/* SPDX-License-Identifier: GPL-2.0 */
/*
 * NVMe over Fabrics common host code.
 * Copyright (c) 2015-2016 HGST, a Western Digital Company.
 */
#ifndef _NVME_FABRICS_H
#define _NVME_FABRICS_H 1

#include <linux/in.h>
#include <linux/inet.h>

#define NVMF_MIN_QUEUE_SIZE     16
#define NVMF_MAX_QUEUE_SIZE     1024
#define NVMF_DEF_QUEUE_SIZE     128
#define NVMF_DEF_RECONNECT_DELAY        10
/* default to 600 seconds of reconnect attempts before giving up */
#define NVMF_DEF_CTRL_LOSS_TMO          600
/* default is -1: the fail fast mechanism is disabled  */
#define NVMF_DEF_FAIL_FAST_TMO          -1

/*
 * Define a host as seen by the target.  We allocate one at boot, but also
 * allow the override it when creating controllers.  This is both to provide
 * persistence of the Host NQN over multiple boots, and to allow using
 * multiple ones, for example in a container scenario.  Because we must not
 * use different Host NQNs with the same Host ID we generate a Host ID and
 * use this structure to keep track of the relation between the two.
 */
struct nvmf_host {
        struct kref             ref;
        struct list_head        list;
        char                    nqn[NVMF_NQN_SIZE];
        uuid_t                  id;
};

/**
 * enum nvmf_parsing_opts - used to define the sysfs parsing options used.
 */
enum {
        NVMF_OPT_ERR            = 0,
        NVMF_OPT_TRANSPORT      = 1 << 0,
        NVMF_OPT_NQN            = 1 << 1,
        NVMF_OPT_TRADDR         = 1 << 2,
        NVMF_OPT_TRSVCID        = 1 << 3,
        NVMF_OPT_QUEUE_SIZE     = 1 << 4,
        NVMF_OPT_NR_IO_QUEUES   = 1 << 5,
        NVMF_OPT_TL_RETRY_COUNT = 1 << 6,
        NVMF_OPT_KATO           = 1 << 7,
        NVMF_OPT_HOSTNQN        = 1 << 8,
        NVMF_OPT_RECONNECT_DELAY = 1 << 9,
        NVMF_OPT_HOST_TRADDR    = 1 << 10,
        NVMF_OPT_CTRL_LOSS_TMO  = 1 << 11,
        NVMF_OPT_HOST_ID        = 1 << 12,
        NVMF_OPT_DUP_CONNECT    = 1 << 13,
        NVMF_OPT_DISABLE_SQFLOW = 1 << 14,
        NVMF_OPT_HDR_DIGEST     = 1 << 15,
        NVMF_OPT_DATA_DIGEST    = 1 << 16,
        NVMF_OPT_NR_WRITE_QUEUES = 1 << 17,
        NVMF_OPT_NR_POLL_QUEUES = 1 << 18,
        NVMF_OPT_TOS            = 1 << 19,
        NVMF_OPT_FAIL_FAST_TMO  = 1 << 20,
        NVMF_OPT_HOST_IFACE     = 1 << 21,
        NVMF_OPT_DISCOVERY      = 1 << 22,
        NVMF_OPT_DHCHAP_SECRET  = 1 << 23,
        NVMF_OPT_DHCHAP_CTRL_SECRET = 1 << 24,
        NVMF_OPT_TLS            = 1 << 25,
        NVMF_OPT_KEYRING        = 1 << 26,
        NVMF_OPT_TLS_KEY        = 1 << 27,
        NVMF_OPT_CONCAT         = 1 << 28,
};

/**
 * struct nvmf_ctrl_options - Used to hold the options specified
 *                            with the parsing opts enum.
 * @mask:       Used by the fabrics library to parse through sysfs options
 *              on adding a NVMe controller.
 * @max_reconnects: maximum number of allowed reconnect attempts before removing
 *              the controller, (-1) means reconnect forever, zero means remove
 *              immediately;
 * @transport:  Holds the fabric transport "technology name" (for a lack of
 *              better description) that will be used by an NVMe controller
 *              being added.
 * @subsysnqn:  Hold the fully qualified NQN subsystem name (format defined
 *              in the NVMe specification, "NVMe Qualified Names").
 * @traddr:     The transport-specific TRADDR field for a port on the
 *              subsystem which is adding a controller.
 * @trsvcid:    The transport-specific TRSVCID field for a port on the
 *              subsystem which is adding a controller.
 * @host_traddr: A transport-specific field identifying the NVME host port
 *     to use for the connection to the controller.
 * @host_iface: A transport-specific field identifying the NVME host
 *     interface to use for the connection to the controller.
 * @queue_size: Number of IO queue elements.
 * @nr_io_queues: Number of controller IO queues that will be established.
 * @reconnect_delay: Time between two consecutive reconnect attempts.
 * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
 * @kato:       Keep-alive timeout.
 * @host:       Virtual NVMe host, contains the NQN and Host ID.
 * @dhchap_secret: DH-HMAC-CHAP secret
 * @dhchap_ctrl_secret: DH-HMAC-CHAP controller secret for bi-directional
 *              authentication
 * @keyring:    Keyring to use for key lookups
 * @tls_key:    TLS key for encrypted connections (TCP)
 * @tls:        Start TLS encrypted connections (TCP)
 * @concat:     Enabled Secure channel concatenation (TCP)
 * @disable_sqflow: disable controller sq flow control
 * @hdr_digest: generate/verify header digest (TCP)
 * @data_digest: generate/verify data digest (TCP)
 * @nr_write_queues: number of queues for write I/O
 * @nr_poll_queues: number of queues for polling I/O
 * @tos: type of service
 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds
 */
struct nvmf_ctrl_options {
        unsigned                mask;
        int                     max_reconnects;
        char                    *transport;
        char                    *subsysnqn;
        char                    *traddr;
        char                    *trsvcid;
        char                    *host_traddr;
        char                    *host_iface;
        size_t                  queue_size;
        unsigned int            nr_io_queues;
        unsigned int            reconnect_delay;
        bool                    discovery_nqn;
        bool                    duplicate_connect;
        unsigned int            kato;
        struct nvmf_host        *host;
        char                    *dhchap_secret;
        char                    *dhchap_ctrl_secret;
        struct key              *keyring;
        struct key              *tls_key;
        bool                    tls;
        bool                    concat;
        bool                    disable_sqflow;
        bool                    hdr_digest;
        bool                    data_digest;
        unsigned int            nr_write_queues;
        unsigned int            nr_poll_queues;
        int                     tos;
        int                     fast_io_fail_tmo;
};

/*
 * struct nvmf_transport_ops - used to register a specific
 *                             fabric implementation of NVMe fabrics.
 * @entry:              Used by the fabrics library to add the new
 *                      registration entry to its linked-list internal tree.
 * @module:             Transport module reference
 * @name:               Name of the NVMe fabric driver implementation.
 * @required_opts:      sysfs command-line options that must be specified
 *                      when adding a new NVMe controller.
 * @allowed_opts:       sysfs command-line options that can be specified
 *                      when adding a new NVMe controller.
 * @create_ctrl():      function pointer that points to a non-NVMe
 *                      implementation-specific fabric technology
 *                      that would go into starting up that fabric
 *                      for the purpose of connection to an NVMe controller
 *                      using that fabric technology.
 *
 * Notes:
 *      1. At minimum, 'required_opts' and 'allowed_opts' should
 *         be set to the same enum parsing options defined earlier.
 *      2. create_ctrl() must be defined (even if it does nothing)
 *      3. struct nvmf_transport_ops must be statically allocated in the
 *         modules .bss section so that a pure module_get on @module
 *         prevents the memory from being freed.
 */
struct nvmf_transport_ops {
        struct list_head        entry;
        struct module           *module;
        const char              *name;
        int                     required_opts;
        int                     allowed_opts;
        struct nvme_ctrl        *(*create_ctrl)(struct device *dev,
                                        struct nvmf_ctrl_options *opts);
};

static inline bool
nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
                        struct nvmf_ctrl_options *opts)
{
        enum nvme_ctrl_state state = nvme_ctrl_state(ctrl);

        if (state == NVME_CTRL_DELETING ||
            state == NVME_CTRL_DELETING_NOIO ||
            state == NVME_CTRL_DEAD ||
            strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
            strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
            !uuid_equal(&opts->host->id, &ctrl->opts->host->id))
                return false;

        return true;
}

static inline char *nvmf_ctrl_subsysnqn(struct nvme_ctrl *ctrl)
{
        if (!ctrl->subsys ||
            !strcmp(ctrl->opts->subsysnqn, NVME_DISC_SUBSYS_NAME))
                return ctrl->opts->subsysnqn;
        return ctrl->subsys->subnqn;
}

static inline void nvmf_complete_timed_out_request(struct request *rq)
{
        if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) {
                nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD;
                blk_mq_complete_request(rq);
        }
}

static inline unsigned int nvmf_nr_io_queues(struct nvmf_ctrl_options *opts)
{
        return min(opts->nr_io_queues, num_online_cpus()) +
                min(opts->nr_write_queues, num_online_cpus()) +
                min(opts->nr_poll_queues, num_online_cpus());
}

static inline unsigned long nvmf_get_virt_boundary(struct nvme_ctrl *ctrl,
                                                   bool is_admin)
{
        return 0;
}

int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
int nvmf_subsystem_reset(struct nvme_ctrl *ctrl);
int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
int nvmf_register_transport(struct nvmf_transport_ops *ops);
void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
void nvmf_free_options(struct nvmf_ctrl_options *opts);
int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
bool nvmf_should_reconnect(struct nvme_ctrl *ctrl, int status);
bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
                struct nvmf_ctrl_options *opts);
void nvmf_set_io_queues(struct nvmf_ctrl_options *opts, u32 nr_io_queues,
                        u32 io_queues[HCTX_MAX_TYPES]);
void nvmf_map_queues(struct blk_mq_tag_set *set, struct nvme_ctrl *ctrl,
                     u32 io_queues[HCTX_MAX_TYPES]);

#endif /* _NVME_FABRICS_H */