xref: /openbmc/linux/net/smc/smc_core.c (revision faffb083)
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 nlattr *attrs;
504 	void *nlh;
505 
506 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
507 			  &smc_gen_nl_family, NLM_F_MULTI,
508 			  SMC_NETLINK_GET_LGR_SMCD);
509 	if (!nlh)
510 		goto errmsg;
511 
512 	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCD);
513 	if (!attrs)
514 		goto errout;
515 
516 	if (nla_put_u32(skb, SMC_NLA_LGR_D_ID, *((u32 *)&lgr->id)))
517 		goto errattr;
518 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_GID, lgr->smcd->local_gid,
519 			      SMC_NLA_LGR_D_PAD))
520 		goto errattr;
521 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_PEER_GID, lgr->peer_gid,
522 			      SMC_NLA_LGR_D_PAD))
523 		goto errattr;
524 	if (nla_put_u8(skb, SMC_NLA_LGR_D_VLAN_ID, lgr->vlan_id))
525 		goto errattr;
526 	if (nla_put_u32(skb, SMC_NLA_LGR_D_CONNS_NUM, lgr->conns_num))
527 		goto errattr;
528 	if (nla_put_u32(skb, SMC_NLA_LGR_D_CHID, smc_ism_get_chid(lgr->smcd)))
529 		goto errattr;
530 	memcpy(smc_pnet, lgr->smcd->pnetid, SMC_MAX_PNETID_LEN);
531 	smc_pnet[SMC_MAX_PNETID_LEN] = 0;
532 	if (nla_put_string(skb, SMC_NLA_LGR_D_PNETID, smc_pnet))
533 		goto errattr;
534 	if (lgr->smc_version > SMC_V1) {
535 		struct nlattr *v2_attrs;
536 
537 		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_D_V2_COMMON);
538 		if (!v2_attrs)
539 			goto errattr;
540 		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
541 			goto errattr;
542 	}
543 	nla_nest_end(skb, attrs);
544 	genlmsg_end(skb, nlh);
545 	return 0;
546 
547 errattr:
548 	nla_nest_cancel(skb, attrs);
549 errout:
550 	genlmsg_cancel(skb, nlh);
551 errmsg:
552 	return -EMSGSIZE;
553 }
554 
555 static int smc_nl_handle_smcd_lgr(struct smcd_dev *dev,
556 				  struct sk_buff *skb,
557 				  struct netlink_callback *cb)
558 {
559 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
560 	struct smc_link_group *lgr;
561 	int snum = cb_ctx->pos[1];
562 	int rc = 0, num = 0;
563 
564 	spin_lock_bh(&dev->lgr_lock);
565 	list_for_each_entry(lgr, &dev->lgr_list, list) {
566 		if (!lgr->is_smcd)
567 			continue;
568 		if (num < snum)
569 			goto next;
570 		rc = smc_nl_fill_smcd_lgr(lgr, skb, cb);
571 		if (rc)
572 			goto errout;
573 next:
574 		num++;
575 	}
576 errout:
577 	spin_unlock_bh(&dev->lgr_lock);
578 	cb_ctx->pos[1] = num;
579 	return rc;
580 }
581 
582 static int smc_nl_fill_smcd_dev(struct smcd_dev_list *dev_list,
583 				struct sk_buff *skb,
584 				struct netlink_callback *cb)
585 {
586 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
587 	struct smcd_dev *smcd_dev;
588 	int snum = cb_ctx->pos[0];
589 	int rc = 0, num = 0;
590 
591 	mutex_lock(&dev_list->mutex);
592 	list_for_each_entry(smcd_dev, &dev_list->list, list) {
593 		if (list_empty(&smcd_dev->lgr_list))
594 			continue;
595 		if (num < snum)
596 			goto next;
597 		rc = smc_nl_handle_smcd_lgr(smcd_dev, skb, cb);
598 		if (rc)
599 			goto errout;
600 next:
601 		num++;
602 	}
603 errout:
604 	mutex_unlock(&dev_list->mutex);
605 	cb_ctx->pos[0] = num;
606 	return rc;
607 }
608 
609 int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
610 {
611 	bool list_links = false;
612 
613 	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
614 	return skb->len;
615 }
616 
617 int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb)
618 {
619 	bool list_links = true;
620 
621 	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
622 	return skb->len;
623 }
624 
625 int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
626 {
627 	smc_nl_fill_smcd_dev(&smcd_dev_list, skb, cb);
628 	return skb->len;
629 }
630 
631 void smc_lgr_cleanup_early(struct smc_link_group *lgr)
632 {
633 	spinlock_t *lgr_lock;
634 
635 	if (!lgr)
636 		return;
637 
638 	smc_lgr_list_head(lgr, &lgr_lock);
639 	spin_lock_bh(lgr_lock);
640 	/* do not use this link group for new connections */
641 	if (!list_empty(&lgr->list))
642 		list_del_init(&lgr->list);
643 	spin_unlock_bh(lgr_lock);
644 	__smc_lgr_terminate(lgr, true);
645 }
646 
647 static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
648 {
649 	int i;
650 
651 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
652 		struct smc_link *lnk = &lgr->lnk[i];
653 
654 		if (smc_link_sendable(lnk))
655 			lnk->state = SMC_LNK_INACTIVE;
656 	}
657 	wake_up_all(&lgr->llc_msg_waiter);
658 	wake_up_all(&lgr->llc_flow_waiter);
659 }
660 
661 static void smc_lgr_free(struct smc_link_group *lgr);
662 
663 static void smc_lgr_free_work(struct work_struct *work)
664 {
665 	struct smc_link_group *lgr = container_of(to_delayed_work(work),
666 						  struct smc_link_group,
667 						  free_work);
668 	spinlock_t *lgr_lock;
669 	bool conns;
670 
671 	smc_lgr_list_head(lgr, &lgr_lock);
672 	spin_lock_bh(lgr_lock);
673 	if (lgr->freeing) {
674 		spin_unlock_bh(lgr_lock);
675 		return;
676 	}
677 	read_lock_bh(&lgr->conns_lock);
678 	conns = RB_EMPTY_ROOT(&lgr->conns_all);
679 	read_unlock_bh(&lgr->conns_lock);
680 	if (!conns) { /* number of lgr connections is no longer zero */
681 		spin_unlock_bh(lgr_lock);
682 		return;
683 	}
684 	list_del_init(&lgr->list); /* remove from smc_lgr_list */
685 	lgr->freeing = 1; /* this instance does the freeing, no new schedule */
686 	spin_unlock_bh(lgr_lock);
687 	cancel_delayed_work(&lgr->free_work);
688 
689 	if (!lgr->is_smcd && !lgr->terminating)
690 		smc_llc_send_link_delete_all(lgr, true,
691 					     SMC_LLC_DEL_PROG_INIT_TERM);
692 	if (lgr->is_smcd && !lgr->terminating)
693 		smc_ism_signal_shutdown(lgr);
694 	if (!lgr->is_smcd)
695 		smcr_lgr_link_deactivate_all(lgr);
696 	smc_lgr_free(lgr);
697 }
698 
699 static void smc_lgr_terminate_work(struct work_struct *work)
700 {
701 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
702 						  terminate_work);
703 
704 	__smc_lgr_terminate(lgr, true);
705 }
706 
707 /* return next unique link id for the lgr */
708 static u8 smcr_next_link_id(struct smc_link_group *lgr)
709 {
710 	u8 link_id;
711 	int i;
712 
713 	while (1) {
714 again:
715 		link_id = ++lgr->next_link_id;
716 		if (!link_id)	/* skip zero as link_id */
717 			link_id = ++lgr->next_link_id;
718 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
719 			if (smc_link_usable(&lgr->lnk[i]) &&
720 			    lgr->lnk[i].link_id == link_id)
721 				goto again;
722 		}
723 		break;
724 	}
725 	return link_id;
726 }
727 
728 static void smcr_copy_dev_info_to_link(struct smc_link *link)
729 {
730 	struct smc_ib_device *smcibdev = link->smcibdev;
731 
732 	snprintf(link->ibname, sizeof(link->ibname), "%s",
733 		 smcibdev->ibdev->name);
734 	link->ndev_ifidx = smcibdev->ndev_ifidx[link->ibport - 1];
735 }
736 
737 int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
738 		   u8 link_idx, struct smc_init_info *ini)
739 {
740 	struct smc_ib_device *smcibdev;
741 	u8 rndvec[3];
742 	int rc;
743 
744 	if (lgr->smc_version == SMC_V2) {
745 		lnk->smcibdev = ini->smcrv2.ib_dev_v2;
746 		lnk->ibport = ini->smcrv2.ib_port_v2;
747 	} else {
748 		lnk->smcibdev = ini->ib_dev;
749 		lnk->ibport = ini->ib_port;
750 	}
751 	get_device(&lnk->smcibdev->ibdev->dev);
752 	atomic_inc(&lnk->smcibdev->lnk_cnt);
753 	refcount_set(&lnk->refcnt, 1); /* link refcnt is set to 1 */
754 	lnk->clearing = 0;
755 	lnk->path_mtu = lnk->smcibdev->pattr[lnk->ibport - 1].active_mtu;
756 	lnk->link_id = smcr_next_link_id(lgr);
757 	lnk->lgr = lgr;
758 	smc_lgr_hold(lgr); /* lgr_put in smcr_link_clear() */
759 	lnk->link_idx = link_idx;
760 	lnk->wr_rx_id_compl = 0;
761 	smc_ibdev_cnt_inc(lnk);
762 	smcr_copy_dev_info_to_link(lnk);
763 	atomic_set(&lnk->conn_cnt, 0);
764 	smc_llc_link_set_uid(lnk);
765 	INIT_WORK(&lnk->link_down_wrk, smc_link_down_work);
766 	if (!lnk->smcibdev->initialized) {
767 		rc = (int)smc_ib_setup_per_ibdev(lnk->smcibdev);
768 		if (rc)
769 			goto out;
770 	}
771 	get_random_bytes(rndvec, sizeof(rndvec));
772 	lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
773 		(rndvec[2] << 16);
774 	rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
775 				  ini->vlan_id, lnk->gid, &lnk->sgid_index,
776 				  lgr->smc_version == SMC_V2 ?
777 						  &ini->smcrv2 : NULL);
778 	if (rc)
779 		goto out;
780 	rc = smc_llc_link_init(lnk);
781 	if (rc)
782 		goto out;
783 	rc = smc_wr_alloc_link_mem(lnk);
784 	if (rc)
785 		goto clear_llc_lnk;
786 	rc = smc_ib_create_protection_domain(lnk);
787 	if (rc)
788 		goto free_link_mem;
789 	rc = smc_ib_create_queue_pair(lnk);
790 	if (rc)
791 		goto dealloc_pd;
792 	rc = smc_wr_create_link(lnk);
793 	if (rc)
794 		goto destroy_qp;
795 	lnk->state = SMC_LNK_ACTIVATING;
796 	return 0;
797 
798 destroy_qp:
799 	smc_ib_destroy_queue_pair(lnk);
800 dealloc_pd:
801 	smc_ib_dealloc_protection_domain(lnk);
802 free_link_mem:
803 	smc_wr_free_link_mem(lnk);
804 clear_llc_lnk:
805 	smc_llc_link_clear(lnk, false);
806 out:
807 	smc_ibdev_cnt_dec(lnk);
808 	put_device(&lnk->smcibdev->ibdev->dev);
809 	smcibdev = lnk->smcibdev;
810 	memset(lnk, 0, sizeof(struct smc_link));
811 	lnk->state = SMC_LNK_UNUSED;
812 	if (!atomic_dec_return(&smcibdev->lnk_cnt))
813 		wake_up(&smcibdev->lnks_deleted);
814 	smc_lgr_put(lgr); /* lgr_hold above */
815 	return rc;
816 }
817 
818 /* create a new SMC link group */
819 static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
820 {
821 	struct smc_link_group *lgr;
822 	struct list_head *lgr_list;
823 	struct smc_link *lnk;
824 	spinlock_t *lgr_lock;
825 	u8 link_idx;
826 	int rc = 0;
827 	int i;
828 
829 	if (ini->is_smcd && ini->vlan_id) {
830 		if (smc_ism_get_vlan(ini->ism_dev[ini->ism_selected],
831 				     ini->vlan_id)) {
832 			rc = SMC_CLC_DECL_ISMVLANERR;
833 			goto out;
834 		}
835 	}
836 
837 	lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
838 	if (!lgr) {
839 		rc = SMC_CLC_DECL_MEM;
840 		goto ism_put_vlan;
841 	}
842 	lgr->tx_wq = alloc_workqueue("smc_tx_wq-%*phN", 0, 0,
843 				     SMC_LGR_ID_SIZE, &lgr->id);
844 	if (!lgr->tx_wq) {
845 		rc = -ENOMEM;
846 		goto free_lgr;
847 	}
848 	lgr->is_smcd = ini->is_smcd;
849 	lgr->sync_err = 0;
850 	lgr->terminating = 0;
851 	lgr->freeing = 0;
852 	lgr->vlan_id = ini->vlan_id;
853 	refcount_set(&lgr->refcnt, 1); /* set lgr refcnt to 1 */
854 	mutex_init(&lgr->sndbufs_lock);
855 	mutex_init(&lgr->rmbs_lock);
856 	rwlock_init(&lgr->conns_lock);
857 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
858 		INIT_LIST_HEAD(&lgr->sndbufs[i]);
859 		INIT_LIST_HEAD(&lgr->rmbs[i]);
860 	}
861 	lgr->next_link_id = 0;
862 	smc_lgr_list.num += SMC_LGR_NUM_INCR;
863 	memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
864 	INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
865 	INIT_WORK(&lgr->terminate_work, smc_lgr_terminate_work);
866 	lgr->conns_all = RB_ROOT;
867 	if (ini->is_smcd) {
868 		/* SMC-D specific settings */
869 		get_device(&ini->ism_dev[ini->ism_selected]->dev);
870 		lgr->peer_gid = ini->ism_peer_gid[ini->ism_selected];
871 		lgr->smcd = ini->ism_dev[ini->ism_selected];
872 		lgr_list = &ini->ism_dev[ini->ism_selected]->lgr_list;
873 		lgr_lock = &lgr->smcd->lgr_lock;
874 		lgr->smc_version = ini->smcd_version;
875 		lgr->peer_shutdown = 0;
876 		atomic_inc(&ini->ism_dev[ini->ism_selected]->lgr_cnt);
877 	} else {
878 		/* SMC-R specific settings */
879 		struct smc_ib_device *ibdev;
880 		int ibport;
881 
882 		lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
883 		lgr->smc_version = ini->smcr_version;
884 		memcpy(lgr->peer_systemid, ini->peer_systemid,
885 		       SMC_SYSTEMID_LEN);
886 		if (lgr->smc_version == SMC_V2) {
887 			ibdev = ini->smcrv2.ib_dev_v2;
888 			ibport = ini->smcrv2.ib_port_v2;
889 			lgr->saddr = ini->smcrv2.saddr;
890 			lgr->uses_gateway = ini->smcrv2.uses_gateway;
891 			memcpy(lgr->nexthop_mac, ini->smcrv2.nexthop_mac,
892 			       ETH_ALEN);
893 		} else {
894 			ibdev = ini->ib_dev;
895 			ibport = ini->ib_port;
896 		}
897 		memcpy(lgr->pnet_id, ibdev->pnetid[ibport - 1],
898 		       SMC_MAX_PNETID_LEN);
899 		rc = smc_wr_alloc_lgr_mem(lgr);
900 		if (rc)
901 			goto free_wq;
902 		smc_llc_lgr_init(lgr, smc);
903 
904 		link_idx = SMC_SINGLE_LINK;
905 		lnk = &lgr->lnk[link_idx];
906 		rc = smcr_link_init(lgr, lnk, link_idx, ini);
907 		if (rc) {
908 			smc_wr_free_lgr_mem(lgr);
909 			goto free_wq;
910 		}
911 		lgr->net = smc_ib_net(lnk->smcibdev);
912 		lgr_list = &smc_lgr_list.list;
913 		lgr_lock = &smc_lgr_list.lock;
914 		lgr->buf_type = lgr->net->smc.sysctl_smcr_buf_type;
915 		atomic_inc(&lgr_cnt);
916 	}
917 	smc->conn.lgr = lgr;
918 	spin_lock_bh(lgr_lock);
919 	list_add_tail(&lgr->list, lgr_list);
920 	spin_unlock_bh(lgr_lock);
921 	return 0;
922 
923 free_wq:
924 	destroy_workqueue(lgr->tx_wq);
925 free_lgr:
926 	kfree(lgr);
927 ism_put_vlan:
928 	if (ini->is_smcd && ini->vlan_id)
929 		smc_ism_put_vlan(ini->ism_dev[ini->ism_selected], ini->vlan_id);
930 out:
931 	if (rc < 0) {
932 		if (rc == -ENOMEM)
933 			rc = SMC_CLC_DECL_MEM;
934 		else
935 			rc = SMC_CLC_DECL_INTERR;
936 	}
937 	return rc;
938 }
939 
940 static int smc_write_space(struct smc_connection *conn)
941 {
942 	int buffer_len = conn->peer_rmbe_size;
943 	union smc_host_cursor prod;
944 	union smc_host_cursor cons;
945 	int space;
946 
947 	smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
948 	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
949 	/* determine rx_buf space */
950 	space = buffer_len - smc_curs_diff(buffer_len, &cons, &prod);
951 	return space;
952 }
953 
954 static int smc_switch_cursor(struct smc_sock *smc, struct smc_cdc_tx_pend *pend,
955 			     struct smc_wr_buf *wr_buf)
956 {
957 	struct smc_connection *conn = &smc->conn;
958 	union smc_host_cursor cons, fin;
959 	int rc = 0;
960 	int diff;
961 
962 	smc_curs_copy(&conn->tx_curs_sent, &conn->tx_curs_fin, conn);
963 	smc_curs_copy(&fin, &conn->local_tx_ctrl_fin, conn);
964 	/* set prod cursor to old state, enforce tx_rdma_writes() */
965 	smc_curs_copy(&conn->local_tx_ctrl.prod, &fin, conn);
966 	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
967 
968 	if (smc_curs_comp(conn->peer_rmbe_size, &cons, &fin) < 0) {
969 		/* cons cursor advanced more than fin, and prod was set
970 		 * fin above, so now prod is smaller than cons. Fix that.
971 		 */
972 		diff = smc_curs_diff(conn->peer_rmbe_size, &fin, &cons);
973 		smc_curs_add(conn->sndbuf_desc->len,
974 			     &conn->tx_curs_sent, diff);
975 		smc_curs_add(conn->sndbuf_desc->len,
976 			     &conn->tx_curs_fin, diff);
977 
978 		smp_mb__before_atomic();
979 		atomic_add(diff, &conn->sndbuf_space);
980 		smp_mb__after_atomic();
981 
982 		smc_curs_add(conn->peer_rmbe_size,
983 			     &conn->local_tx_ctrl.prod, diff);
984 		smc_curs_add(conn->peer_rmbe_size,
985 			     &conn->local_tx_ctrl_fin, diff);
986 	}
987 	/* recalculate, value is used by tx_rdma_writes() */
988 	atomic_set(&smc->conn.peer_rmbe_space, smc_write_space(conn));
989 
990 	if (smc->sk.sk_state != SMC_INIT &&
991 	    smc->sk.sk_state != SMC_CLOSED) {
992 		rc = smcr_cdc_msg_send_validation(conn, pend, wr_buf);
993 		if (!rc) {
994 			queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 0);
995 			smc->sk.sk_data_ready(&smc->sk);
996 		}
997 	} else {
998 		smc_wr_tx_put_slot(conn->lnk,
999 				   (struct smc_wr_tx_pend_priv *)pend);
1000 	}
1001 	return rc;
1002 }
1003 
1004 void smc_switch_link_and_count(struct smc_connection *conn,
1005 			       struct smc_link *to_lnk)
1006 {
1007 	atomic_dec(&conn->lnk->conn_cnt);
1008 	/* link_hold in smc_conn_create() */
1009 	smcr_link_put(conn->lnk);
1010 	conn->lnk = to_lnk;
1011 	atomic_inc(&conn->lnk->conn_cnt);
1012 	/* link_put in smc_conn_free() */
1013 	smcr_link_hold(conn->lnk);
1014 }
1015 
1016 struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
1017 				  struct smc_link *from_lnk, bool is_dev_err)
1018 {
1019 	struct smc_link *to_lnk = NULL;
1020 	struct smc_cdc_tx_pend *pend;
1021 	struct smc_connection *conn;
1022 	struct smc_wr_buf *wr_buf;
1023 	struct smc_sock *smc;
1024 	struct rb_node *node;
1025 	int i, rc = 0;
1026 
1027 	/* link is inactive, wake up tx waiters */
1028 	smc_wr_wakeup_tx_wait(from_lnk);
1029 
1030 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1031 		if (!smc_link_active(&lgr->lnk[i]) || i == from_lnk->link_idx)
1032 			continue;
1033 		if (is_dev_err && from_lnk->smcibdev == lgr->lnk[i].smcibdev &&
1034 		    from_lnk->ibport == lgr->lnk[i].ibport) {
1035 			continue;
1036 		}
1037 		to_lnk = &lgr->lnk[i];
1038 		break;
1039 	}
1040 	if (!to_lnk || !smc_wr_tx_link_hold(to_lnk)) {
1041 		smc_lgr_terminate_sched(lgr);
1042 		return NULL;
1043 	}
1044 again:
1045 	read_lock_bh(&lgr->conns_lock);
1046 	for (node = rb_first(&lgr->conns_all); node; node = rb_next(node)) {
1047 		conn = rb_entry(node, struct smc_connection, alert_node);
1048 		if (conn->lnk != from_lnk)
1049 			continue;
1050 		smc = container_of(conn, struct smc_sock, conn);
1051 		/* conn->lnk not yet set in SMC_INIT state */
1052 		if (smc->sk.sk_state == SMC_INIT)
1053 			continue;
1054 		if (smc->sk.sk_state == SMC_CLOSED ||
1055 		    smc->sk.sk_state == SMC_PEERCLOSEWAIT1 ||
1056 		    smc->sk.sk_state == SMC_PEERCLOSEWAIT2 ||
1057 		    smc->sk.sk_state == SMC_APPFINCLOSEWAIT ||
1058 		    smc->sk.sk_state == SMC_APPCLOSEWAIT1 ||
1059 		    smc->sk.sk_state == SMC_APPCLOSEWAIT2 ||
1060 		    smc->sk.sk_state == SMC_PEERFINCLOSEWAIT ||
1061 		    smc->sk.sk_state == SMC_PEERABORTWAIT ||
1062 		    smc->sk.sk_state == SMC_PROCESSABORT) {
1063 			spin_lock_bh(&conn->send_lock);
1064 			smc_switch_link_and_count(conn, to_lnk);
1065 			spin_unlock_bh(&conn->send_lock);
1066 			continue;
1067 		}
1068 		sock_hold(&smc->sk);
1069 		read_unlock_bh(&lgr->conns_lock);
1070 		/* pre-fetch buffer outside of send_lock, might sleep */
1071 		rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend);
1072 		if (rc)
1073 			goto err_out;
1074 		/* avoid race with smcr_tx_sndbuf_nonempty() */
1075 		spin_lock_bh(&conn->send_lock);
1076 		smc_switch_link_and_count(conn, to_lnk);
1077 		rc = smc_switch_cursor(smc, pend, wr_buf);
1078 		spin_unlock_bh(&conn->send_lock);
1079 		sock_put(&smc->sk);
1080 		if (rc)
1081 			goto err_out;
1082 		goto again;
1083 	}
1084 	read_unlock_bh(&lgr->conns_lock);
1085 	smc_wr_tx_link_put(to_lnk);
1086 	return to_lnk;
1087 
1088 err_out:
1089 	smcr_link_down_cond_sched(to_lnk);
1090 	smc_wr_tx_link_put(to_lnk);
1091 	return NULL;
1092 }
1093 
1094 static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb,
1095 			   struct smc_link_group *lgr)
1096 {
1097 	struct mutex *lock;	/* lock buffer list */
1098 	int rc;
1099 
1100 	if (is_rmb && buf_desc->is_conf_rkey && !list_empty(&lgr->list)) {
1101 		/* unregister rmb with peer */
1102 		rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
1103 		if (!rc) {
1104 			/* protect against smc_llc_cli_rkey_exchange() */
1105 			mutex_lock(&lgr->llc_conf_mutex);
1106 			smc_llc_do_delete_rkey(lgr, buf_desc);
1107 			buf_desc->is_conf_rkey = false;
1108 			mutex_unlock(&lgr->llc_conf_mutex);
1109 			smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1110 		}
1111 	}
1112 
1113 	if (buf_desc->is_reg_err) {
1114 		/* buf registration failed, reuse not possible */
1115 		lock = is_rmb ? &lgr->rmbs_lock :
1116 				&lgr->sndbufs_lock;
1117 		mutex_lock(lock);
1118 		list_del(&buf_desc->list);
1119 		mutex_unlock(lock);
1120 
1121 		smc_buf_free(lgr, is_rmb, buf_desc);
1122 	} else {
1123 		buf_desc->used = 0;
1124 		memset(buf_desc->cpu_addr, 0, buf_desc->len);
1125 	}
1126 }
1127 
1128 static void smc_buf_unuse(struct smc_connection *conn,
1129 			  struct smc_link_group *lgr)
1130 {
1131 	if (conn->sndbuf_desc) {
1132 		if (!lgr->is_smcd && conn->sndbuf_desc->is_vm) {
1133 			smcr_buf_unuse(conn->sndbuf_desc, false, lgr);
1134 		} else {
1135 			conn->sndbuf_desc->used = 0;
1136 			memset(conn->sndbuf_desc->cpu_addr, 0,
1137 			       conn->sndbuf_desc->len);
1138 		}
1139 	}
1140 	if (conn->rmb_desc) {
1141 		if (!lgr->is_smcd) {
1142 			smcr_buf_unuse(conn->rmb_desc, true, lgr);
1143 		} else {
1144 			conn->rmb_desc->used = 0;
1145 			memset(conn->rmb_desc->cpu_addr, 0,
1146 			       conn->rmb_desc->len +
1147 			       sizeof(struct smcd_cdc_msg));
1148 		}
1149 	}
1150 }
1151 
1152 /* remove a finished connection from its link group */
1153 void smc_conn_free(struct smc_connection *conn)
1154 {
1155 	struct smc_link_group *lgr = conn->lgr;
1156 
1157 	if (!lgr || conn->freed)
1158 		/* Connection has never been registered in a
1159 		 * link group, or has already been freed.
1160 		 */
1161 		return;
1162 
1163 	conn->freed = 1;
1164 	if (!smc_conn_lgr_valid(conn))
1165 		/* Connection has already unregistered from
1166 		 * link group.
1167 		 */
1168 		goto lgr_put;
1169 
1170 	if (lgr->is_smcd) {
1171 		if (!list_empty(&lgr->list))
1172 			smc_ism_unset_conn(conn);
1173 		tasklet_kill(&conn->rx_tsklet);
1174 	} else {
1175 		smc_cdc_wait_pend_tx_wr(conn);
1176 		if (current_work() != &conn->abort_work)
1177 			cancel_work_sync(&conn->abort_work);
1178 	}
1179 	if (!list_empty(&lgr->list)) {
1180 		smc_buf_unuse(conn, lgr); /* allow buffer reuse */
1181 		smc_lgr_unregister_conn(conn);
1182 	}
1183 
1184 	if (!lgr->conns_num)
1185 		smc_lgr_schedule_free_work(lgr);
1186 lgr_put:
1187 	if (!lgr->is_smcd)
1188 		smcr_link_put(conn->lnk); /* link_hold in smc_conn_create() */
1189 	smc_lgr_put(lgr); /* lgr_hold in smc_conn_create() */
1190 }
1191 
1192 /* unregister a link from a buf_desc */
1193 static void smcr_buf_unmap_link(struct smc_buf_desc *buf_desc, bool is_rmb,
1194 				struct smc_link *lnk)
1195 {
1196 	if (is_rmb || buf_desc->is_vm)
1197 		buf_desc->is_reg_mr[lnk->link_idx] = false;
1198 	if (!buf_desc->is_map_ib[lnk->link_idx])
1199 		return;
1200 
1201 	if ((is_rmb || buf_desc->is_vm) &&
1202 	    buf_desc->mr[lnk->link_idx]) {
1203 		smc_ib_put_memory_region(buf_desc->mr[lnk->link_idx]);
1204 		buf_desc->mr[lnk->link_idx] = NULL;
1205 	}
1206 	if (is_rmb)
1207 		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_FROM_DEVICE);
1208 	else
1209 		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_TO_DEVICE);
1210 
1211 	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
1212 	buf_desc->is_map_ib[lnk->link_idx] = false;
1213 }
1214 
1215 /* unmap all buffers of lgr for a deleted link */
1216 static void smcr_buf_unmap_lgr(struct smc_link *lnk)
1217 {
1218 	struct smc_link_group *lgr = lnk->lgr;
1219 	struct smc_buf_desc *buf_desc, *bf;
1220 	int i;
1221 
1222 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1223 		mutex_lock(&lgr->rmbs_lock);
1224 		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list)
1225 			smcr_buf_unmap_link(buf_desc, true, lnk);
1226 		mutex_unlock(&lgr->rmbs_lock);
1227 		mutex_lock(&lgr->sndbufs_lock);
1228 		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i],
1229 					 list)
1230 			smcr_buf_unmap_link(buf_desc, false, lnk);
1231 		mutex_unlock(&lgr->sndbufs_lock);
1232 	}
1233 }
1234 
1235 static void smcr_rtoken_clear_link(struct smc_link *lnk)
1236 {
1237 	struct smc_link_group *lgr = lnk->lgr;
1238 	int i;
1239 
1240 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1241 		lgr->rtokens[i][lnk->link_idx].rkey = 0;
1242 		lgr->rtokens[i][lnk->link_idx].dma_addr = 0;
1243 	}
1244 }
1245 
1246 static void __smcr_link_clear(struct smc_link *lnk)
1247 {
1248 	struct smc_link_group *lgr = lnk->lgr;
1249 	struct smc_ib_device *smcibdev;
1250 
1251 	smc_wr_free_link_mem(lnk);
1252 	smc_ibdev_cnt_dec(lnk);
1253 	put_device(&lnk->smcibdev->ibdev->dev);
1254 	smcibdev = lnk->smcibdev;
1255 	memset(lnk, 0, sizeof(struct smc_link));
1256 	lnk->state = SMC_LNK_UNUSED;
1257 	if (!atomic_dec_return(&smcibdev->lnk_cnt))
1258 		wake_up(&smcibdev->lnks_deleted);
1259 	smc_lgr_put(lgr); /* lgr_hold in smcr_link_init() */
1260 }
1261 
1262 /* must be called under lgr->llc_conf_mutex lock */
1263 void smcr_link_clear(struct smc_link *lnk, bool log)
1264 {
1265 	if (!lnk->lgr || lnk->clearing ||
1266 	    lnk->state == SMC_LNK_UNUSED)
1267 		return;
1268 	lnk->clearing = 1;
1269 	lnk->peer_qpn = 0;
1270 	smc_llc_link_clear(lnk, log);
1271 	smcr_buf_unmap_lgr(lnk);
1272 	smcr_rtoken_clear_link(lnk);
1273 	smc_ib_modify_qp_error(lnk);
1274 	smc_wr_free_link(lnk);
1275 	smc_ib_destroy_queue_pair(lnk);
1276 	smc_ib_dealloc_protection_domain(lnk);
1277 	smcr_link_put(lnk); /* theoretically last link_put */
1278 }
1279 
1280 void smcr_link_hold(struct smc_link *lnk)
1281 {
1282 	refcount_inc(&lnk->refcnt);
1283 }
1284 
1285 void smcr_link_put(struct smc_link *lnk)
1286 {
1287 	if (refcount_dec_and_test(&lnk->refcnt))
1288 		__smcr_link_clear(lnk);
1289 }
1290 
1291 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
1292 			  struct smc_buf_desc *buf_desc)
1293 {
1294 	int i;
1295 
1296 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1297 		smcr_buf_unmap_link(buf_desc, is_rmb, &lgr->lnk[i]);
1298 
1299 	if (!buf_desc->is_vm && buf_desc->pages)
1300 		__free_pages(buf_desc->pages, buf_desc->order);
1301 	else if (buf_desc->is_vm && buf_desc->cpu_addr)
1302 		vfree(buf_desc->cpu_addr);
1303 	kfree(buf_desc);
1304 }
1305 
1306 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
1307 			  struct smc_buf_desc *buf_desc)
1308 {
1309 	if (is_dmb) {
1310 		/* restore original buf len */
1311 		buf_desc->len += sizeof(struct smcd_cdc_msg);
1312 		smc_ism_unregister_dmb(lgr->smcd, buf_desc);
1313 	} else {
1314 		kfree(buf_desc->cpu_addr);
1315 	}
1316 	kfree(buf_desc);
1317 }
1318 
1319 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
1320 			 struct smc_buf_desc *buf_desc)
1321 {
1322 	if (lgr->is_smcd)
1323 		smcd_buf_free(lgr, is_rmb, buf_desc);
1324 	else
1325 		smcr_buf_free(lgr, is_rmb, buf_desc);
1326 }
1327 
1328 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
1329 {
1330 	struct smc_buf_desc *buf_desc, *bf_desc;
1331 	struct list_head *buf_list;
1332 	int i;
1333 
1334 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1335 		if (is_rmb)
1336 			buf_list = &lgr->rmbs[i];
1337 		else
1338 			buf_list = &lgr->sndbufs[i];
1339 		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
1340 					 list) {
1341 			list_del(&buf_desc->list);
1342 			smc_buf_free(lgr, is_rmb, buf_desc);
1343 		}
1344 	}
1345 }
1346 
1347 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
1348 {
1349 	/* free send buffers */
1350 	__smc_lgr_free_bufs(lgr, false);
1351 	/* free rmbs */
1352 	__smc_lgr_free_bufs(lgr, true);
1353 }
1354 
1355 /* won't be freed until no one accesses to lgr anymore */
1356 static void __smc_lgr_free(struct smc_link_group *lgr)
1357 {
1358 	smc_lgr_free_bufs(lgr);
1359 	if (lgr->is_smcd) {
1360 		if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
1361 			wake_up(&lgr->smcd->lgrs_deleted);
1362 	} else {
1363 		smc_wr_free_lgr_mem(lgr);
1364 		if (!atomic_dec_return(&lgr_cnt))
1365 			wake_up(&lgrs_deleted);
1366 	}
1367 	kfree(lgr);
1368 }
1369 
1370 /* remove a link group */
1371 static void smc_lgr_free(struct smc_link_group *lgr)
1372 {
1373 	int i;
1374 
1375 	if (!lgr->is_smcd) {
1376 		mutex_lock(&lgr->llc_conf_mutex);
1377 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1378 			if (lgr->lnk[i].state != SMC_LNK_UNUSED)
1379 				smcr_link_clear(&lgr->lnk[i], false);
1380 		}
1381 		mutex_unlock(&lgr->llc_conf_mutex);
1382 		smc_llc_lgr_clear(lgr);
1383 	}
1384 
1385 	destroy_workqueue(lgr->tx_wq);
1386 	if (lgr->is_smcd) {
1387 		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
1388 		put_device(&lgr->smcd->dev);
1389 	}
1390 	smc_lgr_put(lgr); /* theoretically last lgr_put */
1391 }
1392 
1393 void smc_lgr_hold(struct smc_link_group *lgr)
1394 {
1395 	refcount_inc(&lgr->refcnt);
1396 }
1397 
1398 void smc_lgr_put(struct smc_link_group *lgr)
1399 {
1400 	if (refcount_dec_and_test(&lgr->refcnt))
1401 		__smc_lgr_free(lgr);
1402 }
1403 
1404 static void smc_sk_wake_ups(struct smc_sock *smc)
1405 {
1406 	smc->sk.sk_write_space(&smc->sk);
1407 	smc->sk.sk_data_ready(&smc->sk);
1408 	smc->sk.sk_state_change(&smc->sk);
1409 }
1410 
1411 /* kill a connection */
1412 static void smc_conn_kill(struct smc_connection *conn, bool soft)
1413 {
1414 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1415 
1416 	if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
1417 		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
1418 	else
1419 		smc_close_abort(conn);
1420 	conn->killed = 1;
1421 	smc->sk.sk_err = ECONNABORTED;
1422 	smc_sk_wake_ups(smc);
1423 	if (conn->lgr->is_smcd) {
1424 		smc_ism_unset_conn(conn);
1425 		if (soft)
1426 			tasklet_kill(&conn->rx_tsklet);
1427 		else
1428 			tasklet_unlock_wait(&conn->rx_tsklet);
1429 	} else {
1430 		smc_cdc_wait_pend_tx_wr(conn);
1431 	}
1432 	smc_lgr_unregister_conn(conn);
1433 	smc_close_active_abort(smc);
1434 }
1435 
1436 static void smc_lgr_cleanup(struct smc_link_group *lgr)
1437 {
1438 	if (lgr->is_smcd) {
1439 		smc_ism_signal_shutdown(lgr);
1440 	} else {
1441 		u32 rsn = lgr->llc_termination_rsn;
1442 
1443 		if (!rsn)
1444 			rsn = SMC_LLC_DEL_PROG_INIT_TERM;
1445 		smc_llc_send_link_delete_all(lgr, false, rsn);
1446 		smcr_lgr_link_deactivate_all(lgr);
1447 	}
1448 }
1449 
1450 /* terminate link group
1451  * @soft: true if link group shutdown can take its time
1452  *	  false if immediate link group shutdown is required
1453  */
1454 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
1455 {
1456 	struct smc_connection *conn;
1457 	struct smc_sock *smc;
1458 	struct rb_node *node;
1459 
1460 	if (lgr->terminating)
1461 		return;	/* lgr already terminating */
1462 	/* cancel free_work sync, will terminate when lgr->freeing is set */
1463 	cancel_delayed_work_sync(&lgr->free_work);
1464 	lgr->terminating = 1;
1465 
1466 	/* kill remaining link group connections */
1467 	read_lock_bh(&lgr->conns_lock);
1468 	node = rb_first(&lgr->conns_all);
1469 	while (node) {
1470 		read_unlock_bh(&lgr->conns_lock);
1471 		conn = rb_entry(node, struct smc_connection, alert_node);
1472 		smc = container_of(conn, struct smc_sock, conn);
1473 		sock_hold(&smc->sk); /* sock_put below */
1474 		lock_sock(&smc->sk);
1475 		smc_conn_kill(conn, soft);
1476 		release_sock(&smc->sk);
1477 		sock_put(&smc->sk); /* sock_hold above */
1478 		read_lock_bh(&lgr->conns_lock);
1479 		node = rb_first(&lgr->conns_all);
1480 	}
1481 	read_unlock_bh(&lgr->conns_lock);
1482 	smc_lgr_cleanup(lgr);
1483 	smc_lgr_free(lgr);
1484 }
1485 
1486 /* unlink link group and schedule termination */
1487 void smc_lgr_terminate_sched(struct smc_link_group *lgr)
1488 {
1489 	spinlock_t *lgr_lock;
1490 
1491 	smc_lgr_list_head(lgr, &lgr_lock);
1492 	spin_lock_bh(lgr_lock);
1493 	if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
1494 		spin_unlock_bh(lgr_lock);
1495 		return;	/* lgr already terminating */
1496 	}
1497 	list_del_init(&lgr->list);
1498 	lgr->freeing = 1;
1499 	spin_unlock_bh(lgr_lock);
1500 	schedule_work(&lgr->terminate_work);
1501 }
1502 
1503 /* Called when peer lgr shutdown (regularly or abnormally) is received */
1504 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
1505 {
1506 	struct smc_link_group *lgr, *l;
1507 	LIST_HEAD(lgr_free_list);
1508 
1509 	/* run common cleanup function and build free list */
1510 	spin_lock_bh(&dev->lgr_lock);
1511 	list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
1512 		if ((!peer_gid || lgr->peer_gid == peer_gid) &&
1513 		    (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
1514 			if (peer_gid) /* peer triggered termination */
1515 				lgr->peer_shutdown = 1;
1516 			list_move(&lgr->list, &lgr_free_list);
1517 			lgr->freeing = 1;
1518 		}
1519 	}
1520 	spin_unlock_bh(&dev->lgr_lock);
1521 
1522 	/* cancel the regular free workers and actually free lgrs */
1523 	list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
1524 		list_del_init(&lgr->list);
1525 		schedule_work(&lgr->terminate_work);
1526 	}
1527 }
1528 
1529 /* Called when an SMCD device is removed or the smc module is unloaded */
1530 void smc_smcd_terminate_all(struct smcd_dev *smcd)
1531 {
1532 	struct smc_link_group *lgr, *lg;
1533 	LIST_HEAD(lgr_free_list);
1534 
1535 	spin_lock_bh(&smcd->lgr_lock);
1536 	list_splice_init(&smcd->lgr_list, &lgr_free_list);
1537 	list_for_each_entry(lgr, &lgr_free_list, list)
1538 		lgr->freeing = 1;
1539 	spin_unlock_bh(&smcd->lgr_lock);
1540 
1541 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1542 		list_del_init(&lgr->list);
1543 		__smc_lgr_terminate(lgr, false);
1544 	}
1545 
1546 	if (atomic_read(&smcd->lgr_cnt))
1547 		wait_event(smcd->lgrs_deleted, !atomic_read(&smcd->lgr_cnt));
1548 }
1549 
1550 /* Called when an SMCR device is removed or the smc module is unloaded.
1551  * If smcibdev is given, all SMCR link groups using this device are terminated.
1552  * If smcibdev is NULL, all SMCR link groups are terminated.
1553  */
1554 void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
1555 {
1556 	struct smc_link_group *lgr, *lg;
1557 	LIST_HEAD(lgr_free_list);
1558 	int i;
1559 
1560 	spin_lock_bh(&smc_lgr_list.lock);
1561 	if (!smcibdev) {
1562 		list_splice_init(&smc_lgr_list.list, &lgr_free_list);
1563 		list_for_each_entry(lgr, &lgr_free_list, list)
1564 			lgr->freeing = 1;
1565 	} else {
1566 		list_for_each_entry_safe(lgr, lg, &smc_lgr_list.list, list) {
1567 			for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1568 				if (lgr->lnk[i].smcibdev == smcibdev)
1569 					smcr_link_down_cond_sched(&lgr->lnk[i]);
1570 			}
1571 		}
1572 	}
1573 	spin_unlock_bh(&smc_lgr_list.lock);
1574 
1575 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1576 		list_del_init(&lgr->list);
1577 		smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_OP_INIT_TERM);
1578 		__smc_lgr_terminate(lgr, false);
1579 	}
1580 
1581 	if (smcibdev) {
1582 		if (atomic_read(&smcibdev->lnk_cnt))
1583 			wait_event(smcibdev->lnks_deleted,
1584 				   !atomic_read(&smcibdev->lnk_cnt));
1585 	} else {
1586 		if (atomic_read(&lgr_cnt))
1587 			wait_event(lgrs_deleted, !atomic_read(&lgr_cnt));
1588 	}
1589 }
1590 
1591 /* set new lgr type and clear all asymmetric link tagging */
1592 void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type)
1593 {
1594 	char *lgr_type = "";
1595 	int i;
1596 
1597 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1598 		if (smc_link_usable(&lgr->lnk[i]))
1599 			lgr->lnk[i].link_is_asym = false;
1600 	if (lgr->type == new_type)
1601 		return;
1602 	lgr->type = new_type;
1603 
1604 	switch (lgr->type) {
1605 	case SMC_LGR_NONE:
1606 		lgr_type = "NONE";
1607 		break;
1608 	case SMC_LGR_SINGLE:
1609 		lgr_type = "SINGLE";
1610 		break;
1611 	case SMC_LGR_SYMMETRIC:
1612 		lgr_type = "SYMMETRIC";
1613 		break;
1614 	case SMC_LGR_ASYMMETRIC_PEER:
1615 		lgr_type = "ASYMMETRIC_PEER";
1616 		break;
1617 	case SMC_LGR_ASYMMETRIC_LOCAL:
1618 		lgr_type = "ASYMMETRIC_LOCAL";
1619 		break;
1620 	}
1621 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu state changed: "
1622 			    "%s, pnetid %.16s\n", SMC_LGR_ID_SIZE, &lgr->id,
1623 			    lgr->net->net_cookie, lgr_type, lgr->pnet_id);
1624 }
1625 
1626 /* set new lgr type and tag a link as asymmetric */
1627 void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
1628 			    enum smc_lgr_type new_type, int asym_lnk_idx)
1629 {
1630 	smcr_lgr_set_type(lgr, new_type);
1631 	lgr->lnk[asym_lnk_idx].link_is_asym = true;
1632 }
1633 
1634 /* abort connection, abort_work scheduled from tasklet context */
1635 static void smc_conn_abort_work(struct work_struct *work)
1636 {
1637 	struct smc_connection *conn = container_of(work,
1638 						   struct smc_connection,
1639 						   abort_work);
1640 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1641 
1642 	lock_sock(&smc->sk);
1643 	smc_conn_kill(conn, true);
1644 	release_sock(&smc->sk);
1645 	sock_put(&smc->sk); /* sock_hold done by schedulers of abort_work */
1646 }
1647 
1648 void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
1649 {
1650 	struct smc_link_group *lgr, *n;
1651 
1652 	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1653 		struct smc_link *link;
1654 
1655 		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1656 			    SMC_MAX_PNETID_LEN) ||
1657 		    lgr->type == SMC_LGR_SYMMETRIC ||
1658 		    lgr->type == SMC_LGR_ASYMMETRIC_PEER ||
1659 		    !rdma_dev_access_netns(smcibdev->ibdev, lgr->net))
1660 			continue;
1661 
1662 		/* trigger local add link processing */
1663 		link = smc_llc_usable_link(lgr);
1664 		if (link)
1665 			smc_llc_add_link_local(link);
1666 	}
1667 }
1668 
1669 /* link is down - switch connections to alternate link,
1670  * must be called under lgr->llc_conf_mutex lock
1671  */
1672 static void smcr_link_down(struct smc_link *lnk)
1673 {
1674 	struct smc_link_group *lgr = lnk->lgr;
1675 	struct smc_link *to_lnk;
1676 	int del_link_id;
1677 
1678 	if (!lgr || lnk->state == SMC_LNK_UNUSED || list_empty(&lgr->list))
1679 		return;
1680 
1681 	to_lnk = smc_switch_conns(lgr, lnk, true);
1682 	if (!to_lnk) { /* no backup link available */
1683 		smcr_link_clear(lnk, true);
1684 		return;
1685 	}
1686 	smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1687 	del_link_id = lnk->link_id;
1688 
1689 	if (lgr->role == SMC_SERV) {
1690 		/* trigger local delete link processing */
1691 		smc_llc_srv_delete_link_local(to_lnk, del_link_id);
1692 	} else {
1693 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1694 			/* another llc task is ongoing */
1695 			mutex_unlock(&lgr->llc_conf_mutex);
1696 			wait_event_timeout(lgr->llc_flow_waiter,
1697 				(list_empty(&lgr->list) ||
1698 				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
1699 				SMC_LLC_WAIT_TIME);
1700 			mutex_lock(&lgr->llc_conf_mutex);
1701 		}
1702 		if (!list_empty(&lgr->list)) {
1703 			smc_llc_send_delete_link(to_lnk, del_link_id,
1704 						 SMC_LLC_REQ, true,
1705 						 SMC_LLC_DEL_LOST_PATH);
1706 			smcr_link_clear(lnk, true);
1707 		}
1708 		wake_up(&lgr->llc_flow_waiter);	/* wake up next waiter */
1709 	}
1710 }
1711 
1712 /* must be called under lgr->llc_conf_mutex lock */
1713 void smcr_link_down_cond(struct smc_link *lnk)
1714 {
1715 	if (smc_link_downing(&lnk->state)) {
1716 		trace_smcr_link_down(lnk, __builtin_return_address(0));
1717 		smcr_link_down(lnk);
1718 	}
1719 }
1720 
1721 /* will get the lgr->llc_conf_mutex lock */
1722 void smcr_link_down_cond_sched(struct smc_link *lnk)
1723 {
1724 	if (smc_link_downing(&lnk->state)) {
1725 		trace_smcr_link_down(lnk, __builtin_return_address(0));
1726 		schedule_work(&lnk->link_down_wrk);
1727 	}
1728 }
1729 
1730 void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport)
1731 {
1732 	struct smc_link_group *lgr, *n;
1733 	int i;
1734 
1735 	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1736 		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1737 			    SMC_MAX_PNETID_LEN))
1738 			continue; /* lgr is not affected */
1739 		if (list_empty(&lgr->list))
1740 			continue;
1741 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1742 			struct smc_link *lnk = &lgr->lnk[i];
1743 
1744 			if (smc_link_usable(lnk) &&
1745 			    lnk->smcibdev == smcibdev && lnk->ibport == ibport)
1746 				smcr_link_down_cond_sched(lnk);
1747 		}
1748 	}
1749 }
1750 
1751 static void smc_link_down_work(struct work_struct *work)
1752 {
1753 	struct smc_link *link = container_of(work, struct smc_link,
1754 					     link_down_wrk);
1755 	struct smc_link_group *lgr = link->lgr;
1756 
1757 	if (list_empty(&lgr->list))
1758 		return;
1759 	wake_up_all(&lgr->llc_msg_waiter);
1760 	mutex_lock(&lgr->llc_conf_mutex);
1761 	smcr_link_down(link);
1762 	mutex_unlock(&lgr->llc_conf_mutex);
1763 }
1764 
1765 static int smc_vlan_by_tcpsk_walk(struct net_device *lower_dev,
1766 				  struct netdev_nested_priv *priv)
1767 {
1768 	unsigned short *vlan_id = (unsigned short *)priv->data;
1769 
1770 	if (is_vlan_dev(lower_dev)) {
1771 		*vlan_id = vlan_dev_vlan_id(lower_dev);
1772 		return 1;
1773 	}
1774 
1775 	return 0;
1776 }
1777 
1778 /* Determine vlan of internal TCP socket. */
1779 int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
1780 {
1781 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
1782 	struct netdev_nested_priv priv;
1783 	struct net_device *ndev;
1784 	int rc = 0;
1785 
1786 	ini->vlan_id = 0;
1787 	if (!dst) {
1788 		rc = -ENOTCONN;
1789 		goto out;
1790 	}
1791 	if (!dst->dev) {
1792 		rc = -ENODEV;
1793 		goto out_rel;
1794 	}
1795 
1796 	ndev = dst->dev;
1797 	if (is_vlan_dev(ndev)) {
1798 		ini->vlan_id = vlan_dev_vlan_id(ndev);
1799 		goto out_rel;
1800 	}
1801 
1802 	priv.data = (void *)&ini->vlan_id;
1803 	rtnl_lock();
1804 	netdev_walk_all_lower_dev(ndev, smc_vlan_by_tcpsk_walk, &priv);
1805 	rtnl_unlock();
1806 
1807 out_rel:
1808 	dst_release(dst);
1809 out:
1810 	return rc;
1811 }
1812 
1813 static bool smcr_lgr_match(struct smc_link_group *lgr, u8 smcr_version,
1814 			   u8 peer_systemid[],
1815 			   u8 peer_gid[],
1816 			   u8 peer_mac_v1[],
1817 			   enum smc_lgr_role role, u32 clcqpn,
1818 			   struct net *net)
1819 {
1820 	struct smc_link *lnk;
1821 	int i;
1822 
1823 	if (memcmp(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN) ||
1824 	    lgr->role != role)
1825 		return false;
1826 
1827 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1828 		lnk = &lgr->lnk[i];
1829 
1830 		if (!smc_link_active(lnk))
1831 			continue;
1832 		/* use verbs API to check netns, instead of lgr->net */
1833 		if (!rdma_dev_access_netns(lnk->smcibdev->ibdev, net))
1834 			return false;
1835 		if ((lgr->role == SMC_SERV || lnk->peer_qpn == clcqpn) &&
1836 		    !memcmp(lnk->peer_gid, peer_gid, SMC_GID_SIZE) &&
1837 		    (smcr_version == SMC_V2 ||
1838 		     !memcmp(lnk->peer_mac, peer_mac_v1, ETH_ALEN)))
1839 			return true;
1840 	}
1841 	return false;
1842 }
1843 
1844 static bool smcd_lgr_match(struct smc_link_group *lgr,
1845 			   struct smcd_dev *smcismdev, u64 peer_gid)
1846 {
1847 	return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
1848 }
1849 
1850 /* create a new SMC connection (and a new link group if necessary) */
1851 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
1852 {
1853 	struct smc_connection *conn = &smc->conn;
1854 	struct net *net = sock_net(&smc->sk);
1855 	struct list_head *lgr_list;
1856 	struct smc_link_group *lgr;
1857 	enum smc_lgr_role role;
1858 	spinlock_t *lgr_lock;
1859 	int rc = 0;
1860 
1861 	lgr_list = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_list :
1862 				  &smc_lgr_list.list;
1863 	lgr_lock = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_lock :
1864 				  &smc_lgr_list.lock;
1865 	ini->first_contact_local = 1;
1866 	role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
1867 	if (role == SMC_CLNT && ini->first_contact_peer)
1868 		/* create new link group as well */
1869 		goto create;
1870 
1871 	/* determine if an existing link group can be reused */
1872 	spin_lock_bh(lgr_lock);
1873 	list_for_each_entry(lgr, lgr_list, list) {
1874 		write_lock_bh(&lgr->conns_lock);
1875 		if ((ini->is_smcd ?
1876 		     smcd_lgr_match(lgr, ini->ism_dev[ini->ism_selected],
1877 				    ini->ism_peer_gid[ini->ism_selected]) :
1878 		     smcr_lgr_match(lgr, ini->smcr_version,
1879 				    ini->peer_systemid,
1880 				    ini->peer_gid, ini->peer_mac, role,
1881 				    ini->ib_clcqpn, net)) &&
1882 		    !lgr->sync_err &&
1883 		    (ini->smcd_version == SMC_V2 ||
1884 		     lgr->vlan_id == ini->vlan_id) &&
1885 		    (role == SMC_CLNT || ini->is_smcd ||
1886 		    (lgr->conns_num < SMC_RMBS_PER_LGR_MAX &&
1887 		      !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) {
1888 			/* link group found */
1889 			ini->first_contact_local = 0;
1890 			conn->lgr = lgr;
1891 			rc = smc_lgr_register_conn(conn, false);
1892 			write_unlock_bh(&lgr->conns_lock);
1893 			if (!rc && delayed_work_pending(&lgr->free_work))
1894 				cancel_delayed_work(&lgr->free_work);
1895 			break;
1896 		}
1897 		write_unlock_bh(&lgr->conns_lock);
1898 	}
1899 	spin_unlock_bh(lgr_lock);
1900 	if (rc)
1901 		return rc;
1902 
1903 	if (role == SMC_CLNT && !ini->first_contact_peer &&
1904 	    ini->first_contact_local) {
1905 		/* Server reuses a link group, but Client wants to start
1906 		 * a new one
1907 		 * send out_of_sync decline, reason synchr. error
1908 		 */
1909 		return SMC_CLC_DECL_SYNCERR;
1910 	}
1911 
1912 create:
1913 	if (ini->first_contact_local) {
1914 		rc = smc_lgr_create(smc, ini);
1915 		if (rc)
1916 			goto out;
1917 		lgr = conn->lgr;
1918 		write_lock_bh(&lgr->conns_lock);
1919 		rc = smc_lgr_register_conn(conn, true);
1920 		write_unlock_bh(&lgr->conns_lock);
1921 		if (rc) {
1922 			smc_lgr_cleanup_early(lgr);
1923 			goto out;
1924 		}
1925 	}
1926 	smc_lgr_hold(conn->lgr); /* lgr_put in smc_conn_free() */
1927 	if (!conn->lgr->is_smcd)
1928 		smcr_link_hold(conn->lnk); /* link_put in smc_conn_free() */
1929 	conn->freed = 0;
1930 	conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
1931 	conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
1932 	conn->urg_state = SMC_URG_READ;
1933 	init_waitqueue_head(&conn->cdc_pend_tx_wq);
1934 	INIT_WORK(&smc->conn.abort_work, smc_conn_abort_work);
1935 	if (ini->is_smcd) {
1936 		conn->rx_off = sizeof(struct smcd_cdc_msg);
1937 		smcd_cdc_rx_init(conn); /* init tasklet for this conn */
1938 	} else {
1939 		conn->rx_off = 0;
1940 	}
1941 #ifndef KERNEL_HAS_ATOMIC64
1942 	spin_lock_init(&conn->acurs_lock);
1943 #endif
1944 
1945 out:
1946 	return rc;
1947 }
1948 
1949 #define SMCD_DMBE_SIZES		6 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
1950 #define SMCR_RMBE_SIZES		5 /* 0 -> 16KB, 1 -> 32KB, .. 5 -> 512KB */
1951 
1952 /* convert the RMB size into the compressed notation (minimum 16K, see
1953  * SMCD/R_DMBE_SIZES.
1954  * In contrast to plain ilog2, this rounds towards the next power of 2,
1955  * so the socket application gets at least its desired sndbuf / rcvbuf size.
1956  */
1957 static u8 smc_compress_bufsize(int size, bool is_smcd, bool is_rmb)
1958 {
1959 	const unsigned int max_scat = SG_MAX_SINGLE_ALLOC * PAGE_SIZE;
1960 	u8 compressed;
1961 
1962 	if (size <= SMC_BUF_MIN_SIZE)
1963 		return 0;
1964 
1965 	size = (size - 1) >> 14;  /* convert to 16K multiple */
1966 	compressed = min_t(u8, ilog2(size) + 1,
1967 			   is_smcd ? SMCD_DMBE_SIZES : SMCR_RMBE_SIZES);
1968 
1969 	if (!is_smcd && is_rmb)
1970 		/* RMBs are backed by & limited to max size of scatterlists */
1971 		compressed = min_t(u8, compressed, ilog2(max_scat >> 14));
1972 
1973 	return compressed;
1974 }
1975 
1976 /* convert the RMB size from compressed notation into integer */
1977 int smc_uncompress_bufsize(u8 compressed)
1978 {
1979 	u32 size;
1980 
1981 	size = 0x00000001 << (((int)compressed) + 14);
1982 	return (int)size;
1983 }
1984 
1985 /* try to reuse a sndbuf or rmb description slot for a certain
1986  * buffer size; if not available, return NULL
1987  */
1988 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
1989 					     struct mutex *lock,
1990 					     struct list_head *buf_list)
1991 {
1992 	struct smc_buf_desc *buf_slot;
1993 
1994 	mutex_lock(lock);
1995 	list_for_each_entry(buf_slot, buf_list, list) {
1996 		if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
1997 			mutex_unlock(lock);
1998 			return buf_slot;
1999 		}
2000 	}
2001 	mutex_unlock(lock);
2002 	return NULL;
2003 }
2004 
2005 /* one of the conditions for announcing a receiver's current window size is
2006  * that it "results in a minimum increase in the window size of 10% of the
2007  * receive buffer space" [RFC7609]
2008  */
2009 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
2010 {
2011 	return max_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
2012 }
2013 
2014 /* map an buf to a link */
2015 static int smcr_buf_map_link(struct smc_buf_desc *buf_desc, bool is_rmb,
2016 			     struct smc_link *lnk)
2017 {
2018 	int rc, i, nents, offset, buf_size, size, access_flags;
2019 	struct scatterlist *sg;
2020 	void *buf;
2021 
2022 	if (buf_desc->is_map_ib[lnk->link_idx])
2023 		return 0;
2024 
2025 	if (buf_desc->is_vm) {
2026 		buf = buf_desc->cpu_addr;
2027 		buf_size = buf_desc->len;
2028 		offset = offset_in_page(buf_desc->cpu_addr);
2029 		nents = PAGE_ALIGN(buf_size + offset) / PAGE_SIZE;
2030 	} else {
2031 		nents = 1;
2032 	}
2033 
2034 	rc = sg_alloc_table(&buf_desc->sgt[lnk->link_idx], nents, GFP_KERNEL);
2035 	if (rc)
2036 		return rc;
2037 
2038 	if (buf_desc->is_vm) {
2039 		/* virtually contiguous buffer */
2040 		for_each_sg(buf_desc->sgt[lnk->link_idx].sgl, sg, nents, i) {
2041 			size = min_t(int, PAGE_SIZE - offset, buf_size);
2042 			sg_set_page(sg, vmalloc_to_page(buf), size, offset);
2043 			buf += size / sizeof(*buf);
2044 			buf_size -= size;
2045 			offset = 0;
2046 		}
2047 	} else {
2048 		/* physically contiguous buffer */
2049 		sg_set_buf(buf_desc->sgt[lnk->link_idx].sgl,
2050 			   buf_desc->cpu_addr, buf_desc->len);
2051 	}
2052 
2053 	/* map sg table to DMA address */
2054 	rc = smc_ib_buf_map_sg(lnk, buf_desc,
2055 			       is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2056 	/* SMC protocol depends on mapping to one DMA address only */
2057 	if (rc != nents) {
2058 		rc = -EAGAIN;
2059 		goto free_table;
2060 	}
2061 
2062 	buf_desc->is_dma_need_sync |=
2063 		smc_ib_is_sg_need_sync(lnk, buf_desc) << lnk->link_idx;
2064 
2065 	if (is_rmb || buf_desc->is_vm) {
2066 		/* create a new memory region for the RMB or vzalloced sndbuf */
2067 		access_flags = is_rmb ?
2068 			       IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
2069 			       IB_ACCESS_LOCAL_WRITE;
2070 
2071 		rc = smc_ib_get_memory_region(lnk->roce_pd, access_flags,
2072 					      buf_desc, lnk->link_idx);
2073 		if (rc)
2074 			goto buf_unmap;
2075 		smc_ib_sync_sg_for_device(lnk, buf_desc,
2076 					  is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2077 	}
2078 	buf_desc->is_map_ib[lnk->link_idx] = true;
2079 	return 0;
2080 
2081 buf_unmap:
2082 	smc_ib_buf_unmap_sg(lnk, buf_desc,
2083 			    is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2084 free_table:
2085 	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
2086 	return rc;
2087 }
2088 
2089 /* register a new buf on IB device, rmb or vzalloced sndbuf
2090  * must be called under lgr->llc_conf_mutex lock
2091  */
2092 int smcr_link_reg_buf(struct smc_link *link, struct smc_buf_desc *buf_desc)
2093 {
2094 	if (list_empty(&link->lgr->list))
2095 		return -ENOLINK;
2096 	if (!buf_desc->is_reg_mr[link->link_idx]) {
2097 		/* register memory region for new buf */
2098 		if (buf_desc->is_vm)
2099 			buf_desc->mr[link->link_idx]->iova =
2100 				(uintptr_t)buf_desc->cpu_addr;
2101 		if (smc_wr_reg_send(link, buf_desc->mr[link->link_idx])) {
2102 			buf_desc->is_reg_err = true;
2103 			return -EFAULT;
2104 		}
2105 		buf_desc->is_reg_mr[link->link_idx] = true;
2106 	}
2107 	return 0;
2108 }
2109 
2110 static int _smcr_buf_map_lgr(struct smc_link *lnk, struct mutex *lock,
2111 			     struct list_head *lst, bool is_rmb)
2112 {
2113 	struct smc_buf_desc *buf_desc, *bf;
2114 	int rc = 0;
2115 
2116 	mutex_lock(lock);
2117 	list_for_each_entry_safe(buf_desc, bf, lst, list) {
2118 		if (!buf_desc->used)
2119 			continue;
2120 		rc = smcr_buf_map_link(buf_desc, is_rmb, lnk);
2121 		if (rc)
2122 			goto out;
2123 	}
2124 out:
2125 	mutex_unlock(lock);
2126 	return rc;
2127 }
2128 
2129 /* map all used buffers of lgr for a new link */
2130 int smcr_buf_map_lgr(struct smc_link *lnk)
2131 {
2132 	struct smc_link_group *lgr = lnk->lgr;
2133 	int i, rc = 0;
2134 
2135 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2136 		rc = _smcr_buf_map_lgr(lnk, &lgr->rmbs_lock,
2137 				       &lgr->rmbs[i], true);
2138 		if (rc)
2139 			return rc;
2140 		rc = _smcr_buf_map_lgr(lnk, &lgr->sndbufs_lock,
2141 				       &lgr->sndbufs[i], false);
2142 		if (rc)
2143 			return rc;
2144 	}
2145 	return 0;
2146 }
2147 
2148 /* register all used buffers of lgr for a new link,
2149  * must be called under lgr->llc_conf_mutex lock
2150  */
2151 int smcr_buf_reg_lgr(struct smc_link *lnk)
2152 {
2153 	struct smc_link_group *lgr = lnk->lgr;
2154 	struct smc_buf_desc *buf_desc, *bf;
2155 	int i, rc = 0;
2156 
2157 	/* reg all RMBs for a new link */
2158 	mutex_lock(&lgr->rmbs_lock);
2159 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2160 		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list) {
2161 			if (!buf_desc->used)
2162 				continue;
2163 			rc = smcr_link_reg_buf(lnk, buf_desc);
2164 			if (rc) {
2165 				mutex_unlock(&lgr->rmbs_lock);
2166 				return rc;
2167 			}
2168 		}
2169 	}
2170 	mutex_unlock(&lgr->rmbs_lock);
2171 
2172 	if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2173 		return rc;
2174 
2175 	/* reg all vzalloced sndbufs for a new link */
2176 	mutex_lock(&lgr->sndbufs_lock);
2177 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2178 		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i], list) {
2179 			if (!buf_desc->used || !buf_desc->is_vm)
2180 				continue;
2181 			rc = smcr_link_reg_buf(lnk, buf_desc);
2182 			if (rc) {
2183 				mutex_unlock(&lgr->sndbufs_lock);
2184 				return rc;
2185 			}
2186 		}
2187 	}
2188 	mutex_unlock(&lgr->sndbufs_lock);
2189 	return rc;
2190 }
2191 
2192 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
2193 						bool is_rmb, int bufsize)
2194 {
2195 	struct smc_buf_desc *buf_desc;
2196 
2197 	/* try to alloc a new buffer */
2198 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2199 	if (!buf_desc)
2200 		return ERR_PTR(-ENOMEM);
2201 
2202 	switch (lgr->buf_type) {
2203 	case SMCR_PHYS_CONT_BUFS:
2204 	case SMCR_MIXED_BUFS:
2205 		buf_desc->order = get_order(bufsize);
2206 		buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
2207 					      __GFP_NOMEMALLOC | __GFP_COMP |
2208 					      __GFP_NORETRY | __GFP_ZERO,
2209 					      buf_desc->order);
2210 		if (buf_desc->pages) {
2211 			buf_desc->cpu_addr =
2212 				(void *)page_address(buf_desc->pages);
2213 			buf_desc->len = bufsize;
2214 			buf_desc->is_vm = false;
2215 			break;
2216 		}
2217 		if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2218 			goto out;
2219 		fallthrough;	// try virtually continguous buf
2220 	case SMCR_VIRT_CONT_BUFS:
2221 		buf_desc->order = get_order(bufsize);
2222 		buf_desc->cpu_addr = vzalloc(PAGE_SIZE << buf_desc->order);
2223 		if (!buf_desc->cpu_addr)
2224 			goto out;
2225 		buf_desc->pages = NULL;
2226 		buf_desc->len = bufsize;
2227 		buf_desc->is_vm = true;
2228 		break;
2229 	}
2230 	return buf_desc;
2231 
2232 out:
2233 	kfree(buf_desc);
2234 	return ERR_PTR(-EAGAIN);
2235 }
2236 
2237 /* map buf_desc on all usable links,
2238  * unused buffers stay mapped as long as the link is up
2239  */
2240 static int smcr_buf_map_usable_links(struct smc_link_group *lgr,
2241 				     struct smc_buf_desc *buf_desc, bool is_rmb)
2242 {
2243 	int i, rc = 0, cnt = 0;
2244 
2245 	/* protect against parallel link reconfiguration */
2246 	mutex_lock(&lgr->llc_conf_mutex);
2247 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2248 		struct smc_link *lnk = &lgr->lnk[i];
2249 
2250 		if (!smc_link_usable(lnk))
2251 			continue;
2252 		if (smcr_buf_map_link(buf_desc, is_rmb, lnk)) {
2253 			rc = -ENOMEM;
2254 			goto out;
2255 		}
2256 		cnt++;
2257 	}
2258 out:
2259 	mutex_unlock(&lgr->llc_conf_mutex);
2260 	if (!rc && !cnt)
2261 		rc = -EINVAL;
2262 	return rc;
2263 }
2264 
2265 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
2266 						bool is_dmb, int bufsize)
2267 {
2268 	struct smc_buf_desc *buf_desc;
2269 	int rc;
2270 
2271 	/* try to alloc a new DMB */
2272 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2273 	if (!buf_desc)
2274 		return ERR_PTR(-ENOMEM);
2275 	if (is_dmb) {
2276 		rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
2277 		if (rc) {
2278 			kfree(buf_desc);
2279 			if (rc == -ENOMEM)
2280 				return ERR_PTR(-EAGAIN);
2281 			if (rc == -ENOSPC)
2282 				return ERR_PTR(-ENOSPC);
2283 			return ERR_PTR(-EIO);
2284 		}
2285 		buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
2286 		/* CDC header stored in buf. So, pretend it was smaller */
2287 		buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
2288 	} else {
2289 		buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
2290 					     __GFP_NOWARN | __GFP_NORETRY |
2291 					     __GFP_NOMEMALLOC);
2292 		if (!buf_desc->cpu_addr) {
2293 			kfree(buf_desc);
2294 			return ERR_PTR(-EAGAIN);
2295 		}
2296 		buf_desc->len = bufsize;
2297 	}
2298 	return buf_desc;
2299 }
2300 
2301 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
2302 {
2303 	struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
2304 	struct smc_connection *conn = &smc->conn;
2305 	struct smc_link_group *lgr = conn->lgr;
2306 	struct list_head *buf_list;
2307 	int bufsize, bufsize_short;
2308 	bool is_dgraded = false;
2309 	struct mutex *lock;	/* lock buffer list */
2310 	int sk_buf_size;
2311 
2312 	if (is_rmb)
2313 		/* use socket recv buffer size (w/o overhead) as start value */
2314 		sk_buf_size = smc->sk.sk_rcvbuf;
2315 	else
2316 		/* use socket send buffer size (w/o overhead) as start value */
2317 		sk_buf_size = smc->sk.sk_sndbuf;
2318 
2319 	for (bufsize_short = smc_compress_bufsize(sk_buf_size, is_smcd, is_rmb);
2320 	     bufsize_short >= 0; bufsize_short--) {
2321 		if (is_rmb) {
2322 			lock = &lgr->rmbs_lock;
2323 			buf_list = &lgr->rmbs[bufsize_short];
2324 		} else {
2325 			lock = &lgr->sndbufs_lock;
2326 			buf_list = &lgr->sndbufs[bufsize_short];
2327 		}
2328 		bufsize = smc_uncompress_bufsize(bufsize_short);
2329 
2330 		/* check for reusable slot in the link group */
2331 		buf_desc = smc_buf_get_slot(bufsize_short, lock, buf_list);
2332 		if (buf_desc) {
2333 			buf_desc->is_dma_need_sync = 0;
2334 			SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, bufsize);
2335 			SMC_STAT_BUF_REUSE(smc, is_smcd, is_rmb);
2336 			break; /* found reusable slot */
2337 		}
2338 
2339 		if (is_smcd)
2340 			buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
2341 		else
2342 			buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
2343 
2344 		if (PTR_ERR(buf_desc) == -ENOMEM)
2345 			break;
2346 		if (IS_ERR(buf_desc)) {
2347 			if (!is_dgraded) {
2348 				is_dgraded = true;
2349 				SMC_STAT_RMB_DOWNGRADED(smc, is_smcd, is_rmb);
2350 			}
2351 			continue;
2352 		}
2353 
2354 		SMC_STAT_RMB_ALLOC(smc, is_smcd, is_rmb);
2355 		SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, bufsize);
2356 		buf_desc->used = 1;
2357 		mutex_lock(lock);
2358 		list_add(&buf_desc->list, buf_list);
2359 		mutex_unlock(lock);
2360 		break; /* found */
2361 	}
2362 
2363 	if (IS_ERR(buf_desc))
2364 		return PTR_ERR(buf_desc);
2365 
2366 	if (!is_smcd) {
2367 		if (smcr_buf_map_usable_links(lgr, buf_desc, is_rmb)) {
2368 			smcr_buf_unuse(buf_desc, is_rmb, lgr);
2369 			return -ENOMEM;
2370 		}
2371 	}
2372 
2373 	if (is_rmb) {
2374 		conn->rmb_desc = buf_desc;
2375 		conn->rmbe_size_short = bufsize_short;
2376 		smc->sk.sk_rcvbuf = bufsize;
2377 		atomic_set(&conn->bytes_to_rcv, 0);
2378 		conn->rmbe_update_limit =
2379 			smc_rmb_wnd_update_limit(buf_desc->len);
2380 		if (is_smcd)
2381 			smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
2382 	} else {
2383 		conn->sndbuf_desc = buf_desc;
2384 		smc->sk.sk_sndbuf = bufsize;
2385 		atomic_set(&conn->sndbuf_space, bufsize);
2386 	}
2387 	return 0;
2388 }
2389 
2390 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
2391 {
2392 	if (!conn->sndbuf_desc->is_dma_need_sync)
2393 		return;
2394 	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd ||
2395 	    !smc_link_active(conn->lnk))
2396 		return;
2397 	smc_ib_sync_sg_for_device(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);
2398 }
2399 
2400 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
2401 {
2402 	int i;
2403 
2404 	if (!conn->rmb_desc->is_dma_need_sync)
2405 		return;
2406 	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd)
2407 		return;
2408 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2409 		if (!smc_link_active(&conn->lgr->lnk[i]))
2410 			continue;
2411 		smc_ib_sync_sg_for_cpu(&conn->lgr->lnk[i], conn->rmb_desc,
2412 				       DMA_FROM_DEVICE);
2413 	}
2414 }
2415 
2416 /* create the send and receive buffer for an SMC socket;
2417  * receive buffers are called RMBs;
2418  * (even though the SMC protocol allows more than one RMB-element per RMB,
2419  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
2420  * extra RMB for every connection in a link group
2421  */
2422 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
2423 {
2424 	int rc;
2425 
2426 	/* create send buffer */
2427 	rc = __smc_buf_create(smc, is_smcd, false);
2428 	if (rc)
2429 		return rc;
2430 	/* create rmb */
2431 	rc = __smc_buf_create(smc, is_smcd, true);
2432 	if (rc) {
2433 		mutex_lock(&smc->conn.lgr->sndbufs_lock);
2434 		list_del(&smc->conn.sndbuf_desc->list);
2435 		mutex_unlock(&smc->conn.lgr->sndbufs_lock);
2436 		smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
2437 		smc->conn.sndbuf_desc = NULL;
2438 	}
2439 	return rc;
2440 }
2441 
2442 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
2443 {
2444 	int i;
2445 
2446 	for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
2447 		if (!test_and_set_bit(i, lgr->rtokens_used_mask))
2448 			return i;
2449 	}
2450 	return -ENOSPC;
2451 }
2452 
2453 static int smc_rtoken_find_by_link(struct smc_link_group *lgr, int lnk_idx,
2454 				   u32 rkey)
2455 {
2456 	int i;
2457 
2458 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2459 		if (test_bit(i, lgr->rtokens_used_mask) &&
2460 		    lgr->rtokens[i][lnk_idx].rkey == rkey)
2461 			return i;
2462 	}
2463 	return -ENOENT;
2464 }
2465 
2466 /* set rtoken for a new link to an existing rmb */
2467 void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
2468 		    __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey)
2469 {
2470 	int rtok_idx;
2471 
2472 	rtok_idx = smc_rtoken_find_by_link(lgr, link_idx, ntohl(nw_rkey_known));
2473 	if (rtok_idx == -ENOENT)
2474 		return;
2475 	lgr->rtokens[rtok_idx][link_idx_new].rkey = ntohl(nw_rkey);
2476 	lgr->rtokens[rtok_idx][link_idx_new].dma_addr = be64_to_cpu(nw_vaddr);
2477 }
2478 
2479 /* set rtoken for a new link whose link_id is given */
2480 void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
2481 		     __be64 nw_vaddr, __be32 nw_rkey)
2482 {
2483 	u64 dma_addr = be64_to_cpu(nw_vaddr);
2484 	u32 rkey = ntohl(nw_rkey);
2485 	bool found = false;
2486 	int link_idx;
2487 
2488 	for (link_idx = 0; link_idx < SMC_LINKS_PER_LGR_MAX; link_idx++) {
2489 		if (lgr->lnk[link_idx].link_id == link_id) {
2490 			found = true;
2491 			break;
2492 		}
2493 	}
2494 	if (!found)
2495 		return;
2496 	lgr->rtokens[rtok_idx][link_idx].rkey = rkey;
2497 	lgr->rtokens[rtok_idx][link_idx].dma_addr = dma_addr;
2498 }
2499 
2500 /* add a new rtoken from peer */
2501 int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey)
2502 {
2503 	struct smc_link_group *lgr = smc_get_lgr(lnk);
2504 	u64 dma_addr = be64_to_cpu(nw_vaddr);
2505 	u32 rkey = ntohl(nw_rkey);
2506 	int i;
2507 
2508 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2509 		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2510 		    lgr->rtokens[i][lnk->link_idx].dma_addr == dma_addr &&
2511 		    test_bit(i, lgr->rtokens_used_mask)) {
2512 			/* already in list */
2513 			return i;
2514 		}
2515 	}
2516 	i = smc_rmb_reserve_rtoken_idx(lgr);
2517 	if (i < 0)
2518 		return i;
2519 	lgr->rtokens[i][lnk->link_idx].rkey = rkey;
2520 	lgr->rtokens[i][lnk->link_idx].dma_addr = dma_addr;
2521 	return i;
2522 }
2523 
2524 /* delete an rtoken from all links */
2525 int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey)
2526 {
2527 	struct smc_link_group *lgr = smc_get_lgr(lnk);
2528 	u32 rkey = ntohl(nw_rkey);
2529 	int i, j;
2530 
2531 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2532 		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2533 		    test_bit(i, lgr->rtokens_used_mask)) {
2534 			for (j = 0; j < SMC_LINKS_PER_LGR_MAX; j++) {
2535 				lgr->rtokens[i][j].rkey = 0;
2536 				lgr->rtokens[i][j].dma_addr = 0;
2537 			}
2538 			clear_bit(i, lgr->rtokens_used_mask);
2539 			return 0;
2540 		}
2541 	}
2542 	return -ENOENT;
2543 }
2544 
2545 /* save rkey and dma_addr received from peer during clc handshake */
2546 int smc_rmb_rtoken_handling(struct smc_connection *conn,
2547 			    struct smc_link *lnk,
2548 			    struct smc_clc_msg_accept_confirm *clc)
2549 {
2550 	conn->rtoken_idx = smc_rtoken_add(lnk, clc->r0.rmb_dma_addr,
2551 					  clc->r0.rmb_rkey);
2552 	if (conn->rtoken_idx < 0)
2553 		return conn->rtoken_idx;
2554 	return 0;
2555 }
2556 
2557 static void smc_core_going_away(void)
2558 {
2559 	struct smc_ib_device *smcibdev;
2560 	struct smcd_dev *smcd;
2561 
2562 	mutex_lock(&smc_ib_devices.mutex);
2563 	list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
2564 		int i;
2565 
2566 		for (i = 0; i < SMC_MAX_PORTS; i++)
2567 			set_bit(i, smcibdev->ports_going_away);
2568 	}
2569 	mutex_unlock(&smc_ib_devices.mutex);
2570 
2571 	mutex_lock(&smcd_dev_list.mutex);
2572 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
2573 		smcd->going_away = 1;
2574 	}
2575 	mutex_unlock(&smcd_dev_list.mutex);
2576 }
2577 
2578 /* Clean up all SMC link groups */
2579 static void smc_lgrs_shutdown(void)
2580 {
2581 	struct smcd_dev *smcd;
2582 
2583 	smc_core_going_away();
2584 
2585 	smc_smcr_terminate_all(NULL);
2586 
2587 	mutex_lock(&smcd_dev_list.mutex);
2588 	list_for_each_entry(smcd, &smcd_dev_list.list, list)
2589 		smc_smcd_terminate_all(smcd);
2590 	mutex_unlock(&smcd_dev_list.mutex);
2591 }
2592 
2593 static int smc_core_reboot_event(struct notifier_block *this,
2594 				 unsigned long event, void *ptr)
2595 {
2596 	smc_lgrs_shutdown();
2597 	smc_ib_unregister_client();
2598 	return 0;
2599 }
2600 
2601 static struct notifier_block smc_reboot_notifier = {
2602 	.notifier_call = smc_core_reboot_event,
2603 };
2604 
2605 int __init smc_core_init(void)
2606 {
2607 	return register_reboot_notifier(&smc_reboot_notifier);
2608 }
2609 
2610 /* Called (from smc_exit) when module is removed */
2611 void smc_core_exit(void)
2612 {
2613 	unregister_reboot_notifier(&smc_reboot_notifier);
2614 	smc_lgrs_shutdown();
2615 }
2616