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1// SPDX-License-Identifier: GPL-2.02/*3 * zfcp device driver4 *5 * Tracking of manually configured LUNs and helper functions to6 * register the LUNs with the SCSI midlayer.7 *8 * Copyright IBM Corp. 20109 */10 11#include "zfcp_def.h"12#include "zfcp_ext.h"13 14/**15 * zfcp_unit_scsi_scan - Register LUN with SCSI midlayer16 * @unit: The zfcp LUN/unit to register17 *18 * When the SCSI midlayer is not allowed to automatically scan and19 * attach SCSI devices, zfcp has to register the single devices with20 * the SCSI midlayer.21 */22void zfcp_unit_scsi_scan(struct zfcp_unit *unit)23{24 struct fc_rport *rport = unit->port->rport;25 u64 lun;26 27 lun = scsilun_to_int((struct scsi_lun *) &unit->fcp_lun);28 29 if (rport && rport->port_state == FC_PORTSTATE_ONLINE)30 scsi_scan_target(&rport->dev, 0, rport->scsi_target_id, lun,31 SCSI_SCAN_MANUAL);32}33 34static void zfcp_unit_scsi_scan_work(struct work_struct *work)35{36 struct zfcp_unit *unit = container_of(work, struct zfcp_unit,37 scsi_work);38 39 zfcp_unit_scsi_scan(unit);40 put_device(&unit->dev);41}42 43/**44 * zfcp_unit_queue_scsi_scan - Register configured units on port45 * @port: The zfcp_port where to register units46 *47 * After opening a port, all units configured on this port have to be48 * registered with the SCSI midlayer. This function should be called49 * after calling fc_remote_port_add, so that the fc_rport is already50 * ONLINE and the call to scsi_scan_target runs the same way as the51 * call in the FC transport class.52 */53void zfcp_unit_queue_scsi_scan(struct zfcp_port *port)54{55 struct zfcp_unit *unit;56 57 read_lock_irq(&port->unit_list_lock);58 list_for_each_entry(unit, &port->unit_list, list) {59 get_device(&unit->dev);60 if (scsi_queue_work(port->adapter->scsi_host,61 &unit->scsi_work) <= 0)62 put_device(&unit->dev);63 }64 read_unlock_irq(&port->unit_list_lock);65}66 67static struct zfcp_unit *_zfcp_unit_find(struct zfcp_port *port, u64 fcp_lun)68{69 struct zfcp_unit *unit;70 71 list_for_each_entry(unit, &port->unit_list, list)72 if (unit->fcp_lun == fcp_lun) {73 get_device(&unit->dev);74 return unit;75 }76 77 return NULL;78}79 80/**81 * zfcp_unit_find - Find and return zfcp_unit with specified FCP LUN82 * @port: zfcp_port where to look for the unit83 * @fcp_lun: 64 Bit FCP LUN used to identify the zfcp_unit84 *85 * If zfcp_unit is found, a reference is acquired that has to be86 * released later.87 *88 * Returns: Pointer to the zfcp_unit, or NULL if there is no zfcp_unit89 * with the specified FCP LUN.90 */91struct zfcp_unit *zfcp_unit_find(struct zfcp_port *port, u64 fcp_lun)92{93 struct zfcp_unit *unit;94 95 read_lock_irq(&port->unit_list_lock);96 unit = _zfcp_unit_find(port, fcp_lun);97 read_unlock_irq(&port->unit_list_lock);98 return unit;99}100 101/**102 * zfcp_unit_release - Drop reference to zfcp_port and free memory of zfcp_unit.103 * @dev: pointer to device in zfcp_unit104 */105static void zfcp_unit_release(struct device *dev)106{107 struct zfcp_unit *unit = container_of(dev, struct zfcp_unit, dev);108 109 atomic_dec(&unit->port->units);110 kfree(unit);111}112 113/**114 * zfcp_unit_add - add unit to unit list of a port.115 * @port: pointer to port where unit is added116 * @fcp_lun: FCP LUN of unit to be added117 * Returns: 0 success118 *119 * Sets up some unit internal structures and creates sysfs entry.120 */121int zfcp_unit_add(struct zfcp_port *port, u64 fcp_lun)122{123 struct zfcp_unit *unit;124 int retval = 0;125 126 mutex_lock(&zfcp_sysfs_port_units_mutex);127 if (zfcp_sysfs_port_is_removing(port)) {128 /* port is already gone */129 retval = -ENODEV;130 goto out;131 }132 133 unit = zfcp_unit_find(port, fcp_lun);134 if (unit) {135 put_device(&unit->dev);136 retval = -EEXIST;137 goto out;138 }139 140 unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);141 if (!unit) {142 retval = -ENOMEM;143 goto out;144 }145 146 unit->port = port;147 unit->fcp_lun = fcp_lun;148 unit->dev.parent = &port->dev;149 unit->dev.release = zfcp_unit_release;150 unit->dev.groups = zfcp_unit_attr_groups;151 INIT_WORK(&unit->scsi_work, zfcp_unit_scsi_scan_work);152 153 if (dev_set_name(&unit->dev, "0x%016llx",154 (unsigned long long) fcp_lun)) {155 kfree(unit);156 retval = -ENOMEM;157 goto out;158 }159 160 if (device_register(&unit->dev)) {161 put_device(&unit->dev);162 retval = -ENOMEM;163 goto out;164 }165 166 atomic_inc(&port->units); /* under zfcp_sysfs_port_units_mutex ! */167 168 write_lock_irq(&port->unit_list_lock);169 list_add_tail(&unit->list, &port->unit_list);170 write_unlock_irq(&port->unit_list_lock);171 /*172 * lock order: shost->scan_mutex before zfcp_sysfs_port_units_mutex173 * due to zfcp_unit_scsi_scan() => zfcp_scsi_slave_alloc()174 */175 mutex_unlock(&zfcp_sysfs_port_units_mutex);176 177 zfcp_unit_scsi_scan(unit);178 return retval;179 180out:181 mutex_unlock(&zfcp_sysfs_port_units_mutex);182 return retval;183}184 185/**186 * zfcp_unit_sdev - Return SCSI device for zfcp_unit187 * @unit: The zfcp_unit where to get the SCSI device for188 *189 * Returns: scsi_device pointer on success, NULL if there is no SCSI190 * device for this zfcp_unit191 *192 * On success, the caller also holds a reference to the SCSI device193 * that must be released with scsi_device_put.194 */195struct scsi_device *zfcp_unit_sdev(struct zfcp_unit *unit)196{197 struct Scsi_Host *shost;198 struct zfcp_port *port;199 u64 lun;200 201 lun = scsilun_to_int((struct scsi_lun *) &unit->fcp_lun);202 port = unit->port;203 shost = port->adapter->scsi_host;204 return scsi_device_lookup(shost, 0, port->starget_id, lun);205}206 207/**208 * zfcp_unit_sdev_status - Return zfcp LUN status for SCSI device209 * @unit: The unit to lookup the SCSI device for210 *211 * Returns the zfcp LUN status field of the SCSI device if the SCSI device212 * for the zfcp_unit exists, 0 otherwise.213 */214unsigned int zfcp_unit_sdev_status(struct zfcp_unit *unit)215{216 unsigned int status = 0;217 struct scsi_device *sdev;218 struct zfcp_scsi_dev *zfcp_sdev;219 220 sdev = zfcp_unit_sdev(unit);221 if (sdev) {222 zfcp_sdev = sdev_to_zfcp(sdev);223 status = atomic_read(&zfcp_sdev->status);224 scsi_device_put(sdev);225 }226 227 return status;228}229 230/**231 * zfcp_unit_remove - Remove entry from list of configured units232 * @port: The port where to remove the unit from the configuration233 * @fcp_lun: The 64 bit LUN of the unit to remove234 *235 * Returns: -EINVAL if a unit with the specified LUN does not exist,236 * 0 on success.237 */238int zfcp_unit_remove(struct zfcp_port *port, u64 fcp_lun)239{240 struct zfcp_unit *unit;241 struct scsi_device *sdev;242 243 write_lock_irq(&port->unit_list_lock);244 unit = _zfcp_unit_find(port, fcp_lun);245 if (unit)246 list_del(&unit->list);247 write_unlock_irq(&port->unit_list_lock);248 249 if (!unit)250 return -EINVAL;251 252 sdev = zfcp_unit_sdev(unit);253 if (sdev) {254 scsi_remove_device(sdev);255 scsi_device_put(sdev);256 }257 258 device_unregister(&unit->dev);259 260 put_device(&unit->dev); /* undo _zfcp_unit_find() */261 262 return 0;263}264