freebsd-dev/sys/i386/i386/mem.c
2001-05-21 18:52:02 +00:00

369 lines
9.1 KiB
C

/*-
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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
* $FreeBSD$
*/
/*
* 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/mutex.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <machine/db_machdep.h>
#include <machine/frame.h>
#include <machine/psl.h>
#include <machine/specialreg.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
static dev_t memdev, kmemdev, iodev;
static d_open_t mmopen;
static d_close_t mmclose;
static d_read_t mmrw;
static d_ioctl_t mmioctl;
static d_mmap_t memmmap;
#define CDEV_MAJOR 2
static struct cdevsw mem_cdevsw = {
/* open */ mmopen,
/* close */ mmclose,
/* read */ mmrw,
/* write */ mmrw,
/* ioctl */ mmioctl,
/* poll */ (d_poll_t *)seltrue,
/* mmap */ memmmap,
/* strategy */ nostrategy,
/* name */ "mem",
/* maj */ CDEV_MAJOR,
/* dump */ nodump,
/* psize */ nopsize,
/* flags */ D_MEM,
};
MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
struct mem_range_softc mem_range_softc;
static int
mmclose(dev_t dev, int flags, int fmt, struct proc *p)
{
switch (minor(dev)) {
case 14:
p->p_md.md_regs->tf_eflags &= ~PSL_IOPL;
}
return (0);
}
static int
mmopen(dev_t dev, int flags, int fmt, struct proc *p)
{
int error;
switch (minor(dev)) {
case 0:
case 1:
if ((flags & FWRITE) && securelevel > 0)
return (EPERM);
break;
case 14:
error = suser(p);
if (error != 0)
return (error);
if (securelevel > 0)
return (EPERM);
p->p_md.md_regs->tf_eflags |= PSL_IOPL;
break;
}
return (0);
}
/*ARGSUSED*/
static int
mmrw(dev_t dev, struct uio *uio, int flags)
{
int o;
u_int c = 0, v;
struct iovec *iov;
int error = 0;
vm_offset_t addr, eaddr;
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;
v &= ~PAGE_MASK;
mtx_lock(&vm_mtx);
pmap_kenter((vm_offset_t)ptvmmap, v);
mtx_unlock(&vm_mtx);
o = (int)uio->uio_offset & PAGE_MASK;
c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK));
c = min(c, (u_int)(PAGE_SIZE - o));
c = min(c, (u_int)iov->iov_len);
error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio);
mtx_lock(&vm_mtx);
pmap_kremove((vm_offset_t)ptvmmap);
mtx_unlock(&vm_mtx);
continue;
/* minor device 1 is kernel memory */
case 1:
c = iov->iov_len;
/*
* Make sure that all of the pages are currently resident so
* that we don't create any zero-fill pages.
*/
addr = trunc_page(uio->uio_offset);
eaddr = round_page(uio->uio_offset + c);
if (addr < (vm_offset_t)VADDR(PTDPTDI, 0))
return EFAULT;
if (eaddr >= (vm_offset_t)VADDR(APTDPTDI, 0))
return EFAULT;
mtx_lock(&vm_mtx);
for (; addr < eaddr; addr += PAGE_SIZE)
if (pmap_extract(kernel_pmap, addr) == 0) {
mtx_unlock(&vm_mtx);
return EFAULT;
}
if (!kernacc((caddr_t)(int)uio->uio_offset, c,
uio->uio_rw == UIO_READ ?
VM_PROT_READ : VM_PROT_WRITE)) {
mtx_unlock(&vm_mtx);
return (EFAULT);
}
mtx_unlock(&vm_mtx);
error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio);
continue;
}
if (error)
break;
iov->iov_base += c;
iov->iov_len -= c;
uio->uio_offset += c;
uio->uio_resid -= c;
}
return (error);
}
/*******************************************************\
* allow user processes to MMAP some memory sections *
* instead of going through read/write *
\*******************************************************/
static int
memmmap(dev_t dev, vm_offset_t offset, int prot)
{
switch (minor(dev))
{
/* minor device 0 is physical memory */
case 0:
return i386_btop(offset);
/* minor device 1 is kernel memory */
case 1:
return i386_btop(vtophys(offset));
default:
return -1;
}
}
/*
* Operations for changing memory attributes.
*
* This is basically just an ioctl shim for mem_range_attr_get
* and mem_range_attr_set.
*/
static int
mmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
{
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);
}
/*
* Implementation-neutral, kernel-callable functions for manipulating
* memory range attributes.
*/
int
mem_range_attr_get(struct mem_range_desc *mrd, int *arg)
{
/* can we handle this? */
if (mem_range_softc.mr_op == NULL)
return (EOPNOTSUPP);
if (*arg == 0) {
*arg = mem_range_softc.mr_ndesc;
}
else {
bcopy(mem_range_softc.mr_desc, mrd,
(*arg) * sizeof(struct mem_range_desc));
}
return (0);
}
int
mem_range_attr_set(struct mem_range_desc *mrd, int *arg)
{
/* can we handle this? */
if (mem_range_softc.mr_op == NULL)
return (EOPNOTSUPP);
return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg));
}
#ifdef SMP
void
mem_range_AP_init(void)
{
if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP)
return (mem_range_softc.mr_op->initAP(&mem_range_softc));
}
#endif
static int
mem_modevent(module_t mod, int type, void *data)
{
switch(type) {
case MOD_LOAD:
if (bootverbose)
printf("mem: <memory & I/O>\n");
/* Initialise memory range handling */
if (mem_range_softc.mr_op != NULL)
mem_range_softc.mr_op->init(&mem_range_softc);
memdev = make_dev(&mem_cdevsw, 0, UID_ROOT, GID_KMEM,
0640, "mem");
kmemdev = make_dev(&mem_cdevsw, 1, UID_ROOT, GID_KMEM,
0640, "kmem");
iodev = make_dev(&mem_cdevsw, 14, UID_ROOT, GID_WHEEL,
0600, "io");
return 0;
case MOD_UNLOAD:
destroy_dev(memdev);
destroy_dev(kmemdev);
destroy_dev(iodev);
return 0;
case MOD_SHUTDOWN:
return 0;
default:
return EOPNOTSUPP;
}
}
DEV_MODULE(mem, mem_modevent, NULL);