xref: /openbmc/linux/net/smc/smc_core.h (revision 174cd4b1)
1 /*
2  * Shared Memory Communications over RDMA (SMC-R) and RoCE
3  *
4  *  Definitions for SMC Connections, Link Groups and Links
5  *
6  *  Copyright IBM Corp. 2016
7  *
8  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
9  */
10 
11 #ifndef _SMC_CORE_H
12 #define _SMC_CORE_H
13 
14 #include <linux/atomic.h>
15 #include <rdma/ib_verbs.h>
16 
17 #include "smc.h"
18 #include "smc_ib.h"
19 
20 #define SMC_RMBS_PER_LGR_MAX	255	/* max. # of RMBs per link group */
21 
22 struct smc_lgr_list {			/* list of link group definition */
23 	struct list_head	list;
24 	spinlock_t		lock;	/* protects list of link groups */
25 };
26 
27 extern struct smc_lgr_list	smc_lgr_list; /* list of link groups */
28 
29 enum smc_lgr_role {		/* possible roles of a link group */
30 	SMC_CLNT,	/* client */
31 	SMC_SERV	/* server */
32 };
33 
34 #define SMC_WR_BUF_SIZE		48	/* size of work request buffer */
35 
36 struct smc_wr_buf {
37 	u8	raw[SMC_WR_BUF_SIZE];
38 };
39 
40 struct smc_link {
41 	struct smc_ib_device	*smcibdev;	/* ib-device */
42 	u8			ibport;		/* port - values 1 | 2 */
43 	struct ib_pd		*roce_pd;	/* IB protection domain,
44 						 * unique for every RoCE QP
45 						 */
46 	struct ib_qp		*roce_qp;	/* IB queue pair */
47 	struct ib_qp_attr	qp_attr;	/* IB queue pair attributes */
48 
49 	struct smc_wr_buf	*wr_tx_bufs;	/* WR send payload buffers */
50 	struct ib_send_wr	*wr_tx_ibs;	/* WR send meta data */
51 	struct ib_sge		*wr_tx_sges;	/* WR send gather meta data */
52 	struct smc_wr_tx_pend	*wr_tx_pends;	/* WR send waiting for CQE */
53 	/* above four vectors have wr_tx_cnt elements and use the same index */
54 	dma_addr_t		wr_tx_dma_addr;	/* DMA address of wr_tx_bufs */
55 	atomic_long_t		wr_tx_id;	/* seq # of last sent WR */
56 	unsigned long		*wr_tx_mask;	/* bit mask of used indexes */
57 	u32			wr_tx_cnt;	/* number of WR send buffers */
58 	wait_queue_head_t	wr_tx_wait;	/* wait for free WR send buf */
59 
60 	struct smc_wr_buf	*wr_rx_bufs;	/* WR recv payload buffers */
61 	struct ib_recv_wr	*wr_rx_ibs;	/* WR recv meta data */
62 	struct ib_sge		*wr_rx_sges;	/* WR recv scatter meta data */
63 	/* above three vectors have wr_rx_cnt elements and use the same index */
64 	dma_addr_t		wr_rx_dma_addr;	/* DMA address of wr_rx_bufs */
65 	u64			wr_rx_id;	/* seq # of last recv WR */
66 	u32			wr_rx_cnt;	/* number of WR recv buffers */
67 
68 	union ib_gid		gid;		/* gid matching used vlan id */
69 	u32			peer_qpn;	/* QP number of peer */
70 	enum ib_mtu		path_mtu;	/* used mtu */
71 	enum ib_mtu		peer_mtu;	/* mtu size of peer */
72 	u32			psn_initial;	/* QP tx initial packet seqno */
73 	u32			peer_psn;	/* QP rx initial packet seqno */
74 	u8			peer_mac[ETH_ALEN];	/* = gid[8:10||13:15] */
75 	u8			peer_gid[sizeof(union ib_gid)];	/* gid of peer*/
76 	u8			link_id;	/* unique # within link group */
77 	struct completion	llc_confirm;	/* wait for rx of conf link */
78 	struct completion	llc_confirm_resp; /* wait 4 rx of cnf lnk rsp */
79 };
80 
81 /* For now we just allow one parallel link per link group. The SMC protocol
82  * allows more (up to 8).
83  */
84 #define SMC_LINKS_PER_LGR_MAX	1
85 #define SMC_SINGLE_LINK		0
86 
87 #define SMC_FIRST_CONTACT	1		/* first contact to a peer */
88 #define SMC_REUSE_CONTACT	0		/* follow-on contact to a peer*/
89 
90 /* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
91 struct smc_buf_desc {
92 	struct list_head	list;
93 	u64			dma_addr[SMC_LINKS_PER_LGR_MAX];
94 						/* mapped address of buffer */
95 	void			*cpu_addr;	/* virtual address of buffer */
96 	struct ib_mr		*mr_rx[SMC_LINKS_PER_LGR_MAX];
97 						/* for rmb only:
98 						 * rkey provided to peer
99 						 */
100 	u32			used;		/* currently used / unused */
101 };
102 
103 struct smc_rtoken {				/* address/key of remote RMB */
104 	u64			dma_addr;
105 	u32			rkey;
106 };
107 
108 #define SMC_LGR_ID_SIZE		4
109 
110 struct smc_link_group {
111 	struct list_head	list;
112 	enum smc_lgr_role	role;		/* client or server */
113 	__be32			daddr;		/* destination ip address */
114 	struct smc_link		lnk[SMC_LINKS_PER_LGR_MAX];	/* smc link */
115 	char			peer_systemid[SMC_SYSTEMID_LEN];
116 						/* unique system_id of peer */
117 	struct rb_root		conns_all;	/* connection tree */
118 	rwlock_t		conns_lock;	/* protects conns_all */
119 	unsigned int		conns_num;	/* current # of connections */
120 	unsigned short		vlan_id;	/* vlan id of link group */
121 
122 	struct list_head	sndbufs[SMC_RMBE_SIZES];/* tx buffers */
123 	rwlock_t		sndbufs_lock;	/* protects tx buffers */
124 	struct list_head	rmbs[SMC_RMBE_SIZES];	/* rx buffers */
125 	rwlock_t		rmbs_lock;	/* protects rx buffers */
126 	struct smc_rtoken	rtokens[SMC_RMBS_PER_LGR_MAX]
127 				       [SMC_LINKS_PER_LGR_MAX];
128 						/* remote addr/key pairs */
129 	unsigned long		rtokens_used_mask[BITS_TO_LONGS(
130 							SMC_RMBS_PER_LGR_MAX)];
131 						/* used rtoken elements */
132 
133 	u8			id[SMC_LGR_ID_SIZE];	/* unique lgr id */
134 	struct delayed_work	free_work;	/* delayed freeing of an lgr */
135 	bool			sync_err;	/* lgr no longer fits to peer */
136 };
137 
138 /* Find the connection associated with the given alert token in the link group.
139  * To use rbtrees we have to implement our own search core.
140  * Requires @conns_lock
141  * @token	alert token to search for
142  * @lgr		 link group to search in
143  * Returns connection associated with token if found, NULL otherwise.
144  */
145 static inline struct smc_connection *smc_lgr_find_conn(
146 	u32 token, struct smc_link_group *lgr)
147 {
148 	struct smc_connection *res = NULL;
149 	struct rb_node *node;
150 
151 	node = lgr->conns_all.rb_node;
152 	while (node) {
153 		struct smc_connection *cur = rb_entry(node,
154 					struct smc_connection, alert_node);
155 
156 		if (cur->alert_token_local > token) {
157 			node = node->rb_left;
158 		} else {
159 			if (cur->alert_token_local < token) {
160 				node = node->rb_right;
161 			} else {
162 				res = cur;
163 				break;
164 			}
165 		}
166 	}
167 
168 	return res;
169 }
170 
171 struct smc_sock;
172 struct smc_clc_msg_accept_confirm;
173 
174 void smc_lgr_free(struct smc_link_group *lgr);
175 void smc_lgr_terminate(struct smc_link_group *lgr);
176 int smc_sndbuf_create(struct smc_sock *smc);
177 int smc_rmb_create(struct smc_sock *smc);
178 int smc_rmb_rtoken_handling(struct smc_connection *conn,
179 			    struct smc_clc_msg_accept_confirm *clc);
180 
181 #endif
182