BSD 4_3_Reno release

[unix-history] / usr / src / sys / vax / mem.c

/*
* Copyright (c) 1982, 1986, 1990 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
*      @(#)mem.c       7.4 (Berkeley) 4/3/90
*/

/*
* Memory special file
*/

#include "pte.h"

#include "param.h"
#include "user.h"
#include "conf.h"
#include "buf.h"
#include "systm.h"
#include "vm.h"
#include "cmap.h"

#include "mtpr.h"

mmrw(dev, uio, flags)
       dev_t dev;
       struct uio *uio;
       int flags;
{
       register int o;
       register u_int c, v;
       register struct iovec *iov;
       int error = 0;
       extern int umbabeg, umbaend;


       while (uio->uio_resid > 0 && error == 0) {
               iov = uio->uio_iov;
               if (iov->iov_len == 0) {
                       uio->uio_iov++;
                       uio->uio_iovcnt--;
                       if (uio->uio_iovcnt < 0)
                               panic("mmrw");
                       continue;
               }
               switch (minor(dev)) {

/* minor device 0 is physical memory */
               case 0:
                       v = btop(uio->uio_offset);
                       if (v >= physmem)
                               goto fault;
                       *(int *)mmap = v | PG_V |
                               (uio->uio_rw == UIO_READ ? PG_KR : PG_KW);
                       mtpr(TBIS, vmmap);
                       o = (int)uio->uio_offset & PGOFSET;
                       c = (u_int)(NBPG - ((int)iov->iov_base & PGOFSET));
                       c = MIN(c, (u_int)(NBPG - o));
                       c = MIN(c, (u_int)iov->iov_len);
                       error = uiomove((caddr_t)&vmmap[o], (int)c, uio);
                       continue;

/* minor device 1 is kernel memory */
               case 1:
                       if ((caddr_t)uio->uio_offset < (caddr_t)&umbabeg &&
                           (caddr_t)uio->uio_offset + uio->uio_resid >= (caddr_t)&umbabeg)
                               goto fault;
                       if ((caddr_t)uio->uio_offset >= (caddr_t)&umbabeg &&
                           (caddr_t)uio->uio_offset < (caddr_t)&umbaend)
                               goto fault;
                       c = iov->iov_len;
                       if (!kernacc((caddr_t)uio->uio_offset, c,
                           uio->uio_rw == UIO_READ ? B_READ : B_WRITE))
                               goto fault;
                       error = uiomove((caddr_t)uio->uio_offset, (int)c, uio);
                       continue;

/* minor device 2 is EOF/RATHOLE */
               case 2:
                       if (uio->uio_rw == UIO_WRITE)
                               uio->uio_resid = 0;
                       return (0);

/* minor device 3 is unibus memory (addressed by shorts) */
               case 3:
                       c = iov->iov_len;
                       if (!kernacc((caddr_t)uio->uio_offset, c,
                           uio->uio_rw == UIO_READ ? B_READ : B_WRITE))
                               goto fault;
                       if (!useracc(iov->iov_base, c,
                           uio->uio_rw == UIO_READ ? B_WRITE : B_READ))
                               goto fault;
                       error = UNIcpy((caddr_t)uio->uio_offset, iov->iov_base,
                           (int)c, uio->uio_rw);
                       break;
               }
               if (error)
                       break;
               iov->iov_base += c;
               iov->iov_len -= c;
               uio->uio_offset += c;
               uio->uio_resid -= c;
       }
       return (error);
fault:
       return (EFAULT);
}

/*
* UNIBUS Address Space <--> User Space transfer
*/
UNIcpy(uniadd, usradd, n, rw)
       caddr_t uniadd, usradd;
       register int n;
       enum uio_rw rw;
{
       register short *from, *to;

       if (rw == UIO_READ) {
               from = (short *)uniadd;
               to = (short *)usradd;
       } else {
               from = (short *)usradd;
               to = (short *)uniadd;
       }
       for (n >>= 1; n > 0; n--)
               *to++ = *from++;
       return (0);
}