/* SPDX-License-Identifier: GPL-2.0 */
/*
* Shared Memory Communications over RDMA (SMC-R) and RoCE
*
* Definitions for the SMC module (socket related)
*
* Copyright IBM Corp. 2016
*
* Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
*/
#ifndef __SMC_H
#define __SMC_H
#include <linux/socket.h>
#include <linux/types.h>
#include <linux/compiler.h> /* __aligned */
#include <net/sock.h>
#include "smc_ib.h"
#define SMCPROTO_SMC 0 /* SMC protocol, IPv4 */
#define SMCPROTO_SMC6 1 /* SMC protocol, IPv6 */
extern struct proto smc_proto;
extern struct proto smc_proto6;
#ifdef ATOMIC64_INIT
#define KERNEL_HAS_ATOMIC64
#endif
enum smc_state { /* possible states of an SMC socket */
SMC_ACTIVE = 1,
SMC_INIT = 2,
SMC_CLOSED = 7,
SMC_LISTEN = 10,
/* normal close */
SMC_PEERCLOSEWAIT1 = 20,
SMC_PEERCLOSEWAIT2 = 21,
SMC_APPFINCLOSEWAIT = 24,
SMC_APPCLOSEWAIT1 = 22,
SMC_APPCLOSEWAIT2 = 23,
SMC_PEERFINCLOSEWAIT = 25,
/* abnormal close */
SMC_PEERABORTWAIT = 26,
SMC_PROCESSABORT = 27,
};
struct smc_link_group;
struct smc_wr_rx_hdr { /* common prefix part of LLC and CDC to demultiplex */
u8 type;
} __aligned(1);
struct smc_cdc_conn_state_flags {
#if defined(__BIG_ENDIAN_BITFIELD)
u8 peer_done_writing : 1; /* Sending done indicator */
u8 peer_conn_closed : 1; /* Peer connection closed indicator */
u8 peer_conn_abort : 1; /* Abnormal close indicator */
u8 reserved : 5;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
u8 reserved : 5;
u8 peer_conn_abort : 1;
u8 peer_conn_closed : 1;
u8 peer_done_writing : 1;
#endif
};
struct smc_cdc_producer_flags {
#if defined(__BIG_ENDIAN_BITFIELD)
u8 write_blocked : 1; /* Writing Blocked, no rx buf space */
u8 urg_data_pending : 1; /* Urgent Data Pending */
u8 urg_data_present : 1; /* Urgent Data Present */
u8 cons_curs_upd_req : 1; /* cursor update requested */
u8 failover_validation : 1;/* message replay due to failover */
u8 reserved : 3;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
u8 reserved : 3;
u8 failover_validation : 1;
u8 cons_curs_upd_req : 1;
u8 urg_data_present : 1;
u8 urg_data_pending : 1;
u8 write_blocked : 1;
#endif
};
/* in host byte order */
union smc_host_cursor { /* SMC cursor - an offset in an RMBE */
struct {
u16 reserved;
u16 wrap; /* window wrap sequence number */
u32 count; /* cursor (= offset) part */
};
#ifdef KERNEL_HAS_ATOMIC64
atomic64_t acurs; /* for atomic processing */
#else
u64 acurs; /* for atomic processing */
#endif
} __aligned(8);
/* in host byte order, except for flag bitfields in network byte order */
struct smc_host_cdc_msg { /* Connection Data Control message */
struct smc_wr_rx_hdr common; /* .type = 0xFE */
u8 len; /* length = 44 */
u16 seqno; /* connection seq # */
u32 token; /* alert_token */
union smc_host_cursor prod; /* producer cursor */
union smc_host_cursor cons; /* consumer cursor,
* piggy backed "ack"
*/
struct smc_cdc_producer_flags prod_flags; /* conn. tx/rx status */
struct smc_cdc_conn_state_flags conn_state_flags; /* peer conn. status*/
u8 reserved[18];
} __aligned(8);
enum smc_urg_state {
SMC_URG_VALID = 1, /* data present */
SMC_URG_NOTYET = 2, /* data pending */
SMC_URG_READ = 3, /* data was already read */
};
struct smc_connection {
struct rb_node alert_node;
struct smc_link_group *lgr; /* link group of connection */
struct smc_link *lnk; /* assigned SMC-R link */
u32 alert_token_local; /* unique conn. id */
u8 peer_rmbe_idx; /* from tcp handshake */
int peer_rmbe_size; /* size of peer rx buffer */
atomic_t peer_rmbe_space;/* remaining free bytes in peer
* rmbe
*/
int rtoken_idx; /* idx to peer RMB rkey/addr */
struct smc_buf_desc *sndbuf_desc; /* send buffer descriptor */
struct smc_buf_desc *rmb_desc; /* RMBE descriptor */
int rmbe_size_short;/* compressed notation */
int rmbe_update_limit;
/* lower limit for consumer
* cursor update
*/
struct smc_host_cdc_msg local_tx_ctrl; /* host byte order staging
* buffer for CDC msg send
* .prod cf. TCP snd_nxt
* .cons cf. TCP sends ack
*/
union smc_host_cursor local_tx_ctrl_fin;
/* prod crsr - confirmed by peer
*/
union smc_host_cursor tx_curs_prep; /* tx - prepared data
* snd_max..wmem_alloc
*/
union smc_host_cursor tx_curs_sent; /* tx - sent data
* snd_nxt ?
*/
union smc_host_cursor tx_curs_fin; /* tx - confirmed by peer
* snd-wnd-begin ?
*/
atomic_t sndbuf_space; /* remaining space in sndbuf */
u16 tx_cdc_seq; /* sequence # for CDC send */
u16 tx_cdc_seq_fin; /* sequence # - tx completed */
spinlock_t send_lock; /* protect wr_sends */
struct delayed_work tx_work; /* retry of smc_cdc_msg_send */
u32 tx_off; /* base offset in peer rmb */
struct smc_host_cdc_msg local_rx_ctrl; /* filled during event_handl.
* .prod cf. TCP rcv_nxt
* .cons cf. TCP snd_una
*/
union smc_host_cursor rx_curs_confirmed; /* confirmed to peer
* source of snd_una ?
*/
union smc_host_cursor urg_curs; /* points at urgent byte */
enum smc_urg_state urg_state;
bool urg_tx_pend; /* urgent data staged */
bool urg_rx_skip_pend;
/* indicate urgent oob data
* read, but previous regular
* data still pending
*/
char urg_rx_byte; /* urgent byte */
atomic_t bytes_to_rcv; /* arrived data,
* not yet received
*/
atomic_t splice_pending; /* number of spliced bytes
* pending processing
*/
#ifndef KERNEL_HAS_ATOMIC64
spinlock_t acurs_lock; /* protect cursors */
#endif
struct work_struct close_work; /* peer sent some closing */
struct work_struct abort_work; /* abort the connection */
struct tasklet_struct rx_tsklet; /* Receiver tasklet for SMC-D */
u8 rx_off; /* receive offset:
* 0 for SMC-R, 32 for SMC-D
*/
u64 peer_token; /* SMC-D token of peer */
u8 killed : 1; /* abnormal termination */
u8 out_of_sync : 1; /* out of sync with peer */
};
struct smc_sock { /* smc sock container */
struct sock sk;
struct socket *clcsock; /* internal tcp socket */
struct smc_connection conn; /* smc connection */
struct smc_sock *listen_smc; /* listen parent */
struct work_struct connect_work; /* handle non-blocking connect*/
struct work_struct tcp_listen_work;/* handle tcp socket accepts */
struct work_struct smc_listen_work;/* prepare new accept socket */
struct list_head accept_q; /* sockets to be accepted */
spinlock_t accept_q_lock; /* protects accept_q */
bool use_fallback; /* fallback to tcp */
int fallback_rsn; /* reason for fallback */
u32 peer_diagnosis; /* decline reason from peer */
int sockopt_defer_accept;
/* sockopt TCP_DEFER_ACCEPT
* value
*/
u8 wait_close_tx_prepared : 1;
/* shutdown wr or close
* started, waiting for unsent
* data to be sent
*/
u8 connect_nonblock : 1;
/* non-blocking connect in
* flight
*/
struct mutex clcsock_release_lock;
/* protects clcsock of a listen
* socket
* */
};
static inline struct smc_sock *smc_sk(const struct sock *sk)
{
return (struct smc_sock *)sk;
}
#define SMC_SYSTEMID_LEN 8
extern u8 local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
/* convert an u32 value into network byte order, store it into a 3 byte field */
static inline void hton24(u8 *net, u32 host)
{
__be32 t;
t = cpu_to_be32(host);
memcpy(net, ((u8 *)&t) + 1, 3);
}
/* convert a received 3 byte field into host byte order*/
static inline u32 ntoh24(u8 *net)
{
__be32 t = 0;
memcpy(((u8 *)&t) + 1, net, 3);
return be32_to_cpu(t);
}
#ifdef CONFIG_XFRM
static inline bool using_ipsec(struct smc_sock *smc)
{
return (smc->clcsock->sk->sk_policy[0] ||
smc->clcsock->sk->sk_policy[1]) ? true : false;
}
#else
static inline bool using_ipsec(struct smc_sock *smc)
{
return false;
}
#endif
struct sock *smc_accept_dequeue(struct sock *parent, struct socket *new_sock);
void smc_close_non_accepted(struct sock *sk);
#endif /* __SMC_H */
