diff options
Diffstat (limited to 'sys/kern/kern_physio.c')
| -rw-r--r-- | sys/kern/kern_physio.c | 200 |
1 files changed, 139 insertions, 61 deletions
diff --git a/sys/kern/kern_physio.c b/sys/kern/kern_physio.c index 1eaae35..9e0405f 100644 --- a/sys/kern/kern_physio.c +++ b/sys/kern/kern_physio.c @@ -1,41 +1,20 @@ -/*- - * Copyright (c) 1982, 1986, 1990, 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. +/* + * 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, this list of conditions and the following disclaimer. + * 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. 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. - * - * from: @(#)kern_physio.c 8.1 (Berkeley) 6/10/93 + * 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. */ #include <sys/param.h> @@ -43,51 +22,150 @@ #include <sys/buf.h> #include <sys/conf.h> #include <sys/proc.h> +#include <vm/vm.h> -physio(a1, a2, a3, a4, a5, a6) - int (*a1)(); - struct buf *a2; - dev_t a3; - int a4; - u_int (*a5)(); - struct uio *a6; +static void physwakeup(); + +int +physio(strategy, bp, dev, rw, minp, uio) + int (*strategy)(); + struct buf *bp; + dev_t dev; + int rw; + u_int (*minp)(); + struct uio *uio; { + int i; + int bp_alloc = (bp == 0); + int bufflags = rw?B_READ:0; + int error; + int spl; + +/* + * keep the process from being swapped + */ + curproc->p_flag |= P_PHYSIO; + + /* create and build a buffer header for a transfer */ + + if (bp_alloc) { + bp = (struct buf *)getpbuf(); + } else { + spl = splbio(); + while (bp->b_flags & B_BUSY) { + bp->b_flags |= B_WANTED; + tsleep((caddr_t)bp, PRIBIO, "physbw", 0); + } + bp->b_flags |= B_BUSY; + splx(spl); + } + + bp->b_proc = curproc; + bp->b_dev = dev; + error = bp->b_error = 0; + + for(i=0;i<uio->uio_iovcnt;i++) { + while( uio->uio_iov[i].iov_len) { + vm_offset_t v, lastv, pa; + caddr_t adr; + + bp->b_bcount = uio->uio_iov[i].iov_len; + bp->b_bufsize = bp->b_bcount; + bp->b_flags = B_BUSY | B_PHYS | B_CALL | bufflags; + bp->b_iodone = physwakeup; + bp->b_data = uio->uio_iov[i].iov_base; + bp->b_blkno = btodb(uio->uio_offset); + + + if (rw && !useracc(bp->b_data, bp->b_bufsize, B_WRITE)) { + error = EFAULT; + goto doerror; + } + if (!rw && !useracc(bp->b_data, bp->b_bufsize, B_READ)) { + error = EFAULT; + goto doerror; + } + + vmapbuf(bp); + + /* perform transfer */ + (*strategy)(bp); + + spl = splbio(); + while ((bp->b_flags & B_DONE) == 0) + tsleep((caddr_t)bp, PRIBIO, "physstr", 0); + splx(spl); - /* - * Body deleted. - */ - return (EIO); + vunmapbuf(bp); + + /* + * update the uio data + */ + { + int iolen = bp->b_bcount - bp->b_resid; + uio->uio_iov[i].iov_len -= iolen; + uio->uio_iov[i].iov_base += iolen; + uio->uio_resid -= iolen; + uio->uio_offset += iolen; + } + + /* + * check for an error + */ + if( bp->b_flags & B_ERROR) { + error = bp->b_error; + goto doerror; + } + } + } + + +doerror: + if (bp_alloc) { + relpbuf(bp); + } else { + bp->b_flags &= ~(B_BUSY|B_PHYS); + if( bp->b_flags & B_WANTED) { + bp->b_flags &= ~B_WANTED; + wakeup((caddr_t)bp); + } + } +/* + * allow the process to be swapped + */ + curproc->p_flag &= ~P_PHYSIO; + + return (error); } u_int -minphys(a1) - struct buf *a1; +minphys(struct buf *bp) { - /* - * Body deleted. - */ - return (0); + if( bp->b_bcount > MAXBSIZE) { + bp->b_bcount = MAXBSIZE; + } + return bp->b_bcount; } -/* - * Do a read on a device for a user process. - */ -rawread(dev, uio) - dev_t dev; - struct uio *uio; +int +rawread(dev_t dev, struct uio *uio) { return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL, - dev, B_READ, minphys, uio)); + dev, 1, minphys, uio)); } -/* - * Do a write on a device for a user process. - */ -rawwrite(dev, uio) - dev_t dev; - struct uio *uio; +int +rawwrite(dev_t dev, struct uio *uio) { return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL, - dev, B_WRITE, minphys, uio)); + dev, 0, minphys, uio)); +} + +static void +physwakeup(bp) + struct buf *bp; +{ + wakeup((caddr_t) bp); + bp->b_flags &= ~B_CALL; } |
