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