m68k: Atari SCSI workqueue updates
[linux-2.6.git] / drivers / scsi / atari_NCR5380.c
1 /*
2  * NCR 5380 generic driver routines.  These should make it *trivial*
3  *      to implement 5380 SCSI drivers under Linux with a non-trantor
4  *      architecture.
5  *
6  *      Note that these routines also work with NR53c400 family chips.
7  *
8  * Copyright 1993, Drew Eckhardt
9  *      Visionary Computing
10  *      (Unix and Linux consulting and custom programming)
11  *      drew@colorado.edu
12  *      +1 (303) 666-5836
13  *
14  * DISTRIBUTION RELEASE 6.
15  *
16  * For more information, please consult
17  *
18  * NCR 5380 Family
19  * SCSI Protocol Controller
20  * Databook
21  *
22  * NCR Microelectronics
23  * 1635 Aeroplaza Drive
24  * Colorado Springs, CO 80916
25  * 1+ (719) 578-3400
26  * 1+ (800) 334-5454
27  */
28
29 /*
30  * ++roman: To port the 5380 driver to the Atari, I had to do some changes in
31  * this file, too:
32  *
33  *  - Some of the debug statements were incorrect (undefined variables and the
34  *    like). I fixed that.
35  *
36  *  - In information_transfer(), I think a #ifdef was wrong. Looking at the
37  *    possible DMA transfer size should also happen for REAL_DMA. I added this
38  *    in the #if statement.
39  *
40  *  - When using real DMA, information_transfer() should return in a DATAOUT
41  *    phase after starting the DMA. It has nothing more to do.
42  *
43  *  - The interrupt service routine should run main after end of DMA, too (not
44  *    only after RESELECTION interrupts). Additionally, it should _not_ test
45  *    for more interrupts after running main, since a DMA process may have
46  *    been started and interrupts are turned on now. The new int could happen
47  *    inside the execution of NCR5380_intr(), leading to recursive
48  *    calls.
49  *
50  *  - I've added a function merge_contiguous_buffers() that tries to
51  *    merge scatter-gather buffers that are located at contiguous
52  *    physical addresses and can be processed with the same DMA setup.
53  *    Since most scatter-gather operations work on a page (4K) of
54  *    4 buffers (1K), in more than 90% of all cases three interrupts and
55  *    DMA setup actions are saved.
56  *
57  * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
58  *    and USLEEP, because these were messing up readability and will never be
59  *    needed for Atari SCSI.
60  *
61  * - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
62  *   stuff), and 'main' is executed in a bottom half if awoken by an
63  *   interrupt.
64  *
65  * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
66  *   constructs. In my eyes, this made the source rather unreadable, so I
67  *   finally replaced that by the *_PRINTK() macros.
68  *
69  */
70
71 /*
72  * Further development / testing that should be done :
73  * 1.  Test linked command handling code after Eric is ready with
74  *     the high level code.
75  */
76 #include <scsi/scsi_dbg.h>
77 #include <scsi/scsi_transport_spi.h>
78
79 #if (NDEBUG & NDEBUG_LISTS)
80 #define LIST(x, y)                                              \
81         do {                                                    \
82                 printk("LINE:%d   Adding %p to %p\n",           \
83                        __LINE__, (void*)(x), (void*)(y));       \
84                 if ((x) == (y))                                 \
85                         udelay(5);                              \
86         } while (0)
87 #define REMOVE(w, x, y, z)                                      \
88         do {                                                    \
89                 printk("LINE:%d   Removing: %p->%p  %p->%p \n", \
90                        __LINE__, (void*)(w), (void*)(x),        \
91                        (void*)(y), (void*)(z));                 \
92                 if ((x) == (y))                                 \
93                         udelay(5);                              \
94         } while (0)
95 #else
96 #define LIST(x,y)
97 #define REMOVE(w,x,y,z)
98 #endif
99
100 #ifndef notyet
101 #undef LINKED
102 #endif
103
104 /*
105  * Design
106  * Issues :
107  *
108  * The other Linux SCSI drivers were written when Linux was Intel PC-only,
109  * and specifically for each board rather than each chip.  This makes their
110  * adaptation to platforms like the Mac (Some of which use NCR5380's)
111  * more difficult than it has to be.
112  *
113  * Also, many of the SCSI drivers were written before the command queuing
114  * routines were implemented, meaning their implementations of queued
115  * commands were hacked on rather than designed in from the start.
116  *
117  * When I designed the Linux SCSI drivers I figured that
118  * while having two different SCSI boards in a system might be useful
119  * for debugging things, two of the same type wouldn't be used.
120  * Well, I was wrong and a number of users have mailed me about running
121  * multiple high-performance SCSI boards in a server.
122  *
123  * Finally, when I get questions from users, I have no idea what
124  * revision of my driver they are running.
125  *
126  * This driver attempts to address these problems :
127  * This is a generic 5380 driver.  To use it on a different platform,
128  * one simply writes appropriate system specific macros (ie, data
129  * transfer - some PC's will use the I/O bus, 68K's must use
130  * memory mapped) and drops this file in their 'C' wrapper.
131  *
132  * As far as command queueing, two queues are maintained for
133  * each 5380 in the system - commands that haven't been issued yet,
134  * and commands that are currently executing.  This means that an
135  * unlimited number of commands may be queued, letting
136  * more commands propagate from the higher driver levels giving higher
137  * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
138  * allowing multiple commands to propagate all the way to a SCSI-II device
139  * while a command is already executing.
140  *
141  * To solve the multiple-boards-in-the-same-system problem,
142  * there is a separate instance structure for each instance
143  * of a 5380 in the system.  So, multiple NCR5380 drivers will
144  * be able to coexist with appropriate changes to the high level
145  * SCSI code.
146  *
147  * A NCR5380_PUBLIC_REVISION macro is provided, with the release
148  * number (updated for each public release) printed by the
149  * NCR5380_print_options command, which should be called from the
150  * wrapper detect function, so that I know what release of the driver
151  * users are using.
152  *
153  * Issues specific to the NCR5380 :
154  *
155  * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
156  * piece of hardware that requires you to sit in a loop polling for
157  * the REQ signal as long as you are connected.  Some devices are
158  * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
159  * while doing long seek operations.
160  *
161  * The workaround for this is to keep track of devices that have
162  * disconnected.  If the device hasn't disconnected, for commands that
163  * should disconnect, we do something like
164  *
165  * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
166  *
167  * Some tweaking of N and M needs to be done.  An algorithm based
168  * on "time to data" would give the best results as long as short time
169  * to datas (ie, on the same track) were considered, however these
170  * broken devices are the exception rather than the rule and I'd rather
171  * spend my time optimizing for the normal case.
172  *
173  * Architecture :
174  *
175  * At the heart of the design is a coroutine, NCR5380_main,
176  * which is started when not running by the interrupt handler,
177  * timer, and queue command function.  It attempts to establish
178  * I_T_L or I_T_L_Q nexuses by removing the commands from the
179  * issue queue and calling NCR5380_select() if a nexus
180  * is not established.
181  *
182  * Once a nexus is established, the NCR5380_information_transfer()
183  * phase goes through the various phases as instructed by the target.
184  * if the target goes into MSG IN and sends a DISCONNECT message,
185  * the command structure is placed into the per instance disconnected
186  * queue, and NCR5380_main tries to find more work.  If USLEEP
187  * was defined, and the target is idle for too long, the system
188  * will try to sleep.
189  *
190  * If a command has disconnected, eventually an interrupt will trigger,
191  * calling NCR5380_intr()  which will in turn call NCR5380_reselect
192  * to reestablish a nexus.  This will run main if necessary.
193  *
194  * On command termination, the done function will be called as
195  * appropriate.
196  *
197  * SCSI pointers are maintained in the SCp field of SCSI command
198  * structures, being initialized after the command is connected
199  * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
200  * Note that in violation of the standard, an implicit SAVE POINTERS operation
201  * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
202  */
203
204 /*
205  * Using this file :
206  * This file a skeleton Linux SCSI driver for the NCR 5380 series
207  * of chips.  To use it, you write an architecture specific functions
208  * and macros and include this file in your driver.
209  *
210  * These macros control options :
211  * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
212  *      for commands that return with a CHECK CONDITION status.
213  *
214  * LINKED - if defined, linked commands are supported.
215  *
216  * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
217  *
218  * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
219  *
220  * These macros MUST be defined :
221  *
222  * NCR5380_read(register)  - read from the specified register
223  *
224  * NCR5380_write(register, value) - write to the specific register
225  *
226  * Either real DMA *or* pseudo DMA may be implemented
227  * REAL functions :
228  * NCR5380_REAL_DMA should be defined if real DMA is to be used.
229  * Note that the DMA setup functions should return the number of bytes
230  *      that they were able to program the controller for.
231  *
232  * Also note that generic i386/PC versions of these macros are
233  *      available as NCR5380_i386_dma_write_setup,
234  *      NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
235  *
236  * NCR5380_dma_write_setup(instance, src, count) - initialize
237  * NCR5380_dma_read_setup(instance, dst, count) - initialize
238  * NCR5380_dma_residual(instance); - residual count
239  *
240  * PSEUDO functions :
241  * NCR5380_pwrite(instance, src, count)
242  * NCR5380_pread(instance, dst, count);
243  *
244  * If nothing specific to this implementation needs doing (ie, with external
245  * hardware), you must also define
246  *
247  * NCR5380_queue_command
248  * NCR5380_reset
249  * NCR5380_abort
250  * NCR5380_proc_info
251  *
252  * to be the global entry points into the specific driver, ie
253  * #define NCR5380_queue_command t128_queue_command.
254  *
255  * If this is not done, the routines will be defined as static functions
256  * with the NCR5380* names and the user must provide a globally
257  * accessible wrapper function.
258  *
259  * The generic driver is initialized by calling NCR5380_init(instance),
260  * after setting the appropriate host specific fields and ID.  If the
261  * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
262  * possible) function may be used.  Before the specific driver initialization
263  * code finishes, NCR5380_print_options should be called.
264  */
265
266 static struct Scsi_Host *first_instance = NULL;
267 static struct scsi_host_template *the_template = NULL;
268
269 /* Macros ease life... :-) */
270 #define SETUP_HOSTDATA(in)                              \
271     struct NCR5380_hostdata *hostdata =                 \
272         (struct NCR5380_hostdata *)(in)->hostdata
273 #define HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)
274
275 #define NEXT(cmd)               ((Scsi_Cmnd *)(cmd)->host_scribble)
276 #define SET_NEXT(cmd,next)      ((cmd)->host_scribble = (void *)(next))
277 #define NEXTADDR(cmd)           ((Scsi_Cmnd **)&(cmd)->host_scribble)
278
279 #define HOSTNO          instance->host_no
280 #define H_NO(cmd)       (cmd)->device->host->host_no
281
282 #ifdef SUPPORT_TAGS
283
284 /*
285  * Functions for handling tagged queuing
286  * =====================================
287  *
288  * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
289  *
290  * Using consecutive numbers for the tags is no good idea in my eyes. There
291  * could be wrong re-usings if the counter (8 bit!) wraps and some early
292  * command has been preempted for a long time. My solution: a bitfield for
293  * remembering used tags.
294  *
295  * There's also the problem that each target has a certain queue size, but we
296  * cannot know it in advance :-( We just see a QUEUE_FULL status being
297  * returned. So, in this case, the driver internal queue size assumption is
298  * reduced to the number of active tags if QUEUE_FULL is returned by the
299  * target. The command is returned to the mid-level, but with status changed
300  * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
301  * correctly.
302  *
303  * We're also not allowed running tagged commands as long as an untagged
304  * command is active. And REQUEST SENSE commands after a contingent allegiance
305  * condition _must_ be untagged. To keep track whether an untagged command has
306  * been issued, the host->busy array is still employed, as it is without
307  * support for tagged queuing.
308  *
309  * One could suspect that there are possible race conditions between
310  * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
311  * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
312  * which already guaranteed to be running at most once. It is also the only
313  * place where tags/LUNs are allocated. So no other allocation can slip
314  * between that pair, there could only happen a reselection, which can free a
315  * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
316  * important: the tag bit must be cleared before 'nr_allocated' is decreased.
317  */
318
319 /* -1 for TAG_NONE is not possible with unsigned char cmd->tag */
320 #undef TAG_NONE
321 #define TAG_NONE 0xff
322
323 typedef struct {
324         DECLARE_BITMAP(allocated, MAX_TAGS);
325         int nr_allocated;
326         int queue_size;
327 } TAG_ALLOC;
328
329 static TAG_ALLOC TagAlloc[8][8];        /* 8 targets and 8 LUNs */
330
331
332 static void __init init_tags(void)
333 {
334         int target, lun;
335         TAG_ALLOC *ta;
336
337         if (!setup_use_tagged_queuing)
338                 return;
339
340         for (target = 0; target < 8; ++target) {
341                 for (lun = 0; lun < 8; ++lun) {
342                         ta = &TagAlloc[target][lun];
343                         bitmap_zero(ta->allocated, MAX_TAGS);
344                         ta->nr_allocated = 0;
345                         /* At the beginning, assume the maximum queue size we could
346                          * support (MAX_TAGS). This value will be decreased if the target
347                          * returns QUEUE_FULL status.
348                          */
349                         ta->queue_size = MAX_TAGS;
350                 }
351         }
352 }
353
354
355 /* Check if we can issue a command to this LUN: First see if the LUN is marked
356  * busy by an untagged command. If the command should use tagged queuing, also
357  * check that there is a free tag and the target's queue won't overflow. This
358  * function should be called with interrupts disabled to avoid race
359  * conditions.
360  */
361
362 static int is_lun_busy(Scsi_Cmnd *cmd, int should_be_tagged)
363 {
364         SETUP_HOSTDATA(cmd->device->host);
365
366         if (hostdata->busy[cmd->device->id] & (1 << cmd->device->lun))
367                 return 1;
368         if (!should_be_tagged ||
369             !setup_use_tagged_queuing || !cmd->device->tagged_supported)
370                 return 0;
371         if (TagAlloc[cmd->device->id][cmd->device->lun].nr_allocated >=
372             TagAlloc[cmd->device->id][cmd->device->lun].queue_size) {
373                 TAG_PRINTK("scsi%d: target %d lun %d: no free tags\n",
374                            H_NO(cmd), cmd->device->id, cmd->device->lun);
375                 return 1;
376         }
377         return 0;
378 }
379
380
381 /* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
382  * must be called before!), or reserve the LUN in 'busy' if the command is
383  * untagged.
384  */
385
386 static void cmd_get_tag(Scsi_Cmnd *cmd, int should_be_tagged)
387 {
388         SETUP_HOSTDATA(cmd->device->host);
389
390         /* If we or the target don't support tagged queuing, allocate the LUN for
391          * an untagged command.
392          */
393         if (!should_be_tagged ||
394             !setup_use_tagged_queuing || !cmd->device->tagged_supported) {
395                 cmd->tag = TAG_NONE;
396                 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
397                 TAG_PRINTK("scsi%d: target %d lun %d now allocated by untagged "
398                            "command\n", H_NO(cmd), cmd->device->id, cmd->device->lun);
399         } else {
400                 TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
401
402                 cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
403                 set_bit(cmd->tag, ta->allocated);
404                 ta->nr_allocated++;
405                 TAG_PRINTK("scsi%d: using tag %d for target %d lun %d "
406                            "(now %d tags in use)\n",
407                            H_NO(cmd), cmd->tag, cmd->device->id,
408                            cmd->device->lun, ta->nr_allocated);
409         }
410 }
411
412
413 /* Mark the tag of command 'cmd' as free, or in case of an untagged command,
414  * unlock the LUN.
415  */
416
417 static void cmd_free_tag(Scsi_Cmnd *cmd)
418 {
419         SETUP_HOSTDATA(cmd->device->host);
420
421         if (cmd->tag == TAG_NONE) {
422                 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
423                 TAG_PRINTK("scsi%d: target %d lun %d untagged cmd finished\n",
424                            H_NO(cmd), cmd->device->id, cmd->device->lun);
425         } else if (cmd->tag >= MAX_TAGS) {
426                 printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
427                        H_NO(cmd), cmd->tag);
428         } else {
429                 TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
430                 clear_bit(cmd->tag, ta->allocated);
431                 ta->nr_allocated--;
432                 TAG_PRINTK("scsi%d: freed tag %d for target %d lun %d\n",
433                            H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun);
434         }
435 }
436
437
438 static void free_all_tags(void)
439 {
440         int target, lun;
441         TAG_ALLOC *ta;
442
443         if (!setup_use_tagged_queuing)
444                 return;
445
446         for (target = 0; target < 8; ++target) {
447                 for (lun = 0; lun < 8; ++lun) {
448                         ta = &TagAlloc[target][lun];
449                         bitmap_zero(ta->allocated, MAX_TAGS);
450                         ta->nr_allocated = 0;
451                 }
452         }
453 }
454
455 #endif /* SUPPORT_TAGS */
456
457
458 /*
459  * Function: void merge_contiguous_buffers( Scsi_Cmnd *cmd )
460  *
461  * Purpose: Try to merge several scatter-gather requests into one DMA
462  *    transfer. This is possible if the scatter buffers lie on
463  *    physical contiguous addresses.
464  *
465  * Parameters: Scsi_Cmnd *cmd
466  *    The command to work on. The first scatter buffer's data are
467  *    assumed to be already transfered into ptr/this_residual.
468  */
469
470 static void merge_contiguous_buffers(Scsi_Cmnd *cmd)
471 {
472         unsigned long endaddr;
473 #if (NDEBUG & NDEBUG_MERGING)
474         unsigned long oldlen = cmd->SCp.this_residual;
475         int cnt = 1;
476 #endif
477
478         for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
479              cmd->SCp.buffers_residual &&
480              virt_to_phys(page_address(cmd->SCp.buffer[1].page) +
481                           cmd->SCp.buffer[1].offset) == endaddr;) {
482                 MER_PRINTK("VTOP(%p) == %08lx -> merging\n",
483                            page_address(cmd->SCp.buffer[1].page), endaddr);
484 #if (NDEBUG & NDEBUG_MERGING)
485                 ++cnt;
486 #endif
487                 ++cmd->SCp.buffer;
488                 --cmd->SCp.buffers_residual;
489                 cmd->SCp.this_residual += cmd->SCp.buffer->length;
490                 endaddr += cmd->SCp.buffer->length;
491         }
492 #if (NDEBUG & NDEBUG_MERGING)
493         if (oldlen != cmd->SCp.this_residual)
494                 MER_PRINTK("merged %d buffers from %p, new length %08x\n",
495                            cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
496 #endif
497 }
498
499 /*
500  * Function : void initialize_SCp(Scsi_Cmnd *cmd)
501  *
502  * Purpose : initialize the saved data pointers for cmd to point to the
503  *      start of the buffer.
504  *
505  * Inputs : cmd - Scsi_Cmnd structure to have pointers reset.
506  */
507
508 static inline void initialize_SCp(Scsi_Cmnd *cmd)
509 {
510         /*
511          * Initialize the Scsi Pointer field so that all of the commands in the
512          * various queues are valid.
513          */
514
515         if (cmd->use_sg) {
516                 cmd->SCp.buffer = (struct scatterlist *)cmd->request_buffer;
517                 cmd->SCp.buffers_residual = cmd->use_sg - 1;
518                 cmd->SCp.ptr = (char *)page_address(cmd->SCp.buffer->page) +
519                                cmd->SCp.buffer->offset;
520                 cmd->SCp.this_residual = cmd->SCp.buffer->length;
521                 /* ++roman: Try to merge some scatter-buffers if they are at
522                  * contiguous physical addresses.
523                  */
524                 merge_contiguous_buffers(cmd);
525         } else {
526                 cmd->SCp.buffer = NULL;
527                 cmd->SCp.buffers_residual = 0;
528                 cmd->SCp.ptr = (char *)cmd->request_buffer;
529                 cmd->SCp.this_residual = cmd->request_bufflen;
530         }
531 }
532
533 #include <linux/delay.h>
534
535 #if NDEBUG
536 static struct {
537         unsigned char mask;
538         const char *name;
539 } signals[] = {
540         { SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" },
541         { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD,  "CD" }, { SR_IO, "IO" },
542         { SR_SEL, "SEL" }, {0, NULL}
543 }, basrs[] = {
544         {BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}
545 }, icrs[] = {
546         {ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
547         {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"},
548         {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"},
549         {0, NULL}
550 }, mrs[] = {
551         {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"},
552         {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR,
553         "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
554         {MR_MONITOR_BSY, "MODE MONITOR BSY"},
555         {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"},
556         {0, NULL}
557 };
558
559 /*
560  * Function : void NCR5380_print(struct Scsi_Host *instance)
561  *
562  * Purpose : print the SCSI bus signals for debugging purposes
563  *
564  * Input : instance - which NCR5380
565  */
566
567 static void NCR5380_print(struct Scsi_Host *instance)
568 {
569         unsigned char status, data, basr, mr, icr, i;
570         unsigned long flags;
571
572         local_irq_save(flags);
573         data = NCR5380_read(CURRENT_SCSI_DATA_REG);
574         status = NCR5380_read(STATUS_REG);
575         mr = NCR5380_read(MODE_REG);
576         icr = NCR5380_read(INITIATOR_COMMAND_REG);
577         basr = NCR5380_read(BUS_AND_STATUS_REG);
578         local_irq_restore(flags);
579         printk("STATUS_REG: %02x ", status);
580         for (i = 0; signals[i].mask; ++i)
581                 if (status & signals[i].mask)
582                         printk(",%s", signals[i].name);
583         printk("\nBASR: %02x ", basr);
584         for (i = 0; basrs[i].mask; ++i)
585                 if (basr & basrs[i].mask)
586                         printk(",%s", basrs[i].name);
587         printk("\nICR: %02x ", icr);
588         for (i = 0; icrs[i].mask; ++i)
589                 if (icr & icrs[i].mask)
590                         printk(",%s", icrs[i].name);
591         printk("\nMODE: %02x ", mr);
592         for (i = 0; mrs[i].mask; ++i)
593                 if (mr & mrs[i].mask)
594                         printk(",%s", mrs[i].name);
595         printk("\n");
596 }
597
598 static struct {
599         unsigned char value;
600         const char *name;
601 } phases[] = {
602         {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
603         {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
604         {PHASE_UNKNOWN, "UNKNOWN"}
605 };
606
607 /*
608  * Function : void NCR5380_print_phase(struct Scsi_Host *instance)
609  *
610  * Purpose : print the current SCSI phase for debugging purposes
611  *
612  * Input : instance - which NCR5380
613  */
614
615 static void NCR5380_print_phase(struct Scsi_Host *instance)
616 {
617         unsigned char status;
618         int i;
619
620         status = NCR5380_read(STATUS_REG);
621         if (!(status & SR_REQ))
622                 printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
623         else {
624                 for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
625                      (phases[i].value != (status & PHASE_MASK)); ++i)
626                         ;
627                 printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
628         }
629 }
630
631 #else /* !NDEBUG */
632
633 /* dummies... */
634 static inline void NCR5380_print(struct Scsi_Host *instance)
635 {
636 };
637 static inline void NCR5380_print_phase(struct Scsi_Host *instance)
638 {
639 };
640
641 #endif
642
643 /*
644  * ++roman: New scheme of calling NCR5380_main()
645  *
646  * If we're not in an interrupt, we can call our main directly, it cannot be
647  * already running. Else, we queue it on a task queue, if not 'main_running'
648  * tells us that a lower level is already executing it. This way,
649  * 'main_running' needs not be protected in a special way.
650  *
651  * queue_main() is a utility function for putting our main onto the task
652  * queue, if main_running is false. It should be called only from a
653  * interrupt or bottom half.
654  */
655
656 #include <linux/workqueue.h>
657 #include <linux/interrupt.h>
658
659 static volatile int main_running;
660 static DECLARE_WORK(NCR5380_tqueue, NCR5380_main);
661
662 static inline void queue_main(void)
663 {
664         if (!main_running) {
665                 /* If in interrupt and NCR5380_main() not already running,
666                    queue it on the 'immediate' task queue, to be processed
667                    immediately after the current interrupt processing has
668                    finished. */
669                 schedule_work(&NCR5380_tqueue);
670         }
671         /* else: nothing to do: the running NCR5380_main() will pick up
672            any newly queued command. */
673 }
674
675
676 static inline void NCR5380_all_init(void)
677 {
678         static int done = 0;
679         if (!done) {
680                 INI_PRINTK("scsi : NCR5380_all_init()\n");
681                 done = 1;
682         }
683 }
684
685
686 /*
687  * Function : void NCR58380_print_options (struct Scsi_Host *instance)
688  *
689  * Purpose : called by probe code indicating the NCR5380 driver
690  *           options that were selected.
691  *
692  * Inputs : instance, pointer to this instance.  Unused.
693  */
694
695 static void __init NCR5380_print_options(struct Scsi_Host *instance)
696 {
697         printk(" generic options"
698 #ifdef AUTOSENSE
699                " AUTOSENSE"
700 #endif
701 #ifdef REAL_DMA
702                " REAL DMA"
703 #endif
704 #ifdef PARITY
705                " PARITY"
706 #endif
707 #ifdef SUPPORT_TAGS
708                " SCSI-2 TAGGED QUEUING"
709 #endif
710                );
711         printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
712 }
713
714 /*
715  * Function : void NCR5380_print_status (struct Scsi_Host *instance)
716  *
717  * Purpose : print commands in the various queues, called from
718  *      NCR5380_abort and NCR5380_debug to aid debugging.
719  *
720  * Inputs : instance, pointer to this instance.
721  */
722
723 static void NCR5380_print_status(struct Scsi_Host *instance)
724 {
725         char *pr_bfr;
726         char *start;
727         int len;
728
729         NCR_PRINT(NDEBUG_ANY);
730         NCR_PRINT_PHASE(NDEBUG_ANY);
731
732         pr_bfr = (char *)__get_free_page(GFP_ATOMIC);
733         if (!pr_bfr) {
734                 printk("NCR5380_print_status: no memory for print buffer\n");
735                 return;
736         }
737         len = NCR5380_proc_info(instance, pr_bfr, &start, 0, PAGE_SIZE, 0);
738         pr_bfr[len] = 0;
739         printk("\n%s\n", pr_bfr);
740         free_page((unsigned long)pr_bfr);
741 }
742
743
744 /******************************************/
745 /*
746  * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
747  *
748  * *buffer: I/O buffer
749  * **start: if inout == FALSE pointer into buffer where user read should start
750  * offset: current offset
751  * length: length of buffer
752  * hostno: Scsi_Host host_no
753  * inout: TRUE - user is writing; FALSE - user is reading
754  *
755  * Return the number of bytes read from or written
756 */
757
758 #undef SPRINTF
759 #define SPRINTF(fmt,args...)                                                    \
760         do {                                                                    \
761                 if (pos + strlen(fmt) + 20 /* slop */ < buffer + length)        \
762                         pos += sprintf(pos, fmt , ## args);                     \
763         } while(0)
764 static char *lprint_Scsi_Cmnd(Scsi_Cmnd *cmd, char *pos, char *buffer, int length);
765
766 static int NCR5380_proc_info(struct Scsi_Host *instance, char *buffer,
767                              char **start, off_t offset, int length, int inout)
768 {
769         char *pos = buffer;
770         struct NCR5380_hostdata *hostdata;
771         Scsi_Cmnd *ptr;
772         unsigned long flags;
773         off_t begin = 0;
774 #define check_offset()                                  \
775         do {                                            \
776                 if (pos - buffer < offset - begin) {    \
777                         begin += pos - buffer;          \
778                         pos = buffer;                   \
779                 }                                       \
780         } while (0)
781
782         hostdata = (struct NCR5380_hostdata *)instance->hostdata;
783
784         if (inout)                      /* Has data been written to the file ? */
785                 return -ENOSYS;         /* Currently this is a no-op */
786         SPRINTF("NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
787         check_offset();
788         local_irq_save(flags);
789         SPRINTF("NCR5380: coroutine is%s running.\n",
790                 main_running ? "" : "n't");
791         check_offset();
792         if (!hostdata->connected)
793                 SPRINTF("scsi%d: no currently connected command\n", HOSTNO);
794         else
795                 pos = lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected,
796                                        pos, buffer, length);
797         SPRINTF("scsi%d: issue_queue\n", HOSTNO);
798         check_offset();
799         for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr)) {
800                 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
801                 check_offset();
802         }
803
804         SPRINTF("scsi%d: disconnected_queue\n", HOSTNO);
805         check_offset();
806         for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
807              ptr = NEXT(ptr)) {
808                 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
809                 check_offset();
810         }
811
812         local_irq_restore(flags);
813         *start = buffer + (offset - begin);
814         if (pos - buffer < offset - begin)
815                 return 0;
816         else if (pos - buffer - (offset - begin) < length)
817                 return pos - buffer - (offset - begin);
818         return length;
819 }
820
821 static char *lprint_Scsi_Cmnd(Scsi_Cmnd *cmd, char *pos, char *buffer, int length)
822 {
823         int i, s;
824         unsigned char *command;
825         SPRINTF("scsi%d: destination target %d, lun %d\n",
826                 H_NO(cmd), cmd->device->id, cmd->device->lun);
827         SPRINTF("        command = ");
828         command = cmd->cmnd;
829         SPRINTF("%2d (0x%02x)", command[0], command[0]);
830         for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
831                 SPRINTF(" %02x", command[i]);
832         SPRINTF("\n");
833         return pos;
834 }
835
836
837 /*
838  * Function : void NCR5380_init (struct Scsi_Host *instance)
839  *
840  * Purpose : initializes *instance and corresponding 5380 chip.
841  *
842  * Inputs : instance - instantiation of the 5380 driver.
843  *
844  * Notes : I assume that the host, hostno, and id bits have been
845  *      set correctly.  I don't care about the irq and other fields.
846  *
847  */
848
849 static int NCR5380_init(struct Scsi_Host *instance, int flags)
850 {
851         int i;
852         SETUP_HOSTDATA(instance);
853
854         NCR5380_all_init();
855
856         hostdata->aborted = 0;
857         hostdata->id_mask = 1 << instance->this_id;
858         hostdata->id_higher_mask = 0;
859         for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
860                 if (i > hostdata->id_mask)
861                         hostdata->id_higher_mask |= i;
862         for (i = 0; i < 8; ++i)
863                 hostdata->busy[i] = 0;
864 #ifdef SUPPORT_TAGS
865         init_tags();
866 #endif
867 #if defined (REAL_DMA)
868         hostdata->dma_len = 0;
869 #endif
870         hostdata->targets_present = 0;
871         hostdata->connected = NULL;
872         hostdata->issue_queue = NULL;
873         hostdata->disconnected_queue = NULL;
874         hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;
875
876         if (!the_template) {
877                 the_template = instance->hostt;
878                 first_instance = instance;
879         }
880
881 #ifndef AUTOSENSE
882         if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1))
883                 printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n"
884                        "        without AUTOSENSE option, contingent allegiance conditions may\n"
885                        "        be incorrectly cleared.\n", HOSTNO);
886 #endif /* def AUTOSENSE */
887
888         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
889         NCR5380_write(MODE_REG, MR_BASE);
890         NCR5380_write(TARGET_COMMAND_REG, 0);
891         NCR5380_write(SELECT_ENABLE_REG, 0);
892
893         return 0;
894 }
895
896 /*
897  * our own old-style timeout update
898  */
899 /*
900  * The strategy is to cause the timer code to call scsi_times_out()
901  * when the soonest timeout is pending.
902  * The arguments are used when we are queueing a new command, because
903  * we do not want to subtract the time used from this time, but when we
904  * set the timer, we want to take this value into account.
905  */
906
907 int atari_scsi_update_timeout(Scsi_Cmnd * SCset, int timeout)
908 {
909         int rtn;
910
911         /*
912          * We are using the new error handling code to actually register/deregister
913          * timers for timeout.
914          */
915
916         if (!timer_pending(&SCset->eh_timeout))
917                 rtn = 0;
918         else
919                 rtn = SCset->eh_timeout.expires - jiffies;
920
921         if (timeout == 0) {
922                 del_timer(&SCset->eh_timeout);
923                 SCset->eh_timeout.data = (unsigned long)NULL;
924                 SCset->eh_timeout.expires = 0;
925         } else {
926                 if (SCset->eh_timeout.data != (unsigned long)NULL)
927                         del_timer(&SCset->eh_timeout);
928                 SCset->eh_timeout.data = (unsigned long)SCset;
929                 SCset->eh_timeout.expires = jiffies + timeout;
930                 add_timer(&SCset->eh_timeout);
931         }
932         return rtn;
933 }
934
935 /*
936  * Function : int NCR5380_queue_command (Scsi_Cmnd *cmd,
937  *      void (*done)(Scsi_Cmnd *))
938  *
939  * Purpose :  enqueues a SCSI command
940  *
941  * Inputs : cmd - SCSI command, done - function called on completion, with
942  *      a pointer to the command descriptor.
943  *
944  * Returns : 0
945  *
946  * Side effects :
947  *      cmd is added to the per instance issue_queue, with minor
948  *      twiddling done to the host specific fields of cmd.  If the
949  *      main coroutine is not running, it is restarted.
950  *
951  */
952
953 static int NCR5380_queue_command(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
954 {
955         SETUP_HOSTDATA(cmd->device->host);
956         Scsi_Cmnd *tmp;
957         int oldto;
958         unsigned long flags;
959         // extern int update_timeout(Scsi_Cmnd * SCset, int timeout);
960
961 #if (NDEBUG & NDEBUG_NO_WRITE)
962         switch (cmd->cmnd[0]) {
963         case WRITE_6:
964         case WRITE_10:
965                 printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
966                        H_NO(cmd));
967                 cmd->result = (DID_ERROR << 16);
968                 done(cmd);
969                 return 0;
970         }
971 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
972
973 #ifdef NCR5380_STATS
974 # if 0
975         if (!hostdata->connected && !hostdata->issue_queue &&
976             !hostdata->disconnected_queue) {
977                 hostdata->timebase = jiffies;
978         }
979 # endif
980 # ifdef NCR5380_STAT_LIMIT
981         if (cmd->request_bufflen > NCR5380_STAT_LIMIT)
982 # endif
983                 switch (cmd->cmnd[0]) {
984                 case WRITE:
985                 case WRITE_6:
986                 case WRITE_10:
987                         hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
988                         hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen;
989                         hostdata->pendingw++;
990                         break;
991                 case READ:
992                 case READ_6:
993                 case READ_10:
994                         hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
995                         hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen;
996                         hostdata->pendingr++;
997                         break;
998                 }
999 #endif
1000
1001         /*
1002          * We use the host_scribble field as a pointer to the next command
1003          * in a queue
1004          */
1005
1006         SET_NEXT(cmd, NULL);
1007         cmd->scsi_done = done;
1008
1009         cmd->result = 0;
1010
1011         /*
1012          * Insert the cmd into the issue queue. Note that REQUEST SENSE
1013          * commands are added to the head of the queue since any command will
1014          * clear the contingent allegiance condition that exists and the
1015          * sense data is only guaranteed to be valid while the condition exists.
1016          */
1017
1018         local_irq_save(flags);
1019         /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
1020          * Otherwise a running NCR5380_main may steal the lock.
1021          * Lock before actually inserting due to fairness reasons explained in
1022          * atari_scsi.c. If we insert first, then it's impossible for this driver
1023          * to release the lock.
1024          * Stop timer for this command while waiting for the lock, or timeouts
1025          * may happen (and they really do), and it's no good if the command doesn't
1026          * appear in any of the queues.
1027          * ++roman: Just disabling the NCR interrupt isn't sufficient here,
1028          * because also a timer int can trigger an abort or reset, which would
1029          * alter queues and touch the lock.
1030          */
1031         if (!IS_A_TT()) {
1032                 oldto = atari_scsi_update_timeout(cmd, 0);
1033                 falcon_get_lock();
1034                 atari_scsi_update_timeout(cmd, oldto);
1035         }
1036         if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1037                 LIST(cmd, hostdata->issue_queue);
1038                 SET_NEXT(cmd, hostdata->issue_queue);
1039                 hostdata->issue_queue = cmd;
1040         } else {
1041                 for (tmp = (Scsi_Cmnd *)hostdata->issue_queue;
1042                      NEXT(tmp); tmp = NEXT(tmp))
1043                         ;
1044                 LIST(cmd, tmp);
1045                 SET_NEXT(tmp, cmd);
1046         }
1047         local_irq_restore(flags);
1048
1049         QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd),
1050                   (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
1051
1052         /* If queue_command() is called from an interrupt (real one or bottom
1053          * half), we let queue_main() do the job of taking care about main. If it
1054          * is already running, this is a no-op, else main will be queued.
1055          *
1056          * If we're not in an interrupt, we can call NCR5380_main()
1057          * unconditionally, because it cannot be already running.
1058          */
1059         if (in_interrupt() || ((flags >> 8) & 7) >= 6)
1060                 queue_main();
1061         else
1062                 NCR5380_main(NULL);
1063         return 0;
1064 }
1065
1066 /*
1067  * Function : NCR5380_main (void)
1068  *
1069  * Purpose : NCR5380_main is a coroutine that runs as long as more work can
1070  *      be done on the NCR5380 host adapters in a system.  Both
1071  *      NCR5380_queue_command() and NCR5380_intr() will try to start it
1072  *      in case it is not running.
1073  *
1074  * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should
1075  *  reenable them.  This prevents reentrancy and kernel stack overflow.
1076  */
1077
1078 static void NCR5380_main(struct work_struct *work)
1079 {
1080         Scsi_Cmnd *tmp, *prev;
1081         struct Scsi_Host *instance = first_instance;
1082         struct NCR5380_hostdata *hostdata = HOSTDATA(instance);
1083         int done;
1084         unsigned long flags;
1085
1086         /*
1087          * We run (with interrupts disabled) until we're sure that none of
1088          * the host adapters have anything that can be done, at which point
1089          * we set main_running to 0 and exit.
1090          *
1091          * Interrupts are enabled before doing various other internal
1092          * instructions, after we've decided that we need to run through
1093          * the loop again.
1094          *
1095          * this should prevent any race conditions.
1096          *
1097          * ++roman: Just disabling the NCR interrupt isn't sufficient here,
1098          * because also a timer int can trigger an abort or reset, which can
1099          * alter queues and touch the Falcon lock.
1100          */
1101
1102         /* Tell int handlers main() is now already executing.  Note that
1103            no races are possible here. If an int comes in before
1104            'main_running' is set here, and queues/executes main via the
1105            task queue, it doesn't do any harm, just this instance of main
1106            won't find any work left to do. */
1107         if (main_running)
1108                 return;
1109         main_running = 1;
1110
1111         local_save_flags(flags);
1112         do {
1113                 local_irq_disable();    /* Freeze request queues */
1114                 done = 1;
1115
1116                 if (!hostdata->connected) {
1117                         MAIN_PRINTK("scsi%d: not connected\n", HOSTNO);
1118                         /*
1119                          * Search through the issue_queue for a command destined
1120                          * for a target that's not busy.
1121                          */
1122 #if (NDEBUG & NDEBUG_LISTS)
1123                         for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL;
1124                              tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
1125                                 ;
1126                         /*printk("%p  ", tmp);*/
1127                         if ((tmp == prev) && tmp)
1128                                 printk(" LOOP\n");
1129                         /* else printk("\n"); */
1130 #endif
1131                         for (tmp = (Scsi_Cmnd *) hostdata->issue_queue,
1132                              prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
1133
1134 #if (NDEBUG & NDEBUG_LISTS)
1135                                 if (prev != tmp)
1136                                         printk("MAIN tmp=%p   target=%d   busy=%d lun=%d\n",
1137                                                tmp, tmp->device->id, hostdata->busy[tmp->device->id],
1138                                                tmp->device->lun);
1139 #endif
1140                                 /*  When we find one, remove it from the issue queue. */
1141                                 /* ++guenther: possible race with Falcon locking */
1142                                 if (
1143 #ifdef SUPPORT_TAGS
1144                                     !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
1145 #else
1146                                     !(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))
1147 #endif
1148                                     ) {
1149                                         /* ++guenther: just to be sure, this must be atomic */
1150                                         local_irq_disable();
1151                                         if (prev) {
1152                                                 REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
1153                                                 SET_NEXT(prev, NEXT(tmp));
1154                                         } else {
1155                                                 REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
1156                                                 hostdata->issue_queue = NEXT(tmp);
1157                                         }
1158                                         SET_NEXT(tmp, NULL);
1159                                         falcon_dont_release++;
1160
1161                                         /* reenable interrupts after finding one */
1162                                         local_irq_restore(flags);
1163
1164                                         /*
1165                                          * Attempt to establish an I_T_L nexus here.
1166                                          * On success, instance->hostdata->connected is set.
1167                                          * On failure, we must add the command back to the
1168                                          *   issue queue so we can keep trying.
1169                                          */
1170                                         MAIN_PRINTK("scsi%d: main(): command for target %d "
1171                                                     "lun %d removed from issue_queue\n",
1172                                                     HOSTNO, tmp->device->id, tmp->device->lun);
1173                                         /*
1174                                          * REQUEST SENSE commands are issued without tagged
1175                                          * queueing, even on SCSI-II devices because the
1176                                          * contingent allegiance condition exists for the
1177                                          * entire unit.
1178                                          */
1179                                         /* ++roman: ...and the standard also requires that
1180                                          * REQUEST SENSE command are untagged.
1181                                          */
1182
1183 #ifdef SUPPORT_TAGS
1184                                         cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
1185 #endif
1186                                         if (!NCR5380_select(instance, tmp,
1187                                             (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE :
1188                                             TAG_NEXT)) {
1189                                                 falcon_dont_release--;
1190                                                 /* release if target did not response! */
1191                                                 falcon_release_lock_if_possible(hostdata);
1192                                                 break;
1193                                         } else {
1194                                                 local_irq_disable();
1195                                                 LIST(tmp, hostdata->issue_queue);
1196                                                 SET_NEXT(tmp, hostdata->issue_queue);
1197                                                 hostdata->issue_queue = tmp;
1198 #ifdef SUPPORT_TAGS
1199                                                 cmd_free_tag(tmp);
1200 #endif
1201                                                 falcon_dont_release--;
1202                                                 local_irq_restore(flags);
1203                                                 MAIN_PRINTK("scsi%d: main(): select() failed, "
1204                                                             "returned to issue_queue\n", HOSTNO);
1205                                                 if (hostdata->connected)
1206                                                         break;
1207                                         }
1208                                 } /* if target/lun/target queue is not busy */
1209                         } /* for issue_queue */
1210                 } /* if (!hostdata->connected) */
1211
1212                 if (hostdata->connected
1213 #ifdef REAL_DMA
1214                     && !hostdata->dma_len
1215 #endif
1216                     ) {
1217                         local_irq_restore(flags);
1218                         MAIN_PRINTK("scsi%d: main: performing information transfer\n",
1219                                     HOSTNO);
1220                         NCR5380_information_transfer(instance);
1221                         MAIN_PRINTK("scsi%d: main: done set false\n", HOSTNO);
1222                         done = 0;
1223                 }
1224         } while (!done);
1225
1226         /* Better allow ints _after_ 'main_running' has been cleared, else
1227            an interrupt could believe we'll pick up the work it left for
1228            us, but we won't see it anymore here... */
1229         main_running = 0;
1230         local_irq_restore(flags);
1231 }
1232
1233
1234 #ifdef REAL_DMA
1235 /*
1236  * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
1237  *
1238  * Purpose : Called by interrupt handler when DMA finishes or a phase
1239  *      mismatch occurs (which would finish the DMA transfer).
1240  *
1241  * Inputs : instance - this instance of the NCR5380.
1242  *
1243  */
1244
1245 static void NCR5380_dma_complete(struct Scsi_Host *instance)
1246 {
1247         SETUP_HOSTDATA(instance);
1248         int transfered, saved_data = 0, overrun = 0, cnt, toPIO;
1249         unsigned char **data, p;
1250         volatile int *count;
1251
1252         if (!hostdata->connected) {
1253                 printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
1254                        "no connected cmd\n", HOSTNO);
1255                 return;
1256         }
1257
1258         if (atari_read_overruns) {
1259                 p = hostdata->connected->SCp.phase;
1260                 if (p & SR_IO) {
1261                         udelay(10);
1262                         if ((NCR5380_read(BUS_AND_STATUS_REG) &
1263                              (BASR_PHASE_MATCH|BASR_ACK)) ==
1264                             (BASR_PHASE_MATCH|BASR_ACK)) {
1265                                 saved_data = NCR5380_read(INPUT_DATA_REG);
1266                                 overrun = 1;
1267                                 DMA_PRINTK("scsi%d: read overrun handled\n", HOSTNO);
1268                         }
1269                 }
1270         }
1271
1272         DMA_PRINTK("scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
1273                    HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
1274                    NCR5380_read(STATUS_REG));
1275
1276         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1277         NCR5380_write(MODE_REG, MR_BASE);
1278         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1279
1280         transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
1281         hostdata->dma_len = 0;
1282
1283         data = (unsigned char **)&hostdata->connected->SCp.ptr;
1284         count = &hostdata->connected->SCp.this_residual;
1285         *data += transfered;
1286         *count -= transfered;
1287
1288         if (atari_read_overruns) {
1289                 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
1290                         cnt = toPIO = atari_read_overruns;
1291                         if (overrun) {
1292                                 DMA_PRINTK("Got an input overrun, using saved byte\n");
1293                                 *(*data)++ = saved_data;
1294                                 (*count)--;
1295                                 cnt--;
1296                                 toPIO--;
1297                         }
1298                         DMA_PRINTK("Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
1299                         NCR5380_transfer_pio(instance, &p, &cnt, data);
1300                         *count -= toPIO - cnt;
1301                 }
1302         }
1303 }
1304 #endif /* REAL_DMA */
1305
1306
1307 /*
1308  * Function : void NCR5380_intr (int irq)
1309  *
1310  * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1311  *      from the disconnected queue, and restarting NCR5380_main()
1312  *      as required.
1313  *
1314  * Inputs : int irq, irq that caused this interrupt.
1315  *
1316  */
1317
1318 static irqreturn_t NCR5380_intr(int irq, void *dev_id)
1319 {
1320         struct Scsi_Host *instance = first_instance;
1321         int done = 1, handled = 0;
1322         unsigned char basr;
1323
1324         INT_PRINTK("scsi%d: NCR5380 irq triggered\n", HOSTNO);
1325
1326         /* Look for pending interrupts */
1327         basr = NCR5380_read(BUS_AND_STATUS_REG);
1328         INT_PRINTK("scsi%d: BASR=%02x\n", HOSTNO, basr);
1329         /* dispatch to appropriate routine if found and done=0 */
1330         if (basr & BASR_IRQ) {
1331                 NCR_PRINT(NDEBUG_INTR);
1332                 if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
1333                         done = 0;
1334                         ENABLE_IRQ();
1335                         INT_PRINTK("scsi%d: SEL interrupt\n", HOSTNO);
1336                         NCR5380_reselect(instance);
1337                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1338                 } else if (basr & BASR_PARITY_ERROR) {
1339                         INT_PRINTK("scsi%d: PARITY interrupt\n", HOSTNO);
1340                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1341                 } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1342                         INT_PRINTK("scsi%d: RESET interrupt\n", HOSTNO);
1343                         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1344                 } else {
1345                         /*
1346                          * The rest of the interrupt conditions can occur only during a
1347                          * DMA transfer
1348                          */
1349
1350 #if defined(REAL_DMA)
1351                         /*
1352                          * We should only get PHASE MISMATCH and EOP interrupts if we have
1353                          * DMA enabled, so do a sanity check based on the current setting
1354                          * of the MODE register.
1355                          */
1356
1357                         if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
1358                             ((basr & BASR_END_DMA_TRANSFER) ||
1359                              !(basr & BASR_PHASE_MATCH))) {
1360
1361                                 INT_PRINTK("scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
1362                                 NCR5380_dma_complete( instance );
1363                                 done = 0;
1364                                 ENABLE_IRQ();
1365                         } else
1366 #endif /* REAL_DMA */
1367                         {
1368 /* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
1369                                 if (basr & BASR_PHASE_MATCH)
1370                                         printk(KERN_NOTICE "scsi%d: unknown interrupt, "
1371                                                "BASR 0x%x, MR 0x%x, SR 0x%x\n",
1372                                                HOSTNO, basr, NCR5380_read(MODE_REG),
1373                                                NCR5380_read(STATUS_REG));
1374                                 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1375                         }
1376                 } /* if !(SELECTION || PARITY) */
1377                 handled = 1;
1378         } /* BASR & IRQ */ else {
1379                 printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
1380                        "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
1381                        NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
1382                 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1383         }
1384
1385         if (!done) {
1386                 INT_PRINTK("scsi%d: in int routine, calling main\n", HOSTNO);
1387                 /* Put a call to NCR5380_main() on the queue... */
1388                 queue_main();
1389         }
1390         return IRQ_RETVAL(handled);
1391 }
1392
1393 #ifdef NCR5380_STATS
1394 static void collect_stats(struct NCR5380_hostdata* hostdata, Scsi_Cmnd *cmd)
1395 {
1396 # ifdef NCR5380_STAT_LIMIT
1397         if (cmd->request_bufflen > NCR5380_STAT_LIMIT)
1398 # endif
1399                 switch (cmd->cmnd[0]) {
1400                 case WRITE:
1401                 case WRITE_6:
1402                 case WRITE_10:
1403                         hostdata->time_write[cmd->device->id] += (jiffies - hostdata->timebase);
1404                         /*hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen;*/
1405                         hostdata->pendingw--;
1406                         break;
1407                 case READ:
1408                 case READ_6:
1409                 case READ_10:
1410                         hostdata->time_read[cmd->device->id] += (jiffies - hostdata->timebase);
1411                         /*hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen;*/
1412                         hostdata->pendingr--;
1413                         break;
1414                 }
1415 }
1416 #endif
1417
1418 /*
1419  * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1420  *      int tag);
1421  *
1422  * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1423  *      including ARBITRATION, SELECTION, and initial message out for
1424  *      IDENTIFY and queue messages.
1425  *
1426  * Inputs : instance - instantiation of the 5380 driver on which this
1427  *      target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1428  *      new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1429  *      the command that is presently connected.
1430  *
1431  * Returns : -1 if selection could not execute for some reason,
1432  *      0 if selection succeeded or failed because the target
1433  *      did not respond.
1434  *
1435  * Side effects :
1436  *      If bus busy, arbitration failed, etc, NCR5380_select() will exit
1437  *              with registers as they should have been on entry - ie
1438  *              SELECT_ENABLE will be set appropriately, the NCR5380
1439  *              will cease to drive any SCSI bus signals.
1440  *
1441  *      If successful : I_T_L or I_T_L_Q nexus will be established,
1442  *              instance->connected will be set to cmd.
1443  *              SELECT interrupt will be disabled.
1444  *
1445  *      If failed (no target) : cmd->scsi_done() will be called, and the
1446  *              cmd->result host byte set to DID_BAD_TARGET.
1447  */
1448
1449 static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd *cmd, int tag)
1450 {
1451         SETUP_HOSTDATA(instance);
1452         unsigned char tmp[3], phase;
1453         unsigned char *data;
1454         int len;
1455         unsigned long timeout;
1456         unsigned long flags;
1457
1458         hostdata->restart_select = 0;
1459         NCR_PRINT(NDEBUG_ARBITRATION);
1460         ARB_PRINTK("scsi%d: starting arbitration, id = %d\n", HOSTNO,
1461                    instance->this_id);
1462
1463         /*
1464          * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1465          * data bus during SELECTION.
1466          */
1467
1468         local_irq_save(flags);
1469         if (hostdata->connected) {
1470                 local_irq_restore(flags);
1471                 return -1;
1472         }
1473         NCR5380_write(TARGET_COMMAND_REG, 0);
1474
1475         /*
1476          * Start arbitration.
1477          */
1478
1479         NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1480         NCR5380_write(MODE_REG, MR_ARBITRATE);
1481
1482         local_irq_restore(flags);
1483
1484         /* Wait for arbitration logic to complete */
1485 #if defined(NCR_TIMEOUT)
1486         {
1487                 unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
1488
1489                 while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1490                        time_before(jiffies, timeout) && !hostdata->connected)
1491                         ;
1492                 if (time_after_eq(jiffies, timeout)) {
1493                         printk("scsi : arbitration timeout at %d\n", __LINE__);
1494                         NCR5380_write(MODE_REG, MR_BASE);
1495                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1496                         return -1;
1497                 }
1498         }
1499 #else /* NCR_TIMEOUT */
1500         while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1501                !hostdata->connected)
1502                 ;
1503 #endif
1504
1505         ARB_PRINTK("scsi%d: arbitration complete\n", HOSTNO);
1506
1507         if (hostdata->connected) {
1508                 NCR5380_write(MODE_REG, MR_BASE);
1509                 return -1;
1510         }
1511         /*
1512          * The arbitration delay is 2.2us, but this is a minimum and there is
1513          * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1514          * the integral nature of udelay().
1515          *
1516          */
1517
1518         udelay(3);
1519
1520         /* Check for lost arbitration */
1521         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1522             (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1523             (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1524             hostdata->connected) {
1525                 NCR5380_write(MODE_REG, MR_BASE);
1526                 ARB_PRINTK("scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
1527                            HOSTNO);
1528                 return -1;
1529         }
1530
1531         /* after/during arbitration, BSY should be asserted.
1532            IBM DPES-31080 Version S31Q works now */
1533         /* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
1534         NCR5380_write(INITIATOR_COMMAND_REG,
1535                       ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1536
1537         if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1538             hostdata->connected) {
1539                 NCR5380_write(MODE_REG, MR_BASE);
1540                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1541                 ARB_PRINTK("scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
1542                            HOSTNO);
1543                 return -1;
1544         }
1545
1546         /*
1547          * Again, bus clear + bus settle time is 1.2us, however, this is
1548          * a minimum so we'll udelay ceil(1.2)
1549          */
1550
1551 #ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
1552         /* ++roman: But some targets (see above :-) seem to need a bit more... */
1553         udelay(15);
1554 #else
1555         udelay(2);
1556 #endif
1557
1558         if (hostdata->connected) {
1559                 NCR5380_write(MODE_REG, MR_BASE);
1560                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1561                 return -1;
1562         }
1563
1564         ARB_PRINTK("scsi%d: won arbitration\n", HOSTNO);
1565
1566         /*
1567          * Now that we have won arbitration, start Selection process, asserting
1568          * the host and target ID's on the SCSI bus.
1569          */
1570
1571         NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));
1572
1573         /*
1574          * Raise ATN while SEL is true before BSY goes false from arbitration,
1575          * since this is the only way to guarantee that we'll get a MESSAGE OUT
1576          * phase immediately after selection.
1577          */
1578
1579         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
1580                       ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
1581         NCR5380_write(MODE_REG, MR_BASE);
1582
1583         /*
1584          * Reselect interrupts must be turned off prior to the dropping of BSY,
1585          * otherwise we will trigger an interrupt.
1586          */
1587
1588         if (hostdata->connected) {
1589                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1590                 return -1;
1591         }
1592
1593         NCR5380_write(SELECT_ENABLE_REG, 0);
1594
1595         /*
1596          * The initiator shall then wait at least two deskew delays and release
1597          * the BSY signal.
1598          */
1599         udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */
1600
1601         /* Reset BSY */
1602         NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
1603                       ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1604
1605         /*
1606          * Something weird happens when we cease to drive BSY - looks
1607          * like the board/chip is letting us do another read before the
1608          * appropriate propagation delay has expired, and we're confusing
1609          * a BSY signal from ourselves as the target's response to SELECTION.
1610          *
1611          * A small delay (the 'C++' frontend breaks the pipeline with an
1612          * unnecessary jump, making it work on my 386-33/Trantor T128, the
1613          * tighter 'C' code breaks and requires this) solves the problem -
1614          * the 1 us delay is arbitrary, and only used because this delay will
1615          * be the same on other platforms and since it works here, it should
1616          * work there.
1617          *
1618          * wingel suggests that this could be due to failing to wait
1619          * one deskew delay.
1620          */
1621
1622         udelay(1);
1623
1624         SEL_PRINTK("scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
1625
1626         /*
1627          * The SCSI specification calls for a 250 ms timeout for the actual
1628          * selection.
1629          */
1630
1631         timeout = jiffies + 25;
1632
1633         /*
1634          * XXX very interesting - we're seeing a bounce where the BSY we
1635          * asserted is being reflected / still asserted (propagation delay?)
1636          * and it's detecting as true.  Sigh.
1637          */
1638
1639 #if 0
1640         /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
1641          * IO while SEL is true. But again, there are some disks out the in the
1642          * world that do that nevertheless. (Somebody claimed that this announces
1643          * reselection capability of the target.) So we better skip that test and
1644          * only wait for BSY... (Famous german words: Der Kl├╝gere gibt nach :-)
1645          */
1646
1647         while (time_before(jiffies, timeout) &&
1648                !(NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO)))
1649                 ;
1650
1651         if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1652                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1653                 NCR5380_reselect(instance);
1654                 printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
1655                        HOSTNO);
1656                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1657                 return -1;
1658         }
1659 #else
1660         while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
1661                 ;
1662 #endif
1663
1664         /*
1665          * No less than two deskew delays after the initiator detects the
1666          * BSY signal is true, it shall release the SEL signal and may
1667          * change the DATA BUS.                                     -wingel
1668          */
1669
1670         udelay(1);
1671
1672         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1673
1674         if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1675                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1676                 if (hostdata->targets_present & (1 << cmd->device->id)) {
1677                         printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
1678                         if (hostdata->restart_select)
1679                                 printk(KERN_NOTICE "\trestart select\n");
1680                         NCR_PRINT(NDEBUG_ANY);
1681                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1682                         return -1;
1683                 }
1684                 cmd->result = DID_BAD_TARGET << 16;
1685 #ifdef NCR5380_STATS
1686                 collect_stats(hostdata, cmd);
1687 #endif
1688 #ifdef SUPPORT_TAGS
1689                 cmd_free_tag(cmd);
1690 #endif
1691                 cmd->scsi_done(cmd);
1692                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1693                 SEL_PRINTK("scsi%d: target did not respond within 250ms\n", HOSTNO);
1694                 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1695                 return 0;
1696         }
1697
1698         hostdata->targets_present |= (1 << cmd->device->id);
1699
1700         /*
1701          * Since we followed the SCSI spec, and raised ATN while SEL
1702          * was true but before BSY was false during selection, the information
1703          * transfer phase should be a MESSAGE OUT phase so that we can send the
1704          * IDENTIFY message.
1705          *
1706          * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1707          * message (2 bytes) with a tag ID that we increment with every command
1708          * until it wraps back to 0.
1709          *
1710          * XXX - it turns out that there are some broken SCSI-II devices,
1711          *           which claim to support tagged queuing but fail when more than
1712          *           some number of commands are issued at once.
1713          */
1714
1715         /* Wait for start of REQ/ACK handshake */
1716         while (!(NCR5380_read(STATUS_REG) & SR_REQ))
1717                 ;
1718
1719         SEL_PRINTK("scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
1720                    HOSTNO, cmd->device->id);
1721         tmp[0] = IDENTIFY(1, cmd->device->lun);
1722
1723 #ifdef SUPPORT_TAGS
1724         if (cmd->tag != TAG_NONE) {
1725                 tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
1726                 tmp[2] = cmd->tag;
1727                 len = 3;
1728         } else
1729                 len = 1;
1730 #else
1731         len = 1;
1732         cmd->tag = 0;
1733 #endif /* SUPPORT_TAGS */
1734
1735         /* Send message(s) */
1736         data = tmp;
1737         phase = PHASE_MSGOUT;
1738         NCR5380_transfer_pio(instance, &phase, &len, &data);
1739         SEL_PRINTK("scsi%d: nexus established.\n", HOSTNO);
1740         /* XXX need to handle errors here */
1741         hostdata->connected = cmd;
1742 #ifndef SUPPORT_TAGS
1743         hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1744 #endif
1745
1746         initialize_SCp(cmd);
1747
1748         return 0;
1749 }
1750
1751 /*
1752  * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1753  *      unsigned char *phase, int *count, unsigned char **data)
1754  *
1755  * Purpose : transfers data in given phase using polled I/O
1756  *
1757  * Inputs : instance - instance of driver, *phase - pointer to
1758  *      what phase is expected, *count - pointer to number of
1759  *      bytes to transfer, **data - pointer to data pointer.
1760  *
1761  * Returns : -1 when different phase is entered without transferring
1762  *      maximum number of bytes, 0 if all bytes are transfered or exit
1763  *      is in same phase.
1764  *
1765  *      Also, *phase, *count, *data are modified in place.
1766  *
1767  * XXX Note : handling for bus free may be useful.
1768  */
1769
1770 /*
1771  * Note : this code is not as quick as it could be, however it
1772  * IS 100% reliable, and for the actual data transfer where speed
1773  * counts, we will always do a pseudo DMA or DMA transfer.
1774  */
1775
1776 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1777                                 unsigned char *phase, int *count,
1778                                 unsigned char **data)
1779 {
1780         register unsigned char p = *phase, tmp;
1781         register int c = *count;
1782         register unsigned char *d = *data;
1783
1784         /*
1785          * The NCR5380 chip will only drive the SCSI bus when the
1786          * phase specified in the appropriate bits of the TARGET COMMAND
1787          * REGISTER match the STATUS REGISTER
1788          */
1789
1790         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1791
1792         do {
1793                 /*
1794                  * Wait for assertion of REQ, after which the phase bits will be
1795                  * valid
1796                  */
1797                 while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1798                         ;
1799
1800                 HSH_PRINTK("scsi%d: REQ detected\n", HOSTNO);
1801
1802                 /* Check for phase mismatch */
1803                 if ((tmp & PHASE_MASK) != p) {
1804                         PIO_PRINTK("scsi%d: phase mismatch\n", HOSTNO);
1805                         NCR_PRINT_PHASE(NDEBUG_PIO);
1806                         break;
1807                 }
1808
1809                 /* Do actual transfer from SCSI bus to / from memory */
1810                 if (!(p & SR_IO))
1811                         NCR5380_write(OUTPUT_DATA_REG, *d);
1812                 else
1813                         *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1814
1815                 ++d;
1816
1817                 /*
1818                  * The SCSI standard suggests that in MSGOUT phase, the initiator
1819                  * should drop ATN on the last byte of the message phase
1820                  * after REQ has been asserted for the handshake but before
1821                  * the initiator raises ACK.
1822                  */
1823
1824                 if (!(p & SR_IO)) {
1825                         if (!((p & SR_MSG) && c > 1)) {
1826                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1827                                 NCR_PRINT(NDEBUG_PIO);
1828                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1829                                               ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1830                         } else {
1831                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1832                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1833                                 NCR_PRINT(NDEBUG_PIO);
1834                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1835                                               ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1836                         }
1837                 } else {
1838                         NCR_PRINT(NDEBUG_PIO);
1839                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1840                 }
1841
1842                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1843                         ;
1844
1845                 HSH_PRINTK("scsi%d: req false, handshake complete\n", HOSTNO);
1846
1847                 /*
1848                  * We have several special cases to consider during REQ/ACK handshaking :
1849                  * 1.  We were in MSGOUT phase, and we are on the last byte of the
1850                  *      message.  ATN must be dropped as ACK is dropped.
1851                  *
1852                  * 2.  We are in a MSGIN phase, and we are on the last byte of the
1853                  *      message.  We must exit with ACK asserted, so that the calling
1854                  *      code may raise ATN before dropping ACK to reject the message.
1855                  *
1856                  * 3.  ACK and ATN are clear and the target may proceed as normal.
1857                  */
1858                 if (!(p == PHASE_MSGIN && c == 1)) {
1859                         if (p == PHASE_MSGOUT && c > 1)
1860                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1861                         else
1862                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1863                 }
1864         } while (--c);
1865
1866         PIO_PRINTK("scsi%d: residual %d\n", HOSTNO, c);
1867
1868         *count = c;
1869         *data = d;
1870         tmp = NCR5380_read(STATUS_REG);
1871         /* The phase read from the bus is valid if either REQ is (already)
1872          * asserted or if ACK hasn't been released yet. The latter is the case if
1873          * we're in MSGIN and all wanted bytes have been received.
1874          */
1875         if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
1876                 *phase = tmp & PHASE_MASK;
1877         else
1878                 *phase = PHASE_UNKNOWN;
1879
1880         if (!c || (*phase == p))
1881                 return 0;
1882         else
1883                 return -1;
1884 }
1885
1886 /*
1887  * Function : do_abort (Scsi_Host *host)
1888  *
1889  * Purpose : abort the currently established nexus.  Should only be
1890  *      called from a routine which can drop into a
1891  *
1892  * Returns : 0 on success, -1 on failure.
1893  */
1894
1895 static int do_abort(struct Scsi_Host *host)
1896 {
1897         unsigned char tmp, *msgptr, phase;
1898         int len;
1899
1900         /* Request message out phase */
1901         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1902
1903         /*
1904          * Wait for the target to indicate a valid phase by asserting
1905          * REQ.  Once this happens, we'll have either a MSGOUT phase
1906          * and can immediately send the ABORT message, or we'll have some
1907          * other phase and will have to source/sink data.
1908          *
1909          * We really don't care what value was on the bus or what value
1910          * the target sees, so we just handshake.
1911          */
1912
1913         while (!(tmp = NCR5380_read(STATUS_REG)) & SR_REQ)
1914                 ;
1915
1916         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1917
1918         if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1919                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1920                               ICR_ASSERT_ACK);
1921                 while (NCR5380_read(STATUS_REG) & SR_REQ)
1922                         ;
1923                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1924         }
1925
1926         tmp = ABORT;
1927         msgptr = &tmp;
1928         len = 1;
1929         phase = PHASE_MSGOUT;
1930         NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1931
1932         /*
1933          * If we got here, and the command completed successfully,
1934          * we're about to go into bus free state.
1935          */
1936
1937         return len ? -1 : 0;
1938 }
1939
1940 #if defined(REAL_DMA)
1941 /*
1942  * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1943  *      unsigned char *phase, int *count, unsigned char **data)
1944  *
1945  * Purpose : transfers data in given phase using either real
1946  *      or pseudo DMA.
1947  *
1948  * Inputs : instance - instance of driver, *phase - pointer to
1949  *      what phase is expected, *count - pointer to number of
1950  *      bytes to transfer, **data - pointer to data pointer.
1951  *
1952  * Returns : -1 when different phase is entered without transferring
1953  *      maximum number of bytes, 0 if all bytes or transfered or exit
1954  *      is in same phase.
1955  *
1956  *      Also, *phase, *count, *data are modified in place.
1957  *
1958  */
1959
1960
1961 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1962                                 unsigned char *phase, int *count,
1963                                 unsigned char **data)
1964 {
1965         SETUP_HOSTDATA(instance);
1966         register int c = *count;
1967         register unsigned char p = *phase;
1968         register unsigned char *d = *data;
1969         unsigned char tmp;
1970         unsigned long flags;
1971
1972         if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1973                 *phase = tmp;
1974                 return -1;
1975         }
1976
1977         if (atari_read_overruns && (p & SR_IO))
1978                 c -= atari_read_overruns;
1979
1980         DMA_PRINTK("scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1981                    HOSTNO, (p & SR_IO) ? "reading" : "writing",
1982                    c, (p & SR_IO) ? "to" : "from", d);
1983
1984         NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1985
1986 #ifdef REAL_DMA
1987         NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1988 #endif /* def REAL_DMA  */
1989
1990         if (IS_A_TT()) {
1991                 /* On the Medusa, it is a must to initialize the DMA before
1992                  * starting the NCR. This is also the cleaner way for the TT.
1993                  */
1994                 local_irq_save(flags);
1995                 hostdata->dma_len = (p & SR_IO) ?
1996                         NCR5380_dma_read_setup(instance, d, c) :
1997                         NCR5380_dma_write_setup(instance, d, c);
1998                 local_irq_restore(flags);
1999         }
2000
2001         if (p & SR_IO)
2002                 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
2003         else {
2004                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
2005                 NCR5380_write(START_DMA_SEND_REG, 0);
2006         }
2007
2008         if (!IS_A_TT()) {
2009                 /* On the Falcon, the DMA setup must be done after the last */
2010                 /* NCR access, else the DMA setup gets trashed!
2011                  */
2012                 local_irq_save(flags);
2013                 hostdata->dma_len = (p & SR_IO) ?
2014                         NCR5380_dma_read_setup(instance, d, c) :
2015                         NCR5380_dma_write_setup(instance, d, c);
2016                 local_irq_restore(flags);
2017         }
2018         return 0;
2019 }
2020 #endif /* defined(REAL_DMA) */
2021
2022 /*
2023  * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
2024  *
2025  * Purpose : run through the various SCSI phases and do as the target
2026  *      directs us to.  Operates on the currently connected command,
2027  *      instance->connected.
2028  *
2029  * Inputs : instance, instance for which we are doing commands
2030  *
2031  * Side effects : SCSI things happen, the disconnected queue will be
2032  *      modified if a command disconnects, *instance->connected will
2033  *      change.
2034  *
2035  * XXX Note : we need to watch for bus free or a reset condition here
2036  *      to recover from an unexpected bus free condition.
2037  */
2038
2039 static void NCR5380_information_transfer(struct Scsi_Host *instance)
2040 {
2041         SETUP_HOSTDATA(instance);
2042         unsigned long flags;
2043         unsigned char msgout = NOP;
2044         int sink = 0;
2045         int len;
2046 #if defined(REAL_DMA)
2047         int transfersize;
2048 #endif
2049         unsigned char *data;
2050         unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2051         Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2052
2053         while (1) {
2054                 tmp = NCR5380_read(STATUS_REG);
2055                 /* We only have a valid SCSI phase when REQ is asserted */
2056                 if (tmp & SR_REQ) {
2057                         phase = (tmp & PHASE_MASK);
2058                         if (phase != old_phase) {
2059                                 old_phase = phase;
2060                                 NCR_PRINT_PHASE(NDEBUG_INFORMATION);
2061                         }
2062
2063                         if (sink && (phase != PHASE_MSGOUT)) {
2064                                 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2065
2066                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
2067                                               ICR_ASSERT_ACK);
2068                                 while (NCR5380_read(STATUS_REG) & SR_REQ)
2069                                         ;
2070                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2071                                               ICR_ASSERT_ATN);
2072                                 sink = 0;
2073                                 continue;
2074                         }
2075
2076                         switch (phase) {
2077                         case PHASE_DATAOUT:
2078 #if (NDEBUG & NDEBUG_NO_DATAOUT)
2079                                 printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
2080                                        "aborted\n", HOSTNO);
2081                                 sink = 1;
2082                                 do_abort(instance);
2083                                 cmd->result = DID_ERROR << 16;
2084                                 cmd->done(cmd);
2085                                 return;
2086 #endif
2087                         case PHASE_DATAIN:
2088                                 /*
2089                                  * If there is no room left in the current buffer in the
2090                                  * scatter-gather list, move onto the next one.
2091                                  */
2092
2093                                 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2094                                         ++cmd->SCp.buffer;
2095                                         --cmd->SCp.buffers_residual;
2096                                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
2097                                         cmd->SCp.ptr = page_address(cmd->SCp.buffer->page) +
2098                                                    cmd->SCp.buffer->offset;
2099                                         /* ++roman: Try to merge some scatter-buffers if
2100                                          * they are at contiguous physical addresses.
2101                                          */
2102                                         merge_contiguous_buffers(cmd);
2103                                         INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
2104                                                    HOSTNO, cmd->SCp.this_residual,
2105                                                    cmd->SCp.buffers_residual);
2106                                 }
2107
2108                                 /*
2109                                  * The preferred transfer method is going to be
2110                                  * PSEUDO-DMA for systems that are strictly PIO,
2111                                  * since we can let the hardware do the handshaking.
2112                                  *
2113                                  * For this to work, we need to know the transfersize
2114                                  * ahead of time, since the pseudo-DMA code will sit
2115                                  * in an unconditional loop.
2116                                  */
2117
2118                                 /* ++roman: I suggest, this should be
2119                                  *   #if def(REAL_DMA)
2120                                  * instead of leaving REAL_DMA out.
2121                                  */
2122
2123 #if defined(REAL_DMA)
2124                                 if (!cmd->device->borken &&
2125                                     (transfersize = NCR5380_dma_xfer_len(instance,cmd,phase)) > 31) {
2126                                         len = transfersize;
2127                                         cmd->SCp.phase = phase;
2128                                         if (NCR5380_transfer_dma(instance, &phase,
2129                                             &len, (unsigned char **)&cmd->SCp.ptr)) {
2130                                                 /*
2131                                                  * If the watchdog timer fires, all future
2132                                                  * accesses to this device will use the
2133                                                  * polled-IO. */
2134                                                 printk(KERN_NOTICE "scsi%d: switching target %d "
2135                                                            "lun %d to slow handshake\n", HOSTNO,
2136                                                            cmd->device->id, cmd->device->lun);
2137                                                 cmd->device->borken = 1;
2138                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2139                                                         ICR_ASSERT_ATN);
2140                                                 sink = 1;
2141                                                 do_abort(instance);
2142                                                 cmd->result = DID_ERROR << 16;
2143                                                 cmd->done(cmd);
2144                                                 /* XXX - need to source or sink data here, as appropriate */
2145                                         } else {
2146 #ifdef REAL_DMA
2147                                                 /* ++roman: When using real DMA,
2148                                                  * information_transfer() should return after
2149                                                  * starting DMA since it has nothing more to
2150                                                  * do.
2151                                                  */
2152                                                 return;
2153 #else
2154                                                 cmd->SCp.this_residual -= transfersize - len;
2155 #endif
2156                                         }
2157                                 } else
2158 #endif /* defined(REAL_DMA) */
2159                                         NCR5380_transfer_pio(instance, &phase,
2160                                                              (int *)&cmd->SCp.this_residual,
2161                                                              (unsigned char **)&cmd->SCp.ptr);
2162                                 break;
2163                         case PHASE_MSGIN:
2164                                 len = 1;
2165                                 data = &tmp;
2166                                 NCR5380_write(SELECT_ENABLE_REG, 0);    /* disable reselects */
2167                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2168                                 cmd->SCp.Message = tmp;
2169
2170                                 switch (tmp) {
2171                                 /*
2172                                  * Linking lets us reduce the time required to get the
2173                                  * next command out to the device, hopefully this will
2174                                  * mean we don't waste another revolution due to the delays
2175                                  * required by ARBITRATION and another SELECTION.
2176                                  *
2177                                  * In the current implementation proposal, low level drivers
2178                                  * merely have to start the next command, pointed to by
2179                                  * next_link, done() is called as with unlinked commands.
2180                                  */
2181 #ifdef LINKED
2182                                 case LINKED_CMD_COMPLETE:
2183                                 case LINKED_FLG_CMD_COMPLETE:
2184                                         /* Accept message by clearing ACK */
2185                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2186
2187                                         LNK_PRINTK("scsi%d: target %d lun %d linked command "
2188                                                    "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);
2189
2190                                         /* Enable reselect interrupts */
2191                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2192                                         /*
2193                                          * Sanity check : A linked command should only terminate
2194                                          * with one of these messages if there are more linked
2195                                          * commands available.
2196                                          */
2197
2198                                         if (!cmd->next_link) {
2199                                                  printk(KERN_NOTICE "scsi%d: target %d lun %d "
2200                                                         "linked command complete, no next_link\n",
2201                                                         HOSTNO, cmd->device->id, cmd->device->lun);
2202                                                 sink = 1;
2203                                                 do_abort(instance);
2204                                                 return;
2205                                         }
2206
2207                                         initialize_SCp(cmd->next_link);
2208                                         /* The next command is still part of this process; copy it
2209                                          * and don't free it! */
2210                                         cmd->next_link->tag = cmd->tag;
2211                                         cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2212                                         LNK_PRINTK("scsi%d: target %d lun %d linked request "
2213                                                    "done, calling scsi_done().\n",
2214                                                    HOSTNO, cmd->device->id, cmd->device->lun);
2215 #ifdef NCR5380_STATS
2216                                         collect_stats(hostdata, cmd);
2217 #endif
2218                                         cmd->scsi_done(cmd);
2219                                         cmd = hostdata->connected;
2220                                         break;
2221 #endif /* def LINKED */
2222                                 case ABORT:
2223                                 case COMMAND_COMPLETE:
2224                                         /* Accept message by clearing ACK */
2225                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2226                                         /* ++guenther: possible race with Falcon locking */
2227                                         falcon_dont_release++;
2228                                         hostdata->connected = NULL;
2229                                         QU_PRINTK("scsi%d: command for target %d, lun %d "
2230                                                   "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
2231 #ifdef SUPPORT_TAGS
2232                                         cmd_free_tag(cmd);
2233                                         if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
2234                                                 /* Turn a QUEUE FULL status into BUSY, I think the
2235                                                  * mid level cannot handle QUEUE FULL :-( (The
2236                                                  * command is retried after BUSY). Also update our
2237                                                  * queue size to the number of currently issued
2238                                                  * commands now.
2239                                                  */
2240                                                 /* ++Andreas: the mid level code knows about
2241                                                    QUEUE_FULL now. */
2242                                                 TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
2243                                                 TAG_PRINTK("scsi%d: target %d lun %d returned "
2244                                                            "QUEUE_FULL after %d commands\n",
2245                                                            HOSTNO, cmd->device->id, cmd->device->lun,
2246                                                            ta->nr_allocated);
2247                                                 if (ta->queue_size > ta->nr_allocated)
2248                                                         ta->nr_allocated = ta->queue_size;
2249                                         }
2250 #else
2251                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2252 #endif
2253                                         /* Enable reselect interrupts */
2254                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2255
2256                                         /*
2257                                          * I'm not sure what the correct thing to do here is :
2258                                          *
2259                                          * If the command that just executed is NOT a request
2260                                          * sense, the obvious thing to do is to set the result
2261                                          * code to the values of the stored parameters.
2262                                          *
2263                                          * If it was a REQUEST SENSE command, we need some way to
2264                                          * differentiate between the failure code of the original
2265                                          * and the failure code of the REQUEST sense - the obvious
2266                                          * case is success, where we fall through and leave the
2267                                          * result code unchanged.
2268                                          *
2269                                          * The non-obvious place is where the REQUEST SENSE failed
2270                                          */
2271
2272                                         if (cmd->cmnd[0] != REQUEST_SENSE)
2273                                                 cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2274                                         else if (status_byte(cmd->SCp.Status) != GOOD)
2275                                                 cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2276
2277 #ifdef AUTOSENSE
2278                                         if ((cmd->cmnd[0] != REQUEST_SENSE) &&
2279                                             (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2280                                                 ASEN_PRINTK("scsi%d: performing request sense\n", HOSTNO);
2281                                                 cmd->cmnd[0] = REQUEST_SENSE;
2282                                                 cmd->cmnd[1] &= 0xe0;
2283                                                 cmd->cmnd[2] = 0;
2284                                                 cmd->cmnd[3] = 0;
2285                                                 cmd->cmnd[4] = sizeof(cmd->sense_buffer);
2286                                                 cmd->cmnd[5] = 0;
2287                                                 cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
2288
2289                                                 cmd->use_sg = 0;
2290                                                 /* this is initialized from initialize_SCp
2291                                                 cmd->SCp.buffer = NULL;
2292                                                 cmd->SCp.buffers_residual = 0;
2293                                                 */
2294                                                 cmd->request_buffer = (char *) cmd->sense_buffer;
2295                                                 cmd->request_bufflen = sizeof(cmd->sense_buffer);
2296
2297                                                 local_irq_save(flags);
2298                                                 LIST(cmd,hostdata->issue_queue);
2299                                                 SET_NEXT(cmd, hostdata->issue_queue);
2300                                                 hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2301                                                 local_irq_restore(flags);
2302                                                 QU_PRINTK("scsi%d: REQUEST SENSE added to head of "
2303                                                           "issue queue\n", H_NO(cmd));
2304                                         } else
2305 #endif /* def AUTOSENSE */
2306                                         {
2307 #ifdef NCR5380_STATS
2308                                                 collect_stats(hostdata, cmd);
2309 #endif
2310                                                 cmd->scsi_done(cmd);
2311                                         }
2312
2313                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2314                                         /*
2315                                          * Restore phase bits to 0 so an interrupted selection,
2316                                          * arbitration can resume.
2317                                          */
2318                                         NCR5380_write(TARGET_COMMAND_REG, 0);
2319
2320                                         while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2321                                                 barrier();
2322
2323                                         falcon_dont_release--;
2324                                         /* ++roman: For Falcon SCSI, release the lock on the
2325                                          * ST-DMA here if no other commands are waiting on the
2326                                          * disconnected queue.
2327                                          */
2328                                         falcon_release_lock_if_possible(hostdata);
2329                                         return;
2330                                 case MESSAGE_REJECT:
2331                                         /* Accept message by clearing ACK */
2332                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2333                                         /* Enable reselect interrupts */
2334                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2335                                         switch (hostdata->last_message) {
2336                                         case HEAD_OF_QUEUE_TAG:
2337                                         case ORDERED_QUEUE_TAG:
2338                                         case SIMPLE_QUEUE_TAG:
2339                                                 /* The target obviously doesn't support tagged
2340                                                  * queuing, even though it announced this ability in
2341                                                  * its INQUIRY data ?!? (maybe only this LUN?) Ok,
2342                                                  * clear 'tagged_supported' and lock the LUN, since
2343                                                  * the command is treated as untagged further on.
2344                                                  */
2345                                                 cmd->device->tagged_supported = 0;
2346                                                 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2347                                                 cmd->tag = TAG_NONE;
2348                                                 TAG_PRINTK("scsi%d: target %d lun %d rejected "
2349                                                            "QUEUE_TAG message; tagged queuing "
2350                                                            "disabled\n",
2351                                                            HOSTNO, cmd->device->id, cmd->device->lun);
2352                                                 break;
2353                                         }
2354                                         break;
2355                                 case DISCONNECT:
2356                                         /* Accept message by clearing ACK */
2357                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2358                                         local_irq_save(flags);
2359                                         cmd->device->disconnect = 1;
2360                                         LIST(cmd,hostdata->disconnected_queue);
2361                                         SET_NEXT(cmd, hostdata->disconnected_queue);
2362                                         hostdata->connected = NULL;
2363                                         hostdata->disconnected_queue = cmd;
2364                                         local_irq_restore(flags);
2365                                         QU_PRINTK("scsi%d: command for target %d lun %d was "
2366                                                   "moved from connected to the "
2367                                                   "disconnected_queue\n", HOSTNO,
2368                                                   cmd->device->id, cmd->device->lun);
2369                                         /*
2370                                          * Restore phase bits to 0 so an interrupted selection,
2371                                          * arbitration can resume.
2372                                          */
2373                                         NCR5380_write(TARGET_COMMAND_REG, 0);
2374
2375                                         /* Enable reselect interrupts */
2376                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2377                                         /* Wait for bus free to avoid nasty timeouts */
2378                                         while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2379                                                 barrier();
2380                                         return;
2381                                         /*
2382                                          * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2383                                          * operation, in violation of the SCSI spec so we can safely
2384                                          * ignore SAVE/RESTORE pointers calls.
2385                                          *
2386                                          * Unfortunately, some disks violate the SCSI spec and
2387                                          * don't issue the required SAVE_POINTERS message before
2388                                          * disconnecting, and we have to break spec to remain
2389                                          * compatible.
2390                                          */
2391                                 case SAVE_POINTERS:
2392                                 case RESTORE_POINTERS:
2393                                         /* Accept message by clearing ACK */
2394                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2395                                         /* Enable reselect interrupts */
2396                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2397                                         break;
2398                                 case EXTENDED_MESSAGE:
2399                                         /*
2400                                          * Extended messages are sent in the following format :
2401                                          * Byte
2402                                          * 0            EXTENDED_MESSAGE == 1
2403                                          * 1            length (includes one byte for code, doesn't
2404                                          *              include first two bytes)
2405                                          * 2            code
2406                                          * 3..length+1  arguments
2407                                          *
2408                                          * Start the extended message buffer with the EXTENDED_MESSAGE
2409                                          * byte, since spi_print_msg() wants the whole thing.
2410                                          */
2411                                         extended_msg[0] = EXTENDED_MESSAGE;
2412                                         /* Accept first byte by clearing ACK */
2413                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2414
2415                                         EXT_PRINTK("scsi%d: receiving extended message\n", HOSTNO);
2416
2417                                         len = 2;
2418                                         data = extended_msg + 1;
2419                                         phase = PHASE_MSGIN;
2420                                         NCR5380_transfer_pio(instance, &phase, &len, &data);
2421                                         EXT_PRINTK("scsi%d: length=%d, code=0x%02x\n", HOSTNO,
2422                                                    (int)extended_msg[1], (int)extended_msg[2]);
2423
2424                                         if (!len && extended_msg[1] <=
2425                                             (sizeof(extended_msg) - 1)) {
2426                                                 /* Accept third byte by clearing ACK */
2427                                                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2428                                                 len = extended_msg[1] - 1;
2429                                                 data = extended_msg + 3;
2430                                                 phase = PHASE_MSGIN;
2431
2432                                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2433                                                 EXT_PRINTK("scsi%d: message received, residual %d\n",
2434                                                            HOSTNO, len);
2435
2436                                                 switch (extended_msg[2]) {
2437                                                 case EXTENDED_SDTR:
2438                                                 case EXTENDED_WDTR:
2439                                                 case EXTENDED_MODIFY_DATA_POINTER:
2440                                                 case EXTENDED_EXTENDED_IDENTIFY:
2441                                                         tmp = 0;
2442                                                 }
2443                                         } else if (len) {
2444                                                 printk(KERN_NOTICE "scsi%d: error receiving "
2445                                                        "extended message\n", HOSTNO);
2446                                                 tmp = 0;
2447                                         } else {
2448                                                 printk(KERN_NOTICE "scsi%d: extended message "
2449                                                            "code %02x length %d is too long\n",
2450                                                            HOSTNO, extended_msg[2], extended_msg[1]);
2451                                                 tmp = 0;
2452                                         }
2453                                         /* Fall through to reject message */
2454
2455                                         /*
2456                                          * If we get something weird that we aren't expecting,
2457                                          * reject it.
2458                                          */
2459                                 default:
2460                                         if (!tmp) {
2461                                                 printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
2462                                                 spi_print_msg(extended_msg);
2463                                                 printk("\n");
2464                                         } else if (tmp != EXTENDED_MESSAGE)
2465                                                 printk(KERN_DEBUG "scsi%d: rejecting unknown "
2466                                                        "message %02x from target %d, lun %d\n",
2467                                                        HOSTNO, tmp, cmd->device->id, cmd->device->lun);
2468                                         else
2469                                                 printk(KERN_DEBUG "scsi%d: rejecting unknown "
2470                                                        "extended message "
2471                                                        "code %02x, length %d from target %d, lun %d\n",
2472                                                        HOSTNO, extended_msg[1], extended_msg[0],
2473                                                        cmd->device->id, cmd->device->lun);
2474
2475
2476                                         msgout = MESSAGE_REJECT;
2477                                         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2478                                         break;
2479                                 } /* switch (tmp) */
2480                                 break;
2481                         case PHASE_MSGOUT:
2482                                 len = 1;
2483                                 data = &msgout;
2484                                 hostdata->last_message = msgout;
2485                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2486                                 if (msgout == ABORT) {
2487 #ifdef SUPPORT_TAGS
2488                                         cmd_free_tag(cmd);
2489 #else
2490                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2491 #endif
2492                                         hostdata->connected = NULL;
2493                                         cmd->result = DID_ERROR << 16;
2494 #ifdef NCR5380_STATS
2495                                         collect_stats(hostdata, cmd);
2496 #endif
2497                                         cmd->scsi_done(cmd);
2498                                         NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2499                                         falcon_release_lock_if_possible(hostdata);
2500                                         return;
2501                                 }
2502                                 msgout = NOP;
2503                                 break;
2504                         case PHASE_CMDOUT:
2505                                 len = cmd->cmd_len;
2506                                 data = cmd->cmnd;
2507                                 /*
2508                                  * XXX for performance reasons, on machines with a
2509                                  * PSEUDO-DMA architecture we should probably
2510                                  * use the dma transfer function.
2511                                  */
2512                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2513                                 break;
2514                         case PHASE_STATIN:
2515                                 len = 1;
2516                                 data = &tmp;
2517                                 NCR5380_transfer_pio(instance, &phase, &len, &data);
2518                                 cmd->SCp.Status = tmp;
2519                                 break;
2520                         default:
2521                                 printk("scsi%d: unknown phase\n", HOSTNO);
2522                                 NCR_PRINT(NDEBUG_ANY);
2523                         } /* switch(phase) */
2524                 } /* if (tmp * SR_REQ) */
2525         } /* while (1) */
2526 }
2527
2528 /*
2529  * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2530  *
2531  * Purpose : does reselection, initializing the instance->connected
2532  *      field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2533  *      nexus has been reestablished,
2534  *
2535  * Inputs : instance - this instance of the NCR5380.
2536  *
2537  */
2538
2539
2540 static void NCR5380_reselect(struct Scsi_Host *instance)
2541 {
2542         SETUP_HOSTDATA(instance);
2543         unsigned char target_mask;
2544         unsigned char lun, phase;
2545         int len;
2546 #ifdef SUPPORT_TAGS
2547         unsigned char tag;
2548 #endif
2549         unsigned char msg[3];
2550         unsigned char *data;
2551         Scsi_Cmnd *tmp = NULL, *prev;
2552 /*      unsigned long flags; */
2553
2554         /*
2555          * Disable arbitration, etc. since the host adapter obviously
2556          * lost, and tell an interrupted NCR5380_select() to restart.
2557          */
2558
2559         NCR5380_write(MODE_REG, MR_BASE);
2560         hostdata->restart_select = 1;
2561
2562         target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2563
2564         RSL_PRINTK("scsi%d: reselect\n", HOSTNO);
2565
2566         /*
2567          * At this point, we have detected that our SCSI ID is on the bus,
2568          * SEL is true and BSY was false for at least one bus settle delay
2569          * (400 ns).
2570          *
2571          * We must assert BSY ourselves, until the target drops the SEL
2572          * signal.
2573          */
2574
2575         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2576
2577         while (NCR5380_read(STATUS_REG) & SR_SEL)
2578                 ;
2579         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2580
2581         /*
2582          * Wait for target to go into MSGIN.
2583          */
2584
2585         while (!(NCR5380_read(STATUS_REG) & SR_REQ))
2586                 ;
2587
2588         len = 1;
2589         data = msg;
2590         phase = PHASE_MSGIN;
2591         NCR5380_transfer_pio(instance, &phase, &len, &data);
2592
2593         if (!(msg[0] & 0x80)) {
2594                 printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
2595                 spi_print_msg(msg);
2596                 do_abort(instance);
2597                 return;
2598         }
2599         lun = (msg[0] & 0x07);
2600
2601 #ifdef SUPPORT_TAGS
2602         /* If the phase is still MSGIN, the target wants to send some more
2603          * messages. In case it supports tagged queuing, this is probably a
2604          * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2605          */
2606         tag = TAG_NONE;
2607         if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
2608                 /* Accept previous IDENTIFY message by clearing ACK */
2609                 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2610                 len = 2;
2611                 data = msg + 1;
2612                 if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2613                     msg[1] == SIMPLE_QUEUE_TAG)
2614                         tag = msg[2];
2615                 TAG_PRINTK("scsi%d: target mask %02x, lun %d sent tag %d at "
2616                            "reselection\n", HOSTNO, target_mask, lun, tag);
2617         }
2618 #endif
2619
2620         /*
2621          * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
2622          * just reestablished, and remove it from the disconnected queue.
2623          */
2624
2625         for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL;
2626              tmp; prev = tmp, tmp = NEXT(tmp)) {
2627                 if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2628 #ifdef SUPPORT_TAGS
2629                     && (tag == tmp->tag)
2630 #endif
2631                     ) {
2632                         /* ++guenther: prevent race with falcon_release_lock */
2633                         falcon_dont_release++;
2634                         if (prev) {
2635                                 REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2636                                 SET_NEXT(prev, NEXT(tmp));
2637                         } else {
2638                                 REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
2639                                 hostdata->disconnected_queue = NEXT(tmp);
2640                         }
2641                         SET_NEXT(tmp, NULL);
2642                         break;
2643                 }
2644         }
2645
2646         if (!tmp) {
2647                 printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
2648 #ifdef SUPPORT_TAGS
2649                        "tag %d "
2650 #endif
2651                        "not in disconnected_queue.\n",
2652                        HOSTNO, target_mask, lun
2653 #ifdef SUPPORT_TAGS
2654                        , tag
2655 #endif
2656                         );
2657                 /*
2658                  * Since we have an established nexus that we can't do anything
2659                  * with, we must abort it.
2660                  */
2661                 do_abort(instance);
2662                 return;
2663         }
2664
2665         /* Accept message by clearing ACK */
2666         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2667
2668         hostdata->connected = tmp;
2669         RSL_PRINTK("scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
2670                    HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
2671         falcon_dont_release--;
2672 }
2673
2674
2675 /*
2676  * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2677  *
2678  * Purpose : abort a command
2679  *
2680  * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2681  *      host byte of the result field to, if zero DID_ABORTED is
2682  *      used.
2683  *
2684  * Returns : 0 - success, -1 on failure.
2685  *
2686  * XXX - there is no way to abort the command that is currently
2687  *       connected, you have to wait for it to complete.  If this is
2688  *       a problem, we could implement longjmp() / setjmp(), setjmp()
2689  *       called where the loop started in NCR5380_main().
2690  */
2691
2692 static
2693 int NCR5380_abort(Scsi_Cmnd *cmd)
2694 {
2695         struct Scsi_Host *instance = cmd->device->host;
2696         SETUP_HOSTDATA(instance);
2697         Scsi_Cmnd *tmp, **prev;
2698         unsigned long flags;
2699
2700         printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
2701         scsi_print_command(cmd);
2702
2703         NCR5380_print_status(instance);
2704
2705         local_irq_save(flags);
2706
2707         if (!IS_A_TT() && !falcon_got_lock)
2708                 printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_abort\n",
2709                        HOSTNO);
2710
2711         ABRT_PRINTK("scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
2712                     NCR5380_read(BUS_AND_STATUS_REG),
2713                     NCR5380_read(STATUS_REG));
2714
2715 #if 1
2716         /*
2717          * Case 1 : If the command is the currently executing command,
2718          * we'll set the aborted flag and return control so that
2719          * information transfer routine can exit cleanly.
2720          */
2721
2722         if (hostdata->connected == cmd) {
2723
2724                 ABRT_PRINTK("scsi%d: aborting connected command\n", HOSTNO);
2725                 /*
2726                  * We should perform BSY checking, and make sure we haven't slipped
2727                  * into BUS FREE.
2728                  */
2729
2730                 /*      NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
2731                 /*
2732                  * Since we can't change phases until we've completed the current
2733                  * handshake, we have to source or sink a byte of data if the current
2734                  * phase is not MSGOUT.
2735                  */
2736
2737                 /*
2738                  * Return control to the executing NCR drive so we can clear the
2739                  * aborted flag and get back into our main loop.
2740                  */
2741
2742                 if (do_abort(instance) == 0) {
2743                         hostdata->aborted = 1;
2744                         hostdata->connected = NULL;
2745                         cmd->result = DID_ABORT << 16;
2746 #ifdef SUPPORT_TAGS
2747                         cmd_free_tag(cmd);
2748 #else
2749                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2750 #endif
2751                         local_irq_restore(flags);
2752                         cmd->scsi_done(cmd);
2753                         falcon_release_lock_if_possible(hostdata);
2754                         return SCSI_ABORT_SUCCESS;
2755                 } else {
2756 /*                      local_irq_restore(flags); */
2757                         printk("scsi%d: abort of connected command failed!\n", HOSTNO);
2758                         return SCSI_ABORT_ERROR;
2759                 }
2760         }
2761 #endif
2762
2763         /*
2764          * Case 2 : If the command hasn't been issued yet, we simply remove it
2765          *          from the issue queue.
2766          */
2767         for (prev = (Scsi_Cmnd **)&(hostdata->issue_queue),
2768              tmp = (Scsi_Cmnd *)hostdata->issue_queue;
2769              tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2770                 if (cmd == tmp) {
2771                         REMOVE(5, *prev, tmp, NEXT(tmp));
2772                         (*prev) = NEXT(tmp);
2773                         SET_NEXT(tmp, NULL);
2774                         tmp->result = DID_ABORT << 16;
2775                         local_irq_restore(flags);
2776                         ABRT_PRINTK("scsi%d: abort removed command from issue queue.\n",
2777                                     HOSTNO);
2778                         /* Tagged queuing note: no tag to free here, hasn't been assigned
2779                          * yet... */
2780                         tmp->scsi_done(tmp);
2781                         falcon_release_lock_if_possible(hostdata);
2782                         return SCSI_ABORT_SUCCESS;
2783                 }
2784         }
2785
2786         /*
2787          * Case 3 : If any commands are connected, we're going to fail the abort
2788          *          and let the high level SCSI driver retry at a later time or
2789          *          issue a reset.
2790          *
2791          *          Timeouts, and therefore aborted commands, will be highly unlikely
2792          *          and handling them cleanly in this situation would make the common
2793          *          case of noresets less efficient, and would pollute our code.  So,
2794          *          we fail.
2795          */
2796
2797         if (hostdata->connected) {
2798                 local_irq_restore(flags);
2799                 ABRT_PRINTK("scsi%d: abort failed, command connected.\n", HOSTNO);
2800                 return SCSI_ABORT_SNOOZE;
2801         }
2802
2803         /*
2804          * Case 4: If the command is currently disconnected from the bus, and
2805          *      there are no connected commands, we reconnect the I_T_L or
2806          *      I_T_L_Q nexus associated with it, go into message out, and send
2807          *      an abort message.
2808          *
2809          * This case is especially ugly. In order to reestablish the nexus, we
2810          * need to call NCR5380_select().  The easiest way to implement this
2811          * function was to abort if the bus was busy, and let the interrupt
2812          * handler triggered on the SEL for reselect take care of lost arbitrations
2813          * where necessary, meaning interrupts need to be enabled.
2814          *
2815          * When interrupts are enabled, the queues may change - so we
2816          * can't remove it from the disconnected queue before selecting it
2817          * because that could cause a failure in hashing the nexus if that
2818          * device reselected.
2819          *
2820          * Since the queues may change, we can't use the pointers from when we
2821          * first locate it.
2822          *
2823          * So, we must first locate the command, and if NCR5380_select()
2824          * succeeds, then issue the abort, relocate the command and remove
2825          * it from the disconnected queue.
2826          */
2827
2828         for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp;
2829              tmp = NEXT(tmp)) {
2830                 if (cmd == tmp) {
2831                         local_irq_restore(flags);
2832                         ABRT_PRINTK("scsi%d: aborting disconnected command.\n", HOSTNO);
2833
2834                         if (NCR5380_select(instance, cmd, (int)cmd->tag))
2835                                 return SCSI_ABORT_BUSY;
2836
2837                         ABRT_PRINTK("scsi%d: nexus reestablished.\n", HOSTNO);
2838
2839                         do_abort(instance);
2840
2841                         local_irq_save(flags);
2842                         for (prev = (Scsi_Cmnd **)&(hostdata->disconnected_queue),
2843                              tmp = (Scsi_Cmnd *)hostdata->disconnected_queue;
2844                              tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2845                                 if (cmd == tmp) {
2846                                         REMOVE(5, *prev, tmp, NEXT(tmp));
2847                                         *prev = NEXT(tmp);
2848                                         SET_NEXT(tmp, NULL);
2849                                         tmp->result = DID_ABORT << 16;
2850                                         /* We must unlock the tag/LUN immediately here, since the
2851                                          * target goes to BUS FREE and doesn't send us another
2852                                          * message (COMMAND_COMPLETE or the like)
2853                                          */
2854 #ifdef SUPPORT_TAGS
2855                                         cmd_free_tag(tmp);
2856 #else
2857                                         hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2858 #endif
2859                                         local_irq_restore(flags);
2860                                         tmp->scsi_done(tmp);
2861                                         falcon_release_lock_if_possible(hostdata);
2862                                         return SCSI_ABORT_SUCCESS;
2863                                 }
2864                         }
2865                 }
2866         }
2867
2868         /*
2869          * Case 5 : If we reached this point, the command was not found in any of
2870          *          the queues.
2871          *
2872          * We probably reached this point because of an unlikely race condition
2873          * between the command completing successfully and the abortion code,
2874          * so we won't panic, but we will notify the user in case something really
2875          * broke.
2876          */
2877
2878         local_irq_restore(flags);
2879         printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully\n"
2880                KERN_INFO "        before abortion\n", HOSTNO);
2881
2882         /* Maybe it is sufficient just to release the ST-DMA lock... (if
2883          * possible at all) At least, we should check if the lock could be
2884          * released after the abort, in case it is kept due to some bug.
2885          */
2886         falcon_release_lock_if_possible(hostdata);
2887
2888         return SCSI_ABORT_NOT_RUNNING;
2889 }
2890
2891
2892 /*
2893  * Function : int NCR5380_reset (Scsi_Cmnd *cmd)
2894  *
2895  * Purpose : reset the SCSI bus.
2896  *
2897  * Returns : SCSI_RESET_WAKEUP
2898  *
2899  */
2900
2901 static int NCR5380_bus_reset(Scsi_Cmnd *cmd)
2902 {
2903         SETUP_HOSTDATA(cmd->device->host);
2904         int i;
2905         unsigned long flags;
2906 #if 1
2907         Scsi_Cmnd *connected, *disconnected_queue;
2908 #endif
2909
2910         if (!IS_A_TT() && !falcon_got_lock)
2911                 printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_reset\n",
2912                        H_NO(cmd));
2913
2914         NCR5380_print_status(cmd->device->host);
2915
2916         /* get in phase */
2917         NCR5380_write(TARGET_COMMAND_REG,
2918                       PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
2919         /* assert RST */
2920         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
2921         udelay(40);
2922         /* reset NCR registers */
2923         NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2924         NCR5380_write(MODE_REG, MR_BASE);
2925         NCR5380_write(TARGET_COMMAND_REG, 0);
2926         NCR5380_write(SELECT_ENABLE_REG, 0);
2927         /* ++roman: reset interrupt condition! otherwise no interrupts don't get
2928          * through anymore ... */
2929         (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2930
2931 #if 1   /* XXX Should now be done by midlevel code, but it's broken XXX */
2932         /* XXX see below                                            XXX */
2933
2934         /* MSch: old-style reset: actually abort all command processing here */
2935
2936         /* After the reset, there are no more connected or disconnected commands
2937          * and no busy units; to avoid problems with re-inserting the commands
2938          * into the issue_queue (via scsi_done()), the aborted commands are
2939          * remembered in local variables first.
2940          */
2941         local_irq_save(flags);
2942         connected = (Scsi_Cmnd *)hostdata->connected;
2943         hostdata->connected = NULL;
2944         disconnected_queue = (Scsi_Cmnd *)hostdata->disconnected_queue;
2945         hostdata->disconnected_queue = NULL;
2946 #ifdef SUPPORT_TAGS
2947         free_all_tags();
2948 #endif
2949         for (i = 0; i < 8; ++i)
2950                 hostdata->busy[i] = 0;
2951 #ifdef REAL_DMA
2952         hostdata->dma_len = 0;
2953 #endif
2954         local_irq_restore(flags);
2955
2956         /* In order to tell the mid-level code which commands were aborted,
2957          * set the command status to DID_RESET and call scsi_done() !!!
2958          * This ultimately aborts processing of these commands in the mid-level.
2959          */
2960
2961         if ((cmd = connected)) {
2962                 ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2963                 cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2964                 cmd->scsi_done(cmd);
2965         }
2966
2967         for (i = 0; (cmd = disconnected_queue); ++i) {
2968                 disconnected_queue = NEXT(cmd);
2969                 SET_NEXT(cmd, NULL);
2970                 cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2971                 cmd->scsi_done(cmd);
2972         }
2973         if (i > 0)
2974                 ABRT_PRINTK("scsi: reset aborted %d disconnected command(s)\n", i);
2975
2976         /* The Falcon lock should be released after a reset...
2977          */
2978         /* ++guenther: moved to atari_scsi_reset(), to prevent a race between
2979          * unlocking and enabling dma interrupt.
2980          */
2981 /*      falcon_release_lock_if_possible( hostdata );*/
2982
2983         /* since all commands have been explicitly terminated, we need to tell
2984          * the midlevel code that the reset was SUCCESSFUL, and there is no
2985          * need to 'wake up' the commands by a request_sense
2986          */
2987         return SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET;
2988 #else /* 1 */
2989
2990         /* MSch: new-style reset handling: let the mid-level do what it can */
2991
2992         /* ++guenther: MID-LEVEL IS STILL BROKEN.
2993          * Mid-level is supposed to requeue all commands that were active on the
2994          * various low-level queues. In fact it does this, but that's not enough
2995          * because all these commands are subject to timeout. And if a timeout
2996          * happens for any removed command, *_abort() is called but all queues
2997          * are now empty. Abort then gives up the falcon lock, which is fatal,
2998          * since the mid-level will queue more commands and must have the lock
2999          * (it's all happening inside timer interrupt handler!!).
3000          * Even worse, abort will return NOT_RUNNING for all those commands not
3001          * on any queue, so they won't be retried ...
3002          *
3003          * Conclusion: either scsi.c disables timeout for all resetted commands
3004          * immediately, or we lose!  As of linux-2.0.20 it doesn't.
3005          */
3006
3007         /* After the reset, there are no more connected or disconnected commands
3008          * and no busy units; so clear the low-level status here to avoid
3009          * conflicts when the mid-level code tries to wake up the affected
3010          * commands!
3011          */
3012
3013         if (hostdata->issue_queue)
3014                 ABRT_PRINTK("scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
3015         if (hostdata->connected)
3016                 ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
3017         if (hostdata->disconnected_queue)
3018                 ABRT_PRINTK("scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));
3019
3020         local_irq_save(flags);
3021         hostdata->issue_queue = NULL;
3022         hostdata->connected = NULL;
3023         hostdata->disconnected_queue = NULL;
3024 #ifdef SUPPORT_TAGS
3025         free_all_tags();
3026 #endif
3027         for (i = 0; i < 8; ++i)
3028                 hostdata->busy[i] = 0;
3029 #ifdef REAL_DMA
3030         hostdata->dma_len = 0;
3031 #endif
3032         local_irq_restore(flags);
3033
3034         /* we did no complete reset of all commands, so a wakeup is required */
3035         return SCSI_RESET_WAKEUP | SCSI_RESET_BUS_RESET;
3036 #endif /* 1 */
3037 }