aic7xxx.seq revision 19803
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 1.48 1996/11/11 05:16:36 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/* 86 * We jump to start after every bus free. 87 */ 88start: 89 and FLAGS,0x07 /* clear target specific flags */ 90 mvi SCSISEQ,ENRSELI /* Always allow reselection */ 91 clr SCSIRATE /* 92 * We don't know the target we will 93 * connect to, so default to narrow 94 * transfers to avoid parity problems. 95 */ 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 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 mov SAVED_SCBPTR, SCBPTR 156 mov SCB_TCL call index_untagged_scb 157 mov ARG_1, SINDIR /* 158 * ARG_1 should 159 * now have the SCB ID of 160 * any active, non-tagged, 161 * command for this target. 162 */ 163 cmp ARG_1, SCB_LIST_NULL je make_busy 164 test FLAGS, PAGESCBS jz simple_busy_link 165 /* 166 * Put this SCB back onto the free list. It 167 * may be necessary to satisfy the search for 168 * the active SCB. 169 */ 170 mov SCBPTR, SAVED_SCBPTR 171 call add_scb_to_free_list 172 /* Find the active SCB */ 173 mov ALLZEROS call findSCB 174 /* 175 * If we couldn't find it, tell the kernel. This should 176 * only happen if the parent SCB was aborted and this 177 * one was already here at the time of the abort. 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 jmp poll_for_work 187simple_busy_link: 188 mov SCBPTR, ARG_1 189 mov SCB_LINKED_NEXT, CUR_SCBID 190 jmp poll_for_work 191make_busy: 192 mov DINDIR, CUR_SCBID 193 mov SCBPTR, SAVED_SCBPTR 194 195start_scb: 196 /* 197 * Place us on the waiting list in case our selection 198 * doesn't win during bus arbitration. 199 */ 200 mov SCB_NEXT,WAITING_SCBH 201 mov WAITING_SCBH, SCBPTR 202start_scb2: 203 and SINDEX,0xf7,SBLKCTL /* Clear the channel select bit */ 204 and A,0x08,SCB_TCL /* Get new channel bit */ 205 or SINDEX,A 206 mov SBLKCTL,SINDEX /* select channel */ 207 mov SCB_TCL call initialize_scsiid 208 209/* 210 * Enable selection phase as an initiator, and do automatic ATN 211 * after the selection. We do this now so that we can overlap the 212 * rest of our work to set up this target with the arbitration and 213 * selection bus phases. 214 */ 215start_selection: 216 mvi SCSISEQ,0x58 /* ENSELO|ENAUTOATNO|ENRSELI */ 217 218/* 219 * As soon as we get a successful selection, the target should go 220 * into the message out phase since we have ATN asserted. Prepare 221 * the message to send. 222 * 223 * Messages are stored in scratch RAM starting with a length byte 224 * followed by the message itself. 225 */ 226 227mk_identify: 228 and MSG0,0x7,SCB_TCL /* lun */ 229 and A,DISCENB,SCB_CONTROL /* mask off disconnect privledge */ 230 or MSG0,A /* or in disconnect privledge */ 231 or MSG0,MSG_IDENTIFYFLAG 232 mvi MSG_LEN, 1 233 234/* 235 * Send a tag message if TAG_ENB is set in the SCB control block. 236 * Use SCB_TAG (the position in the kernel's SCB array) as the tag value. 237 */ 238mk_tag: 239 test SCB_CONTROL,TAG_ENB jz mk_message 240 and MSG1,0x23,SCB_CONTROL 241 mov MSG2,SCB_TAG 242 add MSG_LEN,2 /* update message length */ 243 244/* 245 * Interrupt the driver, and allow it to tweak the message buffer 246 * if it asks. 247 */ 248mk_message: 249 test SCB_CONTROL,MK_MESSAGE jz wait_for_selection 250 251 mvi INTSTAT,AWAITING_MSG 252 253wait_for_selection: 254 test SSTAT0,SELDO jnz select 255 test SSTAT0,SELDI jz wait_for_selection 256 257/* 258 * Reselection has been initiated by a target. Make a note that we've been 259 * reselected, but haven't seen an IDENTIFY message from the target yet. 260 */ 261reselect: 262 clr MSG_LEN /* Don't have anything in the mesg buffer */ 263 mov SELID call initialize_scsiid 264 or FLAGS,RESELECTED 265 jmp select2 266 267/* 268 * After the selection, remove this SCB from the "waiting SCB" 269 * list. This is achieved by simply moving our "next" pointer into 270 * WAITING_SCBH. Our next pointer will be set to null the next time this 271 * SCB is used, so don't bother with it now. 272 */ 273select: 274 mov WAITING_SCBH,SCB_NEXT 275select2: 276/* 277 * Initialize SCSIRATE with the appropriate value for this target. 278 * The SCSIRATE settings for each target are stored in an array 279 * based at TARG_SCRATCH. 280 */ 281ndx_dtr: 282 shr A,SCSIID,4 283 test SBLKCTL,SELBUSB jz ndx_dtr_2 284 or SAVED_TCL, SELBUSB /* Add the channel bit while we're here */ 285 or A,0x08 /* Channel B entries add 8 */ 286ndx_dtr_2: 287 add SINDEX,TARG_SCRATCH,A 288 mov SCSIRATE,SINDIR 289 290/* 291 * Initialize Ultra mode setting and clear the SCSI channel. 292 */ 293ultra: 294 and DINDEX,0xdf,SXFRCTL0 /* default to Ultra disabled */ 295 /* 296 * Set CLRCHN here before the target has entered a data transfer mode - 297 * with synchronous SCSI, if you do it later, you blow away some 298 * data in the SCSI FIFO that the target has already sent to you. 299 */ 300 or DINDEX, CLRCHN 301 mvi SINDEX, ULTRA_ENB_B 302 test SCSIID, 0x80 jnz ultra_2 /* Target ID > 7 */ 303 test SBLKCTL, SELBUSB jnz ultra_2 /* Second channel device */ 304 dec SINDEX 305ultra_2: 306 mov FUNCTION1,SCSIID 307 mov A,FUNCTION1 308 test SINDIR, A jz set_sxfrctl0 309 or DINDEX, ULTRAEN 310 311set_sxfrctl0: 312 mov SXFRCTL0,DINDEX 313 314 mvi SCSISEQ,ENAUTOATNP /* 315 * ATN on parity errors 316 * for "in" phases 317 */ 318 mvi CLRSINT1,CLRBUSFREE 319 mvi CLRSINT0,0x60 /* CLRSELDI|CLRSELDO */ 320/* 321 * Main loop for information transfer phases. If BSY is false, then 322 * we have a bus free condition, expected or not. Otherwise, wait 323 * for the target to assert REQ before checking MSG, C/D and I/O 324 * for the bus phase. 325 * 326 */ 327ITloop: 328 test SSTAT1,BUSFREE jnz p_busfree 329 test SSTAT1,REQINIT jz ITloop 330 331 and A,PHASE_MASK,SCSISIGI 332 mov LASTPHASE,A 333 mov SCSISIGO,A 334 335 cmp ALLZEROS,A je p_dataout 336 cmp A,P_DATAIN je p_datain 337 cmp A,P_COMMAND je p_command 338 cmp A,P_MESGOUT je p_mesgout 339 cmp A,P_STATUS je p_status 340 cmp A,P_MESGIN je p_mesgin 341 342 mvi INTSTAT,BAD_PHASE /* unknown phase - signal driver */ 343 jmp ITloop /* Try reading the bus again. */ 344 345p_dataout: 346 mvi DMAPARAMS,0x7d /* 347 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 348 * DIRECTION|FIFORESET 349 */ 350 jmp data_phase_init 351 352/* 353 * If we re-enter the data phase after going through another phase, the 354 * STCNT may have been cleared, so restore it from the residual field. 355 */ 356data_phase_reinit: 357 mvi DINDEX, STCNT0 358 mvi SCB_RESID_DCNT0 call bcopy_3 359 jmp data_phase_loop 360 361p_datain: 362 mvi DMAPARAMS,0x79 /* 363 * WIDEODD|SCSIEN|SDMAEN|HDMAEN| 364 * !DIRECTION|FIFORESET 365 */ 366data_phase_init: 367 call assert /* 368 * Ensure entering a data 369 * phase is okay - seen identify, etc. 370 */ 371 372 test FLAGS, DPHASE jnz data_phase_reinit 373 374 /* 375 * Initialize the DMA address and counter from the SCB. 376 * Also set SG_COUNT and SG_NEXT in memory since we cannot 377 * modify the values in the SCB itself until we see a 378 * save data pointers message. 379 */ 380 mvi DINDEX, HADDR0 381 mvi SCB_DATAPTR call bcopy_7 382 383 call set_stcnt_from_hcnt 384 385 mov SG_COUNT,SCB_SGCOUNT 386 387 mvi DINDEX, SG_NEXT 388 mvi SCB_SGPTR call bcopy_4 389 390 /* We have seen a data phase */ 391 or FLAGS, DPHASE 392 393data_phase_loop: 394/* Guard against overruns */ 395 test SG_COUNT, 0xff jnz data_phase_inbounds 396/* 397 * Turn on 'Bit Bucket' mode, set the transfer count to 398 * 16meg and let the target run until it changes phase. 399 * When the transfer completes, notify the host that we 400 * had an overrun. 401 */ 402 or SXFRCTL1,BITBUCKET 403 mvi STCNT0,0xff 404 mvi STCNT1,0xff 405 mvi STCNT2,0xff 406 407data_phase_inbounds: 408/* If we are the last SG block, ensure wideodd is off. */ 409 cmp SG_COUNT,0x01 jne data_phase_wideodd 410 and DMAPARAMS, 0xbf /* Turn off WIDEODD */ 411data_phase_wideodd: 412 mov DMAPARAMS call dma 413 414/* Go tell the host about any overruns */ 415 test SXFRCTL1,BITBUCKET jnz data_phase_overrun 416 417/* Exit if we had an underrun */ 418 test SSTAT0,SDONE jz data_phase_finish /* underrun STCNT != 0 */ 419 420/* 421 * Advance the scatter-gather pointers if needed 422 */ 423sg_advance: 424 dec SG_COUNT /* one less segment to go */ 425 426 test SG_COUNT, 0xff jz data_phase_finish /* Are we done? */ 427 428 clr A /* add sizeof(struct scatter) */ 429 add SG_NEXT0,SG_SIZEOF,SG_NEXT0 430 adc SG_NEXT1,A,SG_NEXT1 431 432/* 433 * Load a struct scatter and set up the data address and length. 434 * If the working value of the SG count is nonzero, then 435 * we need to load a new set of values. 436 * 437 * This, like all DMA's, assumes little-endian host data storage. 438 */ 439sg_load: 440 clr HCNT2 441 clr HCNT1 442 mvi HCNT0,SG_SIZEOF 443 444 mvi DINDEX, HADDR0 445 mvi SG_NEXT0 call bcopy_4 446 447 or DFCNTRL,0xd /* HDMAEN|DIRECTION|FIFORESET */ 448 449 call dma_finish 450 451/* 452 * Copy data from FIFO into SCB data pointer and data count. This assumes 453 * that the SG segments are of the form: 454 * 455 * struct ahc_dma_seg { 456 * u_int32_t addr; four bytes, little-endian order 457 * u_int32_t len; four bytes, little endian order 458 * }; 459 */ 460 mvi HADDR0 call dfdat_in_7 461 462/* Load STCNT as well. It is a mirror of HCNT */ 463 call set_stcnt_from_hcnt 464 test SSTAT1,PHASEMIS jz data_phase_loop 465 466data_phase_finish: 467/* 468 * After a DMA finishes, save the SG and STCNT residuals back into the SCB 469 * We use STCNT instead of HCNT, since it's a reflection of how many bytes 470 * were transferred on the SCSI (as opposed to the host) bus. 471 */ 472 mov SCB_RESID_DCNT0,STCNT0 473 mov SCB_RESID_DCNT1,STCNT1 474 mov SCB_RESID_DCNT2,STCNT2 475 mov SCB_RESID_SGCNT, SG_COUNT 476 jmp ITloop 477 478data_phase_overrun: 479/* 480 * Turn off BITBUCKET mode and notify the host 481 */ 482 and SXFRCTL1,0x7f /* ~BITBUCKET */ 483 mvi INTSTAT,DATA_OVERRUN 484 jmp ITloop 485 486/* 487 * Command phase. Set up the DMA registers and let 'er rip. 488 */ 489p_command: 490 call assert 491 492/* 493 * Load HADDR and HCNT. 494 */ 495 mvi DINDEX, HADDR0 496 mvi SCB_CMDPTR call bcopy_5 497 clr HCNT1 498 clr HCNT2 499 500 call set_stcnt_from_hcnt 501 502 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 503 # DIRECTION|FIFORESET 504 jmp ITloop 505 506/* 507 * Status phase. Wait for the data byte to appear, then read it 508 * and store it into the SCB. 509 */ 510p_status: 511 call assert 512 513 mvi SCB_TARGET_STATUS call inb_first 514 jmp mesgin_done 515 516/* 517 * Message out phase. If there is not an active message, but the target 518 * took us into this phase anyway, build a no-op message and send it. 519 */ 520p_mesgout: 521 test MSG_LEN, 0xff jnz p_mesgout_start 522 mvi MSG_NOOP call mk_mesg /* build NOP message */ 523p_mesgout_start: 524/* 525 * Set up automatic PIO transfer from MSG0. Bit 3 in 526 * SXFRCTL0 (SPIOEN) is already on. 527 */ 528 mvi SINDEX,MSG0 529 mov DINDEX,MSG_LEN 530 531/* 532 * When target asks for a byte, drop ATN if it's the last one in 533 * the message. Otherwise, keep going until the message is exhausted. 534 * 535 * Keep an eye out for a phase change, in case the target issues 536 * a MESSAGE REJECT. 537 */ 538p_mesgout_loop: 539 test SSTAT1,REQINIT jz p_mesgout_loop 540 test SSTAT1,PHASEMIS jnz p_mesgout_phasemis 541 cmp DINDEX,1 jne p_mesgout_outb /* last byte? */ 542 mvi CLRSINT1,CLRATNO /* drop ATN */ 543p_mesgout_outb: 544 test SSTAT0, SPIORDY jz p_mesgout_outb 545 dec DINDEX 546 mvi CLRSINT1, CLRREQINIT 547 mov SCSIDATL,SINDIR 548 549p_mesgout4: 550 test DINDEX,0xff jnz p_mesgout_loop 551 552/* 553 * If the next bus phase after ATN drops is a message out, it means 554 * that the target is requesting that the last message(s) be resent. 555 */ 556p_mesgout_snoop: 557 test SSTAT1,BUSFREE jnz p_mesgout_done 558 test SSTAT1,REQINIT jz p_mesgout_snoop 559 560 test SSTAT1,PHASEMIS jnz p_mesgout_done 561 562 or SCSISIGO,ATNO /* turn on ATNO */ 563 564 jmp ITloop 565 566p_mesgout_phasemis: 567 mvi CLRSINT1,CLRATNO /* Be sure to turn ATNO off */ 568p_mesgout_done: 569 clr MSG_LEN /* no active msg */ 570 jmp ITloop 571 572/* 573 * Message in phase. Bytes are read using Automatic PIO mode. 574 */ 575p_mesgin: 576 mvi A call inb_first /* read the 1st message byte */ 577 mov REJBYTE,A /* save it for the driver */ 578 579 test A,MSG_IDENTIFYFLAG jnz mesgin_identify 580 cmp A,MSG_DISCONNECT je mesgin_disconnect 581 cmp A,MSG_SAVEDATAPOINTER je mesgin_sdptrs 582 cmp ALLZEROS,A je mesgin_complete 583 cmp A,MSG_RESTOREPOINTERS je mesgin_rdptrs 584 cmp A,MSG_EXTENDED je mesgin_extended 585 cmp A,MSG_MESSAGE_REJECT je mesgin_reject 586 587rej_mesgin: 588/* 589 * We have no idea what this message in is, so we issue a message reject 590 * and hope for the best. In any case, rejection should be a rare 591 * occurrence - signal the driver when it happens. 592 */ 593 mvi INTSTAT,SEND_REJECT /* let driver know */ 594 595 mvi MSG_MESSAGE_REJECT call mk_mesg 596 597mesgin_done: 598 call inb_last /*ack & turn auto PIO back on*/ 599 jmp ITloop 600 601 602mesgin_complete: 603/* 604 * We got a "command complete" message, so put the SCB_TAG into the QOUTFIFO, 605 * and trigger a completion interrupt. Before doing so, check to see if there 606 * is a residual or the status byte is something other than NO_ERROR (0). In 607 * either of these conditions, we upload the SCB back to the host so it can 608 * process this information. In the case of a non zero status byte, we 609 * additionally interrupt the kernel driver synchronously, allowing it to 610 * decide if sense should be retrieved. If the kernel driver wishes to request 611 * sense, it will fill the kernel SCB with a request sense command and set 612 * RETURN_1 to SEND_SENSE. If RETURN_1 is set to SEND_SENSE we redownload 613 * the SCB, and process it as the next command by adding it to the waiting list. 614 * If the kernel driver does not wish to request sense, it need only clear 615 * RETURN_1, and the command is allowed to complete normally. We don't bother 616 * to post to the QOUTFIFO in the error cases since it would require extra 617 * work in the kernel driver to ensure that the entry was removed before the 618 * command complete code tried processing it. 619 */ 620 621/* 622 * First check for residuals 623 */ 624 test SCB_RESID_SGCNT,0xff jnz upload_scb 625 test SCB_TARGET_STATUS,0xff jz status_ok /* Good Status? */ 626upload_scb: 627 mvi DMAPARAMS, 0x9 /* HDMAEN | FIFORESET*/ 628 mov SCB_TAG call dma_scb 629check_status: 630 test SCB_TARGET_STATUS,0xff jz status_ok /* Just a residual? */ 631 mvi INTSTAT,BAD_STATUS /* let driver know */ 632 cmp RETURN_1, SEND_SENSE jne status_ok 633 /* This SCB becomes the next to execute as it will retrieve sense */ 634 mov SCB_LINKED_NEXT, SCB_TAG 635 jmp dma_next_scb 636 637status_ok: 638/* First, mark this target as free. */ 639 test SCB_CONTROL,TAG_ENB jnz test_immediate /* 640 * Tagged commands 641 * don't busy the 642 * target. 643 */ 644 mov SAVED_SCBPTR, SCBPTR 645 mov SAVED_LINKPTR, SCB_LINKED_NEXT 646 mov SCB_TCL call index_untagged_scb 647 mov DINDIR, SAVED_LINKPTR 648 mov SCBPTR, SAVED_SCBPTR 649 650test_immediate: 651 test SCB_CMDLEN,0xff jnz complete /* Immediate message complete */ 652/* 653 * Pause the sequencer until the driver gets around to handling the command 654 * complete. This is so that any action that might require carefull timing 655 * with the completion of this command can occur. 656 */ 657 mvi INTSTAT,IMMEDDONE 658 jmp dma_next_scb 659complete: 660 test FLAGS, PAGESCBS jz complete_post 661 mov A, QFULLCNT 662complete_poll: 663 cmp QOUTQCNT, A je complete_poll 664 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 665 inc QOUTQCNT 666complete_post: 667 /* Post the SCB and issue an interrupt */ 668 mov QOUTFIFO,SCB_TAG 669 mvi SEQCTL,0x10 /* FASTMODE */ 670 mvi INTSTAT,CMDCMPLT 671 672dma_next_scb: 673 cmp SCB_LINKED_NEXT, SCB_LIST_NULL je mesgin_done 674 test FLAGS, PAGESCBS jnz dma_next_scb2 675 /* Only DMA on top of ourselves if we are the SCB to download */ 676 mov A, SCB_LINKED_NEXT 677 cmp SCB_TAG, A je dma_next_scb2 678 mov SCBPTR, A 679 jmp add_to_waiting_list 680dma_next_scb2: 681 mvi DMAPARAMS, 0xd /* HDMAEN|DIRECTION|FIFORESET */ 682 mov SCB_LINKED_NEXT call dma_scb 683add_to_waiting_list: 684 mov SCB_NEXT,WAITING_SCBH 685 mov WAITING_SCBH, SCBPTR 686 or FLAGS, SCB_LISTED 687 jmp mesgin_done 688 689/* 690 * Is it an extended message? Copy the message to our message buffer and 691 * notify the host. The host will tell us whether to reject this message, 692 * respond to it with the message that the host placed in our message buffer, 693 * or simply to do nothing. 694 */ 695mesgin_extended: 696 mvi MSGIN_EXT_LEN call inb_next 697 mov A, MSGIN_EXT_LEN 698mesgin_extended_loop: 699 mov DINDEX call inb_next 700 dec A 701 cmp DINDEX, MSGIN_EXT_LASTBYTE jne mesgin_extended_loop_test 702 dec DINDEX /* dump by repeatedly filling the last byte */ 703mesgin_extended_loop_test: 704 test A, 0xFF jnz mesgin_extended_loop 705mesgin_extended_intr: 706 mvi INTSTAT,EXTENDED_MSG /* let driver know */ 707 cmp RETURN_1,SEND_REJ je rej_mesgin 708 cmp RETURN_1,SEND_MSG jne mesgin_done 709/* The kernel has setup a message to be sent */ 710 or SCSISIGO,ATNO /* turn on ATNO */ 711 jmp mesgin_done 712 713/* 714 * Is it a disconnect message? Set a flag in the SCB to remind us 715 * and await the bus going free. 716 */ 717mesgin_disconnect: 718 or SCB_CONTROL,DISCONNECTED 719 test FLAGS, PAGESCBS jz mesgin_done 720 call add_scb_to_disc_list 721 or FLAGS, SCB_LISTED 722 jmp mesgin_done 723 724/* 725 * Save data pointers message: 726 * Copying RAM values back to SCB, for Save Data Pointers message, but 727 * only if we've actually been into a data phase to change them. This 728 * protects against bogus data in scratch ram and the residual counts 729 * since they are only initialized when we go into data_in or data_out. 730 */ 731mesgin_sdptrs: 732 test FLAGS, DPHASE jz mesgin_done 733 mov SCB_SGCOUNT,SG_COUNT 734 735 /* The SCB SGPTR becomes the next one we'll download */ 736 mvi DINDEX, SCB_SGPTR 737 mvi SG_NEXT0 call bcopy_4 738 739 /* The SCB DATAPTR0 becomes the current SHADDR */ 740 mvi DINDEX, SCB_DATAPTR0 741 mvi SHADDR0 call bcopy_4 742 743/* 744 * Use the residual number since STCNT is corrupted by any message transfer. 745 */ 746 mvi SCB_RESID_DCNT0 call bcopy_3 747 748 jmp mesgin_done 749 750/* 751 * Restore pointers message? Data pointers are recopied from the 752 * SCB anytime we enter a data phase for the first time, so all 753 * we need to do is clear the DPHASE flag and let the data phase 754 * code do the rest. 755 */ 756mesgin_rdptrs: 757 and FLAGS,0xef /* 758 * !DPHASE we'll reload them 759 * the next time through 760 */ 761 jmp mesgin_done 762 763/* 764 * Identify message? For a reconnecting target, this tells us the lun 765 * that the reconnection is for - find the correct SCB and switch to it, 766 * clearing the "disconnected" bit so we don't "find" it by accident later. 767 */ 768mesgin_identify: 769 test A,0x78 jnz rej_mesgin /*!DiscPriv|!LUNTAR|!Reserved*/ 770 and A,0x07 /* lun in lower three bits */ 771 or SAVED_TCL,A /* SAVED_TCL should be complete now */ 772 call inb_last /* ACK */ 773 774/* 775 * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message. 776 * If we get one, we use the tag returned to switch to find the proper 777 * SCB. With SCB paging, this requires using findSCB for both tagged 778 * and non-tagged transactions since the SCB may exist in any slot. 779 * If we're not using SCB paging, we can use the tag as the direct 780 * index to the SCB. 781 */ 782 mvi ARG_1,SCB_LIST_NULL /* Default to no-tag */ 783snoop_tag_loop: 784 test SSTAT1,BUSFREE jnz use_findSCB 785 test SSTAT1,REQINIT jz snoop_tag_loop 786 test SSTAT1,PHASEMIS jnz use_findSCB 787 mvi A call inb_first 788 cmp A,MSG_SIMPLE_Q_TAG jne use_findSCB 789get_tag: 790 or FLAGS, TAGGED_SCB 791 mvi ARG_1 call inb_next /* tag value */ 792/* 793 * See if the tag is in range. The tag is < SCBCOUNT if we add 794 * the complement of SCBCOUNT to the incomming tag and there is 795 * no carry. 796 */ 797 mov A,COMP_SCBCOUNT 798 add SINDEX,A,ARG_1 799 jc send_abort_msg 800 801/* 802 * Ensure that the SCB the tag points to is for an SCB transaction 803 * to the reconnecting target. 804 */ 805 test FLAGS, PAGESCBS jz index_by_tag 806use_findSCB: 807 mov ALLZEROS call findSCB /* Have to search */ 808 cmp SINDEX, SCB_LIST_NULL, je not_found 809setup_SCB: 810 and SCB_CONTROL,0xfb /* clear disconnect bit in SCB */ 811 or FLAGS,IDENTIFY_SEEN /* make note of IDENTIFY */ 812 test SCB_CONTROL,TAG_ENB jnz mesgin_done /* Ack Tag */ 813 jmp ITloop 814index_by_tag: 815 mov SCBPTR,ARG_1 816 mov A, SAVED_TCL 817 cmp SCB_TCL,A jne send_abort_msg 818 test SCB_CONTROL,TAG_ENB jz send_abort_msg 819 jmp setup_SCB 820 821not_found: 822 mvi INTSTAT, NO_MATCH 823send_abort_msg: 824 test FLAGS, TAGGED_SCB jnz abort_tag_msg 825 mvi MSG_ABORT call mk_mesg 826 jmp mesgin_done 827abort_tag_msg: 828 mvi MSG_ABORT_TAG call mk_mesg /* ABORT TAG message */ 829 jmp mesgin_done 830 831/* 832 * Message reject? Let the kernel driver handle this. If we have an 833 * outstanding WDTR or SDTR negotiation, assume that it's a response from 834 * the target selecting 8bit or asynchronous transfer, otherwise just ignore 835 * it since we have no clue what it pertains to. 836 */ 837mesgin_reject: 838 mvi INTSTAT, REJECT_MSG 839 jmp mesgin_done 840 841/* 842 * [ ADD MORE MESSAGE HANDLING HERE ] 843 */ 844 845/* 846 * Bus free phase. It might be useful to interrupt the device 847 * driver if we aren't expecting this. 848 */ 849p_busfree: 850 mvi LASTPHASE, P_BUSFREE 851 852/* 853 * if this is an immediate command, perform a psuedo command complete to 854 * notify the driver. 855 */ 856 test SCB_CMDLEN,0xff jz status_ok 857 test FLAGS, SCB_LISTED jnz start 858 /* 859 * This SCB didn't disconnect or have a command complete, 860 * so put it on the free queue. It was probably the 861 * result of an abort of some sort. This prevents us 862 * from "leaking" SCBs. 863 */ 864 call add_scb_to_free_list 865 jmp start 866 867/* 868 * Locking the driver out, build a one-byte message passed in SINDEX 869 * if there is no active message already. SINDEX is returned intact. 870 */ 871mk_mesg: 872 mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ 873 test MSG_LEN,0xff jz mk_mesg1 /* Should always succeed */ 874 875 /* 876 * Hmmm. For some reason the mesg buffer is in use. 877 * Tell the driver. It should look at SINDEX to find 878 * out what we wanted to use the buffer for and resolve 879 * the conflict. 880 */ 881 mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 882 mvi INTSTAT,MSG_BUFFER_BUSY 883 884mk_mesg1: 885 or SCSISIGO,ATNO /* turn on ATNO */ 886 mvi MSG_LEN,1 /* length = 1 */ 887 mov MSG0,SINDEX /* 1-byte message */ 888 mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ 889 890/* 891 * Functions to read data in Automatic PIO mode. 892 * 893 * According to Adaptec's documentation, an ACK is not sent on input from 894 * the target until SCSIDATL is read from. So we wait until SCSIDATL is 895 * latched (the usual way), then read the data byte directly off the bus 896 * using SCSIBUSL. When we have pulled the ATN line, or we just want to 897 * acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI 898 * spec guarantees that the target will hold the data byte on the bus until 899 * we send our ACK. 900 * 901 * The assumption here is that these are called in a particular sequence, 902 * and that REQ is already set when inb_first is called. inb_{first,next} 903 * use the same calling convention as inb. 904 */ 905 906inb_next: 907 call inb_last /* ACK */ 908inb_next_wait: 909 test SSTAT1, REQINIT jz inb_next_wait 910 test SSTAT1,PHASEMIS jnz mesgin_phasemis 911inb_first: 912 mov DINDEX,SINDEX 913 mov DINDIR,SCSIBUSL ret /*read byte directly from bus*/ 914inb_last: 915 mvi CLRSINT1, CLRREQINIT 916 mov NONE,SCSIDATL ret /*dummy read from latch to ACK*/ 917 918mesgin_phasemis: 919/* 920 * We expected to receive another byte, but the target changed phase 921 */ 922 mvi INTSTAT, MSGIN_PHASEMIS 923 jmp ITloop 924 925/* 926 * DMA data transfer. HADDR and HCNT must be loaded first, and 927 * SINDEX should contain the value to load DFCNTRL with - 0x3d for 928 * host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared 929 * during initialization. 930 */ 931dma: 932 mov DFCNTRL,SINDEX 933dma1: 934 test SSTAT0,DMADONE jnz dma3 935 test SSTAT1,PHASEMIS jz dma1 /* ie. underrun */ 936 937/* 938 * We will be "done" DMAing when the transfer count goes to zero, or 939 * the target changes the phase (in light of this, it makes sense that 940 * the DMA circuitry doesn't ACK when PHASEMIS is active). If we are 941 * doing a SCSI->Host transfer, the data FIFO should be flushed auto- 942 * magically on STCNT=0 or a phase change, so just wait for FIFO empty 943 * status. 944 */ 945dma3: 946 test SINDEX,DIRECTION jnz dma5 947dma4: 948 test DFSTATUS,FIFOEMP jz dma4 949 950/* 951 * Now shut the DMA enables off and make sure that the DMA enables are 952 * actually off first lest we get an ILLSADDR. 953 */ 954dma5: 955 /* disable DMA, but maintain WIDEODD */ 956 and DFCNTRL,WIDEODD 957dma6: 958 test DFCNTRL,0x38 jnz dma6 /* SCSIENACK|SDMAENACK|HDMAENACK */ 959return: 960 ret 961 962/* 963 * Common SCSI initialization for selection and reselection. Expects 964 * the target SCSI ID to be in the upper four bits of SINDEX, and A's 965 * contents are stomped on return. 966 */ 967initialize_scsiid: 968 and SINDEX,0xf0 /* Get target ID */ 969 mov SAVED_TCL, SINDEX /* Update the target portion of this */ 970 and A,0x0f,SCSIID 971 or SINDEX,A 972 mov SCSIID,SINDEX ret 973 974/* 975 * Assert that if we've been reselected, then we've seen an IDENTIFY 976 * message. 977 */ 978assert: 979 test FLAGS,RESELECTED jz return /* reselected? */ 980 test FLAGS,IDENTIFY_SEEN jnz return /* seen IDENTIFY? */ 981 982 mvi INTSTAT,NO_IDENT ret /* no - tell the kernel */ 983 984/* 985 * Locate a disconnected SCB either by SAVED_TCL (ARG_1 is SCB_LIST_NULL) 986 * or by the SCBIDn ARG_1. The search begins at the SCB index passed in 987 * via SINDEX. If the SCB cannot be found, SINDEX will be SCB_LIST_NULL, 988 * otherwise, SCBPTR is set to the proper SCB. 989 */ 990findSCB: 991 mov SCBPTR,SINDEX /* switch to next SCB */ 992 test SCB_CONTROL,DISCONNECTED jz findSCB1 /*should be disconnected*/ 993 cmp ARG_1, SCB_LIST_NULL jne findBySCBID 994 mov A, SAVED_TCL 995 cmp SCB_TCL,A je foundSCB /* target ID/channel/lun match? */ 996findSCB1: 997 inc SINDEX 998 mov A,SCBCOUNT 999 cmp SINDEX,A jne findSCB 1000/* 1001 * We didn't find it. If we're paging, pull an SCB and DMA down the 1002 * one we want. If we aren't paging or the SCB we dma down has the 1003 * abort flag set, return not found. 1004 */ 1005 test FLAGS, PAGESCBS jz find_error 1006 mov ALLZEROS call get_free_or_disc_scb 1007 cmp ARG_1, SCB_LIST_NULL jne find_dma_scb 1008 mov SAVED_TCL call index_untagged_scb 1009 mov ARG_1, SINDIR /* SCBID of SCB to fetch */ 1010find_dma_scb: 1011 mvi DMAPARAMS, 0xd /* HDMAEN|DIRECTION|FIFORESET */ 1012 mov ARG_1 call dma_scb 1013 test SCB_CONTROL, ABORT_SCB jz return 1014find_error: 1015 mvi SINDEX, SCB_LIST_NULL ret 1016findBySCBID: 1017 mov A, ARG_1 /* Tag passed in ARG_1 */ 1018 cmp SCB_TAG,A jne findSCB1 /* Found it? */ 1019foundSCB: 1020 test SCB_CONTROL, ABORT_SCB jnz find_error 1021 test FLAGS,PAGESCBS jz return 1022rem_scb_from_disc_list: 1023/* Remove this SCB from the disconnection list */ 1024 cmp SCB_NEXT,SCB_LIST_NULL je unlink_prev 1025 mov SAVED_LINKPTR, SCB_PREV 1026 mov SCBPTR, SCB_NEXT 1027 mov SCB_PREV, SAVED_LINKPTR 1028 mov SCBPTR, SINDEX 1029unlink_prev: 1030 cmp SCB_PREV,SCB_LIST_NULL je rHead/* At the head of the list */ 1031 mov SAVED_LINKPTR, SCB_NEXT 1032 mov SCBPTR, SCB_PREV 1033 mov SCB_NEXT, SAVED_LINKPTR 1034 mov SCBPTR, SINDEX ret 1035rHead: 1036 mov DISCONNECTED_SCBH,SCB_NEXT ret 1037 1038set_stcnt_from_hcnt: 1039 mov STCNT0, HCNT0 1040 mov STCNT1, HCNT1 1041 mov STCNT2, HCNT2 ret 1042 1043bcopy_7: 1044 mov DINDIR, SINDIR 1045 mov DINDIR, SINDIR 1046bcopy_5: 1047 mov DINDIR, SINDIR 1048bcopy_4: 1049 mov DINDIR, SINDIR 1050bcopy_3: 1051 mov DINDIR, SINDIR 1052 mov DINDIR, SINDIR 1053 mov DINDIR, SINDIR ret 1054 1055dma_scb: 1056 /* 1057 * SCB index is in SINDEX. Determine the physical address in 1058 * the host where this SCB is located and load HADDR with it. 1059 */ 1060 shr DINDEX, SINDEX, 3 1061 shl A, SINDEX, 5 1062 add HADDR0, A, HSCB_ADDR0 1063 mov A, DINDEX 1064 adc HADDR1, A, HSCB_ADDR1 1065 clr A 1066 adc HADDR2, A, HSCB_ADDR2 1067 adc HADDR3, A, HSCB_ADDR3 1068 /* Setup Count */ 1069 mvi HCNT0, 28 1070 clr HCNT1 1071 clr HCNT2 1072 mov DFCNTRL, DMAPARAMS 1073 test DMAPARAMS, DIRECTION jnz dma_scb_fromhost 1074 /* Fill it with the SCB data */ 1075 call copy_scb_tofifo 1076 mvi DFCNTRL, 0xa /* HDMAEN | FIFOFLUSH */ 1077dma_scb_fromhost: 1078 call dma_finish 1079 /* If we were putting the SCB, we are done */ 1080 test DMAPARAMS, DIRECTION jz return 1081 mvi SCBARRAY call dfdat_in_7 1082 call dfdat_in_7_continued 1083 call dfdat_in_7_continued 1084 jmp dfdat_in_7_continued 1085dfdat_in_7: 1086 mov DINDEX,SINDEX 1087dfdat_in_7_continued: 1088 mov DINDIR,DFDAT 1089 mov DINDIR,DFDAT 1090 mov DINDIR,DFDAT 1091 mov DINDIR,DFDAT 1092 mov DINDIR,DFDAT 1093 mov DINDIR,DFDAT 1094 mov DINDIR,DFDAT ret 1095 1096copy_scb_tofifo: 1097 mvi SCBARRAY call dfdat_out_7 1098 call dfdat_out_7 1099 call dfdat_out_7 1100dfdat_out_7: 1101 mov DFDAT,SINDIR 1102 mov DFDAT,SINDIR 1103 mov DFDAT,SINDIR 1104 mov DFDAT,SINDIR 1105 mov DFDAT,SINDIR 1106 mov DFDAT,SINDIR 1107 mov DFDAT,SINDIR ret 1108 1109/* 1110 * Wait for DMA from host memory to data FIFO to complete, then disable 1111 * DMA and wait for it to acknowledge that it's off. 1112 */ 1113dma_finish: 1114 test DFSTATUS,HDONE jz dma_finish 1115 /* Turn off DMA preserving WIDEODD */ 1116 and DFCNTRL,WIDEODD 1117dma_finish2: 1118 test DFCNTRL,HDMAENACK jnz dma_finish2 1119 ret 1120 1121index_untagged_scb: 1122 mov DINDEX, SINDEX 1123 shr DINDEX, 4 1124 and DINDEX, 0x03 /* Bottom two bits of tid */ 1125 add DINDEX, SCB_ACTIVE0 1126 shr A, SINDEX, 6 /* Target ID divided by 4 */ 1127 test SINDEX, SELBUSB jz index_untagged_scb2 1128 add A, 2 /* Add 2 positions */ 1129index_untagged_scb2: 1130 mov SCBPTR, A /* 1131 * Select the SCB with this 1132 * target's information. 1133 */ 1134 mov SINDEX, DINDEX ret 1135 1136 1137get_free_or_disc_scb: 1138 cmp FREE_SCBH, SCB_LIST_NULL jne dequeue_free_scb 1139 cmp DISCONNECTED_SCBH, SCB_LIST_NULL jne dequeue_disc_scb 1140return_error: 1141 mvi SINDEX, SCB_LIST_NULL ret 1142dequeue_disc_scb: 1143 mov SCBPTR, DISCONNECTED_SCBH 1144/* 1145 * If we have a residual, then we are in the middle of some I/O 1146 * and we have to send this SCB back up to the kernel so that the 1147 * saved data pointers and residual information isn't lost. 1148 */ 1149 test SCB_RESID_SGCNT,0xff jz unlink_disc_scb 1150 mvi DMAPARAMS, 0x9 /* HDMAEN | FIFORESET*/ 1151 mov SCB_TAG call dma_scb 1152unlink_disc_scb: 1153 /* jmp instead of call since we want to return anyway */ 1154 mov SCBPTR jmp rem_scb_from_disc_list 1155dequeue_free_scb: 1156 mov SCBPTR, FREE_SCBH 1157 mov FREE_SCBH, SCB_NEXT ret 1158 1159add_scb_to_free_list: 1160 mov SCB_NEXT, FREE_SCBH 1161 mov FREE_SCBH, SCBPTR ret 1162 1163add_scb_to_disc_list: 1164/* 1165 * Link this SCB into the DISCONNECTED list. This list holds the 1166 * candidates for paging out an SCB if one is needed for a new command. 1167 * Modifying the disconnected list is a critical(pause dissabled) section. 1168 */ 1169 mvi SCB_PREV, SCB_LIST_NULL 1170 mov SCB_NEXT, DISCONNECTED_SCBH 1171 mov DISCONNECTED_SCBH, SCBPTR 1172 cmp SCB_NEXT,SCB_LIST_NULL je return 1173 mov SCBPTR,SCB_NEXT 1174 mov SCB_PREV,DISCONNECTED_SCBH 1175 mov SCBPTR,DISCONNECTED_SCBH ret 1176 1177