1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef SCSI_TRANSPORT_SRP_H |
3 | #define SCSI_TRANSPORT_SRP_H |
4 | |
5 | #include <linux/transport_class.h> |
6 | #include <linux/types.h> |
7 | #include <linux/mutex.h> |
8 | |
9 | #define SRP_RPORT_ROLE_INITIATOR 0 |
10 | #define SRP_RPORT_ROLE_TARGET 1 |
11 | |
12 | struct srp_rport_identifiers { |
13 | u8 port_id[16]; |
14 | u8 roles; |
15 | }; |
16 | |
17 | /** |
18 | * enum srp_rport_state - SRP transport layer state |
19 | * @SRP_RPORT_RUNNING: Transport layer operational. |
20 | * @SRP_RPORT_BLOCKED: Transport layer not operational; fast I/O fail timer |
21 | * is running and I/O has been blocked. |
22 | * @SRP_RPORT_FAIL_FAST: Fast I/O fail timer has expired; fail I/O fast. |
23 | * @SRP_RPORT_LOST: Port is being removed. |
24 | */ |
25 | enum srp_rport_state { |
26 | SRP_RPORT_RUNNING, |
27 | SRP_RPORT_BLOCKED, |
28 | SRP_RPORT_FAIL_FAST, |
29 | SRP_RPORT_LOST, |
30 | }; |
31 | |
32 | /** |
33 | * struct srp_rport - SRP initiator or target port |
34 | * |
35 | * Fields that are relevant for SRP initiator and SRP target drivers: |
36 | * @dev: Device associated with this rport. |
37 | * @port_id: 16-byte port identifier. |
38 | * @roles: Role of this port - initiator or target. |
39 | * |
40 | * Fields that are only relevant for SRP initiator drivers: |
41 | * @lld_data: LLD private data. |
42 | * @mutex: Protects against concurrent rport reconnect / |
43 | * fast_io_fail / dev_loss_tmo activity. |
44 | * @state: rport state. |
45 | * @reconnect_delay: Reconnect delay in seconds. |
46 | * @failed_reconnects: Number of failed reconnect attempts. |
47 | * @reconnect_work: Work structure used for scheduling reconnect attempts. |
48 | * @fast_io_fail_tmo: Fast I/O fail timeout in seconds. |
49 | * @dev_loss_tmo: Device loss timeout in seconds. |
50 | * @fast_io_fail_work: Work structure used for scheduling fast I/O fail work. |
51 | * @dev_loss_work: Work structure used for scheduling device loss work. |
52 | */ |
53 | struct srp_rport { |
54 | /* for initiator and target drivers */ |
55 | |
56 | struct device dev; |
57 | |
58 | u8 port_id[16]; |
59 | u8 roles; |
60 | |
61 | /* for initiator drivers */ |
62 | |
63 | void *lld_data; |
64 | |
65 | struct mutex mutex; |
66 | enum srp_rport_state state; |
67 | int reconnect_delay; |
68 | int failed_reconnects; |
69 | struct delayed_work reconnect_work; |
70 | int fast_io_fail_tmo; |
71 | int dev_loss_tmo; |
72 | struct delayed_work fast_io_fail_work; |
73 | struct delayed_work dev_loss_work; |
74 | }; |
75 | |
76 | /** |
77 | * struct srp_function_template |
78 | * |
79 | * Fields that are only relevant for SRP initiator drivers: |
80 | * @has_rport_state: Whether or not to create the state, fast_io_fail_tmo and |
81 | * dev_loss_tmo sysfs attribute for an rport. |
82 | * @reset_timer_if_blocked: Whether or srp_timed_out() should reset the command |
83 | * timer if the device on which it has been queued is blocked. |
84 | * @reconnect_delay: If not NULL, points to the default reconnect_delay value. |
85 | * @fast_io_fail_tmo: If not NULL, points to the default fast_io_fail_tmo value. |
86 | * @dev_loss_tmo: If not NULL, points to the default dev_loss_tmo value. |
87 | * @reconnect: Callback function for reconnecting to the target. See also |
88 | * srp_reconnect_rport(). |
89 | * @terminate_rport_io: Callback function for terminating all outstanding I/O |
90 | * requests for an rport. |
91 | * @rport_delete: Callback function that deletes an rport. |
92 | */ |
93 | struct srp_function_template { |
94 | /* for initiator drivers */ |
95 | bool has_rport_state; |
96 | bool reset_timer_if_blocked; |
97 | int *reconnect_delay; |
98 | int *fast_io_fail_tmo; |
99 | int *dev_loss_tmo; |
100 | int (*reconnect)(struct srp_rport *rport); |
101 | void (*terminate_rport_io)(struct srp_rport *rport); |
102 | void (*rport_delete)(struct srp_rport *rport); |
103 | }; |
104 | |
105 | extern struct scsi_transport_template * |
106 | srp_attach_transport(struct srp_function_template *); |
107 | extern void srp_release_transport(struct scsi_transport_template *); |
108 | |
109 | extern void srp_rport_get(struct srp_rport *rport); |
110 | extern void srp_rport_put(struct srp_rport *rport); |
111 | extern struct srp_rport *srp_rport_add(struct Scsi_Host *, |
112 | struct srp_rport_identifiers *); |
113 | extern void srp_rport_del(struct srp_rport *); |
114 | extern int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, |
115 | long dev_loss_tmo); |
116 | int srp_parse_tmo(int *tmo, const char *buf); |
117 | extern int srp_reconnect_rport(struct srp_rport *rport); |
118 | extern void srp_start_tl_fail_timers(struct srp_rport *rport); |
119 | extern void srp_remove_host(struct Scsi_Host *); |
120 | extern void srp_stop_rport_timers(struct srp_rport *rport); |
121 | enum scsi_timeout_action srp_timed_out(struct scsi_cmnd *scmd); |
122 | |
123 | /** |
124 | * srp_chkready() - evaluate the transport layer state before I/O |
125 | * @rport: SRP target port pointer. |
126 | * |
127 | * Returns a SCSI result code that can be returned by the LLD queuecommand() |
128 | * implementation. The role of this function is similar to that of |
129 | * fc_remote_port_chkready(). |
130 | */ |
131 | static inline int srp_chkready(struct srp_rport *rport) |
132 | { |
133 | switch (rport->state) { |
134 | case SRP_RPORT_RUNNING: |
135 | case SRP_RPORT_BLOCKED: |
136 | default: |
137 | return 0; |
138 | case SRP_RPORT_FAIL_FAST: |
139 | return DID_TRANSPORT_FAILFAST << 16; |
140 | case SRP_RPORT_LOST: |
141 | return DID_NO_CONNECT << 16; |
142 | } |
143 | } |
144 | |
145 | #endif |
146 | |