1 #ifndef SCSI_TRANSPORT_SRP_H
2 #define SCSI_TRANSPORT_SRP_H
3 
4 #include <linux/transport_class.h>
5 #include <linux/types.h>
6 #include <linux/mutex.h>
7 
8 #define SRP_RPORT_ROLE_INITIATOR 0
9 #define SRP_RPORT_ROLE_TARGET 1
10 
11 struct srp_rport_identifiers {
12 	u8 port_id[16];
13 	u8 roles;
14 };
15 
16 /**
17  * enum srp_rport_state - SRP transport layer state
18  * @SRP_RPORT_RUNNING:   Transport layer operational.
19  * @SRP_RPORT_BLOCKED:   Transport layer not operational; fast I/O fail timer
20  *                       is running and I/O has been blocked.
21  * @SRP_RPORT_FAIL_FAST: Fast I/O fail timer has expired; fail I/O fast.
22  * @SRP_RPORT_LOST:      Device loss timer has expired; port is being removed.
23  */
24 enum srp_rport_state {
25 	SRP_RPORT_RUNNING,
26 	SRP_RPORT_BLOCKED,
27 	SRP_RPORT_FAIL_FAST,
28 	SRP_RPORT_LOST,
29 };
30 
31 /**
32  * struct srp_rport
33  * @lld_data: LLD private data.
34  * @mutex:    Protects against concurrent rport reconnect / fast_io_fail /
35  *   dev_loss_tmo activity.
36  */
37 struct srp_rport {
38 	/* for initiator and target drivers */
39 
40 	struct device dev;
41 
42 	u8 port_id[16];
43 	u8 roles;
44 
45 	/* for initiator drivers */
46 
47 	void			*lld_data;
48 
49 	struct mutex		mutex;
50 	enum srp_rport_state	state;
51 	bool			deleted;
52 	int			reconnect_delay;
53 	int			failed_reconnects;
54 	struct delayed_work	reconnect_work;
55 	int			fast_io_fail_tmo;
56 	int			dev_loss_tmo;
57 	struct delayed_work	fast_io_fail_work;
58 	struct delayed_work	dev_loss_work;
59 };
60 
61 /**
62  * struct srp_function_template
63  * @has_rport_state: Whether or not to create the state, fast_io_fail_tmo and
64  *     dev_loss_tmo sysfs attribute for an rport.
65  * @reset_timer_if_blocked: Whether or srp_timed_out() should reset the command
66  *     timer if the device on which it has been queued is blocked.
67  * @reconnect_delay: If not NULL, points to the default reconnect_delay value.
68  * @fast_io_fail_tmo: If not NULL, points to the default fast_io_fail_tmo value.
69  * @dev_loss_tmo: If not NULL, points to the default dev_loss_tmo value.
70  * @reconnect: Callback function for reconnecting to the target. See also
71  *     srp_reconnect_rport().
72  * @terminate_rport_io: Callback function for terminating all outstanding I/O
73  *     requests for an rport.
74  */
75 struct srp_function_template {
76 	/* for initiator drivers */
77 	bool has_rport_state;
78 	bool reset_timer_if_blocked;
79 	int *reconnect_delay;
80 	int *fast_io_fail_tmo;
81 	int *dev_loss_tmo;
82 	int (*reconnect)(struct srp_rport *rport);
83 	void (*terminate_rport_io)(struct srp_rport *rport);
84 	void (*rport_delete)(struct srp_rport *rport);
85 	/* for target drivers */
86 	int (* tsk_mgmt_response)(struct Scsi_Host *, u64, u64, int);
87 	int (* it_nexus_response)(struct Scsi_Host *, u64, int);
88 };
89 
90 extern struct scsi_transport_template *
91 srp_attach_transport(struct srp_function_template *);
92 extern void srp_release_transport(struct scsi_transport_template *);
93 
94 extern void srp_rport_get(struct srp_rport *rport);
95 extern void srp_rport_put(struct srp_rport *rport);
96 extern struct srp_rport *srp_rport_add(struct Scsi_Host *,
97 				       struct srp_rport_identifiers *);
98 extern void srp_rport_del(struct srp_rport *);
99 extern int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo,
100 			 int dev_loss_tmo);
101 extern int srp_reconnect_rport(struct srp_rport *rport);
102 extern void srp_start_tl_fail_timers(struct srp_rport *rport);
103 extern void srp_remove_host(struct Scsi_Host *);
104 
105 /**
106  * srp_chkready() - evaluate the transport layer state before I/O
107  *
108  * Returns a SCSI result code that can be returned by the LLD queuecommand()
109  * implementation. The role of this function is similar to that of
110  * fc_remote_port_chkready().
111  */
112 static inline int srp_chkready(struct srp_rport *rport)
113 {
114 	switch (rport->state) {
115 	case SRP_RPORT_RUNNING:
116 	case SRP_RPORT_BLOCKED:
117 	default:
118 		return 0;
119 	case SRP_RPORT_FAIL_FAST:
120 		return DID_TRANSPORT_FAILFAST << 16;
121 	case SRP_RPORT_LOST:
122 		return DID_NO_CONNECT << 16;
123 	}
124 }
125 
126 #endif
127