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