xref: /linux/net/smc/smc_core.h (revision b04df400c30235fa347313c9e2a0695549bd2c8e)
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 enum smc_link_state {			/* possible states of a link */
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 
43 struct 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 
49 enum 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 
55 struct smc_link {
56 	struct smc_ib_device	*smcibdev;	/* ib-device */
57 	u8			ibport;		/* port - values 1 | 2 */
58 	struct ib_pd		*roce_pd;	/* IB protection domain,
59 						 * unique for every RoCE QP
60 						 */
61 	struct ib_qp		*roce_qp;	/* IB queue pair */
62 	struct ib_qp_attr	qp_attr;	/* IB queue pair attributes */
63 
64 	struct smc_wr_buf	*wr_tx_bufs;	/* WR send payload buffers */
65 	struct ib_send_wr	*wr_tx_ibs;	/* WR send meta data */
66 	struct ib_sge		*wr_tx_sges;	/* WR send gather meta data */
67 	struct smc_wr_tx_pend	*wr_tx_pends;	/* WR send waiting for CQE */
68 	/* above four vectors have wr_tx_cnt elements and use the same index */
69 	dma_addr_t		wr_tx_dma_addr;	/* DMA address of wr_tx_bufs */
70 	atomic_long_t		wr_tx_id;	/* seq # of last sent WR */
71 	unsigned long		*wr_tx_mask;	/* bit mask of used indexes */
72 	u32			wr_tx_cnt;	/* number of WR send buffers */
73 	wait_queue_head_t	wr_tx_wait;	/* wait for free WR send buf */
74 
75 	struct smc_wr_buf	*wr_rx_bufs;	/* WR recv payload buffers */
76 	struct ib_recv_wr	*wr_rx_ibs;	/* WR recv meta data */
77 	struct ib_sge		*wr_rx_sges;	/* WR recv scatter meta data */
78 	/* above three vectors have wr_rx_cnt elements and use the same index */
79 	dma_addr_t		wr_rx_dma_addr;	/* DMA address of wr_rx_bufs */
80 	u64			wr_rx_id;	/* seq # of last recv WR */
81 	u32			wr_rx_cnt;	/* number of WR recv buffers */
82 	unsigned long		wr_rx_tstamp;	/* jiffies when last buf rx */
83 
84 	struct ib_reg_wr	wr_reg;		/* WR register memory region */
85 	wait_queue_head_t	wr_reg_wait;	/* wait for wr_reg result */
86 	enum smc_wr_reg_state	wr_reg_state;	/* state of wr_reg request */
87 
88 	union ib_gid		gid;		/* gid matching used vlan id */
89 	u32			peer_qpn;	/* QP number of peer */
90 	enum ib_mtu		path_mtu;	/* used mtu */
91 	enum ib_mtu		peer_mtu;	/* mtu size of peer */
92 	u32			psn_initial;	/* QP tx initial packet seqno */
93 	u32			peer_psn;	/* QP rx initial packet seqno */
94 	u8			peer_mac[ETH_ALEN];	/* = gid[8:10||13:15] */
95 	u8			peer_gid[sizeof(union ib_gid)];	/* gid of peer*/
96 	u8			link_id;	/* unique # within link group */
97 
98 	enum smc_link_state	state;		/* state of link */
99 	struct workqueue_struct *llc_wq;	/* single thread work queue */
100 	struct completion	llc_confirm;	/* wait for rx of conf link */
101 	struct completion	llc_confirm_resp; /* wait 4 rx of cnf lnk rsp */
102 	int			llc_confirm_rc; /* rc from confirm link msg */
103 	int			llc_confirm_resp_rc; /* rc from conf_resp msg */
104 	struct completion	llc_add;	/* wait for rx of add link */
105 	struct completion	llc_add_resp;	/* wait for rx of add link rsp*/
106 	struct delayed_work	llc_testlink_wrk; /* testlink worker */
107 	struct completion	llc_testlink_resp; /* wait for rx of testlink */
108 	int			llc_testlink_time; /* testlink interval */
109 	struct completion	llc_confirm_rkey; /* wait 4 rx of cnf rkey */
110 	int			llc_confirm_rkey_rc; /* rc from cnf rkey msg */
111 };
112 
113 /* For now we just allow one parallel link per link group. The SMC protocol
114  * allows more (up to 8).
115  */
116 #define SMC_LINKS_PER_LGR_MAX	1
117 #define SMC_SINGLE_LINK		0
118 
119 #define SMC_FIRST_CONTACT	1		/* first contact to a peer */
120 #define SMC_REUSE_CONTACT	0		/* follow-on contact to a peer*/
121 
122 /* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
123 struct smc_buf_desc {
124 	struct list_head	list;
125 	void			*cpu_addr;	/* virtual address of buffer */
126 	struct page		*pages;
127 	struct sg_table		sgt[SMC_LINKS_PER_LGR_MAX];/* virtual buffer */
128 	struct ib_mr		*mr_rx[SMC_LINKS_PER_LGR_MAX];
129 						/* for rmb only: memory region
130 						 * incl. rkey provided to peer
131 						 */
132 	u32			order;		/* allocation order */
133 	u32			used;		/* currently used / unused */
134 	u8			reused	: 1;	/* new created / reused */
135 	u8			regerr	: 1;	/* err during registration */
136 };
137 
138 struct smc_rtoken {				/* address/key of remote RMB */
139 	u64			dma_addr;
140 	u32			rkey;
141 };
142 
143 #define SMC_LGR_ID_SIZE		4
144 
145 struct smc_link_group {
146 	struct list_head	list;
147 	enum smc_lgr_role	role;		/* client or server */
148 	struct smc_link		lnk[SMC_LINKS_PER_LGR_MAX];	/* smc link */
149 	char			peer_systemid[SMC_SYSTEMID_LEN];
150 						/* unique system_id of peer */
151 	struct rb_root		conns_all;	/* connection tree */
152 	rwlock_t		conns_lock;	/* protects conns_all */
153 	unsigned int		conns_num;	/* current # of connections */
154 	unsigned short		vlan_id;	/* vlan id of link group */
155 
156 	struct list_head	sndbufs[SMC_RMBE_SIZES];/* tx buffers */
157 	rwlock_t		sndbufs_lock;	/* protects tx buffers */
158 	struct list_head	rmbs[SMC_RMBE_SIZES];	/* rx buffers */
159 	rwlock_t		rmbs_lock;	/* protects rx buffers */
160 	struct smc_rtoken	rtokens[SMC_RMBS_PER_LGR_MAX]
161 				       [SMC_LINKS_PER_LGR_MAX];
162 						/* remote addr/key pairs */
163 	unsigned long		rtokens_used_mask[BITS_TO_LONGS(
164 							SMC_RMBS_PER_LGR_MAX)];
165 						/* used rtoken elements */
166 
167 	u8			id[SMC_LGR_ID_SIZE];	/* unique lgr id */
168 	struct delayed_work	free_work;	/* delayed freeing of an lgr */
169 	u8			sync_err : 1;	/* lgr no longer fits to peer */
170 	u8			terminating : 1;/* lgr is terminating */
171 };
172 
173 /* Find the connection associated with the given alert token in the link group.
174  * To use rbtrees we have to implement our own search core.
175  * Requires @conns_lock
176  * @token	alert token to search for
177  * @lgr		 link group to search in
178  * Returns connection associated with token if found, NULL otherwise.
179  */
180 static inline struct smc_connection *smc_lgr_find_conn(
181 	u32 token, struct smc_link_group *lgr)
182 {
183 	struct smc_connection *res = NULL;
184 	struct rb_node *node;
185 
186 	node = lgr->conns_all.rb_node;
187 	while (node) {
188 		struct smc_connection *cur = rb_entry(node,
189 					struct smc_connection, alert_node);
190 
191 		if (cur->alert_token_local > token) {
192 			node = node->rb_left;
193 		} else {
194 			if (cur->alert_token_local < token) {
195 				node = node->rb_right;
196 			} else {
197 				res = cur;
198 				break;
199 			}
200 		}
201 	}
202 
203 	return res;
204 }
205 
206 struct smc_sock;
207 struct smc_clc_msg_accept_confirm;
208 
209 void smc_lgr_free(struct smc_link_group *lgr);
210 void smc_lgr_forget(struct smc_link_group *lgr);
211 void smc_lgr_terminate(struct smc_link_group *lgr);
212 int smc_buf_create(struct smc_sock *smc);
213 int smc_rmb_rtoken_handling(struct smc_connection *conn,
214 			    struct smc_clc_msg_accept_confirm *clc);
215 int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey);
216 int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey);
217 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn);
218 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn);
219 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn);
220 void smc_rmb_sync_sg_for_device(struct smc_connection *conn);
221 #endif
222