LXR linux/drivers/nvme/host/fabrics.h

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