xref: /linux/drivers/infiniband/ulp/rtrs/rtrs.h (revision 6ce4d44fb0ca00644756c7e857166d12ffb4b833)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * RDMA Transport Layer
4  *
5  * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
6  * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
7  * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
8  */
9 #ifndef RTRS_H
10 #define RTRS_H
11 
12 #include <linux/socket.h>
13 #include <linux/scatterlist.h>
14 
15 struct rtrs_permit;
16 struct rtrs_clt_sess;
17 struct rtrs_srv_ctx;
18 struct rtrs_srv_sess;
19 struct rtrs_srv_op;
20 
21 /*
22  * RDMA transport (RTRS) client API
23  */
24 
25 /**
26  * enum rtrs_clt_link_ev - Events about connectivity state of a client
27  * @RTRS_CLT_LINK_EV_RECONNECTED:	Client was reconnected.
28  * @RTRS_CLT_LINK_EV_DISCONNECTED:	Client was disconnected.
29  */
30 enum rtrs_clt_link_ev {
31 	RTRS_CLT_LINK_EV_RECONNECTED,
32 	RTRS_CLT_LINK_EV_DISCONNECTED,
33 };
34 
35 /**
36  * struct rtrs_addr - Source and destination address of a path to be established
37  * @src:	source address
38  * @dst:	destination address
39  */
40 struct rtrs_addr {
41 	struct sockaddr_storage *src;
42 	struct sockaddr_storage *dst;
43 };
44 
45 /**
46  * struct rtrs_clt_ops - it holds the link event callback and private pointer.
47  * @priv: User supplied private data.
48  * @link_ev: Event notification callback function for connection state changes
49  *	@priv: User supplied data that was passed to rtrs_clt_open()
50  *	@ev: Occurred event
51  */
52 struct rtrs_clt_ops {
53 	void	*priv;
54 	void	(*link_ev)(void *priv, enum rtrs_clt_link_ev ev);
55 };
56 
57 struct rtrs_clt_sess *rtrs_clt_open(struct rtrs_clt_ops *ops,
58 				 const char *pathname,
59 				 const struct rtrs_addr *paths,
60 				 size_t path_cnt, u16 port,
61 				 size_t pdu_sz, u8 reconnect_delay_sec,
62 				 s16 max_reconnect_attempts, u32 nr_poll_queues);
63 
64 void rtrs_clt_close(struct rtrs_clt_sess *clt);
65 
66 enum wait_type {
67 	RTRS_PERMIT_NOWAIT = 0,
68 	RTRS_PERMIT_WAIT   = 1
69 };
70 
71 /**
72  * enum rtrs_clt_con_type - type of ib connection to use with a given
73  * rtrs_permit
74  * @RTRS_ADMIN_CON: use connection reserved for "service" messages
75  * @RTRS_IO_CON: use a connection reserved for IO
76  */
77 enum rtrs_clt_con_type {
78 	RTRS_ADMIN_CON,
79 	RTRS_IO_CON
80 };
81 
82 struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt_sess *sess,
83 					enum rtrs_clt_con_type con_type,
84 					enum wait_type wait);
85 
86 void rtrs_clt_put_permit(struct rtrs_clt_sess *sess,
87 			 struct rtrs_permit *permit);
88 
89 /**
90  * struct rtrs_clt_req_ops - it holds the request confirmation callback
91  * and a private pointer.
92  * @priv: User supplied private data.
93  * @conf_fn:	callback function to be called as confirmation
94  *	@priv:	User provided data, passed back with corresponding
95  *		@(conf) confirmation.
96  *	@errno: error number.
97  */
98 struct rtrs_clt_req_ops {
99 	void	*priv;
100 	void	(*conf_fn)(void *priv, int errno);
101 };
102 
103 int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
104 		     struct rtrs_clt_sess *sess, struct rtrs_permit *permit,
105 		     const struct kvec *vec, size_t nr, size_t len,
106 		     struct scatterlist *sg, unsigned int sg_cnt);
107 int rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess *clt, unsigned int index);
108 
109 /**
110  * struct rtrs_attrs - RTRS session attributes
111  * @queue_depth:	queue_depth saved from rtrs_clt_sess message
112  * @max_io_size:	max_io_size from rtrs_clt_sess message, capped to
113  *			  @max_segments * %SZ_4K
114  * @max_segments:	max_segments saved from rtrs_clt_sess message
115  */
116 struct rtrs_attrs {
117 	u32		queue_depth;
118 	u32		max_io_size;
119 	u32		max_segments;
120 };
121 
122 int rtrs_clt_query(struct rtrs_clt_sess *sess, struct rtrs_attrs *attr);
123 
124 /*
125  * Here goes RTRS server API
126  */
127 
128 /**
129  * enum rtrs_srv_link_ev - Server link events
130  * @RTRS_SRV_LINK_EV_CONNECTED:	Connection from client established
131  * @RTRS_SRV_LINK_EV_DISCONNECTED:	Connection was disconnected, all
132  *					connection RTRS resources were freed.
133  */
134 enum rtrs_srv_link_ev {
135 	RTRS_SRV_LINK_EV_CONNECTED,
136 	RTRS_SRV_LINK_EV_DISCONNECTED,
137 };
138 
139 struct rtrs_srv_ops {
140 	/**
141 	 * rdma_ev():		Event notification for RDMA operations
142 	 *			If the callback returns a value != 0, an error
143 	 *			message for the data transfer will be sent to
144 	 *			the client.
145 
146 	 *	@priv:		Private data set by rtrs_srv_set_sess_priv()
147 	 *	@id:		internal RTRS operation id
148 	 *	@data:		Pointer to (bidirectional) rdma memory area:
149 	 *			- in case of %RTRS_SRV_RDMA_EV_RECV contains
150 	 *			data sent by the client
151 	 *			- in case of %RTRS_SRV_RDMA_EV_WRITE_REQ points
152 	 *			to the memory area where the response is to be
153 	 *			written to
154 	 *	@datalen:	Size of the memory area in @data
155 	 *	@usr:		The extra user message sent by the client (%vec)
156 	 *	@usrlen:	Size of the user message
157 	 */
158 	int (*rdma_ev)(void *priv,
159 		       struct rtrs_srv_op *id,
160 		       void *data, size_t datalen, const void *usr,
161 		       size_t usrlen);
162 	/**
163 	 * link_ev():		Events about connectivity state changes
164 	 *			If the callback returns != 0 and the event
165 	 *			%RTRS_SRV_LINK_EV_CONNECTED the corresponding
166 	 *			session will be destroyed.
167 	 *	@sess:		Session
168 	 *	@ev:		event
169 	 *	@priv:		Private data from user if previously set with
170 	 *			rtrs_srv_set_sess_priv()
171 	 */
172 	int (*link_ev)(struct rtrs_srv_sess *sess, enum rtrs_srv_link_ev ev,
173 		       void *priv);
174 };
175 
176 struct rtrs_srv_ctx *rtrs_srv_open(struct rtrs_srv_ops *ops, u16 port);
177 
178 void rtrs_srv_close(struct rtrs_srv_ctx *ctx);
179 
180 bool rtrs_srv_resp_rdma(struct rtrs_srv_op *id, int errno);
181 
182 void rtrs_srv_set_sess_priv(struct rtrs_srv_sess *sess, void *priv);
183 
184 int rtrs_srv_get_path_name(struct rtrs_srv_sess *sess, char *pathname,
185 			   size_t len);
186 
187 int rtrs_srv_get_queue_depth(struct rtrs_srv_sess *sess);
188 
189 int rtrs_addr_to_sockaddr(const char *str, size_t len, u16 port,
190 			  struct rtrs_addr *addr);
191 
192 int sockaddr_to_str(const struct sockaddr *addr, char *buf, size_t len);
193 int rtrs_addr_to_str(const struct rtrs_addr *addr, char *buf, size_t len);
194 #endif
195