aic7xxx.seq revision 13313
1/*+M*********************************************************************** 2 *Adaptec 274x/284x/294x device driver for Linux and FreeBSD. 3 * 4 *Copyright (c) 1994 John Aycock 5 * The University of Calgary Department of Computer Science. 6 * All rights reserved. 7 * 8 *Modifications/enhancements: 9 * Copyright (c) 1994, 1995 Justin Gibbs. All rights reserved. 10 * 11 *Redistribution and use in source and binary forms, with or without 12 *modification, are permitted provided that the following conditions 13 *are met: 14 *1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions, and the following disclaimer. 16 *2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 *3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of Calgary 22 * Department of Computer Science and its contributors. 23 *4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 *THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 28 *ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 *IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 *ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 31 *FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 *DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 *OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 *HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 *LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 *OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 *SUCH DAMAGE. 38 * 39 *FreeBSD, Twin, Wide, 2 command per target support, tagged queuing and other 40 *optimizations provided by Justin T. Gibbs (gibbs@FreeBSD.org) 41 * 42 *-M************************************************************************/ 43 44VERSION AIC7XXX_SEQ_VER "$Id: aic7xxx.seq,v 1.26 1996/01/05 16:11:49 gibbs Exp $" 45 46#include "../../dev/aic7xxx/aic7xxx_reg.h" 47 48/* 49 * We can't just use ACCUM in the sequencer code because it 50 * must be treated specially by the assembler, and it currently 51 * looks for the symbol 'A'. This is the only register defined 52 * the assembler's symbol space. 53 */ 54A = ACCUM 55 56/* After starting the selection hardware, we return to the "poll_for_work" 57 * loop so that we can check for reconnecting targets as well as for our 58 * selection to complete just in case the reselection wins bus arbitration. 59 * The problem with this is that we must keep track of the SCB that we've 60 * already pulled from the QINFIFO and started the selection on just in case 61 * the reselection wins so that we can retry the selection at a later time. 62 * This problem cannot be resolved by holding a single entry in scratch 63 * ram since a reconnecting target can request sense and this will create 64 * yet another SCB waiting for selection. The solution used here is to 65 * use byte 31 of the SCB as a psuedo-next pointer and to thread a list 66 * of SCBs that are awaiting selection. Since 0-0xfe are valid SCB offsets, 67 * SCB_LIST_NULL is 0xff which is out of range. The kernel driver must 68 * add an entry to this list everytime a request sense occurs. The sequencer 69 * will automatically consume the entries. 70 */ 71 72/* 73 * Initialize any state idle loop state here. This code is executed on 74 * startup and after every bus free. 75 */ 76start: 77 mvi SCSISEQ,ENRSELI /* Always allow reselection */ 78poll_for_work: 79 /* 80 * Are we a twin channel device? 81 * For fairness, we check the other bus first, 82 * since we just finished a transaction on the 83 * current channel. 84 */ 85 test FLAGS,TWIN_BUS jz start2 86 xor SBLKCTL,SELBUSB /* Toggle to the other bus */ 87 test SSTAT0,SELDI jnz reselect 88 xor SBLKCTL,SELBUSB /* Toggle to the original bus */ 89start2: 90 test SSTAT0,SELDI jnz reselect 91 cmp WAITING_SCBH,SCB_LIST_NULL jne start_waiting 92 test QINCNT,0xff jz poll_for_work 93 94/* We have at least one queued SCB now and we don't have any 95 * SCBs in the list of SCBs awaiting selection. Set the SCB 96 * pointer from the FIFO so we see the right bank of SCB 97 * registers. 98 */ 99 mov SCBPTR,QINFIFO 100 101/* 102 * If the control byte of this SCB has the NEEDDMA flag set, we have 103 * yet to DMA it from host memory 104 */ 105 106test SCB_CONTROL,NEEDDMA jz test_busy 107 clr HCNT2 108 clr HCNT1 109 mvi HCNT0,SCB_SIZEOF 110 111 mvi DINDEX,HADDR 112 mvi SCB_PHYSADDR call bcopy_4 113 114 mvi DFCNTRL,0xd /* HDMAEN|DIRECTION|FIFORESET */ 115 116/* 117 * Wait for DMA from host memory to data FIFO to complete, then disable 118 * DMA and wait for it to acknowledge that it's off. 119 */ 120 call dma_finish 121 122/* Copy the SCB from the FIFO to the SCBARRAY */ 123 124 mvi DINDEX, SCBARRAY 125 call bcopy_5_dfdat 126 call bcopy_7_dfdat 127 call bcopy_7_dfdat 128 call bcopy_7_dfdat 129 130/* 131 * See if there is not already an active SCB for this target. This code 132 * locks out on a per target basis instead of target/lun. Although this 133 * is not ideal for devices that have multiple luns active at the same 134 * time, it is faster than looping through all SCB's looking for active 135 * commands. It may be benificial to make findscb a more general procedure 136 * to see if the added cost of the search is negligible. This code also 137 * assumes that the kernel driver will clear the active flags on board 138 * initialization, board reset, and a target SELTO. Tagged commands 139 * don't set the active bits since you can have more than queue more 140 * than one command at a time. We do, however, look to see if there 141 * are any non-tagged I/Os in progress, and requeue the command if 142 * there are. Tagged and non-tagged commands cannot be mixed to a 143 * single target. 144 */ 145 146test_busy: 147 mov FUNCTION1,SCB_TCL 148 mov A,FUNCTION1 149 test SCB_TCL,0x88 jz test_a /* Id < 8 && A channel */ 150 151 test ACTIVE_B,A jnz requeue 152 test SCB_CONTROL,TAG_ENB jnz start_scb 153 /* Mark the current target as busy */ 154 or ACTIVE_B,A 155 jmp start_scb 156 157/* Place the currently active SCB back on the queue for later processing */ 158requeue: 159 mov QINFIFO, SCBPTR 160 jmp poll_for_work 161 162/* 163 * Pull the first entry off of the waiting for selection list 164 * We don't have to "test_busy" because only transactions that 165 * have passed that test can be in the waiting_scb list. 166 */ 167start_waiting: 168 mov SCBPTR,WAITING_SCBH 169 jmp start_scb2 170 171test_a: 172 test ACTIVE_A,A jnz requeue 173 test SCB_CONTROL,TAG_ENB jnz start_scb 174 /* Mark the current target as busy */ 175 or ACTIVE_A,A 176 177start_scb: 178 mov SCB_NEXT_WAITING,WAITING_SCBH 179 mov WAITING_SCBH, SCBPTR 180start_scb2: 181 and SINDEX,0xf7,SBLKCTL /* Clear the channel select bit */ 182 and A,0x08,SCB_TCL /* Get new channel bit */ 183 or SINDEX,A 184 mov SBLKCTL,SINDEX /* select channel */ 185 mov SCB_TCL call initialize_scsiid 186 187/* 188 * Enable selection phase as an initiator, and do automatic ATN 189 * after the selection. We do this now so that we can overlap the 190 * rest of our work to set up this target with the arbitration and 191 * selection bus phases. 192 */ 193start_selection: 194 mvi SCSISEQ,0x58 /* ENSELO|ENAUTOATNO|ENRSELI */ 195 196/* 197 * As soon as we get a successful selection, the target should go 198 * into the message out phase since we have ATN asserted. Prepare 199 * the message to send. 200 * 201 * Messages are stored in scratch RAM starting with a length byte 202 * followed by the message itself. 203 */ 204 test SCB_CMDLEN,0xff jnz mk_identify /* 0 Length Command? */ 205 206/* 207 * The kernel has sent us an SCB with no command attached. This implies 208 * that the kernel wants to send a message of some sort to this target, 209 * so we interrupt the driver, allow it to fill the message buffer, and 210 * then go back into the arbitration loop 211 */ 212 mvi INTSTAT,AWAITING_MSG 213 jmp wait_for_selection 214 215mk_identify: 216 and A,DISCENB,SCB_CONTROL /* mask off disconnect privledge */ 217 218 and SINDEX,0x7,SCB_TCL /* lun */ 219 or SINDEX,A /* or in disconnect privledge */ 220 or SINDEX,MSG_IDENTIFY call mk_mesg /* IDENTIFY message */ 221 222 test SCB_CONTROL,0xb0 jz !message /* WDTR, SDTR or TAG?? */ 223/* 224 * Tag Message if Tag enabled in SCB control block. Use SCBPTR as the tag 225 * value 226 */ 227 228mk_tag: 229 mvi DINDEX, MSG1 230 test SCB_CONTROL,TAG_ENB jz mk_tag_done 231 and A,0x23,SCB_CONTROL 232 mov DINDIR,A 233 mov DINDIR,SCBPTR 234 235 add MSG_LEN,COMP_MSG0,DINDEX /* update message length */ 236 237mk_tag_done: 238 239 mov DINDEX call mk_dtr /* build DTR message if needed */ 240 241!message: 242wait_for_selection: 243 test SSTAT0,SELDO jnz select 244 test SSTAT0,SELDI jz wait_for_selection 245 246/* 247 * Reselection has been initiated by a target. Make a note that we've been 248 * reselected, but haven't seen an IDENTIFY message from the target 249 * yet. 250 */ 251reselect: 252 clr MSG_LEN /* Don't have anything in the mesg buffer */ 253 mov SELID call initialize_scsiid 254 mvi SAVED_TCL, 0xff /* 255 * Fill with an imposible value so we 256 * don't get false hits for a tag 257 * without an identify. 258 */ 259 and FLAGS,0x03 /* clear target specific flags */ 260 or FLAGS,RESELECTED 261 jmp select2 262 263/* 264 * After the selection, remove this SCB from the "waiting for selection" 265 * list. This is achieved by simply moving our "next" pointer into 266 * WAITING_SCBH. Our next pointer will be set to null the next time this 267 * SCB is used, so don't bother with it now. 268 */ 269select: 270 and FLAGS,0x03 /* Clear target flags */ 271 or SCB_CONTROL,NEEDDMA 272 273 /* 274 * Some drives will issue a simple tag message during 275 * a tagged selection if they are immediately ready 276 * to handle the command without a disconnect. Ensure 277 * that SAVED_TCL (used in get_tag) is inialized correctly 278 * during a selection for this reason. 279 */ 280 mov SAVED_TCL, SCB_TCL 281 mov WAITING_SCBH,SCB_NEXT_WAITING 282select2: 283/* 284 * Set CLRCHN here before the target has entered a data transfer mode - 285 * with synchronous SCSI, if you do it later, you blow away some 286 * data in the SCSI FIFO that the target has already sent to you. 287 */ 288 clr SIGSTATE 289 290 or SXFRCTL0,CLRCHN 291/* 292 * Initialize SCSIRATE with the appropriate value for this target. 293 */ 294 call ndx_dtr 295 mov SCSIRATE,SINDIR 296 297 mvi SCSISEQ,ENAUTOATNP /* 298 * ATN on parity errors 299 * for "in" phases 300 */ 301 mvi CLRSINT1,CLRBUSFREE 302 mvi CLRSINT0,0x60 /* CLRSELDI|CLRSELDO */ 303 304/* 305 * Main loop for information transfer phases. If BSY is false, then 306 * we have a bus free condition, expected or not. Otherwise, wait 307 * for the target to assert REQ before checking MSG, C/D and I/O 308 * for the bus phase. 309 * 310 */ 311ITloop: 312 test SSTAT1,BUSFREE jnz p_busfree 313 test SSTAT1,REQINIT jz ITloop 314 315 and A,PHASE_MASK,SCSISIGI 316 317 mov A call scsisig 318 cmp ALLZEROS,A je p_dataout 319 cmp A,P_DATAIN je p_datain 320 cmp A,P_COMMAND je p_command 321 cmp A,P_MESGOUT je p_mesgout 322 cmp A,P_STATUS je p_status 323 cmp A,P_MESGIN je p_mesgin 324 325 mvi INTSTAT,BAD_PHASE /* unknown phase - signal driver */ 326 327p_dataout: 328 mvi DMAPARAMS,0x7d /* 329 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 330 * DIRECTION|FIFORESET 331 */ 332 jmp data_phase_init 333 334/* 335 * If we re-enter the data phase after going through another phase, the 336 * STCNT may have been cleared, so restore it from the residual field. 337 */ 338data_phase_reinit: 339 mvi DINDEX, STCNT 340 mvi SCB_RESID_DCNT call bcopy_3 341 jmp data_phase_loop 342 343p_datain: 344 mvi DMAPARAMS,0x79 /* 345 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 346 * !DIRECTION|FIFORESET 347 */ 348data_phase_init: 349 call assert 350 351 test FLAGS, DPHASE jnz data_phase_reinit 352 call sg_scb2ram 353 or FLAGS, DPHASE /* We have seen a data phase */ 354 355data_phase_loop: 356/* If we are the last SG block, don't set wideodd. */ 357 cmp SG_COUNT,0x01 jne data_phase_wideodd 358 and DMAPARAMS, 0xbf /* Turn off WIDEODD */ 359data_phase_wideodd: 360 mov DMAPARAMS call dma 361 362/* Exit if we had an underrun */ 363 test SSTAT0,SDONE jz data_phase_finish /* underrun STCNT != 0 */ 364 365/* 366 * Advance the scatter-gather pointers if needed 367 */ 368sg_advance: 369 dec SG_COUNT /* one less segment to go */ 370 371 test SG_COUNT, 0xff jz data_phase_finish /* Are we done? */ 372 373 clr A /* add sizeof(struct scatter) */ 374 add SG_NEXT0,SG_SIZEOF,SG_NEXT0 375 adc SG_NEXT1,A,SG_NEXT1 376 adc SG_NEXT2,A,SG_NEXT2 377 adc SG_NEXT3,A,SG_NEXT3 378 379/* 380 * Load a struct scatter and set up the data address and length. 381 * If the working value of the SG count is nonzero, then 382 * we need to load a new set of values. 383 * 384 * This, like all DMA's, assumes a little-endian host data storage. 385 */ 386sg_load: 387 clr HCNT2 388 clr HCNT1 389 mvi HCNT0,SG_SIZEOF 390 391 mvi DINDEX,HADDR 392 mvi SG_NEXT call bcopy_4 393 394 mvi DFCNTRL,0xd /* HDMAEN|DIRECTION|FIFORESET */ 395 396/* 397 * Wait for DMA from host memory to data FIFO to complete, then disable 398 * DMA and wait for it to acknowledge that it's off. 399 */ 400 call dma_finish 401 402/* 403 * Copy data from FIFO into SCB data pointer and data count. This assumes 404 * that the struct scatterlist has this structure (this and sizeof(struct 405 * scatterlist) == 12 are asserted in aic7xxx.c): 406 * 407 * struct scatterlist { 408 * char *address; four bytes, little-endian order 409 * ... four bytes, ignored 410 * unsigned short length; two bytes, little-endian order 411 * } 412 * 413 * 414 * Not in FreeBSD. the scatter list entry is only 8 bytes. 415 * 416 * struct ahc_dma_seg { 417 * physaddr addr; four bytes, little-endian order 418 * long len; four bytes, little endian order 419 * }; 420 */ 421 422/* 423 * For Linux, we must throw away four bytes since there is a 32bit gap 424 * in the middle of a struct scatterlist 425 */ 426#ifdef LINUX 427 call bcopy_4_dfdat 428 mov NONE,DFDAT 429 mov NONE,DFDAT 430 mov NONE,DFDAT 431 mov NONE,DFDAT 432 call bcopy_3_dfdat /* Only support 24 bit length. */ 433#else 434/* 435 * For FreeBSD, just copy it wholesale 436 */ 437 mvi DINDEX,HADDR 438 call bcopy_7_dfdat 439#endif 440 441/* Load STCNT as well. It is a mirror of HCNT */ 442 mvi DINDEX,STCNT 443 mvi HCNT call bcopy_3 444 test SSTAT1,PHASEMIS jz data_phase_loop 445 446data_phase_finish: 447/* 448 * After a DMA finishes, save the SG and STCNT residuals back into the SCB 449 * We use STCNT instead of HCNT, since it's a reflection of how many bytes 450 * were transferred on the SCSI (as opposed to the host) bus. 451 */ 452 mvi DINDEX,SCB_RESID_DCNT 453 mvi STCNT call bcopy_3 454 mov SCB_RESID_SGCNT, SG_COUNT 455 jmp ITloop 456 457/* 458 * Command phase. Set up the DMA registers and let 'er rip - the 459 * two bytes after the SCB SCSI_cmd_length are zeroed by the driver, 460 * so we can copy those three bytes directly into HCNT. 461 */ 462p_command: 463 call assert 464 465/* 466 * Load HADDR and HCNT. We can do this in one bcopy since they are neighbors 467 */ 468 mvi DINDEX,HADDR 469 mvi SCB_CMDPTR call bcopy_7 470 471 mvi DINDEX,STCNT 472 mvi SCB_CMDLEN call bcopy_3 473 474 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 475 # DIRECTION|FIFORESET 476 jmp ITloop 477 478/* 479 * Status phase. Wait for the data byte to appear, then read it 480 * and store it into the SCB. 481 */ 482p_status: 483 mvi SCB_TARGET_STATUS call inb_first 484 jmp mesgin_done 485 486/* 487 * Message out phase. If there is no active message, but the target 488 * took us into this phase anyway, build a no-op message and send it. 489 */ 490p_mesgout: 491 test MSG_LEN, 0xff jnz p_mesgout_start 492 mvi MSG_NOP call mk_mesg /* build NOP message */ 493 494p_mesgout_start: 495/* 496 * Set up automatic PIO transfer from MSG0. Bit 3 in 497 * SXFRCTL0 (SPIOEN) is already on. 498 */ 499 mvi SINDEX,MSG0 500 mov DINDEX,MSG_LEN 501 502/* 503 * When target asks for a byte, drop ATN if it's the last one in 504 * the message. Otherwise, keep going until the message is exhausted. 505 * 506 * Keep an eye out for a phase change, in case the target issues 507 * a MESSAGE REJECT. 508 */ 509p_mesgout_loop: 510 test SSTAT1,PHASEMIS jnz p_mesgout_phasemis 511 test SSTAT0,SPIORDY jz p_mesgout_loop 512 cmp DINDEX,1 jne p_mesgout_outb /* last byte? */ 513 mvi CLRSINT1,CLRATNO /* drop ATN */ 514p_mesgout_outb: 515 or SXFRCTL0, CLRSTCNT 516 mvi STCNT0, 1 517 dec DINDEX 518 mov SCSIDATL,SINDIR 519p_mesgout_outb_wait: 520 test SSTAT0,SDONE jz p_mesgout_outb_wait 521 522p_mesgout4: 523 test DINDEX,0xff jnz p_mesgout_loop 524 525/* 526 * If the next bus phase after ATN drops is a message out, it means 527 * that the target is requesting that the last message(s) be resent. 528 */ 529p_mesgout_snoop: 530 test SSTAT1,BUSFREE jnz p_mesgout_done 531 test SSTAT1,REQINIT jz p_mesgout_snoop 532 533 test SSTAT1,PHASEMIS jnz p_mesgout_done 534 535 or SINDEX,0x10,SIGSTATE /* turn on ATNO */ 536 call scsisig /* ATNO - re-assert ATN */ 537 538 jmp ITloop 539 540p_mesgout_phasemis: 541 mvi CLRSINT1,CLRATNO /* Be sure turn ATNO off */ 542p_mesgout_done: 543 clr MSG_LEN /* no active msg */ 544 jmp ITloop 545 546/* 547 * Message in phase. Bytes are read using Automatic PIO mode. 548 */ 549p_mesgin: 550 mvi A call inb_first /* read the 1st message byte */ 551 mov REJBYTE,A /* save it for the driver */ 552 553 test A,MSG_IDENTIFY jnz mesgin_identify 554 cmp A,MSG_DISCONNECT je mesgin_disconnect 555 cmp A,MSG_SDPTRS je mesgin_sdptrs 556 cmp ALLZEROS,A je mesgin_complete 557 cmp A,MSG_RDPTRS je mesgin_rdptrs 558 cmp A,MSG_EXTENDED je mesgin_extended 559 cmp A,MSG_REJECT je mesgin_reject 560 561rej_mesgin: 562/* 563 * We have no idea what this message in is, and there's no way 564 * to pass it up to the kernel, so we issue a message reject and 565 * hope for the best. Since we're now using manual PIO mode to 566 * read in the message, there should no longer be a race condition 567 * present when we assert ATN. In any case, rejection should be a 568 * rare occurrence - signal the driver when it happens. 569 */ 570 or SINDEX,0x10,SIGSTATE /* turn on ATNO */ 571 call scsisig 572 mvi INTSTAT,SEND_REJECT /* let driver know */ 573 574 mvi MSG_REJECT call mk_mesg 575 576mesgin_done: 577 call inb_last /*ack & turn auto PIO back on*/ 578 jmp ITloop 579 580 581mesgin_complete: 582/* 583 * We got a "command complete" message, so put the SCB pointer 584 * into the Queue Out, and trigger a completion interrupt. 585 * Check status for non zero return and interrupt driver if needed 586 * This allows the driver to interpret errors only when they occur 587 * instead of always uploading the scb. If the status is SCSI_CHECK, 588 * the driver will download a new scb requesting sense to replace 589 * the old one, modify the "waiting for selection" SCB list and set 590 * RETURN_1 to 0x80. If RETURN_1 is set to 0x80 the sequencer imediately 591 * jumps to main loop where it will run down the waiting SCB list. 592 * If the kernel driver does not wish to request sense, it need 593 * only clear RETURN_1, and the command is allowed to complete. We don't 594 * bother to post to the QOUTFIFO in the error case since it would require 595 * extra work in the kernel driver to ensure that the entry was removed 596 * before the command complete code tried processing it. 597 * 598 * First check for residuals 599 */ 600 test SCB_RESID_SGCNT,0xff jz check_status 601/* 602 * If we have a residual count, interrupt and tell the host. Other 603 * alternatives are to pause the sequencer on all command completes (yuck), 604 * dma the resid directly to the host (slick, we may have space to do it now) 605 * or have the sequencer pause itself when it encounters a non-zero resid 606 * (unecessary pause just to flag the command -yuck-, but takes one instruction 607 * and since it shouldn't happen that often is good enough for our purposes). 608 */ 609resid: 610 mvi INTSTAT,RESIDUAL 611 612check_status: 613 test SCB_TARGET_STATUS,0xff jz status_ok /* Good Status? */ 614 mvi INTSTAT,BAD_STATUS /* let driver know */ 615 cmp RETURN_1, SEND_SENSE jne status_ok 616 jmp mesgin_done 617 618status_ok: 619/* First, mark this target as free. */ 620 test SCB_CONTROL,TAG_ENB jnz test_immediate /* 621 * Tagged commands 622 * don't busy the 623 * target. 624 */ 625 mov FUNCTION1,SCB_TCL 626 mov A,FUNCTION1 627 test SCB_TCL,0x88 jz clear_a 628 xor ACTIVE_B,A 629 jmp test_immediate 630 631clear_a: 632 xor ACTIVE_A,A 633 634test_immediate: 635 test SCB_CMDLEN,0xff jnz complete /* Immediate message complete */ 636/* 637 * Pause the sequencer until the driver gets around to handling the command 638 * complete. This is so that any action that might require carefull timing 639 * with the completion of this command can occur. 640 */ 641 mvi INTSTAT,IMMEDDONE 642 jmp start 643complete: 644 mov QOUTFIFO,SCBPTR 645 mvi INTSTAT,CMDCMPLT 646 jmp mesgin_done 647 648 649/* 650 * Is it an extended message? We only support the synchronous and wide data 651 * transfer request messages, which will probably be in response to 652 * WDTR or SDTR message outs from us. If it's not SDTR or WDTR, reject it - 653 * apparently this can be done after any message in byte, according 654 * to the SCSI-2 spec. 655 */ 656mesgin_extended: 657 mvi ARG_1 call inb_next /* extended message length */ 658 mvi A call inb_next /* extended message code */ 659 660 cmp A,MSG_SDTR je p_mesginSDTR 661 cmp A,MSG_WDTR je p_mesginWDTR 662 jmp rej_mesgin 663 664p_mesginWDTR: 665 cmp ARG_1,2 jne rej_mesgin /* extended mesg length=2 */ 666 mvi ARG_1 call inb_next /* Width of bus */ 667 mvi INTSTAT,WDTR_MSG /* let driver know */ 668 test RETURN_1,0xff jz mesgin_done /* Do we need to send WDTR? */ 669 cmp RETURN_1,SEND_REJ je rej_mesgin /* 670 * Bus width was too large 671 * Reject it. 672 */ 673 674/* We didn't initiate the wide negotiation, so we must respond to the request */ 675 and RETURN_1,0x7f /* Clear the SEND_WDTR Flag */ 676 mvi DINDEX,MSG0 677 mvi MSG0 call mk_wdtr /* build WDTR message */ 678 or SINDEX,0x10,SIGSTATE /* turn on ATNO */ 679 call scsisig 680 jmp mesgin_done 681 682p_mesginSDTR: 683 cmp ARG_1,3 jne rej_mesgin /* extended mesg length=3 */ 684 mvi ARG_1 call inb_next /* xfer period */ 685 mvi A call inb_next /* REQ/ACK offset */ 686 mvi INTSTAT,SDTR_MSG /* call driver to convert */ 687 688 test RETURN_1,0xff jz mesgin_done /* Do we need to mk_sdtr/rej */ 689 cmp RETURN_1,SEND_REJ je rej_mesgin /* 690 * Requested SDTR too small 691 * Reject it. 692 */ 693 mvi DINDEX, MSG0 694 mvi MSG0 call mk_sdtr 695 or SINDEX,0x10,SIGSTATE /* turn on ATNO */ 696 call scsisig 697 jmp mesgin_done 698 699/* 700 * Is it a disconnect message? Set a flag in the SCB to remind us 701 * and await the bus going free. 702 */ 703mesgin_disconnect: 704 or SCB_CONTROL,DISCONNECTED 705 jmp mesgin_done 706 707/* 708 * Save data pointers message? Copy working values into the SCB, 709 * usually in preparation for a disconnect. 710 */ 711mesgin_sdptrs: 712 call sg_ram2scb 713 jmp mesgin_done 714 715/* 716 * Restore pointers message? Data pointers are recopied from the 717 * SCB anytime we enter a data phase for the first time, so all 718 * we need to do is clear the DPHASE flag and let the data phase 719 * code do the rest. 720 */ 721mesgin_rdptrs: 722 and FLAGS,0xfb /* 723 * !DPHASE we'll reload them 724 * the next time through 725 */ 726 jmp mesgin_done 727 728/* 729 * Identify message? For a reconnecting target, this tells us the lun 730 * that the reconnection is for - find the correct SCB and switch to it, 731 * clearing the "disconnected" bit so we don't "find" it by accident later. 732 */ 733mesgin_identify: 734 test A,0x78 jnz rej_mesgin /*!DiscPriv|!LUNTAR|!Reserved*/ 735 736 and A,0x07 /* lun in lower three bits */ 737 or SAVED_TCL,A,SELID 738 and SAVED_TCL,0xf7 739 and A,SELBUSB,SBLKCTL /* B Channel?? */ 740 or SAVED_TCL,A 741 call inb_last /* ACK */ 742 743/* 744 * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message. 745 * If we get one, we use the tag returned to switch to the proper 746 * SCB. Otherwise, we just use the findSCB method. 747 */ 748snoop_tag_loop: 749 test SSTAT1,BUSFREE jnz use_findSCB 750 test SSTAT1,REQINIT jz snoop_tag_loop 751 test SSTAT1,PHASEMIS jnz use_findSCB 752 mvi A call inb_first 753 cmp A,MSG_SIMPLE_TAG je get_tag 754use_findSCB: 755 mov ALLZEROS call findSCB /* Have to search */ 756setup_SCB: 757 and SCB_CONTROL,0xfb /* clear disconnect bit in SCB */ 758 or FLAGS,IDENTIFY_SEEN /* make note of IDENTIFY */ 759 jmp ITloop 760get_tag: 761 mvi ARG_1 call inb_next /* tag value */ 762/* 763 * See if the tag is in range. The tag is < SCBCOUNT if we add 764 * the complement of SCBCOUNT to the incomming tag and there is 765 * no carry. 766 */ 767 mov A,COMP_SCBCOUNT 768 add SINDEX,A,ARG_1 769 jc abort_tag 770 771/* 772 * Ensure that the SCB the tag points to is for an SCB transaction 773 * to the reconnecting target. 774 */ 775 mov SCBPTR,ARG_1 776 mov A,SAVED_TCL 777 cmp SCB_TCL,A jne abort_tag 778 test SCB_CONTROL,TAG_ENB jz abort_tag 779 call inb_last /* Ack Successful tag */ 780 jmp setup_SCB 781abort_tag: 782 or SINDEX,0x10,SIGSTATE /* turn on ATNO */ 783 call scsisig 784 mvi INTSTAT,ABORT_TAG /* let driver know */ 785 mvi 0xd call mk_mesg /* ABORT TAG message */ 786 jmp mesgin_done 787 788/* 789 * Message reject? Let the kernel driver handle this. If we have an 790 * outstanding WDTR or SDTR negotiation, assume that it's a response from 791 * the target selecting 8bit or asynchronous transfer, otherwise just ignore 792 * it since we have no clue what it pertains to. 793 */ 794mesgin_reject: 795 mvi INTSTAT, REJECT_MSG 796 jmp mesgin_done 797 798/* 799 * [ ADD MORE MESSAGE HANDLING HERE ] 800 */ 801 802/* 803 * Bus free phase. It might be useful to interrupt the device 804 * driver if we aren't expecting this. For now, make sure that 805 * ATN isn't being asserted and look for a new command. 806 */ 807p_busfree: 808 mvi CLRSINT1,CLRATNO 809 810/* 811 * if this is an immediate command, perform a psuedo command complete to 812 * notify the driver. 813 */ 814 test SCB_CMDLEN,0xff jz status_ok 815 jmp start 816 817/* 818 * Instead of a generic bcopy routine that requires an argument, we unroll 819 * the cases that are actually used, and call them explicitly. This 820 * not only reduces the overhead of doing a bcopy, but ends up saving space 821 * in the program since you don't have to put the argument into the accumulator 822 * before the call. Both functions expect DINDEX to contain the destination 823 * address and SINDEX to contain the source address. 824 */ 825bcopy_7: 826 mov DINDIR,SINDIR 827 mov DINDIR,SINDIR 828bcopy_5: 829 mov DINDIR,SINDIR 830bcopy_4: 831 mov DINDIR,SINDIR 832bcopy_3: 833 mov DINDIR,SINDIR 834 mov DINDIR,SINDIR 835 mov DINDIR,SINDIR ret 836 837bcopy_7_dfdat: 838 mov DINDIR,DFDAT 839 mov DINDIR,DFDAT 840bcopy_5_dfdat: 841 mov DINDIR,DFDAT 842bcopy_4_dfdat: 843 mov DINDIR,DFDAT 844bcopy_3_dfdat: 845 mov DINDIR,DFDAT 846 mov DINDIR,DFDAT 847 mov DINDIR,DFDAT ret 848 849/* 850 * Locking the driver out, build a one-byte message passed in SINDEX 851 * if there is no active message already. SINDEX is returned intact. 852 */ 853mk_mesg: 854 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 855 test MSG_LEN,0xff jz mk_mesg1 /* Should always succeed */ 856 857 /* 858 * Hmmm. For some reason the mesg buffer is in use. 859 * Tell the driver. It should look at SINDEX to find 860 * out what we wanted to use the buffer for and resolve 861 * the conflict. 862 */ 863 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 864 mvi INTSTAT,MSG_BUFFER_BUSY ret 865 866mk_mesg1: 867 mvi MSG_LEN,1 /* length = 1 */ 868 mov MSG0,SINDEX /* 1-byte message */ 869 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 870 871/* 872 * Functions to read data in Automatic PIO mode. 873 * 874 * According to Adaptec's documentation, an ACK is not sent on input from 875 * the target until SCSIDATL is read from. So we wait until SCSIDATL is 876 * latched (the usual way), then read the data byte directly off the bus 877 * using SCSIBUSL. When we have pulled the ATN line, or we just want to 878 * acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI 879 * spec guarantees that the target will hold the data byte on the bus until 880 * we send our ACK. 881 * 882 * The assumption here is that these are called in a particular sequence, 883 * and that REQ is already set when inb_first is called. inb_{first,next} 884 * use the same calling convention as inb. 885 */ 886 887inb_next: 888 call inb_last 889inb_first: 890 test SSTAT1,PHASEMIS jnz mesgin_phasemis 891 test SSTAT0,SPIORDY jz inb_first /* wait for next byte */ 892 mov DINDEX,SINDEX 893 mov DINDIR,SCSIBUSL ret /*read byte directly from bus*/ 894inb_last: 895 or SXFRCTL0,CLRSTCNT 896 mvi STCNT0,0x01 897 mov NONE,SCSIDATL /*dummy read from latch to ACK*/ 898inb_last_wait: 899 test SSTAT0,SDONE jz inb_last_wait /* Wait for completion */ 900 ret 901 902mesgin_phasemis: 903/* 904 * We expected to receive another byte, but the target changed phase 905 */ 906 mvi INTSTAT, MSGIN_PHASEMIS 907 jmp ITloop 908 909/* 910 * DMA data transfer. HADDR and HCNT must be loaded first, and 911 * SINDEX should contain the value to load DFCNTRL with - 0x3d for 912 * host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared 913 * during initialization. 914 */ 915dma: 916 mov DFCNTRL,SINDEX 917dma1: 918 test SSTAT0,DMADONE jnz dma3 919 test SSTAT1,PHASEMIS jz dma1 /* ie. underrun */ 920 921/* 922 * We will be "done" DMAing when the transfer count goes to zero, or 923 * the target changes the phase (in light of this, it makes sense that 924 * the DMA circuitry doesn't ACK when PHASEMIS is active). If we are 925 * doing a SCSI->Host transfer, the data FIFO should be flushed auto- 926 * magically on STCNT=0 or a phase change, so just wait for FIFO empty 927 * status. 928 */ 929dma3: 930 test SINDEX,DIRECTION jnz dma5 931dma4: 932 test DFSTATUS,FIFOEMP jz dma4 933 934/* 935 * Now shut the DMA enables off and make sure that the DMA enables are 936 * actually off first lest we get an ILLSADDR. 937 */ 938dma5: 939 /* disable DMA, but maintain WIDEODD */ 940 and A, WIDEODD, SINDEX 941 mov DFCNTRL, A 942dma6: 943 test DFCNTRL,0x38 jnz dma6 /* SCSIENACK|SDMAENACK|HDMAENACK */ 944 945 ret 946 947dma_finish: 948 test DFSTATUS,HDONE jz dma_finish 949 950 clr DFCNTRL /* disable DMA */ 951dma_finish2: 952 test DFCNTRL,HDMAENACK jnz dma_finish2 953 ret 954 955/* 956 * Common SCSI initialization for selection and reselection. Expects 957 * the target SCSI ID to be in the upper four bits of SINDEX, and A's 958 * contents are stomped on return. 959 */ 960initialize_scsiid: 961 and SINDEX,0xf0 /* Get target ID */ 962 and A,0x0f,SCSIID 963 or SINDEX,A 964 mov SCSIID,SINDEX ret 965 966/* 967 * Assert that if we've been reselected, then we've seen an IDENTIFY 968 * message. 969 */ 970assert: 971 test FLAGS,RESELECTED jz return /* reselected? */ 972 test FLAGS,IDENTIFY_SEEN jnz return /* seen IDENTIFY? */ 973 974 mvi INTSTAT,NO_IDENT ret /* no - cause a kernel panic */ 975 976/* 977 * Locate the SCB matching the target ID/channel/lun in SAVED_TCL and switch 978 * the SCB to it. Have the kernel print a warning message if it can't be 979 * found, and generate an ABORT message to the target. SINDEX should be 980 * cleared on call. 981 */ 982findSCB: 983 mov A,SAVED_TCL 984 mov SCBPTR,SINDEX /* switch to new SCB */ 985 cmp SCB_TCL,A jne findSCB1 /* target ID/channel/lun match? */ 986 test SCB_CONTROL,DISCONNECTED jz findSCB1 /*should be disconnected*/ 987 ret 988 989findSCB1: 990 inc SINDEX 991 mov A,SCBCOUNT 992 cmp SINDEX,A jne findSCB 993 994 mvi INTSTAT,NO_MATCH /* not found - signal kernel */ 995 mvi MSG_ABORT call mk_mesg /* ABORT message */ 996 997 or SINDEX,0x10,SIGSTATE /* assert ATNO */ 998 call scsisig 999 ret 1000/* 1001 * Make a working copy of the scatter-gather parameters from the SCB. 1002 */ 1003sg_scb2ram: 1004 mvi DINDEX,HADDR 1005 mvi SCB_DATAPTR call bcopy_7 1006 1007 mvi DINDEX,STCNT 1008 mvi SCB_DATACNT call bcopy_3 1009 1010 mov SG_COUNT,SCB_SGCOUNT 1011 1012 mvi DINDEX,SG_NEXT 1013 mvi SCB_SGPTR call bcopy_4 1014 ret 1015 1016/* 1017 * Copying RAM values back to SCB, for Save Data Pointers message, but 1018 * only if we've actually been into a data phase to change them. This 1019 * protects against bogus data in scratch ram and the residual counts 1020 * since they are only initialized when we go into data_in or data_out. 1021 */ 1022sg_ram2scb: 1023 test FLAGS, DPHASE jz return 1024 mov SCB_SGCOUNT,SG_COUNT 1025 1026 mvi DINDEX,SCB_SGPTR 1027 mvi SG_NEXT call bcopy_4 1028 1029 mvi DINDEX,SCB_DATAPTR 1030 mvi SHADDR call bcopy_4 1031 1032/* 1033 * Use the residual number since STCNT is corrupted by any message transfer 1034 */ 1035 mvi SCB_RESID_DCNT call bcopy_3 1036 ret 1037 1038/* 1039 * Add the array base TARG_SCRATCH to the target offset (the target address 1040 * is in SCSIID), and return the result in SINDEX. The accumulator 1041 * contains the 3->8 decoding of the target ID on return. 1042 */ 1043ndx_dtr: 1044 shr A,SCSIID,4 1045 test SBLKCTL,SELBUSB jz ndx_dtr_2 1046 or A,0x08 /* Channel B entries add 8 */ 1047ndx_dtr_2: 1048 add SINDEX,TARG_SCRATCH,A 1049 1050 mov FUNCTION1,SCSIID /* 3-bit target address decode */ 1051 mov A,FUNCTION1 ret 1052 1053/* 1054 * If we need to negotiate transfer parameters, build the WDTR or SDTR message 1055 * starting at the address passed in SINDEX. DINDEX is modified on return. 1056 * The SCSI-II spec requires that Wide negotiation occur first and you can 1057 * only negotiat one or the other at a time otherwise in the event of a message 1058 * reject, you wouldn't be able to tell which message was the culpret. 1059 */ 1060mk_dtr: 1061 test SCB_CONTROL,0x90 jz return /* NEEDWDTR|NEEDSDTR */ 1062 test SCB_CONTROL,NEEDWDTR jnz mk_wdtr_16bit 1063 or FLAGS, MAXOFFSET /* Force an offset of 15 or 8 if WIDE */ 1064 1065mk_sdtr: 1066 mvi DINDIR,1 /* extended message */ 1067 mvi DINDIR,3 /* extended message length = 3 */ 1068 mvi DINDIR,1 /* SDTR code */ 1069 call sdtr_to_rate 1070 mov DINDIR,RETURN_1 /* REQ/ACK transfer period */ 1071 test FLAGS, MAXOFFSET jnz mk_sdtr_max_offset 1072 and DINDIR,0x0f,SINDIR /* Sync Offset */ 1073 1074mk_sdtr_done: 1075 add MSG_LEN,COMP_MSG0,DINDEX ret /* update message length */ 1076 1077mk_sdtr_max_offset: 1078/* 1079 * We're initiating sync negotiation, so request the max offset we can (15 or 8) 1080 */ 1081 xor FLAGS, MAXOFFSET 1082 1083 /* Talking to a WIDE device? */ 1084 test SCSIRATE, WIDEXFER jnz wmax_offset 1085 mvi DINDIR, MAX_OFFSET_8BIT 1086 jmp mk_sdtr_done 1087 1088wmax_offset: 1089 mvi DINDIR, MAX_OFFSET_16BIT 1090 jmp mk_sdtr_done 1091 1092mk_wdtr_16bit: 1093 mvi ARG_1,BUS_16_BIT 1094mk_wdtr: 1095 mvi DINDIR,1 /* extended message */ 1096 mvi DINDIR,2 /* extended message length = 2 */ 1097 mvi DINDIR,3 /* WDTR code */ 1098 mov DINDIR,ARG_1 /* bus width */ 1099 1100 add MSG_LEN,COMP_MSG0,DINDEX ret /* update message length */ 1101 1102/* 1103 * Set SCSI bus control signal state. This also saves the last-written 1104 * value into a location where the higher-level driver can read it - if 1105 * it has to send an ABORT or RESET message, then it needs to know this 1106 * so it can assert ATN without upsetting SCSISIGO. The new value is 1107 * expected in SINDEX. Change the actual state last to avoid contention 1108 * from the driver. 1109 */ 1110scsisig: 1111 mov SIGSTATE,SINDEX 1112 mov SCSISIGO,SINDEX ret 1113 1114sdtr_to_rate: 1115 call ndx_dtr /* index scratch space for target */ 1116 shr A,SINDIR,0x4 1117 dec SINDEX /* Preserve SINDEX */ 1118 and A,0x7 1119 clr RETURN_1 1120sdtr_to_rate_loop: 1121 test A,0x0f jz sdtr_to_rate_done 1122 add RETURN_1,0x19 1123 dec A 1124 jmp sdtr_to_rate_loop 1125sdtr_to_rate_done: 1126 shr RETURN_1,0x2 1127 add RETURN_1,0x19 1128 test SXFRCTL0,ULTRAEN jz return 1129 shr RETURN_1,0x1 1130return: 1131 ret 1132