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 /* 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  */
  36 struct 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  */
  46 enum {
  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         NVMF_OPT_HOST_IFACE     = 1 << 21,
  70         NVMF_OPT_DISCOVERY      = 1 << 22,
  71         NVMF_OPT_DHCHAP_SECRET  = 1 << 23,
  72         NVMF_OPT_DHCHAP_CTRL_SECRET = 1 << 24,
  73 };
  74
  75 /**
  76  * struct nvmf_ctrl_options - Used to hold the options specified
  77  *                            with the parsing opts enum.
  78  * @mask:       Used by the fabrics library to parse through sysfs options
  79  *              on adding a NVMe controller.
  80  * @transport:  Holds the fabric transport "technology name" (for a lack of
  81  *              better description) that will be used by an NVMe controller
  82  *              being added.
  83  * @subsysnqn:  Hold the fully qualified NQN subystem name (format defined
  84  *              in the NVMe specification, "NVMe Qualified Names").
  85  * @traddr:     The transport-specific TRADDR field for a port on the
  86  *              subsystem which is adding a controller.
  87  * @trsvcid:    The transport-specific TRSVCID field for a port on the
  88  *              subsystem which is adding a controller.
  89  * @host_traddr: A transport-specific field identifying the NVME host port
  90  *     to use for the connection to the controller.
  91  * @host_iface: A transport-specific field identifying the NVME host
  92  *     interface to use for the connection to the controller.
  93  * @queue_size: Number of IO queue elements.
  94  * @nr_io_queues: Number of controller IO queues that will be established.
  95  * @reconnect_delay: Time between two consecutive reconnect attempts.
  96  * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
  97  * @kato:       Keep-alive timeout.
  98  * @host:       Virtual NVMe host, contains the NQN and Host ID.
  99  * @max_reconnects: maximum number of allowed reconnect attempts before removing
 100  *              the controller, (-1) means reconnect forever, zero means remove
 101  *              immediately;
 102  * @dhchap_secret: DH-HMAC-CHAP secret
 103  * @dhchap_ctrl_secret: DH-HMAC-CHAP controller secret for bi-directional
 104  *              authentication
 105  * @disable_sqflow: disable controller sq flow control
 106  * @hdr_digest: generate/verify header digest (TCP)
 107  * @data_digest: generate/verify data digest (TCP)
 108  * @nr_write_queues: number of queues for write I/O
 109  * @nr_poll_queues: number of queues for polling I/O
 110  * @tos: type of service
 111  * @fast_io_fail_tmo: Fast I/O fail timeout in seconds
 112  */
 113 struct nvmf_ctrl_options {
 114         unsigned                mask;
 115         char                    *transport;
 116         char                    *subsysnqn;
 117         char                    *traddr;
 118         char                    *trsvcid;
 119         char                    *host_traddr;
 120         char                    *host_iface;
 121         size_t                  queue_size;
 122         unsigned int            nr_io_queues;
 123         unsigned int            reconnect_delay;
 124         bool                    discovery_nqn;
 125         bool                    duplicate_connect;
 126         unsigned int            kato;
 127         struct nvmf_host        *host;
 128         int                     max_reconnects;
 129         char                    *dhchap_secret;
 130         char                    *dhchap_ctrl_secret;
 131         bool                    disable_sqflow;
 132         bool                    hdr_digest;
 133         bool                    data_digest;
 134         unsigned int            nr_write_queues;
 135         unsigned int            nr_poll_queues;
 136         int                     tos;
 137         int                     fast_io_fail_tmo;
 138 };
 139
 140 /*
 141  * struct nvmf_transport_ops - used to register a specific
 142  *                             fabric implementation of NVMe fabrics.
 143  * @entry:              Used by the fabrics library to add the new
 144  *                      registration entry to its linked-list internal tree.
 145  * @module:             Transport module reference
 146  * @name:               Name of the NVMe fabric driver implementation.
 147  * @required_opts:      sysfs command-line options that must be specified
 148  *                      when adding a new NVMe controller.
 149  * @allowed_opts:       sysfs command-line options that can be specified
 150  *                      when adding a new NVMe controller.
 151  * @create_ctrl():      function pointer that points to a non-NVMe
 152  *                      implementation-specific fabric technology
 153  *                      that would go into starting up that fabric
 154  *                      for the purpose of conneciton to an NVMe controller
 155  *                      using that fabric technology.
 156  *
 157  * Notes:
 158  *      1. At minimum, 'required_opts' and 'allowed_opts' should
 159  *         be set to the same enum parsing options defined earlier.
 160  *      2. create_ctrl() must be defined (even if it does nothing)
 161  *      3. struct nvmf_transport_ops must be statically allocated in the
 162  *         modules .bss section so that a pure module_get on @module
 163  *         prevents the memory from beeing freed.
 164  */
 165 struct nvmf_transport_ops {
 166         struct list_head        entry;
 167         struct module           *module;
 168         const char              *name;
 169         int                     required_opts;
 170         int                     allowed_opts;
 171         struct nvme_ctrl        *(*create_ctrl)(struct device *dev,
 172                                         struct nvmf_ctrl_options *opts);
 173 };
 174
 175 static inline bool
 176 nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
 177                         struct nvmf_ctrl_options *opts)
 178 {
 179         if (ctrl->state == NVME_CTRL_DELETING ||
 180             ctrl->state == NVME_CTRL_DELETING_NOIO ||
 181             ctrl->state == NVME_CTRL_DEAD ||
 182             strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
 183             strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
 184             memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t)))
 185                 return false;
 186
 187         return true;
 188 }
 189
 190 static inline char *nvmf_ctrl_subsysnqn(struct nvme_ctrl *ctrl)
 191 {
 192         if (!ctrl->subsys)
 193                 return ctrl->opts->subsysnqn;
 194         return ctrl->subsys->subnqn;
 195 }
 196
 197 static inline void nvmf_complete_timed_out_request(struct request *rq)
 198 {
 199         if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) {
 200                 nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD;
 201                 blk_mq_complete_request(rq);
 202         }
 203 }
 204
 205 int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
 206 int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
 207 int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
 208 int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
 209 int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
 210 int nvmf_register_transport(struct nvmf_transport_ops *ops);
 211 void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
 212 void nvmf_free_options(struct nvmf_ctrl_options *opts);
 213 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
 214 bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
 215 bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
 216                 struct nvmf_ctrl_options *opts);
 217
 218 #endif /* _NVME_FABRICS_H */