SRI-NOSC/ncpk/dti/impo.c
#
#include "../h/param.h"
#include "../h/user.h"
#include "../h/buf.h"
#include "../h/reg.h"
#include "../h/net.h"
#include "../h/netbuf.h"
#include "../h/imp.h"
#include "../h/file.h"
#include "../h/ncp.h"
#include "../h/contab.h"
/* array that holds the rfnm wait bits */
char host_map[32];
/* name:
impopen
function:
to initialize the imp and to serve as a basis for
the main input driving loop for data from the network
algorithm:
initialize the imp (imp_init)
start up a kernel process to handle data from the net
parameters:
none
returns:
nothing
globals:
ncpopnstate
calls:
imp_init
sleep(sys)
newproc(sys)
impldrd
imp_input
called by:
ncpopen
history:
initial coding 1/7/75 by S. F. Holmgren
modified 10/5/75 chopped initialize into imp_init
and started checking imp_error bit and inited if
bit was on S. F. Holmgren
modified 28 Oct 76 for IMP-11A by P. B. Jones
*/
impopen()
{
register int *fp;
register int *p;
/* start up kernel input process to handle input */
if( newproc() )
{
/* release any hold we may have on parents files */
exit0 ();
imp_proc = u.u_procp;
HMR_interval = 10;
set_HMR();
/* loop around handling input from imp */
spl_imp(); /* so imp wont interrupt */
/* initialize the imp */
imp_init();
for( ;; )
{
spl_imp();
sleep( &imp,-25 ); /* wait for something */
/*
if( ncpopnstate == 0 ) break; /* we down? */
imp_input(); /* handle it */
}
imp_dwn(); /* clean up kernel data */
u.u_error = EBADF; /* so return to user will get -1 */
}
}
/* name:
imp_init
function:
to initialize the imp interface hardware, and various software
parameters.
algorithm:
set fixed input addresses
set fixed output addresses
reset the imp interface
start strobing the host master ready bit
enable interrupts
clear any extended memory address bits
build and send 3 nops to the imp
built fixed parameters in the imp input leader
parameters:
none
returns:
an initialized imp
globals:
impncp=
impistart=
impostart=
imp.nrcv=
calls:
impstrat
impldrd
called by:
impopen
history:
initial coding 10/5/75 S. F. Holmgren
modified 28 Oct 76 for IMP-11A by P. B. Jones
*/
imp_init()
{
int i;
register int saver0;
/* set fixed input addresses */
impncp = &imp.nrcv; /* addr of data to hand to_ncp for daemon comm. */
impistart = &imp.type; /* start addr to give imp interface for leader reads */
/* set fixed output addresses */
impostart = &oimp; /* start addr of output leader */
/* reset the imp interface */
do
{
imp_reset(); /* PBJ */
saver0 = u.u_ar0[R0];
u.u_ar0[R0] = 2; /* time to sleep */
sslep (); /* sleep for 2 secs */
u.u_ar0[R0] = saver0; /* restore */
}
while( IMPADDR->istat&imasrdy ); /* until imp says is up PBJ */
/* enable interrupts and unlock input control reg PBJ */
IMPADDR->istat = IMPADDR->ostat = iienab;
/* build and send 3 host imp nops */
oimp.o_type = ih_nop; /* set opcode to h_i_nop */
impobuf.b_addr = impostart; /* set addr for output */
impobuf.b_wcount = 4; /* send the four imp leader bytes */
/* send the three nops */
for ( i = 0; i < 3; i++ )
{
/* strobe host master ready */
IMPADDR->istat =| hmasrdy; /* PBJ */
impstrat( &impobuf ); /* send one */
iowait( &impobuf ); /* wait for one to fin */
}
/* set parameters on input leader */
imp.nrcv = ncp_rcv; /* perm receive comm here */
impldrd(); /* set up input side of imp interface */
}
/* name:
imp_dwn
function:
clean up ncp data structures so that an ncpdaemon restart will
work correctly.
algorithm:
reset the imp interface
quit setting host master ready
free any input message
clean up input variables
clear out all messages queued for the output side
reset any rfnm bits
let the kernel buffer code clean up its own
parameters:
none
returns:
nothing
globals:
HMR_interval =
impmsg =
implen =
impiptr =
impflushing =
impistart =
impotab (forward and backward links)
host_map[-] =
calls:
freemsg
ncp_bfrdwn
called by:
imp_open
history:
initial coding 6/22/76 by S. F. Holmgren
modified 28 Oct 76 for IMP-11A by P. B. Jones
*/
imp_dwn()
{
register char *p;
/* reset the imp interface */
imp_reset(); /* PBJ */
/* quit setting host master ready */
HMR_interval = 0;
/* cleanup the input side */
freemsg( impmsg );
impmsg = implen = impiptr = impflushing = impistart = 0;
/* clean up the output side */
impotab.d_active = 0;
/* get rid of messages waiting to be output */
p = impotab.d_actf;
while ( p )
{
if( p->b_flags & B_SPEC ) /* this a net message */
freemsg( p->b_dev ); /* free it */
else
iodone( p ); /* sys buffer say done */
}
impotab.d_actf = impotab.d_actl = 0;
/* clear out any waiting rfnm bits */
for( p = &host_map[0]; p < &host_map[32]; p++ )
*p = 0;
/* let the net message software clean up */
ncp_bfrdwn();
}
/* name:
impstrat
function:
Used to link output buffers into the imp output queue
for transmission to the network.
algorithm:
if queue empty put buffer at front.
else
link buffer to end
if imp output is not active start it up
parameters:
abp - pointer to the buffer to be sent
returns:
nothing
globals:
impotab.d_actf=
impotab.d_actl=
bp->b_forw=
calls:
imp_output
called by:
sndnetbytes
impopen
history:
initial coding 1/7/75 by S. F. Holmgren
modified 28 Oct 76 for IMP-11A by P. B. Jones
*/
impstrat( abp )
struct buf *abp;
{
register struct buf *bp;
bp = abp;
bp->b_forw = 0; /* null forward pointer this buffer */
spl_imp();
if( impotab.d_actf == 0 ) /* anything in list ?? */
impotab.d_actf = bp; /* no make this the first */
else
impotab.d_actl->b_forw = bp; /* make this new last */
/* set last to this */
impotab.d_actl = bp;
if (impotab.d_active == 0) /* do we need to start the imp? */
imp_output(); /* yep kick it over */
}
/* name:
imp_output
function:
Takes buffers( see buf.h ) linked into the impotab active
queue and applies them to the imp interface.
algorithm:
check to see if the queue is empty if so return
set the active bit
enable output interrupts and the endmsg bit( imp interface manual)
calculate then end address and perform the mod 2 function
on the calculated address( again see imp interface manual)
load the start output address register
load the end output address register which is also an implied
go
parameters:
none
returns:
nothing
globals:
impotab.d_actf
(buffer)
calls:
nothing
called by:
impstrat
imp_oint
history:
initial coding 1/7/75 by S. F. Holmgren
modified 28 Oct 76 for IMP-11A by P. B. Jones
*/
imp_output()
{
register struct buf *bp;
if((bp = impotab.d_actf) == 0)
return; /* return nothing to do */
impotab.d_active++; /* something to do set myself active */
/* set or reset disable endmsg according to user wishes */
IMPADDR -> ostat = iienab; /* PBJ */
if( bp->b_blkno ) /* PBJ */
IMPADDR->ostat =& ~oendmsg;
else
IMPADDR->ostat =| oendmsg;
IMPADDR->spo = bp->b_addr; /* load start addr */
IMPADDR->owcnt = -(bp->b_wcount >> 1); /* load endaddr and go PBJ */
IMPADDR->ostat =| igo; /* crank it up PBJ */
}
/* name:
impldrd
function:
Called when input portion specifically wants to transfer
the first bytes of an imp-to-host and host-to-host leader
into fixed low core.
algorithm:
make sure starting a new input message to be buffered
say doing leader read
load imp input start register from fixed address created
by impopen
load imp input end register from fixed address created
by impopen
parameters:
none
returns:
nothing
globals:
impmsg=
impleader=
impistart
calls:
nothing
called by:
impopen
hh
ih
history:
initial coding 1/7/75 by S. F. Holmgren
modified 28 Oct 76 for IMP-11A by P. B. Jones
*/
impldrd() /* start another leader into imp */
{
spl_imp(); /* make sure im not interrupted */
impmsg = 0; /* start a new message */
impleader++; /* say doing leader read */
IMPADDR->spi = impistart; /* read into "imp" structure */
IMPADDR->iwcnt = -IMPLDLEN;
IMPADDR->istat =| (igo | iwrtenble); /* make it go fast! PBJ */
}
/* name:
impread
function:
to apply an input area to the input side of the imp interface
algorithm:
say not doing leader read
load start input register with address passed
load end input register with address+size passed
parameters:
addr - start address in which to store imp input data
size - available number of bytes in which to store said data
returns:
nothing
globals:
impleader=
calls:
nothing
called by:
flushimp
ihbget
history:
initial coding 1/7/75 by S. F. Holmgren
modified 28 Oct 76 for IMP-11A by P. B. Jones
*/
impread( addr,size ) /* start a read from imp into data area */
{
spl_imp(); /* make sure im not interrupted */
impleader = 0; /* say not doing leader read */
IMPADDR->spi = addr;
IMPADDR->iwcnt = -(size >> 1); /* PBJ */
IMPADDR->istat =| (igo | iwrtenble); /* start it up PBJ */
}
/* name:
imp_oint
function:
This is the imp output interrupt.
Handles both system type buffers( buf.h ) and the network msgs
If it finds that a net message is being sent, steps to the
next buffer in the message and transmits that.
If all buffers of a net message or a standard system buffer
has been encountered, it is freed and the output side is
started once again.
algorithm:
Check for unexpected interrupts from the imp
Get the first buffer from the output queue
If there was an error in output, it is indicated, and the
buffer returned.
If the buffer embodies a network message( B_SPEC ) and
the last buffer of that message has not been sent,
Get to next buffer in net message
Update w_count for that buffer
Update next buffer pointer(av_forw) so next
time come through things will be easier.
Decide whether to set endmsg bit on not.
Start up output side
otherwise
get next buffer in output queue
if this was a net message give it back to the system
otherwise say that the system buffer( buf.h ) is done
if there is nothing to do clean up a little
otherwise
start up the output side again.
parameters:
none
returns:
nothing
globals:
impotab.d_active
buffer->b_flags=
buffer->b_error=
buffer->b_addr=
buffer->b_wcount=
buffer->av_forw=
buffer->b_blkno=
impotab->d_actf=
calls:
imp_output
freemsg
iodone
called by:
system
history:
initial coding 1/7/75 by S. F. Holmgren
*/
imp_oint()
{
register char *buffer;
register struct devtab *iot;
register char *msg;
iot = &impotab;
if( iot->d_active == 0 ) /* ignore unexpected errors */
return;
buffer = iot->d_actf; /* pt at first buffer in list */
if( IMPADDR->ostat & itimout ) /* timeout errror */
{
buffer->b_flags =| B_ERROR;
buffer->b_error = itimout;
}
else /* if kernel msg and has multi buffers send next buffer */
if(( buffer->b_flags & B_SPEC )
&&
/* this last bfr in msg */
(buffer->b_blkno & 01))
{
/* no we disabled endmsg last time must send some more */
msg = buffer->av_forw;
/* set next buffer address into header */
buffer->b_addr = msg->b_data;
/* set length of that buffer into length field */
buffer->b_wcount = ( msg->b_len & 0377 );
/* if this is not the last buffer then disable endmsg */
buffer->b_blkno = (msg == buffer->b_dev) ? 0 : 1;
/* update next msg buffer field */
buffer->av_forw = msg = msg->b_qlink;
/* send to imp */
imp_output();
return;
}
iot->d_actf = buffer->b_forw; /* set top to next */
/* give msg back -- ptr put in by sndnetbytes */
if( buffer->b_flags&B_SPEC )
freemsg( buffer->b_dev );
else
iodone( buffer ); /* say done with buffer */
if( iot->d_actf == 0 ) /* done for awhile?? */
{
iot->d_actl = 0; /* remove queue links */
iot->d_active = 0; /* say we are done */
}
else
imp_output(); /* do some more */
}
/* name:
set_HMR
function:
To repeatedly tickle the host master ready bit of the imp interface
algorithm:
if someone hasnt set HMR_interval to zero ( should i go away?? )
set the host master ready bit
setup timeout so that i am called again
parameters:
none
returns:
nothing
globals:
HMR_interval
hostmaster ready bit=
calls:
timeout(sys)
called by:
impopen
timeout(sys)
history:
initial coding 1/7/75 by S. F. Holmgren
modified 28 Oct 76 for IMP-11A by P. B. Jones
*/
set_HMR()
{
if( HMR_interval )
{
IMPADDR->istat =| hmasrdy;
/* DISABLE
timeout( &set_HMR,0,HMR_interval); /* restart */
}
}
/* name:
spl_imp
function:
centralize priority setting of imp because of variations
in interface configurations
algorithm:
if you can't figure this out you'd better go back and
start all over again
parameters:
absolutely none
returns:
yes - if it doesn't you'll know it!
globals:
no
calls:
spl5
called by:
anyone who doesn't want the imp bothering him
history:
initial coding 28 Oct 76 by P. B. Jones
*/
spl_imp()
{
spl5();
}
/* name:
imp_reset
function:
tweak the correct bits in the imp interface to reset it..
this routine for the IMP-11A is needed to make the reset easy
the old interface needed to set one bit.. this one sets and
resets two
algorithm:
set the reset bits on the input and output sides of IMP11-A
reset them according to the manual
parameters:
none
returns:
nothing
globals:
none
calls:
nobody
called by:
imp_dwn
imp_init
history:
initial coding 28 Oct 76 by P. B. Jones
*/
imp_reset()
{
register char *impadd;
impadd = IMPADDR;
impadd->istat =| irst; /* reset imp11a */
impadd->istat =& ~irst;
impadd->ostat =| (irst | irdyclr); /* clear ready err and iface */
impadd->ostat =& ~irst; /* cleared for imp 11 a */
impadd->istat = impadd->ostat = 0;
}