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