/*
 * Copyright (c) 2005 Cisco Systems.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * $Id$
 */

#ifndef SCSI_SRP_H
#define SCSI_SRP_H

/*
 * Structures and constants for the SCSI RDMA Protocol (SRP) as
 * defined by the INCITS T10 committee.  This file was written using
 * draft Revision 16a of the SRP standard.
 */

#include <linux/types.h>
#include <scsi/scsi.h>

enum {
        SRP_LOGIN_REQ   = 0x00,
        SRP_TSK_MGMT    = 0x01,
        SRP_CMD         = 0x02,
        SRP_I_LOGOUT    = 0x03,
        SRP_LOGIN_RSP   = 0xc0,
        SRP_RSP         = 0xc1,
        SRP_LOGIN_REJ   = 0xc2,
        SRP_T_LOGOUT    = 0x80,
        SRP_CRED_REQ    = 0x81,
        SRP_AER_REQ     = 0x82,
        SRP_CRED_RSP    = 0x41,
        SRP_AER_RSP     = 0x42
};

enum {
        SRP_BUF_FORMAT_DIRECT   = 1 << 1,
        SRP_BUF_FORMAT_INDIRECT = 1 << 2
};

enum {
        SRP_NO_DATA_DESC        = 0,
        SRP_DATA_DESC_DIRECT    = 1,
        SRP_DATA_DESC_INDIRECT  = 2,
        SRP_DATA_DESC_IMM       = 3,    /* new in SRP2 */
};

enum {
        SRP_TSK_ABORT_TASK      = 0x01,
        SRP_TSK_ABORT_TASK_SET  = 0x02,
        SRP_TSK_CLEAR_TASK_SET  = 0x04,
        SRP_TSK_LUN_RESET       = 0x08,
        SRP_TSK_CLEAR_ACA       = 0x40
};

enum srp_login_rej_reason {
        SRP_LOGIN_REJ_UNABLE_ESTABLISH_CHANNEL          = 0x00010000,
        SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES            = 0x00010001,
        SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE        = 0x00010002,
        SRP_LOGIN_REJ_UNABLE_ASSOCIATE_CHANNEL          = 0x00010003,
        SRP_LOGIN_REJ_UNSUPPORTED_DESCRIPTOR_FMT        = 0x00010004,
        SRP_LOGIN_REJ_MULTI_CHANNEL_UNSUPPORTED         = 0x00010005,
        SRP_LOGIN_REJ_CHANNEL_LIMIT_REACHED             = 0x00010006
};

enum {
        SRP_REV10_IB_IO_CLASS   = 0xff00,
        SRP_REV16A_IB_IO_CLASS  = 0x0100
};

struct srp_direct_buf {
        __be64  va;
        __be32  key;
        __be32  len;
};

/*
 * We need the packed attribute because the SRP spec puts the list of
 * descriptors at an offset of 20, which is not aligned to the size of
 * struct srp_direct_buf.  The whole structure must be packed to avoid
 * having the 20-byte structure padded to 24 bytes on 64-bit architectures.
 */
struct srp_indirect_buf {
        struct srp_direct_buf   table_desc __packed __aligned(4);
        __be32                  len;
        struct srp_direct_buf   desc_list[] __packed __aligned(4);
};

/* Immediate data buffer descriptor as defined in SRP2. */
struct srp_imm_buf {
        __be32  len;
};

/* srp_login_req.flags */
enum {
        SRP_MULTICHAN_SINGLE = 0,
        SRP_MULTICHAN_MULTI  = 1,
        SRP_IMMED_REQUESTED  = 0x80,    /* new in SRP2 */
};

struct srp_login_req {
        u8      opcode;
        u8      reserved1[7];
        u64     tag;
        __be32  req_it_iu_len;
        u8      reserved2[4];
        __be16  req_buf_fmt;
        u8      req_flags;
        u8      reserved3[1];
        __be16  imm_data_offset;        /* new in SRP2 */
        u8      reserved4[2];
        u8      initiator_port_id[16];
        u8      target_port_id[16];
};

/**
 * struct srp_login_req_rdma - RDMA/CM login parameters.
 *
 * RDMA/CM over InfiniBand can only carry 92 - 36 = 56 bytes of private
 * data. The %srp_login_req_rdma structure contains the same information as
 * %srp_login_req but with the reserved data removed.
 */
struct srp_login_req_rdma {
        u64     tag;
        __be16  req_buf_fmt;
        u8      req_flags;
        u8      opcode;
        __be32  req_it_iu_len;
        u8      initiator_port_id[16];
        u8      target_port_id[16];
        __be16  imm_data_offset;
        u8      reserved[6];
};

/* srp_login_rsp.rsp_flags */
enum {
        SRP_LOGIN_RSP_MULTICHAN_NO_CHAN    = 0x0,
        SRP_LOGIN_RSP_MULTICHAN_TERMINATED = 0x1,
        SRP_LOGIN_RSP_MULTICHAN_MAINTAINED = 0x2,
        SRP_LOGIN_RSP_IMMED_SUPP           = 0x80, /* new in SRP2 */
};

/*
 * The SRP spec defines the size of the LOGIN_RSP structure to be 52
 * bytes, so it needs to be packed to avoid having it padded to 56
 * bytes on 64-bit architectures.
 */
struct srp_login_rsp {
        u8      opcode;
        u8      reserved1[3];
        __be32  req_lim_delta;
        u64     tag __packed __aligned(4);
        __be32  max_it_iu_len;
        __be32  max_ti_iu_len;
        __be16  buf_fmt;
        u8      rsp_flags;
        u8      reserved2[25];
};

struct srp_login_rej {
        u8      opcode;
        u8      reserved1[3];
        __be32  reason;
        u64     tag;
        u8      reserved2[8];
        __be16  buf_fmt;
        u8      reserved3[6];
};

struct srp_i_logout {
        u8      opcode;
        u8      reserved[7];
        u64     tag;
};

struct srp_t_logout {
        u8      opcode;
        u8      sol_not;
        u8      reserved[2];
        __be32  reason;
        u64     tag;
};

struct srp_tsk_mgmt {
        u8      opcode;
        u8      sol_not;
        u8      reserved1[6];
        u64     tag;
        u8      reserved2[4];
        struct scsi_lun lun;
        u8      reserved3[2];
        u8      tsk_mgmt_func;
        u8      reserved4;
        u64     task_tag;
        u8      reserved5[8];
};

struct srp_cmd {
        u8      opcode;
        u8      sol_not;
        u8      reserved1[3];
        u8      buf_fmt;
        u8      data_out_desc_cnt;
        u8      data_in_desc_cnt;
        u64     tag;
        u8      reserved2[4];
        struct scsi_lun lun;
        u8      reserved3;
        u8      task_attr;
        u8      reserved4;
        u8      add_cdb_len;
        u8      cdb[16];
        u8      add_data[];
};

enum {
        SRP_RSP_FLAG_RSPVALID = 1 << 0,
        SRP_RSP_FLAG_SNSVALID = 1 << 1,
        SRP_RSP_FLAG_DOOVER   = 1 << 2,
        SRP_RSP_FLAG_DOUNDER  = 1 << 3,
        SRP_RSP_FLAG_DIOVER   = 1 << 4,
        SRP_RSP_FLAG_DIUNDER  = 1 << 5
};

/*
 * The SRP spec defines the size of the RSP structure to be 36 bytes,
 * so it needs to be packed to avoid having it padded to 40 bytes on
 * 64-bit architectures.
 */
struct srp_rsp {
        u8      opcode;
        u8      sol_not;
        u8      reserved1[2];
        __be32  req_lim_delta;
        u64     tag __packed __aligned(4);
        u8      reserved2[2];
        u8      flags;
        u8      status;
        __be32  data_out_res_cnt;
        __be32  data_in_res_cnt;
        __be32  sense_data_len;
        __be32  resp_data_len;
        u8      data[];
};

struct srp_cred_req {
        u8      opcode;
        u8      sol_not;
        u8      reserved[2];
        __be32  req_lim_delta;
        u64     tag;
};

struct srp_cred_rsp {
        u8      opcode;
        u8      reserved[7];
        u64     tag;
};

/*
 * The SRP spec defines the fixed portion of the AER_REQ structure to be
 * 36 bytes, so it needs to be packed to avoid having it padded to 40 bytes
 * on 64-bit architectures.
 */
struct srp_aer_req {
        u8      opcode;
        u8      sol_not;
        u8      reserved[2];
        __be32  req_lim_delta;
        u64     tag __packed __aligned(4);
        u32     reserved2;
        struct scsi_lun lun;
        __be32  sense_data_len;
        u32     reserved3;
        u8      sense_data[];
};

struct srp_aer_rsp {
        u8      opcode;
        u8      reserved[7];
        u64     tag;
};

#endif /* SCSI_SRP_H */