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/*
* 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 <net/sock.h>
#include "smc_ib.h"
#define SMCPROTO_SMC 0 /* SMC protocol */
#define SMC_MAX_PORTS 2 /* Max # of ports */
enum smc_state { /* possible states of an SMC socket */
SMC_ACTIVE = 1,
SMC_INIT = 2,
SMC_CLOSED = 7,
SMC_LISTEN = 10,
};
struct smc_link_group;
struct smc_connection {
struct rb_node alert_node;
struct smc_link_group *lgr; /* link group of connection */
u32 alert_token_local; /* unique conn. id */
u8 peer_conn_idx; /* from tcp handshake */
int peer_rmbe_size; /* size of peer rx buffer */
atomic_t peer_rmbe_space;/* remaining free bytes in peer
* rmbe
*/
struct smc_buf_desc *sndbuf_desc; /* send buffer descriptor */
int sndbuf_size; /* sndbuf size <== sock wmem */
struct smc_buf_desc *rmb_desc; /* RMBE descriptor */
int rmbe_size; /* RMBE size <== sock rmem */
int rmbe_size_short;/* compressed notation */
};
struct smc_sock { /* smc sock container */
struct sock sk;
struct socket *clcsock; /* internal tcp socket */
struct smc_connection conn; /* smc connection */
struct sockaddr *addr; /* inet connect address */
struct smc_sock *listen_smc; /* listen parent */
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 */
};
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);
}
#define SMC_BUF_MIN_SIZE 16384 /* minimum size of an RMB */
#define SMC_RMBE_SIZES 16 /* number of distinct sizes for an RMBE */
/* theoretically, the RFC states that largest size would be 512K,
* i.e. compressed 5 and thus 6 sizes (0..5), despite
* struct smc_clc_msg_accept_confirm.rmbe_size being a 4 bit value (0..15)
*/
/* convert the RMB size into the compressed notation - minimum 16K.
* In contrast to plain ilog2, this rounds towards the next power of 2,
* so the socket application gets at least its desired sndbuf / rcvbuf size.
*/
static inline u8 smc_compress_bufsize(int size)
{
u8 compressed;
if (size <= SMC_BUF_MIN_SIZE)
return 0;
size = (size - 1) >> 14;
compressed = ilog2(size) + 1;
if (compressed >= SMC_RMBE_SIZES)
compressed = SMC_RMBE_SIZES - 1;
return compressed;
}
/* convert the RMB size from compressed notation into integer */
static inline int smc_uncompress_bufsize(u8 compressed)
{
u32 size;
size = 0x00000001 << (((int)compressed) + 14);
return (int)size;
}
#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]) ? 1 : 0;
}
#else
static inline bool using_ipsec(struct smc_sock *smc)
{
return 0;
}
#endif
struct smc_clc_msg_local;
int smc_netinfo_by_tcpsk(struct socket *clcsock, __be32 *subnet,
u8 *prefix_len);
void smc_conn_free(struct smc_connection *conn);
int smc_conn_create(struct smc_sock *smc, __be32 peer_in_addr,
struct smc_ib_device *smcibdev, u8 ibport,
struct smc_clc_msg_local *lcl, int srv_first_contact);
#endif /* __SMC_H */
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