https://github.com/torvalds/linux
Tip revision: 6efb943b8616ec53a5e444193dccf1af9ad627b5 authored by Linus Torvalds on 09 May 2021, 21:17:44 UTC
Linux 5.13-rc1
Linux 5.13-rc1
Tip revision: 6efb943
zfcp_ccw.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,
};