Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2434 insertions, 0 deletions

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
new file mode 100644
index 000000000..29fcc44be
--- /dev/null
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -0,0 +1,2434 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* ------------------------------------------------------------
+ * ibmvscsi.c
+ * (C) Copyright IBM Corporation 1994, 2004
+ * Authors: Colin DeVilbiss (devilbis@us.ibm.com)
+ *          Santiago Leon (santil@us.ibm.com)
+ *          Dave Boutcher (sleddog@us.ibm.com)
+ *
+ * ------------------------------------------------------------
+ * Emulation of a SCSI host adapter for Virtual I/O devices
+ *
+ * This driver supports the SCSI adapter implemented by the IBM
+ * Power5 firmware.  That SCSI adapter is not a physical adapter,
+ * but allows Linux SCSI peripheral drivers to directly
+ * access devices in another logical partition on the physical system.
+ *
+ * The virtual adapter(s) are present in the open firmware device
+ * tree just like real adapters.
+ *
+ * One of the capabilities provided on these systems is the ability
+ * to DMA between partitions.  The architecture states that for VSCSI,
+ * the server side is allowed to DMA to and from the client.  The client
+ * is never trusted to DMA to or from the server directly.
+ *
+ * Messages are sent between partitions on a "Command/Response Queue" 
+ * (CRQ), which is just a buffer of 16 byte entries in the receiver's 
+ * Senders cannot access the buffer directly, but send messages by
+ * making a hypervisor call and passing in the 16 bytes.  The hypervisor
+ * puts the message in the next 16 byte space in round-robin fashion,
+ * turns on the high order bit of the message (the valid bit), and 
+ * generates an interrupt to the receiver (if interrupts are turned on.) 
+ * The receiver just turns off the valid bit when they have copied out
+ * the message.
+ *
+ * The VSCSI client builds a SCSI Remote Protocol (SRP) Information Unit
+ * (IU) (as defined in the T10 standard available at www.t10.org), gets 
+ * a DMA address for the message, and sends it to the server as the
+ * payload of a CRQ message.  The server DMAs the SRP IU and processes it,
+ * including doing any additional data transfers.  When it is done, it
+ * DMAs the SRP response back to the same address as the request came from,
+ * and sends a CRQ message back to inform the client that the request has
+ * completed.
+ *
+ * TODO: This is currently pretty tied to the IBM pSeries hypervisor
+ * interfaces.  It would be really nice to abstract this above an RDMA
+ * layer.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/kthread.h>
+#include <asm/firmware.h>
+#include <asm/vio.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_transport_srp.h>
+#include "ibmvscsi.h"
+
+/* The values below are somewhat arbitrary default values, but 
+ * OS/400 will use 3 busses (disks, CDs, tapes, I think.)
+ * Note that there are 3 bits of channel value, 6 bits of id, and
+ * 5 bits of LUN.
+ */
+static int max_id = 64;
+static int max_channel = 3;
+static int init_timeout = 300;
+static int login_timeout = 60;
+static int info_timeout = 30;
+static int abort_timeout = 60;
+static int reset_timeout = 60;
+static int max_requests = IBMVSCSI_MAX_REQUESTS_DEFAULT;
+static int max_events = IBMVSCSI_MAX_REQUESTS_DEFAULT + 2;
+static int fast_fail = 1;
+static int client_reserve = 1;
+static char partition_name[96] = "UNKNOWN";
+static unsigned int partition_number = -1;
+static LIST_HEAD(ibmvscsi_head);
+static DEFINE_SPINLOCK(ibmvscsi_driver_lock);
+
+static struct scsi_transport_template *ibmvscsi_transport_template;
+
+#define IBMVSCSI_VERSION "1.5.9"
+
+MODULE_DESCRIPTION("IBM Virtual SCSI");
+MODULE_AUTHOR("Dave Boutcher");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(IBMVSCSI_VERSION);
+
+module_param_named(max_id, max_id, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(max_id, "Largest ID value for each channel [Default=64]");
+module_param_named(max_channel, max_channel, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(max_channel, "Largest channel value [Default=3]");
+module_param_named(init_timeout, init_timeout, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds");
+module_param_named(max_requests, max_requests, int, S_IRUGO);
+MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter");
+module_param_named(fast_fail, fast_fail, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(fast_fail, "Enable fast fail. [Default=1]");
+module_param_named(client_reserve, client_reserve, int, S_IRUGO );
+MODULE_PARM_DESC(client_reserve, "Attempt client managed reserve/release");
+
+static void ibmvscsi_handle_crq(struct viosrp_crq *crq,
+				struct ibmvscsi_host_data *hostdata);
+
+/* ------------------------------------------------------------
+ * Routines for managing the command/response queue
+ */
+/**
+ * ibmvscsi_handle_event: - Interrupt handler for crq events
+ * @irq:	number of irq to handle, not used
+ * @dev_instance: ibmvscsi_host_data of host that received interrupt
+ *
+ * Disables interrupts and schedules srp_task
+ * Always returns IRQ_HANDLED
+ */
+static irqreturn_t ibmvscsi_handle_event(int irq, void *dev_instance)
+{
+	struct ibmvscsi_host_data *hostdata =
+	    (struct ibmvscsi_host_data *)dev_instance;
+	vio_disable_interrupts(to_vio_dev(hostdata->dev));
+	tasklet_schedule(&hostdata->srp_task);
+	return IRQ_HANDLED;
+}
+
+/**
+ * release_crq_queue: - Deallocates data and unregisters CRQ
+ * @queue:	crq_queue to initialize and register
+ * @host_data:	ibmvscsi_host_data of host
+ *
+ * Frees irq, deallocates a page for messages, unmaps dma, and unregisters
+ * the crq with the hypervisor.
+ */
+static void ibmvscsi_release_crq_queue(struct crq_queue *queue,
+				       struct ibmvscsi_host_data *hostdata,
+				       int max_requests)
+{
+	long rc = 0;
+	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
+	free_irq(vdev->irq, (void *)hostdata);
+	tasklet_kill(&hostdata->srp_task);
+	do {
+		if (rc)
+			msleep(100);
+		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
+	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
+	dma_unmap_single(hostdata->dev,
+			 queue->msg_token,
+			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
+	free_page((unsigned long)queue->msgs);
+}
+
+/**
+ * crq_queue_next_crq: - Returns the next entry in message queue
+ * @queue:	crq_queue to use
+ *
+ * Returns pointer to next entry in queue, or NULL if there are no new
+ * entried in the CRQ.
+ */
+static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
+{
+	struct viosrp_crq *crq;
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue->lock, flags);
+	crq = &queue->msgs[queue->cur];
+	if (crq->valid != VIOSRP_CRQ_FREE) {
+		if (++queue->cur == queue->size)
+			queue->cur = 0;
+
+		/* Ensure the read of the valid bit occurs before reading any
+		 * other bits of the CRQ entry
+		 */
+		rmb();
+	} else
+		crq = NULL;
+	spin_unlock_irqrestore(&queue->lock, flags);
+
+	return crq;
+}
+
+/**
+ * ibmvscsi_send_crq: - Send a CRQ
+ * @hostdata:	the adapter
+ * @word1:	the first 64 bits of the data
+ * @word2:	the second 64 bits of the data
+ */
+static int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata,
+			     u64 word1, u64 word2)
+{
+	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
+
+	/*
+	 * Ensure the command buffer is flushed to memory before handing it
+	 * over to the VIOS to prevent it from fetching any stale data.
+	 */
+	mb();
+	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
+}
+
+/**
+ * ibmvscsi_task: - Process srps asynchronously
+ * @data:	ibmvscsi_host_data of host
+ */
+static void ibmvscsi_task(void *data)
+{
+	struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
+	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
+	struct viosrp_crq *crq;
+	int done = 0;
+
+	while (!done) {
+		/* Pull all the valid messages off the CRQ */
+		while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
+			ibmvscsi_handle_crq(crq, hostdata);
+			crq->valid = VIOSRP_CRQ_FREE;
+			wmb();
+		}
+
+		vio_enable_interrupts(vdev);
+		crq = crq_queue_next_crq(&hostdata->queue);
+		if (crq != NULL) {
+			vio_disable_interrupts(vdev);
+			ibmvscsi_handle_crq(crq, hostdata);
+			crq->valid = VIOSRP_CRQ_FREE;
+			wmb();
+		} else {
+			done = 1;
+		}
+	}
+}
+
+static void gather_partition_info(void)
+{
+	const char *ppartition_name;
+	const __be32 *p_number_ptr;
+
+	/* Retrieve information about this partition */
+	if (!of_root)
+		return;
+
+	of_node_get(of_root);
+
+	ppartition_name = of_get_property(of_root, "ibm,partition-name", NULL);
+	if (ppartition_name)
+		strlcpy(partition_name, ppartition_name,
+				sizeof(partition_name));
+	p_number_ptr = of_get_property(of_root, "ibm,partition-no", NULL);
+	if (p_number_ptr)
+		partition_number = of_read_number(p_number_ptr, 1);
+	of_node_put(of_root);
+}
+
+static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
+{
+	memset(&hostdata->madapter_info, 0x00,
+			sizeof(hostdata->madapter_info));
+
+	dev_info(hostdata->dev, "SRP_VERSION: %s\n", SRP_VERSION);
+	strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
+
+	strncpy(hostdata->madapter_info.partition_name, partition_name,
+			sizeof(hostdata->madapter_info.partition_name));
+
+	hostdata->madapter_info.partition_number =
+					cpu_to_be32(partition_number);
+
+	hostdata->madapter_info.mad_version = cpu_to_be32(SRP_MAD_VERSION_1);
+	hostdata->madapter_info.os_type = cpu_to_be32(SRP_MAD_OS_LINUX);
+}
+
+/**
+ * reset_crq_queue: - resets a crq after a failure
+ * @queue:	crq_queue to initialize and register
+ * @hostdata:	ibmvscsi_host_data of host
+ *
+ */
+static int ibmvscsi_reset_crq_queue(struct crq_queue *queue,
+				    struct ibmvscsi_host_data *hostdata)
+{
+	int rc = 0;
+	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
+
+	/* Close the CRQ */
+	do {
+		if (rc)
+			msleep(100);
+		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
+	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
+
+	/* Clean out the queue */
+	memset(queue->msgs, 0x00, PAGE_SIZE);
+	queue->cur = 0;
+
+	set_adapter_info(hostdata);
+
+	/* And re-open it again */
+	rc = plpar_hcall_norets(H_REG_CRQ,
+				vdev->unit_address,
+				queue->msg_token, PAGE_SIZE);
+	if (rc == H_CLOSED) {
+		/* Adapter is good, but other end is not ready */
+		dev_warn(hostdata->dev, "Partner adapter not ready\n");
+	} else if (rc != 0) {
+		dev_warn(hostdata->dev, "couldn't register crq--rc 0x%x\n", rc);
+	}
+	return rc;
+}
+
+/**
+ * initialize_crq_queue: - Initializes and registers CRQ with hypervisor
+ * @queue:	crq_queue to initialize and register
+ * @hostdata:	ibmvscsi_host_data of host
+ *
+ * Allocates a page for messages, maps it for dma, and registers
+ * the crq with the hypervisor.
+ * Returns zero on success.
+ */
+static int ibmvscsi_init_crq_queue(struct crq_queue *queue,
+				   struct ibmvscsi_host_data *hostdata,
+				   int max_requests)
+{
+	int rc;
+	int retrc;
+	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
+
+	queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
+
+	if (!queue->msgs)
+		goto malloc_failed;
+	queue->size = PAGE_SIZE / sizeof(*queue->msgs);
+
+	queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
+					  queue->size * sizeof(*queue->msgs),
+					  DMA_BIDIRECTIONAL);
+
+	if (dma_mapping_error(hostdata->dev, queue->msg_token))
+		goto map_failed;
+
+	gather_partition_info();
+	set_adapter_info(hostdata);
+
+	retrc = rc = plpar_hcall_norets(H_REG_CRQ,
+				vdev->unit_address,
+				queue->msg_token, PAGE_SIZE);
+	if (rc == H_RESOURCE)
+		/* maybe kexecing and resource is busy. try a reset */
+		rc = ibmvscsi_reset_crq_queue(queue,
+					      hostdata);
+
+	if (rc == H_CLOSED) {
+		/* Adapter is good, but other end is not ready */
+		dev_warn(hostdata->dev, "Partner adapter not ready\n");
+		retrc = 0;
+	} else if (rc != 0) {
+		dev_warn(hostdata->dev, "Error %d opening adapter\n", rc);
+		goto reg_crq_failed;
+	}
+
+	queue->cur = 0;
+	spin_lock_init(&queue->lock);
+
+	tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
+		     (unsigned long)hostdata);
+
+	if (request_irq(vdev->irq,
+			ibmvscsi_handle_event,
+			0, "ibmvscsi", (void *)hostdata) != 0) {
+		dev_err(hostdata->dev, "couldn't register irq 0x%x\n",
+			vdev->irq);
+		goto req_irq_failed;
+	}
+
+	rc = vio_enable_interrupts(vdev);
+	if (rc != 0) {
+		dev_err(hostdata->dev, "Error %d enabling interrupts!!!\n", rc);
+		goto req_irq_failed;
+	}
+
+	return retrc;
+
+      req_irq_failed:
+	tasklet_kill(&hostdata->srp_task);
+	rc = 0;
+	do {
+		if (rc)
+			msleep(100);
+		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
+	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
+      reg_crq_failed:
+	dma_unmap_single(hostdata->dev,
+			 queue->msg_token,
+			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
+      map_failed:
+	free_page((unsigned long)queue->msgs);
+      malloc_failed:
+	return -1;
+}
+
+/**
+ * reenable_crq_queue: - reenables a crq after
+ * @queue:	crq_queue to initialize and register
+ * @hostdata:	ibmvscsi_host_data of host
+ *
+ */
+static int ibmvscsi_reenable_crq_queue(struct crq_queue *queue,
+				       struct ibmvscsi_host_data *hostdata)
+{
+	int rc = 0;
+	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
+
+	set_adapter_info(hostdata);
+
+	/* Re-enable the CRQ */
+	do {
+		if (rc)
+			msleep(100);
+		rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
+	} while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
+
+	if (rc)
+		dev_err(hostdata->dev, "Error %d enabling adapter\n", rc);
+	return rc;
+}
+
+/* ------------------------------------------------------------
+ * Routines for the event pool and event structs
+ */
+/**
+ * initialize_event_pool: - Allocates and initializes the event pool for a host
+ * @pool:	event_pool to be initialized
+ * @size:	Number of events in pool
+ * @hostdata:	ibmvscsi_host_data who owns the event pool
+ *
+ * Returns zero on success.
+*/
+static int initialize_event_pool(struct event_pool *pool,
+				 int size, struct ibmvscsi_host_data *hostdata)
+{
+	int i;
+
+	pool->size = size;
+	pool->next = 0;
+	pool->events = kcalloc(pool->size, sizeof(*pool->events), GFP_KERNEL);
+	if (!pool->events)
+		return -ENOMEM;
+
+	pool->iu_storage =
+	    dma_alloc_coherent(hostdata->dev,
+			       pool->size * sizeof(*pool->iu_storage),
+			       &pool->iu_token, 0);
+	if (!pool->iu_storage) {
+		kfree(pool->events);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < pool->size; ++i) {
+		struct srp_event_struct *evt = &pool->events[i];
+		memset(&evt->crq, 0x00, sizeof(evt->crq));
+		atomic_set(&evt->free, 1);
+		evt->crq.valid = VIOSRP_CRQ_CMD_RSP;
+		evt->crq.IU_length = cpu_to_be16(sizeof(*evt->xfer_iu));
+		evt->crq.IU_data_ptr = cpu_to_be64(pool->iu_token +
+			sizeof(*evt->xfer_iu) * i);
+		evt->xfer_iu = pool->iu_storage + i;
+		evt->hostdata = hostdata;
+		evt->ext_list = NULL;
+		evt->ext_list_token = 0;
+	}
+
+	return 0;
+}
+
+/**
+ * release_event_pool: - Frees memory of an event pool of a host
+ * @pool:	event_pool to be released
+ * @hostdata:	ibmvscsi_host_data who owns the even pool
+ *
+ * Returns zero on success.
+*/
+static void release_event_pool(struct event_pool *pool,
+			       struct ibmvscsi_host_data *hostdata)
+{
+	int i, in_use = 0;
+	for (i = 0; i < pool->size; ++i) {
+		if (atomic_read(&pool->events[i].free) != 1)
+			++in_use;
+		if (pool->events[i].ext_list) {
+			dma_free_coherent(hostdata->dev,
+				  SG_ALL * sizeof(struct srp_direct_buf),
+				  pool->events[i].ext_list,
+				  pool->events[i].ext_list_token);
+		}
+	}
+	if (in_use)
+		dev_warn(hostdata->dev, "releasing event pool with %d "
+			 "events still in use?\n", in_use);
+	kfree(pool->events);
+	dma_free_coherent(hostdata->dev,
+			  pool->size * sizeof(*pool->iu_storage),
+			  pool->iu_storage, pool->iu_token);
+}
+
+/**
+ * valid_event_struct: - Determines if event is valid.
+ * @pool:	event_pool that contains the event
+ * @evt:	srp_event_struct to be checked for validity
+ *
+ * Returns zero if event is invalid, one otherwise.
+*/
+static int valid_event_struct(struct event_pool *pool,
+				struct srp_event_struct *evt)
+{
+	int index = evt - pool->events;
+	if (index < 0 || index >= pool->size)	/* outside of bounds */
+		return 0;
+	if (evt != pool->events + index)	/* unaligned */
+		return 0;
+	return 1;
+}
+
+/**
+ * ibmvscsi_free-event_struct: - Changes status of event to "free"
+ * @pool:	event_pool that contains the event
+ * @evt:	srp_event_struct to be modified
+ *
+*/
+static void free_event_struct(struct event_pool *pool,
+				       struct srp_event_struct *evt)
+{
+	if (!valid_event_struct(pool, evt)) {
+		dev_err(evt->hostdata->dev, "Freeing invalid event_struct %p "
+			"(not in pool %p)\n", evt, pool->events);
+		return;
+	}
+	if (atomic_inc_return(&evt->free) != 1) {
+		dev_err(evt->hostdata->dev, "Freeing event_struct %p "
+			"which is not in use!\n", evt);
+		return;
+	}
+}
+
+/**
+ * get_evt_struct: - Gets the next free event in pool
+ * @pool:	event_pool that contains the events to be searched
+ *
+ * Returns the next event in "free" state, and NULL if none are free.
+ * Note that no synchronization is done here, we assume the host_lock
+ * will syncrhonze things.
+*/
+static struct srp_event_struct *get_event_struct(struct event_pool *pool)
+{
+	int i;
+	int poolsize = pool->size;
+	int offset = pool->next;
+
+	for (i = 0; i < poolsize; i++) {
+		offset = (offset + 1) % poolsize;
+		if (!atomic_dec_if_positive(&pool->events[offset].free)) {
+			pool->next = offset;
+			return &pool->events[offset];
+		}
+	}
+
+	printk(KERN_ERR "ibmvscsi: found no event struct in pool!\n");
+	return NULL;
+}
+
+/**
+ * init_event_struct: Initialize fields in an event struct that are always 
+ *                    required.
+ * @evt:        The event
+ * @done:       Routine to call when the event is responded to
+ * @format:     SRP or MAD format
+ * @timeout:    timeout value set in the CRQ
+ */
+static void init_event_struct(struct srp_event_struct *evt_struct,
+			      void (*done) (struct srp_event_struct *),
+			      u8 format,
+			      int timeout)
+{
+	evt_struct->cmnd = NULL;
+	evt_struct->cmnd_done = NULL;
+	evt_struct->sync_srp = NULL;
+	evt_struct->crq.format = format;
+	evt_struct->crq.timeout = cpu_to_be16(timeout);
+	evt_struct->done = done;
+}
+
+/* ------------------------------------------------------------
+ * Routines for receiving SCSI responses from the hosting partition
+ */
+
+/**
+ * set_srp_direction: Set the fields in the srp related to data
+ *     direction and number of buffers based on the direction in
+ *     the scsi_cmnd and the number of buffers
+ */
+static void set_srp_direction(struct scsi_cmnd *cmd,
+			      struct srp_cmd *srp_cmd, 
+			      int numbuf)
+{
+	u8 fmt;
+
+	if (numbuf == 0)
+		return;
+	
+	if (numbuf == 1)
+		fmt = SRP_DATA_DESC_DIRECT;
+	else {
+		fmt = SRP_DATA_DESC_INDIRECT;
+		numbuf = min(numbuf, MAX_INDIRECT_BUFS);
+
+		if (cmd->sc_data_direction == DMA_TO_DEVICE)
+			srp_cmd->data_out_desc_cnt = numbuf;
+		else
+			srp_cmd->data_in_desc_cnt = numbuf;
+	}
+
+	if (cmd->sc_data_direction == DMA_TO_DEVICE)
+		srp_cmd->buf_fmt = fmt << 4;
+	else
+		srp_cmd->buf_fmt = fmt;
+}
+
+/**
+ * unmap_cmd_data: - Unmap data pointed in srp_cmd based on the format
+ * @cmd:	srp_cmd whose additional_data member will be unmapped
+ * @dev:	device for which the memory is mapped
+ *
+*/
+static void unmap_cmd_data(struct srp_cmd *cmd,
+			   struct srp_event_struct *evt_struct,
+			   struct device *dev)
+{
+	u8 out_fmt, in_fmt;
+
+	out_fmt = cmd->buf_fmt >> 4;
+	in_fmt = cmd->buf_fmt & ((1U << 4) - 1);
+
+	if (out_fmt == SRP_NO_DATA_DESC && in_fmt == SRP_NO_DATA_DESC)
+		return;
+
+	if (evt_struct->cmnd)
+		scsi_dma_unmap(evt_struct->cmnd);
+}
+
+static int map_sg_list(struct scsi_cmnd *cmd, int nseg,
+		       struct srp_direct_buf *md)
+{
+	int i;
+	struct scatterlist *sg;
+	u64 total_length = 0;
+
+	scsi_for_each_sg(cmd, sg, nseg, i) {
+		struct srp_direct_buf *descr = md + i;
+		descr->va = cpu_to_be64(sg_dma_address(sg));
+		descr->len = cpu_to_be32(sg_dma_len(sg));
+		descr->key = 0;
+		total_length += sg_dma_len(sg);
+ 	}
+	return total_length;
+}
+
+/**
+ * map_sg_data: - Maps dma for a scatterlist and initializes descriptor fields
+ * @cmd:	struct scsi_cmnd with the scatterlist
+ * @srp_cmd:	srp_cmd that contains the memory descriptor
+ * @dev:	device for which to map dma memory
+ *
+ * Called by map_data_for_srp_cmd() when building srp cmd from scsi cmd.
+ * Returns 1 on success.
+*/
+static int map_sg_data(struct scsi_cmnd *cmd,
+		       struct srp_event_struct *evt_struct,
+		       struct srp_cmd *srp_cmd, struct device *dev)
+{
+
+	int sg_mapped;
+	u64 total_length = 0;
+	struct srp_direct_buf *data =
+		(struct srp_direct_buf *) srp_cmd->add_data;
+	struct srp_indirect_buf *indirect =
+		(struct srp_indirect_buf *) data;
+
+	sg_mapped = scsi_dma_map(cmd);
+	if (!sg_mapped)
+		return 1;
+	else if (sg_mapped < 0)
+		return 0;
+
+	set_srp_direction(cmd, srp_cmd, sg_mapped);
+
+	/* special case; we can use a single direct descriptor */
+	if (sg_mapped == 1) {
+		map_sg_list(cmd, sg_mapped, data);
+		return 1;
+	}
+
+	indirect->table_desc.va = 0;
+	indirect->table_desc.len = cpu_to_be32(sg_mapped *
+					       sizeof(struct srp_direct_buf));
+	indirect->table_desc.key = 0;
+
+	if (sg_mapped <= MAX_INDIRECT_BUFS) {
+		total_length = map_sg_list(cmd, sg_mapped,
+					   &indirect->desc_list[0]);
+		indirect->len = cpu_to_be32(total_length);
+		return 1;
+	}
+
+	/* get indirect table */
+	if (!evt_struct->ext_list) {
+		evt_struct->ext_list = (struct srp_direct_buf *)
+			dma_alloc_coherent(dev,
+					   SG_ALL * sizeof(struct srp_direct_buf),
+					   &evt_struct->ext_list_token, 0);
+		if (!evt_struct->ext_list) {
+			if (!firmware_has_feature(FW_FEATURE_CMO))
+				sdev_printk(KERN_ERR, cmd->device,
+				            "Can't allocate memory "
+				            "for indirect table\n");
+			scsi_dma_unmap(cmd);
+			return 0;
+		}
+	}
+
+	total_length = map_sg_list(cmd, sg_mapped, evt_struct->ext_list);
+
+	indirect->len = cpu_to_be32(total_length);
+	indirect->table_desc.va = cpu_to_be64(evt_struct->ext_list_token);
+	indirect->table_desc.len = cpu_to_be32(sg_mapped *
+					       sizeof(indirect->desc_list[0]));
+	memcpy(indirect->desc_list, evt_struct->ext_list,
+	       MAX_INDIRECT_BUFS * sizeof(struct srp_direct_buf));
+ 	return 1;
+}
+
+/**
+ * map_data_for_srp_cmd: - Calls functions to map data for srp cmds
+ * @cmd:	struct scsi_cmnd with the memory to be mapped
+ * @srp_cmd:	srp_cmd that contains the memory descriptor
+ * @dev:	dma device for which to map dma memory
+ *
+ * Called by scsi_cmd_to_srp_cmd() when converting scsi cmds to srp cmds 
+ * Returns 1 on success.
+*/
+static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
+				struct srp_event_struct *evt_struct,
+				struct srp_cmd *srp_cmd, struct device *dev)
+{
+	switch (cmd->sc_data_direction) {
+	case DMA_FROM_DEVICE:
+	case DMA_TO_DEVICE:
+		break;
+	case DMA_NONE:
+		return 1;
+	case DMA_BIDIRECTIONAL:
+		sdev_printk(KERN_ERR, cmd->device,
+			    "Can't map DMA_BIDIRECTIONAL to read/write\n");
+		return 0;
+	default:
+		sdev_printk(KERN_ERR, cmd->device,
+			    "Unknown data direction 0x%02x; can't map!\n",
+			    cmd->sc_data_direction);
+		return 0;
+	}
+
+	return map_sg_data(cmd, evt_struct, srp_cmd, dev);
+}
+
+/**
+ * purge_requests: Our virtual adapter just shut down.  purge any sent requests
+ * @hostdata:    the adapter
+ */
+static void purge_requests(struct ibmvscsi_host_data *hostdata, int error_code)
+{
+	struct srp_event_struct *evt;
+	unsigned long flags;
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	while (!list_empty(&hostdata->sent)) {
+		evt = list_first_entry(&hostdata->sent, struct srp_event_struct, list);
+		list_del(&evt->list);
+		del_timer(&evt->timer);
+
+		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+		if (evt->cmnd) {
+			evt->cmnd->result = (error_code << 16);
+			unmap_cmd_data(&evt->iu.srp.cmd, evt,
+				       evt->hostdata->dev);
+			if (evt->cmnd_done)
+				evt->cmnd_done(evt->cmnd);
+		} else if (evt->done && evt->crq.format != VIOSRP_MAD_FORMAT &&
+			   evt->iu.srp.login_req.opcode != SRP_LOGIN_REQ)
+			evt->done(evt);
+		free_event_struct(&evt->hostdata->pool, evt);
+		spin_lock_irqsave(hostdata->host->host_lock, flags);
+	}
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+}
+
+/**
+ * ibmvscsi_set_request_limit - Set the adapter request_limit in response to
+ * an adapter failure, reset, or SRP Login. Done under host lock to prevent
+ * race with SCSI command submission.
+ * @hostdata:	adapter to adjust
+ * @limit:	new request limit
+ */
+static void ibmvscsi_set_request_limit(struct ibmvscsi_host_data *hostdata, int limit)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	atomic_set(&hostdata->request_limit, limit);
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+}
+
+/**
+ * ibmvscsi_reset_host - Reset the connection to the server
+ * @hostdata:	struct ibmvscsi_host_data to reset
+*/
+static void ibmvscsi_reset_host(struct ibmvscsi_host_data *hostdata)
+{
+	scsi_block_requests(hostdata->host);
+	ibmvscsi_set_request_limit(hostdata, 0);
+
+	purge_requests(hostdata, DID_ERROR);
+	hostdata->action = IBMVSCSI_HOST_ACTION_RESET;
+	wake_up(&hostdata->work_wait_q);
+}
+
+/**
+ * ibmvscsi_timeout - Internal command timeout handler
+ * @evt_struct:	struct srp_event_struct that timed out
+ *
+ * Called when an internally generated command times out
+*/
+static void ibmvscsi_timeout(struct timer_list *t)
+{
+	struct srp_event_struct *evt_struct = from_timer(evt_struct, t, timer);
+	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
+
+	dev_err(hostdata->dev, "Command timed out (%x). Resetting connection\n",
+		evt_struct->iu.srp.cmd.opcode);
+
+	ibmvscsi_reset_host(hostdata);
+}
+
+
+/* ------------------------------------------------------------
+ * Routines for sending and receiving SRPs
+ */
+/**
+ * ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()
+ * @evt_struct:	evt_struct to be sent
+ * @hostdata:	ibmvscsi_host_data of host
+ * @timeout:	timeout in seconds - 0 means do not time command
+ *
+ * Returns the value returned from ibmvscsi_send_crq(). (Zero for success)
+ * Note that this routine assumes that host_lock is held for synchronization
+*/
+static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
+				   struct ibmvscsi_host_data *hostdata,
+				   unsigned long timeout)
+{
+	__be64 *crq_as_u64 = (__be64 *)&evt_struct->crq;
+	int request_status = 0;
+	int rc;
+	int srp_req = 0;
+
+	/* If we have exhausted our request limit, just fail this request,
+	 * unless it is for a reset or abort.
+	 * Note that there are rare cases involving driver generated requests 
+	 * (such as task management requests) that the mid layer may think we
+	 * can handle more requests (can_queue) when we actually can't
+	 */
+	if (evt_struct->crq.format == VIOSRP_SRP_FORMAT) {
+		srp_req = 1;
+		request_status =
+			atomic_dec_if_positive(&hostdata->request_limit);
+		/* If request limit was -1 when we started, it is now even
+		 * less than that
+		 */
+		if (request_status < -1)
+			goto send_error;
+		/* Otherwise, we may have run out of requests. */
+		/* If request limit was 0 when we started the adapter is in the
+		 * process of performing a login with the server adapter, or
+		 * we may have run out of requests.
+		 */
+		else if (request_status == -1 &&
+		         evt_struct->iu.srp.login_req.opcode != SRP_LOGIN_REQ)
+			goto send_busy;
+		/* Abort and reset calls should make it through.
+		 * Nothing except abort and reset should use the last two
+		 * slots unless we had two or less to begin with.
+		 */
+		else if (request_status < 2 &&
+		         evt_struct->iu.srp.cmd.opcode != SRP_TSK_MGMT) {
+			/* In the case that we have less than two requests
+			 * available, check the server limit as a combination
+			 * of the request limit and the number of requests
+			 * in-flight (the size of the send list).  If the
+			 * server limit is greater than 2, return busy so
+			 * that the last two are reserved for reset and abort.
+			 */
+			int server_limit = request_status;
+			struct srp_event_struct *tmp_evt;
+
+			list_for_each_entry(tmp_evt, &hostdata->sent, list) {
+				server_limit++;
+			}
+
+			if (server_limit > 2)
+				goto send_busy;
+		}
+	}
+
+	/* Copy the IU into the transfer area */
+	*evt_struct->xfer_iu = evt_struct->iu;
+	evt_struct->xfer_iu->srp.rsp.tag = (u64)evt_struct;
+
+	/* Add this to the sent list.  We need to do this 
+	 * before we actually send 
+	 * in case it comes back REALLY fast
+	 */
+	list_add_tail(&evt_struct->list, &hostdata->sent);
+
+	timer_setup(&evt_struct->timer, ibmvscsi_timeout, 0);
+	if (timeout) {
+		evt_struct->timer.expires = jiffies + (timeout * HZ);
+		add_timer(&evt_struct->timer);
+	}
+
+	rc = ibmvscsi_send_crq(hostdata, be64_to_cpu(crq_as_u64[0]),
+			       be64_to_cpu(crq_as_u64[1]));
+	if (rc != 0) {
+		list_del(&evt_struct->list);
+		del_timer(&evt_struct->timer);
+
+		/* If send_crq returns H_CLOSED, return SCSI_MLQUEUE_HOST_BUSY.
+		 * Firmware will send a CRQ with a transport event (0xFF) to
+		 * tell this client what has happened to the transport.  This
+		 * will be handled in ibmvscsi_handle_crq()
+		 */
+		if (rc == H_CLOSED) {
+			dev_warn(hostdata->dev, "send warning. "
+			         "Receive queue closed, will retry.\n");
+			goto send_busy;
+		}
+		dev_err(hostdata->dev, "send error %d\n", rc);
+		if (srp_req)
+			atomic_inc(&hostdata->request_limit);
+		goto send_error;
+	}
+
+	return 0;
+
+ send_busy:
+	unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
+
+	free_event_struct(&hostdata->pool, evt_struct);
+	if (srp_req && request_status != -1)
+		atomic_inc(&hostdata->request_limit);
+	return SCSI_MLQUEUE_HOST_BUSY;
+
+ send_error:
+	unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
+
+	if (evt_struct->cmnd != NULL) {
+		evt_struct->cmnd->result = DID_ERROR << 16;
+		evt_struct->cmnd_done(evt_struct->cmnd);
+	} else if (evt_struct->done)
+		evt_struct->done(evt_struct);
+
+	free_event_struct(&hostdata->pool, evt_struct);
+	return 0;
+}
+
+/**
+ * handle_cmd_rsp: -  Handle responses from commands
+ * @evt_struct:	srp_event_struct to be handled
+ *
+ * Used as a callback by when sending scsi cmds.
+ * Gets called by ibmvscsi_handle_crq()
+*/
+static void handle_cmd_rsp(struct srp_event_struct *evt_struct)
+{
+	struct srp_rsp *rsp = &evt_struct->xfer_iu->srp.rsp;
+	struct scsi_cmnd *cmnd = evt_struct->cmnd;
+
+	if (unlikely(rsp->opcode != SRP_RSP)) {
+		if (printk_ratelimit())
+			dev_warn(evt_struct->hostdata->dev,
+				 "bad SRP RSP type %#02x\n", rsp->opcode);
+	}
+	
+	if (cmnd) {
+		cmnd->result |= rsp->status;
+		if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
+			memcpy(cmnd->sense_buffer,
+			       rsp->data,
+			       be32_to_cpu(rsp->sense_data_len));
+		unmap_cmd_data(&evt_struct->iu.srp.cmd, 
+			       evt_struct, 
+			       evt_struct->hostdata->dev);
+
+		if (rsp->flags & SRP_RSP_FLAG_DOOVER)
+			scsi_set_resid(cmnd,
+				       be32_to_cpu(rsp->data_out_res_cnt));
+		else if (rsp->flags & SRP_RSP_FLAG_DIOVER)
+			scsi_set_resid(cmnd, be32_to_cpu(rsp->data_in_res_cnt));
+	}
+
+	if (evt_struct->cmnd_done)
+		evt_struct->cmnd_done(cmnd);
+}
+
+/**
+ * lun_from_dev: - Returns the lun of the scsi device
+ * @dev:	struct scsi_device
+ *
+*/
+static inline u16 lun_from_dev(struct scsi_device *dev)
+{
+	return (0x2 << 14) | (dev->id << 8) | (dev->channel << 5) | dev->lun;
+}
+
+/**
+ * ibmvscsi_queue: - The queuecommand function of the scsi template 
+ * @cmd:	struct scsi_cmnd to be executed
+ * @done:	Callback function to be called when cmd is completed
+*/
+static int ibmvscsi_queuecommand_lck(struct scsi_cmnd *cmnd,
+				 void (*done) (struct scsi_cmnd *))
+{
+	struct srp_cmd *srp_cmd;
+	struct srp_event_struct *evt_struct;
+	struct srp_indirect_buf *indirect;
+	struct ibmvscsi_host_data *hostdata = shost_priv(cmnd->device->host);
+	u16 lun = lun_from_dev(cmnd->device);
+	u8 out_fmt, in_fmt;
+
+	cmnd->result = (DID_OK << 16);
+	evt_struct = get_event_struct(&hostdata->pool);
+	if (!evt_struct)
+		return SCSI_MLQUEUE_HOST_BUSY;
+
+	/* Set up the actual SRP IU */
+	srp_cmd = &evt_struct->iu.srp.cmd;
+	memset(srp_cmd, 0x00, SRP_MAX_IU_LEN);
+	srp_cmd->opcode = SRP_CMD;
+	memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(srp_cmd->cdb));
+	int_to_scsilun(lun, &srp_cmd->lun);
+
+	if (!map_data_for_srp_cmd(cmnd, evt_struct, srp_cmd, hostdata->dev)) {
+		if (!firmware_has_feature(FW_FEATURE_CMO))
+			sdev_printk(KERN_ERR, cmnd->device,
+			            "couldn't convert cmd to srp_cmd\n");
+		free_event_struct(&hostdata->pool, evt_struct);
+		return SCSI_MLQUEUE_HOST_BUSY;
+	}
+
+	init_event_struct(evt_struct,
+			  handle_cmd_rsp,
+			  VIOSRP_SRP_FORMAT,
+			  cmnd->request->timeout/HZ);
+
+	evt_struct->cmnd = cmnd;
+	evt_struct->cmnd_done = done;
+
+	/* Fix up dma address of the buffer itself */
+	indirect = (struct srp_indirect_buf *) srp_cmd->add_data;
+	out_fmt = srp_cmd->buf_fmt >> 4;
+	in_fmt = srp_cmd->buf_fmt & ((1U << 4) - 1);
+	if ((in_fmt == SRP_DATA_DESC_INDIRECT ||
+	     out_fmt == SRP_DATA_DESC_INDIRECT) &&
+	    indirect->table_desc.va == 0) {
+		indirect->table_desc.va =
+			cpu_to_be64(be64_to_cpu(evt_struct->crq.IU_data_ptr) +
+			offsetof(struct srp_cmd, add_data) +
+			offsetof(struct srp_indirect_buf, desc_list));
+	}
+
+	return ibmvscsi_send_srp_event(evt_struct, hostdata, 0);
+}
+
+static DEF_SCSI_QCMD(ibmvscsi_queuecommand)
+
+/* ------------------------------------------------------------
+ * Routines for driver initialization
+ */
+
+/**
+ * map_persist_bufs: - Pre-map persistent data for adapter logins
+ * @hostdata:   ibmvscsi_host_data of host
+ *
+ * Map the capabilities and adapter info DMA buffers to avoid runtime failures.
+ * Return 1 on error, 0 on success.
+ */
+static int map_persist_bufs(struct ibmvscsi_host_data *hostdata)
+{
+
+	hostdata->caps_addr = dma_map_single(hostdata->dev, &hostdata->caps,
+					     sizeof(hostdata->caps), DMA_BIDIRECTIONAL);
+
+	if (dma_mapping_error(hostdata->dev, hostdata->caps_addr)) {
+		dev_err(hostdata->dev, "Unable to map capabilities buffer!\n");
+		return 1;
+	}
+
+	hostdata->adapter_info_addr = dma_map_single(hostdata->dev,
+						     &hostdata->madapter_info,
+						     sizeof(hostdata->madapter_info),
+						     DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(hostdata->dev, hostdata->adapter_info_addr)) {
+		dev_err(hostdata->dev, "Unable to map adapter info buffer!\n");
+		dma_unmap_single(hostdata->dev, hostdata->caps_addr,
+				 sizeof(hostdata->caps), DMA_BIDIRECTIONAL);
+		return 1;
+	}
+
+	return 0;
+}
+
+/**
+ * unmap_persist_bufs: - Unmap persistent data needed for adapter logins
+ * @hostdata:   ibmvscsi_host_data of host
+ *
+ * Unmap the capabilities and adapter info DMA buffers
+ */
+static void unmap_persist_bufs(struct ibmvscsi_host_data *hostdata)
+{
+	dma_unmap_single(hostdata->dev, hostdata->caps_addr,
+			 sizeof(hostdata->caps), DMA_BIDIRECTIONAL);
+
+	dma_unmap_single(hostdata->dev, hostdata->adapter_info_addr,
+			 sizeof(hostdata->madapter_info), DMA_BIDIRECTIONAL);
+}
+
+/**
+ * login_rsp: - Handle response to SRP login request
+ * @evt_struct:	srp_event_struct with the response
+ *
+ * Used as a "done" callback by when sending srp_login. Gets called
+ * by ibmvscsi_handle_crq()
+*/
+static void login_rsp(struct srp_event_struct *evt_struct)
+{
+	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
+	switch (evt_struct->xfer_iu->srp.login_rsp.opcode) {
+	case SRP_LOGIN_RSP:	/* it worked! */
+		break;
+	case SRP_LOGIN_REJ:	/* refused! */
+		dev_info(hostdata->dev, "SRP_LOGIN_REJ reason %u\n",
+			 evt_struct->xfer_iu->srp.login_rej.reason);
+		/* Login failed.  */
+		ibmvscsi_set_request_limit(hostdata, -1);
+		return;
+	default:
+		dev_err(hostdata->dev, "Invalid login response typecode 0x%02x!\n",
+			evt_struct->xfer_iu->srp.login_rsp.opcode);
+		/* Login failed.  */
+		ibmvscsi_set_request_limit(hostdata, -1);
+		return;
+	}
+
+	dev_info(hostdata->dev, "SRP_LOGIN succeeded\n");
+	hostdata->client_migrated = 0;
+
+	/* Now we know what the real request-limit is.
+	 * This value is set rather than added to request_limit because
+	 * request_limit could have been set to -1 by this client.
+	 */
+	ibmvscsi_set_request_limit(hostdata,
+		   be32_to_cpu(evt_struct->xfer_iu->srp.login_rsp.req_lim_delta));
+
+	/* If we had any pending I/Os, kick them */
+	hostdata->action = IBMVSCSI_HOST_ACTION_UNBLOCK;
+	wake_up(&hostdata->work_wait_q);
+}
+
+/**
+ * send_srp_login: - Sends the srp login
+ * @hostdata:	ibmvscsi_host_data of host
+ *
+ * Returns zero if successful.
+*/
+static int send_srp_login(struct ibmvscsi_host_data *hostdata)
+{
+	int rc;
+	unsigned long flags;
+	struct srp_login_req *login;
+	struct srp_event_struct *evt_struct = get_event_struct(&hostdata->pool);
+
+	BUG_ON(!evt_struct);
+	init_event_struct(evt_struct, login_rsp,
+			  VIOSRP_SRP_FORMAT, login_timeout);
+
+	login = &evt_struct->iu.srp.login_req;
+	memset(login, 0, sizeof(*login));
+	login->opcode = SRP_LOGIN_REQ;
+	login->req_it_iu_len = cpu_to_be32(sizeof(union srp_iu));
+	login->req_buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
+					 SRP_BUF_FORMAT_INDIRECT);
+
+	/* Start out with a request limit of 0, since this is negotiated in
+	 * the login request we are just sending and login requests always
+	 * get sent by the driver regardless of request_limit.
+	 */
+	ibmvscsi_set_request_limit(hostdata, 0);
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, login_timeout * 2);
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+	dev_info(hostdata->dev, "sent SRP login\n");
+	return rc;
+};
+
+/**
+ * capabilities_rsp: - Handle response to MAD adapter capabilities request
+ * @evt_struct:	srp_event_struct with the response
+ *
+ * Used as a "done" callback by when sending adapter_info.
+ */
+static void capabilities_rsp(struct srp_event_struct *evt_struct)
+{
+	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
+
+	if (evt_struct->xfer_iu->mad.capabilities.common.status) {
+		dev_err(hostdata->dev, "error 0x%X getting capabilities info\n",
+			evt_struct->xfer_iu->mad.capabilities.common.status);
+	} else {
+		if (hostdata->caps.migration.common.server_support !=
+		    cpu_to_be16(SERVER_SUPPORTS_CAP))
+			dev_info(hostdata->dev, "Partition migration not supported\n");
+
+		if (client_reserve) {
+			if (hostdata->caps.reserve.common.server_support ==
+			    cpu_to_be16(SERVER_SUPPORTS_CAP))
+				dev_info(hostdata->dev, "Client reserve enabled\n");
+			else
+				dev_info(hostdata->dev, "Client reserve not supported\n");
+		}
+	}
+
+	send_srp_login(hostdata);
+}
+
+/**
+ * send_mad_capabilities: - Sends the mad capabilities request
+ *      and stores the result so it can be retrieved with
+ * @hostdata:	ibmvscsi_host_data of host
+ */
+static void send_mad_capabilities(struct ibmvscsi_host_data *hostdata)
+{
+	struct viosrp_capabilities *req;
+	struct srp_event_struct *evt_struct;
+	unsigned long flags;
+	struct device_node *of_node = hostdata->dev->of_node;
+	const char *location;
+
+	evt_struct = get_event_struct(&hostdata->pool);
+	BUG_ON(!evt_struct);
+
+	init_event_struct(evt_struct, capabilities_rsp,
+			  VIOSRP_MAD_FORMAT, info_timeout);
+
+	req = &evt_struct->iu.mad.capabilities;
+	memset(req, 0, sizeof(*req));
+
+	hostdata->caps.flags = cpu_to_be32(CAP_LIST_SUPPORTED);
+	if (hostdata->client_migrated)
+		hostdata->caps.flags |= cpu_to_be32(CLIENT_MIGRATED);
+
+	strlcpy(hostdata->caps.name, dev_name(&hostdata->host->shost_gendev),
+		sizeof(hostdata->caps.name));
+
+	location = of_get_property(of_node, "ibm,loc-code", NULL);
+	location = location ? location : dev_name(hostdata->dev);
+	strlcpy(hostdata->caps.loc, location, sizeof(hostdata->caps.loc));
+
+	req->common.type = cpu_to_be32(VIOSRP_CAPABILITIES_TYPE);
+	req->buffer = cpu_to_be64(hostdata->caps_addr);
+
+	hostdata->caps.migration.common.cap_type =
+				cpu_to_be32(MIGRATION_CAPABILITIES);
+	hostdata->caps.migration.common.length =
+				cpu_to_be16(sizeof(hostdata->caps.migration));
+	hostdata->caps.migration.common.server_support =
+				cpu_to_be16(SERVER_SUPPORTS_CAP);
+	hostdata->caps.migration.ecl = cpu_to_be32(1);
+
+	if (client_reserve) {
+		hostdata->caps.reserve.common.cap_type =
+					cpu_to_be32(RESERVATION_CAPABILITIES);
+		hostdata->caps.reserve.common.length =
+				cpu_to_be16(sizeof(hostdata->caps.reserve));
+		hostdata->caps.reserve.common.server_support =
+				cpu_to_be16(SERVER_SUPPORTS_CAP);
+		hostdata->caps.reserve.type =
+				cpu_to_be32(CLIENT_RESERVE_SCSI_2);
+		req->common.length =
+				cpu_to_be16(sizeof(hostdata->caps));
+	} else
+		req->common.length = cpu_to_be16(sizeof(hostdata->caps) -
+						sizeof(hostdata->caps.reserve));
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	if (ibmvscsi_send_srp_event(evt_struct, hostdata, info_timeout * 2))
+		dev_err(hostdata->dev, "couldn't send CAPABILITIES_REQ!\n");
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+};
+
+/**
+ * fast_fail_rsp: - Handle response to MAD enable fast fail
+ * @evt_struct:	srp_event_struct with the response
+ *
+ * Used as a "done" callback by when sending enable fast fail. Gets called
+ * by ibmvscsi_handle_crq()
+ */
+static void fast_fail_rsp(struct srp_event_struct *evt_struct)
+{
+	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
+	u16 status = be16_to_cpu(evt_struct->xfer_iu->mad.fast_fail.common.status);
+
+	if (status == VIOSRP_MAD_NOT_SUPPORTED)
+		dev_err(hostdata->dev, "fast_fail not supported in server\n");
+	else if (status == VIOSRP_MAD_FAILED)
+		dev_err(hostdata->dev, "fast_fail request failed\n");
+	else if (status != VIOSRP_MAD_SUCCESS)
+		dev_err(hostdata->dev, "error 0x%X enabling fast_fail\n", status);
+
+	send_mad_capabilities(hostdata);
+}
+
+/**
+ * init_host - Start host initialization
+ * @hostdata:	ibmvscsi_host_data of host
+ *
+ * Returns zero if successful.
+ */
+static int enable_fast_fail(struct ibmvscsi_host_data *hostdata)
+{
+	int rc;
+	unsigned long flags;
+	struct viosrp_fast_fail *fast_fail_mad;
+	struct srp_event_struct *evt_struct;
+
+	if (!fast_fail) {
+		send_mad_capabilities(hostdata);
+		return 0;
+	}
+
+	evt_struct = get_event_struct(&hostdata->pool);
+	BUG_ON(!evt_struct);
+
+	init_event_struct(evt_struct, fast_fail_rsp, VIOSRP_MAD_FORMAT, info_timeout);
+
+	fast_fail_mad = &evt_struct->iu.mad.fast_fail;
+	memset(fast_fail_mad, 0, sizeof(*fast_fail_mad));
+	fast_fail_mad->common.type = cpu_to_be32(VIOSRP_ENABLE_FAST_FAIL);
+	fast_fail_mad->common.length = cpu_to_be16(sizeof(*fast_fail_mad));
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, info_timeout * 2);
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+	return rc;
+}
+
+/**
+ * adapter_info_rsp: - Handle response to MAD adapter info request
+ * @evt_struct:	srp_event_struct with the response
+ *
+ * Used as a "done" callback by when sending adapter_info. Gets called
+ * by ibmvscsi_handle_crq()
+*/
+static void adapter_info_rsp(struct srp_event_struct *evt_struct)
+{
+	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
+
+	if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
+		dev_err(hostdata->dev, "error %d getting adapter info\n",
+			evt_struct->xfer_iu->mad.adapter_info.common.status);
+	} else {
+		dev_info(hostdata->dev, "host srp version: %s, "
+			 "host partition %s (%d), OS %d, max io %u\n",
+			 hostdata->madapter_info.srp_version,
+			 hostdata->madapter_info.partition_name,
+			 be32_to_cpu(hostdata->madapter_info.partition_number),
+			 be32_to_cpu(hostdata->madapter_info.os_type),
+			 be32_to_cpu(hostdata->madapter_info.port_max_txu[0]));
+		
+		if (hostdata->madapter_info.port_max_txu[0]) 
+			hostdata->host->max_sectors = 
+				be32_to_cpu(hostdata->madapter_info.port_max_txu[0]) >> 9;
+		
+		if (be32_to_cpu(hostdata->madapter_info.os_type) == SRP_MAD_OS_AIX &&
+		    strcmp(hostdata->madapter_info.srp_version, "1.6a") <= 0) {
+			dev_err(hostdata->dev, "host (Ver. %s) doesn't support large transfers\n",
+				hostdata->madapter_info.srp_version);
+			dev_err(hostdata->dev, "limiting scatterlists to %d\n",
+				MAX_INDIRECT_BUFS);
+			hostdata->host->sg_tablesize = MAX_INDIRECT_BUFS;
+		}
+
+		if (be32_to_cpu(hostdata->madapter_info.os_type) == SRP_MAD_OS_AIX) {
+			enable_fast_fail(hostdata);
+			return;
+		}
+	}
+
+	send_srp_login(hostdata);
+}
+
+/**
+ * send_mad_adapter_info: - Sends the mad adapter info request
+ *      and stores the result so it can be retrieved with
+ *      sysfs.  We COULD consider causing a failure if the
+ *      returned SRP version doesn't match ours.
+ * @hostdata:	ibmvscsi_host_data of host
+ * 
+ * Returns zero if successful.
+*/
+static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata)
+{
+	struct viosrp_adapter_info *req;
+	struct srp_event_struct *evt_struct;
+	unsigned long flags;
+
+	evt_struct = get_event_struct(&hostdata->pool);
+	BUG_ON(!evt_struct);
+
+	init_event_struct(evt_struct,
+			  adapter_info_rsp,
+			  VIOSRP_MAD_FORMAT,
+			  info_timeout);
+	
+	req = &evt_struct->iu.mad.adapter_info;
+	memset(req, 0x00, sizeof(*req));
+	
+	req->common.type = cpu_to_be32(VIOSRP_ADAPTER_INFO_TYPE);
+	req->common.length = cpu_to_be16(sizeof(hostdata->madapter_info));
+	req->buffer = cpu_to_be64(hostdata->adapter_info_addr);
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	if (ibmvscsi_send_srp_event(evt_struct, hostdata, info_timeout * 2))
+		dev_err(hostdata->dev, "couldn't send ADAPTER_INFO_REQ!\n");
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+};
+
+/**
+ * init_adapter: Start virtual adapter initialization sequence
+ *
+ */
+static void init_adapter(struct ibmvscsi_host_data *hostdata)
+{
+	send_mad_adapter_info(hostdata);
+}
+
+/**
+ * sync_completion: Signal that a synchronous command has completed
+ * Note that after returning from this call, the evt_struct is freed.
+ * the caller waiting on this completion shouldn't touch the evt_struct
+ * again.
+ */
+static void sync_completion(struct srp_event_struct *evt_struct)
+{
+	/* copy the response back */
+	if (evt_struct->sync_srp)
+		*evt_struct->sync_srp = *evt_struct->xfer_iu;
+	
+	complete(&evt_struct->comp);
+}
+
+/**
+ * ibmvscsi_abort: Abort a command...from scsi host template
+ * send this over to the server and wait synchronously for the response
+ */
+static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd)
+{
+	struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
+	struct srp_tsk_mgmt *tsk_mgmt;
+	struct srp_event_struct *evt;
+	struct srp_event_struct *tmp_evt, *found_evt;
+	union viosrp_iu srp_rsp;
+	int rsp_rc;
+	unsigned long flags;
+	u16 lun = lun_from_dev(cmd->device);
+	unsigned long wait_switch = 0;
+
+	/* First, find this command in our sent list so we can figure
+	 * out the correct tag
+	 */
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	wait_switch = jiffies + (init_timeout * HZ);
+	do {
+		found_evt = NULL;
+		list_for_each_entry(tmp_evt, &hostdata->sent, list) {
+			if (tmp_evt->cmnd == cmd) {
+				found_evt = tmp_evt;
+				break;
+			}
+		}
+
+		if (!found_evt) {
+			spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+			return SUCCESS;
+		}
+
+		evt = get_event_struct(&hostdata->pool);
+		if (evt == NULL) {
+			spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+			sdev_printk(KERN_ERR, cmd->device,
+				"failed to allocate abort event\n");
+			return FAILED;
+		}
+	
+		init_event_struct(evt,
+				  sync_completion,
+				  VIOSRP_SRP_FORMAT,
+				  abort_timeout);
+
+		tsk_mgmt = &evt->iu.srp.tsk_mgmt;
+	
+		/* Set up an abort SRP command */
+		memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
+		tsk_mgmt->opcode = SRP_TSK_MGMT;
+		int_to_scsilun(lun, &tsk_mgmt->lun);
+		tsk_mgmt->tsk_mgmt_func = SRP_TSK_ABORT_TASK;
+		tsk_mgmt->task_tag = (u64) found_evt;
+
+		evt->sync_srp = &srp_rsp;
+
+		init_completion(&evt->comp);
+		rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, abort_timeout * 2);
+
+		if (rsp_rc != SCSI_MLQUEUE_HOST_BUSY)
+			break;
+
+		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+		msleep(10);
+		spin_lock_irqsave(hostdata->host->host_lock, flags);
+	} while (time_before(jiffies, wait_switch));
+
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+
+	if (rsp_rc != 0) {
+		sdev_printk(KERN_ERR, cmd->device,
+			    "failed to send abort() event. rc=%d\n", rsp_rc);
+		return FAILED;
+	}
+
+	sdev_printk(KERN_INFO, cmd->device,
+                    "aborting command. lun 0x%llx, tag 0x%llx\n",
+		    (((u64) lun) << 48), (u64) found_evt);
+
+	wait_for_completion(&evt->comp);
+
+	/* make sure we got a good response */
+	if (unlikely(srp_rsp.srp.rsp.opcode != SRP_RSP)) {
+		if (printk_ratelimit())
+			sdev_printk(KERN_WARNING, cmd->device, "abort bad SRP RSP type %d\n",
+				    srp_rsp.srp.rsp.opcode);
+		return FAILED;
+	}
+
+	if (srp_rsp.srp.rsp.flags & SRP_RSP_FLAG_RSPVALID)
+		rsp_rc = *((int *)srp_rsp.srp.rsp.data);
+	else
+		rsp_rc = srp_rsp.srp.rsp.status;
+
+	if (rsp_rc) {
+		if (printk_ratelimit())
+			sdev_printk(KERN_WARNING, cmd->device,
+				    "abort code %d for task tag 0x%llx\n",
+				    rsp_rc, tsk_mgmt->task_tag);
+		return FAILED;
+	}
+
+	/* Because we dropped the spinlock above, it's possible
+	 * The event is no longer in our list.  Make sure it didn't
+	 * complete while we were aborting
+	 */
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	found_evt = NULL;
+	list_for_each_entry(tmp_evt, &hostdata->sent, list) {
+		if (tmp_evt->cmnd == cmd) {
+			found_evt = tmp_evt;
+			break;
+		}
+	}
+
+	if (found_evt == NULL) {
+		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+		sdev_printk(KERN_INFO, cmd->device, "aborted task tag 0x%llx completed\n",
+			    tsk_mgmt->task_tag);
+		return SUCCESS;
+	}
+
+	sdev_printk(KERN_INFO, cmd->device, "successfully aborted task tag 0x%llx\n",
+		    tsk_mgmt->task_tag);
+
+	cmd->result = (DID_ABORT << 16);
+	list_del(&found_evt->list);
+	unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt,
+		       found_evt->hostdata->dev);
+	free_event_struct(&found_evt->hostdata->pool, found_evt);
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+	atomic_inc(&hostdata->request_limit);
+	return SUCCESS;
+}
+
+/**
+ * ibmvscsi_eh_device_reset_handler: Reset a single LUN...from scsi host 
+ * template send this over to the server and wait synchronously for the 
+ * response
+ */
+static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd)
+{
+	struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
+	struct srp_tsk_mgmt *tsk_mgmt;
+	struct srp_event_struct *evt;
+	struct srp_event_struct *tmp_evt, *pos;
+	union viosrp_iu srp_rsp;
+	int rsp_rc;
+	unsigned long flags;
+	u16 lun = lun_from_dev(cmd->device);
+	unsigned long wait_switch = 0;
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	wait_switch = jiffies + (init_timeout * HZ);
+	do {
+		evt = get_event_struct(&hostdata->pool);
+		if (evt == NULL) {
+			spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+			sdev_printk(KERN_ERR, cmd->device,
+				"failed to allocate reset event\n");
+			return FAILED;
+		}
+	
+		init_event_struct(evt,
+				  sync_completion,
+				  VIOSRP_SRP_FORMAT,
+				  reset_timeout);
+
+		tsk_mgmt = &evt->iu.srp.tsk_mgmt;
+
+		/* Set up a lun reset SRP command */
+		memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
+		tsk_mgmt->opcode = SRP_TSK_MGMT;
+		int_to_scsilun(lun, &tsk_mgmt->lun);
+		tsk_mgmt->tsk_mgmt_func = SRP_TSK_LUN_RESET;
+
+		evt->sync_srp = &srp_rsp;
+
+		init_completion(&evt->comp);
+		rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, reset_timeout * 2);
+
+		if (rsp_rc != SCSI_MLQUEUE_HOST_BUSY)
+			break;
+
+		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+		msleep(10);
+		spin_lock_irqsave(hostdata->host->host_lock, flags);
+	} while (time_before(jiffies, wait_switch));
+
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+
+	if (rsp_rc != 0) {
+		sdev_printk(KERN_ERR, cmd->device,
+			    "failed to send reset event. rc=%d\n", rsp_rc);
+		return FAILED;
+	}
+
+	sdev_printk(KERN_INFO, cmd->device, "resetting device. lun 0x%llx\n",
+		    (((u64) lun) << 48));
+
+	wait_for_completion(&evt->comp);
+
+	/* make sure we got a good response */
+	if (unlikely(srp_rsp.srp.rsp.opcode != SRP_RSP)) {
+		if (printk_ratelimit())
+			sdev_printk(KERN_WARNING, cmd->device, "reset bad SRP RSP type %d\n",
+				    srp_rsp.srp.rsp.opcode);
+		return FAILED;
+	}
+
+	if (srp_rsp.srp.rsp.flags & SRP_RSP_FLAG_RSPVALID)
+		rsp_rc = *((int *)srp_rsp.srp.rsp.data);
+	else
+		rsp_rc = srp_rsp.srp.rsp.status;
+
+	if (rsp_rc) {
+		if (printk_ratelimit())
+			sdev_printk(KERN_WARNING, cmd->device,
+				    "reset code %d for task tag 0x%llx\n",
+				    rsp_rc, tsk_mgmt->task_tag);
+		return FAILED;
+	}
+
+	/* We need to find all commands for this LUN that have not yet been
+	 * responded to, and fail them with DID_RESET
+	 */
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
+		if ((tmp_evt->cmnd) && (tmp_evt->cmnd->device == cmd->device)) {
+			if (tmp_evt->cmnd)
+				tmp_evt->cmnd->result = (DID_RESET << 16);
+			list_del(&tmp_evt->list);
+			unmap_cmd_data(&tmp_evt->iu.srp.cmd, tmp_evt,
+				       tmp_evt->hostdata->dev);
+			free_event_struct(&tmp_evt->hostdata->pool,
+						   tmp_evt);
+			atomic_inc(&hostdata->request_limit);
+			if (tmp_evt->cmnd_done)
+				tmp_evt->cmnd_done(tmp_evt->cmnd);
+			else if (tmp_evt->done)
+				tmp_evt->done(tmp_evt);
+		}
+	}
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+	return SUCCESS;
+}
+
+/**
+ * ibmvscsi_eh_host_reset_handler - Reset the connection to the server
+ * @cmd:	struct scsi_cmnd having problems
+*/
+static int ibmvscsi_eh_host_reset_handler(struct scsi_cmnd *cmd)
+{
+	unsigned long wait_switch = 0;
+	struct ibmvscsi_host_data *hostdata = shost_priv(cmd->device->host);
+
+	dev_err(hostdata->dev, "Resetting connection due to error recovery\n");
+
+	ibmvscsi_reset_host(hostdata);
+
+	for (wait_switch = jiffies + (init_timeout * HZ);
+	     time_before(jiffies, wait_switch) &&
+		     atomic_read(&hostdata->request_limit) < 2;) {
+
+		msleep(10);
+	}
+
+	if (atomic_read(&hostdata->request_limit) <= 0)
+		return FAILED;
+
+	return SUCCESS;
+}
+
+/**
+ * ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
+ * @crq:	Command/Response queue
+ * @hostdata:	ibmvscsi_host_data of host
+ *
+*/
+static void ibmvscsi_handle_crq(struct viosrp_crq *crq,
+				struct ibmvscsi_host_data *hostdata)
+{
+	long rc;
+	unsigned long flags;
+	/* The hypervisor copies our tag value here so no byteswapping */
+	struct srp_event_struct *evt_struct =
+			(__force struct srp_event_struct *)crq->IU_data_ptr;
+	switch (crq->valid) {
+	case VIOSRP_CRQ_INIT_RSP:		/* initialization */
+		switch (crq->format) {
+		case VIOSRP_CRQ_INIT:	/* Initialization message */
+			dev_info(hostdata->dev, "partner initialized\n");
+			/* Send back a response */
+			rc = ibmvscsi_send_crq(hostdata, 0xC002000000000000LL, 0);
+			if (rc == 0) {
+				/* Now login */
+				init_adapter(hostdata);
+			} else {
+				dev_err(hostdata->dev, "Unable to send init rsp. rc=%ld\n", rc);
+			}
+
+			break;
+		case VIOSRP_CRQ_INIT_COMPLETE:	/* Initialization response */
+			dev_info(hostdata->dev, "partner initialization complete\n");
+
+			/* Now login */
+			init_adapter(hostdata);
+			break;
+		default:
+			dev_err(hostdata->dev, "unknown crq message type: %d\n", crq->format);
+		}
+		return;
+	case VIOSRP_CRQ_XPORT_EVENT:	/* Hypervisor telling us the connection is closed */
+		scsi_block_requests(hostdata->host);
+		ibmvscsi_set_request_limit(hostdata, 0);
+		if (crq->format == 0x06) {
+			/* We need to re-setup the interpartition connection */
+			dev_info(hostdata->dev, "Re-enabling adapter!\n");
+			hostdata->client_migrated = 1;
+			hostdata->action = IBMVSCSI_HOST_ACTION_REENABLE;
+			purge_requests(hostdata, DID_REQUEUE);
+			wake_up(&hostdata->work_wait_q);
+		} else {
+			dev_err(hostdata->dev, "Virtual adapter failed rc %d!\n",
+				crq->format);
+			ibmvscsi_reset_host(hostdata);
+		}
+		return;
+	case VIOSRP_CRQ_CMD_RSP:		/* real payload */
+		break;
+	default:
+		dev_err(hostdata->dev, "got an invalid message type 0x%02x\n",
+			crq->valid);
+		return;
+	}
+
+	/* The only kind of payload CRQs we should get are responses to
+	 * things we send. Make sure this response is to something we
+	 * actually sent
+	 */
+	if (!valid_event_struct(&hostdata->pool, evt_struct)) {
+		dev_err(hostdata->dev, "returned correlation_token 0x%p is invalid!\n",
+		       evt_struct);
+		return;
+	}
+
+	if (atomic_read(&evt_struct->free)) {
+		dev_err(hostdata->dev, "received duplicate correlation_token 0x%p!\n",
+			evt_struct);
+		return;
+	}
+
+	if (crq->format == VIOSRP_SRP_FORMAT)
+		atomic_add(be32_to_cpu(evt_struct->xfer_iu->srp.rsp.req_lim_delta),
+			   &hostdata->request_limit);
+
+	del_timer(&evt_struct->timer);
+
+	if ((crq->status != VIOSRP_OK && crq->status != VIOSRP_OK2) && evt_struct->cmnd)
+		evt_struct->cmnd->result = DID_ERROR << 16;
+	if (evt_struct->done)
+		evt_struct->done(evt_struct);
+	else
+		dev_err(hostdata->dev, "returned done() is NULL; not running it!\n");
+
+	/*
+	 * Lock the host_lock before messing with these structures, since we
+	 * are running in a task context
+	 */
+	spin_lock_irqsave(evt_struct->hostdata->host->host_lock, flags);
+	list_del(&evt_struct->list);
+	free_event_struct(&evt_struct->hostdata->pool, evt_struct);
+	spin_unlock_irqrestore(evt_struct->hostdata->host->host_lock, flags);
+}
+
+/**
+ * ibmvscsi_slave_configure: Set the "allow_restart" flag for each disk.
+ * @sdev:	struct scsi_device device to configure
+ *
+ * Enable allow_restart for a device if it is a disk.  Adjust the
+ * queue_depth here also as is required by the documentation for
+ * struct scsi_host_template.
+ */
+static int ibmvscsi_slave_configure(struct scsi_device *sdev)
+{
+	struct Scsi_Host *shost = sdev->host;
+	unsigned long lock_flags = 0;
+
+	spin_lock_irqsave(shost->host_lock, lock_flags);
+	if (sdev->type == TYPE_DISK) {
+		sdev->allow_restart = 1;
+		blk_queue_rq_timeout(sdev->request_queue, 120 * HZ);
+	}
+	spin_unlock_irqrestore(shost->host_lock, lock_flags);
+	return 0;
+}
+
+/**
+ * ibmvscsi_change_queue_depth - Change the device's queue depth
+ * @sdev:	scsi device struct
+ * @qdepth:	depth to set
+ * @reason:	calling context
+ *
+ * Return value:
+ * 	actual depth set
+ **/
+static int ibmvscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
+{
+	if (qdepth > IBMVSCSI_MAX_CMDS_PER_LUN)
+		qdepth = IBMVSCSI_MAX_CMDS_PER_LUN;
+	return scsi_change_queue_depth(sdev, qdepth);
+}
+
+/* ------------------------------------------------------------
+ * sysfs attributes
+ */
+static ssize_t show_host_vhost_loc(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
+	int len;
+
+	len = snprintf(buf, sizeof(hostdata->caps.loc), "%s\n",
+		       hostdata->caps.loc);
+	return len;
+}
+
+static struct device_attribute ibmvscsi_host_vhost_loc = {
+	.attr = {
+		 .name = "vhost_loc",
+		 .mode = S_IRUGO,
+		 },
+	.show = show_host_vhost_loc,
+};
+
+static ssize_t show_host_vhost_name(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
+	int len;
+
+	len = snprintf(buf, sizeof(hostdata->caps.name), "%s\n",
+		       hostdata->caps.name);
+	return len;
+}
+
+static struct device_attribute ibmvscsi_host_vhost_name = {
+	.attr = {
+		 .name = "vhost_name",
+		 .mode = S_IRUGO,
+		 },
+	.show = show_host_vhost_name,
+};
+
+static ssize_t show_host_srp_version(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "%s\n",
+		       hostdata->madapter_info.srp_version);
+	return len;
+}
+
+static struct device_attribute ibmvscsi_host_srp_version = {
+	.attr = {
+		 .name = "srp_version",
+		 .mode = S_IRUGO,
+		 },
+	.show = show_host_srp_version,
+};
+
+static ssize_t show_host_partition_name(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "%s\n",
+		       hostdata->madapter_info.partition_name);
+	return len;
+}
+
+static struct device_attribute ibmvscsi_host_partition_name = {
+	.attr = {
+		 .name = "partition_name",
+		 .mode = S_IRUGO,
+		 },
+	.show = show_host_partition_name,
+};
+
+static ssize_t show_host_partition_number(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "%d\n",
+		       be32_to_cpu(hostdata->madapter_info.partition_number));
+	return len;
+}
+
+static struct device_attribute ibmvscsi_host_partition_number = {
+	.attr = {
+		 .name = "partition_number",
+		 .mode = S_IRUGO,
+		 },
+	.show = show_host_partition_number,
+};
+
+static ssize_t show_host_mad_version(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "%d\n",
+		       be32_to_cpu(hostdata->madapter_info.mad_version));
+	return len;
+}
+
+static struct device_attribute ibmvscsi_host_mad_version = {
+	.attr = {
+		 .name = "mad_version",
+		 .mode = S_IRUGO,
+		 },
+	.show = show_host_mad_version,
+};
+
+static ssize_t show_host_os_type(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "%d\n",
+		       be32_to_cpu(hostdata->madapter_info.os_type));
+	return len;
+}
+
+static struct device_attribute ibmvscsi_host_os_type = {
+	.attr = {
+		 .name = "os_type",
+		 .mode = S_IRUGO,
+		 },
+	.show = show_host_os_type,
+};
+
+static ssize_t show_host_config(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	return 0;
+}
+
+static struct device_attribute ibmvscsi_host_config = {
+	.attr = {
+		.name = "config",
+		.mode = S_IRUGO,
+		},
+	.show = show_host_config,
+};
+
+static int ibmvscsi_host_reset(struct Scsi_Host *shost, int reset_type)
+{
+	struct ibmvscsi_host_data *hostdata = shost_priv(shost);
+
+	dev_info(hostdata->dev, "Initiating adapter reset!\n");
+	ibmvscsi_reset_host(hostdata);
+
+	return 0;
+}
+
+static struct device_attribute *ibmvscsi_attrs[] = {
+	&ibmvscsi_host_vhost_loc,
+	&ibmvscsi_host_vhost_name,
+	&ibmvscsi_host_srp_version,
+	&ibmvscsi_host_partition_name,
+	&ibmvscsi_host_partition_number,
+	&ibmvscsi_host_mad_version,
+	&ibmvscsi_host_os_type,
+	&ibmvscsi_host_config,
+	NULL
+};
+
+/* ------------------------------------------------------------
+ * SCSI driver registration
+ */
+static struct scsi_host_template driver_template = {
+	.module = THIS_MODULE,
+	.name = "IBM POWER Virtual SCSI Adapter " IBMVSCSI_VERSION,
+	.proc_name = "ibmvscsi",
+	.queuecommand = ibmvscsi_queuecommand,
+	.eh_timed_out = srp_timed_out,
+	.eh_abort_handler = ibmvscsi_eh_abort_handler,
+	.eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
+	.eh_host_reset_handler = ibmvscsi_eh_host_reset_handler,
+	.slave_configure = ibmvscsi_slave_configure,
+	.change_queue_depth = ibmvscsi_change_queue_depth,
+	.host_reset = ibmvscsi_host_reset,
+	.cmd_per_lun = IBMVSCSI_CMDS_PER_LUN_DEFAULT,
+	.can_queue = IBMVSCSI_MAX_REQUESTS_DEFAULT,
+	.this_id = -1,
+	.sg_tablesize = SG_ALL,
+	.shost_attrs = ibmvscsi_attrs,
+};
+
+/**
+ * ibmvscsi_get_desired_dma - Calculate IO memory desired by the driver
+ *
+ * @vdev: struct vio_dev for the device whose desired IO mem is to be returned
+ *
+ * Return value:
+ *	Number of bytes of IO data the driver will need to perform well.
+ */
+static unsigned long ibmvscsi_get_desired_dma(struct vio_dev *vdev)
+{
+	/* iu_storage data allocated in initialize_event_pool */
+	unsigned long desired_io = max_events * sizeof(union viosrp_iu);
+
+	/* add io space for sg data */
+	desired_io += (IBMVSCSI_MAX_SECTORS_DEFAULT * 512 *
+	                     IBMVSCSI_CMDS_PER_LUN_DEFAULT);
+
+	return desired_io;
+}
+
+static void ibmvscsi_do_work(struct ibmvscsi_host_data *hostdata)
+{
+	unsigned long flags;
+	int rc;
+	char *action = "reset";
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	switch (hostdata->action) {
+	case IBMVSCSI_HOST_ACTION_UNBLOCK:
+		rc = 0;
+		break;
+	case IBMVSCSI_HOST_ACTION_RESET:
+		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+		rc = ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
+		spin_lock_irqsave(hostdata->host->host_lock, flags);
+		if (!rc)
+			rc = ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0);
+		vio_enable_interrupts(to_vio_dev(hostdata->dev));
+		break;
+	case IBMVSCSI_HOST_ACTION_REENABLE:
+		action = "enable";
+		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+		rc = ibmvscsi_reenable_crq_queue(&hostdata->queue, hostdata);
+		spin_lock_irqsave(hostdata->host->host_lock, flags);
+		if (!rc)
+			rc = ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0);
+		break;
+	case IBMVSCSI_HOST_ACTION_NONE:
+	default:
+		spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+		return;
+	}
+
+	hostdata->action = IBMVSCSI_HOST_ACTION_NONE;
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+
+	if (rc) {
+		ibmvscsi_set_request_limit(hostdata, -1);
+		dev_err(hostdata->dev, "error after %s\n", action);
+	}
+
+	scsi_unblock_requests(hostdata->host);
+}
+
+static int __ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata)
+{
+	if (kthread_should_stop())
+		return 1;
+	switch (hostdata->action) {
+	case IBMVSCSI_HOST_ACTION_NONE:
+		return 0;
+	case IBMVSCSI_HOST_ACTION_RESET:
+	case IBMVSCSI_HOST_ACTION_REENABLE:
+	case IBMVSCSI_HOST_ACTION_UNBLOCK:
+	default:
+		break;
+	}
+
+	return 1;
+}
+
+static int ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata)
+{
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	rc = __ibmvscsi_work_to_do(hostdata);
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+
+	return rc;
+}
+
+static int ibmvscsi_work(void *data)
+{
+	struct ibmvscsi_host_data *hostdata = data;
+	int rc;
+
+	set_user_nice(current, MIN_NICE);
+
+	while (1) {
+		rc = wait_event_interruptible(hostdata->work_wait_q,
+					      ibmvscsi_work_to_do(hostdata));
+
+		BUG_ON(rc);
+
+		if (kthread_should_stop())
+			break;
+
+		ibmvscsi_do_work(hostdata);
+	}
+
+	return 0;
+}
+
+/**
+ * Called by bus code for each adapter
+ */
+static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
+{
+	struct ibmvscsi_host_data *hostdata;
+	struct Scsi_Host *host;
+	struct device *dev = &vdev->dev;
+	struct srp_rport_identifiers ids;
+	struct srp_rport *rport;
+	unsigned long wait_switch = 0;
+	int rc;
+
+	dev_set_drvdata(&vdev->dev, NULL);
+
+	host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
+	if (!host) {
+		dev_err(&vdev->dev, "couldn't allocate host data\n");
+		goto scsi_host_alloc_failed;
+	}
+
+	host->transportt = ibmvscsi_transport_template;
+	hostdata = shost_priv(host);
+	memset(hostdata, 0x00, sizeof(*hostdata));
+	INIT_LIST_HEAD(&hostdata->sent);
+	init_waitqueue_head(&hostdata->work_wait_q);
+	hostdata->host = host;
+	hostdata->dev = dev;
+	ibmvscsi_set_request_limit(hostdata, -1);
+	hostdata->host->max_sectors = IBMVSCSI_MAX_SECTORS_DEFAULT;
+
+	if (map_persist_bufs(hostdata)) {
+		dev_err(&vdev->dev, "couldn't map persistent buffers\n");
+		goto persist_bufs_failed;
+	}
+
+	hostdata->work_thread = kthread_run(ibmvscsi_work, hostdata, "%s_%d",
+					    "ibmvscsi", host->host_no);
+
+	if (IS_ERR(hostdata->work_thread)) {
+		dev_err(&vdev->dev, "couldn't initialize kthread. rc=%ld\n",
+			PTR_ERR(hostdata->work_thread));
+		goto init_crq_failed;
+	}
+
+	rc = ibmvscsi_init_crq_queue(&hostdata->queue, hostdata, max_events);
+	if (rc != 0 && rc != H_RESOURCE) {
+		dev_err(&vdev->dev, "couldn't initialize crq. rc=%d\n", rc);
+		goto kill_kthread;
+	}
+	if (initialize_event_pool(&hostdata->pool, max_events, hostdata) != 0) {
+		dev_err(&vdev->dev, "couldn't initialize event pool\n");
+		goto init_pool_failed;
+	}
+
+	host->max_lun = IBMVSCSI_MAX_LUN;
+	host->max_id = max_id;
+	host->max_channel = max_channel;
+	host->max_cmd_len = 16;
+
+	dev_info(dev,
+		 "Maximum ID: %d Maximum LUN: %llu Maximum Channel: %d\n",
+		 host->max_id, host->max_lun, host->max_channel);
+
+	if (scsi_add_host(hostdata->host, hostdata->dev))
+		goto add_host_failed;
+
+	/* we don't have a proper target_port_id so let's use the fake one */
+	memcpy(ids.port_id, hostdata->madapter_info.partition_name,
+	       sizeof(ids.port_id));
+	ids.roles = SRP_RPORT_ROLE_TARGET;
+	rport = srp_rport_add(host, &ids);
+	if (IS_ERR(rport))
+		goto add_srp_port_failed;
+
+	/* Try to send an initialization message.  Note that this is allowed
+	 * to fail if the other end is not acive.  In that case we don't
+	 * want to scan
+	 */
+	if (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0) == 0
+	    || rc == H_RESOURCE) {
+		/*
+		 * Wait around max init_timeout secs for the adapter to finish
+		 * initializing. When we are done initializing, we will have a
+		 * valid request_limit.  We don't want Linux scanning before
+		 * we are ready.
+		 */
+		for (wait_switch = jiffies + (init_timeout * HZ);
+		     time_before(jiffies, wait_switch) &&
+		     atomic_read(&hostdata->request_limit) < 2;) {
+
+			msleep(10);
+		}
+
+		/* if we now have a valid request_limit, initiate a scan */
+		if (atomic_read(&hostdata->request_limit) > 0)
+			scsi_scan_host(host);
+	}
+
+	dev_set_drvdata(&vdev->dev, hostdata);
+	spin_lock(&ibmvscsi_driver_lock);
+	list_add_tail(&hostdata->host_list, &ibmvscsi_head);
+	spin_unlock(&ibmvscsi_driver_lock);
+	return 0;
+
+      add_srp_port_failed:
+	scsi_remove_host(hostdata->host);
+      add_host_failed:
+	release_event_pool(&hostdata->pool, hostdata);
+      init_pool_failed:
+	ibmvscsi_release_crq_queue(&hostdata->queue, hostdata, max_events);
+      kill_kthread:
+      kthread_stop(hostdata->work_thread);
+      init_crq_failed:
+	unmap_persist_bufs(hostdata);
+      persist_bufs_failed:
+	scsi_host_put(host);
+      scsi_host_alloc_failed:
+	return -1;
+}
+
+static int ibmvscsi_remove(struct vio_dev *vdev)
+{
+	struct ibmvscsi_host_data *hostdata = dev_get_drvdata(&vdev->dev);
+
+	srp_remove_host(hostdata->host);
+	scsi_remove_host(hostdata->host);
+
+	purge_requests(hostdata, DID_ERROR);
+	release_event_pool(&hostdata->pool, hostdata);
+
+	ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
+					max_events);
+
+	kthread_stop(hostdata->work_thread);
+	unmap_persist_bufs(hostdata);
+
+	spin_lock(&ibmvscsi_driver_lock);
+	list_del(&hostdata->host_list);
+	spin_unlock(&ibmvscsi_driver_lock);
+
+	scsi_host_put(hostdata->host);
+
+	return 0;
+}
+
+/**
+ * ibmvscsi_resume: Resume from suspend
+ * @dev:	device struct
+ *
+ * We may have lost an interrupt across suspend/resume, so kick the
+ * interrupt handler
+ */
+static int ibmvscsi_resume(struct device *dev)
+{
+	struct ibmvscsi_host_data *hostdata = dev_get_drvdata(dev);
+	vio_disable_interrupts(to_vio_dev(hostdata->dev));
+	tasklet_schedule(&hostdata->srp_task);
+
+	return 0;
+}
+
+/**
+ * ibmvscsi_device_table: Used by vio.c to match devices in the device tree we 
+ * support.
+ */
+static const struct vio_device_id ibmvscsi_device_table[] = {
+	{"vscsi", "IBM,v-scsi"},
+	{ "", "" }
+};
+MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
+
+static const struct dev_pm_ops ibmvscsi_pm_ops = {
+	.resume = ibmvscsi_resume
+};
+
+static struct vio_driver ibmvscsi_driver = {
+	.id_table = ibmvscsi_device_table,
+	.probe = ibmvscsi_probe,
+	.remove = ibmvscsi_remove,
+	.get_desired_dma = ibmvscsi_get_desired_dma,
+	.name = "ibmvscsi",
+	.pm = &ibmvscsi_pm_ops,
+};
+
+static struct srp_function_template ibmvscsi_transport_functions = {
+};
+
+static int __init ibmvscsi_module_init(void)
+{
+	int ret;
+
+	/* Ensure we have two requests to do error recovery */
+	driver_template.can_queue = max_requests;
+	max_events = max_requests + 2;
+
+	if (!firmware_has_feature(FW_FEATURE_VIO))
+		return -ENODEV;
+
+	ibmvscsi_transport_template =
+		srp_attach_transport(&ibmvscsi_transport_functions);
+	if (!ibmvscsi_transport_template)
+		return -ENOMEM;
+
+	ret = vio_register_driver(&ibmvscsi_driver);
+	if (ret)
+		srp_release_transport(ibmvscsi_transport_template);
+	return ret;
+}
+
+static void __exit ibmvscsi_module_exit(void)
+{
+	vio_unregister_driver(&ibmvscsi_driver);
+	srp_release_transport(ibmvscsi_transport_template);
+}
+
+module_init(ibmvscsi_module_init);
+module_exit(ibmvscsi_module_exit);