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  * Reserved one command for internal usage.  This command is used for sending
23  * the connect command, as well as for the keep alive command on the admin
24  * queue once live.
25  */
26 #define NVMF_RESERVED_TAGS	1
27 
28 /*
29  * Define a host as seen by the target.  We allocate one at boot, but also
30  * allow the override it when creating controllers.  This is both to provide
31  * persistence of the Host NQN over multiple boots, and to allow using
32  * multiple ones, for example in a container scenario.  Because we must not
33  * use different Host NQNs with the same Host ID we generate a Host ID and
34  * use this structure to keep track of the relation between the two.
35  */
36 struct nvmf_host {
37 	struct kref		ref;
38 	struct list_head	list;
39 	char			nqn[NVMF_NQN_SIZE];
40 	uuid_t			id;
41 };
42 
43 /**
44  * enum nvmf_parsing_opts - used to define the sysfs parsing options used.
45  */
46 enum {
47 	NVMF_OPT_ERR		= 0,
48 	NVMF_OPT_TRANSPORT	= 1 << 0,
49 	NVMF_OPT_NQN		= 1 << 1,
50 	NVMF_OPT_TRADDR		= 1 << 2,
51 	NVMF_OPT_TRSVCID	= 1 << 3,
52 	NVMF_OPT_QUEUE_SIZE	= 1 << 4,
53 	NVMF_OPT_NR_IO_QUEUES	= 1 << 5,
54 	NVMF_OPT_TL_RETRY_COUNT	= 1 << 6,
55 	NVMF_OPT_KATO		= 1 << 7,
56 	NVMF_OPT_HOSTNQN	= 1 << 8,
57 	NVMF_OPT_RECONNECT_DELAY = 1 << 9,
58 	NVMF_OPT_HOST_TRADDR	= 1 << 10,
59 	NVMF_OPT_CTRL_LOSS_TMO	= 1 << 11,
60 	NVMF_OPT_HOST_ID	= 1 << 12,
61 	NVMF_OPT_DUP_CONNECT	= 1 << 13,
62 	NVMF_OPT_DISABLE_SQFLOW = 1 << 14,
63 	NVMF_OPT_HDR_DIGEST	= 1 << 15,
64 	NVMF_OPT_DATA_DIGEST	= 1 << 16,
65 	NVMF_OPT_NR_WRITE_QUEUES = 1 << 17,
66 	NVMF_OPT_NR_POLL_QUEUES = 1 << 18,
67 	NVMF_OPT_TOS		= 1 << 19,
68 	NVMF_OPT_FAIL_FAST_TMO	= 1 << 20,
69 	NVMF_OPT_HOST_IFACE	= 1 << 21,
70 	NVMF_OPT_DISCOVERY	= 1 << 22,
71 };
72 
73 /**
74  * struct nvmf_ctrl_options - Used to hold the options specified
75  *			      with the parsing opts enum.
76  * @mask:	Used by the fabrics library to parse through sysfs options
77  *		on adding a NVMe controller.
78  * @transport:	Holds the fabric transport "technology name" (for a lack of
79  *		better description) that will be used by an NVMe controller
80  *		being added.
81  * @subsysnqn:	Hold the fully qualified NQN subystem name (format defined
82  *		in the NVMe specification, "NVMe Qualified Names").
83  * @traddr:	The transport-specific TRADDR field for a port on the
84  *              subsystem which is adding a controller.
85  * @trsvcid:	The transport-specific TRSVCID field for a port on the
86  *              subsystem which is adding a controller.
87  * @host_traddr: A transport-specific field identifying the NVME host port
88  *     to use for the connection to the controller.
89  * @host_iface: A transport-specific field identifying the NVME host
90  *     interface to use for the connection to the controller.
91  * @queue_size: Number of IO queue elements.
92  * @nr_io_queues: Number of controller IO queues that will be established.
93  * @reconnect_delay: Time between two consecutive reconnect attempts.
94  * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
95  * @kato:	Keep-alive timeout.
96  * @host:	Virtual NVMe host, contains the NQN and Host ID.
97  * @max_reconnects: maximum number of allowed reconnect attempts before removing
98  *              the controller, (-1) means reconnect forever, zero means remove
99  *              immediately;
100  * @disable_sqflow: disable controller sq flow control
101  * @hdr_digest: generate/verify header digest (TCP)
102  * @data_digest: generate/verify data digest (TCP)
103  * @nr_write_queues: number of queues for write I/O
104  * @nr_poll_queues: number of queues for polling I/O
105  * @tos: type of service
106  * @fast_io_fail_tmo: Fast I/O fail timeout in seconds
107  */
108 struct nvmf_ctrl_options {
109 	unsigned		mask;
110 	char			*transport;
111 	char			*subsysnqn;
112 	char			*traddr;
113 	char			*trsvcid;
114 	char			*host_traddr;
115 	char			*host_iface;
116 	size_t			queue_size;
117 	unsigned int		nr_io_queues;
118 	unsigned int		reconnect_delay;
119 	bool			discovery_nqn;
120 	bool			duplicate_connect;
121 	unsigned int		kato;
122 	struct nvmf_host	*host;
123 	int			max_reconnects;
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
nvmf_ctlr_matches_baseopts(struct nvme_ctrl * ctrl,struct nvmf_ctrl_options * opts)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 	    memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t)))
178 		return false;
179 
180 	return true;
181 }
182 
nvmf_ctrl_subsysnqn(struct nvme_ctrl * ctrl)183 static inline char *nvmf_ctrl_subsysnqn(struct nvme_ctrl *ctrl)
184 {
185 	if (!ctrl->subsys)
186 		return ctrl->opts->subsysnqn;
187 	return ctrl->subsys->subnqn;
188 }
189 
nvmf_complete_timed_out_request(struct request * rq)190 static inline void nvmf_complete_timed_out_request(struct request *rq)
191 {
192 	if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) {
193 		nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD;
194 		blk_mq_complete_request(rq);
195 	}
196 }
197 
198 int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
199 int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
200 int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
201 int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
202 int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
203 int nvmf_register_transport(struct nvmf_transport_ops *ops);
204 void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
205 void nvmf_free_options(struct nvmf_ctrl_options *opts);
206 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
207 bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
208 bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
209 		struct nvmf_ctrl_options *opts);
210 
211 #endif /* _NVME_FABRICS_H */
212