xref: /openbmc/linux/net/smc/smc_core.h (revision ee8ec048)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  Definitions for SMC Connections, Link Groups and Links
6  *
7  *  Copyright IBM Corp. 2016
8  *
9  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
10  */
11 
12 #ifndef _SMC_CORE_H
13 #define _SMC_CORE_H
14 
15 #include <linux/atomic.h>
16 #include <linux/smc.h>
17 #include <linux/pci.h>
18 #include <rdma/ib_verbs.h>
19 #include <net/genetlink.h>
20 
21 #include "smc.h"
22 #include "smc_ib.h"
23 
24 #define SMC_RMBS_PER_LGR_MAX	255	/* max. # of RMBs per link group */
25 
26 struct smc_lgr_list {			/* list of link group definition */
27 	struct list_head	list;
28 	spinlock_t		lock;	/* protects list of link groups */
29 	u32			num;	/* unique link group number */
30 };
31 
32 enum smc_lgr_role {		/* possible roles of a link group */
33 	SMC_CLNT,	/* client */
34 	SMC_SERV	/* server */
35 };
36 
37 enum smc_link_state {			/* possible states of a link */
38 	SMC_LNK_UNUSED,		/* link is unused */
39 	SMC_LNK_INACTIVE,	/* link is inactive */
40 	SMC_LNK_ACTIVATING,	/* link is being activated */
41 	SMC_LNK_ACTIVE,		/* link is active */
42 };
43 
44 #define SMC_WR_BUF_SIZE		48	/* size of work request buffer */
45 #define SMC_WR_BUF_V2_SIZE	8192	/* size of v2 work request buffer */
46 
47 struct smc_wr_buf {
48 	u8	raw[SMC_WR_BUF_SIZE];
49 };
50 
51 struct smc_wr_v2_buf {
52 	u8	raw[SMC_WR_BUF_V2_SIZE];
53 };
54 
55 #define SMC_WR_REG_MR_WAIT_TIME	(5 * HZ)/* wait time for ib_wr_reg_mr result */
56 
57 enum smc_wr_reg_state {
58 	POSTED,		/* ib_wr_reg_mr request posted */
59 	CONFIRMED,	/* ib_wr_reg_mr response: successful */
60 	FAILED		/* ib_wr_reg_mr response: failure */
61 };
62 
63 struct smc_rdma_sge {				/* sges for RDMA writes */
64 	struct ib_sge		wr_tx_rdma_sge[SMC_IB_MAX_SEND_SGE];
65 };
66 
67 #define SMC_MAX_RDMA_WRITES	2		/* max. # of RDMA writes per
68 						 * message send
69 						 */
70 
71 struct smc_rdma_sges {				/* sges per message send */
72 	struct smc_rdma_sge	tx_rdma_sge[SMC_MAX_RDMA_WRITES];
73 };
74 
75 struct smc_rdma_wr {				/* work requests per message
76 						 * send
77 						 */
78 	struct ib_rdma_wr	wr_tx_rdma[SMC_MAX_RDMA_WRITES];
79 };
80 
81 #define SMC_LGR_ID_SIZE		4
82 
83 struct smc_link {
84 	struct smc_ib_device	*smcibdev;	/* ib-device */
85 	u8			ibport;		/* port - values 1 | 2 */
86 	struct ib_pd		*roce_pd;	/* IB protection domain,
87 						 * unique for every RoCE QP
88 						 */
89 	struct ib_qp		*roce_qp;	/* IB queue pair */
90 	struct ib_qp_attr	qp_attr;	/* IB queue pair attributes */
91 
92 	struct smc_wr_buf	*wr_tx_bufs;	/* WR send payload buffers */
93 	struct ib_send_wr	*wr_tx_ibs;	/* WR send meta data */
94 	struct ib_sge		*wr_tx_sges;	/* WR send gather meta data */
95 	struct smc_rdma_sges	*wr_tx_rdma_sges;/*RDMA WRITE gather meta data*/
96 	struct smc_rdma_wr	*wr_tx_rdmas;	/* WR RDMA WRITE */
97 	struct smc_wr_tx_pend	*wr_tx_pends;	/* WR send waiting for CQE */
98 	struct completion	*wr_tx_compl;	/* WR send CQE completion */
99 	/* above four vectors have wr_tx_cnt elements and use the same index */
100 	struct ib_send_wr	*wr_tx_v2_ib;	/* WR send v2 meta data */
101 	struct ib_sge		*wr_tx_v2_sge;	/* WR send v2 gather meta data*/
102 	struct smc_wr_tx_pend	*wr_tx_v2_pend;	/* WR send v2 waiting for CQE */
103 	dma_addr_t		wr_tx_dma_addr;	/* DMA address of wr_tx_bufs */
104 	dma_addr_t		wr_tx_v2_dma_addr; /* DMA address of v2 tx buf*/
105 	atomic_long_t		wr_tx_id;	/* seq # of last sent WR */
106 	unsigned long		*wr_tx_mask;	/* bit mask of used indexes */
107 	u32			wr_tx_cnt;	/* number of WR send buffers */
108 	wait_queue_head_t	wr_tx_wait;	/* wait for free WR send buf */
109 	atomic_t		wr_tx_refcnt;	/* tx refs to link */
110 
111 	struct smc_wr_buf	*wr_rx_bufs;	/* WR recv payload buffers */
112 	struct ib_recv_wr	*wr_rx_ibs;	/* WR recv meta data */
113 	struct ib_sge		*wr_rx_sges;	/* WR recv scatter meta data */
114 	/* above three vectors have wr_rx_cnt elements and use the same index */
115 	dma_addr_t		wr_rx_dma_addr;	/* DMA address of wr_rx_bufs */
116 	dma_addr_t		wr_rx_v2_dma_addr; /* DMA address of v2 rx buf*/
117 	u64			wr_rx_id;	/* seq # of last recv WR */
118 	u32			wr_rx_cnt;	/* number of WR recv buffers */
119 	unsigned long		wr_rx_tstamp;	/* jiffies when last buf rx */
120 
121 	struct ib_reg_wr	wr_reg;		/* WR register memory region */
122 	wait_queue_head_t	wr_reg_wait;	/* wait for wr_reg result */
123 	atomic_t		wr_reg_refcnt;	/* reg refs to link */
124 	enum smc_wr_reg_state	wr_reg_state;	/* state of wr_reg request */
125 
126 	u8			gid[SMC_GID_SIZE];/* gid matching used vlan id*/
127 	u8			sgid_index;	/* gid index for vlan id      */
128 	u32			peer_qpn;	/* QP number of peer */
129 	enum ib_mtu		path_mtu;	/* used mtu */
130 	enum ib_mtu		peer_mtu;	/* mtu size of peer */
131 	u32			psn_initial;	/* QP tx initial packet seqno */
132 	u32			peer_psn;	/* QP rx initial packet seqno */
133 	u8			peer_mac[ETH_ALEN];	/* = gid[8:10||13:15] */
134 	u8			peer_gid[SMC_GID_SIZE];	/* gid of peer*/
135 	u8			link_id;	/* unique # within link group */
136 	u8			link_uid[SMC_LGR_ID_SIZE]; /* unique lnk id */
137 	u8			peer_link_uid[SMC_LGR_ID_SIZE]; /* peer uid */
138 	u8			link_idx;	/* index in lgr link array */
139 	u8			link_is_asym;	/* is link asymmetric? */
140 	struct smc_link_group	*lgr;		/* parent link group */
141 	struct work_struct	link_down_wrk;	/* wrk to bring link down */
142 	char			ibname[IB_DEVICE_NAME_MAX]; /* ib device name */
143 	int			ndev_ifidx; /* network device ifindex */
144 
145 	enum smc_link_state	state;		/* state of link */
146 	struct delayed_work	llc_testlink_wrk; /* testlink worker */
147 	struct completion	llc_testlink_resp; /* wait for rx of testlink */
148 	int			llc_testlink_time; /* testlink interval */
149 	atomic_t		conn_cnt; /* connections on this link */
150 };
151 
152 /* For now we just allow one parallel link per link group. The SMC protocol
153  * allows more (up to 8).
154  */
155 #define SMC_LINKS_PER_LGR_MAX	3
156 #define SMC_SINGLE_LINK		0
157 
158 /* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
159 struct smc_buf_desc {
160 	struct list_head	list;
161 	void			*cpu_addr;	/* virtual address of buffer */
162 	struct page		*pages;
163 	int			len;		/* length of buffer */
164 	u32			used;		/* currently used / unused */
165 	union {
166 		struct { /* SMC-R */
167 			struct sg_table	sgt[SMC_LINKS_PER_LGR_MAX];
168 					/* virtual buffer */
169 			struct ib_mr	*mr_rx[SMC_LINKS_PER_LGR_MAX];
170 					/* for rmb only: memory region
171 					 * incl. rkey provided to peer
172 					 */
173 			u32		order;	/* allocation order */
174 
175 			u8		is_conf_rkey;
176 					/* confirm_rkey done */
177 			u8		is_reg_mr[SMC_LINKS_PER_LGR_MAX];
178 					/* mem region registered */
179 			u8		is_map_ib[SMC_LINKS_PER_LGR_MAX];
180 					/* mem region mapped to lnk */
181 			u8		is_reg_err;
182 					/* buffer registration err */
183 		};
184 		struct { /* SMC-D */
185 			unsigned short	sba_idx;
186 					/* SBA index number */
187 			u64		token;
188 					/* DMB token number */
189 			dma_addr_t	dma_addr;
190 					/* DMA address */
191 		};
192 	};
193 };
194 
195 struct smc_rtoken {				/* address/key of remote RMB */
196 	u64			dma_addr;
197 	u32			rkey;
198 };
199 
200 #define SMC_BUF_MIN_SIZE	16384	/* minimum size of an RMB */
201 #define SMC_RMBE_SIZES		16	/* number of distinct RMBE sizes */
202 /* theoretically, the RFC states that largest size would be 512K,
203  * i.e. compressed 5 and thus 6 sizes (0..5), despite
204  * struct smc_clc_msg_accept_confirm.rmbe_size being a 4 bit value (0..15)
205  */
206 
207 struct smcd_dev;
208 
209 enum smc_lgr_type {				/* redundancy state of lgr */
210 	SMC_LGR_NONE,			/* no active links, lgr to be deleted */
211 	SMC_LGR_SINGLE,			/* 1 active RNIC on each peer */
212 	SMC_LGR_SYMMETRIC,		/* 2 active RNICs on each peer */
213 	SMC_LGR_ASYMMETRIC_PEER,	/* local has 2, peer 1 active RNICs */
214 	SMC_LGR_ASYMMETRIC_LOCAL,	/* local has 1, peer 2 active RNICs */
215 };
216 
217 enum smc_llc_flowtype {
218 	SMC_LLC_FLOW_NONE	= 0,
219 	SMC_LLC_FLOW_ADD_LINK	= 2,
220 	SMC_LLC_FLOW_DEL_LINK	= 4,
221 	SMC_LLC_FLOW_REQ_ADD_LINK = 5,
222 	SMC_LLC_FLOW_RKEY	= 6,
223 };
224 
225 struct smc_llc_qentry;
226 
227 struct smc_llc_flow {
228 	enum smc_llc_flowtype type;
229 	struct smc_llc_qentry *qentry;
230 };
231 
232 struct smc_link_group {
233 	struct list_head	list;
234 	struct rb_root		conns_all;	/* connection tree */
235 	rwlock_t		conns_lock;	/* protects conns_all */
236 	unsigned int		conns_num;	/* current # of connections */
237 	unsigned short		vlan_id;	/* vlan id of link group */
238 
239 	struct list_head	sndbufs[SMC_RMBE_SIZES];/* tx buffers */
240 	struct mutex		sndbufs_lock;	/* protects tx buffers */
241 	struct list_head	rmbs[SMC_RMBE_SIZES];	/* rx buffers */
242 	struct mutex		rmbs_lock;	/* protects rx buffers */
243 
244 	u8			id[SMC_LGR_ID_SIZE];	/* unique lgr id */
245 	struct delayed_work	free_work;	/* delayed freeing of an lgr */
246 	struct work_struct	terminate_work;	/* abnormal lgr termination */
247 	struct workqueue_struct	*tx_wq;		/* wq for conn. tx workers */
248 	u8			sync_err : 1;	/* lgr no longer fits to peer */
249 	u8			terminating : 1;/* lgr is terminating */
250 	u8			freeing : 1;	/* lgr is being freed */
251 
252 	bool			is_smcd;	/* SMC-R or SMC-D */
253 	u8			smc_version;
254 	u8			negotiated_eid[SMC_MAX_EID_LEN];
255 	u8			peer_os;	/* peer operating system */
256 	u8			peer_smc_release;
257 	u8			peer_hostname[SMC_MAX_HOSTNAME_LEN];
258 	union {
259 		struct { /* SMC-R */
260 			enum smc_lgr_role	role;
261 						/* client or server */
262 			struct smc_link		lnk[SMC_LINKS_PER_LGR_MAX];
263 						/* smc link */
264 			struct smc_wr_v2_buf	*wr_rx_buf_v2;
265 						/* WR v2 recv payload buffer */
266 			struct smc_wr_v2_buf	*wr_tx_buf_v2;
267 						/* WR v2 send payload buffer */
268 			char			peer_systemid[SMC_SYSTEMID_LEN];
269 						/* unique system_id of peer */
270 			struct smc_rtoken	rtokens[SMC_RMBS_PER_LGR_MAX]
271 						[SMC_LINKS_PER_LGR_MAX];
272 						/* remote addr/key pairs */
273 			DECLARE_BITMAP(rtokens_used_mask, SMC_RMBS_PER_LGR_MAX);
274 						/* used rtoken elements */
275 			u8			next_link_id;
276 			enum smc_lgr_type	type;
277 						/* redundancy state */
278 			u8			pnet_id[SMC_MAX_PNETID_LEN + 1];
279 						/* pnet id of this lgr */
280 			struct list_head	llc_event_q;
281 						/* queue for llc events */
282 			spinlock_t		llc_event_q_lock;
283 						/* protects llc_event_q */
284 			struct mutex		llc_conf_mutex;
285 						/* protects lgr reconfig. */
286 			struct work_struct	llc_add_link_work;
287 			struct work_struct	llc_del_link_work;
288 			struct work_struct	llc_event_work;
289 						/* llc event worker */
290 			wait_queue_head_t	llc_flow_waiter;
291 						/* w4 next llc event */
292 			wait_queue_head_t	llc_msg_waiter;
293 						/* w4 next llc msg */
294 			struct smc_llc_flow	llc_flow_lcl;
295 						/* llc local control field */
296 			struct smc_llc_flow	llc_flow_rmt;
297 						/* llc remote control field */
298 			struct smc_llc_qentry	*delayed_event;
299 						/* arrived when flow active */
300 			spinlock_t		llc_flow_lock;
301 						/* protects llc flow */
302 			int			llc_testlink_time;
303 						/* link keep alive time */
304 			u32			llc_termination_rsn;
305 						/* rsn code for termination */
306 			u8			nexthop_mac[ETH_ALEN];
307 			u8			uses_gateway;
308 			__be32			saddr;
309 		};
310 		struct { /* SMC-D */
311 			u64			peer_gid;
312 						/* Peer GID (remote) */
313 			struct smcd_dev		*smcd;
314 						/* ISM device for VLAN reg. */
315 			u8			peer_shutdown : 1;
316 						/* peer triggered shutdownn */
317 		};
318 	};
319 };
320 
321 struct smc_clc_msg_local;
322 
323 #define GID_LIST_SIZE	2
324 
325 struct smc_gidlist {
326 	u8			len;
327 	u8			list[GID_LIST_SIZE][SMC_GID_SIZE];
328 };
329 
330 struct smc_init_info_smcrv2 {
331 	/* Input fields */
332 	__be32			saddr;
333 	struct sock		*clc_sk;
334 	__be32			daddr;
335 
336 	/* Output fields when saddr is set */
337 	struct smc_ib_device	*ib_dev_v2;
338 	u8			ib_port_v2;
339 	u8			ib_gid_v2[SMC_GID_SIZE];
340 
341 	/* Additional output fields when clc_sk and daddr is set as well */
342 	u8			uses_gateway;
343 	u8			nexthop_mac[ETH_ALEN];
344 
345 	struct smc_gidlist	gidlist;
346 };
347 
348 struct smc_init_info {
349 	u8			is_smcd;
350 	u8			smc_type_v1;
351 	u8			smc_type_v2;
352 	u8			first_contact_peer;
353 	u8			first_contact_local;
354 	unsigned short		vlan_id;
355 	u32			rc;
356 	u8			negotiated_eid[SMC_MAX_EID_LEN];
357 	/* SMC-R */
358 	u8			smcr_version;
359 	u8			check_smcrv2;
360 	u8			peer_gid[SMC_GID_SIZE];
361 	u8			peer_mac[ETH_ALEN];
362 	u8			peer_systemid[SMC_SYSTEMID_LEN];
363 	struct smc_ib_device	*ib_dev;
364 	u8			ib_gid[SMC_GID_SIZE];
365 	u8			ib_port;
366 	u32			ib_clcqpn;
367 	struct smc_init_info_smcrv2 smcrv2;
368 	/* SMC-D */
369 	u64			ism_peer_gid[SMC_MAX_ISM_DEVS + 1];
370 	struct smcd_dev		*ism_dev[SMC_MAX_ISM_DEVS + 1];
371 	u16			ism_chid[SMC_MAX_ISM_DEVS + 1];
372 	u8			ism_offered_cnt; /* # of ISM devices offered */
373 	u8			ism_selected;    /* index of selected ISM dev*/
374 	u8			smcd_version;
375 };
376 
377 /* Find the connection associated with the given alert token in the link group.
378  * To use rbtrees we have to implement our own search core.
379  * Requires @conns_lock
380  * @token	alert token to search for
381  * @lgr		 link group to search in
382  * Returns connection associated with token if found, NULL otherwise.
383  */
384 static inline struct smc_connection *smc_lgr_find_conn(
385 	u32 token, struct smc_link_group *lgr)
386 {
387 	struct smc_connection *res = NULL;
388 	struct rb_node *node;
389 
390 	node = lgr->conns_all.rb_node;
391 	while (node) {
392 		struct smc_connection *cur = rb_entry(node,
393 					struct smc_connection, alert_node);
394 
395 		if (cur->alert_token_local > token) {
396 			node = node->rb_left;
397 		} else {
398 			if (cur->alert_token_local < token) {
399 				node = node->rb_right;
400 			} else {
401 				res = cur;
402 				break;
403 			}
404 		}
405 	}
406 
407 	return res;
408 }
409 
410 /* returns true if the specified link is usable */
411 static inline bool smc_link_usable(struct smc_link *lnk)
412 {
413 	if (lnk->state == SMC_LNK_UNUSED || lnk->state == SMC_LNK_INACTIVE)
414 		return false;
415 	return true;
416 }
417 
418 static inline bool smc_link_active(struct smc_link *lnk)
419 {
420 	return lnk->state == SMC_LNK_ACTIVE;
421 }
422 
423 static inline void smc_gid_be16_convert(__u8 *buf, u8 *gid_raw)
424 {
425 	sprintf(buf, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x",
426 		be16_to_cpu(((__be16 *)gid_raw)[0]),
427 		be16_to_cpu(((__be16 *)gid_raw)[1]),
428 		be16_to_cpu(((__be16 *)gid_raw)[2]),
429 		be16_to_cpu(((__be16 *)gid_raw)[3]),
430 		be16_to_cpu(((__be16 *)gid_raw)[4]),
431 		be16_to_cpu(((__be16 *)gid_raw)[5]),
432 		be16_to_cpu(((__be16 *)gid_raw)[6]),
433 		be16_to_cpu(((__be16 *)gid_raw)[7]));
434 }
435 
436 struct smc_pci_dev {
437 	__u32		pci_fid;
438 	__u16		pci_pchid;
439 	__u16		pci_vendor;
440 	__u16		pci_device;
441 	__u8		pci_id[SMC_PCI_ID_STR_LEN];
442 };
443 
444 static inline void smc_set_pci_values(struct pci_dev *pci_dev,
445 				      struct smc_pci_dev *smc_dev)
446 {
447 	smc_dev->pci_vendor = pci_dev->vendor;
448 	smc_dev->pci_device = pci_dev->device;
449 	snprintf(smc_dev->pci_id, sizeof(smc_dev->pci_id), "%s",
450 		 pci_name(pci_dev));
451 #if IS_ENABLED(CONFIG_S390)
452 	{ /* Set s390 specific PCI information */
453 	struct zpci_dev *zdev;
454 
455 	zdev = to_zpci(pci_dev);
456 	smc_dev->pci_fid = zdev->fid;
457 	smc_dev->pci_pchid = zdev->pchid;
458 	}
459 #endif
460 }
461 
462 struct smc_sock;
463 struct smc_clc_msg_accept_confirm;
464 
465 void smc_lgr_cleanup_early(struct smc_connection *conn);
466 void smc_lgr_terminate_sched(struct smc_link_group *lgr);
467 void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport);
468 void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport);
469 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid,
470 			unsigned short vlan);
471 void smc_smcd_terminate_all(struct smcd_dev *dev);
472 void smc_smcr_terminate_all(struct smc_ib_device *smcibdev);
473 int smc_buf_create(struct smc_sock *smc, bool is_smcd);
474 int smc_uncompress_bufsize(u8 compressed);
475 int smc_rmb_rtoken_handling(struct smc_connection *conn, struct smc_link *link,
476 			    struct smc_clc_msg_accept_confirm *clc);
477 int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey);
478 int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey);
479 void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
480 		    __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey);
481 void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
482 		     __be64 nw_vaddr, __be32 nw_rkey);
483 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn);
484 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn);
485 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn);
486 void smc_rmb_sync_sg_for_device(struct smc_connection *conn);
487 int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini);
488 
489 void smc_conn_free(struct smc_connection *conn);
490 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini);
491 void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr);
492 int smc_core_init(void);
493 void smc_core_exit(void);
494 
495 int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
496 		   u8 link_idx, struct smc_init_info *ini);
497 void smcr_link_clear(struct smc_link *lnk, bool log);
498 void smc_switch_link_and_count(struct smc_connection *conn,
499 			       struct smc_link *to_lnk);
500 int smcr_buf_map_lgr(struct smc_link *lnk);
501 int smcr_buf_reg_lgr(struct smc_link *lnk);
502 void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type);
503 void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
504 			    enum smc_lgr_type new_type, int asym_lnk_idx);
505 int smcr_link_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc);
506 struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
507 				  struct smc_link *from_lnk, bool is_dev_err);
508 void smcr_link_down_cond(struct smc_link *lnk);
509 void smcr_link_down_cond_sched(struct smc_link *lnk);
510 int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb);
511 int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb);
512 int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb);
513 int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb);
514 
515 static inline struct smc_link_group *smc_get_lgr(struct smc_link *link)
516 {
517 	return link->lgr;
518 }
519 #endif
520