* Copyright (c) 1989, 1990, 1991, 1992 William F. Jolitz, TeleMuse
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* 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
* $Id: kern__physio.c,v 1.6 1994/01/14 16:24:47 davidg Exp $
* Driver interface to do "raw" I/O in the address space of a
* user process directly for read and write operations..
dev_t dev
; struct uio
*uio
;
return (uioapply(physio
, (caddr_t
) cdevsw
[major(dev
)].d_strategy
,
(caddr_t
) (u_long
) 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
)
int bp_alloc
= (bp
== 0);
* keep the process from being swapped
rw
= rw
== UIO_READ
? B_READ
: 0;
/* create and build a buffer header for a transfer */
bp
= (struct buf
*)getpbuf();
bzero((char *)bp
, sizeof(*bp
)); /* 09 Sep 92*/
while (bp
->b_flags
& B_BUSY
) {
tsleep((caddr_t
)bp
, PRIBIO
, "physbw", 0);
bp
->b_flags
= B_BUSY
| B_PHYS
| rw
;
bp
->b_blkno
= off
/DEV_BSIZE
;
/* iteratively do I/O on as large a chunk as possible */
bp
->b_bcount
= min (256*1024, amttodo
);
/* first, check if accessible */
if (rw
== B_READ
&& !useracc(base
, bp
->b_bcount
, B_WRITE
)) {
if (rw
== B_WRITE
&& !useracc(base
, bp
->b_bcount
, B_READ
)) {
/* update referenced and dirty bits, handle copy objects */
ftype
= VM_PROT_READ
| VM_PROT_WRITE
;
for (adr
= (caddr_t
)trunc_page(base
); adr
< base
+ bp
->b_bcount
;
* make sure that the pde is valid and wired
v
= trunc_page(((vm_offset_t
)vtopte(adr
)));
vm_map_pageable(&p
->p_vmspace
->vm_map
, 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;
* 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
* 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
);
physstrat(bp
, strat
, PRIBIO
);
/* unlock (perform vm_map_pageable, TRUE) */
vsunlock (base
, bp
->b_bcount
, 0);
for (adr
= (caddr_t
)trunc_page(base
); adr
< base
+ bp
->b_bcount
;
v
= trunc_page(((vm_offset_t
)vtopte(adr
)));
vm_map_pageable(&p
->p_vmspace
->vm_map
, v
, round_page(v
+1), TRUE
);
amtdone
= bp
->b_bcount
- bp
->b_resid
;
bp
->b_blkno
+= amtdone
/DEV_BSIZE
;
} while (amttodo
&& (bp
->b_flags
& B_ERROR
) == 0 && amtdone
> 0);
* allow the process to be swapped
p
->p_flag
|= (oldflags
& SPHYSIO
);