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
19 /*
20 * Define a host as seen by the target. We allocate one at boot, but also
21 * allow the override it when creating controllers. This is both to provide
22 * persistence of the Host NQN over multiple boots, and to allow using
23 * multiple ones, for example in a container scenario. Because we must not
24 * use different Host NQNs with the same Host ID we generate a Host ID and
25 * use this structure to keep track of the relation between the two.
26 */
27 struct nvmf_host {
28 struct kref ref;
29 struct list_head list;
30 char nqn[NVMF_NQN_SIZE];
31 uuid_t id;
32 };
33
34 /**
35 * enum nvmf_parsing_opts - used to define the sysfs parsing options used.
36 */
37 enum {
38 NVMF_OPT_ERR = 0,
39 NVMF_OPT_TRANSPORT = 1 << 0,
40 NVMF_OPT_NQN = 1 << 1,
41 NVMF_OPT_TRADDR = 1 << 2,
42 NVMF_OPT_TRSVCID = 1 << 3,
43 NVMF_OPT_QUEUE_SIZE = 1 << 4,
44 NVMF_OPT_NR_IO_QUEUES = 1 << 5,
45 NVMF_OPT_TL_RETRY_COUNT = 1 << 6,
46 NVMF_OPT_KATO = 1 << 7,
47 NVMF_OPT_HOSTNQN = 1 << 8,
48 NVMF_OPT_RECONNECT_DELAY = 1 << 9,
49 NVMF_OPT_HOST_TRADDR = 1 << 10,
50 NVMF_OPT_CTRL_LOSS_TMO = 1 << 11,
51 NVMF_OPT_HOST_ID = 1 << 12,
52 NVMF_OPT_DUP_CONNECT = 1 << 13,
53 NVMF_OPT_DISABLE_SQFLOW = 1 << 14,
54 NVMF_OPT_HDR_DIGEST = 1 << 15,
55 NVMF_OPT_DATA_DIGEST = 1 << 16,
56 NVMF_OPT_NR_WRITE_QUEUES = 1 << 17,
57 NVMF_OPT_NR_POLL_QUEUES = 1 << 18,
58 NVMF_OPT_TOS = 1 << 19,
59 };
60
61 /**
62 * struct nvmf_ctrl_options - Used to hold the options specified
63 * with the parsing opts enum.
64 * @mask: Used by the fabrics library to parse through sysfs options
65 * on adding a NVMe controller.
66 * @transport: Holds the fabric transport "technology name" (for a lack of
67 * better description) that will be used by an NVMe controller
68 * being added.
69 * @subsysnqn: Hold the fully qualified NQN subystem name (format defined
70 * in the NVMe specification, "NVMe Qualified Names").
71 * @traddr: The transport-specific TRADDR field for a port on the
72 * subsystem which is adding a controller.
73 * @trsvcid: The transport-specific TRSVCID field for a port on the
74 * subsystem which is adding a controller.
75 * @host_traddr: A transport-specific field identifying the NVME host port
76 * to use for the connection to the controller.
77 * @queue_size: Number of IO queue elements.
78 * @nr_io_queues: Number of controller IO queues that will be established.
79 * @reconnect_delay: Time between two consecutive reconnect attempts.
80 * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
81 * @kato: Keep-alive timeout.
82 * @host: Virtual NVMe host, contains the NQN and Host ID.
83 * @max_reconnects: maximum number of allowed reconnect attempts before removing
84 * the controller, (-1) means reconnect forever, zero means remove
85 * immediately;
86 * @disable_sqflow: disable controller sq flow control
87 * @hdr_digest: generate/verify header digest (TCP)
88 * @data_digest: generate/verify data digest (TCP)
89 * @nr_write_queues: number of queues for write I/O
90 * @nr_poll_queues: number of queues for polling I/O
91 * @tos: type of service
92 */
93 struct nvmf_ctrl_options {
94 unsigned mask;
95 char *transport;
96 char *subsysnqn;
97 char *traddr;
98 char *trsvcid;
99 char *host_traddr;
100 size_t queue_size;
101 unsigned int nr_io_queues;
102 unsigned int reconnect_delay;
103 bool discovery_nqn;
104 bool duplicate_connect;
105 unsigned int kato;
106 struct nvmf_host *host;
107 int max_reconnects;
108 bool disable_sqflow;
109 bool hdr_digest;
110 bool data_digest;
111 unsigned int nr_write_queues;
112 unsigned int nr_poll_queues;
113 int tos;
114 };
115
116 /*
117 * struct nvmf_transport_ops - used to register a specific
118 * fabric implementation of NVMe fabrics.
119 * @entry: Used by the fabrics library to add the new
120 * registration entry to its linked-list internal tree.
121 * @module: Transport module reference
122 * @name: Name of the NVMe fabric driver implementation.
123 * @required_opts: sysfs command-line options that must be specified
124 * when adding a new NVMe controller.
125 * @allowed_opts: sysfs command-line options that can be specified
126 * when adding a new NVMe controller.
127 * @create_ctrl(): function pointer that points to a non-NVMe
128 * implementation-specific fabric technology
129 * that would go into starting up that fabric
130 * for the purpose of conneciton to an NVMe controller
131 * using that fabric technology.
132 *
133 * Notes:
134 * 1. At minimum, 'required_opts' and 'allowed_opts' should
135 * be set to the same enum parsing options defined earlier.
136 * 2. create_ctrl() must be defined (even if it does nothing)
137 * 3. struct nvmf_transport_ops must be statically allocated in the
138 * modules .bss section so that a pure module_get on @module
139 * prevents the memory from beeing freed.
140 */
141 struct nvmf_transport_ops {
142 struct list_head entry;
143 struct module *module;
144 const char *name;
145 int required_opts;
146 int allowed_opts;
147 struct nvme_ctrl *(*create_ctrl)(struct device *dev,
148 struct nvmf_ctrl_options *opts);
149 };
150
151 static inline bool
152 nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
153 struct nvmf_ctrl_options *opts)
154 {
155 if (ctrl->state == NVME_CTRL_DELETING ||
156 ctrl->state == NVME_CTRL_DEAD ||
157 strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
158 strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
159 memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t)))
160 return false;
161
162 return true;
163 }
164
165 int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
166 int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
167 int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
168 int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
169 int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid, bool poll);
170 int nvmf_register_transport(struct nvmf_transport_ops *ops);
171 void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
172 void nvmf_free_options(struct nvmf_ctrl_options *opts);
173 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
174 bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
175 blk_status_t nvmf_fail_nonready_command(struct nvme_ctrl *ctrl,
176 struct request *rq);
177 bool __nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
178 bool queue_live);
179 bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
180 struct nvmf_ctrl_options *opts);
181
182 static inline bool nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
183 bool queue_live)
184 {
185 if (likely(ctrl->state == NVME_CTRL_LIVE))
186 return true;
187 return __nvmf_check_ready(ctrl, rq, queue_live);
188 }
189
190 #endif /* _NVME_FABRICS_H */