freebsd-skq/sys/scsi/worm.c
1995-12-08 23:23:00 +00:00

395 lines
10 KiB
C

/*
* worm: Write Once device driver
*
* Copyright (C) 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.
*
* $Id: worm.c,v 1.14 1995/12/08 11:19:07 julian Exp $
*/
/* XXX This is PRELIMINARY.
*
* We need the "kern devconf" stuff, but I'm not
* going to add it until it is done in a simple way that provides
* base behavior in scsi_driver.c
*
* Until Bruce finishes the slice stuff there will be no partitions.
* When it is finished I hope to hoist the partition code up into
* "scsi_driver" and use common code for all devices.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#ifdef DEVFS
#include <sys/devfsext.h>
#endif /*DEVFS*/
#include <scsi/scsi_all.h>
#include <scsi/scsiconf.h>
#include <scsi/scsi_disk.h>
struct scsi_data {
struct buf_queue_head buf_queue;
u_int32 n_blks; /* Number of blocks (0 for bogus) */
u_int32 blk_size; /* Size of each blocks */
#ifdef DEVFS
void *devfs_token; /* more elaborate later */
#endif
};
static void wormstart(u_int32 unit, u_int32 flags);
static errval worm_open(dev_t dev, int flags, int fmt, struct proc *p,
struct scsi_link *sc_link);
static errval worm_ioctl(dev_t dev, int cmd, caddr_t addr, int flag,
struct proc *p, struct scsi_link *sc_link);
static errval worm_close(dev_t dev, int flag, int fmt, struct proc *p,
struct scsi_link *sc_link);
static void worm_strategy(struct buf *bp, struct scsi_link *sc_link);
static d_open_t wormopen;
static d_close_t wormclose;
static d_ioctl_t wormioctl;
d_strategy_t wormstrategy;
#define CDEV_MAJOR 62
static struct cdevsw worm_cdevsw =
{ wormopen, wormclose, rawread, rawwrite, /*62*/
wormioctl, nostop, nullreset, nodevtotty,/* worm */
seltrue, nommap, wormstrategy };
SCSI_DEVICE_ENTRIES(worm)
static struct scsi_device worm_switch =
{
NULL,
wormstart, /* we have a queue, and this is how we service it */
NULL,
NULL,
"worm",
0,
{0, 0},
SDEV_ONCE_ONLY, /* Only one open allowed */
wormattach,
"Write-Once",
wormopen,
sizeof(struct scsi_data),
T_WORM,
0,
0,
worm_open,
0,
worm_close,
worm_strategy,
};
static int worm_size(struct scsi_link *sc_link, int flags)
{
int ret;
struct scsi_data *worm = sc_link->sd;
worm->n_blks = scsi_read_capacity(sc_link, &worm->blk_size,
flags);
if(worm->blk_size == 0)
/* XXX */
worm->blk_size = 2048;
if (worm->n_blks)
{
sc_link->flags |= SDEV_MEDIA_LOADED;
ret = 1;
}
else
{
sc_link->flags &= ~SDEV_MEDIA_LOADED;
ret = 0;
}
return ret;
}
static errval
wormattach(struct scsi_link *sc_link)
{
struct scsi_data *worm = sc_link->sd;
TAILQ_INIT(&worm->buf_queue);
printf("- UNTESTED ");
if (worm_size(sc_link, SCSI_NOSLEEP | SCSI_NOMASK) == 0)
printf("- can't get capacity.");
else
printf("with %ld %ld byte blocks.",
worm->n_blks, worm->blk_size);
#ifdef DEVFS
worm->devfs_token = devfs_add_devsw( "/", "rworm", &worm_cdevsw, 0,
DV_CHR, 0, 0, 0600);
#endif
return 0;
}
/*
* wormstart looks to see if there is a buf waiting for the device
* and that the device is not already busy. If both are true,
* It dequeues the buf and creates a scsi command to perform the
* transfer required. The transfer request will call scsi_done
* on completion, which will in turn call this routine again
* so that the next queued transfer is performed.
* The bufs are queued by the strategy routine (wormstrategy)
*
* This routine is also called after other non-queued requests
* have been made of the scsi driver, to ensure that the queue
* continues to be drained.
* wormstart() is called at splbio
*
* XXX It looks like we need a "scsistart" to hoist common code up
* into. In particular, the removable media checking should be
* handled in one place.
*/
static void
wormstart(unit, flags)
u_int32 unit;
u_int32 flags;
{
struct scsi_link *sc_link = SCSI_LINK(&worm_switch, unit);
struct scsi_data *worm = sc_link->sd;
register struct buf *bp = 0;
struct scsi_rw_big cmd;
u_int32 lba; /* Logical block address */
u_int32 tl; /* Transfer length */
SC_DEBUG(sc_link, SDEV_DB2, ("wormstart "));
/*
* We should reject all queued entries if SDEV_MEDIA_LOADED is not true.
*/
if (!(sc_link->flags & SDEV_MEDIA_LOADED)) {
goto badnews; /* no I/O.. media changed or something */
}
/*
* See if there is a buf to do and we are not already
* doing one
*/
while (sc_link->opennings != 0) {
/* if a special awaits, let it proceed first */
if (sc_link->flags & SDEV_WAITING) {
sc_link->flags &= ~SDEV_WAITING;
wakeup(sc_link);
return;
}
bp = worm->buf_queue.tqh_first;
if (bp == NULL) { /* yes, an assign */
return;
}
TAILQ_REMOVE( &worm->buf_queue, bp, b_act);
/*
* Fill out the scsi command
*/
bzero(&cmd, sizeof(cmd));
if ((bp->b_flags & B_READ) == B_WRITE) {
cmd.op_code = WRITE_BIG;
flags |= SCSI_DATA_OUT;
} else {
cmd.op_code = READ_BIG;
flags |= SCSI_DATA_IN;
}
lba = bp->b_blkno / (worm->blk_size / DEV_BSIZE);
tl = bp->b_bcount / worm->blk_size;
scsi_uto4b(lba, &cmd.addr_3);
scsi_uto2b(tl, &cmd.length2);
/*
* go ask the adapter to do all this for us
*/
if (scsi_scsi_cmd(sc_link,
(struct scsi_generic *) &cmd,
sizeof(cmd),
(u_char *) bp->b_un.b_addr,
bp->b_bcount,
0, /* can't retry a read on a tape really */
100000,
bp,
flags | SCSI_NOSLEEP) == SUCCESSFULLY_QUEUED) {
} else {
printf("worm%ld: oops not queued\n", unit);
if (bp) {
bp->b_flags |= B_ERROR;
bp->b_error = EIO;
biodone(bp);
}
}
} /* go back and see if we can cram more work in.. */
badnews:
}
static void
worm_strategy(struct buf *bp, struct scsi_link *sc_link)
{
struct buf **dp;
unsigned char unit;
u_int32 opri;
struct scsi_data *worm;
unit = minor((bp->b_dev));
worm = sc_link->sd;
/* XXX: Can't we move this check up to "scsi_strategy"?
*/
if (!(sc_link->flags & SDEV_MEDIA_LOADED) ||
bp->b_blkno > worm->n_blks ||
bp->b_bcount & (worm->blk_size - 1)) {
bp->b_error = EIO;
bp->b_flags |= B_ERROR;
biodone(bp);
return;
}
opri = splbio();
/*
* Use a bounce buffer if necessary
* XXX: How can we move this up?
*/
#ifdef BOUNCE_BUFFERS
if (sc_link->flags & SDEV_BOUNCE)
vm_bounce_alloc(bp);
#endif
/*
* Place it in the queue of activities for this device
* at the end.
*/
TAILQ_INSERT_TAIL(&worm->buf_queue, bp, b_act);
wormstart(unit, 0);
splx(opri);
return;
}
/*
* Open the device. XXX: I'm completely guessing at this sequence.
*/
static int
worm_open(dev_t dev, int flags, int fmt, struct proc *p,
struct scsi_link *sc_link)
{
if (sc_link->flags & SDEV_OPEN)
return EBUSY;
/*
* Check that it is still responding and ok.
* if the media has been changed this will result in a
* "unit attention" error which the error code will
* disregard because the SDEV_OPEN flag is not yet set
*
* XXX This should REALLY be hoisted up. As soon as Bruce
* finishes that slice stuff. (Add a different flag,
* and then do a "scsi_test_unit_ready" with the "ignore
* unit attention" thing set. Then all this replicated
* test unit ready code can be pulled up.
*/
scsi_test_unit_ready(sc_link, SCSI_SILENT);
/*
* Next time actually take notice of error returns
*/
sc_link->flags |= SDEV_OPEN; /* unit attn errors are now errors */
if (scsi_test_unit_ready(sc_link, SCSI_SILENT) != 0) {
SC_DEBUG(sc_link, SDEV_DB3, ("not ready\n"));
sc_link->flags &= ~SDEV_OPEN;
return ENXIO;
}
scsi_start_unit(sc_link, SCSI_SILENT);
scsi_prevent(sc_link, PR_PREVENT, SCSI_SILENT);
if (worm_size(sc_link, 0) == 0) {
scsi_stop_unit(sc_link, 0, SCSI_SILENT);
scsi_prevent(sc_link, PR_ALLOW, SCSI_SILENT);
sc_link->flags &= ~SDEV_OPEN;
return ENXIO;
}
return 0;
}
static int
worm_close(dev_t dev, int flag, int fmt, struct proc *p,
struct scsi_link *sc_link)
{
scsi_stop_unit(sc_link, 0, SCSI_SILENT);
scsi_prevent(sc_link, PR_ALLOW, SCSI_SILENT);
sc_link->flags &= ~SDEV_OPEN;
return 0;
}
static worm_devsw_installed = 0;
static void
worm_drvinit(void *unused)
{
dev_t dev;
if( ! worm_devsw_installed ) {
dev = makedev(CDEV_MAJOR,0);
cdevsw_add(&dev,&worm_cdevsw,NULL);
worm_devsw_installed = 1;
}
}
SYSINIT(wormdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,worm_drvinit,NULL)