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  */
  27 struct 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  */
  37 enum {
  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 };
  59
  60 /**
  61  * struct nvmf_ctrl_options - Used to hold the options specified
  62  *                            with the parsing opts enum.
  63  * @mask:       Used by the fabrics library to parse through sysfs options
  64  *              on adding a NVMe controller.
  65  * @transport:  Holds the fabric transport "technology name" (for a lack of
  66  *              better description) that will be used by an NVMe controller
  67  *              being added.
  68  * @subsysnqn:  Hold the fully qualified NQN subystem name (format defined
  69  *              in the NVMe specification, "NVMe Qualified Names").
  70  * @traddr:     The transport-specific TRADDR field for a port on the
  71  *              subsystem which is adding a controller.
  72  * @trsvcid:    The transport-specific TRSVCID field for a port on the
  73  *              subsystem which is adding a controller.
  74  * @host_traddr: A transport-specific field identifying the NVME host port
  75  *              to use for the connection to the controller.
  76  * @queue_size: Number of IO queue elements.
  77  * @nr_io_queues: Number of controller IO queues that will be established.
  78  * @reconnect_delay: Time between two consecutive reconnect attempts.
  79  * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
  80  * @kato:       Keep-alive timeout.
  81  * @host:       Virtual NVMe host, contains the NQN and Host ID.
  82  * @max_reconnects: maximum number of allowed reconnect attempts before removing
  83  *              the controller, (-1) means reconnect forever, zero means remove
  84  *              immediately;
  85  * @disable_sqflow: disable controller sq flow control
  86  * @hdr_digest: generate/verify header digest (TCP)
  87  * @data_digest: generate/verify data digest (TCP)
  88  * @nr_write_queues: number of queues for write I/O
  89  * @nr_poll_queues: number of queues for polling I/O
  90  */
  91 struct nvmf_ctrl_options {
  92         unsigned                mask;
  93         char                    *transport;
  94         char                    *subsysnqn;
  95         char                    *traddr;
  96         char                    *trsvcid;
  97         char                    *host_traddr;
  98         size_t                  queue_size;
  99         unsigned int            nr_io_queues;
 100         unsigned int            reconnect_delay;
 101         bool                    discovery_nqn;
 102         bool                    duplicate_connect;
 103         unsigned int            kato;
 104         struct nvmf_host        *host;
 105         int                     max_reconnects;
 106         bool                    disable_sqflow;
 107         bool                    hdr_digest;
 108         bool                    data_digest;
 109         unsigned int            nr_write_queues;
 110         unsigned int            nr_poll_queues;
 111 };
 112
 113 /*
 114  * struct nvmf_transport_ops - used to register a specific
 115  *                             fabric implementation of NVMe fabrics.
 116  * @entry:              Used by the fabrics library to add the new
 117  *                      registration entry to its linked-list internal tree.
 118  * @module:             Transport module reference
 119  * @name:               Name of the NVMe fabric driver implementation.
 120  * @required_opts:      sysfs command-line options that must be specified
 121  *                      when adding a new NVMe controller.
 122  * @allowed_opts:       sysfs command-line options that can be specified
 123  *                      when adding a new NVMe controller.
 124  * @create_ctrl():      function pointer that points to a non-NVMe
 125  *                      implementation-specific fabric technology
 126  *                      that would go into starting up that fabric
 127  *                      for the purpose of conneciton to an NVMe controller
 128  *                      using that fabric technology.
 129  *
 130  * Notes:
 131  *      1. At minimum, 'required_opts' and 'allowed_opts' should
 132  *         be set to the same enum parsing options defined earlier.
 133  *      2. create_ctrl() must be defined (even if it does nothing)
 134  *      3. struct nvmf_transport_ops must be statically allocated in the
 135  *         modules .bss section so that a pure module_get on @module
 136  *         prevents the memory from beeing freed.
 137  */
 138 struct nvmf_transport_ops {
 139         struct list_head        entry;
 140         struct module           *module;
 141         const char              *name;
 142         int                     required_opts;
 143         int                     allowed_opts;
 144         struct nvme_ctrl        *(*create_ctrl)(struct device *dev,
 145                                         struct nvmf_ctrl_options *opts);
 146 };
 147
 148 static inline bool
 149 nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
 150                         struct nvmf_ctrl_options *opts)
 151 {
 152         if (ctrl->state == NVME_CTRL_DELETING ||
 153             ctrl->state == NVME_CTRL_DEAD ||
 154             strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
 155             strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
 156             memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t)))
 157                 return false;
 158
 159         return true;
 160 }
 161
 162 int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
 163 int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
 164 int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
 165 int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
 166 int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid, bool poll);
 167 int nvmf_register_transport(struct nvmf_transport_ops *ops);
 168 void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
 169 void nvmf_free_options(struct nvmf_ctrl_options *opts);
 170 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
 171 bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
 172 blk_status_t nvmf_fail_nonready_command(struct nvme_ctrl *ctrl,
 173                 struct request *rq);
 174 bool __nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
 175                 bool queue_live);
 176 bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
 177                 struct nvmf_ctrl_options *opts);
 178
 179 static inline bool nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
 180                 bool queue_live)
 181 {
 182         if (likely(ctrl->state == NVME_CTRL_LIVE ||
 183                    ctrl->state == NVME_CTRL_ADMIN_ONLY))
 184                 return true;
 185         return __nvmf_check_ready(ctrl, rq, queue_live);
 186 }
 187
 188 #endif /* _NVME_FABRICS_H */