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, 2010
   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 <linux/slab.h>
  34 #include "zfcp_ext.h"
  35 #include "zfcp_fc.h"
  36 #include "zfcp_reqlist.h"
  37
  38 #define ZFCP_BUS_ID_SIZE        20
  39
  40 MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
  41 MODULE_DESCRIPTION("FCP HBA driver");
  42 MODULE_LICENSE("GPL");
  43
  44 static char *init_device;
  45 module_param_named(device, init_device, charp, 0400);
  46 MODULE_PARM_DESC(device, "specify initial device");
  47
  48 static struct kmem_cache *zfcp_cache_hw_align(const char *name,
  49                                               unsigned long size)
  50 {
  51         return kmem_cache_create(name, size, roundup_pow_of_two(size), 0, NULL);
  52 }
  53
  54 static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
  55 {
  56         struct ccw_device *cdev;
  57         struct zfcp_adapter *adapter;
  58         struct zfcp_port *port;
  59         struct zfcp_unit *unit;
  60
  61         cdev = get_ccwdev_by_busid(&zfcp_ccw_driver, busid);
  62         if (!cdev)
  63                 return;
  64
  65         if (ccw_device_set_online(cdev))
  66                 goto out_ccw_device;
  67
  68         adapter = zfcp_ccw_adapter_by_cdev(cdev);
  69         if (!adapter)
  70                 goto out_ccw_device;
  71
  72         port = zfcp_get_port_by_wwpn(adapter, wwpn);
  73         if (!port)
  74                 goto out_port;
  75
  76         unit = zfcp_unit_enqueue(port, lun);
  77         if (IS_ERR(unit))
  78                 goto out_unit;
  79
  80         zfcp_erp_unit_reopen(unit, 0, "auidc_1", NULL);
  81         zfcp_erp_wait(adapter);
  82         flush_work(&unit->scsi_work);
  83
  84 out_unit:
  85         put_device(&port->dev);
  86 out_port:
  87         zfcp_ccw_adapter_put(adapter);
  88 out_ccw_device:
  89         put_device(&cdev->dev);
  90         return;
  91 }
  92
  93 static void __init zfcp_init_device_setup(char *devstr)
  94 {
  95         char *token;
  96         char *str, *str_saved;
  97         char busid[ZFCP_BUS_ID_SIZE];
  98         u64 wwpn, lun;
  99
 100         /* duplicate devstr and keep the original for sysfs presentation*/
 101         str_saved = kstrdup(devstr, GFP_KERNEL);
 102         str = str_saved;
 103         if (!str)
 104                 return;
 105
 106         token = strsep(&str, ",");
 107         if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
 108                 goto err_out;
 109         strncpy(busid, token, ZFCP_BUS_ID_SIZE);
 110
 111         token = strsep(&str, ",");
 112         if (!token || strict_strtoull(token, 0, (unsigned long long *) &wwpn))
 113                 goto err_out;
 114
 115         token = strsep(&str, ",");
 116         if (!token || strict_strtoull(token, 0, (unsigned long long *) &lun))
 117                 goto err_out;
 118
 119         kfree(str_saved);
 120         zfcp_init_device_configure(busid, wwpn, lun);
 121         return;
 122
 123 err_out:
 124         kfree(str_saved);
 125         pr_err("%s is not a valid SCSI device\n", devstr);
 126 }
 127
 128 static int __init zfcp_module_init(void)
 129 {
 130         int retval = -ENOMEM;
 131
 132         zfcp_data.gpn_ft_cache = zfcp_cache_hw_align("zfcp_gpn",
 133                                         sizeof(struct zfcp_fc_gpn_ft_req));
 134         if (!zfcp_data.gpn_ft_cache)
 135                 goto out;
 136
 137         zfcp_data.qtcb_cache = zfcp_cache_hw_align("zfcp_qtcb",
 138                                         sizeof(struct fsf_qtcb));
 139         if (!zfcp_data.qtcb_cache)
 140                 goto out_qtcb_cache;
 141
 142         zfcp_data.sr_buffer_cache = zfcp_cache_hw_align("zfcp_sr",
 143                                         sizeof(struct fsf_status_read_buffer));
 144         if (!zfcp_data.sr_buffer_cache)
 145                 goto out_sr_cache;
 146
 147         zfcp_data.gid_pn_cache = zfcp_cache_hw_align("zfcp_gid",
 148                                         sizeof(struct zfcp_fc_gid_pn));
 149         if (!zfcp_data.gid_pn_cache)
 150                 goto out_gid_cache;
 151
 152         zfcp_data.adisc_cache = zfcp_cache_hw_align("zfcp_adisc",
 153                                         sizeof(struct zfcp_fc_els_adisc));
 154         if (!zfcp_data.adisc_cache)
 155                 goto out_adisc_cache;
 156
 157         zfcp_data.scsi_transport_template =
 158                 fc_attach_transport(&zfcp_transport_functions);
 159         if (!zfcp_data.scsi_transport_template)
 160                 goto out_transport;
 161
 162         retval = misc_register(&zfcp_cfdc_misc);
 163         if (retval) {
 164                 pr_err("Registering the misc device zfcp_cfdc failed\n");
 165                 goto out_misc;
 166         }
 167
 168         retval = ccw_driver_register(&zfcp_ccw_driver);
 169         if (retval) {
 170                 pr_err("The zfcp device driver could not register with "
 171                        "the common I/O layer\n");
 172                 goto out_ccw_register;
 173         }
 174
 175         if (init_device)
 176                 zfcp_init_device_setup(init_device);
 177         return 0;
 178
 179 out_ccw_register:
 180         misc_deregister(&zfcp_cfdc_misc);
 181 out_misc:
 182         fc_release_transport(zfcp_data.scsi_transport_template);
 183 out_transport:
 184         kmem_cache_destroy(zfcp_data.adisc_cache);
 185 out_adisc_cache:
 186         kmem_cache_destroy(zfcp_data.gid_pn_cache);
 187 out_gid_cache:
 188         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 189 out_sr_cache:
 190         kmem_cache_destroy(zfcp_data.qtcb_cache);
 191 out_qtcb_cache:
 192         kmem_cache_destroy(zfcp_data.gpn_ft_cache);
 193 out:
 194         return retval;
 195 }
 196
 197 module_init(zfcp_module_init);
 198
 199 static void __exit zfcp_module_exit(void)
 200 {
 201         ccw_driver_unregister(&zfcp_ccw_driver);
 202         misc_deregister(&zfcp_cfdc_misc);
 203         fc_release_transport(zfcp_data.scsi_transport_template);
 204         kmem_cache_destroy(zfcp_data.adisc_cache);
 205         kmem_cache_destroy(zfcp_data.gid_pn_cache);
 206         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 207         kmem_cache_destroy(zfcp_data.qtcb_cache);
 208         kmem_cache_destroy(zfcp_data.gpn_ft_cache);
 209 }
 210
 211 module_exit(zfcp_module_exit);
 212
 213 /**
 214  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
 215  * @port: pointer to port to search for unit
 216  * @fcp_lun: FCP LUN to search for
 217  *
 218  * Returns: pointer to zfcp_unit or NULL
 219  */
 220 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
 221 {
 222         unsigned long flags;
 223         struct zfcp_unit *unit;
 224
 225         read_lock_irqsave(&port->unit_list_lock, flags);
 226         list_for_each_entry(unit, &port->unit_list, list)
 227                 if (unit->fcp_lun == fcp_lun) {
 228                         if (!get_device(&unit->dev))
 229                                 unit = NULL;
 230                         read_unlock_irqrestore(&port->unit_list_lock, flags);
 231                         return unit;
 232                 }
 233         read_unlock_irqrestore(&port->unit_list_lock, flags);
 234         return NULL;
 235 }
 236
 237 /**
 238  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
 239  * @adapter: pointer to adapter to search for port
 240  * @wwpn: wwpn to search for
 241  *
 242  * Returns: pointer to zfcp_port or NULL
 243  */
 244 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
 245                                         u64 wwpn)
 246 {
 247         unsigned long flags;
 248         struct zfcp_port *port;
 249
 250         read_lock_irqsave(&adapter->port_list_lock, flags);
 251         list_for_each_entry(port, &adapter->port_list, list)
 252                 if (port->wwpn == wwpn) {
 253                         if (!get_device(&port->dev))
 254                                 port = NULL;
 255                         read_unlock_irqrestore(&adapter->port_list_lock, flags);
 256                         return port;
 257                 }
 258         read_unlock_irqrestore(&adapter->port_list_lock, flags);
 259         return NULL;
 260 }
 261
 262 /**
 263  * zfcp_unit_release - dequeue unit
 264  * @dev: pointer to device
 265  *
 266  * waits until all work is done on unit and removes it then from the unit->list
 267  * of the associated port.
 268  */
 269 static void zfcp_unit_release(struct device *dev)
 270 {
 271         struct zfcp_unit *unit = container_of(dev, struct zfcp_unit, dev);
 272
 273         put_device(&unit->port->dev);
 274         kfree(unit);
 275 }
 276
 277 /**
 278  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 279  * @port: pointer to port where unit is added
 280  * @fcp_lun: FCP LUN of unit to be enqueued
 281  * Returns: pointer to enqueued unit on success, ERR_PTR on error
 282  *
 283  * Sets up some unit internal structures and creates sysfs entry.
 284  */
 285 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
 286 {
 287         struct zfcp_unit *unit;
 288         int retval = -ENOMEM;
 289
 290         get_device(&port->dev);
 291
 292         unit = zfcp_get_unit_by_lun(port, fcp_lun);
 293         if (unit) {
 294                 put_device(&unit->dev);
 295                 retval = -EEXIST;
 296                 goto err_out;
 297         }
 298
 299         unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
 300         if (!unit)
 301                 goto err_out;
 302
 303         unit->port = port;
 304         unit->fcp_lun = fcp_lun;
 305         unit->dev.parent = &port->dev;
 306         unit->dev.release = zfcp_unit_release;
 307
 308         if (dev_set_name(&unit->dev, "0x%016llx",
 309                          (unsigned long long) fcp_lun)) {
 310                 kfree(unit);
 311                 goto err_out;
 312         }
 313         retval = -EINVAL;
 314
 315         INIT_WORK(&unit->scsi_work, zfcp_scsi_scan_work);
 316
 317         spin_lock_init(&unit->latencies.lock);
 318         unit->latencies.write.channel.min = 0xFFFFFFFF;
 319         unit->latencies.write.fabric.min = 0xFFFFFFFF;
 320         unit->latencies.read.channel.min = 0xFFFFFFFF;
 321         unit->latencies.read.fabric.min = 0xFFFFFFFF;
 322         unit->latencies.cmd.channel.min = 0xFFFFFFFF;
 323         unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
 324
 325         if (device_register(&unit->dev)) {
 326                 put_device(&unit->dev);
 327                 goto err_out;
 328         }
 329
 330         if (sysfs_create_group(&unit->dev.kobj, &zfcp_sysfs_unit_attrs))
 331                 goto err_out_put;
 332
 333         write_lock_irq(&port->unit_list_lock);
 334         list_add_tail(&unit->list, &port->unit_list);
 335         write_unlock_irq(&port->unit_list_lock);
 336
 337         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
 338
 339         return unit;
 340
 341 err_out_put:
 342         device_unregister(&unit->dev);
 343 err_out:
 344         put_device(&port->dev);
 345         return ERR_PTR(retval);
 346 }
 347
 348 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
 349 {
 350         adapter->pool.erp_req =
 351                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 352         if (!adapter->pool.erp_req)
 353                 return -ENOMEM;
 354
 355         adapter->pool.gid_pn_req =
 356                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 357         if (!adapter->pool.gid_pn_req)
 358                 return -ENOMEM;
 359
 360         adapter->pool.scsi_req =
 361                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 362         if (!adapter->pool.scsi_req)
 363                 return -ENOMEM;
 364
 365         adapter->pool.scsi_abort =
 366                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 367         if (!adapter->pool.scsi_abort)
 368                 return -ENOMEM;
 369
 370         adapter->pool.status_read_req =
 371                 mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
 372                                             sizeof(struct zfcp_fsf_req));
 373         if (!adapter->pool.status_read_req)
 374                 return -ENOMEM;
 375
 376         adapter->pool.qtcb_pool =
 377                 mempool_create_slab_pool(4, zfcp_data.qtcb_cache);
 378         if (!adapter->pool.qtcb_pool)
 379                 return -ENOMEM;
 380
 381         adapter->pool.status_read_data =
 382                 mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
 383                                          zfcp_data.sr_buffer_cache);
 384         if (!adapter->pool.status_read_data)
 385                 return -ENOMEM;
 386
 387         adapter->pool.gid_pn =
 388                 mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
 389         if (!adapter->pool.gid_pn)
 390                 return -ENOMEM;
 391
 392         return 0;
 393 }
 394
 395 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
 396 {
 397         if (adapter->pool.erp_req)
 398                 mempool_destroy(adapter->pool.erp_req);
 399         if (adapter->pool.scsi_req)
 400                 mempool_destroy(adapter->pool.scsi_req);
 401         if (adapter->pool.scsi_abort)
 402                 mempool_destroy(adapter->pool.scsi_abort);
 403         if (adapter->pool.qtcb_pool)
 404                 mempool_destroy(adapter->pool.qtcb_pool);
 405         if (adapter->pool.status_read_req)
 406                 mempool_destroy(adapter->pool.status_read_req);
 407         if (adapter->pool.status_read_data)
 408                 mempool_destroy(adapter->pool.status_read_data);
 409         if (adapter->pool.gid_pn)
 410                 mempool_destroy(adapter->pool.gid_pn);
 411 }
 412
 413 /**
 414  * zfcp_status_read_refill - refill the long running status_read_requests
 415  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
 416  *
 417  * Returns: 0 on success, 1 otherwise
 418  *
 419  * if there are 16 or more status_read requests missing an adapter_reopen
 420  * is triggered
 421  */
 422 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
 423 {
 424         while (atomic_read(&adapter->stat_miss) > 0)
 425                 if (zfcp_fsf_status_read(adapter->qdio)) {
 426                         if (atomic_read(&adapter->stat_miss) >=
 427                             adapter->stat_read_buf_num) {
 428                                 zfcp_erp_adapter_reopen(adapter, 0, "axsref1",
 429                                                         NULL);
 430                                 return 1;
 431                         }
 432                         break;
 433                 } else
 434                         atomic_dec(&adapter->stat_miss);
 435         return 0;
 436 }
 437
 438 static void _zfcp_status_read_scheduler(struct work_struct *work)
 439 {
 440         zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
 441                                              stat_work));
 442 }
 443
 444 static void zfcp_print_sl(struct seq_file *m, struct service_level *sl)
 445 {
 446         struct zfcp_adapter *adapter =
 447                 container_of(sl, struct zfcp_adapter, service_level);
 448
 449         seq_printf(m, "zfcp: %s microcode level %x\n",
 450                    dev_name(&adapter->ccw_device->dev),
 451                    adapter->fsf_lic_version);
 452 }
 453
 454 static int zfcp_setup_adapter_work_queue(struct zfcp_adapter *adapter)
 455 {
 456         char name[TASK_COMM_LEN];
 457
 458         snprintf(name, sizeof(name), "zfcp_q_%s",
 459                  dev_name(&adapter->ccw_device->dev));
 460         adapter->work_queue = create_singlethread_workqueue(name);
 461
 462         if (adapter->work_queue)
 463                 return 0;
 464         return -ENOMEM;
 465 }
 466
 467 static void zfcp_destroy_adapter_work_queue(struct zfcp_adapter *adapter)
 468 {
 469         if (adapter->work_queue)
 470                 destroy_workqueue(adapter->work_queue);
 471         adapter->work_queue = NULL;
 472
 473 }
 474
 475 /**
 476  * zfcp_adapter_enqueue - enqueue a new adapter to the list
 477  * @ccw_device: pointer to the struct cc_device
 478  *
 479  * Returns:     struct zfcp_adapter*
 480  * Enqueues an adapter at the end of the adapter list in the driver data.
 481  * All adapter internal structures are set up.
 482  * Proc-fs entries are also created.
 483  */
 484 struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 485 {
 486         struct zfcp_adapter *adapter;
 487
 488         if (!get_device(&ccw_device->dev))
 489                 return ERR_PTR(-ENODEV);
 490
 491         adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
 492         if (!adapter) {
 493                 put_device(&ccw_device->dev);
 494                 return ERR_PTR(-ENOMEM);
 495         }
 496
 497         kref_init(&adapter->ref);
 498
 499         ccw_device->handler = NULL;
 500         adapter->ccw_device = ccw_device;
 501
 502         INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
 503         INIT_WORK(&adapter->scan_work, zfcp_fc_scan_ports);
 504
 505         if (zfcp_qdio_setup(adapter))
 506                 goto failed;
 507
 508         if (zfcp_allocate_low_mem_buffers(adapter))
 509                 goto failed;
 510
 511         adapter->req_list = zfcp_reqlist_alloc();
 512         if (!adapter->req_list)
 513                 goto failed;
 514
 515         if (zfcp_dbf_adapter_register(adapter))
 516                 goto failed;
 517
 518         if (zfcp_setup_adapter_work_queue(adapter))
 519                 goto failed;
 520
 521         if (zfcp_fc_gs_setup(adapter))
 522                 goto failed;
 523
 524         rwlock_init(&adapter->port_list_lock);
 525         INIT_LIST_HEAD(&adapter->port_list);
 526
 527         INIT_LIST_HEAD(&adapter->events.list);
 528         INIT_WORK(&adapter->events.work, zfcp_fc_post_event);
 529         spin_lock_init(&adapter->events.list_lock);
 530
 531         init_waitqueue_head(&adapter->erp_ready_wq);
 532         init_waitqueue_head(&adapter->erp_done_wqh);
 533
 534         INIT_LIST_HEAD(&adapter->erp_ready_head);
 535         INIT_LIST_HEAD(&adapter->erp_running_head);
 536
 537         rwlock_init(&adapter->erp_lock);
 538         rwlock_init(&adapter->abort_lock);
 539
 540         if (zfcp_erp_thread_setup(adapter))
 541                 goto failed;
 542
 543         adapter->service_level.seq_print = zfcp_print_sl;
 544
 545         dev_set_drvdata(&ccw_device->dev, adapter);
 546
 547         if (sysfs_create_group(&ccw_device->dev.kobj,
 548                                &zfcp_sysfs_adapter_attrs))
 549                 goto failed;
 550
 551         /* report size limit per scatter-gather segment */
 552         adapter->dma_parms.max_segment_size = ZFCP_QDIO_SBALE_LEN;
 553         adapter->ccw_device->dev.dma_parms = &adapter->dma_parms;
 554
 555         if (!zfcp_adapter_scsi_register(adapter))
 556                 return adapter;
 557
 558 failed:
 559         zfcp_adapter_unregister(adapter);
 560         return ERR_PTR(-ENOMEM);
 561 }
 562
 563 void zfcp_adapter_unregister(struct zfcp_adapter *adapter)
 564 {
 565         struct ccw_device *cdev = adapter->ccw_device;
 566
 567         cancel_work_sync(&adapter->scan_work);
 568         cancel_work_sync(&adapter->stat_work);
 569         zfcp_destroy_adapter_work_queue(adapter);
 570
 571         zfcp_fc_wka_ports_force_offline(adapter->gs);
 572         zfcp_adapter_scsi_unregister(adapter);
 573         sysfs_remove_group(&cdev->dev.kobj, &zfcp_sysfs_adapter_attrs);
 574
 575         zfcp_erp_thread_kill(adapter);
 576         zfcp_dbf_adapter_unregister(adapter->dbf);
 577         zfcp_qdio_destroy(adapter->qdio);
 578
 579         zfcp_ccw_adapter_put(adapter); /* final put to release */
 580 }
 581
 582 /**
 583  * zfcp_adapter_release - remove the adapter from the resource list
 584  * @ref: pointer to struct kref
 585  * locks:       adapter list write lock is assumed to be held by caller
 586  */
 587 void zfcp_adapter_release(struct kref *ref)
 588 {
 589         struct zfcp_adapter *adapter = container_of(ref, struct zfcp_adapter,
 590                                                     ref);
 591         struct ccw_device *cdev = adapter->ccw_device;
 592
 593         dev_set_drvdata(&adapter->ccw_device->dev, NULL);
 594         zfcp_fc_gs_destroy(adapter);
 595         zfcp_free_low_mem_buffers(adapter);
 596         kfree(adapter->req_list);
 597         kfree(adapter->fc_stats);
 598         kfree(adapter->stats_reset_data);
 599         kfree(adapter);
 600         put_device(&cdev->dev);
 601 }
 602
 603 /**
 604  * zfcp_device_unregister - remove port, unit from system
 605  * @dev: reference to device which is to be removed
 606  * @grp: related reference to attribute group
 607  *
 608  * Helper function to unregister port, unit from system
 609  */
 610 void zfcp_device_unregister(struct device *dev,
 611                             const struct attribute_group *grp)
 612 {
 613         sysfs_remove_group(&dev->kobj, grp);
 614         device_unregister(dev);
 615 }
 616
 617 static void zfcp_port_release(struct device *dev)
 618 {
 619         struct zfcp_port *port = container_of(dev, struct zfcp_port, dev);
 620
 621         zfcp_ccw_adapter_put(port->adapter);
 622         kfree(port);
 623 }
 624
 625 /**
 626  * zfcp_port_enqueue - enqueue port to port list of adapter
 627  * @adapter: adapter where remote port is added
 628  * @wwpn: WWPN of the remote port to be enqueued
 629  * @status: initial status for the port
 630  * @d_id: destination id of the remote port to be enqueued
 631  * Returns: pointer to enqueued port on success, ERR_PTR on error
 632  *
 633  * All port internal structures are set up and the sysfs entry is generated.
 634  * d_id is used to enqueue ports with a well known address like the Directory
 635  * Service for nameserver lookup.
 636  */
 637 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 638                                      u32 status, u32 d_id)
 639 {
 640         struct zfcp_port *port;
 641         int retval = -ENOMEM;
 642
 643         kref_get(&adapter->ref);
 644
 645         port = zfcp_get_port_by_wwpn(adapter, wwpn);
 646         if (port) {
 647                 put_device(&port->dev);
 648                 retval = -EEXIST;
 649                 goto err_out;
 650         }
 651
 652         port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
 653         if (!port)
 654                 goto err_out;
 655
 656         rwlock_init(&port->unit_list_lock);
 657         INIT_LIST_HEAD(&port->unit_list);
 658
 659         INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
 660         INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
 661         INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
 662
 663         port->adapter = adapter;
 664         port->d_id = d_id;
 665         port->wwpn = wwpn;
 666         port->rport_task = RPORT_NONE;
 667         port->dev.parent = &adapter->ccw_device->dev;
 668         port->dev.release = zfcp_port_release;
 669
 670         if (dev_set_name(&port->dev, "0x%016llx", (unsigned long long)wwpn)) {
 671                 kfree(port);
 672                 goto err_out;
 673         }
 674         retval = -EINVAL;
 675
 676         if (device_register(&port->dev)) {
 677                 put_device(&port->dev);
 678                 goto err_out;
 679         }
 680
 681         if (sysfs_create_group(&port->dev.kobj,
 682                                &zfcp_sysfs_port_attrs))
 683                 goto err_out_put;
 684
 685         write_lock_irq(&adapter->port_list_lock);
 686         list_add_tail(&port->list, &adapter->port_list);
 687         write_unlock_irq(&adapter->port_list_lock);
 688
 689         atomic_set_mask(status | ZFCP_STATUS_COMMON_RUNNING, &port->status);
 690
 691         return port;
 692
 693 err_out_put:
 694         device_unregister(&port->dev);
 695 err_out:
 696         zfcp_ccw_adapter_put(adapter);
 697         return ERR_PTR(retval);
 698 }
 699
 700 /**
 701  * zfcp_sg_free_table - free memory used by scatterlists
 702  * @sg: pointer to scatterlist
 703  * @count: number of scatterlist which are to be free'ed
 704  * the scatterlist are expected to reference pages always
 705  */
 706 void zfcp_sg_free_table(struct scatterlist *sg, int count)
 707 {
 708         int i;
 709
 710         for (i = 0; i < count; i++, sg++)
 711                 if (sg)
 712                         free_page((unsigned long) sg_virt(sg));
 713                 else
 714                         break;
 715 }
 716
 717 /**
 718  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
 719  * @sg: pointer to struct scatterlist
 720  * @count: number of scatterlists which should be assigned with buffers
 721  * of size page
 722  *
 723  * Returns: 0 on success, -ENOMEM otherwise
 724  */
 725 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
 726 {
 727         void *addr;
 728         int i;
 729
 730         sg_init_table(sg, count);
 731         for (i = 0; i < count; i++, sg++) {
 732                 addr = (void *) get_zeroed_page(GFP_KERNEL);
 733                 if (!addr) {
 734                         zfcp_sg_free_table(sg, i);
 735                         return -ENOMEM;
 736                 }
 737                 sg_set_buf(sg, addr, PAGE_SIZE);
 738         }
 739         return 0;
 740 }