diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/s390/scsi/zfcp_unit.c | 263 |
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..e67bf7388 --- /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_enqueue - enqueue unit to unit list of a port. + * @port: pointer to port where unit is added + * @fcp_lun: FCP LUN of unit to be enqueued + * 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); + } + + put_device(&unit->dev); + + device_unregister(&unit->dev); + + return 0; +} |