path: root/drivers/s390/scsi/zfcp_fc.c

/*
 * zfcp device driver
 *
 * Fibre Channel related functions for the zfcp device driver.
 *
 * Copyright IBM Corp. 2008, 2010
 */

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

#include <linux/types.h>
#include <linux/slab.h>
#include <linux/utsname.h>
#include <scsi/fc/fc_els.h>
#include <scsi/libfc.h>
#include "zfcp_ext.h"
#include "zfcp_fc.h"

struct kmem_cache *zfcp_fc_req_cache;

static u32 zfcp_fc_rscn_range_mask[] = {
	[ELS_ADDR_FMT_PORT]		= 0xFFFFFF,
	[ELS_ADDR_FMT_AREA]		= 0xFFFF00,
	[ELS_ADDR_FMT_DOM]		= 0xFF0000,
	[ELS_ADDR_FMT_FAB]		= 0x000000,
};

static bool no_auto_port_rescan;
module_param_named(no_auto_port_rescan, no_auto_port_rescan, bool, 0600);
MODULE_PARM_DESC(no_auto_port_rescan,
		 "no automatic port_rescan (default off)");

void zfcp_fc_conditional_port_scan(struct zfcp_adapter *adapter)
{
	if (no_auto_port_rescan)
		return;

	queue_work(adapter->work_queue, &adapter->scan_work);
}

void zfcp_fc_inverse_conditional_port_scan(struct zfcp_adapter *adapter)
{
	if (!no_auto_port_rescan)
		return;

	queue_work(adapter->work_queue, &adapter->scan_work);
}

/**
 * zfcp_fc_post_event - post event to userspace via fc_transport
 * @work: work struct with enqueued events
 */
void zfcp_fc_post_event(struct work_struct *work)
{
	struct zfcp_fc_event *event = NULL, *tmp = NULL;
	LIST_HEAD(tmp_lh);
	struct zfcp_fc_events *events = container_of(work,
					struct zfcp_fc_events, work);
	struct zfcp_adapter *adapter = container_of(events, struct zfcp_adapter,
						events);

	spin_lock_bh(&events->list_lock);
	list_splice_init(&events->list, &tmp_lh);
	spin_unlock_bh(&events->list_lock);

	list_for_each_entry_safe(event, tmp, &tmp_lh, list) {
		fc_host_post_event(adapter->scsi_host, fc_get_event_number(),
				event->code, event->data);
		list_del(&event->list);
		kfree(event);
	}

}

/**
 * zfcp_fc_enqueue_event - safely enqueue FC HBA API event from irq context
 * @adapter: The adapter where to enqueue the event
 * @event_code: The event code (as defined in fc_host_event_code in
 *		scsi_transport_fc.h)
 * @event_data: The event data (e.g. n_port page in case of els)
 */
void zfcp_fc_enqueue_event(struct zfcp_adapter *adapter,
			enum fc_host_event_code event_code, u32 event_data)
{
	struct zfcp_fc_event *event;

	event = kmalloc(sizeof(struct zfcp_fc_event), GFP_ATOMIC);
	if (!event)
		return;

	event->code = event_code;
	event->data = event_data;

	spin_lock(&adapter->events.list_lock);
	list_add_tail(&event->list, &adapter->events.list);
	spin_unlock(&adapter->events.list_lock);

	queue_work(adapter->work_queue, &adapter->events.work);
}

static int zfcp_fc_wka_port_get(struct zfcp_fc_wka_port *wka_port)
{
	if (mutex_lock_interruptible(&wka_port->mutex))
		return -ERESTARTSYS;

	if (wka_port->status == ZFCP_FC_WKA_PORT_OFFLINE ||
	    wka_port->status == ZFCP_FC_WKA_PORT_CLOSING) {
		wka_port->status = ZFCP_FC_WKA_PORT_OPENING;
		if (zfcp_fsf_open_wka_port(wka_port))
			wka_port->status = ZFCP_FC_WKA_PORT_OFFLINE;
	}

	mutex_unlock(&wka_port->mutex);

	wait_event(wka_port->completion_wq,
		   wka_port->status == ZFCP_FC_WKA_PORT_ONLINE ||
		   wka_port->status == ZFCP_FC_WKA_PORT_OFFLINE);

	if (wka_port->status == ZFCP_FC_WKA_PORT_ONLINE) {
		atomic_inc(&wka_port->refcount);
		return 0;
	}
	return -EIO;
}

static void zfcp_fc_wka_port_offline(struct work_struct *work)
{
	struct delayed_work *dw = to_delayed_work(work);
	struct zfcp_fc_wka_port *wka_port =
			container_of(dw, struct zfcp_fc_wka_port, work);

	mutex_lock(&wka_port->mutex);
	if ((atomic_read(&wka_port->refcount) != 0) ||
	    (wka_port->status != ZFCP_FC_WKA_PORT_ONLINE))
		goto out;

	wka_port->status = ZFCP_FC_WKA_PORT_CLOSING;
	if (zfcp_fsf_close_wka_port(wka_port)) {
		wka_port->status = ZFCP_FC_WKA_PORT_OFFLINE;
		wake_up(&wka_port->completion_wq);
	}
out:
	mutex_unlock(&wka_port->mutex);
}

static void zfcp_fc_wka_port_put(struct zfcp_fc_wka_port *wka_port)
{
	if (atomic_dec_return(&wka_port->refcount) != 0)
		return;
	/* wait 10 milliseconds, other reqs might pop in */
	schedule_delayed_work(&wka_port->work, HZ / 100);
}

static void zfcp_fc_wka_port_init(struct zfcp_fc_wka_port *wka_port, u32 d_id,
				  struct