git.oblomov.eu Git - linux-2.6/blob - drivers/s390/scsi/zfcp_aux.c

   1 /*
   2  * zfcp device driver
   3  *
   4  * Module interface and handling of zfcp data structures.
   5  *
   6  * Copyright IBM Corporation 2002, 2009
   7  */
   8
   9 /*
  10  * Driver authors:
  11  *            Martin Peschke (originator of the driver)
  12  *            Raimund Schroeder
  13  *            Aron Zeh
  14  *            Wolfgang Taphorn
  15  *            Stefan Bader
  16  *            Heiko Carstens (kernel 2.6 port of the driver)
  17  *            Andreas Herrmann
  18  *            Maxim Shchetynin
  19  *            Volker Sameske
  20  *            Ralph Wuerthner
  21  *            Michael Loehr
  22  *            Swen Schillig
  23  *            Christof Schmitt
  24  *            Martin Petermann
  25  *            Sven Schuetz
  26  */
  27
  28 #define KMSG_COMPONENT "zfcp"
  29 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  30
  31 #include <linux/miscdevice.h>
  32 #include <linux/seq_file.h>
  33 #include "zfcp_ext.h"
  34
  35 #define ZFCP_BUS_ID_SIZE        20
  36
  37 MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
  38 MODULE_DESCRIPTION("FCP HBA driver");
  39 MODULE_LICENSE("GPL");
  40
  41 static char *init_device;
  42 module_param_named(device, init_device, charp, 0400);
  43 MODULE_PARM_DESC(device, "specify initial device");
  44
  45 static int zfcp_reqlist_alloc(struct zfcp_adapter *adapter)
  46 {
  47         int idx;
  48
  49         adapter->req_list = kcalloc(REQUEST_LIST_SIZE, sizeof(struct list_head),
  50                                     GFP_KERNEL);
  51         if (!adapter->req_list)
  52                 return -ENOMEM;
  53
  54         for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
  55                 INIT_LIST_HEAD(&adapter->req_list[idx]);
  56         return 0;
  57 }
  58
  59 /**
  60  * zfcp_reqlist_isempty - is the request list empty
  61  * @adapter: pointer to struct zfcp_adapter
  62  *
  63  * Returns: true if list is empty, false otherwise
  64  */
  65 int zfcp_reqlist_isempty(struct zfcp_adapter *adapter)
  66 {
  67         unsigned int idx;
  68
  69         for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
  70                 if (!list_empty(&adapter->req_list[idx]))
  71                         return 0;
  72         return 1;
  73 }
  74
  75 static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
  76 {
  77         struct zfcp_adapter *adapter;
  78         struct zfcp_port *port;
  79         struct zfcp_unit *unit;
  80
  81         down(&zfcp_data.config_sema);
  82         read_lock_irq(&zfcp_data.config_lock);
  83         adapter = zfcp_get_adapter_by_busid(busid);
  84         if (adapter)
  85                 zfcp_adapter_get(adapter);
  86         read_unlock_irq(&zfcp_data.config_lock);
  87
  88         if (!adapter)
  89                 goto out_adapter;
  90         port = zfcp_port_enqueue(adapter, wwpn, 0, 0);
  91         if (IS_ERR(port))
  92                 goto out_port;
  93         unit = zfcp_unit_enqueue(port, lun);
  94         if (IS_ERR(unit))
  95                 goto out_unit;
  96         up(&zfcp_data.config_sema);
  97         ccw_device_set_online(adapter->ccw_device);
  98
  99         zfcp_erp_wait(adapter);
 100         wait_event(adapter->erp_done_wqh,
 101                    !(atomic_read(&unit->status) &
 102                                 ZFCP_STATUS_UNIT_SCSI_WORK_PENDING));
 103
 104         down(&zfcp_data.config_sema);
 105         zfcp_unit_put(unit);
 106 out_unit:
 107         zfcp_port_put(port);
 108 out_port:
 109         zfcp_adapter_put(adapter);
 110 out_adapter:
 111         up(&zfcp_data.config_sema);
 112         return;
 113 }
 114
 115 static struct kmem_cache *zfcp_cache_create(int size, char *name)
 116 {
 117         int align = 1;
 118         while ((size - align) > 0)
 119                 align <<= 1;
 120         return kmem_cache_create(name , size, align, 0, NULL);
 121 }
 122
 123 static void __init zfcp_init_device_setup(char *devstr)
 124 {
 125         char *token;
 126         char *str;
 127         char busid[ZFCP_BUS_ID_SIZE];
 128         u64 wwpn, lun;
 129
 130         /* duplicate devstr and keep the original for sysfs presentation*/
 131         str = kmalloc(strlen(devstr) + 1, GFP_KERNEL);
 132         if (!str)
 133                 return;
 134
 135         strcpy(str, devstr);
 136
 137         token = strsep(&str, ",");
 138         if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
 139                 goto err_out;
 140         strncpy(busid, token, ZFCP_BUS_ID_SIZE);
 141
 142         token = strsep(&str, ",");
 143         if (!token || strict_strtoull(token, 0, (unsigned long long *) &wwpn))
 144                 goto err_out;
 145
 146         token = strsep(&str, ",");
 147         if (!token || strict_strtoull(token, 0, (unsigned long long *) &lun))
 148                 goto err_out;
 149
 150         kfree(str);
 151         zfcp_init_device_configure(busid, wwpn, lun);
 152         return;
 153
 154  err_out:
 155         kfree(str);
 156         pr_err("%s is not a valid SCSI device\n", devstr);
 157 }
 158
 159 static int __init zfcp_module_init(void)
 160 {
 161         int retval = -ENOMEM;
 162
 163         zfcp_data.fsf_req_qtcb_cache = zfcp_cache_create(
 164                         sizeof(struct zfcp_fsf_req_qtcb), "zfcp_fsf");
 165         if (!zfcp_data.fsf_req_qtcb_cache)
 166                 goto out;
 167
 168         zfcp_data.sr_buffer_cache = zfcp_cache_create(
 169                         sizeof(struct fsf_status_read_buffer), "zfcp_sr");
 170         if (!zfcp_data.sr_buffer_cache)
 171                 goto out_sr_cache;
 172
 173         zfcp_data.gid_pn_cache = zfcp_cache_create(
 174                         sizeof(struct zfcp_gid_pn_data), "zfcp_gid");
 175         if (!zfcp_data.gid_pn_cache)
 176                 goto out_gid_cache;
 177
 178         zfcp_data.work_queue = create_singlethread_workqueue("zfcp_wq");
 179
 180         sema_init(&zfcp_data.config_sema, 1);
 181         rwlock_init(&zfcp_data.config_lock);
 182
 183         zfcp_data.scsi_transport_template =
 184                 fc_attach_transport(&zfcp_transport_functions);
 185         if (!zfcp_data.scsi_transport_template)
 186                 goto out_transport;
 187
 188         retval = misc_register(&zfcp_cfdc_misc);
 189         if (retval) {
 190                 pr_err("Registering the misc device zfcp_cfdc failed\n");
 191                 goto out_misc;
 192         }
 193
 194         retval = zfcp_ccw_register();
 195         if (retval) {
 196                 pr_err("The zfcp device driver could not register with "
 197                        "the common I/O layer\n");
 198                 goto out_ccw_register;
 199         }
 200
 201         if (init_device)
 202                 zfcp_init_device_setup(init_device);
 203         return 0;
 204
 205 out_ccw_register:
 206         misc_deregister(&zfcp_cfdc_misc);
 207 out_misc:
 208         fc_release_transport(zfcp_data.scsi_transport_template);
 209 out_transport:
 210         kmem_cache_destroy(zfcp_data.gid_pn_cache);
 211 out_gid_cache:
 212         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 213 out_sr_cache:
 214         kmem_cache_destroy(zfcp_data.fsf_req_qtcb_cache);
 215 out:
 216         return retval;
 217 }
 218
 219 module_init(zfcp_module_init);
 220
 221 /**
 222  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
 223  * @port: pointer to port to search for unit
 224  * @fcp_lun: FCP LUN to search for
 225  *
 226  * Returns: pointer to zfcp_unit or NULL
 227  */
 228 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
 229 {
 230         struct zfcp_unit *unit;
 231
 232         list_for_each_entry(unit, &port->unit_list_head, list)
 233                 if ((unit->fcp_lun == fcp_lun) &&
 234                     !(atomic_read(&unit->status) & ZFCP_STATUS_COMMON_REMOVE))
 235                     return unit;
 236         return NULL;
 237 }
 238
 239 /**
 240  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
 241  * @adapter: pointer to adapter to search for port
 242  * @wwpn: wwpn to search for
 243  *
 244  * Returns: pointer to zfcp_port or NULL
 245  */
 246 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
 247                                         u64 wwpn)
 248 {
 249         struct zfcp_port *port;
 250
 251         list_for_each_entry(port, &adapter->port_list_head, list)
 252                 if ((port->wwpn == wwpn) &&
 253                     !(atomic_read(&port->status) & ZFCP_STATUS_COMMON_REMOVE))
 254                         return port;
 255         return NULL;
 256 }
 257
 258 static void zfcp_sysfs_unit_release(struct device *dev)
 259 {
 260         kfree(container_of(dev, struct zfcp_unit, sysfs_device));
 261 }
 262
 263 /**
 264  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 265  * @port: pointer to port where unit is added
 266  * @fcp_lun: FCP LUN of unit to be enqueued
 267  * Returns: pointer to enqueued unit on success, ERR_PTR on error
 268  * Locks: config_sema must be held to serialize changes to the unit list
 269  *
 270  * Sets up some unit internal structures and creates sysfs entry.
 271  */
 272 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
 273 {
 274         struct zfcp_unit *unit;
 275
 276         unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
 277         if (!unit)
 278                 return ERR_PTR(-ENOMEM);
 279
 280         atomic_set(&unit->refcount, 0);
 281         init_waitqueue_head(&unit->remove_wq);
 282
 283         unit->port = port;
 284         unit->fcp_lun = fcp_lun;
 285
 286         dev_set_name(&unit->sysfs_device, "0x%016llx",
 287                      (unsigned long long) fcp_lun);
 288         unit->sysfs_device.parent = &port->sysfs_device;
 289         unit->sysfs_device.release = zfcp_sysfs_unit_release;
 290         dev_set_drvdata(&unit->sysfs_device, unit);
 291
 292         /* mark unit unusable as long as sysfs registration is not complete */
 293         atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
 294
 295         spin_lock_init(&unit->latencies.lock);
 296         unit->latencies.write.channel.min = 0xFFFFFFFF;
 297         unit->latencies.write.fabric.min = 0xFFFFFFFF;
 298         unit->latencies.read.channel.min = 0xFFFFFFFF;
 299         unit->latencies.read.fabric.min = 0xFFFFFFFF;
 300         unit->latencies.cmd.channel.min = 0xFFFFFFFF;
 301         unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
 302
 303         read_lock_irq(&zfcp_data.config_lock);
 304         if (zfcp_get_unit_by_lun(port, fcp_lun)) {
 305                 read_unlock_irq(&zfcp_data.config_lock);
 306                 goto err_out_free;
 307         }
 308         read_unlock_irq(&zfcp_data.config_lock);
 309
 310         if (device_register(&unit->sysfs_device))
 311                 goto err_out_free;
 312
 313         if (sysfs_create_group(&unit->sysfs_device.kobj,
 314                                &zfcp_sysfs_unit_attrs)) {
 315                 device_unregister(&unit->sysfs_device);
 316                 return ERR_PTR(-EIO);
 317         }
 318
 319         zfcp_unit_get(unit);
 320
 321         write_lock_irq(&zfcp_data.config_lock);
 322         list_add_tail(&unit->list, &port->unit_list_head);
 323         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
 324         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
 325
 326         write_unlock_irq(&zfcp_data.config_lock);
 327
 328         zfcp_port_get(port);
 329
 330         return unit;
 331
 332 err_out_free:
 333         kfree(unit);
 334         return ERR_PTR(-EINVAL);
 335 }
 336
 337 /**
 338  * zfcp_unit_dequeue - dequeue unit
 339  * @unit: pointer to zfcp_unit
 340  *
 341  * waits until all work is done on unit and removes it then from the unit->list
 342  * of the associated port.
 343  */
 344 void zfcp_unit_dequeue(struct zfcp_unit *unit)
 345 {
 346         wait_event(unit->remove_wq, atomic_read(&unit->refcount) == 0);
 347         write_lock_irq(&zfcp_data.config_lock);
 348         list_del(&unit->list);
 349         write_unlock_irq(&zfcp_data.config_lock);
 350         zfcp_port_put(unit->port);
 351         sysfs_remove_group(&unit->sysfs_device.kobj, &zfcp_sysfs_unit_attrs);
 352         device_unregister(&unit->sysfs_device);
 353 }
 354
 355 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
 356 {
 357         /* must only be called with zfcp_data.config_sema taken */
 358         adapter->pool.fsf_req_erp =
 359                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
 360         if (!adapter->pool.fsf_req_erp)
 361                 return -ENOMEM;
 362
 363         adapter->pool.fsf_req_scsi =
 364                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
 365         if (!adapter->pool.fsf_req_scsi)
 366                 return -ENOMEM;
 367
 368         adapter->pool.fsf_req_abort =
 369                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
 370         if (!adapter->pool.fsf_req_abort)
 371                 return -ENOMEM;
 372
 373         adapter->pool.fsf_req_status_read =
 374                 mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
 375                                             sizeof(struct zfcp_fsf_req));
 376         if (!adapter->pool.fsf_req_status_read)
 377                 return -ENOMEM;
 378
 379         adapter->pool.data_status_read =
 380                 mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
 381                                          zfcp_data.sr_buffer_cache);
 382         if (!adapter->pool.data_status_read)
 383                 return -ENOMEM;
 384
 385         adapter->pool.data_gid_pn =
 386                 mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
 387         if (!adapter->pool.data_gid_pn)
 388                 return -ENOMEM;
 389
 390         return 0;
 391 }
 392
 393 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
 394 {
 395         /* zfcp_data.config_sema must be held */
 396         if (adapter->pool.fsf_req_erp)
 397                 mempool_destroy(adapter->pool.fsf_req_erp);
 398         if (adapter->pool.fsf_req_scsi)
 399                 mempool_destroy(adapter->pool.fsf_req_scsi);
 400         if (adapter->pool.fsf_req_abort)
 401                 mempool_destroy(adapter->pool.fsf_req_abort);
 402         if (adapter->pool.fsf_req_status_read)
 403                 mempool_destroy(adapter->pool.fsf_req_status_read);
 404         if (adapter->pool.data_status_read)
 405                 mempool_destroy(adapter->pool.data_status_read);
 406         if (adapter->pool.data_gid_pn)
 407                 mempool_destroy(adapter->pool.data_gid_pn);
 408 }
 409
 410 /**
 411  * zfcp_status_read_refill - refill the long running status_read_requests
 412  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
 413  *
 414  * Returns: 0 on success, 1 otherwise
 415  *
 416  * if there are 16 or more status_read requests missing an adapter_reopen
 417  * is triggered
 418  */
 419 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
 420 {
 421         while (atomic_read(&adapter->stat_miss) > 0)
 422                 if (zfcp_fsf_status_read(adapter)) {
 423                         if (atomic_read(&adapter->stat_miss) >= 16) {
 424                                 zfcp_erp_adapter_reopen(adapter, 0, "axsref1",
 425                                                         NULL);
 426                                 return 1;
 427                         }
 428                         break;
 429                 } else
 430                         atomic_dec(&adapter->stat_miss);
 431         return 0;
 432 }
 433
 434 static void _zfcp_status_read_scheduler(struct work_struct *work)
 435 {
 436         zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
 437                                              stat_work));
 438 }
 439
 440 static void zfcp_print_sl(struct seq_file *m, struct service_level *sl)
 441 {
 442         struct zfcp_adapter *adapter =
 443                 container_of(sl, struct zfcp_adapter, service_level);
 444
 445         seq_printf(m, "zfcp: %s microcode level %x\n",
 446                    dev_name(&adapter->ccw_device->dev),
 447                    adapter->fsf_lic_version);
 448 }
 449
 450 /**
 451  * zfcp_adapter_enqueue - enqueue a new adapter to the list
 452  * @ccw_device: pointer to the struct cc_device
 453  *
 454  * Returns:     0             if a new adapter was successfully enqueued
 455  *              -ENOMEM       if alloc failed
 456  * Enqueues an adapter at the end of the adapter list in the driver data.
 457  * All adapter internal structures are set up.
 458  * Proc-fs entries are also created.
 459  * locks:       config_sema must be held to serialise changes to the adapter list
 460  */
 461 int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 462 {
 463         struct zfcp_adapter *adapter;
 464
 465         /*
 466          * Note: It is safe to release the list_lock, as any list changes
 467          * are protected by the config_sema, which must be held to get here
 468          */
 469
 470         adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
 471         if (!adapter)
 472                 return -ENOMEM;
 473
 474         ccw_device->handler = NULL;
 475         adapter->ccw_device = ccw_device;
 476         atomic_set(&adapter->refcount, 0);
 477
 478         if (zfcp_qdio_allocate(adapter))
 479                 goto qdio_allocate_failed;
 480
 481         if (zfcp_allocate_low_mem_buffers(adapter))
 482                 goto failed_low_mem_buffers;
 483
 484         if (zfcp_reqlist_alloc(adapter))
 485                 goto failed_low_mem_buffers;
 486
 487         if (zfcp_adapter_debug_register(adapter))
 488                 goto debug_register_failed;
 489
 490         init_waitqueue_head(&adapter->remove_wq);
 491         init_waitqueue_head(&adapter->erp_thread_wqh);
 492         init_waitqueue_head(&adapter->erp_done_wqh);
 493
 494         INIT_LIST_HEAD(&adapter->port_list_head);
 495         INIT_LIST_HEAD(&adapter->erp_ready_head);
 496         INIT_LIST_HEAD(&adapter->erp_running_head);
 497
 498         spin_lock_init(&adapter->req_list_lock);
 499
 500         spin_lock_init(&adapter->hba_dbf_lock);
 501         spin_lock_init(&adapter->san_dbf_lock);
 502         spin_lock_init(&adapter->scsi_dbf_lock);
 503         spin_lock_init(&adapter->rec_dbf_lock);
 504         spin_lock_init(&adapter->req_q_lock);
 505         spin_lock_init(&adapter->qdio_stat_lock);
 506
 507         rwlock_init(&adapter->erp_lock);
 508         rwlock_init(&adapter->abort_lock);
 509
 510         sema_init(&adapter->erp_ready_sem, 0);
 511
 512         INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
 513         INIT_WORK(&adapter->scan_work, _zfcp_scan_ports_later);
 514
 515         adapter->service_level.seq_print = zfcp_print_sl;
 516
 517         /* mark adapter unusable as long as sysfs registration is not complete */
 518         atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
 519
 520         dev_set_drvdata(&ccw_device->dev, adapter);
 521
 522         if (sysfs_create_group(&ccw_device->dev.kobj,
 523                                &zfcp_sysfs_adapter_attrs))
 524                 goto sysfs_failed;
 525
 526         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
 527
 528         if (!zfcp_adapter_scsi_register(adapter))
 529                 return 0;
 530
 531 sysfs_failed:
 532         zfcp_adapter_debug_unregister(adapter);
 533 debug_register_failed:
 534         dev_set_drvdata(&ccw_device->dev, NULL);
 535         kfree(adapter->req_list);
 536 failed_low_mem_buffers:
 537         zfcp_free_low_mem_buffers(adapter);
 538 qdio_allocate_failed:
 539         zfcp_qdio_free(adapter);
 540         kfree(adapter);
 541         return -ENOMEM;
 542 }
 543
 544 /**
 545  * zfcp_adapter_dequeue - remove the adapter from the resource list
 546  * @adapter: pointer to struct zfcp_adapter which should be removed
 547  * locks:       adapter list write lock is assumed to be held by caller
 548  */
 549 void zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
 550 {
 551         int retval = 0;
 552         unsigned long flags;
 553
 554         cancel_work_sync(&adapter->scan_work);
 555         cancel_work_sync(&adapter->stat_work);
 556         cancel_delayed_work_sync(&adapter->nsp.work);
 557         zfcp_adapter_scsi_unregister(adapter);
 558         sysfs_remove_group(&adapter->ccw_device->dev.kobj,
 559                            &zfcp_sysfs_adapter_attrs);
 560         dev_set_drvdata(&adapter->ccw_device->dev, NULL);
 561         /* sanity check: no pending FSF requests */
 562         spin_lock_irqsave(&adapter->req_list_lock, flags);
 563         retval = zfcp_reqlist_isempty(adapter);
 564         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 565         if (!retval)
 566                 return;
 567
 568         zfcp_adapter_debug_unregister(adapter);
 569         zfcp_qdio_free(adapter);
 570         zfcp_free_low_mem_buffers(adapter);
 571         kfree(adapter->req_list);
 572         kfree(adapter->fc_stats);
 573         kfree(adapter->stats_reset_data);
 574         kfree(adapter);
 575 }
 576
 577 static void zfcp_sysfs_port_release(struct device *dev)
 578 {
 579         kfree(container_of(dev, struct zfcp_port, sysfs_device));
 580 }
 581
 582 /**
 583  * zfcp_port_enqueue - enqueue port to port list of adapter
 584  * @adapter: adapter where remote port is added
 585  * @wwpn: WWPN of the remote port to be enqueued
 586  * @status: initial status for the port
 587  * @d_id: destination id of the remote port to be enqueued
 588  * Returns: pointer to enqueued port on success, ERR_PTR on error
 589  * Locks: config_sema must be held to serialize changes to the port list
 590  *
 591  * All port internal structures are set up and the sysfs entry is generated.
 592  * d_id is used to enqueue ports with a well known address like the Directory
 593  * Service for nameserver lookup.
 594  */
 595 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 596                                      u32 status, u32 d_id)
 597 {
 598         struct zfcp_port *port;
 599         int retval;
 600
 601         port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
 602         if (!port)
 603                 return ERR_PTR(-ENOMEM);
 604
 605         init_waitqueue_head(&port->remove_wq);
 606         INIT_LIST_HEAD(&port->unit_list_head);
 607         INIT_WORK(&port->gid_pn_work, zfcp_erp_port_strategy_open_lookup);
 608         INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
 609         INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
 610
 611         port->adapter = adapter;
 612         port->d_id = d_id;
 613         port->wwpn = wwpn;
 614         port->rport_task = RPORT_NONE;
 615
 616         /* mark port unusable as long as sysfs registration is not complete */
 617         atomic_set_mask(status | ZFCP_STATUS_COMMON_REMOVE, &port->status);
 618         atomic_set(&port->refcount, 0);
 619
 620         dev_set_name(&port->sysfs_device, "0x%016llx",
 621                      (unsigned long long)wwpn);
 622         port->sysfs_device.parent = &adapter->ccw_device->dev;
 623
 624         port->sysfs_device.release = zfcp_sysfs_port_release;
 625         dev_set_drvdata(&port->sysfs_device, port);
 626
 627         read_lock_irq(&zfcp_data.config_lock);
 628         if (zfcp_get_port_by_wwpn(adapter, wwpn)) {
 629                 read_unlock_irq(&zfcp_data.config_lock);
 630                 goto err_out_free;
 631         }
 632         read_unlock_irq(&zfcp_data.config_lock);
 633
 634         if (device_register(&port->sysfs_device))
 635                 goto err_out_free;
 636
 637         retval = sysfs_create_group(&port->sysfs_device.kobj,
 638                                     &zfcp_sysfs_port_attrs);
 639
 640         if (retval) {
 641                 device_unregister(&port->sysfs_device);
 642                 goto err_out;
 643         }
 644
 645         zfcp_port_get(port);
 646
 647         write_lock_irq(&zfcp_data.config_lock);
 648         list_add_tail(&port->list, &adapter->port_list_head);
 649         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
 650         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &port->status);
 651
 652         write_unlock_irq(&zfcp_data.config_lock);
 653
 654         zfcp_adapter_get(adapter);
 655         return port;
 656
 657 err_out_free:
 658         kfree(port);
 659 err_out:
 660         return ERR_PTR(-EINVAL);
 661 }
 662
 663 /**
 664  * zfcp_port_dequeue - dequeues a port from the port list of the adapter
 665  * @port: pointer to struct zfcp_port which should be removed
 666  */
 667 void zfcp_port_dequeue(struct zfcp_port *port)
 668 {
 669         wait_event(port->remove_wq, atomic_read(&port->refcount) == 0);
 670         write_lock_irq(&zfcp_data.config_lock);
 671         list_del(&port->list);
 672         write_unlock_irq(&zfcp_data.config_lock);
 673         if (port->rport)
 674                 fc_remote_port_delete(port->rport);
 675         port->rport = NULL;
 676         zfcp_adapter_put(port->adapter);
 677         sysfs_remove_group(&port->sysfs_device.kobj, &zfcp_sysfs_port_attrs);
 678         device_unregister(&port->sysfs_device);
 679 }
 680
 681 /**
 682  * zfcp_sg_free_table - free memory used by scatterlists
 683  * @sg: pointer to scatterlist
 684  * @count: number of scatterlist which are to be free'ed
 685  * the scatterlist are expected to reference pages always
 686  */
 687 void zfcp_sg_free_table(struct scatterlist *sg, int count)
 688 {
 689         int i;
 690
 691         for (i = 0; i < count; i++, sg++)
 692                 if (sg)
 693                         free_page((unsigned long) sg_virt(sg));
 694                 else
 695                         break;
 696 }
 697
 698 /**
 699  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
 700  * @sg: pointer to struct scatterlist
 701  * @count: number of scatterlists which should be assigned with buffers
 702  * of size page
 703  *
 704  * Returns: 0 on success, -ENOMEM otherwise
 705  */
 706 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
 707 {
 708         void *addr;
 709         int i;
 710
 711         sg_init_table(sg, count);
 712         for (i = 0; i < count; i++, sg++) {
 713                 addr = (void *) get_zeroed_page(GFP_KERNEL);
 714                 if (!addr) {
 715                         zfcp_sg_free_table(sg, i);
 716                         return -ENOMEM;
 717                 }
 718                 sg_set_buf(sg, addr, PAGE_SIZE);
 719         }
 720         return 0;
 721 }