aic7xxx.seq revision 15843
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 1.34 1996/05/10 16:11:01 gibbs Exp $" 43 44#include "../../dev/aic7xxx/aic7xxx_reg.h" 45 46/* 47 * We can't just use ACCUM in the sequencer code because it 48 * must be treated specially by the assembler, and it currently 49 * looks for the symbol 'A'. This is the only register defined in 50 * the assembler's symbol space. 51 */ 52A = ACCUM 53 54/* After starting the selection hardware, we check for reconnecting targets 55 * as well as for our selection to complete just in case the reselection wins 56 * bus arbitration. The problem with this is that we must keep track of the 57 * SCB that we've already pulled from the QINFIFO and started the selection 58 * on just in case the reselection wins so that we can retry the selection at 59 * a later time. This problem cannot be resolved by holding a single entry 60 * in scratch ram since a reconnecting target can request sense and this will 61 * create yet another SCB waiting for selection. The solution used here is to 62 * use byte 27 of the SCB as a psuedo-next pointer and to thread a list 63 * of SCBs that are awaiting selection. Since 0-0xfe are valid SCB offsets, 64 * SCB_LIST_NULL is 0xff which is out of range. The kernel driver must 65 * add an entry to this list everytime a request sense occurs. The sequencer 66 * will automatically consume the entries. 67 */ 68 69/* 70 * We assume that the kernel driver may reset us at any time, even in the 71 * middle of a DMA, so clear DFCNTRL too. 72 */ 73reset: 74 clr DFCNTRL 75 clr SCSISIGO /* De-assert BSY */ 76/* 77 * We jump to start after every bus free. 78 */ 79start: 80 and FLAGS,0x0f /* clear target specific flags */ 81 mvi SCSISEQ,ENRSELI /* Always allow reselection */ 82poll_for_work: 83 /* 84 * Are we a twin channel device? 85 * For fairness, we check the other bus first, 86 * since we just finished a transaction on the 87 * current channel. 88 */ 89 test FLAGS,TWIN_BUS jz start2 90 xor SBLKCTL,SELBUSB /* Toggle to the other bus */ 91 test SSTAT0,SELDI jnz reselect 92 xor SBLKCTL,SELBUSB /* Toggle to the original bus */ 93start2: 94 test SSTAT0,SELDI jnz reselect 95 cmp WAITING_SCBH,SCB_LIST_NULL jne start_waiting 96 mov A, QCNTMASK 97 test QINCNT,A jz poll_for_work 98 99/* 100 * We have at least one queued SCB now and we don't have any 101 * SCBs in the list of SCBs awaiting selection. Set the SCB 102 * pointer from the FIFO so we see the right bank of SCB 103 * registers. 104 */ 105 mov SCBPTR,QINFIFO 106 107/* 108 * See if there is not already an active SCB for this target. This code 109 * locks out on a per target basis instead of target/lun. Although this 110 * is not ideal for devices that have multiple luns active at the same 111 * time, it is faster than looping through all SCB's looking for active 112 * commands. It may be benificial to make findscb a more general procedure 113 * to see if the added cost of the search is negligible. This code also 114 * assumes that the kernel driver will clear the active flags on board 115 * initialization, board reset, and a target SELTO. Tagged commands 116 * don't set the active bits since you can queue more than one command 117 * at a time. We do, however, look to see if there are any non-tagged 118 * I/Os in progress, and requeue the command if there are. Tagged and 119 * non-tagged commands cannot be mixed to a single target. 120 */ 121 122test_busy: 123 mov FUNCTION1,SCB_TCL 124 mov A,FUNCTION1 125 test SCB_TCL,0x88 jz test_a /* Id < 8 && A channel */ 126 127 test ACTIVE_B,A jnz requeue 128 test SCB_CONTROL,TAG_ENB jnz start_scb 129 /* Mark the current target as busy */ 130 or ACTIVE_B,A 131 jmp start_scb 132 133/* Place the currently active SCB back on the queue for later processing */ 134requeue: 135 mov QINFIFO, SCBPTR 136 jmp poll_for_work 137 138/* 139 * Pull the first entry off of the waiting for selection list 140 * We don't have to "test_busy" because only transactions that 141 * have passed that test can be in the waiting_scb list. 142 */ 143start_waiting: 144 mov SCBPTR,WAITING_SCBH 145 jmp start_scb2 146 147test_a: 148 test ACTIVE_A,A jnz requeue 149 test SCB_CONTROL,TAG_ENB jnz start_scb 150 /* Mark the current target as busy */ 151 or ACTIVE_A,A 152 153start_scb: 154 mov SCB_NEXT,WAITING_SCBH 155 mov WAITING_SCBH, SCBPTR 156start_scb2: 157 and SINDEX,0xf7,SBLKCTL /* Clear the channel select bit */ 158 and A,0x08,SCB_TCL /* Get new channel bit */ 159 or SINDEX,A 160 mov SBLKCTL,SINDEX /* select channel */ 161 mov SCB_TCL call initialize_scsiid 162 163/* 164 * Enable selection phase as an initiator, and do automatic ATN 165 * after the selection. We do this now so that we can overlap the 166 * rest of our work to set up this target with the arbitration and 167 * selection bus phases. 168 */ 169start_selection: 170 mvi SCSISEQ,0x58 /* ENSELO|ENAUTOATNO|ENRSELI */ 171 172/* 173 * As soon as we get a successful selection, the target should go 174 * into the message out phase since we have ATN asserted. Prepare 175 * the message to send. 176 * 177 * Messages are stored in scratch RAM starting with a length byte 178 * followed by the message itself. 179 */ 180 test SCB_CMDLEN,0xff jnz mk_identify /* 0 Length Command? */ 181 182/* 183 * The kernel has sent us an SCB with no command attached. This implies 184 * that the kernel wants to send a message of some sort to this target, 185 * so we interrupt the driver, allow it to fill the message buffer, and 186 * then go back into the arbitration loop 187 */ 188 mvi INTSTAT,AWAITING_MSG 189 jmp wait_for_selection 190 191mk_identify: 192 and A,DISCENB,SCB_CONTROL /* mask off disconnect privledge */ 193 194 and MSG0,0x7,SCB_TCL /* lun */ 195 or MSG0,A /* or in disconnect privledge */ 196 or MSG0,MSG_IDENTIFY 197 mvi MSG_LEN, 1 198 199 test SCB_CONTROL,0xb0 jz !message /* WDTR, SDTR or TAG?? */ 200/* 201 * Send a tag message if TAG_ENB is set in the SCB control block. 202 * Use SCB_TAG (the position in the kernel's SCB array) as the tag value. 203 */ 204 205mk_tag: 206 mvi DINDEX, MSG1 207 test SCB_CONTROL,TAG_ENB jz mk_tag_done 208 and DINDIR,0x23,SCB_CONTROL 209 mov DINDIR,SCB_TAG 210 211 add MSG_LEN,COMP_MSG0,DINDEX /* update message length */ 212 213mk_tag_done: 214 215 test SCB_CONTROL,0x90 jz !message /* NEEDWDTR|NEEDSDTR */ 216 mov DINDEX call mk_dtr /* build DTR message if needed */ 217 218!message: 219wait_for_selection: 220 test SSTAT0,SELDO jnz select 221 test SSTAT0,SELDI jz wait_for_selection 222 223/* 224 * Reselection has been initiated by a target. Make a note that we've been 225 * reselected, but haven't seen an IDENTIFY message from the target 226 * yet. 227 */ 228reselect: 229 clr MSG_LEN /* Don't have anything in the mesg buffer */ 230 mov SELID call initialize_scsiid 231 or FLAGS,RESELECTED 232 jmp select2 233 234/* 235 * After the selection, remove this SCB from the "waiting for selection" 236 * list. This is achieved by simply moving our "next" pointer into 237 * WAITING_SCBH. Our next pointer will be set to null the next time this 238 * SCB is used, so don't bother with it now. 239 */ 240select: 241 mov WAITING_SCBH,SCB_NEXT 242 or FLAGS,SELECTED 243select2: 244/* 245 * Set CLRCHN here before the target has entered a data transfer mode - 246 * with synchronous SCSI, if you do it later, you blow away some 247 * data in the SCSI FIFO that the target has already sent to you. 248 */ 249 or SXFRCTL0,CLRCHN 250/* 251 * Initialize SCSIRATE with the appropriate value for this target. 252 */ 253 call ndx_dtr 254 mov SCSIRATE,SINDIR 255 256/* 257 * Initialize Ultra mode setting. ndx_dtr has left our target mask 258 * in A. 259 */ 260 and SINDEX,0xdf,SXFRCTL0 /* default to Ultra disabled */ 261 test SCSIID, 0x80 jnz ultra_b /* Target ID > 7 */ 262 test SBLKCTL, SELBUSB jnz ultra_b /* Second channel device */ 263 test ULTRA_ENB,A jz set_sxfrctl0 264 or SINDEX, ULTRAEN jmp set_sxfrctl0 265ultra_b: 266 test ULTRA_ENB_B,A jz set_sxfrctl0 267 or SINDEX, ULTRAEN 268 269set_sxfrctl0: 270 mov SXFRCTL0,SINDEX 271 272 mvi SCSISEQ,ENAUTOATNP /* 273 * ATN on parity errors 274 * for "in" phases 275 */ 276 mvi CLRSINT1,CLRBUSFREE 277 mvi CLRSINT0,0x60 /* CLRSELDI|CLRSELDO */ 278/* 279 * Main loop for information transfer phases. If BSY is false, then 280 * we have a bus free condition, expected or not. Otherwise, wait 281 * for the target to assert REQ before checking MSG, C/D and I/O 282 * for the bus phase. 283 * 284 */ 285ITloop: 286 test SSTAT1,BUSFREE jnz p_busfree 287 test SSTAT1,REQINIT jz ITloop 288 289 and A,PHASE_MASK,SCSISIGI 290 mov LASTPHASE,A 291 mov SCSISIGO,A 292 293 cmp ALLZEROS,A je p_dataout 294 cmp A,P_DATAIN je p_datain 295 cmp A,P_COMMAND je p_command 296 cmp A,P_MESGOUT je p_mesgout 297 cmp A,P_STATUS je p_status 298 cmp A,P_MESGIN je p_mesgin 299 300 mvi INTSTAT,BAD_PHASE /* unknown phase - signal driver */ 301 jmp ITloop /* Try reading the bus again. */ 302 303p_dataout: 304 mvi DMAPARAMS,0x7d /* 305 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 306 * DIRECTION|FIFORESET 307 */ 308 jmp data_phase_init 309 310/* 311 * If we re-enter the data phase after going through another phase, the 312 * STCNT may have been cleared, so restore it from the residual field. 313 */ 314data_phase_reinit: 315 mov STCNT0,SCB_RESID_DCNT0 316 mov STCNT1,SCB_RESID_DCNT1 317 mov STCNT2,SCB_RESID_DCNT2 318 jmp data_phase_loop 319 320p_datain: 321 mvi DMAPARAMS,0x79 /* 322 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 323 * !DIRECTION|FIFORESET 324 */ 325data_phase_init: 326 call assert 327 328 test FLAGS, DPHASE jnz data_phase_reinit 329 call sg_scb2ram 330 or FLAGS, DPHASE /* We have seen a data phase */ 331 332data_phase_loop: 333/* If we are the last SG block, don't set wideodd. */ 334 cmp SG_COUNT,0x01 jne data_phase_wideodd 335 and DMAPARAMS, 0xbf /* Turn off WIDEODD */ 336data_phase_wideodd: 337 mov DMAPARAMS call dma 338 339/* Exit if we had an underrun */ 340 test SSTAT0,SDONE jz data_phase_finish /* underrun STCNT != 0 */ 341 342/* 343 * Advance the scatter-gather pointers if needed 344 */ 345sg_advance: 346 dec SG_COUNT /* one less segment to go */ 347 348 test SG_COUNT, 0xff jz data_phase_finish /* Are we done? */ 349 350 clr A /* add sizeof(struct scatter) */ 351 add SG_NEXT0,SG_SIZEOF,SG_NEXT0 352 adc SG_NEXT1,A,SG_NEXT1 353 354/* 355 * Load a struct scatter and set up the data address and length. 356 * If the working value of the SG count is nonzero, then 357 * we need to load a new set of values. 358 * 359 * This, like all DMA's, assumes little-endian host data storage. 360 */ 361sg_load: 362 clr HCNT2 363 clr HCNT1 364 mvi HCNT0,SG_SIZEOF 365 366 mov HADDR0,SG_NEXT0 367 mov HADDR1,SG_NEXT1 368 mov HADDR2,SG_NEXT2 369 mov HADDR3,SG_NEXT3 370 371 or DFCNTRL,0xd /* HDMAEN|DIRECTION|FIFORESET */ 372 373/* 374 * Wait for DMA from host memory to data FIFO to complete, then disable 375 * DMA and wait for it to acknowledge that it's off. 376 */ 377dma_finish: 378 test DFSTATUS,HDONE jz dma_finish 379 /* Turn off DMA preserving WIDEODD */ 380 and DFCNTRL,WIDEODD 381dma_finish2: 382 test DFCNTRL,HDMAENACK jnz dma_finish2 383 384/* 385 * Copy data from FIFO into SCB data pointer and data count. This assumes 386 * that the struct scatterlist has this structure (this and sizeof(struct 387 * scatterlist) == 12 are asserted in aic7xxx.c for the Linux driver): 388 * 389 * struct scatterlist { 390 * char *address; four bytes, little-endian order 391 * ... four bytes, ignored 392 * unsigned short length; two bytes, little-endian order 393 * } 394 * 395 * 396 * In FreeBSD, the scatter list entry is only 8 bytes. 397 * 398 * struct ahc_dma_seg { 399 * physaddr addr; four bytes, little-endian order 400 * long len; four bytes, little endian order 401 * }; 402 */ 403 404 mov HADDR0,DFDAT 405 mov HADDR1,DFDAT 406 mov HADDR2,DFDAT 407 mov HADDR3,DFDAT 408/* 409 * For Linux, we must throw away four bytes since there is a 32bit gap 410 * in the middle of a struct scatterlist. 411 */ 412#ifdef __linux__ 413 mov NONE,DFDAT 414 mov NONE,DFDAT 415 mov NONE,DFDAT 416 mov NONE,DFDAT 417#endif 418 mov HCNT0,DFDAT 419 mov HCNT1,DFDAT 420 mov HCNT2,DFDAT 421 422/* Load STCNT as well. It is a mirror of HCNT */ 423 mov STCNT0,HCNT0 424 mov STCNT1,HCNT1 425 mov STCNT2,HCNT2 426 test SSTAT1,PHASEMIS jz data_phase_loop 427 428data_phase_finish: 429/* 430 * After a DMA finishes, save the SG and STCNT residuals back into the SCB 431 * We use STCNT instead of HCNT, since it's a reflection of how many bytes 432 * were transferred on the SCSI (as opposed to the host) bus. 433 */ 434 mov SCB_RESID_DCNT0,STCNT0 435 mov SCB_RESID_DCNT1,STCNT1 436 mov SCB_RESID_DCNT2,STCNT2 437 mov SCB_RESID_SGCNT, SG_COUNT 438 jmp ITloop 439 440/* 441 * Command phase. Set up the DMA registers and let 'er rip. 442 */ 443p_command: 444 call assert 445 446/* 447 * Load HADDR and HCNT. 448 */ 449 mov HADDR0, SCB_CMDPTR0 450 mov HADDR1, SCB_CMDPTR1 451 mov HADDR2, SCB_CMDPTR2 452 mov HADDR3, SCB_CMDPTR3 453 mov HCNT0, SCB_CMDLEN 454 clr HCNT1 455 clr HCNT2 456 457 mov STCNT0, HCNT0 458 mov STCNT1, HCNT1 459 mov STCNT2, HCNT2 460 461 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 462 # DIRECTION|FIFORESET 463 jmp ITloop 464 465/* 466 * Status phase. Wait for the data byte to appear, then read it 467 * and store it into the SCB. 468 */ 469p_status: 470 mvi SCB_TARGET_STATUS call inb_first 471 jmp mesgin_done 472 473/* 474 * Message out phase. If there is not an active message, but the target 475 * took us into this phase anyway, build a no-op message and send it. 476 */ 477p_mesgout: 478 test MSG_LEN, 0xff jnz p_mesgout_start 479 mvi MSG_NOP call mk_mesg /* build NOP message */ 480 481p_mesgout_start: 482/* 483 * Set up automatic PIO transfer from MSG0. Bit 3 in 484 * SXFRCTL0 (SPIOEN) is already on. 485 */ 486 mvi SINDEX,MSG0 487 mov DINDEX,MSG_LEN 488 489/* 490 * When target asks for a byte, drop ATN if it's the last one in 491 * the message. Otherwise, keep going until the message is exhausted. 492 * 493 * Keep an eye out for a phase change, in case the target issues 494 * a MESSAGE REJECT. 495 */ 496p_mesgout_loop: 497 test SSTAT1,PHASEMIS jnz p_mesgout_phasemis 498 test SSTAT0,SPIORDY jz p_mesgout_loop 499 cmp DINDEX,1 jne p_mesgout_outb /* last byte? */ 500 mvi CLRSINT1,CLRATNO /* drop ATN */ 501p_mesgout_outb: 502 dec DINDEX 503 or CLRSINT0, CLRSPIORDY 504 mov SCSIDATL,SINDIR 505 506p_mesgout4: 507 test DINDEX,0xff jnz p_mesgout_loop 508 509/* 510 * If the next bus phase after ATN drops is a message out, it means 511 * that the target is requesting that the last message(s) be resent. 512 */ 513p_mesgout_snoop: 514 test SSTAT1,BUSFREE jnz p_mesgout_done 515 test SSTAT1,REQINIT jz p_mesgout_snoop 516 517 test SSTAT1,PHASEMIS jnz p_mesgout_done 518 519 or SCSISIGO,ATNO /* turn on ATNO */ 520 521 jmp ITloop 522 523p_mesgout_phasemis: 524 mvi CLRSINT1,CLRATNO /* Be sure to turn ATNO off */ 525p_mesgout_done: 526 clr MSG_LEN /* no active msg */ 527 jmp ITloop 528 529/* 530 * Message in phase. Bytes are read using Automatic PIO mode. 531 */ 532p_mesgin: 533 mvi A call inb_first /* read the 1st message byte */ 534 mov REJBYTE,A /* save it for the driver */ 535 536 test A,MSG_IDENTIFY jnz mesgin_identify 537 cmp A,MSG_DISCONNECT je mesgin_disconnect 538 cmp A,MSG_SDPTRS je mesgin_sdptrs 539 cmp ALLZEROS,A je mesgin_complete 540 cmp A,MSG_RDPTRS je mesgin_rdptrs 541 cmp A,MSG_EXTENDED je mesgin_extended 542 cmp A,MSG_REJECT je mesgin_reject 543 544rej_mesgin: 545/* 546 * We have no idea what this message in is, and there's no way 547 * to pass it up to the kernel, so we issue a message reject and 548 * hope for the best. Since we're now using manual PIO mode to 549 * read in the message, there should no longer be a race condition 550 * present when we assert ATN. In any case, rejection should be a 551 * rare occurrence - signal the driver when it happens. 552 */ 553 or SCSISIGO,ATNO /* turn on ATNO */ 554 mvi INTSTAT,SEND_REJECT /* let driver know */ 555 556 mvi MSG_REJECT call mk_mesg 557 558mesgin_done: 559 call inb_last /*ack & turn auto PIO back on*/ 560 jmp ITloop 561 562 563mesgin_complete: 564/* 565 * We got a "command complete" message, so put the SCB_TAG into QUEUEOUT, 566 * and trigger a completion interrupt. Check status for non zero return 567 * and interrupt driver if needed. This allows the driver to interpret 568 * errors only when they occur instead of always uploading the scb. If 569 * the status is SCSI_CHECK, the driver will download a new scb requesting 570 * sense to replace the old one, modify the "waiting for selection" SCB list 571 * and set RETURN_1 to SEND_SENSE. If RETURN_1 is set to SEND_SENSE the 572 * sequencer imediately jumps to main loop where it will run down the waiting 573 * SCB list and process the sense request. If the kernel driver does not 574 * wish to request sense, it need only clear RETURN_1, and the command is 575 * allowed to complete. We don't bother to post to the QOUTFIFO in the 576 * error case since it would require extra work in the kernel driver to 577 * ensure that the entry was removed before the command complete code tried 578 * processing it. 579 * 580 * First check for residuals 581 */ 582 test SCB_RESID_SGCNT,0xff jz check_status 583/* 584 * If we have a residual count, interrupt and tell the host. Other 585 * alternatives are to pause the sequencer on all command completes (yuck), 586 * dma the resid directly to the host (slick, we may have space to do it now) 587 * or have the sequencer pause itself when it encounters a non-zero resid 588 * (unecessary pause just to flag the command -yuck-, but takes one instruction 589 * and since it shouldn't happen that often is good enough for our purposes). 590 */ 591resid: 592 mvi INTSTAT,RESIDUAL 593 594check_status: 595 test SCB_TARGET_STATUS,0xff jz status_ok /* Good Status? */ 596 mvi INTSTAT,BAD_STATUS /* let driver know */ 597 cmp RETURN_1, SEND_SENSE jne status_ok 598 jmp mesgin_done 599 600status_ok: 601/* First, mark this target as free. */ 602 test SCB_CONTROL,TAG_ENB jnz test_immediate /* 603 * Tagged commands 604 * don't busy the 605 * target. 606 */ 607 mov FUNCTION1,SCB_TCL 608 mov A,FUNCTION1 609 test SCB_TCL,0x88 jz clear_a 610 xor ACTIVE_B,A 611 jmp test_immediate 612 613clear_a: 614 xor ACTIVE_A,A 615 616test_immediate: 617 test SCB_CMDLEN,0xff jnz complete /* Immediate message complete */ 618/* 619 * Pause the sequencer until the driver gets around to handling the command 620 * complete. This is so that any action that might require carefull timing 621 * with the completion of this command can occur. 622 */ 623 mvi INTSTAT,IMMEDDONE 624 jmp start 625complete: 626 mov QOUTFIFO,SCB_TAG 627 mvi INTSTAT,CMDCMPLT 628 jmp mesgin_done 629 630 631/* 632 * Is it an extended message? We only support the synchronous and wide data 633 * transfer request messages, which will probably be in response to 634 * WDTR or SDTR message outs from us. If it's not SDTR or WDTR, reject it - 635 * apparently this can be done after any message in byte, according 636 * to the SCSI-2 spec. 637 */ 638mesgin_extended: 639 mvi ARG_1 call inb_next /* extended message length */ 640 mvi REJBYTE_EXT call inb_next /* extended message code */ 641 642 cmp REJBYTE_EXT,MSG_SDTR je p_mesginSDTR 643 cmp REJBYTE_EXT,MSG_WDTR je p_mesginWDTR 644 jmp rej_mesgin 645 646p_mesginWDTR: 647 cmp ARG_1,2 jne rej_mesgin /* extended mesg length=2 */ 648 mvi ARG_1 call inb_next /* Width of bus */ 649 mvi INTSTAT,WDTR_MSG /* let driver know */ 650 test RETURN_1,0xff jz mesgin_done /* Do we need to send WDTR? */ 651 cmp RETURN_1,SEND_REJ je rej_mesgin /* 652 * Bus width was too large 653 * Reject it. 654 */ 655 656/* We didn't initiate the wide negotiation, so we must respond to the request */ 657 and RETURN_1,0x7f /* Clear the SEND_WDTR Flag */ 658 mvi DINDEX,MSG0 659 mvi MSG0 call mk_wdtr /* build WDTR message */ 660 or SCSISIGO,ATNO /* turn on ATNO */ 661 jmp mesgin_done 662 663p_mesginSDTR: 664 cmp ARG_1,3 jne rej_mesgin /* extended mesg length=3 */ 665 mvi ARG_1 call inb_next /* xfer period */ 666 mvi A call inb_next /* REQ/ACK offset */ 667 mvi INTSTAT,SDTR_MSG /* call driver to convert */ 668 669 test RETURN_1,0xff jz mesgin_done /* Do we need to mk_sdtr/rej */ 670 cmp RETURN_1,SEND_REJ je rej_mesgin /* 671 * Requested SDTR too small 672 * Reject it. 673 */ 674 clr ARG_1 /* Use the scratch ram rate */ 675 mvi DINDEX, MSG0 676 mvi MSG0 call mk_sdtr 677 or SCSISIGO,ATNO /* turn on ATNO */ 678 jmp mesgin_done 679 680/* 681 * Is it a disconnect message? Set a flag in the SCB to remind us 682 * and await the bus going free. 683 */ 684mesgin_disconnect: 685 or SCB_CONTROL,DISCONNECTED 686 test FLAGS, PAGESCBS jz mesgin_done 687/* 688 * Link this SCB into the DISCONNECTED list. This list holds the 689 * candidates for paging out an SCB if one is needed for a new command. 690 * Modifying the disconnected list is a critical(pause dissabled) section. 691 */ 692 mvi SCB_PREV, SCB_LIST_NULL 693 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 694 mov SCB_NEXT, DISCONNECTED_SCBH 695 mov DISCONNECTED_SCBH, SCBPTR 696 cmp SCB_NEXT,SCB_LIST_NULL je linkdone 697 mov SCBPTR,SCB_NEXT 698 mov SCB_PREV,DISCONNECTED_SCBH 699 mov SCBPTR,DISCONNECTED_SCBH 700linkdone: 701 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 702 jmp mesgin_done 703 704/* 705 * Save data pointers message? Copy working values into the SCB, 706 * usually in preparation for a disconnect. 707 */ 708mesgin_sdptrs: 709 call sg_ram2scb 710 jmp mesgin_done 711 712/* 713 * Restore pointers message? Data pointers are recopied from the 714 * SCB anytime we enter a data phase for the first time, so all 715 * we need to do is clear the DPHASE flag and let the data phase 716 * code do the rest. 717 */ 718mesgin_rdptrs: 719 and FLAGS,0xef /* 720 * !DPHASE we'll reload them 721 * the next time through 722 */ 723 jmp mesgin_done 724 725/* 726 * Identify message? For a reconnecting target, this tells us the lun 727 * that the reconnection is for - find the correct SCB and switch to it, 728 * clearing the "disconnected" bit so we don't "find" it by accident later. 729 */ 730mesgin_identify: 731 test A,0x78 jnz rej_mesgin /*!DiscPriv|!LUNTAR|!Reserved*/ 732 733 and A,0x07 /* lun in lower three bits */ 734 or SAVED_TCL,A,SELID 735 and SAVED_TCL,0xf7 736 and A,SELBUSB,SBLKCTL /* B Channel?? */ 737 or SAVED_TCL,A 738 call inb_last /* ACK */ 739 740/* 741 * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message. 742 * If we get one, we use the tag returned to switch to find the proper 743 * SCB. With SCB paging, this requires using findSCB for both tagged 744 * and non-tagged transactions since the SCB may exist in any slot. 745 * If we're not using SCB paging, we can use the tag as the direct 746 * index to the SCB. 747 */ 748 mvi ARG_1,SCB_LIST_NULL /* Default to no-tag */ 749snoop_tag_loop: 750 test SSTAT1,BUSFREE jnz use_findSCB 751 test SSTAT1,REQINIT jz snoop_tag_loop 752 test SSTAT1,PHASEMIS jnz use_findSCB 753 mvi A call inb_first 754 cmp A,MSG_SIMPLE_TAG jne use_findSCB 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 test FLAGS, PAGESCBS jz index_by_tag 771 call inb_last /* Ack Tag */ 772use_findSCB: 773 mov ALLZEROS call findSCB /* Have to search */ 774setup_SCB: 775 and SCB_CONTROL,0xfb /* clear disconnect bit in SCB */ 776 or FLAGS,IDENTIFY_SEEN /* make note of IDENTIFY */ 777 jmp ITloop 778index_by_tag: 779 mov SCBPTR,ARG_1 780 mov A,SAVED_TCL 781 cmp SCB_TCL,A jne abort_tag 782 test SCB_CONTROL,TAG_ENB jz abort_tag 783 call inb_last /* Ack Successful tag */ 784 jmp setup_SCB 785 786abort_tag: 787 or SCSISIGO,ATNO /* turn on ATNO */ 788 mvi INTSTAT,ABORT_TAG /* let driver know */ 789 mvi MSG_ABORT_TAG call mk_mesg /* ABORT TAG message */ 790 jmp mesgin_done 791 792/* 793 * Message reject? Let the kernel driver handle this. If we have an 794 * outstanding WDTR or SDTR negotiation, assume that it's a response from 795 * the target selecting 8bit or asynchronous transfer, otherwise just ignore 796 * it since we have no clue what it pertains to. 797 */ 798mesgin_reject: 799 mvi INTSTAT, REJECT_MSG 800 jmp mesgin_done 801 802/* 803 * [ ADD MORE MESSAGE HANDLING HERE ] 804 */ 805 806/* 807 * Bus free phase. It might be useful to interrupt the device 808 * driver if we aren't expecting this. For now, make sure that 809 * ATN isn't being asserted and look for a new command. 810 */ 811p_busfree: 812 mvi CLRSINT1,CLRATNO 813 clr LASTPHASE 814 815/* 816 * if this is an immediate command, perform a psuedo command complete to 817 * notify the driver. 818 */ 819 test SCB_CMDLEN,0xff jz status_ok 820 jmp start 821 822/* 823 * Locking the driver out, build a one-byte message passed in SINDEX 824 * if there is no active message already. SINDEX is returned intact. 825 */ 826mk_mesg: 827 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 828 test MSG_LEN,0xff jz mk_mesg1 /* Should always succeed */ 829 830 /* 831 * Hmmm. For some reason the mesg buffer is in use. 832 * Tell the driver. It should look at SINDEX to find 833 * out what we wanted to use the buffer for and resolve 834 * the conflict. 835 */ 836 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 837 mvi INTSTAT,MSG_BUFFER_BUSY 838 839mk_mesg1: 840 mvi MSG_LEN,1 /* length = 1 */ 841 mov MSG0,SINDEX /* 1-byte message */ 842 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 843 844/* 845 * Functions to read data in Automatic PIO mode. 846 * 847 * According to Adaptec's documentation, an ACK is not sent on input from 848 * the target until SCSIDATL is read from. So we wait until SCSIDATL is 849 * latched (the usual way), then read the data byte directly off the bus 850 * using SCSIBUSL. When we have pulled the ATN line, or we just want to 851 * acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI 852 * spec guarantees that the target will hold the data byte on the bus until 853 * we send our ACK. 854 * 855 * The assumption here is that these are called in a particular sequence, 856 * and that REQ is already set when inb_first is called. inb_{first,next} 857 * use the same calling convention as inb. 858 */ 859 860inb_next: 861 or CLRSINT0, CLRSPIORDY 862 mov NONE,SCSIDATL /*dummy read from latch to ACK*/ 863inb_next_wait: 864 test SSTAT1,PHASEMIS jnz mesgin_phasemis 865 test SSTAT0,SPIORDY jz inb_next_wait /* wait for next byte */ 866inb_first: 867 mov DINDEX,SINDEX 868 mov DINDIR,SCSIBUSL ret /*read byte directly from bus*/ 869inb_last: 870 mov NONE,SCSIDATL ret /*dummy read from latch to ACK*/ 871 872mesgin_phasemis: 873/* 874 * We expected to receive another byte, but the target changed phase 875 */ 876 mvi INTSTAT, MSGIN_PHASEMIS 877 jmp ITloop 878 879/* 880 * DMA data transfer. HADDR and HCNT must be loaded first, and 881 * SINDEX should contain the value to load DFCNTRL with - 0x3d for 882 * host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared 883 * during initialization. 884 */ 885dma: 886 mov DFCNTRL,SINDEX 887dma1: 888 test SSTAT0,DMADONE jnz dma3 889 test SSTAT1,PHASEMIS jz dma1 /* ie. underrun */ 890 891/* 892 * We will be "done" DMAing when the transfer count goes to zero, or 893 * the target changes the phase (in light of this, it makes sense that 894 * the DMA circuitry doesn't ACK when PHASEMIS is active). If we are 895 * doing a SCSI->Host transfer, the data FIFO should be flushed auto- 896 * magically on STCNT=0 or a phase change, so just wait for FIFO empty 897 * status. 898 */ 899dma3: 900 test SINDEX,DIRECTION jnz dma5 901dma4: 902 test DFSTATUS,FIFOEMP jz dma4 903 904/* 905 * Now shut the DMA enables off and make sure that the DMA enables are 906 * actually off first lest we get an ILLSADDR. 907 */ 908dma5: 909 /* disable DMA, but maintain WIDEODD */ 910 and DFCNTRL,WIDEODD 911dma6: 912 test DFCNTRL,0x38 jnz dma6 /* SCSIENACK|SDMAENACK|HDMAENACK */ 913 914 ret 915 916/* 917 * Common SCSI initialization for selection and reselection. Expects 918 * the target SCSI ID to be in the upper four bits of SINDEX, and A's 919 * contents are stomped on return. 920 */ 921initialize_scsiid: 922 and SINDEX,0xf0 /* Get target ID */ 923 and A,0x0f,SCSIID 924 or SINDEX,A 925 mov SCSIID,SINDEX ret 926 927/* 928 * Assert that if we've been reselected, then we've seen an IDENTIFY 929 * message. 930 */ 931assert: 932 test FLAGS,RESELECTED jz return /* reselected? */ 933 test FLAGS,IDENTIFY_SEEN jnz return /* seen IDENTIFY? */ 934 935 mvi INTSTAT,NO_IDENT ret /* no - cause a kernel panic */ 936 937/* 938 * Locate the SCB matching the target ID/channel/lun in SAVED_TCL, and the tag 939 * value in ARG_1. If ARG_1 == SCB_LIST_NULL, we're looking for a non-tagged 940 * SCB. Have the kernel print a warning message if it can't be found, and 941 * generate an ABORT/ABORT_TAG message to the target. SINDEX should be 942 * cleared on call. 943 */ 944findSCB: 945 mov A,SAVED_TCL 946 mov SCBPTR,SINDEX /* switch to next SCB */ 947 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 948 cmp SCB_TCL,A jne findSCB1 /* target ID/channel/lun match? */ 949 test SCB_CONTROL,DISCONNECTED jz findSCB1 /*should be disconnected*/ 950 test SCB_CONTROL,TAG_ENB jnz findTaggedSCB 951 cmp ARG_1,SCB_LIST_NULL je foundSCB 952 jmp findSCB1 953findTaggedSCB: 954 mov A, ARG_1 /* Tag passed in ARG_1 */ 955 cmp SCB_TAG,A jne findSCB1 /* Found it? */ 956foundSCB: 957 test FLAGS,PAGESCBS jz foundSCB_ret 958/* Remove this SCB from the disconnection list */ 959 cmp SCB_NEXT,SCB_LIST_NULL je unlink_prev 960 mov SAVED_LINKPTR, SCB_PREV 961 mov SCBPTR, SCB_NEXT 962 mov SCB_PREV, SAVED_LINKPTR 963 mov SCBPTR, SINDEX 964unlink_prev: 965 cmp SCB_PREV,SCB_LIST_NULL je rHead/* At the head of the list */ 966 mov SAVED_LINKPTR, SCB_NEXT 967 mov SCBPTR, SCB_PREV 968 mov SCB_NEXT, SAVED_LINKPTR 969 mov SCBPTR, SINDEX 970 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 971rHead: 972 mov DISCONNECTED_SCBH,SCB_NEXT 973foundSCB_ret: 974 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 975 976findSCB1: 977 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 978 inc SINDEX 979 mov A,SCBCOUNT 980 cmp SINDEX,A jne findSCB 981 982 mvi INTSTAT,NO_MATCH /* not found - signal kernel */ 983 cmp RETURN_1,SCB_PAGEDIN je return 984 or SCSISIGO,ATNO /* assert ATNO */ 985 cmp ARG_1,SCB_LIST_NULL jne find_abort_tag 986 mvi MSG_ABORT call mk_mesg 987 jmp ITloop 988find_abort_tag: 989 mvi MSG_ABORT_TAG call mk_mesg 990 jmp ITloop 991 992/* 993 * Make a working copy of the scatter-gather parameters from the SCB. 994 */ 995sg_scb2ram: 996 mov HADDR0, SCB_DATAPTR0 997 mov HADDR1, SCB_DATAPTR1 998 mov HADDR2, SCB_DATAPTR2 999 mov HADDR3, SCB_DATAPTR3 1000 mov HCNT0, SCB_DATACNT0 1001 mov HCNT1, SCB_DATACNT1 1002 mov HCNT2, SCB_DATACNT2 1003 1004 mov STCNT0, HCNT0 1005 mov STCNT1, HCNT1 1006 mov STCNT2, HCNT2 1007 1008 mov SG_COUNT,SCB_SGCOUNT 1009 1010 mov SG_NEXT0, SCB_SGPTR0 1011 mov SG_NEXT1, SCB_SGPTR1 1012 mov SG_NEXT2, SCB_SGPTR2 1013 mov SG_NEXT3, SCB_SGPTR3 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 mov SCB_SGPTR0,SG_NEXT0 1026 mov SCB_SGPTR1,SG_NEXT1 1027 mov SCB_SGPTR2,SG_NEXT2 1028 mov SCB_SGPTR3,SG_NEXT3 1029 1030 mov SCB_DATAPTR0,SHADDR0 1031 mov SCB_DATAPTR1,SHADDR1 1032 mov SCB_DATAPTR2,SHADDR2 1033 mov SCB_DATAPTR3,SHADDR3 1034 1035/* 1036 * Use the residual number since STCNT is corrupted by any message transfer 1037 */ 1038 mov SCB_DATACNT0,SCB_RESID_DCNT0 1039 mov SCB_DATACNT1,SCB_RESID_DCNT1 1040 mov SCB_DATACNT2,SCB_RESID_DCNT2 ret 1041 1042/* 1043 * Add the array base TARG_SCRATCH to the target offset (the target address 1044 * is in SCSIID), and return the result in SINDEX. The accumulator 1045 * contains the 3->8 decoding of the target ID on return. 1046 */ 1047ndx_dtr: 1048 shr A,SCSIID,4 1049 test SBLKCTL,SELBUSB jz ndx_dtr_2 1050 or A,0x08 /* Channel B entries add 8 */ 1051ndx_dtr_2: 1052 add SINDEX,TARG_SCRATCH,A ret 1053 1054/* 1055 * If we need to negotiate transfer parameters, build the WDTR or SDTR message 1056 * starting at the address passed in SINDEX. DINDEX is modified on return. 1057 * The SCSI-II spec requires that Wide negotiation occur first and you can 1058 * only negotiat one or the other at a time otherwise in the event of a message 1059 * reject, you wouldn't be able to tell which message was the culpret. 1060 */ 1061mk_dtr: 1062 test SCB_CONTROL,NEEDWDTR jnz mk_wdtr_16bit 1063 mvi ARG_1, 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 cmp ARG_1, MAXOFFSET je 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 /* Talking to a WIDE device? */ 1082 test SCSIRATE, WIDEXFER jnz wmax_offset 1083 mvi DINDIR, MAX_OFFSET_8BIT 1084 jmp mk_sdtr_done 1085 1086wmax_offset: 1087 mvi DINDIR, MAX_OFFSET_16BIT 1088 jmp mk_sdtr_done 1089 1090mk_wdtr_16bit: 1091 mvi ARG_1,BUS_16_BIT 1092mk_wdtr: 1093 mvi DINDIR,1 /* extended message */ 1094 mvi DINDIR,2 /* extended message length = 2 */ 1095 mvi DINDIR,3 /* WDTR code */ 1096 mov DINDIR,ARG_1 /* bus width */ 1097 1098 add MSG_LEN,COMP_MSG0,DINDEX ret /* update message length */ 1099 1100sdtr_to_rate: 1101 call ndx_dtr /* index scratch space for target */ 1102 shr A,SINDIR,0x4 1103 dec SINDEX /* Preserve SINDEX */ 1104 and A,0x7 1105 clr RETURN_1 1106sdtr_to_rate_loop: 1107 test A,0x0f jz sdtr_to_rate_done 1108 add RETURN_1,0x19 1109 dec A 1110 jmp sdtr_to_rate_loop 1111sdtr_to_rate_done: 1112 shr RETURN_1,0x2 1113 add RETURN_1,0x19 1114 test SXFRCTL0,ULTRAEN jz return 1115 shr RETURN_1,0x1 1116return: 1117 ret 1118