xref: /linux/net/smc/smc_core.h (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
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 
23 struct smc_lgr_list {			/* list of link group definition */
24 	struct list_head	list;
25 	spinlock_t		lock;	/* protects list of link groups */
26 };
27 
28 extern struct smc_lgr_list	smc_lgr_list; /* list of link groups */
29 
30 enum smc_lgr_role {		/* possible roles of a link group */
31 	SMC_CLNT,	/* client */
32 	SMC_SERV	/* server */
33 };
34 
35 #define SMC_WR_BUF_SIZE		48	/* size of work request buffer */
36 
37 struct smc_wr_buf {
38 	u8	raw[SMC_WR_BUF_SIZE];
39 };
40 
41 #define SMC_WR_REG_MR_WAIT_TIME	(5 * HZ)/* wait time for ib_wr_reg_mr result */
42 
43 enum smc_wr_reg_state {
44 	POSTED,		/* ib_wr_reg_mr request posted */
45 	CONFIRMED,	/* ib_wr_reg_mr response: successful */
46 	FAILED		/* ib_wr_reg_mr response: failure */
47 };
48 
49 struct smc_link {
50 	struct smc_ib_device	*smcibdev;	/* ib-device */
51 	u8			ibport;		/* port - values 1 | 2 */
52 	struct ib_pd		*roce_pd;	/* IB protection domain,
53 						 * unique for every RoCE QP
54 						 */
55 	struct ib_qp		*roce_qp;	/* IB queue pair */
56 	struct ib_qp_attr	qp_attr;	/* IB queue pair attributes */
57 
58 	struct smc_wr_buf	*wr_tx_bufs;	/* WR send payload buffers */
59 	struct ib_send_wr	*wr_tx_ibs;	/* WR send meta data */
60 	struct ib_sge		*wr_tx_sges;	/* WR send gather meta data */
61 	struct smc_wr_tx_pend	*wr_tx_pends;	/* WR send waiting for CQE */
62 	/* above four vectors have wr_tx_cnt elements and use the same index */
63 	dma_addr_t		wr_tx_dma_addr;	/* DMA address of wr_tx_bufs */
64 	atomic_long_t		wr_tx_id;	/* seq # of last sent WR */
65 	unsigned long		*wr_tx_mask;	/* bit mask of used indexes */
66 	u32			wr_tx_cnt;	/* number of WR send buffers */
67 	wait_queue_head_t	wr_tx_wait;	/* wait for free WR send buf */
68 
69 	struct smc_wr_buf	*wr_rx_bufs;	/* WR recv payload buffers */
70 	struct ib_recv_wr	*wr_rx_ibs;	/* WR recv meta data */
71 	struct ib_sge		*wr_rx_sges;	/* WR recv scatter meta data */
72 	/* above three vectors have wr_rx_cnt elements and use the same index */
73 	dma_addr_t		wr_rx_dma_addr;	/* DMA address of wr_rx_bufs */
74 	u64			wr_rx_id;	/* seq # of last recv WR */
75 	u32			wr_rx_cnt;	/* number of WR recv buffers */
76 
77 	struct ib_reg_wr	wr_reg;		/* WR register memory region */
78 	wait_queue_head_t	wr_reg_wait;	/* wait for wr_reg result */
79 	enum smc_wr_reg_state	wr_reg_state;	/* state of wr_reg request */
80 
81 	union ib_gid		gid;		/* gid matching used vlan id */
82 	u32			peer_qpn;	/* QP number of peer */
83 	enum ib_mtu		path_mtu;	/* used mtu */
84 	enum ib_mtu		peer_mtu;	/* mtu size of peer */
85 	u32			psn_initial;	/* QP tx initial packet seqno */
86 	u32			peer_psn;	/* QP rx initial packet seqno */
87 	u8			peer_mac[ETH_ALEN];	/* = gid[8:10||13:15] */
88 	u8			peer_gid[sizeof(union ib_gid)];	/* gid of peer*/
89 	u8			link_id;	/* unique # within link group */
90 	struct completion	llc_confirm;	/* wait for rx of conf link */
91 	struct completion	llc_confirm_resp; /* wait 4 rx of cnf lnk rsp */
92 };
93 
94 /* For now we just allow one parallel link per link group. The SMC protocol
95  * allows more (up to 8).
96  */
97 #define SMC_LINKS_PER_LGR_MAX	1
98 #define SMC_SINGLE_LINK		0
99 
100 #define SMC_FIRST_CONTACT	1		/* first contact to a peer */
101 #define SMC_REUSE_CONTACT	0		/* follow-on contact to a peer*/
102 
103 /* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
104 struct smc_buf_desc {
105 	struct list_head	list;
106 	void			*cpu_addr;	/* virtual address of buffer */
107 	struct sg_table		sgt[SMC_LINKS_PER_LGR_MAX];/* virtual buffer */
108 	struct ib_mr		*mr_rx[SMC_LINKS_PER_LGR_MAX];
109 						/* for rmb only: memory region
110 						 * incl. rkey provided to peer
111 						 */
112 	u32			order;		/* allocation order */
113 	u32			used;		/* currently used / unused */
114 	bool			reused;		/* new created / reused */
115 };
116 
117 struct smc_rtoken {				/* address/key of remote RMB */
118 	u64			dma_addr;
119 	u32			rkey;
120 };
121 
122 #define SMC_LGR_ID_SIZE		4
123 
124 struct smc_link_group {
125 	struct list_head	list;
126 	enum smc_lgr_role	role;		/* client or server */
127 	__be32			daddr;		/* destination ip address */
128 	struct smc_link		lnk[SMC_LINKS_PER_LGR_MAX];	/* smc link */
129 	char			peer_systemid[SMC_SYSTEMID_LEN];
130 						/* unique system_id of peer */
131 	struct rb_root		conns_all;	/* connection tree */
132 	rwlock_t		conns_lock;	/* protects conns_all */
133 	unsigned int		conns_num;	/* current # of connections */
134 	unsigned short		vlan_id;	/* vlan id of link group */
135 
136 	struct list_head	sndbufs[SMC_RMBE_SIZES];/* tx buffers */
137 	rwlock_t		sndbufs_lock;	/* protects tx buffers */
138 	struct list_head	rmbs[SMC_RMBE_SIZES];	/* rx buffers */
139 	rwlock_t		rmbs_lock;	/* protects rx buffers */
140 	struct smc_rtoken	rtokens[SMC_RMBS_PER_LGR_MAX]
141 				       [SMC_LINKS_PER_LGR_MAX];
142 						/* remote addr/key pairs */
143 	unsigned long		rtokens_used_mask[BITS_TO_LONGS(
144 							SMC_RMBS_PER_LGR_MAX)];
145 						/* used rtoken elements */
146 
147 	u8			id[SMC_LGR_ID_SIZE];	/* unique lgr id */
148 	struct delayed_work	free_work;	/* delayed freeing of an lgr */
149 	bool			sync_err;	/* lgr no longer fits to peer */
150 };
151 
152 /* Find the connection associated with the given alert token in the link group.
153  * To use rbtrees we have to implement our own search core.
154  * Requires @conns_lock
155  * @token	alert token to search for
156  * @lgr		 link group to search in
157  * Returns connection associated with token if found, NULL otherwise.
158  */
159 static inline struct smc_connection *smc_lgr_find_conn(
160 	u32 token, struct smc_link_group *lgr)
161 {
162 	struct smc_connection *res = NULL;
163 	struct rb_node *node;
164 
165 	node = lgr->conns_all.rb_node;
166 	while (node) {
167 		struct smc_connection *cur = rb_entry(node,
168 					struct smc_connection, alert_node);
169 
170 		if (cur->alert_token_local > token) {
171 			node = node->rb_left;
172 		} else {
173 			if (cur->alert_token_local < token) {
174 				node = node->rb_right;
175 			} else {
176 				res = cur;
177 				break;
178 			}
179 		}
180 	}
181 
182 	return res;
183 }
184 
185 struct smc_sock;
186 struct smc_clc_msg_accept_confirm;
187 
188 void smc_lgr_free(struct smc_link_group *lgr);
189 void smc_lgr_terminate(struct smc_link_group *lgr);
190 int smc_buf_create(struct smc_sock *smc);
191 int smc_rmb_rtoken_handling(struct smc_connection *conn,
192 			    struct smc_clc_msg_accept_confirm *clc);
193 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn);
194 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn);
195 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn);
196 void smc_rmb_sync_sg_for_device(struct smc_connection *conn);
197 #endif
198