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 /* default to 600 seconds of reconnect attempts before giving up */ 25 #define NVMF_DEF_CTRL_LOSS_TMO 600 26 27 /* 28 * Define a host as seen by the target. We allocate one at boot, but also 29 * allow the override it when creating controllers. This is both to provide 30 * persistence of the Host NQN over multiple boots, and to allow using 31 * multiple ones, for example in a container scenario. Because we must not 32 * use different Host NQNs with the same Host ID we generate a Host ID and 33 * use this structure to keep track of the relation between the two. 34 */ 35 struct nvmf_host { 36 struct kref ref; 37 struct list_head list; 38 char nqn[NVMF_NQN_SIZE]; 39 uuid_t id; 40 }; 41 42 /** 43 * enum nvmf_parsing_opts - used to define the sysfs parsing options used. 44 */ 45 enum { 46 NVMF_OPT_ERR = 0, 47 NVMF_OPT_TRANSPORT = 1 << 0, 48 NVMF_OPT_NQN = 1 << 1, 49 NVMF_OPT_TRADDR = 1 << 2, 50 NVMF_OPT_TRSVCID = 1 << 3, 51 NVMF_OPT_QUEUE_SIZE = 1 << 4, 52 NVMF_OPT_NR_IO_QUEUES = 1 << 5, 53 NVMF_OPT_TL_RETRY_COUNT = 1 << 6, 54 NVMF_OPT_KATO = 1 << 7, 55 NVMF_OPT_HOSTNQN = 1 << 8, 56 NVMF_OPT_RECONNECT_DELAY = 1 << 9, 57 NVMF_OPT_HOST_TRADDR = 1 << 10, 58 NVMF_OPT_CTRL_LOSS_TMO = 1 << 11, 59 NVMF_OPT_HOST_ID = 1 << 12, 60 NVMF_OPT_DUP_CONNECT = 1 << 13, 61 }; 62 63 /** 64 * struct nvmf_ctrl_options - Used to hold the options specified 65 * with the parsing opts enum. 66 * @mask: Used by the fabrics library to parse through sysfs options 67 * on adding a NVMe controller. 68 * @transport: Holds the fabric transport "technology name" (for a lack of 69 * better description) that will be used by an NVMe controller 70 * being added. 71 * @subsysnqn: Hold the fully qualified NQN subystem name (format defined 72 * in the NVMe specification, "NVMe Qualified Names"). 73 * @traddr: The transport-specific TRADDR field for a port on the 74 * subsystem which is adding a controller. 75 * @trsvcid: The transport-specific TRSVCID field for a port on the 76 * subsystem which is adding a controller. 77 * @host_traddr: A transport-specific field identifying the NVME host port 78 * to use for the connection to the controller. 79 * @queue_size: Number of IO queue elements. 80 * @nr_io_queues: Number of controller IO queues that will be established. 81 * @reconnect_delay: Time between two consecutive reconnect attempts. 82 * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN. 83 * @kato: Keep-alive timeout. 84 * @host: Virtual NVMe host, contains the NQN and Host ID. 85 * @max_reconnects: maximum number of allowed reconnect attempts before removing 86 * the controller, (-1) means reconnect forever, zero means remove 87 * immediately; 88 */ 89 struct nvmf_ctrl_options { 90 unsigned mask; 91 char *transport; 92 char *subsysnqn; 93 char *traddr; 94 char *trsvcid; 95 char *host_traddr; 96 size_t queue_size; 97 unsigned int nr_io_queues; 98 unsigned int reconnect_delay; 99 bool discovery_nqn; 100 bool duplicate_connect; 101 unsigned int kato; 102 struct nvmf_host *host; 103 int max_reconnects; 104 }; 105 106 /* 107 * struct nvmf_transport_ops - used to register a specific 108 * fabric implementation of NVMe fabrics. 109 * @entry: Used by the fabrics library to add the new 110 * registration entry to its linked-list internal tree. 111 * @name: Name of the NVMe fabric driver implementation. 112 * @required_opts: sysfs command-line options that must be specified 113 * when adding a new NVMe controller. 114 * @allowed_opts: sysfs command-line options that can be specified 115 * when adding a new NVMe controller. 116 * @create_ctrl(): function pointer that points to a non-NVMe 117 * implementation-specific fabric technology 118 * that would go into starting up that fabric 119 * for the purpose of conneciton to an NVMe controller 120 * using that fabric technology. 121 * 122 * Notes: 123 * 1. At minimum, 'required_opts' and 'allowed_opts' should 124 * be set to the same enum parsing options defined earlier. 125 * 2. create_ctrl() must be defined (even if it does nothing) 126 */ 127 struct nvmf_transport_ops { 128 struct list_head entry; 129 const char *name; 130 int required_opts; 131 int allowed_opts; 132 struct nvme_ctrl *(*create_ctrl)(struct device *dev, 133 struct nvmf_ctrl_options *opts); 134 }; 135 136 static inline bool 137 nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl, 138 struct nvmf_ctrl_options *opts) 139 { 140 if (strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) || 141 strcmp(opts->host->nqn, ctrl->opts->host->nqn) || 142 memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t))) 143 return false; 144 145 return true; 146 } 147 148 int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val); 149 int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val); 150 int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val); 151 int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl); 152 int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid); 153 int nvmf_register_transport(struct nvmf_transport_ops *ops); 154 void nvmf_unregister_transport(struct nvmf_transport_ops *ops); 155 void nvmf_free_options(struct nvmf_ctrl_options *opts); 156 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size); 157 bool nvmf_should_reconnect(struct nvme_ctrl *ctrl); 158 159 static inline blk_status_t nvmf_check_init_req(struct nvme_ctrl *ctrl, 160 struct request *rq) 161 { 162 struct nvme_command *cmd = nvme_req(rq)->cmd; 163 164 /* 165 * We cannot accept any other command until the connect command has 166 * completed, so only allow connect to pass. 167 */ 168 if (!blk_rq_is_passthrough(rq) || 169 cmd->common.opcode != nvme_fabrics_command || 170 cmd->fabrics.fctype != nvme_fabrics_type_connect) { 171 /* 172 * Reconnecting state means transport disruption, which can take 173 * a long time and even might fail permanently, fail fast to 174 * give upper layers a chance to failover. 175 * Deleting state means that the ctrl will never accept commands 176 * again, fail it permanently. 177 */ 178 if (ctrl->state == NVME_CTRL_RECONNECTING || 179 ctrl->state == NVME_CTRL_DELETING) { 180 nvme_req(rq)->status = NVME_SC_ABORT_REQ; 181 return BLK_STS_IOERR; 182 } 183 return BLK_STS_RESOURCE; /* try again later */ 184 } 185 186 return BLK_STS_OK; 187 } 188 189 #endif /* _NVME_FABRICS_H */ 190