* Copyright (c) 1995 David Jones, Gordon W. Ross

/* $NetBSD: ncr5380sbc.c,v 1.74 2024/10/29 15:58:14 nat Exp $ */

/*
* Copyright (c) 1995 David Jones, Gordon W. Ross
* Copyright (c) 1994 Jarle Greipsland
* 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. The name of the authors may not be used to endorse or promote products
* derived from this software without specific prior written permission.
* 4. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by
* David Jones and Gordon Ross
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``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 AUTHORS 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.
*/

/*
* This is a machine-independent driver for the NCR5380
* SCSI Bus Controller (SBC), also known as the Am5380.
*
* This code should work with any memory-mapped 5380,
* and can be shared by multiple adapters that address
* the 5380 with different register offset spacings.
* (This can happen on the atari, for example.)
* For porting/design info. see: ncr5380.doc
*
* Credits, history:
*
* David Jones is the author of most of the code that now
* appears in this file, and was the architect of the
* current overall structure (MI/MD code separation, etc.)
*
* Gordon Ross integrated the message phase code, added lots of
* comments about what happens when and why (re. SCSI spec.),
* debugged some reentrance problems, and added several new
* "hooks" needed for the Sun3 "si" adapters.
*
* The message in/out code was taken nearly verbatim from
* the aic6360 driver by Jarle Greipsland.
*
* Several other NCR5380 drivers were used for reference
* while developing this driver, including work by:
* The Alice Group (mac68k port) namely:
* Allen K. Briggs, Chris P. Caputo, Michael L. Finch,
* Bradley A. Grantham, and Lawrence A. Kesteloot
* Michael L. Hitch (amiga drivers: sci.c)
* Leo Weppelman (atari driver: ncr5380.c)
* There are others too. Thanks, everyone.
*
* Transliteration to bus_space() performed 9/17/98 by
* John Ruschmeyer ([email protected]) for i386 'nca' driver.
* Thank you all.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ncr5380sbc.c,v 1.74 2024/10/29 15:58:14 nat Exp $");

#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/errno.h>
#include <sys/device.h>
#include <sys/buf.h>
#include <sys/proc.h>

#include <dev/scsipi/scsi_all.h>
#include <dev/scsipi/scsipi_all.h>
#include <dev/scsipi/scsipi_debug.h>
#include <dev/scsipi/scsi_message.h>
#include <dev/scsipi/scsiconf.h>

#ifdef DDB
#include <ddb/db_output.h>
#endif

#include <dev/ic/ncr5380reg.h>
#include <dev/ic/ncr5380var.h>
#include <dev/ic/ncr53c400reg.h>

static void ncr5380_reset_scsibus(struct ncr5380_softc *);
static void ncr5380_sched(struct ncr5380_softc *);
static void ncr5380_done(struct ncr5380_softc *);

static int ncr5380_select(struct ncr5380_softc *, struct sci_req *);
static void ncr5380_reselect(struct ncr5380_softc *);

static int ncr5380_msg_in(struct ncr5380_softc *);
static int ncr5380_msg_out(struct ncr5380_softc *);
static int ncr5380_data_xfer(struct ncr5380_softc *, int);
static int ncr5380_command(struct ncr5380_softc *);
static int ncr5380_status(struct ncr5380_softc *);
static void ncr5380_machine(struct ncr5380_softc *);

void ncr5380_abort(struct ncr5380_softc *);
void ncr5380_cmd_timeout(void *);
/*
* Action flags returned by the info_transfer functions:
* (These determine what happens next.)
*/
#define ACT_CONTINUE 0x00 /* No flags: expect another phase */
#define ACT_DISCONNECT 0x01 /* Target is disconnecting */
#define ACT_CMD_DONE 0x02 /* Need to call scsipi_done() */
#define ACT_RESET_BUS 0x04 /* Need bus reset (cmd timeout) */
#define ACT_WAIT_DMA 0x10 /* Wait for DMA to complete */

/*****************************************************************
* Debugging stuff
*****************************************************************/

#ifndef DDB
/* This is used only in recoverable places. */
#ifndef Debugger
#define Debugger() printf("Debug: ncr5380.c:%d\n", __LINE__)
#endif
#endif

#ifdef NCR5380_DEBUG
struct ncr5380_softc *ncr5380_debug_sc;

#define NCR_DBG_BREAK 1
#define NCR_DBG_CMDS 2
int ncr5380_debug = 0;
#define NCR_BREAK() \
do { if (ncr5380_debug & NCR_DBG_BREAK) Debugger(); } while (0)
static void ncr5380_show_scsi_cmd(struct scsipi_xfer *);
#ifdef DDB
void ncr5380_clear_trace(void);
void ncr5380_show_trace(void);
void ncr5380_show_req(struct sci_req *);
void ncr5380_show_state(void);
#endif /* DDB */
#else /* NCR5380_DEBUG */

#define NCR_BREAK() /* nada */
#define ncr5380_show_scsi_cmd(xs) /* nada */

#endif /* NCR5380_DEBUG */

static const char *
phase_names[8] = {
"DATA_OUT",
"DATA_IN",
"COMMAND",
"STATUS",
"UNSPEC1",
"UNSPEC2",
"MSG_OUT",
"MSG_IN",
};

/*****************************************************************
* Actual chip control
*****************************************************************/

/*
* XXX: These timeouts might need to be tuned...
*/

/* This one is used when waiting for a phase change. (X100uS.) */
int ncr5380_wait_phase_timo = 1000 * 10 * 300; /* 5 min. */

/* These are used in the following inline functions. */
int ncr5380_wait_req_timo = 1000 * 50; /* X2 = 100 mS. */
int ncr5380_wait_nrq_timo = 1000 * 25; /* X2 = 50 mS. */

static inline int ncr5380_wait_req(struct ncr5380_softc *);
static inline int ncr5380_wait_not_req(struct ncr5380_softc *);
static inline void ncr_sched_msgout(struct ncr5380_softc *, int);

/* Return zero on success. */
static inline int
ncr5380_wait_req(struct ncr5380_softc *sc)
{
int timo = ncr5380_wait_req_timo;

for (;;) {
if (NCR5380_READ(sc, sci_bus_csr) & SCI_BUS_REQ) {
timo = 0; /* return 0 */
break;
}
if (--timo < 0)
break; /* return -1 */
delay(2);
}
return timo;
}

/* Return zero on success. */
static inline int
ncr5380_wait_not_req(struct ncr5380_softc *sc)
{
int timo = ncr5380_wait_nrq_timo;

for (;;) {
if ((NCR5380_READ(sc, sci_bus_csr) & SCI_BUS_REQ) == 0) {
timo = 0; /* return 0 */
break;
}
if (--timo < 0)
break; /* return -1 */
delay(2);
}
return timo;
}

/* Ask the target for a MSG_OUT phase. */
static inline void
ncr_sched_msgout(struct ncr5380_softc *sc, int msg_code)
{

/* First time, raise ATN line. */
if (sc->sc_msgpriq == 0) {
uint8_t icmd;
icmd = NCR5380_READ(sc, sci_icmd) & SCI_ICMD_RMASK;
NCR5380_WRITE(sc, sci_icmd, (icmd | SCI_ICMD_ATN));
delay(2);
}
sc->sc_msgpriq |= msg_code;
}

int
ncr5380_pio_out(struct ncr5380_softc *sc, int phase, int count, uint8_t *data)
{
uint8_t icmd;
int resid;
int error;

icmd = NCR5380_READ(sc, sci_icmd) & SCI_ICMD_RMASK;

icmd |= SCI_ICMD_DATA;
NCR5380_WRITE(sc, sci_icmd, icmd);

resid = count;
while (resid > 0) {
if (!SCI_BUSY(sc)) {
NCR_TRACE("pio_out: lost BSY, resid=%d\n", resid);
break;
}
if (ncr5380_wait_req(sc)) {
NCR_TRACE("pio_out: no REQ, resid=%d\n", resid);
break;
}
if (SCI_BUS_PHASE(NCR5380_READ(sc, sci_bus_csr)) != phase)
break;

/* Put the data on the bus. */
if (data)
NCR5380_WRITE(sc, sci_odata, *data++);
else
NCR5380_WRITE(sc, sci_odata, 0);

/* Tell the target it's there. */
icmd |= SCI_ICMD_ACK;
NCR5380_WRITE(sc, sci_icmd, icmd);

/* Wait for target to get it. */
error = ncr5380_wait_not_req(sc);

/* OK, it's got it (or we gave up waiting). */
icmd &= ~SCI_ICMD_ACK;
NCR5380_WRITE(sc, sci_icmd, icmd);

if (error) {
NCR_TRACE("pio_out: stuck REQ, resid=%d\n", resid);
break;
}

--resid;
}

/* Stop driving the data bus. */
icmd &= ~SCI_ICMD_DATA;
NCR5380_WRITE(sc, sci_icmd, icmd);

return count - resid;
}

int
ncr5380_pio_in(struct ncr5380_softc *sc, int phase, int count, uint8_t *data)
{
uint8_t icmd;
int resid;
int error;

icmd = NCR5380_READ(sc, sci_icmd) & SCI_ICMD_RMASK;

resid = count;
while (resid > 0) {
if (!SCI_BUSY(sc)) {
NCR_TRACE("pio_in: lost BSY, resid=%d\n", resid);
break;
}
if (ncr5380_wait_req(sc)) {
NCR_TRACE("pio_in: no REQ, resid=%d\n", resid);
break;
}
/* A phase change is not valid until AFTER REQ rises! */
if (SCI_BUS_PHASE(NCR5380_READ(sc, sci_bus_csr)) != phase)
break;

/* Read the data bus. */
if (data)
*data++ = NCR5380_READ(sc, sci_data);
else
(void) NCR5380_READ(sc, sci_data);

/* Tell target we got it. */
icmd |= SCI_ICMD_ACK;
NCR5380_WRITE(sc, sci_icmd, icmd);

/* Wait for target to drop REQ... */
error = ncr5380_wait_not_req(sc);

/* OK, we can drop ACK. */
icmd &= ~SCI_ICMD_ACK;
NCR5380_WRITE(sc, sci_icmd, icmd);

if (error) {
NCR_TRACE("pio_in: stuck REQ, resid=%d\n", resid);
break;
}

--resid;
}

return count - resid;
}

void
ncr5380_init(struct ncr5380_softc *sc)
{
int i, j;

#ifdef NCR5380_DEBUG
ncr5380_debug_sc = sc;
#endif

for (i = 0; i < SCI_OPENINGS; i++)
sc->sc_ring[i].sr_xs = NULL;
for (i = 0; i < 8; i++)
for (j = 0; j < 8; j++)
sc->sc_matrix[i][j] = NULL;

sc->sc_prevphase = PHASE_INVALID;
sc->sc_state = NCR_IDLE;

#ifdef NCR5380_USE_BUS_SPACE
if (sc->sc_rev == NCR_VARIANT_NCR53C400)
bus_space_write_1(sc->sc_regt, sc->sc_regh, C400_CSR,
C400_CSR_5380_ENABLE);
#endif

NCR5380_WRITE(sc, sci_tcmd, PHASE_INVALID);
NCR5380_WRITE(sc, sci_icmd, 0);
NCR5380_WRITE(sc, sci_mode, 0);
NCR5380_WRITE(sc, sci_sel_enb, 0);
SCI_CLR_INTR(sc);

/* XXX: Enable reselect interrupts... */
NCR5380_WRITE(sc, sci_sel_enb, 0x80);

/* Another hack (Er.. hook!) for the sun3 si: */
if (sc->sc_intr_on) {
NCR_TRACE("init: intr ON\n", 0);
sc->sc_intr_on(sc);
}
}

static void
ncr5380_reset_scsibus(struct ncr5380_softc *sc)
{
struct sci_req *sr;

NCR_TRACE("reset_scsibus, cur=0x%x\n",
(long) sc->sc_current);

NCR5380_WRITE(sc, sci_icmd, SCI_ICMD_RST);
delay(500);
NCR5380_WRITE(sc, sci_icmd, 0);

NCR5380_WRITE(sc, sci_mode, 0);
NCR5380_WRITE(sc, sci_tcmd, PHASE_INVALID);

SCI_CLR_INTR(sc);
/* XXX - Need long delay here! */
delay(100000);

/* XXX - Need to cancel disconnected requests. */
sr = sc->sc_current;
if (sr && (sc->sc_state & NCR_ABORTING) == 0)
ncr5380_abort(sc);
}

/*
* Interrupt handler for the SCSI Bus Controller (SBC)
* This may also called for a DMA timeout (at splbio).
*/
int
ncr5380_intr(void *arg)
{
struct ncr5380_softc *sc = arg;
int claimed = 0;

/*
* Do not touch SBC regs here unless sc_current == NULL
* or it will complain about "register conflict" errors.
* Instead, just let ncr5380_machine() deal with it.
*/
NCR_TRACE("intr: top, state=%d\n", sc->sc_state);

if (sc->sc_state == NCR_IDLE) {
/*
* Might be reselect. ncr5380_reselect() will check,
* and set up the connection if so. This will verify
* that sc_current == NULL at the beginning...
*/

/* Another hack (Er.. hook!) for the sun3 si: */
if (sc->sc_intr_off) {
NCR_TRACE("intr: for reselect, intr off\n", 0);
sc->sc_intr_off(sc);
}

ncr5380_reselect(sc);
}

/*
* The remaining documented interrupt causes are phase mismatch and
* disconnect. In addition, the sunsi controller may produce a state
* where SCI_CSR_DONE is false, yet DMA is complete.
*
* The procedure in all these cases is to let ncr5380_machine()
* figure out what to do next.
*/
if (sc->sc_state & NCR_WORKING) {
NCR_TRACE("intr: call machine, cur=0x%x\n",
(long) sc->sc_current);
/* This will usually free-up the nexus. */
ncr5380_machine(sc);
NCR_TRACE("intr: machine done, cur=0x%x\n",
(long) sc->sc_current);
claimed = 1;
}

/* Maybe we can run some commands now... */
if (sc->sc_state == NCR_IDLE) {
NCR_TRACE("intr: call sched, cur=0x%x\n",
(long) sc->sc_current);
ncr5380_sched(sc);
NCR_TRACE("intr: sched done, cur=0x%x\n",
(long) sc->sc_current);
}

return claimed;
}

/*
* Abort the current command (i.e. due to timeout)
*/
void
ncr5380_abort(struct ncr5380_softc *sc)
{

/*
* Finish it now. If DMA is in progress, we
* can not call ncr_sched_msgout() because
* that hits the SBC (avoid DMA conflict).
*/

/* Another hack (Er.. hook!) for the sun3 si: */
if (sc->sc_intr_off) {
NCR_TRACE("abort: intr off\n", 0);
sc->sc_intr_off(sc);
}

sc->sc_state |= NCR_ABORTING;
if ((sc->sc_state & NCR_DOINGDMA) == 0) {
ncr_sched_msgout(sc, SEND_ABORT);
}
NCR_TRACE("abort: call machine, cur=0x%x\n",
(long) sc->sc_current);
ncr5380_machine(sc);
NCR_TRACE("abort: machine done, cur=0x%x\n",
(long) sc->sc_current);

/* Another hack (Er.. hook!) for the sun3 si: */
if (sc->sc_intr_on) {
NCR_TRACE("abort: intr ON\n", 0);
sc->sc_intr_on(sc);
}
}

/*
* Timeout handler, scheduled for each SCSI command.
*/
void
ncr5380_cmd_timeout(void *arg)
{
struct sci_req *sr = arg;
struct scsipi_xfer *xs;
struct scsipi_periph *periph;
struct ncr5380_softc *sc;
int s;

s = splbio();

/* Get all our variables... */
xs = sr->sr_xs;
if (xs == NULL) {
printf("ncr5380_cmd_timeout: no scsipi_xfer\n");
goto out;
}
periph = xs->xs_periph;
sc = device_private(periph->periph_channel->chan_adapter->adapt_dev);

printf("%s: cmd timeout, targ=%d, lun=%d\n",
device_xname(sc->sc_dev),
sr->sr_target, sr->sr_lun);

/*
* Mark the overdue job as failed, and arrange for
* ncr5380_machine to terminate it. If the victim
* is the current job, call ncr5380_machine() now.
* Otherwise arrange for ncr5380_sched() to do it.
*/
sr->sr_flags |= SR_OVERDUE;
if (sc->sc_current == sr) {
NCR_TRACE("cmd_tmo: call abort, sr=0x%x\n", (long) sr);
ncr5380_abort(sc);
} else {
/*
* The driver may be idle, or busy with another job.
* Arrange for ncr5380_sched() to do the deed.
*/
NCR_TRACE("cmd_tmo: clear matrix, t/l=0x%02x\n",
(sr->sr_target << 4) | sr->sr_lun);
sc->sc_matrix[sr->sr_target][sr->sr_lun] = NULL;
}

/*
* We may have aborted the current job, or may have
* already been idle. In either case, we should now
* be idle, so try to start another job.
*/
if (sc->sc_state == NCR_IDLE) {
NCR_TRACE("cmd_tmo: call sched, cur=0x%lx\n",
(long)sc->sc_current);
ncr5380_sched(sc);
NCR_TRACE("cmd_tmo: sched done, cur=0x%lx\n",
(long)sc->sc_current);
}

out:
splx(s);
}

/*****************************************************************
* Interface to higher level
*****************************************************************/

/*
* Enter a new SCSI command into the "issue" queue, and
* if there is work to do, start it going.
*
* WARNING: This can be called recursively!
* (see comment in ncr5380_done)
*/

void
ncr5380_scsipi_request(struct scsipi_channel *chan, scsipi_adapter_req_t req,
void *arg)
{
struct scsipi_xfer *xs;
struct scsipi_periph *periph;
struct ncr5380_softc *sc;
struct sci_req *sr;
int s, i, flags;

sc = device_private(chan->chan_adapter->adapt_dev);

switch (req) {
case ADAPTER_REQ_RUN_XFER:
xs = arg;
periph = xs->xs_periph;
flags = xs->xs_control;

if (flags & XS_CTL_DATA_UIO)
panic("%s: scsi data uio requested", __func__);

s = splbio();

if (flags & XS_CTL_POLL) {
/* Terminate any current command. */
sr = sc->sc_current;
if (sr) {
#ifdef NCR5380_DEBUG
printf("%s: polled request aborting %d/%d\n",
device_xname(sc->sc_dev),
sr->sr_target, sr->sr_lun);
#endif
ncr5380_abort(sc);
}
if (sc->sc_state != NCR_IDLE) {
panic("%s: polled request, abort failed",
__func__);
}
}

/*
* Find lowest empty slot in ring buffer.
* XXX: What about "fairness" and cmd order?
*/
for (i = 0; i < SCI_OPENINGS; i++)
if (sc->sc_ring[i].sr_xs == NULL)
goto new;

/*
* This should never happen as we track the resources
* in the mid-layer.
*/
scsipi_printaddr(periph);
printf("unable to allocate ring slot\n");
panic("%s", __func__);

new:
/* Create queue entry */
sr = &sc->sc_ring[i];
sr->sr_xs = xs;
sr->sr_target = periph->periph_target;
sr->sr_lun = periph->periph_lun;
sr->sr_dma_hand = NULL;
sr->sr_dataptr = xs->data;
sr->sr_datalen = xs->datalen;
sr->sr_flags = (flags & XS_CTL_POLL) ? SR_IMMED : 0;
if (xs->xs_control & XS_CTL_REQSENSE)
sr->sr_flags |= SR_IMMED; /* no disconnect */
sr->sr_status = -1; /* no value */
sc->sc_ncmds++;

NCR_TRACE("scsipi_cmd: new sr=0x0\n", (long)sr);

if (flags & XS_CTL_POLL) {
/* Force this new command to be next. */
sc->sc_rr = i;
}

/*
* If we were idle, run some commands...
*/
if (sc->sc_state == NCR_IDLE) {
NCR_TRACE("scsipi_cmd: call sched, cur=0x%x\n",
(long) sc->sc_current);
ncr5380_sched(sc);
NCR_TRACE("scsipi_cmd: sched done, cur=0x%x\n",
(long) sc->sc_current);
}

if (flags & XS_CTL_POLL) {
/* Make sure ncr5380_sched() finished it. */
if ((xs->xs_status & XS_STS_DONE) == 0)
panic("%s: poll didn't finish", __func__);
}
splx(s);
return;

case ADAPTER_REQ_GROW_RESOURCES:
/* XXX Not supported. */
return;

case ADAPTER_REQ_SET_XFER_MODE:
{
/*
* We don't support Sync, Wide, or Tagged Queueing.
* Just callback now, to report this.
*/
struct scsipi_xfer_mode *xm = arg;

xm->xm_mode = 0;
xm->xm_period = 0;
xm->xm_offset = 0;
scsipi_async_event(chan, ASYNC_EVENT_XFER_MODE, xm);
return;
}
}
}

/*
* POST PROCESSING OF SCSI_CMD (usually current)
* Called by ncr5380_sched(), ncr5380_machine()
*/
static void
ncr5380_done(struct ncr5380_softc *sc)
{
struct sci_req *sr;
struct scsipi_xfer *xs;

#ifdef DIAGNOSTIC
if (sc->sc_state == NCR_IDLE)
panic("%s: state=idle", __func__);
if (sc->sc_current == NULL)
panic("%s: current=0", __func__);
#endif

sr = sc->sc_current;
xs = sr->sr_xs;

NCR_TRACE("done: top, cur=0x%x\n", (long) sc->sc_current);

/*
* Clean up DMA resources for this command.
*/
if (sr->sr_dma_hand) {
NCR_TRACE("done: dma_free, dh=0x%x\n",
(long) sr->sr_dma_hand);
(*sc->sc_dma_free)(sc);
}
#ifdef DIAGNOSTIC
if (sr->sr_dma_hand)
panic("%s: DMA free did not", __func__);
#endif

if (sc->sc_state & NCR_ABORTING) {
NCR_TRACE("done: aborting, error=%d\n", xs->error);
if (xs->error == XS_NOERROR)
xs->error = XS_TIMEOUT;
}

NCR_TRACE("done: check error=%d\n", (long) xs->error);

/* If error is already set, ignore sr_status value. */
if (xs->error != XS_NOERROR)
goto finish;

NCR_TRACE("done: check status=%d\n", sr->sr_status);

xs->status = sr->sr_status;
switch (sr->sr_status) {
case SCSI_OK: /* 0 */
xs->error = XS_NOERROR;
break;

case SCSI_CHECK:
case SCSI_BUSY:
xs->error = XS_BUSY;
break;

case -1:
/* This is our "impossible" initial value. */
/* fallthrough */
default:
printf("%s: target %d, bad status=%d\n",
device_xname(sc->sc_dev), sr->sr_target, sr->sr_status);
xs->error = XS_DRIVER_STUFFUP;
break;
}

finish:

NCR_TRACE("done: finish, error=%d\n", xs->error);

/*
* Dequeue the finished command, but don't clear sc_state until
* after the call to scsipi_done(), because that may call back to
* ncr5380_scsi_cmd() - unwanted recursion!
*
* Keeping sc->sc_state != idle terminates the recursion.
*/
#ifdef DIAGNOSTIC
if ((sc->sc_state & NCR_WORKING) == 0)
panic("%s: bad state", __func__);
#endif

/* Clear our pointers to the request. */
sc->sc_current = NULL;
sc->sc_matrix[sr->sr_target][sr->sr_lun] = NULL;
callout_stop(&sr->sr_xs->xs_callout);

/* Make the request free. */
sr->sr_xs = NULL;
sc->sc_ncmds--;

const bool aborting = sc->sc_state & NCR_ABORTING;
if (aborting)
scsipi_channel_freeze(&sc->sc_channel, 1);

/* Tell common SCSI code it is done. */
scsipi_done(xs);

sc->sc_state = NCR_IDLE;
/* Now ncr5380_sched() may be called again. */

if (aborting)
scsipi_channel_thaw(&sc->sc_channel, 1);
}

/*
* Schedule a SCSI operation. This routine should return
* only after it achieves one of the following conditions:
* Busy (sc->sc_state != NCR_IDLE)
* No more work can be started.
*/
static void
ncr5380_sched(struct ncr5380_softc *sc)
{
struct sci_req *sr;
struct scsipi_xfer *xs;
int target = 0, lun = 0;
int error, i;

/* Another hack (Er.. hook!) for the sun3 si: */
if (sc->sc_intr_off) {
NCR_TRACE("sched: top, intr off\n", 0);
sc->sc_intr_off(sc);
}

next_job:
/*
* Grab the next job from queue. Must be idle.
*/
#ifdef DIAGNOSTIC
if (sc->sc_state != NCR_IDLE)
panic("%s: not idle", __func__);
if (sc->sc_current)
panic("%s: current set", __func__);
#endif

/*
* Always start the search where we last looked.
* The REQUEST_SENSE logic depends on this to
* choose the same job as was last picked, so it
* can just clear sc_current and reschedule.
* (Avoids loss of "contingent allegiance".)
*/
i = sc->sc_rr;
sr = NULL;
do {
if (sc->sc_ring[i].sr_xs) {
target = sc->sc_ring[i].sr_target;
lun = sc->sc_ring[i].sr_lun;
if (sc->sc_matrix[target][lun] == NULL) {
/*
* Do not mark the target/LUN busy yet,
* because reselect may cause some other
* job to become the current one, so we
* might not actually start this job.
* Instead, set sc_matrix later on.
*/
sc->sc_rr = i;
sr = &sc->sc_ring[i];
break;
}
}
i++;
if (i == SCI_OPENINGS)
i = 0;
} while (i != sc->sc_rr);

if (sr == NULL) {
NCR_TRACE("sched: no work, cur=0x%x\n",
(long) sc->sc_current);

/* Another hack (Er.. hook!) for the sun3 si: */
if (sc->sc_intr_on) {
NCR_TRACE("sched: ret, intr ON\n", 0);
sc->sc_intr_on(sc);
}

return; /* No more work to do. */
}

NCR_TRACE("sched: select for t/l=0x%02x\n",
(sr->sr_target << 4) | sr->sr_lun);

sc->sc_state = NCR_WORKING;
error = ncr5380_select(sc, sr);
if (sc->sc_current) {
/* Lost the race! reselected out from under us! */
/* Work with the reselected job. */
if (sr->sr_flags & SR_IMMED) {
printf("%s: reselected while polling (abort)\n",
device_xname(sc->sc_dev));
/* Abort the reselected job. */
sc->sc_state |= NCR_ABORTING;
sc->sc_msgpriq |= SEND_ABORT;
}
sr = sc->sc_current;
xs = sr->sr_xs;
NCR_TRACE("sched: reselect, new sr=0x%x\n", (long)sr);
goto have_nexus;
}

/* Normal selection result. Target/LUN is now busy. */
sc->sc_matrix[target][lun] = sr;
sc->sc_current = sr; /* connected */
xs = sr->sr_xs;

/*
* Initialize pointers, etc. for this job
*/
sc->sc_dataptr = sr->sr_dataptr;
sc->sc_datalen = sr->sr_datalen;
sc->sc_prevphase = PHASE_INVALID;
sc->sc_msgpriq = SEND_IDENTIFY;
sc->sc_msgoutq = 0;
sc->sc_msgout = 0;

NCR_TRACE("sched: select rv=%d\n", error);

switch (error) {
case XS_NOERROR:
break;

case XS_BUSY:
/* XXX - Reset and try again. */
printf("%s: select found SCSI bus busy, resetting...\n",
device_xname(sc->sc_dev));
ncr5380_reset_scsibus(sc);
/* fallthrough */
case XS_SELTIMEOUT:
default:
xs->error = error; /* from select */
NCR_TRACE("sched: call done, sr=0x%x\n", (long)sr);
ncr5380_done(sc);

/* Paranoia: clear everything. */
sc->sc_dataptr = NULL;
sc->sc_datalen = 0;
sc->sc_prevphase = PHASE_INVALID;
sc->sc_msgpriq = 0;
sc->sc_msgoutq = 0;
sc->sc_msgout = 0;

goto next_job;
}

/*
* Selection was successful. Normally, this means
* we are starting a new command. However, this
* might be the termination of an overdue job.
*/
if (sr->sr_flags & SR_OVERDUE) {
NCR_TRACE("sched: overdue, sr=0x%x\n", (long)sr);
sc->sc_state |= NCR_ABORTING;
sc->sc_msgpriq |= SEND_ABORT;
goto have_nexus;
}

/*
* OK, we are starting a new command.
* Initialize and allocate resources for the new command.
* Device reset is special (only uses MSG_OUT phase).
* Normal commands start in MSG_OUT phase where we will
* send and IDENDIFY message, and then expect CMD phase.
*/
#ifdef NCR5380_DEBUG
if (ncr5380_debug & NCR_DBG_CMDS) {
printf("ncr5380_sched: begin, target=%d, LUN=%d\n",
xs->xs_periph->periph_target, xs->xs_periph->periph_lun);
ncr5380_show_scsi_cmd(xs);
}
#endif
if (xs->xs_control & XS_CTL_RESET) {
NCR_TRACE("sched: cmd=reset, sr=0x%x\n", (long)sr);
/* Not an error, so do not set NCR_ABORTING */
sc->sc_msgpriq |= SEND_DEV_RESET;
goto have_nexus;
}

#ifdef DIAGNOSTIC
if ((xs->xs_control & (XS_CTL_DATA_IN | XS_CTL_DATA_OUT)) == 0) {
if (sc->sc_dataptr) {
printf("%s: ptr but no data in/out flags?\n",
device_xname(sc->sc_dev));
NCR_BREAK();
sc->sc_dataptr = NULL;
}
}
#endif

/* Allocate DMA space (maybe) */
if (sc->sc_dataptr && sc->sc_dma_alloc &&
(sc->sc_datalen >= sc->sc_min_dma_len))
{
NCR_TRACE("sched: dma_alloc, len=%d\n", sc->sc_datalen);
(*sc->sc_dma_alloc)(sc);
}

/*
* Initialization hook called just after select,
* at the beginning of COMMAND phase.
* (but AFTER the DMA allocation is done)
*
* The evil Sun "si" adapter (OBIO variant) needs some
* setup done to the DMA engine BEFORE the target puts
* the SCSI bus into any DATA phase.
*/
if (sr->sr_dma_hand && sc->sc_dma_setup) {
NCR_TRACE("sched: dma_setup, dh=0x%x\n",
(long) sr->sr_dma_hand);
sc->sc_dma_setup(sc);
}

/*
* Schedule a timeout for the job we are starting.
*/
if ((sr->sr_flags & SR_IMMED) == 0) {
i = mstohz(xs->timeout);
NCR_TRACE("sched: set timeout=%d\n", i);
callout_reset(&sr->sr_xs->xs_callout, i,
ncr5380_cmd_timeout, sr);
}

have_nexus:
NCR_TRACE("sched: call machine, cur=0x%x\n",
(long) sc->sc_current);
ncr5380_machine(sc);
NCR_TRACE("sched: machine done, cur=0x%x\n",
(long) sc->sc_current);

/*
* What state did ncr5380_machine() leave us in?
* Hopefully it sometimes completes a job...
*/
if (sc->sc_state == NCR_IDLE)
goto next_job;

return; /* Have work in progress. */
}

/*
* Reselect handler: checks for reselection, and if we are being
* reselected, it sets up sc->sc_current.
*
* We are reselected when:
* SEL is TRUE
* IO is TRUE
* BSY is FALSE
*/
void
ncr5380_reselect(struct ncr5380_softc *sc)
{
struct sci_req *sr;
int target, lun, phase, timo;
int target_mask = 0; /* XXX gcc (on ns32k) */
uint8_t bus, data, icmd, mode, msg;

#ifdef DIAGNOSTIC
/*
* Note: sc_state will be "idle" when ncr5380_intr()
* calls, or "working" when ncr5380_select() calls.
* (So don't test that in this DIAGNOSTIC)
*/
if (sc->sc_current)
panic("%s: current set", __func__);
#endif

/*
* First, check the select line.
* (That has to be set first.)
*/
bus = NCR5380_READ(sc, sci_bus_csr);
if ((bus & SCI_BUS_SEL) == 0) {
/* Not a selection or reselection. */
return;
}

/*
* The target will assert BSY first (for bus arbitration),
* then raise SEL, and finally drop BSY. Only then is the
* data bus required to have valid selection ID bits set.
* Wait for: SEL==1, BSY==0 before reading the data bus.
* While this theoretically can happen, we are apparently
* never fast enough to get here before BSY drops.
*/
timo = ncr5380_wait_nrq_timo;
for (;;) {
if ((bus & SCI_BUS_BSY) == 0)
break;
/* Probably never get here... */
if (--timo <= 0) {
printf("%s: reselect, BSY stuck, bus=0x%x\n",
device_xname(sc->sc_dev), bus);
/* Not much we can do. Reset the bus. */
ncr5380_reset_scsibus(sc);
return;
}
delay(2);
bus = NCR5380_READ(sc, sci_bus_csr);
/* If SEL went away, forget it. */
if ((bus & SCI_BUS_SEL) == 0)
return;
/* Still have SEL, check BSY. */
}
NCR_TRACE("reselect, valid data after %d loops\n",
ncr5380_wait_nrq_timo - timo);

/*
* Good. We have SEL=1 and BSY=0. Now wait for a
* "bus settle delay" before we sample the data bus
*/
delay(2);
data = NCR5380_READ(sc, sci_data) & 0xFF;
/* Parity check is implicit in data validation below. */

/*
* Is this a reselect (I/O == 1) or have we been
* selected as a target? (I/O == 0)
*/
if ((bus & SCI_BUS_IO) == 0) {
printf("%s: selected as target, data=0x%x\n",
device_xname(sc->sc_dev), data);
/* Not much we can do. Reset the bus. */
/* XXX: send some sort of message? */
ncr5380_reset_scsibus(sc);
return;
}

/*
* OK, this is a reselection.
*/
for (target = 0; target < 7; target++) {
target_mask = (1 << target);
if (data & target_mask)
break;
}
if ((data & 0x7F) != target_mask) {
/* No selecting ID? or >2 IDs on bus? */
printf("%s: bad reselect, data=0x%x\n",
device_xname(sc->sc_dev), data);
return;
}

NCR_TRACE("reselect: target=0x%x\n", target);

/* Raise BSY to acknowledge target reselection. */
NCR5380_WRITE(sc, sci_icmd, SCI_ICMD_BSY);

/* Wait for target to drop SEL. */
timo = ncr5380_wait_nrq_timo;
for (;;) {
bus = NCR5380_READ(sc, sci_bus_csr);
if ((bus & SCI_BUS_SEL) == 0)
break; /* success */
if (--timo <= 0) {
printf("%s: reselect, SEL stuck, bus=0x%x\n",
device_xname(sc->sc_dev), bus);
NCR_BREAK();
/* assume connected (fail later if not) */
break;
}
delay(2);
}

/* Now we drop BSY, and we are connected. */
NCR5380_WRITE(sc, sci_icmd, 0);
NCR5380_WRITE(sc, sci_sel_enb, 0);
SCI_CLR_INTR(sc);

/*
* At this point the target should send an IDENTIFY message,
* which will permit us to determine the reselecting LUN.
* If not, we assume LUN 0.
*/
lun = 0;
/* Wait for REQ before reading bus phase. */
if (ncr5380_wait_req(sc)) {
printf("%s: reselect, no REQ\n",
device_xname(sc->sc_dev));
/* Try to send an ABORT message. */
goto abort;
}
phase = SCI_BUS_PHASE(NCR5380_READ(sc, sci_bus_csr));
if (phase != PHASE_MSG_IN) {
printf("%s: reselect, phase=%d\n",
device_xname(sc->sc_dev), phase);
goto abort;
}

/* Ack. the change to PHASE_MSG_IN */
NCR5380_WRITE(sc, sci_tcmd, PHASE_MSG_IN);

/* Peek at the message byte without consuming it! */
msg = NCR5380_READ(sc, sci_data);
if ((msg & 0x80) == 0) {
printf("%s: reselect, not identify, msg=%d\n",
device_xname(sc->sc_dev), msg);
goto abort;
}
lun = msg & 7;

/* We now know target/LUN. Do we have the request? */
sr = sc->sc_matrix[target][lun];
if (sr) {
/* We now have a nexus. */
sc->sc_state |= NCR_WORKING;
sc->sc_current = sr;
NCR_TRACE("reselect: resume sr=0x%x\n", (long)sr);

/* Implicit restore pointers message */
sc->sc_dataptr = sr->sr_dataptr;
sc->sc_datalen = sr->sr_datalen;

sc->sc_prevphase = PHASE_INVALID;
sc->sc_msgpriq = 0;
sc->sc_msgoutq = 0;
sc->sc_msgout = 0;

/* XXX: Restore the normal mode register. */
/* If this target's bit is set, do NOT check parity. */
if (sc->sc_parity_disable & target_mask)
mode = SCI_MODE_MONBSY;
else
mode = SCI_MODE_MONBSY | SCI_MODE_PAR_CHK;
/* XXX CXD1180 asserts MONBSY before disconnect */
if (sc->sc_rev == NCR_VARIANT_CXD1180)
mode &= ~SCI_MODE_MONBSY;

NCR5380_WRITE(sc, sci_mode, mode);

/*
* Another hack for the Sun3 "si", which needs
* some setup done to its DMA engine before the
* target puts the SCSI bus into any DATA phase.
*/
if (sr->sr_dma_hand && sc->sc_dma_setup) {
NCR_TRACE("reselect: call DMA setup, dh=0x%x\n",
(long) sr->sr_dma_hand);
sc->sc_dma_setup(sc);
}

/* Now consume the IDENTIFY message. */
ncr5380_pio_in(sc, PHASE_MSG_IN, 1, &msg);
return;
}

printf("%s: phantom reselect: target=%d, LUN=%d\n",
device_xname(sc->sc_dev), target, lun);
abort:
/*
* Try to send an ABORT message. This makes us
* temporarily busy, but no current command...
*/
sc->sc_state |= NCR_ABORTING;

/* Raise ATN, delay, raise ACK... */
icmd = SCI_ICMD_ATN;
NCR5380_WRITE(sc, sci_icmd, icmd);
delay(2);

/* Now consume the IDENTIFY message. */
ncr5380_pio_in(sc, PHASE_MSG_IN, 1, &msg);

/* Finally try to send the ABORT. */
sc->sc_prevphase = PHASE_INVALID;
sc->sc_msgpriq = SEND_ABORT;
ncr5380_msg_out(sc);

NCR5380_WRITE(sc, sci_tcmd, PHASE_INVALID);
NCR5380_WRITE(sc, sci_sel_enb, 0);
SCI_CLR_INTR(sc);
NCR5380_WRITE(sc, sci_sel_enb, 0x80);

sc->sc_state &= ~NCR_ABORTING;
}

/*
* Select target: xs is the transfer that we are selecting for.
* sc->sc_current should be NULL.
*
* Returns:
* sc->sc_current != NULL ==> we were reselected (race!)
* XS_NOERROR ==> selection worked
* XS_BUSY ==> lost arbitration
* XS_SELTIMEOUT ==> no response to selection
*/
static int
ncr5380_select(struct ncr5380_softc *sc, struct sci_req *sr)
{
int timo, s, target_mask;
uint8_t data, icmd, mode;

/* Check for reselect */
ncr5380_reselect(sc);
if (sc->sc_current) {
NCR_TRACE("select: reselect, cur=0x%x\n",
(long) sc->sc_current);
return XS_BUSY; /* reselected */
}

/*
* Set phase bits to 0, otherwise the 5380 won't drive the bus during
* selection.
*/
NCR5380_WRITE(sc, sci_tcmd, PHASE_DATA_OUT);
NCR5380_WRITE(sc, sci_icmd, 0);
icmd = 0;
NCR5380_WRITE(sc, sci_mode, 0);

/*
* Arbitrate for the bus. The 5380 takes care of the
* time-critical bus interactions. We set our ID bit
* in the output data register and set MODE_ARB. The
* 5380 watches for the required "bus free" period.
* If and when the "bus free" period is detected, the
* 5380 drives BSY, drives the data bus, and sets the
* "arbitration in progress" (AIP) bit to let us know
* arbitration has started (and that it asserts BSY).
* We then wait for one arbitration delay (2.2uS) and
* check the ICMD_LST bit, which will be set if some
* other target drives SEL during arbitration.
*
* There is a time-critical section during the period
* after we enter arbitration up until we assert SEL.
* Avoid long interrupts during this period.
*/
s = splvm(); /* XXX: Begin time-critical section */

NCR5380_WRITE(sc, sci_odata, 0x80); /* OUR_ID */
NCR5380_WRITE(sc, sci_mode, SCI_MODE_ARB);

#define WAIT_AIP_USEC 20 /* pleanty of time */
/* Wait for the AIP bit to turn on. */
timo = WAIT_AIP_USEC;
for (;;) {
if (NCR5380_READ(sc, sci_icmd) & SCI_ICMD_AIP)
break;
if (timo <= 0) {
/*
* Did not see any "bus free" period.
* The usual reason is a reselection,
* so treat this as arbitration loss.
*/
NCR_TRACE("select: bus busy, rc=%d\n", XS_BUSY);
goto lost_arb;
}
timo -= 2;
delay(2);
}
NCR_TRACE("select: have AIP after %d uSec.\n",
WAIT_AIP_USEC - timo);

/* Got AIP. Wait one arbitration delay (2.2 uS.) */
delay(3);

/* Check for ICMD_LST */
if (NCR5380_READ(sc, sci_icmd) & SCI_ICMD_LST) {
/* Some other target asserted SEL. */
NCR_TRACE("select: lost one, rc=%d\n", XS_BUSY);
goto lost_arb;
}

/*
* No other device has declared itself the winner.
* The spec. says to check for higher IDs, but we
* are always the highest (ID=7) so don't bother.
* We can now declare victory by asserting SEL.
*
* Note that the 5380 is asserting BSY because we
* have entered arbitration mode. We will now hold
* BSY directly so we can turn off ARB mode.
*/
icmd = (SCI_ICMD_BSY | SCI_ICMD_SEL);
NCR5380_WRITE(sc, sci_icmd, icmd);

/*
* "The SCSI device that wins arbitration shall wait
* at least a bus clear delay plus a bus settle delay
* after asserting the SEL signal before changing
* any [other] signal." (1.2uS. total)
*/
delay(2);

/*
* Check one last time to see if we really did
* win arbitration. This might only happen if
* there can be a higher selection ID than ours.
* Keep this code for reference anyway...
*/
/* XXX CXD1180 asserts LST here */
if ((sc->sc_rev != NCR_VARIANT_CXD1180) &&
(NCR5380_READ(sc, sci_icmd) & SCI_ICMD_LST)) {
/* Some other target asserted SEL. */
NCR_TRACE("select: lost two, rc=%d\n", XS_BUSY);

lost_arb:
NCR5380_WRITE(sc, sci_icmd, 0);
NCR5380_WRITE(sc, sci_mode, 0);

splx(s); /* XXX: End of time-critical section. */

/*
* When we lose arbitration, it usually means
* there is a target trying to reselect us.
*/
ncr5380_reselect(sc);
return XS_BUSY;
}

/* Leave ARB mode Now that we drive BSY+SEL */
NCR5380_WRITE(sc, sci_mode, 0);
NCR5380_WRITE(sc, sci_sel_enb, 0);

splx(s); /* XXX: End of time-critical section. */

/*
* Arbitration is complete. Now do selection:
* Drive the data bus with the ID bits for both
* the host and target. Also set ATN now, to
* ask the target for a message out phase.
*/
target_mask = (1 << sr->sr_target);
data = 0x80 | target_mask;
NCR5380_WRITE(sc, sci_odata, data);
icmd |= (SCI_ICMD_DATA | SCI_ICMD_ATN);
NCR5380_WRITE(sc, sci_icmd, icmd);
delay(2); /* two deskew delays. */

/* De-assert BSY (targets sample the data now). */
icmd &= ~SCI_ICMD_BSY;
NCR5380_WRITE(sc, sci_icmd, icmd);
delay(3); /* Bus settle delay. */

/*
* Wait for the target to assert BSY.
* SCSI spec. says wait for 250 mS.
*/
for (timo = 25000;;) {
if (NCR5380_READ(sc, sci_bus_csr) & SCI_BUS_BSY)
goto success;
if (--timo <= 0)
break;
delay(10);
}

/*
* There is no reaction from the target. Start the selection
* timeout procedure. We release the databus but keep SEL+ATN
* asserted. After that we wait a 'selection abort time' (200
* usecs) and 2 deskew delays (90 ns) and check BSY again.
* When BSY is asserted, we assume the selection succeeded,
* otherwise we release the bus.
*/
icmd &= ~SCI_ICMD_DATA;
NCR5380_WRITE(sc, sci_icmd, icmd);
delay(201);
if ((NCR5380_READ(sc, sci_bus_csr) & SCI_BUS_BSY) == 0) {
/* Really no device on bus */
NCR5380_WRITE(sc, sci_tcmd, PHASE_INVALID);
NCR5380_WRITE(sc, sci_icmd, 0);
NCR5380_WRITE(sc, sci_mode, 0);
NCR5380_WRITE(sc, sci_sel_enb, 0);
SCI_CLR_INTR(sc);
NCR5380_WRITE(sc, sci_sel_enb, 0x80);
NCR_TRACE("select: device down, rc=%d\n", XS_SELTIMEOUT);
return XS_SELTIMEOUT;
}

success:
/*
* The target is now driving BSY, so we can stop
* driving SEL and the data bus (keep ATN true).
* Configure the ncr5380 to monitor BSY, parity.
*/
icmd &= ~(SCI_ICMD_DATA | SCI_ICMD_SEL);
NCR5380_WRITE(sc, sci_icmd, icmd);

/* If this target's bit is set, do NOT check parity. */
if (sc->sc_parity_disable & target_mask)
mode = SCI_MODE_MONBSY;
else
mode = SCI_MODE_MONBSY | SCI_MODE_PAR_CHK;
/* XXX CXD1180 asserts MONBSY before disconnect */
if (sc->sc_rev == NCR_VARIANT_CXD1180)
mode &= ~SCI_MODE_MONBSY;

NCR5380_WRITE(sc, sci_mode, mode);

return XS_NOERROR;
}

/*****************************************************************
* Functions to handle each info. transfer phase:
*****************************************************************/

/*
* The message system:
*
* This is a revamped message system that now should easier accommodate
* new messages, if necessary.
*
* Currently we accept these messages:
* IDENTIFY (when reselecting)
* COMMAND COMPLETE # (expect bus free after messages marked #)
* NOOP
* MESSAGE REJECT
* SYNCHRONOUS DATA TRANSFER REQUEST
* SAVE DATA POINTER
* RESTORE POINTERS
* DISCONNECT #
*
* We may send these messages in prioritized order:
* BUS DEVICE RESET # if XS_CTL_RESET & xs->xs_control (or in
* weird sits.)
* MESSAGE PARITY ERROR par. err. during MSGI
* MESSAGE REJECT If we get a message we don't know how to handle
* ABORT # send on errors
* INITIATOR DETECTED ERROR also on errors (SCSI2) (during info xfer)
* IDENTIFY At the start of each transfer
* SYNCHRONOUS DATA TRANSFER REQUEST if appropriate
* NOOP if nothing else fits the bill ...
*/

/*
* Precondition:
* The SCSI bus is already in the MSGI phase and there is a message byte
* on the bus, along with an asserted REQ signal.
*
* Our return value determines whether our caller, ncr5380_machine()
* will expect to see another REQ (and possibly phase change).
*/
static int
ncr5380_msg_in(struct ncr5380_softc *sc)
{
struct sci_req *sr = sc->sc_current;
struct scsipi_xfer *xs = sr->sr_xs;
int n, phase;
int act_flags;
uint8_t icmd;

/* acknowledge phase change */
NCR5380_WRITE(sc, sci_tcmd, PHASE_MSG_IN);

act_flags = ACT_CONTINUE;
icmd = NCR5380_READ(sc, sci_icmd) & SCI_ICMD_RMASK;

if (sc->sc_prevphase == PHASE_MSG_IN) {
/* This is a continuation of the previous message. */
n = sc->sc_imp - sc->sc_imess;
NCR_TRACE("msg_in: continuation, n=%d\n", n);
goto nextbyte;
}

/* This is a new MESSAGE IN phase. Clean up our state. */
sc->sc_state &= ~NCR_DROP_MSGIN;

nextmsg:
n = 0;
sc->sc_imp = &sc->sc_imess[n];

nextbyte:
/*
* Read a whole message, but don't ack the last byte. If we reject the
* message, we have to assert ATN during the message transfer phase
* itself.
*/
for (;;) {
/*
* Read a message byte.
* First, check BSY, REQ, phase...
*/
if (!SCI_BUSY(sc)) {
NCR_TRACE("msg_in: lost BSY, n=%d\n", n);
/* XXX - Assume the command completed? */
act_flags |= (ACT_DISCONNECT | ACT_CMD_DONE);
return act_flags;
}
if (ncr5380_wait_req(sc)) {
NCR_TRACE("msg_in: BSY but no REQ, n=%d\n", n);
/* Just let ncr5380_machine() handle it... */
return act_flags;
}
phase = SCI_BUS_PHASE(NCR5380_READ(sc, sci_bus_csr));
if (phase != PHASE_MSG_IN) {
/*
* Target left MESSAGE IN, probably because it
* a) noticed our ATN signal, or
* b) ran out of messages.
*/
return act_flags;
}
/* Still in MESSAGE IN phase, and REQ is asserted. */
if (NCR5380_READ(sc, sci_csr) & SCI_CSR_PERR) {
ncr_sched_msgout(sc, SEND_PARITY_ERROR);
sc->sc_state |= NCR_DROP_MSGIN;
}

/* Gather incoming message bytes if needed. */
if ((sc->sc_state & NCR_DROP_MSGIN) == 0) {
if (n >= NCR_MAX_MSG_LEN) {
ncr_sched_msgout(sc, SEND_REJECT);
sc->sc_state |= NCR_DROP_MSGIN;
} else {
*sc->sc_imp++ = NCR5380_READ(sc, sci_data);
n++;
/*
* This testing is suboptimal, but most
* messages will be of the one byte variety, so
* it should not affect performance
* significantly.
*/
if (n == 1 && MSG_IS1BYTE(sc->sc_imess[0]))
goto have_msg;
if (n == 2 && MSG_IS2BYTE(sc->sc_imess[0]))
goto have_msg;
if (n >= 3 && MSG_ISEXTENDED(sc->sc_imess[0]) &&
n == sc->sc_imess[1] + 2)
goto have_msg;
}
}

/*
* If we reach this spot we're either:
* a) in the middle of a multi-byte message, or
* b) dropping bytes.
*/

/* Ack the last byte read. */
icmd |= SCI_ICMD_ACK;
NCR5380_WRITE(sc, sci_icmd, icmd);

if (ncr5380_wait_not_req(sc)) {
NCR_TRACE("msg_in: drop, stuck REQ, n=%d\n", n);
act_flags |= ACT_RESET_BUS;
}

icmd &= ~SCI_ICMD_ACK;
NCR5380_WRITE(sc, sci_icmd, icmd);

if (act_flags != ACT_CONTINUE)
return act_flags;

/* back to nextbyte */
}

have_msg:
/* We now have a complete message. Parse it. */

switch (sc->sc_imess[0]) {
case MSG_CMDCOMPLETE:
NCR_TRACE("msg_in: CMDCOMPLETE\n", 0);
/* Target is about to disconnect. */
act_flags |= (ACT_DISCONNECT | ACT_CMD_DONE);
break;

case MSG_PARITY_ERROR:
NCR_TRACE("msg_in: PARITY_ERROR\n", 0);
/* Resend the last message. */
ncr_sched_msgout(sc, sc->sc_msgout);
/* Reset icmd after scheduling the REJECT cmd - jwg */
icmd = NCR5380_READ(sc, sci_icmd) & SCI_ICMD_RMASK;
break;

case MSG_MESSAGE_REJECT:
/* The target rejects the last message we sent. */
NCR_TRACE("msg_in: got reject for 0x%x\n", sc->sc_msgout);
switch (sc->sc_msgout) {
case SEND_IDENTIFY:
/* Really old target controller? */
/* XXX ... */
break;
case SEND_INIT_DET_ERR:
goto abort;
}
break;

case MSG_NOOP:
NCR_TRACE("msg_in: NOOP\n", 0);
break;

case MSG_DISCONNECT:
NCR_TRACE("msg_in: DISCONNECT\n", 0);
/* Target is about to disconnect. */
act_flags |= ACT_DISCONNECT;
if ((xs->xs_periph->periph_quirks & PQUIRK_AUTOSAVE) == 0)
break;
/*FALLTHROUGH*/

case MSG_SAVEDATAPOINTER:
NCR_TRACE("msg_in: SAVE_PTRS\n", 0);
sr->sr_dataptr = sc->sc_dataptr;
sr->sr_datalen = sc->sc_datalen;
break;

case MSG_RESTOREPOINTERS:
NCR_TRACE("msg_in: RESTORE_PTRS\n", 0);
sc->sc_dataptr = sr->sr_dataptr;
sc->sc_datalen = sr->sr_datalen;
break;

case MSG_EXTENDED:
switch (sc->sc_imess[2]) {
case MSG_EXT_SDTR:
case MSG_EXT_WDTR:
/* The ncr5380 can not do synchronous mode. */
goto reject;
default:
printf("%s: unrecognized MESSAGE EXTENDED; "
"sending REJECT\n",
device_xname(sc->sc_dev));
NCR_BREAK();
goto reject;
}
break;

default:
NCR_TRACE("msg_in: eh? imsg=0x%x\n", sc->sc_imess[0]);
printf("%s: unrecognized MESSAGE; sending REJECT\n",
device_xname(sc->sc_dev));
NCR_BREAK();
/* fallthrough */
reject:
ncr_sched_msgout(sc, SEND_REJECT);
/* Reset icmd after scheduling the REJECT cmd - jwg */
icmd = NCR5380_READ(sc, sci_icmd) & SCI_ICMD_RMASK;
break;

abort:
sc->sc_state |= NCR_ABORTING;
ncr_sched_msgout(sc, SEND_ABORT);
break;
}

/* Ack the last byte read. */
icmd |= SCI_ICMD_ACK;
NCR5380_WRITE(sc, sci_icmd, icmd);

if (ncr5380_wait_not_req(sc)) {
NCR_TRACE("msg_in: last, stuck REQ, n=%d\n", n);
act_flags |= ACT_RESET_BUS;
}

icmd &= ~SCI_ICMD_ACK;
NCR5380_WRITE(sc, sci_icmd, icmd);

/* Go get the next message, if any. */
if (act_flags == ACT_CONTINUE)
goto nextmsg;

return act_flags;
}

/*
* The message out (and in) stuff is a bit complicated:
* If the target requests another message (sequence) without
* having changed phase in between it really asks for a
* retransmit, probably due to parity error(s).
* The following messages can be sent:
* IDENTIFY @ These 4 stem from SCSI command activity
* SDTR @
* WDTR @
* DEV_RESET @
* REJECT if MSGI doesn't make sense
* PARITY_ERROR if parity error while in MSGI
* INIT_DET_ERR if parity error while not in MSGI
* ABORT if INIT_DET_ERR rejected
* NOOP if asked for a message and there's nothing to send
*
* Note that we call this one with (sc_current == NULL)
* when sending ABORT for unwanted reselections.
*/
static int
ncr5380_msg_out(struct ncr5380_softc *sc)
{
struct sci_req *sr = sc->sc_current;
int act_flags, n, phase, progress;
uint8_t icmd, msg;

/* acknowledge phase change */
NCR5380_WRITE(sc, sci_tcmd, PHASE_MSG_OUT);

progress = 0; /* did we send any messages? */
act_flags = ACT_CONTINUE;

/*
* Set ATN. If we're just sending a trivial 1-byte message,
* we'll clear ATN later on anyway. Also drive the data bus.
*/
icmd = NCR5380_READ(sc, sci_icmd) & SCI_ICMD_RMASK;
icmd |= (SCI_ICMD_ATN | SCI_ICMD_DATA);
NCR5380_WRITE(sc, sci_icmd, icmd);

if (sc->sc_prevphase == PHASE_MSG_OUT) {
if (sc->sc_omp == sc->sc_omess) {
/*
* This is a retransmission.
*
* We get here if the target stayed in MESSAGE OUT
* phase. Section 5.1.9.2 of the SCSI 2 spec indicates
* that all of the previously transmitted messages must
* be sent again, in the same order. Therefore, we
* requeue all the previously transmitted messages, and
* start again from the top. Our simple priority
* scheme keeps the messages in the right order.
*/
sc->sc_msgpriq |= sc->sc_msgoutq;
NCR_TRACE("msg_out: retrans priq=0x%x\n",
sc->sc_msgpriq);
} else {
/* This is a continuation of the previous message. */
n = sc->sc_omp - sc->sc_omess;
NCR_TRACE("msg_out: continuation, n=%d\n", n);
goto nextbyte;
}
}

/* No messages transmitted so far. */
sc->sc_msgoutq = 0;

nextmsg:
/* Pick up highest priority message. */
sc->sc_msgout = sc->sc_msgpriq & -sc->sc_msgpriq;
sc->sc_msgpriq &= ~sc->sc_msgout;
sc->sc_msgoutq |= sc->sc_msgout;

/* Build the outgoing message data. */
switch (sc->sc_msgout) {
case SEND_IDENTIFY:
NCR_TRACE("msg_out: SEND_IDENTIFY\n", 0);
if (sr == NULL) {
printf("%s: SEND_IDENTIFY while not connected; "
"sending NOOP\n",
device_xname(sc->sc_dev));
NCR_BREAK();
goto noop;
}
/*
* The identify message we send determines whether
* disconnect/reselect is allowed for this command.
* 0xC0+LUN: allows it, 0x80+LUN disallows it.
*/
msg = 0xc0; /* MSG_IDENTIFY(0,1) */
if (sc->sc_no_disconnect & (1 << sr->sr_target))
msg = 0x80;
if (sr->sr_flags & (SR_IMMED))
msg = 0x80;
sc->sc_omess[0] = msg | sr->sr_lun;
n = 1;
break;

case SEND_DEV_RESET:
NCR_TRACE("msg_out: SEND_DEV_RESET\n", 0);
/* Expect disconnect after this! */
/* XXX: Kill jobs for this target? */
act_flags |= (ACT_DISCONNECT | ACT_CMD_DONE);
sc->sc_omess[0] = MSG_BUS_DEV_RESET;
n = 1;
break;

case SEND_REJECT:
NCR_TRACE("msg_out: SEND_REJECT\n", 0);
sc->sc_omess[0] = MSG_MESSAGE_REJECT;
n = 1;
break;

case SEND_PARITY_ERROR:
NCR_TRACE("msg_out: SEND_PARITY_ERROR\n", 0);
sc->sc_omess[0] = MSG_PARITY_ERROR;
n = 1;
break;

case SEND_INIT_DET_ERR:
NCR_TRACE("msg_out: SEND_INIT_DET_ERR\n", 0);
sc->sc_omess[0] = MSG_INITIATOR_DET_ERR;
n = 1;
break;

case SEND_ABORT:
NCR_TRACE("msg_out: SEND_ABORT\n", 0);
/* Expect disconnect after this! */
/* XXX: Set error flag? */
act_flags |= (ACT_DISCONNECT | ACT_CMD_DONE);
sc->sc_omess[0] = MSG_ABORT;
n = 1;
break;

case 0:
printf("%s: unexpected MESSAGE OUT; sending NOOP\n",
device_xname(sc->sc_dev));
NCR_BREAK();
noop:
NCR_TRACE("msg_out: send NOOP\n", 0);
sc->sc_omess[0] = MSG_NOOP;
n = 1;
break;

default:
printf("%s: weird MESSAGE OUT; sending NOOP\n",
device_xname(sc->sc_dev));
NCR_BREAK();
goto noop;
}
sc->sc_omp = &sc->sc_omess[n];

nextbyte:
/* Send message bytes. */
while (n > 0) {
/*
* Send a message byte.
* First check BSY, REQ, phase...
*/
if (!SCI_BUSY(sc)) {
NCR_TRACE("msg_out: lost BSY, n=%d\n", n);
goto out;
}
if (ncr5380_wait_req(sc)) {
NCR_TRACE("msg_out: no REQ, n=%d\n", n);
goto out;
}
phase = SCI_BUS_PHASE(NCR5380_READ(sc, sci_bus_csr));
if (phase != PHASE_MSG_OUT) {
/*
* Target left MESSAGE OUT, possibly to reject
* our message.
*/
NCR_TRACE("msg_out: new phase=%d\n", phase);
goto out;
}

/* Yes, we can send this message byte. */
--n;

/* Clear ATN before last byte if this is the last message. */
if (n == 0 && sc->sc_msgpriq == 0) {
icmd &= ~SCI_ICMD_ATN;
NCR5380_WRITE(sc, sci_icmd, icmd);
/* 2 deskew delays */
delay(2); /* XXX */
}

/* Put data on the bus. */
NCR5380_WRITE(sc, sci_odata, *--sc->sc_omp);

/* Raise ACK to tell target data is on the bus. */
icmd |= SCI_ICMD_ACK;
NCR5380_WRITE(sc, sci_icmd, icmd);

/* Wait for REQ to be negated. */
if (ncr5380_wait_not_req(sc)) {
NCR_TRACE("msg_out: stuck REQ, n=%d\n", n);
act_flags |= ACT_RESET_BUS;
}

/* Finally, drop ACK. */
icmd &= ~SCI_ICMD_ACK;
NCR5380_WRITE(sc, sci_icmd, icmd);

/* Stuck bus or something... */
if (act_flags & ACT_RESET_BUS)
goto out;

}
progress++;

/* We get here only if the entire message has been transmitted. */
if (sc->sc_msgpriq != 0) {
/* There are more outgoing messages. */
goto nextmsg;
}

/*
* The last message has been transmitted. We need to remember the last
* message transmitted (in case the target switches to MESSAGE IN phase
* and sends a MESSAGE REJECT), and the list of messages transmitted
* this time around (in case the target stays in MESSAGE OUT phase to
* request a retransmit).
*/

out:
/* Stop driving the data bus. */
icmd &= ~SCI_ICMD_DATA;
NCR5380_WRITE(sc, sci_icmd, icmd);

if (!progress)
act_flags |= ACT_RESET_BUS;

return act_flags;
}

/*
* Handle command phase.
*/
static int
ncr5380_command(struct ncr5380_softc *sc)
{
struct sci_req *sr = sc->sc_current;
struct scsipi_xfer *xs = sr->sr_xs;
int len;

/* acknowledge phase change */
NCR5380_WRITE(sc, sci_tcmd, PHASE_COMMAND);

/* Assume command can be sent in one go. */
/* XXX: Do this using DMA, and get a phase change intr? */
len = ncr5380_pio_out(sc, PHASE_COMMAND, xs->cmdlen,
(uint8_t *)xs->cmd);

if (len != xs->cmdlen) {
#ifdef NCR5380_DEBUG
printf("%s: short transfer: wanted %d got %d.\n",
__func__, xs->cmdlen, len);
ncr5380_show_scsi_cmd(xs);
NCR_BREAK();
#endif
if (len < 6) {
xs->error = XS_DRIVER_STUFFUP;
sc->sc_state |= NCR_ABORTING;
ncr_sched_msgout(sc, SEND_ABORT);
}

}

return ACT_CONTINUE;
}

/*
* Handle either data_in or data_out
*/
static int
ncr5380_data_xfer(struct ncr5380_softc *sc, int phase)
{
struct sci_req *sr = sc->sc_current;
struct scsipi_xfer *xs = sr->sr_xs;
int expected_phase;
int len;

/*
* When aborting a command, disallow any data phase.
*/
if (sc->sc_state & NCR_ABORTING) {
printf("%s: aborting, but phase=%s (reset)\n",
device_xname(sc->sc_dev), phase_names[phase & 7]);
return ACT_RESET_BUS; /* XXX */
}

/* Validate expected phase (data_in or data_out) */
expected_phase = (xs->xs_control & XS_CTL_DATA_OUT) ?
PHASE_DATA_OUT : PHASE_DATA_IN;
if (phase != expected_phase) {
printf("%s: data phase error\n", device_xname(sc->sc_dev));
goto abort;
}

/* Make sure we have some data to move. */
if (sc->sc_datalen <= 0) {
/* Device needs padding. */
if (phase == PHASE_DATA_IN)
ncr5380_pio_in(sc, phase, 4096, NULL);
else
ncr5380_pio_out(sc, phase, 4096, NULL);
/* Make sure that caused a phase change. */
if (SCI_BUS_PHASE(NCR5380_READ(sc, sci_bus_csr)) == phase) {
/* More than 4k is just too much! */
printf("%s: too much data padding\n",
device_xname(sc->sc_dev));
goto abort;
}
return ACT_CONTINUE;
}

/*
* Attempt DMA only if dma_alloc gave us a DMA handle AND
* there is enough left to transfer so DMA is worth while.
*/
if (sr->sr_dma_hand &&
(sc->sc_datalen >= sc->sc_min_dma_len))
{
/*
* OK, really start DMA. Note, the MD start function
* is responsible for setting the TCMD register, etc.
* (Acknowledge the phase change there, not here.)
*/
NCR_TRACE("data_xfer: dma_start, dh=0x%x\n",
(long) sr->sr_dma_hand);
(*sc->sc_dma_start)(sc);
return ACT_WAIT_DMA;
}

/*
* Doing PIO for data transfer. (Possibly "Pseudo DMA")
* XXX: Do PDMA functions need to set tcmd later?
*/
NCR_TRACE("data_xfer: doing PIO, len=%d\n", sc->sc_datalen);
/* acknowledge phase change */
NCR5380_WRITE(sc, sci_tcmd, phase); /* XXX: OK for PDMA? */
if (phase == PHASE_DATA_OUT) {
len = (*sc->sc_pio_out)(sc, phase, sc->sc_datalen,
sc->sc_dataptr);
} else {
len = (*sc->sc_pio_in)(sc, phase, sc->sc_datalen,
sc->sc_dataptr);
}
sc->sc_dataptr += len;
sc->sc_datalen -= len;

NCR_TRACE("data_xfer: did PIO, resid=%d\n", sc->sc_datalen);
return ACT_CONTINUE;

abort:
sc->sc_state |= NCR_ABORTING;
ncr_sched_msgout(sc, SEND_ABORT);
return ACT_CONTINUE;
}

static int
ncr5380_status(struct ncr5380_softc *sc)
{
int len;
uint8_t status;
struct sci_req *sr = sc->sc_current;

/* acknowledge phase change */
NCR5380_WRITE(sc, sci_tcmd, PHASE_STATUS);

len = ncr5380_pio_in(sc, PHASE_STATUS, 1, &status);
if (len) {
sr->sr_status = status;
} else {
printf("%s: none?\n", __func__);
}

return ACT_CONTINUE;
}

/*
* This is the big state machine that follows SCSI phase changes.
* This is somewhat like a co-routine. It will do a SCSI command,
* and exit if the command is complete, or if it must wait, i.e.
* for DMA to complete or for reselect to resume the job.
*
* The bus must be selected, and we need to know which command is
* being undertaken.
*/
static void
ncr5380_machine(struct ncr5380_softc *sc)
{
struct sci_req *sr;
struct scsipi_xfer *xs;
int act_flags, phase, timo;

#ifdef DIAGNOSTIC
if (sc->sc_state == NCR_IDLE)
panic("%s: state=idle", __func__);
if (sc->sc_current == NULL)
panic("%s: no current cmd", __func__);
#endif

sr = sc->sc_current;
xs = sr->sr_xs;
act_flags = ACT_CONTINUE;

/*
* This will be called by ncr5380_intr() when DMA is
* complete. Must stop DMA before touching the 5380 or
* there will be "register conflict" errors.
*/
if (sc->sc_state & NCR_DOINGDMA) {
/* Pick-up where where we left off... */
goto dma_done;
}

next_phase:

if (!SCI_BUSY(sc)) {
/* Unexpected disconnect */
printf("%s: unexpected disconnect.\n", __func__);
xs->error = XS_DRIVER_STUFFUP;
act_flags |= (ACT_DISCONNECT | ACT_CMD_DONE);
goto do_actions;
}

/*
* Wait for REQ before reading the phase.
* Need to wait longer than usual here, because
* some devices are just plain slow...
*/
timo = ncr5380_wait_phase_timo;
for (;;) {
if (NCR5380_READ(sc, sci_bus_csr) & SCI_BUS_REQ)
break;
if (--timo <= 0) {
if (sc->sc_state & NCR_ABORTING) {
printf("%s: no REQ while aborting, reset\n",
device_xname(sc->sc_dev));
act_flags |= ACT_RESET_BUS;
goto do_actions;
}
printf("%s: no REQ for next phase, abort\n",
device_xname(sc->sc_dev));
sc->sc_state |= NCR_ABORTING;
ncr_sched_msgout(sc, SEND_ABORT);
goto next_phase;
}
delay(100);
}

phase = SCI_BUS_PHASE(NCR5380_READ(sc, sci_bus_csr));
NCR_TRACE("machine: phase=%s\n",
(long) phase_names[phase & 7]);

/*
* We assume that the device knows what it's doing,
* so any phase is good.
*/

#if 0
/*
* XXX: Do not ACK the phase yet! do it later...
* XXX: ... each phase routine does that itself.
* In particular, DMA needs it done LATER.
*/
NCR5380_WRITE(sc, sci_tcmd, phase); /* acknowledge phase change */
#endif

switch (phase) {

case PHASE_DATA_OUT:
case PHASE_DATA_IN:
act_flags = ncr5380_data_xfer(sc, phase);
break;

case PHASE_COMMAND:
act_flags = ncr5380_command(sc);
break;

case PHASE_STATUS:
act_flags = ncr5380_status(sc);
break;

case PHASE_MSG_OUT:
act_flags = ncr5380_msg_out(sc);
break;

case PHASE_MSG_IN:
act_flags = ncr5380_msg_in(sc);
break;

default:
printf("%s: Unexpected phase 0x%x\n", __func__, phase);
sc->sc_state |= NCR_ABORTING;
ncr_sched_msgout(sc, SEND_ABORT);
goto next_phase;

} /* switch */
sc->sc_prevphase = phase;

do_actions:

if (act_flags & ACT_WAIT_DMA) {
act_flags &= ~ACT_WAIT_DMA;
/* Wait for DMA to complete (polling, or interrupt). */
if ((sr->sr_flags & SR_IMMED) == 0) {
NCR_TRACE("machine: wait for DMA intr.\n", 0);
return; /* will resume at dma_done */
}
/* Busy-wait for it to finish. */
NCR_TRACE("machine: dma_poll, dh=0x%x\n",
(long) sr->sr_dma_hand);
(*sc->sc_dma_poll)(sc);
dma_done:
/* Return here after interrupt. */
if (sr->sr_flags & SR_OVERDUE)
sc->sc_state |= NCR_ABORTING;
NCR_TRACE("machine: dma_stop, dh=0x%x\n",
(long) sr->sr_dma_hand);
(*sc->sc_dma_stop)(sc);
SCI_CLR_INTR(sc); /* XXX */
/*
* While DMA is running we can not touch the SBC,
* so various places just set NCR_ABORTING and
* expect us the "kick it" when DMA is done.
*/
if (sc->sc_state & NCR_ABORTING) {
ncr_sched_msgout(sc, SEND_ABORT);
}
}

/*
* Check for parity error.
* XXX - better place to check?
*/
if (NCR5380_READ(sc, sci_csr) & SCI_CSR_PERR) {
printf("%s: parity error!\n", device_xname(sc->sc_dev));
/* XXX: sc->sc_state |= NCR_ABORTING; */
ncr_sched_msgout(sc, SEND_PARITY_ERROR);
}

if (act_flags == ACT_CONTINUE)
goto next_phase;
/* All other actions "break" from the loop. */

NCR_TRACE("machine: act_flags=0x%x\n", act_flags);

if (act_flags & ACT_RESET_BUS) {
act_flags |= ACT_CMD_DONE;
/*
* Reset the SCSI bus, usually due to a timeout.
* The error code XS_TIMEOUT allows retries.
*/
sc->sc_state |= NCR_ABORTING;
printf("%s: reset SCSI bus for TID=%d LUN=%d\n",
device_xname(sc->sc_dev), sr->sr_target, sr->sr_lun);
ncr5380_reset_scsibus(sc);
}

if (act_flags & ACT_CMD_DONE) {
act_flags |= ACT_DISCONNECT;
/* Need to call scsipi_done() */
/* XXX: from the aic6360 driver, but why? */
if (sc->sc_datalen < 0) {
printf("%s: %d extra bytes from %d:%d\n",
device_xname(sc->sc_dev), -sc->sc_datalen,
sr->sr_target, sr->sr_lun);
sc->sc_datalen = 0;
}
xs->resid = sc->sc_datalen;
/* Note: this will clear sc_current */
NCR_TRACE("machine: call done, cur=0x%x\n", (long)sr);
ncr5380_done(sc);
}

if (act_flags & ACT_DISCONNECT) {
/*
* The device has dropped BSY (or will soon).
* We have to wait here for BSY to drop, otherwise
* the next command may decide we need a bus reset.
*/
timo = ncr5380_wait_req_timo; /* XXX */
for (;;) {
if (!SCI_BUSY(sc))
goto busfree;
if (--timo <= 0)
break;
delay(2);
}
/* Device is sitting on the bus! */
printf("%s: Target %d LUN %d stuck busy, resetting...\n",
device_xname(sc->sc_dev), sr->sr_target, sr->sr_lun);
ncr5380_reset_scsibus(sc);
busfree:
NCR_TRACE("machine: discon, waited %d\n",
ncr5380_wait_req_timo - timo);

NCR5380_WRITE(sc, sci_icmd, 0);
NCR5380_WRITE(sc, sci_mode, 0);
NCR5380_WRITE(sc, sci_tcmd, PHASE_INVALID);
NCR5380_WRITE(sc, sci_sel_enb, 0);
SCI_CLR_INTR(sc);
NCR5380_WRITE(sc, sci_sel_enb, 0x80);

if ((act_flags & ACT_CMD_DONE) == 0) {
NCR_TRACE("machine: discon, cur=0x%x\n", (long)sr);
}

/*
* We may be here due to a disconnect message,
* in which case we did NOT call ncr5380_done,
* and we need to clear sc_current.
*/
sc->sc_state = NCR_IDLE;
sc->sc_current = NULL;

/* Paranoia: clear everything. */
sc->sc_dataptr = NULL;
sc->sc_datalen = 0;
sc->sc_prevphase = PHASE_INVALID;
sc->sc_msgpriq = 0;
sc->sc_msgoutq = 0;
sc->sc_msgout = 0;

/* Our caller will re-enable interrupts. */
}
}

#ifdef NCR5380_DEBUG

static void
ncr5380_show_scsi_cmd(struct scsipi_xfer *xs)
{
uint8_t *b = (uint8_t *)xs->cmd;
int i = 0;

scsipi_printaddr(xs->xs_periph);
if ((xs->xs_control & XS_CTL_RESET) == 0) {
while (i < xs->cmdlen) {
if (i)
printf(",");
printf("%x",b[i++]);
}
printf("\n");
} else {
printf("RESET\n");
}
}

int ncr5380_traceidx = 0;

#define TRACE_MAX 1024
struct trace_ent {
const char *msg;
long val;
} ncr5380_tracebuf[TRACE_MAX];

void
ncr5380_trace(const char *msg, long val)
{
struct trace_ent *tr;
int s;

s = splbio();

tr = &ncr5380_tracebuf[ncr5380_traceidx];

ncr5380_traceidx++;
if (ncr5380_traceidx >= TRACE_MAX)
ncr5380_traceidx = 0;

tr->msg = msg;
tr->val = val;

splx(s);
}

#ifdef DDB
void
ncr5380_clear_trace(void)
{

ncr5380_traceidx = 0;
memset((char *)ncr5380_tracebuf, 0, sizeof(ncr5380_tracebuf));
}

void
ncr5380_show_trace(void)
{
struct trace_ent *tr;
int idx;

idx = ncr5380_traceidx;
do {
tr = &ncr5380_tracebuf[idx];
idx++;
if (idx >= TRACE_MAX)
idx = 0;
if (tr->msg)
db_printf(tr->msg, tr->val);
} while (idx != ncr5380_traceidx);
}

void
ncr5380_show_req(struct sci_req *sr)
{
struct scsipi_xfer *xs = sr->sr_xs;

db_printf("TID=%d ", sr->sr_target);
db_printf("LUN=%d ", sr->sr_lun);
db_printf("dh=%p ", sr->sr_dma_hand);
db_printf("dptr=%p ", sr->sr_dataptr);
db_printf("dlen=0x%x ", sr->sr_datalen);
db_printf("flags=%d ", sr->sr_flags);
db_printf("stat=%d ", sr->sr_status);

if (xs == NULL) {
db_printf("(xs=NULL)\n");
return;
}
db_printf("\n");
#ifdef SCSIPI_DEBUG
show_scsipi_xs(xs);
#else
db_printf("xs=%p\n", xs);
#endif
}

void
ncr5380_show_state(void)
{
struct ncr5380_softc *sc;
struct sci_req *sr;
int i, j, k;

sc = ncr5380_debug_sc;

if (sc == NULL) {
db_printf("ncr5380_debug_sc == NULL\n");
return;
}

db_printf("sc_ncmds=%d\n", sc->sc_ncmds);
k = -1; /* which is current? */
for (i = 0; i < SCI_OPENINGS; i++) {
sr = &sc->sc_ring[i];
if (sr->sr_xs) {
if (sr == sc->sc_current)
k = i;
db_printf("req %d: (sr=%p)", i, sr);
ncr5380_show_req(sr);
}
}
db_printf("sc_rr=%d, current=%d\n", sc->sc_rr, k);

db_printf("Active request matrix:\n");
for(i = 0; i < 8; i++) { /* targets */
for (j = 0; j < 8; j++) { /* LUN */
sr = sc->sc_matrix[i][j];
if (sr) {
db_printf("TID=%d LUN=%d sr=%p\n", i, j, sr);
}
}
}

db_printf("sc_state=0x%x\n", sc->sc_state);
db_printf("sc_current=%p\n", sc->sc_current);
db_printf("sc_dataptr=%p\n", sc->sc_dataptr);
db_printf("sc_datalen=0x%x\n", sc->sc_datalen);

db_printf("sc_prevphase=%d\n", sc->sc_prevphase);
db_printf("sc_msgpriq=0x%x\n", sc->sc_msgpriq);
}
#endif /* DDB */
#endif /* NCR5380_DEBUG */

void
ncr5380_attach(struct ncr5380_softc *sc)
{
struct scsipi_adapter *adapt = &sc->sc_adapter;
struct scsipi_channel *chan = &sc->sc_channel;

/*
* Fill in the scsipi_adapter.
*/
adapt->adapt_request = ncr5380_scsipi_request;
adapt->adapt_dev = sc->sc_dev;
adapt->adapt_nchannels = 1;
adapt->adapt_openings = SCI_OPENINGS;
adapt->adapt_max_periph = 1;
if (sc->sc_flags & NCR5380_FORCE_POLLING)
adapt->adapt_flags |= SCSIPI_ADAPT_POLL_ONLY;
/* adapt_minphys filled in by front-end */

/*
* Fill in the scsipi_channel.
*/
chan->chan_adapter = adapt;
chan->chan_bustype = &scsi_bustype;
chan->chan_channel = 0;
chan->chan_ntargets = 8;
chan->chan_nluns = 8;
/* chan_id filled in by front-end */

/*
* Add reference to adapter so that we drop the reference after
* config_found() to make sure the adapter is disabled.
*/
if (scsipi_adapter_addref(adapt) != 0) {
aprint_error_dev(sc->sc_dev, "unable to enable controller\n");
return;
}

ncr5380_init(sc); /* Init chip and driver */
ncr5380_reset_scsibus(sc);

/*
* Ask the adapter what subunits are present
*/
(void)config_found(sc->sc_dev, chan, scsiprint, CFARGS_NONE);
scsipi_adapter_delref(adapt);
}

int
ncr5380_detach(struct ncr5380_softc *sc, int flags)
{

return EOPNOTSUPP;
}