Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1473 insertions, 0 deletions

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
new file mode 100644
index 000000000000..e89f76e5dd53
--- /dev/null
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -0,0 +1,1473 @@
+/* ------------------------------------------------------------
+ * 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)
+ *
+ * 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
+ *
+ * ------------------------------------------------------------
+ * 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-robbin 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.
+ *
+ * Note that some of the underlying infrastructure is different between
+ * machines conforming to the "RS/6000 Platform Architecture" (RPA) and
+ * the older iSeries hypervisor models.  To support both, some low level
+ * routines have been broken out into rpa_vscsi.c and iseries_vscsi.c.
+ * The Makefile should pick one, not two, not zero, of these.
+ *
+ * TODO: This is currently pretty tied to the IBM i/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 <asm/vio.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.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 = 5;
+static int max_requests = 50;
+
+#define IBMVSCSI_VERSION "1.5.5"
+
+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");
+module_param_named(max_channel, max_channel, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(max_channel, "Largest channel value");
+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 | S_IWUSR);
+MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter");
+
+/* ------------------------------------------------------------
+ * 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 = kmalloc(pool->size * sizeof(*pool->events), GFP_KERNEL);
+	if (!pool->events)
+		return -ENOMEM;
+	memset(pool->events, 0x00, pool->size * sizeof(*pool->events));
+
+	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 = 0x80;
+		evt->crq.IU_length = sizeof(*evt->xfer_iu);
+		evt->crq.IU_data_ptr = pool->iu_token + 
+			sizeof(*evt->xfer_iu) * i;
+		evt->xfer_iu = pool->iu_storage + i;
+		evt->hostdata = hostdata;
+	}
+
+	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 (in_use)
+		printk(KERN_WARNING
+		       "ibmvscsi: 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)) {
+		printk(KERN_ERR
+		       "ibmvscsi: Freeing invalid event_struct %p "
+		       "(not in pool %p)\n", evt, pool->events);
+		return;
+	}
+	if (atomic_inc_return(&evt->free) != 1) {
+		printk(KERN_ERR
+		       "ibmvscsi: 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 = 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)
+{
+	if (numbuf == 0)
+		return;
+	
+	if (numbuf == 1) {
+		if (cmd->sc_data_direction == DMA_TO_DEVICE)
+			srp_cmd->data_out_format = SRP_DIRECT_BUFFER;
+		else 
+			srp_cmd->data_in_format = SRP_DIRECT_BUFFER;
+	} else {
+		if (cmd->sc_data_direction == DMA_TO_DEVICE) {
+			srp_cmd->data_out_format = SRP_INDIRECT_BUFFER;
+			srp_cmd->data_out_count = numbuf;
+		} else {
+			srp_cmd->data_in_format = SRP_INDIRECT_BUFFER;
+			srp_cmd->data_in_count = numbuf;
+		}
+	}
+}
+
+/**
+ * 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 device *dev)
+{
+	int i;
+
+	if ((cmd->data_out_format == SRP_NO_BUFFER) &&
+	    (cmd->data_in_format == SRP_NO_BUFFER))
+		return;
+	else if ((cmd->data_out_format == SRP_DIRECT_BUFFER) ||
+		 (cmd->data_in_format == SRP_DIRECT_BUFFER)) {
+		struct memory_descriptor *data =
+			(struct memory_descriptor *)cmd->additional_data;
+		dma_unmap_single(dev, data->virtual_address, data->length,
+				 DMA_BIDIRECTIONAL);
+	} else {
+		struct indirect_descriptor *indirect =
+			(struct indirect_descriptor *)cmd->additional_data;
+		int num_mapped = indirect->head.length / 
+			sizeof(indirect->list[0]);
+		for (i = 0; i < num_mapped; ++i) {
+			struct memory_descriptor *data = &indirect->list[i];
+			dma_unmap_single(dev,
+					 data->virtual_address,
+					 data->length, DMA_BIDIRECTIONAL);
+		}
+	}
+}
+
+/**
+ * map_sg_data: - Maps dma for a scatterlist and initializes decriptor fields
+ * @cmd:	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_cmd *srp_cmd, struct device *dev)
+{
+
+	int i, sg_mapped;
+	u64 total_length = 0;
+	struct scatterlist *sg = cmd->request_buffer;
+	struct memory_descriptor *data =
+	    (struct memory_descriptor *)srp_cmd->additional_data;
+	struct indirect_descriptor *indirect =
+	    (struct indirect_descriptor *)data;
+
+	sg_mapped = dma_map_sg(dev, sg, cmd->use_sg, DMA_BIDIRECTIONAL);
+
+	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) {
+		data->virtual_address = sg_dma_address(&sg[0]);
+		data->length = sg_dma_len(&sg[0]);
+		data->memory_handle = 0;
+		return 1;
+	}
+
+	if (sg_mapped > MAX_INDIRECT_BUFS) {
+		printk(KERN_ERR
+		       "ibmvscsi: More than %d mapped sg entries, got %d\n",
+		       MAX_INDIRECT_BUFS, sg_mapped);
+		return 0;
+	}
+
+	indirect->head.virtual_address = 0;
+	indirect->head.length = sg_mapped * sizeof(indirect->list[0]);
+	indirect->head.memory_handle = 0;
+	for (i = 0; i < sg_mapped; ++i) {
+		struct memory_descriptor *descr = &indirect->list[i];
+		struct scatterlist *sg_entry = &sg[i];
+		descr->virtual_address = sg_dma_address(sg_entry);
+		descr->length = sg_dma_len(sg_entry);
+		descr->memory_handle = 0;
+		total_length += sg_dma_len(sg_entry);
+	}
+	indirect->total_length = total_length;
+
+	return 1;
+}
+
+/**
+ * map_single_data: - Maps memory and initializes memory decriptor fields
+ * @cmd:	struct scsi_cmnd with the memory to be mapped
+ * @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_single_data(struct scsi_cmnd *cmd,
+			   struct srp_cmd *srp_cmd, struct device *dev)
+{
+	struct memory_descriptor *data =
+	    (struct memory_descriptor *)srp_cmd->additional_data;
+
+	data->virtual_address =
+		dma_map_single(dev, cmd->request_buffer,
+			       cmd->request_bufflen,
+			       DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(data->virtual_address)) {
+		printk(KERN_ERR
+		       "ibmvscsi: Unable to map request_buffer for command!\n");
+		return 0;
+	}
+	data->length = cmd->request_bufflen;
+	data->memory_handle = 0;
+
+	set_srp_direction(cmd, srp_cmd, 1);
+
+	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_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:
+		printk(KERN_ERR
+		       "ibmvscsi: Can't map DMA_BIDIRECTIONAL to read/write\n");
+		return 0;
+	default:
+		printk(KERN_ERR
+		       "ibmvscsi: Unknown data direction 0x%02x; can't map!\n",
+		       cmd->sc_data_direction);
+		return 0;
+	}
+
+	if (!cmd->request_buffer)
+		return 1;
+	if (cmd->use_sg)
+		return map_sg_data(cmd, srp_cmd, dev);
+	return map_single_data(cmd, srp_cmd, dev);
+}
+
+/* ------------------------------------------------------------
+ * 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
+ *
+ * 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)
+{
+	struct scsi_cmnd *cmnd;
+	u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
+	int rc;
+
+	/* If we have exhausted our request limit, just fail this request.
+	 * 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) &&
+	    (atomic_dec_if_positive(&hostdata->request_limit) < 0)) {
+		/* See if the adapter is disabled */
+		if (atomic_read(&hostdata->request_limit) < 0)
+			goto send_error;
+	
+		printk(KERN_WARNING 
+		       "ibmvscsi: Warning, request_limit exceeded\n");
+		unmap_cmd_data(&evt_struct->iu.srp.cmd,
+			       hostdata->dev);
+		free_event_struct(&hostdata->pool, evt_struct);
+		return SCSI_MLQUEUE_HOST_BUSY;
+	}
+
+	/* Copy the IU into the transfer area */
+	*evt_struct->xfer_iu = evt_struct->iu;
+	evt_struct->xfer_iu->srp.generic.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);
+
+	if ((rc =
+	     ibmvscsi_send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {
+		list_del(&evt_struct->list);
+
+		printk(KERN_ERR "ibmvscsi: failed to send event struct rc %d\n",
+		       rc);
+		goto send_error;
+	}
+
+	return 0;
+
+ send_error:
+	unmap_cmd_data(&evt_struct->iu.srp.cmd, hostdata->dev);
+
+	if ((cmnd = evt_struct->cmnd) != NULL) {
+		cmnd->result = DID_ERROR << 16;
+		evt_struct->cmnd_done(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->type != SRP_RSP_TYPE)) {
+		if (printk_ratelimit())
+			printk(KERN_WARNING 
+			       "ibmvscsi: bad SRP RSP type %d\n",
+			       rsp->type);
+	}
+	
+	if (cmnd) {
+		cmnd->result = rsp->status;
+		if (((cmnd->result >> 1) & 0x1f) == CHECK_CONDITION)
+			memcpy(cmnd->sense_buffer,
+			       rsp->sense_and_response_data,
+			       rsp->sense_data_list_length);
+		unmap_cmd_data(&evt_struct->iu.srp.cmd, 
+			       evt_struct->hostdata->dev);
+
+		if (rsp->doover)
+			cmnd->resid = rsp->data_out_residual_count;
+		else if (rsp->diover)
+			cmnd->resid = rsp->data_in_residual_count;
+	}
+
+	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(struct scsi_cmnd *cmnd,
+				 void (*done) (struct scsi_cmnd *))
+{
+	struct srp_cmd *srp_cmd;
+	struct srp_event_struct *evt_struct;
+	struct ibmvscsi_host_data *hostdata =
+		(struct ibmvscsi_host_data *)&cmnd->device->host->hostdata;
+	u16 lun = lun_from_dev(cmnd->device);
+
+	evt_struct = get_event_struct(&hostdata->pool);
+	if (!evt_struct)
+		return SCSI_MLQUEUE_HOST_BUSY;
+
+	init_event_struct(evt_struct,
+			  handle_cmd_rsp,
+			  VIOSRP_SRP_FORMAT,
+			  cmnd->timeout);
+
+	evt_struct->cmnd = cmnd;
+	evt_struct->cmnd_done = done;
+
+	/* Set up the actual SRP IU */
+	srp_cmd = &evt_struct->iu.srp.cmd;
+	memset(srp_cmd, 0x00, sizeof(*srp_cmd));
+	srp_cmd->type = SRP_CMD_TYPE;
+	memcpy(srp_cmd->cdb, cmnd->cmnd, sizeof(cmnd->cmnd));
+	srp_cmd->lun = ((u64) lun) << 48;
+
+	if (!map_data_for_srp_cmd(cmnd, srp_cmd, hostdata->dev)) {
+		printk(KERN_ERR "ibmvscsi: couldn't convert cmd to srp_cmd\n");
+		free_event_struct(&hostdata->pool, evt_struct);
+		return SCSI_MLQUEUE_HOST_BUSY;
+	}
+
+	/* Fix up dma address of the buffer itself */
+	if ((srp_cmd->data_out_format == SRP_INDIRECT_BUFFER) ||
+	    (srp_cmd->data_in_format == SRP_INDIRECT_BUFFER)) {
+		struct indirect_descriptor *indirect =
+		    (struct indirect_descriptor *)srp_cmd->additional_data;
+		indirect->head.virtual_address = evt_struct->crq.IU_data_ptr +
+		    offsetof(struct srp_cmd, additional_data) +
+		    offsetof(struct indirect_descriptor, list);
+	}
+
+	return ibmvscsi_send_srp_event(evt_struct, hostdata);
+}
+
+/* ------------------------------------------------------------
+ * Routines for driver initialization
+ */
+/**
+ * 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;
+	dma_unmap_single(hostdata->dev,
+			 evt_struct->iu.mad.adapter_info.buffer,
+			 evt_struct->iu.mad.adapter_info.common.length,
+			 DMA_BIDIRECTIONAL);
+
+	if (evt_struct->xfer_iu->mad.adapter_info.common.status) {
+		printk("ibmvscsi: error %d getting adapter info\n",
+		       evt_struct->xfer_iu->mad.adapter_info.common.status);
+	} else {
+		printk("ibmvscsi: host srp version: %s, "
+		       "host partition %s (%d), OS %d, max io %u\n",
+		       hostdata->madapter_info.srp_version,
+		       hostdata->madapter_info.partition_name,
+		       hostdata->madapter_info.partition_number,
+		       hostdata->madapter_info.os_type,
+		       hostdata->madapter_info.port_max_txu[0]);
+		
+		if (hostdata->madapter_info.port_max_txu[0]) 
+			hostdata->host->max_sectors = 
+				hostdata->madapter_info.port_max_txu[0] >> 9;
+	}
+}
+
+/**
+ * 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;
+	
+	memset(&hostdata->madapter_info, 0x00, sizeof(hostdata->madapter_info));
+	
+	evt_struct = get_event_struct(&hostdata->pool);
+	if (!evt_struct) {
+		printk(KERN_ERR "ibmvscsi: couldn't allocate an event "
+		       "for ADAPTER_INFO_REQ!\n");
+		return;
+	}
+
+	init_event_struct(evt_struct,
+			  adapter_info_rsp,
+			  VIOSRP_MAD_FORMAT,
+			  init_timeout * HZ);
+	
+	req = &evt_struct->iu.mad.adapter_info;
+	memset(req, 0x00, sizeof(*req));
+	
+	req->common.type = VIOSRP_ADAPTER_INFO_TYPE;
+	req->common.length = sizeof(hostdata->madapter_info);
+	req->buffer = dma_map_single(hostdata->dev,
+				     &hostdata->madapter_info,
+				     sizeof(hostdata->madapter_info),
+				     DMA_BIDIRECTIONAL);
+
+	if (dma_mapping_error(req->buffer)) {
+		printk(KERN_ERR
+		       "ibmvscsi: Unable to map request_buffer "
+		       "for adapter_info!\n");
+		free_event_struct(&hostdata->pool, evt_struct);
+		return;
+	}
+	
+	if (ibmvscsi_send_srp_event(evt_struct, hostdata))
+		printk(KERN_ERR "ibmvscsi: couldn't send ADAPTER_INFO_REQ!\n");
+};
+
+/**
+ * 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.generic.type) {
+	case SRP_LOGIN_RSP_TYPE:	/* it worked! */
+		break;
+	case SRP_LOGIN_REJ_TYPE:	/* refused! */
+		printk(KERN_INFO "ibmvscsi: SRP_LOGIN_REQ rejected\n");
+		/* Login failed.  */
+		atomic_set(&hostdata->request_limit, -1);
+		return;
+	default:
+		printk(KERN_ERR
+		       "ibmvscsi: Invalid login response typecode 0x%02x!\n",
+		       evt_struct->xfer_iu->srp.generic.type);
+		/* Login failed.  */
+		atomic_set(&hostdata->request_limit, -1);
+		return;
+	}
+
+	printk(KERN_INFO "ibmvscsi: SRP_LOGIN succeeded\n");
+
+	if (evt_struct->xfer_iu->srp.login_rsp.request_limit_delta >
+	    (max_requests - 2))
+		evt_struct->xfer_iu->srp.login_rsp.request_limit_delta =
+		    max_requests - 2;
+
+	/* Now we know what the real request-limit is */
+	atomic_set(&hostdata->request_limit,
+		   evt_struct->xfer_iu->srp.login_rsp.request_limit_delta);
+
+	hostdata->host->can_queue =
+	    evt_struct->xfer_iu->srp.login_rsp.request_limit_delta - 2;
+
+	if (hostdata->host->can_queue < 1) {
+		printk(KERN_ERR "ibmvscsi: Invalid request_limit_delta\n");
+		return;
+	}
+
+	send_mad_adapter_info(hostdata);
+	return;
+}
+
+/**
+ * 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);
+	if (!evt_struct) {
+		printk(KERN_ERR
+		       "ibmvscsi: couldn't allocate an event for login req!\n");
+		return FAILED;
+	}
+
+	init_event_struct(evt_struct,
+			  login_rsp,
+			  VIOSRP_SRP_FORMAT,
+			  init_timeout * HZ);
+
+	login = &evt_struct->iu.srp.login_req;
+	login->type = SRP_LOGIN_REQ_TYPE;
+	login->max_requested_initiator_to_target_iulen = sizeof(union srp_iu);
+	login->required_buffer_formats = 0x0006;
+	
+	/* Start out with a request limit of 1, since this is negotiated in
+	 * the login request we are just sending
+	 */
+	atomic_set(&hostdata->request_limit, 1);
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+	return rc;
+};
+
+/**
+ * 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 =
+	    (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
+	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;
+	u16 lun = lun_from_dev(cmd->device);
+
+	/* First, find this command in our sent list so we can figure
+	 * out the correct tag
+	 */
+	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) 
+		return FAILED;
+
+	evt = get_event_struct(&hostdata->pool);
+	if (evt == NULL) {
+		printk(KERN_ERR "ibmvscsi: failed to allocate abort event\n");
+		return FAILED;
+	}
+	
+	init_event_struct(evt,
+			  sync_completion,
+			  VIOSRP_SRP_FORMAT,
+			  init_timeout * HZ);
+
+	tsk_mgmt = &evt->iu.srp.tsk_mgmt;
+	
+	/* Set up an abort SRP command */
+	memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
+	tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
+	tsk_mgmt->lun = ((u64) lun) << 48;
+	tsk_mgmt->task_mgmt_flags = 0x01;	/* ABORT TASK */
+	tsk_mgmt->managed_task_tag = (u64) found_evt;
+
+	printk(KERN_INFO "ibmvscsi: aborting command. lun 0x%lx, tag 0x%lx\n",
+	       tsk_mgmt->lun, tsk_mgmt->managed_task_tag);
+
+	evt->sync_srp = &srp_rsp;
+	init_completion(&evt->comp);
+	if (ibmvscsi_send_srp_event(evt, hostdata) != 0) {
+		printk(KERN_ERR "ibmvscsi: failed to send abort() event\n");
+		return FAILED;
+	}
+
+	spin_unlock_irq(hostdata->host->host_lock);
+	wait_for_completion(&evt->comp);
+	spin_lock_irq(hostdata->host->host_lock);
+
+	/* make sure we got a good response */
+	if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
+		if (printk_ratelimit())
+			printk(KERN_WARNING 
+			       "ibmvscsi: abort bad SRP RSP type %d\n",
+			       srp_rsp.srp.generic.type);
+		return FAILED;
+	}
+
+	if (srp_rsp.srp.rsp.rspvalid)
+		rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
+	else
+		rsp_rc = srp_rsp.srp.rsp.status;
+
+	if (rsp_rc) {
+		if (printk_ratelimit())
+			printk(KERN_WARNING 
+		       "ibmvscsi: abort code %d for task tag 0x%lx\n",
+			       rsp_rc,
+			       tsk_mgmt->managed_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
+	 */
+	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) {
+		printk(KERN_INFO
+		       "ibmvscsi: aborted task tag 0x%lx completed\n",
+		       tsk_mgmt->managed_task_tag);
+		return SUCCESS;
+	}
+
+	printk(KERN_INFO
+	       "ibmvscsi: successfully aborted task tag 0x%lx\n",
+	       tsk_mgmt->managed_task_tag);
+
+	cmd->result = (DID_ABORT << 16);
+	list_del(&found_evt->list);
+	unmap_cmd_data(&found_evt->iu.srp.cmd, found_evt->hostdata->dev);
+	free_event_struct(&found_evt->hostdata->pool, found_evt);
+	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 =
+	    (struct ibmvscsi_host_data *)cmd->device->host->hostdata;
+
+	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;
+	u16 lun = lun_from_dev(cmd->device);
+
+	evt = get_event_struct(&hostdata->pool);
+	if (evt == NULL) {
+		printk(KERN_ERR "ibmvscsi: failed to allocate reset event\n");
+		return FAILED;
+	}
+	
+	init_event_struct(evt,
+			  sync_completion,
+			  VIOSRP_SRP_FORMAT,
+			  init_timeout * HZ);
+
+	tsk_mgmt = &evt->iu.srp.tsk_mgmt;
+
+	/* Set up a lun reset SRP command */
+	memset(tsk_mgmt, 0x00, sizeof(*tsk_mgmt));
+	tsk_mgmt->type = SRP_TSK_MGMT_TYPE;
+	tsk_mgmt->lun = ((u64) lun) << 48;
+	tsk_mgmt->task_mgmt_flags = 0x08;	/* LUN RESET */
+
+	printk(KERN_INFO "ibmvscsi: resetting device. lun 0x%lx\n",
+	       tsk_mgmt->lun);
+
+	evt->sync_srp = &srp_rsp;
+	init_completion(&evt->comp);
+	if (ibmvscsi_send_srp_event(evt, hostdata) != 0) {
+		printk(KERN_ERR "ibmvscsi: failed to send reset event\n");
+		return FAILED;
+	}
+
+	spin_unlock_irq(hostdata->host->host_lock);
+	wait_for_completion(&evt->comp);
+	spin_lock_irq(hostdata->host->host_lock);
+
+	/* make sure we got a good response */
+	if (unlikely(srp_rsp.srp.generic.type != SRP_RSP_TYPE)) {
+		if (printk_ratelimit())
+			printk(KERN_WARNING 
+			       "ibmvscsi: reset bad SRP RSP type %d\n",
+			       srp_rsp.srp.generic.type);
+		return FAILED;
+	}
+
+	if (srp_rsp.srp.rsp.rspvalid)
+		rsp_rc = *((int *)srp_rsp.srp.rsp.sense_and_response_data);
+	else
+		rsp_rc = srp_rsp.srp.rsp.status;
+
+	if (rsp_rc) {
+		if (printk_ratelimit())
+			printk(KERN_WARNING 
+			       "ibmvscsi: reset code %d for task tag 0x%lx\n",
+		       rsp_rc,
+			       tsk_mgmt->managed_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
+	 */
+	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->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);
+		}
+	}
+	return SUCCESS;
+}
+
+/**
+ * purge_requests: Our virtual adapter just shut down.  purge any sent requests
+ * @hostdata:    the adapter
+ */
+static void purge_requests(struct ibmvscsi_host_data *hostdata)
+{
+	struct srp_event_struct *tmp_evt, *pos;
+	unsigned long flags;
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {
+		list_del(&tmp_evt->list);
+		if (tmp_evt->cmnd) {
+			tmp_evt->cmnd->result = (DID_ERROR << 16);
+			unmap_cmd_data(&tmp_evt->iu.srp.cmd, 
+				       tmp_evt->hostdata->dev);
+			if (tmp_evt->cmnd_done)
+				tmp_evt->cmnd_done(tmp_evt->cmnd);
+		} else {
+			if (tmp_evt->done) {
+				tmp_evt->done(tmp_evt);
+			}
+		}
+		free_event_struct(&tmp_evt->hostdata->pool, tmp_evt);
+	}
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+}
+
+/**
+ * ibmvscsi_handle_crq: - Handles and frees received events in the CRQ
+ * @crq:	Command/Response queue
+ * @hostdata:	ibmvscsi_host_data of host
+ *
+*/
+void ibmvscsi_handle_crq(struct viosrp_crq *crq,
+			 struct ibmvscsi_host_data *hostdata)
+{
+	unsigned long flags;
+	struct srp_event_struct *evt_struct =
+	    (struct srp_event_struct *)crq->IU_data_ptr;
+	switch (crq->valid) {
+	case 0xC0:		/* initialization */
+		switch (crq->format) {
+		case 0x01:	/* Initialization message */
+			printk(KERN_INFO "ibmvscsi: partner initialized\n");
+			/* Send back a response */
+			if (ibmvscsi_send_crq(hostdata,
+					      0xC002000000000000LL, 0) == 0) {
+				/* Now login */
+				send_srp_login(hostdata);
+			} else {
+				printk(KERN_ERR
+				       "ibmvscsi: Unable to send init rsp\n");
+			}
+
+			break;
+		case 0x02:	/* Initialization response */
+			printk(KERN_INFO
+			       "ibmvscsi: partner initialization complete\n");
+
+			/* Now login */
+			send_srp_login(hostdata);
+			break;
+		default:
+			printk(KERN_ERR "ibmvscsi: unknown crq message type\n");
+		}
+		return;
+	case 0xFF:		/* Hypervisor telling us the connection is closed */
+		printk(KERN_INFO "ibmvscsi: Virtual adapter failed!\n");
+
+		atomic_set(&hostdata->request_limit, -1);
+		purge_requests(hostdata);
+		ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
+		return;
+	case 0x80:		/* real payload */
+		break;
+	default:
+		printk(KERN_ERR
+		       "ibmvscsi: 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)) {
+		printk(KERN_ERR
+		       "ibmvscsi: returned correlation_token 0x%p is invalid!\n",
+		       (void *)crq->IU_data_ptr);
+		return;
+	}
+
+	if (atomic_read(&evt_struct->free)) {
+		printk(KERN_ERR
+		       "ibmvscsi: received duplicate  correlation_token 0x%p!\n",
+		       (void *)crq->IU_data_ptr);
+		return;
+	}
+
+	if (crq->format == VIOSRP_SRP_FORMAT)
+		atomic_add(evt_struct->xfer_iu->srp.rsp.request_limit_delta,
+			   &hostdata->request_limit);
+
+	if (evt_struct->done)
+		evt_struct->done(evt_struct);
+	else
+		printk(KERN_ERR
+		       "ibmvscsi: 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_get_host_config: Send the command to the server to get host
+ * configuration data.  The data is opaque to us.
+ */
+static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata,
+				   unsigned char *buffer, int length)
+{
+	struct viosrp_host_config *host_config;
+	struct srp_event_struct *evt_struct;
+	int rc;
+
+	evt_struct = get_event_struct(&hostdata->pool);
+	if (!evt_struct) {
+		printk(KERN_ERR
+		       "ibmvscsi: could't allocate event for HOST_CONFIG!\n");
+		return -1;
+	}
+
+	init_event_struct(evt_struct,
+			  sync_completion,
+			  VIOSRP_MAD_FORMAT,
+			  init_timeout * HZ);
+
+	host_config = &evt_struct->iu.mad.host_config;
+
+	/* Set up a lun reset SRP command */
+	memset(host_config, 0x00, sizeof(*host_config));
+	host_config->common.type = VIOSRP_HOST_CONFIG_TYPE;
+	host_config->common.length = length;
+	host_config->buffer = dma_map_single(hostdata->dev, buffer, length,
+					    DMA_BIDIRECTIONAL);
+
+	if (dma_mapping_error(host_config->buffer)) {
+		printk(KERN_ERR
+		       "ibmvscsi: dma_mapping error " "getting host config\n");
+		free_event_struct(&hostdata->pool, evt_struct);
+		return -1;
+	}
+
+	init_completion(&evt_struct->comp);
+	rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
+	if (rc == 0) {
+		wait_for_completion(&evt_struct->comp);
+		dma_unmap_single(hostdata->dev, host_config->buffer,
+				 length, DMA_BIDIRECTIONAL);
+	}
+
+	return rc;
+}
+
+/* ------------------------------------------------------------
+ * sysfs attributes
+ */
+static ssize_t show_host_srp_version(struct class_device *class_dev, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(class_dev);
+	struct ibmvscsi_host_data *hostdata =
+	    (struct ibmvscsi_host_data *)shost->hostdata;
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "%s\n",
+		       hostdata->madapter_info.srp_version);
+	return len;
+}
+
+static struct class_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 class_device *class_dev,
+					char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(class_dev);
+	struct ibmvscsi_host_data *hostdata =
+	    (struct ibmvscsi_host_data *)shost->hostdata;
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "%s\n",
+		       hostdata->madapter_info.partition_name);
+	return len;
+}
+
+static struct class_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 class_device *class_dev,
+					  char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(class_dev);
+	struct ibmvscsi_host_data *hostdata =
+	    (struct ibmvscsi_host_data *)shost->hostdata;
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "%d\n",
+		       hostdata->madapter_info.partition_number);
+	return len;
+}
+
+static struct class_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 class_device *class_dev, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(class_dev);
+	struct ibmvscsi_host_data *hostdata =
+	    (struct ibmvscsi_host_data *)shost->hostdata;
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "%d\n",
+		       hostdata->madapter_info.mad_version);
+	return len;
+}
+
+static struct class_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 class_device *class_dev, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(class_dev);
+	struct ibmvscsi_host_data *hostdata =
+	    (struct ibmvscsi_host_data *)shost->hostdata;
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "%d\n", hostdata->madapter_info.os_type);
+	return len;
+}
+
+static struct class_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 class_device *class_dev, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(class_dev);
+	struct ibmvscsi_host_data *hostdata =
+	    (struct ibmvscsi_host_data *)shost->hostdata;
+
+	/* returns null-terminated host config data */
+	if (ibmvscsi_do_host_config(hostdata, buf, PAGE_SIZE) == 0)
+		return strlen(buf);
+	else
+		return 0;
+}
+
+static struct class_device_attribute ibmvscsi_host_config = {
+	.attr = {
+		 .name = "config",
+		 .mode = S_IRUGO,
+		 },
+	.show = show_host_config,
+};
+
+static struct class_device_attribute *ibmvscsi_attrs[] = {
+	&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_abort_handler = ibmvscsi_eh_abort_handler,
+	.eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
+	.cmd_per_lun = 16,
+	.can_queue = 1,		/* Updated after SRP_LOGIN */
+	.this_id = -1,
+	.sg_tablesize = MAX_INDIRECT_BUFS,
+	.use_clustering = ENABLE_CLUSTERING,
+	.shost_attrs = ibmvscsi_attrs,
+};
+
+/**
+ * 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;
+	unsigned long wait_switch = 0;
+
+	vdev->dev.driver_data = NULL;
+
+	host = scsi_host_alloc(&driver_template, sizeof(*hostdata));
+	if (!host) {
+		printk(KERN_ERR "ibmvscsi: couldn't allocate host data\n");
+		goto scsi_host_alloc_failed;
+	}
+
+	hostdata = (struct ibmvscsi_host_data *)host->hostdata;
+	memset(hostdata, 0x00, sizeof(*hostdata));
+	INIT_LIST_HEAD(&hostdata->sent);
+	hostdata->host = host;
+	hostdata->dev = dev;
+	atomic_set(&hostdata->request_limit, -1);
+	hostdata->host->max_sectors = 32 * 8; /* default max I/O 32 pages */
+
+	if (ibmvscsi_init_crq_queue(&hostdata->queue, hostdata,
+				    max_requests) != 0) {
+		printk(KERN_ERR "ibmvscsi: couldn't initialize crq\n");
+		goto init_crq_failed;
+	}
+	if (initialize_event_pool(&hostdata->pool, max_requests, hostdata) != 0) {
+		printk(KERN_ERR "ibmvscsi: couldn't initialize event pool\n");
+		goto init_pool_failed;
+	}
+
+	host->max_lun = 8;
+	host->max_id = max_id;
+	host->max_channel = max_channel;
+
+	if (scsi_add_host(hostdata->host, hostdata->dev))
+		goto add_host_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) {
+		/*
+		 * 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);
+	}
+
+	vdev->dev.driver_data = hostdata;
+	return 0;
+
+      add_host_failed:
+	release_event_pool(&hostdata->pool, hostdata);
+      init_pool_failed:
+	ibmvscsi_release_crq_queue(&hostdata->queue, hostdata, max_requests);
+      init_crq_failed:
+	scsi_host_put(host);
+      scsi_host_alloc_failed:
+	return -1;
+}
+
+static int ibmvscsi_remove(struct vio_dev *vdev)
+{
+	struct ibmvscsi_host_data *hostdata = vdev->dev.driver_data;
+	release_event_pool(&hostdata->pool, hostdata);
+	ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
+				   max_requests);
+	
+	scsi_remove_host(hostdata->host);
+	scsi_host_put(hostdata->host);
+
+	return 0;
+}
+
+/**
+ * ibmvscsi_device_table: Used by vio.c to match devices in the device tree we 
+ * support.
+ */
+static struct vio_device_id ibmvscsi_device_table[] __devinitdata = {
+	{"vscsi", "IBM,v-scsi"},
+	{0,}
+};
+
+MODULE_DEVICE_TABLE(vio, ibmvscsi_device_table);
+static struct vio_driver ibmvscsi_driver = {
+	.name = "ibmvscsi",
+	.id_table = ibmvscsi_device_table,
+	.probe = ibmvscsi_probe,
+	.remove = ibmvscsi_remove
+};
+
+int __init ibmvscsi_module_init(void)
+{
+	return vio_register_driver(&ibmvscsi_driver);
+}
+
+void __exit ibmvscsi_module_exit(void)
+{
+	vio_unregister_driver(&ibmvscsi_driver);
+}
+
+module_init(ibmvscsi_module_init);
+module_exit(ibmvscsi_module_exit);