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/* $OpenBSD: mem.c,v 1.7 2003/06/02 23:27:53 millert Exp $ */
/* $NetBSD: mem.c,v 1.1 1996/09/30 16:34:50 ws Exp $ */
/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1982, 1986, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)mem.c 8.3 (Berkeley) 1/12/94
*/
/*
* Memory special file
*/
#include <sys/param.h>
#include <sys/buf.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <machine/conf.h>
#include <uvm/uvm_extern.h>
/*ARGSUSED*/
int
mmopen(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
switch (minor(dev)) {
case 0:
case 1:
case 2:
case 12:
return (0);
default:
return (ENXIO);
}
}
/*ARGSUSED*/
int
mmclose(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
return 0;
}
/*ARGSUSED*/
int
mmrw(dev, uio, flags)
dev_t dev;
struct uio *uio;
int flags;
{
vm_offset_t v;
u_int c;
struct iovec *iov;
int error = 0;
static caddr_t zeropage;
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 = uio->uio_offset;
c = uio->uio_resid;
/* This doesn't allow device mapping! XXX */
pmap_real_memory(&v, (vm_size_t *)&c);
error = uiomove((caddr_t)v, c, uio);
continue;
/* minor device 1 is kernel memory */
case 1:
v = uio->uio_offset;
c = min(iov->iov_len, MAXPHYS);
error = uiomove((caddr_t)v, 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 12 (/dev/zero) is source of nulls on read, rathole on write */
case 12:
if (uio->uio_rw == UIO_WRITE) {
c = iov->iov_len;
break;
}
if (zeropage == NULL) {
zeropage = (caddr_t)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
bzero(zeropage, PAGE_SIZE);
}
c = min(iov->iov_len, PAGE_SIZE);
error = uiomove(zeropage, c, uio);
continue;
default:
return ENXIO;
}
if (error)
break;
iov->iov_base += c;
iov->iov_len -= c;
uio->uio_offset += c;
uio->uio_resid -= c;
}
return error;
}
paddr_t
mmmmap(dev, off, prot)
dev_t dev;
off_t off;
int prot;
{
return (-1);
}
/*ARGSUSED*/
int
mmioctl(dev, cmd, data, flags, p)
dev_t dev;
u_long cmd;
caddr_t data;
int flags;
struct proc *p;
{
return (EOPNOTSUPP);
}
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