xref: /openbmc/linux/drivers/nvme/host/fabrics.h (revision 6197e5b7)
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 };
63 
64 /**
65  * struct nvmf_ctrl_options - Used to hold the options specified
66  *			      with the parsing opts enum.
67  * @mask:	Used by the fabrics library to parse through sysfs options
68  *		on adding a NVMe controller.
69  * @transport:	Holds the fabric transport "technology name" (for a lack of
70  *		better description) that will be used by an NVMe controller
71  *		being added.
72  * @subsysnqn:	Hold the fully qualified NQN subystem name (format defined
73  *		in the NVMe specification, "NVMe Qualified Names").
74  * @traddr:	The transport-specific TRADDR field for a port on the
75  *              subsystem which is adding a controller.
76  * @trsvcid:	The transport-specific TRSVCID field for a port on the
77  *              subsystem which is adding a controller.
78  * @host_traddr: A transport-specific field identifying the NVME host port
79  *              to use for the connection to the controller.
80  * @queue_size: Number of IO queue elements.
81  * @nr_io_queues: Number of controller IO queues that will be established.
82  * @reconnect_delay: Time between two consecutive reconnect attempts.
83  * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
84  * @kato:	Keep-alive timeout.
85  * @host:	Virtual NVMe host, contains the NQN and Host ID.
86  * @max_reconnects: maximum number of allowed reconnect attempts before removing
87  *              the controller, (-1) means reconnect forever, zero means remove
88  *              immediately;
89  * @disable_sqflow: disable controller sq flow control
90  * @hdr_digest: generate/verify header digest (TCP)
91  * @data_digest: generate/verify data digest (TCP)
92  * @nr_write_queues: number of queues for write I/O
93  * @nr_poll_queues: number of queues for polling I/O
94  * @tos: type of service
95  * @fast_io_fail_tmo: Fast I/O fail timeout in seconds
96  */
97 struct nvmf_ctrl_options {
98 	unsigned		mask;
99 	char			*transport;
100 	char			*subsysnqn;
101 	char			*traddr;
102 	char			*trsvcid;
103 	char			*host_traddr;
104 	size_t			queue_size;
105 	unsigned int		nr_io_queues;
106 	unsigned int		reconnect_delay;
107 	bool			discovery_nqn;
108 	bool			duplicate_connect;
109 	unsigned int		kato;
110 	struct nvmf_host	*host;
111 	int			max_reconnects;
112 	bool			disable_sqflow;
113 	bool			hdr_digest;
114 	bool			data_digest;
115 	unsigned int		nr_write_queues;
116 	unsigned int		nr_poll_queues;
117 	int			tos;
118 	int			fast_io_fail_tmo;
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  */
146 struct 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 
156 static inline bool
157 nvmf_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 
170 int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
171 int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
172 int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
173 int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
174 int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid, bool poll);
175 int nvmf_register_transport(struct nvmf_transport_ops *ops);
176 void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
177 void nvmf_free_options(struct nvmf_ctrl_options *opts);
178 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
179 bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
180 blk_status_t nvmf_fail_nonready_command(struct nvme_ctrl *ctrl,
181 		struct request *rq);
182 bool __nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
183 		bool queue_live);
184 bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
185 		struct nvmf_ctrl_options *opts);
186 
187 static 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_DELETING))
192 		return true;
193 	return __nvmf_check_ready(ctrl, rq, queue_live);
194 }
195 
196 #endif /* _NVME_FABRICS_H */
197