/*
   3w-sas.c -- LSI 3ware SAS/SATA-RAID Controller device driver for Linux.

   Written By: Adam Radford <aradford@gmail.com>

   Copyright (C) 2009 LSI Corporation.

   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; version 2 of the License.

   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.

   NO WARRANTY
   THE PROGRAM IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED INCLUDING, WITHOUT
   LIMITATION, ANY WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT,
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Each Recipient is
   solely responsible for determining the appropriateness of using and
   distributing the Program and assumes all risks associated with its
   exercise of rights under this Agreement, including but not limited to
   the risks and costs of program errors, damage to or loss of data,
   programs or equipment, and unavailability or interruption of operations.

   DISCLAIMER OF LIABILITY
   NEITHER RECIPIENT NOR ANY CONTRIBUTORS SHALL HAVE ANY LIABILITY FOR ANY
   DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS), HOWEVER CAUSED AND
   ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
   TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
   USE OR DISTRIBUTION OF THE PROGRAM OR THE EXERCISE OF ANY RIGHTS GRANTED
   HEREUNDER, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES

   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

   Controllers supported by this driver:

   LSI 3ware 9750 6Gb/s SAS/SATA-RAID

   Bugs/Comments/Suggestions should be mailed to:
   aradford@gmail.com

   History
   -------
   3.26.02.000 - Initial driver release.
*/

#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/moduleparam.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/time.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <linux/uaccess.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_cmnd.h>
#include "3w-sas.h"

/* Globals */
#define TW_DRIVER_VERSION "3.26.02.000"
static DEFINE_MUTEX(twl_chrdev_mutex);
static TW_Device_Extension *twl_device_extension_list[TW_MAX_SLOT];
static unsigned int twl_device_extension_count;
static int twl_major = -1;
extern struct timezone sys_tz;

/* Module parameters */
MODULE_AUTHOR ("LSI");
MODULE_DESCRIPTION ("LSI 3ware SAS/SATA-RAID Linux Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(TW_DRIVER_VERSION);

static int use_msi;
module_param(use_msi, int, S_IRUGO);
MODULE_PARM_DESC(use_msi, "Use Message Signaled Interrupts. Default: 0");

/* Function prototypes */
static int twl_reset_device_extension(TW_Device_Extension *tw_dev, int ioctl_reset);

/* Functions */

/* This function returns AENs through sysfs */
static ssize_t twl_sysfs_aen_read(struct file *filp, struct kobject *kobj,
				  struct bin_attribute *bin_attr,
				  char *outbuf, loff_t offset, size_t count)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct Scsi_Host *shost = class_to_shost(dev);
	TW_Device_Extension *tw_dev = (TW_Device_Extension *)shost->hostdata;
	unsigned long flags = 0;
	ssize_t ret;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;

	spin_lock_irqsave(tw_dev->host->host_lock, flags);
	ret = memory_read_from_buffer(outbuf, count, &offset, tw_dev->event_queue[0], sizeof(TW_Event) * TW_Q_LENGTH);
	spin_unlock_irqrestore(tw_dev->host->host_lock, flags);

	return ret;
} /* End twl_sysfs_aen_read() */

/* aen_read sysfs attribute initializer */
static struct bin_attribute twl_sysfs_aen_read_attr = {
	.attr = {
		.name = "3ware_aen_read",
		.mode = S_IRUSR,
	},
	.size = 0,
	.read = twl_sysfs_aen_read
};

/* This function returns driver compatibility info through sysfs */
static ssize_t twl_sysfs_compat_info(struct file *filp, struct kobject *kobj,
				     struct bin_attribute *bin_attr,
				     char *outbuf, loff_t offset, size_t count)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct Scsi_Host *shost = class_to_shost(dev);
	TW_Device_Extension *tw_dev = (TW_Device_Extension *)shost->hostdata;
	unsigned long flags = 0;
	ssize_t ret;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;

	spin_lock_irqsave(tw_dev->host->host_lock, flags);
	ret = memory_read_from_buffer(outbuf, count, &offset, &tw_dev->tw_compat_info, sizeof(TW_Compatibility_Info));
	spin_unlock_irqrestore(tw_dev->host->host_lock, flags);

	return ret;
} /* End twl_sysfs_compat_info() */

/* compat_info sysfs attribute initializer */
static struct bin_attribute twl_sysfs_compat_info_attr = {
	.attr = {
		.name = "3ware_compat_info",
		.mode = S_IRUSR,
	},
	.size = 0,
	.read = twl_sysfs_compat_info
};

/* Show some statistics about the card */
static ssize_t twl_show_stats(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct Scsi_Host *host = class_to_shost(dev);
	TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;
	unsigned long flags = 0;
	ssize_t len;

	spin_lock_irqsave(tw_dev->host->host_lock, flags);
	len = sysfs_emit(buf, "3w-sas Driver version: %s\n"
			 "Current commands posted:   %4d\n"
			 "Max commands posted:       %4d\n"
			 "Last sgl length:           %4d\n"
			 "Max sgl length:            %4d\n"
			 "Last sector count:         %4d\n"
			 "Max sector count:          %4d\n"
			 "SCSI Host Resets:          %4d\n"
			 "AEN's:                     %4d\n",
			 TW_DRIVER_VERSION,
			 tw_dev->posted_request_count,
			 tw_dev->max_posted_request_count,
			 tw_dev->sgl_entries,
			 tw_dev->max_sgl_entries,
			 tw_dev->sector_count,
			 tw_dev->max_sector_count,
			 tw_dev->num_resets,
			 tw_dev->aen_count);
	spin_unlock_irqrestore(tw_dev->host->host_lock, flags);
	return len;
} /* End twl_show_stats() */

/* stats sysfs attribute initializer */
static struct device_attribute twl_host_stats_attr = {
	.attr = {
		.name =		"3ware_stats",
		.mode =		S_IRUGO,
	},
	.show = twl_show_stats
};

/* Host attributes initializer */
static struct attribute *twl_host_attrs[] = {
	&twl_host_stats_attr.attr,
	NULL,
};

ATTRIBUTE_GROUPS(twl_host);

/* This function will look up an AEN severity string */
static char *twl_aen_severity_lookup(unsigned char severity_code)
{
	char *retval = NULL;

	if ((severity_code < (unsigned char) TW_AEN_SEVERITY_ERROR) ||
	    (severity_code > (unsigned char) TW_AEN_SEVERITY_DEBUG))
		goto out;

	retval = twl_aen_severity_table[severity_code];
out:
	return retval;
} /* End twl_aen_severity_lookup() */

/* This function will queue an event */
static void twl_aen_queue_event(TW_Device_Extension *tw_dev, TW_Command_Apache_Header *header)
{
	u32 local_time;
	TW_Event *event;
	unsigned short aen;
	char host[16];
	char *error_str;

	tw_dev->aen_count++;

	/* Fill out event info */
	event = tw_dev->event_queue[tw_dev->error_index];

	host[0] = '\0';
	if (tw_dev->host)
		sprintf(host, " scsi%d:", tw_dev->host->host_no);

	aen = le16_to_cpu(header->status_block.error);
	memset(event, 0, sizeof(TW_Event));

	event->severity = TW_SEV_OUT(header->status_block.severity__reserved);
	/* event->time_stamp_sec overflows in y2106 */
	local_time = (u32)(ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
	event->time_stamp_sec = local_time;
	event->aen_code = aen;
	event->retrieved = TW_AEN_NOT_RETRIEVED;
	event->sequence_id = tw_dev->error_sequence_id;
	tw_dev->error_sequence_id++;

	/* Check for embedded error string */
	error_str = &(header->err_specific_desc[strlen(header->err_specific_desc)+1]);

	header->err_specific_desc[sizeof(header->err_specific_desc) - 1] = '\0';
	event->parameter_len = strlen(header->err_specific_desc);
	memcpy(event->parameter_data, header->err_specific_desc, event->parameter_len + 1 + strlen(error_str));
	if (event->severity != TW_AEN_SEVERITY_DEBUG)
		printk(KERN_WARNING "3w-sas:%s AEN: %s (0x%02X:0x%04X): %s:%s.\n",
		       host,
		       twl_aen_severity_lookup(TW_SEV_OUT(header->status_block.severity__reserved)),
		       TW_MESSAGE_SOURCE_CONTROLLER_EVENT, aen, error_str,
		       header->err_specific_desc);
	else
		tw_dev->aen_count--;

	tw_dev->error_index = (tw_dev->error_index + 1 ) % TW_Q_LENGTH;
} /* End twl_aen_queue_event() */

/* This function will attempt to post a command packet to the board */
static int twl_post_command_packet(TW_Device_Extension *tw_dev, int request_id)
{
	dma_addr_t command_que_value;

	command_que_value = tw_dev->command_packet_phys[request_id];
	command_que_value += TW_COMMAND_OFFSET;

	/* First write upper 4 bytes */
	writel((u32)((u64)command_que_value >> 32), TWL_HIBQPH_REG_ADDR(tw_dev));
	/* Then the lower 4 bytes */
	writel((u32)(command_que_value | TWL_PULL_MODE), TWL_HIBQPL_REG_ADDR(tw_dev));

	tw_dev->state[request_id] = TW_S_POSTED;
	tw_dev->posted_request_count++;
	if (tw_dev->posted_request_count > tw_dev->max_posted_request_count)
		tw_dev->max_posted_request_count = tw_dev->posted_request_count;

	return 0;
} /* End twl_post_command_packet() */

/* This function hands scsi cdb's to the firmware */
static int twl_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id,
				   unsigned char *cdb, int use_sg,
				   TW_SG_Entry_ISO *sglistarg)
{
	TW_Command_Full *full_command_packet;
	TW_Command_Apache *command_packet;
	int i, sg_count;
	struct scsi_cmnd *srb = NULL;
	struct scatterlist *sg;
	int retval = 1;

	if (tw_dev->srb[request_id])
		srb = tw_dev->srb[request_id];

	/* Initialize command packet */
	full_command_packet = tw_dev->command_packet_virt[request_id];
	full_command_packet->header.header_desc.size_header = 128;
	full_command_packet->header.status_block.error = 0;
	full_command_packet->header.status_block.severity__reserved = 0;

	command_packet = &full_command_packet->command.newcommand;
	command_packet->status = 0;
	command_packet->opcode__reserved = TW_OPRES_IN(0, TW_OP_EXECUTE_SCSI);

	/* We forced 16 byte cdb use earlier */
	if (!cdb)
		memcpy(command_packet->cdb, srb->cmnd, TW_MAX_CDB_LEN);
	else
		memcpy(command_packet->cdb, cdb, TW_MAX_CDB_LEN);

	if (srb) {
		command_packet->unit = srb->device->id;
		command_packet->request_id__lunl =
			cpu_to_le16(TW_REQ_LUN_IN(srb->device->lun, request_id));
	} else {
		command_packet->request_id__lunl =
			cpu_to_le16(TW_REQ_LUN_IN(0, request_id));
		command_packet->unit = 0;
	}

	command_packet->sgl_offset = 16;

	if (!sglistarg) {
		/* Map sglist from scsi layer to cmd packet */
		if (scsi_sg_count(srb)) {
			sg_count = scsi_dma_map(srb);
			if (sg_count <= 0)
				goto out;

			scsi_for_each_sg(srb, sg, sg_count, i) {
				command_packet->sg_list[i].address = TW_CPU_TO_SGL(sg_dma_address(sg));
				command_packet->sg_list[i].length = TW_CPU_TO_SGL(sg_dma_len(sg));
			}
			command_packet->sgl_entries__lunh = cpu_to_le16(TW_REQ_LUN_IN((srb->device->lun >> 4), scsi_sg_count(tw_dev->srb[request_id])));
		}
	} else {
		/* Internal cdb post */
		for (i = 0; i < use_sg; i++) {
			command_packet->sg_list[i].address = TW_CPU_TO_SGL(sglistarg[i].address);
			command_packet->sg_list[i].length = TW_CPU_TO_SGL(sglistarg[i].length);
		}
		command_packet->sgl_entries__lunh = cpu_to_le16(TW_REQ_LUN_IN(0, use_sg));
	}

	/* Update some stats */
	if (srb) {
		tw_dev->sector_count = scsi_bufflen(srb) / 512;
		if (tw_dev->sector_count > tw_dev->max_sector_count)
			tw_dev->max_sector_count = tw_dev->sector_count;
		tw_dev->sgl_entries = scsi_sg_count(srb);
		if (tw_dev->sgl_entries > tw_dev->max_sgl_entries)
			tw_dev->max_sgl_entries = tw_dev->sgl_entries;
	}

	/* Now post the command to the board */
	retval = twl_post_command_packet(tw_dev, request_id);

out:
	return retval;
} /* End twl_scsiop_execute_scsi() */

/* This function will read the aen queue from the isr */
static int twl_aen_read_queue(TW_Device_Extension *tw_dev, int request_id)
{
	unsigned char cdb[TW_MAX_CDB_LEN];
	TW_SG_Entry_ISO sglist[1];
	TW_Command_Full *full_command_packet;
	int retval = 1;

	full_command_packet = tw_dev->command_packet_virt[request_id];
	memset(full_command_packet, 0, sizeof(TW_Command_Full));

	/* Initialize cdb */
	memset(&cdb, 0, TW_MAX_CDB_LEN);
	cdb[0] = REQUEST_SENSE; /* opcode */
	cdb[4] = TW_ALLOCATION_LENGTH; /* allocation length */

	/* Initialize sglist */
	memset(&sglist, 0, sizeof(TW_SG_Entry_ISO));
	sglist[0].length = TW_SECTOR_SIZE;
	sglist[0].address = tw_dev->generic_buffer_phys[request_id];

	/* Mark internal command */
	tw_dev->srb[request_id] = NULL;

	/* Now post the command packet */
	if (twl_scsiop_execute_scsi(tw_dev, request_id, cdb, 1, sglist)) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x2, "Post failed while reading AEN queue");
		goto out;
	}
	retval = 0;
out:
	return retval;
} /* End twl_aen_read_queue() */

/* This function will sync firmware time with the host time */
static void twl_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
{
	u32 schedulertime;
	TW_Command_Full *full_command_packet;
	TW_Command *command_packet;
	TW_Param_Apache *param;
	time64_t local_time;

	/* Fill out the command packet */
	full_command_packet = tw_dev->command_packet_virt[request_id];
	memset(full_command_packet, 0, sizeof(TW_Command_Full));
	command_packet = &full_command_packet->command.oldcommand;
	command_packet->opcode__sgloffset = TW_OPSGL_IN(2, TW_OP_SET_PARAM);
	command_packet->request_id = request_id;
	command_packet->byte8_offset.param.sgl[0].address = TW_CPU_TO_SGL(tw_dev->generic_buffer_phys[request_id]);
	command_packet->byte8_offset.param.sgl[0].length = TW_CPU_TO_SGL(TW_SECTOR_SIZE);
	command_packet->size = TW_COMMAND_SIZE;
	command_packet->byte6_offset.parameter_count = cpu_to_le16(1);

	/* Setup the param */
	param = (TW_Param_Apache *)tw_dev->generic_buffer_virt[request_id];
	memset(param, 0, TW_SECTOR_SIZE);
	param->table_id = cpu_to_le16(TW_TIMEKEEP_TABLE | 0x8000); /* Controller time keep table */
	param->parameter_id = cpu_to_le16(0x3); /* SchedulerTime */
	param->parameter_size_bytes = cpu_to_le16(4);

	/* Convert system time in UTC to local time seconds since last
           Sunday 12:00AM */
	local_time = (ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
	div_u64_rem(local_time - (3 * 86400), 604800, &schedulertime);
	schedulertime = cpu_to_le32(schedulertime);

	memcpy(param->data, &schedulertime, sizeof(u32));

	/* Mark internal command */
	tw_dev->srb[request_id] = NULL;

	/* Now post the command */
	twl_post_command_packet(tw_dev, request_id);
} /* End twl_aen_sync_time() */

/* This function will assign an available request id */
static void twl_get_request_id(TW_Device_Extension *tw_dev, int *request_id)
{
	*request_id = tw_dev->free_queue[tw_dev->free_head];
	tw_dev->free_head = (tw_dev->free_head + 1) % TW_Q_LENGTH;
	tw_dev->state[*request_id] = TW_S_STARTED;
} /* End twl_get_request_id() */

/* This function will free a request id */
static void twl_free_request_id(TW_Device_Extension *tw_dev, int request_id)
{
	tw_dev->free_queue[tw_dev->free_tail] = request_id;
	tw_dev->state[request_id] = TW_S_FINISHED;
	tw_dev->free_tail = (tw_dev->free_tail + 1) % TW_Q_LENGTH;
} /* End twl_free_request_id() */

/* This function will complete an aen request from the isr */
static int twl_aen_complete(TW_Device_Extension *tw_dev, int request_id)
{
	TW_Command_Full *full_command_packet;
	TW_Command *command_packet;
	TW_Command_Apache_Header *header;
	unsigned short aen;
	int retval = 1;

	header = (TW_Command_Apache_Header *)tw_dev->generic_buffer_virt[request_id];
	tw_dev->posted_request_count--;
	aen = le16_to_cpu(header->status_block.error);
	full_command_packet = tw_dev->command_packet_virt[request_id];
	command_packet = &full_command_packet->command.oldcommand;

	/* First check for internal completion of set param for time sync */
	if (TW_OP_OUT(command_packet->opcode__sgloffset) == TW_OP_SET_PARAM) {
		/* Keep reading the queue in case there are more aen's */
		if (twl_aen_read_queue(tw_dev, request_id))
			goto out2;
		else {
			retval = 0;
			goto out;
		}
	}

	switch (aen) {
	case TW_AEN_QUEUE_EMPTY:
		/* Quit reading the queue if this is the last one */
		break;
	case TW_AEN_SYNC_TIME_WITH_HOST:
		twl_aen_sync_time(tw_dev, request_id);
		retval = 0;
		goto out;
	default:
		twl_aen_queue_event(tw_dev, header);

		/* If there are more aen's, keep reading the queue */
		if (twl_aen_read_queue(tw_dev, request_id))
			goto out2;
		else {
			retval = 0;
			goto out;
		}
	}
	retval = 0;
out2:
	tw_dev->state[request_id] = TW_S_COMPLETED;
	twl_free_request_id(tw_dev, request_id);
	clear_bit(TW_IN_ATTENTION_LOOP, &tw_dev->flags);
out:
	return retval;
} /* End twl_aen_complete() */

/* This function will poll for a response */
static int twl_poll_response(TW_Device_Extension *tw_dev, int request_id, int seconds)
{
	unsigned long before;
	dma_addr_t mfa;
	u32 regh, regl;
	u32 response;
	int retval = 1;
	int found = 0;

	before = jiffies;

	while (!found) {
		if (sizeof(dma_addr_t) > 4) {
			regh = readl(TWL_HOBQPH_REG_ADDR(tw_dev));
			regl = readl(TWL_HOBQPL_REG_ADDR(tw_dev));
			mfa = ((u64)regh << 32) | regl;
		} else
			mfa = readl(TWL_HOBQPL_REG_ADDR(tw_dev));

		response = (u32)mfa;

		if (TW_RESID_OUT(response) == request_id)
			found = 1;

		if (time_after(jiffies, before + HZ * seconds))
			goto out;

		msleep(50);
	}
	retval = 0;
out:
	return retval;
} /* End twl_poll_response() */

/* This function will drain the aen queue */
static int twl_aen_drain_queue(TW_Device_Extension *tw_dev, int no_check_reset)
{
	int request_id = 0;
	unsigned char cdb[TW_MAX_CDB_LEN];
	TW_SG_Entry_ISO sglist[1];
	int finished = 0, count = 0;
	TW_Command_Full *full_command_packet;
	TW_Command_Apache_Header *header;
	unsigned short aen;
	int first_reset = 0, queue = 0, retval = 1;

	if (no_check_reset)
		first_reset = 0;
	else
		first_reset = 1;

	full_command_packet = tw_dev->command_packet_virt[request_id];
	memset(full_command_packet, 0, sizeof(TW_Command_Full));

	/* Initialize cdb */
	memset(&cdb, 0, TW_MAX_CDB_LEN);
	cdb[0] = REQUEST_SENSE; /* opcode */
	cdb[4] = TW_ALLOCATION_LENGTH; /* allocation length */

	/* Initialize sglist */
	memset(&sglist, 0, sizeof(TW_SG_Entry_ISO));
	sglist[0].length = TW_SECTOR_SIZE;
	sglist[0].address = tw_dev->generic_buffer_phys[request_id];

	/* Mark internal command */
	tw_dev->srb[request_id] = NULL;

	do {
		/* Send command to the board */
		if (twl_scsiop_execute_scsi(tw_dev, request_id, cdb, 1, sglist)) {
			TW_PRINTK(tw_dev->host, TW_DRIVER, 0x3, "Error posting request sense");
			goto out;
		}

		/* Now poll for completion */
		if (twl_poll_response(tw_dev, request_id, 30)) {
			TW_PRINTK(tw_dev->host, TW_DRIVER, 0x4, "No valid response while draining AEN queue");
			tw_dev->posted_request_count--;
			goto out;
		}

		tw_dev->posted_request_count--;
		header = (TW_Command_Apache_Header *)tw_dev->generic_buffer_virt[request_id];
		aen = le16_to_cpu(header->status_block.error);
		queue = 0;
		count++;

		switch (aen) {
		case TW_AEN_QUEUE_EMPTY:
			if (first_reset != 1)
				goto out;
			else
				finished = 1;
			break;
		case TW_AEN_SOFT_RESET:
			if (first_reset == 0)
				first_reset = 1;
			else
				queue = 1;
			break;
		case TW_AEN_SYNC_TIME_WITH_HOST:
			break;
		default:
			queue = 1;
		}

		/* Now queue an event info */
		if (queue)
			twl_aen_queue_event(tw_dev, header);
	} while ((finished == 0) && (count < TW_MAX_AEN_DRAIN));

	if (count == TW_MAX_AEN_DRAIN)
		goto out;

	retval = 0;
out:
	tw_dev->state[request_id] = TW_S_INITIAL;
	return retval;
} /* End twl_aen_drain_queue() */

/* This function will allocate memory and check if it is correctly aligned */
static int twl_allocate_memory(TW_Device_Extension *tw_dev, int size, int which)
{
	int i;
	dma_addr_t dma_handle;
	unsigned long *cpu_addr;
	int retval = 1;

	cpu_addr = dma_alloc_coherent(&tw_dev->tw_pci_dev->dev,
				      size * TW_Q_LENGTH, &dma_handle,
				      GFP_KERNEL);
	if (!cpu_addr) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x5, "Memory allocation failed");
		goto out;
	}

	for (i = 0; i < TW_Q_LENGTH; i++) {
		switch(which) {
		case 0:
			tw_dev->command_packet_phys[i] = dma_handle+(i*size);
			tw_dev->command_packet_virt[i] = (TW_Command_Full *)((unsigned char *)cpu_addr + (i*size));
			break;
		case 1:
			tw_dev->generic_buffer_phys[i] = dma_handle+(i*size);
			tw_dev->generic_buffer_virt[i] = (unsigned long *)((unsigned char *)cpu_addr + (i*size));
			break;
		case 2:
			tw_dev->sense_buffer_phys[i] = dma_handle+(i*size);
			tw_dev->sense_buffer_virt[i] = (TW_Command_Apache_Header *)((unsigned char *)cpu_addr + (i*size));
			break;
		}
	}
	retval = 0;
out:
	return retval;
} /* End twl_allocate_memory() */

/* This function will load the request id and various sgls for ioctls */
static void twl_load_sgl(TW_Device_Extension *tw_dev, TW_Command_Full *full_command_packet, int request_id, dma_addr_t dma_handle, int length)
{
	TW_Command *oldcommand;
	TW_Command_Apache *newcommand;
	TW_SG_Entry_ISO *sgl;
	unsigned int pae = 0;

	if ((sizeof(long) < 8) && (sizeof(dma_addr_t) > 4))
		pae = 1;

	if (TW_OP_OUT(full_command_packet->command.newcommand.opcode__reserved) == TW_OP_EXECUTE_SCSI) {
		newcommand = &full_command_packet->command.newcommand;
		newcommand->request_id__lunl =
			cpu_to_le16(TW_REQ_LUN_IN(TW_LUN_OUT(newcommand->request_id__lunl), request_id));
		if (length) {
			newcommand->sg_list[0].address = TW_CPU_TO_SGL(dma_handle + sizeof(TW_Ioctl_Buf_Apache));
			newcommand->sg_list[0].length = TW_CPU_TO_SGL(length);
		}
		newcommand->sgl_entries__lunh =
			cpu_to_le16(TW_REQ_LUN_IN(TW_LUN_OUT(newcommand->sgl_entries__lunh), length ? 1 : 0));
	} else {
		oldcommand = &full_command_packet->command.oldcommand;
		oldcommand->request_id = request_id;

		if (TW_SGL_OUT(oldcommand->opcode__sgloffset)) {
			/* Load the sg list */
			sgl = (TW_SG_Entry_ISO *)((u32 *)oldcommand+oldcommand->size - (sizeof(TW_SG_Entry_ISO)/4) + pae + (sizeof(dma_addr_t) > 4 ? 1 : 0));
			sgl->address = TW_CPU_TO_SGL(dma_handle + sizeof(TW_Ioctl_Buf_Apache));
			sgl->length = TW_CPU_TO_SGL(length);
			oldcommand->size += pae;
			oldcommand->size += sizeof(dma_addr_t) > 4 ? 1 : 0;
		}
	}
} /* End twl_load_sgl() */

/* This function handles ioctl for the character device
   This interface is used by smartmontools open source software */
static long twl_chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	long timeout;
	unsigned long *cpu_addr, data_buffer_length_adjusted = 0, flags = 0;
	dma_addr_t dma_handle;
	int request_id = 0;
	TW_Ioctl_Driver_Command driver_command;
	struct inode *inode = file_inode(file);
	TW_Ioctl_Buf_Apache *tw_ioctl;
	TW_Command_Full *full_command_packet;
	TW_Device_Extension *tw_dev = twl_device_extension_list[iminor(inode)];
	int retval = -EFAULT;
	void __user *argp = (void __user *)arg;

	mutex_lock(&twl_chrdev_mutex);

	/* Only let one of these through at a time */
	if (mutex_lock_interruptible(&tw_dev->ioctl_lock)) {
		retval = -EINTR;
		goto out;
	}

	/* First copy down the driver command */
	if (copy_from_user(&driver_command, argp, sizeof(TW_Ioctl_Driver_Command)))
		goto out2;

	/* Check data buffer size */
	if (driver_command.buffer_length > TW_MAX_SECTORS * 2048) {
		retval = -EINVAL;
		goto out2;
	}

	/* Hardware can only do multiple of 512 byte transfers */
	data_buffer_length_adjusted = (driver_command.buffer_length + 511) & ~511;

	/* Now allocate ioctl buf memory */
	cpu_addr = dma_alloc_coherent(&tw_dev->tw_pci_dev->dev, data_buffer_length_adjusted + sizeof(TW_Ioctl_Buf_Apache), &dma_handle, GFP_KERNEL);
	if (!cpu_addr) {
		retval = -ENOMEM;
		goto out2;
	}

	tw_ioctl = (TW_Ioctl_Buf_Apache *)cpu_addr;

	/* Now copy down the entire ioctl */
	if (copy_from_user(tw_ioctl, argp, driver_command.buffer_length + sizeof(TW_Ioctl_Buf_Apache)))
		goto out3;

	/* See which ioctl we are doing */
	switch (cmd) {
	case TW_IOCTL_FIRMWARE_PASS_THROUGH:
		spin_lock_irqsave(tw_dev->host->host_lock, flags);
		twl_get_request_id(tw_dev, &request_id);

		/* Flag internal command */
		tw_dev->srb[request_id] = NULL;

		/* Flag chrdev ioctl */
		tw_dev->chrdev_request_id = request_id;

		full_command_packet = (TW_Command_Full *)&tw_ioctl->firmware_command;

		/* Load request id and sglist for both command types */
		twl_load_sgl(tw_dev, full_command_packet, request_id, dma_handle, data_buffer_length_adjusted);

		memcpy(tw_dev->command_packet_virt[request_id], &(tw_ioctl->firmware_command), sizeof(TW_Command_Full));

		/* Now post the command packet to the controller */
		twl_post_command_packet(tw_dev, request_id);
		spin_unlock_irqrestore(tw_dev->host->host_lock, flags);

		timeout = TW_IOCTL_CHRDEV_TIMEOUT*HZ;

		/* Now wait for command to complete */
		timeout = wait_event_timeout(tw_dev->ioctl_wqueue, tw_dev->chrdev_request_id == TW_IOCTL_CHRDEV_FREE, timeout);

		/* We timed out, and didn't get an interrupt */
		if (tw_dev->chrdev_request_id != TW_IOCTL_CHRDEV_FREE) {
			/* Now we need to reset the board */
			printk(KERN_WARNING "3w-sas: scsi%d: WARNING: (0x%02X:0x%04X): Character ioctl (0x%x) timed out, resetting card.\n",
			       tw_dev->host->host_no, TW_DRIVER, 0x6,
			       cmd);
			retval = -EIO;
			twl_reset_device_extension(tw_dev, 1);
			goto out3;
		}

		/* Now copy in the command packet response */
		memcpy(&(tw_ioctl->firmware_command), tw_dev->command_packet_virt[request_id], sizeof(TW_Command_Full));

		/* Now complete the io */
		spin_lock_irqsave(tw_dev->host->host_lock, flags);
		tw_dev->posted_request_count--;
		tw_dev->state[request_id] = TW_S_COMPLETED;
		twl_free_request_id(tw_dev, request_id);
		spin_unlock_irqrestore(tw_dev->host->host_lock, flags);
		break;
	default:
		retval = -ENOTTY;
		goto out3;
	}

	/* Now copy the entire response to userspace */
	if (copy_to_user(argp, tw_ioctl, sizeof(TW_Ioctl_Buf_Apache) + driver_command.buffer_length) == 0)
		retval = 0;
out3:
	/* Now free ioctl buf memory */
	dma_free_coherent(&tw_dev->tw_pci_dev->dev, data_buffer_length_adjusted + sizeof(TW_Ioctl_Buf_Apache), cpu_addr, dma_handle);
out2:
	mutex_unlock(&tw_dev->ioctl_lock);
out:
	mutex_unlock(&twl_chrdev_mutex);
	return retval;
} /* End twl_chrdev_ioctl() */

/* This function handles open for the character device */
static int twl_chrdev_open(struct inode *inode, struct file *file)
{
	unsigned int minor_number;
	int retval = -ENODEV;

	if (!capable(CAP_SYS_ADMIN)) {
		retval = -EACCES;
		goto out;
	}

	minor_number = iminor(inode);
	if (minor_number >= twl_device_extension_count)
		goto out;
	retval = 0;
out:
	return retval;
} /* End twl_chrdev_open() */

/* File operations struct for character device */
static const struct file_operations twl_fops = {
	.owner		= THIS_MODULE,
	.unlocked_ioctl	= twl_chrdev_ioctl,
	.open		= twl_chrdev_open,
	.release	= NULL,
	.llseek		= noop_llseek,
};

/* This function passes sense data from firmware to scsi layer */
static int twl_fill_sense(TW_Device_Extension *tw_dev, int i, int request_id, int copy_sense, int print_host)
{
	TW_Command_Apache_Header *header;
	TW_Command_Full *full_command_packet;
	unsigned short error;
	char *error_str;

	header = tw_dev->sense_buffer_virt[i];
	full_command_packet = tw_dev->command_packet_virt[request_id];

	/* Get embedded firmware error string */
	error_str = &(header->err_specific_desc[strlen(header->err_specific_desc) + 1]);

	/* Don't print error for Logical unit not supported during rollcall */
	error = le16_to_cpu(header->status_block.error);
	if ((error != TW_ERROR_LOGICAL_UNIT_NOT_SUPPORTED) && (error != TW_ERROR_UNIT_OFFLINE) && (error != TW_ERROR_INVALID_FIELD_IN_CDB)) {
		if (print_host)
			printk(KERN_WARNING "3w-sas: scsi%d: ERROR: (0x%02X:0x%04X): %s:%s.\n",
			       tw_dev->host->host_no,
			       TW_MESSAGE_SOURCE_CONTROLLER_ERROR,
			       header->status_block.error,
			       error_str,
			       header->err_specific_desc);
		else
			printk(KERN_WARNING "3w-sas: ERROR: (0x%02X:0x%04X): %s:%s.\n",
			       TW_MESSAGE_SOURCE_CONTROLLER_ERROR,
			       header->status_block.error,
			       error_str,
			       header->err_specific_desc);
	}

	if (copy_sense) {
		memcpy(tw_dev->srb[request_id]->sense_buffer, header->sense_data, TW_SENSE_DATA_LENGTH);
		tw_dev->srb[request_id]->result = (full_command_packet->command.newcommand.status << 1);
		goto out;
	}
out:
	return 1;
} /* End twl_fill_sense() */

/* This function will free up device extension resources */
static void twl_free_device_extension(TW_Device_Extension *tw_dev)
{
	if (tw_dev->command_packet_virt[0])
		dma_free_coherent(&tw_dev->tw_pci_dev->dev,
				    sizeof(TW_Command_Full)*TW_Q_LENGTH,
				    tw_dev->command_packet_virt[0],
				    tw_dev->command_packet_phys[0]);

	if (tw_dev->generic_buffer_virt[0])
		dma_free_coherent(&tw_dev->tw_pci_dev->dev,
				    TW_SECTOR_SIZE*TW_Q_LENGTH,
				    tw_dev->generic_buffer_virt[0],
				    tw_dev->generic_buffer_phys[0]);

	if (tw_dev->sense_buffer_virt[0])
		dma_free_coherent(&tw_dev->tw_pci_dev->dev,
				    sizeof(TW_Command_Apache_Header)*
				    TW_Q_LENGTH,
				    tw_dev->sense_buffer_virt[0],
				    tw_dev->sense_buffer_phys[0]);

	kfree(tw_dev->event_queue[0]);
} /* End twl_free_device_extension() */

/* This function will get parameter table entries from the firmware */
static void *twl_get_param(TW_Device_Extension *tw_dev, int request_id, int table_id, int parameter_id, int parameter_size_bytes)
{
	TW_Command_Full *full_command_packet;
	TW_Command *command_packet;
	TW_Param_Apache *param;
	void *retval = NULL;

	/* Setup the command packet */
	full_command_packet = tw_dev->command_packet_virt[request_id];
	memset(full_command_packet, 0, sizeof(TW_Command_Full));
	command_packet = &full_command_packet->command.oldcommand;

	command_packet->opcode__sgloffset = TW_OPSGL_IN(2, TW_OP_GET_PARAM);
	command_packet->size		  = TW_COMMAND_SIZE;
	command_packet->request_id	  = request_id;
	command_packet->byte6_offset.block_count = cpu_to_le16(1);

	/* Now setup the param */
	param = (TW_Param_Apache *)tw_dev->generic_buffer_virt[request_id];
	memset(param, 0, TW_SECTOR_SIZE);
	param->table_id = cpu_to_le16(table_id | 0x8000);
	param->parameter_id = cpu_to_le16(parameter_id);
	param->parameter_size_bytes = cpu_to_le16(parameter_size_bytes);

	command_packet->byte8_offset.param.sgl[0].address = TW_CPU_TO_SGL(tw_dev->generic_buffer_phys[request_id]);
	command_packet->byte8_offset.param.sgl[0].length = TW_CPU_TO_SGL(TW_SECTOR_SIZE);

	/* Post the command packet to the board */
	twl_post_command_packet(tw_dev, request_id);

	/* Poll for completion */
	if (twl_poll_response(tw_dev, request_id, 30))
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x7, "No valid response during get param")
	else
		retval = (void *)&(param->data[0]);

	tw_dev->posted_request_count--;
	tw_dev->state[request_id] = TW_S_INITIAL;

	return retval;
} /* End twl_get_param() */

/* This function will send an initconnection command to controller */
static int twl_initconnection(TW_Device_Extension *tw_dev, int message_credits,
			      u32 set_features, unsigned short current_fw_srl,
			      unsigned short current_fw_arch_id,
			      unsigned short current_fw_branch,
			      unsigned short current_fw_build,
			      unsigned short *fw_on_ctlr_srl,
			      unsigned short *fw_on_ctlr_arch_id,
			      unsigned short *fw_on_ctlr_branch,
			      unsigned short *fw_on_ctlr_build,
			      u32 *init_connect_result)
{
	TW_Command_Full *full_command_packet;
	TW_Initconnect *tw_initconnect;
	int request_id = 0, retval = 1;

	/* Initialize InitConnection command packet */
	full_command_packet = tw_dev->command_packet_virt[request_id];
	memset(full_command_packet, 0, sizeof(TW_Command_Full));
	full_command_packet->header.header_desc.size_header = 128;

	tw_initconnect = (TW_Initconnect *)&full_command_packet->command.oldcommand;
	tw_initconnect->opcode__reserved = TW_OPRES_IN(0, TW_OP_INIT_CONNECTION);
	tw_initconnect->request_id = request_id;
	tw_initconnect->message_credits = cpu_to_le16(message_credits);
	tw_initconnect->features = set_features;

	/* Turn on 64-bit sgl support if we need to */
	tw_initconnect->features |= sizeof(dma_addr_t) > 4 ? 1 : 0;

	tw_initconnect->features = cpu_to_le32(tw_initconnect->features);

	if (set_features & TW_EXTENDED_INIT_CONNECT) {
		tw_initconnect->size = TW_INIT_COMMAND_PACKET_SIZE_EXTENDED;
		tw_initconnect->fw_srl = cpu_to_le16(current_fw_srl);
		tw_initconnect->fw_arch_id = cpu_to_le16(current_fw_arch_id);
		tw_initconnect->fw_branch = cpu_to_le16(current_fw_branch);
		tw_initconnect->fw_build = cpu_to_le16(current_fw_build);
	} else
		tw_initconnect->size = TW_INIT_COMMAND_PACKET_SIZE;

	/* Send command packet to the board */
	twl_post_command_packet(tw_dev, request_id);

	/* Poll for completion */
	if (twl_poll_response(tw_dev, request_id, 30)) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x8, "No valid response during init connection");
	} else {
		if (set_features & TW_EXTENDED_INIT_CONNECT) {
			*fw_on_ctlr_srl = le16_to_cpu(tw_initconnect->fw_srl);
			*fw_on_ctlr_arch_id = le16_to_cpu(tw_initconnect->fw_arch_id);
			*fw_on_ctlr_branch = le16_to_cpu(tw_initconnect->fw_branch);
			*fw_on_ctlr_build = le16_to_cpu(tw_initconnect->fw_build);
			*init_connect_result = le32_to_cpu(tw_initconnect->result);
		}
		retval = 0;
	}

	tw_dev->posted_request_count--;
	tw_dev->state[request_id] = TW_S_INITIAL;

	return retval;
} /* End twl_initconnection() */

/* This function will initialize the fields of a device extension */
static int twl_initialize_device_extension(TW_Device_Extension *tw_dev)
{
	int i, retval = 1;

	/* Initialize command packet buffers */
	if (twl_allocate_memory(tw_dev, sizeof(TW_Command_Full), 0)) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x9, "Command packet memory allocation failed");
		goto out;
	}

	/* Initialize generic buffer */
	if (twl_allocate_memory(tw_dev, TW_SECTOR_SIZE, 1)) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0xa, "Generic memory allocation failed");
		goto out;
	}

	/* Allocate sense buffers */
	if (twl_allocate_memory(tw_dev, sizeof(TW_Command_Apache_Header), 2)) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0xb, "Sense buffer allocation failed");
		goto out;
	}

	/* Allocate event info space */
	tw_dev->event_queue[0] = kcalloc(TW_Q_LENGTH, sizeof(TW_Event), GFP_KERNEL);
	if (!tw_dev->event_queue[0]) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0xc, "Event info memory allocation failed");
		goto out;
	}

	for (i = 0; i < TW_Q_LENGTH; i++) {
		tw_dev->event_queue[i] = (TW_Event *)((unsigned char *)tw_dev->event_queue[0] + (i * sizeof(TW_Event)));
		tw_dev->free_queue[i] = i;
		tw_dev->state[i] = TW_S_INITIAL;
	}

	tw_dev->free_head = TW_Q_START;
	tw_dev->free_tail = TW_Q_START;
	tw_dev->error_sequence_id = 1;
	tw_dev->chrdev_request_id = TW_IOCTL_CHRDEV_FREE;

	mutex_init(&tw_dev->ioctl_lock);
	init_waitqueue_head(&tw_dev->ioctl_wqueue);

	retval = 0;
out:
	return retval;
} /* End twl_initialize_device_extension() */

/* This function will handle attention interrupts */
static int twl_handle_attention_interrupt(TW_Device_Extension *tw_dev)
{
	int retval = 1;
	u32 request_id, doorbell;

	/* Read doorbell status */
	doorbell = readl(TWL_HOBDB_REG_ADDR(tw_dev));

	/* Check for controller errors */
	if (doorbell & TWL_DOORBELL_CONTROLLER_ERROR) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0xd, "Microcontroller Error: clearing");
		goto out;
	}

	/* Check if we need to perform an AEN drain */
	if (doorbell & TWL_DOORBELL_ATTENTION_INTERRUPT) {
		if (!(test_and_set_bit(TW_IN_ATTENTION_LOOP, &tw_dev->flags))) {
			twl_get_request_id(tw_dev, &request_id);
			if (twl_aen_read_queue(tw_dev, request_id)) {
				tw_dev->state[request_id] = TW_S_COMPLETED;
				twl_free_request_id(tw_dev, request_id);
				clear_bit(TW_IN_ATTENTION_LOOP, &tw_dev->flags);
			}
		}
	}

	retval = 0;
out:
	/* Clear doorbell interrupt */
	TWL_CLEAR_DB_INTERRUPT(tw_dev);

	/* Make sure the clear was flushed by reading it back */
	readl(TWL_HOBDBC_REG_ADDR(tw_dev));

	return retval;
} /* End twl_handle_attention_interrupt() */

/* Interrupt service routine */
static irqreturn_t twl_interrupt(int irq, void *dev_instance)
{
	TW_Device_Extension *tw_dev = (TW_Device_Extension *)dev_instance;
	int i, handled = 0, error = 0;
	dma_addr_t mfa = 0;
	u32 reg, regl, regh, response, request_id = 0;
	struct scsi_cmnd *cmd;
	TW_Command_Full *full_command_packet;

	spin_lock(tw_dev->host->host_lock);

	/* Read host interrupt status */
	reg = readl(TWL_HISTAT_REG_ADDR(tw_dev));

	/* Check if this is our interrupt, otherwise bail */
	if (!(reg & TWL_HISTATUS_VALID_INTERRUPT))
		goto twl_interrupt_bail;

	handled = 1;

	/* If we are resetting, bail */
	if (test_bit(TW_IN_RESET, &tw_dev->flags))
		goto twl_interrupt_bail;

	/* Attention interrupt */
	if (reg & TWL_HISTATUS_ATTENTION_INTERRUPT) {
		if (twl_handle_attention_interrupt(tw_dev)) {
			TWL_MASK_INTERRUPTS(tw_dev);
			goto twl_interrupt_bail;
		}
	}

	/* Response interrupt */
	while (reg & TWL_HISTATUS_RESPONSE_INTERRUPT) {
		if (sizeof(dma_addr_t) > 4) {
			regh = readl(TWL_HOBQPH_REG_ADDR(tw_dev));
			regl = readl(TWL_HOBQPL_REG_ADDR(tw_dev));
			mfa = ((u64)regh << 32) | regl;
		} else
			mfa = readl(TWL_HOBQPL_REG_ADDR(tw_dev));

		error = 0;
		response = (u32)mfa;

		/* Check for command packet error */
		if (!TW_NOTMFA_OUT(response)) {
			for (i=0;i<TW_Q_LENGTH;i++) {
				if (tw_dev->sense_buffer_phys[i] == mfa) {
					request_id = le16_to_cpu(tw_dev->sense_buffer_virt[i]->header_desc.request_id);
					if (tw_dev->srb[request_id] != NULL)
						error = twl_fill_sense(tw_dev, i, request_id, 1, 1);
					else {
						/* Skip ioctl error prints */
						if (request_id != tw_dev->chrdev_request_id)
							error = twl_fill_sense(tw_dev, i, request_id, 0, 1);
						else
							memcpy(tw_dev->command_packet_virt[request_id], tw_dev->sense_buffer_virt[i], sizeof(TW_Command_Apache_Header));
					}

					/* Now re-post the sense buffer */
					writel((u32)((u64)tw_dev->sense_buffer_phys[i] >> 32), TWL_HOBQPH_REG_ADDR(tw_dev));
					writel((u32)tw_dev->sense_buffer_phys[i], TWL_HOBQPL_REG_ADDR(tw_dev));
					break;
				}
			}
		} else
			request_id = TW_RESID_OUT(response);

		full_command_packet = tw_dev->command_packet_virt[request_id];

		/* Check for correct state */
		if (tw_dev->state[request_id] != TW_S_POSTED) {
			if (tw_dev->srb[request_id] != NULL) {
				TW_PRINTK(tw_dev->host, TW_DRIVER, 0xe, "Received a request id that wasn't posted");
				TWL_MASK_INTERRUPTS(tw_dev);
				goto twl_interrupt_bail;
			}
		}

		/* Check for internal command completion */
		if (tw_dev->srb[request_id] == NULL) {
			if (request_id != tw_dev->chrdev_request_id) {
				if (twl_aen_complete(tw_dev, request_id))
					TW_PRINTK(tw_dev->host, TW_DRIVER, 0xf, "Error completing AEN during attention interrupt");
			} else {
				tw_dev->chrdev_request_id = TW_IOCTL_CHRDEV_FREE;
				wake_up(&tw_dev->ioctl_wqueue);
			}
		} else {
			cmd = tw_dev->srb[request_id];

			if (!error)
				cmd->result = (DID_OK << 16);

			/* Report residual bytes for single sgl */
			if ((scsi_sg_count(cmd) <= 1) && (full_command_packet->command.newcommand.status == 0)) {
				if (full_command_packet->command.newcommand.sg_list[0].length < scsi_bufflen(tw_dev->srb[request_id]))
					scsi_set_resid(cmd, scsi_bufflen(cmd) - full_command_packet->command.newcommand.sg_list[0].length);
			}

			/* Now complete the io */
			scsi_dma_unmap(cmd);
			scsi_done(cmd);
			tw_dev->state[request_id] = TW_S_COMPLETED;
			twl_free_request_id(tw_dev, request_id);
			tw_dev->posted_request_count--;
		}

		/* Check for another response interrupt */
		reg = readl(TWL_HISTAT_REG_ADDR(tw_dev));
	}

twl_interrupt_bail:
	spin_unlock(tw_dev->host->host_lock);
	return IRQ_RETVAL(handled);
} /* End twl_interrupt() */

/* This function will poll for a register change */
static int twl_poll_register(TW_Device_Extension *tw_dev, void *reg, u32 value, u32 result, int seconds)
{
	unsigned long before;
	int retval = 1;
	u32 reg_value;

	reg_value = readl(reg);
	before = jiffies;

	while ((reg_value & value) != result) {
		reg_value = readl(reg);
		if (time_after(jiffies, before + HZ * seconds))
			goto out;
		msleep(50);
	}
	retval = 0;
out:
	return retval;
} /* End twl_poll_register() */

/* This function will reset a controller */
static int twl_reset_sequence(TW_Device_Extension *tw_dev, int soft_reset)
{
	int retval = 1;
	int i = 0;
	u32 status = 0;
	unsigned short fw_on_ctlr_srl = 0, fw_on_ctlr_arch_id = 0;
	unsigned short fw_on_ctlr_branch = 0, fw_on_ctlr_build = 0;
	u32 init_connect_result = 0;
	int tries = 0;
	int do_soft_reset = soft_reset;

	while (tries < TW_MAX_RESET_TRIES) {
		/* Do a soft reset if one is needed */
		if (do_soft_reset) {
			TWL_SOFT_RESET(tw_dev);

			/* Make sure controller is in a good state */
			if (twl_poll_register(tw_dev, TWL_SCRPD3_REG_ADDR(tw_dev), TWL_CONTROLLER_READY, 0x0, 30)) {
				TW_PRINTK(tw_dev->host, TW_DRIVER, 0x10, "Controller never went non-ready during reset sequence");
				tries++;
				continue;
			}
			if (twl_poll_register(tw_dev, TWL_SCRPD3_REG_ADDR(tw_dev), TWL_CONTROLLER_READY, TWL_CONTROLLER_READY, 60)) {
				TW_PRINTK(tw_dev->host, TW_DRIVER, 0x11, "Controller not ready during reset sequence");
				tries++;
				continue;
			}
		}

		/* Initconnect */
		if (twl_initconnection(tw_dev, TW_INIT_MESSAGE_CREDITS,
				       TW_EXTENDED_INIT_CONNECT, TW_CURRENT_DRIVER_SRL,
				       TW_9750_ARCH_ID, TW_CURRENT_DRIVER_BRANCH,
				       TW_CURRENT_DRIVER_BUILD, &fw_on_ctlr_srl,
				       &fw_on_ctlr_arch_id, &fw_on_ctlr_branch,
				       &fw_on_ctlr_build, &init_connect_result)) {
			TW_PRINTK(tw_dev->host, TW_DRIVER, 0x12, "Initconnection failed while checking SRL");
			do_soft_reset = 1;
			tries++;
			continue;
		}

		/* Load sense buffers */
		while (i < TW_Q_LENGTH) {
			writel((u32)((u64)tw_dev->sense_buffer_phys[i] >> 32), TWL_HOBQPH_REG_ADDR(tw_dev));
			writel((u32)tw_dev->sense_buffer_phys[i], TWL_HOBQPL_REG_ADDR(tw_dev));

			/* Check status for over-run after each write */
			status = readl(TWL_STATUS_REG_ADDR(tw_dev));
			if (!(status & TWL_STATUS_OVERRUN_SUBMIT))
			    i++;
		}

		/* Now check status */
		status = readl(TWL_STATUS_REG_ADDR(tw_dev));
		if (status) {
			TW_PRINTK(tw_dev->host, TW_DRIVER, 0x13, "Bad controller status after loading sense buffers");
			do_soft_reset = 1;
			tries++;
			continue;
		}

		/* Drain the AEN queue */
		if (twl_aen_drain_queue(tw_dev, soft_reset)) {
			TW_PRINTK(tw_dev->host, TW_DRIVER, 0x14, "AEN drain failed during reset sequence");
			do_soft_reset = 1;
			tries++;
			continue;
		}

		/* Load rest of compatibility struct */
		strscpy(tw_dev->tw_compat_info.driver_version, TW_DRIVER_VERSION,
			sizeof(tw_dev->tw_compat_info.driver_version));
		tw_dev->tw_compat_info.driver_srl_high = TW_CURRENT_DRIVER_SRL;
		tw_dev->tw_compat_info.driver_branch_high = TW_CURRENT_DRIVER_BRANCH;
		tw_dev->tw_compat_info.driver_build_high = TW_CURRENT_DRIVER_BUILD;
		tw_dev->tw_compat_info.driver_srl_low = TW_BASE_FW_SRL;
		tw_dev->tw_compat_info.driver_branch_low = TW_BASE_FW_BRANCH;
		tw_dev->tw_compat_info.driver_build_low = TW_BASE_FW_BUILD;
		tw_dev->tw_compat_info.fw_on_ctlr_srl = fw_on_ctlr_srl;
		tw_dev->tw_compat_info.fw_on_ctlr_branch = fw_on_ctlr_branch;
		tw_dev->tw_compat_info.fw_on_ctlr_build = fw_on_ctlr_build;

		/* If we got here, controller is in a good state */
		retval = 0;
		goto out;
	}
out:
	return retval;
} /* End twl_reset_sequence() */

/* This function will reset a device extension */
static int twl_reset_device_extension(TW_Device_Extension *tw_dev, int ioctl_reset)
{
	int i = 0, retval = 1;
	unsigned long flags = 0;

	/* Block SCSI requests while we are resetting */
	if (ioctl_reset)
		scsi_block_requests(tw_dev->host);

	set_bit(TW_IN_RESET, &tw_dev->flags);
	TWL_MASK_INTERRUPTS(tw_dev);
	TWL_CLEAR_DB_INTERRUPT(tw_dev);

	spin_lock_irqsave(tw_dev->host->host_lock, flags);

	/* Abort all requests that are in progress */
	for (i = 0; i < TW_Q_LENGTH; i++) {
		if ((tw_dev->state[i] != TW_S_FINISHED) &&
		    (tw_dev->state[i] != TW_S_INITIAL) &&
		    (tw_dev->state[i] != TW_S_COMPLETED)) {
			struct scsi_cmnd *cmd = tw_dev->srb[i];

			if (cmd) {
				cmd->result = (DID_RESET << 16);
				scsi_dma_unmap(cmd);
				scsi_done(cmd);
			}
		}
	}

	/* Reset queues and counts */
	for (i = 0; i < TW_Q_LENGTH; i++) {
		tw_dev->free_queue[i] = i;
		tw_dev->state[i] = TW_S_INITIAL;
	}
	tw_dev->free_head = TW_Q_START;
	tw_dev->free_tail = TW_Q_START;
	tw_dev->posted_request_count = 0;

	spin_unlock_irqrestore(tw_dev->host->host_lock, flags);

	if (twl_reset_sequence(tw_dev, 1))
		goto out;

	TWL_UNMASK_INTERRUPTS(tw_dev);

	clear_bit(TW_IN_RESET, &tw_dev->flags);
	tw_dev->chrdev_request_id = TW_IOCTL_CHRDEV_FREE;

	retval = 0;
out:
	if (ioctl_reset)
		scsi_unblock_requests(tw_dev->host);
	return retval;
} /* End twl_reset_device_extension() */

/* This funciton returns unit geometry in cylinders/heads/sectors */
static int twl_scsi_biosparam(struct scsi_device *sdev, struct block_device *bdev, sector_t capacity, int geom[])
{
	int heads, sectors;

	if (capacity >= 0x200000) {
		heads = 255;
		sectors = 63;
	} else {
		heads = 64;
		sectors = 32;
	}

	geom[0] = heads;
	geom[1] = sectors;
	geom[2] = sector_div(capacity, heads * sectors); /* cylinders */

	return 0;
} /* End twl_scsi_biosparam() */

/* This is the new scsi eh reset function */
static int twl_scsi_eh_reset(struct scsi_cmnd *SCpnt)
{
	TW_Device_Extension *tw_dev = NULL;
	int retval = FAILED;

	tw_dev = (TW_Device_Extension *)SCpnt->device->host->hostdata;

	tw_dev->num_resets++;

	sdev_printk(KERN_WARNING, SCpnt->device,
		"WARNING: (0x%02X:0x%04X): Command (0x%x) timed out, resetting card.\n",
		TW_DRIVER, 0x2c, SCpnt->cmnd[0]);

	/* Make sure we are not issuing an ioctl or resetting from ioctl */
	mutex_lock(&tw_dev->ioctl_lock);

	/* Now reset the card and some of the device extension data */
	if (twl_reset_device_extension(tw_dev, 0)) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x15, "Controller reset failed during scsi host reset");
		goto out;
	}

	retval = SUCCESS;
out:
	mutex_unlock(&tw_dev->ioctl_lock);
	return retval;
} /* End twl_scsi_eh_reset() */

/* This is the main scsi queue function to handle scsi opcodes */
static int twl_scsi_queue_lck(struct scsi_cmnd *SCpnt)
{
	void (*done)(struct scsi_cmnd *) = scsi_done;
	int request_id, retval;
	TW_Device_Extension *tw_dev = (TW_Device_Extension *)SCpnt->device->host->hostdata;

	/* If we are resetting due to timed out ioctl, report as busy */
	if (test_bit(TW_IN_RESET, &tw_dev->flags)) {
		retval = SCSI_MLQUEUE_HOST_BUSY;
		goto out;
	}

	/* Get a free request id */
	twl_get_request_id(tw_dev, &request_id);

	/* Save the scsi command for use by the ISR */
	tw_dev->srb[request_id] = SCpnt;

	retval = twl_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL);
	if (retval) {
		tw_dev->state[request_id] = TW_S_COMPLETED;
		twl_free_request_id(tw_dev, request_id);
		SCpnt->result = (DID_ERROR << 16);
		done(SCpnt);
		retval = 0;
	}
out:
	return retval;
} /* End twl_scsi_queue() */

static DEF_SCSI_QCMD(twl_scsi_queue)

/* This function tells the controller to shut down */
static void __twl_shutdown(TW_Device_Extension *tw_dev)
{
	/* Disable interrupts */
	TWL_MASK_INTERRUPTS(tw_dev);

	/* Free up the IRQ */
	free_irq(tw_dev->tw_pci_dev->irq, tw_dev);

	printk(KERN_WARNING "3w-sas: Shutting down host %d.\n", tw_dev->host->host_no);

	/* Tell the card we are shutting down */
	if (twl_initconnection(tw_dev, 1, 0, 0, 0, 0, 0, NULL, NULL, NULL, NULL, NULL)) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x16, "Connection shutdown failed");
	} else {
		printk(KERN_WARNING "3w-sas: Shutdown complete.\n");
	}

	/* Clear doorbell interrupt just before exit */
	TWL_CLEAR_DB_INTERRUPT(tw_dev);
} /* End __twl_shutdown() */

/* Wrapper for __twl_shutdown */
static void twl_shutdown(struct pci_dev *pdev)
{
	struct Scsi_Host *host = pci_get_drvdata(pdev);
	TW_Device_Extension *tw_dev;

	if (!host)
		return;

	tw_dev = (TW_Device_Extension *)host->hostdata;

	if (tw_dev->online)
		__twl_shutdown(tw_dev);
} /* End twl_shutdown() */

/* This function configures unit settings when a unit is coming on-line */
static int twl_slave_configure(struct scsi_device *sdev)
{
	/* Force 60 second timeout */
	blk_queue_rq_timeout(sdev->request_queue, 60 * HZ);

	return 0;
} /* End twl_slave_configure() */

static const struct scsi_host_template driver_template = {
	.module			= THIS_MODULE,
	.name			= "3w-sas",
	.queuecommand		= twl_scsi_queue,
	.eh_host_reset_handler	= twl_scsi_eh_reset,
	.bios_param		= twl_scsi_biosparam,
	.change_queue_depth	= scsi_change_queue_depth,
	.can_queue		= TW_Q_LENGTH-2,
	.slave_configure	= twl_slave_configure,
	.this_id		= -1,
	.sg_tablesize		= TW_LIBERATOR_MAX_SGL_LENGTH,
	.max_sectors		= TW_MAX_SECTORS,
	.cmd_per_lun		= TW_MAX_CMDS_PER_LUN,
	.shost_groups		= twl_host_groups,
	.emulated		= 1,
	.no_write_same		= 1,
};

/* This function will probe and initialize a card */
static int twl_probe(struct pci_dev *pdev, const struct pci_device_id *dev_id)
{
	struct Scsi_Host *host = NULL;
	TW_Device_Extension *tw_dev;
	int retval = -ENODEV;
	int *ptr_phycount, phycount=0;

	retval = pci_enable_device(pdev);
	if (retval) {
		TW_PRINTK(host, TW_DRIVER, 0x17, "Failed to enable pci device");
		goto out_disable_device;
	}

	pci_set_master(pdev);
	pci_try_set_mwi(pdev);

	retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
	if (retval) {
		TW_PRINTK(host, TW_DRIVER, 0x18, "Failed to set dma mask");
		retval = -ENODEV;
		goto out_disable_device;
	}

	host = scsi_host_alloc(&driver_template, sizeof(TW_Device_Extension));
	if (!host) {
		TW_PRINTK(host, TW_DRIVER, 0x19, "Failed to allocate memory for device extension");
		retval = -ENOMEM;
		goto out_disable_device;
	}
	tw_dev = shost_priv(host);

	/* Save values to device extension */
	tw_dev->host = host;
	tw_dev->tw_pci_dev = pdev;

	if (twl_initialize_device_extension(tw_dev)) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1a, "Failed to initialize device extension");
		retval = -ENOMEM;
		goto out_free_device_extension;
	}

	/* Request IO regions */
	retval = pci_request_regions(pdev, "3w-sas");
	if (retval) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1b, "Failed to get mem region");
		goto out_free_device_extension;
	}

	/* Save base address, use region 1 */
	tw_dev->base_addr = pci_iomap(pdev, 1, 0);
	if (!tw_dev->base_addr) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1c, "Failed to ioremap");
		retval = -ENOMEM;
		goto out_release_mem_region;
	}

	/* Disable interrupts on the card */
	TWL_MASK_INTERRUPTS(tw_dev);

	/* Initialize the card */
	if (twl_reset_sequence(tw_dev, 0)) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1d, "Controller reset failed during probe");
		retval = -ENOMEM;
		goto out_iounmap;
	}

	/* Set host specific parameters */
	host->max_id = TW_MAX_UNITS;
	host->max_cmd_len = TW_MAX_CDB_LEN;
	host->max_lun = TW_MAX_LUNS;
	host->max_channel = 0;

	/* Register the card with the kernel SCSI layer */
	retval = scsi_add_host(host, &pdev->dev);
	if (retval) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1e, "scsi add host failed");
		goto out_iounmap;
	}

	pci_set_drvdata(pdev, host);

	printk(KERN_WARNING "3w-sas: scsi%d: Found an LSI 3ware %s Controller at 0x%llx, IRQ: %d.\n",
	       host->host_no,
	       (char *)twl_get_param(tw_dev, 1, TW_VERSION_TABLE,
				     TW_PARAM_MODEL, TW_PARAM_MODEL_LENGTH),
	       (u64)pci_resource_start(pdev, 1), pdev->irq);

	ptr_phycount = twl_get_param(tw_dev, 2, TW_PARAM_PHY_SUMMARY_TABLE,
				     TW_PARAM_PHYCOUNT, TW_PARAM_PHYCOUNT_LENGTH);
	if (ptr_phycount)
		phycount = le32_to_cpu(*(int *)ptr_phycount);

	printk(KERN_WARNING "3w-sas: scsi%d: Firmware %s, BIOS %s, Phys: %d.\n",
	       host->host_no,
	       (char *)twl_get_param(tw_dev, 1, TW_VERSION_TABLE,
				     TW_PARAM_FWVER, TW_PARAM_FWVER_LENGTH),
	       (char *)twl_get_param(tw_dev, 2, TW_VERSION_TABLE,
				     TW_PARAM_BIOSVER, TW_PARAM_BIOSVER_LENGTH),
	       phycount);

	/* Try to enable MSI */
	if (use_msi && !pci_enable_msi(pdev))
		set_bit(TW_USING_MSI, &tw_dev->flags);

	/* Now setup the interrupt handler */
	retval = request_irq(pdev->irq, twl_interrupt, IRQF_SHARED, "3w-sas", tw_dev);
	if (retval) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1f, "Error requesting IRQ");
		goto out_remove_host;
	}

	twl_device_extension_list[twl_device_extension_count] = tw_dev;
	twl_device_extension_count++;

	/* Re-enable interrupts on the card */
	TWL_UNMASK_INTERRUPTS(tw_dev);

	/* Finally, scan the host */
	scsi_scan_host(host);

	/* Add sysfs binary files */
	if (sysfs_create_bin_file(&host->shost_dev.kobj, &twl_sysfs_aen_read_attr))
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x20, "Failed to create sysfs binary file: 3ware_aen_read");
	if (sysfs_create_bin_file(&host->shost_dev.kobj, &twl_sysfs_compat_info_attr))
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x21, "Failed to create sysfs binary file: 3ware_compat_info");

	if (twl_major == -1) {
		if ((twl_major = register_chrdev (0, "twl", &twl_fops)) < 0)
			TW_PRINTK(host, TW_DRIVER, 0x22, "Failed to register character device");
	}
	tw_dev->online = 1;
	return 0;

out_remove_host:
	if (test_bit(TW_USING_MSI, &tw_dev->flags))
		pci_disable_msi(pdev);
	scsi_remove_host(host);
out_iounmap:
	iounmap(tw_dev->base_addr);
out_release_mem_region:
	pci_release_regions(pdev);
out_free_device_extension:
	twl_free_device_extension(tw_dev);
	scsi_host_put(host);
out_disable_device:
	pci_disable_device(pdev);

	return retval;
} /* End twl_probe() */

/* This function is called to remove a device */
static void twl_remove(struct pci_dev *pdev)
{
	struct Scsi_Host *host = pci_get_drvdata(pdev);
	TW_Device_Extension *tw_dev;

	if (!host)
		return;

	tw_dev = (TW_Device_Extension *)host->hostdata;

	if (!tw_dev->online)
		return;

	/* Remove sysfs binary files */
	sysfs_remove_bin_file(&host->shost_dev.kobj, &twl_sysfs_aen_read_attr);
	sysfs_remove_bin_file(&host->shost_dev.kobj, &twl_sysfs_compat_info_attr);

	scsi_remove_host(tw_dev->host);

	/* Unregister character device */
	if (twl_major >= 0) {
		unregister_chrdev(twl_major, "twl");
		twl_major = -1;
	}

	/* Shutdown the card */
	__twl_shutdown(tw_dev);

	/* Disable MSI if enabled */
	if (test_bit(TW_USING_MSI, &tw_dev->flags))
		pci_disable_msi(pdev);

	/* Free IO remapping */
	iounmap(tw_dev->base_addr);

	/* Free up the mem region */
	pci_release_regions(pdev);

	/* Free up device extension resources */
	twl_free_device_extension(tw_dev);

	scsi_host_put(tw_dev->host);
	pci_disable_device(pdev);
	twl_device_extension_count--;
} /* End twl_remove() */

/* This function is called on PCI suspend */
static int __maybe_unused twl_suspend(struct device *dev)
{
	struct Scsi_Host *host = dev_get_drvdata(dev);
	TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;

	printk(KERN_WARNING "3w-sas: Suspending host %d.\n", tw_dev->host->host_no);
	/* Disable interrupts */
	TWL_MASK_INTERRUPTS(tw_dev);

	free_irq(tw_dev->tw_pci_dev->irq, tw_dev);

	/* Tell the card we are shutting down */
	if (twl_initconnection(tw_dev, 1, 0, 0, 0, 0, 0, NULL, NULL, NULL, NULL, NULL)) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x23, "Connection shutdown failed during suspend");
	} else {
		printk(KERN_WARNING "3w-sas: Suspend complete.\n");
	}

	/* Clear doorbell interrupt */
	TWL_CLEAR_DB_INTERRUPT(tw_dev);

	return 0;
} /* End twl_suspend() */

/* This function is called on PCI resume */
static int __maybe_unused twl_resume(struct device *dev)
{
	int retval = 0;
	struct pci_dev *pdev = to_pci_dev(dev);
	struct Scsi_Host *host = pci_get_drvdata(pdev);
	TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;

	printk(KERN_WARNING "3w-sas: Resuming host %d.\n", tw_dev->host->host_no);
	pci_try_set_mwi(pdev);

	retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
	if (retval) {
		TW_PRINTK(host, TW_DRIVER, 0x25, "Failed to set dma mask during resume");
		retval = -ENODEV;
		goto out_disable_device;
	}

	/* Initialize the card */
	if (twl_reset_sequence(tw_dev, 0)) {
		retval = -ENODEV;
		goto out_disable_device;
	}

	/* Now setup the interrupt handler */
	retval = request_irq(pdev->irq, twl_interrupt, IRQF_SHARED, "3w-sas", tw_dev);
	if (retval) {
		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x26, "Error requesting IRQ during resume");
		retval = -ENODEV;
		goto out_disable_device;
	}

	/* Now enable MSI if enabled */
	if (test_bit(TW_USING_MSI, &tw_dev->flags))
		pci_enable_msi(pdev);

	/* Re-enable interrupts on the card */
	TWL_UNMASK_INTERRUPTS(tw_dev);

	printk(KERN_WARNING "3w-sas: Resume complete.\n");
	return 0;

out_disable_device:
	scsi_remove_host(host);

	return retval;
} /* End twl_resume() */

/* PCI Devices supported by this driver */
static struct pci_device_id twl_pci_tbl[] = {
	{ PCI_VDEVICE(3WARE, PCI_DEVICE_ID_3WARE_9750) },
	{ }
};
MODULE_DEVICE_TABLE(pci, twl_pci_tbl);

static SIMPLE_DEV_PM_OPS(twl_pm_ops, twl_suspend, twl_resume);

/* pci_driver initializer */
static struct pci_driver twl_driver = {
	.name		= "3w-sas",
	.id_table	= twl_pci_tbl,
	.probe		= twl_probe,
	.remove		= twl_remove,
	.driver.pm	= &twl_pm_ops,
	.shutdown	= twl_shutdown
};

/* This function is called on driver initialization */
static int __init twl_init(void)
{
	printk(KERN_INFO "LSI 3ware SAS/SATA-RAID Controller device driver for Linux v%s.\n", TW_DRIVER_VERSION);

	return pci_register_driver(&twl_driver);
} /* End twl_init() */

/* This function is called on driver exit */
static void __exit twl_exit(void)
{
	pci_unregister_driver(&twl_driver);
} /* End twl_exit() */

module_init(twl_init);
module_exit(twl_exit);