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  	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   */
112  struct 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   */
167  struct 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  
177  static inline bool
nvmf_ctlr_matches_baseopts(struct nvme_ctrl * ctrl,struct nvmf_ctrl_options * opts)178  nvmf_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  
nvmf_ctrl_subsysnqn(struct nvme_ctrl * ctrl)194  static 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  
nvmf_complete_timed_out_request(struct request * rq)202  static 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  
nvmf_nr_io_queues(struct nvmf_ctrl_options * opts)210  static 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  
217  int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
218  int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
219  int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
220  int nvmf_subsystem_reset(struct nvme_ctrl *ctrl);
221  int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
222  int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
223  int nvmf_register_transport(struct nvmf_transport_ops *ops);
224  void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
225  void nvmf_free_options(struct nvmf_ctrl_options *opts);
226  int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
227  bool nvmf_should_reconnect(struct nvme_ctrl *ctrl, int status);
228  bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
229  		struct nvmf_ctrl_options *opts);
230  void nvmf_set_io_queues(struct nvmf_ctrl_options *opts, u32 nr_io_queues,
231  			u32 io_queues[HCTX_MAX_TYPES]);
232  void nvmf_map_queues(struct blk_mq_tag_set *set, struct nvme_ctrl *ctrl,
233  		     u32 io_queues[HCTX_MAX_TYPES]);
234  
235  #endif /* _NVME_FABRICS_H */
236