Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb
[linux-2.6] / 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                         yield();
351                 else
352                         cpu_relax();
353         }
354         return -ETIMEDOUT;
355 }
356
357 static struct {
358         unsigned char value;
359         const char *name;
360 } phases[] = {
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 NCR5380_probe_irq(struct Scsi_Host *instance, int possible)
579 {
580         NCR5380_local_declare();
581         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
582         unsigned long timeout;
583         int trying_irqs, i, mask;
584         NCR5380_setup(instance);
585
586         for (trying_irqs = i = 0, mask = 1; i < 16; ++i, mask <<= 1)
587                 if ((mask & possible) && (request_irq(i, &probe_intr, IRQF_DISABLED, "NCR-probe", NULL) == 0))
588                         trying_irqs |= mask;
589
590         timeout = jiffies + (250 * HZ / 1000);
591         probe_irq = SCSI_IRQ_NONE;
592
593         /*
594          * A interrupt is triggered whenever BSY = false, SEL = true
595          * and a bit set in the SELECT_ENABLE_REG is asserted on the 
596          * SCSI bus.
597          *
598          * Note that the bus is only driven when the phase control signals
599          * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
600          * to zero.
601          */
602
603         NCR5380_write(TARGET_COMMAND_REG, 0);
604         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
605         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
606         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
607
608         while (probe_irq == SCSI_IRQ_NONE && time_before(jiffies, timeout))
609                 schedule_timeout_uninterruptible(1);
610         
611         NCR5380_write(SELECT_ENABLE_REG, 0);
612         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
613
614         for (i = 0, mask = 1; i < 16; ++i, mask <<= 1)
615                 if (trying_irqs & mask)
616                         free_irq(i, NULL);
617
618         return probe_irq;
619 }
620
621 /**
622  *      NCR58380_print_options  -       show options
623  *      @instance: unused for now
624  *
625  *      Called by probe code indicating the NCR5380 driver options that 
626  *      were selected. At some point this will switch to runtime options
627  *      read from the adapter in question
628  *
629  *      Locks: none
630  */
631
632 static void __init NCR5380_print_options(struct Scsi_Host *instance)
633 {
634         printk(" generic options"
635 #ifdef AUTOPROBE_IRQ
636                " AUTOPROBE_IRQ"
637 #endif
638 #ifdef AUTOSENSE
639                " AUTOSENSE"
640 #endif
641 #ifdef DIFFERENTIAL
642                " DIFFERENTIAL"
643 #endif
644 #ifdef REAL_DMA
645                " REAL DMA"
646 #endif
647 #ifdef REAL_DMA_POLL
648                " REAL DMA POLL"
649 #endif
650 #ifdef PARITY
651                " PARITY"
652 #endif
653 #ifdef PSEUDO_DMA
654                " PSEUDO DMA"
655 #endif
656 #ifdef UNSAFE
657                " UNSAFE "
658 #endif
659             );
660         printk(" USLEEP, USLEEP_POLL=%d USLEEP_SLEEP=%d", USLEEP_POLL, USLEEP_SLEEP);
661         printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
662         if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400) {
663                 printk(" ncr53c400 release=%d", NCR53C400_PUBLIC_RELEASE);
664         }
665 }
666
667 /**
668  *      NCR5380_print_status    -       dump controller info
669  *      @instance: controller to dump
670  *
671  *      Print commands in the various queues, called from NCR5380_abort 
672  *      and NCR5380_debug to aid debugging.
673  *
674  *      Locks: called functions disable irqs
675  */
676
677 static void NCR5380_print_status(struct Scsi_Host *instance)
678 {
679         NCR5380_dprint(NDEBUG_ANY, instance);
680         NCR5380_dprint_phase(NDEBUG_ANY, instance);
681 }
682
683 /******************************************/
684 /*
685  * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
686  *
687  * *buffer: I/O buffer
688  * **start: if inout == FALSE pointer into buffer where user read should start
689  * offset: current offset
690  * length: length of buffer
691  * hostno: Scsi_Host host_no
692  * inout: TRUE - user is writing; FALSE - user is reading
693  *
694  * Return the number of bytes read from or written
695  */
696
697 #undef SPRINTF
698 #define SPRINTF(args...) do { if(pos < buffer + length-80) pos += sprintf(pos, ## args); } while(0)
699 static
700 char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length);
701 static
702 char *lprint_command(unsigned char *cmd, char *pos, char *buffer, int len);
703 static
704 char *lprint_opcode(int opcode, char *pos, char *buffer, int length);
705
706 static
707 int NCR5380_proc_info(struct Scsi_Host *instance, char *buffer, char **start, off_t offset, int length, int inout)
708 {
709         char *pos = buffer;
710         struct NCR5380_hostdata *hostdata;
711         Scsi_Cmnd *ptr;
712
713         hostdata = (struct NCR5380_hostdata *) instance->hostdata;
714
715         if (inout) {            /* Has data been written to the file ? */
716 #ifdef DTC_PUBLIC_RELEASE
717                 dtc_wmaxi = dtc_maxi = 0;
718 #endif
719 #ifdef PAS16_PUBLIC_RELEASE
720                 pas_wmaxi = pas_maxi = 0;
721 #endif
722                 return (-ENOSYS);       /* Currently this is a no-op */
723         }
724         SPRINTF("NCR5380 core release=%d.   ", NCR5380_PUBLIC_RELEASE);
725         if (((struct NCR5380_hostdata *) instance->hostdata)->flags & FLAG_NCR53C400)
726                 SPRINTF("ncr53c400 release=%d.  ", NCR53C400_PUBLIC_RELEASE);
727 #ifdef DTC_PUBLIC_RELEASE
728         SPRINTF("DTC 3180/3280 release %d", DTC_PUBLIC_RELEASE);
729 #endif
730 #ifdef T128_PUBLIC_RELEASE
731         SPRINTF("T128 release %d", T128_PUBLIC_RELEASE);
732 #endif
733 #ifdef GENERIC_NCR5380_PUBLIC_RELEASE
734         SPRINTF("Generic5380 release %d", GENERIC_NCR5380_PUBLIC_RELEASE);
735 #endif
736 #ifdef PAS16_PUBLIC_RELEASE
737         SPRINTF("PAS16 release=%d", PAS16_PUBLIC_RELEASE);
738 #endif
739
740         SPRINTF("\nBase Addr: 0x%05lX    ", (long) instance->base);
741         SPRINTF("io_port: %04x      ", (int) instance->io_port);
742         if (instance->irq == SCSI_IRQ_NONE)
743                 SPRINTF("IRQ: None.\n");
744         else
745                 SPRINTF("IRQ: %d.\n", instance->irq);
746
747 #ifdef DTC_PUBLIC_RELEASE
748         SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", dtc_wmaxi, dtc_maxi);
749 #endif
750 #ifdef PAS16_PUBLIC_RELEASE
751         SPRINTF("Highwater I/O busy_spin_counts -- write: %d  read: %d\n", pas_wmaxi, pas_maxi);
752 #endif
753         spin_lock_irq(instance->host_lock);
754         if (!hostdata->connected)
755                 SPRINTF("scsi%d: no currently connected command\n", instance->host_no);
756         else
757                 pos = lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, pos, buffer, length);
758         SPRINTF("scsi%d: issue_queue\n", instance->host_no);
759         for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
760                 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
761
762         SPRINTF("scsi%d: disconnected_queue\n", instance->host_no);
763         for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; ptr = (Scsi_Cmnd *) ptr->host_scribble)
764                 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
765         spin_unlock_irq(instance->host_lock);
766         
767         *start = buffer;
768         if (pos - buffer < offset)
769                 return 0;
770         else if (pos - buffer - offset < length)
771                 return pos - buffer - offset;
772         return length;
773 }
774
775 static char *lprint_Scsi_Cmnd(Scsi_Cmnd * cmd, char *pos, char *buffer, int length)
776 {
777         SPRINTF("scsi%d : destination target %d, lun %d\n", cmd->device->host->host_no, cmd->device->id, cmd->device->lun);
778         SPRINTF("        command = ");
779         pos = lprint_command(cmd->cmnd, pos, buffer, length);
780         return (pos);
781 }
782
783 static char *lprint_command(unsigned char *command, char *pos, char *buffer, int length)
784 {
785         int i, s;
786         pos = lprint_opcode(command[0], pos, buffer, length);
787         for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
788                 SPRINTF("%02x ", command[i]);
789         SPRINTF("\n");
790         return (pos);
791 }
792
793 static char *lprint_opcode(int opcode, char *pos, char *buffer, int length)
794 {
795         SPRINTF("%2d (0x%02x)", opcode, opcode);
796         return (pos);
797 }
798
799
800 /**
801  *      NCR5380_init    -       initialise an NCR5380
802  *      @instance: adapter to configure
803  *      @flags: control flags
804  *
805  *      Initializes *instance and corresponding 5380 chip,
806  *      with flags OR'd into the initial flags value.
807  *
808  *      Notes : I assume that the host, hostno, and id bits have been
809  *      set correctly.  I don't care about the irq and other fields. 
810  *
811  *      Returns 0 for success
812  *
813  *      Locks: interrupts must be enabled when we are called 
814  */
815
816 static int __devinit NCR5380_init(struct Scsi_Host *instance, int flags)
817 {
818         NCR5380_local_declare();
819         int i, pass;
820         unsigned long timeout;
821         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
822
823         if(in_interrupt())
824                 printk(KERN_ERR "NCR5380_init called with interrupts off!\n");
825         /* 
826          * On NCR53C400 boards, NCR5380 registers are mapped 8 past 
827          * the base address.
828          */
829
830 #ifdef NCR53C400
831         if (flags & FLAG_NCR53C400)
832                 instance->NCR5380_instance_name += NCR53C400_address_adjust;
833 #endif
834
835         NCR5380_setup(instance);
836
837         hostdata->aborted = 0;
838         hostdata->id_mask = 1 << instance->this_id;
839         for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
840                 if (i > hostdata->id_mask)
841                         hostdata->id_higher_mask |= i;
842         for (i = 0; i < 8; ++i)
843                 hostdata->busy[i] = 0;
844 #ifdef REAL_DMA
845         hostdata->dmalen = 0;
846 #endif
847         hostdata->targets_present = 0;
848         hostdata->connected = NULL;
849         hostdata->issue_queue = NULL;
850         hostdata->disconnected_queue = NULL;
851         
852         INIT_WORK(&hostdata->coroutine, NCR5380_main, hostdata);
853         
854 #ifdef NCR5380_STATS
855         for (i = 0; i < 8; ++i) {
856                 hostdata->time_read[i] = 0;
857                 hostdata->time_write[i] = 0;
858                 hostdata->bytes_read[i] = 0;
859                 hostdata->bytes_write[i] = 0;
860         }
861         hostdata->timebase = 0;
862         hostdata->pendingw = 0;
863         hostdata->pendingr = 0;
864 #endif
865
866         /* The CHECK code seems to break the 53C400. Will check it later maybe */
867         if (flags & FLAG_NCR53C400)
868                 hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags;
869         else
870                 hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags;
871
872         hostdata->host = instance;
873         hostdata->time_expires = 0;
874
875 #ifndef AUTOSENSE
876         if ((instance->cmd_per_lun > 1) || instance->can_queue > 1)
877                     printk(KERN_WARNING "scsi%d : WARNING : support for multiple outstanding commands enabled\n" "         without AUTOSENSE option, contingent allegiance conditions may\n"
878                            "         be incorrectly cleared.\n", instance->host_no);
879 #endif                          /* def AUTOSENSE */
880
881         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
882         NCR5380_write(MODE_REG, MR_BASE);
883         NCR5380_write(TARGET_COMMAND_REG, 0);
884         NCR5380_write(SELECT_ENABLE_REG, 0);
885
886 #ifdef NCR53C400
887         if (hostdata->flags & FLAG_NCR53C400) {
888                 NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE);
889         }
890 #endif
891
892         /* 
893          * Detect and correct bus wedge problems.
894          *
895          * If the system crashed, it may have crashed in a state 
896          * where a SCSI command was still executing, and the 
897          * SCSI bus is not in a BUS FREE STATE.
898          *
899          * If this is the case, we'll try to abort the currently
900          * established nexus which we know nothing about, and that
901          * failing, do a hard reset of the SCSI bus 
902          */
903
904         for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
905                 switch (pass) {
906                 case 1:
907                 case 3:
908                 case 5:
909                         printk(KERN_INFO "scsi%d: SCSI bus busy, waiting up to five seconds\n", instance->host_no);
910                         timeout = jiffies + 5 * HZ;
911                         NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, 0, 5*HZ);
912                         break;
913                 case 2:
914                         printk(KERN_WARNING "scsi%d: bus busy, attempting abort\n", instance->host_no);
915                         do_abort(instance);
916                         break;
917                 case 4:
918                         printk(KERN_WARNING "scsi%d: bus busy, attempting reset\n", instance->host_no);
919                         do_reset(instance);
920                         break;
921                 case 6:
922                         printk(KERN_ERR "scsi%d: bus locked solid or invalid override\n", instance->host_no);
923                         return -ENXIO;
924                 }
925         }
926         return 0;
927 }
928
929 /**
930  *      NCR5380_exit    -       remove an NCR5380
931  *      @instance: adapter to remove
932  */
933
934 static void __devexit NCR5380_exit(struct Scsi_Host *instance)
935 {
936         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
937
938         cancel_delayed_work(&hostdata->coroutine);
939         flush_scheduled_work();
940 }
941
942 /**
943  *      NCR5380_queue_command           -       queue a command
944  *      @cmd: SCSI command
945  *      @done: completion handler
946  *
947  *      cmd is added to the per instance issue_queue, with minor 
948  *      twiddling done to the host specific fields of cmd.  If the 
949  *      main coroutine is not running, it is restarted.
950  *
951  *      Locks: host lock taken by caller
952  */
953
954 static int NCR5380_queue_command(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *)) 
955 {
956         struct Scsi_Host *instance = cmd->device->host;
957         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
958         Scsi_Cmnd *tmp;
959
960 #if (NDEBUG & NDEBUG_NO_WRITE)
961         switch (cmd->cmnd[0]) {
962         case WRITE_6:
963         case WRITE_10:
964                 printk("scsi%d : WRITE attempted with NO_WRITE debugging flag set\n", instance->host_no);
965                 cmd->result = (DID_ERROR << 16);
966                 done(cmd);
967                 return 0;
968         }
969 #endif                          /* (NDEBUG & NDEBUG_NO_WRITE) */
970
971 #ifdef NCR5380_STATS
972         switch (cmd->cmnd[0]) {
973                 case WRITE:
974                 case WRITE_6:
975                 case WRITE_10:
976                         hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
977                         hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen;
978                         hostdata->pendingw++;
979                         break;
980                 case READ:
981                 case READ_6:
982                 case READ_10:
983                         hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
984                         hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen;
985                         hostdata->pendingr++;
986                         break;
987         }
988 #endif
989
990         /* 
991          * We use the host_scribble field as a pointer to the next command  
992          * in a queue 
993          */
994
995         cmd->host_scribble = NULL;
996         cmd->scsi_done = done;
997         cmd->result = 0;
998
999         /* 
1000          * Insert the cmd into the issue queue. Note that REQUEST SENSE 
1001          * commands are added to the head of the queue since any command will
1002          * clear the contingent allegiance condition that exists and the 
1003          * sense data is only guaranteed to be valid while the condition exists.
1004          */
1005
1006         if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1007                 LIST(cmd, hostdata->issue_queue);
1008                 cmd->host_scribble = (unsigned char *) hostdata->issue_queue;
1009                 hostdata->issue_queue = cmd;
1010         } else {
1011                 for (tmp = (Scsi_Cmnd *) hostdata->issue_queue; tmp->host_scribble; tmp = (Scsi_Cmnd *) tmp->host_scribble);
1012                 LIST(cmd, tmp);
1013                 tmp->host_scribble = (unsigned char *) cmd;
1014         }
1015         dprintk(NDEBUG_QUEUES, ("scsi%d : command added to %s of queue\n", instance->host_no, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"));
1016
1017         /* Run the coroutine if it isn't already running. */
1018         /* Kick off command processing */
1019         schedule_work(&hostdata->coroutine);
1020         return 0;
1021 }
1022
1023
1024 /**
1025  *      NCR5380_main    -       NCR state machines
1026  *
1027  *      NCR5380_main is a coroutine that runs as long as more work can 
1028  *      be done on the NCR5380 host adapters in a system.  Both 
1029  *      NCR5380_queue_command() and NCR5380_intr() will try to start it 
1030  *      in case it is not running.
1031  * 
1032  *      Locks: called as its own thread with no locks held. Takes the
1033  *      host lock and called routines may take the isa dma lock.
1034  */
1035
1036 static void NCR5380_main(void *p)
1037 {
1038         struct NCR5380_hostdata *hostdata = p;
1039         struct Scsi_Host *instance = hostdata->host;
1040         Scsi_Cmnd *tmp, *prev;
1041         int done;
1042         
1043         spin_lock_irq(instance->host_lock);
1044         do {
1045                 /* Lock held here */
1046                 done = 1;
1047                 if (!hostdata->connected && !hostdata->selecting) {
1048                         dprintk(NDEBUG_MAIN, ("scsi%d : not connected\n", instance->host_no));
1049                         /*
1050                          * Search through the issue_queue for a command destined
1051                          * for a target that's not busy.
1052                          */
1053                         for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble) 
1054                         {
1055                                 if (prev != tmp)
1056                                         dprintk(NDEBUG_LISTS, ("MAIN tmp=%p   target=%d   busy=%d lun=%d\n", tmp, tmp->target, hostdata->busy[tmp->target], tmp->lun));
1057                                 /*  When we find one, remove it from the issue queue. */
1058                                 if (!(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))) {
1059                                         if (prev) {
1060                                                 REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
1061                                                 prev->host_scribble = tmp->host_scribble;
1062                                         } else {
1063                                                 REMOVE(-1, hostdata->issue_queue, tmp, tmp->host_scribble);
1064                                                 hostdata->issue_queue = (Scsi_Cmnd *) tmp->host_scribble;
1065                                         }
1066                                         tmp->host_scribble = NULL;
1067
1068                                         /* 
1069                                          * Attempt to establish an I_T_L nexus here. 
1070                                          * On success, instance->hostdata->connected is set.
1071                                          * On failure, we must add the command back to the
1072                                          *   issue queue so we can keep trying. 
1073                                          */
1074                                         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));
1075         
1076                                         /*
1077                                          * A successful selection is defined as one that 
1078                                          * leaves us with the command connected and 
1079                                          * in hostdata->connected, OR has terminated the
1080                                          * command.
1081                                          *
1082                                          * With successful commands, we fall through
1083                                          * and see if we can do an information transfer,
1084                                          * with failures we will restart.
1085                                          */
1086                                         hostdata->selecting = NULL;
1087                                         /* RvC: have to preset this to indicate a new command is being performed */
1088
1089                                         if (!NCR5380_select(instance, tmp,
1090                                                             /* 
1091                                                              * REQUEST SENSE commands are issued without tagged
1092                                                              * queueing, even on SCSI-II devices because the 
1093                                                              * contingent allegiance condition exists for the 
1094                                                              * entire unit.
1095                                                              */
1096                                                             (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1097                                                 break;
1098                                         } else {
1099                                                 LIST(tmp, hostdata->issue_queue);
1100                                                 tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1101                                                 hostdata->issue_queue = tmp;
1102                                                 done = 0;
1103                                                 dprintk(NDEBUG_MAIN|NDEBUG_QUEUES, ("scsi%d : main(): select() failed, returned to issue_queue\n", instance->host_no));
1104                                         }
1105                                         /* lock held here still */
1106                                 }       /* if target/lun is not busy */
1107                         }       /* for */
1108                         /* exited locked */
1109                 }       /* if (!hostdata->connected) */
1110                 if (hostdata->selecting) {
1111                         tmp = (Scsi_Cmnd *) hostdata->selecting;
1112                         /* Selection will drop and retake the lock */
1113                         if (!NCR5380_select(instance, tmp, (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : TAG_NEXT)) {
1114                                 /* Ok ?? */
1115                         } else {
1116                                 /* RvC: device failed, so we wait a long time
1117                                    this is needed for Mustek scanners, that
1118                                    do not respond to commands immediately
1119                                    after a scan */
1120                                 printk(KERN_DEBUG "scsi%d: device %d did not respond in time\n", instance->host_no, tmp->device->id);
1121                                 LIST(tmp, hostdata->issue_queue);
1122                                 tmp->host_scribble = (unsigned char *) hostdata->issue_queue;
1123                                 hostdata->issue_queue = tmp;
1124                                 NCR5380_set_timer(hostdata, USLEEP_WAITLONG);
1125                         }
1126                 }       /* if hostdata->selecting */
1127                 if (hostdata->connected
1128 #ifdef REAL_DMA
1129                     && !hostdata->dmalen
1130 #endif
1131                     && (!hostdata->time_expires || time_before_eq(hostdata->time_expires, jiffies))
1132                     ) {
1133                         dprintk(NDEBUG_MAIN, ("scsi%d : main() : performing information transfer\n", instance->host_no));
1134                         NCR5380_information_transfer(instance);
1135                         dprintk(NDEBUG_MAIN, ("scsi%d : main() : done set false\n", instance->host_no));
1136                         done = 0;
1137                 } else
1138                         break;
1139         } while (!done);
1140         
1141         spin_unlock_irq(instance->host_lock);
1142 }
1143
1144 #ifndef DONT_USE_INTR
1145
1146 /**
1147  *      NCR5380_intr    -       generic NCR5380 irq handler
1148  *      @irq: interrupt number
1149  *      @dev_id: device info
1150  *
1151  *      Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1152  *      from the disconnected queue, and restarting NCR5380_main() 
1153  *      as required.
1154  *
1155  *      Locks: takes the needed instance locks
1156  */
1157
1158 static irqreturn_t NCR5380_intr(int irq, void *dev_id) 
1159 {
1160         NCR5380_local_declare();
1161         struct Scsi_Host *instance = (struct Scsi_Host *)dev_id;
1162         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1163         int done;
1164         unsigned char basr;
1165         unsigned long flags;
1166
1167         dprintk(NDEBUG_INTR, ("scsi : NCR5380 irq %d triggered\n", irq));
1168
1169         do {
1170                 done = 1;
1171                 spin_lock_irqsave(instance->host_lock, flags);
1172                 /* Look for pending interrupts */
1173                 NCR5380_setup(instance);
1174                 basr = NCR5380_read(BUS_AND_STATUS_REG);
1175                 /* XXX dispatch to appropriate routine if found and done=0 */
1176                 if (basr & BASR_IRQ) {
1177                         NCR5380_dprint(NDEBUG_INTR, instance);
1178                         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1179                                 done = 0;
1180                                 dprintk(NDEBUG_INTR, ("scsi%d : SEL interrupt\n", instance->host_no));
1181                                 NCR5380_reselect(instance);
1182                                 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1183                         } else if (basr & BASR_PARITY_ERROR) {
1184                                 dprintk(NDEBUG_INTR, ("scsi%d : PARITY interrupt\n", instance->host_no));
1185                                 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1186                         } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1187                                 dprintk(NDEBUG_INTR, ("scsi%d : RESET interrupt\n", instance->host_no));
1188                                 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1189                         } else {
1190 #if defined(REAL_DMA)
1191                                 /*
1192                                  * We should only get PHASE MISMATCH and EOP interrupts
1193                                  * if we have DMA enabled, so do a sanity check based on
1194                                  * the current setting of the MODE register.
1195                                  */
1196
1197                                 if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr & BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
1198                                         int transfered;
1199
1200                                         if (!hostdata->connected)
1201                                                 panic("scsi%d : received end of DMA interrupt with no connected cmd\n", instance->hostno);
1202
1203                                         transfered = (hostdata->dmalen - NCR5380_dma_residual(instance));
1204                                         hostdata->connected->SCp.this_residual -= transferred;
1205                                         hostdata->connected->SCp.ptr += transferred;
1206                                         hostdata->dmalen = 0;
1207
1208                                         (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1209                                                         
1210                                         /* FIXME: we need to poll briefly then defer a workqueue task ! */
1211                                         NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
1212
1213                                         NCR5380_write(MODE_REG, MR_BASE);
1214                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1215                                 }
1216 #else
1217                                 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)));
1218                                 (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1219 #endif
1220                         }
1221                 }       /* if BASR_IRQ */
1222                 spin_unlock_irqrestore(instance->host_lock, flags);
1223                 if(!done)
1224                         schedule_work(&hostdata->coroutine);
1225         } while (!done);
1226         return IRQ_HANDLED;
1227 }
1228
1229 #endif 
1230
1231 /**
1232  *      collect_stats           -       collect stats on a scsi command
1233  *      @hostdata: adapter 
1234  *      @cmd: command being issued
1235  *
1236  *      Update the statistical data by parsing the command in question
1237  */
1238  
1239 static void collect_stats(struct NCR5380_hostdata *hostdata, Scsi_Cmnd * cmd) 
1240 {
1241 #ifdef NCR5380_STATS
1242         switch (cmd->cmnd[0]) {
1243         case WRITE:
1244         case WRITE_6:
1245         case WRITE_10:
1246                 hostdata->time_write[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1247                 hostdata->pendingw--;
1248                 break;
1249         case READ:
1250         case READ_6:
1251         case READ_10:
1252                 hostdata->time_read[scmd_id(cmd)] += (jiffies - hostdata->timebase);
1253                 hostdata->pendingr--;
1254                 break;
1255         }
1256 #endif
1257 }
1258
1259
1260 /* 
1261  * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd, 
1262  *      int tag);
1263  *
1264  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1265  *      including ARBITRATION, SELECTION, and initial message out for 
1266  *      IDENTIFY and queue messages. 
1267  *
1268  * Inputs : instance - instantiation of the 5380 driver on which this 
1269  *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for 
1270  *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for 
1271  *      the command that is presently connected.
1272  * 
1273  * Returns : -1 if selection could not execute for some reason,
1274  *      0 if selection succeeded or failed because the target 
1275  *      did not respond.
1276  *
1277  * Side effects : 
1278  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit 
1279  *              with registers as they should have been on entry - ie
1280  *              SELECT_ENABLE will be set appropriately, the NCR5380
1281  *              will cease to drive any SCSI bus signals.
1282  *
1283  *      If successful : I_T_L or I_T_L_Q nexus will be established, 
1284  *              instance->connected will be set to cmd.  
1285  *              SELECT interrupt will be disabled.
1286  *
1287  *      If failed (no target) : cmd->scsi_done() will be called, and the 
1288  *              cmd->result host byte set to DID_BAD_TARGET.
1289  *
1290  *      Locks: caller holds hostdata lock in IRQ mode
1291  */
1292  
1293 static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd * cmd, int tag) 
1294 {
1295         NCR5380_local_declare();
1296         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1297         unsigned char tmp[3], phase;
1298         unsigned char *data;
1299         int len;
1300         unsigned long timeout;
1301         unsigned char value;
1302         int err;
1303         NCR5380_setup(instance);
1304
1305         if (hostdata->selecting)
1306                 goto part2;
1307
1308         hostdata->restart_select = 0;
1309
1310         NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1311         dprintk(NDEBUG_ARBITRATION, ("scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id));
1312
1313         /* 
1314          * Set the phase bits to 0, otherwise the NCR5380 won't drive the 
1315          * data bus during SELECTION.
1316          */
1317
1318         NCR5380_write(TARGET_COMMAND_REG, 0);
1319
1320         /* 
1321          * Start arbitration.
1322          */
1323
1324         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1325         NCR5380_write(MODE_REG, MR_ARBITRATE);
1326
1327
1328         /* We can be relaxed here, interrupts are on, we are
1329            in workqueue context, the birds are singing in the trees */
1330         spin_unlock_irq(instance->host_lock);
1331         err = NCR5380_poll_politely(instance, INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, ICR_ARBITRATION_PROGRESS, 5*HZ);
1332         spin_lock_irq(instance->host_lock);
1333         if (err < 0) {
1334                 printk(KERN_DEBUG "scsi: arbitration timeout at %d\n", __LINE__);
1335                 NCR5380_write(MODE_REG, MR_BASE);
1336                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1337                 goto failed;
1338         }
1339
1340         dprintk(NDEBUG_ARBITRATION, ("scsi%d : arbitration complete\n", instance->host_no));
1341
1342         /* 
1343          * The arbitration delay is 2.2us, but this is a minimum and there is 
1344          * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1345          * the integral nature of udelay().
1346          *
1347          */
1348
1349         udelay(3);
1350
1351         /* Check for lost arbitration */
1352         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)) {
1353                 NCR5380_write(MODE_REG, MR_BASE);
1354                 dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting MR_ARBITRATE\n", instance->host_no));
1355                 goto failed;
1356         }
1357         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL);
1358
1359         if (!(hostdata->flags & FLAG_DTC3181E) &&
1360             /* RvC: DTC3181E has some trouble with this
1361              *      so we simply removed it. Seems to work with
1362              *      only Mustek scanner attached
1363              */
1364             (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1365                 NCR5380_write(MODE_REG, MR_BASE);
1366                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1367                 dprintk(NDEBUG_ARBITRATION, ("scsi%d : lost arbitration, deasserting ICR_ASSERT_SEL\n", instance->host_no));
1368                 goto failed;
1369         }
1370         /* 
1371          * Again, bus clear + bus settle time is 1.2us, however, this is 
1372          * a minimum so we'll udelay ceil(1.2)
1373          */
1374
1375         udelay(2);
1376
1377         dprintk(NDEBUG_ARBITRATION, ("scsi%d : won arbitration\n", instance->host_no));
1378
1379         /* 
1380          * Now that we have won arbitration, start Selection process, asserting 
1381          * the host and target ID's on the SCSI bus.
1382          */
1383
1384         NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << scmd_id(cmd))));
1385
1386         /* 
1387          * Raise ATN while SEL is true before BSY goes false from arbitration,
1388          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1389          * phase immediately after selection.
1390          */
1391
1392         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1393         NCR5380_write(MODE_REG, MR_BASE);
1394
1395         /* 
1396          * Reselect interrupts must be turned off prior to the dropping of BSY,
1397          * otherwise we will trigger an interrupt.
1398          */
1399         NCR5380_write(SELECT_ENABLE_REG, 0);
1400
1401         /*
1402          * The initiator shall then wait at least two deskew delays and release 
1403          * the BSY signal.
1404          */
1405         udelay(1);              /* wingel -- wait two bus deskew delay >2*45ns */
1406
1407         /* Reset BSY */
1408         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1409
1410         /* 
1411          * Something weird happens when we cease to drive BSY - looks
1412          * like the board/chip is letting us do another read before the 
1413          * appropriate propagation delay has expired, and we're confusing
1414          * a BSY signal from ourselves as the target's response to SELECTION.
1415          *
1416          * A small delay (the 'C++' frontend breaks the pipeline with an
1417          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1418          * tighter 'C' code breaks and requires this) solves the problem - 
1419          * the 1 us delay is arbitrary, and only used because this delay will 
1420          * be the same on other platforms and since it works here, it should 
1421          * work there.
1422          *
1423          * wingel suggests that this could be due to failing to wait
1424          * one deskew delay.
1425          */
1426
1427         udelay(1);
1428
1429         dprintk(NDEBUG_SELECTION, ("scsi%d : selecting target %d\n", instance->host_no, scmd_id(cmd)));
1430
1431         /* 
1432          * The SCSI specification calls for a 250 ms timeout for the actual 
1433          * selection.
1434          */
1435
1436         timeout = jiffies + (250 * HZ / 1000);
1437
1438         /* 
1439          * XXX very interesting - we're seeing a bounce where the BSY we 
1440          * asserted is being reflected / still asserted (propagation delay?)
1441          * and it's detecting as true.  Sigh.
1442          */
1443
1444         hostdata->select_time = 0;      /* we count the clock ticks at which we polled */
1445         hostdata->selecting = cmd;
1446
1447 part2:
1448         /* RvC: here we enter after a sleeping period, or immediately after
1449            execution of part 1
1450            we poll only once ech clock tick */
1451         value = NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO);
1452
1453         if (!value && (hostdata->select_time < HZ/4)) {
1454                 /* RvC: we still must wait for a device response */
1455                 hostdata->select_time++;        /* after 25 ticks the device has failed */
1456                 NCR5380_set_timer(hostdata, 1);
1457                 return 0;       /* RvC: we return here with hostdata->selecting set,
1458                                    to go to sleep */
1459         }
1460
1461         hostdata->selecting = NULL;/* clear this pointer, because we passed the
1462                                            waiting period */
1463         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1464                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1465                 NCR5380_reselect(instance);
1466                 printk("scsi%d : reselection after won arbitration?\n", instance->host_no);
1467                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1468                 return -1;
1469         }
1470         /* 
1471          * No less than two deskew delays after the initiator detects the 
1472          * BSY signal is true, it shall release the SEL signal and may 
1473          * change the DATA BUS.                                     -wingel
1474          */
1475
1476         udelay(1);
1477
1478         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1479
1480         if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1481                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1482                 if (hostdata->targets_present & (1 << scmd_id(cmd))) {
1483                         printk(KERN_DEBUG "scsi%d : weirdness\n", instance->host_no);
1484                         if (hostdata->restart_select)
1485                                 printk(KERN_DEBUG "\trestart select\n");
1486                         NCR5380_dprint(NDEBUG_SELECTION, instance);
1487                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1488                         return -1;
1489                 }
1490                 cmd->result = DID_BAD_TARGET << 16;
1491                 collect_stats(hostdata, cmd);
1492                 cmd->scsi_done(cmd);
1493                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1494                 dprintk(NDEBUG_SELECTION, ("scsi%d : target did not respond within 250ms\n", instance->host_no));
1495                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1496                 return 0;
1497         }
1498         hostdata->targets_present |= (1 << scmd_id(cmd));
1499
1500         /*
1501          * Since we followed the SCSI spec, and raised ATN while SEL 
1502          * was true but before BSY was false during selection, the information
1503          * transfer phase should be a MESSAGE OUT phase so that we can send the
1504          * IDENTIFY message.
1505          * 
1506          * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1507          * message (2 bytes) with a tag ID that we increment with every command
1508          * until it wraps back to 0.
1509          *
1510          * XXX - it turns out that there are some broken SCSI-II devices,
1511          *       which claim to support tagged queuing but fail when more than
1512          *       some number of commands are issued at once.
1513          */
1514
1515         /* Wait for start of REQ/ACK handshake */
1516
1517         spin_unlock_irq(instance->host_lock);
1518         err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1519         spin_lock_irq(instance->host_lock);
1520         
1521         if(err) {
1522                 printk(KERN_ERR "scsi%d: timeout at NCR5380.c:%d\n", instance->host_no, __LINE__);
1523                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1524                 goto failed;
1525         }
1526
1527         dprintk(NDEBUG_SELECTION, ("scsi%d : target %d selected, going into MESSAGE OUT phase.\n", instance->host_no, cmd->device->id));
1528         tmp[0] = IDENTIFY(((instance->irq == SCSI_IRQ_NONE) ? 0 : 1), cmd->device->lun);
1529
1530         len = 1;
1531         cmd->tag = 0;
1532
1533         /* Send message(s) */
1534         data = tmp;
1535         phase = PHASE_MSGOUT;
1536         NCR5380_transfer_pio(instance, &phase, &len, &data);
1537         dprintk(NDEBUG_SELECTION, ("scsi%d : nexus established.\n", instance->host_no));
1538         /* XXX need to handle errors here */
1539         hostdata->connected = cmd;
1540         hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1541
1542         if (cmd->SCp.ptr != (char *)cmd->sense_buffer) {
1543                 initialize_SCp(cmd);
1544         }
1545
1546         return 0;
1547
1548         /* Selection failed */
1549 failed:
1550         return -1;
1551
1552 }
1553
1554 /* 
1555  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance, 
1556  *      unsigned char *phase, int *count, unsigned char **data)
1557  *
1558  * Purpose : transfers data in given phase using polled I/O
1559  *
1560  * Inputs : instance - instance of driver, *phase - pointer to 
1561  *      what phase is expected, *count - pointer to number of 
1562  *      bytes to transfer, **data - pointer to data pointer.
1563  * 
1564  * Returns : -1 when different phase is entered without transferring
1565  *      maximum number of bytes, 0 if all bytes or transfered or exit
1566  *      is in same phase.
1567  *
1568  *      Also, *phase, *count, *data are modified in place.
1569  *
1570  * XXX Note : handling for bus free may be useful.
1571  */
1572
1573 /*
1574  * Note : this code is not as quick as it could be, however it 
1575  * IS 100% reliable, and for the actual data transfer where speed
1576  * counts, we will always do a pseudo DMA or DMA transfer.
1577  */
1578
1579 static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1580         NCR5380_local_declare();
1581         unsigned char p = *phase, tmp;
1582         int c = *count;
1583         unsigned char *d = *data;
1584         /*
1585          *      RvC: some administrative data to process polling time
1586          */
1587         int break_allowed = 0;
1588         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1589         NCR5380_setup(instance);
1590
1591         if (!(p & SR_IO))
1592                 dprintk(NDEBUG_PIO, ("scsi%d : pio write %d bytes\n", instance->host_no, c));
1593         else
1594                 dprintk(NDEBUG_PIO, ("scsi%d : pio read %d bytes\n", instance->host_no, c));
1595
1596         /* 
1597          * The NCR5380 chip will only drive the SCSI bus when the 
1598          * phase specified in the appropriate bits of the TARGET COMMAND
1599          * REGISTER match the STATUS REGISTER
1600          */
1601
1602          NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1603
1604         /* RvC: don't know if this is necessary, but other SCSI I/O is short
1605          *      so breaks are not necessary there
1606          */
1607         if ((p == PHASE_DATAIN) || (p == PHASE_DATAOUT)) {
1608                 break_allowed = 1;
1609         }
1610         do {
1611                 /* 
1612                  * Wait for assertion of REQ, after which the phase bits will be 
1613                  * valid 
1614                  */
1615
1616                 /* RvC: we simply poll once, after that we stop temporarily
1617                  *      and let the device buffer fill up
1618                  *      if breaking is not allowed, we keep polling as long as needed
1619                  */
1620
1621                 /* FIXME */
1622                 while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ) && !break_allowed);
1623                 if (!(tmp & SR_REQ)) {
1624                         /* timeout condition */
1625                         NCR5380_set_timer(hostdata, USLEEP_SLEEP);
1626                         break;
1627                 }
1628
1629                 dprintk(NDEBUG_HANDSHAKE, ("scsi%d : REQ detected\n", instance->host_no));
1630
1631                 /* Check for phase mismatch */
1632                 if ((tmp & PHASE_MASK) != p) {
1633                         dprintk(NDEBUG_HANDSHAKE, ("scsi%d : phase mismatch\n", instance->host_no));
1634                         NCR5380_dprint_phase(NDEBUG_HANDSHAKE, instance);
1635                         break;
1636                 }
1637                 /* Do actual transfer from SCSI bus to / from memory */
1638                 if (!(p & SR_IO))
1639                         NCR5380_write(OUTPUT_DATA_REG, *d);
1640                 else
1641                         *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1642
1643                 ++d;
1644
1645                 /* 
1646                  * The SCSI standard suggests that in MSGOUT phase, the initiator
1647                  * should drop ATN on the last byte of the message phase
1648                  * after REQ has been asserted for the handshake but before
1649                  * the initiator raises ACK.
1650                  */
1651
1652                 if (!(p & SR_IO)) {
1653                         if (!((p & SR_MSG) && c > 1)) {
1654                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1655                                 NCR5380_dprint(NDEBUG_PIO, instance);
1656                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1657                         } else {
1658                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1659                                 NCR5380_dprint(NDEBUG_PIO, instance);
1660                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1661                         }
1662                 } else {
1663                         NCR5380_dprint(NDEBUG_PIO, instance);
1664                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1665                 }
1666
1667                 /* FIXME - if this fails bus reset ?? */
1668                 NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 5*HZ);
1669                 dprintk(NDEBUG_HANDSHAKE, ("scsi%d : req false, handshake complete\n", instance->host_no));
1670
1671 /*
1672  * We have several special cases to consider during REQ/ACK handshaking : 
1673  * 1.  We were in MSGOUT phase, and we are on the last byte of the 
1674  *      message.  ATN must be dropped as ACK is dropped.
1675  *
1676  * 2.  We are in a MSGIN phase, and we are on the last byte of the  
1677  *      message.  We must exit with ACK asserted, so that the calling
1678  *      code may raise ATN before dropping ACK to reject the message.
1679  *
1680  * 3.  ACK and ATN are clear and the target may proceed as normal.
1681  */
1682                 if (!(p == PHASE_MSGIN && c == 1)) {
1683                         if (p == PHASE_MSGOUT && c > 1)
1684                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1685                         else
1686                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1687                 }
1688         } while (--c);
1689
1690         dprintk(NDEBUG_PIO, ("scsi%d : residual %d\n", instance->host_no, c));
1691
1692         *count = c;
1693         *data = d;
1694         tmp = NCR5380_read(STATUS_REG);
1695         if (tmp & SR_REQ)
1696                 *phase = tmp & PHASE_MASK;
1697         else
1698                 *phase = PHASE_UNKNOWN;
1699
1700         if (!c || (*phase == p))
1701                 return 0;
1702         else
1703                 return -1;
1704 }
1705
1706 /**
1707  *      do_reset        -       issue a reset command
1708  *      @host: adapter to reset
1709  *
1710  *      Issue a reset sequence to the NCR5380 and try and get the bus
1711  *      back into sane shape.
1712  *
1713  *      Locks: caller holds queue lock
1714  */
1715  
1716 static void do_reset(struct Scsi_Host *host) {
1717         NCR5380_local_declare();
1718         NCR5380_setup(host);
1719
1720         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1721         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1722         udelay(25);
1723         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1724 }
1725
1726 /*
1727  * Function : do_abort (Scsi_Host *host)
1728  * 
1729  * Purpose : abort the currently established nexus.  Should only be 
1730  *      called from a routine which can drop into a 
1731  * 
1732  * Returns : 0 on success, -1 on failure.
1733  *
1734  * Locks: queue lock held by caller
1735  *      FIXME: sort this out and get new_eh running
1736  */
1737
1738 static int do_abort(struct Scsi_Host *host) {
1739         NCR5380_local_declare();
1740         unsigned char *msgptr, phase, tmp;
1741         int len;
1742         int rc;
1743         NCR5380_setup(host);
1744
1745
1746         /* Request message out phase */
1747         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1748
1749         /* 
1750          * Wait for the target to indicate a valid phase by asserting 
1751          * REQ.  Once this happens, we'll have either a MSGOUT phase 
1752          * and can immediately send the ABORT message, or we'll have some 
1753          * other phase and will have to source/sink data.
1754          * 
1755          * We really don't care what value was on the bus or what value
1756          * the target sees, so we just handshake.
1757          */
1758
1759         rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, SR_REQ, 60 * HZ);
1760         
1761         if(rc < 0)
1762                 return -1;
1763
1764         tmp = (unsigned char)rc;
1765         
1766         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1767
1768         if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1769                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1770                 rc = NCR5380_poll_politely(host, STATUS_REG, SR_REQ, 0, 3*HZ);
1771                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1772                 if(rc == -1)
1773                         return -1;
1774         }
1775         tmp = ABORT;
1776         msgptr = &tmp;
1777         len = 1;
1778         phase = PHASE_MSGOUT;
1779         NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1780
1781         /*
1782          * If we got here, and the command completed successfully,
1783          * we're about to go into bus free state.
1784          */
1785
1786         return len ? -1 : 0;
1787 }
1788
1789 #if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1790 /* 
1791  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance, 
1792  *      unsigned char *phase, int *count, unsigned char **data)
1793  *
1794  * Purpose : transfers data in given phase using either real
1795  *      or pseudo DMA.
1796  *
1797  * Inputs : instance - instance of driver, *phase - pointer to 
1798  *      what phase is expected, *count - pointer to number of 
1799  *      bytes to transfer, **data - pointer to data pointer.
1800  * 
1801  * Returns : -1 when different phase is entered without transferring
1802  *      maximum number of bytes, 0 if all bytes or transfered or exit
1803  *      is in same phase.
1804  *
1805  *      Also, *phase, *count, *data are modified in place.
1806  *
1807  *      Locks: io_request lock held by caller
1808  */
1809
1810
1811 static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1812         NCR5380_local_declare();
1813         register int c = *count;
1814         register unsigned char p = *phase;
1815         register unsigned char *d = *data;
1816         unsigned char tmp;
1817         int foo;
1818 #if defined(REAL_DMA_POLL)
1819         int cnt, toPIO;
1820         unsigned char saved_data = 0, overrun = 0, residue;
1821 #endif
1822
1823         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
1824
1825         NCR5380_setup(instance);
1826
1827         if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1828                 *phase = tmp;
1829                 return -1;
1830         }
1831 #if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1832 #ifdef READ_OVERRUNS
1833         if (p & SR_IO) {
1834                 c -= 2;
1835         }
1836 #endif
1837         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));
1838         hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1839 #endif
1840
1841         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1842
1843 #ifdef REAL_DMA
1844         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1845 #elif defined(REAL_DMA_POLL)
1846         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1847 #else
1848         /*
1849          * Note : on my sample board, watch-dog timeouts occurred when interrupts
1850          * were not disabled for the duration of a single DMA transfer, from 
1851          * before the setting of DMA mode to after transfer of the last byte.
1852          */
1853
1854 #if defined(PSEUDO_DMA) && defined(UNSAFE)
1855         spin_unlock_irq(instance->host_lock);
1856 #endif
1857         /* KLL May need eop and parity in 53c400 */
1858         if (hostdata->flags & FLAG_NCR53C400)
1859                 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);
1860         else
1861                 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE);
1862 #endif                          /* def REAL_DMA */
1863
1864         dprintk(NDEBUG_DMA, ("scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG)));
1865
1866         /* 
1867          *      On the PAS16 at least I/O recovery delays are not needed here.
1868          *      Everyone else seems to want them.
1869          */
1870
1871         if (p & SR_IO) {
1872                 io_recovery_delay(1);
1873                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1874         } else {
1875                 io_recovery_delay(1);
1876                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1877                 io_recovery_delay(1);
1878                 NCR5380_write(START_DMA_SEND_REG, 0);
1879                 io_recovery_delay(1);
1880         }
1881
1882 #if defined(REAL_DMA_POLL)
1883         do {
1884                 tmp = NCR5380_read(BUS_AND_STATUS_REG);
1885         } while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1886
1887 /*
1888    At this point, either we've completed DMA, or we have a phase mismatch,
1889    or we've unexpectedly lost BUSY (which is a real error).
1890
1891    For write DMAs, we want to wait until the last byte has been
1892    transferred out over the bus before we turn off DMA mode.  Alas, there
1893    seems to be no terribly good way of doing this on a 5380 under all
1894    conditions.  For non-scatter-gather operations, we can wait until REQ
1895    and ACK both go false, or until a phase mismatch occurs.  Gather-writes
1896    are nastier, since the device will be expecting more data than we
1897    are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
1898    could test LAST BIT SENT to assure transfer (I imagine this is precisely
1899    why this signal was added to the newer chips) but on the older 538[01]
1900    this signal does not exist.  The workaround for this lack is a watchdog;
1901    we bail out of the wait-loop after a modest amount of wait-time if
1902    the usual exit conditions are not met.  Not a terribly clean or
1903    correct solution :-%
1904
1905    Reads are equally tricky due to a nasty characteristic of the NCR5380.
1906    If the chip is in DMA mode for an READ, it will respond to a target's
1907    REQ by latching the SCSI data into the INPUT DATA register and asserting
1908    ACK, even if it has _already_ been notified by the DMA controller that
1909    the current DMA transfer has completed!  If the NCR5380 is then taken
1910    out of DMA mode, this already-acknowledged byte is lost.
1911
1912    This is not a problem for "one DMA transfer per command" reads, because
1913    the situation will never arise... either all of the data is DMA'ed
1914    properly, or the target switches to MESSAGE IN phase to signal a
1915    disconnection (either operation bringing the DMA to a clean halt).
1916    However, in order to handle scatter-reads, we must work around the
1917    problem.  The chosen fix is to DMA N-2 bytes, then check for the
1918    condition before taking the NCR5380 out of DMA mode.  One or two extra
1919    bytes are transferred via PIO as necessary to fill out the original
1920    request.
1921  */
1922
1923         if (p & SR_IO) {
1924 #ifdef READ_OVERRUNS
1925                 udelay(10);
1926                 if (((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) == (BASR_PHASE_MATCH | BASR_ACK))) {
1927                         saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1928                         overrun = 1;
1929                 }
1930 #endif
1931         } else {
1932                 int limit = 100;
1933                 while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1934                         if (!(tmp & BASR_PHASE_MATCH))
1935                                 break;
1936                         if (--limit < 0)
1937                                 break;
1938                 }
1939         }
1940
1941         dprintk(NDEBUG_DMA, ("scsi%d : polled DMA transfer complete, basr 0x%X, sr 0x%X\n", instance->host_no, tmp, NCR5380_read(STATUS_REG)));
1942
1943         NCR5380_write(MODE_REG, MR_BASE);
1944         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1945
1946         residue = NCR5380_dma_residual(instance);
1947         c -= residue;
1948         *count -= c;
1949         *data += c;
1950         *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1951
1952 #ifdef READ_OVERRUNS
1953         if (*phase == p && (p & SR_IO) && residue == 0) {
1954                 if (overrun) {
1955                         dprintk(NDEBUG_DMA, ("Got an input overrun, using saved byte\n"));
1956                         **data = saved_data;
1957                         *data += 1;
1958                         *count -= 1;
1959                         cnt = toPIO = 1;
1960                 } else {
1961                         printk("No overrun??\n");
1962                         cnt = toPIO = 2;
1963                 }
1964                 dprintk(NDEBUG_DMA, ("Doing %d-byte PIO to 0x%X\n", cnt, *data));
1965                 NCR5380_transfer_pio(instance, phase, &cnt, data);
1966                 *count -= toPIO - cnt;
1967         }
1968 #endif
1969
1970         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)));
1971         return 0;
1972
1973 #elif defined(REAL_DMA)
1974         return 0;
1975 #else                           /* defined(REAL_DMA_POLL) */
1976         if (p & SR_IO) {
1977 #ifdef DMA_WORKS_RIGHT
1978                 foo = NCR5380_pread(instance, d, c);
1979 #else
1980                 int diff = 1;
1981                 if (hostdata->flags & FLAG_NCR53C400) {
1982                         diff = 0;
1983                 }
1984                 if (!(foo = NCR5380_pread(instance, d, c - diff))) {
1985                         /*
1986                          * We can't disable DMA mode after successfully transferring 
1987                          * what we plan to be the last byte, since that would open up
1988                          * a race condition where if the target asserted REQ before 
1989                          * we got the DMA mode reset, the NCR5380 would have latched
1990                          * an additional byte into the INPUT DATA register and we'd
1991                          * have dropped it.
1992                          * 
1993                          * The workaround was to transfer one fewer bytes than we 
1994                          * intended to with the pseudo-DMA read function, wait for 
1995                          * the chip to latch the last byte, read it, and then disable
1996                          * pseudo-DMA mode.
1997                          * 
1998                          * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1999                          * REQ is deasserted when ACK is asserted, and not reasserted
2000                          * until ACK goes false.  Since the NCR5380 won't lower ACK
2001                          * until DACK is asserted, which won't happen unless we twiddle
2002                          * the DMA port or we take the NCR5380 out of DMA mode, we 
2003                          * can guarantee that we won't handshake another extra 
2004                          * byte.
2005                          */
2006
2007                         if (!(hostdata->flags & FLAG_NCR53C400)) {
2008                                 while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ));
2009                                 /* Wait for clean handshake */
2010                                 while (NCR5380_read(STATUS_REG) & SR_REQ);
2011                                 d[c - 1] = NCR5380_read(INPUT_DATA_REG);
2012                         }
2013                 }
2014 #endif
2015         } else {
2016 #ifdef DMA_WORKS_RIGHT
2017                 foo = NCR5380_pwrite(instance, d, c);
2018 #else
2019                 int timeout;
2020                 dprintk(NDEBUG_C400_PWRITE, ("About to pwrite %d bytes\n", c));
2021                 if (!(foo = NCR5380_pwrite(instance, d, c))) {
2022                         /*
2023                          * Wait for the last byte to be sent.  If REQ is being asserted for 
2024                          * the byte we're interested, we'll ACK it and it will go false.  
2025                          */
2026                         if (!(hostdata->flags & FLAG_HAS_LAST_BYTE_SENT)) {
2027                                 timeout = 20000;
2028                                 while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_DRQ) && (NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH));
2029
2030                                 if (!timeout)
2031                                         dprintk(NDEBUG_LAST_BYTE_SENT, ("scsi%d : timed out on last byte\n", instance->host_no));
2032
2033                                 if (hostdata->flags & FLAG_CHECK_LAST_BYTE_SENT) {
2034                                         hostdata->flags &= ~FLAG_CHECK_LAST_BYTE_SENT;
2035                                         if (NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT) {
2036                                                 hostdata->flags |= FLAG_HAS_LAST_BYTE_SENT;
2037                                                 dprintk(NDEBUG_LAST_WRITE_SENT, ("scsi%d : last bit sent works\n", instance->host_no));
2038                                         }
2039                                 }
2040                         } else {
2041                                 dprintk(NDEBUG_C400_PWRITE, ("Waiting for LASTBYTE\n"));
2042                                 while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT));
2043                                 dprintk(NDEBUG_C400_PWRITE, ("Got LASTBYTE\n"));
2044                         }
2045                 }
2046 #endif
2047         }
2048         NCR5380_write(MODE_REG, MR_BASE);
2049         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2050
2051         if ((!(p & SR_IO)) && (hostdata->flags & FLAG_NCR53C400)) {
2052                 dprintk(NDEBUG_C400_PWRITE, ("53C400w: Checking for IRQ\n"));
2053                 if (NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) {
2054                         dprintk(NDEBUG_C400_PWRITE, ("53C400w:    got it, reading reset interrupt reg\n"));
2055                         NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2056                 } else {
2057                         printk("53C400w:    IRQ NOT THERE!\n");
2058                 }
2059         }
2060         *data = d + c;
2061         *count = 0;
2062         *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
2063 #if defined(PSEUDO_DMA) && defined(UNSAFE)
2064         spin_lock_irq(instance->host_lock);
2065 #endif                          /* defined(REAL_DMA_POLL) */
2066         return foo;
2067 #endif                          /* def REAL_DMA */
2068 }
2069 #endif                          /* defined(REAL_DMA) | defined(PSEUDO_DMA) */
2070
2071 /*
2072  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2073  *
2074  * Purpose : run through the various SCSI phases and do as the target 
2075  *      directs us to.  Operates on the currently connected command, 
2076  *      instance->connected.
2077  *
2078  * Inputs : instance, instance for which we are doing commands
2079  *
2080  * Side effects : SCSI things happen, the disconnected queue will be 
2081  *      modified if a command disconnects, *instance->connected will
2082  *      change.
2083  *
2084  * XXX Note : we need to watch for bus free or a reset condition here 
2085  *      to recover from an unexpected bus free condition.
2086  *
2087  * Locks: io_request_lock held by caller in IRQ mode
2088  */
2089
2090 static void NCR5380_information_transfer(struct Scsi_Host *instance) {
2091         NCR5380_local_declare();
2092         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)instance->hostdata;
2093         unsigned char msgout = NOP;
2094         int sink = 0;
2095         int len;
2096 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2097         int transfersize;
2098 #endif
2099         unsigned char *data;
2100         unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2101         Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2102         /* RvC: we need to set the end of the polling time */
2103         unsigned long poll_time = jiffies + USLEEP_POLL;
2104
2105         NCR5380_setup(instance);
2106
2107         while (1) {
2108                 tmp = NCR5380_read(STATUS_REG);
2109                 /* We only have a valid SCSI phase when REQ is asserted */
2110                 if (tmp & SR_REQ) {
2111                         phase = (tmp & PHASE_MASK);
2112                         if (phase != old_phase) {
2113                                 old_phase = phase;
2114                                 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2115                         }
2116                         if (sink && (phase != PHASE_MSGOUT)) {
2117                                 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2118
2119                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
2120                                 while (NCR5380_read(STATUS_REG) & SR_REQ);
2121                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2122                                 sink = 0;
2123                                 continue;
2124                         }
2125                         switch (phase) {
2126                         case PHASE_DATAIN:
2127                         case PHASE_DATAOUT:
2128 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2129                                 printk("scsi%d : NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n", instance->host_no);
2130                                 sink = 1;
2131                                 do_abort(instance);
2132                                 cmd->result = DID_ERROR << 16;
2133                                 cmd->done(cmd);
2134                                 return;
2135 #endif
2136                                 /* 
2137                                  * If there is no room left in the current buffer in the
2138                                  * scatter-gather list, move onto the next one.
2139                                  */
2140
2141                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2142                                         ++cmd->SCp.buffer;
2143                                         --cmd->SCp.buffers_residual;
2144                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
2145                                         cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
2146                                                        cmd->SCp.buffer->offset;
2147                                         dprintk(NDEBUG_INFORMATION, ("scsi%d : %d bytes and %d buffers left\n", instance->host_no, cmd->SCp.this_residual, cmd->SCp.buffers_residual));
2148                                 }
2149                                 /*
2150                                  * The preferred transfer method is going to be 
2151                                  * PSEUDO-DMA for systems that are strictly PIO,
2152                                  * since we can let the hardware do the handshaking.
2153                                  *
2154                                  * For this to work, we need to know the transfersize
2155                                  * ahead of time, since the pseudo-DMA code will sit
2156                                  * in an unconditional loop.
2157                                  */
2158
2159 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
2160                                 /* KLL
2161                                  * PSEUDO_DMA is defined here. If this is the g_NCR5380
2162                                  * driver then it will always be defined, so the
2163                                  * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base
2164                                  * NCR5380 case.  I think this is a fairly clean solution.
2165                                  * We supplement these 2 if's with the flag.
2166                                  */
2167 #ifdef NCR5380_dma_xfer_len
2168                                 if (!cmd->device->borken && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) {
2169 #else
2170                                 transfersize = cmd->transfersize;
2171
2172 #ifdef LIMIT_TRANSFERSIZE       /* If we have problems with interrupt service */
2173                                 if (transfersize > 512)
2174                                         transfersize = 512;
2175 #endif                          /* LIMIT_TRANSFERSIZE */
2176
2177                                 if (!cmd->device->borken && transfersize && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && cmd->SCp.this_residual && !(cmd->SCp.this_residual % transfersize)) {
2178                                         /* Limit transfers to 32K, for xx400 & xx406
2179                                          * pseudoDMA that transfers in 128 bytes blocks. */
2180                                         if (transfersize > 32 * 1024)
2181                                                 transfersize = 32 * 1024;
2182 #endif
2183                                         len = transfersize;
2184                                         if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
2185                                                 /*
2186                                                  * If the watchdog timer fires, all future accesses to this
2187                                                  * device will use the polled-IO.
2188                                                  */
2189                                                 scmd_printk(KERN_INFO, cmd,
2190                                                             "switching to slow handshake\n");
2191                                                 cmd->device->borken = 1;
2192                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2193                                                 sink = 1;
2194                                                 do_abort(instance);
2195                                                 cmd->result = DID_ERROR << 16;
2196                                                 cmd->done(cmd);
2197                                                 /* XXX - need to source or sink data here, as appropriate */
2198                                         } else
2199                                                 cmd->SCp.this_residual -= transfersize - len;
2200                                 } else
2201 #endif                          /* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
2202                                         NCR5380_transfer_pio(instance, &phase, (int *) &cmd->SCp.this_residual, (unsigned char **)
2203                                                              &cmd->SCp.ptr);
2204                                 break;
2205                         case PHASE_MSGIN:
2206                                 len = 1;
2207                                 data = &tmp;
2208                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2209                                 cmd->SCp.Message = tmp;
2210
2211                                 switch (tmp) {
2212                                         /*
2213                                          * Linking lets us reduce the time required to get the 
2214                                          * next command out to the device, hopefully this will
2215                                          * mean we don't waste another revolution due to the delays
2216                                          * required by ARBITRATION and another SELECTION.
2217                                          *
2218                                          * In the current implementation proposal, low level drivers
2219                                          * merely have to start the next command, pointed to by 
2220                                          * next_link, done() is called as with unlinked commands.
2221                                          */
2222 #ifdef LINKED
2223                                 case LINKED_CMD_COMPLETE:
2224                                 case LINKED_FLG_CMD_COMPLETE:
2225                                         /* Accept message by clearing ACK */
2226                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2227                                         dprintk(NDEBUG_LINKED, ("scsi%d : target %d lun %d linked command complete.\n", instance->host_no, cmd->device->id, cmd->device->lun));
2228                                         /* 
2229                                          * Sanity check : A linked command should only terminate with
2230                                          * one of these messages if there are more linked commands
2231                                          * available.
2232                                          */
2233                                         if (!cmd->next_link) {
2234                                                 printk("scsi%d : target %d lun %d linked command complete, no next_link\n" instance->host_no, cmd->device->id, cmd->device->lun);
2235                                                 sink = 1;
2236                                                 do_abort(instance);
2237                                                 return;
2238                                         }
2239                                         initialize_SCp(cmd->next_link);
2240                                         /* The next command is still part of this process */
2241                                         cmd->next_link->tag = cmd->tag;
2242                                         cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2243                                         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));
2244                                         collect_stats(hostdata, cmd);
2245                                         cmd->scsi_done(cmd);
2246                                         cmd = hostdata->connected;
2247                                         break;
2248 #endif                          /* def LINKED */
2249                                 case ABORT:
2250                                 case COMMAND_COMPLETE:
2251                                         /* Accept message by clearing ACK */
2252                                         sink = 1;
2253                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2254                                         hostdata->connected = NULL;
2255                                         dprintk(NDEBUG_QUEUES, ("scsi%d : command for target %d, lun %d completed\n", instance->host_no, cmd->device->id, cmd->device->lun));
2256                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2257
2258                                         /* 
2259                                          * I'm not sure what the correct thing to do here is : 
2260                                          * 
2261                                          * If the command that just executed is NOT a request 
2262                                          * sense, the obvious thing to do is to set the result
2263                                          * code to the values of the stored parameters.
2264                                          * 
2265                                          * If it was a REQUEST SENSE command, we need some way 
2266                                          * to differentiate between the failure code of the original
2267                                          * and the failure code of the REQUEST sense - the obvious
2268                                          * case is success, where we fall through and leave the result
2269                                          * code unchanged.
2270                                          * 
2271                                          * The non-obvious place is where the REQUEST SENSE failed 
2272                                          */
2273
2274                                         if (cmd->cmnd[0] != REQUEST_SENSE)
2275                                                 cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2276                                         else if (status_byte(cmd->SCp.Status) != GOOD)
2277                                                 cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2278
2279 #ifdef AUTOSENSE
2280                                         if ((cmd->cmnd[0] != REQUEST_SENSE) && (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2281                                                 dprintk(NDEBUG_AUTOSENSE, ("scsi%d : performing request sense\n", instance->host_no));
2282                                                 cmd->cmnd[0] = REQUEST_SENSE;
2283                                                 cmd->cmnd[1] &= 0xe0;
2284                                                 cmd->cmnd[2] = 0;
2285                                                 cmd->cmnd[3] = 0;
2286                                                 cmd->cmnd[4] = sizeof(cmd->sense_buffer);
2287                                                 cmd->cmnd[5] = 0;
2288
2289                                                 cmd->SCp.buffer = NULL;
2290                                                 cmd->SCp.buffers_residual = 0;
2291                                                 cmd->SCp.ptr = (char *) cmd->sense_buffer;
2292                                                 cmd->SCp.this_residual = sizeof(cmd->sense_buffer);
2293
2294                                                 LIST(cmd, hostdata->issue_queue);
2295                                                 cmd->host_scribble = (unsigned char *)
2296                                                     hostdata->issue_queue;
2297                                                 hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2298                                                 dprintk(NDEBUG_QUEUES, ("scsi%d : REQUEST SENSE added to head of issue queue\n", instance->host_no));
2299                                         } else
2300 #endif                          /* def AUTOSENSE */
2301                                         {
2302                                                 collect_stats(hostdata, cmd);
2303                                                 cmd->scsi_done(cmd);
2304                                         }
2305
2306                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2307                                         /* 
2308                                          * Restore phase bits to 0 so an interrupted selection, 
2309                                          * arbitration can resume.
2310                                          */
2311                                         NCR5380_write(TARGET_COMMAND_REG, 0);
2312
2313                                         while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2314                                                 barrier();
2315                                         return;
2316                                 case MESSAGE_REJECT:
2317                                         /* Accept message by clearing ACK */
2318                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2319                                         switch (hostdata->last_message) {
2320                                         case HEAD_OF_QUEUE_TAG:
2321                                         case ORDERED_QUEUE_TAG:
2322                                         case SIMPLE_QUEUE_TAG:
2323                                                 cmd->device->simple_tags = 0;
2324                                                 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2325                                                 break;
2326                                         default:
2327                                                 break;
2328                                         }
2329                                 case DISCONNECT:{
2330                                                 /* Accept message by clearing ACK */
2331                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2332                                                 cmd->device->disconnect = 1;
2333                                                 LIST(cmd, hostdata->disconnected_queue);
2334                                                 cmd->host_scribble = (unsigned char *)
2335                                                     hostdata->disconnected_queue;
2336                                                 hostdata->connected = NULL;
2337                                                 hostdata->disconnected_queue = cmd;
2338                                                 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));
2339                                                 /* 
2340                                                  * Restore phase bits to 0 so an interrupted selection, 
2341                                                  * arbitration can resume.
2342                                                  */
2343                                                 NCR5380_write(TARGET_COMMAND_REG, 0);
2344
2345                                                 /* Enable reselect interrupts */
2346                                                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2347                                                 /* Wait for bus free to avoid nasty timeouts - FIXME timeout !*/
2348                                                 /* NCR538_poll_politely(instance, STATUS_REG, SR_BSY, 0, 30 * HZ); */
2349                                                 while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2350                                                         barrier();
2351                                                 return;
2352                                         }
2353                                         /* 
2354                                          * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2355                                          * operation, in violation of the SCSI spec so we can safely 
2356                                          * ignore SAVE/RESTORE pointers calls.
2357                                          *
2358                                          * Unfortunately, some disks violate the SCSI spec and 
2359                                          * don't issue the required SAVE_POINTERS message before
2360                                          * disconnecting, and we have to break spec to remain 
2361                                          * compatible.
2362                                          */
2363                                 case SAVE_POINTERS:
2364                                 case RESTORE_POINTERS:
2365                                         /* Accept message by clearing ACK */
2366                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2367                                         break;
2368                                 case EXTENDED_MESSAGE:
2369 /* 
2370  * Extended messages are sent in the following format :
2371  * Byte         
2372  * 0            EXTENDED_MESSAGE == 1
2373  * 1            length (includes one byte for code, doesn't 
2374  *              include first two bytes)
2375  * 2            code
2376  * 3..length+1  arguments
2377  *
2378  * Start the extended message buffer with the EXTENDED_MESSAGE
2379  * byte, since spi_print_msg() wants the whole thing.  
2380  */
2381                                         extended_msg[0] = EXTENDED_MESSAGE;
2382                                         /* Accept first byte by clearing ACK */
2383                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2384                                         dprintk(NDEBUG_EXTENDED, ("scsi%d : receiving extended message\n", instance->host_no));
2385
2386                                         len = 2;
2387                                         data = extended_msg + 1;
2388                                         phase = PHASE_MSGIN;
2389                                         NCR5380_transfer_pio(instance, &phase, &len, &data);
2390
2391                                         dprintk(NDEBUG_EXTENDED, ("scsi%d : length=%d, code=0x%02x\n", instance->host_no, (int) extended_msg[1], (int) extended_msg[2]));
2392
2393                                         if (!len && extended_msg[1] <= (sizeof(extended_msg) - 1)) {
2394                                                 /* Accept third byte by clearing ACK */
2395                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2396                                                 len = extended_msg[1] - 1;
2397                                                 data = extended_msg + 3;
2398                                                 phase = PHASE_MSGIN;
2399
2400                                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2401                                                 dprintk(NDEBUG_EXTENDED, ("scsi%d : message received, residual %d\n", instance->host_no, len));
2402
2403                                                 switch (extended_msg[2]) {
2404                                                 case EXTENDED_SDTR:
2405                                                 case EXTENDED_WDTR:
2406                                                 case EXTENDED_MODIFY_DATA_POINTER:
2407                                                 case EXTENDED_EXTENDED_IDENTIFY:
2408                                                         tmp = 0;
2409                                                 }
2410                                         } else if (len) {
2411                                                 printk("scsi%d: error receiving extended message\n", instance->host_no);
2412                                                 tmp = 0;
2413                                         } else {
2414                                                 printk("scsi%d: extended message code %02x length %d is too long\n", instance->host_no, extended_msg[2], extended_msg[1]);
2415                                                 tmp = 0;
2416                                         }
2417                                         /* Fall through to reject message */
2418
2419                                         /* 
2420                                          * If we get something weird that we aren't expecting, 
2421                                          * reject it.
2422                                          */
2423                                 default:
2424                                         if (!tmp) {
2425                                                 printk("scsi%d: rejecting message ", instance->host_no);
2426                                                 spi_print_msg(extended_msg);
2427                                                 printk("\n");
2428                                         } else if (tmp != EXTENDED_MESSAGE)
2429                                                 scmd_printk(KERN_INFO, cmd,
2430                                                         "rejecting unknown message %02x\n",tmp);
2431                                         else
2432                                                 scmd_printk(KERN_INFO, cmd,
2433                                                         "rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);
2434
2435                                         msgout = MESSAGE_REJECT;
2436                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2437                                         break;
2438                                 }       /* switch (tmp) */
2439                                 break;
2440                         case PHASE_MSGOUT:
2441                                 len = 1;
2442                                 data = &msgout;
2443                                 hostdata->last_message = msgout;
2444                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2445                                 if (msgout == ABORT) {
2446                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2447                                         hostdata->connected = NULL;
2448                                         cmd->result = DID_ERROR << 16;
2449                                         collect_stats(hostdata, cmd);
2450                                         cmd->scsi_done(cmd);
2451                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2452                                         return;
2453                                 }
2454                                 msgout = NOP;
2455                                 break;
2456                         case PHASE_CMDOUT:
2457                                 len = cmd->cmd_len;
2458                                 data = cmd->cmnd;
2459                                 /* 
2460                                  * XXX for performance reasons, on machines with a 
2461                                  * PSEUDO-DMA architecture we should probably 
2462                                  * use the dma transfer function.  
2463                                  */
2464                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2465                                 if (!cmd->device->disconnect && should_disconnect(cmd->cmnd[0])) {
2466                                         NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2467                                         dprintk(NDEBUG_USLEEP, ("scsi%d : issued command, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2468                                         return;
2469                                 }
2470                                 break;
2471                         case PHASE_STATIN:
2472                                 len = 1;
2473                                 data = &tmp;
2474                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2475                                 cmd->SCp.Status = tmp;
2476                                 break;
2477                         default:
2478                                 printk("scsi%d : unknown phase\n", instance->host_no);
2479                                 NCR5380_dprint(NDEBUG_ALL, instance);
2480                         }       /* switch(phase) */
2481                 }               /* if (tmp * SR_REQ) */
2482                 else {
2483                         /* RvC: go to sleep if polling time expired
2484                          */
2485                         if (!cmd->device->disconnect && time_after_eq(jiffies, poll_time)) {
2486                                 NCR5380_set_timer(hostdata, USLEEP_SLEEP);
2487                                 dprintk(NDEBUG_USLEEP, ("scsi%d : poll timed out, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
2488                                 return;
2489                         }
2490                 }
2491         }                       /* while (1) */
2492 }
2493
2494 /*
2495  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2496  *
2497  * Purpose : does reselection, initializing the instance->connected 
2498  *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q 
2499  *      nexus has been reestablished,
2500  *      
2501  * Inputs : instance - this instance of the NCR5380.
2502  *
2503  * Locks: io_request_lock held by caller if IRQ driven
2504  */
2505
2506 static void NCR5380_reselect(struct Scsi_Host *instance) {
2507         NCR5380_local_declare();
2508         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)
2509          instance->hostdata;
2510         unsigned char target_mask;
2511         unsigned char lun, phase;
2512         int len;
2513         unsigned char msg[3];
2514         unsigned char *data;
2515         Scsi_Cmnd *tmp = NULL, *prev;
2516         int abort = 0;
2517         NCR5380_setup(instance);
2518
2519         /*
2520          * Disable arbitration, etc. since the host adapter obviously
2521          * lost, and tell an interrupted NCR5380_select() to restart.
2522          */
2523
2524         NCR5380_write(MODE_REG, MR_BASE);
2525         hostdata->restart_select = 1;
2526
2527         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2528         dprintk(NDEBUG_SELECTION, ("scsi%d : reselect\n", instance->host_no));
2529
2530         /* 
2531          * At this point, we have detected that our SCSI ID is on the bus,
2532          * SEL is true and BSY was false for at least one bus settle delay
2533          * (400 ns).
2534          *
2535          * We must assert BSY ourselves, until the target drops the SEL
2536          * signal.
2537          */
2538
2539         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2540
2541         /* FIXME: timeout too long, must fail to workqueue */   
2542         if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
2543                 abort = 1;
2544                 
2545         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2546
2547         /*
2548          * Wait for target to go into MSGIN.
2549          * FIXME: timeout needed and fail to work queeu
2550          */
2551
2552         if(NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 2*HZ))
2553                 abort = 1;
2554
2555         len = 1;
2556         data = msg;
2557         phase = PHASE_MSGIN;
2558         NCR5380_transfer_pio(instance, &phase, &len, &data);
2559
2560         if (!(msg[0] & 0x80)) {
2561                 printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
2562                 spi_print_msg(msg);
2563                 abort = 1;
2564         } else {
2565                 /* Accept message by clearing ACK */
2566                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2567                 lun = (msg[0] & 0x07);
2568
2569                 /* 
2570                  * We need to add code for SCSI-II to track which devices have
2571                  * I_T_L_Q nexuses established, and which have simple I_T_L
2572                  * nexuses so we can chose to do additional data transfer.
2573                  */
2574
2575                 /* 
2576                  * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we 
2577                  * just reestablished, and remove it from the disconnected queue.
2578                  */
2579
2580
2581                 for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (Scsi_Cmnd *) tmp->host_scribble)
2582                         if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2583                             ) {
2584                                 if (prev) {
2585                                         REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
2586                                         prev->host_scribble = tmp->host_scribble;
2587                                 } else {
2588                                         REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
2589                                         hostdata->disconnected_queue = (Scsi_Cmnd *) tmp->host_scribble;
2590                                 }
2591                                 tmp->host_scribble = NULL;
2592                                 break;
2593                         }
2594                 if (!tmp) {
2595                         printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
2596                         /* 
2597                          * Since we have an established nexus that we can't do anything with,
2598                          * we must abort it.  
2599                          */
2600                         abort = 1;
2601                 }
2602         }
2603
2604         if (abort) {
2605                 do_abort(instance);
2606         } else {
2607                 hostdata->connected = tmp;
2608                 dprintk(NDEBUG_RESELECTION, ("scsi%d : nexus established, target = %d, lun = %d, tag = %d\n", instance->host_no, tmp->target, tmp->lun, tmp->tag));
2609         }
2610 }
2611
2612 /*
2613  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2614  *
2615  * Purpose : called by interrupt handler when DMA finishes or a phase
2616  *      mismatch occurs (which would finish the DMA transfer).  
2617  *
2618  * Inputs : instance - this instance of the NCR5380.
2619  *
2620  * Returns : pointer to the Scsi_Cmnd structure for which the I_T_L
2621  *      nexus has been reestablished, on failure NULL is returned.
2622  */
2623
2624 #ifdef REAL_DMA
2625 static void NCR5380_dma_complete(NCR5380_instance * instance) {
2626         NCR5380_local_declare();
2627         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata * instance->hostdata);
2628         int transferred;
2629         NCR5380_setup(instance);
2630
2631         /*
2632          * XXX this might not be right.
2633          *
2634          * Wait for final byte to transfer, ie wait for ACK to go false.
2635          *
2636          * We should use the Last Byte Sent bit, unfortunately this is 
2637          * not available on the 5380/5381 (only the various CMOS chips)
2638          *
2639          * FIXME: timeout, and need to handle long timeout/irq case
2640          */
2641
2642         NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2643
2644         NCR5380_write(MODE_REG, MR_BASE);
2645         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2646
2647         /*
2648          * The only places we should see a phase mismatch and have to send
2649          * data from the same set of pointers will be the data transfer
2650          * phases.  So, residual, requested length are only important here.
2651          */
2652
2653         if (!(hostdata->connected->SCp.phase & SR_CD)) {
2654                 transferred = instance->dmalen - NCR5380_dma_residual();
2655                 hostdata->connected->SCp.this_residual -= transferred;
2656                 hostdata->connected->SCp.ptr += transferred;
2657         }
2658 }
2659 #endif                          /* def REAL_DMA */
2660
2661 /*
2662  * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2663  *
2664  * Purpose : abort a command
2665  *
2666  * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the 
2667  *      host byte of the result field to, if zero DID_ABORTED is 
2668  *      used.
2669  *
2670  * Returns : 0 - success, -1 on failure.
2671  *
2672  *      XXX - there is no way to abort the command that is currently 
2673  *      connected, you have to wait for it to complete.  If this is 
2674  *      a problem, we could implement longjmp() / setjmp(), setjmp()
2675  *      called where the loop started in NCR5380_main().
2676  *
2677  * Locks: host lock taken by caller
2678  */
2679
2680 static int NCR5380_abort(Scsi_Cmnd * cmd) {
2681         NCR5380_local_declare();
2682         struct Scsi_Host *instance = cmd->device->host;
2683         struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
2684         Scsi_Cmnd *tmp, **prev;
2685         
2686         printk(KERN_WARNING "scsi%d : aborting command\n", instance->host_no);
2687         scsi_print_command(cmd);
2688
2689         NCR5380_print_status(instance);
2690
2691         NCR5380_setup(instance);
2692
2693         dprintk(NDEBUG_ABORT, ("scsi%d : abort called\n", instance->host_no));
2694         dprintk(NDEBUG_ABORT, ("        basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG)));
2695
2696 #if 0
2697 /*
2698  * Case 1 : If the command is the currently executing command, 
2699  * we'll set the aborted flag and return control so that 
2700  * information transfer routine can exit cleanly.
2701  */
2702
2703         if (hostdata->connected == cmd) {
2704                 dprintk(NDEBUG_ABORT, ("scsi%d : aborting connected command\n", instance->host_no));
2705                 hostdata->aborted = 1;
2706 /*
2707  * We should perform BSY checking, and make sure we haven't slipped
2708  * into BUS FREE.
2709  */
2710
2711                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN);
2712 /* 
2713  * Since we can't change phases until we've completed the current 
2714  * handshake, we have to source or sink a byte of data if the current
2715  * phase is not MSGOUT.
2716  */
2717
2718 /* 
2719  * Return control to the executing NCR drive so we can clear the
2720  * aborted flag and get back into our main loop.
2721  */
2722
2723                 return 0;
2724         }
2725 #endif
2726
2727 /* 
2728  * Case 2 : If the command hasn't been issued yet, we simply remove it 
2729  *          from the issue queue.
2730  */
2731  
2732         dprintk(NDEBUG_ABORT, ("scsi%d : abort going into loop.\n", instance->host_no));
2733         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)
2734                 if (cmd == tmp) {
2735                         REMOVE(5, *prev, tmp, tmp->host_scribble);
2736                         (*prev) = (Scsi_Cmnd *) tmp->host_scribble;
2737                         tmp->host_scribble = NULL;
2738                         tmp->result = DID_ABORT << 16;
2739                         dprintk(NDEBUG_ABORT, ("scsi%d : abort removed command from issue queue.\n", instance->host_no));
2740                         tmp->done(tmp);
2741                         return SUCCESS;
2742                 }
2743 #if (NDEBUG  & NDEBUG_ABORT)
2744         /* KLL */
2745                 else if (prev == tmp)
2746                         printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
2747 #endif
2748
2749 /* 
2750  * Case 3 : If any commands are connected, we're going to fail the abort
2751  *          and let the high level SCSI driver retry at a later time or 
2752  *          issue a reset.
2753  *
2754  *          Timeouts, and therefore aborted commands, will be highly unlikely
2755  *          and handling them cleanly in this situation would make the common
2756  *          case of noresets less efficient, and would pollute our code.  So,
2757  *          we fail.
2758  */
2759
2760         if (hostdata->connected) {
2761                 dprintk(NDEBUG_ABORT, ("scsi%d : abort failed, command connected.\n", instance->host_no));
2762                 return FAILED;
2763         }
2764 /*
2765  * Case 4: If the command is currently disconnected from the bus, and 
2766  *      there are no connected commands, we reconnect the I_T_L or 
2767  *      I_T_L_Q nexus associated with it, go into message out, and send 
2768  *      an abort message.
2769  *
2770  * This case is especially ugly. In order to reestablish the nexus, we
2771  * need to call NCR5380_select().  The easiest way to implement this 
2772  * function was to abort if the bus was busy, and let the interrupt
2773  * handler triggered on the SEL for reselect take care of lost arbitrations
2774  * where necessary, meaning interrupts need to be enabled.
2775  *
2776  * When interrupts are enabled, the queues may change - so we 
2777  * can't remove it from the disconnected queue before selecting it
2778  * because that could cause a failure in hashing the nexus if that 
2779  * device reselected.
2780  * 
2781  * Since the queues may change, we can't use the pointers from when we
2782  * first locate it.
2783  *
2784  * So, we must first locate the command, and if NCR5380_select()
2785  * succeeds, then issue the abort, relocate the command and remove
2786  * it from the disconnected queue.
2787  */
2788
2789         for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp; tmp = (Scsi_Cmnd *) tmp->host_scribble)
2790                 if (cmd == tmp) {
2791                         dprintk(NDEBUG_ABORT, ("scsi%d : aborting disconnected command.\n", instance->host_no));
2792
2793                         if (NCR5380_select(instance, cmd, (int) cmd->tag))
2794                                 return FAILED;
2795                         dprintk(NDEBUG_ABORT, ("scsi%d : nexus reestablished.\n", instance->host_no));
2796
2797                         do_abort(instance);
2798
2799                         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)
2800                                 if (cmd == tmp) {
2801                                         REMOVE(5, *prev, tmp, tmp->host_scribble);
2802                                         *prev = (Scsi_Cmnd *) tmp->host_scribble;
2803                                         tmp->host_scribble = NULL;
2804                                         tmp->result = DID_ABORT << 16;
2805                                         tmp->done(tmp);
2806                                         return SUCCESS;
2807                                 }
2808                 }
2809 /*
2810  * Case 5 : If we reached this point, the command was not found in any of 
2811  *          the queues.
2812  *
2813  * We probably reached this point because of an unlikely race condition
2814  * between the command completing successfully and the abortion code,
2815  * so we won't panic, but we will notify the user in case something really
2816  * broke.
2817  */
2818         printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
2819                         "         before abortion\n", instance->host_no);
2820         return FAILED;
2821 }
2822
2823
2824 /* 
2825  * Function : int NCR5380_bus_reset (Scsi_Cmnd *cmd)
2826  * 
2827  * Purpose : reset the SCSI bus.
2828  *
2829  * Returns : SUCCESS
2830  *
2831  * Locks: host lock taken by caller
2832  */
2833
2834 static int NCR5380_bus_reset(Scsi_Cmnd * cmd)
2835 {
2836         struct Scsi_Host *instance = cmd->device->host;
2837
2838         NCR5380_local_declare();
2839         NCR5380_setup(instance);
2840         NCR5380_print_status(instance);
2841
2842         spin_lock_irq(instance->host_lock);
2843         do_reset(instance);
2844         spin_unlock_irq(instance->host_lock);
2845
2846         return SUCCESS;
2847 }