linux/drivers/nvme/host/fabrics.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * NVMe over Fabrics common host code.
   4 * Copyright (c) 2015-2016 HGST, a Western Digital Company.
   5 */
   6#ifndef _NVME_FABRICS_H
   7#define _NVME_FABRICS_H 1
   8
   9#include <linux/in.h>
  10#include <linux/inet.h>
  11
  12#define NVMF_MIN_QUEUE_SIZE     16
  13#define NVMF_MAX_QUEUE_SIZE     1024
  14#define NVMF_DEF_QUEUE_SIZE     128
  15#define NVMF_DEF_RECONNECT_DELAY        10
  16/* default to 600 seconds of reconnect attempts before giving up */
  17#define NVMF_DEF_CTRL_LOSS_TMO          600
  18/* default is -1: the fail fast mechanism is disabled  */
  19#define NVMF_DEF_FAIL_FAST_TMO          -1
  20
  21/*
  22 * Reserved one command for internal usage.  This command is used for sending
  23 * the connect command, as well as for the keep alive command on the admin
  24 * queue once live.
  25 */
  26#define NVMF_RESERVED_TAGS      1
  27
  28/*
  29 * Define a host as seen by the target.  We allocate one at boot, but also
  30 * allow the override it when creating controllers.  This is both to provide
  31 * persistence of the Host NQN over multiple boots, and to allow using
  32 * multiple ones, for example in a container scenario.  Because we must not
  33 * use different Host NQNs with the same Host ID we generate a Host ID and
  34 * use this structure to keep track of the relation between the two.
  35 */
  36struct nvmf_host {
  37        struct kref             ref;
  38        struct list_head        list;
  39        char                    nqn[NVMF_NQN_SIZE];
  40        uuid_t                  id;
  41};
  42
  43/**
  44 * enum nvmf_parsing_opts - used to define the sysfs parsing options used.
  45 */
  46enum {
  47        NVMF_OPT_ERR            = 0,
  48        NVMF_OPT_TRANSPORT      = 1 << 0,
  49        NVMF_OPT_NQN            = 1 << 1,
  50        NVMF_OPT_TRADDR         = 1 << 2,
  51        NVMF_OPT_TRSVCID        = 1 << 3,
  52        NVMF_OPT_QUEUE_SIZE     = 1 << 4,
  53        NVMF_OPT_NR_IO_QUEUES   = 1 << 5,
  54        NVMF_OPT_TL_RETRY_COUNT = 1 << 6,
  55        NVMF_OPT_KATO           = 1 << 7,
  56        NVMF_OPT_HOSTNQN        = 1 << 8,
  57        NVMF_OPT_RECONNECT_DELAY = 1 << 9,
  58        NVMF_OPT_HOST_TRADDR    = 1 << 10,
  59        NVMF_OPT_CTRL_LOSS_TMO  = 1 << 11,
  60        NVMF_OPT_HOST_ID        = 1 << 12,
  61        NVMF_OPT_DUP_CONNECT    = 1 << 13,
  62        NVMF_OPT_DISABLE_SQFLOW = 1 << 14,
  63        NVMF_OPT_HDR_DIGEST     = 1 << 15,
  64        NVMF_OPT_DATA_DIGEST    = 1 << 16,
  65        NVMF_OPT_NR_WRITE_QUEUES = 1 << 17,
  66        NVMF_OPT_NR_POLL_QUEUES = 1 << 18,
  67        NVMF_OPT_TOS            = 1 << 19,
  68        NVMF_OPT_FAIL_FAST_TMO  = 1 << 20,
  69};
  70
  71/**
  72 * struct nvmf_ctrl_options - Used to hold the options specified
  73 *                            with the parsing opts enum.
  74 * @mask:       Used by the fabrics library to parse through sysfs options
  75 *              on adding a NVMe controller.
  76 * @transport:  Holds the fabric transport "technology name" (for a lack of
  77 *              better description) that will be used by an NVMe controller
  78 *              being added.
  79 * @subsysnqn:  Hold the fully qualified NQN subystem name (format defined
  80 *              in the NVMe specification, "NVMe Qualified Names").
  81 * @traddr:     The transport-specific TRADDR field for a port on the
  82 *              subsystem which is adding a controller.
  83 * @trsvcid:    The transport-specific TRSVCID field for a port on the
  84 *              subsystem which is adding a controller.
  85 * @host_traddr: A transport-specific field identifying the NVME host port
  86 *              to use for the connection to the controller.
  87 * @queue_size: Number of IO queue elements.
  88 * @nr_io_queues: Number of controller IO queues that will be established.
  89 * @reconnect_delay: Time between two consecutive reconnect attempts.
  90 * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
  91 * @kato:       Keep-alive timeout.
  92 * @host:       Virtual NVMe host, contains the NQN and Host ID.
  93 * @max_reconnects: maximum number of allowed reconnect attempts before removing
  94 *              the controller, (-1) means reconnect forever, zero means remove
  95 *              immediately;
  96 * @disable_sqflow: disable controller sq flow control
  97 * @hdr_digest: generate/verify header digest (TCP)
  98 * @data_digest: generate/verify data digest (TCP)
  99 * @nr_write_queues: number of queues for write I/O
 100 * @nr_poll_queues: number of queues for polling I/O
 101 * @tos: type of service
 102 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds
 103 */
 104struct nvmf_ctrl_options {
 105        unsigned                mask;
 106        char                    *transport;
 107        char                    *subsysnqn;
 108        char                    *traddr;
 109        char                    *trsvcid;
 110        char                    *host_traddr;
 111        size_t                  queue_size;
 112        unsigned int            nr_io_queues;
 113        unsigned int            reconnect_delay;
 114        bool                    discovery_nqn;
 115        bool                    duplicate_connect;
 116        unsigned int            kato;
 117        struct nvmf_host        *host;
 118        int                     max_reconnects;
 119        bool                    disable_sqflow;
 120        bool                    hdr_digest;
 121        bool                    data_digest;
 122        unsigned int            nr_write_queues;
 123        unsigned int            nr_poll_queues;
 124        int                     tos;
 125        int                     fast_io_fail_tmo;
 126};
 127
 128/*
 129 * struct nvmf_transport_ops - used to register a specific
 130 *                             fabric implementation of NVMe fabrics.
 131 * @entry:              Used by the fabrics library to add the new
 132 *                      registration entry to its linked-list internal tree.
 133 * @module:             Transport module reference
 134 * @name:               Name of the NVMe fabric driver implementation.
 135 * @required_opts:      sysfs command-line options that must be specified
 136 *                      when adding a new NVMe controller.
 137 * @allowed_opts:       sysfs command-line options that can be specified
 138 *                      when adding a new NVMe controller.
 139 * @create_ctrl():      function pointer that points to a non-NVMe
 140 *                      implementation-specific fabric technology
 141 *                      that would go into starting up that fabric
 142 *                      for the purpose of conneciton to an NVMe controller
 143 *                      using that fabric technology.
 144 *
 145 * Notes:
 146 *      1. At minimum, 'required_opts' and 'allowed_opts' should
 147 *         be set to the same enum parsing options defined earlier.
 148 *      2. create_ctrl() must be defined (even if it does nothing)
 149 *      3. struct nvmf_transport_ops must be statically allocated in the
 150 *         modules .bss section so that a pure module_get on @module
 151 *         prevents the memory from beeing freed.
 152 */
 153struct nvmf_transport_ops {
 154        struct list_head        entry;
 155        struct module           *module;
 156        const char              *name;
 157        int                     required_opts;
 158        int                     allowed_opts;
 159        struct nvme_ctrl        *(*create_ctrl)(struct device *dev,
 160                                        struct nvmf_ctrl_options *opts);
 161};
 162
 163static inline bool
 164nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
 165                        struct nvmf_ctrl_options *opts)
 166{
 167        if (ctrl->state == NVME_CTRL_DELETING ||
 168            ctrl->state == NVME_CTRL_DEAD ||
 169            strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
 170            strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
 171            memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t)))
 172                return false;
 173
 174        return true;
 175}
 176
 177int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
 178int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
 179int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
 180int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
 181int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid, bool poll);
 182int nvmf_register_transport(struct nvmf_transport_ops *ops);
 183void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
 184void nvmf_free_options(struct nvmf_ctrl_options *opts);
 185int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
 186bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
 187bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
 188                struct nvmf_ctrl_options *opts);
 189
 190#endif /* _NVME_FABRICS_H */
 191