Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 145 insertions, 0 deletions

diff --git a/include/scsi/scsi_transport_srp.h b/include/scsi/scsi_transport_srp.h
new file mode 100644
index 000000000..d22df1258
--- /dev/null
+++ b/include/scsi/scsi_transport_srp.h
@@ -0,0 +1,145 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef SCSI_TRANSPORT_SRP_H
+#define SCSI_TRANSPORT_SRP_H
+
+#include <linux/transport_class.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+
+#define SRP_RPORT_ROLE_INITIATOR 0
+#define SRP_RPORT_ROLE_TARGET 1
+
+struct srp_rport_identifiers {
+	u8 port_id[16];
+	u8 roles;
+};
+
+/**
+ * enum srp_rport_state - SRP transport layer state
+ * @SRP_RPORT_RUNNING:   Transport layer operational.
+ * @SRP_RPORT_BLOCKED:   Transport layer not operational; fast I/O fail timer
+ *                       is running and I/O has been blocked.
+ * @SRP_RPORT_FAIL_FAST: Fast I/O fail timer has expired; fail I/O fast.
+ * @SRP_RPORT_LOST:      Port is being removed.
+ */
+enum srp_rport_state {
+	SRP_RPORT_RUNNING,
+	SRP_RPORT_BLOCKED,
+	SRP_RPORT_FAIL_FAST,
+	SRP_RPORT_LOST,
+};
+
+/**
+ * struct srp_rport - SRP initiator or target port
+ *
+ * Fields that are relevant for SRP initiator and SRP target drivers:
+ * @dev:               Device associated with this rport.
+ * @port_id:           16-byte port identifier.
+ * @roles:             Role of this port - initiator or target.
+ *
+ * Fields that are only relevant for SRP initiator drivers:
+ * @lld_data:          LLD private data.
+ * @mutex:             Protects against concurrent rport reconnect /
+ *                     fast_io_fail / dev_loss_tmo activity.
+ * @state:             rport state.
+ * @reconnect_delay:   Reconnect delay in seconds.
+ * @failed_reconnects: Number of failed reconnect attempts.
+ * @reconnect_work:    Work structure used for scheduling reconnect attempts.
+ * @fast_io_fail_tmo:  Fast I/O fail timeout in seconds.
+ * @dev_loss_tmo:      Device loss timeout in seconds.
+ * @fast_io_fail_work: Work structure used for scheduling fast I/O fail work.
+ * @dev_loss_work:     Work structure used for scheduling device loss work.
+ */
+struct srp_rport {
+	/* for initiator and target drivers */
+
+	struct device dev;
+
+	u8 port_id[16];
+	u8 roles;
+
+	/* for initiator drivers */
+
+	void			*lld_data;
+
+	struct mutex		mutex;
+	enum srp_rport_state	state;
+	int			reconnect_delay;
+	int			failed_reconnects;
+	struct delayed_work	reconnect_work;
+	int			fast_io_fail_tmo;
+	int			dev_loss_tmo;
+	struct delayed_work	fast_io_fail_work;
+	struct delayed_work	dev_loss_work;
+};
+
+/**
+ * struct srp_function_template
+ *
+ * Fields that are only relevant for SRP initiator drivers:
+ * @has_rport_state: Whether or not to create the state, fast_io_fail_tmo and
+ *     dev_loss_tmo sysfs attribute for an rport.
+ * @reset_timer_if_blocked: Whether or srp_timed_out() should reset the command
+ *     timer if the device on which it has been queued is blocked.
+ * @reconnect_delay: If not NULL, points to the default reconnect_delay value.
+ * @fast_io_fail_tmo: If not NULL, points to the default fast_io_fail_tmo value.
+ * @dev_loss_tmo: If not NULL, points to the default dev_loss_tmo value.
+ * @reconnect: Callback function for reconnecting to the target. See also
+ *     srp_reconnect_rport().
+ * @terminate_rport_io: Callback function for terminating all outstanding I/O
+ *     requests for an rport.
+ * @rport_delete: Callback function that deletes an rport.
+ */
+struct srp_function_template {
+	/* for initiator drivers */
+	bool has_rport_state;
+	bool reset_timer_if_blocked;
+	int *reconnect_delay;
+	int *fast_io_fail_tmo;
+	int *dev_loss_tmo;
+	int (*reconnect)(struct srp_rport *rport);
+	void (*terminate_rport_io)(struct srp_rport *rport);
+	void (*rport_delete)(struct srp_rport *rport);
+};
+
+extern struct scsi_transport_template *
+srp_attach_transport(struct srp_function_template *);
+extern void srp_release_transport(struct scsi_transport_template *);
+
+extern void srp_rport_get(struct srp_rport *rport);
+extern void srp_rport_put(struct srp_rport *rport);
+extern struct srp_rport *srp_rport_add(struct Scsi_Host *,
+				       struct srp_rport_identifiers *);
+extern void srp_rport_del(struct srp_rport *);
+extern int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo,
+			 long dev_loss_tmo);
+int srp_parse_tmo(int *tmo, const char *buf);
+extern int srp_reconnect_rport(struct srp_rport *rport);
+extern void srp_start_tl_fail_timers(struct srp_rport *rport);
+extern void srp_remove_host(struct Scsi_Host *);
+extern void srp_stop_rport_timers(struct srp_rport *rport);
+enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd);
+
+/**
+ * srp_chkready() - evaluate the transport layer state before I/O
+ * @rport: SRP target port pointer.
+ *
+ * Returns a SCSI result code that can be returned by the LLD queuecommand()
+ * implementation. The role of this function is similar to that of
+ * fc_remote_port_chkready().
+ */
+static inline int srp_chkready(struct srp_rport *rport)
+{
+	switch (rport->state) {
+	case SRP_RPORT_RUNNING:
+	case SRP_RPORT_BLOCKED:
+	default:
+		return 0;
+	case SRP_RPORT_FAIL_FAST:
+		return DID_TRANSPORT_FAILFAST << 16;
+	case SRP_RPORT_LOST:
+		return DID_NO_CONNECT << 16;
+	}
+}
+
+#endif