BSD 4_1_snap development

[unix-history] / sys / dev / mem.c

/*      mem.c   4.3     81/03/08        */

/*
* Memory special file
*      minor device 0 is physical memory
*      minor device 1 is kernel memory 
*      minor device 2 is EOF/RATHOLE
*      minor device 3 is unibus memory (addressed by shorts)
*/

#include "../h/param.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/conf.h"
#include "../h/buf.h"
#include "../h/systm.h"
#include "../h/pte.h"
#include "../h/mtpr.h"
#include "../h/vm.h"
#include "../h/cmap.h"

mmread(dev)
{
       register int o;
       register unsigned c, v;

       switch (minor(dev)) {

       case 0:
               while (u.u_count != 0 && u.u_error == 0) {
                       if (fubyte(u.u_base) == -1)
                               goto fault;
                       v = btop(u.u_offset);
                       if (v >= physmem)
                               goto fault;
                       *(int *)mmap = v | (PG_V | PG_KR);
                       mtpr(TBIS, vmmap);
                       o = (int)u.u_offset & PGOFSET;
                       c = min((unsigned)(NBPG - o), u.u_count);
                       c = min(c, (unsigned)(NBPG - ((int)u.u_base&PGOFSET)));
                       if (copyout((caddr_t)&vmmap[o], u.u_base, c))
                               goto fault;
                       u.u_count -= c;
                       u.u_base += c;
                       u.u_offset += c;
               }
               return;

       case 1:
               if ((caddr_t)u.u_offset < (caddr_t)&umbabeg &&
                   (caddr_t)u.u_offset + u.u_count >= (caddr_t)&umbabeg)
                       goto fault;
               if ((caddr_t)u.u_offset >= (caddr_t)&umbabeg &&
                   (caddr_t)u.u_offset < (caddr_t)&umbaend)
                       goto fault;
               if (!kernacc((caddr_t)u.u_offset, u.u_count, B_READ))
                       goto fault;
               if (copyout((caddr_t)u.u_offset, u.u_base, u.u_count))
                       goto fault;
               c = u.u_count;
               u.u_count = 0;
               u.u_base += c;
               u.u_offset += c;
               return;

       case 2:
               return;

       case 3:
               if (!kernacc((caddr_t)u.u_offset, u.u_count, B_READ))
                       goto fault;
               if (!useracc(u.u_base, u.u_count, B_WRITE))
                       goto fault;
               UNIcpy((caddr_t)u.u_offset, u.u_base, u.u_count, B_READ);
               c = u.u_count;
               u.u_count = 0;
               u.u_base += c;
               u.u_offset += c;
               return;
       }
fault:
       u.u_error = EFAULT;
       return;
}

mmwrite(dev)
{
       register int o;
       register unsigned c, v;

       switch (minor(dev)) {

       case 0:
               while (u.u_count != 0 && u.u_error == 0) {
                       if (fubyte(u.u_base) == -1)
                               goto fault;
                       v = btop(u.u_offset);
                       if (v >= physmem)
                               goto fault;
                       *(int *)mmap = v | (PG_V | PG_KW);
                       mtpr(TBIS, vmmap);
                       o = (int)u.u_offset & PGOFSET;
                       c = min((unsigned)(NBPG - o), u.u_count);
                       c = min(c, (unsigned)(NBPG - ((int)u.u_base&PGOFSET)));
                       if (copyin(u.u_base, (caddr_t)&vmmap[o], c))
                               goto fault;
                       u.u_count -= c;
                       u.u_base += c;
                       u.u_offset += c;
               }
               return;

       case 1:
               if (!kernacc((caddr_t)u.u_offset, u.u_count, B_WRITE))
                       goto fault;
               if (copyin(u.u_base, (caddr_t)u.u_offset, u.u_count))
                       goto fault;
               u.u_base += u.u_count;
               u.u_offset += u.u_count;
               u.u_count = 0;
               return;

       case 2:
               u.u_offset += u.u_count;
               u.u_count = 0;
               return;

       case 3:
               if (!kernacc((caddr_t)u.u_offset, u.u_count, B_WRITE))
                       goto fault;
               if (!useracc(u.u_base, u.u_count, B_READ))
                       goto fault;
               UNIcpy((caddr_t)u.u_offset, u.u_base, u.u_count, B_WRITE);
               u.u_base += u.u_count;
               u.u_offset += u.u_count;
               u.u_count = 0;
               return;
       }
fault:
       u.u_error = EFAULT;
       return;
}

/*
* UNIBUS Address Space <--> User Space transfer
*/
UNIcpy(uniadd, usradd, bknt, direct)
       caddr_t uniadd, usradd;
       unsigned bknt;
{
       register short *from, *to;
       register int i;

       if (direct == B_READ) {
               from = (short *) uniadd;
               to = (short *) usradd;
       } else {
               from = (short *) usradd;
               to = (short *) uniadd;
       }
       for (i = (bknt>>1); i > 0; i--)
               *to++ = *from++;
}