text: // SPDX-License-Identifier: GPL-2.0
  /*
   * zfcp device driver
   *
   * Module interface and handling of zfcp data structures.
   *
   * Copyright IBM Corp. 2002, 2013
   */
  
  /*
   * Driver authors:
   *            Martin Peschke (originator of the driver)
   *            Raimund Schroeder
   *            Aron Zeh
   *            Wolfgang Taphorn
   *            Stefan Bader
   *            Heiko Carstens (kernel 2.6 port of the driver)
   *            Andreas Herrmann
   *            Maxim Shchetynin
   *            Volker Sameske
   *            Ralph Wuerthner
   *            Michael Loehr
   *            Swen Schillig
   *            Christof Schmitt
   *            Martin Petermann
   *            Sven Schuetz
   *            Steffen Maier
   */
  
  #define KMSG_COMPONENT "zfcp"
  #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  
  #include <linux/seq_file.h>
  #include <linux/slab.h>
  #include <linux/module.h>
  #include "zfcp_ext.h"
  #include "zfcp_fc.h"
  #include "zfcp_reqlist.h"
  
  #define ZFCP_BUS_ID_SIZE	20
  
  MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
  MODULE_DESCRIPTION("FCP HBA driver");
  MODULE_LICENSE("GPL");
  
  static char *init_device;
  module_param_named(device, init_device, charp, 0400);
  MODULE_PARM_DESC(device, "specify initial device");
  
  static struct kmem_cache * __init zfcp_cache_hw_align(const char *name,
  						      unsigned long size)
  {
  	return kmem_cache_create(name, size, roundup_pow_of_two(size), 0, NULL);
  }
  
  static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
  {
  	struct ccw_device *cdev;
  	struct zfcp_adapter *adapter;
  	struct zfcp_port *port;
  
  	cdev = get_ccwdev_by_busid(&zfcp_ccw_driver, busid);
  	if (!cdev)
  		return;
  
  	if (ccw_device_set_online(cdev))
  		goto out_ccw_device;
  
  	adapter = zfcp_ccw_adapter_by_cdev(cdev);
  	if (!adapter)
  		goto out_ccw_device;
  
  	port = zfcp_get_port_by_wwpn(adapter, wwpn);
  	if (!port)
  		goto out_port;
  	flush_work(&port->rport_work);
  
  	zfcp_unit_add(port, lun);
  	put_device(&port->dev);
  
  out_port:
  	zfcp_ccw_adapter_put(adapter);
  out_ccw_device:
  	put_device(&cdev->dev);
  	return;
  }
  
  static void __init zfcp_init_device_setup(char *devstr)
  {
  	char *token;
  	char *str, *str_saved;
  	char busid[ZFCP_BUS_ID_SIZE];
  	u64 wwpn, lun;
  
  	/* duplicate devstr and keep the original for sysfs presentation*/
  	str_saved = kstrdup(devstr, GFP_KERNEL);
  	str = str_saved;
  	if (!str)
  		return;
  
  	token = strsep(&str, ",");
  	if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
  		goto err_out;
  	strlcpy(busid, token, ZFCP_BUS_ID_SIZE);
  
  	token = strsep(&str, ",");
  	if (!token || kstrtoull(token, 0, (unsigned long long *) &wwpn))
  		goto err_out;
  
  	token = strsep(&str, ",");
  	if (!token || kstrtoull(token, 0, (unsigned long long *) &lun))
  		goto err_out;
  
  	kfree(str_saved);
  	zfcp_init_device_configure(busid, wwpn, lun);
  	return;
  
  err_out:
  	kfree(str_saved);
  	pr_err("%s is not a valid SCSI device\n", devstr);
  }
  
  static int __init zfcp_module_init(void)
  {
  	int retval = -ENOMEM;
  
  	zfcp_fsf_qtcb_cache = zfcp_cache_hw_align("zfcp_fsf_qtcb",
  						  sizeof(struct fsf_qtcb));
  	if (!zfcp_fsf_qtcb_cache)
  		goto out_qtcb_cache;
  
  	zfcp_fc_req_cache = zfcp_cache_hw_align("zfcp_fc_req",
  						sizeof(struct zfcp_fc_req));
  	if (!zfcp_fc_req_cache)
  		goto out_fc_cache;
  
  	zfcp_scsi_transport_template =
  		fc_attach_transport(&zfcp_transport_functions);
  	if (!zfcp_scsi_transport_template)
  		goto out_transport;
  	scsi_transport_reserve_device(zfcp_scsi_transport_template,
  				      sizeof(struct zfcp_scsi_dev));
  
  	retval = ccw_driver_register(&zfcp_ccw_driver);
  	if (retval) {
  		pr_err("The zfcp device driver could not register with "
  		       "the common I/O layer\n");
  		goto out_ccw_register;
  	}
  
  	if (init_device)
  		zfcp_init_device_setup(init_device);
  	return 0;
  
  out_ccw_register:
  	fc_release_transport(zfcp_scsi_transport_template);
  out_transport:
  	kmem_cache_destroy(zfcp_fc_req_cache);
  out_fc_cache:
  	kmem_cache_destroy(zfcp_fsf_qtcb_cache);
  out_qtcb_cache:
  	return retval;
  }
  
  module_init(zfcp_module_init);
  
  static void __exit zfcp_module_exit(void)
  {
  	ccw_driver_unregister(&zfcp_ccw_driver);
  	fc_release_transport(zfcp_scsi_transport_template);
  	kmem_cache_destroy(zfcp_fc_req_cache);
  	kmem_cache_destroy(zfcp_fsf_qtcb_cache);
  }
  
  module_exit(zfcp_module_exit);
  
  /**
   * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
   * @adapter: pointer to adapter to search for port
   * @wwpn: wwpn to search for
   *
   * Returns: pointer to zfcp_port or NULL
   */
  struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
  					u64 wwpn)
  {
  	unsigned long flags;
  	struct zfcp_port *port;
  
  	read_lock_irqsave(&adapter->port_list_lock, flags);
  	list_for_each_entry(port, &adapter->port_list, list)
  		if (port->wwpn == wwpn) {
  			if (!get_device(&port->dev))
  				port = NULL;
  			read_unlock_irqrestore(&adapter->port_list_lock, flags);
  			return port;
  		}
  	read_unlock_irqrestore(&adapter->port_list_lock, flags);
  	return NULL;
  }
  
  static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
  {
  	adapter->pool.erp_req =
  		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
  	if (!adapter->pool.erp_req)
  		return -ENOMEM;
  
  	adapter->pool.gid_pn_req =
  		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
  	if (!adapter->pool.gid_pn_req)
  		return -ENOMEM;
  
  	adapter->pool.scsi_req =
  		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
  	if (!adapter->pool.scsi_req)
  		return -ENOMEM;
  
  	adapter->pool.scsi_abort =
  		mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
  	if (!adapter->pool.scsi_abort)
  		return -ENOMEM;
  
  	adapter->pool.status_read_req =
  		mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
  					    sizeof(struct zfcp_fsf_req));
  	if (!adapter->pool.status_read_req)
  		return -ENOMEM;
  
  	adapter->pool.qtcb_pool =
  		mempool_create_slab_pool(4, zfcp_fsf_qtcb_cache);
  	if (!adapter->pool.qtcb_pool)
  		return -ENOMEM;
  
  	BUILD_BUG_ON(sizeof(struct fsf_status_read_buffer) > PAGE_SIZE);
  	adapter->pool.sr_data =
  		mempool_create_page_pool(FSF_STATUS_READS_RECOM, 0);
  	if (!adapter->pool.sr_data)
  		return -ENOMEM;
  
  	adapter->pool.gid_pn =
  		mempool_create_slab_pool(1, zfcp_fc_req_cache);
  	if (!adapter->pool.gid_pn)
  		return -ENOMEM;
  
  	return 0;
  }
  
  static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
  {
  	if (adapter->pool.erp_req)
  		mempool_destroy(adapter->pool.erp_req);
  	if (adapter->pool.scsi_req)
  		mempool_destroy(adapter->pool.scsi_req);
  	if (adapter->pool.scsi_abort)
  		mempool_destroy(adapter->pool.scsi_abort);
  	if (adapter->pool.qtcb_pool)
  		mempool_destroy(adapter->pool.qtcb_pool);
  	if (adapter->pool.status_read_req)
  		mempool_destroy(adapter->pool.status_read_req);
  	if (adapter->pool.sr_data)
  		mempool_destroy(adapter->pool.sr_data);
  	if (adapter->pool.gid_pn)
  		mempool_destroy(adapter->pool.gid_pn);
  }
  
  /**
   * zfcp_status_read_refill - refill the long running status_read_requests
   * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
   *
   * Returns: 0 on success, 1 otherwise
   *
   * if there are 16 or more status_read requests missing an adapter_reopen
   * is triggered
   */
  int zfcp_status_read_refill(struct zfcp_adapter *adapter)
  {
  	while (atomic_add_unless(&adapter->stat_miss, -1, 0))
  		if (zfcp_fsf_status_read(adapter->qdio)) {
  			atomic_inc(&adapter->stat_miss); /* undo add -1 */
  			if (atomic_read(&adapter->stat_miss) >=
  			    adapter->stat_read_buf_num) {
  				zfcp_erp_adapter_reopen(adapter, 0, "axsref1");
  				return 1;
  			}
  			break;
  		}
  	return 0;
  }
  
  static void _zfcp_status_read_scheduler(struct work_struct *work)
  {
  	zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
  					     stat_work));
  }
  
  static void zfcp_print_sl(struct seq_file *m, struct service_level *sl)
  {
  	struct zfcp_adapter *adapter =
  		container_of(sl, struct zfcp_adapter, service_level);
  
  	seq_printf(m, "zfcp: %s microcode level %x\n",
  		   dev_name(&adapter->ccw_device->dev),
  		   adapter->fsf_lic_version);
  }
  
  static int zfcp_setup_adapter_work_queue(struct zfcp_adapter *adapter)
  {
  	char name[TASK_COMM_LEN];
  
  	snprintf(name, sizeof(name), "zfcp_q_%s",
  		 dev_name(&adapter->ccw_device->dev));
  	adapter->work_queue = alloc_ordered_workqueue(name, WQ_MEM_RECLAIM);
  
  	if (adapter->work_queue)
  		return 0;
  	return -ENOMEM;
  }
  
  static void zfcp_destroy_adapter_work_queue(struct zfcp_adapter *adapter)
  {
  	if (adapter->work_queue)
  		destroy_workqueue(adapter->work_queue);
  	adapter->work_queue = NULL;
  
  }
  
  /**
   * zfcp_adapter_enqueue - enqueue a new adapter to the list
   * @ccw_device: pointer to the struct cc_device
   *
   * Returns:	struct zfcp_adapter*
   * Enqueues an adapter at the end of the adapter list in the driver data.
   * All adapter internal structures are set up.
   * Proc-fs entries are also created.
   */
  struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
  {
  	struct zfcp_adapter *adapter;
  
  	if (!get_device(&ccw_device->dev))
  		return ERR_PTR(-ENODEV);
  
  	adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
  	if (!adapter) {
  		put_device(&ccw_device->dev);
  		return ERR_PTR(-ENOMEM);
  	}
  
  	kref_init(&adapter->ref);
  
  	ccw_device->handler = NULL;
  	adapter->ccw_device = ccw_device;
  
  	INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
  	INIT_DELAYED_WORK(&adapter->scan_work, zfcp_fc_scan_ports);
  	INIT_WORK(&adapter->ns_up_work, zfcp_fc_sym_name_update);
  
  	adapter->next_port_scan = jiffies;
  
  	adapter->erp_action.adapter = adapter;
  
  	if (zfcp_qdio_setup(adapter))
  		goto failed;
  
  	if (zfcp_allocate_low_mem_buffers(adapter))
  		goto failed;
  
  	adapter->req_list = zfcp_reqlist_alloc();
  	if (!adapter->req_list)
  		goto failed;
  
  	if (zfcp_dbf_adapter_register(adapter))
  		goto failed;
  
  	if (zfcp_setup_adapter_work_queue(adapter))
  		goto failed;
  
  	if (zfcp_fc_gs_setup(adapter))
  		goto failed;
  
  	rwlock_init(&adapter->port_list_lock);
  	INIT_LIST_HEAD(&adapter->port_list);
  
  	INIT_LIST_HEAD(&adapter->events.list);
  	INIT_WORK(&adapter->events.work, zfcp_fc_post_event);
  	spin_lock_init(&adapter->events.list_lock);
  
  	init_waitqueue_head(&adapter->erp_ready_wq);
  	init_waitqueue_head(&adapter->erp_done_wqh);
  
  	INIT_LIST_HEAD(&adapter->erp_ready_head);
  	INIT_LIST_HEAD(&adapter->erp_running_head);
  
  	rwlock_init(&adapter->erp_lock);
  	rwlock_init(&adapter->abort_lock);
  
  	if (zfcp_erp_thread_setup(adapter))
  		goto failed;
  
  	adapter->service_level.seq_print = zfcp_print_sl;
  
  	dev_set_drvdata(&ccw_device->dev, adapter);
  
  	if (sysfs_create_group(&ccw_device->dev.kobj,
  			       &zfcp_sysfs_adapter_attrs))
  		goto failed;
  
  	/* report size limit per scatter-gather segment */
  	adapter->dma_parms.max_segment_size = ZFCP_QDIO_SBALE_LEN;
  	adapter->ccw_device->dev.dma_parms = &adapter->dma_parms;
  
  	adapter->stat_read_buf_num = FSF_STATUS_READS_RECOM;
  
  	if (!zfcp_scsi_adapter_register(adapter))
  		return adapter;
  
  failed:
  	zfcp_adapter_unregister(adapter);
  	return ERR_PTR(-ENOMEM);
  }
  
  void zfcp_adapter_unregister(struct zfcp_adapter *adapter)
  {
  	struct ccw_device *cdev = adapter->ccw_device;
  
  	cancel_delayed_work_sync(&adapter->scan_work);
  	cancel_work_sync(&adapter->stat_work);
  	cancel_work_sync(&adapter->ns_up_work);
  	zfcp_destroy_adapter_work_queue(adapter);
  
  	zfcp_fc_wka_ports_force_offline(adapter->gs);
  	zfcp_scsi_adapter_unregister(adapter);
  	sysfs_remove_group(&cdev->dev.kobj, &zfcp_sysfs_adapter_attrs);
  
  	zfcp_erp_thread_kill(adapter);
  	zfcp_dbf_adapter_unregister(adapter);
  	zfcp_qdio_destroy(adapter->qdio);
  
  	zfcp_ccw_adapter_put(adapter); /* final put to release */
  }
  
  /**
   * zfcp_adapter_release - remove the adapter from the resource list
   * @ref: pointer to struct kref
   * locks:	adapter list write lock is assumed to be held by caller
   */
  void zfcp_adapter_release(struct kref *ref)
  {
  	struct zfcp_adapter *adapter = container_of(ref, struct zfcp_adapter,
  						    ref);
  	struct ccw_device *cdev = adapter->ccw_device;
  
  	dev_set_drvdata(&adapter->ccw_device->dev, NULL);
  	zfcp_fc_gs_destroy(adapter);
  	zfcp_free_low_mem_buffers(adapter);
  	kfree(adapter->req_list);
  	kfree(adapter->fc_stats);
  	kfree(adapter->stats_reset_data);
  	kfree(adapter);
  	put_device(&cdev->dev);
  }
  
  static void zfcp_port_release(struct device *dev)
  {
  	struct zfcp_port *port = container_of(dev, struct zfcp_port, dev);
  
  	zfcp_ccw_adapter_put(port->adapter);
  	kfree(port);
  }
  
  /**
   * zfcp_port_enqueue - enqueue port to port list of adapter
   * @adapter: adapter where remote port is added
   * @wwpn: WWPN of the remote port to be enqueued
   * @status: initial status for the port
   * @d_id: destination id of the remote port to be enqueued
   * Returns: pointer to enqueued port on success, ERR_PTR on error
   *
   * All port internal structures are set up and the sysfs entry is generated.
   * d_id is used to enqueue ports with a well known address like the Directory
   * Service for nameserver lookup.
   */
  struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
  				     u32 status, u32 d_id)
  {
  	struct zfcp_port *port;
  	int retval = -ENOMEM;
  
  	kref_get(&adapter->ref);
  
  	port = zfcp_get_port_by_wwpn(adapter, wwpn);
  	if (port) {
  		put_device(&port->dev);
  		retval = -EEXIST;
  		goto err_out;
  	}
  
  	port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
  	if (!port)
  		goto err_out;
  
  	rwlock_init(&port->unit_list_lock);
  	INIT_LIST_HEAD(&port->unit_list);
  	atomic_set(&port->units, 0);
  
  	INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
  	INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
  	INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
  
  	port->adapter = adapter;
  	port->d_id = d_id;
  	port->wwpn = wwpn;
  	port->rport_task = RPORT_NONE;
  	port->dev.parent = &adapter->ccw_device->dev;
  	port->dev.groups = zfcp_port_attr_groups;
  	port->dev.release = zfcp_port_release;
  
  	port->erp_action.adapter = adapter;
  	port->erp_action.port = port;
  
  	if (dev_set_name(&port->dev, "0x%016llx", (unsigned long long)wwpn)) {
  		kfree(port);
  		goto err_out;
  	}
  	retval = -EINVAL;
  
  	if (device_register(&port->dev)) {
  		put_device(&port->dev);
  		goto err_out;
  	}
  
  	write_lock_irq(&adapter->port_list_lock);
  	list_add_tail(&port->list, &adapter->port_list);
  	write_unlock_irq(&adapter->port_list_lock);
  
  	atomic_or(status | ZFCP_STATUS_COMMON_RUNNING, &port->status);
  
  	return port;
  
  err_out:
  	zfcp_ccw_adapter_put(adapter);
  	return ERR_PTR(retval);
  }
  
  /**
   * zfcp_sg_free_table - free memory used by scatterlists
   * @sg: pointer to scatterlist
   * @count: number of scatterlist which are to be free'ed
   * the scatterlist are expected to reference pages always
   */
  void zfcp_sg_free_table(struct scatterlist *sg, int count)
  {
  	int i;
  
  	for (i = 0; i < count; i++, sg++)
  		if (sg)
  			free_page((unsigned long) sg_virt(sg));
  		else
  			break;
  }
  
  /**
   * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
   * @sg: pointer to struct scatterlist
   * @count: number of scatterlists which should be assigned with buffers
   * of size page
   *
   * Returns: 0 on success, -ENOMEM otherwise
   */
  int zfcp_sg_setup_table(struct scatterlist *sg, int count)
  {
  	void *addr;
  	int i;
  
  	sg_init_table(sg, count);
  	for (i = 0; i < count; i++, sg++) {
  		addr = (void *) get_zeroed_page(GFP_KERNEL);
  		if (!addr) {
  			zfcp_sg_free_table(sg, i);
  			return -ENOMEM;
  		}
  		sg_set_buf(sg, addr, PAGE_SIZE);
  	}
  	return 0;
  }
  