drivers/nvme/host/fabrics.h

   1 /*
   2  * NVMe over Fabrics common host code.
   3  * Copyright (c) 2015-2016 HGST, a Western Digital Company.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  */
  14 #ifndef _NVME_FABRICS_H
  15 #define _NVME_FABRICS_H 1
  16
  17 #include <linux/in.h>
  18 #include <linux/inet.h>
  19
  20 #define NVMF_MIN_QUEUE_SIZE     16
  21 #define NVMF_MAX_QUEUE_SIZE     1024
  22 #define NVMF_DEF_QUEUE_SIZE     128
  23 #define NVMF_DEF_RECONNECT_DELAY        10
  24
  25 /*
  26  * Define a host as seen by the target.  We allocate one at boot, but also
  27  * allow the override it when creating controllers.  This is both to provide
  28  * persistence of the Host NQN over multiple boots, and to allow using
  29  * multiple ones, for example in a container scenario.  Because we must not
  30  * use different Host NQNs with the same Host ID we generate a Host ID and
  31  * use this structure to keep track of the relation between the two.
  32  */
  33 struct nvmf_host {
  34         struct kref             ref;
  35         struct list_head        list;
  36         char                    nqn[NVMF_NQN_SIZE];
  37         uuid_be                 id;
  38 };
  39
  40 /**
  41  * enum nvmf_parsing_opts - used to define the sysfs parsing options used.
  42  */
  43 enum {
  44         NVMF_OPT_ERR            = 0,
  45         NVMF_OPT_TRANSPORT      = 1 << 0,
  46         NVMF_OPT_NQN            = 1 << 1,
  47         NVMF_OPT_TRADDR         = 1 << 2,
  48         NVMF_OPT_TRSVCID        = 1 << 3,
  49         NVMF_OPT_QUEUE_SIZE     = 1 << 4,
  50         NVMF_OPT_NR_IO_QUEUES   = 1 << 5,
  51         NVMF_OPT_TL_RETRY_COUNT = 1 << 6,
  52         NVMF_OPT_KATO           = 1 << 7,
  53         NVMF_OPT_HOSTNQN        = 1 << 8,
  54         NVMF_OPT_RECONNECT_DELAY = 1 << 9,
  55 };
  56
  57 /**
  58  * struct nvmf_ctrl_options - Used to hold the options specified
  59  *                            with the parsing opts enum.
  60  * @mask:       Used by the fabrics library to parse through sysfs options
  61  *              on adding a NVMe controller.
  62  * @transport:  Holds the fabric transport "technology name" (for a lack of
  63  *              better description) that will be used by an NVMe controller
  64  *              being added.
  65  * @subsysnqn:  Hold the fully qualified NQN subystem name (format defined
  66  *              in the NVMe specification, "NVMe Qualified Names").
  67  * @traddr:     network address that will be used by the host to communicate
  68  *              to the added NVMe controller.
  69  * @trsvcid:    network port used for host-controller communication.
  70  * @queue_size: Number of IO queue elements.
  71  * @nr_io_queues: Number of controller IO queues that will be established.
  72  * @reconnect_delay: Time between two consecutive reconnect attempts.
  73  * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
  74  * @kato:       Keep-alive timeout.
  75  * @host:       Virtual NVMe host, contains the NQN and Host ID.
  76  */
  77 struct nvmf_ctrl_options {
  78         unsigned                mask;
  79         char                    *transport;
  80         char                    *subsysnqn;
  81         char                    *traddr;
  82         char                    *trsvcid;
  83         size_t                  queue_size;
  84         unsigned int            nr_io_queues;
  85         unsigned int            reconnect_delay;
  86         bool                    discovery_nqn;
  87         unsigned int            kato;
  88         struct nvmf_host        *host;
  89 };
  90
  91 /*
  92  * struct nvmf_transport_ops - used to register a specific
  93  *                             fabric implementation of NVMe fabrics.
  94  * @entry:              Used by the fabrics library to add the new
  95  *                      registration entry to its linked-list internal tree.
  96  * @name:               Name of the NVMe fabric driver implementation.
  97  * @required_opts:      sysfs command-line options that must be specified
  98  *                      when adding a new NVMe controller.
  99  * @allowed_opts:       sysfs command-line options that can be specified
 100  *                      when adding a new NVMe controller.
 101  * @create_ctrl():      function pointer that points to a non-NVMe
 102  *                      implementation-specific fabric technology
 103  *                      that would go into starting up that fabric
 104  *                      for the purpose of conneciton to an NVMe controller
 105  *                      using that fabric technology.
 106  *
 107  * Notes:
 108  *      1. At minimum, 'required_opts' and 'allowed_opts' should
 109  *         be set to the same enum parsing options defined earlier.
 110  *      2. create_ctrl() must be defined (even if it does nothing)
 111  */
 112 struct nvmf_transport_ops {
 113         struct list_head        entry;
 114         const char              *name;
 115         int                     required_opts;
 116         int                     allowed_opts;
 117         struct nvme_ctrl        *(*create_ctrl)(struct device *dev,
 118                                         struct nvmf_ctrl_options *opts);
 119 };
 120
 121 int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
 122 int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
 123 int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
 124 int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
 125 int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
 126 void nvmf_register_transport(struct nvmf_transport_ops *ops);
 127 void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
 128 void nvmf_free_options(struct nvmf_ctrl_options *opts);
 129 const char *nvmf_get_subsysnqn(struct nvme_ctrl *ctrl);
 130 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
 131
 132 #endif /* _NVME_FABRICS_H */