Linux-2.6.12-rc2v2.6.12-rc2

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

Let it rip!

1 files changed, 2077 insertions, 0 deletions

diff --git a/drivers/scsi/wd33c93.c b/drivers/scsi/wd33c93.c
new file mode 100644
index 00000000000..5754445fb36
--- /dev/null
+++ b/drivers/scsi/wd33c93.c
@@ -0,0 +1,2077 @@
+/*
+ * Copyright (c) 1996 John Shifflett, GeoLog Consulting
+ *    john@geolog.com
+ *    jshiffle@netcom.com
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, 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.
+ */
+
+/*
+ * Drew Eckhardt's excellent 'Generic NCR5380' sources from Linux-PC
+ * provided much of the inspiration and some of the code for this
+ * driver. Everything I know about Amiga DMA was gleaned from careful
+ * reading of Hamish Mcdonald's original wd33c93 driver; in fact, I
+ * borrowed shamelessly from all over that source. Thanks Hamish!
+ *
+ * _This_ driver is (I feel) an improvement over the old one in
+ * several respects:
+ *
+ *    -  Target Disconnection/Reconnection  is now supported. Any
+ *          system with more than one device active on the SCSI bus
+ *          will benefit from this. The driver defaults to what I
+ *          call 'adaptive disconnect' - meaning that each command
+ *          is evaluated individually as to whether or not it should
+ *          be run with the option to disconnect/reselect (if the
+ *          device chooses), or as a "SCSI-bus-hog".
+ *
+ *    -  Synchronous data transfers are now supported. Because of
+ *          a few devices that choke after telling the driver that
+ *          they can do sync transfers, we don't automatically use
+ *          this faster protocol - it can be enabled via the command-
+ *          line on a device-by-device basis.
+ *
+ *    -  Runtime operating parameters can now be specified through
+ *       the 'amiboot' or the 'insmod' command line. For amiboot do:
+ *          "amiboot [usual stuff] wd33c93=blah,blah,blah"
+ *       The defaults should be good for most people. See the comment
+ *       for 'setup_strings' below for more details.
+ *
+ *    -  The old driver relied exclusively on what the Western Digital
+ *          docs call "Combination Level 2 Commands", which are a great
+ *          idea in that the CPU is relieved of a lot of interrupt
+ *          overhead. However, by accepting a certain (user-settable)
+ *          amount of additional interrupts, this driver achieves
+ *          better control over the SCSI bus, and data transfers are
+ *          almost as fast while being much easier to define, track,
+ *          and debug.
+ *
+ *
+ * TODO:
+ *       more speed. linked commands.
+ *
+ *
+ * People with bug reports, wish-lists, complaints, comments,
+ * or improvements are asked to pah-leeez email me (John Shifflett)
+ * at john@geolog.com or jshiffle@netcom.com! I'm anxious to get
+ * this thing into as good a shape as possible, and I'm positive
+ * there are lots of lurking bugs and "Stupid Places".
+ *
+ * Updates:
+ *
+ * Added support for pre -A chips, which don't have advanced features
+ * and will generate CSR_RESEL rather than CSR_RESEL_AM.
+ *	Richard Hirst <richard@sleepie.demon.co.uk>  August 2000
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/delay.h>
+#include <linux/version.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <asm/irq.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+
+#include "wd33c93.h"
+
+
+#define WD33C93_VERSION    "1.26"
+#define WD33C93_DATE       "22/Feb/2003"
+
+MODULE_AUTHOR("John Shifflett");
+MODULE_DESCRIPTION("Generic WD33C93 SCSI driver");
+MODULE_LICENSE("GPL");
+
+/*
+ * 'setup_strings' is a single string used to pass operating parameters and
+ * settings from the kernel/module command-line to the driver. 'setup_args[]'
+ * is an array of strings that define the compile-time default values for
+ * these settings. If Linux boots with an amiboot or insmod command-line,
+ * those settings are combined with 'setup_args[]'. Note that amiboot
+ * command-lines are prefixed with "wd33c93=" while insmod uses a
+ * "setup_strings=" prefix. The driver recognizes the following keywords
+ * (lower case required) and arguments:
+ *
+ * -  nosync:bitmask -bitmask is a byte where the 1st 7 bits correspond with
+ *                    the 7 possible SCSI devices. Set a bit to negotiate for
+ *                    asynchronous transfers on that device. To maintain
+ *                    backwards compatibility, a command-line such as
+ *                    "wd33c93=255" will be automatically translated to
+ *                    "wd33c93=nosync:0xff".
+ * -  nodma:x        -x = 1 to disable DMA, x = 0 to enable it. Argument is
+ *                    optional - if not present, same as "nodma:1".
+ * -  period:ns      -ns is the minimum # of nanoseconds in a SCSI data transfer
+ *                    period. Default is 500; acceptable values are 250 - 1000.
+ * -  disconnect:x   -x = 0 to never allow disconnects, 2 to always allow them.
+ *                    x = 1 does 'adaptive' disconnects, which is the default
+ *                    and generally the best choice.
+ * -  debug:x        -If 'DEBUGGING_ON' is defined, x is a bit mask that causes
+ *                    various types of debug output to printed - see the DB_xxx
+ *                    defines in wd33c93.h
+ * -  clock:x        -x = clock input in MHz for WD33c93 chip. Normal values
+ *                    would be from 8 through 20. Default is 8.
+ * -  next           -No argument. Used to separate blocks of keywords when
+ *                    there's more than one host adapter in the system.
+ *
+ * Syntax Notes:
+ * -  Numeric arguments can be decimal or the '0x' form of hex notation. There
+ *    _must_ be a colon between a keyword and its numeric argument, with no
+ *    spaces.
+ * -  Keywords are separated by commas, no spaces, in the standard kernel
+ *    command-line manner.
+ * -  A keyword in the 'nth' comma-separated command-line member will overwrite
+ *    the 'nth' element of setup_args[]. A blank command-line member (in
+ *    other words, a comma with no preceding keyword) will _not_ overwrite
+ *    the corresponding setup_args[] element.
+ * -  If a keyword is used more than once, the first one applies to the first
+ *    SCSI host found, the second to the second card, etc, unless the 'next'
+ *    keyword is used to change the order.
+ *
+ * Some amiboot examples (for insmod, use 'setup_strings' instead of 'wd33c93'):
+ * -  wd33c93=nosync:255
+ * -  wd33c93=nodma
+ * -  wd33c93=nodma:1
+ * -  wd33c93=disconnect:2,nosync:0x08,period:250
+ * -  wd33c93=debug:0x1c
+ */
+
+/* Normally, no defaults are specified */
+static char *setup_args[] = { "", "", "", "", "", "", "", "", "" };
+
+static char *setup_strings;
+module_param(setup_strings, charp, 0);
+
+static void wd33c93_execute(struct Scsi_Host *instance);
+
+#ifdef CONFIG_WD33C93_PIO
+static inline uchar
+read_wd33c93(const wd33c93_regs regs, uchar reg_num)
+{
+	uchar data;
+
+	outb(reg_num, regs.SASR);
+	data = inb(regs.SCMD);
+	return data;
+}
+
+static inline unsigned long
+read_wd33c93_count(const wd33c93_regs regs)
+{
+	unsigned long value;
+
+	outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
+	value = inb(regs.SCMD) << 16;
+	value |= inb(regs.SCMD) << 8;
+	value |= inb(regs.SCMD);
+	return value;
+}
+
+static inline uchar
+read_aux_stat(const wd33c93_regs regs)
+{
+	return inb(regs.SASR);
+}
+
+static inline void
+write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
+{
+      outb(reg_num, regs.SASR);
+      outb(value, regs.SCMD);
+}
+
+static inline void
+write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
+{
+	outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
+	outb((value >> 16) & 0xff, regs.SCMD);
+	outb((value >> 8) & 0xff, regs.SCMD);
+	outb( value & 0xff, regs.SCMD);
+}
+
+#define write_wd33c93_cmd(regs, cmd) \
+	write_wd33c93((regs), WD_COMMAND, (cmd))
+
+static inline void
+write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
+{
+	int i;
+
+	outb(WD_CDB_1, regs.SASR);
+	for (i=0; i<len; i++)
+		outb(cmnd[i], regs.SCMD);
+}
+
+#else /* CONFIG_WD33C93_PIO */
+static inline uchar
+read_wd33c93(const wd33c93_regs regs, uchar reg_num)
+{
+	*regs.SASR = reg_num;
+	mb();
+	return (*regs.SCMD);
+}
+
+static unsigned long
+read_wd33c93_count(const wd33c93_regs regs)
+{
+	unsigned long value;
+
+	*regs.SASR = WD_TRANSFER_COUNT_MSB;
+	mb();
+	value = *regs.SCMD << 16;
+	value |= *regs.SCMD << 8;
+	value |= *regs.SCMD;
+	mb();
+	return value;
+}
+
+static inline uchar
+read_aux_stat(const wd33c93_regs regs)
+{
+	return *regs.SASR;
+}
+
+static inline void
+write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
+{
+	*regs.SASR = reg_num;
+	mb();
+	*regs.SCMD = value;
+	mb();
+}
+
+static void
+write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
+{
+	*regs.SASR = WD_TRANSFER_COUNT_MSB;
+	mb();
+	*regs.SCMD = value >> 16;
+	*regs.SCMD = value >> 8;
+	*regs.SCMD = value;
+	mb();
+}
+
+static inline void
+write_wd33c93_cmd(const wd33c93_regs regs, uchar cmd)
+{
+	*regs.SASR = WD_COMMAND;
+	mb();
+	*regs.SCMD = cmd;
+	mb();
+}
+
+static inline void
+write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
+{
+	int i;
+
+	*regs.SASR = WD_CDB_1;
+	for (i = 0; i < len; i++)
+		*regs.SCMD = cmnd[i];
+}
+#endif /* CONFIG_WD33C93_PIO */
+
+static inline uchar
+read_1_byte(const wd33c93_regs regs)
+{
+	uchar asr;
+	uchar x = 0;
+
+	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
+	write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO | 0x80);
+	do {
+		asr = read_aux_stat(regs);
+		if (asr & ASR_DBR)
+			x = read_wd33c93(regs, WD_DATA);
+	} while (!(asr & ASR_INT));
+	return x;
+}
+
+static struct sx_period sx_table[] = {
+	{1, 0x20},
+	{252, 0x20},
+	{376, 0x30},
+	{500, 0x40},
+	{624, 0x50},
+	{752, 0x60},
+	{876, 0x70},
+	{1000, 0x00},
+	{0, 0}
+};
+
+static int
+round_period(unsigned int period)
+{
+	int x;
+
+	for (x = 1; sx_table[x].period_ns; x++) {
+		if ((period <= sx_table[x - 0].period_ns) &&
+		    (period > sx_table[x - 1].period_ns)) {
+			return x;
+		}
+	}
+	return 7;
+}
+
+static uchar
+calc_sync_xfer(unsigned int period, unsigned int offset)
+{
+	uchar result;
+
+	period *= 4;		/* convert SDTR code to ns */
+	result = sx_table[round_period(period)].reg_value;
+	result |= (offset < OPTIMUM_SX_OFF) ? offset : OPTIMUM_SX_OFF;
+	return result;
+}
+
+int
+wd33c93_queuecommand(struct scsi_cmnd *cmd,
+		void (*done)(struct scsi_cmnd *))
+{
+	struct WD33C93_hostdata *hostdata;
+	struct scsi_cmnd *tmp;
+
+	hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;
+
+	DB(DB_QUEUE_COMMAND,
+	   printk("Q-%d-%02x-%ld( ", cmd->device->id, cmd->cmnd[0], cmd->pid))
+
+/* Set up a few fields in the scsi_cmnd structure for our own use:
+ *  - host_scribble is the pointer to the next cmd in the input queue
+ *  - scsi_done points to the routine we call when a cmd is finished
+ *  - result is what you'd expect
+ */
+	cmd->host_scribble = NULL;
+	cmd->scsi_done = done;
+	cmd->result = 0;
+
+/* We use the Scsi_Pointer structure that's included with each command
+ * as a scratchpad (as it's intended to be used!). The handy thing about
+ * the SCp.xxx fields is that they're always associated with a given
+ * cmd, and are preserved across disconnect-reselect. This means we
+ * can pretty much ignore SAVE_POINTERS and RESTORE_POINTERS messages
+ * if we keep all the critical pointers and counters in SCp:
+ *  - SCp.ptr is the pointer into the RAM buffer
+ *  - SCp.this_residual is the size of that buffer
+ *  - SCp.buffer points to the current scatter-gather buffer
+ *  - SCp.buffers_residual tells us how many S.G. buffers there are
+ *  - SCp.have_data_in is not used
+ *  - SCp.sent_command is not used
+ *  - SCp.phase records this command's SRCID_ER bit setting
+ */
+
+	if (cmd->use_sg) {
+		cmd->SCp.buffer = (struct scatterlist *) cmd->buffer;
+		cmd->SCp.buffers_residual = cmd->use_sg - 1;
+		cmd->SCp.ptr = page_address(cmd->SCp.buffer->page) +
+		    cmd->SCp.buffer->offset;
+		cmd->SCp.this_residual = cmd->SCp.buffer->length;
+	} else {
+		cmd->SCp.buffer = NULL;
+		cmd->SCp.buffers_residual = 0;
+		cmd->SCp.ptr = (char *) cmd->request_buffer;
+		cmd->SCp.this_residual = cmd->request_bufflen;
+	}
+
+/* WD docs state that at the conclusion of a "LEVEL2" command, the
+ * status byte can be retrieved from the LUN register. Apparently,
+ * this is the case only for *uninterrupted* LEVEL2 commands! If
+ * there are any unexpected phases entered, even if they are 100%
+ * legal (different devices may choose to do things differently),
+ * the LEVEL2 command sequence is exited. This often occurs prior
+ * to receiving the status byte, in which case the driver does a
+ * status phase interrupt and gets the status byte on its own.
+ * While such a command can then be "resumed" (ie restarted to
+ * finish up as a LEVEL2 command), the LUN register will NOT be
+ * a valid status byte at the command's conclusion, and we must
+ * use the byte obtained during the earlier interrupt. Here, we
+ * preset SCp.Status to an illegal value (0xff) so that when
+ * this command finally completes, we can tell where the actual
+ * status byte is stored.
+ */
+
+	cmd->SCp.Status = ILLEGAL_STATUS_BYTE;
+
+	/*
+	 * Add the cmd to the end of 'input_Q'. Note that REQUEST SENSE
+	 * commands are added to the head of the queue so that the desired
+	 * sense data is not lost before REQUEST_SENSE executes.
+	 */
+
+	spin_lock_irq(&hostdata->lock);
+
+	if (!(hostdata->input_Q) || (cmd->cmnd[0] == REQUEST_SENSE)) {
+		cmd->host_scribble = (uchar *) hostdata->input_Q;
+		hostdata->input_Q = cmd;
+	} else {		/* find the end of the queue */
+		for (tmp = (struct scsi_cmnd *) hostdata->input_Q;
+		     tmp->host_scribble;
+		     tmp = (struct scsi_cmnd *) tmp->host_scribble) ;
+		tmp->host_scribble = (uchar *) cmd;
+	}
+
+/* We know that there's at least one command in 'input_Q' now.
+ * Go see if any of them are runnable!
+ */
+
+	wd33c93_execute(cmd->device->host);
+
+	DB(DB_QUEUE_COMMAND, printk(")Q-%ld ", cmd->pid))
+
+	spin_unlock_irq(&hostdata->lock);
+	return 0;
+}
+
+/*
+ * This routine attempts to start a scsi command. If the host_card is
+ * already connected, we give up immediately. Otherwise, look through
+ * the input_Q, using the first command we find that's intended
+ * for a currently non-busy target/lun.
+ *
+ * wd33c93_execute() is always called with interrupts disabled or from
+ * the wd33c93_intr itself, which means that a wd33c93 interrupt
+ * cannot occur while we are in here.
+ */
+static void
+wd33c93_execute(struct Scsi_Host *instance)
+{
+	struct WD33C93_hostdata *hostdata =
+	    (struct WD33C93_hostdata *) instance->hostdata;
+	const wd33c93_regs regs = hostdata->regs;
+	struct scsi_cmnd *cmd, *prev;
+
+	DB(DB_EXECUTE, printk("EX("))
+	if (hostdata->selecting || hostdata->connected) {
+		DB(DB_EXECUTE, printk(")EX-0 "))
+		return;
+	}
+
+	/*
+	 * Search through the input_Q for a command destined
+	 * for an idle target/lun.
+	 */
+
+	cmd = (struct scsi_cmnd *) hostdata->input_Q;
+	prev = 0;
+	while (cmd) {
+		if (!(hostdata->busy[cmd->device->id] & (1 << cmd->device->lun)))
+			break;
+		prev = cmd;
+		cmd = (struct scsi_cmnd *) cmd->host_scribble;
+	}
+
+	/* quit if queue empty or all possible targets are busy */
+
+	if (!cmd) {
+		DB(DB_EXECUTE, printk(")EX-1 "))
+		return;
+	}
+
+	/*  remove command from queue */
+
+	if (prev)
+		prev->host_scribble = cmd->host_scribble;
+	else
+		hostdata->input_Q = (struct scsi_cmnd *) cmd->host_scribble;
+
+#ifdef PROC_STATISTICS
+	hostdata->cmd_cnt[cmd->device->id]++;
+#endif
+
+	/*
+	 * Start the selection process
+	 */
+
+	if (cmd->sc_data_direction == DMA_TO_DEVICE)
+		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
+	else
+		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id | DSTID_DPD);
+
+/* Now we need to figure out whether or not this command is a good
+ * candidate for disconnect/reselect. We guess to the best of our
+ * ability, based on a set of hierarchical rules. When several
+ * devices are operating simultaneously, disconnects are usually
+ * an advantage. In a single device system, or if only 1 device
+ * is being accessed, transfers usually go faster if disconnects
+ * are not allowed:
+ *
+ * + Commands should NEVER disconnect if hostdata->disconnect =
+ *   DIS_NEVER (this holds for tape drives also), and ALWAYS
+ *   disconnect if hostdata->disconnect = DIS_ALWAYS.
+ * + Tape drive commands should always be allowed to disconnect.
+ * + Disconnect should be allowed if disconnected_Q isn't empty.
+ * + Commands should NOT disconnect if input_Q is empty.
+ * + Disconnect should be allowed if there are commands in input_Q
+ *   for a different target/lun. In this case, the other commands
+ *   should be made disconnect-able, if not already.
+ *
+ * I know, I know - this code would flunk me out of any
+ * "C Programming 101" class ever offered. But it's easy
+ * to change around and experiment with for now.
+ */
+
+	cmd->SCp.phase = 0;	/* assume no disconnect */
+	if (hostdata->disconnect == DIS_NEVER)
+		goto no;
+	if (hostdata->disconnect == DIS_ALWAYS)
+		goto yes;
+	if (cmd->device->type == 1)	/* tape drive? */
+		goto yes;
+	if (hostdata->disconnected_Q)	/* other commands disconnected? */
+		goto yes;
+	if (!(hostdata->input_Q))	/* input_Q empty? */
+		goto no;
+	for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
+	     prev = (struct scsi_cmnd *) prev->host_scribble) {
+		if ((prev->device->id != cmd->device->id) ||
+		    (prev->device->lun != cmd->device->lun)) {
+			for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
+			     prev = (struct scsi_cmnd *) prev->host_scribble)
+				prev->SCp.phase = 1;
+			goto yes;
+		}
+	}
+
+	goto no;
+
+ yes:
+	cmd->SCp.phase = 1;
+
+#ifdef PROC_STATISTICS
+	hostdata->disc_allowed_cnt[cmd->device->id]++;
+#endif
+
+ no:
+
+	write_wd33c93(regs, WD_SOURCE_ID, ((cmd->SCp.phase) ? SRCID_ER : 0));
+
+	write_wd33c93(regs, WD_TARGET_LUN, cmd->device->lun);
+	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
+		      hostdata->sync_xfer[cmd->device->id]);
+	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
+
+	if ((hostdata->level2 == L2_NONE) ||
+	    (hostdata->sync_stat[cmd->device->id] == SS_UNSET)) {
+
+		/*
+		 * Do a 'Select-With-ATN' command. This will end with
+		 * one of the following interrupts:
+		 *    CSR_RESEL_AM:  failure - can try again later.
+		 *    CSR_TIMEOUT:   failure - give up.
+		 *    CSR_SELECT:    success - proceed.
+		 */
+
+		hostdata->selecting = cmd;
+
+/* Every target has its own synchronous transfer setting, kept in the
+ * sync_xfer array, and a corresponding status byte in sync_stat[].
+ * Each target's sync_stat[] entry is initialized to SX_UNSET, and its
+ * sync_xfer[] entry is initialized to the default/safe value. SS_UNSET
+ * means that the parameters are undetermined as yet, and that we
+ * need to send an SDTR message to this device after selection is
+ * complete: We set SS_FIRST to tell the interrupt routine to do so.
+ * If we've been asked not to try synchronous transfers on this
+ * target (and _all_ luns within it), we'll still send the SDTR message
+ * later, but at that time we'll negotiate for async by specifying a
+ * sync fifo depth of 0.
+ */
+		if (hostdata->sync_stat[cmd->device->id] == SS_UNSET)
+			hostdata->sync_stat[cmd->device->id] = SS_FIRST;
+		hostdata->state = S_SELECTING;
+		write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
+		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN);
+	} else {
+
+		/*
+		 * Do a 'Select-With-ATN-Xfer' command. This will end with
+		 * one of the following interrupts:
+		 *    CSR_RESEL_AM:  failure - can try again later.
+		 *    CSR_TIMEOUT:   failure - give up.
+		 *    anything else: success - proceed.
+		 */
+
+		hostdata->connected = cmd;
+		write_wd33c93(regs, WD_COMMAND_PHASE, 0);
+
+		/* copy command_descriptor_block into WD chip
+		 * (take advantage of auto-incrementing)
+		 */
+
+		write_wd33c93_cdb(regs, cmd->cmd_len, cmd->cmnd);
+
+		/* The wd33c93 only knows about Group 0, 1, and 5 commands when
+		 * it's doing a 'select-and-transfer'. To be safe, we write the
+		 * size of the CDB into the OWN_ID register for every case. This
+		 * way there won't be problems with vendor-unique, audio, etc.
+		 */
+
+		write_wd33c93(regs, WD_OWN_ID, cmd->cmd_len);
+
+		/* When doing a non-disconnect command with DMA, we can save
+		 * ourselves a DATA phase interrupt later by setting everything
+		 * up ahead of time.
+		 */
+
+		if ((cmd->SCp.phase == 0) && (hostdata->no_dma == 0)) {
+			if (hostdata->dma_setup(cmd,
+			    (cmd->sc_data_direction == DMA_TO_DEVICE) ?
+			     DATA_OUT_DIR : DATA_IN_DIR))
+				write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
+			else {
+				write_wd33c93_count(regs,
+						    cmd->SCp.this_residual);
+				write_wd33c93(regs, WD_CONTROL,
+					      CTRL_IDI | CTRL_EDI | CTRL_DMA);
+				hostdata->dma = D_DMA_RUNNING;
+			}
+		} else
+			write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
+
+		hostdata->state = S_RUNNING_LEVEL2;
+		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
+	}
+
+	/*
+	 * Since the SCSI bus can handle only 1 connection at a time,
+	 * we get out of here now. If the selection fails, or when
+	 * the command disconnects, we'll come back to this routine
+	 * to search the input_Q again...
+	 */
+
+	DB(DB_EXECUTE,
+	   printk("%s%ld)EX-2 ", (cmd->SCp.phase) ? "d:" : "", cmd->pid))
+}
+
+static void
+transfer_pio(const wd33c93_regs regs, uchar * buf, int cnt,
+	     int data_in_dir, struct WD33C93_hostdata *hostdata)
+{
+	uchar asr;
+
+	DB(DB_TRANSFER,
+	   printk("(%p,%d,%s:", buf, cnt, data_in_dir ? "in" : "out"))
+
+	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
+	write_wd33c93_count(regs, cnt);
+	write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
+	if (data_in_dir) {
+		do {
+			asr = read_aux_stat(regs);
+			if (asr & ASR_DBR)
+				*buf++ = read_wd33c93(regs, WD_DATA);
+		} while (!(asr & ASR_INT));
+	} else {
+		do {
+			asr = read_aux_stat(regs);
+			if (asr & ASR_DBR)
+				write_wd33c93(regs, WD_DATA, *buf++);
+		} while (!(asr & ASR_INT));
+	}
+
+	/* Note: we are returning with the interrupt UN-cleared.
+	 * Since (presumably) an entire I/O operation has
+	 * completed, the bus phase is probably different, and
+	 * the interrupt routine will discover this when it
+	 * responds to the uncleared int.
+	 */
+
+}
+
+static void
+transfer_bytes(const wd33c93_regs regs, struct scsi_cmnd *cmd,
+		int data_in_dir)
+{
+	struct WD33C93_hostdata *hostdata;
+	unsigned long length;
+
+	hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;
+
+/* Normally, you'd expect 'this_residual' to be non-zero here.
+ * In a series of scatter-gather transfers, however, this
+ * routine will usually be called with 'this_residual' equal
+ * to 0 and 'buffers_residual' non-zero. This means that a
+ * previous transfer completed, clearing 'this_residual', and
+ * now we need to setup the next scatter-gather buffer as the
+ * source or destination for THIS transfer.
+ */
+	if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
+		++cmd->SCp.buffer;
+		--cmd->SCp.buffers_residual;
+		cmd->SCp.this_residual = cmd->SCp.buffer->length;
+		cmd->SCp.ptr = page_address(cmd->SCp.buffer->page) +
+		    cmd->SCp.buffer->offset;
+	}
+
+	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
+		      hostdata->sync_xfer[cmd->device->id]);
+
+/* 'hostdata->no_dma' is TRUE if we don't even want to try DMA.
+ * Update 'this_residual' and 'ptr' after 'transfer_pio()' returns.
+ */
+
+	if (hostdata->no_dma || hostdata->dma_setup(cmd, data_in_dir)) {
+#ifdef PROC_STATISTICS
+		hostdata->pio_cnt++;
+#endif
+		transfer_pio(regs, (uchar *) cmd->SCp.ptr,
+			     cmd->SCp.this_residual, data_in_dir, hostdata);
+		length = cmd->SCp.this_residual;
+		cmd->SCp.this_residual = read_wd33c93_count(regs);
+		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
+	}
+
+/* We are able to do DMA (in fact, the Amiga hardware is
+ * already going!), so start up the wd33c93 in DMA mode.
+ * We set 'hostdata->dma' = D_DMA_RUNNING so that when the
+ * transfer completes and causes an interrupt, we're
+ * reminded to tell the Amiga to shut down its end. We'll
+ * postpone the updating of 'this_residual' and 'ptr'
+ * until then.
+ */
+
+	else {
+#ifdef PROC_STATISTICS
+		hostdata->dma_cnt++;
+#endif
+		write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_DMA);
+		write_wd33c93_count(regs, cmd->SCp.this_residual);
+
+		if ((hostdata->level2 >= L2_DATA) ||
+		    (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) {
+			write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
+			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
+			hostdata->state = S_RUNNING_LEVEL2;
+		} else
+			write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
+
+		hostdata->dma = D_DMA_RUNNING;
+	}
+}
+
+void
+wd33c93_intr(struct Scsi_Host *instance)
+{
+	struct WD33C93_hostdata *hostdata =
+	    (struct WD33C93_hostdata *) instance->hostdata;
+	const wd33c93_regs regs = hostdata->regs;
+	struct scsi_cmnd *patch, *cmd;
+	uchar asr, sr, phs, id, lun, *ucp, msg;
+	unsigned long length, flags;
+
+	asr = read_aux_stat(regs);
+	if (!(asr & ASR_INT) || (asr & ASR_BSY))
+		return;
+
+	spin_lock_irqsave(&hostdata->lock, flags);
+
+#ifdef PROC_STATISTICS
+	hostdata->int_cnt++;
+#endif
+
+	cmd = (struct scsi_cmnd *) hostdata->connected;	/* assume we're connected */
+	sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear the interrupt */
+	phs = read_wd33c93(regs, WD_COMMAND_PHASE);
+
+	DB(DB_INTR, printk("{%02x:%02x-", asr, sr))
+
+/* After starting a DMA transfer, the next interrupt
+ * is guaranteed to be in response to completion of
+ * the transfer. Since the Amiga DMA hardware runs in
+ * in an open-ended fashion, it needs to be told when
+ * to stop; do that here if D_DMA_RUNNING is true.
+ * Also, we have to update 'this_residual' and 'ptr'
+ * based on the contents of the TRANSFER_COUNT register,
+ * in case the device decided to do an intermediate
+ * disconnect (a device may do this if it has to do a
+ * seek, or just to be nice and let other devices have
+ * some bus time during long transfers). After doing
+ * whatever is needed, we go on and service the WD3393
+ * interrupt normally.
+ */
+	    if (hostdata->dma == D_DMA_RUNNING) {
+		DB(DB_TRANSFER,
+		   printk("[%p/%d:", cmd->SCp.ptr, cmd->SCp.this_residual))
+		    hostdata->dma_stop(cmd->device->host, cmd, 1);
+		hostdata->dma = D_DMA_OFF;
+		length = cmd->SCp.this_residual;
+		cmd->SCp.this_residual = read_wd33c93_count(regs);
+		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
+		DB(DB_TRANSFER,
+		   printk("%p/%d]", cmd->SCp.ptr, cmd->SCp.this_residual))
+	}
+
+/* Respond to the specific WD3393 interrupt - there are quite a few! */
+	switch (sr) {
+	case CSR_TIMEOUT:
+		DB(DB_INTR, printk("TIMEOUT"))
+
+		    if (hostdata->state == S_RUNNING_LEVEL2)
+			hostdata->connected = NULL;
+		else {
+			cmd = (struct scsi_cmnd *) hostdata->selecting;	/* get a valid cmd */
+			hostdata->selecting = NULL;
+		}
+
+		cmd->result = DID_NO_CONNECT << 16;
+		hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
+		hostdata->state = S_UNCONNECTED;
+		cmd->scsi_done(cmd);
+
+		/* From esp.c:
+		 * There is a window of time within the scsi_done() path
+		 * of execution where interrupts are turned back on full
+		 * blast and left that way.  During that time we could
+		 * reconnect to a disconnected command, then we'd bomb
+		 * out below.  We could also end up executing two commands
+		 * at _once_.  ...just so you know why the restore_flags()
+		 * is here...
+		 */
+
+		spin_unlock_irqrestore(&hostdata->lock, flags);
+
+/* We are not connected to a target - check to see if there
+ * are commands waiting to be executed.
+ */
+
+		wd33c93_execute(instance);
+		break;
+
+/* Note: this interrupt should not occur in a LEVEL2 command */
+
+	case CSR_SELECT:
+		DB(DB_INTR, printk("SELECT"))
+		    hostdata->connected = cmd =
+		    (struct scsi_cmnd *) hostdata->selecting;
+		hostdata->selecting = NULL;
+
+		/* construct an IDENTIFY message with correct disconnect bit */
+
+		hostdata->outgoing_msg[0] = (0x80 | 0x00 | cmd->device->lun);
+		if (cmd->SCp.phase)
+			hostdata->outgoing_msg[0] |= 0x40;
+
+		if (hostdata->sync_stat[cmd->device->id] == SS_FIRST) {
+#ifdef SYNC_DEBUG
+			printk(" sending SDTR ");
+#endif
+
+			hostdata->sync_stat[cmd->device->id] = SS_WAITING;
+
+/* Tack on a 2nd message to ask about synchronous transfers. If we've
+ * been asked to do only asynchronous transfers on this device, we
+ * request a fifo depth of 0, which is equivalent to async - should
+ * solve the problems some people have had with GVP's Guru ROM.
+ */
+
+			hostdata->outgoing_msg[1] = EXTENDED_MESSAGE;
+			hostdata->outgoing_msg[2] = 3;
+			hostdata->outgoing_msg[3] = EXTENDED_SDTR;
+			if (hostdata->no_sync & (1 << cmd->device->id)) {
+				hostdata->outgoing_msg[4] =
+				    hostdata->default_sx_per / 4;
+				hostdata->outgoing_msg[5] = 0;
+			} else {
+				hostdata->outgoing_msg[4] = OPTIMUM_SX_PER / 4;
+				hostdata->outgoing_msg[5] = OPTIMUM_SX_OFF;
+			}
+			hostdata->outgoing_len = 6;
+		} else
+			hostdata->outgoing_len = 1;
+
+		hostdata->state = S_CONNECTED;
+		spin_unlock_irqrestore(&hostdata->lock, flags);
+		break;
+
+	case CSR_XFER_DONE | PHS_DATA_IN:
+	case CSR_UNEXP | PHS_DATA_IN:
+	case CSR_SRV_REQ | PHS_DATA_IN:
+		DB(DB_INTR,
+		   printk("IN-%d.%d", cmd->SCp.this_residual,
+			  cmd->SCp.buffers_residual))
+		    transfer_bytes(regs, cmd, DATA_IN_DIR);
+		if (hostdata->state != S_RUNNING_LEVEL2)
+			hostdata->state = S_CONNECTED;
+		spin_unlock_irqrestore(&hostdata->lock, flags);
+		break;
+
+	case CSR_XFER_DONE | PHS_DATA_OUT:
+	case CSR_UNEXP | PHS_DATA_OUT:
+	case CSR_SRV_REQ | PHS_DATA_OUT:
+		DB(DB_INTR,
+		   printk("OUT-%d.%d", cmd->SCp.this_residual,
+			  cmd->SCp.buffers_residual))
+		    transfer_bytes(regs, cmd, DATA_OUT_DIR);
+		if (hostdata->state != S_RUNNING_LEVEL2)
+			hostdata->state = S_CONNECTED;
+		spin_unlock_irqrestore(&hostdata->lock, flags);
+		break;
+
+/* Note: this interrupt should not occur in a LEVEL2 command */
+
+	case CSR_XFER_DONE | PHS_COMMAND:
+	case CSR_UNEXP | PHS_COMMAND:
+	case CSR_SRV_REQ | PHS_COMMAND:
+		DB(DB_INTR, printk("CMND-%02x,%ld", cmd->cmnd[0], cmd->pid))
+		    transfer_pio(regs, cmd->cmnd, cmd->cmd_len, DATA_OUT_DIR,
+				 hostdata);
+		hostdata->state = S_CONNECTED;
+		spin_unlock_irqrestore(&hostdata->lock, flags);
+		break;
+
+	case CSR_XFER_DONE | PHS_STATUS:
+	case CSR_UNEXP | PHS_STATUS:
+	case CSR_SRV_REQ | PHS_STATUS:
+		DB(DB_INTR, printk("STATUS="))
+		cmd->SCp.Status = read_1_byte(regs);
+		DB(DB_INTR, printk("%02x", cmd->SCp.Status))
+		    if (hostdata->level2 >= L2_BASIC) {
+			sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
+			hostdata->state = S_RUNNING_LEVEL2;
+			write_wd33c93(regs, WD_COMMAND_PHASE, 0x50);
+			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
+		} else {
+			hostdata->state = S_CONNECTED;
+		}
+		spin_unlock_irqrestore(&hostdata->lock, flags);
+		break;
+
+	case CSR_XFER_DONE | PHS_MESS_IN:
+	case CSR_UNEXP | PHS_MESS_IN:
+	case CSR_SRV_REQ | PHS_MESS_IN:
+		DB(DB_INTR, printk("MSG_IN="))
+
+		msg = read_1_byte(regs);
+		sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
+
+		hostdata->incoming_msg[hostdata->incoming_ptr] = msg;
+		if (hostdata->incoming_msg[0] == EXTENDED_MESSAGE)
+			msg = EXTENDED_MESSAGE;
+		else
+			hostdata->incoming_ptr = 0;
+
+		cmd->SCp.Message = msg;
+		switch (msg) {
+
+		case COMMAND_COMPLETE:
+			DB(DB_INTR, printk("CCMP-%ld", cmd->pid))
+			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
+			hostdata->state = S_PRE_CMP_DISC;
+			break;
+
+		case SAVE_POINTERS:
+			DB(DB_INTR, printk("SDP"))
+			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
+			hostdata->state = S_CONNECTED;
+			break;
+
+		case RESTORE_POINTERS:
+			DB(DB_INTR, printk("RDP"))
+			    if (hostdata->level2 >= L2_BASIC) {
+				write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
+				write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
+				hostdata->state = S_RUNNING_LEVEL2;
+			} else {
+				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
+				hostdata->state = S_CONNECTED;
+			}
+			break;
+
+		case DISCONNECT:
+			DB(DB_INTR, printk("DIS"))
+			    cmd->device->disconnect = 1;
+			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
+			hostdata->state = S_PRE_TMP_DISC;
+			break;
+
+		case MESSAGE_REJECT:
+			DB(DB_INTR, printk("REJ"))
+#ifdef SYNC_DEBUG
+			    printk("-REJ-");
+#endif
+			if (hostdata->sync_stat[cmd->device->id] == SS_WAITING)
+				hostdata->sync_stat[cmd->device->id] = SS_SET;
+			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
+			hostdata->state = S_CONNECTED;
+			break;
+
+		case EXTENDED_MESSAGE:
+			DB(DB_INTR, printk("EXT"))
+
+			    ucp = hostdata->incoming_msg;
+
+#ifdef SYNC_DEBUG
+			printk("%02x", ucp[hostdata->incoming_ptr]);
+#endif
+			/* Is this the last byte of the extended message? */
+
+			if ((hostdata->incoming_ptr >= 2) &&
+			    (hostdata->incoming_ptr == (ucp[1] + 1))) {
+
+				switch (ucp[2]) {	/* what's the EXTENDED code? */
+				case EXTENDED_SDTR:
+					id = calc_sync_xfer(ucp[3], ucp[4]);
+					if (hostdata->sync_stat[cmd->device->id] !=
+					    SS_WAITING) {
+
+/* A device has sent an unsolicited SDTR message; rather than go
+ * through the effort of decoding it and then figuring out what
+ * our reply should be, we're just gonna say that we have a
+ * synchronous fifo depth of 0. This will result in asynchronous
+ * transfers - not ideal but so much easier.
+ * Actually, this is OK because it assures us that if we don't
+ * specifically ask for sync transfers, we won't do any.
+ */
+
+						write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
+						hostdata->outgoing_msg[0] =
+						    EXTENDED_MESSAGE;
+						hostdata->outgoing_msg[1] = 3;
+						hostdata->outgoing_msg[2] =
+						    EXTENDED_SDTR;
+						hostdata->outgoing_msg[3] =
+