freebsd-src/sys/scsi/pt.c
Justin T. Gibbs a34bad999b Set SCSI_NOSLEEP only when we really need to. This requires an additional
flags parameter to all xxstart routines so that the correct information can
be passed down into the device specific routines.  This is needed to ensure
that ccb/scb allocation routines don't hang.

Submitted by: John Dyson
1995-04-23 22:07:56 +00:00

255 lines
6.6 KiB
C

/*
* pt: Processor Type 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: pt.c,v 1.2 1995/04/14 15:10:28 dufault Exp $
*/
/*
* XXX dufault@hda.com: 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
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <scsi/scsi_all.h>
#include <scsi/scsiconf.h>
struct scsi_data {
struct buf *buf_queue; /* the queue of pending IO operations */
};
void ptstart(u_int32 unit, u_int32 flags);
void pt_strategy(struct buf *bp, struct scsi_link *sc_link);
int pt_sense(struct scsi_xfer *scsi_xfer);
SCSI_DEVICE_ENTRIES(pt)
struct scsi_device pt_switch =
{
pt_sense,
ptstart, /* we have a queue, and this is how we service it */
NULL,
NULL,
"pt",
0,
{0, 0},
SDEV_ONCE_ONLY, /* Only one open allowed */
0,
"Processor",
ptopen,
sizeof(struct scsi_data),
T_PROCESSOR,
0,
0,
0,
0,
0,
pt_strategy,
};
/*
* ptstart 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 (ptstrategy)
*
* 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.
* ptstart() is called at splbio
*/
void
ptstart(unit, flags)
u_int32 unit;
u_int32 flags;
{
struct scsi_link *sc_link = SCSI_LINK(&pt_switch, unit);
struct scsi_data *pt = sc_link->sd;
register struct buf *bp = 0;
struct
{
#define PROCESSOR_SEND 0x0A
#define PROCESSOR_RECEIVE 0x08
u_char op_code;
u_char byte2;
u_char len[3];
u_char control;
} cmd;
SC_DEBUG(sc_link, SDEV_DB2, ("ptstart "));
/*
* 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((caddr_t)sc_link);
return;
}
if ((bp = pt->buf_queue) == NULL) {
return; /* no work to bother with */
}
pt->buf_queue = bp->b_actf;
/*
* Fill out the scsi command
*/
bzero(&cmd, sizeof(cmd));
if ((bp->b_flags & B_READ) == B_WRITE) {
cmd.op_code = PROCESSOR_SEND;
flags |= SCSI_DATA_OUT;
} else {
cmd.op_code = PROCESSOR_RECEIVE;
flags |= SCSI_DATA_IN;
}
scsi_uto3b(bp->b_bcount, cmd.len);
/*
* 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,
10000,
bp,
flags) == SUCCESSFULLY_QUEUED) {
} else {
printf("pt%ld: oops not queued\n", unit);
bp->b_flags |= B_ERROR;
bp->b_error = EIO;
biodone(bp);
}
} /* go back and see if we can cram more work in.. */
}
void
pt_strategy(struct buf *bp, struct scsi_link *sc_link)
{
struct buf **dp;
unsigned char unit;
u_int32 opri;
struct scsi_data *pt;
unit = STUNIT((bp->b_dev));
pt = sc_link->sd;
opri = splbio();
/*
* Use a bounce buffer if necessary
*/
#ifdef BOUNCE_BUFFERS
if (sc_link->flags & SDEV_BOUNCE)
vm_bounce_alloc(bp);
#endif
/*
* Place it in the queue of activities for this tape
* at the end (a bit silly because we only have one user..
* (but it could fork() ))
*/
dp = &(pt->buf_queue);
while (*dp) {
dp = &((*dp)->b_actf);
}
*dp = bp;
bp->b_actf = NULL;
/*
* Tell the device to get going on the transfer if it's
* not doing anything, otherwise just wait for completion
* (All a bit silly if we're only allowing 1 open but..)
*/
ptstart(unit, 0);
splx(opri);
return;
}
/*
* sense handler: Called to determine what to do when the
* device returns a CHECK CONDITION.
*
* For the processor type devices we try to handle the "info" field.
*/
int pt_sense(struct scsi_xfer *xs)
{
struct scsi_sense_data *sense = &(xs->sense);
struct buf *bp;
long resid;
if ((sense->error_code & SSD_ERRCODE_VALID) == 0 ||
(sense->ext.extended.flags & SSD_ILI) == 0) {
return SCSIRET_CONTINUE; /* let the default handler handle it */
}
resid = ntohl(*((int32 *) sense->ext.extended.info));
bp = xs->bp;
if (resid < 0) {
/* It synthesized data in order to fill our request.
* Move resid back to cover this.
*/
xs->resid = -resid;
xs->flags |= SCSI_RESID_VALID;
return 0;
}
else {
/* It wanted to send more data. We can't really do anything
* about this.
*/
return SCSIRET_CONTINUE;
}
}