aic7xxx.seq revision 4866
1178476Sjb# @(#)aic7xxx.seq 1.31 94/11/25 jda 2178476Sjb# 3178476Sjb# Adaptec 274x device driver for Linux. 4178476Sjb# Copyright (c) 1994 The University of Calgary Department of Computer Science. 5178476Sjb# 6178476Sjb# This program is free software; you can redistribute it and/or modify 7178476Sjb# it under the terms of the GNU General Public License as published by 8178476Sjb# the Free Software Foundation; either version 2 of the License, or 9178476Sjb# (at your option) any later version. 10178476Sjb# 11178476Sjb# This program is distributed in the hope that it will be useful, 12178476Sjb# but WITHOUT ANY WARRANTY; without even the implied warranty of 13178476Sjb# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14178476Sjb# GNU General Public License for more details. 15178476Sjb# 16178476Sjb# You should have received a copy of the GNU General Public License 17178476Sjb# along with this program; if not, write to the Free Software 18178476Sjb# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19178476Sjb 20178476SjbVERSION AIC7XXX_SEQ_VERSION 1.31 21178476Sjb 22178476SjbSCBMASK = 0x1f 23178476Sjb 24178476SjbSCSISEQ = 0x00 25178476SjbSXFRCTL0 = 0x01 26178476SjbSXFRCTL1 = 0x02 27178476SjbSCSISIGI = 0x03 28178476SjbSCSISIGO = 0x03 29178476SjbSCSIRATE = 0x04 30178476SjbSCSIID = 0x05 31178476SjbSCSIDATL = 0x06 32178476SjbSTCNT = 0x08 33178476SjbSTCNT+0 = 0x08 34178476SjbSTCNT+1 = 0x09 35178476SjbSTCNT+2 = 0x0a 36178476SjbSSTAT0 = 0x0b 37178476SjbCLRSINT1 = 0x0c 38178476SjbSSTAT1 = 0x0c 39178476SjbSIMODE1 = 0x11 40178476SjbSCSIBUSL = 0x12 41178476SjbSHADDR = 0x14 42178476SjbSELID = 0x19 43178476SjbSBLKCTL = 0x1f 44178476SjbSEQCTL = 0x60 45178476SjbA = 0x64 # == ACCUM 46178476SjbSINDEX = 0x65 47178476SjbDINDEX = 0x66 48178476SjbALLZEROS = 0x6a 49178476SjbNONE = 0x6a 50178476SjbSINDIR = 0x6c 51178476SjbDINDIR = 0x6d 52178476SjbFUNCTION1 = 0x6e 53178476SjbHADDR = 0x88 54178476SjbHCNT = 0x8c 55178476SjbHCNT+0 = 0x8c 56HCNT+1 = 0x8d 57HCNT+2 = 0x8e 58SCBPTR = 0x90 59INTSTAT = 0x91 60DFCNTRL = 0x93 61DFSTATUS = 0x94 62DFDAT = 0x99 63QINFIFO = 0x9b 64QINCNT = 0x9c 65QOUTFIFO = 0x9d 66 67SCSICONF = 0x5a 68 69# The two reserved bytes at SCBARRAY+1[23] are expected to be set to 70# zero, and the reserved bit in SCBARRAY+0 is used as an internal flag 71# to indicate whether or not to reload scatter-gather parameters after 72# a disconnect. 73# 74SCBARRAY+0 = 0xa0 75SCBARRAY+1 = 0xa1 76SCBARRAY+2 = 0xa2 77SCBARRAY+3 = 0xa3 78SCBARRAY+7 = 0xa7 79SCBARRAY+11 = 0xab 80SCBARRAY+14 = 0xae 81SCBARRAY+15 = 0xaf 82SCBARRAY+16 = 0xb0 83SCBARRAY+17 = 0xb1 84SCBARRAY+18 = 0xb2 85SCBARRAY+19 = 0xb3 86SCBARRAY+20 = 0xb4 87SCBARRAY+21 = 0xb5 88SCBARRAY+22 = 0xb6 89SCBARRAY+23 = 0xb7 90SCBARRAY+24 = 0xb8 91SCBARRAY+25 = 0xb9 92 93SIGNAL_0 = 0x01 # unknown scsi bus phase 94SIGNAL_1 = 0x11 # message reject 95SIGNAL_2 = 0x21 # no IDENTIFY after reconnect 96SIGNAL_3 = 0x31 # no cmd match for reconnect 97SIGNAL_4 = 0x41 # SDTR -> SCSIRATE conversion 98STATUS_ERROR = 0x51 99 100# The host adapter card (at least the BIOS) uses 20-2f for SCSI 101# device information, 32-33 and 5a-5f as well. Since we don't support 102# wide or twin-bus SCSI, 28-2f can be reclaimed. As it turns out, the 103# BIOS trashes 20-27 anyway, writing the synchronous negotiation results 104# on top of the BIOS values, so we re-use those for our per-target 105# scratchspace (actually a value that can be copied directly into 106# SCSIRATE). This implies, since we can't get the BIOS config values, 107# that all targets will be negotiated with for synchronous transfer. 108# NEEDSDTR has one bit per target indicating if an SDTR message is 109# needed for that device - this will be set initially, as well as 110# after a bus reset condition. 111# 112# The high bit of DROPATN is set if ATN should be dropped before the ACK 113# when outb is called. REJBYTE contains the first byte of a MESSAGE IN 114# message, so the driver can report an intelligible error if a message is 115# rejected. 116# 117# RESELECT's high bit is true if we are currently handling a reselect; 118# its next-highest bit is true ONLY IF we've seen an IDENTIFY message 119# from the reselecting target. If we haven't had IDENTIFY, then we have 120# no idea what the lun is, and we can't select the right SCB register 121# bank, so force a kernel panic if the target attempts a data in/out or 122# command phase instead of corrupting something. 123# 124# Note that SG_NEXT occupies four bytes. 125# 126SYNCNEG = 0x20 127DISC_DSB_A = 0x32 128 129DROPATN = 0x30 130REJBYTE = 0x31 131RESELECT = 0x34 132 133MSG_FLAGS = 0x35 134MSG_LEN = 0x36 135MSG_START+0 = 0x37 136MSG_START+1 = 0x38 137MSG_START+2 = 0x39 138MSG_START+3 = 0x3a 139MSG_START+4 = 0x3b 140MSG_START+5 = 0x3c 141-MSG_START+0 = 0xc9 # 2's complement of MSG_START+0 142 143ARG_1 = 0x4c # sdtr conversion args & return 144ARG_2 = 0x4d 145RETURN_1 = 0x4c 146 147SIGSTATE = 0x4e # value written to SCSISIGO 148NEEDSDTR = 0x4f # send SDTR message, 1 bit/trgt 149 150SG_SIZEOF = 0x8 # sizeof(struct scatterlist) 151SG_NOLOAD = 0x50 # load SG pointer/length? 152SG_COUNT = 0x51 # working value of SG count 153SG_NEXT = 0x52 # working value of SG pointer 154SG_NEXT+0 = 0x52 155SG_NEXT+1 = 0x53 156SG_NEXT+2 = 0x54 157SG_NEXT+3 = 0x55 158 159SCBCOUNT = 0x56 # the actual number of SCBs 160ACTIVE_A = 0x57 161 162# Poll QINCNT for work - the lower bits contain 163# the number of entries in the Queue In FIFO. 164# 165start: 166 test SCSISIGI,0x4 jnz reselect # BSYI 167 test QINCNT,SCBMASK jz start 168 169# We have at least one queued SCB now. Set the SCB pointer 170# from the FIFO so we see the right bank of SCB registers, 171# then set SCSI options and set the initiator and target 172# SCSI IDs. 173# 174 mov SCBPTR,QINFIFO 175 176# See if there is not already an active SCB for this target. This code 177# will have to be modified when we add support for dual and wide busses. 178 179 and FUNCTION1,0x70,SCBARRAY+1 180 mov A,FUNCTION1 181 test ACTIVE_A,A jz active 182# Place the currently active back on the queue for later processing 183 mov QINFIFO, SCBPTR 184 jmp start 185 186# Mark the current target as busy and get working on the SCB 187active: 188 or ACTIVE_A,A 189 mov SCBARRAY+1 call initialize 190 clr SG_NOLOAD 191 clr RESELECT 192 193# As soon as we get a successful selection, the target should go 194# into the message out phase since we have ATN asserted. Prepare 195# the message to send, locking out the device driver. If the device 196# driver hasn't beaten us with an ABORT or RESET message, then tack 197# on an SDTR negotiation if required. 198# 199# Messages are stored in scratch RAM starting with a flag byte (high bit 200# set means active message), one length byte, and then the message itself. 201# 202 mov SCBARRAY+1 call disconnect # disconnect ok? 203 204 and SINDEX,0x7,SCBARRAY+1 # lun 205 or SINDEX,A # return value from disconnect 206 or SINDEX,0x80 call mk_mesg # IDENTIFY message 207 208 mov A,SINDEX 209 cmp MSG_START+0,A jne !message # did driver beat us? 210 mvi MSG_START+1 call mk_sdtr # build SDTR message if needed 211 212!message: 213 214# Enable selection phase as an initiator, and do automatic ATN 215# after the selection. 216# 217 mvi SCSISEQ,0x48 # ENSELO|ENAUTOATNO 218 219# Wait for successful arbitration. The AIC-7770 documentation says 220# that SELINGO indicates successful arbitration, and that it should 221# be used to look for SELDO. However, if the sequencer is paused at 222# just the right time - a parallel fsck(8) on two drives did it for 223# me - then SELINGO can flip back to false before we've seen it. This 224# makes the sequencer sit in the arbitration loop forever. This is 225# Not Good. 226# 227# Therefore, I've added a check in the arbitration loop for SELDO 228# too. This could arguably be made a critical section by disabling 229# pauses, but I don't want to make a potentially infinite loop a CS. 230# I suppose you could fold it into the select loop, too, but since 231# I've been hunting this bug for four days it's kinda like a trophy. 232# 233arbitrate: 234 test SSTAT0,0x40 jnz *select # SELDO 235 test SSTAT0,0x10 jz arbitrate # SELINGO 236 237# Wait for a successful selection. If the hardware selection 238# timer goes off, then the driver gets the interrupt, so we don't 239# need to worry about it. 240# 241select: 242 test SSTAT0,0x40 jz select # SELDO 243 jmp *select 244 245# Reselection is being initiated by a target - we've seen the BSY 246# line driven active, and we didn't do it! Enable the reselection 247# hardware, and wait for it to finish. Make a note that we've been 248# reselected, but haven't seen an IDENTIFY message from the target 249# yet. 250# 251reselect: 252 mvi SCSISEQ,0x10 # ENRSELI 253 254reselect1: 255 test SSTAT0,0x20 jz reselect1 # SELDI 256 mov SELID call initialize 257 258 mvi RESELECT,0x80 # reselected, no IDENTIFY 259 260# After the [re]selection, make sure that the [re]selection enable 261# bit is off. This chip is flaky enough without extra things 262# turned on. Also clear the BUSFREE bit in SSTAT1 since we'll be 263# using it shortly. 264# 265*select: 266 clr SCSISEQ 267 mvi CLRSINT1,0x8 # CLRBUSFREE 268 269# Main loop for information transfer phases. If BSY is false, then 270# we have a bus free condition, expected or not. Otherwise, wait 271# for the target to assert REQ before checking MSG, C/D and I/O 272# for the bus phase. 273# 274# We can't simply look at the values of SCSISIGI here (if we want 275# to do synchronous data transfer), because the target won't assert 276# REQ if it's already sent us some data that we haven't acknowledged 277# yet. 278# 279ITloop: 280 test SSTAT1,0x8 jnz p_busfree # BUSFREE 281 test SSTAT1,0x1 jz ITloop # REQINIT 282 283 and A,0xe0,SCSISIGI # CDI|IOI|MSGI 284 285 cmp ALLZEROS,A je p_dataout 286 cmp A,0x40 je p_datain 287 cmp A,0x80 je p_command 288 cmp A,0xc0 je p_status 289 cmp A,0xa0 je p_mesgout 290 cmp A,0xe0 je p_mesgin 291 292 mvi INTSTAT,SIGNAL_0 # unknown - signal driver 293 294p_dataout: 295 mvi 0 call scsisig # !CDO|!IOO|!MSGO 296 call assert 297 call sg_load 298 299 mvi A,3 300 mvi DINDEX,HCNT 301 mvi SCBARRAY+23 call bcopy 302 303 mvi A,3 304 mvi DINDEX,STCNT 305 mvi SCBARRAY+23 call bcopy 306 307 mvi A,4 308 mvi DINDEX,HADDR 309 mvi SCBARRAY+19 call bcopy 310 311 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 312 # DIRECTION|FIFORESET 313 314# After a DMA finishes, save the final transfer pointer and count 315# back into the SCB, in case a device disconnects in the middle of 316# a transfer. Use SHADDR and STCNT instead of HADDR and HCNT, since 317# it's a reflection of how many bytes were transferred on the SCSI 318# (as opposed to the host) bus. 319# 320 mvi A,3 321 mvi DINDEX,SCBARRAY+23 322 mvi STCNT call bcopy 323 324 mvi A,4 325 mvi DINDEX,SCBARRAY+19 326 mvi SHADDR call bcopy 327 328 call sg_advance 329 mov SCBARRAY+18,SG_COUNT # residual S/G count 330 331 jmp ITloop 332 333p_datain: 334 mvi 0x40 call scsisig # !CDO|IOO|!MSGO 335 call assert 336 call sg_load 337 338 mvi A,3 339 mvi DINDEX,HCNT 340 mvi SCBARRAY+23 call bcopy 341 342 mvi A,3 343 mvi DINDEX,STCNT 344 mvi SCBARRAY+23 call bcopy 345 346 mvi A,4 347 mvi DINDEX,HADDR 348 mvi SCBARRAY+19 call bcopy 349 350 mvi 0x39 call dma # SCSIEN|SDMAEN|HDMAEN| 351 # !DIRECTION|FIFORESET 352 mvi A,3 353 mvi DINDEX,SCBARRAY+23 354 mvi STCNT call bcopy 355 356 mvi A,4 357 mvi DINDEX,SCBARRAY+19 358 mvi SHADDR call bcopy 359 360 call sg_advance 361 mov SCBARRAY+18,SG_COUNT # residual S/G count 362 363 jmp ITloop 364 365# Command phase. Set up the DMA registers and let 'er rip - the 366# two bytes after the SCB SCSI_cmd_length are zeroed by the driver, 367# so we can copy those three bytes directly into HCNT. 368# 369p_command: 370 mvi 0x80 call scsisig # CDO|!IOO|!MSGO 371 call assert 372 373 mvi A,3 374 mvi DINDEX,HCNT 375 mvi SCBARRAY+11 call bcopy 376 377 mvi A,3 378 mvi DINDEX,STCNT 379 mvi SCBARRAY+11 call bcopy 380 381 mvi A,4 382 mvi DINDEX,HADDR 383 mvi SCBARRAY+7 call bcopy 384 385 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 386 # DIRECTION|FIFORESET 387 jmp ITloop 388 389# Status phase. Wait for the data byte to appear, then read it 390# and store it into the SCB. 391# 392p_status: 393 mvi 0xc0 call scsisig # CDO|IOO|!MSGO 394 395 mvi SCBARRAY+14 call inb 396 jmp ITloop 397 398# Message out phase. If there is no active message, but the target 399# took us into this phase anyway, build a no-op message and send it. 400# 401p_mesgout: 402 mvi 0xa0 call scsisig # CDO|!IOO|MSGO 403 mvi 0x8 call mk_mesg # build NOP message 404 405# Set up automatic PIO transfer from MSG_START. Bit 3 in 406# SXFRCTL0 (SPIOEN) is already on. 407# 408 mvi SINDEX,MSG_START+0 409 mov DINDEX,MSG_LEN 410 clr A 411 412# When target asks for a byte, drop ATN if it's the last one in 413# the message. Otherwise, keep going until the message is exhausted. 414# (We can't use outb for this since it wants the input in SINDEX.) 415# 416# Keep an eye out for a phase change, in case the target issues 417# a MESSAGE REJECT. 418# 419p_mesgout2: 420 test SSTAT0,0x2 jz p_mesgout2 # SPIORDY 421 test SSTAT1,0x10 jnz p_mesgout6 # PHASEMIS 422 423 cmp DINDEX,1 jne p_mesgout3 # last byte? 424 mvi CLRSINT1,0x40 # CLRATNO - drop ATN 425 426# Write a byte to the SCSI bus. The AIC-7770 refuses to automatically 427# send ACKs in automatic PIO or DMA mode unless you make sure that the 428# "expected" bus phase in SCSISIGO matches the actual bus phase. This 429# behaviour is completely undocumented and caused me several days of 430# grief. 431# 432# After plugging in different drives to test with and using a longer 433# SCSI cable, I found that I/O in Automatic PIO mode ceased to function, 434# especially when transferring >1 byte. It seems to be much more stable 435# if STCNT is set to one before the transfer, and SDONE (in SSTAT0) is 436# polled for transfer completion - for both output _and_ input. The 437# only theory I have is that SPIORDY doesn't drop right away when SCSIDATL 438# is accessed (like the documentation says it does), and that on a longer 439# cable run, the sequencer code was fast enough to loop back and see 440# an SPIORDY that hadn't dropped yet. 441# 442p_mesgout3: 443 call one_stcnt 444 mov SCSIDATL,SINDIR 445 446p_mesgout4: 447 test SSTAT0,0x4 jz p_mesgout4 # SDONE 448 dec DINDEX 449 inc A 450 cmp MSG_LEN,A jne p_mesgout2 451 452# If the next bus phase after ATN drops is a message out, it means 453# that the target is requesting that the last message(s) be resent. 454# 455p_mesgout5: 456 test SSTAT1,0x8 jnz p_mesgout6 # BUSFREE 457 test SSTAT1,0x1 jz p_mesgout5 # REQINIT 458 459 and A,0xe0,SCSISIGI # CDI|IOI|MSGI 460 cmp A,0xa0 jne p_mesgout6 461 mvi 0x10 call scsisig # ATNO - re-assert ATN 462 463 jmp ITloop 464 465p_mesgout6: 466 mvi CLRSINT1,0x40 # CLRATNO - in case of PHASEMIS 467 clr MSG_FLAGS # no active msg 468 jmp ITloop 469 470# Message in phase. Bytes are read using Automatic PIO mode, but not 471# using inb. This alleviates a race condition, namely that if ATN had 472# to be asserted under Automatic PIO mode, it had to beat the SCSI 473# circuitry sending an ACK to the target. This showed up under heavy 474# loads and really confused things, since ABORT commands wouldn't be 475# seen by the drive after an IDENTIFY message in until it had changed 476# to a data I/O phase. 477# 478p_mesgin: 479 mvi 0xe0 call scsisig # CDO|IOO|MSGO 480 mvi A call inb_first # read the 1st message byte 481 mvi REJBYTE,A # save it for the driver 482 483 cmp ALLZEROS,A jne p_mesgin1 484 485# We got a "command complete" message, so put the SCB pointer 486# into the Queue Out, and trigger a completion interrupt. 487# Check status for non zero return and interrupt driver if needed 488# This allows the driver to do a sense command to find out the 489# source of error. We don't bother to post to the QOUTFIFO in 490# the error case since it would require extra work in the kernel 491# driver to ensure that the entry was removed before the command 492# complete code tried processing it. 493 494# First, mark this target as free. 495 and FUNCTION1,0x70,SCBARRAY+1 496 mov A,FUNCTION1 497 xor ACTIVE_A,A 498 499 test SCBARRAY+14,0xff jz status_ok # 0 Status? 500 call inb_last # ack & turn auto PIO back on 501 mvi INTSTAT,STATUS_ERROR # let driver know 502 jmp ITloop 503status_ok: 504 mov QOUTFIFO,SCBPTR 505 mvi INTSTAT,0x2 # CMDCMPLT 506 jmp p_mesgin_done 507 508# Is it an extended message? We only support the synchronous data 509# transfer request message, which will probably be in response to 510# an SDTR message out from us. If it's not an SDTR, reject it - 511# apparently this can be done after any message in byte, according 512# to the SCSI-2 spec. 513# 514# XXX - we should really reject this if we didn't initiate the SDTR 515# negotiation; this may cause problems with unusual devices. 516# 517p_mesgin1: 518 cmp A,1 jne p_mesgin2 # extended message code? 519 520 mvi A call inb_next 521 cmp A,3 jne p_mesginN # extended mesg length = 3 522 mvi A call inb_next 523 cmp A,1 jne p_mesginN # SDTR code 524 525 mvi ARG_1 call inb_next # xfer period 526 mvi ARG_2 call inb_next # REQ/ACK offset 527 mvi INTSTAT,SIGNAL_4 # call driver to convert 528 529 call ndx_sdtr # index sync config for target 530 mov DINDEX,SINDEX 531 mov DINDIR,RETURN_1 # save returned value 532 533 not A # turn off "need sdtr" flag 534 and NEEDSDTR,A 535 536# Even though the SCSI-2 specification says that a device responding 537# to our SDTR message should honor our parameters for transmitting 538# to us, it doesn't seem to work too well in real life. In particular, 539# a lot of CD-ROM and tape units don't function: try using the SDTR 540# parameters the device sent us for both transmitting and receiving. 541# 542 mov SCSIRATE,RETURN_1 543 jmp p_mesgin_done 544 545# Is it a disconnect message? Set a flag in the SCB to remind us 546# and await the bus going free. 547# 548p_mesgin2: 549 cmp A,4 jne p_mesgin3 # disconnect code? 550 551 or SCBARRAY+0,0x4 # set "disconnected" bit 552 jmp p_mesgin_done 553 554# Save data pointers message? Copy working values into the SCB, 555# usually in preparation for a disconnect. 556# 557p_mesgin3: 558 cmp A,2 jne p_mesgin4 # save data pointers code? 559 560 call sg_ram2scb 561 jmp p_mesgin_done 562 563# Restore pointers message? Data pointers are recopied from the 564# SCB anyway at the start of any DMA operation, so the only thing 565# to copy is the scatter-gather values. 566# 567p_mesgin4: 568 cmp A,3 jne p_mesgin5 # restore pointers code? 569 570 call sg_scb2ram 571 jmp p_mesgin_done 572 573# Identify message? For a reconnecting target, this tells us the lun 574# that the reconnection is for - find the correct SCB and switch to it, 575# clearing the "disconnected" bit so we don't "find" it by accident later. 576# 577p_mesgin5: 578 test A,0x80 jz p_mesgin6 # identify message? 579 580 test A,0x78 jnz p_mesginN # !DiscPriv|!LUNTAR|!Reserved 581 582 mov A call findSCB # switch to correct SCB 583 584# If a active message is present after calling findSCB, then either it 585# or the driver is trying to abort the command. Either way, something 586# untoward has happened and we should just leave it alone. 587# 588 test MSG_FLAGS,0x80 jnz p_mesgin_done 589 590 xor SCBARRAY+0,0x4 # clear disconnect bit in SCB 591 mvi RESELECT,0xc0 # make note of IDENTIFY 592 593 call sg_scb2ram # implied restore pointers 594 # required on reselect 595 jmp p_mesgin_done 596 597# Message reject? If we have an outstanding SDTR negotiation, assume 598# that it's a response from the target selecting asynchronous transfer, 599# otherwise just ignore it since we have no clue what it pertains to. 600# 601# XXX - I don't have a device that responds this way. Does this code 602# actually work? 603# 604p_mesgin6: 605 cmp A,7 jne p_mesgin7 # message reject code? 606 607 and FUNCTION1,0x70,SCSIID # outstanding SDTR message? 608 mov A,FUNCTION1 609 test NEEDSDTR,A jz p_mesgin_done # no - ignore rejection 610 611 call ndx_sdtr # note use of asynch xfer 612 mov DINDEX,SINDEX 613 clr DINDIR 614 615 not A # turn off "active sdtr" flag 616 and NEEDSDTR,A 617 618 clr SCSIRATE # select asynch xfer 619 jmp p_mesgin_done 620 621# [ ADD MORE MESSAGE HANDLING HERE ] 622# 623p_mesgin7: 624 625# We have no idea what this message in is, and there's no way 626# to pass it up to the kernel, so we issue a message reject and 627# hope for the best. Since we're now using manual PIO mode to 628# read in the message, there should no longer be a race condition 629# present when we assert ATN. In any case, rejection should be a 630# rare occurrence - signal the driver when it happens. 631# 632p_mesginN: 633 or SINDEX,0x10,SIGSTATE # turn on ATNO 634 call scsisig 635 mvi INTSTAT,SIGNAL_1 # let driver know 636 637 mvi 0x7 call mk_mesg # MESSAGE REJECT message 638 639p_mesgin_done: 640 call inb_last # ack & turn auto PIO back on 641 jmp ITloop 642 643# Bus free phase. It might be useful to interrupt the device 644# driver if we aren't expecting this. For now, make sure that 645# ATN isn't being asserted and look for a new command. 646# 647p_busfree: 648 mvi CLRSINT1,0x40 # CLRATNO 649 clr SIGSTATE 650 jmp start 651 652# Bcopy: number of bytes to transfer should be in A, DINDEX should 653# contain the destination address, and SINDEX should contain the 654# source address. All input parameters are trashed on return. 655# 656bcopy: 657 mov DINDIR,SINDIR 658 dec A 659 cmp ALLZEROS,A jne bcopy 660 ret 661 662# Locking the driver out, build a one-byte message passed in SINDEX 663# if there is no active message already. SINDEX is returned intact. 664# 665mk_mesg: 666 mvi SEQCTL,0x50 # PAUSEDIS|FASTMODE 667 test MSG_FLAGS,0x80 jnz mk_mesg1 # active message? 668 669 mvi MSG_FLAGS,0x80 # if not, there is now 670 mvi MSG_LEN,1 # length = 1 671 mov MSG_START+0,SINDEX # 1-byte message 672 673mk_mesg1: 674 mvi SEQCTL,0x10 # !PAUSEDIS|FASTMODE 675 ret 676 677# Input byte in Automatic PIO mode. The address to store the byte 678# in should be in SINDEX. DINDEX will be used by this routine. 679# 680inb: 681 test SSTAT0,0x2 jz inb # SPIORDY 682 mov DINDEX,SINDEX 683 call one_stcnt # xfer one byte 684 mov DINDIR,SCSIDATL 685inb1: 686 test SSTAT0,0x4 jz inb1 # SDONE - wait to "finish" 687 ret 688 689# Carefully read data in Automatic PIO mode. I first tried this using 690# Manual PIO mode, but it gave me continual underrun errors, probably 691# indicating that I did something wrong, but I feel more secure leaving 692# Automatic PIO on all the time. 693# 694# According to Adaptec's documentation, an ACK is not sent on input from 695# the target until SCSIDATL is read from. So we wait until SCSIDATL is 696# latched (the usual way), then read the data byte directly off the bus 697# using SCSIBUSL. When we have pulled the ATN line, or we just want to 698# acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI 699# spec guarantees that the target will hold the data byte on the bus until 700# we send our ACK. 701# 702# The assumption here is that these are called in a particular sequence, 703# and that REQ is already set when inb_first is called. inb_{first,next} 704# use the same calling convention as inb. 705# 706inb_first: 707 mov DINDEX,SINDEX 708 mov DINDIR,SCSIBUSL ret # read byte directly from bus 709 710inb_next: 711 mov DINDEX,SINDEX # save SINDEX 712 713 call one_stcnt # xfer one byte 714 mov NONE,SCSIDATL # dummy read from latch to ACK 715inb_next1: 716 test SSTAT0,0x4 jz inb_next1 # SDONE 717inb_next2: 718 test SSTAT0,0x2 jz inb_next2 # SPIORDY - wait for next byte 719 mov DINDIR,SCSIBUSL ret # read byte directly from bus 720 721inb_last: 722 call one_stcnt # ACK with dummy read 723 mov NONE,SCSIDATL 724inb_last1: 725 test SSTAT0,0x4 jz inb_last1 # wait for completion 726 ret 727 728# Output byte in Automatic PIO mode. The byte to output should be 729# in SINDEX. If DROPATN's high bit is set, then ATN will be dropped 730# before the byte is output. 731# 732outb: 733 test SSTAT0,0x2 jz outb # SPIORDY 734 call one_stcnt # xfer one byte 735 736 test DROPATN,0x80 jz outb1 737 mvi CLRSINT1,0x40 # CLRATNO 738 clr DROPATN 739outb1: 740 mov SCSIDATL,SINDEX 741outb2: 742 test SSTAT0,0x4 jz outb2 # SDONE 743 ret 744 745# Write the value "1" into the STCNT registers, for Automatic PIO 746# transfers. 747# 748one_stcnt: 749 clr STCNT+2 750 clr STCNT+1 751 mvi STCNT+0,1 ret 752 753# DMA data transfer. HADDR and HCNT must be loaded first, and 754# SINDEX should contain the value to load DFCNTRL with - 0x3d for 755# host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared 756# during initialization. 757# 758dma: 759 mov DFCNTRL,SINDEX 760dma1: 761dma2: 762 test SSTAT0,0x1 jnz dma3 # DMADONE 763 test SSTAT1,0x10 jz dma1 # PHASEMIS, ie. underrun 764 765# We will be "done" DMAing when the transfer count goes to zero, or 766# the target changes the phase (in light of this, it makes sense that 767# the DMA circuitry doesn't ACK when PHASEMIS is active). If we are 768# doing a SCSI->Host transfer, the data FIFO should be flushed auto- 769# magically on STCNT=0 or a phase change, so just wait for FIFO empty 770# status. 771# 772dma3: 773 test SINDEX,0x4 jnz dma5 # DIRECTION 774dma4: 775 test DFSTATUS,0x1 jz dma4 # FIFOFLUSHACK 776 777# Now shut the DMA enables off, and copy STCNT (ie. the underrun 778# amount, if any) to the SCB registers; SG_COUNT will get copied to 779# the SCB's residual S/G count field after sg_advance is called. Make 780# sure that the DMA enables are actually off first lest we get an ILLSADDR. 781# 782dma5: 783 clr DFCNTRL # disable DMA 784dma6: 785 test DFCNTRL,0x38 jnz dma6 # SCSIENACK|SDMAENACK|HDMAENACK 786 787 mvi A,3 788 mvi DINDEX,SCBARRAY+15 789 mvi STCNT call bcopy 790 791 ret 792 793# Common SCSI initialization for selection and reselection. Expects 794# the target SCSI ID to be in the upper four bits of SINDEX, and A's 795# contents are stomped on return. 796# 797initialize: 798 clr SBLKCTL # channel A, !wide 799 and SCSIID,0xf0,SINDEX # target ID 800 and A,0x7,SCSICONF # SCSI_ID_A[210] 801 or SCSIID,A 802 803# Esundry initialization. 804# 805 clr DROPATN 806 clr SIGSTATE 807 808# Turn on Automatic PIO mode now, before we expect to see an REQ 809# from the target. It shouldn't hurt anything to leave it on. Set 810# CLRCHN here before the target has entered a data transfer mode - 811# with synchronous SCSI, if you do it later, you blow away some 812# data in the SCSI FIFO that the target has already sent to you. 813# 814# DFON is a 7870 bit enabling digital filtering of REQ and ACK signals. 815# 816 mvi SXFRCTL0,0x8a # DFON|SPIOEN|CLRCHN 817 818# Set SCSI bus parity checking and the selection timeout value, 819# and enable the hardware selection timer. Set the SELTO interrupt 820# to signal the driver. 821# 822# STPWEN is 7870-specific, enabling an external termination power source. 823# 824 and A,0x38,SCSICONF # PARITY_ENB_A|SEL_TIM_A[10] 825 or SXFRCTL1,0x5,A # ENSTIMER|STPWEN 826 mvi SIMODE1,0x84 # ENSELTIMO|ENSCSIPERR 827 828# Initialize scatter-gather pointers by setting up the working copy 829# in scratch RAM. 830# 831 call sg_scb2ram 832 833# Initialize SCSIRATE with the appropriate value for this target. 834# 835 call ndx_sdtr 836 mov SCSIRATE,SINDIR 837 ret 838 839# Assert that if we've been reselected, then we've seen an IDENTIFY 840# message. 841# 842assert: 843 test RESELECT,0x80 jz assert1 # reselected? 844 test RESELECT,0x40 jnz assert1 # seen IDENTIFY? 845 846 mvi INTSTAT,SIGNAL_2 # no - cause a kernel panic 847 848assert1: 849 ret 850 851# Find out if disconnection is ok from the information the BIOS has left 852# us. The target ID should be in the upper four bits of SINDEX; A will 853# contain either 0x40 (disconnection ok) or 0x00 (disconnection not ok) 854# on exit. 855# 856# This is the only place the target ID is limited to three bits, so we 857# can use the FUNCTION1 register. 858# 859disconnect: 860 and FUNCTION1,0x70,SINDEX # strip off extra just in case 861 mov A,FUNCTION1 862 test DISC_DSB_A,A jz disconnect1 # bit nonzero if DISabled 863 864 clr A ret 865disconnect1: 866 mvi A,0x40 ret 867 868# Locate the SCB matching the target ID in SELID and the lun in the lower 869# three bits of SINDEX, and switch the SCB to it. Have the kernel print 870# a warning message if it can't be found, and generate an ABORT message 871# to the target. We keep the value of the t/c/l that we are trying to find 872# in DINDEX so it is not overwritten during our check to see if we are 873# at the last SCB. 874# 875findSCB: 876 and A,0x7,SINDEX # lun in lower three bits 877 or DINDEX,A,SELID # can I do this? 878 and DINDEX,0xf7 # only channel A implemented 879 880 clr SINDEX 881 882findSCB1: 883 mov A,DINDEX 884 mov SCBPTR,SINDEX # switch to new SCB 885 cmp SCBARRAY+1,A jne findSCB2 # target ID/channel/lun match? 886 test SCBARRAY+0,0x4 jz findSCB2 # should be disconnected 887 888 ret 889 890findSCB2: 891 inc SINDEX 892 mov A,SCBCOUNT 893 cmp SINDEX,A jne findSCB1 894 895 mvi INTSTAT,SIGNAL_3 # not found - signal kernel 896 mvi 0x6 call mk_mesg # ABORT message 897 898 or SINDEX,0x10,SIGSTATE # assert ATNO 899 call scsisig 900 ret 901 902# Make a working copy of the scatter-gather parameters in the SCB. 903# 904sg_scb2ram: 905 mov SG_COUNT,SCBARRAY+2 906 907 mvi A,4 908 mvi DINDEX,SG_NEXT 909 mvi SCBARRAY+3 call bcopy 910 911 mvi SG_NOLOAD,0x80 912 test SCBARRAY+0,0x10 jnz sg_scb2ram1 # don't reload s/g? 913 clr SG_NOLOAD 914 915sg_scb2ram1: 916 ret 917 918# Copying RAM values back to SCB, for Save Data Pointers message. 919# 920sg_ram2scb: 921 mov SCBARRAY+2,SG_COUNT 922 923 mvi A,4 924 mvi DINDEX,SCBARRAY+3 925 mvi SG_NEXT call bcopy 926 927 and SCBARRAY+0,0xef,SCBARRAY+0 928 test SG_NOLOAD,0x80 jz sg_ram2scb1 # reload s/g? 929 or SCBARRAY+0,0x10 930 931sg_ram2scb1: 932 ret 933 934# Load a struct scatter if needed and set up the data address and 935# length. If the working value of the SG count is nonzero, then 936# we need to load a new set of values. 937# 938# This, like the above DMA, assumes a little-endian host data storage. 939# 940sg_load: 941 test SG_COUNT,0xff jz sg_load3 # SG being used? 942 test SG_NOLOAD,0x80 jnz sg_load3 # don't reload s/g? 943 944 clr HCNT+2 945 clr HCNT+1 946 mvi HCNT+0,SG_SIZEOF 947 948 mvi A,4 949 mvi DINDEX,HADDR 950 mvi SG_NEXT call bcopy 951 952 mvi DFCNTRL,0xd # HDMAEN|DIRECTION|FIFORESET 953 954# Wait for DMA from host memory to data FIFO to complete, then disable 955# DMA and wait for it to acknowledge that it's off. 956# 957sg_load1: 958 test DFSTATUS,0x8 jz sg_load1 # HDONE 959 960 clr DFCNTRL # disable DMA 961sg_load2: 962 test DFCNTRL,0x8 jnz sg_load2 # HDMAENACK 963 964# Copy data from FIFO into SCB data pointer and data count. This assumes 965# that the struct scatterlist has this structure (this and sizeof(struct 966# scatterlist) == 12 are asserted in aic7xxx.c): 967# 968# struct scatterlist { 969# char *address; /* four bytes, little-endian order */ 970# ... /* four bytes, ignored */ 971# unsigned short length; /* two bytes, little-endian order */ 972# } 973# 974 975# Not in FreeBSD. the scatter list is only 8 bytes. 976# 977# struct ahc_dma_seg { 978# physaddr addr; /* four bytes, little-endian order */ 979# long len; /* four bytes, little endian order */ 980# }; 981# 982 983 mov SCBARRAY+19,DFDAT # new data address 984 mov SCBARRAY+20,DFDAT 985 mov SCBARRAY+21,DFDAT 986 mov SCBARRAY+22,DFDAT 987 988 mov SCBARRAY+23,DFDAT 989 mov SCBARRAY+24,DFDAT 990 mov SCBARRAY+25,DFDAT 991 mov NONE,DFDAT #Only support 24 bit length. 992 993sg_load3: 994 ret 995 996# Advance the scatter-gather pointers only IF NEEDED. If SG is enabled, 997# and the SCSI transfer count is zero (note that this should be called 998# right after a DMA finishes), then move the working copies of the SG 999# pointer/length along. If the SCSI transfer count is not zero, then 1000# presumably the target is disconnecting - do not reload the SG values 1001# next time. 1002# 1003sg_advance: 1004 test SG_COUNT,0xff jz sg_advance2 # s/g enabled? 1005 1006 test STCNT+0,0xff jnz sg_advance1 # SCSI transfer count nonzero? 1007 test STCNT+1,0xff jnz sg_advance1 1008 test STCNT+2,0xff jnz sg_advance1 1009 1010 clr SG_NOLOAD # reload s/g next time 1011 dec SG_COUNT # one less segment to go 1012 1013 clr A # add sizeof(struct scatter) 1014 add SG_NEXT+0,SG_SIZEOF,SG_NEXT+0 1015 adc SG_NEXT+1,A,SG_NEXT+1 1016 adc SG_NEXT+2,A,SG_NEXT+2 1017 adc SG_NEXT+3,A,SG_NEXT+3 1018 1019 ret 1020 1021sg_advance1: 1022 mvi SG_NOLOAD,0x80 # don't reload s/g next time 1023sg_advance2: 1024 ret 1025 1026# Add the array base SYNCNEG to the target offset (the target address 1027# is in SCSIID), and return the result in SINDEX. The accumulator 1028# contains the 3->8 decoding of the target ID on return. 1029# 1030ndx_sdtr: 1031 shr A,SCSIID,4 1032 and A,0x7 1033 add SINDEX,SYNCNEG,A 1034 1035 and FUNCTION1,0x70,SCSIID # 3-bit target address decode 1036 mov A,FUNCTION1 ret 1037 1038# If we need to negotiate transfer parameters, build the SDTR message 1039# starting at the address passed in SINDEX. DINDEX is modified on return. 1040# 1041mk_sdtr: 1042 mov DINDEX,SINDEX # save SINDEX 1043 1044 call ndx_sdtr 1045 test NEEDSDTR,A jnz mk_sdtr1 # do we need negotiation? 1046 ret 1047 1048mk_sdtr1: 1049 mvi DINDIR,1 # extended message 1050 mvi DINDIR,3 # extended message length = 3 1051 mvi DINDIR,1 # SDTR code 1052 mvi DINDIR,25 # REQ/ACK transfer period 1053 mvi DINDIR,15 # REQ/ACK offset 1054 1055 add MSG_LEN,-MSG_START+0,DINDEX # update message length 1056 ret 1057 1058# Set SCSI bus control signal state. This also saves the last-written 1059# value into a location where the higher-level driver can read it - if 1060# it has to send an ABORT or RESET message, then it needs to know this 1061# so it can assert ATN without upsetting SCSISIGO. The new value is 1062# expected in SINDEX. Change the actual state last to avoid contention 1063# from the driver. 1064# 1065scsisig: 1066 mov SIGSTATE,SINDEX 1067 mov SCSISIGO,SINDEX ret 1068