freebsd-dev/sys/scsi/su.c
Julian Elischer f7ea2f55d1 There is no such thing any more as "struct bdevsw".
There is only cdevsw (which should be renamed in a later edit to deventry
or something). cdevsw contains the union of what were in both bdevsw an
cdevsw entries.  The bdevsw[] table stiff exists and is a second pointer
to the cdevsw entry of the device. it's major is in d_bmaj rather than
d_maj. some cleanup still to happen (e.g. dsopen now gets two pointers
to the same cdevsw struct instead of one to a bdevsw and one to a cdevsw).

rawread()/rawwrite() went away as part of this though it's not strictly
the same  patch, just that it involves all the same lines in the drivers.

cdroms no longer have write() entries (they did have rawwrite (?)).
tapes no longer have support for bdev operations.

Reviewed by: Eivind Eklund and Mike Smith
	Changes suggested by eivind.
1998-07-04 22:30:26 +00:00

283 lines
6.9 KiB
C

/* su: SCSI Universal. This is a universal SCSI device that
* has a fixed minor number format. This allows you to refer
* to your devices by BUS, ID, LUN instead of st0, st1, ...
*
* This code looks up the underlying device for a given SCSI
* target and uses that driver.
*
*Begin copyright
*
* Copyright (C) 1993, 1994, 1995, HD Associates, Inc.
* PO Box 276
* Pepperell, MA 01463
* 508 433 5266
* dufault@hda.com
*
* This code is contributed to the University of California at Berkeley:
*
* 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 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.
*End copyright
*
* $Id: su.c,v 1.19 1998/06/07 17:12:54 dfr Exp $
*
* Tabstops 4
* XXX devfs entries for this device should be handled by generic scsiconfig
* Add a bdevsw interface.. ?
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/kernel.h>
#include <scsi/scsiconf.h>
#define CDEV_MAJOR 18
/* These three used by ssc. */
extern d_open_t suopen;
extern d_close_t suclose;
extern d_ioctl_t suioctl;
static d_read_t suread;
static d_write_t suwrite;
static d_poll_t supoll;
static d_strategy_t sustrategy;
static struct cdevsw su_cdevsw =
{ suopen, suclose, suread, suwrite, /*18*/
suioctl, nostop, nullreset, nodevtotty,/* scsi */
supoll, nommap, sustrategy, "su", NULL, -1 };
/* Build an old style device number (unit encoded in the minor number)
* from a base old one (no flag bits) and a full new one
* (BUS, LUN, TARG in the minor number, and flag bits).
*
* OLDDEV has the major number and device unit only. It was constructed
* at attach time and is stored in the scsi_link structure.
*
* NEWDEV can have whatever in it, but only the old control flags and the
* super bit are present. IT CAN'T HAVE ANY UNIT INFORMATION or you'll
* wind up with the wrong unit.
*/
#define OLD_DEV(NEWDEV, OLDDEV) ((OLDDEV) | ((NEWDEV) & 0x080000FF))
/* bnxio, cnxio: non existent device entries
*/
static struct cdevsw cnxio = {
nxopen,
nxclose,
nxread,
nxwrite,
nxioctl,
nxstop,
nxreset,
nxdevtotty,
seltrue,
nxmmap,
nxstrategy,
"NON",
NULL,
-1,
nxdump,
nxpsize,
0,
0,
-1
};
/* getsws: Look up the base dev switch for a given "by minor number" style
* device.
*/
static int
getsws(dev_t dev, int type, struct cdevsw **devswpp, dev_t *base)
{
int ret = 0;
struct scsi_link *scsi_link;
int chr_dev, blk_dev;
struct cdevsw *devswp;
int bus = SCSI_BUS(dev),
lun = SCSI_LUN(dev),
id = SCSI_ID(dev);
/* Try to look up the base device by finding the major number in
* the scsi_link structure:
*/
if ((scsi_link = scsi_link_get(bus, id, lun)) == 0 ||
scsi_link->dev == NODEV)
{
ret = ENXIO;
devswp = &cnxio;
chr_dev = NODEV;
blk_dev = NODEV;
}
else
{
int bmaj, cmaj;
cmaj = major(scsi_link->dev);
devswp = cdevsw[cmaj];
chr_dev = OLD_DEV(dev, scsi_link->dev);
bmaj = devswp->d_bmaj;
blk_dev = OLD_DEV(dev, makedev(bmaj, minor(scsi_link->dev)));
}
if (devswp)
*devswpp = devswp;
if (type == S_IFCHR)
*base = chr_dev;
else
*base = blk_dev;
return ret;
}
int
suopen(dev_t dev, int flag, int type, struct proc *p)
{
struct cdevsw *devswp;
dev_t base;
if (getsws(dev, type, &devswp, &base))
{
/* Device not configured? Reprobe then try again.
*/
int bus = SCSI_BUS(dev), lun = SCSI_LUN(dev), id = SCSI_ID(dev);
if (scsi_probe_bus(bus, id, lun) || getsws(dev, type, &devswp,
&base))
return ENXIO;
}
/* There is a properly configured underlying device.
* Synthesize an appropriate device number:
*/
return (*devswp->d_open)(base, flag, type, p);
}
int
suclose(dev_t dev, int fflag, int type, struct proc *p)
{
struct cdevsw *devswp;
dev_t base;
(void)getsws(dev, type, &devswp, &base);
return (*devswp->d_close)(base, fflag, type, p);
}
static void
sustrategy(struct buf *bp)
{
dev_t base;
struct cdevsw *devswp;
dev_t dev = bp->b_dev;
/* XXX: I have no way of knowing if this was through the
* block or the character entry point.
*/
(void)getsws(dev, S_IFBLK, &devswp, &base);
bp->b_dev = base;
(*devswp->d_strategy)(bp);
bp->b_dev = dev; /* strat needs a dev_t */
}
int
suioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct proc *p)
{
struct cdevsw *devswp;
dev_t base;
/* XXX: I have no way of knowing if this was through the
* block or the character entry point.
*/
(void)getsws(dev, S_IFCHR, &devswp, &base);
return (*devswp->d_ioctl)(base, cmd, data, fflag, p);
}
static int
suread(dev_t dev, struct uio *uio, int ioflag)
{
dev_t base;
struct cdevsw *devswp;
(void)getsws(dev, S_IFCHR, &devswp, &base);
return (*devswp->d_read)(base, uio, ioflag);
}
static int
suwrite(dev_t dev, struct uio *uio, int ioflag)
{
dev_t base;
struct cdevsw *devswp;
(void)getsws(dev, S_IFCHR, &devswp, &base);
return (*devswp->d_write)(base, uio, ioflag);
}
static int
supoll(dev_t dev, int events, struct proc *p)
{
dev_t base;
struct cdevsw *devswp;
(void)getsws(dev, S_IFCHR, &devswp, &base);
return (*devswp->d_poll)(base, events, p);
}
static su_devsw_installed = 0;
static void
su_drvinit(void *unused)
{
dev_t dev;
if( ! su_devsw_installed ) {
dev = makedev(CDEV_MAJOR, 0);
cdevsw_add(&dev,&su_cdevsw, NULL);
su_devsw_installed = 1;
}
}
SYSINIT(sudev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,su_drvinit,NULL)