Quelle  zfcp_ccw.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/*
 * zfcp device driver
 *
 * Registration and callback for the s390 common I/O layer.
 *
 * Copyright IBM Corp. 2002, 2010
 */

#define KMSG_COMPONENT "zfcp"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/module.h>
#include "zfcp_ext.h"
#include "zfcp_reqlist.h"

#define ZFCP_MODEL_PRIV 0x4

static DEFINE_SPINLOCK(zfcp_ccw_adapter_ref_lock);

struct zfcp_adapter *zfcp_ccw_adapter_by_cdev(struct ccw_device *cdev)
{
 struct zfcp_adapter *adapter;
 unsigned long flags;

 spin_lock_irqsave(&zfcp_ccw_adapter_ref_lock, flags);
 adapter = dev_get_drvdata(&cdev->dev);
 if (adapter)
  kref_get(&adapter->ref);
 spin_unlock_irqrestore(&zfcp_ccw_adapter_ref_lock, flags);
 return adapter;
}

void zfcp_ccw_adapter_put(struct zfcp_adapter *adapter)
{
 unsigned long flags;

 spin_lock_irqsave(&zfcp_ccw_adapter_ref_lock, flags);
 kref_put(&adapter->ref, zfcp_adapter_release);
 spin_unlock_irqrestore(&zfcp_ccw_adapter_ref_lock, flags);
}

/**
 * zfcp_ccw_activate - activate adapter and wait for it to finish
 * @cdev: pointer to belonging ccw device
 * @clear: Status flags to clear.
 * @tag: s390dbf trace record tag
 */
static int zfcp_ccw_activate(struct ccw_device *cdev, int clear, char *tag)
{
 struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);

 if (!adapter)
  return 0;

 zfcp_erp_clear_adapter_status(adapter, clear);
 zfcp_erp_set_adapter_status(adapter, ZFCP_STATUS_COMMON_RUNNING);
 zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
    tag);

 /*
 * We want to scan ports here, with some random backoff and without
 * rate limit. Recovery has already scheduled a port scan for us,
 * but with both random delay and rate limit. Nevertheless we get
 * what we want here by flushing the scheduled work after sleeping
 * an equivalent random time.
 * Let the port scan random delay elapse first. If recovery finishes
 * up to that point in time, that would be perfect for both recovery
 * and port scan. If not, i.e. recovery takes ages, there was no
 * point in waiting a random delay on top of the time consumed by
 * recovery.
 */
 msleep(zfcp_fc_port_scan_backoff());
 zfcp_erp_wait(adapter);
 flush_delayed_work(&adapter->scan_work);

 zfcp_ccw_adapter_put(adapter);

 return 0;
}

static struct ccw_device_id zfcp_ccw_device_id[] = {
 { CCW_DEVICE_DEVTYPE(0x1731, 0x3, 0x1732, 0x3) },
 { CCW_DEVICE_DEVTYPE(0x1731, 0x3, 0x1732, ZFCP_MODEL_PRIV) },
 {},
};
MODULE_DEVICE_TABLE(ccw, zfcp_ccw_device_id);

/**
 * zfcp_ccw_probe - probe function of zfcp driver
 * @cdev: pointer to belonging ccw device
 *
 * This function gets called by the common i/o layer for each FCP
 * device found on the current system. This is only a stub to make cio
 * work: To only allocate adapter resources for devices actually used,
 * the allocation is deferred to the first call to ccw_set_online.
 */
static int zfcp_ccw_probe(struct ccw_device *cdev)
{
 return 0;
}

/**
 * zfcp_ccw_remove - remove function of zfcp driver
 * @cdev: pointer to belonging ccw device
 *
 * This function gets called by the common i/o layer and removes an adapter
 * from the system. Task of this function is to get rid of all units and
 * ports that belong to this adapter. And in addition all resources of this
 * adapter will be freed too.
 */
static void zfcp_ccw_remove(struct ccw_device *cdev)
{
 struct zfcp_adapter *adapter;
 struct zfcp_port *port, *p;
 struct zfcp_unit *unit, *u;
 LIST_HEAD(unit_remove_lh);
 LIST_HEAD(port_remove_lh);

 ccw_device_set_offline(cdev);

 adapter = zfcp_ccw_adapter_by_cdev(cdev);
 if (!adapter)
  return;

 write_lock_irq(&adapter->port_list_lock);
 list_for_each_entry(port, &adapter->port_list, list) {
  write_lock(&port->unit_list_lock);
  list_splice_init(&port->unit_list, &unit_remove_lh);
  write_unlock(&port->unit_list_lock);
 }
 list_splice_init(&adapter->port_list, &port_remove_lh);
 write_unlock_irq(&adapter->port_list_lock);
 zfcp_ccw_adapter_put(adapter); /* put from zfcp_ccw_adapter_by_cdev */

 list_for_each_entry_safe(unit, u, &unit_remove_lh, list)
  device_unregister(&unit->dev);

 list_for_each_entry_safe(port, p, &port_remove_lh, list)
  device_unregister(&port->dev);

 zfcp_adapter_unregister(adapter);
}

/**
 * zfcp_ccw_set_online - set_online function of zfcp driver
 * @cdev: pointer to belonging ccw device
 *
 * This function gets called by the common i/o layer and sets an
 * adapter into state online.  The first call will allocate all
 * adapter resources that will be retained until the device is removed
 * via zfcp_ccw_remove.
 *
 * Setting an fcp device online means that it will be registered with
 * the SCSI stack, that the QDIO queues will be set up and that the
 * adapter will be opened.
 */
static int zfcp_ccw_set_online(struct ccw_device *cdev)
{
 struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);

 if (!adapter) {
  adapter = zfcp_adapter_enqueue(cdev);

  if (IS_ERR(adapter)) {
   dev_err(&cdev->dev,
    "Setting up data structures for the "
    "FCP adapter failed\n");
   return PTR_ERR(adapter);
  }
  kref_get(&adapter->ref);
 }

 /* initialize request counter */
 BUG_ON(!zfcp_reqlist_isempty(adapter->req_list));
 adapter->req_no = 0;

 zfcp_ccw_activate(cdev, 0, "ccsonl1");

 /*
 * We want to scan ports here, always, with some random delay and
 * without rate limit - basically what zfcp_ccw_activate() has
 * achieved for us. Not quite! That port scan depended on
 * !no_auto_port_rescan. So let's cover the no_auto_port_rescan
 * case here to make sure a port scan is done unconditionally.
 * Since zfcp_ccw_activate() has waited the desired random time,
 * we can immediately schedule and flush a port scan for the
 * remaining cases.
 */
 zfcp_fc_inverse_conditional_port_scan(adapter);
 flush_delayed_work(&adapter->scan_work);
 zfcp_ccw_adapter_put(adapter);
 return 0;
}

/**
 * zfcp_ccw_set_offline - set_offline function of zfcp driver
 * @cdev: pointer to belonging ccw device
 *
 * This function gets called by the common i/o layer and sets an adapter
 * into state offline.
 */
static int zfcp_ccw_set_offline(struct ccw_device *cdev)
{
 struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);

 if (!adapter)
  return 0;

 zfcp_erp_set_adapter_status(adapter, 0);
 zfcp_erp_adapter_shutdown(adapter, 0, "ccsoff1");
 zfcp_erp_wait(adapter);

 zfcp_ccw_adapter_put(adapter);
 return 0;
}

/**
 * zfcp_ccw_notify - ccw notify function
 * @cdev: pointer to belonging ccw device
 * @event: indicates if adapter was detached or attached
 *
 * This function gets called by the common i/o layer if an adapter has gone
 * or reappeared.
 */
static int zfcp_ccw_notify(struct ccw_device *cdev, int event)
{
 struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);

 if (!adapter)
  return 1;

 switch (event) {
 case CIO_GONE:
  dev_warn(&cdev->dev, "The FCP device has been detached\n");
  zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti1");
  break;
 case CIO_NO_PATH:
  dev_warn(&cdev->dev,
    "The CHPID for the FCP device is offline\n");
  zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti2");
  break;
 case CIO_OPER:
  dev_info(&cdev->dev, "The FCP device is operational again\n");
  zfcp_erp_set_adapter_status(adapter,
         ZFCP_STATUS_COMMON_RUNNING);
  zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
     "ccnoti4");
  break;
 case CIO_BOXED:
  dev_warn(&cdev->dev, "The FCP device did not respond within "
         "the specified time\n");
  zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti5");
  break;
 }

 zfcp_ccw_adapter_put(adapter);
 return 1;
}

/**
 * zfcp_ccw_shutdown - handle shutdown from cio
 * @cdev: device for adapter to shutdown.
 */
static void zfcp_ccw_shutdown(struct ccw_device *cdev)
{
 struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);

 if (!adapter)
  return;

 zfcp_erp_adapter_shutdown(adapter, 0, "ccshut1");
 zfcp_erp_wait(adapter);
 zfcp_erp_thread_kill(adapter);

 zfcp_ccw_adapter_put(adapter);
}

struct ccw_driver zfcp_ccw_driver = {
 .driver = {
  .owner = THIS_MODULE,
  .name = "zfcp",
 },
 .ids         = zfcp_ccw_device_id,
 .probe       = zfcp_ccw_probe,
 .remove      = zfcp_ccw_remove,
 .set_online  = zfcp_ccw_set_online,
 .set_offline = zfcp_ccw_set_offline,
 .notify      = zfcp_ccw_notify,
 .shutdown    = zfcp_ccw_shutdown,
};