xref: /linux/net/smc/smc_core.c (revision 6dfafbd0299a60bfb5d5e277fdf100037c7ded07)
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_percpu_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 	conn->lnk = NULL;	/* reset conn->lnk first */
131 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
132 		struct smc_link *lnk = &conn->lgr->lnk[i];
133 
134 		if (lnk->state != expected || lnk->link_is_asym)
135 			continue;
136 		if (conn->lgr->role == SMC_CLNT) {
137 			conn->lnk = lnk; /* temporary, SMC server assigns link*/
138 			break;
139 		}
140 		if (conn->lgr->conns_num % 2) {
141 			for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
142 				struct smc_link *lnk2;
143 
144 				lnk2 = &conn->lgr->lnk[j];
145 				if (lnk2->state == expected &&
146 				    !lnk2->link_is_asym) {
147 					conn->lnk = lnk2;
148 					break;
149 				}
150 			}
151 		}
152 		if (!conn->lnk)
153 			conn->lnk = lnk;
154 		break;
155 	}
156 	if (!conn->lnk)
157 		return SMC_CLC_DECL_NOACTLINK;
158 	atomic_inc(&conn->lnk->conn_cnt);
159 	return 0;
160 }
161 
162 /* Register connection in link group by assigning an alert token
163  * registered in a search tree.
164  * Requires @conns_lock
165  * Note that '0' is a reserved value and not assigned.
166  */
167 static int smc_lgr_register_conn(struct smc_connection *conn, bool first)
168 {
169 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
170 	static atomic_t nexttoken = ATOMIC_INIT(0);
171 	int rc;
172 
173 	if (!conn->lgr->is_smcd) {
174 		rc = smcr_lgr_conn_assign_link(conn, first);
175 		if (rc) {
176 			conn->lgr = NULL;
177 			return rc;
178 		}
179 	}
180 	/* find a new alert_token_local value not yet used by some connection
181 	 * in this link group
182 	 */
183 	sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
184 	while (!conn->alert_token_local) {
185 		conn->alert_token_local = atomic_inc_return(&nexttoken);
186 		if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
187 			conn->alert_token_local = 0;
188 	}
189 	smc_lgr_add_alert_token(conn);
190 	conn->lgr->conns_num++;
191 	return 0;
192 }
193 
194 /* Unregister connection and reset the alert token of the given connection<
195  */
196 static void __smc_lgr_unregister_conn(struct smc_connection *conn)
197 {
198 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
199 	struct smc_link_group *lgr = conn->lgr;
200 
201 	rb_erase(&conn->alert_node, &lgr->conns_all);
202 	if (conn->lnk)
203 		atomic_dec(&conn->lnk->conn_cnt);
204 	lgr->conns_num--;
205 	conn->alert_token_local = 0;
206 	sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
207 }
208 
209 /* Unregister connection from lgr
210  */
211 static void smc_lgr_unregister_conn(struct smc_connection *conn)
212 {
213 	struct smc_link_group *lgr = conn->lgr;
214 
215 	if (!smc_conn_lgr_valid(conn))
216 		return;
217 	write_lock_bh(&lgr->conns_lock);
218 	if (conn->alert_token_local) {
219 		__smc_lgr_unregister_conn(conn);
220 	}
221 	write_unlock_bh(&lgr->conns_lock);
222 }
223 
224 static void smc_lgr_buf_list_add(struct smc_link_group *lgr,
225 				 bool is_rmb,
226 				 struct list_head *buf_list,
227 				 struct smc_buf_desc *buf_desc)
228 {
229 	list_add(&buf_desc->list, buf_list);
230 	if (is_rmb) {
231 		lgr->alloc_rmbs += buf_desc->len;
232 		lgr->alloc_rmbs +=
233 			lgr->is_smcd ? sizeof(struct smcd_cdc_msg) : 0;
234 	} else {
235 		lgr->alloc_sndbufs += buf_desc->len;
236 	}
237 }
238 
239 static void smc_lgr_buf_list_del(struct smc_link_group *lgr,
240 				 bool is_rmb,
241 				 struct smc_buf_desc *buf_desc)
242 {
243 	list_del(&buf_desc->list);
244 	if (is_rmb) {
245 		lgr->alloc_rmbs -= buf_desc->len;
246 		lgr->alloc_rmbs -=
247 			lgr->is_smcd ? sizeof(struct smcd_cdc_msg) : 0;
248 	} else {
249 		lgr->alloc_sndbufs -= buf_desc->len;
250 	}
251 }
252 
253 int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb)
254 {
255 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
256 	char hostname[SMC_MAX_HOSTNAME_LEN + 1];
257 	char smc_seid[SMC_MAX_EID_LEN + 1];
258 	struct nlattr *attrs;
259 	u8 *seid = NULL;
260 	u8 *host = NULL;
261 	void *nlh;
262 
263 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
264 			  &smc_gen_nl_family, NLM_F_MULTI,
265 			  SMC_NETLINK_GET_SYS_INFO);
266 	if (!nlh)
267 		goto errmsg;
268 	if (cb_ctx->pos[0])
269 		goto errout;
270 	attrs = nla_nest_start(skb, SMC_GEN_SYS_INFO);
271 	if (!attrs)
272 		goto errout;
273 	if (nla_put_u8(skb, SMC_NLA_SYS_VER, SMC_V2))
274 		goto errattr;
275 	if (nla_put_u8(skb, SMC_NLA_SYS_REL, SMC_RELEASE))
276 		goto errattr;
277 	if (nla_put_u8(skb, SMC_NLA_SYS_IS_ISM_V2, smc_ism_is_v2_capable()))
278 		goto errattr;
279 	if (nla_put_u8(skb, SMC_NLA_SYS_IS_SMCR_V2, true))
280 		goto errattr;
281 	smc_clc_get_hostname(&host);
282 	if (host) {
283 		memcpy(hostname, host, SMC_MAX_HOSTNAME_LEN);
284 		hostname[SMC_MAX_HOSTNAME_LEN] = 0;
285 		if (nla_put_string(skb, SMC_NLA_SYS_LOCAL_HOST, hostname))
286 			goto errattr;
287 	}
288 	if (smc_ism_is_v2_capable()) {
289 		smc_ism_get_system_eid(&seid);
290 		memcpy(smc_seid, seid, SMC_MAX_EID_LEN);
291 		smc_seid[SMC_MAX_EID_LEN] = 0;
292 		if (nla_put_string(skb, SMC_NLA_SYS_SEID, smc_seid))
293 			goto errattr;
294 	}
295 	nla_nest_end(skb, attrs);
296 	genlmsg_end(skb, nlh);
297 	cb_ctx->pos[0] = 1;
298 	return skb->len;
299 
300 errattr:
301 	nla_nest_cancel(skb, attrs);
302 errout:
303 	genlmsg_cancel(skb, nlh);
304 errmsg:
305 	return skb->len;
306 }
307 
308 /* Fill SMC_NLA_LGR_D_V2_COMMON/SMC_NLA_LGR_R_V2_COMMON nested attributes */
309 static int smc_nl_fill_lgr_v2_common(struct smc_link_group *lgr,
310 				     struct sk_buff *skb,
311 				     struct netlink_callback *cb,
312 				     struct nlattr *v2_attrs)
313 {
314 	char smc_host[SMC_MAX_HOSTNAME_LEN + 1];
315 	char smc_eid[SMC_MAX_EID_LEN + 1];
316 
317 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_VER, lgr->smc_version))
318 		goto errv2attr;
319 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_REL, lgr->peer_smc_release))
320 		goto errv2attr;
321 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_OS, lgr->peer_os))
322 		goto errv2attr;
323 	memcpy(smc_host, lgr->peer_hostname, SMC_MAX_HOSTNAME_LEN);
324 	smc_host[SMC_MAX_HOSTNAME_LEN] = 0;
325 	if (nla_put_string(skb, SMC_NLA_LGR_V2_PEER_HOST, smc_host))
326 		goto errv2attr;
327 	memcpy(smc_eid, lgr->negotiated_eid, SMC_MAX_EID_LEN);
328 	smc_eid[SMC_MAX_EID_LEN] = 0;
329 	if (nla_put_string(skb, SMC_NLA_LGR_V2_NEG_EID, smc_eid))
330 		goto errv2attr;
331 
332 	nla_nest_end(skb, v2_attrs);
333 	return 0;
334 
335 errv2attr:
336 	nla_nest_cancel(skb, v2_attrs);
337 	return -EMSGSIZE;
338 }
339 
340 static int smc_nl_fill_smcr_lgr_v2(struct smc_link_group *lgr,
341 				   struct sk_buff *skb,
342 				   struct netlink_callback *cb)
343 {
344 	struct nlattr *v2_attrs;
345 
346 	v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2);
347 	if (!v2_attrs)
348 		goto errattr;
349 	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_DIRECT, !lgr->uses_gateway))
350 		goto errv2attr;
351 	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_CONNS, lgr->max_conns))
352 		goto errv2attr;
353 	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_LINKS, lgr->max_links))
354 		goto errv2attr;
355 
356 	nla_nest_end(skb, v2_attrs);
357 	return 0;
358 
359 errv2attr:
360 	nla_nest_cancel(skb, v2_attrs);
361 errattr:
362 	return -EMSGSIZE;
363 }
364 
365 static int smc_nl_fill_lgr(struct smc_link_group *lgr,
366 			   struct sk_buff *skb,
367 			   struct netlink_callback *cb)
368 {
369 	char smc_target[SMC_MAX_PNETID_LEN + 1];
370 	struct nlattr *attrs, *v2_attrs;
371 
372 	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCR);
373 	if (!attrs)
374 		goto errout;
375 
376 	if (nla_put_u32(skb, SMC_NLA_LGR_R_ID, *((u32 *)&lgr->id)))
377 		goto errattr;
378 	if (nla_put_u32(skb, SMC_NLA_LGR_R_CONNS_NUM, lgr->conns_num))
379 		goto errattr;
380 	if (nla_put_u8(skb, SMC_NLA_LGR_R_ROLE, lgr->role))
381 		goto errattr;
382 	if (nla_put_u8(skb, SMC_NLA_LGR_R_TYPE, lgr->type))
383 		goto errattr;
384 	if (nla_put_u8(skb, SMC_NLA_LGR_R_BUF_TYPE, lgr->buf_type))
385 		goto errattr;
386 	if (nla_put_u8(skb, SMC_NLA_LGR_R_VLAN_ID, lgr->vlan_id))
387 		goto errattr;
388 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_R_NET_COOKIE,
389 			      lgr->net->net_cookie, SMC_NLA_LGR_R_PAD))
390 		goto errattr;
391 	memcpy(smc_target, lgr->pnet_id, SMC_MAX_PNETID_LEN);
392 	smc_target[SMC_MAX_PNETID_LEN] = 0;
393 	if (nla_put_string(skb, SMC_NLA_LGR_R_PNETID, smc_target))
394 		goto errattr;
395 	if (nla_put_uint(skb, SMC_NLA_LGR_R_SNDBUF_ALLOC, lgr->alloc_sndbufs))
396 		goto errattr;
397 	if (nla_put_uint(skb, SMC_NLA_LGR_R_RMB_ALLOC, lgr->alloc_rmbs))
398 		goto errattr;
399 	if (lgr->smc_version > SMC_V1) {
400 		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2_COMMON);
401 		if (!v2_attrs)
402 			goto errattr;
403 		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
404 			goto errattr;
405 		if (smc_nl_fill_smcr_lgr_v2(lgr, skb, cb))
406 			goto errattr;
407 	}
408 
409 	nla_nest_end(skb, attrs);
410 	return 0;
411 errattr:
412 	nla_nest_cancel(skb, attrs);
413 errout:
414 	return -EMSGSIZE;
415 }
416 
417 static int smc_nl_fill_lgr_link(struct smc_link_group *lgr,
418 				struct smc_link *link,
419 				struct sk_buff *skb,
420 				struct netlink_callback *cb)
421 {
422 	char smc_ibname[IB_DEVICE_NAME_MAX];
423 	u8 smc_gid_target[41];
424 	struct nlattr *attrs;
425 	u32 link_uid = 0;
426 	void *nlh;
427 
428 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
429 			  &smc_gen_nl_family, NLM_F_MULTI,
430 			  SMC_NETLINK_GET_LINK_SMCR);
431 	if (!nlh)
432 		goto errmsg;
433 
434 	attrs = nla_nest_start(skb, SMC_GEN_LINK_SMCR);
435 	if (!attrs)
436 		goto errout;
437 
438 	if (nla_put_u8(skb, SMC_NLA_LINK_ID, link->link_id))
439 		goto errattr;
440 	if (nla_put_u32(skb, SMC_NLA_LINK_STATE, link->state))
441 		goto errattr;
442 	if (nla_put_u32(skb, SMC_NLA_LINK_CONN_CNT,
443 			atomic_read(&link->conn_cnt)))
444 		goto errattr;
445 	if (nla_put_u8(skb, SMC_NLA_LINK_IB_PORT, link->ibport))
446 		goto errattr;
447 	if (nla_put_u32(skb, SMC_NLA_LINK_NET_DEV, link->ndev_ifidx))
448 		goto errattr;
449 	snprintf(smc_ibname, sizeof(smc_ibname), "%s", link->ibname);
450 	if (nla_put_string(skb, SMC_NLA_LINK_IB_DEV, smc_ibname))
451 		goto errattr;
452 	memcpy(&link_uid, link->link_uid, sizeof(link_uid));
453 	if (nla_put_u32(skb, SMC_NLA_LINK_UID, link_uid))
454 		goto errattr;
455 	memcpy(&link_uid, link->peer_link_uid, sizeof(link_uid));
456 	if (nla_put_u32(skb, SMC_NLA_LINK_PEER_UID, link_uid))
457 		goto errattr;
458 	memset(smc_gid_target, 0, sizeof(smc_gid_target));
459 	smc_gid_be16_convert(smc_gid_target, link->gid);
460 	if (nla_put_string(skb, SMC_NLA_LINK_GID, smc_gid_target))
461 		goto errattr;
462 	memset(smc_gid_target, 0, sizeof(smc_gid_target));
463 	smc_gid_be16_convert(smc_gid_target, link->peer_gid);
464 	if (nla_put_string(skb, SMC_NLA_LINK_PEER_GID, smc_gid_target))
465 		goto errattr;
466 
467 	nla_nest_end(skb, attrs);
468 	genlmsg_end(skb, nlh);
469 	return 0;
470 errattr:
471 	nla_nest_cancel(skb, attrs);
472 errout:
473 	genlmsg_cancel(skb, nlh);
474 errmsg:
475 	return -EMSGSIZE;
476 }
477 
478 static int smc_nl_handle_lgr(struct smc_link_group *lgr,
479 			     struct sk_buff *skb,
480 			     struct netlink_callback *cb,
481 			     bool list_links)
482 {
483 	void *nlh;
484 	int i;
485 
486 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
487 			  &smc_gen_nl_family, NLM_F_MULTI,
488 			  SMC_NETLINK_GET_LGR_SMCR);
489 	if (!nlh)
490 		goto errmsg;
491 	if (smc_nl_fill_lgr(lgr, skb, cb))
492 		goto errout;
493 
494 	genlmsg_end(skb, nlh);
495 	if (!list_links)
496 		goto out;
497 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
498 		if (!smc_link_usable(&lgr->lnk[i]))
499 			continue;
500 		if (smc_nl_fill_lgr_link(lgr, &lgr->lnk[i], skb, cb))
501 			goto errout;
502 	}
503 out:
504 	return 0;
505 
506 errout:
507 	genlmsg_cancel(skb, nlh);
508 errmsg:
509 	return -EMSGSIZE;
510 }
511 
512 static void smc_nl_fill_lgr_list(struct smc_lgr_list *smc_lgr,
513 				 struct sk_buff *skb,
514 				 struct netlink_callback *cb,
515 				 bool list_links)
516 {
517 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
518 	struct smc_link_group *lgr;
519 	int snum = cb_ctx->pos[0];
520 	int num = 0;
521 
522 	spin_lock_bh(&smc_lgr->lock);
523 	list_for_each_entry(lgr, &smc_lgr->list, list) {
524 		if (num < snum)
525 			goto next;
526 		if (smc_nl_handle_lgr(lgr, skb, cb, list_links))
527 			goto errout;
528 next:
529 		num++;
530 	}
531 errout:
532 	spin_unlock_bh(&smc_lgr->lock);
533 	cb_ctx->pos[0] = num;
534 }
535 
536 static int smc_nl_fill_smcd_lgr(struct smc_link_group *lgr,
537 				struct sk_buff *skb,
538 				struct netlink_callback *cb)
539 {
540 	char smc_pnet[SMC_MAX_PNETID_LEN + 1];
541 	struct smcd_dev *smcd = lgr->smcd;
542 	struct smcd_gid smcd_gid;
543 	struct nlattr *attrs;
544 	void *nlh;
545 
546 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
547 			  &smc_gen_nl_family, NLM_F_MULTI,
548 			  SMC_NETLINK_GET_LGR_SMCD);
549 	if (!nlh)
550 		goto errmsg;
551 
552 	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCD);
553 	if (!attrs)
554 		goto errout;
555 
556 	if (nla_put_u32(skb, SMC_NLA_LGR_D_ID, *((u32 *)&lgr->id)))
557 		goto errattr;
558 	copy_to_smcdgid(&smcd_gid, &smcd->dibs->gid);
559 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_GID,
560 			      smcd_gid.gid, SMC_NLA_LGR_D_PAD))
561 		goto errattr;
562 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_EXT_GID,
563 			      smcd_gid.gid_ext, SMC_NLA_LGR_D_PAD))
564 		goto errattr;
565 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_PEER_GID, lgr->peer_gid.gid,
566 			      SMC_NLA_LGR_D_PAD))
567 		goto errattr;
568 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_PEER_EXT_GID,
569 			      lgr->peer_gid.gid_ext, SMC_NLA_LGR_D_PAD))
570 		goto errattr;
571 	if (nla_put_u8(skb, SMC_NLA_LGR_D_VLAN_ID, lgr->vlan_id))
572 		goto errattr;
573 	if (nla_put_u32(skb, SMC_NLA_LGR_D_CONNS_NUM, lgr->conns_num))
574 		goto errattr;
575 	if (nla_put_u32(skb, SMC_NLA_LGR_D_CHID, smc_ism_get_chid(lgr->smcd)))
576 		goto errattr;
577 	if (nla_put_uint(skb, SMC_NLA_LGR_D_SNDBUF_ALLOC, lgr->alloc_sndbufs))
578 		goto errattr;
579 	if (nla_put_uint(skb, SMC_NLA_LGR_D_DMB_ALLOC, lgr->alloc_rmbs))
580 		goto errattr;
581 	memcpy(smc_pnet, lgr->smcd->pnetid, SMC_MAX_PNETID_LEN);
582 	smc_pnet[SMC_MAX_PNETID_LEN] = 0;
583 	if (nla_put_string(skb, SMC_NLA_LGR_D_PNETID, smc_pnet))
584 		goto errattr;
585 	if (lgr->smc_version > SMC_V1) {
586 		struct nlattr *v2_attrs;
587 
588 		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_D_V2_COMMON);
589 		if (!v2_attrs)
590 			goto errattr;
591 		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
592 			goto errattr;
593 	}
594 	nla_nest_end(skb, attrs);
595 	genlmsg_end(skb, nlh);
596 	return 0;
597 
598 errattr:
599 	nla_nest_cancel(skb, attrs);
600 errout:
601 	genlmsg_cancel(skb, nlh);
602 errmsg:
603 	return -EMSGSIZE;
604 }
605 
606 static int smc_nl_handle_smcd_lgr(struct smcd_dev *dev,
607 				  struct sk_buff *skb,
608 				  struct netlink_callback *cb)
609 {
610 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
611 	struct smc_link_group *lgr;
612 	int snum = cb_ctx->pos[1];
613 	int rc = 0, num = 0;
614 
615 	spin_lock_bh(&dev->lgr_lock);
616 	list_for_each_entry(lgr, &dev->lgr_list, list) {
617 		if (!lgr->is_smcd)
618 			continue;
619 		if (num < snum)
620 			goto next;
621 		rc = smc_nl_fill_smcd_lgr(lgr, skb, cb);
622 		if (rc)
623 			goto errout;
624 next:
625 		num++;
626 	}
627 errout:
628 	spin_unlock_bh(&dev->lgr_lock);
629 	cb_ctx->pos[1] = num;
630 	return rc;
631 }
632 
633 static int smc_nl_fill_smcd_dev(struct smcd_dev_list *dev_list,
634 				struct sk_buff *skb,
635 				struct netlink_callback *cb)
636 {
637 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
638 	struct smcd_dev *smcd_dev;
639 	int snum = cb_ctx->pos[0];
640 	int rc = 0, num = 0;
641 
642 	mutex_lock(&dev_list->mutex);
643 	list_for_each_entry(smcd_dev, &dev_list->list, list) {
644 		if (list_empty(&smcd_dev->lgr_list))
645 			continue;
646 		if (num < snum)
647 			goto next;
648 		rc = smc_nl_handle_smcd_lgr(smcd_dev, skb, cb);
649 		if (rc)
650 			goto errout;
651 next:
652 		num++;
653 	}
654 errout:
655 	mutex_unlock(&dev_list->mutex);
656 	cb_ctx->pos[0] = num;
657 	return rc;
658 }
659 
660 int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
661 {
662 	bool list_links = false;
663 
664 	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
665 	return skb->len;
666 }
667 
668 int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb)
669 {
670 	bool list_links = true;
671 
672 	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
673 	return skb->len;
674 }
675 
676 int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
677 {
678 	smc_nl_fill_smcd_dev(&smcd_dev_list, skb, cb);
679 	return skb->len;
680 }
681 
682 void smc_lgr_cleanup_early(struct smc_link_group *lgr)
683 {
684 	spinlock_t *lgr_lock;
685 
686 	if (!lgr)
687 		return;
688 
689 	smc_lgr_list_head(lgr, &lgr_lock);
690 	spin_lock_bh(lgr_lock);
691 	/* do not use this link group for new connections */
692 	if (!list_empty(&lgr->list))
693 		list_del_init(&lgr->list);
694 	spin_unlock_bh(lgr_lock);
695 	__smc_lgr_terminate(lgr, true);
696 }
697 
698 static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
699 {
700 	int i;
701 
702 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
703 		struct smc_link *lnk = &lgr->lnk[i];
704 
705 		if (smc_link_sendable(lnk))
706 			lnk->state = SMC_LNK_INACTIVE;
707 	}
708 	wake_up_all(&lgr->llc_msg_waiter);
709 	wake_up_all(&lgr->llc_flow_waiter);
710 }
711 
712 static void smc_lgr_free(struct smc_link_group *lgr);
713 
714 static void smc_lgr_free_work(struct work_struct *work)
715 {
716 	struct smc_link_group *lgr = container_of(to_delayed_work(work),
717 						  struct smc_link_group,
718 						  free_work);
719 	spinlock_t *lgr_lock;
720 	bool conns;
721 
722 	smc_lgr_list_head(lgr, &lgr_lock);
723 	spin_lock_bh(lgr_lock);
724 	if (lgr->freeing) {
725 		spin_unlock_bh(lgr_lock);
726 		return;
727 	}
728 	read_lock_bh(&lgr->conns_lock);
729 	conns = RB_EMPTY_ROOT(&lgr->conns_all);
730 	read_unlock_bh(&lgr->conns_lock);
731 	if (!conns) { /* number of lgr connections is no longer zero */
732 		spin_unlock_bh(lgr_lock);
733 		return;
734 	}
735 	list_del_init(&lgr->list); /* remove from smc_lgr_list */
736 	lgr->freeing = 1; /* this instance does the freeing, no new schedule */
737 	spin_unlock_bh(lgr_lock);
738 	cancel_delayed_work(&lgr->free_work);
739 
740 	if (!lgr->is_smcd && !lgr->terminating)
741 		smc_llc_send_link_delete_all(lgr, true,
742 					     SMC_LLC_DEL_PROG_INIT_TERM);
743 	if (lgr->is_smcd && !lgr->terminating)
744 		smc_ism_signal_shutdown(lgr);
745 	if (!lgr->is_smcd)
746 		smcr_lgr_link_deactivate_all(lgr);
747 	smc_lgr_free(lgr);
748 }
749 
750 static void smc_lgr_terminate_work(struct work_struct *work)
751 {
752 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
753 						  terminate_work);
754 
755 	__smc_lgr_terminate(lgr, true);
756 }
757 
758 /* return next unique link id for the lgr */
759 static u8 smcr_next_link_id(struct smc_link_group *lgr)
760 {
761 	u8 link_id;
762 	int i;
763 
764 	while (1) {
765 again:
766 		link_id = ++lgr->next_link_id;
767 		if (!link_id)	/* skip zero as link_id */
768 			link_id = ++lgr->next_link_id;
769 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
770 			if (smc_link_usable(&lgr->lnk[i]) &&
771 			    lgr->lnk[i].link_id == link_id)
772 				goto again;
773 		}
774 		break;
775 	}
776 	return link_id;
777 }
778 
779 static void smcr_copy_dev_info_to_link(struct smc_link *link)
780 {
781 	struct smc_ib_device *smcibdev = link->smcibdev;
782 
783 	snprintf(link->ibname, sizeof(link->ibname), "%s",
784 		 smcibdev->ibdev->name);
785 	link->ndev_ifidx = smcibdev->ndev_ifidx[link->ibport - 1];
786 }
787 
788 int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
789 		   u8 link_idx, struct smc_init_info *ini)
790 {
791 	struct smc_ib_device *smcibdev;
792 	u8 rndvec[3];
793 	int rc;
794 
795 	if (lgr->smc_version == SMC_V2) {
796 		lnk->smcibdev = ini->smcrv2.ib_dev_v2;
797 		lnk->ibport = ini->smcrv2.ib_port_v2;
798 		lnk->wr_rx_sge_cnt = lnk->smcibdev->ibdev->attrs.max_recv_sge < 2 ? 1 : 2;
799 		lnk->wr_rx_buflen = smc_link_shared_v2_rxbuf(lnk) ?
800 			SMC_WR_BUF_SIZE : SMC_WR_BUF_V2_SIZE;
801 	} else {
802 		lnk->smcibdev = ini->ib_dev;
803 		lnk->ibport = ini->ib_port;
804 		lnk->wr_rx_sge_cnt = 1;
805 		lnk->wr_rx_buflen = SMC_WR_BUF_SIZE;
806 	}
807 	get_device(&lnk->smcibdev->ibdev->dev);
808 	atomic_inc(&lnk->smcibdev->lnk_cnt);
809 	refcount_set(&lnk->refcnt, 1); /* link refcnt is set to 1 */
810 	lnk->clearing = 0;
811 	lnk->path_mtu = lnk->smcibdev->pattr[lnk->ibport - 1].active_mtu;
812 	lnk->link_id = smcr_next_link_id(lgr);
813 	lnk->max_send_wr = lgr->max_send_wr;
814 	lnk->max_recv_wr = lgr->max_recv_wr;
815 	lnk->lgr = lgr;
816 	smc_lgr_hold(lgr); /* lgr_put in smcr_link_clear() */
817 	lnk->link_idx = link_idx;
818 	lnk->wr_rx_id_compl = 0;
819 	smc_ibdev_cnt_inc(lnk);
820 	smcr_copy_dev_info_to_link(lnk);
821 	atomic_set(&lnk->conn_cnt, 0);
822 	smc_llc_link_set_uid(lnk);
823 	INIT_WORK(&lnk->link_down_wrk, smc_link_down_work);
824 	if (!lnk->smcibdev->initialized) {
825 		rc = (int)smc_ib_setup_per_ibdev(lnk->smcibdev);
826 		if (rc)
827 			goto out;
828 	}
829 	get_random_bytes(rndvec, sizeof(rndvec));
830 	lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
831 		(rndvec[2] << 16);
832 	rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
833 				  ini->vlan_id, lnk->gid, &lnk->sgid_index,
834 				  lgr->smc_version == SMC_V2 ?
835 						  &ini->smcrv2 : NULL);
836 	if (rc)
837 		goto out;
838 	rc = smc_llc_link_init(lnk);
839 	if (rc)
840 		goto out;
841 	rc = smc_ib_create_protection_domain(lnk);
842 	if (rc)
843 		goto clear_llc_lnk;
844 	do {
845 		rc = smc_ib_create_queue_pair(lnk);
846 		if (rc)
847 			goto dealloc_pd;
848 		rc = smc_wr_alloc_link_mem(lnk);
849 		if (!rc)
850 			break;
851 		else if (rc != -ENOMEM) /* give up */
852 			goto destroy_qp;
853 		/* retry with smaller ... */
854 		lnk->max_send_wr /= 2;
855 		lnk->max_recv_wr /= 2;
856 		/* ... unless droping below old SMC_WR_BUF_SIZE */
857 		if (lnk->max_send_wr < 16 || lnk->max_recv_wr < 48)
858 			goto destroy_qp;
859 		smc_ib_destroy_queue_pair(lnk);
860 	} while (1);
861 
862 	rc = smc_wr_create_link(lnk);
863 	if (rc)
864 		goto free_link_mem;
865 	lnk->state = SMC_LNK_ACTIVATING;
866 	return 0;
867 
868 free_link_mem:
869 	smc_wr_free_link_mem(lnk);
870 destroy_qp:
871 	smc_ib_destroy_queue_pair(lnk);
872 dealloc_pd:
873 	smc_ib_dealloc_protection_domain(lnk);
874 clear_llc_lnk:
875 	smc_llc_link_clear(lnk, false);
876 out:
877 	smc_ibdev_cnt_dec(lnk);
878 	put_device(&lnk->smcibdev->ibdev->dev);
879 	smcibdev = lnk->smcibdev;
880 	memset(lnk, 0, sizeof(struct smc_link));
881 	lnk->state = SMC_LNK_UNUSED;
882 	if (!atomic_dec_return(&smcibdev->lnk_cnt))
883 		wake_up(&smcibdev->lnks_deleted);
884 	smc_lgr_put(lgr); /* lgr_hold above */
885 	return rc;
886 }
887 
888 /* create a new SMC link group */
889 static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
890 {
891 	struct smc_link_group *lgr;
892 	struct list_head *lgr_list;
893 	struct smcd_dev *smcd;
894 	struct smc_link *lnk;
895 	spinlock_t *lgr_lock;
896 	u8 link_idx;
897 	int rc = 0;
898 	int i;
899 
900 	if (ini->is_smcd && ini->vlan_id) {
901 		if (smc_ism_get_vlan(ini->ism_dev[ini->ism_selected],
902 				     ini->vlan_id)) {
903 			rc = SMC_CLC_DECL_ISMVLANERR;
904 			goto out;
905 		}
906 	}
907 
908 	lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
909 	if (!lgr) {
910 		rc = SMC_CLC_DECL_MEM;
911 		goto ism_put_vlan;
912 	}
913 	lgr->tx_wq = alloc_workqueue("smc_tx_wq-%*phN", WQ_PERCPU, 0,
914 				     SMC_LGR_ID_SIZE, &lgr->id);
915 	if (!lgr->tx_wq) {
916 		rc = -ENOMEM;
917 		goto free_lgr;
918 	}
919 	lgr->is_smcd = ini->is_smcd;
920 	lgr->sync_err = 0;
921 	lgr->terminating = 0;
922 	lgr->freeing = 0;
923 	lgr->vlan_id = ini->vlan_id;
924 	refcount_set(&lgr->refcnt, 1); /* set lgr refcnt to 1 */
925 	init_rwsem(&lgr->sndbufs_lock);
926 	init_rwsem(&lgr->rmbs_lock);
927 	rwlock_init(&lgr->conns_lock);
928 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
929 		INIT_LIST_HEAD(&lgr->sndbufs[i]);
930 		INIT_LIST_HEAD(&lgr->rmbs[i]);
931 	}
932 	lgr->next_link_id = 0;
933 	smc_lgr_list.num += SMC_LGR_NUM_INCR;
934 	memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
935 	INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
936 	INIT_WORK(&lgr->terminate_work, smc_lgr_terminate_work);
937 	lgr->conns_all = RB_ROOT;
938 	if (ini->is_smcd) {
939 		/* SMC-D specific settings */
940 		smcd = ini->ism_dev[ini->ism_selected];
941 		get_device(&smcd->dibs->dev);
942 		lgr->peer_gid.gid =
943 			ini->ism_peer_gid[ini->ism_selected].gid;
944 		lgr->peer_gid.gid_ext =
945 			ini->ism_peer_gid[ini->ism_selected].gid_ext;
946 		lgr->smcd = ini->ism_dev[ini->ism_selected];
947 		lgr_list = &ini->ism_dev[ini->ism_selected]->lgr_list;
948 		lgr_lock = &lgr->smcd->lgr_lock;
949 		lgr->smc_version = ini->smcd_version;
950 		lgr->peer_shutdown = 0;
951 		atomic_inc(&ini->ism_dev[ini->ism_selected]->lgr_cnt);
952 	} else {
953 		/* SMC-R specific settings */
954 		struct smc_ib_device *ibdev;
955 		int ibport;
956 
957 		lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
958 		lgr->smc_version = ini->smcr_version;
959 		memcpy(lgr->peer_systemid, ini->peer_systemid,
960 		       SMC_SYSTEMID_LEN);
961 		if (lgr->smc_version == SMC_V2) {
962 			ibdev = ini->smcrv2.ib_dev_v2;
963 			ibport = ini->smcrv2.ib_port_v2;
964 			lgr->saddr = ini->smcrv2.saddr;
965 			lgr->uses_gateway = ini->smcrv2.uses_gateway;
966 			memcpy(lgr->nexthop_mac, ini->smcrv2.nexthop_mac,
967 			       ETH_ALEN);
968 			lgr->max_conns = ini->max_conns;
969 			lgr->max_links = ini->max_links;
970 		} else {
971 			ibdev = ini->ib_dev;
972 			ibport = ini->ib_port;
973 			lgr->max_conns = SMC_CONN_PER_LGR_MAX;
974 			lgr->max_links = SMC_LINKS_ADD_LNK_MAX;
975 		}
976 		memcpy(lgr->pnet_id, ibdev->pnetid[ibport - 1],
977 		       SMC_MAX_PNETID_LEN);
978 		rc = smc_wr_alloc_lgr_mem(lgr);
979 		if (rc)
980 			goto free_wq;
981 		smc_llc_lgr_init(lgr, smc);
982 
983 		link_idx = SMC_SINGLE_LINK;
984 		lnk = &lgr->lnk[link_idx];
985 		rc = smcr_link_init(lgr, lnk, link_idx, ini);
986 		if (rc) {
987 			smc_wr_free_lgr_mem(lgr);
988 			goto free_wq;
989 		}
990 		lgr->net = smc_ib_net(lnk->smcibdev);
991 		lgr_list = &smc_lgr_list.list;
992 		lgr_lock = &smc_lgr_list.lock;
993 		lgr->buf_type = lgr->net->smc.sysctl_smcr_buf_type;
994 		atomic_inc(&lgr_cnt);
995 	}
996 	smc->conn.lgr = lgr;
997 	spin_lock_bh(lgr_lock);
998 	list_add_tail(&lgr->list, lgr_list);
999 	spin_unlock_bh(lgr_lock);
1000 	return 0;
1001 
1002 free_wq:
1003 	destroy_workqueue(lgr->tx_wq);
1004 free_lgr:
1005 	kfree(lgr);
1006 ism_put_vlan:
1007 	if (ini->is_smcd && ini->vlan_id)
1008 		smc_ism_put_vlan(ini->ism_dev[ini->ism_selected], ini->vlan_id);
1009 out:
1010 	if (rc < 0) {
1011 		if (rc == -ENOMEM)
1012 			rc = SMC_CLC_DECL_MEM;
1013 		else
1014 			rc = SMC_CLC_DECL_INTERR;
1015 	}
1016 	return rc;
1017 }
1018 
1019 static int smc_write_space(struct smc_connection *conn)
1020 {
1021 	int buffer_len = conn->peer_rmbe_size;
1022 	union smc_host_cursor prod;
1023 	union smc_host_cursor cons;
1024 	int space;
1025 
1026 	smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
1027 	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
1028 	/* determine rx_buf space */
1029 	space = buffer_len - smc_curs_diff(buffer_len, &cons, &prod);
1030 	return space;
1031 }
1032 
1033 static int smc_switch_cursor(struct smc_sock *smc, struct smc_cdc_tx_pend *pend,
1034 			     struct smc_wr_buf *wr_buf)
1035 {
1036 	struct smc_connection *conn = &smc->conn;
1037 	union smc_host_cursor cons, fin;
1038 	int rc = 0;
1039 	int diff;
1040 
1041 	smc_curs_copy(&conn->tx_curs_sent, &conn->tx_curs_fin, conn);
1042 	smc_curs_copy(&fin, &conn->local_tx_ctrl_fin, conn);
1043 	/* set prod cursor to old state, enforce tx_rdma_writes() */
1044 	smc_curs_copy(&conn->local_tx_ctrl.prod, &fin, conn);
1045 	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
1046 
1047 	if (smc_curs_comp(conn->peer_rmbe_size, &cons, &fin) < 0) {
1048 		/* cons cursor advanced more than fin, and prod was set
1049 		 * fin above, so now prod is smaller than cons. Fix that.
1050 		 */
1051 		diff = smc_curs_diff(conn->peer_rmbe_size, &fin, &cons);
1052 		smc_curs_add(conn->sndbuf_desc->len,
1053 			     &conn->tx_curs_sent, diff);
1054 		smc_curs_add(conn->sndbuf_desc->len,
1055 			     &conn->tx_curs_fin, diff);
1056 
1057 		smp_mb__before_atomic();
1058 		atomic_add(diff, &conn->sndbuf_space);
1059 		smp_mb__after_atomic();
1060 
1061 		smc_curs_add(conn->peer_rmbe_size,
1062 			     &conn->local_tx_ctrl.prod, diff);
1063 		smc_curs_add(conn->peer_rmbe_size,
1064 			     &conn->local_tx_ctrl_fin, diff);
1065 	}
1066 	/* recalculate, value is used by tx_rdma_writes() */
1067 	atomic_set(&smc->conn.peer_rmbe_space, smc_write_space(conn));
1068 
1069 	if (smc->sk.sk_state != SMC_INIT &&
1070 	    smc->sk.sk_state != SMC_CLOSED) {
1071 		rc = smcr_cdc_msg_send_validation(conn, pend, wr_buf);
1072 		if (!rc) {
1073 			queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 0);
1074 			smc->sk.sk_data_ready(&smc->sk);
1075 		}
1076 	} else {
1077 		smc_wr_tx_put_slot(conn->lnk,
1078 				   (struct smc_wr_tx_pend_priv *)pend);
1079 	}
1080 	return rc;
1081 }
1082 
1083 void smc_switch_link_and_count(struct smc_connection *conn,
1084 			       struct smc_link *to_lnk)
1085 {
1086 	atomic_dec(&conn->lnk->conn_cnt);
1087 	/* link_hold in smc_conn_create() */
1088 	smcr_link_put(conn->lnk);
1089 	conn->lnk = to_lnk;
1090 	atomic_inc(&conn->lnk->conn_cnt);
1091 	/* link_put in smc_conn_free() */
1092 	smcr_link_hold(conn->lnk);
1093 }
1094 
1095 struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
1096 				  struct smc_link *from_lnk, bool is_dev_err)
1097 {
1098 	struct smc_link *to_lnk = NULL;
1099 	struct smc_cdc_tx_pend *pend;
1100 	struct smc_connection *conn;
1101 	struct smc_wr_buf *wr_buf;
1102 	struct smc_sock *smc;
1103 	struct rb_node *node;
1104 	int i, rc = 0;
1105 
1106 	/* link is inactive, wake up tx waiters */
1107 	smc_wr_wakeup_tx_wait(from_lnk);
1108 
1109 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1110 		if (!smc_link_active(&lgr->lnk[i]) || i == from_lnk->link_idx)
1111 			continue;
1112 		if (is_dev_err && from_lnk->smcibdev == lgr->lnk[i].smcibdev &&
1113 		    from_lnk->ibport == lgr->lnk[i].ibport) {
1114 			continue;
1115 		}
1116 		to_lnk = &lgr->lnk[i];
1117 		break;
1118 	}
1119 	if (!to_lnk || !smc_wr_tx_link_hold(to_lnk)) {
1120 		smc_lgr_terminate_sched(lgr);
1121 		return NULL;
1122 	}
1123 again:
1124 	read_lock_bh(&lgr->conns_lock);
1125 	for (node = rb_first(&lgr->conns_all); node; node = rb_next(node)) {
1126 		conn = rb_entry(node, struct smc_connection, alert_node);
1127 		if (conn->lnk != from_lnk)
1128 			continue;
1129 		smc = container_of(conn, struct smc_sock, conn);
1130 		/* conn->lnk not yet set in SMC_INIT state */
1131 		if (smc->sk.sk_state == SMC_INIT)
1132 			continue;
1133 		if (smc->sk.sk_state == SMC_CLOSED ||
1134 		    smc->sk.sk_state == SMC_PEERCLOSEWAIT1 ||
1135 		    smc->sk.sk_state == SMC_PEERCLOSEWAIT2 ||
1136 		    smc->sk.sk_state == SMC_APPFINCLOSEWAIT ||
1137 		    smc->sk.sk_state == SMC_APPCLOSEWAIT1 ||
1138 		    smc->sk.sk_state == SMC_APPCLOSEWAIT2 ||
1139 		    smc->sk.sk_state == SMC_PEERFINCLOSEWAIT ||
1140 		    smc->sk.sk_state == SMC_PEERABORTWAIT ||
1141 		    smc->sk.sk_state == SMC_PROCESSABORT) {
1142 			spin_lock_bh(&conn->send_lock);
1143 			smc_switch_link_and_count(conn, to_lnk);
1144 			spin_unlock_bh(&conn->send_lock);
1145 			continue;
1146 		}
1147 		sock_hold(&smc->sk);
1148 		read_unlock_bh(&lgr->conns_lock);
1149 		/* pre-fetch buffer outside of send_lock, might sleep */
1150 		rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend);
1151 		if (rc)
1152 			goto err_out;
1153 		/* avoid race with smcr_tx_sndbuf_nonempty() */
1154 		spin_lock_bh(&conn->send_lock);
1155 		smc_switch_link_and_count(conn, to_lnk);
1156 		rc = smc_switch_cursor(smc, pend, wr_buf);
1157 		spin_unlock_bh(&conn->send_lock);
1158 		sock_put(&smc->sk);
1159 		if (rc)
1160 			goto err_out;
1161 		goto again;
1162 	}
1163 	read_unlock_bh(&lgr->conns_lock);
1164 	smc_wr_tx_link_put(to_lnk);
1165 	return to_lnk;
1166 
1167 err_out:
1168 	smcr_link_down_cond_sched(to_lnk);
1169 	smc_wr_tx_link_put(to_lnk);
1170 	return NULL;
1171 }
1172 
1173 static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb,
1174 			   struct smc_link_group *lgr)
1175 {
1176 	struct rw_semaphore *lock;	/* lock buffer list */
1177 	int rc;
1178 
1179 	if (is_rmb && buf_desc->is_conf_rkey && !list_empty(&lgr->list)) {
1180 		/* unregister rmb with peer */
1181 		rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
1182 		if (!rc) {
1183 			/* protect against smc_llc_cli_rkey_exchange() */
1184 			down_read(&lgr->llc_conf_mutex);
1185 			smc_llc_do_delete_rkey(lgr, buf_desc);
1186 			buf_desc->is_conf_rkey = false;
1187 			up_read(&lgr->llc_conf_mutex);
1188 			smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1189 		}
1190 	}
1191 
1192 	if (buf_desc->is_reg_err) {
1193 		/* buf registration failed, reuse not possible */
1194 		lock = is_rmb ? &lgr->rmbs_lock :
1195 				&lgr->sndbufs_lock;
1196 		down_write(lock);
1197 		smc_lgr_buf_list_del(lgr, is_rmb, buf_desc);
1198 		up_write(lock);
1199 
1200 		smc_buf_free(lgr, is_rmb, buf_desc);
1201 	} else {
1202 		/* memzero_explicit provides potential memory barrier semantics */
1203 		memzero_explicit(buf_desc->cpu_addr, buf_desc->len);
1204 		WRITE_ONCE(buf_desc->used, 0);
1205 	}
1206 }
1207 
1208 static void smcd_buf_detach(struct smc_connection *conn)
1209 {
1210 	struct smcd_dev *smcd = conn->lgr->smcd;
1211 	u64 peer_token = conn->peer_token;
1212 
1213 	if (!conn->sndbuf_desc)
1214 		return;
1215 
1216 	smc_ism_detach_dmb(smcd, peer_token);
1217 
1218 	kfree(conn->sndbuf_desc);
1219 	conn->sndbuf_desc = NULL;
1220 }
1221 
1222 static void smc_buf_unuse(struct smc_connection *conn,
1223 			  struct smc_link_group *lgr)
1224 {
1225 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1226 	bool is_smcd = lgr->is_smcd;
1227 	int bufsize;
1228 
1229 	if (conn->sndbuf_desc) {
1230 		bufsize = conn->sndbuf_desc->len;
1231 		if (!is_smcd && conn->sndbuf_desc->is_vm) {
1232 			smcr_buf_unuse(conn->sndbuf_desc, false, lgr);
1233 		} else {
1234 			memzero_explicit(conn->sndbuf_desc->cpu_addr, bufsize);
1235 			WRITE_ONCE(conn->sndbuf_desc->used, 0);
1236 		}
1237 		SMC_STAT_RMB_SIZE(smc, is_smcd, false, false, bufsize);
1238 	}
1239 	if (conn->rmb_desc) {
1240 		bufsize = conn->rmb_desc->len;
1241 		if (!is_smcd) {
1242 			smcr_buf_unuse(conn->rmb_desc, true, lgr);
1243 		} else {
1244 			bufsize += sizeof(struct smcd_cdc_msg);
1245 			memzero_explicit(conn->rmb_desc->cpu_addr, bufsize);
1246 			WRITE_ONCE(conn->rmb_desc->used, 0);
1247 		}
1248 		SMC_STAT_RMB_SIZE(smc, is_smcd, true, false, bufsize);
1249 	}
1250 }
1251 
1252 /* remove a finished connection from its link group */
1253 void smc_conn_free(struct smc_connection *conn)
1254 {
1255 	struct smc_link_group *lgr = conn->lgr;
1256 
1257 	if (!lgr || conn->freed)
1258 		/* Connection has never been registered in a
1259 		 * link group, or has already been freed.
1260 		 */
1261 		return;
1262 
1263 	conn->freed = 1;
1264 	if (!smc_conn_lgr_valid(conn))
1265 		/* Connection has already unregistered from
1266 		 * link group.
1267 		 */
1268 		goto lgr_put;
1269 
1270 	if (lgr->is_smcd) {
1271 		if (!list_empty(&lgr->list))
1272 			smc_ism_unset_conn(conn);
1273 		if (smc_ism_support_dmb_nocopy(lgr->smcd))
1274 			smcd_buf_detach(conn);
1275 		tasklet_kill(&conn->rx_tsklet);
1276 	} else {
1277 		smc_cdc_wait_pend_tx_wr(conn);
1278 		if (current_work() != &conn->abort_work)
1279 			cancel_work_sync(&conn->abort_work);
1280 	}
1281 	if (!list_empty(&lgr->list)) {
1282 		smc_buf_unuse(conn, lgr); /* allow buffer reuse */
1283 		smc_lgr_unregister_conn(conn);
1284 	}
1285 
1286 	if (!lgr->conns_num)
1287 		smc_lgr_schedule_free_work(lgr);
1288 lgr_put:
1289 	if (!lgr->is_smcd)
1290 		smcr_link_put(conn->lnk); /* link_hold in smc_conn_create() */
1291 	smc_lgr_put(lgr); /* lgr_hold in smc_conn_create() */
1292 }
1293 
1294 /* unregister a link from a buf_desc */
1295 static void smcr_buf_unmap_link(struct smc_buf_desc *buf_desc, bool is_rmb,
1296 				struct smc_link *lnk)
1297 {
1298 	if (is_rmb || buf_desc->is_vm)
1299 		buf_desc->is_reg_mr[lnk->link_idx] = false;
1300 	if (!buf_desc->is_map_ib[lnk->link_idx])
1301 		return;
1302 
1303 	if ((is_rmb || buf_desc->is_vm) &&
1304 	    buf_desc->mr[lnk->link_idx]) {
1305 		smc_ib_put_memory_region(buf_desc->mr[lnk->link_idx]);
1306 		buf_desc->mr[lnk->link_idx] = NULL;
1307 	}
1308 	if (is_rmb)
1309 		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_FROM_DEVICE);
1310 	else
1311 		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_TO_DEVICE);
1312 
1313 	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
1314 	buf_desc->is_map_ib[lnk->link_idx] = false;
1315 }
1316 
1317 /* unmap all buffers of lgr for a deleted link */
1318 static void smcr_buf_unmap_lgr(struct smc_link *lnk)
1319 {
1320 	struct smc_link_group *lgr = lnk->lgr;
1321 	struct smc_buf_desc *buf_desc, *bf;
1322 	int i;
1323 
1324 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1325 		down_write(&lgr->rmbs_lock);
1326 		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list)
1327 			smcr_buf_unmap_link(buf_desc, true, lnk);
1328 		up_write(&lgr->rmbs_lock);
1329 
1330 		down_write(&lgr->sndbufs_lock);
1331 		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i],
1332 					 list)
1333 			smcr_buf_unmap_link(buf_desc, false, lnk);
1334 		up_write(&lgr->sndbufs_lock);
1335 	}
1336 }
1337 
1338 static void smcr_rtoken_clear_link(struct smc_link *lnk)
1339 {
1340 	struct smc_link_group *lgr = lnk->lgr;
1341 	int i;
1342 
1343 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1344 		lgr->rtokens[i][lnk->link_idx].rkey = 0;
1345 		lgr->rtokens[i][lnk->link_idx].dma_addr = 0;
1346 	}
1347 }
1348 
1349 static void __smcr_link_clear(struct smc_link *lnk)
1350 {
1351 	struct smc_link_group *lgr = lnk->lgr;
1352 	struct smc_ib_device *smcibdev;
1353 
1354 	smc_wr_free_link_mem(lnk);
1355 	smc_ibdev_cnt_dec(lnk);
1356 	put_device(&lnk->smcibdev->ibdev->dev);
1357 	smcibdev = lnk->smcibdev;
1358 	memset(lnk, 0, sizeof(struct smc_link));
1359 	lnk->state = SMC_LNK_UNUSED;
1360 	if (!atomic_dec_return(&smcibdev->lnk_cnt))
1361 		wake_up(&smcibdev->lnks_deleted);
1362 	smc_lgr_put(lgr); /* lgr_hold in smcr_link_init() */
1363 }
1364 
1365 /* must be called under lgr->llc_conf_mutex lock */
1366 void smcr_link_clear(struct smc_link *lnk, bool log)
1367 {
1368 	if (!lnk->lgr || lnk->clearing ||
1369 	    lnk->state == SMC_LNK_UNUSED)
1370 		return;
1371 	lnk->clearing = 1;
1372 	lnk->peer_qpn = 0;
1373 	smc_llc_link_clear(lnk, log);
1374 	smcr_buf_unmap_lgr(lnk);
1375 	smcr_rtoken_clear_link(lnk);
1376 	smc_ib_modify_qp_error(lnk);
1377 	smc_wr_free_link(lnk);
1378 	smc_ib_destroy_queue_pair(lnk);
1379 	smc_ib_dealloc_protection_domain(lnk);
1380 	smcr_link_put(lnk); /* theoretically last link_put */
1381 }
1382 
1383 void smcr_link_hold(struct smc_link *lnk)
1384 {
1385 	refcount_inc(&lnk->refcnt);
1386 }
1387 
1388 void smcr_link_put(struct smc_link *lnk)
1389 {
1390 	if (refcount_dec_and_test(&lnk->refcnt))
1391 		__smcr_link_clear(lnk);
1392 }
1393 
1394 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
1395 			  struct smc_buf_desc *buf_desc)
1396 {
1397 	int i;
1398 
1399 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1400 		smcr_buf_unmap_link(buf_desc, is_rmb, &lgr->lnk[i]);
1401 
1402 	if (!buf_desc->is_vm && buf_desc->pages)
1403 		__free_pages(buf_desc->pages, buf_desc->order);
1404 	else if (buf_desc->is_vm && buf_desc->cpu_addr)
1405 		vfree(buf_desc->cpu_addr);
1406 	kfree(buf_desc);
1407 }
1408 
1409 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
1410 			  struct smc_buf_desc *buf_desc)
1411 {
1412 	if (is_dmb) {
1413 		/* restore original buf len */
1414 		buf_desc->len += sizeof(struct smcd_cdc_msg);
1415 		smc_ism_unregister_dmb(lgr->smcd, buf_desc);
1416 	} else {
1417 		kfree(buf_desc->cpu_addr);
1418 	}
1419 	kfree(buf_desc);
1420 }
1421 
1422 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
1423 			 struct smc_buf_desc *buf_desc)
1424 {
1425 	if (lgr->is_smcd)
1426 		smcd_buf_free(lgr, is_rmb, buf_desc);
1427 	else
1428 		smcr_buf_free(lgr, is_rmb, buf_desc);
1429 }
1430 
1431 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
1432 {
1433 	struct smc_buf_desc *buf_desc, *bf_desc;
1434 	struct list_head *buf_list;
1435 	int i;
1436 
1437 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1438 		if (is_rmb)
1439 			buf_list = &lgr->rmbs[i];
1440 		else
1441 			buf_list = &lgr->sndbufs[i];
1442 		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
1443 					 list) {
1444 			smc_lgr_buf_list_del(lgr, is_rmb, buf_desc);
1445 			smc_buf_free(lgr, is_rmb, buf_desc);
1446 		}
1447 	}
1448 }
1449 
1450 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
1451 {
1452 	/* free send buffers */
1453 	__smc_lgr_free_bufs(lgr, false);
1454 	/* free rmbs */
1455 	__smc_lgr_free_bufs(lgr, true);
1456 }
1457 
1458 /* won't be freed until no one accesses to lgr anymore */
1459 static void __smc_lgr_free(struct smc_link_group *lgr)
1460 {
1461 	smc_lgr_free_bufs(lgr);
1462 	if (lgr->is_smcd) {
1463 		if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
1464 			wake_up(&lgr->smcd->lgrs_deleted);
1465 	} else {
1466 		smc_wr_free_lgr_mem(lgr);
1467 		if (!atomic_dec_return(&lgr_cnt))
1468 			wake_up(&lgrs_deleted);
1469 	}
1470 	kfree(lgr);
1471 }
1472 
1473 /* remove a link group */
1474 static void smc_lgr_free(struct smc_link_group *lgr)
1475 {
1476 	int i;
1477 
1478 	if (!lgr->is_smcd) {
1479 		down_write(&lgr->llc_conf_mutex);
1480 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1481 			if (lgr->lnk[i].state != SMC_LNK_UNUSED)
1482 				smcr_link_clear(&lgr->lnk[i], false);
1483 		}
1484 		up_write(&lgr->llc_conf_mutex);
1485 		smc_llc_lgr_clear(lgr);
1486 	}
1487 
1488 	destroy_workqueue(lgr->tx_wq);
1489 	if (lgr->is_smcd) {
1490 		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
1491 		put_device(&lgr->smcd->dibs->dev);
1492 	}
1493 	smc_lgr_put(lgr); /* theoretically last lgr_put */
1494 }
1495 
1496 void smc_lgr_hold(struct smc_link_group *lgr)
1497 {
1498 	refcount_inc(&lgr->refcnt);
1499 }
1500 
1501 void smc_lgr_put(struct smc_link_group *lgr)
1502 {
1503 	if (refcount_dec_and_test(&lgr->refcnt))
1504 		__smc_lgr_free(lgr);
1505 }
1506 
1507 static void smc_sk_wake_ups(struct smc_sock *smc)
1508 {
1509 	smc->sk.sk_write_space(&smc->sk);
1510 	smc->sk.sk_data_ready(&smc->sk);
1511 	smc->sk.sk_state_change(&smc->sk);
1512 }
1513 
1514 /* kill a connection */
1515 static void smc_conn_kill(struct smc_connection *conn, bool soft)
1516 {
1517 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1518 
1519 	if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
1520 		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
1521 	else
1522 		smc_close_abort(conn);
1523 	conn->killed = 1;
1524 	smc->sk.sk_err = ECONNABORTED;
1525 	smc_sk_wake_ups(smc);
1526 	if (conn->lgr->is_smcd) {
1527 		smc_ism_unset_conn(conn);
1528 		if (smc_ism_support_dmb_nocopy(conn->lgr->smcd))
1529 			smcd_buf_detach(conn);
1530 		if (soft)
1531 			tasklet_kill(&conn->rx_tsklet);
1532 		else
1533 			tasklet_unlock_wait(&conn->rx_tsklet);
1534 	} else {
1535 		smc_cdc_wait_pend_tx_wr(conn);
1536 	}
1537 	smc_lgr_unregister_conn(conn);
1538 	smc_close_active_abort(smc);
1539 }
1540 
1541 static void smc_lgr_cleanup(struct smc_link_group *lgr)
1542 {
1543 	if (lgr->is_smcd) {
1544 		smc_ism_signal_shutdown(lgr);
1545 	} else {
1546 		u32 rsn = lgr->llc_termination_rsn;
1547 
1548 		if (!rsn)
1549 			rsn = SMC_LLC_DEL_PROG_INIT_TERM;
1550 		smc_llc_send_link_delete_all(lgr, false, rsn);
1551 		smcr_lgr_link_deactivate_all(lgr);
1552 	}
1553 }
1554 
1555 /* terminate link group
1556  * @soft: true if link group shutdown can take its time
1557  *	  false if immediate link group shutdown is required
1558  */
1559 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
1560 {
1561 	struct smc_connection *conn;
1562 	struct smc_sock *smc;
1563 	struct rb_node *node;
1564 
1565 	if (lgr->terminating)
1566 		return;	/* lgr already terminating */
1567 	/* cancel free_work sync, will terminate when lgr->freeing is set */
1568 	cancel_delayed_work(&lgr->free_work);
1569 	lgr->terminating = 1;
1570 
1571 	/* kill remaining link group connections */
1572 	read_lock_bh(&lgr->conns_lock);
1573 	node = rb_first(&lgr->conns_all);
1574 	while (node) {
1575 		read_unlock_bh(&lgr->conns_lock);
1576 		conn = rb_entry(node, struct smc_connection, alert_node);
1577 		smc = container_of(conn, struct smc_sock, conn);
1578 		sock_hold(&smc->sk); /* sock_put below */
1579 		lock_sock(&smc->sk);
1580 		smc_conn_kill(conn, soft);
1581 		release_sock(&smc->sk);
1582 		sock_put(&smc->sk); /* sock_hold above */
1583 		read_lock_bh(&lgr->conns_lock);
1584 		node = rb_first(&lgr->conns_all);
1585 	}
1586 	read_unlock_bh(&lgr->conns_lock);
1587 	smc_lgr_cleanup(lgr);
1588 	smc_lgr_free(lgr);
1589 }
1590 
1591 /* unlink link group and schedule termination */
1592 void smc_lgr_terminate_sched(struct smc_link_group *lgr)
1593 {
1594 	spinlock_t *lgr_lock;
1595 
1596 	smc_lgr_list_head(lgr, &lgr_lock);
1597 	spin_lock_bh(lgr_lock);
1598 	if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
1599 		spin_unlock_bh(lgr_lock);
1600 		return;	/* lgr already terminating */
1601 	}
1602 	list_del_init(&lgr->list);
1603 	lgr->freeing = 1;
1604 	spin_unlock_bh(lgr_lock);
1605 	schedule_work(&lgr->terminate_work);
1606 }
1607 
1608 /* Called when peer lgr shutdown (regularly or abnormally) is received */
1609 void smc_smcd_terminate(struct smcd_dev *dev, struct smcd_gid *peer_gid,
1610 			unsigned short vlan)
1611 {
1612 	struct smc_link_group *lgr, *l;
1613 	LIST_HEAD(lgr_free_list);
1614 
1615 	/* run common cleanup function and build free list */
1616 	spin_lock_bh(&dev->lgr_lock);
1617 	list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
1618 		if ((!peer_gid->gid ||
1619 		     (lgr->peer_gid.gid == peer_gid->gid &&
1620 		      !smc_ism_is_emulated(dev) ? 1 :
1621 		      lgr->peer_gid.gid_ext == peer_gid->gid_ext)) &&
1622 		    (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
1623 			if (peer_gid->gid) /* peer triggered termination */
1624 				lgr->peer_shutdown = 1;
1625 			list_move(&lgr->list, &lgr_free_list);
1626 			lgr->freeing = 1;
1627 		}
1628 	}
1629 	spin_unlock_bh(&dev->lgr_lock);
1630 
1631 	/* cancel the regular free workers and actually free lgrs */
1632 	list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
1633 		list_del_init(&lgr->list);
1634 		schedule_work(&lgr->terminate_work);
1635 	}
1636 }
1637 
1638 /* Called when an SMCD device is removed or the smc module is unloaded */
1639 void smc_smcd_terminate_all(struct smcd_dev *smcd)
1640 {
1641 	struct smc_link_group *lgr, *lg;
1642 	LIST_HEAD(lgr_free_list);
1643 
1644 	spin_lock_bh(&smcd->lgr_lock);
1645 	list_splice_init(&smcd->lgr_list, &lgr_free_list);
1646 	list_for_each_entry(lgr, &lgr_free_list, list)
1647 		lgr->freeing = 1;
1648 	spin_unlock_bh(&smcd->lgr_lock);
1649 
1650 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1651 		list_del_init(&lgr->list);
1652 		__smc_lgr_terminate(lgr, false);
1653 	}
1654 
1655 	if (atomic_read(&smcd->lgr_cnt))
1656 		wait_event(smcd->lgrs_deleted, !atomic_read(&smcd->lgr_cnt));
1657 }
1658 
1659 /* Called when an SMCR device is removed or the smc module is unloaded.
1660  * If smcibdev is given, all SMCR link groups using this device are terminated.
1661  * If smcibdev is NULL, all SMCR link groups are terminated.
1662  */
1663 void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
1664 {
1665 	struct smc_link_group *lgr, *lg;
1666 	LIST_HEAD(lgr_free_list);
1667 	int i;
1668 
1669 	spin_lock_bh(&smc_lgr_list.lock);
1670 	if (!smcibdev) {
1671 		list_splice_init(&smc_lgr_list.list, &lgr_free_list);
1672 		list_for_each_entry(lgr, &lgr_free_list, list)
1673 			lgr->freeing = 1;
1674 	} else {
1675 		list_for_each_entry_safe(lgr, lg, &smc_lgr_list.list, list) {
1676 			for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1677 				if (lgr->lnk[i].smcibdev == smcibdev)
1678 					smcr_link_down_cond_sched(&lgr->lnk[i]);
1679 			}
1680 		}
1681 	}
1682 	spin_unlock_bh(&smc_lgr_list.lock);
1683 
1684 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1685 		list_del_init(&lgr->list);
1686 		smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_OP_INIT_TERM);
1687 		__smc_lgr_terminate(lgr, false);
1688 	}
1689 
1690 	if (smcibdev) {
1691 		if (atomic_read(&smcibdev->lnk_cnt))
1692 			wait_event(smcibdev->lnks_deleted,
1693 				   !atomic_read(&smcibdev->lnk_cnt));
1694 	} else {
1695 		if (atomic_read(&lgr_cnt))
1696 			wait_event(lgrs_deleted, !atomic_read(&lgr_cnt));
1697 	}
1698 }
1699 
1700 /* set new lgr type and clear all asymmetric link tagging */
1701 void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type)
1702 {
1703 	char *lgr_type = "";
1704 	int i;
1705 
1706 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1707 		if (smc_link_usable(&lgr->lnk[i]))
1708 			lgr->lnk[i].link_is_asym = false;
1709 	if (lgr->type == new_type)
1710 		return;
1711 	lgr->type = new_type;
1712 
1713 	switch (lgr->type) {
1714 	case SMC_LGR_NONE:
1715 		lgr_type = "NONE";
1716 		break;
1717 	case SMC_LGR_SINGLE:
1718 		lgr_type = "SINGLE";
1719 		break;
1720 	case SMC_LGR_SYMMETRIC:
1721 		lgr_type = "SYMMETRIC";
1722 		break;
1723 	case SMC_LGR_ASYMMETRIC_PEER:
1724 		lgr_type = "ASYMMETRIC_PEER";
1725 		break;
1726 	case SMC_LGR_ASYMMETRIC_LOCAL:
1727 		lgr_type = "ASYMMETRIC_LOCAL";
1728 		break;
1729 	}
1730 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu state changed: "
1731 			    "%s, pnetid %.16s\n", SMC_LGR_ID_SIZE, &lgr->id,
1732 			    lgr->net->net_cookie, lgr_type, lgr->pnet_id);
1733 }
1734 
1735 /* set new lgr type and tag a link as asymmetric */
1736 void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
1737 			    enum smc_lgr_type new_type, int asym_lnk_idx)
1738 {
1739 	smcr_lgr_set_type(lgr, new_type);
1740 	lgr->lnk[asym_lnk_idx].link_is_asym = true;
1741 }
1742 
1743 /* abort connection, abort_work scheduled from tasklet context */
1744 static void smc_conn_abort_work(struct work_struct *work)
1745 {
1746 	struct smc_connection *conn = container_of(work,
1747 						   struct smc_connection,
1748 						   abort_work);
1749 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1750 
1751 	lock_sock(&smc->sk);
1752 	smc_conn_kill(conn, true);
1753 	release_sock(&smc->sk);
1754 	sock_put(&smc->sk); /* sock_hold done by schedulers of abort_work */
1755 }
1756 
1757 void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
1758 {
1759 	struct smc_link_group *lgr, *n;
1760 
1761 	spin_lock_bh(&smc_lgr_list.lock);
1762 	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1763 		struct smc_link *link;
1764 
1765 		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1766 			    SMC_MAX_PNETID_LEN) ||
1767 		    lgr->type == SMC_LGR_SYMMETRIC ||
1768 		    lgr->type == SMC_LGR_ASYMMETRIC_PEER ||
1769 		    !rdma_dev_access_netns(smcibdev->ibdev, lgr->net))
1770 			continue;
1771 
1772 		if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
1773 			continue;
1774 
1775 		/* trigger local add link processing */
1776 		link = smc_llc_usable_link(lgr);
1777 		if (link)
1778 			smc_llc_add_link_local(link);
1779 	}
1780 	spin_unlock_bh(&smc_lgr_list.lock);
1781 }
1782 
1783 /* link is down - switch connections to alternate link,
1784  * must be called under lgr->llc_conf_mutex lock
1785  */
1786 static void smcr_link_down(struct smc_link *lnk)
1787 {
1788 	struct smc_link_group *lgr = lnk->lgr;
1789 	struct smc_link *to_lnk;
1790 	int del_link_id;
1791 
1792 	if (!lgr || lnk->state == SMC_LNK_UNUSED || list_empty(&lgr->list))
1793 		return;
1794 
1795 	to_lnk = smc_switch_conns(lgr, lnk, true);
1796 	if (!to_lnk) { /* no backup link available */
1797 		smcr_link_clear(lnk, true);
1798 		return;
1799 	}
1800 	smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1801 	del_link_id = lnk->link_id;
1802 
1803 	if (lgr->role == SMC_SERV) {
1804 		/* trigger local delete link processing */
1805 		smc_llc_srv_delete_link_local(to_lnk, del_link_id);
1806 	} else {
1807 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1808 			/* another llc task is ongoing */
1809 			up_write(&lgr->llc_conf_mutex);
1810 			wait_event_timeout(lgr->llc_flow_waiter,
1811 				(list_empty(&lgr->list) ||
1812 				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
1813 				SMC_LLC_WAIT_TIME);
1814 			down_write(&lgr->llc_conf_mutex);
1815 		}
1816 		if (!list_empty(&lgr->list)) {
1817 			smc_llc_send_delete_link(to_lnk, del_link_id,
1818 						 SMC_LLC_REQ, true,
1819 						 SMC_LLC_DEL_LOST_PATH);
1820 			smcr_link_clear(lnk, true);
1821 		}
1822 		wake_up(&lgr->llc_flow_waiter);	/* wake up next waiter */
1823 	}
1824 }
1825 
1826 /* must be called under lgr->llc_conf_mutex lock */
1827 void smcr_link_down_cond(struct smc_link *lnk)
1828 {
1829 	if (smc_link_downing(&lnk->state)) {
1830 		trace_smcr_link_down(lnk, __builtin_return_address(0));
1831 		smcr_link_down(lnk);
1832 	}
1833 }
1834 
1835 /* will get the lgr->llc_conf_mutex lock */
1836 void smcr_link_down_cond_sched(struct smc_link *lnk)
1837 {
1838 	if (smc_link_downing(&lnk->state)) {
1839 		trace_smcr_link_down(lnk, __builtin_return_address(0));
1840 		smcr_link_hold(lnk); /* smcr_link_put in link_down_wrk */
1841 		if (!schedule_work(&lnk->link_down_wrk))
1842 			smcr_link_put(lnk);
1843 	}
1844 }
1845 
1846 void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport)
1847 {
1848 	struct smc_link_group *lgr, *n;
1849 	int i;
1850 
1851 	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1852 		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1853 			    SMC_MAX_PNETID_LEN))
1854 			continue; /* lgr is not affected */
1855 		if (list_empty(&lgr->list))
1856 			continue;
1857 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1858 			struct smc_link *lnk = &lgr->lnk[i];
1859 
1860 			if (smc_link_usable(lnk) &&
1861 			    lnk->smcibdev == smcibdev && lnk->ibport == ibport)
1862 				smcr_link_down_cond_sched(lnk);
1863 		}
1864 	}
1865 }
1866 
1867 static void smc_link_down_work(struct work_struct *work)
1868 {
1869 	struct smc_link *link = container_of(work, struct smc_link,
1870 					     link_down_wrk);
1871 	struct smc_link_group *lgr = link->lgr;
1872 
1873 	if (list_empty(&lgr->list))
1874 		goto out;
1875 	wake_up_all(&lgr->llc_msg_waiter);
1876 	down_write(&lgr->llc_conf_mutex);
1877 	smcr_link_down(link);
1878 	up_write(&lgr->llc_conf_mutex);
1879 
1880 out:
1881 	smcr_link_put(link); /* smcr_link_hold by schedulers of link_down_work */
1882 }
1883 
1884 static int smc_vlan_by_tcpsk_walk(struct net_device *lower_dev,
1885 				  struct netdev_nested_priv *priv)
1886 {
1887 	unsigned short *vlan_id = (unsigned short *)priv->data;
1888 
1889 	if (is_vlan_dev(lower_dev)) {
1890 		*vlan_id = vlan_dev_vlan_id(lower_dev);
1891 		return 1;
1892 	}
1893 
1894 	return 0;
1895 }
1896 
1897 /* Determine vlan of internal TCP socket. */
1898 int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
1899 {
1900 	struct netdev_nested_priv priv;
1901 	struct net_device *ndev;
1902 	struct dst_entry *dst;
1903 	int rc = 0;
1904 
1905 	ini->vlan_id = 0;
1906 
1907 	rcu_read_lock();
1908 
1909 	dst = __sk_dst_get(clcsock->sk);
1910 	ndev = dst ? dst_dev_rcu(dst) : NULL;
1911 	if (!ndev) {
1912 		rc = -ENODEV;
1913 		goto out;
1914 	}
1915 
1916 	if (is_vlan_dev(ndev)) {
1917 		ini->vlan_id = vlan_dev_vlan_id(ndev);
1918 		goto out;
1919 	}
1920 
1921 	priv.data = (void *)&ini->vlan_id;
1922 	netdev_walk_all_lower_dev_rcu(ndev, smc_vlan_by_tcpsk_walk, &priv);
1923 out:
1924 	rcu_read_unlock();
1925 
1926 	return rc;
1927 }
1928 
1929 static bool smcr_lgr_match(struct smc_link_group *lgr, u8 smcr_version,
1930 			   u8 peer_systemid[],
1931 			   u8 peer_gid[],
1932 			   u8 peer_mac_v1[],
1933 			   enum smc_lgr_role role, u32 clcqpn,
1934 			   struct net *net)
1935 {
1936 	struct smc_link *lnk;
1937 	int i;
1938 
1939 	if (memcmp(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN) ||
1940 	    lgr->role != role)
1941 		return false;
1942 
1943 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1944 		lnk = &lgr->lnk[i];
1945 
1946 		if (!smc_link_active(lnk))
1947 			continue;
1948 		/* use verbs API to check netns, instead of lgr->net */
1949 		if (!rdma_dev_access_netns(lnk->smcibdev->ibdev, net))
1950 			return false;
1951 		if ((lgr->role == SMC_SERV || lnk->peer_qpn == clcqpn) &&
1952 		    !memcmp(lnk->peer_gid, peer_gid, SMC_GID_SIZE) &&
1953 		    (smcr_version == SMC_V2 ||
1954 		     !memcmp(lnk->peer_mac, peer_mac_v1, ETH_ALEN)))
1955 			return true;
1956 	}
1957 	return false;
1958 }
1959 
1960 static bool smcd_lgr_match(struct smc_link_group *lgr,
1961 			   struct smcd_dev *smcismdev,
1962 			   struct smcd_gid *peer_gid)
1963 {
1964 	if (lgr->peer_gid.gid != peer_gid->gid ||
1965 	    lgr->smcd != smcismdev)
1966 		return false;
1967 
1968 	if (smc_ism_is_emulated(smcismdev) &&
1969 	    lgr->peer_gid.gid_ext != peer_gid->gid_ext)
1970 		return false;
1971 
1972 	return true;
1973 }
1974 
1975 /* create a new SMC connection (and a new link group if necessary) */
1976 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
1977 {
1978 	struct smc_connection *conn = &smc->conn;
1979 	struct net *net = sock_net(&smc->sk);
1980 	struct list_head *lgr_list;
1981 	struct smc_link_group *lgr;
1982 	enum smc_lgr_role role;
1983 	spinlock_t *lgr_lock;
1984 	int rc = 0;
1985 
1986 	lgr_list = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_list :
1987 				  &smc_lgr_list.list;
1988 	lgr_lock = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_lock :
1989 				  &smc_lgr_list.lock;
1990 	ini->first_contact_local = 1;
1991 	role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
1992 	if (role == SMC_CLNT && ini->first_contact_peer)
1993 		/* create new link group as well */
1994 		goto create;
1995 
1996 	/* determine if an existing link group can be reused */
1997 	spin_lock_bh(lgr_lock);
1998 	list_for_each_entry(lgr, lgr_list, list) {
1999 		write_lock_bh(&lgr->conns_lock);
2000 		if ((ini->is_smcd ?
2001 		     smcd_lgr_match(lgr, ini->ism_dev[ini->ism_selected],
2002 				    &ini->ism_peer_gid[ini->ism_selected]) :
2003 		     smcr_lgr_match(lgr, ini->smcr_version,
2004 				    ini->peer_systemid,
2005 				    ini->peer_gid, ini->peer_mac, role,
2006 				    ini->ib_clcqpn, net)) &&
2007 		    !lgr->sync_err &&
2008 		    (ini->smcd_version == SMC_V2 ||
2009 		     lgr->vlan_id == ini->vlan_id) &&
2010 		    (role == SMC_CLNT || ini->is_smcd ||
2011 		    (lgr->conns_num < lgr->max_conns &&
2012 		      !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) {
2013 			/* link group found */
2014 			ini->first_contact_local = 0;
2015 			conn->lgr = lgr;
2016 			rc = smc_lgr_register_conn(conn, false);
2017 			write_unlock_bh(&lgr->conns_lock);
2018 			if (!rc && delayed_work_pending(&lgr->free_work))
2019 				cancel_delayed_work(&lgr->free_work);
2020 			break;
2021 		}
2022 		write_unlock_bh(&lgr->conns_lock);
2023 	}
2024 	spin_unlock_bh(lgr_lock);
2025 	if (rc)
2026 		return rc;
2027 
2028 	if (role == SMC_CLNT && !ini->first_contact_peer &&
2029 	    ini->first_contact_local) {
2030 		/* Server reuses a link group, but Client wants to start
2031 		 * a new one
2032 		 * send out_of_sync decline, reason synchr. error
2033 		 */
2034 		return SMC_CLC_DECL_SYNCERR;
2035 	}
2036 
2037 create:
2038 	if (ini->first_contact_local) {
2039 		rc = smc_lgr_create(smc, ini);
2040 		if (rc)
2041 			goto out;
2042 		lgr = conn->lgr;
2043 		write_lock_bh(&lgr->conns_lock);
2044 		rc = smc_lgr_register_conn(conn, true);
2045 		write_unlock_bh(&lgr->conns_lock);
2046 		if (rc) {
2047 			smc_lgr_cleanup_early(lgr);
2048 			goto out;
2049 		}
2050 	}
2051 	smc_lgr_hold(conn->lgr); /* lgr_put in smc_conn_free() */
2052 	if (!conn->lgr->is_smcd)
2053 		smcr_link_hold(conn->lnk); /* link_put in smc_conn_free() */
2054 	conn->freed = 0;
2055 	conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
2056 	conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
2057 	conn->urg_state = SMC_URG_READ;
2058 	init_waitqueue_head(&conn->cdc_pend_tx_wq);
2059 	INIT_WORK(&smc->conn.abort_work, smc_conn_abort_work);
2060 	if (ini->is_smcd) {
2061 		conn->rx_off = sizeof(struct smcd_cdc_msg);
2062 		smcd_cdc_rx_init(conn); /* init tasklet for this conn */
2063 	} else {
2064 		conn->rx_off = 0;
2065 	}
2066 #ifndef KERNEL_HAS_ATOMIC64
2067 	spin_lock_init(&conn->acurs_lock);
2068 #endif
2069 
2070 out:
2071 	return rc;
2072 }
2073 
2074 #define SMCD_DMBE_SIZES		6 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
2075 #define SMCR_RMBE_SIZES		15 /* 0 -> 16KB, 1 -> 32KB, .. 15 -> 512MB */
2076 
2077 /* convert the RMB size into the compressed notation (minimum 16K, see
2078  * SMCD/R_DMBE_SIZES.
2079  * In contrast to plain ilog2, this rounds towards the next power of 2,
2080  * so the socket application gets at least its desired sndbuf / rcvbuf size.
2081  */
2082 static u8 smc_compress_bufsize(int size, bool is_smcd, bool is_rmb)
2083 {
2084 	u8 compressed;
2085 
2086 	if (size <= SMC_BUF_MIN_SIZE)
2087 		return 0;
2088 
2089 	size = (size - 1) >> 14;  /* convert to 16K multiple */
2090 	compressed = min_t(u8, ilog2(size) + 1,
2091 			   is_smcd ? SMCD_DMBE_SIZES : SMCR_RMBE_SIZES);
2092 
2093 #ifdef CONFIG_ARCH_NO_SG_CHAIN
2094 	if (!is_smcd && is_rmb)
2095 		/* RMBs are backed by & limited to max size of scatterlists */
2096 		compressed = min_t(u8, compressed, ilog2((SG_MAX_SINGLE_ALLOC * PAGE_SIZE) >> 14));
2097 #endif
2098 
2099 	return compressed;
2100 }
2101 
2102 /* convert the RMB size from compressed notation into integer */
2103 int smc_uncompress_bufsize(u8 compressed)
2104 {
2105 	u32 size;
2106 
2107 	size = 0x00000001 << (((int)compressed) + 14);
2108 	return (int)size;
2109 }
2110 
2111 /* try to reuse a sndbuf or rmb description slot for a certain
2112  * buffer size; if not available, return NULL
2113  */
2114 static struct smc_buf_desc *smc_buf_get_slot(struct rw_semaphore *lock,
2115 					     struct list_head *buf_list)
2116 {
2117 	struct smc_buf_desc *buf_slot;
2118 
2119 	down_read(lock);
2120 	list_for_each_entry(buf_slot, buf_list, list) {
2121 		if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
2122 			up_read(lock);
2123 			return buf_slot;
2124 		}
2125 	}
2126 	up_read(lock);
2127 	return NULL;
2128 }
2129 
2130 /* one of the conditions for announcing a receiver's current window size is
2131  * that it "results in a minimum increase in the window size of 10% of the
2132  * receive buffer space" [RFC7609]
2133  */
2134 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
2135 {
2136 	return max_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
2137 }
2138 
2139 /* map an buf to a link */
2140 static int smcr_buf_map_link(struct smc_buf_desc *buf_desc, bool is_rmb,
2141 			     struct smc_link *lnk)
2142 {
2143 	int rc, i, nents, offset, buf_size, size, access_flags;
2144 	struct scatterlist *sg;
2145 	void *buf;
2146 
2147 	if (buf_desc->is_map_ib[lnk->link_idx])
2148 		return 0;
2149 
2150 	if (buf_desc->is_vm) {
2151 		buf = buf_desc->cpu_addr;
2152 		buf_size = buf_desc->len;
2153 		offset = offset_in_page(buf_desc->cpu_addr);
2154 		nents = PAGE_ALIGN(buf_size + offset) / PAGE_SIZE;
2155 	} else {
2156 		nents = 1;
2157 	}
2158 
2159 	rc = sg_alloc_table(&buf_desc->sgt[lnk->link_idx], nents, GFP_KERNEL);
2160 	if (rc)
2161 		return rc;
2162 
2163 	if (buf_desc->is_vm) {
2164 		/* virtually contiguous buffer */
2165 		for_each_sg(buf_desc->sgt[lnk->link_idx].sgl, sg, nents, i) {
2166 			size = min_t(int, PAGE_SIZE - offset, buf_size);
2167 			sg_set_page(sg, vmalloc_to_page(buf), size, offset);
2168 			buf += size;
2169 			buf_size -= size;
2170 			offset = 0;
2171 		}
2172 	} else {
2173 		/* physically contiguous buffer */
2174 		sg_set_buf(buf_desc->sgt[lnk->link_idx].sgl,
2175 			   buf_desc->cpu_addr, buf_desc->len);
2176 	}
2177 
2178 	/* map sg table to DMA address */
2179 	rc = smc_ib_buf_map_sg(lnk, buf_desc,
2180 			       is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2181 	/* SMC protocol depends on mapping to one DMA address only */
2182 	if (rc != nents) {
2183 		rc = -EAGAIN;
2184 		goto free_table;
2185 	}
2186 
2187 	buf_desc->is_dma_need_sync |=
2188 		smc_ib_is_sg_need_sync(lnk, buf_desc) << lnk->link_idx;
2189 
2190 	if (is_rmb || buf_desc->is_vm) {
2191 		/* create a new memory region for the RMB or vzalloced sndbuf */
2192 		access_flags = is_rmb ?
2193 			       IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
2194 			       IB_ACCESS_LOCAL_WRITE;
2195 
2196 		rc = smc_ib_get_memory_region(lnk->roce_pd, access_flags,
2197 					      buf_desc, lnk->link_idx);
2198 		if (rc)
2199 			goto buf_unmap;
2200 		smc_ib_sync_sg_for_device(lnk, buf_desc,
2201 					  is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2202 	}
2203 	buf_desc->is_map_ib[lnk->link_idx] = true;
2204 	return 0;
2205 
2206 buf_unmap:
2207 	smc_ib_buf_unmap_sg(lnk, buf_desc,
2208 			    is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2209 free_table:
2210 	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
2211 	return rc;
2212 }
2213 
2214 /* register a new buf on IB device, rmb or vzalloced sndbuf
2215  * must be called under lgr->llc_conf_mutex lock
2216  */
2217 int smcr_link_reg_buf(struct smc_link *link, struct smc_buf_desc *buf_desc)
2218 {
2219 	if (list_empty(&link->lgr->list))
2220 		return -ENOLINK;
2221 	if (!buf_desc->is_reg_mr[link->link_idx]) {
2222 		/* register memory region for new buf */
2223 		if (buf_desc->is_vm)
2224 			buf_desc->mr[link->link_idx]->iova =
2225 				(uintptr_t)buf_desc->cpu_addr;
2226 		if (smc_wr_reg_send(link, buf_desc->mr[link->link_idx])) {
2227 			buf_desc->is_reg_err = true;
2228 			return -EFAULT;
2229 		}
2230 		buf_desc->is_reg_mr[link->link_idx] = true;
2231 	}
2232 	return 0;
2233 }
2234 
2235 static int _smcr_buf_map_lgr(struct smc_link *lnk, struct rw_semaphore *lock,
2236 			     struct list_head *lst, bool is_rmb)
2237 {
2238 	struct smc_buf_desc *buf_desc, *bf;
2239 	int rc = 0;
2240 
2241 	down_write(lock);
2242 	list_for_each_entry_safe(buf_desc, bf, lst, list) {
2243 		if (!buf_desc->used)
2244 			continue;
2245 		rc = smcr_buf_map_link(buf_desc, is_rmb, lnk);
2246 		if (rc)
2247 			goto out;
2248 	}
2249 out:
2250 	up_write(lock);
2251 	return rc;
2252 }
2253 
2254 /* map all used buffers of lgr for a new link */
2255 int smcr_buf_map_lgr(struct smc_link *lnk)
2256 {
2257 	struct smc_link_group *lgr = lnk->lgr;
2258 	int i, rc = 0;
2259 
2260 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2261 		rc = _smcr_buf_map_lgr(lnk, &lgr->rmbs_lock,
2262 				       &lgr->rmbs[i], true);
2263 		if (rc)
2264 			return rc;
2265 		rc = _smcr_buf_map_lgr(lnk, &lgr->sndbufs_lock,
2266 				       &lgr->sndbufs[i], false);
2267 		if (rc)
2268 			return rc;
2269 	}
2270 	return 0;
2271 }
2272 
2273 /* register all used buffers of lgr for a new link,
2274  * must be called under lgr->llc_conf_mutex lock
2275  */
2276 int smcr_buf_reg_lgr(struct smc_link *lnk)
2277 {
2278 	struct smc_link_group *lgr = lnk->lgr;
2279 	struct smc_buf_desc *buf_desc, *bf;
2280 	int i, rc = 0;
2281 
2282 	/* reg all RMBs for a new link */
2283 	down_write(&lgr->rmbs_lock);
2284 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2285 		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list) {
2286 			if (!buf_desc->used)
2287 				continue;
2288 			rc = smcr_link_reg_buf(lnk, buf_desc);
2289 			if (rc) {
2290 				up_write(&lgr->rmbs_lock);
2291 				return rc;
2292 			}
2293 		}
2294 	}
2295 	up_write(&lgr->rmbs_lock);
2296 
2297 	if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2298 		return rc;
2299 
2300 	/* reg all vzalloced sndbufs for a new link */
2301 	down_write(&lgr->sndbufs_lock);
2302 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2303 		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i], list) {
2304 			if (!buf_desc->used || !buf_desc->is_vm)
2305 				continue;
2306 			rc = smcr_link_reg_buf(lnk, buf_desc);
2307 			if (rc) {
2308 				up_write(&lgr->sndbufs_lock);
2309 				return rc;
2310 			}
2311 		}
2312 	}
2313 	up_write(&lgr->sndbufs_lock);
2314 	return rc;
2315 }
2316 
2317 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
2318 						int bufsize)
2319 {
2320 	struct smc_buf_desc *buf_desc;
2321 
2322 	/* try to alloc a new buffer */
2323 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2324 	if (!buf_desc)
2325 		return ERR_PTR(-ENOMEM);
2326 
2327 	switch (lgr->buf_type) {
2328 	case SMCR_PHYS_CONT_BUFS:
2329 	case SMCR_MIXED_BUFS:
2330 		buf_desc->order = get_order(bufsize);
2331 		buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
2332 					      __GFP_NOMEMALLOC | __GFP_COMP |
2333 					      __GFP_NORETRY | __GFP_ZERO,
2334 					      buf_desc->order);
2335 		if (buf_desc->pages) {
2336 			buf_desc->cpu_addr =
2337 				(void *)page_address(buf_desc->pages);
2338 			buf_desc->len = bufsize;
2339 			buf_desc->is_vm = false;
2340 			break;
2341 		}
2342 		if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2343 			goto out;
2344 		fallthrough;	// try virtually contiguous buf
2345 	case SMCR_VIRT_CONT_BUFS:
2346 		buf_desc->order = get_order(bufsize);
2347 		buf_desc->cpu_addr = vzalloc(PAGE_SIZE << buf_desc->order);
2348 		if (!buf_desc->cpu_addr)
2349 			goto out;
2350 		buf_desc->pages = NULL;
2351 		buf_desc->len = bufsize;
2352 		buf_desc->is_vm = true;
2353 		break;
2354 	}
2355 	return buf_desc;
2356 
2357 out:
2358 	kfree(buf_desc);
2359 	return ERR_PTR(-EAGAIN);
2360 }
2361 
2362 /* map buf_desc on all usable links,
2363  * unused buffers stay mapped as long as the link is up
2364  */
2365 static int smcr_buf_map_usable_links(struct smc_link_group *lgr,
2366 				     struct smc_buf_desc *buf_desc, bool is_rmb)
2367 {
2368 	int i, rc = 0, cnt = 0;
2369 
2370 	/* protect against parallel link reconfiguration */
2371 	down_read(&lgr->llc_conf_mutex);
2372 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2373 		struct smc_link *lnk = &lgr->lnk[i];
2374 
2375 		if (!smc_link_usable(lnk))
2376 			continue;
2377 		if (smcr_buf_map_link(buf_desc, is_rmb, lnk)) {
2378 			rc = -ENOMEM;
2379 			goto out;
2380 		}
2381 		cnt++;
2382 	}
2383 out:
2384 	up_read(&lgr->llc_conf_mutex);
2385 	if (!rc && !cnt)
2386 		rc = -EINVAL;
2387 	return rc;
2388 }
2389 
2390 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
2391 						bool is_dmb, int bufsize)
2392 {
2393 	struct smc_buf_desc *buf_desc;
2394 	int rc;
2395 
2396 	/* try to alloc a new DMB */
2397 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2398 	if (!buf_desc)
2399 		return ERR_PTR(-ENOMEM);
2400 	if (is_dmb) {
2401 		rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
2402 		if (rc) {
2403 			kfree(buf_desc);
2404 			if (rc == -ENOMEM)
2405 				return ERR_PTR(-EAGAIN);
2406 			if (rc == -ENOSPC)
2407 				return ERR_PTR(-ENOSPC);
2408 			return ERR_PTR(-EIO);
2409 		}
2410 		buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
2411 		/* CDC header stored in buf. So, pretend it was smaller */
2412 		buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
2413 	} else {
2414 		buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
2415 					     __GFP_NOWARN | __GFP_NORETRY |
2416 					     __GFP_NOMEMALLOC);
2417 		if (!buf_desc->cpu_addr) {
2418 			kfree(buf_desc);
2419 			return ERR_PTR(-EAGAIN);
2420 		}
2421 		buf_desc->len = bufsize;
2422 	}
2423 	return buf_desc;
2424 }
2425 
2426 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
2427 {
2428 	struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
2429 	struct smc_connection *conn = &smc->conn;
2430 	struct smc_link_group *lgr = conn->lgr;
2431 	struct list_head *buf_list;
2432 	int bufsize, bufsize_comp;
2433 	struct rw_semaphore *lock;	/* lock buffer list */
2434 	bool is_dgraded = false;
2435 
2436 	if (is_rmb)
2437 		/* use socket recv buffer size (w/o overhead) as start value */
2438 		bufsize = smc->sk.sk_rcvbuf / 2;
2439 	else
2440 		/* use socket send buffer size (w/o overhead) as start value */
2441 		bufsize = smc->sk.sk_sndbuf / 2;
2442 
2443 	for (bufsize_comp = smc_compress_bufsize(bufsize, is_smcd, is_rmb);
2444 	     bufsize_comp >= 0; bufsize_comp--) {
2445 		if (is_rmb) {
2446 			lock = &lgr->rmbs_lock;
2447 			buf_list = &lgr->rmbs[bufsize_comp];
2448 		} else {
2449 			lock = &lgr->sndbufs_lock;
2450 			buf_list = &lgr->sndbufs[bufsize_comp];
2451 		}
2452 		bufsize = smc_uncompress_bufsize(bufsize_comp);
2453 
2454 		/* check for reusable slot in the link group */
2455 		buf_desc = smc_buf_get_slot(lock, buf_list);
2456 		if (buf_desc) {
2457 			buf_desc->is_dma_need_sync = 0;
2458 			SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, true, bufsize);
2459 			SMC_STAT_BUF_REUSE(smc, is_smcd, is_rmb);
2460 			break; /* found reusable slot */
2461 		}
2462 
2463 		if (is_smcd)
2464 			buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
2465 		else
2466 			buf_desc = smcr_new_buf_create(lgr, bufsize);
2467 
2468 		if (PTR_ERR(buf_desc) == -ENOMEM)
2469 			break;
2470 		if (IS_ERR(buf_desc)) {
2471 			if (!is_dgraded) {
2472 				is_dgraded = true;
2473 				SMC_STAT_RMB_DOWNGRADED(smc, is_smcd, is_rmb);
2474 			}
2475 			continue;
2476 		}
2477 
2478 		SMC_STAT_RMB_ALLOC(smc, is_smcd, is_rmb);
2479 		SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, true, bufsize);
2480 		buf_desc->used = 1;
2481 		down_write(lock);
2482 		smc_lgr_buf_list_add(lgr, is_rmb, buf_list, buf_desc);
2483 		up_write(lock);
2484 		break; /* found */
2485 	}
2486 
2487 	if (IS_ERR(buf_desc))
2488 		return PTR_ERR(buf_desc);
2489 
2490 	if (!is_smcd) {
2491 		if (smcr_buf_map_usable_links(lgr, buf_desc, is_rmb)) {
2492 			smcr_buf_unuse(buf_desc, is_rmb, lgr);
2493 			return -ENOMEM;
2494 		}
2495 	}
2496 
2497 	if (is_rmb) {
2498 		conn->rmb_desc = buf_desc;
2499 		conn->rmbe_size_comp = bufsize_comp;
2500 		smc->sk.sk_rcvbuf = bufsize * 2;
2501 		atomic_set(&conn->bytes_to_rcv, 0);
2502 		conn->rmbe_update_limit =
2503 			smc_rmb_wnd_update_limit(buf_desc->len);
2504 		if (is_smcd)
2505 			smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
2506 	} else {
2507 		conn->sndbuf_desc = buf_desc;
2508 		smc->sk.sk_sndbuf = bufsize * 2;
2509 		atomic_set(&conn->sndbuf_space, bufsize);
2510 	}
2511 	return 0;
2512 }
2513 
2514 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
2515 {
2516 	if (!conn->sndbuf_desc->is_dma_need_sync)
2517 		return;
2518 	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd ||
2519 	    !smc_link_active(conn->lnk))
2520 		return;
2521 	smc_ib_sync_sg_for_device(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);
2522 }
2523 
2524 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
2525 {
2526 	int i;
2527 
2528 	if (!conn->rmb_desc->is_dma_need_sync)
2529 		return;
2530 	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd)
2531 		return;
2532 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2533 		if (!smc_link_active(&conn->lgr->lnk[i]))
2534 			continue;
2535 		smc_ib_sync_sg_for_cpu(&conn->lgr->lnk[i], conn->rmb_desc,
2536 				       DMA_FROM_DEVICE);
2537 	}
2538 }
2539 
2540 /* create the send and receive buffer for an SMC socket;
2541  * receive buffers are called RMBs;
2542  * (even though the SMC protocol allows more than one RMB-element per RMB,
2543  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
2544  * extra RMB for every connection in a link group
2545  */
2546 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
2547 {
2548 	int rc;
2549 
2550 	/* create send buffer */
2551 	if (is_smcd &&
2552 	    smc_ism_support_dmb_nocopy(smc->conn.lgr->smcd))
2553 		goto create_rmb;
2554 
2555 	rc = __smc_buf_create(smc, is_smcd, false);
2556 	if (rc)
2557 		return rc;
2558 
2559 create_rmb:
2560 	/* create rmb */
2561 	rc = __smc_buf_create(smc, is_smcd, true);
2562 	if (rc && smc->conn.sndbuf_desc) {
2563 		down_write(&smc->conn.lgr->sndbufs_lock);
2564 		smc_lgr_buf_list_del(smc->conn.lgr, false,
2565 				     smc->conn.sndbuf_desc);
2566 		up_write(&smc->conn.lgr->sndbufs_lock);
2567 		smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
2568 		smc->conn.sndbuf_desc = NULL;
2569 	}
2570 	return rc;
2571 }
2572 
2573 int smcd_buf_attach(struct smc_sock *smc)
2574 {
2575 	struct smc_connection *conn = &smc->conn;
2576 	struct smcd_dev *smcd = conn->lgr->smcd;
2577 	u64 peer_token = conn->peer_token;
2578 	struct smc_buf_desc *buf_desc;
2579 	int rc;
2580 
2581 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2582 	if (!buf_desc)
2583 		return -ENOMEM;
2584 
2585 	/* The ghost sndbuf_desc describes the same memory region as
2586 	 * peer RMB. Its lifecycle is consistent with the connection's
2587 	 * and it will be freed with the connections instead of the
2588 	 * link group.
2589 	 */
2590 	rc = smc_ism_attach_dmb(smcd, peer_token, buf_desc);
2591 	if (rc)
2592 		goto free;
2593 
2594 	smc->sk.sk_sndbuf = buf_desc->len;
2595 	buf_desc->cpu_addr =
2596 		(u8 *)buf_desc->cpu_addr + sizeof(struct smcd_cdc_msg);
2597 	buf_desc->len -= sizeof(struct smcd_cdc_msg);
2598 	conn->sndbuf_desc = buf_desc;
2599 	conn->sndbuf_desc->used = 1;
2600 	atomic_set(&conn->sndbuf_space, conn->sndbuf_desc->len);
2601 	return 0;
2602 
2603 free:
2604 	kfree(buf_desc);
2605 	return rc;
2606 }
2607 
2608 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
2609 {
2610 	int i;
2611 
2612 	for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
2613 		if (!test_and_set_bit(i, lgr->rtokens_used_mask))
2614 			return i;
2615 	}
2616 	return -ENOSPC;
2617 }
2618 
2619 static int smc_rtoken_find_by_link(struct smc_link_group *lgr, int lnk_idx,
2620 				   u32 rkey)
2621 {
2622 	int i;
2623 
2624 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2625 		if (test_bit(i, lgr->rtokens_used_mask) &&
2626 		    lgr->rtokens[i][lnk_idx].rkey == rkey)
2627 			return i;
2628 	}
2629 	return -ENOENT;
2630 }
2631 
2632 /* set rtoken for a new link to an existing rmb */
2633 void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
2634 		    __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey)
2635 {
2636 	int rtok_idx;
2637 
2638 	rtok_idx = smc_rtoken_find_by_link(lgr, link_idx, ntohl(nw_rkey_known));
2639 	if (rtok_idx == -ENOENT)
2640 		return;
2641 	lgr->rtokens[rtok_idx][link_idx_new].rkey = ntohl(nw_rkey);
2642 	lgr->rtokens[rtok_idx][link_idx_new].dma_addr = be64_to_cpu(nw_vaddr);
2643 }
2644 
2645 /* set rtoken for a new link whose link_id is given */
2646 void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
2647 		     __be64 nw_vaddr, __be32 nw_rkey)
2648 {
2649 	u64 dma_addr = be64_to_cpu(nw_vaddr);
2650 	u32 rkey = ntohl(nw_rkey);
2651 	bool found = false;
2652 	int link_idx;
2653 
2654 	for (link_idx = 0; link_idx < SMC_LINKS_PER_LGR_MAX; link_idx++) {
2655 		if (lgr->lnk[link_idx].link_id == link_id) {
2656 			found = true;
2657 			break;
2658 		}
2659 	}
2660 	if (!found)
2661 		return;
2662 	lgr->rtokens[rtok_idx][link_idx].rkey = rkey;
2663 	lgr->rtokens[rtok_idx][link_idx].dma_addr = dma_addr;
2664 }
2665 
2666 /* add a new rtoken from peer */
2667 int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey)
2668 {
2669 	struct smc_link_group *lgr = smc_get_lgr(lnk);
2670 	u64 dma_addr = be64_to_cpu(nw_vaddr);
2671 	u32 rkey = ntohl(nw_rkey);
2672 	int i;
2673 
2674 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2675 		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2676 		    lgr->rtokens[i][lnk->link_idx].dma_addr == dma_addr &&
2677 		    test_bit(i, lgr->rtokens_used_mask)) {
2678 			/* already in list */
2679 			return i;
2680 		}
2681 	}
2682 	i = smc_rmb_reserve_rtoken_idx(lgr);
2683 	if (i < 0)
2684 		return i;
2685 	lgr->rtokens[i][lnk->link_idx].rkey = rkey;
2686 	lgr->rtokens[i][lnk->link_idx].dma_addr = dma_addr;
2687 	return i;
2688 }
2689 
2690 /* delete an rtoken from all links */
2691 int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey)
2692 {
2693 	struct smc_link_group *lgr = smc_get_lgr(lnk);
2694 	u32 rkey = ntohl(nw_rkey);
2695 	int i, j;
2696 
2697 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2698 		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2699 		    test_bit(i, lgr->rtokens_used_mask)) {
2700 			for (j = 0; j < SMC_LINKS_PER_LGR_MAX; j++) {
2701 				lgr->rtokens[i][j].rkey = 0;
2702 				lgr->rtokens[i][j].dma_addr = 0;
2703 			}
2704 			clear_bit(i, lgr->rtokens_used_mask);
2705 			return 0;
2706 		}
2707 	}
2708 	return -ENOENT;
2709 }
2710 
2711 /* save rkey and dma_addr received from peer during clc handshake */
2712 int smc_rmb_rtoken_handling(struct smc_connection *conn,
2713 			    struct smc_link *lnk,
2714 			    struct smc_clc_msg_accept_confirm *clc)
2715 {
2716 	conn->rtoken_idx = smc_rtoken_add(lnk, clc->r0.rmb_dma_addr,
2717 					  clc->r0.rmb_rkey);
2718 	if (conn->rtoken_idx < 0)
2719 		return conn->rtoken_idx;
2720 	return 0;
2721 }
2722 
2723 static void smc_core_going_away(void)
2724 {
2725 	struct smc_ib_device *smcibdev;
2726 	struct smcd_dev *smcd;
2727 
2728 	mutex_lock(&smc_ib_devices.mutex);
2729 	list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
2730 		int i;
2731 
2732 		for (i = 0; i < SMC_MAX_PORTS; i++)
2733 			set_bit(i, smcibdev->ports_going_away);
2734 	}
2735 	mutex_unlock(&smc_ib_devices.mutex);
2736 
2737 	mutex_lock(&smcd_dev_list.mutex);
2738 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
2739 		smcd->going_away = 1;
2740 	}
2741 	mutex_unlock(&smcd_dev_list.mutex);
2742 }
2743 
2744 /* Clean up all SMC link groups */
2745 static void smc_lgrs_shutdown(void)
2746 {
2747 	struct smcd_dev *smcd;
2748 
2749 	smc_core_going_away();
2750 
2751 	smc_smcr_terminate_all(NULL);
2752 
2753 	mutex_lock(&smcd_dev_list.mutex);
2754 	list_for_each_entry(smcd, &smcd_dev_list.list, list)
2755 		smc_smcd_terminate_all(smcd);
2756 	mutex_unlock(&smcd_dev_list.mutex);
2757 }
2758 
2759 static int smc_core_reboot_event(struct notifier_block *this,
2760 				 unsigned long event, void *ptr)
2761 {
2762 	smc_lgrs_shutdown();
2763 	smc_ib_unregister_client();
2764 	smc_ism_exit();
2765 	return 0;
2766 }
2767 
2768 static struct notifier_block smc_reboot_notifier = {
2769 	.notifier_call = smc_core_reboot_event,
2770 };
2771 
2772 int __init smc_core_init(void)
2773 {
2774 	return register_reboot_notifier(&smc_reboot_notifier);
2775 }
2776 
2777 /* Called (from smc_exit) when module is removed */
2778 void smc_core_exit(void)
2779 {
2780 	unregister_reboot_notifier(&smc_reboot_notifier);
2781 	smc_lgrs_shutdown();
2782 }
2783