Linux-2.6.12-rc2v2.6.12-rc2

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

Let it rip!

1 files changed, 6102 insertions, 0 deletions

diff --git a/drivers/scsi/53c7xx.c b/drivers/scsi/53c7xx.c
new file mode 100644
index 00000000000..8ead55f75d0
--- /dev/null
+++ b/drivers/scsi/53c7xx.c
@@ -0,0 +1,6102 @@
+/*
+ * 53c710 driver.  Modified from Drew Eckhardts driver
+ * for 53c810 by Richard Hirst [richard@sleepie.demon.co.uk]
+ * Check out PERM_OPTIONS and EXPECTED_CLOCK, which may be defined in the
+ * relevant machine specific file (eg. mvme16x.[ch], amiga7xx.[ch]).
+ * There are also currently some defines at the top of 53c7xx.scr.
+ * The chip type is #defined in script_asm.pl, as well as the Makefile.
+ * Host scsi ID expected to be 7 - see NCR53c7x0_init().
+ *
+ * I have removed the PCI code and some of the 53c8xx specific code - 
+ * simply to make this file smaller and easier to manage.
+ *
+ * MVME16x issues:
+ *   Problems trying to read any chip registers in NCR53c7x0_init(), as they
+ *   may never have been set by 16xBug (eg. If kernel has come in over tftp).
+ */
+
+/*
+ * Adapted for Linux/m68k Amiga platforms for the A4000T/A4091 and
+ * WarpEngine SCSI controllers.
+ * By Alan Hourihane <alanh@fairlite.demon.co.uk>
+ * Thanks to Richard Hirst for making it possible with the MVME additions
+ */
+
+/*
+ * 53c710 rev 0 doesn't support add with carry.  Rev 1 and 2 does.  To
+ * overcome this problem you can define FORCE_DSA_ALIGNMENT, which ensures
+ * that the DSA address is always xxxxxx00.  If disconnection is not allowed,
+ * then the script only ever tries to add small (< 256) positive offsets to
+ * DSA, so lack of carry isn't a problem.  FORCE_DSA_ALIGNMENT can, of course,
+ * be defined for all chip revisions at a small cost in memory usage.
+ */
+
+#define FORCE_DSA_ALIGNMENT
+
+/*
+ * Selection timer does not always work on the 53c710, depending on the
+ * timing at the last disconnect, if this is a problem for you, try
+ * using validids as detailed below.
+ *
+ * Options for the NCR7xx driver
+ *
+ * noasync:0		-	disables sync and asynchronous negotiation
+ * nosync:0		-	disables synchronous negotiation (does async)
+ * nodisconnect:0	-	disables disconnection
+ * validids:0x??	-	Bitmask field that disallows certain ID's.
+ *			-	e.g.	0x03	allows ID 0,1
+ *			-		0x1F	allows ID 0,1,2,3,4
+ * opthi:n		-	replace top word of options with 'n'
+ * optlo:n		-	replace bottom word of options with 'n'
+ *			-	ALWAYS SPECIFY opthi THEN optlo <<<<<<<<<<
+ */
+
+/*
+ * PERM_OPTIONS are driver options which will be enabled for all NCR boards
+ * in the system at driver initialization time.
+ *
+ * Don't THINK about touching these in PERM_OPTIONS : 
+ *   OPTION_MEMORY_MAPPED 
+ * 	680x0 doesn't have an IO map!
+ *
+ *   OPTION_DEBUG_TEST1
+ *	Test 1 does bus mastering and interrupt tests, which will help weed 
+ *	out brain damaged main boards.
+ *
+ * Other PERM_OPTIONS settings are listed below.  Note the actual options
+ * required are set in the relevant file (mvme16x.c, amiga7xx.c, etc):
+ *
+ *   OPTION_NO_ASYNC
+ *	Don't negotiate for asynchronous transfers on the first command 
+ *	when OPTION_ALWAYS_SYNCHRONOUS is set.  Useful for dain bramaged
+ *	devices which do something bad rather than sending a MESSAGE 
+ *	REJECT back to us like they should if they can't cope.
+ *
+ *   OPTION_SYNCHRONOUS
+ *	Enable support for synchronous transfers.  Target negotiated 
+ *	synchronous transfers will be responded to.  To initiate 
+ *	a synchronous transfer request,  call 
+ *
+ *	    request_synchronous (hostno, target) 
+ *
+ *	from within KGDB.
+ *
+ *   OPTION_ALWAYS_SYNCHRONOUS
+ *	Negotiate for synchronous transfers with every target after
+ *	driver initialization or a SCSI bus reset.  This is a bit dangerous, 
+ *	since there are some dain bramaged SCSI devices which will accept
+ *	SDTR messages but keep talking asynchronously.
+ *
+ *   OPTION_DISCONNECT
+ *	Enable support for disconnect/reconnect.  To change the 
+ *	default setting on a given host adapter, call
+ *
+ *	    request_disconnect (hostno, allow)
+ *
+ *	where allow is non-zero to allow, 0 to disallow.
+ * 
+ *  If you really want to run 10MHz FAST SCSI-II transfers, you should 
+ *  know that the NCR driver currently ignores parity information.  Most
+ *  systems do 5MHz SCSI fine.  I've seen a lot that have problems faster
+ *  than 8MHz.  To play it safe, we only request 5MHz transfers.
+ *
+ *  If you'd rather get 10MHz transfers, edit sdtr_message and change 
+ *  the fourth byte from 50 to 25.
+ */
+
+/*
+ * Sponsored by 
+ *	iX Multiuser Multitasking Magazine
+ *	Hannover, Germany
+ *	hm@ix.de
+ *
+ * Copyright 1993, 1994, 1995 Drew Eckhardt
+ *      Visionary Computing 
+ *      (Unix and Linux consulting and custom programming)
+ *      drew@PoohSticks.ORG
+ *	+1 (303) 786-7975
+ *
+ * TolerANT and SCSI SCRIPTS are registered trademarks of NCR Corporation.
+ * 
+ * For more information, please consult 
+ *
+ * NCR53C810 
+ * SCSI I/O Processor
+ * Programmer's Guide
+ *
+ * NCR 53C810
+ * PCI-SCSI I/O Processor
+ * Data Manual
+ *
+ * NCR 53C810/53C820
+ * PCI-SCSI I/O Processor Design In Guide
+ *
+ * For literature on Symbios Logic Inc. formerly NCR, SCSI, 
+ * and Communication products please call (800) 334-5454 or
+ * (719) 536-3300. 
+ * 
+ * PCI BIOS Specification Revision
+ * PCI Local Bus Specification
+ * PCI System Design Guide
+ *
+ * PCI Special Interest Group
+ * M/S HF3-15A
+ * 5200 N.E. Elam Young Parkway
+ * Hillsboro, Oregon 97124-6497
+ * +1 (503) 696-2000 
+ * +1 (800) 433-5177
+ */
+
+/*
+ * Design issues : 
+ * The cumulative latency needed to propagate a read/write request 
+ * through the file system, buffer cache, driver stacks, SCSI host, and 
+ * SCSI device is ultimately the limiting factor in throughput once we 
+ * have a sufficiently fast host adapter.
+ *  
+ * So, to maximize performance we want to keep the ratio of latency to data 
+ * transfer time to a minimum by
+ * 1.  Minimizing the total number of commands sent (typical command latency
+ *	including drive and bus mastering host overhead is as high as 4.5ms)
+ *	to transfer a given amount of data.  
+ *
+ *      This is accomplished by placing no arbitrary limit on the number
+ *	of scatter/gather buffers supported, since we can transfer 1K
+ *	per scatter/gather buffer without Eric's cluster patches, 
+ *	4K with.  
+ *
+ * 2.  Minimizing the number of fatal interrupts serviced, since
+ * 	fatal interrupts halt the SCSI I/O processor.  Basically,
+ *	this means offloading the practical maximum amount of processing 
+ *	to the SCSI chip.
+ * 
+ *	On the NCR53c810/820/720,  this is accomplished by using 
+ *		interrupt-on-the-fly signals when commands complete, 
+ *		and only handling fatal errors and SDTR / WDTR 	messages 
+ *		in the host code.
+ *
+ *	On the NCR53c710, interrupts are generated as on the NCR53c8x0,
+ *		only the lack of a interrupt-on-the-fly facility complicates
+ *		things.   Also, SCSI ID registers and commands are 
+ *		bit fielded rather than binary encoded.
+ *		
+ * 	On the NCR53c700 and NCR53c700-66, operations that are done via 
+ *		indirect, table mode on the more advanced chips must be
+ *	        replaced by calls through a jump table which 
+ *		acts as a surrogate for the DSA.  Unfortunately, this 
+ * 		will mean that we must service an interrupt for each 
+ *		disconnect/reconnect.
+ * 
+ * 3.  Eliminating latency by pipelining operations at the different levels.
+ * 	
+ *	This driver allows a configurable number of commands to be enqueued
+ *	for each target/lun combination (experimentally, I have discovered
+ *	that two seems to work best) and will ultimately allow for 
+ *	SCSI-II tagged queuing.
+ * 	
+ *
+ * Architecture : 
+ * This driver is built around a Linux queue of commands waiting to 
+ * be executed, and a shared Linux/NCR array of commands to start.  Commands
+ * are transferred to the array  by the run_process_issue_queue() function 
+ * which is called whenever a command completes.
+ *
+ * As commands are completed, the interrupt routine is triggered,
+ * looks for commands in the linked list of completed commands with
+ * valid status, removes these commands from a list of running commands, 
+ * calls the done routine, and flags their target/luns as not busy.
+ *
+ * Due to limitations in the intelligence of the NCR chips, certain
+ * concessions are made.  In many cases, it is easier to dynamically 
+ * generate/fix-up code rather than calculate on the NCR at run time.  
+ * So, code is generated or fixed up for
+ *
+ * - Handling data transfers, using a variable number of MOVE instructions
+ *	interspersed with CALL MSG_IN, WHEN MSGIN instructions.
+ *
+ * 	The DATAIN and DATAOUT routines	are separate, so that an incorrect
+ *	direction can be trapped, and space isn't wasted. 
+ *
+ *	It may turn out that we're better off using some sort 
+ *	of table indirect instruction in a loop with a variable
+ *	sized table on the NCR53c710 and newer chips.
+ *
+ * - Checking for reselection (NCR53c710 and better)
+ *
+ * - Handling the details of SCSI context switches (NCR53c710 and better),
+ *	such as reprogramming appropriate synchronous parameters, 
+ *	removing the dsa structure from the NCR's queue of outstanding
+ *	commands, etc.
+ *
+ */
+
+#include <linux/module.h>
+
+#include <linux/config.h>
+
+#include <linux/types.h>
+#include <asm/setup.h>
+#include <asm/dma.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <linux/delay.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/ioport.h>
+#include <linux/time.h>
+#include <linux/blkdev.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <asm/pgtable.h>
+
+#ifdef CONFIG_AMIGA
+#include <asm/amigahw.h>
+#include <asm/amigaints.h>
+#include <asm/irq.h>
+
+#define BIG_ENDIAN
+#define NO_IO_SPACE
+#endif
+
+#ifdef CONFIG_MVME16x
+#include <asm/mvme16xhw.h>
+
+#define BIG_ENDIAN
+#define NO_IO_SPACE
+#define VALID_IDS
+#endif
+
+#ifdef CONFIG_BVME6000
+#include <asm/bvme6000hw.h>
+
+#define BIG_ENDIAN
+#define NO_IO_SPACE
+#define VALID_IDS
+#endif
+
+#include "scsi.h"
+#include <scsi/scsi_host.h>
+#include "53c7xx.h"
+#include <linux/stat.h>
+#include <linux/stddef.h>
+
+#ifdef NO_IO_SPACE
+/*
+ * The following make the definitions in 53c7xx.h (write8, etc) smaller,
+ * we don't have separate i/o space anyway.
+ */
+#undef inb
+#undef outb
+#undef inw
+#undef outw
+#undef inl
+#undef outl
+#define inb(x)          1
+#define inw(x)          1
+#define inl(x)          1
+#define outb(x,y)       1
+#define outw(x,y)       1
+#define outl(x,y)       1
+#endif
+
+static int check_address (unsigned long addr, int size);
+static void dump_events (struct Scsi_Host *host, int count);
+static Scsi_Cmnd * return_outstanding_commands (struct Scsi_Host *host, 
+    int free, int issue);
+static void hard_reset (struct Scsi_Host *host);
+static void ncr_scsi_reset (struct Scsi_Host *host);
+static void print_lots (struct Scsi_Host *host);
+static void set_synchronous (struct Scsi_Host *host, int target, int sxfer, 
+    int scntl3, int now_connected);
+static int datapath_residual (struct Scsi_Host *host);
+static const char * sbcl_to_phase (int sbcl);
+static void print_progress (Scsi_Cmnd *cmd);
+static void print_queues (struct Scsi_Host *host);
+static void process_issue_queue (unsigned long flags);
+static int shutdown (struct Scsi_Host *host);
+static void abnormal_finished (struct NCR53c7x0_cmd *cmd, int result);
+static int disable (struct Scsi_Host *host);
+static int NCR53c7xx_run_tests (struct Scsi_Host *host);
+static irqreturn_t NCR53c7x0_intr(int irq, void *dev_id, struct pt_regs * regs);
+static void NCR53c7x0_intfly (struct Scsi_Host *host);
+static int ncr_halt (struct Scsi_Host *host);
+static void intr_phase_mismatch (struct Scsi_Host *host, struct NCR53c7x0_cmd 
+    *cmd);
+static void intr_dma (struct Scsi_Host *host, struct NCR53c7x0_cmd *cmd);
+static void print_dsa (struct Scsi_Host *host, u32 *dsa,
+    const char *prefix);
+static int print_insn (struct Scsi_Host *host, const u32 *insn,
+    const char *prefix, int kernel);
+
+static void NCR53c7xx_dsa_fixup (struct NCR53c7x0_cmd *cmd);
+static void NCR53c7x0_init_fixup (struct Scsi_Host *host);
+static int NCR53c7x0_dstat_sir_intr (struct Scsi_Host *host, struct 
+    NCR53c7x0_cmd *cmd);
+static void NCR53c7x0_soft_reset (struct Scsi_Host *host);
+
+/* Size of event list (per host adapter) */
+static int track_events = 0;
+static struct Scsi_Host *first_host = NULL;	/* Head of list of NCR boards */
+static Scsi_Host_Template *the_template = NULL;	
+
+/* NCR53c710 script handling code */
+
+#include "53c7xx_d.h"
+#ifdef A_int_debug_sync
+#define DEBUG_SYNC_INTR A_int_debug_sync
+#endif
+int NCR53c7xx_script_len = sizeof (SCRIPT);
+int NCR53c7xx_dsa_len = A_dsa_end + Ent_dsa_zero - Ent_dsa_code_template;
+#ifdef FORCE_DSA_ALIGNMENT
+int CmdPageStart = (0 - Ent_dsa_zero - sizeof(struct NCR53c7x0_cmd)) & 0xff;
+#endif
+
+static char *setup_strings[] =
+	{"","","","","","","",""};
+
+#define MAX_SETUP_STRINGS (sizeof(setup_strings) / sizeof(char *))
+#define SETUP_BUFFER_SIZE 200
+static char setup_buffer[SETUP_BUFFER_SIZE];
+static char setup_used[MAX_SETUP_STRINGS];
+
+void ncr53c7xx_setup (char *str, int *ints)
+{
+   int i;
+   char *p1, *p2;
+
+   p1 = setup_buffer;
+   *p1 = '\0';
+   if (str)
+      strncpy(p1, str, SETUP_BUFFER_SIZE - strlen(setup_buffer));
+   setup_buffer[SETUP_BUFFER_SIZE - 1] = '\0';
+   p1 = setup_buffer;
+   i = 0;
+   while (*p1 && (i < MAX_SETUP_STRINGS)) {
+      p2 = strchr(p1, ',');
+      if (p2) {
+         *p2 = '\0';
+         if (p1 != p2)
+            setup_strings[i] = p1;
+         p1 = p2 + 1;
+         i++;
+         }
+      else {
+         setup_strings[i] = p1;
+         break;
+         }
+      }
+   for (i=0; i<MAX_SETUP_STRINGS; i++)
+      setup_used[i] = 0;
+}
+
+
+/* check_setup_strings() returns index if key found, 0 if not
+ */
+
+static int check_setup_strings(char *key, int *flags, int *val, char *buf)
+{
+int x;
+char *cp;
+
+   for  (x=0; x<MAX_SETUP_STRINGS; x++) {
+      if (setup_used[x])
+         continue;
+      if (!strncmp(setup_strings[x], key, strlen(key)))
+         break;
+      if (!strncmp(setup_strings[x], "next", strlen("next")))
+         return 0;
+      }
+   if (x == MAX_SETUP_STRINGS)
+      return 0;
+   setup_used[x] = 1;
+   cp = setup_strings[x] + strlen(key);
+   *val = -1;
+   if (*cp != ':')
+      return ++x;
+   cp++;
+   if ((*cp >= '0') && (*cp <= '9')) {
+      *val = simple_strtoul(cp,NULL,0);
+      }
+   return ++x;
+}
+
+
+
+/*
+ * KNOWN BUGS :
+ * - There is some sort of conflict when the PPP driver is compiled with 
+ * 	support for 16 channels?
+ * 
+ * - On systems which predate the 1.3.x initialization order change,
+ *      the NCR driver will cause Cannot get free page messages to appear.  
+ *      These are harmless, but I don't know of an easy way to avoid them.
+ *
+ * - With OPTION_DISCONNECT, on two systems under unknown circumstances,
+ *	we get a PHASE MISMATCH with DSA set to zero (suggests that we 
+ *	are occurring somewhere in the reselection code) where 
+ *	DSP=some value DCMD|DBC=same value.  
+ * 	
+ *	Closer inspection suggests that we may be trying to execute
+ *	some portion of the DSA?
+ * scsi0 : handling residual transfer (+ 0 bytes from DMA FIFO)
+ * scsi0 : handling residual transfer (+ 0 bytes from DMA FIFO)
+ * scsi0 : no current command : unexpected phase MSGIN.
+ *         DSP=0x1c46cc, DCMD|DBC=0x1c46ac, DSA=0x0
+ *         DSPS=0x0, TEMP=0x1c3e70, DMODE=0x80
+ * scsi0 : DSP->
+ * 001c46cc : 0x001c46cc 0x00000000
+ * 001c46d4 : 0x001c5ea0 0x000011f8
+ *
+ *	Changed the print code in the phase_mismatch handler so
+ *	that we call print_lots to try to diagnose this.
+ *
+ */
+
+/* 
+ * Possible future direction of architecture for max performance :
+ *
+ * We're using a single start array for the NCR chip.  This is 
+ * sub-optimal, because we cannot add a command which would conflict with 
+ * an executing command to this start queue, and therefore must insert the 
+ * next command for a given I/T/L combination after the first has completed;
+ * incurring our interrupt latency between SCSI commands.
+ *
+ * To allow further pipelining of the NCR and host CPU operation, we want 
+ * to set things up so that immediately on termination of a command destined 
+ * for a given LUN, we get that LUN busy again.  
+ * 
+ * To do this, we need to add a 32 bit pointer to which is jumped to 
+ * on completion of a command.  If no new command is available, this 
+ * would point to the usual DSA issue queue select routine.
+ *
+ * If one were, it would point to a per-NCR53c7x0_cmd select routine 
+ * which starts execution immediately, inserting the command at the head 
+ * of the start queue if the NCR chip is selected or reselected.
+ *
+ * We would change so that we keep a list of outstanding commands 
+ * for each unit, rather than a single running_list.  We'd insert 
+ * a new command into the right running list; if the NCR didn't 
+ * have something running for that yet, we'd put it in the 
+ * start queue as well.  Some magic needs to happen to handle the 
+ * race condition between the first command terminating before the 
+ * new one is written.
+ *
+ * Potential for profiling : 
+ * Call do_gettimeofday(struct timeval *tv) to get 800ns resolution.
+ */
+
+
+/*
+ * TODO : 
+ * 1.  To support WIDE transfers, not much needs to happen.  We
+ *	should do CHMOVE instructions instead of MOVEs when
+ *	we have scatter/gather segments of uneven length.  When
+ * 	we do this, we need to handle the case where we disconnect
+ *	between segments.
+ * 
+ * 2.  Currently, when Icky things happen we do a FATAL().  Instead,
+ *     we want to do an integrity check on the parts of the NCR hostdata
+ *     structure which were initialized at boot time; FATAL() if that 
+ *     fails, and otherwise try to recover.  Keep track of how many
+ *     times this has happened within a single SCSI command; if it 
+ *     gets excessive, then FATAL().
+ *
+ * 3.  Parity checking is currently disabled, and a few things should 
+ *     happen here now that we support synchronous SCSI transfers :
+ *     1.  On soft-reset, we shoould set the EPC (Enable Parity Checking)
+ *	   and AAP (Assert SATN/ on parity error) bits in SCNTL0.
+ *	
+ *     2.  We should enable the parity interrupt in the SIEN0 register.
+ * 
+ *     3.  intr_phase_mismatch() needs to believe that message out is 
+ *	   always an "acceptable" phase to have a mismatch in.  If 
+ *	   the old phase was MSG_IN, we should send a MESSAGE PARITY 
+ *	   error.  If the old phase was something else, we should send
+ *	   a INITIATOR_DETECTED_ERROR message.  Note that this could
+ *	   cause a RESTORE POINTERS message; so we should handle that 
+ *	   correctly first.  Instead, we should probably do an 
+ *	   initiator_abort.
+ *
+ * 4.  MPEE bit of CTEST4 should be set so we get interrupted if 
+ *     we detect an error.
+ *
+ *  
+ * 5.  The initial code has been tested on the NCR53c810.  I don't 
+ *     have access to NCR53c700, 700-66 (Forex boards), NCR53c710
+ *     (NCR Pentium systems), NCR53c720, NCR53c820, or NCR53c825 boards to 
+ *     finish development on those platforms.
+ *
+ *     NCR53c820/825/720 - need to add wide transfer support, including WDTR 
+ *     		negotiation, programming of wide transfer capabilities
+ *		on reselection and table indirect selection.
+ *
+ *     NCR53c710 - need to add fatal interrupt or GEN code for 
+ *		command completion signaling.   Need to modify all 
+ *		SDID, SCID, etc. registers, and table indirect select code 
+ *		since these use bit fielded (ie 1<<target) instead of 
+ *		binary encoded target ids.  Need to accommodate
+ *		different register mappings, probably scan through
+ *		the SCRIPT code and change the non SFBR register operand
+ *		of all MOVE instructions.
+ *
+ *		It is rather worse than this actually, the 710 corrupts
+ *		both TEMP and DSA when you do a MOVE MEMORY.  This
+ *		screws you up all over the place.  MOVE MEMORY 4 with a
+ *		destination of DSA seems to work OK, which helps some.
+ *		Richard Hirst  richard@sleepie.demon.co.uk
+ * 
+ *     NCR53c700/700-66 - need to add code to refix addresses on 
+ *		every nexus change, eliminate all table indirect code,
+ *		very messy.
+ *
+ * 6.  The NCR53c7x0 series is very popular on other platforms that 
+ *     could be running Linux - ie, some high performance AMIGA SCSI 
+ *     boards use it.  
+ *	
+ *     So, I should include #ifdef'd code so that it is 
+ *     compatible with these systems.
+ *	
+ *     Specifically, the little Endian assumptions I made in my 
+ *     bit fields need to change, and if the NCR doesn't see memory
+ *     the right way, we need to provide options to reverse words
+ *     when the scripts are relocated.
+ *
+ * 7.  Use vremap() to access memory mapped boards.  
+ */
+
+/* 
+ * Allow for simultaneous existence of multiple SCSI scripts so we 
+ * can have a single driver binary for all of the family.
+ *
+ * - one for NCR53c700 and NCR53c700-66 chips	(not yet supported)
+ * - one for rest (only the NCR53c810, 815, 820, and 825 are currently 
+ *	supported)
+ * 
+ * So that we only need two SCSI scripts, we need to modify things so
+ * that we fixup register accesses in READ/WRITE instructions, and 
+ * we'll also have to accommodate the bit vs. binary encoding of IDs
+ * with the 7xx chips.
+ */
+
+#define ROUNDUP(adr,type)	\
+  ((void *) (((long) (adr) + sizeof(type) - 1) & ~(sizeof(type) - 1)))
+
+
+/*
+ * Function: issue_to_cmd
+ *
+ * Purpose: convert jump instruction in issue array to NCR53c7x0_cmd
+ *	structure pointer.  
+ *
+ * Inputs; issue - pointer to start of NOP or JUMP instruction
+ *	in issue array.
+ *
+ * Returns: pointer to command on success; 0 if opcode is NOP.
+ */
+
+static inline struct NCR53c7x0_cmd *
+issue_to_cmd (struct Scsi_Host *host, struct NCR53c7x0_hostdata *hostdata,
+    u32 *issue)
+{
+    return (issue[0] != hostdata->NOP_insn) ? 
+    /* 
+     * If the IF TRUE bit is set, it's a JUMP instruction.  The
+     * operand is a bus pointer to the dsa_begin routine for this DSA.  The
+     * dsa field of the NCR53c7x0_cmd structure starts with the 
+     * DSA code template.  By converting to a virtual address,
+     * subtracting the code template size, and offset of the 
+     * dsa field, we end up with a pointer to the start of the 
+     * structure (alternatively, we could use the 
+     * dsa_cmnd field, an anachronism from when we weren't
+     * sure what the relationship between the NCR structures
+     * and host structures were going to be.
+     */
+	(struct NCR53c7x0_cmd *) ((char *) bus_to_virt (issue[1]) - 
+	    (hostdata->E_dsa_code_begin - hostdata->E_dsa_code_template) -
+	    offsetof(struct NCR53c7x0_cmd, dsa)) 
+    /* If the IF TRUE bit is not set, it's a NOP */
+	: NULL;
+}
+
+
+/* 
+ * FIXME: we should junk these, in favor of synchronous_want and 
+ * wide_want in the NCR53c7x0_hostdata structure.
+ */
+
+/* Template for "preferred" synchronous transfer parameters. */
+
+static const unsigned char sdtr_message[] = {
+#ifdef CONFIG_SCSI_NCR53C7xx_FAST
+    EXTENDED_MESSAGE, 3 /* length */, EXTENDED_SDTR, 25 /* *4ns */, 8 /* off */
+#else
+    EXTENDED_MESSAGE, 3 /* length */, EXTENDED_SDTR, 50 /* *4ns */, 8 /* off */ 
+#endif
+};
+
+/* Template to request asynchronous transfers */
+
+static const unsigned char async_message[] = {
+    EXTENDED_MESSAGE, 3 /* length */, EXTENDED_SDTR, 0, 0 /* asynchronous */
+};
+
+/* Template for "preferred" WIDE transfer parameters */
+
+static const unsigned char wdtr_message[] = {
+    EXTENDED_MESSAGE, 2 /* length */, EXTENDED_WDTR, 1 /* 2^1 bytes */
+};
+
+#if 0
+/*
+ * Function : struct Scsi_Host *find_host (int host)
+ * 
+ * Purpose : KGDB support function which translates a host number 
+ * 	to a host structure. 
+ *
+ * Inputs : host - number of SCSI host
+ *
+ * Returns : NULL on failure, pointer to host structure on success.
+ */
+
+static struct Scsi_Host *
+find_host (int host) {
+    struct Scsi_Host *h;
+    for (h = first_host; h && h->host_no != host; h = h->next);
+    if (!h) {
+	printk (KERN_ALERT "scsi%d not found\n", host);
+	return NULL;
+    } else if (h->hostt != the_template) {
+	printk (KERN_ALERT "scsi%d is not a NCR board\n", host);
+	return NULL;
+    }
+    return h;
+}
+
+#if 0
+/*
+ * Function : request_synchronous (int host, int target)
+ * 
+ * Purpose : KGDB interface which will allow us to negotiate for 
+ * 	synchronous transfers.  This ill be replaced with a more 
+ * 	integrated function; perhaps a new entry in the scsi_host 
+ *	structure, accessible via an ioctl() or perhaps /proc/scsi.
+ *
+ * Inputs : host - number of SCSI host; target - number of target.
+ *
+ * Returns : 0 when negotiation has been setup for next SCSI command,
+ *	-1 on failure.
+ */
+
+static int
+request_synchronous (int host, int target) {
+    struct Scsi_Host *h;
+    struct NCR53c7x0_hostdata *hostdata;
+    unsigned long flags;
+    if (target < 0) {
+	printk (KERN_ALERT "target %d is bogus\n", target);
+	return -1;
+    }
+    if (!(h = find_host (host)))
+	return -1;
+    else if (h->this_id == target) {
+	printk (KERN_ALERT "target %d is host ID\n", target);
+	return -1;
+    } 
+    else if (target > h->max_id) {
+	printk (KERN_ALERT "target %d exceeds maximum of %d\n", target,
+	    h->max_id);
+	return -1;
+    }
+    hostdata = (struct NCR53c7x0_hostdata *)h->hostdata[0];
+
+    local_irq_save(flags);
+    if (hostdata->initiate_sdtr & (1 << target)) {
+	local_irq_restore(flags);
+	printk (KERN_ALERT "target %d already doing SDTR\n", target);
+	return -1;
+    } 
+    hostdata->initiate_sdtr |= (1 << target);
+    local_irq_restore(flags);
+    return 0;
+}
+#endif
+
+/*
+ * Function : request_disconnect (int host, int on_or_off)
+ * 
+ * Purpose : KGDB support function, tells us to allow or disallow 
+ *	disconnections.
+ *
+ * Inputs : host - number of SCSI host; on_or_off - non-zero to allow,
+ *	zero to disallow.
+ *
+ * Returns : 0 on success, *	-1 on failure.
+ */
+
+static int 
+request_disconnect (int host, int on_or_off) {
+    struct Scsi_Host *h;
+    struct NCR53c7x0_hostdata *hostdata;
+    if (!(h = find_host (host)))
+	return -1;
+    hostdata = (struct NCR53c7x0_hostdata *) h->hostdata[0];
+    if (on_or_off) 
+	hostdata->options |= OPTION_DISCONNECT;
+    else
+	hostdata->options &= ~OPTION_DISCONNECT;
+    return 0;
+}
+#endif
+
+/*
+ * Function : static void NCR53c7x0_driver_init (struct Scsi_Host *host)
+ *
+ * Purpose : Initialize internal structures, as required on startup, or 
+ *	after a SCSI bus reset.
+ * 
+ * Inputs : host - pointer to this host adapter's structure
+ */
+
+static void 
+NCR53c7x0_driver_init (struct Scsi_Host *host) {
+    struct NCR53c7x0_hostdata *hostdata = (struct NCR53c7x0_hostdata *)
+	host->hostdata[0];
+    int i, j;
+    u32 *ncrcurrent;
+
+    for (i = 0; i < 16; ++i) {
+	hostdata->request_sense[i] = 0;
+    	for (j = 0; j < 8; ++j) 
+	    hostdata->busy[i][j] = 0;
+	set_synchronous (host, i, /* sxfer */ 0, hostdata->saved_scntl3, 0);
+    }
+    hostdata->issue_queue = NULL;
+    hostdata->running_list = hostdata->finished_queue = 
+	hostdata->ncrcurrent = NULL;
+    for (i = 0, ncrcurrent = (u32 *) hostdata->schedule; 
+	i < host->can_queue; ++i, ncrcurrent += 2) {
+	ncrcurrent[0] = hostdata->NOP_insn;
+	ncrcurrent[1] = 0xdeadbeef;
+    }
+    ncrcurrent[0] = ((DCMD_TYPE_TCI|DCMD_TCI_OP_JUMP) << 24) | DBC_TCI_TRUE;
+    ncrcurrent[1] = (u32) virt_to_bus (hostdata->script) +
+	hostdata->E_wait_reselect;
+    hostdata->reconnect_dsa_head = 0;
+    hostdata->addr_reconnect_dsa_head = (u32) 
+	virt_to_bus((void *) &(hostdata->reconnect_dsa_head));
+    hostdata->expecting_iid = 0;
+    hostdata->expecting_sto = 0;
+    if (hostdata->options & OPTION_ALWAYS_SYNCHRONOUS) 
+	hostdata->initiate_sdtr = 0xffff; 
+    else
+    	hostdata->initiate_sdtr = 0;
+    hostdata->talked_to = 0;
+    hostdata->idle = 1;
+}
+
+/* 
+ * Function : static int clock_to_ccf_710 (int clock)
+ *
+ * Purpose :  Return the clock conversion factor for a given SCSI clock.
+ *
+ * Inputs : clock - SCSI clock expressed in Hz.
+ *
+ * Returns : ccf on success, -1 on failure.
+ */
+
+static int 
+clock_to_ccf_710 (int clock) {
+    if (clock <= 16666666)
+	return -1;
+    if (clock <= 25000000)
+	return 2; 	/* Divide by 1.0 */
+    else if (clock <= 37500000)
+	return 1; 	/* Divide by 1.5 */
+    else if (clock <= 50000000)
+	return 0;	/* Divide by 2.0 */
+    else if (clock <= 66000000)
+	return 3;	/* Divide by 3.0 */
+    else 
+	return -1;
+}
+    
+/* 
+ * Function : static int NCR53c7x0_init (struct Scsi_Host *host)
+ *
+ * Purpose :  initialize the internal structures for a given SCSI host
+ *
+ * Inputs : host - pointer to this host adapter's structure
+ *
+ * Preconditions : when this function is called, the chip_type 
+ * 	field of the hostdata structure MUST have been set.
+ *
+ * Returns : 0 on success, -1 on failure.
+ */
+
+int 
+NCR53c7x0_init (struct Scsi_Host *host) {
+    NCR53c7x0_local_declare();
+    int i, ccf;
+    unsigned char revision;
+    struct NCR53c7x0_hostdata *hostdata = (struct NCR53c7x0_hostdata *)
+	host->hostdata[0];
+    /* 
+     * There are some things which we need to know about in order to provide
+     * a semblance of support.  Print 'em if they aren't what we expect, 
+     * otherwise don't add to the noise.
+     * 
+     * -1 means we don't know what to expect.
+     */
+    int val, flags;
+    char buf[32];
+    int expected_id = -1;
+    int expected_clock = -1;
+    int uninitialized = 0;
+#ifdef NO_IO_SPACE
+    int expected_mapping = OPTION_MEMORY_MAPPED;
+#else
+    int expected_mapping = OPTION_IO_MAPPED;
+#endif
+    for (i=0;i<7;i++)
+	hostdata->valid_ids[i] = 1;	/* Default all ID's to scan */
+
+    /* Parse commandline flags */
+    if (check_setup_strings("noasync",&flags,&val,buf))
+    {
+	hostdata->options |= OPTION_NO_ASYNC;
+	hostdata->options &= ~(OPTION_SYNCHRONOUS | OPTION_ALWAYS_SYNCHRONOUS);
+    }
+
+    if (check_setup_strings("nosync",&flags,&val,buf))
+    {
+	hostdata->options &= ~(OPTION_SYNCHRONOUS | OPTION_ALWAYS_SYNCHRONOUS);
+    }
+
+    if (check_setup_strings("nodisconnect",&flags,&val,buf))
+	hostdata->options &= ~OPTION_DISCONNECT;
+
+    if (check_setup_strings("validids",&flags,&val,buf))
+    {
+	for (i=0;i<7;i++) 
+		hostdata->valid_ids[i] = val & (1<<i);
+    }
+ 
+    if  ((i = check_setup_strings("next",&flags,&val,buf)))
+    {
+	while (i)
+		setup_used[--i] = 1;
+    }
+
+    if (check_setup_strings("opthi",&flags,&val,buf))
+	hostdata->options = (long long)val << 32;
+    if (check_setup_strings("optlo",&flags,&val,buf))
+	hostdata->options |= val;
+
+    NCR53c7x0_local_setup(host);
+    switch (hostdata->chip) {
+    case 710:
+    case 770:
+    	hostdata->dstat_sir_intr = NCR53c7x0_dstat_sir_intr;
+    	hostdata->init_save_regs = NULL;
+    	hostdata->dsa_fixup = NCR53c7xx_dsa_fixup;
+    	hostdata->init_fixup = NCR53c7x0_init_fixup;
+    	hostdata->soft_reset = NCR53c7x0_soft_reset;
+	hostdata->run_tests = NCR53c7xx_run_tests;
+	expected_clock = hostdata->scsi_clock;
+	expected_id = 7;
+    	break;
+    default:
+	printk ("scsi%d : chip type of %d is not supported yet, detaching.\n",
+	    host->host_no, hostdata->chip);
+	scsi_unregister (host);
+	return -1;
+    }
+
+    /* Assign constants accessed by NCR */
+    hostdata->NCR53c7xx_zero = 0;			
+    hostdata->NCR53c7xx_msg_reject = MESSAGE_REJECT;
+    hostdata->NCR53c7xx_msg_abort = ABORT;
+    hostdata->NCR53c7xx_msg_nop = NOP;
+    hostdata->NOP_insn = (DCMD_TYPE_TCI|DCMD_TCI_OP_JUMP) << 24;
+    if (expected_mapping == -1 || 
+	(hostdata->options & (OPTION_MEMORY_MAPPED)) != 
+	(expected_mapping & OPTION_MEMORY_MAPPED))
+	printk ("scsi%d : using %s mapped access\n", host->host_no, 
+	    (hostdata->options & OPTION_MEMORY_MAPPED) ? "memory" : 
+	    "io");
+
+    hostdata->dmode = (hostdata->chip == 700 || hostdata->chip == 70066) ? 
+	DMODE_REG_00 : DMODE_REG_10;
+    hostdata->istat = ((hostdata->chip / 100) == 8) ? 
+    	ISTAT_REG_800 : ISTAT_REG_700;
+
+/* We have to assume that this may be the first access to the chip, so
+ * we must set EA in DCNTL. */
+
+    NCR53c7x0_write8 (DCNTL_REG, DCNTL_10_EA|DCNTL_10_COM);
+
+
+/* Only the ISTAT register is readable when the NCR is running, so make 
+   sure it's halted. */
+    ncr_halt(host);
+
+/* 
+ * XXX - the NCR53c700 uses bitfielded registers for SCID, SDID, etc,
+ *	as does the 710 with one bit per SCSI ID.  Conversely, the NCR
+ * 	uses a normal, 3 bit binary representation of these values.
+ *
+ * Get the rest of the NCR documentation, and FIND OUT where the change
+ * was.
+ */
+
+#if 0
+	/* May not be able to do this - chip my not have been set up yet */
+	tmp = hostdata->this_id_mask = NCR53c7x0_read8(SCID_REG);
+	for (host->this_id = 0; tmp != 1; tmp >>=1, ++host->this_id);
+#else
+	host->this_id = 7;
+#endif
+
+/*
+ * Note : we should never encounter a board setup for ID0.  So,
+ * 	if we see ID0, assume that it was uninitialized and set it
+ * 	to the industry standard 7.
+ */
+    if (!host->this_id) {
+	printk("scsi%d : initiator ID was %d, changing to 7\n",
+	    host->host_no, host->this_id);
+	host->this_id = 7;
+	hostdata->this_id_mask = 1 << 7;
+	uninitialized = 1;
+    };
+
+    if (expected_id == -1 || host->this_id != expected_id)
+    	printk("scsi%d : using initiator ID %d\n", host->host_no,
+    	    host->this_id);
+
+    /*
+     * Save important registers to allow a soft reset.
+     */
+
+    /*
+     * CTEST7 controls cache snooping, burst mode, and support for 
+     * external differential drivers.  This isn't currently used - the
+     * default value may not be optimal anyway.
+     * Even worse, it may never have been set up since reset.
+     */
+    hostdata->saved_ctest7 = NCR53c7x0_read8(CTEST7_REG) & CTEST7_SAVE;
+    revision = (NCR53c7x0_read8(CTEST8_REG) & 0xF0) >> 4;
+    switch (revision) {
+	case 1: revision = 0;    break;
+	case 2: revision = 1;    break;
+	case 4: revision = 2;    break;
+	case 8: revision = 3;    break;
+	default: revision = 255; break;
+    }
+    printk("scsi%d: Revision 0x%x\n",host->host_no,revision);
+
+    if ((revision == 0 || revision == 255) && (hostdata->options & (OPTION_SYNCHRONOUS|OPTION_DISCONNECT|OPTION_ALWAYS_SYNCHRONOUS)))
+    {
+	printk ("scsi%d: Disabling sync working and disconnect/reselect\n",
+							host->host_no);
+	hostdata->options &= ~(OPTION_SYNCHRONOUS|OPTION_DISCONNECT|OPTION_ALWAYS_SYNCHRONOUS);
+    }
+
+    /*
+     * On NCR53c700 series chips, DCNTL controls the SCSI clock divisor,
+     * on 800 series chips, it allows for a totem-pole IRQ driver.
+     * NOTE saved_dcntl currently overwritten in init function.
+     * The value read here may be garbage anyway, MVME16x board at least
+     * does not initialise chip if kernel arrived via tftp.
+     */
+
+    hostdata->saved_dcntl = NCR53c7x0_read8(DCNTL_REG);
+
+    /*
+     * DMODE controls DMA burst length, and on 700 series chips,
+     * 286 mode and bus width  
+     * NOTE:  On MVME16x, chip may have been reset, so this could be a
+     * power-on/reset defau