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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef SCSI_TRANSPORT_SRP_H3#define SCSI_TRANSPORT_SRP_H4 5#include <linux/transport_class.h>6#include <linux/types.h>7#include <linux/mutex.h>8 9#define SRP_RPORT_ROLE_INITIATOR 010#define SRP_RPORT_ROLE_TARGET 111 12struct srp_rport_identifiers {13 u8 port_id[16];14 u8 roles;15};16 17/**18 * enum srp_rport_state - SRP transport layer state19 * @SRP_RPORT_RUNNING: Transport layer operational.20 * @SRP_RPORT_BLOCKED: Transport layer not operational; fast I/O fail timer21 * 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 */25enum 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 port34 *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 */53struct 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 - template for SRP initiator drivers78 *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 and81 * dev_loss_tmo sysfs attribute for an rport.82 * @reset_timer_if_blocked: Whether or srp_timed_out() should reset the command83 * 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 also88 * srp_reconnect_rport().89 * @terminate_rport_io: Callback function for terminating all outstanding I/O90 * requests for an rport.91 * @rport_delete: Callback function that deletes an rport.92 */93struct 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 105extern struct scsi_transport_template *106srp_attach_transport(struct srp_function_template *);107extern void srp_release_transport(struct scsi_transport_template *);108 109extern void srp_rport_get(struct srp_rport *rport);110extern void srp_rport_put(struct srp_rport *rport);111extern struct srp_rport *srp_rport_add(struct Scsi_Host *,112 struct srp_rport_identifiers *);113extern void srp_rport_del(struct srp_rport *);114extern int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo,115 long dev_loss_tmo);116int srp_parse_tmo(int *tmo, const char *buf);117extern int srp_reconnect_rport(struct srp_rport *rport);118extern void srp_start_tl_fail_timers(struct srp_rport *rport);119extern void srp_remove_host(struct Scsi_Host *);120extern void srp_stop_rport_timers(struct srp_rport *rport);121enum scsi_timeout_action srp_timed_out(struct scsi_cmnd *scmd);122 123/**124 * srp_chkready() - evaluate the transport layer state before I/O125 * @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 of129 * fc_remote_port_chkready().130 */131static 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#endif146