xref: /openbmc/linux/net/smc/smc_llc.c (revision e9088629)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  Link Layer Control (LLC)
6  *
7  *  Copyright IBM Corp. 2016
8  *
9  *  Author(s):  Klaus Wacker <Klaus.Wacker@de.ibm.com>
10  *              Ursula Braun <ubraun@linux.vnet.ibm.com>
11  */
12 
13 #include <net/tcp.h>
14 #include <rdma/ib_verbs.h>
15 
16 #include "smc.h"
17 #include "smc_core.h"
18 #include "smc_clc.h"
19 #include "smc_llc.h"
20 #include "smc_pnet.h"
21 
22 #define SMC_LLC_DATA_LEN		40
23 
24 struct smc_llc_hdr {
25 	struct smc_wr_rx_hdr common;
26 	union {
27 		struct {
28 			u8 length;	/* 44 */
29 	#if defined(__BIG_ENDIAN_BITFIELD)
30 			u8 reserved:4,
31 			   add_link_rej_rsn:4;
32 #elif defined(__LITTLE_ENDIAN_BITFIELD)
33 			u8 add_link_rej_rsn:4,
34 			   reserved:4;
35 #endif
36 		};
37 		u16 length_v2;	/* 44 - 8192*/
38 	};
39 	u8 flags;
40 } __packed;		/* format defined in
41 			 * IBM Shared Memory Communications Version 2
42 			 * (https://www.ibm.com/support/pages/node/6326337)
43 			 */
44 
45 #define SMC_LLC_FLAG_NO_RMBE_EYEC	0x03
46 
47 struct smc_llc_msg_confirm_link {	/* type 0x01 */
48 	struct smc_llc_hdr hd;
49 	u8 sender_mac[ETH_ALEN];
50 	u8 sender_gid[SMC_GID_SIZE];
51 	u8 sender_qp_num[3];
52 	u8 link_num;
53 	u8 link_uid[SMC_LGR_ID_SIZE];
54 	u8 max_links;
55 	u8 reserved[9];
56 };
57 
58 #define SMC_LLC_FLAG_ADD_LNK_REJ	0x40
59 #define SMC_LLC_REJ_RSN_NO_ALT_PATH	1
60 
61 #define SMC_LLC_ADD_LNK_MAX_LINKS	2
62 
63 struct smc_llc_msg_add_link {		/* type 0x02 */
64 	struct smc_llc_hdr hd;
65 	u8 sender_mac[ETH_ALEN];
66 	u8 reserved2[2];
67 	u8 sender_gid[SMC_GID_SIZE];
68 	u8 sender_qp_num[3];
69 	u8 link_num;
70 #if defined(__BIG_ENDIAN_BITFIELD)
71 	u8 reserved3 : 4,
72 	   qp_mtu   : 4;
73 #elif defined(__LITTLE_ENDIAN_BITFIELD)
74 	u8 qp_mtu   : 4,
75 	   reserved3 : 4;
76 #endif
77 	u8 initial_psn[3];
78 	u8 reserved[8];
79 };
80 
81 struct smc_llc_msg_add_link_cont_rt {
82 	__be32 rmb_key;
83 	__be32 rmb_key_new;
84 	__be64 rmb_vaddr_new;
85 };
86 
87 struct smc_llc_msg_add_link_v2_ext {
88 #if defined(__BIG_ENDIAN_BITFIELD)
89 	u8 v2_direct : 1,
90 	   reserved  : 7;
91 #elif defined(__LITTLE_ENDIAN_BITFIELD)
92 	u8 reserved  : 7,
93 	   v2_direct : 1;
94 #endif
95 	u8 reserved2;
96 	u8 client_target_gid[SMC_GID_SIZE];
97 	u8 reserved3[8];
98 	u16 num_rkeys;
99 	struct smc_llc_msg_add_link_cont_rt rt[];
100 } __packed;		/* format defined in
101 			 * IBM Shared Memory Communications Version 2
102 			 * (https://www.ibm.com/support/pages/node/6326337)
103 			 */
104 
105 struct smc_llc_msg_req_add_link_v2 {
106 	struct smc_llc_hdr hd;
107 	u8 reserved[20];
108 	u8 gid_cnt;
109 	u8 reserved2[3];
110 	u8 gid[][SMC_GID_SIZE];
111 };
112 
113 #define SMC_LLC_RKEYS_PER_CONT_MSG	2
114 
115 struct smc_llc_msg_add_link_cont {	/* type 0x03 */
116 	struct smc_llc_hdr hd;
117 	u8 link_num;
118 	u8 num_rkeys;
119 	u8 reserved2[2];
120 	struct smc_llc_msg_add_link_cont_rt rt[SMC_LLC_RKEYS_PER_CONT_MSG];
121 	u8 reserved[4];
122 } __packed;			/* format defined in RFC7609 */
123 
124 #define SMC_LLC_FLAG_DEL_LINK_ALL	0x40
125 #define SMC_LLC_FLAG_DEL_LINK_ORDERLY	0x20
126 
127 struct smc_llc_msg_del_link {		/* type 0x04 */
128 	struct smc_llc_hdr hd;
129 	u8 link_num;
130 	__be32 reason;
131 	u8 reserved[35];
132 } __packed;			/* format defined in RFC7609 */
133 
134 struct smc_llc_msg_test_link {		/* type 0x07 */
135 	struct smc_llc_hdr hd;
136 	u8 user_data[16];
137 	u8 reserved[24];
138 };
139 
140 struct smc_rmb_rtoken {
141 	union {
142 		u8 num_rkeys;	/* first rtoken byte of CONFIRM LINK msg */
143 				/* is actually the num of rtokens, first */
144 				/* rtoken is always for the current link */
145 		u8 link_id;	/* link id of the rtoken */
146 	};
147 	__be32 rmb_key;
148 	__be64 rmb_vaddr;
149 } __packed;			/* format defined in RFC7609 */
150 
151 #define SMC_LLC_RKEYS_PER_MSG		3
152 #define SMC_LLC_RKEYS_PER_MSG_V2	255
153 
154 struct smc_llc_msg_confirm_rkey {	/* type 0x06 */
155 	struct smc_llc_hdr hd;
156 	struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
157 	u8 reserved;
158 };
159 
160 #define SMC_LLC_DEL_RKEY_MAX	8
161 #define SMC_LLC_FLAG_RKEY_RETRY	0x10
162 #define SMC_LLC_FLAG_RKEY_NEG	0x20
163 
164 struct smc_llc_msg_delete_rkey {	/* type 0x09 */
165 	struct smc_llc_hdr hd;
166 	u8 num_rkeys;
167 	u8 err_mask;
168 	u8 reserved[2];
169 	__be32 rkey[8];
170 	u8 reserved2[4];
171 };
172 
173 struct smc_llc_msg_delete_rkey_v2 {	/* type 0x29 */
174 	struct smc_llc_hdr hd;
175 	u8 num_rkeys;
176 	u8 num_inval_rkeys;
177 	u8 reserved[2];
178 	__be32 rkey[];
179 };
180 
181 union smc_llc_msg {
182 	struct smc_llc_msg_confirm_link confirm_link;
183 	struct smc_llc_msg_add_link add_link;
184 	struct smc_llc_msg_req_add_link_v2 req_add_link;
185 	struct smc_llc_msg_add_link_cont add_link_cont;
186 	struct smc_llc_msg_del_link delete_link;
187 
188 	struct smc_llc_msg_confirm_rkey confirm_rkey;
189 	struct smc_llc_msg_delete_rkey delete_rkey;
190 
191 	struct smc_llc_msg_test_link test_link;
192 	struct {
193 		struct smc_llc_hdr hdr;
194 		u8 data[SMC_LLC_DATA_LEN];
195 	} raw;
196 };
197 
198 #define SMC_LLC_FLAG_RESP		0x80
199 
200 struct smc_llc_qentry {
201 	struct list_head list;
202 	struct smc_link *link;
203 	union smc_llc_msg msg;
204 };
205 
206 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc);
207 
208 struct smc_llc_qentry *smc_llc_flow_qentry_clr(struct smc_llc_flow *flow)
209 {
210 	struct smc_llc_qentry *qentry = flow->qentry;
211 
212 	flow->qentry = NULL;
213 	return qentry;
214 }
215 
216 void smc_llc_flow_qentry_del(struct smc_llc_flow *flow)
217 {
218 	struct smc_llc_qentry *qentry;
219 
220 	if (flow->qentry) {
221 		qentry = flow->qentry;
222 		flow->qentry = NULL;
223 		kfree(qentry);
224 	}
225 }
226 
227 static inline void smc_llc_flow_qentry_set(struct smc_llc_flow *flow,
228 					   struct smc_llc_qentry *qentry)
229 {
230 	flow->qentry = qentry;
231 }
232 
233 static void smc_llc_flow_parallel(struct smc_link_group *lgr, u8 flow_type,
234 				  struct smc_llc_qentry *qentry)
235 {
236 	u8 msg_type = qentry->msg.raw.hdr.common.llc_type;
237 
238 	if ((msg_type == SMC_LLC_ADD_LINK || msg_type == SMC_LLC_DELETE_LINK) &&
239 	    flow_type != msg_type && !lgr->delayed_event) {
240 		lgr->delayed_event = qentry;
241 		return;
242 	}
243 	/* drop parallel or already-in-progress llc requests */
244 	if (flow_type != msg_type)
245 		pr_warn_once("smc: SMC-R lg %*phN net %llu dropped parallel "
246 			     "LLC msg: msg %d flow %d role %d\n",
247 			     SMC_LGR_ID_SIZE, &lgr->id,
248 			     lgr->net->net_cookie,
249 			     qentry->msg.raw.hdr.common.type,
250 			     flow_type, lgr->role);
251 	kfree(qentry);
252 }
253 
254 /* try to start a new llc flow, initiated by an incoming llc msg */
255 static bool smc_llc_flow_start(struct smc_llc_flow *flow,
256 			       struct smc_llc_qentry *qentry)
257 {
258 	struct smc_link_group *lgr = qentry->link->lgr;
259 
260 	spin_lock_bh(&lgr->llc_flow_lock);
261 	if (flow->type) {
262 		/* a flow is already active */
263 		smc_llc_flow_parallel(lgr, flow->type, qentry);
264 		spin_unlock_bh(&lgr->llc_flow_lock);
265 		return false;
266 	}
267 	switch (qentry->msg.raw.hdr.common.llc_type) {
268 	case SMC_LLC_ADD_LINK:
269 		flow->type = SMC_LLC_FLOW_ADD_LINK;
270 		break;
271 	case SMC_LLC_DELETE_LINK:
272 		flow->type = SMC_LLC_FLOW_DEL_LINK;
273 		break;
274 	case SMC_LLC_CONFIRM_RKEY:
275 	case SMC_LLC_DELETE_RKEY:
276 		flow->type = SMC_LLC_FLOW_RKEY;
277 		break;
278 	default:
279 		flow->type = SMC_LLC_FLOW_NONE;
280 	}
281 	smc_llc_flow_qentry_set(flow, qentry);
282 	spin_unlock_bh(&lgr->llc_flow_lock);
283 	return true;
284 }
285 
286 /* start a new local llc flow, wait till current flow finished */
287 int smc_llc_flow_initiate(struct smc_link_group *lgr,
288 			  enum smc_llc_flowtype type)
289 {
290 	enum smc_llc_flowtype allowed_remote = SMC_LLC_FLOW_NONE;
291 	int rc;
292 
293 	/* all flows except confirm_rkey and delete_rkey are exclusive,
294 	 * confirm/delete rkey flows can run concurrently (local and remote)
295 	 */
296 	if (type == SMC_LLC_FLOW_RKEY)
297 		allowed_remote = SMC_LLC_FLOW_RKEY;
298 again:
299 	if (list_empty(&lgr->list))
300 		return -ENODEV;
301 	spin_lock_bh(&lgr->llc_flow_lock);
302 	if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
303 	    (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
304 	     lgr->llc_flow_rmt.type == allowed_remote)) {
305 		lgr->llc_flow_lcl.type = type;
306 		spin_unlock_bh(&lgr->llc_flow_lock);
307 		return 0;
308 	}
309 	spin_unlock_bh(&lgr->llc_flow_lock);
310 	rc = wait_event_timeout(lgr->llc_flow_waiter, (list_empty(&lgr->list) ||
311 				(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
312 				 (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
313 				  lgr->llc_flow_rmt.type == allowed_remote))),
314 				SMC_LLC_WAIT_TIME * 10);
315 	if (!rc)
316 		return -ETIMEDOUT;
317 	goto again;
318 }
319 
320 /* finish the current llc flow */
321 void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow)
322 {
323 	spin_lock_bh(&lgr->llc_flow_lock);
324 	memset(flow, 0, sizeof(*flow));
325 	flow->type = SMC_LLC_FLOW_NONE;
326 	spin_unlock_bh(&lgr->llc_flow_lock);
327 	if (!list_empty(&lgr->list) && lgr->delayed_event &&
328 	    flow == &lgr->llc_flow_lcl)
329 		schedule_work(&lgr->llc_event_work);
330 	else
331 		wake_up(&lgr->llc_flow_waiter);
332 }
333 
334 /* lnk is optional and used for early wakeup when link goes down, useful in
335  * cases where we wait for a response on the link after we sent a request
336  */
337 struct smc_llc_qentry *smc_llc_wait(struct smc_link_group *lgr,
338 				    struct smc_link *lnk,
339 				    int time_out, u8 exp_msg)
340 {
341 	struct smc_llc_flow *flow = &lgr->llc_flow_lcl;
342 	u8 rcv_msg;
343 
344 	wait_event_timeout(lgr->llc_msg_waiter,
345 			   (flow->qentry ||
346 			    (lnk && !smc_link_usable(lnk)) ||
347 			    list_empty(&lgr->list)),
348 			   time_out);
349 	if (!flow->qentry ||
350 	    (lnk && !smc_link_usable(lnk)) || list_empty(&lgr->list)) {
351 		smc_llc_flow_qentry_del(flow);
352 		goto out;
353 	}
354 	rcv_msg = flow->qentry->msg.raw.hdr.common.llc_type;
355 	if (exp_msg && rcv_msg != exp_msg) {
356 		if (exp_msg == SMC_LLC_ADD_LINK &&
357 		    rcv_msg == SMC_LLC_DELETE_LINK) {
358 			/* flow_start will delay the unexpected msg */
359 			smc_llc_flow_start(&lgr->llc_flow_lcl,
360 					   smc_llc_flow_qentry_clr(flow));
361 			return NULL;
362 		}
363 		pr_warn_once("smc: SMC-R lg %*phN net %llu dropped unexpected LLC msg: "
364 			     "msg %d exp %d flow %d role %d flags %x\n",
365 			     SMC_LGR_ID_SIZE, &lgr->id, lgr->net->net_cookie,
366 			     rcv_msg, exp_msg,
367 			     flow->type, lgr->role,
368 			     flow->qentry->msg.raw.hdr.flags);
369 		smc_llc_flow_qentry_del(flow);
370 	}
371 out:
372 	return flow->qentry;
373 }
374 
375 /********************************** send *************************************/
376 
377 struct smc_llc_tx_pend {
378 };
379 
380 /* handler for send/transmission completion of an LLC msg */
381 static void smc_llc_tx_handler(struct smc_wr_tx_pend_priv *pend,
382 			       struct smc_link *link,
383 			       enum ib_wc_status wc_status)
384 {
385 	/* future work: handle wc_status error for recovery and failover */
386 }
387 
388 /**
389  * smc_llc_add_pending_send() - add LLC control message to pending WQE transmits
390  * @link: Pointer to SMC link used for sending LLC control message.
391  * @wr_buf: Out variable returning pointer to work request payload buffer.
392  * @pend: Out variable returning pointer to private pending WR tracking.
393  *	  It's the context the transmit complete handler will get.
394  *
395  * Reserves and pre-fills an entry for a pending work request send/tx.
396  * Used by mid-level smc_llc_send_msg() to prepare for later actual send/tx.
397  * Can sleep due to smc_get_ctrl_buf (if not in softirq context).
398  *
399  * Return: 0 on success, otherwise an error value.
400  */
401 static int smc_llc_add_pending_send(struct smc_link *link,
402 				    struct smc_wr_buf **wr_buf,
403 				    struct smc_wr_tx_pend_priv **pend)
404 {
405 	int rc;
406 
407 	rc = smc_wr_tx_get_free_slot(link, smc_llc_tx_handler, wr_buf, NULL,
408 				     pend);
409 	if (rc < 0)
410 		return rc;
411 	BUILD_BUG_ON_MSG(
412 		sizeof(union smc_llc_msg) > SMC_WR_BUF_SIZE,
413 		"must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)");
414 	BUILD_BUG_ON_MSG(
415 		sizeof(union smc_llc_msg) != SMC_WR_TX_SIZE,
416 		"must adapt SMC_WR_TX_SIZE to sizeof(struct smc_llc_msg); if not all smc_wr upper layer protocols use the same message size any more, must start to set link->wr_tx_sges[i].length on each individual smc_wr_tx_send()");
417 	BUILD_BUG_ON_MSG(
418 		sizeof(struct smc_llc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
419 		"must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_llc_tx_pend)");
420 	return 0;
421 }
422 
423 static int smc_llc_add_pending_send_v2(struct smc_link *link,
424 				       struct smc_wr_v2_buf **wr_buf,
425 				       struct smc_wr_tx_pend_priv **pend)
426 {
427 	int rc;
428 
429 	rc = smc_wr_tx_get_v2_slot(link, smc_llc_tx_handler, wr_buf, pend);
430 	if (rc < 0)
431 		return rc;
432 	return 0;
433 }
434 
435 static void smc_llc_init_msg_hdr(struct smc_llc_hdr *hdr,
436 				 struct smc_link_group *lgr, size_t len)
437 {
438 	if (lgr->smc_version == SMC_V2) {
439 		hdr->common.llc_version = SMC_V2;
440 		hdr->length_v2 = len;
441 	} else {
442 		hdr->common.llc_version = 0;
443 		hdr->length = len;
444 	}
445 }
446 
447 /* high-level API to send LLC confirm link */
448 int smc_llc_send_confirm_link(struct smc_link *link,
449 			      enum smc_llc_reqresp reqresp)
450 {
451 	struct smc_llc_msg_confirm_link *confllc;
452 	struct smc_wr_tx_pend_priv *pend;
453 	struct smc_wr_buf *wr_buf;
454 	int rc;
455 
456 	if (!smc_wr_tx_link_hold(link))
457 		return -ENOLINK;
458 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
459 	if (rc)
460 		goto put_out;
461 	confllc = (struct smc_llc_msg_confirm_link *)wr_buf;
462 	memset(confllc, 0, sizeof(*confllc));
463 	confllc->hd.common.llc_type = SMC_LLC_CONFIRM_LINK;
464 	smc_llc_init_msg_hdr(&confllc->hd, link->lgr, sizeof(*confllc));
465 	confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
466 	if (reqresp == SMC_LLC_RESP)
467 		confllc->hd.flags |= SMC_LLC_FLAG_RESP;
468 	memcpy(confllc->sender_mac, link->smcibdev->mac[link->ibport - 1],
469 	       ETH_ALEN);
470 	memcpy(confllc->sender_gid, link->gid, SMC_GID_SIZE);
471 	hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
472 	confllc->link_num = link->link_id;
473 	memcpy(confllc->link_uid, link->link_uid, SMC_LGR_ID_SIZE);
474 	confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS;
475 	/* send llc message */
476 	rc = smc_wr_tx_send(link, pend);
477 put_out:
478 	smc_wr_tx_link_put(link);
479 	return rc;
480 }
481 
482 /* send LLC confirm rkey request */
483 static int smc_llc_send_confirm_rkey(struct smc_link *send_link,
484 				     struct smc_buf_desc *rmb_desc)
485 {
486 	struct smc_llc_msg_confirm_rkey *rkeyllc;
487 	struct smc_wr_tx_pend_priv *pend;
488 	struct smc_wr_buf *wr_buf;
489 	struct smc_link *link;
490 	int i, rc, rtok_ix;
491 
492 	if (!smc_wr_tx_link_hold(send_link))
493 		return -ENOLINK;
494 	rc = smc_llc_add_pending_send(send_link, &wr_buf, &pend);
495 	if (rc)
496 		goto put_out;
497 	rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf;
498 	memset(rkeyllc, 0, sizeof(*rkeyllc));
499 	rkeyllc->hd.common.llc_type = SMC_LLC_CONFIRM_RKEY;
500 	smc_llc_init_msg_hdr(&rkeyllc->hd, send_link->lgr, sizeof(*rkeyllc));
501 
502 	rtok_ix = 1;
503 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
504 		link = &send_link->lgr->lnk[i];
505 		if (smc_link_active(link) && link != send_link) {
506 			rkeyllc->rtoken[rtok_ix].link_id = link->link_id;
507 			rkeyllc->rtoken[rtok_ix].rmb_key =
508 				htonl(rmb_desc->mr_rx[link->link_idx]->rkey);
509 			rkeyllc->rtoken[rtok_ix].rmb_vaddr = cpu_to_be64(
510 				(u64)sg_dma_address(
511 					rmb_desc->sgt[link->link_idx].sgl));
512 			rtok_ix++;
513 		}
514 	}
515 	/* rkey of send_link is in rtoken[0] */
516 	rkeyllc->rtoken[0].num_rkeys = rtok_ix - 1;
517 	rkeyllc->rtoken[0].rmb_key =
518 		htonl(rmb_desc->mr_rx[send_link->link_idx]->rkey);
519 	rkeyllc->rtoken[0].rmb_vaddr = cpu_to_be64(
520 		(u64)sg_dma_address(rmb_desc->sgt[send_link->link_idx].sgl));
521 	/* send llc message */
522 	rc = smc_wr_tx_send(send_link, pend);
523 put_out:
524 	smc_wr_tx_link_put(send_link);
525 	return rc;
526 }
527 
528 /* send LLC delete rkey request */
529 static int smc_llc_send_delete_rkey(struct smc_link *link,
530 				    struct smc_buf_desc *rmb_desc)
531 {
532 	struct smc_llc_msg_delete_rkey *rkeyllc;
533 	struct smc_wr_tx_pend_priv *pend;
534 	struct smc_wr_buf *wr_buf;
535 	int rc;
536 
537 	if (!smc_wr_tx_link_hold(link))
538 		return -ENOLINK;
539 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
540 	if (rc)
541 		goto put_out;
542 	rkeyllc = (struct smc_llc_msg_delete_rkey *)wr_buf;
543 	memset(rkeyllc, 0, sizeof(*rkeyllc));
544 	rkeyllc->hd.common.llc_type = SMC_LLC_DELETE_RKEY;
545 	smc_llc_init_msg_hdr(&rkeyllc->hd, link->lgr, sizeof(*rkeyllc));
546 	rkeyllc->num_rkeys = 1;
547 	rkeyllc->rkey[0] = htonl(rmb_desc->mr_rx[link->link_idx]->rkey);
548 	/* send llc message */
549 	rc = smc_wr_tx_send(link, pend);
550 put_out:
551 	smc_wr_tx_link_put(link);
552 	return rc;
553 }
554 
555 /* return first buffer from any of the next buf lists */
556 static struct smc_buf_desc *_smc_llc_get_next_rmb(struct smc_link_group *lgr,
557 						  int *buf_lst)
558 {
559 	struct smc_buf_desc *buf_pos;
560 
561 	while (*buf_lst < SMC_RMBE_SIZES) {
562 		buf_pos = list_first_entry_or_null(&lgr->rmbs[*buf_lst],
563 						   struct smc_buf_desc, list);
564 		if (buf_pos)
565 			return buf_pos;
566 		(*buf_lst)++;
567 	}
568 	return NULL;
569 }
570 
571 /* return next rmb from buffer lists */
572 static struct smc_buf_desc *smc_llc_get_next_rmb(struct smc_link_group *lgr,
573 						 int *buf_lst,
574 						 struct smc_buf_desc *buf_pos)
575 {
576 	struct smc_buf_desc *buf_next;
577 
578 	if (!buf_pos || list_is_last(&buf_pos->list, &lgr->rmbs[*buf_lst])) {
579 		(*buf_lst)++;
580 		return _smc_llc_get_next_rmb(lgr, buf_lst);
581 	}
582 	buf_next = list_next_entry(buf_pos, list);
583 	return buf_next;
584 }
585 
586 static struct smc_buf_desc *smc_llc_get_first_rmb(struct smc_link_group *lgr,
587 						  int *buf_lst)
588 {
589 	*buf_lst = 0;
590 	return smc_llc_get_next_rmb(lgr, buf_lst, NULL);
591 }
592 
593 static int smc_llc_fill_ext_v2(struct smc_llc_msg_add_link_v2_ext *ext,
594 			       struct smc_link *link, struct smc_link *link_new)
595 {
596 	struct smc_link_group *lgr = link->lgr;
597 	struct smc_buf_desc *buf_pos;
598 	int prim_lnk_idx, lnk_idx, i;
599 	struct smc_buf_desc *rmb;
600 	int len = sizeof(*ext);
601 	int buf_lst;
602 
603 	ext->v2_direct = !lgr->uses_gateway;
604 	memcpy(ext->client_target_gid, link_new->gid, SMC_GID_SIZE);
605 
606 	prim_lnk_idx = link->link_idx;
607 	lnk_idx = link_new->link_idx;
608 	mutex_lock(&lgr->rmbs_lock);
609 	ext->num_rkeys = lgr->conns_num;
610 	if (!ext->num_rkeys)
611 		goto out;
612 	buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
613 	for (i = 0; i < ext->num_rkeys; i++) {
614 		if (!buf_pos)
615 			break;
616 		rmb = buf_pos;
617 		ext->rt[i].rmb_key = htonl(rmb->mr_rx[prim_lnk_idx]->rkey);
618 		ext->rt[i].rmb_key_new = htonl(rmb->mr_rx[lnk_idx]->rkey);
619 		ext->rt[i].rmb_vaddr_new =
620 			cpu_to_be64((u64)sg_dma_address(rmb->sgt[lnk_idx].sgl));
621 		buf_pos = smc_llc_get_next_rmb(lgr, &buf_lst, buf_pos);
622 		while (buf_pos && !(buf_pos)->used)
623 			buf_pos = smc_llc_get_next_rmb(lgr, &buf_lst, buf_pos);
624 	}
625 	len += i * sizeof(ext->rt[0]);
626 out:
627 	mutex_unlock(&lgr->rmbs_lock);
628 	return len;
629 }
630 
631 /* send ADD LINK request or response */
632 int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[],
633 			  struct smc_link *link_new,
634 			  enum smc_llc_reqresp reqresp)
635 {
636 	struct smc_llc_msg_add_link_v2_ext *ext = NULL;
637 	struct smc_llc_msg_add_link *addllc;
638 	struct smc_wr_tx_pend_priv *pend;
639 	int len = sizeof(*addllc);
640 	int rc;
641 
642 	if (!smc_wr_tx_link_hold(link))
643 		return -ENOLINK;
644 	if (link->lgr->smc_version == SMC_V2) {
645 		struct smc_wr_v2_buf *wr_buf;
646 
647 		rc = smc_llc_add_pending_send_v2(link, &wr_buf, &pend);
648 		if (rc)
649 			goto put_out;
650 		addllc = (struct smc_llc_msg_add_link *)wr_buf;
651 		ext = (struct smc_llc_msg_add_link_v2_ext *)
652 						&wr_buf->raw[sizeof(*addllc)];
653 		memset(ext, 0, SMC_WR_TX_SIZE);
654 	} else {
655 		struct smc_wr_buf *wr_buf;
656 
657 		rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
658 		if (rc)
659 			goto put_out;
660 		addllc = (struct smc_llc_msg_add_link *)wr_buf;
661 	}
662 
663 	memset(addllc, 0, sizeof(*addllc));
664 	addllc->hd.common.llc_type = SMC_LLC_ADD_LINK;
665 	if (reqresp == SMC_LLC_RESP)
666 		addllc->hd.flags |= SMC_LLC_FLAG_RESP;
667 	memcpy(addllc->sender_mac, mac, ETH_ALEN);
668 	memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
669 	if (link_new) {
670 		addllc->link_num = link_new->link_id;
671 		hton24(addllc->sender_qp_num, link_new->roce_qp->qp_num);
672 		hton24(addllc->initial_psn, link_new->psn_initial);
673 		if (reqresp == SMC_LLC_REQ)
674 			addllc->qp_mtu = link_new->path_mtu;
675 		else
676 			addllc->qp_mtu = min(link_new->path_mtu,
677 					     link_new->peer_mtu);
678 	}
679 	if (ext && link_new)
680 		len += smc_llc_fill_ext_v2(ext, link, link_new);
681 	smc_llc_init_msg_hdr(&addllc->hd, link->lgr, len);
682 	/* send llc message */
683 	if (link->lgr->smc_version == SMC_V2)
684 		rc = smc_wr_tx_v2_send(link, pend, len);
685 	else
686 		rc = smc_wr_tx_send(link, pend);
687 put_out:
688 	smc_wr_tx_link_put(link);
689 	return rc;
690 }
691 
692 /* send DELETE LINK request or response */
693 int smc_llc_send_delete_link(struct smc_link *link, u8 link_del_id,
694 			     enum smc_llc_reqresp reqresp, bool orderly,
695 			     u32 reason)
696 {
697 	struct smc_llc_msg_del_link *delllc;
698 	struct smc_wr_tx_pend_priv *pend;
699 	struct smc_wr_buf *wr_buf;
700 	int rc;
701 
702 	if (!smc_wr_tx_link_hold(link))
703 		return -ENOLINK;
704 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
705 	if (rc)
706 		goto put_out;
707 	delllc = (struct smc_llc_msg_del_link *)wr_buf;
708 
709 	memset(delllc, 0, sizeof(*delllc));
710 	delllc->hd.common.llc_type = SMC_LLC_DELETE_LINK;
711 	smc_llc_init_msg_hdr(&delllc->hd, link->lgr, sizeof(*delllc));
712 	if (reqresp == SMC_LLC_RESP)
713 		delllc->hd.flags |= SMC_LLC_FLAG_RESP;
714 	if (orderly)
715 		delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
716 	if (link_del_id)
717 		delllc->link_num = link_del_id;
718 	else
719 		delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
720 	delllc->reason = htonl(reason);
721 	/* send llc message */
722 	rc = smc_wr_tx_send(link, pend);
723 put_out:
724 	smc_wr_tx_link_put(link);
725 	return rc;
726 }
727 
728 /* send LLC test link request */
729 static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
730 {
731 	struct smc_llc_msg_test_link *testllc;
732 	struct smc_wr_tx_pend_priv *pend;
733 	struct smc_wr_buf *wr_buf;
734 	int rc;
735 
736 	if (!smc_wr_tx_link_hold(link))
737 		return -ENOLINK;
738 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
739 	if (rc)
740 		goto put_out;
741 	testllc = (struct smc_llc_msg_test_link *)wr_buf;
742 	memset(testllc, 0, sizeof(*testllc));
743 	testllc->hd.common.llc_type = SMC_LLC_TEST_LINK;
744 	smc_llc_init_msg_hdr(&testllc->hd, link->lgr, sizeof(*testllc));
745 	memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
746 	/* send llc message */
747 	rc = smc_wr_tx_send(link, pend);
748 put_out:
749 	smc_wr_tx_link_put(link);
750 	return rc;
751 }
752 
753 /* schedule an llc send on link, may wait for buffers */
754 static int smc_llc_send_message(struct smc_link *link, void *llcbuf)
755 {
756 	struct smc_wr_tx_pend_priv *pend;
757 	struct smc_wr_buf *wr_buf;
758 	int rc;
759 
760 	if (!smc_wr_tx_link_hold(link))
761 		return -ENOLINK;
762 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
763 	if (rc)
764 		goto put_out;
765 	memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
766 	rc = smc_wr_tx_send(link, pend);
767 put_out:
768 	smc_wr_tx_link_put(link);
769 	return rc;
770 }
771 
772 /* schedule an llc send on link, may wait for buffers,
773  * and wait for send completion notification.
774  * @return 0 on success
775  */
776 static int smc_llc_send_message_wait(struct smc_link *link, void *llcbuf)
777 {
778 	struct smc_wr_tx_pend_priv *pend;
779 	struct smc_wr_buf *wr_buf;
780 	int rc;
781 
782 	if (!smc_wr_tx_link_hold(link))
783 		return -ENOLINK;
784 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
785 	if (rc)
786 		goto put_out;
787 	memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
788 	rc = smc_wr_tx_send_wait(link, pend, SMC_LLC_WAIT_TIME);
789 put_out:
790 	smc_wr_tx_link_put(link);
791 	return rc;
792 }
793 
794 /********************************* receive ***********************************/
795 
796 static int smc_llc_alloc_alt_link(struct smc_link_group *lgr,
797 				  enum smc_lgr_type lgr_new_t)
798 {
799 	int i;
800 
801 	if (lgr->type == SMC_LGR_SYMMETRIC ||
802 	    (lgr->type != SMC_LGR_SINGLE &&
803 	     (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
804 	      lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)))
805 		return -EMLINK;
806 
807 	if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
808 	    lgr_new_t == SMC_LGR_ASYMMETRIC_PEER) {
809 		for (i = SMC_LINKS_PER_LGR_MAX - 1; i >= 0; i--)
810 			if (lgr->lnk[i].state == SMC_LNK_UNUSED)
811 				return i;
812 	} else {
813 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
814 			if (lgr->lnk[i].state == SMC_LNK_UNUSED)
815 				return i;
816 	}
817 	return -EMLINK;
818 }
819 
820 /* send one add_link_continue msg */
821 static int smc_llc_add_link_cont(struct smc_link *link,
822 				 struct smc_link *link_new, u8 *num_rkeys_todo,
823 				 int *buf_lst, struct smc_buf_desc **buf_pos)
824 {
825 	struct smc_llc_msg_add_link_cont *addc_llc;
826 	struct smc_link_group *lgr = link->lgr;
827 	int prim_lnk_idx, lnk_idx, i, rc;
828 	struct smc_wr_tx_pend_priv *pend;
829 	struct smc_wr_buf *wr_buf;
830 	struct smc_buf_desc *rmb;
831 	u8 n;
832 
833 	if (!smc_wr_tx_link_hold(link))
834 		return -ENOLINK;
835 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
836 	if (rc)
837 		goto put_out;
838 	addc_llc = (struct smc_llc_msg_add_link_cont *)wr_buf;
839 	memset(addc_llc, 0, sizeof(*addc_llc));
840 
841 	prim_lnk_idx = link->link_idx;
842 	lnk_idx = link_new->link_idx;
843 	addc_llc->link_num = link_new->link_id;
844 	addc_llc->num_rkeys = *num_rkeys_todo;
845 	n = *num_rkeys_todo;
846 	for (i = 0; i < min_t(u8, n, SMC_LLC_RKEYS_PER_CONT_MSG); i++) {
847 		if (!*buf_pos) {
848 			addc_llc->num_rkeys = addc_llc->num_rkeys -
849 					      *num_rkeys_todo;
850 			*num_rkeys_todo = 0;
851 			break;
852 		}
853 		rmb = *buf_pos;
854 
855 		addc_llc->rt[i].rmb_key = htonl(rmb->mr_rx[prim_lnk_idx]->rkey);
856 		addc_llc->rt[i].rmb_key_new = htonl(rmb->mr_rx[lnk_idx]->rkey);
857 		addc_llc->rt[i].rmb_vaddr_new =
858 			cpu_to_be64((u64)sg_dma_address(rmb->sgt[lnk_idx].sgl));
859 
860 		(*num_rkeys_todo)--;
861 		*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
862 		while (*buf_pos && !(*buf_pos)->used)
863 			*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
864 	}
865 	addc_llc->hd.common.llc_type = SMC_LLC_ADD_LINK_CONT;
866 	addc_llc->hd.length = sizeof(struct smc_llc_msg_add_link_cont);
867 	if (lgr->role == SMC_CLNT)
868 		addc_llc->hd.flags |= SMC_LLC_FLAG_RESP;
869 	rc = smc_wr_tx_send(link, pend);
870 put_out:
871 	smc_wr_tx_link_put(link);
872 	return rc;
873 }
874 
875 static int smc_llc_cli_rkey_exchange(struct smc_link *link,
876 				     struct smc_link *link_new)
877 {
878 	struct smc_llc_msg_add_link_cont *addc_llc;
879 	struct smc_link_group *lgr = link->lgr;
880 	u8 max, num_rkeys_send, num_rkeys_recv;
881 	struct smc_llc_qentry *qentry;
882 	struct smc_buf_desc *buf_pos;
883 	int buf_lst;
884 	int rc = 0;
885 	int i;
886 
887 	mutex_lock(&lgr->rmbs_lock);
888 	num_rkeys_send = lgr->conns_num;
889 	buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
890 	do {
891 		qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_TIME,
892 				      SMC_LLC_ADD_LINK_CONT);
893 		if (!qentry) {
894 			rc = -ETIMEDOUT;
895 			break;
896 		}
897 		addc_llc = &qentry->msg.add_link_cont;
898 		num_rkeys_recv = addc_llc->num_rkeys;
899 		max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
900 		for (i = 0; i < max; i++) {
901 			smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
902 				       addc_llc->rt[i].rmb_key,
903 				       addc_llc->rt[i].rmb_vaddr_new,
904 				       addc_llc->rt[i].rmb_key_new);
905 			num_rkeys_recv--;
906 		}
907 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
908 		rc = smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
909 					   &buf_lst, &buf_pos);
910 		if (rc)
911 			break;
912 	} while (num_rkeys_send || num_rkeys_recv);
913 
914 	mutex_unlock(&lgr->rmbs_lock);
915 	return rc;
916 }
917 
918 /* prepare and send an add link reject response */
919 static int smc_llc_cli_add_link_reject(struct smc_llc_qentry *qentry)
920 {
921 	qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
922 	qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_ADD_LNK_REJ;
923 	qentry->msg.raw.hdr.add_link_rej_rsn = SMC_LLC_REJ_RSN_NO_ALT_PATH;
924 	smc_llc_init_msg_hdr(&qentry->msg.raw.hdr, qentry->link->lgr,
925 			     sizeof(qentry->msg));
926 	return smc_llc_send_message(qentry->link, &qentry->msg);
927 }
928 
929 static int smc_llc_cli_conf_link(struct smc_link *link,
930 				 struct smc_init_info *ini,
931 				 struct smc_link *link_new,
932 				 enum smc_lgr_type lgr_new_t)
933 {
934 	struct smc_link_group *lgr = link->lgr;
935 	struct smc_llc_qentry *qentry = NULL;
936 	int rc = 0;
937 
938 	/* receive CONFIRM LINK request over RoCE fabric */
939 	qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_FIRST_TIME, 0);
940 	if (!qentry) {
941 		rc = smc_llc_send_delete_link(link, link_new->link_id,
942 					      SMC_LLC_REQ, false,
943 					      SMC_LLC_DEL_LOST_PATH);
944 		return -ENOLINK;
945 	}
946 	if (qentry->msg.raw.hdr.common.llc_type != SMC_LLC_CONFIRM_LINK) {
947 		/* received DELETE_LINK instead */
948 		qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
949 		smc_llc_send_message(link, &qentry->msg);
950 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
951 		return -ENOLINK;
952 	}
953 	smc_llc_save_peer_uid(qentry);
954 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
955 
956 	rc = smc_ib_modify_qp_rts(link_new);
957 	if (rc) {
958 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
959 					 false, SMC_LLC_DEL_LOST_PATH);
960 		return -ENOLINK;
961 	}
962 	smc_wr_remember_qp_attr(link_new);
963 
964 	rc = smcr_buf_reg_lgr(link_new);
965 	if (rc) {
966 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
967 					 false, SMC_LLC_DEL_LOST_PATH);
968 		return -ENOLINK;
969 	}
970 
971 	/* send CONFIRM LINK response over RoCE fabric */
972 	rc = smc_llc_send_confirm_link(link_new, SMC_LLC_RESP);
973 	if (rc) {
974 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
975 					 false, SMC_LLC_DEL_LOST_PATH);
976 		return -ENOLINK;
977 	}
978 	smc_llc_link_active(link_new);
979 	if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
980 	    lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
981 		smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
982 	else
983 		smcr_lgr_set_type(lgr, lgr_new_t);
984 	return 0;
985 }
986 
987 static void smc_llc_save_add_link_rkeys(struct smc_link *link,
988 					struct smc_link *link_new)
989 {
990 	struct smc_llc_msg_add_link_v2_ext *ext;
991 	struct smc_link_group *lgr = link->lgr;
992 	int max, i;
993 
994 	ext = (struct smc_llc_msg_add_link_v2_ext *)((u8 *)lgr->wr_rx_buf_v2 +
995 						     SMC_WR_TX_SIZE);
996 	max = min_t(u8, ext->num_rkeys, SMC_LLC_RKEYS_PER_MSG_V2);
997 	mutex_lock(&lgr->rmbs_lock);
998 	for (i = 0; i < max; i++) {
999 		smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1000 			       ext->rt[i].rmb_key,
1001 			       ext->rt[i].rmb_vaddr_new,
1002 			       ext->rt[i].rmb_key_new);
1003 	}
1004 	mutex_unlock(&lgr->rmbs_lock);
1005 }
1006 
1007 static void smc_llc_save_add_link_info(struct smc_link *link,
1008 				       struct smc_llc_msg_add_link *add_llc)
1009 {
1010 	link->peer_qpn = ntoh24(add_llc->sender_qp_num);
1011 	memcpy(link->peer_gid, add_llc->sender_gid, SMC_GID_SIZE);
1012 	memcpy(link->peer_mac, add_llc->sender_mac, ETH_ALEN);
1013 	link->peer_psn = ntoh24(add_llc->initial_psn);
1014 	link->peer_mtu = add_llc->qp_mtu;
1015 }
1016 
1017 /* as an SMC client, process an add link request */
1018 int smc_llc_cli_add_link(struct smc_link *link, struct smc_llc_qentry *qentry)
1019 {
1020 	struct smc_llc_msg_add_link *llc = &qentry->msg.add_link;
1021 	enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1022 	struct smc_link_group *lgr = smc_get_lgr(link);
1023 	struct smc_init_info *ini = NULL;
1024 	struct smc_link *lnk_new = NULL;
1025 	int lnk_idx, rc = 0;
1026 
1027 	if (!llc->qp_mtu)
1028 		goto out_reject;
1029 
1030 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1031 	if (!ini) {
1032 		rc = -ENOMEM;
1033 		goto out_reject;
1034 	}
1035 
1036 	ini->vlan_id = lgr->vlan_id;
1037 	if (lgr->smc_version == SMC_V2) {
1038 		ini->check_smcrv2 = true;
1039 		ini->smcrv2.saddr = lgr->saddr;
1040 		ini->smcrv2.daddr = smc_ib_gid_to_ipv4(llc->sender_gid);
1041 	}
1042 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1043 	if (!memcmp(llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1044 	    (lgr->smc_version == SMC_V2 ||
1045 	     !memcmp(llc->sender_mac, link->peer_mac, ETH_ALEN))) {
1046 		if (!ini->ib_dev && !ini->smcrv2.ib_dev_v2)
1047 			goto out_reject;
1048 		lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1049 	}
1050 	if (lgr->smc_version == SMC_V2 && !ini->smcrv2.ib_dev_v2) {
1051 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1052 		ini->smcrv2.ib_dev_v2 = link->smcibdev;
1053 		ini->smcrv2.ib_port_v2 = link->ibport;
1054 	} else if (lgr->smc_version < SMC_V2 && !ini->ib_dev) {
1055 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1056 		ini->ib_dev = link->smcibdev;
1057 		ini->ib_port = link->ibport;
1058 	}
1059 	lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1060 	if (lnk_idx < 0)
1061 		goto out_reject;
1062 	lnk_new = &lgr->lnk[lnk_idx];
1063 	rc = smcr_link_init(lgr, lnk_new, lnk_idx, ini);
1064 	if (rc)
1065 		goto out_reject;
1066 	smc_llc_save_add_link_info(lnk_new, llc);
1067 	lnk_new->link_id = llc->link_num;	/* SMC server assigns link id */
1068 	smc_llc_link_set_uid(lnk_new);
1069 
1070 	rc = smc_ib_ready_link(lnk_new);
1071 	if (rc)
1072 		goto out_clear_lnk;
1073 
1074 	rc = smcr_buf_map_lgr(lnk_new);
1075 	if (rc)
1076 		goto out_clear_lnk;
1077 
1078 	rc = smc_llc_send_add_link(link,
1079 				   lnk_new->smcibdev->mac[lnk_new->ibport - 1],
1080 				   lnk_new->gid, lnk_new, SMC_LLC_RESP);
1081 	if (rc)
1082 		goto out_clear_lnk;
1083 	if (lgr->smc_version == SMC_V2) {
1084 		smc_llc_save_add_link_rkeys(link, lnk_new);
1085 	} else {
1086 		rc = smc_llc_cli_rkey_exchange(link, lnk_new);
1087 		if (rc) {
1088 			rc = 0;
1089 			goto out_clear_lnk;
1090 		}
1091 	}
1092 	rc = smc_llc_cli_conf_link(link, ini, lnk_new, lgr_new_t);
1093 	if (!rc)
1094 		goto out;
1095 out_clear_lnk:
1096 	lnk_new->state = SMC_LNK_INACTIVE;
1097 	smcr_link_clear(lnk_new, false);
1098 out_reject:
1099 	smc_llc_cli_add_link_reject(qentry);
1100 out:
1101 	kfree(ini);
1102 	kfree(qentry);
1103 	return rc;
1104 }
1105 
1106 static void smc_llc_send_request_add_link(struct smc_link *link)
1107 {
1108 	struct smc_llc_msg_req_add_link_v2 *llc;
1109 	struct smc_wr_tx_pend_priv *pend;
1110 	struct smc_wr_v2_buf *wr_buf;
1111 	struct smc_gidlist gidlist;
1112 	int rc, len, i;
1113 
1114 	if (!smc_wr_tx_link_hold(link))
1115 		return;
1116 	if (link->lgr->type == SMC_LGR_SYMMETRIC ||
1117 	    link->lgr->type == SMC_LGR_ASYMMETRIC_PEER)
1118 		goto put_out;
1119 
1120 	smc_fill_gid_list(link->lgr, &gidlist, link->smcibdev, link->gid);
1121 	if (gidlist.len <= 1)
1122 		goto put_out;
1123 
1124 	rc = smc_llc_add_pending_send_v2(link, &wr_buf, &pend);
1125 	if (rc)
1126 		goto put_out;
1127 	llc = (struct smc_llc_msg_req_add_link_v2 *)wr_buf;
1128 	memset(llc, 0, SMC_WR_TX_SIZE);
1129 
1130 	llc->hd.common.llc_type = SMC_LLC_REQ_ADD_LINK;
1131 	for (i = 0; i < gidlist.len; i++)
1132 		memcpy(llc->gid[i], gidlist.list[i], sizeof(gidlist.list[0]));
1133 	llc->gid_cnt = gidlist.len;
1134 	len = sizeof(*llc) + (gidlist.len * sizeof(gidlist.list[0]));
1135 	smc_llc_init_msg_hdr(&llc->hd, link->lgr, len);
1136 	rc = smc_wr_tx_v2_send(link, pend, len);
1137 	if (!rc)
1138 		/* set REQ_ADD_LINK flow and wait for response from peer */
1139 		link->lgr->llc_flow_lcl.type = SMC_LLC_FLOW_REQ_ADD_LINK;
1140 put_out:
1141 	smc_wr_tx_link_put(link);
1142 }
1143 
1144 /* as an SMC client, invite server to start the add_link processing */
1145 static void smc_llc_cli_add_link_invite(struct smc_link *link,
1146 					struct smc_llc_qentry *qentry)
1147 {
1148 	struct smc_link_group *lgr = smc_get_lgr(link);
1149 	struct smc_init_info *ini = NULL;
1150 
1151 	if (lgr->smc_version == SMC_V2) {
1152 		smc_llc_send_request_add_link(link);
1153 		goto out;
1154 	}
1155 
1156 	if (lgr->type == SMC_LGR_SYMMETRIC ||
1157 	    lgr->type == SMC_LGR_ASYMMETRIC_PEER)
1158 		goto out;
1159 
1160 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1161 	if (!ini)
1162 		goto out;
1163 
1164 	ini->vlan_id = lgr->vlan_id;
1165 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1166 	if (!ini->ib_dev)
1167 		goto out;
1168 
1169 	smc_llc_send_add_link(link, ini->ib_dev->mac[ini->ib_port - 1],
1170 			      ini->ib_gid, NULL, SMC_LLC_REQ);
1171 out:
1172 	kfree(ini);
1173 	kfree(qentry);
1174 }
1175 
1176 static bool smc_llc_is_empty_llc_message(union smc_llc_msg *llc)
1177 {
1178 	int i;
1179 
1180 	for (i = 0; i < ARRAY_SIZE(llc->raw.data); i++)
1181 		if (llc->raw.data[i])
1182 			return false;
1183 	return true;
1184 }
1185 
1186 static bool smc_llc_is_local_add_link(union smc_llc_msg *llc)
1187 {
1188 	if (llc->raw.hdr.common.llc_type == SMC_LLC_ADD_LINK &&
1189 	    smc_llc_is_empty_llc_message(llc))
1190 		return true;
1191 	return false;
1192 }
1193 
1194 static void smc_llc_process_cli_add_link(struct smc_link_group *lgr)
1195 {
1196 	struct smc_llc_qentry *qentry;
1197 
1198 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1199 
1200 	mutex_lock(&lgr->llc_conf_mutex);
1201 	if (smc_llc_is_local_add_link(&qentry->msg))
1202 		smc_llc_cli_add_link_invite(qentry->link, qentry);
1203 	else
1204 		smc_llc_cli_add_link(qentry->link, qentry);
1205 	mutex_unlock(&lgr->llc_conf_mutex);
1206 }
1207 
1208 static int smc_llc_active_link_count(struct smc_link_group *lgr)
1209 {
1210 	int i, link_count = 0;
1211 
1212 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1213 		if (!smc_link_active(&lgr->lnk[i]))
1214 			continue;
1215 		link_count++;
1216 	}
1217 	return link_count;
1218 }
1219 
1220 /* find the asymmetric link when 3 links are established  */
1221 static struct smc_link *smc_llc_find_asym_link(struct smc_link_group *lgr)
1222 {
1223 	int asym_idx = -ENOENT;
1224 	int i, j, k;
1225 	bool found;
1226 
1227 	/* determine asymmetric link */
1228 	found = false;
1229 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1230 		for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
1231 			if (!smc_link_usable(&lgr->lnk[i]) ||
1232 			    !smc_link_usable(&lgr->lnk[j]))
1233 				continue;
1234 			if (!memcmp(lgr->lnk[i].gid, lgr->lnk[j].gid,
1235 				    SMC_GID_SIZE)) {
1236 				found = true;	/* asym_lnk is i or j */
1237 				break;
1238 			}
1239 		}
1240 		if (found)
1241 			break;
1242 	}
1243 	if (!found)
1244 		goto out; /* no asymmetric link */
1245 	for (k = 0; k < SMC_LINKS_PER_LGR_MAX; k++) {
1246 		if (!smc_link_usable(&lgr->lnk[k]))
1247 			continue;
1248 		if (k != i &&
1249 		    !memcmp(lgr->lnk[i].peer_gid, lgr->lnk[k].peer_gid,
1250 			    SMC_GID_SIZE)) {
1251 			asym_idx = i;
1252 			break;
1253 		}
1254 		if (k != j &&
1255 		    !memcmp(lgr->lnk[j].peer_gid, lgr->lnk[k].peer_gid,
1256 			    SMC_GID_SIZE)) {
1257 			asym_idx = j;
1258 			break;
1259 		}
1260 	}
1261 out:
1262 	return (asym_idx < 0) ? NULL : &lgr->lnk[asym_idx];
1263 }
1264 
1265 static void smc_llc_delete_asym_link(struct smc_link_group *lgr)
1266 {
1267 	struct smc_link *lnk_new = NULL, *lnk_asym;
1268 	struct smc_llc_qentry *qentry;
1269 	int rc;
1270 
1271 	lnk_asym = smc_llc_find_asym_link(lgr);
1272 	if (!lnk_asym)
1273 		return; /* no asymmetric link */
1274 	if (!smc_link_downing(&lnk_asym->state))
1275 		return;
1276 	lnk_new = smc_switch_conns(lgr, lnk_asym, false);
1277 	smc_wr_tx_wait_no_pending_sends(lnk_asym);
1278 	if (!lnk_new)
1279 		goto out_free;
1280 	/* change flow type from ADD_LINK into DEL_LINK */
1281 	lgr->llc_flow_lcl.type = SMC_LLC_FLOW_DEL_LINK;
1282 	rc = smc_llc_send_delete_link(lnk_new, lnk_asym->link_id, SMC_LLC_REQ,
1283 				      true, SMC_LLC_DEL_NO_ASYM_NEEDED);
1284 	if (rc) {
1285 		smcr_link_down_cond(lnk_new);
1286 		goto out_free;
1287 	}
1288 	qentry = smc_llc_wait(lgr, lnk_new, SMC_LLC_WAIT_TIME,
1289 			      SMC_LLC_DELETE_LINK);
1290 	if (!qentry) {
1291 		smcr_link_down_cond(lnk_new);
1292 		goto out_free;
1293 	}
1294 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1295 out_free:
1296 	smcr_link_clear(lnk_asym, true);
1297 }
1298 
1299 static int smc_llc_srv_rkey_exchange(struct smc_link *link,
1300 				     struct smc_link *link_new)
1301 {
1302 	struct smc_llc_msg_add_link_cont *addc_llc;
1303 	struct smc_link_group *lgr = link->lgr;
1304 	u8 max, num_rkeys_send, num_rkeys_recv;
1305 	struct smc_llc_qentry *qentry = NULL;
1306 	struct smc_buf_desc *buf_pos;
1307 	int buf_lst;
1308 	int rc = 0;
1309 	int i;
1310 
1311 	mutex_lock(&lgr->rmbs_lock);
1312 	num_rkeys_send = lgr->conns_num;
1313 	buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
1314 	do {
1315 		smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
1316 				      &buf_lst, &buf_pos);
1317 		qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME,
1318 				      SMC_LLC_ADD_LINK_CONT);
1319 		if (!qentry) {
1320 			rc = -ETIMEDOUT;
1321 			goto out;
1322 		}
1323 		addc_llc = &qentry->msg.add_link_cont;
1324 		num_rkeys_recv = addc_llc->num_rkeys;
1325 		max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
1326 		for (i = 0; i < max; i++) {
1327 			smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1328 				       addc_llc->rt[i].rmb_key,
1329 				       addc_llc->rt[i].rmb_vaddr_new,
1330 				       addc_llc->rt[i].rmb_key_new);
1331 			num_rkeys_recv--;
1332 		}
1333 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1334 	} while (num_rkeys_send || num_rkeys_recv);
1335 out:
1336 	mutex_unlock(&lgr->rmbs_lock);
1337 	return rc;
1338 }
1339 
1340 static int smc_llc_srv_conf_link(struct smc_link *link,
1341 				 struct smc_link *link_new,
1342 				 enum smc_lgr_type lgr_new_t)
1343 {
1344 	struct smc_link_group *lgr = link->lgr;
1345 	struct smc_llc_qentry *qentry = NULL;
1346 	int rc;
1347 
1348 	/* send CONFIRM LINK request over the RoCE fabric */
1349 	rc = smc_llc_send_confirm_link(link_new, SMC_LLC_REQ);
1350 	if (rc)
1351 		return -ENOLINK;
1352 	/* receive CONFIRM LINK response over the RoCE fabric */
1353 	qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_FIRST_TIME, 0);
1354 	if (!qentry ||
1355 	    qentry->msg.raw.hdr.common.llc_type != SMC_LLC_CONFIRM_LINK) {
1356 		/* send DELETE LINK */
1357 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
1358 					 false, SMC_LLC_DEL_LOST_PATH);
1359 		if (qentry)
1360 			smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1361 		return -ENOLINK;
1362 	}
1363 	smc_llc_save_peer_uid(qentry);
1364 	smc_llc_link_active(link_new);
1365 	if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
1366 	    lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
1367 		smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
1368 	else
1369 		smcr_lgr_set_type(lgr, lgr_new_t);
1370 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1371 	return 0;
1372 }
1373 
1374 static void smc_llc_send_req_add_link_response(struct smc_llc_qentry *qentry)
1375 {
1376 	qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
1377 	smc_llc_init_msg_hdr(&qentry->msg.raw.hdr, qentry->link->lgr,
1378 			     sizeof(qentry->msg));
1379 	memset(&qentry->msg.raw.data, 0, sizeof(qentry->msg.raw.data));
1380 	smc_llc_send_message(qentry->link, &qentry->msg);
1381 }
1382 
1383 int smc_llc_srv_add_link(struct smc_link *link,
1384 			 struct smc_llc_qentry *req_qentry)
1385 {
1386 	enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1387 	struct smc_link_group *lgr = link->lgr;
1388 	struct smc_llc_msg_add_link *add_llc;
1389 	struct smc_llc_qentry *qentry = NULL;
1390 	bool send_req_add_link_resp = false;
1391 	struct smc_link *link_new = NULL;
1392 	struct smc_init_info *ini = NULL;
1393 	int lnk_idx, rc = 0;
1394 
1395 	if (req_qentry &&
1396 	    req_qentry->msg.raw.hdr.common.llc_type == SMC_LLC_REQ_ADD_LINK)
1397 		send_req_add_link_resp = true;
1398 
1399 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1400 	if (!ini) {
1401 		rc = -ENOMEM;
1402 		goto out;
1403 	}
1404 
1405 	/* ignore client add link recommendation, start new flow */
1406 	ini->vlan_id = lgr->vlan_id;
1407 	if (lgr->smc_version == SMC_V2) {
1408 		ini->check_smcrv2 = true;
1409 		ini->smcrv2.saddr = lgr->saddr;
1410 		if (send_req_add_link_resp) {
1411 			struct smc_llc_msg_req_add_link_v2 *req_add =
1412 				&req_qentry->msg.req_add_link;
1413 
1414 			ini->smcrv2.daddr = smc_ib_gid_to_ipv4(req_add->gid[0]);
1415 		}
1416 	}
1417 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1418 	if (lgr->smc_version == SMC_V2 && !ini->smcrv2.ib_dev_v2) {
1419 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1420 		ini->smcrv2.ib_dev_v2 = link->smcibdev;
1421 		ini->smcrv2.ib_port_v2 = link->ibport;
1422 	} else if (lgr->smc_version < SMC_V2 && !ini->ib_dev) {
1423 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1424 		ini->ib_dev = link->smcibdev;
1425 		ini->ib_port = link->ibport;
1426 	}
1427 	lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1428 	if (lnk_idx < 0) {
1429 		rc = 0;
1430 		goto out;
1431 	}
1432 
1433 	rc = smcr_link_init(lgr, &lgr->lnk[lnk_idx], lnk_idx, ini);
1434 	if (rc)
1435 		goto out;
1436 	link_new = &lgr->lnk[lnk_idx];
1437 
1438 	rc = smcr_buf_map_lgr(link_new);
1439 	if (rc)
1440 		goto out_err;
1441 
1442 	rc = smc_llc_send_add_link(link,
1443 				   link_new->smcibdev->mac[link_new->ibport-1],
1444 				   link_new->gid, link_new, SMC_LLC_REQ);
1445 	if (rc)
1446 		goto out_err;
1447 	send_req_add_link_resp = false;
1448 	/* receive ADD LINK response over the RoCE fabric */
1449 	qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME, SMC_LLC_ADD_LINK);
1450 	if (!qentry) {
1451 		rc = -ETIMEDOUT;
1452 		goto out_err;
1453 	}
1454 	add_llc = &qentry->msg.add_link;
1455 	if (add_llc->hd.flags & SMC_LLC_FLAG_ADD_LNK_REJ) {
1456 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1457 		rc = -ENOLINK;
1458 		goto out_err;
1459 	}
1460 	if (lgr->type == SMC_LGR_SINGLE &&
1461 	    (!memcmp(add_llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1462 	     (lgr->smc_version == SMC_V2 ||
1463 	      !memcmp(add_llc->sender_mac, link->peer_mac, ETH_ALEN)))) {
1464 		lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1465 	}
1466 	smc_llc_save_add_link_info(link_new, add_llc);
1467 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1468 
1469 	rc = smc_ib_ready_link(link_new);
1470 	if (rc)
1471 		goto out_err;
1472 	rc = smcr_buf_reg_lgr(link_new);
1473 	if (rc)
1474 		goto out_err;
1475 	if (lgr->smc_version == SMC_V2) {
1476 		smc_llc_save_add_link_rkeys(link, link_new);
1477 	} else {
1478 		rc = smc_llc_srv_rkey_exchange(link, link_new);
1479 		if (rc)
1480 			goto out_err;
1481 	}
1482 	rc = smc_llc_srv_conf_link(link, link_new, lgr_new_t);
1483 	if (rc)
1484 		goto out_err;
1485 	kfree(ini);
1486 	return 0;
1487 out_err:
1488 	if (link_new) {
1489 		link_new->state = SMC_LNK_INACTIVE;
1490 		smcr_link_clear(link_new, false);
1491 	}
1492 out:
1493 	kfree(ini);
1494 	if (send_req_add_link_resp)
1495 		smc_llc_send_req_add_link_response(req_qentry);
1496 	return rc;
1497 }
1498 
1499 static void smc_llc_process_srv_add_link(struct smc_link_group *lgr)
1500 {
1501 	struct smc_link *link = lgr->llc_flow_lcl.qentry->link;
1502 	struct smc_llc_qentry *qentry;
1503 	int rc;
1504 
1505 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1506 
1507 	mutex_lock(&lgr->llc_conf_mutex);
1508 	rc = smc_llc_srv_add_link(link, qentry);
1509 	if (!rc && lgr->type == SMC_LGR_SYMMETRIC) {
1510 		/* delete any asymmetric link */
1511 		smc_llc_delete_asym_link(lgr);
1512 	}
1513 	mutex_unlock(&lgr->llc_conf_mutex);
1514 	kfree(qentry);
1515 }
1516 
1517 /* enqueue a local add_link req to trigger a new add_link flow */
1518 void smc_llc_add_link_local(struct smc_link *link)
1519 {
1520 	struct smc_llc_msg_add_link add_llc = {};
1521 
1522 	add_llc.hd.common.llc_type = SMC_LLC_ADD_LINK;
1523 	smc_llc_init_msg_hdr(&add_llc.hd, link->lgr, sizeof(add_llc));
1524 	/* no dev and port needed */
1525 	smc_llc_enqueue(link, (union smc_llc_msg *)&add_llc);
1526 }
1527 
1528 /* worker to process an add link message */
1529 static void smc_llc_add_link_work(struct work_struct *work)
1530 {
1531 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1532 						  llc_add_link_work);
1533 
1534 	if (list_empty(&lgr->list)) {
1535 		/* link group is terminating */
1536 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1537 		goto out;
1538 	}
1539 
1540 	if (lgr->role == SMC_CLNT)
1541 		smc_llc_process_cli_add_link(lgr);
1542 	else
1543 		smc_llc_process_srv_add_link(lgr);
1544 out:
1545 	if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_REQ_ADD_LINK)
1546 		smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1547 }
1548 
1549 /* enqueue a local del_link msg to trigger a new del_link flow,
1550  * called only for role SMC_SERV
1551  */
1552 void smc_llc_srv_delete_link_local(struct smc_link *link, u8 del_link_id)
1553 {
1554 	struct smc_llc_msg_del_link del_llc = {};
1555 
1556 	del_llc.hd.common.llc_type = SMC_LLC_DELETE_LINK;
1557 	smc_llc_init_msg_hdr(&del_llc.hd, link->lgr, sizeof(del_llc));
1558 	del_llc.link_num = del_link_id;
1559 	del_llc.reason = htonl(SMC_LLC_DEL_LOST_PATH);
1560 	del_llc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1561 	smc_llc_enqueue(link, (union smc_llc_msg *)&del_llc);
1562 }
1563 
1564 static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
1565 {
1566 	struct smc_link *lnk_del = NULL, *lnk_asym, *lnk;
1567 	struct smc_llc_msg_del_link *del_llc;
1568 	struct smc_llc_qentry *qentry;
1569 	int active_links;
1570 	int lnk_idx;
1571 
1572 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1573 	lnk = qentry->link;
1574 	del_llc = &qentry->msg.delete_link;
1575 
1576 	if (del_llc->hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1577 		smc_lgr_terminate_sched(lgr);
1578 		goto out;
1579 	}
1580 	mutex_lock(&lgr->llc_conf_mutex);
1581 	/* delete single link */
1582 	for (lnk_idx = 0; lnk_idx < SMC_LINKS_PER_LGR_MAX; lnk_idx++) {
1583 		if (lgr->lnk[lnk_idx].link_id != del_llc->link_num)
1584 			continue;
1585 		lnk_del = &lgr->lnk[lnk_idx];
1586 		break;
1587 	}
1588 	del_llc->hd.flags |= SMC_LLC_FLAG_RESP;
1589 	if (!lnk_del) {
1590 		/* link was not found */
1591 		del_llc->reason = htonl(SMC_LLC_DEL_NOLNK);
1592 		smc_llc_send_message(lnk, &qentry->msg);
1593 		goto out_unlock;
1594 	}
1595 	lnk_asym = smc_llc_find_asym_link(lgr);
1596 
1597 	del_llc->reason = 0;
1598 	smc_llc_send_message(lnk, &qentry->msg); /* response */
1599 
1600 	if (smc_link_downing(&lnk_del->state))
1601 		smc_switch_conns(lgr, lnk_del, false);
1602 	smcr_link_clear(lnk_del, true);
1603 
1604 	active_links = smc_llc_active_link_count(lgr);
1605 	if (lnk_del == lnk_asym) {
1606 		/* expected deletion of asym link, don't change lgr state */
1607 	} else if (active_links == 1) {
1608 		smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1609 	} else if (!active_links) {
1610 		smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1611 		smc_lgr_terminate_sched(lgr);
1612 	}
1613 out_unlock:
1614 	mutex_unlock(&lgr->llc_conf_mutex);
1615 out:
1616 	kfree(qentry);
1617 }
1618 
1619 /* try to send a DELETE LINK ALL request on any active link,
1620  * waiting for send completion
1621  */
1622 void smc_llc_send_link_delete_all(struct smc_link_group *lgr, bool ord, u32 rsn)
1623 {
1624 	struct smc_llc_msg_del_link delllc = {};
1625 	int i;
1626 
1627 	delllc.hd.common.llc_type = SMC_LLC_DELETE_LINK;
1628 	smc_llc_init_msg_hdr(&delllc.hd, lgr, sizeof(delllc));
1629 	if (ord)
1630 		delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1631 	delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
1632 	delllc.reason = htonl(rsn);
1633 
1634 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1635 		if (!smc_link_sendable(&lgr->lnk[i]))
1636 			continue;
1637 		if (!smc_llc_send_message_wait(&lgr->lnk[i], &delllc))
1638 			break;
1639 	}
1640 }
1641 
1642 static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr)
1643 {
1644 	struct smc_llc_msg_del_link *del_llc;
1645 	struct smc_link *lnk, *lnk_del;
1646 	struct smc_llc_qentry *qentry;
1647 	int active_links;
1648 	int i;
1649 
1650 	mutex_lock(&lgr->llc_conf_mutex);
1651 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1652 	lnk = qentry->link;
1653 	del_llc = &qentry->msg.delete_link;
1654 
1655 	if (qentry->msg.delete_link.hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1656 		/* delete entire lgr */
1657 		smc_llc_send_link_delete_all(lgr, true, ntohl(
1658 					      qentry->msg.delete_link.reason));
1659 		smc_lgr_terminate_sched(lgr);
1660 		goto out;
1661 	}
1662 	/* delete single link */
1663 	lnk_del = NULL;
1664 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1665 		if (lgr->lnk[i].link_id == del_llc->link_num) {
1666 			lnk_del = &lgr->lnk[i];
1667 			break;
1668 		}
1669 	}
1670 	if (!lnk_del)
1671 		goto out; /* asymmetric link already deleted */
1672 
1673 	if (smc_link_downing(&lnk_del->state)) {
1674 		if (smc_switch_conns(lgr, lnk_del, false))
1675 			smc_wr_tx_wait_no_pending_sends(lnk_del);
1676 	}
1677 	if (!list_empty(&lgr->list)) {
1678 		/* qentry is either a request from peer (send it back to
1679 		 * initiate the DELETE_LINK processing), or a locally
1680 		 * enqueued DELETE_LINK request (forward it)
1681 		 */
1682 		if (!smc_llc_send_message(lnk, &qentry->msg)) {
1683 			struct smc_llc_qentry *qentry2;
1684 
1685 			qentry2 = smc_llc_wait(lgr, lnk, SMC_LLC_WAIT_TIME,
1686 					       SMC_LLC_DELETE_LINK);
1687 			if (qentry2)
1688 				smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1689 		}
1690 	}
1691 	smcr_link_clear(lnk_del, true);
1692 
1693 	active_links = smc_llc_active_link_count(lgr);
1694 	if (active_links == 1) {
1695 		smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1696 	} else if (!active_links) {
1697 		smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1698 		smc_lgr_terminate_sched(lgr);
1699 	}
1700 
1701 	if (lgr->type == SMC_LGR_SINGLE && !list_empty(&lgr->list)) {
1702 		/* trigger setup of asymm alt link */
1703 		smc_llc_add_link_local(lnk);
1704 	}
1705 out:
1706 	mutex_unlock(&lgr->llc_conf_mutex);
1707 	kfree(qentry);
1708 }
1709 
1710 static void smc_llc_delete_link_work(struct work_struct *work)
1711 {
1712 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1713 						  llc_del_link_work);
1714 
1715 	if (list_empty(&lgr->list)) {
1716 		/* link group is terminating */
1717 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1718 		goto out;
1719 	}
1720 
1721 	if (lgr->role == SMC_CLNT)
1722 		smc_llc_process_cli_delete_link(lgr);
1723 	else
1724 		smc_llc_process_srv_delete_link(lgr);
1725 out:
1726 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1727 }
1728 
1729 /* process a confirm_rkey request from peer, remote flow */
1730 static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr)
1731 {
1732 	struct smc_llc_msg_confirm_rkey *llc;
1733 	struct smc_llc_qentry *qentry;
1734 	struct smc_link *link;
1735 	int num_entries;
1736 	int rk_idx;
1737 	int i;
1738 
1739 	qentry = lgr->llc_flow_rmt.qentry;
1740 	llc = &qentry->msg.confirm_rkey;
1741 	link = qentry->link;
1742 
1743 	num_entries = llc->rtoken[0].num_rkeys;
1744 	if (num_entries > SMC_LLC_RKEYS_PER_MSG)
1745 		goto out_err;
1746 	/* first rkey entry is for receiving link */
1747 	rk_idx = smc_rtoken_add(link,
1748 				llc->rtoken[0].rmb_vaddr,
1749 				llc->rtoken[0].rmb_key);
1750 	if (rk_idx < 0)
1751 		goto out_err;
1752 
1753 	for (i = 1; i <= min_t(u8, num_entries, SMC_LLC_RKEYS_PER_MSG - 1); i++)
1754 		smc_rtoken_set2(lgr, rk_idx, llc->rtoken[i].link_id,
1755 				llc->rtoken[i].rmb_vaddr,
1756 				llc->rtoken[i].rmb_key);
1757 	/* max links is 3 so there is no need to support conf_rkey_cont msgs */
1758 	goto out;
1759 out_err:
1760 	llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1761 	llc->hd.flags |= SMC_LLC_FLAG_RKEY_RETRY;
1762 out:
1763 	llc->hd.flags |= SMC_LLC_FLAG_RESP;
1764 	smc_llc_init_msg_hdr(&llc->hd, link->lgr, sizeof(*llc));
1765 	smc_llc_send_message(link, &qentry->msg);
1766 	smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1767 }
1768 
1769 /* process a delete_rkey request from peer, remote flow */
1770 static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr)
1771 {
1772 	struct smc_llc_msg_delete_rkey *llc;
1773 	struct smc_llc_qentry *qentry;
1774 	struct smc_link *link;
1775 	u8 err_mask = 0;
1776 	int i, max;
1777 
1778 	qentry = lgr->llc_flow_rmt.qentry;
1779 	llc = &qentry->msg.delete_rkey;
1780 	link = qentry->link;
1781 
1782 	if (lgr->smc_version == SMC_V2) {
1783 		struct smc_llc_msg_delete_rkey_v2 *llcv2;
1784 
1785 		memcpy(lgr->wr_rx_buf_v2, llc, sizeof(*llc));
1786 		llcv2 = (struct smc_llc_msg_delete_rkey_v2 *)lgr->wr_rx_buf_v2;
1787 		llcv2->num_inval_rkeys = 0;
1788 
1789 		max = min_t(u8, llcv2->num_rkeys, SMC_LLC_RKEYS_PER_MSG_V2);
1790 		for (i = 0; i < max; i++) {
1791 			if (smc_rtoken_delete(link, llcv2->rkey[i]))
1792 				llcv2->num_inval_rkeys++;
1793 		}
1794 		memset(&llc->rkey[0], 0, sizeof(llc->rkey));
1795 		memset(&llc->reserved2, 0, sizeof(llc->reserved2));
1796 		smc_llc_init_msg_hdr(&llc->hd, link->lgr, sizeof(*llc));
1797 		if (llcv2->num_inval_rkeys) {
1798 			llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1799 			llc->err_mask = llcv2->num_inval_rkeys;
1800 		}
1801 		goto finish;
1802 	}
1803 
1804 	max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
1805 	for (i = 0; i < max; i++) {
1806 		if (smc_rtoken_delete(link, llc->rkey[i]))
1807 			err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
1808 	}
1809 	if (err_mask) {
1810 		llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1811 		llc->err_mask = err_mask;
1812 	}
1813 finish:
1814 	llc->hd.flags |= SMC_LLC_FLAG_RESP;
1815 	smc_llc_send_message(link, &qentry->msg);
1816 	smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1817 }
1818 
1819 static void smc_llc_protocol_violation(struct smc_link_group *lgr, u8 type)
1820 {
1821 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu LLC protocol violation: "
1822 			    "llc_type %d\n", SMC_LGR_ID_SIZE, &lgr->id,
1823 			    lgr->net->net_cookie, type);
1824 	smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_PROT_VIOL);
1825 	smc_lgr_terminate_sched(lgr);
1826 }
1827 
1828 /* flush the llc event queue */
1829 static void smc_llc_event_flush(struct smc_link_group *lgr)
1830 {
1831 	struct smc_llc_qentry *qentry, *q;
1832 
1833 	spin_lock_bh(&lgr->llc_event_q_lock);
1834 	list_for_each_entry_safe(qentry, q, &lgr->llc_event_q, list) {
1835 		list_del_init(&qentry->list);
1836 		kfree(qentry);
1837 	}
1838 	spin_unlock_bh(&lgr->llc_event_q_lock);
1839 }
1840 
1841 static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
1842 {
1843 	union smc_llc_msg *llc = &qentry->msg;
1844 	struct smc_link *link = qentry->link;
1845 	struct smc_link_group *lgr = link->lgr;
1846 
1847 	if (!smc_link_usable(link))
1848 		goto out;
1849 
1850 	switch (llc->raw.hdr.common.llc_type) {
1851 	case SMC_LLC_TEST_LINK:
1852 		llc->test_link.hd.flags |= SMC_LLC_FLAG_RESP;
1853 		smc_llc_send_message(link, llc);
1854 		break;
1855 	case SMC_LLC_ADD_LINK:
1856 		if (list_empty(&lgr->list))
1857 			goto out;	/* lgr is terminating */
1858 		if (lgr->role == SMC_CLNT) {
1859 			if (smc_llc_is_local_add_link(llc)) {
1860 				if (lgr->llc_flow_lcl.type ==
1861 				    SMC_LLC_FLOW_ADD_LINK)
1862 					break;	/* add_link in progress */
1863 				if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1864 						       qentry)) {
1865 					schedule_work(&lgr->llc_add_link_work);
1866 				}
1867 				return;
1868 			}
1869 			if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1870 			    !lgr->llc_flow_lcl.qentry) {
1871 				/* a flow is waiting for this message */
1872 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1873 							qentry);
1874 				wake_up(&lgr->llc_msg_waiter);
1875 				return;
1876 			}
1877 			if (lgr->llc_flow_lcl.type ==
1878 					SMC_LLC_FLOW_REQ_ADD_LINK) {
1879 				/* server started add_link processing */
1880 				lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK;
1881 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1882 							qentry);
1883 				schedule_work(&lgr->llc_add_link_work);
1884 				return;
1885 			}
1886 			if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1887 				schedule_work(&lgr->llc_add_link_work);
1888 			}
1889 		} else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1890 			/* as smc server, handle client suggestion */
1891 			schedule_work(&lgr->llc_add_link_work);
1892 		}
1893 		return;
1894 	case SMC_LLC_CONFIRM_LINK:
1895 	case SMC_LLC_ADD_LINK_CONT:
1896 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1897 			/* a flow is waiting for this message */
1898 			smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1899 			wake_up(&lgr->llc_msg_waiter);
1900 			return;
1901 		}
1902 		break;
1903 	case SMC_LLC_DELETE_LINK:
1904 		if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1905 		    !lgr->llc_flow_lcl.qentry) {
1906 			/* DEL LINK REQ during ADD LINK SEQ */
1907 			smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1908 			wake_up(&lgr->llc_msg_waiter);
1909 		} else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1910 			schedule_work(&lgr->llc_del_link_work);
1911 		}
1912 		return;
1913 	case SMC_LLC_CONFIRM_RKEY:
1914 		/* new request from remote, assign to remote flow */
1915 		if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1916 			/* process here, does not wait for more llc msgs */
1917 			smc_llc_rmt_conf_rkey(lgr);
1918 			smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1919 		}
1920 		return;
1921 	case SMC_LLC_CONFIRM_RKEY_CONT:
1922 		/* not used because max links is 3, and 3 rkeys fit into
1923 		 * one CONFIRM_RKEY message
1924 		 */
1925 		break;
1926 	case SMC_LLC_DELETE_RKEY:
1927 		/* new request from remote, assign to remote flow */
1928 		if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1929 			/* process here, does not wait for more llc msgs */
1930 			smc_llc_rmt_delete_rkey(lgr);
1931 			smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1932 		}
1933 		return;
1934 	case SMC_LLC_REQ_ADD_LINK:
1935 		/* handle response here, smc_llc_flow_stop() cannot be called
1936 		 * in tasklet context
1937 		 */
1938 		if (lgr->role == SMC_CLNT &&
1939 		    lgr->llc_flow_lcl.type == SMC_LLC_FLOW_REQ_ADD_LINK &&
1940 		    (llc->raw.hdr.flags & SMC_LLC_FLAG_RESP)) {
1941 			smc_llc_flow_stop(link->lgr, &lgr->llc_flow_lcl);
1942 		} else if (lgr->role == SMC_SERV) {
1943 			if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1944 				/* as smc server, handle client suggestion */
1945 				lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK;
1946 				schedule_work(&lgr->llc_add_link_work);
1947 			}
1948 			return;
1949 		}
1950 		break;
1951 	default:
1952 		smc_llc_protocol_violation(lgr, llc->raw.hdr.common.type);
1953 		break;
1954 	}
1955 out:
1956 	kfree(qentry);
1957 }
1958 
1959 /* worker to process llc messages on the event queue */
1960 static void smc_llc_event_work(struct work_struct *work)
1961 {
1962 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1963 						  llc_event_work);
1964 	struct smc_llc_qentry *qentry;
1965 
1966 	if (!lgr->llc_flow_lcl.type && lgr->delayed_event) {
1967 		qentry = lgr->delayed_event;
1968 		lgr->delayed_event = NULL;
1969 		if (smc_link_usable(qentry->link))
1970 			smc_llc_event_handler(qentry);
1971 		else
1972 			kfree(qentry);
1973 	}
1974 
1975 again:
1976 	spin_lock_bh(&lgr->llc_event_q_lock);
1977 	if (!list_empty(&lgr->llc_event_q)) {
1978 		qentry = list_first_entry(&lgr->llc_event_q,
1979 					  struct smc_llc_qentry, list);
1980 		list_del_init(&qentry->list);
1981 		spin_unlock_bh(&lgr->llc_event_q_lock);
1982 		smc_llc_event_handler(qentry);
1983 		goto again;
1984 	}
1985 	spin_unlock_bh(&lgr->llc_event_q_lock);
1986 }
1987 
1988 /* process llc responses in tasklet context */
1989 static void smc_llc_rx_response(struct smc_link *link,
1990 				struct smc_llc_qentry *qentry)
1991 {
1992 	enum smc_llc_flowtype flowtype = link->lgr->llc_flow_lcl.type;
1993 	struct smc_llc_flow *flow = &link->lgr->llc_flow_lcl;
1994 	u8 llc_type = qentry->msg.raw.hdr.common.llc_type;
1995 
1996 	switch (llc_type) {
1997 	case SMC_LLC_TEST_LINK:
1998 		if (smc_link_active(link))
1999 			complete(&link->llc_testlink_resp);
2000 		break;
2001 	case SMC_LLC_ADD_LINK:
2002 	case SMC_LLC_ADD_LINK_CONT:
2003 	case SMC_LLC_CONFIRM_LINK:
2004 		if (flowtype != SMC_LLC_FLOW_ADD_LINK || flow->qentry)
2005 			break;	/* drop out-of-flow response */
2006 		goto assign;
2007 	case SMC_LLC_DELETE_LINK:
2008 		if (flowtype != SMC_LLC_FLOW_DEL_LINK || flow->qentry)
2009 			break;	/* drop out-of-flow response */
2010 		goto assign;
2011 	case SMC_LLC_CONFIRM_RKEY:
2012 	case SMC_LLC_DELETE_RKEY:
2013 		if (flowtype != SMC_LLC_FLOW_RKEY || flow->qentry)
2014 			break;	/* drop out-of-flow response */
2015 		goto assign;
2016 	case SMC_LLC_CONFIRM_RKEY_CONT:
2017 		/* not used because max links is 3 */
2018 		break;
2019 	default:
2020 		smc_llc_protocol_violation(link->lgr,
2021 					   qentry->msg.raw.hdr.common.type);
2022 		break;
2023 	}
2024 	kfree(qentry);
2025 	return;
2026 assign:
2027 	/* assign responses to the local flow, we requested them */
2028 	smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
2029 	wake_up(&link->lgr->llc_msg_waiter);
2030 }
2031 
2032 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc)
2033 {
2034 	struct smc_link_group *lgr = link->lgr;
2035 	struct smc_llc_qentry *qentry;
2036 	unsigned long flags;
2037 
2038 	qentry = kmalloc(sizeof(*qentry), GFP_ATOMIC);
2039 	if (!qentry)
2040 		return;
2041 	qentry->link = link;
2042 	INIT_LIST_HEAD(&qentry->list);
2043 	memcpy(&qentry->msg, llc, sizeof(union smc_llc_msg));
2044 
2045 	/* process responses immediately */
2046 	if ((llc->raw.hdr.flags & SMC_LLC_FLAG_RESP) &&
2047 	    llc->raw.hdr.common.llc_type != SMC_LLC_REQ_ADD_LINK) {
2048 		smc_llc_rx_response(link, qentry);
2049 		return;
2050 	}
2051 
2052 	/* add requests to event queue */
2053 	spin_lock_irqsave(&lgr->llc_event_q_lock, flags);
2054 	list_add_tail(&qentry->list, &lgr->llc_event_q);
2055 	spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags);
2056 	queue_work(system_highpri_wq, &lgr->llc_event_work);
2057 }
2058 
2059 /* copy received msg and add it to the event queue */
2060 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
2061 {
2062 	struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
2063 	union smc_llc_msg *llc = buf;
2064 
2065 	if (wc->byte_len < sizeof(*llc))
2066 		return; /* short message */
2067 	if (!llc->raw.hdr.common.llc_version) {
2068 		if (llc->raw.hdr.length != sizeof(*llc))
2069 			return; /* invalid message */
2070 	} else {
2071 		if (llc->raw.hdr.length_v2 < sizeof(*llc))
2072 			return; /* invalid message */
2073 	}
2074 
2075 	smc_llc_enqueue(link, llc);
2076 }
2077 
2078 /***************************** worker, utils *********************************/
2079 
2080 static void smc_llc_testlink_work(struct work_struct *work)
2081 {
2082 	struct smc_link *link = container_of(to_delayed_work(work),
2083 					     struct smc_link, llc_testlink_wrk);
2084 	unsigned long next_interval;
2085 	unsigned long expire_time;
2086 	u8 user_data[16] = { 0 };
2087 	int rc;
2088 
2089 	if (!smc_link_active(link))
2090 		return;		/* don't reschedule worker */
2091 	expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
2092 	if (time_is_after_jiffies(expire_time)) {
2093 		next_interval = expire_time - jiffies;
2094 		goto out;
2095 	}
2096 	reinit_completion(&link->llc_testlink_resp);
2097 	smc_llc_send_test_link(link, user_data);
2098 	/* receive TEST LINK response over RoCE fabric */
2099 	rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
2100 						       SMC_LLC_WAIT_TIME);
2101 	if (!smc_link_active(link))
2102 		return;		/* link state changed */
2103 	if (rc <= 0) {
2104 		smcr_link_down_cond_sched(link);
2105 		return;
2106 	}
2107 	next_interval = link->llc_testlink_time;
2108 out:
2109 	schedule_delayed_work(&link->llc_testlink_wrk, next_interval);
2110 }
2111 
2112 void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
2113 {
2114 	struct net *net = sock_net(smc->clcsock->sk);
2115 
2116 	INIT_WORK(&lgr->llc_event_work, smc_llc_event_work);
2117 	INIT_WORK(&lgr->llc_add_link_work, smc_llc_add_link_work);
2118 	INIT_WORK(&lgr->llc_del_link_work, smc_llc_delete_link_work);
2119 	INIT_LIST_HEAD(&lgr->llc_event_q);
2120 	spin_lock_init(&lgr->llc_event_q_lock);
2121 	spin_lock_init(&lgr->llc_flow_lock);
2122 	init_waitqueue_head(&lgr->llc_flow_waiter);
2123 	init_waitqueue_head(&lgr->llc_msg_waiter);
2124 	mutex_init(&lgr->llc_conf_mutex);
2125 	lgr->llc_testlink_time = READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time);
2126 }
2127 
2128 /* called after lgr was removed from lgr_list */
2129 void smc_llc_lgr_clear(struct smc_link_group *lgr)
2130 {
2131 	smc_llc_event_flush(lgr);
2132 	wake_up_all(&lgr->llc_flow_waiter);
2133 	wake_up_all(&lgr->llc_msg_waiter);
2134 	cancel_work_sync(&lgr->llc_event_work);
2135 	cancel_work_sync(&lgr->llc_add_link_work);
2136 	cancel_work_sync(&lgr->llc_del_link_work);
2137 	if (lgr->delayed_event) {
2138 		kfree(lgr->delayed_event);
2139 		lgr->delayed_event = NULL;
2140 	}
2141 }
2142 
2143 int smc_llc_link_init(struct smc_link *link)
2144 {
2145 	init_completion(&link->llc_testlink_resp);
2146 	INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
2147 	return 0;
2148 }
2149 
2150 void smc_llc_link_active(struct smc_link *link)
2151 {
2152 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu link added: id %*phN, "
2153 			    "peerid %*phN, ibdev %s, ibport %d\n",
2154 			    SMC_LGR_ID_SIZE, &link->lgr->id,
2155 			    link->lgr->net->net_cookie,
2156 			    SMC_LGR_ID_SIZE, &link->link_uid,
2157 			    SMC_LGR_ID_SIZE, &link->peer_link_uid,
2158 			    link->smcibdev->ibdev->name, link->ibport);
2159 	link->state = SMC_LNK_ACTIVE;
2160 	if (link->lgr->llc_testlink_time) {
2161 		link->llc_testlink_time = link->lgr->llc_testlink_time;
2162 		schedule_delayed_work(&link->llc_testlink_wrk,
2163 				      link->llc_testlink_time);
2164 	}
2165 }
2166 
2167 /* called in worker context */
2168 void smc_llc_link_clear(struct smc_link *link, bool log)
2169 {
2170 	if (log)
2171 		pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu link removed: id %*phN"
2172 				    ", peerid %*phN, ibdev %s, ibport %d\n",
2173 				    SMC_LGR_ID_SIZE, &link->lgr->id,
2174 				    link->lgr->net->net_cookie,
2175 				    SMC_LGR_ID_SIZE, &link->link_uid,
2176 				    SMC_LGR_ID_SIZE, &link->peer_link_uid,
2177 				    link->smcibdev->ibdev->name, link->ibport);
2178 	complete(&link->llc_testlink_resp);
2179 	cancel_delayed_work_sync(&link->llc_testlink_wrk);
2180 }
2181 
2182 /* register a new rtoken at the remote peer (for all links) */
2183 int smc_llc_do_confirm_rkey(struct smc_link *send_link,
2184 			    struct smc_buf_desc *rmb_desc)
2185 {
2186 	struct smc_link_group *lgr = send_link->lgr;
2187 	struct smc_llc_qentry *qentry = NULL;
2188 	int rc = 0;
2189 
2190 	rc = smc_llc_send_confirm_rkey(send_link, rmb_desc);
2191 	if (rc)
2192 		goto out;
2193 	/* receive CONFIRM RKEY response from server over RoCE fabric */
2194 	qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
2195 			      SMC_LLC_CONFIRM_RKEY);
2196 	if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
2197 		rc = -EFAULT;
2198 out:
2199 	if (qentry)
2200 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
2201 	return rc;
2202 }
2203 
2204 /* unregister an rtoken at the remote peer */
2205 int smc_llc_do_delete_rkey(struct smc_link_group *lgr,
2206 			   struct smc_buf_desc *rmb_desc)
2207 {
2208 	struct smc_llc_qentry *qentry = NULL;
2209 	struct smc_link *send_link;
2210 	int rc = 0;
2211 
2212 	send_link = smc_llc_usable_link(lgr);
2213 	if (!send_link)
2214 		return -ENOLINK;
2215 
2216 	/* protected by llc_flow control */
2217 	rc = smc_llc_send_delete_rkey(send_link, rmb_desc);
2218 	if (rc)
2219 		goto out;
2220 	/* receive DELETE RKEY response from server over RoCE fabric */
2221 	qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
2222 			      SMC_LLC_DELETE_RKEY);
2223 	if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
2224 		rc = -EFAULT;
2225 out:
2226 	if (qentry)
2227 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
2228 	return rc;
2229 }
2230 
2231 void smc_llc_link_set_uid(struct smc_link *link)
2232 {
2233 	__be32 link_uid;
2234 
2235 	link_uid = htonl(*((u32 *)link->lgr->id) + link->link_id);
2236 	memcpy(link->link_uid, &link_uid, SMC_LGR_ID_SIZE);
2237 }
2238 
2239 /* save peers link user id, used for debug purposes */
2240 void smc_llc_save_peer_uid(struct smc_llc_qentry *qentry)
2241 {
2242 	memcpy(qentry->link->peer_link_uid, qentry->msg.confirm_link.link_uid,
2243 	       SMC_LGR_ID_SIZE);
2244 }
2245 
2246 /* evaluate confirm link request or response */
2247 int smc_llc_eval_conf_link(struct smc_llc_qentry *qentry,
2248 			   enum smc_llc_reqresp type)
2249 {
2250 	if (type == SMC_LLC_REQ) {	/* SMC server assigns link_id */
2251 		qentry->link->link_id = qentry->msg.confirm_link.link_num;
2252 		smc_llc_link_set_uid(qentry->link);
2253 	}
2254 	if (!(qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_NO_RMBE_EYEC))
2255 		return -ENOTSUPP;
2256 	return 0;
2257 }
2258 
2259 /***************************** init, exit, misc ******************************/
2260 
2261 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
2262 	{
2263 		.handler	= smc_llc_rx_handler,
2264 		.type		= SMC_LLC_CONFIRM_LINK
2265 	},
2266 	{
2267 		.handler	= smc_llc_rx_handler,
2268 		.type		= SMC_LLC_TEST_LINK
2269 	},
2270 	{
2271 		.handler	= smc_llc_rx_handler,
2272 		.type		= SMC_LLC_ADD_LINK
2273 	},
2274 	{
2275 		.handler	= smc_llc_rx_handler,
2276 		.type		= SMC_LLC_ADD_LINK_CONT
2277 	},
2278 	{
2279 		.handler	= smc_llc_rx_handler,
2280 		.type		= SMC_LLC_DELETE_LINK
2281 	},
2282 	{
2283 		.handler	= smc_llc_rx_handler,
2284 		.type		= SMC_LLC_CONFIRM_RKEY
2285 	},
2286 	{
2287 		.handler	= smc_llc_rx_handler,
2288 		.type		= SMC_LLC_CONFIRM_RKEY_CONT
2289 	},
2290 	{
2291 		.handler	= smc_llc_rx_handler,
2292 		.type		= SMC_LLC_DELETE_RKEY
2293 	},
2294 	/* V2 types */
2295 	{
2296 		.handler	= smc_llc_rx_handler,
2297 		.type		= SMC_LLC_CONFIRM_LINK_V2
2298 	},
2299 	{
2300 		.handler	= smc_llc_rx_handler,
2301 		.type		= SMC_LLC_TEST_LINK_V2
2302 	},
2303 	{
2304 		.handler	= smc_llc_rx_handler,
2305 		.type		= SMC_LLC_ADD_LINK_V2
2306 	},
2307 	{
2308 		.handler	= smc_llc_rx_handler,
2309 		.type		= SMC_LLC_DELETE_LINK_V2
2310 	},
2311 	{
2312 		.handler	= smc_llc_rx_handler,
2313 		.type		= SMC_LLC_REQ_ADD_LINK_V2
2314 	},
2315 	{
2316 		.handler	= smc_llc_rx_handler,
2317 		.type		= SMC_LLC_CONFIRM_RKEY_V2
2318 	},
2319 	{
2320 		.handler	= smc_llc_rx_handler,
2321 		.type		= SMC_LLC_DELETE_RKEY_V2
2322 	},
2323 	{
2324 		.handler	= NULL,
2325 	}
2326 };
2327 
2328 int __init smc_llc_init(void)
2329 {
2330 	struct smc_wr_rx_handler *handler;
2331 	int rc = 0;
2332 
2333 	for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
2334 		INIT_HLIST_NODE(&handler->list);
2335 		rc = smc_wr_rx_register_handler(handler);
2336 		if (rc)
2337 			break;
2338 	}
2339 	return rc;
2340 }
2341