Linux-2.6.12-rc2

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

Let it rip!

1 files changed, 2323 insertions, 0 deletions

diff --git a/drivers/scsi/in2000.c b/drivers/scsi/in2000.c
new file mode 100644
index 000000000000..0bb0369efb2d
--- /dev/null
+++ b/drivers/scsi/in2000.c
@@ -0,0 +1,2323 @@
+/*
+ *    in2000.c -  Linux device driver for the
+ *                Always IN2000 ISA SCSI card.
+ *
+ * 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.
+ *
+ * For the avoidance of doubt the "preferred form" of this code is one which
+ * is in an open non patent encumbered format. Where cryptographic key signing
+ * forms part of the process of creating an executable the information
+ * including keys needed to generate an equivalently functional executable
+ * are deemed to be part of the source code.
+ *
+ * Drew Eckhardt's excellent 'Generic NCR5380' sources provided
+ * much of the inspiration and some of the code for this driver.
+ * The Linux IN2000 driver distributed in the Linux kernels through
+ * version 1.2.13 was an extremely valuable reference on the arcane
+ * (and still mysterious) workings of the IN2000's fifo. It also
+ * is where I lifted in2000_biosparam(), the gist of the card
+ * detection scheme, and other bits of code. Many thanks to the
+ * talented and courageous people who wrote, contributed to, and
+ * maintained that driver (including Brad McLean, Shaun Savage,
+ * Bill Earnest, Larry Doolittle, Roger Sunshine, John Luckey,
+ * Matt Postiff, Peter Lu, zerucha@shell.portal.com, and Eric
+ * Youngdale). I should also mention the driver written by
+ * Hamish Macdonald for the (GASP!) Amiga A2091 card, included
+ * in the Linux-m68k distribution; it gave me a good initial
+ * understanding of the proper way to run a WD33c93 chip, and I
+ * ended up stealing lots of code from it.
+ *
+ * _This_ driver is (I feel) an improvement over the old one in
+ * several respects:
+ *    -  All problems relating to the data size of a SCSI request are
+ *          gone (as far as I know). The old driver couldn't handle
+ *          swapping to partitions because that involved 4k blocks, nor
+ *          could it deal with the st.c tape driver unmodified, because
+ *          that usually involved 4k - 32k blocks. The old driver never
+ *          quite got away from a morbid dependence on 2k block sizes -
+ *          which of course is the size of the card's fifo.
+ *
+ *    -  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'm
+ *          calling '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 there
+ *          are a few devices (and many improperly terminated systems)
+ *          that choke when doing sync, the default is sync DISABLED
+ *          for all devices. This faster protocol can (and should!)
+ *          be enabled on selected devices via the command-line.
+ *
+ *    -  Runtime operating parameters can now be specified through
+ *       either the LILO or the 'insmod' command line. For LILO do:
+ *          "in2000=blah,blah,blah"
+ *       and with insmod go like:
+ *          "insmod /usr/src/linux/modules/in2000.o setup_strings=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.
+ *
+ *    -  You can force detection of a card whose BIOS has been disabled.
+ *
+ *    -  Multiple IN2000 cards might almost be supported. I've tried to
+ *       keep it in mind, but have no way to test...
+ *
+ *
+ * TODO:
+ *       tagged queuing. multiple cards.
+ *
+ *
+ * NOTE:
+ *       When using this or any other SCSI driver as a module, you'll
+ *       find that with the stock kernel, at most _two_ SCSI hard
+ *       drives will be linked into the device list (ie, usable).
+ *       If your IN2000 card has more than 2 disks on its bus, you
+ *       might want to change the define of 'SD_EXTRA_DEVS' in the
+ *       'hosts.h' file from 2 to whatever is appropriate. It took
+ *       me a while to track down this surprisingly obscure and
+ *       undocumented little "feature".
+ *
+ *
+ * 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".
+ *
+ * Updated for Linux 2.5 by Alan Cox <alan@redhat.com>
+ *	- Using new_eh handler
+ *	- Hopefully got all the locking right again
+ *	See "FIXME" notes for items that could do with more work
+ */
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/interrupt.h>
+#include <linux/string.h>
+#include <linux/delay.h>
+#include <linux/proc_fs.h>
+#include <linux/ioport.h>
+#include <linux/stat.h>
+
+#include <asm/io.h>
+#include <asm/system.h>
+
+#include "scsi.h"
+#include <scsi/scsi_host.h>
+
+#define IN2000_VERSION    "1.33-2.5"
+#define IN2000_DATE       "2002/11/03"
+
+#include "in2000.h"
+
+
+/*
+ * '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 a LILO or insmod command-line, those
+ * settings are combined with 'setup_args[]'. Note that LILO command-lines
+ * are prefixed with "in2000=" while insmod uses a "setup_strings=" prefix.
+ * The driver recognizes the following keywords (lower case required) and
+ * arguments:
+ *
+ * -  ioport:addr    -Where addr is IO address of a (usually ROM-less) card.
+ * -  noreset        -No optional args. Prevents SCSI bus reset at boot time.
+ * -  nosync:x       -x is a bitmask where the 1st 7 bits correspond with
+ *                    the 7 possible SCSI devices (bit 0 for device #0, etc).
+ *                    Set a bit to PREVENT sync negotiation on that device.
+ *                    The driver default is sync DISABLED on all devices.
+ * -  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 bitmask that causes
+ *                    various types of debug output to printed - see the DB_xxx
+ *                    defines in in2000.h
+ * -  proc:x         -If 'PROC_INTERFACE' is defined, x is a bitmask that
+ *                    determines how the /proc interface works and what it
+ *                    does - see the PR_xxx defines in in2000.h
+ *
+ * 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.
+ *
+ * A few LILO examples (for insmod, use 'setup_strings' instead of 'in2000'):
+ * -  in2000=ioport:0x220,noreset
+ * -  in2000=period:250,disconnect:2,nosync:0x03
+ * -  in2000=debug:0x1e
+ * -  in2000=proc:3
+ */
+
+/* Normally, no defaults are specified... */
+static char *setup_args[] = { "", "", "", "", "", "", "", "", "" };
+
+/* filled in by 'insmod' */
+static char *setup_strings;
+
+module_param(setup_strings, charp, 0);
+
+static inline uchar read_3393(struct IN2000_hostdata *hostdata, uchar reg_num)
+{
+	write1_io(reg_num, IO_WD_ADDR);
+	return read1_io(IO_WD_DATA);
+}
+
+
+#define READ_AUX_STAT() read1_io(IO_WD_ASR)
+
+
+static inline void write_3393(struct IN2000_hostdata *hostdata, uchar reg_num, uchar value)
+{
+	write1_io(reg_num, IO_WD_ADDR);
+	write1_io(value, IO_WD_DATA);
+}
+
+
+static inline void write_3393_cmd(struct IN2000_hostdata *hostdata, uchar cmd)
+{
+/*   while (READ_AUX_STAT() & ASR_CIP)
+      printk("|");*/
+	write1_io(WD_COMMAND, IO_WD_ADDR);
+	write1_io(cmd, IO_WD_DATA);
+}
+
+
+static uchar read_1_byte(struct IN2000_hostdata *hostdata)
+{
+	uchar asr, x = 0;
+
+	write_3393(hostdata, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
+	write_3393_cmd(hostdata, WD_CMD_TRANS_INFO | 0x80);
+	do {
+		asr = READ_AUX_STAT();
+		if (asr & ASR_DBR)
+			x = read_3393(hostdata, WD_DATA);
+	} while (!(asr & ASR_INT));
+	return x;
+}
+
+
+static void write_3393_count(struct IN2000_hostdata *hostdata, unsigned long value)
+{
+	write1_io(WD_TRANSFER_COUNT_MSB, IO_WD_ADDR);
+	write1_io((value >> 16), IO_WD_DATA);
+	write1_io((value >> 8), IO_WD_DATA);
+	write1_io(value, IO_WD_DATA);
+}
+
+
+static unsigned long read_3393_count(struct IN2000_hostdata *hostdata)
+{
+	unsigned long value;
+
+	write1_io(WD_TRANSFER_COUNT_MSB, IO_WD_ADDR);
+	value = read1_io(IO_WD_DATA) << 16;
+	value |= read1_io(IO_WD_DATA) << 8;
+	value |= read1_io(IO_WD_DATA);
+	return value;
+}
+
+
+/* The 33c93 needs to be told which direction a command transfers its
+ * data; we use this function to figure it out. Returns true if there
+ * will be a DATA_OUT phase with this command, false otherwise.
+ * (Thanks to Joerg Dorchain for the research and suggestion.)
+ */
+static int is_dir_out(Scsi_Cmnd * cmd)
+{
+	switch (cmd->cmnd[0]) {
+	case WRITE_6:
+	case WRITE_10:
+	case WRITE_12:
+	case WRITE_LONG:
+	case WRITE_SAME:
+	case WRITE_BUFFER:
+	case WRITE_VERIFY:
+	case WRITE_VERIFY_12:
+	case COMPARE:
+	case COPY:
+	case COPY_VERIFY:
+	case SEARCH_EQUAL:
+	case SEARCH_HIGH:
+	case SEARCH_LOW:
+	case SEARCH_EQUAL_12:
+	case SEARCH_HIGH_12:
+	case SEARCH_LOW_12:
+	case FORMAT_UNIT:
+	case REASSIGN_BLOCKS:
+	case RESERVE:
+	case MODE_SELECT:
+	case MODE_SELECT_10:
+	case LOG_SELECT:
+	case SEND_DIAGNOSTIC:
+	case CHANGE_DEFINITION:
+	case UPDATE_BLOCK:
+	case SET_WINDOW:
+	case MEDIUM_SCAN:
+	case SEND_VOLUME_TAG:
+	case 0xea:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+
+
+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;
+}
+
+
+
+static void in2000_execute(struct Scsi_Host *instance);
+
+static int in2000_queuecommand(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
+{
+	struct Scsi_Host *instance;
+	struct IN2000_hostdata *hostdata;
+	Scsi_Cmnd *tmp;
+
+	instance = cmd->device->host;
+	hostdata = (struct IN2000_hostdata *) instance->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 helps keep track of >2048 byte transfers
+ *  - 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 = (char *) 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;
+	}
+	cmd->SCp.have_data_in = 0;
+
+/* We don't set SCp.phase here - that's done in in2000_execute() */
+
+/* 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;
+
+/* We need to disable interrupts before messing with the input
+ * queue and calling in2000_execute().
+ */
+
+	/*
+	 * 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.
+	 */
+
+	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 = (Scsi_Cmnd *) hostdata->input_Q; tmp->host_scribble; tmp = (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!
+ */
+
+	in2000_execute(cmd->device->host);
+
+	DB(DB_QUEUE_COMMAND, printk(")Q-%ld ", cmd->pid))
+	    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.
+ * Note that this function is always called with interrupts already
+ * disabled (either from in2000_queuecommand() or in2000_intr()).
+ */
+static void in2000_execute(struct Scsi_Host *instance)
+{
+	struct IN2000_hostdata *hostdata;
+	Scsi_Cmnd *cmd, *prev;
+	int i;
+	unsigned short *sp;
+	unsigned short f;
+	unsigned short flushbuf[16];
+
+
+	hostdata = (struct IN2000_hostdata *) instance->hostdata;
+
+	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 = (Scsi_Cmnd *) hostdata->input_Q;
+	prev = NULL;
+	while (cmd) {
+		if (!(hostdata->busy[cmd->device->id] & (1 << cmd->device->lun)))
+			break;
+		prev = cmd;
+		cmd = (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 = (Scsi_Cmnd *) cmd->host_scribble;
+
+#ifdef PROC_STATISTICS
+	hostdata->cmd_cnt[cmd->device->id]++;
+#endif
+
+/*
+ * Start the selection process
+ */
+
+	if (is_dir_out(cmd))
+		write_3393(hostdata, WD_DESTINATION_ID, cmd->device->id);
+	else
+		write_3393(hostdata, 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 = (Scsi_Cmnd *) hostdata->input_Q; prev; prev = (Scsi_Cmnd *) prev->host_scribble) {
+		if ((prev->device->id != cmd->device->id) || (prev->device->lun != cmd->device->lun)) {
+			for (prev = (Scsi_Cmnd *) hostdata->input_Q; prev; prev = (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_3393(hostdata, WD_SOURCE_ID, ((cmd->SCp.phase) ? SRCID_ER : 0));
+
+	write_3393(hostdata, WD_TARGET_LUN, cmd->device->lun);
+	write_3393(hostdata, 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 SS_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,
+ * unless we don't want to even _try_ synchronous transfers: In this
+ * case we set SS_SET to make the defaults final.
+ */
+		if (hostdata->sync_stat[cmd->device->id] == SS_UNSET) {
+			if (hostdata->sync_off & (1 << cmd->device->id))
+				hostdata->sync_stat[cmd->device->id] = SS_SET;
+			else
+				hostdata->sync_stat[cmd->device->id] = SS_FIRST;
+		}
+		hostdata->state = S_SELECTING;
+		write_3393_count(hostdata, 0);	/* this guarantees a DATA_PHASE interrupt */
+		write_3393_cmd(hostdata, 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_3393(hostdata, WD_COMMAND_PHASE, 0);
+
+		/* copy command_descriptor_block into WD chip
+		 * (take advantage of auto-incrementing)
+		 */
+
+		write1_io(WD_CDB_1, IO_WD_ADDR);
+		for (i = 0; i < cmd->cmd_len; i++)
+			write1_io(cmd->cmnd[i], IO_WD_DATA);
+
+		/* 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_3393(hostdata, WD_OWN_ID, cmd->cmd_len);
+
+		/* When doing a non-disconnect command, we can save ourselves a DATA
+		 * phase interrupt later by setting everything up now. With writes we
+		 * need to pre-fill the fifo; if there's room for the 32 flush bytes,
+		 * put them in there too - that'll avoid a fifo interrupt. Reads are
+		 * somewhat simpler.
+		 * KLUDGE NOTE: It seems that you can't completely fill the fifo here:
+		 * This results in the IO_FIFO_COUNT register rolling over to zero,
+		 * and apparently the gate array logic sees this as empty, not full,
+		 * so the 3393 chip is never signalled to start reading from the
+		 * fifo. Or maybe it's seen as a permanent fifo interrupt condition.
+		 * Regardless, we fix this by temporarily pretending that the fifo
+		 * is 16 bytes smaller. (I see now that the old driver has a comment
+		 * about "don't fill completely" in an analogous place - must be the
+		 * same deal.) This results in CDROM, swap partitions, and tape drives
+		 * needing an extra interrupt per write command - I think we can live
+		 * with that!
+		 */
+
+		if (!(cmd->SCp.phase)) {
+			write_3393_count(hostdata, cmd->SCp.this_residual);
+			write_3393(hostdata, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_BUS);
+			write1_io(0, IO_FIFO_WRITE);	/* clear fifo counter, write mode */
+
+			if (is_dir_out(cmd)) {
+				hostdata->fifo = FI_FIFO_WRITING;
+				if ((i = cmd->SCp.this_residual) > (IN2000_FIFO_SIZE - 16))
+					i = IN2000_FIFO_SIZE - 16;
+				cmd->SCp.have_data_in = i;	/* this much data in fifo */
+				i >>= 1;	/* Gulp. Assuming modulo 2. */
+				sp = (unsigned short *) cmd->SCp.ptr;
+				f = hostdata->io_base + IO_FIFO;
+
+#ifdef FAST_WRITE_IO
+
+				FAST_WRITE2_IO();
+#else
+				while (i--)
+					write2_io(*sp++, IO_FIFO);
+
+#endif
+
+				/* Is there room for the flush bytes? */
+
+				if (cmd->SCp.have_data_in <= ((IN2000_FIFO_SIZE - 16) - 32)) {
+					sp = flushbuf;
+					i = 16;
+
+#ifdef FAST_WRITE_IO
+
+					FAST_WRITE2_IO();
+#else
+					while (i--)
+						write2_io(0, IO_FIFO);
+
+#endif
+
+				}
+			}
+
+			else {
+				write1_io(0, IO_FIFO_READ);	/* put fifo in read mode */
+				hostdata->fifo = FI_FIFO_READING;
+				cmd->SCp.have_data_in = 0;	/* nothing transferred yet */
+			}
+
+		} else {
+			write_3393_count(hostdata, 0);	/* this guarantees a DATA_PHASE interrupt */
+		}
+		hostdata->state = S_RUNNING_LEVEL2;
+		write_3393_cmd(hostdata, 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(uchar * buf, int cnt, int data_in_dir, struct IN2000_hostdata *hostdata)
+{
+	uchar asr;
+
+	DB(DB_TRANSFER, printk("(%p,%d,%s)", buf, cnt, data_in_dir ? "in" : "out"))
+
+	    write_3393(hostdata, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
+	write_3393_count(hostdata, cnt);
+	write_3393_cmd(hostdata, WD_CMD_TRANS_INFO);
+	if (data_in_dir) {
+		do {
+			asr = READ_AUX_STAT();
+			if (asr & ASR_DBR)
+				*buf++ = read_3393(hostdata, WD_DATA);
+		} while (!(asr & ASR_INT));
+	} else {
+		do {
+			asr = READ_AUX_STAT();
+			if (asr & ASR_DBR)
+				write_3393(hostdata, 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(Scsi_Cmnd * cmd, int data_in_dir)
+{
+	struct IN2000_hostdata *hostdata;
+	unsigned short *sp;
+	unsigned short f;
+	int i;
+
+	hostdata = (struct IN2000_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;
+	}
+
+/* Set up hardware registers */
+
+	write_3393(hostdata, WD_SYNCHRONOUS_TRANSFER, hostdata->sync_xfer[cmd->device->id]);
+	write_3393_count(hostdata, cmd->SCp.this_residual);
+	write_3393(hostdata, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_BUS);
+	write1_io(0, IO_FIFO_WRITE);	/* zero counter, assume write */
+
+/* Reading is easy. Just issue the command and return - we'll
+ * get an interrupt later when we have actual data to worry about.
+ */
+
+	if (data_in_dir) {
+		write1_io(0, IO_FIFO_READ);
+		if ((hostdata->level2 >= L2_DATA) || (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) {
+			write_3393(hostdata, WD_COMMAND_PHASE, 0x45);
+			write_3393_cmd(hostdata, WD_CMD_SEL_ATN_XFER);
+			hostdata->state = S_RUNNING_LEVEL2;
+		} else
+			write_3393_cmd(hostdata, WD_CMD_TRANS_INFO);
+		hostdata->fifo = FI_FIFO_READING;
+		cmd->SCp.have_data_in = 0;
+		return;
+	}
+
+/* Writing is more involved - we'll start the WD chip and write as
+ * much data to the fifo as we can right now. Later interrupts will
+ * write any bytes that don't make it at this stage.
+ */
+
+	if ((hostdata->level2 >= L2_DATA) || (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) {
+		write_3393(hostdata, WD_COMMAND_PHASE, 0x45);
+		write_3393_cmd(hostdata, WD_CMD_SEL_ATN_XFER);
+		hostdata->state = S_RUNNING_LEVEL2;
+	} else
+		write_3393_cmd(hostdata, WD_CMD_TRANS_INFO);
+	hostdata->fifo = FI_FIFO_WRITING;
+	sp = (unsigned short *) cmd->SCp.ptr;
+
+	if ((i = cmd->SCp.this_residual) > IN2000_FIFO_SIZE)
+		i = IN2000_FIFO_SIZE;
+	cmd->SCp.have_data_in = i;
+	i >>= 1;		/* Gulp. We assume this_residual is modulo 2 */
+	f = hostdata->io_base + IO_FIFO;
+
+#ifdef FAST_WRITE_IO
+
+	FAST_WRITE2_IO();
+#else
+	while (i--)
+		write2_io(*sp++, IO_FIFO);
+
+#endif
+
+}
+
+
+/* We need to use spin_lock_irqsave() & spin_unlock_irqrestore() in this
+ * function in order to work in an SMP environment. (I'd be surprised
+ * if the driver is ever used by anyone on a real multi-CPU motherboard,
+ * but it _does_ need to be able to compile and run in an SMP kernel.)
+ */
+
+static irqreturn_t in2000_intr(int irqnum, void *dev_id, struct pt_regs *ptregs)
+{
+	struct Scsi_Host *instance = dev_id;
+	struct IN2000_hostdata *hostdata;
+	Scsi_Cmnd *patch, *cmd;
+	uchar asr, sr, phs, id, lun, *ucp, msg;
+	int i, j;
+	unsigned long length;
+	unsigned short *sp;
+	unsigned short f;
+	unsigned long flags;
+
+	hostdata = (struct IN2000_hostdata *) instance->hostdata;
+
+/* Get the spin_lock and disable further ints, for SMP */
+
+	spin_lock_irqsave(instance->host_lock, flags);
+
+#ifdef PROC_STATISTICS
+	hostdata->int_cnt++;
+#endif
+
+/* The IN2000 card has 2 interrupt sources OR'ed onto its IRQ line - the
+ * WD3393 chip and the 2k fifo (which is actually a dual-port RAM combined
+ * with a big logic array, so it's a little different than what you might
+ * expect). As far as I know, there's no reason that BOTH can't be active
+ * at the same time, but there's a problem: while we can read the 3393
+ * to tell if _it_ wants an interrupt, I don't know of a way to ask the
+ * fifo the same question. The best we can do is check the 3393 and if
+ * it _isn't_ the source of the interrupt, then we can be pretty sure
+ * that the fifo is the culprit.
+ *  UPDATE: I have it on good authority (Bill Earnest) that bit 0 of the
+ *          IO_FIFO_COUNT register mirrors the fifo interrupt state. I
+ *          assume that bit clear means interrupt active. As it turns
+ *          out, the driver really doesn't need to check for this after
+ *          all, so my remarks above about a 'problem' can safely be
+ *          ignored. The way the logic is set up, there's no advantage
+ *          (that I can see) to worrying about it.
+ *
+ * It seems that the fifo interrupt signal is negated when we extract
+ * bytes during read or write bytes during write.
+ *  - fifo will interrupt when data is moving from it to the 3393, and
+ *    there are 31 (or less?) bytes left to go. This is sort of short-
+ *    sighted: what if you don't WANT to do more? In any case, our
+ *    response is to push more into the fifo - either actual data or
+ *    dummy bytes if need be. Note that we apparently have to write at
+ *    least 32 additional bytes to the fifo after an interrupt in order
+ *    to get it to release the ones it was holding on to - writing fewer
+ *    than 32 will result in another fifo int.
+ *  UPDATE: Again, info from Bill Earnest makes this more understandable:
+ *          32 bytes = two counts of the fifo counter register. He tells
+ *          me that the fifo interrupt is a non-latching signal derived
+ *          from a straightforward boolean interpretation of the 7
+ *          highest bits of the fifo counter and the fifo-read/fifo-write
+ *          state. Who'd a thought?
+ */
+
+	write1_io(0, IO_LED_ON);
+	asr = READ_AUX_STAT();
+	if (!(asr & ASR_INT)) {	/* no WD33c93 interrupt? */
+
+/* Ok. This is definitely a FIFO-only interrupt.
+ *
+ * If FI_FIFO_READING is set, there are up to 2048 bytes waiting to be read,
+ * maybe more to come from the SCSI bus. Read as many as we can out of the
+ * fifo and into memory at the location of SCp.ptr[SCp.have_data_in], and
+ * update have_data_in afterwards.
+ *
+ * If we have FI_FIFO_WRITING, the FIFO has almost run out of bytes to move
+ * into the WD3393 chip (I think the interrupt happens when there are 31
+ * bytes left, but it may be fewer...). The 3393 is still waiting, so we
+ * shove some more into the fifo, which gets things moving again. If the
+ * original SCSI command specified more than 2048 bytes, there may still
+ * be some of that data left: fine - use it (from SCp.ptr[SCp.have_data_in]).
+ * Don't forget to update have_data_in. If we've already written out the
+ * entire buffer, feed 32 dummy bytes to the fifo - they're needed to
+ * push out the remaining real data.
+ *    (Big thanks to Bill Earnest for getting me out of the mud in here.)
+ */
+
+		cmd = (Scsi_Cmnd *) hostdata->connected;	/* assume we're connected */
+		CHECK_NULL(cmd, "fifo_int")
+
+		    if (hostdata->fifo == FI_FIFO_READING) {
+
+			DB(DB_FIFO, printk("{R:%02x} ", read1_io(IO_FIFO_COUNT)))
+
+			    sp = (unsigned short *) (cmd->SCp.ptr + cmd->SCp.have_data_in);
+			i = read1_io(IO_FIFO_COUNT) & 0xfe;
+			i <<= 2;	/* # of words waiting in the fifo */
+			f = hostdata->io_base + IO_FIFO;
+
+#ifdef FAST_READ_IO
+
+			FAST_READ2_IO();
+#else
+			while (i--)
+				*sp++ = read2_io(IO_FIFO);
+
+#endif
+
+			i = sp - (unsigned short *) (cmd->SCp.ptr + cmd->SCp.have_data_in);
+			i <<= 1;
+			cmd->SCp.have_data_in += i;
+		}
+
+		else if (hostdata->fifo == FI_FIFO_WRITING) {
+
+			DB(DB_FIFO, printk("{W:%02x} ", read1_io(IO_FIFO_COUNT)))
+
+/* If all bytes have been written to the fifo, flush out the stragglers.
+ * Note that while writing 16 dummy words seems arbitrary, we don't
+ * have another choice that I can see. What we really want is to read
+ * the 3393 transfer count register (that would tell us how many bytes
+ * needed flushing), but the TRANSFER_INFO command hasn't completed
+ * yet (not enough bytes!) and that register won't be accessible. So,
+ * we use 16 words - a number obtained through trial and error.
+ *  UPDATE: Bill says this is exactly what Always does, so there.
+ *          More thanks due him for help in this section.
+ */
+			    if (cmd->SCp.this_residual == cmd->SCp.have_data_in) {
+				i = 16;
+				while (i--)	/* write 32 dummy bytes */
+					write2_io(0, IO_FIFO);
+			}
+
+/* If there are still bytes left in the SCSI buffer, write as many as we
+ * can out to the fifo.
+ */
+
+			else {
+				sp = (unsigned short *) (cmd->SCp.ptr + cmd->SCp.have_data_in);
+				i = cmd->SCp.this_residual - cmd->SCp.have_data_in;	/* bytes yet to go */
+				j = read1_io(IO_FIFO_COUNT) & 0xfe;
+				j <<= 2;	/* how many words the fifo has room for */
+				if ((j << 1) > i)
+					j = (i >> 1);
+				while (j--)
+					write2_io(*sp++, IO_FIFO);
+
+				i = sp - (unsigned short *) (cmd->SCp.ptr + cmd->SCp.have_data_in);
+				i <<= 1;
+				cmd->SCp.have_data_in += i;
+			}
+		}
+
+		else {
+			printk("*** Spurious FIFO interrupt ***");
+		}
+
+		write1_io(0, IO_LED_OFF);
+
+/* release the SMP spin_lock and restore irq state */
+		spin_unlock_irqrestore(instance->host_lock, flags);
+		return IRQ_HANDLED;
+	}
+
+/* This interrupt was triggered by the WD33c93 chip. The fifo interrupt
+ * may also be asserted, but we don't bother to check it: we get more
+ * detailed info from FIFO_READING and FIFO_WRITING (see below).
+ */
+
+	cmd = (Scsi_Cmnd *) hostdata->connected;	/* assume we're connected */
+	sr = read_3393(hostdata, WD_SCSI_STATUS);	/* clear the interrupt */
+	phs = read_3393(hostdata, WD_COMMAND_PHASE);
+
+	if (!cmd && (sr != CSR_RESEL_AM && sr != CSR_TIMEOUT && sr != CSR_SEL