summaryrefslogblamecommitdiffstats
path: root/drivers/scsi/sym53c8xx_2/sym_hipd.c
blob: 297deb817a5d2f7076706032f7286398f5edfecc (plain) (tree)
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814






































                                                                               

                       
                                                                 
 










                                            
                                          
















                                                                          

                                                                       



                                                       
 
                           
                     




                                                                                        
                                                   
 
                           
                     















































                                                                         
                          

                              
                          
































































                                                                         
                          































































                                                                              



                                  








































































































































































































                                                                                
                                                                                 





























































































































                                                                                   
                                                                














                                                     





























                                                                            






























                                                                            




                                                                                                    

                                                      



                          
                                                       
























































































                                                                             





                                                            












                                                                      

                                                           





















                                                                        



                                                                 




































                                                                            
                          















                                                             
                                    









                                                          
                                                             

























                                                                      

                                            
 
                                                     









































                                                                                








                                              

                                          
















                                                                             
                            
         





                                                 


      
                                            
 





                                                                























































































                                                                               
                   




























                                                                       
                                                                                   
 
                                                










































                                                                               



                                                          




                              
                                         

 
                                                
 
                                                




                                  
                                               

 



















































































                                                                          
                                                


































                                                          
                         





















































                                                                            















































                                                                                   
                                                  









                                                                          

                                                                           
                              
                                                            
                               
                                                             







                                     

                                                                              

                      
                                                                               

                      


                                                                             
                                                                     
                                                                       




















                                                                           
                                                                











































                                                                 

                                                                       






















































































































                                                                          
                                                                









                                                                  
                                                                












































                                                                     
                                                      
 


                                                      















































                                                              
                            



                                    
                                            




                                                                                  
                          





























                                                                                        
                                                         








                                                                  

                                                           






                                                                           
                                                     
                                            
                                                          
















                                                                       
                          





































                                                                           
                                          


















                                                                       








                                                                    













                                                                                
                                              































































































































                                                                                        






















                                                          






                                                                    
                                                  
 

                                                      




                                           








                                  
                                               










                                                           
                                                  



                                                                     





                                           









                                                                 
                                       










                                                                     
                                                  


                                                                 



                                          







                                                                  
                                       













































































































                                                                               
                                                 
 
                                                











                                                                                
                               




































                                                            


                                                                                  







































































































































































































































































































































































































































































































                                                                               
                                                  
 


                                                      

















                                                                          
                                                                        




                                                            
                                                               

























                                                               



                                                                   
                                                      
                                                
                 
































                                                                    
                                                        

                                                         
                                   














                                                                       
                                       
                                   






                                                                             
                                                            


                                                         
                                   








                                                               
                                               



                                               
                                   









                                                               
                        





                                                        
                                         




























                                                                                 
                                                                    





















































































































                                                                                    
                                                                 




                                                             
                                                               















                                                                          
                                                               

































































                                                                                      
                                                       













                                                                           
                                                            






































































































































































                                                                                
                                                                           







                                                                        
                                                                  
                    
                                                               
















































































































                                                                             
                                                                  









                                                                     
                                      



























                                                                    
                                             



















                                                                  
                                                                  





                                                                     

                                                                            






                                                           
                                                               


























































                                                                                     
                                                               















                                                                     
                                    









































































































                                                                                              
                                       






























































































                                                                             
                                             








                                                                    
                                                              



















                                                                    

                                         










































































































                                                                              
                                                    




























































































































                                                                                     
                                                               














































































































                                                                                    
                                                 











































                                                                                     

                                                                           






































































                                                                                         
                                           





































                                                                     
                                                                   

                                    

                                                                               


                                                           
                                            

                                 

                                                                       





                                                                     

                                                                   

                               
                                                             











                                                               
                                                                        










                                                                

                                                                             































































































                                                                           
                                                                           

























                                                                                
                                                                   














































































                                                                                         
         







                                                               

                                              











































                                                                              

                                                                    




























                                                                               
                         
                                    


































































                                                                            






















































































































































                                                                         
                                  

























                                                                               
                                            


















                                                           
                   
























                                                                              
 













                                                                         





                                                                       
                                                                





























                                                                             




































                                                                               




















































































                                                                                   


                                                          

                            


                                                                         



















                                                                         
                                                        


































































































                                                                                   
                                                       
































































































                                                                               
                                                        



























                                                            
                                       





































                                                             



                                                            
                                             


















                                                                   


























                                                                               
                                              


























































































                                                                                       
                                                                                 































                                                       
                                            
                                              




                                                                           











































































































                                                                            
                   












                                                                               
                                                                        










                                                                          

                                                                 






                                                           
/*
 * Device driver for the SYMBIOS/LSILOGIC 53C8XX and 53C1010 family 
 * of PCI-SCSI IO processors.
 *
 * Copyright (C) 1999-2001  Gerard Roudier <groudier@free.fr>
 * Copyright (c) 2003-2005  Matthew Wilcox <matthew@wil.cx>
 *
 * This driver is derived from the Linux sym53c8xx driver.
 * Copyright (C) 1998-2000  Gerard Roudier
 *
 * The sym53c8xx driver is derived from the ncr53c8xx driver that had been 
 * a port of the FreeBSD ncr driver to Linux-1.2.13.
 *
 * The original ncr driver has been written for 386bsd and FreeBSD by
 *         Wolfgang Stanglmeier        <wolf@cologne.de>
 *         Stefan Esser                <se@mi.Uni-Koeln.de>
 * Copyright (C) 1994  Wolfgang Stanglmeier
 *
 * Other major contributions:
 *
 * NVRAM detection and reading.
 * Copyright (C) 1997 Richard Waltham <dormouse@farsrobt.demon.co.uk>
 *
 *-----------------------------------------------------------------------------
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/slab.h>
#include <asm/param.h>		/* for timeouts in units of HZ */

#include "sym_glue.h"
#include "sym_nvram.h"

#if 0
#define SYM_DEBUG_GENERIC_SUPPORT
#endif

/*
 *  Needed function prototypes.
 */
static void sym_int_ma (struct sym_hcb *np);
static void sym_int_sir(struct sym_hcb *);
static struct sym_ccb *sym_alloc_ccb(struct sym_hcb *np);
static struct sym_ccb *sym_ccb_from_dsa(struct sym_hcb *np, u32 dsa);
static void sym_alloc_lcb_tags (struct sym_hcb *np, u_char tn, u_char ln);
static void sym_complete_error (struct sym_hcb *np, struct sym_ccb *cp);
static void sym_complete_ok (struct sym_hcb *np, struct sym_ccb *cp);
static int sym_compute_residual(struct sym_hcb *np, struct sym_ccb *cp);

/*
 *  Print a buffer in hexadecimal format with a ".\n" at end.
 */
static void sym_printl_hex(u_char *p, int n)
{
	while (n-- > 0)
		printf (" %x", *p++);
	printf (".\n");
}

static void sym_print_msg(struct sym_ccb *cp, char *label, u_char *msg)
{
	if (label)
		sym_print_addr(cp->cmd, "%s: ", label);
	else
		sym_print_addr(cp->cmd, "");

	spi_print_msg(msg);
	printf("\n");
}

static void sym_print_nego_msg(struct sym_hcb *np, int target, char *label, u_char *msg)
{
	struct sym_tcb *tp = &np->target[target];
	dev_info(&tp->starget->dev, "%s: ", label);

	spi_print_msg(msg);
	printf("\n");
}

/*
 *  Print something that tells about extended errors.
 */
void sym_print_xerr(struct scsi_cmnd *cmd, int x_status)
{
	if (x_status & XE_PARITY_ERR) {
		sym_print_addr(cmd, "unrecovered SCSI parity error.\n");
	}
	if (x_status & XE_EXTRA_DATA) {
		sym_print_addr(cmd, "extraneous data discarded.\n");
	}
	if (x_status & XE_BAD_PHASE) {
		sym_print_addr(cmd, "illegal scsi phase (4/5).\n");
	}
	if (x_status & XE_SODL_UNRUN) {
		sym_print_addr(cmd, "ODD transfer in DATA OUT phase.\n");
	}
	if (x_status & XE_SWIDE_OVRUN) {
		sym_print_addr(cmd, "ODD transfer in DATA IN phase.\n");
	}
}

/*
 *  Return a string for SCSI BUS mode.
 */
static char *sym_scsi_bus_mode(int mode)
{
	switch(mode) {
	case SMODE_HVD:	return "HVD";
	case SMODE_SE:	return "SE";
	case SMODE_LVD: return "LVD";
	}
	return "??";
}

/*
 *  Soft reset the chip.
 *
 *  Raising SRST when the chip is running may cause 
 *  problems on dual function chips (see below).
 *  On the other hand, LVD devices need some delay 
 *  to settle and report actual BUS mode in STEST4.
 */
static void sym_chip_reset (struct sym_hcb *np)
{
	OUTB(np, nc_istat, SRST);
	INB(np, nc_mbox1);
	udelay(10);
	OUTB(np, nc_istat, 0);
	INB(np, nc_mbox1);
	udelay(2000);	/* For BUS MODE to settle */
}

/*
 *  Really soft reset the chip.:)
 *
 *  Some 896 and 876 chip revisions may hang-up if we set 
 *  the SRST (soft reset) bit at the wrong time when SCRIPTS 
 *  are running.
 *  So, we need to abort the current operation prior to 
 *  soft resetting the chip.
 */
static void sym_soft_reset (struct sym_hcb *np)
{
	u_char istat = 0;
	int i;

	if (!(np->features & FE_ISTAT1) || !(INB(np, nc_istat1) & SCRUN))
		goto do_chip_reset;

	OUTB(np, nc_istat, CABRT);
	for (i = 100000 ; i ; --i) {
		istat = INB(np, nc_istat);
		if (istat & SIP) {
			INW(np, nc_sist);
		}
		else if (istat & DIP) {
			if (INB(np, nc_dstat) & ABRT)
				break;
		}
		udelay(5);
	}
	OUTB(np, nc_istat, 0);
	if (!i)
		printf("%s: unable to abort current chip operation, "
		       "ISTAT=0x%02x.\n", sym_name(np), istat);
do_chip_reset:
	sym_chip_reset(np);
}

/*
 *  Start reset process.
 *
 *  The interrupt handler will reinitialize the chip.
 */
static void sym_start_reset(struct sym_hcb *np)
{
	sym_reset_scsi_bus(np, 1);
}
 
int sym_reset_scsi_bus(struct sym_hcb *np, int enab_int)
{
	u32 term;
	int retv = 0;

	sym_soft_reset(np);	/* Soft reset the chip */
	if (enab_int)
		OUTW(np, nc_sien, RST);
	/*
	 *  Enable Tolerant, reset IRQD if present and 
	 *  properly set IRQ mode, prior to resetting the bus.
	 */
	OUTB(np, nc_stest3, TE);
	OUTB(np, nc_dcntl, (np->rv_dcntl & IRQM));
	OUTB(np, nc_scntl1, CRST);
	INB(np, nc_mbox1);
	udelay(200);

	if (!SYM_SETUP_SCSI_BUS_CHECK)
		goto out;
	/*
	 *  Check for no terminators or SCSI bus shorts to ground.
	 *  Read SCSI data bus, data parity bits and control signals.
	 *  We are expecting RESET to be TRUE and other signals to be 
	 *  FALSE.
	 */
	term =	INB(np, nc_sstat0);
	term =	((term & 2) << 7) + ((term & 1) << 17);	/* rst sdp0 */
	term |= ((INB(np, nc_sstat2) & 0x01) << 26) |	/* sdp1     */
		((INW(np, nc_sbdl) & 0xff)   << 9)  |	/* d7-0     */
		((INW(np, nc_sbdl) & 0xff00) << 10) |	/* d15-8    */
		INB(np, nc_sbcl);	/* req ack bsy sel atn msg cd io    */

	if (!np->maxwide)
		term &= 0x3ffff;

	if (term != (2<<7)) {
		printf("%s: suspicious SCSI data while resetting the BUS.\n",
			sym_name(np));
		printf("%s: %sdp0,d7-0,rst,req,ack,bsy,sel,atn,msg,c/d,i/o = "
			"0x%lx, expecting 0x%lx\n",
			sym_name(np),
			(np->features & FE_WIDE) ? "dp1,d15-8," : "",
			(u_long)term, (u_long)(2<<7));
		if (SYM_SETUP_SCSI_BUS_CHECK == 1)
			retv = 1;
	}
out:
	OUTB(np, nc_scntl1, 0);
	return retv;
}

/*
 *  Select SCSI clock frequency
 */
static void sym_selectclock(struct sym_hcb *np, u_char scntl3)
{
	/*
	 *  If multiplier not present or not selected, leave here.
	 */
	if (np->multiplier <= 1) {
		OUTB(np, nc_scntl3, scntl3);
		return;
	}

	if (sym_verbose >= 2)
		printf ("%s: enabling clock multiplier\n", sym_name(np));

	OUTB(np, nc_stest1, DBLEN);	   /* Enable clock multiplier */
	/*
	 *  Wait for the LCKFRQ bit to be set if supported by the chip.
	 *  Otherwise wait 50 micro-seconds (at least).
	 */
	if (np->features & FE_LCKFRQ) {
		int i = 20;
		while (!(INB(np, nc_stest4) & LCKFRQ) && --i > 0)
			udelay(20);
		if (!i)
			printf("%s: the chip cannot lock the frequency\n",
				sym_name(np));
	} else {
		INB(np, nc_mbox1);
		udelay(50+10);
	}
	OUTB(np, nc_stest3, HSC);		/* Halt the scsi clock	*/
	OUTB(np, nc_scntl3, scntl3);
	OUTB(np, nc_stest1, (DBLEN|DBLSEL));/* Select clock multiplier	*/
	OUTB(np, nc_stest3, 0x00);		/* Restart scsi clock 	*/
}


/*
 *  Determine the chip's clock frequency.
 *
 *  This is essential for the negotiation of the synchronous 
 *  transfer rate.
 *
 *  Note: we have to return the correct value.
 *  THERE IS NO SAFE DEFAULT VALUE.
 *
 *  Most NCR/SYMBIOS boards are delivered with a 40 Mhz clock.
 *  53C860 and 53C875 rev. 1 support fast20 transfers but 
 *  do not have a clock doubler and so are provided with a 
 *  80 MHz clock. All other fast20 boards incorporate a doubler 
 *  and so should be delivered with a 40 MHz clock.
 *  The recent fast40 chips (895/896/895A/1010) use a 40 Mhz base 
 *  clock and provide a clock quadrupler (160 Mhz).
 */

/*
 *  calculate SCSI clock frequency (in KHz)
 */
static unsigned getfreq (struct sym_hcb *np, int gen)
{
	unsigned int ms = 0;
	unsigned int f;

	/*
	 * Measure GEN timer delay in order 
	 * to calculate SCSI clock frequency
	 *
	 * This code will never execute too
	 * many loop iterations (if DELAY is 
	 * reasonably correct). It could get
	 * too low a delay (too high a freq.)
	 * if the CPU is slow executing the 
	 * loop for some reason (an NMI, for
	 * example). For this reason we will
	 * if multiple measurements are to be 
	 * performed trust the higher delay 
	 * (lower frequency returned).
	 */
	OUTW(np, nc_sien, 0);	/* mask all scsi interrupts */
	INW(np, nc_sist);	/* clear pending scsi interrupt */
	OUTB(np, nc_dien, 0);	/* mask all dma interrupts */
	INW(np, nc_sist);	/* another one, just to be sure :) */
	/*
	 * The C1010-33 core does not report GEN in SIST,
	 * if this interrupt is masked in SIEN.
	 * I don't know yet if the C1010-66 behaves the same way.
	 */
	if (np->features & FE_C10) {
		OUTW(np, nc_sien, GEN);
		OUTB(np, nc_istat1, SIRQD);
	}
	OUTB(np, nc_scntl3, 4);	   /* set pre-scaler to divide by 3 */
	OUTB(np, nc_stime1, 0);	   /* disable general purpose timer */
	OUTB(np, nc_stime1, gen);  /* set to nominal delay of 1<<gen * 125us */
	while (!(INW(np, nc_sist) & GEN) && ms++ < 100000)
		udelay(1000/4);    /* count in 1/4 of ms */
	OUTB(np, nc_stime1, 0);    /* disable general purpose timer */
	/*
	 * Undo C1010-33 specific settings.
	 */
	if (np->features & FE_C10) {
		OUTW(np, nc_sien, 0);
		OUTB(np, nc_istat1, 0);
	}
 	/*
 	 * set prescaler to divide by whatever 0 means
 	 * 0 ought to choose divide by 2, but appears
 	 * to set divide by 3.5 mode in my 53c810 ...
 	 */
 	OUTB(np, nc_scntl3, 0);

  	/*
 	 * adjust for prescaler, and convert into KHz 
  	 */
	f = ms ? ((1 << gen) * (4340*4)) / ms : 0;

	/*
	 * The C1010-33 result is biased by a factor 
	 * of 2/3 compared to earlier chips.
	 */
	if (np->features & FE_C10)
		f = (f * 2) / 3;

	if (sym_verbose >= 2)
		printf ("%s: Delay (GEN=%d): %u msec, %u KHz\n",
			sym_name(np), gen, ms/4, f);

	return f;
}

static unsigned sym_getfreq (struct sym_hcb *np)
{
	u_int f1, f2;
	int gen = 8;

	getfreq (np, gen);	/* throw away first result */
	f1 = getfreq (np, gen);
	f2 = getfreq (np, gen);
	if (f1 > f2) f1 = f2;		/* trust lower result	*/
	return f1;
}

/*
 *  Get/probe chip SCSI clock frequency
 */
static void sym_getclock (struct sym_hcb *np, int mult)
{
	unsigned char scntl3 = np->sv_scntl3;
	unsigned char stest1 = np->sv_stest1;
	unsigned f1;

	np->multiplier = 1;
	f1 = 40000;
	/*
	 *  True with 875/895/896/895A with clock multiplier selected
	 */
	if (mult > 1 && (stest1 & (DBLEN+DBLSEL)) == DBLEN+DBLSEL) {
		if (sym_verbose >= 2)
			printf ("%s: clock multiplier found\n", sym_name(np));
		np->multiplier = mult;
	}

	/*
	 *  If multiplier not found or scntl3 not 7,5,3,
	 *  reset chip and get frequency from general purpose timer.
	 *  Otherwise trust scntl3 BIOS setting.
	 */
	if (np->multiplier != mult || (scntl3 & 7) < 3 || !(scntl3 & 1)) {
		OUTB(np, nc_stest1, 0);		/* make sure doubler is OFF */
		f1 = sym_getfreq (np);

		if (sym_verbose)
			printf ("%s: chip clock is %uKHz\n", sym_name(np), f1);

		if	(f1 <	45000)		f1 =  40000;
		else if (f1 <	55000)		f1 =  50000;
		else				f1 =  80000;

		if (f1 < 80000 && mult > 1) {
			if (sym_verbose >= 2)
				printf ("%s: clock multiplier assumed\n",
					sym_name(np));
			np->multiplier	= mult;
		}
	} else {
		if	((scntl3 & 7) == 3)	f1 =  40000;
		else if	((scntl3 & 7) == 5)	f1 =  80000;
		else 				f1 = 160000;

		f1 /= np->multiplier;
	}

	/*
	 *  Compute controller synchronous parameters.
	 */
	f1		*= np->multiplier;
	np->clock_khz	= f1;
}

/*
 *  Get/probe PCI clock frequency
 */
static int sym_getpciclock (struct sym_hcb *np)
{
	int f = 0;

	/*
	 *  For now, we only need to know about the actual 
	 *  PCI BUS clock frequency for C1010-66 chips.
	 */
#if 1
	if (np->features & FE_66MHZ) {
#else
	if (1) {
#endif
		OUTB(np, nc_stest1, SCLK); /* Use the PCI clock as SCSI clock */
		f = sym_getfreq(np);
		OUTB(np, nc_stest1, 0);
	}
	np->pciclk_khz = f;

	return f;
}

/*
 *  SYMBIOS chip clock divisor table.
 *
 *  Divisors are multiplied by 10,000,000 in order to make 
 *  calculations more simple.
 */
#define _5M 5000000
static const u32 div_10M[] = {2*_5M, 3*_5M, 4*_5M, 6*_5M, 8*_5M, 12*_5M, 16*_5M};

/*
 *  Get clock factor and sync divisor for a given 
 *  synchronous factor period.
 */
static int 
sym_getsync(struct sym_hcb *np, u_char dt, u_char sfac, u_char *divp, u_char *fakp)
{
	u32	clk = np->clock_khz;	/* SCSI clock frequency in kHz	*/
	int	div = np->clock_divn;	/* Number of divisors supported	*/
	u32	fak;			/* Sync factor in sxfer		*/
	u32	per;			/* Period in tenths of ns	*/
	u32	kpc;			/* (per * clk)			*/
	int	ret;

	/*
	 *  Compute the synchronous period in tenths of nano-seconds
	 */
	if (dt && sfac <= 9)	per = 125;
	else if	(sfac <= 10)	per = 250;
	else if	(sfac == 11)	per = 303;
	else if	(sfac == 12)	per = 500;
	else			per = 40 * sfac;
	ret = per;

	kpc = per * clk;
	if (dt)
		kpc <<= 1;

	/*
	 *  For earliest C10 revision 0, we cannot use extra 
	 *  clocks for the setting of the SCSI clocking.
	 *  Note that this limits the lowest sync data transfer 
	 *  to 5 Mega-transfers per second and may result in
	 *  using higher clock divisors.
	 */
#if 1
	if ((np->features & (FE_C10|FE_U3EN)) == FE_C10) {
		/*
		 *  Look for the lowest clock divisor that allows an 
		 *  output speed not faster than the period.
		 */
		while (div > 0) {
			--div;
			if (kpc > (div_10M[div] << 2)) {
				++div;
				break;
			}
		}
		fak = 0;			/* No extra clocks */
		if (div == np->clock_divn) {	/* Are we too fast ? */
			ret = -1;
		}
		*divp = div;
		*fakp = fak;
		return ret;
	}
#endif

	/*
	 *  Look for the greatest clock divisor that allows an 
	 *  input speed faster than the period.
	 */
	while (div-- > 0)
		if (kpc >= (div_10M[div] << 2)) break;

	/*
	 *  Calculate the lowest clock factor that allows an output 
	 *  speed not faster than the period, and the max output speed.
	 *  If fak >= 1 we will set both XCLKH_ST and XCLKH_DT.
	 *  If fak >= 2 we will also set XCLKS_ST and XCLKS_DT.
	 */
	if (dt) {
		fak = (kpc - 1) / (div_10M[div] << 1) + 1 - 2;
		/* ret = ((2+fak)*div_10M[div])/np->clock_khz; */
	} else {
		fak = (kpc - 1) / div_10M[div] + 1 - 4;
		/* ret = ((4+fak)*div_10M[div])/np->clock_khz; */
	}

	/*
	 *  Check against our hardware limits, or bugs :).
	 */
	if (fak > 2) {
		fak = 2;
		ret = -1;
	}

	/*
	 *  Compute and return sync parameters.
	 */
	*divp = div;
	*fakp = fak;

	return ret;
}

/*
 *  SYMBIOS chips allow burst lengths of 2, 4, 8, 16, 32, 64,
 *  128 transfers. All chips support at least 16 transfers 
 *  bursts. The 825A, 875 and 895 chips support bursts of up 
 *  to 128 transfers and the 895A and 896 support bursts of up
 *  to 64 transfers. All other chips support up to 16 
 *  transfers bursts.
 *
 *  For PCI 32 bit data transfers each transfer is a DWORD.
 *  It is a QUADWORD (8 bytes) for PCI 64 bit data transfers.
 *
 *  We use log base 2 (burst length) as internal code, with 
 *  value 0 meaning "burst disabled".
 */

/*
 *  Burst length from burst code.
 */
#define burst_length(bc) (!(bc))? 0 : 1 << (bc)

/*
 *  Burst code from io register bits.
 */
#define burst_code(dmode, ctest4, ctest5) \
	(ctest4) & 0x80? 0 : (((dmode) & 0xc0) >> 6) + ((ctest5) & 0x04) + 1

/*
 *  Set initial io register bits from burst code.
 */
static inline void sym_init_burst(struct sym_hcb *np, u_char bc)
{
	np->rv_ctest4	&= ~0x80;
	np->rv_dmode	&= ~(0x3 << 6);
	np->rv_ctest5	&= ~0x4;

	if (!bc) {
		np->rv_ctest4	|= 0x80;
	}
	else {
		--bc;
		np->rv_dmode	|= ((bc & 0x3) << 6);
		np->rv_ctest5	|= (bc & 0x4);
	}
}

/*
 *  Save initial settings of some IO registers.
 *  Assumed to have been set by BIOS.
 *  We cannot reset the chip prior to reading the 
 *  IO registers, since informations will be lost.
 *  Since the SCRIPTS processor may be running, this 
 *  is not safe on paper, but it seems to work quite 
 *  well. :)
 */
static void sym_save_initial_setting (struct sym_hcb *np)
{
	np->sv_scntl0	= INB(np, nc_scntl0) & 0x0a;
	np->sv_scntl3	= INB(np, nc_scntl3) & 0x07;
	np->sv_dmode	= INB(np, nc_dmode)  & 0xce;
	np->sv_dcntl	= INB(np, nc_dcntl)  & 0xa8;
	np->sv_ctest3	= INB(np, nc_ctest3) & 0x01;
	np->sv_ctest4	= INB(np, nc_ctest4) & 0x80;
	np->sv_gpcntl	= INB(np, nc_gpcntl);
	np->sv_stest1	= INB(np, nc_stest1);
	np->sv_stest2	= INB(np, nc_stest2) & 0x20;
	np->sv_stest4	= INB(np, nc_stest4);
	if (np->features & FE_C10) {	/* Always large DMA fifo + ultra3 */
		np->sv_scntl4	= INB(np, nc_scntl4);
		np->sv_ctest5	= INB(np, nc_ctest5) & 0x04;
	}
	else
		np->sv_ctest5	= INB(np, nc_ctest5) & 0x24;
}

/*
 *  Set SCSI BUS mode.
 *  - LVD capable chips (895/895A/896/1010) report the current BUS mode
 *    through the STEST4 IO register.
 *  - For previous generation chips (825/825A/875), the user has to tell us
 *    how to check against HVD, since a 100% safe algorithm is not possible.
 */
static void sym_set_bus_mode(struct sym_hcb *np, struct sym_nvram *nvram)
{
	if (np->scsi_mode)
		return;

	np->scsi_mode = SMODE_SE;
	if (np->features & (FE_ULTRA2|FE_ULTRA3))
		np->scsi_mode = (np->sv_stest4 & SMODE);
	else if	(np->features & FE_DIFF) {
		if (SYM_SETUP_SCSI_DIFF == 1) {
			if (np->sv_scntl3) {
				if (np->sv_stest2 & 0x20)
					np->scsi_mode = SMODE_HVD;
			} else if (nvram->type == SYM_SYMBIOS_NVRAM) {
				if (!(INB(np, nc_gpreg) & 0x08))
					np->scsi_mode = SMODE_HVD;
			}
		} else if (SYM_SETUP_SCSI_DIFF == 2)
			np->scsi_mode = SMODE_HVD;
	}
	if (np->scsi_mode == SMODE_HVD)
		np->rv_stest2 |= 0x20;
}

/*
 *  Prepare io register values used by sym_start_up() 
 *  according to selected and supported features.
 */
static int sym_prepare_setting(struct Scsi_Host *shost, struct sym_hcb *np, struct sym_nvram *nvram)
{
	struct sym_data *sym_data = shost_priv(shost);
	struct pci_dev *pdev = sym_data->pdev;
	u_char	burst_max;
	u32	period;
	int i;

	np->maxwide = (np->features & FE_WIDE) ? 1 : 0;

	/*
	 *  Guess the frequency of the chip's clock.
	 */
	if	(np->features & (FE_ULTRA3 | FE_ULTRA2))
		np->clock_khz = 160000;
	else if	(np->features & FE_ULTRA)
		np->clock_khz = 80000;
	else
		np->clock_khz = 40000;

	/*
	 *  Get the clock multiplier factor.
 	 */
	if	(np->features & FE_QUAD)
		np->multiplier	= 4;
	else if	(np->features & FE_DBLR)
		np->multiplier	= 2;
	else
		np->multiplier	= 1;

	/*
	 *  Measure SCSI clock frequency for chips 
	 *  it may vary from assumed one.
	 */
	if (np->features & FE_VARCLK)
		sym_getclock(np, np->multiplier);

	/*
	 * Divisor to be used for async (timer pre-scaler).
	 */
	i = np->clock_divn - 1;
	while (--i >= 0) {
		if (10ul * SYM_CONF_MIN_ASYNC * np->clock_khz > div_10M[i]) {
			++i;
			break;
		}
	}
	np->rv_scntl3 = i+1;

	/*
	 * The C1010 uses hardwired divisors for async.
	 * So, we just throw away, the async. divisor.:-)
	 */
	if (np->features & FE_C10)
		np->rv_scntl3 = 0;

	/*
	 * Minimum synchronous period factor supported by the chip.
	 * Btw, 'period' is in tenths of nanoseconds.
	 */
	period = (4 * div_10M[0] + np->clock_khz - 1) / np->clock_khz;

	if	(period <= 250)		np->minsync = 10;
	else if	(period <= 303)		np->minsync = 11;
	else if	(period <= 500)		np->minsync = 12;
	else				np->minsync = (period + 40 - 1) / 40;

	/*
	 * Check against chip SCSI standard support (SCSI-2,ULTRA,ULTRA2).
	 */
	if	(np->minsync < 25 &&
		 !(np->features & (FE_ULTRA|FE_ULTRA2|FE_ULTRA3)))
		np->minsync = 25;
	else if	(np->minsync < 12 &&
		 !(np->features & (FE_ULTRA2|FE_ULTRA3)))
		np->minsync = 12;

	/*
	 * Maximum synchronous period factor supported by the chip.
	 */
	period = (11 * div_10M[np->clock_divn - 1]) / (4 * np->clock_khz);
	np->maxsync = period > 2540 ? 254 : period / 10;

	/*
	 * If chip is a C1010, guess the sync limits in DT mode.
	 */
	if ((np->features & (FE_C10|FE_ULTRA3)) == (FE_C10|FE_ULTRA3)) {
		if (np->clock_khz == 160000) {
			np->minsync_dt = 9;
			np->maxsync_dt = 50;
			np->maxoffs_dt = nvram->type ? 62 : 31;
		}
	}
	
	/*
	 *  64 bit addressing  (895A/896/1010) ?
	 */
	if (np->features & FE_DAC) {
		if (!use_dac(np))
			np->rv_ccntl1 |= (DDAC);
		else if (SYM_CONF_DMA_ADDRESSING_MODE == 1)
			np->rv_ccntl1 |= (XTIMOD | EXTIBMV);
		else if (SYM_CONF_DMA_ADDRESSING_MODE == 2)
			np->rv_ccntl1 |= (0 | EXTIBMV);
	}

	/*
	 *  Phase mismatch handled by SCRIPTS (895A/896/1010) ?
  	 */
	if (np->features & FE_NOPM)
		np->rv_ccntl0	|= (ENPMJ);

 	/*
	 *  C1010-33 Errata: Part Number:609-039638 (rev. 1) is fixed.
	 *  In dual channel mode, contention occurs if internal cycles
	 *  are used. Disable internal cycles.
	 */
	if (pdev->device == PCI_DEVICE_ID_LSI_53C1010_33 &&
	    pdev->revision < 0x1)
		np->rv_ccntl0	|=  DILS;

	/*
	 *  Select burst length (dwords)
	 */
	burst_max	= SYM_SETUP_BURST_ORDER;
	if (burst_max == 255)
		burst_max = burst_code(np->sv_dmode, np->sv_ctest4,
				       np->sv_ctest5);
	if (burst_max > 7)
		burst_max = 7;
	if (burst_max > np->maxburst)
		burst_max = np->maxburst;

	/*
	 *  DEL 352 - 53C810 Rev x11 - Part Number 609-0392140 - ITEM 2.
	 *  This chip and the 860 Rev 1 may wrongly use PCI cache line 
	 *  based transactions on LOAD/STORE instructions. So we have 
	 *  to prevent these chips from using such PCI transactions in 
	 *  this driver. The generic ncr driver that does not use 
	 *  LOAD/STORE instructions does not need this work-around.
	 */
	if ((pdev->device == PCI_DEVICE_ID_NCR_53C810 &&
	     pdev->revision >= 0x10 && pdev->revision <= 0x11) ||
	    (pdev->device == PCI_DEVICE_ID_NCR_53C860 &&
	     pdev->revision <= 0x1))
		np->features &= ~(FE_WRIE|FE_ERL|FE_ERMP);

	/*
	 *  Select all supported special features.
	 *  If we are using on-board RAM for scripts, prefetch (PFEN) 
	 *  does not help, but burst op fetch (BOF) does.
	 *  Disabling PFEN makes sure BOF will be used.
	 */
	if (np->features & FE_ERL)
		np->rv_dmode	|= ERL;		/* Enable Read Line */
	if (np->features & FE_BOF)
		np->rv_dmode	|= BOF;		/* Burst Opcode Fetch */
	if (np->features & FE_ERMP)
		np->rv_dmode	|= ERMP;	/* Enable Read Multiple */
#if 1
	if ((np->features & FE_PFEN) && !np->ram_ba)
#else
	if (np->features & FE_PFEN)
#endif
		np->rv_dcntl	|= PFEN;	/* Prefetch Enable */
	if (np->features & FE_CLSE)
		np->rv_dcntl	|= CLSE;	/* Cache Line Size Enable */
	if (np->features & FE_WRIE)
		np->rv_ctest3	|= WRIE;	/* Write and Invalidate */
	if (np->features & FE_DFS)
		np->rv_ctest5	|= DFS;		/* Dma Fifo Size */

	/*
	 *  Select some other
	 */
	np->rv_ctest4	|= MPEE; /* Master parity checking */
	np->rv_scntl0	|= 0x0a; /*  full arb., ena parity, par->ATN  */

	/*
	 *  Get parity checking, host ID and verbose mode from NVRAM
	 */
	np->myaddr = 255;
	np->scsi_mode = 0;
	sym_nvram_setup_host(shost, np, nvram);

	/*
	 *  Get SCSI addr of host adapter (set by bios?).
	 */
	if (np->myaddr == 255) {
		np->myaddr = INB(np, nc_scid) & 0x07;
		if (!np->myaddr)
			np->myaddr = SYM_SETUP_HOST_ID;
	}

	/*
	 *  Prepare initial io register bits for burst length
	 */
	sym_init_burst(np, burst_max);

	sym_set_bus_mode(np, nvram);

	/*
	 *  Set LED support from SCRIPTS.
	 *  Ignore this feature for boards known to use a 
	 *  specific GPIO wiring and for the 895A, 896 
	 *  and 1010 that drive the LED directly.
	 */
	if ((SYM_SETUP_SCSI_LED || 
	     (nvram->type == SYM_SYMBIOS_NVRAM ||
	      (nvram->type == SYM_TEKRAM_NVRAM &&
	       pdev->device == PCI_DEVICE_ID_NCR_53C895))) &&
	    !(np->features & FE_LEDC) && !(np->sv_gpcntl & 0x01))
		np->features |= FE_LED0;

	/*
	 *  Set irq mode.
	 */
	switch(SYM_SETUP_IRQ_MODE & 3) {
	case 2:
		np->rv_dcntl	|= IRQM;
		break;
	case 1:
		np->rv_dcntl	|= (np->sv_dcntl & IRQM);
		break;
	default:
		break;
	}

	/*
	 *  Configure targets according to driver setup.
	 *  If NVRAM present get targets setup from NVRAM.
	 */
	for (i = 0 ; i < SYM_CONF_MAX_TARGET ; i++) {
		struct sym_tcb *tp = &np->target[i];

		tp->usrflags |= (SYM_DISC_ENABLED | SYM_TAGS_ENABLED);
		tp->usrtags = SYM_SETUP_MAX_TAG;
		tp->usr_width = np->maxwide;
		tp->usr_period = 9;

		sym_nvram_setup_target(tp, i, nvram);

		if (!tp->usrtags)
			tp->usrflags &= ~SYM_TAGS_ENABLED;
	}

	/*
	 *  Let user know about the settings.
	 */
	printf("%s: %s, ID %d, Fast-%d, %s, %s\n", sym_name(np),
		sym_nvram_type(nvram), np->myaddr,
		(np->features & FE_ULTRA3) ? 80 : 
		(np->features & FE_ULTRA2) ? 40 : 
		(np->features & FE_ULTRA)  ? 20 : 10,
		sym_scsi_bus_mode(np->scsi_mode),
		(np->rv_scntl0 & 0xa)	? "parity checking" : "NO parity");
	/*
	 *  Tell him more on demand.
	 */
	if (sym_verbose) {
		printf("%s: %s IRQ line driver%s\n",
			sym_name(np),
			np->rv_dcntl & IRQM ? "totem pole" : "open drain",
			np->ram_ba ? ", using on-chip SRAM" : "");
		printf("%s: using %s firmware.\n", sym_name(np), np->fw_name);
		if (np->features & FE_NOPM)
			printf("%s: handling phase mismatch from SCRIPTS.\n", 
			       sym_name(np));
	}
	/*
	 *  And still more.
	 */
	if (sym_verbose >= 2) {
		printf ("%s: initial SCNTL3/DMODE/DCNTL/CTEST3/4/5 = "
			"(hex) %02x/%02x/%02x/%02x/%02x/%02x\n",
			sym_name(np), np->sv_scntl3, np->sv_dmode, np->sv_dcntl,
			np->sv_ctest3, np->sv_ctest4, np->sv_ctest5);

		printf ("%s: final   SCNTL3/DMODE/DCNTL/CTEST3/4/5 = "
			"(hex) %02x/%02x/%02x/%02x/%02x/%02x\n",
			sym_name(np), np->rv_scntl3, np->rv_dmode, np->rv_dcntl,
			np->rv_ctest3, np->rv_ctest4, np->rv_ctest5);
	}

	return 0;
}

/*
 *  Test the pci bus snoop logic :-(
 *
 *  Has to be called with interrupts disabled.
 */
#ifdef CONFIG_SCSI_SYM53C8XX_MMIO
static int sym_regtest(struct sym_hcb *np)
{
	register volatile u32 data;
	/*
	 *  chip registers may NOT be cached.
	 *  write 0xffffffff to a read only register area,
	 *  and try to read it back.
	 */
	data = 0xffffffff;
	OUTL(np, nc_dstat, data);
	data = INL(np, nc_dstat);
#if 1
	if (data == 0xffffffff) {
#else
	if ((data & 0xe2f0fffd) != 0x02000080) {
#endif
		printf ("CACHE TEST FAILED: reg dstat-sstat2 readback %x.\n",
			(unsigned) data);
		return 0x10;
	}
	return 0;
}
#else
static inline int sym_regtest(struct sym_hcb *np)
{
	return 0;
}
#endif

static int sym_snooptest(struct sym_hcb *np)
{
	u32 sym_rd, sym_wr, sym_bk, host_rd, host_wr, pc, dstat;
	int i, err;

	err = sym_regtest(np);
	if (err)
		return err;
restart_test:
	/*
	 *  Enable Master Parity Checking as we intend 
	 *  to enable it for normal operations.
	 */
	OUTB(np, nc_ctest4, (np->rv_ctest4 & MPEE));
	/*
	 *  init
	 */
	pc  = SCRIPTZ_BA(np, snooptest);
	host_wr = 1;
	sym_wr  = 2;
	/*
	 *  Set memory and register.
	 */
	np->scratch = cpu_to_scr(host_wr);
	OUTL(np, nc_temp, sym_wr);
	/*
	 *  Start script (exchange values)
	 */
	OUTL(np, nc_dsa, np->hcb_ba);
	OUTL_DSP(np, pc);
	/*
	 *  Wait 'til done (with timeout)
	 */
	for (i=0; i<SYM_SNOOP_TIMEOUT; i++)
		if (INB(np, nc_istat) & (INTF|SIP|DIP))
			break;
	if (i>=SYM_SNOOP_TIMEOUT) {
		printf ("CACHE TEST FAILED: timeout.\n");
		return (0x20);
	}
	/*
	 *  Check for fatal DMA errors.
	 */
	dstat = INB(np, nc_dstat);
#if 1	/* Band aiding for broken hardwares that fail PCI parity */
	if ((dstat & MDPE) && (np->rv_ctest4 & MPEE)) {
		printf ("%s: PCI DATA PARITY ERROR DETECTED - "
			"DISABLING MASTER DATA PARITY CHECKING.\n",
			sym_name(np));
		np->rv_ctest4 &= ~MPEE;
		goto restart_test;
	}
#endif
	if (dstat & (MDPE|BF|IID)) {
		printf ("CACHE TEST FAILED: DMA error (dstat=0x%02x).", dstat);
		return (0x80);
	}
	/*
	 *  Save termination position.
	 */
	pc = INL(np, nc_dsp);
	/*
	 *  Read memory and register.
	 */
	host_rd = scr_to_cpu(np->scratch);
	sym_rd  = INL(np, nc_scratcha);
	sym_bk  = INL(np, nc_temp);
	/*
	 *  Check termination position.
	 */
	if (pc != SCRIPTZ_BA(np, snoopend)+8) {
		printf ("CACHE TEST FAILED: script execution failed.\n");
		printf ("start=%08lx, pc=%08lx, end=%08lx\n", 
			(u_long) SCRIPTZ_BA(np, snooptest), (u_long) pc,
			(u_long) SCRIPTZ_BA(np, snoopend) +8);
		return (0x40);
	}
	/*
	 *  Show results.
	 */
	if (host_wr != sym_rd) {
		printf ("CACHE TEST FAILED: host wrote %d, chip read %d.\n",
			(int) host_wr, (int) sym_rd);
		err |= 1;
	}
	if (host_rd != sym_wr) {
		printf ("CACHE TEST FAILED: chip wrote %d, host read %d.\n",
			(int) sym_wr, (int) host_rd);
		err |= 2;
	}
	if (sym_bk != sym_wr) {
		printf ("CACHE TEST FAILED: chip wrote %d, read back %d.\n",
			(int) sym_wr, (int) sym_bk);
		err |= 4;
	}

	return err;
}

/*
 *  log message for real hard errors
 *
 *  sym0 targ 0?: ERROR (ds:si) (so-si-sd) (sx/s3/s4) @ name (dsp:dbc).
 *  	      reg: r0 r1 r2 r3 r4 r5 r6 ..... rf.
 *
 *  exception register:
 *  	ds:	dstat
 *  	si:	sist
 *
 *  SCSI bus lines:
 *  	so:	control lines as driven by chip.
 *  	si:	control lines as seen by chip.
 *  	sd:	scsi data lines as seen by chip.
 *
 *  wide/fastmode:
 *  	sx:	sxfer  (see the manual)
 *  	s3:	scntl3 (see the manual)
 *  	s4:	scntl4 (see the manual)
 *
 *  current script command:
 *  	dsp:	script address (relative to start of script).
 *  	dbc:	first word of script command.
 *
 *  First 24 register of the chip:
 *  	r0..rf
 */
static void sym_log_hard_error(struct Scsi_Host *shost, u_short sist, u_char dstat)
{
	struct sym_hcb *np = sym_get_hcb(shost);
	u32	dsp;
	int	script_ofs;
	int	script_size;
	char	*script_name;
	u_char	*script_base;
	int	i;

	dsp	= INL(np, nc_dsp);

	if	(dsp > np->scripta_ba &&
		 dsp <= np->scripta_ba + np->scripta_sz) {
		script_ofs	= dsp - np->scripta_ba;
		script_size	= np->scripta_sz;
		script_base	= (u_char *) np->scripta0;
		script_name	= "scripta";
	}
	else if (np->scriptb_ba < dsp && 
		 dsp <= np->scriptb_ba + np->scriptb_sz) {
		script_ofs	= dsp - np->scriptb_ba;
		script_size	= np->scriptb_sz;
		script_base	= (u_char *) np->scriptb0;
		script_name	= "scriptb";
	} else {
		script_ofs	= dsp;
		script_size	= 0;
		script_base	= NULL;
		script_name	= "mem";
	}

	printf ("%s:%d: ERROR (%x:%x) (%x-%x-%x) (%x/%x/%x) @ (%s %x:%08x).\n",
		sym_name(np), (unsigned)INB(np, nc_sdid)&0x0f, dstat, sist,
		(unsigned)INB(np, nc_socl), (unsigned)INB(np, nc_sbcl),
		(unsigned)INB(np, nc_sbdl), (unsigned)INB(np, nc_sxfer),
		(unsigned)INB(np, nc_scntl3),
		(np->features & FE_C10) ?  (unsigned)INB(np, nc_scntl4) : 0,
		script_name, script_ofs,   (unsigned)INL(np, nc_dbc));

	if (((script_ofs & 3) == 0) &&
	    (unsigned)script_ofs < script_size) {
		printf ("%s: script cmd = %08x\n", sym_name(np),
			scr_to_cpu((int) *(u32 *)(script_base + script_ofs)));
	}

	printf("%s: regdump:", sym_name(np));
	for (i = 0; i < 24; i++)
		printf(" %02x", (unsigned)INB_OFF(np, i));
	printf(".\n");

	/*
	 *  PCI BUS error.
	 */
	if (dstat & (MDPE|BF))
		sym_log_bus_error(shost);
}

void sym_dump_registers(struct Scsi_Host *shost)
{
	struct sym_hcb *np = sym_get_hcb(shost);
	u_short sist;
	u_char dstat;

	sist = INW(np, nc_sist);
	dstat = INB(np, nc_dstat);
	sym_log_hard_error(shost, sist, dstat);
}

static struct sym_chip sym_dev_table[] = {
 {PCI_DEVICE_ID_NCR_53C810, 0x0f, "810", 4, 8, 4, 64,
 FE_ERL}
 ,
#ifdef SYM_DEBUG_GENERIC_SUPPORT
 {PCI_DEVICE_ID_NCR_53C810, 0xff, "810a", 4,  8, 4, 1,
 FE_BOF}
 ,
#else
 {PCI_DEVICE_ID_NCR_53C810, 0xff, "810a", 4,  8, 4, 1,
 FE_CACHE_SET|FE_LDSTR|FE_PFEN|FE_BOF}
 ,
#endif
 {PCI_DEVICE_ID_NCR_53C815, 0xff, "815", 4,  8, 4, 64,
 FE_BOF|FE_ERL}
 ,
 {PCI_DEVICE_ID_NCR_53C825, 0x0f, "825", 6,  8, 4, 64,
 FE_WIDE|FE_BOF|FE_ERL|FE_DIFF}
 ,
 {PCI_DEVICE_ID_NCR_53C825, 0xff, "825a", 6,  8, 4, 2,
 FE_WIDE|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM|FE_DIFF}
 ,
 {PCI_DEVICE_ID_NCR_53C860, 0xff, "860", 4,  8, 5, 1,
 FE_ULTRA|FE_CACHE_SET|FE_BOF|FE_LDSTR|FE_PFEN}
 ,
 {PCI_DEVICE_ID_NCR_53C875, 0x01, "875", 6, 16, 5, 2,
 FE_WIDE|FE_ULTRA|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_DIFF|FE_VARCLK}
 ,
 {PCI_DEVICE_ID_NCR_53C875, 0xff, "875", 6, 16, 5, 2,
 FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_DIFF|FE_VARCLK}
 ,
 {PCI_DEVICE_ID_NCR_53C875J, 0xff, "875J", 6, 16, 5, 2,
 FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_DIFF|FE_VARCLK}
 ,
 {PCI_DEVICE_ID_NCR_53C885, 0xff, "885", 6, 16, 5, 2,
 FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_DIFF|FE_VARCLK}
 ,
#ifdef SYM_DEBUG_GENERIC_SUPPORT
 {PCI_DEVICE_ID_NCR_53C895, 0xff, "895", 6, 31, 7, 2,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|
 FE_RAM|FE_LCKFRQ}
 ,
#else
 {PCI_DEVICE_ID_NCR_53C895, 0xff, "895", 6, 31, 7, 2,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_LCKFRQ}
 ,
#endif
 {PCI_DEVICE_ID_NCR_53C896, 0xff, "896", 6, 31, 7, 4,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_LCKFRQ}
 ,
 {PCI_DEVICE_ID_LSI_53C895A, 0xff, "895a", 6, 31, 7, 4,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_RAM8K|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_LCKFRQ}
 ,
 {PCI_DEVICE_ID_LSI_53C875A, 0xff, "875a", 6, 31, 7, 4,
 FE_WIDE|FE_ULTRA|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_LCKFRQ}
 ,
 {PCI_DEVICE_ID_LSI_53C1010_33, 0x00, "1010-33", 6, 31, 7, 8,
 FE_WIDE|FE_ULTRA3|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFBC|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_CRC|
 FE_C10}
 ,
 {PCI_DEVICE_ID_LSI_53C1010_33, 0xff, "1010-33", 6, 31, 7, 8,
 FE_WIDE|FE_ULTRA3|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFBC|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_CRC|
 FE_C10|FE_U3EN}
 ,
 {PCI_DEVICE_ID_LSI_53C1010_66, 0xff, "1010-66", 6, 31, 7, 8,
 FE_WIDE|FE_ULTRA3|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFBC|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_66MHZ|FE_CRC|
 FE_C10|FE_U3EN}
 ,
 {PCI_DEVICE_ID_LSI_53C1510, 0xff, "1510d", 6, 31, 7, 4,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
 FE_RAM|FE_IO256|FE_LEDC}
};

#define sym_num_devs (ARRAY_SIZE(sym_dev_table))

/*
 *  Look up the chip table.
 *
 *  Return a pointer to the chip entry if found, 
 *  zero otherwise.
 */
struct sym_chip *
sym_lookup_chip_table (u_short device_id, u_char revision)
{
	struct	sym_chip *chip;
	int	i;

	for (i = 0; i < sym_num_devs; i++) {
		chip = &sym_dev_table[i];
		if (device_id != chip->device_id)
			continue;
		if (revision > chip->revision_id)
			continue;
		return chip;
	}

	return NULL;
}

#if SYM_CONF_DMA_ADDRESSING_MODE == 2
/*
 *  Lookup the 64 bit DMA segments map.
 *  This is only used if the direct mapping 
 *  has been unsuccessful.
 */
int sym_lookup_dmap(struct sym_hcb *np, u32 h, int s)
{
	int i;

	if (!use_dac(np))
		goto weird;

	/* Look up existing mappings */
	for (i = SYM_DMAP_SIZE-1; i > 0; i--) {
		if (h == np->dmap_bah[i])
			return i;
	}
	/* If direct mapping is free, get it */
	if (!np->dmap_bah[s])
		goto new;
	/* Collision -> lookup free mappings */
	for (s = SYM_DMAP_SIZE-1; s > 0; s--) {
		if (!np->dmap_bah[s])
			goto new;
	}
weird:
	panic("sym: ran out of 64 bit DMA segment registers");
	return -1;
new:
	np->dmap_bah[s] = h;
	np->dmap_dirty = 1;
	return s;
}

/*
 *  Update IO registers scratch C..R so they will be 
 *  in sync. with queued CCB expectations.
 */
static void sym_update_dmap_regs(struct sym_hcb *np)
{
	int o, i;

	if (!np->dmap_dirty)
		return;
	o = offsetof(struct sym_reg, nc_scrx[0]);
	for (i = 0; i < SYM_DMAP_SIZE; i++) {
		OUTL_OFF(np, o, np->dmap_bah[i]);
		o += 4;
	}
	np->dmap_dirty = 0;
}
#endif

/* Enforce all the fiddly SPI rules and the chip limitations */
static void sym_check_goals(struct sym_hcb *np, struct scsi_target *starget,
		struct sym_trans *goal)
{
	if (!spi_support_wide(starget))
		goal->width = 0;

	if (!spi_support_sync(starget)) {
		goal->iu = 0;
		goal->dt = 0;
		goal->qas = 0;
		goal->offset = 0;
		return;
	}

	if (spi_support_dt(starget)) {
		if (spi_support_dt_only(starget))
			goal->dt = 1;

		if (goal->offset == 0)
			goal->dt = 0;
	} else {
		goal->dt = 0;
	}

	/* Some targets fail to properly negotiate DT in SE mode */
	if ((np->scsi_mode != SMODE_LVD) || !(np->features & FE_U3EN))
		goal->dt = 0;

	if (goal->dt) {
		/* all DT transfers must be wide */
		goal->width = 1;
		if (goal->offset > np->maxoffs_dt)
			goal->offset = np->maxoffs_dt;
		if (goal->period < np->minsync_dt)
			goal->period = np->minsync_dt;
		if (goal->period > np->maxsync_dt)
			goal->period = np->maxsync_dt;
	} else {
		goal->iu = goal->qas = 0;
		if (goal->offset > np->maxoffs)
			goal->offset = np->maxoffs;
		if (goal->period < np->minsync)
			goal->period = np->minsync;
		if (goal->period > np->maxsync)
			goal->period = np->maxsync;
	}
}

/*
 *  Prepare the next negotiation message if needed.
 *
 *  Fill in the part of message buffer that contains the 
 *  negotiation and the nego_status field of the CCB.
 *  Returns the size of the message in bytes.
 */
static int sym_prepare_nego(struct sym_hcb *np, struct sym_ccb *cp, u_char *msgptr)
{
	struct sym_tcb *tp = &np->target[cp->target];
	struct scsi_target *starget = tp->starget;
	struct sym_trans *goal = &tp->tgoal;
	int msglen = 0;
	int nego;

	sym_check_goals(np, starget, goal);

	/*
	 * Many devices implement PPR in a buggy way, so only use it if we
	 * really want to.
	 */
	if (goal->renego == NS_PPR || (goal->offset &&
	    (goal->iu || goal->dt || goal->qas || (goal->period < 0xa)))) {
		nego = NS_PPR;
	} else if (goal->renego == NS_WIDE || goal->width) {
		nego = NS_WIDE;
	} else if (goal->renego == NS_SYNC || goal->offset) {
		nego = NS_SYNC;
	} else {
		goal->check_nego = 0;
		nego = 0;
	}

	switch (nego) {
	case NS_SYNC:
		msglen += spi_populate_sync_msg(msgptr + msglen, goal->period,
				goal->offset);
		break;
	case NS_WIDE:
		msglen += spi_populate_width_msg(msgptr + msglen, goal->width);
		break;
	case NS_PPR:
		msglen += spi_populate_ppr_msg(msgptr + msglen, goal->period,
				goal->offset, goal->width,
				(goal->iu ? PPR_OPT_IU : 0) |
					(goal->dt ? PPR_OPT_DT : 0) |
					(goal->qas ? PPR_OPT_QAS : 0));
		break;
	}

	cp->nego_status = nego;

	if (nego) {
		tp->nego_cp = cp; /* Keep track a nego will be performed */
		if (DEBUG_FLAGS & DEBUG_NEGO) {
			sym_print_nego_msg(np, cp->target, 
					  nego == NS_SYNC ? "sync msgout" :
					  nego == NS_WIDE ? "wide msgout" :
					  "ppr msgout", msgptr);
		}
	}

	return msglen;
}

/*
 *  Insert a job into the start queue.
 */
void sym_put_start_queue(struct sym_hcb *np, struct sym_ccb *cp)
{
	u_short	qidx;

#ifdef SYM_CONF_IARB_SUPPORT
	/*
	 *  If the previously queued CCB is not yet done, 
	 *  set the IARB hint. The SCRIPTS will go with IARB 
	 *  for this job when starting the previous one.
	 *  We leave devices a chance to win arbitration by 
	 *  not using more than 'iarb_max' consecutive 
	 *  immediate arbitrations.
	 */
	if (np->last_cp && np->iarb_count < np->iarb_max) {
		np->last_cp->host_flags |= HF_HINT_IARB;
		++np->iarb_count;
	}
	else
		np->iarb_count = 0;
	np->last_cp = cp;
#endif

#if   SYM_CONF_DMA_ADDRESSING_MODE == 2
	/*
	 *  Make SCRIPTS aware of the 64 bit DMA 
	 *  segment registers not being up-to-date.
	 */
	if (np->dmap_dirty)
		cp->host_xflags |= HX_DMAP_DIRTY;
#endif

	/*
	 *  Insert first the idle task and then our job.
	 *  The MBs should ensure proper ordering.
	 */
	qidx = np->squeueput + 2;
	if (qidx >= MAX_QUEUE*2) qidx = 0;

	np->squeue [qidx]	   = cpu_to_scr(np->idletask_ba);
	MEMORY_WRITE_BARRIER();
	np->squeue [np->squeueput] = cpu_to_scr(cp->ccb_ba);

	np->squeueput = qidx;

	if (DEBUG_FLAGS & DEBUG_QUEUE)
		scmd_printk(KERN_DEBUG, cp->cmd, "queuepos=%d\n",
							np->squeueput);

	/*
	 *  Script processor may be waiting for reselect.
	 *  Wake it up.
	 */
	MEMORY_WRITE_BARRIER();
	OUTB(np, nc_istat, SIGP|np->istat_sem);
}

#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
/*
 *  Start next ready-to-start CCBs.
 */
void sym_start_next_ccbs(struct sym_hcb *np, struct sym_lcb *lp, int maxn)
{
	SYM_QUEHEAD *qp;
	struct sym_ccb *cp;

	/* 
	 *  Paranoia, as usual. :-)
	 */
	assert(!lp->started_tags || !lp->started_no_tag);

	/*
	 *  Try to start as many commands as asked by caller.
	 *  Prevent from having both tagged and untagged 
	 *  commands queued to the device at the same time.
	 */
	while (maxn--) {
		qp = sym_remque_head(&lp->waiting_ccbq);
		if (!qp)
			break;
		cp = sym_que_entry(qp, struct sym_ccb, link2_ccbq);
		if (cp->tag != NO_TAG) {
			if (lp->started_no_tag ||
			    lp->started_tags >= lp->started_max) {
				sym_insque_head(qp, &lp->waiting_ccbq);
				break;
			}
			lp->itlq_tbl[cp->tag] = cpu_to_scr(cp->ccb_ba);
			lp->head.resel_sa =
				cpu_to_scr(SCRIPTA_BA(np, resel_tag));
			++lp->started_tags;
		} else {
			if (lp->started_no_tag || lp->started_tags) {
				sym_insque_head(qp, &lp->waiting_ccbq);
				break;
			}
			lp->head.itl_task_sa = cpu_to_scr(cp->ccb_ba);
			lp->head.resel_sa =
			      cpu_to_scr(SCRIPTA_BA(np, resel_no_tag));
			++lp->started_no_tag;
		}
		cp->started = 1;
		sym_insque_tail(qp, &lp->started_ccbq);
		sym_put_start_queue(np, cp);
	}
}
#endif /* SYM_OPT_HANDLE_DEVICE_QUEUEING */

/*
 *  The chip may have completed jobs. Look at the DONE QUEUE.
 *
 *  On paper, memory read barriers may be needed here to 
 *  prevent out of order LOADs by the CPU from having 
 *  prefetched stale data prior to DMA having occurred.
 */
static int sym_wakeup_done (struct sym_hcb *np)
{
	struct sym_ccb *cp;
	int i, n;
	u32 dsa;

	n = 0;
	i = np->dqueueget;

	/* MEMORY_READ_BARRIER(); */
	while (1) {
		dsa = scr_to_cpu(np->dqueue[i]);
		if (!dsa)
			break;
		np->dqueue[i] = 0;
		if ((i = i+2) >= MAX_QUEUE*2)
			i = 0;

		cp = sym_ccb_from_dsa(np, dsa);
		if (cp) {
			MEMORY_READ_BARRIER();
			sym_complete_ok (np, cp);
			++n;
		}
		else
			printf ("%s: bad DSA (%x) in done queue.\n",
				sym_name(np), (u_int) dsa);
	}
	np->dqueueget = i;

	return n;
}

/*
 *  Complete all CCBs queued to the COMP queue.
 *
 *  These CCBs are assumed:
 *  - Not to be referenced either by devices or 
 *    SCRIPTS-related queues and datas.
 *  - To have to be completed with an error condition 
 *    or requeued.
 *
 *  The device queue freeze count is incremented 
 *  for each CCB that does not prevent this.
 *  This function is called when all CCBs involved 
 *  in error handling/recovery have been reaped.
 */
static void sym_flush_comp_queue(struct sym_hcb *np, int cam_status)
{
	SYM_QUEHEAD *qp;
	struct sym_ccb *cp;

	while ((qp = sym_remque_head(&np->comp_ccbq)) != NULL) {
		struct scsi_cmnd *cmd;
		cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
		sym_insque_tail(&cp->link_ccbq, &np->busy_ccbq);
		/* Leave quiet CCBs waiting for resources */
		if (cp->host_status == HS_WAIT)
			continue;
		cmd = cp->cmd;
		if (cam_status)
			sym_set_cam_status(cmd, cam_status);
#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
		if (sym_get_cam_status(cmd) == DID_SOFT_ERROR) {
			struct sym_tcb *tp = &np->target[cp->target];
			struct sym_lcb *lp = sym_lp(tp, cp->lun);
			if (lp) {
				sym_remque(&cp->link2_ccbq);
				sym_insque_tail(&cp->link2_ccbq,
				                &lp->waiting_ccbq);
				if (cp->started) {
					if (cp->tag != NO_TAG)
						--lp->started_tags;
					else
						--lp->started_no_tag;
				}
			}
			cp->started = 0;
			continue;
		}
#endif
		sym_free_ccb(np, cp);
		sym_xpt_done(np, cmd);
	}
}

/*
 *  Complete all active CCBs with error.
 *  Used on CHIP/SCSI RESET.
 */
static void sym_flush_busy_queue (struct sym_hcb *np, int cam_status)
{
	/*
	 *  Move all active CCBs to the COMP queue 
	 *  and flush this queue.
	 */
	sym_que_splice(&np->busy_ccbq, &np->comp_ccbq);
	sym_que_init(&np->busy_ccbq);
	sym_flush_comp_queue(np, cam_status);
}

/*
 *  Start chip.
 *
 *  'reason' means:
 *     0: initialisation.
 *     1: SCSI BUS RESET delivered or received.
 *     2: SCSI BUS MODE changed.
 */
void sym_start_up(struct Scsi_Host *shost, int reason)
{
	struct sym_data *sym_data = shost_priv(shost);
	struct pci_dev *pdev = sym_data->pdev;
	struct sym_hcb *np = sym_data->ncb;
 	int	i;
	u32	phys;

 	/*
	 *  Reset chip if asked, otherwise just clear fifos.
 	 */
	if (reason == 1)
		sym_soft_reset(np);
	else {
		OUTB(np, nc_stest3, TE|CSF);
		OUTONB(np, nc_ctest3, CLF);
	}
 
	/*
	 *  Clear Start Queue
	 */
	phys = np->squeue_ba;
	for (i = 0; i < MAX_QUEUE*2; i += 2) {
		np->squeue[i]   = cpu_to_scr(np->idletask_ba);
		np->squeue[i+1] = cpu_to_scr(phys + (i+2)*4);
	}
	np->squeue[MAX_QUEUE*2-1] = cpu_to_scr(phys);

	/*
	 *  Start at first entry.
	 */
	np->squeueput = 0;

	/*
	 *  Clear Done Queue
	 */
	phys = np->dqueue_ba;
	for (i = 0; i < MAX_QUEUE*2; i += 2) {
		np->dqueue[i]   = 0;
		np->dqueue[i+1] = cpu_to_scr(phys + (i+2)*4);
	}
	np->dqueue[MAX_QUEUE*2-1] = cpu_to_scr(phys);

	/*
	 *  Start at first entry.
	 */
	np->dqueueget = 0;

	/*
	 *  Install patches in scripts.
	 *  This also let point to first position the start 
	 *  and done queue pointers used from SCRIPTS.
	 */
	np->fw_patch(shost);

	/*
	 *  Wakeup all pending jobs.
	 */
	sym_flush_busy_queue(np, DID_RESET);

	/*
	 *  Init chip.
	 */
	OUTB(np, nc_istat,  0x00);			/*  Remove Reset, abort */
	INB(np, nc_mbox1);
	udelay(2000); /* The 895 needs time for the bus mode to settle */

	OUTB(np, nc_scntl0, np->rv_scntl0 | 0xc0);
					/*  full arb., ena parity, par->ATN  */
	OUTB(np, nc_scntl1, 0x00);		/*  odd parity, and remove CRST!! */

	sym_selectclock(np, np->rv_scntl3);	/* Select SCSI clock */

	OUTB(np, nc_scid  , RRE|np->myaddr);	/* Adapter SCSI address */
	OUTW(np, nc_respid, 1ul<<np->myaddr);	/* Id to respond to */
	OUTB(np, nc_istat , SIGP	);		/*  Signal Process */
	OUTB(np, nc_dmode , np->rv_dmode);		/* Burst length, dma mode */
	OUTB(np, nc_ctest5, np->rv_ctest5);	/* Large fifo + large burst */

	OUTB(np, nc_dcntl , NOCOM|np->rv_dcntl);	/* Protect SFBR */
	OUTB(np, nc_ctest3, np->rv_ctest3);	/* Write and invalidate */
	OUTB(np, nc_ctest4, np->rv_ctest4);	/* Master parity checking */

	/* Extended Sreq/Sack filtering not supported on the C10 */
	if (np->features & FE_C10)
		OUTB(np, nc_stest2, np->rv_stest2);
	else
		OUTB(np, nc_stest2, EXT|np->rv_stest2);

	OUTB(np, nc_stest3, TE);			/* TolerANT enable */
	OUTB(np, nc_stime0, 0x0c);			/* HTH disabled  STO 0.25 sec */

	/*
	 *  For now, disable AIP generation on C1010-66.
	 */
	if (pdev->device == PCI_DEVICE_ID_LSI_53C1010_66)
		OUTB(np, nc_aipcntl1, DISAIP);

	/*
	 *  C10101 rev. 0 errata.
	 *  Errant SGE's when in narrow. Write bits 4 & 5 of
	 *  STEST1 register to disable SGE. We probably should do 
	 *  that from SCRIPTS for each selection/reselection, but 
	 *  I just don't want. :)
	 */
	if (pdev->device == PCI_DEVICE_ID_LSI_53C1010_33 &&
	    pdev->revision < 1)
		OUTB(np, nc_stest1, INB(np, nc_stest1) | 0x30);

	/*
	 *  DEL 441 - 53C876 Rev 5 - Part Number 609-0392787/2788 - ITEM 2.
	 *  Disable overlapped arbitration for some dual function devices, 
	 *  regardless revision id (kind of post-chip-design feature. ;-))
	 */
	if (pdev->device == PCI_DEVICE_ID_NCR_53C875)
		OUTB(np, nc_ctest0, (1<<5));
	else if (pdev->device == PCI_DEVICE_ID_NCR_53C896)
		np->rv_ccntl0 |= DPR;

	/*
	 *  Write CCNTL0/CCNTL1 for chips capable of 64 bit addressing 
	 *  and/or hardware phase mismatch, since only such chips 
	 *  seem to support those IO registers.
	 */
	if (np->features & (FE_DAC|FE_NOPM)) {
		OUTB(np, nc_ccntl0, np->rv_ccntl0);
		OUTB(np, nc_ccntl1, np->rv_ccntl1);
	}

#if	SYM_CONF_DMA_ADDRESSING_MODE == 2
	/*
	 *  Set up scratch C and DRS IO registers to map the 32 bit 
	 *  DMA address range our data structures are located in.
	 */
	if (use_dac(np)) {
		np->dmap_bah[0] = 0;	/* ??? */
		OUTL(np, nc_scrx[0], np->dmap_bah[0]);
		OUTL(np, nc_drs, np->dmap_bah[0]);
	}
#endif

	/*
	 *  If phase mismatch handled by scripts (895A/896/1010),
	 *  set PM jump addresses.
	 */
	if (np->features & FE_NOPM) {
		OUTL(np, nc_pmjad1, SCRIPTB_BA(np, pm_handle));
		OUTL(np, nc_pmjad2, SCRIPTB_BA(np, pm_handle));
	}

	/*
	 *    Enable GPIO0 pin for writing if LED support from SCRIPTS.
	 *    Also set GPIO5 and clear GPIO6 if hardware LED control.
	 */
	if (np->features & FE_LED0)
		OUTB(np, nc_gpcntl, INB(np, nc_gpcntl) & ~0x01);
	else if (np->features & FE_LEDC)
		OUTB(np, nc_gpcntl, (INB(np, nc_gpcntl) & ~0x41) | 0x20);

	/*
	 *      enable ints
	 */
	OUTW(np, nc_sien , STO|HTH|MA|SGE|UDC|RST|PAR);
	OUTB(np, nc_dien , MDPE|BF|SSI|SIR|IID);

	/*
	 *  For 895/6 enable SBMC interrupt and save current SCSI bus mode.
	 *  Try to eat the spurious SBMC interrupt that may occur when 
	 *  we reset the chip but not the SCSI BUS (at initialization).
	 */
	if (np->features & (FE_ULTRA2|FE_ULTRA3)) {
		OUTONW(np, nc_sien, SBMC);
		if (reason == 0) {
			INB(np, nc_mbox1);
			mdelay(100);
			INW(np, nc_sist);
		}
		np->scsi_mode = INB(np, nc_stest4) & SMODE;
	}

	/*
	 *  Fill in target structure.
	 *  Reinitialize usrsync.
	 *  Reinitialize usrwide.
	 *  Prepare sync negotiation according to actual SCSI bus mode.
	 */
	for (i=0;i<SYM_CONF_MAX_TARGET;i++) {
		struct sym_tcb *tp = &np->target[i];

		tp->to_reset  = 0;
		tp->head.sval = 0;
		tp->head.wval = np->rv_scntl3;
		tp->head.uval = 0;
		if (tp->lun0p)
			tp->lun0p->to_clear = 0;
		if (tp->lunmp) {
			int ln;

			for (ln = 1; ln < SYM_CONF_MAX_LUN; ln++)
				if (tp->lunmp[ln])
					tp->lunmp[ln]->to_clear = 0;
		}
	}

	/*
	 *  Download SCSI SCRIPTS to on-chip RAM if present,
	 *  and start script processor.
	 *  We do the download preferently from the CPU.
	 *  For platforms that may not support PCI memory mapping,
	 *  we use simple SCRIPTS that performs MEMORY MOVEs.
	 */
	phys = SCRIPTA_BA(np, init);
	if (np->ram_ba) {
		if (sym_verbose >= 2)
			printf("%s: Downloading SCSI SCRIPTS.\n", sym_name(np));
		memcpy_toio(np->s.ramaddr, np->scripta0, np->scripta_sz);
		if (np->features & FE_RAM8K) {
			memcpy_toio(np->s.ramaddr + 4096, np->scriptb0, np->scriptb_sz);
			phys = scr_to_cpu(np->scr_ram_seg);
			OUTL(np, nc_mmws, phys);
			OUTL(np, nc_mmrs, phys);
			OUTL(np, nc_sfs,  phys);
			phys = SCRIPTB_BA(np, start64);
		}
	}

	np->istat_sem = 0;

	OUTL(np, nc_dsa, np->hcb_ba);
	OUTL_DSP(np, phys);

	/*
	 *  Notify the XPT about the RESET condition.
	 */
	if (reason != 0)
		sym_xpt_async_bus_reset(np);
}

/*
 *  Switch trans mode for current job and its target.
 */
static void sym_settrans(struct sym_hcb *np, int target, u_char opts, u_char ofs,
			 u_char per, u_char wide, u_char div, u_char fak)
{
	SYM_QUEHEAD *qp;
	u_char sval, wval, uval;
	struct sym_tcb *tp = &np->target[target];

	assert(target == (INB(np, nc_sdid) & 0x0f));

	sval = tp->head.sval;
	wval = tp->head.wval;
	uval = tp->head.uval;

#if 0
	printf("XXXX sval=%x wval=%x uval=%x (%x)\n", 
		sval, wval, uval, np->rv_scntl3);
#endif
	/*
	 *  Set the offset.
	 */
	if (!(np->features & FE_C10))
		sval = (sval & ~0x1f) | ofs;
	else
		sval = (sval & ~0x3f) | ofs;

	/*
	 *  Set the sync divisor and extra clock factor.
	 */
	if (ofs != 0) {
		wval = (wval & ~0x70) | ((div+1) << 4);
		if (!(np->features & FE_C10))
			sval = (sval & ~0xe0) | (fak << 5);
		else {
			uval = uval & ~(XCLKH_ST|XCLKH_DT|XCLKS_ST|XCLKS_DT);
			if (fak >= 1) uval |= (XCLKH_ST|XCLKH_DT);
			if (fak >= 2) uval |= (XCLKS_ST|XCLKS_DT);
		}
	}

	/*
	 *  Set the bus width.
	 */
	wval = wval & ~EWS;
	if (wide != 0)
		wval |= EWS;

	/*
	 *  Set misc. ultra enable bits.
	 */
	if (np->features & FE_C10) {
		uval = uval & ~(U3EN|AIPCKEN);
		if (opts)	{
			assert(np->features & FE_U3EN);
			uval |= U3EN;
		}
	} else {
		wval = wval & ~ULTRA;
		if (per <= 12)	wval |= ULTRA;
	}

	/*
	 *   Stop there if sync parameters are unchanged.
	 */
	if (tp->head.sval == sval && 
	    tp->head.wval == wval &&
	    tp->head.uval == uval)
		return;
	tp->head.sval = sval;
	tp->head.wval = wval;
	tp->head.uval = uval;

	/*
	 *  Disable extended Sreq/Sack filtering if per < 50.
	 *  Not supported on the C1010.
	 */
	if (per < 50 && !(np->features & FE_C10))
		OUTOFFB(np, nc_stest2, EXT);

	/*
	 *  set actual value and sync_status
	 */
	OUTB(np, nc_sxfer,  tp->head.sval);
	OUTB(np, nc_scntl3, tp->head.wval);

	if (np->features & FE_C10) {
		OUTB(np, nc_scntl4, tp->head.uval);
	}

	/*
	 *  patch ALL busy ccbs of this target.
	 */
	FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
		struct sym_ccb *cp;
		cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
		if (cp->target != target)
			continue;
		cp->phys.select.sel_scntl3 = tp->head.wval;
		cp->phys.select.sel_sxfer  = tp->head.sval;
		if (np->features & FE_C10) {
			cp->phys.select.sel_scntl4 = tp->head.uval;
		}
	}
}

static void sym_announce_transfer_rate(struct sym_tcb *tp)
{
	struct scsi_target *starget = tp->starget;

	if (tp->tprint.period != spi_period(starget) ||
	    tp->tprint.offset != spi_offset(starget) ||
	    tp->tprint.width != spi_width(starget) ||
	    tp->tprint.iu != spi_iu(starget) ||
	    tp->tprint.dt != spi_dt(starget) ||
	    tp->tprint.qas != spi_qas(starget) ||
	    !tp->tprint.check_nego) {
		tp->tprint.period = spi_period(starget);
		tp->tprint.offset = spi_offset(starget);
		tp->tprint.width = spi_width(starget);
		tp->tprint.iu = spi_iu(starget);
		tp->tprint.dt = spi_dt(starget);
		tp->tprint.qas = spi_qas(starget);
		tp->tprint.check_nego = 1;

		spi_display_xfer_agreement(starget);
	}
}

/*
 *  We received a WDTR.
 *  Let everything be aware of the changes.
 */
static void sym_setwide(struct sym_hcb *np, int target, u_char wide)
{
	struct sym_tcb *tp = &np->target[target];
	struct scsi_target *starget = tp->starget;

	sym_settrans(np, target, 0, 0, 0, wide, 0, 0);

	if (wide)
		tp->tgoal.renego = NS_WIDE;
	else
		tp->tgoal.renego = 0;
	tp->tgoal.check_nego = 0;
	tp->tgoal.width = wide;
	spi_offset(starget) = 0;
	spi_period(starget) = 0;
	spi_width(starget) = wide;
	spi_iu(starget) = 0;
	spi_dt(starget) = 0;
	spi_qas(starget) = 0;

	if (sym_verbose >= 3)
		sym_announce_transfer_rate(tp);
}

/*
 *  We received a SDTR.
 *  Let everything be aware of the changes.
 */
static void
sym_setsync(struct sym_hcb *np, int target,
            u_char ofs, u_char per, u_char div, u_char fak)
{
	struct sym_tcb *tp = &np->target[target];
	struct scsi_target *starget = tp->starget;
	u_char wide = (tp->head.wval & EWS) ? BUS_16_BIT : BUS_8_BIT;

	sym_settrans(np, target, 0, ofs, per, wide, div, fak);

	if (wide)
		tp->tgoal.renego = NS_WIDE;
	else if (ofs)
		tp->tgoal.renego = NS_SYNC;
	else
		tp->tgoal.renego = 0;
	spi_period(starget) = per;
	spi_offset(starget) = ofs;
	spi_iu(starget) = spi_dt(starget) = spi_qas(starget) = 0;

	if (!tp->tgoal.dt && !tp->tgoal.iu && !tp->tgoal.qas) {
		tp->tgoal.period = per;
		tp->tgoal.offset = ofs;
		tp->tgoal.check_nego = 0;
	}

	sym_announce_transfer_rate(tp);
}

/*
 *  We received a PPR.
 *  Let everything be aware of the changes.
 */
static void 
sym_setpprot(struct sym_hcb *np, int target, u_char opts, u_char ofs,
             u_char per, u_char wide, u_char div, u_char fak)
{
	struct sym_tcb *tp = &np->target[target];
	struct scsi_target *starget = tp->starget;

	sym_settrans(np, target, opts, ofs, per, wide, div, fak);

	if (wide || ofs)
		tp->tgoal.renego = NS_PPR;
	else
		tp->tgoal.renego = 0;
	spi_width(starget) = tp->tgoal.width = wide;
	spi_period(starget) = tp->tgoal.period = per;
	spi_offset(starget) = tp->tgoal.offset = ofs;
	spi_iu(starget) = tp->tgoal.iu = !!(opts & PPR_OPT_IU);
	spi_dt(starget) = tp->tgoal.dt = !!(opts & PPR_OPT_DT);
	spi_qas(starget) = tp->tgoal.qas = !!(opts & PPR_OPT_QAS);
	tp->tgoal.check_nego = 0;

	sym_announce_transfer_rate(tp);
}

/*
 *  generic recovery from scsi interrupt
 *
 *  The doc says that when the chip gets an SCSI interrupt,
 *  it tries to stop in an orderly fashion, by completing 
 *  an instruction fetch that had started or by flushing 
 *  the DMA fifo for a write to memory that was executing.
 *  Such a fashion is not enough to know if the instruction 
 *  that was just before the current DSP value has been 
 *  executed or not.
 *
 *  There are some small SCRIPTS sections that deal with 
 *  the start queue and the done queue that may break any 
 *  assomption from the C code if we are interrupted 
 *  inside, so we reset if this happens. Btw, since these 
 *  SCRIPTS sections are executed while the SCRIPTS hasn't 
 *  started SCSI operations, it is very unlikely to happen.
 *
 *  All the driver data structures are supposed to be 
 *  allocated from the same 4 GB memory window, so there 
 *  is a 1 to 1 relationship between DSA and driver data 
 *  structures. Since we are careful :) to invalidate the 
 *  DSA when we complete a command or when the SCRIPTS 
 *  pushes a DSA into a queue, we can trust it when it 
 *  points to a CCB.
 */
static void sym_recover_scsi_int (struct sym_hcb *np, u_char hsts)
{
	u32	dsp	= INL(np, nc_dsp);
	u32	dsa	= INL(np, nc_dsa);
	struct sym_ccb *cp	= sym_ccb_from_dsa(np, dsa);

	/*
	 *  If we haven't been interrupted inside the SCRIPTS 
	 *  critical pathes, we can safely restart the SCRIPTS 
	 *  and trust the DSA value if it matches a CCB.
	 */
	if ((!(dsp > SCRIPTA_BA(np, getjob_begin) &&
	       dsp < SCRIPTA_BA(np, getjob_end) + 1)) &&
	    (!(dsp > SCRIPTA_BA(np, ungetjob) &&
	       dsp < SCRIPTA_BA(np, reselect) + 1)) &&
	    (!(dsp > SCRIPTB_BA(np, sel_for_abort) &&
	       dsp < SCRIPTB_BA(np, sel_for_abort_1) + 1)) &&
	    (!(dsp > SCRIPTA_BA(np, done) &&
	       dsp < SCRIPTA_BA(np, done_end) + 1))) {
		OUTB(np, nc_ctest3, np->rv_ctest3 | CLF); /* clear dma fifo  */
		OUTB(np, nc_stest3, TE|CSF);		/* clear scsi fifo */
		/*
		 *  If we have a CCB, let the SCRIPTS call us back for 
		 *  the handling of the error with SCRATCHA filled with 
		 *  STARTPOS. This way, we will be able to freeze the 
		 *  device queue and requeue awaiting IOs.
		 */
		if (cp) {
			cp->host_status = hsts;
			OUTL_DSP(np, SCRIPTA_BA(np, complete_error));
		}
		/*
		 *  Otherwise just restart the SCRIPTS.
		 */
		else {
			OUTL(np, nc_dsa, 0xffffff);
			OUTL_DSP(np, SCRIPTA_BA(np, start));
		}
	}
	else
		goto reset_all;

	return;

reset_all:
	sym_start_reset(np);
}

/*
 *  chip exception handler for selection timeout
 */
static void sym_int_sto (struct sym_hcb *np)
{
	u32 dsp	= INL(np, nc_dsp);

	if (DEBUG_FLAGS & DEBUG_TINY) printf ("T");

	if (dsp == SCRIPTA_BA(np, wf_sel_done) + 8)
		sym_recover_scsi_int(np, HS_SEL_TIMEOUT);
	else
		sym_start_reset(np);
}

/*
 *  chip exception handler for unexpected disconnect
 */
static void sym_int_udc (struct sym_hcb *np)
{
	printf ("%s: unexpected disconnect\n", sym_name(np));
	sym_recover_scsi_int(np, HS_UNEXPECTED);
}

/*
 *  chip exception handler for SCSI bus mode change
 *
 *  spi2-r12 11.2.3 says a transceiver mode change must 
 *  generate a reset event and a device that detects a reset 
 *  event shall initiate a hard reset. It says also that a
 *  device that detects a mode change shall set data transfer 
 *  mode to eight bit asynchronous, etc...
 *  So, just reinitializing all except chip should be enough.
 */
static void sym_int_sbmc(struct Scsi_Host *shost)
{
	struct sym_hcb *np = sym_get_hcb(shost);
	u_char scsi_mode = INB(np, nc_stest4) & SMODE;

	/*
	 *  Notify user.
	 */
	printf("%s: SCSI BUS mode change from %s to %s.\n", sym_name(np),
		sym_scsi_bus_mode(np->scsi_mode), sym_scsi_bus_mode(scsi_mode));

	/*
	 *  Should suspend command processing for a few seconds and 
	 *  reinitialize all except the chip.
	 */
	sym_start_up(shost, 2);
}

/*
 *  chip exception handler for SCSI parity error.
 *
 *  When the chip detects a SCSI parity error and is 
 *  currently executing a (CH)MOV instruction, it does 
 *  not interrupt immediately, but tries to finish the 
 *  transfer of the current scatter entry before 
 *  interrupting. The following situations may occur:
 *
 *  - The complete scatter entry has been transferred 
 *    without the device having changed phase.
 *    The chip will then interrupt with the DSP pointing 
 *    to the instruction that follows the MOV.
 *
 *  - A phase mismatch occurs before the MOV finished 
 *    and phase errors are to be handled by the C code.
 *    The chip will then interrupt with both PAR and MA 
 *    conditions set.
 *
 *  - A phase mismatch occurs before the MOV finished and 
 *    phase errors are to be handled by SCRIPTS.
 *    The chip will load the DSP with the phase mismatch 
 *    JUMP address and interrupt the host processor.
 */
static void sym_int_par (struct sym_hcb *np, u_short sist)
{
	u_char	hsts	= INB(np, HS_PRT);
	u32	dsp	= INL(np, nc_dsp);
	u32	dbc	= INL(np, nc_dbc);
	u32	dsa	= INL(np, nc_dsa);
	u_char	sbcl	= INB(np, nc_sbcl);
	u_char	cmd	= dbc >> 24;
	int phase	= cmd & 7;
	struct sym_ccb *cp	= sym_ccb_from_dsa(np, dsa);

	if (printk_ratelimit())
		printf("%s: SCSI parity error detected: SCR1=%d DBC=%x SBCL=%x\n",
			sym_name(np), hsts, dbc, sbcl);

	/*
	 *  Check that the chip is connected to the SCSI BUS.
	 */
	if (!(INB(np, nc_scntl1) & ISCON)) {
		sym_recover_scsi_int(np, HS_UNEXPECTED);
		return;
	}

	/*
	 *  If the nexus is not clearly identified, reset the bus.
	 *  We will try to do better later.
	 */
	if (!cp)
		goto reset_all;

	/*
	 *  Check instruction was a MOV, direction was INPUT and 
	 *  ATN is asserted.
	 */
	if ((cmd & 0xc0) || !(phase & 1) || !(sbcl & 0x8))
		goto reset_all;

	/*
	 *  Keep track of the parity error.
	 */
	OUTONB(np, HF_PRT, HF_EXT_ERR);
	cp->xerr_status |= XE_PARITY_ERR;

	/*
	 *  Prepare the message to send to the device.
	 */
	np->msgout[0] = (phase == 7) ? M_PARITY : M_ID_ERROR;

	/*
	 *  If the old phase was DATA IN phase, we have to deal with
	 *  the 3 situations described above.
	 *  For other input phases (MSG IN and STATUS), the device 
	 *  must resend the whole thing that failed parity checking 
	 *  or signal error. So, jumping to dispatcher should be OK.
	 */
	if (phase == 1 || phase == 5) {
		/* Phase mismatch handled by SCRIPTS */
		if (dsp == SCRIPTB_BA(np, pm_handle))
			OUTL_DSP(np, dsp);
		/* Phase mismatch handled by the C code */
		else if (sist & MA)
			sym_int_ma (np);
		/* No phase mismatch occurred */
		else {
			sym_set_script_dp (np, cp, dsp);
			OUTL_DSP(np, SCRIPTA_BA(np, dispatch));
		}
	}
	else if (phase == 7)	/* We definitely cannot handle parity errors */
#if 1				/* in message-in phase due to the relection  */
		goto reset_all; /* path and various message anticipations.   */
#else
		OUTL_DSP(np, SCRIPTA_BA(np, clrack));
#endif
	else
		OUTL_DSP(np, SCRIPTA_BA(np, dispatch));
	return;

reset_all:
	sym_start_reset(np);
	return;
}

/*
 *  chip exception handler for phase errors.
 *
 *  We have to construct a new transfer descriptor,
 *  to transfer the rest of the current block.
 */
static void sym_int_ma (struct sym_hcb *np)
{
	u32	dbc;
	u32	rest;
	u32	dsp;
	u32	dsa;
	u32	nxtdsp;
	u32	*vdsp;
	u32	oadr, olen;
	u32	*tblp;
        u32	newcmd;
	u_int	delta;
	u_char	cmd;
	u_char	hflags, hflags0;
	struct	sym_pmc *pm;
	struct sym_ccb *cp;

	dsp	= INL(np, nc_dsp);
	dbc	= INL(np, nc_dbc);
	dsa	= INL(np, nc_dsa);

	cmd	= dbc >> 24;
	rest	= dbc & 0xffffff;
	delta	= 0;

	/*
	 *  locate matching cp if any.
	 */
	cp = sym_ccb_from_dsa(np, dsa);

	/*
	 *  Donnot take into account dma fifo and various buffers in 
	 *  INPUT phase since the chip flushes everything before 
	 *  raising the MA interrupt for interrupted INPUT phases.
	 *  For DATA IN phase, we will check for the SWIDE later.
	 */
	if ((cmd & 7) != 1 && (cmd & 7) != 5) {
		u_char ss0, ss2;

		if (np->features & FE_DFBC)
			delta = INW(np, nc_dfbc);
		else {
			u32 dfifo;

			/*
			 * Read DFIFO, CTEST[4-6] using 1 PCI bus ownership.
			 */
			dfifo = INL(np, nc_dfifo);

			/*
			 *  Calculate remaining bytes in DMA fifo.
			 *  (CTEST5 = dfifo >> 16)
			 */
			if (dfifo & (DFS << 16))
				delta = ((((dfifo >> 8) & 0x300) |
				          (dfifo & 0xff)) - rest) & 0x3ff;
			else
				delta = ((dfifo & 0xff) - rest) & 0x7f;
		}

		/*
		 *  The data in the dma fifo has not been transfered to
		 *  the target -> add the amount to the rest
		 *  and clear the data.
		 *  Check the sstat2 register in case of wide transfer.
		 */
		rest += delta;
		ss0  = INB(np, nc_sstat0);
		if (ss0 & OLF) rest++;
		if (!(np->features & FE_C10))
			if (ss0 & ORF) rest++;
		if (cp && (cp->phys.select.sel_scntl3 & EWS)) {
			ss2 = INB(np, nc_sstat2);
			if (ss2 & OLF1) rest++;
			if (!(np->features & FE_C10))
				if (ss2 & ORF1) rest++;
		}

		/*
		 *  Clear fifos.
		 */
		OUTB(np, nc_ctest3, np->rv_ctest3 | CLF);	/* dma fifo  */
		OUTB(np, nc_stest3, TE|CSF);		/* scsi fifo */
	}

	/*
	 *  log the information
	 */
	if (DEBUG_FLAGS & (DEBUG_TINY|DEBUG_PHASE))
		printf ("P%x%x RL=%d D=%d ", cmd&7, INB(np, nc_sbcl)&7,
			(unsigned) rest, (unsigned) delta);

	/*
	 *  try to find the interrupted script command,
	 *  and the address at which to continue.
	 */
	vdsp	= NULL;
	nxtdsp	= 0;
	if	(dsp >  np->scripta_ba &&
		 dsp <= np->scripta_ba + np->scripta_sz) {
		vdsp = (u32 *)((char*)np->scripta0 + (dsp-np->scripta_ba-8));
		nxtdsp = dsp;
	}
	else if	(dsp >  np->scriptb_ba &&
		 dsp <= np->scriptb_ba + np->scriptb_sz) {
		vdsp = (u32 *)((char*)np->scriptb0 + (dsp-np->scriptb_ba-8));
		nxtdsp = dsp;
	}

	/*
	 *  log the information
	 */
	if (DEBUG_FLAGS & DEBUG_PHASE) {
		printf ("\nCP=%p DSP=%x NXT=%x VDSP=%p CMD=%x ",
			cp, (unsigned)dsp, (unsigned)nxtdsp, vdsp, cmd);
	}

	if (!vdsp) {
		printf ("%s: interrupted SCRIPT address not found.\n", 
			sym_name (np));
		goto reset_all;
	}

	if (!cp) {
		printf ("%s: SCSI phase error fixup: CCB already dequeued.\n", 
			sym_name (np));
		goto reset_all;
	}

	/*
	 *  get old startaddress and old length.
	 */
	oadr = scr_to_cpu(vdsp[1]);

	if (cmd & 0x10) {	/* Table indirect */
		tblp = (u32 *) ((char*) &cp->phys + oadr);
		olen = scr_to_cpu(tblp[0]);
		oadr = scr_to_cpu(tblp[1]);
	} else {
		tblp = (u32 *) 0;
		olen = scr_to_cpu(vdsp[0]) & 0xffffff;
	}

	if (DEBUG_FLAGS & DEBUG_PHASE) {
		printf ("OCMD=%x\nTBLP=%p OLEN=%x OADR=%x\n",
			(unsigned) (scr_to_cpu(vdsp[0]) >> 24),
			tblp,
			(unsigned) olen,
			(unsigned) oadr);
	}

	/*
	 *  check cmd against assumed interrupted script command.
	 *  If dt data phase, the MOVE instruction hasn't bit 4 of 
	 *  the phase.
	 */
	if (((cmd & 2) ? cmd : (cmd & ~4)) != (scr_to_cpu(vdsp[0]) >> 24)) {
		sym_print_addr(cp->cmd,
			"internal error: cmd=%02x != %02x=(vdsp[0] >> 24)\n",
			cmd, scr_to_cpu(vdsp[0]) >> 24);

		goto reset_all;
	}

	/*
	 *  if old phase not dataphase, leave here.
	 */
	if (cmd & 2) {
		sym_print_addr(cp->cmd,
			"phase change %x-%x %d@%08x resid=%d.\n",
			cmd&7, INB(np, nc_sbcl)&7, (unsigned)olen,
			(unsigned)oadr, (unsigned)rest);
		goto unexpected_phase;
	}

	/*
	 *  Choose the correct PM save area.
	 *
	 *  Look at the PM_SAVE SCRIPT if you want to understand 
	 *  this stuff. The equivalent code is implemented in 
	 *  SCRIPTS for the 895A, 896 and 1010 that are able to 
	 *  handle PM from the SCRIPTS processor.
	 */
	hflags0 = INB(np, HF_PRT);
	hflags = hflags0;

	if (hflags & (HF_IN_PM0 | HF_IN_PM1 | HF_DP_SAVED)) {
		if (hflags & HF_IN_PM0)
			nxtdsp = scr_to_cpu(cp->phys.pm0.ret);
		else if	(hflags & HF_IN_PM1)
			nxtdsp = scr_to_cpu(cp->phys.pm1.ret);

		if (hflags & HF_DP_SAVED)
			hflags ^= HF_ACT_PM;
	}

	if (!(hflags & HF_ACT_PM)) {
		pm = &cp->phys.pm0;
		newcmd = SCRIPTA_BA(np, pm0_data);
	}
	else {
		pm = &cp->phys.pm1;
		newcmd = SCRIPTA_BA(np, pm1_data);
	}

	hflags &= ~(HF_IN_PM0 | HF_IN_PM1 | HF_DP_SAVED);
	if (hflags != hflags0)
		OUTB(np, HF_PRT, hflags);

	/*
	 *  fillin the phase mismatch context
	 */
	pm->sg.addr = cpu_to_scr(oadr + olen - rest);
	pm->sg.size = cpu_to_scr(rest);
	pm->ret     = cpu_to_scr(nxtdsp);

	/*
	 *  If we have a SWIDE,
	 *  - prepare the address to write the SWIDE from SCRIPTS,
	 *  - compute the SCRIPTS address to restart from,
	 *  - move current data pointer context by one byte.
	 */
	nxtdsp = SCRIPTA_BA(np, dispatch);
	if ((cmd & 7) == 1 && cp && (cp->phys.select.sel_scntl3 & EWS) &&
	    (INB(np, nc_scntl2) & WSR)) {
		u32 tmp;

		/*
		 *  Set up the table indirect for the MOVE
		 *  of the residual byte and adjust the data 
		 *  pointer context.
		 */
		tmp = scr_to_cpu(pm->sg.addr);
		cp->phys.wresid.addr = cpu_to_scr(tmp);
		pm->sg.addr = cpu_to_scr(tmp + 1);
		tmp = scr_to_cpu(pm->sg.size);
		cp->phys.wresid.size = cpu_to_scr((tmp&0xff000000) | 1);
		pm->sg.size = cpu_to_scr(tmp - 1);

		/*
		 *  If only the residual byte is to be moved, 
		 *  no PM context is needed.
		 */
		if ((tmp&0xffffff) == 1)
			newcmd = pm->ret;

		/*
		 *  Prepare the address of SCRIPTS that will 
		 *  move the residual byte to memory.
		 */
		nxtdsp = SCRIPTB_BA(np, wsr_ma_helper);
	}

	if (DEBUG_FLAGS & DEBUG_PHASE) {
		sym_print_addr(cp->cmd, "PM %x %x %x / %x %x %x.\n",
			hflags0, hflags, newcmd,
			(unsigned)scr_to_cpu(pm->sg.addr),
			(unsigned)scr_to_cpu(pm->sg.size),
			(unsigned)scr_to_cpu(pm->ret));
	}

	/*
	 *  Restart the SCRIPTS processor.
	 */
	sym_set_script_dp (np, cp, newcmd);
	OUTL_DSP(np, nxtdsp);
	return;

	/*
	 *  Unexpected phase changes that occurs when the current phase 
	 *  is not a DATA IN or DATA OUT phase are due to error conditions.
	 *  Such event may only happen when the SCRIPTS is using a 
	 *  multibyte SCSI MOVE.
	 *
	 *  Phase change		Some possible cause
	 *
	 *  COMMAND  --> MSG IN	SCSI parity error detected by target.
	 *  COMMAND  --> STATUS	Bad command or refused by target.
	 *  MSG OUT  --> MSG IN     Message rejected by target.
	 *  MSG OUT  --> COMMAND    Bogus target that discards extended
	 *  			negotiation messages.
	 *
	 *  The code below does not care of the new phase and so 
	 *  trusts the target. Why to annoy it ?
	 *  If the interrupted phase is COMMAND phase, we restart at
	 *  dispatcher.
	 *  If a target does not get all the messages after selection, 
	 *  the code assumes blindly that the target discards extended 
	 *  messages and clears the negotiation status.
	 *  If the target does not want all our response to negotiation,
	 *  we force a SIR_NEGO_PROTO interrupt (it is a hack that avoids 
	 *  bloat for such a should_not_happen situation).
	 *  In all other situation, we reset the BUS.
	 *  Are these assumptions reasonnable ? (Wait and see ...)
	 */
unexpected_phase:
	dsp -= 8;
	nxtdsp = 0;

	switch (cmd & 7) {
	case 2:	/* COMMAND phase */
		nxtdsp = SCRIPTA_BA(np, dispatch);
		break;
#if 0
	case 3:	/* STATUS  phase */
		nxtdsp = SCRIPTA_BA(np, dispatch);
		break;
#endif
	case 6:	/* MSG OUT phase */
		/*
		 *  If the device may want to use untagged when we want 
		 *  tagged, we prepare an IDENTIFY without disc. granted, 
		 *  since we will not be able to handle reselect.
		 *  Otherwise, we just don't care.
		 */
		if	(dsp == SCRIPTA_BA(np, send_ident)) {
			if (cp->tag != NO_TAG && olen - rest <= 3) {
				cp->host_status = HS_BUSY;
				np->msgout[0] = IDENTIFY(0, cp->lun);
				nxtdsp = SCRIPTB_BA(np, ident_break_atn);
			}
			else
				nxtdsp = SCRIPTB_BA(np, ident_break);
		}
		else if	(dsp == SCRIPTB_BA(np, send_wdtr) ||
			 dsp == SCRIPTB_BA(np, send_sdtr) ||
			 dsp == SCRIPTB_BA(np, send_ppr)) {
			nxtdsp = SCRIPTB_BA(np, nego_bad_phase);
			if (dsp == SCRIPTB_BA(np, send_ppr)) {
				struct scsi_device *dev = cp->cmd->device;
				dev->ppr = 0;
			}
		}
		break;
#if 0
	case 7:	/* MSG IN  phase */
		nxtdsp = SCRIPTA_BA(np, clrack);
		break;
#endif
	}

	if (nxtdsp) {
		OUTL_DSP(np, nxtdsp);
		return;
	}

reset_all:
	sym_start_reset(np);
}

/*
 *  chip interrupt handler
 *
 *  In normal situations, interrupt conditions occur one at 
 *  a time. But when something bad happens on the SCSI BUS, 
 *  the chip may raise several interrupt flags before 
 *  stopping and interrupting the CPU. The additionnal 
 *  interrupt flags are stacked in some extra registers 
 *  after the SIP and/or DIP flag has been raised in the 
 *  ISTAT. After the CPU has read the interrupt condition 
 *  flag from SIST or DSTAT, the chip unstacks the other 
 *  interrupt flags and sets the corresponding bits in 
 *  SIST or DSTAT. Since the chip starts stacking once the 
 *  SIP or DIP flag is set, there is a small window of time 
 *  where the stacking does not occur.
 *
 *  Typically, multiple interrupt conditions may happen in 
 *  the following situations:
 *
 *  - SCSI parity error + Phase mismatch  (PAR|MA)
 *    When an parity error is detected in input phase 
 *    and the device switches to msg-in phase inside a 
 *    block MOV.
 *  - SCSI parity error + Unexpected disconnect (PAR|UDC)
 *    When a stupid device does not want to handle the 
 *    recovery of an SCSI parity error.
 *  - Some combinations of STO, PAR, UDC, ...
 *    When using non compliant SCSI stuff, when user is 
 *    doing non compliant hot tampering on the BUS, when 
 *    something really bad happens to a device, etc ...
 *
 *  The heuristic suggested by SYMBIOS to handle 
 *  multiple interrupts is to try unstacking all 
 *  interrupts conditions and to handle them on some 
 *  priority based on error severity.
 *  This will work when the unstacking has been 
 *  successful, but we cannot be 100 % sure of that, 
 *  since the CPU may have been faster to unstack than 
 *  the chip is able to stack. Hmmm ... But it seems that 
 *  such a situation is very unlikely to happen.
 *
 *  If this happen, for example STO caught by the CPU 
 *  then UDC happenning before the CPU have restarted 
 *  the SCRIPTS, the driver may wrongly complete the 
 *  same command on UDC, since the SCRIPTS didn't restart 
 *  and the DSA still points to the same command.
 *  We avoid this situation by setting the DSA to an 
 *  invalid value when the CCB is completed and before 
 *  restarting the SCRIPTS.
 *
 *  Another issue is that we need some section of our 
 *  recovery procedures to be somehow uninterruptible but 
 *  the SCRIPTS processor does not provides such a 
 *  feature. For this reason, we handle recovery preferently 
 *  from the C code and check against some SCRIPTS critical 
 *  sections from the C code.
 *
 *  Hopefully, the interrupt handling of the driver is now 
 *  able to resist to weird BUS error conditions, but donnot 
 *  ask me for any guarantee that it will never fail. :-)
 *  Use at your own decision and risk.
 */

irqreturn_t sym_interrupt(struct Scsi_Host *shost)
{
	struct sym_data *sym_data = shost_priv(shost);
	struct sym_hcb *np = sym_data->ncb;
	struct pci_dev *pdev = sym_data->pdev;
	u_char	istat, istatc;
	u_char	dstat;
	u_short	sist;

	/*
	 *  interrupt on the fly ?
	 *  (SCRIPTS may still be running)
	 *
	 *  A `dummy read' is needed to ensure that the 
	 *  clear of the INTF flag reaches the device 
	 *  and that posted writes are flushed to memory
	 *  before the scanning of the DONE queue.
	 *  Note that SCRIPTS also (dummy) read to memory 
	 *  prior to deliver the INTF interrupt condition.
	 */
	istat = INB(np, nc_istat);
	if (istat & INTF) {
		OUTB(np, nc_istat, (istat & SIGP) | INTF | np->istat_sem);
		istat |= INB(np, nc_istat);		/* DUMMY READ */
		if (DEBUG_FLAGS & DEBUG_TINY) printf ("F ");
		sym_wakeup_done(np);
	}

	if (!(istat & (SIP|DIP)))
		return (istat & INTF) ? IRQ_HANDLED : IRQ_NONE;

#if 0	/* We should never get this one */
	if (istat & CABRT)
		OUTB(np, nc_istat, CABRT);
#endif

	/*
	 *  PAR and MA interrupts may occur at the same time,
	 *  and we need to know of both in order to handle 
	 *  this situation properly. We try to unstack SCSI 
	 *  interrupts for that reason. BTW, I dislike a LOT 
	 *  such a loop inside the interrupt routine.
	 *  Even if DMA interrupt stacking is very unlikely to 
	 *  happen, we also try unstacking these ones, since 
	 *  this has no performance impact.
	 */
	sist	= 0;
	dstat	= 0;
	istatc	= istat;
	do {
		if (istatc & SIP)
			sist  |= INW(np, nc_sist);
		if (istatc & DIP)
			dstat |= INB(np, nc_dstat);
		istatc = INB(np, nc_istat);
		istat |= istatc;

		/* Prevent deadlock waiting on a condition that may
		 * never clear. */
		if (unlikely(sist == 0xffff && dstat == 0xff)) {
			if (pci_channel_offline(pdev))
				return IRQ_NONE;
		}
	} while (istatc & (SIP|DIP));

	if (DEBUG_FLAGS & DEBUG_TINY)
		printf ("<%d|%x:%x|%x:%x>",
			(int)INB(np, nc_scr0),
			dstat,sist,
			(unsigned)INL(np, nc_dsp),
			(unsigned)INL(np, nc_dbc));
	/*
	 *  On paper, a memory read barrier may be needed here to 
	 *  prevent out of order LOADs by the CPU from having 
	 *  prefetched stale data prior to DMA having occurred.
	 *  And since we are paranoid ... :)
	 */
	MEMORY_READ_BARRIER();

	/*
	 *  First, interrupts we want to service cleanly.
	 *
	 *  Phase mismatch (MA) is the most frequent interrupt 
	 *  for chip earlier than the 896 and so we have to service 
	 *  it as quickly as possible.
	 *  A SCSI parity error (PAR) may be combined with a phase 
	 *  mismatch condition (MA).
	 *  Programmed interrupts (SIR) are used to call the C code 
	 *  from SCRIPTS.
	 *  The single step interrupt (SSI) is not used in this 
	 *  driver.
	 */
	if (!(sist  & (STO|GEN|HTH|SGE|UDC|SBMC|RST)) &&
	    !(dstat & (MDPE|BF|ABRT|IID))) {
		if	(sist & PAR)	sym_int_par (np, sist);
		else if (sist & MA)	sym_int_ma (np);
		else if (dstat & SIR)	sym_int_sir(np);
		else if (dstat & SSI)	OUTONB_STD();
		else			goto unknown_int;
		return IRQ_HANDLED;
	}

	/*
	 *  Now, interrupts that donnot happen in normal 
	 *  situations and that we may need to recover from.
	 *
	 *  On SCSI RESET (RST), we reset everything.
	 *  On SCSI BUS MODE CHANGE (SBMC), we complete all 
	 *  active CCBs with RESET status, prepare all devices 
	 *  for negotiating again and restart the SCRIPTS.
	 *  On STO and UDC, we complete the CCB with the corres- 
	 *  ponding status and restart the SCRIPTS.
	 */
	if (sist & RST) {
		printf("%s: SCSI BUS reset detected.\n", sym_name(np));
		sym_start_up(shost, 1);
		return IRQ_HANDLED;
	}

	OUTB(np, nc_ctest3, np->rv_ctest3 | CLF);	/* clear dma fifo  */
	OUTB(np, nc_stest3, TE|CSF);		/* clear scsi fifo */

	if (!(sist  & (GEN|HTH|SGE)) &&
	    !(dstat & (MDPE|BF|ABRT|IID))) {
		if	(sist & SBMC)	sym_int_sbmc(shost);
		else if (sist & STO)	sym_int_sto (np);
		else if (sist & UDC)	sym_int_udc (np);
		else			goto unknown_int;
		return IRQ_HANDLED;
	}

	/*
	 *  Now, interrupts we are not able to recover cleanly.
	 *
	 *  Log message for hard errors.
	 *  Reset everything.
	 */

	sym_log_hard_error(shost, sist, dstat);

	if ((sist & (GEN|HTH|SGE)) ||
		(dstat & (MDPE|BF|ABRT|IID))) {
		sym_start_reset(np);
		return IRQ_HANDLED;
	}

unknown_int:
	/*
	 *  We just miss the cause of the interrupt. :(
	 *  Print a message. The timeout will do the real work.
	 */
	printf(	"%s: unknown interrupt(s) ignored, "
		"ISTAT=0x%x DSTAT=0x%x SIST=0x%x\n",
		sym_name(np), istat, dstat, sist);
	return IRQ_NONE;
}

/*
 *  Dequeue from the START queue all CCBs that match 
 *  a given target/lun/task condition (-1 means all),
 *  and move them from the BUSY queue to the COMP queue 
 *  with DID_SOFT_ERROR status condition.
 *  This function is used during error handling/recovery.
 *  It is called with SCRIPTS not running.
 */
static int 
sym_dequeue_from_squeue(struct sym_hcb *np, int i, int target, int lun, int task)
{
	int j;
	struct sym_ccb *cp;

	/*
	 *  Make sure the starting index is within range.
	 */
	assert((i >= 0) && (i < 2*MAX_QUEUE));

	/*
	 *  Walk until end of START queue and dequeue every job 
	 *  that matches the target/lun/task condition.
	 */
	j = i;
	while (i != np->squeueput) {
		cp = sym_ccb_from_dsa(np, scr_to_cpu(np->squeue[i]));
		assert(cp);
#ifdef SYM_CONF_IARB_SUPPORT
		/* Forget hints for IARB, they may be no longer relevant */
		cp->host_flags &= ~HF_HINT_IARB;
#endif
		if ((target == -1 || cp->target == target) &&
		    (lun    == -1 || cp->lun    == lun)    &&
		    (task   == -1 || cp->tag    == task)) {
			sym_set_cam_status(cp->cmd, DID_SOFT_ERROR);
			sym_remque(&cp->link_ccbq);
			sym_insque_tail(&cp->link_ccbq, &np->comp_ccbq);
		}
		else {
			if (i != j)
				np->squeue[j] = np->squeue[i];
			if ((j += 2) >= MAX_QUEUE*2) j = 0;
		}
		if ((i += 2) >= MAX_QUEUE*2) i = 0;
	}
	if (i != j)		/* Copy back the idle task if needed */
		np->squeue[j] = np->squeue[i];
	np->squeueput = j;	/* Update our current start queue pointer */

	return (i - j) / 2;
}

/*
 *  chip handler for bad SCSI status condition
 *
 *  In case of bad SCSI status, we unqueue all the tasks 
 *  currently queued to the controller but not yet started 
 *  and then restart the SCRIPTS processor immediately.
 *
 *  QUEUE FULL and BUSY conditions are handled the same way.
 *  Basically all the not yet started tasks are requeued in 
 *  device queue and the queue is frozen until a completion.
 *
 *  For CHECK CONDITION and COMMAND TERMINATED status, we use 
 *  the CCB of the failed command to prepare a REQUEST SENSE 
 *  SCSI command and queue it to the controller queue.
 *
 *  SCRATCHA is assumed to have been loaded with STARTPOS 
 *  before the SCRIPTS called the C code.
 */
static void sym_sir_bad_scsi_status(struct sym_hcb *np, int num, struct sym_ccb *cp)
{
	u32		startp;
	u_char		s_status = cp->ssss_status;
	u_char		h_flags  = cp->host_flags;
	int		msglen;
	int		i;

	/*
	 *  Compute the index of the next job to start from SCRIPTS.
	 */
	i = (INL(np, nc_scratcha) - np->squeue_ba) / 4;

	/*
	 *  The last CCB queued used for IARB hint may be 
	 *  no longer relevant. Forget it.
	 */
#ifdef SYM_CONF_IARB_SUPPORT
	if (np->last_cp)
		np->last_cp = 0;
#endif

	/*
	 *  Now deal with the SCSI status.
	 */
	switch(s_status) {
	case S_BUSY:
	case S_QUEUE_FULL:
		if (sym_verbose >= 2) {
			sym_print_addr(cp->cmd, "%s\n",
			        s_status == S_BUSY ? "BUSY" : "QUEUE FULL\n");
		}
	default:	/* S_INT, S_INT_COND_MET, S_CONFLICT */
		sym_complete_error (np, cp);
		break;
	case S_TERMINATED:
	case S_CHECK_COND:
		/*
		 *  If we get an SCSI error when requesting sense, give up.
		 */
		if (h_flags & HF_SENSE) {
			sym_complete_error (np, cp);
			break;
		}

		/*
		 *  Dequeue all queued CCBs for that device not yet started,
		 *  and restart the SCRIPTS processor immediately.
		 */
		sym_dequeue_from_squeue(np, i, cp->target, cp->lun, -1);
		OUTL_DSP(np, SCRIPTA_BA(np, start));

 		/*
		 *  Save some info of the actual IO.
		 *  Compute the data residual.
		 */
		cp->sv_scsi_status = cp->ssss_status;
		cp->sv_xerr_status = cp->xerr_status;
		cp->sv_resid = sym_compute_residual(np, cp);

		/*
		 *  Prepare all needed data structures for 
		 *  requesting sense data.
		 */

		cp->scsi_smsg2[0] = IDENTIFY(0, cp->lun);
		msglen = 1;

		/*
		 *  If we are currently using anything different from 
		 *  async. 8 bit data transfers with that target,
		 *  start a negotiation, since the device may want 
		 *  to report us a UNIT ATTENTION condition due to 
		 *  a cause we currently ignore, and we donnot want 
		 *  to be stuck with WIDE and/or SYNC data transfer.
		 *
		 *  cp->nego_status is filled by sym_prepare_nego().
		 */
		cp->nego_status = 0;
		msglen += sym_prepare_nego(np, cp, &cp->scsi_smsg2[msglen]);
		/*
		 *  Message table indirect structure.
		 */
		cp->phys.smsg.addr	= CCB_BA(cp, scsi_smsg2);
		cp->phys.smsg.size	= cpu_to_scr(msglen);

		/*
		 *  sense command
		 */
		cp->phys.cmd.addr	= CCB_BA(cp, sensecmd);
		cp->phys.cmd.size	= cpu_to_scr(6);

		/*
		 *  patch requested size into sense command
		 */
		cp->sensecmd[0]		= REQUEST_SENSE;
		cp->sensecmd[1]		= 0;
		if (cp->cmd->device->scsi_level <= SCSI_2 && cp->lun <= 7)
			cp->sensecmd[1]	= cp->lun << 5;
		cp->sensecmd[4]		= SYM_SNS_BBUF_LEN;
		cp->data_len		= SYM_SNS_BBUF_LEN;

		/*
		 *  sense data
		 */
		memset(cp->sns_bbuf, 0, SYM_SNS_BBUF_LEN);
		cp->phys.sense.addr	= CCB_BA(cp, sns_bbuf);
		cp->phys.sense.size	= cpu_to_scr(SYM_SNS_BBUF_LEN);

		/*
		 *  requeue the command.
		 */
		startp = SCRIPTB_BA(np, sdata_in);

		cp->phys.head.savep	= cpu_to_scr(startp);
		cp->phys.head.lastp	= cpu_to_scr(startp);
		cp->startp		= cpu_to_scr(startp);
		cp->goalp		= cpu_to_scr(startp + 16);

		cp->host_xflags = 0;
		cp->host_status	= cp->nego_status ? HS_NEGOTIATE : HS_BUSY;
		cp->ssss_status = S_ILLEGAL;
		cp->host_flags	= (HF_SENSE|HF_DATA_IN);
		cp->xerr_status = 0;
		cp->extra_bytes = 0;

		cp->phys.head.go.start = cpu_to_scr(SCRIPTA_BA(np, select));

		/*
		 *  Requeue the command.
		 */
		sym_put_start_queue(np, cp);

		/*
		 *  Give back to upper layer everything we have dequeued.
		 */
		sym_flush_comp_queue(np, 0);
		break;
	}
}

/*
 *  After a device has accepted some management message 
 *  as BUS DEVICE RESET, ABORT TASK, etc ..., or when 
 *  a device signals a UNIT ATTENTION condition, some 
 *  tasks are thrown away by the device. We are required 
 *  to reflect that on our tasks list since the device 
 *  will never complete these tasks.
 *
 *  This function move from the BUSY queue to the COMP 
 *  queue all disconnected CCBs for a given target that 
 *  match the following criteria:
 *  - lun=-1  means any logical UNIT otherwise a given one.
 *  - task=-1 means any task, otherwise a given one.
 */
int sym_clear_tasks(struct sym_hcb *np, int cam_status, int target, int lun, int task)
{
	SYM_QUEHEAD qtmp, *qp;
	int i = 0;
	struct sym_ccb *cp;

	/*
	 *  Move the entire BUSY queue to our temporary queue.
	 */
	sym_que_init(&qtmp);
	sym_que_splice(&np->busy_ccbq, &qtmp);
	sym_que_init(&np->busy_ccbq);

	/*
	 *  Put all CCBs that matches our criteria into 
	 *  the COMP queue and put back other ones into 
	 *  the BUSY queue.
	 */
	while ((qp = sym_remque_head(&qtmp)) != NULL) {
		struct scsi_cmnd *cmd;
		cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
		cmd = cp->cmd;
		if (cp->host_status != HS_DISCONNECT ||
		    cp->target != target	     ||
		    (lun  != -1 && cp->lun != lun)   ||
		    (task != -1 && 
			(cp->tag != NO_TAG && cp->scsi_smsg[2] != task))) {
			sym_insque_tail(&cp->link_ccbq, &np->busy_ccbq);
			continue;
		}
		sym_insque_tail(&cp->link_ccbq, &np->comp_ccbq);

		/* Preserve the software timeout condition */
		if (sym_get_cam_status(cmd) != DID_TIME_OUT)
			sym_set_cam_status(cmd, cam_status);
		++i;
#if 0
printf("XXXX TASK @%p CLEARED\n", cp);
#endif
	}
	return i;
}

/*
 *  chip handler for TASKS recovery
 *
 *  We cannot safely abort a command, while the SCRIPTS 
 *  processor is running, since we just would be in race 
 *  with it.
 *
 *  As long as we have tasks to abort, we keep the SEM 
 *  bit set in the ISTAT. When this bit is set, the 
 *  SCRIPTS processor interrupts (SIR_SCRIPT_STOPPED) 
 *  each time it enters the scheduler.
 *
 *  If we have to reset a target, clear tasks of a unit,
 *  or to perform the abort of a disconnected job, we 
 *  restart the SCRIPTS for selecting the target. Once 
 *  selected, the SCRIPTS interrupts (SIR_TARGET_SELECTED).
 *  If it loses arbitration, the SCRIPTS will interrupt again 
 *  the next time it will enter its scheduler, and so on ...
 *
 *  On SIR_TARGET_SELECTED, we scan for the more 
 *  appropriate thing to do:
 *
 *  - If nothing, we just sent a M_ABORT message to the 
 *    target to get rid of the useless SCSI bus ownership.
 *    According to the specs, no tasks shall be affected.
 *  - If the target is to be reset, we send it a M_RESET 
 *    message.
 *  - If a logical UNIT is to be cleared , we send the 
 *    IDENTIFY(lun) + M_ABORT.
 *  - If an untagged task is to be aborted, we send the 
 *    IDENTIFY(lun) + M_ABORT.
 *  - If a tagged task is to be aborted, we send the 
 *    IDENTIFY(lun) + task attributes + M_ABORT_TAG.
 *
 *  Once our 'kiss of death' :) message has been accepted 
 *  by the target, the SCRIPTS interrupts again 
 *  (SIR_ABORT_SENT). On this interrupt, we complete 
 *  all the CCBs that should have been aborted by the 
 *  target according to our message.
 */
static void sym_sir_task_recovery(struct sym_hcb *np, int num)
{
	SYM_QUEHEAD *qp;
	struct sym_ccb *cp;
	struct sym_tcb *tp = NULL; /* gcc isn't quite smart enough yet */
	struct scsi_target *starget;
	int target=-1, lun=-1, task;
	int i, k;

	switch(num) {
	/*
	 *  The SCRIPTS processor stopped before starting
	 *  the next command in order to allow us to perform 
	 *  some task recovery.
	 */
	case SIR_SCRIPT_STOPPED:
		/*
		 *  Do we have any target to reset or unit to clear ?
		 */
		for (i = 0 ; i < SYM_CONF_MAX_TARGET ; i++) {
			tp = &np->target[i];
			if (tp->to_reset || 
			    (tp->lun0p && tp->lun0p->to_clear)) {
				target = i;
				break;
			}
			if (!tp->lunmp)
				continue;
			for (k = 1 ; k < SYM_CONF_MAX_LUN ; k++) {
				if (tp->lunmp[k] && tp->lunmp[k]->to_clear) {
					target	= i;
					break;
				}
			}
			if (target != -1)
				break;
		}

		/*
		 *  If not, walk the busy queue for any 
		 *  disconnected CCB to be aborted.
		 */
		if (target == -1) {
			FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
				cp = sym_que_entry(qp,struct sym_ccb,link_ccbq);
				if (cp->host_status != HS_DISCONNECT)
					continue;
				if (cp->to_abort) {
					target = cp->target;
					break;
				}
			}
		}

		/*
		 *  If some target is to be selected, 
		 *  prepare and start the selection.
		 */
		if (target != -1) {
			tp = &np->target[target];
			np->abrt_sel.sel_id	= target;
			np->abrt_sel.sel_scntl3 = tp->head.wval;
			np->abrt_sel.sel_sxfer  = tp->head.sval;
			OUTL(np, nc_dsa, np->hcb_ba);
			OUTL_DSP(np, SCRIPTB_BA(np, sel_for_abort));
			return;
		}

		/*
		 *  Now look for a CCB to abort that haven't started yet.
		 *  Btw, the SCRIPTS processor is still stopped, so 
		 *  we are not in race.
		 */
		i = 0;
		cp = NULL;
		FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
			cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
			if (cp->host_status != HS_BUSY &&
			    cp->host_status != HS_NEGOTIATE)
				continue;
			if (!cp->to_abort)
				continue;
#ifdef SYM_CONF_IARB_SUPPORT
			/*
			 *    If we are using IMMEDIATE ARBITRATION, we donnot 
			 *    want to cancel the last queued CCB, since the 
			 *    SCRIPTS may have anticipated the selection.
			 */
			if (cp == np->last_cp) {
				cp->to_abort = 0;
				continue;
			}
#endif
			i = 1;	/* Means we have found some */
			break;
		}
		if (!i) {
			/*
			 *  We are done, so we donnot need 
			 *  to synchronize with the SCRIPTS anylonger.
			 *  Remove the SEM flag from the ISTAT.
			 */
			np->istat_sem = 0;
			OUTB(np, nc_istat, SIGP);
			break;
		}
		/*
		 *  Compute index of next position in the start 
		 *  queue the SCRIPTS intends to start and dequeue 
		 *  all CCBs for that device that haven't been started.
		 */
		i = (INL(np, nc_scratcha) - np->squeue_ba) / 4;
		i = sym_dequeue_from_squeue(np, i, cp->target, cp->lun, -1);

		/*
		 *  Make sure at least our IO to abort has been dequeued.
		 */
#ifndef SYM_OPT_HANDLE_DEVICE_QUEUEING
		assert(i && sym_get_cam_status(cp->cmd) == DID_SOFT_ERROR);
#else
		sym_remque(&cp->link_ccbq);
		sym_insque_tail(&cp->link_ccbq, &np->comp_ccbq);
#endif
		/*
		 *  Keep track in cam status of the reason of the abort.
		 */
		if (cp->to_abort == 2)
			sym_set_cam_status(cp->cmd, DID_TIME_OUT);
		else
			sym_set_cam_status(cp->cmd, DID_ABORT);

		/*
		 *  Complete with error everything that we have dequeued.
	 	 */
		sym_flush_comp_queue(np, 0);
		break;
	/*
	 *  The SCRIPTS processor has selected a target 
	 *  we may have some manual recovery to perform for.
	 */
	case SIR_TARGET_SELECTED:
		target = INB(np, nc_sdid) & 0xf;
		tp = &np->target[target];

		np->abrt_tbl.addr = cpu_to_scr(vtobus(np->abrt_msg));

		/*
		 *  If the target is to be reset, prepare a 
		 *  M_RESET message and clear the to_reset flag 
		 *  since we donnot expect this operation to fail.
		 */
		if (tp->to_reset) {
			np->abrt_msg[0] = M_RESET;
			np->abrt_tbl.size = 1;
			tp->to_reset = 0;
			break;
		}

		/*
		 *  Otherwise, look for some logical unit to be cleared.
		 */
		if (tp->lun0p && tp->lun0p->to_clear)
			lun = 0;
		else if (tp->lunmp) {
			for (k = 1 ; k < SYM_CONF_MAX_LUN ; k++) {
				if (tp->lunmp[k] && tp->lunmp[k]->to_clear) {
					lun = k;
					break;
				}
			}
		}

		/*
		 *  If a logical unit is to be cleared, prepare 
		 *  an IDENTIFY(lun) + ABORT MESSAGE.
		 */
		if (lun != -1) {
			struct sym_lcb *lp = sym_lp(tp, lun);
			lp->to_clear = 0; /* We don't expect to fail here */
			np->abrt_msg[0] = IDENTIFY(0, lun);
			np->abrt_msg[1] = M_ABORT;
			np->abrt_tbl.size = 2;
			break;
		}

		/*
		 *  Otherwise, look for some disconnected job to 
		 *  abort for this target.
		 */
		i = 0;
		cp = NULL;
		FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
			cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
			if (cp->host_status != HS_DISCONNECT)
				continue;
			if (cp->target != target)
				continue;
			if (!cp->to_abort)
				continue;
			i = 1;	/* Means we have some */
			break;
		}

		/*
		 *  If we have none, probably since the device has 
		 *  completed the command before we won abitration,
		 *  send a M_ABORT message without IDENTIFY.
		 *  According to the specs, the device must just 
		 *  disconnect the BUS and not abort any task.
		 */
		if (!i) {
			np->abrt_msg[0] = M_ABORT;
			np->abrt_tbl.size = 1;
			break;
		}

		/*
		 *  We have some task to abort.
		 *  Set the IDENTIFY(lun)
		 */
		np->abrt_msg[0] = IDENTIFY(0, cp->lun);

		/*
		 *  If we want to abort an untagged command, we 
		 *  will send a IDENTIFY + M_ABORT.
		 *  Otherwise (tagged command), we will send 
		 *  a IDENTITFY + task attributes + ABORT TAG.
		 */
		if (cp->tag == NO_TAG) {
			np->abrt_msg[1] = M_ABORT;
			np->abrt_tbl.size = 2;
		} else {
			np->abrt_msg[1] = cp->scsi_smsg[1];
			np->abrt_msg[2] = cp->scsi_smsg[2];
			np->abrt_msg[3] = M_ABORT_TAG;
			np->abrt_tbl.size = 4;
		}
		/*
		 *  Keep track of software timeout condition, since the 
		 *  peripheral driver may not count retries on abort 
		 *  conditions not due to timeout.
		 */
		if (cp->to_abort == 2)
			sym_set_cam_status(cp->cmd, DID_TIME_OUT);
		cp->to_abort = 0; /* We donnot expect to fail here */
		break;

	/*
	 *  The target has accepted our message and switched 
	 *  to BUS FREE phase as we expected.
	 */
	case SIR_ABORT_SENT:
		target = INB(np, nc_sdid) & 0xf;
		tp = &np->target[target];
		starget = tp->starget;
		
		/*
		**  If we didn't abort anything, leave here.
		*/
		if (np->abrt_msg[0] == M_ABORT)
			break;

		/*
		 *  If we sent a M_RESET, then a hardware reset has 
		 *  been performed by the target.
		 *  - Reset everything to async 8 bit
		 *  - Tell ourself to negotiate next time :-)
		 *  - Prepare to clear all disconnected CCBs for 
		 *    this target from our task list (lun=task=-1)
		 */
		lun = -1;
		task = -1;
		if (np->abrt_msg[0] == M_RESET) {
			tp->head.sval = 0;
			tp->head.wval = np->rv_scntl3;
			tp->head.uval = 0;
			spi_period(starget) = 0;
			spi_offset(starget) = 0;
			spi_width(starget) = 0;
			spi_iu(starget) = 0;
			spi_dt(starget) = 0;
			spi_qas(starget) = 0;
			tp->tgoal.check_nego = 1;
			tp->tgoal.renego = 0;
		}

		/*
		 *  Otherwise, check for the LUN and TASK(s) 
		 *  concerned by the cancelation.
		 *  If it is not ABORT_TAG then it is CLEAR_QUEUE 
		 *  or an ABORT message :-)
		 */
		else {
			lun = np->abrt_msg[0] & 0x3f;
			if (np->abrt_msg[1] == M_ABORT_TAG)
				task = np->abrt_msg[2];
		}

		/*
		 *  Complete all the CCBs the device should have 
		 *  aborted due to our 'kiss of death' message.
		 */
		i = (INL(np, nc_scratcha) - np->squeue_ba) / 4;
		sym_dequeue_from_squeue(np, i, target, lun, -1);
		sym_clear_tasks(np, DID_ABORT, target, lun, task);
		sym_flush_comp_queue(np, 0);

 		/*
		 *  If we sent a BDR, make upper layer aware of that.
 		 */
		if (np->abrt_msg[0] == M_RESET)
			starget_printk(KERN_NOTICE, starget,
							"has been reset\n");
		break;
	}

	/*
	 *  Print to the log the message we intend to send.
	 */
	if (num == SIR_TARGET_SELECTED) {
		dev_info(&tp->starget->dev, "control msgout:");
		sym_printl_hex(np->abrt_msg, np->abrt_tbl.size);
		np->abrt_tbl.size = cpu_to_scr(np->abrt_tbl.size);
	}

	/*
	 *  Let the SCRIPTS processor continue.
	 */
	OUTONB_STD();
}

/*
 *  Gerard's alchemy:) that deals with with the data 
 *  pointer for both MDP and the residual calculation.
 *
 *  I didn't want to bloat the code by more than 200 
 *  lines for the handling of both MDP and the residual.
 *  This has been achieved by using a data pointer 
 *  representation consisting in an index in the data 
 *  array (dp_sg) and a negative offset (dp_ofs) that 
 *  have the following meaning:
 *
 *  - dp_sg = SYM_CONF_MAX_SG
 *    we are at the end of the data script.
 *  - dp_sg < SYM_CONF_MAX_SG
 *    dp_sg points to the next entry of the scatter array 
 *    we want to transfer.
 *  - dp_ofs < 0
 *    dp_ofs represents the residual of bytes of the 
 *    previous entry scatter entry we will send first.
 *  - dp_ofs = 0
 *    no residual to send first.
 *
 *  The function sym_evaluate_dp() accepts an arbitray 
 *  offset (basically from the MDP message) and returns 
 *  the corresponding values of dp_sg and dp_ofs.
 */

static int sym_evaluate_dp(struct sym_hcb *np, struct sym_ccb *cp, u32 scr, int *ofs)
{
	u32	dp_scr;
	int	dp_ofs, dp_sg, dp_sgmin;
	int	tmp;
	struct sym_pmc *pm;

	/*
	 *  Compute the resulted data pointer in term of a script 
	 *  address within some DATA script and a signed byte offset.
	 */
	dp_scr = scr;
	dp_ofs = *ofs;
	if	(dp_scr == SCRIPTA_BA(np, pm0_data))
		pm = &cp->phys.pm0;
	else if (dp_scr == SCRIPTA_BA(np, pm1_data))
		pm = &cp->phys.pm1;
	else
		pm = NULL;

	if (pm) {
		dp_scr  = scr_to_cpu(pm->ret);
		dp_ofs -= scr_to_cpu(pm->sg.size) & 0x00ffffff;
	}

	/*
	 *  If we are auto-sensing, then we are done.
	 */
	if (cp->host_flags & HF_SENSE) {
		*ofs = dp_ofs;
		return 0;
	}

	/*
	 *  Deduce the index of the sg entry.
	 *  Keep track of the index of the first valid entry.
	 *  If result is dp_sg = SYM_CONF_MAX_SG, then we are at the 
	 *  end of the data.
	 */
	tmp = scr_to_cpu(cp->goalp);
	dp_sg = SYM_CONF_MAX_SG;
	if (dp_scr != tmp)
		dp_sg -= (tmp - 8 - (int)dp_scr) / (2*4);
	dp_sgmin = SYM_CONF_MAX_SG - cp->segments;

	/*
	 *  Move to the sg entry the data pointer belongs to.
	 *
	 *  If we are inside the data area, we expect result to be:
	 *
	 *  Either,
	 *      dp_ofs = 0 and dp_sg is the index of the sg entry
	 *      the data pointer belongs to (or the end of the data)
	 *  Or,
	 *      dp_ofs < 0 and dp_sg is the index of the sg entry 
	 *      the data pointer belongs to + 1.
	 */
	if (dp_ofs < 0) {
		int n;
		while (dp_sg > dp_sgmin) {
			--dp_sg;
			tmp = scr_to_cpu(cp->phys.data[dp_sg].size);
			n = dp_ofs + (tmp & 0xffffff);
			if (n > 0) {
				++dp_sg;
				break;
			}
			dp_ofs = n;
		}
	}
	else if (dp_ofs > 0) {
		while (dp_sg < SYM_CONF_MAX_SG) {
			tmp = scr_to_cpu(cp->phys.data[dp_sg].size);
			dp_ofs -= (tmp & 0xffffff);
			++dp_sg;
			if (dp_ofs <= 0)
				break;
		}
	}

	/*
	 *  Make sure the data pointer is inside the data area.
	 *  If not, return some error.
	 */
	if	(dp_sg < dp_sgmin || (dp_sg == dp_sgmin && dp_ofs < 0))
		goto out_err;
	else if	(dp_sg > SYM_CONF_MAX_SG ||
		 (dp_sg == SYM_CONF_MAX_SG && dp_ofs > 0))
		goto out_err;

	/*
	 *  Save the extreme pointer if needed.
	 */
	if (dp_sg > cp->ext_sg ||
            (dp_sg == cp->ext_sg && dp_ofs > cp->ext_ofs)) {
		cp->ext_sg  = dp_sg;
		cp->ext_ofs = dp_ofs;
	}

	/*
	 *  Return data.
	 */
	*ofs = dp_ofs;
	return dp_sg;

out_err:
	return -1;
}

/*
 *  chip handler for MODIFY DATA POINTER MESSAGE
 *
 *  We also call this function on IGNORE WIDE RESIDUE 
 *  messages that do not match a SWIDE full condition.
 *  Btw, we assume in that situation that such a message 
 *  is equivalent to a MODIFY DATA POINTER (offset=-1).
 */

static void sym_modify_dp(struct sym_hcb *np, struct sym_tcb *tp, struct sym_ccb *cp, int ofs)
{
	int dp_ofs	= ofs;
	u32	dp_scr	= sym_get_script_dp (np, cp);
	u32	dp_ret;
	u32	tmp;
	u_char	hflags;
	int	dp_sg;
	struct	sym_pmc *pm;

	/*
	 *  Not supported for auto-sense.
	 */
	if (cp->host_flags & HF_SENSE)
		goto out_reject;

	/*
	 *  Apply our alchemy:) (see comments in sym_evaluate_dp()), 
	 *  to the resulted data pointer.
	 */
	dp_sg = sym_evaluate_dp(np, cp, dp_scr, &dp_ofs);
	if (dp_sg < 0)
		goto out_reject;

	/*
	 *  And our alchemy:) allows to easily calculate the data 
	 *  script address we want to return for the next data phase.
	 */
	dp_ret = cpu_to_scr(cp->goalp);
	dp_ret = dp_ret - 8 - (SYM_CONF_MAX_SG - dp_sg) * (2*4);

	/*
	 *  If offset / scatter entry is zero we donnot need 
	 *  a context for the new current data pointer.
	 */
	if (dp_ofs == 0) {
		dp_scr = dp_ret;
		goto out_ok;
	}

	/*
	 *  Get a context for the new current data pointer.
	 */
	hflags = INB(np, HF_PRT);

	if (hflags & HF_DP_SAVED)
		hflags ^= HF_ACT_PM;

	if (!(hflags & HF_ACT_PM)) {
		pm  = &cp->phys.pm0;
		dp_scr = SCRIPTA_BA(np, pm0_data);
	}
	else {
		pm = &cp->phys.pm1;
		dp_scr = SCRIPTA_BA(np, pm1_data);
	}

	hflags &= ~(HF_DP_SAVED);

	OUTB(np, HF_PRT, hflags);

	/*
	 *  Set up the new current data pointer.
	 *  ofs < 0 there, and for the next data phase, we 
	 *  want to transfer part of the data of the sg entry 
	 *  corresponding to index dp_sg-1 prior to returning 
	 *  to the main data script.
	 */
	pm->ret = cpu_to_scr(dp_ret);
	tmp  = scr_to_cpu(cp->phys.data[dp_sg-1].addr);
	tmp += scr_to_cpu(cp->phys.data[dp_sg-1].size) + dp_ofs;
	pm->sg.addr = cpu_to_scr(tmp);
	pm->sg.size = cpu_to_scr(-dp_ofs);

out_ok:
	sym_set_script_dp (np, cp, dp_scr);
	OUTL_DSP(np, SCRIPTA_BA(np, clrack));
	return;

out_reject:
	OUTL_DSP(np, SCRIPTB_BA(np, msg_bad));
}


/*
 *  chip calculation of the data residual.
 *
 *  As I used to say, the requirement of data residual 
 *  in SCSI is broken, useless and cannot be achieved 
 *  without huge complexity.
 *  But most OSes and even the official CAM require it.
 *  When stupidity happens to be so widely spread inside 
 *  a community, it gets hard to convince.
 *
 *  Anyway, I don't care, since I am not going to use 
 *  any software that considers this data residual as 
 *  a relevant information. :)
 */

int sym_compute_residual(struct sym_hcb *np, struct sym_ccb *cp)
{
	int dp_sg, dp_sgmin, resid = 0;
	int dp_ofs = 0;

	/*
	 *  Check for some data lost or just thrown away.
	 *  We are not required to be quite accurate in this 
	 *  situation. Btw, if we are odd for output and the 
	 *  device claims some more data, it may well happen 
	 *  than our residual be zero. :-)
	 */
	if (cp->xerr_status & (XE_EXTRA_DATA|XE_SODL_UNRUN|XE_SWIDE_OVRUN)) {
		if (cp->xerr_status & XE_EXTRA_DATA)
			resid -= cp->extra_bytes;
		if (cp->xerr_status & XE_SODL_UNRUN)
			++resid;
		if (cp->xerr_status & XE_SWIDE_OVRUN)
			--resid;
	}

	/*
	 *  If all data has been transferred,
	 *  there is no residual.
	 */
	if (cp->phys.head.lastp == cp->goalp)
		return resid;

	/*
	 *  If no data transfer occurs, or if the data
	 *  pointer is weird, return full residual.
	 */
	if (cp->startp == cp->phys.head.lastp ||
	    sym_evaluate_dp(np, cp, scr_to_cpu(cp->phys.head.lastp),
			    &dp_ofs) < 0) {
		return cp->data_len - cp->odd_byte_adjustment;
	}

	/*
	 *  If we were auto-sensing, then we are done.
	 */
	if (cp->host_flags & HF_SENSE) {
		return -dp_ofs;
	}

	/*
	 *  We are now full comfortable in the computation 
	 *  of the data residual (2's complement).
	 */
	dp_sgmin = SYM_CONF_MAX_SG - cp->segments;
	resid = -cp->ext_ofs;
	for (dp_sg = cp->ext_sg; dp_sg < SYM_CONF_MAX_SG; ++dp_sg) {
		u_int tmp = scr_to_cpu(cp->phys.data[dp_sg].size);
		resid += (tmp & 0xffffff);
	}

	resid -= cp->odd_byte_adjustment;

	/*
	 *  Hopefully, the result is not too wrong.
	 */
	return resid;
}

/*
 *  Negotiation for WIDE and SYNCHRONOUS DATA TRANSFER.
 *
 *  When we try to negotiate, we append the negotiation message
 *  to the identify and (maybe) simple tag message.
 *  The host status field is set to HS_NEGOTIATE to mark this
 *  situation.
 *
 *  If the target doesn't answer this message immediately
 *  (as required by the standard), the SIR_NEGO_FAILED interrupt
 *  will be raised eventually.
 *  The handler removes the HS_NEGOTIATE status, and sets the
 *  negotiated value to the default (async / nowide).
 *
 *  If we receive a matching answer immediately, we check it
 *  for validity, and set the values.
 *
 *  If we receive a Reject message immediately, we assume the
 *  negotiation has failed, and fall back to standard values.
 *
 *  If we receive a negotiation message while not in HS_NEGOTIATE
 *  state, it's a target initiated negotiation. We prepare a
 *  (hopefully) valid answer, set our parameters, and send back 
 *  this answer to the target.
 *
 *  If the target doesn't fetch the answer (no message out phase),
 *  we assume the negotiation has failed, and fall back to default
 *  settings (SIR_NEGO_PROTO interrupt).
 *
 *  When we set the values, we adjust them in all ccbs belonging 
 *  to this target, in the controller's register, and in the "phys"
 *  field of the controller's struct sym_hcb.
 */

/*
 *  chip handler for SYNCHRONOUS DATA TRANSFER REQUEST (SDTR) message.
 */
static int  
sym_sync_nego_check(struct sym_hcb *np, int req, struct sym_ccb *cp)
{
	int target = cp->target;
	u_char	chg, ofs, per, fak, div;

	if (DEBUG_FLAGS & DEBUG_NEGO) {
		sym_print_nego_msg(np, target, "sync msgin", np->msgin);
	}

	/*
	 *  Get requested values.
	 */
	chg = 0;
	per = np->msgin[3];
	ofs = np->msgin[4];

	/*
	 *  Check values against our limits.
	 */
	if (ofs) {
		if (ofs > np->maxoffs)
			{chg = 1; ofs = np->maxoffs;}
	}

	if (ofs) {
		if (per < np->minsync)
			{chg = 1; per = np->minsync;}
	}

	/*
	 *  Get new chip synchronous parameters value.
	 */
	div = fak = 0;
	if (ofs && sym_getsync(np, 0, per, &div, &fak) < 0)
		goto reject_it;

	if (DEBUG_FLAGS & DEBUG_NEGO) {
		sym_print_addr(cp->cmd,
				"sdtr: ofs=%d per=%d div=%d fak=%d chg=%d.\n",
				ofs, per, div, fak, chg);
	}

	/*
	 *  If it was an answer we want to change, 
	 *  then it isn't acceptable. Reject it.
	 */
	if (!req && chg)
		goto reject_it;

	/*
	 *  Apply new values.
	 */
	sym_setsync (np, target, ofs, per, div, fak);

	/*
	 *  It was an answer. We are done.
	 */
	if (!req)
		return 0;

	/*
	 *  It was a request. Prepare an answer message.
	 */
	spi_populate_sync_msg(np->msgout, per, ofs);

	if (DEBUG_FLAGS & DEBUG_NEGO) {
		sym_print_nego_msg(np, target, "sync msgout", np->msgout);
	}

	np->msgin [0] = M_NOOP;

	return 0;

reject_it:
	sym_setsync (np, target, 0, 0, 0, 0);
	return -1;
}

static void sym_sync_nego(struct sym_hcb *np, struct sym_tcb *tp, struct sym_ccb *cp)
{
	int req = 1;
	int result;

	/*
	 *  Request or answer ?
	 */
	if (INB(np, HS_PRT) == HS_NEGOTIATE) {
		OUTB(np, HS_PRT, HS_BUSY);
		if (cp->nego_status && cp->nego_status != NS_SYNC)
			goto reject_it;
		req = 0;
	}

	/*
	 *  Check and apply new values.
	 */
	result = sym_sync_nego_check(np, req, cp);
	if (result)	/* Not acceptable, reject it */
		goto reject_it;
	if (req) {	/* Was a request, send response. */
		cp->nego_status = NS_SYNC;
		OUTL_DSP(np, SCRIPTB_BA(np, sdtr_resp));
	}
	else		/* Was a response, we are done. */
		OUTL_DSP(np, SCRIPTA_BA(np, clrack));
	return;

reject_it:
	OUTL_DSP(np, SCRIPTB_BA(np, msg_bad));
}

/*
 *  chip handler for PARALLEL PROTOCOL REQUEST (PPR) message.
 */
static int 
sym_ppr_nego_check(struct sym_hcb *np, int req, int target)
{
	struct sym_tcb *tp = &np->target[target];
	unsigned char fak, div;
	int dt, chg = 0;

	unsigned char per = np->msgin[3];
	unsigned char ofs = np->msgin[5];
	unsigned char wide = np->msgin[6];
	unsigned char opts = np->msgin[7] & PPR_OPT_MASK;

	if (DEBUG_FLAGS & DEBUG_NEGO) {
		sym_print_nego_msg(np, target, "ppr msgin", np->msgin);
	}

	/*
	 *  Check values against our limits.
	 */
	if (wide > np->maxwide) {
		chg = 1;
		wide = np->maxwide;
	}
	if (!wide || !(np->features & FE_U3EN))
		opts = 0;

	if (opts != (np->msgin[7] & PPR_OPT_MASK))
		chg = 1;

	dt = opts & PPR_OPT_DT;

	if (ofs) {
		unsigned char maxoffs = dt ? np->maxoffs_dt : np->maxoffs;
		if (ofs > maxoffs) {
			chg = 1;
			ofs = maxoffs;
		}
	}

	if (ofs) {
		unsigned char minsync = dt ? np->minsync_dt : np->minsync;
		if (per < minsync) {
			chg = 1;
			per = minsync;
		}
	}

	/*
	 *  Get new chip synchronous parameters value.
	 */
	div = fak = 0;
	if (ofs && sym_getsync(np, dt, per, &div, &fak) < 0)
		goto reject_it;

	/*
	 *  If it was an answer we want to change, 
	 *  then it isn't acceptable. Reject it.
	 */
	if (!req && chg)
		goto reject_it;

	/*
	 *  Apply new values.
	 */
	sym_setpprot(np, target, opts, ofs, per, wide, div, fak);

	/*
	 *  It was an answer. We are done.
	 */
	if (!req)
		return 0;

	/*
	 *  It was a request. Prepare an answer message.
	 */
	spi_populate_ppr_msg(np->msgout, per, ofs, wide, opts);

	if (DEBUG_FLAGS & DEBUG_NEGO) {
		sym_print_nego_msg(np, target, "ppr msgout", np->msgout);
	}

	np->msgin [0] = M_NOOP;

	return 0;

reject_it:
	sym_setpprot (np, target, 0, 0, 0, 0, 0, 0);
	/*
	 *  If it is a device response that should result in  
	 *  ST, we may want to try a legacy negotiation later.
	 */
	if (!req && !opts) {
		tp->tgoal.period = per;
		tp->tgoal.offset = ofs;
		tp->tgoal.width = wide;
		tp->tgoal.iu = tp->tgoal.dt = tp->tgoal.qas = 0;
		tp->tgoal.check_nego = 1;
	}
	return -1;
}

static void sym_ppr_nego(struct sym_hcb *np, struct sym_tcb *tp, struct sym_ccb *cp)
{
	int req = 1;
	int result;

	/*
	 *  Request or answer ?
	 */
	if (INB(np, HS_PRT) == HS_NEGOTIATE) {
		OUTB(np, HS_PRT, HS_BUSY);
		if (cp->nego_status && cp->nego_status != NS_PPR)
			goto reject_it;
		req = 0;
	}

	/*
	 *  Check and apply new values.
	 */
	result = sym_ppr_nego_check(np, req, cp->target);
	if (result)	/* Not acceptable, reject it */
		goto reject_it;
	if (req) {	/* Was a request, send response. */
		cp->nego_status = NS_PPR;
		OUTL_DSP(np, SCRIPTB_BA(np, ppr_resp));
	}
	else		/* Was a response, we are done. */
		OUTL_DSP(np, SCRIPTA_BA(np, clrack));
	return;

reject_it:
	OUTL_DSP(np, SCRIPTB_BA(np, msg_bad));
}

/*
 *  chip handler for WIDE DATA TRANSFER REQUEST (WDTR) message.
 */
static int  
sym_wide_nego_check(struct sym_hcb *np, int req, struct sym_ccb *cp)
{
	int target = cp->target;
	u_char	chg, wide;

	if (DEBUG_FLAGS & DEBUG_NEGO) {
		sym_print_nego_msg(np, target, "wide msgin", np->msgin);
	}

	/*
	 *  Get requested values.
	 */
	chg  = 0;
	wide = np->msgin[3];

	/*
	 *  Check values against our limits.
	 */
	if (wide > np->maxwide) {
		chg = 1;
		wide = np->maxwide;
	}

	if (DEBUG_FLAGS & DEBUG_NEGO) {
		sym_print_addr(cp->cmd, "wdtr: wide=%d chg=%d.\n",
				wide, chg);
	}

	/*
	 *  If it was an answer we want to change, 
	 *  then it isn't acceptable. Reject it.
	 */
	if (!req && chg)
		goto reject_it;

	/*
	 *  Apply new values.
	 */
	sym_setwide (np, target, wide);

	/*
	 *  It was an answer. We are done.
	 */
	if (!req)
		return 0;

	/*
	 *  It was a request. Prepare an answer message.
	 */
	spi_populate_width_msg(np->msgout, wide);

	np->msgin [0] = M_NOOP;

	if (DEBUG_FLAGS & DEBUG_NEGO) {
		sym_print_nego_msg(np, target, "wide msgout", np->msgout);
	}

	return 0;

reject_it:
	return -1;
}

static void sym_wide_nego(struct sym_hcb *np, struct sym_tcb *tp, struct sym_ccb *cp)
{
	int req = 1;
	int result;

	/*
	 *  Request or answer ?
	 */
	if (INB(np, HS_PRT) == HS_NEGOTIATE) {
		OUTB(np, HS_PRT, HS_BUSY);
		if (cp->nego_status && cp->nego_status != NS_WIDE)
			goto reject_it;
		req = 0;
	}

	/*
	 *  Check and apply new values.
	 */
	result = sym_wide_nego_check(np, req, cp);
	if (result)	/* Not acceptable, reject it */
		goto reject_it;
	if (req) {	/* Was a request, send response. */
		cp->nego_status = NS_WIDE;
		OUTL_DSP(np, SCRIPTB_BA(np, wdtr_resp));
	} else {		/* Was a response. */
		/*
		 * Negotiate for SYNC immediately after WIDE response.
		 * This allows to negotiate for both WIDE and SYNC on 
		 * a single SCSI command (Suggested by Justin Gibbs).
		 */
		if (tp->tgoal.offset) {
			spi_populate_sync_msg(np->msgout, tp->tgoal.period,
					tp->tgoal.offset);

			if (DEBUG_FLAGS & DEBUG_NEGO) {
				sym_print_nego_msg(np, cp->target,
				                   "sync msgout", np->msgout);
			}

			cp->nego_status = NS_SYNC;
			OUTB(np, HS_PRT, HS_NEGOTIATE);
			OUTL_DSP(np, SCRIPTB_BA(np, sdtr_resp));
			return;
		} else
			OUTL_DSP(np, SCRIPTA_BA(np, clrack));
	}

	return;

reject_it:
	OUTL_DSP(np, SCRIPTB_BA(np, msg_bad));
}

/*
 *  Reset DT, SYNC or WIDE to default settings.
 *
 *  Called when a negotiation does not succeed either 
 *  on rejection or on protocol error.
 *
 *  A target that understands a PPR message should never 
 *  reject it, and messing with it is very unlikely.
 *  So, if a PPR makes problems, we may just want to 
 *  try a legacy negotiation later.
 */
static void sym_nego_default(struct sym_hcb *np, struct sym_tcb *tp, struct sym_ccb *cp)
{
	switch (cp->nego_status) {
	case NS_PPR:
#if 0
		sym_setpprot (np, cp->target, 0, 0, 0, 0, 0, 0);
#else
		if (tp->tgoal.period < np->minsync)
			tp->tgoal.period = np->minsync;
		if (tp->tgoal.offset > np->maxoffs)
			tp->tgoal.offset = np->maxoffs;
		tp->tgoal.iu = tp->tgoal.dt = tp->tgoal.qas = 0;
		tp->tgoal.check_nego = 1;
#endif
		break;
	case NS_SYNC:
		sym_setsync (np, cp->target, 0, 0, 0, 0);
		break;
	case NS_WIDE:
		sym_setwide (np, cp->target, 0);
		break;
	}
	np->msgin [0] = M_NOOP;
	np->msgout[0] = M_NOOP;
	cp->nego_status = 0;
}

/*
 *  chip handler for MESSAGE REJECT received in response to 
 *  PPR, WIDE or SYNCHRONOUS negotiation.
 */
static void sym_nego_rejected(struct sym_hcb *np, struct sym_tcb *tp, struct sym_ccb *cp)
{
	sym_nego_default(np, tp, cp);
	OUTB(np, HS_PRT, HS_BUSY);
}

/*
 *  chip exception handler for programmed interrupts.
 */
static void sym_int_sir(struct sym_hcb *np)
{
	u_char	num	= INB(np, nc_dsps);
	u32	dsa	= INL(np, nc_dsa);
	struct sym_ccb *cp	= sym_ccb_from_dsa(np, dsa);
	u_char	target	= INB(np, nc_sdid) & 0x0f;
	struct sym_tcb *tp	= &np->target[target];
	int	tmp;

	if (DEBUG_FLAGS & DEBUG_TINY) printf ("I#%d", num);

	switch (num) {
#if   SYM_CONF_DMA_ADDRESSING_MODE == 2
	/*
	 *  SCRIPTS tell us that we may have to update 
	 *  64 bit DMA segment registers.
	 */
	case SIR_DMAP_DIRTY:
		sym_update_dmap_regs(np);
		goto out;
#endif
	/*
	 *  Command has been completed with error condition 
	 *  or has been auto-sensed.
	 */
	case SIR_COMPLETE_ERROR:
		sym_complete_error(np, cp);
		return;
	/*
	 *  The C code is currently trying to recover from something.
	 *  Typically, user want to abort some command.
	 */
	case SIR_SCRIPT_STOPPED:
	case SIR_TARGET_SELECTED:
	case SIR_ABORT_SENT:
		sym_sir_task_recovery(np, num);
		return;
	/*
	 *  The device didn't go to MSG OUT phase after having 
	 *  been selected with ATN.  We do not want to handle that.
	 */
	case SIR_SEL_ATN_NO_MSG_OUT:
		scmd_printk(KERN_WARNING, cp->cmd,
				"No MSG OUT phase after selection with ATN\n");
		goto out_stuck;
	/*
	 *  The device didn't switch to MSG IN phase after 
	 *  having reselected the initiator.
	 */
	case SIR_RESEL_NO_MSG_IN:
		scmd_printk(KERN_WARNING, cp->cmd,
				"No MSG IN phase after reselection\n");
		goto out_stuck;
	/*
	 *  After reselection, the device sent a message that wasn't 
	 *  an IDENTIFY.
	 */
	case SIR_RESEL_NO_IDENTIFY:
		scmd_printk(KERN_WARNING, cp->cmd,
				"No IDENTIFY after reselection\n");
		goto out_stuck;
	/*
	 *  The device reselected a LUN we do not know about.
	 */
	case SIR_RESEL_BAD_LUN:
		np->msgout[0] = M_RESET;
		goto out;
	/*
	 *  The device reselected for an untagged nexus and we 
	 *  haven't any.
	 */
	case SIR_RESEL_BAD_I_T_L:
		np->msgout[0] = M_ABORT;
		goto out;
	/*
	 * The device reselected for a tagged nexus that we do not have.
	 */
	case SIR_RESEL_BAD_I_T_L_Q:
		np->msgout[0] = M_ABORT_TAG;
		goto out;
	/*
	 *  The SCRIPTS let us know that the device has grabbed 
	 *  our message and will abort the job.
	 */
	case SIR_RESEL_ABORTED:
		np->lastmsg = np->msgout[0];
		np->msgout[0] = M_NOOP;
		scmd_printk(KERN_WARNING, cp->cmd,
			"message %x sent on bad reselection\n", np->lastmsg);
		goto out;
	/*
	 *  The SCRIPTS let us know that a message has been 
	 *  successfully sent to the device.
	 */
	case SIR_MSG_OUT_DONE:
		np->lastmsg = np->msgout[0];
		np->msgout[0] = M_NOOP;
		/* Should we really care of that */
		if (np->lastmsg == M_PARITY || np->lastmsg == M_ID_ERROR) {
			if (cp) {
				cp->xerr_status &= ~XE_PARITY_ERR;
				if (!cp->xerr_status)
					OUTOFFB(np, HF_PRT, HF_EXT_ERR);
			}
		}
		goto out;
	/*
	 *  The device didn't send a GOOD SCSI status.
	 *  We may have some work to do prior to allow 
	 *  the SCRIPTS processor to continue.
	 */
	case SIR_BAD_SCSI_STATUS:
		if (!cp)
			goto out;
		sym_sir_bad_scsi_status(np, num, cp);
		return;
	/*
	 *  We are asked by the SCRIPTS to prepare a 
	 *  REJECT message.
	 */
	case SIR_REJECT_TO_SEND:
		sym_print_msg(cp, "M_REJECT to send for ", np->msgin);
		np->msgout[0] = M_REJECT;
		goto out;
	/*
	 *  We have been ODD at the end of a DATA IN 
	 *  transfer and the device didn't send a 
	 *  IGNORE WIDE RESIDUE message.
	 *  It is a data overrun condition.
	 */
	case SIR_SWIDE_OVERRUN:
		if (cp) {
			OUTONB(np, HF_PRT, HF_EXT_ERR);
			cp->xerr_status |= XE_SWIDE_OVRUN;
		}
		goto out;
	/*
	 *  We have been ODD at the end of a DATA OUT 
	 *  transfer.
	 *  It is a data underrun condition.
	 */
	case SIR_SODL_UNDERRUN:
		if (cp) {
			OUTONB(np, HF_PRT, HF_EXT_ERR);
			cp->xerr_status |= XE_SODL_UNRUN;
		}
		goto out;
	/*
	 *  The device wants us to tranfer more data than 
	 *  expected or in the wrong direction.
	 *  The number of extra bytes is in scratcha.
	 *  It is a data overrun condition.
	 */
	case SIR_DATA_OVERRUN:
		if (cp) {
			OUTONB(np, HF_PRT, HF_EXT_ERR);
			cp->xerr_status |= XE_EXTRA_DATA;
			cp->extra_bytes += INL(np, nc_scratcha);
		}
		goto out;
	/*
	 *  The device switched to an illegal phase (4/5).
	 */
	case SIR_BAD_PHASE:
		if (cp) {
			OUTONB(np, HF_PRT, HF_EXT_ERR);
			cp->xerr_status |= XE_BAD_PHASE;
		}
		goto out;
	/*
	 *  We received a message.
	 */
	case SIR_MSG_RECEIVED:
		if (!cp)
			goto out_stuck;
		switch (np->msgin [0]) {
		/*
		 *  We received an extended message.
		 *  We handle MODIFY DATA POINTER, SDTR, WDTR 
		 *  and reject all other extended messages.
		 */
		case M_EXTENDED:
			switch (np->msgin [2]) {
			case M_X_MODIFY_DP:
				if (DEBUG_FLAGS & DEBUG_POINTER)
					sym_print_msg(cp, NULL, np->msgin);
				tmp = (np->msgin[3]<<24) + (np->msgin[4]<<16) + 
				      (np->msgin[5]<<8)  + (np->msgin[6]);
				sym_modify_dp(np, tp, cp, tmp);
				return;
			case M_X_SYNC_REQ:
				sym_sync_nego(np, tp, cp);
				return;
			case M_X_PPR_REQ:
				sym_ppr_nego(np, tp, cp);
				return;
			case M_X_WIDE_REQ:
				sym_wide_nego(np, tp, cp);
				return;
			default:
				goto out_reject;
			}
			break;
		/*
		 *  We received a 1/2 byte message not handled from SCRIPTS.
		 *  We are only expecting MESSAGE REJECT and IGNORE WIDE 
		 *  RESIDUE messages that haven't been anticipated by 
		 *  SCRIPTS on SWIDE full condition. Unanticipated IGNORE 
		 *  WIDE RESIDUE messages are aliased as MODIFY DP (-1).
		 */
		case M_IGN_RESIDUE:
			if (DEBUG_FLAGS & DEBUG_POINTER)
				sym_print_msg(cp, NULL, np->msgin);
			if (cp->host_flags & HF_SENSE)
				OUTL_DSP(np, SCRIPTA_BA(np, clrack));
			else
				sym_modify_dp(np, tp, cp, -1);
			return;
		case M_REJECT:
			if (INB(np, HS_PRT) == HS_NEGOTIATE)
				sym_nego_rejected(np, tp, cp);
			else {
				sym_print_addr(cp->cmd,
					"M_REJECT received (%x:%x).\n",
					scr_to_cpu(np->lastmsg), np->msgout[0]);
			}
			goto out_clrack;
			break;
		default:
			goto out_reject;
		}
		break;
	/*
	 *  We received an unknown message.
	 *  Ignore all MSG IN phases and reject it.
	 */
	case SIR_MSG_WEIRD:
		sym_print_msg(cp, "WEIRD message received", np->msgin);
		OUTL_DSP(np, SCRIPTB_BA(np, msg_weird));
		return;
	/*
	 *  Negotiation failed.
	 *  Target does not send us the reply.
	 *  Remove the HS_NEGOTIATE status.
	 */
	case SIR_NEGO_FAILED:
		OUTB(np, HS_PRT, HS_BUSY);
	/*
	 *  Negotiation failed.
	 *  Target does not want answer message.
	 */
	case SIR_NEGO_PROTO:
		sym_nego_default(np, tp, cp);
		goto out;
	}

out:
	OUTONB_STD();
	return;
out_reject:
	OUTL_DSP(np, SCRIPTB_BA(np, msg_bad));
	return;
out_clrack:
	OUTL_DSP(np, SCRIPTA_BA(np, clrack));
	return;
out_stuck:
	return;
}

/*
 *  Acquire a control block
 */
struct sym_ccb *sym_get_ccb (struct sym_hcb *np, struct scsi_cmnd *cmd, u_char tag_order)
{
	u_char tn = cmd->device->id;
	u_char ln = cmd->device->lun;
	struct sym_tcb *tp = &np->target[tn];
	struct sym_lcb *lp = sym_lp(tp, ln);
	u_short tag = NO_TAG;
	SYM_QUEHEAD *qp;
	struct sym_ccb *cp = NULL;

	/*
	 *  Look for a free CCB
	 */
	if (sym_que_empty(&np->free_ccbq))
		sym_alloc_ccb(np);
	qp = sym_remque_head(&np->free_ccbq);
	if (!qp)
		goto out;
	cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);

	{
		/*
		 *  If we have been asked for a tagged command.
		 */
		if (tag_order) {
			/*
			 *  Debugging purpose.
			 */
#ifndef SYM_OPT_HANDLE_DEVICE_QUEUEING
			if (lp->busy_itl != 0)
				goto out_free;
#endif
			/*
			 *  Allocate resources for tags if not yet.
			 */
			if (!lp->cb_tags) {
				sym_alloc_lcb_tags(np, tn, ln);
				if (!lp->cb_tags)
					goto out_free;
			}
			/*
			 *  Get a tag for this SCSI IO and set up
			 *  the CCB bus address for reselection, 
			 *  and count it for this LUN.
			 *  Toggle reselect path to tagged.
			 */
			if (lp->busy_itlq < SYM_CONF_MAX_TASK) {
				tag = lp->cb_tags[lp->ia_tag];
				if (++lp->ia_tag == SYM_CONF_MAX_TASK)
					lp->ia_tag = 0;
				++lp->busy_itlq;
#ifndef SYM_OPT_HANDLE_DEVICE_QUEUEING
				lp->itlq_tbl[tag] = cpu_to_scr(cp->ccb_ba);
				lp->head.resel_sa =
					cpu_to_scr(SCRIPTA_BA(np, resel_tag));
#endif
#ifdef SYM_OPT_LIMIT_COMMAND_REORDERING
				cp->tags_si = lp->tags_si;
				++lp->tags_sum[cp->tags_si];
				++lp->tags_since;
#endif
			}
			else
				goto out_free;
		}
		/*
		 *  This command will not be tagged.
		 *  If we already have either a tagged or untagged 
		 *  one, refuse to overlap this untagged one.
		 */
		else {
			/*
			 *  Debugging purpose.
			 */
#ifndef SYM_OPT_HANDLE_DEVICE_QUEUEING
			if (lp->busy_itl != 0 || lp->busy_itlq != 0)
				goto out_free;
#endif
			/*
			 *  Count this nexus for this LUN.
			 *  Set up the CCB bus address for reselection.
			 *  Toggle reselect path to untagged.
			 */
			++lp->busy_itl;
#ifndef SYM_OPT_HANDLE_DEVICE_QUEUEING
			if (lp->busy_itl == 1) {
				lp->head.itl_task_sa = cpu_to_scr(cp->ccb_ba);
				lp->head.resel_sa =
				      cpu_to_scr(SCRIPTA_BA(np, resel_no_tag));
			}
			else
				goto out_free;
#endif
		}
	}
	/*
	 *  Put the CCB into the busy queue.
	 */
	sym_insque_tail(&cp->link_ccbq, &np->busy_ccbq);
#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
	if (lp) {
		sym_remque(&cp->link2_ccbq);
		sym_insque_tail(&cp->link2_ccbq, &lp->waiting_ccbq);
	}

#endif
	cp->to_abort = 0;
	cp->odd_byte_adjustment = 0;
	cp->tag	   = tag;
	cp->order  = tag_order;
	cp->target = tn;
	cp->lun    = ln;

	if (DEBUG_FLAGS & DEBUG_TAGS) {
		sym_print_addr(cmd, "ccb @%p using tag %d.\n", cp, tag);
	}

out:
	return cp;
out_free:
	sym_insque_head(&cp->link_ccbq, &np->free_ccbq);
	return NULL;
}

/*
 *  Release one control block
 */
void sym_free_ccb (struct sym_hcb *np, struct sym_ccb *cp)
{
	struct sym_tcb *tp = &np->target[cp->target];
	struct sym_lcb *lp = sym_lp(tp, cp->lun);

	if (DEBUG_FLAGS & DEBUG_TAGS) {
		sym_print_addr(cp->cmd, "ccb @%p freeing tag %d.\n",
				cp, cp->tag);
	}

	/*
	 *  If LCB available,
	 */
	if (lp) {
		/*
		 *  If tagged, release the tag, set the relect path 
		 */
		if (cp->tag != NO_TAG) {
#ifdef SYM_OPT_LIMIT_COMMAND_REORDERING
			--lp->tags_sum[cp->tags_si];
#endif
			/*
			 *  Free the tag value.
			 */
			lp->cb_tags[lp->if_tag] = cp->tag;
			if (++lp->if_tag == SYM_CONF_MAX_TASK)
				lp->if_tag = 0;
			/*
			 *  Make the reselect path invalid, 
			 *  and uncount this CCB.
			 */
			lp->itlq_tbl[cp->tag] = cpu_to_scr(np->bad_itlq_ba);
			--lp->busy_itlq;
		} else {	/* Untagged */
			/*
			 *  Make the reselect path invalid, 
			 *  and uncount this CCB.
			 */
			lp->head.itl_task_sa = cpu_to_scr(np->bad_itl_ba);
			--lp->busy_itl;
		}
		/*
		 *  If no JOB active, make the LUN reselect path invalid.
		 */
		if (lp->busy_itlq == 0 && lp->busy_itl == 0)
			lp->head.resel_sa =
				cpu_to_scr(SCRIPTB_BA(np, resel_bad_lun));
	}

	/*
	 *  We donnot queue more than 1 ccb per target 
	 *  with negotiation at any time. If this ccb was 
	 *  used for negotiation, clear this info in the tcb.
	 */
	if (cp == tp->nego_cp)
		tp->nego_cp = NULL;

#ifdef SYM_CONF_IARB_SUPPORT
	/*
	 *  If we just complete the last queued CCB,
	 *  clear this info that is no longer relevant.
	 */
	if (cp == np->last_cp)
		np->last_cp = 0;
#endif

	/*
	 *  Make this CCB available.
	 */
	cp->cmd = NULL;
	cp->host_status = HS_IDLE;
	sym_remque(&cp->link_ccbq);
	sym_insque_head(&cp->link_ccbq, &np->free_ccbq);

#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
	if (lp) {
		sym_remque(&cp->link2_ccbq);
		sym_insque_tail(&cp->link2_ccbq, &np->dummy_ccbq);
		if (cp->started) {
			if (cp->tag != NO_TAG)
				--lp->started_tags;
			else
				--lp->started_no_tag;
		}
	}
	cp->started = 0;
#endif
}

/*
 *  Allocate a CCB from memory and initialize its fixed part.
 */
static struct sym_ccb *sym_alloc_ccb(struct sym_hcb *np)
{
	struct sym_ccb *cp = NULL;
	int hcode;

	/*
	 *  Prevent from allocating more CCBs than we can 
	 *  queue to the controller.
	 */
	if (np->actccbs >= SYM_CONF_MAX_START)
		return NULL;

	/*
	 *  Allocate memory for this CCB.
	 */
	cp = sym_calloc_dma(sizeof(struct sym_ccb), "CCB");
	if (!cp)
		goto out_free;

	/*
	 *  Count it.
	 */
	np->actccbs++;

	/*
	 *  Compute the bus address of this ccb.
	 */
	cp->ccb_ba = vtobus(cp);

	/*
	 *  Insert this ccb into the hashed list.
	 */
	hcode = CCB_HASH_CODE(cp->ccb_ba);
	cp->link_ccbh = np->ccbh[hcode];
	np->ccbh[hcode] = cp;

	/*
	 *  Initialyze the start and restart actions.
	 */
	cp->phys.head.go.start   = cpu_to_scr(SCRIPTA_BA(np, idle));
	cp->phys.head.go.restart = cpu_to_scr(SCRIPTB_BA(np, bad_i_t_l));

 	/*
	 *  Initilialyze some other fields.
	 */
	cp->phys.smsg_ext.addr = cpu_to_scr(HCB_BA(np, msgin[2]));

	/*
	 *  Chain into free ccb queue.
	 */
	sym_insque_head(&cp->link_ccbq, &np->free_ccbq);

	/*
	 *  Chain into optionnal lists.
	 */
#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
	sym_insque_head(&cp->link2_ccbq, &np->dummy_ccbq);
#endif
	return cp;
out_free:
	if (cp)
		sym_mfree_dma(cp, sizeof(*cp), "CCB");
	return NULL;
}

/*
 *  Look up a CCB from a DSA value.
 */
static struct sym_ccb *sym_ccb_from_dsa(struct sym_hcb *np, u32 dsa)
{
	int hcode;
	struct sym_ccb *cp;

	hcode = CCB_HASH_CODE(dsa);
	cp = np->ccbh[hcode];
	while (cp) {
		if (cp->ccb_ba == dsa)
			break;
		cp = cp->link_ccbh;
	}

	return cp;
}

/*
 *  Target control block initialisation.
 *  Nothing important to do at the moment.
 */
static void sym_init_tcb (struct sym_hcb *np, u_char tn)
{
#if 0	/*  Hmmm... this checking looks paranoid. */
	/*
	 *  Check some alignments required by the chip.
	 */	
	assert (((offsetof(struct sym_reg, nc_sxfer) ^
		offsetof(struct sym_tcb, head.sval)) &3) == 0);
	assert (((offsetof(struct sym_reg, nc_scntl3) ^
		offsetof(struct sym_tcb, head.wval)) &3) == 0);
#endif
}

/*
 *  Lun control block allocation and initialization.
 */
struct sym_lcb *sym_alloc_lcb (struct sym_hcb *np, u_char tn, u_char ln)
{
	struct sym_tcb *tp = &np->target[tn];
	struct sym_lcb *lp = NULL;

	/*
	 *  Initialize the target control block if not yet.
	 */
	sym_init_tcb (np, tn);

	/*
	 *  Allocate the LCB bus address array.
	 *  Compute the bus address of this table.
	 */
	if (ln && !tp->luntbl) {
		int i;

		tp->luntbl = sym_calloc_dma(256, "LUNTBL");
		if (!tp->luntbl)
			goto fail;
		for (i = 0 ; i < 64 ; i++)
			tp->luntbl[i] = cpu_to_scr(vtobus(&np->badlun_sa));
		tp->head.luntbl_sa = cpu_to_scr(vtobus(tp->luntbl));
	}

	/*
	 *  Allocate the table of pointers for LUN(s) > 0, if needed.
	 */
	if (ln && !tp->lunmp) {
		tp->lunmp = kcalloc(SYM_CONF_MAX_LUN, sizeof(struct sym_lcb *),
				GFP_ATOMIC);
		if (!tp->lunmp)
			goto fail;
	}

	/*
	 *  Allocate the lcb.
	 *  Make it available to the chip.
	 */
	lp = sym_calloc_dma(sizeof(struct sym_lcb), "LCB");
	if (!lp)
		goto fail;
	if (ln) {
		tp->lunmp[ln] = lp;
		tp->luntbl[ln] = cpu_to_scr(vtobus(lp));
	}
	else {
		tp->lun0p = lp;
		tp->head.lun0_sa = cpu_to_scr(vtobus(lp));
	}
	tp->nlcb++;

	/*
	 *  Let the itl task point to error handling.
	 */
	lp->head.itl_task_sa = cpu_to_scr(np->bad_itl_ba);

	/*
	 *  Set the reselect pattern to our default. :)
	 */
	lp->head.resel_sa = cpu_to_scr(SCRIPTB_BA(np, resel_bad_lun));

	/*
	 *  Set user capabilities.
	 */
	lp->user_flags = tp->usrflags & (SYM_DISC_ENABLED | SYM_TAGS_ENABLED);

#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
	/*
	 *  Initialize device queueing.
	 */
	sym_que_init(&lp->waiting_ccbq);
	sym_que_init(&lp->started_ccbq);
	lp->started_max   = SYM_CONF_MAX_TASK;
	lp->started_limit = SYM_CONF_MAX_TASK;
#endif

fail:
	return lp;
}

/*
 *  Allocate LCB resources for tagged command queuing.
 */
static void sym_alloc_lcb_tags (struct sym_hcb *np, u_char tn, u_char ln)
{
	struct sym_tcb *tp = &np->target[tn];
	struct sym_lcb *lp = sym_lp(tp, ln);
	int i;

	/*
	 *  Allocate the task table and and the tag allocation 
	 *  circular buffer. We want both or none.
	 */
	lp->itlq_tbl = sym_calloc_dma(SYM_CONF_MAX_TASK*4, "ITLQ_TBL");
	if (!lp->itlq_tbl)
		goto fail;
	lp->cb_tags = kcalloc(SYM_CONF_MAX_TASK, 1, GFP_ATOMIC);
	if (!lp->cb_tags) {
		sym_mfree_dma(lp->itlq_tbl, SYM_CONF_MAX_TASK*4, "ITLQ_TBL");
		lp->itlq_tbl = NULL;
		goto fail;
	}

	/*
	 *  Initialize the task table with invalid entries.
	 */
	for (i = 0 ; i < SYM_CONF_MAX_TASK ; i++)
		lp->itlq_tbl[i] = cpu_to_scr(np->notask_ba);

	/*
	 *  Fill up the tag buffer with tag numbers.
	 */
	for (i = 0 ; i < SYM_CONF_MAX_TASK ; i++)
		lp->cb_tags[i] = i;

	/*
	 *  Make the task table available to SCRIPTS, 
	 *  And accept tagged commands now.
	 */
	lp->head.itlq_tbl_sa = cpu_to_scr(vtobus(lp->itlq_tbl));

	return;
fail:
	return;
}

/*
 *  Lun control block deallocation. Returns the number of valid remaing LCBs
 *  for the target.
 */
int sym_free_lcb(struct sym_hcb *np, u_char tn, u_char ln)
{
	struct sym_tcb *tp = &np->target[tn];
	struct sym_lcb *lp = sym_lp(tp, ln);

	tp->nlcb--;

	if (ln) {
		if (!tp->nlcb) {
			kfree(tp->lunmp);
			sym_mfree_dma(tp->luntbl, 256, "LUNTBL");
			tp->lunmp = NULL;
			tp->luntbl = NULL;
			tp->head.luntbl_sa = cpu_to_scr(vtobus(np->badluntbl));
		} else {
			tp->luntbl[ln] = cpu_to_scr(vtobus(&np->badlun_sa));
			tp->lunmp[ln] = NULL;
		}
	} else {
		tp->lun0p = NULL;
		tp->head.lun0_sa = cpu_to_scr(vtobus(&np->badlun_sa));
	}

	if (lp->itlq_tbl) {
		sym_mfree_dma(lp->itlq_tbl, SYM_CONF_MAX_TASK*4, "ITLQ_TBL");
		kfree(lp->cb_tags);
	}

	sym_mfree_dma(lp, sizeof(*lp), "LCB");

	return tp->nlcb;
}

/*
 *  Queue a SCSI IO to the controller.
 */
int sym_queue_scsiio(struct sym_hcb *np, struct scsi_cmnd *cmd, struct sym_ccb *cp)
{
	struct scsi_device *sdev = cmd->device;
	struct sym_tcb *tp;
	struct sym_lcb *lp;
	u_char	*msgptr;
	u_int   msglen;
	int can_disconnect;

	/*
	 *  Keep track of the IO in our CCB.
	 */
	cp->cmd = cmd;

	/*
	 *  Retrieve the target descriptor.
	 */
	tp = &np->target[cp->target];

	/*
	 *  Retrieve the lun descriptor.
	 */
	lp = sym_lp(tp, sdev->lun);

	can_disconnect = (cp->tag != NO_TAG) ||
		(lp && (lp->curr_flags & SYM_DISC_ENABLED));

	msgptr = cp->scsi_smsg;
	msglen = 0;
	msgptr[msglen++] = IDENTIFY(can_disconnect, sdev->lun);

	/*
	 *  Build the tag message if present.
	 */
	if (cp->tag != NO_TAG) {
		u_char order = cp->order;

		switch(order) {
		case M_ORDERED_TAG:
			break;
		case M_HEAD_TAG:
			break;
		default:
			order = M_SIMPLE_TAG;
		}
#ifdef SYM_OPT_LIMIT_COMMAND_REORDERING
		/*
		 *  Avoid too much reordering of SCSI commands.
		 *  The algorithm tries to prevent completion of any 
		 *  tagged command from being delayed against more 
		 *  than 3 times the max number of queued commands.
		 */
		if (lp && lp->tags_since > 3*SYM_CONF_MAX_TAG) {
			lp->tags_si = !(lp->tags_si);
			if (lp->tags_sum[lp->tags_si]) {
				order = M_ORDERED_TAG;
				if ((DEBUG_FLAGS & DEBUG_TAGS)||sym_verbose>1) {
					sym_print_addr(cmd,
						"ordered tag forced.\n");
				}
			}
			lp->tags_since = 0;
		}
#endif
		msgptr[msglen++] = order;

		/*
		 *  For less than 128 tags, actual tags are numbered 
		 *  1,3,5,..2*MAXTAGS+1,since we may have to deal 
		 *  with devices that have problems with #TAG 0 or too 
		 *  great #TAG numbers. For more tags (up to 256), 
		 *  we use directly our tag number.
		 */
#if SYM_CONF_MAX_TASK > (512/4)
		msgptr[msglen++] = cp->tag;
#else
		msgptr[msglen++] = (cp->tag << 1) + 1;
#endif
	}

	/*
	 *  Build a negotiation message if needed.
	 *  (nego_status is filled by sym_prepare_nego())
	 *
	 *  Always negotiate on INQUIRY and REQUEST SENSE.
	 *
	 */
	cp->nego_status = 0;
	if ((tp->tgoal.check_nego ||
	     cmd->cmnd[0] == INQUIRY || cmd->cmnd[0] == REQUEST_SENSE) &&
	    !tp->nego_cp && lp) {
		msglen += sym_prepare_nego(np, cp, msgptr + msglen);
	}

	/*
	 *  Startqueue
	 */
	cp->phys.head.go.start   = cpu_to_scr(SCRIPTA_BA(np, select));
	cp->phys.head.go.restart = cpu_to_scr(SCRIPTA_BA(np, resel_dsa));

	/*
	 *  select
	 */
	cp->phys.select.sel_id		= cp->target;
	cp->phys.select.sel_scntl3	= tp->head.wval;
	cp->phys.select.sel_sxfer	= tp->head.sval;
	cp->phys.select.sel_scntl4	= tp->head.uval;

	/*
	 *  message
	 */
	cp->phys.smsg.addr	= CCB_BA(cp, scsi_smsg);
	cp->phys.smsg.size	= cpu_to_scr(msglen);

	/*
	 *  status
	 */
	cp->host_xflags		= 0;
	cp->host_status		= cp->nego_status ? HS_NEGOTIATE : HS_BUSY;
	cp->ssss_status		= S_ILLEGAL;
	cp->xerr_status		= 0;
	cp->host_flags		= 0;
	cp->extra_bytes		= 0;

	/*
	 *  extreme data pointer.
	 *  shall be positive, so -1 is lower than lowest.:)
	 */
	cp->ext_sg  = -1;
	cp->ext_ofs = 0;

	/*
	 *  Build the CDB and DATA descriptor block 
	 *  and start the IO.
	 */
	return sym_setup_data_and_start(np, cmd, cp);
}

/*
 *  Reset a SCSI target (all LUNs of this target).
 */
int sym_reset_scsi_target(struct sym_hcb *np, int target)
{
	struct sym_tcb *tp;

	if (target == np->myaddr || (u_int)target >= SYM_CONF_MAX_TARGET)
		return -1;

	tp = &np->target[target];
	tp->to_reset = 1;

	np->istat_sem = SEM;
	OUTB(np, nc_istat, SIGP|SEM);

	return 0;
}

/*
 *  Abort a SCSI IO.
 */
static int sym_abort_ccb(struct sym_hcb *np, struct sym_ccb *cp, int timed_out)
{
	/*
	 *  Check that the IO is active.
	 */
	if (!cp || !cp->host_status || cp->host_status == HS_WAIT)
		return -1;

	/*
	 *  If a previous abort didn't succeed in time,
	 *  perform a BUS reset.
	 */
	if (cp->to_abort) {
		sym_reset_scsi_bus(np, 1);
		return 0;
	}

	/*
	 *  Mark the CCB for abort and allow time for.
	 */
	cp->to_abort = timed_out ? 2 : 1;

	/*
	 *  Tell the SCRIPTS processor to stop and synchronize with us.
	 */
	np->istat_sem = SEM;
	OUTB(np, nc_istat, SIGP|SEM);
	return 0;
}

int sym_abort_scsiio(struct sym_hcb *np, struct scsi_cmnd *cmd, int timed_out)
{
	struct sym_ccb *cp;
	SYM_QUEHEAD *qp;

	/*
	 *  Look up our CCB control block.
	 */
	cp = NULL;
	FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
		struct sym_ccb *cp2 = sym_que_entry(qp, struct sym_ccb, link_ccbq);
		if (cp2->cmd == cmd) {
			cp = cp2;
			break;
		}
	}

	return sym_abort_ccb(np, cp, timed_out);
}

/*
 *  Complete execution of a SCSI command with extended 
 *  error, SCSI status error, or having been auto-sensed.
 *
 *  The SCRIPTS processor is not running there, so we 
 *  can safely access IO registers and remove JOBs from  
 *  the START queue.
 *  SCRATCHA is assumed to have been loaded with STARTPOS 
 *  before the SCRIPTS called the C code.
 */
void sym_complete_error(struct sym_hcb *np, struct sym_ccb *cp)
{
	struct scsi_device *sdev;
	struct scsi_cmnd *cmd;
	struct sym_tcb *tp;
	struct sym_lcb *lp;
	int resid;
	int i;

	/*
	 *  Paranoid check. :)
	 */
	if (!cp || !cp->cmd)
		return;

	cmd = cp->cmd;
	sdev = cmd->device;
	if (DEBUG_FLAGS & (DEBUG_TINY|DEBUG_RESULT)) {
		dev_info(&sdev->sdev_gendev, "CCB=%p STAT=%x/%x/%x\n", cp,
			cp->host_status, cp->ssss_status, cp->host_flags);
	}

	/*
	 *  Get target and lun pointers.
	 */
	tp = &np->target[cp->target];
	lp = sym_lp(tp, sdev->lun);

	/*
	 *  Check for extended errors.
	 */
	if (cp->xerr_status) {
		if (sym_verbose)
			sym_print_xerr(cmd, cp->xerr_status);
		if (cp->host_status == HS_COMPLETE)
			cp->host_status = HS_COMP_ERR;
	}

	/*
	 *  Calculate the residual.
	 */
	resid = sym_compute_residual(np, cp);

	if (!SYM_SETUP_RESIDUAL_SUPPORT) {/* If user does not want residuals */
		resid  = 0;		 /* throw them away. :)		    */
		cp->sv_resid = 0;
	}
#ifdef DEBUG_2_0_X
if (resid)
	printf("XXXX RESID= %d - 0x%x\n", resid, resid);
#endif

	/*
	 *  Dequeue all queued CCBs for that device 
	 *  not yet started by SCRIPTS.
	 */
	i = (INL(np, nc_scratcha) - np->squeue_ba) / 4;
	i = sym_dequeue_from_squeue(np, i, cp->target, sdev->lun, -1);

	/*
	 *  Restart the SCRIPTS processor.
	 */
	OUTL_DSP(np, SCRIPTA_BA(np, start));

#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
	if (cp->host_status == HS_COMPLETE &&
	    cp->ssss_status == S_QUEUE_FULL) {
		if (!lp || lp->started_tags - i < 2)
			goto weirdness;
		/*
		 *  Decrease queue depth as needed.
		 */
		lp->started_max = lp->started_tags - i - 1;
		lp->num_sgood = 0;

		if (sym_verbose >= 2) {
			sym_print_addr(cmd, " queue depth is now %d\n",
					lp->started_max);
		}

		/*
		 *  Repair the CCB.
		 */
		cp->host_status = HS_BUSY;
		cp->ssss_status = S_ILLEGAL;

		/*
		 *  Let's requeue it to device.
		 */
		sym_set_cam_status(cmd, DID_SOFT_ERROR);
		goto finish;
	}
weirdness:
#endif
	/*
	 *  Build result in CAM ccb.
	 */
	sym_set_cam_result_error(np, cp, resid);

#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
finish:
#endif
	/*
	 *  Add this one to the COMP queue.
	 */
	sym_remque(&cp->link_ccbq);
	sym_insque_head(&cp->link_ccbq, &np->comp_ccbq);

	/*
	 *  Complete all those commands with either error 
	 *  or requeue condition.
	 */
	sym_flush_comp_queue(np, 0);

#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
	/*
	 *  Donnot start more than 1 command after an error.
	 */
	sym_start_next_ccbs(np, lp, 1);
#endif
}

/*
 *  Complete execution of a successful SCSI command.
 *
 *  Only successful commands go to the DONE queue, 
 *  since we need to have the SCRIPTS processor 
 *  stopped on any error condition.
 *  The SCRIPTS processor is running while we are 
 *  completing successful commands.
 */
void sym_complete_ok (struct sym_hcb *np, struct sym_ccb *cp)
{
	struct sym_tcb *tp;
	struct sym_lcb *lp;
	struct scsi_cmnd *cmd;
	int resid;

	/*
	 *  Paranoid check. :)
	 */
	if (!cp || !cp->cmd)
		return;
	assert (cp->host_status == HS_COMPLETE);

	/*
	 *  Get user command.
	 */
	cmd = cp->cmd;

	/*
	 *  Get target and lun pointers.
	 */
	tp = &np->target[cp->target];
	lp = sym_lp(tp, cp->lun);

	/*
	 *  If all data have been transferred, given than no
	 *  extended error did occur, there is no residual.
	 */
	resid = 0;
	if (cp->phys.head.lastp != cp->goalp)
		resid = sym_compute_residual(np, cp);

	/*
	 *  Wrong transfer residuals may be worse than just always 
	 *  returning zero. User can disable this feature in 
	 *  sym53c8xx.h. Residual support is enabled by default.
	 */
	if (!SYM_SETUP_RESIDUAL_SUPPORT)
		resid  = 0;
#ifdef DEBUG_2_0_X
if (resid)
	printf("XXXX RESID= %d - 0x%x\n", resid, resid);
#endif

	/*
	 *  Build result in CAM ccb.
	 */
	sym_set_cam_result_ok(cp, cmd, resid);

#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
	/*
	 *  If max number of started ccbs had been reduced,
	 *  increase it if 200 good status received.
	 */
	if (lp && lp->started_max < lp->started_limit) {
		++lp->num_sgood;
		if (lp->num_sgood >= 200) {
			lp->num_sgood = 0;
			++lp->started_max;
			if (sym_verbose >= 2) {
				sym_print_addr(cmd, " queue depth is now %d\n",
				       lp->started_max);
			}
		}
	}
#endif

	/*
	 *  Free our CCB.
	 */
	sym_free_ccb (np, cp);

#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
	/*
	 *  Requeue a couple of awaiting scsi commands.
	 */
	if (!sym_que_empty(&lp->waiting_ccbq))
		sym_start_next_ccbs(np, lp, 2);
#endif
	/*
	 *  Complete the command.
	 */
	sym_xpt_done(np, cmd);
}

/*
 *  Soft-attach the controller.
 */
int sym_hcb_attach(struct Scsi_Host *shost, struct sym_fw *fw, struct sym_nvram *nvram)
{
	struct sym_hcb *np = sym_get_hcb(shost);
	int i;

	/*
	 *  Get some info about the firmware.
	 */
	np->scripta_sz	 = fw->a_size;
	np->scriptb_sz	 = fw->b_size;
	np->scriptz_sz	 = fw->z_size;
	np->fw_setup	 = fw->setup;
	np->fw_patch	 = fw->patch;
	np->fw_name	 = fw->name;

	/*
	 *  Save setting of some IO registers, so we will 
	 *  be able to probe specific implementations.
	 */
	sym_save_initial_setting (np);

	/*
	 *  Reset the chip now, since it has been reported 
	 *  that SCSI clock calibration may not work properly 
	 *  if the chip is currently active.
	 */
	sym_chip_reset(np);

	/*
	 *  Prepare controller and devices settings, according 
	 *  to chip features, user set-up and driver set-up.
	 */
	sym_prepare_setting(shost, np, nvram);

	/*
	 *  Check the PCI clock frequency.
	 *  Must be performed after prepare_setting since it destroys 
	 *  STEST1 that is used to probe for the clock doubler.
	 */
	i = sym_getpciclock(np);
	if (i > 37000 && !(np->features & FE_66MHZ))
		printf("%s: PCI BUS clock seems too high: %u KHz.\n",
			sym_name(np), i);

	/*
	 *  Allocate the start queue.
	 */
	np->squeue = sym_calloc_dma(sizeof(u32)*(MAX_QUEUE*2),"SQUEUE");
	if (!np->squeue)
		goto attach_failed;
	np->squeue_ba = vtobus(np->squeue);

	/*
	 *  Allocate the done queue.
	 */
	np->dqueue = sym_calloc_dma(sizeof(u32)*(MAX_QUEUE*2),"DQUEUE");
	if (!np->dqueue)
		goto attach_failed;
	np->dqueue_ba = vtobus(np->dqueue);

	/*
	 *  Allocate the target bus address array.
	 */
	np->targtbl = sym_calloc_dma(256, "TARGTBL");
	if (!np->targtbl)
		goto attach_failed;
	np->targtbl_ba = vtobus(np->targtbl);

	/*
	 *  Allocate SCRIPTS areas.
	 */
	np->scripta0 = sym_calloc_dma(np->scripta_sz, "SCRIPTA0");
	np->scriptb0 = sym_calloc_dma(np->scriptb_sz, "SCRIPTB0");
	np->scriptz0 = sym_calloc_dma(np->scriptz_sz, "SCRIPTZ0");
	if (!np->scripta0 || !np->scriptb0 || !np->scriptz0)
		goto attach_failed;

	/*
	 *  Allocate the array of lists of CCBs hashed by DSA.
	 */
	np->ccbh = kcalloc(CCB_HASH_SIZE, sizeof(struct sym_ccb **), GFP_KERNEL);
	if (!np->ccbh)
		goto attach_failed;

	/*
	 *  Initialyze the CCB free and busy queues.
	 */
	sym_que_init(&np->free_ccbq);
	sym_que_init(&np->busy_ccbq);
	sym_que_init(&np->comp_ccbq);

	/*
	 *  Initialization for optional handling 
	 *  of device queueing.
	 */
#ifdef SYM_OPT_HANDLE_DEVICE_QUEUEING
	sym_que_init(&np->dummy_ccbq);
#endif
	/*
	 *  Allocate some CCB. We need at least ONE.
	 */
	if (!sym_alloc_ccb(np))
		goto attach_failed;

	/*
	 *  Calculate BUS addresses where we are going 
	 *  to load the SCRIPTS.
	 */
	np->scripta_ba	= vtobus(np->scripta0);
	np->scriptb_ba	= vtobus(np->scriptb0);
	np->scriptz_ba	= vtobus(np->scriptz0);

	if (np->ram_ba) {
		np->scripta_ba = np->ram_ba;
		if (np->features & FE_RAM8K) {
			np->scriptb_ba = np->scripta_ba + 4096;
#if 0	/* May get useful for 64 BIT PCI addressing */
			np->scr_ram_seg = cpu_to_scr(np->scripta_ba >> 32);
#endif
		}
	}

	/*
	 *  Copy scripts to controller instance.
	 */
	memcpy(np->scripta0, fw->a_base, np->scripta_sz);
	memcpy(np->scriptb0, fw->b_base, np->scriptb_sz);
	memcpy(np->scriptz0, fw->z_base, np->scriptz_sz);

	/*
	 *  Setup variable parts in scripts and compute
	 *  scripts bus addresses used from the C code.
	 */
	np->fw_setup(np, fw);

	/*
	 *  Bind SCRIPTS with physical addresses usable by the 
	 *  SCRIPTS processor (as seen from the BUS = BUS addresses).
	 */
	sym_fw_bind_script(np, (u32 *) np->scripta0, np->scripta_sz);
	sym_fw_bind_script(np, (u32 *) np->scriptb0, np->scriptb_sz);
	sym_fw_bind_script(np, (u32 *) np->scriptz0, np->scriptz_sz);

#ifdef SYM_CONF_IARB_SUPPORT
	/*
	 *    If user wants IARB to be set when we win arbitration 
	 *    and have other jobs, compute the max number of consecutive 
	 *    settings of IARB hints before we leave devices a chance to 
	 *    arbitrate for reselection.
	 */
#ifdef	SYM_SETUP_IARB_MAX
	np->iarb_max = SYM_SETUP_IARB_MAX;
#else
	np->iarb_max = 4;
#endif
#endif

	/*
	 *  Prepare the idle and invalid task actions.
	 */
	np->idletask.start	= cpu_to_scr(SCRIPTA_BA(np, idle));
	np->idletask.restart	= cpu_to_scr(SCRIPTB_BA(np, bad_i_t_l));
	np->idletask_ba		= vtobus(&np->idletask);

	np->notask.start	= cpu_to_scr(SCRIPTA_BA(np, idle));
	np->notask.restart	= cpu_to_scr(SCRIPTB_BA(np, bad_i_t_l));
	np->notask_ba		= vtobus(&np->notask);

	np->bad_itl.start	= cpu_to_scr(SCRIPTA_BA(np, idle));
	np->bad_itl.restart	= cpu_to_scr(SCRIPTB_BA(np, bad_i_t_l));
	np->bad_itl_ba		= vtobus(&np->bad_itl);

	np->bad_itlq.start	= cpu_to_scr(SCRIPTA_BA(np, idle));
	np->bad_itlq.restart	= cpu_to_scr(SCRIPTB_BA(np,bad_i_t_l_q));
	np->bad_itlq_ba		= vtobus(&np->bad_itlq);

	/*
	 *  Allocate and prepare the lun JUMP table that is used 
	 *  for a target prior the probing of devices (bad lun table).
	 *  A private table will be allocated for the target on the 
	 *  first INQUIRY response received.
	 */
	np->badluntbl = sym_calloc_dma(256, "BADLUNTBL");
	if (!np->badluntbl)
		goto attach_failed;

	np->badlun_sa = cpu_to_scr(SCRIPTB_BA(np, resel_bad_lun));
	for (i = 0 ; i < 64 ; i++)	/* 64 luns/target, no less */
		np->badluntbl[i] = cpu_to_scr(vtobus(&np->badlun_sa));

	/*
	 *  Prepare the bus address array that contains the bus 
	 *  address of each target control block.
	 *  For now, assume all logical units are wrong. :)
	 */
	for (i = 0 ; i < SYM_CONF_MAX_TARGET ; i++) {
		np->targtbl[i] = cpu_to_scr(vtobus(&np->target[i]));
		np->target[i].head.luntbl_sa =
				cpu_to_scr(vtobus(np->badluntbl));
		np->target[i].head.lun0_sa =
				cpu_to_scr(vtobus(&np->badlun_sa));
	}

	/*
	 *  Now check the cache handling of the pci chipset.
	 */
	if (sym_snooptest (np)) {
		printf("%s: CACHE INCORRECTLY CONFIGURED.\n", sym_name(np));
		goto attach_failed;
	}

	/*
	 *  Sigh! we are done.
	 */
	return 0;

attach_failed:
	return -ENXIO;
}

/*
 *  Free everything that has been allocated for this device.
 */
void sym_hcb_free(struct sym_hcb *np)
{
	SYM_QUEHEAD *qp;
	struct sym_ccb *cp;
	struct sym_tcb *tp;
	int target;

	if (np->scriptz0)
		sym_mfree_dma(np->scriptz0, np->scriptz_sz, "SCRIPTZ0");
	if (np->scriptb0)
		sym_mfree_dma(np->scriptb0, np->scriptb_sz, "SCRIPTB0");
	if (np->scripta0)
		sym_mfree_dma(np->scripta0, np->scripta_sz, "SCRIPTA0");
	if (np->squeue)
		sym_mfree_dma(np->squeue, sizeof(u32)*(MAX_QUEUE*2), "SQUEUE");
	if (np->dqueue)
		sym_mfree_dma(np->dqueue, sizeof(u32)*(MAX_QUEUE*2), "DQUEUE");

	if (np->actccbs) {
		while ((qp = sym_remque_head(&np->free_ccbq)) != NULL) {
			cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
			sym_mfree_dma(cp, sizeof(*cp), "CCB");
		}
	}
	kfree(np->ccbh);

	if (np->badluntbl)
		sym_mfree_dma(np->badluntbl, 256,"BADLUNTBL");

	for (target = 0; target < SYM_CONF_MAX_TARGET ; target++) {
		tp = &np->target[target];
		if (tp->luntbl)
			sym_mfree_dma(tp->luntbl, 256, "LUNTBL");
#if SYM_CONF_MAX_LUN > 1
		kfree(tp->lunmp);
#endif 
	}
	if (np->targtbl)
		sym_mfree_dma(np->targtbl, 256, "TARGTBL");
}