/*
 * Adaptec AIC79xx device driver for Linux.
 *
 * $Id: //depot/aic7xxx/linux/drivers/scsi/aic7xxx/aic79xx_osm.c#171 $
 *
 * --------------------------------------------------------------------------
 * Copyright (c) 1994-2000 Justin T. Gibbs.
 * Copyright (c) 1997-1999 Doug Ledford
 * Copyright (c) 2000-2003 Adaptec Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * 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 OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include "aic79xx_osm.h"
#include "aic79xx_inline.h"
#include <scsi/scsicam.h>

static struct scsi_transport_template *ahd_linux_transport_template = NULL;

#include <linux/init.h>		/* __setup */
#include <linux/mm.h>		/* For fetching system memory size */
#include <linux/blkdev.h>		/* For block_size() */
#include <linux/delay.h>	/* For ssleep/msleep */
#include <linux/device.h>
#include <linux/slab.h>

/*
 * Bucket size for counting good commands in between bad ones.
 */
#define AHD_LINUX_ERR_THRESH	1000

/*
 * Set this to the delay in seconds after SCSI bus reset.
 * Note, we honor this only for the initial bus reset.
 * The scsi error recovery code performs its own bus settle
 * delay handling for error recovery actions.
 */
#ifdef CONFIG_AIC79XX_RESET_DELAY_MS
#define AIC79XX_RESET_DELAY CONFIG_AIC79XX_RESET_DELAY_MS
#else
#define AIC79XX_RESET_DELAY 5000
#endif

/*
 * To change the default number of tagged transactions allowed per-device,
 * add a line to the lilo.conf file like:
 * append="aic79xx=verbose,tag_info:{{32,32,32,32},{32,32,32,32}}"
 * which will result in the first four devices on the first two
 * controllers being set to a tagged queue depth of 32.
 *
 * The tag_commands is an array of 16 to allow for wide and twin adapters.
 * Twin adapters will use indexes 0-7 for channel 0, and indexes 8-15
 * for channel 1.
 */
typedef struct {
	uint16_t tag_commands[16];	/* Allow for wide/twin adapters. */
} adapter_tag_info_t;

/*
 * Modify this as you see fit for your system.
 *
 * 0			tagged queuing disabled
 * 1 <= n <= 253	n == max tags ever dispatched.
 *
 * The driver will throttle the number of commands dispatched to a
 * device if it returns queue full.  For devices with a fixed maximum
 * queue depth, the driver will eventually determine this depth and
 * lock it in (a console message is printed to indicate that a lock
 * has occurred).  On some devices, queue full is returned for a temporary
 * resource shortage.  These devices will return queue full at varying
 * depths.  The driver will throttle back when the queue fulls occur and
 * attempt to slowly increase the depth over time as the device recovers
 * from the resource shortage.
 *
 * In this example, the first line will disable tagged queueing for all
 * the devices on the first probed aic79xx adapter.
 *
 * The second line enables tagged queueing with 4 commands/LUN for IDs
 * (0, 2-11, 13-15), disables tagged queueing for ID 12, and tells the
 * driver to attempt to use up to 64 tags for ID 1.
 *
 * The third line is the same as the first line.
 *
 * The fourth line disables tagged queueing for devices 0 and 3.  It
 * enables tagged queueing for the other IDs, with 16 commands/LUN
 * for IDs 1 and 4, 127 commands/LUN for ID 8, and 4 commands/LUN for
 * IDs 2, 5-7, and 9-15.
 */

/*
 * NOTE: The below structure is for reference only, the actual structure
 *       to modify in order to change things is just below this comment block.
adapter_tag_info_t aic79xx_tag_info[] =
{
	{{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
	{{4, 64, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0, 4, 4, 4}},
	{{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
	{{0, 16, 4, 0, 16, 4, 4, 4, 127, 4, 4, 4, 4, 4, 4, 4}}
};
*/

#ifdef CONFIG_AIC79XX_CMDS_PER_DEVICE
#define AIC79XX_CMDS_PER_DEVICE CONFIG_AIC79XX_CMDS_PER_DEVICE
#else
#define AIC79XX_CMDS_PER_DEVICE AHD_MAX_QUEUE
#endif

#define AIC79XX_CONFIGED_TAG_COMMANDS {					\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE,		\
	AIC79XX_CMDS_PER_DEVICE, AIC79XX_CMDS_PER_DEVICE		\
}

/*
 * By default, use the number of commands specified by
 * the users kernel configuration.
 */
static adapter_tag_info_t aic79xx_tag_info[] =
{
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS},
	{AIC79XX_CONFIGED_TAG_COMMANDS}
};

/*
 * The I/O cell on the chip is very configurable in respect to its analog
 * characteristics.  Set the defaults here; they can be overriden with
 * the proper insmod parameters.
 */
struct ahd_linux_iocell_opts
{
	uint8_t	precomp;
	uint8_t	slewrate;
	uint8_t amplitude;
};
#define AIC79XX_DEFAULT_PRECOMP		0xFF
#define AIC79XX_DEFAULT_SLEWRATE	0xFF
#define AIC79XX_DEFAULT_AMPLITUDE	0xFF
#define AIC79XX_DEFAULT_IOOPTS			\
{						\
	AIC79XX_DEFAULT_PRECOMP,		\
	AIC79XX_DEFAULT_SLEWRATE,		\
	AIC79XX_DEFAULT_AMPLITUDE		\
}
#define AIC79XX_PRECOMP_INDEX	0
#define AIC79XX_SLEWRATE_INDEX	1
#define AIC79XX_AMPLITUDE_INDEX	2
static const struct ahd_linux_iocell_opts aic79xx_iocell_info[] =
{
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS,
	AIC79XX_DEFAULT_IOOPTS
};

/*
 * There should be a specific return value for this in scsi.h, but
 * it seems that most drivers ignore it.
 */
#define DID_UNDERFLOW   DID_ERROR

void
ahd_print_path(struct ahd_softc *ahd, struct scb *scb)
{
	printk("(scsi%d:%c:%d:%d): ",
	       ahd->platform_data->host->host_no,
	       scb != NULL ? SCB_GET_CHANNEL(ahd, scb) : 'X',
	       scb != NULL ? SCB_GET_TARGET(ahd, scb) : -1,
	       scb != NULL ? SCB_GET_LUN(scb) : -1);
}

/*
 * XXX - these options apply unilaterally to _all_ adapters
 *       cards in the system.  This should be fixed.  Exceptions to this
 *       rule are noted in the comments.
 */

/*
 * Skip the scsi bus reset.  Non 0 make us skip the reset at startup.  This
 * has no effect on any later resets that might occur due to things like
 * SCSI bus timeouts.
 */
static uint32_t aic79xx_no_reset;

/*
 * Should we force EXTENDED translation on a controller.
 *     0 == Use whatever is in the SEEPROM or default to off
 *     1 == Use whatever is in the SEEPROM or default to on
 */
static uint32_t aic79xx_extended;

/*
 * PCI bus parity checking of the Adaptec controllers.  This is somewhat
 * dubious at best.  To my knowledge, this option has never actually
 * solved a PCI parity problem, but on certain machines with broken PCI
 * chipset configurations, it can generate tons of false error messages.
 * It's included in the driver for completeness.
 *   0	   = Shut off PCI parity check
 *   non-0 = Enable PCI parity check
 *
 * NOTE: you can't actually pass -1 on the lilo prompt.  So, to set this
 * variable to -1 you would actually want to simply pass the variable
 * name without a number.  That will invert the 0 which will result in
 * -1.
 */
static uint32_t aic79xx_pci_parity = ~0;

/*
 * There are lots of broken chipsets in the world.  Some of them will
 * violate the PCI spec when we issue byte sized memory writes to our
 * controller.  I/O mapped register access, if allowed by the given
 * platform, will work in almost all cases.
 */
uint32_t aic79xx_allow_memio = ~0;

/*
 * So that we can set how long each device is given as a selection timeout.
 * The table of values goes like this:
 *   0 - 256ms
 *   1 - 128ms
 *   2 - 64ms
 *   3 - 32ms
 * We default to 256ms because some older devices need a longer time
 * to respond to initial selection.
 */
static uint32_t aic79xx_seltime;

/*
 * Certain devices do not perform any aging on commands.  Should the
 * device be saturated by commands in one portion of the disk, it is
 * possible for transactions on far away sectors to never be serviced.
 * To handle these devices, we can periodically send an ordered tag to
 * force all outstanding transactions to be serviced prior to a new
 * transaction.
 */
static uint32_t aic79xx_periodic_otag;

/* Some storage boxes are using an LSI chip which has a bug making it
 * impossible to use aic79xx Rev B chip in 320 speeds.  The following
 * storage boxes have been reported to be buggy:
 * EonStor 3U 16-Bay: U16U-G3A3
 * EonStor 2U 12-Bay: U12U-G3A3
 * SentinelRAID: 2500F R5 / R6
 * SentinelRAID: 2500F R1
 * SentinelRAID: 2500F/1500F
 * SentinelRAID: 150F
 * 
 * To get around this LSI bug, you can set your board to 160 mode
 * or you can enable the SLOWCRC bit.
 */
uint32_t aic79xx_slowcrc;

/*
 * Module information and settable options.
 */
static char *aic79xx = NULL;

MODULE_AUTHOR("Maintainer: Hannes Reinecke <hare@suse.de>");
MODULE_DESCRIPTION("Adaptec AIC790X U320 SCSI Host Bus Adapter driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_VERSION(AIC79XX_DRIVER_VERSION);
module_param(aic79xx, charp, 0444);
MODULE_PARM_DESC(aic79xx,
"period-delimited options string:\n"
"	verbose			Enable verbose/diagnostic logging\n"
"	allow_memio		Allow device registers to be memory mapped\n"
"	debug			Bitmask of debug values to enable\n"
"	no_reset		Suppress initial bus resets\n"
"	extended		Enable extended geometry on all controllers\n"
"	periodic_otag		Send an ordered tagged transaction\n"
"				periodically to prevent tag starvation.\n"
"				This may be required by some older disk\n"
"				or drives/RAID arrays.\n"
"	tag_info:<tag_str>	Set per-target tag depth\n"
"	global_tag_depth:<int>	Global tag depth for all targets on all buses\n"
"	slewrate:<slewrate_list>Set the signal slew rate (0-15).\n"
"	precomp:<pcomp_list>	Set the signal precompensation (0-7).\n"
"	amplitude:<int>		Set the signal amplitude (0-7).\n"
"	seltime:<int>		Selection Timeout:\n"
"				(0/256ms,1/128ms,2/64ms,3/32ms)\n"
"	slowcrc			Turn on the SLOWCRC bit (Rev B only)\n"		 
"\n"
"	Sample modprobe configuration file:\n"
"	#	Enable verbose logging\n"
"	#	Set tag depth on Controller 2/Target 2 to 10 tags\n"
"	#	Shorten the selection timeout to 128ms\n"
"\n"
"	options aic79xx 'aic79xx=verbose.tag_info:{{}.{}.{..10}}.seltime:1'\n"
);

static void ahd_linux_handle_scsi_status(struct ahd_softc *,
					 struct scsi_device *,
					 struct scb *);
static void ahd_linux_queue_cmd_complete(struct ahd_softc *ahd,
					 struct scsi_cmnd *cmd);
static int ahd_linux_queue_abort_cmd(struct scsi_cmnd *cmd);
static void ahd_linux_initialize_scsi_bus(struct ahd_softc *ahd);
static u_int ahd_linux_user_tagdepth(struct ahd_softc *ahd,
				     struct ahd_devinfo *devinfo);
static void ahd_linux_device_queue_depth(struct scsi_device *);
static int ahd_linux_run_command(struct ahd_softc*,
				 struct ahd_linux_device *,
				 struct scsi_cmnd *);
static void ahd_linux_setup_tag_info_global(char *p);
static int  aic79xx_setup(char *c);
static void ahd_freeze_simq(struct ahd_softc *ahd);
static void ahd_release_simq(struct ahd_softc *ahd);

static int ahd_linux_unit;


/************************** OS Utility Wrappers *******************************/
void ahd_delay(long);
void
ahd_delay(long usec)
{
	/*
	 * udelay on Linux can have problems for
	 * multi-millisecond waits.  Wait at most
	 * 1024us per call.
	 */
	while (usec > 0) {
		udelay(usec % 1024);
		usec -= 1024;
	}
}


/***************************** Low Level I/O **********************************/
uint8_t ahd_inb(struct ahd_softc * ahd, long port);
void ahd_outb(struct ahd_softc * ahd, long port, uint8_t val);
void ahd_outw_atomic(struct ahd_softc * ahd,
				     long port, uint16_t val);
void ahd_outsb(struct ahd_softc * ahd, long port,
			       uint8_t *, int count);
void ahd_insb(struct ahd_softc * ahd, long port,
			       uint8_t *, int count);

uint8_t
ahd_inb(struct ahd_softc * ahd, long port)
{
	uint8_t x;

	if (ahd->tags[0] == BUS_SPACE_MEMIO) {
		x = readb(ahd->bshs[0].maddr + port);
	} else {
		x = inb(ahd->bshs[(port) >> 8].ioport + ((port) & 0xFF));
	}
	mb();
	return (x);
}

#if 0 /* unused */
static uint16_t
ahd_inw_atomic(struct ahd_softc * ahd, long port)
{
	uint8_t x;

	if (ahd->tags[0] == BUS_SPACE_MEMIO) {
		x = readw(ahd->bshs[0].maddr + port);
	} else {
		x = inw(ahd->bshs[(port) >> 8].ioport + ((port) & 0xFF));
	}
	mb();
	return (x);
}
#endif

void
ahd_outb(struct ahd_softc * ahd, long port, uint8_t val)
{
	if (ahd->tags[0] == BUS_SPACE_MEMIO) {
		writeb(val, ahd->bshs[0].maddr + port);
	} else {
		outb(val, ahd->bshs[(port) >> 8].ioport + (port & 0xFF));
	}
	mb();
}

void
ahd_outw_atomic(struct ahd_softc * ahd, long port, uint16_t val)
{
	if (ahd->tags[0] == BUS_SPACE_MEMIO) {
		writew(val, ahd->bshs[0].maddr + port);
	} else {
		outw(val, ahd->bshs[(port) >> 8].ioport + (port & 0xFF));
	}
	mb();
}

void
ahd_outsb(struct ahd_softc * ahd, long port, uint8_t *array, int count)
{
	int i;

	/*
	 * There is probably a more efficient way to do this on Linux
	 * but we don't use this for anything speed critical and this
	 * should work.
	 */
	for (i = 0; i < count; i++)
		ahd_outb(ahd, port, *array++);
}

void
ahd_insb(struct ahd_softc * ahd, long port, uint8_t *array, int count)
{
	int i;

	/*
	 * There is probably a more efficient way to do this on Linux
	 * but we don't use this for anything speed critical and this
	 * should work.
	 */
	for (i = 0; i < count; i++)
		*array++ = ahd_inb(ahd, port);
}

/******************************* PCI Routines *********************************/
uint32_t
ahd_pci_read_config(ahd_dev_softc_t pci, int reg, int width)
{
	switch (width) {
	case 1:
	{
		uint8_t retval;

		pci_read_config_byte(pci, reg, &retval);
		return (retval);
	}
	case 2:
	{
		uint16_t retval;
		pci_read_config_word(pci, reg, &retval);
		return (retval);
	}
	case 4:
	{
		uint32_t retval;
		pci_read_config_dword(pci, reg, &retval);
		return (retval);
	}
	default:
		panic("ahd_pci_read_config: Read size too big");
		/* NOTREACHED */
		return (0);
	}
}

void
ahd_pci_write_config(ahd_dev_softc_t pci, int reg, uint32_t value, int width)
{
	switch (width) {
	case 1:
		pci_write_config_byte(pci, reg, value);
		break;
	case 2:
		pci_write_config_word(pci, reg, value);
		break;
	case 4:
		pci_write_config_dword(pci, reg, value);
		break;
	default:
		panic("ahd_pci_write_config: Write size too big");
		/* NOTREACHED */
	}
}

/****************************** Inlines ***************************************/
static void ahd_linux_unmap_scb(struct ahd_softc*, struct scb*);

static void
ahd_linux_unmap_scb(struct ahd_softc *ahd, struct scb *scb)
{
	struct scsi_cmnd *cmd;

	cmd = scb->io_ctx;
	ahd_sync_sglist(ahd, scb, BUS_DMASYNC_POSTWRITE);
	scsi_dma_unmap(cmd);
}

/******************************** Macros **************************************/
#define BUILD_SCSIID(ahd, cmd)						\
	(((scmd_id(cmd) << TID_SHIFT) & TID) | (ahd)->our_id)

/*
 * Return a string describing the driver.
 */
static const char *
ahd_linux_info(struct Scsi_Host *host)
{
	static char buffer[512];
	char	ahd_info[256];
	char   *bp;
	struct ahd_softc *ahd;

	bp = &buffer[0];
	ahd = *(struct ahd_softc **)host->hostdata;
	memset(bp, 0, sizeof(buffer));
	strcpy(bp, "Adaptec AIC79XX PCI-X SCSI HBA DRIVER, Rev " AIC79XX_DRIVER_VERSION "\n"
			"        <");
	strcat(bp, ahd->description);
	strcat(bp, ">\n"
			"        ");
	ahd_controller_info(ahd, ahd_info);
	strcat(bp, ahd_info);

	return (bp);
}

/*
 * Queue an SCB to the controller.
 */
static int
ahd_linux_queue_lck(struct scsi_cmnd * cmd, void (*scsi_done) (struct scsi_cmnd *))
{
	struct	 ahd_softc *ahd;
	struct	 ahd_linux_device *dev = scsi_transport_device_data(cmd->device);
	int rtn = SCSI_MLQUEUE_HOST_BUSY;

	ahd = *(struct ahd_softc **)cmd->device->host->hostdata;

	cmd->scsi_done = scsi_done;
	cmd->result = CAM_REQ_INPROG << 16;
	rtn = ahd_linux_run_command(ahd, dev, cmd);

	return rtn;
}

static DEF_SCSI_QCMD(ahd_linux_queue)

static struct scsi_target **
ahd_linux_target_in_softc(struct scsi_target *starget)
{
	struct	ahd_softc *ahd =
		*((struct ahd_softc **)dev_to_shost(&starget->dev)->hostdata);
	unsigned int target_offset;

	target_offset = starget->id;
	if (starget->channel != 0)
		target_offset += 8;

	return &ahd->platform_data->starget[target_offset];
}

static int
ahd_linux_target_alloc(struct scsi_target *starget)
{
	struct	ahd_softc *ahd =
		*((struct ahd_softc **)dev_to_shost(&starget->dev)->hostdata);
	struct seeprom_config *sc = ahd->seep_config;
	unsigned long flags;
	struct scsi_target **ahd_targp = ahd_linux_target_in_softc(starget);
	struct ahd_devinfo devinfo;
	struct ahd_initiator_tinfo *tinfo;
	struct ahd_tmode_tstate *tstate;
	char channel = starget->channel + 'A';

	ahd_lock(ahd, &flags);

	BUG_ON(*ahd_targp != NULL);

	*ahd_targp = starget;

	if (sc) {
		int flags = sc->device_flags[starget->id];

		tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
					    starget->id, &tstate);

		if ((flags  & CFPACKETIZED) == 0) {
			/* don't negotiate packetized (IU) transfers */
			spi_max_iu(starget) = 0;
		} else {
			if ((ahd->features & AHD_RTI) == 0)
				spi_rti(starget) = 0;
		}

		if ((flags & CFQAS) == 0)
			spi_max_qas(starget) = 0;

		/* Transinfo values have been set to BIOS settings */
		spi_max_width(starget) = (flags & CFWIDEB) ? 1 : 0;
		spi_min_period(starget) = tinfo->user.period;
		spi_max_offset(starget) = tinfo->user.offset;
	}

	tinfo = ahd_fetch_transinfo(ahd, channel, ahd->our_id,
				    starget->id, &tstate);
	ahd_compile_devinfo(&devinfo, ahd->our_id, starget->id,
			    CAM_LUN_WILDCARD, channel,
			    ROLE_INITIATOR);
	ahd_set_syncrate(ahd, &devinfo, 0, 0, 0,
			 AHD_TRANS_GOAL, /*paused*/FALSE);
	ahd_set_width(ahd, &devinfo, MSG_EXT_WDTR_BUS_8_BIT,
		      AHD_TRANS_GOAL, /*paused*/FALSE);
	ahd_unlock(ahd, &flags);

	return 0;
}

static void
ahd_linux_target_destroy(struct scsi_target *starget)
{
	struct scsi_target **ahd_targp = ahd_linux_target_in_softc(starget);

	*ahd_targp = NULL;
}

static int
ahd_linux_slave_alloc(struct scsi_device *sdev)
{
	struct	ahd_softc *ahd =
		*((struct ahd_softc **)sdev->host->hostdata);
	struct ahd_linux_device *dev;

	if (bootverbose)
		printk("%s: Slave Alloc %d\n", ahd_name(ahd), sdev->id);

	dev = scsi_transport_device_data(sdev);
	memset(dev, 0, sizeof(*dev));

	/*
	 * We start out life using untagged
	 * transactions of which we allow one.
	 */
	dev->openings = 1;

	/*
	 * Set maxtags to 0.  This will be changed if we
	 * later determine that we are dealing with
	 * a tagged queuing capable device.
	 */
	dev->maxtags = 0;
	
	return (0);
}

static int
ahd_linux_slave_configure(struct scsi_device *sdev)
{
	struct	ahd_softc *ahd;

	ahd = *((struct ahd_softc **)sdev->host->hostdata);
	if (bootverbose)
		sdev_printk(KERN_INFO, sdev, "Slave Configure\n");

	ahd_linux_device_queue_depth(sdev);

	/* Initial Domain Validation */
	if (!spi_initial_dv(sdev->sdev_target))
		spi_dv_device(sdev);

	return 0;
}

#if defined(__i386__)
/*
 * Return the disk geometry for the given SCSI device.
 */
static int
ahd_linux_biosparam(struct scsi_device *sdev, struct block_device *bdev,
		    sector_t capacity, int geom[])
{
	int	 heads;
	int	 sectors;
	int	 cylinders;
	int	 extended;
	struct	 ahd_softc *ahd;

	ahd = *((struct ahd_softc **)sdev->host->hostdata);

	if (scsi_partsize(bdev, capacity, geom))
		return 0;

	heads = 64;
	sectors = 32;
	cylinders = aic_sector_div(capacity, heads, sectors);

	if (aic79xx_extended != 0)
		extended = 1;
	else
		extended = (ahd->flags & AHD_EXTENDED_TRANS_A) != 0;
	if (extended && cylinders >= 1024) {
		heads = 255;
		sectors = 63;
		cylinders = aic_sector_div(capacity, heads, sectors);
	}
	geom[0] = heads;
	geom[1] = sectors;
	geom[2] = cylinders;
	return (0);
}
#endif

/*
 * Abort the current SCSI command(s).
 */
static int
ahd_linux_abort(struct scsi_cmnd *cmd)
{
	int error;
	
	error = ahd_linux_queue_abort_cmd(cmd);

	return error;
}

/*
 * Attempt to send a target reset message to the device that timed out.
 */
static int
ahd_linux_dev_reset(struct scsi_cmnd *cmd)
{
	struct ahd_softc *ahd;
	struct ahd_linux_device *dev;
	struct scb *reset_scb;
	u_int  cdb_byte;
	int    retval = SUCCESS;
	int    paused;
	int    wait;
	struct	ahd_initiator_tinfo *tinfo;
	struct	ahd_tmode_tstate *tstate;
	unsigned long flags;
	DECLARE_COMPLETION_ONSTACK(done);

	reset_scb = NULL;
	paused = FALSE;
	wait = FALSE;
	ahd = *(struct ahd_softc **)cmd->device->host->hostdata;

	scmd_printk(KERN_INFO, cmd,
		    "Attempting to queue a TARGET RESET message:");

	printk("CDB:");
	for (cdb_byte = 0; cdb_byte < cmd->cmd_len; cdb_byte++)
		printk(" 0x%x", cmd->cmnd[cdb_byte]);
	printk("\n");

	/*
	 * Determine if we currently own this command.
	 */
	dev = scsi_transport_device_data(cmd->device);

	if (dev == NULL) {
		/*
		 * No target device for this command exists,
		 * so we must not still own the command.
		 */
		scmd_printk(KERN_INFO, cmd, "Is not an active device\n");
		return SUCCESS;
	}

	/*
	 * Generate us a new SCB
	 */
	reset_scb = ahd_get_scb(ahd, AHD_NEVER_COL_IDX);
	if (!reset_scb) {
		scmd_printk(KERN_INFO, cmd, "No SCB available\n");
		return FAILED;
	}

	tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
				    cmd->device->id, &tstate);
	reset_scb->io_ctx = cmd;
	reset_scb->platform_data->dev = dev;
	reset_scb->sg_count = 0;
	ahd_set_residual(reset_scb, 0);
	ahd_set_sense_residual(reset_scb, 0);
	reset_scb->platform_data->xfer_len = 0;
	reset_scb->hscb->control = 0;
	reset_scb->hscb->scsiid = BUILD_SCSIID(ahd,cmd);
	reset_scb->hscb->lun = cmd->device->lun;
	reset_scb->hscb->cdb_len = 0;
	reset_scb->hscb->task_management = SIU_TASKMGMT_LUN_RESET;
	reset_scb->flags |= SCB_DEVICE_RESET|SCB_RECOVERY_SCB|SCB_ACTIVE;
	if ((tinfo->curr.ppr_options & MSG_EXT_PPR_IU_REQ) != 0) {
		reset_scb->flags |= SCB_PACKETIZED;
	} else {
		reset_scb->hscb->control |= MK_MESSAGE;
	}
	dev->openings--;
	dev->active++;
	dev->commands_issued++;

	ahd_lock(ahd, &flags);

	LIST_INSERT_HEAD(&ahd->pending_scbs, reset_scb, pending_links);
	ahd_queue_scb(ahd, reset_scb);

	ahd->platform_data->eh_done = &done;
	ahd_unlock(ahd, &flags);

	printk("%s: Device reset code sleeping\n", ahd_name(ahd));
	if (!wait_for_completion_timeout(&done, 5 * HZ)) {
		ahd_lock(ahd, &flags);
		ahd->platform_data->eh_done = NULL;
		ahd_unlock(ahd, &flags);
		printk("%s: Device reset timer expired (active %d)\n",
		       ahd_name(ahd), dev->active);
		retval = FAILED;
	}
	printk("%s: Device reset returning 0x%x\n", ahd_name(ahd), retval);

	return (retval);
}

/*
 * Reset the SCSI bus.
 */
static int
ahd_linux_bus_reset(struct scsi_cmnd *cmd)
{
	struct ahd_softc *ahd;
	int    found;
	unsigned long flags;

	ahd = *(struct ahd_softc **)cmd->device->host->hostdata;
#ifdef AHD_DEBUG
	if ((ahd_debug & AHD_SHOW_RECOVERY) != 0)
		printk("%s: Bus reset called for cmd %p\n",
		       ahd_name(ahd), cmd);
#endif
	ahd_lock(ahd, &flags);

	found = ahd_reset_channel(ahd, scmd_channel(cmd) + 'A',
				  /*initiate reset*/TRUE);
	ahd_unlock(ahd, &flags);

	if (bootverbose)
		printk("%s: SCSI bus reset delivered. "
		       "%d SCBs aborted.\n", ahd_name(ahd), found);

	return (SUCCESS);
}

struct scsi_host_template aic79xx_driver_template = {
	.module			= THIS_MODULE,
	.name			= "aic79xx",
	.proc_name		= "aic79xx",
	.show_info		= ahd_linux_show_info,
	.write_info	 	= ahd_proc_write_seeprom,
	.info			= ahd_linux_info,
	.queuecommand		= ahd_linux_queue,
	.eh_abort_handler	= ahd_linux_abort,
	.eh_device_reset_handler = ahd_linux_dev_reset,
	.eh_bus_reset_handler	= ahd_linux_bus_reset,
#if defined(__i386__)
	.bios_param		= ahd_linux_biosparam,
#endif
	.can_queue		= AHD_MAX_QUEUE,
	.this_id		= -1,
	.max_sectors		= 8192,
	.cmd_per_lun		= 2,
	.slave_alloc		= ahd_linux_slave_alloc,
	.slave_configure	= ahd_linux_slave_configure,
	.target_alloc		= ahd_linux_target_alloc,
	.target_destroy		= ahd_linux_target_destroy,
};

/******************************** Bus DMA *************************************/
int
ahd_dma_tag_create(struct ahd_softc *ahd, bus_dma_tag_t parent,
		   bus_size_t alignment, bus_size_t boundary,
		   dma_addr_t lowaddr, dma_addr_t highaddr,
		   bus_dma_filter_t *filter, void *filterarg,
		   bus_size_t maxsize, int nsegments,
		   bus_size_t maxsegsz, int flags, bus_dma_tag_t *ret_tag)
{
	bus_dma_tag_t dmat;

	dmat = kmalloc(sizeof(*dmat), GFP_ATOMIC);
	if (dmat == NULL)
		return (ENOMEM);

	/*
	 * Linux is very simplistic about DMA memory.  For now don't
	 * maintain all specification information.  Once Linux supplies
	 * better facilities for doing these operations, or the
	 * needs of this particular driver change, we might need to do
	 * more here.
	 */
	dmat->alignment = alignment;
	dmat->boundary = boundary;
	dmat->maxsize = maxsize;
	*ret_tag = dmat;
	return (0);
}

void
ahd_dma_tag_destroy(struct ahd_softc *ahd, bus_dma_tag_t dmat)
{
	kfree(dmat);
}

int
ahd_dmamem_alloc(struct ahd_softc *ahd, bus_dma_tag_t dmat, void** vaddr,
		 int flags, bus_dmamap_t *mapp)
{
	*vaddr = pci_alloc_consistent(ahd->dev_softc,
				      dmat->maxsize, mapp);
	if (*vaddr == NULL)
		return (ENOMEM);
	return(0);
}

void
ahd_dmamem_free(struct ahd_softc *ahd, bus_dma_tag_t dmat,
		void* vaddr, bus_dmamap_t map)
{
	pci_free_consistent(ahd->dev_softc, dmat->maxsize,
			    vaddr, map);
}

int
ahd_dmamap_load(struct ahd_softc *ahd, bus_dma_tag_t dmat, bus_dmamap_t map,
		void *buf, bus_size_t buflen, bus_dmamap_callback_t *cb,
		void *cb_arg, int flags)
{
	/*
	 * Assume for now that this will only be used during
	 * initialization and not for per-transaction buffer mapping.
	 */
	bus_dma_segment_t stack_sg;

	stack_sg.ds_addr = map;
	stack_sg.ds_len = dmat->maxsize;
	cb(cb_arg, &stack_sg, /*nseg*/1, /*error*/0);
	return (0);
}

void
ahd_dmamap_destroy(struct ahd_softc *ahd, bus_dma_tag_t dmat, bus_dmamap_t map)
{
}

int
ahd_dmamap_unload(struct ahd_softc *ahd, bus_dma_tag_t dmat, bus_dmamap_t map)
{
	/* Nothing to do */
	return (0);
}

/********************* Platform Dependent Functions ***************************/
static void
ahd_linux_setup_iocell_info(u_long index, int instance, int targ, int32_t value)
{

	if ((instance >= 0)
	 && (instance < ARRAY_SIZE(aic79xx_iocell_info))) {
		uint8_t *iocell_info;

		iocell_info = (uint8_t*)&aic79xx_iocell_info[instance];
		iocell_info[index] = value & 0xFFFF;
		if (bootverbose)
			printk("iocell[%d:%ld] = %d\n", instance, index, value);
	}
}

static void
ahd_linux_setup_tag_info_global(char *p)
{
	int tags, i, j;

	tags = simple_strtoul(p + 1, NULL, 0) & 0xff;
	printk("Setting Global Tags= %d\n", tags);

	for (i = 0; i < ARRAY_SIZE(aic79xx_tag_info); i++) {
		for (j = 0; j < AHD_NUM_TARGETS; j++) {
			aic79xx_tag_info[i].tag_commands[j] = tags;
		}
	}
}

static void
ahd_linux_setup_tag_info(u_long arg, int instance, int targ, int32_t value)
{

	if ((instance >= 0) && (targ >= 0)
	 && (instance < ARRAY_SIZE(aic79xx_tag_info))
	 && (targ < AHD_NUM_TARGETS)) {
		aic79xx_tag_info[instance].tag_commands[targ] = value & 0x1FF;
		if (bootverbose)
			printk("tag_info[%d:%d] = %d\n", instance, targ, value);
	}
}

static char *
ahd_parse_brace_option(char *opt_name, char *opt_arg, char *end, int depth,
		       void (*callback)(u_long, int, int, int32_t),
		       u_long callback_arg)
{
	char	*tok_end;
	char	*tok_end2;
	int      i;
	int      instance;
	int	 targ;
	int	 done;
	char	 tok_list[] = {'.', ',', '{', '}', '\0'};

	/* All options use a ':' name/arg separator */
	if (*opt_arg != ':')
		return (opt_arg);
	opt_arg++;
	instance = -1;
	targ = -1;
	done = FALSE;
	/*
	 * Restore separator that may be in
	 * the middle of our option argument.
	 */
	tok_end = strchr(opt_arg, '\0');
	if (tok_end < end)
		*tok_end = ',';
	while (!done) {
		switch (*opt_arg) {
		case '{':
			if (instance == -1) {
				instance = 0;
			} else {
				if (depth > 1) {
					if (targ == -1)
						targ = 0;
				} else {
					printk("Malformed Option %s\n",
					       opt_name);
					done = TRUE;
				}
			}
			opt_arg++;
			break;
		case '}':
			if (targ != -1)
				targ = -1;
			else if (instance != -1)
				instance = -1;
			opt_arg++;
			break;
		case ',':
		case '.':
			if (instance == -1)
				done = TRUE;
			else if (targ >= 0)
				targ++;
			else if (instance >= 0)
				instance++;
			opt_arg++;
			break;
		case '\0':
			done = TRUE;
			break;
		default:
			tok_end = end;
			for (i = 0; tok_list[i]; i++) {
				tok_end2 = strchr(opt_arg, tok_list[i]);
				if ((tok_end2) && (tok_end2 < tok_end))
					tok_end = tok_end2;
			}
			callback(callback_arg, instance, targ,
				 simple_strtol(opt_arg, NULL, 0));
			opt_arg = tok_end;
			break;
		}
	}
	return (opt_arg);
}

/*
 * Handle Linux boot parameters. This routine allows for assigning a value
 * to a parameter with a ':' between the parameter and the value.
 * ie. aic79xx=stpwlev:1,extended
 */
static int
aic79xx_setup(char *s)
{
	int	i, n;
	char   *p;
	char   *end;

	static const struct {
		const char *name;
		uint32_t *flag;
	} options[] = {
		{ "extended", &aic79xx_extended },
		{ "no_reset", &aic79xx_no_reset },
		{ "verbose", &aic79xx_verbose },
		{ "allow_memio", &aic79xx_allow_memio},
#ifdef AHD_DEBUG
		{ "debug", &ahd_debug },
#endif
		{ "periodic_otag", &aic79xx_periodic_otag },
		{ "pci_parity", &aic79xx_pci_parity },
		{ "seltime", &aic79xx_seltime },
		{ "tag_info", NULL },
		{ "global_tag_depth", NULL},
		{ "slewrate", NULL },
		{ "precomp", NULL },
		{ "amplitude", NULL },
		{ "slowcrc", &aic79xx_slowcrc },
	};

	end = strchr(s, '\0');

	/*
	 * XXX ia64 gcc isn't smart enough to know that ARRAY_SIZE
	 * will never be 0 in this case.
	 */
	n = 0;

	while ((p = strsep(&s, ",.")) != NULL) {
		if (*p == '\0')
			continue;
		for (i = 0; i < ARRAY_SIZE(options); i++) {

			n = strlen(options[i].name);
			if (strncmp(options[i].name, p, n) == 0)
				break;
		}
		if (i == ARRAY_SIZE(options))
			continue;

		if (strncmp(p, "global_tag_depth", n) == 0) {
			ahd_linux_setup_tag_info_global(p + n);
		} else if (strncmp(p, "tag_info", n) == 0) {
			s = ahd_parse_brace_option("tag_info", p + n, end,
			    2, ahd_linux_setup_tag_info, 0);
		} else if (strncmp(p, "slewrate", n) == 0) {
			s = ahd_parse_brace_option("slewrate",
			    p + n, end, 1, ahd_linux_setup_iocell_info,
			    AIC79XX_SLEWRATE_INDEX);
		} else if (strncmp(p, "precomp", n) == 0) {
			s = ahd_parse_brace_option("precomp",
			    p + n, end, 1, ahd_linux_setup_iocell_info,
			    AIC79XX_PRECOMP_INDEX);
		} else if (strncmp(p, "amplitude", n) == 0) {
			s = ahd_parse_brace_option("amplitude",
			    p + n, end, 1, ahd_linux_setup_iocell_info,
			    AIC79XX_AMPLITUDE_INDEX);
		} else if (p[n] == ':') {
			*(options[i].flag) = simple_strtoul(p + n + 1, NULL, 0);
		} else if (!strncmp(p, "verbose", n)) {
			*(options[i].flag) = 1;
		} else {
			*(options[i].flag) ^= 0xFFFFFFFF;
		}
	}
	return 1;
}

__setup("aic79xx=", aic79xx_setup);

uint32_t aic79xx_verbose;

int
ahd_linux_register_host(struct ahd_softc *ahd, struct scsi_host_template *template)
{
	char	buf[80];
	struct	Scsi_Host *host;
	char	*new_name;
	u_long	s;
	int	retval;

	template->name = ahd->description;
	host = scsi_host_alloc(template, sizeof(struct ahd_softc *));
	if (host == NULL)
		return (ENOMEM);

	*((struct ahd_softc **)host->hostdata) = ahd;
	ahd->platform_data->host = host;
	host->can_queue = AHD_MAX_QUEUE;
	host->cmd_per_lun = 2;
	host->sg_tablesize = AHD_NSEG;
	host->this_id = ahd->our_id;
	host->irq = ahd->platform_data->irq;
	host->max_id = (ahd->features & AHD_WIDE) ? 16 : 8;
	host->max_lun = AHD_NUM_LUNS;
	host->max_channel = 0;
	host->sg_tablesize = AHD_NSEG;
	ahd_lock(ahd, &s);
	ahd_set_unit(ahd, ahd_linux_unit++);
	ahd_unlock(ahd, &s);
	sprintf(buf, "scsi%d", host->host_no);
	new_name = kmalloc(strlen(buf) + 1, GFP_ATOMIC);
	if (new_name != NULL) {
		strcpy(new_name, buf);
		ahd_set_name(ahd, new_name);
	}
	host->unique_id = ahd->unit;
	ahd_linux_initialize_scsi_bus(ahd);
	ahd_intr_enable(ahd, TRUE);

	host->transportt = ahd_linux_transport_template;

	retval = scsi_add_host(host, &ahd->dev_softc->dev);
	if (retval) {
		printk(KERN_WARNING "aic79xx: scsi_add_host failed\n");
		scsi_host_put(host);
		return retval;
	}

	scsi_scan_host(host);
	return 0;
}

/*
 * Place the SCSI bus into a known state by either resetting it,
 * or forcing transfer negotiations on the next command to any
 * target.
 */
static void
ahd_linux_initialize_scsi_bus(struct ahd_softc *ahd)
{
	u_int target_id;
	u_int numtarg;
	unsigned long s;

	target_id = 0;
	numtarg = 0;

	if (aic79xx_no_reset != 0)
		ahd->flags &= ~AHD_RESET_BUS_A;

	if ((ahd->flags & AHD_RESET_BUS_A) != 0)
		ahd_reset_channel(ahd, 'A', /*initiate_reset*/TRUE);
	else
		numtarg = (ahd->features & AHD_WIDE) ? 16 : 8;

	ahd_lock(ahd, &s);

	/*
	 * Force negotiation to async for all targets that
	 * will not see an initial bus reset.
	 */
	for (; target_id < numtarg; target_id++) {
		struct ahd_devinfo devinfo;
		struct ahd_initiator_tinfo *tinfo;
		struct ahd_tmode_tstate *tstate;

		tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
					    target_id, &tstate);
		ahd_compile_devinfo(&devinfo, ahd->our_id, target_id,
				    CAM_LUN_WILDCARD, 'A', ROLE_INITIATOR);
		ahd_update_neg_request(ahd, &devinfo, tstate,
				       tinfo, AHD_NEG_ALWAYS);
	}
	ahd_unlock(ahd, &s);
	/* Give the bus some time to recover */
	if ((ahd->flags & AHD_RESET_BUS_A) != 0) {
		ahd_freeze_simq(ahd);
		msleep(AIC79XX_RESET_DELAY);
		ahd_release_simq(ahd);
	}
}

int
ahd_platform_alloc(struct ahd_softc *ahd, void *platform_arg)
{
	ahd->platform_data =
	    kzalloc(sizeof(struct ahd_platform_data), GFP_ATOMIC);
	if (ahd->platform_data == NULL)
		return (ENOMEM);
	ahd->platform_data->irq = AHD_LINUX_NOIRQ;
	ahd_lockinit(ahd);
	ahd->seltime = (aic79xx_seltime & 0x3) << 4;
	return (0);
}

void
ahd_platform_free(struct ahd_softc *ahd)
{
	struct scsi_target *starget;
	int i;

	if (ahd->platform_data != NULL) {
		/* destroy all of the device and target objects */
		for (i = 0; i < AHD_NUM_TARGETS; i++) {
			starget = ahd->platform_data->starget[i];
			if (starget != NULL) {
				ahd->platform_data->starget[i] = NULL;
			}
		}

		if (ahd->platform_data->irq != AHD_LINUX_NOIRQ)
			free_irq(ahd->platform_data->irq, ahd);
		if (ahd->tags[0] == BUS_SPACE_PIO
		 && ahd->bshs[0].ioport != 0)
			release_region(ahd->bshs[0].ioport, 256);
		if (ahd->tags[1] == BUS_SPACE_PIO
		 && ahd->bshs[1].ioport != 0)
			release_region(ahd->bshs[1].ioport, 256);
		if (ahd->tags[0] == BUS_SPACE_MEMIO
		 && ahd->bshs[0].maddr != NULL) {
			iounmap(ahd->bshs[0].maddr);
			release_mem_region(ahd->platform_data->mem_busaddr,
					   0x1000);
		}
		if (ahd->platform_data->host)
			scsi_host_put(ahd->platform_data->host);

		kfree(ahd->platform_data);
	}
}

void
ahd_platform_init(struct ahd_softc *ahd)
{
	/*
	 * Lookup and commit any modified IO Cell options.
	 */
	if (ahd->unit < ARRAY_SIZE(aic79xx_iocell_info)) {
		const struct ahd_linux_iocell_opts *iocell_opts;

		iocell_opts = &aic79xx_iocell_info[ahd->unit];
		if (iocell_opts->precomp != AIC79XX_DEFAULT_PRECOMP)
			AHD_SET_PRECOMP(ahd, iocell_opts->precomp);
		if (iocell_opts->slewrate != AIC79XX_DEFAULT_SLEWRATE)
			AHD_SET_SLEWRATE(ahd, iocell_opts->slewrate);
		if (iocell_opts->amplitude != AIC79XX_DEFAULT_AMPLITUDE)
			AHD_SET_AMPLITUDE(ahd, iocell_opts->amplitude);
	}

}

void
ahd_platform_freeze_devq(struct ahd_softc *ahd, struct scb *scb)
{
	ahd_platform_abort_scbs(ahd, SCB_GET_TARGET(ahd, scb),
				SCB_GET_CHANNEL(ahd, scb),
				SCB_GET_LUN(scb), SCB_LIST_NULL,
				ROLE_UNKNOWN, CAM_REQUEUE_REQ);
}

void
ahd_platform_set_tags(struct ahd_softc *ahd, struct scsi_device *sdev,
		      struct ahd_devinfo *devinfo, ahd_queue_alg alg)
{
	struct ahd_linux_device *dev;
	int was_queuing;
	int now_queuing;

	if (sdev == NULL)
		return;

	dev = scsi_transport_device_data(sdev);

	if (dev == NULL)
		return;
	was_queuing = dev->flags & (AHD_DEV_Q_BASIC|AHD_DEV_Q_TAGGED);
	switch (alg) {
	default:
	case AHD_QUEUE_NONE:
		now_queuing = 0;
		break; 
	case AHD_QUEUE_BASIC:
		now_queuing = AHD_DEV_Q_BASIC;
		break;
	case AHD_QUEUE_TAGGED:
		now_queuing = AHD_DEV_Q_TAGGED;
		break;
	}
	if ((dev->flags & AHD_DEV_FREEZE_TIL_EMPTY) == 0
	 && (was_queuing != now_queuing)
	 && (dev->active != 0)) {
		dev->flags |= AHD_DEV_FREEZE_TIL_EMPTY;
		dev->qfrozen++;
	}

	dev->flags &= ~(AHD_DEV_Q_BASIC|AHD_DEV_Q_TAGGED|AHD_DEV_PERIODIC_OTAG);
	if (now_queuing) {
		u_int usertags;

		usertags = ahd_linux_user_tagdepth(ahd, devinfo);
		if (!was_queuing) {
			/*
			 * Start out aggressively and allow our
			 * dynamic queue depth algorithm to take
			 * care of the rest.
			 */
			dev->maxtags = usertags;
			dev->openings = dev->maxtags - dev->active;
		}
		if (dev->maxtags == 0) {
			/*
			 * Queueing is disabled by the user.
			 */
			dev->openings = 1;
		} else if (alg == AHD_QUEUE_TAGGED) {
			dev->flags |= AHD_DEV_Q_TAGGED;
			if (aic79xx_periodic_otag != 0)
				dev->flags |= AHD_DEV_PERIODIC_OTAG;
		} else
			dev->flags |= AHD_DEV_Q_BASIC;
	} else {
		/* We can only have one opening. */
		dev->maxtags = 0;
		dev->openings =  1 - dev->active;
	}

	switch ((dev->flags & (AHD_DEV_Q_BASIC|AHD_DEV_Q_TAGGED))) {
	case AHD_DEV_Q_BASIC:
	case AHD_DEV_Q_TAGGED:
		scsi_change_queue_depth(sdev,
				dev->openings + dev->active);
		break;
	default:
		/*
		 * We allow the OS to queue 2 untagged transactions to
		 * us at any time even though we can only execute them
		 * serially on the controller/device.  This should
		 * remove some latency.
		 */
		scsi_change_queue_depth(sdev, 1);
		break;
	}
}

int
ahd_platform_abort_scbs(struct ahd_softc *ahd, int target, char channel,
			int lun, u_int tag, role_t role, uint32_t status)
{
	return 0;
}

static u_int
ahd_linux_user_tagdepth(struct ahd_softc *ahd, struct ahd_devinfo *devinfo)
{
	static int warned_user;
	u_int tags;

	tags = 0;
	if ((ahd->user_discenable & devinfo->target_mask) != 0) {
		if (ahd->unit >= ARRAY_SIZE(aic79xx_tag_info)) {

			if (warned_user == 0) {
				printk(KERN_WARNING
"aic79xx: WARNING: Insufficient tag_info instances\n"
"aic79xx: for installed controllers.  Using defaults\n"
"aic79xx: Please update the aic79xx_tag_info array in\n"
"aic79xx: the aic79xx_osm.c source file.\n");
				warned_user++;
			}
			tags = AHD_MAX_QUEUE;
		} else {
			adapter_tag_info_t *tag_info;

			tag_info = &aic79xx_tag_info[ahd->unit];
			tags = tag_info->tag_commands[devinfo->target_offset];
			if (tags > AHD_MAX_QUEUE)
				tags = AHD_MAX_QUEUE;
		}
	}
	return (tags);
}

/*
 * Determines the queue depth for a given device.
 */
static void
ahd_linux_device_queue_depth(struct scsi_device *sdev)
{
	struct	ahd_devinfo devinfo;
	u_int	tags;
	struct ahd_softc *ahd = *((struct ahd_softc **)sdev->host->hostdata);

	ahd_compile_devinfo(&devinfo,
			    ahd->our_id,
			    sdev->sdev_target->id, sdev->lun,
			    sdev->sdev_target->channel == 0 ? 'A' : 'B',
			    ROLE_INITIATOR);
	tags = ahd_linux_user_tagdepth(ahd, &devinfo);
	if (tags != 0 && sdev->tagged_supported != 0) {

		ahd_platform_set_tags(ahd, sdev, &devinfo, AHD_QUEUE_TAGGED);
		ahd_send_async(ahd, devinfo.channel, devinfo.target,
			       devinfo.lun, AC_TRANSFER_NEG);
		ahd_print_devinfo(ahd, &devinfo);
		printk("Tagged Queuing enabled.  Depth %d\n", tags);
	} else {
		ahd_platform_set_tags(ahd, sdev, &devinfo, AHD_QUEUE_NONE);
		ahd_send_async(ahd, devinfo.channel, devinfo.target,
			       devinfo.lun, AC_TRANSFER_NEG);
	}
}

static int
ahd_linux_run_command(struct ahd_softc *ahd, struct ahd_linux_device *dev,
		      struct scsi_cmnd *cmd)
{
	struct	 scb *scb;
	struct	 hardware_scb *hscb;
	struct	 ahd_initiator_tinfo *tinfo;
	struct	 ahd_tmode_tstate *tstate;
	u_int	 col_idx;
	uint16_t mask;
	unsigned long flags;
	int nseg;

	nseg = scsi_dma_map(cmd);
	if (nseg < 0)
		return SCSI_MLQUEUE_HOST_BUSY;

	ahd_lock(ahd, &flags);

	/*
	 * Get an scb to use.
	 */
	tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
				    cmd->device->id, &tstate);
	if ((dev->flags & (AHD_DEV_Q_TAGGED|AHD_DEV_Q_BASIC)) == 0
	 || (tinfo->curr.ppr_options & MSG_EXT_PPR_IU_REQ) != 0) {
		col_idx = AHD_NEVER_COL_IDX;
	} else {
		col_idx = AHD_BUILD_COL_IDX(cmd->device->id,
					    cmd->device->lun);
	}
	if ((scb = ahd_get_scb(ahd, col_idx)) == NULL) {
		ahd->flags |= AHD_RESOURCE_SHORTAGE;
		ahd_unlock(ahd, &flags);
		scsi_dma_unmap(cmd);
		return SCSI_MLQUEUE_HOST_BUSY;
	}

	scb->io_ctx = cmd;
	scb->platform_data->dev = dev;
	hscb = scb->hscb;
	cmd->host_scribble = (char *)scb;

	/*
	 * Fill out basics of the HSCB.
	 */
	hscb->control = 0;
	hscb->scsiid = BUILD_SCSIID(ahd, cmd);
	hscb->lun = cmd->device->lun;
	scb->hscb->task_management = 0;
	mask = SCB_GET_TARGET_MASK(ahd, scb);

	if ((ahd->user_discenable & mask) != 0)
		hscb->control |= DISCENB;

	if ((tinfo->curr.ppr_options & MSG_EXT_PPR_IU_REQ) != 0)
		scb->flags |= SCB_PACKETIZED;

	if ((tstate->auto_negotiate & mask) != 0) {
		scb->flags |= SCB_AUTO_NEGOTIATE;
		scb->hscb->control |= MK_MESSAGE;
	}

	if ((dev->flags & (AHD_DEV_Q_TAGGED|AHD_DEV_Q_BASIC)) != 0) {
		if (dev->commands_since_idle_or_otag == AHD_OTAG_THRESH
		 && (dev->flags & AHD_DEV_Q_TAGGED) != 0) {
			hscb->control |= MSG_ORDERED_TASK;
			dev->commands_since_idle_or_otag = 0;
		} else {
			hscb->control |= MSG_SIMPLE_TASK;
		}
	}

	hscb->cdb_len = cmd->cmd_len;
	memcpy(hscb->shared_data.idata.cdb, cmd->cmnd, hscb->cdb_len);

	scb->platform_data->xfer_len = 0;
	ahd_set_residual(scb, 0);
	ahd_set_sense_residual(scb, 0);
	scb->sg_count = 0;

	if (nseg > 0) {
		void *sg = scb->sg_list;
		struct scatterlist *cur_seg;
		int i;

		scb->platform_data->xfer_len = 0;

		scsi_for_each_sg(cmd, cur_seg, nseg, i) {
			dma_addr_t addr;
			bus_size_t len;

			addr = sg_dma_address(cur_seg);
			len = sg_dma_len(cur_seg);
			scb->platform_data->xfer_len += len;
			sg = ahd_sg_setup(ahd, scb, sg, addr, len,
					  i == (nseg - 1));
		}
	}

	LIST_INSERT_HEAD(&ahd->pending_scbs, scb, pending_links);
	dev->openings--;
	dev->active++;
	dev->commands_issued++;

	if ((dev->flags & AHD_DEV_PERIODIC_OTAG) != 0)
		dev->commands_since_idle_or_otag++;
	scb->flags |= SCB_ACTIVE;
	ahd_queue_scb(ahd, scb);

	ahd_unlock(ahd, &flags);

	return 0;
}

/*
 * SCSI controller interrupt handler.
 */
irqreturn_t
ahd_linux_isr(int irq, void *dev_id)
{
	struct	ahd_softc *ahd;
	u_long	flags;
	int	ours;

	ahd = (struct ahd_softc *) dev_id;
	ahd_lock(ahd, &flags); 
	ours = ahd_intr(ahd);
	ahd_unlock(ahd, &flags);
	return IRQ_RETVAL(ours);
}

void
ahd_send_async(struct ahd_softc *ahd, char channel,
	       u_int target, u_int lun, ac_code code)
{
	switch (code) {
	case AC_TRANSFER_NEG:
	{
		struct  scsi_target *starget;
		struct	ahd_initiator_tinfo *tinfo;
		struct	ahd_tmode_tstate *tstate;
		unsigned int target_ppr_options;

		BUG_ON(target == CAM_TARGET_WILDCARD);

		tinfo = ahd_fetch_transinfo(ahd, channel, ahd->our_id,
					    target, &tstate);

		/*
		 * Don't bother reporting results while
		 * negotiations are still pending.
		 */
		if (tinfo->curr.period != tinfo->goal.period
		 || tinfo->curr.width != tinfo->goal.width
		 || tinfo->curr.offset != tinfo->goal.offset
		 || tinfo->curr.ppr_options != tinfo->goal.ppr_options)
			if (bootverbose == 0)
				break;

		/*
		 * Don't bother reporting results that
		 * are identical to those last reported.
		 */
		starget = ahd->platform_data->starget[target];
		if (starget == NULL)
			break;

		target_ppr_options =
			(spi_dt(starget) ? MSG_EXT_PPR_DT_REQ : 0)
			+ (spi_qas(starget) ? MSG_EXT_PPR_QAS_REQ : 0)
			+ (spi_iu(starget) ?  MSG_EXT_PPR_IU_REQ : 0)
			+ (spi_rd_strm(starget) ? MSG_EXT_PPR_RD_STRM : 0)
			+ (spi_pcomp_en(starget) ? MSG_EXT_PPR_PCOMP_EN : 0)
			+ (spi_rti(starget) ? MSG_EXT_PPR_RTI : 0)
			+ (spi_wr_flow(starget) ? MSG_EXT_PPR_WR_FLOW : 0)
			+ (spi_hold_mcs(starget) ? MSG_EXT_PPR_HOLD_MCS : 0);

		if (tinfo->curr.period == spi_period(starget)
		    && tinfo->curr.width == spi_width(starget)
		    && tinfo->curr.offset == spi_offset(starget)
		 && tinfo->curr.ppr_options == target_ppr_options)
			if (bootverbose == 0)
				break;

		spi_period(starget) = tinfo->curr.period;
		spi_width(starget) = tinfo->curr.width;
		spi_offset(starget) = tinfo->curr.offset;
		spi_dt(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_DT_REQ ? 1 : 0;
		spi_qas(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_QAS_REQ ? 1 : 0;
		spi_iu(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_IU_REQ ? 1 : 0;
		spi_rd_strm(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_RD_STRM ? 1 : 0;
		spi_pcomp_en(starget) =  tinfo->curr.ppr_options & MSG_EXT_PPR_PCOMP_EN ? 1 : 0;
		spi_rti(starget) =  tinfo->curr.ppr_options &  MSG_EXT_PPR_RTI ? 1 : 0;
		spi_wr_flow(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_WR_FLOW ? 1 : 0;
		spi_hold_mcs(starget) = tinfo->curr.ppr_options & MSG_EXT_PPR_HOLD_MCS ? 1 : 0;
		spi_display_xfer_agreement(starget);
		break;
	}
        case AC_SENT_BDR:
	{
		WARN_ON(lun != CAM_LUN_WILDCARD);
		scsi_report_device_reset(ahd->platform_data->host,
					 channel - 'A', target);
		break;
	}
        case AC_BUS_RESET:
		if (ahd->platform_data->host != NULL) {
			scsi_report_bus_reset(ahd->platform_data->host,
					      channel - 'A');
		}
                break;
        default:
                panic("ahd_send_async: Unexpected async event");
        }
}

/*
 * Calls the higher level scsi done function and frees the scb.
 */
void
ahd_done(struct ahd_softc *ahd, struct scb *scb)
{
	struct scsi_cmnd *cmd;
	struct	  ahd_linux_device *dev;

	if ((scb->flags & SCB_ACTIVE) == 0) {
		printk("SCB %d done'd twice\n", SCB_GET_TAG(scb));
		ahd_dump_card_state(ahd);
		panic("Stopping for safety");
	}
	LIST_REMOVE(scb, pending_links);
	cmd = scb->io_ctx;
	dev = scb->platform_data->dev;
	dev->active--;
	dev->openings++;
	if ((cmd->result & (CAM_DEV_QFRZN << 16)) != 0) {
		cmd->result &= ~(CAM_DEV_QFRZN << 16);
		dev->qfrozen--;
	}
	ahd_linux_unmap_scb(ahd, scb);

	/*
	 * Guard against stale sense data.
	 * The Linux mid-layer assumes that sense
	 * was retrieved anytime the first byte of
	 * the sense buffer looks "sane".
	 */
	cmd->sense_buffer[0] = 0;
	if (ahd_get_transaction_status(scb) == CAM_REQ_INPROG) {
		uint32_t amount_xferred;

		amount_xferred =
		    ahd_get_transfer_length(scb) - ahd_get_residual(scb);
		if ((scb->flags & SCB_TRANSMISSION_ERROR) != 0) {
#ifdef AHD_DEBUG
			if ((ahd_debug & AHD_SHOW_MISC) != 0) {
				ahd_print_path(ahd, scb);
				printk("Set CAM_UNCOR_PARITY\n");
			}
#endif
			ahd_set_transaction_status(scb, CAM_UNCOR_PARITY);
#ifdef AHD_REPORT_UNDERFLOWS
		/*
		 * This code is disabled by default as some
		 * clients of the SCSI system do not properly
		 * initialize the underflow parameter.  This
		 * results in spurious termination of commands
		 * that complete as expected (e.g. underflow is
		 * allowed as command can return variable amounts
		 * of data.
		 */
		} else if (amount_xferred < scb->io_ctx->underflow) {
			u_int i;

			ahd_print_path(ahd, scb);
			printk("CDB:");
			for (i = 0; i < scb->io_ctx->cmd_len; i++)
				printk(" 0x%x", scb->io_ctx->cmnd[i]);
			printk("\n");
			ahd_print_path(ahd, scb);
			printk("Saw underflow (%ld of %ld bytes). "
			       "Treated as error\n",
				ahd_get_residual(scb),
				ahd_get_transfer_length(scb));
			ahd_set_transaction_status(scb, CAM_DATA_RUN_ERR);
#endif
		} else {
			ahd_set_transaction_status(scb, CAM_REQ_CMP);
		}
	} else if (ahd_get_transaction_status(scb) == CAM_SCSI_STATUS_ERROR) {
		ahd_linux_handle_scsi_status(ahd, cmd->device, scb);
	}

	if (dev->openings == 1
	 && ahd_get_transaction_status(scb) == CAM_REQ_CMP
	 && ahd_get_scsi_status(scb) != SCSI_STATUS_QUEUE_FULL)
		dev->tag_success_count++;
	/*
	 * Some devices deal with…