freebsd-dev/sys/vm/device_pager.c
Jordan K. Hubbard 1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00

299 lines
7.7 KiB
C

/*
* Copyright (c) 1990 University of Utah.
* Copyright (c) 1991, 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. 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.
*
* @(#)device_pager.c 8.1 (Berkeley) 6/11/93
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/mman.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_prot.h>
#include <vm/vm_kern.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/device_pager.h>
static void dev_pager_init __P((void));
static vm_object_t dev_pager_alloc __P((void *, vm_size_t, vm_prot_t,
vm_ooffset_t));
static void dev_pager_dealloc __P((vm_object_t));
static int dev_pager_getpages __P((vm_object_t, vm_page_t *, int, int));
static int dev_pager_putpages __P((vm_object_t, vm_page_t *, int,
boolean_t, int *));
static boolean_t dev_pager_haspage __P((vm_object_t, vm_pindex_t, int *,
int *));
/* list of device pager objects */
static struct pagerlst dev_pager_object_list;
/* list of available vm_page_t's */
static TAILQ_HEAD(, vm_page) dev_pager_fakelist;
static vm_page_t dev_pager_getfake __P((vm_offset_t));
static void dev_pager_putfake __P((vm_page_t));
static int dev_pager_alloc_lock, dev_pager_alloc_lock_want;
struct pagerops devicepagerops = {
dev_pager_init,
dev_pager_alloc,
dev_pager_dealloc,
dev_pager_getpages,
dev_pager_putpages,
dev_pager_haspage,
NULL
};
static void
dev_pager_init()
{
TAILQ_INIT(&dev_pager_object_list);
TAILQ_INIT(&dev_pager_fakelist);
}
static vm_object_t
dev_pager_alloc(handle, size, prot, foff)
void *handle;
vm_size_t size;
vm_prot_t prot;
vm_ooffset_t foff;
{
dev_t dev;
d_mmap_t *mapfunc;
vm_object_t object;
unsigned int npages, off;
/*
* Make sure this device can be mapped.
*/
dev = (dev_t) (u_long) handle;
mapfunc = cdevsw[major(dev)]->d_mmap;
if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) {
printf("obsolete map function %p\n", (void *)mapfunc);
return (NULL);
}
/*
* Offset should be page aligned.
*/
if (foff & PAGE_MASK)
return (NULL);
/*
* Check that the specified range of the device allows the desired
* protection.
*
* XXX assumes VM_PROT_* == PROT_*
*/
npages = size;
for (off = foff; npages--; off += PAGE_SIZE)
if ((*mapfunc) (dev, off, (int) prot) == -1)
return (NULL);
/*
* Lock to prevent object creation race contion.
*/
while (dev_pager_alloc_lock) {
dev_pager_alloc_lock_want++;
tsleep(&dev_pager_alloc_lock, PVM, "dvpall", 0);
dev_pager_alloc_lock_want--;
}
dev_pager_alloc_lock = 1;
/*
* Look up pager, creating as necessary.
*/
object = vm_pager_object_lookup(&dev_pager_object_list, handle);
if (object == NULL) {
/*
* Allocate object and associate it with the pager.
*/
object = vm_object_allocate(OBJT_DEVICE,
OFF_TO_IDX(foff) + size);
object->handle = handle;
TAILQ_INIT(&object->un_pager.devp.devp_pglist);
TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list);
} else {
/*
* Gain a reference to the object.
*/
vm_object_reference(object);
if (OFF_TO_IDX(foff) + size > object->size)
object->size = OFF_TO_IDX(foff) + size;
}
dev_pager_alloc_lock = 0;
if (dev_pager_alloc_lock_want)
wakeup(&dev_pager_alloc_lock);
return (object);
}
static void
dev_pager_dealloc(object)
vm_object_t object;
{
vm_page_t m;
TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
/*
* Free up our fake pages.
*/
while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) {
TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq);
dev_pager_putfake(m);
}
}
static int
dev_pager_getpages(object, m, count, reqpage)
vm_object_t object;
vm_page_t *m;
int count;
int reqpage;
{
vm_offset_t offset;
vm_offset_t paddr;
vm_page_t page;
dev_t dev;
int i, s;
d_mmap_t *mapfunc;
int prot;
dev = (dev_t) (u_long) object->handle;
offset = m[reqpage]->pindex + OFF_TO_IDX(object->paging_offset);
prot = PROT_READ; /* XXX should pass in? */
mapfunc = cdevsw[major(dev)]->d_mmap;
if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop)
panic("dev_pager_getpage: no map function");
paddr = pmap_phys_address((*mapfunc) ((dev_t) dev, (int) offset << PAGE_SHIFT, prot));
#ifdef DIAGNOSTIC
if (paddr == -1)
panic("dev_pager_getpage: map function returns error");
#endif
/*
* Replace the passed in reqpage page with our own fake page and free up the
* all of the original pages.
*/
page = dev_pager_getfake(paddr);
TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq);
for (i = 0; i < count; i++) {
PAGE_WAKEUP(m[i]);
vm_page_free(m[i]);
}
s = splhigh();
vm_page_insert(page, object, offset);
splx(s);
return (VM_PAGER_OK);
}
static int
dev_pager_putpages(object, m, count, sync, rtvals)
vm_object_t object;
vm_page_t *m;
int count;
boolean_t sync;
int *rtvals;
{
panic("dev_pager_putpage called");
}
static boolean_t
dev_pager_haspage(object, pindex, before, after)
vm_object_t object;
vm_pindex_t pindex;
int *before;
int *after;
{
if (before != NULL)
*before = 0;
if (after != NULL)
*after = 0;
return (TRUE);
}
static vm_page_t
dev_pager_getfake(paddr)
vm_offset_t paddr;
{
vm_page_t m;
int i;
if (TAILQ_FIRST(&dev_pager_fakelist) == NULL) {
m = (vm_page_t) malloc(PAGE_SIZE * 2, M_VMPGDATA, M_WAITOK);
for (i = (PAGE_SIZE * 2) / sizeof(*m); i > 0; i--) {
TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq);
m++;
}
}
m = TAILQ_FIRST(&dev_pager_fakelist);
TAILQ_REMOVE(&dev_pager_fakelist, m, pageq);
m->flags = PG_BUSY | PG_FICTITIOUS;
m->valid = VM_PAGE_BITS_ALL;
m->dirty = 0;
m->busy = 0;
m->queue = PQ_NONE;
m->wire_count = 1;
m->hold_count = 0;
m->phys_addr = paddr;
return (m);
}
static void
dev_pager_putfake(m)
vm_page_t m;
{
if (!(m->flags & PG_FICTITIOUS))
panic("dev_pager_putfake: bad page");
TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq);
}