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 blk_eh_timer_return 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