xref: /openbmc/linux/net/smc/smc_core.h (revision ae213c44)
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_rdma_sge {				/* sges for RDMA writes */
56 	struct ib_sge		wr_tx_rdma_sge[SMC_IB_MAX_SEND_SGE];
57 };
58 
59 #define SMC_MAX_RDMA_WRITES	2		/* max. # of RDMA writes per
60 						 * message send
61 						 */
62 
63 struct smc_rdma_sges {				/* sges per message send */
64 	struct smc_rdma_sge	tx_rdma_sge[SMC_MAX_RDMA_WRITES];
65 };
66 
67 struct smc_rdma_wr {				/* work requests per message
68 						 * send
69 						 */
70 	struct ib_rdma_wr	wr_tx_rdma[SMC_MAX_RDMA_WRITES];
71 };
72 
73 struct smc_link {
74 	struct smc_ib_device	*smcibdev;	/* ib-device */
75 	u8			ibport;		/* port - values 1 | 2 */
76 	struct ib_pd		*roce_pd;	/* IB protection domain,
77 						 * unique for every RoCE QP
78 						 */
79 	struct ib_qp		*roce_qp;	/* IB queue pair */
80 	struct ib_qp_attr	qp_attr;	/* IB queue pair attributes */
81 
82 	struct smc_wr_buf	*wr_tx_bufs;	/* WR send payload buffers */
83 	struct ib_send_wr	*wr_tx_ibs;	/* WR send meta data */
84 	struct ib_sge		*wr_tx_sges;	/* WR send gather meta data */
85 	struct smc_rdma_sges	*wr_tx_rdma_sges;/*RDMA WRITE gather meta data*/
86 	struct smc_rdma_wr	*wr_tx_rdmas;	/* WR RDMA WRITE */
87 	struct smc_wr_tx_pend	*wr_tx_pends;	/* WR send waiting for CQE */
88 	/* above four vectors have wr_tx_cnt elements and use the same index */
89 	dma_addr_t		wr_tx_dma_addr;	/* DMA address of wr_tx_bufs */
90 	atomic_long_t		wr_tx_id;	/* seq # of last sent WR */
91 	unsigned long		*wr_tx_mask;	/* bit mask of used indexes */
92 	u32			wr_tx_cnt;	/* number of WR send buffers */
93 	wait_queue_head_t	wr_tx_wait;	/* wait for free WR send buf */
94 
95 	struct smc_wr_buf	*wr_rx_bufs;	/* WR recv payload buffers */
96 	struct ib_recv_wr	*wr_rx_ibs;	/* WR recv meta data */
97 	struct ib_sge		*wr_rx_sges;	/* WR recv scatter meta data */
98 	/* above three vectors have wr_rx_cnt elements and use the same index */
99 	dma_addr_t		wr_rx_dma_addr;	/* DMA address of wr_rx_bufs */
100 	u64			wr_rx_id;	/* seq # of last recv WR */
101 	u32			wr_rx_cnt;	/* number of WR recv buffers */
102 	unsigned long		wr_rx_tstamp;	/* jiffies when last buf rx */
103 
104 	struct ib_reg_wr	wr_reg;		/* WR register memory region */
105 	wait_queue_head_t	wr_reg_wait;	/* wait for wr_reg result */
106 	enum smc_wr_reg_state	wr_reg_state;	/* state of wr_reg request */
107 
108 	u8			gid[SMC_GID_SIZE];/* gid matching used vlan id*/
109 	u8			sgid_index;	/* gid index for vlan id      */
110 	u32			peer_qpn;	/* QP number of peer */
111 	enum ib_mtu		path_mtu;	/* used mtu */
112 	enum ib_mtu		peer_mtu;	/* mtu size of peer */
113 	u32			psn_initial;	/* QP tx initial packet seqno */
114 	u32			peer_psn;	/* QP rx initial packet seqno */
115 	u8			peer_mac[ETH_ALEN];	/* = gid[8:10||13:15] */
116 	u8			peer_gid[SMC_GID_SIZE];	/* gid of peer*/
117 	u8			link_id;	/* unique # within link group */
118 
119 	enum smc_link_state	state;		/* state of link */
120 	struct workqueue_struct *llc_wq;	/* single thread work queue */
121 	struct completion	llc_confirm;	/* wait for rx of conf link */
122 	struct completion	llc_confirm_resp; /* wait 4 rx of cnf lnk rsp */
123 	int			llc_confirm_rc; /* rc from confirm link msg */
124 	int			llc_confirm_resp_rc; /* rc from conf_resp msg */
125 	struct completion	llc_add;	/* wait for rx of add link */
126 	struct completion	llc_add_resp;	/* wait for rx of add link rsp*/
127 	struct delayed_work	llc_testlink_wrk; /* testlink worker */
128 	struct completion	llc_testlink_resp; /* wait for rx of testlink */
129 	int			llc_testlink_time; /* testlink interval */
130 	struct completion	llc_confirm_rkey; /* wait 4 rx of cnf rkey */
131 	int			llc_confirm_rkey_rc; /* rc from cnf rkey msg */
132 	struct completion	llc_delete_rkey; /* wait 4 rx of del rkey */
133 	int			llc_delete_rkey_rc; /* rc from del rkey msg */
134 	struct mutex		llc_delete_rkey_mutex; /* serialize usage */
135 };
136 
137 /* For now we just allow one parallel link per link group. The SMC protocol
138  * allows more (up to 8).
139  */
140 #define SMC_LINKS_PER_LGR_MAX	1
141 #define SMC_SINGLE_LINK		0
142 
143 #define SMC_FIRST_CONTACT	1		/* first contact to a peer */
144 #define SMC_REUSE_CONTACT	0		/* follow-on contact to a peer*/
145 
146 /* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
147 struct smc_buf_desc {
148 	struct list_head	list;
149 	void			*cpu_addr;	/* virtual address of buffer */
150 	struct page		*pages;
151 	int			len;		/* length of buffer */
152 	u32			used;		/* currently used / unused */
153 	u8			wr_reg	: 1;	/* mem region registered */
154 	u8			regerr	: 1;	/* err during registration */
155 	union {
156 		struct { /* SMC-R */
157 			struct sg_table		sgt[SMC_LINKS_PER_LGR_MAX];
158 						/* virtual buffer */
159 			struct ib_mr		*mr_rx[SMC_LINKS_PER_LGR_MAX];
160 						/* for rmb only: memory region
161 						 * incl. rkey provided to peer
162 						 */
163 			u32			order;	/* allocation order */
164 		};
165 		struct { /* SMC-D */
166 			unsigned short		sba_idx;
167 						/* SBA index number */
168 			u64			token;
169 						/* DMB token number */
170 			dma_addr_t		dma_addr;
171 						/* DMA address */
172 		};
173 	};
174 };
175 
176 struct smc_rtoken {				/* address/key of remote RMB */
177 	u64			dma_addr;
178 	u32			rkey;
179 };
180 
181 #define SMC_LGR_ID_SIZE		4
182 #define SMC_BUF_MIN_SIZE	16384	/* minimum size of an RMB */
183 #define SMC_RMBE_SIZES		16	/* number of distinct RMBE sizes */
184 /* theoretically, the RFC states that largest size would be 512K,
185  * i.e. compressed 5 and thus 6 sizes (0..5), despite
186  * struct smc_clc_msg_accept_confirm.rmbe_size being a 4 bit value (0..15)
187  */
188 
189 struct smcd_dev;
190 
191 struct smc_link_group {
192 	struct list_head	list;
193 	struct rb_root		conns_all;	/* connection tree */
194 	rwlock_t		conns_lock;	/* protects conns_all */
195 	unsigned int		conns_num;	/* current # of connections */
196 	unsigned short		vlan_id;	/* vlan id of link group */
197 
198 	struct list_head	sndbufs[SMC_RMBE_SIZES];/* tx buffers */
199 	rwlock_t		sndbufs_lock;	/* protects tx buffers */
200 	struct list_head	rmbs[SMC_RMBE_SIZES];	/* rx buffers */
201 	rwlock_t		rmbs_lock;	/* protects rx buffers */
202 
203 	u8			id[SMC_LGR_ID_SIZE];	/* unique lgr id */
204 	struct delayed_work	free_work;	/* delayed freeing of an lgr */
205 	u8			sync_err : 1;	/* lgr no longer fits to peer */
206 	u8			terminating : 1;/* lgr is terminating */
207 
208 	bool			is_smcd;	/* SMC-R or SMC-D */
209 	union {
210 		struct { /* SMC-R */
211 			enum smc_lgr_role	role;
212 						/* client or server */
213 			struct smc_link		lnk[SMC_LINKS_PER_LGR_MAX];
214 						/* smc link */
215 			char			peer_systemid[SMC_SYSTEMID_LEN];
216 						/* unique system_id of peer */
217 			struct smc_rtoken	rtokens[SMC_RMBS_PER_LGR_MAX]
218 						[SMC_LINKS_PER_LGR_MAX];
219 						/* remote addr/key pairs */
220 			DECLARE_BITMAP(rtokens_used_mask, SMC_RMBS_PER_LGR_MAX);
221 						/* used rtoken elements */
222 		};
223 		struct { /* SMC-D */
224 			u64			peer_gid;
225 						/* Peer GID (remote) */
226 			struct smcd_dev		*smcd;
227 						/* ISM device for VLAN reg. */
228 		};
229 	};
230 };
231 
232 struct smc_clc_msg_local;
233 
234 struct smc_init_info {
235 	u8			is_smcd;
236 	unsigned short		vlan_id;
237 	int			srv_first_contact;
238 	int			cln_first_contact;
239 	/* SMC-R */
240 	struct smc_clc_msg_local *ib_lcl;
241 	struct smc_ib_device	*ib_dev;
242 	u8			ib_gid[SMC_GID_SIZE];
243 	u8			ib_port;
244 	u32			ib_clcqpn;
245 	/* SMC-D */
246 	u64			ism_gid;
247 	struct smcd_dev		*ism_dev;
248 };
249 
250 /* Find the connection associated with the given alert token in the link group.
251  * To use rbtrees we have to implement our own search core.
252  * Requires @conns_lock
253  * @token	alert token to search for
254  * @lgr		 link group to search in
255  * Returns connection associated with token if found, NULL otherwise.
256  */
257 static inline struct smc_connection *smc_lgr_find_conn(
258 	u32 token, struct smc_link_group *lgr)
259 {
260 	struct smc_connection *res = NULL;
261 	struct rb_node *node;
262 
263 	node = lgr->conns_all.rb_node;
264 	while (node) {
265 		struct smc_connection *cur = rb_entry(node,
266 					struct smc_connection, alert_node);
267 
268 		if (cur->alert_token_local > token) {
269 			node = node->rb_left;
270 		} else {
271 			if (cur->alert_token_local < token) {
272 				node = node->rb_right;
273 			} else {
274 				res = cur;
275 				break;
276 			}
277 		}
278 	}
279 
280 	return res;
281 }
282 
283 struct smc_sock;
284 struct smc_clc_msg_accept_confirm;
285 struct smc_clc_msg_local;
286 
287 void smc_lgr_forget(struct smc_link_group *lgr);
288 void smc_lgr_terminate(struct smc_link_group *lgr);
289 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport);
290 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid,
291 			unsigned short vlan);
292 int smc_buf_create(struct smc_sock *smc, bool is_smcd);
293 int smc_uncompress_bufsize(u8 compressed);
294 int smc_rmb_rtoken_handling(struct smc_connection *conn,
295 			    struct smc_clc_msg_accept_confirm *clc);
296 int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey);
297 int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey);
298 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn);
299 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn);
300 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn);
301 void smc_rmb_sync_sg_for_device(struct smc_connection *conn);
302 int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini);
303 
304 void smc_conn_free(struct smc_connection *conn);
305 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini);
306 void smcd_conn_free(struct smc_connection *conn);
307 void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr);
308 void smc_core_exit(void);
309 
310 static inline struct smc_link_group *smc_get_lgr(struct smc_link *link)
311 {
312 	return container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);
313 }
314 #endif
315