patch-2.4.19 linux-2.4.19/drivers/scsi/aic7xxx/aic7xxx_osm.c

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diff -urN linux-2.4.18/drivers/scsi/aic7xxx/aic7xxx_osm.c linux-2.4.19/drivers/scsi/aic7xxx/aic7xxx_osm.c
@@ -0,0 +1,3038 @@
+/*
+ * Adaptec AIC7xxx device driver for Linux.
+ *
+ * $Id: //depot/aic7xxx/linux/drivers/scsi/aic7xxx/aic7xxx_osm.c#103 $
+ *
+ * Copyright (c) 1994 John Aycock
+ *   The University of Calgary Department of Computer Science.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Sources include the Adaptec 1740 driver (aha1740.c), the Ultrastor 24F
+ * driver (ultrastor.c), various Linux kernel source, the Adaptec EISA
+ * config file (!adp7771.cfg), the Adaptec AHA-2740A Series User's Guide,
+ * the Linux Kernel Hacker's Guide, Writing a SCSI Device Driver for Linux,
+ * the Adaptec 1542 driver (aha1542.c), the Adaptec EISA overlay file
+ * (adp7770.ovl), the Adaptec AHA-2740 Series Technical Reference Manual,
+ * the Adaptec AIC-7770 Data Book, the ANSI SCSI specification, the
+ * ANSI SCSI-2 specification (draft 10c), ...
+ *
+ * --------------------------------------------------------------------------
+ *
+ *  Modifications by Daniel M. Eischen (deischen@iworks.InterWorks.org):
+ *
+ *  Substantially modified to include support for wide and twin bus
+ *  adapters, DMAing of SCBs, tagged queueing, IRQ sharing, bug fixes,
+ *  SCB paging, and other rework of the code.
+ *
+ * --------------------------------------------------------------------------
+ * Copyright (c) 1994-2000 Justin T. Gibbs.
+ * Copyright (c) 2000-2001 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.
+ *
+ *---------------------------------------------------------------------------
+ *
+ *  Thanks also go to (in alphabetical order) the following:
+ *
+ *    Rory Bolt     - Sequencer bug fixes
+ *    Jay Estabrook - Initial DEC Alpha support
+ *    Doug Ledford  - Much needed abort/reset bug fixes
+ *    Kai Makisara  - DMAing of SCBs
+ *
+ *  A Boot time option was also added for not resetting the scsi bus.
+ *
+ *    Form:  aic7xxx=extended
+ *           aic7xxx=no_reset
+ *           aic7xxx=verbose
+ *
+ *  Daniel M. Eischen, deischen@iworks.InterWorks.org, 1/23/97
+ *
+ *  Id: aic7xxx.c,v 4.1 1997/06/12 08:23:42 deang Exp
+ */
+
+/*
+ * Further driver modifications made by Doug Ledford <dledford@redhat.com>
+ *
+ * Copyright (c) 1997-1999 Doug Ledford
+ *
+ * These changes are released under the same licensing terms as the FreeBSD
+ * driver written by Justin Gibbs.  Please see his Copyright notice above
+ * for the exact terms and conditions covering my changes as well as the
+ * warranty statement.
+ *
+ * Modifications made to the aic7xxx.c,v 4.1 driver from Dan Eischen include
+ * but are not limited to:
+ *
+ *  1: Import of the latest FreeBSD sequencer code for this driver
+ *  2: Modification of kernel code to accomodate different sequencer semantics
+ *  3: Extensive changes throughout kernel portion of driver to improve
+ *     abort/reset processing and error hanndling
+ *  4: Other work contributed by various people on the Internet
+ *  5: Changes to printk information and verbosity selection code
+ *  6: General reliability related changes, especially in IRQ management
+ *  7: Modifications to the default probe/attach order for supported cards
+ *  8: SMP friendliness has been improved
+ *
+ */
+
+/*
+ * This is the only file where module.h should
+ * embed module global version info.
+ */
+#define AHC_MODVERSION_FILE
+
+#include "aic7xxx_osm.h"
+#include "aic7xxx_inline.h"
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,0)
+#include <linux/init.h>		/* __setup */
+#endif
+
+#include "../sd.h"		/* For geometry detection */
+
+#include <linux/mm.h>		/* For fetching system memory size */
+#include <linux/blk.h>		/* For block_size() */
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0)
+/*
+ * Lock protecting manipulation of the ahc softc list.
+ */
+spinlock_t ahc_list_spinlock;
+#endif
+
+/*
+ * To generate the correct addresses for the controller to issue
+ * on the bus.  Originally added for DEC Alpha support.
+ */
+#define VIRT_TO_BUS(a) (uint32_t)virt_to_bus((void *)(a))
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,0)
+struct proc_dir_entry proc_scsi_aic7xxx = {
+	PROC_SCSI_AIC7XXX, 7, "aic7xxx",
+	S_IFDIR | S_IRUGO | S_IXUGO, 2,
+	0, 0, 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL
+};
+#endif
+
+/*
+ * 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_AIC7XXX_RESET_DELAY_MS
+#define AIC7XXX_RESET_DELAY CONFIG_AIC7XXX_RESET_DELAY_MS
+#else
+#define AIC7XXX_RESET_DELAY 5000
+#endif
+
+/*
+ * Control collection of SCSI transfer statistics for the /proc filesystem.
+ *
+ * NOTE: Do NOT enable this when running on kernels version 1.2.x and below.
+ * NOTE: This does affect performance since it has to maintain statistics.
+ */
+#ifdef CONFIG_AIC7XXX_PROC_STATS
+#define AIC7XXX_PROC_STATS
+#endif
+
+/*
+ * To change the default number of tagged transactions allowed per-device,
+ * add a line to the lilo.conf file like:
+ * append="aic7xxx=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 {
+	uint8_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 aic7xxx 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 aic7xxx_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_AIC7XXX_CMDS_PER_DEVICE
+#define AIC7XXX_CMDS_PER_DEVICE CONFIG_AIC7XXX_CMDS_PER_DEVICE
+#else
+#define AIC7XXX_CMDS_PER_DEVICE AHC_MAX_QUEUE
+#endif
+
+#define AIC7XXX_CONFIGED_TAG_COMMANDS {					\
+	AIC7XXX_CMDS_PER_DEVICE, AIC7XXX_CMDS_PER_DEVICE,		\
+	AIC7XXX_CMDS_PER_DEVICE, AIC7XXX_CMDS_PER_DEVICE,		\
+	AIC7XXX_CMDS_PER_DEVICE, AIC7XXX_CMDS_PER_DEVICE,		\
+	AIC7XXX_CMDS_PER_DEVICE, AIC7XXX_CMDS_PER_DEVICE,		\
+	AIC7XXX_CMDS_PER_DEVICE, AIC7XXX_CMDS_PER_DEVICE,		\
+	AIC7XXX_CMDS_PER_DEVICE, AIC7XXX_CMDS_PER_DEVICE,		\
+	AIC7XXX_CMDS_PER_DEVICE, AIC7XXX_CMDS_PER_DEVICE,		\
+	AIC7XXX_CMDS_PER_DEVICE, AIC7XXX_CMDS_PER_DEVICE		\
+}
+
+/*
+ * By default, use the number of commands specified by
+ * the users kernel configuration.
+ */
+static adapter_tag_info_t aic7xxx_tag_info[] =
+{
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS},
+	{AIC7XXX_CONFIGED_TAG_COMMANDS}
+};
+
+/*
+ * 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
+ahc_print_path(struct ahc_softc *ahc, struct scb *scb)
+{
+	printk("(scsi%d:%c:%d:%d): ",
+	       ahc->platform_data->host->host_no,
+	       scb != NULL ? SCB_GET_CHANNEL(ahc, scb) : 'X',
+	       scb != NULL ? SCB_GET_TARGET(ahc, scb) : -1,
+	       scb != NULL ? SCB_GET_LUN(scb) : -1);
+}
+
+/*
+ * XXX - these options apply unilaterally to _all_ 274x/284x/294x
+ *       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 aic7xxx_no_reset;
+
+/*
+ * Certain PCI motherboards will scan PCI devices from highest to lowest,
+ * others scan from lowest to highest, and they tend to do all kinds of
+ * strange things when they come into contact with PCI bridge chips.  The
+ * net result of all this is that the PCI card that is actually used to boot
+ * the machine is very hard to detect.  Most motherboards go from lowest
+ * PCI slot number to highest, and the first SCSI controller found is the
+ * one you boot from.  The only exceptions to this are when a controller
+ * has its BIOS disabled.  So, we by default sort all of our SCSI controllers
+ * from lowest PCI slot number to highest PCI slot number.  We also force
+ * all controllers with their BIOS disabled to the end of the list.  This
+ * works on *almost* all computers.  Where it doesn't work, we have this
+ * option.  Setting this option to non-0 will reverse the order of the sort
+ * to highest first, then lowest, but will still leave cards with their BIOS
+ * disabled at the very end.  That should fix everyone up unless there are
+ * really strange cirumstances.
+ */
+static int aic7xxx_reverse_scan = 0;
+
+/*
+ * 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 aic7xxx_extended = 0;
+
+/*
+ * 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
+ *  -1 = Normal polarity pci parity checking
+ *   1 = reverse polarity pci parity checking
+ *
+ * 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 int aic7xxx_pci_parity = 0;
+
+/*
+ * Certain newer motherboards have put new PCI based devices into the
+ * IO spaces that used to typically be occupied by VLB or EISA cards.
+ * This overlap can cause these newer motherboards to lock up when scanned
+ * for older EISA and VLB devices.  Setting this option to non-0 will
+ * cause the driver to skip scanning for any VLB or EISA controllers and
+ * only support the PCI controllers.  NOTE: this means that if the kernel
+ * os compiled with PCI support disabled, then setting this to non-0
+ * would result in never finding any devices :)
+ */
+#ifndef CONFIG_AIC7XXX_PROBE_EISA_VL
+#define CONFIG_AIC7XXX_PROBE_EISA_VL n
+#endif
+#if CONFIG_AIC7XXX_PROBE_EISA_VL == n
+static int aic7xxx_no_probe = 1;
+#else
+static int aic7xxx_no_probe;
+#endif
+
+/*
+ * aic7xxx_detect() has been run, so register all device arrivals
+ * immediately with the system rather than deferring to the sorted
+ * attachment performed by aic7xxx_detect().
+ */
+int aic7xxx_detect_complete;
+
+/*
+ * 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 int aic7xxx_seltime = 0x00;
+
+/*
+ * 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.
+ */
+int aic7xxx_periodic_otag;
+
+/*
+ * Module information and settable options.
+ */
+#ifdef MODULE
+static char *aic7xxx = NULL;
+/*
+ * Just in case someone uses commas to separate items on the insmod
+ * command line, we define a dummy buffer here to avoid having insmod
+ * write wild stuff into our code segment
+ */
+static char dummy_buffer[60] = "Please don't trounce on me insmod!!\n";
+
+MODULE_AUTHOR("Maintainer: Justin T. Gibbs <gibbs@scsiguy.com>");
+MODULE_DESCRIPTION("Adaptec Aic77XX/78XX SCSI Host Bus Adapter driver");
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,10)
+MODULE_LICENSE("Dual BSD/GPL");
+#endif
+MODULE_PARM(aic7xxx, "s");
+MODULE_PARM_DESC(aic7xxx, "period delimited, options string.
+	verbose			Enable verbose/diagnostic logging
+	no_probe		Disable EISA/VLB controller probing
+	no_reset		Supress initial bus resets
+	extended		Enable extended geometry on all controllers
+	periodic_otag		Send an ordered tagged transaction periodically
+				to prevent tag starvation.  This may be
+				required by some older disk drives/RAID arrays. 
+	reverse_scan		Sort PCI devices highest Bus/Slot to lowest
+	tag_info:<tag_str>	Set per-target tag depth
+	seltime:<int>		Selection Timeout(0/256ms,1/128ms,2/64ms,3/32ms)
+
+	Sample /etc/modules.conf line:
+		Enable verbose logging
+		Disable EISA/VLB probing
+		Set tag depth on Controller 2/Target 2 to 10 tags
+		Shorten the selection timeout to 128ms from its default of 256
+
+	options aic7xxx='\"verbose.no_probe.tag_info:{{}.{}.{..10}}.seltime:1\"'
+");
+#endif
+
+static void ahc_linux_handle_scsi_status(struct ahc_softc *,
+					 struct ahc_linux_device *,
+					 struct scb *);
+static void ahc_linux_filter_command(struct ahc_softc*, Scsi_Cmnd*,
+				     struct scb*);
+static void ahc_linux_sem_timeout(u_long arg);
+static void ahc_linux_freeze_sim_queue(struct ahc_softc *ahc);
+static void ahc_linux_release_sim_queue(u_long arg);
+static void ahc_linux_dev_timed_unfreeze(u_long arg);
+static int  ahc_linux_queue_recovery_cmd(Scsi_Cmnd *cmd, scb_flag flag);
+static void ahc_linux_initialize_scsi_bus(struct ahc_softc *ahc);
+static void ahc_linux_select_queue_depth(struct Scsi_Host *host,
+					 Scsi_Device *scsi_devs);
+static u_int ahc_linux_user_tagdepth(struct ahc_softc *ahc,
+				     struct ahc_devinfo *devinfo);
+static void ahc_linux_device_queue_depth(struct ahc_softc *ahc,
+					 Scsi_Device *device);
+static struct ahc_linux_target*	ahc_linux_alloc_target(struct ahc_softc*,
+						       u_int, u_int);
+static void			ahc_linux_free_target(struct ahc_softc*,
+						      struct ahc_linux_target*);
+static struct ahc_linux_device*	ahc_linux_alloc_device(struct ahc_softc*,
+						       struct ahc_linux_target*,
+						       u_int);
+static void			ahc_linux_free_device(struct ahc_softc*,
+						      struct ahc_linux_device*);
+static void ahc_linux_run_device_queue(struct ahc_softc*,
+				       struct ahc_linux_device*);
+static void ahc_linux_setup_tag_info(char *p, char *end);
+static int ahc_linux_next_unit(void);
+static void ahc_runq_tasklet(unsigned long data);
+static int ahc_linux_halt(struct notifier_block *nb, u_long event, void *buf);
+
+static __inline struct ahc_linux_device*
+		     ahc_linux_get_device(struct ahc_softc *ahc, u_int channel,
+					  u_int target, u_int lun, int alloc);
+static __inline void ahc_linux_queue_cmd_complete(struct ahc_softc *ahc,
+						  Scsi_Cmnd *cmd);
+static __inline void ahc_linux_run_complete_queue(struct ahc_softc *ahc,
+						  struct ahc_cmd *acmd);
+static __inline void ahc_linux_check_device_queue(struct ahc_softc *ahc,
+						  struct ahc_linux_device *dev);
+static __inline struct ahc_linux_device *
+		     ahc_linux_next_device_to_run(struct ahc_softc *ahc);
+static __inline void ahc_linux_run_device_queues(struct ahc_softc *ahc);
+static __inline void ahc_linux_sniff_command(struct ahc_softc*, Scsi_Cmnd*,
+					     struct scb*);
+static __inline void ahc_linux_unmap_scb(struct ahc_softc*, struct scb*);
+
+static __inline int ahc_linux_map_seg(struct ahc_softc *ahc, struct scb *scb,
+		 		      struct ahc_dma_seg *sg,
+				      bus_addr_t addr, bus_size_t len);
+
+static __inline struct ahc_linux_device*
+ahc_linux_get_device(struct ahc_softc *ahc, u_int channel, u_int target,
+	       u_int lun, int alloc)
+{
+	struct ahc_linux_target *targ;
+	struct ahc_linux_device *dev;
+	u_int target_offset;
+
+	target_offset = target;
+	if (channel != 0)
+		target_offset += 8;
+	targ = ahc->platform_data->targets[target_offset];
+	if (targ == NULL) {
+		if (alloc != 0) {
+			targ = ahc_linux_alloc_target(ahc, channel, target);
+			if (targ == NULL)
+				return (NULL);
+		} else
+			return (NULL);
+	}
+	dev = targ->devices[lun];
+	if (dev == NULL && alloc != 0)
+		dev = ahc_linux_alloc_device(ahc, targ, lun);
+	return (dev);
+}
+
+static __inline void
+ahc_linux_queue_cmd_complete(struct ahc_softc *ahc, Scsi_Cmnd *cmd)
+{
+	/*
+	 * Typically, the complete queue has very few entries
+	 * queued to it before the queue is emptied by
+	 * ahc_linux_run_complete_queue, so sorting the entries
+	 * by generation number should be inexpensive.
+	 * We perform the sort so that commands that complete
+	 * with an error are retuned in the order origionally
+	 * queued to the controller so that any subsequent retries
+	 * are performed in order.  The underlying ahc routines do
+	 * not guarantee the order that aborted commands will be
+	 * returned to us.
+	 */
+	struct ahc_completeq *completeq;
+	struct ahc_cmd *list_cmd;
+	struct ahc_cmd *acmd;
+
+	/*
+	 * If we want the request requeued, make sure there
+	 * are sufficent retries.  In the old scsi error code,
+	 * we used to be able to specify a result code that
+	 * bypassed the retry count.  Now we must use this
+	 * hack.
+	 */
+	if (cmd->result == (CAM_REQUEUE_REQ << 16))
+		cmd->retries--;
+	completeq = &ahc->platform_data->completeq;
+	list_cmd = TAILQ_FIRST(completeq);
+	acmd = (struct ahc_cmd *)cmd;
+	while (list_cmd != NULL
+	    && acmd_scsi_cmd(list_cmd).serial_number
+	     < acmd_scsi_cmd(acmd).serial_number)
+		list_cmd = TAILQ_NEXT(list_cmd, acmd_links.tqe);
+	if (list_cmd != NULL)
+		TAILQ_INSERT_BEFORE(list_cmd, acmd, acmd_links.tqe);
+	else
+		TAILQ_INSERT_TAIL(completeq, acmd, acmd_links.tqe);
+}
+
+static __inline void
+ahc_linux_run_complete_queue(struct ahc_softc *ahc, struct ahc_cmd *acmd)
+{	
+	u_long done_flags;
+
+	ahc_done_lock(ahc, &done_flags);
+	while (acmd != NULL) {
+		Scsi_Cmnd *cmd;
+
+		cmd = &acmd_scsi_cmd(acmd);
+		acmd = TAILQ_NEXT(acmd, acmd_links.tqe);
+		cmd->host_scribble = NULL;
+		cmd->scsi_done(cmd);
+	}
+	ahc_done_unlock(ahc, &done_flags);
+}
+
+static __inline void
+ahc_linux_check_device_queue(struct ahc_softc *ahc,
+			     struct ahc_linux_device *dev)
+{
+	if ((dev->flags & AHC_DEV_FREEZE_TIL_EMPTY) != 0
+	 && dev->active == 0) {
+		dev->flags &= ~AHC_DEV_FREEZE_TIL_EMPTY;
+		dev->qfrozen--;
+	}
+
+	if (TAILQ_FIRST(&dev->busyq) == NULL
+	 || dev->openings == 0 || dev->qfrozen != 0)
+		return;
+
+	ahc_linux_run_device_queue(ahc, dev);
+}
+
+static __inline struct ahc_linux_device *
+ahc_linux_next_device_to_run(struct ahc_softc *ahc)
+{
+	
+	if ((ahc->flags & AHC_RESOURCE_SHORTAGE) != 0
+	 || ahc->platform_data->qfrozen != 0)
+		return (NULL);
+	return (TAILQ_FIRST(&ahc->platform_data->device_runq));
+}
+
+static __inline void
+ahc_linux_run_device_queues(struct ahc_softc *ahc)
+{
+	struct ahc_linux_device *dev;
+
+	while ((dev = ahc_linux_next_device_to_run(ahc)) != NULL) {
+		TAILQ_REMOVE(&ahc->platform_data->device_runq, dev, links);
+		dev->flags &= ~AHC_DEV_ON_RUN_LIST;
+		ahc_linux_check_device_queue(ahc, dev);
+	}
+}
+
+static __inline void
+ahc_linux_sniff_command(struct ahc_softc *ahc, Scsi_Cmnd *cmd, struct scb *scb)
+{
+	/*
+	 * Determine whether we care to filter
+	 * information out of this command.  If so,
+	 * pass it on to ahc_linux_filter_command() for more
+	 * heavy weight processing.
+	 */
+	if (cmd->cmnd[0] == INQUIRY)
+		ahc_linux_filter_command(ahc, cmd, scb);
+}
+
+static __inline void
+ahc_linux_unmap_scb(struct ahc_softc *ahc, struct scb *scb)
+{
+	Scsi_Cmnd *cmd;
+
+	cmd = scb->io_ctx;
+	ahc_sync_sglist(ahc, scb, BUS_DMASYNC_POSTWRITE);
+	if (cmd->use_sg != 0) {
+		struct scatterlist *sg;
+
+		sg = (struct scatterlist *)cmd->request_buffer;
+		pci_unmap_sg(ahc->dev_softc, sg, cmd->use_sg,
+			     scsi_to_pci_dma_dir(cmd->sc_data_direction));
+	} else if (cmd->request_bufflen != 0) {
+		pci_unmap_single(ahc->dev_softc,
+				 scb->platform_data->buf_busaddr,
+				 cmd->request_bufflen,
+				 scsi_to_pci_dma_dir(cmd->sc_data_direction));
+	}
+}
+
+static __inline int
+ahc_linux_map_seg(struct ahc_softc *ahc, struct scb *scb,
+		  struct ahc_dma_seg *sg, bus_addr_t addr, bus_size_t len)
+{
+	int	 consumed;
+
+	if ((scb->sg_count + 1) > AHC_NSEG)
+		panic("Too few segs for dma mapping.  "
+		      "Increase AHC_NSEG\n");
+
+	consumed = 1;
+	sg->addr = ahc_htole32(addr & 0xFFFFFFFF);
+	scb->platform_data->xfer_len += len;
+	if (sizeof(bus_addr_t) > 4
+	 && (ahc->flags & AHC_39BIT_ADDRESSING) != 0) {
+		/*
+		 * Due to DAC restrictions, we can't
+		 * cross a 4GB boundary.
+		 */
+		if ((addr ^ (addr + len - 1)) & ~0xFFFFFFFF) {
+			struct	 ahc_dma_seg *next_sg;
+			uint32_t next_len;
+
+			printf("Crossed Seg\n");
+			if ((scb->sg_count + 2) > AHC_NSEG)
+				panic("Too few segs for dma mapping.  "
+				      "Increase AHC_NSEG\n");
+
+			consumed++;
+			next_sg = sg + 1;
+			next_sg->addr = 0;
+			next_len = 0x100000000 - (addr & 0xFFFFFFFF);
+			len -= next_len;
+			next_len |= ((addr >> 8) + 0x1000000) & 0x7F000000;
+			next_sg->len = ahc_htole32(next_len);
+		}
+		len |= (addr >> 8) & 0x7F000000;
+	}
+	sg->len = ahc_htole32(len);
+	return (consumed);
+}
+
+/**************************** Tasklet Handler *********************************/
+
+static void
+ahc_runq_tasklet(unsigned long data)
+{
+	struct ahc_softc* ahc;
+	struct ahc_linux_device *dev;
+	u_long flags;
+
+	ahc = (struct ahc_softc *)data;
+	ahc_lock(ahc, &flags);
+	while ((dev = ahc_linux_next_device_to_run(ahc)) != NULL) {
+	
+		TAILQ_REMOVE(&ahc->platform_data->device_runq, dev, links);
+		dev->flags &= ~AHC_DEV_ON_RUN_LIST;
+		ahc_linux_check_device_queue(ahc, dev);
+		/* Yeild to our interrupt handler */
+		ahc_unlock(ahc, &flags);
+		ahc_lock(ahc, &flags);
+	}
+	ahc_unlock(ahc, &flags);
+}
+
+/************************ Shutdown/halt/reboot hook ***************************/
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+
+static struct notifier_block ahc_linux_notifier = {
+	ahc_linux_halt, NULL, 0
+};
+
+static int ahc_linux_halt(struct notifier_block *nb, u_long event, void *buf)
+{
+	struct ahc_softc *ahc;
+
+	if (event == SYS_DOWN || event == SYS_HALT) {
+		TAILQ_FOREACH(ahc, &ahc_tailq, links) {
+			ahc_shutdown(ahc);
+		}
+	}
+	return (NOTIFY_OK);
+}
+
+/******************************** Macros **************************************/
+#define BUILD_SCSIID(ahc, cmd)						\
+	((((cmd)->target << TID_SHIFT) & TID)				\
+	| (((cmd)->channel == 0) ? (ahc)->our_id : (ahc)->our_id_b)	\
+	| (((cmd)->channel == 0) ? 0 : TWIN_CHNLB))
+
+/******************************** Bus DMA *************************************/
+int
+ahc_dma_tag_create(struct ahc_softc *ahc, bus_dma_tag_t parent,
+		   bus_size_t alignment, bus_size_t boundary,
+		   bus_addr_t lowaddr, bus_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 = malloc(sizeof(*dmat), M_DEVBUF, M_NOWAIT);
+	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
+ahc_dma_tag_destroy(struct ahc_softc *ahc, bus_dma_tag_t dmat)
+{
+	free(dmat, M_DEVBUF);
+}
+
+int
+ahc_dmamem_alloc(struct ahc_softc *ahc, bus_dma_tag_t dmat, void** vaddr,
+		 int flags, bus_dmamap_t *mapp)
+{
+	bus_dmamap_t map;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,0)
+	map = malloc(sizeof(*map), M_DEVBUF, M_NOWAIT);
+	if (map == NULL)
+		return (ENOMEM);
+	/*
+	 * Although we can dma data above 4GB, our
+	 * "consistent" memory is below 4GB for
+	 * space efficiency reasons (only need a 4byte
+	 * address).  For this reason, we have to reset
+	 * our dma mask when doing allocations.
+	 */
+	if (ahc->dev_softc != NULL) {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,3)
+		pci_set_dma_mask(ahc->dev_softc, 0xFFFFFFFF);
+#else
+		ahc->dev_softc->dma_mask = 0xFFFFFFFF;
+#endif
+	}
+	*vaddr = pci_alloc_consistent(ahc->dev_softc,
+				      dmat->maxsize, &map->bus_addr);
+	if (ahc->dev_softc != NULL) {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,3)
+		pci_set_dma_mask(ahc->dev_softc,
+				 ahc->platform_data->hw_dma_mask);
+#else
+		ahc->dev_softc->dma_mask = ahc->platform_data->hw_dma_mask;
+#endif
+	}
+#else /* LINUX_VERSION_CODE < KERNEL_VERSION(2,3,0) */
+	/*
+	 * At least in 2.2.14, malloc is a slab allocator so all
+	 * allocations are aligned.  We assume for these kernel versions
+	 * that all allocations will be bellow 4Gig, physically contiguous,
+	 * and accessable via DMA by the controller.
+	 */
+	map = NULL; /* No additional information to store */
+	*vaddr = malloc(dmat->maxsize, M_DEVBUF, M_NOWAIT);
+#endif
+	if (*vaddr == NULL)
+		return (ENOMEM);
+	*mapp = map;
+	return(0);
+}
+
+void
+ahc_dmamem_free(struct ahc_softc *ahc, bus_dma_tag_t dmat,
+		void* vaddr, bus_dmamap_t map)
+{
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,0)
+	pci_free_consistent(ahc->dev_softc, dmat->maxsize,
+			    vaddr, map->bus_addr);
+#else
+	free(vaddr, M_DEVBUF);
+#endif
+}
+
+int
+ahc_dmamap_load(struct ahc_softc *ahc, 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;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,0)
+	stack_sg.ds_addr = map->bus_addr;
+#else
+	stack_sg.ds_addr = VIRT_TO_BUS(buf);
+#endif
+	stack_sg.ds_len = dmat->maxsize;
+	cb(cb_arg, &stack_sg, /*nseg*/1, /*error*/0);
+	return (0);
+}
+
+void
+ahc_dmamap_destroy(struct ahc_softc *ahc, bus_dma_tag_t dmat, bus_dmamap_t map)
+{
+	/*
+	 * The map may is NULL in our < 2.3.X implementation.
+	 */
+	if (map != NULL)
+		free(map, M_DEVBUF);
+}
+
+int
+ahc_dmamap_unload(struct ahc_softc *ahc, bus_dma_tag_t dmat, bus_dmamap_t map)
+{
+	/* Nothing to do */
+	return (0);
+}
+
+/********************* Platform Dependent Functions ***************************/
+int
+ahc_softc_comp(struct ahc_softc *lahc, struct ahc_softc *rahc)
+{
+	int	value;
+	int	rvalue;
+	int	lvalue;
+
+	/*
+	 * Under Linux, cards are ordered as follows:
+	 *	1) VLB/EISA BIOS enabled devices sorted by BIOS address.
+	 *	2) PCI devices with BIOS enabled sorted by bus/slot/func.
+	 *	3) All remaining VLB/EISA devices sorted by ioport.
+	 *	4) All remaining PCI devices sorted by bus/slot/func.
+	 */
+	value = (lahc->flags & AHC_BIOS_ENABLED)
+	      - (rahc->flags & AHC_BIOS_ENABLED);
+	if (value != 0)
+		/* Controllers with BIOS enabled have a *higher* priority */
+		return (-value);
+
+	/*
+	 * Same BIOS setting, now sort based on bus type.
+	 * EISA and VL controllers sort together.  EISA/VL
+	 * have higher priority than PCI.
+	 */
+	rvalue = (rahc->chip & AHC_BUS_MASK);
+ 	if (rvalue == AHC_VL)
+		rvalue = AHC_EISA;
+	lvalue = (lahc->chip & AHC_BUS_MASK);
+ 	if (lvalue == AHC_VL)
+		lvalue = AHC_EISA;
+	value = lvalue - rvalue;
+	if (value != 0)
+		return (value);
+
+	/* Still equal.  Sort by BIOS address, ioport, or bus/slot/func. */
+	switch (rvalue) {
+	case AHC_PCI:
+	{
+		char primary_channel;
+
+		if (aic7xxx_reverse_scan != 0)
+			value = ahc_get_pci_bus(rahc->dev_softc)
+			      - ahc_get_pci_bus(lahc->dev_softc);
+		else
+			value = ahc_get_pci_bus(lahc->dev_softc)
+			      - ahc_get_pci_bus(rahc->dev_softc);
+		if (value != 0)
+			break;
+		if (aic7xxx_reverse_scan != 0)
+			value = ahc_get_pci_slot(rahc->dev_softc)
+			      - ahc_get_pci_slot(lahc->dev_softc);
+		else
+			value = ahc_get_pci_slot(lahc->dev_softc)
+			      - ahc_get_pci_slot(rahc->dev_softc);
+		if (value != 0)
+			break;
+		/*
+		 * On multi-function devices, the user can choose
+		 * to have function 1 probed before function 0.
+		 * Give whichever channel is the primary channel
+		 * the lowest priority.
+		 */
+		primary_channel = (lahc->flags & AHC_PRIMARY_CHANNEL) + 'A';
+		value = 1;
+		if (lahc->channel == primary_channel)
+			value = -1;
+		break;
+	}
+	case AHC_EISA:
+		if ((rahc->flags & AHC_BIOS_ENABLED) != 0) {
+			value = lahc->platform_data->bios_address
+			      - rahc->platform_data->bios_address; 
+		} else {
+			value = lahc->bsh.ioport
+			      - rahc->bsh.ioport; 
+		}
+		break;
+	default:
+		panic("ahc_softc_sort: invalid bus type");
+	}
+	return (value);
+}
+
+static void
+ahc_linux_setup_tag_info(char *p, char *end)
+{
+	char	*base;
+	char	*tok;
+	char	*tok_end;
+	char	*tok_end2;
+	int      i;
+	int      instance;
+	int	 targ;
+	int	 done;
+	char	 tok_list[] = {'.', ',', '{', '}', '\0'};
+
+	if (*p != ':')
+		return;
+
+	instance = -1;
+	targ = -1;
+	done = FALSE;
+	base = p;
+	/* Forward us just past the ':' */
+	tok = base + 1;
+	tok_end = strchr(tok, '\0');
+	if (tok_end < end)
+		*tok_end = ',';
+	while (!done) {
+		switch (*tok) {
+		case '{':
+			if (instance == -1)
+				instance = 0;
+			else if (targ == -1)
+				targ = 0;
+			tok++;
+			break;
+		case '}':
+			if (targ != -1)
+				targ = -1;
+			else if (instance != -1)
+				instance = -1;
+			tok++;
+			break;
+		case ',':
+		case '.':
+			if (instance == -1)
+				done = TRUE;
+			else if (targ >= 0)
+				targ++;
+			else if (instance >= 0)
+				instance++;
+			if ((targ >= AHC_NUM_TARGETS) ||
+			    (instance >= NUM_ELEMENTS(aic7xxx_tag_info)))
+				done = TRUE;
+			tok++;
+			if (!done) {
+				base = tok;
+			}
+			break;
+		case '\0':
+			done = TRUE;
+			break;
+		default:
+			done = TRUE;
+			tok_end = strchr(tok, '\0');
+			for (i = 0; tok_list[i]; i++) {
+				tok_end2 = strchr(tok, tok_list[i]);
+				if ((tok_end2) && (tok_end2 < tok_end)) {
+					tok_end = tok_end2;
+					done = FALSE;
+				}
+			}
+			if ((instance >= 0) && (targ >= 0)
+			 && (instance < NUM_ELEMENTS(aic7xxx_tag_info))
+			 && (targ < AHC_NUM_TARGETS)) {
+				aic7xxx_tag_info[instance].tag_commands[targ] =
+				    simple_strtoul(tok, NULL, 0) & 0xff;
+			}
+			tok = tok_end;
+			break;
+		}
+	}
+	while ((p != base) && (p != NULL))
+		p = strtok(NULL, ",.");
+}
+
+/*
+ * Handle Linux boot parameters. This routine allows for assigning a value
+ * to a parameter with a ':' between the parameter and the value.
+ * ie. aic7xxx=stpwlev:1,extended
+ */
+int
+aic7xxx_setup(char *s)
+{
+	int	i, n;
+	char   *p;
+	char   *end;
+
+	static struct {
+		const char *name;
+		uint32_t *flag;
+	} options[] = {
+		{ "extended", &aic7xxx_extended },
+		{ "no_reset", &aic7xxx_no_reset },
+		{ "verbose", &aic7xxx_verbose },
+		{ "reverse_scan", &aic7xxx_reverse_scan },
+		{ "no_probe", &aic7xxx_no_probe },
+		{ "periodic_otag", &aic7xxx_periodic_otag },
+		{ "pci_parity", &aic7xxx_pci_parity },
+		{ "seltime", &aic7xxx_seltime },
+		{ "tag_info", NULL }
+	};
+
+	end = strchr(s, '\0');
+
+	for (p = strtok(s, ",."); p; p = strtok(NULL, ",.")) {
+		for (i = 0; i < NUM_ELEMENTS(options); i++) {
+			n = strlen(options[i].name);
+
+			if (strncmp(options[i].name, p, n) != 0)
+				continue;
+
+			if (strncmp(p, "tag_info", n) == 0) {
+				ahc_linux_setup_tag_info(p + n, end);
+			} 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) = ~(*(options[i].flag));
+			}
+			break;
+		}
+	}
+	return 1;
+}
+
+#if LINUX_VERSION_CODE > KERNEL_VERSION(2,3,0)
+__setup("aic7xxx=", aic7xxx_setup);
+#endif
+
+int aic7xxx_verbose;
+
+/*
+ * Try to detect an Adaptec 7XXX controller.
+ */
+int
+ahc_linux_detect(Scsi_Host_Template *template)
+{
+	struct	ahc_softc *ahc;
+	int     found;
+
+	/*
+	 * It is a bug that the upper layer takes
+	 * this lock just prior to calling us.
+	 */
+	spin_unlock_irq(&io_request_lock);
+
+	/*
+	 * Sanity checking of Linux SCSI data structures so
+	 * that some of our hacks^H^H^H^H^Hassumptions aren't
+	 * violated.
+	 */
+	if (offsetof(struct ahc_cmd_internal, end)
+	  > offsetof(struct scsi_cmnd, host_scribble)) {
+		printf("ahc_linux_detect: SCSI data structures changed.\n");
+		printf("ahc_linux_detect: Unable to attach\n");
+		return (0);
+	}
+#ifdef MODULE
+	/*
+	 * If we've been passed any parameters, process them now.
+	 */
+	if (aic7xxx)
+		aic7xxx_setup(aic7xxx);
+	if (dummy_buffer[0] != 'P')
+		printk(KERN_WARNING
+"aic7xxx: Please read the file /usr/src/linux/drivers/scsi/README.aic7xxx\n"
+"aic7xxx: to see the proper way to specify options to the aic7xxx module\n"
+"aic7xxx: Specifically, don't use any commas when passing arguments to\n"
+"aic7xxx: insmod or else it might trash certain memory areas.\n");
+#endif
+
+#if LINUX_VERSION_CODE > KERNEL_VERSION(2,3,0)
+	template->proc_name = "aic7xxx";
+#else
+	template->proc_dir = &proc_scsi_aic7xxx;
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,7)
+	/*
+	 * We can only map 16MB per-SG
+	 * so create a sector limit of
+	 * "16MB" in 2K sectors.
+	 */
+	template->max_sectors = 8192;
+#endif
+
+	/*
+	 * Initialize our softc list lock prior to
+	 * probing for any adapters.
+	 */
+	ahc_list_lockinit();
+
+#ifdef CONFIG_PCI
+	ahc_linux_pci_probe(template);
+#endif
+
+	if (aic7xxx_no_probe == 0)
+		aic7770_linux_probe(template);
+
+	/*
+	 * Register with the SCSI layer all
+	 * controllers we've found.
+	 */
+	spin_lock_irq(&io_request_lock);
+	found = 0;
+	TAILQ_FOREACH(ahc, &ahc_tailq, links) {
+
+		if (ahc_linux_register_host(ahc, template) == 0)
+			found++;
+	}
+	aic7xxx_detect_complete++;
+	return (found);
+}
+
+int
+ahc_linux_register_host(struct ahc_softc *ahc, Scsi_Host_Template *template)
+{
+	char  buf[80];
+	struct Scsi_Host *host;
+	char *new_name;
+	u_long s;
+
+
+	template->name = ahc->description;
+	host = scsi_register(template, sizeof(struct ahc_softc *));
+	if (host == NULL)
+		return (ENOMEM);
+
+	ahc_lock(ahc, &s);
+	*((struct ahc_softc **)host->hostdata) = ahc;
+	ahc->platform_data->host = host;
+	host->can_queue = AHC_MAX_QUEUE;
+	host->cmd_per_lun = 2;
+	host->sg_tablesize = AHC_NSEG;
+	host->select_queue_depths = ahc_linux_select_queue_depth;
+	/* XXX No way to communicate the ID for multiple channels */
+	host->this_id = ahc->our_id;
+	host->irq = ahc->platform_data->irq;
+	host->max_id = (ahc->features & AHC_WIDE) ? 16 : 8;
+	host->max_lun = AHC_NUM_LUNS;
+	host->max_channel = (ahc->features & AHC_TWIN) ? 1 : 0;
+	ahc_set_unit(ahc, ahc_linux_next_unit());
+	sprintf(buf, "scsi%d", host->host_no);
+	new_name = malloc(strlen(buf) + 1, M_DEVBUF, M_NOWAIT);
+	if (new_name != NULL) {
+		strcpy(new_name, buf);
+		ahc_set_name(ahc, new_name);
+	}
+	host->unique_id = ahc->unit;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,4)
+	scsi_set_pci_device(host, ahc->dev_softc);
+#endif
+	ahc_linux_initialize_scsi_bus(ahc);
+	ahc_unlock(ahc, &s);
+	return (0);
+}
+
+uint64_t
+ahc_linux_get_memsize()
+{
+	struct sysinfo si;
+
+	si_meminfo(&si);
+	return (si.totalram << PAGE_SHIFT);
+}
+
+/*
+ * Find the smallest available unit number to use
+ * for a new device.  We don't just use a static
+ * count to handle the "repeated hot-(un)plug"
+ * scenario.
+ */
+static int
+ahc_linux_next_unit()
+{
+	struct ahc_softc *ahc;
+	int unit;
+
+	unit = 0;
+retry:
+	TAILQ_FOREACH(ahc, &ahc_tailq, links) {
+		if (ahc->unit == unit) {
+			unit++;
+			goto retry;
+		}
+	}
+	return (unit);
+}
+
+/*
+ * Place the SCSI bus into a known state by either resetting it,
+ * or forcing transfer negotiations on the next command to any
+ * target.
+ */
+void
+ahc_linux_initialize_scsi_bus(struct ahc_softc *ahc)
+{
+	int i;
+	int numtarg;
+
+	i = 0;
+	numtarg = 0;
+
+	if (aic7xxx_no_reset != 0)
+		ahc->flags &= ~(AHC_RESET_BUS_A|AHC_RESET_BUS_B);
+
+	if ((ahc->flags & AHC_RESET_BUS_A) != 0)
+		ahc_reset_channel(ahc, 'A', /*initiate_reset*/TRUE);
+	else
+		numtarg = (ahc->features & AHC_WIDE) ? 16 : 8;
+
+	if ((ahc->features & AHC_TWIN) != 0) {
+
+		if ((ahc->flags & AHC_RESET_BUS_B) != 0) {
+			ahc_reset_channel(ahc, 'B', /*initiate_reset*/TRUE);
+		} else {
+			if (numtarg == 0)
+				i = 8;
+			numtarg += 8;
+		}
+	}
+
+	for (; i < numtarg; i++) {
+		struct ahc_devinfo devinfo;
+		struct ahc_initiator_tinfo *tinfo;
+		struct ahc_tmode_tstate *tstate;
+		u_int our_id;
+		u_int target_id;
+		char channel;
+
+		channel = 'A';
+		our_id = ahc->our_id;
+		target_id = i;
+		if (i > 7 && (ahc->features & AHC_TWIN) != 0) {
+			channel = 'B';
+			our_id = ahc->our_id_b;
+			target_id = i % 8;
+		}
+		tinfo = ahc_fetch_transinfo(ahc, channel, our_id,
+					    target_id, &tstate);
+		tinfo->goal = tinfo->user;
+		/*
+		 * Don't try negotiations that require PPR messages
+		 * until we successfully retrieve Inquiry data.
+		 */
+		tinfo->goal.ppr_options = 0;
+		if (tinfo->goal.transport_version > SCSI_REV_2)
+			tinfo->goal.transport_version = SCSI_REV_2;
+		ahc_compile_devinfo(&devinfo, our_id, target_id,
+				   CAM_LUN_WILDCARD, channel, ROLE_INITIATOR);
+		ahc_update_neg_request(ahc, &devinfo, tstate,
+				       tinfo, /*force*/FALSE);
+	}
+	/* Give the bus some time to recover */
+	if ((ahc->flags & (AHC_RESET_BUS_A|AHC_RESET_BUS_B)) != 0) {
+		ahc_linux_freeze_sim_queue(ahc);
+		init_timer(&ahc->platform_data->reset_timer);
+		ahc->platform_data->reset_timer.data = (u_long)ahc;
+		ahc->platform_data->reset_timer.expires =
+		    jiffies + (AIC7XXX_RESET_DELAY * HZ)/1000;
+		ahc->platform_data->reset_timer.function =
+		    ahc_linux_release_sim_queue;
+		add_timer(&ahc->platform_data->reset_timer);
+	}
+}
+
+int
+ahc_platform_alloc(struct ahc_softc *ahc, void *platform_arg)
+{
+	ahc->platform_data =
+	    malloc(sizeof(struct ahc_platform_data), M_DEVBUF, M_NOWAIT);
+	if (ahc->platform_data == NULL)
+		return (ENOMEM);
+	memset(ahc->platform_data, 0, sizeof(struct ahc_platform_data));
+	TAILQ_INIT(&ahc->platform_data->completeq);
+	TAILQ_INIT(&ahc->platform_data->device_runq);
+	ahc->platform_data->irq = AHC_LINUX_NOIRQ;
+	ahc->platform_data->hw_dma_mask = 0xFFFFFFFF;
+	ahc_lockinit(ahc);
+	ahc_done_lockinit(ahc);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,0)
+	init_MUTEX_LOCKED(&ahc->platform_data->eh_sem);
+#else
+	ahc->platform_data->eh_sem = MUTEX_LOCKED;
+#endif
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
+	tasklet_init(&ahc->platform_data->runq_tasklet, ahc_runq_tasklet,
+		     (unsigned long)ahc);
+#endif
+	ahc->seltime = (aic7xxx_seltime & 0x3) << 4;
+	ahc->seltime_b = (aic7xxx_seltime & 0x3) << 4;
+	if (TAILQ_EMPTY(&ahc_tailq))
+		register_reboot_notifier(&ahc_linux_notifier);
+	return (0);
+}
+
+void
+ahc_platform_free(struct ahc_softc *ahc)
+{
+	if (ahc->platform_data != NULL) {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
+		tasklet_kill(&ahc->platform_data->runq_tasklet);
+#endif
+		if (ahc->platform_data->host != NULL)
+			scsi_unregister(ahc->platform_data->host);
+		if (ahc->platform_data->irq != AHC_LINUX_NOIRQ)
+			free_irq(ahc->platform_data->irq, ahc);
+		if (ahc->tag == BUS_SPACE_PIO
+		 && ahc->bsh.ioport != 0)
+			release_region(ahc->bsh.ioport, 256);
+		if (ahc->tag == BUS_SPACE_MEMIO
+		 && ahc->bsh.maddr != NULL) {
+			u_long base_addr;
+
+			base_addr = (u_long)ahc->bsh.maddr;
+			base_addr &= PAGE_MASK;
+			iounmap((void *)base_addr);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
+			release_mem_region(ahc->platform_data->mem_busaddr,
+					   0x1000);
+#endif
+		}
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
+		/* XXX Need an instance detach in the PCI code */
+		if (ahc->dev_softc != NULL)
+			ahc->dev_softc->driver = NULL;
+#endif
+		free(ahc->platform_data, M_DEVBUF);
+	}
+	if (TAILQ_EMPTY(&ahc_tailq)) {
+		unregister_reboot_notifier(&ahc_linux_notifier);
+#ifdef CONFIG_PCI
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
+		pci_unregister_driver(&aic7xxx_pci_driver);
+#endif
+#endif
+	}
+}
+
+void
+ahc_platform_freeze_devq(struct ahc_softc *ahc, struct scb *scb)
+{
+	ahc_platform_abort_scbs(ahc, SCB_GET_TARGET(ahc, scb),
+				SCB_GET_CHANNEL(ahc, scb),
+				SCB_GET_LUN(scb), SCB_LIST_NULL,
+				ROLE_UNKNOWN, CAM_REQUEUE_REQ);
+}
+
+void
+ahc_platform_set_tags(struct ahc_softc *ahc, struct ahc_devinfo *devinfo,
+		      ahc_queue_alg alg)
+{
+	struct ahc_linux_device *dev;
+	int was_queuing;
+	int now_queuing;
+
+	dev = ahc_linux_get_device(ahc, devinfo->channel - 'A',
+				   devinfo->target,
+				   devinfo->lun, /*alloc*/FALSE);
+	if (dev == NULL)
+		return;
+	was_queuing = dev->flags & (AHC_DEV_Q_BASIC|AHC_DEV_Q_TAGGED);
+	now_queuing = alg != AHC_QUEUE_NONE;
+	if ((dev->flags & AHC_DEV_FREEZE_TIL_EMPTY) == 0
+	 && (was_queuing != now_queuing)
+	 && (dev->active != 0)) {
+		dev->flags |= AHC_DEV_FREEZE_TIL_EMPTY;
+		dev->qfrozen++;
+	}
+
+	dev->flags &= ~(AHC_DEV_Q_BASIC|AHC_DEV_Q_TAGGED|AHC_DEV_PERIODIC_OTAG);
+	if (now_queuing) {
+		u_int usertags;
+
+		usertags = ahc_linux_user_tagdepth(ahc, devinfo);
+		if (!was_queuing) {
+			/*
+			 * Start out agressively and allow our
+			 * dynamic queue depth algorithm to take
+			 * care of the rest.
+			 */
+			dev->maxtags = usertags;
+			dev->openings = dev->maxtags - dev->active;
+		}
+		if (alg == AHC_QUEUE_TAGGED) {
+			dev->flags |= AHC_DEV_Q_TAGGED;
+			if (aic7xxx_periodic_otag != 0)
+				dev->flags |= AHC_DEV_PERIODIC_OTAG;
+		} else
+			dev->flags |= AHC_DEV_Q_BASIC;
+	} else {
+		/* We can only have one opening. */
+		dev->maxtags = 0;
+		dev->openings =  1 - dev->active;
+	}
+}
+
+int
+ahc_platform_abort_scbs(struct ahc_softc *ahc, int target, char channel,
+			int lun, u_int tag, role_t role, uint32_t status)
+{
+	int chan;
+	int maxchan;
+	int targ;
+	int maxtarg;
+	int clun;
+	int maxlun;
+	int count;
+
+	if (tag != SCB_LIST_NULL)
+		return (0);
+
+	chan = 0;
+	if (channel != ALL_CHANNELS) {
+		chan = channel - 'A';
+		maxchan = chan + 1;
+	} else {
+		maxchan = (ahc->features & AHC_TWIN) ? 2 : 1;
+	}
+	targ = 0;
+	if (target != CAM_TARGET_WILDCARD) {
+		targ = target;
+		maxtarg = targ + 1;
+	} else {
+		maxtarg = (ahc->features & AHC_WIDE) ? 16 : 8;
+	}
+	clun = 0;
+	if (lun != CAM_LUN_WILDCARD) {
+		clun = lun;
+		maxlun = clun + 1;
+	} else {
+		maxlun = AHC_NUM_LUNS;
+	}
+
+	count = 0;
+	for (; chan < maxchan; chan++) {
+
+		for (; targ < maxtarg; targ++) {
+
+			for (; clun < maxlun; clun++) {
+				struct ahc_linux_device *dev;
+				struct ahc_busyq *busyq;
+				struct ahc_cmd *acmd;
+
+				dev = ahc_linux_get_device(ahc, chan,
+							   targ, clun,
+							   /*alloc*/FALSE);
+				if (dev == NULL)
+					continue;
+
+				busyq = &dev->busyq;
+				while ((acmd = TAILQ_FIRST(busyq)) != NULL) {
+					Scsi_Cmnd *cmd;
+
+					cmd = &acmd_scsi_cmd(acmd);
+					TAILQ_REMOVE(busyq, acmd,
+						     acmd_links.tqe);
+					count++;
+					cmd->result = status << 16;
+					ahc_linux_queue_cmd_complete(ahc, cmd);
+				}
+			}
+		}
+	}
+
+	return (count);
+}
+
+/*
+ * Sets the queue depth for each SCSI device hanging
+ * off the input host adapter.
+ */
+static void
+ahc_linux_select_queue_depth(struct Scsi_Host * host,
+			     Scsi_Device * scsi_devs)
+{
+	Scsi_Device *device;
+	struct	ahc_softc *ahc;
+	u_long	flags;
+	int	scbnum;
+
+	ahc = *((struct ahc_softc **)host->hostdata);
+	ahc_lock(ahc, &flags);
+	scbnum = 0;
+	for (device = scsi_devs; device != NULL; device = device->next) {
+		if (device->host == host) {
+			ahc_linux_device_queue_depth(ahc, device);
+			scbnum += device->queue_depth;
+		}
+	}
+	ahc_unlock(ahc, &flags);
+}
+
+static u_int
+ahc_linux_user_tagdepth(struct ahc_softc *ahc, struct ahc_devinfo *devinfo)
+{
+	static int warned_user;
+	u_int tags;
+
+	tags = 0;
+	if ((ahc->user_discenable & devinfo->target_mask) != 0) {
+		if (warned_user == 0
+		 && ahc->unit >= NUM_ELEMENTS(aic7xxx_tag_info)) {
+
+			printf("aic7xxx: WARNING, insufficient "
+			       "tag_info instances for installed "
+			       "controllers. Using defaults\n");
+			printf("aic7xxx: Please update the "
+			       "aic7xxx_tag_info array in the "
+			       "aic7xxx.c source file.\n");
+			tags = AHC_MAX_QUEUE;
+			warned_user++;
+		} else {
+			adapter_tag_info_t *tag_info;
+
+			tag_info = &aic7xxx_tag_info[ahc->unit];
+			tags = tag_info->tag_commands[devinfo->target_offset];
+			if (tags > AHC_MAX_QUEUE)
+				tags = AHC_MAX_QUEUE;
+		}
+	}
+	return (tags);
+}
+
+/*
+ * Determines the queue depth for a given device.
+ */
+static void
+ahc_linux_device_queue_depth(struct ahc_softc *ahc, Scsi_Device * device)
+{
+	struct	ahc_devinfo devinfo;
+	u_int	tags;
+
+	ahc_compile_devinfo(&devinfo,
+			    device->channel == 0 ? ahc->our_id : ahc->our_id_b,
+			    device->id, device->lun,
+			    device->channel == 0 ? 'A' : 'B',
+			    ROLE_INITIATOR);
+	tags = ahc_linux_user_tagdepth(ahc, &devinfo);
+	if (tags != 0
+	 && device->tagged_supported != 0) {
+
+		device->queue_depth = tags;
+		ahc_set_tags(ahc, &devinfo, AHC_QUEUE_TAGGED);
+		printf("scsi%d:%c:%d:%d: Tagged Queuing enabled.  Depth %d\n",
+	       	       ahc->platform_data->host->host_no, devinfo.channel,
+		       devinfo.target, devinfo.lun, tags);
+	} else {
+		/*
+		 * 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.
+		 */
+		device->queue_depth = 2;
+	}
+}
+
+/*
+ * Queue an SCB to the controller.
+ */
+int
+ahc_linux_queue(Scsi_Cmnd * cmd, void (*scsi_done) (Scsi_Cmnd *))
+{
+	struct	 ahc_softc *ahc;
+	struct	 ahc_linux_device *dev;
+	u_long	 flags;
+
+	ahc = *(struct ahc_softc **)cmd->host->hostdata;
+
+	/*
+	 * Save the callback on completion function.
+	 */
+	cmd->scsi_done = scsi_done;
+
+	ahc_lock(ahc, &flags);
+	dev = ahc_linux_get_device(ahc, cmd->channel, cmd->target,
+				   cmd->lun, /*alloc*/TRUE);
+	if (dev == NULL) {
+		ahc_unlock(ahc, &flags);
+		printf("aic7xxx_linux_queue: Unable to allocate device!\n");
+		return (-ENOMEM);
+	}
+	cmd->result = CAM_REQ_INPROG << 16;
+	TAILQ_INSERT_TAIL(&dev->busyq, (struct ahc_cmd *)cmd, acmd_links.tqe);
+	if ((dev->flags & AHC_DEV_ON_RUN_LIST) == 0) {
+		TAILQ_INSERT_TAIL(&ahc->platform_data->device_runq, dev, links);
+		dev->flags |= AHC_DEV_ON_RUN_LIST;
+		ahc_linux_run_device_queues(ahc);
+	}
+	ahc_unlock(ahc, &flags);
+	return (0);
+}
+
+static void
+ahc_linux_run_device_queue(struct ahc_softc *ahc, struct ahc_linux_device *dev)
+{
+	struct	 ahc_cmd *acmd;
+	struct	 scsi_cmnd *cmd;
+	struct	 scb *scb;
+	struct	 hardware_scb *hscb;
+	struct	 ahc_initiator_tinfo *tinfo;
+	struct	 ahc_tmode_tstate *tstate;
+	uint16_t mask;
+
+	if ((dev->flags & AHC_DEV_ON_RUN_LIST) != 0)
+		panic("running device on run list");
+
+	while ((acmd = TAILQ_FIRST(&dev->busyq)) != NULL
+	    && dev->openings > 0 && dev->qfrozen == 0) {
+
+		/*
+		 * Schedule us to run later.  The only reason we are not
+		 * running is because the whole controller Q is frozen.
+		 */
+		if (ahc->platform_data->qfrozen != 0) {
+
+			TAILQ_INSERT_TAIL(&ahc->platform_data->device_runq,
+					  dev, links);
+			dev->flags |= AHC_DEV_ON_RUN_LIST;
+			return;
+		}
+		/*
+		 * Get an scb to use.
+		 */
+		if ((scb = ahc_get_scb(ahc)) == NULL) {
+			TAILQ_INSERT_TAIL(&ahc->platform_data->device_runq,
+					 dev, links);
+			dev->flags |= AHC_DEV_ON_RUN_LIST;
+			ahc->flags |= AHC_RESOURCE_SHORTAGE;
+			return;
+		}
+		TAILQ_REMOVE(&dev->busyq, acmd, acmd_links.tqe);
+		cmd = &acmd_scsi_cmd(acmd);
+		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(ahc, cmd);
+		hscb->lun = cmd->lun;
+		mask = SCB_GET_TARGET_MASK(ahc, scb);
+		tinfo = ahc_fetch_transinfo(ahc, SCB_GET_CHANNEL(ahc, scb),
+					    SCB_GET_OUR_ID(scb),
+					    SCB_GET_TARGET(ahc, scb), &tstate);
+		hscb->scsirate = tinfo->scsirate;
+		hscb->scsioffset = tinfo->curr.offset;
+		if ((tstate->ultraenb & mask) != 0)
+			hscb->control |= ULTRAENB;
+
+		if ((ahc->user_discenable & mask) != 0)
+			hscb->control |= DISCENB;
+
+		if ((tstate->auto_negotiate & mask) != 0) {
+			scb->flags |= SCB_AUTO_NEGOTIATE;
+			scb->hscb->control |= MK_MESSAGE;
+		}
+
+		if ((dev->flags & (AHC_DEV_Q_TAGGED|AHC_DEV_Q_BASIC)) != 0) {
+			if (dev->commands_since_idle_or_otag == AHC_OTAG_THRESH
+			 && (dev->flags & AHC_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;
+		if (hscb->cdb_len <= 12) {
+			memcpy(hscb->shared_data.cdb, cmd->cmnd, hscb->cdb_len);
+		} else {
+			memcpy(hscb->cdb32, cmd->cmnd, hscb->cdb_len);
+			scb->flags |= SCB_CDB32_PTR;
+		}
+
+		scb->platform_data->xfer_len = 0;
+		ahc_set_residual(scb, 0);
+		ahc_set_sense_residual(scb, 0);
+		scb->sg_count = 0;
+		if (cmd->use_sg != 0) {
+			struct	ahc_dma_seg *sg;
+			struct	scatterlist *cur_seg;
+			struct	scatterlist *end_seg;
+			int	nseg;
+
+			cur_seg = (struct scatterlist *)cmd->request_buffer;
+			nseg = pci_map_sg(ahc->dev_softc, cur_seg, cmd->use_sg,
+				 scsi_to_pci_dma_dir(cmd ->sc_data_direction));
+			end_seg = cur_seg + nseg;
+			/* Copy the segments into the SG list. */
+			sg = scb->sg_list;
+			/*
+			 * The sg_count may be larger than nseg if
+			 * a transfer crosses a 32bit page.
+			 */ 
+			while (cur_seg < end_seg) {
+				bus_addr_t addr;
+				bus_size_t len;
+				int consumed;
+
+				addr = sg_dma_address(cur_seg);
+				len = sg_dma_len(cur_seg);
+				consumed = ahc_linux_map_seg(ahc, scb,
+							     sg, addr, len);
+				sg += consumed;
+				scb->sg_count += consumed;
+				cur_seg++;
+			}
+			sg--;
+			sg->len |= ahc_htole32(AHC_DMA_LAST_SEG);
+
+			/*
+			 * Reset the sg list pointer.
+			 */
+			scb->hscb->sgptr =
+			    ahc_htole32(scb->sg_list_phys | SG_FULL_RESID);
+
+			/*
+			 * Copy the first SG into the "current"
+			 * data pointer area.
+			 */
+			scb->hscb->dataptr = scb->sg_list->addr;
+			scb->hscb->datacnt = scb->sg_list->len;
+		} else if (cmd->request_bufflen != 0) {
+			struct	 ahc_dma_seg *sg;
+			bus_addr_t addr;
+
+			sg = scb->sg_list;
+			addr = pci_map_single(ahc->dev_softc,
+			       cmd->request_buffer,
+			       cmd->request_bufflen,
+			       scsi_to_pci_dma_dir(cmd->sc_data_direction));
+			scb->platform_data->buf_busaddr = addr;
+			scb->sg_count = ahc_linux_map_seg(ahc, scb,
+							  sg, addr,
+							  cmd->request_bufflen);
+			sg->len |= ahc_htole32(AHC_DMA_LAST_SEG);
+
+			/*
+			 * Reset the sg list pointer.
+			 */
+			scb->hscb->sgptr =
+			    ahc_htole32(scb->sg_list_phys | SG_FULL_RESID);
+
+			/*
+			 * Copy the first SG into the "current"
+			 * data pointer area.
+			 */
+			scb->hscb->dataptr = sg->addr;
+			scb->hscb->datacnt = sg->len;
+		} else {
+			scb->hscb->sgptr = ahc_htole32(SG_LIST_NULL);
+			scb->hscb->dataptr = 0;
+			scb->hscb->datacnt = 0;
+			scb->sg_count = 0;
+		}
+
+		ahc_sync_sglist(ahc, scb, BUS_DMASYNC_PREWRITE);
+		LIST_INSERT_HEAD(&ahc->pending_scbs, scb, pending_links);
+		dev->openings--;
+		dev->active++;
+		dev->commands_issued++;
+		if ((dev->flags & AHC_DEV_PERIODIC_OTAG) != 0)
+			dev->commands_since_idle_or_otag++;
+
+		/*
+		 * We only allow one untagged transaction
+		 * per target in the initiator role unless
+		 * we are storing a full busy target *lun*
+		 * table in SCB space.
+		 */
+		if ((scb->hscb->control & (TARGET_SCB|TAG_ENB)) == 0
+		 && (ahc->features & AHC_SCB_BTT) == 0) {
+			struct scb_tailq *untagged_q;
+			int target_offset;
+
+			target_offset = SCB_GET_TARGET_OFFSET(ahc, scb);
+			untagged_q = &(ahc->untagged_queues[target_offset]);
+			TAILQ_INSERT_TAIL(untagged_q, scb, links.tqe);
+			scb->flags |= SCB_UNTAGGEDQ;
+			if (TAILQ_FIRST(untagged_q) != scb)
+				continue;
+		}
+		scb->flags |= SCB_ACTIVE;
+		ahc_queue_scb(ahc, scb);
+	}
+}
+
+/*
+ * SCSI controller interrupt handler.
+ */
+void
+ahc_linux_isr(int irq, void *dev_id, struct pt_regs * regs)
+{
+	struct	ahc_softc *ahc;
+	struct	ahc_cmd *acmd;
+	u_long	flags;
+	struct	ahc_linux_device *next_dev;
+
+	ahc = (struct ahc_softc *) dev_id;
+	ahc_lock(ahc, &flags); 
+	ahc_intr(ahc);
+	acmd = TAILQ_FIRST(&ahc->platform_data->completeq);
+	TAILQ_INIT(&ahc->platform_data->completeq);
+	next_dev = ahc_linux_next_device_to_run(ahc);
+	ahc_unlock(ahc, &flags);
+	if (next_dev) {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
+		tasklet_schedule(&ahc->platform_data->runq_tasklet);
+#else
+		ahc_runq_tasklet((unsigned long)ahc);
+#endif
+	}
+	if (acmd != NULL)
+		ahc_linux_run_complete_queue(ahc, acmd);
+}
+
+void
+ahc_platform_flushwork(struct ahc_softc *ahc)
+{
+	struct ahc_cmd *acmd;
+
+	acmd = TAILQ_FIRST(&ahc->platform_data->completeq);
+	TAILQ_INIT(&ahc->platform_data->completeq);
+	if (acmd != NULL)
+		ahc_linux_run_complete_queue(ahc, acmd);
+}
+
+static struct ahc_linux_target*
+ahc_linux_alloc_target(struct ahc_softc *ahc, u_int channel, u_int target)
+{
+	struct ahc_linux_target *targ;
+	u_int target_offset;
+
+	targ = malloc(sizeof(*targ), M_DEVBUG, M_NOWAIT);
+	if (targ == NULL)
+		return (NULL);
+	memset(targ, 0, sizeof(*targ));
+	targ->channel = channel;
+	targ->target = target;
+	targ->ahc = ahc;
+	target_offset = target;
+	if (channel != 0)
+		target_offset += 8;
+	ahc->platform_data->targets[target_offset] = targ;
+	return (targ);
+}
+
+static void
+ahc_linux_free_target(struct ahc_softc *ahc, struct ahc_linux_target *targ)
+{
+	u_int target_offset;
+
+	target_offset = targ->target;
+	if (targ->channel != 0)
+		target_offset += 8;
+	ahc->platform_data->targets[target_offset] = NULL;
+	free(targ, M_DEVBUF);
+}
+
+static struct ahc_linux_device*
+ahc_linux_alloc_device(struct ahc_softc *ahc,
+		 struct ahc_linux_target *targ, u_int lun)
+{
+	struct ahc_linux_device *dev;
+
+	dev = malloc(sizeof(*dev), M_DEVBUG, M_NOWAIT);
+	if (dev == NULL)
+		return (NULL);
+	memset(dev, 0, sizeof(*dev));
+	init_timer(&dev->timer);
+	TAILQ_INIT(&dev->busyq);
+	dev->flags = AHC_DEV_UNCONFIGURED;
+	dev->lun = lun;
+	dev->target = targ;
+
+	/*
+	 * 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;
+	
+	targ->refcount++;
+	targ->devices[lun] = dev;
+	return (dev);
+}
+
+static void
+ahc_linux_free_device(struct ahc_softc *ahc, struct ahc_linux_device *dev)
+{
+	struct ahc_linux_target *targ;
+
+	del_timer(&dev->timer);
+	targ = dev->target;
+	targ->devices[dev->lun] = NULL;
+	free(dev, M_DEVBUF);
+	targ->refcount--;
+	if (targ->refcount == 0)
+		ahc_linux_free_target(ahc, targ);
+}
+
+/*
+ * Return a string describing the driver.
+ */
+const char *
+ahc_linux_info(struct Scsi_Host *host)
+{
+	static char buffer[512];
+	char	ahc_info[256];
+	char   *bp;
+	struct ahc_softc *ahc;
+
+	bp = &buffer[0];
+	ahc = *(struct ahc_softc **)host->hostdata;
+	memset(bp, 0, sizeof(buffer));
+	strcpy(bp, "Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev ");
+	strcat(bp, AIC7XXX_DRIVER_VERSION);
+	strcat(bp, "\n");
+	strcat(bp, "        <");
+	strcat(bp, ahc->description);
+	strcat(bp, ">\n");
+	strcat(bp, "        ");
+	ahc_controller_info(ahc, ahc_info);
+	strcat(bp, ahc_info);
+	strcat(bp, "\n");
+
+	return (bp);
+}
+
+void
+ahc_send_async(struct ahc_softc *ahc, char channel,
+	       u_int target, u_int lun, ac_code code, void *arg)
+{
+	switch (code) {
+	case AC_TRANSFER_NEG:
+	{
+		char	buf[80];
+		struct	ahc_linux_target *targ;
+		struct	info_str info;
+		struct	ahc_initiator_tinfo *tinfo;
+		struct	ahc_tmode_tstate *tstate;
+		int	target_offset;
+
+		info.buffer = buf;
+		info.length = sizeof(buf);
+		info.offset = 0;
+		info.pos = 0;
+		tinfo = ahc_fetch_transinfo(ahc, channel,
+						channel == 'A' ? ahc->our_id
+							       : ahc->our_id_b,
+						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.
+		 */
+		target_offset = target;
+		if (channel == 'B')
+			target_offset += 8;
+		targ = ahc->platform_data->targets[target_offset];
+		if (targ == NULL)
+			break;
+		if (tinfo->curr.period == targ->last_tinfo.period
+		 && tinfo->curr.width == targ->last_tinfo.width
+		 && tinfo->curr.offset == targ->last_tinfo.offset
+		 && tinfo->curr.ppr_options == targ->last_tinfo.ppr_options)
+			if (bootverbose == 0)
+				break;
+
+		targ->last_tinfo.period = tinfo->curr.period;
+		targ->last_tinfo.width = tinfo->curr.width;
+		targ->last_tinfo.offset = tinfo->curr.offset;
+		targ->last_tinfo.ppr_options = tinfo->curr.ppr_options;
+
+		printf("(%s:%c:", ahc_name(ahc), channel);
+		if (target == CAM_TARGET_WILDCARD)
+			printf("*): ");
+		else
+			printf("%d): ", target);
+		ahc_format_transinfo(&info, &tinfo->curr);
+		if (info.pos < info.length)
+			*info.buffer = '\0';
+		else
+			buf[info.length - 1] = '\0';
+		printf("%s", buf);
+		break;
+	}
+        case AC_SENT_BDR:
+		break;
+        case AC_BUS_RESET:
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,0)
+		if (ahc->platform_data->host != NULL) {
+			scsi_report_bus_reset(ahc->platform_data->host,
+					      channel - 'A');
+		}
+#endif
+                break;
+        default:
+                panic("ahc_send_async: Unexpected async event");
+        }
+}
+
+/*
+ * Calls the higher level scsi done function and frees the scb.
+ */
+void
+ahc_done(struct ahc_softc *ahc, struct scb * scb)
+{
+	Scsi_Cmnd *cmd;
+	struct ahc_linux_device *dev;
+
+	LIST_REMOVE(scb, pending_links);
+	if ((scb->flags & SCB_UNTAGGEDQ) != 0) {
+		struct scb_tailq *untagged_q;
+		int target_offset;
+
+		target_offset = SCB_GET_TARGET_OFFSET(ahc, scb);
+		untagged_q = &(ahc->untagged_queues[target_offset]);
+		TAILQ_REMOVE(untagged_q, scb, links.tqe);
+		ahc_run_untagged_queue(ahc, untagged_q);
+	}
+
+	if ((scb->flags & SCB_ACTIVE) == 0) {
+		printf("SCB %d done'd twice\n", scb->hscb->tag);
+		ahc_dump_card_state(ahc);
+		panic("Stopping for safety");
+	}
+	cmd = scb->io_ctx;
+	dev = scb->platform_data->dev;
+	dev->active--;
+	dev->openings++;
+	ahc_linux_unmap_scb(ahc, scb);
+	if (scb->flags & SCB_SENSE) {
+		memcpy(cmd->sense_buffer, ahc_get_sense_buf(ahc, scb),
+		       MIN(sizeof(struct scsi_sense_data),
+			   sizeof(cmd->sense_buffer)));
+		cmd->result |= (DRIVER_SENSE << 24);
+	} else {
+		/*
+		 * 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 (ahc_get_transaction_status(scb) == CAM_REQ_INPROG) {
+		uint32_t amount_xferred;
+
+		amount_xferred =
+		    ahc_get_transfer_length(scb) - ahc_get_residual(scb);
+		if (amount_xferred < scb->io_ctx->underflow) {
+			printf("Saw underflow (%ld of %ld bytes). "
+			       "Treated as error\n",
+				ahc_get_residual(scb),
+				ahc_get_transfer_length(scb));
+			ahc_set_transaction_status(scb, CAM_DATA_RUN_ERR);
+		} else {
+			ahc_set_transaction_status(scb, CAM_REQ_CMP);
+			ahc_linux_sniff_command(ahc, cmd, scb);
+		}
+	} else if (ahc_get_transaction_status(scb) == DID_OK) {
+		ahc_linux_handle_scsi_status(ahc, dev, scb);
+	} else if (ahc_get_transaction_status(scb) == DID_NO_CONNECT) {
+		/*
+		 * Should a selection timeout kill the device?
+		 * That depends on whether the selection timeout
+		 * is persistent.  Since we have no guarantee that
+		 * the mid-layer will issue an inquiry for this device
+		 * again, we can't just kill it off.
+		dev->flags |= AHC_DEV_UNCONFIGURED;
+		 */
+	}
+
+	if (dev->openings == 1
+	 && ahc_get_transaction_status(scb) == CAM_REQ_CMP
+	 && ahc_get_scsi_status(scb) != SCSI_STATUS_QUEUE_FULL)
+		dev->tag_success_count++;
+	/*
+	 * Some devices deal with temporary internal resource
+	 * shortages by returning queue full.  When the queue
+	 * full occurrs, we throttle back.  Slowly try to get
+	 * back to our previous queue depth.
+	 */
+	if ((dev->openings + dev->active) < dev->maxtags
+	 && dev->tag_success_count > AHC_TAG_SUCCESS_INTERVAL) {
+		dev->tag_success_count = 0;
+		dev->openings++;
+	}
+
+	if (dev->active == 0)
+		dev->commands_since_idle_or_otag = 0;
+
+	if (TAILQ_EMPTY(&dev->busyq)) {
+		if ((dev->flags & AHC_DEV_UNCONFIGURED) != 0
+		 && dev->active == 0)
+			ahc_linux_free_device(ahc, dev);
+	} else if ((dev->flags & AHC_DEV_ON_RUN_LIST) == 0) {
+		TAILQ_INSERT_TAIL(&ahc->platform_data->device_runq, dev, links);
+		dev->flags |= AHC_DEV_ON_RUN_LIST;
+	}
+
+	if ((scb->flags & SCB_RECOVERY_SCB) != 0) {
+		printf("Recovery SCB completes\n");
+		up(&ahc->platform_data->eh_sem);
+	}
+
+	ahc_free_scb(ahc, scb);
+	ahc_linux_queue_cmd_complete(ahc, cmd);
+}
+
+static void
+ahc_linux_handle_scsi_status(struct ahc_softc *ahc,
+			     struct ahc_linux_device *dev, struct scb *scb)
+{
+	/*
+	 * We don't currently trust the mid-layer to
+	 * properly deal with queue full or busy.  So,
+	 * when one occurs, we tell the mid-layer to
+	 * unconditionally requeue the command to us
+	 * so that we can retry it ourselves.  We also
+	 * implement our own throttling mechanism so
+	 * we don't clobber the device with too many
+	 * commands.
+	 */
+	switch (ahc_get_scsi_status(scb)) {
+	default:
+		break;
+	case SCSI_STATUS_QUEUE_FULL:
+	{
+		/*
+		 * By the time the core driver has returned this
+		 * command, all other commands that were queued
+		 * to us but not the device have been returned.
+		 * This ensures that dev->active is equal to
+		 * the number of commands actually queued to
+		 * the device.
+		 */
+		dev->tag_success_count = 0;
+		if (dev->active != 0) {
+			/*
+			 * Drop our opening count to the number
+			 * of commands currently outstanding.
+			 */
+			dev->openings = 0;
+/*
+			ahc_print_path(ahc, scb);
+			printf("Dropping tag count to %d\n", dev->active);
+ */
+			if (dev->active == dev->tags_on_last_queuefull) {
+
+				dev->last_queuefull_same_count++;
+				/*
+				 * If we repeatedly see a queue full
+				 * at the same queue depth, this
+				 * device has a fixed number of tag
+				 * slots.  Lock in this tag depth
+				 * so we stop seeing queue fulls from
+				 * this device.
+				 */
+				if (dev->last_queuefull_same_count
+				 == AHC_LOCK_TAGS_COUNT) {
+					dev->maxtags = dev->active;
+					ahc_print_path(ahc, scb);
+					printf("Locking max tag count at %d\n",
+					       dev->active);
+				}
+			} else {
+				dev->tags_on_last_queuefull = dev->active;
+				dev->last_queuefull_same_count = 0;
+			}
+			ahc_set_transaction_status(scb, CAM_REQUEUE_REQ);
+			ahc_set_scsi_status(scb, SCSI_STATUS_OK);
+			break;
+		}
+		/*
+		 * Drop down to a single opening, and treat this
+		 * as if the target return BUSY SCSI status.
+		 */
+		dev->openings = 1;
+		/* FALLTHROUGH */
+	}
+	case SCSI_STATUS_BUSY:
+	{
+		/*
+		 * Set a short timer to defer sending commands for
+		 * a bit since Linux will not delay in this case.
+		 */
+		if ((dev->flags & AHC_DEV_TIMER_ACTIVE) != 0) {
+			printf("%s:%c:%d: Device Timer still active during "
+			       "busy processing\n", ahc_name(ahc),
+				dev->target->channel, dev->target->target);
+			break;
+		}
+		dev->flags |= AHC_DEV_TIMER_ACTIVE;
+		dev->qfrozen++;
+		init_timer(&dev->timer);
+		dev->timer.data = (u_long)dev;
+		dev->timer.expires = jiffies + (HZ/2);
+		dev->timer.function = ahc_linux_dev_timed_unfreeze;
+		add_timer(&dev->timer);
+		break;
+	}
+	}
+}
+
+static void
+ahc_linux_filter_command(struct ahc_softc *ahc, Scsi_Cmnd *cmd, struct scb *scb)
+{
+	switch (cmd->cmnd[0]) {
+	case INQUIRY:
+	{
+		struct	ahc_devinfo devinfo;
+		struct	scsi_inquiry *inq;
+		struct	scsi_inquiry_data *sid;
+		struct	ahc_initiator_tinfo *tinfo;
+		struct	ahc_transinfo *user;
+		struct	ahc_transinfo *goal;
+		struct	ahc_transinfo *curr;
+		struct	ahc_tmode_tstate *tstate;
+		struct	ahc_syncrate *syncrate;
+		struct	ahc_linux_device *dev;
+		u_int	scsiid;
+		u_int	maxsync;
+		int	transferred_len;
+		int	minlen;
+		u_int	width;
+		u_int	period;
+		u_int	offset;
+		u_int	ppr_options;
+
+		 /*
+		  * Validate the command.  We only want to filter
+		  * standard inquiry commands, not those querying
+		  * Vital Product Data.
+		  */
+		inq = (struct scsi_inquiry *)cmd->cmnd;
+		if ((inq->byte2 & SI_EVPD) != 0
+		 || inq->page_code != 0)
+			break;
+
+		if (cmd->use_sg != 0) {
+			printf("%s: SG Inquiry response ignored\n",
+			       ahc_name(ahc));
+			break;
+		}
+		transferred_len = ahc_get_transfer_length(scb)
+				- ahc_get_residual(scb);
+		sid = (struct scsi_inquiry_data *)cmd->request_buffer;
+
+		/*
+		 * Determine if this lun actually exists.  If so,
+		 * hold on to its corresponding device structure.
+		 * If not, make sure we release the device and
+		 * don't bother processing the rest of this inquiry
+		 * command.
+		 */
+		dev = ahc_linux_get_device(ahc, cmd->channel,
+					   cmd->target, cmd->lun,
+					   /*alloc*/FALSE);
+		if (transferred_len >= 1
+		 && SID_QUAL(sid) == SID_QUAL_LU_CONNECTED) {
+
+			dev->flags &= ~AHC_DEV_UNCONFIGURED;
+		} else {
+			dev->flags |= AHC_DEV_UNCONFIGURED;
+			break;
+		}
+
+		/*
+		 * Update our notion of this device's transfer
+		 * negotiation capabilities.
+		 */
+		scsiid = BUILD_SCSIID(ahc, cmd);
+		ahc_compile_devinfo(&devinfo, SCSIID_OUR_ID(scsiid),
+				    cmd->target, cmd->lun,
+				    SCSIID_CHANNEL(ahc, scsiid),
+				    ROLE_INITIATOR);
+		tinfo = ahc_fetch_transinfo(ahc, devinfo.channel,
+					    devinfo.our_scsiid,
+					    devinfo.target, &tstate);
+		user = &tinfo->user;
+		goal = &tinfo->goal;
+		curr = &tinfo->curr;
+		width = user->width;
+		period = user->period;
+		offset = user->offset;
+		ppr_options = user->ppr_options;
+		minlen = offsetof(struct scsi_inquiry_data, version) + 1;
+		if (transferred_len >= minlen) {
+			curr->protocol_version = SID_ANSI_REV(sid);
+
+			/*
+			 * Only attempt SPI3 once we've verified that
+			 * the device claims to support SPI3 features.
+			 */
+			if (curr->protocol_version < SCSI_REV_2)
+				curr->transport_version = SID_ANSI_REV(sid);
+			else
+				curr->transport_version = SCSI_REV_2;
+		}
+
+		minlen = offsetof(struct scsi_inquiry_data, flags) + 1;
+		if (transferred_len >= minlen
+		 && (sid->additional_length + 4) >= minlen) {
+			if ((sid->flags & SID_WBus16) == 0)
+				width = MSG_EXT_WDTR_BUS_8_BIT;
+			if ((sid->flags & SID_Sync) == 0) {
+				period = 0;
+				offset = 0;
+				ppr_options = 0;
+			}
+		} else {
+			/* Keep current settings */
+			break;
+		}
+		minlen = offsetof(struct scsi_inquiry_data, spi3data) + 1;
+		/*
+		 * This is a kludge to deal with inquiry requests that
+		 * are not large enough for us to pull the spi3/4 bits.
+		 * In this case, we assume that a device that tells us
+		 * they can provide inquiry data that spans the SPI3
+		 * bits and says its SCSI3 can handle a PPR request.
+		 * If the inquiry request has sufficient buffer space to
+		 * cover SPI3 bits, we honor them regardless of reported
+		 * SCSI REV.  We also allow any device that has had its
+		 * goal ppr_options set to allow DT speeds to keep that
+		 * option if a short inquiry occurs that would fail the
+		 * normal tests outlined above.
+		 */
+		if ((sid->additional_length + 4) >= minlen) {
+			if (transferred_len >= minlen) {
+				 if ((sid->spi3data & SID_SPI_CLOCK_DT) == 0)
+					ppr_options = 0;
+			} else if ((goal->ppr_options & MSG_EXT_PPR_DT_REQ)== 0)
+				ppr_options = 0;
+
+			if (curr->protocol_version > SCSI_REV_2)
+				curr->transport_version = 3;
+		} else {
+			ppr_options = 0;
+		}
+		ahc_validate_width(ahc, /*tinfo limit*/NULL, &width,
+				   ROLE_UNKNOWN);
+		if ((ahc->features & AHC_ULTRA2) != 0)
+			maxsync = AHC_SYNCRATE_DT;
+		else if ((ahc->features & AHC_ULTRA) != 0)
+			maxsync = AHC_SYNCRATE_ULTRA;
+		else
+			maxsync = AHC_SYNCRATE_FAST;
+
+		syncrate = ahc_find_syncrate(ahc, &period,
+					     &ppr_options, maxsync);
+		ahc_validate_offset(ahc, /*tinfo limit*/NULL, syncrate,
+				    &offset, width, ROLE_UNKNOWN);
+		if (offset == 0 || period == 0) {
+			period = 0;
+			offset = 0;
+			ppr_options = 0;
+		}
+		/* Apply our filtered user settings. */
+		ahc_set_width(ahc, &devinfo, width,
+			      AHC_TRANS_GOAL, /*paused*/FALSE);
+		ahc_set_syncrate(ahc, &devinfo, syncrate, period,
+				 offset, ppr_options, AHC_TRANS_GOAL,
+				 /*paused*/FALSE);
+		break;
+	}
+	default:
+		panic("ahc_linux_filter_command: Unexpected Command type  %x\n",
+		      cmd->cmnd[0]);
+		break;
+	}
+}
+
+static void
+ahc_linux_sem_timeout(u_long arg)
+{
+	struct semaphore *sem;
+
+	sem = (struct semaphore *)arg;
+	up(sem);
+}
+
+static void
+ahc_linux_freeze_sim_queue(struct ahc_softc *ahc)
+{
+	ahc->platform_data->qfrozen++;
+	if (ahc->platform_data->qfrozen == 1)
+		scsi_block_requests(ahc->platform_data->host);
+}
+
+static void
+ahc_linux_release_sim_queue(u_long arg)
+{
+	struct ahc_softc *ahc;
+	u_long s;
+	int    unblock_reqs;
+
+	ahc = (struct ahc_softc *)arg;
+	unblock_reqs = 0;
+	ahc_lock(ahc, &s);
+	if (ahc->platform_data->qfrozen > 0)
+		ahc->platform_data->qfrozen--;
+	if (ahc->platform_data->qfrozen == 0) {
+		unblock_reqs = 1;
+	}
+	ahc_unlock(ahc, &s);
+	/*
+	 * There is still a race here.  The mid-layer
+	 * should keep its own freeze count and use
+	 * a bottom half handler to run the queues
+	 * so we can unblock with our own lock held.
+	 */
+	if (unblock_reqs) {
+		scsi_unblock_requests(ahc->platform_data->host);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
+		tasklet_schedule(&ahc->platform_data->runq_tasklet);
+#else
+		ahc_runq_tasklet((unsigned long)ahc);
+#endif
+	}
+}
+
+static void
+ahc_linux_dev_timed_unfreeze(u_long arg)
+{
+	struct ahc_linux_device *dev;
+	struct ahc_softc *ahc;
+	u_long s;
+
+	dev = (struct ahc_linux_device *)arg;
+	ahc = dev->target->ahc;
+	ahc_lock(ahc, &s);
+	dev->flags &= ~AHC_DEV_TIMER_ACTIVE;
+	if (dev->qfrozen > 0)
+		dev->qfrozen--;
+	if (dev->qfrozen == 0
+	 && (dev->flags & AHC_DEV_ON_RUN_LIST) == 0)
+		ahc_linux_run_device_queue(ahc, dev);
+	ahc_unlock(ahc, &s);
+}
+
+static int
+ahc_linux_queue_recovery_cmd(Scsi_Cmnd *cmd, scb_flag flag)
+{
+	struct ahc_softc *ahc;
+	struct ahc_cmd *acmd;
+	struct ahc_cmd *list_acmd;
+	struct ahc_linux_device *dev;
+	struct scb *pending_scb;
+	u_long s;
+	u_int  saved_scbptr;
+	u_int  active_scb_index;
+	u_int  last_phase;
+	int    retval;
+	int    paused;
+	int    wait;
+	int    disconnected;
+
+	paused = FALSE;
+	wait = FALSE;
+	ahc = *(struct ahc_softc **)cmd->host->hostdata;
+	acmd = (struct ahc_cmd *)cmd;
+
+	printf("%s:%d:%d:%d: Attempting to queue a%s message\n",
+	       ahc_name(ahc), cmd->channel, cmd->target, cmd->lun,
+	       flag == SCB_ABORT ? "n ABORT" : " TARGET RESET");
+
+	/*
+	 * It is a bug that the upper layer takes
+	 * this lock just prior to calling us.
+	 */
+	spin_unlock_irq(&io_request_lock);
+
+	ahc_lock(ahc, &s);
+
+	/*
+	 * First determine if we currently own this command.
+	 * Start by searching the device queue.  If not found
+	 * there, check the pending_scb list.  If not found
+	 * at all, and the system wanted us to just abort the
+	 * command return success.
+	 */
+	dev = ahc_linux_get_device(ahc, cmd->channel, cmd->target,
+				   cmd->lun, /*alloc*/FALSE);
+
+	if (dev == NULL) {
+		/*
+		 * No target device for this command exists,
+		 * so we must not still own the command.
+		 */
+		printf("%s:%d:%d:%d: Is not an active device\n",
+		       ahc_name(ahc), cmd->channel, cmd->target, cmd->lun);
+		retval = SUCCESS;
+		goto no_cmd;
+	}
+
+	TAILQ_FOREACH(list_acmd, &dev->busyq, acmd_links.tqe) {
+		if (list_acmd == acmd)
+			break;
+	}
+
+	if (list_acmd != NULL) {
+		printf("%s:%d:%d:%d: Command found on device queue\n",
+		       ahc_name(ahc), cmd->channel, cmd->target, cmd->lun);
+		if (flag == SCB_ABORT) {
+			TAILQ_REMOVE(&dev->busyq, list_acmd, acmd_links.tqe);
+			cmd->result = DID_ABORT << 16;
+			ahc_linux_queue_cmd_complete(ahc, cmd);
+			retval = SUCCESS;
+			goto done;
+		}
+	}
+
+	if ((dev->flags & (AHC_DEV_Q_BASIC|AHC_DEV_Q_TAGGED)) == 0
+	 && ahc_search_untagged_queues(ahc, cmd, cmd->target,
+				       cmd->channel + 'A', cmd->lun,
+				       CAM_REQ_ABORTED, SEARCH_COMPLETE) != 0) {
+		printf("%s:%d:%d:%d: Command found on untagged queue\n",
+		       ahc_name(ahc), cmd->channel, cmd->target, cmd->lun);
+		retval = SUCCESS;
+		goto done;
+	}
+
+	/*
+	 * See if we can find a matching cmd in the pending list.
+	 */
+	LIST_FOREACH(pending_scb, &ahc->pending_scbs, pending_links) {
+		if (pending_scb->io_ctx == cmd)
+			break;
+	}
+
+	if (pending_scb == NULL && flag == SCB_DEVICE_RESET) {
+
+		/* Any SCB for this device will do for a target reset */
+		LIST_FOREACH(pending_scb, &ahc->pending_scbs, pending_links) {
+		  	if (ahc_match_scb(ahc, pending_scb, cmd->target,
+					  cmd->channel + 'A', CAM_LUN_WILDCARD,
+					  SCB_LIST_NULL, ROLE_INITIATOR) == 0)
+				break;
+		}
+	}
+
+	if (pending_scb == NULL) {
+		printf("%s:%d:%d:%d: Command not found\n",
+		       ahc_name(ahc), cmd->channel, cmd->target, cmd->lun);
+		goto no_cmd;
+	}
+
+	if ((pending_scb->flags & SCB_RECOVERY_SCB) != 0) {
+		/*
+		 * We can't queue two recovery actions using the same SCB
+		 */
+		retval = FAILED;
+		goto  done;
+	}
+
+	/*
+	 * Ensure that the card doesn't do anything
+	 * behind our back and that no selections have occurred
+	 * that have not been serviced.  Also make sure that we
+	 * didn't "just" miss an interrupt that would
+	 * affect this cmd.
+	 */
+	ahc->flags |= AHC_ALL_INTERRUPTS;
+	do {
+		if (paused)
+			ahc_unpause(ahc);
+		ahc_intr(ahc);
+		ahc_pause(ahc);
+		paused = TRUE;
+		ahc_outb(ahc, SCSISEQ, ahc_inb(ahc, SCSISEQ) & ~ENSELO);
+		ahc_clear_critical_section(ahc);
+	} while ((ahc_inb(ahc, INTSTAT) & INT_PEND) != 0
+	      || (ahc_inb(ahc, SSTAT0) & (SELDO|SELINGO)));
+	ahc->flags &= ~AHC_ALL_INTERRUPTS;
+
+	ahc_dump_card_state(ahc);
+
+	if ((pending_scb->flags & SCB_ACTIVE) == 0) {
+		printf("%s:%d:%d:%d: Command already completed\n",
+		       ahc_name(ahc), cmd->channel, cmd->target, cmd->lun);
+		goto no_cmd;
+	}
+
+	disconnected = TRUE;
+	if (flag == SCB_ABORT) {
+		if (ahc_search_qinfifo(ahc, cmd->target, cmd->channel + 'A',
+				       cmd->lun, pending_scb->hscb->tag,
+				       ROLE_INITIATOR, CAM_REQ_ABORTED,
+				       SEARCH_COMPLETE) > 0) {
+			printf("%s:%d:%d:%d: Cmd aborted from QINFIFO\n",
+			       ahc_name(ahc), cmd->channel, cmd->target,
+					cmd->lun);
+			retval = SUCCESS;
+			goto done;
+		}
+	} else if (ahc_search_qinfifo(ahc, cmd->target, cmd->channel + 'A',
+				      cmd->lun, pending_scb->hscb->tag,
+				      ROLE_INITIATOR, /*status*/0,
+				      SEARCH_COUNT) > 0) {
+		disconnected = FALSE;
+	}
+
+	if (disconnected && (ahc_inb(ahc, SEQ_FLAGS) & IDENTIFY_SEEN) != 0) {
+		struct scb *bus_scb;
+
+		bus_scb = ahc_lookup_scb(ahc, ahc_inb(ahc, SCB_TAG));
+		if (bus_scb == pending_scb)
+			disconnected = FALSE;
+		else if (flag != SCB_ABORT
+		      && ahc_inb(ahc, SAVED_SCSIID) == pending_scb->hscb->scsiid
+		      && ahc_inb(ahc, SAVED_LUN) == pending_scb->hscb->lun)
+			disconnected = FALSE;
+	}
+
+	/*
+	 * At this point, pending_scb is the scb associated with the
+	 * passed in command.  That command is currently active on the
+	 * bus, is in the disconnected state, or we're hoping to find
+	 * a command for the same target active on the bus to abuse to
+	 * send a BDR.  Queue the appropriate message based on which of
+	 * these states we are in.
+	 */
+	last_phase = ahc_inb(ahc, LASTPHASE);
+	saved_scbptr = ahc_inb(ahc, SCBPTR);
+	active_scb_index = ahc_inb(ahc, SCB_TAG);
+	if (last_phase != P_BUSFREE
+	 && (pending_scb->hscb->tag == active_scb_index
+	  || (flag == SCB_DEVICE_RESET
+	   && SCSIID_TARGET(ahc, ahc_inb(ahc, SAVED_SCSIID)) == cmd->target))) {
+
+		/*
+		 * We're active on the bus, so assert ATN
+		 * and hope that the target responds.
+		 */
+		pending_scb = ahc_lookup_scb(ahc, active_scb_index);
+		pending_scb->flags |= SCB_RECOVERY_SCB|flag;
+		ahc_outb(ahc, MSG_OUT, HOST_MSG);
+		ahc_outb(ahc, SCSISIGO, last_phase|ATNO);
+		printf("%s:%d:%d:%d: Device is active, asserting ATN\n",
+		       ahc_name(ahc), cmd->channel, cmd->target, cmd->lun);
+		wait = TRUE;
+	} else if (disconnected) {
+
+		/*
+		 * Actually re-queue this SCB in an attempt
+		 * to select the device before it reconnects.
+		 * In either case (selection or reselection),
+		 * we will now issue the approprate message
+		 * to the timed-out device.
+		 *
+		 * Set the MK_MESSAGE control bit indicating
+		 * that we desire to send a message.  We
+		 * also set the disconnected flag since
+		 * in the paging case there is no guarantee
+		 * that our SCB control byte matches the
+		 * version on the card.  We don't want the
+		 * sequencer to abort the command thinking
+		 * an unsolicited reselection occurred.
+		 */
+		pending_scb->hscb->control |= MK_MESSAGE|DISCONNECTED;
+		pending_scb->flags |= SCB_RECOVERY_SCB|flag;
+
+		/*
+		 * Remove any cached copy of this SCB in the
+		 * disconnected list in preparation for the
+		 * queuing of our abort SCB.  We use the
+		 * same element in the SCB, SCB_NEXT, for
+		 * both the qinfifo and the disconnected list.
+		 */
+		ahc_search_disc_list(ahc, cmd->target, cmd->channel + 'A',
+				     cmd->lun, pending_scb->hscb->tag,
+				     /*stop_on_first*/TRUE,
+				     /*remove*/TRUE,
+				     /*save_state*/FALSE);
+
+		/*
+		 * In the non-paging case, the sequencer will
+		 * never re-reference the in-core SCB.
+		 * To make sure we are notified during
+		 * reslection, set the MK_MESSAGE flag in
+		 * the card's copy of the SCB.
+		 */
+		if ((ahc->flags & AHC_PAGESCBS) == 0) {
+			ahc_outb(ahc, SCBPTR, pending_scb->hscb->tag);
+			ahc_outb(ahc, SCB_CONTROL,
+				 ahc_inb(ahc, SCB_CONTROL)|MK_MESSAGE);
+		}
+
+		/*
+		 * Clear out any entries in the QINFIFO first
+		 * so we are the next SCB for this target
+		 * to run.
+		 */
+		ahc_search_qinfifo(ahc, cmd->target, cmd->channel + 'A',
+				   cmd->lun, SCB_LIST_NULL, ROLE_INITIATOR,
+				   CAM_REQUEUE_REQ, SEARCH_COMPLETE);
+		ahc_print_path(ahc, pending_scb);
+		printf("Queuing a recovery SCB\n");
+		ahc_qinfifo_requeue_tail(ahc, pending_scb);
+		ahc_outb(ahc, SCBPTR, saved_scbptr);
+		printf("%s:%d:%d:%d: Device is disconnected, re-queuing SCB\n",
+		       ahc_name(ahc), cmd->channel, cmd->target, cmd->lun);
+		wait = TRUE;
+	} else {
+		printf("%s:%d:%d:%d: Unable to deliver message\n",
+		       ahc_name(ahc), cmd->channel, cmd->target, cmd->lun);
+		retval = FAILED;
+		goto done;
+	}
+
+no_cmd:
+	/*
+	 * Our assumption is that if we don't have the command, no
+	 * recovery action was required, so we return success.  Again,
+	 * the semantics of the mid-layer recovery engine are not
+	 * well defined, so this may change in time.
+	 */
+	retval = SUCCESS;
+done:
+	if (paused)
+		ahc_unpause(ahc);
+	if (wait) {
+		struct timer_list timer;
+		int ret;
+
+		ahc_unlock(ahc, &s);
+		init_timer(&timer);
+		timer.data = (u_long)&ahc->platform_data->eh_sem;
+		timer.expires = jiffies + (5 * HZ);
+		timer.function = ahc_linux_sem_timeout;
+		add_timer(&timer);
+		printf("Recovery code sleeping\n");
+		down(&ahc->platform_data->eh_sem);
+		printf("Recovery code awake\n");
+        	ret = del_timer(&timer);
+		if (ret == 0) {
+			printf("Timer Expired\n");
+			retval = FAILED;
+		}
+		ahc_lock(ahc, &s);
+	}
+	acmd = TAILQ_FIRST(&ahc->platform_data->completeq);
+	TAILQ_INIT(&ahc->platform_data->completeq);
+	ahc_unlock(ahc, &s);
+	if (acmd != NULL)
+		ahc_linux_run_complete_queue(ahc, acmd);
+	ahc_runq_tasklet((unsigned long)ahc);
+	spin_lock_irq(&io_request_lock);
+	return (retval);
+}
+
+/*
+ * Abort the current SCSI command(s).
+ */
+int
+ahc_linux_abort(Scsi_Cmnd *cmd)
+{
+	int error;
+
+	error = ahc_linux_queue_recovery_cmd(cmd, SCB_ABORT);
+	if (error != 0)
+		printf("aic7xxx_abort returns 0x%x\n", error);
+	return (error);
+}
+
+/*
+ * Attempt to send a target reset message to the device that timed out.
+ */
+int
+ahc_linux_dev_reset(Scsi_Cmnd *cmd)
+{
+	int error;
+
+	error = ahc_linux_queue_recovery_cmd(cmd, SCB_DEVICE_RESET);
+	if (error != 0)
+		printf("aic7xxx_dev_reset returns 0x%x\n", error);
+	return (error);
+}
+
+/*
+ * Reset the SCSI bus.
+ */
+int
+ahc_linux_bus_reset(Scsi_Cmnd *cmd)
+{
+	struct ahc_softc *ahc;
+	struct ahc_cmd *acmd;
+	u_long s;
+	int    found;
+
+	/*
+	 * It is a bug that the upper layer takes
+	 * this lock just prior to calling us.
+	 */
+	spin_unlock_irq(&io_request_lock);
+
+	ahc = *(struct ahc_softc **)cmd->host->hostdata;
+	ahc_lock(ahc, &s);
+	found = ahc_reset_channel(ahc, cmd->channel + 'A',
+				  /*initiate reset*/TRUE);
+	acmd = TAILQ_FIRST(&ahc->platform_data->completeq);
+	TAILQ_INIT(&ahc->platform_data->completeq);
+	ahc_unlock(ahc, &s);
+	if (bootverbose)
+		printf("%s: SCSI bus reset delivered. "
+		       "%d SCBs aborted.\n", ahc_name(ahc), found);
+
+	if (acmd != NULL)
+		ahc_linux_run_complete_queue(ahc, acmd);
+
+	spin_lock_irq(&io_request_lock);
+	return SUCCESS;
+}
+
+/*
+ * Return the disk geometry for the given SCSI device.
+ */
+int
+ahc_linux_biosparam(Disk *disk, kdev_t dev, int geom[])
+{
+	int	heads;
+	int	sectors;
+	int	cylinders;
+	int	ret;
+	int	extended;
+	struct	ahc_softc *ahc;
+	struct	buffer_head *bh;
+
+	ahc = *((struct ahc_softc **)disk->device->host->hostdata);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,17)
+	bh = bread(MKDEV(MAJOR(dev), MINOR(dev) & ~0xf), 0, block_size(dev));
+#else
+	bh = bread(MKDEV(MAJOR(dev), MINOR(dev) & ~0xf), 0, 1024);
+#endif
+
+	if (bh) {
+		ret = scsi_partsize(bh, disk->capacity,
+				    &geom[2], &geom[0], &geom[1]);
+		brelse(bh);
+		if (ret != -1)
+			return (ret);
+	}
+	heads = 64;
+	sectors = 32;
+	cylinders = disk->capacity / (heads * sectors);
+
+	if (aic7xxx_extended != 0)
+		extended = 1;
+	else if (disk->device->channel == 0)
+		extended = (ahc->flags & AHC_EXTENDED_TRANS_A) != 0;
+	else
+		extended = (ahc->flags & AHC_EXTENDED_TRANS_B) != 0;
+	if (extended && cylinders >= 1024) {
+		heads = 255;
+		sectors = 63;
+		cylinders = disk->capacity / (heads * sectors);
+	}
+	geom[0] = heads;
+	geom[1] = sectors;
+	geom[2] = cylinders;
+	return (0);
+}
+
+/*
+ * Free the passed in Scsi_Host memory structures prior to unloading the
+ * module.
+ */
+int
+ahc_linux_release(struct Scsi_Host * host)
+{
+	struct ahc_softc *ahc;
+	u_long l;
+
+	ahc_list_lock(&l);
+	if (host != NULL) {
+
+		/*
+		 * We should be able to just perform
+		 * the free directly, but check our
+		 * list for extra sanity.
+		 */
+		ahc = ahc_find_softc(*(struct ahc_softc **)host->hostdata);
+		if (ahc != NULL) {
+			u_long s;
+
+			ahc_lock(ahc, &s);
+			ahc_intr_enable(ahc, FALSE);
+			ahc_unlock(ahc, &s);
+			ahc_free(ahc);
+		}
+	}
+	ahc_list_unlock(&l);
+	return (0);
+}
+
+void
+ahc_platform_dump_card_state(struct ahc_softc *ahc)
+{
+	struct ahc_linux_device *dev;
+	int channel;
+	int maxchannel;
+	int target;
+	int maxtarget;
+	int lun;
+	int i;
+
+	maxchannel = (ahc->features & AHC_TWIN) ? 1 : 0;
+	maxtarget = (ahc->features & AHC_WIDE) ? 15 : 7;
+	for (channel = 0; channel <= maxchannel; channel++) {
+
+		for (target = 0; target <=maxtarget; target++) {
+
+			for (lun = 0; lun < AHC_NUM_LUNS; lun++) {
+				struct ahc_cmd *acmd;
+
+				dev = ahc_linux_get_device(ahc, channel, target,
+							   lun, /*alloc*/FALSE);
+				if (dev == NULL)
+					continue;
+
+				printf("DevQ(%d:%d:%d): ",
+				       channel, target, lun);
+				i = 0;
+				TAILQ_FOREACH(acmd, &dev->busyq,
+					      acmd_links.tqe) {
+					if (i++ > AHC_SCB_MAX)
+						break;
+				}
+				printf("%d waiting\n", i);
+			}
+		}
+	}
+}
+
+#if defined(MODULE) || LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
+static Scsi_Host_Template driver_template = AIC7XXX;
+Scsi_Host_Template *aic7xxx_driver_template = &driver_template;
+#include "../scsi_module.c"
+#endif

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)