ref: 6bb619c8db2867ddd9cd19c0aec05065f5ee0cae
dir: /os/pc/sd53c8xx.n/
// NCR 53c8xx driver for Plan 9
// Nigel Roles (nigel@9fs.org)
//
// Microcode
//
// 27/5/02 Fixed problems with transfers >= 256 * 512
//
// 13/3/01 Fixed microcode to support targets > 7
//
extern scsi_id_buf
extern msg_out_buf
extern cmd_buf
extern data_buf
extern status_buf
extern msgin_buf
extern dsa_0
extern dsa_1
extern dsa_head
extern ssid_mask
SIR_MSG_IO_COMPLETE = 0
error_not_cmd_complete = 1
error_disconnected = 2
error_reselected = 3
error_unexpected_phase = 4
error_weird_message = 5
SIR_ERROR_NOT_MSG_IN_AFTER_RESELECT = 6
error_not_identify_after_reselect = 7
error_too_much_data = 8
error_too_little_data = 9
SIR_MSG_REJECT = 10
SIR_MSG_SDTR = 11
SIR_EV_RESPONSE_OK = 12
error_sigp_set = 13
SIR_EV_PHASE_SWITCH_AFTER_ID = 14
SIR_MSG_WDTR = 15
SIR_MSG_IGNORE_WIDE_RESIDUE = 16
SIR_NOTIFY_DISC = 100
SIR_NOTIFY_RESELECT = 101
SIR_NOTIFY_MSG_IN = 102
SIR_NOTIFY_STATUS = 103
SIR_NOTIFY_DUMP = 104
SIR_NOTIFY_DUMP2 = 105
SIR_NOTIFY_SIGP = 106
SIR_NOTIFY_ISSUE = 107
SIR_NOTIFY_WAIT_RESELECT = 108
SIR_NOTIFY_ISSUE_CHECK = 109
SIR_NOTIFY_DUMP_NEXT_CODE = 110
SIR_NOTIFY_COMMAND = 111
SIR_NOTIFY_DATA_IN = 112
SIR_NOTIFY_DATA_OUT = 113
SIR_NOTIFY_BLOCK_DATA_IN = 114
SIR_NOTIFY_WSR = 115
SIR_NOTIFY_LOAD_SYNC = 116
SIR_NOTIFY_RESELECTED_ON_SELECT = 117
STATE_FREE = 0
STATE_ALLOCATED = 1
STATE_ISSUE = 2
STATE_DISCONNECTED = 3
STATE_DONE = 4
RESULT_OK = 0
MSG_IDENTIFY = 0x80
MSG_DISCONNECT = 0x04
MSG_SAVE_DATA_POINTER = 0x02
MSG_RESTORE_POINTERS = 0x03
MSG_IGNORE_WIDE_RESIDUE = 0x23
X_MSG = 0x01
X_MSG_SDTR = 0x01
X_MSG_WDTR = 0x03
MSG_REJECT = 0x07
BSIZE = 512
//BSIZE=4096
idle:
jump wait_for_reselection
start:
call load_sync
// move 13 to ctest0
// int SIR_NOTIFY_ISSUE
clear target
select atn from scsi_id_buf, reselected_on_select // do I need to clear ATN here?
jump start1, when msg_in
start1:
// move 14 to ctest0
move from msg_out_buf, when msg_out
id_out_mismatch:
jump start1, when msg_out // repeat on parity grounds
jump to_decisions, when not cmd
cmd_phase:
// int SIR_NOTIFY_COMMAND
clear atn
move from cmd_buf, when cmd
cmd_out_mismatch:
jump to_decisions, when not data_in
data_in_phase:
move memory 4, state, scratcha
move memory 4, dmaaddr, scratchb
// int SIR_NOTIFY_DATA_IN
data_in_block_loop:
move scratcha2 to sfbr
jump data_in_normal, if 0
// int SIR_NOTIFY_BLOCK_DATA_IN
move BSIZE, ptr dmaaddr, when data_in // transfer BSIZE bytes
data_in_block_mismatch:
move scratchb1 + BSIZE / 256 to scratchb1 // add BSIZE to scratchb
move scratchb2 + 0 to scratchb2 with carry
move scratchb3 + 0 to scratchb3 with carry
move scratcha2 + 255 to scratcha2 // sub one from block count
move memory 4, scratchb, dmaaddr // save latest dmaddr
jump data_in_block_loop, when data_in
move memory 4, scratcha, state // save latest state
call save_state
jump to_decisions
data_block_mismatch_recover:
move memory 4, scratchb, dmaaddr // save latest dmaddr
data_mismatch_recover:
move memory 4, scratcha, state // save latest state
jump to_decisions // no need to save
// as interrupt routine
// did this
data_in_normal:
move scratcha3 to sfbr
int error_too_much_data, if not 0
move from data_buf, when data_in
data_in_mismatch:
move 2 to scratcha3
move memory 4, scratcha, state
call save_state
jump post_data_to_decisions
data_out_phase:
// int SIR_NOTIFY_DATA_OUT
move memory 4, state, scratcha
move memory 4, dmaaddr, scratchb
data_out_block_loop:
move scratcha2 to sfbr
jump data_out_normal, if 0
move memory 4, dmaaddr, scratchb
move BSIZE, ptr dmaaddr, when data_out // transfer BSIZE bytes
data_out_block_mismatch:
move scratchb1 + BSIZE / 256 to scratchb1 // add BSIZE to scratchb
move scratchb2 + 0 to scratchb2 with carry
move scratchb3 + 0 to scratchb3 with carry
move scratcha2 + 255 to scratcha2 // sub one from block count
move memory 4, scratchb, dmaaddr // save latest dmaddr
jump data_out_block_loop, when data_out
move memory 4, scratcha, state // save latest state
jump to_decisions
data_out_normal:
move scratcha3 to sfbr
int error_too_little_data, if not 0
move from data_buf, when data_out
data_out_mismatch:
move 2 to scratcha3
move memory 4, scratcha, state
call save_state
jump post_data_to_decisions
status_phase:
move from status_buf, when status
// int SIR_NOTIFY_STATUS
int error_unexpected_phase, when not msg_in
msg_in_phase:
move 1, scratcha, when msg_in
// int SIR_NOTIFY_MSG_IN
jump rejected, if MSG_REJECT
msg_in_not_reject:
jump disconnected, if MSG_DISCONNECT
jump msg_in_skip, if MSG_SAVE_DATA_POINTER
jump msg_in_skip, if MSG_RESTORE_POINTERS
jump ignore_wide, if MSG_IGNORE_WIDE_RESIDUE
jump extended, if X_MSG
int error_not_cmd_complete, if not 0
move scntl2&0x7e to scntl2 // take care not to clear WSR
clear ack
wait disconnect
// update state
move memory 4, state, scratcha
move STATE_DONE to scratcha0
move RESULT_OK to scratcha1
move memory 4, scratcha, state
call save_state
// int SIR_MSG_IO_COMPLETE
intfly 0
jump issue_check
rejected:
int SIR_MSG_REJECT
clear ack
jump to_decisions
msg_in_skip:
clear ack
jump to_decisions
extended:
clear ack
int error_unexpected_phase, when not msg_in
move 1, scratcha1, when msg_in
jump ext_3, if 3
jump ext_2, if 2
int error_weird_message, if not 1
ext_1:
clear ack
int error_unexpected_phase, when not msg_in
move 1, scratcha1, when msg_in
jump ext_done
ext_3: clear ack
int error_unexpected_phase, when not msg_in
move 1, scratcha1, when msg_in
clear ack
int error_unexpected_phase, when not msg_in
move 1, scratcha2, when msg_in
clear ack
int error_unexpected_phase, when not msg_in
move 1, scratcha3, when msg_in
move scratcha1 to sfbr
jump ext_done, if not X_MSG_SDTR
// the target sent SDTR - leave ACK asserted and signal kernel
// kernel will either restart at reject, or continue
sdtr: int SIR_MSG_SDTR
clear ack
jump to_decisions
ext_2: clear ack
int error_unexpected_phase, when not msg_in
move 1, scratcha1, when msg_in
clear ack
int error_unexpected_phase, when not msg_in
move 1, scratcha2, when msg_in
move scratcha1 to sfbr
jump ext_done, if not X_MSG_WDTR
wdtr: int SIR_MSG_WDTR
clear ack
jump to_decisions
ext_done:
// ought to check message here, but instead reject all
// NB ATN set
reject:
set atn // get target's ATN
clear ack // finish ACK
move MSG_REJECT to scratcha // prepare message
int error_unexpected_phase, when not msg_out// didn't get ATN
clear atn // last byte coming
move 1, scratcha, when msg_out // send byte
clear ack // finish ACK
jump reject, when msg_out // parity error
jump to_decisions
ignore_wide:
clear ack
int error_unexpected_phase, when not msg_in
move 1, scratcha1, when msg_in
int SIR_MSG_IGNORE_WIDE_RESIDUE
clear ack
jump to_decisions
// sends a response to a message
response:
set atn
clear ack
int error_unexpected_phase, when not msg_out
response_repeat:
move from msg_out_buf, when msg_out
jump response_repeat, when msg_out // repeat on parity grounds
// now look for response
// msg_in could be a REJECT
// anything other message is something else so signal kernel first
jump response_msg_in, when msg_in
int SIR_EV_RESPONSE_OK // not a MSG_IN so OK
jump to_decisions
response_msg_in:
move 1, scratcha, when msg_in
jump rejected, if MSG_REJECT // go and generate rej interrupt
int SIR_EV_RESPONSE_OK // not a REJECT so OK
jump msg_in_not_reject // try others
disconnected:
// move 5 to ctest0
move scntl2&0x7e to scntl2 // don't clear WSR
clear ack
wait disconnect
// UPDATE state to disconnected
move memory 4, state, scratcha
move STATE_DISCONNECTED to scratcha0
move memory 4, scratcha, state
call save_state
wsr_check:
move scntl2&0x01 to sfbr
int SIR_NOTIFY_WSR, if not 0
// int SIR_NOTIFY_DISC
jump issue_check
reselected_on_select:
int SIR_NOTIFY_RESELECTED_ON_SELECT
jump reselected
wait_for_reselection:
// move 11 to ctest0
// int SIR_NOTIFY_WAIT_RESELECT
wait reselect sigp_set
reselected:
// move 12 to ctest0
clear target
int SIR_ERROR_NOT_MSG_IN_AFTER_RESELECT, when not msg_in
move 1, scratchb, when msg_in
int error_not_identify_after_reselect, if not MSG_IDENTIFY and mask 0x1f
// int SIR_NOTIFY_RESELECT
// now locate the right DSA - note do not clear ACK, so target doesn't start
// synchronous transfer until we are ready
find_dsa:
// move 6 to ctest0
move memory 4, dsa_head, dsa
find_dsa_loop:
// move 7 to ctest0
move dsa0 to sfbr
jump find_dsa_1, if not 0
move dsa1 to sfbr
jump find_dsa_1, if not 0
move dsa2 to sfbr
jump find_dsa_1, if not 0
move dsa3 to sfbr
int error_reselected, if 0 // couldn't match dsa (panic)
find_dsa_1:
// move 8 to ctest0
// load state from DSA into dsa_copy
call load_state
move memory 4, state, scratcha // get dsastate in scratcha
move scratcha0 to sfbr // and state variable in sfbr
jump find_dsa_next, if not STATE_DISCONNECTED // wrong state
move ssid & ssid_mask to sfbr // get target ID
move memory 1, targ, find_dsa_smc1 // forge target comparison instruction
find_dsa_smc1:
jump find_dsa_next, if not 255 // jump if not matched
move memory 1, lun, find_dsa_smc2 // forge lun comparison instruction
move scratchb0 to sfbr // recover IDENTIFY message
find_dsa_smc2:
jump reload_sync, if 255 and mask ~7 // off we jolly well go
find_dsa_next:
move memory 4, next, dsa // find next
jump find_dsa_loop
// id_out terminated early
// most likely the message wasn't recognised
// clear ATN and accept the message in
id_out_mismatch_recover:
clear atn
jump msg_in_phase, when msg_in
int SIR_MSG_REJECT
jump to_decisions
// Reload synchronous registers after a reconnect. If the transfer is a synchronous read, then
// as soon as we clear ACK, the target will switch to data_in and start blasting data into the
// fifo. We need to be executing the 'jump when data_in' instruction before the target stops REQing
// since it is the REQ which latches the 'when'. The target will do 16 REQs before stopping, so
// we have 16 bytes (160uS) plus delays to do this after clearing ACK. Once the jump is executing,
// the target will wait, so as much debugging as you like can happen in data_in_phase, just don't
// stick any delays between 'clear ack' and 'jump data_in_phase, when data_in'.
reload_sync:
call load_sync
clear ack
to_decisions:
jump data_in_phase, when data_in
jump cmd_phase, if cmd
jump data_out_phase, if data_out
jump status_phase, if status
jump msg_in_phase, if msg_in
int error_unexpected_phase
post_data_to_decisions:
jump status_phase, when status
jump msg_in_phase, if msg_in
int error_unexpected_phase
//
// MULTI_TARGET
//
// following must mirror top of dsa structure
// the first section is loaded and saved, the
// second section loaded only
dsa_copy:
state: defw 0 // a0 is state, a1 result, a2 dma block count
dmaaddr: defw 0 // dma address for block moves
dsa_save_end:
targ: defw 0 // lsb is target
lun: defw 0 // lsb is lun
sync: defw 0 // lsb is scntl3, sxfer
next: defw 0
dsa_load_end:
dsa_load_len = dsa_load_end - dsa_copy
dsa_save_len = dsa_save_end - dsa_copy
load_state:
// load state from DSA into dsa_copy
// move 9 to ctest0
move memory 4, dsa, load_state_smc0 + 4
load_state_smc0:
move memory dsa_load_len, 0, dsa_copy
// move 20 to ctest0
return
save_state:
move memory 4, dsa, save_state_smc0 + 8
save_state_smc0:
move memory dsa_save_len, dsa_copy, 0
return
sigp_set:
// int SIR_NOTIFY_SIGP
move ctest2 to sfbr // clear SIGP
issue_check:
// int SIR_NOTIFY_ISSUE_CHECK
// move 1 to ctest0
move memory 4, dsa_head, dsa
issue_check_loop:
// move 2 to ctest0
move dsa0 to sfbr
jump issue_check_1, if not 0
move dsa1 to sfbr
jump issue_check_1, if not 0
move dsa2 to sfbr
jump issue_check_1, if not 0
move dsa3 to sfbr
jump wait_for_reselection, if 0 // nothing to do
issue_check_1:
// move 3 to ctest0
call load_state
move memory 4, state, scratcha // get dsastate in scratcha
move scratcha0 to sfbr // and state variable in sfbr
jump start, if STATE_ISSUE // right state
issue_check_next:
// move 4 to ctest0
move memory 4, next, dsa // find next
jump issue_check_loop
load_sync:
move memory 4, sync, scratcha // load the sync stuff
move scratcha0 to sfbr // assuming load_state has been called
move sfbr to scntl3
move scratcha1 to sfbr
move sfbr to sxfer
// int SIR_NOTIFY_LOAD_SYNC
return