Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
[linux-2.6.git] / drivers / scsi / NCR5380.c
1 /* 
2  * NCR 5380 generic driver routines.  These should make it *trivial*
3  *      to implement 5380 SCSI drivers under Linux with a non-trantor
4  *      architecture.
5  *
6  *      Note that these routines also work with NR53c400 family chips.
7  *
8  * Copyright 1993, Drew Eckhardt
9  *      Visionary Computing 
10  *      (Unix and Linux consulting and custom programming)
11  *      drew@colorado.edu
12  *      +1 (303) 666-5836
13  *
14  * DISTRIBUTION RELEASE 6. 
15  *
16  * For more information, please consult 
17  *
18  * NCR 5380 Family
19  * SCSI Protocol Controller
20  * Databook
21  *
22  * NCR Microelectronics
23  * 1635 Aeroplaza Drive
24  * Colorado Springs, CO 80916
25  * 1+ (719) 578-3400
26  * 1+ (800) 334-5454
27  */
28
29 /*
30  * $Log: NCR5380.c,v $
31
32  * Revision 1.10 1998/9/2       Alan Cox
33  *                              (alan@redhat.com)
34  * Fixed up the timer lockups reported so far. Things still suck. Looking 
35  * forward to 2.3 and per device request queues. Then it'll be possible to
36  * SMP thread this beast and improve life no end.
37  
38  * Revision 1.9  1997/7/27      Ronald van Cuijlenborg
39  *                              (ronald.van.cuijlenborg@tip.nl or nutty@dds.nl)
40  * (hopefully) fixed and enhanced USLEEP
41  * added support for DTC3181E card (for Mustek scanner)
42  *
43
44  * Revision 1.8                 Ingmar Baumgart
45  *                              (ingmar@gonzo.schwaben.de)
46  * added support for NCR53C400a card
47  *
48
49  * Revision 1.7  1996/3/2       Ray Van Tassle (rayvt@comm.mot.com)
50  * added proc_info
51  * added support needed for DTC 3180/3280
52  * fixed a couple of bugs
53  *
54
55  * Revision 1.5  1994/01/19  09:14:57  drew
56  * Fixed udelay() hack that was being used on DATAOUT phases
57  * instead of a proper wait for the final handshake.
58  *
59  * Revision 1.4  1994/01/19  06:44:25  drew
60  * *** empty log message ***
61  *
62  * Revision 1.3  1994/01/19  05:24:40  drew
63  * Added support for TCR LAST_BYTE_SENT bit.
64  *
65  * Revision 1.2  1994/01/15  06:14:11  drew
66  * REAL DMA support, bug fixes.
67  *
68  * Revision 1.1  1994/01/15  06:00:54  drew
69  * Initial revision
70  *
71  */
72
73 /*
74  * Further development / testing that should be done : 
75  * 1.  Cleanup the NCR5380_transfer_dma function and DMA operation complete
76  *     code so that everything does the same thing that's done at the 
77  *     end of a pseudo-DMA read operation.
78  *
79  * 2.  Fix REAL_DMA (interrupt driven, polled works fine) -
80  *     basically, transfer size needs to be reduced by one 
81  *     and the last byte read as is done with PSEUDO_DMA.
82  * 
83  * 4.  Test SCSI-II tagged queueing (I have no devices which support 
84  *      tagged queueing)
85  *
86  * 5.  Test linked command handling code after Eric is ready with 
87  *      the high level code.
88  */
89 #include <scsi/scsi_dbg.h>
90 #include <scsi/scsi_transport_spi.h>
91
92 #ifndef NDEBUG
93 #define NDEBUG 0
94 #endif
95 #ifndef NDEBUG_ABORT
96 #define NDEBUG_ABORT 0
97 #endif
98
99 #if (NDEBUG & NDEBUG_LISTS)
100 #define LIST(x,y) {printk("LINE:%d   Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); if ((x)==(y)) udelay(5); }
101 #define REMOVE(w,x,y,z) {printk("LINE:%d   Removing: %p->%p  %p->%p \n", __LINE__, (void*)(w), (void*)(x), (void*)(y), (void*)(z)); if ((x)==(y)) udelay(5); }
102 #else
103 #define LIST(x,y)
104 #define REMOVE(w,x,y,z)
105 #endif
106
107 #ifndef notyet
108 #undef LINKED
109 #undef REAL_DMA
110 #endif
111
112 #ifdef REAL_DMA_POLL
113 #undef READ_OVERRUNS
114 #define READ_OVERRUNS
115 #endif
116
117 #ifdef BOARD_REQUIRES_NO_DELAY
118 #define io_recovery_delay(x)
119 #else
120 #define io_recovery_delay(x)    udelay(x)
121 #endif
122
123 /*
124  * Design
125  *
126  * This is a generic 5380 driver.  To use it on a different platform, 
127  * one simply writes appropriate system specific macros (ie, data
128  * transfer - some PC's will use the I/O bus, 68K's must use 
129  * memory mapped) and drops this file in their 'C' wrapper.
130  *
131  * (Note from hch:  unfortunately it was not enough for the different
132  * m68k folks and instead of improving this driver they copied it
133  * and hacked it up for their needs.  As a consequence they lost
134  * most updates to this driver.  Maybe someone will fix all these
135  * drivers to use a common core one day..)
136  *
137  * As far as command queueing, two queues are maintained for 
138  * each 5380 in the system - commands that haven't been issued yet,
139  * and commands that are currently executing.  This means that an 
140  * unlimited number of commands may be queued, letting 
141  * more commands propagate from the higher driver levels giving higher 
142  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported, 
143  * allowing multiple commands to propagate all the way to a SCSI-II device 
144  * while a command is already executing.
145  *
146  *
147  * Issues specific to the NCR5380 : 
148  *
149  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead 
150  * piece of hardware that requires you to sit in a loop polling for 
151  * the REQ signal as long as you are connected.  Some devices are 
152  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect 
153  * while doing long seek operations.
154  * 
155  * The workaround for this is to keep track of devices that have
156  * disconnected.  If the device hasn't disconnected, for commands that
157  * should disconnect, we do something like 
158  *
159  * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
160  * 
161  * Some tweaking of N and M needs to be done.  An algorithm based 
162  * on "time to data" would give the best results as long as short time
163  * to datas (ie, on the same track) were considered, however these 
164  * broken devices are the exception rather than the rule and I'd rather
165  * spend my time optimizing for the normal case.
166  *
167  * Architecture :
168  *
169  * At the heart of the design is a coroutine, NCR5380_main,
170  * which is started from a workqueue for each NCR5380 host in the
171  * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
172  * removing the commands from the issue queue and calling
173  * NCR5380_select() if a nexus is not established. 
174  *
175  * Once a nexus is established, the NCR5380_information_transfer()
176  * phase goes through the various phases as instructed by the target.
177  * if the target goes into MSG IN and sends a DISCONNECT message,
178  * the command structure is placed into the per instance disconnected
179  * queue, and NCR5380_main tries to find more work.  If the target is 
180  * idle for too long, the system will try to sleep.
181  *
182  * If a command has disconnected, eventually an interrupt will trigger,
183  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
184  * to reestablish a nexus.  This will run main if necessary.
185  *
186  * On command termination, the done function will be called as 
187  * appropriate.
188  *
189  * SCSI pointers are maintained in the SCp field of SCSI command 
190  * structures, being initialized after the command is connected
191  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
192  * Note that in violation of the standard, an implicit SAVE POINTERS operation
193  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
194  */
195
196 /*
197  * Using this file :
198  * This file a skeleton Linux SCSI driver for the NCR 5380 series
199  * of chips.  To use it, you write an architecture specific functions 
200  * and macros and include this file in your driver.
201  *
202  * These macros control options : 
203  * AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be 
204  *      defined.
205  * 
206  * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
207  *      for commands that return with a CHECK CONDITION status. 
208  *
209  * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
210  *      transceivers. 
211  *
212  * DONT_USE_INTR - if defined, never use interrupts, even if we probe or
213  *      override-configure an IRQ.
214  *
215  * LIMIT_TRANSFERSIZE - if defined, limit the pseudo-dma transfers to 512
216  *      bytes at a time.  Since interrupts are disabled by default during
217  *      these transfers, we might need this to give reasonable interrupt
218  *      service time if the transfer size gets too large.
219  *
220  * LINKED - if defined, linked commands are supported.
221  *
222  * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
223  *
224  * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
225  *
226  * REAL_DMA_POLL - if defined, REAL DMA is used but the driver doesn't
227  *      rely on phase mismatch and EOP interrupts to determine end 
228  *      of phase.
229  *
230  * UNSAFE - leave interrupts enabled during pseudo-DMA transfers.  You
231  *          only really want to use this if you're having a problem with
232  *          dropped characters during high speed communications, and even
233  *          then, you're going to be better off twiddling with transfersize
234  *          in the high level code.
235  *
236  * Defaults for these will be provided although the user may want to adjust 
237  * these to allocate CPU resources to the SCSI driver or "real" code.
238  * 
239  * USLEEP_SLEEP - amount of time, in jiffies, to sleep
240  *
241  * USLEEP_POLL - amount of time, in jiffies, to poll
242  *
243  * These macros MUST be defined :
244  * NCR5380_local_declare() - declare any local variables needed for your
245  *      transfer routines.
246  *
247  * NCR5380_setup(instance) - initialize any local variables needed from a given
248  *      instance of the host adapter for NCR5380_{read,write,pread,pwrite}
249  * 
250  * NCR5380_read(register)  - read from the specified register
251  *
252  * NCR5380_write(register, value) - write to the specific register 
253  *
254  * NCR5380_implementation_fields  - additional fields needed for this 
255  *      specific implementation of the NCR5380
256  *
257  * Either real DMA *or* pseudo DMA may be implemented
258  * REAL functions : 
259  * NCR5380_REAL_DMA should be defined if real DMA is to be used.
260  * Note that the DMA setup functions should return the number of bytes 
261  *      that they were able to program the controller for.
262  *
263  * Also note that generic i386/PC versions of these macros are 
264  *      available as NCR5380_i386_dma_write_setup,
265  *      NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
266  *
267  * NCR5380_dma_write_setup(instance, src, count) - initialize
268  * NCR5380_dma_read_setup(instance, dst, count) - initialize
269  * NCR5380_dma_residual(instance); - residual count
270  *
271  * PSEUDO functions :
272  * NCR5380_pwrite(instance, src, count)
273  * NCR5380_pread(instance, dst, count);
274  *
275  * The generic driver is initialized by calling NCR5380_init(instance),
276  * after setting the appropriate host specific fields and ID.  If the 
277  * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
278  * possible) function may be used.
279  */
280
281 static int do_abort(struct Scsi_Host *host);
282 static void do_reset(struct Scsi_Host *host);
283
284 /*
285  *      initialize_SCp          -       init the scsi pointer field
286  *      @cmd: command block to set up
287  *
288  *      Set up the internal fields in the SCSI command.
289  */
290
291 static __inline__ void initialize_SCp(Scsi_Cmnd * cmd)
292 {
293         /* 
294          * Initialize the Scsi Pointer field so that all of the commands in the 
295          * various queues are valid.
296          */
297
298         if (cmd->use_sg) {
299                 cmd->SCp.buffer = (struct scatterlist *) cmd->request_buffer;
300                 cmd->SCp.buffers_residual = cmd->use_sg - 1;
301                 cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
302                                cmd->SCp.buffer->offset;
303                 cmd->SCp.this_residual = cmd->SCp.buffer->length;
304         } else {
305                 cmd->SCp.buffer = NULL;
306                 cmd->SCp.buffers_residual = 0;
307                 cmd->SCp.ptr = (char *) cmd->request_buffer;
308                 cmd->SCp.this_residual = cmd->request_bufflen;
309         }
310 }
311
312 /**
313  *      NCR5380_poll_politely   -       wait for NCR5380 status bits
314  *      @instance: controller to poll
315  *      @reg: 5380 register to poll
316  *      @bit: Bitmask to check
317  *      @val: Value required to exit
318  *
319  *      Polls the NCR5380 in a reasonably efficient manner waiting for
320  *      an event to occur, after a short quick poll we begin giving the
321  *      CPU back in non IRQ contexts
322  *
323  *      Returns the value of the register or a negative error code.
324  */
325  
326 static int NCR5380_poll_politely(struct Scsi_Host *instance, int reg, int bit, int val, int t)
327 {
328         NCR5380_local_declare();
329         int n = 500;            /* At about 8uS a cycle for the cpu access */
330         unsigned long end = jiffies + t;
331         int r;
332         
333         NCR5380_setup(instance);
334
335         while( n-- > 0)
336         {
337                 r = NCR5380_read(reg);
338                 if((r & bit) == val)
339                         return 0;
340                 cpu_relax();
341         }
342         
343         /* t time yet ? */
344         while(time_before(jiffies, end))
345         {
346                 r = NCR5380_read(reg);
347                 if((r & bit) == val)
348                         return 0;
349                 if(!in_interrupt())
350                         cond_resched();
351                 else
352                         cpu_relax();
353         }
354         return -ETIMEDOUT;
355 }
356
357 static struct {
358         unsigned char value;
359         const char *name;
360 } phases[] __maybe_unused = {
361         {PHASE_DATAOUT, "DATAOUT"}, 
362         {PHASE_DATAIN, "DATAIN"}, 
363         {PHASE_CMDOUT, "CMDOUT"}, 
364         {PHASE_STATIN, "STATIN"}, 
365         {PHASE_MSGOUT, "MSGOUT"}, 
366         {PHASE_MSGIN, "MSGIN"}, 
367         {PHASE_UNKNOWN, "UNKNOWN"}
368 };
369
370 #if NDEBUG
371 static struct {
372         unsigned char mask;
373         const char *name;
374 } signals[] = { 
375         {SR_DBP, "PARITY"}, 
376         {SR_RST, "RST"}, 
377         {SR_BSY, "BSY"}, 
378         {SR_REQ, "REQ"}, 
379         {SR_MSG, "MSG"}, 
380         {SR_CD, "CD"}, 
381         {SR_IO, "IO"}, 
382         {SR_SEL, "SEL"}, 
383         {0, NULL}
384 }, 
385 basrs[] = {
386         {BASR_ATN, "ATN"}, 
387         {BASR_ACK, "ACK"}, 
388         {0, NULL}
389 }, 
390 icrs[] = { 
391         {ICR_ASSERT_RST, "ASSERT RST"}, 
392         {ICR_ASSERT_ACK, "ASSERT ACK"}, 
393         {ICR_ASSERT_BSY, "ASSERT BSY"}, 
394         {ICR_ASSERT_SEL, "ASSERT SEL"}, 
395         {ICR_ASSERT_ATN, "ASSERT ATN"}, 
396         {ICR_ASSERT_DATA, "ASSERT DATA"}, 
397         {0, NULL}
398 }, 
399 mrs[] = { 
400         {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, 
401         {MR_TARGET, "MODE TARGET"}, 
402         {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, 
403         {MR_ENABLE_PAR_INTR, "MODE PARITY INTR"}, 
404         {MR_MONITOR_BSY, "MODE MONITOR BSY"}, 
405         {MR_DMA_MODE, "MODE DMA"}, 
406         {MR_ARBITRATE, "MODE ARBITRATION"}, 
407         {0, NULL}
408 };
409
410 /**
411  *      NCR5380_print   -       print scsi bus signals
412  *      @instance:      adapter state to dump
413  *
414  *      Print the SCSI bus signals for debugging purposes
415  *
416  *      Locks: caller holds hostdata lock (not essential)
417  */
418
419 static void NCR5380_print(struct Scsi_Host *instance)
420 {
421         NCR5380_local_declare();
422         unsigned char status, data, basr, mr, icr, i;
423         NCR5380_setup(instance);
424
425         data = NCR5380_read(CURRENT_SCSI_DATA_REG);
426         status = NCR5380_read(STATUS_REG);
427         mr = NCR5380_read(MODE_REG);
428         icr = NCR5380_read(INITIATOR_COMMAND_REG);
429         basr = NCR5380_read(BUS_AND_STATUS_REG);
430
431         printk("STATUS_REG: %02x ", status);
432         for (i = 0; signals[i].mask; ++i)
433                 if (status & signals[i].mask)
434                         printk(",%s", signals[i].name);
435         printk("\nBASR: %02x ", basr);
436         for (i = 0; basrs[i].mask; ++i)
437                 if (basr & basrs[i].mask)
438                         printk(",%s", basrs[i].name);
439         printk("\nICR: %02x ", icr);
440         for (i = 0; icrs[i].mask; ++i)
441                 if (icr & icrs[i].mask)
442                         printk(",%s", icrs[i].name);
443         printk("\nMODE: %02x ", mr);
444         for (i = 0; mrs[i].mask; ++i)
445                 if (mr & mrs[i].mask)
446                         printk(",%s", mrs[i].name);
447         printk("\n");
448 }
449
450
451 /* 
452  *      NCR5380_print_phase     -       show SCSI phase
453  *      @instance: adapter to dump
454  *
455  *      Print the current SCSI phase for debugging purposes
456  *
457  *      Locks: none
458  */
459
460 static void NCR5380_print_phase(struct Scsi_Host *instance)
461 {
462         NCR5380_local_declare();
463         unsigned char status;
464         int i;
465         NCR5380_setup(instance);
466
467         status = NCR5380_read(STATUS_REG);
468         if (!(status & SR_REQ))
469                 printk("scsi%d : REQ not asserted, phase unknown.\n", instance->host_no);
470         else {
471                 for (i = 0; (phases[i].value != PHASE_UNKNOWN) && (phases[i].value != (status & PHASE_MASK)); ++i);
472                 printk("scsi%d : phase %s\n", instance->host_no, phases[i].name);
473         }
474 }
475 #endif
476
477 /*
478  * These need tweaking, and would probably work best as per-device 
479  * flags initialized differently for disk, tape, cd, etc devices.
480  * People with broken devices are free to experiment as to what gives
481  * the best results for them.
482  *
483  * USLEEP_SLEEP should be a minimum seek time.
484  *
485  * USLEEP_POLL should be a maximum rotational latency.
486  */
487 #ifndef USLEEP_SLEEP
488 /* 20 ms (reasonable hard disk speed) */
489 #define USLEEP_SLEEP (20*HZ/1000)
490 #endif
491 /* 300 RPM (floppy speed) */
492 #ifndef USLEEP_POLL
493 #define USLEEP_POLL (200*HZ/1000)
494 #endif
495 #ifndef USLEEP_WAITLONG
496 /* RvC: (reasonable time to wait on select error) */
497 #define USLEEP_WAITLONG USLEEP_SLEEP
498 #endif
499
500 /* 
501  * Function : int should_disconnect (unsigned char cmd)
502  *
503  * Purpose : decide whether a command would normally disconnect or 
504  *      not, since if it won't disconnect we should go to sleep.
505  *
506  * Input : cmd - opcode of SCSI command
507  *
508  * Returns : DISCONNECT_LONG if we should disconnect for a really long 
509  *      time (ie always, sleep, look for REQ active, sleep), 
510  *      DISCONNECT_TIME_TO_DATA if we would only disconnect for a normal
511  *      time-to-data delay, DISCONNECT_NONE if this command would return
512  *      immediately.
513  *
514  *      Future sleep algorithms based on time to data can exploit 
515  *      something like this so they can differentiate between "normal" 
516  *      (ie, read, write, seek) and unusual commands (ie, * format).
517  *
518  * Note : We don't deal with commands that handle an immediate disconnect,
519  *        
520  */
521
522 static int should_disconnect(unsigned char cmd)
523 {
524         switch (cmd) {
525         case READ_6:
526         case WRITE_6:
527         case SEEK_6:
528         case READ_10:
529         case WRITE_10:
530         case SEEK_10:
531                 return DISCONNECT_TIME_TO_DATA;
532         case FORMAT_UNIT:
533         case SEARCH_HIGH:
534         case SEARCH_LOW:
535         case SEARCH_EQUAL:
536                 return DISCONNECT_LONG;
537         default:
538                 return DISCONNECT_NONE;
539         }
540 }
541
542 static void NCR5380_set_timer(struct NCR5380_hostdata *hostdata, unsigned long timeout)
543 {
544         hostdata->time_expires = jiffies + timeout;
545         schedule_delayed_work(&hostdata->coroutine, timeout);
546 }
547
548
549 static int probe_irq __initdata = 0;
550
551 /**
552  *      probe_intr      -       helper for IRQ autoprobe
553  *      @irq: interrupt number
554  *      @dev_id: unused
555  *      @regs: unused
556  *
557  *      Set a flag to indicate the IRQ in question was received. This is
558  *      used by the IRQ probe code.
559  */
560  
561 static irqreturn_t __init probe_intr(int irq, void *dev_id)
562 {
563         probe_irq = irq;
564         return IRQ_HANDLED;
565 }
566
567 /**
568  *      NCR5380_probe_irq       -       find the IRQ of an NCR5380
569  *      @instance: NCR5380 controller
570  *      @possible: bitmask of ISA IRQ lines
571  *
572  *      Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
573  *      and then looking to see what interrupt actually turned up.
574  *
575  *      Locks: none, irqs must be enabled on entry
576  */
577
578 static int __init __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
579                                                 int possible)
580 {
581         NCR5380_local_declare();
582         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
583         unsigned long timeout;
584         int trying_irqs, i, mask;
585         NCR5380_setup(instance);
586
587         for (trying_irqs = i = 0, mask = 1; i < 16; ++i, mask <<= 1)
588                 if ((mask & possible) && (request_irq(i, &probe_intr, IRQF_DISABLED, "NCR-probe", NULL) == 0))
589                         trying_irqs |= mask;
590
591         timeout = jiffies + (250 * HZ / 1000);
592         probe_irq = SCSI_IRQ_NONE;
593
594         /*
595          * A interrupt is triggered whenever BSY = false, SEL = true
596          * and a bit set in the SELECT_ENABLE_REG is asserted on the 
597          * SCSI bus.
598          *
599          * Note that the bus is only driven when the phase control signals
600          * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
601          * to zero.
602          */
603
604         NCR5380_write(TARGET_COMMAND_REG, 0);
605         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
606         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
607         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
608
609         while (probe_irq == SCSI_IRQ_NONE && time_before(jiffies, timeout))
610                 schedule_timeout_uninterruptible(1);
611         
612         NCR5380_write(SELECT_ENABLE_REG, 0);
613         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
614
615         for (i = 0, mask = 1; i < 16; ++i, mask <<= 1)
616                 if (trying_irqs & mask)
617                         free_irq(i, NULL);
618
619         return probe_irq;
620 }
621
622 /**
623  *      NCR58380_print_options  -       show options
624  *      @instance: unused for now
625  *
626  *      Called by probe code indicating the NCR5380 driver options that 
627  *      were selected. At some point this will switch to runtime options
628  *      read from the adapter in question
629  *
630  *      Locks: none
631  */
632
633 static void __init __maybe_unused
634 NCR5380_print_options(struct Scsi_Host *instance)
635 {
636         printk(" generic options"
637 #ifdef AUTOPROBE_IRQ
638                " AUTOPROBE_IRQ"
639 #endif
640 #ifdef AUTOSENSE
641                " AUTOSENSE"
642 #endif
643 #ifdef DIFFERENTIAL
644                " DIFFERENTIAL"
645 #endif
646 #ifdef REAL_DMA
647                " REAL DMA"
648 #endif
649 #ifdef REAL_DMA_POLL
650                " REAL DMA POLL"
651 #endif
652 #ifdef PARITY
653                " PARITY"
654 #endif
655 #ifdef PSEUDO_DMA
656                " PSEUDO DMA"
657 #endif
658 #ifdef UNSAFE
659                " UNSAFE "
660 #endif
661             );
662         printk(" USLEEP, USLEEP_POLL=%d USLEEP_SLEEP=%d", USLEEP_POLL, USLEEP_SLEEP);
663         printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
664         if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400) {
665                 printk(" ncr53c400 release=%d", NCR53C400_PUBLIC_RELEASE);
666         }
667 }
668
669 /**
670  *      NCR5380_print_status    -       dump controller info
671  *      @instance: controller to dump
672  *
673  *      Print commands in the various queues, called from NCR5380_abort 
674  *      and NCR5380_debug to aid debugging.
675  *
676  *      Locks: called functions disable irqs
677  */
678
679 static void NCR5380_print_status(struct Scsi_Host *instance)
680 {
681         NCR5380_dprint(NDEBUG_ANY, instance);
682         NCR5380_dprint_phase(NDEBUG_ANY, instance);
683 }
684
685 /******************************************/
686 /*
687  * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
688  *
689  * *buffer: I/O buffer
690  * **start: if inout == FALSE pointer into buffer where user read should start
691  * offset: current offset
692  * length: length of buffer
693  * hostno: Scsi_Host host_no
694  * inout: TRUE - user is writing; FALSE - user is reading
695  *
696  * Return the number of bytes read from or written
697  */
698
699 #undef SPRINTF
700 #define SPRINTF(args...) do { if(pos < buffer + length-80) pos += sprintf(pos, ## args); } while(0)
701 static
702 char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length);
703 static
704 char *lprint_command(unsigned char *cmd, char *pos, char *buffer, int len);
705 static
706 char *lprint_opcode(int opcode, char *pos, char *buffer, int length);
707
708 static int __maybe_unused NCR5380_proc_info(struct Scsi_Host *instance,
709         char *buffer, char **start, off_t offset, int length, int inout)
710 {
711         char *pos = buffer;
712         struct NCR5380_hostdata *hostdata;
713         Scsi_Cmnd *ptr;
714
715         hostdata = (struct NCR5380_hostdata *) instance->hostdata;
716
717         if (inout) {            /* Has data been written to the file ? */
718 #ifdef DTC_PUBLIC_RELEASE
719                 dtc_wmaxi = dtc_maxi = 0;
720 #endif
721 #ifdef PAS16_PUBLIC_RELEASE
722                 pas_wmaxi = pas_maxi = 0;
723 #endif
724                 return (-ENOSYS);       /* Currently this is a no-op */
725         }
726         SPRINTF("NCR5380 core release=%d.   ", NCR5380_PUBLIC_RELEASE);
727         if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400)
728                 SPRINTF("ncr53c400 release=%d.  ", NCR53C400_PUBLIC_RELEASE);
729 #ifdef DTC_PUBLIC_RELEASE
730         SPRINTF("DTC 3180/3280 release %d", DTC_PUBLIC_RELEASE);
731 #endif
732 #ifdef T128_PUBLIC_RELEASE
733         SPRINTF("T128 release %d", T128_PUBLIC_RELEASE);
734 #endif
735 #ifdef GENERIC_NCR5380_PUBLIC_RELEASE
736         SPRINTF("Generic5380 release %d", GENERIC_NCR5380_PUBLIC_RELEASE);
737 #endif
738 #ifdef PAS16_PUBLIC_RELEASE
739         SPRINTF("PAS16 release=%d", PAS16_PUBLIC_RELEASE);
740 #endif
741
742         SPRINTF("\nBase Addr: 0x%05lX    ", (long) instance->base);
743         SPRINTF("io_port: %04x      ", (int) instance->io_port);
744         if (instance->irq == SCSI_IRQ_NONE)
745                 SPRINTF("IRQ: None.\n");
746         else
747                 SPRINTF("IRQ: %d.\n", instance->irq);
748
749 #ifdef DTC_PUBLIC_RELEASE
750         SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", dtc_wmaxi, dtc_maxi);
751 #endif
752 #ifdef PAS16_PUBLIC_RELEASE
753         SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", pas_wmaxi, pas_maxi);
754 #endif
755         spin_lock_irq(instance->host_lock);
756         if (!hostdata->connected)
757                 SPRINTF("scsi%d: no currently connected command\n", instance->host_no);
758         else
759                 pos = lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, pos, buffer, length);
760         SPRINTF("scsi%d: issue_queue\n", instance->host_no);
761         for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
762                 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
763
764         SPRINTF("scsi%d: disconnected_queue\n", instance->host_no);
765         for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
766                 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
767         spin_unlock_irq(instance->host_lock);
768         
769         *start = buffer;
770         if (pos - buffer < offset)
771                 return 0;
772         else if (pos - buffer - offset < length)
773                 return pos - buffer - offset;
774         return length;
775 }
776
777 static char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length)
778 {
779         SPRINTF("scsi%d : destination target %d, lun %d\n", cmd->device->host->host_no, cmd->device->id, cmd->device->lun);
780         SPRINTF("        command = ");
781         pos = lprint_command(cmd->cmnd, pos, buffer, length);
782         return (pos);
783 }
784
785 static char *lprint_command(unsigned char *command, char *pos, char *buffer, int length)
786 {
787         int i, s;
788         pos = lprint_opcode(command[0], pos, buffer, length);
789         for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
790                 SPRINTF("%02x ", command[i]);
791         SPRINTF("\n");
792         return (pos);
793 }
794
795 static char *lprint_opcode(int opcode, char *pos, char *buffer, int length)
796 {
797         SPRINTF("%2d (0x%02x)", opcode, opcode);
798         return (pos);
799 }
800
801
802 /**
803  *      NCR5380_init    -       initialise an NCR5380
804  *      @instance: adapter to configure
805  *      @flags: control flags
806  *
807  *      Initializes *instance and corresponding 5380 chip,
808  *      with flags OR'd into the initial flags value.
809  *
810  *      Notes : I assume that the host, hostno, and id bits have been
811  *      set correctly.  I don't care about the irq and other fields. 
812  *
813  *      Returns 0 for success
814  *
815  *      Locks: interrupts must be enabled when we are called 
816  */
817
818 static int __devinit NCR5380_init(struct Scsi_Host *instance, int flags)
819 {
820         NCR5380_local_declare();
821         int i, pass;
822         unsigned long timeout;
823         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
824
825         if(in_interrupt())
826                 printk(KERN_ERR "NCR5380_init called with interrupts off!\n");
827         /* 
828          * On NCR53C400 boards, NCR5380 registers are mapped 8 past 
829          * the base address.
830          */
831
832 #ifdef NCR53C400
833         if (flags & FLAG_NCR53C400)
834                 instance->NCR5380_instance_name += NCR53C400_address_adjust;
835 #endif
836
837         NCR5380_setup(instance);
838
839         hostdata->aborted = 0;
840         hostdata->id_mask = 1 << instance->this_id;
841         for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
842                 if (i > hostdata->id_mask)
843                         hostdata->id_higher_mask |= i;
844         for (i = 0; i < 8; ++i)
845                 hostdata->busy[i] = 0;
846 #ifdef REAL_DMA
847         hostdata->dmalen = 0;
848 #endif
849         hostdata->targets_present = 0;
850         hostdata->connected = NULL;
851         hostdata->issue_queue = NULL;
852         hostdata->disconnected_queue = NULL;
853         
854         INIT_DELAYED_WORK(&hostdata->coroutine, NCR5380_main);
855         
856 #ifdef NCR5380_STATS
857         for (i = 0; i < 8; ++i) {
858                 hostdata->time_read[i] = 0;
859                 hostdata->time_write[i] = 0;
860                 hostdata->bytes_read[i] = 0;
861                 hostdata->bytes_write[i] = 0;
862         }
863         hostdata->timebase = 0;
864         hostdata->pendingw = 0;
865         hostdata->pendingr = 0;
866 #endif
867
868         /* The CHECK code seems to break the 53C400. Will check it later maybe */
869         if (flags & FLAG_NCR53C400)
870                 hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags;
871         else
872                 hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags;
873
874         hostdata->host = instance;
875         hostdata->time_expires = 0;
876
877 #ifndef AUTOSENSE
878         if ((instance->cmd_per_lun > 1) || instance->can_queue > 1)
879                     printk(KERN_WARNING "scsi%d : WARNING : support for multiple outstanding commands enabled\n" "         without AUTOSENSE option, contingent allegiance conditions may\n"
880                            "         be incorrectly cleared.\n", instance->host_no);
881 #endif                          /* def AUTOSENSE */
882
883         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
884         NCR5380_write(MODE_REG, MR_BASE);
885         NCR5380_write(TARGET_COMMAND_REG, 0);
886         NCR5380_write(SELECT_ENABLE_REG, 0);
887
888 #ifdef NCR53C400
889         if (hostdata->flags & FLAG_NCR53C400) {
890                 NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE);
891         }
892 #endif
893
894         /* 
895          * Detect and correct bus wedge problems.
896          *
897          * If the system crashed, it may have crashed in a state 
898          * where a SCSI command was still executing, and the 
899          * SCSI bus is not in a BUS FREE STATE.
900          *
901          * If this is the case, we'll try to abort the currently
902          * established nexus which we know nothing about, and that
903          * failing, do a hard reset of the SCSI bus 
904          */
905
906         for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
907                 switch (pass) {
908                 case 1:
909                 case 3:
910                 case 5:
911                         printk(KERN_INFO "scsi%d: SCSI bus busy, waiting up to five seconds\n", instance->host_no);
912                         timeout = jiffies + 5 * HZ;
913                         NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, 0, 5*HZ);
914                         break;
915                 case 2:
916                         printk(KERN_WARNING "scsi%d: bus busy, attempting abort\n", instance->host_no);
917                         do_abort(instance);
918                         break;
919                 case 4:
920                         printk(KERN_WARNING "scsi%d: bus busy, attempting reset\n", instance->host_no);
921                         do_reset(instance);
922                         break;
923                 case 6:
924                         printk(KERN_ERR "scsi%d: bus locked solid or invalid override\n", instance->host_no);
925                         return -ENXIO;
926                 }
927         }
928         return 0;
929 }
930
931 /**
932  *      NCR5380_exit    -       remove an NCR5380
933  *      @instance: adapter to remove
934  */
935
936 static void __devexit NCR5380_exit(struct Scsi_Host *instance)
937 {
938         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
939
940         cancel_delayed_work(&hostdata->coroutine);
941         flush_scheduled_work();
942 }
943
944 /**
945  *      NCR5380_queue_command           -       queue a command
946  *      @cmd: SCSI command
947  *      @done: completion handler
948  *
949  *      cmd is added to the per instance issue_queue, with minor 
950  *      twiddling done to the host specific fields of cmd.  If the 
951  *      main coroutine is not running, it is restarted.
952  *
953  *      Locks: host lock taken by caller
954  */
955
956 static int NCR5380_queue_command(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *)) 
957 {
958         struct Scsi_Host *instance = cmd->device->host;
959         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
960         Scsi_Cmnd *tmp;
961
962 #if (NDEBUG & NDEBUG_NO_WRITE)
963         switch (cmd->cmnd[0]) {
964         case WRITE_6:
965         case WRITE_10:
966                 printk("scsi%d : WRITE attempted with NO_WRITE debugging flag set\n", instance->host_no);
967                 cmd->result = (DID_ERROR << 16);
968                 done(cmd);
969                 return 0;
970         }
971 #endif                          /* (NDEBUG & NDEBUG_NO_WRITE) */
972
973 #ifdef NCR5380_STATS
974         switch (cmd->cmnd[0]) {
975                 case WRITE:
976                 case WRITE_6:
977                 case WRITE_10:
978                         hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
979                         hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen;
980                         hostdata->pendingw++;
981                         break;
982                 case READ:
983                 case READ_6:
984                 case READ_10:
985                         hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
986                         hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen;
987                         hostdata->pendingr++;
988                         break;
989         }
990 #endif
991
992         /* 
993          * We use the host_scribble field as a pointer to the next command  
994          * in a queue 
995          */
996
997         cmd->host_scribble = NULL;
998         cmd->scsi_done = done;
999         cmd->result = 0;
1000
1001         /* 
1002          * Insert the cmd into the issue queue. Note that REQUEST SENSE 
1003          * commands are added to the head of the queue since any command will
1004          * clear the contingent allegiance condition that exists and the 
1005          * sense data is only guaranteed to be valid while the condition exists.
1006          */
1007
1008         if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1009                 LIST(cmd, hostdata->issue_queue);
1010                 cmd->host_scribble = (unsigned char *) hostdata->issue_queue;
1011                 hostdata->issue_queue = cmd;
1012         } else {
1013                 for (tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp->host_scribble; tmp = (Scsi_Cmnd *) tmp->host_scribble);
1014                 LIST(cmd, tmp);
1015                 tmp->host_scribble = (unsigned char *) cmd;
1016         }
1017         dprintk(NDEBUG_QUEUES, ("scsi%d : command added to %s of queue\n", instance->host_no, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"));
1018
1019         /* Run the coroutine if it isn't already running. */
1020         /* Kick off command processing */
1021         schedule_delayed_work(&hostdata->coroutine, 0);
1022         return 0;
1023 }
1024
1025
1026 /**
1027  *      NCR5380_main    -       NCR state machines
1028  *
1029  *      NCR5380_main is a coroutine that runs as long as more work can 
1030  *      be done on the NCR5380 host adapters in a system.  Both 
1031  *      NCR5380_queue_command() and NCR5380_intr() will try to start it 
1032  *      in case it is not running.
1033  * 
1034  *      Locks: called as its own thread with no locks held. Takes the
1035  *      host lock and called routines may take the isa dma lock.
1036  */
1037
1038 static void NCR5380_main(struct work_struct *work)
1039 {
1040         struct NCR5380_hostdata *hostdata =
1041                 container_of(work, struct NCR5380_hostdata, coroutine.work);
1042         struct Scsi_Host *instance = hostdata->host;
1043         Scsi_Cmnd *tmp, *prev;
1044         int done;
1045         
1046         spin_lock_irq(instance->host_lock);
1047         do {
1048                 /* Lock held here */
1049                 done = 1;
1050                 if (!hostdata->connected && !hostdata->selecting) {
1051                         dprintk(NDEBUG_MAIN, ("scsi%d : not connected\n", instance->host_no));
1052                         /*
1053                          * Search through the issue_queue for a command destined
1054                          * for a target that's not busy.
1055                          */
1056                         for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble) 
1057                         {
1058                                 if (prev != tmp)
1059                                         dprintk(NDEBUG_LISTS, ("MAIN tmp=%p   target=%d   busy=%d lun=%d\n", tmp, tmp->target, hostdata->busy[tmp->target], tmp->lun));
1060                                 /*  When we find one, remove it from the issue queue. */
1061                                 if (!(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))) {
1062                                         if (prev) {
1063                                                 REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
1064                                                 prev->host_scribble = tmp->host_scribble;
1065                                         } else {
1066                                                 REMOVE(-1, hostdata->issue_queue, tmp, tmp->host_scribble);
1067                                                 hostdata->issue_queue = (Scsi_Cmnd *) tmp->host_scribble;
1068                                         }
1069                                         tmp->host_scribble = NULL;
1070
1071                                         /* 
1072                                          * Attempt to establish an I_T_L nexus here. 
1073                                          * On success, instance->hostdata->connected is set.
1074                                          * On failure, we must add the command back to the
1075                                          *   issue queue so we can keep trying. 
1076                                          */
1077                                         dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main() : command for target %d lun %d removed from issue_queue\n", instance->host_no, tmp->target, tmp->lun));
1078         
1079                                         /*
1080                                          * A successful selection is defined as one that 
1081                                          * leaves us with the command connected and 
1082                                          * in hostdata->connected, OR has terminated the
1083                                          * command.
1084                                          *
1085                                          * With successful commands, we fall through
1086                                          * and see if we can do an information transfer,
1087                                          * with failures we will restart.
1088                                          */
1089                                         hostdata->selecting = NULL;
1090                                         /* RvC: have to preset this to indicate a new command is being performed */
1091
1092                                         if (!NCR5380_select(instance, tmp,
1093                                                             /* 
1094                                                              * REQUEST SENSE commands are issued without tagged
1095                                                              * queueing, even on SCSI-II devices because the 
1096                                                              * contingent allegiance condition exists for the 
1097                                                              * entire unit.
1098                                                              */
1099                                                             (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1100                                                 break;
1101                                         } else {
1102                                                 LIST(tmp, hostdata->issue_queue);
1103                                                 tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1104                                                 hostdata->issue_queue = tmp;
1105                                                 done = 0;
1106                                                 dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main(): select() failed, returned to issue_queue\n", instance->host_no));
1107                                         }
1108                                         /* lock held here still */
1109                                 }       /* if target/lun is not busy */
1110                         }       /* for */
1111                         /* exited locked */
1112                 }       /* if (!hostdata->connected) */
1113                 if (hostdata->selecting) {
1114                         tmp = (Scsi_Cmnd *) hostdata->selecting;
1115                         /* Selection will drop and retake the lock */
1116                         if (!NCR5380_select(instance, tmp, (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1117                                 /* Ok ?? */
1118                         } else {
1119                                 /* RvC: device failed, so we wait a long time
1120                                    this is needed for Mustek scanners, that
1121                                    do not respond to commands immediately
1122                                    after a scan */
1123                                 printk(KERN_DEBUG "scsi%d: device %d did not respond in time\n", instance->host_no, tmp->device->id);
1124                                 LIST(tmp, hostdata->issue_queue);
1125                                 tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1126                                 hostdata->issue_queue = tmp;
1127                                 NCR5380_set_timer(hostdata, USLEEP_WAITLONG);
1128                         }
1129                 }       /* if hostdata->selecting */
1130                 if (hostdata->connected
1131 #ifdef REAL_DMA
1132                     && !hostdata->dmalen
1133 #endif
1134                     && (!hostdata->time_expires || time_before_eq(hostdata->time_expires, jiffies))
1135                     ) {
1136                         dprintk(NDEBUG_MAIN, ("scsi%d : main() : performing information transfer\n", instance->host_no));
1137                         NCR5380_information_transfer(instance);
1138                         dprintk(NDEBUG_MAIN, ("scsi%d : main() : done set false\n", instance->host_no));
1139                         done = 0;
1140                 } else
1141                         break;
1142         } while (!done);
1143         
1144         spin_unlock_irq(instance->host_lock);
1145 }
1146
1147 #ifndef DONT_USE_INTR
1148
1149 /**
1150  *      NCR5380_intr    -       generic NCR5380 irq handler
1151  *      @irq: interrupt number
1152  *      @dev_id: device info
1153  *
1154  *      Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1155  *      from the disconnected queue, and restarting NCR5380_main() 
1156  *      as required.
1157  *
1158  *      Locks: takes the needed instance locks
1159  */
1160
1161 static irqreturn_t NCR5380_intr(int irq, void *dev_id) 
1162 {
1163         NCR5380_local_declare();
1164         struct Scsi_Host *instance = (struct Scsi_Host *)dev_id;
1165         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1166         int done;
1167         unsigned char basr;
1168         unsigned long flags;
1169
1170         dprintk(NDEBUG_INTR, ("scsi : NCR5380 irq %d triggered\n", irq));
1171
1172         do {
1173                 done = 1;
1174                 spin_lock_irqsave(instance->host_lock, flags);
1175                 /* Look for pending interrupts */
1176                 NCR5380_setup(instance);
1177                 basr = NCR5380_read(BUS_AND_STATUS_REG);
1178                 /* XXX dispatch to appropriate routine if found and done=0 */
1179                 if (basr & BASR_IRQ) {
1180                         NCR5380_dprint(NDEBUG_INTR, instance);
1181                         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1182                                 done = 0;
1183                                 dprintk(NDEBUG_INTR, ("scsi%d : SEL interrupt\n", instance->host_no));
1184                                 NCR5380_reselect(instance);
1185                                 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1186                         } else if (basr & BASR_PARITY_ERROR) {
1187                                 dprintk(NDEBUG_INTR, ("scsi%d : PARITY interrupt\n", instance->host_no));
1188                                 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1189                         } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1190                                 dprintk(NDEBUG_INTR, ("scsi%d : RESET interrupt\n", instance->host_no));
1191                                 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1192                         } else {
1193 #if defined(REAL_DMA)
1194                                 /*
1195                                  * We should only get PHASE MISMATCH and EOP interrupts
1196                                  * if we have DMA enabled, so do a sanity check based on
1197                                  * the current setting of the MODE register.
1198                                  */
1199
1200                                 if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr & BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
1201                                         int transfered;
1202
1203                                         if (!hostdata->connected)
1204                                                 panic("scsi%d : received end of DMA interrupt with no connected cmd\n", instance->hostno);
1205
1206                                         transfered = (hostdata->dmalen - NCR5380_dma_residual(instance));
1207                                         hostdata->connected->SCp.this_residual -= transferred;
1208                                         hostdata->connected->SCp.ptr += transferred;
1209                                         hostdata->dmalen = 0;
1210
1211                                         (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1212                                                         
1213                                         /* FIXME: we need to poll briefly then defer a workqueue task ! */
1214                                         NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
1215
1216                                         NCR5380_write(MODE_REG, MR_BASE);
1217                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1218                                 }
1219 #else
1220                                 dprintk(NDEBUG_INTR, ("scsi : unknown interrupt, BASR 0x%X, MR 0x%X, SR 0x%x\n", basr, NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG)));
1221                                 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1222 #endif
1223                         }
1224                 }       /* if BASR_IRQ */
1225                 spin_unlock_irqrestore(instance->host_lock, flags);
1226                 if(!done)
1227                         schedule_delayed_work(&hostdata->coroutine, 0);
1228         } while (!done);
1229         return IRQ_HANDLED;
1230 }
1231
1232 #endif 
1233
1234 /**
1235  *      collect_stats           -       collect stats on a scsi command
1236  *      @hostdata: adapter 
1237  *      @cmd: command being issued
1238  *
1239  *      Update the statistical data by parsing the command in question
1240  */
1241  
1242 static void collect_stats(struct NCR5380_hostdata *hostdata, Scsi_Cmnd * cmd) 
1243 {
1244 #ifdef NCR5380_STATS
1245         switch (cmd->cmnd[0]) {
1246         case WRITE:
1247         case WRITE_6:
1248         case WRITE_10:
1249                 hostdata->time_write[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1250                 hostdata->pendingw--;
1251                 break;
1252         case READ:
1253         case READ_6:
1254         case READ_10:
1255                 hostdata->time_read[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1256                 hostdata->pendingr--;
1257                 break;
1258         }
1259 #endif
1260 }
1261
1262
1263 /* 
1264  * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd, 
1265  *      int tag);
1266  *
1267  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1268  *      including ARBITRATION, SELECTION, and initial message out for 
1269  *      IDENTIFY and queue messages. 
1270  *
1271  * Inputs : instance - instantiation of the 5380 driver on which this 
1272  *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for 
1273  *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for 
1274  *      the command that is presently connected.
1275  * 
1276  * Returns : -1 if selection could not execute for some reason,
1277  *      0 if selection succeeded or failed because the target 
1278  *      did not respond.
1279  *
1280  * Side effects : 
1281  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit 
1282  *              with registers as they should have been on entry - ie
1283  *              SELECT_ENABLE will be set appropriately, the NCR5380
1284  *              will cease to drive any SCSI bus signals.
1285  *
1286  *      If successful : I_T_L or I_T_L_Q nexus will be established, 
1287  *              instance->connected will be set to cmd.  
1288  *              SELECT interrupt will be disabled.
1289  *
1290  *      If failed (no target) : cmd->scsi_done() will be called, and the 
1291  *              cmd->result host byte set to DID_BAD_TARGET.
1292  *
1293  *      Locks: caller holds hostdata lock in IRQ mode
1294  */
1295  
1296 static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd * cmd, int tag) 
1297 {
1298         NCR5380_local_declare();
1299         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1300         unsigned char tmp[3], phase;
1301         unsigned char *data;
1302         int len;
1303         unsigned long timeout;
1304         unsigned char value;
1305         int err;
1306         NCR5380_setup(instance);
1307
1308         if (hostdata->selecting)
1309                 goto part2;
1310
1311         hostdata->restart_select = 0;
1312
1313         NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1314         dprintk(NDEBUG_ARBITRATION, ("scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id));
1315
1316         /* 
1317          * Set the phase bits to 0, otherwise the NCR5380 won't drive the 
1318          * data bus during SELECTION.
1319          */
1320
1321         NCR5380_write(TARGET_COMMAND_REG, 0);
1322
1323         /* 
1324          * Start arbitration.
1325          */
1326
1327         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1328         NCR5380_write(MODE_REG, MR_ARBITRATE);
1329
1330
1331         /* We can be relaxed here, interrupts are on, we are
1332            in workqueue context, the birds are singing in the trees */
1333         spin_unlock_irq(instance->host_lock);
1334         err = NCR5380_poll_politely(instance, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, 5*HZ);
1335         spin_lock_irq(instance->host_lock);
1336         if (err < 0) {
1337                 printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
1338                 NCR5380_write(MODE_REG, MR_BASE);
1339                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1340                 goto failed;
1341         }
1342
1343         dprintk(NDEBUG_ARBITRATION, ("scsi%d : arbitration complete\n", instance->host_no));
1344
1345         /* 
1346          * The arbitration delay is 2.2us, but this is a minimum and there is 
1347          * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1348          * the integral nature of udelay().
1349          *
1350          */
1351
1352         udelay(3);
1353
1354         /* Check for lost arbitration */
1355         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) || (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1356                 NCR5380_write(MODE_REG, MR_BASE);
1357                 dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", instance->host_no));
1358                 goto failed;
1359         }
1360         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL);
1361
1362         if (!(hostdata->flags & FLAG_DTC3181E) &&
1363             /* RvC: DTC3181E has some trouble with this
1364              *      so we simply removed it. Seems to work with
1365              *      only Mustek scanner attached
1366              */
1367             (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1368                 NCR5380_write(MODE_REG, MR_BASE);
1369                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1370                 dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no));
1371                 goto failed;
1372         }
1373         /* 
1374          * Again, bus clear + bus settle time is 1.2us, however, this is 
1375          * a minimum so we'll udelay ceil(1.2)
1376          */
1377
1378         udelay(2);
1379
1380         dprintk(NDEBUG_ARBITRATION, ("scsi%d : won arbitration\n", instance->host_no));
1381
1382         /* 
1383          * Now that we have won arbitration, start Selection process, asserting 
1384          * the host and target ID's on the SCSI bus.
1385          */
1386
1387         NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << scmd_id(cmd))));
1388
1389         /* 
1390          * Raise ATN while SEL is true before BSY goes false from arbitration,
1391          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1392          * phase immediately after selection.
1393          */
1394
1395         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1396         NCR5380_write(MODE_REG, MR_BASE);
1397
1398         /* 
1399          * Reselect interrupts must be turned off prior to the dropping of BSY,
1400          * otherwise we will trigger an interrupt.
1401          */
1402         NCR5380_write(SELECT_ENABLE_REG, 0);
1403
1404         /*
1405          * The initiator shall then wait at least two deskew delays and release 
1406          * the BSY signal.
1407          */
1408         udelay(1);              /* wingel -- wait two bus deskew delay >2*45ns */
1409
1410         /* Reset BSY */
1411         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1412
1413         /* 
1414          * Something weird happens when we cease to drive BSY - looks
1415          * like the board/chip is letting us do another read before the 
1416          * appropriate propagation delay has expired, and we're confusing
1417          * a BSY signal from ourselves as the target's response to SELECTION.
1418          *
1419          * A small delay (the 'C++' frontend breaks the pipeline with an
1420          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1421          * tighter 'C' code breaks and requires this) solves the problem - 
1422          * the 1 us delay is arbitrary, and only used because this delay will 
1423          * be the same on other platforms and since it works here, it should 
1424          * work there.
1425          *
1426          * wingel suggests that this could be due to failing to wait
1427          * one deskew delay.
1428          */
1429
1430         udelay(1);
1431
1432         dprintk(NDEBUG_SELECTION, ("scsi%d : selecting target %d\n", instance->host_no, scmd_id(cmd)));
1433
1434         /* 
1435          * The SCSI specification calls for a 250 ms timeout for the actual 
1436          * selection.
1437          */
1438
1439         timeout = jiffies + (250 * HZ / 1000);
1440
1441         /* 
1442          * XXX very interesting - we're seeing a bounce where the BSY we 
1443          * asserted is being reflected / still asserted (propagation delay?)
1444          * and it's detecting as true.  Sigh.
1445          */
1446
1447         hostdata->select_time = 0;      /* we count the clock ticks at which we polled */
1448         hostdata->selecting = cmd;
1449
1450 part2:
1451         /* RvC: here we enter after a sleeping period, or immediately after
1452            execution of part 1
1453            we poll only once ech clock tick */
1454         value = NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO);
1455
1456         if (!value && (hostdata->select_time < HZ/4)) {
1457                 /* RvC: we still must wait for a device response */
1458                 hostdata->select_time++;        /* after 25 ticks the device has failed */
1459                 NCR5380_set_timer(hostdata, 1);
1460                 return 0;       /* RvC: we return here with hostdata->selecting set,
1461                                    to go to sleep */
1462         }
1463
1464         hostdata->selecting = NULL;/* clear this pointer, because we passed the
1465                                            waiting period */
1466         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1467                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1468                 NCR5380_reselect(instance);
1469                 printk("scsi%d : reselection after won arbitration?\n", instance->host_no);
1470                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1471                 return -1;
1472         }
1473         /* 
1474          * No less than two deskew delays after the initiator detects the 
1475          * BSY signal is true, it shall release the SEL signal and may 
1476          * change the DATA BUS.                                     -wingel
1477          */
1478
1479         udelay(1);
1480
1481         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1482
1483         if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1484                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1485                 if (hostdata->targets_present & (1 << scmd_id(cmd))) {
1486                         printk(KERN_DEBUG "scsi%d : weirdness\n", instance->host_no);
1487                         if (hostdata->restart_select)
1488                                 printk(KERN_DEBUG "\trestart select\n");
1489                         NCR5380_dprint(NDEBUG_SELECTION, instance);
1490                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1491                         return -1;
1492                 }
1493                 cmd->result = DID_BAD_TARGET << 16;
1494                 collect_stats(hostdata, cmd);
1495                 cmd->scsi_done(cmd);
1496                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1497                 dprintk(NDEBUG_SELECTION, ("scsi%d : target did not respond within 250ms\n", instance->host_no));
1498                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1499                 return 0;
1500         }
1501         hostdata->targets_present |= (1 << scmd_id(cmd));
1502
1503         /*
1504          * Since we followed the SCSI spec, and raised ATN while SEL 
1505          * was true but before BSY was false during selection, the information
1506          * transfer phase should be a MESSAGE OUT phase so that we can send the
1507          * IDENTIFY message.
1508          * 
1509          * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1510          * message (2 bytes) with a tag ID that we increment with every command
1511          * until it wraps back to 0.
1512          *
1513          * XXX - it turns out that there are some broken SCSI-II devices,
1514          *       which claim to support tagged queuing but fail when more than
1515          *       some number of commands are issued at once.
1516          */
1517
1518         /* Wait for start of REQ/ACK handshake */
1519
1520         spin_unlock_irq(instance->host_lock);
1521         err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1522         spin_lock_irq(instance->host_lock);
1523         
1524         if(err) {
1525                 printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
1526                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1527                 goto failed;
1528         }
1529
1530         dprintk(NDEBUG_SELECTION, ("scsi%d : target %d selected, going into MESSAGE OUT phase.\n", instance->host_no, cmd->device->id));
1531         tmp[0] = IDENTIFY(((instance->irq == SCSI_IRQ_NONE) ? 0 : 1), cmd->device->lun);
1532
1533         len = 1;
1534         cmd->tag = 0;
1535
1536         /* Send message(s) */
1537         data = tmp;
1538         phase = PHASE_MSGOUT;
1539         NCR5380_transfer_pio(instance, &phase, &len, &data);
1540         dprintk(NDEBUG_SELECTION, ("scsi%d : nexus established.\n", instance->host_no));
1541         /* XXX need to handle errors here */
1542         hostdata->connected = cmd;
1543         hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1544
1545         if (cmd->SCp.ptr != (char *)cmd->sense_buffer) {
1546                 initialize_SCp(cmd);
1547         }
1548
1549         return 0;
1550
1551         /* Selection failed */
1552 failed:
1553         return -1;
1554
1555 }
1556
1557 /* 
1558  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance, 
1559  *      unsigned char *phase, int *count, unsigned char **data)
1560  *
1561  * Purpose : transfers data in given phase using polled I/O
1562  *
1563  * Inputs : instance - instance of driver, *phase - pointer to 
1564  *      what phase is expected, *count - pointer to number of 
1565  *      bytes to transfer, **data - pointer to data pointer.
1566  * 
1567  * Returns : -1 when different phase is entered without transferring
1568  *      maximum number of bytes, 0 if all bytes or transfered or exit
1569  *      is in same phase.
1570  *
1571  *      Also, *phase, *count, *data are modified in place.
1572  *
1573  * XXX Note : handling for bus free may be useful.
1574  */
1575
1576 /*
1577  * Note : this code is not as quick as it could be, however it 
1578  * IS 100% reliable, and for the actual data transfer where speed
1579  * counts, we will always do a pseudo DMA or DMA transfer.
1580  */
1581
1582 static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1583         NCR5380_local_declare();
1584         unsigned char p = *phase, tmp;
1585         int c = *count;
1586         unsigned char *d = *data;
1587         /*
1588          *      RvC: some administrative data to process polling time
1589          */
1590         int break_allowed = 0;
1591         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1592         NCR5380_setup(instance);
1593
1594         if (!(p & SR_IO))
1595                 dprintk(NDEBUG_PIO, ("scsi%d : pio write %d bytes\n", instance->host_no, c));
1596         else
1597                 dprintk(NDEBUG_PIO, ("scsi%d : pio read %d bytes\n", instance->host_no, c));
1598
1599         /* 
1600          * The NCR5380 chip will only drive the SCSI bus when the 
1601          * phase specified in the appropriate bits of the TARGET COMMAND
1602          * REGISTER match the STATUS REGISTER
1603          */
1604
1605          NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1606
1607         /* RvC: don't know if this is necessary, but other SCSI I/O is short
1608          *      so breaks are not necessary there
1609          */
1610         if ((p == PHASE_DATAIN) || (p == PHASE_DATAOUT)) {
1611                 break_allowed = 1;
1612         }
1613         do {
1614                 /* 
1615                  * Wait for assertion of REQ, after which the phase bits will be 
1616                  * valid 
1617                  */
1618
1619                 /* RvC: we simply poll once, after that we stop temporarily
1620                  *      and let the device buffer fill up
1621                  *      if breaking is not allowed, we keep polling as long as needed
1622                  */
1623
1624                 /* FIXME */
1625                 while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ) && !break_allowed);
1626                 if (!(tmp & SR_REQ)) {
1627                         /* timeout condition */
1628                         NCR5380_set_timer(hostdata, USLEEP_SLEEP);
1629                         break;
1630                 }
1631
1632                 dprintk(NDEBUG_HANDSHAKE, ("scsi%d : REQ detected\n", instance->host_no));
1633
1634                 /* Check for phase mismatch */
1635                 if ((tmp & PHASE_MASK) != p) {
1636                         dprintk(NDEBUG_HANDSHAKE, ("scsi%d : phase mismatch\n", instance->host_no));
1637                         NCR5380_dprint_phase(NDEBUG_HANDSHAKE, instance);
1638                         break;
1639                 }
1640                 /* Do actual transfer from SCSI bus to / from memory */
1641                 if (!(p & SR_IO))
1642                         NCR5380_write(OUTPUT_DATA_REG, *d);
1643                 else
1644                         *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1645
1646                 ++d;
1647
1648                 /* 
1649                  * The SCSI standard suggests that in MSGOUT phase, the initiator
1650                  * should drop ATN on the last byte of the message phase
1651                  * after REQ has been asserted for the handshake but before
1652                  * the initiator raises ACK.
1653                  */
1654
1655                 if (!(p & SR_IO)) {
1656                         if (!((p & SR_MSG) && c > 1)) {
1657                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1658                                 NCR5380_dprint(NDEBUG_PIO, instance);
1659                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1660                         } else {
1661                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1662                                 NCR5380_dprint(NDEBUG_PIO, instance);
1663                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1664                         }
1665                 } else {
1666                         NCR5380_dprint(NDEBUG_PIO, instance);
1667                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1668                 }
1669
1670                 /* FIXME - if this fails bus reset ?? */
1671                 NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 5*HZ);
1672                 dprintk(NDEBUG_HANDSHAKE, ("scsi%d : req false, handshake complete\n", instance->host_no));
1673
1674 /*
1675  * We have several special cases to consider during REQ/ACK handshaking : 
1676  * 1.  We were in MSGOUT phase, and we are on the last byte of the 
1677  *      message.  ATN must be dropped as ACK is dropped.
1678  *
1679  * 2.  We are in a MSGIN phase, and we are on the last byte of the  
1680  *      message.  We must exit with ACK asserted, so that the calling
1681  *      code may raise ATN before dropping ACK to reject the message.
1682  *
1683  * 3.  ACK and ATN are clear and the target may proceed as normal.
1684  */
1685                 if (!(p == PHASE_MSGIN && c == 1)) {
1686                         if (p == PHASE_MSGOUT && c > 1)
1687                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1688                         else
1689                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1690                 }
1691         } while (--c);
1692
1693         dprintk(NDEBUG_PIO, ("scsi%d : residual %d\n", instance->host_no, c));
1694
1695         *count = c;
1696         *data = d;
1697         tmp = NCR5380_read(STATUS_REG);
1698         if (tmp & SR_REQ)
1699                 *phase = tmp & PHASE_MASK;
1700         else
1701                 *phase = PHASE_UNKNOWN;
1702
1703         if (!c || (*phase == p))
1704                 return 0;
1705         else
1706                 return -1;
1707 }
1708
1709 /**
1710  *      do_reset        -       issue a reset command
1711  *      @host: adapter to reset
1712  *
1713  *      Issue a reset sequence to the NCR5380 and try and get the bus
1714  *      back into sane shape.
1715  *
1716  *      Locks: caller holds queue lock
1717  */
1718  
1719 static void do_reset(struct Scsi_Host *host) {
1720         NCR5380_local_declare();
1721         NCR5380_setup(host);
1722
1723         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1724         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1725         udelay(25);
1726         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1727 }
1728
1729 /*
1730  * Function : do_abort (Scsi_Host *host)
1731  * 
1732  * Purpose : abort the currently established nexus.  Should only be 
1733  *      called from a routine which can drop into a 
1734  * 
1735  * Returns : 0 on success, -1 on failure.
1736  *
1737  * Locks: queue lock held by caller
1738  *      FIXME: sort this out and get new_eh running
1739  */
1740
1741 static int do_abort(struct Scsi_Host *host) {
1742         NCR5380_local_declare();
1743         unsigned char *msgptr, phase, tmp;
1744         int len;
1745         int rc;
1746         NCR5380_setup(host);
1747
1748
1749         /* Request message out phase */
1750         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1751
1752         /* 
1753          * Wait for the target to indicate a valid phase by asserting 
1754          * REQ.  Once this happens, we'll have either a MSGOUT phase 
1755          * and can immediately send the ABORT message, or we'll have some 
1756          * other phase and will have to source/sink data.
1757          * 
1758          * We really don't care what value was on the bus or what value
1759          * the target sees, so we just handshake.
1760          */
1761
1762         rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, SR_REQ, 60 * HZ);
1763         
1764         if(rc < 0)
1765                 return -1;
1766
1767         tmp = (unsigned char)rc;
1768         
1769         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1770
1771         if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1772                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1773                 rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, 0, 3*HZ);
1774                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1775                 if(rc == -1)
1776                         return -1;
1777         }
1778         tmp = ABORT;
1779         msgptr = &tmp;
1780         len = 1;
1781         phase = PHASE_MSGOUT;
1782         NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1783
1784         /*
1785          * If we got here, and the command completed successfully,
1786          * we're about to go into bus free state.
1787          */
1788
1789         return len ? -1 : 0;
1790 }
1791
1792 #if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1793 /* 
1794  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance, 
1795  *      unsigned char *phase, int *count, unsigned char **data)
1796  *
1797  * Purpose : transfers data in given phase using either real
1798  *      or pseudo DMA.
1799  *
1800  * Inputs : instance - instance of driver, *phase - pointer to 
1801  *      what phase is expected, *count - pointer to number of 
1802  *      bytes to transfer, **data - pointer to data pointer.
1803  * 
1804  * Returns : -1 when different phase is entered without transferring
1805  *      maximum number of bytes, 0 if all bytes or transfered or exit
1806  *      is in same phase.
1807  *
1808  *      Also, *phase, *count, *data are modified in place.
1809  *
1810  *      Locks: io_request lock held by caller
1811  */
1812
1813
1814 static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1815         NCR5380_local_declare();
1816         register int c = *count;
1817         register unsigned char p = *phase;
1818         register unsigned char *d = *data;
1819         unsigned char tmp;
1820         int foo;
1821 #if defined(REAL_DMA_POLL)
1822         int cnt, toPIO;
1823         unsigned char saved_data = 0, overrun = 0, residue;
1824 #endif
1825
1826         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1827
1828         NCR5380_setup(instance);
1829
1830         if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1831                 *phase = tmp;
1832                 return -1;
1833         }
1834 #if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1835 #ifdef READ_OVERRUNS
1836         if (p & SR_IO) {
1837                 c -= 2;
1838         }
1839 #endif
1840         dprintk(NDEBUG_DMA, ("scsi%d : initializing DMA channel %d for %s, %d bytes %s %0x\n", instance->host_no, instance->dma_channel, (p & SR_IO) ? "reading" : "writing", c, (p & SR_IO) ? "to" : "from", (unsigned) d));
1841         hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1842 #endif
1843
1844         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1845
1846 #ifdef REAL_DMA
1847         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1848 #elif defined(REAL_DMA_POLL)
1849         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1850 #else
1851         /*
1852          * Note : on my sample board, watch-dog timeouts occurred when interrupts
1853          * were not disabled for the duration of a single DMA transfer, from 
1854          * before the setting of DMA mode to after transfer of the last byte.
1855          */
1856
1857 #if defined(PSEUDO_DMA) && defined(UNSAFE)
1858         spin_unlock_irq(instance->host_lock);
1859 #endif
1860         /* KLL May need eop and parity in 53c400 */
1861         if (hostdata->flags & FLAG_NCR53C400)
1862                 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_PAR_CHECK | MR_ENABLE_PAR_INTR | MR_ENABLE_EOP_INTR | MR_DMA_MODE | MR_MONITOR_BSY);
1863         else
1864                 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1865 #endif                          /* def REAL_DMA */
1866
1867         dprintk(NDEBUG_DMA, ("scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG)));
1868
1869         /* 
1870          *      On the PAS16 at least I/O recovery delays are not needed here.
1871          *      Everyone else seems to want them.
1872          */
1873
1874         if (p & SR_IO) {
1875                 io_recovery_delay(1);
1876                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1877         } else {
1878                 io_recovery_delay(1);
1879                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1880                 io_recovery_delay(1);
1881                 NCR5380_write(START_DMA_SEND_REG, 0);
1882                 io_recovery_delay(1);
1883         }
1884
1885 #if defined(REAL_DMA_POLL)
1886         do {
1887                 tmp = NCR5380_read(BUS_AND_STATUS_REG);
1888         } while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1889
1890 /*
1891    At this point, either we've completed DMA, or we have a phase mismatch,
1892    or we've unexpectedly lost BUSY (which is a real error).
1893
1894    For write DMAs, we want to wait until the last byte has been
1895    transferred out over the bus before we turn off DMA mode.  Alas, there
1896    seems to be no terribly good way of doing this on a 5380 under all
1897    conditions.  For non-scatter-gather operations, we can wait until REQ
1898    and ACK both go false, or until a phase mismatch occurs.  Gather-writes
1899    are nastier, since the device will be expecting more data than we
1900    are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1901    could test LAST BIT SENT to assure transfer (I imagine this is precisely
1902    why this signal was added to the newer chips) but on the older 538[01]
1903    this signal does not exist.  The workaround for this lack is a watchdog;
1904    we bail out of the wait-loop after a modest amount of wait-time if
1905    the usual exit conditions are not met.  Not a terribly clean or
1906    correct solution :-%
1907
1908    Reads are equally tricky due to a nasty characteristic of the NCR5380.
1909    If the chip is in DMA mode for an READ, it will respond to a target's
1910    REQ by latching the SCSI data into the INPUT DATA register and asserting
1911    ACK, even if it has _already_ been notified by the DMA controller that
1912    the current DMA transfer has completed!  If the NCR5380 is then taken
1913    out of DMA mode, this already-acknowledged byte is lost.
1914
1915    This is not a problem for "one DMA transfer per command" reads, because
1916    the situation will never arise... either all of the data is DMA'ed
1917    properly, or the target switches to MESSAGE IN phase to signal a
1918    disconnection (either operation bringing the DMA to a clean halt).
1919    However, in order to handle scatter-reads, we must work around the
1920    problem.  The chosen fix is to DMA N-2 bytes, then check for the
1921    condition before taking the NCR5380 out of DMA mode.  One or two extra
1922    bytes are transferred via PIO as necessary to fill out the original
1923    request.
1924  */
1925
1926         if (p & SR_IO) {
1927 #ifdef READ_OVERRUNS
1928                 udelay(10);
1929                 if (((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK))) {
1930                         saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1931                         overrun = 1;
1932                 }
1933 #endif
1934         } else {
1935                 int limit = 100;
1936                 while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1937                         if (!(tmp & BASR_PHASE_MATCH))
1938                                 break;
1939                         if (--limit < 0)
1940                                 break;
1941                 }
1942         }
1943
1944         dprintk(NDEBUG_DMA, ("scsi%d : polled DMA transfer complete, basr 0x%X, sr 0x%X\n", instance->host_no, tmp, NCR5380_read(STATUS_REG)));
1945
1946         NCR5380_write(MODE_REG, MR_BASE);
1947         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1948
1949         residue = NCR5380_dma_residual(instance);
1950         c -= residue;
1951         *count -= c;
1952         *data += c;
1953         *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1954
1955 #ifdef READ_OVERRUNS
1956         if (*phase == p && (p & SR_IO) && residue == 0) {
1957                 if (overrun) {
1958                         dprintk(NDEBUG_DMA, ("Got an input overrun, using saved byte\n"));
1959                         **data = saved_data;
1960                         *data += 1;
1961                         *count -= 1;
1962                         cnt = toPIO = 1;
1963                 } else {
1964                         printk("No overrun??\n");
1965                         cnt = toPIO = 2;
1966                 }
1967                 dprintk(NDEBUG_DMA, ("Doing %d-byte PIO to 0x%X\n", cnt, *data));
1968                 NCR5380_transfer_pio(instance, phase, &cnt, data);
1969                 *count -= toPIO - cnt;
1970         }
1971 #endif
1972
1973         dprintk(NDEBUG_DMA, ("Return with data ptr = 0x%X, count %d, last 0x%X, next 0x%X\n", *data, *count, *(*data + *count - 1), *(*data + *count)));
1974         return 0;
1975
1976 #elif defined(REAL_DMA)
1977         return 0;
1978 #else                           /* defined(REAL_DMA_POLL) */
1979         if (p & SR_IO) {
1980 #ifdef DMA_WORKS_RIGHT
1981                 foo = NCR5380_pread(instance, d, c);
1982 #else
1983                 int diff = 1;
1984                 if (hostdata->flags & FLAG_NCR53C400) {
1985                         diff = 0;
1986                 }
1987                 if (!(foo = NCR5380_pread(instance, d, c - diff))) {
1988                         /*
1989                          * We can't disable DMA mode after successfully transferring 
1990                          * what we plan to be the last byte, since that would open up
1991                          * a race condition where if the target asserted REQ before 
1992                          * we got the DMA mode reset, the NCR5380 would have latched
1993                          * an additional byte into the INPUT DATA register and we'd
1994                          * have dropped it.
1995                          * 
1996                          * The workaround was to transfer one fewer bytes than we 
1997                          * intended to with the pseudo-DMA read function, wait for 
1998                          * the chip to latch the last byte, read it, and then disable
1999                          * pseudo-DMA mode.
2000                          * 
2001                          * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
2002                          * REQ is deasserted when ACK is asserted, and not reasserted
2003                          * until ACK goes false.  Since the NCR5380 won't lower ACK
2004                          * until DACK is asserted, which won't happen unless we twiddle
2005                          * the DMA port or we take the NCR5380 out of DMA mode, we 
2006                          * can guarantee that we won't handshake another extra 
2007                          * byte.
2008                          */
2009
2010                         if (!(hostdata->flags & FLAG_NCR53C400)) {
2011                                 while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ));
2012                                 /* Wait for clean handshake */
2013                                 while (NCR5380_read(STATUS_REG) & SR_REQ);
2014                                 d[c - 1] = NCR5380_read(INPUT_DATA_REG);
2015                         }
2016                 }
2017 #endif
2018         } else {
2019 #ifdef DMA_WORKS_RIGHT
2020                 foo = NCR5380_pwrite(instance, d, c);
2021 #else
2022                 int timeout;
2023                 dprintk(NDEBUG_C400_PWRITE, ("About to pwrite %d bytes\n", c));
2024                 if (!(foo = NCR5380_pwrite(instance, d, c))) {
2025                         /*
2026                          * Wait for the last byte to be sent.  If REQ is being asserted for 
2027                          * the byte we're interested, we'll ACK it and it will go false.  
2028                          */
2029                         if (!(hostdata->flags & FLAG_HAS_LAST_BYTE_SENT)) {
2030                                 timeout = 20000;
2031                                 while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ) && (NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH));
2032
2033                                 if (!timeout)
2034                                         dprintk(NDEBUG_LAST_BYTE_SENT, ("scsi%d : timed out on last byte\n", instance->host_no));
2035
2036                                 if (hostdata->flags & FLAG_CHECK_LAST_BYTE_SENT) {
2037                                         hostdata->flags &= ~FLAG_CHECK_LAST_BYTE_SENT;
2038                                         if (NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT) {
2039                                                 hostdata->flags |= FLAG_HAS_LAST_BYTE_SENT;
2040                                                 dprintk(NDEBUG_LAST_WRITE_SENT, ("scsi%d : last bit sent works\n", instance->host_no));
2041                                         }
2042                                 }
2043                         } else {
2044                                 dprintk(NDEBUG_C400_PWRITE, ("Waiting for LASTBYTE\n"));
2045                                 while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT));
2046                                 dprintk(NDEBUG_C400_PWRITE, ("Got LASTBYTE\n"));
2047                         }
2048                 }
2049 #endif
2050         }
2051         NCR5380_write(MODE_REG, MR_BASE);
2052         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2053
2054         if ((!(p & SR_IO)) && (hostdata->flags & FLAG_NCR53C400)) {
2055                 dprintk(NDEBUG_C400_PWRITE, ("53C400w: Checking for IRQ\n"));
2056                 if (NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) {
2057                         dprintk(NDEBUG_C400_PWRITE, ("53C400w:    got it, reading reset interrupt reg\n"));
2058                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2059                 } else {
2060                         printk("53C400w:    IRQ NOT THERE!\n");
2061                 }
2062         }
2063         *data = d + c;
2064         *count = 0;
2065         *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
2066 #if defined(PSEUDO_DMA) && defined(UNSAFE)
2067         spin_lock_irq(instance->host_lock);
2068 #endif                          /* defined(REAL_DMA_POLL) */
2069         return foo;
2070 #endif                          /* def REAL_DMA */
2071 }
2072 #endif                          /* defined(REAL_DMA) | defined(PSEUDO_DMA) */
2073
2074 /*
2075  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2076  *
2077  * Purpose : run through the various SCSI phases and do as the target 
2078  *      directs us to.  Operates on the currently connected command, 
2079  *      instance->connected.
2080  *
2081  * Inputs : instance, instance for which we are doing commands
2082  *
2083  * Side effects : SCSI things happen, the disconnected queue will be 
2084  *      modified if a command disconnects, *instance->connected will
2085  *      change.
2086  *
2087  * XXX Note : we need to watch for bus free or a reset condition here 
2088  *      to recover from an unexpected bus free condition.
2089  *
2090  * Locks: io_request_lock held by caller in IRQ mode
2091  */
2092
2093 static void NCR5380_information_transfer(struct Scsi_Host *instance) {
2094         NCR5380_local_declare();
2095         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)instance->hostdata;
2096         unsigned char msgout = NOP;
2097         int sink = 0;
2098         int len;
2099 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2100         int transfersize;
2101 #endif
2102         unsigned char *data;
2103         unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2104         Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2105         /* RvC: we need to set the end of the polling time */
2106         unsigned long poll_time = jiffies + USLEEP_POLL;
2107
2108         NCR5380_setup(instance);
2109
2110         while (1) {
2111                 tmp = NCR5380_read(STATUS_REG);
2112                 /* We only have a valid SCSI phase when REQ is asserted */
2113                 if (tmp & SR_REQ) {
2114                         phase = (tmp & PHASE_MASK);
2115                         if (phase != old_phase) {
2116                                 old_phase = phase;
2117                                 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2118                         }
2119                         if (sink && (phase != PHASE_MSGOUT)) {
2120                                 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2121
2122                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
2123                                 while (NCR5380_read(STATUS_REG) & SR_REQ);
2124                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2125                                 sink = 0;
2126                                 continue;
2127                         }
2128                         switch (phase) {
2129                         case PHASE_DATAIN:
2130                         case PHASE_DATAOUT:
2131 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2132                                 printk("scsi%d : NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n", instance->host_no);
2133                                 sink = 1;
2134                                 do_abort(instance);
2135                                 cmd->result = DID_ERROR << 16;
2136                                 cmd->done(cmd);
2137                                 return;
2138 #endif
2139                                 /* 
2140                                  * If there is no room left in the current buffer in the
2141                                  * scatter-gather list, move onto the next one.
2142                                  */
2143
2144                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2145                                         ++cmd->SCp.buffer;
2146                                         --cmd->SCp.buffers_residual;
2147                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
2148                                         cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
2149                                                        cmd->SCp.buffer->offset;
2150                                         dprintk(NDEBUG_INFORMATION, ("scsi%d : %d bytes and %d buffers left\n", instance->host_no, cmd->SCp.this_residual, cmd->SCp.buffers_residual));
2151                                 }
2152                                 /*
2153                                  * The preferred transfer method is going to be 
2154                                  * PSEUDO-DMA for systems that are strictly PIO,
2155                                  * since we can let the hardware do the handshaking.
2156                                  *
2157                                  * For this to work, we need to know the transfersize
2158                                  * ahead of time, since the pseudo-DMA code will sit
2159                                  * in an unconditional loop.
2160                                  */
2161
2162 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2163                                 /* KLL
2164                                  * PSEUDO_DMA is defined here. If this is the g_NCR5380
2165                                  * driver then it will always be defined, so the
2166                                  * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base
2167                                  * NCR5380 case.  I think this is a fairly clean solution.
2168                                  * We supplement these 2 if's with the flag.
2169                                  */
2170 #ifdef NCR5380_dma_xfer_len
2171                                 if (!cmd->device->borken && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) {
2172 #else
2173                                 transfersize = cmd->transfersize;
2174
2175 #ifdef LIMIT_TRANSFERSIZE       /* If we have problems with interrupt service */
2176                                 if (transfersize > 512)
2177                                         transfersize = 512;
2178 #endif                          /* LIMIT_TRANSFERSIZE */
2179
2180                                 if (!cmd->device->borken && transfersize && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && cmd->SCp.this_residual && !(cmd->SCp.this_residual % transfersize)) {
2181                                         /* Limit transfers to 32K, for xx400 & xx406
2182                                          * pseudoDMA that transfers in 128 bytes blocks. */
2183                                         if (transfersize > 32 * 1024)
2184                                                 transfersize = 32 * 1024;
2185 #endif
2186                                         len = transfersize;
2187                                         if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
2188                                                 /*
2189                                                  * If the watchdog timer fires, all future accesses to this
2190                                                  * device will use the polled-IO.
2191                                                  */
2192                                                 scmd_printk(KERN_INFO, cmd,
2193                                                             "switching to slow handshake\n");
2194                                                 cmd->device->borken = 1;
2195                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2196                                                 sink = 1;
2197                                                 do_abort(instance);
2198                                                 cmd->result = DID_ERROR << 16;
2199                                                 cmd->done(cmd);
2200                                                 /* XXX - need to source or sink data here, as appropriate */
2201                                         } else
2202                                                 cmd->SCp.this_residual -= transfersize - len;
2203                                 } else
2204 #endif                          /* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
2205                                         NCR5380_transfer_pio(instance, &phase, (int *) &cmd->SCp.this_residual, (unsigned char **)
2206                                                              &cmd->SCp.ptr);
2207                                 break;
2208                         case PHASE_MSGIN:
2209                                 len = 1;
2210                                 data = &tmp;
2211                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2212                                 cmd->SCp.Message = tmp;
2213
2214                                 switch (tmp) {
2215                                         /*
2216                                          * Linking lets us reduce the time required to get the 
2217                                          * next command out to the device, hopefully this will
2218                                          * mean we don't waste another revolution due to the delays
2219                                          * required by ARBITRATION and another SELECTION.
2220                                          *
2221                                          * In the current implementation proposal, low level drivers
2222                                          * merely have to start the next command, pointed to by 
2223                                          * next_link, done() is called as with unlinked commands.
2224                                          */
2225 #ifdef LINKED
2226                                 case LINKED_CMD_COMPLETE:
2227                                 case LINKED_FLG_CMD_COMPLETE:
2228                                         /* Accept message by clearing ACK */
2229                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2230                                         dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked command complete.\n", instance->host_no, cmd->device->id, cmd->device->lun));
2231                                         /* 
2232                                          * Sanity check : A linked command should only terminate with
2233                                          * one of these messages if there are more linked commands
2234                                          * available.
2235                                          */
2236                                         if (!cmd->next_link) {
2237                                                 printk("scsi%d : target %d lun %d linked command complete, no next_link\n" instance->host_no, cmd->device->id, cmd->device->lun);
2238                                                 sink = 1;
2239                                                 do_abort(instance);
2240                                                 return;
2241                                         }
2242                                         initialize_SCp(cmd->next_link);
2243                                         /* The next command is still part of this process */
2244                                         cmd->next_link->tag = cmd->tag;
2245                                         cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2246                                         dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked request done, calling scsi_done().\n", instance->host_no, cmd->device->id, cmd->device->lun));
2247                                         collect_stats(hostdata, cmd);
2248                                         cmd->scsi_done(cmd);
2249                                         cmd = hostdata->connected;
2250                                         break;
2251 #endif                          /* def LINKED */
2252                                 case ABORT:
2253                                 case COMMAND_COMPLETE:
2254                                         /* Accept message by clearing ACK */
2255                                         sink = 1;
2256                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2257                                         hostdata->connected = NULL;
2258                                         dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d, lun %d completed\n", instance->host_no, cmd->device->id, cmd->device->lun));
2259                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2260
2261                                         /* 
2262                                          * I'm not sure what the correct thing to do here is : 
2263                                          * 
2264                                          * If the command that just executed is NOT a request 
2265                                          * sense, the obvious thing to do is to set the result
2266                                          * code to the values of the stored parameters.
2267                                          * 
2268                                          * If it was a REQUEST SENSE command, we need some way 
2269                                          * to differentiate between the failure code of the original
2270                                          * and the failure code of the REQUEST sense - the obvious
2271                                          * case is success, where we fall through and leave the result
2272                                          * code unchanged.
2273                                          * 
2274                                          * The non-obvious place is where the REQUEST SENSE failed 
2275                                          */
2276
2277                                         if (cmd->cmnd[0] != REQUEST_SENSE)
2278                                                 cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2279                                         else if (status_byte(cmd->SCp.Status) != GOOD)
2280                                                 cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2281
2282 #ifdef AUTOSENSE
2283                                         if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2284                                                 dprintk(NDEBUG_AUTOSENSE, ("scsi%d : performing request sense\n", instance->host_no));
2285                                                 cmd->cmnd[0] = REQUEST_SENSE;
2286                                                 cmd->cmnd[1] &= 0xe0;
2287                                                 cmd->cmnd[2] = 0;
2288                                                 cmd->cmnd[3] = 0;
2289                                                 cmd->cmnd[4] = sizeof(cmd->sense_buffer);
2290                                                 cmd->cmnd[5] = 0;
2291
2292                                                 cmd->SCp.buffer = NULL;
2293                                                 cmd->SCp.buffers_residual = 0;
2294                                                 cmd->SCp.ptr = (char *) cmd->sense_buffer;
2295                                                 cmd->SCp.this_residual = sizeof(cmd->sense_buffer);
2296
2297                                                 LIST(cmd, hostdata->issue_queue);
2298                                                 cmd->host_scribble = (unsigned char *)
2299                                                     hostdata->issue_queue;
2300                                                 hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2301                                                 dprintk(NDEBUG_QUEUES, ("scsi%d : REQUEST SENSE added to head of issue queue\n", instance->host_no));
2302                                         } else
2303 #endif                          /* def AUTOSENSE */
2304                                         {
2305                                                 collect_stats(hostdata, cmd);
2306                                                 cmd->scsi_done(cmd);
2307                                         }
2308
2309                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2310                                         /* 
2311                                          * Restore phase bits to 0 so an interrupted selection, 
2312                                          * arbitration can resume.
2313                                          */
2314                                         NCR5380_write(TARGET_COMMAND_REG, 0);
2315
2316                                         while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2317                                                 barrier();
2318                                         return;
2319                                 case MESSAGE_REJECT:
2320                                         /* Accept message by clearing ACK */
2321                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2322                                         switch (hostdata->last_message) {
2323                                         case HEAD_OF_QUEUE_TAG:
2324                                         case ORDERED_QUEUE_TAG:
2325                                         case SIMPLE_QUEUE_TAG:
2326                                                 cmd->device->simple_tags = 0;
2327                                                 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2328                                                 break;
2329                                         default:
2330                                                 break;
2331                                         }
2332                                 case DISCONNECT:{
2333                                                 /* Accept message by clearing ACK */
2334                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2335                                                 cmd->device->disconnect = 1;
2336                                                 LIST(cmd, hostdata->disconnected_queue);
2337                                                 cmd->host_scribble = (unsigned char *)
2338                                                     hostdata->disconnected_queue;
2339                                                 hostdata->connected = NULL;
2340                                                 hostdata->disconnected_queue = cmd;
2341                                                 dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d lun %d was moved from connected to" "  the disconnected_queue\n", instance->host_no, cmd->device->id, cmd->device->lun));
2342                                                 /* 
2343                                                  * Restore phase bits to 0 so an interrupted selection, 
2344                                                  * arbitration can resume.
2345                                                  */
2346                                                 NCR5380_write(TARGET_COMMAND_REG, 0);
2347
2348                                                 /* Enable reselect interrupts */
2349                                                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2350                                                 /* Wait for bus free to avoid nasty timeouts - FIXME timeout !*/
2351                                                 /* NCR538_poll_politely(instance, STATUS_REG, SR_BSY, 0, 30 * HZ); */
2352                                                 while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2353                                                         barrier();
2354                                                 return;
2355                                         }
2356                                         /* 
2357                                          * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2358                                          * operation, in violation of the SCSI spec so we can safely 
2359                                          * ignore SAVE/RESTORE pointers calls.
2360                                          *
2361                                          * Unfortunately, some disks violate the SCSI spec and 
2362                                          * don't issue the required SAVE_POINTERS message before
2363                                          * disconnecting, and we have to break spec to remain 
2364                                          * compatible.
2365                                          */
2366                                 case SAVE_POINTERS:
2367                                 case RESTORE_POINTERS:
2368                                         /* Accept message by clearing ACK */
2369                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2370                                         break;
2371                                 case EXTENDED_MESSAGE:
2372 /* 
2373  * Extended messages are sent in the following format :
2374  * Byte         
2375  * 0            EXTENDED_MESSAGE == 1
2376  * 1            length (includes one byte for code, doesn't 
2377  *              include first two bytes)
2378  * 2            code
2379  * 3..length+1  arguments
2380  *
2381  * Start the extended message buffer with the EXTENDED_MESSAGE
2382  * byte, since spi_print_msg() wants the whole thing.  
2383  */
2384                                         extended_msg[0] = EXTENDED_MESSAGE;
2385                                         /* Accept first byte by clearing ACK */
2386                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2387                                         dprintk(NDEBUG_EXTENDED, ("scsi%d : receiving extended message\n", instance->host_no));
2388
2389                                         len = 2;
2390                                         data = extended_msg + 1;
2391                                         phase = PHASE_MSGIN;
2392                                         NCR5380_transfer_pio(instance, &phase, &len, &data);
2393
2394                                         dprintk(NDEBUG_EXTENDED, ("scsi%d : length=%d, code=0x%02x\n", instance->host_no, (int) extended_msg[1], (int) extended_msg[2]));
2395
2396                                         if (!len && extended_msg[1] <= (sizeof(extended_msg) - 1)) {
2397                                                 /* Accept third byte by clearing ACK */
2398                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2399                                                 len = extended_msg[1] - 1;
2400                                                 data = extended_msg + 3;
2401                                                 phase = PHASE_MSGIN;
2402
2403                                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2404                                                 dprintk(NDEBUG_EXTENDED, ("scsi%d : message received, residual %d\n", instance->host_no, len));
2405
2406                                                 switch (extended_msg[2]) {
2407                                                 case EXTENDED_SDTR:
2408                                                 case EXTENDED_WDTR:
2409                                                 case EXTENDED_MODIFY_DATA_POINTER:
2410                                                 case EXTENDED_EXTENDED_IDENTIFY:
2411                                                         tmp = 0;
2412                                                 }
2413                                         } else if (len) {
2414                                                 printk("scsi%d: error receiving extended message\n", instance->host_no);
2415                                                 tmp = 0;
2416                                         } else {
2417                                                 printk("scsi%d: extended message code %02x length %d is too long\n", instance->host_no, extended_msg[2], extended_msg[1]);
2418                                                 tmp = 0;
2419                                         }
2420                                         /* Fall through to reject message */
2421
2422                                         /* 
2423                                          * If we get something weird that we aren't expecting, 
2424                                          * reject it.
2425                                          */
2426                                 default:
2427                                         if (!tmp) {
2428                                                 printk("scsi%d: rejecting message ", instance->host_no);
2429                                                 spi_print_msg(extended_msg);
2430                                                 printk("\n");
2431                                         } else if (tmp != EXTENDED_MESSAGE)
2432                                                 scmd_printk(KERN_INFO, cmd,
2433                                                         "rejecting unknown message %02x\n",tmp);
2434                                         else
2435                                                 scmd_printk(KERN_INFO, cmd,
2436                                                         "rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);
2437
2438                                         msgout = MESSAGE_REJECT;
2439                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2440                                         break;
2441                                 }       /* switch (tmp) */
2442                                 break;
2443                         case PHASE_MSGOUT:
2444                                 len = 1;
2445                                 data = &msgout;
2446                                 hostdata->last_message = msgout;
2447                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2448                                 if (msgout == ABORT) {
2449                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2450                                         hostdata->connected = NULL;
2451                                         cmd->result = DID_ERROR << 16;
2452                                         collect_stats(hostdata, cmd);
2453                                         cmd->scsi_done(cmd);
2454                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2455                                         return;
2456                                 }
2457                                 msgout = NOP;
2458                                 break;
2459                         case PHASE_CMDOUT:
2460                                 len = cmd->cmd_len;
2461                                 data = cmd->cmnd;
2462                                 /* 
2463                                  * XXX for performance reasons, on machines with a 
2464                                  * PSEUDO-DMA architecture we should probably 
2465                                  * use the dma transfer function.  
2466                                  */
2467                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2468                                 if (!cmd->device->disconnect && should_disconnect(cmd->cmnd[0])) {
2469                                         NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2470                                         dprintk(NDEBUG_USLEEP, ("scsi%d : issued command, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2471                                         return;
2472                                 }
2473                                 break;
2474                         case PHASE_STATIN:
2475                                 len = 1;
2476                                 data = &tmp;
2477                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2478                                 cmd->SCp.Status = tmp;
2479                                 break;
2480                         default:
2481                                 printk("scsi%d : unknown phase\n", instance->host_no);
2482                                 NCR5380_dprint(NDEBUG_ALL, instance);
2483                         }       /* switch(phase) */
2484                 }               /* if (tmp * SR_REQ) */
2485                 else {
2486                         /* RvC: go to sleep if polling time expired
2487                          */
2488                         if (!cmd->device->disconnect && time_after_eq(jiffies, poll_time)) {
2489                                 NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2490                                 dprintk(NDEBUG_USLEEP, ("scsi%d : poll timed out, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2491                                 return;
2492                         }
2493                 }
2494         }                       /* while (1) */
2495 }
2496
2497 /*
2498  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2499  *
2500  * Purpose : does reselection, initializing the instance->connected 
2501  *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q 
2502  *      nexus has been reestablished,
2503  *      
2504  * Inputs : instance - this instance of the NCR5380.
2505  *
2506  * Locks: io_request_lock held by caller if IRQ driven
2507  */
2508
2509 static void NCR5380_reselect(struct Scsi_Host *instance) {
2510         NCR5380_local_declare();
2511         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)
2512          instance->hostdata;
2513         unsigned char target_mask;
2514         unsigned char lun, phase;
2515         int len;
2516         unsigned char msg[3];
2517         unsigned char *data;
2518         Scsi_Cmnd *tmp = NULL, *prev;
2519         int abort = 0;
2520         NCR5380_setup(instance);
2521
2522         /*
2523          * Disable arbitration, etc. since the host adapter obviously
2524          * lost, and tell an interrupted NCR5380_select() to restart.
2525          */
2526
2527         NCR5380_write(MODE_REG, MR_BASE);
2528         hostdata->restart_select = 1;
2529
2530         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2531         dprintk(NDEBUG_SELECTION, ("scsi%d : reselect\n", instance->host_no));
2532
2533         /* 
2534          * At this point, we have detected that our SCSI ID is on the bus,
2535          * SEL is true and BSY was false for at least one bus settle delay
2536          * (400 ns).
2537          *
2538          * We must assert BSY ourselves, until the target drops the SEL
2539          * signal.
2540          */
2541
2542         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2543
2544         /* FIXME: timeout too long, must fail to workqueue */   
2545         if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
2546                 abort = 1;
2547                 
2548         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2549
2550         /*
2551          * Wait for target to go into MSGIN.
2552          * FIXME: timeout needed and fail to work queeu
2553          */
2554
2555         if(NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 2*HZ))
2556                 abort = 1;
2557
2558         len = 1;
2559         data = msg;
2560         phase = PHASE_MSGIN;
2561         NCR5380_transfer_pio(instance, &phase, &len, &data);
2562
2563         if (!(msg[0] & 0x80)) {
2564                 printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
2565                 spi_print_msg(msg);
2566                 abort = 1;
2567         } else {
2568                 /* Accept message by clearing ACK */
2569                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2570                 lun = (msg[0] & 0x07);
2571
2572                 /* 
2573                  * We need to add code for SCSI-II to track which devices have
2574                  * I_T_L_Q nexuses established, and which have simple I_T_L
2575                  * nexuses so we can chose to do additional data transfer.
2576                  */
2577
2578                 /* 
2579                  * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we 
2580                  * just reestablished, and remove it from the disconnected queue.
2581                  */
2582
2583
2584                 for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
2585                         if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2586                             ) {
2587                                 if (prev) {
2588                                         REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
2589                                         prev->host_scribble = tmp->host_scribble;
2590                                 } else {
2591                                         REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
2592                                         hostdata->disconnected_queue = (Scsi_Cmnd *) tmp->host_scribble;
2593                                 }
2594                                 tmp->host_scribble = NULL;
2595                                 break;
2596                         }
2597                 if (!tmp) {
2598                         printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
2599                         /* 
2600                          * Since we have an established nexus that we can't do anything with,
2601                          * we must abort it.  
2602                          */
2603                         abort = 1;
2604                 }
2605         }
2606
2607         if (abort) {
2608                 do_abort(instance);
2609         } else {
2610                 hostdata->connected = tmp;
2611                 dprintk(NDEBUG_RESELECTION, ("scsi%d : nexus established, target = %d, lun = %d, tag = %d\n", instance->host_no, tmp->target, tmp->lun, tmp->tag));
2612         }
2613 }
2614
2615 /*
2616  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2617  *
2618  * Purpose : called by interrupt handler when DMA finishes or a phase
2619  *      mismatch occurs (which would finish the DMA transfer).  
2620  *
2621  * Inputs : instance - this instance of the NCR5380.
2622  *
2623  * Returns : pointer to the Scsi_Cmnd structure for which the I_T_L
2624  *      nexus has been reestablished, on failure NULL is returned.
2625  */
2626
2627 #ifdef REAL_DMA
2628 static void NCR5380_dma_complete(NCR5380_instance * instance) {
2629         NCR5380_local_declare();
2630         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2631         int transferred;
2632         NCR5380_setup(instance);
2633
2634         /*
2635          * XXX this might not be right.
2636          *
2637          * Wait for final byte to transfer, ie wait for ACK to go false.
2638          *
2639          * We should use the Last Byte Sent bit, unfortunately this is 
2640          * not available on the 5380/5381 (only the various CMOS chips)
2641          *
2642          * FIXME: timeout, and need to handle long timeout/irq case
2643          */
2644
2645         NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2646
2647         NCR5380_write(MODE_REG, MR_BASE);
2648         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2649
2650         /*
2651          * The only places we should see a phase mismatch and have to send
2652          * data from the same set of pointers will be the data transfer
2653          * phases.  So, residual, requested length are only important here.
2654          */
2655
2656         if (!(hostdata->connected->SCp.phase & SR_CD)) {
2657                 transferred = instance->dmalen - NCR5380_dma_residual();
2658                 hostdata->connected->SCp.this_residual -= transferred;
2659                 hostdata->connected->SCp.ptr += transferred;
2660         }
2661 }
2662 #endif                          /* def REAL_DMA */
2663
2664 /*
2665  * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2666  *
2667  * Purpose : abort a command
2668  *
2669  * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the 
2670  *      host byte of the result field to, if zero DID_ABORTED is 
2671  *      used.
2672  *
2673  * Returns : 0 - success, -1 on failure.
2674  *
2675  *      XXX - there is no way to abort the command that is currently 
2676  *      connected, you have to wait for it to complete.  If this is 
2677  *      a problem, we could implement longjmp() / setjmp(), setjmp()
2678  *      called where the loop started in NCR5380_main().
2679  *
2680  * Locks: host lock taken by caller
2681  */
2682
2683 static int NCR5380_abort(Scsi_Cmnd * cmd) {
2684         NCR5380_local_declare();
2685         struct Scsi_Host *instance = cmd->device->host;
2686         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2687         Scsi_Cmnd *tmp, **prev;
2688         
2689         printk(KERN_WARNING "scsi%d : aborting command\n", instance->host_no);
2690         scsi_print_command(cmd);
2691
2692         NCR5380_print_status(instance);
2693
2694         NCR5380_setup(instance);
2695
2696         dprintk(NDEBUG_ABORT, ("scsi%d : abort called\n", instance->host_no));
2697         dprintk(NDEBUG_ABORT, ("        basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG)));
2698
2699 #if 0
2700 /*
2701  * Case 1 : If the command is the currently executing command, 
2702  * we'll set the aborted flag and return control so that 
2703  * information transfer routine can exit cleanly.
2704  */
2705
2706         if (hostdata->connected == cmd) {
2707                 dprintk(NDEBUG_ABORT, ("scsi%d : aborting connected command\n", instance->host_no));
2708                 hostdata->aborted = 1;
2709 /*
2710  * We should perform BSY checking, and make sure we haven't slipped
2711  * into BUS FREE.
2712  */
2713
2714                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN);
2715 /* 
2716  * Since we can't change phases until we've completed the current 
2717  * handshake, we have to source or sink a byte of data if the current
2718  * phase is not MSGOUT.
2719  */
2720
2721 /* 
2722  * Return control to the executing NCR drive so we can clear the
2723  * aborted flag and get back into our main loop.
2724  */
2725
2726                 return 0;
2727         }
2728 #endif
2729
2730 /* 
2731  * Case 2 : If the command hasn't been issued yet, we simply remove it 
2732  *          from the issue queue.
2733  */
2734  
2735         dprintk(NDEBUG_ABORT, ("scsi%d : abort going into loop.\n", instance->host_no));
2736         for (prev = (Scsi_Cmnd **) & (hostdata->issue_queue), tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp; prev = (Scsi_Cmnd **) & (tmp->host_scribble), tmp = (Scsi_Cmnd *) tmp->host_scribble)
2737                 if (cmd == tmp) {
2738                         REMOVE(5, *prev, tmp, tmp->host_scribble);
2739                         (*prev) = (Scsi_Cmnd *) tmp->host_scribble;
2740                         tmp->host_scribble = NULL;
2741                         tmp->result = DID_ABORT << 16;
2742                         dprintk(NDEBUG_ABORT, ("scsi%d : abort removed command from issue queue.\n", instance->host_no));
2743                         tmp->done(tmp);
2744                         return SUCCESS;
2745                 }
2746 #if (NDEBUG  & NDEBUG_ABORT)
2747         /* KLL */
2748                 else if (prev == tmp)
2749                         printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
2750 #endif
2751
2752 /* 
2753  * Case 3 : If any commands are connected, we're going to fail the abort
2754  *          and let the high level SCSI driver retry at a later time or 
2755  *          issue a reset.
2756  *
2757  *          Timeouts, and therefore aborted commands, will be highly unlikely
2758  *          and handling them cleanly in this situation would make the common
2759  *          case of noresets less efficient, and would pollute our code.  So,
2760  *          we fail.
2761  */
2762
2763         if (hostdata->connected) {
2764                 dprintk(NDEBUG_ABORT, ("scsi%d : abort failed, command connected.\n", instance->host_no));
2765                 return FAILED;
2766         }
2767 /*
2768  * Case 4: If the command is currently disconnected from the bus, and 
2769  *      there are no connected commands, we reconnect the I_T_L or 
2770  *      I_T_L_Q nexus associated with it, go into message out, and send 
2771  *      an abort message.
2772  *
2773  * This case is especially ugly. In order to reestablish the nexus, we
2774  * need to call NCR5380_select().  The easiest way to implement this 
2775  * function was to abort if the bus was busy, and let the interrupt
2776  * handler triggered on the SEL for reselect take care of lost arbitrations
2777  * where necessary, meaning interrupts need to be enabled.
2778  *
2779  * When interrupts are enabled, the queues may change - so we 
2780  * can't remove it from the disconnected queue before selecting it
2781  * because that could cause a failure in hashing the nexus if that 
2782  * device reselected.
2783  * 
2784  * Since the queues may change, we can't use the pointers from when we
2785  * first locate it.
2786  *
2787  * So, we must first locate the command, and if NCR5380_select()
2788  * succeeds, then issue the abort, relocate the command and remove
2789  * it from the disconnected queue.
2790  */
2791
2792         for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; tmp = (Scsi_Cmnd *) tmp->host_scribble)
2793                 if (cmd == tmp) {
2794                         dprintk(NDEBUG_ABORT, ("scsi%d : aborting disconnected command.\n", instance->host_no));
2795
2796                         if (NCR5380_select(instance, cmd, (int) cmd->tag))
2797                                 return FAILED;
2798                         dprintk(NDEBUG_ABORT, ("scsi%d : nexus reestablished.\n", instance->host_no));
2799
2800                         do_abort(instance);
2801
2802                         for (prev = (Scsi_Cmnd **) & (hostdata->disconnected_queue), tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; prev = (Scsi_Cmnd **) & (tmp->host_scribble), tmp = (Scsi_Cmnd *) tmp->host_scribble)
2803                                 if (cmd == tmp) {
2804                                         REMOVE(5, *prev, tmp, tmp->host_scribble);
2805                                         *prev = (Scsi_Cmnd *) tmp->host_scribble;
2806                                         tmp->host_scribble = NULL;
2807                                         tmp->result = DID_ABORT << 16;
2808                                         tmp->done(tmp);
2809                                         return SUCCESS;
2810                                 }
2811                 }
2812 /*
2813  * Case 5 : If we reached this point, the command was not found in any of 
2814  *          the queues.
2815  *
2816  * We probably reached this point because of an unlikely race condition
2817  * between the command completing successfully and the abortion code,
2818  * so we won't panic, but we will notify the user in case something really
2819  * broke.
2820  */
2821         printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
2822                         "         before abortion\n", instance->host_no);
2823         return FAILED;
2824 }
2825
2826
2827 /* 
2828  * Function : int NCR5380_bus_reset (Scsi_Cmnd *cmd)
2829  * 
2830  * Purpose : reset the SCSI bus.
2831  *
2832  * Returns : SUCCESS
2833  *
2834  * Locks: host lock taken by caller
2835  */
2836
2837 static int NCR5380_bus_reset(Scsi_Cmnd * cmd)
2838 {
2839         struct Scsi_Host *instance = cmd->device->host;
2840
2841         NCR5380_local_declare();
2842         NCR5380_setup(instance);
2843         NCR5380_print_status(instance);
2844
2845         spin_lock_irq(instance->host_lock);
2846         do_reset(instance);
2847         spin_unlock_irq(instance->host_lock);
2848
2849         return SUCCESS;
2850 }