xref: /netbsd-src/sys/arch/sparc/dev/sw.c (revision 1ca5c1b28139779176bd5c13ad7c5f25c0bcd5f8)
1 /*	$NetBSD: sw.c,v 1.5 2001/08/20 12:00:51 wiz Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Adam Glass, David Jones, Gordon W. Ross, and Jason R. Thorpe.
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  * This file contains only the machine-dependent parts of the
41  * Sun4 SCSI driver.  (Autoconfig stuff and DMA functions.)
42  * The machine-independent parts are in ncr5380sbc.c
43  *
44  * Supported hardware includes:
45  * Sun "SCSI Weird" on OBIO (sw: Sun 4/100-series)
46  * Sun SCSI-3 on VME (si: Sun 4/200-series, others)
47  *
48  * The VME variant has a bit to enable or disable the DMA engine,
49  * but that bit also gates the interrupt line from the NCR5380!
50  * Therefore, in order to get any interrupt from the 5380, (i.e.
51  * for reselect) one must clear the DMA engine transfer count and
52  * then enable DMA.  This has the further complication that you
53  * CAN NOT touch the NCR5380 while the DMA enable bit is set, so
54  * we have to turn DMA back off before we even look at the 5380.
55  *
56  * What wonderfully whacky hardware this is!
57  *
58  * David Jones wrote the initial version of this module for NetBSD/sun3,
59  * which included support for the VME adapter only. (no reselection).
60  *
61  * Gordon Ross added support for the Sun 3 OBIO adapter, and re-worked
62  * both the VME and OBIO code to support disconnect/reselect.
63  * (Required figuring out the hardware "features" noted above.)
64  *
65  * The autoconfiguration boilerplate came from Adam Glass.
66  *
67  * Jason R. Thorpe ported the autoconfiguration and VME portions to
68  * NetBSD/sparc, and added initial support for the 4/100 "SCSI Weird",
69  * a wacky OBIO variant of the VME SCSI-3.  Many thanks to Chuck Cranor
70  * for lots of helpful tips and suggestions.  Thanks also to Paul Kranenburg
71  * and Chris Torek for bits of insight needed along the way.  Thanks to
72  * David Gilbert and Andrew Gillham who risked filesystem life-and-limb
73  * for the sake of testing.  Andrew Gillham helped work out the bugs
74  * the 4/100 DMA code.
75  */
76 
77 /*
78  * NOTE: support for the 4/100 "SCSI Weird" is not complete!  DMA
79  * works, but interrupts (and, thus, reselection) don't.  I don't know
80  * why, and I don't have a machine to test this on further.
81  *
82  * DMA, DMA completion interrupts, and reselection work fine on my
83  * 4/260 with modern SCSI-II disks attached.  I've had reports of
84  * reselection failing on Sun Shoebox-type configurations where
85  * there are multiple non-SCSI devices behind Emulex or Adaptec
86  * bridges.  These devices pre-date the SCSI-I spec, and might not
87  * bahve the way the 5380 code expects.  For this reason, only
88  * DMA is enabled by default in this driver.
89  *
90  *	Jason R. Thorpe <thorpej@NetBSD.ORG>
91  *	December 8, 1995
92  */
93 
94 #include "opt_ddb.h"
95 
96 #include <sys/types.h>
97 #include <sys/param.h>
98 #include <sys/systm.h>
99 #include <sys/kernel.h>
100 #include <sys/malloc.h>
101 #include <sys/errno.h>
102 #include <sys/device.h>
103 #include <sys/buf.h>
104 
105 #include <machine/bus.h>
106 #include <machine/intr.h>
107 #include <machine/autoconf.h>
108 
109 #include <dev/scsipi/scsi_all.h>
110 #include <dev/scsipi/scsipi_all.h>
111 #include <dev/scsipi/scsipi_debug.h>
112 #include <dev/scsipi/scsiconf.h>
113 
114 #ifndef DDB
115 #define	Debugger()
116 #endif
117 
118 #ifndef DEBUG
119 #define DEBUG XXX
120 #endif
121 
122 #define COUNT_SW_LEFTOVERS	XXX	/* See sw DMA completion code */
123 
124 #include <dev/ic/ncr5380reg.h>
125 #include <dev/ic/ncr5380var.h>
126 
127 #include <sparc/dev/swreg.h>
128 
129 /*
130  * Transfers smaller than this are done using PIO
131  * (on assumption they're not worth DMA overhead)
132  */
133 #define	MIN_DMA_LEN 128
134 
135 /*
136  * Transfers lager than 65535 bytes need to be split-up.
137  * (Some of the FIFO logic has only 16 bits counters.)
138  * Make the size an integer multiple of the page size
139  * to avoid buf/cluster remap problems.  (paranoid?)
140  */
141 #define	MAX_DMA_LEN 0xE000
142 
143 #ifdef	DEBUG
144 int sw_debug = 0;
145 #endif
146 
147 /*
148  * This structure is used to keep track of mapped DMA requests.
149  */
150 struct sw_dma_handle {
151 	int 		dh_flags;
152 #define	SIDH_BUSY	0x01		/* This DH is in use */
153 #define	SIDH_OUT	0x02		/* DMA does data out (write) */
154 	u_char		*dh_addr;	/* KVA of start of buffer */
155 	int 		dh_maplen;	/* Original data length */
156 	long		dh_startingpa;	/* PA of buffer; for "sw" */
157 	bus_dmamap_t	dh_dmamap;
158 #define dh_dvma	dh_dmamap->dm_segs[0].ds_addr /* VA of buffer in DVMA space */
159 };
160 
161 /*
162  * The first structure member has to be the ncr5380_softc
163  * so we can just cast to go back and fourth between them.
164  */
165 struct sw_softc {
166 	struct ncr5380_softc	ncr_sc;
167 	bus_space_tag_t		sc_bustag;	/* bus tags */
168 	bus_dma_tag_t		sc_dmatag;
169 
170 	struct sw_dma_handle *sc_dma;
171 	int		sc_xlen;	/* length of current DMA segment. */
172 	int		sc_options;	/* options for this instance. */
173 };
174 
175 /*
176  * Options.  By default, DMA is enabled and DMA completion interrupts
177  * and reselect are disabled.  You may enable additional features
178  * the `flags' directive in your kernel's configuration file.
179  *
180  * Alternatively, you can patch your kernel with DDB or some other
181  * mechanism.  The sc_options member of the softc is OR'd with
182  * the value in sw_options.
183  *
184  * On the "sw", interrupts (and thus) reselection don't work, so they're
185  * disabled by default.  DMA is still a little dangerous, too.
186  *
187  * Note, there's a separate sw_options to make life easier.
188  */
189 #define	SW_ENABLE_DMA	0x01	/* Use DMA (maybe polled) */
190 #define	SW_DMA_INTR	0x02	/* DMA completion interrupts */
191 #define	SW_DO_RESELECT	0x04	/* Allow disconnect/reselect */
192 #define	SW_OPTIONS_MASK	(SW_ENABLE_DMA|SW_DMA_INTR|SW_DO_RESELECT)
193 #define SW_OPTIONS_BITS	"\10\3RESELECT\2DMA_INTR\1DMA"
194 int sw_options = SW_ENABLE_DMA;
195 
196 static int	sw_match __P((struct device *, struct cfdata *, void *));
197 static void	sw_attach __P((struct device *, struct device *, void *));
198 static int	sw_intr __P((void *));
199 static void	sw_reset_adapter __P((struct ncr5380_softc *));
200 static void	sw_minphys __P((struct buf *));
201 
202 void	sw_dma_alloc __P((struct ncr5380_softc *));
203 void	sw_dma_free __P((struct ncr5380_softc *));
204 void	sw_dma_poll __P((struct ncr5380_softc *));
205 
206 void	sw_dma_setup __P((struct ncr5380_softc *));
207 void	sw_dma_start __P((struct ncr5380_softc *));
208 void	sw_dma_eop __P((struct ncr5380_softc *));
209 void	sw_dma_stop __P((struct ncr5380_softc *));
210 
211 void	sw_intr_on __P((struct ncr5380_softc *));
212 void	sw_intr_off __P((struct ncr5380_softc *));
213 
214 /* Shorthand bus space access */
215 #define SWREG_READ(sc, index) \
216 	bus_space_read_4((sc)->sc_regt, (sc)->sc_regh, index)
217 #define SWREG_WRITE(sc, index, v) \
218 	bus_space_write_4((sc)->sc_regt, (sc)->sc_regh, index, v)
219 
220 
221 /* The Sun "SCSI Weird" 4/100 obio controller. */
222 struct cfattach sw_ca = {
223 	sizeof(struct sw_softc), sw_match, sw_attach
224 };
225 
226 static int
227 sw_match(parent, cf, aux)
228 	struct device	*parent;
229 	struct cfdata *cf;
230 	void *aux;
231 {
232 	union obio_attach_args *uoba = aux;
233 	struct obio4_attach_args *oba;
234 
235 	/* Nothing but a Sun 4/100 is going to have these devices. */
236 	if (cpuinfo.cpu_type != CPUTYP_4_100)
237 		return (0);
238 
239 	if (uoba->uoba_isobio4 == 0)
240 		return (0);
241 
242 	/* Make sure there is something there... */
243 	oba = &uoba->uoba_oba4;
244 	return (bus_space_probe(oba->oba_bustag, 0, oba->oba_paddr,
245 				1,	/* probe size */
246 				1,	/* offset */
247 				0,	/* flags */
248 				NULL, NULL));
249 }
250 
251 static void
252 sw_attach(parent, self, aux)
253 	struct device	*parent, *self;
254 	void		*aux;
255 {
256 	struct sw_softc *sc = (struct sw_softc *) self;
257 	struct ncr5380_softc *ncr_sc = &sc->ncr_sc;
258 	union obio_attach_args *uoba = aux;
259 	struct obio4_attach_args *oba = &uoba->uoba_oba4;
260 	bus_space_handle_t bh;
261 	char bits[64];
262 	int i;
263 
264 	sc->sc_dmatag = oba->oba_dmatag;
265 
266 	/* Map the controller registers. */
267 	if (obio_bus_map(oba->oba_bustag, oba->oba_paddr,
268 			 0,
269 			 SWREG_BANK_SZ,
270 			 BUS_SPACE_MAP_LINEAR,
271 			 0, &bh) != 0) {
272 		printf("%s: cannot map registers\n", self->dv_xname);
273 		return;
274 	}
275 
276 	ncr_sc->sc_regt = oba->oba_bustag;
277 	ncr_sc->sc_regh = bh;
278 
279 	sc->sc_options = sw_options;
280 
281 	ncr_sc->sc_dma_setup = sw_dma_setup;
282 	ncr_sc->sc_dma_start = sw_dma_start;
283 	ncr_sc->sc_dma_eop   = sw_dma_stop;
284 	ncr_sc->sc_dma_stop  = sw_dma_stop;
285 	ncr_sc->sc_intr_on   = sw_intr_on;
286 	ncr_sc->sc_intr_off  = sw_intr_off;
287 
288 	/*
289 	 * Establish interrupt channel.
290 	 * Default interrupt priority always is 3.  At least, that's
291 	 * what my board seems to be at.  --thorpej
292 	 */
293 	if (oba->oba_pri == -1)
294 		oba->oba_pri = 3;
295 
296 	(void)bus_intr_establish(oba->oba_bustag, oba->oba_pri, IPL_BIO, 0,
297 				 sw_intr, sc);
298 
299 	printf(" pri %d\n", oba->oba_pri);
300 
301 
302 	/*
303 	 * Pull in the options flags.  Allow the user to completely
304 	 * override the default values.
305 	 */
306 	if ((ncr_sc->sc_dev.dv_cfdata->cf_flags & SW_OPTIONS_MASK) != 0)
307 		sc->sc_options =
308 		    (ncr_sc->sc_dev.dv_cfdata->cf_flags & SW_OPTIONS_MASK);
309 
310 	/*
311 	 * Initialize fields used by the MI code
312 	 */
313 
314 	/* NCR5380 register bank offsets */
315 	ncr_sc->sci_r0 = 0;
316 	ncr_sc->sci_r1 = 1;
317 	ncr_sc->sci_r2 = 2;
318 	ncr_sc->sci_r3 = 3;
319 	ncr_sc->sci_r4 = 4;
320 	ncr_sc->sci_r5 = 5;
321 	ncr_sc->sci_r6 = 6;
322 	ncr_sc->sci_r7 = 7;
323 
324 	ncr_sc->sc_rev = NCR_VARIANT_NCR5380;
325 
326 	/*
327 	 * MD function pointers used by the MI code.
328 	 */
329 	ncr_sc->sc_pio_out = ncr5380_pio_out;
330 	ncr_sc->sc_pio_in =  ncr5380_pio_in;
331 	ncr_sc->sc_dma_alloc = sw_dma_alloc;
332 	ncr_sc->sc_dma_free  = sw_dma_free;
333 	ncr_sc->sc_dma_poll  = sw_dma_poll;
334 
335 	ncr_sc->sc_flags = 0;
336 	if ((sc->sc_options & SW_DO_RESELECT) == 0)
337 		ncr_sc->sc_no_disconnect = 0xFF;
338 	if ((sc->sc_options & SW_DMA_INTR) == 0)
339 		ncr_sc->sc_flags |= NCR5380_FORCE_POLLING;
340 	ncr_sc->sc_min_dma_len = MIN_DMA_LEN;
341 
342 
343 	/*
344 	 * Allocate DMA handles.
345 	 */
346 	i = SCI_OPENINGS * sizeof(struct sw_dma_handle);
347 	sc->sc_dma = (struct sw_dma_handle *)malloc(i, M_DEVBUF, M_NOWAIT);
348 	if (sc->sc_dma == NULL)
349 		panic("sw: dma handle malloc failed\n");
350 
351 	for (i = 0; i < SCI_OPENINGS; i++) {
352 		sc->sc_dma[i].dh_flags = 0;
353 
354 		/* Allocate a DMA handle */
355 		if (bus_dmamap_create(
356 				sc->sc_dmatag,	/* tag */
357 				MAXPHYS,	/* size */
358 				1,		/* nsegments */
359 				MAXPHYS,	/* maxsegsz */
360 				0,		/* boundary */
361 				BUS_DMA_NOWAIT,
362 				&sc->sc_dma[i].dh_dmamap) != 0) {
363 
364 			printf("%s: DMA buffer map create error\n",
365 				ncr_sc->sc_dev.dv_xname);
366 			return;
367 		}
368 	}
369 
370 	if (sc->sc_options) {
371 		printf("%s: options=%s\n", ncr_sc->sc_dev.dv_xname,
372 			bitmask_snprintf(sc->sc_options, SW_OPTIONS_BITS,
373 			    bits, sizeof(bits)));
374 	}
375 
376 	ncr_sc->sc_channel.chan_id = 7;
377 	ncr_sc->sc_adapter.adapt_minphys = sw_minphys;
378 
379 	/* Initialize sw board */
380 	sw_reset_adapter(ncr_sc);
381 
382 	/* Attach the ncr5380 chip driver */
383 	ncr5380_attach(ncr_sc);
384 }
385 
386 static void
387 sw_minphys(struct buf *bp)
388 {
389 	if (bp->b_bcount > MAX_DMA_LEN) {
390 #ifdef DEBUG
391 		if (sw_debug) {
392 			printf("sw_minphys len = 0x%x.\n", MAX_DMA_LEN);
393 			Debugger();
394 		}
395 #endif
396 		bp->b_bcount = MAX_DMA_LEN;
397 	}
398 	minphys(bp);
399 }
400 
401 #define CSR_WANT (SW_CSR_SBC_IP | SW_CSR_DMA_IP | \
402 	SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR )
403 
404 static int
405 sw_intr(void *arg)
406 {
407 	struct sw_softc *sc = arg;
408 	struct ncr5380_softc *ncr_sc = (struct ncr5380_softc *)arg;
409 	int dma_error, claimed;
410 	u_short csr;
411 
412 	claimed = 0;
413 	dma_error = 0;
414 
415 	/* SBC interrupt? DMA interrupt? */
416 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
417 
418 	NCR_TRACE("sw_intr: csr=0x%x\n", csr);
419 
420 	if (csr & SW_CSR_DMA_CONFLICT) {
421 		dma_error |= SW_CSR_DMA_CONFLICT;
422 		printf("sw_intr: DMA conflict\n");
423 	}
424 	if (csr & SW_CSR_DMA_BUS_ERR) {
425 		dma_error |= SW_CSR_DMA_BUS_ERR;
426 		printf("sw_intr: DMA bus error\n");
427 	}
428 	if (dma_error) {
429 		if (sc->ncr_sc.sc_state & NCR_DOINGDMA)
430 			sc->ncr_sc.sc_state |= NCR_ABORTING;
431 		/* Make sure we will call the main isr. */
432 		csr |= SW_CSR_DMA_IP;
433 	}
434 
435 	if (csr & (SW_CSR_SBC_IP | SW_CSR_DMA_IP)) {
436 		claimed = ncr5380_intr(&sc->ncr_sc);
437 #ifdef DEBUG
438 		if (!claimed) {
439 			printf("sw_intr: spurious from SBC\n");
440 			if (sw_debug & 4) {
441 				Debugger();	/* XXX */
442 			}
443 		}
444 #endif
445 	}
446 
447 	return (claimed);
448 }
449 
450 
451 static void
452 sw_reset_adapter(struct ncr5380_softc *ncr_sc)
453 {
454 
455 #ifdef	DEBUG
456 	if (sw_debug) {
457 		printf("sw_reset_adapter\n");
458 	}
459 #endif
460 
461 	/*
462 	 * The reset bits in the CSR are active low.
463 	 */
464 	SWREG_WRITE(ncr_sc, SWREG_CSR, 0);
465 	delay(10);
466 	SWREG_WRITE(ncr_sc, SWREG_CSR, SW_CSR_SCSI_RES);
467 
468 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
469 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
470 	delay(10);
471 	SWREG_WRITE(ncr_sc, SWREG_CSR, SW_CSR_SCSI_RES | SW_CSR_INTR_EN);
472 
473 	SCI_CLR_INTR(ncr_sc);
474 }
475 
476 
477 /*****************************************************************
478  * Common functions for DMA
479  ****************************************************************/
480 
481 /*
482  * Allocate a DMA handle and put it in sc->sc_dma.  Prepare
483  * for DMA transfer.  On the Sun4, this means mapping the buffer
484  * into DVMA space.
485  */
486 void
487 sw_dma_alloc(ncr_sc)
488 	struct ncr5380_softc *ncr_sc;
489 {
490 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
491 	struct sci_req *sr = ncr_sc->sc_current;
492 	struct scsipi_xfer *xs = sr->sr_xs;
493 	struct sw_dma_handle *dh;
494 	int i, xlen;
495 	u_long addr;
496 
497 #ifdef DIAGNOSTIC
498 	if (sr->sr_dma_hand != NULL)
499 		panic("sw_dma_alloc: already have DMA handle");
500 #endif
501 
502 #if 1	/* XXX - Temporary */
503 	/* XXX - In case we think DMA is completely broken... */
504 	if ((sc->sc_options & SW_ENABLE_DMA) == 0)
505 		return;
506 #endif
507 
508 	addr = (u_long) ncr_sc->sc_dataptr;
509 	xlen = ncr_sc->sc_datalen;
510 
511 	/* If the DMA start addr is misaligned then do PIO */
512 	if ((addr & 1) || (xlen & 1)) {
513 		printf("sw_dma_alloc: misaligned.\n");
514 		return;
515 	}
516 
517 	/* Make sure our caller checked sc_min_dma_len. */
518 	if (xlen < MIN_DMA_LEN)
519 		panic("sw_dma_alloc: xlen=0x%x\n", xlen);
520 
521 	/* Find free DMA handle.  Guaranteed to find one since we have
522 	   as many DMA handles as the driver has processes. */
523 	for (i = 0; i < SCI_OPENINGS; i++) {
524 		if ((sc->sc_dma[i].dh_flags & SIDH_BUSY) == 0)
525 			goto found;
526 	}
527 	panic("sw: no free DMA handles.");
528 
529 found:
530 	dh = &sc->sc_dma[i];
531 	dh->dh_flags = SIDH_BUSY;
532 	dh->dh_addr = (u_char *)addr;
533 	dh->dh_maplen  = xlen;
534 
535 	/* Copy the "write" flag for convenience. */
536 	if ((xs->xs_control & XS_CTL_DATA_OUT) != 0)
537 		dh->dh_flags |= SIDH_OUT;
538 
539 	/*
540 	 * Double-map the buffer into DVMA space.  If we can't re-map
541 	 * the buffer, we print a warning and fall back to PIO mode.
542 	 *
543 	 * NOTE: it is not safe to sleep here!
544 	 */
545 	if (bus_dmamap_load(sc->sc_dmatag, dh->dh_dmamap,
546 			    (caddr_t)addr, xlen, NULL, BUS_DMA_NOWAIT) != 0) {
547 		/* Can't remap segment */
548 		printf("sw_dma_alloc: can't remap 0x%lx/0x%x, doing PIO\n",
549 			addr, dh->dh_maplen);
550 		dh->dh_flags = 0;
551 		return;
552 	}
553 	bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap, addr, xlen,
554 			(dh->dh_flags & SIDH_OUT)
555 				? BUS_DMASYNC_PREWRITE
556 				: BUS_DMASYNC_PREREAD);
557 
558 	/* success */
559 	sr->sr_dma_hand = dh;
560 
561 	return;
562 }
563 
564 
565 void
566 sw_dma_free(ncr_sc)
567 	struct ncr5380_softc *ncr_sc;
568 {
569 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
570 	struct sci_req *sr = ncr_sc->sc_current;
571 	struct sw_dma_handle *dh = sr->sr_dma_hand;
572 
573 #ifdef DIAGNOSTIC
574 	if (dh == NULL)
575 		panic("sw_dma_free: no DMA handle");
576 #endif
577 
578 	if (ncr_sc->sc_state & NCR_DOINGDMA)
579 		panic("sw_dma_free: free while in progress");
580 
581 	if (dh->dh_flags & SIDH_BUSY) {
582 		/* Give back the DVMA space. */
583 		bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap,
584 				dh->dh_dvma, dh->dh_maplen,
585 				(dh->dh_flags & SIDH_OUT)
586 					? BUS_DMASYNC_POSTWRITE
587 					: BUS_DMASYNC_POSTREAD);
588 		bus_dmamap_unload(sc->sc_dmatag, dh->dh_dmamap);
589 		dh->dh_flags = 0;
590 	}
591 	sr->sr_dma_hand = NULL;
592 }
593 
594 
595 /*
596  * Poll (spin-wait) for DMA completion.
597  * Called right after xx_dma_start(), and
598  * xx_dma_stop() will be called next.
599  * Same for either VME or OBIO.
600  */
601 void
602 sw_dma_poll(ncr_sc)
603 	struct ncr5380_softc *ncr_sc;
604 {
605 	struct sci_req *sr = ncr_sc->sc_current;
606 	int tmo, csr_mask, csr;
607 
608 	/* Make sure DMA started successfully. */
609 	if (ncr_sc->sc_state & NCR_ABORTING)
610 		return;
611 
612 	csr_mask = SW_CSR_SBC_IP | SW_CSR_DMA_IP |
613 		SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR;
614 
615 	tmo = 50000;	/* X100 = 5 sec. */
616 	for (;;) {
617 		csr = SWREG_READ(ncr_sc, SWREG_CSR);
618 		if (csr & csr_mask)
619 			break;
620 		if (--tmo <= 0) {
621 			printf("%s: DMA timeout (while polling)\n",
622 			    ncr_sc->sc_dev.dv_xname);
623 			/* Indicate timeout as MI code would. */
624 			sr->sr_flags |= SR_OVERDUE;
625 			break;
626 		}
627 		delay(100);
628 	}
629 
630 #ifdef	DEBUG
631 	if (sw_debug) {
632 		printf("sw_dma_poll: done, csr=0x%x\n", csr);
633 	}
634 #endif
635 }
636 
637 
638 /*
639  * This is called when the bus is going idle,
640  * so we want to enable the SBC interrupts.
641  * That is controlled by the DMA enable!
642  * Who would have guessed!
643  * What a NASTY trick!
644  *
645  * XXX THIS MIGHT NOT WORK RIGHT!
646  */
647 void
648 sw_intr_on(ncr_sc)
649 	struct ncr5380_softc *ncr_sc;
650 {
651 	u_int32_t csr;
652 
653 	sw_dma_setup(ncr_sc);
654 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
655 	csr |= SW_CSR_DMA_EN;	/* XXX - this bit is for vme only?! */
656 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
657 }
658 
659 /*
660  * This is called when the bus is idle and we are
661  * about to start playing with the SBC chip.
662  *
663  * XXX THIS MIGHT NOT WORK RIGHT!
664  */
665 void
666 sw_intr_off(ncr_sc)
667 	struct ncr5380_softc *ncr_sc;
668 {
669 	u_int32_t csr;
670 
671 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
672 	csr &= ~SW_CSR_DMA_EN;
673 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
674 }
675 
676 
677 /*
678  * This function is called during the COMMAND or MSG_IN phase
679  * that precedes a DATA_IN or DATA_OUT phase, in case we need
680  * to setup the DMA engine before the bus enters a DATA phase.
681  *
682  * On the OBIO version we just clear the DMA count and address
683  * here (to make sure it stays idle) and do the real setup
684  * later, in dma_start.
685  */
686 void
687 sw_dma_setup(ncr_sc)
688 	struct ncr5380_softc *ncr_sc;
689 {
690 	u_int32_t csr;
691 
692 	/* No FIFO to reset on "sw". */
693 
694 	/* Set direction (assume recv here) */
695 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
696 	csr &= ~SW_CSR_SEND;
697 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
698 
699 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
700 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
701 }
702 
703 
704 void
705 sw_dma_start(ncr_sc)
706 	struct ncr5380_softc *ncr_sc;
707 {
708 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
709 	struct sci_req *sr = ncr_sc->sc_current;
710 	struct sw_dma_handle *dh = sr->sr_dma_hand;
711 	u_long dva;
712 	int xlen, adj, adjlen;
713 	u_int mode;
714 	u_int32_t csr;
715 
716 	/*
717 	 * Get the DVMA mapping for this segment.
718 	 */
719 	dva = (u_long)(dh->dh_dvma);
720 	if (dva & 1)
721 		panic("sw_dma_start: bad dva=0x%lx", dva);
722 
723 	xlen = ncr_sc->sc_datalen;
724 	xlen &= ~1;
725 	sc->sc_xlen = xlen;	/* XXX: or less... */
726 
727 #ifdef	DEBUG
728 	if (sw_debug & 2) {
729 		printf("sw_dma_start: dh=%p, dva=0x%lx, xlen=%d\n",
730 		    dh, dva, xlen);
731 	}
732 #endif
733 
734 	/*
735 	 * Set up the DMA controller.
736 	 * Note that (dh->dh_len < sc_datalen)
737 	 */
738 
739 	/* Set direction (send/recv) */
740 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
741 	if (dh->dh_flags & SIDH_OUT) {
742 		csr |= SW_CSR_SEND;
743 	} else {
744 		csr &= ~SW_CSR_SEND;
745 	}
746 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
747 
748 	/*
749 	 * The "sw" needs longword aligned transfers.  We
750 	 * detect a shortword aligned transfer here, and adjust the
751 	 * DMA transfer by 2 bytes.  These two bytes are read/written
752 	 * in PIO mode just before the DMA is started.
753 	 */
754 	adj = 0;
755 	if (dva & 2) {
756 		adj = 2;
757 #ifdef DEBUG
758 		if (sw_debug & 2)
759 			printf("sw_dma_start: adjusted up %d bytes\n", adj);
760 #endif
761 	}
762 
763 	/* We have to frob the address on the "sw". */
764 	dh->dh_startingpa = (dva | 0xF00000);
765 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, (u_int)(dh->dh_startingpa + adj));
766 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, xlen - adj);
767 
768 	/*
769 	 * Acknowledge the phase change.  (After DMA setup!)
770 	 * Put the SBIC into DMA mode, and start the transfer.
771 	 */
772 	if (dh->dh_flags & SIDH_OUT) {
773 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_OUT);
774 		if (adj) {
775 			adjlen = ncr5380_pio_out(ncr_sc, PHASE_DATA_OUT,
776 			    adj, dh->dh_addr);
777 			if (adjlen != adj)
778 				printf("%s: bad outgoing adj, %d != %d\n",
779 				    ncr_sc->sc_dev.dv_xname, adjlen, adj);
780 		}
781 		SCI_CLR_INTR(ncr_sc);
782 		NCR5380_WRITE(ncr_sc, sci_icmd, SCI_ICMD_DATA);
783 		mode = NCR5380_READ(ncr_sc, sci_mode);
784 		mode |= (SCI_MODE_DMA | SCI_MODE_DMA_IE);
785 		NCR5380_WRITE(ncr_sc, sci_mode, mode);
786 		NCR5380_WRITE(ncr_sc, sci_dma_send, 0); 	/* start it */
787 	} else {
788 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_IN);
789 		if (adj) {
790 			adjlen = ncr5380_pio_in(ncr_sc, PHASE_DATA_IN,
791 			    adj, dh->dh_addr);
792 			if (adjlen != adj)
793 				printf("%s: bad incoming adj, %d != %d\n",
794 				    ncr_sc->sc_dev.dv_xname, adjlen, adj);
795 		}
796 		SCI_CLR_INTR(ncr_sc);
797 		NCR5380_WRITE(ncr_sc, sci_icmd, 0);
798 		mode = NCR5380_READ(ncr_sc, sci_mode);
799 		mode |= (SCI_MODE_DMA | SCI_MODE_DMA_IE);
800 		NCR5380_WRITE(ncr_sc, sci_mode, mode);
801 		NCR5380_WRITE(ncr_sc, sci_irecv, 0); 	/* start it */
802 	}
803 
804 	/* Let'er rip! */
805 	csr |= SW_CSR_DMA_EN;
806 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
807 
808 	ncr_sc->sc_state |= NCR_DOINGDMA;
809 
810 #ifdef	DEBUG
811 	if (sw_debug & 2) {
812 		printf("sw_dma_start: started, flags=0x%x\n",
813 		    ncr_sc->sc_state);
814 	}
815 #endif
816 }
817 
818 
819 void
820 sw_dma_eop(ncr_sc)
821 	struct ncr5380_softc *ncr_sc;
822 {
823 
824 	/* Not needed - DMA was stopped prior to examining sci_csr */
825 }
826 
827 #if (defined(DEBUG) || defined(DIAGNOSTIC)) && !defined(COUNT_SW_LEFTOVERS)
828 #define COUNT_SW_LEFTOVERS
829 #endif
830 #ifdef COUNT_SW_LEFTOVERS
831 /*
832  * Let's find out how often these occur.  Read these with DDB from time
833  * to time.
834  */
835 int	sw_3_leftover = 0;
836 int	sw_2_leftover = 0;
837 int	sw_1_leftover = 0;
838 int	sw_0_leftover = 0;
839 #endif
840 
841 void
842 sw_dma_stop(ncr_sc)
843 	struct ncr5380_softc *ncr_sc;
844 {
845 	struct sci_req *sr = ncr_sc->sc_current;
846 	struct sw_dma_handle *dh = sr->sr_dma_hand;
847 	int ntrans = 0, dva;
848 	u_int mode;
849 	u_int32_t csr;
850 
851 	if ((ncr_sc->sc_state & NCR_DOINGDMA) == 0) {
852 #ifdef	DEBUG
853 		printf("sw_dma_stop: dma not running\n");
854 #endif
855 		return;
856 	}
857 	ncr_sc->sc_state &= ~NCR_DOINGDMA;
858 
859 	/* First, halt the DMA engine. */
860 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
861 	csr &= ~SW_CSR_DMA_EN;
862 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
863 
864 	/*
865 	 * XXX HARDWARE BUG!
866 	 * Apparently, some early 4/100 SCSI controllers had a hardware
867 	 * bug that caused the controller to do illegal memory access.
868 	 * We see this as SW_CSR_DMA_BUS_ERR (makes sense).  To work around
869 	 * this, we simply need to clean up after ourselves ... there will
870 	 * be as many as 3 bytes left over.  Since we clean up "left-over"
871 	 * bytes on every read anyway, we just continue to chug along
872 	 * if SW_CSR_DMA_BUS_ERR is asserted.  (This was probably worked
873 	 * around in hardware later with the "left-over byte" indicator
874 	 * in the VME controller.)
875 	 */
876 #if 0
877 	if (csr & (SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR)) {
878 #else
879 	if (csr & (SW_CSR_DMA_CONFLICT)) {
880 #endif
881 		printf("sw: DMA error, csr=0x%x, reset\n", csr);
882 		sr->sr_xs->error = XS_DRIVER_STUFFUP;
883 		ncr_sc->sc_state |= NCR_ABORTING;
884 		sw_reset_adapter(ncr_sc);
885 	}
886 
887 	/* Note that timeout may have set the error flag. */
888 	if (ncr_sc->sc_state & NCR_ABORTING)
889 		goto out;
890 
891 	/*
892 	 * Now try to figure out how much actually transferred
893 	 *
894 	 * The "sw" doesn't have a FIFO or a bcr, so we've stored
895 	 * the starting PA of the transfer in the DMA handle,
896 	 * and subtract it from the ending PA left in the dma_addr
897 	 * register.
898 	 */
899 	dva = SWREG_READ(ncr_sc, SWREG_DMA_ADDR);
900 	ntrans = (dva - dh->dh_startingpa);
901 
902 #ifdef	DEBUG
903 	if (sw_debug & 2) {
904 		printf("sw_dma_stop: ntrans=0x%x\n", ntrans);
905 	}
906 #endif
907 
908 	if (ntrans > ncr_sc->sc_datalen)
909 		panic("sw_dma_stop: excess transfer");
910 
911 	/* Adjust data pointer */
912 	ncr_sc->sc_dataptr += ntrans;
913 	ncr_sc->sc_datalen -= ntrans;
914 
915 	/*
916 	 * After a read, we may need to clean-up
917 	 * "Left-over bytes"  (yuck!)  The "sw" doesn't
918 	 * have a "left-over" indicator, so we have to so
919 	 * this no matter what.  Ick.
920 	 */
921 	if ((dh->dh_flags & SIDH_OUT) == 0) {
922 		char *cp = ncr_sc->sc_dataptr;
923 		u_int32_t bpr;
924 
925 		bpr = SWREG_READ(ncr_sc, SWREG_BPR);
926 
927 		switch (dva & 3) {
928 		case 3:
929 			cp[0] = (bpr & 0xff000000) >> 24;
930 			cp[1] = (bpr & 0x00ff0000) >> 16;
931 			cp[2] = (bpr & 0x0000ff00) >> 8;
932 #ifdef COUNT_SW_LEFTOVERS
933 			++sw_3_leftover;
934 #endif
935 			break;
936 
937 		case 2:
938 			cp[0] = (bpr & 0xff000000) >> 24;
939 			cp[1] = (bpr & 0x00ff0000) >> 16;
940 #ifdef COUNT_SW_LEFTOVERS
941 			++sw_2_leftover;
942 #endif
943 			break;
944 
945 		case 1:
946 			cp[0] = (bpr & 0xff000000) >> 24;
947 #ifdef COUNT_SW_LEFTOVERS
948 			++sw_1_leftover;
949 #endif
950 			break;
951 
952 #ifdef COUNT_SW_LEFTOVERS
953 		default:
954 			++sw_0_leftover;
955 			break;
956 #endif
957 		}
958 	}
959 
960  out:
961 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
962 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
963 
964 	/* Put SBIC back in PIO mode. */
965 	mode = NCR5380_READ(ncr_sc, sci_mode);
966 	mode &= ~(SCI_MODE_DMA | SCI_MODE_DMA_IE);
967 	NCR5380_WRITE(ncr_sc, sci_mode, mode);
968 	NCR5380_WRITE(ncr_sc, sci_icmd, 0);
969 
970 #ifdef DEBUG
971 	if (sw_debug & 2) {
972 		printf("sw_dma_stop: ntrans=0x%x\n", ntrans);
973 	}
974 #endif
975 }
976