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};
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 * @max_reconnects: maximum number of allowed reconnect attempts before removing
74 *		the controller, (-1) means reconnect forever, zero means remove
75 *		immediately;
76 * @transport:	Holds the fabric transport "technology name" (for a lack of
77 *		better description) that will be used by an NVMe controller
78 *		being added.
79 * @subsysnqn:	Hold the fully qualified NQN subystem name (format defined
80 *		in the NVMe specification, "NVMe Qualified Names").
81 * @traddr:	The transport-specific TRADDR field for a port on the
82 *              subsystem which is adding a controller.
83 * @trsvcid:	The transport-specific TRSVCID field for a port on the
84 *              subsystem which is adding a controller.
85 * @host_traddr: A transport-specific field identifying the NVME host port
86 *     to use for the connection to the controller.
87 * @host_iface: A transport-specific field identifying the NVME host
88 *     interface to use for the connection to the controller.
89 * @queue_size: Number of IO queue elements.
90 * @nr_io_queues: Number of controller IO queues that will be established.
91 * @reconnect_delay: Time between two consecutive reconnect attempts.
92 * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
93 * @kato:	Keep-alive timeout.
94 * @host:	Virtual NVMe host, contains the NQN and Host ID.
95 * @dhchap_secret: DH-HMAC-CHAP secret
96 * @dhchap_ctrl_secret: DH-HMAC-CHAP controller secret for bi-directional
97 *              authentication
98 * @disable_sqflow: disable controller sq flow control
99 * @hdr_digest: generate/verify header digest (TCP)
100 * @data_digest: generate/verify data digest (TCP)
101 * @nr_write_queues: number of queues for write I/O
102 * @nr_poll_queues: number of queues for polling I/O
103 * @tos: type of service
104 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds
105 */
106struct nvmf_ctrl_options {
107	unsigned		mask;
108	int			max_reconnects;
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	char			*dhchap_secret;
123	char			*dhchap_ctrl_secret;
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 */
158struct 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
168static inline bool
169nvmf_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	    !uuid_equal(&opts->host->id, &ctrl->opts->host->id))
178		return false;
179
180	return true;
181}
182
183static inline char *nvmf_ctrl_subsysnqn(struct nvme_ctrl *ctrl)
184{
185	if (!ctrl->subsys ||
186	    !strcmp(ctrl->opts->subsysnqn, NVME_DISC_SUBSYS_NAME))
187		return ctrl->opts->subsysnqn;
188	return ctrl->subsys->subnqn;
189}
190
191static inline void nvmf_complete_timed_out_request(struct request *rq)
192{
193	if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) {
194		nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD;
195		blk_mq_complete_request(rq);
196	}
197}
198
199static inline unsigned int nvmf_nr_io_queues(struct nvmf_ctrl_options *opts)
200{
201	return min(opts->nr_io_queues, num_online_cpus()) +
202		min(opts->nr_write_queues, num_online_cpus()) +
203		min(opts->nr_poll_queues, num_online_cpus());
204}
205
206int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
207int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
208int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
209int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
210int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
211int nvmf_register_transport(struct nvmf_transport_ops *ops);
212void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
213void nvmf_free_options(struct nvmf_ctrl_options *opts);
214int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
215bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
216bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
217		struct nvmf_ctrl_options *opts);
218void nvmf_set_io_queues(struct nvmf_ctrl_options *opts, u32 nr_io_queues,
219			u32 io_queues[HCTX_MAX_TYPES]);
220void nvmf_map_queues(struct blk_mq_tag_set *set, struct nvme_ctrl *ctrl,
221		     u32 io_queues[HCTX_MAX_TYPES]);
222
223#endif /* _NVME_FABRICS_H */
224