xref: /openbmc/linux/net/smc/smc_core.h (revision 2c6467d2)
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 	SMC_LNK_DELETING,	/* link is being deleted */
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 	u8			gid[SMC_GID_SIZE];/* gid matching used vlan id*/
89 	u8			sgid_index;	/* gid index for vlan id      */
90 	u32			peer_qpn;	/* QP number of peer */
91 	enum ib_mtu		path_mtu;	/* used mtu */
92 	enum ib_mtu		peer_mtu;	/* mtu size of peer */
93 	u32			psn_initial;	/* QP tx initial packet seqno */
94 	u32			peer_psn;	/* QP rx initial packet seqno */
95 	u8			peer_mac[ETH_ALEN];	/* = gid[8:10||13:15] */
96 	u8			peer_gid[SMC_GID_SIZE];	/* gid of peer*/
97 	u8			link_id;	/* unique # within link group */
98 
99 	enum smc_link_state	state;		/* state of link */
100 	struct workqueue_struct *llc_wq;	/* single thread work queue */
101 	struct completion	llc_confirm;	/* wait for rx of conf link */
102 	struct completion	llc_confirm_resp; /* wait 4 rx of cnf lnk rsp */
103 	int			llc_confirm_rc; /* rc from confirm link msg */
104 	int			llc_confirm_resp_rc; /* rc from conf_resp msg */
105 	struct completion	llc_add;	/* wait for rx of add link */
106 	struct completion	llc_add_resp;	/* wait for rx of add link rsp*/
107 	struct delayed_work	llc_testlink_wrk; /* testlink worker */
108 	struct completion	llc_testlink_resp; /* wait for rx of testlink */
109 	int			llc_testlink_time; /* testlink interval */
110 	struct completion	llc_confirm_rkey; /* wait 4 rx of cnf rkey */
111 	int			llc_confirm_rkey_rc; /* rc from cnf rkey msg */
112 	struct completion	llc_delete_rkey; /* wait 4 rx of del rkey */
113 	int			llc_delete_rkey_rc; /* rc from del rkey msg */
114 	struct mutex		llc_delete_rkey_mutex; /* serialize usage */
115 };
116 
117 /* For now we just allow one parallel link per link group. The SMC protocol
118  * allows more (up to 8).
119  */
120 #define SMC_LINKS_PER_LGR_MAX	1
121 #define SMC_SINGLE_LINK		0
122 
123 #define SMC_FIRST_CONTACT	1		/* first contact to a peer */
124 #define SMC_REUSE_CONTACT	0		/* follow-on contact to a peer*/
125 
126 /* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
127 struct smc_buf_desc {
128 	struct list_head	list;
129 	void			*cpu_addr;	/* virtual address of buffer */
130 	struct page		*pages;
131 	int			len;		/* length of buffer */
132 	u32			used;		/* currently used / unused */
133 	u8			wr_reg	: 1;	/* mem region registered */
134 	u8			regerr	: 1;	/* err during registration */
135 	union {
136 		struct { /* SMC-R */
137 			struct sg_table		sgt[SMC_LINKS_PER_LGR_MAX];
138 						/* virtual buffer */
139 			struct ib_mr		*mr_rx[SMC_LINKS_PER_LGR_MAX];
140 						/* for rmb only: memory region
141 						 * incl. rkey provided to peer
142 						 */
143 			u32			order;	/* allocation order */
144 		};
145 		struct { /* SMC-D */
146 			unsigned short		sba_idx;
147 						/* SBA index number */
148 			u64			token;
149 						/* DMB token number */
150 			dma_addr_t		dma_addr;
151 						/* DMA address */
152 		};
153 	};
154 };
155 
156 struct smc_rtoken {				/* address/key of remote RMB */
157 	u64			dma_addr;
158 	u32			rkey;
159 };
160 
161 #define SMC_LGR_ID_SIZE		4
162 #define SMC_BUF_MIN_SIZE	16384	/* minimum size of an RMB */
163 #define SMC_RMBE_SIZES		16	/* number of distinct RMBE sizes */
164 /* theoretically, the RFC states that largest size would be 512K,
165  * i.e. compressed 5 and thus 6 sizes (0..5), despite
166  * struct smc_clc_msg_accept_confirm.rmbe_size being a 4 bit value (0..15)
167  */
168 
169 struct smcd_dev;
170 
171 struct smc_link_group {
172 	struct list_head	list;
173 	struct rb_root		conns_all;	/* connection tree */
174 	rwlock_t		conns_lock;	/* protects conns_all */
175 	unsigned int		conns_num;	/* current # of connections */
176 	unsigned short		vlan_id;	/* vlan id of link group */
177 
178 	struct list_head	sndbufs[SMC_RMBE_SIZES];/* tx buffers */
179 	rwlock_t		sndbufs_lock;	/* protects tx buffers */
180 	struct list_head	rmbs[SMC_RMBE_SIZES];	/* rx buffers */
181 	rwlock_t		rmbs_lock;	/* protects rx buffers */
182 
183 	u8			id[SMC_LGR_ID_SIZE];	/* unique lgr id */
184 	struct delayed_work	free_work;	/* delayed freeing of an lgr */
185 	u8			sync_err : 1;	/* lgr no longer fits to peer */
186 	u8			terminating : 1;/* lgr is terminating */
187 
188 	bool			is_smcd;	/* SMC-R or SMC-D */
189 	union {
190 		struct { /* SMC-R */
191 			enum smc_lgr_role	role;
192 						/* client or server */
193 			struct smc_link		lnk[SMC_LINKS_PER_LGR_MAX];
194 						/* smc link */
195 			char			peer_systemid[SMC_SYSTEMID_LEN];
196 						/* unique system_id of peer */
197 			struct smc_rtoken	rtokens[SMC_RMBS_PER_LGR_MAX]
198 						[SMC_LINKS_PER_LGR_MAX];
199 						/* remote addr/key pairs */
200 			DECLARE_BITMAP(rtokens_used_mask, SMC_RMBS_PER_LGR_MAX);
201 						/* used rtoken elements */
202 		};
203 		struct { /* SMC-D */
204 			u64			peer_gid;
205 						/* Peer GID (remote) */
206 			struct smcd_dev		*smcd;
207 						/* ISM device for VLAN reg. */
208 		};
209 	};
210 };
211 
212 /* Find the connection associated with the given alert token in the link group.
213  * To use rbtrees we have to implement our own search core.
214  * Requires @conns_lock
215  * @token	alert token to search for
216  * @lgr		 link group to search in
217  * Returns connection associated with token if found, NULL otherwise.
218  */
219 static inline struct smc_connection *smc_lgr_find_conn(
220 	u32 token, struct smc_link_group *lgr)
221 {
222 	struct smc_connection *res = NULL;
223 	struct rb_node *node;
224 
225 	node = lgr->conns_all.rb_node;
226 	while (node) {
227 		struct smc_connection *cur = rb_entry(node,
228 					struct smc_connection, alert_node);
229 
230 		if (cur->alert_token_local > token) {
231 			node = node->rb_left;
232 		} else {
233 			if (cur->alert_token_local < token) {
234 				node = node->rb_right;
235 			} else {
236 				res = cur;
237 				break;
238 			}
239 		}
240 	}
241 
242 	return res;
243 }
244 
245 struct smc_sock;
246 struct smc_clc_msg_accept_confirm;
247 struct smc_clc_msg_local;
248 
249 void smc_lgr_forget(struct smc_link_group *lgr);
250 void smc_lgr_terminate(struct smc_link_group *lgr);
251 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport);
252 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid,
253 			unsigned short vlan);
254 int smc_buf_create(struct smc_sock *smc, bool is_smcd);
255 int smc_uncompress_bufsize(u8 compressed);
256 int smc_rmb_rtoken_handling(struct smc_connection *conn,
257 			    struct smc_clc_msg_accept_confirm *clc);
258 int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey);
259 int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey);
260 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn);
261 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn);
262 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn);
263 void smc_rmb_sync_sg_for_device(struct smc_connection *conn);
264 int smc_vlan_by_tcpsk(struct socket *clcsock, unsigned short *vlan_id);
265 
266 void smc_conn_free(struct smc_connection *conn);
267 int smc_conn_create(struct smc_sock *smc, bool is_smcd, int srv_first_contact,
268 		    struct smc_ib_device *smcibdev, u8 ibport, u32 clcqpn,
269 		    struct smc_clc_msg_local *lcl, struct smcd_dev *smcd,
270 		    u64 peer_gid);
271 void smcd_conn_free(struct smc_connection *conn);
272 void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr);
273 void smc_core_exit(void);
274 
275 static inline struct smc_link_group *smc_get_lgr(struct smc_link *link)
276 {
277 	return container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);
278 }
279 #endif
280