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ncr53c9x.c revision 1.129
      1 /*	$NetBSD: ncr53c9x.c,v 1.129 2007/08/20 12:32:30 tsutsui Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998, 2002 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Charles M. Hannum.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*
     40  * Copyright (c) 1994 Peter Galbavy
     41  * Copyright (c) 1995 Paul Kranenburg
     42  * All rights reserved.
     43  *
     44  * Redistribution and use in source and binary forms, with or without
     45  * modification, are permitted provided that the following conditions
     46  * are met:
     47  * 1. Redistributions of source code must retain the above copyright
     48  *    notice, this list of conditions and the following disclaimer.
     49  * 2. Redistributions in binary form must reproduce the above copyright
     50  *    notice, this list of conditions and the following disclaimer in the
     51  *    documentation and/or other materials provided with the distribution.
     52  * 3. All advertising materials mentioning features or use of this software
     53  *    must display the following acknowledgement:
     54  *	This product includes software developed by Peter Galbavy
     55  * 4. The name of the author may not be used to endorse or promote products
     56  *    derived from this software without specific prior written permission.
     57  *
     58  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     59  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     60  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     61  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
     62  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     63  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     64  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     66  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
     67  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     68  * POSSIBILITY OF SUCH DAMAGE.
     69  */
     70 
     71 /*
     72  * Based on aic6360 by Jarle Greipsland
     73  *
     74  * Acknowledgements: Many of the algorithms used in this driver are
     75  * inspired by the work of Julian Elischer (julian (at) tfs.com) and
     76  * Charles Hannum (mycroft (at) duality.gnu.ai.mit.edu).  Thanks a million!
     77  */
     78 
     79 #include <sys/cdefs.h>
     80 __KERNEL_RCSID(0, "$NetBSD: ncr53c9x.c,v 1.129 2007/08/20 12:32:30 tsutsui Exp $");
     81 
     82 #include <sys/param.h>
     83 #include <sys/systm.h>
     84 #include <sys/callout.h>
     85 #include <sys/kernel.h>
     86 #include <sys/errno.h>
     87 #include <sys/ioctl.h>
     88 #include <sys/device.h>
     89 #include <sys/buf.h>
     90 #include <sys/malloc.h>
     91 #include <sys/proc.h>
     92 #include <sys/queue.h>
     93 #include <sys/pool.h>
     94 #include <sys/scsiio.h>
     95 
     96 #include <dev/scsipi/scsi_spc.h>
     97 #include <dev/scsipi/scsi_all.h>
     98 #include <dev/scsipi/scsipi_all.h>
     99 #include <dev/scsipi/scsiconf.h>
    100 #include <dev/scsipi/scsi_message.h>
    101 
    102 #include <dev/ic/ncr53c9xreg.h>
    103 #include <dev/ic/ncr53c9xvar.h>
    104 
    105 int ncr53c9x_debug = NCR_SHOWMISC; /*NCR_SHOWPHASE|NCR_SHOWMISC|NCR_SHOWTRAC|NCR_SHOWCMDS;*/
    106 #ifdef DEBUG
    107 int ncr53c9x_notag = 0;
    108 #endif
    109 
    110 /*static*/ void	ncr53c9x_readregs(struct ncr53c9x_softc *);
    111 /*static*/ void	ncr53c9x_select(struct ncr53c9x_softc *, struct ncr53c9x_ecb *);
    112 /*static*/ int ncr53c9x_reselect(struct ncr53c9x_softc *, int, int, int);
    113 /*static*/ void	ncr53c9x_scsi_reset(struct ncr53c9x_softc *);
    114 /*static*/ void ncr53c9x_clear(struct ncr53c9x_softc *, scsipi_xfer_result_t);
    115 /*static*/ int	ncr53c9x_poll(struct ncr53c9x_softc *,
    116 			      struct scsipi_xfer *, int);
    117 /*static*/ void	ncr53c9x_sched(struct ncr53c9x_softc *);
    118 /*static*/ void	ncr53c9x_done(struct ncr53c9x_softc *, struct ncr53c9x_ecb *);
    119 /*static*/ void	ncr53c9x_msgin(struct ncr53c9x_softc *);
    120 /*static*/ void	ncr53c9x_msgout(struct ncr53c9x_softc *);
    121 /*static*/ void	ncr53c9x_timeout(void *arg);
    122 /*static*/ void	ncr53c9x_watch(void *arg);
    123 /*static*/ void	ncr53c9x_abort(struct ncr53c9x_softc *, struct ncr53c9x_ecb *);
    124 /*static*/ void ncr53c9x_dequeue(struct ncr53c9x_softc *,
    125 				struct ncr53c9x_ecb *);
    126 /*static*/ int	ncr53c9x_ioctl(struct scsipi_channel *, u_long,
    127 			       void *, int, struct proc *);
    128 
    129 void ncr53c9x_sense(struct ncr53c9x_softc *, struct ncr53c9x_ecb *);
    130 void ncr53c9x_free_ecb(struct ncr53c9x_softc *, struct ncr53c9x_ecb *);
    131 struct ncr53c9x_ecb *ncr53c9x_get_ecb(struct ncr53c9x_softc *, int);
    132 
    133 static inline int ncr53c9x_stp2cpb(struct ncr53c9x_softc *, int);
    134 static inline void ncr53c9x_setsync(struct ncr53c9x_softc *,
    135 				    struct ncr53c9x_tinfo *);
    136 void   ncr53c9x_update_xfer_mode (struct ncr53c9x_softc *, int);
    137 static struct ncr53c9x_linfo *ncr53c9x_lunsearch(struct ncr53c9x_tinfo *,
    138 						 int64_t lun);
    139 
    140 static void ncr53c9x_wrfifo(struct ncr53c9x_softc *, u_char *, int);
    141 
    142 static int  ncr53c9x_rdfifo(struct ncr53c9x_softc *, int);
    143 #define NCR_RDFIFO_START   0
    144 #define NCR_RDFIFO_CONTINUE 1
    145 
    146 
    147 #define NCR_SET_COUNT(sc, size) do { \
    148 		NCR_WRITE_REG((sc), NCR_TCL, (size)); 			\
    149 		NCR_WRITE_REG((sc), NCR_TCM, (size) >> 8);		\
    150 		if ((sc->sc_cfg2 & NCRCFG2_FE) || 			\
    151 		    (sc->sc_rev == NCR_VARIANT_FAS366)) {		\
    152 			NCR_WRITE_REG((sc), NCR_TCH, (size) >> 16);	\
    153 		}							\
    154 		if (sc->sc_rev == NCR_VARIANT_FAS366) {			\
    155 			NCR_WRITE_REG(sc, NCR_RCH, 0);			\
    156 		}							\
    157 } while (/* CONSTCOND */0)
    158 
    159 static int ecb_pool_initialized = 0;
    160 static struct pool ecb_pool;
    161 
    162 /*
    163  * Names for the NCR53c9x variants, corresponding to the variant tags
    164  * in ncr53c9xvar.h.
    165  */
    166 static const char *ncr53c9x_variant_names[] = {
    167 	"ESP100",
    168 	"ESP100A",
    169 	"ESP200",
    170 	"NCR53C94",
    171 	"NCR53C96",
    172 	"ESP406",
    173 	"FAS408",
    174 	"FAS216",
    175 	"AM53C974",
    176 	"FAS366/HME",
    177 	"NCR53C90 (86C01)",
    178 };
    179 
    180 /*
    181  * Search linked list for LUN info by LUN id.
    182  */
    183 static struct ncr53c9x_linfo *
    184 ncr53c9x_lunsearch(struct ncr53c9x_tinfo *ti, int64_t lun)
    185 {
    186 	struct ncr53c9x_linfo *li;
    187 
    188 	LIST_FOREACH(li, &ti->luns, link)
    189 		if (li->lun == lun)
    190 			return li;
    191 	return NULL;
    192 }
    193 
    194 /*
    195  * Attach this instance, and then all the sub-devices
    196  */
    197 void
    198 ncr53c9x_attach(struct ncr53c9x_softc *sc)
    199 {
    200 	struct scsipi_adapter *adapt = &sc->sc_adapter;
    201 	struct scsipi_channel *chan = &sc->sc_channel;
    202 
    203 	simple_lock_init(&sc->sc_lock);
    204 
    205 	callout_init(&sc->sc_watchdog, 0);
    206 
    207 	/*
    208 	 * Note, the front-end has set us up to print the chip variation.
    209 	 */
    210 	if (sc->sc_rev >= NCR_VARIANT_MAX) {
    211 		printf("\n%s: unknown variant %d, devices not attached\n",
    212 		    sc->sc_dev.dv_xname, sc->sc_rev);
    213 		return;
    214 	}
    215 
    216 	printf(": %s, %dMHz, SCSI ID %d\n",
    217 	    ncr53c9x_variant_names[sc->sc_rev], sc->sc_freq, sc->sc_id);
    218 
    219 	sc->sc_ntarg = (sc->sc_rev == NCR_VARIANT_FAS366) ? 16 : 8;
    220 
    221 	/*
    222 	 * Allocate SCSI message buffers.
    223 	 * Front-ends can override allocation to avoid alignment
    224 	 * handling in the DMA engines. Note that that ncr53c9x_msgout()
    225 	 * can request a 1 byte DMA transfer.
    226 	 */
    227 	if (sc->sc_omess == NULL)
    228 		sc->sc_omess = malloc(NCR_MAX_MSG_LEN, M_DEVBUF, M_NOWAIT);
    229 
    230 	if (sc->sc_imess == NULL)
    231 		sc->sc_imess = malloc(NCR_MAX_MSG_LEN + 1, M_DEVBUF, M_NOWAIT);
    232 
    233 	sc->sc_tinfo = malloc(sc->sc_ntarg * sizeof(sc->sc_tinfo[0]),
    234 	    M_DEVBUF, M_NOWAIT | M_ZERO);
    235 
    236 	if (sc->sc_omess == NULL || sc->sc_imess == NULL ||
    237 	    sc->sc_tinfo == NULL) {
    238 		printf("out of memory\n");
    239 		return;
    240 	}
    241 
    242 	/*
    243 	 * Treat NCR53C90 with the 86C01 DMA chip exactly as ESP100
    244 	 * from now on.
    245 	 */
    246 	if (sc->sc_rev == NCR_VARIANT_NCR53C90_86C01)
    247 		sc->sc_rev = NCR_VARIANT_ESP100;
    248 
    249 	sc->sc_ccf = FREQTOCCF(sc->sc_freq);
    250 
    251 	/* The value *must not* be == 1. Make it 2 */
    252 	if (sc->sc_ccf == 1)
    253 		sc->sc_ccf = 2;
    254 
    255 	/*
    256 	 * The recommended timeout is 250ms. This register is loaded
    257 	 * with a value calculated as follows, from the docs:
    258 	 *
    259 	 *		(timout period) x (CLK frequency)
    260 	 *	reg = -------------------------------------
    261 	 *		 8192 x (Clock Conversion Factor)
    262 	 *
    263 	 * Since CCF has a linear relation to CLK, this generally computes
    264 	 * to the constant of 153.
    265 	 */
    266 	sc->sc_timeout = ((250 * 1000) * sc->sc_freq) / (8192 * sc->sc_ccf);
    267 
    268 	/* CCF register only has 3 bits; 0 is actually 8 */
    269 	sc->sc_ccf &= 7;
    270 
    271 	/*
    272 	 * Fill in the scsipi_adapter.
    273 	 */
    274 	adapt->adapt_dev = &sc->sc_dev;
    275 	adapt->adapt_nchannels = 1;
    276 	adapt->adapt_openings = 256;
    277 	adapt->adapt_max_periph = 256;
    278 	adapt->adapt_ioctl = ncr53c9x_ioctl;
    279 	/* adapt_request initialized by front-end */
    280 	/* adapt_minphys initialized by front-end */
    281 
    282 	/*
    283 	 * Fill in the scsipi_channel.
    284 	 */
    285 	memset(chan, 0, sizeof(*chan));
    286 	chan->chan_adapter = adapt;
    287 	chan->chan_bustype = &scsi_bustype;
    288 	chan->chan_channel = 0;
    289 	chan->chan_ntargets = sc->sc_ntarg;
    290 	chan->chan_nluns = 8;
    291 	chan->chan_id = sc->sc_id;
    292 
    293 	/*
    294 	 * Add reference to adapter so that we drop the reference after
    295 	 * config_found() to make sure the adatper is disabled.
    296 	 */
    297 	if (scsipi_adapter_addref(adapt) != 0) {
    298 		printf("%s: unable to enable controller\n",
    299 		    sc->sc_dev.dv_xname);
    300 		return;
    301 	}
    302 
    303 	/* Reset state & bus */
    304 	sc->sc_cfflags = device_cfdata(&sc->sc_dev)->cf_flags;
    305 	sc->sc_state = 0;
    306 	ncr53c9x_init(sc, 1);
    307 
    308 	/*
    309 	 * Now try to attach all the sub-devices
    310 	 */
    311 	sc->sc_child = config_found(&sc->sc_dev, &sc->sc_channel, scsiprint);
    312 
    313 	scsipi_adapter_delref(adapt);
    314 	callout_reset(&sc->sc_watchdog, 60 * hz, ncr53c9x_watch, sc);
    315 }
    316 
    317 int
    318 ncr53c9x_detach(struct ncr53c9x_softc *sc, int flags)
    319 {
    320 	struct ncr53c9x_linfo *li, *nextli;
    321 	int t;
    322 	int error;
    323 
    324 	callout_stop(&sc->sc_watchdog);
    325 
    326 	if (sc->sc_tinfo) {
    327 		/* Cancel all commands. */
    328 		ncr53c9x_clear(sc, XS_DRIVER_STUFFUP);
    329 
    330 		/* Free logical units. */
    331 		for (t = 0; t < sc->sc_ntarg; t++) {
    332 			for (li = LIST_FIRST(&sc->sc_tinfo[t].luns); li;
    333 			    li = nextli) {
    334 				nextli = LIST_NEXT(li, link);
    335 				free(li, M_DEVBUF);
    336 			}
    337 		}
    338 	}
    339 
    340 	if (sc->sc_child) {
    341 		error = config_detach(sc->sc_child, flags);
    342 		if (error)
    343 			return error;
    344 	}
    345 
    346 	if (sc->sc_imess)
    347 		free(sc->sc_imess, M_DEVBUF);
    348 	if (sc->sc_omess)
    349 		free(sc->sc_omess, M_DEVBUF);
    350 
    351 	return 0;
    352 }
    353 
    354 /*
    355  * This is the generic ncr53c9x reset function. It does not reset the SCSI bus,
    356  * only this controller, but kills any on-going commands, and also stops
    357  * and resets the DMA.
    358  *
    359  * After reset, registers are loaded with the defaults from the attach
    360  * routine above.
    361  */
    362 void
    363 ncr53c9x_reset(struct ncr53c9x_softc *sc)
    364 {
    365 
    366 	/* reset DMA first */
    367 	NCRDMA_RESET(sc);
    368 
    369 	/* reset SCSI chip */
    370 	NCRCMD(sc, NCRCMD_RSTCHIP);
    371 	NCRCMD(sc, NCRCMD_NOP);
    372 	DELAY(500);
    373 
    374 	/* do these backwards, and fall through */
    375 	switch (sc->sc_rev) {
    376 	case NCR_VARIANT_ESP406:
    377 	case NCR_VARIANT_FAS408:
    378 		NCR_WRITE_REG(sc, NCR_CFG5, sc->sc_cfg5 | NCRCFG5_SINT);
    379 		NCR_WRITE_REG(sc, NCR_CFG4, sc->sc_cfg4);
    380 	case NCR_VARIANT_AM53C974:
    381 	case NCR_VARIANT_FAS216:
    382 	case NCR_VARIANT_NCR53C94:
    383 	case NCR_VARIANT_NCR53C96:
    384 	case NCR_VARIANT_ESP200:
    385 		sc->sc_features |= NCR_F_HASCFG3;
    386 		NCR_WRITE_REG(sc, NCR_CFG3, sc->sc_cfg3);
    387 	case NCR_VARIANT_ESP100A:
    388 		sc->sc_features |= NCR_F_SELATN3;
    389 		NCR_WRITE_REG(sc, NCR_CFG2, sc->sc_cfg2);
    390 	case NCR_VARIANT_ESP100:
    391 		NCR_WRITE_REG(sc, NCR_CFG1, sc->sc_cfg1);
    392 		NCR_WRITE_REG(sc, NCR_CCF, sc->sc_ccf);
    393 		NCR_WRITE_REG(sc, NCR_SYNCOFF, 0);
    394 		NCR_WRITE_REG(sc, NCR_TIMEOUT, sc->sc_timeout);
    395 		break;
    396 
    397 	case NCR_VARIANT_FAS366:
    398 		sc->sc_features |=
    399 		    NCR_F_HASCFG3 | NCR_F_FASTSCSI | NCR_F_SELATN3;
    400 		sc->sc_cfg3 = NCRFASCFG3_FASTCLK | NCRFASCFG3_OBAUTO;
    401 		sc->sc_cfg3_fscsi = NCRFASCFG3_FASTSCSI;
    402 		NCR_WRITE_REG(sc, NCR_CFG3, sc->sc_cfg3);
    403 		sc->sc_cfg2 = 0; /* NCRCFG2_HMEFE| NCRCFG2_HME32 */
    404 		NCR_WRITE_REG(sc, NCR_CFG2, sc->sc_cfg2);
    405 		NCR_WRITE_REG(sc, NCR_CFG1, sc->sc_cfg1);
    406 		NCR_WRITE_REG(sc, NCR_CCF, sc->sc_ccf);
    407 		NCR_WRITE_REG(sc, NCR_SYNCOFF, 0);
    408 		NCR_WRITE_REG(sc, NCR_TIMEOUT, sc->sc_timeout);
    409 		break;
    410 
    411 	default:
    412 		printf("%s: unknown revision code, assuming ESP100\n",
    413 		    sc->sc_dev.dv_xname);
    414 		NCR_WRITE_REG(sc, NCR_CFG1, sc->sc_cfg1);
    415 		NCR_WRITE_REG(sc, NCR_CCF, sc->sc_ccf);
    416 		NCR_WRITE_REG(sc, NCR_SYNCOFF, 0);
    417 		NCR_WRITE_REG(sc, NCR_TIMEOUT, sc->sc_timeout);
    418 	}
    419 
    420 	if (sc->sc_rev == NCR_VARIANT_AM53C974)
    421 		NCR_WRITE_REG(sc, NCR_AMDCFG4, sc->sc_cfg4);
    422 
    423 #if 0
    424 	printf("%s: ncr53c9x_reset: revision %d\n",
    425 	       sc->sc_dev.dv_xname, sc->sc_rev);
    426 	printf("%s: ncr53c9x_reset: cfg1 0x%x, cfg2 0x%x, cfg3 0x%x, "
    427 	    "ccf 0x%x, timeout 0x%x\n",
    428 	    sc->sc_dev.dv_xname, sc->sc_cfg1, sc->sc_cfg2, sc->sc_cfg3,
    429 	    sc->sc_ccf, sc->sc_timeout);
    430 #endif
    431 }
    432 
    433 /*
    434  * Reset the SCSI bus, but not the chip
    435  */
    436 void
    437 ncr53c9x_scsi_reset(struct ncr53c9x_softc *sc)
    438 {
    439 
    440 	(*sc->sc_glue->gl_dma_stop)(sc);
    441 
    442 	printf("%s: resetting SCSI bus\n", sc->sc_dev.dv_xname);
    443 	NCRCMD(sc, NCRCMD_RSTSCSI);
    444 }
    445 
    446 /*
    447  * Clear all commands
    448  */
    449 void
    450 ncr53c9x_clear(struct ncr53c9x_softc *sc, scsipi_xfer_result_t result)
    451 {
    452 	struct ncr53c9x_ecb *ecb;
    453 	struct ncr53c9x_linfo *li;
    454 	int i, r;
    455 
    456 	/* Cancel any active commands. */
    457 	sc->sc_state = NCR_CLEANING;
    458 	sc->sc_msgify = 0;
    459 	if ((ecb = sc->sc_nexus) != NULL) {
    460 		ecb->xs->error = result;
    461 		ncr53c9x_done(sc, ecb);
    462 	}
    463 	/* Cancel outstanding disconnected commands on each LUN */
    464 	for (r = 0; r < sc->sc_ntarg; r++) {
    465 		LIST_FOREACH(li, &sc->sc_tinfo[r].luns, link) {
    466 			if ((ecb = li->untagged) != NULL) {
    467 				li->untagged = NULL;
    468 				/*
    469 				 * XXXXXXX
    470 				 *
    471 				 * Should we terminate a command
    472 				 * that never reached the disk?
    473 				 */
    474 				li->busy = 0;
    475 				ecb->xs->error = result;
    476 				ncr53c9x_done(sc, ecb);
    477 			}
    478 			for (i = 0; i < 256; i++)
    479 				if ((ecb = li->queued[i])) {
    480 					li->queued[i] = NULL;
    481 					ecb->xs->error = result;
    482 					ncr53c9x_done(sc, ecb);
    483 				}
    484 			li->used = 0;
    485 		}
    486 	}
    487 }
    488 
    489 /*
    490  * Initialize ncr53c9x state machine
    491  */
    492 void
    493 ncr53c9x_init(struct ncr53c9x_softc *sc, int doreset)
    494 {
    495 	int r;
    496 
    497 	NCR_MISC(("[NCR_INIT(%d) %d] ", doreset, sc->sc_state));
    498 
    499 	if (!ecb_pool_initialized) {
    500 		/* All instances share this pool */
    501 		pool_init(&ecb_pool, sizeof(struct ncr53c9x_ecb), 0, 0, 0,
    502 		    "ncr53c9x_ecb", NULL, IPL_BIO);
    503 		/* make sure to always have some items to play with */
    504 		if (pool_prime(&ecb_pool, 1) == ENOMEM) {
    505 			printf("WARNING: not enough memory for ncr53c9x_ecb\n");
    506 		}
    507 		ecb_pool_initialized = 1;
    508 	}
    509 
    510 	if (sc->sc_state == 0) {
    511 		/* First time through; initialize. */
    512 
    513 		TAILQ_INIT(&sc->ready_list);
    514 		sc->sc_nexus = NULL;
    515 		memset(sc->sc_tinfo, 0, sizeof(sc->sc_tinfo));
    516 		for (r = 0; r < sc->sc_ntarg; r++) {
    517 			LIST_INIT(&sc->sc_tinfo[r].luns);
    518 		}
    519 	} else {
    520 		ncr53c9x_clear(sc, XS_TIMEOUT);
    521 	}
    522 
    523 	/*
    524 	 * reset the chip to a known state
    525 	 */
    526 	ncr53c9x_reset(sc);
    527 
    528 	sc->sc_flags = 0;
    529 	sc->sc_msgpriq = sc->sc_msgout = sc->sc_msgoutq = 0;
    530 	sc->sc_phase = sc->sc_prevphase = INVALID_PHASE;
    531 
    532 	for (r = 0; r < sc->sc_ntarg; r++) {
    533 		struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[r];
    534 /* XXX - config flags per target: low bits: no reselect; high bits: no synch */
    535 
    536 		ti->flags = ((sc->sc_minsync &&
    537 		    !(sc->sc_cfflags & (1 << ((r & 7) + 8)))) ?
    538 		    0 : T_SYNCHOFF) |
    539 		    ((sc->sc_cfflags & (1 << (r & 7))) ? T_RSELECTOFF : 0);
    540 #ifdef DEBUG
    541 		if (ncr53c9x_notag)
    542 			ti->flags &= ~T_TAG;
    543 #endif
    544 		ti->period = sc->sc_minsync;
    545 		ti->offset = 0;
    546 		ti->cfg3   = 0;
    547 
    548 		ncr53c9x_update_xfer_mode(sc, r);
    549 	}
    550 
    551 	if (doreset) {
    552 		sc->sc_state = NCR_SBR;
    553 		NCRCMD(sc, NCRCMD_RSTSCSI);
    554 	} else {
    555 		sc->sc_state = NCR_IDLE;
    556 		ncr53c9x_sched(sc);
    557 	}
    558 
    559 	/* Notify upper layer */
    560 	scsipi_async_event(&sc->sc_channel, ASYNC_EVENT_RESET, NULL);
    561 }
    562 
    563 /*
    564  * Read the NCR registers, and save their contents for later use.
    565  * NCR_STAT, NCR_STEP & NCR_INTR are mostly zeroed out when reading
    566  * NCR_INTR - so make sure it is the last read.
    567  *
    568  * I think that (from reading the docs) most bits in these registers
    569  * only make sense when he DMA CSR has an interrupt showing. Call only
    570  * if an interrupt is pending.
    571  */
    572 inline void
    573 ncr53c9x_readregs(struct ncr53c9x_softc *sc)
    574 {
    575 
    576 	sc->sc_espstat = NCR_READ_REG(sc, NCR_STAT);
    577 	/* Only the stepo bits are of interest */
    578 	sc->sc_espstep = NCR_READ_REG(sc, NCR_STEP) & NCRSTEP_MASK;
    579 
    580 	if (sc->sc_rev == NCR_VARIANT_FAS366)
    581 		sc->sc_espstat2 = NCR_READ_REG(sc, NCR_STAT2);
    582 
    583 	sc->sc_espintr = NCR_READ_REG(sc, NCR_INTR);
    584 
    585 	if (sc->sc_glue->gl_clear_latched_intr != NULL)
    586 		(*sc->sc_glue->gl_clear_latched_intr)(sc);
    587 
    588 	/*
    589 	 * Determine the SCSI bus phase, return either a real SCSI bus phase
    590 	 * or some pseudo phase we use to detect certain exceptions.
    591 	 */
    592 
    593 	sc->sc_phase = (sc->sc_espintr & NCRINTR_DIS) ?
    594 	    /* Disconnected */ BUSFREE_PHASE : sc->sc_espstat & NCRSTAT_PHASE;
    595 
    596 	NCR_INTS(("regs[intr=%02x,stat=%02x,step=%02x,stat2=%02x] ",
    597 	    sc->sc_espintr, sc->sc_espstat, sc->sc_espstep, sc->sc_espstat2));
    598 }
    599 
    600 /*
    601  * Convert Synchronous Transfer Period to chip register Clock Per Byte value.
    602  */
    603 static inline int
    604 ncr53c9x_stp2cpb(struct ncr53c9x_softc *sc, int period)
    605 {
    606 	int v;
    607 
    608 	v = (sc->sc_freq * period) / 250;
    609 	if (ncr53c9x_cpb2stp(sc, v) < period)
    610 		/* Correct round-down error */
    611 		v++;
    612 	return v;
    613 }
    614 
    615 static inline void
    616 ncr53c9x_setsync(struct ncr53c9x_softc *sc, struct ncr53c9x_tinfo *ti)
    617 {
    618 	u_char syncoff, synctp;
    619 	u_char cfg3 = sc->sc_cfg3 | ti->cfg3;
    620 
    621 	if (ti->flags & T_SYNCMODE) {
    622 		syncoff = ti->offset;
    623 		synctp = ncr53c9x_stp2cpb(sc, ti->period);
    624 		if (sc->sc_features & NCR_F_FASTSCSI) {
    625 			/*
    626 			 * If the period is 200ns or less (ti->period <= 50),
    627 			 * put the chip in Fast SCSI mode.
    628 			 */
    629 			if (ti->period <= 50)
    630 				/*
    631 				 * There are (at least) 4 variations of the
    632 				 * configuration 3 register.  The drive attach
    633 				 * routine sets the appropriate bit to put the
    634 				 * chip into Fast SCSI mode so that it doesn't
    635 				 * have to be figured out here each time.
    636 				 */
    637 				cfg3 |= sc->sc_cfg3_fscsi;
    638 		}
    639 
    640 		/*
    641 		 * Am53c974 requires different SYNCTP values when the
    642 		 * FSCSI bit is off.
    643 		 */
    644 		if (sc->sc_rev == NCR_VARIANT_AM53C974 &&
    645 		    (cfg3 & NCRAMDCFG3_FSCSI) == 0)
    646 			synctp--;
    647 	} else {
    648 		syncoff = 0;
    649 		synctp = 0;
    650 	}
    651 
    652 	if (sc->sc_features & NCR_F_HASCFG3)
    653 		NCR_WRITE_REG(sc, NCR_CFG3, cfg3);
    654 
    655 	NCR_WRITE_REG(sc, NCR_SYNCOFF, syncoff);
    656 	NCR_WRITE_REG(sc, NCR_SYNCTP, synctp);
    657 }
    658 
    659 /*
    660  * Send a command to a target, set the driver state to NCR_SELECTING
    661  * and let the caller take care of the rest.
    662  *
    663  * Keeping this as a function allows me to say that this may be done
    664  * by DMA instead of programmed I/O soon.
    665  */
    666 void
    667 ncr53c9x_select(struct ncr53c9x_softc *sc, struct ncr53c9x_ecb *ecb)
    668 {
    669 	struct scsipi_periph *periph = ecb->xs->xs_periph;
    670 	int target = periph->periph_target;
    671 	int lun = periph->periph_lun;
    672 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[target];
    673 	int tiflags = ti->flags;
    674 	u_char *cmd;
    675 	int clen;
    676 	int selatn3, selatns;
    677 	size_t dmasize;
    678 
    679 	NCR_TRACE(("[ncr53c9x_select(t%d,l%d,cmd:%x,tag:%x,%x)] ",
    680 	    target, lun, ecb->cmd.cmd.opcode, ecb->tag[0], ecb->tag[1]));
    681 
    682 	sc->sc_state = NCR_SELECTING;
    683 	/*
    684 	 * Schedule the timeout now, the first time we will go away
    685 	 * expecting to come back due to an interrupt, because it is
    686 	 * always possible that the interrupt may never happen.
    687 	 */
    688 	if ((ecb->xs->xs_control & XS_CTL_POLL) == 0) {
    689 		callout_reset(&ecb->xs->xs_callout, mstohz(ecb->timeout),
    690 		    ncr53c9x_timeout, ecb);
    691 	}
    692 
    693 	/*
    694 	 * The docs say the target register is never reset, and I
    695 	 * can't think of a better place to set it
    696 	 */
    697 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
    698 		NCRCMD(sc, NCRCMD_FLUSH);
    699 		NCR_WRITE_REG(sc, NCR_SELID, target | NCR_BUSID_HME);
    700 	} else {
    701 		NCR_WRITE_REG(sc, NCR_SELID, target);
    702 	}
    703 	ncr53c9x_setsync(sc, ti);
    704 
    705 	if ((ecb->flags & ECB_SENSE) != 0) {
    706 		/*
    707 		 * For REQUEST SENSE, we should not send an IDENTIFY or
    708 		 * otherwise mangle the target.  There should be no MESSAGE IN
    709 		 * phase.
    710 		 */
    711 		if (sc->sc_features & NCR_F_DMASELECT) {
    712 			/* setup DMA transfer for command */
    713 			dmasize = clen = ecb->clen;
    714 			sc->sc_cmdlen = clen;
    715 			sc->sc_cmdp = (void *)&ecb->cmd.cmd;
    716 
    717 			NCRDMA_SETUP(sc, &sc->sc_cmdp, &sc->sc_cmdlen, 0,
    718 			    &dmasize);
    719 			/* Program the SCSI counter */
    720 			NCR_SET_COUNT(sc, dmasize);
    721 
    722 			if (sc->sc_rev != NCR_VARIANT_FAS366)
    723 				NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
    724 
    725 			/* And get the targets attention */
    726 			NCRCMD(sc, NCRCMD_SELNATN | NCRCMD_DMA);
    727 			NCRDMA_GO(sc);
    728 		} else {
    729 			ncr53c9x_wrfifo(sc, (u_char *)&ecb->cmd.cmd, ecb->clen);
    730 			NCRCMD(sc, NCRCMD_SELNATN);
    731 		}
    732 		return;
    733 	}
    734 
    735 	selatn3 = selatns = 0;
    736 	if (ecb->tag[0] != 0) {
    737 		if (sc->sc_features & NCR_F_SELATN3)
    738 			/* use SELATN3 to send tag messages */
    739 			selatn3 = 1;
    740 		else
    741 			/* We don't have SELATN3; use SELATNS to send tags */
    742 			selatns = 1;
    743 	}
    744 
    745 	if (ti->flags & T_NEGOTIATE) {
    746 		/* We have to use SELATNS to send sync/wide messages */
    747 		selatn3 = 0;
    748 		selatns = 1;
    749 	}
    750 
    751 	cmd = (u_char *)&ecb->cmd.cmd;
    752 
    753 	if (selatn3) {
    754 		/* We'll use tags with SELATN3 */
    755 		clen = ecb->clen + 3;
    756 		cmd -= 3;
    757 		cmd[0] = MSG_IDENTIFY(lun, 1);	/* msg[0] */
    758 		cmd[1] = ecb->tag[0];		/* msg[1] */
    759 		cmd[2] = ecb->tag[1];		/* msg[2] */
    760 	} else {
    761 		/* We don't have tags, or will send messages with SELATNS */
    762 		clen = ecb->clen + 1;
    763 		cmd -= 1;
    764 		cmd[0] = MSG_IDENTIFY(lun, (tiflags & T_RSELECTOFF) == 0);
    765 	}
    766 
    767 	if ((sc->sc_features & NCR_F_DMASELECT) && !selatns) {
    768 
    769 		/* setup DMA transfer for command */
    770 		dmasize = clen;
    771 		sc->sc_cmdlen = clen;
    772 		sc->sc_cmdp = cmd;
    773 
    774 		NCRDMA_SETUP(sc, &sc->sc_cmdp, &sc->sc_cmdlen, 0, &dmasize);
    775 		/* Program the SCSI counter */
    776 		NCR_SET_COUNT(sc, dmasize);
    777 
    778 		/* load the count in */
    779 		/* if (sc->sc_rev != NCR_VARIANT_FAS366) */
    780 			NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
    781 
    782 		/* And get the targets attention */
    783 		if (selatn3) {
    784 			sc->sc_msgout = SEND_TAG;
    785 			sc->sc_flags |= NCR_ATN;
    786 			NCRCMD(sc, NCRCMD_SELATN3 | NCRCMD_DMA);
    787 		} else
    788 			NCRCMD(sc, NCRCMD_SELATN | NCRCMD_DMA);
    789 		NCRDMA_GO(sc);
    790 		return;
    791 	}
    792 
    793 	/*
    794 	 * Who am I. This is where we tell the target that we are
    795 	 * happy for it to disconnect etc.
    796 	 */
    797 
    798 	/* Now get the command into the FIFO */
    799 	ncr53c9x_wrfifo(sc, cmd, clen);
    800 
    801 	/* And get the targets attention */
    802 	if (selatns) {
    803 		NCR_MSGS(("SELATNS \n"));
    804 		/* Arbitrate, select and stop after IDENTIFY message */
    805 		NCRCMD(sc, NCRCMD_SELATNS);
    806 	} else if (selatn3) {
    807 		sc->sc_msgout = SEND_TAG;
    808 		sc->sc_flags |= NCR_ATN;
    809 		NCRCMD(sc, NCRCMD_SELATN3);
    810 	} else
    811 		NCRCMD(sc, NCRCMD_SELATN);
    812 }
    813 
    814 void
    815 ncr53c9x_free_ecb(struct ncr53c9x_softc *sc, struct ncr53c9x_ecb *ecb)
    816 {
    817 	int s;
    818 
    819 	s = splbio();
    820 	ecb->flags = 0;
    821 	pool_put(&ecb_pool, (void *)ecb);
    822 	splx(s);
    823 	return;
    824 }
    825 
    826 struct ncr53c9x_ecb *
    827 ncr53c9x_get_ecb(struct ncr53c9x_softc *sc, int flags)
    828 {
    829 	struct ncr53c9x_ecb *ecb;
    830 	int s;
    831 
    832 	s = splbio();
    833 	ecb = (struct ncr53c9x_ecb *)pool_get(&ecb_pool, PR_NOWAIT);
    834 	splx(s);
    835 	if (ecb) {
    836 		memset(ecb, 0, sizeof(*ecb));
    837 		ecb->flags |= ECB_ALLOC;
    838 	}
    839 	return ecb;
    840 }
    841 
    842 /*
    843  * DRIVER FUNCTIONS CALLABLE FROM HIGHER LEVEL DRIVERS
    844  */
    845 
    846 /*
    847  * Start a SCSI-command
    848  * This function is called by the higher level SCSI-driver to queue/run
    849  * SCSI-commands.
    850  */
    851 
    852 void
    853 ncr53c9x_scsipi_request(struct scsipi_channel *chan, scsipi_adapter_req_t req,
    854     void *arg)
    855 {
    856 	struct scsipi_xfer *xs;
    857 	struct scsipi_periph *periph;
    858 	struct ncr53c9x_softc *sc = (void *)chan->chan_adapter->adapt_dev;
    859 	struct ncr53c9x_ecb *ecb;
    860 	int s, flags;
    861 
    862 	NCR_TRACE(("[ncr53c9x_scsipi_request] "));
    863 
    864 	s = splbio();
    865 	simple_lock(&sc->sc_lock);
    866 
    867 	switch (req) {
    868 	case ADAPTER_REQ_RUN_XFER:
    869 		xs = arg;
    870 		periph = xs->xs_periph;
    871 		flags = xs->xs_control;
    872 
    873 		NCR_CMDS(("[0x%x, %d]->%d ", (int)xs->cmd->opcode, xs->cmdlen,
    874 		    periph->periph_target));
    875 
    876 		/* Get an ECB to use. */
    877 		ecb = ncr53c9x_get_ecb(sc, xs->xs_control);
    878 		/*
    879 		 * This should never happen as we track resources
    880 		 * in the mid-layer, but for now it can as pool_get()
    881 		 * can fail.
    882 		 */
    883 		if (ecb == NULL) {
    884 			scsipi_printaddr(periph);
    885 			printf("unable to allocate ecb\n");
    886 			xs->error = XS_RESOURCE_SHORTAGE;
    887 			simple_unlock(&sc->sc_lock);
    888 			splx(s);
    889 			scsipi_done(xs);
    890 			return;
    891 		}
    892 
    893 		/* Initialize ecb */
    894 		ecb->xs = xs;
    895 		ecb->timeout = xs->timeout;
    896 
    897 		if (flags & XS_CTL_RESET) {
    898 			ecb->flags |= ECB_RESET;
    899 			ecb->clen = 0;
    900 			ecb->dleft = 0;
    901 		} else {
    902 			memcpy(&ecb->cmd.cmd, xs->cmd, xs->cmdlen);
    903 			ecb->clen = xs->cmdlen;
    904 			ecb->daddr = xs->data;
    905 			ecb->dleft = xs->datalen;
    906 		}
    907 		ecb->stat = 0;
    908 
    909 		TAILQ_INSERT_TAIL(&sc->ready_list, ecb, chain);
    910 		ecb->flags |= ECB_READY;
    911 		if (sc->sc_state == NCR_IDLE)
    912 			ncr53c9x_sched(sc);
    913 
    914 		if ((flags & XS_CTL_POLL) == 0)
    915 			break;
    916 
    917 		/* Not allowed to use interrupts, use polling instead */
    918 		if (ncr53c9x_poll(sc, xs, ecb->timeout)) {
    919 			ncr53c9x_timeout(ecb);
    920 			if (ncr53c9x_poll(sc, xs, ecb->timeout))
    921 				ncr53c9x_timeout(ecb);
    922 		}
    923 		break;
    924 
    925 	case ADAPTER_REQ_GROW_RESOURCES:
    926 		/* XXX Not supported. */
    927 		break;
    928 
    929 	case ADAPTER_REQ_SET_XFER_MODE:
    930 	    {
    931 		struct ncr53c9x_tinfo *ti;
    932 		struct scsipi_xfer_mode *xm = arg;
    933 
    934 		ti = &sc->sc_tinfo[xm->xm_target];
    935 		ti->flags &= ~(T_NEGOTIATE|T_SYNCMODE);
    936 		ti->period = 0;
    937 		ti->offset = 0;
    938 
    939 		if ((sc->sc_cfflags & (1 << ((xm->xm_target & 7) + 16))) == 0 &&
    940 		    (xm->xm_mode & PERIPH_CAP_TQING)) {
    941 			NCR_MISC(("%s: target %d: tagged queuing\n",
    942 			    sc->sc_dev.dv_xname, xm->xm_target));
    943 			ti->flags |= T_TAG;
    944 		} else
    945 			ti->flags &= ~T_TAG;
    946 
    947 		if ((xm->xm_mode & PERIPH_CAP_WIDE16) != 0) {
    948 			NCR_MISC(("%s: target %d: wide scsi negotiation\n",
    949 			    sc->sc_dev.dv_xname, xm->xm_target));
    950 			if (sc->sc_rev == NCR_VARIANT_FAS366) {
    951 				ti->flags |= T_WIDE;
    952 				ti->width = 1;
    953 			}
    954 		}
    955 
    956 		if ((xm->xm_mode & PERIPH_CAP_SYNC) != 0 &&
    957 		    (ti->flags & T_SYNCHOFF) == 0 && sc->sc_minsync != 0) {
    958 			NCR_MISC(("%s: target %d: sync negotiation\n",
    959 			    sc->sc_dev.dv_xname, xm->xm_target));
    960 			ti->flags |= T_NEGOTIATE;
    961 			ti->period = sc->sc_minsync;
    962 		}
    963 		/*
    964 		 * If we're not going to negotiate, send the notification
    965 		 * now, since it won't happen later.
    966 		 */
    967 		if ((ti->flags & T_NEGOTIATE) == 0)
    968 			ncr53c9x_update_xfer_mode(sc, xm->xm_target);
    969 	    }
    970 		break;
    971 	}
    972 
    973 	simple_unlock(&sc->sc_lock);
    974 	splx(s);
    975 }
    976 
    977 void
    978 ncr53c9x_update_xfer_mode(struct ncr53c9x_softc *sc, int target)
    979 {
    980 	struct scsipi_xfer_mode xm;
    981 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[target];
    982 
    983 	xm.xm_target = target;
    984 	xm.xm_mode = 0;
    985 	xm.xm_period = 0;
    986 	xm.xm_offset = 0;
    987 
    988 	if (ti->flags & T_SYNCMODE) {
    989 		xm.xm_mode |= PERIPH_CAP_SYNC;
    990 		xm.xm_period = ti->period;
    991 		xm.xm_offset = ti->offset;
    992 	}
    993 	if (ti->width)
    994 		xm.xm_mode |= PERIPH_CAP_WIDE16;
    995 
    996 	if ((ti->flags & (T_RSELECTOFF|T_TAG)) == T_TAG)
    997 		xm.xm_mode |= PERIPH_CAP_TQING;
    998 
    999 	scsipi_async_event(&sc->sc_channel, ASYNC_EVENT_XFER_MODE, &xm);
   1000 }
   1001 
   1002 /*
   1003  * Used when interrupt driven I/O isn't allowed, e.g. during boot.
   1004  */
   1005 int
   1006 ncr53c9x_poll(struct ncr53c9x_softc *sc, struct scsipi_xfer *xs, int count)
   1007 {
   1008 
   1009 	NCR_TRACE(("[ncr53c9x_poll] "));
   1010 	while (count) {
   1011 		if (NCRDMA_ISINTR(sc)) {
   1012 			simple_unlock(&sc->sc_lock);
   1013 			ncr53c9x_intr(sc);
   1014 			simple_lock(&sc->sc_lock);
   1015 		}
   1016 #if alternatively
   1017 		if (NCR_READ_REG(sc, NCR_STAT) & NCRSTAT_INT)
   1018 			ncr53c9x_intr(sc);
   1019 #endif
   1020 		if ((xs->xs_status & XS_STS_DONE) != 0)
   1021 			return 0;
   1022 		if (sc->sc_state == NCR_IDLE) {
   1023 			NCR_TRACE(("[ncr53c9x_poll: rescheduling] "));
   1024 			ncr53c9x_sched(sc);
   1025 		}
   1026 		DELAY(1000);
   1027 		count--;
   1028 	}
   1029 	return 1;
   1030 }
   1031 
   1032 int
   1033 ncr53c9x_ioctl(struct scsipi_channel *chan, u_long cmd, void *arg,
   1034     int flag, struct proc *p)
   1035 {
   1036 	struct ncr53c9x_softc *sc = (void *)chan->chan_adapter->adapt_dev;
   1037 	int s, error = 0;
   1038 
   1039 	switch (cmd) {
   1040 	case SCBUSIORESET:
   1041 		s = splbio();
   1042 		simple_lock(&sc->sc_lock);
   1043 		ncr53c9x_init(sc, 1);
   1044 		simple_unlock(&sc->sc_lock);
   1045 		splx(s);
   1046 		break;
   1047 	default:
   1048 		error = ENOTTY;
   1049 		break;
   1050 	}
   1051 	return error;
   1052 }
   1053 
   1054 
   1055 /*
   1056  * LOW LEVEL SCSI UTILITIES
   1057  */
   1058 
   1059 /*
   1060  * Schedule a scsi operation.  This has now been pulled out of the interrupt
   1061  * handler so that we may call it from ncr53c9x_scsipi_request and
   1062  * ncr53c9x_done.  This may save us an unnecessary interrupt just to get
   1063  * things going.  Should only be called when state == NCR_IDLE and at bio pl.
   1064  */
   1065 void
   1066 ncr53c9x_sched(struct ncr53c9x_softc *sc)
   1067 {
   1068 	struct ncr53c9x_ecb *ecb;
   1069 	struct scsipi_periph *periph;
   1070 	struct ncr53c9x_tinfo *ti;
   1071 	struct ncr53c9x_linfo *li;
   1072 	int lun;
   1073 	int tag;
   1074 
   1075 	NCR_TRACE(("[ncr53c9x_sched] "));
   1076 	if (sc->sc_state != NCR_IDLE)
   1077 		panic("ncr53c9x_sched: not IDLE (state=%d)", sc->sc_state);
   1078 
   1079 	/*
   1080 	 * Find first ecb in ready queue that is for a target/lunit
   1081 	 * combinations that is not busy.
   1082 	 */
   1083 	for (ecb = TAILQ_FIRST(&sc->ready_list); ecb != NULL;
   1084 	    ecb = TAILQ_NEXT(ecb, chain)) {
   1085 		periph = ecb->xs->xs_periph;
   1086 		ti = &sc->sc_tinfo[periph->periph_target];
   1087 		lun = periph->periph_lun;
   1088 
   1089 		/* Select type of tag for this command */
   1090 		if ((ti->flags & (T_RSELECTOFF)) != 0)
   1091 			tag = 0;
   1092 		else if ((ti->flags & (T_TAG)) == 0)
   1093 			tag = 0;
   1094 		else if ((ecb->flags & ECB_SENSE) != 0)
   1095 			tag = 0;
   1096 		else
   1097 			tag = ecb->xs->xs_tag_type;
   1098 #if 0
   1099 		/* XXXX Use tags for polled commands? */
   1100 		if (ecb->xs->xs_control & XS_CTL_POLL)
   1101 			tag = 0;
   1102 #endif
   1103 
   1104 		li = TINFO_LUN(ti, lun);
   1105 		if (li == NULL) {
   1106 			/* Initialize LUN info and add to list. */
   1107 			if ((li = malloc(sizeof(*li),
   1108 			    M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL) {
   1109 				continue;
   1110 			}
   1111 			li->lun = lun;
   1112 
   1113 			LIST_INSERT_HEAD(&ti->luns, li, link);
   1114 			if (lun < NCR_NLUN)
   1115 				ti->lun[lun] = li;
   1116 		}
   1117 		li->last_used = time_second;
   1118 		if (tag == 0) {
   1119 			/* Try to issue this as an un-tagged command */
   1120 			if (li->untagged == NULL)
   1121 				li->untagged = ecb;
   1122 		}
   1123 		if (li->untagged != NULL) {
   1124 			tag = 0;
   1125 			if ((li->busy != 1) && li->used == 0) {
   1126 				/* We need to issue this untagged command now */
   1127 				ecb = li->untagged;
   1128 				periph = ecb->xs->xs_periph;
   1129 			} else {
   1130 				/* Not ready yet */
   1131 				continue;
   1132 			}
   1133 		}
   1134 		ecb->tag[0] = tag;
   1135 		if (tag != 0) {
   1136 			li->queued[ecb->xs->xs_tag_id] = ecb;
   1137 			ecb->tag[1] = ecb->xs->xs_tag_id;
   1138 			li->used++;
   1139 		}
   1140 		if (li->untagged != NULL && (li->busy != 1)) {
   1141 			li->busy = 1;
   1142 			TAILQ_REMOVE(&sc->ready_list, ecb, chain);
   1143 			ecb->flags &= ~ECB_READY;
   1144 			sc->sc_nexus = ecb;
   1145 			ncr53c9x_select(sc, ecb);
   1146 			break;
   1147 		}
   1148 		if (li->untagged == NULL && tag != 0) {
   1149 			TAILQ_REMOVE(&sc->ready_list, ecb, chain);
   1150 			ecb->flags &= ~ECB_READY;
   1151 			sc->sc_nexus = ecb;
   1152 			ncr53c9x_select(sc, ecb);
   1153 			break;
   1154 		} else {
   1155 			NCR_TRACE(("%d:%d busy\n",
   1156 			    periph->periph_target,
   1157 			    periph->periph_lun));
   1158 		}
   1159 	}
   1160 }
   1161 
   1162 void
   1163 ncr53c9x_sense(struct ncr53c9x_softc *sc, struct ncr53c9x_ecb *ecb)
   1164 {
   1165 	struct scsipi_xfer *xs = ecb->xs;
   1166 	struct scsipi_periph *periph = xs->xs_periph;
   1167 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[periph->periph_target];
   1168 	struct scsi_request_sense *ss = (void *)&ecb->cmd.cmd;
   1169 	struct ncr53c9x_linfo *li;
   1170 	int lun = periph->periph_lun;
   1171 
   1172 	NCR_TRACE(("requesting sense "));
   1173 	/* Next, setup a request sense command block */
   1174 	memset(ss, 0, sizeof(*ss));
   1175 	ss->opcode = SCSI_REQUEST_SENSE;
   1176 	ss->byte2 = periph->periph_lun << SCSI_CMD_LUN_SHIFT;
   1177 	ss->length = sizeof(struct scsi_sense_data);
   1178 	ecb->clen = sizeof(*ss);
   1179 	ecb->daddr = (char *)&xs->sense.scsi_sense;
   1180 	ecb->dleft = sizeof(struct scsi_sense_data);
   1181 	ecb->flags |= ECB_SENSE;
   1182 	ecb->timeout = NCR_SENSE_TIMEOUT;
   1183 	ti->senses++;
   1184 	li = TINFO_LUN(ti, lun);
   1185 	if (li->busy)
   1186 		li->busy = 0;
   1187 	ncr53c9x_dequeue(sc, ecb);
   1188 	li->untagged = ecb; /* must be executed first to fix C/A */
   1189 	li->busy = 2;
   1190 	if (ecb == sc->sc_nexus) {
   1191 		ncr53c9x_select(sc, ecb);
   1192 	} else {
   1193 		TAILQ_INSERT_HEAD(&sc->ready_list, ecb, chain);
   1194 		ecb->flags |= ECB_READY;
   1195 		if (sc->sc_state == NCR_IDLE)
   1196 			ncr53c9x_sched(sc);
   1197 	}
   1198 }
   1199 
   1200 /*
   1201  * POST PROCESSING OF SCSI_CMD (usually current)
   1202  */
   1203 void
   1204 ncr53c9x_done(struct ncr53c9x_softc *sc, struct ncr53c9x_ecb *ecb)
   1205 {
   1206 	struct scsipi_xfer *xs = ecb->xs;
   1207 	struct scsipi_periph *periph = xs->xs_periph;
   1208 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[periph->periph_target];
   1209 	int lun = periph->periph_lun;
   1210 	struct ncr53c9x_linfo *li = TINFO_LUN(ti, lun);
   1211 
   1212 	NCR_TRACE(("[ncr53c9x_done(error:%x)] ", xs->error));
   1213 
   1214 	callout_stop(&ecb->xs->xs_callout);
   1215 
   1216 	/*
   1217 	 * Now, if we've come here with no error code, i.e. we've kept the
   1218 	 * initial XS_NOERROR, and the status code signals that we should
   1219 	 * check sense, we'll need to set up a request sense cmd block and
   1220 	 * push the command back into the ready queue *before* any other
   1221 	 * commands for this target/lunit, else we lose the sense info.
   1222 	 * We don't support chk sense conditions for the request sense cmd.
   1223 	 */
   1224 	if (xs->error == XS_NOERROR) {
   1225 		xs->status = ecb->stat;
   1226 		if ((ecb->flags & ECB_ABORT) != 0) {
   1227 			xs->error = XS_TIMEOUT;
   1228 		} else if ((ecb->flags & ECB_SENSE) != 0) {
   1229 			xs->error = XS_SENSE;
   1230 		} else if ((ecb->stat & ST_MASK) == SCSI_CHECK) {
   1231 			/* First, save the return values */
   1232 			xs->resid = ecb->dleft;
   1233 			ncr53c9x_sense(sc, ecb);
   1234 			return;
   1235 		} else {
   1236 			xs->resid = ecb->dleft;
   1237 		}
   1238 		if (xs->status == SCSI_QUEUE_FULL || xs->status == XS_BUSY)
   1239 			xs->error = XS_BUSY;
   1240 	}
   1241 
   1242 #ifdef NCR53C9X_DEBUG
   1243 	if (ncr53c9x_debug & NCR_SHOWTRAC) {
   1244 		if (xs->resid != 0)
   1245 			printf("resid=%d ", xs->resid);
   1246 		if (xs->error == XS_SENSE)
   1247 			printf("sense=0x%02x\n",
   1248 			    xs->sense.scsi_sense.response_code);
   1249 		else
   1250 			printf("error=%d\n", xs->error);
   1251 	}
   1252 #endif
   1253 
   1254 	/*
   1255 	 * Remove the ECB from whatever queue it's on.
   1256 	 */
   1257 	ncr53c9x_dequeue(sc, ecb);
   1258 	if (ecb == sc->sc_nexus) {
   1259 		sc->sc_nexus = NULL;
   1260 		if (sc->sc_state != NCR_CLEANING) {
   1261 			sc->sc_state = NCR_IDLE;
   1262 			ncr53c9x_sched(sc);
   1263 		}
   1264 	}
   1265 
   1266 	if (xs->error == XS_SELTIMEOUT) {
   1267 		/* Selection timeout -- discard this LUN if empty */
   1268 		if (li->untagged == NULL && li->used == 0) {
   1269 			if (lun < NCR_NLUN)
   1270 				ti->lun[lun] = NULL;
   1271 			LIST_REMOVE(li, link);
   1272 			free(li, M_DEVBUF);
   1273 		}
   1274 	}
   1275 
   1276 	ncr53c9x_free_ecb(sc, ecb);
   1277 	ti->cmds++;
   1278 	simple_unlock(&sc->sc_lock);
   1279 	scsipi_done(xs);
   1280 	simple_lock(&sc->sc_lock);
   1281 }
   1282 
   1283 void
   1284 ncr53c9x_dequeue(struct ncr53c9x_softc *sc, struct ncr53c9x_ecb *ecb)
   1285 {
   1286 	struct ncr53c9x_tinfo *ti =
   1287 	    &sc->sc_tinfo[ecb->xs->xs_periph->periph_target];
   1288 	struct ncr53c9x_linfo *li;
   1289 	int64_t lun = ecb->xs->xs_periph->periph_lun;
   1290 
   1291 	li = TINFO_LUN(ti, lun);
   1292 #ifdef DIAGNOSTIC
   1293 	if (li == NULL || li->lun != lun)
   1294 		panic("ncr53c9x_dequeue: lun %qx for ecb %p does not exist",
   1295 		    (long long)lun, ecb);
   1296 #endif
   1297 	if (li->untagged == ecb) {
   1298 		li->busy = 0;
   1299 		li->untagged = NULL;
   1300 	}
   1301 	if (ecb->tag[0] && li->queued[ecb->tag[1]] != NULL) {
   1302 #ifdef DIAGNOSTIC
   1303 		if (li->queued[ecb->tag[1]] != NULL &&
   1304 		    (li->queued[ecb->tag[1]] != ecb))
   1305 			panic("ncr53c9x_dequeue: slot %d for lun %qx has %p "
   1306 			    "instead of ecb %p\n", ecb->tag[1],
   1307 			    (long long)lun,
   1308 			    li->queued[ecb->tag[1]], ecb);
   1309 #endif
   1310 		li->queued[ecb->tag[1]] = NULL;
   1311 		li->used--;
   1312 	}
   1313 
   1314 	if ((ecb->flags & ECB_READY) != 0) {
   1315 		ecb->flags &= ~ECB_READY;
   1316 		TAILQ_REMOVE(&sc->ready_list, ecb, chain);
   1317 	}
   1318 }
   1319 
   1320 /*
   1321  * INTERRUPT/PROTOCOL ENGINE
   1322  */
   1323 
   1324 /*
   1325  * Schedule an outgoing message by prioritizing it, and asserting
   1326  * attention on the bus. We can only do this when we are the initiator
   1327  * else there will be an illegal command interrupt.
   1328  */
   1329 #define ncr53c9x_sched_msgout(m) \
   1330 	do {							\
   1331 		NCR_MSGS(("ncr53c9x_sched_msgout %x %d", m, __LINE__));	\
   1332 		NCRCMD(sc, NCRCMD_SETATN);			\
   1333 		sc->sc_flags |= NCR_ATN;			\
   1334 		sc->sc_msgpriq |= (m);				\
   1335 	} while (/* CONSTCOND */0)
   1336 
   1337 static void
   1338 ncr53c9x_flushfifo(struct ncr53c9x_softc *sc)
   1339 {
   1340 	NCR_TRACE(("[flushfifo] "));
   1341 
   1342 	NCRCMD(sc, NCRCMD_FLUSH);
   1343 
   1344 	if (sc->sc_phase == COMMAND_PHASE ||
   1345 	    sc->sc_phase == MESSAGE_OUT_PHASE)
   1346 		DELAY(2);
   1347 }
   1348 
   1349 static int
   1350 ncr53c9x_rdfifo(struct ncr53c9x_softc *sc, int how)
   1351 {
   1352 	int i, n;
   1353 	u_char *ibuf;
   1354 
   1355 	switch(how) {
   1356 	case NCR_RDFIFO_START:
   1357 		ibuf = sc->sc_imess;
   1358 		sc->sc_imlen = 0;
   1359 		break;
   1360 	case NCR_RDFIFO_CONTINUE:
   1361 		ibuf = sc->sc_imess + sc->sc_imlen;
   1362 		break;
   1363 	default:
   1364 		panic("ncr53c9x_rdfifo: bad flag");
   1365 		break;
   1366 	}
   1367 
   1368 	/*
   1369 	 * XXX buffer (sc_imess) size for message
   1370 	 */
   1371 
   1372 	n = NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF;
   1373 
   1374 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
   1375 		n *= 2;
   1376 
   1377 		for (i = 0; i < n; i++)
   1378 			ibuf[i] = NCR_READ_REG(sc, NCR_FIFO);
   1379 
   1380 		if (sc->sc_espstat2 & NCRFAS_STAT2_ISHUTTLE) {
   1381 
   1382 			NCR_WRITE_REG(sc, NCR_FIFO, 0);
   1383 			ibuf[i++] = NCR_READ_REG(sc, NCR_FIFO);
   1384 
   1385 			NCR_READ_REG(sc, NCR_FIFO);
   1386 
   1387 			ncr53c9x_flushfifo(sc);
   1388 		}
   1389 	} else {
   1390 		for (i = 0; i < n; i++)
   1391 			ibuf[i] = NCR_READ_REG(sc, NCR_FIFO);
   1392 	}
   1393 
   1394 	sc->sc_imlen += i;
   1395 
   1396 #if 0
   1397 #ifdef NCR53C9X_DEBUG
   1398  	{
   1399 		int j;
   1400 
   1401 		NCR_TRACE(("\n[rdfifo %s (%d):",
   1402 		    (how == NCR_RDFIFO_START) ? "start" : "cont",
   1403 		    (int)sc->sc_imlen));
   1404 		if (ncr53c9x_debug & NCR_SHOWTRAC) {
   1405 			for (j = 0; j < sc->sc_imlen; j++)
   1406 				printf(" %02x", sc->sc_imess[j]);
   1407 			printf("]\n");
   1408 		}
   1409 	}
   1410 #endif
   1411 #endif
   1412 	return sc->sc_imlen;
   1413 }
   1414 
   1415 static void
   1416 ncr53c9x_wrfifo(struct ncr53c9x_softc *sc, u_char *p, int len)
   1417 {
   1418 	int i;
   1419 
   1420 #ifdef NCR53C9X_DEBUG
   1421 	NCR_MSGS(("[wrfifo(%d):", len));
   1422 	if (ncr53c9x_debug & NCR_SHOWMSGS) {
   1423 		for (i = 0; i < len; i++)
   1424 			printf(" %02x", p[i]);
   1425 		printf("]\n");
   1426 	}
   1427 #endif
   1428 
   1429 	for (i = 0; i < len; i++) {
   1430 		NCR_WRITE_REG(sc, NCR_FIFO, p[i]);
   1431 
   1432 		if (sc->sc_rev == NCR_VARIANT_FAS366)
   1433 			NCR_WRITE_REG(sc, NCR_FIFO, 0);
   1434 	}
   1435 }
   1436 
   1437 int
   1438 ncr53c9x_reselect(struct ncr53c9x_softc *sc, int message, int tagtype,
   1439     int tagid)
   1440 {
   1441 	u_char selid, target, lun;
   1442 	struct ncr53c9x_ecb *ecb = NULL;
   1443 	struct ncr53c9x_tinfo *ti;
   1444 	struct ncr53c9x_linfo *li;
   1445 
   1446 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
   1447 		target = sc->sc_selid;
   1448 	} else {
   1449 		/*
   1450 		 * The SCSI chip made a snapshot of the data bus
   1451 		 * while the reselection was being negotiated.
   1452 		 * This enables us to determine which target did
   1453 		 * the reselect.
   1454 		 */
   1455 		selid = sc->sc_selid & ~(1 << sc->sc_id);
   1456 		if (selid & (selid - 1)) {
   1457 			printf("%s: reselect with invalid selid %02x;"
   1458 			    " sending DEVICE RESET\n",
   1459 			    sc->sc_dev.dv_xname, selid);
   1460 			goto reset;
   1461 		}
   1462 
   1463 		target = ffs(selid) - 1;
   1464 	}
   1465 	lun = message & 0x07;
   1466 
   1467 	/*
   1468 	 * Search wait queue for disconnected cmd
   1469 	 * The list should be short, so I haven't bothered with
   1470 	 * any more sophisticated structures than a simple
   1471 	 * singly linked list.
   1472 	 */
   1473 	ti = &sc->sc_tinfo[target];
   1474 	li = TINFO_LUN(ti, lun);
   1475 
   1476 	/*
   1477 	 * We can get as far as the LUN with the IDENTIFY
   1478 	 * message.  Check to see if we're running an
   1479 	 * un-tagged command.  Otherwise ack the IDENTIFY
   1480 	 * and wait for a tag message.
   1481 	 */
   1482 	if (li != NULL) {
   1483 		if (li->untagged != NULL && li->busy)
   1484 			ecb = li->untagged;
   1485 		else if (tagtype != MSG_SIMPLE_Q_TAG) {
   1486 			/* Wait for tag to come by */
   1487 			sc->sc_state = NCR_IDENTIFIED;
   1488 			return 0;
   1489 		} else if (tagtype)
   1490 			ecb = li->queued[tagid];
   1491 	}
   1492 	if (ecb == NULL) {
   1493 		printf("%s: reselect from target %d lun %d tag %x:%x "
   1494 		    "with no nexus; sending ABORT\n",
   1495 		    sc->sc_dev.dv_xname, target, lun, tagtype, tagid);
   1496 		goto abort;
   1497 	}
   1498 
   1499 	/* Make this nexus active again. */
   1500 	sc->sc_state = NCR_CONNECTED;
   1501 	sc->sc_nexus = ecb;
   1502 	ncr53c9x_setsync(sc, ti);
   1503 
   1504 	if (ecb->flags & ECB_RESET)
   1505 		ncr53c9x_sched_msgout(SEND_DEV_RESET);
   1506 	else if (ecb->flags & ECB_ABORT)
   1507 		ncr53c9x_sched_msgout(SEND_ABORT);
   1508 
   1509 	/* Do an implicit RESTORE POINTERS. */
   1510 	sc->sc_dp = ecb->daddr;
   1511 	sc->sc_dleft = ecb->dleft;
   1512 
   1513 	return 0;
   1514 
   1515 reset:
   1516 	ncr53c9x_sched_msgout(SEND_DEV_RESET);
   1517 	return 1;
   1518 
   1519 abort:
   1520 	ncr53c9x_sched_msgout(SEND_ABORT);
   1521 	return 1;
   1522 }
   1523 
   1524 static inline int
   1525 __verify_msg_format(u_char *p, int len)
   1526 {
   1527 
   1528 	if (len == 1 && MSG_IS1BYTE(p[0]))
   1529 		return 1;
   1530 	if (len == 2 && MSG_IS2BYTE(p[0]))
   1531 		return 1;
   1532 	if (len >= 3 && MSG_ISEXTENDED(p[0]) &&
   1533 	    len == p[1] + 2)
   1534 		return 1;
   1535 
   1536 	return 0;
   1537 }
   1538 
   1539 /*
   1540  * Get an incoming message as initiator.
   1541  *
   1542  * The SCSI bus must already be in MESSAGE_IN_PHASE and there is a
   1543  * byte in the FIFO
   1544  */
   1545 void
   1546 ncr53c9x_msgin(struct ncr53c9x_softc *sc)
   1547 {
   1548 
   1549 	NCR_TRACE(("[ncr53c9x_msgin(curmsglen:%ld)] ", (long)sc->sc_imlen));
   1550 
   1551 	if (sc->sc_imlen == 0) {
   1552 		printf("%s: msgin: no msg byte available\n",
   1553 		    sc->sc_dev.dv_xname);
   1554 		return;
   1555 	}
   1556 
   1557 	/*
   1558 	 * Prepare for a new message.  A message should (according
   1559 	 * to the SCSI standard) be transmitted in one single
   1560 	 * MESSAGE_IN_PHASE. If we have been in some other phase,
   1561 	 * then this is a new message.
   1562 	 */
   1563 	if (sc->sc_prevphase != MESSAGE_IN_PHASE &&
   1564 	    sc->sc_state != NCR_RESELECTED) {
   1565 		printf("%s: phase change, dropping message, "
   1566 		    "prev %d, state %d\n",
   1567 		    sc->sc_dev.dv_xname, sc->sc_prevphase, sc->sc_state);
   1568 		sc->sc_flags &= ~NCR_DROP_MSGI;
   1569 		sc->sc_imlen = 0;
   1570 	}
   1571 
   1572 	/*
   1573 	 * If we're going to reject the message, don't bother storing
   1574 	 * the incoming bytes.  But still, we need to ACK them.
   1575 	 */
   1576 	if ((sc->sc_flags & NCR_DROP_MSGI) != 0) {
   1577 		NCRCMD(sc, NCRCMD_MSGOK);
   1578 		printf("<dropping msg byte %x>", sc->sc_imess[sc->sc_imlen]);
   1579 		return;
   1580 	}
   1581 
   1582 	if (sc->sc_imlen >= NCR_MAX_MSG_LEN) {
   1583 		ncr53c9x_sched_msgout(SEND_REJECT);
   1584 		sc->sc_flags |= NCR_DROP_MSGI;
   1585 	} else {
   1586 		u_char *pb;
   1587 		int plen;
   1588 
   1589 		switch (sc->sc_state) {
   1590 		/*
   1591 		 * if received message is the first of reselection
   1592 		 * then first byte is selid, and then message
   1593 		 */
   1594 		case NCR_RESELECTED:
   1595 			pb = sc->sc_imess + 1;
   1596 			plen = sc->sc_imlen - 1;
   1597 			break;
   1598 		default:
   1599 			pb = sc->sc_imess;
   1600 			plen = sc->sc_imlen;
   1601 			break;
   1602 		}
   1603 
   1604 		if (__verify_msg_format(pb, plen))
   1605 			goto gotit;
   1606 	}
   1607 
   1608 	/* Ack what we have so far */
   1609 	NCRCMD(sc, NCRCMD_MSGOK);
   1610 	return;
   1611 
   1612 gotit:
   1613 	NCR_MSGS(("gotmsg(%x) state %d", sc->sc_imess[0], sc->sc_state));
   1614 	/* we got complete message, flush the imess, */
   1615 	/* XXX nobody uses imlen below */
   1616 	sc->sc_imlen = 0;
   1617 	/*
   1618 	 * Now we should have a complete message (1 byte, 2 byte
   1619 	 * and moderately long extended messages).  We only handle
   1620 	 * extended messages which total length is shorter than
   1621 	 * NCR_MAX_MSG_LEN.  Longer messages will be amputated.
   1622 	 */
   1623 	switch (sc->sc_state) {
   1624 		struct ncr53c9x_ecb *ecb;
   1625 		struct ncr53c9x_tinfo *ti;
   1626 		struct ncr53c9x_linfo *li;
   1627 		int lun;
   1628 
   1629 	case NCR_CONNECTED:
   1630 		ecb = sc->sc_nexus;
   1631 		ti = &sc->sc_tinfo[ecb->xs->xs_periph->periph_target];
   1632 
   1633 		switch (sc->sc_imess[0]) {
   1634 		case MSG_CMDCOMPLETE:
   1635 			NCR_MSGS(("cmdcomplete "));
   1636 			if (sc->sc_dleft < 0) {
   1637 				scsipi_printaddr(ecb->xs->xs_periph);
   1638 				printf("got %ld extra bytes\n",
   1639 				    -(long)sc->sc_dleft);
   1640 				sc->sc_dleft = 0;
   1641 			}
   1642 			ecb->dleft = (ecb->flags & ECB_TENTATIVE_DONE) ?
   1643 			    0 : sc->sc_dleft;
   1644 			if ((ecb->flags & ECB_SENSE) == 0)
   1645 				ecb->xs->resid = ecb->dleft;
   1646 			sc->sc_state = NCR_CMDCOMPLETE;
   1647 			break;
   1648 
   1649 		case MSG_MESSAGE_REJECT:
   1650 			NCR_MSGS(("msg reject (msgout=%x) ", sc->sc_msgout));
   1651 			switch (sc->sc_msgout) {
   1652 			case SEND_TAG:
   1653 				/*
   1654 				 * Target does not like tagged queuing.
   1655 				 *  - Flush the command queue
   1656 				 *  - Disable tagged queuing for the target
   1657 				 *  - Dequeue ecb from the queued array.
   1658 				 */
   1659 				printf("%s: tagged queuing rejected: "
   1660 				    "target %d\n",
   1661 				    sc->sc_dev.dv_xname,
   1662 				    ecb->xs->xs_periph->periph_target);
   1663 
   1664 				NCR_MSGS(("(rejected sent tag)"));
   1665 				NCRCMD(sc, NCRCMD_FLUSH);
   1666 				DELAY(1);
   1667 				ti->flags &= ~T_TAG;
   1668 				lun = ecb->xs->xs_periph->periph_lun;
   1669 				li = TINFO_LUN(ti, lun);
   1670 				if (ecb->tag[0] &&
   1671 				    li->queued[ecb->tag[1]] != NULL) {
   1672 					li->queued[ecb->tag[1]] = NULL;
   1673 					li->used--;
   1674 				}
   1675 				ecb->tag[0] = ecb->tag[1] = 0;
   1676 				li->untagged = ecb;
   1677 				li->busy = 1;
   1678 				break;
   1679 
   1680 			case SEND_SDTR:
   1681 				printf("%s: sync transfer rejected: "
   1682 				    "target %d\n",
   1683 				    sc->sc_dev.dv_xname,
   1684 				    ecb->xs->xs_periph->periph_target);
   1685 
   1686 				sc->sc_flags &= ~NCR_SYNCHNEGO;
   1687 				ti->flags &= ~(T_NEGOTIATE | T_SYNCMODE);
   1688 				ncr53c9x_setsync(sc, ti);
   1689 				ncr53c9x_update_xfer_mode(sc,
   1690 				    ecb->xs->xs_periph->periph_target);
   1691 				break;
   1692 
   1693 			case SEND_WDTR:
   1694 				printf("%s: wide transfer rejected: "
   1695 				    "target %d\n",
   1696 				    sc->sc_dev.dv_xname,
   1697 				    ecb->xs->xs_periph->periph_target);
   1698 				ti->flags &= ~(T_WIDE | T_WDTRSENT);
   1699 				ti->width = 0;
   1700 				break;
   1701 
   1702 			case SEND_INIT_DET_ERR:
   1703 				goto abort;
   1704 			}
   1705 			break;
   1706 
   1707 		case MSG_NOOP:
   1708 			NCR_MSGS(("noop "));
   1709 			break;
   1710 
   1711 		case MSG_HEAD_OF_Q_TAG:
   1712 		case MSG_SIMPLE_Q_TAG:
   1713 		case MSG_ORDERED_Q_TAG:
   1714 			NCR_MSGS(("TAG %x:%x",
   1715 			    sc->sc_imess[0], sc->sc_imess[1]));
   1716 			break;
   1717 
   1718 		case MSG_DISCONNECT:
   1719 			NCR_MSGS(("disconnect "));
   1720 			ti->dconns++;
   1721 			sc->sc_state = NCR_DISCONNECT;
   1722 
   1723 			/*
   1724 			 * Mark the fact that all bytes have moved. The
   1725 			 * target may not bother to do a SAVE POINTERS
   1726 			 * at this stage. This flag will set the residual
   1727 			 * count to zero on MSG COMPLETE.
   1728 			 */
   1729 			if (sc->sc_dleft == 0)
   1730 				ecb->flags |= ECB_TENTATIVE_DONE;
   1731 
   1732 			break;
   1733 
   1734 		case MSG_SAVEDATAPOINTER:
   1735 			NCR_MSGS(("save datapointer "));
   1736 			ecb->daddr = sc->sc_dp;
   1737 			ecb->dleft = sc->sc_dleft;
   1738 			break;
   1739 
   1740 		case MSG_RESTOREPOINTERS:
   1741 			NCR_MSGS(("restore datapointer "));
   1742 			sc->sc_dp = ecb->daddr;
   1743 			sc->sc_dleft = ecb->dleft;
   1744 			break;
   1745 
   1746 		case MSG_EXTENDED:
   1747 			NCR_MSGS(("extended(%x) ", sc->sc_imess[2]));
   1748 			switch (sc->sc_imess[2]) {
   1749 			case MSG_EXT_SDTR:
   1750 				NCR_MSGS(("SDTR period %d, offset %d ",
   1751 				    sc->sc_imess[3], sc->sc_imess[4]));
   1752 				if (sc->sc_imess[1] != 3)
   1753 					goto reject;
   1754 				ti->period = sc->sc_imess[3];
   1755 				ti->offset = sc->sc_imess[4];
   1756 				ti->flags &= ~T_NEGOTIATE;
   1757 				if (sc->sc_minsync == 0 ||
   1758 				    ti->offset == 0 ||
   1759 				    ti->period > 124) {
   1760 #if 0
   1761 #ifdef NCR53C9X_DEBUG
   1762 					scsipi_printaddr(ecb->xs->xs_periph);
   1763 					printf("async mode\n");
   1764 #endif
   1765 #endif
   1766 					ti->flags &= ~T_SYNCMODE;
   1767 					if ((sc->sc_flags&NCR_SYNCHNEGO) == 0) {
   1768 						/*
   1769 						 * target initiated negotiation
   1770 						 */
   1771 						ti->offset = 0;
   1772 						ncr53c9x_sched_msgout(
   1773 						    SEND_SDTR);
   1774 					}
   1775 				} else {
   1776 					int p;
   1777 
   1778 					p = ncr53c9x_stp2cpb(sc, ti->period);
   1779 					ti->period = ncr53c9x_cpb2stp(sc, p);
   1780 					if ((sc->sc_flags&NCR_SYNCHNEGO) == 0) {
   1781 						/*
   1782 						 * target initiated negotiation
   1783 						 */
   1784 						if (ti->period <
   1785 						    sc->sc_minsync)
   1786 							ti->period =
   1787 							    sc->sc_minsync;
   1788 						if (ti->offset > 15)
   1789 							ti->offset = 15;
   1790 						ti->flags &= ~T_SYNCMODE;
   1791 						ncr53c9x_sched_msgout(
   1792 						    SEND_SDTR);
   1793 					} else {
   1794 						/* we are sync */
   1795 						ti->flags |= T_SYNCMODE;
   1796 					}
   1797 				}
   1798 				ncr53c9x_update_xfer_mode(sc,
   1799 				    ecb->xs->xs_periph->periph_target);
   1800 				sc->sc_flags &= ~NCR_SYNCHNEGO;
   1801 				ncr53c9x_setsync(sc, ti);
   1802 				break;
   1803 
   1804 			case MSG_EXT_WDTR:
   1805 #ifdef NCR53C9X_DEBUG
   1806 				printf("%s: wide mode %d\n",
   1807 				    sc->sc_dev.dv_xname, sc->sc_imess[3]);
   1808 #endif
   1809 				if (sc->sc_imess[3] == 1) {
   1810 					ti->cfg3 |= NCRFASCFG3_EWIDE;
   1811 					ncr53c9x_setsync(sc, ti);
   1812 				} else
   1813 					ti->width = 0;
   1814 				/*
   1815 				 * Device started width negotiation.
   1816 				 */
   1817 				if (!(ti->flags & T_WDTRSENT))
   1818 					ncr53c9x_sched_msgout(SEND_WDTR);
   1819 				ti->flags &= ~(T_WIDE | T_WDTRSENT);
   1820 				break;
   1821 			default:
   1822 				scsipi_printaddr(ecb->xs->xs_periph);
   1823 				printf("unrecognized MESSAGE EXTENDED;"
   1824 				    " sending REJECT\n");
   1825 				goto reject;
   1826 			}
   1827 			break;
   1828 
   1829 		default:
   1830 			NCR_MSGS(("ident "));
   1831 			scsipi_printaddr(ecb->xs->xs_periph);
   1832 			printf("unrecognized MESSAGE; sending REJECT\n");
   1833 		reject:
   1834 			ncr53c9x_sched_msgout(SEND_REJECT);
   1835 			break;
   1836 		}
   1837 		break;
   1838 
   1839 	case NCR_IDENTIFIED:
   1840 		/*
   1841 		 * IDENTIFY message was received and queue tag is expected now
   1842 		 */
   1843 		if ((sc->sc_imess[0] != MSG_SIMPLE_Q_TAG) ||
   1844 		    (sc->sc_msgify == 0)) {
   1845 			printf("%s: TAG reselect without IDENTIFY;"
   1846 			    " MSG %x;"
   1847 			    " sending DEVICE RESET\n",
   1848 			    sc->sc_dev.dv_xname,
   1849 			    sc->sc_imess[0]);
   1850 			goto reset;
   1851 		}
   1852 		(void)ncr53c9x_reselect(sc, sc->sc_msgify,
   1853 		    sc->sc_imess[0], sc->sc_imess[1]);
   1854 		break;
   1855 
   1856 	case NCR_RESELECTED:
   1857 		if (MSG_ISIDENTIFY(sc->sc_imess[1])) {
   1858 			sc->sc_msgify = sc->sc_imess[1];
   1859 		} else {
   1860 			printf("%s: reselect without IDENTIFY;"
   1861 			    " MSG %x;"
   1862 			    " sending DEVICE RESET\n",
   1863 			    sc->sc_dev.dv_xname,
   1864 			    sc->sc_imess[1]);
   1865 			goto reset;
   1866 		}
   1867 		(void) ncr53c9x_reselect(sc, sc->sc_msgify, 0, 0);
   1868 		break;
   1869 
   1870 	default:
   1871 		printf("%s: unexpected MESSAGE IN; sending DEVICE RESET\n",
   1872 		    sc->sc_dev.dv_xname);
   1873 	reset:
   1874 		ncr53c9x_sched_msgout(SEND_DEV_RESET);
   1875 		break;
   1876 
   1877 	abort:
   1878 		ncr53c9x_sched_msgout(SEND_ABORT);
   1879 		break;
   1880 	}
   1881 
   1882 	/* if we have more messages to send set ATN */
   1883 	if (sc->sc_msgpriq)
   1884 		NCRCMD(sc, NCRCMD_SETATN);
   1885 
   1886 	/* Ack last message byte */
   1887 	NCRCMD(sc, NCRCMD_MSGOK);
   1888 
   1889 	/* Done, reset message pointer. */
   1890 	sc->sc_flags &= ~NCR_DROP_MSGI;
   1891 	sc->sc_imlen = 0;
   1892 }
   1893 
   1894 
   1895 /*
   1896  * Send the highest priority, scheduled message
   1897  */
   1898 void
   1899 ncr53c9x_msgout(struct ncr53c9x_softc *sc)
   1900 {
   1901 	struct ncr53c9x_tinfo *ti;
   1902 	struct ncr53c9x_ecb *ecb;
   1903 	size_t size;
   1904 
   1905 	NCR_TRACE(("[ncr53c9x_msgout(priq:%x, prevphase:%x)]",
   1906 	    sc->sc_msgpriq, sc->sc_prevphase));
   1907 
   1908 	/*
   1909 	 * XXX - the NCR_ATN flag is not in sync with the actual ATN
   1910 	 *	 condition on the SCSI bus. The 53c9x chip
   1911 	 *	 automatically turns off ATN before sending the
   1912 	 *	 message byte.  (see also the comment below in the
   1913 	 *	 default case when picking out a message to send)
   1914 	 */
   1915 	if (sc->sc_flags & NCR_ATN) {
   1916 		if (sc->sc_prevphase != MESSAGE_OUT_PHASE) {
   1917 		new:
   1918 			NCRCMD(sc, NCRCMD_FLUSH);
   1919 #if 0
   1920 			DELAY(1);
   1921 #endif
   1922 			sc->sc_msgoutq = 0;
   1923 			sc->sc_omlen = 0;
   1924 		}
   1925 	} else {
   1926 		if (sc->sc_prevphase == MESSAGE_OUT_PHASE) {
   1927 			ncr53c9x_sched_msgout(sc->sc_msgoutq);
   1928 			goto new;
   1929 		} else {
   1930 			printf("%s at line %d: unexpected MESSAGE OUT phase\n",
   1931 			    sc->sc_dev.dv_xname, __LINE__);
   1932 		}
   1933 	}
   1934 
   1935 	if (sc->sc_omlen == 0) {
   1936 		/* Pick up highest priority message */
   1937 		sc->sc_msgout = sc->sc_msgpriq & -sc->sc_msgpriq;
   1938 		sc->sc_msgoutq |= sc->sc_msgout;
   1939 		sc->sc_msgpriq &= ~sc->sc_msgout;
   1940 		sc->sc_omlen = 1;		/* "Default" message len */
   1941 		switch (sc->sc_msgout) {
   1942 		case SEND_SDTR:
   1943 			ecb = sc->sc_nexus;
   1944 			ti = &sc->sc_tinfo[ecb->xs->xs_periph->periph_target];
   1945 			sc->sc_omess[0] = MSG_EXTENDED;
   1946 			sc->sc_omess[1] = MSG_EXT_SDTR_LEN;
   1947 			sc->sc_omess[2] = MSG_EXT_SDTR;
   1948 			sc->sc_omess[3] = ti->period;
   1949 			sc->sc_omess[4] = ti->offset;
   1950 			sc->sc_omlen = 5;
   1951 			if ((sc->sc_flags & NCR_SYNCHNEGO) == 0) {
   1952 				ti->flags |= T_SYNCMODE;
   1953 				ncr53c9x_setsync(sc, ti);
   1954 			}
   1955 			break;
   1956 		case SEND_WDTR:
   1957 			ecb = sc->sc_nexus;
   1958 			ti = &sc->sc_tinfo[ecb->xs->xs_periph->periph_target];
   1959 			sc->sc_omess[0] = MSG_EXTENDED;
   1960 			sc->sc_omess[1] = MSG_EXT_WDTR_LEN;
   1961 			sc->sc_omess[2] = MSG_EXT_WDTR;
   1962 			sc->sc_omess[3] = ti->width;
   1963 			sc->sc_omlen = 4;
   1964 			break;
   1965 		case SEND_IDENTIFY:
   1966 			if (sc->sc_state != NCR_CONNECTED) {
   1967 				printf("%s at line %d: no nexus\n",
   1968 				    sc->sc_dev.dv_xname, __LINE__);
   1969 			}
   1970 			ecb = sc->sc_nexus;
   1971 			sc->sc_omess[0] =
   1972 			    MSG_IDENTIFY(ecb->xs->xs_periph->periph_lun, 0);
   1973 			break;
   1974 		case SEND_TAG:
   1975 			if (sc->sc_state != NCR_CONNECTED) {
   1976 				printf("%s at line %d: no nexus\n",
   1977 				    sc->sc_dev.dv_xname, __LINE__);
   1978 			}
   1979 			ecb = sc->sc_nexus;
   1980 			sc->sc_omess[0] = ecb->tag[0];
   1981 			sc->sc_omess[1] = ecb->tag[1];
   1982 			sc->sc_omlen = 2;
   1983 			break;
   1984 		case SEND_DEV_RESET:
   1985 			sc->sc_flags |= NCR_ABORTING;
   1986 			sc->sc_omess[0] = MSG_BUS_DEV_RESET;
   1987 			ecb = sc->sc_nexus;
   1988 			ti = &sc->sc_tinfo[ecb->xs->xs_periph->periph_target];
   1989 			ti->flags &= ~T_SYNCMODE;
   1990 			ncr53c9x_update_xfer_mode(sc,
   1991 			    ecb->xs->xs_periph->periph_target);
   1992 			if ((ti->flags & T_SYNCHOFF) == 0)
   1993 				/* We can re-start sync negotiation */
   1994 				ti->flags |= T_NEGOTIATE;
   1995 			break;
   1996 		case SEND_PARITY_ERROR:
   1997 			sc->sc_omess[0] = MSG_PARITY_ERROR;
   1998 			break;
   1999 		case SEND_ABORT:
   2000 			sc->sc_flags |= NCR_ABORTING;
   2001 			sc->sc_omess[0] = MSG_ABORT;
   2002 			break;
   2003 		case SEND_INIT_DET_ERR:
   2004 			sc->sc_omess[0] = MSG_INITIATOR_DET_ERR;
   2005 			break;
   2006 		case SEND_REJECT:
   2007 			sc->sc_omess[0] = MSG_MESSAGE_REJECT;
   2008 			break;
   2009 		default:
   2010 			/*
   2011 			 * We normally do not get here, since the chip
   2012 			 * automatically turns off ATN before the last
   2013 			 * byte of a message is sent to the target.
   2014 			 * However, if the target rejects our (multi-byte)
   2015 			 * message early by switching to MSG IN phase
   2016 			 * ATN remains on, so the target may return to
   2017 			 * MSG OUT phase. If there are no scheduled messages
   2018 			 * left we send a NO-OP.
   2019 			 *
   2020 			 * XXX - Note that this leaves no useful purpose for
   2021 			 * the NCR_ATN flag.
   2022 			 */
   2023 			sc->sc_flags &= ~NCR_ATN;
   2024 			sc->sc_omess[0] = MSG_NOOP;
   2025 			break;
   2026 		}
   2027 		sc->sc_omp = sc->sc_omess;
   2028 	}
   2029 
   2030 #ifdef DEBUG
   2031 	if (ncr53c9x_debug & NCR_SHOWMSGS) {
   2032 		int i;
   2033 
   2034 		NCR_MSGS(("<msgout:"));
   2035 		for (i = 0; i < sc->sc_omlen; i++)
   2036 			NCR_MSGS((" %02x", sc->sc_omess[i]));
   2037 		NCR_MSGS(("> "));
   2038 	}
   2039 #endif
   2040 	if (sc->sc_rev == NCR_VARIANT_FAS366) {
   2041 		/*
   2042 		 * XXX fifo size
   2043 		 */
   2044 		ncr53c9x_flushfifo(sc);
   2045 		ncr53c9x_wrfifo(sc, sc->sc_omp, sc->sc_omlen);
   2046 		NCRCMD(sc, NCRCMD_TRANS);
   2047 	} else {
   2048 		/* (re)send the message */
   2049 		size = min(sc->sc_omlen, sc->sc_maxxfer);
   2050 		NCRDMA_SETUP(sc, &sc->sc_omp, &sc->sc_omlen, 0, &size);
   2051 		/* Program the SCSI counter */
   2052 		NCR_SET_COUNT(sc, size);
   2053 
   2054 		/* Load the count in and start the message-out transfer */
   2055 		NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
   2056 		NCRCMD(sc, NCRCMD_TRANS|NCRCMD_DMA);
   2057 		NCRDMA_GO(sc);
   2058 	}
   2059 }
   2060 
   2061 /*
   2062  * This is the most critical part of the driver, and has to know
   2063  * how to deal with *all* error conditions and phases from the SCSI
   2064  * bus. If there are no errors and the DMA was active, then call the
   2065  * DMA pseudo-interrupt handler. If this returns 1, then that was it
   2066  * and we can return from here without further processing.
   2067  *
   2068  * Most of this needs verifying.
   2069  */
   2070 int
   2071 ncr53c9x_intr(void *arg)
   2072 {
   2073 	struct ncr53c9x_softc *sc = arg;
   2074 	struct ncr53c9x_ecb *ecb;
   2075 	struct scsipi_periph *periph;
   2076 	struct ncr53c9x_tinfo *ti;
   2077 	size_t size;
   2078 	int nfifo;
   2079 
   2080 	NCR_INTS(("[ncr53c9x_intr: state %d]", sc->sc_state));
   2081 
   2082 	if (!NCRDMA_ISINTR(sc))
   2083 		return 0;
   2084 
   2085 	simple_lock(&sc->sc_lock);
   2086 again:
   2087 	/* and what do the registers say... */
   2088 	ncr53c9x_readregs(sc);
   2089 
   2090 	sc->sc_intrcnt.ev_count++;
   2091 
   2092 	/*
   2093 	 * At the moment, only a SCSI Bus Reset or Illegal
   2094 	 * Command are classed as errors. A disconnect is a
   2095 	 * valid condition, and we let the code check is the
   2096 	 * "NCR_BUSFREE_OK" flag was set before declaring it
   2097 	 * and error.
   2098 	 *
   2099 	 * Also, the status register tells us about "Gross
   2100 	 * Errors" and "Parity errors". Only the Gross Error
   2101 	 * is really bad, and the parity errors are dealt
   2102 	 * with later
   2103 	 *
   2104 	 * TODO
   2105 	 *	If there are too many parity error, go to slow
   2106 	 *	cable mode ?
   2107 	 */
   2108 
   2109 	/* SCSI Reset */
   2110 	if ((sc->sc_espintr & NCRINTR_SBR) != 0) {
   2111 		if ((NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) != 0) {
   2112 			NCRCMD(sc, NCRCMD_FLUSH);
   2113 			DELAY(1);
   2114 		}
   2115 		if (sc->sc_state != NCR_SBR) {
   2116 			printf("%s: SCSI bus reset\n", sc->sc_dev.dv_xname);
   2117 			ncr53c9x_init(sc, 0); /* Restart everything */
   2118 			goto out;
   2119 		}
   2120 #if 0
   2121 /*XXX*/		printf("<expected bus reset: "
   2122 		    "[intr %x, stat %x, step %d]>\n",
   2123 		    sc->sc_espintr, sc->sc_espstat, sc->sc_espstep);
   2124 #endif
   2125 		if (sc->sc_nexus != NULL)
   2126 			panic("%s: nexus in reset state",
   2127 			    sc->sc_dev.dv_xname);
   2128 		goto sched;
   2129 	}
   2130 
   2131 	ecb = sc->sc_nexus;
   2132 
   2133 #define NCRINTR_ERR (NCRINTR_SBR|NCRINTR_ILL)
   2134 	if (sc->sc_espintr & NCRINTR_ERR ||
   2135 	    sc->sc_espstat & NCRSTAT_GE) {
   2136 
   2137 		if ((sc->sc_espstat & NCRSTAT_GE) != 0) {
   2138 			/* Gross Error; no target ? */
   2139 			if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
   2140 				NCRCMD(sc, NCRCMD_FLUSH);
   2141 				DELAY(1);
   2142 			}
   2143 			if (sc->sc_state == NCR_CONNECTED ||
   2144 			    sc->sc_state == NCR_SELECTING) {
   2145 				ecb->xs->error = XS_TIMEOUT;
   2146 				ncr53c9x_done(sc, ecb);
   2147 			}
   2148 			goto out;
   2149 		}
   2150 
   2151 		if ((sc->sc_espintr & NCRINTR_ILL) != 0) {
   2152 			if ((sc->sc_flags & NCR_EXPECT_ILLCMD) != 0) {
   2153 				/*
   2154 				 * Eat away "Illegal command" interrupt
   2155 				 * on a ESP100 caused by a re-selection
   2156 				 * while we were trying to select
   2157 				 * another target.
   2158 				 */
   2159 #ifdef DEBUG
   2160 				printf("%s: ESP100 work-around activated\n",
   2161 					sc->sc_dev.dv_xname);
   2162 #endif
   2163 				sc->sc_flags &= ~NCR_EXPECT_ILLCMD;
   2164 				goto out;
   2165 			}
   2166 			/* illegal command, out of sync ? */
   2167 			printf("%s: illegal command: 0x%x "
   2168 			    "(state %d, phase %x, prevphase %x)\n",
   2169 			    sc->sc_dev.dv_xname, sc->sc_lastcmd,
   2170 			    sc->sc_state, sc->sc_phase, sc->sc_prevphase);
   2171 			if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
   2172 				NCRCMD(sc, NCRCMD_FLUSH);
   2173 				DELAY(1);
   2174 			}
   2175 			ncr53c9x_init(sc, 1); /* Restart everything */
   2176 			goto out;
   2177 		}
   2178 	}
   2179 	sc->sc_flags &= ~NCR_EXPECT_ILLCMD;
   2180 
   2181 	/*
   2182 	 * Call if DMA is active.
   2183 	 *
   2184 	 * If DMA_INTR returns true, then maybe go 'round the loop
   2185 	 * again in case there is no more DMA queued, but a phase
   2186 	 * change is expected.
   2187 	 */
   2188 	if (NCRDMA_ISACTIVE(sc)) {
   2189 		int r = NCRDMA_INTR(sc);
   2190 		if (r == -1) {
   2191 			printf("%s: DMA error; resetting\n",
   2192 			    sc->sc_dev.dv_xname);
   2193 			ncr53c9x_init(sc, 1);
   2194 			goto out;
   2195 		}
   2196 		/* If DMA active here, then go back to work... */
   2197 		if (NCRDMA_ISACTIVE(sc))
   2198 			goto out;
   2199 
   2200 		if ((sc->sc_espstat & NCRSTAT_TC) == 0) {
   2201 			/*
   2202 			 * DMA not completed.  If we can not find a
   2203 			 * acceptable explanation, print a diagnostic.
   2204 			 */
   2205 			if (sc->sc_state == NCR_SELECTING)
   2206 				/*
   2207 				 * This can happen if we are reselected
   2208 				 * while using DMA to select a target.
   2209 				 */
   2210 				/*void*/;
   2211 			else if (sc->sc_prevphase == MESSAGE_OUT_PHASE) {
   2212 				/*
   2213 				 * Our (multi-byte) message (eg SDTR) was
   2214 				 * interrupted by the target to send
   2215 				 * a MSG REJECT.
   2216 				 * Print diagnostic if current phase
   2217 				 * is not MESSAGE IN.
   2218 				 */
   2219 				if (sc->sc_phase != MESSAGE_IN_PHASE)
   2220 					printf("%s: !TC on MSG OUT"
   2221 					    " [intr %x, stat %x, step %d]"
   2222 					    " prevphase %x, resid %lx\n",
   2223 					    sc->sc_dev.dv_xname,
   2224 					    sc->sc_espintr,
   2225 					    sc->sc_espstat,
   2226 					    sc->sc_espstep,
   2227 					    sc->sc_prevphase,
   2228 					    (u_long)sc->sc_omlen);
   2229 			} else if (sc->sc_dleft == 0) {
   2230 				/*
   2231 				 * The DMA operation was started for
   2232 				 * a DATA transfer. Print a diagnostic
   2233 				 * if the DMA counter and TC bit
   2234 				 * appear to be out of sync.
   2235 				 */
   2236 				printf("%s: !TC on DATA XFER"
   2237 				    " [intr %x, stat %x, step %d]"
   2238 				    " prevphase %x, resid %x\n",
   2239 				    sc->sc_dev.dv_xname,
   2240 				    sc->sc_espintr,
   2241 				    sc->sc_espstat,
   2242 				    sc->sc_espstep,
   2243 				    sc->sc_prevphase,
   2244 				    ecb ? ecb->dleft : -1);
   2245 			}
   2246 		}
   2247 	}
   2248 
   2249 	/*
   2250 	 * Check for less serious errors.
   2251 	 */
   2252 	if ((sc->sc_espstat & NCRSTAT_PE) != 0) {
   2253 		printf("%s: SCSI bus parity error\n", sc->sc_dev.dv_xname);
   2254 		if (sc->sc_prevphase == MESSAGE_IN_PHASE)
   2255 			ncr53c9x_sched_msgout(SEND_PARITY_ERROR);
   2256 		else
   2257 			ncr53c9x_sched_msgout(SEND_INIT_DET_ERR);
   2258 	}
   2259 
   2260 	if ((sc->sc_espintr & NCRINTR_DIS) != 0) {
   2261 		sc->sc_msgify = 0;
   2262 		NCR_INTS(("<DISC [intr %x, stat %x, step %d]>",
   2263 		    sc->sc_espintr,sc->sc_espstat,sc->sc_espstep));
   2264 		if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
   2265 			NCRCMD(sc, NCRCMD_FLUSH);
   2266 #if 0
   2267 			DELAY(1);
   2268 #endif
   2269 		}
   2270 		/*
   2271 		 * This command must (apparently) be issued within
   2272 		 * 250mS of a disconnect. So here you are...
   2273 		 */
   2274 		NCRCMD(sc, NCRCMD_ENSEL);
   2275 
   2276 		switch (sc->sc_state) {
   2277 		case NCR_RESELECTED:
   2278 			goto sched;
   2279 
   2280 		case NCR_SELECTING:
   2281 		{
   2282 			struct ncr53c9x_linfo *li;
   2283 
   2284 			ecb->xs->error = XS_SELTIMEOUT;
   2285 
   2286 			/* Selection timeout -- discard all LUNs if empty */
   2287 			periph = ecb->xs->xs_periph;
   2288 			ti = &sc->sc_tinfo[periph->periph_target];
   2289 			li = LIST_FIRST(&ti->luns);
   2290 			while (li != NULL) {
   2291 				if (li->untagged == NULL && li->used == 0) {
   2292 					if (li->lun < NCR_NLUN)
   2293 						ti->lun[li->lun] = NULL;
   2294 					LIST_REMOVE(li, link);
   2295 					free(li, M_DEVBUF);
   2296 					/*
   2297 					 * Restart the search at the beginning
   2298 					 */
   2299 					li = LIST_FIRST(&ti->luns);
   2300 					continue;
   2301 				}
   2302 				li = LIST_NEXT(li, link);
   2303 			}
   2304 			goto finish;
   2305 		}
   2306 		case NCR_CONNECTED:
   2307 			if ((sc->sc_flags & NCR_SYNCHNEGO) != 0) {
   2308 #ifdef NCR53C9X_DEBUG
   2309 				if (ecb != NULL)
   2310 					scsipi_printaddr(ecb->xs->xs_periph);
   2311 				printf("sync nego not completed!\n");
   2312 #endif
   2313 				ti = &sc->sc_tinfo[
   2314 				    ecb->xs->xs_periph->periph_target];
   2315 				sc->sc_flags &= ~NCR_SYNCHNEGO;
   2316 				ti->flags &= ~(T_NEGOTIATE | T_SYNCMODE);
   2317 			}
   2318 
   2319 			/* it may be OK to disconnect */
   2320 			if ((sc->sc_flags & NCR_ABORTING) == 0) {
   2321 				/*
   2322 				 * Section 5.1.1 of the SCSI 2 spec
   2323 				 * suggests issuing a REQUEST SENSE
   2324 				 * following an unexpected disconnect.
   2325 				 * Some devices go into a contingent
   2326 				 * allegiance condition when
   2327 				 * disconnecting, and this is necessary
   2328 				 * to clean up their state.
   2329 				 */
   2330 				printf("%s: unexpected disconnect "
   2331 			"[state %d, intr %x, stat %x, phase(c %x, p %x)]; ",
   2332 					sc->sc_dev.dv_xname, sc->sc_state,
   2333 					sc->sc_espintr, sc->sc_espstat,
   2334 					sc->sc_phase, sc->sc_prevphase);
   2335 
   2336 				if ((ecb->flags & ECB_SENSE) != 0) {
   2337 					printf("resetting\n");
   2338 					goto reset;
   2339 				}
   2340 				printf("sending REQUEST SENSE\n");
   2341 				callout_stop(&ecb->xs->xs_callout);
   2342 				ncr53c9x_sense(sc, ecb);
   2343 				goto out;
   2344 			}
   2345 
   2346 			ecb->xs->error = XS_TIMEOUT;
   2347 			goto finish;
   2348 
   2349 		case NCR_DISCONNECT:
   2350 			sc->sc_nexus = NULL;
   2351 			goto sched;
   2352 
   2353 		case NCR_CMDCOMPLETE:
   2354 			goto finish;
   2355 		}
   2356 	}
   2357 
   2358 	switch (sc->sc_state) {
   2359 
   2360 	case NCR_SBR:
   2361 		printf("%s: waiting for SCSI Bus Reset to happen\n",
   2362 		    sc->sc_dev.dv_xname);
   2363 		goto out;
   2364 
   2365 	case NCR_RESELECTED:
   2366 		/*
   2367 		 * we must be continuing a message ?
   2368 		 */
   2369 		printf("%s: unhandled reselect continuation, "
   2370 		    "state %d, intr %02x\n",
   2371 		    sc->sc_dev.dv_xname, sc->sc_state, sc->sc_espintr);
   2372 		ncr53c9x_init(sc, 1);
   2373 		goto out;
   2374 
   2375 	case NCR_IDENTIFIED:
   2376 		ecb = sc->sc_nexus;
   2377 		if (sc->sc_phase != MESSAGE_IN_PHASE) {
   2378 			int i = (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF);
   2379  			/*
   2380 			 * Things are seriously screwed up.
   2381 			 * Pull the brakes, i.e. reset
   2382 			 */
   2383 			printf("%s: target didn't send tag: %d bytes in fifo\n",
   2384 			    sc->sc_dev.dv_xname, i);
   2385 			/* Drain and display fifo */
   2386 			while (i-- > 0)
   2387 				printf("[%d] ", NCR_READ_REG(sc, NCR_FIFO));
   2388 
   2389 			ncr53c9x_init(sc, 1);
   2390 			goto out;
   2391 		} else
   2392 			goto msgin;
   2393 
   2394 	case NCR_IDLE:
   2395 	case NCR_SELECTING:
   2396 		ecb = sc->sc_nexus;
   2397 		if (sc->sc_espintr & NCRINTR_RESEL) {
   2398 			sc->sc_msgpriq = sc->sc_msgout = sc->sc_msgoutq = 0;
   2399 			sc->sc_flags = 0;
   2400 			/*
   2401 			 * If we're trying to select a
   2402 			 * target ourselves, push our command
   2403 			 * back into the ready list.
   2404 			 */
   2405 			if (sc->sc_state == NCR_SELECTING) {
   2406 				NCR_INTS(("backoff selector "));
   2407 				callout_stop(&ecb->xs->xs_callout);
   2408 				ncr53c9x_dequeue(sc, ecb);
   2409 				TAILQ_INSERT_HEAD(&sc->ready_list, ecb, chain);
   2410 				ecb->flags |= ECB_READY;
   2411 				ecb = sc->sc_nexus = NULL;
   2412 			}
   2413 			sc->sc_state = NCR_RESELECTED;
   2414 			if (sc->sc_phase != MESSAGE_IN_PHASE) {
   2415 				/*
   2416 				 * Things are seriously screwed up.
   2417 				 * Pull the brakes, i.e. reset
   2418 				 */
   2419 				printf("%s: target didn't identify\n",
   2420 				    sc->sc_dev.dv_xname);
   2421 				ncr53c9x_init(sc, 1);
   2422 				goto out;
   2423 			}
   2424 			/*
   2425 			 * The C90 only inhibits FIFO writes until reselection
   2426 			 * is complete, instead of waiting until the interrupt
   2427 			 * status register has been read.  So, if the reselect
   2428 			 * happens while we were entering command bytes (for
   2429 			 * another target) some of those bytes can appear in
   2430 			 * the FIFO here, after the interrupt is taken.
   2431 			 *
   2432 			 * To remedy this situation, pull the Selection ID
   2433 			 * and Identify message from the FIFO directly, and
   2434 			 * ignore any extraneous fifo contents. Also, set
   2435 			 * a flag that allows one Illegal Command Interrupt
   2436 			 * to occur which the chip also generates as a result
   2437 			 * of writing to the FIFO during a reselect.
   2438 			 */
   2439 			if (sc->sc_rev == NCR_VARIANT_ESP100) {
   2440 				nfifo = NCR_READ_REG(sc, NCR_FFLAG) &
   2441 				    NCRFIFO_FF;
   2442 				sc->sc_imess[0] = NCR_READ_REG(sc, NCR_FIFO);
   2443 				sc->sc_imess[1] = NCR_READ_REG(sc, NCR_FIFO);
   2444 				sc->sc_imlen = 2;
   2445 				if (nfifo != 2) {
   2446 					/* Flush the rest */
   2447 					NCRCMD(sc, NCRCMD_FLUSH);
   2448 				}
   2449 				sc->sc_flags |= NCR_EXPECT_ILLCMD;
   2450 				if (nfifo > 2)
   2451 					nfifo = 2; /* We fixed it.. */
   2452 			} else
   2453 				nfifo = ncr53c9x_rdfifo(sc, NCR_RDFIFO_START);
   2454 
   2455 			if (nfifo != 2) {
   2456 				printf("%s: RESELECT: %d bytes in FIFO! "
   2457 				    "[intr %x, stat %x, step %d, "
   2458 				    "prevphase %x]\n",
   2459 				    sc->sc_dev.dv_xname,
   2460 				    nfifo,
   2461 				    sc->sc_espintr,
   2462 				    sc->sc_espstat,
   2463 				    sc->sc_espstep,
   2464 				    sc->sc_prevphase);
   2465 				ncr53c9x_init(sc, 1);
   2466 				goto out;
   2467 			}
   2468 			sc->sc_selid = sc->sc_imess[0];
   2469 			NCR_INTS(("selid=%02x ", sc->sc_selid));
   2470 
   2471 			/* Handle identify message */
   2472 			ncr53c9x_msgin(sc);
   2473 
   2474 			if (sc->sc_state != NCR_CONNECTED &&
   2475 			    sc->sc_state != NCR_IDENTIFIED) {
   2476 				/* IDENTIFY fail?! */
   2477 				printf("%s: identify failed, "
   2478 				    "state %d, intr %02x\n",
   2479 				    sc->sc_dev.dv_xname, sc->sc_state,
   2480 				    sc->sc_espintr);
   2481 				ncr53c9x_init(sc, 1);
   2482 				goto out;
   2483 			}
   2484 			goto shortcut; /* ie. next phase expected soon */
   2485 		}
   2486 
   2487 #define	NCRINTR_DONE	(NCRINTR_FC|NCRINTR_BS)
   2488 		if ((sc->sc_espintr & NCRINTR_DONE) == NCRINTR_DONE) {
   2489 			/*
   2490 			 * Arbitration won; examine the `step' register
   2491 			 * to determine how far the selection could progress.
   2492 			 */
   2493 			ecb = sc->sc_nexus;
   2494 			if (ecb == NULL)
   2495 				panic("ncr53c9x: no nexus");
   2496 
   2497 			periph = ecb->xs->xs_periph;
   2498 			ti = &sc->sc_tinfo[periph->periph_target];
   2499 
   2500 			switch (sc->sc_espstep) {
   2501 			case 0:
   2502 				/*
   2503 				 * The target did not respond with a
   2504 				 * message out phase - probably an old
   2505 				 * device that doesn't recognize ATN.
   2506 				 * Clear ATN and just continue, the
   2507 				 * target should be in the command
   2508 				 * phase.
   2509 				 * XXXX check for command phase?
   2510 				 */
   2511 				NCRCMD(sc, NCRCMD_RSTATN);
   2512 				break;
   2513 			case 1:
   2514 				if ((ti->flags & T_NEGOTIATE) == 0 &&
   2515 				    ecb->tag[0] == 0) {
   2516 					printf("%s: step 1 & !NEG\n",
   2517 					    sc->sc_dev.dv_xname);
   2518 					goto reset;
   2519 				}
   2520 				if (sc->sc_phase != MESSAGE_OUT_PHASE) {
   2521 					printf("%s: !MSGOUT\n",
   2522 					    sc->sc_dev.dv_xname);
   2523 					goto reset;
   2524 				}
   2525 				if (ti->flags & T_WIDE) {
   2526 					ti->flags |= T_WDTRSENT;
   2527 					ncr53c9x_sched_msgout(SEND_WDTR);
   2528 				}
   2529 				if (ti->flags & T_NEGOTIATE) {
   2530 					/* Start negotiating */
   2531 					ti->period = sc->sc_minsync;
   2532 					ti->offset = 15;
   2533 					sc->sc_flags |= NCR_SYNCHNEGO;
   2534 					if (ecb->tag[0])
   2535 						ncr53c9x_sched_msgout(
   2536 						    SEND_TAG|SEND_SDTR);
   2537 					else
   2538 						ncr53c9x_sched_msgout(
   2539 						    SEND_SDTR);
   2540 				} else {
   2541 					/* Could not do ATN3 so send TAG */
   2542 					ncr53c9x_sched_msgout(SEND_TAG);
   2543 				}
   2544 				sc->sc_prevphase = MESSAGE_OUT_PHASE; /* XXXX */
   2545 				break;
   2546 			case 3:
   2547 				/*
   2548 				 * Grr, this is supposed to mean
   2549 				 * "target left command phase  prematurely".
   2550 				 * It seems to happen regularly when
   2551 				 * sync mode is on.
   2552 				 * Look at FIFO to see if command went out.
   2553 				 * (Timing problems?)
   2554 				 */
   2555 				if (sc->sc_features & NCR_F_DMASELECT) {
   2556 					if (sc->sc_cmdlen == 0)
   2557 						/* Hope for the best.. */
   2558 						break;
   2559 				} else if ((NCR_READ_REG(sc, NCR_FFLAG)
   2560 				    & NCRFIFO_FF) == 0) {
   2561 					/* Hope for the best.. */
   2562 					break;
   2563 				}
   2564 				printf("(%s:%d:%d): selection failed;"
   2565 				    " %d left in FIFO "
   2566 				    "[intr %x, stat %x, step %d]\n",
   2567 				    sc->sc_dev.dv_xname,
   2568 				    periph->periph_target,
   2569 				    periph->periph_lun,
   2570 				    NCR_READ_REG(sc, NCR_FFLAG)
   2571 				     & NCRFIFO_FF,
   2572 				    sc->sc_espintr, sc->sc_espstat,
   2573 				    sc->sc_espstep);
   2574 				NCRCMD(sc, NCRCMD_FLUSH);
   2575 				ncr53c9x_sched_msgout(SEND_ABORT);
   2576 				goto out;
   2577 			case 2:
   2578 				/* Select stuck at Command Phase */
   2579 				NCRCMD(sc, NCRCMD_FLUSH);
   2580 				break;
   2581 			case 4:
   2582 				if (sc->sc_features & NCR_F_DMASELECT &&
   2583 				    sc->sc_cmdlen != 0)
   2584 					printf("(%s:%d:%d): select; "
   2585 					    "%lu left in DMA buffer "
   2586 					    "[intr %x, stat %x, step %d]\n",
   2587 					    sc->sc_dev.dv_xname,
   2588 					    periph->periph_target,
   2589 					    periph->periph_lun,
   2590 					    (u_long)sc->sc_cmdlen,
   2591 					    sc->sc_espintr,
   2592 					    sc->sc_espstat,
   2593 					    sc->sc_espstep);
   2594 				/* So far, everything went fine */
   2595 				break;
   2596 			}
   2597 
   2598 			sc->sc_prevphase = INVALID_PHASE; /* ?? */
   2599 			/* Do an implicit RESTORE POINTERS. */
   2600 			sc->sc_dp = ecb->daddr;
   2601 			sc->sc_dleft = ecb->dleft;
   2602 			sc->sc_state = NCR_CONNECTED;
   2603 			break;
   2604 
   2605 		} else {
   2606 
   2607 			printf("%s: unexpected status after select"
   2608 			    ": [intr %x, stat %x, step %x]\n",
   2609 			    sc->sc_dev.dv_xname,
   2610 			    sc->sc_espintr, sc->sc_espstat, sc->sc_espstep);
   2611 			NCRCMD(sc, NCRCMD_FLUSH);
   2612 			DELAY(1);
   2613 			goto reset;
   2614 		}
   2615 		if (sc->sc_state == NCR_IDLE) {
   2616 			printf("%s: stray interrupt\n", sc->sc_dev.dv_xname);
   2617 			simple_unlock(&sc->sc_lock);
   2618 			return 0;
   2619 		}
   2620 		break;
   2621 
   2622 	case NCR_CONNECTED:
   2623 		if ((sc->sc_flags & NCR_ICCS) != 0) {
   2624 			/* "Initiate Command Complete Steps" in progress */
   2625 			u_char msg;
   2626 
   2627 			sc->sc_flags &= ~NCR_ICCS;
   2628 
   2629 			if (!(sc->sc_espintr & NCRINTR_DONE)) {
   2630 				printf("%s: ICCS: "
   2631 				    ": [intr %x, stat %x, step %x]\n",
   2632 				    sc->sc_dev.dv_xname,
   2633 				    sc->sc_espintr, sc->sc_espstat,
   2634 				    sc->sc_espstep);
   2635 			}
   2636 			ncr53c9x_rdfifo(sc, NCR_RDFIFO_START);
   2637 			if (sc->sc_imlen < 2)
   2638 				printf("%s: can't get status, only %d bytes\n",
   2639 				    sc->sc_dev.dv_xname, (int)sc->sc_imlen);
   2640 			ecb->stat = sc->sc_imess[sc->sc_imlen - 2];
   2641 			msg = sc->sc_imess[sc->sc_imlen - 1];
   2642 			NCR_PHASE(("<stat:(%x,%x)>", ecb->stat, msg));
   2643 			if (msg == MSG_CMDCOMPLETE) {
   2644 				ecb->dleft = (ecb->flags & ECB_TENTATIVE_DONE)
   2645 					? 0 : sc->sc_dleft;
   2646 				if ((ecb->flags & ECB_SENSE) == 0)
   2647 					ecb->xs->resid = ecb->dleft;
   2648 				sc->sc_state = NCR_CMDCOMPLETE;
   2649 			} else
   2650 				printf("%s: STATUS_PHASE: msg %d\n",
   2651 				    sc->sc_dev.dv_xname, msg);
   2652 			sc->sc_imlen = 0;
   2653 			NCRCMD(sc, NCRCMD_MSGOK);
   2654 			goto shortcut; /* ie. wait for disconnect */
   2655 		}
   2656 		break;
   2657 
   2658 	default:
   2659 		printf("%s: invalid state: %d [intr %x, phase(c %x, p %x)]\n",
   2660 			sc->sc_dev.dv_xname, sc->sc_state,
   2661 			sc->sc_espintr, sc->sc_phase, sc->sc_prevphase);
   2662 		goto reset;
   2663 	}
   2664 
   2665 	/*
   2666 	 * Driver is now in state NCR_CONNECTED, i.e. we
   2667 	 * have a current command working the SCSI bus.
   2668 	 */
   2669 	if (sc->sc_state != NCR_CONNECTED || ecb == NULL) {
   2670 		panic("ncr53c9x: no nexus");
   2671 	}
   2672 
   2673 	switch (sc->sc_phase) {
   2674 	case MESSAGE_OUT_PHASE:
   2675 		NCR_PHASE(("MESSAGE_OUT_PHASE "));
   2676 		ncr53c9x_msgout(sc);
   2677 		sc->sc_prevphase = MESSAGE_OUT_PHASE;
   2678 		break;
   2679 
   2680 	case MESSAGE_IN_PHASE:
   2681 msgin:
   2682 		NCR_PHASE(("MESSAGE_IN_PHASE "));
   2683 		if ((sc->sc_espintr & NCRINTR_BS) != 0) {
   2684 			if ((sc->sc_rev != NCR_VARIANT_FAS366) ||
   2685 			    !(sc->sc_espstat2 & NCRFAS_STAT2_EMPTY)) {
   2686 				NCRCMD(sc, NCRCMD_FLUSH);
   2687 			}
   2688 			sc->sc_flags |= NCR_WAITI;
   2689 			NCRCMD(sc, NCRCMD_TRANS);
   2690 		} else if ((sc->sc_espintr & NCRINTR_FC) != 0) {
   2691 			if ((sc->sc_flags & NCR_WAITI) == 0) {
   2692 				printf("%s: MSGIN: unexpected FC bit: "
   2693 				    "[intr %x, stat %x, step %x]\n",
   2694 				    sc->sc_dev.dv_xname,
   2695 				    sc->sc_espintr, sc->sc_espstat,
   2696 				    sc->sc_espstep);
   2697 			}
   2698 			sc->sc_flags &= ~NCR_WAITI;
   2699 			ncr53c9x_rdfifo(sc,
   2700 			    (sc->sc_prevphase == sc->sc_phase) ?
   2701 			    NCR_RDFIFO_CONTINUE : NCR_RDFIFO_START);
   2702 			ncr53c9x_msgin(sc);
   2703 		} else {
   2704 			printf("%s: MSGIN: weird bits: "
   2705 			    "[intr %x, stat %x, step %x]\n",
   2706 			    sc->sc_dev.dv_xname,
   2707 			    sc->sc_espintr, sc->sc_espstat, sc->sc_espstep);
   2708 		}
   2709 		sc->sc_prevphase = MESSAGE_IN_PHASE;
   2710 		goto shortcut;	/* i.e. expect data to be ready */
   2711 
   2712 	case COMMAND_PHASE:
   2713 		/*
   2714 		 * Send the command block. Normally we don't see this
   2715 		 * phase because the SEL_ATN command takes care of
   2716 		 * all this. However, we end up here if either the
   2717 		 * target or we wanted to exchange some more messages
   2718 		 * first (e.g. to start negotiations).
   2719 		 */
   2720 
   2721 		NCR_PHASE(("COMMAND_PHASE 0x%02x (%d) ",
   2722 		    ecb->cmd.cmd.opcode, ecb->clen));
   2723 		if (NCR_READ_REG(sc, NCR_FFLAG) & NCRFIFO_FF) {
   2724 			NCRCMD(sc, NCRCMD_FLUSH);
   2725 #if 0
   2726 			DELAY(1);
   2727 #endif
   2728 		}
   2729 		if (sc->sc_features & NCR_F_DMASELECT) {
   2730 			/* setup DMA transfer for command */
   2731 			size = ecb->clen;
   2732 			sc->sc_cmdlen = size;
   2733 			sc->sc_cmdp = (void *)&ecb->cmd.cmd;
   2734 			NCRDMA_SETUP(sc, &sc->sc_cmdp, &sc->sc_cmdlen,
   2735 			    0, &size);
   2736 			/* Program the SCSI counter */
   2737 			NCR_SET_COUNT(sc, size);
   2738 
   2739 			/* load the count in */
   2740 			NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
   2741 
   2742 			/* start the command transfer */
   2743 			NCRCMD(sc, NCRCMD_TRANS | NCRCMD_DMA);
   2744 			NCRDMA_GO(sc);
   2745 		} else {
   2746 			ncr53c9x_wrfifo(sc, (u_char *)&ecb->cmd.cmd, ecb->clen);
   2747 			NCRCMD(sc, NCRCMD_TRANS);
   2748 		}
   2749 		sc->sc_prevphase = COMMAND_PHASE;
   2750 		break;
   2751 
   2752 	case DATA_OUT_PHASE:
   2753 		NCR_PHASE(("DATA_OUT_PHASE [%ld] ",(long)sc->sc_dleft));
   2754 		NCRCMD(sc, NCRCMD_FLUSH);
   2755 		size = min(sc->sc_dleft, sc->sc_maxxfer);
   2756 		NCRDMA_SETUP(sc, &sc->sc_dp, &sc->sc_dleft, 0, &size);
   2757 		sc->sc_prevphase = DATA_OUT_PHASE;
   2758 		goto setup_xfer;
   2759 
   2760 	case DATA_IN_PHASE:
   2761 		NCR_PHASE(("DATA_IN_PHASE "));
   2762 		if (sc->sc_rev == NCR_VARIANT_ESP100)
   2763 			NCRCMD(sc, NCRCMD_FLUSH);
   2764 		size = min(sc->sc_dleft, sc->sc_maxxfer);
   2765 		NCRDMA_SETUP(sc, &sc->sc_dp, &sc->sc_dleft, 1, &size);
   2766 		sc->sc_prevphase = DATA_IN_PHASE;
   2767 	setup_xfer:
   2768 		/* Target returned to data phase: wipe "done" memory */
   2769 		ecb->flags &= ~ECB_TENTATIVE_DONE;
   2770 
   2771 		/* Program the SCSI counter */
   2772 		NCR_SET_COUNT(sc, size);
   2773 
   2774 		/* load the count in */
   2775 		NCRCMD(sc, NCRCMD_NOP|NCRCMD_DMA);
   2776 
   2777 		/*
   2778 		 * Note that if `size' is 0, we've already transceived
   2779 		 * all the bytes we want but we're still in DATA PHASE.
   2780 		 * Apparently, the device needs padding. Also, a
   2781 		 * transfer size of 0 means "maximum" to the chip
   2782 		 * DMA logic.
   2783 		 */
   2784 		NCRCMD(sc,
   2785 		    (size == 0 ? NCRCMD_TRPAD : NCRCMD_TRANS) | NCRCMD_DMA);
   2786 		NCRDMA_GO(sc);
   2787 		goto out;
   2788 
   2789 	case STATUS_PHASE:
   2790 		NCR_PHASE(("STATUS_PHASE "));
   2791 		sc->sc_flags |= NCR_ICCS;
   2792 		NCRCMD(sc, NCRCMD_ICCS);
   2793 		sc->sc_prevphase = STATUS_PHASE;
   2794 		goto shortcut;	/* i.e. expect status results soon */
   2795 
   2796 	case INVALID_PHASE:
   2797 		break;
   2798 
   2799 	default:
   2800 		printf("%s: unexpected bus phase; resetting\n",
   2801 		    sc->sc_dev.dv_xname);
   2802 		goto reset;
   2803 	}
   2804 
   2805 out:
   2806 	simple_unlock(&sc->sc_lock);
   2807 	return 1;
   2808 
   2809 reset:
   2810 	ncr53c9x_init(sc, 1);
   2811 	goto out;
   2812 
   2813 finish:
   2814 	ncr53c9x_done(sc, ecb);
   2815 	goto out;
   2816 
   2817 sched:
   2818 	sc->sc_state = NCR_IDLE;
   2819 	ncr53c9x_sched(sc);
   2820 	goto out;
   2821 
   2822 shortcut:
   2823 	/*
   2824 	 * The idea is that many of the SCSI operations take very little
   2825 	 * time, and going away and getting interrupted is too high an
   2826 	 * overhead to pay. For example, selecting, sending a message
   2827 	 * and command and then doing some work can be done in one "pass".
   2828 	 *
   2829 	 * The delay is a heuristic. It is 2 when at 20MHz, 2 at 25MHz and 1
   2830 	 * at 40MHz. This needs testing.
   2831 	 */
   2832 	{
   2833 		struct timeval wait, cur;
   2834 
   2835 		microtime(&wait);
   2836 		wait.tv_usec += 50 / sc->sc_freq;
   2837 		if (wait.tv_usec > 1000000) {
   2838 			wait.tv_sec++;
   2839 			wait.tv_usec -= 1000000;
   2840 		}
   2841 		do {
   2842 			if (NCRDMA_ISINTR(sc))
   2843 				goto again;
   2844 			microtime(&cur);
   2845 		} while (cur.tv_sec <= wait.tv_sec &&
   2846 			 cur.tv_usec <= wait.tv_usec);
   2847 	}
   2848 	goto out;
   2849 }
   2850 
   2851 void
   2852 ncr53c9x_abort(struct ncr53c9x_softc *sc, struct ncr53c9x_ecb *ecb)
   2853 {
   2854 
   2855 	/* 2 secs for the abort */
   2856 	ecb->timeout = NCR_ABORT_TIMEOUT;
   2857 	ecb->flags |= ECB_ABORT;
   2858 
   2859 	if (ecb == sc->sc_nexus) {
   2860 		/*
   2861 		 * If we're still selecting, the message will be scheduled
   2862 		 * after selection is complete.
   2863 		 */
   2864 		if (sc->sc_state == NCR_CONNECTED)
   2865 			ncr53c9x_sched_msgout(SEND_ABORT);
   2866 
   2867 		/*
   2868 		 * Reschedule timeout.
   2869 		 */
   2870 		callout_reset(&ecb->xs->xs_callout, mstohz(ecb->timeout),
   2871 		    ncr53c9x_timeout, ecb);
   2872 	} else {
   2873 		/*
   2874 		 * Just leave the command where it is.
   2875 		 * XXX - what choice do we have but to reset the SCSI
   2876 		 *	 eventually?
   2877 		 */
   2878 		if (sc->sc_state == NCR_IDLE)
   2879 			ncr53c9x_sched(sc);
   2880 	}
   2881 }
   2882 
   2883 void
   2884 ncr53c9x_timeout(void *arg)
   2885 {
   2886 	struct ncr53c9x_ecb *ecb = arg;
   2887 	struct scsipi_xfer *xs = ecb->xs;
   2888 	struct scsipi_periph *periph = xs->xs_periph;
   2889 	struct ncr53c9x_softc *sc =
   2890 	    (void *)periph->periph_channel->chan_adapter->adapt_dev;
   2891 	struct ncr53c9x_tinfo *ti = &sc->sc_tinfo[periph->periph_target];
   2892 	int s;
   2893 
   2894 	scsipi_printaddr(periph);
   2895 	printf("%s: timed out [ecb %p (flags 0x%x, dleft %x, stat %x)], "
   2896 	    "<state %d, nexus %p, phase(l %x, c %x, p %x), resid %lx, "
   2897 	    "msg(q %x,o %x) %s>",
   2898 	    sc->sc_dev.dv_xname,
   2899 	    ecb, ecb->flags, ecb->dleft, ecb->stat,
   2900 	    sc->sc_state, sc->sc_nexus,
   2901 	    NCR_READ_REG(sc, NCR_STAT),
   2902 	    sc->sc_phase, sc->sc_prevphase,
   2903 	    (long)sc->sc_dleft, sc->sc_msgpriq, sc->sc_msgout,
   2904 	    NCRDMA_ISACTIVE(sc) ? "DMA active" : "");
   2905 #if NCR53C9X_DEBUG > 1
   2906 	printf("TRACE: %s.", ecb->trace);
   2907 #endif
   2908 
   2909 	s = splbio();
   2910 	simple_lock(&sc->sc_lock);
   2911 
   2912 	if (ecb->flags & ECB_ABORT) {
   2913 		/* abort timed out */
   2914 		printf(" AGAIN\n");
   2915 
   2916 		ncr53c9x_init(sc, 1);
   2917 	} else {
   2918 		/* abort the operation that has timed out */
   2919 		printf("\n");
   2920 		xs->error = XS_TIMEOUT;
   2921 		ncr53c9x_abort(sc, ecb);
   2922 
   2923 		/* Disable sync mode if stuck in a data phase */
   2924 		if (ecb == sc->sc_nexus &&
   2925 		    (ti->flags & T_SYNCMODE) != 0 &&
   2926 		    (sc->sc_phase & (MSGI|CDI)) == 0) {
   2927 			/* XXX ASYNC CALLBACK! */
   2928 			scsipi_printaddr(periph);
   2929 			printf("sync negotiation disabled\n");
   2930 			sc->sc_cfflags |=
   2931 			    (1 << ((periph->periph_target & 7) + 8));
   2932 			ncr53c9x_update_xfer_mode(sc, periph->periph_target);
   2933 		}
   2934 	}
   2935 
   2936 	simple_unlock(&sc->sc_lock);
   2937 	splx(s);
   2938 }
   2939 
   2940 void
   2941 ncr53c9x_watch(void *arg)
   2942 {
   2943 	struct ncr53c9x_softc *sc = (struct ncr53c9x_softc *)arg;
   2944 	struct ncr53c9x_tinfo *ti;
   2945 	struct ncr53c9x_linfo *li;
   2946 	int t, s;
   2947 	/* Delete any structures that have not been used in 10min. */
   2948 	time_t old = time_second - (10 * 60);
   2949 
   2950 	s = splbio();
   2951 	simple_lock(&sc->sc_lock);
   2952 	for (t = 0; t < sc->sc_ntarg; t++) {
   2953 		ti = &sc->sc_tinfo[t];
   2954 		li = LIST_FIRST(&ti->luns);
   2955 		while (li) {
   2956 			if (li->last_used < old &&
   2957 			    li->untagged == NULL &&
   2958 			    li->used == 0) {
   2959 				if (li->lun < NCR_NLUN)
   2960 					ti->lun[li->lun] = NULL;
   2961 				LIST_REMOVE(li, link);
   2962 				free(li, M_DEVBUF);
   2963 				/* Restart the search at the beginning */
   2964 				li = LIST_FIRST(&ti->luns);
   2965 				continue;
   2966 			}
   2967 			li = LIST_NEXT(li, link);
   2968 		}
   2969 	}
   2970 	simple_unlock(&sc->sc_lock);
   2971 	splx(s);
   2972 	callout_reset(&sc->sc_watchdog, 60 * hz, ncr53c9x_watch, sc);
   2973 }
   2974 
   2975