/* SPDX-License-Identifier: GPL-2.0 */

  /*
   *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   *
   *  CLC (connection layer control) handshake over initial TCP socket to
   *  prepare for RDMA traffic
   *
   *  Copyright IBM Corp. 2016
   *
   *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
   */
  
  #ifndef _SMC_CLC_H
  #define _SMC_CLC_H
  
  #include <rdma/ib_verbs.h>
  
  #include "smc.h"
  
  #define SMC_CLC_PROPOSAL	0x01
  #define SMC_CLC_ACCEPT		0x02
  #define SMC_CLC_CONFIRM		0x03
  #define SMC_CLC_DECLINE		0x04
  
  /* eye catcher "SMCR" EBCDIC for CLC messages */
  static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
  
  #define SMC_CLC_V1		0x1		/* SMC version                */
  #define CLC_WAIT_TIME		(6 * HZ)	/* max. wait time on clcsock  */
  #define SMC_CLC_DECL_MEM	0x01010000  /* insufficient memory resources  */
  #define SMC_CLC_DECL_TIMEOUT	0x02000000  /* timeout                        */
  #define SMC_CLC_DECL_CNFERR	0x03000000  /* configuration error            */
  #define SMC_CLC_DECL_IPSEC	0x03030000  /* IPsec usage                    */
  #define SMC_CLC_DECL_SYNCERR	0x04000000  /* synchronization error          */
  #define SMC_CLC_DECL_REPLY	0x06000000  /* reply to a received decline    */
  #define SMC_CLC_DECL_INTERR	0x99990000  /* internal error                 */

  #define SMC_CLC_DECL_TCL	0x02040000  /* timeout w4 QP confirm          */
  #define SMC_CLC_DECL_SEND	0x07000000  /* sending problem                */

  
  struct smc_clc_msg_hdr {	/* header1 of clc messages */
  	u8 eyecatcher[4];	/* eye catcher */
  	u8 type;		/* proposal / accept / confirm / decline */
  	__be16 length;
  #if defined(__BIG_ENDIAN_BITFIELD)
  	u8 version : 4,
  	   flag    : 1,
  	   rsvd	   : 3;
  #elif defined(__LITTLE_ENDIAN_BITFIELD)
  	u8 rsvd    : 3,
  	   flag    : 1,
  	   version : 4;
  #endif
  } __packed;			/* format defined in RFC7609 */
  
  struct smc_clc_msg_trail {	/* trailer of clc messages */
  	u8 eyecatcher[4];
  };
  
  struct smc_clc_msg_local {	/* header2 of clc messages */
  	u8 id_for_peer[SMC_SYSTEMID_LEN]; /* unique system id */
  	u8 gid[16];		/* gid of ib_device port */
  	u8 mac[6];		/* mac of ib_device port */
  };
  
  struct smc_clc_msg_proposal {	/* clc proposal message */
  	struct smc_clc_msg_hdr hdr;
  	struct smc_clc_msg_local lcl;
  	__be16 iparea_offset;	/* offset to IP address information area */
  	__be32 outgoing_subnet;	/* subnet mask */
  	u8 prefix_len;		/* number of significant bits in mask */
  	u8 reserved[2];
  	u8 ipv6_prefixes_cnt;	/* number of IPv6 prefixes in prefix array */
  	struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
  } __aligned(4);
  
  struct smc_clc_msg_accept_confirm {	/* clc accept / confirm message */
  	struct smc_clc_msg_hdr hdr;
  	struct smc_clc_msg_local lcl;
  	u8 qpn[3];		/* QP number */
  	__be32 rmb_rkey;	/* RMB rkey */
  	u8 conn_idx;		/* Connection index, which RMBE in RMB */
  	__be32 rmbe_alert_token;/* unique connection id */
  #if defined(__BIG_ENDIAN_BITFIELD)
  	u8 rmbe_size : 4,	/* RMBE buf size (compressed notation) */
  	   qp_mtu   : 4;	/* QP mtu */
  #elif defined(__LITTLE_ENDIAN_BITFIELD)
  	u8 qp_mtu   : 4,
  	   rmbe_size : 4;
  #endif
  	u8 reserved;
  	__be64 rmb_dma_addr;	/* RMB virtual address */
  	u8 reserved2;
  	u8 psn[3];		/* initial packet sequence number */
  	struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
  } __packed;			/* format defined in RFC7609 */
  
  struct smc_clc_msg_decline {	/* clc decline message */
  	struct smc_clc_msg_hdr hdr;
  	u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
  	__be32 peer_diagnosis;	/* diagnosis information */
  	u8 reserved2[4];
  	struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
  } __aligned(4);
  
  struct smc_sock;
  struct smc_ib_device;
  
  int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
  		     u8 expected_type);

  int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info);

  int smc_clc_send_proposal(struct smc_sock *smc, struct smc_ib_device *smcibdev,
  			  u8 ibport);
  int smc_clc_send_confirm(struct smc_sock *smc);

  int smc_clc_send_accept(struct smc_sock *smc, int srv_first_contact);

  
  #endif