File: /usr/src/linux/drivers/scsi/sun3_NCR5380.c

1     /* sun3_NCR5380.c -- adapted from atari_NCR5380.c for the sun3 by 
2        Sam Creasey. */ 
3     /* 
4      * NCR 5380 generic driver routines.  These should make it *trivial*
5      * 	to implement 5380 SCSI drivers under Linux with a non-trantor
6      *	architecture.
7      *
8      *	Note that these routines also work with NR53c400 family chips.
9      *
10      * Copyright 1993, Drew Eckhardt
11      *	Visionary Computing 
12      *	(Unix and Linux consulting and custom programming)
13      * 	drew@colorado.edu
14      *	+1 (303) 666-5836
15      *
16      * DISTRIBUTION RELEASE 6. 
17      *
18      * For more information, please consult 
19      *
20      * NCR 5380 Family
21      * SCSI Protocol Controller
22      * Databook
23      *
24      * NCR Microelectronics
25      * 1635 Aeroplaza Drive
26      * Colorado Springs, CO 80916
27      * 1+ (719) 578-3400
28      * 1+ (800) 334-5454
29      */
30     
31     /*
32      * ++roman: To port the 5380 driver to the Atari, I had to do some changes in
33      * this file, too:
34      *
35      *  - Some of the debug statements were incorrect (undefined variables and the
36      *    like). I fixed that.
37      *
38      *  - In information_transfer(), I think a #ifdef was wrong. Looking at the
39      *    possible DMA transfer size should also happen for REAL_DMA. I added this
40      *    in the #if statement.
41      *
42      *  - When using real DMA, information_transfer() should return in a DATAOUT
43      *    phase after starting the DMA. It has nothing more to do.
44      *
45      *  - The interrupt service routine should run main after end of DMA, too (not
46      *    only after RESELECTION interrupts). Additionally, it should _not_ test
47      *    for more interrupts after running main, since a DMA process may have
48      *    been started and interrupts are turned on now. The new int could happen
49      *    inside the execution of NCR5380_intr(), leading to recursive
50      *    calls.
51      *
52      *  - I've added a function merge_contiguous_buffers() that tries to
53      *    merge scatter-gather buffers that are located at contiguous
54      *    physical addresses and can be processed with the same DMA setup.
55      *    Since most scatter-gather operations work on a page (4K) of
56      *    4 buffers (1K), in more than 90% of all cases three interrupts and
57      *    DMA setup actions are saved.
58      *
59      * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
60      *    and USLEEP, because these were messing up readability and will never be
61      *    needed for Atari SCSI.
62      * 
63      * - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
64      *   stuff), and 'main' is executed in a bottom half if awoken by an
65      *   interrupt.
66      *
67      * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
68      *   constructs. In my eyes, this made the source rather unreadable, so I
69      *   finally replaced that by the *_PRINTK() macros.
70      *
71      */
72     
73     /*
74      * Further development / testing that should be done : 
75      * 1.  Test linked command handling code after Eric is ready with 
76      *     the high level code.
77      */
78     
79     #if (NDEBUG & NDEBUG_LISTS)
80     #define LIST(x,y) \
81       { printk("LINE:%d   Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); \
82         if ((x)==(y)) udelay(5); }
83     #define REMOVE(w,x,y,z) \
84       { printk("LINE:%d   Removing: %p->%p  %p->%p \n", __LINE__, \
85     	   (void*)(w), (void*)(x), (void*)(y), (void*)(z)); \
86         if ((x)==(y)) udelay(5); }
87     #else
88     #define LIST(x,y)
89     #define REMOVE(w,x,y,z)
90     #endif
91     
92     #ifndef notyet
93     #undef LINKED
94     #endif
95     
96     /*
97      * Design
98      * Issues :
99      *
100      * The other Linux SCSI drivers were written when Linux was Intel PC-only,
101      * and specifically for each board rather than each chip.  This makes their
102      * adaptation to platforms like the Mac (Some of which use NCR5380's)
103      * more difficult than it has to be.
104      *
105      * Also, many of the SCSI drivers were written before the command queuing
106      * routines were implemented, meaning their implementations of queued 
107      * commands were hacked on rather than designed in from the start.
108      *
109      * When I designed the Linux SCSI drivers I figured that 
110      * while having two different SCSI boards in a system might be useful
111      * for debugging things, two of the same type wouldn't be used.
112      * Well, I was wrong and a number of users have mailed me about running
113      * multiple high-performance SCSI boards in a server.
114      *
115      * Finally, when I get questions from users, I have no idea what 
116      * revision of my driver they are running.
117      *
118      * This driver attempts to address these problems :
119      * This is a generic 5380 driver.  To use it on a different platform, 
120      * one simply writes appropriate system specific macros (ie, data
121      * transfer - some PC's will use the I/O bus, 68K's must use 
122      * memory mapped) and drops this file in their 'C' wrapper.
123      *
124      * As far as command queueing, two queues are maintained for 
125      * each 5380 in the system - commands that haven't been issued yet,
126      * and commands that are currently executing.  This means that an 
127      * unlimited number of commands may be queued, letting 
128      * more commands propagate from the higher driver levels giving higher 
129      * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported, 
130      * allowing multiple commands to propagate all the way to a SCSI-II device 
131      * while a command is already executing.
132      *
133      * To solve the multiple-boards-in-the-same-system problem, 
134      * there is a separate instance structure for each instance
135      * of a 5380 in the system.  So, multiple NCR5380 drivers will
136      * be able to coexist with appropriate changes to the high level
137      * SCSI code.  
138      *
139      * A NCR5380_PUBLIC_REVISION macro is provided, with the release
140      * number (updated for each public release) printed by the 
141      * NCR5380_print_options command, which should be called from the 
142      * wrapper detect function, so that I know what release of the driver
143      * users are using.
144      *
145      * Issues specific to the NCR5380 : 
146      *
147      * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead 
148      * piece of hardware that requires you to sit in a loop polling for 
149      * the REQ signal as long as you are connected.  Some devices are 
150      * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect 
151      * while doing long seek operations.
152      * 
153      * The workaround for this is to keep track of devices that have
154      * disconnected.  If the device hasn't disconnected, for commands that
155      * should disconnect, we do something like 
156      *
157      * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
158      * 
159      * Some tweaking of N and M needs to be done.  An algorithm based 
160      * on "time to data" would give the best results as long as short time
161      * to datas (ie, on the same track) were considered, however these 
162      * broken devices are the exception rather than the rule and I'd rather
163      * spend my time optimizing for the normal case.
164      *
165      * Architecture :
166      *
167      * At the heart of the design is a coroutine, NCR5380_main,
168      * which is started when not running by the interrupt handler,
169      * timer, and queue command function.  It attempts to establish
170      * I_T_L or I_T_L_Q nexuses by removing the commands from the 
171      * issue queue and calling NCR5380_select() if a nexus 
172      * is not established. 
173      *
174      * Once a nexus is established, the NCR5380_information_transfer()
175      * phase goes through the various phases as instructed by the target.
176      * if the target goes into MSG IN and sends a DISCONNECT message,
177      * the command structure is placed into the per instance disconnected
178      * queue, and NCR5380_main tries to find more work.  If USLEEP
179      * was defined, and the target is idle for too long, the system
180      * 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      * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
204      *	for commands that return with a CHECK CONDITION status. 
205      *
206      * LINKED - if defined, linked commands are supported.
207      *
208      * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
209      *
210      * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
211      *
212      * These macros MUST be defined :
213      * 
214      * NCR5380_read(register)  - read from the specified register
215      *
216      * NCR5380_write(register, value) - write to the specific register 
217      *
218      * Either real DMA *or* pseudo DMA may be implemented
219      * REAL functions : 
220      * NCR5380_REAL_DMA should be defined if real DMA is to be used.
221      * Note that the DMA setup functions should return the number of bytes 
222      *	that they were able to program the controller for.
223      *
224      * Also note that generic i386/PC versions of these macros are 
225      *	available as NCR5380_i386_dma_write_setup,
226      *	NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
227      *
228      * NCR5380_dma_write_setup(instance, src, count) - initialize
229      * NCR5380_dma_read_setup(instance, dst, count) - initialize
230      * NCR5380_dma_residual(instance); - residual count
231      *
232      * PSEUDO functions :
233      * NCR5380_pwrite(instance, src, count)
234      * NCR5380_pread(instance, dst, count);
235      *
236      * If nothing specific to this implementation needs doing (ie, with external
237      * hardware), you must also define 
238      *  
239      * NCR5380_queue_command
240      * NCR5380_reset
241      * NCR5380_abort
242      * NCR5380_proc_info
243      *
244      * to be the global entry points into the specific driver, ie 
245      * #define NCR5380_queue_command t128_queue_command.
246      *
247      * If this is not done, the routines will be defined as static functions
248      * with the NCR5380* names and the user must provide a globally
249      * accessible wrapper function.
250      *
251      * The generic driver is initialized by calling NCR5380_init(instance),
252      * after setting the appropriate host specific fields and ID.  If the 
253      * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
254      * possible) function may be used.  Before the specific driver initialization
255      * code finishes, NCR5380_print_options should be called.
256      */
257     
258     static struct Scsi_Host *first_instance = NULL;
259     static Scsi_Host_Template *the_template = NULL;
260     
261     /* Macros ease life... :-) */
262     #define	SETUP_HOSTDATA(in)				\
263         struct NCR5380_hostdata *hostdata =			\
264     	(struct NCR5380_hostdata *)(in)->hostdata
265     #define	HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)
266     
267     #define	NEXT(cmd)	((Scsi_Cmnd *)((cmd)->host_scribble))
268     #define	NEXTADDR(cmd)	((Scsi_Cmnd **)&((cmd)->host_scribble))
269     
270     #define	HOSTNO		instance->host_no
271     #define	H_NO(cmd)	(cmd)->host->host_no
272     
273     #ifdef SUPPORT_TAGS
274     
275     /*
276      * Functions for handling tagged queuing
277      * =====================================
278      *
279      * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
280      *
281      * Using consecutive numbers for the tags is no good idea in my eyes. There
282      * could be wrong re-usings if the counter (8 bit!) wraps and some early
283      * command has been preempted for a long time. My solution: a bitfield for
284      * remembering used tags.
285      *
286      * There's also the problem that each target has a certain queue size, but we
287      * cannot know it in advance :-( We just see a QUEUE_FULL status being
288      * returned. So, in this case, the driver internal queue size assumption is
289      * reduced to the number of active tags if QUEUE_FULL is returned by the
290      * target. The command is returned to the mid-level, but with status changed
291      * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
292      * correctly.
293      *
294      * We're also not allowed running tagged commands as long as an untagged
295      * command is active. And REQUEST SENSE commands after a contingent allegiance
296      * condition _must_ be untagged. To keep track whether an untagged command has
297      * been issued, the host->busy array is still employed, as it is without
298      * support for tagged queuing.
299      *
300      * One could suspect that there are possible race conditions between
301      * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
302      * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
303      * which already guaranteed to be running at most once. It is also the only
304      * place where tags/LUNs are allocated. So no other allocation can slip
305      * between that pair, there could only happen a reselection, which can free a
306      * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
307      * important: the tag bit must be cleared before 'nr_allocated' is decreased.
308      */
309     
310     /* -1 for TAG_NONE is not possible with unsigned char cmd->tag */
311     #undef TAG_NONE
312     #define TAG_NONE 0xff
313     
314     /* For the m68k, the number of bits in 'allocated' must be a multiple of 32! */
315     #if (MAX_TAGS % 32) != 0
316     #error "MAX_TAGS must be a multiple of 32!"
317     #endif
318     
319     typedef struct {
320         char	allocated[MAX_TAGS/8];
321         int		nr_allocated;
322         int		queue_size;
323     } TAG_ALLOC;
324     
325     static TAG_ALLOC TagAlloc[8][8]; /* 8 targets and 8 LUNs */
326     
327     
328     static void __init init_tags( void )
329     {
330         int target, lun;
331         TAG_ALLOC *ta;
332         
333         if (!setup_use_tagged_queuing)
334     	return;
335         
336         for( target = 0; target < 8; ++target ) {
337     	for( lun = 0; lun < 8; ++lun ) {
338     	    ta = &TagAlloc[target][lun];
339     	    memset( &ta->allocated, 0, MAX_TAGS/8 );
340     	    ta->nr_allocated = 0;
341     	    /* At the beginning, assume the maximum queue size we could
342     	     * support (MAX_TAGS). This value will be decreased if the target
343     	     * returns QUEUE_FULL status.
344     	     */
345     	    ta->queue_size = MAX_TAGS;
346     	}
347         }
348     }
349     
350     
351     /* Check if we can issue a command to this LUN: First see if the LUN is marked
352      * busy by an untagged command. If the command should use tagged queuing, also
353      * check that there is a free tag and the target's queue won't overflow. This
354      * function should be called with interrupts disabled to avoid race
355      * conditions.
356      */ 
357     
358     static int is_lun_busy( Scsi_Cmnd *cmd, int should_be_tagged )
359     {
360         SETUP_HOSTDATA(cmd->host);
361     
362         if (hostdata->busy[cmd->target] & (1 << cmd->lun))
363     	return( 1 );
364         if (!should_be_tagged ||
365     	!setup_use_tagged_queuing || !cmd->device->tagged_supported)
366     	return( 0 );
367         if (TagAlloc[cmd->target][cmd->lun].nr_allocated >=
368     	TagAlloc[cmd->target][cmd->lun].queue_size ) {
369     	TAG_PRINTK( "scsi%d: target %d lun %d: no free tags\n",
370     		    H_NO(cmd), cmd->target, cmd->lun );
371     	return( 1 );
372         }
373         return( 0 );
374     }
375     
376     
377     /* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
378      * must be called before!), or reserve the LUN in 'busy' if the command is
379      * untagged.
380      */
381     
382     static void cmd_get_tag( Scsi_Cmnd *cmd, int should_be_tagged )
383     {
384         SETUP_HOSTDATA(cmd->host);
385     
386         /* If we or the target don't support tagged queuing, allocate the LUN for
387          * an untagged command.
388          */
389         if (!should_be_tagged ||
390     	!setup_use_tagged_queuing || !cmd->device->tagged_supported) {
391     	cmd->tag = TAG_NONE;
392     	hostdata->busy[cmd->target] |= (1 << cmd->lun);
393     	TAG_PRINTK( "scsi%d: target %d lun %d now allocated by untagged "
394     		    "command\n", H_NO(cmd), cmd->target, cmd->lun );
395         }
396         else {
397     	TAG_ALLOC *ta = &TagAlloc[cmd->target][cmd->lun];
398     
399     	cmd->tag = find_first_zero_bit( &ta->allocated, MAX_TAGS );
400     	set_bit( cmd->tag, &ta->allocated );
401     	ta->nr_allocated++;
402     	TAG_PRINTK( "scsi%d: using tag %d for target %d lun %d "
403     		    "(now %d tags in use)\n",
404     		    H_NO(cmd), cmd->tag, cmd->target, cmd->lun,
405     		    ta->nr_allocated );
406         }
407     }
408     
409     
410     /* Mark the tag of command 'cmd' as free, or in case of an untagged command,
411      * unlock the LUN.
412      */
413     
414     static void cmd_free_tag( Scsi_Cmnd *cmd )
415     {
416         SETUP_HOSTDATA(cmd->host);
417     
418         if (cmd->tag == TAG_NONE) {
419     	hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
420     	TAG_PRINTK( "scsi%d: target %d lun %d untagged cmd finished\n",
421     		    H_NO(cmd), cmd->target, cmd->lun );
422         }
423         else if (cmd->tag >= MAX_TAGS) {
424     	printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
425     		H_NO(cmd), cmd->tag );
426         }
427         else {
428     	TAG_ALLOC *ta = &TagAlloc[cmd->target][cmd->lun];
429     	clear_bit( cmd->tag, &ta->allocated );
430     	ta->nr_allocated--;
431     	TAG_PRINTK( "scsi%d: freed tag %d for target %d lun %d\n",
432     		    H_NO(cmd), cmd->tag, cmd->target, cmd->lun );
433         }
434     }
435     
436     
437     static void free_all_tags( void )
438     {
439         int target, lun;
440         TAG_ALLOC *ta;
441     
442         if (!setup_use_tagged_queuing)
443     	return;
444         
445         for( target = 0; target < 8; ++target ) {
446     	for( lun = 0; lun < 8; ++lun ) {
447     	    ta = &TagAlloc[target][lun];
448     	    memset( &ta->allocated, 0, MAX_TAGS/8 );
449     	    ta->nr_allocated = 0;
450     	}
451         }
452     }
453     
454     #endif /* SUPPORT_TAGS */
455     
456     
457     /*
458      * Function: void merge_contiguous_buffers( Scsi_Cmnd *cmd )
459      *
460      * Purpose: Try to merge several scatter-gather requests into one DMA
461      *    transfer. This is possible if the scatter buffers lie on
462      *    physical contiguous addresses.
463      *
464      * Parameters: Scsi_Cmnd *cmd
465      *    The command to work on. The first scatter buffer's data are
466      *    assumed to be already transfered into ptr/this_residual.
467      */
468     
469     static void merge_contiguous_buffers( Scsi_Cmnd *cmd )
470     {
471         unsigned long endaddr;
472     #if (NDEBUG & NDEBUG_MERGING)
473         unsigned long oldlen = cmd->SCp.this_residual;
474         int		  cnt = 1;
475     #endif
476     
477         for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
478     	 cmd->SCp.buffers_residual &&
479     	 virt_to_phys(cmd->SCp.buffer[1].address) == endaddr; ) {
480     	
481     	MER_PRINTK("VTOP(%p) == %08lx -> merging\n",
482     		   cmd->SCp.buffer[1].address, endaddr);
483     #if (NDEBUG & NDEBUG_MERGING)
484     	++cnt;
485     #endif
486     	++cmd->SCp.buffer;
487     	--cmd->SCp.buffers_residual;
488     	cmd->SCp.this_residual += cmd->SCp.buffer->length;
489     	endaddr += cmd->SCp.buffer->length;
490         }
491     #if (NDEBUG & NDEBUG_MERGING)
492         if (oldlen != cmd->SCp.this_residual)
493     	MER_PRINTK("merged %d buffers from %p, new length %08x\n",
494     		   cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
495     #endif
496     }
497     
498     /*
499      * Function : void initialize_SCp(Scsi_Cmnd *cmd)
500      *
501      * Purpose : initialize the saved data pointers for cmd to point to the 
502      *	start of the buffer.
503      *
504      * Inputs : cmd - Scsi_Cmnd structure to have pointers reset.
505      */
506     
507     static __inline__ void initialize_SCp(Scsi_Cmnd *cmd)
508     {
509         /* 
510          * Initialize the Scsi Pointer field so that all of the commands in the 
511          * various queues are valid.
512          */
513     
514         if (cmd->use_sg) {
515     	cmd->SCp.buffer = (struct scatterlist *) cmd->buffer;
516     	cmd->SCp.buffers_residual = cmd->use_sg - 1;
517     	cmd->SCp.ptr = (char *) cmd->SCp.buffer->address;
518     	cmd->SCp.this_residual = cmd->SCp.buffer->length;
519     	/* ++roman: Try to merge some scatter-buffers if they are at
520     	 * contiguous physical addresses.
521     	 */
522     	merge_contiguous_buffers( cmd );
523         } else {
524     	cmd->SCp.buffer = NULL;
525     	cmd->SCp.buffers_residual = 0;
526     	cmd->SCp.ptr = (char *) cmd->request_buffer;
527     	cmd->SCp.this_residual = cmd->request_bufflen;
528         }
529         
530     }
531     
532     #include <linux/config.h>
533     #include <linux/delay.h>
534     
535     #if 1
536     static struct {
537         unsigned char mask;
538         const char * name;} 
539     signals[] = {{ SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" }, 
540         { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD,  "CD" }, { SR_IO, "IO" }, 
541         { SR_SEL, "SEL" }, {0, NULL}}, 
542     basrs[] = {{BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}},
543     icrs[] = {{ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
544         {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"}, 
545         {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"}, 
546         {0, NULL}},
547     mrs[] = {{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"}, 
548         {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR, 
549         "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
550         {MR_MONITOR_BSY, "MODE MONITOR BSY"},
551         {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"}, 
552         {0, NULL}};
553     
554     /*
555      * Function : void NCR5380_print(struct Scsi_Host *instance)
556      *
557      * Purpose : print the SCSI bus signals for debugging purposes
558      *
559      * Input : instance - which NCR5380
560      */
561     
562     static void NCR5380_print(struct Scsi_Host *instance) {
563         unsigned char status, data, basr, mr, icr, i;
564         unsigned long flags;
565     
566         save_flags(flags);
567         cli();
568         data = NCR5380_read(CURRENT_SCSI_DATA_REG);
569         status = NCR5380_read(STATUS_REG);
570         mr = NCR5380_read(MODE_REG);
571         icr = NCR5380_read(INITIATOR_COMMAND_REG);
572         basr = NCR5380_read(BUS_AND_STATUS_REG);
573         restore_flags(flags);
574         printk("STATUS_REG: %02x ", status);
575         for (i = 0; signals[i].mask ; ++i) 
576     	if (status & signals[i].mask)
577     	    printk(",%s", signals[i].name);
578         printk("\nBASR: %02x ", basr);
579         for (i = 0; basrs[i].mask ; ++i) 
580     	if (basr & basrs[i].mask)
581     	    printk(",%s", basrs[i].name);
582         printk("\nICR: %02x ", icr);
583         for (i = 0; icrs[i].mask; ++i) 
584     	if (icr & icrs[i].mask)
585     	    printk(",%s", icrs[i].name);
586         printk("\nMODE: %02x ", mr);
587         for (i = 0; mrs[i].mask; ++i) 
588     	if (mr & mrs[i].mask)
589     	    printk(",%s", mrs[i].name);
590         printk("\n");
591     }
592     
593     static struct {
594         unsigned char value;
595         const char *name;
596     } phases[] = {
597         {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
598         {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
599         {PHASE_UNKNOWN, "UNKNOWN"}};
600     
601     /* 
602      * Function : void NCR5380_print_phase(struct Scsi_Host *instance)
603      *
604      * Purpose : print the current SCSI phase for debugging purposes
605      *
606      * Input : instance - which NCR5380
607      */
608     
609     static void NCR5380_print_phase(struct Scsi_Host *instance)
610     {
611         unsigned char status;
612         int i;
613     
614         status = NCR5380_read(STATUS_REG);
615         if (!(status & SR_REQ)) 
616     	printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
617         else {
618     	for (i = 0; (phases[i].value != PHASE_UNKNOWN) && 
619     	    (phases[i].value != (status & PHASE_MASK)); ++i); 
620     	printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
621         }
622     }
623     
624     #else /* !NDEBUG */
625     
626     /* dummies... */
627     __inline__ void NCR5380_print(struct Scsi_Host *instance) { };
628     __inline__ void NCR5380_print_phase(struct Scsi_Host *instance) { };
629     
630     #endif
631     
632     /*
633      * ++roman: New scheme of calling NCR5380_main()
634      * 
635      * If we're not in an interrupt, we can call our main directly, it cannot be
636      * already running. Else, we queue it on a task queue, if not 'main_running'
637      * tells us that a lower level is already executing it. This way,
638      * 'main_running' needs not be protected in a special way.
639      *
640      * queue_main() is a utility function for putting our main onto the task
641      * queue, if main_running is false. It should be called only from a
642      * interrupt or bottom half.
643      */
644     
645     #include <linux/tqueue.h>
646     #include <linux/interrupt.h>
647     
648     static volatile int main_running = 0;
649     static struct tq_struct NCR5380_tqueue = {
650         NULL,		/* next */
651         0,			/* sync */
652         (void (*)(void*))NCR5380_main,  /* routine, must have (void *) arg... */
653         NULL		/* data */
654     };
655     
656     static __inline__ void queue_main(void)
657     {
658         if (!main_running) {
659     	/* If in interrupt and NCR5380_main() not already running,
660     	   queue it on the 'immediate' task queue, to be processed
661     	   immediately after the current interrupt processing has
662     	   finished. */
663     	queue_task(&NCR5380_tqueue, &tq_immediate);
664     	mark_bh(IMMEDIATE_BH);
665         }
666         /* else: nothing to do: the running NCR5380_main() will pick up
667            any newly queued command. */
668     }
669     
670     
671     static inline void NCR5380_all_init (void)
672     {
673         static int done = 0;
674         if (!done) {
675     	INI_PRINTK("scsi : NCR5380_all_init()\n");
676     	done = 1;
677         }
678     }
679     
680      
681     /*
682      * Function : void NCR58380_print_options (struct Scsi_Host *instance)
683      *
684      * Purpose : called by probe code indicating the NCR5380 driver
685      *	     options that were selected.
686      *
687      * Inputs : instance, pointer to this instance.  Unused.
688      */
689     
690     static void __init NCR5380_print_options (struct Scsi_Host *instance)
691     {
692         printk(" generic options"
693     #ifdef AUTOSENSE 
694         " AUTOSENSE"
695     #endif
696     #ifdef REAL_DMA
697         " REAL DMA"
698     #endif
699     #ifdef PARITY
700         " PARITY"
701     #endif
702     #ifdef SUPPORT_TAGS
703         " SCSI-2 TAGGED QUEUING"
704     #endif
705         );
706         printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
707     }
708     
709     /*
710      * Function : void NCR5380_print_status (struct Scsi_Host *instance)
711      *
712      * Purpose : print commands in the various queues, called from
713      *	NCR5380_abort and NCR5380_debug to aid debugging.
714      *
715      * Inputs : instance, pointer to this instance.  
716      */
717     
718     static void NCR5380_print_status (struct Scsi_Host *instance)
719     {
720         char *pr_bfr;
721         char *start;
722         int len;
723     
724         NCR_PRINT(NDEBUG_ANY);
725         NCR_PRINT_PHASE(NDEBUG_ANY);
726     
727         pr_bfr = (char *) __get_free_page(GFP_ATOMIC);
728         if (!pr_bfr) {
729     	printk("NCR5380_print_status: no memory for print buffer\n");
730     	return;
731         }
732         len = NCR5380_proc_info(pr_bfr, &start, 0, PAGE_SIZE, HOSTNO, 0);
733         pr_bfr[len] = 0;
734         printk("\n%s\n", pr_bfr);
735         free_page((unsigned long) pr_bfr);
736     }
737     
738     
739     /******************************************/
740     /*
741      * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
742      *
743      * *buffer: I/O buffer
744      * **start: if inout == FALSE pointer into buffer where user read should start
745      * offset: current offset
746      * length: length of buffer
747      * hostno: Scsi_Host host_no
748      * inout: TRUE - user is writing; FALSE - user is reading
749      *
750      * Return the number of bytes read from or written
751     */
752     
753     #undef SPRINTF
754     #define SPRINTF(fmt,args...) \
755       do { if (pos + strlen(fmt) + 20 /* slop */ < buffer + length) \
756     	 pos += sprintf(pos, fmt , ## args); } while(0)
757     static
758     char *lprint_Scsi_Cmnd (Scsi_Cmnd *cmd, char *pos, char *buffer, int length);
759     
760     #ifndef NCR5380_proc_info
761     static
762     #endif
763     int NCR5380_proc_info (char *buffer, char **start, off_t offset,
764     		       int length, int hostno, int inout)
765     {
766         char *pos = buffer;
767         struct Scsi_Host *instance;
768         struct NCR5380_hostdata *hostdata;
769         Scsi_Cmnd *ptr;
770         unsigned long flags;
771         off_t begin = 0;
772     #define check_offset()				\
773         do {					\
774     	if (pos - buffer < offset - begin) {	\
775     	    begin += pos - buffer;		\
776     	    pos = buffer;			\
777     	}					\
778         } while (0)
779     
780         for (instance = first_instance; instance && HOSTNO != hostno;
781     	 instance = instance->next)
782     	;
783         if (!instance)
784     	return(-ESRCH);
785         hostdata = (struct NCR5380_hostdata *)instance->hostdata;
786     
787         if (inout) { /* Has data been written to the file ? */
788     	return(-ENOSYS);  /* Currently this is a no-op */
789         }
790         SPRINTF("NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
791         check_offset();
792         save_flags(flags);
793         cli();
794         SPRINTF("NCR5380: coroutine is%s running.\n", main_running ? "" : "n't");
795         check_offset();
796         if (!hostdata->connected)
797     	SPRINTF("scsi%d: no currently connected command\n", HOSTNO);
798         else
799     	pos = lprint_Scsi_Cmnd ((Scsi_Cmnd *) hostdata->connected,
800     				pos, buffer, length);
801         SPRINTF("scsi%d: issue_queue\n", HOSTNO);
802         check_offset();
803         for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = NEXT(ptr)) {
804     	pos = lprint_Scsi_Cmnd (ptr, pos, buffer, length);
805     	check_offset();
806         }
807     
808         SPRINTF("scsi%d: disconnected_queue\n", HOSTNO);
809         check_offset();
810         for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
811     	 ptr = NEXT(ptr)) {
812     	pos = lprint_Scsi_Cmnd (ptr, pos, buffer, length);
813     	check_offset();
814         }
815     
816         restore_flags(flags);
817         *start = buffer + (offset - begin);
818         if (pos - buffer < offset - begin)
819     	return 0;
820         else if (pos - buffer - (offset - begin) < length)
821     	return pos - buffer - (offset - begin);
822         return length;
823     }
824     
825     static char *
826     lprint_Scsi_Cmnd (Scsi_Cmnd *cmd, char *pos, char *buffer, int length)
827     {
828         int i, s;
829         unsigned char *command;
830         SPRINTF("scsi%d: destination target %d, lun %d\n",
831     	    H_NO(cmd), cmd->target, cmd->lun);
832         SPRINTF("        command = ");
833         command = cmd->cmnd;
834         SPRINTF("%2d (0x%02x)", command[0], command[0]);
835         for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
836     	SPRINTF(" %02x", command[i]);
837         SPRINTF("\n");
838         return pos;
839     }
840     
841     
842     /* 
843      * Function : void NCR5380_init (struct Scsi_Host *instance)
844      *
845      * Purpose : initializes *instance and corresponding 5380 chip.
846      *
847      * Inputs : instance - instantiation of the 5380 driver.  
848      *
849      * Notes : I assume that the host, hostno, and id bits have been
850      * 	set correctly.  I don't care about the irq and other fields. 
851      * 
852      */
853     
854     static void __init NCR5380_init (struct Scsi_Host *instance, int flags)
855     {
856         int i;
857         SETUP_HOSTDATA(instance);
858     
859         NCR5380_all_init();
860     
861         hostdata->aborted = 0;
862         hostdata->id_mask = 1 << instance->this_id;
863         hostdata->id_higher_mask = 0;
864         for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
865     	if (i > hostdata->id_mask)
866     	    hostdata->id_higher_mask |= i;
867         for (i = 0; i < 8; ++i)
868     	hostdata->busy[i] = 0;
869     #ifdef SUPPORT_TAGS
870         init_tags();
871     #endif
872     #if defined (REAL_DMA)
873         hostdata->dma_len = 0;
874     #endif
875         hostdata->targets_present = 0;
876         hostdata->connected = NULL;
877         hostdata->issue_queue = NULL;
878         hostdata->disconnected_queue = NULL;
879         hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;
880     
881         if (!the_template) {
882     	the_template = instance->hostt;
883     	first_instance = instance;
884         }
885     	
886     
887     #ifndef AUTOSENSE
888         if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1))
889     	 printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n"
890     	        "        without AUTOSENSE option, contingent allegiance conditions may\n"
891     	        "        be incorrectly cleared.\n", HOSTNO);
892     #endif /* def AUTOSENSE */
893     
894         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
895         NCR5380_write(MODE_REG, MR_BASE);
896         NCR5380_write(TARGET_COMMAND_REG, 0);
897         NCR5380_write(SELECT_ENABLE_REG, 0);
898     }
899     
900     /* 
901      * Function : int NCR5380_queue_command (Scsi_Cmnd *cmd, 
902      *	void (*done)(Scsi_Cmnd *)) 
903      *
904      * Purpose :  enqueues a SCSI command
905      *
906      * Inputs : cmd - SCSI command, done - function called on completion, with
907      *	a pointer to the command descriptor.
908      * 
909      * Returns : 0
910      *
911      * Side effects : 
912      *      cmd is added to the per instance issue_queue, with minor 
913      *	twiddling done to the host specific fields of cmd.  If the 
914      *	main coroutine is not running, it is restarted.
915      *
916      */
917     
918     /* Only make static if a wrapper function is used */
919     #ifndef NCR5380_queue_command
920     static
921     #endif
922     int NCR5380_queue_command (Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
923     {
924         SETUP_HOSTDATA(cmd->host);
925         Scsi_Cmnd *tmp;
926         unsigned long flags;
927         extern int update_timeout(Scsi_Cmnd * SCset, int timeout);
928     
929     #if (NDEBUG & NDEBUG_NO_WRITE)
930         switch (cmd->cmnd[0]) {
931         case WRITE_6:
932         case WRITE_10:
933     	printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
934     	       H_NO(cmd));
935     	cmd->result = (DID_ERROR << 16);
936     	done(cmd);
937     	return 0;
938         }
939     #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
940     
941     
942     #ifdef NCR5380_STATS
943     # if 0
944         if (!hostdata->connected && !hostdata->issue_queue &&
945     	!hostdata->disconnected_queue) {
946     	hostdata->timebase = jiffies;
947         }
948     # endif
949     # ifdef NCR5380_STAT_LIMIT
950         if (cmd->request_bufflen > NCR5380_STAT_LIMIT)
951     # endif
952     	switch (cmd->cmnd[0])
953     	{
954     	    case WRITE:
955     	    case WRITE_6:
956     	    case WRITE_10:
957     		hostdata->time_write[cmd->target] -= (jiffies - hostdata->timebase);
958     		hostdata->bytes_write[cmd->target] += cmd->request_bufflen;
959     		hostdata->pendingw++;
960     		break;
961     	    case READ:
962     	    case READ_6:
963     	    case READ_10:
964     		hostdata->time_read[cmd->target] -= (jiffies - hostdata->timebase);
965     		hostdata->bytes_read[cmd->target] += cmd->request_bufflen;
966     		hostdata->pendingr++;
967     		break;
968     	}
969     #endif
970     
971         /* 
972          * We use the host_scribble field as a pointer to the next command  
973          * in a queue 
974          */
975     
976         NEXT(cmd) = NULL;
977         cmd->scsi_done = done;
978     
979         cmd->result = 0;
980     
981     
982         /* 
983          * Insert the cmd into the issue queue. Note that REQUEST SENSE 
984          * commands are added to the head of the queue since any command will
985          * clear the contingent allegiance condition that exists and the 
986          * sense data is only guaranteed to be valid while the condition exists.
987          */
988     
989         save_flags(flags);
990         cli();
991         /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
992          * Otherwise a running NCR5380_main may steal the lock.
993          * Lock before actually inserting due to fairness reasons explained in
994          * atari_scsi.c. If we insert first, then it's impossible for this driver
995          * to release the lock.
996          * Stop timer for this command while waiting for the lock, or timeouts
997          * may happen (and they really do), and it's no good if the command doesn't
998          * appear in any of the queues.
999          * ++roman: Just disabling the NCR interrupt isn't sufficient here,
1000          * because also a timer int can trigger an abort or reset, which would
1001          * alter queues and touch the lock.
1002          */
1003         if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1004     	LIST(cmd, hostdata->issue_queue);
1005     	NEXT(cmd) = hostdata->issue_queue;
1006     	hostdata->issue_queue = cmd;
1007         } else {
1008     	for (tmp = (Scsi_Cmnd *)hostdata->issue_queue;
1009     	     NEXT(tmp); tmp = NEXT(tmp))
1010     	    ;
1011     	LIST(cmd, tmp);
1012     	NEXT(tmp) = cmd;
1013         }
1014     
1015         restore_flags(flags);
1016     
1017         QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd),
1018     	      (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
1019     
1020         /* If queue_command() is called from an interrupt (real one or bottom
1021          * half), we let queue_main() do the job of taking care about main. If it
1022          * is already running, this is a no-op, else main will be queued.
1023          *
1024          * If we're not in an interrupt, we can call NCR5380_main()
1025          * unconditionally, because it cannot be already running.
1026          */
1027         if (in_interrupt() || ((flags >> 8) & 7) >= 6)
1028     	queue_main();
1029         else
1030     	NCR5380_main();
1031         return 0;
1032     }
1033     
1034     /*
1035      * Function : NCR5380_main (void) 
1036      *
1037      * Purpose : NCR5380_main is a coroutine that runs as long as more work can 
1038      *	be done on the NCR5380 host adapters in a system.  Both 
1039      *	NCR5380_queue_command() and NCR5380_intr() will try to start it 
1040      *	in case it is not running.
1041      * 
1042      * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should 
1043      *  reenable them.  This prevents reentrancy and kernel stack overflow.
1044      */ 	
1045         
1046     static void NCR5380_main (void)
1047     {
1048         Scsi_Cmnd *tmp, *prev;
1049         struct Scsi_Host *instance = first_instance;
1050         struct NCR5380_hostdata *hostdata = HOSTDATA(instance);
1051         int done;
1052         unsigned long flags;
1053         
1054         /*
1055          * We run (with interrupts disabled) until we're sure that none of 
1056          * the host adapters have anything that can be done, at which point 
1057          * we set main_running to 0 and exit.
1058          *
1059          * Interrupts are enabled before doing various other internal 
1060          * instructions, after we've decided that we need to run through
1061          * the loop again.
1062          *
1063          * this should prevent any race conditions.
1064          * 
1065          * ++roman: Just disabling the NCR interrupt isn't sufficient here,
1066          * because also a timer int can trigger an abort or reset, which can
1067          * alter queues and touch the Falcon lock.
1068          */
1069     
1070         /* Tell int handlers main() is now already executing.  Note that
1071            no races are possible here. If an int comes in before
1072            'main_running' is set here, and queues/executes main via the
1073            task queue, it doesn't do any harm, just this instance of main
1074            won't find any work left to do. */
1075         if (main_running)
1076         	return;
1077         main_running = 1;
1078     
1079         save_flags(flags);
1080         do {
1081     	cli(); /* Freeze request queues */
1082     	done = 1;
1083     	
1084     	if (!hostdata->connected) {
1085     	    MAIN_PRINTK( "scsi%d: not connected\n", HOSTNO );
1086     	    /*
1087     	     * Search through the issue_queue for a command destined
1088     	     * for a target that's not busy.
1089     	     */
1090     #if (NDEBUG & NDEBUG_LISTS)
1091     	    for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL;
1092     		 tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
1093     		;
1094     	    if ((tmp == prev) && tmp) printk(" LOOP\n");/* else printk("\n");*/
1095     #endif
1096     	    for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, 
1097     		 prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp) ) {
1098     
1099     #if (NDEBUG & NDEBUG_LISTS)
1100     		if (prev != tmp)
1101     		    printk("MAIN tmp=%p   target=%d   busy=%d lun=%d\n",
1102     			   tmp, tmp->target, hostdata->busy[tmp->target],
1103     			   tmp->lun);
1104     #endif
1105     		/*  When we find one, remove it from the issue queue. */
1106     		/* ++guenther: possible race with Falcon locking */
1107     		if (
1108     #ifdef SUPPORT_TAGS
1109     		    !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
1110     #else
1111     		    !(hostdata->busy[tmp->target] & (1 << tmp->lun))
1112     #endif
1113     		    ) {
1114     		    cli(); /* ++guenther: just to be sure, this must be atomic */
1115     		    if (prev) {
1116     		        REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
1117     			NEXT(prev) = NEXT(tmp);
1118     		    } else {
1119     		        REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
1120     			hostdata->issue_queue = NEXT(tmp);
1121     		    }
1122     		    NEXT(tmp) = NULL;
1123     		    
1124     		    /* reenable interrupts after finding one */
1125     		    restore_flags(flags);
1126     		    
1127     		    /* 
1128     		     * Attempt to establish an I_T_L nexus here. 
1129     		     * On success, instance->hostdata->connected is set.
1130     		     * On failure, we must add the command back to the
1131     		     *   issue queue so we can keep trying.	
1132     		     */
1133     		    MAIN_PRINTK("scsi%d: main(): command for target %d "
1134     				"lun %d removed from issue_queue\n",
1135     				HOSTNO, tmp->target, tmp->lun);
1136     		    /* 
1137     		     * REQUEST SENSE commands are issued without tagged
1138     		     * queueing, even on SCSI-II devices because the 
1139     		     * contingent allegiance condition exists for the 
1140     		     * entire unit.
1141     		     */
1142     		    /* ++roman: ...and the standard also requires that
1143     		     * REQUEST SENSE command are untagged.
1144     		     */
1145     		    
1146     #ifdef SUPPORT_TAGS
1147     		    cmd_get_tag( tmp, tmp->cmnd[0] != REQUEST_SENSE );
1148     #endif
1149     		    if (!NCR5380_select(instance, tmp, 
1150     			    (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : 
1151     			    TAG_NEXT)) {
1152     			break;
1153     		    } else {
1154     			cli();
1155     			LIST(tmp, hostdata->issue_queue);
1156     			NEXT(tmp) = hostdata->issue_queue;
1157     			hostdata->issue_queue = tmp;
1158     #ifdef SUPPORT_TAGS
1159     			cmd_free_tag( tmp );
1160     #endif
1161     			restore_flags(flags);
1162     			MAIN_PRINTK("scsi%d: main(): select() failed, "
1163     				    "returned to issue_queue\n", HOSTNO);
1164     			if (hostdata->connected)
1165     			    break;
1166     		    }
1167     		} /* if target/lun/target queue is not busy */
1168     	    } /* for issue_queue */
1169     	} /* if (!hostdata->connected) */
1170     	if (hostdata->connected 
1171     #ifdef REAL_DMA
1172     	    && !hostdata->dma_len
1173     #endif
1174     	    ) {
1175     	    restore_flags(flags);
1176     	    MAIN_PRINTK("scsi%d: main: performing information transfer\n",
1177     			HOSTNO);
1178     	    NCR5380_information_transfer(instance);
1179     	    MAIN_PRINTK("scsi%d: main: done set false\n", HOSTNO);
1180     	    done = 0;
1181     	}
1182         } while (!done);
1183     
1184         /* Better allow ints _after_ 'main_running' has been cleared, else
1185            an interrupt could believe we'll pick up the work it left for
1186            us, but we won't see it anymore here... */
1187         main_running = 0;
1188         restore_flags(flags);
1189     }
1190     
1191     
1192     #ifdef REAL_DMA
1193     /*
1194      * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
1195      *
1196      * Purpose : Called by interrupt handler when DMA finishes or a phase
1197      *	mismatch occurs (which would finish the DMA transfer).  
1198      *
1199      * Inputs : instance - this instance of the NCR5380.
1200      *
1201      */
1202     
1203     static void NCR5380_dma_complete( struct Scsi_Host *instance )
1204     {
1205         SETUP_HOSTDATA(instance);
1206         int           transfered;
1207         unsigned char **data;
1208         volatile int  *count;
1209     
1210         if (!hostdata->connected) {
1211     	printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
1212     	       "no connected cmd\n", HOSTNO);
1213     	return;
1214         }
1215     
1216         DMA_PRINTK("scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
1217     	       HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
1218     	       NCR5380_read(STATUS_REG));
1219     
1220         if((sun3scsi_dma_finish())) {
1221     	    printk("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n", HOSTNO);
1222     	    printk("please e-mail sammy@oh.verio.com with a description of how this\n");
1223     	    printk("error was produced.\n");
1224     	    machine_halt();
1225         }
1226     
1227         /* make sure we're not stuck in a data phase */
1228         if((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH |
1229     					    BASR_ACK)) ==
1230            (BASR_PHASE_MATCH | BASR_ACK)) {
1231     	    printk("scsi%d: BASR %02x\n", HOSTNO, NCR5380_read(BUS_AND_STATUS_REG));
1232     	    printk("scsi%d: bus stuck in data phase -- probably a
1233      single byte overrun!\n", HOSTNO); 
1234     	    printk("not prepared for this error!\n");
1235     	    printk("please e-mail sammy@oh.verio.com with a description of how this\n");
1236     	    printk("error was produced.\n");
1237     	    machine_halt();
1238         }
1239     
1240     
1241     
1242         (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1243         NCR5380_write(MODE_REG, MR_BASE);
1244         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1245     
1246         transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
1247         hostdata->dma_len = 0;
1248     
1249         data = (unsigned char **) &(hostdata->connected->SCp.ptr);
1250         count = &(hostdata->connected->SCp.this_residual);
1251         *data += transfered;
1252         *count -= transfered;
1253     
1254     }
1255     #endif /* REAL_DMA */
1256     
1257     
1258     /*
1259      * Function : void NCR5380_intr (int irq)
1260      * 
1261      * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1262      *	from the disconnected queue, and restarting NCR5380_main() 
1263      *	as required.
1264      *
1265      * Inputs : int irq, irq that caused this interrupt.
1266      *
1267      */
1268     
1269     static void NCR5380_intr (int irq, void *dev_id, struct pt_regs *regs)
1270     {
1271         struct Scsi_Host *instance = first_instance;
1272         int done = 1;
1273         unsigned char basr;
1274     
1275         INT_PRINTK("scsi%d: NCR5380 irq triggered\n", HOSTNO);
1276     
1277         /* Look for pending interrupts */
1278         basr = NCR5380_read(BUS_AND_STATUS_REG);
1279         INT_PRINTK("scsi%d: BASR=%02x\n", HOSTNO, basr);
1280         /* dispatch to appropriate routine if found and done=0 */
1281         if (basr & BASR_IRQ) {
1282     	NCR_PRINT(NDEBUG_INTR);
1283     	if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
1284     	    done = 0;
1285     	    ENABLE_IRQ();
1286     	    INT_PRINTK("scsi%d: SEL interrupt\n", HOSTNO);
1287     	    NCR5380_reselect(instance);
1288     	    (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1289     	}
1290     	else if (basr & BASR_PARITY_ERROR) {
1291     	    INT_PRINTK("scsi%d: PARITY interrupt\n", HOSTNO);
1292     	    (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1293     	}
1294     	else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1295     	    INT_PRINTK("scsi%d: RESET interrupt\n", HOSTNO);
1296     	    (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1297     	}
1298     	else {
1299     	    /*  
1300     	     * The rest of the interrupt conditions can occur only during a
1301     	     * DMA transfer
1302     	     */
1303     
1304     #if defined(REAL_DMA)
1305     	    /*
1306     	     * We should only get PHASE MISMATCH and EOP interrupts if we have
1307     	     * DMA enabled, so do a sanity check based on the current setting
1308     	     * of the MODE register.
1309     	     */
1310     
1311     	    if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
1312     		((basr & BASR_END_DMA_TRANSFER) || 
1313     		 !(basr & BASR_PHASE_MATCH))) {
1314     		    
1315     		INT_PRINTK("scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
1316     		NCR5380_dma_complete( instance );
1317     		done = 0;
1318     		ENABLE_IRQ();
1319     	    } else
1320     #endif /* REAL_DMA */
1321     	    {
1322     /* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
1323     		if (basr & BASR_PHASE_MATCH)
1324     		    printk(KERN_NOTICE "scsi%d: unknown interrupt, "
1325     			   "BASR 0x%x, MR 0x%x, SR 0x%x\n",
1326     			   HOSTNO, basr, NCR5380_read(MODE_REG),
1327     			   NCR5380_read(STATUS_REG));
1328     		(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1329     	    }
1330     	} /* if !(SELECTION || PARITY) */
1331         } /* BASR & IRQ */
1332         else {
1333     
1334     	printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
1335     	       "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
1336     	       NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
1337     	(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1338         }
1339         
1340         if (!done) {
1341     	INT_PRINTK("scsi%d: in int routine, calling main\n", HOSTNO);
1342     	/* Put a call to NCR5380_main() on the queue... */
1343     	queue_main();
1344         }
1345     }
1346     
1347     #ifdef NCR5380_STATS
1348     static void collect_stats(struct NCR5380_hostdata* hostdata, Scsi_Cmnd* cmd)
1349     {
1350     # ifdef NCR5380_STAT_LIMIT
1351         if (cmd->request_bufflen > NCR5380_STAT_LIMIT)
1352     # endif
1353     	switch (cmd->cmnd[0])
1354     	{
1355     	    case WRITE:
1356     	    case WRITE_6:
1357     	    case WRITE_10:
1358     		hostdata->time_write[cmd->target] += (jiffies - hostdata->timebase);
1359     		/*hostdata->bytes_write[cmd->target] += cmd->request_bufflen;*/
1360     		hostdata->pendingw--;
1361     		break;
1362     	    case READ:
1363     	    case READ_6:
1364     	    case READ_10:
1365     		hostdata->time_read[cmd->target] += (jiffies - hostdata->timebase);
1366     		/*hostdata->bytes_read[cmd->target] += cmd->request_bufflen;*/
1367     		hostdata->pendingr--;
1368     		break;
1369     	}
1370     }
1371     #endif
1372     
1373     /* 
1374      * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd, 
1375      *	int tag);
1376      *
1377      * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1378      *	including ARBITRATION, SELECTION, and initial message out for 
1379      *	IDENTIFY and queue messages. 
1380      *
1381      * Inputs : instance - instantiation of the 5380 driver on which this 
1382      * 	target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for 
1383      *	new tag, TAG_NONE for untagged queueing, otherwise set to the tag for 
1384      *	the command that is presently connected.
1385      * 
1386      * Returns : -1 if selection could not execute for some reason,
1387      *	0 if selection succeeded or failed because the target 
1388      * 	did not respond.
1389      *
1390      * Side effects : 
1391      * 	If bus busy, arbitration failed, etc, NCR5380_select() will exit 
1392      *		with registers as they should have been on entry - ie
1393      *		SELECT_ENABLE will be set appropriately, the NCR5380
1394      *		will cease to drive any SCSI bus signals.
1395      *
1396      *	If successful : I_T_L or I_T_L_Q nexus will be established, 
1397      *		instance->connected will be set to cmd.  
1398      * 		SELECT interrupt will be disabled.
1399      *
1400      *	If failed (no target) : cmd->scsi_done() will be called, and the 
1401      *		cmd->result host byte set to DID_BAD_TARGET.
1402      */
1403     
1404     static int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd, int tag)
1405     {
1406         SETUP_HOSTDATA(instance);
1407         unsigned char tmp[3], phase;
1408         unsigned char *data;
1409         int len;
1410         unsigned long timeout;
1411         unsigned long flags;
1412     
1413         hostdata->restart_select = 0;
1414         NCR_PRINT(NDEBUG_ARBITRATION);
1415         ARB_PRINTK("scsi%d: starting arbitration, id = %d\n", HOSTNO,
1416     	       instance->this_id);
1417     
1418         /* 
1419          * Set the phase bits to 0, otherwise the NCR5380 won't drive the 
1420          * data bus during SELECTION.
1421          */
1422     
1423         save_flags(flags);
1424         cli();
1425         if (hostdata->connected) {
1426     	restore_flags(flags);
1427     	return -1;
1428         }
1429         NCR5380_write(TARGET_COMMAND_REG, 0);
1430     
1431     
1432         /* 
1433          * Start arbitration.
1434          */
1435         
1436         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1437         NCR5380_write(MODE_REG, MR_ARBITRATE);
1438     
1439         restore_flags(flags);
1440     
1441         /* Wait for arbitration logic to complete */
1442     #if NCR_TIMEOUT
1443         {
1444           unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
1445     
1446           while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS)
1447     	   && time_before(jiffies, timeout) && !hostdata->connected)
1448     	;
1449           if (time_after_eq(jiffies, timeout))
1450           {
1451     	printk("scsi : arbitration timeout at %d\n", __LINE__);
1452     	NCR5380_write(MODE_REG, MR_BASE);
1453     	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1454     	return -1;
1455           }
1456         }
1457     #else /* NCR_TIMEOUT */
1458         while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS)
1459     	 && !hostdata->connected);
1460     #endif
1461     
1462         ARB_PRINTK("scsi%d: arbitration complete\n", HOSTNO);
1463     
1464         if (hostdata->connected) {
1465     	NCR5380_write(MODE_REG, MR_BASE); 
1466     	return -1;
1467         }
1468         /* 
1469          * The arbitration delay is 2.2us, but this is a minimum and there is 
1470          * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1471          * the integral nature of udelay().
1472          *
1473          */
1474     
1475         udelay(3);
1476     
1477         /* Check for lost arbitration */
1478         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1479     	(NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1480     	(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1481     	hostdata->connected) {
1482     	NCR5380_write(MODE_REG, MR_BASE); 
1483     	ARB_PRINTK("scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
1484     		   HOSTNO);
1485     	return -1;
1486         }
1487     
1488          /* after/during arbitration, BSY should be asserted.
1489     	IBM DPES-31080 Version S31Q works now */
1490          /* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
1491         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL |
1492     					 ICR_ASSERT_BSY ) ;
1493         
1494         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1495     	hostdata->connected) {
1496     	NCR5380_write(MODE_REG, MR_BASE);
1497     	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1498     	ARB_PRINTK("scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
1499     		   HOSTNO);
1500     	return -1;
1501         }
1502     
1503         /* 
1504          * Again, bus clear + bus settle time is 1.2us, however, this is 
1505          * a minimum so we'll udelay ceil(1.2)
1506          */
1507     
1508     #ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
1509         /* ++roman: But some targets (see above :-) seem to need a bit more... */
1510         udelay(15);
1511     #else
1512         udelay(2);
1513     #endif
1514         
1515         if (hostdata->connected) {
1516     	NCR5380_write(MODE_REG, MR_BASE);
1517     	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1518     	return -1;
1519         }
1520     
1521         ARB_PRINTK("scsi%d: won arbitration\n", HOSTNO);
1522     
1523         /* 
1524          * Now that we have won arbitration, start Selection process, asserting 
1525          * the host and target ID's on the SCSI bus.
1526          */
1527     
1528         NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->target)));
1529     
1530         /* 
1531          * Raise ATN while SEL is true before BSY goes false from arbitration,
1532          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1533          * phase immediately after selection.
1534          */
1535     
1536         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | 
1537     	ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
1538         NCR5380_write(MODE_REG, MR_BASE);
1539     
1540         /* 
1541          * Reselect interrupts must be turned off prior to the dropping of BSY,
1542          * otherwise we will trigger an interrupt.
1543          */
1544     
1545         if (hostdata->connected) {
1546     	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1547     	return -1;
1548         }
1549     
1550         NCR5380_write(SELECT_ENABLE_REG, 0);
1551     
1552         /*
1553          * The initiator shall then wait at least two deskew delays and release 
1554          * the BSY signal.
1555          */
1556         udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1557     
1558         /* Reset BSY */
1559         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | 
1560     	ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1561     
1562         /* 
1563          * Something weird happens when we cease to drive BSY - looks
1564          * like the board/chip is letting us do another read before the 
1565          * appropriate propagation delay has expired, and we're confusing
1566          * a BSY signal from ourselves as the target's response to SELECTION.
1567          *
1568          * A small delay (the 'C++' frontend breaks the pipeline with an
1569          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1570          * tighter 'C' code breaks and requires this) solves the problem - 
1571          * the 1 us delay is arbitrary, and only used because this delay will 
1572          * be the same on other platforms and since it works here, it should 
1573          * work there.
1574          *
1575          * wingel suggests that this could be due to failing to wait
1576          * one deskew delay.
1577          */
1578     
1579         udelay(1);
1580     
1581         SEL_PRINTK("scsi%d: selecting target %d\n", HOSTNO, cmd->target);
1582     
1583         /* 
1584          * The SCSI specification calls for a 250 ms timeout for the actual 
1585          * selection.
1586          */
1587     
1588         timeout = jiffies + 25; 
1589     
1590         /* 
1591          * XXX very interesting - we're seeing a bounce where the BSY we 
1592          * asserted is being reflected / still asserted (propagation delay?)
1593          * and it's detecting as true.  Sigh.
1594          */
1595     
1596     #if 0
1597         /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
1598          * IO while SEL is true. But again, there are some disks out the in the
1599          * world that do that nevertheless. (Somebody claimed that this announces
1600          * reselection capability of the target.) So we better skip that test and
1601          * only wait for BSY... (Famous german words: Der Klügere gibt nach :-)
1602          */
1603     
1604         while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & 
1605     	(SR_BSY | SR_IO)));
1606     
1607         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == 
1608     	    (SR_SEL | SR_IO)) {
1609     	    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1610     	    NCR5380_reselect(instance);
1611     	    printk (KERN_ERR "scsi%d: reselection after won arbitration?\n",
1612     		    HOSTNO);
1613     	    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1614     	    return -1;
1615         }
1616     #else
1617         while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY));
1618     #endif
1619     
1620         /* 
1621          * No less than two deskew delays after the initiator detects the 
1622          * BSY signal is true, it shall release the SEL signal and may 
1623          * change the DATA BUS.                                     -wingel
1624          */
1625     
1626         udelay(1);
1627     
1628         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1629     
1630         if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1631     	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1632     	if (hostdata->targets_present & (1 << cmd->target)) {
1633     	    printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
1634     	    if (hostdata->restart_select)
1635     		printk(KERN_NOTICE "\trestart select\n");
1636     	    NCR_PRINT(NDEBUG_ANY);
1637     	    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1638     	    return -1;
1639     	}
1640     	cmd->result = DID_BAD_TARGET << 16;
1641     #ifdef NCR5380_STATS
1642     	collect_stats(hostdata, cmd);
1643     #endif
1644     #ifdef SUPPORT_TAGS
1645     	cmd_free_tag( cmd );
1646     #endif
1647     	cmd->scsi_done(cmd);
1648     	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1649     	SEL_PRINTK("scsi%d: target did not respond within 250ms\n", HOSTNO);
1650     	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1651     	return 0;
1652         } 
1653     
1654         hostdata->targets_present |= (1 << cmd->target);
1655     
1656         /*
1657          * Since we followed the SCSI spec, and raised ATN while SEL 
1658          * was true but before BSY was false during selection, the information
1659          * transfer phase should be a MESSAGE OUT phase so that we can send the
1660          * IDENTIFY message.
1661          * 
1662          * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1663          * message (2 bytes) with a tag ID that we increment with every command
1664          * until it wraps back to 0.
1665          *
1666          * XXX - it turns out that there are some broken SCSI-II devices,
1667          *	     which claim to support tagged queuing but fail when more than
1668          *	     some number of commands are issued at once.
1669          */
1670     
1671         /* Wait for start of REQ/ACK handshake */
1672         while (!(NCR5380_read(STATUS_REG) & SR_REQ));
1673     
1674         SEL_PRINTK("scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
1675     	       HOSTNO, cmd->target);
1676         tmp[0] = IDENTIFY(1, cmd->lun);
1677     
1678     #ifdef SUPPORT_TAGS
1679         if (cmd->tag != TAG_NONE) {
1680     	tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
1681     	tmp[2] = cmd->tag;
1682     	len = 3;
1683         } else 
1684     	len = 1;
1685     #else
1686         len = 1;
1687         cmd->tag=0;
1688     #endif /* SUPPORT_TAGS */
1689     
1690         /* Send message(s) */
1691         data = tmp;
1692         phase = PHASE_MSGOUT;
1693         NCR5380_transfer_pio(instance, &phase, &len, &data);
1694         SEL_PRINTK("scsi%d: nexus established.\n", HOSTNO);
1695         /* XXX need to handle errors here */
1696         hostdata->connected = cmd;
1697     #ifndef SUPPORT_TAGS
1698         hostdata->busy[cmd->target] |= (1 << cmd->lun);
1699     #endif    
1700     
1701         initialize_SCp(cmd);
1702     
1703     
1704         return 0;
1705     }
1706     
1707     /* 
1708      * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance, 
1709      *      unsigned char *phase, int *count, unsigned char **data)
1710      *
1711      * Purpose : transfers data in given phase using polled I/O
1712      *
1713      * Inputs : instance - instance of driver, *phase - pointer to 
1714      *	what phase is expected, *count - pointer to number of 
1715      *	bytes to transfer, **data - pointer to data pointer.
1716      * 
1717      * Returns : -1 when different phase is entered without transferring
1718      *	maximum number of bytes, 0 if all bytes are transfered or exit
1719      *	is in same phase.
1720      *
1721      * 	Also, *phase, *count, *data are modified in place.
1722      *
1723      * XXX Note : handling for bus free may be useful.
1724      */
1725     
1726     /*
1727      * Note : this code is not as quick as it could be, however it 
1728      * IS 100% reliable, and for the actual data transfer where speed
1729      * counts, we will always do a pseudo DMA or DMA transfer.
1730      */
1731     
1732     static int NCR5380_transfer_pio( struct Scsi_Host *instance, 
1733     				 unsigned char *phase, int *count,
1734     				 unsigned char **data)
1735     {
1736         register unsigned char p = *phase, tmp;
1737         register int c = *count;
1738         register unsigned char *d = *data;
1739     
1740         /* 
1741          * The NCR5380 chip will only drive the SCSI bus when the 
1742          * phase specified in the appropriate bits of the TARGET COMMAND
1743          * REGISTER match the STATUS REGISTER
1744          */
1745     
1746         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1747     
1748         do {
1749     	/* 
1750     	 * Wait for assertion of REQ, after which the phase bits will be 
1751     	 * valid 
1752     	 */
1753     	while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ));
1754     
1755     	HSH_PRINTK("scsi%d: REQ detected\n", HOSTNO);
1756     
1757     	/* Check for phase mismatch */	
1758     	if ((tmp & PHASE_MASK) != p) {
1759     	    PIO_PRINTK("scsi%d: phase mismatch\n", HOSTNO);
1760     	    NCR_PRINT_PHASE(NDEBUG_PIO);
1761     	    break;
1762     	}
1763     
1764     	/* Do actual transfer from SCSI bus to / from memory */
1765     	if (!(p & SR_IO)) 
1766     	    NCR5380_write(OUTPUT_DATA_REG, *d);
1767     	else 
1768     	    *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1769     
1770     	++d;
1771     
1772     	/* 
1773     	 * The SCSI standard suggests that in MSGOUT phase, the initiator
1774     	 * should drop ATN on the last byte of the message phase
1775     	 * after REQ has been asserted for the handshake but before
1776     	 * the initiator raises ACK.
1777     	 */
1778     
1779     	if (!(p & SR_IO)) {
1780     	    if (!((p & SR_MSG) && c > 1)) {
1781     		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
1782     		    ICR_ASSERT_DATA);
1783     		NCR_PRINT(NDEBUG_PIO);
1784     		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
1785     			ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1786     	    } else {
1787     		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1788     		    ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1789     		NCR_PRINT(NDEBUG_PIO);
1790     		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
1791     		    ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1792     	    }
1793     	} else {
1794     	    NCR_PRINT(NDEBUG_PIO);
1795     	    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1796     	}
1797     
1798     	while (NCR5380_read(STATUS_REG) & SR_REQ);
1799     
1800     	HSH_PRINTK("scsi%d: req false, handshake complete\n", HOSTNO);
1801     
1802     /*
1803      * We have several special cases to consider during REQ/ACK handshaking : 
1804      * 1.  We were in MSGOUT phase, and we are on the last byte of the 
1805      *	message.  ATN must be dropped as ACK is dropped.
1806      *
1807      * 2.  We are in a MSGIN phase, and we are on the last byte of the  
1808      *	message.  We must exit with ACK asserted, so that the calling
1809      *	code may raise ATN before dropping ACK to reject the message.
1810      *
1811      * 3.  ACK and ATN are clear and the target may proceed as normal.
1812      */
1813     	if (!(p == PHASE_MSGIN && c == 1)) {  
1814     	    if (p == PHASE_MSGOUT && c > 1)
1815     		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1816     	    else
1817     		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1818     	} 
1819         } while (--c);
1820     
1821         PIO_PRINTK("scsi%d: residual %d\n", HOSTNO, c);
1822     
1823         *count = c;
1824         *data = d;
1825         tmp = NCR5380_read(STATUS_REG);
1826         /* The phase read from the bus is valid if either REQ is (already)
1827          * asserted or if ACK hasn't been released yet. The latter is the case if
1828          * we're in MSGIN and all wanted bytes have been received. */
1829         if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
1830     	*phase = tmp & PHASE_MASK;
1831         else 
1832     	*phase = PHASE_UNKNOWN;
1833     
1834         if (!c || (*phase == p))
1835     	return 0;
1836         else 
1837     	return -1;
1838     }
1839     
1840     /*
1841      * Function : do_abort (Scsi_Host *host)
1842      * 
1843      * Purpose : abort the currently established nexus.  Should only be 
1844      * 	called from a routine which can drop into a 
1845      * 
1846      * Returns : 0 on success, -1 on failure.
1847      */
1848     
1849     static int do_abort (struct Scsi_Host *host) 
1850     {
1851         unsigned char tmp, *msgptr, phase;
1852         int len;
1853     
1854         /* Request message out phase */
1855         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1856     
1857         /* 
1858          * Wait for the target to indicate a valid phase by asserting 
1859          * REQ.  Once this happens, we'll have either a MSGOUT phase 
1860          * and can immediately send the ABORT message, or we'll have some 
1861          * other phase and will have to source/sink data.
1862          * 
1863          * We really don't care what value was on the bus or what value
1864          * the target sees, so we just handshake.
1865          */
1866         
1867         while (!(tmp = NCR5380_read(STATUS_REG)) & SR_REQ);
1868     
1869         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1870     
1871         if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1872     	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | 
1873     		      ICR_ASSERT_ACK);
1874     	while (NCR5380_read(STATUS_REG) & SR_REQ);
1875     	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1876         }
1877        
1878         tmp = ABORT;
1879         msgptr = &tmp;
1880         len = 1;
1881         phase = PHASE_MSGOUT;
1882         NCR5380_transfer_pio (host, &phase, &len, &msgptr);
1883     
1884         /*
1885          * If we got here, and the command completed successfully,
1886          * we're about to go into bus free state.
1887          */
1888     
1889         return len ? -1 : 0;
1890     }
1891     
1892     #if defined(REAL_DMA)
1893     /* 
1894      * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance, 
1895      *      unsigned char *phase, int *count, unsigned char **data)
1896      *
1897      * Purpose : transfers data in given phase using either real
1898      *	or pseudo DMA.
1899      *
1900      * Inputs : instance - instance of driver, *phase - pointer to 
1901      *	what phase is expected, *count - pointer to number of 
1902      *	bytes to transfer, **data - pointer to data pointer.
1903      * 
1904      * Returns : -1 when different phase is entered without transferring
1905      *	maximum number of bytes, 0 if all bytes or transfered or exit
1906      *	is in same phase.
1907      *
1908      * 	Also, *phase, *count, *data are modified in place.
1909      *
1910      */
1911     
1912     
1913     static int NCR5380_transfer_dma( struct Scsi_Host *instance, 
1914     				 unsigned char *phase, int *count,
1915     				 unsigned char **data)
1916     {
1917         SETUP_HOSTDATA(instance);
1918         register int c = *count;
1919         register unsigned char p = *phase;
1920         unsigned long flags;
1921     
1922         /* sanity check */
1923         if(!sun3_dma_setup_done) {
1924     	 printk("scsi%d: transfer_dma without setup!\n", HOSTNO);
1925     	 machine_halt();
1926         }
1927     
1928         hostdata->dma_len = c;
1929     
1930         DMA_PRINTK("scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1931     	       HOSTNO, (p & SR_IO) ? "reading" : "writing",
1932     	       c, (p & SR_IO) ? "to" : "from", d);
1933     
1934         /* netbsd turns off ints here, why not be safe and do it too */
1935         save_flags(flags);
1936         cli();
1937         
1938         /* send start chain */
1939         sun3_udc_write(UDC_CHN_START, UDC_CSR);
1940         
1941         if (p & SR_IO) {
1942     	    NCR5380_write(TARGET_COMMAND_REG, 1);
1943     	    NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1944     	    NCR5380_write(INITIATOR_COMMAND_REG, 0);
1945     	    NCR5380_write(MODE_REG, (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
1946     	    NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1947         } else {
1948     	    NCR5380_write(TARGET_COMMAND_REG, 0);
1949     	    NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1950     	    NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_DATA);
1951     	    NCR5380_write(MODE_REG, (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
1952     	    NCR5380_write(START_DMA_SEND_REG, 0);
1953         }
1954     
1955         restore_flags(flags);
1956     
1957         sun3_dma_active = 1;
1958         return 0;
1959     }
1960     #endif /* defined(REAL_DMA) */
1961     
1962     /*
1963      * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1964      *
1965      * Purpose : run through the various SCSI phases and do as the target 
1966      * 	directs us to.  Operates on the currently connected command, 
1967      *	instance->connected.
1968      *
1969      * Inputs : instance, instance for which we are doing commands
1970      *
1971      * Side effects : SCSI things happen, the disconnected queue will be 
1972      *	modified if a command disconnects, *instance->connected will
1973      *	change.
1974      *
1975      * XXX Note : we need to watch for bus free or a reset condition here 
1976      * 	to recover from an unexpected bus free condition.
1977      */
1978      
1979     static void NCR5380_information_transfer (struct Scsi_Host *instance)
1980     {
1981         SETUP_HOSTDATA(instance);
1982         unsigned long flags;
1983         unsigned char msgout = NOP;
1984         int sink = 0;
1985         int len;
1986     #if defined(REAL_DMA)
1987         int transfersize;
1988     #endif
1989         unsigned char *data;
1990         unsigned char phase, tmp, extended_msg[10], old_phase=0xff;
1991         Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
1992     
1993         while (1) {
1994     	tmp = NCR5380_read(STATUS_REG);
1995     	/* We only have a valid SCSI phase when REQ is asserted */
1996     	if (tmp & SR_REQ) {
1997     	    phase = (tmp & PHASE_MASK); 
1998      	    if (phase != old_phase) {
1999     		old_phase = phase;
2000     		NCR_PRINT_PHASE(NDEBUG_INFORMATION);
2001     	    }
2002     
2003     	    if(phase == PHASE_CMDOUT) {
2004     		    void *d;
2005     		    unsigned long count;
2006     
2007     		if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2008     			count = cmd->SCp.buffer->length;
2009     			d = cmd->SCp.buffer->address;
2010     		} else {
2011     			count = cmd->SCp.this_residual;
2012     			d = cmd->SCp.ptr;
2013     		}
2014     #ifdef REAL_DMA
2015     		/* this command setup for dma yet? */
2016     		if((count > SUN3_DMA_MINSIZE) && (sun3_dma_setup_done
2017     						  != cmd))
2018     		{
2019     			if((cmd->request.cmd == 0) || (cmd->request.cmd == 1)) {
2020     				sun3scsi_dma_setup(d, count,
2021     						   cmd->request.cmd);
2022     				sun3_dma_setup_done = cmd;
2023     			}
2024     		}
2025     #endif
2026     	    }
2027     
2028     	    
2029     	    if (sink && (phase != PHASE_MSGOUT)) {
2030     		NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2031     
2032     		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | 
2033     		    ICR_ASSERT_ACK);
2034     		while (NCR5380_read(STATUS_REG) & SR_REQ);
2035     		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
2036     		    ICR_ASSERT_ATN);
2037     		sink = 0;
2038     		continue;
2039     	    }
2040     
2041     	    switch (phase) {
2042     	    case PHASE_DATAOUT:
2043     #if (NDEBUG & NDEBUG_NO_DATAOUT)
2044     		printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
2045     		       "aborted\n", HOSTNO);
2046     		sink = 1;
2047     		do_abort(instance);
2048     		cmd->result = DID_ERROR  << 16;
2049     		cmd->done(cmd);
2050     		return;
2051     #endif
2052     	    case PHASE_DATAIN:
2053     		/* 
2054     		 * If there is no room left in the current buffer in the
2055     		 * scatter-gather list, move onto the next one.
2056     		 */
2057     		if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2058     		    ++cmd->SCp.buffer;
2059     		    --cmd->SCp.buffers_residual;
2060     		    cmd->SCp.this_residual = cmd->SCp.buffer->length;
2061     		    cmd->SCp.ptr = cmd->SCp.buffer->address;
2062     
2063     		    /* ++roman: Try to merge some scatter-buffers if
2064     		     * they are at contiguous physical addresses.
2065     		     */
2066     //		    merge_contiguous_buffers( cmd );
2067     		    INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
2068     			       HOSTNO, cmd->SCp.this_residual,
2069     			       cmd->SCp.buffers_residual);
2070     		}
2071     
2072     		/*
2073     		 * The preferred transfer method is going to be 
2074     		 * PSEUDO-DMA for systems that are strictly PIO,
2075     		 * since we can let the hardware do the handshaking.
2076     		 *
2077     		 * For this to work, we need to know the transfersize
2078     		 * ahead of time, since the pseudo-DMA code will sit
2079     		 * in an unconditional loop.
2080     		 */
2081     
2082     /* ++roman: I suggest, this should be
2083      *   #if def(REAL_DMA)
2084      * instead of leaving REAL_DMA out.
2085      */
2086     
2087     #if defined(REAL_DMA)
2088     //		if (!cmd->device->borken &&
2089     		if((transfersize =
2090     		    NCR5380_dma_xfer_len(instance,cmd,phase)) > SUN3_DMA_MINSIZE) {
2091     		    len = transfersize;
2092     		    cmd->SCp.phase = phase;
2093     
2094     		    if (NCR5380_transfer_dma(instance, &phase,
2095     			&len, (unsigned char **) &cmd->SCp.ptr)) {
2096     			/*
2097     			 * If the watchdog timer fires, all future
2098     			 * accesses to this device will use the
2099     			 * polled-IO. */ 
2100     			printk(KERN_NOTICE "scsi%d: switching target %d "
2101     			       "lun %d to slow handshake\n", HOSTNO,
2102     			       cmd->target, cmd->lun);
2103     			cmd->device->borken = 1;
2104     			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
2105     			    ICR_ASSERT_ATN);
2106     			sink = 1;
2107     			do_abort(instance);
2108     			cmd->result = DID_ERROR  << 16;
2109     			cmd->done(cmd);
2110     			/* XXX - need to source or sink data here, as appropriate */
2111     		    } else {
2112     #ifdef REAL_DMA
2113     			/* ++roman: When using real DMA,
2114     			 * information_transfer() should return after
2115     			 * starting DMA since it has nothing more to
2116     			 * do.
2117     			 */
2118     				    return;
2119     #else			
2120     			cmd->SCp.this_residual -= transfersize - len;
2121     #endif
2122     		    }
2123     		} else 
2124     #endif /* defined(REAL_DMA) */
2125     		  NCR5380_transfer_pio(instance, &phase, 
2126     		    (int *) &cmd->SCp.this_residual, (unsigned char **)
2127     		    &cmd->SCp.ptr);
2128     #ifdef REAL_DMA
2129     		/* if we had intended to dma that command clear it */
2130     		if(sun3_dma_setup_done == cmd)
2131     			sun3_dma_setup_done = NULL;
2132     #endif
2133     
2134     		break;
2135     	    case PHASE_MSGIN:
2136     		len = 1;
2137     		data = &tmp;
2138     		NCR5380_write(SELECT_ENABLE_REG, 0); 	/* disable reselects */
2139     		NCR5380_transfer_pio(instance, &phase, &len, &data);
2140     		cmd->SCp.Message = tmp;
2141     
2142     		switch (tmp) {
2143     		/*
2144     		 * Linking lets us reduce the time required to get the 
2145     		 * next command out to the device, hopefully this will
2146     		 * mean we don't waste another revolution due to the delays
2147     		 * required by ARBITRATION and another SELECTION.
2148     		 *
2149     		 * In the current implementation proposal, low level drivers
2150     		 * merely have to start the next command, pointed to by 
2151     		 * next_link, done() is called as with unlinked commands.
2152     		 */
2153     #ifdef LINKED
2154     		case LINKED_CMD_COMPLETE:
2155     		case LINKED_FLG_CMD_COMPLETE:
2156     		    /* Accept message by clearing ACK */
2157     		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2158     		    
2159     		    LNK_PRINTK("scsi%d: target %d lun %d linked command "
2160     			       "complete.\n", HOSTNO, cmd->target, cmd->lun);
2161     
2162     		    /* Enable reselect interrupts */
2163     		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2164     		    /*
2165     		     * Sanity check : A linked command should only terminate
2166     		     * with one of these messages if there are more linked
2167     		     * commands available.
2168     		     */
2169     
2170     		    if (!cmd->next_link) {
2171     			 printk(KERN_NOTICE "scsi%d: target %d lun %d "
2172     				"linked command complete, no next_link\n",
2173     				HOSTNO, cmd->target, cmd->lun);
2174     			    sink = 1;
2175     			    do_abort (instance);
2176     			    return;
2177     		    }
2178     
2179     		    initialize_SCp(cmd->next_link);
2180     		    /* The next command is still part of this process; copy it
2181     		     * and don't free it! */
2182     		    cmd->next_link->tag = cmd->tag;
2183     		    cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); 
2184     		    LNK_PRINTK("scsi%d: target %d lun %d linked request "
2185     			       "done, calling scsi_done().\n",
2186     			       HOSTNO, cmd->target, cmd->lun);
2187     #ifdef NCR5380_STATS
2188     		    collect_stats(hostdata, cmd);
2189     #endif
2190     		    cmd->scsi_done(cmd);
2191     		    cmd = hostdata->connected;
2192     		    break;
2193     #endif /* def LINKED */
2194     		case ABORT:
2195     		case COMMAND_COMPLETE: 
2196     		    /* Accept message by clearing ACK */
2197     		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2198     		    hostdata->connected = NULL;
2199     		    QU_PRINTK("scsi%d: command for target %d, lun %d "
2200     			      "completed\n", HOSTNO, cmd->target, cmd->lun);
2201     #ifdef SUPPORT_TAGS
2202     		    cmd_free_tag( cmd );
2203     		    if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
2204     			/* Turn a QUEUE FULL status into BUSY, I think the
2205     			 * mid level cannot handle QUEUE FULL :-( (The
2206     			 * command is retried after BUSY). Also update our
2207     			 * queue size to the number of currently issued
2208     			 * commands now.
2209     			 */
2210     			/* ++Andreas: the mid level code knows about
2211     			   QUEUE_FULL now. */
2212     			TAG_ALLOC *ta = &TagAlloc[cmd->target][cmd->lun];
2213     			TAG_PRINTK("scsi%d: target %d lun %d returned "
2214     				   "QUEUE_FULL after %d commands\n",
2215     				   HOSTNO, cmd->target, cmd->lun,
2216     				   ta->nr_allocated);
2217     			if (ta->queue_size > ta->nr_allocated)
2218     			    ta->nr_allocated = ta->queue_size;
2219     		    }
2220     #else
2221     		    hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
2222     #endif
2223     		    /* Enable reselect interrupts */
2224     		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2225     
2226     		    /* 
2227     		     * I'm not sure what the correct thing to do here is : 
2228     		     * 
2229     		     * If the command that just executed is NOT a request 
2230     		     * sense, the obvious thing to do is to set the result
2231     		     * code to the values of the stored parameters.
2232     		     * 
2233     		     * If it was a REQUEST SENSE command, we need some way to
2234     		     * differentiate between the failure code of the original
2235     		     * and the failure code of the REQUEST sense - the obvious
2236     		     * case is success, where we fall through and leave the
2237     		     * result code unchanged.
2238     		     * 
2239     		     * The non-obvious place is where the REQUEST SENSE failed
2240     		     */
2241     
2242     		    if (cmd->cmnd[0] != REQUEST_SENSE) 
2243     			cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); 
2244     		    else if (status_byte(cmd->SCp.Status) != GOOD)
2245     			cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2246     		    
2247     #ifdef AUTOSENSE
2248     		    if ((cmd->cmnd[0] != REQUEST_SENSE) && 
2249     			(status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2250     			ASEN_PRINTK("scsi%d: performing request sense\n",
2251     				    HOSTNO);
2252     			cmd->cmnd[0] = REQUEST_SENSE;
2253     			cmd->cmnd[1] &= 0xe0;
2254     			cmd->cmnd[2] = 0;
2255     			cmd->cmnd[3] = 0;
2256     			cmd->cmnd[4] = sizeof(cmd->sense_buffer);
2257     			cmd->cmnd[5] = 0;
2258     			cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
2259     
2260     			cmd->use_sg = 0;
2261     			/* this is initialized from initialize_SCp 
2262     			cmd->SCp.buffer = NULL;
2263     			cmd->SCp.buffers_residual = 0;
2264     			*/
2265     			cmd->request_buffer = (char *) cmd->sense_buffer;
2266     			cmd->request_bufflen = sizeof(cmd->sense_buffer);
2267     
2268     			save_flags(flags);
2269     			cli();
2270     			LIST(cmd,hostdata->issue_queue);
2271     			NEXT(cmd) = hostdata->issue_queue;
2272     		        hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2273     		        restore_flags(flags);
2274     			QU_PRINTK("scsi%d: REQUEST SENSE added to head of "
2275     				  "issue queue\n", H_NO(cmd));
2276     		   } else
2277     #endif /* def AUTOSENSE */
2278     		   {
2279     #ifdef NCR5380_STATS
2280     		       collect_stats(hostdata, cmd);
2281     #endif
2282     		       cmd->scsi_done(cmd);
2283     		    }
2284     
2285     		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2286     		    /* 
2287     		     * Restore phase bits to 0 so an interrupted selection, 
2288     		     * arbitration can resume.
2289     		     */
2290     		    NCR5380_write(TARGET_COMMAND_REG, 0);
2291     		    
2292     		    while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2293     			barrier();
2294     
2295     		    return;
2296     		case MESSAGE_REJECT:
2297     		    /* Accept message by clearing ACK */
2298     		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2299     		    /* Enable reselect interrupts */
2300     		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2301     		    switch (hostdata->last_message) {
2302     		    case HEAD_OF_QUEUE_TAG:
2303     		    case ORDERED_QUEUE_TAG:
2304     		    case SIMPLE_QUEUE_TAG:
2305     			/* The target obviously doesn't support tagged
2306     			 * queuing, even though it announced this ability in
2307     			 * its INQUIRY data ?!? (maybe only this LUN?) Ok,
2308     			 * clear 'tagged_supported' and lock the LUN, since
2309     			 * the command is treated as untagged further on.
2310     			 */
2311     			cmd->device->tagged_supported = 0;
2312     			hostdata->busy[cmd->target] |= (1 << cmd->lun);
2313     			cmd->tag = TAG_NONE;
2314     			TAG_PRINTK("scsi%d: target %d lun %d rejected "
2315     				   "QUEUE_TAG message; tagged queuing "
2316     				   "disabled\n",
2317     				   HOSTNO, cmd->target, cmd->lun);
2318     			break;
2319     		    }
2320     		    break;
2321     		case DISCONNECT:
2322     		    /* Accept message by clearing ACK */
2323     		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2324     		    save_flags(flags);
2325     		    cli();
2326     		    cmd->device->disconnect = 1;
2327     		    LIST(cmd,hostdata->disconnected_queue);
2328     		    NEXT(cmd) = hostdata->disconnected_queue;
2329     		    hostdata->connected = NULL;
2330     		    hostdata->disconnected_queue = cmd;
2331     		    restore_flags(flags);
2332     		    QU_PRINTK("scsi%d: command for target %d lun %d was "
2333     			      "moved from connected to the "
2334     			      "disconnected_queue\n", HOSTNO, 
2335     			      cmd->target, cmd->lun);
2336     		    /* 
2337     		     * Restore phase bits to 0 so an interrupted selection, 
2338     		     * arbitration can resume.
2339     		     */
2340     		    NCR5380_write(TARGET_COMMAND_REG, 0);
2341     
2342     		    /* Enable reselect interrupts */
2343     		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2344     		    /* Wait for bus free to avoid nasty timeouts */
2345     		    while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2346     		    	barrier();
2347     		    return;
2348     		/* 
2349     		 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2350     		 * operation, in violation of the SCSI spec so we can safely 
2351     		 * ignore SAVE/RESTORE pointers calls.
2352     		 *
2353     		 * Unfortunately, some disks violate the SCSI spec and 
2354     		 * don't issue the required SAVE_POINTERS message before
2355     		 * disconnecting, and we have to break spec to remain 
2356     		 * compatible.
2357     		 */
2358     		case SAVE_POINTERS:
2359     		case RESTORE_POINTERS:
2360     		    /* Accept message by clearing ACK */
2361     		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2362     		    /* Enable reselect interrupts */
2363     		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2364     		    break;
2365     		case EXTENDED_MESSAGE:
2366     /* 
2367      * Extended messages are sent in the following format :
2368      * Byte 	
2369      * 0		EXTENDED_MESSAGE == 1
2370      * 1		length (includes one byte for code, doesn't 
2371      *		include first two bytes)
2372      * 2 		code
2373      * 3..length+1	arguments
2374      *
2375      * Start the extended message buffer with the EXTENDED_MESSAGE
2376      * byte, since print_msg() wants the whole thing.  
2377      */
2378     		    extended_msg[0] = EXTENDED_MESSAGE;
2379     		    /* Accept first byte by clearing ACK */
2380     		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2381     
2382     		    EXT_PRINTK("scsi%d: receiving extended message\n", HOSTNO);
2383     
2384     		    len = 2;
2385     		    data = extended_msg + 1;
2386     		    phase = PHASE_MSGIN;
2387     		    NCR5380_transfer_pio(instance, &phase, &len, &data);
2388     		    EXT_PRINTK("scsi%d: length=%d, code=0x%02x\n", HOSTNO,
2389     			       (int)extended_msg[1], (int)extended_msg[2]);
2390     
2391     		    if (!len && extended_msg[1] <= 
2392     			(sizeof (extended_msg) - 1)) {
2393     			/* Accept third byte by clearing ACK */
2394     			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2395     			len = extended_msg[1] - 1;
2396     			data = extended_msg + 3;
2397     			phase = PHASE_MSGIN;
2398     
2399     			NCR5380_transfer_pio(instance, &phase, &len, &data);
2400     			EXT_PRINTK("scsi%d: message received, residual %d\n",
2401     				   HOSTNO, 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(KERN_NOTICE "scsi%d: error receiving "
2412     			       "extended message\n", HOSTNO);
2413     			tmp = 0;
2414     		    } else {
2415     			printk(KERN_NOTICE "scsi%d: extended message "
2416     			       "code %02x length %d is too long\n",
2417     			       HOSTNO, extended_msg[2], extended_msg[1]);
2418     			tmp = 0;
2419     		    }
2420     		/* Fall through to reject message */
2421     
2422     		/* 
2423       		 * If we get something weird that we aren't expecting, 
2424      		 * reject it.
2425     		 */
2426     		default:
2427     		    if (!tmp) {
2428     			printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
2429     			print_msg (extended_msg);
2430     			printk("\n");
2431     		    } else if (tmp != EXTENDED_MESSAGE)
2432     			printk(KERN_DEBUG "scsi%d: rejecting unknown "
2433     			       "message %02x from target %d, lun %d\n",
2434     			       HOSTNO, tmp, cmd->target, cmd->lun);
2435     		    else
2436     			printk(KERN_DEBUG "scsi%d: rejecting unknown "
2437     			       "extended message "
2438     			       "code %02x, length %d from target %d, lun %d\n",
2439     			       HOSTNO, extended_msg[1], extended_msg[0],
2440     			       cmd->target, cmd->lun);
2441        
2442     
2443     		    msgout = MESSAGE_REJECT;
2444     		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
2445     			ICR_ASSERT_ATN);
2446     		    break;
2447     		} /* switch (tmp) */
2448     		break;
2449     	    case PHASE_MSGOUT:
2450     		len = 1;
2451     		data = &msgout;
2452     		hostdata->last_message = msgout;
2453     		NCR5380_transfer_pio(instance, &phase, &len, &data);
2454     		if (msgout == ABORT) {
2455     #ifdef SUPPORT_TAGS
2456     		    cmd_free_tag( cmd );
2457     #else
2458     		    hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
2459     #endif
2460     		    hostdata->connected = NULL;
2461     		    cmd->result = DID_ERROR << 16;
2462     #ifdef NCR5380_STATS
2463     		    collect_stats(hostdata, cmd);
2464     #endif
2465     		    cmd->scsi_done(cmd);
2466     		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2467     		    return;
2468     		}
2469     		msgout = NOP;
2470     		break;
2471     	    case PHASE_CMDOUT:
2472     		len = cmd->cmd_len;
2473     		data = cmd->cmnd;
2474     		/* 
2475     		 * XXX for performance reasons, on machines with a 
2476     		 * PSEUDO-DMA architecture we should probably 
2477     		 * use the dma transfer function.  
2478     		 */
2479     		NCR5380_transfer_pio(instance, &phase, &len, 
2480     		    &data);
2481     		break;
2482     	    case PHASE_STATIN:
2483     		len = 1;
2484     		data = &tmp;
2485     		NCR5380_transfer_pio(instance, &phase, &len, &data);
2486     		cmd->SCp.Status = tmp;
2487     		break;
2488     	    default:
2489     		printk("scsi%d: unknown phase\n", HOSTNO);
2490     		NCR_PRINT(NDEBUG_ANY);
2491     	    } /* switch(phase) */
2492     	} /* if (tmp * SR_REQ) */ 
2493         } /* while (1) */
2494     }
2495     
2496     /*
2497      * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2498      *
2499      * Purpose : does reselection, initializing the instance->connected 
2500      *	field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q 
2501      *	nexus has been reestablished,
2502      *	
2503      * Inputs : instance - this instance of the NCR5380.
2504      *
2505      */
2506     
2507     /* it might eventually prove necessary to do a dma setup on
2508        reselection, but it doesn't seem to be needed now -- sam */
2509     
2510     static void NCR5380_reselect (struct Scsi_Host *instance)
2511     {
2512         SETUP_HOSTDATA(instance);
2513         unsigned char target_mask;
2514         unsigned char lun;
2515     #ifdef SUPPORT_TAGS
2516         unsigned char tag;
2517     #endif
2518         unsigned char msg[3];
2519         Scsi_Cmnd *tmp = NULL, *prev;
2520     /*    unsigned long flags; */
2521     
2522         /*
2523          * Disable arbitration, etc. since the host adapter obviously
2524          * lost, and tell an interrupted NCR5380_select() to restart.
2525          */
2526     
2527         NCR5380_write(MODE_REG, MR_BASE);
2528         hostdata->restart_select = 1;
2529     
2530         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2531     
2532         RSL_PRINTK("scsi%d: reselect\n", HOSTNO);
2533     
2534         /* 
2535          * At this point, we have detected that our SCSI ID is on the bus,
2536          * SEL is true and BSY was false for at least one bus settle delay
2537          * (400 ns).
2538          *
2539          * We must assert BSY ourselves, until the target drops the SEL
2540          * signal.
2541          */
2542     
2543         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2544         
2545         while (NCR5380_read(STATUS_REG) & SR_SEL);
2546         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2547     
2548         /*
2549          * Wait for target to go into MSGIN.
2550          */
2551     
2552         while (!(NCR5380_read(STATUS_REG) & SR_REQ));
2553     
2554     #if 1
2555         // acknowledge toggle to MSGIN
2556         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2557     
2558         // peek at the byte without really hitting the bus
2559         msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2560     #endif
2561     
2562         if (!msg[0] & 0x80) {
2563     	printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
2564     	print_msg(msg);
2565     	do_abort(instance);
2566     	return;
2567         }
2568         lun = (msg[0] & 0x07);
2569     
2570         /* 
2571          * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we 
2572          * just reestablished, and remove it from the disconnected queue.
2573          */
2574     
2575         for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; 
2576     	 tmp; prev = tmp, tmp = NEXT(tmp) ) {
2577     	if ((target_mask == (1 << tmp->target)) && (lun == tmp->lun)
2578     #ifdef SUPPORT_TAGS
2579     	    && (tag == tmp->tag) 
2580     #endif
2581     	    ) {
2582     	    if (prev) {
2583     		REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2584     		NEXT(prev) = NEXT(tmp);
2585     	    } else {
2586     		REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
2587     		hostdata->disconnected_queue = NEXT(tmp);
2588     	    }
2589     	    NEXT(tmp) = NULL;
2590     	    break;
2591     	}
2592         }
2593         
2594         if (!tmp) {
2595     	printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
2596     #ifdef SUPPORT_TAGS
2597     		"tag %d "
2598     #endif
2599     		"not in disconnected_queue.\n",
2600     		HOSTNO, target_mask, lun
2601     #ifdef SUPPORT_TAGS
2602     		, tag
2603     #endif
2604     		);
2605     	/* 
2606     	 * Since we have an established nexus that we can't do anything
2607     	 * with, we must abort it.  
2608     	 */
2609     	do_abort(instance);
2610     	return;
2611         }
2612     #if 1
2613         /* engage dma setup for the command we just saw */
2614         {
2615     	    void *d;
2616     		    unsigned long count;
2617     
2618     		if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
2619     			count = tmp->SCp.buffer->length;
2620     			d = tmp->SCp.buffer->address;
2621     		} else {
2622     			count = tmp->SCp.this_residual;
2623     			d = tmp->SCp.ptr;
2624     		}
2625     #ifdef REAL_DMA		
2626     		/* setup this command for dma if not already */
2627     		if((count > SUN3_DMA_MINSIZE) && (sun3_dma_setup_done
2628     						  != tmp))
2629     		{
2630     			sun3scsi_dma_setup(d, count,
2631     					   tmp->request.cmd);
2632     			sun3_dma_setup_done = tmp;
2633     		}
2634     #endif
2635         }
2636     #endif
2637     
2638         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2639         /* Accept message by clearing ACK */
2640         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2641     
2642     #ifdef SUPPORT_TAGS
2643         /* If the phase is still MSGIN, the target wants to send some more
2644          * messages. In case it supports tagged queuing, this is probably a
2645          * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2646          */
2647         tag = TAG_NONE;
2648         if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
2649     	/* Accept previous IDENTIFY message by clearing ACK */
2650     	NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE );
2651     	len = 2;
2652     	data = msg+1;
2653     	if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2654     	    msg[1] == SIMPLE_QUEUE_TAG)
2655     	    tag = msg[2];
2656     	TAG_PRINTK("scsi%d: target mask %02x, lun %d sent tag %d at "
2657     		   "reselection\n", HOSTNO, target_mask, lun, tag);
2658         }
2659     #endif
2660         
2661         hostdata->connected = tmp;
2662         RSL_PRINTK("scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
2663     	       HOSTNO, tmp->target, tmp->lun, tmp->tag);
2664     }
2665     
2666     
2667     /*
2668      * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2669      *
2670      * Purpose : abort a command
2671      *
2672      * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the 
2673      * 	host byte of the result field to, if zero DID_ABORTED is 
2674      *	used.
2675      *
2676      * Returns : 0 - success, -1 on failure.
2677      *
2678      * XXX - there is no way to abort the command that is currently 
2679      * 	 connected, you have to wait for it to complete.  If this is 
2680      *	 a problem, we could implement longjmp() / setjmp(), setjmp()
2681      * 	 called where the loop started in NCR5380_main().
2682      */
2683     
2684     #ifndef NCR5380_abort
2685     static
2686     #endif
2687     int NCR5380_abort (Scsi_Cmnd *cmd)
2688     {
2689         struct Scsi_Host *instance = cmd->host;
2690         SETUP_HOSTDATA(instance);
2691         Scsi_Cmnd *tmp, **prev;
2692         unsigned long flags;
2693     
2694         printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
2695         print_Scsi_Cmnd (cmd);
2696     
2697         NCR5380_print_status (instance);
2698     
2699         save_flags(flags);
2700         cli();
2701         
2702         ABRT_PRINTK("scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
2703     		NCR5380_read(BUS_AND_STATUS_REG),
2704     		NCR5380_read(STATUS_REG));
2705     
2706     #if 1
2707     /* 
2708      * Case 1 : If the command is the currently executing command, 
2709      * we'll set the aborted flag and return control so that 
2710      * information transfer routine can exit cleanly.
2711      */
2712     
2713         if (hostdata->connected == cmd) {
2714     
2715     	ABRT_PRINTK("scsi%d: aborting connected command\n", HOSTNO);
2716     /*
2717      * We should perform BSY checking, and make sure we haven't slipped
2718      * into BUS FREE.
2719      */
2720     
2721     /*	NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
2722     /* 
2723      * Since we can't change phases until we've completed the current 
2724      * handshake, we have to source or sink a byte of data if the current
2725      * phase is not MSGOUT.
2726      */
2727     
2728     /* 
2729      * Return control to the executing NCR drive so we can clear the
2730      * aborted flag and get back into our main loop.
2731      */ 
2732     
2733     	if (do_abort(instance) == 0) {
2734     	  hostdata->aborted = 1;
2735     	  hostdata->connected = NULL;
2736     	  cmd->result = DID_ABORT << 16;
2737     #ifdef SUPPORT_TAGS
2738     	  cmd_free_tag( cmd );
2739     #else
2740     	  hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
2741     #endif
2742     	  restore_flags(flags);
2743     	  cmd->scsi_done(cmd);
2744     	  return SCSI_ABORT_SUCCESS;
2745     	} else {
2746     /*	  restore_flags(flags); */
2747     	  printk("scsi%d: abort of connected command failed!\n", HOSTNO);
2748     	  return SCSI_ABORT_ERROR;
2749     	} 
2750        }
2751     #endif
2752     
2753     /* 
2754      * Case 2 : If the command hasn't been issued yet, we simply remove it 
2755      * 	    from the issue queue.
2756      */
2757         for (prev = (Scsi_Cmnd **) &(hostdata->issue_queue), 
2758     	tmp = (Scsi_Cmnd *) hostdata->issue_queue;
2759     	tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp) )
2760     	if (cmd == tmp) {
2761     	    REMOVE(5, *prev, tmp, NEXT(tmp));
2762     	    (*prev) = NEXT(tmp);
2763     	    NEXT(tmp) = NULL;
2764     	    tmp->result = DID_ABORT << 16;
2765     	    restore_flags(flags);
2766     	    ABRT_PRINTK("scsi%d: abort removed command from issue queue.\n",
2767     			HOSTNO);
2768     	    /* Tagged queuing note: no tag to free here, hasn't been assigned
2769     	     * yet... */
2770     	    tmp->scsi_done(tmp);
2771     	    return SCSI_ABORT_SUCCESS;
2772     	}
2773     
2774     /* 
2775      * Case 3 : If any commands are connected, we're going to fail the abort
2776      *	    and let the high level SCSI driver retry at a later time or 
2777      *	    issue a reset.
2778      *
2779      *	    Timeouts, and therefore aborted commands, will be highly unlikely
2780      *          and handling them cleanly in this situation would make the common
2781      *	    case of noresets less efficient, and would pollute our code.  So,
2782      *	    we fail.
2783      */
2784     
2785         if (hostdata->connected) {
2786     	restore_flags(flags);
2787     	ABRT_PRINTK("scsi%d: abort failed, command connected.\n", HOSTNO);
2788             return SCSI_ABORT_SNOOZE;
2789         }
2790     
2791     /*
2792      * Case 4: If the command is currently disconnected from the bus, and 
2793      * 	there are no connected commands, we reconnect the I_T_L or 
2794      *	I_T_L_Q nexus associated with it, go into message out, and send 
2795      *      an abort message.
2796      *
2797      * This case is especially ugly. In order to reestablish the nexus, we
2798      * need to call NCR5380_select().  The easiest way to implement this 
2799      * function was to abort if the bus was busy, and let the interrupt
2800      * handler triggered on the SEL for reselect take care of lost arbitrations
2801      * where necessary, meaning interrupts need to be enabled.
2802      *
2803      * When interrupts are enabled, the queues may change - so we 
2804      * can't remove it from the disconnected queue before selecting it
2805      * because that could cause a failure in hashing the nexus if that 
2806      * device reselected.
2807      * 
2808      * Since the queues may change, we can't use the pointers from when we
2809      * first locate it.
2810      *
2811      * So, we must first locate the command, and if NCR5380_select()
2812      * succeeds, then issue the abort, relocate the command and remove
2813      * it from the disconnected queue.
2814      */
2815     
2816         for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp;
2817     	 tmp = NEXT(tmp)) 
2818             if (cmd == tmp) {
2819                 restore_flags(flags);
2820     	    ABRT_PRINTK("scsi%d: aborting disconnected command.\n", HOSTNO);
2821       
2822                 if (NCR5380_select (instance, cmd, (int) cmd->tag)) 
2823     		return SCSI_ABORT_BUSY;
2824     
2825     	    ABRT_PRINTK("scsi%d: nexus reestablished.\n", HOSTNO);
2826     
2827     	    do_abort (instance);
2828     
2829     	    save_flags(flags);
2830     	    cli();
2831     	    for (prev = (Scsi_Cmnd **) &(hostdata->disconnected_queue), 
2832     		tmp = (Scsi_Cmnd *) hostdata->disconnected_queue;
2833     		tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp) )
2834     		    if (cmd == tmp) {
2835     		    REMOVE(5, *prev, tmp, NEXT(tmp));
2836     		    *prev = NEXT(tmp);
2837     		    NEXT(tmp) = NULL;
2838     		    tmp->result = DID_ABORT << 16;
2839     		    /* We must unlock the tag/LUN immediately here, since the
2840     		     * target goes to BUS FREE and doesn't send us another
2841     		     * message (COMMAND_COMPLETE or the like)
2842     		     */
2843     #ifdef SUPPORT_TAGS
2844     		    cmd_free_tag( tmp );
2845     #else
2846     		    hostdata->busy[cmd->target] &= ~(1 << cmd->lun);
2847     #endif
2848     		    restore_flags(flags);
2849     		    tmp->scsi_done(tmp);
2850     		    return SCSI_ABORT_SUCCESS;
2851     		}
2852     	}
2853     
2854     /*
2855      * Case 5 : If we reached this point, the command was not found in any of 
2856      *	    the queues.
2857      *
2858      * We probably reached this point because of an unlikely race condition
2859      * between the command completing successfully and the abortion code,
2860      * so we won't panic, but we will notify the user in case something really
2861      * broke.
2862      */
2863     
2864         restore_flags(flags);
2865         printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully\n"
2866                KERN_INFO "        before abortion\n", HOSTNO); 
2867     
2868         return SCSI_ABORT_NOT_RUNNING;
2869     }
2870     
2871     
2872     /* 
2873      * Function : int NCR5380_reset (Scsi_Cmnd *cmd, unsigned int reset_flags)
2874      * 
2875      * Purpose : reset the SCSI bus.
2876      *
2877      * Returns : SCSI_RESET_WAKEUP
2878      *
2879      */ 
2880     
2881     int NCR5380_reset( Scsi_Cmnd *cmd, unsigned int reset_flags)
2882     {
2883         SETUP_HOSTDATA(cmd->host);
2884         int           i;
2885         unsigned long flags;
2886     #if 1
2887         Scsi_Cmnd *connected, *disconnected_queue;
2888     #endif
2889     
2890     
2891         NCR5380_print_status (cmd->host);
2892     
2893         /* get in phase */
2894         NCR5380_write( TARGET_COMMAND_REG,
2895     		   PHASE_SR_TO_TCR( NCR5380_read(STATUS_REG) ));
2896         /* assert RST */
2897         NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST );
2898         udelay (40);
2899         /* reset NCR registers */
2900         NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE );
2901         NCR5380_write( MODE_REG, MR_BASE );
2902         NCR5380_write( TARGET_COMMAND_REG, 0 );
2903         NCR5380_write( SELECT_ENABLE_REG, 0 );
2904         /* ++roman: reset interrupt condition! otherwise no interrupts don't get
2905          * through anymore ... */
2906         (void)NCR5380_read( RESET_PARITY_INTERRUPT_REG );
2907     
2908     #if 1 /* XXX Should now be done by midlevel code, but it's broken XXX */
2909           /* XXX see below                                            XXX */
2910     
2911         /* MSch: old-style reset: actually abort all command processing here */
2912     
2913         /* After the reset, there are no more connected or disconnected commands
2914          * and no busy units; to avoid problems with re-inserting the commands
2915          * into the issue_queue (via scsi_done()), the aborted commands are
2916          * remembered in local variables first.
2917          */
2918         save_flags(flags);
2919         cli();
2920         connected = (Scsi_Cmnd *)hostdata->connected;
2921         hostdata->connected = NULL;
2922         disconnected_queue = (Scsi_Cmnd *)hostdata->disconnected_queue;
2923         hostdata->disconnected_queue = NULL;
2924     #ifdef SUPPORT_TAGS
2925         free_all_tags();
2926     #endif
2927         for( i = 0; i < 8; ++i )
2928     	hostdata->busy[i] = 0;
2929     #ifdef REAL_DMA
2930         hostdata->dma_len = 0;
2931     #endif
2932         restore_flags(flags);
2933     
2934         /* In order to tell the mid-level code which commands were aborted, 
2935          * set the command status to DID_RESET and call scsi_done() !!!
2936          * This ultimately aborts processing of these commands in the mid-level.
2937          */
2938     
2939         if ((cmd = connected)) {
2940     	ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2941     	cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2942     	cmd->scsi_done( cmd );
2943         }
2944     
2945         for (i = 0; (cmd = disconnected_queue); ++i) {
2946     	disconnected_queue = NEXT(cmd);
2947     	NEXT(cmd) = NULL;
2948     	cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2949     	cmd->scsi_done( cmd );
2950         }
2951         if (i > 0)
2952     	ABRT_PRINTK("scsi: reset aborted %d disconnected command(s)\n", i);
2953     
2954     
2955         /* since all commands have been explicitly terminated, we need to tell
2956          * the midlevel code that the reset was SUCCESSFUL, and there is no 
2957          * need to 'wake up' the commands by a request_sense
2958          */
2959         return SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET;
2960     #else /* 1 */
2961     
2962         /* MSch: new-style reset handling: let the mid-level do what it can */
2963     
2964         /* ++guenther: MID-LEVEL IS STILL BROKEN.
2965          * Mid-level is supposed to requeue all commands that were active on the
2966          * various low-level queues. In fact it does this, but that's not enough
2967          * because all these commands are subject to timeout. And if a timeout
2968          * happens for any removed command, *_abort() is called but all queues
2969          * are now empty. Abort then gives up the falcon lock, which is fatal,
2970          * since the mid-level will queue more commands and must have the lock
2971          * (it's all happening inside timer interrupt handler!!).
2972          * Even worse, abort will return NOT_RUNNING for all those commands not
2973          * on any queue, so they won't be retried ...
2974          *
2975          * Conclusion: either scsi.c disables timeout for all resetted commands
2976          * immediately, or we loose!  As of linux-2.0.20 it doesn't.
2977          */
2978     
2979         /* After the reset, there are no more connected or disconnected commands
2980          * and no busy units; so clear the low-level status here to avoid 
2981          * conflicts when the mid-level code tries to wake up the affected 
2982          * commands!
2983          */
2984     
2985         if (hostdata->issue_queue)
2986     	ABRT_PRINTK("scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
2987         if (hostdata->connected) 
2988     	ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2989         if (hostdata->disconnected_queue)
2990     	ABRT_PRINTK("scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));
2991     
2992         save_flags(flags);
2993         cli();
2994         hostdata->issue_queue = NULL;
2995         hostdata->connected = NULL;
2996         hostdata->disconnected_queue = NULL;
2997     #ifdef SUPPORT_TAGS
2998         free_all_tags();
2999     #endif
3000         for( i = 0; i < 8; ++i )
3001     	hostdata->busy[i] = 0;
3002     #ifdef REAL_DMA
3003         hostdata->dma_len = 0;
3004     #endif
3005         restore_flags(flags);
3006     
3007         /* we did no complete reset of all commands, so a wakeup is required */
3008         return SCSI_RESET_WAKEUP | SCSI_RESET_BUS_RESET;
3009     #endif /* 1 */
3010     }
3011     
3012     /* Local Variables: */
3013     /* tab-width: 8     */
3014     /* End:             */
3015