1 files changed, 263 insertions, 0 deletions
diff --git a/drivers/s390/scsi/zfcp_unit.c b/drivers/s390/scsi/zfcp_unit.c
new file mode 100644
index 000000000..60f2a04f0
--- /dev/null
+++ b/drivers/s390/scsi/zfcp_unit.c
@@ -0,0 +1,263 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * zfcp device driver
+ *
+ * Tracking of manually configured LUNs and helper functions to
+ * register the LUNs with the SCSI midlayer.
+ *
+ * Copyright IBM Corp. 2010
+ */
+
+#include "zfcp_def.h"
+#include "zfcp_ext.h"
+
+/**
+ * zfcp_unit_scsi_scan - Register LUN with SCSI midlayer
+ * @unit: The zfcp LUN/unit to register
+ *
+ * When the SCSI midlayer is not allowed to automatically scan and
+ * attach SCSI devices, zfcp has to register the single devices with
+ * the SCSI midlayer.
+ */
+void zfcp_unit_scsi_scan(struct zfcp_unit *unit)
+{
+	struct fc_rport *rport = unit->port->rport;
+	u64 lun;
+
+	lun = scsilun_to_int((struct scsi_lun *) &unit->fcp_lun);
+
+	if (rport && rport->port_state == FC_PORTSTATE_ONLINE)
+		scsi_scan_target(&rport->dev, 0, rport->scsi_target_id, lun,
+				 SCSI_SCAN_MANUAL);
+}
+
+static void zfcp_unit_scsi_scan_work(struct work_struct *work)
+{
+	struct zfcp_unit *unit = container_of(work, struct zfcp_unit,
+					      scsi_work);
+
+	zfcp_unit_scsi_scan(unit);
+	put_device(&unit->dev);
+}
+
+/**
+ * zfcp_unit_queue_scsi_scan - Register configured units on port
+ * @port: The zfcp_port where to register units
+ *
+ * After opening a port, all units configured on this port have to be
+ * registered with the SCSI midlayer. This function should be called
+ * after calling fc_remote_port_add, so that the fc_rport is already
+ * ONLINE and the call to scsi_scan_target runs the same way as the
+ * call in the FC transport class.
+ */
+void zfcp_unit_queue_scsi_scan(struct zfcp_port *port)
+{
+	struct zfcp_unit *unit;
+
+	read_lock_irq(&port->unit_list_lock);
+	list_for_each_entry(unit, &port->unit_list, list) {
+		get_device(&unit->dev);
+		if (scsi_queue_work(port->adapter->scsi_host,
+				    &unit->scsi_work) <= 0)
+			put_device(&unit->dev);
+	}
+	read_unlock_irq(&port->unit_list_lock);
+}
+
+static struct zfcp_unit *_zfcp_unit_find(struct zfcp_port *port, u64 fcp_lun)
+{
+	struct zfcp_unit *unit;
+
+	list_for_each_entry(unit, &port->unit_list, list)
+		if (unit->fcp_lun == fcp_lun) {
+			get_device(&unit->dev);
+			return unit;
+		}
+
+	return NULL;
+}
+
+/**
+ * zfcp_unit_find - Find and return zfcp_unit with specified FCP LUN
+ * @port: zfcp_port where to look for the unit
+ * @fcp_lun: 64 Bit FCP LUN used to identify the zfcp_unit
+ *
+ * If zfcp_unit is found, a reference is acquired that has to be
+ * released later.
+ *
+ * Returns: Pointer to the zfcp_unit, or NULL if there is no zfcp_unit
+ *          with the specified FCP LUN.
+ */
+struct zfcp_unit *zfcp_unit_find(struct zfcp_port *port, u64 fcp_lun)
+{
+	struct zfcp_unit *unit;
+
+	read_lock_irq(&port->unit_list_lock);
+	unit = _zfcp_unit_find(port, fcp_lun);
+	read_unlock_irq(&port->unit_list_lock);
+	return unit;
+}
+
+/**
+ * zfcp_unit_release - Drop reference to zfcp_port and free memory of zfcp_unit.
+ * @dev: pointer to device in zfcp_unit
+ */
+static void zfcp_unit_release(struct device *dev)
+{
+	struct zfcp_unit *unit = container_of(dev, struct zfcp_unit, dev);
+
+	atomic_dec(&unit->port->units);
+	kfree(unit);
+}
+
+/**
+ * zfcp_unit_add - add unit to unit list of a port.
+ * @port: pointer to port where unit is added
+ * @fcp_lun: FCP LUN of unit to be added
+ * Returns: 0 success
+ *
+ * Sets up some unit internal structures and creates sysfs entry.
+ */
+int zfcp_unit_add(struct zfcp_port *port, u64 fcp_lun)
+{
+	struct zfcp_unit *unit;
+	int retval = 0;
+
+	mutex_lock(&zfcp_sysfs_port_units_mutex);
+	if (zfcp_sysfs_port_is_removing(port)) {
+		/* port is already gone */
+		retval = -ENODEV;
+		goto out;
+	}
+
+	unit = zfcp_unit_find(port, fcp_lun);
+	if (unit) {
+		put_device(&unit->dev);
+		retval = -EEXIST;
+		goto out;
+	}
+
+	unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
+	if (!unit) {
+		retval = -ENOMEM;
+		goto out;
+	}
+
+	unit->port = port;
+	unit->fcp_lun = fcp_lun;
+	unit->dev.parent = &port->dev;
+	unit->dev.release = zfcp_unit_release;
+	unit->dev.groups = zfcp_unit_attr_groups;
+	INIT_WORK(&unit->scsi_work, zfcp_unit_scsi_scan_work);
+
+	if (dev_set_name(&unit->dev, "0x%016llx",
+			 (unsigned long long) fcp_lun)) {
+		kfree(unit);
+		retval = -ENOMEM;
+		goto out;
+	}
+
+	if (device_register(&unit->dev)) {
+		put_device(&unit->dev);
+		retval = -ENOMEM;
+		goto out;
+	}
+
+	atomic_inc(&port->units); /* under zfcp_sysfs_port_units_mutex ! */
+
+	write_lock_irq(&port->unit_list_lock);
+	list_add_tail(&unit->list, &port->unit_list);
+	write_unlock_irq(&port->unit_list_lock);
+	/*
+	 * lock order: shost->scan_mutex before zfcp_sysfs_port_units_mutex
+	 * due to      zfcp_unit_scsi_scan() => zfcp_scsi_slave_alloc()
+	 */
+	mutex_unlock(&zfcp_sysfs_port_units_mutex);
+
+	zfcp_unit_scsi_scan(unit);
+	return retval;
+
+out:
+	mutex_unlock(&zfcp_sysfs_port_units_mutex);
+	return retval;
+}
+
+/**
+ * zfcp_unit_sdev - Return SCSI device for zfcp_unit
+ * @unit: The zfcp_unit where to get the SCSI device for
+ *
+ * Returns: scsi_device pointer on success, NULL if there is no SCSI
+ *          device for this zfcp_unit
+ *
+ * On success, the caller also holds a reference to the SCSI device
+ * that must be released with scsi_device_put.
+ */
+struct scsi_device *zfcp_unit_sdev(struct zfcp_unit *unit)
+{
+	struct Scsi_Host *shost;
+	struct zfcp_port *port;
+	u64 lun;
+
+	lun = scsilun_to_int((struct scsi_lun *) &unit->fcp_lun);
+	port = unit->port;
+	shost = port->adapter->scsi_host;
+	return scsi_device_lookup(shost, 0, port->starget_id, lun);
+}
+
+/**
+ * zfcp_unit_sdev_status - Return zfcp LUN status for SCSI device
+ * @unit: The unit to lookup the SCSI device for
+ *
+ * Returns the zfcp LUN status field of the SCSI device if the SCSI device
+ * for the zfcp_unit exists, 0 otherwise.
+ */
+unsigned int zfcp_unit_sdev_status(struct zfcp_unit *unit)
+{
+	unsigned int status = 0;
+	struct scsi_device *sdev;
+	struct zfcp_scsi_dev *zfcp_sdev;
+
+	sdev = zfcp_unit_sdev(unit);
+	if (sdev) {
+		zfcp_sdev = sdev_to_zfcp(sdev);
+		status = atomic_read(&zfcp_sdev->status);
+		scsi_device_put(sdev);
+	}
+
+	return status;
+}
+
+/**
+ * zfcp_unit_remove - Remove entry from list of configured units
+ * @port: The port where to remove the unit from the configuration
+ * @fcp_lun: The 64 bit LUN of the unit to remove
+ *
+ * Returns: -EINVAL if a unit with the specified LUN does not exist,
+ *          0 on success.
+ */
+int zfcp_unit_remove(struct zfcp_port *port, u64 fcp_lun)
+{
+	struct zfcp_unit *unit;
+	struct scsi_device *sdev;
+
+	write_lock_irq(&port->unit_list_lock);
+	unit = _zfcp_unit_find(port, fcp_lun);
+	if (unit)
+		list_del(&unit->list);
+	write_unlock_irq(&port->unit_list_lock);
+
+	if (!unit)
+		return -EINVAL;
+
+	sdev = zfcp_unit_sdev(unit);
+	if (sdev) {
+		scsi_remove_device(sdev);
+		scsi_device_put(sdev);
+	}
+
+	device_unregister(&unit->dev);
+
+	put_device(&unit->dev); /* undo _zfcp_unit_find() */
+
+	return 0;
+}