aic7xxx.seq revision 22078
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, 1997 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 "$FreeBSD: head/sys/dev/aic7xxx/aic7xxx.seq 22078 1997-01-29 05:19:46Z gibbs $" 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 or SXFRCTL0, CLRCHN 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 SCSISEQ,ENRSELI /* Always allow reselection */ 94 mvi LASTPHASE, P_BUSFREE 95 and FLAGS,0x07 /* clear target specific flags */ 96poll_for_work: 97 /* 98 * Are we a twin channel device? 99 * For fairness, we check the other bus first, 100 * since we just finished a transaction on the 101 * current channel. 102 */ 103 test FLAGS,TWIN_BUS jz start2 104 xor SBLKCTL,SELBUSB /* Toggle to the other bus */ 105 test SSTAT0,SELDI jnz reselect 106 xor SBLKCTL,SELBUSB /* Toggle to the original bus */ 107start2: 108 test SSTAT0,SELDI jnz reselect 109 cmp WAITING_SCBH,SCB_LIST_NULL je test_queue 110start_waiting: 111 /* 112 * Pull the first entry off of the waiting SCB list 113 * We don't have to "test_busy" because only transactions that 114 * have passed that test can be in the WAITING_SCB list. 115 */ 116 mov SCBPTR,WAITING_SCBH 117 jmp start_scb2 118test_queue: 119 /* Has the driver posted any work for us? */ 120 mov A, QCNTMASK 121 test QINCNT,A jz poll_for_work 122 123/* 124 * We have at least one queued SCB now and we don't have any 125 * SCBs in the list of SCBs awaiting selection. If we have 126 * any SCBs availible for use, pull the tag from the QINFIFO 127 * and get to work on it. 128 */ 129 test FLAGS, PAGESCBS jz dequeue_scb 130 mov ALLZEROS call get_free_or_disc_scb 131 cmp SINDEX, SCB_LIST_NULL je poll_for_work 132dequeue_scb: 133 mov CUR_SCBID,QINFIFO 134 test FLAGS, PAGESCBS jnz dma_queued_scb 135 /* In the non-paging case, the SCBID == hardware SCB index */ 136 mov SCBPTR, CUR_SCBID 137dma_queued_scb: 138/* 139 * DMA the SCB from host ram into the current SCB location. 140 */ 141 mvi DMAPARAMS, 0xd /* HDMAEN|DIRECTION|FIFORESET */ 142 mov CUR_SCBID call dma_scb 143 144/* 145 * See if there is not already an active SCB for this target. This code 146 * locks out on a per target basis instead of target/lun. Although this 147 * is not ideal for devices that have multiple luns active at the same 148 * time, it is faster than looping through all SCB's looking for active 149 * commands. We also don't have enough spare SCB space for us to store the 150 * SCBID of the currently busy transaction for each target/lun making it 151 * impossible to link up the SCBs. 152 */ 153test_busy: 154 test SCB_CONTROL, TAG_ENB jnz start_scb 155 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 156 mov SAVED_SCBPTR, SCBPTR 157 mov SCB_TCL call index_untagged_scb 158 mov ARG_1, SINDIR /* 159 * ARG_1 should 160 * now have the SCB ID of 161 * any active, non-tagged, 162 * command for this target. 163 */ 164 cmp ARG_1, SCB_LIST_NULL je make_busy 165 test FLAGS, PAGESCBS jz simple_busy_link 166 /* 167 * Put this SCB back onto the free list. It 168 * may be necessary to satisfy the search for 169 * the active SCB. 170 */ 171 mov SCBPTR, SAVED_SCBPTR 172 call add_scb_to_free_list 173 /* Find the active SCB */ 174 mov ALLZEROS call findSCB 175 /* 176 * If we couldn't find it, tell the kernel. This should 177 * never happen. 178 */ 179 cmp SINDEX, SCB_LIST_NULL jne paged_busy_link 180 mvi INTSTAT, NO_MATCH_BUSY 181paged_busy_link: 182 /* Link us in */ 183 mov SCB_LINKED_NEXT, CUR_SCBID 184 /* Put it back on the disconnected list */ 185 call add_scb_to_disc_list 186 mvi SEQCTL,0x10 /* FASTMODE */ 187 jmp poll_for_work 188simple_busy_link: 189 mov SCBPTR, ARG_1 190 mov SCB_LINKED_NEXT, CUR_SCBID 191 mvi SEQCTL,0x10 /* FASTMODE */ 192 jmp poll_for_work 193make_busy: 194 mov DINDIR, CUR_SCBID 195 mov SCBPTR, SAVED_SCBPTR 196 mvi SEQCTL,0x10 /* FASTMODE */ 197 198start_scb: 199 /* 200 * Place us on the waiting list in case our selection 201 * doesn't win during bus arbitration. 202 */ 203 mov SCB_NEXT,WAITING_SCBH 204 mov WAITING_SCBH, SCBPTR 205start_scb2: 206 and SINDEX,0xf7,SBLKCTL /* Clear the channel select bit */ 207 and A,0x08,SCB_TCL /* Get new channel bit */ 208 or SINDEX,A 209 mov SBLKCTL,SINDEX /* select channel */ 210 mov SCB_TCL call initialize_scsiid 211 212/* 213 * Enable selection phase as an initiator, and do automatic ATN 214 * after the selection. We do this now so that we can overlap the 215 * rest of our work to set up this target with the arbitration and 216 * selection bus phases. 217 */ 218start_selection: 219 mvi SCSISEQ,0x58 /* ENSELO|ENAUTOATNO|ENRSELI */ 220 221/* 222 * As soon as we get a successful selection, the target should go 223 * into the message out phase since we have ATN asserted. Prepare 224 * the message to send. 225 * 226 * Messages are stored in scratch RAM starting with a length byte 227 * followed by the message itself. 228 */ 229 230mk_identify: 231 and MSG0,0x7,SCB_TCL /* lun */ 232 and A,DISCENB,SCB_CONTROL /* mask off disconnect privledge */ 233 or MSG0,A /* or in disconnect privledge */ 234 or MSG0,MSG_IDENTIFYFLAG 235 mvi MSG_LEN, 1 236 237/* 238 * Send a tag message if TAG_ENB is set in the SCB control block. 239 * Use SCB_TAG (the position in the kernel's SCB array) as the tag value. 240 */ 241mk_tag: 242 test SCB_CONTROL,TAG_ENB jz mk_message 243 and MSG1,0x23,SCB_CONTROL 244 mov MSG2,SCB_TAG 245 add MSG_LEN,2 /* update message length */ 246 247/* 248 * Interrupt the driver, and allow it to tweak the message buffer 249 * if it asks. 250 */ 251mk_message: 252 test SCB_CONTROL,MK_MESSAGE jz wait_for_selection 253 254 mvi INTSTAT,AWAITING_MSG 255 256wait_for_selection: 257 test SSTAT0,SELDO jnz select 258 test SSTAT0,SELDI jz wait_for_selection 259 260/* 261 * Reselection has been initiated by a target. Make a note that we've been 262 * reselected, but haven't seen an IDENTIFY message from the target yet. 263 */ 264reselect: 265 clr MSG_LEN /* Don't have anything in the mesg buffer */ 266 /* XXX test for and handle ONE BIT condition */ 267 and SAVED_TCL, 0xf0, SELID 268 or FLAGS,RESELECTED 269 jmp select2 270 271/* 272 * After the selection, remove this SCB from the "waiting SCB" 273 * list. This is achieved by simply moving our "next" pointer into 274 * WAITING_SCBH. Our next pointer will be set to null the next time this 275 * SCB is used, so don't bother with it now. 276 */ 277select: 278 mov WAITING_SCBH,SCB_NEXT 279select2: 280 /* Turn off the selection hardware */ 281 mvi SCSISEQ,ENAUTOATNP /* 282 * ATN on parity errors 283 * for "in" phases 284 */ 285 mvi CLRSINT0,0x60 /* CLRSELDI|CLRSELDO */ 286 mvi CLRSINT1,CLRBUSFREE 287 or SIMODE1, ENBUSFREE /* 288 * We aren't expecting a 289 * bus free, so interrupt 290 * the kernel driver if it 291 * happens. 292 */ 293/* 294 * Initialize SCSIRATE with the appropriate value for this target. 295 * The SCSIRATE settings for each target are stored in an array 296 * based at TARG_SCRATCH. 297 */ 298ndx_dtr: 299 shr A,SAVED_TCL,4 300 test SBLKCTL,SELBUSB jz ndx_dtr_2 301 or SAVED_TCL, SELBUSB /* Add the channel bit while we're here */ 302 or A,0x08 /* Channel B entries add 8 */ 303ndx_dtr_2: 304 add SINDEX,TARG_SCRATCH,A 305 mov SCSIRATE,SINDIR 306 307/* 308 * Initialize Ultra mode setting and clear the SCSI channel. 309 */ 310ultra: 311 and DINDEX,0xdf,SXFRCTL0 /* default to Ultra disabled */ 312 mvi SINDEX, ULTRA_ENB_B 313 test SAVED_TCL, 0x80 jnz ultra_2 /* Target ID > 7 */ 314 test SBLKCTL, SELBUSB jnz ultra_2 /* Second channel device */ 315 dec SINDEX 316ultra_2: 317 mov FUNCTION1,SAVED_TCL 318 mov A,FUNCTION1 319 test SINDIR, A jz set_sxfrctl0 320 or DINDEX, ULTRAEN 321 322set_sxfrctl0: 323 mov SXFRCTL0,DINDEX 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 */ 511 jmp ITloop 512 513/* 514 * Status phase. Wait for the data byte to appear, then read it 515 * and store it into the SCB. 516 */ 517p_status: 518 call assert 519 520 mov SCB_TARGET_STATUS, SCSIDATL 521 jmp ITloop 522 523/* 524 * Message out phase. If there is not an active message, but the target 525 * took us into this phase anyway, build a no-op message and send it. 526 */ 527p_mesgout: 528 test MSG_LEN, 0xff jnz p_mesgout_start 529 mvi MSG_NOOP call mk_mesg /* build NOP message */ 530p_mesgout_start: 531/* 532 * Set up automatic PIO transfer from MSG0. Bit 3 in 533 * SXFRCTL0 (SPIOEN) is already on. 534 */ 535 mvi SINDEX,MSG0 536 mov DINDEX,MSG_LEN 537 538/* 539 * When target asks for a byte, drop ATN if it's the last one in 540 * the message. Otherwise, keep going until the message is exhausted. 541 * 542 * Keep an eye out for a phase change, in case the target issues 543 * a MESSAGE REJECT. 544 */ 545p_mesgout_loop: 546 /* 547 * If there is a parity error, wait for the kernel to 548 * see the interrupt and "update" our message response 549 * before continuing. 550 */ 551 test SSTAT1, REQINIT jz p_mesgout_loop 552 test SSTAT1, SCSIPERR jnz p_mesgout_loop 553 and LASTPHASE, PHASE_MASK, SCSISIGI 554 cmp LASTPHASE, P_MESGOUT jne p_mesgout_done 555/* 556 * If the next bus phase after ATN drops is a message out, it means 557 * that the target is requesting that the last message(s) be resent. 558 */ 559p_mesgout_testretry: 560 test DINDEX,0xff jnz p_mesgout_dropatn 561 or SCSISIGO,ATNO,LASTPHASE /* turn on ATN for the retry */ 562 jmp p_mesgout_start 563p_mesgout_dropatn: 564 cmp DINDEX,1 jne p_mesgout_outb /* last byte? */ 565 mvi CLRSINT1,CLRATNO /* drop ATN */ 566p_mesgout_outb: 567 dec DINDEX 568 mvi CLRSINT0, CLRSPIORDY 569 mov SCSIDATL,SINDIR 570 jmp p_mesgout_loop 571 572p_mesgout_done: 573 mvi CLRSINT1,CLRATNO /* Be sure to turn ATNO off */ 574 clr MSG_LEN /* no active msg */ 575 jmp ITloop 576 577/* 578 * Message in phase. Bytes are read using Automatic PIO mode. 579 */ 580p_mesgin: 581 mvi A call inb_first /* read the 1st message byte */ 582 mov REJBYTE,A /* save it for the driver */ 583 584 test A,MSG_IDENTIFYFLAG jnz mesgin_identify 585 cmp A,MSG_DISCONNECT je mesgin_disconnect 586 cmp A,MSG_SAVEDATAPOINTER je mesgin_sdptrs 587 cmp ALLZEROS,A je mesgin_complete 588 cmp A,MSG_RESTOREPOINTERS je mesgin_rdptrs 589 cmp A,MSG_EXTENDED je mesgin_extended 590 cmp A,MSG_MESSAGE_REJECT je mesgin_reject 591 592rej_mesgin: 593/* 594 * We have no idea what this message in is, so we issue a message reject 595 * and hope for the best. In any case, rejection should be a rare 596 * occurrence - signal the driver when it happens. 597 */ 598 mvi INTSTAT,SEND_REJECT /* let driver know */ 599 600 mvi MSG_MESSAGE_REJECT call mk_mesg 601 602mesgin_done: 603 call inb_last /*ack & turn auto PIO back on*/ 604 jmp ITloop 605 606 607mesgin_complete: 608/* 609 * We got a "command complete" message, so put the SCB_TAG into the QOUTFIFO, 610 * and trigger a completion interrupt. Before doing so, check to see if there 611 * is a residual or the status byte is something other than NO_ERROR (0). In 612 * either of these conditions, we upload the SCB back to the host so it can 613 * process this information. In the case of a non zero status byte, we 614 * additionally interrupt the kernel driver synchronously, allowing it to 615 * decide if sense should be retrieved. If the kernel driver wishes to request 616 * sense, it will fill the kernel SCB with a request sense command and set 617 * RETURN_1 to SEND_SENSE. If RETURN_1 is set to SEND_SENSE we redownload 618 * the SCB, and process it as the next command by adding it to the waiting list. 619 * If the kernel driver does not wish to request sense, it need only clear 620 * RETURN_1, and the command is allowed to complete normally. We don't bother 621 * to post to the QOUTFIFO in the error cases since it would require extra 622 * work in the kernel driver to ensure that the entry was removed before the 623 * command complete code tried processing it. 624 */ 625 626/* 627 * We expect to go to bus free after this message. 628 */ 629 and SIMODE1, 0xf7 /* ~ENBUSFREE */ 630/* 631 * First check for residuals 632 */ 633 test SCB_RESID_SGCNT,0xff jnz upload_scb 634 test SCB_TARGET_STATUS,0xff jz status_ok /* Good Status? */ 635upload_scb: 636 mvi DMAPARAMS, 0x9 /* HDMAEN | FIFORESET*/ 637 mov SCB_TAG call dma_scb 638check_status: 639 test SCB_TARGET_STATUS,0xff jz status_ok /* Just a residual? */ 640 mvi INTSTAT,BAD_STATUS /* let driver know */ 641 cmp RETURN_1, SEND_SENSE jne status_ok 642 /* This SCB becomes the next to execute as it will retrieve sense */ 643 mov SCB_LINKED_NEXT, SCB_TAG 644 jmp dma_next_scb 645 646status_ok: 647/* First, mark this target as free. */ 648 test SCB_CONTROL,TAG_ENB jnz complete /* 649 * Tagged commands 650 * don't busy the 651 * target. 652 */ 653 mov SAVED_SCBPTR, SCBPTR 654 mov SAVED_LINKPTR, SCB_LINKED_NEXT 655 mov SCB_TCL call index_untagged_scb 656 mov DINDIR, SAVED_LINKPTR 657 mov SCBPTR, SAVED_SCBPTR 658 659complete: 660 /* Post the SCB and issue an interrupt */ 661 mov QOUTFIFO,SCB_TAG 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,LASTPHASE /* 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 and LASTPHASE, PHASE_MASK, SCSISIGI 780 cmp LASTPHASE, P_MESGIN, jne use_findSCB 781 mvi A call inb_first 782 cmp A,MSG_SIMPLE_Q_TAG jne use_findSCB 783get_tag: 784 or FLAGS, TAGGED_SCB 785 mvi ARG_1 call inb_next /* tag value */ 786/* 787 * See if the tag is in range. The tag is < SCBCOUNT if we add 788 * the complement of SCBCOUNT to the incomming tag and there is 789 * no carry. 790 */ 791 mov A,COMP_SCBCOUNT 792 add SINDEX,A,ARG_1 793 jc send_abort_msg 794 795/* 796 * Ensure that the SCB the tag points to is for an SCB transaction 797 * to the reconnecting target. 798 */ 799 test FLAGS, PAGESCBS jz index_by_tag 800use_findSCB: 801 mov ALLZEROS call findSCB /* Have to search */ 802 cmp SINDEX, SCB_LIST_NULL, je not_found 803setup_SCB: 804 and SCB_CONTROL,0xfb /* clear disconnect bit in SCB */ 805 or FLAGS,IDENTIFY_SEEN /* make note of IDENTIFY */ 806 test SCB_CONTROL,TAG_ENB jnz mesgin_done /* Ack Tag */ 807 jmp ITloop 808index_by_tag: 809 mov SCBPTR,ARG_1 810 mov A, SAVED_TCL 811 cmp SCB_TCL,A jne send_abort_msg 812 test SCB_CONTROL,TAG_ENB jz send_abort_msg 813 jmp setup_SCB 814 815not_found: 816 mvi INTSTAT, NO_MATCH 817send_abort_msg: 818 test FLAGS, TAGGED_SCB jnz abort_tag_msg 819 mvi MSG_ABORT call mk_mesg 820 jmp mesgin_done 821abort_tag_msg: 822 mvi MSG_ABORT_TAG call mk_mesg /* ABORT TAG message */ 823 jmp mesgin_done 824 825/* 826 * Message reject? Let the kernel driver handle this. If we have an 827 * outstanding WDTR or SDTR negotiation, assume that it's a response from 828 * the target selecting 8bit or asynchronous transfer, otherwise just ignore 829 * it since we have no clue what it pertains to. 830 */ 831mesgin_reject: 832 mvi INTSTAT, REJECT_MSG 833 jmp mesgin_done 834 835/* 836 * [ ADD MORE MESSAGE HANDLING HERE ] 837 */ 838 839/* 840 * Locking the driver out, build a one-byte message passed in SINDEX 841 * if there is no active message already. SINDEX is returned intact. 842 */ 843mk_mesg: 844 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 845 test MSG_LEN,0xff jz mk_mesg1 /* Should always succeed */ 846 847 /* 848 * Hmmm. For some reason the mesg buffer is in use. 849 * Tell the driver. It should look at SINDEX to find 850 * out what we wanted to use the buffer for and resolve 851 * the conflict. 852 */ 853 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 854 mvi INTSTAT,MSG_BUFFER_BUSY 855 856mk_mesg1: 857 or SCSISIGO,ATNO,LASTPHASE /* turn on ATNO */ 858 mvi MSG_LEN,1 /* length = 1 */ 859 mov MSG0,SINDEX /* 1-byte message */ 860 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 861 862/* 863 * Functions to read data in Automatic PIO mode. 864 * 865 * According to Adaptec's documentation, an ACK is not sent on input from 866 * the target until SCSIDATL is read from. So we wait until SCSIDATL is 867 * latched (the usual way), then read the data byte directly off the bus 868 * using SCSIBUSL. When we have pulled the ATN line, or we just want to 869 * acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI 870 * spec guarantees that the target will hold the data byte on the bus until 871 * we send our ACK. 872 * 873 * The assumption here is that these are called in a particular sequence, 874 * and that REQ is already set when inb_first is called. inb_{first,next} 875 * use the same calling convention as inb. 876 */ 877 878inb_next: 879 mov NONE,SCSIDATL /*dummy read from latch to ACK*/ 880inb_next_wait: 881 /* 882 * If there is a parity error, wait for the kernel to 883 * see the interrupt and prepare our message response 884 * before continuing. 885 */ 886 test SSTAT1, REQINIT jz inb_next_wait 887 test SSTAT1, SCSIPERR jnz inb_next_wait 888 and LASTPHASE, PHASE_MASK, SCSISIGI 889 cmp LASTPHASE, P_MESGIN jne mesgin_phasemis 890inb_first: 891 mov DINDEX,SINDEX 892 mov DINDIR,SCSIBUSL ret /*read byte directly from bus*/ 893inb_last: 894 mov NONE,SCSIDATL ret /*dummy read from latch to ACK*/ 895 896mesgin_phasemis: 897/* 898 * We expected to receive another byte, but the target changed phase 899 */ 900 mvi INTSTAT, MSGIN_PHASEMIS 901 jmp ITloop 902 903/* 904 * DMA data transfer. HADDR and HCNT must be loaded first, and 905 * SINDEX should contain the value to load DFCNTRL with - 0x3d for 906 * host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared 907 * during initialization. 908 */ 909dma: 910 mov DFCNTRL,SINDEX 911dma1: 912 test SSTAT0,DMADONE jnz dma3 913 test SSTAT1,PHASEMIS jz dma1 /* ie. underrun */ 914 915/* 916 * We will be "done" DMAing when the transfer count goes to zero, or 917 * the target changes the phase (in light of this, it makes sense that 918 * the DMA circuitry doesn't ACK when PHASEMIS is active). If we are 919 * doing a SCSI->Host transfer, the data FIFO should be flushed auto- 920 * magically on STCNT=0 or a phase change, so just wait for FIFO empty 921 * status. 922 */ 923dma3: 924 test SINDEX,DIRECTION jnz dma5 925dma4: 926 test DFSTATUS,FIFOEMP jz dma4 927 928/* 929 * Now shut the DMA enables off and make sure that the DMA enables are 930 * actually off first lest we get an ILLSADDR. 931 */ 932dma5: 933 /* Don't clobber an inprogress host data transfer */ 934 test DFSTATUS, MREQPEND jnz dma5 935 /* disable DMA */ 936 and DFCNTRL, 0xc7 /* ~(SCSIEN|SDMAEN|HDMAEN|DIRECTION) */ 937dma6: 938 test DFCNTRL, 0x38 jnz dma6 /* (SCSIEN|SDMAEN|HDMAEN|DIRECTION) */ 939return: 940 ret 941 942/* 943 * Common SCSI initialization for selection and reselection. Expects 944 * the target SCSI ID to be in the upper four bits of SINDEX, and A's 945 * contents are stomped on return. 946 */ 947initialize_scsiid: 948 and SINDEX,0xf0 /* Get target ID */ 949 mov SAVED_TCL, SINDEX /* Update the target portion of this */ 950 and A,0x0f,SCSIID 951 or SINDEX,A 952 mov SCSIID,SINDEX ret 953 954/* 955 * Assert that if we've been reselected, then we've seen an IDENTIFY 956 * message. 957 */ 958assert: 959 test FLAGS,RESELECTED jz return /* reselected? */ 960 test FLAGS,IDENTIFY_SEEN jnz return /* seen IDENTIFY? */ 961 962 mvi INTSTAT,NO_IDENT ret /* no - tell the kernel */ 963 964/* 965 * Locate a disconnected SCB either by SAVED_TCL (ARG_1 is SCB_LIST_NULL) 966 * or by the SCBIDn ARG_1. The search begins at the SCB index passed in 967 * via SINDEX. If the SCB cannot be found, SINDEX will be SCB_LIST_NULL, 968 * otherwise, SCBPTR is set to the proper SCB. 969 */ 970findSCB: 971 mov SCBPTR,SINDEX /* switch to next SCB */ 972 test SCB_CONTROL,DISCONNECTED jz findSCB1 /*should be disconnected*/ 973 cmp ARG_1, SCB_LIST_NULL jne findBySCBID 974 mov A, SAVED_TCL 975 cmp SCB_TCL,A je foundSCB /* target ID/channel/lun match? */ 976findSCB1: 977 inc SINDEX 978 mov A,SCBCOUNT 979 cmp SINDEX,A jne findSCB 980/* 981 * We didn't find it. If we're paging, pull an SCB and DMA down the 982 * one we want. If we aren't paging or the SCB we dma down has the 983 * abort flag set, return not found. 984 */ 985 test FLAGS, PAGESCBS jz find_error 986 mov ALLZEROS call get_free_or_disc_scb 987 cmp ARG_1, SCB_LIST_NULL jne find_dma_scb 988 mov SAVED_TCL call index_untagged_scb 989 mov ARG_1, SINDIR /* SCBID of SCB to fetch */ 990find_dma_scb: 991 mvi DMAPARAMS, 0xd /* HDMAEN|DIRECTION|FIFORESET */ 992 mov ARG_1 call dma_scb 993 test SCB_CONTROL, ABORT_SCB jz return 994 call add_scb_to_free_list 995find_error: 996 mvi SINDEX, SCB_LIST_NULL ret 997findBySCBID: 998 mov A, ARG_1 /* Tag passed in ARG_1 */ 999 cmp SCB_TAG,A jne findSCB1 /* Found it? */ 1000foundSCB: 1001 test SCB_CONTROL, ABORT_SCB jnz find_error 1002 test FLAGS,PAGESCBS jz return 1003rem_scb_from_disc_list: 1004/* Remove this SCB from the disconnection list */ 1005 cmp SCB_NEXT,SCB_LIST_NULL je unlink_prev 1006 mov SAVED_LINKPTR, SCB_PREV 1007 mov SCBPTR, SCB_NEXT 1008 mov SCB_PREV, SAVED_LINKPTR 1009 mov SCBPTR, SINDEX 1010unlink_prev: 1011 cmp SCB_PREV,SCB_LIST_NULL je rHead/* At the head of the list */ 1012 mov SAVED_LINKPTR, SCB_NEXT 1013 mov SCBPTR, SCB_PREV 1014 mov SCB_NEXT, SAVED_LINKPTR 1015 mov SCBPTR, SINDEX ret 1016rHead: 1017 mov DISCONNECTED_SCBH,SCB_NEXT ret 1018 1019set_stcnt_from_hcnt: 1020 mov STCNT0, HCNT0 1021 mov STCNT1, HCNT1 1022 mov STCNT2, HCNT2 ret 1023 1024bcopy_7: 1025 mov DINDIR, SINDIR 1026 mov DINDIR, SINDIR 1027bcopy_5: 1028 mov DINDIR, SINDIR 1029bcopy_4: 1030 mov DINDIR, SINDIR 1031bcopy_3: 1032 mov DINDIR, SINDIR 1033 mov DINDIR, SINDIR 1034 mov DINDIR, SINDIR ret 1035 1036dma_scb: 1037 /* 1038 * SCB index is in SINDEX. Determine the physical address in 1039 * the host where this SCB is located and load HADDR with it. 1040 */ 1041 shr DINDEX, SINDEX, 3 1042 shl A, SINDEX, 5 1043 add HADDR0, A, HSCB_ADDR0 1044 mov A, DINDEX 1045 adc HADDR1, A, HSCB_ADDR1 1046 clr A 1047 adc HADDR2, A, HSCB_ADDR2 1048 adc HADDR3, A, HSCB_ADDR3 1049 /* Setup Count */ 1050 mvi HCNT0, 28 1051 clr HCNT1 1052 clr HCNT2 1053 mov DFCNTRL, DMAPARAMS 1054 test DMAPARAMS, DIRECTION jnz dma_scb_fromhost 1055 /* Fill it with the SCB data */ 1056 call copy_scb_tofifo 1057 mvi DFCNTRL, 0xa /* HDMAEN | FIFOFLUSH */ 1058dma_scb_fromhost: 1059 call dma_finish 1060 /* If we were putting the SCB, we are done */ 1061 test DMAPARAMS, DIRECTION jz return 1062 mvi SCBARRAY call dfdat_in_7 1063 call dfdat_in_7_continued 1064 call dfdat_in_7_continued 1065 jmp dfdat_in_7_continued 1066dfdat_in_7: 1067 mov DINDEX,SINDEX 1068dfdat_in_7_continued: 1069 mov DINDIR,DFDAT 1070 mov DINDIR,DFDAT 1071 mov DINDIR,DFDAT 1072 mov DINDIR,DFDAT 1073 mov DINDIR,DFDAT 1074 mov DINDIR,DFDAT 1075 mov DINDIR,DFDAT ret 1076 1077copy_scb_tofifo: 1078 mvi SCBARRAY call dfdat_out_7 1079 call dfdat_out_7 1080 call dfdat_out_7 1081dfdat_out_7: 1082 mov DFDAT,SINDIR 1083 mov DFDAT,SINDIR 1084 mov DFDAT,SINDIR 1085 mov DFDAT,SINDIR 1086 mov DFDAT,SINDIR 1087 mov DFDAT,SINDIR 1088 mov DFDAT,SINDIR ret 1089 1090/* 1091 * Wait for DMA from host memory to data FIFO to complete, then disable 1092 * DMA and wait for it to acknowledge that it's off. 1093 */ 1094dma_finish: 1095 test DFSTATUS,HDONE jz dma_finish 1096 /* Turn off DMA preserving WIDEODD */ 1097 and DFCNTRL,WIDEODD 1098dma_finish2: 1099 test DFCNTRL,HDMAENACK jnz dma_finish2 1100 ret 1101 1102index_untagged_scb: 1103 mov DINDEX, SINDEX 1104 shr DINDEX, 4 1105 and DINDEX, 0x03 /* Bottom two bits of tid */ 1106 add DINDEX, SCB_ACTIVE0 1107 shr A, SINDEX, 6 /* Target ID divided by 4 */ 1108 test SINDEX, SELBUSB jz index_untagged_scb2 1109 add A, 2 /* Add 2 positions */ 1110index_untagged_scb2: 1111 mov SCBPTR, A /* 1112 * Select the SCB with this 1113 * target's information. 1114 */ 1115 mov SINDEX, DINDEX ret 1116 1117 1118get_free_or_disc_scb: 1119 cmp FREE_SCBH, SCB_LIST_NULL jne dequeue_free_scb 1120 cmp DISCONNECTED_SCBH, SCB_LIST_NULL jne dequeue_disc_scb 1121return_error: 1122 mvi SINDEX, SCB_LIST_NULL ret 1123dequeue_disc_scb: 1124 mov SCBPTR, DISCONNECTED_SCBH 1125/* 1126 * If we have a residual, then we are in the middle of some I/O 1127 * and we have to send this SCB back up to the kernel so that the 1128 * saved data pointers and residual information isn't lost. 1129 */ 1130 test SCB_RESID_SGCNT,0xff jz unlink_disc_scb 1131 mvi DMAPARAMS, 0x9 /* HDMAEN | FIFORESET*/ 1132 mov SCB_TAG call dma_scb 1133unlink_disc_scb: 1134 /* jmp instead of call since we want to return anyway */ 1135 mov SCBPTR jmp rem_scb_from_disc_list 1136dequeue_free_scb: 1137 mov SCBPTR, FREE_SCBH 1138 mov FREE_SCBH, SCB_NEXT ret 1139 1140add_scb_to_free_list: 1141 mov SCB_NEXT, FREE_SCBH 1142 mov FREE_SCBH, SCBPTR ret 1143 1144add_scb_to_disc_list: 1145/* 1146 * Link this SCB into the DISCONNECTED list. This list holds the 1147 * candidates for paging out an SCB if one is needed for a new command. 1148 * Modifying the disconnected list is a critical(pause dissabled) section. 1149 */ 1150 mvi SCB_PREV, SCB_LIST_NULL 1151 mov SCB_NEXT, DISCONNECTED_SCBH 1152 mov DISCONNECTED_SCBH, SCBPTR 1153 cmp SCB_NEXT,SCB_LIST_NULL je return 1154 mov SCBPTR,SCB_NEXT 1155 mov SCB_PREV,DISCONNECTED_SCBH 1156 mov SCBPTR,DISCONNECTED_SCBH ret 1157 1158