xref: /linux/net/smc/smc_llc.c (revision ab52c59103002b49f2455371e4b9c56ba3ef1781)
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 max_conns;
56 	u8 reserved[8];
57 };
58 
59 #define SMC_LLC_FLAG_ADD_LNK_REJ	0x40
60 #define SMC_LLC_REJ_RSN_NO_ALT_PATH	1
61 
62 struct smc_llc_msg_add_link {		/* type 0x02 */
63 	struct smc_llc_hdr hd;
64 	u8 sender_mac[ETH_ALEN];
65 	u8 reserved2[2];
66 	u8 sender_gid[SMC_GID_SIZE];
67 	u8 sender_qp_num[3];
68 	u8 link_num;
69 #if defined(__BIG_ENDIAN_BITFIELD)
70 	u8 reserved3 : 4,
71 	   qp_mtu   : 4;
72 #elif defined(__LITTLE_ENDIAN_BITFIELD)
73 	u8 qp_mtu   : 4,
74 	   reserved3 : 4;
75 #endif
76 	u8 initial_psn[3];
77 	u8 reserved[8];
78 };
79 
80 struct smc_llc_msg_add_link_cont_rt {
81 	__be32 rmb_key;
82 	__be32 rmb_key_new;
83 	__be64 rmb_vaddr_new;
84 };
85 
86 struct smc_llc_msg_add_link_v2_ext {
87 #if defined(__BIG_ENDIAN_BITFIELD)
88 	u8 v2_direct : 1,
89 	   reserved  : 7;
90 #elif defined(__LITTLE_ENDIAN_BITFIELD)
91 	u8 reserved  : 7,
92 	   v2_direct : 1;
93 #endif
94 	u8 reserved2;
95 	u8 client_target_gid[SMC_GID_SIZE];
96 	u8 reserved3[8];
97 	u16 num_rkeys;
98 	struct smc_llc_msg_add_link_cont_rt rt[];
99 } __packed;		/* format defined in
100 			 * IBM Shared Memory Communications Version 2
101 			 * (https://www.ibm.com/support/pages/node/6326337)
102 			 */
103 
104 struct smc_llc_msg_req_add_link_v2 {
105 	struct smc_llc_hdr hd;
106 	u8 reserved[20];
107 	u8 gid_cnt;
108 	u8 reserved2[3];
109 	u8 gid[][SMC_GID_SIZE];
110 };
111 
112 #define SMC_LLC_RKEYS_PER_CONT_MSG	2
113 
114 struct smc_llc_msg_add_link_cont {	/* type 0x03 */
115 	struct smc_llc_hdr hd;
116 	u8 link_num;
117 	u8 num_rkeys;
118 	u8 reserved2[2];
119 	struct smc_llc_msg_add_link_cont_rt rt[SMC_LLC_RKEYS_PER_CONT_MSG];
120 	u8 reserved[4];
121 } __packed;			/* format defined in RFC7609 */
122 
123 #define SMC_LLC_FLAG_DEL_LINK_ALL	0x40
124 #define SMC_LLC_FLAG_DEL_LINK_ORDERLY	0x20
125 
126 struct smc_llc_msg_del_link {		/* type 0x04 */
127 	struct smc_llc_hdr hd;
128 	u8 link_num;
129 	__be32 reason;
130 	u8 reserved[35];
131 } __packed;			/* format defined in RFC7609 */
132 
133 struct smc_llc_msg_test_link {		/* type 0x07 */
134 	struct smc_llc_hdr hd;
135 	u8 user_data[16];
136 	u8 reserved[24];
137 };
138 
139 struct smc_rmb_rtoken {
140 	union {
141 		u8 num_rkeys;	/* first rtoken byte of CONFIRM LINK msg */
142 				/* is actually the num of rtokens, first */
143 				/* rtoken is always for the current link */
144 		u8 link_id;	/* link id of the rtoken */
145 	};
146 	__be32 rmb_key;
147 	__be64 rmb_vaddr;
148 } __packed;			/* format defined in RFC7609 */
149 
150 #define SMC_LLC_RKEYS_PER_MSG		3
151 #define SMC_LLC_RKEYS_PER_MSG_V2	255
152 
153 struct smc_llc_msg_confirm_rkey {	/* type 0x06 */
154 	struct smc_llc_hdr hd;
155 	struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
156 	u8 reserved;
157 };
158 
159 #define SMC_LLC_DEL_RKEY_MAX	8
160 #define SMC_LLC_FLAG_RKEY_RETRY	0x10
161 #define SMC_LLC_FLAG_RKEY_NEG	0x20
162 
163 struct smc_llc_msg_delete_rkey {	/* type 0x09 */
164 	struct smc_llc_hdr hd;
165 	u8 num_rkeys;
166 	u8 err_mask;
167 	u8 reserved[2];
168 	__be32 rkey[8];
169 	u8 reserved2[4];
170 };
171 
172 struct smc_llc_msg_delete_rkey_v2 {	/* type 0x29 */
173 	struct smc_llc_hdr hd;
174 	u8 num_rkeys;
175 	u8 num_inval_rkeys;
176 	u8 reserved[2];
177 	__be32 rkey[];
178 };
179 
180 union smc_llc_msg {
181 	struct smc_llc_msg_confirm_link confirm_link;
182 	struct smc_llc_msg_add_link add_link;
183 	struct smc_llc_msg_req_add_link_v2 req_add_link;
184 	struct smc_llc_msg_add_link_cont add_link_cont;
185 	struct smc_llc_msg_del_link delete_link;
186 
187 	struct smc_llc_msg_confirm_rkey confirm_rkey;
188 	struct smc_llc_msg_delete_rkey delete_rkey;
189 
190 	struct smc_llc_msg_test_link test_link;
191 	struct {
192 		struct smc_llc_hdr hdr;
193 		u8 data[SMC_LLC_DATA_LEN];
194 	} raw;
195 };
196 
197 #define SMC_LLC_FLAG_RESP		0x80
198 
199 struct smc_llc_qentry {
200 	struct list_head list;
201 	struct smc_link *link;
202 	union smc_llc_msg msg;
203 };
204 
205 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc);
206 
207 struct smc_llc_qentry *smc_llc_flow_qentry_clr(struct smc_llc_flow *flow)
208 {
209 	struct smc_llc_qentry *qentry = flow->qentry;
210 
211 	flow->qentry = NULL;
212 	return qentry;
213 }
214 
215 void smc_llc_flow_qentry_del(struct smc_llc_flow *flow)
216 {
217 	struct smc_llc_qentry *qentry;
218 
219 	if (flow->qentry) {
220 		qentry = flow->qentry;
221 		flow->qentry = NULL;
222 		kfree(qentry);
223 	}
224 }
225 
226 static inline void smc_llc_flow_qentry_set(struct smc_llc_flow *flow,
227 					   struct smc_llc_qentry *qentry)
228 {
229 	flow->qentry = qentry;
230 }
231 
232 static void smc_llc_flow_parallel(struct smc_link_group *lgr, u8 flow_type,
233 				  struct smc_llc_qentry *qentry)
234 {
235 	u8 msg_type = qentry->msg.raw.hdr.common.llc_type;
236 
237 	if ((msg_type == SMC_LLC_ADD_LINK || msg_type == SMC_LLC_DELETE_LINK) &&
238 	    flow_type != msg_type && !lgr->delayed_event) {
239 		lgr->delayed_event = qentry;
240 		return;
241 	}
242 	/* drop parallel or already-in-progress llc requests */
243 	if (flow_type != msg_type)
244 		pr_warn_once("smc: SMC-R lg %*phN net %llu dropped parallel "
245 			     "LLC msg: msg %d flow %d role %d\n",
246 			     SMC_LGR_ID_SIZE, &lgr->id,
247 			     lgr->net->net_cookie,
248 			     qentry->msg.raw.hdr.common.type,
249 			     flow_type, lgr->role);
250 	kfree(qentry);
251 }
252 
253 /* try to start a new llc flow, initiated by an incoming llc msg */
254 static bool smc_llc_flow_start(struct smc_llc_flow *flow,
255 			       struct smc_llc_qentry *qentry)
256 {
257 	struct smc_link_group *lgr = qentry->link->lgr;
258 
259 	spin_lock_bh(&lgr->llc_flow_lock);
260 	if (flow->type) {
261 		/* a flow is already active */
262 		smc_llc_flow_parallel(lgr, flow->type, qentry);
263 		spin_unlock_bh(&lgr->llc_flow_lock);
264 		return false;
265 	}
266 	switch (qentry->msg.raw.hdr.common.llc_type) {
267 	case SMC_LLC_ADD_LINK:
268 		flow->type = SMC_LLC_FLOW_ADD_LINK;
269 		break;
270 	case SMC_LLC_DELETE_LINK:
271 		flow->type = SMC_LLC_FLOW_DEL_LINK;
272 		break;
273 	case SMC_LLC_CONFIRM_RKEY:
274 	case SMC_LLC_DELETE_RKEY:
275 		flow->type = SMC_LLC_FLOW_RKEY;
276 		break;
277 	default:
278 		flow->type = SMC_LLC_FLOW_NONE;
279 	}
280 	smc_llc_flow_qentry_set(flow, qentry);
281 	spin_unlock_bh(&lgr->llc_flow_lock);
282 	return true;
283 }
284 
285 /* start a new local llc flow, wait till current flow finished */
286 int smc_llc_flow_initiate(struct smc_link_group *lgr,
287 			  enum smc_llc_flowtype type)
288 {
289 	enum smc_llc_flowtype allowed_remote = SMC_LLC_FLOW_NONE;
290 	int rc;
291 
292 	/* all flows except confirm_rkey and delete_rkey are exclusive,
293 	 * confirm/delete rkey flows can run concurrently (local and remote)
294 	 */
295 	if (type == SMC_LLC_FLOW_RKEY)
296 		allowed_remote = SMC_LLC_FLOW_RKEY;
297 again:
298 	if (list_empty(&lgr->list))
299 		return -ENODEV;
300 	spin_lock_bh(&lgr->llc_flow_lock);
301 	if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
302 	    (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
303 	     lgr->llc_flow_rmt.type == allowed_remote)) {
304 		lgr->llc_flow_lcl.type = type;
305 		spin_unlock_bh(&lgr->llc_flow_lock);
306 		return 0;
307 	}
308 	spin_unlock_bh(&lgr->llc_flow_lock);
309 	rc = wait_event_timeout(lgr->llc_flow_waiter, (list_empty(&lgr->list) ||
310 				(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
311 				 (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
312 				  lgr->llc_flow_rmt.type == allowed_remote))),
313 				SMC_LLC_WAIT_TIME * 10);
314 	if (!rc)
315 		return -ETIMEDOUT;
316 	goto again;
317 }
318 
319 /* finish the current llc flow */
320 void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow)
321 {
322 	spin_lock_bh(&lgr->llc_flow_lock);
323 	memset(flow, 0, sizeof(*flow));
324 	flow->type = SMC_LLC_FLOW_NONE;
325 	spin_unlock_bh(&lgr->llc_flow_lock);
326 	if (!list_empty(&lgr->list) && lgr->delayed_event &&
327 	    flow == &lgr->llc_flow_lcl)
328 		schedule_work(&lgr->llc_event_work);
329 	else
330 		wake_up(&lgr->llc_flow_waiter);
331 }
332 
333 /* lnk is optional and used for early wakeup when link goes down, useful in
334  * cases where we wait for a response on the link after we sent a request
335  */
336 struct smc_llc_qentry *smc_llc_wait(struct smc_link_group *lgr,
337 				    struct smc_link *lnk,
338 				    int time_out, u8 exp_msg)
339 {
340 	struct smc_llc_flow *flow = &lgr->llc_flow_lcl;
341 	u8 rcv_msg;
342 
343 	wait_event_timeout(lgr->llc_msg_waiter,
344 			   (flow->qentry ||
345 			    (lnk && !smc_link_usable(lnk)) ||
346 			    list_empty(&lgr->list)),
347 			   time_out);
348 	if (!flow->qentry ||
349 	    (lnk && !smc_link_usable(lnk)) || list_empty(&lgr->list)) {
350 		smc_llc_flow_qentry_del(flow);
351 		goto out;
352 	}
353 	rcv_msg = flow->qentry->msg.raw.hdr.common.llc_type;
354 	if (exp_msg && rcv_msg != exp_msg) {
355 		if (exp_msg == SMC_LLC_ADD_LINK &&
356 		    rcv_msg == SMC_LLC_DELETE_LINK) {
357 			/* flow_start will delay the unexpected msg */
358 			smc_llc_flow_start(&lgr->llc_flow_lcl,
359 					   smc_llc_flow_qentry_clr(flow));
360 			return NULL;
361 		}
362 		pr_warn_once("smc: SMC-R lg %*phN net %llu dropped unexpected LLC msg: "
363 			     "msg %d exp %d flow %d role %d flags %x\n",
364 			     SMC_LGR_ID_SIZE, &lgr->id, lgr->net->net_cookie,
365 			     rcv_msg, exp_msg,
366 			     flow->type, lgr->role,
367 			     flow->qentry->msg.raw.hdr.flags);
368 		smc_llc_flow_qentry_del(flow);
369 	}
370 out:
371 	return flow->qentry;
372 }
373 
374 /********************************** send *************************************/
375 
376 struct smc_llc_tx_pend {
377 };
378 
379 /* handler for send/transmission completion of an LLC msg */
380 static void smc_llc_tx_handler(struct smc_wr_tx_pend_priv *pend,
381 			       struct smc_link *link,
382 			       enum ib_wc_status wc_status)
383 {
384 	/* future work: handle wc_status error for recovery and failover */
385 }
386 
387 /**
388  * smc_llc_add_pending_send() - add LLC control message to pending WQE transmits
389  * @link: Pointer to SMC link used for sending LLC control message.
390  * @wr_buf: Out variable returning pointer to work request payload buffer.
391  * @pend: Out variable returning pointer to private pending WR tracking.
392  *	  It's the context the transmit complete handler will get.
393  *
394  * Reserves and pre-fills an entry for a pending work request send/tx.
395  * Used by mid-level smc_llc_send_msg() to prepare for later actual send/tx.
396  * Can sleep due to smc_get_ctrl_buf (if not in softirq context).
397  *
398  * Return: 0 on success, otherwise an error value.
399  */
400 static int smc_llc_add_pending_send(struct smc_link *link,
401 				    struct smc_wr_buf **wr_buf,
402 				    struct smc_wr_tx_pend_priv **pend)
403 {
404 	int rc;
405 
406 	rc = smc_wr_tx_get_free_slot(link, smc_llc_tx_handler, wr_buf, NULL,
407 				     pend);
408 	if (rc < 0)
409 		return rc;
410 	BUILD_BUG_ON_MSG(
411 		sizeof(union smc_llc_msg) > SMC_WR_BUF_SIZE,
412 		"must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)");
413 	BUILD_BUG_ON_MSG(
414 		sizeof(union smc_llc_msg) != SMC_WR_TX_SIZE,
415 		"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()");
416 	BUILD_BUG_ON_MSG(
417 		sizeof(struct smc_llc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
418 		"must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_llc_tx_pend)");
419 	return 0;
420 }
421 
422 static int smc_llc_add_pending_send_v2(struct smc_link *link,
423 				       struct smc_wr_v2_buf **wr_buf,
424 				       struct smc_wr_tx_pend_priv **pend)
425 {
426 	int rc;
427 
428 	rc = smc_wr_tx_get_v2_slot(link, smc_llc_tx_handler, wr_buf, pend);
429 	if (rc < 0)
430 		return rc;
431 	return 0;
432 }
433 
434 static void smc_llc_init_msg_hdr(struct smc_llc_hdr *hdr,
435 				 struct smc_link_group *lgr, size_t len)
436 {
437 	if (lgr->smc_version == SMC_V2) {
438 		hdr->common.llc_version = SMC_V2;
439 		hdr->length_v2 = len;
440 	} else {
441 		hdr->common.llc_version = 0;
442 		hdr->length = len;
443 	}
444 }
445 
446 /* high-level API to send LLC confirm link */
447 int smc_llc_send_confirm_link(struct smc_link *link,
448 			      enum smc_llc_reqresp reqresp)
449 {
450 	struct smc_llc_msg_confirm_link *confllc;
451 	struct smc_wr_tx_pend_priv *pend;
452 	struct smc_wr_buf *wr_buf;
453 	int rc;
454 
455 	if (!smc_wr_tx_link_hold(link))
456 		return -ENOLINK;
457 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
458 	if (rc)
459 		goto put_out;
460 	confllc = (struct smc_llc_msg_confirm_link *)wr_buf;
461 	memset(confllc, 0, sizeof(*confllc));
462 	confllc->hd.common.llc_type = SMC_LLC_CONFIRM_LINK;
463 	smc_llc_init_msg_hdr(&confllc->hd, link->lgr, sizeof(*confllc));
464 	confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
465 	if (reqresp == SMC_LLC_RESP)
466 		confllc->hd.flags |= SMC_LLC_FLAG_RESP;
467 	memcpy(confllc->sender_mac, link->smcibdev->mac[link->ibport - 1],
468 	       ETH_ALEN);
469 	memcpy(confllc->sender_gid, link->gid, SMC_GID_SIZE);
470 	hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
471 	confllc->link_num = link->link_id;
472 	memcpy(confllc->link_uid, link->link_uid, SMC_LGR_ID_SIZE);
473 	confllc->max_links = SMC_LINKS_ADD_LNK_MAX;
474 	if (link->lgr->smc_version == SMC_V2 &&
475 	    link->lgr->peer_smc_release >= SMC_RELEASE_1) {
476 		confllc->max_conns = link->lgr->max_conns;
477 		confllc->max_links = link->lgr->max_links;
478 	}
479 	/* send llc message */
480 	rc = smc_wr_tx_send(link, pend);
481 put_out:
482 	smc_wr_tx_link_put(link);
483 	return rc;
484 }
485 
486 /* send LLC confirm rkey request */
487 static int smc_llc_send_confirm_rkey(struct smc_link *send_link,
488 				     struct smc_buf_desc *rmb_desc)
489 {
490 	struct smc_llc_msg_confirm_rkey *rkeyllc;
491 	struct smc_wr_tx_pend_priv *pend;
492 	struct smc_wr_buf *wr_buf;
493 	struct smc_link *link;
494 	int i, rc, rtok_ix;
495 
496 	if (!smc_wr_tx_link_hold(send_link))
497 		return -ENOLINK;
498 	rc = smc_llc_add_pending_send(send_link, &wr_buf, &pend);
499 	if (rc)
500 		goto put_out;
501 	rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf;
502 	memset(rkeyllc, 0, sizeof(*rkeyllc));
503 	rkeyllc->hd.common.llc_type = SMC_LLC_CONFIRM_RKEY;
504 	smc_llc_init_msg_hdr(&rkeyllc->hd, send_link->lgr, sizeof(*rkeyllc));
505 
506 	rtok_ix = 1;
507 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
508 		link = &send_link->lgr->lnk[i];
509 		if (smc_link_active(link) && link != send_link) {
510 			rkeyllc->rtoken[rtok_ix].link_id = link->link_id;
511 			rkeyllc->rtoken[rtok_ix].rmb_key =
512 				htonl(rmb_desc->mr[link->link_idx]->rkey);
513 			rkeyllc->rtoken[rtok_ix].rmb_vaddr = rmb_desc->is_vm ?
514 				cpu_to_be64((uintptr_t)rmb_desc->cpu_addr) :
515 				cpu_to_be64((u64)sg_dma_address
516 					    (rmb_desc->sgt[link->link_idx].sgl));
517 			rtok_ix++;
518 		}
519 	}
520 	/* rkey of send_link is in rtoken[0] */
521 	rkeyllc->rtoken[0].num_rkeys = rtok_ix - 1;
522 	rkeyllc->rtoken[0].rmb_key =
523 		htonl(rmb_desc->mr[send_link->link_idx]->rkey);
524 	rkeyllc->rtoken[0].rmb_vaddr = rmb_desc->is_vm ?
525 		cpu_to_be64((uintptr_t)rmb_desc->cpu_addr) :
526 		cpu_to_be64((u64)sg_dma_address
527 			    (rmb_desc->sgt[send_link->link_idx].sgl));
528 	/* send llc message */
529 	rc = smc_wr_tx_send(send_link, pend);
530 put_out:
531 	smc_wr_tx_link_put(send_link);
532 	return rc;
533 }
534 
535 /* send LLC delete rkey request */
536 static int smc_llc_send_delete_rkey(struct smc_link *link,
537 				    struct smc_buf_desc *rmb_desc)
538 {
539 	struct smc_llc_msg_delete_rkey *rkeyllc;
540 	struct smc_wr_tx_pend_priv *pend;
541 	struct smc_wr_buf *wr_buf;
542 	int rc;
543 
544 	if (!smc_wr_tx_link_hold(link))
545 		return -ENOLINK;
546 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
547 	if (rc)
548 		goto put_out;
549 	rkeyllc = (struct smc_llc_msg_delete_rkey *)wr_buf;
550 	memset(rkeyllc, 0, sizeof(*rkeyllc));
551 	rkeyllc->hd.common.llc_type = SMC_LLC_DELETE_RKEY;
552 	smc_llc_init_msg_hdr(&rkeyllc->hd, link->lgr, sizeof(*rkeyllc));
553 	rkeyllc->num_rkeys = 1;
554 	rkeyllc->rkey[0] = htonl(rmb_desc->mr[link->link_idx]->rkey);
555 	/* send llc message */
556 	rc = smc_wr_tx_send(link, pend);
557 put_out:
558 	smc_wr_tx_link_put(link);
559 	return rc;
560 }
561 
562 /* return first buffer from any of the next buf lists */
563 static struct smc_buf_desc *_smc_llc_get_next_rmb(struct smc_link_group *lgr,
564 						  int *buf_lst)
565 {
566 	struct smc_buf_desc *buf_pos;
567 
568 	while (*buf_lst < SMC_RMBE_SIZES) {
569 		buf_pos = list_first_entry_or_null(&lgr->rmbs[*buf_lst],
570 						   struct smc_buf_desc, list);
571 		if (buf_pos)
572 			return buf_pos;
573 		(*buf_lst)++;
574 	}
575 	return NULL;
576 }
577 
578 /* return next rmb from buffer lists */
579 static struct smc_buf_desc *smc_llc_get_next_rmb(struct smc_link_group *lgr,
580 						 int *buf_lst,
581 						 struct smc_buf_desc *buf_pos)
582 {
583 	struct smc_buf_desc *buf_next;
584 
585 	if (!buf_pos)
586 		return _smc_llc_get_next_rmb(lgr, buf_lst);
587 
588 	if (list_is_last(&buf_pos->list, &lgr->rmbs[*buf_lst])) {
589 		(*buf_lst)++;
590 		return _smc_llc_get_next_rmb(lgr, buf_lst);
591 	}
592 	buf_next = list_next_entry(buf_pos, list);
593 	return buf_next;
594 }
595 
596 static struct smc_buf_desc *smc_llc_get_first_rmb(struct smc_link_group *lgr,
597 						  int *buf_lst)
598 {
599 	*buf_lst = 0;
600 	return smc_llc_get_next_rmb(lgr, buf_lst, NULL);
601 }
602 
603 static int smc_llc_fill_ext_v2(struct smc_llc_msg_add_link_v2_ext *ext,
604 			       struct smc_link *link, struct smc_link *link_new)
605 {
606 	struct smc_link_group *lgr = link->lgr;
607 	struct smc_buf_desc *buf_pos;
608 	int prim_lnk_idx, lnk_idx, i;
609 	struct smc_buf_desc *rmb;
610 	int len = sizeof(*ext);
611 	int buf_lst;
612 
613 	ext->v2_direct = !lgr->uses_gateway;
614 	memcpy(ext->client_target_gid, link_new->gid, SMC_GID_SIZE);
615 
616 	prim_lnk_idx = link->link_idx;
617 	lnk_idx = link_new->link_idx;
618 	down_write(&lgr->rmbs_lock);
619 	ext->num_rkeys = lgr->conns_num;
620 	if (!ext->num_rkeys)
621 		goto out;
622 	buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
623 	for (i = 0; i < ext->num_rkeys; i++) {
624 		while (buf_pos && !(buf_pos)->used)
625 			buf_pos = smc_llc_get_next_rmb(lgr, &buf_lst, buf_pos);
626 		if (!buf_pos)
627 			break;
628 		rmb = buf_pos;
629 		ext->rt[i].rmb_key = htonl(rmb->mr[prim_lnk_idx]->rkey);
630 		ext->rt[i].rmb_key_new = htonl(rmb->mr[lnk_idx]->rkey);
631 		ext->rt[i].rmb_vaddr_new = rmb->is_vm ?
632 			cpu_to_be64((uintptr_t)rmb->cpu_addr) :
633 			cpu_to_be64((u64)sg_dma_address(rmb->sgt[lnk_idx].sgl));
634 		buf_pos = smc_llc_get_next_rmb(lgr, &buf_lst, buf_pos);
635 	}
636 	len += i * sizeof(ext->rt[0]);
637 out:
638 	up_write(&lgr->rmbs_lock);
639 	return len;
640 }
641 
642 /* send ADD LINK request or response */
643 int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[],
644 			  struct smc_link *link_new,
645 			  enum smc_llc_reqresp reqresp)
646 {
647 	struct smc_llc_msg_add_link_v2_ext *ext = NULL;
648 	struct smc_llc_msg_add_link *addllc;
649 	struct smc_wr_tx_pend_priv *pend;
650 	int len = sizeof(*addllc);
651 	int rc;
652 
653 	if (!smc_wr_tx_link_hold(link))
654 		return -ENOLINK;
655 	if (link->lgr->smc_version == SMC_V2) {
656 		struct smc_wr_v2_buf *wr_buf;
657 
658 		rc = smc_llc_add_pending_send_v2(link, &wr_buf, &pend);
659 		if (rc)
660 			goto put_out;
661 		addllc = (struct smc_llc_msg_add_link *)wr_buf;
662 		ext = (struct smc_llc_msg_add_link_v2_ext *)
663 						&wr_buf->raw[sizeof(*addllc)];
664 		memset(ext, 0, SMC_WR_TX_SIZE);
665 	} else {
666 		struct smc_wr_buf *wr_buf;
667 
668 		rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
669 		if (rc)
670 			goto put_out;
671 		addllc = (struct smc_llc_msg_add_link *)wr_buf;
672 	}
673 
674 	memset(addllc, 0, sizeof(*addllc));
675 	addllc->hd.common.llc_type = SMC_LLC_ADD_LINK;
676 	if (reqresp == SMC_LLC_RESP)
677 		addllc->hd.flags |= SMC_LLC_FLAG_RESP;
678 	memcpy(addllc->sender_mac, mac, ETH_ALEN);
679 	memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
680 	if (link_new) {
681 		addllc->link_num = link_new->link_id;
682 		hton24(addllc->sender_qp_num, link_new->roce_qp->qp_num);
683 		hton24(addllc->initial_psn, link_new->psn_initial);
684 		if (reqresp == SMC_LLC_REQ)
685 			addllc->qp_mtu = link_new->path_mtu;
686 		else
687 			addllc->qp_mtu = min(link_new->path_mtu,
688 					     link_new->peer_mtu);
689 	}
690 	if (ext && link_new)
691 		len += smc_llc_fill_ext_v2(ext, link, link_new);
692 	smc_llc_init_msg_hdr(&addllc->hd, link->lgr, len);
693 	/* send llc message */
694 	if (link->lgr->smc_version == SMC_V2)
695 		rc = smc_wr_tx_v2_send(link, pend, len);
696 	else
697 		rc = smc_wr_tx_send(link, pend);
698 put_out:
699 	smc_wr_tx_link_put(link);
700 	return rc;
701 }
702 
703 /* send DELETE LINK request or response */
704 int smc_llc_send_delete_link(struct smc_link *link, u8 link_del_id,
705 			     enum smc_llc_reqresp reqresp, bool orderly,
706 			     u32 reason)
707 {
708 	struct smc_llc_msg_del_link *delllc;
709 	struct smc_wr_tx_pend_priv *pend;
710 	struct smc_wr_buf *wr_buf;
711 	int rc;
712 
713 	if (!smc_wr_tx_link_hold(link))
714 		return -ENOLINK;
715 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
716 	if (rc)
717 		goto put_out;
718 	delllc = (struct smc_llc_msg_del_link *)wr_buf;
719 
720 	memset(delllc, 0, sizeof(*delllc));
721 	delllc->hd.common.llc_type = SMC_LLC_DELETE_LINK;
722 	smc_llc_init_msg_hdr(&delllc->hd, link->lgr, sizeof(*delllc));
723 	if (reqresp == SMC_LLC_RESP)
724 		delllc->hd.flags |= SMC_LLC_FLAG_RESP;
725 	if (orderly)
726 		delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
727 	if (link_del_id)
728 		delllc->link_num = link_del_id;
729 	else
730 		delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
731 	delllc->reason = htonl(reason);
732 	/* send llc message */
733 	rc = smc_wr_tx_send(link, pend);
734 put_out:
735 	smc_wr_tx_link_put(link);
736 	return rc;
737 }
738 
739 /* send LLC test link request */
740 static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
741 {
742 	struct smc_llc_msg_test_link *testllc;
743 	struct smc_wr_tx_pend_priv *pend;
744 	struct smc_wr_buf *wr_buf;
745 	int rc;
746 
747 	if (!smc_wr_tx_link_hold(link))
748 		return -ENOLINK;
749 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
750 	if (rc)
751 		goto put_out;
752 	testllc = (struct smc_llc_msg_test_link *)wr_buf;
753 	memset(testllc, 0, sizeof(*testllc));
754 	testllc->hd.common.llc_type = SMC_LLC_TEST_LINK;
755 	smc_llc_init_msg_hdr(&testllc->hd, link->lgr, sizeof(*testllc));
756 	memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
757 	/* send llc message */
758 	rc = smc_wr_tx_send(link, pend);
759 put_out:
760 	smc_wr_tx_link_put(link);
761 	return rc;
762 }
763 
764 /* schedule an llc send on link, may wait for buffers */
765 static int smc_llc_send_message(struct smc_link *link, void *llcbuf)
766 {
767 	struct smc_wr_tx_pend_priv *pend;
768 	struct smc_wr_buf *wr_buf;
769 	int rc;
770 
771 	if (!smc_wr_tx_link_hold(link))
772 		return -ENOLINK;
773 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
774 	if (rc)
775 		goto put_out;
776 	memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
777 	rc = smc_wr_tx_send(link, pend);
778 put_out:
779 	smc_wr_tx_link_put(link);
780 	return rc;
781 }
782 
783 /* schedule an llc send on link, may wait for buffers,
784  * and wait for send completion notification.
785  * @return 0 on success
786  */
787 static int smc_llc_send_message_wait(struct smc_link *link, void *llcbuf)
788 {
789 	struct smc_wr_tx_pend_priv *pend;
790 	struct smc_wr_buf *wr_buf;
791 	int rc;
792 
793 	if (!smc_wr_tx_link_hold(link))
794 		return -ENOLINK;
795 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
796 	if (rc)
797 		goto put_out;
798 	memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
799 	rc = smc_wr_tx_send_wait(link, pend, SMC_LLC_WAIT_TIME);
800 put_out:
801 	smc_wr_tx_link_put(link);
802 	return rc;
803 }
804 
805 /********************************* receive ***********************************/
806 
807 static int smc_llc_alloc_alt_link(struct smc_link_group *lgr,
808 				  enum smc_lgr_type lgr_new_t)
809 {
810 	int i;
811 
812 	if (lgr->type == SMC_LGR_SYMMETRIC ||
813 	    (lgr->type != SMC_LGR_SINGLE &&
814 	     (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
815 	      lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)))
816 		return -EMLINK;
817 
818 	if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
819 	    lgr_new_t == SMC_LGR_ASYMMETRIC_PEER) {
820 		for (i = SMC_LINKS_PER_LGR_MAX - 1; i >= 0; i--)
821 			if (lgr->lnk[i].state == SMC_LNK_UNUSED)
822 				return i;
823 	} else {
824 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
825 			if (lgr->lnk[i].state == SMC_LNK_UNUSED)
826 				return i;
827 	}
828 	return -EMLINK;
829 }
830 
831 /* send one add_link_continue msg */
832 static int smc_llc_add_link_cont(struct smc_link *link,
833 				 struct smc_link *link_new, u8 *num_rkeys_todo,
834 				 int *buf_lst, struct smc_buf_desc **buf_pos)
835 {
836 	struct smc_llc_msg_add_link_cont *addc_llc;
837 	struct smc_link_group *lgr = link->lgr;
838 	int prim_lnk_idx, lnk_idx, i, rc;
839 	struct smc_wr_tx_pend_priv *pend;
840 	struct smc_wr_buf *wr_buf;
841 	struct smc_buf_desc *rmb;
842 	u8 n;
843 
844 	if (!smc_wr_tx_link_hold(link))
845 		return -ENOLINK;
846 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
847 	if (rc)
848 		goto put_out;
849 	addc_llc = (struct smc_llc_msg_add_link_cont *)wr_buf;
850 	memset(addc_llc, 0, sizeof(*addc_llc));
851 
852 	prim_lnk_idx = link->link_idx;
853 	lnk_idx = link_new->link_idx;
854 	addc_llc->link_num = link_new->link_id;
855 	addc_llc->num_rkeys = *num_rkeys_todo;
856 	n = *num_rkeys_todo;
857 	for (i = 0; i < min_t(u8, n, SMC_LLC_RKEYS_PER_CONT_MSG); i++) {
858 		while (*buf_pos && !(*buf_pos)->used)
859 			*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
860 		if (!*buf_pos) {
861 			addc_llc->num_rkeys = addc_llc->num_rkeys -
862 					      *num_rkeys_todo;
863 			*num_rkeys_todo = 0;
864 			break;
865 		}
866 		rmb = *buf_pos;
867 
868 		addc_llc->rt[i].rmb_key = htonl(rmb->mr[prim_lnk_idx]->rkey);
869 		addc_llc->rt[i].rmb_key_new = htonl(rmb->mr[lnk_idx]->rkey);
870 		addc_llc->rt[i].rmb_vaddr_new = rmb->is_vm ?
871 			cpu_to_be64((uintptr_t)rmb->cpu_addr) :
872 			cpu_to_be64((u64)sg_dma_address(rmb->sgt[lnk_idx].sgl));
873 
874 		(*num_rkeys_todo)--;
875 		*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
876 	}
877 	addc_llc->hd.common.llc_type = SMC_LLC_ADD_LINK_CONT;
878 	addc_llc->hd.length = sizeof(struct smc_llc_msg_add_link_cont);
879 	if (lgr->role == SMC_CLNT)
880 		addc_llc->hd.flags |= SMC_LLC_FLAG_RESP;
881 	rc = smc_wr_tx_send(link, pend);
882 put_out:
883 	smc_wr_tx_link_put(link);
884 	return rc;
885 }
886 
887 static int smc_llc_cli_rkey_exchange(struct smc_link *link,
888 				     struct smc_link *link_new)
889 {
890 	struct smc_llc_msg_add_link_cont *addc_llc;
891 	struct smc_link_group *lgr = link->lgr;
892 	u8 max, num_rkeys_send, num_rkeys_recv;
893 	struct smc_llc_qentry *qentry;
894 	struct smc_buf_desc *buf_pos;
895 	int buf_lst;
896 	int rc = 0;
897 	int i;
898 
899 	down_write(&lgr->rmbs_lock);
900 	num_rkeys_send = lgr->conns_num;
901 	buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
902 	do {
903 		qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_TIME,
904 				      SMC_LLC_ADD_LINK_CONT);
905 		if (!qentry) {
906 			rc = -ETIMEDOUT;
907 			break;
908 		}
909 		addc_llc = &qentry->msg.add_link_cont;
910 		num_rkeys_recv = addc_llc->num_rkeys;
911 		max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
912 		for (i = 0; i < max; i++) {
913 			smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
914 				       addc_llc->rt[i].rmb_key,
915 				       addc_llc->rt[i].rmb_vaddr_new,
916 				       addc_llc->rt[i].rmb_key_new);
917 			num_rkeys_recv--;
918 		}
919 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
920 		rc = smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
921 					   &buf_lst, &buf_pos);
922 		if (rc)
923 			break;
924 	} while (num_rkeys_send || num_rkeys_recv);
925 
926 	up_write(&lgr->rmbs_lock);
927 	return rc;
928 }
929 
930 /* prepare and send an add link reject response */
931 static int smc_llc_cli_add_link_reject(struct smc_llc_qentry *qentry)
932 {
933 	qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
934 	qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_ADD_LNK_REJ;
935 	qentry->msg.raw.hdr.add_link_rej_rsn = SMC_LLC_REJ_RSN_NO_ALT_PATH;
936 	smc_llc_init_msg_hdr(&qentry->msg.raw.hdr, qentry->link->lgr,
937 			     sizeof(qentry->msg));
938 	return smc_llc_send_message(qentry->link, &qentry->msg);
939 }
940 
941 static int smc_llc_cli_conf_link(struct smc_link *link,
942 				 struct smc_init_info *ini,
943 				 struct smc_link *link_new,
944 				 enum smc_lgr_type lgr_new_t)
945 {
946 	struct smc_link_group *lgr = link->lgr;
947 	struct smc_llc_qentry *qentry = NULL;
948 	int rc = 0;
949 
950 	/* receive CONFIRM LINK request over RoCE fabric */
951 	qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_FIRST_TIME, 0);
952 	if (!qentry) {
953 		rc = smc_llc_send_delete_link(link, link_new->link_id,
954 					      SMC_LLC_REQ, false,
955 					      SMC_LLC_DEL_LOST_PATH);
956 		return -ENOLINK;
957 	}
958 	if (qentry->msg.raw.hdr.common.llc_type != SMC_LLC_CONFIRM_LINK) {
959 		/* received DELETE_LINK instead */
960 		qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
961 		smc_llc_send_message(link, &qentry->msg);
962 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
963 		return -ENOLINK;
964 	}
965 	smc_llc_save_peer_uid(qentry);
966 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
967 
968 	rc = smc_ib_modify_qp_rts(link_new);
969 	if (rc) {
970 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
971 					 false, SMC_LLC_DEL_LOST_PATH);
972 		return -ENOLINK;
973 	}
974 	smc_wr_remember_qp_attr(link_new);
975 
976 	rc = smcr_buf_reg_lgr(link_new);
977 	if (rc) {
978 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
979 					 false, SMC_LLC_DEL_LOST_PATH);
980 		return -ENOLINK;
981 	}
982 
983 	/* send CONFIRM LINK response over RoCE fabric */
984 	rc = smc_llc_send_confirm_link(link_new, SMC_LLC_RESP);
985 	if (rc) {
986 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
987 					 false, SMC_LLC_DEL_LOST_PATH);
988 		return -ENOLINK;
989 	}
990 	smc_llc_link_active(link_new);
991 	if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
992 	    lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
993 		smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
994 	else
995 		smcr_lgr_set_type(lgr, lgr_new_t);
996 	return 0;
997 }
998 
999 static void smc_llc_save_add_link_rkeys(struct smc_link *link,
1000 					struct smc_link *link_new)
1001 {
1002 	struct smc_llc_msg_add_link_v2_ext *ext;
1003 	struct smc_link_group *lgr = link->lgr;
1004 	int max, i;
1005 
1006 	ext = (struct smc_llc_msg_add_link_v2_ext *)((u8 *)lgr->wr_rx_buf_v2 +
1007 						     SMC_WR_TX_SIZE);
1008 	max = min_t(u8, ext->num_rkeys, SMC_LLC_RKEYS_PER_MSG_V2);
1009 	down_write(&lgr->rmbs_lock);
1010 	for (i = 0; i < max; i++) {
1011 		smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1012 			       ext->rt[i].rmb_key,
1013 			       ext->rt[i].rmb_vaddr_new,
1014 			       ext->rt[i].rmb_key_new);
1015 	}
1016 	up_write(&lgr->rmbs_lock);
1017 }
1018 
1019 static void smc_llc_save_add_link_info(struct smc_link *link,
1020 				       struct smc_llc_msg_add_link *add_llc)
1021 {
1022 	link->peer_qpn = ntoh24(add_llc->sender_qp_num);
1023 	memcpy(link->peer_gid, add_llc->sender_gid, SMC_GID_SIZE);
1024 	memcpy(link->peer_mac, add_llc->sender_mac, ETH_ALEN);
1025 	link->peer_psn = ntoh24(add_llc->initial_psn);
1026 	link->peer_mtu = add_llc->qp_mtu;
1027 }
1028 
1029 /* as an SMC client, process an add link request */
1030 int smc_llc_cli_add_link(struct smc_link *link, struct smc_llc_qentry *qentry)
1031 {
1032 	struct smc_llc_msg_add_link *llc = &qentry->msg.add_link;
1033 	enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1034 	struct smc_link_group *lgr = smc_get_lgr(link);
1035 	struct smc_init_info *ini = NULL;
1036 	struct smc_link *lnk_new = NULL;
1037 	int lnk_idx, rc = 0;
1038 
1039 	if (!llc->qp_mtu)
1040 		goto out_reject;
1041 
1042 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1043 	if (!ini) {
1044 		rc = -ENOMEM;
1045 		goto out_reject;
1046 	}
1047 
1048 	if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1) {
1049 		rc = 0;
1050 		goto out_reject;
1051 	}
1052 
1053 	ini->vlan_id = lgr->vlan_id;
1054 	if (lgr->smc_version == SMC_V2) {
1055 		ini->check_smcrv2 = true;
1056 		ini->smcrv2.saddr = lgr->saddr;
1057 		ini->smcrv2.daddr = smc_ib_gid_to_ipv4(llc->sender_gid);
1058 	}
1059 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1060 	if (!memcmp(llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1061 	    (lgr->smc_version == SMC_V2 ||
1062 	     !memcmp(llc->sender_mac, link->peer_mac, ETH_ALEN))) {
1063 		if (!ini->ib_dev && !ini->smcrv2.ib_dev_v2)
1064 			goto out_reject;
1065 		lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1066 	}
1067 	if (lgr->smc_version == SMC_V2 && !ini->smcrv2.ib_dev_v2) {
1068 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1069 		ini->smcrv2.ib_dev_v2 = link->smcibdev;
1070 		ini->smcrv2.ib_port_v2 = link->ibport;
1071 	} else if (lgr->smc_version < SMC_V2 && !ini->ib_dev) {
1072 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1073 		ini->ib_dev = link->smcibdev;
1074 		ini->ib_port = link->ibport;
1075 	}
1076 	lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1077 	if (lnk_idx < 0)
1078 		goto out_reject;
1079 	lnk_new = &lgr->lnk[lnk_idx];
1080 	rc = smcr_link_init(lgr, lnk_new, lnk_idx, ini);
1081 	if (rc)
1082 		goto out_reject;
1083 	smc_llc_save_add_link_info(lnk_new, llc);
1084 	lnk_new->link_id = llc->link_num;	/* SMC server assigns link id */
1085 	smc_llc_link_set_uid(lnk_new);
1086 
1087 	rc = smc_ib_ready_link(lnk_new);
1088 	if (rc)
1089 		goto out_clear_lnk;
1090 
1091 	rc = smcr_buf_map_lgr(lnk_new);
1092 	if (rc)
1093 		goto out_clear_lnk;
1094 
1095 	rc = smc_llc_send_add_link(link,
1096 				   lnk_new->smcibdev->mac[lnk_new->ibport - 1],
1097 				   lnk_new->gid, lnk_new, SMC_LLC_RESP);
1098 	if (rc)
1099 		goto out_clear_lnk;
1100 	if (lgr->smc_version == SMC_V2) {
1101 		smc_llc_save_add_link_rkeys(link, lnk_new);
1102 	} else {
1103 		rc = smc_llc_cli_rkey_exchange(link, lnk_new);
1104 		if (rc) {
1105 			rc = 0;
1106 			goto out_clear_lnk;
1107 		}
1108 	}
1109 	rc = smc_llc_cli_conf_link(link, ini, lnk_new, lgr_new_t);
1110 	if (!rc)
1111 		goto out;
1112 out_clear_lnk:
1113 	lnk_new->state = SMC_LNK_INACTIVE;
1114 	smcr_link_clear(lnk_new, false);
1115 out_reject:
1116 	smc_llc_cli_add_link_reject(qentry);
1117 out:
1118 	kfree(ini);
1119 	kfree(qentry);
1120 	return rc;
1121 }
1122 
1123 static void smc_llc_send_request_add_link(struct smc_link *link)
1124 {
1125 	struct smc_llc_msg_req_add_link_v2 *llc;
1126 	struct smc_wr_tx_pend_priv *pend;
1127 	struct smc_wr_v2_buf *wr_buf;
1128 	struct smc_gidlist gidlist;
1129 	int rc, len, i;
1130 
1131 	if (!smc_wr_tx_link_hold(link))
1132 		return;
1133 	if (link->lgr->type == SMC_LGR_SYMMETRIC ||
1134 	    link->lgr->type == SMC_LGR_ASYMMETRIC_PEER)
1135 		goto put_out;
1136 
1137 	smc_fill_gid_list(link->lgr, &gidlist, link->smcibdev, link->gid);
1138 	if (gidlist.len <= 1)
1139 		goto put_out;
1140 
1141 	rc = smc_llc_add_pending_send_v2(link, &wr_buf, &pend);
1142 	if (rc)
1143 		goto put_out;
1144 	llc = (struct smc_llc_msg_req_add_link_v2 *)wr_buf;
1145 	memset(llc, 0, SMC_WR_TX_SIZE);
1146 
1147 	llc->hd.common.llc_type = SMC_LLC_REQ_ADD_LINK;
1148 	for (i = 0; i < gidlist.len; i++)
1149 		memcpy(llc->gid[i], gidlist.list[i], sizeof(gidlist.list[0]));
1150 	llc->gid_cnt = gidlist.len;
1151 	len = sizeof(*llc) + (gidlist.len * sizeof(gidlist.list[0]));
1152 	smc_llc_init_msg_hdr(&llc->hd, link->lgr, len);
1153 	rc = smc_wr_tx_v2_send(link, pend, len);
1154 	if (!rc)
1155 		/* set REQ_ADD_LINK flow and wait for response from peer */
1156 		link->lgr->llc_flow_lcl.type = SMC_LLC_FLOW_REQ_ADD_LINK;
1157 put_out:
1158 	smc_wr_tx_link_put(link);
1159 }
1160 
1161 /* as an SMC client, invite server to start the add_link processing */
1162 static void smc_llc_cli_add_link_invite(struct smc_link *link,
1163 					struct smc_llc_qentry *qentry)
1164 {
1165 	struct smc_link_group *lgr = smc_get_lgr(link);
1166 	struct smc_init_info *ini = NULL;
1167 
1168 	if (lgr->smc_version == SMC_V2) {
1169 		smc_llc_send_request_add_link(link);
1170 		goto out;
1171 	}
1172 
1173 	if (lgr->type == SMC_LGR_SYMMETRIC ||
1174 	    lgr->type == SMC_LGR_ASYMMETRIC_PEER)
1175 		goto out;
1176 
1177 	if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
1178 		goto out;
1179 
1180 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1181 	if (!ini)
1182 		goto out;
1183 
1184 	ini->vlan_id = lgr->vlan_id;
1185 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1186 	if (!ini->ib_dev)
1187 		goto out;
1188 
1189 	smc_llc_send_add_link(link, ini->ib_dev->mac[ini->ib_port - 1],
1190 			      ini->ib_gid, NULL, SMC_LLC_REQ);
1191 out:
1192 	kfree(ini);
1193 	kfree(qentry);
1194 }
1195 
1196 static bool smc_llc_is_empty_llc_message(union smc_llc_msg *llc)
1197 {
1198 	int i;
1199 
1200 	for (i = 0; i < ARRAY_SIZE(llc->raw.data); i++)
1201 		if (llc->raw.data[i])
1202 			return false;
1203 	return true;
1204 }
1205 
1206 static bool smc_llc_is_local_add_link(union smc_llc_msg *llc)
1207 {
1208 	if (llc->raw.hdr.common.llc_type == SMC_LLC_ADD_LINK &&
1209 	    smc_llc_is_empty_llc_message(llc))
1210 		return true;
1211 	return false;
1212 }
1213 
1214 static void smc_llc_process_cli_add_link(struct smc_link_group *lgr)
1215 {
1216 	struct smc_llc_qentry *qentry;
1217 
1218 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1219 
1220 	down_write(&lgr->llc_conf_mutex);
1221 	if (smc_llc_is_local_add_link(&qentry->msg))
1222 		smc_llc_cli_add_link_invite(qentry->link, qentry);
1223 	else
1224 		smc_llc_cli_add_link(qentry->link, qentry);
1225 	up_write(&lgr->llc_conf_mutex);
1226 }
1227 
1228 static int smc_llc_active_link_count(struct smc_link_group *lgr)
1229 {
1230 	int i, link_count = 0;
1231 
1232 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1233 		if (!smc_link_active(&lgr->lnk[i]))
1234 			continue;
1235 		link_count++;
1236 	}
1237 	return link_count;
1238 }
1239 
1240 /* find the asymmetric link when 3 links are established  */
1241 static struct smc_link *smc_llc_find_asym_link(struct smc_link_group *lgr)
1242 {
1243 	int asym_idx = -ENOENT;
1244 	int i, j, k;
1245 	bool found;
1246 
1247 	/* determine asymmetric link */
1248 	found = false;
1249 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1250 		for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
1251 			if (!smc_link_usable(&lgr->lnk[i]) ||
1252 			    !smc_link_usable(&lgr->lnk[j]))
1253 				continue;
1254 			if (!memcmp(lgr->lnk[i].gid, lgr->lnk[j].gid,
1255 				    SMC_GID_SIZE)) {
1256 				found = true;	/* asym_lnk is i or j */
1257 				break;
1258 			}
1259 		}
1260 		if (found)
1261 			break;
1262 	}
1263 	if (!found)
1264 		goto out; /* no asymmetric link */
1265 	for (k = 0; k < SMC_LINKS_PER_LGR_MAX; k++) {
1266 		if (!smc_link_usable(&lgr->lnk[k]))
1267 			continue;
1268 		if (k != i &&
1269 		    !memcmp(lgr->lnk[i].peer_gid, lgr->lnk[k].peer_gid,
1270 			    SMC_GID_SIZE)) {
1271 			asym_idx = i;
1272 			break;
1273 		}
1274 		if (k != j &&
1275 		    !memcmp(lgr->lnk[j].peer_gid, lgr->lnk[k].peer_gid,
1276 			    SMC_GID_SIZE)) {
1277 			asym_idx = j;
1278 			break;
1279 		}
1280 	}
1281 out:
1282 	return (asym_idx < 0) ? NULL : &lgr->lnk[asym_idx];
1283 }
1284 
1285 static void smc_llc_delete_asym_link(struct smc_link_group *lgr)
1286 {
1287 	struct smc_link *lnk_new = NULL, *lnk_asym;
1288 	struct smc_llc_qentry *qentry;
1289 	int rc;
1290 
1291 	lnk_asym = smc_llc_find_asym_link(lgr);
1292 	if (!lnk_asym)
1293 		return; /* no asymmetric link */
1294 	if (!smc_link_downing(&lnk_asym->state))
1295 		return;
1296 	lnk_new = smc_switch_conns(lgr, lnk_asym, false);
1297 	smc_wr_tx_wait_no_pending_sends(lnk_asym);
1298 	if (!lnk_new)
1299 		goto out_free;
1300 	/* change flow type from ADD_LINK into DEL_LINK */
1301 	lgr->llc_flow_lcl.type = SMC_LLC_FLOW_DEL_LINK;
1302 	rc = smc_llc_send_delete_link(lnk_new, lnk_asym->link_id, SMC_LLC_REQ,
1303 				      true, SMC_LLC_DEL_NO_ASYM_NEEDED);
1304 	if (rc) {
1305 		smcr_link_down_cond(lnk_new);
1306 		goto out_free;
1307 	}
1308 	qentry = smc_llc_wait(lgr, lnk_new, SMC_LLC_WAIT_TIME,
1309 			      SMC_LLC_DELETE_LINK);
1310 	if (!qentry) {
1311 		smcr_link_down_cond(lnk_new);
1312 		goto out_free;
1313 	}
1314 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1315 out_free:
1316 	smcr_link_clear(lnk_asym, true);
1317 }
1318 
1319 static int smc_llc_srv_rkey_exchange(struct smc_link *link,
1320 				     struct smc_link *link_new)
1321 {
1322 	struct smc_llc_msg_add_link_cont *addc_llc;
1323 	struct smc_link_group *lgr = link->lgr;
1324 	u8 max, num_rkeys_send, num_rkeys_recv;
1325 	struct smc_llc_qentry *qentry = NULL;
1326 	struct smc_buf_desc *buf_pos;
1327 	int buf_lst;
1328 	int rc = 0;
1329 	int i;
1330 
1331 	down_write(&lgr->rmbs_lock);
1332 	num_rkeys_send = lgr->conns_num;
1333 	buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
1334 	do {
1335 		smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
1336 				      &buf_lst, &buf_pos);
1337 		qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME,
1338 				      SMC_LLC_ADD_LINK_CONT);
1339 		if (!qentry) {
1340 			rc = -ETIMEDOUT;
1341 			goto out;
1342 		}
1343 		addc_llc = &qentry->msg.add_link_cont;
1344 		num_rkeys_recv = addc_llc->num_rkeys;
1345 		max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
1346 		for (i = 0; i < max; i++) {
1347 			smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1348 				       addc_llc->rt[i].rmb_key,
1349 				       addc_llc->rt[i].rmb_vaddr_new,
1350 				       addc_llc->rt[i].rmb_key_new);
1351 			num_rkeys_recv--;
1352 		}
1353 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1354 	} while (num_rkeys_send || num_rkeys_recv);
1355 out:
1356 	up_write(&lgr->rmbs_lock);
1357 	return rc;
1358 }
1359 
1360 static int smc_llc_srv_conf_link(struct smc_link *link,
1361 				 struct smc_link *link_new,
1362 				 enum smc_lgr_type lgr_new_t)
1363 {
1364 	struct smc_link_group *lgr = link->lgr;
1365 	struct smc_llc_qentry *qentry = NULL;
1366 	int rc;
1367 
1368 	/* send CONFIRM LINK request over the RoCE fabric */
1369 	rc = smc_llc_send_confirm_link(link_new, SMC_LLC_REQ);
1370 	if (rc)
1371 		return -ENOLINK;
1372 	/* receive CONFIRM LINK response over the RoCE fabric */
1373 	qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_FIRST_TIME, 0);
1374 	if (!qentry ||
1375 	    qentry->msg.raw.hdr.common.llc_type != SMC_LLC_CONFIRM_LINK) {
1376 		/* send DELETE LINK */
1377 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
1378 					 false, SMC_LLC_DEL_LOST_PATH);
1379 		if (qentry)
1380 			smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1381 		return -ENOLINK;
1382 	}
1383 	smc_llc_save_peer_uid(qentry);
1384 	smc_llc_link_active(link_new);
1385 	if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
1386 	    lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
1387 		smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
1388 	else
1389 		smcr_lgr_set_type(lgr, lgr_new_t);
1390 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1391 	return 0;
1392 }
1393 
1394 static void smc_llc_send_req_add_link_response(struct smc_llc_qentry *qentry)
1395 {
1396 	qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
1397 	smc_llc_init_msg_hdr(&qentry->msg.raw.hdr, qentry->link->lgr,
1398 			     sizeof(qentry->msg));
1399 	memset(&qentry->msg.raw.data, 0, sizeof(qentry->msg.raw.data));
1400 	smc_llc_send_message(qentry->link, &qentry->msg);
1401 }
1402 
1403 int smc_llc_srv_add_link(struct smc_link *link,
1404 			 struct smc_llc_qentry *req_qentry)
1405 {
1406 	enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1407 	struct smc_link_group *lgr = link->lgr;
1408 	struct smc_llc_msg_add_link *add_llc;
1409 	struct smc_llc_qentry *qentry = NULL;
1410 	bool send_req_add_link_resp = false;
1411 	struct smc_link *link_new = NULL;
1412 	struct smc_init_info *ini = NULL;
1413 	int lnk_idx, rc = 0;
1414 
1415 	if (req_qentry &&
1416 	    req_qentry->msg.raw.hdr.common.llc_type == SMC_LLC_REQ_ADD_LINK)
1417 		send_req_add_link_resp = true;
1418 
1419 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1420 	if (!ini) {
1421 		rc = -ENOMEM;
1422 		goto out;
1423 	}
1424 
1425 	if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1) {
1426 		rc = 0;
1427 		goto out;
1428 	}
1429 
1430 	/* ignore client add link recommendation, start new flow */
1431 	ini->vlan_id = lgr->vlan_id;
1432 	if (lgr->smc_version == SMC_V2) {
1433 		ini->check_smcrv2 = true;
1434 		ini->smcrv2.saddr = lgr->saddr;
1435 		if (send_req_add_link_resp) {
1436 			struct smc_llc_msg_req_add_link_v2 *req_add =
1437 				&req_qentry->msg.req_add_link;
1438 
1439 			ini->smcrv2.daddr = smc_ib_gid_to_ipv4(req_add->gid[0]);
1440 		}
1441 	}
1442 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1443 	if (lgr->smc_version == SMC_V2 && !ini->smcrv2.ib_dev_v2) {
1444 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1445 		ini->smcrv2.ib_dev_v2 = link->smcibdev;
1446 		ini->smcrv2.ib_port_v2 = link->ibport;
1447 	} else if (lgr->smc_version < SMC_V2 && !ini->ib_dev) {
1448 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1449 		ini->ib_dev = link->smcibdev;
1450 		ini->ib_port = link->ibport;
1451 	}
1452 	lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1453 	if (lnk_idx < 0) {
1454 		rc = 0;
1455 		goto out;
1456 	}
1457 
1458 	rc = smcr_link_init(lgr, &lgr->lnk[lnk_idx], lnk_idx, ini);
1459 	if (rc)
1460 		goto out;
1461 	link_new = &lgr->lnk[lnk_idx];
1462 
1463 	rc = smcr_buf_map_lgr(link_new);
1464 	if (rc)
1465 		goto out_err;
1466 
1467 	rc = smc_llc_send_add_link(link,
1468 				   link_new->smcibdev->mac[link_new->ibport-1],
1469 				   link_new->gid, link_new, SMC_LLC_REQ);
1470 	if (rc)
1471 		goto out_err;
1472 	send_req_add_link_resp = false;
1473 	/* receive ADD LINK response over the RoCE fabric */
1474 	qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME, SMC_LLC_ADD_LINK);
1475 	if (!qentry) {
1476 		rc = -ETIMEDOUT;
1477 		goto out_err;
1478 	}
1479 	add_llc = &qentry->msg.add_link;
1480 	if (add_llc->hd.flags & SMC_LLC_FLAG_ADD_LNK_REJ) {
1481 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1482 		rc = -ENOLINK;
1483 		goto out_err;
1484 	}
1485 	if (lgr->type == SMC_LGR_SINGLE &&
1486 	    (!memcmp(add_llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1487 	     (lgr->smc_version == SMC_V2 ||
1488 	      !memcmp(add_llc->sender_mac, link->peer_mac, ETH_ALEN)))) {
1489 		lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1490 	}
1491 	smc_llc_save_add_link_info(link_new, add_llc);
1492 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1493 
1494 	rc = smc_ib_ready_link(link_new);
1495 	if (rc)
1496 		goto out_err;
1497 	rc = smcr_buf_reg_lgr(link_new);
1498 	if (rc)
1499 		goto out_err;
1500 	if (lgr->smc_version == SMC_V2) {
1501 		smc_llc_save_add_link_rkeys(link, link_new);
1502 	} else {
1503 		rc = smc_llc_srv_rkey_exchange(link, link_new);
1504 		if (rc)
1505 			goto out_err;
1506 	}
1507 	rc = smc_llc_srv_conf_link(link, link_new, lgr_new_t);
1508 	if (rc)
1509 		goto out_err;
1510 	kfree(ini);
1511 	return 0;
1512 out_err:
1513 	if (link_new) {
1514 		link_new->state = SMC_LNK_INACTIVE;
1515 		smcr_link_clear(link_new, false);
1516 	}
1517 out:
1518 	kfree(ini);
1519 	if (send_req_add_link_resp)
1520 		smc_llc_send_req_add_link_response(req_qentry);
1521 	return rc;
1522 }
1523 
1524 static void smc_llc_process_srv_add_link(struct smc_link_group *lgr)
1525 {
1526 	struct smc_link *link = lgr->llc_flow_lcl.qentry->link;
1527 	struct smc_llc_qentry *qentry;
1528 	int rc;
1529 
1530 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1531 
1532 	down_write(&lgr->llc_conf_mutex);
1533 	rc = smc_llc_srv_add_link(link, qentry);
1534 	if (!rc && lgr->type == SMC_LGR_SYMMETRIC) {
1535 		/* delete any asymmetric link */
1536 		smc_llc_delete_asym_link(lgr);
1537 	}
1538 	up_write(&lgr->llc_conf_mutex);
1539 	kfree(qentry);
1540 }
1541 
1542 /* enqueue a local add_link req to trigger a new add_link flow */
1543 void smc_llc_add_link_local(struct smc_link *link)
1544 {
1545 	struct smc_llc_msg_add_link add_llc = {};
1546 
1547 	add_llc.hd.common.llc_type = SMC_LLC_ADD_LINK;
1548 	smc_llc_init_msg_hdr(&add_llc.hd, link->lgr, sizeof(add_llc));
1549 	/* no dev and port needed */
1550 	smc_llc_enqueue(link, (union smc_llc_msg *)&add_llc);
1551 }
1552 
1553 /* worker to process an add link message */
1554 static void smc_llc_add_link_work(struct work_struct *work)
1555 {
1556 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1557 						  llc_add_link_work);
1558 
1559 	if (list_empty(&lgr->list)) {
1560 		/* link group is terminating */
1561 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1562 		goto out;
1563 	}
1564 
1565 	if (lgr->role == SMC_CLNT)
1566 		smc_llc_process_cli_add_link(lgr);
1567 	else
1568 		smc_llc_process_srv_add_link(lgr);
1569 out:
1570 	if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_REQ_ADD_LINK)
1571 		smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1572 }
1573 
1574 /* enqueue a local del_link msg to trigger a new del_link flow,
1575  * called only for role SMC_SERV
1576  */
1577 void smc_llc_srv_delete_link_local(struct smc_link *link, u8 del_link_id)
1578 {
1579 	struct smc_llc_msg_del_link del_llc = {};
1580 
1581 	del_llc.hd.common.llc_type = SMC_LLC_DELETE_LINK;
1582 	smc_llc_init_msg_hdr(&del_llc.hd, link->lgr, sizeof(del_llc));
1583 	del_llc.link_num = del_link_id;
1584 	del_llc.reason = htonl(SMC_LLC_DEL_LOST_PATH);
1585 	del_llc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1586 	smc_llc_enqueue(link, (union smc_llc_msg *)&del_llc);
1587 }
1588 
1589 static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
1590 {
1591 	struct smc_link *lnk_del = NULL, *lnk_asym, *lnk;
1592 	struct smc_llc_msg_del_link *del_llc;
1593 	struct smc_llc_qentry *qentry;
1594 	int active_links;
1595 	int lnk_idx;
1596 
1597 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1598 	lnk = qentry->link;
1599 	del_llc = &qentry->msg.delete_link;
1600 
1601 	if (del_llc->hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1602 		smc_lgr_terminate_sched(lgr);
1603 		goto out;
1604 	}
1605 	down_write(&lgr->llc_conf_mutex);
1606 	/* delete single link */
1607 	for (lnk_idx = 0; lnk_idx < SMC_LINKS_PER_LGR_MAX; lnk_idx++) {
1608 		if (lgr->lnk[lnk_idx].link_id != del_llc->link_num)
1609 			continue;
1610 		lnk_del = &lgr->lnk[lnk_idx];
1611 		break;
1612 	}
1613 	del_llc->hd.flags |= SMC_LLC_FLAG_RESP;
1614 	if (!lnk_del) {
1615 		/* link was not found */
1616 		del_llc->reason = htonl(SMC_LLC_DEL_NOLNK);
1617 		smc_llc_send_message(lnk, &qentry->msg);
1618 		goto out_unlock;
1619 	}
1620 	lnk_asym = smc_llc_find_asym_link(lgr);
1621 
1622 	del_llc->reason = 0;
1623 	smc_llc_send_message(lnk, &qentry->msg); /* response */
1624 
1625 	if (smc_link_downing(&lnk_del->state))
1626 		smc_switch_conns(lgr, lnk_del, false);
1627 	smcr_link_clear(lnk_del, true);
1628 
1629 	active_links = smc_llc_active_link_count(lgr);
1630 	if (lnk_del == lnk_asym) {
1631 		/* expected deletion of asym link, don't change lgr state */
1632 	} else if (active_links == 1) {
1633 		smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1634 	} else if (!active_links) {
1635 		smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1636 		smc_lgr_terminate_sched(lgr);
1637 	}
1638 out_unlock:
1639 	up_write(&lgr->llc_conf_mutex);
1640 out:
1641 	kfree(qentry);
1642 }
1643 
1644 /* try to send a DELETE LINK ALL request on any active link,
1645  * waiting for send completion
1646  */
1647 void smc_llc_send_link_delete_all(struct smc_link_group *lgr, bool ord, u32 rsn)
1648 {
1649 	struct smc_llc_msg_del_link delllc = {};
1650 	int i;
1651 
1652 	delllc.hd.common.llc_type = SMC_LLC_DELETE_LINK;
1653 	smc_llc_init_msg_hdr(&delllc.hd, lgr, sizeof(delllc));
1654 	if (ord)
1655 		delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1656 	delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
1657 	delllc.reason = htonl(rsn);
1658 
1659 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1660 		if (!smc_link_sendable(&lgr->lnk[i]))
1661 			continue;
1662 		if (!smc_llc_send_message_wait(&lgr->lnk[i], &delllc))
1663 			break;
1664 	}
1665 }
1666 
1667 static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr)
1668 {
1669 	struct smc_llc_msg_del_link *del_llc;
1670 	struct smc_link *lnk, *lnk_del;
1671 	struct smc_llc_qentry *qentry;
1672 	int active_links;
1673 	int i;
1674 
1675 	down_write(&lgr->llc_conf_mutex);
1676 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1677 	lnk = qentry->link;
1678 	del_llc = &qentry->msg.delete_link;
1679 
1680 	if (qentry->msg.delete_link.hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1681 		/* delete entire lgr */
1682 		smc_llc_send_link_delete_all(lgr, true, ntohl(
1683 					      qentry->msg.delete_link.reason));
1684 		smc_lgr_terminate_sched(lgr);
1685 		goto out;
1686 	}
1687 	/* delete single link */
1688 	lnk_del = NULL;
1689 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1690 		if (lgr->lnk[i].link_id == del_llc->link_num) {
1691 			lnk_del = &lgr->lnk[i];
1692 			break;
1693 		}
1694 	}
1695 	if (!lnk_del)
1696 		goto out; /* asymmetric link already deleted */
1697 
1698 	if (smc_link_downing(&lnk_del->state)) {
1699 		if (smc_switch_conns(lgr, lnk_del, false))
1700 			smc_wr_tx_wait_no_pending_sends(lnk_del);
1701 	}
1702 	if (!list_empty(&lgr->list)) {
1703 		/* qentry is either a request from peer (send it back to
1704 		 * initiate the DELETE_LINK processing), or a locally
1705 		 * enqueued DELETE_LINK request (forward it)
1706 		 */
1707 		if (!smc_llc_send_message(lnk, &qentry->msg)) {
1708 			struct smc_llc_qentry *qentry2;
1709 
1710 			qentry2 = smc_llc_wait(lgr, lnk, SMC_LLC_WAIT_TIME,
1711 					       SMC_LLC_DELETE_LINK);
1712 			if (qentry2)
1713 				smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1714 		}
1715 	}
1716 	smcr_link_clear(lnk_del, true);
1717 
1718 	active_links = smc_llc_active_link_count(lgr);
1719 	if (active_links == 1) {
1720 		smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1721 	} else if (!active_links) {
1722 		smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1723 		smc_lgr_terminate_sched(lgr);
1724 	}
1725 
1726 	if (lgr->type == SMC_LGR_SINGLE && !list_empty(&lgr->list)) {
1727 		/* trigger setup of asymm alt link */
1728 		smc_llc_add_link_local(lnk);
1729 	}
1730 out:
1731 	up_write(&lgr->llc_conf_mutex);
1732 	kfree(qentry);
1733 }
1734 
1735 static void smc_llc_delete_link_work(struct work_struct *work)
1736 {
1737 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1738 						  llc_del_link_work);
1739 
1740 	if (list_empty(&lgr->list)) {
1741 		/* link group is terminating */
1742 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1743 		goto out;
1744 	}
1745 
1746 	if (lgr->role == SMC_CLNT)
1747 		smc_llc_process_cli_delete_link(lgr);
1748 	else
1749 		smc_llc_process_srv_delete_link(lgr);
1750 out:
1751 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1752 }
1753 
1754 /* process a confirm_rkey request from peer, remote flow */
1755 static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr)
1756 {
1757 	struct smc_llc_msg_confirm_rkey *llc;
1758 	struct smc_llc_qentry *qentry;
1759 	struct smc_link *link;
1760 	int num_entries;
1761 	int rk_idx;
1762 	int i;
1763 
1764 	qentry = lgr->llc_flow_rmt.qentry;
1765 	llc = &qentry->msg.confirm_rkey;
1766 	link = qentry->link;
1767 
1768 	num_entries = llc->rtoken[0].num_rkeys;
1769 	if (num_entries > SMC_LLC_RKEYS_PER_MSG)
1770 		goto out_err;
1771 	/* first rkey entry is for receiving link */
1772 	rk_idx = smc_rtoken_add(link,
1773 				llc->rtoken[0].rmb_vaddr,
1774 				llc->rtoken[0].rmb_key);
1775 	if (rk_idx < 0)
1776 		goto out_err;
1777 
1778 	for (i = 1; i <= min_t(u8, num_entries, SMC_LLC_RKEYS_PER_MSG - 1); i++)
1779 		smc_rtoken_set2(lgr, rk_idx, llc->rtoken[i].link_id,
1780 				llc->rtoken[i].rmb_vaddr,
1781 				llc->rtoken[i].rmb_key);
1782 	/* max links is 3 so there is no need to support conf_rkey_cont msgs */
1783 	goto out;
1784 out_err:
1785 	llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1786 	llc->hd.flags |= SMC_LLC_FLAG_RKEY_RETRY;
1787 out:
1788 	llc->hd.flags |= SMC_LLC_FLAG_RESP;
1789 	smc_llc_init_msg_hdr(&llc->hd, link->lgr, sizeof(*llc));
1790 	smc_llc_send_message(link, &qentry->msg);
1791 	smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1792 }
1793 
1794 /* process a delete_rkey request from peer, remote flow */
1795 static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr)
1796 {
1797 	struct smc_llc_msg_delete_rkey *llc;
1798 	struct smc_llc_qentry *qentry;
1799 	struct smc_link *link;
1800 	u8 err_mask = 0;
1801 	int i, max;
1802 
1803 	qentry = lgr->llc_flow_rmt.qentry;
1804 	llc = &qentry->msg.delete_rkey;
1805 	link = qentry->link;
1806 
1807 	if (lgr->smc_version == SMC_V2) {
1808 		struct smc_llc_msg_delete_rkey_v2 *llcv2;
1809 
1810 		memcpy(lgr->wr_rx_buf_v2, llc, sizeof(*llc));
1811 		llcv2 = (struct smc_llc_msg_delete_rkey_v2 *)lgr->wr_rx_buf_v2;
1812 		llcv2->num_inval_rkeys = 0;
1813 
1814 		max = min_t(u8, llcv2->num_rkeys, SMC_LLC_RKEYS_PER_MSG_V2);
1815 		for (i = 0; i < max; i++) {
1816 			if (smc_rtoken_delete(link, llcv2->rkey[i]))
1817 				llcv2->num_inval_rkeys++;
1818 		}
1819 		memset(&llc->rkey[0], 0, sizeof(llc->rkey));
1820 		memset(&llc->reserved2, 0, sizeof(llc->reserved2));
1821 		smc_llc_init_msg_hdr(&llc->hd, link->lgr, sizeof(*llc));
1822 		if (llcv2->num_inval_rkeys) {
1823 			llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1824 			llc->err_mask = llcv2->num_inval_rkeys;
1825 		}
1826 		goto finish;
1827 	}
1828 
1829 	max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
1830 	for (i = 0; i < max; i++) {
1831 		if (smc_rtoken_delete(link, llc->rkey[i]))
1832 			err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
1833 	}
1834 	if (err_mask) {
1835 		llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1836 		llc->err_mask = err_mask;
1837 	}
1838 finish:
1839 	llc->hd.flags |= SMC_LLC_FLAG_RESP;
1840 	smc_llc_send_message(link, &qentry->msg);
1841 	smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1842 }
1843 
1844 static void smc_llc_protocol_violation(struct smc_link_group *lgr, u8 type)
1845 {
1846 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu LLC protocol violation: "
1847 			    "llc_type %d\n", SMC_LGR_ID_SIZE, &lgr->id,
1848 			    lgr->net->net_cookie, type);
1849 	smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_PROT_VIOL);
1850 	smc_lgr_terminate_sched(lgr);
1851 }
1852 
1853 /* flush the llc event queue */
1854 static void smc_llc_event_flush(struct smc_link_group *lgr)
1855 {
1856 	struct smc_llc_qentry *qentry, *q;
1857 
1858 	spin_lock_bh(&lgr->llc_event_q_lock);
1859 	list_for_each_entry_safe(qentry, q, &lgr->llc_event_q, list) {
1860 		list_del_init(&qentry->list);
1861 		kfree(qentry);
1862 	}
1863 	spin_unlock_bh(&lgr->llc_event_q_lock);
1864 }
1865 
1866 static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
1867 {
1868 	union smc_llc_msg *llc = &qentry->msg;
1869 	struct smc_link *link = qentry->link;
1870 	struct smc_link_group *lgr = link->lgr;
1871 
1872 	if (!smc_link_usable(link))
1873 		goto out;
1874 
1875 	switch (llc->raw.hdr.common.llc_type) {
1876 	case SMC_LLC_TEST_LINK:
1877 		llc->test_link.hd.flags |= SMC_LLC_FLAG_RESP;
1878 		smc_llc_send_message(link, llc);
1879 		break;
1880 	case SMC_LLC_ADD_LINK:
1881 		if (list_empty(&lgr->list))
1882 			goto out;	/* lgr is terminating */
1883 		if (lgr->role == SMC_CLNT) {
1884 			if (smc_llc_is_local_add_link(llc)) {
1885 				if (lgr->llc_flow_lcl.type ==
1886 				    SMC_LLC_FLOW_ADD_LINK)
1887 					break;	/* add_link in progress */
1888 				if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1889 						       qentry)) {
1890 					schedule_work(&lgr->llc_add_link_work);
1891 				}
1892 				return;
1893 			}
1894 			if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1895 			    !lgr->llc_flow_lcl.qentry) {
1896 				/* a flow is waiting for this message */
1897 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1898 							qentry);
1899 				wake_up(&lgr->llc_msg_waiter);
1900 				return;
1901 			}
1902 			if (lgr->llc_flow_lcl.type ==
1903 					SMC_LLC_FLOW_REQ_ADD_LINK) {
1904 				/* server started add_link processing */
1905 				lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK;
1906 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1907 							qentry);
1908 				schedule_work(&lgr->llc_add_link_work);
1909 				return;
1910 			}
1911 			if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1912 				schedule_work(&lgr->llc_add_link_work);
1913 			}
1914 		} else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1915 			/* as smc server, handle client suggestion */
1916 			schedule_work(&lgr->llc_add_link_work);
1917 		}
1918 		return;
1919 	case SMC_LLC_CONFIRM_LINK:
1920 	case SMC_LLC_ADD_LINK_CONT:
1921 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1922 			/* a flow is waiting for this message */
1923 			smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1924 			wake_up(&lgr->llc_msg_waiter);
1925 			return;
1926 		}
1927 		break;
1928 	case SMC_LLC_DELETE_LINK:
1929 		if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1930 		    !lgr->llc_flow_lcl.qentry) {
1931 			/* DEL LINK REQ during ADD LINK SEQ */
1932 			smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1933 			wake_up(&lgr->llc_msg_waiter);
1934 		} else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1935 			schedule_work(&lgr->llc_del_link_work);
1936 		}
1937 		return;
1938 	case SMC_LLC_CONFIRM_RKEY:
1939 		/* new request from remote, assign to remote flow */
1940 		if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1941 			/* process here, does not wait for more llc msgs */
1942 			smc_llc_rmt_conf_rkey(lgr);
1943 			smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1944 		}
1945 		return;
1946 	case SMC_LLC_CONFIRM_RKEY_CONT:
1947 		/* not used because max links is 3, and 3 rkeys fit into
1948 		 * one CONFIRM_RKEY message
1949 		 */
1950 		break;
1951 	case SMC_LLC_DELETE_RKEY:
1952 		/* new request from remote, assign to remote flow */
1953 		if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1954 			/* process here, does not wait for more llc msgs */
1955 			smc_llc_rmt_delete_rkey(lgr);
1956 			smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1957 		}
1958 		return;
1959 	case SMC_LLC_REQ_ADD_LINK:
1960 		/* handle response here, smc_llc_flow_stop() cannot be called
1961 		 * in tasklet context
1962 		 */
1963 		if (lgr->role == SMC_CLNT &&
1964 		    lgr->llc_flow_lcl.type == SMC_LLC_FLOW_REQ_ADD_LINK &&
1965 		    (llc->raw.hdr.flags & SMC_LLC_FLAG_RESP)) {
1966 			smc_llc_flow_stop(link->lgr, &lgr->llc_flow_lcl);
1967 		} else if (lgr->role == SMC_SERV) {
1968 			if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1969 				/* as smc server, handle client suggestion */
1970 				lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK;
1971 				schedule_work(&lgr->llc_add_link_work);
1972 			}
1973 			return;
1974 		}
1975 		break;
1976 	default:
1977 		smc_llc_protocol_violation(lgr, llc->raw.hdr.common.type);
1978 		break;
1979 	}
1980 out:
1981 	kfree(qentry);
1982 }
1983 
1984 /* worker to process llc messages on the event queue */
1985 static void smc_llc_event_work(struct work_struct *work)
1986 {
1987 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1988 						  llc_event_work);
1989 	struct smc_llc_qentry *qentry;
1990 
1991 	if (!lgr->llc_flow_lcl.type && lgr->delayed_event) {
1992 		qentry = lgr->delayed_event;
1993 		lgr->delayed_event = NULL;
1994 		if (smc_link_usable(qentry->link))
1995 			smc_llc_event_handler(qentry);
1996 		else
1997 			kfree(qentry);
1998 	}
1999 
2000 again:
2001 	spin_lock_bh(&lgr->llc_event_q_lock);
2002 	if (!list_empty(&lgr->llc_event_q)) {
2003 		qentry = list_first_entry(&lgr->llc_event_q,
2004 					  struct smc_llc_qentry, list);
2005 		list_del_init(&qentry->list);
2006 		spin_unlock_bh(&lgr->llc_event_q_lock);
2007 		smc_llc_event_handler(qentry);
2008 		goto again;
2009 	}
2010 	spin_unlock_bh(&lgr->llc_event_q_lock);
2011 }
2012 
2013 /* process llc responses in tasklet context */
2014 static void smc_llc_rx_response(struct smc_link *link,
2015 				struct smc_llc_qentry *qentry)
2016 {
2017 	enum smc_llc_flowtype flowtype = link->lgr->llc_flow_lcl.type;
2018 	struct smc_llc_flow *flow = &link->lgr->llc_flow_lcl;
2019 	u8 llc_type = qentry->msg.raw.hdr.common.llc_type;
2020 
2021 	switch (llc_type) {
2022 	case SMC_LLC_TEST_LINK:
2023 		if (smc_link_active(link))
2024 			complete(&link->llc_testlink_resp);
2025 		break;
2026 	case SMC_LLC_ADD_LINK:
2027 	case SMC_LLC_ADD_LINK_CONT:
2028 	case SMC_LLC_CONFIRM_LINK:
2029 		if (flowtype != SMC_LLC_FLOW_ADD_LINK || flow->qentry)
2030 			break;	/* drop out-of-flow response */
2031 		goto assign;
2032 	case SMC_LLC_DELETE_LINK:
2033 		if (flowtype != SMC_LLC_FLOW_DEL_LINK || flow->qentry)
2034 			break;	/* drop out-of-flow response */
2035 		goto assign;
2036 	case SMC_LLC_CONFIRM_RKEY:
2037 	case SMC_LLC_DELETE_RKEY:
2038 		if (flowtype != SMC_LLC_FLOW_RKEY || flow->qentry)
2039 			break;	/* drop out-of-flow response */
2040 		goto assign;
2041 	case SMC_LLC_CONFIRM_RKEY_CONT:
2042 		/* not used because max links is 3 */
2043 		break;
2044 	default:
2045 		smc_llc_protocol_violation(link->lgr,
2046 					   qentry->msg.raw.hdr.common.type);
2047 		break;
2048 	}
2049 	kfree(qentry);
2050 	return;
2051 assign:
2052 	/* assign responses to the local flow, we requested them */
2053 	smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
2054 	wake_up(&link->lgr->llc_msg_waiter);
2055 }
2056 
2057 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc)
2058 {
2059 	struct smc_link_group *lgr = link->lgr;
2060 	struct smc_llc_qentry *qentry;
2061 	unsigned long flags;
2062 
2063 	qentry = kmalloc(sizeof(*qentry), GFP_ATOMIC);
2064 	if (!qentry)
2065 		return;
2066 	qentry->link = link;
2067 	INIT_LIST_HEAD(&qentry->list);
2068 	memcpy(&qentry->msg, llc, sizeof(union smc_llc_msg));
2069 
2070 	/* process responses immediately */
2071 	if ((llc->raw.hdr.flags & SMC_LLC_FLAG_RESP) &&
2072 	    llc->raw.hdr.common.llc_type != SMC_LLC_REQ_ADD_LINK) {
2073 		smc_llc_rx_response(link, qentry);
2074 		return;
2075 	}
2076 
2077 	/* add requests to event queue */
2078 	spin_lock_irqsave(&lgr->llc_event_q_lock, flags);
2079 	list_add_tail(&qentry->list, &lgr->llc_event_q);
2080 	spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags);
2081 	queue_work(system_highpri_wq, &lgr->llc_event_work);
2082 }
2083 
2084 /* copy received msg and add it to the event queue */
2085 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
2086 {
2087 	struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
2088 	union smc_llc_msg *llc = buf;
2089 
2090 	if (wc->byte_len < sizeof(*llc))
2091 		return; /* short message */
2092 	if (!llc->raw.hdr.common.llc_version) {
2093 		if (llc->raw.hdr.length != sizeof(*llc))
2094 			return; /* invalid message */
2095 	} else {
2096 		if (llc->raw.hdr.length_v2 < sizeof(*llc))
2097 			return; /* invalid message */
2098 	}
2099 
2100 	smc_llc_enqueue(link, llc);
2101 }
2102 
2103 /***************************** worker, utils *********************************/
2104 
2105 static void smc_llc_testlink_work(struct work_struct *work)
2106 {
2107 	struct smc_link *link = container_of(to_delayed_work(work),
2108 					     struct smc_link, llc_testlink_wrk);
2109 	unsigned long next_interval;
2110 	unsigned long expire_time;
2111 	u8 user_data[16] = { 0 };
2112 	int rc;
2113 
2114 	if (!smc_link_active(link))
2115 		return;		/* don't reschedule worker */
2116 	expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
2117 	if (time_is_after_jiffies(expire_time)) {
2118 		next_interval = expire_time - jiffies;
2119 		goto out;
2120 	}
2121 	reinit_completion(&link->llc_testlink_resp);
2122 	smc_llc_send_test_link(link, user_data);
2123 	/* receive TEST LINK response over RoCE fabric */
2124 	rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
2125 						       SMC_LLC_WAIT_TIME);
2126 	if (!smc_link_active(link))
2127 		return;		/* link state changed */
2128 	if (rc <= 0) {
2129 		smcr_link_down_cond_sched(link);
2130 		return;
2131 	}
2132 	next_interval = link->llc_testlink_time;
2133 out:
2134 	schedule_delayed_work(&link->llc_testlink_wrk, next_interval);
2135 }
2136 
2137 void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
2138 {
2139 	struct net *net = sock_net(smc->clcsock->sk);
2140 
2141 	INIT_WORK(&lgr->llc_event_work, smc_llc_event_work);
2142 	INIT_WORK(&lgr->llc_add_link_work, smc_llc_add_link_work);
2143 	INIT_WORK(&lgr->llc_del_link_work, smc_llc_delete_link_work);
2144 	INIT_LIST_HEAD(&lgr->llc_event_q);
2145 	spin_lock_init(&lgr->llc_event_q_lock);
2146 	spin_lock_init(&lgr->llc_flow_lock);
2147 	init_waitqueue_head(&lgr->llc_flow_waiter);
2148 	init_waitqueue_head(&lgr->llc_msg_waiter);
2149 	init_rwsem(&lgr->llc_conf_mutex);
2150 	lgr->llc_testlink_time = READ_ONCE(net->smc.sysctl_smcr_testlink_time);
2151 }
2152 
2153 /* called after lgr was removed from lgr_list */
2154 void smc_llc_lgr_clear(struct smc_link_group *lgr)
2155 {
2156 	smc_llc_event_flush(lgr);
2157 	wake_up_all(&lgr->llc_flow_waiter);
2158 	wake_up_all(&lgr->llc_msg_waiter);
2159 	cancel_work_sync(&lgr->llc_event_work);
2160 	cancel_work_sync(&lgr->llc_add_link_work);
2161 	cancel_work_sync(&lgr->llc_del_link_work);
2162 	if (lgr->delayed_event) {
2163 		kfree(lgr->delayed_event);
2164 		lgr->delayed_event = NULL;
2165 	}
2166 }
2167 
2168 int smc_llc_link_init(struct smc_link *link)
2169 {
2170 	init_completion(&link->llc_testlink_resp);
2171 	INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
2172 	return 0;
2173 }
2174 
2175 void smc_llc_link_active(struct smc_link *link)
2176 {
2177 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu link added: id %*phN, "
2178 			    "peerid %*phN, ibdev %s, ibport %d\n",
2179 			    SMC_LGR_ID_SIZE, &link->lgr->id,
2180 			    link->lgr->net->net_cookie,
2181 			    SMC_LGR_ID_SIZE, &link->link_uid,
2182 			    SMC_LGR_ID_SIZE, &link->peer_link_uid,
2183 			    link->smcibdev->ibdev->name, link->ibport);
2184 	link->state = SMC_LNK_ACTIVE;
2185 	if (link->lgr->llc_testlink_time) {
2186 		link->llc_testlink_time = link->lgr->llc_testlink_time;
2187 		schedule_delayed_work(&link->llc_testlink_wrk,
2188 				      link->llc_testlink_time);
2189 	}
2190 }
2191 
2192 /* called in worker context */
2193 void smc_llc_link_clear(struct smc_link *link, bool log)
2194 {
2195 	if (log)
2196 		pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu link removed: id %*phN"
2197 				    ", peerid %*phN, ibdev %s, ibport %d\n",
2198 				    SMC_LGR_ID_SIZE, &link->lgr->id,
2199 				    link->lgr->net->net_cookie,
2200 				    SMC_LGR_ID_SIZE, &link->link_uid,
2201 				    SMC_LGR_ID_SIZE, &link->peer_link_uid,
2202 				    link->smcibdev->ibdev->name, link->ibport);
2203 	complete(&link->llc_testlink_resp);
2204 	cancel_delayed_work_sync(&link->llc_testlink_wrk);
2205 }
2206 
2207 /* register a new rtoken at the remote peer (for all links) */
2208 int smc_llc_do_confirm_rkey(struct smc_link *send_link,
2209 			    struct smc_buf_desc *rmb_desc)
2210 {
2211 	struct smc_link_group *lgr = send_link->lgr;
2212 	struct smc_llc_qentry *qentry = NULL;
2213 	int rc = 0;
2214 
2215 	rc = smc_llc_send_confirm_rkey(send_link, rmb_desc);
2216 	if (rc)
2217 		goto out;
2218 	/* receive CONFIRM RKEY response from server over RoCE fabric */
2219 	qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
2220 			      SMC_LLC_CONFIRM_RKEY);
2221 	if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
2222 		rc = -EFAULT;
2223 out:
2224 	if (qentry)
2225 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
2226 	return rc;
2227 }
2228 
2229 /* unregister an rtoken at the remote peer */
2230 int smc_llc_do_delete_rkey(struct smc_link_group *lgr,
2231 			   struct smc_buf_desc *rmb_desc)
2232 {
2233 	struct smc_llc_qentry *qentry = NULL;
2234 	struct smc_link *send_link;
2235 	int rc = 0;
2236 
2237 	send_link = smc_llc_usable_link(lgr);
2238 	if (!send_link)
2239 		return -ENOLINK;
2240 
2241 	/* protected by llc_flow control */
2242 	rc = smc_llc_send_delete_rkey(send_link, rmb_desc);
2243 	if (rc)
2244 		goto out;
2245 	/* receive DELETE RKEY response from server over RoCE fabric */
2246 	qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
2247 			      SMC_LLC_DELETE_RKEY);
2248 	if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
2249 		rc = -EFAULT;
2250 out:
2251 	if (qentry)
2252 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
2253 	return rc;
2254 }
2255 
2256 void smc_llc_link_set_uid(struct smc_link *link)
2257 {
2258 	__be32 link_uid;
2259 
2260 	link_uid = htonl(*((u32 *)link->lgr->id) + link->link_id);
2261 	memcpy(link->link_uid, &link_uid, SMC_LGR_ID_SIZE);
2262 }
2263 
2264 /* save peers link user id, used for debug purposes */
2265 void smc_llc_save_peer_uid(struct smc_llc_qentry *qentry)
2266 {
2267 	memcpy(qentry->link->peer_link_uid, qentry->msg.confirm_link.link_uid,
2268 	       SMC_LGR_ID_SIZE);
2269 }
2270 
2271 /* evaluate confirm link request or response */
2272 int smc_llc_eval_conf_link(struct smc_llc_qentry *qentry,
2273 			   enum smc_llc_reqresp type)
2274 {
2275 	if (type == SMC_LLC_REQ) {	/* SMC server assigns link_id */
2276 		qentry->link->link_id = qentry->msg.confirm_link.link_num;
2277 		smc_llc_link_set_uid(qentry->link);
2278 	}
2279 	if (!(qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_NO_RMBE_EYEC))
2280 		return -ENOTSUPP;
2281 	return 0;
2282 }
2283 
2284 /***************************** init, exit, misc ******************************/
2285 
2286 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
2287 	{
2288 		.handler	= smc_llc_rx_handler,
2289 		.type		= SMC_LLC_CONFIRM_LINK
2290 	},
2291 	{
2292 		.handler	= smc_llc_rx_handler,
2293 		.type		= SMC_LLC_TEST_LINK
2294 	},
2295 	{
2296 		.handler	= smc_llc_rx_handler,
2297 		.type		= SMC_LLC_ADD_LINK
2298 	},
2299 	{
2300 		.handler	= smc_llc_rx_handler,
2301 		.type		= SMC_LLC_ADD_LINK_CONT
2302 	},
2303 	{
2304 		.handler	= smc_llc_rx_handler,
2305 		.type		= SMC_LLC_DELETE_LINK
2306 	},
2307 	{
2308 		.handler	= smc_llc_rx_handler,
2309 		.type		= SMC_LLC_CONFIRM_RKEY
2310 	},
2311 	{
2312 		.handler	= smc_llc_rx_handler,
2313 		.type		= SMC_LLC_CONFIRM_RKEY_CONT
2314 	},
2315 	{
2316 		.handler	= smc_llc_rx_handler,
2317 		.type		= SMC_LLC_DELETE_RKEY
2318 	},
2319 	/* V2 types */
2320 	{
2321 		.handler	= smc_llc_rx_handler,
2322 		.type		= SMC_LLC_CONFIRM_LINK_V2
2323 	},
2324 	{
2325 		.handler	= smc_llc_rx_handler,
2326 		.type		= SMC_LLC_TEST_LINK_V2
2327 	},
2328 	{
2329 		.handler	= smc_llc_rx_handler,
2330 		.type		= SMC_LLC_ADD_LINK_V2
2331 	},
2332 	{
2333 		.handler	= smc_llc_rx_handler,
2334 		.type		= SMC_LLC_DELETE_LINK_V2
2335 	},
2336 	{
2337 		.handler	= smc_llc_rx_handler,
2338 		.type		= SMC_LLC_REQ_ADD_LINK_V2
2339 	},
2340 	{
2341 		.handler	= smc_llc_rx_handler,
2342 		.type		= SMC_LLC_CONFIRM_RKEY_V2
2343 	},
2344 	{
2345 		.handler	= smc_llc_rx_handler,
2346 		.type		= SMC_LLC_DELETE_RKEY_V2
2347 	},
2348 	{
2349 		.handler	= NULL,
2350 	}
2351 };
2352 
2353 int __init smc_llc_init(void)
2354 {
2355 	struct smc_wr_rx_handler *handler;
2356 	int rc = 0;
2357 
2358 	for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
2359 		INIT_HLIST_NODE(&handler->list);
2360 		rc = smc_wr_rx_register_handler(handler);
2361 		if (rc)
2362 			break;
2363 	}
2364 	return rc;
2365 }
2366