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  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 <rdma/ib_verbs.h>
 17
 18#include "smc.h"
 19#include "smc_ib.h"
 20
 21#define SMC_RMBS_PER_LGR_MAX	255	/* max. # of RMBs per link group */
 22
 23struct smc_lgr_list {			/* list of link group definition */
 24	struct list_head	list;
 25	spinlock_t		lock;	/* protects list of link groups */
 26	u32			num;	/* unique link group number */
 27};
 28
 29enum smc_lgr_role {		/* possible roles of a link group */
 30	SMC_CLNT,	/* client */
 31	SMC_SERV	/* server */
 32};
 33
 34enum smc_link_state {			/* possible states of a link */
 35	SMC_LNK_UNUSED,		/* link is unused */
 36	SMC_LNK_INACTIVE,	/* link is inactive */
 37	SMC_LNK_ACTIVATING,	/* link is being activated */
 38	SMC_LNK_ACTIVE,		/* link is active */
 39};
 40
 41#define SMC_WR_BUF_SIZE		48	/* size of work request buffer */
 42
 43struct smc_wr_buf {
 44	u8	raw[SMC_WR_BUF_SIZE];
 45};
 46
 47#define SMC_WR_REG_MR_WAIT_TIME	(5 * HZ)/* wait time for ib_wr_reg_mr result */
 48
 49enum smc_wr_reg_state {
 50	POSTED,		/* ib_wr_reg_mr request posted */
 51	CONFIRMED,	/* ib_wr_reg_mr response: successful */
 52	FAILED		/* ib_wr_reg_mr response: failure */
 53};
 54
 55struct smc_rdma_sge {				/* sges for RDMA writes */
 56	struct ib_sge		wr_tx_rdma_sge[SMC_IB_MAX_SEND_SGE];
 57};
 58
 59#define SMC_MAX_RDMA_WRITES	2		/* max. # of RDMA writes per
 60						 * message send
 61						 */
 62
 63struct smc_rdma_sges {				/* sges per message send */
 64	struct smc_rdma_sge	tx_rdma_sge[SMC_MAX_RDMA_WRITES];
 65};
 66
 67struct smc_rdma_wr {				/* work requests per message
 68						 * send
 69						 */
 70	struct ib_rdma_wr	wr_tx_rdma[SMC_MAX_RDMA_WRITES];
 71};
 72
 73#define SMC_LGR_ID_SIZE		4
 74
 75struct smc_link {
 76	struct smc_ib_device	*smcibdev;	/* ib-device */
 77	u8			ibport;		/* port - values 1 | 2 */
 78	struct ib_pd		*roce_pd;	/* IB protection domain,
 79						 * unique for every RoCE QP
 80						 */
 81	struct ib_qp		*roce_qp;	/* IB queue pair */
 82	struct ib_qp_attr	qp_attr;	/* IB queue pair attributes */
 83
 84	struct smc_wr_buf	*wr_tx_bufs;	/* WR send payload buffers */
 85	struct ib_send_wr	*wr_tx_ibs;	/* WR send meta data */
 86	struct ib_sge		*wr_tx_sges;	/* WR send gather meta data */
 87	struct smc_rdma_sges	*wr_tx_rdma_sges;/*RDMA WRITE gather meta data*/
 88	struct smc_rdma_wr	*wr_tx_rdmas;	/* WR RDMA WRITE */
 89	struct smc_wr_tx_pend	*wr_tx_pends;	/* WR send waiting for CQE */
 90	struct completion	*wr_tx_compl;	/* WR send CQE completion */
 91	/* above four vectors have wr_tx_cnt elements and use the same index */
 92	dma_addr_t		wr_tx_dma_addr;	/* DMA address of wr_tx_bufs */
 93	atomic_long_t		wr_tx_id;	/* seq # of last sent WR */
 94	unsigned long		*wr_tx_mask;	/* bit mask of used indexes */
 95	u32			wr_tx_cnt;	/* number of WR send buffers */
 96	wait_queue_head_t	wr_tx_wait;	/* wait for free WR send buf */
 97
 98	struct smc_wr_buf	*wr_rx_bufs;	/* WR recv payload buffers */
 99	struct ib_recv_wr	*wr_rx_ibs;	/* WR recv meta data */
100	struct ib_sge		*wr_rx_sges;	/* WR recv scatter meta data */
101	/* above three vectors have wr_rx_cnt elements and use the same index */
102	dma_addr_t		wr_rx_dma_addr;	/* DMA address of wr_rx_bufs */
103	u64			wr_rx_id;	/* seq # of last recv WR */
104	u32			wr_rx_cnt;	/* number of WR recv buffers */
105	unsigned long		wr_rx_tstamp;	/* jiffies when last buf rx */
106
107	struct ib_reg_wr	wr_reg;		/* WR register memory region */
108	wait_queue_head_t	wr_reg_wait;	/* wait for wr_reg result */
109	enum smc_wr_reg_state	wr_reg_state;	/* state of wr_reg request */
110
111	u8			gid[SMC_GID_SIZE];/* gid matching used vlan id*/
112	u8			sgid_index;	/* gid index for vlan id      */
113	u32			peer_qpn;	/* QP number of peer */
114	enum ib_mtu		path_mtu;	/* used mtu */
115	enum ib_mtu		peer_mtu;	/* mtu size of peer */
116	u32			psn_initial;	/* QP tx initial packet seqno */
117	u32			peer_psn;	/* QP rx initial packet seqno */
118	u8			peer_mac[ETH_ALEN];	/* = gid[8:10||13:15] */
119	u8			peer_gid[SMC_GID_SIZE];	/* gid of peer*/
120	u8			link_id;	/* unique # within link group */
121	u8			link_uid[SMC_LGR_ID_SIZE]; /* unique lnk id */
122	u8			peer_link_uid[SMC_LGR_ID_SIZE]; /* peer uid */
123	u8			link_idx;	/* index in lgr link array */
124	u8			link_is_asym;	/* is link asymmetric? */
125	struct smc_link_group	*lgr;		/* parent link group */
126	struct work_struct	link_down_wrk;	/* wrk to bring link down */
127
128	enum smc_link_state	state;		/* state of link */
129	struct delayed_work	llc_testlink_wrk; /* testlink worker */
130	struct completion	llc_testlink_resp; /* wait for rx of testlink */
131	int			llc_testlink_time; /* testlink interval */
132};
133
134/* For now we just allow one parallel link per link group. The SMC protocol
135 * allows more (up to 8).
136 */
137#define SMC_LINKS_PER_LGR_MAX	3
138#define SMC_SINGLE_LINK		0
139
140#define SMC_FIRST_CONTACT	1		/* first contact to a peer */
141#define SMC_REUSE_CONTACT	0		/* follow-on contact to a peer*/
142
143/* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
144struct smc_buf_desc {
145	struct list_head	list;
146	void			*cpu_addr;	/* virtual address of buffer */
147	struct page		*pages;
148	int			len;		/* length of buffer */
149	u32			used;		/* currently used / unused */
150	union {
151		struct { /* SMC-R */
152			struct sg_table	sgt[SMC_LINKS_PER_LGR_MAX];
153					/* virtual buffer */
154			struct ib_mr	*mr_rx[SMC_LINKS_PER_LGR_MAX];
155					/* for rmb only: memory region
156					 * incl. rkey provided to peer
157					 */
158			u32		order;	/* allocation order */
159
160			u8		is_conf_rkey;
161					/* confirm_rkey done */
162			u8		is_reg_mr[SMC_LINKS_PER_LGR_MAX];
163					/* mem region registered */
164			u8		is_map_ib[SMC_LINKS_PER_LGR_MAX];
165					/* mem region mapped to lnk */
166			u8		is_reg_err;
167					/* buffer registration err */
168		};
169		struct { /* SMC-D */
170			unsigned short	sba_idx;
171					/* SBA index number */
172			u64		token;
173					/* DMB token number */
174			dma_addr_t	dma_addr;
175					/* DMA address */
176		};
177	};
178};
179
180struct smc_rtoken {				/* address/key of remote RMB */
181	u64			dma_addr;
182	u32			rkey;
183};
184
185#define SMC_BUF_MIN_SIZE	16384	/* minimum size of an RMB */
186#define SMC_RMBE_SIZES		16	/* number of distinct RMBE sizes */
187/* theoretically, the RFC states that largest size would be 512K,
188 * i.e. compressed 5 and thus 6 sizes (0..5), despite
189 * struct smc_clc_msg_accept_confirm.rmbe_size being a 4 bit value (0..15)
190 */
191
192struct smcd_dev;
193
194enum smc_lgr_type {				/* redundancy state of lgr */
195	SMC_LGR_NONE,			/* no active links, lgr to be deleted */
196	SMC_LGR_SINGLE,			/* 1 active RNIC on each peer */
197	SMC_LGR_SYMMETRIC,		/* 2 active RNICs on each peer */
198	SMC_LGR_ASYMMETRIC_PEER,	/* local has 2, peer 1 active RNICs */
199	SMC_LGR_ASYMMETRIC_LOCAL,	/* local has 1, peer 2 active RNICs */
200};
201
202enum smc_llc_flowtype {
203	SMC_LLC_FLOW_NONE	= 0,
204	SMC_LLC_FLOW_ADD_LINK	= 2,
205	SMC_LLC_FLOW_DEL_LINK	= 4,
206	SMC_LLC_FLOW_RKEY	= 6,
207};
208
209struct smc_llc_qentry;
210
211struct smc_llc_flow {
212	enum smc_llc_flowtype type;
213	struct smc_llc_qentry *qentry;
214};
215
216struct smc_link_group {
217	struct list_head	list;
218	struct rb_root		conns_all;	/* connection tree */
219	rwlock_t		conns_lock;	/* protects conns_all */
220	unsigned int		conns_num;	/* current # of connections */
221	unsigned short		vlan_id;	/* vlan id of link group */
222
223	struct list_head	sndbufs[SMC_RMBE_SIZES];/* tx buffers */
224	struct mutex		sndbufs_lock;	/* protects tx buffers */
225	struct list_head	rmbs[SMC_RMBE_SIZES];	/* rx buffers */
226	struct mutex		rmbs_lock;	/* protects rx buffers */
227
228	u8			id[SMC_LGR_ID_SIZE];	/* unique lgr id */
229	struct delayed_work	free_work;	/* delayed freeing of an lgr */
230	struct work_struct	terminate_work;	/* abnormal lgr termination */
231	u8			sync_err : 1;	/* lgr no longer fits to peer */
232	u8			terminating : 1;/* lgr is terminating */
233	u8			freefast : 1;	/* free worker scheduled fast */
234	u8			freeing : 1;	/* lgr is being freed */
235
236	bool			is_smcd;	/* SMC-R or SMC-D */
237	union {
238		struct { /* SMC-R */
239			enum smc_lgr_role	role;
240						/* client or server */
241			struct smc_link		lnk[SMC_LINKS_PER_LGR_MAX];
242						/* smc link */
243			char			peer_systemid[SMC_SYSTEMID_LEN];
244						/* unique system_id of peer */
245			struct smc_rtoken	rtokens[SMC_RMBS_PER_LGR_MAX]
246						[SMC_LINKS_PER_LGR_MAX];
247						/* remote addr/key pairs */
248			DECLARE_BITMAP(rtokens_used_mask, SMC_RMBS_PER_LGR_MAX);
249						/* used rtoken elements */
250			u8			next_link_id;
251			enum smc_lgr_type	type;
252						/* redundancy state */
253			u8			pnet_id[SMC_MAX_PNETID_LEN + 1];
254						/* pnet id of this lgr */
255			struct list_head	llc_event_q;
256						/* queue for llc events */
257			spinlock_t		llc_event_q_lock;
258						/* protects llc_event_q */
259			struct mutex		llc_conf_mutex;
260						/* protects lgr reconfig. */
261			struct work_struct	llc_add_link_work;
262			struct work_struct	llc_del_link_work;
263			struct work_struct	llc_event_work;
264						/* llc event worker */
265			wait_queue_head_t	llc_flow_waiter;
266						/* w4 next llc event */
267			wait_queue_head_t	llc_msg_waiter;
268						/* w4 next llc msg */
269			struct smc_llc_flow	llc_flow_lcl;
270						/* llc local control field */
271			struct smc_llc_flow	llc_flow_rmt;
272						/* llc remote control field */
273			struct smc_llc_qentry	*delayed_event;
274						/* arrived when flow active */
275			spinlock_t		llc_flow_lock;
276						/* protects llc flow */
277			int			llc_testlink_time;
278						/* link keep alive time */
279			u32			llc_termination_rsn;
280						/* rsn code for termination */
281		};
282		struct { /* SMC-D */
283			u64			peer_gid;
284						/* Peer GID (remote) */
285			struct smcd_dev		*smcd;
286						/* ISM device for VLAN reg. */
287			u8			peer_shutdown : 1;
288						/* peer triggered shutdownn */
289		};
290	};
291};
292
293struct smc_clc_msg_local;
294
295struct smc_init_info {
296	u8			is_smcd;
297	unsigned short		vlan_id;
298	int			srv_first_contact;
299	int			cln_first_contact;
300	/* SMC-R */
301	struct smc_clc_msg_local *ib_lcl;
302	struct smc_ib_device	*ib_dev;
303	u8			ib_gid[SMC_GID_SIZE];
304	u8			ib_port;
305	u32			ib_clcqpn;
306	/* SMC-D */
307	u64			ism_gid;
308	struct smcd_dev		*ism_dev;
309};
310
311/* Find the connection associated with the given alert token in the link group.
312 * To use rbtrees we have to implement our own search core.
313 * Requires @conns_lock
314 * @token	alert token to search for
315 * @lgr		 link group to search in
316 * Returns connection associated with token if found, NULL otherwise.
317 */
318static inline struct smc_connection *smc_lgr_find_conn(
319	u32 token, struct smc_link_group *lgr)
320{
321	struct smc_connection *res = NULL;
322	struct rb_node *node;
323
324	node = lgr->conns_all.rb_node;
325	while (node) {
326		struct smc_connection *cur = rb_entry(node,
327					struct smc_connection, alert_node);
328
329		if (cur->alert_token_local > token) {
330			node = node->rb_left;
331		} else {
332			if (cur->alert_token_local < token) {
333				node = node->rb_right;
334			} else {
335				res = cur;
336				break;
337			}
338		}
339	}
340
341	return res;
342}
343
344/* returns true if the specified link is usable */
345static inline bool smc_link_usable(struct smc_link *lnk)
346{
347	if (lnk->state == SMC_LNK_UNUSED || lnk->state == SMC_LNK_INACTIVE)
348		return false;
349	return true;
350}
351
352static inline bool smc_link_active(struct smc_link *lnk)
353{
354	return lnk->state == SMC_LNK_ACTIVE;
355}
356
357struct smc_sock;
358struct smc_clc_msg_accept_confirm;
359struct smc_clc_msg_local;
360
361void smc_lgr_cleanup_early(struct smc_connection *conn);
362void smc_lgr_terminate_sched(struct smc_link_group *lgr);
363void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport);
364void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport);
365void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid,
366			unsigned short vlan);
367void smc_smcd_terminate_all(struct smcd_dev *dev);
368void smc_smcr_terminate_all(struct smc_ib_device *smcibdev);
369int smc_buf_create(struct smc_sock *smc, bool is_smcd);
370int smc_uncompress_bufsize(u8 compressed);
371int smc_rmb_rtoken_handling(struct smc_connection *conn, struct smc_link *link,
372			    struct smc_clc_msg_accept_confirm *clc);
373int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey);
374int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey);
375void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
376		    __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey);
377void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
378		     __be64 nw_vaddr, __be32 nw_rkey);
379void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn);
380void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn);
381void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn);
382void smc_rmb_sync_sg_for_device(struct smc_connection *conn);
383int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini);
384
385void smc_conn_free(struct smc_connection *conn);
386int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini);
387void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr);
388int smc_core_init(void);
389void smc_core_exit(void);
390
391int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
392		   u8 link_idx, struct smc_init_info *ini);
393void smcr_link_clear(struct smc_link *lnk, bool log);
394int smcr_buf_map_lgr(struct smc_link *lnk);
395int smcr_buf_reg_lgr(struct smc_link *lnk);
396void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type);
397void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
398			    enum smc_lgr_type new_type, int asym_lnk_idx);
399int smcr_link_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc);
400struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
401				  struct smc_link *from_lnk, bool is_dev_err);
402void smcr_link_down_cond(struct smc_link *lnk);
403void smcr_link_down_cond_sched(struct smc_link *lnk);
404
405static inline struct smc_link_group *smc_get_lgr(struct smc_link *link)
406{
407	return link->lgr;
408}
409#endif