, ini);
911 		if (rc) {
912 			smc_wr_free_lgr_mem(lgr);
913 			goto free_wq;
914 		}
915 		lgr->net = smc_ib_net(lnk->smcibdev);
916 		lgr_list = &smc_lgr_list.list;
917 		lgr_lock = &smc_lgr_list.lock;
918 		lgr->buf_type = lgr->net->smc.sysctl_smcr_buf_type;
919 		atomic_inc(&lgr_cnt);
920 	}
921 	smc->conn.lgr = lgr;
922 	spin_lock_bh(lgr_lock);
923 	list_add_tail(&lgr->list, lgr_list);
924 	spin_unlock_bh(lgr_lock);
925 	return 0;
926 
927 free_wq:
928 	destroy_workqueue(lgr->tx_wq);
929 free_lgr:
930 	kfree(lgr);
931 ism_put_vlan:
932 	if (ini->is_smcd && ini->vlan_id)
933 		smc_ism_put_vlan(ini->ism_dev[ini->ism_selected], ini->vlan_id);
934 out:
935 	if (rc < 0) {
936 		if (rc == -ENOMEM)
937 			rc = SMC_CLC_DECL_MEM;
938 		else
939 			rc = SMC_CLC_DECL_INTERR;
940 	}
941 	return rc;
942 }
943 
944 static int smc_write_space(struct smc_connection *conn)
945 {
946 	int buffer_len = conn->peer_rmbe_size;
947 	union smc_host_cursor prod;
948 	union smc_host_cursor cons;
949 	int space;
950 
951 	smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
952 	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
953 	/* determine rx_buf space */
954 	space = buffer_len - smc_curs_diff(buffer_len, &cons, &prod);
955 	return space;
956 }
957 
958 static int smc_switch_cursor(struct smc_sock *smc, struct smc_cdc_tx_pend *pend,
959 			     struct smc_wr_buf *wr_buf)
960 {
961 	struct smc_connection *conn = &smc->conn;
962 	union smc_host_cursor cons, fin;
963 	int rc = 0;
964 	int diff;
965 
966 	smc_curs_copy(&conn->tx_curs_sent, &conn->tx_curs_fin, conn);
967 	smc_curs_copy(&fin, &conn->local_tx_ctrl_fin, conn);
968 	/* set prod cursor to old state, enforce tx_rdma_writes() */
969 	smc_curs_copy(&conn->local_tx_ctrl.prod, &fin, conn);
970 	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
971 
972 	if (smc_curs_comp(conn->peer_rmbe_size, &cons, &fin) < 0) {
973 		/* cons cursor advanced more than fin, and prod was set
974 		 * fin above, so now prod is smaller than cons. Fix that.
975 		 */
976 		diff = smc_curs_diff(conn->peer_rmbe_size, &fin, &cons);
977 		smc_curs_add(conn->sndbuf_desc->len,
978 			     &conn->tx_curs_sent, diff);
979 		smc_curs_add(conn->sndbuf_desc->len,
980 			     &conn->tx_curs_fin, diff);
981 
982 		smp_mb__before_atomic();
983 		atomic_add(diff, &conn->sndbuf_space);
984 		smp_mb__after_atomic();
985 
986 		smc_curs_add(conn->peer_rmbe_size,
987 			     &conn->local_tx_ctrl.prod, diff);
988 		smc_curs_add(conn->peer_rmbe_size,
989 			     &conn->local_tx_ctrl_fin, diff);
990 	}
991 	/* recalculate, value is used by tx_rdma_writes() */
992 	atomic_set(&smc->conn.peer_rmbe_space, smc_write_space(conn));
993 
994 	if (smc->sk.sk_state != SMC_INIT &&
995 	    smc->sk.sk_state != SMC_CLOSED) {
996 		rc = smcr_cdc_msg_send_validation(conn, pend, wr_buf);
997 		if (!rc) {
998 			queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 0);
999 			smc->sk.sk_data_ready(&smc->sk);
1000 		}
1001 	} else {
1002 		smc_wr_tx_put_slot(conn->lnk,
1003 				   (struct smc_wr_tx_pend_priv *)pend);
1004 	}
1005 	return rc;
1006 }
1007 
1008 void smc_switch_link_and_count(struct smc_connection *conn,
1009 			       struct smc_link *to_lnk)
1010 {
1011 	atomic_dec(&conn->lnk->conn_cnt);
1012 	/* link_hold in smc_conn_create() */
1013 	smcr_link_put(conn->lnk);
1014 	conn->lnk = to_lnk;
1015 	atomic_inc(&conn->lnk->conn_cnt);
1016 	/* link_put in smc_conn_free() */
1017 	smcr_link_hold(conn->lnk);
1018 }
1019 
1020 struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
1021 				  struct smc_link *from_lnk, bool is_dev_err)
1022 {
1023 	struct smc_link *to_lnk = NULL;
1024 	struct smc_cdc_tx_pend *pend;
1025 	struct smc_connection *conn;
1026 	struct smc_wr_buf *wr_buf;
1027 	struct smc_sock *smc;
1028 	struct rb_node *node;
1029 	int i, rc = 0;
1030 
1031 	/* link is inactive, wake up tx waiters */
1032 	smc_wr_wakeup_tx_wait(from_lnk);
1033 
1034 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1035 		if (!smc_link_active(&lgr->lnk[i]) || i == from_lnk->link_idx)
1036 			continue;
1037 		if (is_dev_err && from_lnk->smcibdev == lgr->lnk[i].smcibdev &&
1038 		    from_lnk->ibport == lgr->lnk[i].ibport) {
1039 			continue;
1040 		}
1041 		to_lnk = &lgr->lnk[i];
1042 		break;
1043 	}
1044 	if (!to_lnk || !smc_wr_tx_link_hold(to_lnk)) {
1045 		smc_lgr_terminate_sched(lgr);
1046 		return NULL;
1047 	}
1048 again:
1049 	read_lock_bh(&lgr->conns_lock);
1050 	for (node = rb_first(&lgr->conns_all); node; node = rb_next(node)) {
1051 		conn = rb_entry(node, struct smc_connection, alert_node);
1052 		if (conn->lnk != from_lnk)
1053 			continue;
1054 		smc = container_of(conn, struct smc_sock, conn);
1055 		/* conn->lnk not yet set in SMC_INIT state */
1056 		if (smc->sk.sk_state == SMC_INIT)
1057 			continue;
1058 		if (smc->sk.sk_state == SMC_CLOSED ||
1059 		    smc->sk.sk_state == SMC_PEERCLOSEWAIT1 ||
1060 		    smc->sk.sk_state == SMC_PEERCLOSEWAIT2 ||
1061 		    smc->sk.sk_state == SMC_APPFINCLOSEWAIT ||
1062 		    smc->sk.sk_state == SMC_APPCLOSEWAIT1 ||
1063 		    smc->sk.sk_state == SMC_APPCLOSEWAIT2 ||
1064 		    smc->sk.sk_state == SMC_PEERFINCLOSEWAIT ||
1065 		    smc->sk.sk_state == SMC_PEERABORTWAIT ||
1066 		    smc->sk.sk_state == SMC_PROCESSABORT) {
1067 			spin_lock_bh(&conn->send_lock);
1068 			smc_switch_link_and_count(conn, to_lnk);
1069 			spin_unlock_bh(&conn->send_lock);
1070 			continue;
1071 		}
1072 		sock_hold(&smc->sk);
1073 		read_unlock_bh(&lgr->conns_lock);
1074 		/* pre-fetch buffer outside of send_lock, might sleep */
1075 		rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend);
1076 		if (rc)
1077 			goto err_out;
1078 		/* avoid race with smcr_tx_sndbuf_nonempty() */
1079 		spin_lock_bh(&conn->send_lock);
1080 		smc_switch_link_and_count(conn, to_lnk);
1081 		rc = smc_switch_cursor(smc, pend, wr_buf);
1082 		spin_unlock_bh(&conn->send_lock);
1083 		sock_put(&smc->sk);
1084 		if (rc)
1085 			goto err_out;
1086 		goto again;
1087 	}
1088 	read_unlock_bh(&lgr->conns_lock);
1089 	smc_wr_tx_link_put(to_lnk);
1090 	return to_lnk;
1091 
1092 err_out:
1093 	smcr_link_down_cond_sched(to_lnk);
1094 	smc_wr_tx_link_put(to_lnk);
1095 	return NULL;
1096 }
1097 
1098 static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb,
1099 			   struct smc_link_group *lgr)
1100 {
1101 	struct rw_semaphore *lock;	/* lock buffer list */
1102 	int rc;
1103 
1104 	if (is_rmb && buf_desc->is_conf_rkey && !list_empty(&lgr->list)) {
1105 		/* unregister rmb with peer */
1106 		rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
1107 		if (!rc) {
1108 			/* protect against smc_llc_cli_rkey_exchange() */
1109 			down_read(&lgr->llc_conf_mutex);
1110 			smc_llc_do_delete_rkey(lgr, buf_desc);
1111 			buf_desc->is_conf_rkey = false;
1112 			up_read(&lgr->llc_conf_mutex);
1113 			smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1114 		}
1115 	}
1116 
1117 	if (buf_desc->is_reg_err) {
1118 		/* buf registration failed, reuse not possible */
1119 		lock = is_rmb ? &lgr->rmbs_lock :
1120 				&lgr->sndbufs_lock;
1121 		down_write(lock);
1122 		list_del(&buf_desc->list);
1123 		up_write(lock);
1124 
1125 		smc_buf_free(lgr, is_rmb, buf_desc);
1126 	} else {
1127 		/* memzero_explicit provides potential memory barrier semantics */
1128 		memzero_explicit(buf_desc->cpu_addr, buf_desc->len);
1129 		WRITE_ONCE(buf_desc->used, 0);
1130 	}
1131 }
1132 
1133 static void smc_buf_unuse(struct smc_connection *conn,
1134 			  struct smc_link_group *lgr)
1135 {
1136 	if (conn->sndbuf_desc) {
1137 		if (!lgr->is_smcd && conn->sndbuf_desc->is_vm) {
1138 			smcr_buf_unuse(conn->sndbuf_desc, false, lgr);
1139 		} else {
1140 			memzero_explicit(conn->sndbuf_desc->cpu_addr, conn->sndbuf_desc->len);
1141 			WRITE_ONCE(conn->sndbuf_desc->used, 0);
1142 		}
1143 	}
1144 	if (conn->rmb_desc) {
1145 		if (!lgr->is_smcd) {
1146 			smcr_buf_unuse(conn->rmb_desc, true, lgr);
1147 		} else {
1148 			memzero_explicit(conn->rmb_desc->cpu_addr,
1149 					 conn->rmb_desc->len + sizeof(struct smcd_cdc_msg));
1150 			WRITE_ONCE(conn->rmb_desc->used, 0);
1151 		}
1152 	}
1153 }
1154 
1155 /* remove a finished connection from its link group */
1156 void smc_conn_free(struct smc_connection *conn)
1157 {
1158 	struct smc_link_group *lgr = conn->lgr;
1159 
1160 	if (!lgr || conn->freed)
1161 		/* Connection has never been registered in a
1162 		 * link group, or has already been freed.
1163 		 */
1164 		return;
1165 
1166 	conn->freed = 1;
1167 	if (!smc_conn_lgr_valid(conn))
1168 		/* Connection has already unregistered from
1169 		 * link group.
1170 		 */
1171 		goto lgr_put;
1172 
1173 	if (lgr->is_smcd) {
1174 		if (!list_empty(&lgr->list))
1175 			smc_ism_unset_conn(conn);
1176 		tasklet_kill(&conn->rx_tsklet);
1177 	} else {
1178 		smc_cdc_wait_pend_tx_wr(conn);
1179 		if (current_work() != &conn->abort_work)
1180 			cancel_work_sync(&conn->abort_work);
1181 	}
1182 	if (!list_empty(&lgr->list)) {
1183 		smc_buf_unuse(conn, lgr); /* allow buffer reuse */
1184 		smc_lgr_unregister_conn(conn);
1185 	}
1186 
1187 	if (!lgr->conns_num)
1188 		smc_lgr_schedule_free_work(lgr);
1189 lgr_put:
1190 	if (!lgr->is_smcd)
1191 		smcr_link_put(conn->lnk); /* link_hold in smc_conn_create() */
1192 	smc_lgr_put(lgr); /* lgr_hold in smc_conn_create() */
1193 }
1194 
1195 /* unregister a link from a buf_desc */
1196 static void smcr_buf_unmap_link(struct smc_buf_desc *buf_desc, bool is_rmb,
1197 				struct smc_link *lnk)
1198 {
1199 	if (is_rmb || buf_desc->is_vm)
1200 		buf_desc->is_reg_mr[lnk->link_idx] = false;
1201 	if (!buf_desc->is_map_ib[lnk->link_idx])
1202 		return;
1203 
1204 	if ((is_rmb || buf_desc->is_vm) &&
1205 	    buf_desc->mr[lnk->link_idx]) {
1206 		smc_ib_put_memory_region(buf_desc->mr[lnk->link_idx]);
1207 		buf_desc->mr[lnk->link_idx] = NULL;
1208 	}
1209 	if (is_rmb)
1210 		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_FROM_DEVICE);
1211 	else
1212 		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_TO_DEVICE);
1213 
1214 	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
1215 	buf_desc->is_map_ib[lnk->link_idx] = false;
1216 }
1217 
1218 /* unmap all buffers of lgr for a deleted link */
1219 static void smcr_buf_unmap_lgr(struct smc_link *lnk)
1220 {
1221 	struct smc_link_group *lgr = lnk->lgr;
1222 	struct smc_buf_desc *buf_desc, *bf;
1223 	int i;
1224 
1225 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1226 		down_write(&lgr->rmbs_lock);
1227 		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list)
1228 			smcr_buf_unmap_link(buf_desc, true, lnk);
1229 		up_write(&lgr->rmbs_lock);
1230 
1231 		down_write(&lgr->sndbufs_lock);
1232 		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i],
1233 					 list)
1234 			smcr_buf_unmap_link(buf_desc, false, lnk);
1235 		up_write(&lgr->sndbufs_lock);
1236 	}
1237 }
1238 
1239 static void smcr_rtoken_clear_link(struct smc_link *lnk)
1240 {
1241 	struct smc_link_group *lgr = lnk->lgr;
1242 	int i;
1243 
1244 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1245 		lgr->rtokens[i][lnk->link_idx].rkey = 0;
1246 		lgr->rtokens[i][lnk->link_idx].dma_addr = 0;
1247 	}
1248 }
1249 
1250 static void __smcr_link_clear(struct smc_link *lnk)
1251 {
1252 	struct smc_link_group *lgr = lnk->lgr;
1253 	struct smc_ib_device *smcibdev;
1254 
1255 	smc_wr_free_link_mem(lnk);
1256 	smc_ibdev_cnt_dec(lnk);
1257 	put_device(&lnk->smcibdev->ibdev->dev);
1258 	smcibdev = lnk->smcibdev;
1259 	memset(lnk, 0, sizeof(struct smc_link));
1260 	lnk->state = SMC_LNK_UNUSED;
1261 	if (!atomic_dec_return(&smcibdev->lnk_cnt))
1262 		wake_up(&smcibdev->lnks_deleted);
1263 	smc_lgr_put(lgr); /* lgr_hold in smcr_link_init() */
1264 }
1265 
1266 /* must be called under lgr->llc_conf_mutex lock */
1267 void smcr_link_clear(struct smc_link *lnk, bool log)
1268 {
1269 	if (!lnk->lgr || lnk->clearing ||
1270 	    lnk->state == SMC_LNK_UNUSED)
1271 		return;
1272 	lnk->clearing = 1;
1273 	lnk->peer_qpn = 0;
1274 	smc_llc_link_clear(lnk, log);
1275 	smcr_buf_unmap_lgr(lnk);
1276 	smcr_rtoken_clear_link(lnk);
1277 	smc_ib_modify_qp_error(lnk);
1278 	smc_wr_free_link(lnk);
1279 	smc_ib_destroy_queue_pair(lnk);
1280 	smc_ib_dealloc_protection_domain(lnk);
1281 	smcr_link_put(lnk); /* theoretically last link_put */
1282 }
1283 
1284 void smcr_link_hold(struct smc_link *lnk)
1285 {
1286 	refcount_inc(&lnk->refcnt);
1287 }
1288 
1289 void smcr_link_put(struct smc_link *lnk)
1290 {
1291 	if (refcount_dec_and_test(&lnk->refcnt))
1292 		__smcr_link_clear(lnk);
1293 }
1294 
1295 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
1296 			  struct smc_buf_desc *buf_desc)
1297 {
1298 	int i;
1299 
1300 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1301 		smcr_buf_unmap_link(buf_desc, is_rmb, &lgr->lnk[i]);
1302 
1303 	if (!buf_desc->is_vm && buf_desc->pages)
1304 		__free_pages(buf_desc->pages, buf_desc->order);
1305 	else if (buf_desc->is_vm && buf_desc->cpu_addr)
1306 		vfree(buf_desc->cpu_addr);
1307 	kfree(buf_desc);
1308 }
1309 
1310 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
1311 			  struct smc_buf_desc *buf_desc)
1312 {
1313 	if (is_dmb) {
1314 		/* restore original buf len */
1315 		buf_desc->len += sizeof(struct smcd_cdc_msg);
1316 		smc_ism_unregister_dmb(lgr->smcd, buf_desc);
1317 	} else {
1318 		kfree(buf_desc->cpu_addr);
1319 	}
1320 	kfree(buf_desc);
1321 }
1322 
1323 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
1324 			 struct smc_buf_desc *buf_desc)
1325 {
1326 	if (lgr->is_smcd)
1327 		smcd_buf_free(lgr, is_rmb, buf_desc);
1328 	else
1329 		smcr_buf_free(lgr, is_rmb, buf_desc);
1330 }
1331 
1332 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
1333 {
1334 	struct smc_buf_desc *buf_desc, *bf_desc;
1335 	struct list_head *buf_list;
1336 	int i;
1337 
1338 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1339 		if (is_rmb)
1340 			buf_list = &lgr->rmbs[i];
1341 		else
1342 			buf_list = &lgr->sndbufs[i];
1343 		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
1344 					 list) {
1345 			list_del(&buf_desc->list);
1346 			smc_buf_free(lgr, is_rmb, buf_desc);
1347 		}
1348 	}
1349 }
1350 
1351 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
1352 {
1353 	/* free send buffers */
1354 	__smc_lgr_free_bufs(lgr, false);
1355 	/* free rmbs */
1356 	__smc_lgr_free_bufs(lgr, true);
1357 }
1358 
1359 /* won't be freed until no one accesses to lgr anymore */
1360 static void __smc_lgr_free(struct smc_link_group *lgr)
1361 {
1362 	smc_lgr_free_bufs(lgr);
1363 	if (lgr->is_smcd) {
1364 		if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
1365 			wake_up(&lgr->smcd->lgrs_deleted);
1366 	} else {
1367 		smc_wr_free_lgr_mem(lgr);
1368 		if (!atomic_dec_return(&lgr_cnt))
1369 			wake_up(&lgrs_deleted);
1370 	}
1371 	kfree(lgr);
1372 }
1373 
1374 /* remove a link group */
1375 static void smc_lgr_free(struct smc_link_group *lgr)
1376 {
1377 	int i;
1378 
1379 	if (!lgr->is_smcd) {
1380 		down_write(&lgr->llc_conf_mutex);
1381 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1382 			if (lgr->lnk[i].state != SMC_LNK_UNUSED)
1383 				smcr_link_clear(&lgr->lnk[i], false);
1384 		}
1385 		up_write(&lgr->llc_conf_mutex);
1386 		smc_llc_lgr_clear(lgr);
1387 	}
1388 
1389 	destroy_workqueue(lgr->tx_wq);
1390 	if (lgr->is_smcd) {
1391 		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
1392 		put_device(lgr->smcd->ops->get_dev(lgr->smcd));
1393 	}
1394 	smc_lgr_put(lgr); /* theoretically last lgr_put */
1395 }
1396 
1397 void smc_lgr_hold(struct smc_link_group *lgr)
1398 {
1399 	refcount_inc(&lgr->refcnt);
1400 }
1401 
1402 void smc_lgr_put(struct smc_link_group *lgr)
1403 {
1404 	if (refcount_dec_and_test(&lgr->refcnt))
1405 		__smc_lgr_free(lgr);
1406 }
1407 
1408 static void smc_sk_wake_ups(struct smc_sock *smc)
1409 {
1410 	smc->sk.sk_write_space(&smc->sk);
1411 	smc->sk.sk_data_ready(&smc->sk);
1412 	smc->sk.sk_state_change(&smc->sk);
1413 }
1414 
1415 /* kill a connection */
1416 static void smc_conn_kill(struct smc_connection *conn, bool soft)
1417 {
1418 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1419 
1420 	if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
1421 		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
1422 	else
1423 		smc_close_abort(conn);
1424 	conn->killed = 1;
1425 	smc->sk.sk_err = ECONNABORTED;
1426 	smc_sk_wake_ups(smc);
1427 	if (conn->lgr->is_smcd) {
1428 		smc_ism_unset_conn(conn);
1429 		if (soft)
1430 			tasklet_kill(&conn->rx_tsklet);
1431 		else
1432 			tasklet_unlock_wait(&conn->rx_tsklet);
1433 	} else {
1434 		smc_cdc_wait_pend_tx_wr(conn);
1435 	}
1436 	smc_lgr_unregister_conn(conn);
1437 	smc_close_active_abort(smc);
1438 }
1439 
1440 static void smc_lgr_cleanup(struct smc_link_group *lgr)
1441 {
1442 	if (lgr->is_smcd) {
1443 		smc_ism_signal_shutdown(lgr);
1444 	} else {
1445 		u32 rsn = lgr->llc_termination_rsn;
1446 
1447 		if (!rsn)
1448 			rsn = SMC_LLC_DEL_PROG_INIT_TERM;
1449 		smc_llc_send_link_delete_all(lgr, false, rsn);
1450 		smcr_lgr_link_deactivate_all(lgr);
1451 	}
1452 }
1453 
1454 /* terminate link group
1455  * @soft: true if link group shutdown can take its time
1456  *	  false if immediate link group shutdown is required
1457  */
1458 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
1459 {
1460 	struct smc_connection *conn;
1461 	struct smc_sock *smc;
1462 	struct rb_node *node;
1463 
1464 	if (lgr->terminating)
1465 		return;	/* lgr already terminating */
1466 	/* cancel free_work sync, will terminate when lgr->freeing is set */
1467 	cancel_delayed_work_sync(&lgr->free_work);
1468 	lgr->terminating = 1;
1469 
1470 	/* kill remaining link group connections */
1471 	read_lock_bh(&lgr->conns_lock);
1472 	node = rb_first(&lgr->conns_all);
1473 	while (node) {
1474 		read_unlock_bh(&lgr->conns_lock);
1475 		conn = rb_entry(node, struct smc_connection, alert_node);
1476 		smc = container_of(conn, struct smc_sock, conn);
1477 		sock_hold(&smc->sk); /* sock_put below */
1478 		lock_sock(&smc->sk);
1479 		smc_conn_kill(conn, soft);
1480 		release_sock(&smc->sk);
1481 		sock_put(&smc->sk); /* sock_hold above */
1482 		read_lock_bh(&lgr->conns_lock);
1483 		node = rb_first(&lgr->conns_all);
1484 	}
1485 	read_unlock_bh(&lgr->conns_lock);
1486 	smc_lgr_cleanup(lgr);
1487 	smc_lgr_free(lgr);
1488 }
1489 
1490 /* unlink link group and schedule termination */
1491 void smc_lgr_terminate_sched(struct smc_link_group *lgr)
1492 {
1493 	spinlock_t *lgr_lock;
1494 
1495 	smc_lgr_list_head(lgr, &lgr_lock);
1496 	spin_lock_bh(lgr_lock);
1497 	if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
1498 		spin_unlock_bh(lgr_lock);
1499 		return;	/* lgr already terminating */
1500 	}
1501 	list_del_init(&lgr->list);
1502 	lgr->freeing = 1;
1503 	spin_unlock_bh(lgr_lock);
1504 	schedule_work(&lgr->terminate_work);
1505 }
1506 
1507 /* Called when peer lgr shutdown (regularly or abnormally) is received */
1508 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
1509 {
1510 	struct smc_link_group *lgr, *l;
1511 	LIST_HEAD(lgr_free_list);
1512 
1513 	/* run common cleanup function and build free list */
1514 	spin_lock_bh(&dev->lgr_lock);
1515 	list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
1516 		if ((!peer_gid || lgr->peer_gid == peer_gid) &&
1517 		    (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
1518 			if (peer_gid) /* peer triggered termination */
1519 				lgr->peer_shutdown = 1;
1520 			list_move(&lgr->list, &lgr_free_list);
1521 			lgr->freeing = 1;
1522 		}
1523 	}
1524 	spin_unlock_bh(&dev->lgr_lock);
1525 
1526 	/* cancel the regular free workers and actually free lgrs */
1527 	list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
1528 		list_del_init(&lgr->list);
1529 		schedule_work(&lgr->terminate_work);
1530 	}
1531 }
1532 
1533 /* Called when an SMCD device is removed or the smc module is unloaded */
1534 void smc_smcd_terminate_all(struct smcd_dev *smcd)
1535 {
1536 	struct smc_link_group *lgr, *lg;
1537 	LIST_HEAD(lgr_free_list);
1538 
1539 	spin_lock_bh(&smcd->lgr_lock);
1540 	list_splice_init(&smcd->lgr_list, &lgr_free_list);
1541 	list_for_each_entry(lgr, &lgr_free_list, list)
1542 		lgr->freeing = 1;
1543 	spin_unlock_bh(&smcd->lgr_lock);
1544 
1545 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1546 		list_del_init(&lgr->list);
1547 		__smc_lgr_terminate(lgr, false);
1548 	}
1549 
1550 	if (atomic_read(&smcd->lgr_cnt))
1551 		wait_event(smcd->lgrs_deleted, !atomic_read(&smcd->lgr_cnt));
1552 }
1553 
1554 /* Called when an SMCR device is removed or the smc module is unloaded.
1555  * If smcibdev is given, all SMCR link groups using this device are terminated.
1556  * If smcibdev is NULL, all SMCR link groups are terminated.
1557  */
1558 void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
1559 {
1560 	struct smc_link_group *lgr, *lg;
1561 	LIST_HEAD(lgr_free_list);
1562 	int i;
1563 
1564 	spin_lock_bh(&smc_lgr_list.lock);
1565 	if (!smcibdev) {
1566 		list_splice_init(&smc_lgr_list.list, &lgr_free_list);
1567 		list_for_each_entry(lgr, &lgr_free_list, list)
1568 			lgr->freeing = 1;
1569 	} else {
1570 		list_for_each_entry_safe(lgr, lg, &smc_lgr_list.list, list) {
1571 			for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1572 				if (lgr->lnk[i].smcibdev == smcibdev)
1573 					smcr_link_down_cond_sched(&lgr->lnk[i]);
1574 			}
1575 		}
1576 	}
1577 	spin_unlock_bh(&smc_lgr_list.lock);
1578 
1579 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1580 		list_del_init(&lgr->list);
1581 		smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_OP_INIT_TERM);
1582 		__smc_lgr_terminate(lgr, false);
1583 	}
1584 
1585 	if (smcibdev) {
1586 		if (atomic_read(&smcibdev->lnk_cnt))
1587 			wait_event(smcibdev->lnks_deleted,
1588 				   !atomic_read(&smcibdev->lnk_cnt));
1589 	} else {
1590 		if (atomic_read(&lgr_cnt))
1591 			wait_event(lgrs_deleted, !atomic_read(&lgr_cnt));
1592 	}
1593 }
1594 
1595 /* set new lgr type and clear all asymmetric link tagging */
1596 void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type)
1597 {
1598 	char *lgr_type = "";
1599 	int i;
1600 
1601 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1602 		if (smc_link_usable(&lgr->lnk[i]))
1603 			lgr->lnk[i].link_is_asym = false;
1604 	if (lgr->type == new_type)
1605 		return;
1606 	lgr->type = new_type;
1607 
1608 	switch (lgr->type) {
1609 	case SMC_LGR_NONE:
1610 		lgr_type = "NONE";
1611 		break;
1612 	case SMC_LGR_SINGLE:
1613 		lgr_type = "SINGLE";
1614 		break;
1615 	case SMC_LGR_SYMMETRIC:
1616 		lgr_type = "SYMMETRIC";
1617 		break;
1618 	case SMC_LGR_ASYMMETRIC_PEER:
1619 		lgr_type = "ASYMMETRIC_PEER";
1620 		break;
1621 	case SMC_LGR_ASYMMETRIC_LOCAL:
1622 		lgr_type = "ASYMMETRIC_LOCAL";
1623 		break;
1624 	}
1625 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu state changed: "
1626 			    "%s, pnetid %.16s\n", SMC_LGR_ID_SIZE, &lgr->id,
1627 			    lgr->net->net_cookie, lgr_type, lgr->pnet_id);
1628 }
1629 
1630 /* set new lgr type and tag a link as asymmetric */
1631 void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
1632 			    enum smc_lgr_type new_type, int asym_lnk_idx)
1633 {
1634 	smcr_lgr_set_type(lgr, new_type);
1635 	lgr->lnk[asym_lnk_idx].link_is_asym = true;
1636 }
1637 
1638 /* abort connection, abort_work scheduled from tasklet context */
1639 static void smc_conn_abort_work(struct work_struct *work)
1640 {
1641 	struct smc_connection *conn = container_of(work,
1642 						   struct smc_connection,
1643 						   abort_work);
1644 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1645 
1646 	lock_sock(&smc->sk);
1647 	smc_conn_kill(conn, true);
1648 	release_sock(&smc->sk);
1649 	sock_put(&smc->sk); /* sock_hold done by schedulers of abort_work */
1650 }
1651 
1652 void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
1653 {
1654 	struct smc_link_group *lgr, *n;
1655 
1656 	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1657 		struct smc_link *link;
1658 
1659 		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1660 			    SMC_MAX_PNETID_LEN) ||
1661 		    lgr->type == SMC_LGR_SYMMETRIC ||
1662 		    lgr->type == SMC_LGR_ASYMMETRIC_PEER ||
1663 		    !rdma_dev_access_netns(smcibdev->ibdev, lgr->net))
1664 			continue;
1665 
1666 		/* trigger local add link processing */
1667 		link = smc_llc_usable_link(lgr);
1668 		if (link)
1669 			smc_llc_add_link_local(link);
1670 	}
1671 }
1672 
1673 /* link is down - switch connections to alternate link,
1674  * must be called under lgr->llc_conf_mutex lock
1675  */
1676 static void smcr_link_down(struct smc_link *lnk)
1677 {
1678 	struct smc_link_group *lgr = lnk->lgr;
1679 	struct smc_link *to_lnk;
1680 	int del_link_id;
1681 
1682 	if (!lgr || lnk->state == SMC_LNK_UNUSED || list_empty(&lgr->list))
1683 		return;
1684 
1685 	to_lnk = smc_switch_conns(lgr, lnk, true);
1686 	if (!to_lnk) { /* no backup link available */
1687 		smcr_link_clear(lnk, true);
1688 		return;
1689 	}
1690 	smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1691 	del_link_id = lnk->link_id;
1692 
1693 	if (lgr->role == SMC_SERV) {
1694 		/* trigger local delete link processing */
1695 		smc_llc_srv_delete_link_local(to_lnk, del_link_id);
1696 	} else {
1697 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1698 			/* another llc task is ongoing */
1699 			up_write(&lgr->llc_conf_mutex);
1700 			wait_event_timeout(lgr->llc_flow_waiter,
1701 				(list_empty(&lgr->list) ||
1702 				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
1703 				SMC_LLC_WAIT_TIME);
1704 			down_write(&lgr->llc_conf_mutex);
1705 		}
1706 		if (!list_empty(&lgr->list)) {
1707 			smc_llc_send_delete_link(to_lnk, del_link_id,
1708 						 SMC_LLC_REQ, true,
1709 						 SMC_LLC_DEL_LOST_PATH);
1710 			smcr_link_clear(lnk, true);
1711 		}
1712 		wake_up(&lgr->llc_flow_waiter);	/* wake up next waiter */
1713 	}
1714 }
1715 
1716 /* must be called under lgr->llc_conf_mutex lock */
1717 void smcr_link_down_cond(struct smc_link *lnk)
1718 {
1719 	if (smc_link_downing(&lnk->state)) {
1720 		trace_smcr_link_down(lnk, __builtin_return_address(0));
1721 		smcr_link_down(lnk);
1722 	}
1723 }
1724 
1725 /* will get the lgr->llc_conf_mutex lock */
1726 void smcr_link_down_cond_sched(struct smc_link *lnk)
1727 {
1728 	if (smc_link_downing(&lnk->state)) {
1729 		trace_smcr_link_down(lnk, __builtin_return_address(0));
1730 		schedule_work(&lnk->link_down_wrk);
1731 	}
1732 }
1733 
1734 void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport)
1735 {
1736 	struct smc_link_group *lgr, *n;
1737 	int i;
1738 
1739 	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1740 		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1741 			    SMC_MAX_PNETID_LEN))
1742 			continue; /* lgr is not affected */
1743 		if (list_empty(&lgr->list))
1744 			continue;
1745 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1746 			struct smc_link *lnk = &lgr->lnk[i];
1747 
1748 			if (smc_link_usable(lnk) &&
1749 			    lnk->smcibdev == smcibdev && lnk->ibport == ibport)
1750 				smcr_link_down_cond_sched(lnk);
1751 		}
1752 	}
1753 }
1754 
1755 static void smc_link_down_work(struct work_struct *work)
1756 {
1757 	struct smc_link *link = container_of(work, struct smc_link,
1758 					     link_down_wrk);
1759 	struct smc_link_group *lgr = link->lgr;
1760 
1761 	if (list_empty(&lgr->list))
1762 		return;
1763 	wake_up_all(&lgr->llc_msg_waiter);
1764 	down_write(&lgr->llc_conf_mutex);
1765 	smcr_link_down(link);
1766 	up_write(&lgr->llc_conf_mutex);
1767 }
1768 
1769 static int smc_vlan_by_tcpsk_walk(struct net_device *lower_dev,
1770 				  struct netdev_nested_priv *priv)
1771 {
1772 	unsigned short *vlan_id = (unsigned short *)priv->data;
1773 
1774 	if (is_vlan_dev(lower_dev)) {
1775 		*vlan_id = vlan_dev_vlan_id(lower_dev);
1776 		return 1;
1777 	}
1778 
1779 	return 0;
1780 }
1781 
1782 /* Determine vlan of internal TCP socket. */
1783 int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
1784 {
1785 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
1786 	struct netdev_nested_priv priv;
1787 	struct net_device *ndev;
1788 	int rc = 0;
1789 
1790 	ini->vlan_id = 0;
1791 	if (!dst) {
1792 		rc = -ENOTCONN;
1793 		goto out;
1794 	}
1795 	if (!dst->dev) {
1796 		rc = -ENODEV;
1797 		goto out_rel;
1798 	}
1799 
1800 	ndev = dst->dev;
1801 	if (is_vlan_dev(ndev)) {
1802 		ini->vlan_id = vlan_dev_vlan_id(ndev);
1803 		goto out_rel;
1804 	}
1805 
1806 	priv.data = (void *)&ini->vlan_id;
1807 	rtnl_lock();
1808 	netdev_walk_all_lower_dev(ndev, smc_vlan_by_tcpsk_walk, &priv);
1809 	rtnl_unlock();
1810 
1811 out_rel:
1812 	dst_release(dst);
1813 out:
1814 	return rc;
1815 }
1816 
1817 static bool smcr_lgr_match(struct smc_link_group *lgr, u8 smcr_version,
1818 			   u8 peer_systemid[],
1819 			   u8 peer_gid[],
1820 			   u8 peer_mac_v1[],
1821 			   enum smc_lgr_role role, u32 clcqpn,
1822 			   struct net *net)
1823 {
1824 	struct smc_link *lnk;
1825 	int i;
1826 
1827 	if (memcmp(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN) ||
1828 	    lgr->role != role)
1829 		return false;
1830 
1831 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1832 		lnk = &lgr->lnk[i];
1833 
1834 		if (!smc_link_active(lnk))
1835 			continue;
1836 		/* use verbs API to check netns, instead of lgr->net */
1837 		if (!rdma_dev_access_netns(lnk->smcibdev->ibdev, net))
1838 			return false;
1839 		if ((lgr->role == SMC_SERV || lnk->peer_qpn == clcqpn) &&
1840 		    !memcmp(lnk->peer_gid, peer_gid, SMC_GID_SIZE) &&
1841 		    (smcr_version == SMC_V2 ||
1842 		     !memcmp(lnk->peer_mac, peer_mac_v1, ETH_ALEN)))
1843 			return true;
1844 	}
1845 	return false;
1846 }
1847 
1848 static bool smcd_lgr_match(struct smc_link_group *lgr,
1849 			   struct smcd_dev *smcismdev, u64 peer_gid)
1850 {
1851 	return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
1852 }
1853 
1854 /* create a new SMC connection (and a new link group if necessary) */
1855 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
1856 {
1857 	struct smc_connection *conn = &smc->conn;
1858 	struct net *net = sock_net(&smc->sk);
1859 	struct list_head *lgr_list;
1860 	struct smc_link_group *lgr;
1861 	enum smc_lgr_role role;
1862 	spinlock_t *lgr_lock;
1863 	int rc = 0;
1864 
1865 	lgr_list = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_list :
1866 				  &smc_lgr_list.list;
1867 	lgr_lock = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_lock :
1868 				  &smc_lgr_list.lock;
1869 	ini->first_contact_local = 1;
1870 	role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
1871 	if (role == SMC_CLNT && ini->first_contact_peer)
1872 		/* create new link group as well */
1873 		goto create;
1874 
1875 	/* determine if an existing link group can be reused */
1876 	spin_lock_bh(lgr_lock);
1877 	list_for_each_entry(lgr, lgr_list, list) {
1878 		write_lock_bh(&lgr->conns_lock);
1879 		if ((ini->is_smcd ?
1880 		     smcd_lgr_match(lgr, ini->ism_dev[ini->ism_selected],
1881 				    ini->ism_peer_gid[ini->ism_selected]) :
1882 		     smcr_lgr_match(lgr, ini->smcr_version,
1883 				    ini->peer_systemid,
1884 				    ini->peer_gid, ini->peer_mac, role,
1885 				    ini->ib_clcqpn, net)) &&
1886 		    !lgr->sync_err &&
1887 		    (ini->smcd_version == SMC_V2 ||
1888 		     lgr->vlan_id == ini->vlan_id) &&
1889 		    (role == SMC_CLNT || ini->is_smcd ||
1890 		    (lgr->conns_num < SMC_RMBS_PER_LGR_MAX &&
1891 		      !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) {
1892 			/* link group found */
1893 			ini->first_contact_local = 0;
1894 			conn->lgr = lgr;
1895 			rc = smc_lgr_register_conn(conn, false);
1896 			write_unlock_bh(&lgr->conns_lock);
1897 			if (!rc && delayed_work_pending(&lgr->free_work))
1898 				cancel_delayed_work(&lgr->free_work);
1899 			break;
1900 		}
1901 		write_unlock_bh(&lgr->conns_lock);
1902 	}
1903 	spin_unlock_bh(lgr_lock);
1904 	if (rc)
1905 		return rc;
1906 
1907 	if (role == SMC_CLNT && !ini->first_contact_peer &&
1908 	    ini->first_contact_local) {
1909 		/* Server reuses a link group, but Client wants to start
1910 		 * a new one
1911 		 * send out_of_sync decline, reason synchr. error
1912 		 */
1913 		return SMC_CLC_DECL_SYNCERR;
1914 	}
1915 
1916 create:
1917 	if (ini->first_contact_local) {
1918 		rc = smc_lgr_create(smc, ini);
1919 		if (rc)
1920 			goto out;
1921 		lgr = conn->lgr;
1922 		write_lock_bh(&lgr->conns_lock);
1923 		rc = smc_lgr_register_conn(conn, true);
1924 		write_unlock_bh(&lgr->conns_lock);
1925 		if (rc) {
1926 			smc_lgr_cleanup_early(lgr);
1927 			goto out;
1928 		}
1929 	}
1930 	smc_lgr_hold(conn->lgr); /* lgr_put in smc_conn_free() */
1931 	if (!conn->lgr->is_smcd)
1932 		smcr_link_hold(conn->lnk); /* link_put in smc_conn_free() */
1933 	conn->freed = 0;
1934 	conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
1935 	conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
1936 	conn->urg_state = SMC_URG_READ;
1937 	init_waitqueue_head(&conn->cdc_pend_tx_wq);
1938 	INIT_WORK(&smc->conn.abort_work, smc_conn_abort_work);
1939 	if (ini->is_smcd) {
1940 		conn->rx_off = sizeof(struct smcd_cdc_msg);
1941 		smcd_cdc_rx_init(conn); /* init tasklet for this conn */
1942 	} else {
1943 		conn->rx_off = 0;
1944 	}
1945 #ifndef KERNEL_HAS_ATOMIC64
1946 	spin_lock_init(&conn->acurs_lock);
1947 #endif
1948 
1949 out:
1950 	return rc;
1951 }
1952 
1953 #define SMCD_DMBE_SIZES		6 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
1954 #define SMCR_RMBE_SIZES		5 /* 0 -> 16KB, 1 -> 32KB, .. 5 -> 512KB */
1955 
1956 /* convert the RMB size into the compressed notation (minimum 16K, see
1957  * SMCD/R_DMBE_SIZES.
1958  * In contrast to plain ilog2, this rounds towards the next power of 2,
1959  * so the socket application gets at least its desired sndbuf / rcvbuf size.
1960  */
1961 static u8 smc_compress_bufsize(int size, bool is_smcd, bool is_rmb)
1962 {
1963 	const unsigned int max_scat = SG_MAX_SINGLE_ALLOC * PAGE_SIZE;
1964 	u8 compressed;
1965 
1966 	if (size <= SMC_BUF_MIN_SIZE)
1967 		return 0;
1968 
1969 	size = (size - 1) >> 14;  /* convert to 16K multiple */
1970 	compressed = min_t(u8, ilog2(size) + 1,
1971 			   is_smcd ? SMCD_DMBE_SIZES : SMCR_RMBE_SIZES);
1972 
1973 	if (!is_smcd && is_rmb)
1974 		/* RMBs are backed by & limited to max size of scatterlists */
1975 		compressed = min_t(u8, compressed, ilog2(max_scat >> 14));
1976 
1977 	return compressed;
1978 }
1979 
1980 /* convert the RMB size from compressed notation into integer */
1981 int smc_uncompress_bufsize(u8 compressed)
1982 {
1983 	u32 size;
1984 
1985 	size = 0x00000001 << (((int)compressed) + 14);
1986 	return (int)size;
1987 }
1988 
1989 /* try to reuse a sndbuf or rmb description slot for a certain
1990  * buffer size; if not available, return NULL
1991  */
1992 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
1993 					     struct rw_semaphore *lock,
1994 					     struct list_head *buf_list)
1995 {
1996 	struct smc_buf_desc *buf_slot;
1997 
1998 	down_read(lock);
1999 	list_for_each_entry(buf_slot, buf_list, list) {
2000 		if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
2001 			up_read(lock);
2002 			return buf_slot;
2003 		}
2004 	}
2005 	up_read(lock);
2006 	return NULL;
2007 }
2008 
2009 /* one of the conditions for announcing a receiver's current window size is
2010  * that it "results in a minimum increase in the window size of 10% of the
2011  * receive buffer space" [RFC7609]
2012  */
2013 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
2014 {
2015 	return max_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
2016 }
2017 
2018 /* map an buf to a link */
2019 static int smcr_buf_map_link(struct smc_buf_desc *buf_desc, bool is_rmb,
2020 			     struct smc_link *lnk)
2021 {
2022 	int rc, i, nents, offset, buf_size, size, access_flags;
2023 	struct scatterlist *sg;
2024 	void *buf;
2025 
2026 	if (buf_desc->is_map_ib[lnk->link_idx])
2027 		return 0;
2028 
2029 	if (buf_desc->is_vm) {
2030 		buf = buf_desc->cpu_addr;
2031 		buf_size = buf_desc->len;
2032 		offset = offset_in_page(buf_desc->cpu_addr);
2033 		nents = PAGE_ALIGN(buf_size + offset) / PAGE_SIZE;
2034 	} else {
2035 		nents = 1;
2036 	}
2037 
2038 	rc = sg_alloc_table(&buf_desc->sgt[lnk->link_idx], nents, GFP_KERNEL);
2039 	if (rc)
2040 		return rc;
2041 
2042 	if (buf_desc->is_vm) {
2043 		/* virtually contiguous buffer */
2044 		for_each_sg(buf_desc->sgt[lnk->link_idx].sgl, sg, nents, i) {
2045 			size = min_t(int, PAGE_SIZE - offset, buf_size);
2046 			sg_set_page(sg, vmalloc_to_page(buf), size, offset);
2047 			buf += size / sizeof(*buf);
2048 			buf_size -= size;
2049 			offset = 0;
2050 		}
2051 	} else {
2052 		/* physically contiguous buffer */
2053 		sg_set_buf(buf_desc->sgt[lnk->link_idx].sgl,
2054 			   buf_desc->cpu_addr, buf_desc->len);
2055 	}
2056 
2057 	/* map sg table to DMA address */
2058 	rc = smc_ib_buf_map_sg(lnk, buf_desc,
2059 			       is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2060 	/* SMC protocol depends on mapping to one DMA address only */
2061 	if (rc != nents) {
2062 		rc = -EAGAIN;
2063 		goto free_table;
2064 	}
2065 
2066 	buf_desc->is_dma_need_sync |=
2067 		smc_ib_is_sg_need_sync(lnk, buf_desc) << lnk->link_idx;
2068 
2069 	if (is_rmb || buf_desc->is_vm) {
2070 		/* create a new memory region for the RMB or vzalloced sndbuf */
2071 		access_flags = is_rmb ?
2072 			       IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
2073 			       IB_ACCESS_LOCAL_WRITE;
2074 
2075 		rc = smc_ib_get_memory_region(lnk->roce_pd, access_flags,
2076 					      buf_desc, lnk->link_idx);
2077 		if (rc)
2078 			goto buf_unmap;
2079 		smc_ib_sync_sg_for_device(lnk, buf_desc,
2080 					  is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2081 	}
2082 	buf_desc->is_map_ib[lnk->link_idx] = true;
2083 	return 0;
2084 
2085 buf_unmap:
2086 	smc_ib_buf_unmap_sg(lnk, buf_desc,
2087 			    is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2088 free_table:
2089 	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
2090 	return rc;
2091 }
2092 
2093 /* register a new buf on IB device, rmb or vzalloced sndbuf
2094  * must be called under lgr->llc_conf_mutex lock
2095  */
2096 int smcr_link_reg_buf(struct smc_link *link, struct smc_buf_desc *buf_desc)
2097 {
2098 	if (list_empty(&link->lgr->list))
2099 		return -ENOLINK;
2100 	if (!buf_desc->is_reg_mr[link->link_idx]) {
2101 		/* register memory region for new buf */
2102 		if (buf_desc->is_vm)
2103 			buf_desc->mr[link->link_idx]->iova =
2104 				(uintptr_t)buf_desc->cpu_addr;
2105 		if (smc_wr_reg_send(link, buf_desc->mr[link->link_idx])) {
2106 			buf_desc->is_reg_err = true;
2107 			return -EFAULT;
2108 		}
2109 		buf_desc->is_reg_mr[link->link_idx] = true;
2110 	}
2111 	return 0;
2112 }
2113 
2114 static int _smcr_buf_map_lgr(struct smc_link *lnk, struct rw_semaphore *lock,
2115 			     struct list_head *lst, bool is_rmb)
2116 {
2117 	struct smc_buf_desc *buf_desc, *bf;
2118 	int rc = 0;
2119 
2120 	down_write(lock);
2121 	list_for_each_entry_safe(buf_desc, bf, lst, list) {
2122 		if (!buf_desc->used)
2123 			continue;
2124 		rc = smcr_buf_map_link(buf_desc, is_rmb, lnk);
2125 		if (rc)
2126 			goto out;
2127 	}
2128 out:
2129 	up_write(lock);
2130 	return rc;
2131 }
2132 
2133 /* map all used buffers of lgr for a new link */
2134 int smcr_buf_map_lgr(struct smc_link *lnk)
2135 {
2136 	struct smc_link_group *lgr = lnk->lgr;
2137 	int i, rc = 0;
2138 
2139 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2140 		rc = _smcr_buf_map_lgr(lnk, &lgr->rmbs_lock,
2141 				       &lgr->rmbs[i], true);
2142 		if (rc)
2143 			return rc;
2144 		rc = _smcr_buf_map_lgr(lnk, &lgr->sndbufs_lock,
2145 				       &lgr->sndbufs[i], false);
2146 		if (rc)
2147 			return rc;
2148 	}
2149 	return 0;
2150 }
2151 
2152 /* register all used buffers of lgr for a new link,
2153  * must be called under lgr->llc_conf_mutex lock
2154  */
2155 int smcr_buf_reg_lgr(struct smc_link *lnk)
2156 {
2157 	struct smc_link_group *lgr = lnk->lgr;
2158 	struct smc_buf_desc *buf_desc, *bf;
2159 	int i, rc = 0;
2160 
2161 	/* reg all RMBs for a new link */
2162 	down_write(&lgr->rmbs_lock);
2163 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2164 		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list) {
2165 			if (!buf_desc->used)
2166 				continue;
2167 			rc = smcr_link_reg_buf(lnk, buf_desc);
2168 			if (rc) {
2169 				up_write(&lgr->rmbs_lock);
2170 				return rc;
2171 			}
2172 		}
2173 	}
2174 	up_write(&lgr->rmbs_lock);
2175 
2176 	if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2177 		return rc;
2178 
2179 	/* reg all vzalloced sndbufs for a new link */
2180 	down_write(&lgr->sndbufs_lock);
2181 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2182 		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i], list) {
2183 			if (!buf_desc->used || !buf_desc->is_vm)
2184 				continue;
2185 			rc = smcr_link_reg_buf(lnk, buf_desc);
2186 			if (rc) {
2187 				up_write(&lgr->sndbufs_lock);
2188 				return rc;
2189 			}
2190 		}
2191 	}
2192 	up_write(&lgr->sndbufs_lock);
2193 	return rc;
2194 }
2195 
2196 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
2197 						bool is_rmb, int bufsize)
2198 {
2199 	struct smc_buf_desc *buf_desc;
2200 
2201 	/* try to alloc a new buffer */
2202 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2203 	if (!buf_desc)
2204 		return ERR_PTR(-ENOMEM);
2205 
2206 	switch (lgr->buf_type) {
2207 	case SMCR_PHYS_CONT_BUFS:
2208 	case SMCR_MIXED_BUFS:
2209 		buf_desc->order = get_order(bufsize);
2210 		buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
2211 					      __GFP_NOMEMALLOC | __GFP_COMP |
2212 					      __GFP_NORETRY | __GFP_ZERO,
2213 					      buf_desc->order);
2214 		if (buf_desc->pages) {
2215 			buf_desc->cpu_addr =
2216 				(void *)page_address(buf_desc->pages);
2217 			buf_desc->len = bufsize;
2218 			buf_desc->is_vm = false;
2219 			break;
2220 		}
2221 		if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2222 			goto out;
2223 		fallthrough;	// try virtually continguous buf
2224 	case SMCR_VIRT_CONT_BUFS:
2225 		buf_desc->order = get_order(bufsize);
2226 		buf_desc->cpu_addr = vzalloc(PAGE_SIZE << buf_desc->order);
2227 		if (!buf_desc->cpu_addr)
2228 			goto out;
2229 		buf_desc->pages = NULL;
2230 		buf_desc->len = bufsize;
2231 		buf_desc->is_vm = true;
2232 		break;
2233 	}
2234 	return buf_desc;
2235 
2236 out:
2237 	kfree(buf_desc);
2238 	return ERR_PTR(-EAGAIN);
2239 }
2240 
2241 /* map buf_desc on all usable links,
2242  * unused buffers stay mapped as long as the link is up
2243  */
2244 static int smcr_buf_map_usable_links(struct smc_link_group *lgr,
2245 				     struct smc_buf_desc *buf_desc, bool is_rmb)
2246 {
2247 	int i, rc = 0, cnt = 0;
2248 
2249 	/* protect against parallel link reconfiguration */
2250 	down_read(&lgr->llc_conf_mutex);
2251 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2252 		struct smc_link *lnk = &lgr->lnk[i];
2253 
2254 		if (!smc_link_usable(lnk))
2255 			continue;
2256 		if (smcr_buf_map_link(buf_desc, is_rmb, lnk)) {
2257 			rc = -ENOMEM;
2258 			goto out;
2259 		}
2260 		cnt++;
2261 	}
2262 out:
2263 	up_read(&lgr->llc_conf_mutex);
2264 	if (!rc && !cnt)
2265 		rc = -EINVAL;
2266 	return rc;
2267 }
2268 
2269 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
2270 						bool is_dmb, int bufsize)
2271 {
2272 	struct smc_buf_desc *buf_desc;
2273 	int rc;
2274 
2275 	/* try to alloc a new DMB */
2276 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2277 	if (!buf_desc)
2278 		return ERR_PTR(-ENOMEM);
2279 	if (is_dmb) {
2280 		rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
2281 		if (rc) {
2282 			kfree(buf_desc);
2283 			if (rc == -ENOMEM)
2284 				return ERR_PTR(-EAGAIN);
2285 			if (rc == -ENOSPC)
2286 				return ERR_PTR(-ENOSPC);
2287 			return ERR_PTR(-EIO);
2288 		}
2289 		buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
2290 		/* CDC header stored in buf. So, pretend it was smaller */
2291 		buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
2292 	} else {
2293 		buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
2294 					     __GFP_NOWARN | __GFP_NORETRY |
2295 					     __GFP_NOMEMALLOC);
2296 		if (!buf_desc->cpu_addr) {
2297 			kfree(buf_desc);
2298 			return ERR_PTR(-EAGAIN);
2299 		}
2300 		buf_desc->len = bufsize;
2301 	}
2302 	return buf_desc;
2303 }
2304 
2305 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
2306 {
2307 	struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
2308 	struct smc_connection *conn = &smc->conn;
2309 	struct smc_link_group *lgr = conn->lgr;
2310 	struct list_head *buf_list;
2311 	int bufsize, bufsize_short;
2312 	struct rw_semaphore *lock;	/* lock buffer list */
2313 	bool is_dgraded = false;
2314 	int sk_buf_size;
2315 
2316 	if (is_rmb)
2317 		/* use socket recv buffer size (w/o overhead) as start value */
2318 		sk_buf_size = smc->sk.sk_rcvbuf;
2319 	else
2320 		/* use socket send buffer size (w/o overhead) as start value */
2321 		sk_buf_size = smc->sk.sk_sndbuf;
2322 
2323 	for (bufsize_short = smc_compress_bufsize(sk_buf_size, is_smcd, is_rmb);
2324 	     bufsize_short >= 0; bufsize_short--) {
2325 		if (is_rmb) {
2326 			lock = &lgr->rmbs_lock;
2327 			buf_list = &lgr->rmbs[bufsize_short];
2328 		} else {
2329 			lock = &lgr->sndbufs_lock;
2330 			buf_list = &lgr->sndbufs[bufsize_short];
2331 		}
2332 		bufsize = smc_uncompress_bufsize(bufsize_short);
2333 
2334 		/* check for reusable slot in the link group */
2335 		buf_desc = smc_buf_get_slot(bufsize_short, lock, buf_list);
2336 		if (buf_desc) {
2337 			buf_desc->is_dma_need_sync = 0;
2338 			SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, bufsize);
2339 			SMC_STAT_BUF_REUSE(smc, is_smcd, is_rmb);
2340 			break; /* found reusable slot */
2341 		}
2342 
2343 		if (is_smcd)
2344 			buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
2345 		else
2346 			buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
2347 
2348 		if (PTR_ERR(buf_desc) == -ENOMEM)
2349 			break;
2350 		if (IS_ERR(buf_desc)) {
2351 			if (!is_dgraded) {
2352 				is_dgraded = true;
2353 				SMC_STAT_RMB_DOWNGRADED(smc, is_smcd, is_rmb);
2354 			}
2355 			continue;
2356 		}
2357 
2358 		SMC_STAT_RMB_ALLOC(smc, is_smcd, is_rmb);
2359 		SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, bufsize);
2360 		buf_desc->used = 1;
2361 		down_write(lock);
2362 		list_add(&buf_desc->list, buf_list);
2363 		up_write(lock);
2364 		break; /* found */
2365 	}
2366 
2367 	if (IS_ERR(buf_desc))
2368 		return PTR_ERR(buf_desc);
2369 
2370 	if (!is_smcd) {
2371 		if (smcr_buf_map_usable_links(lgr, buf_desc, is_rmb)) {
2372 			smcr_buf_unuse(buf_desc, is_rmb, lgr);
2373 			return -ENOMEM;
2374 		}
2375 	}
2376 
2377 	if (is_rmb) {
2378 		conn->rmb_desc = buf_desc;
2379 		conn->rmbe_size_short = bufsize_short;
2380 		smc->sk.sk_rcvbuf = bufsize;
2381 		atomic_set(&conn->bytes_to_rcv, 0);
2382 		conn->rmbe_update_limit =
2383 			smc_rmb_wnd_update_limit(buf_desc->len);
2384 		if (is_smcd)
2385 			smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
2386 	} else {
2387 		conn->sndbuf_desc = buf_desc;
2388 		smc->sk.sk_sndbuf = bufsize;
2389 		atomic_set(&conn->sndbuf_space, bufsize);
2390 	}
2391 	return 0;
2392 }
2393 
2394 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
2395 {
2396 	if (!conn->sndbuf_desc->is_dma_need_sync)
2397 		return;
2398 	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd ||
2399 	    !smc_link_active(conn->lnk))
2400 		return;
2401 	smc_ib_sync_sg_for_device(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);
2402 }
2403 
2404 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
2405 {
2406 	int i;
2407 
2408 	if (!conn->rmb_desc->is_dma_need_sync)
2409 		return;
2410 	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd)
2411 		return;
2412 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2413 		if (!smc_link_active(&conn->lgr->lnk[i]))
2414 			continue;
2415 		smc_ib_sync_sg_for_cpu(&conn->lgr->lnk[i], conn->rmb_desc,
2416 				       DMA_FROM_DEVICE);
2417 	}
2418 }
2419 
2420 /* create the send and receive buffer for an SMC socket;
2421  * receive buffers are called RMBs;
2422  * (even though the SMC protocol allows more than one RMB-element per RMB,
2423  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
2424  * extra RMB for every connection in a link group
2425  */
2426 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
2427 {
2428 	int rc;
2429 
2430 	/* create send buffer */
2431 	rc = __smc_buf_create(smc, is_smcd, false);
2432 	if (rc)
2433 		return rc;
2434 	/* create rmb */
2435 	rc = __smc_buf_create(smc, is_smcd, true);
2436 	if (rc) {
2437 		down_write(&smc->conn.lgr->sndbufs_lock);
2438 		list_del(&smc->conn.sndbuf_desc->list);
2439 		up_write(&smc->conn.lgr->sndbufs_lock);
2440 		smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
2441 		smc->conn.sndbuf_desc = NULL;
2442 	}
2443 	return rc;
2444 }
2445 
2446 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
2447 {
2448 	int i;
2449 
2450 	for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
2451 		if (!test_and_set_bit(i, lgr->rtokens_used_mask))
2452 			return i;
2453 	}
2454 	return -ENOSPC;
2455 }
2456 
2457 static int smc_rtoken_find_by_link(struct smc_link_group *lgr, int lnk_idx,
2458 				   u32 rkey)
2459 {
2460 	int i;
2461 
2462 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2463 		if (test_bit(i, lgr->rtokens_used_mask) &&
2464 		    lgr->rtokens[i][lnk_idx].rkey == rkey)
2465 			return i;
2466 	}
2467 	return -ENOENT;
2468 }
2469 
2470 /* set rtoken for a new link to an existing rmb */
2471 void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
2472 		    __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey)
2473 {
2474 	int rtok_idx;
2475 
2476 	rtok_idx = smc_rtoken_find_by_link(lgr, link_idx, ntohl(nw_rkey_known));
2477 	if (rtok_idx == -ENOENT)
2478 		return;
2479 	lgr->rtokens[rtok_idx][link_idx_new].rkey = ntohl(nw_rkey);
2480 	lgr->rtokens[rtok_idx][link_idx_new].dma_addr = be64_to_cpu(nw_vaddr);
2481 }
2482 
2483 /* set rtoken for a new link whose link_id is given */
2484 void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
2485 		     __be64 nw_vaddr, __be32 nw_rkey)
2486 {
2487 	u64 dma_addr = be64_to_cpu(nw_vaddr);
2488 	u32 rkey = ntohl(nw_rkey);
2489 	bool found = false;
2490 	int link_idx;
2491 
2492 	for (link_idx = 0; link_idx < SMC_LINKS_PER_LGR_MAX; link_idx++) {
2493 		if (lgr->lnk[link_idx].link_id == link_id) {
2494 			found = true;
2495 			break;
2496 		}
2497 	}
2498 	if (!found)
2499 		return;
2500 	lgr->rtokens[rtok_idx][link_idx].rkey = rkey;
2501 	lgr->rtokens[rtok_idx][link_idx].dma_addr = dma_addr;
2502 }
2503 
2504 /* add a new rtoken from peer */
2505 int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey)
2506 {
2507 	struct smc_link_group *lgr = smc_get_lgr(lnk);
2508 	u64 dma_addr = be64_to_cpu(nw_vaddr);
2509 	u32 rkey = ntohl(nw_rkey);
2510 	int i;
2511 
2512 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2513 		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2514 		    lgr->rtokens[i][lnk->link_idx].dma_addr == dma_addr &&
2515 		    test_bit(i, lgr->rtokens_used_mask)) {
2516 			/* already in list */
2517 			return i;
2518 		}
2519 	}
2520 	i = smc_rmb_reserve_rtoken_idx(lgr);
2521 	if (i < 0)
2522 		return i;
2523 	lgr->rtokens[i][lnk->link_idx].rkey = rkey;
2524 	lgr->rtokens[i][lnk->link_idx].dma_addr = dma_addr;
2525 	return i;
2526 }
2527 
2528 /* delete an rtoken from all links */
2529 int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey)
2530 {
2531 	struct smc_link_group *lgr = smc_get_lgr(lnk);
2532 	u32 rkey = ntohl(nw_rkey);
2533 	int i, j;
2534 
2535 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2536 		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2537 		    test_bit(i, lgr->rtokens_used_mask)) {
2538 			for (j = 0; j < SMC_LINKS_PER_LGR_MAX; j++) {
2539 				lgr->rtokens[i][j].rkey = 0;
2540 				lgr->rtokens[i][j].dma_addr = 0;
2541 			}
2542 			clear_bit(i, lgr->rtokens_used_mask);
2543 			return 0;
2544 		}
2545 	}
2546 	return -ENOENT;
2547 }
2548 
2549 /* save rkey and dma_addr received from peer during clc handshake */
2550 int smc_rmb_rtoken_handling(struct smc_connection *conn,
2551 			    struct smc_link *lnk,
2552 			    struct smc_clc_msg_accept_confirm *clc)
2553 {
2554 	conn->rtoken_idx = smc_rtoken_add(lnk, clc->r0.rmb_dma_addr,
2555 					  clc->r0.rmb_rkey);
2556 	if (conn->rtoken_idx < 0)
2557 		return conn->rtoken_idx;
2558 	return 0;
2559 }
2560 
2561 static void smc_core_going_away(void)
2562 {
2563 	struct smc_ib_device *smcibdev;
2564 	struct smcd_dev *smcd;
2565 
2566 	mutex_lock(&smc_ib_devices.mutex);
2567 	list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
2568 		int i;
2569 
2570 		for (i = 0; i < SMC_MAX_PORTS; i++)
2571 			set_bit(i, smcibdev->ports_going_away);
2572 	}
2573 	mutex_unlock(&smc_ib_devices.mutex);
2574 
2575 	mutex_lock(&smcd_dev_list.mutex);
2576 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
2577 		smcd->going_away = 1;
2578 	}
2579 	mutex_unlock(&smcd_dev_list.mutex);
2580 }
2581 
2582 /* Clean up all SMC link groups */
2583 static void smc_lgrs_shutdown(void)
2584 {
2585 	struct smcd_dev *smcd;
2586 
2587 	smc_core_going_away();
2588 
2589 	smc_smcr_terminate_all(NULL);
2590 
2591 	mutex_lock(&smcd_dev_list.mutex);
2592 	list_for_each_entry(smcd, &smcd_dev_list.list, list)
2593 		smc_smcd_terminate_all(smcd);
2594 	mutex_unlock(&smcd_dev_list.mutex);
2595 }
2596 
2597 static int smc_core_reboot_event(struct notifier_block *this,
2598 				 unsigned long event, void *ptr)
2599 {
2600 	smc_lgrs_shutdown();
2601 	smc_ib_unregister_client();
2602 	smc_ism_exit();
2603 	return 0;
2604 }
2605 
2606 static struct notifier_block smc_reboot_notifier = {
2607 	.notifier_call = smc_core_reboot_event,
2608 };
2609 
2610 int __init smc_core_init(void)
2611 {
2612 	return register_reboot_notifier(&smc_reboot_notifier);
2613 }
2614 
2615 /* Called (from smc_exit) when module is removed */
2616 void smc_core_exit(void)
2617 {
2618 	unregister_reboot_notifier(&smc_reboot_notifier);
2619 	smc_lgrs_shutdown();
2620 }
2621