311 lines
7.4 KiB
C
311 lines
7.4 KiB
C
/* $NetBSD: mem.c,v 1.6 1997/03/24 23:49:41 gwr Exp $ */
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/*
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* Copyright (c) 1988 University of Utah.
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* Copyright (c) 1982, 1986, 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* the Systems Programming Group of the University of Utah Computer
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* Science Department.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)mem.c 8.3 (Berkeley) 1/12/94
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*/
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/*
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* Memory special file
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/buf.h>
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#include <sys/conf.h>
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#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <sys/uio.h>
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#include <vm/vm.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_map.h>
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#include <machine/cpu.h>
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#include <machine/pte.h>
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#include <machine/pmap.h>
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#include <machine/machdep.h>
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#include <machine/mon.h>
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/* XXX - Put this in pmap_pvt.h or something? */
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extern vm_offset_t avail_start;
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#define mmread mmrw
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cdev_decl(mm);
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static int promacc __P((caddr_t, int, int));
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static caddr_t devzeropage;
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/*ARGSUSED*/
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int
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mmopen(dev, flag, mode, p)
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dev_t dev;
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int flag, mode;
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struct proc *p;
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{
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return (0);
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}
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/*ARGSUSED*/
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int
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mmclose(dev, flag, mode, p)
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dev_t dev;
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int flag, mode;
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struct proc *p;
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{
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return (0);
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}
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/*ARGSUSED*/
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int
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mmrw(dev, uio, flags)
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dev_t dev;
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struct uio *uio;
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int flags;
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{
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register struct iovec *iov;
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register vm_offset_t o, v;
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register int c, rw;
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int error = 0;
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static int physlock;
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if (minor(dev) == 0) {
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if (vmmap == 0)
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return (EIO);
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/* lock against other uses of shared vmmap */
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while (physlock > 0) {
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physlock++;
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error = tsleep((caddr_t)&physlock, PZERO | PCATCH,
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"mmrw", 0);
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if (error)
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return (error);
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}
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physlock = 1;
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}
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while (uio->uio_resid > 0 && error == 0) {
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iov = uio->uio_iov;
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if (iov->iov_len == 0) {
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uio->uio_iov++;
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uio->uio_iovcnt--;
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if (uio->uio_iovcnt < 0)
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panic("mmrw");
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continue;
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}
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switch (minor(dev)) {
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case 0: /* /dev/mem */
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v = uio->uio_offset;
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/* allow reads only in RAM */
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if (!pmap_pa_exists(v)) {
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error = EFAULT;
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goto unlock;
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}
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/*
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* If the offset (physical address) is within the
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* linearly mapped range (0 .. avail_start) then
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* we can save some hair by using the /dev/kmem
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* alias mapping known to exist for this range.
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*/
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if (v < avail_start) {
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v += KERNBASE;
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goto use_kmem;
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}
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/* Temporarily map the memory at vmmap. */
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pmap_enter(pmap_kernel(), vmmap,
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trunc_page(v), uio->uio_rw == UIO_READ ?
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VM_PROT_READ : VM_PROT_WRITE, TRUE);
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o = v & PGOFSET;
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c = min(uio->uio_resid, (int)(NBPG - o));
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error = uiomove((caddr_t)vmmap + o, c, uio);
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pmap_remove(pmap_kernel(), vmmap, vmmap + NBPG);
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break;
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case 1: /* /dev/kmem */
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v = uio->uio_offset;
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use_kmem:
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/*
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* One page at a time to simplify access checks.
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* Note that we can get here from case 0 above!
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*/
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o = v & PGOFSET;
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c = min(uio->uio_resid, (int)(NBPG - o));
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rw = (uio->uio_rw == UIO_READ) ? B_READ : B_WRITE;
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if (!(kernacc((caddr_t)v, c, rw) ||
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promacc((caddr_t)v, c, rw)))
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{
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error = EFAULT;
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/* Note: case 0 can get here, so must unlock! */
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goto unlock;
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}
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error = uiomove((caddr_t)v, c, uio);
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break;
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case 2: /* /dev/null */
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if (uio->uio_rw == UIO_WRITE)
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uio->uio_resid = 0;
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return (0);
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case 11: /* /dev/eeprom */
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error = eeprom_uio(uio);
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/* Yes, return (not break) so EOF works. */
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return (error);
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case 12: /* /dev/zero */
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/* Write to /dev/zero is ignored. */
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if (uio->uio_rw == UIO_WRITE) {
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uio->uio_resid = 0;
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return (0);
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}
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/*
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* On the first call, allocate and zero a page
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* of memory for use with /dev/zero.
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*/
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if (devzeropage == NULL) {
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devzeropage = (caddr_t)
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malloc(CLBYTES, M_TEMP, M_WAITOK);
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bzero(devzeropage, CLBYTES);
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}
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c = min(iov->iov_len, CLBYTES);
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error = uiomove(devzeropage, c, uio);
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break;
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default:
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return (ENXIO);
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}
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}
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/*
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* Note the different location of this label, compared with
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* other ports. This is because the /dev/mem to /dev/kmem
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* redirection above jumps here on error to do its unlock.
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*/
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unlock:
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if (minor(dev) == 0) {
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if (physlock > 1)
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wakeup((caddr_t)&physlock);
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physlock = 0;
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}
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return (error);
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}
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int
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mmmmap(dev, off, prot)
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dev_t dev;
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int off, prot;
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{
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register int v = off;
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/*
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* Check address validity.
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*/
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if (v & PGOFSET)
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return (-1);
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switch (minor(dev)) {
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case 0: /* dev/mem */
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/* Allow access only in valid memory. */
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if (!pmap_pa_exists(v))
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break;
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return (v);
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#if 0 /* XXX - NOTYET */
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case 5: /* dev/vme16d16 */
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if (v & 0xffff0000)
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break;
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v |= 0xff0000;
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/* fall through */
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case 6: /* dev/vme24d16 */
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if (v & 0xff000000)
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break;
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v |= 0xff000000;
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/* fall through */
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case 7: /* dev/vme32d16 */
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return (v | PMAP_VME16);
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case 8: /* dev/vme16d32 */
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if (v & 0xffff0000)
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break;
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v |= 0xff0000;
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/* fall through */
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case 9: /* dev/vme24d32 */
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if (v & 0xff000000)
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break;
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v |= 0xff000000;
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/* fall through */
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case 10: /* dev/vme32d32 */
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return (v | PMAP_VME32);
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#endif /* XXX */
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}
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return (-1);
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}
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/*
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* Just like kernacc(), but for the PROM mappings.
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* Return non-zero if access at VA is allowed.
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*/
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static int
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promacc(va, len, rw)
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caddr_t va;
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int len, rw;
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{
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vm_offset_t sva, eva;
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sva = (vm_offset_t)va;
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eva = (vm_offset_t)va + len;
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/* Test for the most common case first. */
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if (sva < PROM_BASE)
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return (0);
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/* Read in the PROM itself is OK. */
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if ((rw == B_READ) && (eva <= MONEND))
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return (1);
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/* PROM data page is OK for read/write. */
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if ((sva >= MONDATA) && (eva <= (MONDATA+NBPG)))
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return (1);
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/* otherwise, not OK to touch */
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return (0);
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}
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