last changes before merger with reno version. cross fingers.

[unix-history] / usr / src / sys / i386 / i386 / mem.c

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* %sccs.include.noredist.c%
*
*      @(#)mem.c       5.5 (Berkeley) %G%
*/

/*
* Memory special file
*/

#include "machine/pte.h"

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

mmread(dev, uio)
       dev_t dev;
       struct uio *uio;
{

       return (mmrw(dev, uio, UIO_READ));
}

mmwrite(dev, uio)
       dev_t dev;
       struct uio *uio;
{

       return (mmrw(dev, uio, UIO_WRITE));
}

mmrw(dev, uio, rw)
       dev_t dev;
       struct uio *uio;
       enum uio_rw rw;
{
       register int o;
       register u_int c, v;
       register struct iovec *iov;
       int error = 0;


       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 = ctob(v) | PG_V |
                               (rw == UIO_READ ? PG_KR : PG_KW);
                       load_cr3(u.u_pcb.pcb_ptd);
                       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, rw, uio);
                       continue;

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

/* minor device 2 is EOF/RATHOLE */
               case 2:
                       if (rw == UIO_READ)
                               return (0);
                       c = iov->iov_len;
                       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);
}