xref: /netbsd-src/sys/arch/sparc/dev/sw.c (revision d48f14661dda8638fee055ba15d35bdfb29b9fa8)
1 /*	$NetBSD: sw.c,v 1.17 2006/03/29 04:16:47 thorpej 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 <sys/cdefs.h>
95 __KERNEL_RCSID(0, "$NetBSD: sw.c,v 1.17 2006/03/29 04:16:47 thorpej Exp $");
96 
97 #include "opt_ddb.h"
98 
99 #include <sys/types.h>
100 #include <sys/param.h>
101 #include <sys/systm.h>
102 #include <sys/kernel.h>
103 #include <sys/malloc.h>
104 #include <sys/errno.h>
105 #include <sys/device.h>
106 #include <sys/buf.h>
107 
108 #include <machine/bus.h>
109 #include <machine/intr.h>
110 #include <machine/autoconf.h>
111 
112 #include <dev/scsipi/scsi_all.h>
113 #include <dev/scsipi/scsipi_all.h>
114 #include <dev/scsipi/scsipi_debug.h>
115 #include <dev/scsipi/scsiconf.h>
116 
117 #ifndef DDB
118 #define	Debugger()
119 #endif
120 
121 #ifndef DEBUG
122 #define DEBUG XXX
123 #endif
124 
125 #define COUNT_SW_LEFTOVERS	XXX	/* See sw DMA completion code */
126 
127 #include <dev/ic/ncr5380reg.h>
128 #include <dev/ic/ncr5380var.h>
129 
130 #include <sparc/dev/swreg.h>
131 
132 /*
133  * Transfers smaller than this are done using PIO
134  * (on assumption they're not worth DMA overhead)
135  */
136 #define	MIN_DMA_LEN 128
137 
138 /*
139  * Transfers lager than 65535 bytes need to be split-up.
140  * (Some of the FIFO logic has only 16 bits counters.)
141  * Make the size an integer multiple of the page size
142  * to avoid buf/cluster remap problems.  (paranoid?)
143  */
144 #define	MAX_DMA_LEN 0xE000
145 
146 #ifdef	DEBUG
147 int sw_debug = 0;
148 #endif
149 
150 /*
151  * This structure is used to keep track of mapped DMA requests.
152  */
153 struct sw_dma_handle {
154 	int 		dh_flags;
155 #define	SIDH_BUSY	0x01		/* This DH is in use */
156 #define	SIDH_OUT	0x02		/* DMA does data out (write) */
157 	u_char		*dh_addr;	/* KVA of start of buffer */
158 	int 		dh_maplen;	/* Original data length */
159 	long		dh_startingpa;	/* PA of buffer; for "sw" */
160 	bus_dmamap_t	dh_dmamap;
161 #define dh_dvma	dh_dmamap->dm_segs[0].ds_addr /* VA of buffer in DVMA space */
162 };
163 
164 /*
165  * The first structure member has to be the ncr5380_softc
166  * so we can just cast to go back and fourth between them.
167  */
168 struct sw_softc {
169 	struct ncr5380_softc	ncr_sc;
170 	bus_space_tag_t		sc_bustag;	/* bus tags */
171 	bus_dma_tag_t		sc_dmatag;
172 
173 	struct sw_dma_handle *sc_dma;
174 	int		sc_xlen;	/* length of current DMA segment. */
175 	int		sc_options;	/* options for this instance. */
176 };
177 
178 /*
179  * Options.  By default, DMA is enabled and DMA completion interrupts
180  * and reselect are disabled.  You may enable additional features
181  * the `flags' directive in your kernel's configuration file.
182  *
183  * Alternatively, you can patch your kernel with DDB or some other
184  * mechanism.  The sc_options member of the softc is OR'd with
185  * the value in sw_options.
186  *
187  * On the "sw", interrupts (and thus) reselection don't work, so they're
188  * disabled by default.  DMA is still a little dangerous, too.
189  *
190  * Note, there's a separate sw_options to make life easier.
191  */
192 #define	SW_ENABLE_DMA	0x01	/* Use DMA (maybe polled) */
193 #define	SW_DMA_INTR	0x02	/* DMA completion interrupts */
194 #define	SW_DO_RESELECT	0x04	/* Allow disconnect/reselect */
195 #define	SW_OPTIONS_MASK	(SW_ENABLE_DMA|SW_DMA_INTR|SW_DO_RESELECT)
196 #define SW_OPTIONS_BITS	"\10\3RESELECT\2DMA_INTR\1DMA"
197 int sw_options = SW_ENABLE_DMA;
198 
199 static int	sw_match(struct device *, struct cfdata *, void *);
200 static void	sw_attach(struct device *, struct device *, void *);
201 static int	sw_intr(void *);
202 static void	sw_reset_adapter(struct ncr5380_softc *);
203 static void	sw_minphys(struct buf *);
204 
205 void	sw_dma_alloc(struct ncr5380_softc *);
206 void	sw_dma_free(struct ncr5380_softc *);
207 void	sw_dma_poll(struct ncr5380_softc *);
208 
209 void	sw_dma_setup(struct ncr5380_softc *);
210 void	sw_dma_start(struct ncr5380_softc *);
211 void	sw_dma_eop(struct ncr5380_softc *);
212 void	sw_dma_stop(struct ncr5380_softc *);
213 
214 void	sw_intr_on(struct ncr5380_softc *);
215 void	sw_intr_off(struct ncr5380_softc *);
216 
217 /* Shorthand bus space access */
218 #define SWREG_READ(sc, index) \
219 	bus_space_read_4((sc)->sc_regt, (sc)->sc_regh, index)
220 #define SWREG_WRITE(sc, index, v) \
221 	bus_space_write_4((sc)->sc_regt, (sc)->sc_regh, index, v)
222 
223 
224 /* The Sun "SCSI Weird" 4/100 obio controller. */
225 CFATTACH_DECL(sw, sizeof(struct sw_softc),
226     sw_match, sw_attach, NULL, NULL);
227 
228 static int
229 sw_match(struct device *parent, struct cfdata *cf, void *aux)
230 {
231 	union obio_attach_args *uoba = aux;
232 	struct obio4_attach_args *oba;
233 
234 	/* Nothing but a Sun 4/100 is going to have these devices. */
235 	if (cpuinfo.cpu_type != CPUTYP_4_100)
236 		return (0);
237 
238 	if (uoba->uoba_isobio4 == 0)
239 		return (0);
240 
241 	/* Make sure there is something there... */
242 	oba = &uoba->uoba_oba4;
243 	return (bus_space_probe(oba->oba_bustag, oba->oba_paddr,
244 				1,	/* probe size */
245 				1,	/* offset */
246 				0,	/* flags */
247 				NULL, NULL));
248 }
249 
250 static void
251 sw_attach(struct device *parent, struct device *self, void *aux)
252 {
253 	struct sw_softc *sc = (struct sw_softc *) self;
254 	struct ncr5380_softc *ncr_sc = &sc->ncr_sc;
255 	union obio_attach_args *uoba = aux;
256 	struct obio4_attach_args *oba = &uoba->uoba_oba4;
257 	bus_space_handle_t bh;
258 	char bits[64];
259 	int i;
260 
261 	sc->sc_dmatag = oba->oba_dmatag;
262 
263 	/* Map the controller registers. */
264 	if (bus_space_map(oba->oba_bustag, oba->oba_paddr,
265 			  SWREG_BANK_SZ,
266 			  BUS_SPACE_MAP_LINEAR,
267 			  &bh) != 0) {
268 		printf("%s: cannot map registers\n", self->dv_xname);
269 		return;
270 	}
271 
272 	ncr_sc->sc_regt = oba->oba_bustag;
273 	ncr_sc->sc_regh = bh;
274 
275 	sc->sc_options = sw_options;
276 
277 	ncr_sc->sc_dma_setup = sw_dma_setup;
278 	ncr_sc->sc_dma_start = sw_dma_start;
279 	ncr_sc->sc_dma_eop   = sw_dma_stop;
280 	ncr_sc->sc_dma_stop  = sw_dma_stop;
281 	ncr_sc->sc_intr_on   = sw_intr_on;
282 	ncr_sc->sc_intr_off  = sw_intr_off;
283 
284 	/*
285 	 * Establish interrupt channel.
286 	 * Default interrupt priority always is 3.  At least, that's
287 	 * what my board seems to be at.  --thorpej
288 	 */
289 	if (oba->oba_pri == -1)
290 		oba->oba_pri = 3;
291 
292 	(void)bus_intr_establish(oba->oba_bustag, oba->oba_pri, IPL_BIO,
293 				 sw_intr, sc);
294 
295 	printf(" pri %d\n", oba->oba_pri);
296 
297 
298 	/*
299 	 * Pull in the options flags.  Allow the user to completely
300 	 * override the default values.
301 	 */
302 	if ((device_cfdata(&ncr_sc->sc_dev)->cf_flags & SW_OPTIONS_MASK) != 0)
303 		sc->sc_options =
304 		    device_cfdata(&ncr_sc->sc_dev)->cf_flags & SW_OPTIONS_MASK;
305 
306 	/*
307 	 * Initialize fields used by the MI code
308 	 */
309 
310 	/* NCR5380 register bank offsets */
311 	ncr_sc->sci_r0 = 0;
312 	ncr_sc->sci_r1 = 1;
313 	ncr_sc->sci_r2 = 2;
314 	ncr_sc->sci_r3 = 3;
315 	ncr_sc->sci_r4 = 4;
316 	ncr_sc->sci_r5 = 5;
317 	ncr_sc->sci_r6 = 6;
318 	ncr_sc->sci_r7 = 7;
319 
320 	ncr_sc->sc_rev = NCR_VARIANT_NCR5380;
321 
322 	/*
323 	 * MD function pointers used by the MI code.
324 	 */
325 	ncr_sc->sc_pio_out = ncr5380_pio_out;
326 	ncr_sc->sc_pio_in =  ncr5380_pio_in;
327 	ncr_sc->sc_dma_alloc = sw_dma_alloc;
328 	ncr_sc->sc_dma_free  = sw_dma_free;
329 	ncr_sc->sc_dma_poll  = sw_dma_poll;
330 
331 	ncr_sc->sc_flags = 0;
332 	if ((sc->sc_options & SW_DO_RESELECT) == 0)
333 		ncr_sc->sc_no_disconnect = 0xFF;
334 	if ((sc->sc_options & SW_DMA_INTR) == 0)
335 		ncr_sc->sc_flags |= NCR5380_FORCE_POLLING;
336 	ncr_sc->sc_min_dma_len = MIN_DMA_LEN;
337 
338 
339 	/*
340 	 * Allocate DMA handles.
341 	 */
342 	i = SCI_OPENINGS * sizeof(struct sw_dma_handle);
343 	sc->sc_dma = (struct sw_dma_handle *)malloc(i, M_DEVBUF, M_NOWAIT);
344 	if (sc->sc_dma == NULL)
345 		panic("sw: DMA handle malloc failed");
346 
347 	for (i = 0; i < SCI_OPENINGS; i++) {
348 		sc->sc_dma[i].dh_flags = 0;
349 
350 		/* Allocate a DMA handle */
351 		if (bus_dmamap_create(
352 				sc->sc_dmatag,	/* tag */
353 				MAXPHYS,	/* size */
354 				1,		/* nsegments */
355 				MAXPHYS,	/* maxsegsz */
356 				0,		/* boundary */
357 				BUS_DMA_NOWAIT,
358 				&sc->sc_dma[i].dh_dmamap) != 0) {
359 
360 			printf("%s: DMA buffer map create error\n",
361 				ncr_sc->sc_dev.dv_xname);
362 			return;
363 		}
364 	}
365 
366 	if (sc->sc_options) {
367 		printf("%s: options=%s\n", ncr_sc->sc_dev.dv_xname,
368 			bitmask_snprintf(sc->sc_options, SW_OPTIONS_BITS,
369 			    bits, sizeof(bits)));
370 	}
371 
372 	ncr_sc->sc_channel.chan_id = 7;
373 	ncr_sc->sc_adapter.adapt_minphys = sw_minphys;
374 
375 	/* Initialize sw board */
376 	sw_reset_adapter(ncr_sc);
377 
378 	/* Attach the ncr5380 chip driver */
379 	ncr5380_attach(ncr_sc);
380 }
381 
382 static void
383 sw_minphys(struct buf *bp)
384 {
385 	if (bp->b_bcount > MAX_DMA_LEN) {
386 #ifdef DEBUG
387 		if (sw_debug) {
388 			printf("sw_minphys len = 0x%x.\n", MAX_DMA_LEN);
389 			Debugger();
390 		}
391 #endif
392 		bp->b_bcount = MAX_DMA_LEN;
393 	}
394 	minphys(bp);
395 }
396 
397 #define CSR_WANT (SW_CSR_SBC_IP | SW_CSR_DMA_IP | \
398 	SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR )
399 
400 static int
401 sw_intr(void *arg)
402 {
403 	struct sw_softc *sc = arg;
404 	struct ncr5380_softc *ncr_sc = (struct ncr5380_softc *)arg;
405 	int dma_error, claimed;
406 	u_short csr;
407 
408 	claimed = 0;
409 	dma_error = 0;
410 
411 	/* SBC interrupt? DMA interrupt? */
412 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
413 
414 	NCR_TRACE("sw_intr: csr=0x%x\n", csr);
415 
416 	if (csr & SW_CSR_DMA_CONFLICT) {
417 		dma_error |= SW_CSR_DMA_CONFLICT;
418 		printf("sw_intr: DMA conflict\n");
419 	}
420 	if (csr & SW_CSR_DMA_BUS_ERR) {
421 		dma_error |= SW_CSR_DMA_BUS_ERR;
422 		printf("sw_intr: DMA bus error\n");
423 	}
424 	if (dma_error) {
425 		if (sc->ncr_sc.sc_state & NCR_DOINGDMA)
426 			sc->ncr_sc.sc_state |= NCR_ABORTING;
427 		/* Make sure we will call the main isr. */
428 		csr |= SW_CSR_DMA_IP;
429 	}
430 
431 	if (csr & (SW_CSR_SBC_IP | SW_CSR_DMA_IP)) {
432 		claimed = ncr5380_intr(&sc->ncr_sc);
433 #ifdef DEBUG
434 		if (!claimed) {
435 			printf("sw_intr: spurious from SBC\n");
436 			if (sw_debug & 4) {
437 				Debugger();	/* XXX */
438 			}
439 		}
440 #endif
441 	}
442 
443 	return (claimed);
444 }
445 
446 
447 static void
448 sw_reset_adapter(struct ncr5380_softc *ncr_sc)
449 {
450 
451 #ifdef	DEBUG
452 	if (sw_debug) {
453 		printf("sw_reset_adapter\n");
454 	}
455 #endif
456 
457 	/*
458 	 * The reset bits in the CSR are active low.
459 	 */
460 	SWREG_WRITE(ncr_sc, SWREG_CSR, 0);
461 	delay(10);
462 	SWREG_WRITE(ncr_sc, SWREG_CSR, SW_CSR_SCSI_RES);
463 
464 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
465 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
466 	delay(10);
467 	SWREG_WRITE(ncr_sc, SWREG_CSR, SW_CSR_SCSI_RES | SW_CSR_INTR_EN);
468 
469 	SCI_CLR_INTR(ncr_sc);
470 }
471 
472 
473 /*****************************************************************
474  * Common functions for DMA
475  ****************************************************************/
476 
477 /*
478  * Allocate a DMA handle and put it in sc->sc_dma.  Prepare
479  * for DMA transfer.  On the Sun4, this means mapping the buffer
480  * into DVMA space.
481  */
482 void
483 sw_dma_alloc(struct ncr5380_softc *ncr_sc)
484 {
485 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
486 	struct sci_req *sr = ncr_sc->sc_current;
487 	struct scsipi_xfer *xs = sr->sr_xs;
488 	struct sw_dma_handle *dh;
489 	int i, xlen;
490 	u_long addr;
491 
492 #ifdef DIAGNOSTIC
493 	if (sr->sr_dma_hand != NULL)
494 		panic("sw_dma_alloc: already have DMA handle");
495 #endif
496 
497 #if 1	/* XXX - Temporary */
498 	/* XXX - In case we think DMA is completely broken... */
499 	if ((sc->sc_options & SW_ENABLE_DMA) == 0)
500 		return;
501 #endif
502 
503 	addr = (u_long) ncr_sc->sc_dataptr;
504 	xlen = ncr_sc->sc_datalen;
505 
506 	/* If the DMA start addr is misaligned then do PIO */
507 	if ((addr & 1) || (xlen & 1)) {
508 		printf("sw_dma_alloc: misaligned.\n");
509 		return;
510 	}
511 
512 	/* Make sure our caller checked sc_min_dma_len. */
513 	if (xlen < MIN_DMA_LEN)
514 		panic("sw_dma_alloc: xlen=0x%x", xlen);
515 
516 	/* Find free DMA handle.  Guaranteed to find one since we have
517 	   as many DMA handles as the driver has processes. */
518 	for (i = 0; i < SCI_OPENINGS; i++) {
519 		if ((sc->sc_dma[i].dh_flags & SIDH_BUSY) == 0)
520 			goto found;
521 	}
522 	panic("sw: no free DMA handles.");
523 
524 found:
525 	dh = &sc->sc_dma[i];
526 	dh->dh_flags = SIDH_BUSY;
527 	dh->dh_addr = (u_char *)addr;
528 	dh->dh_maplen  = xlen;
529 
530 	/* Copy the "write" flag for convenience. */
531 	if ((xs->xs_control & XS_CTL_DATA_OUT) != 0)
532 		dh->dh_flags |= SIDH_OUT;
533 
534 	/*
535 	 * Double-map the buffer into DVMA space.  If we can't re-map
536 	 * the buffer, we print a warning and fall back to PIO mode.
537 	 *
538 	 * NOTE: it is not safe to sleep here!
539 	 */
540 	if (bus_dmamap_load(sc->sc_dmatag, dh->dh_dmamap,
541 			    (caddr_t)addr, xlen, NULL, BUS_DMA_NOWAIT) != 0) {
542 		/* Can't remap segment */
543 		printf("sw_dma_alloc: can't remap 0x%lx/0x%x, doing PIO\n",
544 			addr, dh->dh_maplen);
545 		dh->dh_flags = 0;
546 		return;
547 	}
548 	bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap, addr, xlen,
549 			(dh->dh_flags & SIDH_OUT)
550 				? BUS_DMASYNC_PREWRITE
551 				: BUS_DMASYNC_PREREAD);
552 
553 	/* success */
554 	sr->sr_dma_hand = dh;
555 
556 	return;
557 }
558 
559 
560 void
561 sw_dma_free(struct ncr5380_softc *ncr_sc)
562 {
563 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
564 	struct sci_req *sr = ncr_sc->sc_current;
565 	struct sw_dma_handle *dh = sr->sr_dma_hand;
566 
567 #ifdef DIAGNOSTIC
568 	if (dh == NULL)
569 		panic("sw_dma_free: no DMA handle");
570 #endif
571 
572 	if (ncr_sc->sc_state & NCR_DOINGDMA)
573 		panic("sw_dma_free: free while in progress");
574 
575 	if (dh->dh_flags & SIDH_BUSY) {
576 		/* Give back the DVMA space. */
577 		bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap,
578 				dh->dh_dvma, dh->dh_maplen,
579 				(dh->dh_flags & SIDH_OUT)
580 					? BUS_DMASYNC_POSTWRITE
581 					: BUS_DMASYNC_POSTREAD);
582 		bus_dmamap_unload(sc->sc_dmatag, dh->dh_dmamap);
583 		dh->dh_flags = 0;
584 	}
585 	sr->sr_dma_hand = NULL;
586 }
587 
588 
589 /*
590  * Poll (spin-wait) for DMA completion.
591  * Called right after xx_dma_start(), and
592  * xx_dma_stop() will be called next.
593  * Same for either VME or OBIO.
594  */
595 void
596 sw_dma_poll(struct ncr5380_softc *ncr_sc)
597 {
598 	struct sci_req *sr = ncr_sc->sc_current;
599 	int tmo, csr_mask, csr;
600 
601 	/* Make sure DMA started successfully. */
602 	if (ncr_sc->sc_state & NCR_ABORTING)
603 		return;
604 
605 	csr_mask = SW_CSR_SBC_IP | SW_CSR_DMA_IP |
606 		SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR;
607 
608 	tmo = 50000;	/* X100 = 5 sec. */
609 	for (;;) {
610 		csr = SWREG_READ(ncr_sc, SWREG_CSR);
611 		if (csr & csr_mask)
612 			break;
613 		if (--tmo <= 0) {
614 			printf("%s: DMA timeout (while polling)\n",
615 			    ncr_sc->sc_dev.dv_xname);
616 			/* Indicate timeout as MI code would. */
617 			sr->sr_flags |= SR_OVERDUE;
618 			break;
619 		}
620 		delay(100);
621 	}
622 
623 #ifdef	DEBUG
624 	if (sw_debug) {
625 		printf("sw_dma_poll: done, csr=0x%x\n", csr);
626 	}
627 #endif
628 }
629 
630 
631 /*
632  * This is called when the bus is going idle,
633  * so we want to enable the SBC interrupts.
634  * That is controlled by the DMA enable!
635  * Who would have guessed!
636  * What a NASTY trick!
637  *
638  * XXX THIS MIGHT NOT WORK RIGHT!
639  */
640 void
641 sw_intr_on(struct ncr5380_softc *ncr_sc)
642 {
643 	uint32_t csr;
644 
645 	sw_dma_setup(ncr_sc);
646 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
647 	csr |= SW_CSR_DMA_EN;	/* XXX - this bit is for vme only?! */
648 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
649 }
650 
651 /*
652  * This is called when the bus is idle and we are
653  * about to start playing with the SBC chip.
654  *
655  * XXX THIS MIGHT NOT WORK RIGHT!
656  */
657 void
658 sw_intr_off(struct ncr5380_softc *ncr_sc)
659 {
660 	uint32_t csr;
661 
662 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
663 	csr &= ~SW_CSR_DMA_EN;
664 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
665 }
666 
667 
668 /*
669  * This function is called during the COMMAND or MSG_IN phase
670  * that precedes a DATA_IN or DATA_OUT phase, in case we need
671  * to setup the DMA engine before the bus enters a DATA phase.
672  *
673  * On the OBIO version we just clear the DMA count and address
674  * here (to make sure it stays idle) and do the real setup
675  * later, in dma_start.
676  */
677 void
678 sw_dma_setup(struct ncr5380_softc *ncr_sc)
679 {
680 	uint32_t csr;
681 
682 	/* No FIFO to reset on "sw". */
683 
684 	/* Set direction (assume recv here) */
685 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
686 	csr &= ~SW_CSR_SEND;
687 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
688 
689 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
690 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
691 }
692 
693 
694 void
695 sw_dma_start(struct ncr5380_softc *ncr_sc)
696 {
697 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
698 	struct sci_req *sr = ncr_sc->sc_current;
699 	struct sw_dma_handle *dh = sr->sr_dma_hand;
700 	u_long dva;
701 	int xlen, adj, adjlen;
702 	u_int mode;
703 	uint32_t csr;
704 
705 	/*
706 	 * Get the DVMA mapping for this segment.
707 	 */
708 	dva = (u_long)(dh->dh_dvma);
709 	if (dva & 1)
710 		panic("sw_dma_start: bad dva=0x%lx", dva);
711 
712 	xlen = ncr_sc->sc_datalen;
713 	xlen &= ~1;
714 	sc->sc_xlen = xlen;	/* XXX: or less... */
715 
716 #ifdef	DEBUG
717 	if (sw_debug & 2) {
718 		printf("sw_dma_start: dh=%p, dva=0x%lx, xlen=%d\n",
719 		    dh, dva, xlen);
720 	}
721 #endif
722 
723 	/*
724 	 * Set up the DMA controller.
725 	 * Note that (dh->dh_len < sc_datalen)
726 	 */
727 
728 	/* Set direction (send/recv) */
729 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
730 	if (dh->dh_flags & SIDH_OUT) {
731 		csr |= SW_CSR_SEND;
732 	} else {
733 		csr &= ~SW_CSR_SEND;
734 	}
735 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
736 
737 	/*
738 	 * The "sw" needs longword aligned transfers.  We
739 	 * detect a shortword aligned transfer here, and adjust the
740 	 * DMA transfer by 2 bytes.  These two bytes are read/written
741 	 * in PIO mode just before the DMA is started.
742 	 */
743 	adj = 0;
744 	if (dva & 2) {
745 		adj = 2;
746 #ifdef DEBUG
747 		if (sw_debug & 2)
748 			printf("sw_dma_start: adjusted up %d bytes\n", adj);
749 #endif
750 	}
751 
752 	/* We have to frob the address on the "sw". */
753 	dh->dh_startingpa = (dva | 0xF00000);
754 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, (u_int)(dh->dh_startingpa + adj));
755 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, xlen - adj);
756 
757 	/*
758 	 * Acknowledge the phase change.  (After DMA setup!)
759 	 * Put the SBIC into DMA mode, and start the transfer.
760 	 */
761 	if (dh->dh_flags & SIDH_OUT) {
762 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_OUT);
763 		if (adj) {
764 			adjlen = ncr5380_pio_out(ncr_sc, PHASE_DATA_OUT,
765 			    adj, dh->dh_addr);
766 			if (adjlen != adj)
767 				printf("%s: bad outgoing adj, %d != %d\n",
768 				    ncr_sc->sc_dev.dv_xname, adjlen, adj);
769 		}
770 		SCI_CLR_INTR(ncr_sc);
771 		NCR5380_WRITE(ncr_sc, sci_icmd, SCI_ICMD_DATA);
772 		mode = NCR5380_READ(ncr_sc, sci_mode);
773 		mode |= (SCI_MODE_DMA | SCI_MODE_DMA_IE);
774 		NCR5380_WRITE(ncr_sc, sci_mode, mode);
775 		NCR5380_WRITE(ncr_sc, sci_dma_send, 0); 	/* start it */
776 	} else {
777 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_IN);
778 		if (adj) {
779 			adjlen = ncr5380_pio_in(ncr_sc, PHASE_DATA_IN,
780 			    adj, dh->dh_addr);
781 			if (adjlen != adj)
782 				printf("%s: bad incoming adj, %d != %d\n",
783 				    ncr_sc->sc_dev.dv_xname, adjlen, adj);
784 		}
785 		SCI_CLR_INTR(ncr_sc);
786 		NCR5380_WRITE(ncr_sc, sci_icmd, 0);
787 		mode = NCR5380_READ(ncr_sc, sci_mode);
788 		mode |= (SCI_MODE_DMA | SCI_MODE_DMA_IE);
789 		NCR5380_WRITE(ncr_sc, sci_mode, mode);
790 		NCR5380_WRITE(ncr_sc, sci_irecv, 0); 	/* start it */
791 	}
792 
793 	/* Let'er rip! */
794 	csr |= SW_CSR_DMA_EN;
795 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
796 
797 	ncr_sc->sc_state |= NCR_DOINGDMA;
798 
799 #ifdef	DEBUG
800 	if (sw_debug & 2) {
801 		printf("sw_dma_start: started, flags=0x%x\n",
802 		    ncr_sc->sc_state);
803 	}
804 #endif
805 }
806 
807 
808 void
809 sw_dma_eop(struct ncr5380_softc *ncr_sc)
810 {
811 
812 	/* Not needed - DMA was stopped prior to examining sci_csr */
813 }
814 
815 #if (defined(DEBUG) || defined(DIAGNOSTIC)) && !defined(COUNT_SW_LEFTOVERS)
816 #define COUNT_SW_LEFTOVERS
817 #endif
818 #ifdef COUNT_SW_LEFTOVERS
819 /*
820  * Let's find out how often these occur.  Read these with DDB from time
821  * to time.
822  */
823 int	sw_3_leftover = 0;
824 int	sw_2_leftover = 0;
825 int	sw_1_leftover = 0;
826 int	sw_0_leftover = 0;
827 #endif
828 
829 void
830 sw_dma_stop(struct ncr5380_softc *ncr_sc)
831 {
832 	struct sci_req *sr = ncr_sc->sc_current;
833 	struct sw_dma_handle *dh = sr->sr_dma_hand;
834 	int ntrans = 0, dva;
835 	u_int mode;
836 	uint32_t csr;
837 
838 	if ((ncr_sc->sc_state & NCR_DOINGDMA) == 0) {
839 #ifdef	DEBUG
840 		printf("sw_dma_stop: DMA not running\n");
841 #endif
842 		return;
843 	}
844 	ncr_sc->sc_state &= ~NCR_DOINGDMA;
845 
846 	/* First, halt the DMA engine. */
847 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
848 	csr &= ~SW_CSR_DMA_EN;
849 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
850 
851 	/*
852 	 * XXX HARDWARE BUG!
853 	 * Apparently, some early 4/100 SCSI controllers had a hardware
854 	 * bug that caused the controller to do illegal memory access.
855 	 * We see this as SW_CSR_DMA_BUS_ERR (makes sense).  To work around
856 	 * this, we simply need to clean up after ourselves ... there will
857 	 * be as many as 3 bytes left over.  Since we clean up "left-over"
858 	 * bytes on every read anyway, we just continue to chug along
859 	 * if SW_CSR_DMA_BUS_ERR is asserted.  (This was probably worked
860 	 * around in hardware later with the "left-over byte" indicator
861 	 * in the VME controller.)
862 	 */
863 #if 0
864 	if (csr & (SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR))
865 #else
866 	if (csr & (SW_CSR_DMA_CONFLICT))
867 #endif
868 	{
869 		printf("sw: DMA error, csr=0x%x, reset\n", csr);
870 		sr->sr_xs->error = XS_DRIVER_STUFFUP;
871 		ncr_sc->sc_state |= NCR_ABORTING;
872 		sw_reset_adapter(ncr_sc);
873 	}
874 
875 	/* Note that timeout may have set the error flag. */
876 	if (ncr_sc->sc_state & NCR_ABORTING)
877 		goto out;
878 
879 	/*
880 	 * Now try to figure out how much actually transferred
881 	 *
882 	 * The "sw" doesn't have a FIFO or a bcr, so we've stored
883 	 * the starting PA of the transfer in the DMA handle,
884 	 * and subtract it from the ending PA left in the dma_addr
885 	 * register.
886 	 */
887 	dva = SWREG_READ(ncr_sc, SWREG_DMA_ADDR);
888 	ntrans = (dva - dh->dh_startingpa);
889 
890 #ifdef	DEBUG
891 	if (sw_debug & 2) {
892 		printf("sw_dma_stop: ntrans=0x%x\n", ntrans);
893 	}
894 #endif
895 
896 	if (ntrans > ncr_sc->sc_datalen)
897 		panic("sw_dma_stop: excess transfer");
898 
899 	/* Adjust data pointer */
900 	ncr_sc->sc_dataptr += ntrans;
901 	ncr_sc->sc_datalen -= ntrans;
902 
903 	/*
904 	 * After a read, we may need to clean-up
905 	 * "Left-over bytes"  (yuck!)  The "sw" doesn't
906 	 * have a "left-over" indicator, so we have to so
907 	 * this no matter what.  Ick.
908 	 */
909 	if ((dh->dh_flags & SIDH_OUT) == 0) {
910 		char *cp = ncr_sc->sc_dataptr;
911 		uint32_t bpr;
912 
913 		bpr = SWREG_READ(ncr_sc, SWREG_BPR);
914 
915 		switch (dva & 3) {
916 		case 3:
917 			cp[0] = (bpr & 0xff000000) >> 24;
918 			cp[1] = (bpr & 0x00ff0000) >> 16;
919 			cp[2] = (bpr & 0x0000ff00) >> 8;
920 #ifdef COUNT_SW_LEFTOVERS
921 			++sw_3_leftover;
922 #endif
923 			break;
924 
925 		case 2:
926 			cp[0] = (bpr & 0xff000000) >> 24;
927 			cp[1] = (bpr & 0x00ff0000) >> 16;
928 #ifdef COUNT_SW_LEFTOVERS
929 			++sw_2_leftover;
930 #endif
931 			break;
932 
933 		case 1:
934 			cp[0] = (bpr & 0xff000000) >> 24;
935 #ifdef COUNT_SW_LEFTOVERS
936 			++sw_1_leftover;
937 #endif
938 			break;
939 
940 #ifdef COUNT_SW_LEFTOVERS
941 		default:
942 			++sw_0_leftover;
943 			break;
944 #endif
945 		}
946 	}
947 
948  out:
949 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
950 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
951 
952 	/* Put SBIC back in PIO mode. */
953 	mode = NCR5380_READ(ncr_sc, sci_mode);
954 	mode &= ~(SCI_MODE_DMA | SCI_MODE_DMA_IE);
955 	NCR5380_WRITE(ncr_sc, sci_mode, mode);
956 	NCR5380_WRITE(ncr_sc, sci_icmd, 0);
957 
958 #ifdef DEBUG
959 	if (sw_debug & 2) {
960 		printf("sw_dma_stop: ntrans=0x%x\n", ntrans);
961 	}
962 #endif
963 }
964