staging: virthba driver to access shared SCSI hba

The virthba module provides access to a shared SCSI host bus adapter
and one or more disk devices, by proxying SCSI commands between the
guest and the service partition that owns the shared SCSI adapter,
using a channel between the guest and the service partition. The disks
that appear on the shared bus are defined by the s-Par configuration
and enforced by the service partition, while the guest driver handles
sending commands and handling responses. Each disk is shared as a
whole to a guest. Sharing the bus adapter in this way provides
resiliency; should the device encounter an error, only the service
partition is rebooted, and the device is reinitialized. This allows
guests to continue running and to recover from the error.

Signed-off-by: Ken Cox <jkc@redhat.com>
Cc: Ben Romer <sparmaintainer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/unisys/Kconfig

@@ -15,5 +15,6 @@ source "drivers/staging/unisys/visorchipset/Kconfig"
 source "drivers/staging/unisys/channels/Kconfig"
 source "drivers/staging/unisys/uislib/Kconfig"
 source "drivers/staging/unisys/virtpci/Kconfig"
+source "drivers/staging/unisys/virthba/Kconfig"
 
 endif # UNISYSSPAR

drivers/staging/unisys/Makefile

@@ -7,3 +7,4 @@ obj-$(CONFIG_UNISYS_VISORCHIPSET)	+= visorchipset/
 obj-$(CONFIG_UNISYS_CHANNELSTUB)	+= channels/
 obj-$(CONFIG_UNISYS_UISLIB)		+= uislib/
 obj-$(CONFIG_UNISYS_VIRTPCI)		+= virtpci/
+obj-$(CONFIG_UNISYS_VIRTHBA)		+= virthba/

drivers/staging/unisys/virthba/Kconfig

@@ -0,0 +1,10 @@
+#
+# Unisys virthba configuration
+#
+
+config UNISYS_VIRTHBA
+	tristate "Unisys virthba driver"
+	depends on UNISYSSPAR && UNISYS_VISORCHIPSET && UNISYS_CHANNELSTUB && UNISYS_UISLIB && UNISYS_VIRTPCI
+	---help---
+	If you say Y here, you will enable the Unisys virthba driver.
+

drivers/staging/unisys/virthba/Makefile

@@ -0,0 +1,16 @@
+#
+# Makefile for Unisys virthba
+#
+
+obj-$(CONFIG_UNISYS_VIRTHBA)	+= virthba.o
+
+ccflags-y += -Idrivers/staging/unisys/include
+ccflags-y += -Idrivers/staging/unisys/uislib
+ccflags-y += -Idrivers/staging/unisys/timskmod
+ccflags-y += -Idrivers/staging/unisys/visorchipset
+ccflags-y += -Idrivers/staging/unisys/virtpci
+ccflags-y += -Idrivers/staging/unisys/common-spar/include
+ccflags-y += -Idrivers/staging/unisys/common-spar/include/channels
+
+ccflags-y += -DCONFIG_SPAR_GUEST -DGUESTDRIVERBUILD -DNOAUTOVERSION
+

drivers/staging/unisys/virthba/virthba.c

@@ -0,0 +1,1813 @@
+/* virthba.c
+ *
+ * Copyright © 2010 - 2013 UNISYS CORPORATION
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ */
+
+#define EXPORT_SYMTAB
+
+/* if you want to turn on some debugging of write device data or read
+ * device data, define these two undefs.  You will probably want to
+ * customize the code which is here since it was written assuming
+ * reading and writing a specific data file df.64M.txt which is a
+ * 64Megabyte file created by Art Nilson using a scritp I wrote called
+ * cr_test_data.pl.  The data file consists of 256 byte lines of text
+ * which start with an 8 digit sequence number, a colon, and then
+ * letters after that */
+
+#undef DBGINF
+
+#include <linux/kernel.h>
+#ifdef CONFIG_MODVERSIONS
+#include <config/modversions.h>
+#endif
+
+#include "uniklog.h"
+#include "diagnostics/appos_subsystems.h"
+#include "uisutils.h"
+#include "uisqueue.h"
+#include "uisthread.h"
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <asm/param.h>
+#include <linux/proc_fs.h>
+#include <linux/types.h>
+
+#include "virthba.h"
+#include "virtpci.h"
+#include "visorchipset.h"
+#include "version.h"
+#include "guestlinuxdebug.h"
+/* this is shorter than using __FILE__ (full path name) in
+ * debug/info/error messages
+ */
+#define CURRENT_FILE_PC VIRT_HBA_PC_virthba_c
+#define __MYFILE__ "virthba.c"
+
+/* NOTE:  L1_CACHE_BYTES >=128 */
+#define DEVICE_ATTRIBUTE struct device_attribute
+
+/*****************************************************/
+/* Forward declarations                              */
+/*****************************************************/
+static int virthba_probe(struct virtpci_dev *dev,
+			 const struct pci_device_id *id);
+static void virthba_remove(struct virtpci_dev *dev);
+static int virthba_abort_handler(struct scsi_cmnd *scsicmd);
+static int virthba_bus_reset_handler(struct scsi_cmnd *scsicmd);
+static int virthba_device_reset_handler(struct scsi_cmnd *scsicmd);
+static int virthba_host_reset_handler(struct scsi_cmnd *scsicmd);
+static const char *virthba_get_info(struct Scsi_Host *shp);
+static int virthba_ioctl(struct scsi_device *dev, int cmd, void __user *arg);
+static int virthba_queue_command_lck(struct scsi_cmnd *scsicmd,
+				     void (*virthba_cmnd_done)(struct scsi_cmnd *));
+#ifdef DEF_SCSI_QCMD
+DEF_SCSI_QCMD(virthba_queue_command)
+#else
+#define virthba_queue_command virthba_queue_command_lck
+#endif
+static int virthba_slave_alloc(struct scsi_device *scsidev);
+static int virthba_slave_configure(struct scsi_device *scsidev);
+static void virthba_slave_destroy(struct scsi_device *scsidev);
+static int process_incoming_rsps(void *);
+static int virthba_serverup(struct virtpci_dev *virtpcidev);
+static int virthba_serverdown(struct virtpci_dev *virtpcidev, u32 state);
+static void doDiskAddRemove(struct work_struct *work);
+static void virthba_serverdown_complete(struct work_struct *work);
+
+static ssize_t info_proc_read(struct file *file, char __user *buf,
+			      size_t len, loff_t *offset);
+static ssize_t rqwu_proc_write(struct file *file, const char __user *buffer,
+			       size_t count, loff_t *ppos);
+static ssize_t enable_ints_read(struct file *file, char __user *buffer,
+				size_t count, loff_t *ppos);
+static ssize_t enable_ints_write(struct file *file, const char __user *buffer,
+				 size_t count, loff_t *ppos);
+
+/*****************************************************/
+/* Globals                                           */
+/*****************************************************/
+
+int rsltq_wait_usecs = 4000;	/* Default 4ms */
+static unsigned int MaxBuffLen;
+
+/* Module options */
+char *virthba_options = "NONE";
+
+static const struct pci_device_id virthba_id_table[] = {
+	{PCI_DEVICE(PCI_VENDOR_ID_UNISYS, PCI_DEVICE_ID_VIRTHBA)},
+	{0},
+};
+
+/* export virthba_id_table */
+MODULE_DEVICE_TABLE(pci, virthba_id_table);
+
+static struct workqueue_struct *virthba_serverdown_workqueue;
+
+static struct virtpci_driver virthba_driver = {
+	.name = "uisvirthba",
+	.version = VERSION,
+	.vertag = NULL,
+	.build_date = __DATE__,
+	.build_time = __TIME__,
+	.id_table = virthba_id_table,
+	.probe = virthba_probe,
+	.remove = virthba_remove,
+	.resume = virthba_serverup,
+	.suspend = virthba_serverdown
+};
+
+/* The Send and Recive Buffers of the IO Queue may both be full */
+#define MAX_PENDING_REQUESTS (MIN_NUMSIGNALS*2)
+#define INTERRUPT_VECTOR_MASK 0x3F
+
+struct scsipending {
+	char cmdtype;		/* Type of pointer that is being stored */
+	void *sent;		/* The Data being tracked */
+	/* struct scsi_cmnd *type for virthba_queue_command */
+	/* struct uiscmdrsp *type for management commands */
+};
+
+#define VIRTHBA_ERROR_COUNT 30
+#define IOS_ERROR_THRESHOLD 1000
+struct virtdisk_info {
+	U32 valid;
+	U32 channel, id, lun;	/* Disk Path */
+	atomic_t ios_threshold;
+	atomic_t error_count;
+	struct virtdisk_info *next;
+};
+/* Each Scsi_Host has a host_data area that contains this struct. */
+struct virthba_info {
+	struct Scsi_Host *scsihost;
+	struct virtpci_dev *virtpcidev;
+	struct list_head dev_info_list;
+	struct chaninfo chinfo;
+	struct InterruptInfo intr;	/* use recvInterrupt info to receive
+					   interrupts when IOs complete */
+	int interrupt_vector;
+	struct scsipending pending[MAX_PENDING_REQUESTS]; /* Tracks the requests
+							     that have been */
+	/* forwarded to the IOVM and haven't returned yet */
+	unsigned int nextinsert;	/* Start search for next pending
+					   free slot here */
+	spinlock_t privlock;
+	bool serverdown;
+	bool serverchangingstate;
+	unsigned long long acquire_failed_cnt;
+	unsigned long long interrupts_rcvd;
+	unsigned long long interrupts_notme;
+	unsigned long long interrupts_disabled;
+	struct work_struct serverdown_completion;
+	U64 *flags_addr;
+	atomic_t interrupt_rcvd;
+	wait_queue_head_t rsp_queue;
+	struct virtdisk_info head;
+};
+
+/* Work Data for DARWorkQ */
+struct diskaddremove {
+	U8 add;			/* 0-remove, 1-add */
+	struct Scsi_Host *shost; /* Scsi Host for this virthba instance */
+	U32 channel, id, lun;	/* Disk Path */
+	struct diskaddremove *next;
+};
+
+#define virtpci_dev_to_virthba_virthba_get_info(d) \
+	container_of(d, struct virthba_info, virtpcidev)
+
+static DEVICE_ATTRIBUTE *virthba_shost_attrs[];
+static struct scsi_host_template virthba_driver_template = {
+	.name = "Unisys Virtual HBA",
+	.proc_name = "uisvirthba",
+	.info = virthba_get_info,
+	.ioctl = virthba_ioctl,
+	.queuecommand = virthba_queue_command,
+	.eh_abort_handler = virthba_abort_handler,
+	.eh_device_reset_handler = virthba_device_reset_handler,
+	.eh_bus_reset_handler = virthba_bus_reset_handler,
+	.eh_host_reset_handler = virthba_host_reset_handler,
+	.shost_attrs = virthba_shost_attrs,
+
+#define VIRTHBA_MAX_CMNDS 128
+	.can_queue = VIRTHBA_MAX_CMNDS,
+	.sg_tablesize = 64,	/* largest number of address/length pairs */
+	.this_id = -1,
+	.slave_alloc = virthba_slave_alloc,
+	.slave_configure = virthba_slave_configure,
+	.slave_destroy = virthba_slave_destroy,
+	.use_clustering = ENABLE_CLUSTERING,
+};
+
+struct virthba_devices_open {
+	struct virthba_info *virthbainfo;
+};
+
+static const struct file_operations proc_info_fops = {
+	.read = info_proc_read,
+};
+
+static const struct file_operations proc_rqwu_fops = {
+	.write = rqwu_proc_write,
+};
+
+static const struct file_operations proc_enable_ints_fops = {
+	.read = enable_ints_read,
+	.write = enable_ints_write,
+};
+
+
+#define VIRTHBASOPENMAX 1
+/* array of open devices maintained by open() and close(); */
+static struct virthba_devices_open VirtHbasOpen[VIRTHBASOPENMAX];
+static struct proc_dir_entry *virthba_proc_dir;
+static struct proc_dir_entry *info_proc_entry;
+static struct proc_dir_entry *rqwaitus_proc_entry;
+static struct proc_dir_entry *enable_ints_proc_entry;
+#define INFO_PROC_ENTRY_FN "info"
+#define ENABLE_INTS_ENTRY_FN "enable_ints"
+#define RQWU_PROC_ENTRY_FN "rqwait_usecs"
+#define DIR_PROC_ENTRY "virthba"
+
+/*****************************************************/
+/* Local Functions				     */
+/*****************************************************/
+static int
+add_scsipending_entry(struct virthba_info *vhbainfo, char cmdtype, void *new)
+{
+	unsigned long flags;
+	int insert_location;
+
+	spin_lock_irqsave(&vhbainfo->privlock, flags);
+	insert_location = vhbainfo->nextinsert;
+	while (vhbainfo->pending[insert_location].sent != NULL) {
+		insert_location = (insert_location + 1) % MAX_PENDING_REQUESTS;
+		if (insert_location == (int) vhbainfo->nextinsert) {
+			LOGERR("Queue should be full. insert_location<<%d>>  Unable to find open slot for pending commands.\n",
+			     insert_location);
+			spin_unlock_irqrestore(&vhbainfo->privlock, flags);
+			return -1;
+		}
+	}
+
+	vhbainfo->pending[insert_location].cmdtype = cmdtype;
+	vhbainfo->pending[insert_location].sent = new;
+	vhbainfo->nextinsert = (insert_location + 1) % MAX_PENDING_REQUESTS;
+	spin_unlock_irqrestore(&vhbainfo->privlock, flags);
+
+	return insert_location;
+}
+
+static unsigned int
+add_scsipending_entry_with_wait(struct virthba_info *vhbainfo, char cmdtype,
+				void *new)
+{
+	int insert_location = add_scsipending_entry(vhbainfo, cmdtype, new);
+
+	while (insert_location == -1) {
+		LOGERR("Failed to find empty queue slot.  Waiting to try again\n");
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(msecs_to_jiffies(10));
+		insert_location = add_scsipending_entry(vhbainfo, cmdtype, new);
+	}
+
+	return (unsigned int) insert_location;
+}
+
+static void *
+del_scsipending_entry(struct virthba_info *vhbainfo, uintptr_t del)
+{
+	unsigned long flags;
+	void *sent = NULL;
+
+	if (del >= MAX_PENDING_REQUESTS) {
+		LOGERR("Invalid queue position <<%lu>> given to delete. MAX_PENDING_REQUESTS <<%d>>\n",
+		     (unsigned long) del, MAX_PENDING_REQUESTS);
+	} else {
+		spin_lock_irqsave(&vhbainfo->privlock, flags);
+
+		if (vhbainfo->pending[del].sent == NULL)
+			LOGERR("Deleting already cleared queue entry at <<%lu>>.\n",
+			     (unsigned long) del);
+
+		sent = vhbainfo->pending[del].sent;
+
+		vhbainfo->pending[del].cmdtype = 0;
+		vhbainfo->pending[del].sent = NULL;
+		spin_unlock_irqrestore(&vhbainfo->privlock, flags);
+	}
+
+	return sent;
+}
+
+/* DARWorkQ (Disk Add/Remove) */
+static struct work_struct DARWorkQ;
+struct diskaddremove *DARWorkQHead = NULL;
+spinlock_t DARWorkQLock;
+unsigned short DARWorkQSched = 0;
+#define QUEUE_DISKADDREMOVE(dar) { \
+	spin_lock_irqsave(&DARWorkQLock, flags); \
+	if (!DARWorkQHead) { \
+		DARWorkQHead = dar; \
+		dar->next = NULL; \
+	} \
+	else { \
+		dar->next = DARWorkQHead; \
+		DARWorkQHead = dar; \
+	} \
+	if (!DARWorkQSched) { \
+		schedule_work(&DARWorkQ); \
+		DARWorkQSched = 1; \
+	} \
+	spin_unlock_irqrestore(&DARWorkQLock, flags); \
+}
+
+static inline void
+SendDiskAddRemove(struct diskaddremove *dar)
+{
+	struct scsi_device *sdev;
+	int error;
+
+	sdev = scsi_device_lookup(dar->shost, dar->channel, dar->id, dar->lun);
+	if (sdev) {
+		if (!(dar->add))
+			scsi_remove_device(sdev);
+	} else if (dar->add) {
+		error =
+		    scsi_add_device(dar->shost, dar->channel, dar->id,
+				    dar->lun);
+		if (error)
+			LOGERR("Failed scsi_add_device: host_no=%d[chan=%d:id=%d:lun=%d]\n",
+			     dar->shost->host_no, dar->channel, dar->id,
+			     dar->lun);
+	} else
+		LOGERR("Failed scsi_device_lookup:[chan=%d:id=%d:lun=%d]\n",
+		       dar->channel, dar->id, dar->lun);
+	kfree(dar);
+}
+
+/*****************************************************/
+/* DARWorkQ Handler Thread                           */
+/*****************************************************/
+static void
+doDiskAddRemove(struct work_struct *work)
+{
+	struct diskaddremove *dar;
+	struct diskaddremove *tmphead;
+	int i = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&DARWorkQLock, flags);
+	tmphead = DARWorkQHead;
+	DARWorkQHead = NULL;
+	DARWorkQSched = 0;
+	spin_unlock_irqrestore(&DARWorkQLock, flags);
+	while (tmphead) {
+		dar = tmphead;
+		tmphead = dar->next;
+		SendDiskAddRemove(dar);
+		i++;
+	}
+}
+
+/*****************************************************/
+/* Routine to add entry to DARWorkQ                  */
+/*****************************************************/
+static void
+process_disk_notify(struct Scsi_Host *shost, struct uiscmdrsp *cmdrsp)
+{
+	struct diskaddremove *dar;
+	unsigned long flags;
+
+	dar = kmalloc(sizeof(struct diskaddremove), GFP_ATOMIC);
+	if (dar) {
+		memset(dar, 0, sizeof(struct diskaddremove));
+		dar->add = cmdrsp->disknotify.add;
+		dar->shost = shost;
+		dar->channel = cmdrsp->disknotify.channel;
+		dar->id = cmdrsp->disknotify.id;
+		dar->lun = cmdrsp->disknotify.lun;
+		QUEUE_DISKADDREMOVE(dar);
+	} else {
+		LOGERR("kmalloc failed for dar. host_no=%d[chan=%d:id=%d:lun=%d]\n",
+		     shost->host_no, cmdrsp->disknotify.channel,
+		     cmdrsp->disknotify.id, cmdrsp->disknotify.lun);
+	}
+}
+
+/*****************************************************/
+/* Probe Remove Functions                            */
+/*****************************************************/
+irqreturn_t
+virthba_ISR(int irq, void *dev_id)
+{
+	struct virthba_info *virthbainfo = (struct virthba_info *) dev_id;
+	pCHANNEL_HEADER pChannelHeader;
+	pSIGNAL_QUEUE_HEADER pqhdr;
+	U64 mask;
+	unsigned long long rc1;
+
+	if (virthbainfo == NULL)
+		return IRQ_NONE;
+	virthbainfo->interrupts_rcvd++;
+	pChannelHeader = virthbainfo->chinfo.queueinfo->chan;
+	if (((pChannelHeader->Features
+	      & ULTRA_IO_IOVM_IS_OK_WITH_DRIVER_DISABLING_INTS) != 0)
+	    && ((pChannelHeader->Features & ULTRA_IO_DRIVER_DISABLES_INTS) !=
+		0)) {
+		virthbainfo->interrupts_disabled++;
+		mask = ~ULTRA_CHANNEL_ENABLE_INTS;
+		rc1 = uisqueue_InterlockedAnd(virthbainfo->flags_addr, mask);
+	}
+	if (SignalQueueIsEmpty(pChannelHeader, IOCHAN_FROM_IOPART)) {
+		virthbainfo->interrupts_notme++;
+		return IRQ_NONE;
+	}
+	pqhdr = (pSIGNAL_QUEUE_HEADER) ((char *) pChannelHeader +
+					pChannelHeader->oChannelSpace) +
+					IOCHAN_FROM_IOPART;
+	pqhdr->NumInterruptsReceived++;
+	atomic_set(&virthbainfo->interrupt_rcvd, 1);
+	wake_up_interruptible(&virthbainfo->rsp_queue);
+	return IRQ_HANDLED;
+}
+
+static int
+virthba_probe(struct virtpci_dev *virtpcidev, const struct pci_device_id *id)
+{
+	int error;
+	struct Scsi_Host *scsihost;
+	struct virthba_info *virthbainfo;
+	int rsp;
+	int i;
+	irq_handler_t handler = virthba_ISR;
+	pCHANNEL_HEADER pChannelHeader;
+	pSIGNAL_QUEUE_HEADER pqhdr;
+	U64 mask;
+
+	LOGVER("entering virthba_probe...\n");
+	LOGVER("virtpcidev busNo<<%d>>devNo<<%d>>", virtpcidev->busNo,
+	       virtpcidev->deviceNo);
+
+	LOGINF("entering virthba_probe...\n");
+	LOGINF("virtpcidev busNo<<%d>>devNo<<%d>>", virtpcidev->busNo,
+	       virtpcidev->deviceNo);
+	POSTCODE_LINUX_2(VHBA_PROBE_ENTRY_PC, POSTCODE_SEVERITY_INFO);
+	/* call scsi_host_alloc to register a scsi host adapter
+	 * instance - this virthba that has just been created is an
+	 * instance of a scsi host adapter. This scsi_host_alloc
+	 * function allocates a new Scsi_Host struct & performs basic
+	 * initializatoin.  The host is not published to the scsi
+	 * midlayer until scsi_add_host is called.
+	 */
+	DBGINF("calling scsi_host_alloc.\n");
+
+	/* arg 2 passed in length of extra space we want allocated
+	 * with scsi_host struct for our own use scsi_host_alloc
+	 * assign host_no
+	 */
+	scsihost = scsi_host_alloc(&virthba_driver_template,
+				   sizeof(struct virthba_info));
+	if (scsihost == NULL)
+		return -ENODEV;
+
+	DBGINF("scsihost: 0x%p, scsihost->this_id: %d, host_no: %d.\n",
+	       scsihost, scsihost->this_id, scsihost->host_no);
+
+	scsihost->this_id = UIS_MAGIC_VHBA;
+	/* linux treats max-channel differently than max-id & max-lun.
+	 * In the latter cases, those two values result in 0 to max-1
+	 * (inclusive) being scanned. But in the case of channels, the
+	 * scan is 0 to max (inclusive); so we will subtract one from
+	 * the max-channel value.
+	 */
+	LOGINF("virtpcidev->scsi.max.max_channel=%u, max_id=%u, max_lun=%u, cmd_per_lun=%u, max_io_size=%u\n",
+	     (unsigned) virtpcidev->scsi.max.max_channel - 1,
+	     (unsigned) virtpcidev->scsi.max.max_id,
+	     (unsigned) virtpcidev->scsi.max.max_lun,
+	     (unsigned) virtpcidev->scsi.max.cmd_per_lun,
+	     (unsigned) virtpcidev->scsi.max.max_io_size);
+	scsihost->max_channel = (unsigned) virtpcidev->scsi.max.max_channel;
+	scsihost->max_id = (unsigned) virtpcidev->scsi.max.max_id;
+	scsihost->max_lun = (unsigned) virtpcidev->scsi.max.max_lun;
+	scsihost->cmd_per_lun = (unsigned) virtpcidev->scsi.max.cmd_per_lun;
+	scsihost->max_sectors =
+	    (unsigned short) (virtpcidev->scsi.max.max_io_size >> 9);
+	scsihost->sg_tablesize =
+	    (unsigned short) (virtpcidev->scsi.max.max_io_size / PAGE_SIZE);
+	if (scsihost->sg_tablesize > MAX_PHYS_INFO)
+		scsihost->sg_tablesize = MAX_PHYS_INFO;
+	LOGINF("scsihost->max_channel=%u, max_id=%u, max_lun=%u, cmd_per_lun=%u, max_sectors=%hu, sg_tablesize=%hu\n",
+	     scsihost->max_channel, scsihost->max_id, scsihost->max_lun,
+	     scsihost->cmd_per_lun, scsihost->max_sectors,
+	     scsihost->sg_tablesize);
+	LOGINF("scsihost->can_queue=%u, scsihost->cmd_per_lun=%u, max_sectors=%hu, sg_tablesize=%hu\n",
+	     scsihost->can_queue, scsihost->cmd_per_lun, scsihost->max_sectors,
+	     scsihost->sg_tablesize);
+
+	DBGINF("calling scsi_add_host\n");
+
+	/* this creates "host%d" in sysfs.  If 2nd argument is NULL,
+	 * then this generic /sys/devices/platform/host?  device is
+	 * created and /sys/scsi_host/host? ->
+	 * /sys/devices/platform/host?  If 2nd argument is not NULL,
+	 * then this generic /sys/devices/<path>/host? is created and
+	 * host? points to that device instead.
+	 */
+	error = scsi_add_host(scsihost, &virtpcidev->generic_dev);
+	if (error) {
+		LOGERR("scsi_add_host ****FAILED 0x%x  TBD - RECOVER\n", error);
+		POSTCODE_LINUX_2(VHBA_PROBE_FAILURE_PC, POSTCODE_SEVERITY_ERR);
+		/* decr refcount on scsihost which was incremented by
+		 * scsi_add_host so the scsi_host gets deleted
+		 */
+		scsi_host_put(scsihost);
+		return -ENODEV;
+	}
+
+	virthbainfo = (struct virthba_info *) scsihost->hostdata;
+	memset(virthbainfo, 0, sizeof(struct virthba_info));
+	for (i = 0; i < VIRTHBASOPENMAX; i++) {
+		if (VirtHbasOpen[i].virthbainfo == NULL) {
+			VirtHbasOpen[i].virthbainfo = virthbainfo;
+			break;
+		}
+	}
+	virthbainfo->interrupt_vector = -1;
+	virthbainfo->chinfo.queueinfo = &virtpcidev->queueinfo;
+	virthbainfo->virtpcidev = virtpcidev;
+	spin_lock_init(&virthbainfo->chinfo.insertlock);
+
+	DBGINF("generic_dev: 0x%p, queueinfo: 0x%p.\n",
+	       &virtpcidev->generic_dev, &virtpcidev->queueinfo);
+
+	init_waitqueue_head(&virthbainfo->rsp_queue);
+	spin_lock_init(&virthbainfo->privlock);
+	memset(&virthbainfo->pending, 0, sizeof(virthbainfo->pending));
+	virthbainfo->serverdown = false;
+	virthbainfo->serverchangingstate = false;
+
+	virthbainfo->intr = virtpcidev->intr;
+	/* save of host within virthba_info */
+	virthbainfo->scsihost = scsihost;
+
+	/* save of host within virtpci_dev */
+	virtpcidev->scsi.scsihost = scsihost;
+
+	/* Setup workqueue for serverdown messages */
+	INIT_WORK(&virthbainfo->serverdown_completion,
+		  virthba_serverdown_complete);
+
+	virthbainfo->chinfo.queueinfo->chan->Features |=
+	    ULTRA_IO_CHANNEL_IS_POLLING;
+	/* start thread that will receive scsicmnd responses */
+	DBGINF("starting rsp thread -- queueinfo: 0x%p, threadinfo: 0x%p.\n",
+	       virthbainfo->chinfo.queueinfo, &virthbainfo->chinfo.threadinfo);
+
+	pChannelHeader = virthbainfo->chinfo.queueinfo->chan;
+	pqhdr = (pSIGNAL_QUEUE_HEADER) ((char *) pChannelHeader +
+					pChannelHeader->oChannelSpace) +
+					IOCHAN_FROM_IOPART;
+	virthbainfo->flags_addr = &pqhdr->FeatureFlags;
+
+	if (!uisthread_start(&virthbainfo->chinfo.threadinfo,
+			     process_incoming_rsps,
+			     virthbainfo, "vhba_incoming")) {
+		LOGERR("uisthread_start rsp ****FAILED\n");
+		/* decr refcount on scsihost which was incremented by
+		 * scsi_add_host so the scsi_host gets deleted
+		 */
+		POSTCODE_LINUX_2(VHBA_PROBE_FAILURE_PC, POSTCODE_SEVERITY_ERR);
+		scsi_host_put(scsihost);
+		return -ENODEV;
+	}
+	LOGINF("sendInterruptHandle=0x%16llX",
+	       virthbainfo->intr.sendInterruptHandle);
+	LOGINF("recvInterruptHandle=0x%16llX",
+	       virthbainfo->intr.recvInterruptHandle);
+	LOGINF("recvInterruptVector=0x%8X",
+	       virthbainfo->intr.recvInterruptVector);
+	LOGINF("recvInterruptShared=0x%2X",
+	       virthbainfo->intr.recvInterruptShared);
+	LOGINF("scsihost.hostt->name=%s", scsihost->hostt->name);
+	virthbainfo->interrupt_vector =
+	    virthbainfo->intr.recvInterruptHandle & INTERRUPT_VECTOR_MASK;
+	rsp = request_irq(virthbainfo->interrupt_vector, handler, IRQF_SHARED,
+			  scsihost->hostt->name, virthbainfo);
+	if (rsp != 0) {
+		LOGERR("request_irq(%d) uislib_virthba_ISR request failed with rsp=%d\n",
+		       virthbainfo->interrupt_vector, rsp);
+		virthbainfo->interrupt_vector = -1;
+		POSTCODE_LINUX_2(VHBA_PROBE_FAILURE_PC, POSTCODE_SEVERITY_ERR);
+	} else {
+		U64 *Features_addr =
+		    &virthbainfo->chinfo.queueinfo->chan->Features;
+		LOGERR("request_irq(%d) uislib_virthba_ISR request succeeded\n",
+		       virthbainfo->interrupt_vector);
+		mask = ~(ULTRA_IO_CHANNEL_IS_POLLING |
+			 ULTRA_IO_DRIVER_DISABLES_INTS);
+		uisqueue_InterlockedAnd(Features_addr, mask);
+		mask = ULTRA_IO_DRIVER_ENABLES_INTS;
+		uisqueue_InterlockedOr(Features_addr, mask);
+		rsltq_wait_usecs = 4000000;
+	}
+
+	DBGINF("calling scsi_scan_host.\n");
+	scsi_scan_host(scsihost);
+	DBGINF("return from scsi_scan_host.\n");
+
+	LOGINF("virthba added scsihost:0x%p\n", scsihost);
+	POSTCODE_LINUX_2(VHBA_PROBE_EXIT_PC, POSTCODE_SEVERITY_INFO);
+	return 0;
+}
+
+static void
+virthba_remove(struct virtpci_dev *virtpcidev)
+{
+	struct virthba_info *virthbainfo;
+	struct Scsi_Host *scsihost =
+	    (struct Scsi_Host *) virtpcidev->scsi.scsihost;
+
+	LOGINF("virtpcidev busNo<<%d>>devNo<<%d>>", virtpcidev->busNo,
+	       virtpcidev->deviceNo);
+	virthbainfo = (struct virthba_info *) scsihost->hostdata;
+	if (virthbainfo->interrupt_vector != -1)
+		free_irq(virthbainfo->interrupt_vector, virthbainfo);
+	LOGINF("Removing virtpcidev: 0x%p, virthbainfo: 0x%p\n", virtpcidev,
+	       virthbainfo);
+
+	DBGINF("removing scsihost: 0x%p, scsihost->this_id: %d\n", scsihost,
+	       scsihost->this_id);
+	scsi_remove_host(scsihost);
+
+	DBGINF("stopping thread.\n");
+	uisthread_stop(&virthbainfo->chinfo.threadinfo);
+
+	DBGINF("calling scsi_host_put\n");
+
+	/* decr refcount on scsihost which was incremented by
+	 * scsi_add_host so the scsi_host gets deleted
+	 */
+	scsi_host_put(scsihost);
+	LOGINF("virthba removed scsi_host.\n");
+}
+
+static int
+forward_vdiskmgmt_command(VDISK_MGMT_TYPES vdiskcmdtype,
+			  struct Scsi_Host *scsihost,
+			  struct uisscsi_dest *vdest)
+{
+	struct uiscmdrsp *cmdrsp;
+	struct virthba_info *virthbainfo =
+	    (struct virthba_info *) scsihost->hostdata;
+	int notifyresult = 0xffff;
+	wait_queue_head_t notifyevent;
+
+	LOGINF("vDiskMgmt:%d %d:%d:%d\n", vdiskcmdtype,
+	       vdest->channel, vdest->id, vdest->lun);
+
+	if (virthbainfo->serverdown || virthbainfo->serverchangingstate) {
+		DBGINF("Server is down/changing state. Returning Failure.\n");
+		return FAILED;
+	}
+
+	ALLOC_CMDRSP(cmdrsp);
+	if (cmdrsp == NULL) {
+		LOGERR("kmalloc of cmdrsp failed.\n");
+		return FAILED;	/* reject */
+	}
+
+	init_waitqueue_head(&notifyevent);
+
+	/* issue VDISK_MGMT_CMD
+	 * set type to command - as opposed to task mgmt
+	 */
+	cmdrsp->cmdtype = CMD_VDISKMGMT_TYPE;
+	/* specify the event that has to be triggered when this cmd is
+	 * complete
+	 */
+	cmdrsp->vdiskmgmt.notify = (void *) &notifyevent;
+	cmdrsp->vdiskmgmt.notifyresult = (void *) &notifyresult;
+
+	/* save destination */
+	cmdrsp->vdiskmgmt.vdisktype = vdiskcmdtype;
+	cmdrsp->vdiskmgmt.vdest.channel = vdest->channel;
+	cmdrsp->vdiskmgmt.vdest.id = vdest->id;
+	cmdrsp->vdiskmgmt.vdest.lun = vdest->lun;
+	cmdrsp->vdiskmgmt.scsicmd =
+	    (void *) (uintptr_t)
+		add_scsipending_entry_with_wait(virthbainfo, CMD_VDISKMGMT_TYPE,
+						(void *) cmdrsp);
+
+	uisqueue_put_cmdrsp_with_lock_client(virthbainfo->chinfo.queueinfo,
+					     cmdrsp, IOCHAN_TO_IOPART,
+					     &virthbainfo->chinfo.insertlock,
+					     DONT_ISSUE_INTERRUPT, (U64) NULL,
+					     OK_TO_WAIT, "vhba");
+	LOGINF("VdiskMgmt waiting on event notifyevent=0x%p\n",
+	       cmdrsp->scsitaskmgmt.notify);
+	wait_event(notifyevent, notifyresult != 0xffff);
+	LOGINF("VdiskMgmt complete; result:%d\n", cmdrsp->vdiskmgmt.result);
+	kfree(cmdrsp);
+	return SUCCESS;
+}
+
+/*****************************************************/
+/* Scsi Host support functions                       */
+/*****************************************************/
+
+static int
+forward_taskmgmt_command(TASK_MGMT_TYPES tasktype, struct scsi_device *scsidev)
+{
+	struct uiscmdrsp *cmdrsp;
+	struct virthba_info *virthbainfo =
+	    (struct virthba_info *) scsidev->host->hostdata;
+	int notifyresult = 0xffff;
+	wait_queue_head_t notifyevent;
+
+	LOGINF("TaskMgmt:%d %d:%d:%d\n", tasktype,
+	       scsidev->channel, scsidev->id, scsidev->lun);
+
+	if (virthbainfo->serverdown || virthbainfo->serverchangingstate) {
+		DBGINF("Server is down/changing state. Returning Failure.\n");
+		return FAILED;
+	}
+
+	ALLOC_CMDRSP(cmdrsp);
+	if (cmdrsp == NULL) {
+		LOGERR("kmalloc of cmdrsp failed.\n");
+		return FAILED;	/* reject */
+	}
+
+	init_waitqueue_head(&notifyevent);
+
+	/* issue TASK_MGMT_ABORT_TASK */
+	/* set type to command - as opposed to task mgmt */
+	cmdrsp->cmdtype = CMD_SCSITASKMGMT_TYPE;
+	/* specify the event that has to be triggered when this */
+	/* cmd is complete */
+	cmdrsp->scsitaskmgmt.notify = (void *) &notifyevent;
+	cmdrsp->scsitaskmgmt.notifyresult = (void *) &notifyresult;
+
+	/* save destination */
+	cmdrsp->scsitaskmgmt.tasktype = tasktype;
+	cmdrsp->scsitaskmgmt.vdest.channel = scsidev->channel;
+	cmdrsp->scsitaskmgmt.vdest.id = scsidev->id;
+	cmdrsp->scsitaskmgmt.vdest.lun = scsidev->lun;
+	cmdrsp->scsitaskmgmt.scsicmd =
+	    (void *) (uintptr_t)
+		add_scsipending_entry_with_wait(virthbainfo,
+						CMD_SCSITASKMGMT_TYPE,
+						(void *) cmdrsp);
+
+	uisqueue_put_cmdrsp_with_lock_client(virthbainfo->chinfo.queueinfo,
+					     cmdrsp, IOCHAN_TO_IOPART,
+					     &virthbainfo->chinfo.insertlock,
+					     DONT_ISSUE_INTERRUPT, (U64) NULL,
+					     OK_TO_WAIT, "vhba");
+	LOGINF("TaskMgmt waiting on event notifyevent=0x%p\n",
+	       cmdrsp->scsitaskmgmt.notify);
+	wait_event(notifyevent, notifyresult != 0xffff);
+	LOGINF("TaskMgmt complete; result:%d\n", cmdrsp->scsitaskmgmt.result);
+	kfree(cmdrsp);
+	return SUCCESS;
+}
+
+/* The abort handler returns SUCCESS if it has succeeded to make LLDD
+ * and all related hardware forget about the scmd.
+ */
+static int
+virthba_abort_handler(struct scsi_cmnd *scsicmd)
+{
+	/* issue TASK_MGMT_ABORT_TASK */
+	struct scsi_device *scsidev;
+	struct virtdisk_info *vdisk;
+
+	scsidev = scsicmd->device;
+	for (vdisk = &((struct virthba_info *) scsidev->host->hostdata)->head;
+	     vdisk->next; vdisk = vdisk->next) {
+		if ((scsidev->channel == vdisk->channel)
+		    && (scsidev->id == vdisk->id)
+		    && (scsidev->lun == vdisk->lun)) {
+			if (atomic_read(&vdisk->error_count) <
+			    VIRTHBA_ERROR_COUNT) {
+				atomic_inc(&vdisk->error_count);
+				POSTCODE_LINUX_2(VHBA_COMMAND_HANDLER_PC,
+						 POSTCODE_SEVERITY_INFO);
+			} else
+				atomic_set(&vdisk->ios_threshold,
+					   IOS_ERROR_THRESHOLD);
+		}
+	}
+	return forward_taskmgmt_command(TASK_MGMT_ABORT_TASK, scsicmd->device);
+}
+
+static int
+virthba_bus_reset_handler(struct scsi_cmnd *scsicmd)
+{
+	/* issue TASK_MGMT_TARGET_RESET for each target on the bus */
+	struct scsi_device *scsidev;
+	struct virtdisk_info *vdisk;
+
+	scsidev = scsicmd->device;
+	for (vdisk = &((struct virthba_info *) scsidev->host->hostdata)->head;
+	     vdisk->next; vdisk = vdisk->next) {
+		if ((scsidev->channel == vdisk->channel)
+		    && (scsidev->id == vdisk->id)
+		    && (scsidev->lun == vdisk->lun)) {
+			if (atomic_read(&vdisk->error_count) <
+			    VIRTHBA_ERROR_COUNT) {
+				atomic_inc(&vdisk->error_count);
+				POSTCODE_LINUX_2(VHBA_COMMAND_HANDLER_PC,
+						 POSTCODE_SEVERITY_INFO);
+			} else
+				atomic_set(&vdisk->ios_threshold,
+					   IOS_ERROR_THRESHOLD);
+		}
+	}
+	return forward_taskmgmt_command(TASK_MGMT_BUS_RESET, scsicmd->device);
+}
+
+static int
+virthba_device_reset_handler(struct scsi_cmnd *scsicmd)
+{
+	/* issue TASK_MGMT_LUN_RESET */
+	struct scsi_device *scsidev;
+	struct virtdisk_info *vdisk;
+
+	scsidev = scsicmd->device;
+	for (vdisk = &((struct virthba_info *) scsidev->host->hostdata)->head;
+	     vdisk->next; vdisk = vdisk->next) {
+		if ((scsidev->channel == vdisk->channel)
+		    && (scsidev->id == vdisk->id)
+		    && (scsidev->lun == vdisk->lun)) {
+			if (atomic_read(&vdisk->error_count) <
+			    VIRTHBA_ERROR_COUNT) {
+				atomic_inc(&vdisk->error_count);
+				POSTCODE_LINUX_2(VHBA_COMMAND_HANDLER_PC,
+						 POSTCODE_SEVERITY_INFO);
+			} else
+				atomic_set(&vdisk->ios_threshold,
+					   IOS_ERROR_THRESHOLD);
+		}
+	}
+	return forward_taskmgmt_command(TASK_MGMT_LUN_RESET, scsicmd->device);
+}
+
+static int
+virthba_host_reset_handler(struct scsi_cmnd *scsicmd)
+{
+	/* issue TASK_MGMT_TARGET_RESET for each target on each bus for host */
+	LOGERR("virthba_host_reset_handler Not yet implemented\n");
+	return SUCCESS;
+}
+
+static char virthba_get_info_str[256];
+
+static const char *
+virthba_get_info(struct Scsi_Host *shp)
+{
+	/* Return version string */
+	sprintf(virthba_get_info_str, "virthba, version %s\n", VIRTHBA_VERSION);
+	return virthba_get_info_str;
+}
+
+static int
+virthba_ioctl(struct scsi_device *dev, int cmd, void __user *arg)
+{
+	DBGINF("In virthba_ioctl: ioctl: cmd=0x%x\n", cmd);
+	return -EINVAL;
+}
+
+/* This returns SCSI_MLQUEUE_DEVICE_BUSY if the signal queue to IOpart
+ * is full.
+ */
+static int
+virthba_queue_command_lck(struct scsi_cmnd *scsicmd,
+			  void (*virthba_cmnd_done)(struct scsi_cmnd *))
+{
+	struct scsi_device *scsidev = scsicmd->device;
+	int insert_location;
+	unsigned char op;
+	unsigned char *cdb = scsicmd->cmnd;
+	struct Scsi_Host *scsihost = scsidev->host;
+	struct uiscmdrsp *cmdrsp;
+	unsigned int i;
+	struct virthba_info *virthbainfo =
+	    (struct virthba_info *) scsihost->hostdata;
+	struct scatterlist *sg = NULL;
+	struct scatterlist *sgl = NULL;
+	int sg_failed = 0;
+
+	if (virthbainfo->serverdown || virthbainfo->serverchangingstate) {
+		DBGINF("Server is down/changing state. Returning SCSI_MLQUEUE_DEVICE_BUSY.\n");
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+	}
+
+	ALLOC_CMDRSP(cmdrsp);
+	if (cmdrsp == NULL) {
+		LOGERR("kmalloc of cmdrsp failed.\n");
+		return 1;	/* reject the command */
+	}
+
+	/* now saving everything we need from scsi_cmd into cmdrsp
+	 * before we queue cmdrsp set type to command - as opposed to
+	 * task mgmt
+	 */
+	cmdrsp->cmdtype = CMD_SCSI_TYPE;
+	/* save the pending insertion location.  Deletion from pending
+	 * will return the scsicmd pointer for completion
+	 */
+	insert_location =
+	    add_scsipending_entry(virthbainfo, CMD_SCSI_TYPE, (void *) scsicmd);
+	if (insert_location != -1) {
+		cmdrsp->scsi.scsicmd = (void *) (uintptr_t) insert_location;
+	} else {
+		LOGERR("Queue is full. Returning busy.\n");
+		kfree(cmdrsp);
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+	}
+	/* save done function that we have call when cmd is complete */
+	scsicmd->scsi_done = virthba_cmnd_done;
+	/* save destination */
+	cmdrsp->scsi.vdest.channel = scsidev->channel;
+	cmdrsp->scsi.vdest.id = scsidev->id;
+	cmdrsp->scsi.vdest.lun = scsidev->lun;
+	/* save datadir */
+	cmdrsp->scsi.data_dir = scsicmd->sc_data_direction;
+	memcpy(cmdrsp->scsi.cmnd, cdb, MAX_CMND_SIZE);
+
+	cmdrsp->scsi.bufflen = scsi_bufflen(scsicmd);
+
+	/* keep track of the max buffer length so far. */
+	if (cmdrsp->scsi.bufflen > MaxBuffLen)
+		MaxBuffLen = cmdrsp->scsi.bufflen;
+
+	if (scsi_sg_count(scsicmd) > MAX_PHYS_INFO) {
+		LOGERR("scsicmd use_sg:%d greater than MAX:%d\n",
+		       scsi_sg_count(scsicmd), MAX_PHYS_INFO);
+		del_scsipending_entry(virthbainfo, (uintptr_t) insert_location);
+		kfree(cmdrsp);
+		return 1;	/* reject the command */
+	}
+
+	/* This is what we USED to do when we assumed we were running */
+	/* uissd & virthba on the same Linux system. */
+	/* cmdrsp->scsi.buffer = scsicmd->request_buffer; */
+	/* The following code does NOT make that assumption. */
+	/* convert buffer to phys information */
+	if (scsi_sg_count(scsicmd) == 0) {
+		if (scsi_bufflen(scsicmd) > 0) {
+			LOGERR("**** FAILED No scatter list for bufflen > 0\n");
+			BUG_ON(scsi_sg_count(scsicmd) == 0);
+		}
+		DBGINF("No sg; buffer:0x%p bufflen:%d\n",
+		       scsi_sglist(scsicmd), scsi_bufflen(scsicmd));
+	} else {
+		/* buffer is scatterlist - copy it out */
+		sgl = scsi_sglist(scsicmd);
+
+		for_each_sg(sgl, sg, scsi_sg_count(scsicmd), i) {
+
+			cmdrsp->scsi.gpi_list[i].address = sg_phys(sg);
+			cmdrsp->scsi.gpi_list[i].length = sg->length;
+			if ((i != 0) && (sg->offset != 0))
+				LOGINF("Offset on a sg_entry other than zero =<<%d>>.\n",
+				     sg->offset);
+		}
+
+		if (sg_failed) {
+			LOGERR("Start sg_list dump (entries %d, bufflen %d)...\n",
+			     scsi_sg_count(scsicmd), cmdrsp->scsi.bufflen);
+			for_each_sg(sgl, sg, scsi_sg_count(scsicmd), i) {
+				LOGERR("   Entry(%d): page->[0x%p], phys->[0x%Lx], off(%d), len(%d)\n",
+				     i, sg_page(sg),
+				     (unsigned long long) sg_phys(sg),
+				     sg->offset, sg->length);
+			}
+			LOGERR("Done sg_list dump.\n");
+			/* BUG(); ***** For now, let it fail in uissd
+			 * if it is a problem, as it might just
+			 * work
+			 */
+		}
+
+		cmdrsp->scsi.guest_phys_entries = scsi_sg_count(scsicmd);
+	}
+
+	op = cdb[0];
+	i = uisqueue_put_cmdrsp_with_lock_client(virthbainfo->chinfo.queueinfo,
+						 cmdrsp, IOCHAN_TO_IOPART,
+						 &virthbainfo->chinfo.
+						 insertlock,
+						 DONT_ISSUE_INTERRUPT,
+						 (U64) NULL, DONT_WAIT, "vhba");
+	if (i == 0) {
+		/* queue must be full - and we said don't wait - return busy */
+		LOGERR("uisqueue_put_cmdrsp_with_lock ****FAILED\n");
+		kfree(cmdrsp);
+		del_scsipending_entry(virthbainfo, (uintptr_t) insert_location);
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+	}
+
+	/* we're done with cmdrsp space - data from it has been copied
+	 * into channel - free it now.
+	 */
+	kfree(cmdrsp);
+	return 0;		/* non-zero implies host/device is busy */
+}
+
+static int
+virthba_slave_alloc(struct scsi_device *scsidev)
+{
+	/* this called by the midlayer before scan for new devices -
+	 * LLD can alloc any struc & do init if needed.
+	 */
+	struct virtdisk_info *vdisk;
+	struct virtdisk_info *tmpvdisk;
+	struct virthba_info *virthbainfo;
+	struct Scsi_Host *scsihost = (struct Scsi_Host *) scsidev->host;
+
+	virthbainfo = (struct virthba_info *) scsihost->hostdata;
+	if (!virthbainfo) {
+		LOGERR("Could not find virthba_info for scsihost\n");
+		return 0;	/* even though we errored, treat as success */
+	}
+	for (vdisk = &virthbainfo->head; vdisk->next; vdisk = vdisk->next) {
+		if (vdisk->next->valid &&
+		    (vdisk->next->channel == scsidev->channel) &&
+		    (vdisk->next->id == scsidev->id) &&
+		    (vdisk->next->lun == scsidev->lun))
+			return 0;
+	}
+	tmpvdisk = kmalloc(sizeof(struct virtdisk_info), GFP_ATOMIC);
+	if (!tmpvdisk) {	/* error allocating */
+		LOGERR("Could not allocate memory for disk\n");
+		return 0;
+	}
+	memset(tmpvdisk, 0, sizeof(struct virtdisk_info));
+	tmpvdisk->channel = scsidev->channel;
+	tmpvdisk->id = scsidev->id;
+	tmpvdisk->lun = scsidev->lun;
+	tmpvdisk->valid = 1;
+	vdisk->next = tmpvdisk;
+	return 0;		/* success */
+}
+
+static int
+virthba_slave_configure(struct scsi_device *scsidev)
+{
+	return 0;		/* success */
+}
+
+static void
+virthba_slave_destroy(struct scsi_device *scsidev)
+{
+	/* midlevel calls this after device has been quiesced and
+	 * before it is to be deleted.
+	 */
+	struct virtdisk_info *vdisk, *delvdisk;
+	struct virthba_info *virthbainfo;
+	struct Scsi_Host *scsihost = (struct Scsi_Host *) scsidev->host;
+
+	virthbainfo = (struct virthba_info *) scsihost->hostdata;
+	if (!virthbainfo)
+		LOGERR("Could not find virthba_info for scsihost\n");
+	for (vdisk = &virthbainfo->head; vdisk->next; vdisk = vdisk->next) {
+		if (vdisk->next->valid &&
+		    (vdisk->next->channel == scsidev->channel) &&
+		    (vdisk->next->id == scsidev->id) &&
+		    (vdisk->next->lun == scsidev->lun)) {
+			delvdisk = vdisk->next;
+			vdisk->next = vdisk->next->next;
+			kfree(delvdisk);
+			return;
+		}
+	}
+	return;
+}
+
+/*****************************************************/
+/* Scsi Cmnd support thread                          */
+/*****************************************************/
+
+static void
+do_scsi_linuxstat(struct uiscmdrsp *cmdrsp, struct scsi_cmnd *scsicmd)
+{
+	struct virtdisk_info *vdisk;
+	struct scsi_device *scsidev;
+	struct sense_data *sd;
+
+	scsidev = scsicmd->device;
+	memcpy(scsicmd->sense_buffer, cmdrsp->scsi.sensebuf, MAX_SENSE_SIZE);
+	sd = (struct sense_data *) scsicmd->sense_buffer;
+
+	/* Do not log errors for disk-not-present inquiries */
+	if ((cmdrsp->scsi.cmnd[0] == INQUIRY) &&
+	    (host_byte(cmdrsp->scsi.linuxstat) == DID_NO_CONNECT) &&
+	    (cmdrsp->scsi.addlstat == ADDL_SEL_TIMEOUT))
+		return;
+
+	/* Okay see what our error_count is here.... */
+	for (vdisk = &((struct virthba_info *) scsidev->host->hostdata)->head;
+	     vdisk->next; vdisk = vdisk->next) {
+		if ((scsidev->channel != vdisk->channel)
+		    || (scsidev->id != vdisk->id)
+		    || (scsidev->lun != vdisk->lun))
+			continue;
+
+		if (atomic_read(&vdisk->error_count) < VIRTHBA_ERROR_COUNT) {
+			atomic_inc(&vdisk->error_count);
+			LOGERR("SCSICMD ****FAILED scsicmd:0x%p op:0x%x <%d:%d:%d:%d> 0x%x-0x%x-0x%x-0x%x-0x%x.\n",
+			       scsicmd, cmdrsp->scsi.cmnd[0],
+			       scsidev->host->host_no, scsidev->id,
+			       scsidev->channel, scsidev->lun,
+			       cmdrsp->scsi.linuxstat, sd->Valid, sd->SenseKey,
+			       sd->AdditionalSenseCode,
+			       sd->AdditionalSenseCodeQualifier);
+			if (atomic_read(&vdisk->error_count) ==
+			    VIRTHBA_ERROR_COUNT) {
+				LOGERR("Throtling SCSICMD errors disk <%d:%d:%d:%d>\n",
+				     scsidev->host->host_no, scsidev->id,
+				     scsidev->channel, scsidev->lun);
+			}
+			atomic_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
+		}
+	}
+}
+
+static void
+do_scsi_nolinuxstat(struct uiscmdrsp *cmdrsp, struct scsi_cmnd *scsicmd)
+{
+	struct scsi_device *scsidev;
+	unsigned char buf[36];
+	struct scatterlist *sg;
+	unsigned int i;
+	char *thispage;
+	char *thispage_orig;
+	int bufind = 0;
+	struct virtdisk_info *vdisk;
+
+	scsidev = scsicmd->device;
+	if ((cmdrsp->scsi.cmnd[0] == INQUIRY)
+	    && (cmdrsp->scsi.bufflen >= MIN_INQUIRY_RESULT_LEN)) {
+		if (cmdrsp->scsi.no_disk_result == 0)
+			return;
+
+		/* Linux scsi code is weird; it wants
+		 * a device at Lun 0 to issue report
+		 * luns, but we don't want a disk
+		 * there so we'll present a processor
+		 * there. */
+		SET_NO_DISK_INQUIRY_RESULT(buf, cmdrsp->scsi.bufflen,
+					   scsidev->lun,
+					   DEV_DISK_CAPABLE_NOT_PRESENT,
+					   DEV_NOT_CAPABLE);
+
+		if (scsi_sg_count(scsicmd) == 0) {
+			if (scsi_bufflen(scsicmd) > 0) {
+				LOGERR("**** FAILED No scatter list for bufflen > 0\n");
+				BUG_ON(scsi_sg_count(scsicmd) ==
+				       0);
+			}
+			memcpy(scsi_sglist(scsicmd), buf,
+			       cmdrsp->scsi.bufflen);
+			return;
+		}
+
+		sg = scsi_sglist(scsicmd);
+		for (i = 0; i < scsi_sg_count(scsicmd); i++) {
+			DBGVER("copying OUT OF buf into 0x%p %d\n",
+			     sg_page(sg + i), sg[i].length);
+			thispage_orig = kmap_atomic(sg_page(sg + i));
+			thispage = (void *) ((unsigned long)thispage_orig |
+					     sg[i].offset);
+			memcpy(thispage, buf + bufind, sg[i].length);
+			kunmap_atomic(thispage_orig);
+			bufind += sg[i].length;
+		}
+	} else {
+
+		vdisk = &((struct virthba_info *)scsidev->host->hostdata)->head;
+		for ( ; vdisk->next; vdisk = vdisk->next) {
+			if ((scsidev->channel != vdisk->channel)
+			    || (scsidev->id != vdisk->id)
+			    || (scsidev->lun != vdisk->lun))
+				continue;
+
+			if (atomic_read(&vdisk->ios_threshold) > 0) {
+				atomic_dec(&vdisk->ios_threshold);
+				if (atomic_read(&vdisk->ios_threshold) == 0) {
+					LOGERR("Resetting error count for disk\n");
+					atomic_set(&vdisk->error_count, 0);
+				}
+			}
+		}
+	}
+}
+
+static void
+complete_scsi_command(struct uiscmdrsp *cmdrsp, struct scsi_cmnd *scsicmd)
+{
+	DBGINF("cmdrsp: 0x%p, scsistat:0x%x.\n", cmdrsp, cmdrsp->scsi.scsistat);
+
+	/* take what we need out of cmdrsp and complete the scsicmd */
+	scsicmd->result = cmdrsp->scsi.linuxstat;
+	if (cmdrsp->scsi.linuxstat)
+		do_scsi_linuxstat(cmdrsp, scsicmd);
+	else
+		do_scsi_nolinuxstat(cmdrsp, scsicmd);
+
+	if (scsicmd->scsi_done) {
+		DBGVER("Scsi_DONE\n");
+		scsicmd->scsi_done(scsicmd);
+	}
+}
+
+static inline void
+complete_vdiskmgmt_command(struct uiscmdrsp *cmdrsp)
+{
+	/* copy the result of the taskmgmt and */
+	/* wake up the error handler that is waiting for this */
+	*(int *) cmdrsp->vdiskmgmt.notifyresult = cmdrsp->vdiskmgmt.result;
+	wake_up_all((wait_queue_head_t *) cmdrsp->vdiskmgmt.notify);
+	LOGINF("set notify result to %d\n", cmdrsp->vdiskmgmt.result);
+}
+
+static inline void
+complete_taskmgmt_command(struct uiscmdrsp *cmdrsp)
+{
+	/* copy the result of the taskmgmt and */
+	/* wake up the error handler that is waiting for this */
+	*(int *) cmdrsp->scsitaskmgmt.notifyresult =
+	    cmdrsp->scsitaskmgmt.result;
+	wake_up_all((wait_queue_head_t *) cmdrsp->scsitaskmgmt.notify);
+	LOGINF("set notify result to %d\n", cmdrsp->scsitaskmgmt.result);
+}
+
+static void
+drain_queue(struct virthba_info *virthbainfo, struct chaninfo *dc,
+		struct uiscmdrsp *cmdrsp)
+{
+	unsigned long flags;
+	int qrslt = 0;
+	struct scsi_cmnd *scsicmd;
+	struct Scsi_Host *shost = virthbainfo->scsihost;
+
+	while (1) {
+		spin_lock_irqsave(&virthbainfo->chinfo.insertlock, flags);
+		if (!ULTRA_CHANNEL_CLIENT_ACQUIRE_OS(dc->queueinfo->chan,
+						     "vhba", NULL)) {
+			spin_unlock_irqrestore(&virthbainfo->chinfo.insertlock,
+					       flags);
+			virthbainfo->acquire_failed_cnt++;
+			break;
+		}
+		qrslt = uisqueue_get_cmdrsp(dc->queueinfo, cmdrsp,
+					    IOCHAN_FROM_IOPART);
+		ULTRA_CHANNEL_CLIENT_RELEASE_OS(dc->queueinfo->chan,
+						"vhba", NULL);
+		spin_unlock_irqrestore(&virthbainfo->chinfo.insertlock, flags);
+		if (qrslt == 0)
+			break;
+		if (cmdrsp->cmdtype == CMD_SCSI_TYPE) {
+			/* scsicmd location is returned by the
+			 * deletion
+			 */
+			scsicmd = del_scsipending_entry(virthbainfo,
+					(uintptr_t) cmdrsp->scsi.scsicmd);
+			if (!scsicmd)
+				break;
+			/* complete the orig cmd */
+			complete_scsi_command(cmdrsp, scsicmd);
+		} else if (cmdrsp->cmdtype == CMD_SCSITASKMGMT_TYPE) {
+			if (!del_scsipending_entry(virthbainfo,
+				   (uintptr_t) cmdrsp->scsitaskmgmt.scsicmd))
+				break;
+			complete_taskmgmt_command(cmdrsp);
+		} else if (cmdrsp->cmdtype == CMD_NOTIFYGUEST_TYPE) {
+			/* The vHba pointer has no meaning in
+			 * a Client/Guest Partition. Let's be
+			 * safe and set it to NULL now.  Do
+			 * not use it here! */
+			cmdrsp->disknotify.vHba = NULL;
+			process_disk_notify(shost, cmdrsp);
+		} else if (cmdrsp->cmdtype == CMD_VDISKMGMT_TYPE) {
+			if (!del_scsipending_entry(virthbainfo,
+				   (uintptr_t) cmdrsp->vdiskmgmt.scsicmd))
+				break;
+			complete_vdiskmgmt_command(cmdrsp);
+		} else
+			LOGERR("Invalid cmdtype %d\n", cmdrsp->cmdtype);
+		/* cmdrsp is now available for reuse */
+	}
+}
+
+
+/* main function for the thread that waits for scsi commands to arrive
+ * in a specified queue
+ */
+static int
+process_incoming_rsps(void *v)
+{
+	struct virthba_info *virthbainfo = v;
+	struct chaninfo *dc = &virthbainfo->chinfo;
+	struct uiscmdrsp *cmdrsp = NULL;
+	const int SZ = sizeof(struct uiscmdrsp);
+	U64 mask;
+	unsigned long long rc1;
+
+	UIS_DAEMONIZE("vhba_incoming");
+	/* alloc once and reuse */
+	cmdrsp = kmalloc(SZ, GFP_ATOMIC);
+	if (cmdrsp == NULL) {
+		LOGERR("process_incoming_rsps ****FAILED to malloc - thread exiting\n");
+		complete_and_exit(&dc->threadinfo.has_stopped, 0);
+		return 0;
+	}
+	mask = ULTRA_CHANNEL_ENABLE_INTS;
+	while (1) {
+		wait_event_interruptible_timeout(virthbainfo->rsp_queue,
+			 (atomic_read(&virthbainfo->interrupt_rcvd) == 1),
+					 usecs_to_jiffies(rsltq_wait_usecs));
+		atomic_set(&virthbainfo->interrupt_rcvd, 0);
+		/* drain queue */
+		drain_queue(virthbainfo, dc, cmdrsp);
+		rc1 = uisqueue_InterlockedOr(virthbainfo->flags_addr, mask);
+		if (dc->threadinfo.should_stop)
+			break;
+	}
+
+	kfree(cmdrsp);
+
+	DBGINF("exiting processing incoming rsps.\n");
+	complete_and_exit(&dc->threadinfo.has_stopped, 0);
+}
+
+/*****************************************************/
+/* proc filesystem functions						 */
+/*****************************************************/
+
+static ssize_t
+info_proc_read(struct file *file, char __user *buf, size_t len, loff_t *offset)
+{
+	int length = 0;
+	U64 phys_flags_addr;
+	int i;
+	struct virthba_info *virthbainfo;
+	char *vbuf;
+	loff_t pos = *offset;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	if (pos > 0 || !len)
+		return 0;
+
+	vbuf = kzalloc(len, GFP_KERNEL);
+	if (!vbuf)
+		return -ENOMEM;
+
+	for (i = 0; i < VIRTHBASOPENMAX; i++) {
+		if (VirtHbasOpen[i].virthbainfo == NULL)
+			continue;
+
+		virthbainfo = VirtHbasOpen[i].virthbainfo;
+		length += sprintf(vbuf + length, "CHANSOCK is not defined.\n");
+
+		length += sprintf(vbuf + length, "MaxBuffLen:%d\n", MaxBuffLen);
+
+		length += sprintf(vbuf + length, "\nvirthba result queue poll wait:%d usecs.\n",
+				  rsltq_wait_usecs);
+
+		length += sprintf(vbuf + length,
+				  "\nModule build: Date:%s Time:%s\n",
+				  __DATE__, __TIME__);
+		length += sprintf(vbuf + length, "\ninterrupts_rcvd = %llu, interrupts_disabled = %llu\n",
+				  virthbainfo->interrupts_rcvd,
+				  virthbainfo->interrupts_disabled);
+		length += sprintf(vbuf + length, "\ninterrupts_notme = %llu,\n",
+				  virthbainfo->interrupts_notme);
+		phys_flags_addr = virt_to_phys(virthbainfo->flags_addr);
+
+		length += sprintf(vbuf + length, "flags_addr = %p, phys_flags_addr=0x%016llx, FeatureFlags=%llu\n",
+			  virthbainfo->flags_addr, phys_flags_addr,
+			  *virthbainfo->flags_addr);
+		length += sprintf(vbuf + length, "acquire_failed_cnt:%llu\n",
+				  virthbainfo->acquire_failed_cnt);
+
+		length += sprintf(vbuf + length, "\n");
+	}
+	if (copy_to_user(buf, vbuf, length)) {
+		kfree(vbuf);
+		return -EFAULT;
+	}
+
+	kfree(vbuf);
+	*offset += length;
+	return length;
+}
+
+static ssize_t
+enable_ints_read(struct file *file, char __user *buffer,
+		  size_t count, loff_t *ppos)
+{
+	return 0;
+}
+
+static ssize_t
+enable_ints_write(struct file *file, const char __user *buffer,
+		  size_t count, loff_t *ppos)
+{
+	char buf[count + 1];
+	int i, new_value;
+	struct virthba_info *virthbainfo;
+	U64 *Features_addr;
+	U64 mask;
+
+	buf[count] = '\0';
+	if (copy_from_user(buf, buffer, count)) {
+		LOGERR("copy_from_user failed. buf<<%.*s>> count<<%lu>>\n",
+		       (int) count, buf, count);
+		return -EFAULT;
+	}
+
+	i = sscanf(buf, "%d", &new_value);
+
+	if (i < 1) {
+		LOGERR("Failed to scan value for enable_ints, buf<<%.*s>>",
+		       (int) count, buf);
+		return -EFAULT;
+	}
+
+	/* set all counts to new_value usually 0 */
+	for (i = 0; i < VIRTHBASOPENMAX; i++) {
+		if (VirtHbasOpen[i].virthbainfo != NULL) {
+			virthbainfo = VirtHbasOpen[i].virthbainfo;
+			Features_addr =
+				&virthbainfo->chinfo.queueinfo->chan->Features;
+			if (new_value == 1) {
+				mask = ~(ULTRA_IO_CHANNEL_IS_POLLING |
+					 ULTRA_IO_DRIVER_DISABLES_INTS);
+				uisqueue_InterlockedAnd(Features_addr, mask);
+				mask = ULTRA_IO_DRIVER_ENABLES_INTS;
+				uisqueue_InterlockedOr(Features_addr, mask);
+				rsltq_wait_usecs = 4000000;
+			} else {
+				mask = ~(ULTRA_IO_DRIVER_ENABLES_INTS |
+					 ULTRA_IO_DRIVER_DISABLES_INTS);
+				uisqueue_InterlockedAnd(Features_addr, mask);
+				mask = ULTRA_IO_CHANNEL_IS_POLLING;
+				uisqueue_InterlockedOr(Features_addr, mask);
+				rsltq_wait_usecs = 4000;
+			}
+		}
+	}
+	return count;
+}
+
+static ssize_t
+rqwu_proc_write(struct file *file, const char __user *buffer,
+		size_t count, loff_t *ppos)
+{
+	char buf[count];
+	int i, usecs;
+
+	if (copy_from_user(buf, buffer, count)) {
+		LOGERR("copy_from_user failed. buf<<%.*s>> count<<%lu>>\n",
+		       (int) count, buf, count);
+		return -EFAULT;
+	}
+
+	i = sscanf(buf, "%d", &usecs);
+
+	if (i < 1) {
+		LOGERR("Failed to scan value for rqwait_usecs buf<<%.*s>>",
+		       (int) count, buf);
+		return -EFAULT;
+	}
+
+	/* set global wait time */
+	rsltq_wait_usecs = usecs;
+	return count;
+}
+
+/* As per VirtpciFunc returns 1 for success and 0 for failure */
+static int
+virthba_serverup(struct virtpci_dev *virtpcidev)
+{
+	struct virthba_info *virthbainfo =
+	    (struct virthba_info *) ((struct Scsi_Host *) virtpcidev->scsi.
+				     scsihost)->hostdata;
+
+	DBGINF("virtpcidev busNo<<%d>>devNo<<%d>>", virtpcidev->busNo,
+	       virtpcidev->deviceNo);
+
+	if (!virthbainfo->serverdown) {
+		DBGINF("Server up message recieved while server is already up.\n");
+		return 1;
+	}
+	if (virthbainfo->serverchangingstate) {
+		LOGERR("Server already processing change state message\n");
+		return 0;
+	}
+
+	virthbainfo->serverchangingstate = true;
+	/* Must transition channel to ATTACHED state BEFORE we
+	 * can start using the device again
+	 */
+	ULTRA_CHANNEL_CLIENT_TRANSITION(virthbainfo->chinfo.queueinfo->chan,
+					dev_name(&virtpcidev->generic_dev),
+					CliStateOS,
+					CHANNELCLI_ATTACHED, NULL);
+
+	/* Start Processing the IOVM Response Queue Again */
+	if (!uisthread_start(&virthbainfo->chinfo.threadinfo,
+			     process_incoming_rsps,
+			     virthbainfo, "vhba_incoming")) {
+		LOGERR("uisthread_start rsp ****FAILED\n");
+		return 0;
+	}
+	virthbainfo->serverdown = false;
+	virthbainfo->serverchangingstate = false;
+
+	return 1;
+}
+
+static void
+virthba_serverdown_complete(struct work_struct *work)
+{
+	struct virthba_info *virthbainfo;
+	struct virtpci_dev *virtpcidev;
+	int i;
+	struct scsipending *pendingdel = NULL;
+	struct scsi_cmnd *scsicmd = NULL;
+	struct uiscmdrsp *cmdrsp;
+	unsigned long flags;
+
+	virthbainfo = container_of(work, struct virthba_info,
+				   serverdown_completion);
+
+	/* Stop Using the IOVM Response Queue (queue should be drained
+	 * by the end)
+	 */
+	uisthread_stop(&virthbainfo->chinfo.threadinfo);
+
+	/* Fail Commands that weren't completed */
+	spin_lock_irqsave(&virthbainfo->privlock, flags);
+	for (i = 0; i < MAX_PENDING_REQUESTS; i++) {
+		pendingdel = &(virthbainfo->pending[i]);
+		switch (pendingdel->cmdtype) {
+		case CMD_SCSI_TYPE:
+			scsicmd = (struct scsi_cmnd *) pendingdel->sent;
+			scsicmd->result = (DID_RESET << 16);
+			if (scsicmd->scsi_done)
+				scsicmd->scsi_done(scsicmd);
+			break;
+		case CMD_SCSITASKMGMT_TYPE:
+			cmdrsp = (struct uiscmdrsp *) pendingdel->sent;
+			DBGINF("cmdrsp=0x%x, notify=0x%x\n", cmdrsp,
+			       cmdrsp->scsitaskmgmt.notify);
+			*(int *) cmdrsp->scsitaskmgmt.notifyresult =
+			    TASK_MGMT_FAILED;
+			wake_up_all((wait_queue_head_t *)
+				    cmdrsp->scsitaskmgmt.notify);
+			break;
+		case CMD_VDISKMGMT_TYPE:
+			cmdrsp = (struct uiscmdrsp *) pendingdel->sent;
+			*(int *) cmdrsp->vdiskmgmt.notifyresult =
+			    VDISK_MGMT_FAILED;
+			wake_up_all((wait_queue_head_t *)
+				    cmdrsp->vdiskmgmt.notify);
+			break;
+		default:
+			if (pendingdel->sent != NULL)
+				LOGERR("Unknown command type: 0x%x.  Only freeing list structure.\n",
+				     pendingdel->cmdtype);
+		}
+		pendingdel->cmdtype = 0;
+		pendingdel->sent = NULL;
+	}
+	spin_unlock_irqrestore(&virthbainfo->privlock, flags);
+
+	virtpcidev = virthbainfo->virtpcidev;
+
+	DBGINF("virtpcidev busNo<<%d>>devNo<<%d>>", virtpcidev->busNo,
+	       virtpcidev->deviceNo);
+	virthbainfo->serverdown = true;
+	virthbainfo->serverchangingstate = false;
+	/* Return the ServerDown response to Command */
+	device_pause_response(virtpcidev->busNo, virtpcidev->deviceNo, 0);
+}
+
+/* As per VirtpciFunc returns 1 for success and 0 for failure */
+static int
+virthba_serverdown(struct virtpci_dev *virtpcidev, u32 state)
+{
+	struct virthba_info *virthbainfo =
+	    (struct virthba_info *) ((struct Scsi_Host *) virtpcidev->scsi.
+				     scsihost)->hostdata;
+
+	DBGINF("virthba_serverdown");
+	DBGINF("virtpcidev busNo<<%d>>devNo<<%d>>", virtpcidev->busNo,
+	       virtpcidev->deviceNo);
+
+	if (!virthbainfo->serverdown && !virthbainfo->serverchangingstate) {
+		virthbainfo->serverchangingstate = true;
+		queue_work(virthba_serverdown_workqueue,
+			   &virthbainfo->serverdown_completion);
+	} else if (virthbainfo->serverchangingstate) {
+		LOGERR("Server already processing change state message\n");
+		return 0;
+	} else
+		LOGERR("Server already down, but another server down message received.");
+
+	return 1;
+}
+
+/*****************************************************/
+/* Module Init & Exit functions                      */
+/*****************************************************/
+
+static int __init
+virthba_parse_line(char *str)
+{
+	DBGINF("In virthba_parse_line %s\n", str);
+	return 1;
+}
+
+static void __init
+virthba_parse_options(char *line)
+{
+	char *next = line;
+
+	POSTCODE_LINUX_2(VHBA_CREATE_ENTRY_PC, POSTCODE_SEVERITY_INFO);
+	if (line == NULL || !*line)
+		return;
+	while ((line = next) != NULL) {
+		next = strchr(line, ' ');
+		if (next != NULL)
+			*next++ = 0;
+		if (!virthba_parse_line(line))
+			DBGINF("Unknown option '%s'\n", line);
+	}
+
+	POSTCODE_LINUX_2(VHBA_CREATE_EXIT_PC, POSTCODE_SEVERITY_INFO);
+}
+
+static int __init
+virthba_mod_init(void)
+{
+	int error;
+	int i;
+
+	LOGINF("Entering virthba_mod_init...\n");
+
+	POSTCODE_LINUX_2(VHBA_CREATE_ENTRY_PC, POSTCODE_SEVERITY_INFO);
+	virthba_parse_options(virthba_options);
+
+	error = virtpci_register_driver(&virthba_driver);
+	if (error < 0) {
+		LOGERR("register ****FAILED 0x%x\n", error);
+		POSTCODE_LINUX_3(VHBA_CREATE_FAILURE_PC, error,
+				 POSTCODE_SEVERITY_ERR);
+	} else {
+		/* create the proc directories */
+		virthba_proc_dir = proc_mkdir(DIR_PROC_ENTRY, NULL);
+		info_proc_entry = proc_create(INFO_PROC_ENTRY_FN, 0,
+					      virthba_proc_dir,
+					      &proc_info_fops);
+		rqwaitus_proc_entry = proc_create(RQWU_PROC_ENTRY_FN, 0,
+						  virthba_proc_dir,
+						  &proc_rqwu_fops);
+		enable_ints_proc_entry = proc_create(ENABLE_INTS_ENTRY_FN, 0,
+						     virthba_proc_dir,
+						     &proc_enable_ints_fops);
+
+		/* Initialize DARWorkQ */
+		INIT_WORK(&DARWorkQ, doDiskAddRemove);
+		spin_lock_init(&DARWorkQLock);
+
+		/* clear out array */
+		for (i = 0; i < VIRTHBASOPENMAX; i++)
+			VirtHbasOpen[i].virthbainfo = NULL;
+		/* Initialize the serverdown workqueue */
+		virthba_serverdown_workqueue =
+		    create_singlethread_workqueue("virthba_serverdown");
+		if (virthba_serverdown_workqueue == NULL) {
+			LOGERR("**** FAILED virthba_serverdown_workqueue creation\n");
+			POSTCODE_LINUX_2(VHBA_CREATE_FAILURE_PC,
+					 POSTCODE_SEVERITY_ERR);
+			error = -1;
+		}
+	}
+
+	POSTCODE_LINUX_2(VHBA_CREATE_EXIT_PC, POSTCODE_SEVERITY_INFO);
+	LOGINF("Leaving virthba_mod_init\n");
+	return error;
+}
+
+static ssize_t
+virthba_acquire_lun(struct device *cdev, struct device_attribute *attr,
+		    const char *buf, size_t count)
+{
+	struct uisscsi_dest vdest;
+	struct Scsi_Host *shost = class_to_shost(cdev);
+	int i;
+
+	i = sscanf(buf, "%d-%d-%d", &vdest.channel, &vdest.id, &vdest.lun);
+	if (i != 3)
+		return i;
+
+	return forward_vdiskmgmt_command(VDISK_MGMT_ACQUIRE, shost, &vdest);
+}
+
+static ssize_t
+virthba_release_lun(struct device *cdev, struct device_attribute *attr,
+		    const char *buf, size_t count)
+{
+	struct uisscsi_dest vdest;
+	struct Scsi_Host *shost = class_to_shost(cdev);
+	int i;
+
+	i = sscanf(buf, "%d-%d-%d", &vdest.channel, &vdest.id, &vdest.lun);
+	if (i != 3)
+		return i;
+
+	return forward_vdiskmgmt_command(VDISK_MGMT_RELEASE, shost, &vdest);
+}
+
+#define CLASS_DEVICE_ATTR(_name, _mode, _show, _store)      \
+	struct device_attribute class_device_attr_##_name =   \
+		__ATTR(_name, _mode, _show, _store)
+
+static CLASS_DEVICE_ATTR(acquire_lun, S_IWUSR, NULL, virthba_acquire_lun);
+static CLASS_DEVICE_ATTR(release_lun, S_IWUSR, NULL, virthba_release_lun);
+
+static DEVICE_ATTRIBUTE *virthba_shost_attrs[] = {
+	&class_device_attr_acquire_lun,
+	&class_device_attr_release_lun,
+	NULL
+};
+
+static void __exit
+virthba_mod_exit(void)
+{
+	LOGINF("entering virthba_mod_exit...\n");
+
+	virtpci_unregister_driver(&virthba_driver);
+	/* unregister is going to call virthba_remove */
+	/* destroy serverdown completion workqueue */
+	if (virthba_serverdown_workqueue) {
+		destroy_workqueue(virthba_serverdown_workqueue);
+		virthba_serverdown_workqueue = NULL;
+	}
+
+	if (info_proc_entry)
+		remove_proc_entry(INFO_PROC_ENTRY_FN, virthba_proc_dir);
+
+	if (rqwaitus_proc_entry)
+		remove_proc_entry(RQWU_PROC_ENTRY_FN, NULL);
+
+	if (enable_ints_proc_entry)
+		remove_proc_entry(ENABLE_INTS_ENTRY_FN, NULL);
+
+	if (virthba_proc_dir)
+		remove_proc_entry(DIR_PROC_ENTRY, NULL);
+
+	LOGINF("Leaving virthba_mod_exit\n");
+
+}
+
+/* specify function to be run at module insertion time */
+module_init(virthba_mod_init);
+
+/* specify function to be run when module is removed */
+module_exit(virthba_mod_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Usha Srinivasan");
+MODULE_ALIAS("uisvirthba");
+	/* this is extracted during depmod and kept in modules.dep */
+/* module parameter */
+module_param(virthba_options, charp, S_IRUGO);

drivers/staging/unisys/virthba/virthba.h

@@ -0,0 +1,31 @@
+/* virthba.h
+ *
+ * Copyright © 2010 - 2013 UNISYS CORPORATION
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ */
+
+/*
+ * Unisys Virtual HBA driver header
+ */
+
+
+
+#ifndef __VIRTHBA_H__
+#define __VIRTHBA_H__
+
+
+#define VIRTHBA_VERSION "01.00"
+
+
+#endif /* __VIRTHBA_H__ */