xref: /linux/net/smc/smc.h (revision c79c3c34f75d72a066e292b10aa50fc758c97c89)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  Definitions for the SMC module (socket related)
6  *
7  *  Copyright IBM Corp. 2016
8  *
9  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
10  */
11 #ifndef __SMC_H
12 #define __SMC_H
13 
14 #include <linux/socket.h>
15 #include <linux/types.h>
16 #include <linux/compiler.h> /* __aligned */
17 #include <net/sock.h>
18 
19 #include "smc_ib.h"
20 
21 #define SMC_V1		1		/* SMC version V1 */
22 #define SMC_V2		2		/* SMC version V2 */
23 #define SMC_RELEASE	0
24 
25 #define SMCPROTO_SMC		0	/* SMC protocol, IPv4 */
26 #define SMCPROTO_SMC6		1	/* SMC protocol, IPv6 */
27 
28 #define SMC_MAX_ISM_DEVS	8	/* max # of proposed non-native ISM
29 					 * devices
30 					 */
31 
32 #define SMC_MAX_HOSTNAME_LEN	32
33 #define SMC_MAX_EID_LEN		32
34 
35 extern struct proto smc_proto;
36 extern struct proto smc_proto6;
37 
38 #ifdef ATOMIC64_INIT
39 #define KERNEL_HAS_ATOMIC64
40 #endif
41 
42 enum smc_state {		/* possible states of an SMC socket */
43 	SMC_ACTIVE	= 1,
44 	SMC_INIT	= 2,
45 	SMC_CLOSED	= 7,
46 	SMC_LISTEN	= 10,
47 	/* normal close */
48 	SMC_PEERCLOSEWAIT1	= 20,
49 	SMC_PEERCLOSEWAIT2	= 21,
50 	SMC_APPFINCLOSEWAIT	= 24,
51 	SMC_APPCLOSEWAIT1	= 22,
52 	SMC_APPCLOSEWAIT2	= 23,
53 	SMC_PEERFINCLOSEWAIT	= 25,
54 	/* abnormal close */
55 	SMC_PEERABORTWAIT	= 26,
56 	SMC_PROCESSABORT	= 27,
57 };
58 
59 struct smc_link_group;
60 
61 struct smc_wr_rx_hdr {	/* common prefix part of LLC and CDC to demultiplex */
62 	u8			type;
63 } __aligned(1);
64 
65 struct smc_cdc_conn_state_flags {
66 #if defined(__BIG_ENDIAN_BITFIELD)
67 	u8	peer_done_writing : 1;	/* Sending done indicator */
68 	u8	peer_conn_closed : 1;	/* Peer connection closed indicator */
69 	u8	peer_conn_abort : 1;	/* Abnormal close indicator */
70 	u8	reserved : 5;
71 #elif defined(__LITTLE_ENDIAN_BITFIELD)
72 	u8	reserved : 5;
73 	u8	peer_conn_abort : 1;
74 	u8	peer_conn_closed : 1;
75 	u8	peer_done_writing : 1;
76 #endif
77 };
78 
79 struct smc_cdc_producer_flags {
80 #if defined(__BIG_ENDIAN_BITFIELD)
81 	u8	write_blocked : 1;	/* Writing Blocked, no rx buf space */
82 	u8	urg_data_pending : 1;	/* Urgent Data Pending */
83 	u8	urg_data_present : 1;	/* Urgent Data Present */
84 	u8	cons_curs_upd_req : 1;	/* cursor update requested */
85 	u8	failover_validation : 1;/* message replay due to failover */
86 	u8	reserved : 3;
87 #elif defined(__LITTLE_ENDIAN_BITFIELD)
88 	u8	reserved : 3;
89 	u8	failover_validation : 1;
90 	u8	cons_curs_upd_req : 1;
91 	u8	urg_data_present : 1;
92 	u8	urg_data_pending : 1;
93 	u8	write_blocked : 1;
94 #endif
95 };
96 
97 /* in host byte order */
98 union smc_host_cursor {	/* SMC cursor - an offset in an RMBE */
99 	struct {
100 		u16	reserved;
101 		u16	wrap;		/* window wrap sequence number */
102 		u32	count;		/* cursor (= offset) part */
103 	};
104 #ifdef KERNEL_HAS_ATOMIC64
105 	atomic64_t		acurs;	/* for atomic processing */
106 #else
107 	u64			acurs;	/* for atomic processing */
108 #endif
109 } __aligned(8);
110 
111 /* in host byte order, except for flag bitfields in network byte order */
112 struct smc_host_cdc_msg {		/* Connection Data Control message */
113 	struct smc_wr_rx_hdr		common; /* .type = 0xFE */
114 	u8				len;	/* length = 44 */
115 	u16				seqno;	/* connection seq # */
116 	u32				token;	/* alert_token */
117 	union smc_host_cursor		prod;		/* producer cursor */
118 	union smc_host_cursor		cons;		/* consumer cursor,
119 							 * piggy backed "ack"
120 							 */
121 	struct smc_cdc_producer_flags	prod_flags;	/* conn. tx/rx status */
122 	struct smc_cdc_conn_state_flags	conn_state_flags; /* peer conn. status*/
123 	u8				reserved[18];
124 } __aligned(8);
125 
126 enum smc_urg_state {
127 	SMC_URG_VALID	= 1,			/* data present */
128 	SMC_URG_NOTYET	= 2,			/* data pending */
129 	SMC_URG_READ	= 3,			/* data was already read */
130 };
131 
132 struct smc_connection {
133 	struct rb_node		alert_node;
134 	struct smc_link_group	*lgr;		/* link group of connection */
135 	struct smc_link		*lnk;		/* assigned SMC-R link */
136 	u32			alert_token_local; /* unique conn. id */
137 	u8			peer_rmbe_idx;	/* from tcp handshake */
138 	int			peer_rmbe_size;	/* size of peer rx buffer */
139 	atomic_t		peer_rmbe_space;/* remaining free bytes in peer
140 						 * rmbe
141 						 */
142 	int			rtoken_idx;	/* idx to peer RMB rkey/addr */
143 
144 	struct smc_buf_desc	*sndbuf_desc;	/* send buffer descriptor */
145 	struct smc_buf_desc	*rmb_desc;	/* RMBE descriptor */
146 	int			rmbe_size_short;/* compressed notation */
147 	int			rmbe_update_limit;
148 						/* lower limit for consumer
149 						 * cursor update
150 						 */
151 
152 	struct smc_host_cdc_msg	local_tx_ctrl;	/* host byte order staging
153 						 * buffer for CDC msg send
154 						 * .prod cf. TCP snd_nxt
155 						 * .cons cf. TCP sends ack
156 						 */
157 	union smc_host_cursor	local_tx_ctrl_fin;
158 						/* prod crsr - confirmed by peer
159 						 */
160 	union smc_host_cursor	tx_curs_prep;	/* tx - prepared data
161 						 * snd_max..wmem_alloc
162 						 */
163 	union smc_host_cursor	tx_curs_sent;	/* tx - sent data
164 						 * snd_nxt ?
165 						 */
166 	union smc_host_cursor	tx_curs_fin;	/* tx - confirmed by peer
167 						 * snd-wnd-begin ?
168 						 */
169 	atomic_t		sndbuf_space;	/* remaining space in sndbuf */
170 	u16			tx_cdc_seq;	/* sequence # for CDC send */
171 	u16			tx_cdc_seq_fin;	/* sequence # - tx completed */
172 	spinlock_t		send_lock;	/* protect wr_sends */
173 	struct delayed_work	tx_work;	/* retry of smc_cdc_msg_send */
174 	u32			tx_off;		/* base offset in peer rmb */
175 
176 	struct smc_host_cdc_msg	local_rx_ctrl;	/* filled during event_handl.
177 						 * .prod cf. TCP rcv_nxt
178 						 * .cons cf. TCP snd_una
179 						 */
180 	union smc_host_cursor	rx_curs_confirmed; /* confirmed to peer
181 						    * source of snd_una ?
182 						    */
183 	union smc_host_cursor	urg_curs;	/* points at urgent byte */
184 	enum smc_urg_state	urg_state;
185 	bool			urg_tx_pend;	/* urgent data staged */
186 	bool			urg_rx_skip_pend;
187 						/* indicate urgent oob data
188 						 * read, but previous regular
189 						 * data still pending
190 						 */
191 	char			urg_rx_byte;	/* urgent byte */
192 	atomic_t		bytes_to_rcv;	/* arrived data,
193 						 * not yet received
194 						 */
195 	atomic_t		splice_pending;	/* number of spliced bytes
196 						 * pending processing
197 						 */
198 #ifndef KERNEL_HAS_ATOMIC64
199 	spinlock_t		acurs_lock;	/* protect cursors */
200 #endif
201 	struct work_struct	close_work;	/* peer sent some closing */
202 	struct work_struct	abort_work;	/* abort the connection */
203 	struct tasklet_struct	rx_tsklet;	/* Receiver tasklet for SMC-D */
204 	u8			rx_off;		/* receive offset:
205 						 * 0 for SMC-R, 32 for SMC-D
206 						 */
207 	u64			peer_token;	/* SMC-D token of peer */
208 	u8			killed : 1;	/* abnormal termination */
209 	u8			out_of_sync : 1; /* out of sync with peer */
210 };
211 
212 struct smc_sock {				/* smc sock container */
213 	struct sock		sk;
214 	struct socket		*clcsock;	/* internal tcp socket */
215 	void			(*clcsk_data_ready)(struct sock *sk);
216 						/* original data_ready fct. **/
217 	struct smc_connection	conn;		/* smc connection */
218 	struct smc_sock		*listen_smc;	/* listen parent */
219 	struct work_struct	connect_work;	/* handle non-blocking connect*/
220 	struct work_struct	tcp_listen_work;/* handle tcp socket accepts */
221 	struct work_struct	smc_listen_work;/* prepare new accept socket */
222 	struct list_head	accept_q;	/* sockets to be accepted */
223 	spinlock_t		accept_q_lock;	/* protects accept_q */
224 	bool			use_fallback;	/* fallback to tcp */
225 	int			fallback_rsn;	/* reason for fallback */
226 	u32			peer_diagnosis; /* decline reason from peer */
227 	int			sockopt_defer_accept;
228 						/* sockopt TCP_DEFER_ACCEPT
229 						 * value
230 						 */
231 	u8			wait_close_tx_prepared : 1;
232 						/* shutdown wr or close
233 						 * started, waiting for unsent
234 						 * data to be sent
235 						 */
236 	u8			connect_nonblock : 1;
237 						/* non-blocking connect in
238 						 * flight
239 						 */
240 	struct mutex            clcsock_release_lock;
241 						/* protects clcsock of a listen
242 						 * socket
243 						 * */
244 };
245 
246 static inline struct smc_sock *smc_sk(const struct sock *sk)
247 {
248 	return (struct smc_sock *)sk;
249 }
250 
251 extern struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
252 extern struct workqueue_struct	*smc_close_wq;	/* wq for close work */
253 
254 #define SMC_SYSTEMID_LEN		8
255 
256 extern u8	local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
257 
258 #define ntohll(x) be64_to_cpu(x)
259 #define htonll(x) cpu_to_be64(x)
260 
261 /* convert an u32 value into network byte order, store it into a 3 byte field */
262 static inline void hton24(u8 *net, u32 host)
263 {
264 	__be32 t;
265 
266 	t = cpu_to_be32(host);
267 	memcpy(net, ((u8 *)&t) + 1, 3);
268 }
269 
270 /* convert a received 3 byte field into host byte order*/
271 static inline u32 ntoh24(u8 *net)
272 {
273 	__be32 t = 0;
274 
275 	memcpy(((u8 *)&t) + 1, net, 3);
276 	return be32_to_cpu(t);
277 }
278 
279 #ifdef CONFIG_XFRM
280 static inline bool using_ipsec(struct smc_sock *smc)
281 {
282 	return (smc->clcsock->sk->sk_policy[0] ||
283 		smc->clcsock->sk->sk_policy[1]) ? true : false;
284 }
285 #else
286 static inline bool using_ipsec(struct smc_sock *smc)
287 {
288 	return false;
289 }
290 #endif
291 
292 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
293 void smc_close_non_accepted(struct sock *sk);
294 
295 #endif	/* __SMC_H */
296