include/scsi/scsi_transport_srp.h

   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