xref: /openbmc/linux/net/smc/smc_llc.c (revision 0545810f)
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[link->link_idx]->rkey);
509 			rkeyllc->rtoken[rtok_ix].rmb_vaddr = rmb_desc->is_vm ?
510 				cpu_to_be64((uintptr_t)rmb_desc->cpu_addr) :
511 				cpu_to_be64((u64)sg_dma_address
512 					    (rmb_desc->sgt[link->link_idx].sgl));
513 			rtok_ix++;
514 		}
515 	}
516 	/* rkey of send_link is in rtoken[0] */
517 	rkeyllc->rtoken[0].num_rkeys = rtok_ix - 1;
518 	rkeyllc->rtoken[0].rmb_key =
519 		htonl(rmb_desc->mr[send_link->link_idx]->rkey);
520 	rkeyllc->rtoken[0].rmb_vaddr = rmb_desc->is_vm ?
521 		cpu_to_be64((uintptr_t)rmb_desc->cpu_addr) :
522 		cpu_to_be64((u64)sg_dma_address
523 			    (rmb_desc->sgt[send_link->link_idx].sgl));
524 	/* send llc message */
525 	rc = smc_wr_tx_send(send_link, pend);
526 put_out:
527 	smc_wr_tx_link_put(send_link);
528 	return rc;
529 }
530 
531 /* send LLC delete rkey request */
532 static int smc_llc_send_delete_rkey(struct smc_link *link,
533 				    struct smc_buf_desc *rmb_desc)
534 {
535 	struct smc_llc_msg_delete_rkey *rkeyllc;
536 	struct smc_wr_tx_pend_priv *pend;
537 	struct smc_wr_buf *wr_buf;
538 	int rc;
539 
540 	if (!smc_wr_tx_link_hold(link))
541 		return -ENOLINK;
542 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
543 	if (rc)
544 		goto put_out;
545 	rkeyllc = (struct smc_llc_msg_delete_rkey *)wr_buf;
546 	memset(rkeyllc, 0, sizeof(*rkeyllc));
547 	rkeyllc->hd.common.llc_type = SMC_LLC_DELETE_RKEY;
548 	smc_llc_init_msg_hdr(&rkeyllc->hd, link->lgr, sizeof(*rkeyllc));
549 	rkeyllc->num_rkeys = 1;
550 	rkeyllc->rkey[0] = htonl(rmb_desc->mr[link->link_idx]->rkey);
551 	/* send llc message */
552 	rc = smc_wr_tx_send(link, pend);
553 put_out:
554 	smc_wr_tx_link_put(link);
555 	return rc;
556 }
557 
558 /* return first buffer from any of the next buf lists */
559 static struct smc_buf_desc *_smc_llc_get_next_rmb(struct smc_link_group *lgr,
560 						  int *buf_lst)
561 {
562 	struct smc_buf_desc *buf_pos;
563 
564 	while (*buf_lst < SMC_RMBE_SIZES) {
565 		buf_pos = list_first_entry_or_null(&lgr->rmbs[*buf_lst],
566 						   struct smc_buf_desc, list);
567 		if (buf_pos)
568 			return buf_pos;
569 		(*buf_lst)++;
570 	}
571 	return NULL;
572 }
573 
574 /* return next rmb from buffer lists */
575 static struct smc_buf_desc *smc_llc_get_next_rmb(struct smc_link_group *lgr,
576 						 int *buf_lst,
577 						 struct smc_buf_desc *buf_pos)
578 {
579 	struct smc_buf_desc *buf_next;
580 
581 	if (!buf_pos || list_is_last(&buf_pos->list, &lgr->rmbs[*buf_lst])) {
582 		(*buf_lst)++;
583 		return _smc_llc_get_next_rmb(lgr, buf_lst);
584 	}
585 	buf_next = list_next_entry(buf_pos, list);
586 	return buf_next;
587 }
588 
589 static struct smc_buf_desc *smc_llc_get_first_rmb(struct smc_link_group *lgr,
590 						  int *buf_lst)
591 {
592 	*buf_lst = 0;
593 	return smc_llc_get_next_rmb(lgr, buf_lst, NULL);
594 }
595 
596 static int smc_llc_fill_ext_v2(struct smc_llc_msg_add_link_v2_ext *ext,
597 			       struct smc_link *link, struct smc_link *link_new)
598 {
599 	struct smc_link_group *lgr = link->lgr;
600 	struct smc_buf_desc *buf_pos;
601 	int prim_lnk_idx, lnk_idx, i;
602 	struct smc_buf_desc *rmb;
603 	int len = sizeof(*ext);
604 	int buf_lst;
605 
606 	ext->v2_direct = !lgr->uses_gateway;
607 	memcpy(ext->client_target_gid, link_new->gid, SMC_GID_SIZE);
608 
609 	prim_lnk_idx = link->link_idx;
610 	lnk_idx = link_new->link_idx;
611 	down_write(&lgr->rmbs_lock);
612 	ext->num_rkeys = lgr->conns_num;
613 	if (!ext->num_rkeys)
614 		goto out;
615 	buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
616 	for (i = 0; i < ext->num_rkeys; i++) {
617 		if (!buf_pos)
618 			break;
619 		rmb = buf_pos;
620 		ext->rt[i].rmb_key = htonl(rmb->mr[prim_lnk_idx]->rkey);
621 		ext->rt[i].rmb_key_new = htonl(rmb->mr[lnk_idx]->rkey);
622 		ext->rt[i].rmb_vaddr_new = rmb->is_vm ?
623 			cpu_to_be64((uintptr_t)rmb->cpu_addr) :
624 			cpu_to_be64((u64)sg_dma_address(rmb->sgt[lnk_idx].sgl));
625 		buf_pos = smc_llc_get_next_rmb(lgr, &buf_lst, buf_pos);
626 		while (buf_pos && !(buf_pos)->used)
627 			buf_pos = smc_llc_get_next_rmb(lgr, &buf_lst, buf_pos);
628 	}
629 	len += i * sizeof(ext->rt[0]);
630 out:
631 	up_write(&lgr->rmbs_lock);
632 	return len;
633 }
634 
635 /* send ADD LINK request or response */
636 int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[],
637 			  struct smc_link *link_new,
638 			  enum smc_llc_reqresp reqresp)
639 {
640 	struct smc_llc_msg_add_link_v2_ext *ext = NULL;
641 	struct smc_llc_msg_add_link *addllc;
642 	struct smc_wr_tx_pend_priv *pend;
643 	int len = sizeof(*addllc);
644 	int rc;
645 
646 	if (!smc_wr_tx_link_hold(link))
647 		return -ENOLINK;
648 	if (link->lgr->smc_version == SMC_V2) {
649 		struct smc_wr_v2_buf *wr_buf;
650 
651 		rc = smc_llc_add_pending_send_v2(link, &wr_buf, &pend);
652 		if (rc)
653 			goto put_out;
654 		addllc = (struct smc_llc_msg_add_link *)wr_buf;
655 		ext = (struct smc_llc_msg_add_link_v2_ext *)
656 						&wr_buf->raw[sizeof(*addllc)];
657 		memset(ext, 0, SMC_WR_TX_SIZE);
658 	} else {
659 		struct smc_wr_buf *wr_buf;
660 
661 		rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
662 		if (rc)
663 			goto put_out;
664 		addllc = (struct smc_llc_msg_add_link *)wr_buf;
665 	}
666 
667 	memset(addllc, 0, sizeof(*addllc));
668 	addllc->hd.common.llc_type = SMC_LLC_ADD_LINK;
669 	if (reqresp == SMC_LLC_RESP)
670 		addllc->hd.flags |= SMC_LLC_FLAG_RESP;
671 	memcpy(addllc->sender_mac, mac, ETH_ALEN);
672 	memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
673 	if (link_new) {
674 		addllc->link_num = link_new->link_id;
675 		hton24(addllc->sender_qp_num, link_new->roce_qp->qp_num);
676 		hton24(addllc->initial_psn, link_new->psn_initial);
677 		if (reqresp == SMC_LLC_REQ)
678 			addllc->qp_mtu = link_new->path_mtu;
679 		else
680 			addllc->qp_mtu = min(link_new->path_mtu,
681 					     link_new->peer_mtu);
682 	}
683 	if (ext && link_new)
684 		len += smc_llc_fill_ext_v2(ext, link, link_new);
685 	smc_llc_init_msg_hdr(&addllc->hd, link->lgr, len);
686 	/* send llc message */
687 	if (link->lgr->smc_version == SMC_V2)
688 		rc = smc_wr_tx_v2_send(link, pend, len);
689 	else
690 		rc = smc_wr_tx_send(link, pend);
691 put_out:
692 	smc_wr_tx_link_put(link);
693 	return rc;
694 }
695 
696 /* send DELETE LINK request or response */
697 int smc_llc_send_delete_link(struct smc_link *link, u8 link_del_id,
698 			     enum smc_llc_reqresp reqresp, bool orderly,
699 			     u32 reason)
700 {
701 	struct smc_llc_msg_del_link *delllc;
702 	struct smc_wr_tx_pend_priv *pend;
703 	struct smc_wr_buf *wr_buf;
704 	int rc;
705 
706 	if (!smc_wr_tx_link_hold(link))
707 		return -ENOLINK;
708 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
709 	if (rc)
710 		goto put_out;
711 	delllc = (struct smc_llc_msg_del_link *)wr_buf;
712 
713 	memset(delllc, 0, sizeof(*delllc));
714 	delllc->hd.common.llc_type = SMC_LLC_DELETE_LINK;
715 	smc_llc_init_msg_hdr(&delllc->hd, link->lgr, sizeof(*delllc));
716 	if (reqresp == SMC_LLC_RESP)
717 		delllc->hd.flags |= SMC_LLC_FLAG_RESP;
718 	if (orderly)
719 		delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
720 	if (link_del_id)
721 		delllc->link_num = link_del_id;
722 	else
723 		delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
724 	delllc->reason = htonl(reason);
725 	/* send llc message */
726 	rc = smc_wr_tx_send(link, pend);
727 put_out:
728 	smc_wr_tx_link_put(link);
729 	return rc;
730 }
731 
732 /* send LLC test link request */
733 static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
734 {
735 	struct smc_llc_msg_test_link *testllc;
736 	struct smc_wr_tx_pend_priv *pend;
737 	struct smc_wr_buf *wr_buf;
738 	int rc;
739 
740 	if (!smc_wr_tx_link_hold(link))
741 		return -ENOLINK;
742 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
743 	if (rc)
744 		goto put_out;
745 	testllc = (struct smc_llc_msg_test_link *)wr_buf;
746 	memset(testllc, 0, sizeof(*testllc));
747 	testllc->hd.common.llc_type = SMC_LLC_TEST_LINK;
748 	smc_llc_init_msg_hdr(&testllc->hd, link->lgr, sizeof(*testllc));
749 	memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
750 	/* send llc message */
751 	rc = smc_wr_tx_send(link, pend);
752 put_out:
753 	smc_wr_tx_link_put(link);
754 	return rc;
755 }
756 
757 /* schedule an llc send on link, may wait for buffers */
758 static int smc_llc_send_message(struct smc_link *link, void *llcbuf)
759 {
760 	struct smc_wr_tx_pend_priv *pend;
761 	struct smc_wr_buf *wr_buf;
762 	int rc;
763 
764 	if (!smc_wr_tx_link_hold(link))
765 		return -ENOLINK;
766 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
767 	if (rc)
768 		goto put_out;
769 	memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
770 	rc = smc_wr_tx_send(link, pend);
771 put_out:
772 	smc_wr_tx_link_put(link);
773 	return rc;
774 }
775 
776 /* schedule an llc send on link, may wait for buffers,
777  * and wait for send completion notification.
778  * @return 0 on success
779  */
780 static int smc_llc_send_message_wait(struct smc_link *link, void *llcbuf)
781 {
782 	struct smc_wr_tx_pend_priv *pend;
783 	struct smc_wr_buf *wr_buf;
784 	int rc;
785 
786 	if (!smc_wr_tx_link_hold(link))
787 		return -ENOLINK;
788 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
789 	if (rc)
790 		goto put_out;
791 	memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
792 	rc = smc_wr_tx_send_wait(link, pend, SMC_LLC_WAIT_TIME);
793 put_out:
794 	smc_wr_tx_link_put(link);
795 	return rc;
796 }
797 
798 /********************************* receive ***********************************/
799 
800 static int smc_llc_alloc_alt_link(struct smc_link_group *lgr,
801 				  enum smc_lgr_type lgr_new_t)
802 {
803 	int i;
804 
805 	if (lgr->type == SMC_LGR_SYMMETRIC ||
806 	    (lgr->type != SMC_LGR_SINGLE &&
807 	     (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
808 	      lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)))
809 		return -EMLINK;
810 
811 	if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
812 	    lgr_new_t == SMC_LGR_ASYMMETRIC_PEER) {
813 		for (i = SMC_LINKS_PER_LGR_MAX - 1; i >= 0; i--)
814 			if (lgr->lnk[i].state == SMC_LNK_UNUSED)
815 				return i;
816 	} else {
817 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
818 			if (lgr->lnk[i].state == SMC_LNK_UNUSED)
819 				return i;
820 	}
821 	return -EMLINK;
822 }
823 
824 /* send one add_link_continue msg */
825 static int smc_llc_add_link_cont(struct smc_link *link,
826 				 struct smc_link *link_new, u8 *num_rkeys_todo,
827 				 int *buf_lst, struct smc_buf_desc **buf_pos)
828 {
829 	struct smc_llc_msg_add_link_cont *addc_llc;
830 	struct smc_link_group *lgr = link->lgr;
831 	int prim_lnk_idx, lnk_idx, i, rc;
832 	struct smc_wr_tx_pend_priv *pend;
833 	struct smc_wr_buf *wr_buf;
834 	struct smc_buf_desc *rmb;
835 	u8 n;
836 
837 	if (!smc_wr_tx_link_hold(link))
838 		return -ENOLINK;
839 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
840 	if (rc)
841 		goto put_out;
842 	addc_llc = (struct smc_llc_msg_add_link_cont *)wr_buf;
843 	memset(addc_llc, 0, sizeof(*addc_llc));
844 
845 	prim_lnk_idx = link->link_idx;
846 	lnk_idx = link_new->link_idx;
847 	addc_llc->link_num = link_new->link_id;
848 	addc_llc->num_rkeys = *num_rkeys_todo;
849 	n = *num_rkeys_todo;
850 	for (i = 0; i < min_t(u8, n, SMC_LLC_RKEYS_PER_CONT_MSG); i++) {
851 		if (!*buf_pos) {
852 			addc_llc->num_rkeys = addc_llc->num_rkeys -
853 					      *num_rkeys_todo;
854 			*num_rkeys_todo = 0;
855 			break;
856 		}
857 		rmb = *buf_pos;
858 
859 		addc_llc->rt[i].rmb_key = htonl(rmb->mr[prim_lnk_idx]->rkey);
860 		addc_llc->rt[i].rmb_key_new = htonl(rmb->mr[lnk_idx]->rkey);
861 		addc_llc->rt[i].rmb_vaddr_new = rmb->is_vm ?
862 			cpu_to_be64((uintptr_t)rmb->cpu_addr) :
863 			cpu_to_be64((u64)sg_dma_address(rmb->sgt[lnk_idx].sgl));
864 
865 		(*num_rkeys_todo)--;
866 		*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
867 		while (*buf_pos && !(*buf_pos)->used)
868 			*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
869 	}
870 	addc_llc->hd.common.llc_type = SMC_LLC_ADD_LINK_CONT;
871 	addc_llc->hd.length = sizeof(struct smc_llc_msg_add_link_cont);
872 	if (lgr->role == SMC_CLNT)
873 		addc_llc->hd.flags |= SMC_LLC_FLAG_RESP;
874 	rc = smc_wr_tx_send(link, pend);
875 put_out:
876 	smc_wr_tx_link_put(link);
877 	return rc;
878 }
879 
880 static int smc_llc_cli_rkey_exchange(struct smc_link *link,
881 				     struct smc_link *link_new)
882 {
883 	struct smc_llc_msg_add_link_cont *addc_llc;
884 	struct smc_link_group *lgr = link->lgr;
885 	u8 max, num_rkeys_send, num_rkeys_recv;
886 	struct smc_llc_qentry *qentry;
887 	struct smc_buf_desc *buf_pos;
888 	int buf_lst;
889 	int rc = 0;
890 	int i;
891 
892 	down_write(&lgr->rmbs_lock);
893 	num_rkeys_send = lgr->conns_num;
894 	buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
895 	do {
896 		qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_TIME,
897 				      SMC_LLC_ADD_LINK_CONT);
898 		if (!qentry) {
899 			rc = -ETIMEDOUT;
900 			break;
901 		}
902 		addc_llc = &qentry->msg.add_link_cont;
903 		num_rkeys_recv = addc_llc->num_rkeys;
904 		max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
905 		for (i = 0; i < max; i++) {
906 			smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
907 				       addc_llc->rt[i].rmb_key,
908 				       addc_llc->rt[i].rmb_vaddr_new,
909 				       addc_llc->rt[i].rmb_key_new);
910 			num_rkeys_recv--;
911 		}
912 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
913 		rc = smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
914 					   &buf_lst, &buf_pos);
915 		if (rc)
916 			break;
917 	} while (num_rkeys_send || num_rkeys_recv);
918 
919 	up_write(&lgr->rmbs_lock);
920 	return rc;
921 }
922 
923 /* prepare and send an add link reject response */
924 static int smc_llc_cli_add_link_reject(struct smc_llc_qentry *qentry)
925 {
926 	qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
927 	qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_ADD_LNK_REJ;
928 	qentry->msg.raw.hdr.add_link_rej_rsn = SMC_LLC_REJ_RSN_NO_ALT_PATH;
929 	smc_llc_init_msg_hdr(&qentry->msg.raw.hdr, qentry->link->lgr,
930 			     sizeof(qentry->msg));
931 	return smc_llc_send_message(qentry->link, &qentry->msg);
932 }
933 
934 static int smc_llc_cli_conf_link(struct smc_link *link,
935 				 struct smc_init_info *ini,
936 				 struct smc_link *link_new,
937 				 enum smc_lgr_type lgr_new_t)
938 {
939 	struct smc_link_group *lgr = link->lgr;
940 	struct smc_llc_qentry *qentry = NULL;
941 	int rc = 0;
942 
943 	/* receive CONFIRM LINK request over RoCE fabric */
944 	qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_FIRST_TIME, 0);
945 	if (!qentry) {
946 		rc = smc_llc_send_delete_link(link, link_new->link_id,
947 					      SMC_LLC_REQ, false,
948 					      SMC_LLC_DEL_LOST_PATH);
949 		return -ENOLINK;
950 	}
951 	if (qentry->msg.raw.hdr.common.llc_type != SMC_LLC_CONFIRM_LINK) {
952 		/* received DELETE_LINK instead */
953 		qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
954 		smc_llc_send_message(link, &qentry->msg);
955 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
956 		return -ENOLINK;
957 	}
958 	smc_llc_save_peer_uid(qentry);
959 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
960 
961 	rc = smc_ib_modify_qp_rts(link_new);
962 	if (rc) {
963 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
964 					 false, SMC_LLC_DEL_LOST_PATH);
965 		return -ENOLINK;
966 	}
967 	smc_wr_remember_qp_attr(link_new);
968 
969 	rc = smcr_buf_reg_lgr(link_new);
970 	if (rc) {
971 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
972 					 false, SMC_LLC_DEL_LOST_PATH);
973 		return -ENOLINK;
974 	}
975 
976 	/* send CONFIRM LINK response over RoCE fabric */
977 	rc = smc_llc_send_confirm_link(link_new, SMC_LLC_RESP);
978 	if (rc) {
979 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
980 					 false, SMC_LLC_DEL_LOST_PATH);
981 		return -ENOLINK;
982 	}
983 	smc_llc_link_active(link_new);
984 	if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
985 	    lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
986 		smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
987 	else
988 		smcr_lgr_set_type(lgr, lgr_new_t);
989 	return 0;
990 }
991 
992 static void smc_llc_save_add_link_rkeys(struct smc_link *link,
993 					struct smc_link *link_new)
994 {
995 	struct smc_llc_msg_add_link_v2_ext *ext;
996 	struct smc_link_group *lgr = link->lgr;
997 	int max, i;
998 
999 	ext = (struct smc_llc_msg_add_link_v2_ext *)((u8 *)lgr->wr_rx_buf_v2 +
1000 						     SMC_WR_TX_SIZE);
1001 	max = min_t(u8, ext->num_rkeys, SMC_LLC_RKEYS_PER_MSG_V2);
1002 	down_write(&lgr->rmbs_lock);
1003 	for (i = 0; i < max; i++) {
1004 		smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1005 			       ext->rt[i].rmb_key,
1006 			       ext->rt[i].rmb_vaddr_new,
1007 			       ext->rt[i].rmb_key_new);
1008 	}
1009 	up_write(&lgr->rmbs_lock);
1010 }
1011 
1012 static void smc_llc_save_add_link_info(struct smc_link *link,
1013 				       struct smc_llc_msg_add_link *add_llc)
1014 {
1015 	link->peer_qpn = ntoh24(add_llc->sender_qp_num);
1016 	memcpy(link->peer_gid, add_llc->sender_gid, SMC_GID_SIZE);
1017 	memcpy(link->peer_mac, add_llc->sender_mac, ETH_ALEN);
1018 	link->peer_psn = ntoh24(add_llc->initial_psn);
1019 	link->peer_mtu = add_llc->qp_mtu;
1020 }
1021 
1022 /* as an SMC client, process an add link request */
1023 int smc_llc_cli_add_link(struct smc_link *link, struct smc_llc_qentry *qentry)
1024 {
1025 	struct smc_llc_msg_add_link *llc = &qentry->msg.add_link;
1026 	enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1027 	struct smc_link_group *lgr = smc_get_lgr(link);
1028 	struct smc_init_info *ini = NULL;
1029 	struct smc_link *lnk_new = NULL;
1030 	int lnk_idx, rc = 0;
1031 
1032 	if (!llc->qp_mtu)
1033 		goto out_reject;
1034 
1035 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1036 	if (!ini) {
1037 		rc = -ENOMEM;
1038 		goto out_reject;
1039 	}
1040 
1041 	ini->vlan_id = lgr->vlan_id;
1042 	if (lgr->smc_version == SMC_V2) {
1043 		ini->check_smcrv2 = true;
1044 		ini->smcrv2.saddr = lgr->saddr;
1045 		ini->smcrv2.daddr = smc_ib_gid_to_ipv4(llc->sender_gid);
1046 	}
1047 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1048 	if (!memcmp(llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1049 	    (lgr->smc_version == SMC_V2 ||
1050 	     !memcmp(llc->sender_mac, link->peer_mac, ETH_ALEN))) {
1051 		if (!ini->ib_dev && !ini->smcrv2.ib_dev_v2)
1052 			goto out_reject;
1053 		lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1054 	}
1055 	if (lgr->smc_version == SMC_V2 && !ini->smcrv2.ib_dev_v2) {
1056 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1057 		ini->smcrv2.ib_dev_v2 = link->smcibdev;
1058 		ini->smcrv2.ib_port_v2 = link->ibport;
1059 	} else if (lgr->smc_version < SMC_V2 && !ini->ib_dev) {
1060 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1061 		ini->ib_dev = link->smcibdev;
1062 		ini->ib_port = link->ibport;
1063 	}
1064 	lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1065 	if (lnk_idx < 0)
1066 		goto out_reject;
1067 	lnk_new = &lgr->lnk[lnk_idx];
1068 	rc = smcr_link_init(lgr, lnk_new, lnk_idx, ini);
1069 	if (rc)
1070 		goto out_reject;
1071 	smc_llc_save_add_link_info(lnk_new, llc);
1072 	lnk_new->link_id = llc->link_num;	/* SMC server assigns link id */
1073 	smc_llc_link_set_uid(lnk_new);
1074 
1075 	rc = smc_ib_ready_link(lnk_new);
1076 	if (rc)
1077 		goto out_clear_lnk;
1078 
1079 	rc = smcr_buf_map_lgr(lnk_new);
1080 	if (rc)
1081 		goto out_clear_lnk;
1082 
1083 	rc = smc_llc_send_add_link(link,
1084 				   lnk_new->smcibdev->mac[lnk_new->ibport - 1],
1085 				   lnk_new->gid, lnk_new, SMC_LLC_RESP);
1086 	if (rc)
1087 		goto out_clear_lnk;
1088 	if (lgr->smc_version == SMC_V2) {
1089 		smc_llc_save_add_link_rkeys(link, lnk_new);
1090 	} else {
1091 		rc = smc_llc_cli_rkey_exchange(link, lnk_new);
1092 		if (rc) {
1093 			rc = 0;
1094 			goto out_clear_lnk;
1095 		}
1096 	}
1097 	rc = smc_llc_cli_conf_link(link, ini, lnk_new, lgr_new_t);
1098 	if (!rc)
1099 		goto out;
1100 out_clear_lnk:
1101 	lnk_new->state = SMC_LNK_INACTIVE;
1102 	smcr_link_clear(lnk_new, false);
1103 out_reject:
1104 	smc_llc_cli_add_link_reject(qentry);
1105 out:
1106 	kfree(ini);
1107 	kfree(qentry);
1108 	return rc;
1109 }
1110 
1111 static void smc_llc_send_request_add_link(struct smc_link *link)
1112 {
1113 	struct smc_llc_msg_req_add_link_v2 *llc;
1114 	struct smc_wr_tx_pend_priv *pend;
1115 	struct smc_wr_v2_buf *wr_buf;
1116 	struct smc_gidlist gidlist;
1117 	int rc, len, i;
1118 
1119 	if (!smc_wr_tx_link_hold(link))
1120 		return;
1121 	if (link->lgr->type == SMC_LGR_SYMMETRIC ||
1122 	    link->lgr->type == SMC_LGR_ASYMMETRIC_PEER)
1123 		goto put_out;
1124 
1125 	smc_fill_gid_list(link->lgr, &gidlist, link->smcibdev, link->gid);
1126 	if (gidlist.len <= 1)
1127 		goto put_out;
1128 
1129 	rc = smc_llc_add_pending_send_v2(link, &wr_buf, &pend);
1130 	if (rc)
1131 		goto put_out;
1132 	llc = (struct smc_llc_msg_req_add_link_v2 *)wr_buf;
1133 	memset(llc, 0, SMC_WR_TX_SIZE);
1134 
1135 	llc->hd.common.llc_type = SMC_LLC_REQ_ADD_LINK;
1136 	for (i = 0; i < gidlist.len; i++)
1137 		memcpy(llc->gid[i], gidlist.list[i], sizeof(gidlist.list[0]));
1138 	llc->gid_cnt = gidlist.len;
1139 	len = sizeof(*llc) + (gidlist.len * sizeof(gidlist.list[0]));
1140 	smc_llc_init_msg_hdr(&llc->hd, link->lgr, len);
1141 	rc = smc_wr_tx_v2_send(link, pend, len);
1142 	if (!rc)
1143 		/* set REQ_ADD_LINK flow and wait for response from peer */
1144 		link->lgr->llc_flow_lcl.type = SMC_LLC_FLOW_REQ_ADD_LINK;
1145 put_out:
1146 	smc_wr_tx_link_put(link);
1147 }
1148 
1149 /* as an SMC client, invite server to start the add_link processing */
1150 static void smc_llc_cli_add_link_invite(struct smc_link *link,
1151 					struct smc_llc_qentry *qentry)
1152 {
1153 	struct smc_link_group *lgr = smc_get_lgr(link);
1154 	struct smc_init_info *ini = NULL;
1155 
1156 	if (lgr->smc_version == SMC_V2) {
1157 		smc_llc_send_request_add_link(link);
1158 		goto out;
1159 	}
1160 
1161 	if (lgr->type == SMC_LGR_SYMMETRIC ||
1162 	    lgr->type == SMC_LGR_ASYMMETRIC_PEER)
1163 		goto out;
1164 
1165 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1166 	if (!ini)
1167 		goto out;
1168 
1169 	ini->vlan_id = lgr->vlan_id;
1170 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1171 	if (!ini->ib_dev)
1172 		goto out;
1173 
1174 	smc_llc_send_add_link(link, ini->ib_dev->mac[ini->ib_port - 1],
1175 			      ini->ib_gid, NULL, SMC_LLC_REQ);
1176 out:
1177 	kfree(ini);
1178 	kfree(qentry);
1179 }
1180 
1181 static bool smc_llc_is_empty_llc_message(union smc_llc_msg *llc)
1182 {
1183 	int i;
1184 
1185 	for (i = 0; i < ARRAY_SIZE(llc->raw.data); i++)
1186 		if (llc->raw.data[i])
1187 			return false;
1188 	return true;
1189 }
1190 
1191 static bool smc_llc_is_local_add_link(union smc_llc_msg *llc)
1192 {
1193 	if (llc->raw.hdr.common.llc_type == SMC_LLC_ADD_LINK &&
1194 	    smc_llc_is_empty_llc_message(llc))
1195 		return true;
1196 	return false;
1197 }
1198 
1199 static void smc_llc_process_cli_add_link(struct smc_link_group *lgr)
1200 {
1201 	struct smc_llc_qentry *qentry;
1202 
1203 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1204 
1205 	down_write(&lgr->llc_conf_mutex);
1206 	if (smc_llc_is_local_add_link(&qentry->msg))
1207 		smc_llc_cli_add_link_invite(qentry->link, qentry);
1208 	else
1209 		smc_llc_cli_add_link(qentry->link, qentry);
1210 	up_write(&lgr->llc_conf_mutex);
1211 }
1212 
1213 static int smc_llc_active_link_count(struct smc_link_group *lgr)
1214 {
1215 	int i, link_count = 0;
1216 
1217 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1218 		if (!smc_link_active(&lgr->lnk[i]))
1219 			continue;
1220 		link_count++;
1221 	}
1222 	return link_count;
1223 }
1224 
1225 /* find the asymmetric link when 3 links are established  */
1226 static struct smc_link *smc_llc_find_asym_link(struct smc_link_group *lgr)
1227 {
1228 	int asym_idx = -ENOENT;
1229 	int i, j, k;
1230 	bool found;
1231 
1232 	/* determine asymmetric link */
1233 	found = false;
1234 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1235 		for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
1236 			if (!smc_link_usable(&lgr->lnk[i]) ||
1237 			    !smc_link_usable(&lgr->lnk[j]))
1238 				continue;
1239 			if (!memcmp(lgr->lnk[i].gid, lgr->lnk[j].gid,
1240 				    SMC_GID_SIZE)) {
1241 				found = true;	/* asym_lnk is i or j */
1242 				break;
1243 			}
1244 		}
1245 		if (found)
1246 			break;
1247 	}
1248 	if (!found)
1249 		goto out; /* no asymmetric link */
1250 	for (k = 0; k < SMC_LINKS_PER_LGR_MAX; k++) {
1251 		if (!smc_link_usable(&lgr->lnk[k]))
1252 			continue;
1253 		if (k != i &&
1254 		    !memcmp(lgr->lnk[i].peer_gid, lgr->lnk[k].peer_gid,
1255 			    SMC_GID_SIZE)) {
1256 			asym_idx = i;
1257 			break;
1258 		}
1259 		if (k != j &&
1260 		    !memcmp(lgr->lnk[j].peer_gid, lgr->lnk[k].peer_gid,
1261 			    SMC_GID_SIZE)) {
1262 			asym_idx = j;
1263 			break;
1264 		}
1265 	}
1266 out:
1267 	return (asym_idx < 0) ? NULL : &lgr->lnk[asym_idx];
1268 }
1269 
1270 static void smc_llc_delete_asym_link(struct smc_link_group *lgr)
1271 {
1272 	struct smc_link *lnk_new = NULL, *lnk_asym;
1273 	struct smc_llc_qentry *qentry;
1274 	int rc;
1275 
1276 	lnk_asym = smc_llc_find_asym_link(lgr);
1277 	if (!lnk_asym)
1278 		return; /* no asymmetric link */
1279 	if (!smc_link_downing(&lnk_asym->state))
1280 		return;
1281 	lnk_new = smc_switch_conns(lgr, lnk_asym, false);
1282 	smc_wr_tx_wait_no_pending_sends(lnk_asym);
1283 	if (!lnk_new)
1284 		goto out_free;
1285 	/* change flow type from ADD_LINK into DEL_LINK */
1286 	lgr->llc_flow_lcl.type = SMC_LLC_FLOW_DEL_LINK;
1287 	rc = smc_llc_send_delete_link(lnk_new, lnk_asym->link_id, SMC_LLC_REQ,
1288 				      true, SMC_LLC_DEL_NO_ASYM_NEEDED);
1289 	if (rc) {
1290 		smcr_link_down_cond(lnk_new);
1291 		goto out_free;
1292 	}
1293 	qentry = smc_llc_wait(lgr, lnk_new, SMC_LLC_WAIT_TIME,
1294 			      SMC_LLC_DELETE_LINK);
1295 	if (!qentry) {
1296 		smcr_link_down_cond(lnk_new);
1297 		goto out_free;
1298 	}
1299 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1300 out_free:
1301 	smcr_link_clear(lnk_asym, true);
1302 }
1303 
1304 static int smc_llc_srv_rkey_exchange(struct smc_link *link,
1305 				     struct smc_link *link_new)
1306 {
1307 	struct smc_llc_msg_add_link_cont *addc_llc;
1308 	struct smc_link_group *lgr = link->lgr;
1309 	u8 max, num_rkeys_send, num_rkeys_recv;
1310 	struct smc_llc_qentry *qentry = NULL;
1311 	struct smc_buf_desc *buf_pos;
1312 	int buf_lst;
1313 	int rc = 0;
1314 	int i;
1315 
1316 	down_write(&lgr->rmbs_lock);
1317 	num_rkeys_send = lgr->conns_num;
1318 	buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
1319 	do {
1320 		smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
1321 				      &buf_lst, &buf_pos);
1322 		qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME,
1323 				      SMC_LLC_ADD_LINK_CONT);
1324 		if (!qentry) {
1325 			rc = -ETIMEDOUT;
1326 			goto out;
1327 		}
1328 		addc_llc = &qentry->msg.add_link_cont;
1329 		num_rkeys_recv = addc_llc->num_rkeys;
1330 		max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
1331 		for (i = 0; i < max; i++) {
1332 			smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1333 				       addc_llc->rt[i].rmb_key,
1334 				       addc_llc->rt[i].rmb_vaddr_new,
1335 				       addc_llc->rt[i].rmb_key_new);
1336 			num_rkeys_recv--;
1337 		}
1338 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1339 	} while (num_rkeys_send || num_rkeys_recv);
1340 out:
1341 	up_write(&lgr->rmbs_lock);
1342 	return rc;
1343 }
1344 
1345 static int smc_llc_srv_conf_link(struct smc_link *link,
1346 				 struct smc_link *link_new,
1347 				 enum smc_lgr_type lgr_new_t)
1348 {
1349 	struct smc_link_group *lgr = link->lgr;
1350 	struct smc_llc_qentry *qentry = NULL;
1351 	int rc;
1352 
1353 	/* send CONFIRM LINK request over the RoCE fabric */
1354 	rc = smc_llc_send_confirm_link(link_new, SMC_LLC_REQ);
1355 	if (rc)
1356 		return -ENOLINK;
1357 	/* receive CONFIRM LINK response over the RoCE fabric */
1358 	qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_FIRST_TIME, 0);
1359 	if (!qentry ||
1360 	    qentry->msg.raw.hdr.common.llc_type != SMC_LLC_CONFIRM_LINK) {
1361 		/* send DELETE LINK */
1362 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
1363 					 false, SMC_LLC_DEL_LOST_PATH);
1364 		if (qentry)
1365 			smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1366 		return -ENOLINK;
1367 	}
1368 	smc_llc_save_peer_uid(qentry);
1369 	smc_llc_link_active(link_new);
1370 	if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
1371 	    lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
1372 		smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
1373 	else
1374 		smcr_lgr_set_type(lgr, lgr_new_t);
1375 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1376 	return 0;
1377 }
1378 
1379 static void smc_llc_send_req_add_link_response(struct smc_llc_qentry *qentry)
1380 {
1381 	qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
1382 	smc_llc_init_msg_hdr(&qentry->msg.raw.hdr, qentry->link->lgr,
1383 			     sizeof(qentry->msg));
1384 	memset(&qentry->msg.raw.data, 0, sizeof(qentry->msg.raw.data));
1385 	smc_llc_send_message(qentry->link, &qentry->msg);
1386 }
1387 
1388 int smc_llc_srv_add_link(struct smc_link *link,
1389 			 struct smc_llc_qentry *req_qentry)
1390 {
1391 	enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1392 	struct smc_link_group *lgr = link->lgr;
1393 	struct smc_llc_msg_add_link *add_llc;
1394 	struct smc_llc_qentry *qentry = NULL;
1395 	bool send_req_add_link_resp = false;
1396 	struct smc_link *link_new = NULL;
1397 	struct smc_init_info *ini = NULL;
1398 	int lnk_idx, rc = 0;
1399 
1400 	if (req_qentry &&
1401 	    req_qentry->msg.raw.hdr.common.llc_type == SMC_LLC_REQ_ADD_LINK)
1402 		send_req_add_link_resp = true;
1403 
1404 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1405 	if (!ini) {
1406 		rc = -ENOMEM;
1407 		goto out;
1408 	}
1409 
1410 	/* ignore client add link recommendation, start new flow */
1411 	ini->vlan_id = lgr->vlan_id;
1412 	if (lgr->smc_version == SMC_V2) {
1413 		ini->check_smcrv2 = true;
1414 		ini->smcrv2.saddr = lgr->saddr;
1415 		if (send_req_add_link_resp) {
1416 			struct smc_llc_msg_req_add_link_v2 *req_add =
1417 				&req_qentry->msg.req_add_link;
1418 
1419 			ini->smcrv2.daddr = smc_ib_gid_to_ipv4(req_add->gid[0]);
1420 		}
1421 	}
1422 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1423 	if (lgr->smc_version == SMC_V2 && !ini->smcrv2.ib_dev_v2) {
1424 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1425 		ini->smcrv2.ib_dev_v2 = link->smcibdev;
1426 		ini->smcrv2.ib_port_v2 = link->ibport;
1427 	} else if (lgr->smc_version < SMC_V2 && !ini->ib_dev) {
1428 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1429 		ini->ib_dev = link->smcibdev;
1430 		ini->ib_port = link->ibport;
1431 	}
1432 	lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1433 	if (lnk_idx < 0) {
1434 		rc = 0;
1435 		goto out;
1436 	}
1437 
1438 	rc = smcr_link_init(lgr, &lgr->lnk[lnk_idx], lnk_idx, ini);
1439 	if (rc)
1440 		goto out;
1441 	link_new = &lgr->lnk[lnk_idx];
1442 
1443 	rc = smcr_buf_map_lgr(link_new);
1444 	if (rc)
1445 		goto out_err;
1446 
1447 	rc = smc_llc_send_add_link(link,
1448 				   link_new->smcibdev->mac[link_new->ibport-1],
1449 				   link_new->gid, link_new, SMC_LLC_REQ);
1450 	if (rc)
1451 		goto out_err;
1452 	send_req_add_link_resp = false;
1453 	/* receive ADD LINK response over the RoCE fabric */
1454 	qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME, SMC_LLC_ADD_LINK);
1455 	if (!qentry) {
1456 		rc = -ETIMEDOUT;
1457 		goto out_err;
1458 	}
1459 	add_llc = &qentry->msg.add_link;
1460 	if (add_llc->hd.flags & SMC_LLC_FLAG_ADD_LNK_REJ) {
1461 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1462 		rc = -ENOLINK;
1463 		goto out_err;
1464 	}
1465 	if (lgr->type == SMC_LGR_SINGLE &&
1466 	    (!memcmp(add_llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1467 	     (lgr->smc_version == SMC_V2 ||
1468 	      !memcmp(add_llc->sender_mac, link->peer_mac, ETH_ALEN)))) {
1469 		lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1470 	}
1471 	smc_llc_save_add_link_info(link_new, add_llc);
1472 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1473 
1474 	rc = smc_ib_ready_link(link_new);
1475 	if (rc)
1476 		goto out_err;
1477 	rc = smcr_buf_reg_lgr(link_new);
1478 	if (rc)
1479 		goto out_err;
1480 	if (lgr->smc_version == SMC_V2) {
1481 		smc_llc_save_add_link_rkeys(link, link_new);
1482 	} else {
1483 		rc = smc_llc_srv_rkey_exchange(link, link_new);
1484 		if (rc)
1485 			goto out_err;
1486 	}
1487 	rc = smc_llc_srv_conf_link(link, link_new, lgr_new_t);
1488 	if (rc)
1489 		goto out_err;
1490 	kfree(ini);
1491 	return 0;
1492 out_err:
1493 	if (link_new) {
1494 		link_new->state = SMC_LNK_INACTIVE;
1495 		smcr_link_clear(link_new, false);
1496 	}
1497 out:
1498 	kfree(ini);
1499 	if (send_req_add_link_resp)
1500 		smc_llc_send_req_add_link_response(req_qentry);
1501 	return rc;
1502 }
1503 
1504 static void smc_llc_process_srv_add_link(struct smc_link_group *lgr)
1505 {
1506 	struct smc_link *link = lgr->llc_flow_lcl.qentry->link;
1507 	struct smc_llc_qentry *qentry;
1508 	int rc;
1509 
1510 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1511 
1512 	down_write(&lgr->llc_conf_mutex);
1513 	rc = smc_llc_srv_add_link(link, qentry);
1514 	if (!rc && lgr->type == SMC_LGR_SYMMETRIC) {
1515 		/* delete any asymmetric link */
1516 		smc_llc_delete_asym_link(lgr);
1517 	}
1518 	up_write(&lgr->llc_conf_mutex);
1519 	kfree(qentry);
1520 }
1521 
1522 /* enqueue a local add_link req to trigger a new add_link flow */
1523 void smc_llc_add_link_local(struct smc_link *link)
1524 {
1525 	struct smc_llc_msg_add_link add_llc = {};
1526 
1527 	add_llc.hd.common.llc_type = SMC_LLC_ADD_LINK;
1528 	smc_llc_init_msg_hdr(&add_llc.hd, link->lgr, sizeof(add_llc));
1529 	/* no dev and port needed */
1530 	smc_llc_enqueue(link, (union smc_llc_msg *)&add_llc);
1531 }
1532 
1533 /* worker to process an add link message */
1534 static void smc_llc_add_link_work(struct work_struct *work)
1535 {
1536 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1537 						  llc_add_link_work);
1538 
1539 	if (list_empty(&lgr->list)) {
1540 		/* link group is terminating */
1541 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1542 		goto out;
1543 	}
1544 
1545 	if (lgr->role == SMC_CLNT)
1546 		smc_llc_process_cli_add_link(lgr);
1547 	else
1548 		smc_llc_process_srv_add_link(lgr);
1549 out:
1550 	if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_REQ_ADD_LINK)
1551 		smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1552 }
1553 
1554 /* enqueue a local del_link msg to trigger a new del_link flow,
1555  * called only for role SMC_SERV
1556  */
1557 void smc_llc_srv_delete_link_local(struct smc_link *link, u8 del_link_id)
1558 {
1559 	struct smc_llc_msg_del_link del_llc = {};
1560 
1561 	del_llc.hd.common.llc_type = SMC_LLC_DELETE_LINK;
1562 	smc_llc_init_msg_hdr(&del_llc.hd, link->lgr, sizeof(del_llc));
1563 	del_llc.link_num = del_link_id;
1564 	del_llc.reason = htonl(SMC_LLC_DEL_LOST_PATH);
1565 	del_llc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1566 	smc_llc_enqueue(link, (union smc_llc_msg *)&del_llc);
1567 }
1568 
1569 static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
1570 {
1571 	struct smc_link *lnk_del = NULL, *lnk_asym, *lnk;
1572 	struct smc_llc_msg_del_link *del_llc;
1573 	struct smc_llc_qentry *qentry;
1574 	int active_links;
1575 	int lnk_idx;
1576 
1577 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1578 	lnk = qentry->link;
1579 	del_llc = &qentry->msg.delete_link;
1580 
1581 	if (del_llc->hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1582 		smc_lgr_terminate_sched(lgr);
1583 		goto out;
1584 	}
1585 	down_write(&lgr->llc_conf_mutex);
1586 	/* delete single link */
1587 	for (lnk_idx = 0; lnk_idx < SMC_LINKS_PER_LGR_MAX; lnk_idx++) {
1588 		if (lgr->lnk[lnk_idx].link_id != del_llc->link_num)
1589 			continue;
1590 		lnk_del = &lgr->lnk[lnk_idx];
1591 		break;
1592 	}
1593 	del_llc->hd.flags |= SMC_LLC_FLAG_RESP;
1594 	if (!lnk_del) {
1595 		/* link was not found */
1596 		del_llc->reason = htonl(SMC_LLC_DEL_NOLNK);
1597 		smc_llc_send_message(lnk, &qentry->msg);
1598 		goto out_unlock;
1599 	}
1600 	lnk_asym = smc_llc_find_asym_link(lgr);
1601 
1602 	del_llc->reason = 0;
1603 	smc_llc_send_message(lnk, &qentry->msg); /* response */
1604 
1605 	if (smc_link_downing(&lnk_del->state))
1606 		smc_switch_conns(lgr, lnk_del, false);
1607 	smcr_link_clear(lnk_del, true);
1608 
1609 	active_links = smc_llc_active_link_count(lgr);
1610 	if (lnk_del == lnk_asym) {
1611 		/* expected deletion of asym link, don't change lgr state */
1612 	} else if (active_links == 1) {
1613 		smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1614 	} else if (!active_links) {
1615 		smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1616 		smc_lgr_terminate_sched(lgr);
1617 	}
1618 out_unlock:
1619 	up_write(&lgr->llc_conf_mutex);
1620 out:
1621 	kfree(qentry);
1622 }
1623 
1624 /* try to send a DELETE LINK ALL request on any active link,
1625  * waiting for send completion
1626  */
1627 void smc_llc_send_link_delete_all(struct smc_link_group *lgr, bool ord, u32 rsn)
1628 {
1629 	struct smc_llc_msg_del_link delllc = {};
1630 	int i;
1631 
1632 	delllc.hd.common.llc_type = SMC_LLC_DELETE_LINK;
1633 	smc_llc_init_msg_hdr(&delllc.hd, lgr, sizeof(delllc));
1634 	if (ord)
1635 		delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1636 	delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
1637 	delllc.reason = htonl(rsn);
1638 
1639 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1640 		if (!smc_link_sendable(&lgr->lnk[i]))
1641 			continue;
1642 		if (!smc_llc_send_message_wait(&lgr->lnk[i], &delllc))
1643 			break;
1644 	}
1645 }
1646 
1647 static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr)
1648 {
1649 	struct smc_llc_msg_del_link *del_llc;
1650 	struct smc_link *lnk, *lnk_del;
1651 	struct smc_llc_qentry *qentry;
1652 	int active_links;
1653 	int i;
1654 
1655 	down_write(&lgr->llc_conf_mutex);
1656 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1657 	lnk = qentry->link;
1658 	del_llc = &qentry->msg.delete_link;
1659 
1660 	if (qentry->msg.delete_link.hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1661 		/* delete entire lgr */
1662 		smc_llc_send_link_delete_all(lgr, true, ntohl(
1663 					      qentry->msg.delete_link.reason));
1664 		smc_lgr_terminate_sched(lgr);
1665 		goto out;
1666 	}
1667 	/* delete single link */
1668 	lnk_del = NULL;
1669 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1670 		if (lgr->lnk[i].link_id == del_llc->link_num) {
1671 			lnk_del = &lgr->lnk[i];
1672 			break;
1673 		}
1674 	}
1675 	if (!lnk_del)
1676 		goto out; /* asymmetric link already deleted */
1677 
1678 	if (smc_link_downing(&lnk_del->state)) {
1679 		if (smc_switch_conns(lgr, lnk_del, false))
1680 			smc_wr_tx_wait_no_pending_sends(lnk_del);
1681 	}
1682 	if (!list_empty(&lgr->list)) {
1683 		/* qentry is either a request from peer (send it back to
1684 		 * initiate the DELETE_LINK processing), or a locally
1685 		 * enqueued DELETE_LINK request (forward it)
1686 		 */
1687 		if (!smc_llc_send_message(lnk, &qentry->msg)) {
1688 			struct smc_llc_qentry *qentry2;
1689 
1690 			qentry2 = smc_llc_wait(lgr, lnk, SMC_LLC_WAIT_TIME,
1691 					       SMC_LLC_DELETE_LINK);
1692 			if (qentry2)
1693 				smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1694 		}
1695 	}
1696 	smcr_link_clear(lnk_del, true);
1697 
1698 	active_links = smc_llc_active_link_count(lgr);
1699 	if (active_links == 1) {
1700 		smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1701 	} else if (!active_links) {
1702 		smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1703 		smc_lgr_terminate_sched(lgr);
1704 	}
1705 
1706 	if (lgr->type == SMC_LGR_SINGLE && !list_empty(&lgr->list)) {
1707 		/* trigger setup of asymm alt link */
1708 		smc_llc_add_link_local(lnk);
1709 	}
1710 out:
1711 	up_write(&lgr->llc_conf_mutex);
1712 	kfree(qentry);
1713 }
1714 
1715 static void smc_llc_delete_link_work(struct work_struct *work)
1716 {
1717 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1718 						  llc_del_link_work);
1719 
1720 	if (list_empty(&lgr->list)) {
1721 		/* link group is terminating */
1722 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1723 		goto out;
1724 	}
1725 
1726 	if (lgr->role == SMC_CLNT)
1727 		smc_llc_process_cli_delete_link(lgr);
1728 	else
1729 		smc_llc_process_srv_delete_link(lgr);
1730 out:
1731 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1732 }
1733 
1734 /* process a confirm_rkey request from peer, remote flow */
1735 static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr)
1736 {
1737 	struct smc_llc_msg_confirm_rkey *llc;
1738 	struct smc_llc_qentry *qentry;
1739 	struct smc_link *link;
1740 	int num_entries;
1741 	int rk_idx;
1742 	int i;
1743 
1744 	qentry = lgr->llc_flow_rmt.qentry;
1745 	llc = &qentry->msg.confirm_rkey;
1746 	link = qentry->link;
1747 
1748 	num_entries = llc->rtoken[0].num_rkeys;
1749 	if (num_entries > SMC_LLC_RKEYS_PER_MSG)
1750 		goto out_err;
1751 	/* first rkey entry is for receiving link */
1752 	rk_idx = smc_rtoken_add(link,
1753 				llc->rtoken[0].rmb_vaddr,
1754 				llc->rtoken[0].rmb_key);
1755 	if (rk_idx < 0)
1756 		goto out_err;
1757 
1758 	for (i = 1; i <= min_t(u8, num_entries, SMC_LLC_RKEYS_PER_MSG - 1); i++)
1759 		smc_rtoken_set2(lgr, rk_idx, llc->rtoken[i].link_id,
1760 				llc->rtoken[i].rmb_vaddr,
1761 				llc->rtoken[i].rmb_key);
1762 	/* max links is 3 so there is no need to support conf_rkey_cont msgs */
1763 	goto out;
1764 out_err:
1765 	llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1766 	llc->hd.flags |= SMC_LLC_FLAG_RKEY_RETRY;
1767 out:
1768 	llc->hd.flags |= SMC_LLC_FLAG_RESP;
1769 	smc_llc_init_msg_hdr(&llc->hd, link->lgr, sizeof(*llc));
1770 	smc_llc_send_message(link, &qentry->msg);
1771 	smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1772 }
1773 
1774 /* process a delete_rkey request from peer, remote flow */
1775 static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr)
1776 {
1777 	struct smc_llc_msg_delete_rkey *llc;
1778 	struct smc_llc_qentry *qentry;
1779 	struct smc_link *link;
1780 	u8 err_mask = 0;
1781 	int i, max;
1782 
1783 	qentry = lgr->llc_flow_rmt.qentry;
1784 	llc = &qentry->msg.delete_rkey;
1785 	link = qentry->link;
1786 
1787 	if (lgr->smc_version == SMC_V2) {
1788 		struct smc_llc_msg_delete_rkey_v2 *llcv2;
1789 
1790 		memcpy(lgr->wr_rx_buf_v2, llc, sizeof(*llc));
1791 		llcv2 = (struct smc_llc_msg_delete_rkey_v2 *)lgr->wr_rx_buf_v2;
1792 		llcv2->num_inval_rkeys = 0;
1793 
1794 		max = min_t(u8, llcv2->num_rkeys, SMC_LLC_RKEYS_PER_MSG_V2);
1795 		for (i = 0; i < max; i++) {
1796 			if (smc_rtoken_delete(link, llcv2->rkey[i]))
1797 				llcv2->num_inval_rkeys++;
1798 		}
1799 		memset(&llc->rkey[0], 0, sizeof(llc->rkey));
1800 		memset(&llc->reserved2, 0, sizeof(llc->reserved2));
1801 		smc_llc_init_msg_hdr(&llc->hd, link->lgr, sizeof(*llc));
1802 		if (llcv2->num_inval_rkeys) {
1803 			llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1804 			llc->err_mask = llcv2->num_inval_rkeys;
1805 		}
1806 		goto finish;
1807 	}
1808 
1809 	max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
1810 	for (i = 0; i < max; i++) {
1811 		if (smc_rtoken_delete(link, llc->rkey[i]))
1812 			err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
1813 	}
1814 	if (err_mask) {
1815 		llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1816 		llc->err_mask = err_mask;
1817 	}
1818 finish:
1819 	llc->hd.flags |= SMC_LLC_FLAG_RESP;
1820 	smc_llc_send_message(link, &qentry->msg);
1821 	smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1822 }
1823 
1824 static void smc_llc_protocol_violation(struct smc_link_group *lgr, u8 type)
1825 {
1826 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu LLC protocol violation: "
1827 			    "llc_type %d\n", SMC_LGR_ID_SIZE, &lgr->id,
1828 			    lgr->net->net_cookie, type);
1829 	smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_PROT_VIOL);
1830 	smc_lgr_terminate_sched(lgr);
1831 }
1832 
1833 /* flush the llc event queue */
1834 static void smc_llc_event_flush(struct smc_link_group *lgr)
1835 {
1836 	struct smc_llc_qentry *qentry, *q;
1837 
1838 	spin_lock_bh(&lgr->llc_event_q_lock);
1839 	list_for_each_entry_safe(qentry, q, &lgr->llc_event_q, list) {
1840 		list_del_init(&qentry->list);
1841 		kfree(qentry);
1842 	}
1843 	spin_unlock_bh(&lgr->llc_event_q_lock);
1844 }
1845 
1846 static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
1847 {
1848 	union smc_llc_msg *llc = &qentry->msg;
1849 	struct smc_link *link = qentry->link;
1850 	struct smc_link_group *lgr = link->lgr;
1851 
1852 	if (!smc_link_usable(link))
1853 		goto out;
1854 
1855 	switch (llc->raw.hdr.common.llc_type) {
1856 	case SMC_LLC_TEST_LINK:
1857 		llc->test_link.hd.flags |= SMC_LLC_FLAG_RESP;
1858 		smc_llc_send_message(link, llc);
1859 		break;
1860 	case SMC_LLC_ADD_LINK:
1861 		if (list_empty(&lgr->list))
1862 			goto out;	/* lgr is terminating */
1863 		if (lgr->role == SMC_CLNT) {
1864 			if (smc_llc_is_local_add_link(llc)) {
1865 				if (lgr->llc_flow_lcl.type ==
1866 				    SMC_LLC_FLOW_ADD_LINK)
1867 					break;	/* add_link in progress */
1868 				if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1869 						       qentry)) {
1870 					schedule_work(&lgr->llc_add_link_work);
1871 				}
1872 				return;
1873 			}
1874 			if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1875 			    !lgr->llc_flow_lcl.qentry) {
1876 				/* a flow is waiting for this message */
1877 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1878 							qentry);
1879 				wake_up(&lgr->llc_msg_waiter);
1880 				return;
1881 			}
1882 			if (lgr->llc_flow_lcl.type ==
1883 					SMC_LLC_FLOW_REQ_ADD_LINK) {
1884 				/* server started add_link processing */
1885 				lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK;
1886 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1887 							qentry);
1888 				schedule_work(&lgr->llc_add_link_work);
1889 				return;
1890 			}
1891 			if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1892 				schedule_work(&lgr->llc_add_link_work);
1893 			}
1894 		} else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1895 			/* as smc server, handle client suggestion */
1896 			schedule_work(&lgr->llc_add_link_work);
1897 		}
1898 		return;
1899 	case SMC_LLC_CONFIRM_LINK:
1900 	case SMC_LLC_ADD_LINK_CONT:
1901 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1902 			/* a flow is waiting for this message */
1903 			smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1904 			wake_up(&lgr->llc_msg_waiter);
1905 			return;
1906 		}
1907 		break;
1908 	case SMC_LLC_DELETE_LINK:
1909 		if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1910 		    !lgr->llc_flow_lcl.qentry) {
1911 			/* DEL LINK REQ during ADD LINK SEQ */
1912 			smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1913 			wake_up(&lgr->llc_msg_waiter);
1914 		} else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1915 			schedule_work(&lgr->llc_del_link_work);
1916 		}
1917 		return;
1918 	case SMC_LLC_CONFIRM_RKEY:
1919 		/* new request from remote, assign to remote flow */
1920 		if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1921 			/* process here, does not wait for more llc msgs */
1922 			smc_llc_rmt_conf_rkey(lgr);
1923 			smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1924 		}
1925 		return;
1926 	case SMC_LLC_CONFIRM_RKEY_CONT:
1927 		/* not used because max links is 3, and 3 rkeys fit into
1928 		 * one CONFIRM_RKEY message
1929 		 */
1930 		break;
1931 	case SMC_LLC_DELETE_RKEY:
1932 		/* new request from remote, assign to remote flow */
1933 		if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1934 			/* process here, does not wait for more llc msgs */
1935 			smc_llc_rmt_delete_rkey(lgr);
1936 			smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1937 		}
1938 		return;
1939 	case SMC_LLC_REQ_ADD_LINK:
1940 		/* handle response here, smc_llc_flow_stop() cannot be called
1941 		 * in tasklet context
1942 		 */
1943 		if (lgr->role == SMC_CLNT &&
1944 		    lgr->llc_flow_lcl.type == SMC_LLC_FLOW_REQ_ADD_LINK &&
1945 		    (llc->raw.hdr.flags & SMC_LLC_FLAG_RESP)) {
1946 			smc_llc_flow_stop(link->lgr, &lgr->llc_flow_lcl);
1947 		} else if (lgr->role == SMC_SERV) {
1948 			if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1949 				/* as smc server, handle client suggestion */
1950 				lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK;
1951 				schedule_work(&lgr->llc_add_link_work);
1952 			}
1953 			return;
1954 		}
1955 		break;
1956 	default:
1957 		smc_llc_protocol_violation(lgr, llc->raw.hdr.common.type);
1958 		break;
1959 	}
1960 out:
1961 	kfree(qentry);
1962 }
1963 
1964 /* worker to process llc messages on the event queue */
1965 static void smc_llc_event_work(struct work_struct *work)
1966 {
1967 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1968 						  llc_event_work);
1969 	struct smc_llc_qentry *qentry;
1970 
1971 	if (!lgr->llc_flow_lcl.type && lgr->delayed_event) {
1972 		qentry = lgr->delayed_event;
1973 		lgr->delayed_event = NULL;
1974 		if (smc_link_usable(qentry->link))
1975 			smc_llc_event_handler(qentry);
1976 		else
1977 			kfree(qentry);
1978 	}
1979 
1980 again:
1981 	spin_lock_bh(&lgr->llc_event_q_lock);
1982 	if (!list_empty(&lgr->llc_event_q)) {
1983 		qentry = list_first_entry(&lgr->llc_event_q,
1984 					  struct smc_llc_qentry, list);
1985 		list_del_init(&qentry->list);
1986 		spin_unlock_bh(&lgr->llc_event_q_lock);
1987 		smc_llc_event_handler(qentry);
1988 		goto again;
1989 	}
1990 	spin_unlock_bh(&lgr->llc_event_q_lock);
1991 }
1992 
1993 /* process llc responses in tasklet context */
1994 static void smc_llc_rx_response(struct smc_link *link,
1995 				struct smc_llc_qentry *qentry)
1996 {
1997 	enum smc_llc_flowtype flowtype = link->lgr->llc_flow_lcl.type;
1998 	struct smc_llc_flow *flow = &link->lgr->llc_flow_lcl;
1999 	u8 llc_type = qentry->msg.raw.hdr.common.llc_type;
2000 
2001 	switch (llc_type) {
2002 	case SMC_LLC_TEST_LINK:
2003 		if (smc_link_active(link))
2004 			complete(&link->llc_testlink_resp);
2005 		break;
2006 	case SMC_LLC_ADD_LINK:
2007 	case SMC_LLC_ADD_LINK_CONT:
2008 	case SMC_LLC_CONFIRM_LINK:
2009 		if (flowtype != SMC_LLC_FLOW_ADD_LINK || flow->qentry)
2010 			break;	/* drop out-of-flow response */
2011 		goto assign;
2012 	case SMC_LLC_DELETE_LINK:
2013 		if (flowtype != SMC_LLC_FLOW_DEL_LINK || flow->qentry)
2014 			break;	/* drop out-of-flow response */
2015 		goto assign;
2016 	case SMC_LLC_CONFIRM_RKEY:
2017 	case SMC_LLC_DELETE_RKEY:
2018 		if (flowtype != SMC_LLC_FLOW_RKEY || flow->qentry)
2019 			break;	/* drop out-of-flow response */
2020 		goto assign;
2021 	case SMC_LLC_CONFIRM_RKEY_CONT:
2022 		/* not used because max links is 3 */
2023 		break;
2024 	default:
2025 		smc_llc_protocol_violation(link->lgr,
2026 					   qentry->msg.raw.hdr.common.type);
2027 		break;
2028 	}
2029 	kfree(qentry);
2030 	return;
2031 assign:
2032 	/* assign responses to the local flow, we requested them */
2033 	smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
2034 	wake_up(&link->lgr->llc_msg_waiter);
2035 }
2036 
2037 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc)
2038 {
2039 	struct smc_link_group *lgr = link->lgr;
2040 	struct smc_llc_qentry *qentry;
2041 	unsigned long flags;
2042 
2043 	qentry = kmalloc(sizeof(*qentry), GFP_ATOMIC);
2044 	if (!qentry)
2045 		return;
2046 	qentry->link = link;
2047 	INIT_LIST_HEAD(&qentry->list);
2048 	memcpy(&qentry->msg, llc, sizeof(union smc_llc_msg));
2049 
2050 	/* process responses immediately */
2051 	if ((llc->raw.hdr.flags & SMC_LLC_FLAG_RESP) &&
2052 	    llc->raw.hdr.common.llc_type != SMC_LLC_REQ_ADD_LINK) {
2053 		smc_llc_rx_response(link, qentry);
2054 		return;
2055 	}
2056 
2057 	/* add requests to event queue */
2058 	spin_lock_irqsave(&lgr->llc_event_q_lock, flags);
2059 	list_add_tail(&qentry->list, &lgr->llc_event_q);
2060 	spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags);
2061 	queue_work(system_highpri_wq, &lgr->llc_event_work);
2062 }
2063 
2064 /* copy received msg and add it to the event queue */
2065 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
2066 {
2067 	struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
2068 	union smc_llc_msg *llc = buf;
2069 
2070 	if (wc->byte_len < sizeof(*llc))
2071 		return; /* short message */
2072 	if (!llc->raw.hdr.common.llc_version) {
2073 		if (llc->raw.hdr.length != sizeof(*llc))
2074 			return; /* invalid message */
2075 	} else {
2076 		if (llc->raw.hdr.length_v2 < sizeof(*llc))
2077 			return; /* invalid message */
2078 	}
2079 
2080 	smc_llc_enqueue(link, llc);
2081 }
2082 
2083 /***************************** worker, utils *********************************/
2084 
2085 static void smc_llc_testlink_work(struct work_struct *work)
2086 {
2087 	struct smc_link *link = container_of(to_delayed_work(work),
2088 					     struct smc_link, llc_testlink_wrk);
2089 	unsigned long next_interval;
2090 	unsigned long expire_time;
2091 	u8 user_data[16] = { 0 };
2092 	int rc;
2093 
2094 	if (!smc_link_active(link))
2095 		return;		/* don't reschedule worker */
2096 	expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
2097 	if (time_is_after_jiffies(expire_time)) {
2098 		next_interval = expire_time - jiffies;
2099 		goto out;
2100 	}
2101 	reinit_completion(&link->llc_testlink_resp);
2102 	smc_llc_send_test_link(link, user_data);
2103 	/* receive TEST LINK response over RoCE fabric */
2104 	rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
2105 						       SMC_LLC_WAIT_TIME);
2106 	if (!smc_link_active(link))
2107 		return;		/* link state changed */
2108 	if (rc <= 0) {
2109 		smcr_link_down_cond_sched(link);
2110 		return;
2111 	}
2112 	next_interval = link->llc_testlink_time;
2113 out:
2114 	schedule_delayed_work(&link->llc_testlink_wrk, next_interval);
2115 }
2116 
2117 void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
2118 {
2119 	struct net *net = sock_net(smc->clcsock->sk);
2120 
2121 	INIT_WORK(&lgr->llc_event_work, smc_llc_event_work);
2122 	INIT_WORK(&lgr->llc_add_link_work, smc_llc_add_link_work);
2123 	INIT_WORK(&lgr->llc_del_link_work, smc_llc_delete_link_work);
2124 	INIT_LIST_HEAD(&lgr->llc_event_q);
2125 	spin_lock_init(&lgr->llc_event_q_lock);
2126 	spin_lock_init(&lgr->llc_flow_lock);
2127 	init_waitqueue_head(&lgr->llc_flow_waiter);
2128 	init_waitqueue_head(&lgr->llc_msg_waiter);
2129 	init_rwsem(&lgr->llc_conf_mutex);
2130 	lgr->llc_testlink_time = READ_ONCE(net->smc.sysctl_smcr_testlink_time);
2131 }
2132 
2133 /* called after lgr was removed from lgr_list */
2134 void smc_llc_lgr_clear(struct smc_link_group *lgr)
2135 {
2136 	smc_llc_event_flush(lgr);
2137 	wake_up_all(&lgr->llc_flow_waiter);
2138 	wake_up_all(&lgr->llc_msg_waiter);
2139 	cancel_work_sync(&lgr->llc_event_work);
2140 	cancel_work_sync(&lgr->llc_add_link_work);
2141 	cancel_work_sync(&lgr->llc_del_link_work);
2142 	if (lgr->delayed_event) {
2143 		kfree(lgr->delayed_event);
2144 		lgr->delayed_event = NULL;
2145 	}
2146 }
2147 
2148 int smc_llc_link_init(struct smc_link *link)
2149 {
2150 	init_completion(&link->llc_testlink_resp);
2151 	INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
2152 	return 0;
2153 }
2154 
2155 void smc_llc_link_active(struct smc_link *link)
2156 {
2157 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu link added: id %*phN, "
2158 			    "peerid %*phN, ibdev %s, ibport %d\n",
2159 			    SMC_LGR_ID_SIZE, &link->lgr->id,
2160 			    link->lgr->net->net_cookie,
2161 			    SMC_LGR_ID_SIZE, &link->link_uid,
2162 			    SMC_LGR_ID_SIZE, &link->peer_link_uid,
2163 			    link->smcibdev->ibdev->name, link->ibport);
2164 	link->state = SMC_LNK_ACTIVE;
2165 	if (link->lgr->llc_testlink_time) {
2166 		link->llc_testlink_time = link->lgr->llc_testlink_time;
2167 		schedule_delayed_work(&link->llc_testlink_wrk,
2168 				      link->llc_testlink_time);
2169 	}
2170 }
2171 
2172 /* called in worker context */
2173 void smc_llc_link_clear(struct smc_link *link, bool log)
2174 {
2175 	if (log)
2176 		pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu link removed: id %*phN"
2177 				    ", peerid %*phN, ibdev %s, ibport %d\n",
2178 				    SMC_LGR_ID_SIZE, &link->lgr->id,
2179 				    link->lgr->net->net_cookie,
2180 				    SMC_LGR_ID_SIZE, &link->link_uid,
2181 				    SMC_LGR_ID_SIZE, &link->peer_link_uid,
2182 				    link->smcibdev->ibdev->name, link->ibport);
2183 	complete(&link->llc_testlink_resp);
2184 	cancel_delayed_work_sync(&link->llc_testlink_wrk);
2185 }
2186 
2187 /* register a new rtoken at the remote peer (for all links) */
2188 int smc_llc_do_confirm_rkey(struct smc_link *send_link,
2189 			    struct smc_buf_desc *rmb_desc)
2190 {
2191 	struct smc_link_group *lgr = send_link->lgr;
2192 	struct smc_llc_qentry *qentry = NULL;
2193 	int rc = 0;
2194 
2195 	rc = smc_llc_send_confirm_rkey(send_link, rmb_desc);
2196 	if (rc)
2197 		goto out;
2198 	/* receive CONFIRM RKEY response from server over RoCE fabric */
2199 	qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
2200 			      SMC_LLC_CONFIRM_RKEY);
2201 	if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
2202 		rc = -EFAULT;
2203 out:
2204 	if (qentry)
2205 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
2206 	return rc;
2207 }
2208 
2209 /* unregister an rtoken at the remote peer */
2210 int smc_llc_do_delete_rkey(struct smc_link_group *lgr,
2211 			   struct smc_buf_desc *rmb_desc)
2212 {
2213 	struct smc_llc_qentry *qentry = NULL;
2214 	struct smc_link *send_link;
2215 	int rc = 0;
2216 
2217 	send_link = smc_llc_usable_link(lgr);
2218 	if (!send_link)
2219 		return -ENOLINK;
2220 
2221 	/* protected by llc_flow control */
2222 	rc = smc_llc_send_delete_rkey(send_link, rmb_desc);
2223 	if (rc)
2224 		goto out;
2225 	/* receive DELETE RKEY response from server over RoCE fabric */
2226 	qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
2227 			      SMC_LLC_DELETE_RKEY);
2228 	if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
2229 		rc = -EFAULT;
2230 out:
2231 	if (qentry)
2232 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
2233 	return rc;
2234 }
2235 
2236 void smc_llc_link_set_uid(struct smc_link *link)
2237 {
2238 	__be32 link_uid;
2239 
2240 	link_uid = htonl(*((u32 *)link->lgr->id) + link->link_id);
2241 	memcpy(link->link_uid, &link_uid, SMC_LGR_ID_SIZE);
2242 }
2243 
2244 /* save peers link user id, used for debug purposes */
2245 void smc_llc_save_peer_uid(struct smc_llc_qentry *qentry)
2246 {
2247 	memcpy(qentry->link->peer_link_uid, qentry->msg.confirm_link.link_uid,
2248 	       SMC_LGR_ID_SIZE);
2249 }
2250 
2251 /* evaluate confirm link request or response */
2252 int smc_llc_eval_conf_link(struct smc_llc_qentry *qentry,
2253 			   enum smc_llc_reqresp type)
2254 {
2255 	if (type == SMC_LLC_REQ) {	/* SMC server assigns link_id */
2256 		qentry->link->link_id = qentry->msg.confirm_link.link_num;
2257 		smc_llc_link_set_uid(qentry->link);
2258 	}
2259 	if (!(qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_NO_RMBE_EYEC))
2260 		return -ENOTSUPP;
2261 	return 0;
2262 }
2263 
2264 /***************************** init, exit, misc ******************************/
2265 
2266 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
2267 	{
2268 		.handler	= smc_llc_rx_handler,
2269 		.type		= SMC_LLC_CONFIRM_LINK
2270 	},
2271 	{
2272 		.handler	= smc_llc_rx_handler,
2273 		.type		= SMC_LLC_TEST_LINK
2274 	},
2275 	{
2276 		.handler	= smc_llc_rx_handler,
2277 		.type		= SMC_LLC_ADD_LINK
2278 	},
2279 	{
2280 		.handler	= smc_llc_rx_handler,
2281 		.type		= SMC_LLC_ADD_LINK_CONT
2282 	},
2283 	{
2284 		.handler	= smc_llc_rx_handler,
2285 		.type		= SMC_LLC_DELETE_LINK
2286 	},
2287 	{
2288 		.handler	= smc_llc_rx_handler,
2289 		.type		= SMC_LLC_CONFIRM_RKEY
2290 	},
2291 	{
2292 		.handler	= smc_llc_rx_handler,
2293 		.type		= SMC_LLC_CONFIRM_RKEY_CONT
2294 	},
2295 	{
2296 		.handler	= smc_llc_rx_handler,
2297 		.type		= SMC_LLC_DELETE_RKEY
2298 	},
2299 	/* V2 types */
2300 	{
2301 		.handler	= smc_llc_rx_handler,
2302 		.type		= SMC_LLC_CONFIRM_LINK_V2
2303 	},
2304 	{
2305 		.handler	= smc_llc_rx_handler,
2306 		.type		= SMC_LLC_TEST_LINK_V2
2307 	},
2308 	{
2309 		.handler	= smc_llc_rx_handler,
2310 		.type		= SMC_LLC_ADD_LINK_V2
2311 	},
2312 	{
2313 		.handler	= smc_llc_rx_handler,
2314 		.type		= SMC_LLC_DELETE_LINK_V2
2315 	},
2316 	{
2317 		.handler	= smc_llc_rx_handler,
2318 		.type		= SMC_LLC_REQ_ADD_LINK_V2
2319 	},
2320 	{
2321 		.handler	= smc_llc_rx_handler,
2322 		.type		= SMC_LLC_CONFIRM_RKEY_V2
2323 	},
2324 	{
2325 		.handler	= smc_llc_rx_handler,
2326 		.type		= SMC_LLC_DELETE_RKEY_V2
2327 	},
2328 	{
2329 		.handler	= NULL,
2330 	}
2331 };
2332 
2333 int __init smc_llc_init(void)
2334 {
2335 	struct smc_wr_rx_handler *handler;
2336 	int rc = 0;
2337 
2338 	for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
2339 		INIT_HLIST_NODE(&handler->list);
2340 		rc = smc_wr_rx_register_handler(handler);
2341 		if (rc)
2342 			break;
2343 	}
2344 	return rc;
2345 }
2346