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/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*
* @(#)vm_swap.c 8.5 (Berkeley) 2/17/94
* $Id: vm_swap.c,v 1.20 1995/05/25 03:38:11 davidg Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/proc.h>
#include <sys/namei.h>
#include <sys/dmap.h> /* XXX */
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/rlist.h>
#include <vm/vm.h>
#include <miscfs/specfs/specdev.h>
/*
* Indirect driver for multi-controller paging.
*/
#ifndef NSWAPDEV
#define NSWAPDEV 4
#endif
static struct swdevt should_be_malloced[NSWAPDEV];
struct swdevt *swdevt = should_be_malloced;
struct vnode *swapdev_vp;
int nswap; /* first block after the interleaved devs */
int nswdev = NSWAPDEV;
int vm_swap_size;
int bswneeded;
vm_offset_t swapbkva; /* swap buffers kva */
void
swstrategy(bp)
register struct buf *bp;
{
int sz, off, seg, index;
register struct swdevt *sp;
struct vnode *vp;
sz = howmany(bp->b_bcount, DEV_BSIZE);
if (nswdev > 1) {
off = bp->b_blkno % dmmax;
if (off + sz > dmmax) {
bp->b_error = EINVAL;
bp->b_flags |= B_ERROR;
biodone(bp);
return;
}
seg = bp->b_blkno / dmmax;
index = seg % nswdev;
seg /= nswdev;
bp->b_blkno = seg * dmmax + off;
} else
index = 0;
sp = &swdevt[index];
if (bp->b_blkno + sz > sp->sw_nblks) {
bp->b_error = EINVAL;
bp->b_flags |= B_ERROR;
biodone(bp);
return;
}
bp->b_dev = sp->sw_dev;
if (sp->sw_vp == NULL) {
bp->b_error = ENODEV;
bp->b_flags |= B_ERROR;
biodone(bp);
return;
}
VHOLD(sp->sw_vp);
if ((bp->b_flags & B_READ) == 0) {
vp = bp->b_vp;
if (vp) {
vp->v_numoutput--;
if ((vp->v_flag & VBWAIT) && vp->v_numoutput <= 0) {
vp->v_flag &= ~VBWAIT;
wakeup((caddr_t) &vp->v_numoutput);
}
}
sp->sw_vp->v_numoutput++;
}
if (bp->b_vp != NULL)
pbrelvp(bp);
bp->b_vp = sp->sw_vp;
VOP_STRATEGY(bp);
}
/*
* System call swapon(name) enables swapping on device name,
* which must be in the swdevsw. Return EBUSY
* if already swapping on this device.
*/
struct swapon_args {
char *name;
};
/* ARGSUSED */
int
swapon(p, uap, retval)
struct proc *p;
struct swapon_args *uap;
int *retval;
{
register struct vnode *vp;
register struct swdevt *sp;
dev_t dev;
int error,i;
struct nameidata nd;
struct vattr attr;
error = suser(p->p_ucred, &p->p_acflag);
if (error)
return (error);
NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, uap->name, p);
error = namei(&nd);
if (error)
return (error);
vp = nd.ni_vp;
switch (vp->v_type) {
case VBLK:
dev = (dev_t) vp->v_rdev;
if (major(dev) >= nblkdev) {
error = ENXIO;
break;
}
error = swaponvp(p, vp, dev, 0);
break;
case VCHR:
/*
* For now, we disallow swapping to regular files.
* It requires logical->physcal block translation
* support in the swap pager before it will work.
*/
error = ENOTBLK;
break;
#if 0
error = VOP_GETATTR(vp, &attr, p->p_ucred, p);
if (!error)
error = swaponvp(p, vp, NODEV, attr.va_size / DEV_BSIZE);
break;
#endif
default:
error = EINVAL;
break;
}
if (error)
vrele(vp);
return (error);
}
/*
* Swfree(index) frees the index'th portion of the swap map.
* Each of the nswdev devices provides 1/nswdev'th of the swap
* space, which is laid out with blocks of dmmax pages circularly
* among the devices.
*/
int
swaponvp(p, vp, dev, nblks)
struct proc *p;
struct vnode *vp;
dev_t dev;
u_long nblks;
{
int index;
register struct swdevt *sp;
register swblk_t vsbase;
register long blk;
swblk_t dvbase;
struct swdevt *swp;
int error;
int perdev;
for (sp = swdevt, index = 0 ; index < nswdev; index++, sp++) {
if (sp->sw_vp == vp)
return EBUSY;
if (!sp->sw_vp)
goto found;
}
return EINVAL;
found:
if (dev != NODEV && (major(dev) >= nblkdev))
return (ENXIO);
error = VOP_OPEN(vp, FREAD | FWRITE, p->p_ucred, p);
if (error)
return (error);
if (nblks == 0 && (bdevsw[major(dev)].d_psize == 0 ||
(nblks = (*bdevsw[major(dev)].d_psize) (dev)) == -1)) {
(void) VOP_CLOSE(vp, FREAD | FWRITE, p->p_ucred, p);
return (ENXIO);
}
if (nblks == 0) {
(void) VOP_CLOSE(vp, FREAD | FWRITE, p->p_ucred, p);
return (ENXIO);
}
sp->sw_vp = vp;
sp->sw_dev = dev;
sp->sw_flags |= SW_FREED;
sp->sw_nblks = nblks;
if (nblks * nswdev > nswap)
nswap = (nblks+1) * nswdev;
for (dvbase = dmmax; dvbase < nblks; dvbase += dmmax) {
blk = min(nblks - dvbase,dmmax);
vsbase = index * dmmax + dvbase * nswdev;
rlist_free(&swaplist, vsbase, vsbase + blk - 1);
vm_swap_size += blk;
}
if (!swapdev_vp && bdevvp(swapdev, &swapdev_vp))
panic("Cannot get vnode for swapdev");
return (0);
}
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