aic7xxx.seq revision 7118
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, tagged queuing and other 22# optimizations provided by Justin T. Gibbs (gibbs@FreeBSD.org) 23# 24 25VERSION AIC7XXX_SEQ_VER "$Id: aic7xxx.seq,v 1.9 1995/03/07 09:00:44 gibbs Exp $" 26 27SCBMASK = 0x1f 28 29SCSISEQ = 0x00 30SXFRCTL0 = 0x01 31SXFRCTL1 = 0x02 32SCSISIGI = 0x03 33SCSISIGO = 0x03 34SCSIRATE = 0x04 35SCSIID = 0x05 36SCSIDATL = 0x06 37STCNT = 0x08 38STCNT+0 = 0x08 39STCNT+1 = 0x09 40STCNT+2 = 0x0a 41SSTAT0 = 0x0b 42CLRSINT1 = 0x0c 43SSTAT1 = 0x0c 44SIMODE1 = 0x11 45SCSIBUSL = 0x12 46SHADDR = 0x14 47SELID = 0x19 48SBLKCTL = 0x1f 49SEQCTL = 0x60 50A = 0x64 # == ACCUM 51SINDEX = 0x65 52DINDEX = 0x66 53ALLZEROS = 0x6a 54NONE = 0x6a 55SINDIR = 0x6c 56DINDIR = 0x6d 57FUNCTION1 = 0x6e 58HADDR = 0x88 59HCNT = 0x8c 60HCNT+0 = 0x8c 61HCNT+1 = 0x8d 62HCNT+2 = 0x8e 63SCBPTR = 0x90 64INTSTAT = 0x91 65DFCNTRL = 0x93 66DFSTATUS = 0x94 67DFDAT = 0x99 68QINFIFO = 0x9b 69QINCNT = 0x9c 70QOUTFIFO = 0x9d 71 72SCSICONF_A = 0x5a 73SCSICONF_B = 0x5b 74 75# The two reserved bytes at SCBARRAY+1[23] are expected to be set to 76# zero, and the reserved bit in SCBARRAY+0 is used as an internal flag 77# to indicate whether or not to reload scatter-gather parameters after 78# a disconnect. We also use bits 6 & 7 to indicate whether or not to 79# initiate SDTR or WDTR repectively when starting this command. 80# 81SCBARRAY+0 = 0xa0 82 83DISCONNECTED = 0x04 84NEEDDMA = 0x08 85SG_LOAD = 0x10 86TAG_ENB = 0x20 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 = 0x34 161MSG_START+0 = 0x35 162MSG_START+1 = 0x36 163MSG_START+2 = 0x37 164MSG_START+3 = 0x38 165MSG_START+4 = 0x39 166MSG_START+5 = 0x3a 167-MSG_START+0 = 0xcb # 2's complement of MSG_START+0 168 169ARG_1 = 0x4a # sdtr conversion args & return 170BUS_16_BIT = 0x01 171RETURN_1 = 0x4a 172 173SIGSTATE = 0x4b # 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 = 0x4c # load SG pointer/length? 181SG_COUNT = 0x4d # working value of SG count 182SG_NEXT = 0x4e # working value of SG pointer 183SG_NEXT+0 = 0x4e 184SG_NEXT+1 = 0x4f 185SG_NEXT+2 = 0x50 186SG_NEXT+3 = 0x51 187 188SCBCOUNT = 0x52 # the actual number of SCBs 189FLAGS = 0x53 # Device configuration flags 190TWIN_BUS = 0x01 191WIDE_BUS = 0x02 192SENSE = 0x10 193ACTIVE_MSG = 0x20 194IDENTIFY_SEEN = 0x40 195RESELECTED = 0x80 196 197ACTIVE_A = 0x54 198ACTIVE_B = 0x55 199SAVED_TCL = 0x56 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 test SCBARRAY+0,0x20 jnz start_scb 279 and FUNCTION1,0x70,SCBARRAY+1 280 mov A,FUNCTION1 281 test SCBARRAY+1,0x88 jz test_a # Id < 8 && A channel 282 283 test ACTIVE_B,A jnz requeue 284 or ACTIVE_B,A # Mark the current target as busy 285 jmp start_scb 286 287start_sense: 288# Clear the SENSE flag first, then do a normal start_scb 289 and FLAGS,0xef 290 jmp start_scb 291 292# Place the currently active back on the queue for later processing 293requeue: 294 mov QINFIFO, SCBPTR 295 jmp start_nosense 296 297test_a: 298 test ACTIVE_A,A jnz requeue 299 or ACTIVE_A,A # Mark the current target as busy 300 301start_scb: 302 or SCBARRAY+0,NEEDDMA 303 and SINDEX,0xf7,SBLKCTL #Clear the channel select bit 304 and A,0x08,SCBARRAY+1 #Get new channel bit 305 or SINDEX,A 306 mov SBLKCTL,SINDEX # select channel 307 mov SCBARRAY+1 call initialize 308 clr SG_NOLOAD 309 and FLAGS,0x3f # !RESELECTING 310 311# As soon as we get a successful selection, the target should go 312# into the message out phase since we have ATN asserted. Prepare 313# the message to send, locking out the device driver. If the device 314# driver hasn't beaten us with an ABORT or RESET message, then tack 315# on an SDTR negotiation if required. 316# 317# Messages are stored in scratch RAM starting with a flag byte (high bit 318# set means active message), one length byte, and then the message itself. 319# 320 mov SCBARRAY+1 call disconnect # disconnect ok? 321 322 and SINDEX,0x7,SCBARRAY+1 # lun 323 or SINDEX,A # return value from disconnect 324 or SINDEX,0x80 call mk_mesg # IDENTIFY message 325 326 mov A,SINDEX 327 test SCBARRAY+0,0xe0 jz !message # WDTR, SDTR or TAG?? 328 cmp MSG_START+0,A jne !message # did driver beat us? 329 330# Tag Message if Tag enabled in SCB control block. Use SCBPTR as the tag 331# value 332 333mk_tag: 334 mvi DINDEX, MSG_START+1 335 test SCBARRAY+0,TAG_ENB jz mk_tag_done 336 and A,0x23,SCBARRAY+0 337 mov DINDIR,A 338 mov DINDIR,SCBPTR 339 340 add MSG_LEN,-MSG_START+0,DINDEX # update message length 341 jmp !message # Can't do DTR when taged 342 343mk_tag_done: 344 345 mov DINDEX call mk_dtr # build DTR message if needed 346 347!message: 348 349# Enable selection phase as an initiator, and do automatic ATN 350# after the selection. 351# 352 mvi SCSISEQ,0x48 # ENSELO|ENAUTOATNO 353 354# Wait for successful arbitration. The AIC-7770 documentation says 355# that SELINGO indicates successful arbitration, and that it should 356# be used to look for SELDO. However, if the sequencer is paused at 357# just the right time - a parallel fsck(8) on two drives did it for 358# me - then SELINGO can flip back to false before we've seen it. This 359# makes the sequencer sit in the arbitration loop forever. This is 360# Not Good. 361# 362# Therefore, I've added a check in the arbitration loop for SELDO 363# too. This could arguably be made a critical section by disabling 364# pauses, but I don't want to make a potentially infinite loop a CS. 365# I suppose you could fold it into the select loop, too, but since 366# I've been hunting this bug for four days it's kinda like a trophy. 367# 368arbitrate: 369 test SSTAT0,0x40 jnz *select # SELDO 370 test SSTAT0,0x10 jz arbitrate # SELINGO 371 372# Wait for a successful selection. If the hardware selection 373# timer goes off, then the driver gets the interrupt, so we don't 374# need to worry about it. 375# 376select: 377 test SSTAT0,0x40 jz select # SELDO 378 jmp *select 379 380# Reselection is being initiated by a target - we've seen the BSY 381# line driven active, and we didn't do it! Enable the reselection 382# hardware, and wait for it to finish. Make a note that we've been 383# reselected, but haven't seen an IDENTIFY message from the target 384# yet. 385# 386reselect: 387 mvi SCSISEQ,0x10 # ENRSELI 388 389reselect1: 390 test SSTAT0,0x20 jz reselect1 # SELDI 391 mov SELID call initialize 392 393 and FLAGS,0x3f # reselected, no IDENTIFY 394 or FLAGS,RESELECTED 395 396# After the [re]selection, make sure that the [re]selection enable 397# bit is off. This chip is flaky enough without extra things 398# turned on. Also clear the BUSFREE bit in SSTAT1 since we'll be 399# using it shortly. 400# 401*select: 402 clr SCSISEQ 403 mvi CLRSINT1,0x8 # CLRBUSFREE 404 405# Main loop for information transfer phases. If BSY is false, then 406# we have a bus free condition, expected or not. Otherwise, wait 407# for the target to assert REQ before checking MSG, C/D and I/O 408# for the bus phase. 409# 410# We can't simply look at the values of SCSISIGI here (if we want 411# to do synchronous data transfer), because the target won't assert 412# REQ if it's already sent us some data that we haven't acknowledged 413# yet. 414# 415ITloop: 416 test SSTAT1,0x8 jnz p_busfree # BUSFREE 417 test SSTAT1,0x1 jz ITloop # REQINIT 418 419 and A,0xe0,SCSISIGI # CDI|IOI|MSGI 420 421 cmp ALLZEROS,A je p_dataout 422 cmp A,0x40 je p_datain 423 cmp A,0x80 je p_command 424 cmp A,0xc0 je p_status 425 cmp A,0xa0 je p_mesgout 426 cmp A,0xe0 je p_mesgin 427 428 mvi INTSTAT,BAD_PHASE # unknown - signal driver 429 430p_dataout: 431 mvi 0 call scsisig # !CDO|!IOO|!MSGO 432 call assert 433 call sg_load 434 435 mvi DINDEX,HADDR 436 mvi SCBARRAY+19 call bcopy_4 437 438# mvi DINDEX,HCNT # implicit since HCNT is next to HADDR 439 mvi SCBARRAY+23 call bcopy_3 440 441 mvi DINDEX,STCNT 442 mvi SCBARRAY+23 call bcopy_3 443 444 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 445 # DIRECTION|FIFORESET 446 447# After a DMA finishes, save the final transfer pointer and count 448# back into the SCB, in case a device disconnects in the middle of 449# a transfer. Use SHADDR and STCNT instead of HADDR and HCNT, since 450# it's a reflection of how many bytes were transferred on the SCSI 451# (as opposed to the host) bus. 452# 453 mvi DINDEX,SCBARRAY+23 454 mvi STCNT call bcopy_3 455 456 mvi DINDEX,SCBARRAY+19 457 mvi SHADDR call bcopy_4 458 459 call sg_advance 460 mov SCBARRAY+18,SG_COUNT # residual S/G count 461 462 jmp ITloop 463 464p_datain: 465 mvi 0x40 call scsisig # !CDO|IOO|!MSGO 466 call assert 467 call sg_load 468 469 mvi DINDEX,HADDR 470 mvi SCBARRAY+19 call bcopy_4 471 472# mvi DINDEX,HCNT # implicit since HCNT is next to HADDR 473 mvi SCBARRAY+23 call bcopy_3 474 475 mvi DINDEX,STCNT 476 mvi SCBARRAY+23 call bcopy_3 477 478 mvi 0x39 call dma # SCSIEN|SDMAEN|HDMAEN| 479 # !DIRECTION|FIFORESET 480 mvi DINDEX,SCBARRAY+23 481 mvi STCNT call bcopy_3 482 483 mvi DINDEX,SCBARRAY+19 484 mvi SHADDR call bcopy_4 485 486 call sg_advance 487 mov SCBARRAY+18,SG_COUNT # residual S/G count 488 489 jmp ITloop 490 491# Command phase. Set up the DMA registers and let 'er rip - the 492# two bytes after the SCB SCSI_cmd_length are zeroed by the driver, 493# so we can copy those three bytes directly into HCNT. 494# 495p_command: 496 mvi 0x80 call scsisig # CDO|!IOO|!MSGO 497 call assert 498 499 mvi DINDEX,HADDR 500 mvi SCBARRAY+7 call bcopy_4 501 502# mvi DINDEX,HCNT # implicit since HCNT is next to HADDR 503 mvi SCBARRAY+11 call bcopy_3 504 505 mvi DINDEX,STCNT 506 mvi SCBARRAY+11 call bcopy_3 507 508 mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| 509 # DIRECTION|FIFORESET 510 jmp ITloop 511 512# Status phase. Wait for the data byte to appear, then read it 513# and store it into the SCB. 514# 515p_status: 516 mvi 0xc0 call scsisig # CDO|IOO|!MSGO 517 518 mvi SCBARRAY+14 call inb 519 jmp ITloop 520 521# Message out phase. If there is no active message, but the target 522# took us into this phase anyway, build a no-op message and send it. 523# 524p_mesgout: 525 mvi 0xa0 call scsisig # CDO|!IOO|MSGO 526 mvi 0x8 call mk_mesg # build NOP message 527 528# Set up automatic PIO transfer from MSG_START. Bit 3 in 529# SXFRCTL0 (SPIOEN) is already on. 530# 531 mvi SINDEX,MSG_START+0 532 mov DINDEX,MSG_LEN 533 clr A 534 535# When target asks for a byte, drop ATN if it's the last one in 536# the message. Otherwise, keep going until the message is exhausted. 537# (We can't use outb for this since it wants the input in SINDEX.) 538# 539# Keep an eye out for a phase change, in case the target issues 540# a MESSAGE REJECT. 541# 542p_mesgout2: 543 test SSTAT0,0x2 jz p_mesgout2 # SPIORDY 544 test SSTAT1,0x10 jnz p_mesgout6 # PHASEMIS 545 546 cmp DINDEX,1 jne p_mesgout3 # last byte? 547 mvi CLRSINT1,0x40 # CLRATNO - drop ATN 548 549# Write a byte to the SCSI bus. The AIC-7770 refuses to automatically 550# send ACKs in automatic PIO or DMA mode unless you make sure that the 551# "expected" bus phase in SCSISIGO matches the actual bus phase. This 552# behaviour is completely undocumented and caused me several days of 553# grief. 554# 555# After plugging in different drives to test with and using a longer 556# SCSI cable, I found that I/O in Automatic PIO mode ceased to function, 557# especially when transferring >1 byte. It seems to be much more stable 558# if STCNT is set to one before the transfer, and SDONE (in SSTAT0) is 559# polled for transfer completion - for both output _and_ input. The 560# only theory I have is that SPIORDY doesn't drop right away when SCSIDATL 561# is accessed (like the documentation says it does), and that on a longer 562# cable run, the sequencer code was fast enough to loop back and see 563# an SPIORDY that hadn't dropped yet. 564# 565p_mesgout3: 566 call one_stcnt 567 mov SCSIDATL,SINDIR 568 569p_mesgout4: 570 test SSTAT0,0x4 jz p_mesgout4 # SDONE 571 dec DINDEX 572 inc A 573 cmp MSG_LEN,A jne p_mesgout2 574 575# If the next bus phase after ATN drops is a message out, it means 576# that the target is requesting that the last message(s) be resent. 577# 578p_mesgout5: 579 test SSTAT1,0x8 jnz p_mesgout6 # BUSFREE 580 test SSTAT1,0x1 jz p_mesgout5 # REQINIT 581 582 and A,0xe0,SCSISIGI # CDI|IOI|MSGI 583 cmp A,0xa0 jne p_mesgout6 584 mvi 0x10 call scsisig # ATNO - re-assert ATN 585 586 jmp ITloop 587 588p_mesgout6: 589 mvi CLRSINT1,0x40 # CLRATNO - in case of PHASEMIS 590 and FLAGS,0xdf # no active msg 591 jmp ITloop 592 593# Message in phase. Bytes are read using Automatic PIO mode, but not 594# using inb. This alleviates a race condition, namely that if ATN had 595# to be asserted under Automatic PIO mode, it had to beat the SCSI 596# circuitry sending an ACK to the target. This showed up under heavy 597# loads and really confused things, since ABORT commands wouldn't be 598# seen by the drive after an IDENTIFY message in until it had changed 599# to a data I/O phase. 600# 601p_mesgin: 602 mvi 0xe0 call scsisig # CDO|IOO|MSGO 603 mvi A call inb_first # read the 1st message byte 604 mvi REJBYTE,A # save it for the driver 605 606 cmp ALLZEROS,A jne p_mesgin1 607 608# We got a "command complete" message, so put the SCB pointer 609# into the Queue Out, and trigger a completion interrupt. 610# Check status for non zero return and interrupt driver if needed 611# This allows the driver to interpret errors only when they occur 612# instead of always uploading the scb. If the status is SCSI_CHECK, 613# the driver will download a new scb requesting sense, to replace 614# the old one and the sequencer code will imediately jump to start 615# working on it. If the kernel driver does not wish to request sense, 616# the sequencer program counter is incremented by 1, preventing another run 617# on the current SCB and the command is allowed to complete. We don't 618# bother to post to the QOUTFIFO in the error case since it would require 619# extra work in the kernel driver to ensure that the entry was removed 620# before the command complete code tried processing it. 621 622 test SCBARRAY+14,0xff jz status_ok # 0 Status? 623 mvi INTSTAT,BAD_STATUS # let driver know 624 test FLAGS,SENSE jz status_ok 625 jmp p_mesgin_done 626 627status_ok: 628 629# First, mark this target as free. 630 test SCBARRAY+0,0x20 jnz complete # Tagged command 631 and FUNCTION1,0x70,SCBARRAY+1 632 mov A,FUNCTION1 633 test SCBARRAY+1,0x88 jz clear_a 634 xor ACTIVE_B,A 635 jmp complete 636 637clear_a: 638 xor ACTIVE_A,A 639 640complete: 641 mov QOUTFIFO,SCBPTR 642 mvi INTSTAT,0x02 # CMDCMPLT 643 jmp p_mesgin_done 644 645# Is it an extended message? We only support the synchronous and wide data 646# transfer request messages, which will probably be in response to 647# WDTR or SDTR message outs from us. If it's not SDTR or WDTR, reject it - 648# apparently this can be done after any message in byte, according 649# to the SCSI-2 spec. 650# 651p_mesgin1: 652 cmp A,1 jne p_mesgin2 # extended message code? 653 654 mvi ARG_1 call inb_next # extended message length 655 mvi A call inb_next # extended message code 656 657 cmp A,1 je p_mesginSDTR # Syncronous negotiation message 658 cmp A,3 je p_mesginWDTR # Wide negotiation message 659 jmp p_mesginN 660 661p_mesginWDTR: 662 cmp ARG_1,2 jne p_mesginN # extended mesg length = 2 663 mvi A call inb_next # Width of bus 664 mvi INTSTAT,MSG_WDTR # let driver know 665 test RETURN_1,0x80 jz p_mesgin_done# Do we need to send WDTR? 666 667# We didn't initiate the wide negotiation, so we must respond to the request 668 and RETURN_1,0x7f # Clear the SEND_WDTR Flag 669 or FLAGS,ACTIVE_MSG 670 mvi DINDEX,MSG_START+0 671 mvi MSG_START+0 call mk_wdtr # build WDTR message 672 or SINDEX,0x10,SIGSTATE # turn on ATNO 673 call scsisig 674 jmp p_mesgin_done 675 676p_mesginSDTR: 677 cmp ARG_1,3 jne p_mesginN # extended mesg length = 3 678 mvi ARG_1 call inb_next # xfer period 679 mvi A call inb_next # REQ/ACK offset 680 mvi INTSTAT,MSG_SDTR # call driver to convert 681 682 test RETURN_1,0x80 jz p_mesgin_done# Do we need to mk_sdtr? 683 684 or FLAGS,ACTIVE_MSG 685 mvi DINDEX, MSG_START+0 686 mvi MSG_START+0 call mk_sdtr 687 or SINDEX,0x10,SIGSTATE # turn on ATNO 688 call scsisig 689 jmp p_mesgin_done 690 691# Is it a disconnect message? Set a flag in the SCB to remind us 692# and await the bus going free. 693# 694p_mesgin2: 695 cmp A,4 jne p_mesgin3 # disconnect code? 696 697 or SCBARRAY+0,0x4 # set "disconnected" bit 698 jmp p_mesgin_done 699 700# Save data pointers message? Copy working values into the SCB, 701# usually in preparation for a disconnect. 702# 703p_mesgin3: 704 cmp A,2 jne p_mesgin4 # save data pointers code? 705 706 call sg_ram2scb 707 jmp p_mesgin_done 708 709# Restore pointers message? Data pointers are recopied from the 710# SCB anyway at the start of any DMA operation, so the only thing 711# to copy is the scatter-gather values. 712# 713p_mesgin4: 714 cmp A,3 jne p_mesgin5 # restore pointers code? 715 716 call sg_scb2ram 717 jmp p_mesgin_done 718 719# Identify message? For a reconnecting target, this tells us the lun 720# that the reconnection is for - find the correct SCB and switch to it, 721# clearing the "disconnected" bit so we don't "find" it by accident later. 722# 723p_mesgin5: 724 test A,0x80 jz p_mesgin6 # identify message? 725 726 test A,0x78 jnz p_mesginN # !DiscPriv|!LUNTAR|!Reserved 727 728 and A,0x07 # lun in lower three bits 729 or SAVED_TCL,A,SELID 730 and SAVED_TCL,0xf7 731 and A,0x08,SBLKCTL # B Channel?? 732 or SAVED_TCL,A 733 call inb_last # Ack 734 735# Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message. 736# If we get one, we use the tag returned to switch to the proper 737# SCB. Otherwise, we just use the findSCB method. 738p_mesgin5_loop: 739 test SSTAT1,0x08 jnz use_findSCB # BUSFREE 740 test SSTAT1,0x01 jz p_mesgin5_loop # REQINIT 741 and A,0xe0,SCSISIGI # CDI|IOI|MSGI 742 cmp A,0xe0 jne use_findSCB # Still p_mesgin? 743 mvi A call inb_first 744 cmp A,0x20 je get_tag # Simple Tag message? 745use_findSCB: 746 mov ALLZEROS call findSCB # Have to search 747 748# If a active message is present after calling findSCB, then either it 749# or the driver is trying to abort the command. Either way, something 750# untoward has happened and we should just leave it alone. 751# 752setup_SCB: 753 test FLAGS,ACTIVE_MSG jnz p_mesgin_done 754 755 and SCBARRAY+0,0xfb # clear disconnect bit in SCB 756 or FLAGS,0xc0 # make note of IDENTIFY 757 758 call sg_scb2ram # implied restore pointers 759 # required on reselect 760 jmp ITloop 761 762get_tag: 763 mvi A call inb_next 764 test A,0xf0 jnz abort_tag # Tag in range? 765 mov SCBPTR,A 766 mov A,SAVED_TCL 767 cmp SCBARRAY+1,A jne abort_tag 768 test SCBARRAY+0,TAG_ENB jz abort_tag 769 call inb_last 770 jmp setup_SCB 771 772# Message reject? Let the kernel driver handle this. If we have an 773# outstanding WDTR or SDTR negotiation, assume that it's a response from 774# the target selecting 8bit or asynchronous transfer, otherwise just ignore 775# it since we have no clue what it pertains to. 776# 777p_mesgin6: 778 cmp A,7 jne p_mesgin7 # message reject code? 779 780 mvi INTSTAT, MSG_REJECT 781 jmp p_mesgin_done 782 783# [ ADD MORE MESSAGE HANDLING HERE ] 784# 785p_mesgin7: 786 787# We have no idea what this message in is, and there's no way 788# to pass it up to the kernel, so we issue a message reject and 789# hope for the best. Since we're now using manual PIO mode to 790# read in the message, there should no longer be a race condition 791# present when we assert ATN. In any case, rejection should be a 792# rare occurrence - signal the driver when it happens. 793# 794p_mesginN: 795 or SINDEX,0x10,SIGSTATE # turn on ATNO 796 call scsisig 797 mvi INTSTAT,SEND_REJECT # let driver know 798 799 mvi 0x7 call mk_mesg # MESSAGE REJECT message 800 801p_mesgin_done: 802 call inb_last # ack & turn auto PIO back on 803 jmp ITloop 804 805abort_tag: 806 or SINDEX,0x10,SIGSTATE # turn on ATNO 807 call scsisig 808# mvi INTSTAT,ABORT_TAG # let driver know 809 mvi 0xd call mk_mesg # ABORT TAG message 810 jmp p_mesgin_done 811 812# Bus free phase. It might be useful to interrupt the device 813# driver if we aren't expecting this. For now, make sure that 814# ATN isn't being asserted and look for a new command. 815# 816p_busfree: 817 mvi CLRSINT1,0x40 # CLRATNO 818 clr SIGSTATE 819 jmp start 820 821# Instead of a generic bcopy routine that requires an argument, we unroll 822# the two cases that are actually used, and call them explicitly. This 823# not only reduces the overhead of doing a bcopy by 2/3rds, but ends up 824# saving space in the program since you don't have to put the argument 825# into the accumulator before the call. Both functions expect DINDEX to 826# contain the destination address and SINDEX to contain the source 827# address. 828bcopy_3: 829 mov DINDIR,SINDIR 830 mov DINDIR,SINDIR 831 mov DINDIR,SINDIR ret 832 833bcopy_4: 834 mov DINDIR,SINDIR 835 mov DINDIR,SINDIR 836 mov DINDIR,SINDIR 837 mov DINDIR,SINDIR ret 838 839 840# Locking the driver out, build a one-byte message passed in SINDEX 841# if there is no active message already. SINDEX is returned intact. 842# 843mk_mesg: 844 mvi SEQCTL,0x50 # PAUSEDIS|FASTMODE 845 test FLAGS,ACTIVE_MSG jnz mk_mesg1 # active message? 846 847 or FLAGS,ACTIVE_MSG # if not, there is now 848 mvi MSG_LEN,1 # length = 1 849 mov MSG_START+0,SINDEX # 1-byte message 850 851mk_mesg1: 852 mvi SEQCTL,0x10 ret # !PAUSEDIS|FASTMODE 853 854# Input byte in Automatic PIO mode. The address to store the byte 855# in should be in SINDEX. DINDEX will be used by this routine. 856# 857inb: 858 test SSTAT0,0x2 jz inb # SPIORDY 859 mov DINDEX,SINDEX 860 call one_stcnt # xfer one byte 861 mov DINDIR,SCSIDATL 862inb1: 863 test SSTAT0,0x4 jz inb1 # SDONE - wait to "finish" 864 ret 865 866# Carefully read data in Automatic PIO mode. I first tried this using 867# Manual PIO mode, but it gave me continual underrun errors, probably 868# indicating that I did something wrong, but I feel more secure leaving 869# Automatic PIO on all the time. 870# 871# According to Adaptec's documentation, an ACK is not sent on input from 872# the target until SCSIDATL is read from. So we wait until SCSIDATL is 873# latched (the usual way), then read the data byte directly off the bus 874# using SCSIBUSL. When we have pulled the ATN line, or we just want to 875# acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI 876# spec guarantees that the target will hold the data byte on the bus until 877# we send our ACK. 878# 879# The assumption here is that these are called in a particular sequence, 880# and that REQ is already set when inb_first is called. inb_{first,next} 881# use the same calling convention as inb. 882# 883inb_first: 884 mov DINDEX,SINDEX 885 mov DINDIR,SCSIBUSL ret # read byte directly from bus 886 887inb_next: 888 mov DINDEX,SINDEX # save SINDEX 889 890 call one_stcnt # xfer one byte 891 mov NONE,SCSIDATL # dummy read from latch to ACK 892inb_next1: 893 test SSTAT0,0x4 jz inb_next1 # SDONE 894inb_next2: 895 test SSTAT0,0x2 jz inb_next2 # SPIORDY - wait for next byte 896 mov DINDIR,SCSIBUSL ret # read byte directly from bus 897 898inb_last: 899 call one_stcnt # ACK with dummy read 900 mov NONE,SCSIDATL 901inb_last1: 902 test SSTAT0,0x4 jz inb_last1 # wait for completion 903 ret 904 905# Output byte in Automatic PIO mode. The byte to output should be 906# in SINDEX. If DROPATN's high bit is set, then ATN will be dropped 907# before the byte is output. 908# 909outb: 910 test SSTAT0,0x2 jz outb # SPIORDY 911 call one_stcnt # xfer one byte 912 913 test DROPATN,0x80 jz outb1 914 mvi CLRSINT1,0x40 # CLRATNO 915 clr DROPATN 916outb1: 917 mov SCSIDATL,SINDEX 918outb2: 919 test SSTAT0,0x4 jz outb2 # SDONE 920 ret 921 922# Write the value "1" into the STCNT registers, for Automatic PIO 923# transfers. 924# 925one_stcnt: 926 clr STCNT+2 927 clr STCNT+1 928 mvi STCNT+0,1 ret 929 930# DMA data transfer. HADDR and HCNT must be loaded first, and 931# SINDEX should contain the value to load DFCNTRL with - 0x3d for 932# host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared 933# during initialization. 934# 935dma: 936 mov DFCNTRL,SINDEX 937dma1: 938dma2: 939 test SSTAT0,0x1 jnz dma3 # DMADONE 940 test SSTAT1,0x10 jz dma1 # PHASEMIS, ie. underrun 941 942# We will be "done" DMAing when the transfer count goes to zero, or 943# the target changes the phase (in light of this, it makes sense that 944# the DMA circuitry doesn't ACK when PHASEMIS is active). If we are 945# doing a SCSI->Host transfer, the data FIFO should be flushed auto- 946# magically on STCNT=0 or a phase change, so just wait for FIFO empty 947# status. 948# 949dma3: 950 test SINDEX,0x4 jnz dma5 # DIRECTION 951dma4: 952 test DFSTATUS,0x1 jz dma4 # !FIFOEMP 953 954# Now shut the DMA enables off, and copy STCNT (ie. the underrun 955# amount, if any) to the SCB registers; SG_COUNT will get copied to 956# the SCB's residual S/G count field after sg_advance is called. Make 957# sure that the DMA enables are actually off first lest we get an ILLSADDR. 958# 959dma5: 960 clr DFCNTRL # disable DMA 961dma6: 962 test DFCNTRL,0x38 jnz dma6 # SCSIENACK|SDMAENACK|HDMAENACK 963 964 mvi DINDEX,SCBARRAY+15 965 mvi STCNT call bcopy_3 966 967 ret 968 969# Common SCSI initialization for selection and reselection. Expects 970# the target SCSI ID to be in the upper four bits of SINDEX, and A's 971# contents are stomped on return. 972# 973initialize: 974 and SINDEX,0xf0 # Get target ID 975 and A,0x0f,SCSIID 976 or SINDEX,A 977 mov SCSIID,SINDEX 978 979# Esundry initialization. 980# 981 clr DROPATN 982 clr SIGSTATE 983 984# Turn on Automatic PIO mode now, before we expect to see a REQ 985# from the target. It shouldn't hurt anything to leave it on. Set 986# CLRCHN here before the target has entered a data transfer mode - 987# with synchronous SCSI, if you do it later, you blow away some 988# data in the SCSI FIFO that the target has already sent to you. 989# 990 mvi SXFRCTL0,0x8a # DFON|SPIOEN|CLRCHN 991 992# Initialize scatter-gather pointers by setting up the working copy 993# in scratch RAM. 994# 995 call sg_scb2ram 996 997# Initialize SCSIRATE with the appropriate value for this target. 998# 999 call ndx_dtr 1000 mov SCSIRATE,SINDIR ret 1001 1002# Assert that if we've been reselected, then we've seen an IDENTIFY 1003# message. 1004# 1005assert: 1006 test FLAGS,RESELECTED jz assert1 # reselected? 1007 test FLAGS,IDENTIFY_SEEN jnz assert1 # seen IDENTIFY? 1008 1009 mvi INTSTAT,NO_IDENT # no - cause a kernel panic 1010 1011assert1: 1012 ret 1013 1014# Find out if disconnection is ok from the information the BIOS has left 1015# us. The tcl from SCBARRAY+1 should be in SINDEX; A will 1016# contain either 0x40 (disconnection ok) or 0x00 (disconnection not ok) 1017# on exit. 1018# 1019# To allow for wide or twin busses, we check the upper bit of the target ID 1020# and the channel ID and look at the appropriate disconnect register. 1021# 1022disconnect: 1023 and FUNCTION1,0x70,SINDEX # strip off extra just in case 1024 mov A,FUNCTION1 1025 test SINDEX, 0x88 jz disconnect_a 1026 1027 test DISC_DSB_B,A jz disconnect1 # bit nonzero if DISabled 1028 clr A ret 1029 1030disconnect_a: 1031 test DISC_DSB_A,A jz disconnect1 # bit nonzero if DISabled 1032 clr A ret 1033 1034disconnect1: 1035 mvi A,0x40 ret 1036 1037# Locate the SCB matching the target ID/channel/lun in SAVED_TCL and switch 1038# the SCB to it. Have the kernel print a warning message if it can't be 1039# found, and generate an ABORT message to the target. SINDEX should be 1040# cleared on call. 1041# 1042findSCB: 1043 mov A,SAVED_TCL 1044 mov SCBPTR,SINDEX # switch to new SCB 1045 cmp SCBARRAY+1,A jne findSCB1 # target ID/channel/lun match? 1046 test SCBARRAY+0,0x4 jz findSCB1 # should be disconnected 1047 ret 1048 1049findSCB1: 1050 inc SINDEX 1051 mov A,SCBCOUNT 1052 cmp SINDEX,A jne findSCB 1053 1054 mvi INTSTAT,NO_MATCH # not found - signal kernel 1055 mvi 0x6 call mk_mesg # ABORT message 1056 1057 or SINDEX,0x10,SIGSTATE # assert ATNO 1058 call scsisig 1059 ret 1060 1061# Make a working copy of the scatter-gather parameters in the SCB. 1062# 1063sg_scb2ram: 1064 mov SG_COUNT,SCBARRAY+2 1065 1066 mvi DINDEX,SG_NEXT 1067 mvi SCBARRAY+3 call bcopy_4 1068 1069 mvi SG_NOLOAD,0x80 1070 test SCBARRAY+0,0x10 jnz sg_scb2ram1 # don't reload s/g? 1071 clr SG_NOLOAD 1072 1073sg_scb2ram1: 1074 ret 1075 1076# Copying RAM values back to SCB, for Save Data Pointers message. 1077# 1078sg_ram2scb: 1079 mov SCBARRAY+2,SG_COUNT 1080 1081 mvi DINDEX,SCBARRAY+3 1082 mvi SG_NEXT call bcopy_4 1083 1084 and SCBARRAY+0,0xef,SCBARRAY+0 1085 test SG_NOLOAD,0x80 jz sg_ram2scb1 # reload s/g? 1086 or SCBARRAY+0,SG_LOAD 1087 1088sg_ram2scb1: 1089 ret 1090 1091# Load a struct scatter if needed and set up the data address and 1092# length. If the working value of the SG count is nonzero, then 1093# we need to load a new set of values. 1094# 1095# This, like the above DMA, assumes a little-endian host data storage. 1096# 1097sg_load: 1098 test SG_COUNT,0xff jz sg_load3 # SG being used? 1099 test SG_NOLOAD,0x80 jnz sg_load3 # don't reload s/g? 1100 1101 clr HCNT+2 1102 clr HCNT+1 1103 mvi HCNT+0,SG_SIZEOF 1104 1105 mvi DINDEX,HADDR 1106 mvi SG_NEXT call bcopy_4 1107 1108 mvi DFCNTRL,0xd # HDMAEN|DIRECTION|FIFORESET 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# 1113sg_load1: 1114 test DFSTATUS,0x8 jz sg_load1 # HDONE 1115 1116 clr DFCNTRL # disable DMA 1117sg_load2: 1118 test DFCNTRL,0x8 jnz sg_load2 # HDMAENACK 1119 1120# Copy data from FIFO into SCB data pointer and data count. This assumes 1121# that the struct scatterlist has this structure (this and sizeof(struct 1122# scatterlist) == 12 are asserted in aic7xxx.c): 1123# 1124# struct scatterlist { 1125# char *address; /* four bytes, little-endian order */ 1126# ... /* four bytes, ignored */ 1127# unsigned short length; /* two bytes, little-endian order */ 1128# } 1129# 1130 1131# Not in FreeBSD. the scatter list is only 8 bytes. 1132# 1133# struct ahc_dma_seg { 1134# physaddr addr; /* four bytes, little-endian order */ 1135# long len; /* four bytes, little endian order */ 1136# }; 1137# 1138 1139 mov SCBARRAY+19,DFDAT # new data address 1140 mov SCBARRAY+20,DFDAT 1141 mov SCBARRAY+21,DFDAT 1142 mov SCBARRAY+22,DFDAT 1143 1144# For Linux, we must throw away four bytes since there is a 32bit gap 1145# in the middle of a struct scatterlist 1146# mov NONE,DFDAT 1147# mov NONE,DFDAT 1148# mov NONE,DFDAT 1149# mov NONE,DFDAT 1150 1151 mov SCBARRAY+23,DFDAT 1152 mov SCBARRAY+24,DFDAT 1153 mov SCBARRAY+25,DFDAT #Only support 24 bit length. 1154 1155sg_load3: 1156 ret 1157 1158# Advance the scatter-gather pointers only IF NEEDED. If SG is enabled, 1159# and the SCSI transfer count is zero (note that this should be called 1160# right after a DMA finishes), then move the working copies of the SG 1161# pointer/length along. If the SCSI transfer count is not zero, then 1162# presumably the target is disconnecting - do not reload the SG values 1163# next time. 1164# 1165sg_advance: 1166 test SG_COUNT,0xff jz sg_advance2 # s/g enabled? 1167 1168 test STCNT+0,0xff jnz sg_advance1 # SCSI transfer count nonzero? 1169 test STCNT+1,0xff jnz sg_advance1 1170 test STCNT+2,0xff jnz sg_advance1 1171 1172 clr SG_NOLOAD # reload s/g next time 1173 dec SG_COUNT # one less segment to go 1174 1175 clr A # add sizeof(struct scatter) 1176 add SG_NEXT+0,SG_SIZEOF,SG_NEXT+0 1177 adc SG_NEXT+1,A,SG_NEXT+1 1178 adc SG_NEXT+2,A,SG_NEXT+2 1179 adc SG_NEXT+3,A,SG_NEXT+3 ret 1180 1181sg_advance1: 1182 mvi SG_NOLOAD,0x80 # don't reload s/g next time 1183sg_advance2: 1184 ret 1185 1186# Add the array base SYNCNEG to the target offset (the target address 1187# is in SCSIID), and return the result in SINDEX. The accumulator 1188# contains the 3->8 decoding of the target ID on return. 1189# 1190ndx_dtr: 1191 shr A,SCSIID,4 1192 test SBLKCTL,0x08 jz ndx_dtr_2 1193 or A,0x08 # Channel B entries add 8 1194ndx_dtr_2: 1195 add SINDEX,SYNCNEG,A 1196 1197 and FUNCTION1,0x70,SCSIID # 3-bit target address decode 1198 mov A,FUNCTION1 ret 1199 1200# If we need to negotiate transfer parameters, build the WDTR or SDTR message 1201# starting at the address passed in SINDEX. DINDEX is modified on return. 1202# The SCSI-II spec requires that Wide negotiation occur first and you can 1203# only negotiat one or the other at a time otherwise in the event of a message 1204# reject, you wouldn't be able to tell which message was the culpret. 1205# 1206mk_dtr: 1207 mov DINDEX,SINDEX # save SINDEX 1208 1209 test SCBARRAY+0,NEEDWDTR jnz mk_wdtr_16bit 1210 jmp mk_sdtr 1211 1212mk_wdtr_16bit: 1213 mvi ARG_1,BUS_16_BIT 1214mk_wdtr: 1215 mvi DINDIR,1 # extended message 1216 mvi DINDIR,2 # extended message length = 2 1217 mvi DINDIR,3 # WDTR code 1218 mov DINDIR,ARG_1 # bus width 1219 1220 add MSG_LEN,-MSG_START+0,DINDEX ret # update message length 1221 1222mk_sdtr: 1223 mvi DINDIR,1 # extended message 1224 mvi DINDIR,3 # extended message length = 3 1225 mvi DINDIR,1 # SDTR code 1226 call sdtr_to_rate 1227 mov DINDIR,RETURN_1 # REQ/ACK transfer period 1228 and DINDIR,0xf,SINDIR # Sync Offset 1229 1230 add MSG_LEN,-MSG_START+0,DINDEX ret # update message length 1231 1232# Set SCSI bus control signal state. This also saves the last-written 1233# value into a location where the higher-level driver can read it - if 1234# it has to send an ABORT or RESET message, then it needs to know this 1235# so it can assert ATN without upsetting SCSISIGO. The new value is 1236# expected in SINDEX. Change the actual state last to avoid contention 1237# from the driver. 1238# 1239scsisig: 1240 mov SIGSTATE,SINDEX 1241 mov SCSISIGO,SINDEX ret 1242 1243sdtr_to_rate: 1244 call ndx_dtr # index scratch space for target 1245 shr A,SINDIR,0x4 1246 dec SINDEX #Preserve SINDEX 1247 and A,0x7 1248 clr RETURN_1 1249sdtr_to_rate_loop: 1250 test A,0x0f jz sdtr_to_rate_done 1251 add RETURN_1,0x18 1252 dec A 1253 jmp sdtr_to_rate_loop 1254sdtr_to_rate_done: 1255 shr RETURN_1,0x2 1256 add RETURN_1,0x18 ret 1257