aic7xxx.seq revision 15951
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 1.36 1996/05/23 15:01:47 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. 258 */ 259 mov FUNCTION1,SCSIID 260 mov A,FUNCTION1 261 and SINDEX,0xdf,SXFRCTL0 /* default to Ultra disabled */ 262 test SCSIID, 0x80 jnz ultra_b /* Target ID > 7 */ 263 test SBLKCTL, SELBUSB jnz ultra_b /* Second channel device */ 264 test ULTRA_ENB,A jz set_sxfrctl0 265 or SINDEX, ULTRAEN jmp set_sxfrctl0 266ultra_b: 267 test ULTRA_ENB_B,A jz set_sxfrctl0 268 or SINDEX, ULTRAEN 269 270set_sxfrctl0: 271 mov SXFRCTL0,SINDEX 272 273 mvi SCSISEQ,ENAUTOATNP /* 274 * ATN on parity errors 275 * for "in" phases 276 */ 277 mvi CLRSINT1,CLRBUSFREE 278 mvi CLRSINT0,0x60 /* CLRSELDI|CLRSELDO */ 279/* 280 * Main loop for information transfer phases. If BSY is false, then 281 * we have a bus free condition, expected or not. Otherwise, wait 282 * for the target to assert REQ before checking MSG, C/D and I/O 283 * for the bus phase. 284 * 285 */ 286ITloop: 287 test SSTAT1,BUSFREE jnz p_busfree 288 test SSTAT1,REQINIT jz ITloop 289 290 and A,PHASE_MASK,SCSISIGI 291 mov LASTPHASE,A 292 mov SCSISIGO,A 293 294 cmp ALLZEROS,A je p_dataout 295 cmp A,P_DATAIN je p_datain 296 cmp A,P_COMMAND je p_command 297 cmp A,P_MESGOUT je p_mesgout 298 cmp A,P_STATUS je p_status 299 cmp A,P_MESGIN je p_mesgin 300 301 mvi INTSTAT,BAD_PHASE /* unknown phase - signal driver */ 302 jmp ITloop /* Try reading the bus again. */ 303 304p_dataout: 305 mvi DMAPARAMS,0x7d /* 306 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 307 * DIRECTION|FIFORESET 308 */ 309 jmp data_phase_init 310 311/* 312 * If we re-enter the data phase after going through another phase, the 313 * STCNT may have been cleared, so restore it from the residual field. 314 */ 315data_phase_reinit: 316 mov STCNT0,SCB_RESID_DCNT0 317 mov STCNT1,SCB_RESID_DCNT1 318 mov STCNT2,SCB_RESID_DCNT2 319 jmp data_phase_loop 320 321p_datain: 322 mvi DMAPARAMS,0x79 /* 323 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 324 * !DIRECTION|FIFORESET 325 */ 326data_phase_init: 327 call assert 328 329 test FLAGS, DPHASE jnz data_phase_reinit 330 call sg_scb2ram 331 or FLAGS, DPHASE /* We have seen a data phase */ 332 333data_phase_loop: 334/* If we are the last SG block, don't set wideodd. */ 335 cmp SG_COUNT,0x01 jne data_phase_wideodd 336 and DMAPARAMS, 0xbf /* Turn off WIDEODD */ 337data_phase_wideodd: 338 mov DMAPARAMS call dma 339 340/* Exit if we had an underrun */ 341 test SSTAT0,SDONE jz data_phase_finish /* underrun STCNT != 0 */ 342 343/* 344 * Advance the scatter-gather pointers if needed 345 */ 346sg_advance: 347 dec SG_COUNT /* one less segment to go */ 348 349 test SG_COUNT, 0xff jz data_phase_finish /* Are we done? */ 350 351 clr A /* add sizeof(struct scatter) */ 352 add SG_NEXT0,SG_SIZEOF,SG_NEXT0 353 adc SG_NEXT1,A,SG_NEXT1 354 355/* 356 * Load a struct scatter and set up the data address and length. 357 * If the working value of the SG count is nonzero, then 358 * we need to load a new set of values. 359 * 360 * This, like all DMA's, assumes little-endian host data storage. 361 */ 362sg_load: 363 clr HCNT2 364 clr HCNT1 365 mvi HCNT0,SG_SIZEOF 366 367 mov HADDR0,SG_NEXT0 368 mov HADDR1,SG_NEXT1 369 mov HADDR2,SG_NEXT2 370 mov HADDR3,SG_NEXT3 371 372 or DFCNTRL,0xd /* HDMAEN|DIRECTION|FIFORESET */ 373 374/* 375 * Wait for DMA from host memory to data FIFO to complete, then disable 376 * DMA and wait for it to acknowledge that it's off. 377 */ 378dma_finish: 379 test DFSTATUS,HDONE jz dma_finish 380 /* Turn off DMA preserving WIDEODD */ 381 and DFCNTRL,WIDEODD 382dma_finish2: 383 test DFCNTRL,HDMAENACK jnz dma_finish2 384 385/* 386 * Copy data from FIFO into SCB data pointer and data count. This assumes 387 * that the struct scatterlist has this structure (this and sizeof(struct 388 * scatterlist) == 12 are asserted in aic7xxx.c for the Linux driver): 389 * 390 * struct scatterlist { 391 * char *address; four bytes, little-endian order 392 * ... four bytes, ignored 393 * unsigned short length; two bytes, little-endian order 394 * } 395 * 396 * 397 * In FreeBSD, the scatter list entry is only 8 bytes. 398 * 399 * struct ahc_dma_seg { 400 * physaddr addr; four bytes, little-endian order 401 * long len; four bytes, little endian order 402 * }; 403 */ 404 405 mov HADDR0,DFDAT 406 mov HADDR1,DFDAT 407 mov HADDR2,DFDAT 408 mov HADDR3,DFDAT 409/* 410 * For Linux, we must throw away four bytes since there is a 32bit gap 411 * in the middle of a struct scatterlist. 412 */ 413#ifdef __linux__ 414 mov NONE,DFDAT 415 mov NONE,DFDAT 416 mov NONE,DFDAT 417 mov NONE,DFDAT 418#endif 419 mov HCNT0,DFDAT 420 mov HCNT1,DFDAT 421 mov HCNT2,DFDAT 422 423/* Load STCNT as well. It is a mirror of HCNT */ 424 mov STCNT0,HCNT0 425 mov STCNT1,HCNT1 426 mov STCNT2,HCNT2 427 test SSTAT1,PHASEMIS jz data_phase_loop 428 429data_phase_finish: 430/* 431 * After a DMA finishes, save the SG and STCNT residuals back into the SCB 432 * We use STCNT instead of HCNT, since it's a reflection of how many bytes 433 * were transferred on the SCSI (as opposed to the host) bus. 434 */ 435 mov SCB_RESID_DCNT0,STCNT0 436 mov SCB_RESID_DCNT1,STCNT1 437 mov SCB_RESID_DCNT2,STCNT2 438 mov SCB_RESID_SGCNT, SG_COUNT 439 jmp ITloop 440 441/* 442 * Command phase. Set up the DMA registers and let 'er rip. 443 */ 444p_command: 445 call assert 446 447/* 448 * Load HADDR and HCNT. 449 */ 450 mov HADDR0, SCB_CMDPTR0 451 mov HADDR1, SCB_CMDPTR1 452 mov HADDR2, SCB_CMDPTR2 453 mov HADDR3, SCB_CMDPTR3 454 mov HCNT0, SCB_CMDLEN 455 clr HCNT1 456 clr HCNT2 457 458 mov STCNT0, HCNT0 459 mov STCNT1, HCNT1 460 mov STCNT2, HCNT2 461 462 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 463 # DIRECTION|FIFORESET 464 jmp ITloop 465 466/* 467 * Status phase. Wait for the data byte to appear, then read it 468 * and store it into the SCB. 469 */ 470p_status: 471 mvi SCB_TARGET_STATUS call inb_first 472 jmp mesgin_done 473 474/* 475 * Message out phase. If there is not an active message, but the target 476 * took us into this phase anyway, build a no-op message and send it. 477 */ 478p_mesgout: 479 test MSG_LEN, 0xff jnz p_mesgout_start 480 mvi MSG_NOP call mk_mesg /* build NOP message */ 481 482p_mesgout_start: 483/* 484 * Set up automatic PIO transfer from MSG0. Bit 3 in 485 * SXFRCTL0 (SPIOEN) is already on. 486 */ 487 mvi SINDEX,MSG0 488 mov DINDEX,MSG_LEN 489 490/* 491 * When target asks for a byte, drop ATN if it's the last one in 492 * the message. Otherwise, keep going until the message is exhausted. 493 * 494 * Keep an eye out for a phase change, in case the target issues 495 * a MESSAGE REJECT. 496 */ 497p_mesgout_loop: 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 test SSTAT1,PHASEMIS jnz p_mesgout_phasemis 503 dec DINDEX 504 or CLRSINT0, CLRSPIORDY 505 mov SCSIDATL,SINDIR 506 507p_mesgout4: 508 test DINDEX,0xff jnz p_mesgout_loop 509 510/* 511 * If the next bus phase after ATN drops is a message out, it means 512 * that the target is requesting that the last message(s) be resent. 513 */ 514p_mesgout_snoop: 515 test SSTAT1,BUSFREE jnz p_mesgout_done 516 test SSTAT1,REQINIT jz p_mesgout_snoop 517 518 test SSTAT1,PHASEMIS jnz p_mesgout_done 519 520 or SCSISIGO,ATNO /* turn on ATNO */ 521 522 jmp ITloop 523 524p_mesgout_phasemis: 525 mvi CLRSINT1,CLRATNO /* Be sure to turn ATNO off */ 526p_mesgout_done: 527 clr MSG_LEN /* no active msg */ 528 jmp ITloop 529 530/* 531 * Message in phase. Bytes are read using Automatic PIO mode. 532 */ 533p_mesgin: 534 mvi A call inb_first /* read the 1st message byte */ 535 mov REJBYTE,A /* save it for the driver */ 536 537 test A,MSG_IDENTIFY jnz mesgin_identify 538 cmp A,MSG_DISCONNECT je mesgin_disconnect 539 cmp A,MSG_SDPTRS je mesgin_sdptrs 540 cmp ALLZEROS,A je mesgin_complete 541 cmp A,MSG_RDPTRS je mesgin_rdptrs 542 cmp A,MSG_EXTENDED je mesgin_extended 543 cmp A,MSG_REJECT je mesgin_reject 544 545rej_mesgin: 546/* 547 * We have no idea what this message in is, and there's no way 548 * to pass it up to the kernel, so we issue a message reject and 549 * hope for the best. Since we're now using manual PIO mode to 550 * read in the message, there should no longer be a race condition 551 * present when we assert ATN. In any case, rejection should be a 552 * rare occurrence - signal the driver when it happens. 553 */ 554 or SCSISIGO,ATNO /* turn on ATNO */ 555 mvi INTSTAT,SEND_REJECT /* let driver know */ 556 557 mvi MSG_REJECT call mk_mesg 558 559mesgin_done: 560 call inb_last /*ack & turn auto PIO back on*/ 561 jmp ITloop 562 563 564mesgin_complete: 565/* 566 * We got a "command complete" message, so put the SCB_TAG into QUEUEOUT, 567 * and trigger a completion interrupt. Check status for non zero return 568 * and interrupt driver if needed. This allows the driver to interpret 569 * errors only when they occur instead of always uploading the scb. If 570 * the status is SCSI_CHECK, the driver will download a new scb requesting 571 * sense to replace the old one, modify the "waiting for selection" SCB list 572 * and set RETURN_1 to SEND_SENSE. If RETURN_1 is set to SEND_SENSE the 573 * sequencer imediately jumps to main loop where it will run down the waiting 574 * SCB list and process the sense request. If the kernel driver does not 575 * wish to request sense, it need only clear RETURN_1, and the command is 576 * allowed to complete. We don't bother to post to the QOUTFIFO in the 577 * error case since it would require extra work in the kernel driver to 578 * ensure that the entry was removed before the command complete code tried 579 * processing it. 580 * 581 * First check for residuals 582 */ 583 test SCB_RESID_SGCNT,0xff jz check_status 584/* 585 * If we have a residual count, interrupt and tell the host. Other 586 * alternatives are to pause the sequencer on all command completes (yuck), 587 * dma the resid directly to the host (slick, we may have space to do it now) 588 * or have the sequencer pause itself when it encounters a non-zero resid 589 * (unecessary pause just to flag the command -yuck-, but takes one instruction 590 * and since it shouldn't happen that often is good enough for our purposes). 591 */ 592resid: 593 mvi INTSTAT,RESIDUAL 594 595check_status: 596 test SCB_TARGET_STATUS,0xff jz status_ok /* Good Status? */ 597 mvi INTSTAT,BAD_STATUS /* let driver know */ 598 cmp RETURN_1, SEND_SENSE jne status_ok 599 jmp mesgin_done 600 601status_ok: 602/* First, mark this target as free. */ 603 test SCB_CONTROL,TAG_ENB jnz test_immediate /* 604 * Tagged commands 605 * don't busy the 606 * target. 607 */ 608 mov FUNCTION1,SCB_TCL 609 mov A,FUNCTION1 610 test SCB_TCL,0x88 jz clear_a 611 xor ACTIVE_B,A 612 jmp test_immediate 613 614clear_a: 615 xor ACTIVE_A,A 616 617test_immediate: 618 test SCB_CMDLEN,0xff jnz complete /* Immediate message complete */ 619/* 620 * Pause the sequencer until the driver gets around to handling the command 621 * complete. This is so that any action that might require carefull timing 622 * with the completion of this command can occur. 623 */ 624 mvi INTSTAT,IMMEDDONE 625 jmp start 626complete: 627 mov QOUTFIFO,SCB_TAG 628 mvi INTSTAT,CMDCMPLT 629 jmp mesgin_done 630 631 632/* 633 * Is it an extended message? We only support the synchronous and wide data 634 * transfer request messages, which will probably be in response to 635 * WDTR or SDTR message outs from us. If it's not SDTR or WDTR, reject it - 636 * apparently this can be done after any message in byte, according 637 * to the SCSI-2 spec. 638 */ 639mesgin_extended: 640 mvi ARG_1 call inb_next /* extended message length */ 641 mvi REJBYTE_EXT call inb_next /* extended message code */ 642 643 cmp REJBYTE_EXT,MSG_SDTR je p_mesginSDTR 644 cmp REJBYTE_EXT,MSG_WDTR je p_mesginWDTR 645 jmp rej_mesgin 646 647p_mesginWDTR: 648 cmp ARG_1,2 jne rej_mesgin /* extended mesg length=2 */ 649 mvi ARG_1 call inb_next /* Width of bus */ 650 mvi INTSTAT,WDTR_MSG /* let driver know */ 651 test RETURN_1,0xff jz mesgin_done /* Do we need to send WDTR? */ 652 cmp RETURN_1,SEND_REJ je rej_mesgin /* 653 * Bus width was too large 654 * Reject it. 655 */ 656 657/* We didn't initiate the wide negotiation, so we must respond to the request */ 658 and RETURN_1,0x7f /* Clear the SEND_WDTR Flag */ 659 mvi DINDEX,MSG0 660 mvi MSG0 call mk_wdtr /* build WDTR message */ 661 or SCSISIGO,ATNO /* turn on ATNO */ 662 jmp mesgin_done 663 664p_mesginSDTR: 665 cmp ARG_1,3 jne rej_mesgin /* extended mesg length=3 */ 666 mvi ARG_1 call inb_next /* xfer period */ 667 mvi A call inb_next /* REQ/ACK offset */ 668 mvi INTSTAT,SDTR_MSG /* call driver to convert */ 669 670 test RETURN_1,0xff jz mesgin_done /* Do we need to mk_sdtr/rej */ 671 cmp RETURN_1,SEND_REJ je rej_mesgin /* 672 * Requested SDTR too small 673 * Reject it. 674 */ 675 clr ARG_1 /* Use the scratch ram rate */ 676 mvi DINDEX, MSG0 677 mvi MSG0 call mk_sdtr 678 or SCSISIGO,ATNO /* turn on ATNO */ 679 jmp mesgin_done 680 681/* 682 * Is it a disconnect message? Set a flag in the SCB to remind us 683 * and await the bus going free. 684 */ 685mesgin_disconnect: 686 or SCB_CONTROL,DISCONNECTED 687 test FLAGS, PAGESCBS jz mesgin_done 688/* 689 * Link this SCB into the DISCONNECTED list. This list holds the 690 * candidates for paging out an SCB if one is needed for a new command. 691 * Modifying the disconnected list is a critical(pause dissabled) section. 692 */ 693 mvi SCB_PREV, SCB_LIST_NULL 694 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 695 mov SCB_NEXT, DISCONNECTED_SCBH 696 mov DISCONNECTED_SCBH, SCBPTR 697 cmp SCB_NEXT,SCB_LIST_NULL je linkdone 698 mov SCBPTR,SCB_NEXT 699 mov SCB_PREV,DISCONNECTED_SCBH 700 mov SCBPTR,DISCONNECTED_SCBH 701linkdone: 702 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 703 jmp mesgin_done 704 705/* 706 * Save data pointers message? Copy working values into the SCB, 707 * usually in preparation for a disconnect. 708 */ 709mesgin_sdptrs: 710 call sg_ram2scb 711 jmp mesgin_done 712 713/* 714 * Restore pointers message? Data pointers are recopied from the 715 * SCB anytime we enter a data phase for the first time, so all 716 * we need to do is clear the DPHASE flag and let the data phase 717 * code do the rest. 718 */ 719mesgin_rdptrs: 720 and FLAGS,0xef /* 721 * !DPHASE we'll reload them 722 * the next time through 723 */ 724 jmp mesgin_done 725 726/* 727 * Identify message? For a reconnecting target, this tells us the lun 728 * that the reconnection is for - find the correct SCB and switch to it, 729 * clearing the "disconnected" bit so we don't "find" it by accident later. 730 */ 731mesgin_identify: 732 test A,0x78 jnz rej_mesgin /*!DiscPriv|!LUNTAR|!Reserved*/ 733 734 and A,0x07 /* lun in lower three bits */ 735 or SAVED_TCL,A,SELID 736 and SAVED_TCL,0xf7 737 and A,SELBUSB,SBLKCTL /* B Channel?? */ 738 or SAVED_TCL,A 739 call inb_last /* ACK */ 740 741/* 742 * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message. 743 * If we get one, we use the tag returned to switch to find the proper 744 * SCB. With SCB paging, this requires using findSCB for both tagged 745 * and non-tagged transactions since the SCB may exist in any slot. 746 * If we're not using SCB paging, we can use the tag as the direct 747 * index to the SCB. 748 */ 749 mvi ARG_1,SCB_LIST_NULL /* Default to no-tag */ 750snoop_tag_loop: 751 test SSTAT1,BUSFREE jnz use_findSCB 752 test SSTAT1,REQINIT jz snoop_tag_loop 753 test SSTAT1,PHASEMIS jnz use_findSCB 754 mvi A call inb_first 755 cmp A,MSG_SIMPLE_TAG jne use_findSCB 756get_tag: 757 mvi ARG_1 call inb_next /* tag value */ 758/* 759 * See if the tag is in range. The tag is < SCBCOUNT if we add 760 * the complement of SCBCOUNT to the incomming tag and there is 761 * no carry. 762 */ 763 mov A,COMP_SCBCOUNT 764 add SINDEX,A,ARG_1 765 jc abort_tag 766 767/* 768 * Ensure that the SCB the tag points to is for an SCB transaction 769 * to the reconnecting target. 770 */ 771 test FLAGS, PAGESCBS jz index_by_tag 772 call inb_last /* Ack Tag */ 773use_findSCB: 774 mov ALLZEROS call findSCB /* Have to search */ 775setup_SCB: 776 and SCB_CONTROL,0xfb /* clear disconnect bit in SCB */ 777 or FLAGS,IDENTIFY_SEEN /* make note of IDENTIFY */ 778 jmp ITloop 779index_by_tag: 780 mov SCBPTR,ARG_1 781 mov A,SAVED_TCL 782 cmp SCB_TCL,A jne abort_tag 783 test SCB_CONTROL,TAG_ENB jz abort_tag 784 call inb_last /* Ack Successful tag */ 785 jmp setup_SCB 786 787abort_tag: 788 or SCSISIGO,ATNO /* turn on ATNO */ 789 mvi INTSTAT,ABORT_TAG /* let driver know */ 790 mvi MSG_ABORT_TAG call mk_mesg /* ABORT TAG message */ 791 jmp mesgin_done 792 793/* 794 * Message reject? Let the kernel driver handle this. If we have an 795 * outstanding WDTR or SDTR negotiation, assume that it's a response from 796 * the target selecting 8bit or asynchronous transfer, otherwise just ignore 797 * it since we have no clue what it pertains to. 798 */ 799mesgin_reject: 800 mvi INTSTAT, REJECT_MSG 801 jmp mesgin_done 802 803/* 804 * [ ADD MORE MESSAGE HANDLING HERE ] 805 */ 806 807/* 808 * Bus free phase. It might be useful to interrupt the device 809 * driver if we aren't expecting this. For now, make sure that 810 * ATN isn't being asserted and look for a new command. 811 */ 812p_busfree: 813 mvi CLRSINT1,CLRATNO 814 clr LASTPHASE 815 816/* 817 * if this is an immediate command, perform a psuedo command complete to 818 * notify the driver. 819 */ 820 test SCB_CMDLEN,0xff jz status_ok 821 jmp start 822 823/* 824 * Locking the driver out, build a one-byte message passed in SINDEX 825 * if there is no active message already. SINDEX is returned intact. 826 */ 827mk_mesg: 828 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 829 test MSG_LEN,0xff jz mk_mesg1 /* Should always succeed */ 830 831 /* 832 * Hmmm. For some reason the mesg buffer is in use. 833 * Tell the driver. It should look at SINDEX to find 834 * out what we wanted to use the buffer for and resolve 835 * the conflict. 836 */ 837 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 838 mvi INTSTAT,MSG_BUFFER_BUSY 839 840mk_mesg1: 841 mvi MSG_LEN,1 /* length = 1 */ 842 mov MSG0,SINDEX /* 1-byte message */ 843 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 844 845/* 846 * Functions to read data in Automatic PIO mode. 847 * 848 * According to Adaptec's documentation, an ACK is not sent on input from 849 * the target until SCSIDATL is read from. So we wait until SCSIDATL is 850 * latched (the usual way), then read the data byte directly off the bus 851 * using SCSIBUSL. When we have pulled the ATN line, or we just want to 852 * acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI 853 * spec guarantees that the target will hold the data byte on the bus until 854 * we send our ACK. 855 * 856 * The assumption here is that these are called in a particular sequence, 857 * and that REQ is already set when inb_first is called. inb_{first,next} 858 * use the same calling convention as inb. 859 */ 860 861inb_next: 862 or CLRSINT0, CLRSPIORDY 863 mov NONE,SCSIDATL /*dummy read from latch to ACK*/ 864inb_next_wait: 865 test SSTAT0,SPIORDY jz inb_next_wait /* wait for next byte */ 866 test SSTAT1,PHASEMIS jnz mesgin_phasemis 867inb_first: 868 mov DINDEX,SINDEX 869 mov DINDIR,SCSIBUSL ret /*read byte directly from bus*/ 870inb_last: 871 mov NONE,SCSIDATL ret /*dummy read from latch to ACK*/ 872 873mesgin_phasemis: 874/* 875 * We expected to receive another byte, but the target changed phase 876 */ 877 mvi INTSTAT, MSGIN_PHASEMIS 878 jmp ITloop 879 880/* 881 * DMA data transfer. HADDR and HCNT must be loaded first, and 882 * SINDEX should contain the value to load DFCNTRL with - 0x3d for 883 * host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared 884 * during initialization. 885 */ 886dma: 887 mov DFCNTRL,SINDEX 888dma1: 889 test SSTAT0,DMADONE jnz dma3 890 test SSTAT1,PHASEMIS jz dma1 /* ie. underrun */ 891 892/* 893 * We will be "done" DMAing when the transfer count goes to zero, or 894 * the target changes the phase (in light of this, it makes sense that 895 * the DMA circuitry doesn't ACK when PHASEMIS is active). If we are 896 * doing a SCSI->Host transfer, the data FIFO should be flushed auto- 897 * magically on STCNT=0 or a phase change, so just wait for FIFO empty 898 * status. 899 */ 900dma3: 901 test SINDEX,DIRECTION jnz dma5 902dma4: 903 test DFSTATUS,FIFOEMP jz dma4 904 905/* 906 * Now shut the DMA enables off and make sure that the DMA enables are 907 * actually off first lest we get an ILLSADDR. 908 */ 909dma5: 910 /* disable DMA, but maintain WIDEODD */ 911 and DFCNTRL,WIDEODD 912dma6: 913 test DFCNTRL,0x38 jnz dma6 /* SCSIENACK|SDMAENACK|HDMAENACK */ 914 915 ret 916 917/* 918 * Common SCSI initialization for selection and reselection. Expects 919 * the target SCSI ID to be in the upper four bits of SINDEX, and A's 920 * contents are stomped on return. 921 */ 922initialize_scsiid: 923 and SINDEX,0xf0 /* Get target ID */ 924 and A,0x0f,SCSIID 925 or SINDEX,A 926 mov SCSIID,SINDEX ret 927 928/* 929 * Assert that if we've been reselected, then we've seen an IDENTIFY 930 * message. 931 */ 932assert: 933 test FLAGS,RESELECTED jz return /* reselected? */ 934 test FLAGS,IDENTIFY_SEEN jnz return /* seen IDENTIFY? */ 935 936 mvi INTSTAT,NO_IDENT ret /* no - cause a kernel panic */ 937 938/* 939 * Locate the SCB matching the target ID/channel/lun in SAVED_TCL, and the tag 940 * value in ARG_1. If ARG_1 == SCB_LIST_NULL, we're looking for a non-tagged 941 * SCB. Have the kernel print a warning message if it can't be found, and 942 * generate an ABORT/ABORT_TAG message to the target. SINDEX should be 943 * cleared on call. 944 */ 945findSCB: 946 mov A,SAVED_TCL 947 mov SCBPTR,SINDEX /* switch to next SCB */ 948 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 949 cmp SCB_TCL,A jne findSCB1 /* target ID/channel/lun match? */ 950 test SCB_CONTROL,DISCONNECTED jz findSCB1 /*should be disconnected*/ 951 test SCB_CONTROL,TAG_ENB jnz findTaggedSCB 952 cmp ARG_1,SCB_LIST_NULL je foundSCB 953 jmp findSCB1 954findTaggedSCB: 955 mov A, ARG_1 /* Tag passed in ARG_1 */ 956 cmp SCB_TAG,A jne findSCB1 /* Found it? */ 957foundSCB: 958 test FLAGS,PAGESCBS jz foundSCB_ret 959/* Remove this SCB from the disconnection list */ 960 cmp SCB_NEXT,SCB_LIST_NULL je unlink_prev 961 mov SAVED_LINKPTR, SCB_PREV 962 mov SCBPTR, SCB_NEXT 963 mov SCB_PREV, SAVED_LINKPTR 964 mov SCBPTR, SINDEX 965unlink_prev: 966 cmp SCB_PREV,SCB_LIST_NULL je rHead/* At the head of the list */ 967 mov SAVED_LINKPTR, SCB_NEXT 968 mov SCBPTR, SCB_PREV 969 mov SCB_NEXT, SAVED_LINKPTR 970 mov SCBPTR, SINDEX 971 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 972rHead: 973 mov DISCONNECTED_SCBH,SCB_NEXT 974foundSCB_ret: 975 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 976 977findSCB1: 978 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 979 inc SINDEX 980 mov A,SCBCOUNT 981 cmp SINDEX,A jne findSCB 982 983 mvi INTSTAT,NO_MATCH /* not found - signal kernel */ 984 cmp RETURN_1,SCB_PAGEDIN je return 985 or SCSISIGO,ATNO /* assert ATNO */ 986 cmp ARG_1,SCB_LIST_NULL jne find_abort_tag 987 mvi MSG_ABORT call mk_mesg 988 jmp ITloop 989find_abort_tag: 990 mvi MSG_ABORT_TAG call mk_mesg 991 jmp ITloop 992 993/* 994 * Make a working copy of the scatter-gather parameters from the SCB. 995 */ 996sg_scb2ram: 997 mov HADDR0, SCB_DATAPTR0 998 mov HADDR1, SCB_DATAPTR1 999 mov HADDR2, SCB_DATAPTR2 1000 mov HADDR3, SCB_DATAPTR3 1001 mov HCNT0, SCB_DATACNT0 1002 mov HCNT1, SCB_DATACNT1 1003 mov HCNT2, SCB_DATACNT2 1004 1005 mov STCNT0, HCNT0 1006 mov STCNT1, HCNT1 1007 mov STCNT2, HCNT2 1008 1009 mov SG_COUNT,SCB_SGCOUNT 1010 1011 mov SG_NEXT0, SCB_SGPTR0 1012 mov SG_NEXT1, SCB_SGPTR1 1013 mov SG_NEXT2, SCB_SGPTR2 1014 mov SG_NEXT3, SCB_SGPTR3 ret 1015 1016/* 1017 * Copying RAM values back to SCB, for Save Data Pointers message, but 1018 * only if we've actually been into a data phase to change them. This 1019 * protects against bogus data in scratch ram and the residual counts 1020 * since they are only initialized when we go into data_in or data_out. 1021 */ 1022sg_ram2scb: 1023 test FLAGS, DPHASE jz return 1024 mov SCB_SGCOUNT,SG_COUNT 1025 1026 mov SCB_SGPTR0,SG_NEXT0 1027 mov SCB_SGPTR1,SG_NEXT1 1028 mov SCB_SGPTR2,SG_NEXT2 1029 mov SCB_SGPTR3,SG_NEXT3 1030 1031 mov SCB_DATAPTR0,SHADDR0 1032 mov SCB_DATAPTR1,SHADDR1 1033 mov SCB_DATAPTR2,SHADDR2 1034 mov SCB_DATAPTR3,SHADDR3 1035 1036/* 1037 * Use the residual number since STCNT is corrupted by any message transfer 1038 */ 1039 mov SCB_DATACNT0,SCB_RESID_DCNT0 1040 mov SCB_DATACNT1,SCB_RESID_DCNT1 1041 mov SCB_DATACNT2,SCB_RESID_DCNT2 ret 1042 1043/* 1044 * Add the array base TARG_SCRATCH to the target offset (the target address 1045 * is in SCSIID), and return the result in SINDEX. The accumulator 1046 * contains the 3->8 decoding of the target ID on return. 1047 */ 1048ndx_dtr: 1049 shr A,SCSIID,4 1050 test SBLKCTL,SELBUSB jz ndx_dtr_2 1051 or A,0x08 /* Channel B entries add 8 */ 1052ndx_dtr_2: 1053 add SINDEX,TARG_SCRATCH,A ret 1054 1055/* 1056 * If we need to negotiate transfer parameters, build the WDTR or SDTR message 1057 * starting at the address passed in SINDEX. DINDEX is modified on return. 1058 * The SCSI-II spec requires that Wide negotiation occur first and you can 1059 * only negotiat one or the other at a time otherwise in the event of a message 1060 * reject, you wouldn't be able to tell which message was the culpret. 1061 */ 1062mk_dtr: 1063 test SCB_CONTROL,NEEDWDTR jnz mk_wdtr_16bit 1064 mvi ARG_1, MAXOFFSET /* Force an offset of 15 or 8 if WIDE */ 1065 1066mk_sdtr: 1067 mvi DINDIR,1 /* extended message */ 1068 mvi DINDIR,3 /* extended message length = 3 */ 1069 mvi DINDIR,1 /* SDTR code */ 1070 call sdtr_to_rate 1071 mov DINDIR,RETURN_1 /* REQ/ACK transfer period */ 1072 cmp ARG_1, MAXOFFSET je mk_sdtr_max_offset 1073 and DINDIR,0x0f,SINDIR /* Sync Offset */ 1074 1075mk_sdtr_done: 1076 add MSG_LEN,COMP_MSG0,DINDEX ret /* update message length */ 1077 1078mk_sdtr_max_offset: 1079/* 1080 * We're initiating sync negotiation, so request the max offset we can (15 or 8) 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 1101sdtr_to_rate: 1102 call ndx_dtr /* index scratch space for target */ 1103 shr A,SINDIR,0x4 1104 dec SINDEX /* Preserve SINDEX */ 1105 and A,0x7 1106 clr RETURN_1 1107sdtr_to_rate_loop: 1108 test A,0x0f jz sdtr_to_rate_done 1109 add RETURN_1,0x19 1110 dec A 1111 jmp sdtr_to_rate_loop 1112sdtr_to_rate_done: 1113 shr RETURN_1,0x2 1114 add RETURN_1,0x19 1115 test SXFRCTL0,ULTRAEN jz return 1116 shr RETURN_1,0x1 1117return: 1118 ret 1119