Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3018 insertions, 0 deletions

diff --git a/drivers/scsi/arm/acornscsi.c b/drivers/scsi/arm/acornscsi.c
new file mode 100644
index 000000000..ef9d907f2
--- /dev/null
+++ b/drivers/scsi/arm/acornscsi.c
@@ -0,0 +1,3018 @@
+/*
+ *  linux/drivers/acorn/scsi/acornscsi.c
+ *
+ *  Acorn SCSI 3 driver
+ *  By R.M.King.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Abandoned using the Select and Transfer command since there were
+ * some nasty races between our software and the target devices that
+ * were not easy to solve, and the device errata had a lot of entries
+ * for this command, some of them quite nasty...
+ *
+ * Changelog:
+ *  26-Sep-1997	RMK	Re-jigged to use the queue module.
+ *			Re-coded state machine to be based on driver
+ *			state not scsi state.  Should be easier to debug.
+ *			Added acornscsi_release to clean up properly.
+ *			Updated proc/scsi reporting.
+ *  05-Oct-1997	RMK	Implemented writing to SCSI devices.
+ *  06-Oct-1997	RMK	Corrected small (non-serious) bug with the connect/
+ *			reconnect race condition causing a warning message.
+ *  12-Oct-1997	RMK	Added catch for re-entering interrupt routine.
+ *  15-Oct-1997	RMK	Improved handling of commands.
+ *  27-Jun-1998	RMK	Changed asm/delay.h to linux/delay.h.
+ *  13-Dec-1998	RMK	Better abort code and command handling.  Extra state
+ *			transitions added to allow dodgy devices to work.
+ */
+#define DEBUG_NO_WRITE	1
+#define DEBUG_QUEUES	2
+#define DEBUG_DMA	4
+#define DEBUG_ABORT	8
+#define DEBUG_DISCON	16
+#define DEBUG_CONNECT	32
+#define DEBUG_PHASES	64
+#define DEBUG_WRITE	128
+#define DEBUG_LINK	256
+#define DEBUG_MESSAGES	512
+#define DEBUG_RESET	1024
+#define DEBUG_ALL	(DEBUG_RESET|DEBUG_MESSAGES|DEBUG_LINK|DEBUG_WRITE|\
+			 DEBUG_PHASES|DEBUG_CONNECT|DEBUG_DISCON|DEBUG_ABORT|\
+			 DEBUG_DMA|DEBUG_QUEUES)
+
+/* DRIVER CONFIGURATION
+ *
+ * SCSI-II Tagged queue support.
+ *
+ * I don't have any SCSI devices that support it, so it is totally untested
+ * (except to make sure that it doesn't interfere with any non-tagging
+ * devices).  It is not fully implemented either - what happens when a
+ * tagging device reconnects???
+ *
+ * You can tell if you have a device that supports tagged queueing my
+ * cating (eg) /proc/scsi/acornscsi/0 and see if the SCSI revision is reported
+ * as '2 TAG'.
+ *
+ * Also note that CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE is normally set in the config
+ * scripts, but disabled here.  Once debugged, remove the #undef, otherwise to debug,
+ * comment out the undef.
+ */
+#undef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
+/*
+ * SCSI-II Synchronous transfer support.
+ *
+ * Tried and tested...
+ *
+ * SDTR_SIZE	  - maximum number of un-acknowledged bytes (0 = off, 12 = max)
+ * SDTR_PERIOD	  - period of REQ signal (min=125, max=1020)
+ * DEFAULT_PERIOD - default REQ period.
+ */
+#define SDTR_SIZE	12
+#define SDTR_PERIOD	125
+#define DEFAULT_PERIOD	500
+
+/*
+ * Debugging information
+ *
+ * DEBUG	  - bit mask from list above
+ * DEBUG_TARGET   - is defined to the target number if you want to debug
+ *		    a specific target. [only recon/write/dma].
+ */
+#define DEBUG (DEBUG_RESET|DEBUG_WRITE|DEBUG_NO_WRITE)
+/* only allow writing to SCSI device 0 */
+#define NO_WRITE 0xFE
+/*#define DEBUG_TARGET 2*/
+/*
+ * Select timeout time (in 10ms units)
+ *
+ * This is the timeout used between the start of selection and the WD33C93
+ * chip deciding that the device isn't responding.
+ */
+#define TIMEOUT_TIME 10
+/*
+ * Define this if you want to have verbose explanation of SCSI
+ * status/messages.
+ */
+#undef CONFIG_ACORNSCSI_CONSTANTS
+/*
+ * Define this if you want to use the on board DMAC [don't remove this option]
+ * If not set, then use PIO mode (not currently supported).
+ */
+#define USE_DMAC
+
+/*
+ * ====================================================================================
+ */
+
+#ifdef DEBUG_TARGET
+#define DBG(cmd,xxx...) \
+  if (cmd->device->id == DEBUG_TARGET) { \
+    xxx; \
+  }
+#else
+#define DBG(cmd,xxx...) xxx
+#endif
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/proc_fs.h>
+#include <linux/ioport.h>
+#include <linux/blkdev.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/stringify.h>
+#include <linux/io.h>
+
+#include <asm/ecard.h>
+
+#include "../scsi.h"
+#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_transport_spi.h>
+#include "acornscsi.h"
+#include "msgqueue.h"
+#include "scsi.h"
+
+#include <scsi/scsicam.h>
+
+#define VER_MAJOR 2
+#define VER_MINOR 0
+#define VER_PATCH 6
+
+#ifndef ABORT_TAG
+#define ABORT_TAG 0xd
+#else
+#error "Yippee!  ABORT TAG is now defined!  Remove this error!"
+#endif
+
+#ifdef USE_DMAC
+/*
+ * DMAC setup parameters
+ */ 
+#define INIT_DEVCON0	(DEVCON0_RQL|DEVCON0_EXW|DEVCON0_CMP)
+#define INIT_DEVCON1	(DEVCON1_BHLD)
+#define DMAC_READ	(MODECON_READ)
+#define DMAC_WRITE	(MODECON_WRITE)
+#define INIT_SBICDMA	(CTRL_DMABURST)
+
+#define scsi_xferred	have_data_in
+
+/*
+ * Size of on-board DMA buffer
+ */
+#define DMAC_BUFFER_SIZE	65536
+#endif
+
+#define STATUS_BUFFER_TO_PRINT	24
+
+unsigned int sdtr_period = SDTR_PERIOD;
+unsigned int sdtr_size   = SDTR_SIZE;
+
+static void acornscsi_done(AS_Host *host, struct scsi_cmnd **SCpntp,
+			   unsigned int result);
+static int acornscsi_reconnect_finish(AS_Host *host);
+static void acornscsi_dma_cleanup(AS_Host *host);
+static void acornscsi_abortcmd(AS_Host *host, unsigned char tag);
+
+/* ====================================================================================
+ * Miscellaneous
+ */
+
+/* Offsets from MEMC base */
+#define SBIC_REGIDX	0x2000
+#define SBIC_REGVAL	0x2004
+#define DMAC_OFFSET	0x3000
+
+/* Offsets from FAST IOC base */
+#define INT_REG		0x2000
+#define PAGE_REG	0x3000
+
+static inline void sbic_arm_write(AS_Host *host, unsigned int reg, unsigned int value)
+{
+    writeb(reg, host->base + SBIC_REGIDX);
+    writeb(value, host->base + SBIC_REGVAL);
+}
+
+static inline int sbic_arm_read(AS_Host *host, unsigned int reg)
+{
+    if(reg == SBIC_ASR)
+	   return readl(host->base + SBIC_REGIDX) & 255;
+    writeb(reg, host->base + SBIC_REGIDX);
+    return readl(host->base + SBIC_REGVAL) & 255;
+}
+
+#define sbic_arm_writenext(host, val)	writeb((val), (host)->base + SBIC_REGVAL)
+#define sbic_arm_readnext(host) 	readb((host)->base + SBIC_REGVAL)
+
+#ifdef USE_DMAC
+#define dmac_read(host,reg) \
+	readb((host)->base + DMAC_OFFSET + ((reg) << 2))
+
+#define dmac_write(host,reg,value) \
+	({ writeb((value), (host)->base + DMAC_OFFSET + ((reg) << 2)); })
+
+#define dmac_clearintr(host) 	writeb(0, (host)->fast + INT_REG)
+
+static inline unsigned int dmac_address(AS_Host *host)
+{
+    return dmac_read(host, DMAC_TXADRHI) << 16 |
+	   dmac_read(host, DMAC_TXADRMD) << 8 |
+	   dmac_read(host, DMAC_TXADRLO);
+}
+
+static
+void acornscsi_dumpdma(AS_Host *host, char *where)
+{
+	unsigned int mode, addr, len;
+
+	mode = dmac_read(host, DMAC_MODECON);
+	addr = dmac_address(host);
+	len  = dmac_read(host, DMAC_TXCNTHI) << 8 |
+	       dmac_read(host, DMAC_TXCNTLO);
+
+	printk("scsi%d: %s: DMAC %02x @%06x+%04x msk %02x, ",
+		host->host->host_no, where,
+		mode, addr, (len + 1) & 0xffff,
+		dmac_read(host, DMAC_MASKREG));
+
+	printk("DMA @%06x, ", host->dma.start_addr);
+	printk("BH @%p +%04x, ", host->scsi.SCp.ptr,
+		host->scsi.SCp.this_residual);
+	printk("DT @+%04x ST @+%04x", host->dma.transferred,
+		host->scsi.SCp.scsi_xferred);
+	printk("\n");
+}
+#endif
+
+static
+unsigned long acornscsi_sbic_xfcount(AS_Host *host)
+{
+    unsigned long length;
+
+    length = sbic_arm_read(host, SBIC_TRANSCNTH) << 16;
+    length |= sbic_arm_readnext(host) << 8;
+    length |= sbic_arm_readnext(host);
+
+    return length;
+}
+
+static int
+acornscsi_sbic_wait(AS_Host *host, int stat_mask, int stat, int timeout, char *msg)
+{
+	int asr;
+
+	do {
+		asr = sbic_arm_read(host, SBIC_ASR);
+
+		if ((asr & stat_mask) == stat)
+			return 0;
+
+		udelay(1);
+	} while (--timeout);
+
+	printk("scsi%d: timeout while %s\n", host->host->host_no, msg);
+
+	return -1;
+}
+
+static
+int acornscsi_sbic_issuecmd(AS_Host *host, int command)
+{
+    if (acornscsi_sbic_wait(host, ASR_CIP, 0, 1000, "issuing command"))
+	return -1;
+
+    sbic_arm_write(host, SBIC_CMND, command);
+
+    return 0;
+}
+
+static void
+acornscsi_csdelay(unsigned int cs)
+{
+    unsigned long target_jiffies, flags;
+
+    target_jiffies = jiffies + 1 + cs * HZ / 100;
+
+    local_save_flags(flags);
+    local_irq_enable();
+
+    while (time_before(jiffies, target_jiffies)) barrier();
+
+    local_irq_restore(flags);
+}
+
+static
+void acornscsi_resetcard(AS_Host *host)
+{
+    unsigned int i, timeout;
+
+    /* assert reset line */
+    host->card.page_reg = 0x80;
+    writeb(host->card.page_reg, host->fast + PAGE_REG);
+
+    /* wait 3 cs.  SCSI standard says 25ms. */
+    acornscsi_csdelay(3);
+
+    host->card.page_reg = 0;
+    writeb(host->card.page_reg, host->fast + PAGE_REG);
+
+    /*
+     * Should get a reset from the card
+     */
+    timeout = 1000;
+    do {
+	if (readb(host->fast + INT_REG) & 8)
+	    break;
+	udelay(1);
+    } while (--timeout);
+
+    if (timeout == 0)
+	printk("scsi%d: timeout while resetting card\n",
+		host->host->host_no);
+
+    sbic_arm_read(host, SBIC_ASR);
+    sbic_arm_read(host, SBIC_SSR);
+
+    /* setup sbic - WD33C93A */
+    sbic_arm_write(host, SBIC_OWNID, OWNID_EAF | host->host->this_id);
+    sbic_arm_write(host, SBIC_CMND, CMND_RESET);
+
+    /*
+     * Command should cause a reset interrupt
+     */
+    timeout = 1000;
+    do {
+	if (readb(host->fast + INT_REG) & 8)
+	    break;
+	udelay(1);
+    } while (--timeout);
+
+    if (timeout == 0)
+	printk("scsi%d: timeout while resetting card\n",
+		host->host->host_no);
+
+    sbic_arm_read(host, SBIC_ASR);
+    if (sbic_arm_read(host, SBIC_SSR) != 0x01)
+	printk(KERN_CRIT "scsi%d: WD33C93A didn't give enhanced reset interrupt\n",
+		host->host->host_no);
+
+    sbic_arm_write(host, SBIC_CTRL, INIT_SBICDMA | CTRL_IDI);
+    sbic_arm_write(host, SBIC_TIMEOUT, TIMEOUT_TIME);
+    sbic_arm_write(host, SBIC_SYNCHTRANSFER, SYNCHTRANSFER_2DBA);
+    sbic_arm_write(host, SBIC_SOURCEID, SOURCEID_ER | SOURCEID_DSP);
+
+    host->card.page_reg = 0x40;
+    writeb(host->card.page_reg, host->fast + PAGE_REG);
+
+    /* setup dmac - uPC71071 */
+    dmac_write(host, DMAC_INIT, 0);
+#ifdef USE_DMAC
+    dmac_write(host, DMAC_INIT, INIT_8BIT);
+    dmac_write(host, DMAC_CHANNEL, CHANNEL_0);
+    dmac_write(host, DMAC_DEVCON0, INIT_DEVCON0);
+    dmac_write(host, DMAC_DEVCON1, INIT_DEVCON1);
+#endif
+
+    host->SCpnt = NULL;
+    host->scsi.phase = PHASE_IDLE;
+    host->scsi.disconnectable = 0;
+
+    memset(host->busyluns, 0, sizeof(host->busyluns));
+
+    for (i = 0; i < 8; i++) {
+	host->device[i].sync_state = SYNC_NEGOCIATE;
+	host->device[i].disconnect_ok = 1;
+    }
+
+    /* wait 25 cs.  SCSI standard says 250ms. */
+    acornscsi_csdelay(25);
+}
+
+/*=============================================================================================
+ * Utility routines (eg. debug)
+ */
+#ifdef CONFIG_ACORNSCSI_CONSTANTS
+static char *acornscsi_interrupttype[] = {
+  "rst",  "suc",  "p/a",  "3",
+  "term", "5",	  "6",	  "7",
+  "serv", "9",	  "a",	  "b",
+  "c",	  "d",	  "e",	  "f"
+};
+
+static signed char acornscsi_map[] = {
+  0,  1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
+ -1,  2, -1, -1,  -1, -1,  3, -1,   4,	5,  6,	7,   8,  9, 10, 11,
+ 12, 13, 14, -1,  -1, -1, -1, -1,   4,	5,  6,	7,   8,  9, 10, 11,
+ -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
+ 15, 16, 17, 18,  19, -1, -1, 20,   4,	5,  6,	7,   8,  9, 10, 11,
+ -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
+ -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
+ -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
+ 21, 22, -1, -1,  -1, 23, -1, -1,   4,	5,  6,	7,   8,  9, 10, 11,
+ -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
+ -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
+ -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
+ -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
+ -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
+ -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,
+ -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1,  -1, -1, -1, -1
+};      
+
+static char *acornscsi_interruptcode[] = {
+    /* 0 */
+    "reset - normal mode",	/* 00 */
+    "reset - advanced mode",	/* 01 */
+
+    /* 2 */
+    "sel",			/* 11 */
+    "sel+xfer", 		/* 16 */
+    "data-out", 		/* 18 */
+    "data-in",			/* 19 */
+    "cmd",			/* 1A */
+    "stat",			/* 1B */
+    "??-out",			/* 1C */
+    "??-in",			/* 1D */
+    "msg-out",			/* 1E */
+    "msg-in",			/* 1F */
+
+    /* 12 */
+    "/ACK asserted",		/* 20 */
+    "save-data-ptr",		/* 21 */
+    "{re}sel",			/* 22 */
+
+    /* 15 */
+    "inv cmd",			/* 40 */
+    "unexpected disconnect",	/* 41 */
+    "sel timeout",		/* 42 */
+    "P err",			/* 43 */
+    "P err+ATN",		/* 44 */
+    "bad status byte",		/* 47 */
+
+    /* 21 */
+    "resel, no id",		/* 80 */
+    "resel",			/* 81 */
+    "discon",			/* 85 */
+};
+
+static
+void print_scsi_status(unsigned int ssr)
+{
+    if (acornscsi_map[ssr] != -1)
+	printk("%s:%s",
+		acornscsi_interrupttype[(ssr >> 4)],
+		acornscsi_interruptcode[acornscsi_map[ssr]]);
+    else
+	printk("%X:%X", ssr >> 4, ssr & 0x0f);    
+}    
+#endif
+
+static
+void print_sbic_status(int asr, int ssr, int cmdphase)
+{
+#ifdef CONFIG_ACORNSCSI_CONSTANTS
+    printk("sbic: %c%c%c%c%c%c ",
+	    asr & ASR_INT ? 'I' : 'i',
+	    asr & ASR_LCI ? 'L' : 'l',
+	    asr & ASR_BSY ? 'B' : 'b',
+	    asr & ASR_CIP ? 'C' : 'c',
+	    asr & ASR_PE  ? 'P' : 'p',
+	    asr & ASR_DBR ? 'D' : 'd');
+    printk("scsi: ");
+    print_scsi_status(ssr);
+    printk(" ph %02X\n", cmdphase);
+#else
+    printk("sbic: %02X scsi: %X:%X ph: %02X\n",
+	    asr, (ssr & 0xf0)>>4, ssr & 0x0f, cmdphase);
+#endif
+}
+
+static void
+acornscsi_dumplogline(AS_Host *host, int target, int line)
+{
+	unsigned long prev;
+	signed int ptr;
+
+	ptr = host->status_ptr[target] - STATUS_BUFFER_TO_PRINT;
+	if (ptr < 0)
+		ptr += STATUS_BUFFER_SIZE;
+
+	printk("%c: %3s:", target == 8 ? 'H' : '0' + target,
+		line == 0 ? "ph" : line == 1 ? "ssr" : "int");
+
+	prev = host->status[target][ptr].when;
+
+	for (; ptr != host->status_ptr[target]; ptr = (ptr + 1) & (STATUS_BUFFER_SIZE - 1)) {
+		unsigned long time_diff;
+
+		if (!host->status[target][ptr].when)
+			continue;
+
+		switch (line) {
+		case 0:
+			printk("%c%02X", host->status[target][ptr].irq ? '-' : ' ',
+					 host->status[target][ptr].ph);
+			break;
+
+		case 1:
+			printk(" %02X", host->status[target][ptr].ssr);
+			break;
+
+		case 2:
+			time_diff = host->status[target][ptr].when - prev;
+			prev = host->status[target][ptr].when;
+			if (time_diff == 0)
+				printk("==^");
+			else if (time_diff >= 100)
+				printk("   ");
+			else
+				printk(" %02ld", time_diff);
+			break;
+		}
+	}
+
+	printk("\n");
+}
+
+static
+void acornscsi_dumplog(AS_Host *host, int target)
+{
+    do {
+	acornscsi_dumplogline(host, target, 0);
+	acornscsi_dumplogline(host, target, 1);
+	acornscsi_dumplogline(host, target, 2);
+
+	if (target == 8)
+	    break;
+
+	target = 8;
+    } while (1);
+}
+
+static
+char acornscsi_target(AS_Host *host)
+{
+	if (host->SCpnt)
+		return '0' + host->SCpnt->device->id;
+	return 'H';
+}
+
+/*
+ * Prototype: cmdtype_t acornscsi_cmdtype(int command)
+ * Purpose  : differentiate READ from WRITE from other commands
+ * Params   : command - command to interpret
+ * Returns  : CMD_READ	- command reads data,
+ *	      CMD_WRITE - command writes data,
+ *	      CMD_MISC	- everything else
+ */
+static inline
+cmdtype_t acornscsi_cmdtype(int command)
+{
+    switch (command) {
+    case WRITE_6:  case WRITE_10:  case WRITE_12:
+	return CMD_WRITE;
+    case READ_6:   case READ_10:   case READ_12:
+	return CMD_READ;
+    default:
+	return CMD_MISC;
+    }
+}
+
+/*
+ * Prototype: int acornscsi_datadirection(int command)
+ * Purpose  : differentiate between commands that have a DATA IN phase
+ *	      and a DATA OUT phase
+ * Params   : command - command to interpret
+ * Returns  : DATADIR_OUT - data out phase expected
+ *	      DATADIR_IN  - data in phase expected
+ */
+static
+datadir_t acornscsi_datadirection(int command)
+{
+    switch (command) {
+    case CHANGE_DEFINITION:	case COMPARE:		case COPY:
+    case COPY_VERIFY:		case LOG_SELECT:	case MODE_SELECT:
+    case MODE_SELECT_10:	case SEND_DIAGNOSTIC:	case WRITE_BUFFER:
+    case FORMAT_UNIT:		case REASSIGN_BLOCKS:	case RESERVE:
+    case SEARCH_EQUAL:		case SEARCH_HIGH:	case SEARCH_LOW:
+    case WRITE_6:		case WRITE_10:		case WRITE_VERIFY:
+    case UPDATE_BLOCK:		case WRITE_LONG:	case WRITE_SAME:
+    case SEARCH_HIGH_12:	case SEARCH_EQUAL_12:	case SEARCH_LOW_12:
+    case WRITE_12:		case WRITE_VERIFY_12:	case SET_WINDOW:
+    case MEDIUM_SCAN:		case SEND_VOLUME_TAG:	case 0xea:
+	return DATADIR_OUT;
+    default:
+	return DATADIR_IN;
+    }
+}
+
+/*
+ * Purpose  : provide values for synchronous transfers with 33C93.
+ * Copyright: Copyright (c) 1996 John Shifflett, GeoLog Consulting
+ *	Modified by Russell King for 8MHz WD33C93A
+ */
+static struct sync_xfer_tbl {
+    unsigned int period_ns;
+    unsigned char reg_value;
+} sync_xfer_table[] = {
+    {	1, 0x20 },    { 249, 0x20 },	{ 374, 0x30 },
+    { 499, 0x40 },    { 624, 0x50 },	{ 749, 0x60 },
+    { 874, 0x70 },    { 999, 0x00 },	{   0,	  0 }
+};
+
+/*
+ * Prototype: int acornscsi_getperiod(unsigned char syncxfer)
+ * Purpose  : period for the synchronous transfer setting
+ * Params   : syncxfer SYNCXFER register value
+ * Returns  : period in ns.
+ */
+static
+int acornscsi_getperiod(unsigned char syncxfer)
+{
+    int i;
+
+    syncxfer &= 0xf0;
+    if (syncxfer == 0x10)
+	syncxfer = 0;
+
+    for (i = 1; sync_xfer_table[i].period_ns; i++)
+	if (syncxfer == sync_xfer_table[i].reg_value)
+	    return sync_xfer_table[i].period_ns;
+    return 0;
+}
+
+/*
+ * Prototype: int round_period(unsigned int period)
+ * Purpose  : return index into above table for a required REQ period
+ * Params   : period - time (ns) for REQ
+ * Returns  : table index
+ * Copyright: Copyright (c) 1996 John Shifflett, GeoLog Consulting
+ */
+static inline
+int round_period(unsigned int period)
+{
+    int i;
+
+    for (i = 1; sync_xfer_table[i].period_ns; i++) {
+	if ((period <= sync_xfer_table[i].period_ns) &&
+	    (period > sync_xfer_table[i - 1].period_ns))
+	    return i;
+    }
+    return 7;
+}
+
+/*
+ * Prototype: unsigned char calc_sync_xfer(unsigned int period, unsigned int offset)
+ * Purpose  : calculate value for 33c93s SYNC register
+ * Params   : period - time (ns) for REQ
+ *	      offset - offset in bytes between REQ/ACK
+ * Returns  : value for SYNC register
+ * Copyright: Copyright (c) 1996 John Shifflett, GeoLog Consulting
+ */
+static
+unsigned char __maybe_unused calc_sync_xfer(unsigned int period,
+					    unsigned int offset)
+{
+    return sync_xfer_table[round_period(period)].reg_value |
+		((offset < SDTR_SIZE) ? offset : SDTR_SIZE);
+}
+
+/* ====================================================================================
+ * Command functions
+ */
+/*
+ * Function: acornscsi_kick(AS_Host *host)
+ * Purpose : kick next command to interface
+ * Params  : host - host to send command to
+ * Returns : INTR_IDLE if idle, otherwise INTR_PROCESSING
+ * Notes   : interrupts are always disabled!
+ */
+static
+intr_ret_t acornscsi_kick(AS_Host *host)
+{
+    int from_queue = 0;
+    struct scsi_cmnd *SCpnt;
+
+    /* first check to see if a command is waiting to be executed */
+    SCpnt = host->origSCpnt;
+    host->origSCpnt = NULL;
+
+    /* retrieve next command */
+    if (!SCpnt) {
+	SCpnt = queue_remove_exclude(&host->queues.issue, host->busyluns);
+	if (!SCpnt)
+	    return INTR_IDLE;
+
+	from_queue = 1;
+    }
+
+    if (host->scsi.disconnectable && host->SCpnt) {
+	queue_add_cmd_tail(&host->queues.disconnected, host->SCpnt);
+	host->scsi.disconnectable = 0;
+#if (DEBUG & (DEBUG_QUEUES|DEBUG_DISCON))
+	DBG(host->SCpnt, printk("scsi%d.%c: moved command to disconnected queue\n",
+		host->host->host_no, acornscsi_target(host)));
+#endif
+	host->SCpnt = NULL;
+    }
+
+    /*
+     * If we have an interrupt pending, then we may have been reselected.
+     * In this case, we don't want to write to the registers
+     */
+    if (!(sbic_arm_read(host, SBIC_ASR) & (ASR_INT|ASR_BSY|ASR_CIP))) {
+	sbic_arm_write(host, SBIC_DESTID, SCpnt->device->id);
+	sbic_arm_write(host, SBIC_CMND, CMND_SELWITHATN);
+    }
+
+    /*
+     * claim host busy - all of these must happen atomically wrt
+     * our interrupt routine.  Failure means command loss.
+     */
+    host->scsi.phase = PHASE_CONNECTING;
+    host->SCpnt = SCpnt;
+    host->scsi.SCp = SCpnt->SCp;
+    host->dma.xfer_setup = 0;
+    host->dma.xfer_required = 0;
+    host->dma.xfer_done = 0;
+
+#if (DEBUG & (DEBUG_ABORT|DEBUG_CONNECT))
+    DBG(SCpnt,printk("scsi%d.%c: starting cmd %02X\n",
+	    host->host->host_no, '0' + SCpnt->device->id,
+	    SCpnt->cmnd[0]));
+#endif
+
+    if (from_queue) {
+#ifdef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
+	/*
+	 * tagged queueing - allocate a new tag to this command
+	 */
+	if (SCpnt->device->simple_tags) {
+	    SCpnt->device->current_tag += 1;
+	    if (SCpnt->device->current_tag == 0)
+		SCpnt->device->current_tag = 1;
+	    SCpnt->tag = SCpnt->device->current_tag;
+	} else
+#endif
+	    set_bit(SCpnt->device->id * 8 +
+		    (u8)(SCpnt->device->lun & 0x07), host->busyluns);
+
+	host->stats.removes += 1;
+
+	switch (acornscsi_cmdtype(SCpnt->cmnd[0])) {
+	case CMD_WRITE:
+	    host->stats.writes += 1;
+	    break;
+	case CMD_READ:
+	    host->stats.reads += 1;
+	    break;
+	case CMD_MISC:
+	    host->stats.miscs += 1;
+	    break;
+	}
+    }
+
+    return INTR_PROCESSING;
+}    
+
+/*
+ * Function: void acornscsi_done(AS_Host *host, struct scsi_cmnd **SCpntp, unsigned int result)
+ * Purpose : complete processing for command
+ * Params  : host   - interface that completed
+ *	     result - driver byte of result
+ */
+static void acornscsi_done(AS_Host *host, struct scsi_cmnd **SCpntp,
+			   unsigned int result)
+{
+	struct scsi_cmnd *SCpnt = *SCpntp;
+
+    /* clean up */
+    sbic_arm_write(host, SBIC_SOURCEID, SOURCEID_ER | SOURCEID_DSP);
+
+    host->stats.fins += 1;
+
+    if (SCpnt) {
+	*SCpntp = NULL;
+
+	acornscsi_dma_cleanup(host);
+
+	SCpnt->result = result << 16 | host->scsi.SCp.Message << 8 | host->scsi.SCp.Status;
+
+	/*
+	 * In theory, this should not happen.  In practice, it seems to.
+	 * Only trigger an error if the device attempts to report all happy
+	 * but with untransferred buffers...  If we don't do something, then
+	 * data loss will occur.  Should we check SCpnt->underflow here?
+	 * It doesn't appear to be set to something meaningful by the higher
+	 * levels all the time.
+	 */
+	if (result == DID_OK) {
+		int xfer_warn = 0;
+
+		if (SCpnt->underflow == 0) {
+			if (host->scsi.SCp.ptr &&
+			    acornscsi_cmdtype(SCpnt->cmnd[0]) != CMD_MISC)
+				xfer_warn = 1;
+		} else {
+			if (host->scsi.SCp.scsi_xferred < SCpnt->underflow ||
+			    host->scsi.SCp.scsi_xferred != host->dma.transferred)
+				xfer_warn = 1;
+		}
+
+		/* ANSI standard says: (SCSI-2 Rev 10c Sect 5.6.6)
+		 *  Targets which break data transfers into multiple
+		 *  connections shall end each successful connection
+		 *  (except possibly the last) with a SAVE DATA
+		 *  POINTER - DISCONNECT message sequence.
+		 *
+		 * This makes it difficult to ensure that a transfer has
+		 * completed.  If we reach the end of a transfer during
+		 * the command, then we can only have finished the transfer.
+		 * therefore, if we seem to have some data remaining, this
+		 * is not a problem.
+		 */
+		if (host->dma.xfer_done)
+			xfer_warn = 0;
+
+		if (xfer_warn) {
+		    switch (status_byte(SCpnt->result)) {
+		    case CHECK_CONDITION:
+		    case COMMAND_TERMINATED:
+		    case BUSY:
+		    case QUEUE_FULL:
+		    case RESERVATION_CONFLICT:
+			break;
+
+		    default:
+			scmd_printk(KERN_ERR, SCpnt,
+				    "incomplete data transfer detected: "
+				    "result=%08X", SCpnt->result);
+			scsi_print_command(SCpnt);
+			acornscsi_dumpdma(host, "done");
+			acornscsi_dumplog(host, SCpnt->device->id);
+			set_host_byte(SCpnt, DID_ERROR);
+		    }
+		}
+	}
+
+	if (!SCpnt->scsi_done)
+	    panic("scsi%d.H: null scsi_done function in acornscsi_done", host->host->host_no);
+
+	clear_bit(SCpnt->device->id * 8 +
+		  (u8)(SCpnt->device->lun & 0x7), host->busyluns);
+
+	SCpnt->scsi_done(SCpnt);
+    } else
+	printk("scsi%d: null command in acornscsi_done", host->host->host_no);
+
+    host->scsi.phase = PHASE_IDLE;
+}
+
+/* ====================================================================================
+ * DMA routines
+ */
+/*
+ * Purpose  : update SCSI Data Pointer
+ * Notes    : this will only be one SG entry or less
+ */
+static
+void acornscsi_data_updateptr(AS_Host *host, struct scsi_pointer *SCp, unsigned int length)
+{
+    SCp->ptr += length;
+    SCp->this_residual -= length;
+
+    if (SCp->this_residual == 0 && next_SCp(SCp) == 0)
+	host->dma.xfer_done = 1;
+}
+
+/*
+ * Prototype: void acornscsi_data_read(AS_Host *host, char *ptr,
+ *				unsigned int start_addr, unsigned int length)
+ * Purpose  : read data from DMA RAM
+ * Params   : host - host to transfer from
+ *	      ptr  - DRAM address
+ *	      start_addr - host mem address
+ *	      length - number of bytes to transfer
+ * Notes    : this will only be one SG entry or less
+ */
+static
+void acornscsi_data_read(AS_Host *host, char *ptr,
+				 unsigned int start_addr, unsigned int length)
+{
+    extern void __acornscsi_in(void __iomem *, char *buf, int len);
+    unsigned int page, offset, len = length;
+
+    page = (start_addr >> 12);
+    offset = start_addr & ((1 << 12) - 1);
+
+    writeb((page & 0x3f) | host->card.page_reg, host->fast + PAGE_REG);
+
+    while (len > 0) {
+	unsigned int this_len;
+
+	if (len + offset > (1 << 12))
+	    this_len = (1 << 12) - offset;
+	else
+	    this_len = len;
+
+	__acornscsi_in(host->base + (offset << 1), ptr, this_len);
+
+	offset += this_len;
+	ptr += this_len;
+	len -= this_len;
+
+	if (offset == (1 << 12)) {
+	    offset = 0;
+	    page ++;
+	    writeb((page & 0x3f) | host->card.page_reg, host->fast + PAGE_REG);
+	}
+    }
+    writeb(host->card.page_reg, host->fast + PAGE_REG);
+}
+
+/*
+ * Prototype: void acornscsi_data_write(AS_Host *host, char *ptr,
+ *				unsigned int start_addr, unsigned int length)
+ * Purpose  : write data to DMA RAM
+ * Params   : host - host to transfer from
+ *	      ptr  - DRAM address
+ *	      start_addr - host mem address
+ *	      length - number of bytes to transfer
+ * Notes    : this will only be one SG entry or less
+ */
+static
+void acornscsi_data_write(AS_Host *host, char *ptr,
+				 unsigned int start_addr, unsigned int length)
+{
+    extern void __acornscsi_out(void __iomem *, char *buf, int len);
+    unsigned int page, offset, len = length;
+
+    page = (start_addr >> 12);
+    offset = start_addr & ((1 << 12) - 1);
+
+    writeb((page & 0x3f) | host->card.page_reg, host->fast + PAGE_REG);
+
+    while (len > 0) {
+	unsigned int this_len;
+
+	if (len + offset > (1 << 12))
+	    this_len = (1 << 12) - offset;
+	else
+	    this_len = len;
+
+	__acornscsi_out(host->base + (offset << 1), ptr, this_len);
+
+	offset += this_len;
+	ptr += this_len;
+	len -= this_len;
+
+	if (offset == (1 << 12)) {
+	    offset = 0;
+	    page ++;
+	    writeb((page & 0x3f) | host->card.page_reg, host->fast + PAGE_REG);
+	}
+    }
+    writeb(host->card.page_reg, host->fast + PAGE_REG);
+}
+
+/* =========================================================================================
+ * On-board DMA routines
+ */
+#ifdef USE_DMAC
+/*
+ * Prototype: void acornscsi_dmastop(AS_Host *host)
+ * Purpose  : stop all DMA
+ * Params   : host - host on which to stop DMA
+ * Notes    : This is called when leaving DATA IN/OUT phase,
+ *	      or when interface is RESET
+ */
+static inline
+void acornscsi_dma_stop(AS_Host *host)
+{
+    dmac_write(host, DMAC_MASKREG, MASK_ON);
+    dmac_clearintr(host);
+
+#if (DEBUG & DEBUG_DMA)
+    DBG(host->SCpnt, acornscsi_dumpdma(host, "stop"));
+#endif
+}
+
+/*
+ * Function: void acornscsi_dma_setup(AS_Host *host, dmadir_t direction)
+ * Purpose : setup DMA controller for data transfer
+ * Params  : host - host to setup
+ *	     direction - data transfer direction
+ * Notes   : This is called when entering DATA I/O phase, not
+ *	     while we're in a DATA I/O phase
+ */
+static
+void acornscsi_dma_setup(AS_Host *host, dmadir_t direction)
+{
+    unsigned int address, length, mode;
+
+    host->dma.direction = direction;
+
+    dmac_write(host, DMAC_MASKREG, MASK_ON);
+
+    if (direction == DMA_OUT) {
+#if (DEBUG & DEBUG_NO_WRITE)
+	if (NO_WRITE & (1 << host->SCpnt->device->id)) {
+	    printk(KERN_CRIT "scsi%d.%c: I can't handle DMA_OUT!\n",
+		    host->host->host_no, acornscsi_target(host));
+	    return;
+	}
+#endif
+	mode = DMAC_WRITE;
+    } else
+	mode = DMAC_READ;
+
+    /*
+     * Allocate some buffer space, limited to half the buffer size
+     */
+    length = min_t(unsigned int, host->scsi.SCp.this_residual, DMAC_BUFFER_SIZE / 2);
+    if (length) {
+	host->dma.start_addr = address = host->dma.free_addr;
+	host->dma.free_addr = (host->dma.free_addr + length) &
+				(DMAC_BUFFER_SIZE - 1);
+
+	/*
+	 * Transfer data to DMA memory
+	 */
+	if (direction == DMA_OUT)
+	    acornscsi_data_write(host, host->scsi.SCp.ptr, host->dma.start_addr,
+				length);
+
+	length -= 1;
+	dmac_write(host, DMAC_TXCNTLO, length);
+	dmac_write(host, DMAC_TXCNTHI, length >> 8);
+	dmac_write(host, DMAC_TXADRLO, address);
+	dmac_write(host, DMAC_TXADRMD, address >> 8);
+	dmac_write(host, DMAC_TXADRHI, 0);
+	dmac_write(host, DMAC_MODECON, mode);
+	dmac_write(host, DMAC_MASKREG, MASK_OFF);
+
+#if (DEBUG & DEBUG_DMA)
+	DBG(host->SCpnt, acornscsi_dumpdma(host, "strt"));
+#endif
+	host->dma.xfer_setup = 1;
+    }
+}
+
+/*
+ * Function: void acornscsi_dma_cleanup(AS_Host *host)
+ * Purpose : ensure that all DMA transfers are up-to-date & host->scsi.SCp is correct
+ * Params  : host - host to finish
+ * Notes   : This is called when a command is:
+ *		terminating, RESTORE_POINTERS, SAVE_POINTERS, DISCONECT
+ *	   : This must not return until all transfers are completed.
+ */
+static
+void acornscsi_dma_cleanup(AS_Host *host)
+{
+    dmac_write(host, DMAC_MASKREG, MASK_ON);
+    dmac_clearintr(host);
+
+    /*
+     * Check for a pending transfer
+     */
+    if (host->dma.xfer_required) {
+	host->dma.xfer_required = 0;
+	if (host->dma.direction == DMA_IN)
+	    acornscsi_data_read(host, host->dma.xfer_ptr,
+				 host->dma.xfer_start, host->dma.xfer_length);
+    }
+
+    /*
+     * Has a transfer been setup?
+     */
+    if (host->dma.xfer_setup) {
+	unsigned int transferred;
+
+	host->dma.xfer_setup = 0;
+
+#if (DEBUG & DEBUG_DMA)
+	DBG(host->SCpnt, acornscsi_dumpdma(host, "cupi"));
+#endif
+
+	/*
+	 * Calculate number of bytes transferred from DMA.
+	 */
+	transferred = dmac_address(host) - host->dma.start_addr;
+	host->dma.transferred += transferred;
+
+	if (host->dma.direction == DMA_IN)
+	    acornscsi_data_read(host, host->scsi.SCp.ptr,
+				 host->dma.start_addr, transferred);
+
+	/*
+	 * Update SCSI pointers
+	 */
+	acornscsi_data_updateptr(host, &host->scsi.SCp, transferred);
+#if (DEBUG & DEBUG_DMA)
+	DBG(host->SCpnt, acornscsi_dumpdma(host, "cupo"));
+#endif
+    }
+}
+
+/*
+ * Function: void acornscsi_dmacintr(AS_Host *host)
+ * Purpose : handle interrupts from DMAC device
+ * Params  : host - host to process
+ * Notes   : If reading, we schedule the read to main memory &
+ *	     allow the transfer to continue.
+ *	   : If writing, we fill the onboard DMA memory from main
+ *	     memory.
+ *	   : Called whenever DMAC finished it's current transfer.
+ */
+static
+void acornscsi_dma_intr(AS_Host *host)
+{
+    unsigned int address, length, transferred;
+
+#if (DEBUG & DEBUG_DMA)
+    DBG(host->SCpnt, acornscsi_dumpdma(host, "inti"));
+#endif
+
+    dmac_write(host, DMAC_MASKREG, MASK_ON);
+    dmac_clearintr(host);
+
+    /*
+     * Calculate amount transferred via DMA
+     */
+    transferred = dmac_address(host) - host->dma.start_addr;
+    host->dma.transferred += transferred;
+
+    /*
+     * Schedule DMA transfer off board
+     */
+    if (host->dma.direction == DMA_IN) {
+	host->dma.xfer_start = host->dma.start_addr;
+	host->dma.xfer_length = transferred;
+	host->dma.xfer_ptr = host->scsi.SCp.ptr;
+	host->dma.xfer_required = 1;
+    }
+
+    acornscsi_data_updateptr(host, &host->scsi.SCp, transferred);
+
+    /*
+     * Allocate some buffer space, limited to half the on-board RAM size
+     */
+    length = min_t(unsigned int, host->scsi.SCp.this_residual, DMAC_BUFFER_SIZE / 2);
+    if (length) {
+	host->dma.start_addr = address = host->dma.free_addr;
+	host->dma.free_addr = (host->dma.free_addr + length) &
+				(DMAC_BUFFER_SIZE - 1);
+
+	/*
+	 * Transfer data to DMA memory
+	 */
+	if (host->dma.direction == DMA_OUT)
+	    acornscsi_data_write(host, host->scsi.SCp.ptr, host->dma.start_addr,
+				length);
+
+	length -= 1;
+	dmac_write(host, DMAC_TXCNTLO, length);
+	dmac_write(host, DMAC_TXCNTHI, length >> 8);
+	dmac_write(host, DMAC_TXADRLO, address);
+	dmac_write(host, DMAC_TXADRMD, address >> 8);
+	dmac_write(host, DMAC_TXADRHI, 0);
+	dmac_write(host, DMAC_MASKREG, MASK_OFF);
+
+#if (DEBUG & DEBUG_DMA)
+	DBG(host->SCpnt, acornscsi_dumpdma(host, "into"));
+#endif
+    } else {
+	host->dma.xfer_setup = 0;
+#if 0
+	/*
+	 * If the interface still wants more, then this is an error.
+	 * We give it another byte, but we also attempt to raise an
+	 * attention condition.  We continue giving one byte until
+	 * the device recognises the attention.
+	 */
+	if (dmac_read(host, DMAC_STATUS) & STATUS_RQ0) {
+	    acornscsi_abortcmd(host, host->SCpnt->tag);
+
+	    dmac_write(host, DMAC_TXCNTLO, 0);
+	    dmac_write(host, DMAC_TXCNTHI, 0);
+	    dmac_write(host, DMAC_TXADRLO, 0);
+	    dmac_write(host, DMAC_TXADRMD, 0);
+	    dmac_write(host, DMAC_TXADRHI, 0);
+	    dmac_write(host, DMAC_MASKREG, MASK_OFF);
+	}
+#endif
+    }
+}
+
+/*
+ * Function: void acornscsi_dma_xfer(AS_Host *host)
+ * Purpose : transfer data between AcornSCSI and memory
+ * Params  : host - host to process
+ */
+static
+void acornscsi_dma_xfer(AS_Host *host)
+{
+    host->dma.xfer_required = 0;
+
+    if (host->dma.direction == DMA_IN)
+	acornscsi_data_read(host, host->dma.xfer_ptr,
+				host->dma.xfer_start, host->dma.xfer_length);
+}
+
+/*
+ * Function: void acornscsi_dma_adjust(AS_Host *host)
+ * Purpose : adjust DMA pointers & count for bytes transferred to
+ *	     SBIC but not SCSI bus.
+ * Params  : host - host to adjust DMA count for
+ */
+static
+void acornscsi_dma_adjust(AS_Host *host)
+{
+    if (host->dma.xfer_setup) {
+	signed long transferred;
+#if (DEBUG & (DEBUG_DMA|DEBUG_WRITE))
+	DBG(host->SCpnt, acornscsi_dumpdma(host, "adji"));
+#endif
+	/*
+	 * Calculate correct DMA address - DMA is ahead of SCSI bus while
+	 * writing.
+	 *  host->scsi.SCp.scsi_xferred is the number of bytes
+	 *  actually transferred to/from the SCSI bus.
+	 *  host->dma.transferred is the number of bytes transferred
+	 *  over DMA since host->dma.start_addr was last set.
+	 *
+	 * real_dma_addr = host->dma.start_addr + host->scsi.SCp.scsi_xferred
+	 *		   - host->dma.transferred
+	 */
+	transferred = host->scsi.SCp.scsi_xferred - host->dma.transferred;
+	if (transferred < 0)
+	    printk("scsi%d.%c: Ack! DMA write correction %ld < 0!\n",
+		    host->host->host_no, acornscsi_target(host), transferred);
+	else if (transferred == 0)
+	    host->dma.xfer_setup = 0;
+	else {
+	    transferred += host->dma.start_addr;
+	    dmac_write(host, DMAC_TXADRLO, transferred);
+	    dmac_write(host, DMAC_TXADRMD, transferred >> 8);
+	    dmac_write(host, DMAC_TXADRHI, transferred >> 16);
+#if (DEBUG & (DEBUG_DMA|DEBUG_WRITE))
+	    DBG(host->SCpnt, acornscsi_dumpdma(host, "adjo"));
+#endif
+	}
+    }
+}
+#endif
+
+/* =========================================================================================
+ * Data I/O
+ */
+static int
+acornscsi_write_pio(AS_Host *host, char *bytes, int *ptr, int len, unsigned int max_timeout)
+{
+	unsigned int asr, timeout = max_timeout;
+	int my_ptr = *ptr;
+
+	while (my_ptr < len) {
+		asr = sbic_arm_read(host, SBIC_ASR);
+
+		if (asr & ASR_DBR) {
+			timeout = max_timeout;
+
+			sbic_arm_write(host, SBIC_DATA, bytes[my_ptr++]);
+		} else if (asr & ASR_INT)
+			break;
+		else if (--timeout == 0)
+			break;
+		udelay(1);
+	}
+
+	*ptr = my_ptr;
+
+	return (timeout == 0) ? -1 : 0;
+}
+
+/*
+ * Function: void acornscsi_sendcommand(AS_Host *host)
+ * Purpose : send a command to a target
+ * Params  : host - host which is connected to target
+ */
+static void
+acornscsi_sendcommand(AS_Host *host)
+{
+	struct scsi_cmnd *SCpnt = host->SCpnt;
+
+    sbic_arm_write(host, SBIC_TRANSCNTH, 0);
+    sbic_arm_writenext(host, 0);
+    sbic_arm_writenext(host, SCpnt->cmd_len - host->scsi.SCp.sent_command);
+
+    acornscsi_sbic_issuecmd(host, CMND_XFERINFO);
+
+    if (acornscsi_write_pio(host, SCpnt->cmnd,
+	(int *)&host->scsi.SCp.sent_command, SCpnt->cmd_len, 1000000))
+	printk("scsi%d: timeout while sending command\n", host->host->host_no);
+
+    host->scsi.phase = PHASE_COMMAND;
+}
+
+static
+void acornscsi_sendmessage(AS_Host *host)
+{
+    unsigned int message_length = msgqueue_msglength(&host->scsi.msgs);
+    unsigned int msgnr;
+    struct message *msg;
+
+#if (DEBUG & DEBUG_MESSAGES)
+    printk("scsi%d.%c: sending message ",
+	    host->host->host_no, acornscsi_target(host));
+#endif
+
+    switch (message_length) {
+    case 0:
+	acornscsi_sbic_issuecmd(host, CMND_XFERINFO | CMND_SBT);
+
+	acornscsi_sbic_wait(host, ASR_DBR, ASR_DBR, 1000, "sending message 1");
+
+	sbic_arm_write(host, SBIC_DATA, NOP);
+
+	host->scsi.last_message = NOP;
+#if (DEBUG & DEBUG_MESSAGES)
+	printk("NOP");
+#endif
+	break;
+
+    case 1:
+	acornscsi_sbic_issuecmd(host, CMND_XFERINFO | CMND_SBT);
+	msg = msgqueue_getmsg(&host->scsi.msgs, 0);
+
+	acornscsi_sbic_wait(host, ASR_DBR, ASR_DBR, 1000, "sending message 2");
+
+	sbic_arm_write(host, SBIC_DATA, msg->msg[0]);
+
+	host->scsi.last_message = msg->msg[0];
+#if (DEBUG & DEBUG_MESSAGES)
+	spi_print_msg(msg->msg);
+#endif
+	break;
+
+    default:
+	/*
+	 * ANSI standard says: (SCSI-2 Rev 10c Sect 5.6.14)
+	 * 'When a target sends this (MESSAGE_REJECT) message, it
+	 *  shall change to MESSAGE IN phase and send this message
+	 *  prior to requesting additional message bytes from the
+	 *  initiator.  This provides an interlock so that the
+	 *  initiator can determine which message byte is rejected.
+	 */
+	sbic_arm_write(host, SBIC_TRANSCNTH, 0);
+	sbic_arm_writenext(host, 0);
+	sbic_arm_writenext(host, message_length);
+	acornscsi_sbic_issuecmd(host, CMND_XFERINFO);
+
+	msgnr = 0;
+	while ((msg = msgqueue_getmsg(&host->scsi.msgs, msgnr++)) != NULL) {
+	    unsigned int i;
+#if (DEBUG & DEBUG_MESSAGES)
+	    spi_print_msg(msg);
+#endif
+	    i = 0;
+	    if (acornscsi_write_pio(host, msg->msg, &i, msg->length, 1000000))
+		printk("scsi%d: timeout while sending message\n", host->host->host_no);
+
+	    host->scsi.last_message = msg->msg[0];
+	    if (msg->msg[0] == EXTENDED_MESSAGE)
+		host->scsi.last_message |= msg->msg[2] << 8;
+
+	    if (i != msg->length)
+		break;
+	}
+	break;
+    }
+#if (DEBUG & DEBUG_MESSAGES)
+    printk("\n");
+#endif
+}
+
+/*
+ * Function: void acornscsi_readstatusbyte(AS_Host *host)
+ * Purpose : Read status byte from connected target
+ * Params  : host - host connected to target
+ */
+static
+void acornscsi_readstatusbyte(AS_Host *host)
+{
+    acornscsi_sbic_issuecmd(host, CMND_XFERINFO|CMND_SBT);
+    acornscsi_sbic_wait(host, ASR_DBR, ASR_DBR, 1000, "reading status byte");
+    host->scsi.SCp.Status = sbic_arm_read(host, SBIC_DATA);
+}
+
+/*
+ * Function: unsigned char acornscsi_readmessagebyte(AS_Host *host)
+ * Purpose : Read one message byte from connected target
+ * Params  : host - host connected to target
+ */
+static
+unsigned char acornscsi_readmessagebyte(AS_Host *host)
+{
+    unsigned char message;
+
+    acornscsi_sbic_issuecmd(host, CMND_XFERINFO | CMND_SBT);
+
+    acornscsi_sbic_wait(host, ASR_DBR, ASR_DBR, 1000, "for message byte");
+
+    message = sbic_arm_read(host, SBIC_DATA);
+
+    /* wait for MSGIN-XFER-PAUSED */
+    acornscsi_sbic_wait(host, ASR_INT, ASR_INT, 1000, "for interrupt after message byte");
+
+    sbic_arm_read(host, SBIC_SSR);
+
+    return message;
+}
+
+/*
+ * Function: void acornscsi_message(AS_Host *host)
+ * Purpose : Read complete message from connected target & action message
+ * Params  : host - host connected to target
+ */
+static
+void acornscsi_message(AS_Host *host)
+{
+    unsigned char message[16];
+    unsigned int msgidx = 0, msglen = 1;
+
+    do {
+	message[msgidx] = acornscsi_readmessagebyte(host);
+
+	switch (msgidx) {
+	case 0:
+	    if (message[0] == EXTENDED_MESSAGE ||
+		(message[0] >= 0x20 && message[0] <= 0x2f))
+		msglen = 2;
+	    break;
+
+	case 1:
+	    if (message[0] == EXTENDED_MESSAGE)
+		msglen += message[msgidx];
+	    break;
+	}
+	msgidx += 1;
+	if (msgidx < msglen) {
+	    acornscsi_sbic_issuecmd(host, CMND_NEGATEACK);
+
+	    /* wait for next msg-in */
+	    acornscsi_sbic_wait(host, ASR_INT, ASR_INT, 1000, "for interrupt after negate ack");
+	    sbic_arm_read(host, SBIC_SSR);
+	}
+    } while (msgidx < msglen);
+
+#if (DEBUG & DEBUG_MESSAGES)
+    printk("scsi%d.%c: message in: ",
+	    host->host->host_no, acornscsi_target(host));
+    spi_print_msg(message);
+    printk("\n");
+#endif
+
+    if (host->scsi.phase == PHASE_RECONNECTED) {
+	/*
+	 * ANSI standard says: (Section SCSI-2 Rev. 10c Sect 5.6.17)
+	 * 'Whenever a target reconnects to an initiator to continue
+	 *  a tagged I/O process, the SIMPLE QUEUE TAG message shall
+	 *  be sent immediately following the IDENTIFY message...'
+	 */
+	if (message[0] == SIMPLE_QUEUE_TAG)
+	    host->scsi.reconnected.tag = message[1];
+	if (acornscsi_reconnect_finish(host))
+	    host->scsi.phase = PHASE_MSGIN;
+    }
+
+    switch (message[0]) {
+    case ABORT:
+    case ABORT_TAG:
+    case COMMAND_COMPLETE:
+	if (host->scsi.phase != PHASE_STATUSIN) {
+	    printk(KERN_ERR "scsi%d.%c: command complete following non-status in phase?\n",
+		    host->host->host_no, acornscsi_target(host));
+	    acornscsi_dumplog(host, host->SCpnt->device->id);
+	}
+	host->scsi.phase = PHASE_DONE;
+	host->scsi.SCp.Message = message[0];
+	break;
+
+    case SAVE_POINTERS:
+	/*
+	 * ANSI standard says: (Section SCSI-2 Rev. 10c Sect 5.6.20)
+	 * 'The SAVE DATA POINTER message is sent from a target to
+	 *  direct the initiator to copy the active data pointer to
+	 *  the saved data pointer for the current I/O process.
+	 */
+	acornscsi_dma_cleanup(host);
+	host->SCpnt->SCp = host->scsi.SCp;
+	host->SCpnt->SCp.sent_command = 0;
+	host->scsi.phase = PHASE_MSGIN;
+	break;
+
+    case RESTORE_POINTERS:
+	/*
+	 * ANSI standard says: (Section SCSI-2 Rev. 10c Sect 5.6.19)
+	 * 'The RESTORE POINTERS message is sent from a target to
+	 *  direct the initiator to copy the most recently saved
+	 *  command, data, and status pointers for the I/O process
+	 *  to the corresponding active pointers.  The command and
+	 *  status pointers shall be restored to the beginning of
+	 *  the present command and status areas.'
+	 */
+	acornscsi_dma_cleanup(host);
+	host->scsi.SCp = host->SCpnt->SCp;
+	host->scsi.phase = PHASE_MSGIN;
+	break;
+
+    case DISCONNECT:
+	/*
+	 * ANSI standard says: (Section SCSI-2 Rev. 10c Sect 6.4.2)
+	 * 'On those occasions when an error or exception condition occurs
+	 *  and the target elects to repeat the information transfer, the
+	 *  target may repeat the transfer either issuing a RESTORE POINTERS
+	 *  message or by disconnecting without issuing a SAVE POINTERS
+	 *  message.  When reconnection is completed, the most recent
+	 *  saved pointer values are restored.'
+	 */
+	acornscsi_dma_cleanup(host);
+	host->scsi.phase = PHASE_DISCONNECT;
+	break;
+
+    case MESSAGE_REJECT:
+#if 0 /* this isn't needed any more */
+	/*
+	 * If we were negociating sync transfer, we don't yet know if
+	 * this REJECT is for the sync transfer or for the tagged queue/wide
+	 * transfer.  Re-initiate sync transfer negotiation now, and if
+	 * we got a REJECT in response to SDTR, then it'll be set to DONE.
+	 */
+	if (host->device[host->SCpnt->device->id].sync_state == SYNC_SENT_REQUEST)
+	    host->device[host->SCpnt->device->id].sync_state = SYNC_NEGOCIATE;
+#endif
+
+	/*
+	 * If we have any messages waiting to go out, then assert ATN now
+	 */
+	if (msgqueue_msglength(&host->scsi.msgs))
+	    acornscsi_sbic_issuecmd(host, CMND_ASSERTATN);
+
+	switch (host->scsi.last_message) {
+#ifdef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
+	case HEAD_OF_QUEUE_TAG:
+	case ORDERED_QUEUE_TAG:
+	case SIMPLE_QUEUE_TAG:
+	    /*
+	     * ANSI standard says: (Section SCSI-2 Rev. 10c Sect 5.6.17)
+	     *  If a target does not implement tagged queuing and a queue tag
+	     *  message is received, it shall respond with a MESSAGE REJECT
+	     *  message and accept the I/O process as if it were untagged.
+	     */
+	    printk(KERN_NOTICE "scsi%d.%c: disabling tagged queueing\n",
+		    host->host->host_no, acornscsi_target(host));
+	    host->SCpnt->device->simple_tags = 0;
+	    set_bit(host->SCpnt->device->id * 8 +
+		    (u8)(host->SCpnt->device->lun & 0x7), host->busyluns);
+	    break;
+#endif
+	case EXTENDED_MESSAGE | (EXTENDED_SDTR << 8):
+	    /*
+	     * Target can't handle synchronous transfers
+	     */
+	    printk(KERN_NOTICE "scsi%d.%c: Using asynchronous transfer\n",
+		    host->host->host_no, acornscsi_target(host));
+	    host->device[host->SCpnt->device->id].sync_xfer = SYNCHTRANSFER_2DBA;
+	    host->device[host->SCpnt->device->id].sync_state = SYNC_ASYNCHRONOUS;
+	    sbic_arm_write(host, SBIC_SYNCHTRANSFER, host->device[host->SCpnt->device->id].sync_xfer);
+	    break;
+
+	default:
+	    break;
+	}
+	break;
+
+    case QUEUE_FULL:
+	/* TODO: target queue is full */
+	break;
+
+    case SIMPLE_QUEUE_TAG:
+	/* tag queue reconnect... message[1] = queue tag.  Print something to indicate something happened! */
+	printk("scsi%d.%c: reconnect queue tag %02X\n",
+		host->host->host_no, acornscsi_target(host),
+		message[1]);
+	break;
+
+    case EXTENDED_MESSAGE:
+	switch (message[2]) {
+#ifdef CONFIG_SCSI_ACORNSCSI_SYNC
+	case EXTENDED_SDTR:
+	    if (host->device[host->SCpnt->device->id].sync_state == SYNC_SENT_REQUEST) {
+		/*
+		 * We requested synchronous transfers.  This isn't quite right...
+		 * We can only say if this succeeded if we proceed on to execute the
+		 * command from this message.  If we get a MESSAGE PARITY ERROR,
+		 * and the target retries fail, then we fallback to asynchronous mode
+		 */
+		host->device[host->SCpnt->device->id].sync_state = SYNC_COMPLETED;
+		printk(KERN_NOTICE "scsi%d.%c: Using synchronous transfer, offset %d, %d ns\n",
+			host->host->host_no, acornscsi_target(host),
+			message[4], message[3] * 4);
+		host->device[host->SCpnt->device->id].sync_xfer =
+			calc_sync_xfer(message[3] * 4, message[4]);
+	    } else {
+		unsigned char period, length;
+		/*
+		 * Target requested synchronous transfers.  The agreement is only
+		 * to be in operation AFTER the target leaves message out phase.
+		 */
+		acornscsi_sbic_issuecmd(host, CMND_ASSERTATN);
+		period = max_t(unsigned int, message[3], sdtr_period / 4);
+		length = min_t(unsigned int, message[4], sdtr_size);
+		msgqueue_addmsg(&host->scsi.msgs, 5, EXTENDED_MESSAGE, 3,
+				 EXTENDED_SDTR, period, length);
+		host->device[host->SCpnt->device->id].sync_xfer =
+			calc_sync_xfer(period * 4, length);
+	    }
+	    sbic_arm_write(host, SBIC_SYNCHTRANSFER, host->device[host->SCpnt->device->id].sync_xfer);
+	    break;
+#else
+	    /* We do not accept synchronous transfers.  Respond with a
+	     * MESSAGE_REJECT.
+	     */
+#endif
+
+	case EXTENDED_WDTR:
+	    /* The WD33C93A is only 8-bit.  We respond with a MESSAGE_REJECT
+	     * to a wide data transfer request.
+	     */
+	default:
+	    acornscsi_sbic_issuecmd(host, CMND_ASSERTATN);
+	    msgqueue_flush(&host->scsi.msgs);
+	    msgqueue_addmsg(&host->scsi.msgs, 1, MESSAGE_REJECT);
+	    break;
+	}
+	break;
+
+    default: /* reject message */
+	printk(KERN_ERR "scsi%d.%c: unrecognised message %02X, rejecting\n",
+		host->host->host_no, acornscsi_target(host),
+		message[0]);
+	acornscsi_sbic_issuecmd(host, CMND_ASSERTATN);
+	msgqueue_flush(&host->scsi.msgs);
+	msgqueue_addmsg(&host->scsi.msgs, 1, MESSAGE_REJECT);
+	host->scsi.phase = PHASE_MSGIN;
+	break;
+    }
+    acornscsi_sbic_issuecmd(host, CMND_NEGATEACK);
+}
+
+/*
+ * Function: int acornscsi_buildmessages(AS_Host *host)
+ * Purpose : build the connection messages for a host
+ * Params  : host - host to add messages to
+ */
+static
+void acornscsi_buildmessages(AS_Host *host)
+{
+#if 0
+    /* does the device need resetting? */
+    if (cmd_reset) {
+	msgqueue_addmsg(&host->scsi.msgs, 1, BUS_DEVICE_RESET);
+	return;
+    }
+#endif
+
+    msgqueue_addmsg(&host->scsi.msgs, 1,
+		     IDENTIFY(host->device[host->SCpnt->device->id].disconnect_ok,
+			     host->SCpnt->device->lun));
+
+#if 0
+    /* does the device need the current command aborted */
+    if (cmd_aborted) {
+	acornscsi_abortcmd(host->SCpnt->tag);
+	return;
+    }
+#endif
+
+#ifdef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
+    if (host->SCpnt->tag) {
+	unsigned int tag_type;
+
+	if (host->SCpnt->cmnd[0] == REQUEST_SENSE ||
+	    host->SCpnt->cmnd[0] == TEST_UNIT_READY ||
+	    host->SCpnt->cmnd[0] == INQUIRY)
+	    tag_type = HEAD_OF_QUEUE_TAG;
+	else
+	    tag_type = SIMPLE_QUEUE_TAG;
+	msgqueue_addmsg(&host->scsi.msgs, 2, tag_type, host->SCpnt->tag);
+    }
+#endif
+
+#ifdef CONFIG_SCSI_ACORNSCSI_SYNC
+    if (host->device[host->SCpnt->device->id].sync_state == SYNC_NEGOCIATE) {
+	host->device[host->SCpnt->device->id].sync_state = SYNC_SENT_REQUEST;
+	msgqueue_addmsg(&host->scsi.msgs, 5,
+			 EXTENDED_MESSAGE, 3, EXTENDED_SDTR,
+			 sdtr_period / 4, sdtr_size);
+    }
+#endif
+}
+
+/*
+ * Function: int acornscsi_starttransfer(AS_Host *host)
+ * Purpose : transfer data to/from connected target
+ * Params  : host - host to which target is connected
+ * Returns : 0 if failure
+ */
+static
+int acornscsi_starttransfer(AS_Host *host)
+{
+    int residual;
+
+    if (!host->scsi.SCp.ptr /*&& host->scsi.SCp.this_residual*/) {
+	printk(KERN_ERR "scsi%d.%c: null buffer passed to acornscsi_starttransfer\n",
+		host->host->host_no, acornscsi_target(host));
+	return 0;
+    }
+
+    residual = scsi_bufflen(host->SCpnt) - host->scsi.SCp.scsi_xferred;
+
+    sbic_arm_write(host, SBIC_SYNCHTRANSFER, host->device[host->SCpnt->device->id].sync_xfer);
+    sbic_arm_writenext(host, residual >> 16);
+    sbic_arm_writenext(host, residual >> 8);
+    sbic_arm_writenext(host, residual);
+    acornscsi_sbic_issuecmd(host, CMND_XFERINFO);
+    return 1;
+}
+
+/* =========================================================================================
+ * Connection & Disconnection
+ */
+/*
+ * Function : acornscsi_reconnect(AS_Host *host)
+ * Purpose  : reconnect a previously disconnected command
+ * Params   : host - host specific data
+ * Remarks  : SCSI spec says:
+ *		'The set of active pointers is restored from the set
+ *		 of saved pointers upon reconnection of the I/O process'
+ */
+static
+int acornscsi_reconnect(AS_Host *host)
+{
+    unsigned int target, lun, ok = 0;
+
+    target = sbic_arm_read(host, SBIC_SOURCEID);
+
+    if (!(target & 8))
+	printk(KERN_ERR "scsi%d: invalid source id after reselection "
+		"- device fault?\n",
+		host->host->host_no);
+
+    target &= 7;
+
+    if (host->SCpnt && !host->scsi.disconnectable) {
+	printk(KERN_ERR "scsi%d.%d: reconnected while command in "
+		"progress to target %d?\n",
+		host->host->host_no, target, host->SCpnt->device->id);
+	host->SCpnt = NULL;
+    }
+
+    lun = sbic_arm_read(host, SBIC_DATA) & 7;
+
+    host->scsi.reconnected.target = target;
+    host->scsi.reconnected.lun = lun;
+    host->scsi.reconnected.tag = 0;
+
+    if (host->scsi.disconnectable && host->SCpnt &&
+	host->SCpnt->device->id == target && host->SCpnt->device->lun == lun)
+	ok = 1;
+
+    if (!ok && queue_probetgtlun(&host->queues.disconnected, target, lun))
+	ok = 1;
+
+    ADD_STATUS(target, 0x81, host->scsi.phase, 0);
+
+    if (ok) {
+	host->scsi.phase = PHASE_RECONNECTED;
+    } else {
+	/* this doesn't seem to work */
+	printk(KERN_ERR "scsi%d.%c: reselected with no command "
+		"to reconnect with\n",
+		host->host->host_no, '0' + target);
+	acornscsi_dumplog(host, target);
+	acornscsi_abortcmd(host, 0);
+	if (host->SCpnt) {
+	    queue_add_cmd_tail(&host->queues.disconnected, host->SCpnt);
+	    host->SCpnt = NULL;
+	}
+    }
+    acornscsi_sbic_issuecmd(host, CMND_NEGATEACK);
+    return !ok;
+}
+
+/*
+ * Function: int acornscsi_reconect_finish(AS_Host *host)
+ * Purpose : finish reconnecting a command
+ * Params  : host - host to complete
+ * Returns : 0 if failed
+ */
+static
+int acornscsi_reconnect_finish(AS_Host *host)
+{
+    if (host->scsi.disconnectable && host->SCpnt) {
+	host->scsi.disconnectable = 0;
+	if (host->SCpnt->device->id  == host->scsi.reconnected.target &&
+	    host->SCpnt->device->lun == host->scsi.reconnected.lun &&
+	    host->SCpnt->tag         == host->scsi.reconnected.tag) {
+#if (DEBUG & (DEBUG_QUEUES|DEBUG_DISCON))
+	    DBG(host->SCpnt, printk("scsi%d.%c: reconnected",
+		    host->host->host_no, acornscsi_target(host)));
+#endif
+	} else {
+	    queue_add_cmd_tail(&host->queues.disconnected, host->SCpnt);
+#if (DEBUG & (DEBUG_QUEUES|DEBUG_DISCON))
+	    DBG(host->SCpnt, printk("scsi%d.%c: had to move command "
+		    "to disconnected queue\n",
+		    host->host->host_no, acornscsi_target(host)));
+#endif
+	    host->SCpnt = NULL;
+	}
+    }
+    if (!host->SCpnt) {
+	host->SCpnt = queue_remove_tgtluntag(&host->queues.disconnected,
+				host->scsi.reconnected.target,
+				host->scsi.reconnected.lun,
+				host->scsi.reconnected.tag);
+#if (DEBUG & (DEBUG_QUEUES|DEBUG_DISCON))
+	DBG(host->SCpnt, printk("scsi%d.%c: had to get command",
+		host->host->host_no, acornscsi_target(host)));
+#endif
+    }
+
+    if (!host->SCpnt)
+	acornscsi_abortcmd(host, host->scsi.reconnected.tag);
+    else {
+	/*
+	 * Restore data pointer from SAVED pointers.
+	 */
+	host->scsi.SCp = host->SCpnt->SCp;
+#if (DEBUG & (DEBUG_QUEUES|DEBUG_DISCON))
+	printk(", data pointers: [%p, %X]",
+		host->scsi.SCp.ptr, host->scsi.SCp.this_residual);
+#endif
+    }
+#if (DEBUG & (DEBUG_QUEUES|DEBUG_DISCON))
+    printk("\n");
+#endif
+
+    host->dma.transferred = host->scsi.SCp.scsi_xferred;
+
+    return host->SCpnt != NULL;
+}
+
+/*
+ * Function: void acornscsi_disconnect_unexpected(AS_Host *host)
+ * Purpose : handle an unexpected disconnect
+ * Params  : host - host on which disconnect occurred
+ */
+static
+void acornscsi_disconnect_unexpected(AS_Host *host)
+{
+    printk(KERN_ERR "scsi%d.%c: unexpected disconnect\n",
+	    host->host->host_no, acornscsi_target(host));
+#if (DEBUG & DEBUG_ABORT)
+    acornscsi_dumplog(host, 8);
+#endif
+
+    acornscsi_done(host, &host->SCpnt, DID_ERROR);
+}
+
+/*
+ * Function: void acornscsi_abortcmd(AS_host *host, unsigned char tag)
+ * Purpose : abort a currently executing command
+ * Params  : host - host with connected command to abort
+ *	     tag  - tag to abort
+ */
+static
+void acornscsi_abortcmd(AS_Host *host, unsigned char tag)
+{
+    host->scsi.phase = PHASE_ABORTED;
+    sbic_arm_write(host, SBIC_CMND, CMND_ASSERTATN);
+
+    msgqueue_flush(&host->scsi.msgs);
+#ifdef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
+    if (tag)
+	msgqueue_addmsg(&host->scsi.msgs, 2, ABORT_TAG, tag);
+    else
+#endif
+	msgqueue_addmsg(&host->scsi.msgs, 1, ABORT);
+}
+
+/* ==========================================================================================
+ * Interrupt routines.
+ */
+/*
+ * Function: int acornscsi_sbicintr(AS_Host *host)
+ * Purpose : handle interrupts from SCSI device
+ * Params  : host - host to process
+ * Returns : INTR_PROCESS if expecting another SBIC interrupt
+ *	     INTR_IDLE if no interrupt
+ *	     INTR_NEXT_COMMAND if we have finished processing the command
+ */
+static
+intr_ret_t acornscsi_sbicintr(AS_Host *host, int in_irq)
+{
+    unsigned int asr, ssr;
+
+    asr = sbic_arm_read(host, SBIC_ASR);
+    if (!(asr & ASR_INT))
+	return INTR_IDLE;
+
+    ssr = sbic_arm_read(host, SBIC_SSR);
+
+#if (DEBUG & DEBUG_PHASES)
+    print_sbic_status(asr, ssr, host->scsi.phase);
+#endif
+
+    ADD_STATUS(8, ssr, host->scsi.phase, in_irq);
+
+    if (host->SCpnt && !host->scsi.disconnectable)
+	ADD_STATUS(host->SCpnt->device->id, ssr, host->scsi.phase, in_irq);
+
+    switch (ssr) {
+    case 0x00:				/* reset state - not advanced			*/
+	printk(KERN_ERR "scsi%d: reset in standard mode but wanted advanced mode.\n",
+		host->host->host_no);
+	/* setup sbic - WD33C93A */
+	sbic_arm_write(host, SBIC_OWNID, OWNID_EAF | host->host->this_id);
+	sbic_arm_write(host, SBIC_CMND, CMND_RESET);
+	return INTR_IDLE;
+
+    case 0x01:				/* reset state - advanced			*/
+	sbic_arm_write(host, SBIC_CTRL, INIT_SBICDMA | CTRL_IDI);
+	sbic_arm_write(host, SBIC_TIMEOUT, TIMEOUT_TIME);
+	sbic_arm_write(host, SBIC_SYNCHTRANSFER, SYNCHTRANSFER_2DBA);
+	sbic_arm_write(host, SBIC_SOURCEID, SOURCEID_ER | SOURCEID_DSP);
+	msgqueue_flush(&host->scsi.msgs);
+	return INTR_IDLE;
+
+    case 0x41:				/* unexpected disconnect aborted command	*/
+	acornscsi_disconnect_unexpected(host);
+	return INTR_NEXT_COMMAND;
+    }
+
+    switch (host->scsi.phase) {
+    case PHASE_CONNECTING:		/* STATE: command removed from issue queue	*/
+	switch (ssr) {
+	case 0x11:			/* -> PHASE_CONNECTED				*/
+	    /* BUS FREE -> SELECTION */
+	    host->scsi.phase = PHASE_CONNECTED;
+	    msgqueue_flush(&host->scsi.msgs);
+	    host->dma.transferred = host->scsi.SCp.scsi_xferred;
+	    /* 33C93 gives next interrupt indicating bus phase */
+	    asr = sbic_arm_read(host, SBIC_ASR);
+	    if (!(asr & ASR_INT))
+		break;
+	    ssr = sbic_arm_read(host, SBIC_SSR);
+	    ADD_STATUS(8, ssr, host->scsi.phase, 1);
+	    ADD_STATUS(host->SCpnt->device->id, ssr, host->scsi.phase, 1);
+	    goto connected;
+	    
+	case 0x42:			/* select timed out				*/
+					/* -> PHASE_IDLE				*/
+	    acornscsi_done(host, &host->SCpnt, DID_NO_CONNECT);
+	    return INTR_NEXT_COMMAND;
+
+	case 0x81:			/* -> PHASE_RECONNECTED or PHASE_ABORTED	*/
+	    /* BUS FREE -> RESELECTION */
+	    host->origSCpnt = host->SCpnt;
+	    host->SCpnt = NULL;
+	    msgqueue_flush(&host->scsi.msgs);
+	    acornscsi_reconnect(host);
+	    break;
+
+	default:
+	    printk(KERN_ERR "scsi%d.%c: PHASE_CONNECTING, SSR %02X?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	    acornscsi_abortcmd(host, host->SCpnt->tag);
+	}
+	return INTR_PROCESSING;
+
+    connected:
+    case PHASE_CONNECTED:		/* STATE: device selected ok			*/
+	switch (ssr) {
+#ifdef NONSTANDARD
+	case 0x8a:			/* -> PHASE_COMMAND, PHASE_COMMANDPAUSED	*/
+	    /* SELECTION -> COMMAND */
+	    acornscsi_sendcommand(host);
+	    break;
+
+	case 0x8b:			/* -> PHASE_STATUS				*/
+	    /* SELECTION -> STATUS */
+	    acornscsi_readstatusbyte(host);
+	    host->scsi.phase = PHASE_STATUSIN;
+	    break;
+#endif
+
+	case 0x8e:			/* -> PHASE_MSGOUT				*/
+	    /* SELECTION ->MESSAGE OUT */
+	    host->scsi.phase = PHASE_MSGOUT;
+	    acornscsi_buildmessages(host);
+	    acornscsi_sendmessage(host);
+	    break;
+
+	/* these should not happen */
+	case 0x85:			/* target disconnected				*/
+	    acornscsi_done(host, &host->SCpnt, DID_ERROR);
+	    break;
+
+	default:
+	    printk(KERN_ERR "scsi%d.%c: PHASE_CONNECTED, SSR %02X?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	    acornscsi_abortcmd(host, host->SCpnt->tag);
+	}
+	return INTR_PROCESSING;
+
+    case PHASE_MSGOUT:			/* STATE: connected & sent IDENTIFY message	*/
+	/*
+	 * SCSI standard says that MESSAGE OUT phases can be followed by a
+	 * DATA phase, STATUS phase, MESSAGE IN phase or COMMAND phase
+	 */
+	switch (ssr) {
+	case 0x8a:			/* -> PHASE_COMMAND, PHASE_COMMANDPAUSED	*/
+	case 0x1a:			/* -> PHASE_COMMAND, PHASE_COMMANDPAUSED	*/
+	    /* MESSAGE OUT -> COMMAND */
+	    acornscsi_sendcommand(host);
+	    break;
+
+	case 0x8b:			/* -> PHASE_STATUS				*/
+	case 0x1b:			/* -> PHASE_STATUS				*/
+	    /* MESSAGE OUT -> STATUS */
+	    acornscsi_readstatusbyte(host);
+	    host->scsi.phase = PHASE_STATUSIN;
+	    break;
+
+	case 0x8e:			/* -> PHASE_MSGOUT				*/
+	    /* MESSAGE_OUT(MESSAGE_IN) ->MESSAGE OUT */
+	    acornscsi_sendmessage(host);
+	    break;
+
+	case 0x4f:			/* -> PHASE_MSGIN, PHASE_DISCONNECT		*/
+	case 0x1f:			/* -> PHASE_MSGIN, PHASE_DISCONNECT		*/
+	    /* MESSAGE OUT -> MESSAGE IN */
+	    acornscsi_message(host);
+	    break;
+
+	default:
+	    printk(KERN_ERR "scsi%d.%c: PHASE_MSGOUT, SSR %02X?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	}
+	return INTR_PROCESSING;
+
+    case PHASE_COMMAND: 		/* STATE: connected & command sent		*/
+	switch (ssr) {
+	case 0x18:			/* -> PHASE_DATAOUT				*/
+	    /* COMMAND -> DATA OUT */
+	    if (host->scsi.SCp.sent_command != host->SCpnt->cmd_len)
+		acornscsi_abortcmd(host, host->SCpnt->tag);
+	    acornscsi_dma_setup(host, DMA_OUT);
+	    if (!acornscsi_starttransfer(host))
+		acornscsi_abortcmd(host, host->SCpnt->tag);
+	    host->scsi.phase = PHASE_DATAOUT;
+	    return INTR_IDLE;
+
+	case 0x19:			/* -> PHASE_DATAIN				*/
+	    /* COMMAND -> DATA IN */
+	    if (host->scsi.SCp.sent_command != host->SCpnt->cmd_len)
+		acornscsi_abortcmd(host, host->SCpnt->tag);
+	    acornscsi_dma_setup(host, DMA_IN);
+	    if (!acornscsi_starttransfer(host))
+		acornscsi_abortcmd(host, host->SCpnt->tag);
+	    host->scsi.phase = PHASE_DATAIN;
+	    return INTR_IDLE;
+
+	case 0x1b:			/* -> PHASE_STATUS				*/
+	    /* COMMAND -> STATUS */
+	    acornscsi_readstatusbyte(host);
+	    host->scsi.phase = PHASE_STATUSIN;
+	    break;
+
+	case 0x1e:			/* -> PHASE_MSGOUT				*/
+	    /* COMMAND -> MESSAGE OUT */
+	    acornscsi_sendmessage(host);
+	    break;
+
+	case 0x1f:			/* -> PHASE_MSGIN, PHASE_DISCONNECT		*/
+	    /* COMMAND -> MESSAGE IN */
+	    acornscsi_message(host);
+	    break;
+
+	default:
+	    printk(KERN_ERR "scsi%d.%c: PHASE_COMMAND, SSR %02X?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	}
+	return INTR_PROCESSING;
+
+    case PHASE_DISCONNECT:		/* STATE: connected, received DISCONNECT msg	*/
+	if (ssr == 0x85) {		/* -> PHASE_IDLE				*/
+	    host->scsi.disconnectable = 1;
+	    host->scsi.reconnected.tag = 0;
+	    host->scsi.phase = PHASE_IDLE;
+	    host->stats.disconnects += 1;
+	} else {
+	    printk(KERN_ERR "scsi%d.%c: PHASE_DISCONNECT, SSR %02X instead of disconnect?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	}
+	return INTR_NEXT_COMMAND;
+
+    case PHASE_IDLE:			/* STATE: disconnected				*/
+	if (ssr == 0x81)		/* -> PHASE_RECONNECTED or PHASE_ABORTED	*/
+	    acornscsi_reconnect(host);
+	else {
+	    printk(KERN_ERR "scsi%d.%c: PHASE_IDLE, SSR %02X while idle?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	}
+	return INTR_PROCESSING;
+
+    case PHASE_RECONNECTED:		/* STATE: device reconnected to initiator	*/
+	/*
+	 * Command reconnected - if MESGIN, get message - it may be
+	 * the tag.  If not, get command out of disconnected queue
+	 */
+	/*
+	 * If we reconnected and we're not in MESSAGE IN phase after IDENTIFY,
+	 * reconnect I_T_L command
+	 */
+	if (ssr != 0x8f && !acornscsi_reconnect_finish(host))
+	    return INTR_IDLE;
+	ADD_STATUS(host->SCpnt->device->id, ssr, host->scsi.phase, in_irq);
+	switch (ssr) {
+	case 0x88:			/* data out phase				*/
+					/* -> PHASE_DATAOUT				*/
+	    /* MESSAGE IN -> DATA OUT */
+	    acornscsi_dma_setup(host, DMA_OUT);
+	    if (!acornscsi_starttransfer(host))
+		acornscsi_abortcmd(host, host->SCpnt->tag);
+	    host->scsi.phase = PHASE_DATAOUT;
+	    return INTR_IDLE;
+
+	case 0x89:			/* data in phase				*/
+					/* -> PHASE_DATAIN				*/
+	    /* MESSAGE IN -> DATA IN */
+	    acornscsi_dma_setup(host, DMA_IN);
+	    if (!acornscsi_starttransfer(host))
+		acornscsi_abortcmd(host, host->SCpnt->tag);
+	    host->scsi.phase = PHASE_DATAIN;
+	    return INTR_IDLE;
+
+	case 0x8a:			/* command out					*/
+	    /* MESSAGE IN -> COMMAND */
+	    acornscsi_sendcommand(host);/* -> PHASE_COMMAND, PHASE_COMMANDPAUSED	*/
+	    break;
+
+	case 0x8b:			/* status in					*/
+					/* -> PHASE_STATUSIN				*/
+	    /* MESSAGE IN -> STATUS */
+	    acornscsi_readstatusbyte(host);
+	    host->scsi.phase = PHASE_STATUSIN;
+	    break;
+
+	case 0x8e:			/* message out					*/
+					/* -> PHASE_MSGOUT				*/
+	    /* MESSAGE IN -> MESSAGE OUT */
+	    acornscsi_sendmessage(host);
+	    break;
+
+	case 0x8f:			/* message in					*/
+	    acornscsi_message(host);	/* -> PHASE_MSGIN, PHASE_DISCONNECT		*/
+	    break;
+
+	default:
+	    printk(KERN_ERR "scsi%d.%c: PHASE_RECONNECTED, SSR %02X after reconnect?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	}
+	return INTR_PROCESSING;
+
+    case PHASE_DATAIN:			/* STATE: transferred data in			*/
+	/*
+	 * This is simple - if we disconnect then the DMA address & count is
+	 * correct.
+	 */
+	switch (ssr) {
+	case 0x19:			/* -> PHASE_DATAIN				*/
+	case 0x89:			/* -> PHASE_DATAIN				*/
+	    acornscsi_abortcmd(host, host->SCpnt->tag);
+	    return INTR_IDLE;
+
+	case 0x1b:			/* -> PHASE_STATUSIN				*/
+	case 0x4b:			/* -> PHASE_STATUSIN				*/
+	case 0x8b:			/* -> PHASE_STATUSIN				*/
+	    /* DATA IN -> STATUS */
+	    host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
+					  acornscsi_sbic_xfcount(host);
+	    acornscsi_dma_stop(host);
+	    acornscsi_readstatusbyte(host);
+	    host->scsi.phase = PHASE_STATUSIN;
+	    break;
+
+	case 0x1e:			/* -> PHASE_MSGOUT				*/
+	case 0x4e:			/* -> PHASE_MSGOUT				*/
+	case 0x8e:			/* -> PHASE_MSGOUT				*/
+	    /* DATA IN -> MESSAGE OUT */
+	    host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
+					  acornscsi_sbic_xfcount(host);
+	    acornscsi_dma_stop(host);
+	    acornscsi_sendmessage(host);
+	    break;
+
+	case 0x1f:			/* message in					*/
+	case 0x4f:			/* message in					*/
+	case 0x8f:			/* message in					*/
+	    /* DATA IN -> MESSAGE IN */
+	    host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
+					  acornscsi_sbic_xfcount(host);
+	    acornscsi_dma_stop(host);
+	    acornscsi_message(host);	/* -> PHASE_MSGIN, PHASE_DISCONNECT		*/
+	    break;
+
+	default:
+	    printk(KERN_ERR "scsi%d.%c: PHASE_DATAIN, SSR %02X?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	}
+	return INTR_PROCESSING;
+
+    case PHASE_DATAOUT: 		/* STATE: transferred data out			*/
+	/*
+	 * This is more complicated - if we disconnect, the DMA could be 12
+	 * bytes ahead of us.  We need to correct this.
+	 */
+	switch (ssr) {
+	case 0x18:			/* -> PHASE_DATAOUT				*/
+	case 0x88:			/* -> PHASE_DATAOUT				*/
+	    acornscsi_abortcmd(host, host->SCpnt->tag);
+	    return INTR_IDLE;
+
+	case 0x1b:			/* -> PHASE_STATUSIN				*/
+	case 0x4b:			/* -> PHASE_STATUSIN				*/
+	case 0x8b:			/* -> PHASE_STATUSIN				*/
+	    /* DATA OUT -> STATUS */
+	    host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
+					  acornscsi_sbic_xfcount(host);
+	    acornscsi_dma_stop(host);
+	    acornscsi_dma_adjust(host);
+	    acornscsi_readstatusbyte(host);
+	    host->scsi.phase = PHASE_STATUSIN;
+	    break;
+
+	case 0x1e:			/* -> PHASE_MSGOUT				*/
+	case 0x4e:			/* -> PHASE_MSGOUT				*/
+	case 0x8e:			/* -> PHASE_MSGOUT				*/
+	    /* DATA OUT -> MESSAGE OUT */
+	    host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
+					  acornscsi_sbic_xfcount(host);
+	    acornscsi_dma_stop(host);
+	    acornscsi_dma_adjust(host);
+	    acornscsi_sendmessage(host);
+	    break;
+
+	case 0x1f:			/* message in					*/
+	case 0x4f:			/* message in					*/
+	case 0x8f:			/* message in					*/
+	    /* DATA OUT -> MESSAGE IN */
+	    host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
+					  acornscsi_sbic_xfcount(host);
+	    acornscsi_dma_stop(host);
+	    acornscsi_dma_adjust(host);
+	    acornscsi_message(host);	/* -> PHASE_MSGIN, PHASE_DISCONNECT		*/
+	    break;
+
+	default:
+	    printk(KERN_ERR "scsi%d.%c: PHASE_DATAOUT, SSR %02X?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	}
+	return INTR_PROCESSING;
+
+    case PHASE_STATUSIN:		/* STATE: status in complete			*/
+	switch (ssr) {
+	case 0x1f:			/* -> PHASE_MSGIN, PHASE_DONE, PHASE_DISCONNECT */
+	case 0x8f:			/* -> PHASE_MSGIN, PHASE_DONE, PHASE_DISCONNECT */
+	    /* STATUS -> MESSAGE IN */
+	    acornscsi_message(host);
+	    break;
+
+	case 0x1e:			/* -> PHASE_MSGOUT				*/
+	case 0x8e:			/* -> PHASE_MSGOUT				*/
+	    /* STATUS -> MESSAGE OUT */
+	    acornscsi_sendmessage(host);
+	    break;
+
+	default:
+	    printk(KERN_ERR "scsi%d.%c: PHASE_STATUSIN, SSR %02X instead of MESSAGE_IN?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	}
+	return INTR_PROCESSING;
+
+    case PHASE_MSGIN:			/* STATE: message in				*/
+	switch (ssr) {
+	case 0x1e:			/* -> PHASE_MSGOUT				*/
+	case 0x4e:			/* -> PHASE_MSGOUT				*/
+	case 0x8e:			/* -> PHASE_MSGOUT				*/
+	    /* MESSAGE IN -> MESSAGE OUT */
+	    acornscsi_sendmessage(host);
+	    break;
+
+	case 0x1f:			/* -> PHASE_MSGIN, PHASE_DONE, PHASE_DISCONNECT */
+	case 0x2f:
+	case 0x4f:
+	case 0x8f:
+	    acornscsi_message(host);
+	    break;
+
+	case 0x85:
+	    printk("scsi%d.%c: strange message in disconnection\n",
+		host->host->host_no, acornscsi_target(host));
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	    acornscsi_done(host, &host->SCpnt, DID_ERROR);
+	    break;
+
+	default:
+	    printk(KERN_ERR "scsi%d.%c: PHASE_MSGIN, SSR %02X after message in?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	}
+	return INTR_PROCESSING;
+
+    case PHASE_DONE:			/* STATE: received status & message		*/
+	switch (ssr) {
+	case 0x85:			/* -> PHASE_IDLE				*/
+	    acornscsi_done(host, &host->SCpnt, DID_OK);
+	    return INTR_NEXT_COMMAND;
+
+	case 0x1e:
+	case 0x8e:
+	    acornscsi_sendmessage(host);
+	    break;
+
+	default:
+	    printk(KERN_ERR "scsi%d.%c: PHASE_DONE, SSR %02X instead of disconnect?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	}
+	return INTR_PROCESSING;
+
+    case PHASE_ABORTED:
+	switch (ssr) {
+	case 0x85:
+	    if (host->SCpnt)
+		acornscsi_done(host, &host->SCpnt, DID_ABORT);
+	    else {
+		clear_bit(host->scsi.reconnected.target * 8 + host->scsi.reconnected.lun,
+			  host->busyluns);
+		host->scsi.phase = PHASE_IDLE;
+	    }
+	    return INTR_NEXT_COMMAND;
+
+	case 0x1e:
+	case 0x2e:
+	case 0x4e:
+	case 0x8e:
+	    acornscsi_sendmessage(host);
+	    break;
+
+	default:
+	    printk(KERN_ERR "scsi%d.%c: PHASE_ABORTED, SSR %02X?\n",
+		    host->host->host_no, acornscsi_target(host), ssr);
+	    acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+	}
+	return INTR_PROCESSING;
+
+    default:
+	printk(KERN_ERR "scsi%d.%c: unknown driver phase %d\n",
+		host->host->host_no, acornscsi_target(host), ssr);
+	acornscsi_dumplog(host, host->SCpnt ? host->SCpnt->device->id : 8);
+    }
+    return INTR_PROCESSING;
+}
+
+/*
+ * Prototype: void acornscsi_intr(int irq, void *dev_id)
+ * Purpose  : handle interrupts from Acorn SCSI card
+ * Params   : irq    - interrupt number
+ *	      dev_id - device specific data (AS_Host structure)
+ */
+static irqreturn_t
+acornscsi_intr(int irq, void *dev_id)
+{
+    AS_Host *host = (AS_Host *)dev_id;
+    intr_ret_t ret;
+    int iostatus;
+    int in_irq = 0;
+
+    do {
+	ret = INTR_IDLE;
+
+	iostatus = readb(host->fast + INT_REG);
+
+	if (iostatus & 2) {
+	    acornscsi_dma_intr(host);
+	    iostatus = readb(host->fast + INT_REG);
+	}
+
+	if (iostatus & 8)
+	    ret = acornscsi_sbicintr(host, in_irq);
+
+	/*
+	 * If we have a transfer pending, start it.
+	 * Only start it if the interface has already started transferring
+	 * it's data
+	 */
+	if (host->dma.xfer_required)
+	    acornscsi_dma_xfer(host);
+
+	if (ret == INTR_NEXT_COMMAND)
+	    ret = acornscsi_kick(host);
+
+	in_irq = 1;
+    } while (ret != INTR_IDLE);
+
+    return IRQ_HANDLED;
+}
+
+/*=============================================================================================
+ * Interfaces between interrupt handler and rest of scsi code
+ */
+
+/*
+ * Function : acornscsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
+ * Purpose  : queues a SCSI command
+ * Params   : cmd  - SCSI command
+ *	      done - function called on completion, with pointer to command descriptor
+ * Returns  : 0, or < 0 on error.
+ */
+static int acornscsi_queuecmd_lck(struct scsi_cmnd *SCpnt,
+		       void (*done)(struct scsi_cmnd *))
+{
+    AS_Host *host = (AS_Host *)SCpnt->device->host->hostdata;
+
+    if (!done) {
+	/* there should be some way of rejecting errors like this without panicing... */
+	panic("scsi%d: queuecommand called with NULL done function [cmd=%p]",
+		host->host->host_no, SCpnt);
+	return -EINVAL;
+    }
+
+#if (DEBUG & DEBUG_NO_WRITE)
+    if (acornscsi_cmdtype(SCpnt->cmnd[0]) == CMD_WRITE && (NO_WRITE & (1 << SCpnt->device->id))) {
+	printk(KERN_CRIT "scsi%d.%c: WRITE attempted with NO_WRITE flag set\n",
+	    host->host->host_no, '0' + SCpnt->device->id);
+	SCpnt->result = DID_NO_CONNECT << 16;
+	done(SCpnt);
+	return 0;
+    }
+#endif
+
+    SCpnt->scsi_done = done;
+    SCpnt->host_scribble = NULL;
+    SCpnt->result = 0;
+    SCpnt->tag = 0;
+    SCpnt->SCp.phase = (int)acornscsi_datadirection(SCpnt->cmnd[0]);
+    SCpnt->SCp.sent_command = 0;
+    SCpnt->SCp.scsi_xferred = 0;
+
+    init_SCp(SCpnt);
+
+    host->stats.queues += 1;
+
+    {
+	unsigned long flags;
+
+	if (!queue_add_cmd_ordered(&host->queues.issue, SCpnt)) {
+	    SCpnt->result = DID_ERROR << 16;
+	    done(SCpnt);
+	    return 0;
+	}
+	local_irq_save(flags);
+	if (host->scsi.phase == PHASE_IDLE)
+	    acornscsi_kick(host);
+	local_irq_restore(flags);
+    }
+    return 0;
+}
+
+DEF_SCSI_QCMD(acornscsi_queuecmd)
+
+/*
+ * Prototype: void acornscsi_reportstatus(struct scsi_cmnd **SCpntp1, struct scsi_cmnd **SCpntp2, int result)
+ * Purpose  : pass a result to *SCpntp1, and check if *SCpntp1 = *SCpntp2
+ * Params   : SCpntp1 - pointer to command to return
+ *	      SCpntp2 - pointer to command to check
+ *	      result  - result to pass back to mid-level done function
+ * Returns  : *SCpntp2 = NULL if *SCpntp1 is the same command structure as *SCpntp2.
+ */
+static inline void acornscsi_reportstatus(struct scsi_cmnd **SCpntp1,
+					  struct scsi_cmnd **SCpntp2,
+					  int result)
+{
+	struct scsi_cmnd *SCpnt = *SCpntp1;
+
+    if (SCpnt) {
+	*SCpntp1 = NULL;
+
+	SCpnt->result = result;
+	SCpnt->scsi_done(SCpnt);
+    }
+
+    if (SCpnt == *SCpntp2)
+	*SCpntp2 = NULL;
+}
+
+enum res_abort { res_not_running, res_success, res_success_clear, res_snooze };
+
+/*
+ * Prototype: enum res acornscsi_do_abort(struct scsi_cmnd *SCpnt)
+ * Purpose  : abort a command on this host
+ * Params   : SCpnt - command to abort
+ * Returns  : our abort status
+ */
+static enum res_abort acornscsi_do_abort(AS_Host *host, struct scsi_cmnd *SCpnt)
+{
+	enum res_abort res = res_not_running;
+
+	if (queue_remove_cmd(&host->queues.issue, SCpnt)) {
+		/*
+		 * The command was on the issue queue, and has not been
+		 * issued yet.  We can remove the command from the queue,
+		 * and acknowledge the abort.  Neither the devices nor the
+		 * interface know about the command.
+		 */
+//#if (DEBUG & DEBUG_ABORT)
+		printk("on issue queue ");
+//#endif
+		res = res_success;
+	} else if (queue_remove_cmd(&host->queues.disconnected, SCpnt)) {
+		/*
+		 * The command was on the disconnected queue.  Simply
+		 * acknowledge the abort condition, and when the target
+		 * reconnects, we will give it an ABORT message.  The
+		 * target should then disconnect, and we will clear
+		 * the busylun bit.
+		 */
+//#if (DEBUG & DEBUG_ABORT)
+		printk("on disconnected queue ");
+//#endif
+		res = res_success;
+	} else if (host->SCpnt == SCpnt) {
+		unsigned long flags;
+
+//#if (DEBUG & DEBUG_ABORT)
+		printk("executing ");
+//#endif
+
+		local_irq_save(flags);
+		switch (host->scsi.phase) {
+		/*
+		 * If the interface is idle, and the command is 'disconnectable',
+		 * then it is the same as on the disconnected queue.  We simply
+		 * remove all traces of the command.  When the target reconnects,
+		 * we will give it an ABORT message since the command could not
+		 * be found.  When the target finally disconnects, we will clear
+		 * the busylun bit.
+		 */
+		case PHASE_IDLE:
+			if (host->scsi.disconnectable) {
+				host->scsi.disconnectable = 0;
+				host->SCpnt = NULL;
+				res = res_success;
+			}
+			break;
+
+		/*
+		 * If the command has connected and done nothing further,
+		 * simply force a disconnect.  We also need to clear the
+		 * busylun bit.
+		 */
+		case PHASE_CONNECTED:
+			sbic_arm_write(host, SBIC_CMND, CMND_DISCONNECT);
+			host->SCpnt = NULL;
+			res = res_success_clear;
+			break;
+
+		default:
+			acornscsi_abortcmd(host, host->SCpnt->tag);
+			res = res_snooze;
+		}
+		local_irq_restore(flags);
+	} else if (host->origSCpnt == SCpnt) {
+		/*
+		 * The command will be executed next, but a command
+		 * is currently using the interface.  This is similar to
+		 * being on the issue queue, except the busylun bit has
+		 * been set.
+		 */
+		host->origSCpnt = NULL;
+//#if (DEBUG & DEBUG_ABORT)
+		printk("waiting for execution ");
+//#endif
+		res = res_success_clear;
+	} else
+		printk("unknown ");
+
+	return res;
+}
+
+/*
+ * Prototype: int acornscsi_abort(struct scsi_cmnd *SCpnt)
+ * Purpose  : abort a command on this host
+ * Params   : SCpnt - command to abort
+ * Returns  : one of SCSI_ABORT_ macros
+ */
+int acornscsi_abort(struct scsi_cmnd *SCpnt)
+{
+	AS_Host *host = (AS_Host *) SCpnt->device->host->hostdata;
+	int result;
+
+	host->stats.aborts += 1;
+
+#if (DEBUG & DEBUG_ABORT)
+	{
+		int asr, ssr;
+		asr = sbic_arm_read(host, SBIC_ASR);
+		ssr = sbic_arm_read(host, SBIC_SSR);
+
+		printk(KERN_WARNING "acornscsi_abort: ");
+		print_sbic_status(asr, ssr, host->scsi.phase);
+		acornscsi_dumplog(host, SCpnt->device->id);
+	}
+#endif
+
+	printk("scsi%d: ", host->host->host_no);
+
+	switch (acornscsi_do_abort(host, SCpnt)) {
+	/*
+	 * We managed to find the command and cleared it out.
+	 * We do not expect the command to be executing on the
+	 * target, but we have set the busylun bit.
+	 */
+	case res_success_clear:
+//#if (DEBUG & DEBUG_ABORT)
+		printk("clear ");
+//#endif
+		clear_bit(SCpnt->device->id * 8 +
+			  (u8)(SCpnt->device->lun & 0x7), host->busyluns);
+
+	/*
+	 * We found the command, and cleared it out.  Either
+	 * the command is still known to be executing on the
+	 * target, or the busylun bit is not set.
+	 */
+	case res_success:
+//#if (DEBUG & DEBUG_ABORT)
+		printk("success\n");
+//#endif
+		result = SUCCESS;
+		break;
+
+	/*
+	 * We did find the command, but unfortunately we couldn't
+	 * unhook it from ourselves.  Wait some more, and if it
+	 * still doesn't complete, reset the interface.
+	 */
+	case res_snooze:
+//#if (DEBUG & DEBUG_ABORT)
+		printk("snooze\n");
+//#endif
+		result = FAILED;
+		break;
+
+	/*
+	 * The command could not be found (either because it completed,
+	 * or it got dropped.
+	 */
+	default:
+	case res_not_running:
+		acornscsi_dumplog(host, SCpnt->device->id);
+		result = FAILED;
+//#if (DEBUG & DEBUG_ABORT)
+		printk("not running\n");
+//#endif
+		break;
+	}
+
+	return result;
+}
+
+/*
+ * Prototype: int acornscsi_reset(struct scsi_cmnd *SCpnt)
+ * Purpose  : reset a command on this host/reset this host
+ * Params   : SCpnt  - command causing reset
+ * Returns  : one of SCSI_RESET_ macros
+ */
+int acornscsi_host_reset(struct scsi_cmnd *SCpnt)
+{
+	AS_Host *host = (AS_Host *)SCpnt->device->host->hostdata;
+	struct scsi_cmnd *SCptr;
+    
+    host->stats.resets += 1;
+
+#if (DEBUG & DEBUG_RESET)
+    {
+	int asr, ssr, devidx;
+
+	asr = sbic_arm_read(host, SBIC_ASR);
+	ssr = sbic_arm_read(host, SBIC_SSR);
+
+	printk(KERN_WARNING "acornscsi_reset: ");
+	print_sbic_status(asr, ssr, host->scsi.phase);
+	for (devidx = 0; devidx < 9; devidx++)
+	    acornscsi_dumplog(host, devidx);
+    }
+#endif
+
+    acornscsi_dma_stop(host);
+
+    /*
+     * do hard reset.  This resets all devices on this host, and so we
+     * must set the reset status on all commands.
+     */
+    acornscsi_resetcard(host);
+
+    while ((SCptr = queue_remove(&host->queues.disconnected)) != NULL)
+	;
+
+    return SUCCESS;
+}
+
+/*==============================================================================================
+ * initialisation & miscellaneous support
+ */
+
+/*
+ * Function: char *acornscsi_info(struct Scsi_Host *host)
+ * Purpose : return a string describing this interface
+ * Params  : host - host to give information on
+ * Returns : a constant string
+ */
+const
+char *acornscsi_info(struct Scsi_Host *host)
+{
+    static char string[100], *p;
+
+    p = string;
+    
+    p += sprintf(string, "%s at port %08lX irq %d v%d.%d.%d"
+#ifdef CONFIG_SCSI_ACORNSCSI_SYNC
+    " SYNC"
+#endif
+#ifdef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
+    " TAG"
+#endif
+#if (DEBUG & DEBUG_NO_WRITE)
+    " NOWRITE (" __stringify(NO_WRITE) ")"
+#endif
+		, host->hostt->name, host->io_port, host->irq,
+		VER_MAJOR, VER_MINOR, VER_PATCH);
+    return string;
+}
+
+static int acornscsi_show_info(struct seq_file *m, struct Scsi_Host *instance)
+{
+    int devidx;
+    struct scsi_device *scd;
+    AS_Host *host;
+
+    host  = (AS_Host *)instance->hostdata;
+    
+    seq_printf(m, "AcornSCSI driver v%d.%d.%d"
+#ifdef CONFIG_SCSI_ACORNSCSI_SYNC
+    " SYNC"
+#endif
+#ifdef CONFIG_SCSI_ACORNSCSI_TAGGED_QUEUE
+    " TAG"
+#endif
+#if (DEBUG & DEBUG_NO_WRITE)
+    " NOWRITE (" __stringify(NO_WRITE) ")"
+#endif
+		"\n\n", VER_MAJOR, VER_MINOR, VER_PATCH);
+
+    seq_printf(m,	"SBIC: WD33C93A  Address: %p    IRQ : %d\n",
+			host->base + SBIC_REGIDX, host->scsi.irq);
+#ifdef USE_DMAC
+    seq_printf(m,	"DMAC: uPC71071  Address: %p  IRQ : %d\n\n",
+			host->base + DMAC_OFFSET, host->scsi.irq);
+#endif
+
+    seq_printf(m,	"Statistics:\n"
+			"Queued commands: %-10u    Issued commands: %-10u\n"
+			"Done commands  : %-10u    Reads          : %-10u\n"
+			"Writes         : %-10u    Others         : %-10u\n"
+			"Disconnects    : %-10u    Aborts         : %-10u\n"
+			"Resets         : %-10u\n\nLast phases:",
+			host->stats.queues,		host->stats.removes,
+			host->stats.fins,		host->stats.reads,
+			host->stats.writes,		host->stats.miscs,
+			host->stats.disconnects,	host->stats.aborts,
+			host->stats.resets);
+
+    for (devidx = 0; devidx < 9; devidx ++) {
+	unsigned int statptr, prev;
+
+	seq_printf(m, "\n%c:", devidx == 8 ? 'H' : ('0' + devidx));
+	statptr = host->status_ptr[devidx] - 10;
+
+	if ((signed int)statptr < 0)
+	    statptr += STATUS_BUFFER_SIZE;
+
+	prev = host->status[devidx][statptr].when;
+
+	for (; statptr != host->status_ptr[devidx]; statptr = (statptr + 1) & (STATUS_BUFFER_SIZE - 1)) {
+	    if (host->status[devidx][statptr].when) {
+		seq_printf(m, "%c%02X:%02X+%2ld",
+			host->status[devidx][statptr].irq ? '-' : ' ',
+			host->status[devidx][statptr].ph,
+			host->status[devidx][statptr].ssr,
+			(host->status[devidx][statptr].when - prev) < 100 ?
+				(host->status[devidx][statptr].when - prev) : 99);
+		prev = host->status[devidx][statptr].when;
+	    }
+	}
+    }
+
+    seq_printf(m, "\nAttached devices:\n");
+
+    shost_for_each_device(scd, instance) {
+	seq_printf(m, "Device/Lun TaggedQ      Sync\n");
+	seq_printf(m, "     %d/%llu   ", scd->id, scd->lun);
+	if (scd->tagged_supported)
+		seq_printf(m, "%3sabled(%3d) ",
+			     scd->simple_tags ? "en" : "dis",
+			     scd->current_tag);
+	else
+		seq_printf(m, "unsupported  ");
+
+	if (host->device[scd->id].sync_xfer & 15)
+		seq_printf(m, "offset %d, %d ns\n",
+			     host->device[scd->id].sync_xfer & 15,
+			     acornscsi_getperiod(host->device[scd->id].sync_xfer));
+	else
+		seq_printf(m, "async\n");
+
+    }
+    return 0;
+}
+
+static struct scsi_host_template acornscsi_template = {
+	.module			= THIS_MODULE,
+	.show_info		= acornscsi_show_info,
+	.name			= "AcornSCSI",
+	.info			= acornscsi_info,
+	.queuecommand		= acornscsi_queuecmd,
+	.eh_abort_handler	= acornscsi_abort,
+	.eh_host_reset_handler	= acornscsi_host_reset,
+	.can_queue		= 16,
+	.this_id		= 7,
+	.sg_tablesize		= SG_ALL,
+	.cmd_per_lun		= 2,
+	.use_clustering		= DISABLE_CLUSTERING,
+	.proc_name		= "acornscsi",
+};
+
+static int acornscsi_probe(struct expansion_card *ec, const struct ecard_id *id)
+{
+	struct Scsi_Host *host;
+	AS_Host *ashost;
+	int ret;
+
+	ret = ecard_request_resources(ec);
+	if (ret)
+		goto out;
+
+	host = scsi_host_alloc(&acornscsi_template, sizeof(AS_Host));
+	if (!host) {
+		ret = -ENOMEM;
+		goto out_release;
+	}
+
+	ashost = (AS_Host *)host->hostdata;
+
+	ashost->base = ecardm_iomap(ec, ECARD_RES_MEMC, 0, 0);
+	ashost->fast = ecardm_iomap(ec, ECARD_RES_IOCFAST, 0, 0);
+	if (!ashost->base || !ashost->fast) {
+		ret = -ENOMEM;
+		goto out_put;
+	}
+
+	host->irq = ec->irq;
+	ashost->host = host;
+	ashost->scsi.irq = host->irq;
+
+	ec->irqaddr	= ashost->fast + INT_REG;
+	ec->irqmask	= 0x0a;
+
+	ret = request_irq(host->irq, acornscsi_intr, 0, "acornscsi", ashost);
+	if (ret) {
+		printk(KERN_CRIT "scsi%d: IRQ%d not free: %d\n",
+			host->host_no, ashost->scsi.irq, ret);
+		goto out_put;
+	}
+
+	memset(&ashost->stats, 0, sizeof (ashost->stats));
+	queue_initialise(&ashost->queues.issue);
+	queue_initialise(&ashost->queues.disconnected);
+	msgqueue_initialise(&ashost->scsi.msgs);
+
+	acornscsi_resetcard(ashost);
+
+	ret = scsi_add_host(host, &ec->dev);
+	if (ret)
+		goto out_irq;
+
+	scsi_scan_host(host);
+	goto out;
+
+ out_irq:
+	free_irq(host->irq, ashost);
+	msgqueue_free(&ashost->scsi.msgs);
+	queue_free(&ashost->queues.disconnected);
+	queue_free(&ashost->queues.issue);
+ out_put:
+	ecardm_iounmap(ec, ashost->fast);
+	ecardm_iounmap(ec, ashost->base);
+	scsi_host_put(host);
+ out_release:
+	ecard_release_resources(ec);
+ out:
+	return ret;
+}
+
+static void acornscsi_remove(struct expansion_card *ec)
+{
+	struct Scsi_Host *host = ecard_get_drvdata(ec);
+	AS_Host *ashost = (AS_Host *)host->hostdata;
+
+	ecard_set_drvdata(ec, NULL);
+	scsi_remove_host(host);
+
+	/*
+	 * Put card into RESET state
+	 */
+	writeb(0x80, ashost->fast + PAGE_REG);
+
+	free_irq(host->irq, ashost);
+
+	msgqueue_free(&ashost->scsi.msgs);
+	queue_free(&ashost->queues.disconnected);
+	queue_free(&ashost->queues.issue);
+	ecardm_iounmap(ec, ashost->fast);
+	ecardm_iounmap(ec, ashost->base);
+	scsi_host_put(host);
+	ecard_release_resources(ec);
+}
+
+static const struct ecard_id acornscsi_cids[] = {
+	{ MANU_ACORN, PROD_ACORN_SCSI },
+	{ 0xffff, 0xffff },
+};
+
+static struct ecard_driver acornscsi_driver = {
+	.probe		= acornscsi_probe,
+	.remove		= acornscsi_remove,
+	.id_table	= acornscsi_cids,
+	.drv = {
+		.name		= "acornscsi",
+	},
+};
+
+static int __init acornscsi_init(void)
+{
+	return ecard_register_driver(&acornscsi_driver);
+}
+
+static void __exit acornscsi_exit(void)
+{
+	ecard_remove_driver(&acornscsi_driver);
+}
+
+module_init(acornscsi_init);
+module_exit(acornscsi_exit);
+
+MODULE_AUTHOR("Russell King");
+MODULE_DESCRIPTION("AcornSCSI driver");
+MODULE_LICENSE("GPL");