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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 */
35struct 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 */
45enum {
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 NVMF_OPT_DISABLE_SQFLOW = 1 << 14,
62 NVMF_OPT_HDR_DIGEST = 1 << 15,
63 NVMF_OPT_DATA_DIGEST = 1 << 16,
64 NVMF_OPT_NR_WRITE_QUEUES = 1 << 17,
65 NVMF_OPT_NR_POLL_QUEUES = 1 << 18,
66};
67
68/**
69 * struct nvmf_ctrl_options - Used to hold the options specified
70 * with the parsing opts enum.
71 * @mask: Used by the fabrics library to parse through sysfs options
72 * on adding a NVMe controller.
73 * @transport: Holds the fabric transport "technology name" (for a lack of
74 * better description) that will be used by an NVMe controller
75 * being added.
76 * @subsysnqn: Hold the fully qualified NQN subystem name (format defined
77 * in the NVMe specification, "NVMe Qualified Names").
78 * @traddr: The transport-specific TRADDR field for a port on the
79 * subsystem which is adding a controller.
80 * @trsvcid: The transport-specific TRSVCID field for a port on the
81 * subsystem which is adding a controller.
82 * @host_traddr: A transport-specific field identifying the NVME host port
83 * to use for the connection to the controller.
84 * @queue_size: Number of IO queue elements.
85 * @nr_io_queues: Number of controller IO queues that will be established.
86 * @reconnect_delay: Time between two consecutive reconnect attempts.
87 * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
88 * @kato: Keep-alive timeout.
89 * @host: Virtual NVMe host, contains the NQN and Host ID.
90 * @max_reconnects: maximum number of allowed reconnect attempts before removing
91 * the controller, (-1) means reconnect forever, zero means remove
92 * immediately;
93 * @disable_sqflow: disable controller sq flow control
94 * @hdr_digest: generate/verify header digest (TCP)
95 * @data_digest: generate/verify data digest (TCP)
96 * @nr_write_queues: number of queues for write I/O
97 * @nr_poll_queues: number of queues for polling I/O
98 */
99struct nvmf_ctrl_options {
100 unsigned mask;
101 char *transport;
102 char *subsysnqn;
103 char *traddr;
104 char *trsvcid;
105 char *host_traddr;
106 size_t queue_size;
107 unsigned int nr_io_queues;
108 unsigned int reconnect_delay;
109 bool discovery_nqn;
110 bool duplicate_connect;
111 unsigned int kato;
112 struct nvmf_host *host;
113 int max_reconnects;
114 bool disable_sqflow;
115 bool hdr_digest;
116 bool data_digest;
117 unsigned int nr_write_queues;
118 unsigned int nr_poll_queues;
119};
120
121/*
122 * struct nvmf_transport_ops - used to register a specific
123 * fabric implementation of NVMe fabrics.
124 * @entry: Used by the fabrics library to add the new
125 * registration entry to its linked-list internal tree.
126 * @module: Transport module reference
127 * @name: Name of the NVMe fabric driver implementation.
128 * @required_opts: sysfs command-line options that must be specified
129 * when adding a new NVMe controller.
130 * @allowed_opts: sysfs command-line options that can be specified
131 * when adding a new NVMe controller.
132 * @create_ctrl(): function pointer that points to a non-NVMe
133 * implementation-specific fabric technology
134 * that would go into starting up that fabric
135 * for the purpose of conneciton to an NVMe controller
136 * using that fabric technology.
137 *
138 * Notes:
139 * 1. At minimum, 'required_opts' and 'allowed_opts' should
140 * be set to the same enum parsing options defined earlier.
141 * 2. create_ctrl() must be defined (even if it does nothing)
142 * 3. struct nvmf_transport_ops must be statically allocated in the
143 * modules .bss section so that a pure module_get on @module
144 * prevents the memory from beeing freed.
145 */
146struct nvmf_transport_ops {
147 struct list_head entry;
148 struct module *module;
149 const char *name;
150 int required_opts;
151 int allowed_opts;
152 struct nvme_ctrl *(*create_ctrl)(struct device *dev,
153 struct nvmf_ctrl_options *opts);
154};
155
156static inline bool
157nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
158 struct nvmf_ctrl_options *opts)
159{
160 if (ctrl->state == NVME_CTRL_DELETING ||
161 ctrl->state == NVME_CTRL_DEAD ||
162 strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
163 strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
164 memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t)))
165 return false;
166
167 return true;
168}
169
170int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
171int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
172int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
173int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
174int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid, bool poll);
175int nvmf_register_transport(struct nvmf_transport_ops *ops);
176void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
177void nvmf_free_options(struct nvmf_ctrl_options *opts);
178int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
179bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
180blk_status_t nvmf_fail_nonready_command(struct nvme_ctrl *ctrl,
181 struct request *rq);
182bool __nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
183 bool queue_live);
184bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
185 struct nvmf_ctrl_options *opts);
186
187static inline bool nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
188 bool queue_live)
189{
190 if (likely(ctrl->state == NVME_CTRL_LIVE ||
191 ctrl->state == NVME_CTRL_ADMIN_ONLY))
192 return true;
193 return __nvmf_check_ready(ctrl, rq, queue_live);
194}
195
196#endif /* _NVME_FABRICS_H */