# #include "param.h" #include "user.h" #include "buf.h" #include "net_net.h" #include "net_netbuf.h" #include "imp11a.h" #include "imp.h" #include "file.h" #include "net_ncp.h" #include "net_contab.h" /*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 stop 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= impiend= impostart= impoend= imp.nrcv= calls: impstrat impldrd called by: impopen history: initial coding 10/5/75 S. F. Holmgren */ imp_init() { int i; extern lbolt; imp_reset(); HMR_interval = 60; set_HMR(); /* start strobing host master ready */ while( IMPADDR->istat&imasrdy) sleep (&lbolt, 0); /* until imp says is up */ /* Turn off further strobing, to avoid data lossage caused * by BIS'ing the input CSR during data transfers. --KLH */ HMR_interval = 0; /* KLH 4/79 */ /* enable interrupts */ IMPADDR->istat =| iienab; /* KLH 4/79 -- OR the enable bits, */ IMPADDR->ostat =| iienab; /* to avoid needless HMR yo-yoing. */ } /*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 */ imp_output() { register struct buf *bp; register char *endaddr; register char *addr; 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; if (bp->b_blkno) IMPADDR->ostat =& ~oendmsg; else IMPADDR->ostat =| oendmsg; IMPADDR->spo = bp->b_addr; /* load start addr */ IMPADDR->owcnt = - (bp->b_wcount >> 1); IMPADDR->ostat =| igo; } /*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 */ impread( addr,size ) /* start a read from imp into data area */ { spl_imp (); /* not to be interrupted, please */ impi_adr = addr; impi_wcnt = size>>1; IMPADDR->spi = addr; IMPADDR->iwcnt = -impi_wcnt; IMPADDR->istat =| (igo | iwrtenble); } /*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 */ i11a_oint() { char errbits; if (impotab.d_active == 0) { /* ignore unexpected interrupts */ printf ("\nIMP: Phantom Out Int\n"); return; } errbits = 0; if( IMPADDR->ostat & itimout ) /* timeout errror */ { errbits++; printf ("\nIMP: Output Timeout\n"); } imp_odone (errbits); } /* name: imp_iint function: Simply wakes up the input handling process to tell something has arrived from the network algorithm: calls wakeup parameters: none returns: i hope so globals: imp_proc calls: wakeup to start input handling process running called by: hardware history: coded by Steve Holmgren 04/28/75 */ i11a_iint() { imp_stat.error = (IMPADDR->istat < 0) & (IMPADDR->iwcnt != 0); imp_stat.inpendmsg = IMPADDR->istat & iendmsg; imp_stat.inpwcnt = IMPADDR->iwcnt; wakeup( &imp ); } /*name: /*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 */ /* The following procedure is needed for compatibility with * a munged kernel clock routine that calls this routine every tic. * Why THAT is needed has to do with the fact that some other imp * interfaces (eg ILL) need true strobing to maintain host-master-ready and * if that is held up by an interrupt-level debugging printf, you lose. * Whereas for the IMP11A unrestrained strobing will screw data xfer... sigh. * --KLH */ clk_HMR() /* Crock for clock level hacking --KLH 4/79 */ { } set_HMR() { if( HMR_interval ) { IMPADDR->istat =| hmasrdy; timeout( &set_HMR,0,HMR_interval); /* restart */ }else{ wakeup (&HMR_interval); } } /* 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: Added 1 Feb 77 for compatibility with other imp-drivers, by JC McMillan */ spl_imp() { spl5(); } /*name: imp_reset function: reset interface algorithm: reset host_master ready. Reset all other bits parameters: none returns: nothing globals: none calls: nobody called by: imp_dwn imp_init history: initial coding 08 Jan 77 by JSK */ imp_reset() { register char *impadd; printf("\nIMP:Reset\n"); /* Whoever coded this section and imp_init obviously never tried it, * because it unconditionally hangs the NCP - set_HMR isn't called * until AFTER imp_reset, so the sleep never wakes up!! * Hence, commented out. --KLH 4/79 spl6 (); HMR_interval = 0; sleep (&HMR_interval); */ impadd = IMPADDR; impadd -> istat =| irst; impadd -> istat =& ~irst; impadd -> ostat =| irst; impadd -> ostat =& ~irst; impadd -> istat = impadd->ostat = 0; }