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Introduce uiomove_fromphys(). This is a variant of uiomove() that takes

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a collection of physical pages as the source.  On amd64 it is implemented
using the direct virtual-to-physical map.
This commit is contained in:
alc 2004-03-20 19:36:29 +00:00
parent 46693ffdb3
commit 927259311d
3 changed files with 135 additions and 0 deletions
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131
sys/amd64/amd64/uio_machdep.c Normal file
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@ -0,0 +1,131 @@
/*
* Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu>
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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.
*
* @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <machine/vmparam.h>
/*
* Implement uiomove(9) from physical memory using the direct map to
* avoid the creation and destruction of emphemeral mappings.
*/
int
uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio)
{
struct thread *td = curthread;
struct iovec *iov;
void *cp;
vm_offset_t page_offset;
size_t cnt;
int error = 0;
int save = 0;
KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
("uiomove_fromphys: mode"));
KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
("uiomove_fromphys proc"));
if (td != NULL) {
mtx_lock_spin(&sched_lock);
save = td->td_flags & TDF_DEADLKTREAT;
td->td_flags |= TDF_DEADLKTREAT;
mtx_unlock_spin(&sched_lock);
}
while (n > 0 && uio->uio_resid) {
iov = uio->uio_iov;
cnt = iov->iov_len;
if (cnt == 0) {
uio->uio_iov++;
uio->uio_iovcnt--;
continue;
}
if (cnt > n)
cnt = n;
page_offset = offset & PAGE_MASK;
cnt = min(cnt, PAGE_SIZE - page_offset);
cp = (char *)PHYS_TO_DMAP(ma[offset >> PAGE_SHIFT]->phys_addr) +
page_offset;
switch (uio->uio_segflg) {
case UIO_USERSPACE:
if (ticks - PCPU_GET(switchticks) >= hogticks)
uio_yield();
if (uio->uio_rw == UIO_READ)
error = copyout(cp, iov->iov_base, cnt);
else
error = copyin(iov->iov_base, cp, cnt);
if (error)
goto out;
break;
case UIO_SYSSPACE:
if (uio->uio_rw == UIO_READ)
bcopy(cp, iov->iov_base, cnt);
else
bcopy(iov->iov_base, cp, cnt);
break;
case UIO_NOCOPY:
break;
}
iov->iov_base = (char *)iov->iov_base + cnt;
iov->iov_len -= cnt;
uio->uio_resid -= cnt;
uio->uio_offset += cnt;
offset += cnt;
n -= cnt;
}
out:
if (td != NULL && save == 0) {
mtx_lock_spin(&sched_lock);
td->td_flags &= ~TDF_DEADLKTREAT;
mtx_unlock_spin(&sched_lock);
}
return (error);
}

1
sys/conf/files.amd64
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@ -75,6 +75,7 @@ amd64/amd64/support.S standard
amd64/amd64/sys_machdep.c standard
amd64/amd64/trap.c standard
amd64/amd64/tsc.c standard
amd64/amd64/uio_machdep.c standard
amd64/amd64/uma_machdep.c standard
amd64/amd64/vm_machdep.c standard
amd64/isa/atpic.c optional atpic isa

3
sys/sys/uio.h
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@ -84,6 +84,7 @@ struct uio {
#define UIO_SMALLIOV 8 /* 8 on stack, else malloc */
struct vm_object;
struct vm_page;
int copyinfrom(const void * __restrict src, void * __restrict dst,
size_t len, int seg);
@ -93,6 +94,8 @@ void uio_yield(void);
int uiofromiov(struct iovec *iovp, u_int iovcnt, struct uio *auio);
int uiomove(void *cp, int n, struct uio *uio);
int uiomove_frombuf(void *buf, int buflen, struct uio *uio);
int uiomove_fromphys(struct vm_page *ma[], vm_offset_t offset, int n,
struct uio *uio);
int uiomoveco(void *cp, int n, struct uio *uio, struct vm_object *obj,
int disposable);