xref: /openbmc/linux/net/smc/smc_core.h (revision 5d331b7f)
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 };
113 
114 /* For now we just allow one parallel link per link group. The SMC protocol
115  * allows more (up to 8).
116  */
117 #define SMC_LINKS_PER_LGR_MAX	1
118 #define SMC_SINGLE_LINK		0
119 
120 #define SMC_FIRST_CONTACT	1		/* first contact to a peer */
121 #define SMC_REUSE_CONTACT	0		/* follow-on contact to a peer*/
122 
123 /* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
124 struct smc_buf_desc {
125 	struct list_head	list;
126 	void			*cpu_addr;	/* virtual address of buffer */
127 	struct page		*pages;
128 	int			len;		/* length of buffer */
129 	u32			used;		/* currently used / unused */
130 	u8			reused	: 1;	/* new created / reused */
131 	u8			regerr	: 1;	/* err during registration */
132 	union {
133 		struct { /* SMC-R */
134 			struct sg_table		sgt[SMC_LINKS_PER_LGR_MAX];
135 						/* virtual buffer */
136 			struct ib_mr		*mr_rx[SMC_LINKS_PER_LGR_MAX];
137 						/* for rmb only: memory region
138 						 * incl. rkey provided to peer
139 						 */
140 			u32			order;	/* allocation order */
141 		};
142 		struct { /* SMC-D */
143 			unsigned short		sba_idx;
144 						/* SBA index number */
145 			u64			token;
146 						/* DMB token number */
147 			dma_addr_t		dma_addr;
148 						/* DMA address */
149 		};
150 	};
151 };
152 
153 struct smc_rtoken {				/* address/key of remote RMB */
154 	u64			dma_addr;
155 	u32			rkey;
156 };
157 
158 #define SMC_LGR_ID_SIZE		4
159 #define SMC_BUF_MIN_SIZE	16384	/* minimum size of an RMB */
160 #define SMC_RMBE_SIZES		16	/* number of distinct RMBE sizes */
161 /* theoretically, the RFC states that largest size would be 512K,
162  * i.e. compressed 5 and thus 6 sizes (0..5), despite
163  * struct smc_clc_msg_accept_confirm.rmbe_size being a 4 bit value (0..15)
164  */
165 
166 struct smcd_dev;
167 
168 struct smc_link_group {
169 	struct list_head	list;
170 	struct rb_root		conns_all;	/* connection tree */
171 	rwlock_t		conns_lock;	/* protects conns_all */
172 	unsigned int		conns_num;	/* current # of connections */
173 	unsigned short		vlan_id;	/* vlan id of link group */
174 
175 	struct list_head	sndbufs[SMC_RMBE_SIZES];/* tx buffers */
176 	rwlock_t		sndbufs_lock;	/* protects tx buffers */
177 	struct list_head	rmbs[SMC_RMBE_SIZES];	/* rx buffers */
178 	rwlock_t		rmbs_lock;	/* protects rx buffers */
179 
180 	u8			id[SMC_LGR_ID_SIZE];	/* unique lgr id */
181 	struct delayed_work	free_work;	/* delayed freeing of an lgr */
182 	u8			sync_err : 1;	/* lgr no longer fits to peer */
183 	u8			terminating : 1;/* lgr is terminating */
184 
185 	bool			is_smcd;	/* SMC-R or SMC-D */
186 	union {
187 		struct { /* SMC-R */
188 			enum smc_lgr_role	role;
189 						/* client or server */
190 			struct smc_link		lnk[SMC_LINKS_PER_LGR_MAX];
191 						/* smc link */
192 			char			peer_systemid[SMC_SYSTEMID_LEN];
193 						/* unique system_id of peer */
194 			struct smc_rtoken	rtokens[SMC_RMBS_PER_LGR_MAX]
195 						[SMC_LINKS_PER_LGR_MAX];
196 						/* remote addr/key pairs */
197 			DECLARE_BITMAP(rtokens_used_mask, SMC_RMBS_PER_LGR_MAX);
198 						/* used rtoken elements */
199 		};
200 		struct { /* SMC-D */
201 			u64			peer_gid;
202 						/* Peer GID (remote) */
203 			struct smcd_dev		*smcd;
204 						/* ISM device for VLAN reg. */
205 		};
206 	};
207 };
208 
209 /* Find the connection associated with the given alert token in the link group.
210  * To use rbtrees we have to implement our own search core.
211  * Requires @conns_lock
212  * @token	alert token to search for
213  * @lgr		 link group to search in
214  * Returns connection associated with token if found, NULL otherwise.
215  */
216 static inline struct smc_connection *smc_lgr_find_conn(
217 	u32 token, struct smc_link_group *lgr)
218 {
219 	struct smc_connection *res = NULL;
220 	struct rb_node *node;
221 
222 	node = lgr->conns_all.rb_node;
223 	while (node) {
224 		struct smc_connection *cur = rb_entry(node,
225 					struct smc_connection, alert_node);
226 
227 		if (cur->alert_token_local > token) {
228 			node = node->rb_left;
229 		} else {
230 			if (cur->alert_token_local < token) {
231 				node = node->rb_right;
232 			} else {
233 				res = cur;
234 				break;
235 			}
236 		}
237 	}
238 
239 	return res;
240 }
241 
242 struct smc_sock;
243 struct smc_clc_msg_accept_confirm;
244 struct smc_clc_msg_local;
245 
246 void smc_lgr_free(struct smc_link_group *lgr);
247 void smc_lgr_forget(struct smc_link_group *lgr);
248 void smc_lgr_terminate(struct smc_link_group *lgr);
249 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport);
250 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid);
251 int smc_buf_create(struct smc_sock *smc, bool is_smcd);
252 int smc_uncompress_bufsize(u8 compressed);
253 int smc_rmb_rtoken_handling(struct smc_connection *conn,
254 			    struct smc_clc_msg_accept_confirm *clc);
255 int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey);
256 int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey);
257 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn);
258 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn);
259 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn);
260 void smc_rmb_sync_sg_for_device(struct smc_connection *conn);
261 int smc_vlan_by_tcpsk(struct socket *clcsock, unsigned short *vlan_id);
262 
263 void smc_conn_free(struct smc_connection *conn);
264 int smc_conn_create(struct smc_sock *smc, bool is_smcd, int srv_first_contact,
265 		    struct smc_ib_device *smcibdev, u8 ibport,
266 		    struct smc_clc_msg_local *lcl, struct smcd_dev *smcd,
267 		    u64 peer_gid);
268 void smcd_conn_free(struct smc_connection *conn);
269 void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr);
270 void smc_core_exit(void);
271 
272 static inline struct smc_link_group *smc_get_lgr(struct smc_link *link)
273 {
274 	return container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);
275 }
276 #endif
277