[mirror_ubuntu-focal-kernel.git] / net / smc / smc.h

/*
 *  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 */
Commit	Line	Data
ac713874 UB	1	/*
	2	* Shared Memory Communications over RDMA (SMC-R) and RoCE
	3	*
	4	* Definitions for the SMC module (socket related)
	5	*
	6	* Copyright IBM Corp. 2016
	7	*
	8	* Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
	9	*/
	10	#ifndef __SMC_H
	11	#define __SMC_H
	12
	13	#include <linux/socket.h>
	14	#include <linux/types.h>
	15	#include <net/sock.h>
	16
0cfdd8f9 UB	17	#include "smc_ib.h"
0cfdd8f9 UB	18
ac713874 UB	19	#define SMCPROTO_SMC 0 /* SMC protocol */
ac713874 UB	20
a4cf0443 UB	21	#define SMC_MAX_PORTS 2 /* Max # of ports */
a4cf0443 UB	22
ac713874 UB	23	enum smc_state { /* possible states of an SMC socket */
	24	SMC_ACTIVE = 1,
	25	SMC_INIT = 2,
	26	SMC_CLOSED = 7,
	27	SMC_LISTEN = 10,
	28	};
	29
0cfdd8f9 UB	30	struct smc_link_group;
	31
	32	struct smc_connection {
	33	struct rb_node alert_node;
	34	struct smc_link_group lgr; / link group of connection */
	35	u32 alert_token_local; /* unique conn. id */
	36	u8 peer_conn_idx; /* from tcp handshake */
cd6851f3 UB	37	int peer_rmbe_size; /* size of peer rx buffer */
	38	atomic_t peer_rmbe_space;/* remaining free bytes in peer
	39	* rmbe
	40	*/
	41
	42	struct smc_buf_desc sndbuf_desc; / send buffer descriptor */
	43	int sndbuf_size; /* sndbuf size <== sock wmem */
	44	struct smc_buf_desc rmb_desc; / RMBE descriptor */
	45	int rmbe_size; /* RMBE size <== sock rmem */
	46	int rmbe_size_short;/* compressed notation */
0cfdd8f9 UB	47	};
0cfdd8f9 UB	48
ac713874 UB	49	struct smc_sock { /* smc sock container */
	50	struct sock sk;
	51	struct socket clcsock; / internal tcp socket */
0cfdd8f9	52	struct smc_connection conn; /* smc connection */
a046d57d UB	53	struct sockaddr addr; / inet connect address */
	54	struct smc_sock listen_smc; / listen parent */
	55	struct work_struct tcp_listen_work;/* handle tcp socket accepts */
	56	struct work_struct smc_listen_work;/* prepare new accept socket */
	57	struct list_head accept_q; /* sockets to be accepted */
	58	spinlock_t accept_q_lock; /* protects accept_q */
ac713874 UB	59	bool use_fallback; /* fallback to tcp */
	60	};
	61
	62	static inline struct smc_sock smc_sk(const struct sock sk)
	63	{
	64	return (struct smc_sock *)sk;
	65	}
	66
a4cf0443 UB	67	#define SMC_SYSTEMID_LEN 8
	68
	69	extern u8 local_systemid[SMC_SYSTEMID_LEN]; /* unique system identifier */
	70
0cfdd8f9 UB	71	/* convert an u32 value into network byte order, store it into a 3 byte field */
	72	static inline void hton24(u8 *net, u32 host)
	73	{
	74	__be32 t;
	75
	76	t = cpu_to_be32(host);
	77	memcpy(net, ((u8 *)&t) + 1, 3);
	78	}
	79
	80	/* convert a received 3 byte field into host byte order*/
	81	static inline u32 ntoh24(u8 *net)
	82	{
	83	__be32 t = 0;
	84
	85	memcpy(((u8 *)&t) + 1, net, 3);
	86	return be32_to_cpu(t);
	87	}
	88
cd6851f3 UB	89	#define SMC_BUF_MIN_SIZE 16384 /* minimum size of an RMB */
	90
	91	#define SMC_RMBE_SIZES 16 /* number of distinct sizes for an RMBE */
	92	/* theoretically, the RFC states that largest size would be 512K,
	93	* i.e. compressed 5 and thus 6 sizes (0..5), despite
	94	* struct smc_clc_msg_accept_confirm.rmbe_size being a 4 bit value (0..15)
	95	*/
	96
	97	/* convert the RMB size into the compressed notation - minimum 16K.
	98	* In contrast to plain ilog2, this rounds towards the next power of 2,
	99	* so the socket application gets at least its desired sndbuf / rcvbuf size.
	100	*/
	101	static inline u8 smc_compress_bufsize(int size)
	102	{
	103	u8 compressed;
	104
	105	if (size <= SMC_BUF_MIN_SIZE)
	106	return 0;
	107
	108	size = (size - 1) >> 14;
	109	compressed = ilog2(size) + 1;
	110	if (compressed >= SMC_RMBE_SIZES)
	111	compressed = SMC_RMBE_SIZES - 1;
	112	return compressed;
	113	}
	114
	115	/* convert the RMB size from compressed notation into integer */
	116	static inline int smc_uncompress_bufsize(u8 compressed)
	117	{
	118	u32 size;
	119
	120	size = 0x00000001 << (((int)compressed) + 14);
	121	return (int)size;
	122	}
	123
a046d57d UB	124	#ifdef CONFIG_XFRM
	125	static inline bool using_ipsec(struct smc_sock *smc)
	126	{
	127	return (smc->clcsock->sk->sk_policy[0] \|\|
	128	smc->clcsock->sk->sk_policy[1]) ? 1 : 0;
	129	}
	130	#else
	131	static inline bool using_ipsec(struct smc_sock *smc)
	132	{
	133	return 0;
	134	}
	135	#endif
	136
0cfdd8f9 UB	137	struct smc_clc_msg_local;
0cfdd8f9 UB	138
a046d57d UB	139	int smc_netinfo_by_tcpsk(struct socket clcsock, __be32 subnet,
a046d57d UB	140	u8 *prefix_len);
0cfdd8f9 UB	141	void smc_conn_free(struct smc_connection *conn);
	142	int smc_conn_create(struct smc_sock *smc, __be32 peer_in_addr,
	143	struct smc_ib_device *smcibdev, u8 ibport,
	144	struct smc_clc_msg_local *lcl, int srv_first_contact);
a046d57d	145
ac713874	146	#endif /* __SMC_H */