+/*
+ * 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 1.7 1994/01/17 09:32:59 davidg 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"
+
+/*
+ * Driver interface to do "raw" I/O in the address space of a
+ * user process directly for read and write operations..
+ */
+
+int
+rawread(dev, uio)
+ dev_t dev; struct uio *uio;
+{
+ return (uioapply(physio, (caddr_t) cdevsw[major(dev)].d_strategy,
+ (caddr_t) (u_long) dev, uio));
+}
+
+int
+rawwrite(dev, uio)
+ dev_t dev; struct uio *uio;
+{
+ return (uioapply(physio, (caddr_t) cdevsw[major(dev)].d_strategy,
+ (caddr_t) (u_long) dev, uio));
+}
+
+
+int physio(strat, dev, bp, off, rw, base, len, p)
+ d_strategy_t strat;
+ dev_t dev;
+ struct buf *bp;
+ int rw, off;
+ caddr_t base;
+ int *len;
+ struct proc *p;
+{
+ int amttodo = *len;
+ int error, amtdone;
+ vm_prot_t ftype;
+ vm_offset_t v, lastv;
+ caddr_t adr;
+ int oldflags;
+ int s;
+
+ int bp_alloc = (bp == 0);
+
+/*
+ * keep the process from being swapped
+ */
+ oldflags = p->p_flag;
+ p->p_flag |= SPHYSIO;
+
+ rw = rw == UIO_READ ? B_READ : 0;
+
+ /* create and build a buffer header for a transfer */
+
+ if (bp_alloc) {
+ bp = (struct buf *)getpbuf();
+ bzero((char *)bp, sizeof(*bp)); /* 09 Sep 92*/
+ } else {
+ s = 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(s);
+ }
+
+ 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)) {
+ error = EFAULT;
+ goto errrtn;
+ }
+ if (rw == B_WRITE && !useracc(base, bp->b_bcount, B_READ)) {
+ error = EFAULT;
+ goto errrtn;
+ }
+
+ /* update referenced and dirty bits, handle copy objects */
+ if (rw == B_READ)
+ ftype = VM_PROT_READ | VM_PROT_WRITE;
+ else
+ ftype = VM_PROT_READ;
+
+ lastv = 0;
+ for (adr = (caddr_t)trunc_page(base); adr < base + bp->b_bcount;
+ adr += NBPG) {
+
+/*
+ * make sure that the pde is valid and wired
+ */
+ v = trunc_page(((vm_offset_t)vtopte(adr)));
+ if (v != lastv) {
+ vm_map_pageable(&p->p_vmspace->vm_map, v,
+ round_page(v+1), FALSE);
+ lastv = v;
+ }
+
+/*
+ * do the vm_fault if needed, do the copy-on-write thing when
+ * reading stuff off device into memory.
+ */
+ if (ftype & VM_PROT_WRITE) {
+ /*
+ * properly handle copy-on-write
+ */
+ *(volatile int *) adr += 0;
+ }
+#if 0
+ else {
+ /*
+ * this clause is not really necessary because
+ * vslock does a vm_map_pageable FALSE.
+ * It is not optimally efficient to reference the
+ * page with the possiblity of it being paged out, but
+ * if this page is faulted here, it will be placed on the
+ * active queue, with the probability of it being paged
+ * out being very very low. This is here primarily for
+ * "symmetry".
+ */
+ *(volatile int *) adr;
+ }
+#endif
+ }
+/*
+ * if the process has been blocked by the wiring of the page table pages
+ * above or faults of other pages, then the vm_map_pageable contained in the
+ * vslock will fault the pages back in if they have been paged out since
+ * being referenced in the loop above. (vm_map_pageable calls vm_fault_wire
+ * which calls vm_fault to get the pages if needed.)
+ */
+
+ /* lock in core (perform vm_map_pageable, FALSE) */
+ vslock (base, bp->b_bcount);
+
+ /* perform transfer */
+ physstrat(bp, strat, PRIBIO);
+
+ /* unlock (perform vm_map_pageable, TRUE) */
+ vsunlock (base, bp->b_bcount, 0);
+
+ lastv = 0;
+
+/*
+ * unwire the pde
+ */
+ for (adr = (caddr_t)trunc_page(base); adr < base + bp->b_bcount;
+ adr += NBPG) {
+ v = trunc_page(((vm_offset_t)vtopte(adr)));
+ if (v != lastv) {
+ vm_map_pageable(&p->p_vmspace->vm_map, v, round_page(v+1), TRUE);
+ lastv = v;
+ }
+ }
+
+
+ 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;
+errrtn:
+ if (bp_alloc) {
+ relpbuf(bp);
+ } else {
+ bp->b_flags &= ~B_BUSY;
+ wakeup((caddr_t)bp);
+ }
+ *len = amttodo;
+
+/*
+ * allow the process to be swapped
+ */
+ p->p_flag &= ~SPHYSIO;
+ p->p_flag |= (oldflags & SPHYSIO);
+
+ return (error);
+}
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