aic7xxx.seq revision 15998
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 *FreeBSD, Twin, Wide, 2 command per target support, tagged queuing, 9 *SCB paging and other optimizations: 10 *Copyright (c) 1994, 1995, 1996 Justin Gibbs. All rights reserved. 11 * 12 *Redistribution and use in source and binary forms, with or without 13 *modification, are permitted provided that the following conditions 14 *are met: 15 *1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions, and the following disclaimer. 17 *2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 *3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of Calgary 23 * Department of Computer Science and its contributors. 24 *4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 *THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 29 *ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 *IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 *ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 32 *FOR ANY DIRECT, INDIRECT, INCIDENTAL, 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, STRICT 36 *LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 *OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 *SUCH DAMAGE. 39 * 40 *-M************************************************************************/ 41 42VERSION AIC7XXX_SEQ_VER "$Id: aic7xxx.seq,v 1.37 1996/05/27 23:16:55 gibbs Exp $" 43 44#if defined(__NetBSD__) 45#include "../../../../dev/ic/aic7xxxreg.h" 46#elif defined(__FreeBSD__) 47#include "../../dev/aic7xxx/aic7xxx_reg.h" 48#endif 49 50/* 51 * We can't just use ACCUM in the sequencer code because it 52 * must be treated specially by the assembler, and it currently 53 * looks for the symbol 'A'. This is the only register defined in 54 * the assembler's symbol space. 55 */ 56A = ACCUM 57 58/* After starting the selection hardware, we check for reconnecting targets 59 * as well as for our selection to complete just in case the reselection wins 60 * bus arbitration. The problem with this is that we must keep track of the 61 * SCB that we've already pulled from the QINFIFO and started the selection 62 * on just in case the reselection wins so that we can retry the selection at 63 * a later time. This problem cannot be resolved by holding a single entry 64 * in scratch ram since a reconnecting target can request sense and this will 65 * create yet another SCB waiting for selection. The solution used here is to 66 * use byte 27 of the SCB as a psuedo-next pointer and to thread a list 67 * of SCBs that are awaiting selection. Since 0-0xfe are valid SCB offsets, 68 * SCB_LIST_NULL is 0xff which is out of range. The kernel driver must 69 * add an entry to this list everytime a request sense occurs. The sequencer 70 * will automatically consume the entries. 71 */ 72 73/* 74 * We assume that the kernel driver may reset us at any time, even in the 75 * middle of a DMA, so clear DFCNTRL too. 76 */ 77reset: 78 clr DFCNTRL 79 clr SCSISIGO /* De-assert BSY */ 80/* 81 * We jump to start after every bus free. 82 */ 83start: 84 and FLAGS,0x0f /* clear target specific flags */ 85 mvi SCSISEQ,ENRSELI /* Always allow reselection */ 86poll_for_work: 87 /* 88 * Are we a twin channel device? 89 * For fairness, we check the other bus first, 90 * since we just finished a transaction on the 91 * current channel. 92 */ 93 test FLAGS,TWIN_BUS jz start2 94 xor SBLKCTL,SELBUSB /* Toggle to the other bus */ 95 test SSTAT0,SELDI jnz reselect 96 xor SBLKCTL,SELBUSB /* Toggle to the original bus */ 97start2: 98 test SSTAT0,SELDI jnz reselect 99 cmp WAITING_SCBH,SCB_LIST_NULL jne start_waiting 100 mov A, QCNTMASK 101 test QINCNT,A jz poll_for_work 102 103/* 104 * We have at least one queued SCB now and we don't have any 105 * SCBs in the list of SCBs awaiting selection. Set the SCB 106 * pointer from the FIFO so we see the right bank of SCB 107 * registers. 108 */ 109 mov SCBPTR,QINFIFO 110 111/* 112 * See if there is not already an active SCB for this target. This code 113 * locks out on a per target basis instead of target/lun. Although this 114 * is not ideal for devices that have multiple luns active at the same 115 * time, it is faster than looping through all SCB's looking for active 116 * commands. It may be benificial to make findscb a more general procedure 117 * to see if the added cost of the search is negligible. This code also 118 * assumes that the kernel driver will clear the active flags on board 119 * initialization, board reset, and a target SELTO. Tagged commands 120 * don't set the active bits since you can queue more than one command 121 * at a time. We do, however, look to see if there are any non-tagged 122 * I/Os in progress, and requeue the command if there are. Tagged and 123 * non-tagged commands cannot be mixed to a single target. 124 */ 125 126test_busy: 127 mov FUNCTION1,SCB_TCL 128 mov A,FUNCTION1 129 test SCB_TCL,0x88 jz test_a /* Id < 8 && A channel */ 130 131 test ACTIVE_B,A jnz requeue 132 test SCB_CONTROL,TAG_ENB jnz start_scb 133 /* Mark the current target as busy */ 134 or ACTIVE_B,A 135 jmp start_scb 136 137/* Place the currently active SCB back on the queue for later processing */ 138requeue: 139 mov QINFIFO, SCBPTR 140 jmp poll_for_work 141 142/* 143 * Pull the first entry off of the waiting for selection list 144 * We don't have to "test_busy" because only transactions that 145 * have passed that test can be in the waiting_scb list. 146 */ 147start_waiting: 148 mov SCBPTR,WAITING_SCBH 149 jmp start_scb2 150 151test_a: 152 test ACTIVE_A,A jnz requeue 153 test SCB_CONTROL,TAG_ENB jnz start_scb 154 /* Mark the current target as busy */ 155 or ACTIVE_A,A 156 157start_scb: 158 mov SCB_NEXT,WAITING_SCBH 159 mov WAITING_SCBH, SCBPTR 160start_scb2: 161 and SINDEX,0xf7,SBLKCTL /* Clear the channel select bit */ 162 and A,0x08,SCB_TCL /* Get new channel bit */ 163 or SINDEX,A 164 mov SBLKCTL,SINDEX /* select channel */ 165 mov SCB_TCL call initialize_scsiid 166 167/* 168 * Enable selection phase as an initiator, and do automatic ATN 169 * after the selection. We do this now so that we can overlap the 170 * rest of our work to set up this target with the arbitration and 171 * selection bus phases. 172 */ 173start_selection: 174 mvi SCSISEQ,0x58 /* ENSELO|ENAUTOATNO|ENRSELI */ 175 176/* 177 * As soon as we get a successful selection, the target should go 178 * into the message out phase since we have ATN asserted. Prepare 179 * the message to send. 180 * 181 * Messages are stored in scratch RAM starting with a length byte 182 * followed by the message itself. 183 */ 184 test SCB_CMDLEN,0xff jnz mk_identify /* 0 Length Command? */ 185 186/* 187 * The kernel has sent us an SCB with no command attached. This implies 188 * that the kernel wants to send a message of some sort to this target, 189 * so we interrupt the driver, allow it to fill the message buffer, and 190 * then go back into the arbitration loop 191 */ 192 mvi INTSTAT,AWAITING_MSG 193 jmp wait_for_selection 194 195mk_identify: 196 and A,DISCENB,SCB_CONTROL /* mask off disconnect privledge */ 197 198 and MSG0,0x7,SCB_TCL /* lun */ 199 or MSG0,A /* or in disconnect privledge */ 200 or MSG0,MSG_IDENTIFY 201 mvi MSG_LEN, 1 202 203 test SCB_CONTROL,0xb0 jz !message /* WDTR, SDTR or TAG?? */ 204/* 205 * Send a tag message if TAG_ENB is set in the SCB control block. 206 * Use SCB_TAG (the position in the kernel's SCB array) as the tag value. 207 */ 208 209mk_tag: 210 mvi DINDEX, MSG1 211 test SCB_CONTROL,TAG_ENB jz mk_tag_done 212 and DINDIR,0x23,SCB_CONTROL 213 mov DINDIR,SCB_TAG 214 215 add MSG_LEN,COMP_MSG0,DINDEX /* update message length */ 216 217mk_tag_done: 218 219 test SCB_CONTROL,0x90 jz !message /* NEEDWDTR|NEEDSDTR */ 220 mov DINDEX call mk_dtr /* build DTR message if needed */ 221 222!message: 223wait_for_selection: 224 test SSTAT0,SELDO jnz select 225 test SSTAT0,SELDI jz wait_for_selection 226 227/* 228 * Reselection has been initiated by a target. Make a note that we've been 229 * reselected, but haven't seen an IDENTIFY message from the target 230 * yet. 231 */ 232reselect: 233 clr MSG_LEN /* Don't have anything in the mesg buffer */ 234 mov SELID call initialize_scsiid 235 or FLAGS,RESELECTED 236 jmp select2 237 238/* 239 * After the selection, remove this SCB from the "waiting for selection" 240 * list. This is achieved by simply moving our "next" pointer into 241 * WAITING_SCBH. Our next pointer will be set to null the next time this 242 * SCB is used, so don't bother with it now. 243 */ 244select: 245 mov WAITING_SCBH,SCB_NEXT 246 or FLAGS,SELECTED 247select2: 248/* 249 * Set CLRCHN here before the target has entered a data transfer mode - 250 * with synchronous SCSI, if you do it later, you blow away some 251 * data in the SCSI FIFO that the target has already sent to you. 252 */ 253 or SXFRCTL0,CLRCHN 254/* 255 * Initialize SCSIRATE with the appropriate value for this target. 256 */ 257 call ndx_dtr 258 mov SCSIRATE,SINDIR 259 260/* 261 * Initialize Ultra mode setting. 262 */ 263 mov FUNCTION1,SCSIID 264 mov A,FUNCTION1 265 and SINDEX,0xdf,SXFRCTL0 /* default to Ultra disabled */ 266 test SCSIID, 0x80 jnz ultra_b /* Target ID > 7 */ 267 test SBLKCTL, SELBUSB jnz ultra_b /* Second channel device */ 268 test ULTRA_ENB,A jz set_sxfrctl0 269 or SINDEX, ULTRAEN jmp set_sxfrctl0 270ultra_b: 271 test ULTRA_ENB_B,A jz set_sxfrctl0 272 or SINDEX, ULTRAEN 273 274set_sxfrctl0: 275 mov SXFRCTL0,SINDEX 276 277 mvi SCSISEQ,ENAUTOATNP /* 278 * ATN on parity errors 279 * for "in" phases 280 */ 281 mvi CLRSINT1,CLRBUSFREE 282 mvi CLRSINT0,0x60 /* CLRSELDI|CLRSELDO */ 283/* 284 * Main loop for information transfer phases. If BSY is false, then 285 * we have a bus free condition, expected or not. Otherwise, wait 286 * for the target to assert REQ before checking MSG, C/D and I/O 287 * for the bus phase. 288 * 289 */ 290ITloop: 291 test SSTAT1,BUSFREE jnz p_busfree 292 test SSTAT1,REQINIT jz ITloop 293 294 and A,PHASE_MASK,SCSISIGI 295 mov LASTPHASE,A 296 mov SCSISIGO,A 297 298 cmp ALLZEROS,A je p_dataout 299 cmp A,P_DATAIN je p_datain 300 cmp A,P_COMMAND je p_command 301 cmp A,P_MESGOUT je p_mesgout 302 cmp A,P_STATUS je p_status 303 cmp A,P_MESGIN je p_mesgin 304 305 mvi INTSTAT,BAD_PHASE /* unknown phase - signal driver */ 306 jmp ITloop /* Try reading the bus again. */ 307 308p_dataout: 309 mvi DMAPARAMS,0x7d /* 310 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 311 * DIRECTION|FIFORESET 312 */ 313 jmp data_phase_init 314 315/* 316 * If we re-enter the data phase after going through another phase, the 317 * STCNT may have been cleared, so restore it from the residual field. 318 */ 319data_phase_reinit: 320 mov STCNT0,SCB_RESID_DCNT0 321 mov STCNT1,SCB_RESID_DCNT1 322 mov STCNT2,SCB_RESID_DCNT2 323 jmp data_phase_loop 324 325p_datain: 326 mvi DMAPARAMS,0x79 /* 327 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 328 * !DIRECTION|FIFORESET 329 */ 330data_phase_init: 331 call assert 332 333 test FLAGS, DPHASE jnz data_phase_reinit 334 call sg_scb2ram 335 or FLAGS, DPHASE /* We have seen a data phase */ 336 337data_phase_loop: 338/* If we are the last SG block, don't set wideodd. */ 339 cmp SG_COUNT,0x01 jne data_phase_wideodd 340 and DMAPARAMS, 0xbf /* Turn off WIDEODD */ 341data_phase_wideodd: 342 mov DMAPARAMS call dma 343 344/* Exit if we had an underrun */ 345 test SSTAT0,SDONE jz data_phase_finish /* underrun STCNT != 0 */ 346 347/* 348 * Advance the scatter-gather pointers if needed 349 */ 350sg_advance: 351 dec SG_COUNT /* one less segment to go */ 352 353 test SG_COUNT, 0xff jz data_phase_finish /* Are we done? */ 354 355 clr A /* add sizeof(struct scatter) */ 356 add SG_NEXT0,SG_SIZEOF,SG_NEXT0 357 adc SG_NEXT1,A,SG_NEXT1 358 359/* 360 * Load a struct scatter and set up the data address and length. 361 * If the working value of the SG count is nonzero, then 362 * we need to load a new set of values. 363 * 364 * This, like all DMA's, assumes little-endian host data storage. 365 */ 366sg_load: 367 clr HCNT2 368 clr HCNT1 369 mvi HCNT0,SG_SIZEOF 370 371 mov HADDR0,SG_NEXT0 372 mov HADDR1,SG_NEXT1 373 mov HADDR2,SG_NEXT2 374 mov HADDR3,SG_NEXT3 375 376 or DFCNTRL,0xd /* HDMAEN|DIRECTION|FIFORESET */ 377 378/* 379 * Wait for DMA from host memory to data FIFO to complete, then disable 380 * DMA and wait for it to acknowledge that it's off. 381 */ 382dma_finish: 383 test DFSTATUS,HDONE jz dma_finish 384 /* Turn off DMA preserving WIDEODD */ 385 and DFCNTRL,WIDEODD 386dma_finish2: 387 test DFCNTRL,HDMAENACK jnz dma_finish2 388 389/* 390 * Copy data from FIFO into SCB data pointer and data count. This assumes 391 * that the struct scatterlist has this structure (this and sizeof(struct 392 * scatterlist) == 12 are asserted in aic7xxx.c for the Linux driver): 393 * 394 * struct scatterlist { 395 * char *address; four bytes, little-endian order 396 * ... four bytes, ignored 397 * unsigned short length; two bytes, little-endian order 398 * } 399 * 400 * 401 * In FreeBSD, the scatter list entry is only 8 bytes. 402 * 403 * struct ahc_dma_seg { 404 * physaddr addr; four bytes, little-endian order 405 * long len; four bytes, little endian order 406 * }; 407 */ 408 409 mov HADDR0,DFDAT 410 mov HADDR1,DFDAT 411 mov HADDR2,DFDAT 412 mov HADDR3,DFDAT 413/* 414 * For Linux, we must throw away four bytes since there is a 32bit gap 415 * in the middle of a struct scatterlist. 416 */ 417#ifdef __linux__ 418 mov NONE,DFDAT 419 mov NONE,DFDAT 420 mov NONE,DFDAT 421 mov NONE,DFDAT 422#endif 423 mov HCNT0,DFDAT 424 mov HCNT1,DFDAT 425 mov HCNT2,DFDAT 426 427/* Load STCNT as well. It is a mirror of HCNT */ 428 mov STCNT0,HCNT0 429 mov STCNT1,HCNT1 430 mov STCNT2,HCNT2 431 test SSTAT1,PHASEMIS jz data_phase_loop 432 433data_phase_finish: 434/* 435 * After a DMA finishes, save the SG and STCNT residuals back into the SCB 436 * We use STCNT instead of HCNT, since it's a reflection of how many bytes 437 * were transferred on the SCSI (as opposed to the host) bus. 438 */ 439 mov SCB_RESID_DCNT0,STCNT0 440 mov SCB_RESID_DCNT1,STCNT1 441 mov SCB_RESID_DCNT2,STCNT2 442 mov SCB_RESID_SGCNT, SG_COUNT 443 jmp ITloop 444 445/* 446 * Command phase. Set up the DMA registers and let 'er rip. 447 */ 448p_command: 449 call assert 450 451/* 452 * Load HADDR and HCNT. 453 */ 454 mov HADDR0, SCB_CMDPTR0 455 mov HADDR1, SCB_CMDPTR1 456 mov HADDR2, SCB_CMDPTR2 457 mov HADDR3, SCB_CMDPTR3 458 mov HCNT0, SCB_CMDLEN 459 clr HCNT1 460 clr HCNT2 461 462 mov STCNT0, HCNT0 463 mov STCNT1, HCNT1 464 mov STCNT2, HCNT2 465 466 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 467 # DIRECTION|FIFORESET 468 jmp ITloop 469 470/* 471 * Status phase. Wait for the data byte to appear, then read it 472 * and store it into the SCB. 473 */ 474p_status: 475 mvi SCB_TARGET_STATUS call inb_first 476 jmp mesgin_done 477 478/* 479 * Message out phase. If there is not an active message, but the target 480 * took us into this phase anyway, build a no-op message and send it. 481 */ 482p_mesgout: 483 test MSG_LEN, 0xff jnz p_mesgout_start 484 mvi MSG_NOP call mk_mesg /* build NOP message */ 485 486p_mesgout_start: 487/* 488 * Set up automatic PIO transfer from MSG0. Bit 3 in 489 * SXFRCTL0 (SPIOEN) is already on. 490 */ 491 mvi SINDEX,MSG0 492 mov DINDEX,MSG_LEN 493 494/* 495 * When target asks for a byte, drop ATN if it's the last one in 496 * the message. Otherwise, keep going until the message is exhausted. 497 * 498 * Keep an eye out for a phase change, in case the target issues 499 * a MESSAGE REJECT. 500 */ 501p_mesgout_loop: 502 test SSTAT0,SPIORDY jz p_mesgout_loop 503 test SSTAT1,PHASEMIS jnz p_mesgout_phasemis 504 cmp DINDEX,1 jne p_mesgout_outb /* last byte? */ 505 mvi CLRSINT1,CLRATNO /* drop ATN */ 506p_mesgout_outb: 507 dec DINDEX 508 or CLRSINT0, CLRSPIORDY 509 mov SCSIDATL,SINDIR 510 511p_mesgout4: 512 test DINDEX,0xff jnz p_mesgout_loop 513 514/* 515 * If the next bus phase after ATN drops is a message out, it means 516 * that the target is requesting that the last message(s) be resent. 517 */ 518p_mesgout_snoop: 519 test SSTAT1,BUSFREE jnz p_mesgout_done 520 test SSTAT1,REQINIT jz p_mesgout_snoop 521 522 test SSTAT1,PHASEMIS jnz p_mesgout_done 523 524 or SCSISIGO,ATNO /* turn on ATNO */ 525 526 jmp ITloop 527 528p_mesgout_phasemis: 529 mvi CLRSINT1,CLRATNO /* Be sure to turn ATNO off */ 530p_mesgout_done: 531 clr MSG_LEN /* no active msg */ 532 jmp ITloop 533 534/* 535 * Message in phase. Bytes are read using Automatic PIO mode. 536 */ 537p_mesgin: 538 mvi A call inb_first /* read the 1st message byte */ 539 mov REJBYTE,A /* save it for the driver */ 540 541 test A,MSG_IDENTIFY jnz mesgin_identify 542 cmp A,MSG_DISCONNECT je mesgin_disconnect 543 cmp A,MSG_SDPTRS je mesgin_sdptrs 544 cmp ALLZEROS,A je mesgin_complete 545 cmp A,MSG_RDPTRS je mesgin_rdptrs 546 cmp A,MSG_EXTENDED je mesgin_extended 547 cmp A,MSG_REJECT je mesgin_reject 548 549rej_mesgin: 550/* 551 * We have no idea what this message in is, and there's no way 552 * to pass it up to the kernel, so we issue a message reject and 553 * hope for the best. Since we're now using manual PIO mode to 554 * read in the message, there should no longer be a race condition 555 * present when we assert ATN. In any case, rejection should be a 556 * rare occurrence - signal the driver when it happens. 557 */ 558 or SCSISIGO,ATNO /* turn on ATNO */ 559 mvi INTSTAT,SEND_REJECT /* let driver know */ 560 561 mvi MSG_REJECT call mk_mesg 562 563mesgin_done: 564 call inb_last /*ack & turn auto PIO back on*/ 565 jmp ITloop 566 567 568mesgin_complete: 569/* 570 * We got a "command complete" message, so put the SCB_TAG into QUEUEOUT, 571 * and trigger a completion interrupt. Check status for non zero return 572 * and interrupt driver if needed. This allows the driver to interpret 573 * errors only when they occur instead of always uploading the scb. If 574 * the status is SCSI_CHECK, the driver will download a new scb requesting 575 * sense to replace the old one, modify the "waiting for selection" SCB list 576 * and set RETURN_1 to SEND_SENSE. If RETURN_1 is set to SEND_SENSE the 577 * sequencer imediately jumps to main loop where it will run down the waiting 578 * SCB list and process the sense request. If the kernel driver does not 579 * wish to request sense, it need only clear RETURN_1, and the command is 580 * allowed to complete. We don't bother to post to the QOUTFIFO in the 581 * error case since it would require extra work in the kernel driver to 582 * ensure that the entry was removed before the command complete code tried 583 * processing it. 584 * 585 * First check for residuals 586 */ 587 test SCB_RESID_SGCNT,0xff jz check_status 588/* 589 * If we have a residual count, interrupt and tell the host. Other 590 * alternatives are to pause the sequencer on all command completes (yuck), 591 * dma the resid directly to the host (slick, we may have space to do it now) 592 * or have the sequencer pause itself when it encounters a non-zero resid 593 * (unecessary pause just to flag the command -yuck-, but takes one instruction 594 * and since it shouldn't happen that often is good enough for our purposes). 595 */ 596resid: 597 mvi INTSTAT,RESIDUAL 598 599check_status: 600 test SCB_TARGET_STATUS,0xff jz status_ok /* Good Status? */ 601 mvi INTSTAT,BAD_STATUS /* let driver know */ 602 cmp RETURN_1, SEND_SENSE jne status_ok 603 jmp mesgin_done 604 605status_ok: 606/* First, mark this target as free. */ 607 test SCB_CONTROL,TAG_ENB jnz test_immediate /* 608 * Tagged commands 609 * don't busy the 610 * target. 611 */ 612 mov FUNCTION1,SCB_TCL 613 mov A,FUNCTION1 614 test SCB_TCL,0x88 jz clear_a 615 xor ACTIVE_B,A 616 jmp test_immediate 617 618clear_a: 619 xor ACTIVE_A,A 620 621test_immediate: 622 test SCB_CMDLEN,0xff jnz complete /* Immediate message complete */ 623/* 624 * Pause the sequencer until the driver gets around to handling the command 625 * complete. This is so that any action that might require carefull timing 626 * with the completion of this command can occur. 627 */ 628 mvi INTSTAT,IMMEDDONE 629 jmp start 630complete: 631 mov QOUTFIFO,SCB_TAG 632 mvi INTSTAT,CMDCMPLT 633 jmp mesgin_done 634 635 636/* 637 * Is it an extended message? We only support the synchronous and wide data 638 * transfer request messages, which will probably be in response to 639 * WDTR or SDTR message outs from us. If it's not SDTR or WDTR, reject it - 640 * apparently this can be done after any message in byte, according 641 * to the SCSI-2 spec. 642 */ 643mesgin_extended: 644 mvi ARG_1 call inb_next /* extended message length */ 645 mvi REJBYTE_EXT call inb_next /* extended message code */ 646 647 cmp REJBYTE_EXT,MSG_SDTR je p_mesginSDTR 648 cmp REJBYTE_EXT,MSG_WDTR je p_mesginWDTR 649 jmp rej_mesgin 650 651p_mesginWDTR: 652 cmp ARG_1,2 jne rej_mesgin /* extended mesg length=2 */ 653 mvi ARG_1 call inb_next /* Width of bus */ 654 mvi INTSTAT,WDTR_MSG /* let driver know */ 655 test RETURN_1,0xff jz mesgin_done /* Do we need to send WDTR? */ 656 cmp RETURN_1,SEND_REJ je rej_mesgin /* 657 * Bus width was too large 658 * Reject it. 659 */ 660 661/* We didn't initiate the wide negotiation, so we must respond to the request */ 662 and RETURN_1,0x7f /* Clear the SEND_WDTR Flag */ 663 mvi DINDEX,MSG0 664 mvi MSG0 call mk_wdtr /* build WDTR message */ 665 or SCSISIGO,ATNO /* turn on ATNO */ 666 jmp mesgin_done 667 668p_mesginSDTR: 669 cmp ARG_1,3 jne rej_mesgin /* extended mesg length=3 */ 670 mvi ARG_1 call inb_next /* xfer period */ 671 mvi A call inb_next /* REQ/ACK offset */ 672 mvi INTSTAT,SDTR_MSG /* call driver to convert */ 673 674 test RETURN_1,0xff jz mesgin_done /* Do we need to mk_sdtr/rej */ 675 cmp RETURN_1,SEND_REJ je rej_mesgin /* 676 * Requested SDTR too small 677 * Reject it. 678 */ 679 clr ARG_1 /* Use the scratch ram rate */ 680 mvi DINDEX, MSG0 681 mvi MSG0 call mk_sdtr 682 or SCSISIGO,ATNO /* turn on ATNO */ 683 jmp mesgin_done 684 685/* 686 * Is it a disconnect message? Set a flag in the SCB to remind us 687 * and await the bus going free. 688 */ 689mesgin_disconnect: 690 or SCB_CONTROL,DISCONNECTED 691 test FLAGS, PAGESCBS jz mesgin_done 692/* 693 * Link this SCB into the DISCONNECTED list. This list holds the 694 * candidates for paging out an SCB if one is needed for a new command. 695 * Modifying the disconnected list is a critical(pause dissabled) section. 696 */ 697 mvi SCB_PREV, SCB_LIST_NULL 698 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 699 mov SCB_NEXT, DISCONNECTED_SCBH 700 mov DISCONNECTED_SCBH, SCBPTR 701 cmp SCB_NEXT,SCB_LIST_NULL je linkdone 702 mov SCBPTR,SCB_NEXT 703 mov SCB_PREV,DISCONNECTED_SCBH 704 mov SCBPTR,DISCONNECTED_SCBH 705linkdone: 706 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 707 jmp mesgin_done 708 709/* 710 * Save data pointers message? Copy working values into the SCB, 711 * usually in preparation for a disconnect. 712 */ 713mesgin_sdptrs: 714 call sg_ram2scb 715 jmp mesgin_done 716 717/* 718 * Restore pointers message? Data pointers are recopied from the 719 * SCB anytime we enter a data phase for the first time, so all 720 * we need to do is clear the DPHASE flag and let the data phase 721 * code do the rest. 722 */ 723mesgin_rdptrs: 724 and FLAGS,0xef /* 725 * !DPHASE we'll reload them 726 * the next time through 727 */ 728 jmp mesgin_done 729 730/* 731 * Identify message? For a reconnecting target, this tells us the lun 732 * that the reconnection is for - find the correct SCB and switch to it, 733 * clearing the "disconnected" bit so we don't "find" it by accident later. 734 */ 735mesgin_identify: 736 test A,0x78 jnz rej_mesgin /*!DiscPriv|!LUNTAR|!Reserved*/ 737 738 and A,0x07 /* lun in lower three bits */ 739 or SAVED_TCL,A,SELID 740 and SAVED_TCL,0xf7 741 and A,SELBUSB,SBLKCTL /* B Channel?? */ 742 or SAVED_TCL,A 743 call inb_last /* ACK */ 744 745/* 746 * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message. 747 * If we get one, we use the tag returned to switch to find the proper 748 * SCB. With SCB paging, this requires using findSCB for both tagged 749 * and non-tagged transactions since the SCB may exist in any slot. 750 * If we're not using SCB paging, we can use the tag as the direct 751 * index to the SCB. 752 */ 753 mvi ARG_1,SCB_LIST_NULL /* Default to no-tag */ 754snoop_tag_loop: 755 test SSTAT1,BUSFREE jnz use_findSCB 756 test SSTAT1,REQINIT jz snoop_tag_loop 757 test SSTAT1,PHASEMIS jnz use_findSCB 758 mvi A call inb_first 759 cmp A,MSG_SIMPLE_TAG jne use_findSCB 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 test FLAGS, PAGESCBS jz index_by_tag 776 call inb_last /* Ack Tag */ 777use_findSCB: 778 mov ALLZEROS call findSCB /* Have to search */ 779setup_SCB: 780 and SCB_CONTROL,0xfb /* clear disconnect bit in SCB */ 781 or FLAGS,IDENTIFY_SEEN /* make note of IDENTIFY */ 782 jmp ITloop 783index_by_tag: 784 mov SCBPTR,ARG_1 785 mov A,SAVED_TCL 786 cmp SCB_TCL,A jne abort_tag 787 test SCB_CONTROL,TAG_ENB jz abort_tag 788 call inb_last /* Ack Successful tag */ 789 jmp setup_SCB 790 791abort_tag: 792 or SCSISIGO,ATNO /* turn on ATNO */ 793 mvi INTSTAT,ABORT_TAG /* let driver know */ 794 mvi MSG_ABORT_TAG call mk_mesg /* ABORT TAG message */ 795 jmp mesgin_done 796 797/* 798 * Message reject? Let the kernel driver handle this. If we have an 799 * outstanding WDTR or SDTR negotiation, assume that it's a response from 800 * the target selecting 8bit or asynchronous transfer, otherwise just ignore 801 * it since we have no clue what it pertains to. 802 */ 803mesgin_reject: 804 mvi INTSTAT, REJECT_MSG 805 jmp mesgin_done 806 807/* 808 * [ ADD MORE MESSAGE HANDLING HERE ] 809 */ 810 811/* 812 * Bus free phase. It might be useful to interrupt the device 813 * driver if we aren't expecting this. For now, make sure that 814 * ATN isn't being asserted and look for a new command. 815 */ 816p_busfree: 817 mvi CLRSINT1,CLRATNO 818 clr LASTPHASE 819 820/* 821 * if this is an immediate command, perform a psuedo command complete to 822 * notify the driver. 823 */ 824 test SCB_CMDLEN,0xff jz status_ok 825 jmp start 826 827/* 828 * Locking the driver out, build a one-byte message passed in SINDEX 829 * if there is no active message already. SINDEX is returned intact. 830 */ 831mk_mesg: 832 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 833 test MSG_LEN,0xff jz mk_mesg1 /* Should always succeed */ 834 835 /* 836 * Hmmm. For some reason the mesg buffer is in use. 837 * Tell the driver. It should look at SINDEX to find 838 * out what we wanted to use the buffer for and resolve 839 * the conflict. 840 */ 841 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 842 mvi INTSTAT,MSG_BUFFER_BUSY 843 844mk_mesg1: 845 mvi MSG_LEN,1 /* length = 1 */ 846 mov MSG0,SINDEX /* 1-byte message */ 847 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 848 849/* 850 * Functions to read data in Automatic PIO mode. 851 * 852 * According to Adaptec's documentation, an ACK is not sent on input from 853 * the target until SCSIDATL is read from. So we wait until SCSIDATL is 854 * latched (the usual way), then read the data byte directly off the bus 855 * using SCSIBUSL. When we have pulled the ATN line, or we just want to 856 * acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI 857 * spec guarantees that the target will hold the data byte on the bus until 858 * we send our ACK. 859 * 860 * The assumption here is that these are called in a particular sequence, 861 * and that REQ is already set when inb_first is called. inb_{first,next} 862 * use the same calling convention as inb. 863 */ 864 865inb_next: 866 or CLRSINT0, CLRSPIORDY 867 mov NONE,SCSIDATL /*dummy read from latch to ACK*/ 868inb_next_wait: 869 test SSTAT0,SPIORDY jz inb_next_wait /* wait for next byte */ 870 test SSTAT1,PHASEMIS jnz mesgin_phasemis 871inb_first: 872 mov DINDEX,SINDEX 873 mov DINDIR,SCSIBUSL ret /*read byte directly from bus*/ 874inb_last: 875 mov NONE,SCSIDATL ret /*dummy read from latch to ACK*/ 876 877mesgin_phasemis: 878/* 879 * We expected to receive another byte, but the target changed phase 880 */ 881 mvi INTSTAT, MSGIN_PHASEMIS 882 jmp ITloop 883 884/* 885 * DMA data transfer. HADDR and HCNT must be loaded first, and 886 * SINDEX should contain the value to load DFCNTRL with - 0x3d for 887 * host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared 888 * during initialization. 889 */ 890dma: 891 mov DFCNTRL,SINDEX 892dma1: 893 test SSTAT0,DMADONE jnz dma3 894 test SSTAT1,PHASEMIS jz dma1 /* ie. underrun */ 895 896/* 897 * We will be "done" DMAing when the transfer count goes to zero, or 898 * the target changes the phase (in light of this, it makes sense that 899 * the DMA circuitry doesn't ACK when PHASEMIS is active). If we are 900 * doing a SCSI->Host transfer, the data FIFO should be flushed auto- 901 * magically on STCNT=0 or a phase change, so just wait for FIFO empty 902 * status. 903 */ 904dma3: 905 test SINDEX,DIRECTION jnz dma5 906dma4: 907 test DFSTATUS,FIFOEMP jz dma4 908 909/* 910 * Now shut the DMA enables off and make sure that the DMA enables are 911 * actually off first lest we get an ILLSADDR. 912 */ 913dma5: 914 /* disable DMA, but maintain WIDEODD */ 915 and DFCNTRL,WIDEODD 916dma6: 917 test DFCNTRL,0x38 jnz dma6 /* SCSIENACK|SDMAENACK|HDMAENACK */ 918 919 ret 920 921/* 922 * Common SCSI initialization for selection and reselection. Expects 923 * the target SCSI ID to be in the upper four bits of SINDEX, and A's 924 * contents are stomped on return. 925 */ 926initialize_scsiid: 927 and SINDEX,0xf0 /* Get target ID */ 928 and A,0x0f,SCSIID 929 or SINDEX,A 930 mov SCSIID,SINDEX ret 931 932/* 933 * Assert that if we've been reselected, then we've seen an IDENTIFY 934 * message. 935 */ 936assert: 937 test FLAGS,RESELECTED jz return /* reselected? */ 938 test FLAGS,IDENTIFY_SEEN jnz return /* seen IDENTIFY? */ 939 940 mvi INTSTAT,NO_IDENT ret /* no - cause a kernel panic */ 941 942/* 943 * Locate the SCB matching the target ID/channel/lun in SAVED_TCL, and the tag 944 * value in ARG_1. If ARG_1 == SCB_LIST_NULL, we're looking for a non-tagged 945 * SCB. Have the kernel print a warning message if it can't be found, and 946 * generate an ABORT/ABORT_TAG message to the target. SINDEX should be 947 * cleared on call. 948 */ 949findSCB: 950 mov A,SAVED_TCL 951 mov SCBPTR,SINDEX /* switch to next SCB */ 952 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 953 cmp SCB_TCL,A jne findSCB1 /* target ID/channel/lun match? */ 954 test SCB_CONTROL,DISCONNECTED jz findSCB1 /*should be disconnected*/ 955 test SCB_CONTROL,TAG_ENB jnz findTaggedSCB 956 cmp ARG_1,SCB_LIST_NULL je foundSCB 957 jmp findSCB1 958findTaggedSCB: 959 mov A, ARG_1 /* Tag passed in ARG_1 */ 960 cmp SCB_TAG,A jne findSCB1 /* Found it? */ 961foundSCB: 962 test FLAGS,PAGESCBS jz foundSCB_ret 963/* Remove this SCB from the disconnection list */ 964 cmp SCB_NEXT,SCB_LIST_NULL je unlink_prev 965 mov SAVED_LINKPTR, SCB_PREV 966 mov SCBPTR, SCB_NEXT 967 mov SCB_PREV, SAVED_LINKPTR 968 mov SCBPTR, SINDEX 969unlink_prev: 970 cmp SCB_PREV,SCB_LIST_NULL je rHead/* At the head of the list */ 971 mov SAVED_LINKPTR, SCB_NEXT 972 mov SCBPTR, SCB_PREV 973 mov SCB_NEXT, SAVED_LINKPTR 974 mov SCBPTR, SINDEX 975 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 976rHead: 977 mov DISCONNECTED_SCBH,SCB_NEXT 978foundSCB_ret: 979 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 980 981findSCB1: 982 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 983 inc SINDEX 984 mov A,SCBCOUNT 985 cmp SINDEX,A jne findSCB 986 987 mvi INTSTAT,NO_MATCH /* not found - signal kernel */ 988 cmp RETURN_1,SCB_PAGEDIN je return 989 or SCSISIGO,ATNO /* assert ATNO */ 990 cmp ARG_1,SCB_LIST_NULL jne find_abort_tag 991 mvi MSG_ABORT call mk_mesg 992 jmp ITloop 993find_abort_tag: 994 mvi MSG_ABORT_TAG call mk_mesg 995 jmp ITloop 996 997/* 998 * Make a working copy of the scatter-gather parameters from the SCB. 999 */ 1000sg_scb2ram: 1001 mov HADDR0, SCB_DATAPTR0 1002 mov HADDR1, SCB_DATAPTR1 1003 mov HADDR2, SCB_DATAPTR2 1004 mov HADDR3, SCB_DATAPTR3 1005 mov HCNT0, SCB_DATACNT0 1006 mov HCNT1, SCB_DATACNT1 1007 mov HCNT2, SCB_DATACNT2 1008 1009 mov STCNT0, HCNT0 1010 mov STCNT1, HCNT1 1011 mov STCNT2, HCNT2 1012 1013 mov SG_COUNT,SCB_SGCOUNT 1014 1015 mov SG_NEXT0, SCB_SGPTR0 1016 mov SG_NEXT1, SCB_SGPTR1 1017 mov SG_NEXT2, SCB_SGPTR2 1018 mov SG_NEXT3, SCB_SGPTR3 ret 1019 1020/* 1021 * Copying RAM values back to SCB, for Save Data Pointers message, but 1022 * only if we've actually been into a data phase to change them. This 1023 * protects against bogus data in scratch ram and the residual counts 1024 * since they are only initialized when we go into data_in or data_out. 1025 */ 1026sg_ram2scb: 1027 test FLAGS, DPHASE jz return 1028 mov SCB_SGCOUNT,SG_COUNT 1029 1030 mov SCB_SGPTR0,SG_NEXT0 1031 mov SCB_SGPTR1,SG_NEXT1 1032 mov SCB_SGPTR2,SG_NEXT2 1033 mov SCB_SGPTR3,SG_NEXT3 1034 1035 mov SCB_DATAPTR0,SHADDR0 1036 mov SCB_DATAPTR1,SHADDR1 1037 mov SCB_DATAPTR2,SHADDR2 1038 mov SCB_DATAPTR3,SHADDR3 1039 1040/* 1041 * Use the residual number since STCNT is corrupted by any message transfer 1042 */ 1043 mov SCB_DATACNT0,SCB_RESID_DCNT0 1044 mov SCB_DATACNT1,SCB_RESID_DCNT1 1045 mov SCB_DATACNT2,SCB_RESID_DCNT2 ret 1046 1047/* 1048 * Add the array base TARG_SCRATCH to the target offset (the target address 1049 * is in SCSIID), and return the result in SINDEX. The accumulator 1050 * contains the 3->8 decoding of the target ID on return. 1051 */ 1052ndx_dtr: 1053 shr A,SCSIID,4 1054 test SBLKCTL,SELBUSB jz ndx_dtr_2 1055 or A,0x08 /* Channel B entries add 8 */ 1056ndx_dtr_2: 1057 add SINDEX,TARG_SCRATCH,A ret 1058 1059/* 1060 * If we need to negotiate transfer parameters, build the WDTR or SDTR message 1061 * starting at the address passed in SINDEX. DINDEX is modified on return. 1062 * The SCSI-II spec requires that Wide negotiation occur first and you can 1063 * only negotiat one or the other at a time otherwise in the event of a message 1064 * reject, you wouldn't be able to tell which message was the culpret. 1065 */ 1066mk_dtr: 1067 test SCB_CONTROL,NEEDWDTR jnz mk_wdtr_16bit 1068 mvi ARG_1, MAXOFFSET /* Force an offset of 15 or 8 if WIDE */ 1069 1070mk_sdtr: 1071 mvi DINDIR,1 /* extended message */ 1072 mvi DINDIR,3 /* extended message length = 3 */ 1073 mvi DINDIR,1 /* SDTR code */ 1074 call sdtr_to_rate 1075 mov DINDIR,RETURN_1 /* REQ/ACK transfer period */ 1076 cmp ARG_1, MAXOFFSET je mk_sdtr_max_offset 1077 and DINDIR,0x0f,SINDIR /* Sync Offset */ 1078 1079mk_sdtr_done: 1080 add MSG_LEN,COMP_MSG0,DINDEX ret /* update message length */ 1081 1082mk_sdtr_max_offset: 1083/* 1084 * We're initiating sync negotiation, so request the max offset we can (15 or 8) 1085 */ 1086 /* Talking to a WIDE device? */ 1087 test SCSIRATE, WIDEXFER jnz wmax_offset 1088 mvi DINDIR, MAX_OFFSET_8BIT 1089 jmp mk_sdtr_done 1090 1091wmax_offset: 1092 mvi DINDIR, MAX_OFFSET_16BIT 1093 jmp mk_sdtr_done 1094 1095mk_wdtr_16bit: 1096 mvi ARG_1,BUS_16_BIT 1097mk_wdtr: 1098 mvi DINDIR,1 /* extended message */ 1099 mvi DINDIR,2 /* extended message length = 2 */ 1100 mvi DINDIR,3 /* WDTR code */ 1101 mov DINDIR,ARG_1 /* bus width */ 1102 1103 add MSG_LEN,COMP_MSG0,DINDEX ret /* update message length */ 1104 1105sdtr_to_rate: 1106 call ndx_dtr /* index scratch space for target */ 1107 shr A,SINDIR,0x4 1108 dec SINDEX /* Preserve SINDEX */ 1109 and A,0x7 1110 clr RETURN_1 1111sdtr_to_rate_loop: 1112 test A,0x0f jz sdtr_to_rate_done 1113 add RETURN_1,0x19 1114 dec A 1115 jmp sdtr_to_rate_loop 1116sdtr_to_rate_done: 1117 shr RETURN_1,0x2 1118 add RETURN_1,0x19 1119 test SXFRCTL0,ULTRAEN jz return 1120 shr RETURN_1,0x1 1121return: 1122 ret 1123