xref: /netbsd-src/sys/arch/sparc/dev/sw.c (revision 481fca6e59249d8ffcf24fef7cfbe7b131bfb080)
1 /*	$NetBSD: sw.c,v 1.3 2000/07/09 20:57:47 pk 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 static int sw_link_flags = 0 /* | SDEV_DB2 */ ;
146 #endif
147 
148 /*
149  * This structure is used to keep track of mapped DMA requests.
150  */
151 struct sw_dma_handle {
152 	int 		dh_flags;
153 #define	SIDH_BUSY	0x01		/* This DH is in use */
154 #define	SIDH_OUT	0x02		/* DMA does data out (write) */
155 	u_char		*dh_addr;	/* KVA of start of buffer */
156 	int 		dh_maplen;	/* Original data length */
157 	long		dh_startingpa;	/* PA of buffer; for "sw" */
158 	bus_dmamap_t	dh_dmamap;
159 #define dh_dvma	dh_dmamap->dm_segs[0].ds_addr /* VA of buffer in DVMA space */
160 };
161 
162 /*
163  * The first structure member has to be the ncr5380_softc
164  * so we can just cast to go back and fourth between them.
165  */
166 struct sw_softc {
167 	struct ncr5380_softc	ncr_sc;
168 	bus_space_tag_t		sc_bustag;	/* bus tags */
169 	bus_dma_tag_t		sc_dmatag;
170 
171 	struct sw_dma_handle *sc_dma;
172 	int		sc_xlen;	/* length of current DMA segment. */
173 	int		sc_options;	/* options for this instance. */
174 };
175 
176 /*
177  * Options.  By default, DMA is enabled and DMA completion interrupts
178  * and reselect are disabled.  You may enable additional features
179  * the `flags' directive in your kernel's configuration file.
180  *
181  * Alternatively, you can patch your kernel with DDB or some other
182  * mechanism.  The sc_options member of the softc is OR'd with
183  * the value in sw_options.
184  *
185  * On the "sw", interrupts (and thus) reselection don't work, so they're
186  * disabled by default.  DMA is still a little dangerous, too.
187  *
188  * Note, there's a separate sw_options to make life easier.
189  */
190 #define	SW_ENABLE_DMA	0x01	/* Use DMA (maybe polled) */
191 #define	SW_DMA_INTR	0x02	/* DMA completion interrupts */
192 #define	SW_DO_RESELECT	0x04	/* Allow disconnect/reselect */
193 #define	SW_OPTIONS_MASK	(SW_ENABLE_DMA|SW_DMA_INTR|SW_DO_RESELECT)
194 #define SW_OPTIONS_BITS	"\10\3RESELECT\2DMA_INTR\1DMA"
195 int sw_options = SW_ENABLE_DMA;
196 
197 static int	sw_match __P((struct device *, struct cfdata *, void *));
198 static void	sw_attach __P((struct device *, struct device *, void *));
199 static int	sw_intr __P((void *));
200 static void	sw_reset_adapter __P((struct ncr5380_softc *));
201 static void	sw_minphys __P((struct buf *));
202 
203 void	sw_dma_alloc __P((struct ncr5380_softc *));
204 void	sw_dma_free __P((struct ncr5380_softc *));
205 void	sw_dma_poll __P((struct ncr5380_softc *));
206 
207 void	sw_dma_setup __P((struct ncr5380_softc *));
208 void	sw_dma_start __P((struct ncr5380_softc *));
209 void	sw_dma_eop __P((struct ncr5380_softc *));
210 void	sw_dma_stop __P((struct ncr5380_softc *));
211 
212 void	sw_intr_on __P((struct ncr5380_softc *));
213 void	sw_intr_off __P((struct ncr5380_softc *));
214 
215 /* Shorthand bus space access */
216 #define SWREG_READ(sc, index) \
217 	bus_space_read_4((sc)->sc_regt, (sc)->sc_regh, index)
218 #define SWREG_WRITE(sc, index, v) \
219 	bus_space_write_4((sc)->sc_regt, (sc)->sc_regh, index, v)
220 
221 
222 /* The Sun "SCSI Weird" 4/100 obio controller. */
223 struct cfattach sw_ca = {
224 	sizeof(struct sw_softc), sw_match, sw_attach
225 };
226 
227 static int
228 sw_match(parent, cf, aux)
229 	struct device	*parent;
230 	struct cfdata *cf;
231 	void *aux;
232 {
233 	union obio_attach_args *uoba = aux;
234 	struct obio4_attach_args *oba;
235 
236 	/* Nothing but a Sun 4/100 is going to have these devices. */
237 	if (cpuinfo.cpu_type != CPUTYP_4_100)
238 		return (0);
239 
240 	if (uoba->uoba_isobio4 == 0)
241 		return (0);
242 
243 	/* Make sure there is something there... */
244 	oba = &uoba->uoba_oba4;
245 	return (bus_space_probe(oba->oba_bustag, 0, oba->oba_paddr,
246 				1,	/* probe size */
247 				1,	/* offset */
248 				0,	/* flags */
249 				NULL, NULL));
250 }
251 
252 static void
253 sw_attach(parent, self, aux)
254 	struct device	*parent, *self;
255 	void		*aux;
256 {
257 	struct sw_softc *sc = (struct sw_softc *) self;
258 	struct ncr5380_softc *ncr_sc = &sc->ncr_sc;
259 	union obio_attach_args *uoba = aux;
260 	struct obio4_attach_args *oba = &uoba->uoba_oba4;
261 	bus_space_handle_t bh;
262 	char bits[64];
263 	int i;
264 
265 	sc->sc_dmatag = oba->oba_dmatag;
266 
267 	/* Map the controller registers. */
268 	if (obio_bus_map(oba->oba_bustag, oba->oba_paddr,
269 			 0,
270 			 SWREG_BANK_SZ,
271 			 BUS_SPACE_MAP_LINEAR,
272 			 0, &bh) != 0) {
273 		printf("%s: cannot map registers\n", self->dv_xname);
274 		return;
275 	}
276 
277 	ncr_sc->sc_regt = oba->oba_bustag;
278 	ncr_sc->sc_regh = bh;
279 
280 	sc->sc_options = sw_options;
281 
282 	ncr_sc->sc_dma_setup = sw_dma_setup;
283 	ncr_sc->sc_dma_start = sw_dma_start;
284 	ncr_sc->sc_dma_eop   = sw_dma_stop;
285 	ncr_sc->sc_dma_stop  = sw_dma_stop;
286 	ncr_sc->sc_intr_on   = sw_intr_on;
287 	ncr_sc->sc_intr_off  = sw_intr_off;
288 
289 	/*
290 	 * Establish interrupt channel.
291 	 * Default interrupt priority always is 3.  At least, that's
292 	 * what my board seems to be at.  --thorpej
293 	 */
294 	if (oba->oba_pri == -1)
295 		oba->oba_pri = 3;
296 
297 	(void)bus_intr_establish(oba->oba_bustag, oba->oba_pri, IPL_BIO, 0,
298 				 sw_intr, sc);
299 
300 	printf(" pri %d\n", oba->oba_pri);
301 
302 
303 	/*
304 	 * Pull in the options flags.  Allow the user to completely
305 	 * override the default values.
306 	 */
307 	if ((ncr_sc->sc_dev.dv_cfdata->cf_flags & SW_OPTIONS_MASK) != 0)
308 		sc->sc_options =
309 		    (ncr_sc->sc_dev.dv_cfdata->cf_flags & SW_OPTIONS_MASK);
310 
311 	/*
312 	 * Initialize fields used by the MI code
313 	 */
314 
315 	/* NCR5380 register bank offsets */
316 	ncr_sc->sci_r0 = 0;
317 	ncr_sc->sci_r1 = 1;
318 	ncr_sc->sci_r2 = 2;
319 	ncr_sc->sci_r3 = 3;
320 	ncr_sc->sci_r4 = 4;
321 	ncr_sc->sci_r5 = 5;
322 	ncr_sc->sci_r6 = 6;
323 	ncr_sc->sci_r7 = 7;
324 
325 	ncr_sc->sc_rev = NCR_VARIANT_NCR5380;
326 
327 	/*
328 	 * MD function pointers used by the MI code.
329 	 */
330 	ncr_sc->sc_pio_out = ncr5380_pio_out;
331 	ncr_sc->sc_pio_in =  ncr5380_pio_in;
332 	ncr_sc->sc_dma_alloc = sw_dma_alloc;
333 	ncr_sc->sc_dma_free  = sw_dma_free;
334 	ncr_sc->sc_dma_poll  = sw_dma_poll;
335 
336 	ncr_sc->sc_flags = 0;
337 	if ((sc->sc_options & SW_DO_RESELECT) == 0)
338 		ncr_sc->sc_no_disconnect = 0xFF;
339 	if ((sc->sc_options & SW_DMA_INTR) == 0)
340 		ncr_sc->sc_flags |= NCR5380_FORCE_POLLING;
341 	ncr_sc->sc_min_dma_len = MIN_DMA_LEN;
342 
343 
344 	/*
345 	 * Allocate DMA handles.
346 	 */
347 	i = SCI_OPENINGS * sizeof(struct sw_dma_handle);
348 	sc->sc_dma = (struct sw_dma_handle *)malloc(i, M_DEVBUF, M_NOWAIT);
349 	if (sc->sc_dma == NULL)
350 		panic("sw: dma handle malloc failed\n");
351 
352 	for (i = 0; i < SCI_OPENINGS; i++) {
353 		sc->sc_dma[i].dh_flags = 0;
354 
355 		/* Allocate a DMA handle */
356 		if (bus_dmamap_create(
357 				sc->sc_dmatag,	/* tag */
358 				MAXPHYS,	/* size */
359 				1,		/* nsegments */
360 				MAXPHYS,	/* maxsegsz */
361 				0,		/* boundary */
362 				BUS_DMA_NOWAIT,
363 				&sc->sc_dma[i].dh_dmamap) != 0) {
364 
365 			printf("%s: DMA buffer map create error\n",
366 				ncr_sc->sc_dev.dv_xname);
367 			return;
368 		}
369 	}
370 
371 	if (sc->sc_options) {
372 		printf("%s: options=%s\n", ncr_sc->sc_dev.dv_xname,
373 			bitmask_snprintf(sc->sc_options, SW_OPTIONS_BITS,
374 			    bits, sizeof(bits)));
375 	}
376 #ifdef	DEBUG
377 	ncr_sc->sc_link.flags |= sw_link_flags;
378 #endif
379 
380 	ncr_sc->sc_link.scsipi_scsi.adapter_target = 7;
381 	ncr_sc->sc_adapter.scsipi_minphys = sw_minphys;
382 
383 	/* Initialize sw board */
384 	sw_reset_adapter(ncr_sc);
385 
386 	/* Attach the ncr5380 chip driver */
387 	ncr5380_attach(ncr_sc);
388 }
389 
390 static void
391 sw_minphys(struct buf *bp)
392 {
393 	if (bp->b_bcount > MAX_DMA_LEN) {
394 #ifdef DEBUG
395 		if (sw_debug) {
396 			printf("sw_minphys len = 0x%x.\n", MAX_DMA_LEN);
397 			Debugger();
398 		}
399 #endif
400 		bp->b_bcount = MAX_DMA_LEN;
401 	}
402 	return (minphys(bp));
403 }
404 
405 #define CSR_WANT (SW_CSR_SBC_IP | SW_CSR_DMA_IP | \
406 	SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR )
407 
408 static int
409 sw_intr(void *arg)
410 {
411 	struct sw_softc *sc = arg;
412 	struct ncr5380_softc *ncr_sc = (struct ncr5380_softc *)arg;
413 	int dma_error, claimed;
414 	u_short csr;
415 
416 	claimed = 0;
417 	dma_error = 0;
418 
419 	/* SBC interrupt? DMA interrupt? */
420 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
421 
422 	NCR_TRACE("sw_intr: csr=0x%x\n", csr);
423 
424 	if (csr & SW_CSR_DMA_CONFLICT) {
425 		dma_error |= SW_CSR_DMA_CONFLICT;
426 		printf("sw_intr: DMA conflict\n");
427 	}
428 	if (csr & SW_CSR_DMA_BUS_ERR) {
429 		dma_error |= SW_CSR_DMA_BUS_ERR;
430 		printf("sw_intr: DMA bus error\n");
431 	}
432 	if (dma_error) {
433 		if (sc->ncr_sc.sc_state & NCR_DOINGDMA)
434 			sc->ncr_sc.sc_state |= NCR_ABORTING;
435 		/* Make sure we will call the main isr. */
436 		csr |= SW_CSR_DMA_IP;
437 	}
438 
439 	if (csr & (SW_CSR_SBC_IP | SW_CSR_DMA_IP)) {
440 		claimed = ncr5380_intr(&sc->ncr_sc);
441 #ifdef DEBUG
442 		if (!claimed) {
443 			printf("sw_intr: spurious from SBC\n");
444 			if (sw_debug & 4) {
445 				Debugger();	/* XXX */
446 			}
447 		}
448 #endif
449 	}
450 
451 	return (claimed);
452 }
453 
454 
455 static void
456 sw_reset_adapter(struct ncr5380_softc *ncr_sc)
457 {
458 
459 #ifdef	DEBUG
460 	if (sw_debug) {
461 		printf("sw_reset_adapter\n");
462 	}
463 #endif
464 
465 	/*
466 	 * The reset bits in the CSR are active low.
467 	 */
468 	SWREG_WRITE(ncr_sc, SWREG_CSR, 0);
469 	delay(10);
470 	SWREG_WRITE(ncr_sc, SWREG_CSR, SW_CSR_SCSI_RES);
471 
472 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
473 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
474 	delay(10);
475 	SWREG_WRITE(ncr_sc, SWREG_CSR, SW_CSR_SCSI_RES | SW_CSR_INTR_EN);
476 
477 	SCI_CLR_INTR(ncr_sc);
478 }
479 
480 
481 /*****************************************************************
482  * Common functions for DMA
483  ****************************************************************/
484 
485 /*
486  * Allocate a DMA handle and put it in sc->sc_dma.  Prepare
487  * for DMA transfer.  On the Sun4, this means mapping the buffer
488  * into DVMA space.
489  */
490 void
491 sw_dma_alloc(ncr_sc)
492 	struct ncr5380_softc *ncr_sc;
493 {
494 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
495 	struct sci_req *sr = ncr_sc->sc_current;
496 	struct scsipi_xfer *xs = sr->sr_xs;
497 	struct sw_dma_handle *dh;
498 	int i, xlen;
499 	u_long addr;
500 
501 #ifdef DIAGNOSTIC
502 	if (sr->sr_dma_hand != NULL)
503 		panic("sw_dma_alloc: already have DMA handle");
504 #endif
505 
506 #if 1	/* XXX - Temporary */
507 	/* XXX - In case we think DMA is completely broken... */
508 	if ((sc->sc_options & SW_ENABLE_DMA) == 0)
509 		return;
510 #endif
511 
512 	addr = (u_long) ncr_sc->sc_dataptr;
513 	xlen = ncr_sc->sc_datalen;
514 
515 	/* If the DMA start addr is misaligned then do PIO */
516 	if ((addr & 1) || (xlen & 1)) {
517 		printf("sw_dma_alloc: misaligned.\n");
518 		return;
519 	}
520 
521 	/* Make sure our caller checked sc_min_dma_len. */
522 	if (xlen < MIN_DMA_LEN)
523 		panic("sw_dma_alloc: xlen=0x%x\n", xlen);
524 
525 	/* Find free DMA handle.  Guaranteed to find one since we have
526 	   as many DMA handles as the driver has processes. */
527 	for (i = 0; i < SCI_OPENINGS; i++) {
528 		if ((sc->sc_dma[i].dh_flags & SIDH_BUSY) == 0)
529 			goto found;
530 	}
531 	panic("sw: no free DMA handles.");
532 
533 found:
534 	dh = &sc->sc_dma[i];
535 	dh->dh_flags = SIDH_BUSY;
536 	dh->dh_addr = (u_char *)addr;
537 	dh->dh_maplen  = xlen;
538 
539 	/* Copy the "write" flag for convenience. */
540 	if ((xs->xs_control & XS_CTL_DATA_OUT) != 0)
541 		dh->dh_flags |= SIDH_OUT;
542 
543 	/*
544 	 * Double-map the buffer into DVMA space.  If we can't re-map
545 	 * the buffer, we print a warning and fall back to PIO mode.
546 	 *
547 	 * NOTE: it is not safe to sleep here!
548 	 */
549 	if (bus_dmamap_load(sc->sc_dmatag, dh->dh_dmamap,
550 			    (caddr_t)addr, xlen, NULL, BUS_DMA_NOWAIT) != 0) {
551 		/* Can't remap segment */
552 		printf("sw_dma_alloc: can't remap 0x%lx/0x%x, doing PIO\n",
553 			addr, dh->dh_maplen);
554 		dh->dh_flags = 0;
555 		return;
556 	}
557 	bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap, addr, xlen,
558 			(dh->dh_flags & SIDH_OUT)
559 				? BUS_DMASYNC_PREWRITE
560 				: BUS_DMASYNC_PREREAD);
561 
562 	/* success */
563 	sr->sr_dma_hand = dh;
564 
565 	return;
566 }
567 
568 
569 void
570 sw_dma_free(ncr_sc)
571 	struct ncr5380_softc *ncr_sc;
572 {
573 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
574 	struct sci_req *sr = ncr_sc->sc_current;
575 	struct sw_dma_handle *dh = sr->sr_dma_hand;
576 
577 #ifdef DIAGNOSTIC
578 	if (dh == NULL)
579 		panic("sw_dma_free: no DMA handle");
580 #endif
581 
582 	if (ncr_sc->sc_state & NCR_DOINGDMA)
583 		panic("sw_dma_free: free while in progress");
584 
585 	if (dh->dh_flags & SIDH_BUSY) {
586 		/* Give back the DVMA space. */
587 		bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap,
588 				dh->dh_dvma, dh->dh_maplen,
589 				(dh->dh_flags & SIDH_OUT)
590 					? BUS_DMASYNC_POSTWRITE
591 					: BUS_DMASYNC_POSTREAD);
592 		bus_dmamap_unload(sc->sc_dmatag, dh->dh_dmamap);
593 		dh->dh_flags = 0;
594 	}
595 	sr->sr_dma_hand = NULL;
596 }
597 
598 
599 /*
600  * Poll (spin-wait) for DMA completion.
601  * Called right after xx_dma_start(), and
602  * xx_dma_stop() will be called next.
603  * Same for either VME or OBIO.
604  */
605 void
606 sw_dma_poll(ncr_sc)
607 	struct ncr5380_softc *ncr_sc;
608 {
609 	struct sci_req *sr = ncr_sc->sc_current;
610 	int tmo, csr_mask, csr;
611 
612 	/* Make sure DMA started successfully. */
613 	if (ncr_sc->sc_state & NCR_ABORTING)
614 		return;
615 
616 	csr_mask = SW_CSR_SBC_IP | SW_CSR_DMA_IP |
617 		SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR;
618 
619 	tmo = 50000;	/* X100 = 5 sec. */
620 	for (;;) {
621 		csr = SWREG_READ(ncr_sc, SWREG_CSR);
622 		if (csr & csr_mask)
623 			break;
624 		if (--tmo <= 0) {
625 			printf("%s: DMA timeout (while polling)\n",
626 			    ncr_sc->sc_dev.dv_xname);
627 			/* Indicate timeout as MI code would. */
628 			sr->sr_flags |= SR_OVERDUE;
629 			break;
630 		}
631 		delay(100);
632 	}
633 
634 #ifdef	DEBUG
635 	if (sw_debug) {
636 		printf("sw_dma_poll: done, csr=0x%x\n", csr);
637 	}
638 #endif
639 }
640 
641 
642 /*
643  * This is called when the bus is going idle,
644  * so we want to enable the SBC interrupts.
645  * That is controlled by the DMA enable!
646  * Who would have guessed!
647  * What a NASTY trick!
648  *
649  * XXX THIS MIGHT NOT WORK RIGHT!
650  */
651 void
652 sw_intr_on(ncr_sc)
653 	struct ncr5380_softc *ncr_sc;
654 {
655 	u_int32_t csr;
656 
657 	sw_dma_setup(ncr_sc);
658 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
659 	csr |= SW_CSR_DMA_EN;	/* XXX - this bit is for vme only?! */
660 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
661 }
662 
663 /*
664  * This is called when the bus is idle and we are
665  * about to start playing with the SBC chip.
666  *
667  * XXX THIS MIGHT NOT WORK RIGHT!
668  */
669 void
670 sw_intr_off(ncr_sc)
671 	struct ncr5380_softc *ncr_sc;
672 {
673 	u_int32_t csr;
674 
675 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
676 	csr &= ~SW_CSR_DMA_EN;
677 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
678 }
679 
680 
681 /*
682  * This function is called during the COMMAND or MSG_IN phase
683  * that preceeds a DATA_IN or DATA_OUT phase, in case we need
684  * to setup the DMA engine before the bus enters a DATA phase.
685  *
686  * On the OBIO version we just clear the DMA count and address
687  * here (to make sure it stays idle) and do the real setup
688  * later, in dma_start.
689  */
690 void
691 sw_dma_setup(ncr_sc)
692 	struct ncr5380_softc *ncr_sc;
693 {
694 	u_int32_t csr;
695 
696 	/* No FIFO to reset on "sw". */
697 
698 	/* Set direction (assume recv here) */
699 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
700 	csr &= ~SW_CSR_SEND;
701 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
702 
703 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
704 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
705 }
706 
707 
708 void
709 sw_dma_start(ncr_sc)
710 	struct ncr5380_softc *ncr_sc;
711 {
712 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
713 	struct sci_req *sr = ncr_sc->sc_current;
714 	struct sw_dma_handle *dh = sr->sr_dma_hand;
715 	u_long dva;
716 	int xlen, adj, adjlen;
717 	u_int mode;
718 	u_int32_t csr;
719 
720 	/*
721 	 * Get the DVMA mapping for this segment.
722 	 */
723 	dva = (u_long)(dh->dh_dvma);
724 	if (dva & 1)
725 		panic("sw_dma_start: bad dva=0x%lx", dva);
726 
727 	xlen = ncr_sc->sc_datalen;
728 	xlen &= ~1;
729 	sc->sc_xlen = xlen;	/* XXX: or less... */
730 
731 #ifdef	DEBUG
732 	if (sw_debug & 2) {
733 		printf("sw_dma_start: dh=%p, dva=0x%lx, xlen=%d\n",
734 		    dh, dva, xlen);
735 	}
736 #endif
737 
738 	/*
739 	 * Set up the DMA controller.
740 	 * Note that (dh->dh_len < sc_datalen)
741 	 */
742 
743 	/* Set direction (send/recv) */
744 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
745 	if (dh->dh_flags & SIDH_OUT) {
746 		csr |= SW_CSR_SEND;
747 	} else {
748 		csr &= ~SW_CSR_SEND;
749 	}
750 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
751 
752 	/*
753 	 * The "sw" needs longword aligned transfers.  We
754 	 * detect a shortword aligned transfer here, and adjust the
755 	 * DMA transfer by 2 bytes.  These two bytes are read/written
756 	 * in PIO mode just before the DMA is started.
757 	 */
758 	adj = 0;
759 	if (dva & 2) {
760 		adj = 2;
761 #ifdef DEBUG
762 		if (sw_debug & 2)
763 			printf("sw_dma_start: adjusted up %d bytes\n", adj);
764 #endif
765 	}
766 
767 	/* We have to frob the address on the "sw". */
768 	dh->dh_startingpa = (dva | 0xF00000);
769 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, (u_int)(dh->dh_startingpa + adj));
770 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, xlen - adj);
771 
772 	/*
773 	 * Acknowledge the phase change.  (After DMA setup!)
774 	 * Put the SBIC into DMA mode, and start the transfer.
775 	 */
776 	if (dh->dh_flags & SIDH_OUT) {
777 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_OUT);
778 		if (adj) {
779 			adjlen = ncr5380_pio_out(ncr_sc, PHASE_DATA_OUT,
780 			    adj, dh->dh_addr);
781 			if (adjlen != adj)
782 				printf("%s: bad outgoing 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, SCI_ICMD_DATA);
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_dma_send, 0); 	/* start it */
791 	} else {
792 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_IN);
793 		if (adj) {
794 			adjlen = ncr5380_pio_in(ncr_sc, PHASE_DATA_IN,
795 			    adj, dh->dh_addr);
796 			if (adjlen != adj)
797 				printf("%s: bad incoming adj, %d != %d\n",
798 				    ncr_sc->sc_dev.dv_xname, adjlen, adj);
799 		}
800 		SCI_CLR_INTR(ncr_sc);
801 		NCR5380_WRITE(ncr_sc, sci_icmd, 0);
802 		mode = NCR5380_READ(ncr_sc, sci_mode);
803 		mode |= (SCI_MODE_DMA | SCI_MODE_DMA_IE);
804 		NCR5380_WRITE(ncr_sc, sci_mode, mode);
805 		NCR5380_WRITE(ncr_sc, sci_irecv, 0); 	/* start it */
806 	}
807 
808 	/* Let'er rip! */
809 	csr |= SW_CSR_DMA_EN;
810 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
811 
812 	ncr_sc->sc_state |= NCR_DOINGDMA;
813 
814 #ifdef	DEBUG
815 	if (sw_debug & 2) {
816 		printf("sw_dma_start: started, flags=0x%x\n",
817 		    ncr_sc->sc_state);
818 	}
819 #endif
820 }
821 
822 
823 void
824 sw_dma_eop(ncr_sc)
825 	struct ncr5380_softc *ncr_sc;
826 {
827 
828 	/* Not needed - DMA was stopped prior to examining sci_csr */
829 }
830 
831 #if (defined(DEBUG) || defined(DIAGNOSTIC)) && !defined(COUNT_SW_LEFTOVERS)
832 #define COUNT_SW_LEFTOVERS
833 #endif
834 #ifdef COUNT_SW_LEFTOVERS
835 /*
836  * Let's find out how often these occur.  Read these with DDB from time
837  * to time.
838  */
839 int	sw_3_leftover = 0;
840 int	sw_2_leftover = 0;
841 int	sw_1_leftover = 0;
842 int	sw_0_leftover = 0;
843 #endif
844 
845 void
846 sw_dma_stop(ncr_sc)
847 	struct ncr5380_softc *ncr_sc;
848 {
849 	struct sci_req *sr = ncr_sc->sc_current;
850 	struct sw_dma_handle *dh = sr->sr_dma_hand;
851 	int ntrans = 0, dva;
852 	u_int mode;
853 	u_int32_t csr;
854 
855 	if ((ncr_sc->sc_state & NCR_DOINGDMA) == 0) {
856 #ifdef	DEBUG
857 		printf("sw_dma_stop: dma not running\n");
858 #endif
859 		return;
860 	}
861 	ncr_sc->sc_state &= ~NCR_DOINGDMA;
862 
863 	/* First, halt the DMA engine. */
864 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
865 	csr &= ~SW_CSR_DMA_EN;
866 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
867 
868 	/*
869 	 * XXX HARDWARE BUG!
870 	 * Apparently, some early 4/100 SCSI controllers had a hardware
871 	 * bug that caused the controller to do illegal memory access.
872 	 * We see this as SW_CSR_DMA_BUS_ERR (makes sense).  To work around
873 	 * this, we simply need to clean up after ourselves ... there will
874 	 * be as many as 3 bytes left over.  Since we clean up "left-over"
875 	 * bytes on every read anyway, we just continue to chug along
876 	 * if SW_CSR_DMA_BUS_ERR is asserted.  (This was probably worked
877 	 * around in hardware later with the "left-over byte" indicator
878 	 * in the VME controller.)
879 	 */
880 #if 0
881 	if (csr & (SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR)) {
882 #else
883 	if (csr & (SW_CSR_DMA_CONFLICT)) {
884 #endif
885 		printf("sw: DMA error, csr=0x%x, reset\n", csr);
886 		sr->sr_xs->error = XS_DRIVER_STUFFUP;
887 		ncr_sc->sc_state |= NCR_ABORTING;
888 		sw_reset_adapter(ncr_sc);
889 	}
890 
891 	/* Note that timeout may have set the error flag. */
892 	if (ncr_sc->sc_state & NCR_ABORTING)
893 		goto out;
894 
895 	/*
896 	 * Now try to figure out how much actually transferred
897 	 *
898 	 * The "sw" doesn't have a FIFO or a bcr, so we've stored
899 	 * the starting PA of the transfer in the DMA handle,
900 	 * and subtract it from the ending PA left in the dma_addr
901 	 * register.
902 	 */
903 	dva = SWREG_READ(ncr_sc, SWREG_DMA_ADDR);
904 	ntrans = (dva - dh->dh_startingpa);
905 
906 #ifdef	DEBUG
907 	if (sw_debug & 2) {
908 		printf("sw_dma_stop: ntrans=0x%x\n", ntrans);
909 	}
910 #endif
911 
912 	if (ntrans > ncr_sc->sc_datalen)
913 		panic("sw_dma_stop: excess transfer");
914 
915 	/* Adjust data pointer */
916 	ncr_sc->sc_dataptr += ntrans;
917 	ncr_sc->sc_datalen -= ntrans;
918 
919 	/*
920 	 * After a read, we may need to clean-up
921 	 * "Left-over bytes"  (yuck!)  The "sw" doesn't
922 	 * have a "left-over" indicator, so we have to so
923 	 * this no matter what.  Ick.
924 	 */
925 	if ((dh->dh_flags & SIDH_OUT) == 0) {
926 		char *cp = ncr_sc->sc_dataptr;
927 		u_int32_t bpr;
928 
929 		bpr = SWREG_READ(ncr_sc, SWREG_BPR);
930 
931 		switch (dva & 3) {
932 		case 3:
933 			cp[0] = (bpr & 0xff000000) >> 24;
934 			cp[1] = (bpr & 0x00ff0000) >> 16;
935 			cp[2] = (bpr & 0x0000ff00) >> 8;
936 #ifdef COUNT_SW_LEFTOVERS
937 			++sw_3_leftover;
938 #endif
939 			break;
940 
941 		case 2:
942 			cp[0] = (bpr & 0xff000000) >> 24;
943 			cp[1] = (bpr & 0x00ff0000) >> 16;
944 #ifdef COUNT_SW_LEFTOVERS
945 			++sw_2_leftover;
946 #endif
947 			break;
948 
949 		case 1:
950 			cp[0] = (bpr & 0xff000000) >> 24;
951 #ifdef COUNT_SW_LEFTOVERS
952 			++sw_1_leftover;
953 #endif
954 			break;
955 
956 #ifdef COUNT_SW_LEFTOVERS
957 		default:
958 			++sw_0_leftover;
959 			break;
960 #endif
961 		}
962 	}
963 
964  out:
965 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
966 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
967 
968 	/* Put SBIC back in PIO mode. */
969 	mode = NCR5380_READ(ncr_sc, sci_mode);
970 	mode &= ~(SCI_MODE_DMA | SCI_MODE_DMA_IE);
971 	NCR5380_WRITE(ncr_sc, sci_mode, mode);
972 	NCR5380_WRITE(ncr_sc, sci_icmd, 0);
973 
974 #ifdef DEBUG
975 	if (sw_debug & 2) {
976 		printf("sw_dma_stop: ntrans=0x%x\n", ntrans);
977 	}
978 #endif
979 }
980