aic7xxx.seq revision 5775
1# @(#)aic7xxx.seq 1.32 94/11/29 jda 2# 3# Adaptec 274x/284x/294x device driver for Linux and FreeBSD. 4# Copyright (c) 1994 The University of Calgary Department of Computer Science. 5# 6# This program is free software; you can redistribute it and/or modify 7# it under the terms of the GNU General Public License as published by 8# the Free Software Foundation; either version 2 of the License, or 9# (at your option) any later version. 10# 11# This program is distributed in the hope that it will be useful, 12# but WITHOUT ANY WARRANTY; without even the implied warranty of 13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14# GNU General Public License for more details. 15# 16# You should have received a copy of the GNU General Public License 17# along with this program; if not, write to the Free Software 18# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19# 20 21# FreeBSD, Twin, Wide, 2 command per target support, and other optimizations 22# provided by Justin T. Gibbs (gibbs@FreeBSD.org) 23# 24# $Id: aic7xxx.seq,v 1.5 1995/01/16 16:31:21 gibbs Exp $ 25 26VERSION AIC7XXX_SEQ_VERSION 1.5 27 28SCBMASK = 0x1f 29 30SCSISEQ = 0x00 31SXFRCTL0 = 0x01 32SXFRCTL1 = 0x02 33SCSISIGI = 0x03 34SCSISIGO = 0x03 35SCSIRATE = 0x04 36SCSIID = 0x05 37SCSIDATL = 0x06 38STCNT = 0x08 39STCNT+0 = 0x08 40STCNT+1 = 0x09 41STCNT+2 = 0x0a 42SSTAT0 = 0x0b 43CLRSINT1 = 0x0c 44SSTAT1 = 0x0c 45SIMODE1 = 0x11 46SCSIBUSL = 0x12 47SHADDR = 0x14 48SELID = 0x19 49SBLKCTL = 0x1f 50SEQCTL = 0x60 51A = 0x64 # == ACCUM 52SINDEX = 0x65 53DINDEX = 0x66 54ALLZEROS = 0x6a 55NONE = 0x6a 56SINDIR = 0x6c 57DINDIR = 0x6d 58FUNCTION1 = 0x6e 59HADDR = 0x88 60HCNT = 0x8c 61HCNT+0 = 0x8c 62HCNT+1 = 0x8d 63HCNT+2 = 0x8e 64SCBPTR = 0x90 65INTSTAT = 0x91 66DFCNTRL = 0x93 67DFSTATUS = 0x94 68DFDAT = 0x99 69QINFIFO = 0x9b 70QINCNT = 0x9c 71QOUTFIFO = 0x9d 72 73SCSICONF_A = 0x5a 74SCSICONF_B = 0x5b 75 76# The two reserved bytes at SCBARRAY+1[23] are expected to be set to 77# zero, and the reserved bit in SCBARRAY+0 is used as an internal flag 78# to indicate whether or not to reload scatter-gather parameters after 79# a disconnect. We also use bits 6 & 7 to indicate whether or not to 80# initiate SDTR or WDTR repectively when starting this command. 81# 82SCBARRAY+0 = 0xa0 83 84DISCONNECTED = 0x04 85NEEDDMA = 0x08 86SG_LOAD = 0x10 87NEEDSDTR = 0x40 88NEEDWDTR = 0x80 89 90SCBARRAY+1 = 0xa1 91SCBARRAY+2 = 0xa2 92SCBARRAY+3 = 0xa3 93SCBARRAY+4 = 0xa4 94SCBARRAY+5 = 0xa5 95SCBARRAY+6 = 0xa6 96SCBARRAY+7 = 0xa7 97SCBARRAY+8 = 0xa8 98SCBARRAY+9 = 0xa9 99SCBARRAY+10 = 0xaa 100SCBARRAY+11 = 0xab 101SCBARRAY+12 = 0xac 102SCBARRAY+13 = 0xad 103SCBARRAY+14 = 0xae 104SCBARRAY+15 = 0xaf 105SCBARRAY+16 = 0xb0 106SCBARRAY+17 = 0xb1 107SCBARRAY+18 = 0xb2 108SCBARRAY+19 = 0xb3 109SCBARRAY+20 = 0xb4 110SCBARRAY+21 = 0xb5 111SCBARRAY+22 = 0xb6 112SCBARRAY+23 = 0xb7 113SCBARRAY+24 = 0xb8 114SCBARRAY+25 = 0xb9 115SCBARRAY+26 = 0xba 116 117BAD_PHASE = 0x01 # unknown scsi bus phase 118SEND_REJECT = 0x11 # sending a message reject 119NO_IDENT = 0x21 # no IDENTIFY after reconnect 120NO_MATCH = 0x31 # no cmd match for reconnect 121MSG_SDTR = 0x41 # SDTR message recieved 122MSG_WDTR = 0x51 # WDTR message recieved 123MSG_REJECT = 0x61 # Reject message recieved 124BAD_STATUS = 0x71 # Bad status from target 125 126# The host adapter card (at least the BIOS) uses 20-2f for SCSI 127# device information, 32-33 and 5a-5f as well. As it turns out, the 128# BIOS trashes 20-2f, writing the synchronous negotiation results 129# on top of the BIOS values, so we re-use those for our per-target 130# scratchspace (actually a value that can be copied directly into 131# SCSIRATE). The kernel driver will enable synchronous negotiation 132# for all targets that have a value other than 0 in the lower four 133# bits of the target scratch space. This should work irregardless of 134# whether the bios has been installed. NEEDWDTR and NEEDSDTR are the top 135# two bits of the SCB control byte. The kernel driver will set these 136# when a WDTR or SDTR message should be sent to the target the SCB's 137# command references. 138# 139# The high bit of DROPATN is set if ATN should be dropped before the ACK 140# when outb is called. REJBYTE contains the first byte of a MESSAGE IN 141# message, so the driver can report an intelligible error if a message is 142# rejected. 143# 144# FLAGS's high bit is true if we are currently handling a reselect; 145# its next-highest bit is true ONLY IF we've seen an IDENTIFY message 146# from the reselecting target. If we haven't had IDENTIFY, then we have 147# no idea what the lun is, and we can't select the right SCB register 148# bank, so force a kernel panic if the target attempts a data in/out or 149# command phase instead of corrupting something. 150# 151# Note that SG_NEXT occupies four bytes. 152# 153SYNCNEG = 0x20 154 155DROPATN = 0x30 156REJBYTE = 0x31 157DISC_DSB_A = 0x32 158DISC_DSB_B = 0x33 159 160MSG_LEN = 0x36 161MSG_START+0 = 0x37 162MSG_START+1 = 0x38 163MSG_START+2 = 0x39 164MSG_START+3 = 0x3a 165MSG_START+4 = 0x3b 166MSG_START+5 = 0x3c 167-MSG_START+0 = 0xc9 # 2's complement of MSG_START+0 168 169ARG_1 = 0x4c # sdtr conversion args & return 170BUS_16_BIT = 0x01 171RETURN_1 = 0x4c 172 173SIGSTATE = 0x4d # value written to SCSISIGO 174 175# Linux users should use 0xc (12) for SG_SIZEOF 176SG_SIZEOF = 0x8 # sizeof(struct ahc_dma) 177#SG_SIZEOF = 0xc # sizeof(struct scatterlist) 178SCB_SIZEOF = 0x13 # sizeof SCB to DMA (19 bytes) 179 180SG_NOLOAD = 0x50 # load SG pointer/length? 181SG_COUNT = 0x51 # working value of SG count 182SG_NEXT = 0x52 # working value of SG pointer 183SG_NEXT+0 = 0x52 184SG_NEXT+1 = 0x53 185SG_NEXT+2 = 0x54 186SG_NEXT+3 = 0x55 187 188SCBCOUNT = 0x56 # the actual number of SCBs 189FLAGS = 0x57 # Device configuration flags 190TWIN_BUS = 0x01 191WIDE_BUS = 0x02 192SENSE = 0x10 193ACTIVE_MSG = 0x20 194IDENTIFY_SEEN = 0x40 195RESELECTED = 0x80 196 197ACTIVE_A = 0x58 198ACTIVE_B = 0x59 199 200# Poll QINCNT for work - the lower bits contain 201# the number of entries in the Queue In FIFO. 202# 203start: 204 test FLAGS,SENSE jnz start_sense 205start_nosense: 206 test FLAGS,TWIN_BUS jz start2 # Are we a twin channel device? 207# For fairness, we check the other bus first, since we just finished a 208# transaction on the current channel. 209 xor SBLKCTL,0x08 # Toggle to the other bus 210 test SCSISIGI,0x4 jnz reselect # BSYI 211 xor SBLKCTL,0x08 # Toggle to the original bus 212start2: 213 test SCSISIGI,0x4 jnz reselect # BSYI 214 test QINCNT,SCBMASK jz start_nosense 215 216# We have at least one queued SCB now. Set the SCB pointer 217# from the FIFO so we see the right bank of SCB registers, 218# then set SCSI options and set the initiator and target 219# SCSI IDs. 220# 221 mov SCBPTR,QINFIFO 222 223# If the control byte of this SCB has the NEEDDMA flag set, we have 224# yet to DMA it from host memory 225 226test SCBARRAY+0,NEEDDMA jz test_busy 227 clr HCNT+2 228 clr HCNT+1 229 mvi HCNT+0,SCB_SIZEOF 230 231 mvi DINDEX,HADDR 232 mvi SCBARRAY+26 call bcopy_4 233 234 mvi DFCNTRL,0xd # HDMAEN|DIRECTION|FIFORESET 235 236# Wait for DMA from host memory to data FIFO to complete, then disable 237# DMA and wait for it to acknowledge that it's off. 238# 239scb_load1: 240 test DFSTATUS,0x8 jz scb_load1 # HDONE 241 242 clr DFCNTRL # disable DMA 243scb_load2: 244 test DFCNTRL,0x8 jnz scb_load2 # HDMAENACK 245 246# Copy the SCB from the FIFO to the SCBARRAY 247 248 mov SCBARRAY+0, DFDAT 249 mov SCBARRAY+1, DFDAT 250 mov SCBARRAY+2, DFDAT 251 mov SCBARRAY+3, DFDAT 252 mov SCBARRAY+4, DFDAT 253 mov SCBARRAY+5, DFDAT 254 mov SCBARRAY+6, DFDAT 255 mov SCBARRAY+7, DFDAT 256 mov SCBARRAY+8, DFDAT 257 mov SCBARRAY+9, DFDAT 258 mov SCBARRAY+10, DFDAT 259 mov SCBARRAY+11, DFDAT 260 mov SCBARRAY+12, DFDAT 261 mov SCBARRAY+13, DFDAT 262 mov SCBARRAY+14, DFDAT 263 mov SCBARRAY+15, DFDAT 264 mov SCBARRAY+16, DFDAT 265 mov SCBARRAY+17, DFDAT 266 mov SCBARRAY+18, DFDAT 267 268# See if there is not already an active SCB for this target. This code 269# locks out on a per target basis instead of target/lun. Although this 270# is not ideal for devices that have multiple luns active at the same 271# time, it is faster than looping through all SCB's looking for active 272# commands. It may be benificial to make findscb a more general procedure 273# to see if the added cost of the search is negligible. This code also 274# assumes that the kernel driver will clear the active flags on board 275# initialization, board reset, and a target's SELTO. 276 277test_busy: 278 and FUNCTION1,0x70,SCBARRAY+1 279 mov A,FUNCTION1 280 test SCBARRAY+1,0x88 jz test_a # Id < 8 && A channel 281 282 test ACTIVE_B,A jnz requeue 283 or ACTIVE_B,A # Mark the current target as busy 284 jmp start_scb 285 286start_sense: 287# Clear the SENSE flag first, then do a normal start_scb 288 and FLAGS,0xef 289 jmp start_scb 290 291# Place the currently active back on the queue for later processing 292requeue: 293 mov QINFIFO, SCBPTR 294 jmp start_nosense 295 296test_a: 297 test ACTIVE_A,A jnz requeue 298 or ACTIVE_A,A # Mark the current target as busy 299 300start_scb: 301 or SCBARRAY+0,NEEDDMA 302 and SINDEX,0x08,SCBARRAY+1 303 and A,WIDE_BUS,FLAGS # Wide bus? 304 or SINDEX,A 305 mov SBLKCTL,SINDEX # select channel, bus width 306 mov SCBARRAY+1 call initialize 307 clr SG_NOLOAD 308 and FLAGS,0x3f # !RESELECTING 309 310# As soon as we get a successful selection, the target should go 311# into the message out phase since we have ATN asserted. Prepare 312# the message to send, locking out the device driver. If the device 313# driver hasn't beaten us with an ABORT or RESET message, then tack 314# on an SDTR negotiation if required. 315# 316# Messages are stored in scratch RAM starting with a flag byte (high bit 317# set means active message), one length byte, and then the message itself. 318# 319 mov SCBARRAY+1 call disconnect # disconnect ok? 320 321 and SINDEX,0x7,SCBARRAY+1 # lun 322 or SINDEX,A # return value from disconnect 323 or SINDEX,0x80 call mk_mesg # IDENTIFY message 324 325 mov A,SINDEX 326 test SCBARRAY+0,0xc0 jz !message # WDTR or SDTR?? 327 cmp MSG_START+0,A jne !message # did driver beat us? 328 mvi MSG_START+1 call mk_dtr # build DTR message if needed 329 330!message: 331 332# Enable selection phase as an initiator, and do automatic ATN 333# after the selection. 334# 335 mvi SCSISEQ,0x48 # ENSELO|ENAUTOATNO 336 337# Wait for successful arbitration. The AIC-7770 documentation says 338# that SELINGO indicates successful arbitration, and that it should 339# be used to look for SELDO. However, if the sequencer is paused at 340# just the right time - a parallel fsck(8) on two drives did it for 341# me - then SELINGO can flip back to false before we've seen it. This 342# makes the sequencer sit in the arbitration loop forever. This is 343# Not Good. 344# 345# Therefore, I've added a check in the arbitration loop for SELDO 346# too. This could arguably be made a critical section by disabling 347# pauses, but I don't want to make a potentially infinite loop a CS. 348# I suppose you could fold it into the select loop, too, but since 349# I've been hunting this bug for four days it's kinda like a trophy. 350# 351arbitrate: 352 test SSTAT0,0x40 jnz *select # SELDO 353 test SSTAT0,0x10 jz arbitrate # SELINGO 354 355# Wait for a successful selection. If the hardware selection 356# timer goes off, then the driver gets the interrupt, so we don't 357# need to worry about it. 358# 359select: 360 test SSTAT0,0x40 jz select # SELDO 361 jmp *select 362 363# Reselection is being initiated by a target - we've seen the BSY 364# line driven active, and we didn't do it! Enable the reselection 365# hardware, and wait for it to finish. Make a note that we've been 366# reselected, but haven't seen an IDENTIFY message from the target 367# yet. 368# 369reselect: 370 mvi SCSISEQ,0x10 # ENRSELI 371 372reselect1: 373 test SSTAT0,0x20 jz reselect1 # SELDI 374 mov SELID call initialize 375 376 and FLAGS,0x3f # reselected, no IDENTIFY 377 or FLAGS,RESELECTED 378 379# After the [re]selection, make sure that the [re]selection enable 380# bit is off. This chip is flaky enough without extra things 381# turned on. Also clear the BUSFREE bit in SSTAT1 since we'll be 382# using it shortly. 383# 384*select: 385 clr SCSISEQ 386 mvi CLRSINT1,0x8 # CLRBUSFREE 387 388# Main loop for information transfer phases. If BSY is false, then 389# we have a bus free condition, expected or not. Otherwise, wait 390# for the target to assert REQ before checking MSG, C/D and I/O 391# for the bus phase. 392# 393# We can't simply look at the values of SCSISIGI here (if we want 394# to do synchronous data transfer), because the target won't assert 395# REQ if it's already sent us some data that we haven't acknowledged 396# yet. 397# 398ITloop: 399 test SSTAT1,0x8 jnz p_busfree # BUSFREE 400 test SSTAT1,0x1 jz ITloop # REQINIT 401 402 and A,0xe0,SCSISIGI # CDI|IOI|MSGI 403 404 cmp ALLZEROS,A je p_dataout 405 cmp A,0x40 je p_datain 406 cmp A,0x80 je p_command 407 cmp A,0xc0 je p_status 408 cmp A,0xa0 je p_mesgout 409 cmp A,0xe0 je p_mesgin 410 411 mvi INTSTAT,BAD_PHASE # unknown - signal driver 412 413p_dataout: 414 mvi 0 call scsisig # !CDO|!IOO|!MSGO 415 call assert 416 call sg_load 417 418 mvi DINDEX,HADDR 419 mvi SCBARRAY+19 call bcopy_4 420 421# mvi DINDEX,HCNT # implicit since HCNT is next to HADDR 422 mvi SCBARRAY+23 call bcopy_3 423 424 mvi DINDEX,STCNT 425 mvi SCBARRAY+23 call bcopy_3 426 427 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 428 # DIRECTION|FIFORESET 429 430# After a DMA finishes, save the final transfer pointer and count 431# back into the SCB, in case a device disconnects in the middle of 432# a transfer. Use SHADDR and STCNT instead of HADDR and HCNT, since 433# it's a reflection of how many bytes were transferred on the SCSI 434# (as opposed to the host) bus. 435# 436 mvi DINDEX,SCBARRAY+23 437 mvi STCNT call bcopy_3 438 439 mvi DINDEX,SCBARRAY+19 440 mvi SHADDR call bcopy_4 441 442 call sg_advance 443 mov SCBARRAY+18,SG_COUNT # residual S/G count 444 445 jmp ITloop 446 447p_datain: 448 mvi 0x40 call scsisig # !CDO|IOO|!MSGO 449 call assert 450 call sg_load 451 452 mvi DINDEX,HADDR 453 mvi SCBARRAY+19 call bcopy_4 454 455# mvi DINDEX,HCNT # implicit since HCNT is next to HADDR 456 mvi SCBARRAY+23 call bcopy_3 457 458 mvi DINDEX,STCNT 459 mvi SCBARRAY+23 call bcopy_3 460 461 mvi 0x39 call dma # SCSIEN|SDMAEN|HDMAEN| 462 # !DIRECTION|FIFORESET 463 mvi DINDEX,SCBARRAY+23 464 mvi STCNT call bcopy_3 465 466 mvi DINDEX,SCBARRAY+19 467 mvi SHADDR call bcopy_4 468 469 call sg_advance 470 mov SCBARRAY+18,SG_COUNT # residual S/G count 471 472 jmp ITloop 473 474# Command phase. Set up the DMA registers and let 'er rip - the 475# two bytes after the SCB SCSI_cmd_length are zeroed by the driver, 476# so we can copy those three bytes directly into HCNT. 477# 478p_command: 479 mvi 0x80 call scsisig # CDO|!IOO|!MSGO 480 call assert 481 482 mvi DINDEX,HADDR 483 mvi SCBARRAY+7 call bcopy_4 484 485# mvi DINDEX,HCNT # implicit since HCNT is next to HADDR 486 mvi SCBARRAY+11 call bcopy_3 487 488 mvi DINDEX,STCNT 489 mvi SCBARRAY+11 call bcopy_3 490 491 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 492 # DIRECTION|FIFORESET 493 jmp ITloop 494 495# Status phase. Wait for the data byte to appear, then read it 496# and store it into the SCB. 497# 498p_status: 499 mvi 0xc0 call scsisig # CDO|IOO|!MSGO 500 501 mvi SCBARRAY+14 call inb 502 jmp ITloop 503 504# Message out phase. If there is no active message, but the target 505# took us into this phase anyway, build a no-op message and send it. 506# 507p_mesgout: 508 mvi 0xa0 call scsisig # CDO|!IOO|MSGO 509 mvi 0x8 call mk_mesg # build NOP message 510 511# Set up automatic PIO transfer from MSG_START. Bit 3 in 512# SXFRCTL0 (SPIOEN) is already on. 513# 514 mvi SINDEX,MSG_START+0 515 mov DINDEX,MSG_LEN 516 clr A 517 518# When target asks for a byte, drop ATN if it's the last one in 519# the message. Otherwise, keep going until the message is exhausted. 520# (We can't use outb for this since it wants the input in SINDEX.) 521# 522# Keep an eye out for a phase change, in case the target issues 523# a MESSAGE REJECT. 524# 525p_mesgout2: 526 test SSTAT0,0x2 jz p_mesgout2 # SPIORDY 527 test SSTAT1,0x10 jnz p_mesgout6 # PHASEMIS 528 529 cmp DINDEX,1 jne p_mesgout3 # last byte? 530 mvi CLRSINT1,0x40 # CLRATNO - drop ATN 531 532# Write a byte to the SCSI bus. The AIC-7770 refuses to automatically 533# send ACKs in automatic PIO or DMA mode unless you make sure that the 534# "expected" bus phase in SCSISIGO matches the actual bus phase. This 535# behaviour is completely undocumented and caused me several days of 536# grief. 537# 538# After plugging in different drives to test with and using a longer 539# SCSI cable, I found that I/O in Automatic PIO mode ceased to function, 540# especially when transferring >1 byte. It seems to be much more stable 541# if STCNT is set to one before the transfer, and SDONE (in SSTAT0) is 542# polled for transfer completion - for both output _and_ input. The 543# only theory I have is that SPIORDY doesn't drop right away when SCSIDATL 544# is accessed (like the documentation says it does), and that on a longer 545# cable run, the sequencer code was fast enough to loop back and see 546# an SPIORDY that hadn't dropped yet. 547# 548p_mesgout3: 549 call one_stcnt 550 mov SCSIDATL,SINDIR 551 552p_mesgout4: 553 test SSTAT0,0x4 jz p_mesgout4 # SDONE 554 dec DINDEX 555 inc A 556 cmp MSG_LEN,A jne p_mesgout2 557 558# If the next bus phase after ATN drops is a message out, it means 559# that the target is requesting that the last message(s) be resent. 560# 561p_mesgout5: 562 test SSTAT1,0x8 jnz p_mesgout6 # BUSFREE 563 test SSTAT1,0x1 jz p_mesgout5 # REQINIT 564 565 and A,0xe0,SCSISIGI # CDI|IOI|MSGI 566 cmp A,0xa0 jne p_mesgout6 567 mvi 0x10 call scsisig # ATNO - re-assert ATN 568 569 jmp ITloop 570 571p_mesgout6: 572 mvi CLRSINT1,0x40 # CLRATNO - in case of PHASEMIS 573 and FLAGS,0xdf # no active msg 574 jmp ITloop 575 576# Message in phase. Bytes are read using Automatic PIO mode, but not 577# using inb. This alleviates a race condition, namely that if ATN had 578# to be asserted under Automatic PIO mode, it had to beat the SCSI 579# circuitry sending an ACK to the target. This showed up under heavy 580# loads and really confused things, since ABORT commands wouldn't be 581# seen by the drive after an IDENTIFY message in until it had changed 582# to a data I/O phase. 583# 584p_mesgin: 585 mvi 0xe0 call scsisig # CDO|IOO|MSGO 586 mvi A call inb_first # read the 1st message byte 587 mvi REJBYTE,A # save it for the driver 588 589 cmp ALLZEROS,A jne p_mesgin1 590 591# We got a "command complete" message, so put the SCB pointer 592# into the Queue Out, and trigger a completion interrupt. 593# Check status for non zero return and interrupt driver if needed 594# This allows the driver to interpret errors only when they occur 595# instead of always uploading the scb. If the status is SCSI_CHECK, 596# the driver will download a new scb requesting sense, to replace 597# the old one and the sequencer code will imediately jump to start 598# working on it. If the kernel driver does not wish to request sense, 599# the sequencer program counter is incremented by 1, preventing another run 600# on the current SCB and the command is allowed to complete. We don't 601# bother to post to the QOUTFIFO in the error case since it would require 602# extra work in the kernel driver to ensure that the entry was removed 603# before the command complete code tried processing it. 604 605 test SCBARRAY+14,0xff jz status_ok # 0 Status? 606 mvi INTSTAT,BAD_STATUS # let driver know 607 test FLAGS,SENSE jz status_ok 608 jmp p_mesgin_done 609 610status_ok: 611 612# First, mark this target as free. 613 and FUNCTION1,0x70,SCBARRAY+1 614 mov A,FUNCTION1 615 test SCBARRAY+1,0x88 jz clear_a 616 xor ACTIVE_B,A 617 jmp complete 618 619clear_a: 620 xor ACTIVE_A,A 621 622complete: 623 mov QOUTFIFO,SCBPTR 624 mvi INTSTAT,0x02 # CMDCMPLT 625 jmp p_mesgin_done 626 627# Is it an extended message? We only support the synchronous and wide data 628# transfer request messages, which will probably be in response to 629# WDTR or SDTR message outs from us. If it's not SDTR or WDTR, reject it - 630# apparently this can be done after any message in byte, according 631# to the SCSI-2 spec. 632# 633p_mesgin1: 634 cmp A,1 jne p_mesgin2 # extended message code? 635 636 mvi ARG_1 call inb_next # extended message length 637 mvi A call inb_next # extended message code 638 639 cmp A,1 je p_mesginSDTR # Syncronous negotiation message 640 cmp A,3 je p_mesginWDTR # Wide negotiation message 641 jmp p_mesginN 642 643p_mesginWDTR: 644 cmp ARG_1,2 jne p_mesginN # extended mesg length = 2 645 mvi A call inb_next # Width of bus 646 mvi INTSTAT,MSG_WDTR # let driver know 647 test RETURN_1,0x80 jz p_mesgin_done# Do we need to send WDTR? 648 649# We didn't initiate the wide negotiation, so we must respond to the request 650 and RETURN_1,0x7f # Clear the SEND_WDTR Flag 651 or FLAGS,ACTIVE_MSG 652 mvi DINDEX,MSG_START+0 653 mvi MSG_START+0 call mk_wdtr # build WDTR message 654 or SINDEX,0x10,SIGSTATE # turn on ATNO 655 call scsisig 656 jmp p_mesgin_done 657 658p_mesginSDTR: 659 cmp ARG_1,3 jne p_mesginN # extended mesg length = 3 660 mvi ARG_1 call inb_next # xfer period 661 mvi A call inb_next # REQ/ACK offset 662 mvi INTSTAT,MSG_SDTR # call driver to convert 663 664 test RETURN_1,0x80 jz p_mesgin_done# Do we need to mk_sdtr? 665 666 or FLAGS,ACTIVE_MSG 667 mvi DINDEX, MSG_START+0 668 mvi MSG_START+0 call mk_sdtr 669 or SINDEX,0x10,SIGSTATE # turn on ATNO 670 call scsisig 671 jmp p_mesgin_done 672 673# Is it a disconnect message? Set a flag in the SCB to remind us 674# and await the bus going free. 675# 676p_mesgin2: 677 cmp A,4 jne p_mesgin3 # disconnect code? 678 679 or SCBARRAY+0,0x4 # set "disconnected" bit 680 jmp p_mesgin_done 681 682# Save data pointers message? Copy working values into the SCB, 683# usually in preparation for a disconnect. 684# 685p_mesgin3: 686 cmp A,2 jne p_mesgin4 # save data pointers code? 687 688 call sg_ram2scb 689 jmp p_mesgin_done 690 691# Restore pointers message? Data pointers are recopied from the 692# SCB anyway at the start of any DMA operation, so the only thing 693# to copy is the scatter-gather values. 694# 695p_mesgin4: 696 cmp A,3 jne p_mesgin5 # restore pointers code? 697 698 call sg_scb2ram 699 jmp p_mesgin_done 700 701# Identify message? For a reconnecting target, this tells us the lun 702# that the reconnection is for - find the correct SCB and switch to it, 703# clearing the "disconnected" bit so we don't "find" it by accident later. 704# 705p_mesgin5: 706 test A,0x80 jz p_mesgin6 # identify message? 707 708 test A,0x78 jnz p_mesginN # !DiscPriv|!LUNTAR|!Reserved 709 710 mov A call findSCB # switch to correct SCB 711 712# If a active message is present after calling findSCB, then either it 713# or the driver is trying to abort the command. Either way, something 714# untoward has happened and we should just leave it alone. 715# 716 test FLAGS,ACTIVE_MSG jnz p_mesgin_done 717 718 and SCBARRAY+0,0xfb # clear disconnect bit in SCB 719 or FLAGS,0xc0 # make note of IDENTIFY 720 721 call sg_scb2ram # implied restore pointers 722 # required on reselect 723 jmp p_mesgin_done 724 725# Message reject? Let the kernel driver handle this. If we have an 726# outstanding WDTR or SDTR negotiation, assume that it's a response from 727# the target selecting 8bit or asynchronous transfer, otherwise just ignore 728# it since we have no clue what it pertains to. 729# 730p_mesgin6: 731 cmp A,7 jne p_mesgin7 # message reject code? 732 733 mvi INTSTAT, MSG_REJECT 734 jmp p_mesgin_done 735 736# [ ADD MORE MESSAGE HANDLING HERE ] 737# 738p_mesgin7: 739 740# We have no idea what this message in is, and there's no way 741# to pass it up to the kernel, so we issue a message reject and 742# hope for the best. Since we're now using manual PIO mode to 743# read in the message, there should no longer be a race condition 744# present when we assert ATN. In any case, rejection should be a 745# rare occurrence - signal the driver when it happens. 746# 747p_mesginN: 748 or SINDEX,0x10,SIGSTATE # turn on ATNO 749 call scsisig 750 mvi INTSTAT,SEND_REJECT # let driver know 751 752 mvi 0x7 call mk_mesg # MESSAGE REJECT message 753 754p_mesgin_done: 755 call inb_last # ack & turn auto PIO back on 756 jmp ITloop 757 758# Bus free phase. It might be useful to interrupt the device 759# driver if we aren't expecting this. For now, make sure that 760# ATN isn't being asserted and look for a new command. 761# 762p_busfree: 763 mvi CLRSINT1,0x40 # CLRATNO 764 clr SIGSTATE 765 jmp start 766 767# Instead of a generic bcopy routine that requires an argument, we unroll 768# the two cases that are actually used, and call them explicitly. This 769# not only reduces the overhead of doing a bcopy by 2/3rds, but ends up 770# saving space in the program since you don't have to put the argument 771# into the accumulator before the call. Both functions expect DINDEX to 772# contain the destination address and SINDEX to contain the source 773# address. 774bcopy_3: 775 mov DINDIR,SINDIR 776 mov DINDIR,SINDIR 777 mov DINDIR,SINDIR ret 778 779bcopy_4: 780 mov DINDIR,SINDIR 781 mov DINDIR,SINDIR 782 mov DINDIR,SINDIR 783 mov DINDIR,SINDIR ret 784 785 786# Locking the driver out, build a one-byte message passed in SINDEX 787# if there is no active message already. SINDEX is returned intact. 788# 789mk_mesg: 790 mvi SEQCTL,0x50 # PAUSEDIS|FASTMODE 791 test FLAGS,ACTIVE_MSG jnz mk_mesg1 # active message? 792 793 or FLAGS,ACTIVE_MSG # if not, there is now 794 mvi MSG_LEN,1 # length = 1 795 mov MSG_START+0,SINDEX # 1-byte message 796 797mk_mesg1: 798 mvi SEQCTL,0x10 ret # !PAUSEDIS|FASTMODE 799 800# Input byte in Automatic PIO mode. The address to store the byte 801# in should be in SINDEX. DINDEX will be used by this routine. 802# 803inb: 804 test SSTAT0,0x2 jz inb # SPIORDY 805 mov DINDEX,SINDEX 806 call one_stcnt # xfer one byte 807 mov DINDIR,SCSIDATL 808inb1: 809 test SSTAT0,0x4 jz inb1 # SDONE - wait to "finish" 810 ret 811 812# Carefully read data in Automatic PIO mode. I first tried this using 813# Manual PIO mode, but it gave me continual underrun errors, probably 814# indicating that I did something wrong, but I feel more secure leaving 815# Automatic PIO on all the time. 816# 817# According to Adaptec's documentation, an ACK is not sent on input from 818# the target until SCSIDATL is read from. So we wait until SCSIDATL is 819# latched (the usual way), then read the data byte directly off the bus 820# using SCSIBUSL. When we have pulled the ATN line, or we just want to 821# acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI 822# spec guarantees that the target will hold the data byte on the bus until 823# we send our ACK. 824# 825# The assumption here is that these are called in a particular sequence, 826# and that REQ is already set when inb_first is called. inb_{first,next} 827# use the same calling convention as inb. 828# 829inb_first: 830 mov DINDEX,SINDEX 831 mov DINDIR,SCSIBUSL ret # read byte directly from bus 832 833inb_next: 834 mov DINDEX,SINDEX # save SINDEX 835 836 call one_stcnt # xfer one byte 837 mov NONE,SCSIDATL # dummy read from latch to ACK 838inb_next1: 839 test SSTAT0,0x4 jz inb_next1 # SDONE 840inb_next2: 841 test SSTAT0,0x2 jz inb_next2 # SPIORDY - wait for next byte 842 mov DINDIR,SCSIBUSL ret # read byte directly from bus 843 844inb_last: 845 call one_stcnt # ACK with dummy read 846 mov NONE,SCSIDATL 847inb_last1: 848 test SSTAT0,0x4 jz inb_last1 # wait for completion 849 ret 850 851# Output byte in Automatic PIO mode. The byte to output should be 852# in SINDEX. If DROPATN's high bit is set, then ATN will be dropped 853# before the byte is output. 854# 855outb: 856 test SSTAT0,0x2 jz outb # SPIORDY 857 call one_stcnt # xfer one byte 858 859 test DROPATN,0x80 jz outb1 860 mvi CLRSINT1,0x40 # CLRATNO 861 clr DROPATN 862outb1: 863 mov SCSIDATL,SINDEX 864outb2: 865 test SSTAT0,0x4 jz outb2 # SDONE 866 ret 867 868# Write the value "1" into the STCNT registers, for Automatic PIO 869# transfers. 870# 871one_stcnt: 872 clr STCNT+2 873 clr STCNT+1 874 mvi STCNT+0,1 ret 875 876# DMA data transfer. HADDR and HCNT must be loaded first, and 877# SINDEX should contain the value to load DFCNTRL with - 0x3d for 878# host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared 879# during initialization. 880# 881dma: 882 mov DFCNTRL,SINDEX 883dma1: 884dma2: 885 test SSTAT0,0x1 jnz dma3 # DMADONE 886 test SSTAT1,0x10 jz dma1 # PHASEMIS, ie. underrun 887 888# We will be "done" DMAing when the transfer count goes to zero, or 889# the target changes the phase (in light of this, it makes sense that 890# the DMA circuitry doesn't ACK when PHASEMIS is active). If we are 891# doing a SCSI->Host transfer, the data FIFO should be flushed auto- 892# magically on STCNT=0 or a phase change, so just wait for FIFO empty 893# status. 894# 895dma3: 896 test SINDEX,0x4 jnz dma5 # DIRECTION 897dma4: 898 test DFSTATUS,0x1 jz dma4 # !FIFOEMP 899 900# Now shut the DMA enables off, and copy STCNT (ie. the underrun 901# amount, if any) to the SCB registers; SG_COUNT will get copied to 902# the SCB's residual S/G count field after sg_advance is called. Make 903# sure that the DMA enables are actually off first lest we get an ILLSADDR. 904# 905dma5: 906 clr DFCNTRL # disable DMA 907dma6: 908 test DFCNTRL,0x38 jnz dma6 # SCSIENACK|SDMAENACK|HDMAENACK 909 910 mvi DINDEX,SCBARRAY+15 911 mvi STCNT call bcopy_3 912 913 ret 914 915# Common SCSI initialization for selection and reselection. Expects 916# the target SCSI ID to be in the upper four bits of SINDEX, and A's 917# contents are stomped on return. 918# 919initialize: 920 and SINDEX,0xf0 # Get target ID 921 and A,0x0f,SCSIID 922 or SINDEX,A 923 mov SCSIID,SINDEX 924 925# Esundry initialization. 926# 927 clr DROPATN 928 clr SIGSTATE 929 930# Turn on Automatic PIO mode now, before we expect to see a REQ 931# from the target. It shouldn't hurt anything to leave it on. Set 932# CLRCHN here before the target has entered a data transfer mode - 933# with synchronous SCSI, if you do it later, you blow away some 934# data in the SCSI FIFO that the target has already sent to you. 935# 936 mvi SXFRCTL0,0x8a # DFON|SPIOEN|CLRCHN 937 938# Initialize scatter-gather pointers by setting up the working copy 939# in scratch RAM. 940# 941 call sg_scb2ram 942 943# Initialize SCSIRATE with the appropriate value for this target. 944# 945 call ndx_dtr 946 mov SCSIRATE,SINDIR ret 947 948# Assert that if we've been reselected, then we've seen an IDENTIFY 949# message. 950# 951assert: 952 test FLAGS,RESELECTED jz assert1 # reselected? 953 test FLAGS,IDENTIFY_SEEN jnz assert1 # seen IDENTIFY? 954 955 mvi INTSTAT,NO_IDENT # no - cause a kernel panic 956 957assert1: 958 ret 959 960# Find out if disconnection is ok from the information the BIOS has left 961# us. The tcl from SCBARRAY+1 should be in SINDEX; A will 962# contain either 0x40 (disconnection ok) or 0x00 (disconnection not ok) 963# on exit. 964# 965# To allow for wide or twin busses, we check the upper bit of the target ID 966# and the channel ID and look at the appropriate disconnect register. 967# 968disconnect: 969 and FUNCTION1,0x70,SINDEX # strip off extra just in case 970 mov A,FUNCTION1 971 test SINDEX, 0x88 jz disconnect_a 972 973 test DISC_DSB_B,A jz disconnect1 # bit nonzero if DISabled 974 clr A ret 975 976disconnect_a: 977 test DISC_DSB_A,A jz disconnect1 # bit nonzero if DISabled 978 clr A ret 979 980disconnect1: 981 mvi A,0x40 ret 982 983# Locate the SCB matching the target ID in SELID and the lun in the lower 984# three bits of SINDEX, and switch the SCB to it. Have the kernel print 985# a warning message if it can't be found, and generate an ABORT message 986# to the target. We keep the value of the t/c/l that we are trying to find 987# in DINDEX so it is not overwritten during our check to see if we are 988# at the last SCB. 989# 990findSCB: 991 and A,0x7,SINDEX # lun in lower three bits 992 or DINDEX,A,SELID 993 and DINDEX,0xf7 994 and A,0x08,SBLKCTL # B Channel?? 995 or DINDEX,A 996 clr SINDEX 997 998findSCB1: 999 mov A,DINDEX 1000 mov SCBPTR,SINDEX # switch to new SCB 1001 cmp SCBARRAY+1,A jne findSCB2 # target ID/channel/lun match? 1002 test SCBARRAY+0,0x4 jz findSCB2 # should be disconnected 1003 ret 1004 1005findSCB2: 1006 inc SINDEX 1007 mov A,SCBCOUNT 1008 cmp SINDEX,A jne findSCB1 1009 1010 mvi INTSTAT,NO_MATCH # not found - signal kernel 1011 mvi 0x6 call mk_mesg # ABORT message 1012 1013 or SINDEX,0x10,SIGSTATE # assert ATNO 1014 call scsisig 1015 ret 1016 1017# Make a working copy of the scatter-gather parameters in the SCB. 1018# 1019sg_scb2ram: 1020 mov SG_COUNT,SCBARRAY+2 1021 1022 mvi DINDEX,SG_NEXT 1023 mvi SCBARRAY+3 call bcopy_4 1024 1025 mvi SG_NOLOAD,0x80 1026 test SCBARRAY+0,0x10 jnz sg_scb2ram1 # don't reload s/g? 1027 clr SG_NOLOAD 1028 1029sg_scb2ram1: 1030 ret 1031 1032# Copying RAM values back to SCB, for Save Data Pointers message. 1033# 1034sg_ram2scb: 1035 mov SCBARRAY+2,SG_COUNT 1036 1037 mvi DINDEX,SCBARRAY+3 1038 mvi SG_NEXT call bcopy_4 1039 1040 and SCBARRAY+0,0xef,SCBARRAY+0 1041 test SG_NOLOAD,0x80 jz sg_ram2scb1 # reload s/g? 1042 or SCBARRAY+0,SG_LOAD 1043 1044sg_ram2scb1: 1045 ret 1046 1047# Load a struct scatter if needed and set up the data address and 1048# length. If the working value of the SG count is nonzero, then 1049# we need to load a new set of values. 1050# 1051# This, like the above DMA, assumes a little-endian host data storage. 1052# 1053sg_load: 1054 test SG_COUNT,0xff jz sg_load3 # SG being used? 1055 test SG_NOLOAD,0x80 jnz sg_load3 # don't reload s/g? 1056 1057 clr HCNT+2 1058 clr HCNT+1 1059 mvi HCNT+0,SG_SIZEOF 1060 1061 mvi DINDEX,HADDR 1062 mvi SG_NEXT call bcopy_4 1063 1064 mvi DFCNTRL,0xd # HDMAEN|DIRECTION|FIFORESET 1065 1066# Wait for DMA from host memory to data FIFO to complete, then disable 1067# DMA and wait for it to acknowledge that it's off. 1068# 1069sg_load1: 1070 test DFSTATUS,0x8 jz sg_load1 # HDONE 1071 1072 clr DFCNTRL # disable DMA 1073sg_load2: 1074 test DFCNTRL,0x8 jnz sg_load2 # HDMAENACK 1075 1076# Copy data from FIFO into SCB data pointer and data count. This assumes 1077# that the struct scatterlist has this structure (this and sizeof(struct 1078# scatterlist) == 12 are asserted in aic7xxx.c): 1079# 1080# struct scatterlist { 1081# char *address; /* four bytes, little-endian order */ 1082# ... /* four bytes, ignored */ 1083# unsigned short length; /* two bytes, little-endian order */ 1084# } 1085# 1086 1087# Not in FreeBSD. the scatter list is only 8 bytes. 1088# 1089# struct ahc_dma_seg { 1090# physaddr addr; /* four bytes, little-endian order */ 1091# long len; /* four bytes, little endian order */ 1092# }; 1093# 1094 1095 mov SCBARRAY+19,DFDAT # new data address 1096 mov SCBARRAY+20,DFDAT 1097 mov SCBARRAY+21,DFDAT 1098 mov SCBARRAY+22,DFDAT 1099 1100# For Linux, we must throw away four bytes since there is a 32bit gap 1101# in the middle of a struct scatterlist 1102# mov NONE,DFDAT 1103# mov NONE,DFDAT 1104# mov NONE,DFDAT 1105# mov NONE,DFDAT 1106 1107 mov SCBARRAY+23,DFDAT 1108 mov SCBARRAY+24,DFDAT 1109 mov SCBARRAY+25,DFDAT #Only support 24 bit length. 1110 1111sg_load3: 1112 ret 1113 1114# Advance the scatter-gather pointers only IF NEEDED. If SG is enabled, 1115# and the SCSI transfer count is zero (note that this should be called 1116# right after a DMA finishes), then move the working copies of the SG 1117# pointer/length along. If the SCSI transfer count is not zero, then 1118# presumably the target is disconnecting - do not reload the SG values 1119# next time. 1120# 1121sg_advance: 1122 test SG_COUNT,0xff jz sg_advance2 # s/g enabled? 1123 1124 test STCNT+0,0xff jnz sg_advance1 # SCSI transfer count nonzero? 1125 test STCNT+1,0xff jnz sg_advance1 1126 test STCNT+2,0xff jnz sg_advance1 1127 1128 clr SG_NOLOAD # reload s/g next time 1129 dec SG_COUNT # one less segment to go 1130 1131 clr A # add sizeof(struct scatter) 1132 add SG_NEXT+0,SG_SIZEOF,SG_NEXT+0 1133 adc SG_NEXT+1,A,SG_NEXT+1 1134 adc SG_NEXT+2,A,SG_NEXT+2 1135 adc SG_NEXT+3,A,SG_NEXT+3 ret 1136 1137sg_advance1: 1138 mvi SG_NOLOAD,0x80 # don't reload s/g next time 1139sg_advance2: 1140 ret 1141 1142# Add the array base SYNCNEG to the target offset (the target address 1143# is in SCSIID), and return the result in SINDEX. The accumulator 1144# contains the 3->8 decoding of the target ID on return. 1145# 1146ndx_dtr: 1147 shr A,SCSIID,4 1148 test SBLKCTL,0x08 jz ndx_dtr_2 1149 or A,0x08 # Channel B entries add 8 1150ndx_dtr_2: 1151 add SINDEX,SYNCNEG,A 1152 1153 and FUNCTION1,0x70,SCSIID # 3-bit target address decode 1154 mov A,FUNCTION1 ret 1155 1156# If we need to negotiate transfer parameters, build the WDTR or SDTR message 1157# starting at the address passed in SINDEX. DINDEX is modified on return. 1158# The SCSI-II spec requires that Wide negotiation occur first and you can 1159# only negotiat one or the other at a time otherwise in the event of a message 1160# reject, you wouldn't be able to tell which message was the culpret. 1161# 1162mk_dtr: 1163 mov DINDEX,SINDEX # save SINDEX 1164 1165 test SCBARRAY+0,NEEDWDTR jnz mk_wdtr_16bit 1166 jmp mk_sdtr 1167 1168mk_wdtr_16bit: 1169 mvi ARG_1,BUS_16_BIT 1170mk_wdtr: 1171 mvi DINDIR,1 # extended message 1172 mvi DINDIR,2 # extended message length = 2 1173 mvi DINDIR,3 # WDTR code 1174 mov DINDIR,ARG_1 # bus width 1175 1176 add MSG_LEN,-MSG_START+0,DINDEX ret # update message length 1177 1178mk_sdtr: 1179 mvi DINDIR,1 # extended message 1180 mvi DINDIR,3 # extended message length = 3 1181 mvi DINDIR,1 # SDTR code 1182 call sdtr_to_rate 1183 mov DINDIR,RETURN_1 # REQ/ACK transfer period 1184 and DINDIR,0xf,SINDIR # Sync Offset 1185 1186 add MSG_LEN,-MSG_START+0,DINDEX ret # update message length 1187 1188# Tag Message if Tag enabled in SCB control block. Use SCBPTR as the tag 1189# value 1190 1191#mk_tag: 1192# test SCBARRAY+0,0x10 jz mk_tag_done # Tag Enabled? 1193# and A,0x03,SCBARRYA+0 1194# or A,0x20 1195# mov DINDIR,A 1196# mov DINDIR,SCBPTR 1197# 1198# add MSG_LEN,-MSG_START+0,DINDEX # update message length 1199 1200#mk_tag_done: 1201# ret 1202 1203 1204# Set SCSI bus control signal state. This also saves the last-written 1205# value into a location where the higher-level driver can read it - if 1206# it has to send an ABORT or RESET message, then it needs to know this 1207# so it can assert ATN without upsetting SCSISIGO. The new value is 1208# expected in SINDEX. Change the actual state last to avoid contention 1209# from the driver. 1210# 1211scsisig: 1212 mov SIGSTATE,SINDEX 1213 mov SCSISIGO,SINDEX ret 1214 1215sdtr_to_rate: 1216 call ndx_dtr # index scratch space for target 1217 shr A,SINDIR,0x4 1218 dec SINDEX #Preserve SINDEX 1219 and A,0x7 1220 clr RETURN_1 1221sdtr_to_rate_loop: 1222 test A,0x0f jz sdtr_to_rate_done 1223 add RETURN_1,0x18 1224 dec A 1225 jmp sdtr_to_rate_loop 1226sdtr_to_rate_done: 1227 shr RETURN_1,0x2 1228 add RETURN_1,0x18 ret 1229