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