[SCSI] target: Add LIO target core v4.0.0-rc6

LIO target is a full featured in-kernel target framework with the
following feature set:

High-performance, non-blocking, multithreaded architecture with SIMD
support.

Advanced SCSI feature set:

    * Persistent Reservations (PRs)
    * Asymmetric Logical Unit Assignment (ALUA)
    * Protocol and intra-nexus multiplexing, load-balancing and failover (MC/S)
    * Full Error Recovery (ERL=0,1,2)
    * Active/active task migration and session continuation (ERL=2)
    * Thin LUN provisioning (UNMAP and WRITE_SAMExx)

Multiprotocol target plugins

Storage media independence:

    * Virtualization of all storage media; transparent mapping of IO to LUNs
    * No hard limits on number of LUNs per Target; maximum LUN size ~750 TB
    * Backstores: SATA, SAS, SCSI, BluRay, DVD, FLASH, USB, ramdisk, etc.

Standards compliance:

    * Full compliance with IETF (RFC 3720)
    * Full implementation of SPC-4 PRs and ALUA

Significant code cleanups done by Christoph Hellwig.

[jejb: fix up for new block bdev exclusive interface. Minor fixes from
 Randy Dunlap and Dan Carpenter.]
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 1470 insertions, 0 deletions

diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
new file mode 100644
index 000000000000..742d24609a9b
--- /dev/null
+++ b/drivers/target/target_core_pscsi.c
@@ -0,0 +1,1470 @@
+/*******************************************************************************
+ * Filename:  target_core_pscsi.c
+ *
+ * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
+ *
+ * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
+ * Copyright (c) 2005, 2006, 2007 SBE, Inc.
+ * Copyright (c) 2007-2010 Rising Tide Systems
+ * Copyright (c) 2008-2010 Linux-iSCSI.org
+ *
+ * Nicholas A. Bellinger <nab@kernel.org>
+ *
+ * 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.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ ******************************************************************************/
+
+#include <linux/version.h>
+#include <linux/string.h>
+#include <linux/parser.h>
+#include <linux/timer.h>
+#include <linux/blkdev.h>
+#include <linux/blk_types.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/smp_lock.h>
+#include <linux/genhd.h>
+#include <linux/cdrom.h>
+#include <linux/file.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <scsi/libsas.h> /* For TASK_ATTR_* */
+
+#include <target/target_core_base.h>
+#include <target/target_core_device.h>
+#include <target/target_core_transport.h>
+
+#include "target_core_pscsi.h"
+
+#define ISPRINT(a)  ((a >= ' ') && (a <= '~'))
+
+static struct se_subsystem_api pscsi_template;
+
+static void pscsi_req_done(struct request *, int);
+
+/*	pscsi_get_sh():
+ *
+ *
+ */
+static struct Scsi_Host *pscsi_get_sh(u32 host_no)
+{
+	struct Scsi_Host *sh = NULL;
+
+	sh = scsi_host_lookup(host_no);
+	if (IS_ERR(sh)) {
+		printk(KERN_ERR "Unable to locate SCSI HBA with Host ID:"
+				" %u\n", host_no);
+		return NULL;
+	}
+
+	return sh;
+}
+
+/*	pscsi_attach_hba():
+ *
+ * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
+ *	from the passed SCSI Host ID.
+ */
+static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
+{
+	int hba_depth;
+	struct pscsi_hba_virt *phv;
+
+	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
+	if (!(phv)) {
+		printk(KERN_ERR "Unable to allocate struct pscsi_hba_virt\n");
+		return -1;
+	}
+	phv->phv_host_id = host_id;
+	phv->phv_mode = PHV_VIRUTAL_HOST_ID;
+	hba_depth = PSCSI_VIRTUAL_HBA_DEPTH;
+	atomic_set(&hba->left_queue_depth, hba_depth);
+	atomic_set(&hba->max_queue_depth, hba_depth);
+
+	hba->hba_ptr = (void *)phv;
+
+	printk(KERN_INFO "CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
+		" Generic Target Core Stack %s\n", hba->hba_id,
+		PSCSI_VERSION, TARGET_CORE_MOD_VERSION);
+	printk(KERN_INFO "CORE_HBA[%d] - Attached SCSI HBA to Generic"
+		" Target Core with TCQ Depth: %d\n", hba->hba_id,
+		atomic_read(&hba->max_queue_depth));
+
+	return 0;
+}
+
+static void pscsi_detach_hba(struct se_hba *hba)
+{
+	struct pscsi_hba_virt *phv = hba->hba_ptr;
+	struct Scsi_Host *scsi_host = phv->phv_lld_host;
+
+	if (scsi_host) {
+		scsi_host_put(scsi_host);
+
+		printk(KERN_INFO "CORE_HBA[%d] - Detached SCSI HBA: %s from"
+			" Generic Target Core\n", hba->hba_id,
+			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
+			"Unknown");
+	} else
+		printk(KERN_INFO "CORE_HBA[%d] - Detached Virtual SCSI HBA"
+			" from Generic Target Core\n", hba->hba_id);
+
+	kfree(phv);
+	hba->hba_ptr = NULL;
+}
+
+static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
+{
+	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)hba->hba_ptr;
+	struct Scsi_Host *sh = phv->phv_lld_host;
+	int hba_depth = PSCSI_VIRTUAL_HBA_DEPTH;
+	/*
+	 * Release the struct Scsi_Host
+	 */
+	if (!(mode_flag)) {
+		if (!(sh))
+			return 0;
+
+		phv->phv_lld_host = NULL;
+		phv->phv_mode = PHV_VIRUTAL_HOST_ID;
+		atomic_set(&hba->left_queue_depth, hba_depth);
+		atomic_set(&hba->max_queue_depth, hba_depth);
+
+		printk(KERN_INFO "CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
+			" %s\n", hba->hba_id, (sh->hostt->name) ?
+			(sh->hostt->name) : "Unknown");
+
+		scsi_host_put(sh);
+		return 0;
+	}
+	/*
+	 * Otherwise, locate struct Scsi_Host from the original passed
+	 * pSCSI Host ID and enable for phba mode
+	 */
+	sh = pscsi_get_sh(phv->phv_host_id);
+	if (!(sh)) {
+		printk(KERN_ERR "pSCSI: Unable to locate SCSI Host for"
+			" phv_host_id: %d\n", phv->phv_host_id);
+		return -1;
+	}
+	/*
+	 * Usually the SCSI LLD will use the hostt->can_queue value to define
+	 * its HBA TCQ depth.  Some other drivers (like 2.6 megaraid) don't set
+	 * this at all and set sh->can_queue at runtime.
+	 */
+	hba_depth = (sh->hostt->can_queue > sh->can_queue) ?
+		sh->hostt->can_queue : sh->can_queue;
+
+	atomic_set(&hba->left_queue_depth, hba_depth);
+	atomic_set(&hba->max_queue_depth, hba_depth);
+
+	phv->phv_lld_host = sh;
+	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
+
+	printk(KERN_INFO "CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
+		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
+
+	return 1;
+}
+
+static void pscsi_tape_read_blocksize(struct se_device *dev,
+		struct scsi_device *sdev)
+{
+	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
+	int ret;
+
+	buf = kzalloc(12, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	memset(cdb, 0, MAX_COMMAND_SIZE);
+	cdb[0] = MODE_SENSE;
+	cdb[4] = 0x0c; /* 12 bytes */
+
+	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
+			HZ, 1, NULL);
+	if (ret)
+		goto out_free;
+
+	/*
+	 * If MODE_SENSE still returns zero, set the default value to 1024.
+	 */
+	sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
+	if (!sdev->sector_size)
+		sdev->sector_size = 1024;
+out_free:
+	kfree(buf);
+}
+
+static void
+pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
+{
+	unsigned char *buf;
+
+	if (sdev->inquiry_len < INQUIRY_LEN)
+		return;
+
+	buf = sdev->inquiry;
+	if (!buf)
+		return;
+	/*
+	 * Use sdev->inquiry from drivers/scsi/scsi_scan.c:scsi_alloc_sdev()
+	 */
+	memcpy(&wwn->vendor[0], &buf[8], sizeof(wwn->vendor));
+	memcpy(&wwn->model[0], &buf[16], sizeof(wwn->model));
+	memcpy(&wwn->revision[0], &buf[32], sizeof(wwn->revision));
+}
+
+static int
+pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
+{
+	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
+	int ret;
+
+	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
+	if (!buf)
+		return -1;
+
+	memset(cdb, 0, MAX_COMMAND_SIZE);
+	cdb[0] = INQUIRY;
+	cdb[1] = 0x01; /* Query VPD */
+	cdb[2] = 0x80; /* Unit Serial Number */
+	cdb[3] = (INQUIRY_VPD_SERIAL_LEN >> 8) & 0xff;
+	cdb[4] = (INQUIRY_VPD_SERIAL_LEN & 0xff);
+
+	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
+			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
+	if (ret)
+		goto out_free;
+
+	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
+
+	wwn->t10_sub_dev->su_dev_flags |= SDF_FIRMWARE_VPD_UNIT_SERIAL;
+
+	kfree(buf);
+	return 0;
+
+out_free:
+	kfree(buf);
+	return -1;
+}
+
+static void
+pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
+		struct t10_wwn *wwn)
+{
+	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
+	int ident_len, page_len, off = 4, ret;
+	struct t10_vpd *vpd;
+
+	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	memset(cdb, 0, MAX_COMMAND_SIZE);
+	cdb[0] = INQUIRY;
+	cdb[1] = 0x01; /* Query VPD */
+	cdb[2] = 0x83; /* Device Identifier */
+	cdb[3] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN >> 8) & 0xff;
+	cdb[4] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN & 0xff);
+
+	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
+			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
+			      NULL, HZ, 1, NULL);
+	if (ret)
+		goto out;
+
+	page_len = (buf[2] << 8) | buf[3];
+	while (page_len > 0) {
+		/* Grab a pointer to the Identification descriptor */
+		page_83 = &buf[off];
+		ident_len = page_83[3];
+		if (!ident_len) {
+			printk(KERN_ERR "page_83[3]: identifier"
+					" length zero!\n");
+			break;
+		}
+		printk(KERN_INFO "T10 VPD Identifer Length: %d\n", ident_len);
+
+		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
+		if (!vpd) {
+			printk(KERN_ERR "Unable to allocate memory for"
+					" struct t10_vpd\n");
+			goto out;
+		}
+		INIT_LIST_HEAD(&vpd->vpd_list);
+
+		transport_set_vpd_proto_id(vpd, page_83);
+		transport_set_vpd_assoc(vpd, page_83);
+
+		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
+			off += (ident_len + 4);
+			page_len -= (ident_len + 4);
+			kfree(vpd);
+			continue;
+		}
+		if (transport_set_vpd_ident(vpd, page_83) < 0) {
+			off += (ident_len + 4);
+			page_len -= (ident_len + 4);
+			kfree(vpd);
+			continue;
+		}
+
+		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
+		off += (ident_len + 4);
+		page_len -= (ident_len + 4);
+	}
+
+out:
+	kfree(buf);
+}
+
+/*	pscsi_add_device_to_list():
+ *
+ *
+ */
+static struct se_device *pscsi_add_device_to_list(
+	struct se_hba *hba,
+	struct se_subsystem_dev *se_dev,
+	struct pscsi_dev_virt *pdv,
+	struct scsi_device *sd,
+	int dev_flags)
+{
+	struct se_device *dev;
+	struct se_dev_limits dev_limits;
+	struct request_queue *q;
+	struct queue_limits *limits;
+
+	memset(&dev_limits, 0, sizeof(struct se_dev_limits));
+
+	if (!sd->queue_depth) {
+		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
+
+		printk(KERN_ERR "Set broken SCSI Device %d:%d:%d"
+			" queue_depth to %d\n", sd->channel, sd->id,
+				sd->lun, sd->queue_depth);
+	}
+	/*
+	 * Setup the local scope queue_limits from struct request_queue->limits
+	 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
+	 */
+	q = sd->request_queue;
+	limits = &dev_limits.limits;
+	limits->logical_block_size = sd->sector_size;
+	limits->max_hw_sectors = (sd->host->max_sectors > queue_max_hw_sectors(q)) ?
+				  queue_max_hw_sectors(q) : sd->host->max_sectors;
+	limits->max_sectors = (sd->host->max_sectors > queue_max_sectors(q)) ?
+				  queue_max_sectors(q) : sd->host->max_sectors;
+	dev_limits.hw_queue_depth = sd->queue_depth;
+	dev_limits.queue_depth = sd->queue_depth;
+	/*
+	 * Setup our standard INQUIRY info into se_dev->t10_wwn
+	 */
+	pscsi_set_inquiry_info(sd, &se_dev->t10_wwn);
+
+	/*
+	 * Set the pointer pdv->pdv_sd to from passed struct scsi_device,
+	 * which has already been referenced with Linux SCSI code with
+	 * scsi_device_get() in this file's pscsi_create_virtdevice().
+	 *
+	 * The passthrough operations called by the transport_add_device_*
+	 * function below will require this pointer to be set for passthroug
+	 *  ops.
+	 *
+	 * For the shutdown case in pscsi_free_device(), this struct
+	 * scsi_device  reference is released with Linux SCSI code
+	 * scsi_device_put() and the pdv->pdv_sd cleared.
+	 */
+	pdv->pdv_sd = sd;
+
+	dev = transport_add_device_to_core_hba(hba, &pscsi_template,
+				se_dev, dev_flags, (void *)pdv,
+				&dev_limits, NULL, NULL);
+	if (!(dev)) {
+		pdv->pdv_sd = NULL;
+		return NULL;
+	}
+
+	/*
+	 * Locate VPD WWN Information used for various purposes within
+	 * the Storage Engine.
+	 */
+	if (!pscsi_get_inquiry_vpd_serial(sd, &se_dev->t10_wwn)) {
+		/*
+		 * If VPD Unit Serial returned GOOD status, try
+		 * VPD Device Identification page (0x83).
+		 */
+		pscsi_get_inquiry_vpd_device_ident(sd, &se_dev->t10_wwn);
+	}
+
+	/*
+	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
+	 */
+	if (sd->type == TYPE_TAPE)
+		pscsi_tape_read_blocksize(dev, sd);
+	return dev;
+}
+
+static void *pscsi_allocate_virtdevice(struct se_hba *hba, const char *name)
+{
+	struct pscsi_dev_virt *pdv;
+
+	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
+	if (!(pdv)) {
+		printk(KERN_ERR "Unable to allocate memory for struct pscsi_dev_virt\n");
+		return NULL;
+	}
+	pdv->pdv_se_hba = hba;
+
+	printk(KERN_INFO "PSCSI: Allocated pdv: %p for %s\n", pdv, name);
+	return (void *)pdv;
+}
+
+/*
+ * Called with struct Scsi_Host->host_lock called.
+ */
+static struct se_device *pscsi_create_type_disk(
+	struct scsi_device *sd,
+	struct pscsi_dev_virt *pdv,
+	struct se_subsystem_dev *se_dev,
+	struct se_hba *hba)
+{
+	struct se_device *dev;
+	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
+	struct Scsi_Host *sh = sd->host;
+	struct block_device *bd;
+	u32 dev_flags = 0;
+
+	if (scsi_device_get(sd)) {
+		printk(KERN_ERR "scsi_device_get() failed for %d:%d:%d:%d\n",
+			sh->host_no, sd->channel, sd->id, sd->lun);
+		spin_unlock_irq(sh->host_lock);
+		return NULL;
+	}
+	spin_unlock_irq(sh->host_lock);
+	/*
+	 * Claim exclusive struct block_device access to struct scsi_device
+	 * for TYPE_DISK using supplied udev_path
+	 */
+	bd = blkdev_get_by_path(se_dev->se_dev_udev_path,
+				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
+	if (!(bd)) {
+		printk("pSCSI: blkdev_get_by_path() failed\n");
+		scsi_device_put(sd);
+		return NULL;
+	}
+	pdv->pdv_bd = bd;
+
+	dev = pscsi_add_device_to_list(hba, se_dev, pdv, sd, dev_flags);
+	if (!(dev)) {
+		blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
+		scsi_device_put(sd);
+		return NULL;
+	}
+	printk(KERN_INFO "CORE_PSCSI[%d] - Added TYPE_DISK for %d:%d:%d:%d\n",
+		phv->phv_host_id, sh->host_no, sd->channel, sd->id, sd->lun);
+
+	return dev;
+}
+
+/*
+ * Called with struct Scsi_Host->host_lock called.
+ */
+static struct se_device *pscsi_create_type_rom(
+	struct scsi_device *sd,
+	struct pscsi_dev_virt *pdv,
+	struct se_subsystem_dev *se_dev,
+	struct se_hba *hba)
+{
+	struct se_device *dev;
+	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
+	struct Scsi_Host *sh = sd->host;
+	u32 dev_flags = 0;
+
+	if (scsi_device_get(sd)) {
+		printk(KERN_ERR "scsi_device_get() failed for %d:%d:%d:%d\n",
+			sh->host_no, sd->channel, sd->id, sd->lun);
+		spin_unlock_irq(sh->host_lock);
+		return NULL;
+	}
+	spin_unlock_irq(sh->host_lock);
+
+	dev = pscsi_add_device_to_list(hba, se_dev, pdv, sd, dev_flags);
+	if (!(dev)) {
+		scsi_device_put(sd);
+		return NULL;
+	}
+	printk(KERN_INFO "CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%d\n",
+		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
+		sd->channel, sd->id, sd->lun);
+
+	return dev;
+}
+
+/*
+ *Called with struct Scsi_Host->host_lock called.
+ */
+static struct se_device *pscsi_create_type_other(
+	struct scsi_device *sd,
+	struct pscsi_dev_virt *pdv,
+	struct se_subsystem_dev *se_dev,
+	struct se_hba *hba)
+{
+	struct se_device *dev;
+	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
+	struct Scsi_Host *sh = sd->host;
+	u32 dev_flags = 0;
+
+	spin_unlock_irq(sh->host_lock);
+	dev = pscsi_add_device_to_list(hba, se_dev, pdv, sd, dev_flags);
+	if (!(dev))
+		return NULL;
+
+	printk(KERN_INFO "CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%d\n",
+		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
+		sd->channel, sd->id, sd->lun);
+
+	return dev;
+}
+
+static struct se_device *pscsi_create_virtdevice(
+	struct se_hba *hba,
+	struct se_subsystem_dev *se_dev,
+	void *p)
+{
+	struct pscsi_dev_virt *pdv = (struct pscsi_dev_virt *)p;
+	struct se_device *dev;
+	struct scsi_device *sd;
+	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)hba->hba_ptr;
+	struct Scsi_Host *sh = phv->phv_lld_host;
+	int legacy_mode_enable = 0;
+
+	if (!(pdv)) {
+		printk(KERN_ERR "Unable to locate struct pscsi_dev_virt"
+				" parameter\n");
+		return NULL;
+	}
+	/*
+	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
+	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
+	 */
+	if (!(sh)) {
+		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
+			printk(KERN_ERR "pSCSI: Unable to locate struct"
+				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
+			return NULL;
+		}
+		/*
+		 * For the newer PHV_VIRUTAL_HOST_ID struct scsi_device
+		 * reference, we enforce that udev_path has been set
+		 */
+		if (!(se_dev->su_dev_flags & SDF_USING_UDEV_PATH)) {
+			printk(KERN_ERR "pSCSI: udev_path attribute has not"
+				" been set before ENABLE=1\n");
+			return NULL;
+		}
+		/*
+		 * If no scsi_host_id= was passed for PHV_VIRUTAL_HOST_ID,
+		 * use the original TCM hba ID to reference Linux/SCSI Host No
+		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
+		 */
+		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
+			spin_lock(&hba->device_lock);
+			if (!(list_empty(&hba->hba_dev_list))) {
+				printk(KERN_ERR "pSCSI: Unable to set hba_mode"
+					" with active devices\n");
+				spin_unlock(&hba->device_lock);
+				return NULL;
+			}
+			spin_unlock(&hba->device_lock);
+
+			if (pscsi_pmode_enable_hba(hba, 1) != 1)
+				return NULL;
+
+			legacy_mode_enable = 1;
+			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
+			sh = phv->phv_lld_host;
+		} else {
+			sh = pscsi_get_sh(pdv->pdv_host_id);
+			if (!(sh)) {
+				printk(KERN_ERR "pSCSI: Unable to locate"
+					" pdv_host_id: %d\n", pdv->pdv_host_id);
+				return NULL;
+			}
+		}
+	} else {
+		if (phv->phv_mode == PHV_VIRUTAL_HOST_ID) {
+			printk(KERN_ERR "pSCSI: PHV_VIRUTAL_HOST_ID set while"
+				" struct Scsi_Host exists\n");
+			return NULL;
+		}
+	}
+
+	spin_lock_irq(sh->host_lock);
+	list_for_each_entry(sd, &sh->__devices, siblings) {
+		if ((pdv->pdv_channel_id != sd->channel) ||
+		    (pdv->pdv_target_id != sd->id) ||
+		    (pdv->pdv_lun_id != sd->lun))
+			continue;
+		/*
+		 * Functions will release the held struct scsi_host->host_lock
+		 * before calling calling pscsi_add_device_to_list() to register
+		 * struct scsi_device with target_core_mod.
+		 */
+		switch (sd->type) {
+		case TYPE_DISK:
+			dev = pscsi_create_type_disk(sd, pdv, se_dev, hba);
+			break;
+		case TYPE_ROM:
+			dev = pscsi_create_type_rom(sd, pdv, se_dev, hba);
+			break;
+		default:
+			dev = pscsi_create_type_other(sd, pdv, se_dev, hba);
+			break;
+		}
+
+		if (!(dev)) {
+			if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
+				scsi_host_put(sh);
+			else if (legacy_mode_enable) {
+				pscsi_pmode_enable_hba(hba, 0);
+				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
+			}
+			pdv->pdv_sd = NULL;
+			return NULL;
+		}
+		return dev;
+	}
+	spin_unlock_irq(sh->host_lock);
+
+	printk(KERN_ERR "pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
+		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
+
+	if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
+		scsi_host_put(sh);
+	else if (legacy_mode_enable) {
+		pscsi_pmode_enable_hba(hba, 0);
+		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
+	}
+
+	return NULL;
+}
+
+/*	pscsi_free_device(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static void pscsi_free_device(void *p)
+{
+	struct pscsi_dev_virt *pdv = p;
+	struct pscsi_hba_virt *phv = pdv->pdv_se_hba->hba_ptr;
+	struct scsi_device *sd = pdv->pdv_sd;
+
+	if (sd) {
+		/*
+		 * Release exclusive pSCSI internal struct block_device claim for
+		 * struct scsi_device with TYPE_DISK from pscsi_create_type_disk()
+		 */
+		if ((sd->type == TYPE_DISK) && pdv->pdv_bd) {
+			blkdev_put(pdv->pdv_bd,
+				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
+			pdv->pdv_bd = NULL;
+		}
+		/*
+		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
+		 * to struct Scsi_Host now.
+		 */
+		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
+		    (phv->phv_lld_host != NULL))
+			scsi_host_put(phv->phv_lld_host);
+
+		if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
+			scsi_device_put(sd);
+
+		pdv->pdv_sd = NULL;
+	}
+
+	kfree(pdv);
+}
+
+static inline struct pscsi_plugin_task *PSCSI_TASK(struct se_task *task)
+{
+	return container_of(task, struct pscsi_plugin_task, pscsi_task);
+}
+
+
+/*	pscsi_transport_complete():
+ *
+ *
+ */
+static int pscsi_transport_complete(struct se_task *task)
+{
+	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
+	struct scsi_device *sd = pdv->pdv_sd;
+	int result;
+	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
+	unsigned char *cdb = &pt->pscsi_cdb[0];
+
+	result = pt->pscsi_result;
+	/*
+	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
+	 * forced.
+	 */
+	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
+	     (status_byte(result) << 1) == SAM_STAT_GOOD) {
+		if (!TASK_CMD(task)->se_deve)
+			goto after_mode_sense;
+
+		if (TASK_CMD(task)->se_deve->lun_flags &
+				TRANSPORT_LUNFLAGS_READ_ONLY) {
+			unsigned char *buf = (unsigned char *)
+				T_TASK(task->task_se_cmd)->t_task_buf;
+
+			if (cdb[0] == MODE_SENSE_10) {
+				if (!(buf[3] & 0x80))
+					buf[3] |= 0x80;
+			} else {
+				if (!(buf[2] & 0x80))
+					buf[2] |= 0x80;
+			}
+		}
+	}
+after_mode_sense:
+
+	if (sd->type != TYPE_TAPE)
+		goto after_mode_select;
+
+	/*
+	 * Hack to correctly obtain the initiator requested blocksize for
+	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
+	 * struct scsi_device->sector_size will not contain the correct value
+	 * by default, so we go ahead and set it so
+	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
+	 * storage engine.
+	 */
+	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
+	      (status_byte(result) << 1) == SAM_STAT_GOOD) {
+		unsigned char *buf;
+		struct scatterlist *sg = task->task_sg;
+		u16 bdl;
+		u32 blocksize;
+
+		buf = sg_virt(&sg[0]);
+		if (!(buf)) {
+			printk(KERN_ERR "Unable to get buf for scatterlist\n");
+			goto after_mode_select;
+		}
+
+		if (cdb[0] == MODE_SELECT)
+			bdl = (buf[3]);
+		else
+			bdl = (buf[6] << 8) | (buf[7]);
+
+		if (!bdl)
+			goto after_mode_select;
+
+		if (cdb[0] == MODE_SELECT)
+			blocksize = (buf[9] << 16) | (buf[10] << 8) |
+					(buf[11]);
+		else
+			blocksize = (buf[13] << 16) | (buf[14] << 8) |
+					(buf[15]);
+
+		sd->sector_size = blocksize;
+	}
+after_mode_select:
+
+	if (status_byte(result) & CHECK_CONDITION)
+		return 1;
+
+	return 0;
+}
+
+static struct se_task *
+pscsi_alloc_task(struct se_cmd *cmd)
+{
+	struct pscsi_plugin_task *pt;
+	unsigned char *cdb = T_TASK(cmd)->t_task_cdb;
+
+	pt = kzalloc(sizeof(struct pscsi_plugin_task), GFP_KERNEL);
+	if (!pt) {
+		printk(KERN_ERR "Unable to allocate struct pscsi_plugin_task\n");
+		return NULL;
+	}
+
+	/*
+	 * If TCM Core is signaling a > TCM_MAX_COMMAND_SIZE allocation,
+	 * allocate the extended CDB buffer for per struct se_task context
+	 * pt->pscsi_cdb now.
+	 */
+	if (T_TASK(cmd)->t_task_cdb != T_TASK(cmd)->__t_task_cdb) {
+
+		pt->pscsi_cdb = kzalloc(scsi_command_size(cdb), GFP_KERNEL);
+		if (!(pt->pscsi_cdb)) {
+			printk(KERN_ERR "pSCSI: Unable to allocate extended"
+					" pt->pscsi_cdb\n");
+			return NULL;
+		}
+	} else
+		pt->pscsi_cdb = &pt->__pscsi_cdb[0];
+
+	return &pt->pscsi_task;
+}
+
+static inline void pscsi_blk_init_request(
+	struct se_task *task,
+	struct pscsi_plugin_task *pt,
+	struct request *req,
+	int bidi_read)
+{
+	/*
+	 * Defined as "scsi command" in include/linux/blkdev.h.
+	 */
+	req->cmd_type = REQ_TYPE_BLOCK_PC;
+	/*
+	 * For the extra BIDI-COMMAND READ struct request we do not
+	 * need to setup the remaining structure members
+	 */
+	if (bidi_read)
+		return;
+	/*
+	 * Setup the done function pointer for struct request,
+	 * also set the end_io_data pointer.to struct se_task.
+	 */
+	req->end_io = pscsi_req_done;
+	req->end_io_data = (void *)task;
+	/*
+	 * Load the referenced struct se_task's SCSI CDB into
+	 * include/linux/blkdev.h:struct request->cmd
+	 */
+	req->cmd_len = scsi_command_size(pt->pscsi_cdb);
+	req->cmd = &pt->pscsi_cdb[0];
+	/*
+	 * Setup pointer for outgoing sense data.
+	 */
+	req->sense = (void *)&pt->pscsi_sense[0];
+	req->sense_len = 0;
+}
+
+/*
+ * Used for pSCSI data payloads for all *NON* SCF_SCSI_DATA_SG_IO_CDB
+*/
+static int pscsi_blk_get_request(struct se_task *task)
+{
+	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
+	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
+
+	pt->pscsi_req = blk_get_request(pdv->pdv_sd->request_queue,
+			(task->task_data_direction == DMA_TO_DEVICE),
+			GFP_KERNEL);
+	if (!(pt->pscsi_req) || IS_ERR(pt->pscsi_req)) {
+		printk(KERN_ERR "PSCSI: blk_get_request() failed: %ld\n",
+				IS_ERR(pt->pscsi_req));
+		return PYX_TRANSPORT_LU_COMM_FAILURE;
+	}
+	/*
+	 * Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
+	 * and setup rq callback, CDB and sense.
+	 */
+	pscsi_blk_init_request(task, pt, pt->pscsi_req, 0);
+	return 0;
+}
+
+/*      pscsi_do_task(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static int pscsi_do_task(struct se_task *task)
+{
+	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
+	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
+	/*
+	 * Set the struct request->timeout value based on peripheral
+	 * device type from SCSI.
+	 */
+	if (pdv->pdv_sd->type == TYPE_DISK)
+		pt->pscsi_req->timeout = PS_TIMEOUT_DISK;
+	else
+		pt->pscsi_req->timeout = PS_TIMEOUT_OTHER;
+
+	pt->pscsi_req->retries = PS_RETRY;
+	/*
+	 * Queue the struct request into the struct scsi_device->request_queue.
+	 * Also check for HEAD_OF_QUEUE SAM TASK attr from received se_cmd
+	 * descriptor
+	 */
+	blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, pt->pscsi_req,
+			(task->task_se_cmd->sam_task_attr == TASK_ATTR_HOQ),
+			pscsi_req_done);
+
+	return PYX_TRANSPORT_SENT_TO_TRANSPORT;
+}
+
+static void pscsi_free_task(struct se_task *task)
+{
+	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
+	struct se_cmd *cmd = task->task_se_cmd;
+
+	/*
+	 * Release the extended CDB allocation from pscsi_alloc_task()
+	 * if one exists.
+	 */
+	if (T_TASK(cmd)->t_task_cdb != T_TASK(cmd)->__t_task_cdb)
+		kfree(pt->pscsi_cdb);
+	/*
+	 * We do not release the bio(s) here associated with this task, as
+	 * this is handled by bio_put() and pscsi_bi_endio().
+	 */
+	kfree(pt);
+}
+
+enum {
+	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
+	Opt_scsi_lun_id, Opt_err
+};
+
+static match_table_t tokens = {
+	{Opt_scsi_host_id, "scsi_host_id=%d"},
+	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
+	{Opt_scsi_target_id, "scsi_target_id=%d"},
+	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
+	{Opt_err, NULL}
+};
+
+static ssize_t pscsi_set_configfs_dev_params(struct se_hba *hba,
+	struct se_subsystem_dev *se_dev,
+	const char *page,
+	ssize_t count)
+{
+	struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;
+	struct pscsi_hba_virt *phv = hba->hba_ptr;
+	char *orig, *ptr, *opts;
+	substring_t args[MAX_OPT_ARGS];
+	int ret = 0, arg, token;
+
+	opts = kstrdup(page, GFP_KERNEL);
+	if (!opts)
+		return -ENOMEM;
+
+	orig = opts;
+
+	while ((ptr = strsep(&opts, ",")) != NULL) {
+		if (!*ptr)
+			continue;
+
+		token = match_token(ptr, tokens, args);
+		switch (token) {
+		case Opt_scsi_host_id:
+			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
+				printk(KERN_ERR "PSCSI[%d]: Unable to accept"
+					" scsi_host_id while phv_mode =="
+					" PHV_LLD_SCSI_HOST_NO\n",
+					phv->phv_host_id);
+				ret = -EINVAL;
+				goto out;
+			}
+			match_int(args, &arg);
+			pdv->pdv_host_id = arg;
+			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Host ID:"
+				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
+			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
+			break;
+		case Opt_scsi_channel_id:
+			match_int(args, &arg);
+			pdv->pdv_channel_id = arg;
+			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Channel"
+				" ID: %d\n",  phv->phv_host_id,
+				pdv->pdv_channel_id);
+			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
+			break;
+		case Opt_scsi_target_id:
+			match_int(args, &arg);
+			pdv->pdv_target_id = arg;
+			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Target"
+				" ID: %d\n", phv->phv_host_id,
+				pdv->pdv_target_id);
+			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
+			break;
+		case Opt_scsi_lun_id:
+			match_int(args, &arg);
+			pdv->pdv_lun_id = arg;
+			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI LUN ID:"
+				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
+			pdv->pdv_flags |= PDF_HAS_LUN_ID;
+			break;
+		default:
+			break;
+		}
+	}
+
+out:
+	kfree(orig);
+	return (!ret) ? count : ret;
+}
+
+static ssize_t pscsi_check_configfs_dev_params(
+	struct se_hba *hba,
+	struct se_subsystem_dev *se_dev)
+{
+	struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;
+
+	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
+	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
+	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
+		printk(KERN_ERR "Missing scsi_channel_id=, scsi_target_id= and"
+			" scsi_lun_id= parameters\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+static ssize_t pscsi_show_configfs_dev_params(struct se_hba *hba,
+					      struct se_subsystem_dev *se_dev,
+					      char *b)
+{
+	struct pscsi_hba_virt *phv = hba->hba_ptr;
+        struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;
+	struct scsi_device *sd = pdv->pdv_sd;
+	unsigned char host_id[16];
+	ssize_t bl;
+	int i;
+
+	if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
+		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
+	else
+		snprintf(host_id, 16, "PHBA Mode");
+
+	bl = sprintf(b, "SCSI Device Bus Location:"
+		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
+		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
+		host_id);
+
+	if (sd) {
+		bl += sprintf(b + bl, "        ");
+		bl += sprintf(b + bl, "Vendor: ");
+		for (i = 0; i < 8; i++) {
+			if (ISPRINT(sd->vendor[i]))   /* printable character? */
+				bl += sprintf(b + bl, "%c", sd->vendor[i]);
+			else
+				bl += sprintf(b + bl, " ");
+		}
+		bl += sprintf(b + bl, " Model: ");
+		for (i = 0; i < 16; i++) {
+			if (ISPRINT(sd->model[i]))   /* printable character ? */
+				bl += sprintf(b + bl, "%c", sd->model[i]);
+			else
+				bl += sprintf(b + bl, " ");
+		}
+		bl += sprintf(b + bl, " Rev: ");
+		for (i = 0; i < 4; i++) {
+			if (ISPRINT(sd->rev[i]))   /* printable character ? */
+				bl += sprintf(b + bl, "%c", sd->rev[i]);
+			else
+				bl += sprintf(b + bl, " ");
+		}
+		bl += sprintf(b + bl, "\n");
+	}
+	return bl;
+}
+
+static void pscsi_bi_endio(struct bio *bio, int error)
+{
+	bio_put(bio);
+}
+
+static inline struct bio *pscsi_get_bio(struct pscsi_dev_virt *pdv, int sg_num)
+{
+	struct bio *bio;
+	/*
+	 * Use bio_malloc() following the comment in for bio -> struct request
+	 * in block/blk-core.c:blk_make_request()
+	 */
+	bio = bio_kmalloc(GFP_KERNEL, sg_num);
+	if (!(bio)) {
+		printk(KERN_ERR "PSCSI: bio_kmalloc() failed\n");
+		return NULL;
+	}
+	bio->bi_end_io = pscsi_bi_endio;
+
+	return bio;
+}
+
+#if 0
+#define DEBUG_PSCSI(x...) printk(x)
+#else
+#define DEBUG_PSCSI(x...)
+#endif
+
+static int __pscsi_map_task_SG(
+	struct se_task *task,
+	struct scatterlist *task_sg,
+	u32 task_sg_num,
+	int bidi_read)
+{
+	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
+	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
+	struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
+	struct page *page;
+	struct scatterlist *sg;
+	u32 data_len = task->task_size, i, len, bytes, off;
+	int nr_pages = (task->task_size + task_sg[0].offset +
+			PAGE_SIZE - 1) >> PAGE_SHIFT;
+	int nr_vecs = 0, rc, ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
+	int rw = (task->task_data_direction == DMA_TO_DEVICE);
+
+	if (!task->task_size)
+		return 0;
+	/*
+	 * For SCF_SCSI_DATA_SG_IO_CDB, Use fs/bio.c:bio_add_page() to setup
+	 * the bio_vec maplist from TC< struct se_mem -> task->task_sg ->
+	 * struct scatterlist memory.  The struct se_task->task_sg[] currently needs
+	 * to be attached to struct bios for submission to Linux/SCSI using
+	 * struct request to struct scsi_device->request_queue.
+	 *
+	 * Note that this will be changing post v2.6.28 as Target_Core_Mod/pSCSI
+	 * is ported to upstream SCSI passthrough functionality that accepts
+	 * struct scatterlist->page_link or struct page as a paraemeter.
+	 */
+	DEBUG_PSCSI("PSCSI: nr_pages: %d\n", nr_pages);
+
+	for_each_sg(task_sg, sg, task_sg_num, i) {
+		page = sg_page(sg);
+		off = sg->offset;
+		len = sg->length;
+
+		DEBUG_PSCSI("PSCSI: i: %d page: %p len: %d off: %d\n", i,
+			page, len, off);
+
+		while (len > 0 && data_len > 0) {
+			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
+			bytes = min(bytes, data_len);
+
+			if (!(bio)) {
+				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
+				nr_pages -= nr_vecs;
+				/*
+				 * Calls bio_kmalloc() and sets bio->bi_end_io()
+				 */
+				bio = pscsi_get_bio(pdv, nr_vecs);
+				if (!(bio))
+					goto fail;
+
+				if (rw)
+					bio->bi_rw |= REQ_WRITE;
+
+				DEBUG_PSCSI("PSCSI: Allocated bio: %p,"
+					" dir: %s nr_vecs: %d\n", bio,
+					(rw) ? "rw" : "r", nr_vecs);
+				/*
+				 * Set *hbio pointer to handle the case:
+				 * nr_pages > BIO_MAX_PAGES, where additional
+				 * bios need to be added to complete a given
+				 * struct se_task
+				 */
+				if (!hbio)
+					hbio = tbio = bio;
+				else
+					tbio = tbio->bi_next = bio;
+			}
+
+			DEBUG_PSCSI("PSCSI: Calling bio_add_pc_page() i: %d"
+				" bio: %p page: %p len: %d off: %d\n", i, bio,
+				page, len, off);
+
+			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
+					bio, page, bytes, off);
+			if (rc != bytes)
+				goto fail;
+
+			DEBUG_PSCSI("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
+				bio->bi_vcnt, nr_vecs);
+
+			if (bio->bi_vcnt > nr_vecs) {
+				DEBUG_PSCSI("PSCSI: Reached bio->bi_vcnt max:"
+					" %d i: %d bio: %p, allocating another"
+					" bio\n", bio->bi_vcnt, i, bio);
+				/*
+				 * Clear the pointer so that another bio will
+				 * be allocated with pscsi_get_bio() above, the
+				 * current bio has already been set *tbio and
+				 * bio->bi_next.
+				 */
+				bio = NULL;
+			}
+
+			page++;
+			len -= bytes;
+			data_len -= bytes;
+			off = 0;
+		}
+	}
+	/*
+	 * Setup the primary pt->pscsi_req used for non BIDI and BIDI-COMMAND
+	 * primary SCSI WRITE poayload mapped for struct se_task->task_sg[]
+	 */
+	if (!(bidi_read)) {
+		/*
+		 * Starting with v2.6.31, call blk_make_request() passing in *hbio to
+		 * allocate the pSCSI task a struct request.
+		 */
+		pt->pscsi_req = blk_make_request(pdv->pdv_sd->request_queue,
+					hbio, GFP_KERNEL);
+		if (!(pt->pscsi_req)) {
+			printk(KERN_ERR "pSCSI: blk_make_request() failed\n");
+			goto fail;
+		}
+		/*
+		 * Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
+		 * and setup rq callback, CDB and sense.
+		 */
+		pscsi_blk_init_request(task, pt, pt->pscsi_req, 0);
+
+		return task->task_sg_num;
+	}
+	/*
+	 * Setup the secondary pt->pscsi_req->next_rq used for the extra BIDI-COMMAND
+	 * SCSI READ paylaod mapped for struct se_task->task_sg_bidi[]
+	 */
+	pt->pscsi_req->next_rq = blk_make_request(pdv->pdv_sd->request_queue,
+					hbio, GFP_KERNEL);
+	if (!(pt->pscsi_req->next_rq)) {
+		printk(KERN_ERR "pSCSI: blk_make_request() failed for BIDI\n");
+		goto fail;
+	}
+	pscsi_blk_init_request(task, pt, pt->pscsi_req->next_rq, 1);
+
+	return task->task_sg_num;
+fail:
+	while (hbio) {
+		bio = hbio;
+		hbio = hbio->bi_next;
+		bio->bi_next = NULL;
+		bio_endio(bio, 0);
+	}
+	return ret;
+}
+
+static int pscsi_map_task_SG(struct se_task *task)
+{
+	int ret;
+
+	/*
+	 * Setup the main struct request for the task->task_sg[] payload
+	 */
+
+	ret = __pscsi_map_task_SG(task, task->task_sg, task->task_sg_num, 0);
+	if (ret >= 0 && task->task_sg_bidi) {
+		/*
+		 * If present, set up the extra BIDI-COMMAND SCSI READ
+		 * struct request and payload.
+		 */
+		ret = __pscsi_map_task_SG(task, task->task_sg_bidi,
+					task->task_sg_num, 1);
+	}
+
+	if (ret < 0)
+		return PYX_TRANSPORT_LU_COMM_FAILURE;
+	return 0;
+}
+
+/*	pscsi_map_task_non_SG():
+ *
+ *
+ */
+static int pscsi_map_task_non_SG(struct se_task *task)
+{
+	struct se_cmd *cmd = TASK_CMD(task);
+	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
+	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
+	int ret = 0;
+
+	if (pscsi_blk_get_request(task) < 0)
+		return PYX_TRANSPORT_LU_COMM_FAILURE;
+
+	if (!task->task_size)
+		return 0;
+
+	ret = blk_rq_map_kern(pdv->pdv_sd->request_queue,
+			pt->pscsi_req, T_TASK(cmd)->t_task_buf,
+			task->task_size, GFP_KERNEL);
+	if (ret < 0) {
+		printk(KERN_ERR "PSCSI: blk_rq_map_kern() failed: %d\n", ret);
+		return PYX_TRANSPORT_LU_COMM_FAILURE;
+	}
+	return 0;
+}
+
+static int pscsi_CDB_none(struct se_task *task)
+{
+	return pscsi_blk_get_request(task);
+}
+
+/*	pscsi_get_cdb():
+ *
+ *
+ */
+static unsigned char *pscsi_get_cdb(struct se_task *task)
+{
+	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
+
+	return pt->pscsi_cdb;
+}
+
+/*	pscsi_get_sense_buffer():
+ *
+ *
+ */
+static unsigned char *pscsi_get_sense_buffer(struct se_task *task)
+{
+	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
+
+	return (unsigned char *)&pt->pscsi_sense[0];
+}
+
+/*	pscsi_get_device_rev():
+ *
+ *
+ */
+static u32 pscsi_get_device_rev(struct se_device *dev)
+{
+	struct pscsi_dev_virt *pdv = dev->dev_ptr;
+	struct scsi_device *sd = pdv->pdv_sd;
+
+	return (sd->scsi_level - 1) ? sd->scsi_level - 1 : 1;
+}
+
+/*	pscsi_get_device_type():
+ *
+ *
+ */
+static u32 pscsi_get_device_type(struct se_device *dev)
+{
+	struct pscsi_dev_virt *pdv = dev->dev_ptr;
+	struct scsi_device *sd = pdv->pdv_sd;
+
+	return sd->type;
+}
+
+static sector_t pscsi_get_blocks(struct se_device *dev)
+{
+	struct pscsi_dev_virt *pdv = dev->dev_ptr;
+
+	if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
+		return pdv->pdv_bd->bd_part->nr_sects;
+
+	dump_stack();
+	return 0;
+}
+
+/*	pscsi_handle_SAM_STATUS_failures():
+ *
+ *
+ */
+static inline void pscsi_process_SAM_status(
+	struct se_task *task,
+	struct pscsi_plugin_task *pt)
+{
+	task->task_scsi_status = status_byte(pt->pscsi_result);
+	if ((task->task_scsi_status)) {
+		task->task_scsi_status <<= 1;
+		printk(KERN_INFO "PSCSI Status Byte exception at task: %p CDB:"
+			" 0x%02x Result: 0x%08x\n", task, pt->pscsi_cdb[0],
+			pt->pscsi_result);
+	}
+
+	switch (host_byte(pt->pscsi_result)) {
+	case DID_OK:
+		transport_complete_task(task, (!task->task_scsi_status));
+		break;
+	default:
+		printk(KERN_INFO "PSCSI Host Byte exception at task: %p CDB:"
+			" 0x%02x Result: 0x%08x\n", task, pt->pscsi_cdb[0],
+			pt->pscsi_result);
+		task->task_scsi_status = SAM_STAT_CHECK_CONDITION;
+		task->task_error_status = PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
+		TASK_CMD(task)->transport_error_status =
+					PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
+		transport_complete_task(task, 0);
+		break;
+	}
+
+	return;
+}
+
+static void pscsi_req_done(struct request *req, int uptodate)
+{
+	struct se_task *task = req->end_io_data;
+	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
+
+	pt->pscsi_result = req->errors;
+	pt->pscsi_resid = req->resid_len;
+
+	pscsi_process_SAM_status(task, pt);
+	/*
+	 * Release BIDI-READ if present
+	 */
+	if (req->next_rq != NULL)
+		__blk_put_request(req->q, req->next_rq);
+
+	__blk_put_request(req->q, req);
+	pt->pscsi_req = NULL;
+}
+
+static struct se_subsystem_api pscsi_template = {
+	.name			= "pscsi",
+	.owner			= THIS_MODULE,
+	.transport_type		= TRANSPORT_PLUGIN_PHBA_PDEV,
+	.cdb_none		= pscsi_CDB_none,
+	.map_task_non_SG	= pscsi_map_task_non_SG,
+	.map_task_SG		= pscsi_map_task_SG,
+	.attach_hba		= pscsi_attach_hba,
+	.detach_hba		= pscsi_detach_hba,
+	.pmode_enable_hba	= pscsi_pmode_enable_hba,
+	.allocate_virtdevice	= pscsi_allocate_virtdevice,
+	.create_virtdevice	= pscsi_create_virtdevice,
+	.free_device		= pscsi_free_device,
+	.transport_complete	= pscsi_transport_complete,
+	.alloc_task		= pscsi_alloc_task,
+	.do_task		= pscsi_do_task,
+	.free_task		= pscsi_free_task,
+	.check_configfs_dev_params = pscsi_check_configfs_dev_params,
+	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
+	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
+	.get_cdb		= pscsi_get_cdb,
+	.get_sense_buffer	= pscsi_get_sense_buffer,
+	.get_device_rev		= pscsi_get_device_rev,
+	.get_device_type	= pscsi_get_device_type,
+	.get_blocks		= pscsi_get_blocks,
+};
+
+static int __init pscsi_module_init(void)
+{
+	return transport_subsystem_register(&pscsi_template);
+}
+
+static void pscsi_module_exit(void)
+{
+	transport_subsystem_release(&pscsi_template);
+}
+
+MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
+MODULE_AUTHOR("nab@Linux-iSCSI.org");
+MODULE_LICENSE("GPL");
+
+module_init(pscsi_module_init);
+module_exit(pscsi_module_exit);