xref: /openbmc/linux/net/smc/smc_llc.c (revision a17922de)
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 
21 #define SMC_LLC_DATA_LEN		40
22 
23 struct smc_llc_hdr {
24 	struct smc_wr_rx_hdr common;
25 	u8 length;	/* 44 */
26 #if defined(__BIG_ENDIAN_BITFIELD)
27 	u8 reserved:4,
28 	   add_link_rej_rsn:4;
29 #elif defined(__LITTLE_ENDIAN_BITFIELD)
30 	u8 add_link_rej_rsn:4,
31 	   reserved:4;
32 #endif
33 	u8 flags;
34 };
35 
36 #define SMC_LLC_FLAG_NO_RMBE_EYEC	0x03
37 
38 struct smc_llc_msg_confirm_link {	/* type 0x01 */
39 	struct smc_llc_hdr hd;
40 	u8 sender_mac[ETH_ALEN];
41 	u8 sender_gid[SMC_GID_SIZE];
42 	u8 sender_qp_num[3];
43 	u8 link_num;
44 	u8 link_uid[SMC_LGR_ID_SIZE];
45 	u8 max_links;
46 	u8 reserved[9];
47 };
48 
49 #define SMC_LLC_FLAG_ADD_LNK_REJ	0x40
50 #define SMC_LLC_REJ_RSN_NO_ALT_PATH	1
51 
52 #define SMC_LLC_ADD_LNK_MAX_LINKS	2
53 
54 struct smc_llc_msg_add_link {		/* type 0x02 */
55 	struct smc_llc_hdr hd;
56 	u8 sender_mac[ETH_ALEN];
57 	u8 reserved2[2];
58 	u8 sender_gid[SMC_GID_SIZE];
59 	u8 sender_qp_num[3];
60 	u8 link_num;
61 	u8 flags2;	/* QP mtu */
62 	u8 initial_psn[3];
63 	u8 reserved[8];
64 };
65 
66 #define SMC_LLC_FLAG_DEL_LINK_ALL	0x40
67 #define SMC_LLC_FLAG_DEL_LINK_ORDERLY	0x20
68 
69 struct smc_llc_msg_del_link {		/* type 0x04 */
70 	struct smc_llc_hdr hd;
71 	u8 link_num;
72 	__be32 reason;
73 	u8 reserved[35];
74 } __packed;			/* format defined in RFC7609 */
75 
76 struct smc_llc_msg_test_link {		/* type 0x07 */
77 	struct smc_llc_hdr hd;
78 	u8 user_data[16];
79 	u8 reserved[24];
80 };
81 
82 struct smc_rmb_rtoken {
83 	union {
84 		u8 num_rkeys;	/* first rtoken byte of CONFIRM LINK msg */
85 				/* is actually the num of rtokens, first */
86 				/* rtoken is always for the current link */
87 		u8 link_id;	/* link id of the rtoken */
88 	};
89 	__be32 rmb_key;
90 	__be64 rmb_vaddr;
91 } __packed;			/* format defined in RFC7609 */
92 
93 #define SMC_LLC_RKEYS_PER_MSG	3
94 
95 struct smc_llc_msg_confirm_rkey {	/* type 0x06 */
96 	struct smc_llc_hdr hd;
97 	struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
98 	u8 reserved;
99 };
100 
101 struct smc_llc_msg_confirm_rkey_cont {	/* type 0x08 */
102 	struct smc_llc_hdr hd;
103 	u8 num_rkeys;
104 	struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
105 };
106 
107 #define SMC_LLC_DEL_RKEY_MAX	8
108 #define SMC_LLC_FLAG_RKEY_NEG	0x20
109 
110 struct smc_llc_msg_delete_rkey {	/* type 0x09 */
111 	struct smc_llc_hdr hd;
112 	u8 num_rkeys;
113 	u8 err_mask;
114 	u8 reserved[2];
115 	__be32 rkey[8];
116 	u8 reserved2[4];
117 };
118 
119 union smc_llc_msg {
120 	struct smc_llc_msg_confirm_link confirm_link;
121 	struct smc_llc_msg_add_link add_link;
122 	struct smc_llc_msg_del_link delete_link;
123 
124 	struct smc_llc_msg_confirm_rkey confirm_rkey;
125 	struct smc_llc_msg_confirm_rkey_cont confirm_rkey_cont;
126 	struct smc_llc_msg_delete_rkey delete_rkey;
127 
128 	struct smc_llc_msg_test_link test_link;
129 	struct {
130 		struct smc_llc_hdr hdr;
131 		u8 data[SMC_LLC_DATA_LEN];
132 	} raw;
133 };
134 
135 #define SMC_LLC_FLAG_RESP		0x80
136 
137 /********************************** send *************************************/
138 
139 struct smc_llc_tx_pend {
140 };
141 
142 /* handler for send/transmission completion of an LLC msg */
143 static void smc_llc_tx_handler(struct smc_wr_tx_pend_priv *pend,
144 			       struct smc_link *link,
145 			       enum ib_wc_status wc_status)
146 {
147 	/* future work: handle wc_status error for recovery and failover */
148 }
149 
150 /**
151  * smc_llc_add_pending_send() - add LLC control message to pending WQE transmits
152  * @link: Pointer to SMC link used for sending LLC control message.
153  * @wr_buf: Out variable returning pointer to work request payload buffer.
154  * @pend: Out variable returning pointer to private pending WR tracking.
155  *	  It's the context the transmit complete handler will get.
156  *
157  * Reserves and pre-fills an entry for a pending work request send/tx.
158  * Used by mid-level smc_llc_send_msg() to prepare for later actual send/tx.
159  * Can sleep due to smc_get_ctrl_buf (if not in softirq context).
160  *
161  * Return: 0 on success, otherwise an error value.
162  */
163 static int smc_llc_add_pending_send(struct smc_link *link,
164 				    struct smc_wr_buf **wr_buf,
165 				    struct smc_wr_tx_pend_priv **pend)
166 {
167 	int rc;
168 
169 	rc = smc_wr_tx_get_free_slot(link, smc_llc_tx_handler, wr_buf, pend);
170 	if (rc < 0)
171 		return rc;
172 	BUILD_BUG_ON_MSG(
173 		sizeof(union smc_llc_msg) > SMC_WR_BUF_SIZE,
174 		"must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)");
175 	BUILD_BUG_ON_MSG(
176 		sizeof(union smc_llc_msg) != SMC_WR_TX_SIZE,
177 		"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()");
178 	BUILD_BUG_ON_MSG(
179 		sizeof(struct smc_llc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
180 		"must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_llc_tx_pend)");
181 	return 0;
182 }
183 
184 /* high-level API to send LLC confirm link */
185 int smc_llc_send_confirm_link(struct smc_link *link, u8 mac[],
186 			      union ib_gid *gid,
187 			      enum smc_llc_reqresp reqresp)
188 {
189 	struct smc_link_group *lgr = smc_get_lgr(link);
190 	struct smc_llc_msg_confirm_link *confllc;
191 	struct smc_wr_tx_pend_priv *pend;
192 	struct smc_wr_buf *wr_buf;
193 	int rc;
194 
195 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
196 	if (rc)
197 		return rc;
198 	confllc = (struct smc_llc_msg_confirm_link *)wr_buf;
199 	memset(confllc, 0, sizeof(*confllc));
200 	confllc->hd.common.type = SMC_LLC_CONFIRM_LINK;
201 	confllc->hd.length = sizeof(struct smc_llc_msg_confirm_link);
202 	confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
203 	if (reqresp == SMC_LLC_RESP)
204 		confllc->hd.flags |= SMC_LLC_FLAG_RESP;
205 	memcpy(confllc->sender_mac, mac, ETH_ALEN);
206 	memcpy(confllc->sender_gid, gid, SMC_GID_SIZE);
207 	hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
208 	confllc->link_num = link->link_id;
209 	memcpy(confllc->link_uid, lgr->id, SMC_LGR_ID_SIZE);
210 	confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS; /* enforce peer resp. */
211 	/* send llc message */
212 	rc = smc_wr_tx_send(link, pend);
213 	return rc;
214 }
215 
216 /* send LLC confirm rkey request */
217 static int smc_llc_send_confirm_rkey(struct smc_link *link,
218 				     struct smc_buf_desc *rmb_desc)
219 {
220 	struct smc_llc_msg_confirm_rkey *rkeyllc;
221 	struct smc_wr_tx_pend_priv *pend;
222 	struct smc_wr_buf *wr_buf;
223 	int rc;
224 
225 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
226 	if (rc)
227 		return rc;
228 	rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf;
229 	memset(rkeyllc, 0, sizeof(*rkeyllc));
230 	rkeyllc->hd.common.type = SMC_LLC_CONFIRM_RKEY;
231 	rkeyllc->hd.length = sizeof(struct smc_llc_msg_confirm_rkey);
232 	rkeyllc->rtoken[0].rmb_key =
233 		htonl(rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
234 	rkeyllc->rtoken[0].rmb_vaddr = cpu_to_be64(
235 		(u64)sg_dma_address(rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
236 	/* send llc message */
237 	rc = smc_wr_tx_send(link, pend);
238 	return rc;
239 }
240 
241 /* prepare an add link message */
242 static void smc_llc_prep_add_link(struct smc_llc_msg_add_link *addllc,
243 				  struct smc_link *link, u8 mac[],
244 				  union ib_gid *gid,
245 				  enum smc_llc_reqresp reqresp)
246 {
247 	memset(addllc, 0, sizeof(*addllc));
248 	addllc->hd.common.type = SMC_LLC_ADD_LINK;
249 	addllc->hd.length = sizeof(struct smc_llc_msg_add_link);
250 	if (reqresp == SMC_LLC_RESP) {
251 		addllc->hd.flags |= SMC_LLC_FLAG_RESP;
252 		/* always reject more links for now */
253 		addllc->hd.flags |= SMC_LLC_FLAG_ADD_LNK_REJ;
254 		addllc->hd.add_link_rej_rsn = SMC_LLC_REJ_RSN_NO_ALT_PATH;
255 	}
256 	memcpy(addllc->sender_mac, mac, ETH_ALEN);
257 	memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
258 }
259 
260 /* send ADD LINK request or response */
261 int smc_llc_send_add_link(struct smc_link *link, u8 mac[],
262 			  union ib_gid *gid,
263 			  enum smc_llc_reqresp reqresp)
264 {
265 	struct smc_llc_msg_add_link *addllc;
266 	struct smc_wr_tx_pend_priv *pend;
267 	struct smc_wr_buf *wr_buf;
268 	int rc;
269 
270 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
271 	if (rc)
272 		return rc;
273 	addllc = (struct smc_llc_msg_add_link *)wr_buf;
274 	smc_llc_prep_add_link(addllc, link, mac, gid, reqresp);
275 	/* send llc message */
276 	rc = smc_wr_tx_send(link, pend);
277 	return rc;
278 }
279 
280 /* prepare a delete link message */
281 static void smc_llc_prep_delete_link(struct smc_llc_msg_del_link *delllc,
282 				     struct smc_link *link,
283 				     enum smc_llc_reqresp reqresp)
284 {
285 	memset(delllc, 0, sizeof(*delllc));
286 	delllc->hd.common.type = SMC_LLC_DELETE_LINK;
287 	delllc->hd.length = sizeof(struct smc_llc_msg_add_link);
288 	if (reqresp == SMC_LLC_RESP)
289 		delllc->hd.flags |= SMC_LLC_FLAG_RESP;
290 	/* DEL_LINK_ALL because only 1 link supported */
291 	delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
292 	delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
293 	delllc->link_num = link->link_id;
294 }
295 
296 /* send DELETE LINK request or response */
297 int smc_llc_send_delete_link(struct smc_link *link,
298 			     enum smc_llc_reqresp reqresp)
299 {
300 	struct smc_llc_msg_del_link *delllc;
301 	struct smc_wr_tx_pend_priv *pend;
302 	struct smc_wr_buf *wr_buf;
303 	int rc;
304 
305 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
306 	if (rc)
307 		return rc;
308 	delllc = (struct smc_llc_msg_del_link *)wr_buf;
309 	smc_llc_prep_delete_link(delllc, link, reqresp);
310 	/* send llc message */
311 	rc = smc_wr_tx_send(link, pend);
312 	return rc;
313 }
314 
315 /* send LLC test link request */
316 static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
317 {
318 	struct smc_llc_msg_test_link *testllc;
319 	struct smc_wr_tx_pend_priv *pend;
320 	struct smc_wr_buf *wr_buf;
321 	int rc;
322 
323 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
324 	if (rc)
325 		return rc;
326 	testllc = (struct smc_llc_msg_test_link *)wr_buf;
327 	memset(testllc, 0, sizeof(*testllc));
328 	testllc->hd.common.type = SMC_LLC_TEST_LINK;
329 	testllc->hd.length = sizeof(struct smc_llc_msg_test_link);
330 	memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
331 	/* send llc message */
332 	rc = smc_wr_tx_send(link, pend);
333 	return rc;
334 }
335 
336 struct smc_llc_send_work {
337 	struct work_struct work;
338 	struct smc_link *link;
339 	int llclen;
340 	union smc_llc_msg llcbuf;
341 };
342 
343 /* worker that sends a prepared message */
344 static void smc_llc_send_message_work(struct work_struct *work)
345 {
346 	struct smc_llc_send_work *llcwrk = container_of(work,
347 						struct smc_llc_send_work, work);
348 	struct smc_wr_tx_pend_priv *pend;
349 	struct smc_wr_buf *wr_buf;
350 	int rc;
351 
352 	if (llcwrk->link->state == SMC_LNK_INACTIVE)
353 		goto out;
354 	rc = smc_llc_add_pending_send(llcwrk->link, &wr_buf, &pend);
355 	if (rc)
356 		goto out;
357 	memcpy(wr_buf, &llcwrk->llcbuf, llcwrk->llclen);
358 	smc_wr_tx_send(llcwrk->link, pend);
359 out:
360 	kfree(llcwrk);
361 }
362 
363 /* copy llcbuf and schedule an llc send on link */
364 static int smc_llc_send_message(struct smc_link *link, void *llcbuf, int llclen)
365 {
366 	struct smc_llc_send_work *wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
367 
368 	if (!wrk)
369 		return -ENOMEM;
370 	INIT_WORK(&wrk->work, smc_llc_send_message_work);
371 	wrk->link = link;
372 	wrk->llclen = llclen;
373 	memcpy(&wrk->llcbuf, llcbuf, llclen);
374 	queue_work(link->llc_wq, &wrk->work);
375 	return 0;
376 }
377 
378 /********************************* receive ***********************************/
379 
380 static void smc_llc_rx_confirm_link(struct smc_link *link,
381 				    struct smc_llc_msg_confirm_link *llc)
382 {
383 	struct smc_link_group *lgr = smc_get_lgr(link);
384 	int conf_rc;
385 
386 	/* RMBE eyecatchers are not supported */
387 	if (llc->hd.flags & SMC_LLC_FLAG_NO_RMBE_EYEC)
388 		conf_rc = 0;
389 	else
390 		conf_rc = ENOTSUPP;
391 
392 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
393 		if (lgr->role == SMC_SERV &&
394 		    link->state == SMC_LNK_ACTIVATING) {
395 			link->llc_confirm_resp_rc = conf_rc;
396 			complete(&link->llc_confirm_resp);
397 		}
398 	} else {
399 		if (lgr->role == SMC_CLNT &&
400 		    link->state == SMC_LNK_ACTIVATING) {
401 			link->llc_confirm_rc = conf_rc;
402 			link->link_id = llc->link_num;
403 			complete(&link->llc_confirm);
404 		}
405 	}
406 }
407 
408 static void smc_llc_rx_add_link(struct smc_link *link,
409 				struct smc_llc_msg_add_link *llc)
410 {
411 	struct smc_link_group *lgr = smc_get_lgr(link);
412 
413 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
414 		if (link->state == SMC_LNK_ACTIVATING)
415 			complete(&link->llc_add_resp);
416 	} else {
417 		if (link->state == SMC_LNK_ACTIVATING) {
418 			complete(&link->llc_add);
419 			return;
420 		}
421 
422 		if (lgr->role == SMC_SERV) {
423 			smc_llc_prep_add_link(llc, link,
424 					link->smcibdev->mac[link->ibport - 1],
425 					&link->smcibdev->gid[link->ibport - 1],
426 					SMC_LLC_REQ);
427 
428 		} else {
429 			smc_llc_prep_add_link(llc, link,
430 					link->smcibdev->mac[link->ibport - 1],
431 					&link->smcibdev->gid[link->ibport - 1],
432 					SMC_LLC_RESP);
433 		}
434 		smc_llc_send_message(link, llc, sizeof(*llc));
435 	}
436 }
437 
438 static void smc_llc_rx_delete_link(struct smc_link *link,
439 				   struct smc_llc_msg_del_link *llc)
440 {
441 	struct smc_link_group *lgr = smc_get_lgr(link);
442 
443 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
444 		if (lgr->role == SMC_SERV)
445 			smc_lgr_terminate(lgr);
446 	} else {
447 		if (lgr->role == SMC_SERV) {
448 			smc_lgr_forget(lgr);
449 			smc_llc_prep_delete_link(llc, link, SMC_LLC_REQ);
450 			smc_llc_send_message(link, llc, sizeof(*llc));
451 		} else {
452 			smc_llc_prep_delete_link(llc, link, SMC_LLC_RESP);
453 			smc_llc_send_message(link, llc, sizeof(*llc));
454 			smc_lgr_terminate(lgr);
455 		}
456 	}
457 }
458 
459 static void smc_llc_rx_test_link(struct smc_link *link,
460 				 struct smc_llc_msg_test_link *llc)
461 {
462 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
463 		if (link->state == SMC_LNK_ACTIVE)
464 			complete(&link->llc_testlink_resp);
465 	} else {
466 		llc->hd.flags |= SMC_LLC_FLAG_RESP;
467 		smc_llc_send_message(link, llc, sizeof(*llc));
468 	}
469 }
470 
471 static void smc_llc_rx_confirm_rkey(struct smc_link *link,
472 				    struct smc_llc_msg_confirm_rkey *llc)
473 {
474 	int rc;
475 
476 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
477 		link->llc_confirm_rkey_rc = llc->hd.flags &
478 					    SMC_LLC_FLAG_RKEY_NEG;
479 		complete(&link->llc_confirm_rkey);
480 	} else {
481 		rc = smc_rtoken_add(smc_get_lgr(link),
482 				    llc->rtoken[0].rmb_vaddr,
483 				    llc->rtoken[0].rmb_key);
484 
485 		/* ignore rtokens for other links, we have only one link */
486 
487 		llc->hd.flags |= SMC_LLC_FLAG_RESP;
488 		if (rc < 0)
489 			llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
490 		smc_llc_send_message(link, llc, sizeof(*llc));
491 	}
492 }
493 
494 static void smc_llc_rx_confirm_rkey_cont(struct smc_link *link,
495 				      struct smc_llc_msg_confirm_rkey_cont *llc)
496 {
497 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
498 		/* unused as long as we don't send this type of msg */
499 	} else {
500 		/* ignore rtokens for other links, we have only one link */
501 		llc->hd.flags |= SMC_LLC_FLAG_RESP;
502 		smc_llc_send_message(link, llc, sizeof(*llc));
503 	}
504 }
505 
506 static void smc_llc_rx_delete_rkey(struct smc_link *link,
507 				   struct smc_llc_msg_delete_rkey *llc)
508 {
509 	u8 err_mask = 0;
510 	int i, max;
511 
512 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
513 		/* unused as long as we don't send this type of msg */
514 	} else {
515 		max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
516 		for (i = 0; i < max; i++) {
517 			if (smc_rtoken_delete(smc_get_lgr(link), llc->rkey[i]))
518 				err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
519 		}
520 
521 		if (err_mask) {
522 			llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
523 			llc->err_mask = err_mask;
524 		}
525 
526 		llc->hd.flags |= SMC_LLC_FLAG_RESP;
527 		smc_llc_send_message(link, llc, sizeof(*llc));
528 	}
529 }
530 
531 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
532 {
533 	struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
534 	union smc_llc_msg *llc = buf;
535 
536 	if (wc->byte_len < sizeof(*llc))
537 		return; /* short message */
538 	if (llc->raw.hdr.length != sizeof(*llc))
539 		return; /* invalid message */
540 	if (link->state == SMC_LNK_INACTIVE)
541 		return; /* link not active, drop msg */
542 
543 	switch (llc->raw.hdr.common.type) {
544 	case SMC_LLC_TEST_LINK:
545 		smc_llc_rx_test_link(link, &llc->test_link);
546 		break;
547 	case SMC_LLC_CONFIRM_LINK:
548 		smc_llc_rx_confirm_link(link, &llc->confirm_link);
549 		break;
550 	case SMC_LLC_ADD_LINK:
551 		smc_llc_rx_add_link(link, &llc->add_link);
552 		break;
553 	case SMC_LLC_DELETE_LINK:
554 		smc_llc_rx_delete_link(link, &llc->delete_link);
555 		break;
556 	case SMC_LLC_CONFIRM_RKEY:
557 		smc_llc_rx_confirm_rkey(link, &llc->confirm_rkey);
558 		break;
559 	case SMC_LLC_CONFIRM_RKEY_CONT:
560 		smc_llc_rx_confirm_rkey_cont(link, &llc->confirm_rkey_cont);
561 		break;
562 	case SMC_LLC_DELETE_RKEY:
563 		smc_llc_rx_delete_rkey(link, &llc->delete_rkey);
564 		break;
565 	}
566 }
567 
568 /***************************** worker, utils *********************************/
569 
570 static void smc_llc_testlink_work(struct work_struct *work)
571 {
572 	struct smc_link *link = container_of(to_delayed_work(work),
573 					     struct smc_link, llc_testlink_wrk);
574 	unsigned long next_interval;
575 	unsigned long expire_time;
576 	u8 user_data[16] = { 0 };
577 	int rc;
578 
579 	if (link->state != SMC_LNK_ACTIVE)
580 		return;		/* don't reschedule worker */
581 	expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
582 	if (time_is_after_jiffies(expire_time)) {
583 		next_interval = expire_time - jiffies;
584 		goto out;
585 	}
586 	reinit_completion(&link->llc_testlink_resp);
587 	smc_llc_send_test_link(link, user_data);
588 	/* receive TEST LINK response over RoCE fabric */
589 	rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
590 						       SMC_LLC_WAIT_TIME);
591 	if (rc <= 0) {
592 		smc_lgr_terminate(smc_get_lgr(link));
593 		return;
594 	}
595 	next_interval = link->llc_testlink_time;
596 out:
597 	queue_delayed_work(link->llc_wq, &link->llc_testlink_wrk,
598 			   next_interval);
599 }
600 
601 int smc_llc_link_init(struct smc_link *link)
602 {
603 	struct smc_link_group *lgr = smc_get_lgr(link);
604 	link->llc_wq = alloc_ordered_workqueue("llc_wq-%x:%x)", WQ_MEM_RECLAIM,
605 					       *((u32 *)lgr->id),
606 					       link->link_id);
607 	if (!link->llc_wq)
608 		return -ENOMEM;
609 	init_completion(&link->llc_confirm);
610 	init_completion(&link->llc_confirm_resp);
611 	init_completion(&link->llc_add);
612 	init_completion(&link->llc_add_resp);
613 	init_completion(&link->llc_confirm_rkey);
614 	init_completion(&link->llc_testlink_resp);
615 	INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
616 	return 0;
617 }
618 
619 void smc_llc_link_active(struct smc_link *link, int testlink_time)
620 {
621 	link->state = SMC_LNK_ACTIVE;
622 	if (testlink_time) {
623 		link->llc_testlink_time = testlink_time * HZ;
624 		queue_delayed_work(link->llc_wq, &link->llc_testlink_wrk,
625 				   link->llc_testlink_time);
626 	}
627 }
628 
629 /* called in tasklet context */
630 void smc_llc_link_inactive(struct smc_link *link)
631 {
632 	link->state = SMC_LNK_INACTIVE;
633 	cancel_delayed_work(&link->llc_testlink_wrk);
634 }
635 
636 /* called in worker context */
637 void smc_llc_link_clear(struct smc_link *link)
638 {
639 	flush_workqueue(link->llc_wq);
640 	destroy_workqueue(link->llc_wq);
641 }
642 
643 /* register a new rtoken at the remote peer */
644 int smc_llc_do_confirm_rkey(struct smc_link *link,
645 			    struct smc_buf_desc *rmb_desc)
646 {
647 	int rc;
648 
649 	reinit_completion(&link->llc_confirm_rkey);
650 	smc_llc_send_confirm_rkey(link, rmb_desc);
651 	/* receive CONFIRM RKEY response from server over RoCE fabric */
652 	rc = wait_for_completion_interruptible_timeout(&link->llc_confirm_rkey,
653 						       SMC_LLC_WAIT_TIME);
654 	if (rc <= 0 || link->llc_confirm_rkey_rc)
655 		return -EFAULT;
656 	return 0;
657 }
658 
659 /***************************** init, exit, misc ******************************/
660 
661 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
662 	{
663 		.handler	= smc_llc_rx_handler,
664 		.type		= SMC_LLC_CONFIRM_LINK
665 	},
666 	{
667 		.handler	= smc_llc_rx_handler,
668 		.type		= SMC_LLC_TEST_LINK
669 	},
670 	{
671 		.handler	= smc_llc_rx_handler,
672 		.type		= SMC_LLC_ADD_LINK
673 	},
674 	{
675 		.handler	= smc_llc_rx_handler,
676 		.type		= SMC_LLC_DELETE_LINK
677 	},
678 	{
679 		.handler	= smc_llc_rx_handler,
680 		.type		= SMC_LLC_CONFIRM_RKEY
681 	},
682 	{
683 		.handler	= smc_llc_rx_handler,
684 		.type		= SMC_LLC_CONFIRM_RKEY_CONT
685 	},
686 	{
687 		.handler	= smc_llc_rx_handler,
688 		.type		= SMC_LLC_DELETE_RKEY
689 	},
690 	{
691 		.handler	= NULL,
692 	}
693 };
694 
695 int __init smc_llc_init(void)
696 {
697 	struct smc_wr_rx_handler *handler;
698 	int rc = 0;
699 
700 	for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
701 		INIT_HLIST_NODE(&handler->list);
702 		rc = smc_wr_rx_register_handler(handler);
703 		if (rc)
704 			break;
705 	}
706 	return rc;
707 }
708