xref: /openbmc/linux/drivers/nvme/host/fabrics.h (revision f0931824)
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  */
29 struct 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  */
39 enum {
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  */
106 struct 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  */
158 struct 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 
168 static inline bool
169 nvmf_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 
183 static 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 
191 static 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 
199 static 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 
206 int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
207 int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
208 int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
209 int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
210 int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
211 int nvmf_register_transport(struct nvmf_transport_ops *ops);
212 void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
213 void nvmf_free_options(struct nvmf_ctrl_options *opts);
214 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
215 bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
216 bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
217 		struct nvmf_ctrl_options *opts);
218 void nvmf_set_io_queues(struct nvmf_ctrl_options *opts, u32 nr_io_queues,
219 			u32 io_queues[HCTX_MAX_TYPES]);
220 void 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