xref: /linux/net/smc/smc_core.c (revision 3494bec0f6ac8ac06e0ad7c35933db345b2c5a83)
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 <net/tcp.h>
19 #include <net/sock.h>
20 #include <rdma/ib_verbs.h>
21 #include <rdma/ib_cache.h>
22 
23 #include "smc.h"
24 #include "smc_clc.h"
25 #include "smc_core.h"
26 #include "smc_ib.h"
27 #include "smc_wr.h"
28 #include "smc_llc.h"
29 #include "smc_cdc.h"
30 #include "smc_close.h"
31 #include "smc_ism.h"
32 
33 #define SMC_LGR_NUM_INCR		256
34 #define SMC_LGR_FREE_DELAY_SERV		(600 * HZ)
35 #define SMC_LGR_FREE_DELAY_CLNT		(SMC_LGR_FREE_DELAY_SERV + 10 * HZ)
36 #define SMC_LGR_FREE_DELAY_FAST		(8 * HZ)
37 
38 static struct smc_lgr_list smc_lgr_list = {	/* established link groups */
39 	.lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
40 	.list = LIST_HEAD_INIT(smc_lgr_list.list),
41 	.num = 0,
42 };
43 
44 static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */
45 static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted);
46 
47 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
48 			 struct smc_buf_desc *buf_desc);
49 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft);
50 
51 /* return head of link group list and its lock for a given link group */
52 static inline struct list_head *smc_lgr_list_head(struct smc_link_group *lgr,
53 						  spinlock_t **lgr_lock)
54 {
55 	if (lgr->is_smcd) {
56 		*lgr_lock = &lgr->smcd->lgr_lock;
57 		return &lgr->smcd->lgr_list;
58 	}
59 
60 	*lgr_lock = &smc_lgr_list.lock;
61 	return &smc_lgr_list.list;
62 }
63 
64 static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
65 {
66 	/* client link group creation always follows the server link group
67 	 * creation. For client use a somewhat higher removal delay time,
68 	 * otherwise there is a risk of out-of-sync link groups.
69 	 */
70 	if (!lgr->freeing && !lgr->freefast) {
71 		mod_delayed_work(system_wq, &lgr->free_work,
72 				 (!lgr->is_smcd && lgr->role == SMC_CLNT) ?
73 						SMC_LGR_FREE_DELAY_CLNT :
74 						SMC_LGR_FREE_DELAY_SERV);
75 	}
76 }
77 
78 void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr)
79 {
80 	if (!lgr->freeing && !lgr->freefast) {
81 		lgr->freefast = 1;
82 		mod_delayed_work(system_wq, &lgr->free_work,
83 				 SMC_LGR_FREE_DELAY_FAST);
84 	}
85 }
86 
87 /* Register connection's alert token in our lookup structure.
88  * To use rbtrees we have to implement our own insert core.
89  * Requires @conns_lock
90  * @smc		connection to register
91  * Returns 0 on success, != otherwise.
92  */
93 static void smc_lgr_add_alert_token(struct smc_connection *conn)
94 {
95 	struct rb_node **link, *parent = NULL;
96 	u32 token = conn->alert_token_local;
97 
98 	link = &conn->lgr->conns_all.rb_node;
99 	while (*link) {
100 		struct smc_connection *cur = rb_entry(*link,
101 					struct smc_connection, alert_node);
102 
103 		parent = *link;
104 		if (cur->alert_token_local > token)
105 			link = &parent->rb_left;
106 		else
107 			link = &parent->rb_right;
108 	}
109 	/* Put the new node there */
110 	rb_link_node(&conn->alert_node, parent, link);
111 	rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
112 }
113 
114 /* Register connection in link group by assigning an alert token
115  * registered in a search tree.
116  * Requires @conns_lock
117  * Note that '0' is a reserved value and not assigned.
118  */
119 static void smc_lgr_register_conn(struct smc_connection *conn)
120 {
121 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
122 	static atomic_t nexttoken = ATOMIC_INIT(0);
123 
124 	/* find a new alert_token_local value not yet used by some connection
125 	 * in this link group
126 	 */
127 	sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
128 	while (!conn->alert_token_local) {
129 		conn->alert_token_local = atomic_inc_return(&nexttoken);
130 		if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
131 			conn->alert_token_local = 0;
132 	}
133 	smc_lgr_add_alert_token(conn);
134 	conn->lgr->conns_num++;
135 }
136 
137 /* Unregister connection and reset the alert token of the given connection<
138  */
139 static void __smc_lgr_unregister_conn(struct smc_connection *conn)
140 {
141 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
142 	struct smc_link_group *lgr = conn->lgr;
143 
144 	rb_erase(&conn->alert_node, &lgr->conns_all);
145 	lgr->conns_num--;
146 	conn->alert_token_local = 0;
147 	sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
148 }
149 
150 /* Unregister connection from lgr
151  */
152 static void smc_lgr_unregister_conn(struct smc_connection *conn)
153 {
154 	struct smc_link_group *lgr = conn->lgr;
155 
156 	if (!lgr)
157 		return;
158 	write_lock_bh(&lgr->conns_lock);
159 	if (conn->alert_token_local) {
160 		__smc_lgr_unregister_conn(conn);
161 	}
162 	write_unlock_bh(&lgr->conns_lock);
163 	conn->lgr = NULL;
164 }
165 
166 /* Send delete link, either as client to request the initiation
167  * of the DELETE LINK sequence from server; or as server to
168  * initiate the delete processing. See smc_llc_rx_delete_link().
169  */
170 static int smc_link_send_delete(struct smc_link *lnk, bool orderly)
171 {
172 	if (lnk->state == SMC_LNK_ACTIVE &&
173 	    !smc_llc_send_delete_link(lnk, SMC_LLC_REQ, orderly)) {
174 		smc_llc_link_deleting(lnk);
175 		return 0;
176 	}
177 	return -ENOTCONN;
178 }
179 
180 static void smc_lgr_free(struct smc_link_group *lgr);
181 
182 static void smc_lgr_free_work(struct work_struct *work)
183 {
184 	struct smc_link_group *lgr = container_of(to_delayed_work(work),
185 						  struct smc_link_group,
186 						  free_work);
187 	spinlock_t *lgr_lock;
188 	struct smc_link *lnk;
189 	bool conns;
190 
191 	smc_lgr_list_head(lgr, &lgr_lock);
192 	spin_lock_bh(lgr_lock);
193 	if (lgr->freeing) {
194 		spin_unlock_bh(lgr_lock);
195 		return;
196 	}
197 	read_lock_bh(&lgr->conns_lock);
198 	conns = RB_EMPTY_ROOT(&lgr->conns_all);
199 	read_unlock_bh(&lgr->conns_lock);
200 	if (!conns) { /* number of lgr connections is no longer zero */
201 		spin_unlock_bh(lgr_lock);
202 		return;
203 	}
204 	list_del_init(&lgr->list); /* remove from smc_lgr_list */
205 
206 	lnk = &lgr->lnk[SMC_SINGLE_LINK];
207 	if (!lgr->is_smcd && !lgr->terminating)	{
208 		/* try to send del link msg, on error free lgr immediately */
209 		if (lnk->state == SMC_LNK_ACTIVE &&
210 		    !smc_link_send_delete(lnk, true)) {
211 			/* reschedule in case we never receive a response */
212 			smc_lgr_schedule_free_work(lgr);
213 			spin_unlock_bh(lgr_lock);
214 			return;
215 		}
216 	}
217 	lgr->freeing = 1; /* this instance does the freeing, no new schedule */
218 	spin_unlock_bh(lgr_lock);
219 	cancel_delayed_work(&lgr->free_work);
220 
221 	if (!lgr->is_smcd && lnk->state != SMC_LNK_INACTIVE)
222 		smc_llc_link_inactive(lnk);
223 	if (lgr->is_smcd && !lgr->terminating)
224 		smc_ism_signal_shutdown(lgr);
225 	smc_lgr_free(lgr);
226 }
227 
228 static void smc_lgr_terminate_work(struct work_struct *work)
229 {
230 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
231 						  terminate_work);
232 
233 	__smc_lgr_terminate(lgr, true);
234 }
235 
236 /* create a new SMC link group */
237 static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
238 {
239 	struct smc_link_group *lgr;
240 	struct list_head *lgr_list;
241 	struct smc_link *lnk;
242 	spinlock_t *lgr_lock;
243 	u8 rndvec[3];
244 	int rc = 0;
245 	int i;
246 
247 	if (ini->is_smcd && ini->vlan_id) {
248 		if (smc_ism_get_vlan(ini->ism_dev, ini->vlan_id)) {
249 			rc = SMC_CLC_DECL_ISMVLANERR;
250 			goto out;
251 		}
252 	}
253 
254 	lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
255 	if (!lgr) {
256 		rc = SMC_CLC_DECL_MEM;
257 		goto ism_put_vlan;
258 	}
259 	lgr->is_smcd = ini->is_smcd;
260 	lgr->sync_err = 0;
261 	lgr->terminating = 0;
262 	lgr->freefast = 0;
263 	lgr->freeing = 0;
264 	lgr->vlan_id = ini->vlan_id;
265 	rwlock_init(&lgr->sndbufs_lock);
266 	rwlock_init(&lgr->rmbs_lock);
267 	rwlock_init(&lgr->conns_lock);
268 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
269 		INIT_LIST_HEAD(&lgr->sndbufs[i]);
270 		INIT_LIST_HEAD(&lgr->rmbs[i]);
271 	}
272 	smc_lgr_list.num += SMC_LGR_NUM_INCR;
273 	memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
274 	INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
275 	INIT_WORK(&lgr->terminate_work, smc_lgr_terminate_work);
276 	lgr->conns_all = RB_ROOT;
277 	if (ini->is_smcd) {
278 		/* SMC-D specific settings */
279 		get_device(&ini->ism_dev->dev);
280 		lgr->peer_gid = ini->ism_gid;
281 		lgr->smcd = ini->ism_dev;
282 		lgr_list = &ini->ism_dev->lgr_list;
283 		lgr_lock = &lgr->smcd->lgr_lock;
284 		lgr->peer_shutdown = 0;
285 		atomic_inc(&ini->ism_dev->lgr_cnt);
286 	} else {
287 		/* SMC-R specific settings */
288 		get_device(&ini->ib_dev->ibdev->dev);
289 		lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
290 		memcpy(lgr->peer_systemid, ini->ib_lcl->id_for_peer,
291 		       SMC_SYSTEMID_LEN);
292 
293 		lnk = &lgr->lnk[SMC_SINGLE_LINK];
294 		/* initialize link */
295 		lnk->state = SMC_LNK_ACTIVATING;
296 		lnk->link_id = SMC_SINGLE_LINK;
297 		lnk->smcibdev = ini->ib_dev;
298 		lnk->ibport = ini->ib_port;
299 		lgr_list = &smc_lgr_list.list;
300 		lgr_lock = &smc_lgr_list.lock;
301 		lnk->path_mtu =
302 			ini->ib_dev->pattr[ini->ib_port - 1].active_mtu;
303 		if (!ini->ib_dev->initialized)
304 			smc_ib_setup_per_ibdev(ini->ib_dev);
305 		get_random_bytes(rndvec, sizeof(rndvec));
306 		lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
307 			(rndvec[2] << 16);
308 		rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
309 					  ini->vlan_id, lnk->gid,
310 					  &lnk->sgid_index);
311 		if (rc)
312 			goto free_lgr;
313 		rc = smc_llc_link_init(lnk);
314 		if (rc)
315 			goto free_lgr;
316 		rc = smc_wr_alloc_link_mem(lnk);
317 		if (rc)
318 			goto clear_llc_lnk;
319 		rc = smc_ib_create_protection_domain(lnk);
320 		if (rc)
321 			goto free_link_mem;
322 		rc = smc_ib_create_queue_pair(lnk);
323 		if (rc)
324 			goto dealloc_pd;
325 		rc = smc_wr_create_link(lnk);
326 		if (rc)
327 			goto destroy_qp;
328 		atomic_inc(&lgr_cnt);
329 		atomic_inc(&ini->ib_dev->lnk_cnt);
330 	}
331 	smc->conn.lgr = lgr;
332 	spin_lock_bh(lgr_lock);
333 	list_add(&lgr->list, lgr_list);
334 	spin_unlock_bh(lgr_lock);
335 	return 0;
336 
337 destroy_qp:
338 	smc_ib_destroy_queue_pair(lnk);
339 dealloc_pd:
340 	smc_ib_dealloc_protection_domain(lnk);
341 free_link_mem:
342 	smc_wr_free_link_mem(lnk);
343 clear_llc_lnk:
344 	smc_llc_link_clear(lnk);
345 free_lgr:
346 	kfree(lgr);
347 ism_put_vlan:
348 	if (ini->is_smcd && ini->vlan_id)
349 		smc_ism_put_vlan(ini->ism_dev, ini->vlan_id);
350 out:
351 	if (rc < 0) {
352 		if (rc == -ENOMEM)
353 			rc = SMC_CLC_DECL_MEM;
354 		else
355 			rc = SMC_CLC_DECL_INTERR;
356 	}
357 	return rc;
358 }
359 
360 static void smc_buf_unuse(struct smc_connection *conn,
361 			  struct smc_link_group *lgr)
362 {
363 	if (conn->sndbuf_desc)
364 		conn->sndbuf_desc->used = 0;
365 	if (conn->rmb_desc) {
366 		if (!conn->rmb_desc->regerr) {
367 			if (!lgr->is_smcd && !list_empty(&lgr->list)) {
368 				/* unregister rmb with peer */
369 				smc_llc_do_delete_rkey(
370 						&lgr->lnk[SMC_SINGLE_LINK],
371 						conn->rmb_desc);
372 			}
373 			conn->rmb_desc->used = 0;
374 		} else {
375 			/* buf registration failed, reuse not possible */
376 			write_lock_bh(&lgr->rmbs_lock);
377 			list_del(&conn->rmb_desc->list);
378 			write_unlock_bh(&lgr->rmbs_lock);
379 
380 			smc_buf_free(lgr, true, conn->rmb_desc);
381 		}
382 	}
383 }
384 
385 /* remove a finished connection from its link group */
386 void smc_conn_free(struct smc_connection *conn)
387 {
388 	struct smc_link_group *lgr = conn->lgr;
389 
390 	if (!lgr)
391 		return;
392 	if (lgr->is_smcd) {
393 		if (!list_empty(&lgr->list))
394 			smc_ism_unset_conn(conn);
395 		tasklet_kill(&conn->rx_tsklet);
396 	} else {
397 		smc_cdc_tx_dismiss_slots(conn);
398 	}
399 	if (!list_empty(&lgr->list)) {
400 		smc_lgr_unregister_conn(conn);
401 		smc_buf_unuse(conn, lgr); /* allow buffer reuse */
402 	}
403 
404 	if (!lgr->conns_num)
405 		smc_lgr_schedule_free_work(lgr);
406 }
407 
408 static void smc_link_clear(struct smc_link *lnk)
409 {
410 	lnk->peer_qpn = 0;
411 	smc_llc_link_clear(lnk);
412 	smc_ib_modify_qp_reset(lnk);
413 	smc_wr_free_link(lnk);
414 	smc_ib_destroy_queue_pair(lnk);
415 	smc_ib_dealloc_protection_domain(lnk);
416 	smc_wr_free_link_mem(lnk);
417 	if (!atomic_dec_return(&lnk->smcibdev->lnk_cnt))
418 		wake_up(&lnk->smcibdev->lnks_deleted);
419 }
420 
421 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
422 			  struct smc_buf_desc *buf_desc)
423 {
424 	struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
425 
426 	if (is_rmb) {
427 		if (buf_desc->mr_rx[SMC_SINGLE_LINK])
428 			smc_ib_put_memory_region(
429 					buf_desc->mr_rx[SMC_SINGLE_LINK]);
430 		smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
431 				    DMA_FROM_DEVICE);
432 	} else {
433 		smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
434 				    DMA_TO_DEVICE);
435 	}
436 	sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]);
437 	if (buf_desc->pages)
438 		__free_pages(buf_desc->pages, buf_desc->order);
439 	kfree(buf_desc);
440 }
441 
442 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
443 			  struct smc_buf_desc *buf_desc)
444 {
445 	if (is_dmb) {
446 		/* restore original buf len */
447 		buf_desc->len += sizeof(struct smcd_cdc_msg);
448 		smc_ism_unregister_dmb(lgr->smcd, buf_desc);
449 	} else {
450 		kfree(buf_desc->cpu_addr);
451 	}
452 	kfree(buf_desc);
453 }
454 
455 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
456 			 struct smc_buf_desc *buf_desc)
457 {
458 	if (lgr->is_smcd)
459 		smcd_buf_free(lgr, is_rmb, buf_desc);
460 	else
461 		smcr_buf_free(lgr, is_rmb, buf_desc);
462 }
463 
464 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
465 {
466 	struct smc_buf_desc *buf_desc, *bf_desc;
467 	struct list_head *buf_list;
468 	int i;
469 
470 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
471 		if (is_rmb)
472 			buf_list = &lgr->rmbs[i];
473 		else
474 			buf_list = &lgr->sndbufs[i];
475 		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
476 					 list) {
477 			list_del(&buf_desc->list);
478 			smc_buf_free(lgr, is_rmb, buf_desc);
479 		}
480 	}
481 }
482 
483 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
484 {
485 	/* free send buffers */
486 	__smc_lgr_free_bufs(lgr, false);
487 	/* free rmbs */
488 	__smc_lgr_free_bufs(lgr, true);
489 }
490 
491 /* remove a link group */
492 static void smc_lgr_free(struct smc_link_group *lgr)
493 {
494 	smc_lgr_free_bufs(lgr);
495 	if (lgr->is_smcd) {
496 		if (!lgr->terminating) {
497 			smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
498 			put_device(&lgr->smcd->dev);
499 		}
500 		if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
501 			wake_up(&lgr->smcd->lgrs_deleted);
502 	} else {
503 		smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]);
504 		put_device(&lgr->lnk[SMC_SINGLE_LINK].smcibdev->ibdev->dev);
505 		if (!atomic_dec_return(&lgr_cnt))
506 			wake_up(&lgrs_deleted);
507 	}
508 	kfree(lgr);
509 }
510 
511 void smc_lgr_forget(struct smc_link_group *lgr)
512 {
513 	struct list_head *lgr_list;
514 	spinlock_t *lgr_lock;
515 
516 	lgr_list = smc_lgr_list_head(lgr, &lgr_lock);
517 	spin_lock_bh(lgr_lock);
518 	/* do not use this link group for new connections */
519 	if (!list_empty(lgr_list))
520 		list_del_init(lgr_list);
521 	spin_unlock_bh(lgr_lock);
522 }
523 
524 static void smcd_unregister_all_dmbs(struct smc_link_group *lgr)
525 {
526 	int i;
527 
528 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
529 		struct smc_buf_desc *buf_desc;
530 
531 		list_for_each_entry(buf_desc, &lgr->rmbs[i], list) {
532 			buf_desc->len += sizeof(struct smcd_cdc_msg);
533 			smc_ism_unregister_dmb(lgr->smcd, buf_desc);
534 		}
535 	}
536 }
537 
538 static void smc_sk_wake_ups(struct smc_sock *smc)
539 {
540 	smc->sk.sk_write_space(&smc->sk);
541 	smc->sk.sk_data_ready(&smc->sk);
542 	smc->sk.sk_state_change(&smc->sk);
543 }
544 
545 /* kill a connection */
546 static void smc_conn_kill(struct smc_connection *conn, bool soft)
547 {
548 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
549 
550 	if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
551 		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
552 	else
553 		smc_close_abort(conn);
554 	conn->killed = 1;
555 	smc->sk.sk_err = ECONNABORTED;
556 	smc_sk_wake_ups(smc);
557 	if (conn->lgr->is_smcd) {
558 		smc_ism_unset_conn(conn);
559 		if (soft)
560 			tasklet_kill(&conn->rx_tsklet);
561 		else
562 			tasklet_unlock_wait(&conn->rx_tsklet);
563 	} else {
564 		smc_cdc_tx_dismiss_slots(conn);
565 	}
566 	smc_lgr_unregister_conn(conn);
567 	smc_close_active_abort(smc);
568 }
569 
570 static void smc_lgr_cleanup(struct smc_link_group *lgr)
571 {
572 	if (lgr->is_smcd) {
573 		smc_ism_signal_shutdown(lgr);
574 		smcd_unregister_all_dmbs(lgr);
575 		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
576 		put_device(&lgr->smcd->dev);
577 	} else {
578 		struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
579 
580 		if (lnk->state != SMC_LNK_INACTIVE)
581 			smc_llc_link_inactive(lnk);
582 	}
583 }
584 
585 /* terminate link group
586  * @soft: true if link group shutdown can take its time
587  *	  false if immediate link group shutdown is required
588  */
589 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
590 {
591 	struct smc_connection *conn;
592 	struct smc_sock *smc;
593 	struct rb_node *node;
594 
595 	if (lgr->terminating)
596 		return;	/* lgr already terminating */
597 	if (!soft)
598 		cancel_delayed_work_sync(&lgr->free_work);
599 	lgr->terminating = 1;
600 	if (!lgr->is_smcd)
601 		smc_llc_link_inactive(&lgr->lnk[SMC_SINGLE_LINK]);
602 
603 	/* kill remaining link group connections */
604 	read_lock_bh(&lgr->conns_lock);
605 	node = rb_first(&lgr->conns_all);
606 	while (node) {
607 		read_unlock_bh(&lgr->conns_lock);
608 		conn = rb_entry(node, struct smc_connection, alert_node);
609 		smc = container_of(conn, struct smc_sock, conn);
610 		sock_hold(&smc->sk); /* sock_put below */
611 		lock_sock(&smc->sk);
612 		smc_conn_kill(conn, soft);
613 		release_sock(&smc->sk);
614 		sock_put(&smc->sk); /* sock_hold above */
615 		read_lock_bh(&lgr->conns_lock);
616 		node = rb_first(&lgr->conns_all);
617 	}
618 	read_unlock_bh(&lgr->conns_lock);
619 	smc_lgr_cleanup(lgr);
620 	if (soft)
621 		smc_lgr_schedule_free_work_fast(lgr);
622 	else
623 		smc_lgr_free(lgr);
624 }
625 
626 /* unlink link group and schedule termination */
627 void smc_lgr_terminate_sched(struct smc_link_group *lgr)
628 {
629 	spinlock_t *lgr_lock;
630 
631 	smc_lgr_list_head(lgr, &lgr_lock);
632 	spin_lock_bh(lgr_lock);
633 	if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
634 		spin_unlock_bh(lgr_lock);
635 		return;	/* lgr already terminating */
636 	}
637 	list_del_init(&lgr->list);
638 	spin_unlock_bh(lgr_lock);
639 	schedule_work(&lgr->terminate_work);
640 }
641 
642 /* Called when IB port is terminated */
643 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)
644 {
645 	struct smc_link_group *lgr, *l;
646 	LIST_HEAD(lgr_free_list);
647 
648 	spin_lock_bh(&smc_lgr_list.lock);
649 	list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
650 		if (!lgr->is_smcd &&
651 		    lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev &&
652 		    lgr->lnk[SMC_SINGLE_LINK].ibport == ibport) {
653 			list_move(&lgr->list, &lgr_free_list);
654 			lgr->freeing = 1;
655 		}
656 	}
657 	spin_unlock_bh(&smc_lgr_list.lock);
658 
659 	list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
660 		list_del_init(&lgr->list);
661 		__smc_lgr_terminate(lgr, false);
662 	}
663 }
664 
665 /* Called when peer lgr shutdown (regularly or abnormally) is received */
666 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
667 {
668 	struct smc_link_group *lgr, *l;
669 	LIST_HEAD(lgr_free_list);
670 
671 	/* run common cleanup function and build free list */
672 	spin_lock_bh(&dev->lgr_lock);
673 	list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
674 		if ((!peer_gid || lgr->peer_gid == peer_gid) &&
675 		    (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
676 			if (peer_gid) /* peer triggered termination */
677 				lgr->peer_shutdown = 1;
678 			list_move(&lgr->list, &lgr_free_list);
679 		}
680 	}
681 	spin_unlock_bh(&dev->lgr_lock);
682 
683 	/* cancel the regular free workers and actually free lgrs */
684 	list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
685 		list_del_init(&lgr->list);
686 		schedule_work(&lgr->terminate_work);
687 	}
688 }
689 
690 /* Called when an SMCD device is removed or the smc module is unloaded */
691 void smc_smcd_terminate_all(struct smcd_dev *smcd)
692 {
693 	struct smc_link_group *lgr, *lg;
694 	LIST_HEAD(lgr_free_list);
695 
696 	spin_lock_bh(&smcd->lgr_lock);
697 	list_splice_init(&smcd->lgr_list, &lgr_free_list);
698 	list_for_each_entry(lgr, &lgr_free_list, list)
699 		lgr->freeing = 1;
700 	spin_unlock_bh(&smcd->lgr_lock);
701 
702 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
703 		list_del_init(&lgr->list);
704 		__smc_lgr_terminate(lgr, false);
705 	}
706 
707 	if (atomic_read(&smcd->lgr_cnt))
708 		wait_event(smcd->lgrs_deleted, !atomic_read(&smcd->lgr_cnt));
709 }
710 
711 /* Called when an SMCR device is removed or the smc module is unloaded.
712  * If smcibdev is given, all SMCR link groups using this device are terminated.
713  * If smcibdev is NULL, all SMCR link groups are terminated.
714  */
715 void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
716 {
717 	struct smc_link_group *lgr, *lg;
718 	LIST_HEAD(lgr_free_list);
719 
720 	spin_lock_bh(&smc_lgr_list.lock);
721 	if (!smcibdev) {
722 		list_splice_init(&smc_lgr_list.list, &lgr_free_list);
723 		list_for_each_entry(lgr, &lgr_free_list, list)
724 			lgr->freeing = 1;
725 	} else {
726 		list_for_each_entry_safe(lgr, lg, &smc_lgr_list.list, list) {
727 			if (lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev) {
728 				list_move(&lgr->list, &lgr_free_list);
729 				lgr->freeing = 1;
730 			}
731 		}
732 	}
733 	spin_unlock_bh(&smc_lgr_list.lock);
734 
735 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
736 		list_del_init(&lgr->list);
737 		__smc_lgr_terminate(lgr, false);
738 	}
739 
740 	if (smcibdev) {
741 		if (atomic_read(&smcibdev->lnk_cnt))
742 			wait_event(smcibdev->lnks_deleted,
743 				   !atomic_read(&smcibdev->lnk_cnt));
744 	} else {
745 		if (atomic_read(&lgr_cnt))
746 			wait_event(lgrs_deleted, !atomic_read(&lgr_cnt));
747 	}
748 }
749 
750 /* Determine vlan of internal TCP socket.
751  * @vlan_id: address to store the determined vlan id into
752  */
753 int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
754 {
755 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
756 	struct net_device *ndev;
757 	int i, nest_lvl, rc = 0;
758 
759 	ini->vlan_id = 0;
760 	if (!dst) {
761 		rc = -ENOTCONN;
762 		goto out;
763 	}
764 	if (!dst->dev) {
765 		rc = -ENODEV;
766 		goto out_rel;
767 	}
768 
769 	ndev = dst->dev;
770 	if (is_vlan_dev(ndev)) {
771 		ini->vlan_id = vlan_dev_vlan_id(ndev);
772 		goto out_rel;
773 	}
774 
775 	rtnl_lock();
776 	nest_lvl = ndev->lower_level;
777 	for (i = 0; i < nest_lvl; i++) {
778 		struct list_head *lower = &ndev->adj_list.lower;
779 
780 		if (list_empty(lower))
781 			break;
782 		lower = lower->next;
783 		ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);
784 		if (is_vlan_dev(ndev)) {
785 			ini->vlan_id = vlan_dev_vlan_id(ndev);
786 			break;
787 		}
788 	}
789 	rtnl_unlock();
790 
791 out_rel:
792 	dst_release(dst);
793 out:
794 	return rc;
795 }
796 
797 static bool smcr_lgr_match(struct smc_link_group *lgr,
798 			   struct smc_clc_msg_local *lcl,
799 			   enum smc_lgr_role role, u32 clcqpn)
800 {
801 	return !memcmp(lgr->peer_systemid, lcl->id_for_peer,
802 		       SMC_SYSTEMID_LEN) &&
803 		!memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid,
804 			SMC_GID_SIZE) &&
805 		!memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac,
806 			sizeof(lcl->mac)) &&
807 		lgr->role == role &&
808 		(lgr->role == SMC_SERV ||
809 		 lgr->lnk[SMC_SINGLE_LINK].peer_qpn == clcqpn);
810 }
811 
812 static bool smcd_lgr_match(struct smc_link_group *lgr,
813 			   struct smcd_dev *smcismdev, u64 peer_gid)
814 {
815 	return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
816 }
817 
818 /* create a new SMC connection (and a new link group if necessary) */
819 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
820 {
821 	struct smc_connection *conn = &smc->conn;
822 	struct list_head *lgr_list;
823 	struct smc_link_group *lgr;
824 	enum smc_lgr_role role;
825 	spinlock_t *lgr_lock;
826 	int rc = 0;
827 
828 	lgr_list = ini->is_smcd ? &ini->ism_dev->lgr_list : &smc_lgr_list.list;
829 	lgr_lock = ini->is_smcd ? &ini->ism_dev->lgr_lock : &smc_lgr_list.lock;
830 	ini->cln_first_contact = SMC_FIRST_CONTACT;
831 	role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
832 	if (role == SMC_CLNT && ini->srv_first_contact)
833 		/* create new link group as well */
834 		goto create;
835 
836 	/* determine if an existing link group can be reused */
837 	spin_lock_bh(lgr_lock);
838 	list_for_each_entry(lgr, lgr_list, list) {
839 		write_lock_bh(&lgr->conns_lock);
840 		if ((ini->is_smcd ?
841 		     smcd_lgr_match(lgr, ini->ism_dev, ini->ism_gid) :
842 		     smcr_lgr_match(lgr, ini->ib_lcl, role, ini->ib_clcqpn)) &&
843 		    !lgr->sync_err &&
844 		    lgr->vlan_id == ini->vlan_id &&
845 		    (role == SMC_CLNT ||
846 		     lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) {
847 			/* link group found */
848 			ini->cln_first_contact = SMC_REUSE_CONTACT;
849 			conn->lgr = lgr;
850 			smc_lgr_register_conn(conn); /* add smc conn to lgr */
851 			if (delayed_work_pending(&lgr->free_work))
852 				cancel_delayed_work(&lgr->free_work);
853 			write_unlock_bh(&lgr->conns_lock);
854 			break;
855 		}
856 		write_unlock_bh(&lgr->conns_lock);
857 	}
858 	spin_unlock_bh(lgr_lock);
859 
860 	if (role == SMC_CLNT && !ini->srv_first_contact &&
861 	    ini->cln_first_contact == SMC_FIRST_CONTACT) {
862 		/* Server reuses a link group, but Client wants to start
863 		 * a new one
864 		 * send out_of_sync decline, reason synchr. error
865 		 */
866 		return SMC_CLC_DECL_SYNCERR;
867 	}
868 
869 create:
870 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
871 		rc = smc_lgr_create(smc, ini);
872 		if (rc)
873 			goto out;
874 		lgr = conn->lgr;
875 		write_lock_bh(&lgr->conns_lock);
876 		smc_lgr_register_conn(conn); /* add smc conn to lgr */
877 		write_unlock_bh(&lgr->conns_lock);
878 	}
879 	conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
880 	conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
881 	conn->urg_state = SMC_URG_READ;
882 	if (ini->is_smcd) {
883 		conn->rx_off = sizeof(struct smcd_cdc_msg);
884 		smcd_cdc_rx_init(conn); /* init tasklet for this conn */
885 	}
886 #ifndef KERNEL_HAS_ATOMIC64
887 	spin_lock_init(&conn->acurs_lock);
888 #endif
889 
890 out:
891 	return rc;
892 }
893 
894 /* convert the RMB size into the compressed notation - minimum 16K.
895  * In contrast to plain ilog2, this rounds towards the next power of 2,
896  * so the socket application gets at least its desired sndbuf / rcvbuf size.
897  */
898 static u8 smc_compress_bufsize(int size)
899 {
900 	u8 compressed;
901 
902 	if (size <= SMC_BUF_MIN_SIZE)
903 		return 0;
904 
905 	size = (size - 1) >> 14;
906 	compressed = ilog2(size) + 1;
907 	if (compressed >= SMC_RMBE_SIZES)
908 		compressed = SMC_RMBE_SIZES - 1;
909 	return compressed;
910 }
911 
912 /* convert the RMB size from compressed notation into integer */
913 int smc_uncompress_bufsize(u8 compressed)
914 {
915 	u32 size;
916 
917 	size = 0x00000001 << (((int)compressed) + 14);
918 	return (int)size;
919 }
920 
921 /* try to reuse a sndbuf or rmb description slot for a certain
922  * buffer size; if not available, return NULL
923  */
924 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
925 					     rwlock_t *lock,
926 					     struct list_head *buf_list)
927 {
928 	struct smc_buf_desc *buf_slot;
929 
930 	read_lock_bh(lock);
931 	list_for_each_entry(buf_slot, buf_list, list) {
932 		if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
933 			read_unlock_bh(lock);
934 			return buf_slot;
935 		}
936 	}
937 	read_unlock_bh(lock);
938 	return NULL;
939 }
940 
941 /* one of the conditions for announcing a receiver's current window size is
942  * that it "results in a minimum increase in the window size of 10% of the
943  * receive buffer space" [RFC7609]
944  */
945 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
946 {
947 	return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
948 }
949 
950 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
951 						bool is_rmb, int bufsize)
952 {
953 	struct smc_buf_desc *buf_desc;
954 	struct smc_link *lnk;
955 	int rc;
956 
957 	/* try to alloc a new buffer */
958 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
959 	if (!buf_desc)
960 		return ERR_PTR(-ENOMEM);
961 
962 	buf_desc->order = get_order(bufsize);
963 	buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
964 				      __GFP_NOMEMALLOC | __GFP_COMP |
965 				      __GFP_NORETRY | __GFP_ZERO,
966 				      buf_desc->order);
967 	if (!buf_desc->pages) {
968 		kfree(buf_desc);
969 		return ERR_PTR(-EAGAIN);
970 	}
971 	buf_desc->cpu_addr = (void *)page_address(buf_desc->pages);
972 
973 	/* build the sg table from the pages */
974 	lnk = &lgr->lnk[SMC_SINGLE_LINK];
975 	rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1,
976 			    GFP_KERNEL);
977 	if (rc) {
978 		smc_buf_free(lgr, is_rmb, buf_desc);
979 		return ERR_PTR(rc);
980 	}
981 	sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl,
982 		   buf_desc->cpu_addr, bufsize);
983 
984 	/* map sg table to DMA address */
985 	rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc,
986 			       is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
987 	/* SMC protocol depends on mapping to one DMA address only */
988 	if (rc != 1)  {
989 		smc_buf_free(lgr, is_rmb, buf_desc);
990 		return ERR_PTR(-EAGAIN);
991 	}
992 
993 	/* create a new memory region for the RMB */
994 	if (is_rmb) {
995 		rc = smc_ib_get_memory_region(lnk->roce_pd,
996 					      IB_ACCESS_REMOTE_WRITE |
997 					      IB_ACCESS_LOCAL_WRITE,
998 					      buf_desc);
999 		if (rc) {
1000 			smc_buf_free(lgr, is_rmb, buf_desc);
1001 			return ERR_PTR(rc);
1002 		}
1003 	}
1004 
1005 	buf_desc->len = bufsize;
1006 	return buf_desc;
1007 }
1008 
1009 #define SMCD_DMBE_SIZES		7 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
1010 
1011 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
1012 						bool is_dmb, int bufsize)
1013 {
1014 	struct smc_buf_desc *buf_desc;
1015 	int rc;
1016 
1017 	if (smc_compress_bufsize(bufsize) > SMCD_DMBE_SIZES)
1018 		return ERR_PTR(-EAGAIN);
1019 
1020 	/* try to alloc a new DMB */
1021 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
1022 	if (!buf_desc)
1023 		return ERR_PTR(-ENOMEM);
1024 	if (is_dmb) {
1025 		rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
1026 		if (rc) {
1027 			kfree(buf_desc);
1028 			return ERR_PTR(-EAGAIN);
1029 		}
1030 		buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
1031 		/* CDC header stored in buf. So, pretend it was smaller */
1032 		buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
1033 	} else {
1034 		buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
1035 					     __GFP_NOWARN | __GFP_NORETRY |
1036 					     __GFP_NOMEMALLOC);
1037 		if (!buf_desc->cpu_addr) {
1038 			kfree(buf_desc);
1039 			return ERR_PTR(-EAGAIN);
1040 		}
1041 		buf_desc->len = bufsize;
1042 	}
1043 	return buf_desc;
1044 }
1045 
1046 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
1047 {
1048 	struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
1049 	struct smc_connection *conn = &smc->conn;
1050 	struct smc_link_group *lgr = conn->lgr;
1051 	struct list_head *buf_list;
1052 	int bufsize, bufsize_short;
1053 	int sk_buf_size;
1054 	rwlock_t *lock;
1055 
1056 	if (is_rmb)
1057 		/* use socket recv buffer size (w/o overhead) as start value */
1058 		sk_buf_size = smc->sk.sk_rcvbuf / 2;
1059 	else
1060 		/* use socket send buffer size (w/o overhead) as start value */
1061 		sk_buf_size = smc->sk.sk_sndbuf / 2;
1062 
1063 	for (bufsize_short = smc_compress_bufsize(sk_buf_size);
1064 	     bufsize_short >= 0; bufsize_short--) {
1065 
1066 		if (is_rmb) {
1067 			lock = &lgr->rmbs_lock;
1068 			buf_list = &lgr->rmbs[bufsize_short];
1069 		} else {
1070 			lock = &lgr->sndbufs_lock;
1071 			buf_list = &lgr->sndbufs[bufsize_short];
1072 		}
1073 		bufsize = smc_uncompress_bufsize(bufsize_short);
1074 		if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)
1075 			continue;
1076 
1077 		/* check for reusable slot in the link group */
1078 		buf_desc = smc_buf_get_slot(bufsize_short, lock, buf_list);
1079 		if (buf_desc) {
1080 			memset(buf_desc->cpu_addr, 0, bufsize);
1081 			break; /* found reusable slot */
1082 		}
1083 
1084 		if (is_smcd)
1085 			buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
1086 		else
1087 			buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
1088 
1089 		if (PTR_ERR(buf_desc) == -ENOMEM)
1090 			break;
1091 		if (IS_ERR(buf_desc))
1092 			continue;
1093 
1094 		buf_desc->used = 1;
1095 		write_lock_bh(lock);
1096 		list_add(&buf_desc->list, buf_list);
1097 		write_unlock_bh(lock);
1098 		break; /* found */
1099 	}
1100 
1101 	if (IS_ERR(buf_desc))
1102 		return -ENOMEM;
1103 
1104 	if (is_rmb) {
1105 		conn->rmb_desc = buf_desc;
1106 		conn->rmbe_size_short = bufsize_short;
1107 		smc->sk.sk_rcvbuf = bufsize * 2;
1108 		atomic_set(&conn->bytes_to_rcv, 0);
1109 		conn->rmbe_update_limit =
1110 			smc_rmb_wnd_update_limit(buf_desc->len);
1111 		if (is_smcd)
1112 			smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
1113 	} else {
1114 		conn->sndbuf_desc = buf_desc;
1115 		smc->sk.sk_sndbuf = bufsize * 2;
1116 		atomic_set(&conn->sndbuf_space, bufsize);
1117 	}
1118 	return 0;
1119 }
1120 
1121 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)
1122 {
1123 	struct smc_link_group *lgr = conn->lgr;
1124 
1125 	if (!conn->lgr || conn->lgr->is_smcd)
1126 		return;
1127 	smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
1128 			       conn->sndbuf_desc, DMA_TO_DEVICE);
1129 }
1130 
1131 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
1132 {
1133 	struct smc_link_group *lgr = conn->lgr;
1134 
1135 	if (!conn->lgr || conn->lgr->is_smcd)
1136 		return;
1137 	smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
1138 				  conn->sndbuf_desc, DMA_TO_DEVICE);
1139 }
1140 
1141 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
1142 {
1143 	struct smc_link_group *lgr = conn->lgr;
1144 
1145 	if (!conn->lgr || conn->lgr->is_smcd)
1146 		return;
1147 	smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
1148 			       conn->rmb_desc, DMA_FROM_DEVICE);
1149 }
1150 
1151 void smc_rmb_sync_sg_for_device(struct smc_connection *conn)
1152 {
1153 	struct smc_link_group *lgr = conn->lgr;
1154 
1155 	if (!conn->lgr || conn->lgr->is_smcd)
1156 		return;
1157 	smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
1158 				  conn->rmb_desc, DMA_FROM_DEVICE);
1159 }
1160 
1161 /* create the send and receive buffer for an SMC socket;
1162  * receive buffers are called RMBs;
1163  * (even though the SMC protocol allows more than one RMB-element per RMB,
1164  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
1165  * extra RMB for every connection in a link group
1166  */
1167 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
1168 {
1169 	int rc;
1170 
1171 	/* create send buffer */
1172 	rc = __smc_buf_create(smc, is_smcd, false);
1173 	if (rc)
1174 		return rc;
1175 	/* create rmb */
1176 	rc = __smc_buf_create(smc, is_smcd, true);
1177 	if (rc)
1178 		smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
1179 	return rc;
1180 }
1181 
1182 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
1183 {
1184 	int i;
1185 
1186 	for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
1187 		if (!test_and_set_bit(i, lgr->rtokens_used_mask))
1188 			return i;
1189 	}
1190 	return -ENOSPC;
1191 }
1192 
1193 /* add a new rtoken from peer */
1194 int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey)
1195 {
1196 	u64 dma_addr = be64_to_cpu(nw_vaddr);
1197 	u32 rkey = ntohl(nw_rkey);
1198 	int i;
1199 
1200 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1201 		if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) &&
1202 		    (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) &&
1203 		    test_bit(i, lgr->rtokens_used_mask)) {
1204 			/* already in list */
1205 			return i;
1206 		}
1207 	}
1208 	i = smc_rmb_reserve_rtoken_idx(lgr);
1209 	if (i < 0)
1210 		return i;
1211 	lgr->rtokens[i][SMC_SINGLE_LINK].rkey = rkey;
1212 	lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = dma_addr;
1213 	return i;
1214 }
1215 
1216 /* delete an rtoken */
1217 int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey)
1218 {
1219 	u32 rkey = ntohl(nw_rkey);
1220 	int i;
1221 
1222 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1223 		if (lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey &&
1224 		    test_bit(i, lgr->rtokens_used_mask)) {
1225 			lgr->rtokens[i][SMC_SINGLE_LINK].rkey = 0;
1226 			lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = 0;
1227 
1228 			clear_bit(i, lgr->rtokens_used_mask);
1229 			return 0;
1230 		}
1231 	}
1232 	return -ENOENT;
1233 }
1234 
1235 /* save rkey and dma_addr received from peer during clc handshake */
1236 int smc_rmb_rtoken_handling(struct smc_connection *conn,
1237 			    struct smc_clc_msg_accept_confirm *clc)
1238 {
1239 	conn->rtoken_idx = smc_rtoken_add(conn->lgr, clc->rmb_dma_addr,
1240 					  clc->rmb_rkey);
1241 	if (conn->rtoken_idx < 0)
1242 		return conn->rtoken_idx;
1243 	return 0;
1244 }
1245 
1246 static void smc_core_going_away(void)
1247 {
1248 	struct smc_ib_device *smcibdev;
1249 	struct smcd_dev *smcd;
1250 
1251 	spin_lock(&smc_ib_devices.lock);
1252 	list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
1253 		int i;
1254 
1255 		for (i = 0; i < SMC_MAX_PORTS; i++)
1256 			set_bit(i, smcibdev->ports_going_away);
1257 	}
1258 	spin_unlock(&smc_ib_devices.lock);
1259 
1260 	spin_lock(&smcd_dev_list.lock);
1261 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1262 		smcd->going_away = 1;
1263 	}
1264 	spin_unlock(&smcd_dev_list.lock);
1265 }
1266 
1267 /* Clean up all SMC link groups */
1268 static void smc_lgrs_shutdown(void)
1269 {
1270 	struct smcd_dev *smcd;
1271 
1272 	smc_core_going_away();
1273 
1274 	smc_smcr_terminate_all(NULL);
1275 
1276 	spin_lock(&smcd_dev_list.lock);
1277 	list_for_each_entry(smcd, &smcd_dev_list.list, list)
1278 		smc_smcd_terminate_all(smcd);
1279 	spin_unlock(&smcd_dev_list.lock);
1280 }
1281 
1282 static int smc_core_reboot_event(struct notifier_block *this,
1283 				 unsigned long event, void *ptr)
1284 {
1285 	smc_lgrs_shutdown();
1286 	smc_ib_unregister_client();
1287 	return 0;
1288 }
1289 
1290 static struct notifier_block smc_reboot_notifier = {
1291 	.notifier_call = smc_core_reboot_event,
1292 };
1293 
1294 int __init smc_core_init(void)
1295 {
1296 	return register_reboot_notifier(&smc_reboot_notifier);
1297 }
1298 
1299 /* Called (from smc_exit) when module is removed */
1300 void smc_core_exit(void)
1301 {
1302 	unregister_reboot_notifier(&smc_reboot_notifier);
1303 	smc_lgrs_shutdown();
1304 }
1305