xref: /linux/net/smc/smc_core.h (revision 5bdd5fbb35ab0fe21bf2263106f51c5bee466a07)
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 	u32			num;	/* unique link group number */
27 };
28 
29 enum smc_lgr_role {		/* possible roles of a link group */
30 	SMC_CLNT,	/* client */
31 	SMC_SERV	/* server */
32 };
33 
34 enum smc_link_state {			/* possible states of a link */
35 	SMC_LNK_INACTIVE,	/* link is inactive */
36 	SMC_LNK_ACTIVATING,	/* link is being activated */
37 	SMC_LNK_ACTIVE		/* link is active */
38 };
39 
40 #define SMC_WR_BUF_SIZE		48	/* size of work request buffer */
41 
42 struct smc_wr_buf {
43 	u8	raw[SMC_WR_BUF_SIZE];
44 };
45 
46 #define SMC_WR_REG_MR_WAIT_TIME	(5 * HZ)/* wait time for ib_wr_reg_mr result */
47 
48 enum smc_wr_reg_state {
49 	POSTED,		/* ib_wr_reg_mr request posted */
50 	CONFIRMED,	/* ib_wr_reg_mr response: successful */
51 	FAILED		/* ib_wr_reg_mr response: failure */
52 };
53 
54 struct smc_link {
55 	struct smc_ib_device	*smcibdev;	/* ib-device */
56 	u8			ibport;		/* port - values 1 | 2 */
57 	struct ib_pd		*roce_pd;	/* IB protection domain,
58 						 * unique for every RoCE QP
59 						 */
60 	struct ib_qp		*roce_qp;	/* IB queue pair */
61 	struct ib_qp_attr	qp_attr;	/* IB queue pair attributes */
62 
63 	struct smc_wr_buf	*wr_tx_bufs;	/* WR send payload buffers */
64 	struct ib_send_wr	*wr_tx_ibs;	/* WR send meta data */
65 	struct ib_sge		*wr_tx_sges;	/* WR send gather meta data */
66 	struct smc_wr_tx_pend	*wr_tx_pends;	/* WR send waiting for CQE */
67 	/* above four vectors have wr_tx_cnt elements and use the same index */
68 	dma_addr_t		wr_tx_dma_addr;	/* DMA address of wr_tx_bufs */
69 	atomic_long_t		wr_tx_id;	/* seq # of last sent WR */
70 	unsigned long		*wr_tx_mask;	/* bit mask of used indexes */
71 	u32			wr_tx_cnt;	/* number of WR send buffers */
72 	wait_queue_head_t	wr_tx_wait;	/* wait for free WR send buf */
73 
74 	struct smc_wr_buf	*wr_rx_bufs;	/* WR recv payload buffers */
75 	struct ib_recv_wr	*wr_rx_ibs;	/* WR recv meta data */
76 	struct ib_sge		*wr_rx_sges;	/* WR recv scatter meta data */
77 	/* above three vectors have wr_rx_cnt elements and use the same index */
78 	dma_addr_t		wr_rx_dma_addr;	/* DMA address of wr_rx_bufs */
79 	u64			wr_rx_id;	/* seq # of last recv WR */
80 	u32			wr_rx_cnt;	/* number of WR recv buffers */
81 	unsigned long		wr_rx_tstamp;	/* jiffies when last buf rx */
82 
83 	struct ib_reg_wr	wr_reg;		/* WR register memory region */
84 	wait_queue_head_t	wr_reg_wait;	/* wait for wr_reg result */
85 	enum smc_wr_reg_state	wr_reg_state;	/* state of wr_reg request */
86 
87 	union ib_gid		gid;		/* gid matching used vlan id */
88 	u32			peer_qpn;	/* QP number of peer */
89 	enum ib_mtu		path_mtu;	/* used mtu */
90 	enum ib_mtu		peer_mtu;	/* mtu size of peer */
91 	u32			psn_initial;	/* QP tx initial packet seqno */
92 	u32			peer_psn;	/* QP rx initial packet seqno */
93 	u8			peer_mac[ETH_ALEN];	/* = gid[8:10||13:15] */
94 	u8			peer_gid[sizeof(union ib_gid)];	/* gid of peer*/
95 	u8			link_id;	/* unique # within link group */
96 
97 	enum smc_link_state	state;		/* state of link */
98 	struct workqueue_struct *llc_wq;	/* single thread work queue */
99 	struct completion	llc_confirm;	/* wait for rx of conf link */
100 	struct completion	llc_confirm_resp; /* wait 4 rx of cnf lnk rsp */
101 	int			llc_confirm_rc; /* rc from confirm link msg */
102 	int			llc_confirm_resp_rc; /* rc from conf_resp msg */
103 	struct completion	llc_add;	/* wait for rx of add link */
104 	struct completion	llc_add_resp;	/* wait for rx of add link rsp*/
105 	struct delayed_work	llc_testlink_wrk; /* testlink worker */
106 	struct completion	llc_testlink_resp; /* wait for rx of testlink */
107 	int			llc_testlink_time; /* testlink interval */
108 	struct completion	llc_confirm_rkey; /* wait 4 rx of cnf rkey */
109 	int			llc_confirm_rkey_rc; /* rc from cnf rkey msg */
110 };
111 
112 /* For now we just allow one parallel link per link group. The SMC protocol
113  * allows more (up to 8).
114  */
115 #define SMC_LINKS_PER_LGR_MAX	1
116 #define SMC_SINGLE_LINK		0
117 
118 #define SMC_FIRST_CONTACT	1		/* first contact to a peer */
119 #define SMC_REUSE_CONTACT	0		/* follow-on contact to a peer*/
120 
121 /* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
122 struct smc_buf_desc {
123 	struct list_head	list;
124 	void			*cpu_addr;	/* virtual address of buffer */
125 	struct page		*pages;
126 	int			len;		/* length of buffer */
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 #define SMC_BUF_MIN_SIZE	16384	/* minimum size of an RMB */
145 #define SMC_RMBE_SIZES		16	/* number of distinct RMBE sizes */
146 /* theoretically, the RFC states that largest size would be 512K,
147  * i.e. compressed 5 and thus 6 sizes (0..5), despite
148  * struct smc_clc_msg_accept_confirm.rmbe_size being a 4 bit value (0..15)
149  */
150 
151 struct smc_link_group {
152 	struct list_head	list;
153 	enum smc_lgr_role	role;		/* client or server */
154 	struct smc_link		lnk[SMC_LINKS_PER_LGR_MAX];	/* smc link */
155 	char			peer_systemid[SMC_SYSTEMID_LEN];
156 						/* unique system_id of peer */
157 	struct rb_root		conns_all;	/* connection tree */
158 	rwlock_t		conns_lock;	/* protects conns_all */
159 	unsigned int		conns_num;	/* current # of connections */
160 	unsigned short		vlan_id;	/* vlan id of link group */
161 
162 	struct list_head	sndbufs[SMC_RMBE_SIZES];/* tx buffers */
163 	rwlock_t		sndbufs_lock;	/* protects tx buffers */
164 	struct list_head	rmbs[SMC_RMBE_SIZES];	/* rx buffers */
165 	rwlock_t		rmbs_lock;	/* protects rx buffers */
166 	struct smc_rtoken	rtokens[SMC_RMBS_PER_LGR_MAX]
167 				       [SMC_LINKS_PER_LGR_MAX];
168 						/* remote addr/key pairs */
169 	unsigned long		rtokens_used_mask[BITS_TO_LONGS(
170 							SMC_RMBS_PER_LGR_MAX)];
171 						/* used rtoken elements */
172 
173 	u8			id[SMC_LGR_ID_SIZE];	/* unique lgr id */
174 	struct delayed_work	free_work;	/* delayed freeing of an lgr */
175 	u8			sync_err : 1;	/* lgr no longer fits to peer */
176 	u8			terminating : 1;/* lgr is terminating */
177 };
178 
179 /* Find the connection associated with the given alert token in the link group.
180  * To use rbtrees we have to implement our own search core.
181  * Requires @conns_lock
182  * @token	alert token to search for
183  * @lgr		 link group to search in
184  * Returns connection associated with token if found, NULL otherwise.
185  */
186 static inline struct smc_connection *smc_lgr_find_conn(
187 	u32 token, struct smc_link_group *lgr)
188 {
189 	struct smc_connection *res = NULL;
190 	struct rb_node *node;
191 
192 	node = lgr->conns_all.rb_node;
193 	while (node) {
194 		struct smc_connection *cur = rb_entry(node,
195 					struct smc_connection, alert_node);
196 
197 		if (cur->alert_token_local > token) {
198 			node = node->rb_left;
199 		} else {
200 			if (cur->alert_token_local < token) {
201 				node = node->rb_right;
202 			} else {
203 				res = cur;
204 				break;
205 			}
206 		}
207 	}
208 
209 	return res;
210 }
211 
212 struct smc_sock;
213 struct smc_clc_msg_accept_confirm;
214 struct smc_clc_msg_local;
215 
216 void smc_lgr_free(struct smc_link_group *lgr);
217 void smc_lgr_forget(struct smc_link_group *lgr);
218 void smc_lgr_terminate(struct smc_link_group *lgr);
219 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport);
220 int smc_buf_create(struct smc_sock *smc);
221 int smc_uncompress_bufsize(u8 compressed);
222 int smc_rmb_rtoken_handling(struct smc_connection *conn,
223 			    struct smc_clc_msg_accept_confirm *clc);
224 int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey);
225 int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey);
226 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn);
227 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn);
228 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn);
229 void smc_rmb_sync_sg_for_device(struct smc_connection *conn);
230 void smc_conn_free(struct smc_connection *conn);
231 int smc_conn_create(struct smc_sock *smc,
232 		    struct smc_ib_device *smcibdev, u8 ibport,
233 		    struct smc_clc_msg_local *lcl, int srv_first_contact);
234 void smc_core_exit(void);
235 #endif
236