xref: /linux/net/smc/smc_llc.c (revision e814f3fd16acfb7f9966773953de8f740a1e3202)
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 					u8 *llc_msg)
1002 {
1003 	struct smc_llc_msg_add_link_v2_ext *ext;
1004 	struct smc_link_group *lgr = link->lgr;
1005 	int max, i;
1006 
1007 	ext = (struct smc_llc_msg_add_link_v2_ext *)(llc_msg +
1008 						     SMC_WR_TX_SIZE);
1009 	max = min_t(u8, ext->num_rkeys, SMC_LLC_RKEYS_PER_MSG_V2);
1010 	down_write(&lgr->rmbs_lock);
1011 	for (i = 0; i < max; i++) {
1012 		smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1013 			       ext->rt[i].rmb_key,
1014 			       ext->rt[i].rmb_vaddr_new,
1015 			       ext->rt[i].rmb_key_new);
1016 	}
1017 	up_write(&lgr->rmbs_lock);
1018 }
1019 
1020 static void smc_llc_save_add_link_info(struct smc_link *link,
1021 				       struct smc_llc_msg_add_link *add_llc)
1022 {
1023 	link->peer_qpn = ntoh24(add_llc->sender_qp_num);
1024 	memcpy(link->peer_gid, add_llc->sender_gid, SMC_GID_SIZE);
1025 	memcpy(link->peer_mac, add_llc->sender_mac, ETH_ALEN);
1026 	link->peer_psn = ntoh24(add_llc->initial_psn);
1027 	link->peer_mtu = add_llc->qp_mtu;
1028 }
1029 
1030 /* as an SMC client, process an add link request */
1031 int smc_llc_cli_add_link(struct smc_link *link, struct smc_llc_qentry *qentry)
1032 {
1033 	struct smc_llc_msg_add_link *llc = &qentry->msg.add_link;
1034 	enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1035 	struct smc_link_group *lgr = smc_get_lgr(link);
1036 	struct smc_init_info *ini = NULL;
1037 	struct smc_link *lnk_new = NULL;
1038 	int lnk_idx, rc = 0;
1039 
1040 	if (!llc->qp_mtu)
1041 		goto out_reject;
1042 
1043 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1044 	if (!ini) {
1045 		rc = -ENOMEM;
1046 		goto out_reject;
1047 	}
1048 
1049 	if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1) {
1050 		rc = 0;
1051 		goto out_reject;
1052 	}
1053 
1054 	ini->vlan_id = lgr->vlan_id;
1055 	if (lgr->smc_version == SMC_V2) {
1056 		ini->check_smcrv2 = true;
1057 		ini->smcrv2.saddr = lgr->saddr;
1058 		ini->smcrv2.daddr = smc_ib_gid_to_ipv4(llc->sender_gid);
1059 	}
1060 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1061 	if (!memcmp(llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1062 	    (lgr->smc_version == SMC_V2 ||
1063 	     !memcmp(llc->sender_mac, link->peer_mac, ETH_ALEN))) {
1064 		if (!ini->ib_dev && !ini->smcrv2.ib_dev_v2)
1065 			goto out_reject;
1066 		lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1067 	}
1068 	if (lgr->smc_version == SMC_V2 && !ini->smcrv2.ib_dev_v2) {
1069 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1070 		ini->smcrv2.ib_dev_v2 = link->smcibdev;
1071 		ini->smcrv2.ib_port_v2 = link->ibport;
1072 	} else if (lgr->smc_version < SMC_V2 && !ini->ib_dev) {
1073 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1074 		ini->ib_dev = link->smcibdev;
1075 		ini->ib_port = link->ibport;
1076 	}
1077 	lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1078 	if (lnk_idx < 0)
1079 		goto out_reject;
1080 	lnk_new = &lgr->lnk[lnk_idx];
1081 	rc = smcr_link_init(lgr, lnk_new, lnk_idx, ini);
1082 	if (rc)
1083 		goto out_reject;
1084 	smc_llc_save_add_link_info(lnk_new, llc);
1085 	lnk_new->link_id = llc->link_num;	/* SMC server assigns link id */
1086 	smc_llc_link_set_uid(lnk_new);
1087 
1088 	rc = smc_ib_ready_link(lnk_new);
1089 	if (rc)
1090 		goto out_clear_lnk;
1091 
1092 	rc = smcr_buf_map_lgr(lnk_new);
1093 	if (rc)
1094 		goto out_clear_lnk;
1095 
1096 	rc = smc_llc_send_add_link(link,
1097 				   lnk_new->smcibdev->mac[lnk_new->ibport - 1],
1098 				   lnk_new->gid, lnk_new, SMC_LLC_RESP);
1099 	if (rc)
1100 		goto out_clear_lnk;
1101 	if (lgr->smc_version == SMC_V2) {
1102 		u8 *llc_msg = smc_link_shared_v2_rxbuf(link) ?
1103 			(u8 *)lgr->wr_rx_buf_v2 : (u8 *)llc;
1104 		smc_llc_save_add_link_rkeys(link, lnk_new, llc_msg);
1105 	} else {
1106 		rc = smc_llc_cli_rkey_exchange(link, lnk_new);
1107 		if (rc) {
1108 			rc = 0;
1109 			goto out_clear_lnk;
1110 		}
1111 	}
1112 	rc = smc_llc_cli_conf_link(link, ini, lnk_new, lgr_new_t);
1113 	if (!rc)
1114 		goto out;
1115 out_clear_lnk:
1116 	lnk_new->state = SMC_LNK_INACTIVE;
1117 	smcr_link_clear(lnk_new, false);
1118 out_reject:
1119 	smc_llc_cli_add_link_reject(qentry);
1120 out:
1121 	kfree(ini);
1122 	kfree(qentry);
1123 	return rc;
1124 }
1125 
1126 static void smc_llc_send_request_add_link(struct smc_link *link)
1127 {
1128 	struct smc_llc_msg_req_add_link_v2 *llc;
1129 	struct smc_wr_tx_pend_priv *pend;
1130 	struct smc_wr_v2_buf *wr_buf;
1131 	struct smc_gidlist gidlist;
1132 	int rc, len, i;
1133 
1134 	if (!smc_wr_tx_link_hold(link))
1135 		return;
1136 	if (link->lgr->type == SMC_LGR_SYMMETRIC ||
1137 	    link->lgr->type == SMC_LGR_ASYMMETRIC_PEER)
1138 		goto put_out;
1139 
1140 	smc_fill_gid_list(link->lgr, &gidlist, link->smcibdev, link->gid);
1141 	if (gidlist.len <= 1)
1142 		goto put_out;
1143 
1144 	rc = smc_llc_add_pending_send_v2(link, &wr_buf, &pend);
1145 	if (rc)
1146 		goto put_out;
1147 	llc = (struct smc_llc_msg_req_add_link_v2 *)wr_buf;
1148 	memset(llc, 0, SMC_WR_TX_SIZE);
1149 
1150 	llc->hd.common.llc_type = SMC_LLC_REQ_ADD_LINK;
1151 	for (i = 0; i < gidlist.len; i++)
1152 		memcpy(llc->gid[i], gidlist.list[i], sizeof(gidlist.list[0]));
1153 	llc->gid_cnt = gidlist.len;
1154 	len = sizeof(*llc) + (gidlist.len * sizeof(gidlist.list[0]));
1155 	smc_llc_init_msg_hdr(&llc->hd, link->lgr, len);
1156 	rc = smc_wr_tx_v2_send(link, pend, len);
1157 	if (!rc)
1158 		/* set REQ_ADD_LINK flow and wait for response from peer */
1159 		link->lgr->llc_flow_lcl.type = SMC_LLC_FLOW_REQ_ADD_LINK;
1160 put_out:
1161 	smc_wr_tx_link_put(link);
1162 }
1163 
1164 /* as an SMC client, invite server to start the add_link processing */
1165 static void smc_llc_cli_add_link_invite(struct smc_link *link,
1166 					struct smc_llc_qentry *qentry)
1167 {
1168 	struct smc_link_group *lgr = smc_get_lgr(link);
1169 	struct smc_init_info *ini = NULL;
1170 
1171 	if (lgr->smc_version == SMC_V2) {
1172 		smc_llc_send_request_add_link(link);
1173 		goto out;
1174 	}
1175 
1176 	if (lgr->type == SMC_LGR_SYMMETRIC ||
1177 	    lgr->type == SMC_LGR_ASYMMETRIC_PEER)
1178 		goto out;
1179 
1180 	if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
1181 		goto out;
1182 
1183 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1184 	if (!ini)
1185 		goto out;
1186 
1187 	ini->vlan_id = lgr->vlan_id;
1188 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1189 	if (!ini->ib_dev)
1190 		goto out;
1191 
1192 	smc_llc_send_add_link(link, ini->ib_dev->mac[ini->ib_port - 1],
1193 			      ini->ib_gid, NULL, SMC_LLC_REQ);
1194 out:
1195 	kfree(ini);
1196 	kfree(qentry);
1197 }
1198 
1199 static bool smc_llc_is_empty_llc_message(union smc_llc_msg *llc)
1200 {
1201 	int i;
1202 
1203 	for (i = 0; i < ARRAY_SIZE(llc->raw.data); i++)
1204 		if (llc->raw.data[i])
1205 			return false;
1206 	return true;
1207 }
1208 
1209 static bool smc_llc_is_local_add_link(union smc_llc_msg *llc)
1210 {
1211 	if (llc->raw.hdr.common.llc_type == SMC_LLC_ADD_LINK &&
1212 	    smc_llc_is_empty_llc_message(llc))
1213 		return true;
1214 	return false;
1215 }
1216 
1217 static void smc_llc_process_cli_add_link(struct smc_link_group *lgr)
1218 {
1219 	struct smc_llc_qentry *qentry;
1220 
1221 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1222 
1223 	down_write(&lgr->llc_conf_mutex);
1224 	if (smc_llc_is_local_add_link(&qentry->msg))
1225 		smc_llc_cli_add_link_invite(qentry->link, qentry);
1226 	else
1227 		smc_llc_cli_add_link(qentry->link, qentry);
1228 	up_write(&lgr->llc_conf_mutex);
1229 }
1230 
1231 static int smc_llc_active_link_count(struct smc_link_group *lgr)
1232 {
1233 	int i, link_count = 0;
1234 
1235 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1236 		if (!smc_link_active(&lgr->lnk[i]))
1237 			continue;
1238 		link_count++;
1239 	}
1240 	return link_count;
1241 }
1242 
1243 /* find the asymmetric link when 3 links are established  */
1244 static struct smc_link *smc_llc_find_asym_link(struct smc_link_group *lgr)
1245 {
1246 	int asym_idx = -ENOENT;
1247 	int i, j, k;
1248 	bool found;
1249 
1250 	/* determine asymmetric link */
1251 	found = false;
1252 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1253 		for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
1254 			if (!smc_link_usable(&lgr->lnk[i]) ||
1255 			    !smc_link_usable(&lgr->lnk[j]))
1256 				continue;
1257 			if (!memcmp(lgr->lnk[i].gid, lgr->lnk[j].gid,
1258 				    SMC_GID_SIZE)) {
1259 				found = true;	/* asym_lnk is i or j */
1260 				break;
1261 			}
1262 		}
1263 		if (found)
1264 			break;
1265 	}
1266 	if (!found)
1267 		goto out; /* no asymmetric link */
1268 	for (k = 0; k < SMC_LINKS_PER_LGR_MAX; k++) {
1269 		if (!smc_link_usable(&lgr->lnk[k]))
1270 			continue;
1271 		if (k != i &&
1272 		    !memcmp(lgr->lnk[i].peer_gid, lgr->lnk[k].peer_gid,
1273 			    SMC_GID_SIZE)) {
1274 			asym_idx = i;
1275 			break;
1276 		}
1277 		if (k != j &&
1278 		    !memcmp(lgr->lnk[j].peer_gid, lgr->lnk[k].peer_gid,
1279 			    SMC_GID_SIZE)) {
1280 			asym_idx = j;
1281 			break;
1282 		}
1283 	}
1284 out:
1285 	return (asym_idx < 0) ? NULL : &lgr->lnk[asym_idx];
1286 }
1287 
1288 static void smc_llc_delete_asym_link(struct smc_link_group *lgr)
1289 {
1290 	struct smc_link *lnk_new = NULL, *lnk_asym;
1291 	struct smc_llc_qentry *qentry;
1292 	int rc;
1293 
1294 	lnk_asym = smc_llc_find_asym_link(lgr);
1295 	if (!lnk_asym)
1296 		return; /* no asymmetric link */
1297 	if (!smc_link_downing(&lnk_asym->state))
1298 		return;
1299 	lnk_new = smc_switch_conns(lgr, lnk_asym, false);
1300 	smc_wr_tx_wait_no_pending_sends(lnk_asym);
1301 	if (!lnk_new)
1302 		goto out_free;
1303 	/* change flow type from ADD_LINK into DEL_LINK */
1304 	lgr->llc_flow_lcl.type = SMC_LLC_FLOW_DEL_LINK;
1305 	rc = smc_llc_send_delete_link(lnk_new, lnk_asym->link_id, SMC_LLC_REQ,
1306 				      true, SMC_LLC_DEL_NO_ASYM_NEEDED);
1307 	if (rc) {
1308 		smcr_link_down_cond(lnk_new);
1309 		goto out_free;
1310 	}
1311 	qentry = smc_llc_wait(lgr, lnk_new, SMC_LLC_WAIT_TIME,
1312 			      SMC_LLC_DELETE_LINK);
1313 	if (!qentry) {
1314 		smcr_link_down_cond(lnk_new);
1315 		goto out_free;
1316 	}
1317 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1318 out_free:
1319 	smcr_link_clear(lnk_asym, true);
1320 }
1321 
1322 static int smc_llc_srv_rkey_exchange(struct smc_link *link,
1323 				     struct smc_link *link_new)
1324 {
1325 	struct smc_llc_msg_add_link_cont *addc_llc;
1326 	struct smc_link_group *lgr = link->lgr;
1327 	u8 max, num_rkeys_send, num_rkeys_recv;
1328 	struct smc_llc_qentry *qentry = NULL;
1329 	struct smc_buf_desc *buf_pos;
1330 	int buf_lst;
1331 	int rc = 0;
1332 	int i;
1333 
1334 	down_write(&lgr->rmbs_lock);
1335 	num_rkeys_send = lgr->conns_num;
1336 	buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
1337 	do {
1338 		smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
1339 				      &buf_lst, &buf_pos);
1340 		qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME,
1341 				      SMC_LLC_ADD_LINK_CONT);
1342 		if (!qentry) {
1343 			rc = -ETIMEDOUT;
1344 			goto out;
1345 		}
1346 		addc_llc = &qentry->msg.add_link_cont;
1347 		num_rkeys_recv = addc_llc->num_rkeys;
1348 		max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
1349 		for (i = 0; i < max; i++) {
1350 			smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1351 				       addc_llc->rt[i].rmb_key,
1352 				       addc_llc->rt[i].rmb_vaddr_new,
1353 				       addc_llc->rt[i].rmb_key_new);
1354 			num_rkeys_recv--;
1355 		}
1356 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1357 	} while (num_rkeys_send || num_rkeys_recv);
1358 out:
1359 	up_write(&lgr->rmbs_lock);
1360 	return rc;
1361 }
1362 
1363 static int smc_llc_srv_conf_link(struct smc_link *link,
1364 				 struct smc_link *link_new,
1365 				 enum smc_lgr_type lgr_new_t)
1366 {
1367 	struct smc_link_group *lgr = link->lgr;
1368 	struct smc_llc_qentry *qentry = NULL;
1369 	int rc;
1370 
1371 	/* send CONFIRM LINK request over the RoCE fabric */
1372 	rc = smc_llc_send_confirm_link(link_new, SMC_LLC_REQ);
1373 	if (rc)
1374 		return -ENOLINK;
1375 	/* receive CONFIRM LINK response over the RoCE fabric */
1376 	qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_FIRST_TIME, 0);
1377 	if (!qentry ||
1378 	    qentry->msg.raw.hdr.common.llc_type != SMC_LLC_CONFIRM_LINK) {
1379 		/* send DELETE LINK */
1380 		smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
1381 					 false, SMC_LLC_DEL_LOST_PATH);
1382 		if (qentry)
1383 			smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1384 		return -ENOLINK;
1385 	}
1386 	smc_llc_save_peer_uid(qentry);
1387 	smc_llc_link_active(link_new);
1388 	if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
1389 	    lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
1390 		smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
1391 	else
1392 		smcr_lgr_set_type(lgr, lgr_new_t);
1393 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1394 	return 0;
1395 }
1396 
1397 static void smc_llc_send_req_add_link_response(struct smc_llc_qentry *qentry)
1398 {
1399 	qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
1400 	smc_llc_init_msg_hdr(&qentry->msg.raw.hdr, qentry->link->lgr,
1401 			     sizeof(qentry->msg));
1402 	memset(&qentry->msg.raw.data, 0, sizeof(qentry->msg.raw.data));
1403 	smc_llc_send_message(qentry->link, &qentry->msg);
1404 }
1405 
1406 int smc_llc_srv_add_link(struct smc_link *link,
1407 			 struct smc_llc_qentry *req_qentry)
1408 {
1409 	enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1410 	struct smc_link_group *lgr = link->lgr;
1411 	struct smc_llc_msg_add_link *add_llc;
1412 	struct smc_llc_qentry *qentry = NULL;
1413 	bool send_req_add_link_resp = false;
1414 	struct smc_link *link_new = NULL;
1415 	struct smc_init_info *ini = NULL;
1416 	int lnk_idx, rc = 0;
1417 
1418 	if (req_qentry &&
1419 	    req_qentry->msg.raw.hdr.common.llc_type == SMC_LLC_REQ_ADD_LINK)
1420 		send_req_add_link_resp = true;
1421 
1422 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
1423 	if (!ini) {
1424 		rc = -ENOMEM;
1425 		goto out;
1426 	}
1427 
1428 	if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1) {
1429 		rc = 0;
1430 		goto out;
1431 	}
1432 
1433 	/* ignore client add link recommendation, start new flow */
1434 	ini->vlan_id = lgr->vlan_id;
1435 	if (lgr->smc_version == SMC_V2) {
1436 		ini->check_smcrv2 = true;
1437 		ini->smcrv2.saddr = lgr->saddr;
1438 		if (send_req_add_link_resp) {
1439 			struct smc_llc_msg_req_add_link_v2 *req_add =
1440 				&req_qentry->msg.req_add_link;
1441 
1442 			ini->smcrv2.daddr = smc_ib_gid_to_ipv4(req_add->gid[0]);
1443 		}
1444 	}
1445 	smc_pnet_find_alt_roce(lgr, ini, link->smcibdev);
1446 	if (lgr->smc_version == SMC_V2 && !ini->smcrv2.ib_dev_v2) {
1447 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1448 		ini->smcrv2.ib_dev_v2 = link->smcibdev;
1449 		ini->smcrv2.ib_port_v2 = link->ibport;
1450 	} else if (lgr->smc_version < SMC_V2 && !ini->ib_dev) {
1451 		lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1452 		ini->ib_dev = link->smcibdev;
1453 		ini->ib_port = link->ibport;
1454 	}
1455 	lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1456 	if (lnk_idx < 0) {
1457 		rc = 0;
1458 		goto out;
1459 	}
1460 
1461 	rc = smcr_link_init(lgr, &lgr->lnk[lnk_idx], lnk_idx, ini);
1462 	if (rc)
1463 		goto out;
1464 	link_new = &lgr->lnk[lnk_idx];
1465 
1466 	rc = smcr_buf_map_lgr(link_new);
1467 	if (rc)
1468 		goto out_err;
1469 
1470 	rc = smc_llc_send_add_link(link,
1471 				   link_new->smcibdev->mac[link_new->ibport-1],
1472 				   link_new->gid, link_new, SMC_LLC_REQ);
1473 	if (rc)
1474 		goto out_err;
1475 	send_req_add_link_resp = false;
1476 	/* receive ADD LINK response over the RoCE fabric */
1477 	qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME, SMC_LLC_ADD_LINK);
1478 	if (!qentry) {
1479 		rc = -ETIMEDOUT;
1480 		goto out_err;
1481 	}
1482 	add_llc = &qentry->msg.add_link;
1483 	if (add_llc->hd.flags & SMC_LLC_FLAG_ADD_LNK_REJ) {
1484 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1485 		rc = -ENOLINK;
1486 		goto out_err;
1487 	}
1488 	if (lgr->type == SMC_LGR_SINGLE &&
1489 	    (!memcmp(add_llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1490 	     (lgr->smc_version == SMC_V2 ||
1491 	      !memcmp(add_llc->sender_mac, link->peer_mac, ETH_ALEN)))) {
1492 		lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1493 	}
1494 	smc_llc_save_add_link_info(link_new, add_llc);
1495 	smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1496 
1497 	rc = smc_ib_ready_link(link_new);
1498 	if (rc)
1499 		goto out_err;
1500 	rc = smcr_buf_reg_lgr(link_new);
1501 	if (rc)
1502 		goto out_err;
1503 	if (lgr->smc_version == SMC_V2) {
1504 		u8 *llc_msg = smc_link_shared_v2_rxbuf(link) ?
1505 			(u8 *)lgr->wr_rx_buf_v2 : (u8 *)add_llc;
1506 		smc_llc_save_add_link_rkeys(link, link_new, llc_msg);
1507 	} else {
1508 		rc = smc_llc_srv_rkey_exchange(link, link_new);
1509 		if (rc)
1510 			goto out_err;
1511 	}
1512 	rc = smc_llc_srv_conf_link(link, link_new, lgr_new_t);
1513 	if (rc)
1514 		goto out_err;
1515 	kfree(ini);
1516 	return 0;
1517 out_err:
1518 	if (link_new) {
1519 		link_new->state = SMC_LNK_INACTIVE;
1520 		smcr_link_clear(link_new, false);
1521 	}
1522 out:
1523 	kfree(ini);
1524 	if (send_req_add_link_resp)
1525 		smc_llc_send_req_add_link_response(req_qentry);
1526 	return rc;
1527 }
1528 
1529 static void smc_llc_process_srv_add_link(struct smc_link_group *lgr)
1530 {
1531 	struct smc_link *link = lgr->llc_flow_lcl.qentry->link;
1532 	struct smc_llc_qentry *qentry;
1533 	int rc;
1534 
1535 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1536 
1537 	down_write(&lgr->llc_conf_mutex);
1538 	rc = smc_llc_srv_add_link(link, qentry);
1539 	if (!rc && lgr->type == SMC_LGR_SYMMETRIC) {
1540 		/* delete any asymmetric link */
1541 		smc_llc_delete_asym_link(lgr);
1542 	}
1543 	up_write(&lgr->llc_conf_mutex);
1544 	kfree(qentry);
1545 }
1546 
1547 /* enqueue a local add_link req to trigger a new add_link flow */
1548 void smc_llc_add_link_local(struct smc_link *link)
1549 {
1550 	struct smc_llc_msg_add_link add_llc = {};
1551 
1552 	add_llc.hd.common.llc_type = SMC_LLC_ADD_LINK;
1553 	smc_llc_init_msg_hdr(&add_llc.hd, link->lgr, sizeof(add_llc));
1554 	/* no dev and port needed */
1555 	smc_llc_enqueue(link, (union smc_llc_msg *)&add_llc);
1556 }
1557 
1558 /* worker to process an add link message */
1559 static void smc_llc_add_link_work(struct work_struct *work)
1560 {
1561 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1562 						  llc_add_link_work);
1563 
1564 	if (list_empty(&lgr->list)) {
1565 		/* link group is terminating */
1566 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1567 		goto out;
1568 	}
1569 
1570 	if (lgr->role == SMC_CLNT)
1571 		smc_llc_process_cli_add_link(lgr);
1572 	else
1573 		smc_llc_process_srv_add_link(lgr);
1574 out:
1575 	if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_REQ_ADD_LINK)
1576 		smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1577 }
1578 
1579 /* enqueue a local del_link msg to trigger a new del_link flow,
1580  * called only for role SMC_SERV
1581  */
1582 void smc_llc_srv_delete_link_local(struct smc_link *link, u8 del_link_id)
1583 {
1584 	struct smc_llc_msg_del_link del_llc = {};
1585 
1586 	del_llc.hd.common.llc_type = SMC_LLC_DELETE_LINK;
1587 	smc_llc_init_msg_hdr(&del_llc.hd, link->lgr, sizeof(del_llc));
1588 	del_llc.link_num = del_link_id;
1589 	del_llc.reason = htonl(SMC_LLC_DEL_LOST_PATH);
1590 	del_llc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1591 	smc_llc_enqueue(link, (union smc_llc_msg *)&del_llc);
1592 }
1593 
1594 static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
1595 {
1596 	struct smc_link *lnk_del = NULL, *lnk_asym, *lnk;
1597 	struct smc_llc_msg_del_link *del_llc;
1598 	struct smc_llc_qentry *qentry;
1599 	int active_links;
1600 	int lnk_idx;
1601 
1602 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1603 	lnk = qentry->link;
1604 	del_llc = &qentry->msg.delete_link;
1605 
1606 	if (del_llc->hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1607 		smc_lgr_terminate_sched(lgr);
1608 		goto out;
1609 	}
1610 	down_write(&lgr->llc_conf_mutex);
1611 	/* delete single link */
1612 	for (lnk_idx = 0; lnk_idx < SMC_LINKS_PER_LGR_MAX; lnk_idx++) {
1613 		if (lgr->lnk[lnk_idx].link_id != del_llc->link_num)
1614 			continue;
1615 		lnk_del = &lgr->lnk[lnk_idx];
1616 		break;
1617 	}
1618 	del_llc->hd.flags |= SMC_LLC_FLAG_RESP;
1619 	if (!lnk_del) {
1620 		/* link was not found */
1621 		del_llc->reason = htonl(SMC_LLC_DEL_NOLNK);
1622 		smc_llc_send_message(lnk, &qentry->msg);
1623 		goto out_unlock;
1624 	}
1625 	lnk_asym = smc_llc_find_asym_link(lgr);
1626 
1627 	del_llc->reason = 0;
1628 	smc_llc_send_message(lnk, &qentry->msg); /* response */
1629 
1630 	if (smc_link_downing(&lnk_del->state))
1631 		smc_switch_conns(lgr, lnk_del, false);
1632 	smcr_link_clear(lnk_del, true);
1633 
1634 	active_links = smc_llc_active_link_count(lgr);
1635 	if (lnk_del == lnk_asym) {
1636 		/* expected deletion of asym link, don't change lgr state */
1637 	} else if (active_links == 1) {
1638 		smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1639 	} else if (!active_links) {
1640 		smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1641 		smc_lgr_terminate_sched(lgr);
1642 	}
1643 out_unlock:
1644 	up_write(&lgr->llc_conf_mutex);
1645 out:
1646 	kfree(qentry);
1647 }
1648 
1649 /* try to send a DELETE LINK ALL request on any active link,
1650  * waiting for send completion
1651  */
1652 void smc_llc_send_link_delete_all(struct smc_link_group *lgr, bool ord, u32 rsn)
1653 {
1654 	struct smc_llc_msg_del_link delllc = {};
1655 	int i;
1656 
1657 	delllc.hd.common.llc_type = SMC_LLC_DELETE_LINK;
1658 	smc_llc_init_msg_hdr(&delllc.hd, lgr, sizeof(delllc));
1659 	if (ord)
1660 		delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1661 	delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
1662 	delllc.reason = htonl(rsn);
1663 
1664 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1665 		if (!smc_link_sendable(&lgr->lnk[i]))
1666 			continue;
1667 		if (!smc_llc_send_message_wait(&lgr->lnk[i], &delllc))
1668 			break;
1669 	}
1670 }
1671 
1672 static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr)
1673 {
1674 	struct smc_llc_msg_del_link *del_llc;
1675 	struct smc_link *lnk, *lnk_del;
1676 	struct smc_llc_qentry *qentry;
1677 	int active_links;
1678 	int i;
1679 
1680 	down_write(&lgr->llc_conf_mutex);
1681 	qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1682 	lnk = qentry->link;
1683 	del_llc = &qentry->msg.delete_link;
1684 
1685 	if (qentry->msg.delete_link.hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1686 		/* delete entire lgr */
1687 		smc_llc_send_link_delete_all(lgr, true, ntohl(
1688 					      qentry->msg.delete_link.reason));
1689 		smc_lgr_terminate_sched(lgr);
1690 		goto out;
1691 	}
1692 	/* delete single link */
1693 	lnk_del = NULL;
1694 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1695 		if (lgr->lnk[i].link_id == del_llc->link_num) {
1696 			lnk_del = &lgr->lnk[i];
1697 			break;
1698 		}
1699 	}
1700 	if (!lnk_del)
1701 		goto out; /* asymmetric link already deleted */
1702 
1703 	if (smc_link_downing(&lnk_del->state)) {
1704 		if (smc_switch_conns(lgr, lnk_del, false))
1705 			smc_wr_tx_wait_no_pending_sends(lnk_del);
1706 	}
1707 	if (!list_empty(&lgr->list)) {
1708 		/* qentry is either a request from peer (send it back to
1709 		 * initiate the DELETE_LINK processing), or a locally
1710 		 * enqueued DELETE_LINK request (forward it)
1711 		 */
1712 		if (!smc_llc_send_message(lnk, &qentry->msg)) {
1713 			struct smc_llc_qentry *qentry2;
1714 
1715 			qentry2 = smc_llc_wait(lgr, lnk, SMC_LLC_WAIT_TIME,
1716 					       SMC_LLC_DELETE_LINK);
1717 			if (qentry2)
1718 				smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1719 		}
1720 	}
1721 	smcr_link_clear(lnk_del, true);
1722 
1723 	active_links = smc_llc_active_link_count(lgr);
1724 	if (active_links == 1) {
1725 		smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1726 	} else if (!active_links) {
1727 		smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1728 		smc_lgr_terminate_sched(lgr);
1729 	}
1730 
1731 	if (lgr->type == SMC_LGR_SINGLE && !list_empty(&lgr->list)) {
1732 		/* trigger setup of asymm alt link */
1733 		smc_llc_add_link_local(lnk);
1734 	}
1735 out:
1736 	up_write(&lgr->llc_conf_mutex);
1737 	kfree(qentry);
1738 }
1739 
1740 static void smc_llc_delete_link_work(struct work_struct *work)
1741 {
1742 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1743 						  llc_del_link_work);
1744 
1745 	if (list_empty(&lgr->list)) {
1746 		/* link group is terminating */
1747 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1748 		goto out;
1749 	}
1750 
1751 	if (lgr->role == SMC_CLNT)
1752 		smc_llc_process_cli_delete_link(lgr);
1753 	else
1754 		smc_llc_process_srv_delete_link(lgr);
1755 out:
1756 	smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1757 }
1758 
1759 /* process a confirm_rkey request from peer, remote flow */
1760 static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr)
1761 {
1762 	struct smc_llc_msg_confirm_rkey *llc;
1763 	struct smc_llc_qentry *qentry;
1764 	struct smc_link *link;
1765 	int num_entries;
1766 	int rk_idx;
1767 	int i;
1768 
1769 	qentry = lgr->llc_flow_rmt.qentry;
1770 	llc = &qentry->msg.confirm_rkey;
1771 	link = qentry->link;
1772 
1773 	num_entries = llc->rtoken[0].num_rkeys;
1774 	if (num_entries > SMC_LLC_RKEYS_PER_MSG)
1775 		goto out_err;
1776 	/* first rkey entry is for receiving link */
1777 	rk_idx = smc_rtoken_add(link,
1778 				llc->rtoken[0].rmb_vaddr,
1779 				llc->rtoken[0].rmb_key);
1780 	if (rk_idx < 0)
1781 		goto out_err;
1782 
1783 	for (i = 1; i <= min_t(u8, num_entries, SMC_LLC_RKEYS_PER_MSG - 1); i++)
1784 		smc_rtoken_set2(lgr, rk_idx, llc->rtoken[i].link_id,
1785 				llc->rtoken[i].rmb_vaddr,
1786 				llc->rtoken[i].rmb_key);
1787 	/* max links is 3 so there is no need to support conf_rkey_cont msgs */
1788 	goto out;
1789 out_err:
1790 	llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1791 	llc->hd.flags |= SMC_LLC_FLAG_RKEY_RETRY;
1792 out:
1793 	llc->hd.flags |= SMC_LLC_FLAG_RESP;
1794 	smc_llc_init_msg_hdr(&llc->hd, link->lgr, sizeof(*llc));
1795 	smc_llc_send_message(link, &qentry->msg);
1796 	smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1797 }
1798 
1799 /* process a delete_rkey request from peer, remote flow */
1800 static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr)
1801 {
1802 	struct smc_llc_msg_delete_rkey *llc;
1803 	struct smc_llc_qentry *qentry;
1804 	struct smc_link *link;
1805 	u8 err_mask = 0;
1806 	int i, max;
1807 
1808 	qentry = lgr->llc_flow_rmt.qentry;
1809 	llc = &qentry->msg.delete_rkey;
1810 	link = qentry->link;
1811 
1812 	if (lgr->smc_version == SMC_V2) {
1813 		struct smc_llc_msg_delete_rkey_v2 *llcv2;
1814 
1815 		if (smc_link_shared_v2_rxbuf(link)) {
1816 			memcpy(lgr->wr_rx_buf_v2, llc, sizeof(*llc));
1817 			llcv2 = (struct smc_llc_msg_delete_rkey_v2 *)lgr->wr_rx_buf_v2;
1818 		} else {
1819 			llcv2 = (struct smc_llc_msg_delete_rkey_v2 *)llc;
1820 		}
1821 		llcv2->num_inval_rkeys = 0;
1822 
1823 		max = min_t(u8, llcv2->num_rkeys, SMC_LLC_RKEYS_PER_MSG_V2);
1824 		for (i = 0; i < max; i++) {
1825 			if (smc_rtoken_delete(link, llcv2->rkey[i]))
1826 				llcv2->num_inval_rkeys++;
1827 		}
1828 		memset(&llc->rkey[0], 0, sizeof(llc->rkey));
1829 		memset(&llc->reserved2, 0, sizeof(llc->reserved2));
1830 		smc_llc_init_msg_hdr(&llc->hd, link->lgr, sizeof(*llc));
1831 		if (llcv2->num_inval_rkeys) {
1832 			llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1833 			llc->err_mask = llcv2->num_inval_rkeys;
1834 		}
1835 		goto finish;
1836 	}
1837 
1838 	max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
1839 	for (i = 0; i < max; i++) {
1840 		if (smc_rtoken_delete(link, llc->rkey[i]))
1841 			err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
1842 	}
1843 	if (err_mask) {
1844 		llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1845 		llc->err_mask = err_mask;
1846 	}
1847 finish:
1848 	llc->hd.flags |= SMC_LLC_FLAG_RESP;
1849 	smc_llc_send_message(link, &qentry->msg);
1850 	smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1851 }
1852 
1853 static void smc_llc_protocol_violation(struct smc_link_group *lgr, u8 type)
1854 {
1855 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu LLC protocol violation: "
1856 			    "llc_type %d\n", SMC_LGR_ID_SIZE, &lgr->id,
1857 			    lgr->net->net_cookie, type);
1858 	smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_PROT_VIOL);
1859 	smc_lgr_terminate_sched(lgr);
1860 }
1861 
1862 /* flush the llc event queue */
1863 static void smc_llc_event_flush(struct smc_link_group *lgr)
1864 {
1865 	struct smc_llc_qentry *qentry, *q;
1866 
1867 	spin_lock_bh(&lgr->llc_event_q_lock);
1868 	list_for_each_entry_safe(qentry, q, &lgr->llc_event_q, list) {
1869 		list_del_init(&qentry->list);
1870 		kfree(qentry);
1871 	}
1872 	spin_unlock_bh(&lgr->llc_event_q_lock);
1873 }
1874 
1875 static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
1876 {
1877 	union smc_llc_msg *llc = &qentry->msg;
1878 	struct smc_link *link = qentry->link;
1879 	struct smc_link_group *lgr = link->lgr;
1880 
1881 	if (!smc_link_usable(link))
1882 		goto out;
1883 
1884 	switch (llc->raw.hdr.common.llc_type) {
1885 	case SMC_LLC_TEST_LINK:
1886 		llc->test_link.hd.flags |= SMC_LLC_FLAG_RESP;
1887 		smc_llc_send_message(link, llc);
1888 		break;
1889 	case SMC_LLC_ADD_LINK:
1890 		if (list_empty(&lgr->list))
1891 			goto out;	/* lgr is terminating */
1892 		if (lgr->role == SMC_CLNT) {
1893 			if (smc_llc_is_local_add_link(llc)) {
1894 				if (lgr->llc_flow_lcl.type ==
1895 				    SMC_LLC_FLOW_ADD_LINK)
1896 					break;	/* add_link in progress */
1897 				if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1898 						       qentry)) {
1899 					schedule_work(&lgr->llc_add_link_work);
1900 				}
1901 				return;
1902 			}
1903 			if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1904 			    !lgr->llc_flow_lcl.qentry) {
1905 				/* a flow is waiting for this message */
1906 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1907 							qentry);
1908 				wake_up(&lgr->llc_msg_waiter);
1909 				return;
1910 			}
1911 			if (lgr->llc_flow_lcl.type ==
1912 					SMC_LLC_FLOW_REQ_ADD_LINK) {
1913 				/* server started add_link processing */
1914 				lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK;
1915 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1916 							qentry);
1917 				schedule_work(&lgr->llc_add_link_work);
1918 				return;
1919 			}
1920 			if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1921 				schedule_work(&lgr->llc_add_link_work);
1922 			}
1923 		} else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1924 			/* as smc server, handle client suggestion */
1925 			schedule_work(&lgr->llc_add_link_work);
1926 		}
1927 		return;
1928 	case SMC_LLC_CONFIRM_LINK:
1929 	case SMC_LLC_ADD_LINK_CONT:
1930 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1931 			/* a flow is waiting for this message */
1932 			smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1933 			wake_up(&lgr->llc_msg_waiter);
1934 			return;
1935 		}
1936 		break;
1937 	case SMC_LLC_DELETE_LINK:
1938 		if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1939 		    !lgr->llc_flow_lcl.qentry) {
1940 			/* DEL LINK REQ during ADD LINK SEQ */
1941 			smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1942 			wake_up(&lgr->llc_msg_waiter);
1943 		} else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1944 			schedule_work(&lgr->llc_del_link_work);
1945 		}
1946 		return;
1947 	case SMC_LLC_CONFIRM_RKEY:
1948 		/* new request from remote, assign to remote flow */
1949 		if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1950 			/* process here, does not wait for more llc msgs */
1951 			smc_llc_rmt_conf_rkey(lgr);
1952 			smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1953 		}
1954 		return;
1955 	case SMC_LLC_CONFIRM_RKEY_CONT:
1956 		/* not used because max links is 3, and 3 rkeys fit into
1957 		 * one CONFIRM_RKEY message
1958 		 */
1959 		break;
1960 	case SMC_LLC_DELETE_RKEY:
1961 		/* new request from remote, assign to remote flow */
1962 		if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1963 			/* process here, does not wait for more llc msgs */
1964 			smc_llc_rmt_delete_rkey(lgr);
1965 			smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1966 		}
1967 		return;
1968 	case SMC_LLC_REQ_ADD_LINK:
1969 		/* handle response here, smc_llc_flow_stop() cannot be called
1970 		 * in tasklet context
1971 		 */
1972 		if (lgr->role == SMC_CLNT &&
1973 		    lgr->llc_flow_lcl.type == SMC_LLC_FLOW_REQ_ADD_LINK &&
1974 		    (llc->raw.hdr.flags & SMC_LLC_FLAG_RESP)) {
1975 			smc_llc_flow_stop(link->lgr, &lgr->llc_flow_lcl);
1976 		} else if (lgr->role == SMC_SERV) {
1977 			if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1978 				/* as smc server, handle client suggestion */
1979 				lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK;
1980 				schedule_work(&lgr->llc_add_link_work);
1981 			}
1982 			return;
1983 		}
1984 		break;
1985 	default:
1986 		smc_llc_protocol_violation(lgr, llc->raw.hdr.common.type);
1987 		break;
1988 	}
1989 out:
1990 	kfree(qentry);
1991 }
1992 
1993 /* worker to process llc messages on the event queue */
1994 static void smc_llc_event_work(struct work_struct *work)
1995 {
1996 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1997 						  llc_event_work);
1998 	struct smc_llc_qentry *qentry;
1999 
2000 	if (!lgr->llc_flow_lcl.type && lgr->delayed_event) {
2001 		qentry = lgr->delayed_event;
2002 		lgr->delayed_event = NULL;
2003 		if (smc_link_usable(qentry->link))
2004 			smc_llc_event_handler(qentry);
2005 		else
2006 			kfree(qentry);
2007 	}
2008 
2009 again:
2010 	spin_lock_bh(&lgr->llc_event_q_lock);
2011 	if (!list_empty(&lgr->llc_event_q)) {
2012 		qentry = list_first_entry(&lgr->llc_event_q,
2013 					  struct smc_llc_qentry, list);
2014 		list_del_init(&qentry->list);
2015 		spin_unlock_bh(&lgr->llc_event_q_lock);
2016 		smc_llc_event_handler(qentry);
2017 		goto again;
2018 	}
2019 	spin_unlock_bh(&lgr->llc_event_q_lock);
2020 }
2021 
2022 /* process llc responses in tasklet context */
2023 static void smc_llc_rx_response(struct smc_link *link,
2024 				struct smc_llc_qentry *qentry)
2025 {
2026 	enum smc_llc_flowtype flowtype = link->lgr->llc_flow_lcl.type;
2027 	struct smc_llc_flow *flow = &link->lgr->llc_flow_lcl;
2028 	u8 llc_type = qentry->msg.raw.hdr.common.llc_type;
2029 
2030 	switch (llc_type) {
2031 	case SMC_LLC_TEST_LINK:
2032 		if (smc_link_active(link))
2033 			complete(&link->llc_testlink_resp);
2034 		break;
2035 	case SMC_LLC_ADD_LINK:
2036 	case SMC_LLC_ADD_LINK_CONT:
2037 	case SMC_LLC_CONFIRM_LINK:
2038 		if (flowtype != SMC_LLC_FLOW_ADD_LINK || flow->qentry)
2039 			break;	/* drop out-of-flow response */
2040 		goto assign;
2041 	case SMC_LLC_DELETE_LINK:
2042 		if (flowtype != SMC_LLC_FLOW_DEL_LINK || flow->qentry)
2043 			break;	/* drop out-of-flow response */
2044 		goto assign;
2045 	case SMC_LLC_CONFIRM_RKEY:
2046 	case SMC_LLC_DELETE_RKEY:
2047 		if (flowtype != SMC_LLC_FLOW_RKEY || flow->qentry)
2048 			break;	/* drop out-of-flow response */
2049 		goto assign;
2050 	case SMC_LLC_CONFIRM_RKEY_CONT:
2051 		/* not used because max links is 3 */
2052 		break;
2053 	default:
2054 		smc_llc_protocol_violation(link->lgr,
2055 					   qentry->msg.raw.hdr.common.type);
2056 		break;
2057 	}
2058 	kfree(qentry);
2059 	return;
2060 assign:
2061 	/* assign responses to the local flow, we requested them */
2062 	smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
2063 	wake_up(&link->lgr->llc_msg_waiter);
2064 }
2065 
2066 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc)
2067 {
2068 	struct smc_link_group *lgr = link->lgr;
2069 	struct smc_llc_qentry *qentry;
2070 	unsigned long flags;
2071 
2072 	qentry = kmalloc(sizeof(*qentry), GFP_ATOMIC);
2073 	if (!qentry)
2074 		return;
2075 	qentry->link = link;
2076 	INIT_LIST_HEAD(&qentry->list);
2077 	memcpy(&qentry->msg, llc, sizeof(union smc_llc_msg));
2078 
2079 	/* process responses immediately */
2080 	if ((llc->raw.hdr.flags & SMC_LLC_FLAG_RESP) &&
2081 	    llc->raw.hdr.common.llc_type != SMC_LLC_REQ_ADD_LINK) {
2082 		smc_llc_rx_response(link, qentry);
2083 		return;
2084 	}
2085 
2086 	/* add requests to event queue */
2087 	spin_lock_irqsave(&lgr->llc_event_q_lock, flags);
2088 	list_add_tail(&qentry->list, &lgr->llc_event_q);
2089 	spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags);
2090 	queue_work(system_highpri_wq, &lgr->llc_event_work);
2091 }
2092 
2093 /* copy received msg and add it to the event queue */
2094 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
2095 {
2096 	struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
2097 	union smc_llc_msg *llc = buf;
2098 
2099 	if (wc->byte_len < sizeof(*llc))
2100 		return; /* short message */
2101 	if (!llc->raw.hdr.common.llc_version) {
2102 		if (llc->raw.hdr.length != sizeof(*llc))
2103 			return; /* invalid message */
2104 	} else {
2105 		if (llc->raw.hdr.length_v2 < sizeof(*llc))
2106 			return; /* invalid message */
2107 	}
2108 
2109 	smc_llc_enqueue(link, llc);
2110 }
2111 
2112 /***************************** worker, utils *********************************/
2113 
2114 static void smc_llc_testlink_work(struct work_struct *work)
2115 {
2116 	struct smc_link *link = container_of(to_delayed_work(work),
2117 					     struct smc_link, llc_testlink_wrk);
2118 	unsigned long next_interval;
2119 	unsigned long expire_time;
2120 	u8 user_data[16] = { 0 };
2121 	int rc;
2122 
2123 	if (!smc_link_active(link))
2124 		return;		/* don't reschedule worker */
2125 	expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
2126 	if (time_is_after_jiffies(expire_time)) {
2127 		next_interval = expire_time - jiffies;
2128 		goto out;
2129 	}
2130 	reinit_completion(&link->llc_testlink_resp);
2131 	smc_llc_send_test_link(link, user_data);
2132 	/* receive TEST LINK response over RoCE fabric */
2133 	rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
2134 						       SMC_LLC_WAIT_TIME);
2135 	if (!smc_link_active(link))
2136 		return;		/* link state changed */
2137 	if (rc <= 0) {
2138 		smcr_link_down_cond_sched(link);
2139 		return;
2140 	}
2141 	next_interval = link->llc_testlink_time;
2142 out:
2143 	schedule_delayed_work(&link->llc_testlink_wrk, next_interval);
2144 }
2145 
2146 void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
2147 {
2148 	struct net *net = sock_net(smc->clcsock->sk);
2149 
2150 	INIT_WORK(&lgr->llc_event_work, smc_llc_event_work);
2151 	INIT_WORK(&lgr->llc_add_link_work, smc_llc_add_link_work);
2152 	INIT_WORK(&lgr->llc_del_link_work, smc_llc_delete_link_work);
2153 	INIT_LIST_HEAD(&lgr->llc_event_q);
2154 	spin_lock_init(&lgr->llc_event_q_lock);
2155 	spin_lock_init(&lgr->llc_flow_lock);
2156 	init_waitqueue_head(&lgr->llc_flow_waiter);
2157 	init_waitqueue_head(&lgr->llc_msg_waiter);
2158 	init_rwsem(&lgr->llc_conf_mutex);
2159 	lgr->llc_testlink_time = READ_ONCE(net->smc.sysctl_smcr_testlink_time);
2160 }
2161 
2162 /* called after lgr was removed from lgr_list */
2163 void smc_llc_lgr_clear(struct smc_link_group *lgr)
2164 {
2165 	smc_llc_event_flush(lgr);
2166 	wake_up_all(&lgr->llc_flow_waiter);
2167 	wake_up_all(&lgr->llc_msg_waiter);
2168 	cancel_work_sync(&lgr->llc_event_work);
2169 	cancel_work_sync(&lgr->llc_add_link_work);
2170 	cancel_work_sync(&lgr->llc_del_link_work);
2171 	if (lgr->delayed_event) {
2172 		kfree(lgr->delayed_event);
2173 		lgr->delayed_event = NULL;
2174 	}
2175 }
2176 
2177 int smc_llc_link_init(struct smc_link *link)
2178 {
2179 	init_completion(&link->llc_testlink_resp);
2180 	INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
2181 	return 0;
2182 }
2183 
2184 void smc_llc_link_active(struct smc_link *link)
2185 {
2186 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu link added: id %*phN, "
2187 			    "peerid %*phN, ibdev %s, ibport %d\n",
2188 			    SMC_LGR_ID_SIZE, &link->lgr->id,
2189 			    link->lgr->net->net_cookie,
2190 			    SMC_LGR_ID_SIZE, &link->link_uid,
2191 			    SMC_LGR_ID_SIZE, &link->peer_link_uid,
2192 			    link->smcibdev->ibdev->name, link->ibport);
2193 	link->state = SMC_LNK_ACTIVE;
2194 	if (link->lgr->llc_testlink_time) {
2195 		link->llc_testlink_time = link->lgr->llc_testlink_time;
2196 		schedule_delayed_work(&link->llc_testlink_wrk,
2197 				      link->llc_testlink_time);
2198 	}
2199 }
2200 
2201 /* called in worker context */
2202 void smc_llc_link_clear(struct smc_link *link, bool log)
2203 {
2204 	if (log)
2205 		pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu link removed: id %*phN"
2206 				    ", peerid %*phN, ibdev %s, ibport %d\n",
2207 				    SMC_LGR_ID_SIZE, &link->lgr->id,
2208 				    link->lgr->net->net_cookie,
2209 				    SMC_LGR_ID_SIZE, &link->link_uid,
2210 				    SMC_LGR_ID_SIZE, &link->peer_link_uid,
2211 				    link->smcibdev->ibdev->name, link->ibport);
2212 	complete(&link->llc_testlink_resp);
2213 	cancel_delayed_work_sync(&link->llc_testlink_wrk);
2214 }
2215 
2216 /* register a new rtoken at the remote peer (for all links) */
2217 int smc_llc_do_confirm_rkey(struct smc_link *send_link,
2218 			    struct smc_buf_desc *rmb_desc)
2219 {
2220 	struct smc_link_group *lgr = send_link->lgr;
2221 	struct smc_llc_qentry *qentry = NULL;
2222 	int rc = 0;
2223 
2224 	rc = smc_llc_send_confirm_rkey(send_link, rmb_desc);
2225 	if (rc)
2226 		goto out;
2227 	/* receive CONFIRM RKEY response from server over RoCE fabric */
2228 	qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
2229 			      SMC_LLC_CONFIRM_RKEY);
2230 	if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
2231 		rc = -EFAULT;
2232 out:
2233 	if (qentry)
2234 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
2235 	return rc;
2236 }
2237 
2238 /* unregister an rtoken at the remote peer */
2239 int smc_llc_do_delete_rkey(struct smc_link_group *lgr,
2240 			   struct smc_buf_desc *rmb_desc)
2241 {
2242 	struct smc_llc_qentry *qentry = NULL;
2243 	struct smc_link *send_link;
2244 	int rc = 0;
2245 
2246 	send_link = smc_llc_usable_link(lgr);
2247 	if (!send_link)
2248 		return -ENOLINK;
2249 
2250 	/* protected by llc_flow control */
2251 	rc = smc_llc_send_delete_rkey(send_link, rmb_desc);
2252 	if (rc)
2253 		goto out;
2254 	/* receive DELETE RKEY response from server over RoCE fabric */
2255 	qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
2256 			      SMC_LLC_DELETE_RKEY);
2257 	if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
2258 		rc = -EFAULT;
2259 out:
2260 	if (qentry)
2261 		smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
2262 	return rc;
2263 }
2264 
2265 void smc_llc_link_set_uid(struct smc_link *link)
2266 {
2267 	__be32 link_uid;
2268 
2269 	link_uid = htonl(*((u32 *)link->lgr->id) + link->link_id);
2270 	memcpy(link->link_uid, &link_uid, SMC_LGR_ID_SIZE);
2271 }
2272 
2273 /* save peers link user id, used for debug purposes */
2274 void smc_llc_save_peer_uid(struct smc_llc_qentry *qentry)
2275 {
2276 	memcpy(qentry->link->peer_link_uid, qentry->msg.confirm_link.link_uid,
2277 	       SMC_LGR_ID_SIZE);
2278 }
2279 
2280 /* evaluate confirm link request or response */
2281 int smc_llc_eval_conf_link(struct smc_llc_qentry *qentry,
2282 			   enum smc_llc_reqresp type)
2283 {
2284 	if (type == SMC_LLC_REQ) {	/* SMC server assigns link_id */
2285 		qentry->link->link_id = qentry->msg.confirm_link.link_num;
2286 		smc_llc_link_set_uid(qentry->link);
2287 	}
2288 	if (!(qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_NO_RMBE_EYEC))
2289 		return -ENOTSUPP;
2290 	return 0;
2291 }
2292 
2293 /***************************** init, exit, misc ******************************/
2294 
2295 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
2296 	{
2297 		.handler	= smc_llc_rx_handler,
2298 		.type		= SMC_LLC_CONFIRM_LINK
2299 	},
2300 	{
2301 		.handler	= smc_llc_rx_handler,
2302 		.type		= SMC_LLC_TEST_LINK
2303 	},
2304 	{
2305 		.handler	= smc_llc_rx_handler,
2306 		.type		= SMC_LLC_ADD_LINK
2307 	},
2308 	{
2309 		.handler	= smc_llc_rx_handler,
2310 		.type		= SMC_LLC_ADD_LINK_CONT
2311 	},
2312 	{
2313 		.handler	= smc_llc_rx_handler,
2314 		.type		= SMC_LLC_DELETE_LINK
2315 	},
2316 	{
2317 		.handler	= smc_llc_rx_handler,
2318 		.type		= SMC_LLC_CONFIRM_RKEY
2319 	},
2320 	{
2321 		.handler	= smc_llc_rx_handler,
2322 		.type		= SMC_LLC_CONFIRM_RKEY_CONT
2323 	},
2324 	{
2325 		.handler	= smc_llc_rx_handler,
2326 		.type		= SMC_LLC_DELETE_RKEY
2327 	},
2328 	/* V2 types */
2329 	{
2330 		.handler	= smc_llc_rx_handler,
2331 		.type		= SMC_LLC_CONFIRM_LINK_V2
2332 	},
2333 	{
2334 		.handler	= smc_llc_rx_handler,
2335 		.type		= SMC_LLC_TEST_LINK_V2
2336 	},
2337 	{
2338 		.handler	= smc_llc_rx_handler,
2339 		.type		= SMC_LLC_ADD_LINK_V2
2340 	},
2341 	{
2342 		.handler	= smc_llc_rx_handler,
2343 		.type		= SMC_LLC_DELETE_LINK_V2
2344 	},
2345 	{
2346 		.handler	= smc_llc_rx_handler,
2347 		.type		= SMC_LLC_REQ_ADD_LINK_V2
2348 	},
2349 	{
2350 		.handler	= smc_llc_rx_handler,
2351 		.type		= SMC_LLC_CONFIRM_RKEY_V2
2352 	},
2353 	{
2354 		.handler	= smc_llc_rx_handler,
2355 		.type		= SMC_LLC_DELETE_RKEY_V2
2356 	},
2357 	{
2358 		.handler	= NULL,
2359 	}
2360 };
2361 
2362 int __init smc_llc_init(void)
2363 {
2364 	struct smc_wr_rx_handler *handler;
2365 	int rc = 0;
2366 
2367 	for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
2368 		INIT_HLIST_NODE(&handler->list);
2369 		rc = smc_wr_rx_register_handler(handler);
2370 		if (rc)
2371 			break;
2372 	}
2373 	return rc;
2374 }
2375