xref: /linux/net/smc/smc.h (revision ea8a163e02d6925773129e2dd86e419e491b791d)
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 extern struct proto smc_proto;
33 extern struct proto smc_proto6;
34 
35 #ifdef ATOMIC64_INIT
36 #define KERNEL_HAS_ATOMIC64
37 #endif
38 
39 enum smc_state {		/* possible states of an SMC socket */
40 	SMC_ACTIVE	= 1,
41 	SMC_INIT	= 2,
42 	SMC_CLOSED	= 7,
43 	SMC_LISTEN	= 10,
44 	/* normal close */
45 	SMC_PEERCLOSEWAIT1	= 20,
46 	SMC_PEERCLOSEWAIT2	= 21,
47 	SMC_APPFINCLOSEWAIT	= 24,
48 	SMC_APPCLOSEWAIT1	= 22,
49 	SMC_APPCLOSEWAIT2	= 23,
50 	SMC_PEERFINCLOSEWAIT	= 25,
51 	/* abnormal close */
52 	SMC_PEERABORTWAIT	= 26,
53 	SMC_PROCESSABORT	= 27,
54 };
55 
56 struct smc_link_group;
57 
58 struct smc_wr_rx_hdr {	/* common prefix part of LLC and CDC to demultiplex */
59 	union {
60 		u8 type;
61 #if defined(__BIG_ENDIAN_BITFIELD)
62 		struct {
63 			u8 llc_version:4,
64 			   llc_type:4;
65 		};
66 #elif defined(__LITTLE_ENDIAN_BITFIELD)
67 		struct {
68 			u8 llc_type:4,
69 			   llc_version:4;
70 		};
71 #endif
72 	};
73 } __aligned(1);
74 
75 struct smc_cdc_conn_state_flags {
76 #if defined(__BIG_ENDIAN_BITFIELD)
77 	u8	peer_done_writing : 1;	/* Sending done indicator */
78 	u8	peer_conn_closed : 1;	/* Peer connection closed indicator */
79 	u8	peer_conn_abort : 1;	/* Abnormal close indicator */
80 	u8	reserved : 5;
81 #elif defined(__LITTLE_ENDIAN_BITFIELD)
82 	u8	reserved : 5;
83 	u8	peer_conn_abort : 1;
84 	u8	peer_conn_closed : 1;
85 	u8	peer_done_writing : 1;
86 #endif
87 };
88 
89 struct smc_cdc_producer_flags {
90 #if defined(__BIG_ENDIAN_BITFIELD)
91 	u8	write_blocked : 1;	/* Writing Blocked, no rx buf space */
92 	u8	urg_data_pending : 1;	/* Urgent Data Pending */
93 	u8	urg_data_present : 1;	/* Urgent Data Present */
94 	u8	cons_curs_upd_req : 1;	/* cursor update requested */
95 	u8	failover_validation : 1;/* message replay due to failover */
96 	u8	reserved : 3;
97 #elif defined(__LITTLE_ENDIAN_BITFIELD)
98 	u8	reserved : 3;
99 	u8	failover_validation : 1;
100 	u8	cons_curs_upd_req : 1;
101 	u8	urg_data_present : 1;
102 	u8	urg_data_pending : 1;
103 	u8	write_blocked : 1;
104 #endif
105 };
106 
107 /* in host byte order */
108 union smc_host_cursor {	/* SMC cursor - an offset in an RMBE */
109 	struct {
110 		u16	reserved;
111 		u16	wrap;		/* window wrap sequence number */
112 		u32	count;		/* cursor (= offset) part */
113 	};
114 #ifdef KERNEL_HAS_ATOMIC64
115 	atomic64_t		acurs;	/* for atomic processing */
116 #else
117 	u64			acurs;	/* for atomic processing */
118 #endif
119 } __aligned(8);
120 
121 /* in host byte order, except for flag bitfields in network byte order */
122 struct smc_host_cdc_msg {		/* Connection Data Control message */
123 	struct smc_wr_rx_hdr		common; /* .type = 0xFE */
124 	u8				len;	/* length = 44 */
125 	u16				seqno;	/* connection seq # */
126 	u32				token;	/* alert_token */
127 	union smc_host_cursor		prod;		/* producer cursor */
128 	union smc_host_cursor		cons;		/* consumer cursor,
129 							 * piggy backed "ack"
130 							 */
131 	struct smc_cdc_producer_flags	prod_flags;	/* conn. tx/rx status */
132 	struct smc_cdc_conn_state_flags	conn_state_flags; /* peer conn. status*/
133 	u8				reserved[18];
134 } __aligned(8);
135 
136 enum smc_urg_state {
137 	SMC_URG_VALID	= 1,			/* data present */
138 	SMC_URG_NOTYET	= 2,			/* data pending */
139 	SMC_URG_READ	= 3,			/* data was already read */
140 };
141 
142 struct smc_connection {
143 	struct rb_node		alert_node;
144 	struct smc_link_group	*lgr;		/* link group of connection */
145 	struct smc_link		*lnk;		/* assigned SMC-R link */
146 	u32			alert_token_local; /* unique conn. id */
147 	u8			peer_rmbe_idx;	/* from tcp handshake */
148 	int			peer_rmbe_size;	/* size of peer rx buffer */
149 	atomic_t		peer_rmbe_space;/* remaining free bytes in peer
150 						 * rmbe
151 						 */
152 	int			rtoken_idx;	/* idx to peer RMB rkey/addr */
153 
154 	struct smc_buf_desc	*sndbuf_desc;	/* send buffer descriptor */
155 	struct smc_buf_desc	*rmb_desc;	/* RMBE descriptor */
156 	int			rmbe_size_short;/* compressed notation */
157 	int			rmbe_update_limit;
158 						/* lower limit for consumer
159 						 * cursor update
160 						 */
161 
162 	struct smc_host_cdc_msg	local_tx_ctrl;	/* host byte order staging
163 						 * buffer for CDC msg send
164 						 * .prod cf. TCP snd_nxt
165 						 * .cons cf. TCP sends ack
166 						 */
167 	union smc_host_cursor	local_tx_ctrl_fin;
168 						/* prod crsr - confirmed by peer
169 						 */
170 	union smc_host_cursor	tx_curs_prep;	/* tx - prepared data
171 						 * snd_max..wmem_alloc
172 						 */
173 	union smc_host_cursor	tx_curs_sent;	/* tx - sent data
174 						 * snd_nxt ?
175 						 */
176 	union smc_host_cursor	tx_curs_fin;	/* tx - confirmed by peer
177 						 * snd-wnd-begin ?
178 						 */
179 	atomic_t		sndbuf_space;	/* remaining space in sndbuf */
180 	u16			tx_cdc_seq;	/* sequence # for CDC send */
181 	u16			tx_cdc_seq_fin;	/* sequence # - tx completed */
182 	spinlock_t		send_lock;	/* protect wr_sends */
183 	struct delayed_work	tx_work;	/* retry of smc_cdc_msg_send */
184 	u32			tx_off;		/* base offset in peer rmb */
185 
186 	struct smc_host_cdc_msg	local_rx_ctrl;	/* filled during event_handl.
187 						 * .prod cf. TCP rcv_nxt
188 						 * .cons cf. TCP snd_una
189 						 */
190 	union smc_host_cursor	rx_curs_confirmed; /* confirmed to peer
191 						    * source of snd_una ?
192 						    */
193 	union smc_host_cursor	urg_curs;	/* points at urgent byte */
194 	enum smc_urg_state	urg_state;
195 	bool			urg_tx_pend;	/* urgent data staged */
196 	bool			urg_rx_skip_pend;
197 						/* indicate urgent oob data
198 						 * read, but previous regular
199 						 * data still pending
200 						 */
201 	char			urg_rx_byte;	/* urgent byte */
202 	atomic_t		bytes_to_rcv;	/* arrived data,
203 						 * not yet received
204 						 */
205 	atomic_t		splice_pending;	/* number of spliced bytes
206 						 * pending processing
207 						 */
208 #ifndef KERNEL_HAS_ATOMIC64
209 	spinlock_t		acurs_lock;	/* protect cursors */
210 #endif
211 	struct work_struct	close_work;	/* peer sent some closing */
212 	struct work_struct	abort_work;	/* abort the connection */
213 	struct tasklet_struct	rx_tsklet;	/* Receiver tasklet for SMC-D */
214 	u8			rx_off;		/* receive offset:
215 						 * 0 for SMC-R, 32 for SMC-D
216 						 */
217 	u64			peer_token;	/* SMC-D token of peer */
218 	u8			killed : 1;	/* abnormal termination */
219 	u8			out_of_sync : 1; /* out of sync with peer */
220 };
221 
222 struct smc_sock {				/* smc sock container */
223 	struct sock		sk;
224 	struct socket		*clcsock;	/* internal tcp socket */
225 	void			(*clcsk_data_ready)(struct sock *sk);
226 						/* original data_ready fct. **/
227 	struct smc_connection	conn;		/* smc connection */
228 	struct smc_sock		*listen_smc;	/* listen parent */
229 	struct work_struct	connect_work;	/* handle non-blocking connect*/
230 	struct work_struct	tcp_listen_work;/* handle tcp socket accepts */
231 	struct work_struct	smc_listen_work;/* prepare new accept socket */
232 	struct list_head	accept_q;	/* sockets to be accepted */
233 	spinlock_t		accept_q_lock;	/* protects accept_q */
234 	bool			use_fallback;	/* fallback to tcp */
235 	int			fallback_rsn;	/* reason for fallback */
236 	u32			peer_diagnosis; /* decline reason from peer */
237 	int			sockopt_defer_accept;
238 						/* sockopt TCP_DEFER_ACCEPT
239 						 * value
240 						 */
241 	u8			wait_close_tx_prepared : 1;
242 						/* shutdown wr or close
243 						 * started, waiting for unsent
244 						 * data to be sent
245 						 */
246 	u8			connect_nonblock : 1;
247 						/* non-blocking connect in
248 						 * flight
249 						 */
250 	struct mutex            clcsock_release_lock;
251 						/* protects clcsock of a listen
252 						 * socket
253 						 * */
254 };
255 
256 static inline struct smc_sock *smc_sk(const struct sock *sk)
257 {
258 	return (struct smc_sock *)sk;
259 }
260 
261 extern struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
262 extern struct workqueue_struct	*smc_close_wq;	/* wq for close work */
263 
264 #define SMC_SYSTEMID_LEN		8
265 
266 extern u8	local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
267 
268 #define ntohll(x) be64_to_cpu(x)
269 #define htonll(x) cpu_to_be64(x)
270 
271 /* convert an u32 value into network byte order, store it into a 3 byte field */
272 static inline void hton24(u8 *net, u32 host)
273 {
274 	__be32 t;
275 
276 	t = cpu_to_be32(host);
277 	memcpy(net, ((u8 *)&t) + 1, 3);
278 }
279 
280 /* convert a received 3 byte field into host byte order*/
281 static inline u32 ntoh24(u8 *net)
282 {
283 	__be32 t = 0;
284 
285 	memcpy(((u8 *)&t) + 1, net, 3);
286 	return be32_to_cpu(t);
287 }
288 
289 #ifdef CONFIG_XFRM
290 static inline bool using_ipsec(struct smc_sock *smc)
291 {
292 	return (smc->clcsock->sk->sk_policy[0] ||
293 		smc->clcsock->sk->sk_policy[1]) ? true : false;
294 }
295 #else
296 static inline bool using_ipsec(struct smc_sock *smc)
297 {
298 	return false;
299 }
300 #endif
301 
302 struct smc_gidlist;
303 
304 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
305 void smc_close_non_accepted(struct sock *sk);
306 void smc_fill_gid_list(struct smc_link_group *lgr,
307 		       struct smc_gidlist *gidlist,
308 		       struct smc_ib_device *known_dev, u8 *known_gid);
309 
310 #endif	/* __SMC_H */
311