| blob | 9c5694a2da8a99d225415c5e4be52ca195503ece |
1 #undef DEBUG
2 #undef EVENTS
3 #undef NO_SELECTION_TIMEOUT
4 #define BIG_ENDIAN
6 ; 53c710 driver. Modified from Drew Eckhardts driver
7 ; for 53c810 by Richard Hirst [richard@sleepie.demon.co.uk]
8 ;
9 ; I have left the script for the 53c8xx family in here, as it is likely
10 ; to be useful to see what I changed when bug hunting.
12 ; NCR 53c810 driver, main script
13 ; Sponsored by
14 ; iX Multiuser Multitasking Magazine
15 ; hm@ix.de
16 ;
17 ; Copyright 1993, 1994, 1995 Drew Eckhardt
18 ; Visionary Computing
19 ; (Unix and Linux consulting and custom programming)
20 ; drew@PoohSticks.ORG
21 ; +1 (303) 786-7975
22 ;
23 ; TolerANT and SCSI SCRIPTS are registered trademarks of NCR Corporation.
24 ;
25 ; PRE-ALPHA
26 ;
27 ; For more information, please consult
28 ;
29 ; NCR 53C810
30 ; PCI-SCSI I/O Processor
31 ; Data Manual
32 ;
33 ; NCR 53C710
34 ; SCSI I/O Processor
35 ; Programmers Guide
36 ;
37 ; NCR Microelectronics
38 ; 1635 Aeroplaza Drive
39 ; Colorado Springs, CO 80916
40 ; 1+ (719) 578-3400
41 ;
42 ; Toll free literature number
43 ; +1 (800) 334-5454
44 ;
45 ; IMPORTANT : This code is self modifying due to the limitations of
46 ; the NCR53c7,8xx series chips. Persons debugging this code with
47 ; the remote debugger should take this into account, and NOT set
48 ; breakpoints in modified instructions.
49 ;
50 ; Design:
51 ; The NCR53c7,8xx family of SCSI chips are busmasters with an onboard
52 ; microcontroller using a simple instruction set.
53 ;
54 ; So, to minimize the effects of interrupt latency, and to maximize
55 ; throughput, this driver offloads the practical maximum amount
56 ; of processing to the SCSI chip while still maintaining a common
57 ; structure.
58 ;
59 ; Where tradeoffs were needed between efficiency on the older
60 ; chips and the newer NCR53c800 series, the NCR53c800 series
61 ; was chosen.
62 ;
63 ; While the NCR53c700 and NCR53c700-66 lacked the facilities to fully
64 ; automate SCSI transfers without host processor intervention, this
65 ; isn't the case with the NCR53c710 and newer chips which allow
66 ;
67 ; - reads and writes to the internal registers from within the SCSI
68 ; scripts, allowing the SCSI SCRIPTS(tm) code to save processor
69 ; state so that multiple threads of execution are possible, and also
70 ; provide an ALU for loop control, etc.
71 ;
72 ; - table indirect addressing for some instructions. This allows
73 ; pointers to be located relative to the DSA ((Data Structure
74 ; Address) register.
75 ;
76 ; These features make it possible to implement a mailbox style interface,
77 ; where the same piece of code is run to handle I/O for multiple threads
78 ; at once minimizing our need to relocate code. Since the NCR53c700/
79 ; NCR53c800 series have a unique combination of features, making a
80 ; a standard ingoing/outgoing mailbox system, costly, I've modified it.
81 ;
82 ; - Mailboxes are a mixture of code and data. This lets us greatly
83 ; simplify the NCR53c810 code and do things that would otherwise
84 ; not be possible.
85 ;
86 ; The saved data pointer is now implemented as follows :
87 ;
88 ; Control flow has been architected such that if control reaches
89 ; munge_save_data_pointer, on a restore pointers message or
90 ; reconnection, a jump to the address formerly in the TEMP register
91 ; will allow the SCSI command to resume execution.
92 ;
94 ;
95 ; Note : the DSA structures must be aligned on 32 bit boundaries,
96 ; since the source and destination of MOVE MEMORY instructions
97 ; must share the same alignment and this is the alignment of the
98 ; NCR registers.
99 ;
101 ; For some systems (MVME166, for example) dmode is always the same, so don't
102 ; waste time writing it
104 #if 1
105 #define DMODE_MEMORY_TO_NCR
106 #define DMODE_MEMORY_TO_MEMORY
107 #define DMODE_NCR_TO_MEMORY
108 #else
109 #define DMODE_MEMORY_TO_NCR MOVE dmode_memory_to_ncr TO DMODE
110 #define DMODE_MEMORY_TO_MEMORY MOVE dmode_memory_to_memory TO DMODE
111 #define DMODE_NCR_TO_MEMORY MOVE dmode_ncr_to_memory TO DMODE
112 #endif
114 ABSOLUTE dsa_temp_lun = 0 ; Patch to lun for current dsa
115 ABSOLUTE dsa_temp_next = 0 ; Patch to dsa next for current dsa
116 ABSOLUTE dsa_temp_addr_next = 0 ; Patch to address of dsa next address
117 ; for current dsa
118 ABSOLUTE dsa_temp_sync = 0 ; Patch to address of per-target
119 ; sync routine
120 ABSOLUTE dsa_sscf_710 = 0 ; Patch to address of per-target
121 ; sscf value (53c710)
122 ABSOLUTE dsa_temp_target = 0 ; Patch to id for current dsa
123 ABSOLUTE dsa_temp_addr_saved_pointer = 0; Patch to address of per-command
124 ; saved data pointer
125 ABSOLUTE dsa_temp_addr_residual = 0 ; Patch to address of per-command
126 ; current residual code
127 ABSOLUTE dsa_temp_addr_saved_residual = 0; Patch to address of per-command
128 ; saved residual code
129 ABSOLUTE dsa_temp_addr_new_value = 0 ; Address of value for JUMP operand
130 ABSOLUTE dsa_temp_addr_array_value = 0 ; Address to copy to
131 ABSOLUTE dsa_temp_addr_dsa_value = 0 ; Address of this DSA value
133 ;
134 ; Once a device has initiated reselection, we need to compare it
135 ; against the singly linked list of commands which have disconnected
136 ; and are pending reselection. These commands are maintained in
137 ; an unordered singly linked list of DSA structures, through the
138 ; DSA pointers at their 'centers' headed by the reconnect_dsa_head
139 ; pointer.
140 ;
141 ; To avoid complications in removing commands from the list,
142 ; I minimize the amount of expensive (at eight operations per
143 ; addition @ 500-600ns each) pointer operations which must
144 ; be done in the NCR driver by precomputing them on the
145 ; host processor during dsa structure generation.
146 ;
147 ; The fixed-up per DSA code knows how to recognize the nexus
148 ; associated with the corresponding SCSI command, and modifies
149 ; the source and destination pointers for the MOVE MEMORY
150 ; instruction which is executed when reselected_ok is called
151 ; to remove the command from the list. Similarly, DSA is
152 ; loaded with the address of the next DSA structure and
153 ; reselected_check_next is called if a failure occurs.
154 ;
155 ; Perhaps more concisely, the net effect of the mess is
156 ;
157 ; for (dsa = reconnect_dsa_head, dest = &reconnect_dsa_head,
158 ; src = NULL; dsa; dest = &dsa->next, dsa = dsa->next) {
159 ; src = &dsa->next;
160 ; if (target_id == dsa->id && target_lun == dsa->lun) {
161 ; *dest = *src;
162 ; break;
163 ; }
164 ; }
165 ;
166 ; if (!dsa)
167 ; error (int_err_unexpected_reselect);
168 ; else
169 ; longjmp (dsa->jump_resume, 0);
170 ;
171 ;
173 #if (CHIP != 700) && (CHIP != 70066)
174 ; Define DSA structure used for mailboxes
175 ENTRY dsa_code_template
176 dsa_code_template:
177 ENTRY dsa_code_begin
178 dsa_code_begin:
179 ; RGH: Don't care about TEMP and DSA here
180 DMODE_MEMORY_TO_NCR
181 MOVE MEMORY 4, dsa_temp_addr_dsa_value, addr_scratch
182 DMODE_MEMORY_TO_MEMORY
183 #if (CHIP == 710)
184 MOVE MEMORY 4, addr_scratch, saved_dsa
185 ; We are about to go and select the device, so must set SSCF bits
186 MOVE MEMORY 4, dsa_sscf_710, addr_scratch
187 #ifdef BIG_ENDIAN
188 MOVE SCRATCH3 TO SFBR
189 #else
190 MOVE SCRATCH0 TO SFBR
191 #endif
192 MOVE SFBR TO SBCL
193 MOVE MEMORY 4, saved_dsa, addr_dsa
194 #else
195 CALL scratch_to_dsa
196 #endif
197 CALL select
198 ; Handle the phase mismatch which may have resulted from the
199 ; MOVE FROM dsa_msgout if we returned here. The CLEAR ATN
200 ; may or may not be necessary, and we should update script_asm.pl
201 ; to handle multiple pieces.
202 CLEAR ATN
203 CLEAR ACK
205 ; Replace second operand with address of JUMP instruction dest operand
206 ; in schedule table for this DSA. Becomes dsa_jump_dest in 53c7,8xx.c.
207 ENTRY dsa_code_fix_jump
208 dsa_code_fix_jump:
209 MOVE MEMORY 4, NOP_insn, 0
210 JUMP select_done
212 ; wrong_dsa loads the DSA register with the value of the dsa_next
213 ; field.
214 ;
215 wrong_dsa:
216 #if (CHIP == 710)
217 ; NOTE DSA is corrupt when we arrive here!
218 #endif
219 ; Patch the MOVE MEMORY INSTRUCTION such that
220 ; the destination address is the address of the OLD
221 ; next pointer.
222 ;
223 MOVE MEMORY 4, dsa_temp_addr_next, reselected_ok_patch + 8
224 DMODE_MEMORY_TO_NCR
225 ;
226 ; Move the _contents_ of the next pointer into the DSA register as
227 ; the next I_T_L or I_T_L_Q tupple to check against the established
228 ; nexus.
229 ;
230 MOVE MEMORY 4, dsa_temp_next, addr_scratch
231 DMODE_MEMORY_TO_MEMORY
232 #if (CHIP == 710)
233 MOVE MEMORY 4, addr_scratch, saved_dsa
234 MOVE MEMORY 4, saved_dsa, addr_dsa
235 #else
236 CALL scratch_to_dsa
237 #endif
238 JUMP reselected_check_next
240 ABSOLUTE dsa_save_data_pointer = 0
241 ENTRY dsa_code_save_data_pointer
242 dsa_code_save_data_pointer:
243 #if (CHIP == 710)
244 ; When we get here, TEMP has been saved in jump_temp+4, DSA is corrupt
245 ; We MUST return with DSA correct
246 MOVE MEMORY 4, jump_temp+4, dsa_temp_addr_saved_pointer
247 ; HARD CODED : 24 bytes needs to agree with 53c7,8xx.h
248 MOVE MEMORY 24, dsa_temp_addr_residual, dsa_temp_addr_saved_residual
249 CLEAR ACK
250 #ifdef DEBUG
251 INT int_debug_saved
252 #endif
253 MOVE MEMORY 4, saved_dsa, addr_dsa
254 JUMP jump_temp
255 #else
256 DMODE_NCR_TO_MEMORY
257 MOVE MEMORY 4, addr_temp, dsa_temp_addr_saved_pointer
258 DMODE_MEMORY_TO_MEMORY
259 ; HARD CODED : 24 bytes needs to agree with 53c7,8xx.h
260 MOVE MEMORY 24, dsa_temp_addr_residual, dsa_temp_addr_saved_residual
261 CLEAR ACK
262 #ifdef DEBUG
263 INT int_debug_saved
264 #endif
265 RETURN
266 #endif
267 ABSOLUTE dsa_restore_pointers = 0
268 ENTRY dsa_code_restore_pointers
269 dsa_code_restore_pointers:
270 #if (CHIP == 710)
271 ; TEMP and DSA are corrupt when we get here, but who cares!
272 MOVE MEMORY 4, dsa_temp_addr_saved_pointer, jump_temp + 4
273 ; HARD CODED : 24 bytes needs to agree with 53c7,8xx.h
274 MOVE MEMORY 24, dsa_temp_addr_saved_residual, dsa_temp_addr_residual
275 CLEAR ACK
276 ; Restore DSA, note we don't care about TEMP
277 MOVE MEMORY 4, saved_dsa, addr_dsa
278 #ifdef DEBUG
279 INT int_debug_restored
280 #endif
281 JUMP jump_temp
282 #else
283 DMODE_MEMORY_TO_NCR
284 MOVE MEMORY 4, dsa_temp_addr_saved_pointer, addr_temp
285 DMODE_MEMORY_TO_MEMORY
286 ; HARD CODED : 24 bytes needs to agree with 53c7,8xx.h
287 MOVE MEMORY 24, dsa_temp_addr_saved_residual, dsa_temp_addr_residual
288 CLEAR ACK
289 #ifdef DEBUG
290 INT int_debug_restored
291 #endif
292 RETURN
293 #endif
295 ABSOLUTE dsa_check_reselect = 0
296 ; dsa_check_reselect determines whether or not the current target and
297 ; lun match the current DSA
298 ENTRY dsa_code_check_reselect
299 dsa_code_check_reselect:
300 #if (CHIP == 710)
301 /* Arrives here with DSA correct */
302 /* Assumes we are always ID 7 */
303 MOVE LCRC TO SFBR ; LCRC has our ID and his ID bits set
304 JUMP REL (wrong_dsa), IF NOT dsa_temp_target, AND MASK 0x80
305 #else
306 MOVE SSID TO SFBR ; SSID contains 3 bit target ID
307 ; FIXME : we need to accommodate bit fielded and binary here for '7xx/'8xx chips
308 JUMP REL (wrong_dsa), IF NOT dsa_temp_target, AND MASK 0xf8
309 #endif
310 ;
311 ; Hack - move to scratch first, since SFBR is not writeable
312 ; via the CPU and hence a MOVE MEMORY instruction.
313 ;
314 DMODE_MEMORY_TO_NCR
315 MOVE MEMORY 1, reselected_identify, addr_scratch
316 DMODE_MEMORY_TO_MEMORY
317 #ifdef BIG_ENDIAN
318 ; BIG ENDIAN ON MVME16x
319 MOVE SCRATCH3 TO SFBR
320 #else
321 MOVE SCRATCH0 TO SFBR
322 #endif
323 ; FIXME : we need to accommodate bit fielded and binary here for '7xx/'8xx chips
324 ; Are you sure about that? richard@sleepie.demon.co.uk
325 JUMP REL (wrong_dsa), IF NOT dsa_temp_lun, AND MASK 0xf8
326 ; Patch the MOVE MEMORY INSTRUCTION such that
327 ; the source address is the address of this dsa's
328 ; next pointer.
329 MOVE MEMORY 4, dsa_temp_addr_next, reselected_ok_patch + 4
330 CALL reselected_ok
331 #if (CHIP == 710)
332 ; Restore DSA following memory moves in reselected_ok
333 ; dsa_temp_sync doesn't really care about DSA, but it has an
334 ; optional debug INT so a valid DSA is a good idea.
335 MOVE MEMORY 4, saved_dsa, addr_dsa
336 #endif
337 CALL dsa_temp_sync
338 ; Release ACK on the IDENTIFY message _after_ we've set the synchronous
339 ; transfer parameters!
340 CLEAR ACK
341 ; Implicitly restore pointers on reselection, so a RETURN
342 ; will transfer control back to the right spot.
343 CALL REL (dsa_code_restore_pointers)
344 RETURN
345 ENTRY dsa_zero
346 dsa_zero:
347 ENTRY dsa_code_template_end
348 dsa_code_template_end:
350 ; Perform sanity check for dsa_fields_start == dsa_code_template_end -
351 ; dsa_zero, puke.
353 ABSOLUTE dsa_fields_start = 0 ; Sanity marker
354 ; pad 48 bytes (fix this RSN)
355 ABSOLUTE dsa_next = 48 ; len 4 Next DSA
356 ; del 4 Previous DSA address
357 ABSOLUTE dsa_cmnd = 56 ; len 4 Scsi_Cmnd * for this thread.
358 ABSOLUTE dsa_select = 60 ; len 4 Device ID, Period, Offset for
359 ; table indirect select
360 ABSOLUTE dsa_msgout = 64 ; len 8 table indirect move parameter for
361 ; select message
362 ABSOLUTE dsa_cmdout = 72 ; len 8 table indirect move parameter for
363 ; command
364 ABSOLUTE dsa_dataout = 80 ; len 4 code pointer for dataout
365 ABSOLUTE dsa_datain = 84 ; len 4 code pointer for datain
366 ABSOLUTE dsa_msgin = 88 ; len 8 table indirect move for msgin
367 ABSOLUTE dsa_status = 96 ; len 8 table indirect move for status byte
368 ABSOLUTE dsa_msgout_other = 104 ; len 8 table indirect for normal message out
369 ; (Synchronous transfer negotiation, etc).
370 ABSOLUTE dsa_end = 112
372 ABSOLUTE schedule = 0 ; Array of JUMP dsa_begin or JUMP (next),
373 ; terminated by a call to JUMP wait_reselect
375 ; Linked lists of DSA structures
376 ABSOLUTE reconnect_dsa_head = 0 ; Link list of DSAs which can reconnect
377 ABSOLUTE addr_reconnect_dsa_head = 0 ; Address of variable containing
378 ; address of reconnect_dsa_head
380 ; These select the source and destination of a MOVE MEMORY instruction
381 ABSOLUTE dmode_memory_to_memory = 0x0
382 ABSOLUTE dmode_memory_to_ncr = 0x0
383 ABSOLUTE dmode_ncr_to_memory = 0x0
385 ABSOLUTE addr_scratch = 0x0
386 ABSOLUTE addr_temp = 0x0
387 #if (CHIP == 710)
388 ABSOLUTE saved_dsa = 0x0
389 ABSOLUTE emulfly = 0x0
390 ABSOLUTE addr_dsa = 0x0
391 #endif
392 #endif /* CHIP != 700 && CHIP != 70066 */
394 ; Interrupts -
395 ; MSB indicates type
396 ; 0 handle error condition
397 ; 1 handle message
398 ; 2 handle normal condition
399 ; 3 debugging interrupt
400 ; 4 testing interrupt
401 ; Next byte indicates specific error
403 ; XXX not yet implemented, I'm not sure if I want to -
404 ; Next byte indicates the routine the error occurred in
405 ; The LSB indicates the specific place the error occurred
407 ABSOLUTE int_err_unexpected_phase = 0x00000000 ; Unexpected phase encountered
408 ABSOLUTE int_err_selected = 0x00010000 ; SELECTED (nee RESELECTED)
409 ABSOLUTE int_err_unexpected_reselect = 0x00020000
410 ABSOLUTE int_err_check_condition = 0x00030000
411 ABSOLUTE int_err_no_phase = 0x00040000
412 ABSOLUTE int_msg_wdtr = 0x01000000 ; WDTR message received
413 ABSOLUTE int_msg_sdtr = 0x01010000 ; SDTR received
414 ABSOLUTE int_msg_1 = 0x01020000 ; single byte special message
415 ; received
417 ABSOLUTE int_norm_select_complete = 0x02000000 ; Select complete, reprogram
418 ; registers.
419 ABSOLUTE int_norm_reselect_complete = 0x02010000 ; Nexus established
420 ABSOLUTE int_norm_command_complete = 0x02020000 ; Command complete
421 ABSOLUTE int_norm_disconnected = 0x02030000 ; Disconnected
422 ABSOLUTE int_norm_aborted =0x02040000 ; Aborted *dsa
423 ABSOLUTE int_norm_reset = 0x02050000 ; Generated BUS reset.
424 ABSOLUTE int_norm_emulateintfly = 0x02060000 ; 53C710 Emulated intfly
425 ABSOLUTE int_debug_break = 0x03000000 ; Break point
426 #ifdef DEBUG
427 ABSOLUTE int_debug_scheduled = 0x03010000 ; new I/O scheduled
428 ABSOLUTE int_debug_idle = 0x03020000 ; scheduler is idle
429 ABSOLUTE int_debug_dsa_loaded = 0x03030000 ; dsa reloaded
430 ABSOLUTE int_debug_reselected = 0x03040000 ; NCR reselected
431 ABSOLUTE int_debug_head = 0x03050000 ; issue head overwritten
432 ABSOLUTE int_debug_disconnected = 0x03060000 ; disconnected
433 ABSOLUTE int_debug_disconnect_msg = 0x03070000 ; got message to disconnect
434 ABSOLUTE int_debug_dsa_schedule = 0x03080000 ; in dsa_schedule
435 ABSOLUTE int_debug_reselect_check = 0x03090000 ; Check for reselection of DSA
436 ABSOLUTE int_debug_reselected_ok = 0x030a0000 ; Reselection accepted
437 #endif
438 ABSOLUTE int_debug_panic = 0x030b0000 ; Panic driver
439 #ifdef DEBUG
440 ABSOLUTE int_debug_saved = 0x030c0000 ; save/restore pointers
441 ABSOLUTE int_debug_restored = 0x030d0000
442 ABSOLUTE int_debug_sync = 0x030e0000 ; Sanity check synchronous
443 ; parameters.
444 ABSOLUTE int_debug_datain = 0x030f0000 ; going into data in phase
445 ; now.
446 ABSOLUTE int_debug_check_dsa = 0x03100000 ; Sanity check DSA against
447 ; SDID.
448 #endif
450 ABSOLUTE int_test_1 = 0x04000000 ; Test 1 complete
451 ABSOLUTE int_test_2 = 0x04010000 ; Test 2 complete
452 ABSOLUTE int_test_3 = 0x04020000 ; Test 3 complete
455 ; These should start with 0x05000000, with low bits incrementing for
456 ; each one.
458 #ifdef EVENTS
459 ABSOLUTE int_EVENT_SELECT = 0
460 ABSOLUTE int_EVENT_DISCONNECT = 0
461 ABSOLUTE int_EVENT_RESELECT = 0
462 ABSOLUTE int_EVENT_COMPLETE = 0
463 ABSOLUTE int_EVENT_IDLE = 0
464 ABSOLUTE int_EVENT_SELECT_FAILED = 0
465 ABSOLUTE int_EVENT_BEFORE_SELECT = 0
466 ABSOLUTE int_EVENT_RESELECT_FAILED = 0
467 #endif
469 ABSOLUTE NCR53c7xx_msg_abort = 0 ; Pointer to abort message
470 ABSOLUTE NCR53c7xx_msg_reject = 0 ; Pointer to reject message
471 ABSOLUTE NCR53c7xx_zero = 0 ; long with zero in it, use for source
472 ABSOLUTE NCR53c7xx_sink = 0 ; long to dump worthless data in
473 ABSOLUTE NOP_insn = 0 ; NOP instruction
475 ; Pointer to message, potentially multi-byte
476 ABSOLUTE msg_buf = 0
478 ; Pointer to holding area for reselection information
479 ABSOLUTE reselected_identify = 0
480 ABSOLUTE reselected_tag = 0
482 ; Request sense command pointer, it's a 6 byte command, should
483 ; be constant for all commands since we always want 16 bytes of
484 ; sense and we don't need to change any fields as we did under
485 ; SCSI-I when we actually cared about the LUN field.
486 ;EXTERNAL NCR53c7xx_sense ; Request sense command
488 #if (CHIP != 700) && (CHIP != 70066)
489 ; dsa_schedule
490 ; PURPOSE : after a DISCONNECT message has been received, and pointers
491 ; saved, insert the current DSA structure at the head of the
492 ; disconnected queue and fall through to the scheduler.
493 ;
494 ; CALLS : OK
495 ;
496 ; INPUTS : dsa - current DSA structure, reconnect_dsa_head - list
497 ; of disconnected commands
498 ;
499 ; MODIFIES : SCRATCH, reconnect_dsa_head
500 ;
501 ; EXITS : always passes control to schedule
503 ENTRY dsa_schedule
504 dsa_schedule:
505 #ifdef DEBUG
506 INT int_debug_dsa_schedule
507 #endif
509 ;
510 ; Calculate the address of the next pointer within the DSA
511 ; structure of the command that is currently disconnecting
512 ;
513 #if (CHIP == 710)
514 ; Read what should be the current DSA from memory - actual DSA
515 ; register is probably corrupt
516 MOVE MEMORY 4, saved_dsa, addr_scratch
517 #else
518 CALL dsa_to_scratch
519 #endif
520 MOVE SCRATCH0 + dsa_next TO SCRATCH0
521 MOVE SCRATCH1 + 0 TO SCRATCH1 WITH CARRY
522 MOVE SCRATCH2 + 0 TO SCRATCH2 WITH CARRY
523 MOVE SCRATCH3 + 0 TO SCRATCH3 WITH CARRY
525 ; Point the next field of this DSA structure at the current disconnected
526 ; list
527 DMODE_NCR_TO_MEMORY
528 MOVE MEMORY 4, addr_scratch, dsa_schedule_insert + 8
529 DMODE_MEMORY_TO_MEMORY
530 dsa_schedule_insert:
531 MOVE MEMORY 4, reconnect_dsa_head, 0
533 ; And update the head pointer.
534 #if (CHIP == 710)
535 ; Read what should be the current DSA from memory - actual DSA
536 ; register is probably corrupt
537 MOVE MEMORY 4, saved_dsa, addr_scratch
538 #else
539 CALL dsa_to_scratch
540 #endif
541 DMODE_NCR_TO_MEMORY
542 MOVE MEMORY 4, addr_scratch, reconnect_dsa_head
543 DMODE_MEMORY_TO_MEMORY
544 /* Temporarily, see what happens. */
545 #ifndef ORIGINAL
546 #if (CHIP != 710)
547 MOVE SCNTL2 & 0x7f TO SCNTL2
548 #endif
549 CLEAR ACK
550 #endif
551 #if (CHIP == 710)
552 ; Time to correct DSA following memory move
553 MOVE MEMORY 4, saved_dsa, addr_dsa
554 #endif
555 WAIT DISCONNECT
556 #ifdef EVENTS
557 INT int_EVENT_DISCONNECT;
558 #endif
559 #ifdef DEBUG
560 INT int_debug_disconnected
561 #endif
562 JUMP schedule
563 #endif
565 ;
566 ; select
567 ;
568 ; PURPOSE : establish a nexus for the SCSI command referenced by DSA.
569 ; On success, the current DSA structure is removed from the issue
570 ; queue. Usually, this is entered as a fall-through from schedule,
571 ; although the contingent allegiance handling code will write
572 ; the select entry address to the DSP to restart a command as a
573 ; REQUEST SENSE. A message is sent (usually IDENTIFY, although
574 ; additional SDTR or WDTR messages may be sent). COMMAND OUT
575 ; is handled.
576 ;
577 ; INPUTS : DSA - SCSI command, issue_dsa_head
578 ;
579 ; CALLS : NOT OK
580 ;
581 ; MODIFIES : SCRATCH, issue_dsa_head
582 ;
583 ; EXITS : on reselection or selection, go to select_failed
584 ; otherwise, RETURN so control is passed back to
585 ; dsa_begin.
586 ;
588 ENTRY select
589 select:
591 #ifdef EVENTS
592 INT int_EVENT_BEFORE_SELECT
593 #endif
595 #ifdef DEBUG
596 INT int_debug_scheduled
597 #endif
598 CLEAR TARGET
600 ; XXX
601 ;
602 ; In effect, SELECTION operations are backgrounded, with execution
603 ; continuing until code which waits for REQ or a fatal interrupt is
604 ; encountered.
605 ;
606 ; So, for more performance, we could overlap the code which removes
607 ; the command from the NCRs issue queue with the selection, but
608 ; at this point I don't want to deal with the error recovery.
609 ;
611 #if (CHIP != 700) && (CHIP != 70066)
612 #if (CHIP == 710)
613 ; Enable selection timer
614 #ifdef NO_SELECTION_TIMEOUT
615 MOVE CTEST7 & 0xff TO CTEST7
616 #else
617 MOVE CTEST7 & 0xef TO CTEST7
618 #endif
619 #endif
620 SELECT ATN FROM dsa_select, select_failed
621 JUMP select_msgout, WHEN MSG_OUT
622 ENTRY select_msgout
623 select_msgout:
624 #if (CHIP == 710)
625 ; Disable selection timer
626 MOVE CTEST7 | 0x10 TO CTEST7
627 #endif
628 MOVE FROM dsa_msgout, WHEN MSG_OUT
629 #else
630 ENTRY select_msgout
631 SELECT ATN 0, select_failed
632 select_msgout:
633 MOVE 0, 0, WHEN MSGOUT
634 #endif
636 #ifdef EVENTS
637 INT int_EVENT_SELECT
638 #endif
639 RETURN
641 ;
642 ; select_done
643 ;
644 ; PURPOSE: continue on to normal data transfer; called as the exit
645 ; point from dsa_begin.
646 ;
647 ; INPUTS: dsa
648 ;
649 ; CALLS: OK
650 ;
651 ;
653 select_done:
654 #if (CHIP == 710)
655 ; NOTE DSA is corrupt when we arrive here!
656 MOVE MEMORY 4, saved_dsa, addr_dsa
657 #endif
659 #ifdef DEBUG
660 ENTRY select_check_dsa
661 select_check_dsa:
662 INT int_debug_check_dsa
663 #endif
665 ; After a successful selection, we should get either a CMD phase or
666 ; some transfer request negotiation message.
668 JUMP cmdout, WHEN CMD
669 INT int_err_unexpected_phase, WHEN NOT MSG_IN
671 select_msg_in:
672 CALL msg_in, WHEN MSG_IN
673 JUMP select_msg_in, WHEN MSG_IN
675 cmdout:
676 INT int_err_unexpected_phase, WHEN NOT CMD
677 #if (CHIP == 700)
678 INT int_norm_selected
679 #endif
680 ENTRY cmdout_cmdout
681 cmdout_cmdout:
682 #if (CHIP != 700) && (CHIP != 70066)
683 MOVE FROM dsa_cmdout, WHEN CMD
684 #else
685 MOVE 0, 0, WHEN CMD
686 #endif /* (CHIP != 700) && (CHIP != 70066) */
688 ;
689 ; data_transfer
690 ; other_out
691 ; other_in
692 ; other_transfer
693 ;
694 ; PURPOSE : handle the main data transfer for a SCSI command in
695 ; several parts. In the first part, data_transfer, DATA_IN
696 ; and DATA_OUT phases are allowed, with the user provided
697 ; code (usually dynamically generated based on the scatter/gather
698 ; list associated with a SCSI command) called to handle these
699 ; phases.
700 ;
701 ; After control has passed to one of the user provided
702 ; DATA_IN or DATA_OUT routines, back calls are made to
703 ; other_transfer_in or other_transfer_out to handle non-DATA IN
704 ; and DATA OUT phases respectively, with the state of the active
705 ; data pointer being preserved in TEMP.
706 ;
707 ; On completion, the user code passes control to other_transfer
708 ; which causes DATA_IN and DATA_OUT to result in unexpected_phase
709 ; interrupts so that data overruns may be trapped.
710 ;
711 ; INPUTS : DSA - SCSI command
712 ;
713 ; CALLS : OK in data_transfer_start, not ok in other_out and other_in, ok in
714 ; other_transfer
715 ;
716 ; MODIFIES : SCRATCH
717 ;
718 ; EXITS : if STATUS IN is detected, signifying command completion,
719 ; the NCR jumps to command_complete. If MSG IN occurs, a
720 ; CALL is made to msg_in. Otherwise, other_transfer runs in
721 ; an infinite loop.
722 ;
724 ENTRY data_transfer
725 data_transfer:
726 JUMP cmdout_cmdout, WHEN CMD
727 CALL msg_in, WHEN MSG_IN
728 INT int_err_unexpected_phase, WHEN MSG_OUT
729 JUMP do_dataout, WHEN DATA_OUT
730 JUMP do_datain, WHEN DATA_IN
731 JUMP command_complete, WHEN STATUS
732 JUMP data_transfer
733 ENTRY end_data_transfer
734 end_data_transfer:
736 ;
737 ; FIXME: On NCR53c700 and NCR53c700-66 chips, do_dataout/do_datain
738 ; should be fixed up whenever the nexus changes so it can point to the
739 ; correct routine for that command.
740 ;
742 #if (CHIP != 700) && (CHIP != 70066)
743 ; Nasty jump to dsa->dataout
744 do_dataout:
745 #if (CHIP == 710)
746 MOVE MEMORY 4, saved_dsa, addr_scratch
747 #else
748 CALL dsa_to_scratch
749 #endif
750 MOVE SCRATCH0 + dsa_dataout TO SCRATCH0
751 MOVE SCRATCH1 + 0 TO SCRATCH1 WITH CARRY
752 MOVE SCRATCH2 + 0 TO SCRATCH2 WITH CARRY
753 MOVE SCRATCH3 + 0 TO SCRATCH3 WITH CARRY
754 DMODE_NCR_TO_MEMORY
755 MOVE MEMORY 4, addr_scratch, dataout_to_jump + 4
756 DMODE_MEMORY_TO_MEMORY
757 dataout_to_jump:
758 MOVE MEMORY 4, 0, dataout_jump + 4
759 #if (CHIP == 710)
760 ; Time to correct DSA following memory move
761 MOVE MEMORY 4, saved_dsa, addr_dsa
762 #endif
763 dataout_jump:
764 JUMP 0
766 ; Nasty jump to dsa->dsain
767 do_datain:
768 #if (CHIP == 710)
769 MOVE MEMORY 4, saved_dsa, addr_scratch
770 #else
771 CALL dsa_to_scratch
772 #endif
773 MOVE SCRATCH0 + dsa_datain TO SCRATCH0
774 MOVE SCRATCH1 + 0 TO SCRATCH1 WITH CARRY
775 MOVE SCRATCH2 + 0 TO SCRATCH2 WITH CARRY
776 MOVE SCRATCH3 + 0 TO SCRATCH3 WITH CARRY
777 DMODE_NCR_TO_MEMORY
778 MOVE MEMORY 4, addr_scratch, datain_to_jump + 4
779 DMODE_MEMORY_TO_MEMORY
780 ENTRY datain_to_jump
781 datain_to_jump:
782 MOVE MEMORY 4, 0, datain_jump + 4
783 #if (CHIP == 710)
784 ; Time to correct DSA following memory move
785 MOVE MEMORY 4, saved_dsa, addr_dsa
786 #endif
787 #ifdef DEBUG
788 INT int_debug_datain
789 #endif
790 datain_jump:
791 JUMP 0
792 #endif /* (CHIP != 700) && (CHIP != 70066) */
795 ; Note that other_out and other_in loop until a non-data phase
796 ; is discovered, so we only execute return statements when we
797 ; can go on to the next data phase block move statement.
799 ENTRY other_out
800 other_out:
801 #if 0
802 INT 0x03ffdead
803 #endif
804 INT int_err_unexpected_phase, WHEN CMD
805 JUMP msg_in_restart, WHEN MSG_IN
806 INT int_err_unexpected_phase, WHEN MSG_OUT
807 INT int_err_unexpected_phase, WHEN DATA_IN
808 JUMP command_complete, WHEN STATUS
809 JUMP other_out, WHEN NOT DATA_OUT
810 #if (CHIP == 710)
811 ; TEMP should be OK, as we got here from a call in the user dataout code.
812 #endif
813 RETURN
815 ENTRY other_in
816 other_in:
817 #if 0
818 INT 0x03ffdead
819 #endif
820 INT int_err_unexpected_phase, WHEN CMD
821 JUMP msg_in_restart, WHEN MSG_IN
822 INT int_err_unexpected_phase, WHEN MSG_OUT
823 INT int_err_unexpected_phase, WHEN DATA_OUT
824 JUMP command_complete, WHEN STATUS
825 JUMP other_in, WHEN NOT DATA_IN
826 #if (CHIP == 710)
827 ; TEMP should be OK, as we got here from a call in the user datain code.
828 #endif
829 RETURN
832 ENTRY other_transfer
833 other_transfer:
834 INT int_err_unexpected_phase, WHEN CMD
835 CALL msg_in, WHEN MSG_IN
836 INT int_err_unexpected_phase, WHEN MSG_OUT
837 INT int_err_unexpected_phase, WHEN DATA_OUT
838 INT int_err_unexpected_phase, WHEN DATA_IN
839 JUMP command_complete, WHEN STATUS
840 JUMP other_transfer
842 ;
843 ; msg_in_restart
844 ; msg_in
845 ; munge_msg
846 ;
847 ; PURPOSE : process messages from a target. msg_in is called when the
848 ; caller hasn't read the first byte of the message. munge_message
849 ; is called when the caller has read the first byte of the message,
850 ; and left it in SFBR. msg_in_restart is called when the caller
851 ; hasn't read the first byte of the message, and wishes RETURN
852 ; to transfer control back to the address of the conditional
853 ; CALL instruction rather than to the instruction after it.
854 ;
855 ; Various int_* interrupts are generated when the host system
856 ; needs to intervene, as is the case with SDTR, WDTR, and
857 ; INITIATE RECOVERY messages.
858 ;
859 ; When the host system handles one of these interrupts,
860 ; it can respond by reentering at reject_message,
861 ; which rejects the message and returns control to
862 ; the caller of msg_in or munge_msg, accept_message
863 ; which clears ACK and returns control, or reply_message
864 ; which sends the message pointed to by the DSA
865 ; msgout_other table indirect field.
866 ;
867 ; DISCONNECT messages are handled by moving the command
868 ; to the reconnect_dsa_queue.
869 #if (CHIP == 710)
870 ; NOTE: DSA should be valid when we get here - we cannot save both it
871 ; and TEMP in this routine.
872 #endif
873 ;
874 ; INPUTS : DSA - SCSI COMMAND, SFBR - first byte of message (munge_msg
875 ; only)
876 ;
877 ; CALLS : NO. The TEMP register isn't backed up to allow nested calls.
878 ;
879 ; MODIFIES : SCRATCH, DSA on DISCONNECT
880 ;
881 ; EXITS : On receipt of SAVE DATA POINTER, RESTORE POINTERS,
882 ; and normal return from message handlers running under
883 ; Linux, control is returned to the caller. Receipt
884 ; of DISCONNECT messages pass control to dsa_schedule.
885 ;
886 ENTRY msg_in_restart
887 msg_in_restart:
888 ; XXX - hackish
889 ;
890 ; Since it's easier to debug changes to the statically
891 ; compiled code, rather than the dynamically generated
892 ; stuff, such as
893 ;
894 ; MOVE x, y, WHEN data_phase
895 ; CALL other_z, WHEN NOT data_phase
896 ; MOVE x, y, WHEN data_phase
897 ;
898 ; I'd like to have certain routines (notably the message handler)
899 ; restart on the conditional call rather than the next instruction.
900 ;
901 ; So, subtract 8 from the return address
903 MOVE TEMP0 + 0xf8 TO TEMP0
904 MOVE TEMP1 + 0xff TO TEMP1 WITH CARRY
905 MOVE TEMP2 + 0xff TO TEMP2 WITH CARRY
906 MOVE TEMP3 + 0xff TO TEMP3 WITH CARRY
908 ENTRY msg_in
909 msg_in:
910 MOVE 1, msg_buf, WHEN MSG_IN
912 munge_msg:
913 JUMP munge_extended, IF 0x01 ; EXTENDED MESSAGE
914 JUMP munge_2, IF 0x20, AND MASK 0xdf ; two byte message
915 ;
916 ; XXX - I've seen a handful of broken SCSI devices which fail to issue
917 ; a SAVE POINTERS message before disconnecting in the middle of
918 ; a transfer, assuming that the DATA POINTER will be implicitly
919 ; restored.
920 ;
921 ; Historically, I've often done an implicit save when the DISCONNECT
922 ; message is processed. We may want to consider having the option of
923 ; doing that here.
924 ;
925 JUMP munge_save_data_pointer, IF 0x02 ; SAVE DATA POINTER
926 JUMP munge_restore_pointers, IF 0x03 ; RESTORE POINTERS
927 JUMP munge_disconnect, IF 0x04 ; DISCONNECT
928 INT int_msg_1, IF 0x07 ; MESSAGE REJECT
929 INT int_msg_1, IF 0x0f ; INITIATE RECOVERY
930 #ifdef EVENTS
931 INT int_EVENT_SELECT_FAILED
932 #endif
933 JUMP reject_message
935 munge_2:
936 JUMP reject_message
937 ;
938 ; The SCSI standard allows targets to recover from transient
939 ; error conditions by backing up the data pointer with a
940 ; RESTORE POINTERS message.
941 ;
942 ; So, we must save and restore the _residual_ code as well as
943 ; the current instruction pointer. Because of this messiness,
944 ; it is simpler to put dynamic code in the dsa for this and to
945 ; just do a simple jump down there.
946 ;
948 munge_save_data_pointer:
949 #if (CHIP == 710)
950 ; We have something in TEMP here, so first we must save that
951 MOVE TEMP0 TO SFBR
952 MOVE SFBR TO SCRATCH0
953 MOVE TEMP1 TO SFBR
954 MOVE SFBR TO SCRATCH1
955 MOVE TEMP2 TO SFBR
956 MOVE SFBR TO SCRATCH2
957 MOVE TEMP3 TO SFBR
958 MOVE SFBR TO SCRATCH3
959 MOVE MEMORY 4, addr_scratch, jump_temp + 4
960 ; Now restore DSA
961 MOVE MEMORY 4, saved_dsa, addr_dsa
962 #endif
963 MOVE DSA0 + dsa_save_data_pointer TO SFBR
964 MOVE SFBR TO SCRATCH0
965 MOVE DSA1 + 0xff TO SFBR WITH CARRY
966 MOVE SFBR TO SCRATCH1
967 MOVE DSA2 + 0xff TO SFBR WITH CARRY
968 MOVE SFBR TO SCRATCH2
969 MOVE DSA3 + 0xff TO SFBR WITH CARRY
970 MOVE SFBR TO SCRATCH3
972 DMODE_NCR_TO_MEMORY
973 MOVE MEMORY 4, addr_scratch, jump_dsa_save + 4
974 DMODE_MEMORY_TO_MEMORY
975 jump_dsa_save:
976 JUMP 0
978 munge_restore_pointers:
979 #if (CHIP == 710)
980 ; The code at dsa_restore_pointers will RETURN, but we don't care
981 ; about TEMP here, as it will overwrite it anyway.
982 #endif
983 MOVE DSA0 + dsa_restore_pointers TO SFBR
984 MOVE SFBR TO SCRATCH0
985 MOVE DSA1 + 0xff TO SFBR WITH CARRY
986 MOVE SFBR TO SCRATCH1
987 MOVE DSA2 + 0xff TO SFBR WITH CARRY
988 MOVE SFBR TO SCRATCH2
989 MOVE DSA3 + 0xff TO SFBR WITH CARRY
990 MOVE SFBR TO SCRATCH3
992 DMODE_NCR_TO_MEMORY
993 MOVE MEMORY 4, addr_scratch, jump_dsa_restore + 4
994 DMODE_MEMORY_TO_MEMORY
995 jump_dsa_restore:
996 JUMP 0
999 munge_disconnect:
1000 #ifdef DEBUG
1001 INT int_debug_disconnect_msg
1002 #endif
1004 /*
1005 * Before, we overlapped processing with waiting for disconnect, but
1006 * debugging was beginning to appear messy. Temporarily move things
1007 * to just before the WAIT DISCONNECT.
1008 */
1010 #ifdef ORIGINAL
1011 #if (CHIP == 710)
1012 ; Following clears Unexpected Disconnect bit. What do we do?
1013 #else
1014 MOVE SCNTL2 & 0x7f TO SCNTL2
1015 #endif
1016 CLEAR ACK
1017 #endif
1019 #if (CHIP != 700) && (CHIP != 70066)
1020 JUMP dsa_schedule
1021 #else
1022 WAIT DISCONNECT
1023 INT int_norm_disconnected
1024 #endif
1026 munge_extended:
1027 CLEAR ACK
1028 INT int_err_unexpected_phase, WHEN NOT MSG_IN
1029 MOVE 1, msg_buf + 1, WHEN MSG_IN
1030 JUMP munge_extended_2, IF 0x02
1031 JUMP munge_extended_3, IF 0x03
1032 JUMP reject_message
1034 munge_extended_2:
1035 CLEAR ACK
1036 MOVE 1, msg_buf + 2, WHEN MSG_IN
1037 JUMP reject_message, IF NOT 0x02 ; Must be WDTR
1038 CLEAR ACK
1039 MOVE 1, msg_buf + 3, WHEN MSG_IN
1040 INT int_msg_wdtr
1042 munge_extended_3:
1043 CLEAR ACK
1044 MOVE 1, msg_buf + 2, WHEN MSG_IN
1045 JUMP reject_message, IF NOT 0x01 ; Must be SDTR
1046 CLEAR ACK
1047 MOVE 2, msg_buf + 3, WHEN MSG_IN
1048 INT int_msg_sdtr
1050 ENTRY reject_message
1051 reject_message:
1052 SET ATN
1053 CLEAR ACK
1054 MOVE 1, NCR53c7xx_msg_reject, WHEN MSG_OUT
1055 RETURN
1057 ENTRY accept_message
1058 accept_message:
1059 CLEAR ATN
1060 CLEAR ACK
1061 RETURN
1063 ENTRY respond_message
1064 respond_message:
1065 SET ATN
1066 CLEAR ACK
1067 MOVE FROM dsa_msgout_other, WHEN MSG_OUT
1068 RETURN
1070 ;
1071 ; command_complete
1072 ;
1073 ; PURPOSE : handle command termination when STATUS IN is detected by reading
1074 ; a status byte followed by a command termination message.
1075 ;
1076 ; Normal termination results in an INTFLY instruction, and
1077 ; the host system can pick out which command terminated by
1078 ; examining the MESSAGE and STATUS buffers of all currently
1079 ; executing commands;
1080 ;
1081 ; Abnormal (CHECK_CONDITION) termination results in an
1082 ; int_err_check_condition interrupt so that a REQUEST SENSE
1083 ; command can be issued out-of-order so that no other command
1084 ; clears the contingent allegiance condition.
1085 ;
1086 ;
1087 ; INPUTS : DSA - command
1088 ;
1089 ; CALLS : OK
1090 ;
1091 ; EXITS : On successful termination, control is passed to schedule.
1092 ; On abnormal termination, the user will usually modify the
1093 ; DSA fields and corresponding buffers and return control
1094 ; to select.
1095 ;
1097 ENTRY command_complete
1098 command_complete:
1099 MOVE FROM dsa_status, WHEN STATUS
1100 #if (CHIP != 700) && (CHIP != 70066)
1101 MOVE SFBR TO SCRATCH0 ; Save status
1102 #endif /* (CHIP != 700) && (CHIP != 70066) */
1103 ENTRY command_complete_msgin
1104 command_complete_msgin:
1105 MOVE FROM dsa_msgin, WHEN MSG_IN
1106 ; Indicate that we should be expecting a disconnect
1107 #if (CHIP != 710)
1108 MOVE SCNTL2 & 0x7f TO SCNTL2
1109 #else
1110 ; Above code cleared the Unexpected Disconnect bit, what do we do?
1111 #endif
1112 CLEAR ACK
1113 #if (CHIP != 700) && (CHIP != 70066)
1114 WAIT DISCONNECT
1116 ;
1117 ; The SCSI specification states that when a UNIT ATTENTION condition
1118 ; is pending, as indicated by a CHECK CONDITION status message,
1119 ; the target shall revert to asynchronous transfers. Since
1120 ; synchronous transfers parameters are maintained on a per INITIATOR/TARGET
1121 ; basis, and returning control to our scheduler could work on a command
1122 ; running on another lun on that target using the old parameters, we must
1123 ; interrupt the host processor to get them changed, or change them ourselves.
1124 ;
1125 ; Once SCSI-II tagged queueing is implemented, things will be even more
1126 ; hairy, since contingent allegiance conditions exist on a per-target/lun
1127 ; basis, and issuing a new command with a different tag would clear it.
1128 ; In these cases, we must interrupt the host processor to get a request
1129 ; added to the HEAD of the queue with the request sense command, or we
1130 ; must automatically issue the request sense command.
1132 #if 0
1133 MOVE SCRATCH0 TO SFBR
1134 JUMP command_failed, IF 0x02
1135 #endif
1136 #if (CHIP == 710)
1137 #if defined(MVME16x_INTFLY)
1138 ; For MVME16x (ie CHIP=710) we will force an INTFLY by triggering a software
1139 ; interrupt (SW7). We can use SCRATCH, as we are about to jump to
1140 ; schedule, which corrupts it anyway. Will probably remove this later,
1141 ; but want to check performance effects first.
1143 #define INTFLY_ADDR 0xfff40070
1145 MOVE 0 TO SCRATCH0
1146 MOVE 0x80 TO SCRATCH1
1147 MOVE 0 TO SCRATCH2
1148 MOVE 0 TO SCRATCH3
1149 MOVE MEMORY 4, addr_scratch, INTFLY_ADDR
1150 #else
1151 INT int_norm_emulateintfly
1152 #endif
1153 #else
1154 INTFLY
1155 #endif
1156 #endif /* (CHIP != 700) && (CHIP != 70066) */
1157 #if (CHIP == 710)
1158 ; Time to correct DSA following memory move
1159 MOVE MEMORY 4, saved_dsa, addr_dsa
1160 #endif
1161 #ifdef EVENTS
1162 INT int_EVENT_COMPLETE
1163 #endif
1164 #if (CHIP != 700) && (CHIP != 70066)
1165 JUMP schedule
1166 command_failed:
1167 INT int_err_check_condition
1168 #else
1169 INT int_norm_command_complete
1170 #endif
1172 ;
1173 ; wait_reselect
1174 ;
1175 ; PURPOSE : This is essentially the idle routine, where control lands
1176 ; when there are no new processes to schedule. wait_reselect
1177 ; waits for reselection, selection, and new commands.
1178 ;
1179 ; When a successful reselection occurs, with the aid
1180 ; of fixed up code in each DSA, wait_reselect walks the
1181 ; reconnect_dsa_queue, asking each dsa if the target ID
1182 ; and LUN match its.
1183 ;
1184 ; If a match is found, a call is made back to reselected_ok,
1185 ; which through the miracles of self modifying code, extracts
1186 ; the found DSA from the reconnect_dsa_queue and then
1187 ; returns control to the DSAs thread of execution.
1188 ;
1189 ; INPUTS : NONE
1190 ;
1191 ; CALLS : OK
1192 ;
1193 ; MODIFIES : DSA,
1194 ;
1195 ; EXITS : On successful reselection, control is returned to the
1196 ; DSA which called reselected_ok. If the WAIT RESELECT
1197 ; was interrupted by a new commands arrival signaled by
1198 ; SIG_P, control is passed to schedule. If the NCR is
1199 ; selected, the host system is interrupted with an
1200 ; int_err_selected which is usually responded to by
1201 ; setting DSP to the target_abort address.
1203 ENTRY wait_reselect
1204 wait_reselect:
1205 #ifdef EVENTS
1206 int int_EVENT_IDLE
1207 #endif
1208 #ifdef DEBUG
1209 int int_debug_idle
1210 #endif
1211 WAIT RESELECT wait_reselect_failed
1213 reselected:
1214 #ifdef EVENTS
1215 int int_EVENT_RESELECT
1216 #endif
1217 CLEAR TARGET
1218 DMODE_MEMORY_TO_MEMORY
1219 ; Read all data needed to reestablish the nexus -
1220 MOVE 1, reselected_identify, WHEN MSG_IN
1221 ; We used to CLEAR ACK here.
1222 #if (CHIP != 700) && (CHIP != 70066)
1223 #ifdef DEBUG
1224 int int_debug_reselected
1225 #endif
1227 ; Point DSA at the current head of the disconnected queue.
1228 DMODE_MEMORY_TO_NCR
1229 MOVE MEMORY 4, reconnect_dsa_head, addr_scratch
1230 DMODE_MEMORY_TO_MEMORY
1231 #if (CHIP == 710)
1232 MOVE MEMORY 4, addr_scratch, saved_dsa
1233 #else
1234 CALL scratch_to_dsa
1235 #endif
1237 ; Fix the update-next pointer so that the reconnect_dsa_head
1238 ; pointer is the one that will be updated if this DSA is a hit
1239 ; and we remove it from the queue.
1241 MOVE MEMORY 4, addr_reconnect_dsa_head, reselected_ok_patch + 8
1242 #if (CHIP == 710)
1243 ; Time to correct DSA following memory move
1244 MOVE MEMORY 4, saved_dsa, addr_dsa
1245 #endif
1247 ENTRY reselected_check_next
1248 reselected_check_next:
1249 #ifdef DEBUG
1250 INT int_debug_reselect_check
1251 #endif
1252 ; Check for a NULL pointer.
1253 MOVE DSA0 TO SFBR
1254 JUMP reselected_not_end, IF NOT 0
1255 MOVE DSA1 TO SFBR
1256 JUMP reselected_not_end, IF NOT 0
1257 MOVE DSA2 TO SFBR
1258 JUMP reselected_not_end, IF NOT 0
1259 MOVE DSA3 TO SFBR
1260 JUMP reselected_not_end, IF NOT 0
1261 INT int_err_unexpected_reselect
1263 reselected_not_end:
1264 ;
1265 ; XXX the ALU is only eight bits wide, and the assembler
1266 ; wont do the dirt work for us. As long as dsa_check_reselect
1267 ; is negative, we need to sign extend with 1 bits to the full
1268 ; 32 bit width of the address.
1269 ;
1270 ; A potential work around would be to have a known alignment
1271 ; of the DSA structure such that the base address plus
1272 ; dsa_check_reselect doesn't require carrying from bytes
1273 ; higher than the LSB.
1274 ;
1276 MOVE DSA0 TO SFBR
1277 MOVE SFBR + dsa_check_reselect TO SCRATCH0
1278 MOVE DSA1 TO SFBR
1279 MOVE SFBR + 0xff TO SCRATCH1 WITH CARRY
1280 MOVE DSA2 TO SFBR
1281 MOVE SFBR + 0xff TO SCRATCH2 WITH CARRY
1282 MOVE DSA3 TO SFBR
1283 MOVE SFBR + 0xff TO SCRATCH3 WITH CARRY
1285 DMODE_NCR_TO_MEMORY
1286 MOVE MEMORY 4, addr_scratch, reselected_check + 4
1287 DMODE_MEMORY_TO_MEMORY
1288 #if (CHIP == 710)
1289 ; Time to correct DSA following memory move
1290 MOVE MEMORY 4, saved_dsa, addr_dsa
1291 #endif
1292 reselected_check:
1293 JUMP 0
1296 ;
1297 ;
1298 #if (CHIP == 710)
1299 ; We have problems here - the memory move corrupts TEMP and DSA. This
1300 ; routine is called from DSA code, and patched from many places. Scratch
1301 ; is probably free when it is called.
1302 ; We have to:
1303 ; copy temp to scratch, one byte at a time
1304 ; write scratch to patch a jump in place of the return
1305 ; do the move memory
1306 ; jump to the patched in return address
1307 ; DSA is corrupt when we get here, and can be left corrupt
1309 ENTRY reselected_ok
1310 reselected_ok:
1311 MOVE TEMP0 TO SFBR
1312 MOVE SFBR TO SCRATCH0
1313 MOVE TEMP1 TO SFBR
1314 MOVE SFBR TO SCRATCH1
1315 MOVE TEMP2 TO SFBR
1316 MOVE SFBR TO SCRATCH2
1317 MOVE TEMP3 TO SFBR
1318 MOVE SFBR TO SCRATCH3
1319 MOVE MEMORY 4, addr_scratch, reselected_ok_jump + 4
1320 reselected_ok_patch:
1321 MOVE MEMORY 4, 0, 0
1322 reselected_ok_jump:
1323 JUMP 0
1324 #else
1325 ENTRY reselected_ok
1326 reselected_ok:
1327 reselected_ok_patch:
1328 MOVE MEMORY 4, 0, 0 ; Patched : first word
1329 ; is address of
1330 ; successful dsa_next
1331 ; Second word is last
1332 ; unsuccessful dsa_next,
1333 ; starting with
1334 ; dsa_reconnect_head
1335 ; We used to CLEAR ACK here.
1336 #ifdef DEBUG
1337 INT int_debug_reselected_ok
1338 #endif
1339 #ifdef DEBUG
1340 INT int_debug_check_dsa
1341 #endif
1342 RETURN ; Return control to where
1343 #endif
1344 #else
1345 INT int_norm_reselected
1346 #endif /* (CHIP != 700) && (CHIP != 70066) */
1348 selected:
1349 INT int_err_selected;
1351 ;
1352 ; A select or reselect failure can be caused by one of two conditions :
1353 ; 1. SIG_P was set. This will be the case if the user has written
1354 ; a new value to a previously NULL head of the issue queue.
1355 ;
1356 ; 2. The NCR53c810 was selected or reselected by another device.
1357 ;
1358 ; 3. The bus was already busy since we were selected or reselected
1359 ; before starting the command.
1361 wait_reselect_failed:
1362 #ifdef EVENTS
1363 INT int_EVENT_RESELECT_FAILED
1364 #endif
1365 ; Check selected bit.
1366 #if (CHIP == 710)
1367 ; Must work out how to tell if we are selected....
1368 #else
1369 MOVE SIST0 & 0x20 TO SFBR
1370 JUMP selected, IF 0x20
1371 #endif
1372 ; Reading CTEST2 clears the SIG_P bit in the ISTAT register.
1373 MOVE CTEST2 & 0x40 TO SFBR
1374 JUMP schedule, IF 0x40
1375 ; Check connected bit.
1376 ; FIXME: this needs to change if we support target mode
1377 MOVE ISTAT & 0x08 TO SFBR
1378 JUMP reselected, IF 0x08
1379 ; FIXME : Something bogus happened, and we shouldn't fail silently.
1380 #if 0
1381 JUMP schedule
1382 #else
1383 INT int_debug_panic
1384 #endif
1387 select_failed:
1388 #if (CHIP == 710)
1389 ; Disable selection timer
1390 MOVE CTEST7 | 0x10 TO CTEST7
1391 #endif
1392 #ifdef EVENTS
1393 int int_EVENT_SELECT_FAILED
1394 #endif
1395 ; Otherwise, mask the selected and reselected bits off SIST0
1396 #if (CHIP ==710)
1397 ; Let's assume we don't get selected for now
1398 MOVE SSTAT0 & 0x10 TO SFBR
1399 #else
1400 MOVE SIST0 & 0x30 TO SFBR
1401 JUMP selected, IF 0x20
1402 #endif
1403 JUMP reselected, IF 0x10
1404 ; If SIGP is set, the user just gave us another command, and
1405 ; we should restart or return to the scheduler.
1406 ; Reading CTEST2 clears the SIG_P bit in the ISTAT register.
1407 MOVE CTEST2 & 0x40 TO SFBR
1408 JUMP select, IF 0x40
1409 ; Check connected bit.
1410 ; FIXME: this needs to change if we support target mode
1411 ; FIXME: is this really necessary?
1412 MOVE ISTAT & 0x08 TO SFBR
1413 JUMP reselected, IF 0x08
1414 ; FIXME : Something bogus happened, and we shouldn't fail silently.
1415 #if 0
1416 JUMP schedule
1417 #else
1418 INT int_debug_panic
1419 #endif
1421 ;
1422 ; test_1
1423 ; test_2
1424 ;
1425 ; PURPOSE : run some verification tests on the NCR. test_1
1426 ; copies test_src to test_dest and interrupts the host
1427 ; processor, testing for cache coherency and interrupt
1428 ; problems in the processes.
1429 ;
1430 ; test_2 runs a command with offsets relative to the
1431 ; DSA on entry, and is useful for miscellaneous experimentation.
1432 ;
1434 ; Verify that interrupts are working correctly and that we don't
1435 ; have a cache invalidation problem.
1437 ABSOLUTE test_src = 0, test_dest = 0
1438 ENTRY test_1
1439 test_1:
1440 MOVE MEMORY 4, test_src, test_dest
1441 INT int_test_1
1443 ;
1444 ; Run arbitrary commands, with test code establishing a DSA
1445 ;
1447 ENTRY test_2
1448 test_2:
1449 CLEAR TARGET
1450 #if (CHIP == 710)
1451 ; Enable selection timer
1452 #ifdef NO_SELECTION_TIMEOUT
1453 MOVE CTEST7 & 0xff TO CTEST7
1454 #else
1455 MOVE CTEST7 & 0xef TO CTEST7
1456 #endif
1457 #endif
1458 SELECT ATN FROM 0, test_2_fail
1459 JUMP test_2_msgout, WHEN MSG_OUT
1460 ENTRY test_2_msgout
1461 test_2_msgout:
1462 #if (CHIP == 710)
1463 ; Disable selection timer
1464 MOVE CTEST7 | 0x10 TO CTEST7
1465 #endif
1466 MOVE FROM 8, WHEN MSG_OUT
1467 MOVE FROM 16, WHEN CMD
1468 MOVE FROM 24, WHEN DATA_IN
1469 MOVE FROM 32, WHEN STATUS
1470 MOVE FROM 40, WHEN MSG_IN
1471 #if (CHIP != 710)
1472 MOVE SCNTL2 & 0x7f TO SCNTL2
1473 #endif
1474 CLEAR ACK
1475 WAIT DISCONNECT
1476 test_2_fail:
1477 #if (CHIP == 710)
1478 ; Disable selection timer
1479 MOVE CTEST7 | 0x10 TO CTEST7
1480 #endif
1481 INT int_test_2
1483 ENTRY debug_break
1484 debug_break:
1485 INT int_debug_break
1487 ;
1488 ; initiator_abort
1489 ; target_abort
1490 ;
1491 ; PURPOSE : Abort the currently established nexus from with initiator
1492 ; or target mode.
1493 ;
1494 ;
1496 ENTRY target_abort
1497 target_abort:
1498 SET TARGET
1499 DISCONNECT
1500 CLEAR TARGET
1501 JUMP schedule
1503 ENTRY initiator_abort
1504 initiator_abort:
1505 SET ATN
1506 ;
1507 ; The SCSI-I specification says that targets may go into MSG out at
1508 ; their leisure upon receipt of the ATN single. On all versions of the
1509 ; specification, we can't change phases until REQ transitions true->false,
1510 ; so we need to sink/source one byte of data to allow the transition.
1511 ;
1512 ; For the sake of safety, we'll only source one byte of data in all
1513 ; cases, but to accommodate the SCSI-I dain bramage, we'll sink an
1514 ; arbitrary number of bytes.
1515 JUMP spew_cmd, WHEN CMD
1516 JUMP eat_msgin, WHEN MSG_IN
1517 JUMP eat_datain, WHEN DATA_IN
1518 JUMP eat_status, WHEN STATUS
1519 JUMP spew_dataout, WHEN DATA_OUT
1520 JUMP sated
1521 spew_cmd:
1522 MOVE 1, NCR53c7xx_zero, WHEN CMD
1523 JUMP sated
1524 eat_msgin:
1525 MOVE 1, NCR53c7xx_sink, WHEN MSG_IN
1526 JUMP eat_msgin, WHEN MSG_IN
1527 JUMP sated
1528 eat_status:
1529 MOVE 1, NCR53c7xx_sink, WHEN STATUS
1530 JUMP eat_status, WHEN STATUS
1531 JUMP sated
1532 eat_datain:
1533 MOVE 1, NCR53c7xx_sink, WHEN DATA_IN
1534 JUMP eat_datain, WHEN DATA_IN
1535 JUMP sated
1536 spew_dataout:
1537 MOVE 1, NCR53c7xx_zero, WHEN DATA_OUT
1538 sated:
1539 #if (CHIP != 710)
1540 MOVE SCNTL2 & 0x7f TO SCNTL2
1541 #endif
1542 MOVE 1, NCR53c7xx_msg_abort, WHEN MSG_OUT
1543 WAIT DISCONNECT
1544 INT int_norm_aborted
1546 #if (CHIP != 710)
1547 ;
1548 ; dsa_to_scratch
1549 ; scratch_to_dsa
1550 ;
1551 ; PURPOSE :
1552 ; The NCR chips cannot do a move memory instruction with the DSA register
1553 ; as the source or destination. So, we provide a couple of subroutines
1554 ; that let us switch between the DSA register and scratch register.
1555 ;
1556 ; Memory moves to/from the DSPS register also don't work, but we
1557 ; don't use them.
1558 ;
1559 ;
1562 dsa_to_scratch:
1563 MOVE DSA0 TO SFBR
1564 MOVE SFBR TO SCRATCH0
1565 MOVE DSA1 TO SFBR
1566 MOVE SFBR TO SCRATCH1
1567 MOVE DSA2 TO SFBR
1568 MOVE SFBR TO SCRATCH2
1569 MOVE DSA3 TO SFBR
1570 MOVE SFBR TO SCRATCH3
1571 RETURN
1573 scratch_to_dsa:
1574 MOVE SCRATCH0 TO SFBR
1575 MOVE SFBR TO DSA0
1576 MOVE SCRATCH1 TO SFBR
1577 MOVE SFBR TO DSA1
1578 MOVE SCRATCH2 TO SFBR
1579 MOVE SFBR TO DSA2
1580 MOVE SCRATCH3 TO SFBR
1581 MOVE SFBR TO DSA3
1582 RETURN
1583 #endif
1585 #if (CHIP == 710)
1586 ; Little patched jump, used to overcome problems with TEMP getting
1587 ; corrupted on memory moves.
1589 jump_temp:
1590 JUMP 0
1591 #endif