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 * Define a host as seen by the target.  We allocate one at boot, but also
23 * allow the override it when creating controllers.  This is both to provide
24 * persistence of the Host NQN over multiple boots, and to allow using
25 * multiple ones, for example in a container scenario.  Because we must not
26 * use different Host NQNs with the same Host ID we generate a Host ID and
27 * use this structure to keep track of the relation between the two.
28 */
29struct nvmf_host {
30	struct kref		ref;
31	struct list_head	list;
32	char			nqn[NVMF_NQN_SIZE];
33	uuid_t			id;
34};
35
36/**
37 * enum nvmf_parsing_opts - used to define the sysfs parsing options used.
38 */
39enum {
40	NVMF_OPT_ERR		= 0,
41	NVMF_OPT_TRANSPORT	= 1 << 0,
42	NVMF_OPT_NQN		= 1 << 1,
43	NVMF_OPT_TRADDR		= 1 << 2,
44	NVMF_OPT_TRSVCID	= 1 << 3,
45	NVMF_OPT_QUEUE_SIZE	= 1 << 4,
46	NVMF_OPT_NR_IO_QUEUES	= 1 << 5,
47	NVMF_OPT_TL_RETRY_COUNT	= 1 << 6,
48	NVMF_OPT_KATO		= 1 << 7,
49	NVMF_OPT_HOSTNQN	= 1 << 8,
50	NVMF_OPT_RECONNECT_DELAY = 1 << 9,
51	NVMF_OPT_HOST_TRADDR	= 1 << 10,
52	NVMF_OPT_CTRL_LOSS_TMO	= 1 << 11,
53	NVMF_OPT_HOST_ID	= 1 << 12,
54	NVMF_OPT_DUP_CONNECT	= 1 << 13,
55	NVMF_OPT_DISABLE_SQFLOW = 1 << 14,
56	NVMF_OPT_HDR_DIGEST	= 1 << 15,
57	NVMF_OPT_DATA_DIGEST	= 1 << 16,
58	NVMF_OPT_NR_WRITE_QUEUES = 1 << 17,
59	NVMF_OPT_NR_POLL_QUEUES = 1 << 18,
60	NVMF_OPT_TOS		= 1 << 19,
61	NVMF_OPT_FAIL_FAST_TMO	= 1 << 20,
62	NVMF_OPT_HOST_IFACE	= 1 << 21,
63	NVMF_OPT_DISCOVERY	= 1 << 22,
64	NVMF_OPT_DHCHAP_SECRET	= 1 << 23,
65	NVMF_OPT_DHCHAP_CTRL_SECRET = 1 << 24,
66	NVMF_OPT_TLS		= 1 << 25,
67	NVMF_OPT_KEYRING	= 1 << 26,
68	NVMF_OPT_TLS_KEY	= 1 << 27,
69};
70
71/**
72 * struct nvmf_ctrl_options - Used to hold the options specified
73 *			      with the parsing opts enum.
74 * @mask:	Used by the fabrics library to parse through sysfs options
75 *		on adding a NVMe controller.
76 * @max_reconnects: maximum number of allowed reconnect attempts before removing
77 *		the controller, (-1) means reconnect forever, zero means remove
78 *		immediately;
79 * @transport:	Holds the fabric transport "technology name" (for a lack of
80 *		better description) that will be used by an NVMe controller
81 *		being added.
82 * @subsysnqn:	Hold the fully qualified NQN subystem name (format defined
83 *		in the NVMe specification, "NVMe Qualified Names").
84 * @traddr:	The transport-specific TRADDR field for a port on the
85 *              subsystem which is adding a controller.
86 * @trsvcid:	The transport-specific TRSVCID field for a port on the
87 *              subsystem which is adding a controller.
88 * @host_traddr: A transport-specific field identifying the NVME host port
89 *     to use for the connection to the controller.
90 * @host_iface: A transport-specific field identifying the NVME host
91 *     interface to use for the connection to the controller.
92 * @queue_size: Number of IO queue elements.
93 * @nr_io_queues: Number of controller IO queues that will be established.
94 * @reconnect_delay: Time between two consecutive reconnect attempts.
95 * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
96 * @kato:	Keep-alive timeout.
97 * @host:	Virtual NVMe host, contains the NQN and Host ID.
98 * @dhchap_secret: DH-HMAC-CHAP secret
99 * @dhchap_ctrl_secret: DH-HMAC-CHAP controller secret for bi-directional
100 *              authentication
101 * @keyring:    Keyring to use for key lookups
102 * @tls_key:    TLS key for encrypted connections (TCP)
103 * @tls:        Start TLS encrypted connections (TCP)
104 * @disable_sqflow: disable controller sq flow control
105 * @hdr_digest: generate/verify header digest (TCP)
106 * @data_digest: generate/verify data digest (TCP)
107 * @nr_write_queues: number of queues for write I/O
108 * @nr_poll_queues: number of queues for polling I/O
109 * @tos: type of service
110 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds
111 */
112struct nvmf_ctrl_options {
113	unsigned		mask;
114	int			max_reconnects;
115	char			*transport;
116	char			*subsysnqn;
117	char			*traddr;
118	char			*trsvcid;
119	char			*host_traddr;
120	char			*host_iface;
121	size_t			queue_size;
122	unsigned int		nr_io_queues;
123	unsigned int		reconnect_delay;
124	bool			discovery_nqn;
125	bool			duplicate_connect;
126	unsigned int		kato;
127	struct nvmf_host	*host;
128	char			*dhchap_secret;
129	char			*dhchap_ctrl_secret;
130	struct key		*keyring;
131	struct key		*tls_key;
132	bool			tls;
133	bool			disable_sqflow;
134	bool			hdr_digest;
135	bool			data_digest;
136	unsigned int		nr_write_queues;
137	unsigned int		nr_poll_queues;
138	int			tos;
139	int			fast_io_fail_tmo;
140};
141
142/*
143 * struct nvmf_transport_ops - used to register a specific
144 *			       fabric implementation of NVMe fabrics.
145 * @entry:		Used by the fabrics library to add the new
146 *			registration entry to its linked-list internal tree.
147 * @module:             Transport module reference
148 * @name:		Name of the NVMe fabric driver implementation.
149 * @required_opts:	sysfs command-line options that must be specified
150 *			when adding a new NVMe controller.
151 * @allowed_opts:	sysfs command-line options that can be specified
152 *			when adding a new NVMe controller.
153 * @create_ctrl():	function pointer that points to a non-NVMe
154 *			implementation-specific fabric technology
155 *			that would go into starting up that fabric
156 *			for the purpose of conneciton to an NVMe controller
157 *			using that fabric technology.
158 *
159 * Notes:
160 *	1. At minimum, 'required_opts' and 'allowed_opts' should
161 *	   be set to the same enum parsing options defined earlier.
162 *	2. create_ctrl() must be defined (even if it does nothing)
163 *	3. struct nvmf_transport_ops must be statically allocated in the
164 *	   modules .bss section so that a pure module_get on @module
165 *	   prevents the memory from beeing freed.
166 */
167struct nvmf_transport_ops {
168	struct list_head	entry;
169	struct module		*module;
170	const char		*name;
171	int			required_opts;
172	int			allowed_opts;
173	struct nvme_ctrl	*(*create_ctrl)(struct device *dev,
174					struct nvmf_ctrl_options *opts);
175};
176
177static inline bool
178nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
179			struct nvmf_ctrl_options *opts)
180{
181	enum nvme_ctrl_state state = nvme_ctrl_state(ctrl);
182
183	if (state == NVME_CTRL_DELETING ||
184	    state == NVME_CTRL_DELETING_NOIO ||
185	    state == NVME_CTRL_DEAD ||
186	    strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
187	    strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
188	    !uuid_equal(&opts->host->id, &ctrl->opts->host->id))
189		return false;
190
191	return true;
192}
193
194static inline char *nvmf_ctrl_subsysnqn(struct nvme_ctrl *ctrl)
195{
196	if (!ctrl->subsys ||
197	    !strcmp(ctrl->opts->subsysnqn, NVME_DISC_SUBSYS_NAME))
198		return ctrl->opts->subsysnqn;
199	return ctrl->subsys->subnqn;
200}
201
202static inline void nvmf_complete_timed_out_request(struct request *rq)
203{
204	if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) {
205		nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD;
206		blk_mq_complete_request(rq);
207	}
208}
209
210static inline unsigned int nvmf_nr_io_queues(struct nvmf_ctrl_options *opts)
211{
212	return min(opts->nr_io_queues, num_online_cpus()) +
213		min(opts->nr_write_queues, num_online_cpus()) +
214		min(opts->nr_poll_queues, num_online_cpus());
215}
216
217int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
218int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
219int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
220int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
221int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
222int nvmf_register_transport(struct nvmf_transport_ops *ops);
223void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
224void nvmf_free_options(struct nvmf_ctrl_options *opts);
225int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
226bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
227bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
228		struct nvmf_ctrl_options *opts);
229void nvmf_set_io_queues(struct nvmf_ctrl_options *opts, u32 nr_io_queues,
230			u32 io_queues[HCTX_MAX_TYPES]);
231void nvmf_map_queues(struct blk_mq_tag_set *set, struct nvme_ctrl *ctrl,
232		     u32 io_queues[HCTX_MAX_TYPES]);
233
234#endif /* _NVME_FABRICS_H */
235