| blob | 3a36d9362a10f5e064a0867ebe54f5e2bdd91c16 |
1 /*
2 * Adaptec U320 device driver firmware for Linux and FreeBSD.
3 *
4 * Copyright (c) 1994-2001, 2004 Justin T. Gibbs.
5 * Copyright (c) 2000-2002 Adaptec Inc.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions, and the following disclaimer,
13 * without modification.
14 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
15 * substantially similar to the "NO WARRANTY" disclaimer below
16 * ("Disclaimer") and any redistribution must be conditioned upon
17 * including a substantially similar Disclaimer requirement for further
18 * binary redistribution.
19 * 3. Neither the names of the above-listed copyright holders nor the names
20 * of any contributors may be used to endorse or promote products derived
21 * from this software without specific prior written permission.
22 *
23 * Alternatively, this software may be distributed under the terms of the
24 * GNU General Public License ("GPL") version 2 as published by the Free
25 * Software Foundation.
26 *
27 * NO WARRANTY
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
36 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
37 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGES.
39 *
40 * $FreeBSD$
41 */
43 VERSION = "$Id: //depot/aic7xxx/aic7xxx/aic79xx.seq#120 $"
44 PATCH_ARG_LIST = "struct ahd_softc *ahd"
45 PREFIX = "ahd_"
47 #include "aic79xx.reg"
48 #include "scsi_message.h"
50 restart:
51 if ((ahd->bugs & AHD_INTCOLLISION_BUG) != 0) {
52 test SEQINTCODE, 0xFF jz idle_loop;
53 SET_SEQINTCODE(NO_SEQINT)
54 }
56 idle_loop:
58 if ((ahd->bugs & AHD_INTCOLLISION_BUG) != 0) {
59 /*
60 * Convert ERROR status into a sequencer
61 * interrupt to handle the case of an
62 * interrupt collision on the hardware
63 * setting of HWERR.
64 */
65 test ERROR, 0xFF jz no_error_set;
66 SET_SEQINTCODE(SAW_HWERR)
67 no_error_set:
68 }
69 SET_MODE(M_SCSI, M_SCSI)
70 test SCSISEQ0, ENSELO|ENARBO jnz idle_loop_checkbus;
71 test SEQ_FLAGS2, SELECTOUT_QFROZEN jz check_waiting_list;
72 /*
73 * If the kernel has caught up with us, thaw the queue.
74 */
75 mov A, KERNEL_QFREEZE_COUNT;
76 cmp QFREEZE_COUNT, A jne check_frozen_completions;
77 mov A, KERNEL_QFREEZE_COUNT[1];
78 cmp QFREEZE_COUNT[1], A jne check_frozen_completions;
79 and SEQ_FLAGS2, ~SELECTOUT_QFROZEN;
80 jmp check_waiting_list;
81 check_frozen_completions:
82 test SSTAT0, SELDO|SELINGO jnz idle_loop_checkbus;
83 BEGIN_CRITICAL;
84 /*
85 * If we have completions stalled waiting for the qfreeze
86 * to take effect, move them over to the complete_scb list
87 * now that no selections are pending.
88 */
89 cmp COMPLETE_ON_QFREEZE_HEAD[1],SCB_LIST_NULL je idle_loop_checkbus;
90 /*
91 * Find the end of the qfreeze list. The first element has
92 * to be treated specially.
93 */
94 bmov SCBPTR, COMPLETE_ON_QFREEZE_HEAD, 2;
95 cmp SCB_NEXT_COMPLETE[1], SCB_LIST_NULL je join_lists;
96 /*
97 * Now the normal loop.
98 */
99 bmov SCBPTR, SCB_NEXT_COMPLETE, 2;
100 cmp SCB_NEXT_COMPLETE[1], SCB_LIST_NULL jne . - 1;
101 join_lists:
102 bmov SCB_NEXT_COMPLETE, COMPLETE_SCB_HEAD, 2;
103 bmov COMPLETE_SCB_HEAD, COMPLETE_ON_QFREEZE_HEAD, 2;
104 mvi COMPLETE_ON_QFREEZE_HEAD[1], SCB_LIST_NULL;
105 jmp idle_loop_checkbus;
106 check_waiting_list:
107 cmp WAITING_TID_HEAD[1], SCB_LIST_NULL je idle_loop_checkbus;
108 /*
109 * ENSELO is cleared by a SELDO, so we must test for SELDO
110 * one last time.
111 */
112 test SSTAT0, SELDO jnz select_out;
113 call start_selection;
114 idle_loop_checkbus:
115 test SSTAT0, SELDO jnz select_out;
116 END_CRITICAL;
117 test SSTAT0, SELDI jnz select_in;
118 test SCSIPHASE, ~DATA_PHASE_MASK jz idle_loop_check_nonpackreq;
119 test SCSISIGO, ATNO jz idle_loop_check_nonpackreq;
120 call unexpected_nonpkt_phase_find_ctxt;
121 idle_loop_check_nonpackreq:
122 test SSTAT2, NONPACKREQ jz . + 2;
123 call unexpected_nonpkt_phase_find_ctxt;
124 if ((ahd->bugs & AHD_FAINT_LED_BUG) != 0) {
125 /*
126 * On Rev A. hardware, the busy LED is only
127 * turned on automaically during selections
128 * and re-selections. Make the LED status
129 * more useful by forcing it to be on so
130 * long as one of our data FIFOs is active.
131 */
132 and A, FIFO0FREE|FIFO1FREE, DFFSTAT;
133 cmp A, FIFO0FREE|FIFO1FREE jne . + 3;
134 and SBLKCTL, ~DIAGLEDEN|DIAGLEDON;
135 jmp . + 2;
136 or SBLKCTL, DIAGLEDEN|DIAGLEDON;
137 }
138 call idle_loop_gsfifo_in_scsi_mode;
139 call idle_loop_service_fifos;
140 call idle_loop_cchan;
141 jmp idle_loop;
143 idle_loop_gsfifo:
144 SET_MODE(M_SCSI, M_SCSI)
145 BEGIN_CRITICAL;
146 idle_loop_gsfifo_in_scsi_mode:
147 test LQISTAT2, LQIGSAVAIL jz return;
148 /*
149 * We have received good status for this transaction. There may
150 * still be data in our FIFOs draining to the host. Complete
151 * the SCB only if all data has transferred to the host.
152 */
153 good_status_IU_done:
154 bmov SCBPTR, GSFIFO, 2;
155 clr SCB_SCSI_STATUS;
156 /*
157 * If a command completed before an attempted task management
158 * function completed, notify the host after disabling any
159 * pending select-outs.
160 */
161 test SCB_TASK_MANAGEMENT, 0xFF jz gsfifo_complete_normally;
162 test SSTAT0, SELDO|SELINGO jnz . + 2;
163 and SCSISEQ0, ~ENSELO;
164 SET_SEQINTCODE(TASKMGMT_CMD_CMPLT_OKAY)
165 gsfifo_complete_normally:
166 or SCB_CONTROL, STATUS_RCVD;
168 /*
169 * Since this status did not consume a FIFO, we have to
170 * be a bit more dilligent in how we check for FIFOs pertaining
171 * to this transaction. There are two states that a FIFO still
172 * transferring data may be in.
173 *
174 * 1) Configured and draining to the host, with a FIFO handler.
175 * 2) Pending cfg4data, fifo not empty.
176 *
177 * Case 1 can be detected by noticing a non-zero FIFO active
178 * count in the SCB. In this case, we allow the routine servicing
179 * the FIFO to complete the SCB.
180 *
181 * Case 2 implies either a pending or yet to occur save data
182 * pointers for this same context in the other FIFO. So, if
183 * we detect case 1, we will properly defer the post of the SCB
184 * and achieve the desired result. The pending cfg4data will
185 * notice that status has been received and complete the SCB.
186 */
187 test SCB_FIFO_USE_COUNT, 0xFF jnz idle_loop_gsfifo_in_scsi_mode;
188 call complete;
189 END_CRITICAL;
190 jmp idle_loop_gsfifo_in_scsi_mode;
192 idle_loop_service_fifos:
193 SET_MODE(M_DFF0, M_DFF0)
194 BEGIN_CRITICAL;
195 test LONGJMP_ADDR[1], INVALID_ADDR jnz idle_loop_next_fifo;
196 call longjmp;
197 END_CRITICAL;
198 idle_loop_next_fifo:
199 SET_MODE(M_DFF1, M_DFF1)
200 BEGIN_CRITICAL;
201 test LONGJMP_ADDR[1], INVALID_ADDR jz longjmp;
202 END_CRITICAL;
203 return:
204 ret;
206 idle_loop_cchan:
207 SET_MODE(M_CCHAN, M_CCHAN)
208 test QOFF_CTLSTA, HS_MAILBOX_ACT jz hs_mailbox_empty;
209 or QOFF_CTLSTA, HS_MAILBOX_ACT;
210 mov LOCAL_HS_MAILBOX, HS_MAILBOX;
211 hs_mailbox_empty:
212 BEGIN_CRITICAL;
213 test CCSCBCTL, CCARREN|CCSCBEN jz scbdma_idle;
214 test CCSCBCTL, CCSCBDIR jnz fetch_new_scb_inprog;
215 test CCSCBCTL, CCSCBDONE jz return;
216 /* FALLTHROUGH */
217 scbdma_tohost_done:
218 test CCSCBCTL, CCARREN jz fill_qoutfifo_dmadone;
219 /*
220 * An SCB has been successfully uploaded to the host.
221 * If the SCB was uploaded for some reason other than
222 * bad SCSI status (currently only for underruns), we
223 * queue the SCB for normal completion. Otherwise, we
224 * wait until any select-out activity has halted, and
225 * then queue the completion.
226 */
227 and CCSCBCTL, ~(CCARREN|CCSCBEN);
228 bmov COMPLETE_DMA_SCB_HEAD, SCB_NEXT_COMPLETE, 2;
229 cmp SCB_NEXT_COMPLETE[1], SCB_LIST_NULL jne . + 2;
230 mvi COMPLETE_DMA_SCB_TAIL[1], SCB_LIST_NULL;
231 test SCB_SCSI_STATUS, 0xff jz scbdma_queue_completion;
232 bmov SCB_NEXT_COMPLETE, COMPLETE_ON_QFREEZE_HEAD, 2;
233 bmov COMPLETE_ON_QFREEZE_HEAD, SCBPTR, 2 ret;
234 scbdma_queue_completion:
235 bmov SCB_NEXT_COMPLETE, COMPLETE_SCB_HEAD, 2;
236 bmov COMPLETE_SCB_HEAD, SCBPTR, 2 ret;
237 fill_qoutfifo_dmadone:
238 and CCSCBCTL, ~(CCARREN|CCSCBEN);
239 call qoutfifo_updated;
240 mvi COMPLETE_SCB_DMAINPROG_HEAD[1], SCB_LIST_NULL;
241 bmov QOUTFIFO_NEXT_ADDR, SCBHADDR, 4;
242 test QOFF_CTLSTA, SDSCB_ROLLOVR jz return;
243 bmov QOUTFIFO_NEXT_ADDR, SHARED_DATA_ADDR, 4;
244 xor QOUTFIFO_ENTRY_VALID_TAG, QOUTFIFO_ENTRY_VALID_TOGGLE ret;
245 END_CRITICAL;
247 qoutfifo_updated:
248 /*
249 * If there are more commands waiting to be dma'ed
250 * to the host, always coalesce. Otherwise honor the
251 * host's wishes.
252 */
253 cmp COMPLETE_DMA_SCB_HEAD[1], SCB_LIST_NULL jne coalesce_by_count;
254 cmp COMPLETE_SCB_HEAD[1], SCB_LIST_NULL jne coalesce_by_count;
255 test LOCAL_HS_MAILBOX, ENINT_COALESCE jz issue_cmdcmplt;
257 /*
258 * If we have relatively few commands outstanding, don't
259 * bother waiting for another command to complete.
260 */
261 test CMDS_PENDING[1], 0xFF jnz coalesce_by_count;
262 /* Add -1 so that jnc means <= not just < */
263 add A, -1, INT_COALESCING_MINCMDS;
264 add NONE, A, CMDS_PENDING;
265 jnc issue_cmdcmplt;
267 /*
268 * If coalescing, only coalesce up to the limit
269 * provided by the host driver.
270 */
271 coalesce_by_count:
272 mov A, INT_COALESCING_MAXCMDS;
273 add NONE, A, INT_COALESCING_CMDCOUNT;
274 jc issue_cmdcmplt;
275 /*
276 * If the timer is not currently active,
277 * fire it up.
278 */
279 test INTCTL, SWTMINTMASK jz return;
280 bmov SWTIMER, INT_COALESCING_TIMER, 2;
281 mvi CLRSEQINTSTAT, CLRSEQ_SWTMRTO;
282 or INTCTL, SWTMINTEN|SWTIMER_START;
283 and INTCTL, ~SWTMINTMASK ret;
285 issue_cmdcmplt:
286 mvi INTSTAT, CMDCMPLT;
287 clr INT_COALESCING_CMDCOUNT;
288 or INTCTL, SWTMINTMASK ret;
290 BEGIN_CRITICAL;
291 fetch_new_scb_inprog:
292 test CCSCBCTL, ARRDONE jz return;
293 fetch_new_scb_done:
294 and CCSCBCTL, ~(CCARREN|CCSCBEN);
295 clr A;
296 add CMDS_PENDING, 1;
297 adc CMDS_PENDING[1], A;
298 if ((ahd->bugs & AHD_PKT_LUN_BUG) != 0) {
299 /*
300 * "Short Luns" are not placed into outgoing LQ
301 * packets in the correct byte order. Use a full
302 * sized lun field instead and fill it with the
303 * one byte of lun information we support.
304 */
305 mov SCB_PKT_LUN[6], SCB_LUN;
306 }
307 /*
308 * The FIFO use count field is shared with the
309 * tag set by the host so that our SCB dma engine
310 * knows the correct location to store the SCB.
311 * Set it to zero before processing the SCB.
312 */
313 clr SCB_FIFO_USE_COUNT;
314 /* Update the next SCB address to download. */
315 bmov NEXT_QUEUED_SCB_ADDR, SCB_NEXT_SCB_BUSADDR, 4;
316 /*
317 * NULL out the SCB links since these fields
318 * occupy the same location as SCB_NEXT_SCB_BUSADDR.
319 */
320 mvi SCB_NEXT[1], SCB_LIST_NULL;
321 mvi SCB_NEXT2[1], SCB_LIST_NULL;
322 /* Increment our position in the QINFIFO. */
323 mov NONE, SNSCB_QOFF;
325 /*
326 * Save SCBID of this SCB in REG0 since
327 * SCBPTR will be clobbered during target
328 * list updates. We also record the SCB's
329 * flags so that we can refer to them even
330 * after SCBPTR has been changed.
331 */
332 bmov REG0, SCBPTR, 2;
333 mov A, SCB_CONTROL;
335 /*
336 * Find the tail SCB of the execution queue
337 * for this target.
338 */
339 shr SINDEX, 3, SCB_SCSIID;
340 and SINDEX, ~0x1;
341 mvi SINDEX[1], (WAITING_SCB_TAILS >> 8);
342 bmov DINDEX, SINDEX, 2;
343 bmov SCBPTR, SINDIR, 2;
345 /*
346 * Update the tail to point to the new SCB.
347 */
348 bmov DINDIR, REG0, 2;
350 /*
351 * If the queue was empty, queue this SCB as
352 * the first for this target.
353 */
354 cmp SCBPTR[1], SCB_LIST_NULL je first_new_target_scb;
356 /*
357 * SCBs that want to send messages must always be
358 * at the head of their per-target queue so that
359 * ATN can be asserted even if the current
360 * negotiation agreement is packetized. If the
361 * target queue is empty, the SCB can be queued
362 * immediately. If the queue is not empty, we must
363 * wait for it to empty before entering this SCB
364 * into the waiting for selection queue. Otherwise
365 * our batching and round-robin selection scheme
366 * could allow commands to be queued out of order.
367 * To simplify the implementation, we stop pulling
368 * new commands from the host until the MK_MESSAGE
369 * SCB can be queued to the waiting for selection
370 * list.
371 */
372 test A, MK_MESSAGE jz batch_scb;
374 /*
375 * If the last SCB is also a MK_MESSAGE SCB, then
376 * order is preserved even if we batch.
377 */
378 test SCB_CONTROL, MK_MESSAGE jz batch_scb;
380 /*
381 * Defer this SCB and stop fetching new SCBs until
382 * it can be queued. Since the SCB_SCSIID of the
383 * tail SCB must be the same as that of the newly
384 * queued SCB, there is no need to restore the SCBID
385 * here.
386 */
387 or SEQ_FLAGS2, PENDING_MK_MESSAGE;
388 bmov MK_MESSAGE_SCB, REG0, 2;
389 mov MK_MESSAGE_SCSIID, SCB_SCSIID ret;
391 batch_scb:
392 /*
393 * Otherwise just update the previous tail SCB to
394 * point to the new tail.
395 */
396 bmov SCB_NEXT, REG0, 2 ret;
398 first_new_target_scb:
399 /*
400 * Append SCB to the tail of the waiting for
401 * selection list.
402 */
403 cmp WAITING_TID_HEAD[1], SCB_LIST_NULL je first_new_scb;
404 bmov SCBPTR, WAITING_TID_TAIL, 2;
405 bmov SCB_NEXT2, REG0, 2;
406 bmov WAITING_TID_TAIL, REG0, 2 ret;
407 first_new_scb:
408 /*
409 * Whole list is empty, so the head of
410 * the list must be initialized too.
411 */
412 bmov WAITING_TID_HEAD, REG0, 2;
413 bmov WAITING_TID_TAIL, REG0, 2 ret;
414 END_CRITICAL;
416 scbdma_idle:
417 /*
418 * Don't bother downloading new SCBs to execute
419 * if select-outs are currently frozen or we have
420 * a MK_MESSAGE SCB waiting to enter the queue.
421 */
422 test SEQ_FLAGS2, SELECTOUT_QFROZEN|PENDING_MK_MESSAGE
423 jnz scbdma_no_new_scbs;
424 BEGIN_CRITICAL;
425 test QOFF_CTLSTA, NEW_SCB_AVAIL jnz fetch_new_scb;
426 scbdma_no_new_scbs:
427 cmp COMPLETE_DMA_SCB_HEAD[1], SCB_LIST_NULL jne dma_complete_scb;
428 cmp COMPLETE_SCB_HEAD[1], SCB_LIST_NULL je return;
429 /* FALLTHROUGH */
430 fill_qoutfifo:
431 /*
432 * Keep track of the SCBs we are dmaing just
433 * in case the DMA fails or is aborted.
434 */
435 bmov COMPLETE_SCB_DMAINPROG_HEAD, COMPLETE_SCB_HEAD, 2;
436 mvi CCSCBCTL, CCSCBRESET;
437 bmov SCBHADDR, QOUTFIFO_NEXT_ADDR, 4;
438 mov A, QOUTFIFO_NEXT_ADDR;
439 bmov SCBPTR, COMPLETE_SCB_HEAD, 2;
440 fill_qoutfifo_loop:
441 bmov CCSCBRAM, SCBPTR, 2;
442 mov CCSCBRAM, SCB_SGPTR[0];
443 mov CCSCBRAM, QOUTFIFO_ENTRY_VALID_TAG;
444 mov NONE, SDSCB_QOFF;
445 inc INT_COALESCING_CMDCOUNT;
446 add CMDS_PENDING, -1;
447 adc CMDS_PENDING[1], -1;
448 cmp SCB_NEXT_COMPLETE[1], SCB_LIST_NULL je fill_qoutfifo_done;
449 cmp CCSCBADDR, CCSCBADDR_MAX je fill_qoutfifo_done;
450 test QOFF_CTLSTA, SDSCB_ROLLOVR jnz fill_qoutfifo_done;
451 /*
452 * Don't cross an ADB or Cachline boundary when DMA'ing
453 * completion entries. In PCI mode, at least in 32/33
454 * configurations, the SCB DMA engine may lose its place
455 * in the data-stream should the target force a retry on
456 * something other than an 8byte aligned boundary. In
457 * PCI-X mode, we do this to avoid split transactions since
458 * many chipsets seem to be unable to format proper split
459 * completions to continue the data transfer.
460 */
461 add SINDEX, A, CCSCBADDR;
462 test SINDEX, CACHELINE_MASK jz fill_qoutfifo_done;
463 bmov SCBPTR, SCB_NEXT_COMPLETE, 2;
464 jmp fill_qoutfifo_loop;
465 fill_qoutfifo_done:
466 mov SCBHCNT, CCSCBADDR;
467 mvi CCSCBCTL, CCSCBEN|CCSCBRESET;
468 bmov COMPLETE_SCB_HEAD, SCB_NEXT_COMPLETE, 2;
469 mvi SCB_NEXT_COMPLETE[1], SCB_LIST_NULL ret;
471 fetch_new_scb:
472 bmov SCBHADDR, NEXT_QUEUED_SCB_ADDR, 4;
473 mvi CCARREN|CCSCBEN|CCSCBDIR|CCSCBRESET jmp dma_scb;
474 dma_complete_scb:
475 bmov SCBPTR, COMPLETE_DMA_SCB_HEAD, 2;
476 bmov SCBHADDR, SCB_BUSADDR, 4;
477 mvi CCARREN|CCSCBEN|CCSCBRESET jmp dma_scb;
479 /*
480 * Either post or fetch an SCB from host memory. The caller
481 * is responsible for polling for transfer completion.
482 *
483 * Prerequisits: Mode == M_CCHAN
484 * SINDEX contains CCSCBCTL flags
485 * SCBHADDR set to Host SCB address
486 * SCBPTR set to SCB src location on "push" operations
487 */
488 SET_SRC_MODE M_CCHAN;
489 SET_DST_MODE M_CCHAN;
490 dma_scb:
491 mvi SCBHCNT, SCB_TRANSFER_SIZE;
492 mov CCSCBCTL, SINDEX ret;
494 setjmp:
495 /*
496 * At least on the A, a return in the same
497 * instruction as the bmov results in a return
498 * to the caller, not to the new address at the
499 * top of the stack. Since we want the latter
500 * (we use setjmp to register a handler from an
501 * interrupt context but not invoke that handler
502 * until we return to our idle loop), use a
503 * separate ret instruction.
504 */
505 bmov LONGJMP_ADDR, STACK, 2;
506 ret;
507 setjmp_inline:
508 bmov LONGJMP_ADDR, STACK, 2;
509 longjmp:
510 bmov STACK, LONGJMP_ADDR, 2 ret;
511 END_CRITICAL;
513 /*************************** Chip Bug Work Arounds ****************************/
514 /*
515 * Must disable interrupts when setting the mode pointer
516 * register as an interrupt occurring mid update will
517 * fail to store the new mode value for restoration on
518 * an iret.
519 */
520 if ((ahd->bugs & AHD_SET_MODE_BUG) != 0) {
521 set_mode_work_around:
522 mvi SEQINTCTL, INTVEC1DSL;
523 mov MODE_PTR, SINDEX;
524 clr SEQINTCTL ret;
525 }
528 if ((ahd->bugs & AHD_INTCOLLISION_BUG) != 0) {
529 set_seqint_work_around:
530 mov SEQINTCODE, SINDEX;
531 mvi SEQINTCODE, NO_SEQINT ret;
532 }
534 /************************ Packetized LongJmp Routines *************************/
535 SET_SRC_MODE M_SCSI;
536 SET_DST_MODE M_SCSI;
537 start_selection:
538 BEGIN_CRITICAL;
539 if ((ahd->bugs & AHD_SENT_SCB_UPDATE_BUG) != 0) {
540 /*
541 * Razor #494
542 * Rev A hardware fails to update LAST/CURR/NEXTSCB
543 * correctly after a packetized selection in several
544 * situations:
545 *
546 * 1) If only one command existed in the queue, the
547 * LAST/CURR/NEXTSCB are unchanged.
548 *
549 * 2) In a non QAS, protocol allowed phase change,
550 * the queue is shifted 1 too far. LASTSCB is
551 * the last SCB that was correctly processed.
552 *
553 * 3) In the QAS case, if the full list of commands
554 * was successfully sent, NEXTSCB is NULL and neither
555 * CURRSCB nor LASTSCB can be trusted. We must
556 * manually walk the list counting MAXCMDCNT elements
557 * to find the last SCB that was sent correctly.
558 *
559 * To simplify the workaround for this bug in SELDO
560 * handling, we initialize LASTSCB prior to enabling
561 * selection so we can rely on it even for case #1 above.
562 */
563 bmov LASTSCB, WAITING_TID_HEAD, 2;
564 }
565 bmov CURRSCB, WAITING_TID_HEAD, 2;
566 bmov SCBPTR, WAITING_TID_HEAD, 2;
567 shr SELOID, 4, SCB_SCSIID;
568 /*
569 * If we want to send a message to the device, ensure
570 * we are selecting with atn regardless of our packetized
571 * agreement. Since SPI4 only allows target reset or PPR
572 * messages if this is a packetized connection, the change
573 * to our negotiation table entry for this selection will
574 * be cleared when the message is acted on.
575 */
576 test SCB_CONTROL, MK_MESSAGE jz . + 3;
577 mov NEGOADDR, SELOID;
578 or NEGCONOPTS, ENAUTOATNO;
579 or SCSISEQ0, ENSELO ret;
580 END_CRITICAL;
582 /*
583 * Allocate a FIFO for a non-packetized transaction.
584 * In RevA hardware, both FIFOs must be free before we
585 * can allocate a FIFO for a non-packetized transaction.
586 */
587 allocate_fifo_loop:
588 /*
589 * Do whatever work is required to free a FIFO.
590 */
591 call idle_loop_service_fifos;
592 SET_MODE(M_SCSI, M_SCSI)
593 allocate_fifo:
594 if ((ahd->bugs & AHD_NONPACKFIFO_BUG) != 0) {
595 and A, FIFO0FREE|FIFO1FREE, DFFSTAT;
596 cmp A, FIFO0FREE|FIFO1FREE jne allocate_fifo_loop;
597 } else {
598 test DFFSTAT, FIFO1FREE jnz allocate_fifo1;
599 test DFFSTAT, FIFO0FREE jz allocate_fifo_loop;
600 mvi DFFSTAT, B_CURRFIFO_0;
601 SET_MODE(M_DFF0, M_DFF0)
602 bmov SCBPTR, ALLOCFIFO_SCBPTR, 2 ret;
603 }
604 SET_SRC_MODE M_SCSI;
605 SET_DST_MODE M_SCSI;
606 allocate_fifo1:
607 mvi DFFSTAT, CURRFIFO_1;
608 SET_MODE(M_DFF1, M_DFF1)
609 bmov SCBPTR, ALLOCFIFO_SCBPTR, 2 ret;
611 /*
612 * We have been reselected as an initiator
613 * or selected as a target.
614 */
615 SET_SRC_MODE M_SCSI;
616 SET_DST_MODE M_SCSI;
617 select_in:
618 if ((ahd->bugs & AHD_FAINT_LED_BUG) != 0) {
619 /*
620 * On Rev A. hardware, the busy LED is only
621 * turned on automaically during selections
622 * and re-selections. Make the LED status
623 * more useful by forcing it to be on from
624 * the point of selection until our idle
625 * loop determines that neither of our FIFOs
626 * are busy. This handles the non-packetized
627 * case nicely as we will not return to the
628 * idle loop until the busfree at the end of
629 * each transaction.
630 */
631 or SBLKCTL, DIAGLEDEN|DIAGLEDON;
632 }
633 if ((ahd->bugs & AHD_BUSFREEREV_BUG) != 0) {
634 /*
635 * Test to ensure that the bus has not
636 * already gone free prior to clearing
637 * any stale busfree status. This avoids
638 * a window whereby a busfree just after
639 * a selection could be missed.
640 */
641 test SCSISIGI, BSYI jz . + 2;
642 mvi CLRSINT1,CLRBUSFREE;
643 or SIMODE1, ENBUSFREE;
644 }
645 or SXFRCTL0, SPIOEN;
646 and SAVED_SCSIID, SELID_MASK, SELID;
647 and A, OID, IOWNID;
648 or SAVED_SCSIID, A;
649 mvi CLRSINT0, CLRSELDI;
650 jmp ITloop;
652 /*
653 * We have successfully selected out.
654 *
655 * Clear SELDO.
656 * Dequeue all SCBs sent from the waiting queue
657 * Requeue all SCBs *not* sent to the tail of the waiting queue
658 * Take Razor #494 into account for above.
659 *
660 * In Packetized Mode:
661 * Return to the idle loop. Our interrupt handler will take
662 * care of any incoming L_Qs.
663 *
664 * In Non-Packetize Mode:
665 * Continue to our normal state machine.
666 */
667 SET_SRC_MODE M_SCSI;
668 SET_DST_MODE M_SCSI;
669 select_out:
670 BEGIN_CRITICAL;
671 if ((ahd->bugs & AHD_FAINT_LED_BUG) != 0) {
672 /*
673 * On Rev A. hardware, the busy LED is only
674 * turned on automaically during selections
675 * and re-selections. Make the LED status
676 * more useful by forcing it to be on from
677 * the point of re-selection until our idle
678 * loop determines that neither of our FIFOs
679 * are busy. This handles the non-packetized
680 * case nicely as we will not return to the
681 * idle loop until the busfree at the end of
682 * each transaction.
683 */
684 or SBLKCTL, DIAGLEDEN|DIAGLEDON;
685 }
686 /* Clear out all SCBs that have been successfully sent. */
687 if ((ahd->bugs & AHD_SENT_SCB_UPDATE_BUG) != 0) {
688 /*
689 * For packetized, the LQO manager clears ENSELO on
690 * the assertion of SELDO. If we are non-packetized,
691 * LASTSCB and CURRSCB are accurate.
692 */
693 test SCSISEQ0, ENSELO jnz use_lastscb;
695 /*
696 * The update is correct for LQOSTAT1 errors. All
697 * but LQOBUSFREE are handled by kernel interrupts.
698 * If we see LQOBUSFREE, return to the idle loop.
699 * Once we are out of the select_out critical section,
700 * the kernel will cleanup the LQOBUSFREE and we will
701 * eventually restart the selection if appropriate.
702 */
703 test LQOSTAT1, LQOBUSFREE jnz idle_loop;
705 /*
706 * On a phase change oustside of packet boundaries,
707 * LASTSCB points to the currently active SCB context
708 * on the bus.
709 */
710 test LQOSTAT2, LQOPHACHGOUTPKT jnz use_lastscb;
712 /*
713 * If the hardware has traversed the whole list, NEXTSCB
714 * will be NULL, CURRSCB and LASTSCB cannot be trusted,
715 * but MAXCMDCNT is accurate. If we stop part way through
716 * the list or only had one command to issue, NEXTSCB[1] is
717 * not NULL and LASTSCB is the last command to go out.
718 */
719 cmp NEXTSCB[1], SCB_LIST_NULL jne use_lastscb;
721 /*
722 * Brute force walk.
723 */
724 bmov SCBPTR, WAITING_TID_HEAD, 2;
725 mvi SEQINTCTL, INTVEC1DSL;
726 mvi MODE_PTR, MK_MODE(M_CFG, M_CFG);
727 mov A, MAXCMDCNT;
728 mvi MODE_PTR, MK_MODE(M_SCSI, M_SCSI);
729 clr SEQINTCTL;
730 find_lastscb_loop:
731 dec A;
732 test A, 0xFF jz found_last_sent_scb;
733 bmov SCBPTR, SCB_NEXT, 2;
734 jmp find_lastscb_loop;
735 use_lastscb:
736 bmov SCBPTR, LASTSCB, 2;
737 found_last_sent_scb:
738 bmov CURRSCB, SCBPTR, 2;
739 curscb_ww_done:
740 } else {
741 bmov SCBPTR, CURRSCB, 2;
742 }
744 /*
745 * The whole list made it. Clear our tail pointer to indicate
746 * that the per-target selection queue is now empty.
747 */
748 cmp SCB_NEXT[1], SCB_LIST_NULL je select_out_clear_tail;
750 /*
751 * Requeue any SCBs not sent, to the tail of the waiting Q.
752 * We know that neither the per-TID list nor the list of
753 * TIDs is empty. Use this knowledge to our advantage and
754 * queue the remainder to the tail of the global execution
755 * queue.
756 */
757 bmov REG0, SCB_NEXT, 2;
758 select_out_queue_remainder:
759 bmov SCBPTR, WAITING_TID_TAIL, 2;
760 bmov SCB_NEXT2, REG0, 2;
761 bmov WAITING_TID_TAIL, REG0, 2;
762 jmp select_out_inc_tid_q;
764 select_out_clear_tail:
765 /*
766 * Queue any pending MK_MESSAGE SCB for this target now
767 * that the queue is empty.
768 */
769 test SEQ_FLAGS2, PENDING_MK_MESSAGE jz select_out_no_mk_message_scb;
770 mov A, MK_MESSAGE_SCSIID;
771 cmp SCB_SCSIID, A jne select_out_no_mk_message_scb;
772 and SEQ_FLAGS2, ~PENDING_MK_MESSAGE;
773 bmov REG0, MK_MESSAGE_SCB, 2;
774 jmp select_out_queue_remainder;
776 select_out_no_mk_message_scb:
777 /*
778 * Clear this target's execution tail and increment the queue.
779 */
780 shr DINDEX, 3, SCB_SCSIID;
781 or DINDEX, 1; /* Want only the second byte */
782 mvi DINDEX[1], ((WAITING_SCB_TAILS) >> 8);
783 mvi DINDIR, SCB_LIST_NULL;
784 select_out_inc_tid_q:
785 bmov SCBPTR, WAITING_TID_HEAD, 2;
786 bmov WAITING_TID_HEAD, SCB_NEXT2, 2;
787 cmp WAITING_TID_HEAD[1], SCB_LIST_NULL jne . + 2;
788 mvi WAITING_TID_TAIL[1], SCB_LIST_NULL;
789 bmov SCBPTR, CURRSCB, 2;
790 mvi CLRSINT0, CLRSELDO;
791 test LQOSTAT2, LQOPHACHGOUTPKT jnz unexpected_nonpkt_mode_cleared;
792 test LQOSTAT1, LQOPHACHGINPKT jnz unexpected_nonpkt_mode_cleared;
794 /*
795 * If this is a packetized connection, return to our
796 * idle_loop and let our interrupt handler deal with
797 * any connection setup/teardown issues. The only
798 * exceptions are the case of MK_MESSAGE and task management
799 * SCBs.
800 */
801 if ((ahd->bugs & AHD_LQO_ATNO_BUG) != 0) {
802 /*
803 * In the A, the LQO manager transitions to LQOSTOP0 even if
804 * we have selected out with ATN asserted and the target
805 * REQs in a non-packet phase.
806 */
807 test SCB_CONTROL, MK_MESSAGE jz select_out_no_message;
808 test SCSISIGO, ATNO jnz select_out_non_packetized;
809 select_out_no_message:
810 }
811 test LQOSTAT2, LQOSTOP0 jz select_out_non_packetized;
812 test SCB_TASK_MANAGEMENT, 0xFF jz idle_loop;
813 SET_SEQINTCODE(TASKMGMT_FUNC_COMPLETE)
814 jmp idle_loop;
816 select_out_non_packetized:
817 /* Non packetized request. */
818 and SCSISEQ0, ~ENSELO;
819 if ((ahd->bugs & AHD_BUSFREEREV_BUG) != 0) {
820 /*
821 * Test to ensure that the bus has not
822 * already gone free prior to clearing
823 * any stale busfree status. This avoids
824 * a window whereby a busfree just after
825 * a selection could be missed.
826 */
827 test SCSISIGI, BSYI jz . + 2;
828 mvi CLRSINT1,CLRBUSFREE;
829 or SIMODE1, ENBUSFREE;
830 }
831 mov SAVED_SCSIID, SCB_SCSIID;
832 mov SAVED_LUN, SCB_LUN;
833 mvi SEQ_FLAGS, NO_CDB_SENT;
834 END_CRITICAL;
835 or SXFRCTL0, SPIOEN;
837 /*
838 * As soon as we get a successful selection, the target
839 * should go into the message out phase since we have ATN
840 * asserted.
841 */
842 mvi MSG_OUT, MSG_IDENTIFYFLAG;
844 /*
845 * Main loop for information transfer phases. Wait for the
846 * target to assert REQ before checking MSG, C/D and I/O for
847 * the bus phase.
848 */
849 mesgin_phasemis:
850 ITloop:
851 call phase_lock;
853 mov A, LASTPHASE;
855 test A, ~P_DATAIN_DT jz p_data;
856 cmp A,P_COMMAND je p_command;
857 cmp A,P_MESGOUT je p_mesgout;
858 cmp A,P_STATUS je p_status;
859 cmp A,P_MESGIN je p_mesgin;
861 SET_SEQINTCODE(BAD_PHASE)
862 jmp ITloop; /* Try reading the bus again. */
864 /*
865 * Command phase. Set up the DMA registers and let 'er rip.
866 */
867 p_command:
868 test SEQ_FLAGS, NOT_IDENTIFIED jz p_command_okay;
869 SET_SEQINTCODE(PROTO_VIOLATION)
870 p_command_okay:
871 test MODE_PTR, ~(MK_MODE(M_DFF1, M_DFF1))
872 jnz p_command_allocate_fifo;
873 /*
874 * Command retry. Free our current FIFO and
875 * re-allocate a FIFO so transfer state is
876 * reset.
877 */
878 SET_SRC_MODE M_DFF1;
879 SET_DST_MODE M_DFF1;
880 mvi DFFSXFRCTL, RSTCHN|CLRSHCNT;
881 SET_MODE(M_SCSI, M_SCSI)
882 p_command_allocate_fifo:
883 bmov ALLOCFIFO_SCBPTR, SCBPTR, 2;
884 call allocate_fifo;
885 SET_SRC_MODE M_DFF1;
886 SET_DST_MODE M_DFF1;
887 add NONE, -17, SCB_CDB_LEN;
888 jnc p_command_embedded;
889 p_command_from_host:
890 bmov HADDR[0], SCB_HOST_CDB_PTR, 9;
891 mvi SG_CACHE_PRE, LAST_SEG;
892 mvi DFCNTRL, (PRELOADEN|SCSIEN|HDMAEN);
893 jmp p_command_xfer;
894 p_command_embedded:
895 bmov SHCNT[0], SCB_CDB_LEN, 1;
896 bmov DFDAT, SCB_CDB_STORE, 16;
897 mvi DFCNTRL, SCSIEN;
898 p_command_xfer:
899 and SEQ_FLAGS, ~NO_CDB_SENT;
900 if ((ahd->features & AHD_FAST_CDB_DELIVERY) != 0) {
901 /*
902 * To speed up CDB delivery in Rev B, all CDB acks
903 * are "released" to the output sync as soon as the
904 * command phase starts. There is only one problem
905 * with this approach. If the target changes phase
906 * before all data are sent, we have left over acks
907 * that can go out on the bus in a data phase. Due
908 * to other chip contraints, this only happens if
909 * the target goes to data-in, but if the acks go
910 * out before we can test SDONE, we'll think that
911 * the transfer has completed successfully. Work
912 * around this by taking advantage of the 400ns or
913 * 800ns dead time between command phase and the REQ
914 * of the new phase. If the transfer has completed
915 * successfully, SCSIEN should fall *long* before we
916 * see a phase change. We thus treat any phasemiss
917 * that occurs before SCSIEN falls as an incomplete
918 * transfer.
919 */
920 test SSTAT1, PHASEMIS jnz p_command_xfer_failed;
921 test DFCNTRL, SCSIEN jnz . - 1;
922 } else {
923 test DFCNTRL, SCSIEN jnz .;
924 }
925 /*
926 * DMA Channel automatically disabled.
927 * Don't allow a data phase if the command
928 * was not fully transferred.
929 */
930 test SSTAT2, SDONE jnz ITloop;
931 p_command_xfer_failed:
932 or SEQ_FLAGS, NO_CDB_SENT;
933 jmp ITloop;
936 /*
937 * Status phase. Wait for the data byte to appear, then read it
938 * and store it into the SCB.
939 */
940 SET_SRC_MODE M_SCSI;
941 SET_DST_MODE M_SCSI;
942 p_status:
943 test SEQ_FLAGS,NOT_IDENTIFIED jnz mesgin_proto_violation;
944 p_status_okay:
945 mov SCB_SCSI_STATUS, SCSIDAT;
946 or SCB_CONTROL, STATUS_RCVD;
947 jmp ITloop;
949 /*
950 * Message out phase. If MSG_OUT is MSG_IDENTIFYFLAG, build a full
951 * indentify message sequence and send it to the target. The host may
952 * override this behavior by setting the MK_MESSAGE bit in the SCB
953 * control byte. This will cause us to interrupt the host and allow
954 * it to handle the message phase completely on its own. If the bit
955 * associated with this target is set, we will also interrupt the host,
956 * thereby allowing it to send a message on the next selection regardless
957 * of the transaction being sent.
958 *
959 * If MSG_OUT is == HOST_MSG, also interrupt the host and take a message.
960 * This is done to allow the host to send messages outside of an identify
961 * sequence while protecting the seqencer from testing the MK_MESSAGE bit
962 * on an SCB that might not be for the current nexus. (For example, a
963 * BDR message in response to a bad reselection would leave us pointed to
964 * an SCB that doesn't have anything to do with the current target).
965 *
966 * Otherwise, treat MSG_OUT as a 1 byte message to send (abort, abort tag,
967 * bus device reset).
968 *
969 * When there are no messages to send, MSG_OUT should be set to MSG_NOOP,
970 * in case the target decides to put us in this phase for some strange
971 * reason.
972 */
973 p_mesgout_retry:
974 /* Turn on ATN for the retry */
975 mvi SCSISIGO, ATNO;
976 p_mesgout:
977 mov SINDEX, MSG_OUT;
978 cmp SINDEX, MSG_IDENTIFYFLAG jne p_mesgout_from_host;
979 test SCB_CONTROL,MK_MESSAGE jnz host_message_loop;
980 p_mesgout_identify:
981 or SINDEX, MSG_IDENTIFYFLAG|DISCENB, SCB_LUN;
982 test SCB_CONTROL, DISCENB jnz . + 2;
983 and SINDEX, ~DISCENB;
984 /*
985 * Send a tag message if TAG_ENB is set in the SCB control block.
986 * Use SCB_NONPACKET_TAG as the tag value.
987 */
988 p_mesgout_tag:
989 test SCB_CONTROL,TAG_ENB jz p_mesgout_onebyte;
990 mov SCSIDAT, SINDEX; /* Send the identify message */
991 call phase_lock;
992 cmp LASTPHASE, P_MESGOUT jne p_mesgout_done;
993 and SCSIDAT,TAG_ENB|SCB_TAG_TYPE,SCB_CONTROL;
994 call phase_lock;
995 cmp LASTPHASE, P_MESGOUT jne p_mesgout_done;
996 mov SCBPTR jmp p_mesgout_onebyte;
997 /*
998 * Interrupt the driver, and allow it to handle this message
999 * phase and any required retries.
1000 */
1001 p_mesgout_from_host:
1002 cmp SINDEX, HOST_MSG jne p_mesgout_onebyte;
1003 jmp host_message_loop;
1005 p_mesgout_onebyte:
1006 mvi CLRSINT1, CLRATNO;
1007 mov SCSIDAT, SINDEX;
1009 /*
1010 * If the next bus phase after ATN drops is message out, it means
1011 * that the target is requesting that the last message(s) be resent.
1012 */
1013 call phase_lock;
1014 cmp LASTPHASE, P_MESGOUT je p_mesgout_retry;
1016 p_mesgout_done:
1017 mvi CLRSINT1,CLRATNO; /* Be sure to turn ATNO off */
1018 mov LAST_MSG, MSG_OUT;
1019 mvi MSG_OUT, MSG_NOOP; /* No message left */
1020 jmp ITloop;
1022 /*
1023 * Message in phase. Bytes are read using Automatic PIO mode.
1024 */
1025 p_mesgin:
1026 /* read the 1st message byte */
1027 mvi ACCUM call inb_first;
1029 test A,MSG_IDENTIFYFLAG jnz mesgin_identify;
1030 cmp A,MSG_DISCONNECT je mesgin_disconnect;
1031 cmp A,MSG_SAVEDATAPOINTER je mesgin_sdptrs;
1032 cmp ALLZEROS,A je mesgin_complete;
1033 cmp A,MSG_RESTOREPOINTERS je mesgin_rdptrs;
1034 cmp A,MSG_IGN_WIDE_RESIDUE je mesgin_ign_wide_residue;
1035 cmp A,MSG_NOOP je mesgin_done;
1037 /*
1038 * Pushed message loop to allow the kernel to
1039 * run it's own message state engine. To avoid an
1040 * extra nop instruction after signaling the kernel,
1041 * we perform the phase_lock before checking to see
1042 * if we should exit the loop and skip the phase_lock
1043 * in the ITloop. Performing back to back phase_locks
1044 * shouldn't hurt, but why do it twice...
1045 */
1046 host_message_loop:
1047 call phase_lock; /* Benign the first time through. */
1048 SET_SEQINTCODE(HOST_MSG_LOOP)
1049 cmp RETURN_1, EXIT_MSG_LOOP je ITloop;
1050 cmp RETURN_1, CONT_MSG_LOOP_WRITE jne . + 3;
1051 mov SCSIDAT, RETURN_2;
1052 jmp host_message_loop;
1053 /* Must be CONT_MSG_LOOP_READ */
1054 mov NONE, SCSIDAT; /* ACK Byte */
1055 jmp host_message_loop;
1057 mesgin_ign_wide_residue:
1058 mov SAVED_MODE, MODE_PTR;
1059 SET_MODE(M_SCSI, M_SCSI)
1060 shr NEGOADDR, 4, SAVED_SCSIID;
1061 mov A, NEGCONOPTS;
1062 RESTORE_MODE(SAVED_MODE)
1063 test A, WIDEXFER jz mesgin_reject;
1064 /* Pull the residue byte */
1065 mvi REG0 call inb_next;
1066 cmp REG0, 0x01 jne mesgin_reject;
1067 test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz . + 2;
1068 test SCB_TASK_ATTRIBUTE, SCB_XFERLEN_ODD jnz mesgin_done;
1069 SET_SEQINTCODE(IGN_WIDE_RES)
1070 jmp mesgin_done;
1072 mesgin_proto_violation:
1073 SET_SEQINTCODE(PROTO_VIOLATION)
1074 jmp mesgin_done;
1075 mesgin_reject:
1076 mvi MSG_MESSAGE_REJECT call mk_mesg;
1077 mesgin_done:
1078 mov NONE,SCSIDAT; /*dummy read from latch to ACK*/
1079 jmp ITloop;
1081 #define INDEX_DISC_LIST(scsiid, lun) \
1082 and A, 0xC0, scsiid; \
1083 or SCBPTR, A, lun; \
1084 clr SCBPTR[1]; \
1085 and SINDEX, 0x30, scsiid; \
1086 shr SINDEX, 3; /* Multiply by 2 */ \
1087 add SINDEX, (SCB_DISCONNECTED_LISTS & 0xFF); \
1088 mvi SINDEX[1], ((SCB_DISCONNECTED_LISTS >> 8) & 0xFF)
1090 mesgin_identify:
1091 /*
1092 * Determine whether a target is using tagged or non-tagged
1093 * transactions by first looking at the transaction stored in
1094 * the per-device, disconnected array. If there is no untagged
1095 * transaction for this target, this must be a tagged transaction.
1096 */
1097 and SAVED_LUN, MSG_IDENTIFY_LUNMASK, A;
1098 INDEX_DISC_LIST(SAVED_SCSIID, SAVED_LUN);
1099 bmov DINDEX, SINDEX, 2;
1100 bmov REG0, SINDIR, 2;
1101 cmp REG0[1], SCB_LIST_NULL je snoop_tag;
1102 /* Untagged. Clear the busy table entry and setup the SCB. */
1103 bmov DINDIR, ALLONES, 2;
1104 bmov SCBPTR, REG0, 2;
1105 jmp setup_SCB;
1107 /*
1108 * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message.
1109 * If we get one, we use the tag returned to find the proper
1110 * SCB. After receiving the tag, look for the SCB at SCB locations tag and
1111 * tag + 256.
1112 */
1113 snoop_tag:
1114 if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) {
1115 or SEQ_FLAGS, 0x80;
1116 }
1117 mov NONE, SCSIDAT; /* ACK Identify MSG */
1118 call phase_lock;
1119 if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) {
1120 or SEQ_FLAGS, 0x1;
1121 }
1122 cmp LASTPHASE, P_MESGIN jne not_found_ITloop;
1123 if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) {
1124 or SEQ_FLAGS, 0x2;
1125 }
1126 cmp SCSIBUS, MSG_SIMPLE_Q_TAG jne not_found;
1127 get_tag:
1128 clr SCBPTR[1];
1129 mvi SCBPTR call inb_next; /* tag value */
1130 verify_scb:
1131 test SCB_CONTROL,DISCONNECTED jz verify_other_scb;
1132 mov A, SAVED_SCSIID;
1133 cmp SCB_SCSIID, A jne verify_other_scb;
1134 mov A, SAVED_LUN;
1135 cmp SCB_LUN, A je setup_SCB_disconnected;
1136 verify_other_scb:
1137 xor SCBPTR[1], 1;
1138 test SCBPTR[1], 0xFF jnz verify_scb;
1139 jmp not_found;
1141 /*
1142 * Ensure that the SCB the tag points to is for
1143 * an SCB transaction to the reconnecting target.
1144 */
1145 setup_SCB:
1146 if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) {
1147 or SEQ_FLAGS, 0x10;
1148 }
1149 test SCB_CONTROL,DISCONNECTED jz not_found;
1150 setup_SCB_disconnected:
1151 and SCB_CONTROL,~DISCONNECTED;
1152 clr SEQ_FLAGS; /* make note of IDENTIFY */
1153 test SCB_SGPTR, SG_LIST_NULL jnz . + 3;
1154 bmov ALLOCFIFO_SCBPTR, SCBPTR, 2;
1155 call allocate_fifo;
1156 /* See if the host wants to send a message upon reconnection */
1157 test SCB_CONTROL, MK_MESSAGE jz mesgin_done;
1158 mvi HOST_MSG call mk_mesg;
1159 jmp mesgin_done;
1161 not_found:
1162 SET_SEQINTCODE(NO_MATCH)
1163 jmp mesgin_done;
1165 not_found_ITloop:
1166 SET_SEQINTCODE(NO_MATCH)
1167 jmp ITloop;
1169 /*
1170 * We received a "command complete" message. Put the SCB on the complete
1171 * queue and trigger a completion interrupt via the idle loop. Before doing
1172 * so, check to see if there is a residual or the status byte is something
1173 * other than STATUS_GOOD (0). In either of these conditions, we upload the
1174 * SCB back to the host so it can process this information.
1175 */
1176 mesgin_complete:
1178 /*
1179 * If ATN is raised, we still want to give the target a message.
1180 * Perhaps there was a parity error on this last message byte.
1181 * Either way, the target should take us to message out phase
1182 * and then attempt to complete the command again. We should use a
1183 * critical section here to guard against a timeout triggering
1184 * for this command and setting ATN while we are still processing
1185 * the completion.
1186 test SCSISIGI, ATNI jnz mesgin_done;
1187 */
1189 /*
1190 * If we are identified and have successfully sent the CDB,
1191 * any status will do. Optimize this fast path.
1192 */
1193 test SCB_CONTROL, STATUS_RCVD jz mesgin_proto_violation;
1194 test SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT jz complete_accepted;
1196 /*
1197 * If the target never sent an identify message but instead went
1198 * to mesgin to give an invalid message, let the host abort us.
1199 */
1200 test SEQ_FLAGS, NOT_IDENTIFIED jnz mesgin_proto_violation;
1202 /*
1203 * If we recevied good status but never successfully sent the
1204 * cdb, abort the command.
1205 */
1206 test SCB_SCSI_STATUS,0xff jnz complete_accepted;
1207 test SEQ_FLAGS, NO_CDB_SENT jnz mesgin_proto_violation;
1208 complete_accepted:
1210 /*
1211 * See if we attempted to deliver a message but the target ingnored us.
1212 */
1213 test SCB_CONTROL, MK_MESSAGE jz complete_nomsg;
1214 SET_SEQINTCODE(MKMSG_FAILED)
1215 complete_nomsg:
1216 call queue_scb_completion;
1217 jmp await_busfree;
1219 BEGIN_CRITICAL;
1220 freeze_queue:
1221 /* Cancel any pending select-out. */
1222 test SSTAT0, SELDO|SELINGO jnz . + 2;
1223 and SCSISEQ0, ~ENSELO;
1224 mov ACCUM_SAVE, A;
1225 clr A;
1226 add QFREEZE_COUNT, 1;
1227 adc QFREEZE_COUNT[1], A;
1228 or SEQ_FLAGS2, SELECTOUT_QFROZEN;
1229 mov A, ACCUM_SAVE ret;
1230 END_CRITICAL;
1232 /*
1233 * Complete the current FIFO's SCB if data for this same
1234 * SCB is not transferring in the other FIFO.
1235 */
1236 SET_SRC_MODE M_DFF1;
1237 SET_DST_MODE M_DFF1;
1238 pkt_complete_scb_if_fifos_idle:
1239 bmov ARG_1, SCBPTR, 2;
1240 mvi DFFSXFRCTL, CLRCHN;
1241 SET_MODE(M_SCSI, M_SCSI)
1242 bmov SCBPTR, ARG_1, 2;
1243 test SCB_FIFO_USE_COUNT, 0xFF jnz return;
1244 queue_scb_completion:
1245 test SCB_SCSI_STATUS,0xff jnz bad_status;
1246 /*
1247 * Check for residuals
1248 */
1249 test SCB_SGPTR, SG_LIST_NULL jnz complete; /* No xfer */
1250 test SCB_SGPTR, SG_FULL_RESID jnz upload_scb;/* Never xfered */
1251 test SCB_RESIDUAL_SGPTR, SG_LIST_NULL jz upload_scb;
1252 complete:
1253 BEGIN_CRITICAL;
1254 bmov SCB_NEXT_COMPLETE, COMPLETE_SCB_HEAD, 2;
1255 bmov COMPLETE_SCB_HEAD, SCBPTR, 2 ret;
1256 END_CRITICAL;
1257 bad_status:
1258 cmp SCB_SCSI_STATUS, STATUS_PKT_SENSE je upload_scb;
1259 call freeze_queue;
1260 upload_scb:
1261 /*
1262 * Restore SCB TAG since we reuse this field
1263 * in the sequencer. We don't want to corrupt
1264 * it on the host.
1265 */
1266 bmov SCB_TAG, SCBPTR, 2;
1267 BEGIN_CRITICAL;
1268 or SCB_SGPTR, SG_STATUS_VALID;
1269 mvi SCB_NEXT_COMPLETE[1], SCB_LIST_NULL;
1270 cmp COMPLETE_DMA_SCB_HEAD[1], SCB_LIST_NULL jne add_dma_scb_tail;
1271 bmov COMPLETE_DMA_SCB_HEAD, SCBPTR, 2;
1272 bmov COMPLETE_DMA_SCB_TAIL, SCBPTR, 2 ret;
1273 add_dma_scb_tail:
1274 bmov REG0, SCBPTR, 2;
1275 bmov SCBPTR, COMPLETE_DMA_SCB_TAIL, 2;
1276 bmov SCB_NEXT_COMPLETE, REG0, 2;
1277 bmov COMPLETE_DMA_SCB_TAIL, REG0, 2 ret;
1278 END_CRITICAL;
1280 /*
1281 * Is it a disconnect message? Set a flag in the SCB to remind us
1282 * and await the bus going free. If this is an untagged transaction
1283 * store the SCB id for it in our untagged target table for lookup on
1284 * a reselection.
1285 */
1286 mesgin_disconnect:
1287 /*
1288 * If ATN is raised, we still want to give the target a message.
1289 * Perhaps there was a parity error on this last message byte
1290 * or we want to abort this command. Either way, the target
1291 * should take us to message out phase and then attempt to
1292 * disconnect again.
1293 * XXX - Wait for more testing.
1294 test SCSISIGI, ATNI jnz mesgin_done;
1295 */
1296 test SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT
1297 jnz mesgin_proto_violation;
1298 or SCB_CONTROL,DISCONNECTED;
1299 test SCB_CONTROL, TAG_ENB jnz await_busfree;
1300 queue_disc_scb:
1301 bmov REG0, SCBPTR, 2;
1302 INDEX_DISC_LIST(SAVED_SCSIID, SAVED_LUN);
1303 bmov DINDEX, SINDEX, 2;
1304 bmov DINDIR, REG0, 2;
1305 bmov SCBPTR, REG0, 2;
1306 /* FALLTHROUGH */
1307 await_busfree:
1308 and SIMODE1, ~ENBUSFREE;
1309 if ((ahd->bugs & AHD_BUSFREEREV_BUG) == 0) {
1310 /*
1311 * In the BUSFREEREV_BUG case, the
1312 * busfree status was cleared at the
1313 * beginning of the connection.
1314 */
1315 mvi CLRSINT1,CLRBUSFREE;
1316 }
1317 mov NONE, SCSIDAT; /* Ack the last byte */
1318 test MODE_PTR, ~(MK_MODE(M_DFF1, M_DFF1))
1319 jnz await_busfree_not_m_dff;
1320 SET_SRC_MODE M_DFF1;
1321 SET_DST_MODE M_DFF1;
1322 await_busfree_clrchn:
1323 mvi DFFSXFRCTL, CLRCHN;
1324 await_busfree_not_m_dff:
1325 /* clear target specific flags */
1326 mvi SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT;
1327 test SSTAT1,REQINIT|BUSFREE jz .;
1328 /*
1329 * We only set BUSFREE status once either a new
1330 * phase has been detected or we are really
1331 * BUSFREE. This allows the driver to know
1332 * that we are active on the bus even though
1333 * no identified transaction exists should a
1334 * timeout occur while awaiting busfree.
1335 */
1336 mvi LASTPHASE, P_BUSFREE;
1337 test SSTAT1, BUSFREE jnz idle_loop;
1338 SET_SEQINTCODE(MISSED_BUSFREE)
1341 /*
1342 * Save data pointers message:
1343 * Copying RAM values back to SCB, for Save Data Pointers message, but
1344 * only if we've actually been into a data phase to change them. This
1345 * protects against bogus data in scratch ram and the residual counts
1346 * since they are only initialized when we go into data_in or data_out.
1347 * Ack the message as soon as possible.
1348 */
1349 SET_SRC_MODE M_DFF1;
1350 SET_DST_MODE M_DFF1;
1351 mesgin_sdptrs:
1352 mov NONE,SCSIDAT; /*dummy read from latch to ACK*/
1353 test SEQ_FLAGS, DPHASE jz ITloop;
1354 call save_pointers;
1355 jmp ITloop;
1357 save_pointers:
1358 /*
1359 * If we are asked to save our position at the end of the
1360 * transfer, just mark us at the end rather than perform a
1361 * full save.
1362 */
1363 test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz save_pointers_full;
1364 or SCB_SGPTR, SG_LIST_NULL ret;
1366 save_pointers_full:
1367 /*
1368 * The SCB_DATAPTR becomes the current SHADDR.
1369 * All other information comes directly from our residual
1370 * state.
1371 */
1372 bmov SCB_DATAPTR, SHADDR, 8;
1373 bmov SCB_DATACNT, SCB_RESIDUAL_DATACNT, 8 ret;
1375 /*
1376 * Restore pointers message? Data pointers are recopied from the
1377 * SCB anytime we enter a data phase for the first time, so all
1378 * we need to do is clear the DPHASE flag and let the data phase
1379 * code do the rest. We also reset/reallocate the FIFO to make
1380 * sure we have a clean start for the next data or command phase.
1381 */
1382 mesgin_rdptrs:
1383 and SEQ_FLAGS, ~DPHASE;
1384 test MODE_PTR, ~(MK_MODE(M_DFF1, M_DFF1)) jnz msgin_rdptrs_get_fifo;
1385 mvi DFFSXFRCTL, RSTCHN|CLRSHCNT;
1386 SET_MODE(M_SCSI, M_SCSI)
1387 msgin_rdptrs_get_fifo:
1388 call allocate_fifo;
1389 jmp mesgin_done;
1391 phase_lock:
1392 if ((ahd->bugs & AHD_EARLY_REQ_BUG) != 0) {
1393 /*
1394 * Don't ignore persistent REQ assertions just because
1395 * they were asserted within the bus settle delay window.
1396 * This allows us to tolerate devices like the GEM318
1397 * that violate the SCSI spec. We are careful not to
1398 * count REQ while we are waiting for it to fall during
1399 * an async phase due to our asserted ACK. Each
1400 * sequencer instruction takes ~25ns, so the REQ must
1401 * last at least 100ns in order to be counted as a true
1402 * REQ.
1403 */
1404 test SCSIPHASE, 0xFF jnz phase_locked;
1405 test SCSISIGI, ACKI jnz phase_lock;
1406 test SCSISIGI, REQI jz phase_lock;
1407 test SCSIPHASE, 0xFF jnz phase_locked;
1408 test SCSISIGI, ACKI jnz phase_lock;
1409 test SCSISIGI, REQI jz phase_lock;
1410 phase_locked:
1411 } else {
1412 test SCSIPHASE, 0xFF jz .;
1413 }
1414 test SSTAT1, SCSIPERR jnz phase_lock;
1415 phase_lock_latch_phase:
1416 and LASTPHASE, PHASE_MASK, SCSISIGI ret;
1418 /*
1419 * Functions to read data in Automatic PIO mode.
1420 *
1421 * An ACK is not sent on input from the target until SCSIDATL is read from.
1422 * So we wait until SCSIDATL is latched (the usual way), then read the data
1423 * byte directly off the bus using SCSIBUSL. When we have pulled the ATN
1424 * line, or we just want to acknowledge the byte, then we do a dummy read
1425 * from SCISDATL. The SCSI spec guarantees that the target will hold the
1426 * data byte on the bus until we send our ACK.
1427 *
1428 * The assumption here is that these are called in a particular sequence,
1429 * and that REQ is already set when inb_first is called. inb_{first,next}
1430 * use the same calling convention as inb.
1431 */
1432 inb_next:
1433 mov NONE,SCSIDAT; /*dummy read from latch to ACK*/
1434 inb_next_wait:
1435 /*
1436 * If there is a parity error, wait for the kernel to
1437 * see the interrupt and prepare our message response
1438 * before continuing.
1439 */
1440 test SCSIPHASE, 0xFF jz .;
1441 test SSTAT1, SCSIPERR jnz inb_next_wait;
1442 inb_next_check_phase:
1443 and LASTPHASE, PHASE_MASK, SCSISIGI;
1444 cmp LASTPHASE, P_MESGIN jne mesgin_phasemis;
1445 inb_first:
1446 clr DINDEX[1];
1447 mov DINDEX,SINDEX;
1448 mov DINDIR,SCSIBUS ret; /*read byte directly from bus*/
1449 inb_last:
1450 mov NONE,SCSIDAT ret; /*dummy read from latch to ACK*/
1452 mk_mesg:
1453 mvi SCSISIGO, ATNO;
1454 mov MSG_OUT,SINDEX ret;
1456 SET_SRC_MODE M_DFF1;
1457 SET_DST_MODE M_DFF1;
1458 disable_ccsgen:
1459 test SG_STATE, FETCH_INPROG jz disable_ccsgen_fetch_done;
1460 clr CCSGCTL;
1461 disable_ccsgen_fetch_done:
1462 clr SG_STATE ret;
1464 service_fifo:
1465 /*
1466 * Do we have any prefetch left???
1467 */
1468 test SG_STATE, SEGS_AVAIL jnz idle_sg_avail;
1470 /*
1471 * Can this FIFO have access to the S/G cache yet?
1472 */
1473 test CCSGCTL, SG_CACHE_AVAIL jz return;
1475 /* Did we just finish fetching segs? */
1476 test CCSGCTL, CCSGDONE jnz idle_sgfetch_complete;
1478 /* Are we actively fetching segments? */
1479 test CCSGCTL, CCSGENACK jnz return;
1481 /*
1482 * Should the other FIFO get the S/G cache first? If
1483 * both FIFOs have been allocated since we last checked
1484 * any FIFO, it is important that we service a FIFO
1485 * that is not actively on the bus first. This guarantees
1486 * that a FIFO will be freed to handle snapshot requests for
1487 * any FIFO that is still on the bus. Chips with RTI do not
1488 * perform snapshots, so don't bother with this test there.
1489 */
1490 if ((ahd->features & AHD_RTI) == 0) {
1491 /*
1492 * If we're not still receiving SCSI data,
1493 * it is safe to allocate the S/G cache to
1494 * this FIFO.
1495 */
1496 test DFCNTRL, SCSIEN jz idle_sgfetch_start;
1498 /*
1499 * Switch to the other FIFO. Non-RTI chips
1500 * also have the "set mode" bug, so we must
1501 * disable interrupts during the switch.
1502 */
1503 mvi SEQINTCTL, INTVEC1DSL;
1504 xor MODE_PTR, MK_MODE(M_DFF1, M_DFF1);
1506 /*
1507 * If the other FIFO needs loading, then it
1508 * must not have claimed the S/G cache yet
1509 * (SG_CACHE_AVAIL would have been cleared in
1510 * the original FIFO mode and we test this above).
1511 * Return to the idle loop so we can process the
1512 * FIFO not currently on the bus first.
1513 */
1514 test SG_STATE, LOADING_NEEDED jz idle_sgfetch_okay;
1515 clr SEQINTCTL ret;
1516 idle_sgfetch_okay:
1517 xor MODE_PTR, MK_MODE(M_DFF1, M_DFF1);
1518 clr SEQINTCTL;
1519 }
1521 idle_sgfetch_start:
1522 /*
1523 * We fetch a "cacheline aligned" and sized amount of data
1524 * so we don't end up referencing a non-existent page.
1525 * Cacheline aligned is in quotes because the kernel will
1526 * set the prefetch amount to a reasonable level if the
1527 * cacheline size is unknown.
1528 */
1529 bmov SGHADDR, SCB_RESIDUAL_SGPTR, 4;
1530 mvi SGHCNT, SG_PREFETCH_CNT;
1531 if ((ahd->bugs & AHD_REG_SLOW_SETTLE_BUG) != 0) {
1532 /*
1533 * Need two instructions between "touches" of SGHADDR.
1534 */
1535 nop;
1536 }
1537 and SGHADDR[0], SG_PREFETCH_ALIGN_MASK, SCB_RESIDUAL_SGPTR;
1538 mvi CCSGCTL, CCSGEN|CCSGRESET;
1539 or SG_STATE, FETCH_INPROG ret;
1540 idle_sgfetch_complete:
1541 /*
1542 * Guard against SG_CACHE_AVAIL activating during sg fetch
1543 * request in the other FIFO.
1544 */
1545 test SG_STATE, FETCH_INPROG jz return;
1546 clr CCSGCTL;
1547 and CCSGADDR, SG_PREFETCH_ADDR_MASK, SCB_RESIDUAL_SGPTR;
1548 mvi SG_STATE, SEGS_AVAIL|LOADING_NEEDED;
1549 idle_sg_avail:
1550 /* Does the hardware have space for another SG entry? */
1551 test DFSTATUS, PRELOAD_AVAIL jz return;
1552 /*
1553 * On the A, preloading a segment before HDMAENACK
1554 * comes true can clobber the shadow address of the
1555 * first segment in the S/G FIFO. Wait until it is
1556 * safe to proceed.
1557 */
1558 if ((ahd->features & AHD_NEW_DFCNTRL_OPTS) == 0) {
1559 test DFCNTRL, HDMAENACK jz return;
1560 }
1561 if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0) {
1562 bmov HADDR, CCSGRAM, 8;
1563 } else {
1564 bmov HADDR, CCSGRAM, 4;
1565 }
1566 bmov HCNT, CCSGRAM, 3;
1567 bmov SCB_RESIDUAL_DATACNT[3], CCSGRAM, 1;
1568 if ((ahd->flags & AHD_39BIT_ADDRESSING) != 0) {
1569 and HADDR[4], SG_HIGH_ADDR_BITS, SCB_RESIDUAL_DATACNT[3];
1570 }
1571 if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0) {
1572 /* Skip 4 bytes of pad. */
1573 add CCSGADDR, 4;
1574 }
1575 sg_advance:
1576 clr A; /* add sizeof(struct scatter) */
1577 add SCB_RESIDUAL_SGPTR[0],SG_SIZEOF;
1578 adc SCB_RESIDUAL_SGPTR[1],A;
1579 adc SCB_RESIDUAL_SGPTR[2],A;
1580 adc SCB_RESIDUAL_SGPTR[3],A;
1581 mov SINDEX, SCB_RESIDUAL_SGPTR[0];
1582 test SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jz . + 3;
1583 or SINDEX, LAST_SEG;
1584 clr SG_STATE;
1585 mov SG_CACHE_PRE, SINDEX;
1586 if ((ahd->features & AHD_NEW_DFCNTRL_OPTS) != 0) {
1587 /*
1588 * Use SCSIENWRDIS so that SCSIEN is never
1589 * modified by this operation.
1590 */
1591 or DFCNTRL, PRELOADEN|HDMAEN|SCSIENWRDIS;
1592 } else {
1593 or DFCNTRL, PRELOADEN|HDMAEN;
1594 }
1595 /*
1596 * Do we have another segment in the cache?
1597 */
1598 add NONE, SG_PREFETCH_CNT_LIMIT, CCSGADDR;
1599 jnc return;
1600 and SG_STATE, ~SEGS_AVAIL ret;
1602 /*
1603 * Initialize the DMA address and counter from the SCB.
1604 */
1605 load_first_seg:
1606 bmov HADDR, SCB_DATAPTR, 11;
1607 and REG_ISR, ~SG_FULL_RESID, SCB_SGPTR[0];
1608 test SCB_DATACNT[3], SG_LAST_SEG jz . + 2;
1609 or REG_ISR, LAST_SEG;
1610 mov SG_CACHE_PRE, REG_ISR;
1611 mvi DFCNTRL, (PRELOADEN|SCSIEN|HDMAEN);
1612 /*
1613 * Since we've are entering a data phase, we will
1614 * rely on the SCB_RESID* fields. Initialize the
1615 * residual and clear the full residual flag.
1616 */
1617 and SCB_SGPTR[0], ~SG_FULL_RESID;
1618 bmov SCB_RESIDUAL_DATACNT[3], SCB_DATACNT[3], 5;
1619 /* If we need more S/G elements, tell the idle loop */
1620 test SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jnz . + 2;
1621 mvi SG_STATE, LOADING_NEEDED ret;
1622 clr SG_STATE ret;
1624 p_data_handle_xfer:
1625 call setjmp;
1626 test SG_STATE, LOADING_NEEDED jnz service_fifo;
1627 p_data_clear_handler:
1628 or LONGJMP_ADDR[1], INVALID_ADDR ret;
1630 p_data:
1631 test SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT jz p_data_allowed;
1632 SET_SEQINTCODE(PROTO_VIOLATION)
1633 p_data_allowed:
1635 test SEQ_FLAGS, DPHASE jz data_phase_initialize;
1637 /*
1638 * If we re-enter the data phase after going through another
1639 * phase, our transfer location has almost certainly been
1640 * corrupted by the interveining, non-data, transfers. Ask
1641 * the host driver to fix us up based on the transfer residual
1642 * unless we already know that we should be bitbucketing.
1643 */
1644 test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jnz p_data_bitbucket;
1645 SET_SEQINTCODE(PDATA_REINIT)
1646 jmp data_phase_inbounds;
1648 p_data_bitbucket:
1649 /*
1650 * Turn on `Bit Bucket' mode, wait until the target takes
1651 * us to another phase, and then notify the host.
1652 */
1653 mov SAVED_MODE, MODE_PTR;
1654 test MODE_PTR, ~(MK_MODE(M_DFF1, M_DFF1))
1655 jnz bitbucket_not_m_dff;
1656 /*
1657 * Ensure that any FIFO contents are cleared out and the
1658 * FIFO free'd prior to starting the BITBUCKET. BITBUCKET
1659 * doesn't discard data already in the FIFO.
1660 */
1661 mvi DFFSXFRCTL, RSTCHN|CLRSHCNT;
1662 SET_MODE(M_SCSI, M_SCSI)
1663 bitbucket_not_m_dff:
1664 or SXFRCTL1,BITBUCKET;
1665 /* Wait for non-data phase. */
1666 test SCSIPHASE, ~DATA_PHASE_MASK jz .;
1667 and SXFRCTL1, ~BITBUCKET;
1668 RESTORE_MODE(SAVED_MODE)
1669 SET_SRC_MODE M_DFF1;
1670 SET_DST_MODE M_DFF1;
1671 SET_SEQINTCODE(DATA_OVERRUN)
1672 jmp ITloop;
1674 data_phase_initialize:
1675 test SCB_SGPTR[0], SG_LIST_NULL jnz p_data_bitbucket;
1676 call load_first_seg;
1677 data_phase_inbounds:
1678 /* We have seen a data phase at least once. */
1679 or SEQ_FLAGS, DPHASE;
1680 mov SAVED_MODE, MODE_PTR;
1681 test SG_STATE, LOADING_NEEDED jz data_group_dma_loop;
1682 call p_data_handle_xfer;
1683 data_group_dma_loop:
1684 /*
1685 * The transfer is complete if either the last segment
1686 * completes or the target changes phase. Both conditions
1687 * will clear SCSIEN.
1688 */
1689 call idle_loop_service_fifos;
1690 call idle_loop_cchan;
1691 call idle_loop_gsfifo;
1692 RESTORE_MODE(SAVED_MODE)
1693 test DFCNTRL, SCSIEN jnz data_group_dma_loop;
1695 data_group_dmafinish:
1696 /*
1697 * The transfer has terminated either due to a phase
1698 * change, and/or the completion of the last segment.
1699 * We have two goals here. Do as much other work
1700 * as possible while the data fifo drains on a read
1701 * and respond as quickly as possible to the standard
1702 * messages (save data pointers/disconnect and command
1703 * complete) that usually follow a data phase.
1704 */
1705 call calc_residual;
1707 /*
1708 * Go ahead and shut down the DMA engine now.
1709 */
1710 test DFCNTRL, DIRECTION jnz data_phase_finish;
1711 data_group_fifoflush:
1712 if ((ahd->bugs & AHD_AUTOFLUSH_BUG) != 0) {
1713 or DFCNTRL, FIFOFLUSH;
1714 }
1715 /*
1716 * We have enabled the auto-ack feature. This means
1717 * that the controller may have already transferred
1718 * some overrun bytes into the data FIFO and acked them
1719 * on the bus. The only way to detect this situation is
1720 * to wait for LAST_SEG_DONE to come true on a completed
1721 * transfer and then test to see if the data FIFO is
1722 * non-empty. We know there is more data yet to transfer
1723 * if SG_LIST_NULL is not yet set, thus there cannot be
1724 * an overrun.
1725 */
1726 test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz data_phase_finish;
1727 test SG_CACHE_SHADOW, LAST_SEG_DONE jz .;
1728 test DFSTATUS, FIFOEMP jnz data_phase_finish;
1729 /* Overrun */
1730 jmp p_data;
1731 data_phase_finish:
1732 /*
1733 * If the target has left us in data phase, loop through
1734 * the dma code again. We will only loop if there is a
1735 * data overrun.
1736 */
1737 if ((ahd->flags & AHD_TARGETROLE) != 0) {
1738 test SSTAT0, TARGET jnz data_phase_done;
1739 }
1740 if ((ahd->flags & AHD_INITIATORROLE) != 0) {
1741 test SSTAT1, REQINIT jz .;
1742 test SCSIPHASE, DATA_PHASE_MASK jnz p_data;
1743 }
1745 data_phase_done:
1746 /* Kill off any pending prefetch */
1747 call disable_ccsgen;
1748 or LONGJMP_ADDR[1], INVALID_ADDR;
1750 if ((ahd->flags & AHD_TARGETROLE) != 0) {
1751 test SEQ_FLAGS, DPHASE_PENDING jz ITloop;
1752 /*
1753 and SEQ_FLAGS, ~DPHASE_PENDING;
1754 * For data-in phases, wait for any pending acks from the
1755 * initiator before changing phase. We only need to
1756 * send Ignore Wide Residue messages for data-in phases.
1757 test DFCNTRL, DIRECTION jz target_ITloop;
1758 test SSTAT1, REQINIT jnz .;
1759 test SCB_TASK_ATTRIBUTE, SCB_XFERLEN_ODD jz target_ITloop;
1760 SET_MODE(M_SCSI, M_SCSI)
1761 test NEGCONOPTS, WIDEXFER jz target_ITloop;
1762 */
1763 /*
1764 * Issue an Ignore Wide Residue Message.
1765 mvi P_MESGIN|BSYO call change_phase;
1766 mvi MSG_IGN_WIDE_RESIDUE call target_outb;
1767 mvi 1 call target_outb;
1768 jmp target_ITloop;
1769 */
1770 } else {
1771 jmp ITloop;
1772 }
1774 /*
1775 * We assume that, even though data may still be
1776 * transferring to the host, that the SCSI side of
1777 * the DMA engine is now in a static state. This
1778 * allows us to update our notion of where we are
1779 * in this transfer.
1780 *
1781 * If, by chance, we stopped before being able
1782 * to fetch additional segments for this transfer,
1783 * yet the last S/G was completely exhausted,
1784 * call our idle loop until it is able to load
1785 * another segment. This will allow us to immediately
1786 * pickup on the next segment on the next data phase.
1787 *
1788 * If we happened to stop on the last segment, then
1789 * our residual information is still correct from
1790 * the idle loop and there is no need to perform
1791 * any fixups.
1792 */
1793 residual_before_last_seg:
1794 test MDFFSTAT, SHVALID jnz sgptr_fixup;
1795 /*
1796 * Can never happen from an interrupt as the packetized
1797 * hardware will only interrupt us once SHVALID or
1798 * LAST_SEG_DONE.
1799 */
1800 call idle_loop_service_fifos;
1801 RESTORE_MODE(SAVED_MODE)
1802 /* FALLTHROUGH */
1803 calc_residual:
1804 test SG_CACHE_SHADOW, LAST_SEG jz residual_before_last_seg;
1805 /* Record if we've consumed all S/G entries */
1806 test MDFFSTAT, SHVALID jz . + 2;
1807 bmov SCB_RESIDUAL_DATACNT, SHCNT, 3 ret;
1808 or SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL ret;
1810 sgptr_fixup:
1811 /*
1812 * Fixup the residual next S/G pointer. The S/G preload
1813 * feature of the chip allows us to load two elements
1814 * in addition to the currently active element. We
1815 * store the bottom byte of the next S/G pointer in
1816 * the SG_CACHE_PTR register so we can restore the
1817 * correct value when the DMA completes. If the next
1818 * sg ptr value has advanced to the point where higher
1819 * bytes in the address have been affected, fix them
1820 * too.
1821 */
1822 test SG_CACHE_SHADOW, 0x80 jz sgptr_fixup_done;
1823 test SCB_RESIDUAL_SGPTR[0], 0x80 jnz sgptr_fixup_done;
1824 add SCB_RESIDUAL_SGPTR[1], -1;
1825 adc SCB_RESIDUAL_SGPTR[2], -1;
1826 adc SCB_RESIDUAL_SGPTR[3], -1;
1827 sgptr_fixup_done:
1828 and SCB_RESIDUAL_SGPTR[0], SG_ADDR_MASK, SG_CACHE_SHADOW;
1829 clr SCB_RESIDUAL_DATACNT[3]; /* We are not the last seg */
1830 bmov SCB_RESIDUAL_DATACNT, SHCNT, 3 ret;
1832 export timer_isr:
1833 call issue_cmdcmplt;
1834 mvi CLRSEQINTSTAT, CLRSEQ_SWTMRTO;
1835 if ((ahd->bugs & AHD_SET_MODE_BUG) != 0) {
1836 /*
1837 * In H2A4, the mode pointer is not saved
1838 * for intvec2, but is restored on iret.
1839 * This can lead to the restoration of a
1840 * bogus mode ptr. Manually clear the
1841 * intmask bits and do a normal return
1842 * to compensate.
1843 */
1844 and SEQINTCTL, ~(INTMASK2|INTMASK1) ret;
1845 } else {
1846 or SEQINTCTL, IRET ret;
1847 }
1849 export seq_isr:
1850 if ((ahd->features & AHD_RTI) == 0) {
1851 /*
1852 * On RevA Silicon, if the target returns us to data-out
1853 * after we have already trained for data-out, it is
1854 * possible for us to transition the free running clock to
1855 * data-valid before the required 100ns P1 setup time (8 P1
1856 * assertions in fast-160 mode). This will only happen if
1857 * this L-Q is a continuation of a data transfer for which
1858 * we have already prefetched data into our FIFO (LQ/Data
1859 * followed by LQ/Data for the same write transaction).
1860 * This can cause some target implementations to miss the
1861 * first few data transfers on the bus. We detect this
1862 * situation by noticing that this is the first data transfer
1863 * after an LQ (LQIWORKONLQ true), that the data transfer is
1864 * a continuation of a transfer already setup in our FIFO
1865 * (SAVEPTRS interrupt), and that the transaction is a write
1866 * (DIRECTION set in DFCNTRL). The delay is performed by
1867 * disabling SCSIEN until we see the first REQ from the
1868 * target.
1869 *
1870 * First instruction in an ISR cannot be a branch on
1871 * Rev A. Snapshot LQISTAT2 so the status is not missed
1872 * and deffer the test by one instruction.
1873 */
1874 mov REG_ISR, LQISTAT2;
1875 test REG_ISR, LQIWORKONLQ jz main_isr;
1876 test SEQINTSRC, SAVEPTRS jz main_isr;
1877 test LONGJMP_ADDR[1], INVALID_ADDR jz saveptr_active_fifo;
1878 /*
1879 * Switch to the active FIFO after clearing the snapshot
1880 * savepointer in the current FIFO. We do this so that
1881 * a pending CTXTDONE or SAVEPTR is visible in the active
1882 * FIFO. This status is the only way we can detect if we
1883 * have lost the race (e.g. host paused us) and our attempts
1884 * to disable the channel occurred after all REQs were
1885 * already seen and acked (REQINIT never comes true).
1886 */
1887 mvi DFFSXFRCTL, CLRCHN;
1888 xor MODE_PTR, MK_MODE(M_DFF1, M_DFF1);
1889 test DFCNTRL, DIRECTION jz interrupt_return;
1890 and DFCNTRL, ~SCSIEN;
1891 snapshot_wait_data_valid:
1892 test SEQINTSRC, (CTXTDONE|SAVEPTRS) jnz interrupt_return;
1893 test SSTAT1, REQINIT jz snapshot_wait_data_valid;
1894 snapshot_data_valid:
1895 or DFCNTRL, SCSIEN;
1896 or SEQINTCTL, IRET ret;
1897 snapshot_saveptr:
1898 mvi DFFSXFRCTL, CLRCHN;
1899 or SEQINTCTL, IRET ret;
1900 main_isr:
1901 }
1902 test SEQINTSRC, CFG4DATA jnz cfg4data_intr;
1903 test SEQINTSRC, CFG4ISTAT jnz cfg4istat_intr;
1904 test SEQINTSRC, SAVEPTRS jnz saveptr_intr;
1905 test SEQINTSRC, CFG4ICMD jnz cfg4icmd_intr;
1906 SET_SEQINTCODE(INVALID_SEQINT)
1908 /*
1909 * There are two types of save pointers interrupts:
1910 * The first is a snapshot save pointers where the current FIFO is not
1911 * active and contains a snapshot of the current poniter information.
1912 * This happens between packets in a stream for a single L_Q. Since we
1913 * are not performing a pointer save, we can safely clear the channel
1914 * so it can be used for other transactions. On RTI capable controllers,
1915 * where snapshots can, and are, disabled, the code to handle this type
1916 * of snapshot is not active.
1917 *
1918 * The second case is a save pointers on an active FIFO which occurs
1919 * if the target changes to a new L_Q or busfrees/QASes and the transfer
1920 * has a residual. This should occur coincident with a ctxtdone. We
1921 * disable the interrupt and allow our active routine to handle the
1922 * save.
1923 */
1924 saveptr_intr:
1925 if ((ahd->features & AHD_RTI) == 0) {
1926 test LONGJMP_ADDR[1], INVALID_ADDR jnz snapshot_saveptr;
1927 }
1928 saveptr_active_fifo:
1929 and SEQIMODE, ~ENSAVEPTRS;
1930 or SEQINTCTL, IRET ret;
1932 cfg4data_intr:
1933 test SCB_SGPTR[0], SG_LIST_NULL jnz pkt_handle_overrun_inc_use_count;
1934 call load_first_seg;
1935 call pkt_handle_xfer;
1936 inc SCB_FIFO_USE_COUNT;
1937 interrupt_return:
1938 or SEQINTCTL, IRET ret;
1940 cfg4istat_intr:
1941 call freeze_queue;
1942 add NONE, -13, SCB_CDB_LEN;
1943 jnc cfg4istat_have_sense_addr;
1944 test SCB_CDB_LEN, SCB_CDB_LEN_PTR jnz cfg4istat_have_sense_addr;
1945 /*
1946 * Host sets up address/count and enables transfer.
1947 */
1948 SET_SEQINTCODE(CFG4ISTAT_INTR)
1949 jmp cfg4istat_setup_handler;
1950 cfg4istat_have_sense_addr:
1951 bmov HADDR, SCB_SENSE_BUSADDR, 4;
1952 mvi HCNT[1], (AHD_SENSE_BUFSIZE >> 8);
1953 mvi SG_CACHE_PRE, LAST_SEG;
1954 mvi DFCNTRL, PRELOADEN|SCSIEN|HDMAEN;
1955 cfg4istat_setup_handler:
1956 /*
1957 * Status pkt is transferring to host.
1958 * Wait in idle loop for transfer to complete.
1959 * If a command completed before an attempted
1960 * task management function completed, notify the host.
1961 */
1962 test SCB_TASK_MANAGEMENT, 0xFF jz cfg4istat_no_taskmgmt_func;
1963 SET_SEQINTCODE(TASKMGMT_CMD_CMPLT_OKAY)
1964 cfg4istat_no_taskmgmt_func:
1965 call pkt_handle_status;
1966 or SEQINTCTL, IRET ret;
1968 cfg4icmd_intr:
1969 /*
1970 * In the case of DMAing a CDB from the host, the normal
1971 * CDB buffer is formatted with an 8 byte address followed
1972 * by a 1 byte count.
1973 */
1974 bmov HADDR[0], SCB_HOST_CDB_PTR, 9;
1975 mvi SG_CACHE_PRE, LAST_SEG;
1976 mvi DFCNTRL, (PRELOADEN|SCSIEN|HDMAEN);
1977 call pkt_handle_cdb;
1978 or SEQINTCTL, IRET ret;
1980 /*
1981 * See if the target has gone on in this context creating an
1982 * overrun condition. For the write case, the hardware cannot
1983 * ack bytes until data are provided. So, if the target begins
1984 * another packet without changing contexts, implying we are
1985 * not sitting on a packet boundary, we are in an overrun
1986 * situation. For the read case, the hardware will continue to
1987 * ack bytes into the FIFO, and may even ack the last overrun packet
1988 * into the FIFO. If the FIFO should become non-empty, we are in
1989 * a read overrun case.
1990 */
1991 #define check_overrun \
1992 /* Not on a packet boundary. */ \
1993 test MDFFSTAT, DLZERO jz pkt_handle_overrun; \
1994 test DFSTATUS, FIFOEMP jz pkt_handle_overrun
1996 pkt_handle_xfer:
1997 test SG_STATE, LOADING_NEEDED jz pkt_last_seg;
1998 call setjmp;
1999 test SEQINTSRC, SAVEPTRS jnz pkt_saveptrs;
2000 test SCSIPHASE, ~DATA_PHASE_MASK jz . + 2;
2001 test SCSISIGO, ATNO jnz . + 2;
2002 test SSTAT2, NONPACKREQ jz pkt_service_fifo;
2003 /*
2004 * Defer handling of this NONPACKREQ until we
2005 * can be sure it pertains to this FIFO. SAVEPTRS
2006 * will not be asserted if the NONPACKREQ is for us,
2007 * so we must simulate it if shadow is valid. If
2008 * shadow is not valid, keep running this FIFO until we
2009 * have satisfied the transfer by loading segments and
2010 * waiting for either shadow valid or last_seg_done.
2011 */
2012 test MDFFSTAT, SHVALID jnz pkt_saveptrs;
2013 pkt_service_fifo:
2014 test SG_STATE, LOADING_NEEDED jnz service_fifo;
2015 pkt_last_seg:
2016 call setjmp;
2017 test SEQINTSRC, SAVEPTRS jnz pkt_saveptrs;
2018 test SG_CACHE_SHADOW, LAST_SEG_DONE jnz pkt_last_seg_done;
2019 test SCSIPHASE, ~DATA_PHASE_MASK jz . + 2;
2020 test SCSISIGO, ATNO jnz . + 2;
2021 test SSTAT2, NONPACKREQ jz return;
2022 test MDFFSTAT, SHVALID jz return;
2023 /* FALLTHROUGH */
2025 /*
2026 * Either a SAVEPTRS interrupt condition is pending for this FIFO
2027 * or we have a pending NONPACKREQ for this FIFO. We differentiate
2028 * between the two by capturing the state of the SAVEPTRS interrupt
2029 * prior to clearing this status and executing the common code for
2030 * these two cases.
2031 */
2032 pkt_saveptrs:
2033 BEGIN_CRITICAL;
2034 if ((ahd->bugs & AHD_AUTOFLUSH_BUG) != 0) {
2035 or DFCNTRL, FIFOFLUSH;
2036 }
2037 mov REG0, SEQINTSRC;
2038 call calc_residual;
2039 call save_pointers;
2040 mvi CLRSEQINTSRC, CLRSAVEPTRS;
2041 call disable_ccsgen;
2042 or SEQIMODE, ENSAVEPTRS;
2043 test DFCNTRL, DIRECTION jnz pkt_saveptrs_check_status;
2044 test DFSTATUS, FIFOEMP jnz pkt_saveptrs_check_status;
2045 /*
2046 * Keep a handler around for this FIFO until it drains
2047 * to the host to guarantee that we don't complete the
2048 * command to the host before the data arrives.
2049 */
2050 pkt_saveptrs_wait_fifoemp:
2051 call setjmp;
2052 test DFSTATUS, FIFOEMP jz return;
2053 pkt_saveptrs_check_status:
2054 or LONGJMP_ADDR[1], INVALID_ADDR;
2055 test REG0, SAVEPTRS jz unexpected_nonpkt_phase;
2056 dec SCB_FIFO_USE_COUNT;
2057 test SCB_CONTROL, STATUS_RCVD jnz pkt_complete_scb_if_fifos_idle;
2058 mvi DFFSXFRCTL, CLRCHN ret;
2060 /*
2061 * LAST_SEG_DONE status has been seen in the current FIFO.
2062 * This indicates that all of the allowed data for this
2063 * command has transferred across the SCSI and host buses.
2064 * Check for overrun and see if we can complete this command.
2065 */
2066 pkt_last_seg_done:
2067 /*
2068 * Mark transfer as completed.
2069 */
2070 or SCB_SGPTR, SG_LIST_NULL;
2072 /*
2073 * Wait for the current context to finish to verify that
2074 * no overrun condition has occurred.
2075 */
2076 test SEQINTSRC, CTXTDONE jnz pkt_ctxt_done;
2077 call setjmp;
2078 pkt_wait_ctxt_done_loop:
2079 test SEQINTSRC, CTXTDONE jnz pkt_ctxt_done;
2080 /*
2081 * A sufficiently large overrun or a NONPACKREQ may
2082 * prevent CTXTDONE from ever asserting, so we must
2083 * poll for these statuses too.
2084 */
2085 check_overrun;
2086 test SSTAT2, NONPACKREQ jz return;
2087 test SEQINTSRC, CTXTDONE jz unexpected_nonpkt_phase;
2088 /* FALLTHROUGH */
2090 pkt_ctxt_done:
2091 check_overrun;
2092 or LONGJMP_ADDR[1], INVALID_ADDR;
2093 /*
2094 * If status has been received, it is safe to skip
2095 * the check to see if another FIFO is active because
2096 * LAST_SEG_DONE has been observed. However, we check
2097 * the FIFO anyway since it costs us only one extra
2098 * instruction to leverage common code to perform the
2099 * SCB completion.
2100 */
2101 dec SCB_FIFO_USE_COUNT;
2102 test SCB_CONTROL, STATUS_RCVD jnz pkt_complete_scb_if_fifos_idle;
2103 mvi DFFSXFRCTL, CLRCHN ret;
2104 END_CRITICAL;
2106 /*
2107 * Must wait until CDB xfer is over before issuing the
2108 * clear channel.
2109 */
2110 pkt_handle_cdb:
2111 call setjmp;
2112 test SG_CACHE_SHADOW, LAST_SEG_DONE jz return;
2113 or LONGJMP_ADDR[1], INVALID_ADDR;
2114 mvi DFFSXFRCTL, CLRCHN ret;
2116 /*
2117 * Watch over the status transfer. Our host sense buffer is
2118 * large enough to take the maximum allowed status packet.
2119 * None-the-less, we must still catch and report overruns to
2120 * the host. Additionally, properly catch unexpected non-packet
2121 * phases that are typically caused by CRC errors in status packet
2122 * transmission.
2123 */
2124 pkt_handle_status:
2125 call setjmp;
2126 test SG_CACHE_SHADOW, LAST_SEG_DONE jnz pkt_status_check_overrun;
2127 test SEQINTSRC, CTXTDONE jz pkt_status_check_nonpackreq;
2128 test SG_CACHE_SHADOW, LAST_SEG_DONE jnz pkt_status_check_overrun;
2129 pkt_status_IU_done:
2130 if ((ahd->bugs & AHD_AUTOFLUSH_BUG) != 0) {
2131 or DFCNTRL, FIFOFLUSH;
2132 }
2133 test DFSTATUS, FIFOEMP jz return;
2134 BEGIN_CRITICAL;
2135 or LONGJMP_ADDR[1], INVALID_ADDR;
2136 mvi SCB_SCSI_STATUS, STATUS_PKT_SENSE;
2137 or SCB_CONTROL, STATUS_RCVD;
2138 jmp pkt_complete_scb_if_fifos_idle;
2139 END_CRITICAL;
2140 pkt_status_check_overrun:
2141 /*
2142 * Status PKT overruns are uncerimoniously recovered with a
2143 * bus reset. If we've overrun, let the host know so that
2144 * recovery can be performed.
2145 *
2146 * LAST_SEG_DONE has been observed. If either CTXTDONE or
2147 * a NONPACKREQ phase change have occurred and the FIFO is
2148 * empty, there is no overrun.
2149 */
2150 test DFSTATUS, FIFOEMP jz pkt_status_report_overrun;
2151 test SEQINTSRC, CTXTDONE jz . + 2;
2152 test DFSTATUS, FIFOEMP jnz pkt_status_IU_done;
2153 test SCSIPHASE, ~DATA_PHASE_MASK jz return;
2154 test DFSTATUS, FIFOEMP jnz pkt_status_check_nonpackreq;
2155 pkt_status_report_overrun:
2156 SET_SEQINTCODE(STATUS_OVERRUN)
2157 /* SEQUENCER RESTARTED */
2158 pkt_status_check_nonpackreq:
2159 /*
2160 * CTXTDONE may be held off if a NONPACKREQ is associated with
2161 * the current context. If a NONPACKREQ is observed, decide
2162 * if it is for the current context. If it is for the current
2163 * context, we must defer NONPACKREQ processing until all data
2164 * has transferred to the host.
2165 */
2166 test SCSIPHASE, ~DATA_PHASE_MASK jz return;
2167 test SCSISIGO, ATNO jnz . + 2;
2168 test SSTAT2, NONPACKREQ jz return;
2169 test SEQINTSRC, CTXTDONE jnz pkt_status_IU_done;
2170 test DFSTATUS, FIFOEMP jz return;
2171 /*
2172 * The unexpected nonpkt phase handler assumes that any
2173 * data channel use will have a FIFO reference count. It
2174 * turns out that the status handler doesn't need a references
2175 * count since the status received flag, and thus completion
2176 * processing, cannot be set until the handler is finished.
2177 * We increment the count here to make the nonpkt handler
2178 * happy.
2179 */
2180 inc SCB_FIFO_USE_COUNT;
2181 /* FALLTHROUGH */
2183 /*
2184 * Nonpackreq is a polled status. It can come true in three situations:
2185 * we have received an L_Q, we have sent one or more L_Qs, or there is no
2186 * L_Q context associated with this REQ (REQ occurs immediately after a
2187 * (re)selection). Routines that know that the context responsible for this
2188 * nonpackreq call directly into unexpected_nonpkt_phase. In the case of the
2189 * top level idle loop, we exhaust all active contexts prior to determining that
2190 * we simply do not have the full I_T_L_Q for this phase.
2191 */
2192 unexpected_nonpkt_phase_find_ctxt:
2193 /*
2194 * This nonpackreq is most likely associated with one of the tags
2195 * in a FIFO or an outgoing LQ. Only treat it as an I_T only
2196 * nonpackreq if we've cleared out the FIFOs and handled any
2197 * pending SELDO.
2198 */
2199 SET_SRC_MODE M_SCSI;
2200 SET_DST_MODE M_SCSI;
2201 and A, FIFO1FREE|FIFO0FREE, DFFSTAT;
2202 cmp A, FIFO1FREE|FIFO0FREE jne return;
2203 test SSTAT0, SELDO jnz return;
2204 mvi SCBPTR[1], SCB_LIST_NULL;
2205 unexpected_nonpkt_phase:
2206 test MODE_PTR, ~(MK_MODE(M_DFF1, M_DFF1))
2207 jnz unexpected_nonpkt_mode_cleared;
2208 SET_SRC_MODE M_DFF0;
2209 SET_DST_MODE M_DFF0;
2210 or LONGJMP_ADDR[1], INVALID_ADDR;
2211 dec SCB_FIFO_USE_COUNT;
2212 mvi DFFSXFRCTL, CLRCHN;
2213 unexpected_nonpkt_mode_cleared:
2214 mvi CLRSINT2, CLRNONPACKREQ;
2215 if ((ahd->bugs & AHD_BUSFREEREV_BUG) != 0) {
2216 /*
2217 * Test to ensure that the bus has not
2218 * already gone free prior to clearing
2219 * any stale busfree status. This avoids
2220 * a window whereby a busfree just after
2221 * a selection could be missed.
2222 */
2223 test SCSISIGI, BSYI jz . + 2;
2224 mvi CLRSINT1,CLRBUSFREE;
2225 or SIMODE1, ENBUSFREE;
2226 }
2227 test SCSIPHASE, ~(MSG_IN_PHASE|MSG_OUT_PHASE) jnz illegal_phase;
2228 SET_SEQINTCODE(ENTERING_NONPACK)
2229 jmp ITloop;
2231 illegal_phase:
2232 SET_SEQINTCODE(ILLEGAL_PHASE)
2233 jmp ITloop;
2235 /*
2236 * We have entered an overrun situation. If we have working
2237 * BITBUCKET, flip that on and let the hardware eat any overrun
2238 * data. Otherwise use an overrun buffer in the host to simulate
2239 * BITBUCKET.
2240 */
2241 pkt_handle_overrun_inc_use_count:
2242 inc SCB_FIFO_USE_COUNT;
2243 pkt_handle_overrun:
2244 SET_SEQINTCODE(CFG4OVERRUN)
2245 call freeze_queue;
2246 if ((ahd->bugs & AHD_PKT_BITBUCKET_BUG) == 0) {
2247 or DFFSXFRCTL, DFFBITBUCKET;
2248 SET_SRC_MODE M_DFF1;
2249 SET_DST_MODE M_DFF1;
2250 } else {
2251 call load_overrun_buf;
2252 mvi DFCNTRL, (HDMAEN|SCSIEN|PRELOADEN);
2253 }
2254 call setjmp;
2255 if ((ahd->bugs & AHD_PKT_BITBUCKET_BUG) != 0) {
2256 test DFSTATUS, PRELOAD_AVAIL jz overrun_load_done;
2257 call load_overrun_buf;
2258 or DFCNTRL, PRELOADEN;
2259 overrun_load_done:
2260 test SEQINTSRC, CTXTDONE jnz pkt_overrun_end;
2261 } else {
2262 test DFFSXFRCTL, DFFBITBUCKET jz pkt_overrun_end;
2263 }
2264 test SSTAT2, NONPACKREQ jz return;
2265 pkt_overrun_end:
2266 or SCB_RESIDUAL_SGPTR, SG_OVERRUN_RESID;
2267 test SEQINTSRC, CTXTDONE jz unexpected_nonpkt_phase;
2268 dec SCB_FIFO_USE_COUNT;
2269 or LONGJMP_ADDR[1], INVALID_ADDR;
2270 test SCB_CONTROL, STATUS_RCVD jnz pkt_complete_scb_if_fifos_idle;
2271 mvi DFFSXFRCTL, CLRCHN ret;
2273 if ((ahd->bugs & AHD_PKT_BITBUCKET_BUG) != 0) {
2274 load_overrun_buf:
2275 /*
2276 * Load a dummy segment if preload space is available.
2277 */
2278 mov HADDR[0], SHARED_DATA_ADDR;
2279 add HADDR[1], PKT_OVERRUN_BUFOFFSET, SHARED_DATA_ADDR[1];
2280 mov ACCUM_SAVE, A;
2281 clr A;
2282 adc HADDR[2], A, SHARED_DATA_ADDR[2];
2283 adc HADDR[3], A, SHARED_DATA_ADDR[3];
2284 mov A, ACCUM_SAVE;
2285 bmov HADDR[4], ALLZEROS, 4;
2286 /* PKT_OVERRUN_BUFSIZE is a multiple of 256 */
2287 clr HCNT[0];
2288 mvi HCNT[1], ((PKT_OVERRUN_BUFSIZE >> 8) & 0xFF);
2289 clr HCNT[2] ret;
2290 }