aic7xxx.seq revision 20117
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 1.51 1996/11/22 08:25:20 gibbs Exp $" 43 44#if defined(__NetBSD__) 45#include "../../../../dev/ic/aic7xxxreg.h" 46#include "../../../../scsi/scsi_message.h" 47#elif defined(__FreeBSD__) 48#include "../../dev/aic7xxx/aic7xxx_reg.h" 49#include "../../scsi/scsi_message.h" 50#endif 51 52/* 53 * We can't just use ACCUM in the sequencer code because it 54 * must be treated specially by the assembler, and it currently 55 * looks for the symbol 'A'. This is the only register defined in 56 * the assembler's symbol space. 57 */ 58A = ACCUM 59 60/* 61 * A few words on the waiting SCB list: 62 * After starting the selection hardware, we check for reconnecting targets 63 * as well as for our selection to complete just in case the reselection wins 64 * bus arbitration. The problem with this is that we must keep track of the 65 * SCB that we've already pulled from the QINFIFO and started the selection 66 * on just in case the reselection wins so that we can retry the selection at 67 * a later time. This problem cannot be resolved by holding a single entry 68 * in scratch ram since a reconnecting target can request sense and this will 69 * create yet another SCB waiting for selection. The solution used here is to 70 * use byte 27 of the SCB as a psuedo-next pointer and to thread a list 71 * of SCBs that are awaiting selection. Since 0-0xfe are valid SCB indexes, 72 * SCB_LIST_NULL is 0xff which is out of range. An entry is also added to 73 * this list everytime a request sense occurs or after completing a non-tagged 74 * command for which a second SCB has been queued. The sequencer will 75 * automatically consume the entries. 76 */ 77 78/* 79 * We assume that the kernel driver may reset us at any time, even in the 80 * middle of a DMA, so clear DFCNTRL too. 81 */ 82reset: 83 clr DFCNTRL 84 clr SCSISIGO /* De-assert BSY */ 85 86p_busfree: 87 mvi SCSISEQ,ENRSELI /* Always allow reselection */ 88 clr SCSIRATE /* 89 * We don't know the target we will 90 * connect to, so default to narrow 91 * transfers to avoid parity problems. 92 */ 93 mvi LASTPHASE, P_BUSFREE 94 and FLAGS,0x07 /* clear target specific flags */ 95poll_for_work: 96 /* 97 * Are we a twin channel device? 98 * For fairness, we check the other bus first, 99 * since we just finished a transaction on the 100 * current channel. 101 */ 102 test FLAGS,TWIN_BUS jz start2 103 xor SBLKCTL,SELBUSB /* Toggle to the other bus */ 104 test SSTAT0,SELDI jnz reselect 105 xor SBLKCTL,SELBUSB /* Toggle to the original bus */ 106start2: 107 test SSTAT0,SELDI jnz reselect 108 cmp WAITING_SCBH,SCB_LIST_NULL je test_queue 109start_waiting: 110 /* 111 * Pull the first entry off of the waiting SCB list 112 * We don't have to "test_busy" because only transactions that 113 * have passed that test can be in the WAITING_SCB list. 114 */ 115 mov SCBPTR,WAITING_SCBH 116 jmp start_scb2 117test_queue: 118 /* Has the driver posted any work for us? */ 119 mov A, QCNTMASK 120 test QINCNT,A jz poll_for_work 121 122/* 123 * We have at least one queued SCB now and we don't have any 124 * SCBs in the list of SCBs awaiting selection. If we have 125 * any SCBs availible for use, pull the tag from the QINFIFO 126 * and get to work on it. 127 */ 128 test FLAGS, PAGESCBS jz dequeue_scb 129 mov ALLZEROS call get_free_or_disc_scb 130 cmp SINDEX, SCB_LIST_NULL je poll_for_work 131dequeue_scb: 132 mov CUR_SCBID,QINFIFO 133 test FLAGS, PAGESCBS jnz dma_queued_scb 134 /* In the non-paging case, the SCBID == hardware SCB index */ 135 mov SCBPTR, CUR_SCBID 136dma_queued_scb: 137/* 138 * DMA the SCB from host ram into the current SCB location. 139 */ 140 mvi DMAPARAMS, 0xd /* HDMAEN|DIRECTION|FIFORESET */ 141 mov CUR_SCBID call dma_scb 142 143/* 144 * See if there is not already an active SCB for this target. This code 145 * locks out on a per target basis instead of target/lun. Although this 146 * is not ideal for devices that have multiple luns active at the same 147 * time, it is faster than looping through all SCB's looking for active 148 * commands. We also don't have enough spare SCB space for us to store the 149 * SCBID of the currently busy transaction for each target/lun making it 150 * impossible to link up the SCBs. 151 */ 152test_busy: 153 test SCB_CONTROL, TAG_ENB jnz start_scb 154 mov SAVED_SCBPTR, SCBPTR 155 mov SCB_TCL call index_untagged_scb 156 mov ARG_1, SINDIR /* 157 * ARG_1 should 158 * now have the SCB ID of 159 * any active, non-tagged, 160 * command for this target. 161 */ 162 cmp ARG_1, SCB_LIST_NULL je make_busy 163 test FLAGS, PAGESCBS jz simple_busy_link 164 /* 165 * Put this SCB back onto the free list. It 166 * may be necessary to satisfy the search for 167 * the active SCB. 168 */ 169 mov SCBPTR, SAVED_SCBPTR 170 call add_scb_to_free_list 171 /* Find the active SCB */ 172 mov ALLZEROS call findSCB 173 /* 174 * If we couldn't find it, tell the kernel. This should 175 * only happen if the parent SCB was aborted and this 176 * one was already here at the time of the abort. 177 */ 178 cmp SINDEX, SCB_LIST_NULL jne paged_busy_link 179 mvi INTSTAT, NO_MATCH_BUSY 180paged_busy_link: 181 /* Link us in */ 182 mov SCB_LINKED_NEXT, CUR_SCBID 183 /* Put it back on the disconnected list */ 184 call add_scb_to_disc_list 185 jmp poll_for_work 186simple_busy_link: 187 mov SCBPTR, ARG_1 188 mov SCB_LINKED_NEXT, CUR_SCBID 189 jmp poll_for_work 190make_busy: 191 mov DINDIR, CUR_SCBID 192 mov SCBPTR, SAVED_SCBPTR 193 194start_scb: 195 /* 196 * Place us on the waiting list in case our selection 197 * doesn't win during bus arbitration. 198 */ 199 mov SCB_NEXT,WAITING_SCBH 200 mov WAITING_SCBH, SCBPTR 201start_scb2: 202 and SINDEX,0xf7,SBLKCTL /* Clear the channel select bit */ 203 and A,0x08,SCB_TCL /* Get new channel bit */ 204 or SINDEX,A 205 mov SBLKCTL,SINDEX /* select channel */ 206 mov SCB_TCL call initialize_scsiid 207 208/* 209 * Enable selection phase as an initiator, and do automatic ATN 210 * after the selection. We do this now so that we can overlap the 211 * rest of our work to set up this target with the arbitration and 212 * selection bus phases. 213 */ 214start_selection: 215 mvi SCSISEQ,0x58 /* ENSELO|ENAUTOATNO|ENRSELI */ 216 217/* 218 * As soon as we get a successful selection, the target should go 219 * into the message out phase since we have ATN asserted. Prepare 220 * the message to send. 221 * 222 * Messages are stored in scratch RAM starting with a length byte 223 * followed by the message itself. 224 */ 225 226mk_identify: 227 and MSG0,0x7,SCB_TCL /* lun */ 228 and A,DISCENB,SCB_CONTROL /* mask off disconnect privledge */ 229 or MSG0,A /* or in disconnect privledge */ 230 or MSG0,MSG_IDENTIFYFLAG 231 mvi MSG_LEN, 1 232 233/* 234 * Send a tag message if TAG_ENB is set in the SCB control block. 235 * Use SCB_TAG (the position in the kernel's SCB array) as the tag value. 236 */ 237mk_tag: 238 test SCB_CONTROL,TAG_ENB jz mk_message 239 and MSG1,0x23,SCB_CONTROL 240 mov MSG2,SCB_TAG 241 add MSG_LEN,2 /* update message length */ 242 243/* 244 * Interrupt the driver, and allow it to tweak the message buffer 245 * if it asks. 246 */ 247mk_message: 248 test SCB_CONTROL,MK_MESSAGE jz wait_for_selection 249 250 mvi INTSTAT,AWAITING_MSG 251 252wait_for_selection: 253 test SSTAT0,SELDO jnz select 254 test SSTAT0,SELDI jz wait_for_selection 255 256/* 257 * Reselection has been initiated by a target. Make a note that we've been 258 * reselected, but haven't seen an IDENTIFY message from the target yet. 259 */ 260reselect: 261 clr MSG_LEN /* Don't have anything in the mesg buffer */ 262 mov SELID call initialize_scsiid 263 or FLAGS,RESELECTED 264 jmp select2 265 266/* 267 * After the selection, remove this SCB from the "waiting SCB" 268 * list. This is achieved by simply moving our "next" pointer into 269 * WAITING_SCBH. Our next pointer will be set to null the next time this 270 * SCB is used, so don't bother with it now. 271 */ 272select: 273 mov WAITING_SCBH,SCB_NEXT 274select2: 275/* 276 * Initialize SCSIRATE with the appropriate value for this target. 277 * The SCSIRATE settings for each target are stored in an array 278 * based at TARG_SCRATCH. 279 */ 280ndx_dtr: 281 shr A,SCSIID,4 282 test SBLKCTL,SELBUSB jz ndx_dtr_2 283 or SAVED_TCL, SELBUSB /* Add the channel bit while we're here */ 284 or A,0x08 /* Channel B entries add 8 */ 285ndx_dtr_2: 286 add SINDEX,TARG_SCRATCH,A 287 mov SCSIRATE,SINDIR 288 289/* 290 * Initialize Ultra mode setting and clear the SCSI channel. 291 */ 292ultra: 293 and DINDEX,0xdf,SXFRCTL0 /* default to Ultra disabled */ 294 /* 295 * Set CLRCHN here before the target has entered a data transfer mode - 296 * with synchronous SCSI, if you do it later, you blow away some 297 * data in the SCSI FIFO that the target has already sent to you. 298 */ 299 or DINDEX, CLRCHN 300 mvi SINDEX, ULTRA_ENB_B 301 test SCSIID, 0x80 jnz ultra_2 /* Target ID > 7 */ 302 test SBLKCTL, SELBUSB jnz ultra_2 /* Second channel device */ 303 dec SINDEX 304ultra_2: 305 mov FUNCTION1,SCSIID 306 mov A,FUNCTION1 307 test SINDIR, A jz set_sxfrctl0 308 or DINDEX, ULTRAEN 309 310set_sxfrctl0: 311 mov SXFRCTL0,DINDEX 312 313 mvi SCSISEQ,ENAUTOATNP /* 314 * ATN on parity errors 315 * for "in" phases 316 */ 317 mvi CLRSINT1,CLRBUSFREE 318 mvi CLRSINT0,0x60 /* CLRSELDI|CLRSELDO */ 319 or SIMODE1, ENBUSFREE /* 320 * We aren't expecting a 321 * bus free, so interrupt 322 * the kernel driver if it 323 * happens. 324 */ 325/* 326 * Main loop for information transfer phases. If BSY is false, then 327 * we have a bus free condition, expected or not. Otherwise, wait 328 * for the target to assert REQ before checking MSG, C/D and I/O 329 * for the bus phase. 330 * 331 */ 332ITloop: 333 test SSTAT1,BUSFREE jnz p_busfree 334 test SSTAT1,REQINIT jz ITloop 335 336 and A,PHASE_MASK,SCSISIGI 337 mov LASTPHASE,A 338 mov SCSISIGO,A 339 340 cmp ALLZEROS,A je p_dataout 341 cmp A,P_DATAIN je p_datain 342 cmp A,P_COMMAND je p_command 343 cmp A,P_MESGOUT je p_mesgout 344 cmp A,P_STATUS je p_status 345 cmp A,P_MESGIN je p_mesgin 346 347 mvi INTSTAT,BAD_PHASE /* unknown phase - signal driver */ 348 jmp ITloop /* Try reading the bus again. */ 349 350p_dataout: 351 mvi DMAPARAMS,0x7d /* 352 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 353 * DIRECTION|FIFORESET 354 */ 355 jmp data_phase_init 356 357/* 358 * If we re-enter the data phase after going through another phase, the 359 * STCNT may have been cleared, so restore it from the residual field. 360 */ 361data_phase_reinit: 362 mvi DINDEX, STCNT0 363 mvi SCB_RESID_DCNT0 call bcopy_3 364 jmp data_phase_loop 365 366p_datain: 367 mvi DMAPARAMS,0x79 /* 368 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 369 * !DIRECTION|FIFORESET 370 */ 371data_phase_init: 372 call assert /* 373 * Ensure entering a data 374 * phase is okay - seen identify, etc. 375 */ 376 377 test FLAGS, DPHASE jnz data_phase_reinit 378 379 /* 380 * Initialize the DMA address and counter from the SCB. 381 * Also set SG_COUNT and SG_NEXT in memory since we cannot 382 * modify the values in the SCB itself until we see a 383 * save data pointers message. 384 */ 385 mvi DINDEX, HADDR0 386 mvi SCB_DATAPTR call bcopy_7 387 388 call set_stcnt_from_hcnt 389 390 mov SG_COUNT,SCB_SGCOUNT 391 392 mvi DINDEX, SG_NEXT 393 mvi SCB_SGPTR call bcopy_4 394 395 /* We have seen a data phase */ 396 or FLAGS, DPHASE 397 398data_phase_loop: 399/* Guard against overruns */ 400 test SG_COUNT, 0xff jnz data_phase_inbounds 401/* 402 * Turn on 'Bit Bucket' mode, set the transfer count to 403 * 16meg and let the target run until it changes phase. 404 * When the transfer completes, notify the host that we 405 * had an overrun. 406 */ 407 or SXFRCTL1,BITBUCKET 408 and DMAPARAMS, 0xf7 /* Turn off HDMAEN */ 409 mvi STCNT0,0xff 410 mvi STCNT1,0xff 411 mvi STCNT2,0xff 412 413data_phase_inbounds: 414/* If we are the last SG block, ensure wideodd is off. */ 415 cmp SG_COUNT,0x01 jne data_phase_wideodd 416 and DMAPARAMS, 0xbf /* Turn off WIDEODD */ 417data_phase_wideodd: 418 mov DMAPARAMS call dma 419 420/* Go tell the host about any overruns */ 421 test SXFRCTL1,BITBUCKET jnz data_phase_overrun 422 423/* Exit if we had an underrun */ 424 test SSTAT0,SDONE jz data_phase_finish /* underrun STCNT != 0 */ 425 426/* 427 * Advance the scatter-gather pointers if needed 428 */ 429sg_advance: 430 dec SG_COUNT /* one less segment to go */ 431 432 test SG_COUNT, 0xff jz data_phase_finish /* Are we done? */ 433 434 clr A /* add sizeof(struct scatter) */ 435 add SG_NEXT0,SG_SIZEOF,SG_NEXT0 436 adc SG_NEXT1,A,SG_NEXT1 437 438/* 439 * Load a struct scatter and set up the data address and length. 440 * If the working value of the SG count is nonzero, then 441 * we need to load a new set of values. 442 * 443 * This, like all DMA's, assumes little-endian host data storage. 444 */ 445sg_load: 446 clr HCNT2 447 clr HCNT1 448 mvi HCNT0,SG_SIZEOF 449 450 mvi DINDEX, HADDR0 451 mvi SG_NEXT0 call bcopy_4 452 453 or DFCNTRL,0xd /* HDMAEN|DIRECTION|FIFORESET */ 454 455 call dma_finish 456 457/* 458 * Copy data from FIFO into SCB data pointer and data count. This assumes 459 * that the SG segments are of the form: 460 * 461 * struct ahc_dma_seg { 462 * u_int32_t addr; four bytes, little-endian order 463 * u_int32_t len; four bytes, little endian order 464 * }; 465 */ 466 mvi HADDR0 call dfdat_in_7 467 468/* Load STCNT as well. It is a mirror of HCNT */ 469 call set_stcnt_from_hcnt 470 test SSTAT1,PHASEMIS jz data_phase_loop 471 472data_phase_finish: 473/* 474 * After a DMA finishes, save the SG and STCNT residuals back into the SCB 475 * We use STCNT instead of HCNT, since it's a reflection of how many bytes 476 * were transferred on the SCSI (as opposed to the host) bus. 477 */ 478 mov SCB_RESID_DCNT0,STCNT0 479 mov SCB_RESID_DCNT1,STCNT1 480 mov SCB_RESID_DCNT2,STCNT2 481 mov SCB_RESID_SGCNT, SG_COUNT 482 jmp ITloop 483 484data_phase_overrun: 485/* 486 * Turn off BITBUCKET mode and notify the host 487 */ 488 and SXFRCTL1,0x7f /* ~BITBUCKET */ 489 mvi INTSTAT,DATA_OVERRUN 490 jmp ITloop 491 492/* 493 * Command phase. Set up the DMA registers and let 'er rip. 494 */ 495p_command: 496 call assert 497 498/* 499 * Load HADDR and HCNT. 500 */ 501 mvi DINDEX, HADDR0 502 mvi SCB_CMDPTR call bcopy_5 503 clr HCNT1 504 clr HCNT2 505 506 call set_stcnt_from_hcnt 507 508 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 509 # DIRECTION|FIFORESET 510 jmp ITloop 511 512/* 513 * Status phase. Wait for the data byte to appear, then read it 514 * and store it into the SCB. 515 */ 516p_status: 517 call assert 518 519 mvi SCB_TARGET_STATUS call inb_first 520 jmp mesgin_done 521 522/* 523 * Message out phase. If there is not an active message, but the target 524 * took us into this phase anyway, build a no-op message and send it. 525 */ 526p_mesgout: 527 test MSG_LEN, 0xff jnz p_mesgout_start 528 mvi MSG_NOOP call mk_mesg /* build NOP message */ 529p_mesgout_start: 530/* 531 * Set up automatic PIO transfer from MSG0. Bit 3 in 532 * SXFRCTL0 (SPIOEN) is already on. 533 */ 534 mvi SINDEX,MSG0 535 mov DINDEX,MSG_LEN 536 537/* 538 * When target asks for a byte, drop ATN if it's the last one in 539 * the message. Otherwise, keep going until the message is exhausted. 540 * 541 * Keep an eye out for a phase change, in case the target issues 542 * a MESSAGE REJECT. 543 */ 544p_mesgout_loop: 545 test SSTAT0,SPIORDY jz p_mesgout_loop 546 test SSTAT1,PHASEMIS jnz p_mesgout_done 547/* 548 * If the next bus phase after ATN drops is a message out, it means 549 * that the target is requesting that the last message(s) be resent. 550 */ 551p_mesgout_testretry: 552 test DINDEX,0xff jnz p_mesgout_dropatn 553 or SCSISIGO,ATNO /* turn on ATN for the retry */ 554 jmp p_mesgout_start 555p_mesgout_dropatn: 556 cmp DINDEX,1 jne p_mesgout_outb /* last byte? */ 557 mvi CLRSINT1,CLRATNO /* drop ATN */ 558p_mesgout_outb: 559 dec DINDEX 560 mvi CLRSINT0, CLRSPIORDY 561 mov SCSIDATL,SINDIR 562 jmp p_mesgout_loop 563 564p_mesgout_done: 565 mvi CLRSINT1,CLRATNO /* Be sure to turn ATNO off */ 566 clr MSG_LEN /* no active msg */ 567 jmp ITloop 568 569/* 570 * Message in phase. Bytes are read using Automatic PIO mode. 571 */ 572p_mesgin: 573 mvi A call inb_first /* read the 1st message byte */ 574 mov REJBYTE,A /* save it for the driver */ 575 576 test A,MSG_IDENTIFYFLAG jnz mesgin_identify 577 cmp A,MSG_DISCONNECT je mesgin_disconnect 578 cmp A,MSG_SAVEDATAPOINTER je mesgin_sdptrs 579 cmp ALLZEROS,A je mesgin_complete 580 cmp A,MSG_RESTOREPOINTERS je mesgin_rdptrs 581 cmp A,MSG_EXTENDED je mesgin_extended 582 cmp A,MSG_MESSAGE_REJECT je mesgin_reject 583 584rej_mesgin: 585/* 586 * We have no idea what this message in is, so we issue a message reject 587 * and hope for the best. In any case, rejection should be a rare 588 * occurrence - signal the driver when it happens. 589 */ 590 mvi INTSTAT,SEND_REJECT /* let driver know */ 591 592 mvi MSG_MESSAGE_REJECT call mk_mesg 593 594mesgin_done: 595 call inb_last /*ack & turn auto PIO back on*/ 596 jmp ITloop 597 598 599mesgin_complete: 600/* 601 * We got a "command complete" message, so put the SCB_TAG into the QOUTFIFO, 602 * and trigger a completion interrupt. Before doing so, check to see if there 603 * is a residual or the status byte is something other than NO_ERROR (0). In 604 * either of these conditions, we upload the SCB back to the host so it can 605 * process this information. In the case of a non zero status byte, we 606 * additionally interrupt the kernel driver synchronously, allowing it to 607 * decide if sense should be retrieved. If the kernel driver wishes to request 608 * sense, it will fill the kernel SCB with a request sense command and set 609 * RETURN_1 to SEND_SENSE. If RETURN_1 is set to SEND_SENSE we redownload 610 * the SCB, and process it as the next command by adding it to the waiting list. 611 * If the kernel driver does not wish to request sense, it need only clear 612 * RETURN_1, and the command is allowed to complete normally. We don't bother 613 * to post to the QOUTFIFO in the error cases since it would require extra 614 * work in the kernel driver to ensure that the entry was removed before the 615 * command complete code tried processing it. 616 */ 617 618/* 619 * We expect to go to bus free after this message. 620 */ 621 and SIMODE1, 0xf7 /* ~ENBUSFREE */ 622/* 623 * First check for residuals 624 */ 625 test SCB_RESID_SGCNT,0xff jnz upload_scb 626 test SCB_TARGET_STATUS,0xff jz status_ok /* Good Status? */ 627upload_scb: 628 mvi DMAPARAMS, 0x9 /* HDMAEN | FIFORESET*/ 629 mov SCB_TAG call dma_scb 630check_status: 631 test SCB_TARGET_STATUS,0xff jz status_ok /* Just a residual? */ 632 mvi INTSTAT,BAD_STATUS /* let driver know */ 633 cmp RETURN_1, SEND_SENSE jne status_ok 634 /* This SCB becomes the next to execute as it will retrieve sense */ 635 mov SCB_LINKED_NEXT, SCB_TAG 636 jmp dma_next_scb 637 638status_ok: 639/* First, mark this target as free. */ 640 test SCB_CONTROL,TAG_ENB jnz complete /* 641 * Tagged commands 642 * don't busy the 643 * target. 644 */ 645 mov SAVED_SCBPTR, SCBPTR 646 mov SAVED_LINKPTR, SCB_LINKED_NEXT 647 mov SCB_TCL call index_untagged_scb 648 mov DINDIR, SAVED_LINKPTR 649 mov SCBPTR, SAVED_SCBPTR 650 651complete: 652 test FLAGS, PAGESCBS jz complete_post 653 mov A, QFULLCNT 654complete_poll: 655 cmp QOUTQCNT, A je complete_poll 656 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 657 inc QOUTQCNT 658complete_post: 659 /* Post the SCB and issue an interrupt */ 660 mov QOUTFIFO,SCB_TAG 661 mvi SEQCTL,0x10 /* FASTMODE */ 662 mvi INTSTAT,CMDCMPLT 663 664dma_next_scb: 665 cmp SCB_LINKED_NEXT, SCB_LIST_NULL je add_to_free_list 666 test FLAGS, PAGESCBS jnz dma_next_scb2 667 /* Only DMA on top of ourselves if we are the SCB to download */ 668 mov A, SCB_LINKED_NEXT 669 cmp SCB_TAG, A je dma_next_scb2 670 mov SCBPTR, A 671 jmp add_to_waiting_list 672dma_next_scb2: 673 mvi DMAPARAMS, 0xd /* HDMAEN|DIRECTION|FIFORESET */ 674 mov SCB_LINKED_NEXT call dma_scb 675add_to_waiting_list: 676 mov SCB_NEXT,WAITING_SCBH 677 mov WAITING_SCBH, SCBPTR 678 jmp mesgin_done 679add_to_free_list: 680 call add_scb_to_free_list 681 jmp mesgin_done 682 683/* 684 * Is it an extended message? Copy the message to our message buffer and 685 * notify the host. The host will tell us whether to reject this message, 686 * respond to it with the message that the host placed in our message buffer, 687 * or simply to do nothing. 688 */ 689mesgin_extended: 690 mvi MSGIN_EXT_LEN call inb_next 691 mov A, MSGIN_EXT_LEN 692mesgin_extended_loop: 693 mov DINDEX call inb_next 694 dec A 695 cmp DINDEX, MSGIN_EXT_LASTBYTE jne mesgin_extended_loop_test 696 dec DINDEX /* dump by repeatedly filling the last byte */ 697mesgin_extended_loop_test: 698 test A, 0xFF jnz mesgin_extended_loop 699mesgin_extended_intr: 700 mvi INTSTAT,EXTENDED_MSG /* let driver know */ 701 cmp RETURN_1,SEND_REJ je rej_mesgin 702 cmp RETURN_1,SEND_MSG jne mesgin_done 703/* The kernel has setup a message to be sent */ 704 or SCSISIGO,ATNO /* turn on ATNO */ 705 jmp mesgin_done 706 707/* 708 * Is it a disconnect message? Set a flag in the SCB to remind us 709 * and await the bus going free. 710 */ 711mesgin_disconnect: 712 and SIMODE1, 0xf7 /* ~ENBUSFREE */ 713 or SCB_CONTROL,DISCONNECTED 714 test FLAGS, PAGESCBS jz mesgin_done 715 call add_scb_to_disc_list 716 jmp mesgin_done 717 718/* 719 * Save data pointers message: 720 * Copying RAM values back to SCB, for Save Data Pointers message, but 721 * only if we've actually been into a data phase to change them. This 722 * protects against bogus data in scratch ram and the residual counts 723 * since they are only initialized when we go into data_in or data_out. 724 */ 725mesgin_sdptrs: 726 test FLAGS, DPHASE jz mesgin_done 727 mov SCB_SGCOUNT,SG_COUNT 728 729 /* The SCB SGPTR becomes the next one we'll download */ 730 mvi DINDEX, SCB_SGPTR 731 mvi SG_NEXT0 call bcopy_4 732 733 /* The SCB DATAPTR0 becomes the current SHADDR */ 734 mvi DINDEX, SCB_DATAPTR0 735 mvi SHADDR0 call bcopy_4 736 737/* 738 * Use the residual number since STCNT is corrupted by any message transfer. 739 */ 740 mvi SCB_RESID_DCNT0 call bcopy_3 741 742 jmp mesgin_done 743 744/* 745 * Restore pointers message? Data pointers are recopied from the 746 * SCB anytime we enter a data phase for the first time, so all 747 * we need to do is clear the DPHASE flag and let the data phase 748 * code do the rest. 749 */ 750mesgin_rdptrs: 751 and FLAGS,0xef /* 752 * !DPHASE we'll reload them 753 * the next time through 754 */ 755 jmp mesgin_done 756 757/* 758 * Identify message? For a reconnecting target, this tells us the lun 759 * that the reconnection is for - find the correct SCB and switch to it, 760 * clearing the "disconnected" bit so we don't "find" it by accident later. 761 */ 762mesgin_identify: 763 test A,0x78 jnz rej_mesgin /*!DiscPriv|!LUNTAR|!Reserved*/ 764 and A,0x07 /* lun in lower three bits */ 765 or SAVED_TCL,A /* SAVED_TCL should be complete now */ 766 call inb_last /* ACK */ 767 768/* 769 * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message. 770 * If we get one, we use the tag returned to switch to find the proper 771 * SCB. With SCB paging, this requires using findSCB for both tagged 772 * and non-tagged transactions since the SCB may exist in any slot. 773 * If we're not using SCB paging, we can use the tag as the direct 774 * index to the SCB. 775 */ 776 mvi ARG_1,SCB_LIST_NULL /* Default to no-tag */ 777snoop_tag_loop: 778 test SSTAT1,REQINIT jz snoop_tag_loop 779 test SSTAT1,PHASEMIS jnz use_findSCB 780 mvi A call inb_first 781 cmp A,MSG_SIMPLE_Q_TAG jne use_findSCB 782get_tag: 783 or FLAGS, TAGGED_SCB 784 mvi ARG_1 call inb_next /* tag value */ 785/* 786 * See if the tag is in range. The tag is < SCBCOUNT if we add 787 * the complement of SCBCOUNT to the incomming tag and there is 788 * no carry. 789 */ 790 mov A,COMP_SCBCOUNT 791 add SINDEX,A,ARG_1 792 jc send_abort_msg 793 794/* 795 * Ensure that the SCB the tag points to is for an SCB transaction 796 * to the reconnecting target. 797 */ 798 test FLAGS, PAGESCBS jz index_by_tag 799use_findSCB: 800 mov ALLZEROS call findSCB /* Have to search */ 801 cmp SINDEX, SCB_LIST_NULL, je not_found 802setup_SCB: 803 and SCB_CONTROL,0xfb /* clear disconnect bit in SCB */ 804 or FLAGS,IDENTIFY_SEEN /* make note of IDENTIFY */ 805 test SCB_CONTROL,TAG_ENB jnz mesgin_done /* Ack Tag */ 806 jmp ITloop 807index_by_tag: 808 mov SCBPTR,ARG_1 809 mov A, SAVED_TCL 810 cmp SCB_TCL,A jne send_abort_msg 811 test SCB_CONTROL,TAG_ENB jz send_abort_msg 812 jmp setup_SCB 813 814not_found: 815 mvi INTSTAT, NO_MATCH 816send_abort_msg: 817 test FLAGS, TAGGED_SCB jnz abort_tag_msg 818 mvi MSG_ABORT call mk_mesg 819 jmp mesgin_done 820abort_tag_msg: 821 mvi MSG_ABORT_TAG call mk_mesg /* ABORT TAG message */ 822 jmp mesgin_done 823 824/* 825 * Message reject? Let the kernel driver handle this. If we have an 826 * outstanding WDTR or SDTR negotiation, assume that it's a response from 827 * the target selecting 8bit or asynchronous transfer, otherwise just ignore 828 * it since we have no clue what it pertains to. 829 */ 830mesgin_reject: 831 mvi INTSTAT, REJECT_MSG 832 jmp mesgin_done 833 834/* 835 * [ ADD MORE MESSAGE HANDLING HERE ] 836 */ 837 838/* 839 * Locking the driver out, build a one-byte message passed in SINDEX 840 * if there is no active message already. SINDEX is returned intact. 841 */ 842mk_mesg: 843 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 844 test MSG_LEN,0xff jz mk_mesg1 /* Should always succeed */ 845 846 /* 847 * Hmmm. For some reason the mesg buffer is in use. 848 * Tell the driver. It should look at SINDEX to find 849 * out what we wanted to use the buffer for and resolve 850 * the conflict. 851 */ 852 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 853 mvi INTSTAT,MSG_BUFFER_BUSY 854 855mk_mesg1: 856 or SCSISIGO,ATNO /* turn on ATNO */ 857 mvi MSG_LEN,1 /* length = 1 */ 858 mov MSG0,SINDEX /* 1-byte message */ 859 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 860 861/* 862 * Functions to read data in Automatic PIO mode. 863 * 864 * According to Adaptec's documentation, an ACK is not sent on input from 865 * the target until SCSIDATL is read from. So we wait until SCSIDATL is 866 * latched (the usual way), then read the data byte directly off the bus 867 * using SCSIBUSL. When we have pulled the ATN line, or we just want to 868 * acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI 869 * spec guarantees that the target will hold the data byte on the bus until 870 * we send our ACK. 871 * 872 * The assumption here is that these are called in a particular sequence, 873 * and that REQ is already set when inb_first is called. inb_{first,next} 874 * use the same calling convention as inb. 875 */ 876 877inb_next: 878 call inb_last /* ACK */ 879inb_next_wait: 880 test SSTAT0, SPIORDY jz inb_next_wait 881 test SSTAT1,PHASEMIS jnz mesgin_phasemis 882inb_first: 883 mov DINDEX,SINDEX 884 mov DINDIR,SCSIBUSL ret /*read byte directly from bus*/ 885inb_last: 886 mvi CLRSINT0, CLRSPIORDY 887 mov NONE,SCSIDATL ret /*dummy read from latch to ACK*/ 888 889mesgin_phasemis: 890/* 891 * We expected to receive another byte, but the target changed phase 892 */ 893 mvi INTSTAT, MSGIN_PHASEMIS 894 jmp ITloop 895 896/* 897 * DMA data transfer. HADDR and HCNT must be loaded first, and 898 * SINDEX should contain the value to load DFCNTRL with - 0x3d for 899 * host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared 900 * during initialization. 901 */ 902dma: 903 mov DFCNTRL,SINDEX 904dma1: 905 test SSTAT0,DMADONE jnz dma3 906 test SSTAT1,PHASEMIS jz dma1 /* ie. underrun */ 907 908/* 909 * We will be "done" DMAing when the transfer count goes to zero, or 910 * the target changes the phase (in light of this, it makes sense that 911 * the DMA circuitry doesn't ACK when PHASEMIS is active). If we are 912 * doing a SCSI->Host transfer, the data FIFO should be flushed auto- 913 * magically on STCNT=0 or a phase change, so just wait for FIFO empty 914 * status. 915 */ 916dma3: 917 test SINDEX,DIRECTION jnz dma5 918dma4: 919 test DFSTATUS,FIFOEMP jz dma4 920 921/* 922 * Now shut the DMA enables off and make sure that the DMA enables are 923 * actually off first lest we get an ILLSADDR. 924 */ 925dma5: 926 /* disable DMA, but maintain WIDEODD */ 927 and DFCNTRL,WIDEODD 928dma6: 929 test DFCNTRL,0x38 jnz dma6 /* SCSIENACK|SDMAENACK|HDMAENACK */ 930return: 931 ret 932 933/* 934 * Common SCSI initialization for selection and reselection. Expects 935 * the target SCSI ID to be in the upper four bits of SINDEX, and A's 936 * contents are stomped on return. 937 */ 938initialize_scsiid: 939 and SINDEX,0xf0 /* Get target ID */ 940 mov SAVED_TCL, SINDEX /* Update the target portion of this */ 941 and A,0x0f,SCSIID 942 or SINDEX,A 943 mov SCSIID,SINDEX ret 944 945/* 946 * Assert that if we've been reselected, then we've seen an IDENTIFY 947 * message. 948 */ 949assert: 950 test FLAGS,RESELECTED jz return /* reselected? */ 951 test FLAGS,IDENTIFY_SEEN jnz return /* seen IDENTIFY? */ 952 953 mvi INTSTAT,NO_IDENT ret /* no - tell the kernel */ 954 955/* 956 * Locate a disconnected SCB either by SAVED_TCL (ARG_1 is SCB_LIST_NULL) 957 * or by the SCBIDn ARG_1. The search begins at the SCB index passed in 958 * via SINDEX. If the SCB cannot be found, SINDEX will be SCB_LIST_NULL, 959 * otherwise, SCBPTR is set to the proper SCB. 960 */ 961findSCB: 962 mov SCBPTR,SINDEX /* switch to next SCB */ 963 test SCB_CONTROL,DISCONNECTED jz findSCB1 /*should be disconnected*/ 964 cmp ARG_1, SCB_LIST_NULL jne findBySCBID 965 mov A, SAVED_TCL 966 cmp SCB_TCL,A je foundSCB /* target ID/channel/lun match? */ 967findSCB1: 968 inc SINDEX 969 mov A,SCBCOUNT 970 cmp SINDEX,A jne findSCB 971/* 972 * We didn't find it. If we're paging, pull an SCB and DMA down the 973 * one we want. If we aren't paging or the SCB we dma down has the 974 * abort flag set, return not found. 975 */ 976 test FLAGS, PAGESCBS jz find_error 977 mov ALLZEROS call get_free_or_disc_scb 978 cmp ARG_1, SCB_LIST_NULL jne find_dma_scb 979 mov SAVED_TCL call index_untagged_scb 980 mov ARG_1, SINDIR /* SCBID of SCB to fetch */ 981find_dma_scb: 982 mvi DMAPARAMS, 0xd /* HDMAEN|DIRECTION|FIFORESET */ 983 mov ARG_1 call dma_scb 984 test SCB_CONTROL, ABORT_SCB jz return 985find_error: 986 mvi SINDEX, SCB_LIST_NULL ret 987findBySCBID: 988 mov A, ARG_1 /* Tag passed in ARG_1 */ 989 cmp SCB_TAG,A jne findSCB1 /* Found it? */ 990foundSCB: 991 test SCB_CONTROL, ABORT_SCB jnz find_error 992 test FLAGS,PAGESCBS jz return 993rem_scb_from_disc_list: 994/* Remove this SCB from the disconnection list */ 995 cmp SCB_NEXT,SCB_LIST_NULL je unlink_prev 996 mov SAVED_LINKPTR, SCB_PREV 997 mov SCBPTR, SCB_NEXT 998 mov SCB_PREV, SAVED_LINKPTR 999 mov SCBPTR, SINDEX 1000unlink_prev: 1001 cmp SCB_PREV,SCB_LIST_NULL je rHead/* At the head of the list */ 1002 mov SAVED_LINKPTR, SCB_NEXT 1003 mov SCBPTR, SCB_PREV 1004 mov SCB_NEXT, SAVED_LINKPTR 1005 mov SCBPTR, SINDEX ret 1006rHead: 1007 mov DISCONNECTED_SCBH,SCB_NEXT ret 1008 1009set_stcnt_from_hcnt: 1010 mov STCNT0, HCNT0 1011 mov STCNT1, HCNT1 1012 mov STCNT2, HCNT2 ret 1013 1014bcopy_7: 1015 mov DINDIR, SINDIR 1016 mov DINDIR, SINDIR 1017bcopy_5: 1018 mov DINDIR, SINDIR 1019bcopy_4: 1020 mov DINDIR, SINDIR 1021bcopy_3: 1022 mov DINDIR, SINDIR 1023 mov DINDIR, SINDIR 1024 mov DINDIR, SINDIR ret 1025 1026dma_scb: 1027 /* 1028 * SCB index is in SINDEX. Determine the physical address in 1029 * the host where this SCB is located and load HADDR with it. 1030 */ 1031 shr DINDEX, SINDEX, 3 1032 shl A, SINDEX, 5 1033 add HADDR0, A, HSCB_ADDR0 1034 mov A, DINDEX 1035 adc HADDR1, A, HSCB_ADDR1 1036 clr A 1037 adc HADDR2, A, HSCB_ADDR2 1038 adc HADDR3, A, HSCB_ADDR3 1039 /* Setup Count */ 1040 mvi HCNT0, 28 1041 clr HCNT1 1042 clr HCNT2 1043 mov DFCNTRL, DMAPARAMS 1044 test DMAPARAMS, DIRECTION jnz dma_scb_fromhost 1045 /* Fill it with the SCB data */ 1046 call copy_scb_tofifo 1047 mvi DFCNTRL, 0xa /* HDMAEN | FIFOFLUSH */ 1048dma_scb_fromhost: 1049 call dma_finish 1050 /* If we were putting the SCB, we are done */ 1051 test DMAPARAMS, DIRECTION jz return 1052 mvi SCBARRAY call dfdat_in_7 1053 call dfdat_in_7_continued 1054 call dfdat_in_7_continued 1055 jmp dfdat_in_7_continued 1056dfdat_in_7: 1057 mov DINDEX,SINDEX 1058dfdat_in_7_continued: 1059 mov DINDIR,DFDAT 1060 mov DINDIR,DFDAT 1061 mov DINDIR,DFDAT 1062 mov DINDIR,DFDAT 1063 mov DINDIR,DFDAT 1064 mov DINDIR,DFDAT 1065 mov DINDIR,DFDAT ret 1066 1067copy_scb_tofifo: 1068 mvi SCBARRAY call dfdat_out_7 1069 call dfdat_out_7 1070 call dfdat_out_7 1071dfdat_out_7: 1072 mov DFDAT,SINDIR 1073 mov DFDAT,SINDIR 1074 mov DFDAT,SINDIR 1075 mov DFDAT,SINDIR 1076 mov DFDAT,SINDIR 1077 mov DFDAT,SINDIR 1078 mov DFDAT,SINDIR ret 1079 1080/* 1081 * Wait for DMA from host memory to data FIFO to complete, then disable 1082 * DMA and wait for it to acknowledge that it's off. 1083 */ 1084dma_finish: 1085 test DFSTATUS,HDONE jz dma_finish 1086 /* Turn off DMA preserving WIDEODD */ 1087 and DFCNTRL,WIDEODD 1088dma_finish2: 1089 test DFCNTRL,HDMAENACK jnz dma_finish2 1090 ret 1091 1092index_untagged_scb: 1093 mov DINDEX, SINDEX 1094 shr DINDEX, 4 1095 and DINDEX, 0x03 /* Bottom two bits of tid */ 1096 add DINDEX, SCB_ACTIVE0 1097 shr A, SINDEX, 6 /* Target ID divided by 4 */ 1098 test SINDEX, SELBUSB jz index_untagged_scb2 1099 add A, 2 /* Add 2 positions */ 1100index_untagged_scb2: 1101 mov SCBPTR, A /* 1102 * Select the SCB with this 1103 * target's information. 1104 */ 1105 mov SINDEX, DINDEX ret 1106 1107 1108get_free_or_disc_scb: 1109 cmp FREE_SCBH, SCB_LIST_NULL jne dequeue_free_scb 1110 cmp DISCONNECTED_SCBH, SCB_LIST_NULL jne dequeue_disc_scb 1111return_error: 1112 mvi SINDEX, SCB_LIST_NULL ret 1113dequeue_disc_scb: 1114 mov SCBPTR, DISCONNECTED_SCBH 1115/* 1116 * If we have a residual, then we are in the middle of some I/O 1117 * and we have to send this SCB back up to the kernel so that the 1118 * saved data pointers and residual information isn't lost. 1119 */ 1120 test SCB_RESID_SGCNT,0xff jz unlink_disc_scb 1121 mvi DMAPARAMS, 0x9 /* HDMAEN | FIFORESET*/ 1122 mov SCB_TAG call dma_scb 1123unlink_disc_scb: 1124 /* jmp instead of call since we want to return anyway */ 1125 mov SCBPTR jmp rem_scb_from_disc_list 1126dequeue_free_scb: 1127 mov SCBPTR, FREE_SCBH 1128 mov FREE_SCBH, SCB_NEXT ret 1129 1130add_scb_to_free_list: 1131 mov SCB_NEXT, FREE_SCBH 1132 mov FREE_SCBH, SCBPTR ret 1133 1134add_scb_to_disc_list: 1135/* 1136 * Link this SCB into the DISCONNECTED list. This list holds the 1137 * candidates for paging out an SCB if one is needed for a new command. 1138 * Modifying the disconnected list is a critical(pause dissabled) section. 1139 */ 1140 mvi SCB_PREV, SCB_LIST_NULL 1141 mov SCB_NEXT, DISCONNECTED_SCBH 1142 mov DISCONNECTED_SCBH, SCBPTR 1143 cmp SCB_NEXT,SCB_LIST_NULL je return 1144 mov SCBPTR,SCB_NEXT 1145 mov SCB_PREV,DISCONNECTED_SCBH 1146 mov SCBPTR,DISCONNECTED_SCBH ret 1147 1148