/*
* 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
* $Id: device_pager.c,v 1.4 1994/10/02 17:48:58 phk Exp $
*/
/*
* Page to/from special files.
*/
#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 <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/device_pager.h>
struct pagerlst dev_pager_list; /* list of managed devices */
struct pglist dev_pager_fakelist; /* list of available vm_page_t's */
#ifdef DEBUG
int dpagerdebug = 0;
#define DDB_FOLLOW 0x01
#define DDB_INIT 0x02
#define DDB_ALLOC 0x04
#define DDB_FAIL 0x08
#endif
static vm_pager_t dev_pager_alloc __P((caddr_t, vm_size_t, vm_prot_t, vm_offset_t));
static void dev_pager_dealloc __P((vm_pager_t));
static int dev_pager_getpage __P((vm_pager_t, vm_page_t, boolean_t));
static boolean_t dev_pager_haspage __P((vm_pager_t, vm_offset_t));
static void dev_pager_init __P((void));
static int dev_pager_putpage __P((vm_pager_t, vm_page_t, boolean_t));
static vm_page_t dev_pager_getfake __P((vm_offset_t));
static void dev_pager_putfake __P((vm_page_t));
struct pagerops devicepagerops = {
dev_pager_init,
dev_pager_alloc,
dev_pager_dealloc,
dev_pager_getpage,
0,
dev_pager_putpage,
0,
dev_pager_haspage
};
static void
dev_pager_init()
{
#ifdef DEBUG
if (dpagerdebug & DDB_FOLLOW)
printf("dev_pager_init()\n");
#endif
TAILQ_INIT(&dev_pager_list);
TAILQ_INIT(&dev_pager_fakelist);
}
static vm_pager_t
dev_pager_alloc(handle, size, prot, foff)
caddr_t handle;
vm_size_t size;
vm_prot_t prot;
vm_offset_t foff;
{
dev_t dev;
vm_pager_t pager;
int (*mapfunc) ();
vm_object_t object;
dev_pager_t devp;
unsigned int npages, off;
#ifdef DEBUG
if (dpagerdebug & DDB_FOLLOW)
printf("dev_pager_alloc(%x, %x, %x, %x)\n",
handle, size, prot, foff);
#endif
#ifdef DIAGNOSTIC
/*
* Pageout to device, should never happen.
*/
if (handle == NULL)
panic("dev_pager_alloc called");
#endif
/*
* Make sure this device can be mapped.
*/
dev = (dev_t) (u_long) handle;
mapfunc = cdevsw[major(dev)].d_mmap;
if (mapfunc == NULL || mapfunc == enodev || mapfunc == nullop)
return (NULL);
/*
* Offset should be page aligned.
*/
if (foff & (PAGE_SIZE - 1))
return (NULL);
/*
* Check that the specified range of the device allows the desired
* protection.
*
* XXX assumes VM_PROT_* == PROT_*
*/
npages = atop(round_page(size));
for (off = foff; npages--; off += PAGE_SIZE)
if ((*mapfunc) (dev, off, (int) prot) == -1)
return (NULL);
/*
* Look up pager, creating as necessary.
*/
top:
pager = vm_pager_lookup(&dev_pager_list, handle);
if (pager == NULL) {
/*
* Allocate and initialize pager structs
*/
pager = (vm_pager_t) malloc(sizeof *pager, M_VMPAGER, M_WAITOK);
if (pager == NULL)
return (NULL);
devp = (dev_pager_t) malloc(sizeof *devp, M_VMPGDATA, M_WAITOK);
if (devp == NULL) {
free((caddr_t) pager, M_VMPAGER);
return (NULL);
}
pager->pg_handle = handle;
pager->pg_ops = &devicepagerops;
pager->pg_type = PG_DEVICE;
pager->pg_data = (caddr_t) devp;
TAILQ_INIT(&devp->devp_pglist);
/*
* Allocate object and associate it with the pager.
*/
object = devp->devp_object = vm_object_allocate(0);
vm_object_enter(object, pager);
vm_object_setpager(object, pager, (vm_offset_t) foff, FALSE);
/*
* Finally, put it on the managed list so other can find it.
* First we re-lookup in case someone else beat us to this
* point (due to blocking in the various mallocs). If so, we
* free everything and start over.
*/
if (vm_pager_lookup(&dev_pager_list, handle)) {
free((caddr_t) devp, M_VMPGDATA);
free((caddr_t) pager, M_VMPAGER);
goto top;
}
TAILQ_INSERT_TAIL(&dev_pager_list, pager, pg_list);
#ifdef DEBUG
if (dpagerdebug & DDB_ALLOC) {
printf("dev_pager_alloc: pager %x devp %x object %x\n",
pager, devp, object);
vm_object_print(object, FALSE);
}
#endif
} else {
/*
* vm_object_lookup() gains a reference and also removes the
* object from the cache.
*/
object = vm_object_lookup(pager);
#ifdef DIAGNOSTIC
devp = (dev_pager_t) pager->pg_data;
if (object != devp->devp_object)
panic("dev_pager_setup: bad object");
#endif
}
return (pager);
}
static void
dev_pager_dealloc(pager)
vm_pager_t pager;
{
dev_pager_t devp;
vm_object_t object;
vm_page_t m;
#ifdef DEBUG
if (dpagerdebug & DDB_FOLLOW)
printf("dev_pager_dealloc(%x)\n", pager);
#endif
TAILQ_REMOVE(&dev_pager_list, pager, pg_list);
/*
* Get the object. Note: cannot use vm_object_lookup since object has
* already been removed from the hash chain.
*/
devp = (dev_pager_t) pager->pg_data;
object = devp->devp_object;
#ifdef DEBUG
if (dpagerdebug & DDB_ALLOC)
printf("dev_pager_dealloc: devp %x object %x\n", devp, object);
#endif
/*
* Free up our fake pages.
*/
while ((m = devp->devp_pglist.tqh_first) != 0) {
TAILQ_REMOVE(&devp->devp_pglist, m, pageq);
dev_pager_putfake(m);
}
free((caddr_t) devp, M_VMPGDATA);
free((caddr_t) pager, M_VMPAGER);
}
static int
dev_pager_getpage(pager, m, sync)
vm_pager_t pager;
vm_page_t m;
boolean_t sync;
{
register vm_object_t object;
vm_offset_t offset, paddr;
vm_page_t page;
dev_t dev;
int s;
int (*mapfunc) (), prot;
#ifdef DEBUG
if (dpagerdebug & DDB_FOLLOW)
printf("dev_pager_getpage(%x, %x)\n", pager, m);
#endif
object = m->object;
dev = (dev_t) (u_long) pager->pg_handle;
offset = m->offset + object->paging_offset;
prot = PROT_READ; /* XXX should pass in? */
mapfunc = cdevsw[major(dev)].d_mmap;
if (mapfunc == NULL || mapfunc == enodev || mapfunc == nullop)
panic("dev_pager_getpage: no map function");
paddr = pmap_phys_address((*mapfunc) ((dev_t) dev, (int) offset, prot));
#ifdef DIAGNOSTIC
if (paddr == -1)
panic("dev_pager_getpage: map function returns error");
#endif
/*
* Replace the passed in page with our own fake page and free up the
* original.
*/
page = dev_pager_getfake(paddr);
TAILQ_INSERT_TAIL(&((dev_pager_t) pager->pg_data)->devp_pglist,
page, pageq);
vm_object_lock(object);
vm_page_lock_queues();
PAGE_WAKEUP(m);
vm_page_free(m);
vm_page_unlock_queues();
s = splhigh();
vm_page_insert(page, object, offset);
splx(s);
if (offset + PAGE_SIZE > object->size)
object->size = offset + PAGE_SIZE; /* XXX anal */
vm_object_unlock(object);
return (VM_PAGER_OK);
}
static int
dev_pager_putpage(pager, m, sync)
vm_pager_t pager;
vm_page_t m;
boolean_t sync;
{
#ifdef DEBUG
if (dpagerdebug & DDB_FOLLOW)
printf("dev_pager_putpage(%x, %x)\n", pager, m);
#endif
if (pager == NULL)
return 0;
panic("dev_pager_putpage called");
}
static boolean_t
dev_pager_haspage(pager, offset)
vm_pager_t pager;
vm_offset_t offset;
{
#ifdef DEBUG
if (dpagerdebug & DDB_FOLLOW)
printf("dev_pager_haspage(%x, %x)\n", pager, offset);
#endif
return (TRUE);
}
static vm_page_t
dev_pager_getfake(paddr)
vm_offset_t paddr;
{
vm_page_t m;
int i;
if (dev_pager_fakelist.tqh_first == 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 = dev_pager_fakelist.tqh_first;
TAILQ_REMOVE(&dev_pager_fakelist, m, pageq);
m->flags = PG_BUSY | PG_FICTITIOUS;
m->dirty = 0;
m->valid = VM_PAGE_BITS_ALL;
m->busy = 0;
m->bmapped = 0;
m->wire_count = 1;
m->phys_addr = paddr;
return (m);
}
static void
dev_pager_putfake(m)
vm_page_t m;
{
#ifdef DIAGNOSTIC
if (!(m->flags & PG_FICTITIOUS))
panic("dev_pager_putfake: bad page");
#endif
TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq);
}
