/* SPDX-License-Identifier: GPL-2.0 */
/*
 * NVMe over Fabrics TCP protocol header.
 * Copyright (c) 2018 Lightbits Labs. All rights reserved.
 */

#ifndef _LINUX_NVME_TCP_H
#define _LINUX_NVME_TCP_H

#include <linux/nvme.h>

#define NVME_TCP_DISC_PORT      8009
#define NVME_TCP_ADMIN_CCSZ     SZ_8K
#define NVME_TCP_DIGEST_LENGTH  4
#define NVME_TCP_MIN_MAXH2CDATA 4096
#define NVME_TCP_MIN_C2HTERM_PLEN       24
#define NVME_TCP_MAX_C2HTERM_PLEN       152

enum nvme_tcp_pfv {
        NVME_TCP_PFV_1_0 = 0x0,
};

enum nvme_tcp_tls_cipher {
        NVME_TCP_TLS_CIPHER_INVALID     = 0,
        NVME_TCP_TLS_CIPHER_SHA256      = 1,
        NVME_TCP_TLS_CIPHER_SHA384      = 2,
};

enum nvme_tcp_fatal_error_status {
        NVME_TCP_FES_INVALID_PDU_HDR            = 0x01,
        NVME_TCP_FES_PDU_SEQ_ERR                = 0x02,
        NVME_TCP_FES_HDR_DIGEST_ERR             = 0x03,
        NVME_TCP_FES_DATA_OUT_OF_RANGE          = 0x04,
        NVME_TCP_FES_R2T_LIMIT_EXCEEDED         = 0x05,
        NVME_TCP_FES_DATA_LIMIT_EXCEEDED        = 0x05,
        NVME_TCP_FES_UNSUPPORTED_PARAM          = 0x06,
};

enum nvme_tcp_digest_option {
        NVME_TCP_HDR_DIGEST_ENABLE      = (1 << 0),
        NVME_TCP_DATA_DIGEST_ENABLE     = (1 << 1),
};

enum nvme_tcp_pdu_type {
        nvme_tcp_icreq          = 0x0,
        nvme_tcp_icresp         = 0x1,
        nvme_tcp_h2c_term       = 0x2,
        nvme_tcp_c2h_term       = 0x3,
        nvme_tcp_cmd            = 0x4,
        nvme_tcp_rsp            = 0x5,
        nvme_tcp_h2c_data       = 0x6,
        nvme_tcp_c2h_data       = 0x7,
        nvme_tcp_r2t            = 0x9,
};

enum nvme_tcp_pdu_flags {
        NVME_TCP_F_HDGST                = (1 << 0),
        NVME_TCP_F_DDGST                = (1 << 1),
        NVME_TCP_F_DATA_LAST            = (1 << 2),
        NVME_TCP_F_DATA_SUCCESS         = (1 << 3),
};

/**
 * struct nvme_tcp_hdr - nvme tcp pdu common header
 *
 * @type:          pdu type
 * @flags:         pdu specific flags
 * @hlen:          pdu header length
 * @pdo:           pdu data offset
 * @plen:          pdu wire byte length
 */
struct nvme_tcp_hdr {
        __u8    type;
        __u8    flags;
        __u8    hlen;
        __u8    pdo;
        __le32  plen;
};

/**
 * struct nvme_tcp_icreq_pdu - nvme tcp initialize connection request pdu
 *
 * @hdr:           pdu generic header
 * @pfv:           pdu version format
 * @hpda:          host pdu data alignment (dwords, 0's based)
 * @digest:        digest types enabled
 * @maxr2t:        maximum r2ts per request supported
 */
struct nvme_tcp_icreq_pdu {
        struct nvme_tcp_hdr     hdr;
        __le16                  pfv;
        __u8                    hpda;
        __u8                    digest;
        __le32                  maxr2t;
        __u8                    rsvd2[112];
};

/**
 * struct nvme_tcp_icresp_pdu - nvme tcp initialize connection response pdu
 *
 * @hdr:           pdu common header
 * @pfv:           pdu version format
 * @cpda:          controller pdu data alignment (dowrds, 0's based)
 * @digest:        digest types enabled
 * @maxdata:       maximum data capsules per r2t supported
 */
struct nvme_tcp_icresp_pdu {
        struct nvme_tcp_hdr     hdr;
        __le16                  pfv;
        __u8                    cpda;
        __u8                    digest;
        __le32                  maxdata;
        __u8                    rsvd[112];
};

/**
 * struct nvme_tcp_term_pdu - nvme tcp terminate connection pdu
 *
 * @hdr:           pdu common header
 * @fes:           fatal error status
 * @fei:           fatal error information
 */
struct nvme_tcp_term_pdu {
        struct nvme_tcp_hdr     hdr;
        __le16                  fes;
        __le16                  feil;
        __le16                  feiu;
        __u8                    rsvd[10];
};

/**
 * struct nvme_tcp_cmd_pdu - nvme tcp command capsule pdu
 *
 * @hdr:           pdu common header
 * @cmd:           nvme command
 */
struct nvme_tcp_cmd_pdu {
        struct nvme_tcp_hdr     hdr;
        struct nvme_command     cmd;
};

/**
 * struct nvme_tcp_rsp_pdu - nvme tcp response capsule pdu
 *
 * @hdr:           pdu common header
 * @hdr:           nvme-tcp generic header
 * @cqe:           nvme completion queue entry
 */
struct nvme_tcp_rsp_pdu {
        struct nvme_tcp_hdr     hdr;
        struct nvme_completion  cqe;
};

/**
 * struct nvme_tcp_r2t_pdu - nvme tcp ready-to-transfer pdu
 *
 * @hdr:           pdu common header
 * @command_id:    nvme command identifier which this relates to
 * @ttag:          transfer tag (controller generated)
 * @r2t_offset:    offset from the start of the command data
 * @r2t_length:    length the host is allowed to send
 */
struct nvme_tcp_r2t_pdu {
        struct nvme_tcp_hdr     hdr;
        __u16                   command_id;
        __u16                   ttag;
        __le32                  r2t_offset;
        __le32                  r2t_length;
        __u8                    rsvd[4];
};

/**
 * struct nvme_tcp_data_pdu - nvme tcp data pdu
 *
 * @hdr:           pdu common header
 * @command_id:    nvme command identifier which this relates to
 * @ttag:          transfer tag (controller generated)
 * @data_offset:   offset from the start of the command data
 * @data_length:   length of the data stream
 */
struct nvme_tcp_data_pdu {
        struct nvme_tcp_hdr     hdr;
        __u16                   command_id;
        __u16                   ttag;
        __le32                  data_offset;
        __le32                  data_length;
        __u8                    rsvd[4];
};

union nvme_tcp_pdu {
        struct nvme_tcp_icreq_pdu       icreq;
        struct nvme_tcp_icresp_pdu      icresp;
        struct nvme_tcp_cmd_pdu         cmd;
        struct nvme_tcp_rsp_pdu         rsp;
        struct nvme_tcp_r2t_pdu         r2t;
        struct nvme_tcp_data_pdu        data;
};

#endif /* _LINUX_NVME_TCP_H */