/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2022-2024 Chelsio Communications, Inc.
 * Written by: John Baldwin <jhb@FreeBSD.org>
 */

#ifndef __NVMF_H__
#define __NVMF_H__

#include <sys/ioccom.h>
#ifndef _KERNEL
#include <stdbool.h>
#endif

/*
 * Default settings in Fabrics controllers.  These match values used by the
 * Linux target.
 */
#define NVMF_MAX_IO_ENTRIES     (1024)
#define NVMF_CC_EN_TIMEOUT      (15)    /* In 500ms units */

/* Allows for a 16k data buffer + SQE */
#define NVMF_IOCCSZ             (sizeof(struct nvme_command) + 16 * 1024)
#define NVMF_IORCSZ             (sizeof(struct nvme_completion))

#define NVMF_NN                 (1024)

/*
 * Default settings for Fabrics hosts.  These match values used by
 * Linux.
 */
#define NVMF_DEFAULT_RECONNECT_DELAY    10
#define NVMF_DEFAULT_CONTROLLER_LOSS    600
#define NVMF_DEFAULT_IO_ENTRIES         128

/*
 * (data, size) is the userspace buffer for a packed nvlist.
 *
 * For requests that copyout an nvlist, len is the amount of data
 * copied out to *data.  If size is zero, no data is copied and len is
 * set to the required buffer size.
 */
struct nvmf_ioc_nv {
        void    *data;
        size_t  len;
        size_t  size;
};

/*
 * The fields in a qpair handoff nvlist are:
 *
 * Transport independent:
 *
 * bool         admin
 * bool         sq_flow_control
 * number       qsize
 * number       sqhd
 * number       sqtail                  host only
 *
 * TCP transport:
 *
 * number       fd
 * number       rxpda
 * number       txpda
 * bool         header_digests
 * bool         data_digests
 * number       maxr2t
 * number       maxh2cdata
 * number       max_icd
 */

/*
 * The fields in the nvlist for NVMF_HANDOFF_HOST and
 * NVMF_RECONNECT_HOST are:
 *
 * number                       trtype
 * number                       kato    (optional)
 * number                       reconnect_delay (optional)
 * number                       controller_loss_timeout (optional)
 * qpair handoff nvlist         admin
 * qpair handoff nvlist array   io
 * binary                       cdata   struct nvme_controller_data
 * NVMF_RECONNECT_PARAMS nvlist rparams
 */

/*
 * The fields in the nvlist for NVMF_RECONNECT_PARAMS are:
 *
 * binary                       dle     struct nvme_discovery_log_entry
 * string                       hostnqn
 * number                       num_io_queues
 * number                       kato    (optional)
 * number                       reconnect_delay (optional)
 * number                       controller_loss_timeout (optional)
 * number                       io_qsize
 * bool                         sq_flow_control
 *
 * TCP transport:
 *
 * bool                         header_digests
 * bool                         data_digests
 */

/*
 * The fields in the nvlist for NVMF_CONNECTION_STATUS are:
 *
 * bool                         connected
 * timespec nvlist              last_disconnect
 *  number                      tv_sec
 *  number                      tv_nsec
 */

/*
 * The fields in the nvlist for handing off a controller qpair are:
 *
 * number                       trtype
 * qpair handoff nvlist         params
 * binary                       cmd     struct nvmf_fabric_connect_cmd
 * binary                       data    struct nvmf_fabric_connect_data
 */

/* Operations on /dev/nvmf */
#define NVMF_HANDOFF_HOST       _IOW('n', 200, struct nvmf_ioc_nv)
#define NVMF_DISCONNECT_HOST    _IOW('n', 201, const char *)
#define NVMF_DISCONNECT_ALL     _IO('n', 202)

/* Operations on /dev/nvmeX */
#define NVMF_RECONNECT_PARAMS   _IOWR('n', 203, struct nvmf_ioc_nv)
#define NVMF_RECONNECT_HOST     _IOW('n', 204, struct nvmf_ioc_nv)
#define NVMF_CONNECTION_STATUS  _IOWR('n', 205, struct nvmf_ioc_nv)

#endif /* !__NVMF_H__ */