xref: /linux/net/smc/smc.h (revision a05e4c0af490ca7c22fc77120aafebebdeaaf537)
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 	u8			type;
60 } __aligned(1);
61 
62 struct smc_cdc_conn_state_flags {
63 #if defined(__BIG_ENDIAN_BITFIELD)
64 	u8	peer_done_writing : 1;	/* Sending done indicator */
65 	u8	peer_conn_closed : 1;	/* Peer connection closed indicator */
66 	u8	peer_conn_abort : 1;	/* Abnormal close indicator */
67 	u8	reserved : 5;
68 #elif defined(__LITTLE_ENDIAN_BITFIELD)
69 	u8	reserved : 5;
70 	u8	peer_conn_abort : 1;
71 	u8	peer_conn_closed : 1;
72 	u8	peer_done_writing : 1;
73 #endif
74 };
75 
76 struct smc_cdc_producer_flags {
77 #if defined(__BIG_ENDIAN_BITFIELD)
78 	u8	write_blocked : 1;	/* Writing Blocked, no rx buf space */
79 	u8	urg_data_pending : 1;	/* Urgent Data Pending */
80 	u8	urg_data_present : 1;	/* Urgent Data Present */
81 	u8	cons_curs_upd_req : 1;	/* cursor update requested */
82 	u8	failover_validation : 1;/* message replay due to failover */
83 	u8	reserved : 3;
84 #elif defined(__LITTLE_ENDIAN_BITFIELD)
85 	u8	reserved : 3;
86 	u8	failover_validation : 1;
87 	u8	cons_curs_upd_req : 1;
88 	u8	urg_data_present : 1;
89 	u8	urg_data_pending : 1;
90 	u8	write_blocked : 1;
91 #endif
92 };
93 
94 /* in host byte order */
95 union smc_host_cursor {	/* SMC cursor - an offset in an RMBE */
96 	struct {
97 		u16	reserved;
98 		u16	wrap;		/* window wrap sequence number */
99 		u32	count;		/* cursor (= offset) part */
100 	};
101 #ifdef KERNEL_HAS_ATOMIC64
102 	atomic64_t		acurs;	/* for atomic processing */
103 #else
104 	u64			acurs;	/* for atomic processing */
105 #endif
106 } __aligned(8);
107 
108 /* in host byte order, except for flag bitfields in network byte order */
109 struct smc_host_cdc_msg {		/* Connection Data Control message */
110 	struct smc_wr_rx_hdr		common; /* .type = 0xFE */
111 	u8				len;	/* length = 44 */
112 	u16				seqno;	/* connection seq # */
113 	u32				token;	/* alert_token */
114 	union smc_host_cursor		prod;		/* producer cursor */
115 	union smc_host_cursor		cons;		/* consumer cursor,
116 							 * piggy backed "ack"
117 							 */
118 	struct smc_cdc_producer_flags	prod_flags;	/* conn. tx/rx status */
119 	struct smc_cdc_conn_state_flags	conn_state_flags; /* peer conn. status*/
120 	u8				reserved[18];
121 } __aligned(8);
122 
123 enum smc_urg_state {
124 	SMC_URG_VALID	= 1,			/* data present */
125 	SMC_URG_NOTYET	= 2,			/* data pending */
126 	SMC_URG_READ	= 3,			/* data was already read */
127 };
128 
129 struct smc_connection {
130 	struct rb_node		alert_node;
131 	struct smc_link_group	*lgr;		/* link group of connection */
132 	struct smc_link		*lnk;		/* assigned SMC-R link */
133 	u32			alert_token_local; /* unique conn. id */
134 	u8			peer_rmbe_idx;	/* from tcp handshake */
135 	int			peer_rmbe_size;	/* size of peer rx buffer */
136 	atomic_t		peer_rmbe_space;/* remaining free bytes in peer
137 						 * rmbe
138 						 */
139 	int			rtoken_idx;	/* idx to peer RMB rkey/addr */
140 
141 	struct smc_buf_desc	*sndbuf_desc;	/* send buffer descriptor */
142 	struct smc_buf_desc	*rmb_desc;	/* RMBE descriptor */
143 	int			rmbe_size_short;/* compressed notation */
144 	int			rmbe_update_limit;
145 						/* lower limit for consumer
146 						 * cursor update
147 						 */
148 
149 	struct smc_host_cdc_msg	local_tx_ctrl;	/* host byte order staging
150 						 * buffer for CDC msg send
151 						 * .prod cf. TCP snd_nxt
152 						 * .cons cf. TCP sends ack
153 						 */
154 	union smc_host_cursor	local_tx_ctrl_fin;
155 						/* prod crsr - confirmed by peer
156 						 */
157 	union smc_host_cursor	tx_curs_prep;	/* tx - prepared data
158 						 * snd_max..wmem_alloc
159 						 */
160 	union smc_host_cursor	tx_curs_sent;	/* tx - sent data
161 						 * snd_nxt ?
162 						 */
163 	union smc_host_cursor	tx_curs_fin;	/* tx - confirmed by peer
164 						 * snd-wnd-begin ?
165 						 */
166 	atomic_t		sndbuf_space;	/* remaining space in sndbuf */
167 	u16			tx_cdc_seq;	/* sequence # for CDC send */
168 	u16			tx_cdc_seq_fin;	/* sequence # - tx completed */
169 	spinlock_t		send_lock;	/* protect wr_sends */
170 	struct delayed_work	tx_work;	/* retry of smc_cdc_msg_send */
171 	u32			tx_off;		/* base offset in peer rmb */
172 
173 	struct smc_host_cdc_msg	local_rx_ctrl;	/* filled during event_handl.
174 						 * .prod cf. TCP rcv_nxt
175 						 * .cons cf. TCP snd_una
176 						 */
177 	union smc_host_cursor	rx_curs_confirmed; /* confirmed to peer
178 						    * source of snd_una ?
179 						    */
180 	union smc_host_cursor	urg_curs;	/* points at urgent byte */
181 	enum smc_urg_state	urg_state;
182 	bool			urg_tx_pend;	/* urgent data staged */
183 	bool			urg_rx_skip_pend;
184 						/* indicate urgent oob data
185 						 * read, but previous regular
186 						 * data still pending
187 						 */
188 	char			urg_rx_byte;	/* urgent byte */
189 	atomic_t		bytes_to_rcv;	/* arrived data,
190 						 * not yet received
191 						 */
192 	atomic_t		splice_pending;	/* number of spliced bytes
193 						 * pending processing
194 						 */
195 #ifndef KERNEL_HAS_ATOMIC64
196 	spinlock_t		acurs_lock;	/* protect cursors */
197 #endif
198 	struct work_struct	close_work;	/* peer sent some closing */
199 	struct work_struct	abort_work;	/* abort the connection */
200 	struct tasklet_struct	rx_tsklet;	/* Receiver tasklet for SMC-D */
201 	u8			rx_off;		/* receive offset:
202 						 * 0 for SMC-R, 32 for SMC-D
203 						 */
204 	u64			peer_token;	/* SMC-D token of peer */
205 	u8			killed : 1;	/* abnormal termination */
206 	u8			out_of_sync : 1; /* out of sync with peer */
207 };
208 
209 struct smc_sock {				/* smc sock container */
210 	struct sock		sk;
211 	struct socket		*clcsock;	/* internal tcp socket */
212 	void			(*clcsk_data_ready)(struct sock *sk);
213 						/* original data_ready fct. **/
214 	struct smc_connection	conn;		/* smc connection */
215 	struct smc_sock		*listen_smc;	/* listen parent */
216 	struct work_struct	connect_work;	/* handle non-blocking connect*/
217 	struct work_struct	tcp_listen_work;/* handle tcp socket accepts */
218 	struct work_struct	smc_listen_work;/* prepare new accept socket */
219 	struct list_head	accept_q;	/* sockets to be accepted */
220 	spinlock_t		accept_q_lock;	/* protects accept_q */
221 	bool			use_fallback;	/* fallback to tcp */
222 	int			fallback_rsn;	/* reason for fallback */
223 	u32			peer_diagnosis; /* decline reason from peer */
224 	int			sockopt_defer_accept;
225 						/* sockopt TCP_DEFER_ACCEPT
226 						 * value
227 						 */
228 	u8			wait_close_tx_prepared : 1;
229 						/* shutdown wr or close
230 						 * started, waiting for unsent
231 						 * data to be sent
232 						 */
233 	u8			connect_nonblock : 1;
234 						/* non-blocking connect in
235 						 * flight
236 						 */
237 	struct mutex            clcsock_release_lock;
238 						/* protects clcsock of a listen
239 						 * socket
240 						 * */
241 };
242 
243 static inline struct smc_sock *smc_sk(const struct sock *sk)
244 {
245 	return (struct smc_sock *)sk;
246 }
247 
248 extern struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
249 extern struct workqueue_struct	*smc_close_wq;	/* wq for close work */
250 
251 #define SMC_SYSTEMID_LEN		8
252 
253 extern u8	local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
254 
255 #define ntohll(x) be64_to_cpu(x)
256 #define htonll(x) cpu_to_be64(x)
257 
258 /* convert an u32 value into network byte order, store it into a 3 byte field */
259 static inline void hton24(u8 *net, u32 host)
260 {
261 	__be32 t;
262 
263 	t = cpu_to_be32(host);
264 	memcpy(net, ((u8 *)&t) + 1, 3);
265 }
266 
267 /* convert a received 3 byte field into host byte order*/
268 static inline u32 ntoh24(u8 *net)
269 {
270 	__be32 t = 0;
271 
272 	memcpy(((u8 *)&t) + 1, net, 3);
273 	return be32_to_cpu(t);
274 }
275 
276 #ifdef CONFIG_XFRM
277 static inline bool using_ipsec(struct smc_sock *smc)
278 {
279 	return (smc->clcsock->sk->sk_policy[0] ||
280 		smc->clcsock->sk->sk_policy[1]) ? true : false;
281 }
282 #else
283 static inline bool using_ipsec(struct smc_sock *smc)
284 {
285 	return false;
286 }
287 #endif
288 
289 struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
290 void smc_close_non_accepted(struct sock *sk);
291 
292 #endif	/* __SMC_H */
293