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/*
* Copyright (c) 1994 John S. Dyson
* 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 immediately at the beginning of the file, without modification,
* 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. Absolutely no warranty of function or purpose is made by the author
* John S. Dyson.
* 4. Modifications may be freely made to this file if the above conditions
* are met.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/proc.h>
#include <sys/uio.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
static void
physwakeup(struct buf *bp)
{
wakeup(bp);
}
int
physio(dev_t dev, struct uio *uio, int ioflag)
{
int i;
int error;
int spl;
caddr_t sa;
u_int iolen;
struct buf *bp;
/* Keep the process UPAGES from being swapped. XXX: why ? */
PHOLD(curproc);
bp = getpbuf(NULL);
sa = bp->b_data;
error = bp->b_error = 0;
/* XXX: sanity check */
if(dev->si_iosize_max < PAGE_SIZE) {
printf("WARNING: %s si_iosize_max=%d, using DFLTPHYS.\n",
devtoname(dev), dev->si_iosize_max);
dev->si_iosize_max = DFLTPHYS;
}
for (i = 0; i < uio->uio_iovcnt; i++) {
while (uio->uio_iov[i].iov_len) {
bp->b_flags = B_PHYS;
if (uio->uio_rw == UIO_READ)
bp->b_iocmd = BIO_READ;
else
bp->b_iocmd = BIO_WRITE;
bp->b_dev = dev;
bp->b_iodone = physwakeup;
bp->b_data = uio->uio_iov[i].iov_base;
bp->b_bcount = uio->uio_iov[i].iov_len;
bp->b_offset = uio->uio_offset;
bp->b_saveaddr = sa;
/* Don't exceed drivers iosize limit */
if (bp->b_bcount > dev->si_iosize_max)
bp->b_bcount = dev->si_iosize_max;
/*
* Make sure the pbuf can map the request
* XXX: The pbuf has kvasize = MAXPHYS so a request
* XXX: larger than MAXPHYS - PAGE_SIZE must be
* XXX: page aligned or it will be fragmented.
*/
iolen = ((vm_offset_t) bp->b_data) & PAGE_MASK;
if ((bp->b_bcount + iolen) > bp->b_kvasize) {
bp->b_bcount = bp->b_kvasize;
if (iolen != 0)
bp->b_bcount -= PAGE_SIZE;
}
bp->b_bufsize = bp->b_bcount;
bp->b_blkno = btodb(bp->b_offset);
if (uio->uio_segflg == UIO_USERSPACE) {
/*
* Note that useracc() alone is not a
* sufficient test. vmapbuf() can still fail
* due to a smaller file mapped into a larger
* area of VM, or if userland races against
* vmapbuf() after the useracc() check.
*/
if (!useracc(bp->b_data, bp->b_bufsize,
bp->b_iocmd == BIO_READ ?
VM_PROT_WRITE : VM_PROT_READ)) {
error = EFAULT;
goto doerror;
}
if (vmapbuf(bp) < 0) {
error = EFAULT;
goto doerror;
}
}
DEV_STRATEGY(bp);
spl = splbio();
while ((bp->b_flags & B_DONE) == 0)
tsleep(bp, PRIBIO, "physstr", 0);
splx(spl);
if (uio->uio_segflg == UIO_USERSPACE)
vunmapbuf(bp);
iolen = bp->b_bcount - bp->b_resid;
if (iolen == 0 && !(bp->b_ioflags & BIO_ERROR))
goto doerror; /* EOF */
uio->uio_iov[i].iov_len -= iolen;
uio->uio_iov[i].iov_base =
(char *)uio->uio_iov[i].iov_base + iolen;
uio->uio_resid -= iolen;
uio->uio_offset += iolen;
if( bp->b_ioflags & BIO_ERROR) {
error = bp->b_error;
goto doerror;
}
}
}
doerror:
relpbuf(bp, NULL);
PRELE(curproc);
return (error);
}
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