xref: /kernel/linux/linux-5.10/net/smc/smc.h (revision 8c2ecf20)
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
35extern struct proto smc_proto;
36extern struct proto smc_proto6;
37
38#ifdef ATOMIC64_INIT
39#define KERNEL_HAS_ATOMIC64
40#endif
41
42enum 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
59struct smc_link_group;
60
61struct smc_wr_rx_hdr {	/* common prefix part of LLC and CDC to demultiplex */
62	u8			type;
63} __aligned(1);
64
65struct 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
79struct 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 */
98union 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 */
112struct 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
126enum 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
132struct 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	atomic_t		cdc_pend_tx_wr; /* number of pending tx CDC wqe
174						 * - inc when post wqe,
175						 * - dec on polled tx cqe
176						 */
177	wait_queue_head_t	cdc_pend_tx_wq; /* wakeup on no cdc_pend_tx_wr*/
178	struct delayed_work	tx_work;	/* retry of smc_cdc_msg_send */
179	u32			tx_off;		/* base offset in peer rmb */
180
181	struct smc_host_cdc_msg	local_rx_ctrl;	/* filled during event_handl.
182						 * .prod cf. TCP rcv_nxt
183						 * .cons cf. TCP snd_una
184						 */
185	union smc_host_cursor	rx_curs_confirmed; /* confirmed to peer
186						    * source of snd_una ?
187						    */
188	union smc_host_cursor	urg_curs;	/* points at urgent byte */
189	enum smc_urg_state	urg_state;
190	bool			urg_tx_pend;	/* urgent data staged */
191	bool			urg_rx_skip_pend;
192						/* indicate urgent oob data
193						 * read, but previous regular
194						 * data still pending
195						 */
196	char			urg_rx_byte;	/* urgent byte */
197	atomic_t		bytes_to_rcv;	/* arrived data,
198						 * not yet received
199						 */
200	atomic_t		splice_pending;	/* number of spliced bytes
201						 * pending processing
202						 */
203#ifndef KERNEL_HAS_ATOMIC64
204	spinlock_t		acurs_lock;	/* protect cursors */
205#endif
206	struct work_struct	close_work;	/* peer sent some closing */
207	struct work_struct	abort_work;	/* abort the connection */
208	struct tasklet_struct	rx_tsklet;	/* Receiver tasklet for SMC-D */
209	u8			rx_off;		/* receive offset:
210						 * 0 for SMC-R, 32 for SMC-D
211						 */
212	u64			peer_token;	/* SMC-D token of peer */
213	u8			killed : 1;	/* abnormal termination */
214	u8			out_of_sync : 1; /* out of sync with peer */
215};
216
217struct smc_sock {				/* smc sock container */
218	struct sock		sk;
219	struct socket		*clcsock;	/* internal tcp socket */
220	void			(*clcsk_data_ready)(struct sock *sk);
221						/* original data_ready fct. **/
222	struct smc_connection	conn;		/* smc connection */
223	struct smc_sock		*listen_smc;	/* listen parent */
224	struct work_struct	connect_work;	/* handle non-blocking connect*/
225	struct work_struct	tcp_listen_work;/* handle tcp socket accepts */
226	struct work_struct	smc_listen_work;/* prepare new accept socket */
227	struct list_head	accept_q;	/* sockets to be accepted */
228	spinlock_t		accept_q_lock;	/* protects accept_q */
229	bool			use_fallback;	/* fallback to tcp */
230	int			fallback_rsn;	/* reason for fallback */
231	u32			peer_diagnosis; /* decline reason from peer */
232	int			sockopt_defer_accept;
233						/* sockopt TCP_DEFER_ACCEPT
234						 * value
235						 */
236	u8			wait_close_tx_prepared : 1;
237						/* shutdown wr or close
238						 * started, waiting for unsent
239						 * data to be sent
240						 */
241	u8			connect_nonblock : 1;
242						/* non-blocking connect in
243						 * flight
244						 */
245	struct mutex            clcsock_release_lock;
246						/* protects clcsock of a listen
247						 * socket
248						 * */
249};
250
251static inline struct smc_sock *smc_sk(const struct sock *sk)
252{
253	return (struct smc_sock *)sk;
254}
255
256extern struct workqueue_struct	*smc_hs_wq;	/* wq for handshake work */
257extern struct workqueue_struct	*smc_close_wq;	/* wq for close work */
258
259#define SMC_SYSTEMID_LEN		8
260
261extern u8	local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
262
263#define ntohll(x) be64_to_cpu(x)
264#define htonll(x) cpu_to_be64(x)
265
266/* convert an u32 value into network byte order, store it into a 3 byte field */
267static inline void hton24(u8 *net, u32 host)
268{
269	__be32 t;
270
271	t = cpu_to_be32(host);
272	memcpy(net, ((u8 *)&t) + 1, 3);
273}
274
275/* convert a received 3 byte field into host byte order*/
276static inline u32 ntoh24(u8 *net)
277{
278	__be32 t = 0;
279
280	memcpy(((u8 *)&t) + 1, net, 3);
281	return be32_to_cpu(t);
282}
283
284#ifdef CONFIG_XFRM
285static inline bool using_ipsec(struct smc_sock *smc)
286{
287	return (smc->clcsock->sk->sk_policy[0] ||
288		smc->clcsock->sk->sk_policy[1]) ? true : false;
289}
290#else
291static inline bool using_ipsec(struct smc_sock *smc)
292{
293	return false;
294}
295#endif
296
297struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
298void smc_close_non_accepted(struct sock *sk);
299
300static inline void smc_sock_set_flag(struct sock *sk, enum sock_flags flag)
301{
302	set_bit(flag, &sk->sk_flags);
303}
304
305#endif	/* __SMC_H */
306