NetBSD/sys/kern/kern__physio.c

154 lines
4.9 KiB
C

/*
* Copyright (c) 1989, 1990, 1991, 1992 William F. Jolitz, TeleMuse
* 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 software is a component of "386BSD" developed by
William F. Jolitz, TeleMuse.
* 4. Neither the name of the developer nor the name "386BSD"
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS A COMPONENT OF 386BSD DEVELOPED BY WILLIAM F. JOLITZ
* AND IS INTENDED FOR RESEARCH AND EDUCATIONAL PURPOSES ONLY. THIS
* SOFTWARE SHOULD NOT BE CONSIDERED TO BE A COMMERCIAL PRODUCT.
* THE DEVELOPER URGES THAT USERS WHO REQUIRE A COMMERCIAL PRODUCT
* NOT MAKE USE THIS WORK.
*
* FOR USERS WHO WISH TO UNDERSTAND THE 386BSD SYSTEM DEVELOPED
* BY WILLIAM F. JOLITZ, WE RECOMMEND THE USER STUDY WRITTEN
* REFERENCES SUCH AS THE "PORTING UNIX TO THE 386" SERIES
* (BEGINNING JANUARY 1991 "DR. DOBBS JOURNAL", USA AND BEGINNING
* JUNE 1991 "UNIX MAGAZIN", GERMANY) BY WILLIAM F. JOLITZ AND
* LYNNE GREER JOLITZ, AS WELL AS OTHER BOOKS ON UNIX AND THE
* ON-LINE 386BSD USER MANUAL BEFORE USE. A BOOK DISCUSSING THE INTERNALS
* OF 386BSD ENTITLED "386BSD FROM THE INSIDE OUT" WILL BE AVAILABLE LATE 1992.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``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 DEVELOPER 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.
*
* $Id: kern__physio.c,v 1.3 1993/05/20 02:54:15 cgd Exp $
*/
#include "param.h"
#include "systm.h"
#include "buf.h"
#include "conf.h"
#include "proc.h"
#include "malloc.h"
#include "vnode.h"
#include "vm/vm.h"
#include "specdev.h"
static physio(int (*)(), int, int, int, caddr_t, int *, struct proc *);
/*
* Driver interface to do "raw" I/O in the address space of a
* user process directly for read and write operations..
*/
rawread(dev, uio)
dev_t dev; struct uio *uio;
{
return (uioapply(physio, cdevsw[major(dev)].d_strategy, dev, uio));
}
rawwrite(dev, uio)
dev_t dev; struct uio *uio;
{
return (uioapply(physio, cdevsw[major(dev)].d_strategy, dev, uio));
}
static physio(strat, dev, off, rw, base, len, p)
int (*strat)();
dev_t dev;
int rw, off;
caddr_t base;
int *len;
struct proc *p;
{
register struct buf *bp;
int amttodo = *len, error, amtdone;
vm_prot_t ftype;
static zero;
caddr_t adr;
rw = rw == UIO_READ ? B_READ : 0;
/* create and build a buffer header for a transfer */
bp = (struct buf *)malloc(sizeof(*bp), M_TEMP, M_NOWAIT);
bzero((char *)bp, sizeof(*bp)); /* 09 Sep 92*/
bp->b_flags = B_BUSY | B_PHYS | rw;
bp->b_proc = p;
bp->b_dev = dev;
bp->b_error = 0;
bp->b_blkno = off/DEV_BSIZE;
amtdone = 0;
/* iteratively do I/O on as large a chunk as possible */
do {
bp->b_flags &= ~B_DONE;
bp->b_un.b_addr = base;
/* XXX limit */
bp->b_bcount = min (256*1024, amttodo);
/* first, check if accessible */
if (rw == B_READ && !useracc(base, bp->b_bcount, B_WRITE)) {
free(bp, M_TEMP);
return (EFAULT);
}
if (rw == B_WRITE && !useracc(base, bp->b_bcount, B_READ)) {
free(bp, M_TEMP);
return (EFAULT);
}
/* update referenced and dirty bits, handle copy objects */
if (rw == B_READ)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
/* 09 Sep 92*/ for (adr = (caddr_t)trunc_page(base); adr < base + bp->b_bcount;
adr += NBPG) {
vm_fault(&curproc->p_vmspace->vm_map,
adr, ftype, FALSE);
*(int *) adr += zero;
}
/* lock in core */
vslock (base, bp->b_bcount);
/* perform transfer */
physstrat(bp, strat, PRIBIO);
/* unlock */
vsunlock (base, bp->b_bcount, 0);
amtdone = bp->b_bcount - bp->b_resid;
amttodo -= amtdone;
base += amtdone;
bp->b_blkno += amtdone/DEV_BSIZE;
} while (amttodo && (bp->b_flags & B_ERROR) == 0 && amtdone > 0);
error = bp->b_error;
free(bp, M_TEMP);
*len = amttodo;
return (error);
}