f-stack/freebsd/amd64/amd64/mem.c

240 lines
6.4 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1982, 1986, 1990 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, and code derived from software contributed to
* Berkeley by William Jolitz.
*
* 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.
*
* from: Utah $Hdr: mem.c 1.13 89/10/08$
* from: @(#)mem.c 7.2 (Berkeley) 5/9/91
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Memory special file
*/
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/ioccom.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/memrange.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <machine/md_var.h>
#include <machine/specialreg.h>
#include <machine/vmparam.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <machine/memdev.h>
/*
* Used in /dev/mem drivers and elsewhere
*/
MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
/* ARGSUSED */
int
memrw(struct cdev *dev, struct uio *uio, int flags)
{
struct iovec *iov;
void *p;
ssize_t orig_resid;
u_long v, vd;
u_int c;
int error;
error = 0;
orig_resid = uio->uio_resid;
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("memrw");
continue;
}
v = uio->uio_offset;
c = ulmin(iov->iov_len, PAGE_SIZE - (u_int)(v & PAGE_MASK));
switch (dev2unit(dev)) {
case CDEV_MINOR_KMEM:
/*
* Since c is clamped to be less or equal than
* PAGE_SIZE, the uiomove() call does not
* access past the end of the direct map.
*/
if (v >= DMAP_MIN_ADDRESS &&
v < DMAP_MIN_ADDRESS + dmaplimit) {
error = uiomove((void *)v, c, uio);
break;
}
if (!kernacc((void *)v, c, uio->uio_rw == UIO_READ ?
VM_PROT_READ : VM_PROT_WRITE)) {
error = EFAULT;
break;
}
/*
* If the extracted address is not accessible
* through the direct map, then we make a
* private (uncached) mapping because we can't
* depend on the existing kernel mapping
* remaining valid until the completion of
* uiomove().
*
* XXX We cannot provide access to the
* physical page 0 mapped into KVA.
*/
v = pmap_extract(kernel_pmap, v);
if (v == 0) {
error = EFAULT;
break;
}
/* FALLTHROUGH */
case CDEV_MINOR_MEM:
if (v < dmaplimit) {
vd = PHYS_TO_DMAP(v);
error = uiomove((void *)vd, c, uio);
break;
}
if (v > cpu_getmaxphyaddr()) {
error = EFAULT;
break;
}
p = pmap_mapdev(v, PAGE_SIZE);
error = uiomove(p, c, uio);
pmap_unmapdev((vm_offset_t)p, PAGE_SIZE);
break;
}
}
/*
* Don't return error if any byte was written. Read and write
* can return error only if no i/o was performed.
*/
if (uio->uio_resid != orig_resid)
error = 0;
return (error);
}
/*
* allow user processes to MMAP some memory sections
* instead of going through read/write
*/
/* ARGSUSED */
int
memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
int prot __unused, vm_memattr_t *memattr __unused)
{
if (dev2unit(dev) == CDEV_MINOR_MEM) {
if (offset > cpu_getmaxphyaddr())
return (-1);
*paddr = offset;
return (0);
}
return (-1);
}
/*
* Operations for changing memory attributes.
*
* This is basically just an ioctl shim for mem_range_attr_get
* and mem_range_attr_set.
*/
int
memioctl_md(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
struct thread *td)
{
int nd, error = 0;
struct mem_range_op *mo = (struct mem_range_op *)data;
struct mem_range_desc *md;
/* is this for us? */
if ((cmd != MEMRANGE_GET) &&
(cmd != MEMRANGE_SET))
return (ENOTTY);
/* any chance we can handle this? */
if (mem_range_softc.mr_op == NULL)
return (EOPNOTSUPP);
/* do we have any descriptors? */
if (mem_range_softc.mr_ndesc == 0)
return (ENXIO);
switch (cmd) {
case MEMRANGE_GET:
nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
if (nd > 0) {
md = (struct mem_range_desc *)
malloc(nd * sizeof(struct mem_range_desc),
M_MEMDESC, M_WAITOK);
error = mem_range_attr_get(md, &nd);
if (!error)
error = copyout(md, mo->mo_desc,
nd * sizeof(struct mem_range_desc));
free(md, M_MEMDESC);
}
else
nd = mem_range_softc.mr_ndesc;
mo->mo_arg[0] = nd;
break;
case MEMRANGE_SET:
md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
M_MEMDESC, M_WAITOK);
error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
/* clamp description string */
md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
if (error == 0)
error = mem_range_attr_set(md, &mo->mo_arg[0]);
free(md, M_MEMDESC);
break;
}
return (error);
}