aic7xxx.seq revision 13251
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 1.24 1995/11/07 05:31:28 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 SSTAT0,SPIORDY jz p_mesgout_loop 511 cmp DINDEX,1 jne p_mesgout_outb /* last byte? */ 512 mvi CLRSINT1,CLRATNO /* drop ATN */ 513p_mesgout_outb: 514 test SSTAT1,PHASEMIS jnz p_mesgout_phasemis 515 dec DINDEX 516 mov SCSIDATL,SINDIR 517p_mesgout4: 518 test DINDEX,0xff jnz p_mesgout_loop 519 520/* 521 * If the next bus phase after ATN drops is a message out, it means 522 * that the target is requesting that the last message(s) be resent. 523 */ 524p_mesgout_snoop: 525 test SSTAT1,BUSFREE jnz p_mesgout_done 526 test SSTAT1,REQINIT jz p_mesgout_snoop 527 528 test SSTAT1,PHASEMIS jnz p_mesgout_done 529 530 or SINDEX,0x10,SIGSTATE /* turn on ATNO */ 531 call scsisig /* ATNO - re-assert ATN */ 532 533 jmp ITloop 534 535p_mesgout_phasemis: 536 mvi CLRSINT1,CLRATNO /* Be sure turn ATNO off */ 537p_mesgout_done: 538 clr MSG_LEN /* no active msg */ 539 jmp ITloop 540 541/* 542 * Message in phase. Bytes are read using Automatic PIO mode. 543 */ 544p_mesgin: 545 mvi A call inb_first /* read the 1st message byte */ 546 mov REJBYTE,A /* save it for the driver */ 547 548 test A,MSG_IDENTIFY jnz mesgin_identify 549 cmp A,MSG_DISCONNECT je mesgin_disconnect 550 cmp A,MSG_SDPTRS je mesgin_sdptrs 551 cmp ALLZEROS,A je mesgin_complete 552 cmp A,MSG_RDPTRS je mesgin_rdptrs 553 cmp A,MSG_EXTENDED je mesgin_extended 554 cmp A,MSG_REJECT je mesgin_reject 555 556rej_mesgin: 557/* 558 * We have no idea what this message in is, and there's no way 559 * to pass it up to the kernel, so we issue a message reject and 560 * hope for the best. Since we're now using manual PIO mode to 561 * read in the message, there should no longer be a race condition 562 * present when we assert ATN. In any case, rejection should be a 563 * rare occurrence - signal the driver when it happens. 564 */ 565 or SINDEX,0x10,SIGSTATE /* turn on ATNO */ 566 call scsisig 567 mvi INTSTAT,SEND_REJECT /* let driver know */ 568 569 mvi MSG_REJECT call mk_mesg 570 571mesgin_done: 572 call inb_last /*ack & turn auto PIO back on*/ 573 jmp ITloop 574 575 576mesgin_complete: 577/* 578 * We got a "command complete" message, so put the SCB pointer 579 * into the Queue Out, and trigger a completion interrupt. 580 * Check status for non zero return and interrupt driver if needed 581 * This allows the driver to interpret errors only when they occur 582 * instead of always uploading the scb. If the status is SCSI_CHECK, 583 * the driver will download a new scb requesting sense to replace 584 * the old one, modify the "waiting for selection" SCB list and set 585 * RETURN_1 to 0x80. If RETURN_1 is set to 0x80 the sequencer imediately 586 * jumps to main loop where it will run down the waiting SCB list. 587 * If the kernel driver does not wish to request sense, it need 588 * only clear RETURN_1, and the command is allowed to complete. We don't 589 * bother to post to the QOUTFIFO in the error case since it would require 590 * extra work in the kernel driver to ensure that the entry was removed 591 * before the command complete code tried processing it. 592 * 593 * First check for residuals 594 */ 595 test SCB_RESID_SGCNT,0xff jz check_status 596/* 597 * If we have a residual count, interrupt and tell the host. Other 598 * alternatives are to pause the sequencer on all command completes (yuck), 599 * dma the resid directly to the host (slick, we may have space to do it now) 600 * or have the sequencer pause itself when it encounters a non-zero resid 601 * (unecessary pause just to flag the command -yuck-, but takes one instruction 602 * and since it shouldn't happen that often is good enough for our purposes). 603 */ 604resid: 605 mvi INTSTAT,RESIDUAL 606 607check_status: 608 test SCB_TARGET_STATUS,0xff jz status_ok /* Good Status? */ 609 mvi INTSTAT,BAD_STATUS /* let driver know */ 610 cmp RETURN_1, SEND_SENSE jne status_ok 611 jmp mesgin_done 612 613status_ok: 614/* First, mark this target as free. */ 615 test SCB_CONTROL,TAG_ENB jnz test_immediate /* 616 * Tagged commands 617 * don't busy the 618 * target. 619 */ 620 mov FUNCTION1,SCB_TCL 621 mov A,FUNCTION1 622 test SCB_TCL,0x88 jz clear_a 623 xor ACTIVE_B,A 624 jmp test_immediate 625 626clear_a: 627 xor ACTIVE_A,A 628 629test_immediate: 630 test SCB_CMDLEN,0xff jnz complete /* Immediate message complete */ 631/* 632 * Pause the sequencer until the driver gets around to handling the command 633 * complete. This is so that any action that might require carefull timing 634 * with the completion of this command can occur. 635 */ 636 mvi INTSTAT,IMMEDDONE 637 jmp start 638complete: 639 mov QOUTFIFO,SCBPTR 640 mvi INTSTAT,CMDCMPLT 641 jmp mesgin_done 642 643 644/* 645 * Is it an extended message? We only support the synchronous and wide data 646 * transfer request messages, which will probably be in response to 647 * WDTR or SDTR message outs from us. If it's not SDTR or WDTR, reject it - 648 * apparently this can be done after any message in byte, according 649 * to the SCSI-2 spec. 650 */ 651mesgin_extended: 652 mvi ARG_1 call inb_next /* extended message length */ 653 mvi A call inb_next /* extended message code */ 654 655 cmp A,MSG_SDTR je p_mesginSDTR 656 cmp A,MSG_WDTR je p_mesginWDTR 657 jmp rej_mesgin 658 659p_mesginWDTR: 660 cmp ARG_1,2 jne rej_mesgin /* extended mesg length=2 */ 661 mvi ARG_1 call inb_next /* Width of bus */ 662 mvi INTSTAT,WDTR_MSG /* let driver know */ 663 test RETURN_1,0xff jz mesgin_done /* Do we need to send WDTR? */ 664 cmp RETURN_1,SEND_REJ je rej_mesgin /* 665 * Bus width was too large 666 * Reject it. 667 */ 668 669/* We didn't initiate the wide negotiation, so we must respond to the request */ 670 and RETURN_1,0x7f /* Clear the SEND_WDTR Flag */ 671 mvi DINDEX,MSG0 672 mvi MSG0 call mk_wdtr /* build WDTR message */ 673 or SINDEX,0x10,SIGSTATE /* turn on ATNO */ 674 call scsisig 675 jmp mesgin_done 676 677p_mesginSDTR: 678 cmp ARG_1,3 jne rej_mesgin /* extended mesg length=3 */ 679 mvi ARG_1 call inb_next /* xfer period */ 680 mvi A call inb_next /* REQ/ACK offset */ 681 mvi INTSTAT,SDTR_MSG /* call driver to convert */ 682 683 test RETURN_1,0xff jz mesgin_done /* Do we need to mk_sdtr/rej */ 684 cmp RETURN_1,SEND_REJ je rej_mesgin /* 685 * Requested SDTR too small 686 * Reject it. 687 */ 688 mvi DINDEX, MSG0 689 mvi MSG0 call mk_sdtr 690 or SINDEX,0x10,SIGSTATE /* turn on ATNO */ 691 call scsisig 692 jmp mesgin_done 693 694/* 695 * Is it a disconnect message? Set a flag in the SCB to remind us 696 * and await the bus going free. 697 */ 698mesgin_disconnect: 699 or SCB_CONTROL,DISCONNECTED 700 jmp mesgin_done 701 702/* 703 * Save data pointers message? Copy working values into the SCB, 704 * usually in preparation for a disconnect. 705 */ 706mesgin_sdptrs: 707 call sg_ram2scb 708 jmp mesgin_done 709 710/* 711 * Restore pointers message? Data pointers are recopied from the 712 * SCB anytime we enter a data phase for the first time, so all 713 * we need to do is clear the DPHASE flag and let the data phase 714 * code do the rest. 715 */ 716mesgin_rdptrs: 717 and FLAGS,0xfb /* 718 * !DPHASE we'll reload them 719 * the next time through 720 */ 721 jmp mesgin_done 722 723/* 724 * Identify message? For a reconnecting target, this tells us the lun 725 * that the reconnection is for - find the correct SCB and switch to it, 726 * clearing the "disconnected" bit so we don't "find" it by accident later. 727 */ 728mesgin_identify: 729 test A,0x78 jnz rej_mesgin /*!DiscPriv|!LUNTAR|!Reserved*/ 730 731 and A,0x07 /* lun in lower three bits */ 732 or SAVED_TCL,A,SELID 733 and SAVED_TCL,0xf7 734 and A,SELBUSB,SBLKCTL /* B Channel?? */ 735 or SAVED_TCL,A 736 call inb_last /* ACK */ 737 738/* 739 * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message. 740 * If we get one, we use the tag returned to switch to the proper 741 * SCB. Otherwise, we just use the findSCB method. 742 */ 743snoop_tag_loop: 744 test SSTAT1,BUSFREE jnz use_findSCB 745 test SSTAT1,REQINIT jz snoop_tag_loop 746 test SSTAT1,PHASEMIS jnz use_findSCB 747 mvi A call inb_first 748 cmp A,MSG_SIMPLE_TAG je get_tag 749use_findSCB: 750 mov ALLZEROS call findSCB /* Have to search */ 751setup_SCB: 752 and SCB_CONTROL,0xfb /* clear disconnect bit in SCB */ 753 or FLAGS,IDENTIFY_SEEN /* make note of IDENTIFY */ 754 jmp ITloop 755get_tag: 756 mvi ARG_1 call inb_next /* tag value */ 757/* 758 * See if the tag is in range. The tag is < SCBCOUNT if we add 759 * the complement of SCBCOUNT to the incomming tag and there is 760 * no carry. 761 */ 762 mov A,COMP_SCBCOUNT 763 add SINDEX,A,ARG_1 764 jc abort_tag 765 766/* 767 * Ensure that the SCB the tag points to is for an SCB transaction 768 * to the reconnecting target. 769 */ 770 mov SCBPTR,ARG_1 771 mov A,SAVED_TCL 772 cmp SCB_TCL,A jne abort_tag 773 test SCB_CONTROL,TAG_ENB jz abort_tag 774 call inb_last /* Ack Successful tag */ 775 jmp setup_SCB 776abort_tag: 777 or SINDEX,0x10,SIGSTATE /* turn on ATNO */ 778 call scsisig 779 mvi INTSTAT,ABORT_TAG /* let driver know */ 780 mvi 0xd call mk_mesg /* ABORT TAG message */ 781 jmp mesgin_done 782 783/* 784 * Message reject? Let the kernel driver handle this. If we have an 785 * outstanding WDTR or SDTR negotiation, assume that it's a response from 786 * the target selecting 8bit or asynchronous transfer, otherwise just ignore 787 * it since we have no clue what it pertains to. 788 */ 789mesgin_reject: 790 mvi INTSTAT, REJECT_MSG 791 jmp mesgin_done 792 793/* 794 * [ ADD MORE MESSAGE HANDLING HERE ] 795 */ 796 797/* 798 * Bus free phase. It might be useful to interrupt the device 799 * driver if we aren't expecting this. For now, make sure that 800 * ATN isn't being asserted and look for a new command. 801 */ 802p_busfree: 803 mvi CLRSINT1,CLRATNO 804 805/* 806 * if this is an immediate command, perform a psuedo command complete to 807 * notify the driver. 808 */ 809 test SCB_CMDLEN,0xff jz status_ok 810 jmp start 811 812/* 813 * Instead of a generic bcopy routine that requires an argument, we unroll 814 * the cases that are actually used, and call them explicitly. This 815 * not only reduces the overhead of doing a bcopy, but ends up saving space 816 * in the program since you don't have to put the argument into the accumulator 817 * before the call. Both functions expect DINDEX to contain the destination 818 * address and SINDEX to contain the source address. 819 */ 820bcopy_7: 821 mov DINDIR,SINDIR 822 mov DINDIR,SINDIR 823bcopy_5: 824 mov DINDIR,SINDIR 825bcopy_4: 826 mov DINDIR,SINDIR 827bcopy_3: 828 mov DINDIR,SINDIR 829 mov DINDIR,SINDIR 830 mov DINDIR,SINDIR ret 831 832bcopy_7_dfdat: 833 mov DINDIR,DFDAT 834 mov DINDIR,DFDAT 835bcopy_5_dfdat: 836 mov DINDIR,DFDAT 837bcopy_4_dfdat: 838 mov DINDIR,DFDAT 839bcopy_3_dfdat: 840 mov DINDIR,DFDAT 841 mov DINDIR,DFDAT 842 mov DINDIR,DFDAT ret 843 844/* 845 * Locking the driver out, build a one-byte message passed in SINDEX 846 * if there is no active message already. SINDEX is returned intact. 847 */ 848mk_mesg: 849 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 850 test MSG_LEN,0xff jz mk_mesg1 /* Should always succeed */ 851 852 /* 853 * Hmmm. For some reason the mesg buffer is in use. 854 * Tell the driver. It should look at SINDEX to find 855 * out what we wanted to use the buffer for and resolve 856 * the conflict. 857 */ 858 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 859 mvi INTSTAT,MSG_BUFFER_BUSY ret 860 861mk_mesg1: 862 mvi MSG_LEN,1 /* length = 1 */ 863 mov MSG0,SINDEX /* 1-byte message */ 864 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 865 866/* 867 * Functions to read data in Automatic PIO mode. 868 * 869 * According to Adaptec's documentation, an ACK is not sent on input from 870 * the target until SCSIDATL is read from. So we wait until SCSIDATL is 871 * latched (the usual way), then read the data byte directly off the bus 872 * using SCSIBUSL. When we have pulled the ATN line, or we just want to 873 * acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI 874 * spec guarantees that the target will hold the data byte on the bus until 875 * we send our ACK. 876 * 877 * The assumption here is that these are called in a particular sequence, 878 * and that REQ is already set when inb_first is called. inb_{first,next} 879 * use the same calling convention as inb. 880 */ 881 882inb_next: 883 call inb_last 884inb_next_wait: 885 test SSTAT1,PHASEMIS jnz mesgin_phasemis 886 test SSTAT0,SPIORDY jz inb_next_wait /* wait for next byte */ 887inb_first: 888 mov DINDEX,SINDEX 889 mov DINDIR,SCSIBUSL ret /*read byte directly from bus*/ 890inb_last: 891 clr STCNT2 892 clr STCNT1 893 mvi STCNT0,0x01 894 mov NONE,SCSIDATL /*dummy read from latch to ACK*/ 895inb_last_wait: 896 test SSTAT0,SDONE jz inb_last_wait /* Wait for completion */ 897 ret 898 899 900 901mesgin_phasemis: 902/* 903 * We expected to receive another byte, but the target changed phase 904 */ 905 mvi INTSTAT, MSGIN_PHASEMIS 906 jmp ITloop 907 908/* 909 * DMA data transfer. HADDR and HCNT must be loaded first, and 910 * SINDEX should contain the value to load DFCNTRL with - 0x3d for 911 * host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared 912 * during initialization. 913 */ 914dma: 915 mov DFCNTRL,SINDEX 916dma1: 917 test SSTAT0,DMADONE jnz dma3 918 test SSTAT1,PHASEMIS jz dma1 /* ie. underrun */ 919 920/* 921 * We will be "done" DMAing when the transfer count goes to zero, or 922 * the target changes the phase (in light of this, it makes sense that 923 * the DMA circuitry doesn't ACK when PHASEMIS is active). If we are 924 * doing a SCSI->Host transfer, the data FIFO should be flushed auto- 925 * magically on STCNT=0 or a phase change, so just wait for FIFO empty 926 * status. 927 */ 928dma3: 929 test SINDEX,DIRECTION jnz dma5 930dma4: 931 test DFSTATUS,FIFOEMP jz dma4 932 933/* 934 * Now shut the DMA enables off and make sure that the DMA enables are 935 * actually off first lest we get an ILLSADDR. 936 */ 937dma5: 938 /* disable DMA, but maintain WIDEODD */ 939 and A, WIDEODD, SINDEX 940 mov DFCNTRL, A 941dma6: 942 test DFCNTRL,0x38 jnz dma6 /* SCSIENACK|SDMAENACK|HDMAENACK */ 943 944 ret 945 946dma_finish: 947 test DFSTATUS,HDONE jz dma_finish 948 949 clr DFCNTRL /* disable DMA */ 950dma_finish2: 951 test DFCNTRL,HDMAENACK jnz dma_finish2 952 ret 953 954/* 955 * Common SCSI initialization for selection and reselection. Expects 956 * the target SCSI ID to be in the upper four bits of SINDEX, and A's 957 * contents are stomped on return. 958 */ 959initialize_scsiid: 960 and SINDEX,0xf0 /* Get target ID */ 961 and A,0x0f,SCSIID 962 or SINDEX,A 963 mov SCSIID,SINDEX ret 964 965/* 966 * Assert that if we've been reselected, then we've seen an IDENTIFY 967 * message. 968 */ 969assert: 970 test FLAGS,RESELECTED jz return /* reselected? */ 971 test FLAGS,IDENTIFY_SEEN jnz return /* seen IDENTIFY? */ 972 973 mvi INTSTAT,NO_IDENT ret /* no - cause a kernel panic */ 974 975/* 976 * Locate the SCB matching the target ID/channel/lun in SAVED_TCL and switch 977 * the SCB to it. Have the kernel print a warning message if it can't be 978 * found, and generate an ABORT message to the target. SINDEX should be 979 * cleared on call. 980 */ 981findSCB: 982 mov A,SAVED_TCL 983 mov SCBPTR,SINDEX /* switch to new SCB */ 984 cmp SCB_TCL,A jne findSCB1 /* target ID/channel/lun match? */ 985 test SCB_CONTROL,DISCONNECTED jz findSCB1 /*should be disconnected*/ 986 ret 987 988findSCB1: 989 inc SINDEX 990 mov A,SCBCOUNT 991 cmp SINDEX,A jne findSCB 992 993 mvi INTSTAT,NO_MATCH /* not found - signal kernel */ 994 mvi MSG_ABORT call mk_mesg /* ABORT message */ 995 996 or SINDEX,0x10,SIGSTATE /* assert ATNO */ 997 call scsisig 998 ret 999/* 1000 * Make a working copy of the scatter-gather parameters from the SCB. 1001 */ 1002sg_scb2ram: 1003 mvi DINDEX,HADDR 1004 mvi SCB_DATAPTR call bcopy_7 1005 1006 mvi DINDEX,STCNT 1007 mvi SCB_DATACNT call bcopy_3 1008 1009 mov SG_COUNT,SCB_SGCOUNT 1010 1011 mvi DINDEX,SG_NEXT 1012 mvi SCB_SGPTR call bcopy_4 1013 ret 1014 1015/* 1016 * Copying RAM values back to SCB, for Save Data Pointers message, but 1017 * only if we've actually been into a data phase to change them. This 1018 * protects against bogus data in scratch ram and the residual counts 1019 * since they are only initialized when we go into data_in or data_out. 1020 */ 1021sg_ram2scb: 1022 test FLAGS, DPHASE jz return 1023 mov SCB_SGCOUNT,SG_COUNT 1024 1025 mvi DINDEX,SCB_SGPTR 1026 mvi SG_NEXT call bcopy_4 1027 1028 mvi DINDEX,SCB_DATAPTR 1029 mvi SHADDR call bcopy_4 1030 1031/* 1032 * Use the residual number since STCNT is corrupted by any message transfer 1033 */ 1034 mvi SCB_RESID_DCNT call bcopy_3 1035 ret 1036 1037/* 1038 * Add the array base TARG_SCRATCH to the target offset (the target address 1039 * is in SCSIID), and return the result in SINDEX. The accumulator 1040 * contains the 3->8 decoding of the target ID on return. 1041 */ 1042ndx_dtr: 1043 shr A,SCSIID,4 1044 test SBLKCTL,SELBUSB jz ndx_dtr_2 1045 or A,0x08 /* Channel B entries add 8 */ 1046ndx_dtr_2: 1047 add SINDEX,TARG_SCRATCH,A 1048 1049 mov FUNCTION1,SCSIID /* 3-bit target address decode */ 1050 mov A,FUNCTION1 ret 1051 1052/* 1053 * If we need to negotiate transfer parameters, build the WDTR or SDTR message 1054 * starting at the address passed in SINDEX. DINDEX is modified on return. 1055 * The SCSI-II spec requires that Wide negotiation occur first and you can 1056 * only negotiat one or the other at a time otherwise in the event of a message 1057 * reject, you wouldn't be able to tell which message was the culpret. 1058 */ 1059mk_dtr: 1060 test SCB_CONTROL,0x90 jz return /* NEEDWDTR|NEEDSDTR */ 1061 test SCB_CONTROL,NEEDWDTR jnz mk_wdtr_16bit 1062 or FLAGS, MAXOFFSET /* Force an offset of 15 or 8 if WIDE */ 1063 1064mk_sdtr: 1065 mvi DINDIR,1 /* extended message */ 1066 mvi DINDIR,3 /* extended message length = 3 */ 1067 mvi DINDIR,1 /* SDTR code */ 1068 call sdtr_to_rate 1069 mov DINDIR,RETURN_1 /* REQ/ACK transfer period */ 1070 test FLAGS, MAXOFFSET jnz mk_sdtr_max_offset 1071 and DINDIR,0x0f,SINDIR /* Sync Offset */ 1072 1073mk_sdtr_done: 1074 add MSG_LEN,COMP_MSG0,DINDEX ret /* update message length */ 1075 1076mk_sdtr_max_offset: 1077/* 1078 * We're initiating sync negotiation, so request the max offset we can (15 or 8) 1079 */ 1080 xor FLAGS, MAXOFFSET 1081 1082 /* Talking to a WIDE device? */ 1083 test SCSIRATE, WIDEXFER jnz wmax_offset 1084 mvi DINDIR, MAX_OFFSET_8BIT 1085 jmp mk_sdtr_done 1086 1087wmax_offset: 1088 mvi DINDIR, MAX_OFFSET_16BIT 1089 jmp mk_sdtr_done 1090 1091mk_wdtr_16bit: 1092 mvi ARG_1,BUS_16_BIT 1093mk_wdtr: 1094 mvi DINDIR,1 /* extended message */ 1095 mvi DINDIR,2 /* extended message length = 2 */ 1096 mvi DINDIR,3 /* WDTR code */ 1097 mov DINDIR,ARG_1 /* bus width */ 1098 1099 add MSG_LEN,COMP_MSG0,DINDEX ret /* update message length */ 1100 1101/* 1102 * Set SCSI bus control signal state. This also saves the last-written 1103 * value into a location where the higher-level driver can read it - if 1104 * it has to send an ABORT or RESET message, then it needs to know this 1105 * so it can assert ATN without upsetting SCSISIGO. The new value is 1106 * expected in SINDEX. Change the actual state last to avoid contention 1107 * from the driver. 1108 */ 1109scsisig: 1110 mov SIGSTATE,SINDEX 1111 mov SCSISIGO,SINDEX ret 1112 1113sdtr_to_rate: 1114 call ndx_dtr /* index scratch space for target */ 1115 shr A,SINDIR,0x4 1116 dec SINDEX /* Preserve SINDEX */ 1117 and A,0x7 1118 clr RETURN_1 1119sdtr_to_rate_loop: 1120 test A,0x0f jz sdtr_to_rate_done 1121 add RETURN_1,0x19 1122 dec A 1123 jmp sdtr_to_rate_loop 1124sdtr_to_rate_done: 1125 shr RETURN_1,0x2 1126 add RETURN_1,0x19 1127 test SXFRCTL0,ULTRAEN jz return 1128 shr RETURN_1,0x1 1129return: 1130 ret 1131