xref: /openbmc/linux/net/smc/smc_llc.c (revision 96de2506)
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,
186 			      enum smc_llc_reqresp reqresp)
187 {
188 	struct smc_link_group *lgr = smc_get_lgr(link);
189 	struct smc_llc_msg_confirm_link *confllc;
190 	struct smc_wr_tx_pend_priv *pend;
191 	struct smc_wr_buf *wr_buf;
192 	int rc;
193 
194 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
195 	if (rc)
196 		return rc;
197 	confllc = (struct smc_llc_msg_confirm_link *)wr_buf;
198 	memset(confllc, 0, sizeof(*confllc));
199 	confllc->hd.common.type = SMC_LLC_CONFIRM_LINK;
200 	confllc->hd.length = sizeof(struct smc_llc_msg_confirm_link);
201 	confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
202 	if (reqresp == SMC_LLC_RESP)
203 		confllc->hd.flags |= SMC_LLC_FLAG_RESP;
204 	memcpy(confllc->sender_mac, link->smcibdev->mac[link->ibport - 1],
205 	       ETH_ALEN);
206 	memcpy(confllc->sender_gid, link->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[], u8 gid[],
244 				  enum smc_llc_reqresp reqresp)
245 {
246 	memset(addllc, 0, sizeof(*addllc));
247 	addllc->hd.common.type = SMC_LLC_ADD_LINK;
248 	addllc->hd.length = sizeof(struct smc_llc_msg_add_link);
249 	if (reqresp == SMC_LLC_RESP) {
250 		addllc->hd.flags |= SMC_LLC_FLAG_RESP;
251 		/* always reject more links for now */
252 		addllc->hd.flags |= SMC_LLC_FLAG_ADD_LNK_REJ;
253 		addllc->hd.add_link_rej_rsn = SMC_LLC_REJ_RSN_NO_ALT_PATH;
254 	}
255 	memcpy(addllc->sender_mac, mac, ETH_ALEN);
256 	memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
257 }
258 
259 /* send ADD LINK request or response */
260 int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[],
261 			  enum smc_llc_reqresp reqresp)
262 {
263 	struct smc_llc_msg_add_link *addllc;
264 	struct smc_wr_tx_pend_priv *pend;
265 	struct smc_wr_buf *wr_buf;
266 	int rc;
267 
268 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
269 	if (rc)
270 		return rc;
271 	addllc = (struct smc_llc_msg_add_link *)wr_buf;
272 	smc_llc_prep_add_link(addllc, link, mac, gid, reqresp);
273 	/* send llc message */
274 	rc = smc_wr_tx_send(link, pend);
275 	return rc;
276 }
277 
278 /* prepare a delete link message */
279 static void smc_llc_prep_delete_link(struct smc_llc_msg_del_link *delllc,
280 				     struct smc_link *link,
281 				     enum smc_llc_reqresp reqresp, bool orderly)
282 {
283 	memset(delllc, 0, sizeof(*delllc));
284 	delllc->hd.common.type = SMC_LLC_DELETE_LINK;
285 	delllc->hd.length = sizeof(struct smc_llc_msg_add_link);
286 	if (reqresp == SMC_LLC_RESP)
287 		delllc->hd.flags |= SMC_LLC_FLAG_RESP;
288 	/* DEL_LINK_ALL because only 1 link supported */
289 	delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
290 	if (orderly)
291 		delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
292 	delllc->link_num = link->link_id;
293 }
294 
295 /* send DELETE LINK request or response */
296 int smc_llc_send_delete_link(struct smc_link *link,
297 			     enum smc_llc_reqresp reqresp, bool orderly)
298 {
299 	struct smc_llc_msg_del_link *delllc;
300 	struct smc_wr_tx_pend_priv *pend;
301 	struct smc_wr_buf *wr_buf;
302 	int rc;
303 
304 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
305 	if (rc)
306 		return rc;
307 	delllc = (struct smc_llc_msg_del_link *)wr_buf;
308 	smc_llc_prep_delete_link(delllc, link, reqresp, orderly);
309 	/* send llc message */
310 	rc = smc_wr_tx_send(link, pend);
311 	return rc;
312 }
313 
314 /* send LLC test link request */
315 static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
316 {
317 	struct smc_llc_msg_test_link *testllc;
318 	struct smc_wr_tx_pend_priv *pend;
319 	struct smc_wr_buf *wr_buf;
320 	int rc;
321 
322 	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
323 	if (rc)
324 		return rc;
325 	testllc = (struct smc_llc_msg_test_link *)wr_buf;
326 	memset(testllc, 0, sizeof(*testllc));
327 	testllc->hd.common.type = SMC_LLC_TEST_LINK;
328 	testllc->hd.length = sizeof(struct smc_llc_msg_test_link);
329 	memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
330 	/* send llc message */
331 	rc = smc_wr_tx_send(link, pend);
332 	return rc;
333 }
334 
335 struct smc_llc_send_work {
336 	struct work_struct work;
337 	struct smc_link *link;
338 	int llclen;
339 	union smc_llc_msg llcbuf;
340 };
341 
342 /* worker that sends a prepared message */
343 static void smc_llc_send_message_work(struct work_struct *work)
344 {
345 	struct smc_llc_send_work *llcwrk = container_of(work,
346 						struct smc_llc_send_work, work);
347 	struct smc_wr_tx_pend_priv *pend;
348 	struct smc_wr_buf *wr_buf;
349 	int rc;
350 
351 	if (llcwrk->link->state == SMC_LNK_INACTIVE)
352 		goto out;
353 	rc = smc_llc_add_pending_send(llcwrk->link, &wr_buf, &pend);
354 	if (rc)
355 		goto out;
356 	memcpy(wr_buf, &llcwrk->llcbuf, llcwrk->llclen);
357 	smc_wr_tx_send(llcwrk->link, pend);
358 out:
359 	kfree(llcwrk);
360 }
361 
362 /* copy llcbuf and schedule an llc send on link */
363 static int smc_llc_send_message(struct smc_link *link, void *llcbuf, int llclen)
364 {
365 	struct smc_llc_send_work *wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
366 
367 	if (!wrk)
368 		return -ENOMEM;
369 	INIT_WORK(&wrk->work, smc_llc_send_message_work);
370 	wrk->link = link;
371 	wrk->llclen = llclen;
372 	memcpy(&wrk->llcbuf, llcbuf, llclen);
373 	queue_work(link->llc_wq, &wrk->work);
374 	return 0;
375 }
376 
377 /********************************* receive ***********************************/
378 
379 static void smc_llc_rx_confirm_link(struct smc_link *link,
380 				    struct smc_llc_msg_confirm_link *llc)
381 {
382 	struct smc_link_group *lgr = smc_get_lgr(link);
383 	int conf_rc;
384 
385 	/* RMBE eyecatchers are not supported */
386 	if (llc->hd.flags & SMC_LLC_FLAG_NO_RMBE_EYEC)
387 		conf_rc = 0;
388 	else
389 		conf_rc = ENOTSUPP;
390 
391 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
392 		if (lgr->role == SMC_SERV &&
393 		    link->state == SMC_LNK_ACTIVATING) {
394 			link->llc_confirm_resp_rc = conf_rc;
395 			complete(&link->llc_confirm_resp);
396 		}
397 	} else {
398 		if (lgr->role == SMC_CLNT &&
399 		    link->state == SMC_LNK_ACTIVATING) {
400 			link->llc_confirm_rc = conf_rc;
401 			link->link_id = llc->link_num;
402 			complete(&link->llc_confirm);
403 		}
404 	}
405 }
406 
407 static void smc_llc_rx_add_link(struct smc_link *link,
408 				struct smc_llc_msg_add_link *llc)
409 {
410 	struct smc_link_group *lgr = smc_get_lgr(link);
411 
412 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
413 		if (link->state == SMC_LNK_ACTIVATING)
414 			complete(&link->llc_add_resp);
415 	} else {
416 		if (link->state == SMC_LNK_ACTIVATING) {
417 			complete(&link->llc_add);
418 			return;
419 		}
420 
421 		if (lgr->role == SMC_SERV) {
422 			smc_llc_prep_add_link(llc, link,
423 					link->smcibdev->mac[link->ibport - 1],
424 					link->gid, SMC_LLC_REQ);
425 
426 		} else {
427 			smc_llc_prep_add_link(llc, link,
428 					link->smcibdev->mac[link->ibport - 1],
429 					link->gid, SMC_LLC_RESP);
430 		}
431 		smc_llc_send_message(link, llc, sizeof(*llc));
432 	}
433 }
434 
435 static void smc_llc_rx_delete_link(struct smc_link *link,
436 				   struct smc_llc_msg_del_link *llc)
437 {
438 	struct smc_link_group *lgr = smc_get_lgr(link);
439 
440 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
441 		if (lgr->role == SMC_SERV)
442 			smc_lgr_schedule_free_work_fast(lgr);
443 	} else {
444 		smc_lgr_forget(lgr);
445 		smc_llc_link_deleting(link);
446 		if (lgr->role == SMC_SERV) {
447 			/* client asks to delete this link, send request */
448 			smc_llc_prep_delete_link(llc, link, SMC_LLC_REQ, true);
449 		} else {
450 			/* server requests to delete this link, send response */
451 			smc_llc_prep_delete_link(llc, link, SMC_LLC_RESP, true);
452 		}
453 		smc_llc_send_message(link, llc, sizeof(*llc));
454 		smc_lgr_schedule_free_work_fast(lgr);
455 	}
456 }
457 
458 static void smc_llc_rx_test_link(struct smc_link *link,
459 				 struct smc_llc_msg_test_link *llc)
460 {
461 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
462 		if (link->state == SMC_LNK_ACTIVE)
463 			complete(&link->llc_testlink_resp);
464 	} else {
465 		llc->hd.flags |= SMC_LLC_FLAG_RESP;
466 		smc_llc_send_message(link, llc, sizeof(*llc));
467 	}
468 }
469 
470 static void smc_llc_rx_confirm_rkey(struct smc_link *link,
471 				    struct smc_llc_msg_confirm_rkey *llc)
472 {
473 	int rc;
474 
475 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
476 		link->llc_confirm_rkey_rc = llc->hd.flags &
477 					    SMC_LLC_FLAG_RKEY_NEG;
478 		complete(&link->llc_confirm_rkey);
479 	} else {
480 		rc = smc_rtoken_add(smc_get_lgr(link),
481 				    llc->rtoken[0].rmb_vaddr,
482 				    llc->rtoken[0].rmb_key);
483 
484 		/* ignore rtokens for other links, we have only one link */
485 
486 		llc->hd.flags |= SMC_LLC_FLAG_RESP;
487 		if (rc < 0)
488 			llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
489 		smc_llc_send_message(link, llc, sizeof(*llc));
490 	}
491 }
492 
493 static void smc_llc_rx_confirm_rkey_cont(struct smc_link *link,
494 				      struct smc_llc_msg_confirm_rkey_cont *llc)
495 {
496 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
497 		/* unused as long as we don't send this type of msg */
498 	} else {
499 		/* ignore rtokens for other links, we have only one link */
500 		llc->hd.flags |= SMC_LLC_FLAG_RESP;
501 		smc_llc_send_message(link, llc, sizeof(*llc));
502 	}
503 }
504 
505 static void smc_llc_rx_delete_rkey(struct smc_link *link,
506 				   struct smc_llc_msg_delete_rkey *llc)
507 {
508 	u8 err_mask = 0;
509 	int i, max;
510 
511 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
512 		/* unused as long as we don't send this type of msg */
513 	} else {
514 		max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
515 		for (i = 0; i < max; i++) {
516 			if (smc_rtoken_delete(smc_get_lgr(link), llc->rkey[i]))
517 				err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
518 		}
519 
520 		if (err_mask) {
521 			llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
522 			llc->err_mask = err_mask;
523 		}
524 
525 		llc->hd.flags |= SMC_LLC_FLAG_RESP;
526 		smc_llc_send_message(link, llc, sizeof(*llc));
527 	}
528 }
529 
530 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
531 {
532 	struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
533 	union smc_llc_msg *llc = buf;
534 
535 	if (wc->byte_len < sizeof(*llc))
536 		return; /* short message */
537 	if (llc->raw.hdr.length != sizeof(*llc))
538 		return; /* invalid message */
539 	if (link->state == SMC_LNK_INACTIVE)
540 		return; /* link not active, drop msg */
541 
542 	switch (llc->raw.hdr.common.type) {
543 	case SMC_LLC_TEST_LINK:
544 		smc_llc_rx_test_link(link, &llc->test_link);
545 		break;
546 	case SMC_LLC_CONFIRM_LINK:
547 		smc_llc_rx_confirm_link(link, &llc->confirm_link);
548 		break;
549 	case SMC_LLC_ADD_LINK:
550 		smc_llc_rx_add_link(link, &llc->add_link);
551 		break;
552 	case SMC_LLC_DELETE_LINK:
553 		smc_llc_rx_delete_link(link, &llc->delete_link);
554 		break;
555 	case SMC_LLC_CONFIRM_RKEY:
556 		smc_llc_rx_confirm_rkey(link, &llc->confirm_rkey);
557 		break;
558 	case SMC_LLC_CONFIRM_RKEY_CONT:
559 		smc_llc_rx_confirm_rkey_cont(link, &llc->confirm_rkey_cont);
560 		break;
561 	case SMC_LLC_DELETE_RKEY:
562 		smc_llc_rx_delete_rkey(link, &llc->delete_rkey);
563 		break;
564 	}
565 }
566 
567 /***************************** worker, utils *********************************/
568 
569 static void smc_llc_testlink_work(struct work_struct *work)
570 {
571 	struct smc_link *link = container_of(to_delayed_work(work),
572 					     struct smc_link, llc_testlink_wrk);
573 	unsigned long next_interval;
574 	unsigned long expire_time;
575 	u8 user_data[16] = { 0 };
576 	int rc;
577 
578 	if (link->state != SMC_LNK_ACTIVE)
579 		return;		/* don't reschedule worker */
580 	expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
581 	if (time_is_after_jiffies(expire_time)) {
582 		next_interval = expire_time - jiffies;
583 		goto out;
584 	}
585 	reinit_completion(&link->llc_testlink_resp);
586 	smc_llc_send_test_link(link, user_data);
587 	/* receive TEST LINK response over RoCE fabric */
588 	rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
589 						       SMC_LLC_WAIT_TIME);
590 	if (rc <= 0) {
591 		smc_lgr_terminate(smc_get_lgr(link));
592 		return;
593 	}
594 	next_interval = link->llc_testlink_time;
595 out:
596 	queue_delayed_work(link->llc_wq, &link->llc_testlink_wrk,
597 			   next_interval);
598 }
599 
600 int smc_llc_link_init(struct smc_link *link)
601 {
602 	struct smc_link_group *lgr = smc_get_lgr(link);
603 	link->llc_wq = alloc_ordered_workqueue("llc_wq-%x:%x)", WQ_MEM_RECLAIM,
604 					       *((u32 *)lgr->id),
605 					       link->link_id);
606 	if (!link->llc_wq)
607 		return -ENOMEM;
608 	init_completion(&link->llc_confirm);
609 	init_completion(&link->llc_confirm_resp);
610 	init_completion(&link->llc_add);
611 	init_completion(&link->llc_add_resp);
612 	init_completion(&link->llc_confirm_rkey);
613 	init_completion(&link->llc_testlink_resp);
614 	INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
615 	return 0;
616 }
617 
618 void smc_llc_link_active(struct smc_link *link, int testlink_time)
619 {
620 	link->state = SMC_LNK_ACTIVE;
621 	if (testlink_time) {
622 		link->llc_testlink_time = testlink_time * HZ;
623 		queue_delayed_work(link->llc_wq, &link->llc_testlink_wrk,
624 				   link->llc_testlink_time);
625 	}
626 }
627 
628 void smc_llc_link_deleting(struct smc_link *link)
629 {
630 	link->state = SMC_LNK_DELETING;
631 }
632 
633 /* called in tasklet context */
634 void smc_llc_link_inactive(struct smc_link *link)
635 {
636 	link->state = SMC_LNK_INACTIVE;
637 	cancel_delayed_work(&link->llc_testlink_wrk);
638 }
639 
640 /* called in worker context */
641 void smc_llc_link_clear(struct smc_link *link)
642 {
643 	flush_workqueue(link->llc_wq);
644 	destroy_workqueue(link->llc_wq);
645 }
646 
647 /* register a new rtoken at the remote peer */
648 int smc_llc_do_confirm_rkey(struct smc_link *link,
649 			    struct smc_buf_desc *rmb_desc)
650 {
651 	int rc;
652 
653 	reinit_completion(&link->llc_confirm_rkey);
654 	smc_llc_send_confirm_rkey(link, rmb_desc);
655 	/* receive CONFIRM RKEY response from server over RoCE fabric */
656 	rc = wait_for_completion_interruptible_timeout(&link->llc_confirm_rkey,
657 						       SMC_LLC_WAIT_TIME);
658 	if (rc <= 0 || link->llc_confirm_rkey_rc)
659 		return -EFAULT;
660 	return 0;
661 }
662 
663 /***************************** init, exit, misc ******************************/
664 
665 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
666 	{
667 		.handler	= smc_llc_rx_handler,
668 		.type		= SMC_LLC_CONFIRM_LINK
669 	},
670 	{
671 		.handler	= smc_llc_rx_handler,
672 		.type		= SMC_LLC_TEST_LINK
673 	},
674 	{
675 		.handler	= smc_llc_rx_handler,
676 		.type		= SMC_LLC_ADD_LINK
677 	},
678 	{
679 		.handler	= smc_llc_rx_handler,
680 		.type		= SMC_LLC_DELETE_LINK
681 	},
682 	{
683 		.handler	= smc_llc_rx_handler,
684 		.type		= SMC_LLC_CONFIRM_RKEY
685 	},
686 	{
687 		.handler	= smc_llc_rx_handler,
688 		.type		= SMC_LLC_CONFIRM_RKEY_CONT
689 	},
690 	{
691 		.handler	= smc_llc_rx_handler,
692 		.type		= SMC_LLC_DELETE_RKEY
693 	},
694 	{
695 		.handler	= NULL,
696 	}
697 };
698 
699 int __init smc_llc_init(void)
700 {
701 	struct smc_wr_rx_handler *handler;
702 	int rc = 0;
703 
704 	for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
705 		INIT_HLIST_NODE(&handler->list);
706 		rc = smc_wr_rx_register_handler(handler);
707 		if (rc)
708 			break;
709 	}
710 	return rc;
711 }
712