aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/scsi/53c700.c
blob: 4958c3b93c300a45cc40891d65242fd4ed1587ee (plain) (tree)
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758

































































































































                                                                               
                         









































                                                                                      


































































                                                                            



















                                                                        
                                                                                                                                             
























































                                                                                              
 




                                                                 









                                                              
 



                                           





                                                                      
                                                              









                                                                                                      
                                                
                                                  

                                                  
                                     
                                                                                        












                                                                                          
                         


                                                      
                                                        



                                                    
                              



                                                                            
                          



                                                                                                                     
                                             











































































































































































































































































































































































































































                                                                                                                                                     

                                                         






















                                                                                            
                                               




























                                                                                 
                                       


















                                                                                                                    

                                                                                                

                                                                                                 
                                                                       


                                                                            


                                                                         




















                                                                                    
                                               













































                                                                                             

                                                                                                         






























































                                                                                                                                                


                                                                                      


                                                                                                        
                                                                                       






                                                                              
                                                                        

                                                                      

                                                                      

















































                                                                                                 


                                                                       


                                                                                

                                                                               










































































































































































































































































































                                                                                                                                                                                                                                                                                                 
                                                         





                                                                              


                                                                        






                                                                                  
                                                    

































































































































































































































































































































                                                                                                                                                                                                                                                      
                                                              
                                                  

                                                                


                                                                        

                                                               




















                                                                           
                                                                
                                                                                        

                                                                             









                                                                                       


                                                                               

         
                                                        

                                               

                                                                        


































































































                                                                                       

                                                                































                                                                                 

                                                                      
                                
 


                                                                   

                                                    



                                                              
 

                                                      
 


                                                      
 



                                                                       

                                                      



                       

                                          
                                                                              

                                

                                                    

                                                      


                                                      















































































































                                                                              
                                                                 













                                                                                      
                                                                                      













































                                                                                        
/* -*- mode: c; c-basic-offset: 8 -*- */

/* NCR (or Symbios) 53c700 and 53c700-66 Driver
 *
 * Copyright (C) 2001 by James.Bottomley@HansenPartnership.com
**-----------------------------------------------------------------------------
**  
**  This program is free software; you can redistribute it and/or modify
**  it under the terms of the GNU General Public License as published by
**  the Free Software Foundation; either version 2 of the License, or
**  (at your option) any later version.
**
**  This program is distributed in the hope that it will be useful,
**  but WITHOUT ANY WARRANTY; without even the implied warranty of
**  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
**  GNU General Public License for more details.
**
**  You should have received a copy of the GNU General Public License
**  along with this program; if not, write to the Free Software
**  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
**-----------------------------------------------------------------------------
 */

/* Notes:
 *
 * This driver is designed exclusively for these chips (virtually the
 * earliest of the scripts engine chips).  They need their own drivers
 * because they are missing so many of the scripts and snazzy register
 * features of their elder brothers (the 710, 720 and 770).
 *
 * The 700 is the lowliest of the line, it can only do async SCSI.
 * The 700-66 can at least do synchronous SCSI up to 10MHz.
 * 
 * The 700 chip has no host bus interface logic of its own.  However,
 * it is usually mapped to a location with well defined register
 * offsets.  Therefore, if you can determine the base address and the
 * irq your board incorporating this chip uses, you can probably use
 * this driver to run it (although you'll probably have to write a
 * minimal wrapper for the purpose---see the NCR_D700 driver for
 * details about how to do this).
 *
 *
 * TODO List:
 *
 * 1. Better statistics in the proc fs
 *
 * 2. Implement message queue (queues SCSI messages like commands) and make
 *    the abort and device reset functions use them.
 * */

/* CHANGELOG
 *
 * Version 2.8
 *
 * Fixed bad bug affecting tag starvation processing (previously the
 * driver would hang the system if too many tags starved.  Also fixed
 * bad bug having to do with 10 byte command processing and REQUEST
 * SENSE (the command would loop forever getting a transfer length
 * mismatch in the CMD phase).
 *
 * Version 2.7
 *
 * Fixed scripts problem which caused certain devices (notably CDRWs)
 * to hang on initial INQUIRY.  Updated NCR_700_readl/writel to use
 * __raw_readl/writel for parisc compatibility (Thomas
 * Bogendoerfer). Added missing SCp->request_bufflen initialisation
 * for sense requests (Ryan Bradetich).
 *
 * Version 2.6
 *
 * Following test of the 64 bit parisc kernel by Richard Hirst,
 * several problems have now been corrected.  Also adds support for
 * consistent memory allocation.
 *
 * Version 2.5
 * 
 * More Compatibility changes for 710 (now actually works).  Enhanced
 * support for odd clock speeds which constrain SDTR negotiations.
 * correct cacheline separation for scsi messages and status for
 * incoherent architectures.  Use of the pci mapping functions on
 * buffers to begin support for 64 bit drivers.
 *
 * Version 2.4
 *
 * Added support for the 53c710 chip (in 53c700 emulation mode only---no 
 * special 53c710 instructions or registers are used).
 *
 * Version 2.3
 *
 * More endianness/cache coherency changes.
 *
 * Better bad device handling (handles devices lying about tag
 * queueing support and devices which fail to provide sense data on
 * contingent allegiance conditions)
 *
 * Many thanks to Richard Hirst <rhirst@linuxcare.com> for patiently
 * debugging this driver on the parisc architecture and suggesting
 * many improvements and bug fixes.
 *
 * Thanks also go to Linuxcare Inc. for providing several PARISC
 * machines for me to debug the driver on.
 *
 * Version 2.2
 *
 * Made the driver mem or io mapped; added endian invariance; added
 * dma cache flushing operations for architectures which need it;
 * added support for more varied clocking speeds.
 *
 * Version 2.1
 *
 * Initial modularisation from the D700.  See NCR_D700.c for the rest of
 * the changelog.
 * */
#define NCR_700_VERSION "2.8"

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <asm/dma.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/byteorder.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_spi.h>

#include "53c700.h"

/* NOTE: For 64 bit drivers there are points in the code where we use
 * a non dereferenceable pointer to point to a structure in dma-able
 * memory (which is 32 bits) so that we can use all of the structure
 * operations but take the address at the end.  This macro allows us
 * to truncate the 64 bit pointer down to 32 bits without the compiler
 * complaining */
#define to32bit(x)	((__u32)((unsigned long)(x)))

#ifdef NCR_700_DEBUG
#define STATIC
#else
#define STATIC static
#endif

MODULE_AUTHOR("James Bottomley");
MODULE_DESCRIPTION("53c700 and 53c700-66 Driver");
MODULE_LICENSE("GPL");

/* This is the script */
#include "53c700_d.h"


STATIC int NCR_700_queuecommand(struct scsi_cmnd *, void (*done)(struct scsi_cmnd *));
STATIC int NCR_700_abort(struct scsi_cmnd * SCpnt);
STATIC int NCR_700_bus_reset(struct scsi_cmnd * SCpnt);
STATIC int NCR_700_host_reset(struct scsi_cmnd * SCpnt);
STATIC void NCR_700_chip_setup(struct Scsi_Host *host);
STATIC void NCR_700_chip_reset(struct Scsi_Host *host);
STATIC int NCR_700_slave_configure(struct scsi_device *SDpnt);
STATIC void NCR_700_slave_destroy(struct scsi_device *SDpnt);
static int NCR_700_change_queue_depth(struct scsi_device *SDpnt, int depth);
static int NCR_700_change_queue_type(struct scsi_device *SDpnt, int depth);

STATIC struct device_attribute *NCR_700_dev_attrs[];

STATIC struct scsi_transport_template *NCR_700_transport_template = NULL;

static char *NCR_700_phase[] = {
	"",
	"after selection",
	"before command phase",
	"after command phase",
	"after status phase",
	"after data in phase",
	"after data out phase",
	"during data phase",
};

static char *NCR_700_condition[] = {
	"",
	"NOT MSG_OUT",
	"UNEXPECTED PHASE",
	"NOT MSG_IN",
	"UNEXPECTED MSG",
	"MSG_IN",
	"SDTR_MSG RECEIVED",
	"REJECT_MSG RECEIVED",
	"DISCONNECT_MSG RECEIVED",
	"MSG_OUT",
	"DATA_IN",
	
};

static char *NCR_700_fatal_messages[] = {
	"unexpected message after reselection",
	"still MSG_OUT after message injection",
	"not MSG_IN after selection",
	"Illegal message length received",
};

static char *NCR_700_SBCL_bits[] = {
	"IO ",
	"CD ",
	"MSG ",
	"ATN ",
	"SEL ",
	"BSY ",
	"ACK ",
	"REQ ",
};

static char *NCR_700_SBCL_to_phase[] = {
	"DATA_OUT",
	"DATA_IN",
	"CMD_OUT",
	"STATE",
	"ILLEGAL PHASE",
	"ILLEGAL PHASE",
	"MSG OUT",
	"MSG IN",
};

/* This translates the SDTR message offset and period to a value
 * which can be loaded into the SXFER_REG.
 *
 * NOTE: According to SCSI-2, the true transfer period (in ns) is
 *       actually four times this period value */
static inline __u8
NCR_700_offset_period_to_sxfer(struct NCR_700_Host_Parameters *hostdata,
			       __u8 offset, __u8 period)
{
	int XFERP;

	__u8 min_xferp = (hostdata->chip710
			  ? NCR_710_MIN_XFERP : NCR_700_MIN_XFERP);
	__u8 max_offset = (hostdata->chip710
			   ? NCR_710_MAX_OFFSET : NCR_700_MAX_OFFSET);

	if(offset == 0)
		return 0;

	if(period < hostdata->min_period) {
		printk(KERN_WARNING "53c700: Period %dns is less than this chip's minimum, setting to %d\n", period*4, NCR_700_MIN_PERIOD*4);
		period = hostdata->min_period;
	}
	XFERP = (period*4 * hostdata->sync_clock)/1000 - 4;
	if(offset > max_offset) {
		printk(KERN_WARNING "53c700: Offset %d exceeds chip maximum, setting to %d\n",
		       offset, max_offset);
		offset = max_offset;
	}
	if(XFERP < min_xferp) {
		printk(KERN_WARNING "53c700: XFERP %d is less than minium, setting to %d\n",
		       XFERP,  min_xferp);
		XFERP =  min_xferp;
	}
	return (offset & 0x0f) | (XFERP & 0x07)<<4;
}

static inline __u8
NCR_700_get_SXFER(struct scsi_device *SDp)
{
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)SDp->host->hostdata[0];

	return NCR_700_offset_period_to_sxfer(hostdata,
					      spi_offset(SDp->sdev_target),
					      spi_period(SDp->sdev_target));
}

struct Scsi_Host *
NCR_700_detect(struct scsi_host_template *tpnt,
	       struct NCR_700_Host_Parameters *hostdata, struct device *dev)
{
	dma_addr_t pScript, pSlots;
	__u8 *memory;
	__u32 *script;
	struct Scsi_Host *host;
	static int banner = 0;
	int j;

	if(tpnt->sdev_attrs == NULL)
		tpnt->sdev_attrs = NCR_700_dev_attrs;

	memory = dma_alloc_noncoherent(hostdata->dev, TOTAL_MEM_SIZE,
				       &pScript, GFP_KERNEL);
	if(memory == NULL) {
		printk(KERN_ERR "53c700: Failed to allocate memory for driver, detatching\n");
		return NULL;
	}

	script = (__u32 *)memory;
	hostdata->msgin = memory + MSGIN_OFFSET;
	hostdata->msgout = memory + MSGOUT_OFFSET;
	hostdata->status = memory + STATUS_OFFSET;
	/* all of these offsets are L1_CACHE_BYTES separated.  It is fatal
	 * if this isn't sufficient separation to avoid dma flushing issues */
	BUG_ON(!dma_is_consistent(pScript) && L1_CACHE_BYTES < dma_get_cache_alignment());
	hostdata->slots = (struct NCR_700_command_slot *)(memory + SLOTS_OFFSET);
	hostdata->dev = dev;

	pSlots = pScript + SLOTS_OFFSET;

	/* Fill in the missing routines from the host template */
	tpnt->queuecommand = NCR_700_queuecommand;
	tpnt->eh_abort_handler = NCR_700_abort;
	tpnt->eh_bus_reset_handler = NCR_700_bus_reset;
	tpnt->eh_host_reset_handler = NCR_700_host_reset;
	tpnt->can_queue = NCR_700_COMMAND_SLOTS_PER_HOST;
	tpnt->sg_tablesize = NCR_700_SG_SEGMENTS;
	tpnt->cmd_per_lun = NCR_700_CMD_PER_LUN;
	tpnt->use_clustering = ENABLE_CLUSTERING;
	tpnt->slave_configure = NCR_700_slave_configure;
	tpnt->slave_destroy = NCR_700_slave_destroy;
	tpnt->change_queue_depth = NCR_700_change_queue_depth;
	tpnt->change_queue_type = NCR_700_change_queue_type;

	if(tpnt->name == NULL)
		tpnt->name = "53c700";
	if(tpnt->proc_name == NULL)
		tpnt->proc_name = "53c700";

	host = scsi_host_alloc(tpnt, 4);
	if (!host)
		return NULL;
	memset(hostdata->slots, 0, sizeof(struct NCR_700_command_slot)
	       * NCR_700_COMMAND_SLOTS_PER_HOST);
	for (j = 0; j < NCR_700_COMMAND_SLOTS_PER_HOST; j++) {
		dma_addr_t offset = (dma_addr_t)((unsigned long)&hostdata->slots[j].SG[0]
					  - (unsigned long)&hostdata->slots[0].SG[0]);
		hostdata->slots[j].pSG = (struct NCR_700_SG_List *)((unsigned long)(pSlots + offset));
		if(j == 0)
			hostdata->free_list = &hostdata->slots[j];
		else
			hostdata->slots[j-1].ITL_forw = &hostdata->slots[j];
		hostdata->slots[j].state = NCR_700_SLOT_FREE;
	}

	for (j = 0; j < ARRAY_SIZE(SCRIPT); j++)
		script[j] = bS_to_host(SCRIPT[j]);

	/* adjust all labels to be bus physical */
	for (j = 0; j < PATCHES; j++)
		script[LABELPATCHES[j]] = bS_to_host(pScript + SCRIPT[LABELPATCHES[j]]);
	/* now patch up fixed addresses. */
	script_patch_32(script, MessageLocation,
			pScript + MSGOUT_OFFSET);
	script_patch_32(script, StatusAddress,
			pScript + STATUS_OFFSET);
	script_patch_32(script, ReceiveMsgAddress,
			pScript + MSGIN_OFFSET);

	hostdata->script = script;
	hostdata->pScript = pScript;
	dma_sync_single_for_device(hostdata->dev, pScript, sizeof(SCRIPT), DMA_TO_DEVICE);
	hostdata->state = NCR_700_HOST_FREE;
	hostdata->cmd = NULL;
	host->max_id = 8;
	host->max_lun = NCR_700_MAX_LUNS;
	BUG_ON(NCR_700_transport_template == NULL);
	host->transportt = NCR_700_transport_template;
	host->unique_id = (unsigned long)hostdata->base;
	hostdata->eh_complete = NULL;
	host->hostdata[0] = (unsigned long)hostdata;
	/* kick the chip */
	NCR_700_writeb(0xff, host, CTEST9_REG);
	if (hostdata->chip710)
		hostdata->rev = (NCR_700_readb(host, CTEST8_REG)>>4) & 0x0f;
	else
		hostdata->rev = (NCR_700_readb(host, CTEST7_REG)>>4) & 0x0f;
	hostdata->fast = (NCR_700_readb(host, CTEST9_REG) == 0);
	if (banner == 0) {
		printk(KERN_NOTICE "53c700: Version " NCR_700_VERSION " By James.Bottomley@HansenPartnership.com\n");
		banner = 1;
	}
	printk(KERN_NOTICE "scsi%d: %s rev %d %s\n", host->host_no,
	       hostdata->chip710 ? "53c710" :
	       (hostdata->fast ? "53c700-66" : "53c700"),
	       hostdata->rev, hostdata->differential ?
	       "(Differential)" : "");
	/* reset the chip */
	NCR_700_chip_reset(host);

	if (scsi_add_host(host, dev)) {
		dev_printk(KERN_ERR, dev, "53c700: scsi_add_host failed\n");
		scsi_host_put(host);
		return NULL;
	}

	spi_signalling(host) = hostdata->differential ? SPI_SIGNAL_HVD :
		SPI_SIGNAL_SE;

	return host;
}

int
NCR_700_release(struct Scsi_Host *host)
{
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)host->hostdata[0];

	dma_free_noncoherent(hostdata->dev, TOTAL_MEM_SIZE,
			       hostdata->script, hostdata->pScript);
	return 1;
}

static inline __u8
NCR_700_identify(int can_disconnect, __u8 lun)
{
	return IDENTIFY_BASE |
		((can_disconnect) ? 0x40 : 0) |
		(lun & NCR_700_LUN_MASK);
}

/*
 * Function : static int data_residual (Scsi_Host *host)
 *
 * Purpose : return residual data count of what's in the chip.  If you
 * really want to know what this function is doing, it's almost a
 * direct transcription of the algorithm described in the 53c710
 * guide, except that the DBC and DFIFO registers are only 6 bits
 * wide on a 53c700.
 *
 * Inputs : host - SCSI host */
static inline int
NCR_700_data_residual (struct Scsi_Host *host) {
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)host->hostdata[0];
	int count, synchronous = 0;
	unsigned int ddir;

	if(hostdata->chip710) {
		count = ((NCR_700_readb(host, DFIFO_REG) & 0x7f) -
			 (NCR_700_readl(host, DBC_REG) & 0x7f)) & 0x7f;
	} else {
		count = ((NCR_700_readb(host, DFIFO_REG) & 0x3f) -
			 (NCR_700_readl(host, DBC_REG) & 0x3f)) & 0x3f;
	}
	
	if(hostdata->fast)
		synchronous = NCR_700_readb(host, SXFER_REG) & 0x0f;
	
	/* get the data direction */
	ddir = NCR_700_readb(host, CTEST0_REG) & 0x01;

	if (ddir) {
		/* Receive */
		if (synchronous) 
			count += (NCR_700_readb(host, SSTAT2_REG) & 0xf0) >> 4;
		else
			if (NCR_700_readb(host, SSTAT1_REG) & SIDL_REG_FULL)
				++count;
	} else {
		/* Send */
		__u8 sstat = NCR_700_readb(host, SSTAT1_REG);
		if (sstat & SODL_REG_FULL)
			++count;
		if (synchronous && (sstat & SODR_REG_FULL))
			++count;
	}
#ifdef NCR_700_DEBUG
	if(count)
		printk("RESIDUAL IS %d (ddir %d)\n", count, ddir);
#endif
	return count;
}

/* print out the SCSI wires and corresponding phase from the SBCL register
 * in the chip */
static inline char *
sbcl_to_string(__u8 sbcl)
{
	int i;
	static char ret[256];

	ret[0]='\0';
	for(i=0; i<8; i++) {
		if((1<<i) & sbcl) 
			strcat(ret, NCR_700_SBCL_bits[i]);
	}
	strcat(ret, NCR_700_SBCL_to_phase[sbcl & 0x07]);
	return ret;
}

static inline __u8
bitmap_to_number(__u8 bitmap)
{
	__u8 i;

	for(i=0; i<8 && !(bitmap &(1<<i)); i++)
		;
	return i;
}

/* Pull a slot off the free list */
STATIC struct NCR_700_command_slot *
find_empty_slot(struct NCR_700_Host_Parameters *hostdata)
{
	struct NCR_700_command_slot *slot = hostdata->free_list;

	if(slot == NULL) {
		/* sanity check */
		if(hostdata->command_slot_count != NCR_700_COMMAND_SLOTS_PER_HOST)
			printk(KERN_ERR "SLOTS FULL, but count is %d, should be %d\n", hostdata->command_slot_count, NCR_700_COMMAND_SLOTS_PER_HOST);
		return NULL;
	}

	if(slot->state != NCR_700_SLOT_FREE)
		/* should panic! */
		printk(KERN_ERR "BUSY SLOT ON FREE LIST!!!\n");
		

	hostdata->free_list = slot->ITL_forw;
	slot->ITL_forw = NULL;


	/* NOTE: set the state to busy here, not queued, since this
	 * indicates the slot is in use and cannot be run by the IRQ
	 * finish routine.  If we cannot queue the command when it
	 * is properly build, we then change to NCR_700_SLOT_QUEUED */
	slot->state = NCR_700_SLOT_BUSY;
	hostdata->command_slot_count++;
	
	return slot;
}

STATIC void 
free_slot(struct NCR_700_command_slot *slot,
	  struct NCR_700_Host_Parameters *hostdata)
{
	if((slot->state & NCR_700_SLOT_MASK) != NCR_700_SLOT_MAGIC) {
		printk(KERN_ERR "53c700: SLOT %p is not MAGIC!!!\n", slot);
	}
	if(slot->state == NCR_700_SLOT_FREE) {
		printk(KERN_ERR "53c700: SLOT %p is FREE!!!\n", slot);
	}
	
	slot->resume_offset = 0;
	slot->cmnd = NULL;
	slot->state = NCR_700_SLOT_FREE;
	slot->ITL_forw = hostdata->free_list;
	hostdata->free_list = slot;
	hostdata->command_slot_count--;
}


/* This routine really does very little.  The command is indexed on
   the ITL and (if tagged) the ITLQ lists in _queuecommand */
STATIC void
save_for_reselection(struct NCR_700_Host_Parameters *hostdata,
		     struct scsi_cmnd *SCp, __u32 dsp)
{
	/* Its just possible that this gets executed twice */
	if(SCp != NULL) {
		struct NCR_700_command_slot *slot =
			(struct NCR_700_command_slot *)SCp->host_scribble;

		slot->resume_offset = dsp;
	}
	hostdata->state = NCR_700_HOST_FREE;
	hostdata->cmd = NULL;
}

STATIC inline void
NCR_700_unmap(struct NCR_700_Host_Parameters *hostdata, struct scsi_cmnd *SCp,
	      struct NCR_700_command_slot *slot)
{
	if(SCp->sc_data_direction != DMA_NONE &&
	   SCp->sc_data_direction != DMA_BIDIRECTIONAL) {
		if(SCp->use_sg) {
			dma_unmap_sg(hostdata->dev, SCp->buffer,
				     SCp->use_sg, SCp->sc_data_direction);
		} else {
			dma_unmap_single(hostdata->dev, slot->dma_handle,
					 SCp->request_bufflen,
					 SCp->sc_data_direction);
		}
	}
}

STATIC inline void
NCR_700_scsi_done(struct NCR_700_Host_Parameters *hostdata,
	       struct scsi_cmnd *SCp, int result)
{
	hostdata->state = NCR_700_HOST_FREE;
	hostdata->cmd = NULL;

	if(SCp != NULL) {
		struct NCR_700_command_slot *slot = 
			(struct NCR_700_command_slot *)SCp->host_scribble;
		
		NCR_700_unmap(hostdata, SCp, slot);
		dma_unmap_single(hostdata->dev, slot->pCmd,
				 sizeof(SCp->cmnd), DMA_TO_DEVICE);
		if(SCp->cmnd[0] == REQUEST_SENSE && SCp->cmnd[6] == NCR_700_INTERNAL_SENSE_MAGIC) {
#ifdef NCR_700_DEBUG
			printk(" ORIGINAL CMD %p RETURNED %d, new return is %d sense is\n",
			       SCp, SCp->cmnd[7], result);
			scsi_print_sense("53c700", SCp);

#endif
			/* restore the old result if the request sense was
			 * successful */
			if(result == 0)
				result = SCp->cmnd[7];
			/* now restore the original command */
			memcpy((void *) SCp->cmnd, (void *) SCp->data_cmnd,
			       sizeof(SCp->data_cmnd));
			SCp->request_buffer = SCp->buffer;
			SCp->request_bufflen = SCp->bufflen;
			SCp->use_sg = SCp->old_use_sg;
			SCp->cmd_len = SCp->old_cmd_len;
			SCp->sc_data_direction = SCp->sc_old_data_direction;
			SCp->underflow = SCp->old_underflow;
			
		}
		free_slot(slot, hostdata);
#ifdef NCR_700_DEBUG
		if(NCR_700_get_depth(SCp->device) == 0 ||
		   NCR_700_get_depth(SCp->device) > SCp->device->queue_depth)
			printk(KERN_ERR "Invalid depth in NCR_700_scsi_done(): %d\n",
			       NCR_700_get_depth(SCp->device));
#endif /* NCR_700_DEBUG */
		NCR_700_set_depth(SCp->device, NCR_700_get_depth(SCp->device) - 1);

		SCp->host_scribble = NULL;
		SCp->result = result;
		SCp->scsi_done(SCp);
	} else {
		printk(KERN_ERR "53c700: SCSI DONE HAS NULL SCp\n");
	}
}


STATIC void
NCR_700_internal_bus_reset(struct Scsi_Host *host)
{
	/* Bus reset */
	NCR_700_writeb(ASSERT_RST, host, SCNTL1_REG);
	udelay(50);
	NCR_700_writeb(0, host, SCNTL1_REG);

}

STATIC void
NCR_700_chip_setup(struct Scsi_Host *host)
{
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)host->hostdata[0];
	__u32 dcntl_extra = 0;
	__u8 min_period;
	__u8 min_xferp = (hostdata->chip710 ? NCR_710_MIN_XFERP : NCR_700_MIN_XFERP);

	if(hostdata->chip710) {
		__u8 burst_disable = hostdata->burst_disable
			? BURST_DISABLE : 0;
		dcntl_extra = COMPAT_700_MODE;

		NCR_700_writeb(dcntl_extra, host, DCNTL_REG);
		NCR_700_writeb(BURST_LENGTH_8  | hostdata->dmode_extra,
			       host, DMODE_710_REG);
		NCR_700_writeb(burst_disable | (hostdata->differential ? 
						DIFF : 0), host, CTEST7_REG);
		NCR_700_writeb(BTB_TIMER_DISABLE, host, CTEST0_REG);
		NCR_700_writeb(FULL_ARBITRATION | ENABLE_PARITY | PARITY
			       | AUTO_ATN, host, SCNTL0_REG);
	} else {
		NCR_700_writeb(BURST_LENGTH_8 | hostdata->dmode_extra,
			       host, DMODE_700_REG);
		NCR_700_writeb(hostdata->differential ? 
			       DIFF : 0, host, CTEST7_REG);
		if(hostdata->fast) {
			/* this is for 700-66, does nothing on 700 */
			NCR_700_writeb(LAST_DIS_ENBL | ENABLE_ACTIVE_NEGATION 
				       | GENERATE_RECEIVE_PARITY, host,
				       CTEST8_REG);
		} else {
			NCR_700_writeb(FULL_ARBITRATION | ENABLE_PARITY
				       | PARITY | AUTO_ATN, host, SCNTL0_REG);
		}
	}

	NCR_700_writeb(1 << host->this_id, host, SCID_REG);
	NCR_700_writeb(0, host, SBCL_REG);
	NCR_700_writeb(ASYNC_OPERATION, host, SXFER_REG);

	NCR_700_writeb(PHASE_MM_INT | SEL_TIMEOUT_INT | GROSS_ERR_INT | UX_DISC_INT
	     | RST_INT | PAR_ERR_INT | SELECT_INT, host, SIEN_REG);

	NCR_700_writeb(ABORT_INT | INT_INST_INT | ILGL_INST_INT, host, DIEN_REG);
	NCR_700_writeb(ENABLE_SELECT, host, SCNTL1_REG);
	if(hostdata->clock > 75) {
		printk(KERN_ERR "53c700: Clock speed %dMHz is too high: 75Mhz is the maximum this chip can be driven at\n", hostdata->clock);
		/* do the best we can, but the async clock will be out
		 * of spec: sync divider 2, async divider 3 */
		DEBUG(("53c700: sync 2 async 3\n"));
		NCR_700_writeb(SYNC_DIV_2_0, host, SBCL_REG);
		NCR_700_writeb(ASYNC_DIV_3_0 | dcntl_extra, host, DCNTL_REG);
		hostdata->sync_clock = hostdata->clock/2;
	} else	if(hostdata->clock > 50  && hostdata->clock <= 75) {
		/* sync divider 1.5, async divider 3 */
		DEBUG(("53c700: sync 1.5 async 3\n"));
		NCR_700_writeb(SYNC_DIV_1_5, host, SBCL_REG);
		NCR_700_writeb(ASYNC_DIV_3_0 | dcntl_extra, host, DCNTL_REG);
		hostdata->sync_clock = hostdata->clock*2;
		hostdata->sync_clock /= 3;
		
	} else if(hostdata->clock > 37 && hostdata->clock <= 50) {
		/* sync divider 1, async divider 2 */
		DEBUG(("53c700: sync 1 async 2\n"));
		NCR_700_writeb(SYNC_DIV_1_0, host, SBCL_REG);
		NCR_700_writeb(ASYNC_DIV_2_0 | dcntl_extra, host, DCNTL_REG);
		hostdata->sync_clock = hostdata->clock;
	} else if(hostdata->clock > 25 && hostdata->clock <=37) {
		/* sync divider 1, async divider 1.5 */
		DEBUG(("53c700: sync 1 async 1.5\n"));
		NCR_700_writeb(SYNC_DIV_1_0, host, SBCL_REG);
		NCR_700_writeb(ASYNC_DIV_1_5 | dcntl_extra, host, DCNTL_REG);
		hostdata->sync_clock = hostdata->clock;
	} else {
		DEBUG(("53c700: sync 1 async 1\n"));
		NCR_700_writeb(SYNC_DIV_1_0, host, SBCL_REG);
		NCR_700_writeb(ASYNC_DIV_1_0 | dcntl_extra, host, DCNTL_REG);
		/* sync divider 1, async divider 1 */
		hostdata->sync_clock = hostdata->clock;
	}
	/* Calculate the actual minimum period that can be supported
	 * by our synchronous clock speed.  See the 710 manual for
	 * exact details of this calculation which is based on a
	 * setting of the SXFER register */
	min_period = 1000*(4+min_xferp)/(4*hostdata->sync_clock);
	hostdata->min_period = NCR_700_MIN_PERIOD;
	if(min_period > NCR_700_MIN_PERIOD)
		hostdata->min_period = min_period;
}

STATIC void
NCR_700_chip_reset(struct Scsi_Host *host)
{
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)host->hostdata[0];
	if(hostdata->chip710) {
		NCR_700_writeb(SOFTWARE_RESET_710, host, ISTAT_REG);
		udelay(100);

		NCR_700_writeb(0, host, ISTAT_REG);
	} else {
		NCR_700_writeb(SOFTWARE_RESET, host, DCNTL_REG);
		udelay(100);
		
		NCR_700_writeb(0, host, DCNTL_REG);
	}

	mdelay(1000);

	NCR_700_chip_setup(host);
}

/* The heart of the message processing engine is that the instruction
 * immediately after the INT is the normal case (and so must be CLEAR
 * ACK).  If we want to do something else, we call that routine in
 * scripts and set temp to be the normal case + 8 (skipping the CLEAR
 * ACK) so that the routine returns correctly to resume its activity
 * */
STATIC __u32
process_extended_message(struct Scsi_Host *host, 
			 struct NCR_700_Host_Parameters *hostdata,
			 struct scsi_cmnd *SCp, __u32 dsp, __u32 dsps)
{
	__u32 resume_offset = dsp, temp = dsp + 8;
	__u8 pun = 0xff, lun = 0xff;

	if(SCp != NULL) {
		pun = SCp->device->id;
		lun = SCp->device->lun;
	}

	switch(hostdata->msgin[2]) {
	case A_SDTR_MSG:
		if(SCp != NULL && NCR_700_is_flag_set(SCp->device, NCR_700_DEV_BEGIN_SYNC_NEGOTIATION)) {
			struct scsi_target *starget = SCp->device->sdev_target;
			__u8 period = hostdata->msgin[3];
			__u8 offset = hostdata->msgin[4];

			if(offset == 0 || period == 0) {
				offset = 0;
				period = 0;
			}

			spi_offset(starget) = offset;
			spi_period(starget) = period;
			
			if(NCR_700_is_flag_set(SCp->device, NCR_700_DEV_PRINT_SYNC_NEGOTIATION)) {
				spi_display_xfer_agreement(starget);
				NCR_700_clear_flag(SCp->device, NCR_700_DEV_PRINT_SYNC_NEGOTIATION);
			}
			
			NCR_700_set_flag(SCp->device, NCR_700_DEV_NEGOTIATED_SYNC);
			NCR_700_clear_flag(SCp->device, NCR_700_DEV_BEGIN_SYNC_NEGOTIATION);
			
			NCR_700_writeb(NCR_700_get_SXFER(SCp->device),
				       host, SXFER_REG);

		} else {
			/* SDTR message out of the blue, reject it */
			shost_printk(KERN_WARNING, host,
				"Unexpected SDTR msg\n");
			hostdata->msgout[0] = A_REJECT_MSG;
			dma_cache_sync(hostdata->msgout, 1, DMA_TO_DEVICE);
			script_patch_16(hostdata->script, MessageCount, 1);
			/* SendMsgOut returns, so set up the return
			 * address */
			resume_offset = hostdata->pScript + Ent_SendMessageWithATN;
		}
		break;
	
	case A_WDTR_MSG:
		printk(KERN_INFO "scsi%d: (%d:%d), Unsolicited WDTR after CMD, Rejecting\n",
		       host->host_no, pun, lun);
		hostdata->msgout[0] = A_REJECT_MSG;
		dma_cache_sync(hostdata->msgout, 1, DMA_TO_DEVICE);
		script_patch_16(hostdata->script, MessageCount, 1);
		resume_offset = hostdata->pScript + Ent_SendMessageWithATN;

		break;

	default:
		printk(KERN_INFO "scsi%d (%d:%d): Unexpected message %s: ",
		       host->host_no, pun, lun,
		       NCR_700_phase[(dsps & 0xf00) >> 8]);
		spi_print_msg(hostdata->msgin);
		printk("\n");
		/* just reject it */
		hostdata->msgout[0] = A_REJECT_MSG;
		dma_cache_sync(hostdata->msgout, 1, DMA_TO_DEVICE);
		script_patch_16(hostdata->script, MessageCount, 1);
		/* SendMsgOut returns, so set up the return
		 * address */
		resume_offset = hostdata->pScript + Ent_SendMessageWithATN;
	}
	NCR_700_writel(temp, host, TEMP_REG);
	return resume_offset;
}

STATIC __u32
process_message(struct Scsi_Host *host,	struct NCR_700_Host_Parameters *hostdata,
		struct scsi_cmnd *SCp, __u32 dsp, __u32 dsps)
{
	/* work out where to return to */
	__u32 temp = dsp + 8, resume_offset = dsp;
	__u8 pun = 0xff, lun = 0xff;

	if(SCp != NULL) {
		pun = SCp->device->id;
		lun = SCp->device->lun;
	}

#ifdef NCR_700_DEBUG
	printk("scsi%d (%d:%d): message %s: ", host->host_no, pun, lun,
	       NCR_700_phase[(dsps & 0xf00) >> 8]);
	spi_print_msg(hostdata->msgin);
	printk("\n");
#endif

	switch(hostdata->msgin[0]) {

	case A_EXTENDED_MSG:
		resume_offset =  process_extended_message(host, hostdata, SCp,
							  dsp, dsps);
		break;

	case A_REJECT_MSG:
		if(SCp != NULL && NCR_700_is_flag_set(SCp->device, NCR_700_DEV_BEGIN_SYNC_NEGOTIATION)) {
			/* Rejected our sync negotiation attempt */
			spi_period(SCp->device->sdev_target) =
				spi_offset(SCp->device->sdev_target) = 0;
			NCR_700_set_flag(SCp->device, NCR_700_DEV_NEGOTIATED_SYNC);
			NCR_700_clear_flag(SCp->device, NCR_700_DEV_BEGIN_SYNC_NEGOTIATION);
		} else if(SCp != NULL && NCR_700_get_tag_neg_state(SCp->device) == NCR_700_DURING_TAG_NEGOTIATION) {
			/* rejected our first simple tag message */
			scmd_printk(KERN_WARNING, SCp,
				"Rejected first tag queue attempt, turning off tag queueing\n");
			/* we're done negotiating */
			NCR_700_set_tag_neg_state(SCp->device, NCR_700_FINISHED_TAG_NEGOTIATION);
			hostdata->tag_negotiated &= ~(1<<scmd_id(SCp));
			SCp->device->tagged_supported = 0;
			scsi_deactivate_tcq(SCp->device, host->cmd_per_lun);
		} else {
			shost_printk(KERN_WARNING, host,
				"(%d:%d) Unexpected REJECT Message %s\n",
			       pun, lun,
			       NCR_700_phase[(dsps & 0xf00) >> 8]);
			/* however, just ignore it */
		}
		break;

	case A_PARITY_ERROR_MSG:
		printk(KERN_ERR "scsi%d (%d:%d) Parity Error!\n", host->host_no,
		       pun, lun);
		NCR_700_internal_bus_reset(host);
		break;
	case A_SIMPLE_TAG_MSG:
		printk(KERN_INFO "scsi%d (%d:%d) SIMPLE TAG %d %s\n", host->host_no,
		       pun, lun, hostdata->msgin[1],
		       NCR_700_phase[(dsps & 0xf00) >> 8]);
		/* just ignore it */
		break;
	default:
		printk(KERN_INFO "scsi%d (%d:%d): Unexpected message %s: ",
		       host->host_no, pun, lun,
		       NCR_700_phase[(dsps & 0xf00) >> 8]);

		spi_print_msg(hostdata->msgin);
		printk("\n");
		/* just reject it */
		hostdata->msgout[0] = A_REJECT_MSG;
		dma_cache_sync(hostdata->msgout, 1, DMA_TO_DEVICE);
		script_patch_16(hostdata->script, MessageCount, 1);
		/* SendMsgOut returns, so set up the return
		 * address */
		resume_offset = hostdata->pScript + Ent_SendMessageWithATN;

		break;
	}
	NCR_700_writel(temp, host, TEMP_REG);
	/* set us up to receive another message */
	dma_cache_sync(hostdata->msgin, MSG_ARRAY_SIZE, DMA_FROM_DEVICE);
	return resume_offset;
}

STATIC __u32
process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp,
			 struct Scsi_Host *host,
			 struct NCR_700_Host_Parameters *hostdata)
{
	__u32 resume_offset = 0;
	__u8 pun = 0xff, lun=0xff;

	if(SCp != NULL) {
		pun = SCp->device->id;
		lun = SCp->device->lun;
	}

	if(dsps == A_GOOD_STATUS_AFTER_STATUS) {
		DEBUG(("  COMMAND COMPLETE, status=%02x\n",
		       hostdata->status[0]));
		/* OK, if TCQ still under negotiation, we now know it works */
		if (NCR_700_get_tag_neg_state(SCp->device) == NCR_700_DURING_TAG_NEGOTIATION)
			NCR_700_set_tag_neg_state(SCp->device,
						  NCR_700_FINISHED_TAG_NEGOTIATION);
			
		/* check for contingent allegiance contitions */
		if(status_byte(hostdata->status[0]) == CHECK_CONDITION ||
		   status_byte(hostdata->status[0]) == COMMAND_TERMINATED) {
			struct NCR_700_command_slot *slot =
				(struct NCR_700_command_slot *)SCp->host_scribble;
			if(SCp->cmnd[0] == REQUEST_SENSE) {
				/* OOPS: bad device, returning another
				 * contingent allegiance condition */
				scmd_printk(KERN_ERR, SCp,
					"broken device is looping in contingent allegiance: ignoring\n");
				NCR_700_scsi_done(hostdata, SCp, hostdata->status[0]);
			} else {
#ifdef NCR_DEBUG
				scsi_print_command(SCp);
				printk("  cmd %p has status %d, requesting sense\n",
				       SCp, hostdata->status[0]);
#endif
				/* we can destroy the command here
				 * because the contingent allegiance
				 * condition will cause a retry which
				 * will re-copy the command from the
				 * saved data_cmnd.  We also unmap any
				 * data associated with the command
				 * here */
				NCR_700_unmap(hostdata, SCp, slot);

				SCp->cmnd[0] = REQUEST_SENSE;
				SCp->cmnd[1] = (SCp->device->lun & 0x7) << 5;
				SCp->cmnd[2] = 0;
				SCp->cmnd[3] = 0;
				SCp->cmnd[4] = sizeof(SCp->sense_buffer);
				SCp->cmnd[5] = 0;
				SCp->cmd_len = 6;
				/* Here's a quiet hack: the
				 * REQUEST_SENSE command is six bytes,
				 * so store a flag indicating that
				 * this was an internal sense request
				 * and the original status at the end
				 * of the command */
				SCp->cmnd[6] = NCR_700_INTERNAL_SENSE_MAGIC;
				SCp->cmnd[7] = hostdata->status[0];
				SCp->use_sg = 0;
				SCp->sc_data_direction = DMA_FROM_DEVICE;
				dma_sync_single_for_device(hostdata->dev, slot->pCmd,
							   SCp->cmd_len, DMA_TO_DEVICE);
				SCp->request_bufflen = sizeof(SCp->sense_buffer);
				slot->dma_handle = dma_map_single(hostdata->dev, SCp->sense_buffer, sizeof(SCp->sense_buffer), DMA_FROM_DEVICE);
				slot->SG[0].ins = bS_to_host(SCRIPT_MOVE_DATA_IN | sizeof(SCp->sense_buffer));
				slot->SG[0].pAddr = bS_to_host(slot->dma_handle);
				slot->SG[1].ins = bS_to_host(SCRIPT_RETURN);
				slot->SG[1].pAddr = 0;
				slot->resume_offset = hostdata->pScript;
				dma_cache_sync(slot->SG, sizeof(slot->SG[0])*2, DMA_TO_DEVICE);
				dma_cache_sync(SCp->sense_buffer, sizeof(SCp->sense_buffer), DMA_FROM_DEVICE);
				
				/* queue the command for reissue */
				slot->state = NCR_700_SLOT_QUEUED;
				hostdata->state = NCR_700_HOST_FREE;
				hostdata->cmd = NULL;
			}
		} else {
			// Currently rely on the mid layer evaluation
			// of the tag queuing capability
			//
			//if(status_byte(hostdata->status[0]) == GOOD &&
			//   SCp->cmnd[0] == INQUIRY && SCp->use_sg == 0) {
			//	/* Piggy back the tag queueing support
			//	 * on this command */
			//	dma_sync_single_for_cpu(hostdata->dev,
			//			    slot->dma_handle,
			//			    SCp->request_bufflen,
			//			    DMA_FROM_DEVICE);
			//	if(((char *)SCp->request_buffer)[7] & 0x02) {
			//		scmd_printk(KERN_INFO, SCp,
			//		     "Enabling Tag Command Queuing\n");
			//		hostdata->tag_negotiated |= (1<<scmd_id(SCp));
			//		NCR_700_set_flag(SCp->device, NCR_700_DEV_BEGIN_TAG_QUEUEING);
			//	} else {
			//		NCR_700_clear_flag(SCp->device, NCR_700_DEV_BEGIN_TAG_QUEUEING);
			//		hostdata->tag_negotiated &= ~(1<<scmd_id(SCp));
			//	}
			//}
			NCR_700_scsi_done(hostdata, SCp, hostdata->status[0]);
		}
	} else if((dsps & 0xfffff0f0) == A_UNEXPECTED_PHASE) {
		__u8 i = (dsps & 0xf00) >> 8;

		scmd_printk(KERN_ERR, SCp, "UNEXPECTED PHASE %s (%s)\n",
		       NCR_700_phase[i],
		       sbcl_to_string(NCR_700_readb(host, SBCL_REG)));
		scmd_printk(KERN_ERR, SCp, "         len = %d, cmd =",
			SCp->cmd_len);
		scsi_print_command(SCp);

		NCR_700_internal_bus_reset(host);
	} else if((dsps & 0xfffff000) == A_FATAL) {
		int i = (dsps & 0xfff);

		printk(KERN_ERR "scsi%d: (%d:%d) FATAL ERROR: %s\n",
		       host->host_no, pun, lun, NCR_700_fatal_messages[i]);
		if(dsps == A_FATAL_ILLEGAL_MSG_LENGTH) {
			printk(KERN_ERR "     msg begins %02x %02x\n",
			       hostdata->msgin[0], hostdata->msgin[1]);
		}
		NCR_700_internal_bus_reset(host);
	} else if((dsps & 0xfffff0f0) == A_DISCONNECT) {
#ifdef NCR_700_DEBUG
		__u8 i = (dsps & 0xf00) >> 8;

		printk("scsi%d: (%d:%d), DISCONNECTED (%d) %s\n",
		       host->host_no, pun, lun,
		       i, NCR_700_phase[i]);
#endif
		save_for_reselection(hostdata, SCp, dsp);

	} else if(dsps == A_RESELECTION_IDENTIFIED) {
		__u8 lun;
		struct NCR_700_command_slot *slot;
		__u8 reselection_id = hostdata->reselection_id;
		struct scsi_device *SDp;

		lun = hostdata->msgin[0] & 0x1f;

		hostdata->reselection_id = 0xff;
		DEBUG(("scsi%d: (%d:%d) RESELECTED!\n",
		       host->host_no, reselection_id, lun));
		/* clear the reselection indicator */
		SDp = __scsi_device_lookup(host, 0, reselection_id, lun);
		if(unlikely(SDp == NULL)) {
			printk(KERN_ERR "scsi%d: (%d:%d) HAS NO device\n",
			       host->host_no, reselection_id, lun);
			BUG();
		}
		if(hostdata->msgin[1] == A_SIMPLE_TAG_MSG) {
			struct scsi_cmnd *SCp = scsi_find_tag(SDp, hostdata->msgin[2]);
			if(unlikely(SCp == NULL)) {
				printk(KERN_ERR "scsi%d: (%d:%d) no saved request for tag %d\n", 
				       host->host_no, reselection_id, lun, hostdata->msgin[2]);
				BUG();
			}

			slot = (struct NCR_700_command_slot *)SCp->host_scribble;
			DDEBUG(KERN_DEBUG, SDp,
				"reselection is tag %d, slot %p(%d)\n",
				hostdata->msgin[2], slot, slot->tag);
		} else {
			struct scsi_cmnd *SCp = scsi_find_tag(SDp, SCSI_NO_TAG);
			if(unlikely(SCp == NULL)) {
				sdev_printk(KERN_ERR, SDp,
					"no saved request for untagged cmd\n");
				BUG();
			}
			slot = (struct NCR_700_command_slot *)SCp->host_scribble;
		}

		if(slot == NULL) {
			printk(KERN_ERR "scsi%d: (%d:%d) RESELECTED but no saved command (MSG = %02x %02x %02x)!!\n",
			       host->host_no, reselection_id, lun,
			       hostdata->msgin[0], hostdata->msgin[1],
			       hostdata->msgin[2]);
		} else {
			if(hostdata->state != NCR_700_HOST_BUSY)
				printk(KERN_ERR "scsi%d: FATAL, host not busy during valid reselection!\n",
				       host->host_no);
			resume_offset = slot->resume_offset;
			hostdata->cmd = slot->cmnd;

			/* re-patch for this command */
			script_patch_32_abs(hostdata->script, CommandAddress, 
					    slot->pCmd);
			script_patch_16(hostdata->script,
					CommandCount, slot->cmnd->cmd_len);
			script_patch_32_abs(hostdata->script, SGScriptStartAddress,
					    to32bit(&slot->pSG[0].ins));

			/* Note: setting SXFER only works if we're
			 * still in the MESSAGE phase, so it is vital
			 * that ACK is still asserted when we process
			 * the reselection message.  The resume offset
			 * should therefore always clear ACK */
			NCR_700_writeb(NCR_700_get_SXFER(hostdata->cmd->device),
				       host, SXFER_REG);
			dma_cache_sync(hostdata->msgin,
				       MSG_ARRAY_SIZE, DMA_FROM_DEVICE);
			dma_cache_sync(hostdata->msgout,
				       MSG_ARRAY_SIZE, DMA_TO_DEVICE);
			/* I'm just being paranoid here, the command should
			 * already have been flushed from the cache */
			dma_cache_sync(slot->cmnd->cmnd,
				       slot->cmnd->cmd_len, DMA_TO_DEVICE);


			
		}
	} else if(dsps == A_RESELECTED_DURING_SELECTION) {

		/* This section is full of debugging code because I've
		 * never managed to reach it.  I think what happens is
		 * that, because the 700 runs with selection
		 * interrupts enabled the whole time that we take a
		 * selection interrupt before we manage to get to the
		 * reselected script interrupt */

		__u8 reselection_id = NCR_700_readb(host, SFBR_REG);
		struct NCR_700_command_slot *slot;
		
		/* Take out our own ID */
		reselection_id &= ~(1<<host->this_id);
		
		/* I've never seen this happen, so keep this as a printk rather
		 * than a debug */
		printk(KERN_INFO "scsi%d: (%d:%d) RESELECTION DURING SELECTION, dsp=%08x[%04x] state=%d, count=%d\n",
		       host->host_no, reselection_id, lun, dsp, dsp - hostdata->pScript, hostdata->state, hostdata->command_slot_count);

		{
			/* FIXME: DEBUGGING CODE */
			__u32 SG = (__u32)bS_to_cpu(hostdata->script[A_SGScriptStartAddress_used[0]]);
			int i;

			for(i=0; i< NCR_700_COMMAND_SLOTS_PER_HOST; i++) {
				if(SG >= to32bit(&hostdata->slots[i].pSG[0])
				   && SG <= to32bit(&hostdata->slots[i].pSG[NCR_700_SG_SEGMENTS]))
					break;
			}
			printk(KERN_INFO "IDENTIFIED SG segment as being %08x in slot %p, cmd %p, slot->resume_offset=%08x\n", SG, &hostdata->slots[i], hostdata->slots[i].cmnd, hostdata->slots[i].resume_offset);
			SCp =  hostdata->slots[i].cmnd;
		}

		if(SCp != NULL) {
			slot = (struct NCR_700_command_slot *)SCp->host_scribble;
			/* change slot from busy to queued to redo command */
			slot->state = NCR_700_SLOT_QUEUED;
		}
		hostdata->cmd = NULL;
		
		if(reselection_id == 0) {
			if(hostdata->reselection_id == 0xff) {
				printk(KERN_ERR "scsi%d: Invalid reselection during selection!!\n", host->host_no);
				return 0;
			} else {
				printk(KERN_ERR "scsi%d: script reselected and we took a selection interrupt\n",
				       host->host_no);
				reselection_id = hostdata->reselection_id;
			}
		} else {
			
			/* convert to real ID */
			reselection_id = bitmap_to_number(reselection_id);
		}
		hostdata->reselection_id = reselection_id;
		/* just in case we have a stale simple tag message, clear it */
		hostdata->msgin[1] = 0;
		dma_cache_sync(hostdata->msgin,
			       MSG_ARRAY_SIZE, DMA_BIDIRECTIONAL);
		if(hostdata->tag_negotiated & (1<<reselection_id)) {
			resume_offset = hostdata->pScript + Ent_GetReselectionWithTag;
		} else {
			resume_offset = hostdata->pScript + Ent_GetReselectionData;
		}
	} else if(dsps == A_COMPLETED_SELECTION_AS_TARGET) {
		/* we've just disconnected from the bus, do nothing since
		 * a return here will re-run the queued command slot
		 * that may have been interrupted by the initial selection */
		DEBUG((" SELECTION COMPLETED\n"));
	} else if((dsps & 0xfffff0f0) == A_MSG_IN) { 
		resume_offset = process_message(host, hostdata, SCp,
						dsp, dsps);
	} else if((dsps &  0xfffff000) == 0) {
		__u8 i = (dsps & 0xf0) >> 4, j = (dsps & 0xf00) >> 8;
		printk(KERN_ERR "scsi%d: (%d:%d), unhandled script condition %s %s at %04x\n",
		       host->host_no, pun, lun, NCR_700_condition[i],
		       NCR_700_phase[j], dsp - hostdata->pScript);
		if(SCp != NULL) {
			scsi_print_command(SCp);

			if(SCp->use_sg) {
				for(i = 0; i < SCp->use_sg + 1; i++) {
					printk(KERN_INFO " SG[%d].length = %d, move_insn=%08x, addr %08x\n", i, ((struct scatterlist *)SCp->buffer)[i].length, ((struct NCR_700_command_slot *)SCp->host_scribble)->SG[i].ins, ((struct NCR_700_command_slot *)SCp->host_scribble)->SG[i].pAddr);
				}
			}
		}	       
		NCR_700_internal_bus_reset(host);
	} else if((dsps & 0xfffff000) == A_DEBUG_INTERRUPT) {
		printk(KERN_NOTICE "scsi%d (%d:%d) DEBUG INTERRUPT %d AT %08x[%04x], continuing\n",
		       host->host_no, pun, lun, dsps & 0xfff, dsp, dsp - hostdata->pScript);
		resume_offset = dsp;
	} else {
		printk(KERN_ERR "scsi%d: (%d:%d), unidentified script interrupt 0x%x at %04x\n",
		       host->host_no, pun, lun, dsps, dsp - hostdata->pScript);
		NCR_700_internal_bus_reset(host);
	}
	return resume_offset;
}

/* We run the 53c700 with selection interrupts always enabled.  This
 * means that the chip may be selected as soon as the bus frees.  On a
 * busy bus, this can be before the scripts engine finishes its
 * processing.  Therefore, part of the selection processing has to be
 * to find out what the scripts engine is doing and complete the
 * function if necessary (i.e. process the pending disconnect or save
 * the interrupted initial selection */
STATIC inline __u32
process_selection(struct Scsi_Host *host, __u32 dsp)
{
	__u8 id = 0;	/* Squash compiler warning */
	int count = 0;
	__u32 resume_offset = 0;
	struct NCR_700_Host_Parameters *hostdata =
		(struct NCR_700_Host_Parameters *)host->hostdata[0];
	struct scsi_cmnd *SCp = hostdata->cmd;
	__u8 sbcl;

	for(count = 0; count < 5; count++) {
		id = NCR_700_readb(host, hostdata->chip710 ?
				   CTEST9_REG : SFBR_REG);

		/* Take out our own ID */
		id &= ~(1<<host->this_id);
		if(id != 0) 
			break;
		udelay(5);
	}
	sbcl = NCR_700_readb(host, SBCL_REG);
	if((sbcl & SBCL_IO) == 0) {
		/* mark as having been selected rather than reselected */
		id = 0xff;
	} else {
		/* convert to real ID */
		hostdata->reselection_id = id = bitmap_to_number(id);
		DEBUG(("scsi%d:  Reselected by %d\n",
		       host->host_no, id));
	}
	if(hostdata->state == NCR_700_HOST_BUSY && SCp != NULL) {
		struct NCR_700_command_slot *slot =
			(struct NCR_700_command_slot *)SCp->host_scribble;
		DEBUG(("  ID %d WARNING: RESELECTION OF BUSY HOST, saving cmd %p, slot %p, addr %x [%04x], resume %x!\n", id, hostdata->cmd, slot, dsp, dsp - hostdata->pScript, resume_offset));
		
		switch(dsp - hostdata->pScript) {
		case Ent_Disconnect1:
		case Ent_Disconnect2:
			save_for_reselection(hostdata, SCp, Ent_Disconnect2 + hostdata->pScript);
			break;
		case Ent_Disconnect3:
		case Ent_Disconnect4:
			save_for_reselection(hostdata, SCp, Ent_Disconnect4 + hostdata->pScript);
			break;
		case Ent_Disconnect5:
		case Ent_Disconnect6:
			save_for_reselection(hostdata, SCp, Ent_Disconnect6 + hostdata->pScript);
			break;
		case Ent_Disconnect7:
		case Ent_Disconnect8:
			save_for_reselection(hostdata, SCp, Ent_Disconnect8 + hostdata->pScript);
			break;
		case Ent_Finish1:
		case Ent_Finish2:
			process_script_interrupt(A_GOOD_STATUS_AFTER_STATUS, dsp, SCp, host, hostdata);
			break;
			
		default:
			slot->state = NCR_700_SLOT_QUEUED;
			break;
			}
	}
	hostdata->state = NCR_700_HOST_BUSY;
	hostdata->cmd = NULL;
	/* clear any stale simple tag message */
	hostdata->msgin[1] = 0;
	dma_cache_sync(hostdata->msgin, MSG_ARRAY_SIZE,
		       DMA_BIDIRECTIONAL);

	if(id == 0xff) {
		/* Selected as target, Ignore */
		resume_offset = hostdata->pScript + Ent_SelectedAsTarget;
	} else if(hostdata->tag_negotiated & (1<<id)) {
		resume_offset = hostdata->pScript + Ent_GetReselectionWithTag;
	} else {
		resume_offset = hostdata->pScript + Ent_GetReselectionData;
	}
	return resume_offset;
}

static inline void
NCR_700_clear_fifo(struct Scsi_Host *host) {
	const struct NCR_700_Host_Parameters *hostdata
		= (struct NCR_700_Host_Parameters *)host->hostdata[0];
	if(hostdata->chip710) {
		NCR_700_writeb(CLR_FIFO_710, host, CTEST8_REG);
	} else {
		NCR_700_writeb(CLR_FIFO, host, DFIFO_REG);
	}
}

static inline void
NCR_700_flush_fifo(struct Scsi_Host *host) {
	const struct NCR_700_Host_Parameters *hostdata
		= (struct NCR_700_Host_Parameters *)host->hostdata[0];
	if(hostdata->chip710) {
		NCR_700_writeb(FLUSH_DMA_FIFO_710, host, CTEST8_REG);
		udelay(10);
		NCR_700_writeb(0, host, CTEST8_REG);
	} else {
		NCR_700_writeb(FLUSH_DMA_FIFO, host, DFIFO_REG);
		udelay(10);
		NCR_700_writeb(0, host, DFIFO_REG);
	}
}


/* The queue lock with interrupts disabled must be held on entry to
 * this function */
STATIC int
NCR_700_start_command(struct scsi_cmnd *SCp)
{
	struct NCR_700_command_slot *slot =
		(struct NCR_700_command_slot *)SCp->host_scribble;
	struct NCR_700_Host_Parameters *hostdata =
		(struct NCR_700_Host_Parameters *)SCp->device->host->hostdata[0];
	__u16 count = 1;	/* for IDENTIFY message */
	
	if(hostdata->state != NCR_700_HOST_FREE) {
		/* keep this inside the lock to close the race window where
		 * the running command finishes on another CPU while we don't
		 * change the state to queued on this one */
		slot->state = NCR_700_SLOT_QUEUED;

		DEBUG(("scsi%d: host busy, queueing command %p, slot %p\n",
		       SCp->device->host->host_no, slot->cmnd, slot));
		return 0;
	}
	hostdata->state = NCR_700_HOST_BUSY;
	hostdata->cmd = SCp;
	slot->state = NCR_700_SLOT_BUSY;
	/* keep interrupts disabled until we have the command correctly
	 * set up so we cannot take a selection interrupt */

	hostdata->msgout[0] = NCR_700_identify(SCp->cmnd[0] != REQUEST_SENSE,
					       SCp->device->lun);
	/* for INQUIRY or REQUEST_SENSE commands, we cannot be sure
	 * if the negotiated transfer parameters still hold, so
	 * always renegotiate them */
	if(SCp->cmnd[0] == INQUIRY || SCp->cmnd[0] == REQUEST_SENSE) {
		NCR_700_clear_flag(SCp->device, NCR_700_DEV_NEGOTIATED_SYNC);
	}

	/* REQUEST_SENSE is asking for contingent I_T_L(_Q) status.
	 * If a contingent allegiance condition exists, the device
	 * will refuse all tags, so send the request sense as untagged
	 * */
	if((hostdata->tag_negotiated & (1<<scmd_id(SCp)))
	   && (slot->tag != SCSI_NO_TAG && SCp->cmnd[0] != REQUEST_SENSE)) {
		count += scsi_populate_tag_msg(SCp, &hostdata->msgout[count]);
	}

	if(hostdata->fast &&
	   NCR_700_is_flag_clear(SCp->device, NCR_700_DEV_NEGOTIATED_SYNC)) {
		count += spi_populate_sync_msg(&hostdata->msgout[count],
				spi_period(SCp->device->sdev_target),
				spi_offset(SCp->device->sdev_target));
		NCR_700_set_flag(SCp->device, NCR_700_DEV_BEGIN_SYNC_NEGOTIATION);
	}

	script_patch_16(hostdata->script, MessageCount, count);


	script_patch_ID(hostdata->script,
			Device_ID, 1<<scmd_id(SCp));

	script_patch_32_abs(hostdata->script, CommandAddress, 
			    slot->pCmd);
	script_patch_16(hostdata->script, CommandCount, SCp->cmd_len);
	/* finally plumb the beginning of the SG list into the script
	 * */
	script_patch_32_abs(hostdata->script, SGScriptStartAddress,
			    to32bit(&slot->pSG[0].ins));
	NCR_700_clear_fifo(SCp->device->host);

	if(slot->resume_offset == 0)
		slot->resume_offset = hostdata->pScript;
	/* now perform all the writebacks and invalidates */
	dma_cache_sync(hostdata->msgout, count, DMA_TO_DEVICE);
	dma_cache_sync(hostdata->msgin, MSG_ARRAY_SIZE,
		       DMA_FROM_DEVICE);
	dma_cache_sync(SCp->cmnd, SCp->cmd_len, DMA_TO_DEVICE);
	dma_cache_sync(hostdata->status, 1, DMA_FROM_DEVICE);

	/* set the synchronous period/offset */
	NCR_700_writeb(NCR_700_get_SXFER(SCp->device),
		       SCp->device->host, SXFER_REG);
	NCR_700_writel(slot->temp, SCp->device->host, TEMP_REG);
	NCR_700_writel(slot->resume_offset, SCp->device->host, DSP_REG);

	return 1;
}

irqreturn_t
NCR_700_intr(int irq, void *dev_id, struct pt_regs *regs)
{
	struct Scsi_Host *host = (struct Scsi_Host *)dev_id;
	struct NCR_700_Host_Parameters *hostdata =
		(struct NCR_700_Host_Parameters *)host->hostdata[0];
	__u8 istat;
	__u32 resume_offset = 0;
	__u8 pun = 0xff, lun = 0xff;
	unsigned long flags;
	int handled = 0;

	/* Use the host lock to serialise acess to the 53c700
	 * hardware.  Note: In future, we may need to take the queue
	 * lock to enter the done routines.  When that happens, we
	 * need to ensure that for this driver, the host lock and the
	 * queue lock point to the same thing. */
	spin_lock_irqsave(host->host_lock, flags);
	if((istat = NCR_700_readb(host, ISTAT_REG))
	      & (SCSI_INT_PENDING | DMA_INT_PENDING)) {
		__u32 dsps;
		__u8 sstat0 = 0, dstat = 0;
		__u32 dsp;
		struct scsi_cmnd *SCp = hostdata->cmd;
		enum NCR_700_Host_State state;

		handled = 1;
		state = hostdata->state;
		SCp = hostdata->cmd;

		if(istat & SCSI_INT_PENDING) {
			udelay(10);

			sstat0 = NCR_700_readb(host, SSTAT0_REG);
		}

		if(istat & DMA_INT_PENDING) {
			udelay(10);

			dstat = NCR_700_readb(host, DSTAT_REG);
		}

		dsps = NCR_700_readl(host, DSPS_REG);
		dsp = NCR_700_readl(host, DSP_REG);

		DEBUG(("scsi%d: istat %02x sstat0 %02x dstat %02x dsp %04x[%08x] dsps 0x%x\n",
		       host->host_no, istat, sstat0, dstat,
		       (dsp - (__u32)(hostdata->pScript))/4,
		       dsp, dsps));

		if(SCp != NULL) {
			pun = SCp->device->id;
			lun = SCp->device->lun;
		}

		if(sstat0 & SCSI_RESET_DETECTED) {
			struct scsi_device *SDp;
			int i;

			hostdata->state = NCR_700_HOST_BUSY;

			printk(KERN_ERR "scsi%d: Bus Reset detected, executing command %p, slot %p, dsp %08x[%04x]\n",
			       host->host_no, SCp, SCp == NULL ? NULL : SCp->host_scribble, dsp, dsp - hostdata->pScript);

			scsi_report_bus_reset(host, 0);

			/* clear all the negotiated parameters */
			__shost_for_each_device(SDp, host)
				SDp->hostdata = NULL;
			
			/* clear all the slots and their pending commands */
			for(i = 0; i < NCR_700_COMMAND_SLOTS_PER_HOST; i++) {
				struct scsi_cmnd *SCp;
				struct NCR_700_command_slot *slot =
					&hostdata->slots[i];

				if(slot->state == NCR_700_SLOT_FREE)
					continue;
				
				SCp = slot->cmnd;
				printk(KERN_ERR " failing command because of reset, slot %p, cmnd %p\n",
				       slot, SCp);
				free_slot(slot, hostdata);
				SCp->host_scribble = NULL;
				NCR_700_set_depth(SCp->device, 0);
				/* NOTE: deadlock potential here: we
				 * rely on mid-layer guarantees that
				 * scsi_done won't try to issue the
				 * command again otherwise we'll
				 * deadlock on the
				 * hostdata->state_lock */
				SCp->result = DID_RESET << 16;
				SCp->scsi_done(SCp);
			}
			mdelay(25);
			NCR_700_chip_setup(host);

			hostdata->state = NCR_700_HOST_FREE;
			hostdata->cmd = NULL;
			/* signal back if this was an eh induced reset */
			if(hostdata->eh_complete != NULL)
				complete(hostdata->eh_complete);
			goto out_unlock;
		} else if(sstat0 & SELECTION_TIMEOUT) {
			DEBUG(("scsi%d: (%d:%d) selection timeout\n",
			       host->host_no, pun, lun));
			NCR_700_scsi_done(hostdata, SCp, DID_NO_CONNECT<<16);
		} else if(sstat0 & PHASE_MISMATCH) {
			struct NCR_700_command_slot *slot = (SCp == NULL) ? NULL :
				(struct NCR_700_command_slot *)SCp->host_scribble;

			if(dsp == Ent_SendMessage + 8 + hostdata->pScript) {
				/* It wants to reply to some part of
				 * our message */
#ifdef NCR_700_DEBUG
				__u32 temp = NCR_700_readl(host, TEMP_REG);
				int count = (hostdata->script[Ent_SendMessage/4] & 0xffffff) - ((NCR_700_readl(host, DBC_REG) & 0xffffff) + NCR_700_data_residual(host));
				printk("scsi%d (%d:%d) PHASE MISMATCH IN SEND MESSAGE %d remain, return %p[%04x], phase %s\n", host->host_no, pun, lun, count, (void *)temp, temp - hostdata->pScript, sbcl_to_string(NCR_700_readb(host, SBCL_REG)));
#endif
				resume_offset = hostdata->pScript + Ent_SendMessagePhaseMismatch;
			} else if(dsp >= to32bit(&slot->pSG[0].ins) &&
				  dsp <= to32bit(&slot->pSG[NCR_700_SG_SEGMENTS].ins)) {
				int data_transfer = NCR_700_readl(host, DBC_REG) & 0xffffff;
				int SGcount = (dsp - to32bit(&slot->pSG[0].ins))/sizeof(struct NCR_700_SG_List);
				int residual = NCR_700_data_residual(host);
				int i;
#ifdef NCR_700_DEBUG
				__u32 naddr = NCR_700_readl(host, DNAD_REG);

				printk("scsi%d: (%d:%d) Expected phase mismatch in slot->SG[%d], transferred 0x%x\n",
				       host->host_no, pun, lun,
				       SGcount, data_transfer);
				scsi_print_command(SCp);
				if(residual) {
					printk("scsi%d: (%d:%d) Expected phase mismatch in slot->SG[%d], transferred 0x%x, residual %d\n",
				       host->host_no, pun, lun,
				       SGcount, data_transfer, residual);
				}
#endif
				data_transfer += residual;

				if(data_transfer != 0) {
					int count; 
					__u32 pAddr;

					SGcount--;

					count = (bS_to_cpu(slot->SG[SGcount].ins) & 0x00ffffff);
					DEBUG(("DATA TRANSFER MISMATCH, count = %d, transferred %d\n", count, count-data_transfer));
					slot->SG[SGcount].ins &= bS_to_host(0xff000000);
					slot->SG[SGcount].ins |= bS_to_host(data_transfer);
					pAddr = bS_to_cpu(slot->SG[SGcount].pAddr);
					pAddr += (count - data_transfer);
#ifdef NCR_700_DEBUG
					if(pAddr != naddr) {
						printk("scsi%d (%d:%d) transfer mismatch pAddr=%lx, naddr=%lx, data_transfer=%d, residual=%d\n", host->host_no, pun, lun, (unsigned long)pAddr, (unsigned long)naddr, data_transfer, residual);
					}
#endif
					slot->SG[SGcount].pAddr = bS_to_host(pAddr);
				}
				/* set the executed moves to nops */
				for(i=0; i<SGcount; i++) {
					slot->SG[i].ins = bS_to_host(SCRIPT_NOP);
					slot->SG[i].pAddr = 0;
				}
				dma_cache_sync(slot->SG, sizeof(slot->SG), DMA_TO_DEVICE);
				/* and pretend we disconnected after
				 * the command phase */
				resume_offset = hostdata->pScript + Ent_MsgInDuringData;
				/* make sure all the data is flushed */
				NCR_700_flush_fifo(host);
			} else {
				__u8 sbcl = NCR_700_readb(host, SBCL_REG);
				printk(KERN_ERR "scsi%d: (%d:%d) phase mismatch at %04x, phase %s\n",
				       host->host_no, pun, lun, dsp - hostdata->pScript, sbcl_to_string(sbcl));
				NCR_700_internal_bus_reset(host);
			}

		} else if(sstat0 & SCSI_GROSS_ERROR) {
			printk(KERN_ERR "scsi%d: (%d:%d) GROSS ERROR\n",
			       host->host_no, pun, lun);
			NCR_700_scsi_done(hostdata, SCp, DID_ERROR<<16);
		} else if(sstat0 & PARITY_ERROR) {
			printk(KERN_ERR "scsi%d: (%d:%d) PARITY ERROR\n",
			       host->host_no, pun, lun);
			NCR_700_scsi_done(hostdata, SCp, DID_ERROR<<16);
		} else if(dstat & SCRIPT_INT_RECEIVED) {
			DEBUG(("scsi%d: (%d:%d) ====>SCRIPT INTERRUPT<====\n",
			       host->host_no, pun, lun));
			resume_offset = process_script_interrupt(dsps, dsp, SCp, host, hostdata);
		} else if(dstat & (ILGL_INST_DETECTED)) {
			printk(KERN_ERR "scsi%d: (%d:%d) Illegal Instruction detected at 0x%08x[0x%x]!!!\n"
			       "         Please email James.Bottomley@HansenPartnership.com with the details\n",
			       host->host_no, pun, lun,
			       dsp, dsp - hostdata->pScript);
			NCR_700_scsi_done(hostdata, SCp, DID_ERROR<<16);
		} else if(dstat & (WATCH_DOG_INTERRUPT|ABORTED)) {
			printk(KERN_ERR "scsi%d: (%d:%d) serious DMA problem, dstat=%02x\n",
			       host->host_no, pun, lun, dstat);
			NCR_700_scsi_done(hostdata, SCp, DID_ERROR<<16);
		}

		
		/* NOTE: selection interrupt processing MUST occur
		 * after script interrupt processing to correctly cope
		 * with the case where we process a disconnect and
		 * then get reselected before we process the
		 * disconnection */
		if(sstat0 & SELECTED) {
			/* FIXME: It currently takes at least FOUR
			 * interrupts to complete a command that
			 * disconnects: one for the disconnect, one
			 * for the reselection, one to get the
			 * reselection data and one to complete the
			 * command.  If we guess the reselected
			 * command here and prepare it, we only need
			 * to get a reselection data interrupt if we
			 * guessed wrongly.  Since the interrupt
			 * overhead is much greater than the command
			 * setup, this would be an efficient
			 * optimisation particularly as we probably
			 * only have one outstanding command on a
			 * target most of the time */

			resume_offset = process_selection(host, dsp);

		}

	}

	if(resume_offset) {
		if(hostdata->state != NCR_700_HOST_BUSY) {
			printk(KERN_ERR "scsi%d: Driver error: resume at 0x%08x [0x%04x] with non busy host!\n",
			       host->host_no, resume_offset, resume_offset - hostdata->pScript);
			hostdata->state = NCR_700_HOST_BUSY;
		}

		DEBUG(("Attempting to resume at %x\n", resume_offset));
		NCR_700_clear_fifo(host);
		NCR_700_writel(resume_offset, host, DSP_REG);
	} 
	/* There is probably a technical no-no about this: If we're a
	 * shared interrupt and we got this interrupt because the
	 * other device needs servicing not us, we're still going to
	 * check our queued commands here---of course, there shouldn't
	 * be any outstanding.... */
	if(hostdata->state == NCR_700_HOST_FREE) {
		int i;

		for(i = 0; i < NCR_700_COMMAND_SLOTS_PER_HOST; i++) {
			/* fairness: always run the queue from the last
			 * position we left off */
			int j = (i + hostdata->saved_slot_position)
				% NCR_700_COMMAND_SLOTS_PER_HOST;
			
			if(hostdata->slots[j].state != NCR_700_SLOT_QUEUED)
				continue;
			if(NCR_700_start_command(hostdata->slots[j].cmnd)) {
				DEBUG(("scsi%d: Issuing saved command slot %p, cmd %p\t\n",
				       host->host_no, &hostdata->slots[j],
				       hostdata->slots[j].cmnd));
				hostdata->saved_slot_position = j + 1;
			}

			break;
		}
	}
 out_unlock:
	spin_unlock_irqrestore(host->host_lock, flags);
	return IRQ_RETVAL(handled);
}

STATIC int
NCR_700_queuecommand(struct scsi_cmnd *SCp, void (*done)(struct scsi_cmnd *))
{
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)SCp->device->host->hostdata[0];
	__u32 move_ins;
	enum dma_data_direction direction;
	struct NCR_700_command_slot *slot;

	if(hostdata->command_slot_count >= NCR_700_COMMAND_SLOTS_PER_HOST) {
		/* We're over our allocation, this should never happen
		 * since we report the max allocation to the mid layer */
		printk(KERN_WARNING "scsi%d: Command depth has gone over queue depth\n", SCp->device->host->host_no);
		return 1;
	}
	/* check for untagged commands.  We cannot have any outstanding
	 * commands if we accept them.  Commands could be untagged because:
	 *
	 * - The tag negotiated bitmap is clear
	 * - The blk layer sent and untagged command
	 */
	if(NCR_700_get_depth(SCp->device) != 0
	   && (!(hostdata->tag_negotiated & (1<<scmd_id(SCp)))
	       || !blk_rq_tagged(SCp->request))) {
		CDEBUG(KERN_ERR, SCp, "has non zero depth %d\n",
		       NCR_700_get_depth(SCp->device));
		return SCSI_MLQUEUE_DEVICE_BUSY;
	}
	if(NCR_700_get_depth(SCp->device) >= SCp->device->queue_depth) {
		CDEBUG(KERN_ERR, SCp, "has max tag depth %d\n",
		       NCR_700_get_depth(SCp->device));
		return SCSI_MLQUEUE_DEVICE_BUSY;
	}
	NCR_700_set_depth(SCp->device, NCR_700_get_depth(SCp->device) + 1);

	/* begin the command here */
	/* no need to check for NULL, test for command_slot_count above
	 * ensures a slot is free */
	slot = find_empty_slot(hostdata);

	slot->cmnd = SCp;

	SCp->scsi_done = done;
	SCp->host_scribble = (unsigned char *)slot;
	SCp->SCp.ptr = NULL;
	SCp->SCp.buffer = NULL;

#ifdef NCR_700_DEBUG
	printk("53c700: scsi%d, command ", SCp->device->host->host_no);
	scsi_print_command(SCp);
#endif
	if(blk_rq_tagged(SCp->request)
	   && (hostdata->tag_negotiated &(1<<scmd_id(SCp))) == 0
	   && NCR_700_get_tag_neg_state(SCp->device) == NCR_700_START_TAG_NEGOTIATION) {
		scmd_printk(KERN_ERR, SCp, "Enabling Tag Command Queuing\n");
		hostdata->tag_negotiated |= (1<<scmd_id(SCp));
		NCR_700_set_tag_neg_state(SCp->device, NCR_700_DURING_TAG_NEGOTIATION);
	}

	/* here we may have to process an untagged command.  The gate
	 * above ensures that this will be the only one outstanding,
	 * so clear the tag negotiated bit.
	 *
	 * FIXME: This will royally screw up on multiple LUN devices
	 * */
	if(!blk_rq_tagged(SCp->request)
	   && (hostdata->tag_negotiated &(1<<scmd_id(SCp)))) {
		scmd_printk(KERN_INFO, SCp, "Disabling Tag Command Queuing\n");
		hostdata->tag_negotiated &= ~(1<<scmd_id(SCp));
	}

	if((hostdata->tag_negotiated &(1<<scmd_id(SCp)))
	   && scsi_get_tag_type(SCp->device)) {
		slot->tag = SCp->request->tag;
		CDEBUG(KERN_DEBUG, SCp, "sending out tag %d, slot %p\n",
		       slot->tag, slot);
	} else {
		slot->tag = SCSI_NO_TAG;
		/* must populate current_cmnd for scsi_find_tag to work */
		SCp->device->current_cmnd = SCp;
	}
	/* sanity check: some of the commands generated by the mid-layer
	 * have an eccentric idea of their sc_data_direction */
	if(!SCp->use_sg && !SCp->request_bufflen 
	   && SCp->sc_data_direction != DMA_NONE) {
#ifdef NCR_700_DEBUG
		printk("53c700: Command");
		scsi_print_command(SCp);
		printk("Has wrong data direction %d\n", SCp->sc_data_direction);
#endif
		SCp->sc_data_direction = DMA_NONE;
	}

	switch (SCp->cmnd[0]) {
	case REQUEST_SENSE:
		/* clear the internal sense magic */
		SCp->cmnd[6] = 0;
		/* fall through */
	default:
		/* OK, get it from the command */
		switch(SCp->sc_data_direction) {
		case DMA_BIDIRECTIONAL:
		default:
			printk(KERN_ERR "53c700: Unknown command for data direction ");
			scsi_print_command(SCp);
			
			move_ins = 0;
			break;
		case DMA_NONE:
			move_ins = 0;
			break;
		case DMA_FROM_DEVICE:
			move_ins = SCRIPT_MOVE_DATA_IN;
			break;
		case DMA_TO_DEVICE:
			move_ins = SCRIPT_MOVE_DATA_OUT;
			break;
		}
	}

	/* now build the scatter gather list */
	direction = SCp->sc_data_direction;
	if(move_ins != 0) {
		int i;
		int sg_count;
		dma_addr_t vPtr = 0;
		__u32 count = 0;

		if(SCp->use_sg) {
			sg_count = dma_map_sg(hostdata->dev, SCp->buffer,
					      SCp->use_sg, direction);
		} else {
			vPtr = dma_map_single(hostdata->dev,
					      SCp->request_buffer, 
					      SCp->request_bufflen,
					      direction);
			count = SCp->request_bufflen;
			slot->dma_handle = vPtr;
			sg_count = 1;
		}
			

		for(i = 0; i < sg_count; i++) {

			if(SCp->use_sg) {
				struct scatterlist *sg = SCp->buffer;

				vPtr = sg_dma_address(&sg[i]);
				count = sg_dma_len(&sg[i]);
			}

			slot->SG[i].ins = bS_to_host(move_ins | count);
			DEBUG((" scatter block %d: move %d[%08x] from 0x%lx\n",
			       i, count, slot->SG[i].ins, (unsigned long)vPtr));
			slot->SG[i].pAddr = bS_to_host(vPtr);
		}
		slot->SG[i].ins = bS_to_host(SCRIPT_RETURN);
		slot->SG[i].pAddr = 0;
		dma_cache_sync(slot->SG, sizeof(slot->SG), DMA_TO_DEVICE);
		DEBUG((" SETTING %08lx to %x\n",
		       (&slot->pSG[i].ins), 
		       slot->SG[i].ins));
	}
	slot->resume_offset = 0;
	slot->pCmd = dma_map_single(hostdata->dev, SCp->cmnd,
				    sizeof(SCp->cmnd), DMA_TO_DEVICE);
	NCR_700_start_command(SCp);
	return 0;
}

STATIC int
NCR_700_abort(struct scsi_cmnd * SCp)
{
	struct NCR_700_command_slot *slot;

	scmd_printk(KERN_INFO, SCp,
		"New error handler wants to abort command\n\t");
	scsi_print_command(SCp);

	slot = (struct NCR_700_command_slot *)SCp->host_scribble;

	if(slot == NULL)
		/* no outstanding command to abort */
		return SUCCESS;
	if(SCp->cmnd[0] == TEST_UNIT_READY) {
		/* FIXME: This is because of a problem in the new
		 * error handler.  When it is in error recovery, it
		 * will send a TUR to a device it thinks may still be
		 * showing a problem.  If the TUR isn't responded to,
		 * it will abort it and mark the device off line.
		 * Unfortunately, it does no other error recovery, so
		 * this would leave us with an outstanding command
		 * occupying a slot.  Rather than allow this to
		 * happen, we issue a bus reset to force all
		 * outstanding commands to terminate here. */
		NCR_700_internal_bus_reset(SCp->device->host);
		/* still drop through and return failed */
	}
	return FAILED;

}

STATIC int
NCR_700_bus_reset(struct scsi_cmnd * SCp)
{
	DECLARE_COMPLETION(complete);
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)SCp->device->host->hostdata[0];

	scmd_printk(KERN_INFO, SCp,
		"New error handler wants BUS reset, cmd %p\n\t", SCp);
	scsi_print_command(SCp);

	/* In theory, eh_complete should always be null because the
	 * eh is single threaded, but just in case we're handling a
	 * reset via sg or something */
	spin_lock_irq(SCp->device->host->host_lock);
	while (hostdata->eh_complete != NULL) {
		spin_unlock_irq(SCp->device->host->host_lock);
		msleep_interruptible(100);
		spin_lock_irq(SCp->device->host->host_lock);
	}

	hostdata->eh_complete = &complete;
	NCR_700_internal_bus_reset(SCp->device->host);

	spin_unlock_irq(SCp->device->host->host_lock);
	wait_for_completion(&complete);
	spin_lock_irq(SCp->device->host->host_lock);

	hostdata->eh_complete = NULL;
	/* Revalidate the transport parameters of the failing device */
	if(hostdata->fast)
		spi_schedule_dv_device(SCp->device);

	spin_unlock_irq(SCp->device->host->host_lock);
	return SUCCESS;
}

STATIC int
NCR_700_host_reset(struct scsi_cmnd * SCp)
{
	scmd_printk(KERN_INFO, SCp, "New error handler wants HOST reset\n\t");
	scsi_print_command(SCp);

	spin_lock_irq(SCp->device->host->host_lock);

	NCR_700_internal_bus_reset(SCp->device->host);
	NCR_700_chip_reset(SCp->device->host);

	spin_unlock_irq(SCp->device->host->host_lock);

	return SUCCESS;
}

STATIC void
NCR_700_set_period(struct scsi_target *STp, int period)
{
	struct Scsi_Host *SHp = dev_to_shost(STp->dev.parent);
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)SHp->hostdata[0];
	
	if(!hostdata->fast)
		return;

	if(period < hostdata->min_period)
		period = hostdata->min_period;

	spi_period(STp) = period;
	spi_flags(STp) &= ~(NCR_700_DEV_NEGOTIATED_SYNC |
			    NCR_700_DEV_BEGIN_SYNC_NEGOTIATION);
	spi_flags(STp) |= NCR_700_DEV_PRINT_SYNC_NEGOTIATION;
}

STATIC void
NCR_700_set_offset(struct scsi_target *STp, int offset)
{
	struct Scsi_Host *SHp = dev_to_shost(STp->dev.parent);
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)SHp->hostdata[0];
	int max_offset = hostdata->chip710
		? NCR_710_MAX_OFFSET : NCR_700_MAX_OFFSET;
	
	if(!hostdata->fast)
		return;

	if(offset > max_offset)
		offset = max_offset;

	/* if we're currently async, make sure the period is reasonable */
	if(spi_offset(STp) == 0 && (spi_period(STp) < hostdata->min_period ||
				    spi_period(STp) > 0xff))
		spi_period(STp) = hostdata->min_period;

	spi_offset(STp) = offset;
	spi_flags(STp) &= ~(NCR_700_DEV_NEGOTIATED_SYNC |
			    NCR_700_DEV_BEGIN_SYNC_NEGOTIATION);
	spi_flags(STp) |= NCR_700_DEV_PRINT_SYNC_NEGOTIATION;
}



STATIC int
NCR_700_slave_configure(struct scsi_device *SDp)
{
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)SDp->host->hostdata[0];

	/* to do here: allocate memory; build a queue_full list */
	if(SDp->tagged_supported) {
		scsi_set_tag_type(SDp, MSG_ORDERED_TAG);
		scsi_activate_tcq(SDp, NCR_700_DEFAULT_TAGS);
		NCR_700_set_tag_neg_state(SDp, NCR_700_START_TAG_NEGOTIATION);
	} else {
		/* initialise to default depth */
		scsi_adjust_queue_depth(SDp, 0, SDp->host->cmd_per_lun);
	}
	if(hostdata->fast) {
		/* Find the correct offset and period via domain validation */
		if (!spi_initial_dv(SDp->sdev_target))
			spi_dv_device(SDp);
	} else {
		spi_offset(SDp->sdev_target) = 0;
		spi_period(SDp->sdev_target) = 0;
	}
	return 0;
}

STATIC void
NCR_700_slave_destroy(struct scsi_device *SDp)
{
	/* to do here: deallocate memory */
}

static int
NCR_700_change_queue_depth(struct scsi_device *SDp, int depth)
{
	if (depth > NCR_700_MAX_TAGS)
		depth = NCR_700_MAX_TAGS;

	scsi_adjust_queue_depth(SDp, scsi_get_tag_type(SDp), depth);
	return depth;
}

static int NCR_700_change_queue_type(struct scsi_device *SDp, int tag_type)
{
	int change_tag = ((tag_type ==0 &&  scsi_get_tag_type(SDp) != 0)
			  || (tag_type != 0 && scsi_get_tag_type(SDp) == 0));
	struct NCR_700_Host_Parameters *hostdata = 
		(struct NCR_700_Host_Parameters *)SDp->host->hostdata[0];

	scsi_set_tag_type(SDp, tag_type);

	/* We have a global (per target) flag to track whether TCQ is
	 * enabled, so we'll be turning it off for the entire target here.
	 * our tag algorithm will fail if we mix tagged and untagged commands,
	 * so quiesce the device before doing this */
	if (change_tag)
		scsi_target_quiesce(SDp->sdev_target);

	if (!tag_type) {
		/* shift back to the default unqueued number of commands
		 * (the user can still raise this) */
		scsi_deactivate_tcq(SDp, SDp->host->cmd_per_lun);
		hostdata->tag_negotiated &= ~(1 << sdev_id(SDp));
	} else {
		/* Here, we cleared the negotiation flag above, so this
		 * will force the driver to renegotiate */
		scsi_activate_tcq(SDp, SDp->queue_depth);
		if (change_tag)
			NCR_700_set_tag_neg_state(SDp, NCR_700_START_TAG_NEGOTIATION);
	}
	if (change_tag)
		scsi_target_resume(SDp->sdev_target);

	return tag_type;
}

static ssize_t
NCR_700_show_active_tags(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct scsi_device *SDp = to_scsi_device(dev);

	return snprintf(buf, 20, "%d\n", NCR_700_get_depth(SDp));
}

static struct device_attribute NCR_700_active_tags_attr = {
	.attr = {
		.name =		"active_tags",
		.mode =		S_IRUGO,
	},
	.show = NCR_700_show_active_tags,
};

STATIC struct device_attribute *NCR_700_dev_attrs[] = {
	&NCR_700_active_tags_attr,
	NULL,
};

EXPORT_SYMBOL(NCR_700_detect);
EXPORT_SYMBOL(NCR_700_release);
EXPORT_SYMBOL(NCR_700_intr);

static struct spi_function_template NCR_700_transport_functions =  {
	.set_period	= NCR_700_set_period,
	.show_period	= 1,
	.set_offset	= NCR_700_set_offset,
	.show_offset	= 1,
};

static int __init NCR_700_init(void)
{
	NCR_700_transport_template = spi_attach_transport(&NCR_700_transport_functions);
	if(!NCR_700_transport_template)
		return -ENODEV;
	return 0;
}

static void __exit NCR_700_exit(void)
{
	spi_release_transport(NCR_700_transport_template);
}

module_init(NCR_700_init);
module_exit(NCR_700_exit);