xref: /netbsd-src/sys/dev/vme/si.c (revision 06be8101a16cc95f40783b3cb7afd12112103a9a)
1 /*	$NetBSD: si.c,v 1.6 2001/11/13 06:17:07 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996,2000 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, Jason R. Thorpe and
9  * Paul Kranenburg.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *        This product includes software developed by the NetBSD
22  *        Foundation, Inc. and its contributors.
23  * 4. Neither the name of The NetBSD Foundation nor the names of its
24  *    contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37  * POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * This file contains VME bus-dependent of the `si' SCSI adapter.
42  * This hardware is frequently found on Sun 3 and Sun 4 machines.
43  *
44  * The SCSI machinery on this adapter is implemented by an NCR5380,
45  * which is taken care of by the chipset driver in /sys/dev/ic/ncr5380sbc.c
46  *
47  * The logic has a bit to enable or disable the DMA engine,
48  * but that bit also gates the interrupt line from the NCR5380!
49  * Therefore, in order to get any interrupt from the 5380, (i.e.
50  * for reselect) one must clear the DMA engine transfer count and
51  * then enable DMA.  This has the further complication that you
52  * CAN NOT touch the NCR5380 while the DMA enable bit is set, so
53  * we have to turn DMA back off before we even look at the 5380.
54  *
55  * What wonderfully whacky hardware this is!
56  *
57  */
58 
59 /*
60  * This driver originated as an MD implementation for the sun3 and sun4
61  * ports. The notes pertaining to that history are included below.
62  *
63  * David Jones wrote the initial version of this module for NetBSD/sun3,
64  * which included support for the VME adapter only. (no reselection).
65  *
66  * Gordon Ross added support for the Sun 3 OBIO adapter, and re-worked
67  * both the VME and OBIO code to support disconnect/reselect.
68  * (Required figuring out the hardware "features" noted above.)
69  *
70  * The autoconfiguration boilerplate came from Adam Glass.
71  *
72  * Jason R. Thorpe ported the autoconfiguration and VME portions to
73  * NetBSD/sparc, and added initial support for the 4/100 "SCSI Weird",
74  * a wacky OBIO variant of the VME SCSI-3.  Many thanks to Chuck Cranor
75  * for lots of helpful tips and suggestions.  Thanks also to Paul Kranenburg
76  * and Chris Torek for bits of insight needed along the way.  Thanks to
77  * David Gilbert and Andrew Gillham who risked filesystem life-and-limb
78  * for the sake of testing.  Andrew Gillham helped work out the bugs
79  * the 4/100 DMA code.
80  */
81 
82 #include <sys/cdefs.h>
83 __KERNEL_RCSID(0, "$NetBSD: si.c,v 1.6 2001/11/13 06:17:07 lukem Exp $");
84 
85 #include "opt_ddb.h"
86 
87 #include <sys/types.h>
88 #include <sys/param.h>
89 #include <sys/systm.h>
90 #include <sys/kernel.h>
91 #include <sys/malloc.h>
92 #include <sys/errno.h>
93 #include <sys/device.h>
94 #include <sys/buf.h>
95 
96 #include <machine/bus.h>
97 #include <machine/intr.h>
98 
99 #include <dev/vme/vmereg.h>
100 #include <dev/vme/vmevar.h>
101 
102 #include <dev/scsipi/scsi_all.h>
103 #include <dev/scsipi/scsipi_all.h>
104 #include <dev/scsipi/scsipi_debug.h>
105 #include <dev/scsipi/scsiconf.h>
106 
107 #ifndef DDB
108 #define	Debugger()
109 #endif
110 
111 #ifndef DEBUG
112 #define DEBUG XXX
113 #endif
114 
115 #include <dev/ic/ncr5380reg.h>
116 #include <dev/ic/ncr5380var.h>
117 
118 #include <dev/vme/sireg.h>
119 
120 /*
121  * Transfers smaller than this are done using PIO
122  * (on assumption they're not worth DMA overhead)
123  */
124 #define	MIN_DMA_LEN 128
125 
126 #ifdef	DEBUG
127 int si_debug = 0;
128 #endif
129 
130 /*
131  * This structure is used to keep track of mapped DMA requests.
132  */
133 struct si_dma_handle {
134 	int 		dh_flags;
135 #define	SIDH_BUSY	0x01		/* This DH is in use */
136 #define	SIDH_OUT	0x02		/* DMA does data out (write) */
137 	int 		dh_maplen;	/* Original data length */
138 	bus_dmamap_t	dh_dmamap;
139 #define dh_dvma	dh_dmamap->dm_segs[0].ds_addr /* VA of buffer in DVMA space */
140 };
141 
142 /*
143  * The first structure member has to be the ncr5380_softc
144  * so we can just cast to go back and fourth between them.
145  */
146 struct si_softc {
147 	struct ncr5380_softc	ncr_sc;
148 	bus_space_tag_t		sc_bustag;	/* bus tags */
149 	bus_dma_tag_t		sc_dmatag;
150 	vme_chipset_tag_t	sc_vctag;
151 
152 	int		sc_adapter_iv_am; /* int. vec + address modifier */
153 	struct si_dma_handle *sc_dma;
154 	int		sc_xlen;	/* length of current DMA segment. */
155 	int		sc_options;	/* options for this instance. */
156 };
157 
158 /*
159  * Options.  By default, DMA is enabled and DMA completion interrupts
160  * and reselect are disabled.  You may enable additional features
161  * the `flags' directive in your kernel's configuration file.
162  *
163  * Alternatively, you can patch your kernel with DDB or some other
164  * mechanism.  The sc_options member of the softc is OR'd with
165  * the value in si_options.
166  *
167  * Note, there's a separate sw_options to make life easier.
168  */
169 #define	SI_ENABLE_DMA	0x01	/* Use DMA (maybe polled) */
170 #define	SI_DMA_INTR	0x02	/* DMA completion interrupts */
171 #define	SI_DO_RESELECT	0x04	/* Allow disconnect/reselect */
172 #define	SI_OPTIONS_MASK	(SI_ENABLE_DMA|SI_DMA_INTR|SI_DO_RESELECT)
173 #define SI_OPTIONS_BITS	"\10\3RESELECT\2DMA_INTR\1DMA"
174 int si_options = SI_ENABLE_DMA|SI_DMA_INTR|SI_DO_RESELECT;
175 
176 static int	si_match __P((struct device *, struct cfdata *, void *));
177 static void	si_attach __P((struct device *, struct device *, void *));
178 static int	si_intr __P((void *));
179 static void	si_reset_adapter __P((struct ncr5380_softc *));
180 
181 void	si_dma_alloc __P((struct ncr5380_softc *));
182 void	si_dma_free __P((struct ncr5380_softc *));
183 void	si_dma_poll __P((struct ncr5380_softc *));
184 
185 void	si_dma_setup __P((struct ncr5380_softc *));
186 void	si_dma_start __P((struct ncr5380_softc *));
187 void	si_dma_eop __P((struct ncr5380_softc *));
188 void	si_dma_stop __P((struct ncr5380_softc *));
189 
190 void	si_intr_on  __P((struct ncr5380_softc *));
191 void	si_intr_off __P((struct ncr5380_softc *));
192 
193 /*
194  * Shorthand bus space access
195  * XXX - must look into endian issues here.
196  */
197 #define SIREG_READ(sc, index) \
198 	bus_space_read_2((sc)->sc_regt, (sc)->sc_regh, index)
199 #define SIREG_WRITE(sc, index, v) \
200 	bus_space_write_2((sc)->sc_regt, (sc)->sc_regh, index, v)
201 
202 
203 /* Auto-configuration glue. */
204 struct cfattach si_ca = {
205 	sizeof(struct si_softc), si_match, si_attach
206 };
207 
208 static int
209 si_match(parent, cf, aux)
210 	struct device	*parent;
211 	struct cfdata *cf;
212 	void *aux;
213 {
214 	struct vme_attach_args	*va = aux;
215 	vme_chipset_tag_t	ct = va->va_vct;
216         vme_am_t		mod;
217         vme_addr_t		vme_addr;
218 
219 	/* Make sure there is something there... */
220 	mod = VME_AM_A24 | VME_AM_MBO | VME_AM_SUPER | VME_AM_DATA;
221 	vme_addr = va->r[0].offset;
222 
223 	if (vme_probe(ct, vme_addr, 1, mod, VME_D8, NULL, 0) != 0)
224 		return (0);
225 
226 	/*
227 	 * If this is a VME SCSI board, we have to determine whether
228 	 * it is an "sc" (Sun2) or "si" (Sun3) SCSI board.  This can
229 	 * be determined using the fact that the "sc" board occupies
230 	 * 4K bytes in VME space but the "si" board occupies 2K bytes.
231 	 */
232 	return (vme_probe(ct, vme_addr + 0x801, 1, mod, VME_D8, NULL, 0) != 0);
233 }
234 
235 static void
236 si_attach(parent, self, aux)
237 	struct device	*parent, *self;
238 	void		*aux;
239 {
240 	struct si_softc		*sc = (struct si_softc *) self;
241 	struct ncr5380_softc *ncr_sc = &sc->ncr_sc;
242 	struct vme_attach_args	*va = aux;
243 	vme_chipset_tag_t	ct = va->va_vct;
244 	bus_space_tag_t		bt;
245 	bus_space_handle_t	bh;
246 	vme_mapresc_t resc;
247 	vme_intr_handle_t	ih;
248 	vme_am_t		mod;
249 	char bits[64];
250 	int i;
251 
252 	sc->sc_dmatag = va->va_bdt;
253 	sc->sc_vctag = ct;
254 
255 	mod = VME_AM_A24 | VME_AM_MBO | VME_AM_SUPER | VME_AM_DATA;
256 
257 	if (vme_space_map(ct, va->r[0].offset, SIREG_BANK_SZ,
258 			  mod, VME_D8, 0, &bt, &bh, &resc) != 0)
259 		panic("%s: vme_space_map", ncr_sc->sc_dev.dv_xname);
260 
261 	ncr_sc->sc_regt = bt;
262 	ncr_sc->sc_regh = bh;
263 
264 	sc->sc_options = si_options;
265 
266 	ncr_sc->sc_dma_setup = si_dma_setup;
267 	ncr_sc->sc_dma_start = si_dma_start;
268 	ncr_sc->sc_dma_eop   = si_dma_stop;
269 	ncr_sc->sc_dma_stop  = si_dma_stop;
270 
271 	vme_intr_map(ct, va->ilevel, va->ivector, &ih);
272 	vme_intr_establish(ct, ih, IPL_BIO, si_intr, sc);
273 
274 	printf("\n");
275 
276 	sc->sc_adapter_iv_am = (mod << 8) | (va->ivector & 0xFF);
277 
278 	/*
279 	 * Pull in the options flags.  Allow the user to completely
280 	 * override the default values.
281 	 */
282 	if ((ncr_sc->sc_dev.dv_cfdata->cf_flags & SI_OPTIONS_MASK) != 0)
283 		sc->sc_options =
284 		    (ncr_sc->sc_dev.dv_cfdata->cf_flags & SI_OPTIONS_MASK);
285 
286 	/*
287 	 * Initialize fields used by the MI code
288 	 */
289 
290 	/* NCR5380 register bank offsets */
291 	ncr_sc->sci_r0 = 0;
292 	ncr_sc->sci_r1 = 1;
293 	ncr_sc->sci_r2 = 2;
294 	ncr_sc->sci_r3 = 3;
295 	ncr_sc->sci_r4 = 4;
296 	ncr_sc->sci_r5 = 5;
297 	ncr_sc->sci_r6 = 6;
298 	ncr_sc->sci_r7 = 7;
299 
300 	ncr_sc->sc_rev = NCR_VARIANT_NCR5380;
301 
302 	/*
303 	 * MD function pointers used by the MI code.
304 	 */
305 	ncr_sc->sc_pio_out = ncr5380_pio_out;
306 	ncr_sc->sc_pio_in =  ncr5380_pio_in;
307 	ncr_sc->sc_dma_alloc = si_dma_alloc;
308 	ncr_sc->sc_dma_free  = si_dma_free;
309 	ncr_sc->sc_dma_poll  = si_dma_poll;
310 
311 	ncr_sc->sc_flags = 0;
312 	if ((sc->sc_options & SI_DO_RESELECT) == 0)
313 		ncr_sc->sc_no_disconnect = 0xFF;
314 	if ((sc->sc_options & SI_DMA_INTR) == 0)
315 		ncr_sc->sc_flags |= NCR5380_FORCE_POLLING;
316 	ncr_sc->sc_min_dma_len = MIN_DMA_LEN;
317 
318 	/*
319 	 * Allocate DMA handles.
320 	 */
321 	i = SCI_OPENINGS * sizeof(struct si_dma_handle);
322 	sc->sc_dma = (struct si_dma_handle *)malloc(i, M_DEVBUF, M_NOWAIT);
323 	if (sc->sc_dma == NULL)
324 		panic("si: dma handle malloc failed\n");
325 
326 	for (i = 0; i < SCI_OPENINGS; i++) {
327 		sc->sc_dma[i].dh_flags = 0;
328 
329 		/* Allocate a DMA handle */
330 		if (vme_dmamap_create(
331 				sc->sc_vctag,	/* VME chip tag */
332 				MAXPHYS,	/* size */
333 				VME_AM_A24,	/* address modifier */
334 				VME_D16,	/* data size */
335 				0,		/* swap */
336 				1,		/* nsegments */
337 				MAXPHYS,	/* maxsegsz */
338 				0,		/* boundary */
339 				BUS_DMA_NOWAIT,
340 				&sc->sc_dma[i].dh_dmamap) != 0) {
341 
342 			printf("%s: DMA buffer map create error\n",
343 				ncr_sc->sc_dev.dv_xname);
344 			return;
345 		}
346 	}
347 
348 	if (sc->sc_options) {
349 		printf("%s: options=%s\n", ncr_sc->sc_dev.dv_xname,
350 			bitmask_snprintf(sc->sc_options, SI_OPTIONS_BITS,
351 			    bits, sizeof(bits)));
352 	}
353 
354 	ncr_sc->sc_channel.chan_id = 7;
355 	ncr_sc->sc_adapter.adapt_minphys = minphys;
356 
357 	/*
358 	 *  Initialize si board itself.
359 	 */
360 	si_reset_adapter(ncr_sc);
361 	ncr5380_attach(ncr_sc);
362 
363 	if (sc->sc_options & SI_DO_RESELECT) {
364 		/*
365 		 * Need to enable interrupts (and DMA!)
366 		 * on this H/W for reselect to work.
367 		 */
368 		ncr_sc->sc_intr_on   = si_intr_on;
369 		ncr_sc->sc_intr_off  = si_intr_off;
370 	}
371 }
372 
373 #define CSR_WANT (SI_CSR_SBC_IP | SI_CSR_DMA_IP | \
374 	SI_CSR_DMA_CONFLICT | SI_CSR_DMA_BUS_ERR )
375 
376 static int
377 si_intr(void *arg)
378 {
379 	struct si_softc *sc = arg;
380 	struct ncr5380_softc *ncr_sc = (struct ncr5380_softc *)arg;
381 	int dma_error, claimed;
382 	u_short csr;
383 
384 	claimed = 0;
385 	dma_error = 0;
386 
387 	/* SBC interrupt? DMA interrupt? */
388 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
389 
390 	NCR_TRACE("si_intr: csr=0x%x\n", csr);
391 
392 	if (csr & SI_CSR_DMA_CONFLICT) {
393 		dma_error |= SI_CSR_DMA_CONFLICT;
394 		printf("si_intr: DMA conflict\n");
395 	}
396 	if (csr & SI_CSR_DMA_BUS_ERR) {
397 		dma_error |= SI_CSR_DMA_BUS_ERR;
398 		printf("si_intr: DMA bus error\n");
399 	}
400 	if (dma_error) {
401 		if (sc->ncr_sc.sc_state & NCR_DOINGDMA)
402 			sc->ncr_sc.sc_state |= NCR_ABORTING;
403 		/* Make sure we will call the main isr. */
404 		csr |= SI_CSR_DMA_IP;
405 	}
406 
407 	if (csr & (SI_CSR_SBC_IP | SI_CSR_DMA_IP)) {
408 		claimed = ncr5380_intr(&sc->ncr_sc);
409 #ifdef DEBUG
410 		if (!claimed) {
411 			printf("si_intr: spurious from SBC\n");
412 			if (si_debug & 4) {
413 				Debugger();	/* XXX */
414 			}
415 		}
416 #endif
417 	}
418 
419 	return (claimed);
420 }
421 
422 
423 static void
424 si_reset_adapter(struct ncr5380_softc *ncr_sc)
425 {
426 	struct si_softc *sc = (struct si_softc *)ncr_sc;
427 
428 #ifdef	DEBUG
429 	if (si_debug) {
430 		printf("si_reset_adapter\n");
431 	}
432 #endif
433 
434 	/*
435 	 * The SCSI3 controller has an 8K FIFO to buffer data between the
436 	 * 5380 and the DMA.  Make sure it starts out empty.
437 	 *
438 	 * The reset bits in the CSR are active low.
439 	 */
440 	SIREG_WRITE(ncr_sc, SIREG_CSR, 0);
441 	delay(10);
442 	SIREG_WRITE(ncr_sc, SIREG_CSR,
443 			SI_CSR_FIFO_RES | SI_CSR_SCSI_RES | SI_CSR_INTR_EN);
444 	delay(10);
445 
446 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNT, 0);
447 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRH, 0);
448 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRL, 0);
449 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, 0);
450 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTL, 0);
451 	SIREG_WRITE(ncr_sc, SIREG_IV_AM, sc->sc_adapter_iv_am);
452 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNTH, 0);
453 
454 	SCI_CLR_INTR(ncr_sc);
455 }
456 
457 /*****************************************************************
458  * Common functions for DMA
459  ****************************************************************/
460 
461 /*
462  * Allocate a DMA handle and put it in sc->sc_dma.  Prepare
463  * for DMA transfer.
464  */
465 void
466 si_dma_alloc(ncr_sc)
467 	struct ncr5380_softc *ncr_sc;
468 {
469 	struct si_softc *sc = (struct si_softc *)ncr_sc;
470 	struct sci_req *sr = ncr_sc->sc_current;
471 	struct scsipi_xfer *xs = sr->sr_xs;
472 	struct si_dma_handle *dh;
473 	int i, xlen;
474 	u_long addr;
475 
476 #ifdef DIAGNOSTIC
477 	if (sr->sr_dma_hand != NULL)
478 		panic("si_dma_alloc: already have DMA handle");
479 #endif
480 
481 #if 1	/* XXX - Temporary */
482 	/* XXX - In case we think DMA is completely broken... */
483 	if ((sc->sc_options & SI_ENABLE_DMA) == 0)
484 		return;
485 #endif
486 
487 	addr = (u_long) ncr_sc->sc_dataptr;
488 	xlen = ncr_sc->sc_datalen;
489 
490 	/* If the DMA start addr is misaligned then do PIO */
491 	if ((addr & 1) || (xlen & 1)) {
492 		printf("si_dma_alloc: misaligned.\n");
493 		return;
494 	}
495 
496 	/* Make sure our caller checked sc_min_dma_len. */
497 	if (xlen < MIN_DMA_LEN)
498 		panic("si_dma_alloc: xlen=0x%x\n", xlen);
499 
500 	/* Find free DMA handle.  Guaranteed to find one since we have
501 	   as many DMA handles as the driver has processes. */
502 	for (i = 0; i < SCI_OPENINGS; i++) {
503 		if ((sc->sc_dma[i].dh_flags & SIDH_BUSY) == 0)
504 			goto found;
505 	}
506 	panic("si: no free DMA handles.");
507 
508 found:
509 	dh = &sc->sc_dma[i];
510 	dh->dh_flags = SIDH_BUSY;
511 	dh->dh_maplen  = xlen;
512 
513 	/* Copy the "write" flag for convenience. */
514 	if ((xs->xs_control & XS_CTL_DATA_OUT) != 0)
515 		dh->dh_flags |= SIDH_OUT;
516 
517 	/*
518 	 * Double-map the buffer into DVMA space.  If we can't re-map
519 	 * the buffer, we print a warning and fall back to PIO mode.
520 	 *
521 	 * NOTE: it is not safe to sleep here!
522 	 */
523 	if (bus_dmamap_load(sc->sc_dmatag, dh->dh_dmamap,
524 			    (caddr_t)addr, xlen, NULL, BUS_DMA_NOWAIT) != 0) {
525 		/* Can't remap segment */
526 		printf("si_dma_alloc: can't remap 0x%lx/0x%x, doing PIO\n",
527 			addr, dh->dh_maplen);
528 		dh->dh_flags = 0;
529 		return;
530 	}
531 	bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap, addr, xlen,
532 			(dh->dh_flags & SIDH_OUT)
533 				? BUS_DMASYNC_PREWRITE
534 				: BUS_DMASYNC_PREREAD);
535 
536 	/* success */
537 	sr->sr_dma_hand = dh;
538 
539 	return;
540 }
541 
542 
543 void
544 si_dma_free(ncr_sc)
545 	struct ncr5380_softc *ncr_sc;
546 {
547 	struct si_softc *sc = (struct si_softc *)ncr_sc;
548 	struct sci_req *sr = ncr_sc->sc_current;
549 	struct si_dma_handle *dh = sr->sr_dma_hand;
550 
551 #ifdef DIAGNOSTIC
552 	if (dh == NULL)
553 		panic("si_dma_free: no DMA handle");
554 #endif
555 
556 	if (ncr_sc->sc_state & NCR_DOINGDMA)
557 		panic("si_dma_free: free while in progress");
558 
559 	if (dh->dh_flags & SIDH_BUSY) {
560 		/* Give back the DVMA space. */
561 		bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap,
562 				dh->dh_dvma, dh->dh_maplen,
563 				(dh->dh_flags & SIDH_OUT)
564 					? BUS_DMASYNC_POSTWRITE
565 					: BUS_DMASYNC_POSTREAD);
566 		bus_dmamap_unload(sc->sc_dmatag, dh->dh_dmamap);
567 		dh->dh_flags = 0;
568 	}
569 	sr->sr_dma_hand = NULL;
570 }
571 
572 
573 /*
574  * Poll (spin-wait) for DMA completion.
575  * Called right after xx_dma_start(), and
576  * xx_dma_stop() will be called next.
577  * Same for either VME or OBIO.
578  */
579 void
580 si_dma_poll(ncr_sc)
581 	struct ncr5380_softc *ncr_sc;
582 {
583 	struct sci_req *sr = ncr_sc->sc_current;
584 	int tmo, csr_mask, csr;
585 
586 	/* Make sure DMA started successfully. */
587 	if (ncr_sc->sc_state & NCR_ABORTING)
588 		return;
589 
590 	csr_mask = SI_CSR_SBC_IP | SI_CSR_DMA_IP |
591 		SI_CSR_DMA_CONFLICT | SI_CSR_DMA_BUS_ERR;
592 
593 	tmo = 50000;	/* X100 = 5 sec. */
594 	for (;;) {
595 		csr = SIREG_READ(ncr_sc, SIREG_CSR);
596 		if (csr & csr_mask)
597 			break;
598 		if (--tmo <= 0) {
599 			printf("%s: DMA timeout (while polling)\n",
600 			    ncr_sc->sc_dev.dv_xname);
601 			/* Indicate timeout as MI code would. */
602 			sr->sr_flags |= SR_OVERDUE;
603 			break;
604 		}
605 		delay(100);
606 	}
607 
608 #ifdef	DEBUG
609 	if (si_debug) {
610 		printf("si_dma_poll: done, csr=0x%x\n", csr);
611 	}
612 #endif
613 }
614 
615 
616 /*****************************************************************
617  * VME functions for DMA
618  ****************************************************************/
619 
620 
621 /*
622  * This is called when the bus is going idle,
623  * so we want to enable the SBC interrupts.
624  * That is controlled by the DMA enable!
625  * Who would have guessed!
626  * What a NASTY trick!
627  */
628 void
629 si_intr_on(ncr_sc)
630 	struct ncr5380_softc *ncr_sc;
631 {
632 	u_int16_t csr;
633 
634 	/* Clear DMA start address and counters */
635 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRH, 0);
636 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRL, 0);
637 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, 0);
638 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTL, 0);
639 
640 	/* Enter receive mode (for safety) and enable DMA engine */
641 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
642 	csr &= ~SI_CSR_SEND;
643 	csr |= SI_CSR_DMA_EN;
644 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
645 }
646 
647 /*
648  * This is called when the bus is idle and we are
649  * about to start playing with the SBC chip.
650  */
651 void
652 si_intr_off(ncr_sc)
653 	struct ncr5380_softc *ncr_sc;
654 {
655 	u_int16_t csr;
656 
657 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
658 	csr &= ~SI_CSR_DMA_EN;
659 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
660 }
661 
662 /*
663  * This function is called during the COMMAND or MSG_IN phase
664  * that precedes a DATA_IN or DATA_OUT phase, in case we need
665  * to setup the DMA engine before the bus enters a DATA phase.
666  *
667  * XXX: The VME adapter appears to suppress SBC interrupts
668  * when the FIFO is not empty or the FIFO count is non-zero!
669  *
670  * On the VME version we just clear the DMA count and address
671  * here (to make sure it stays idle) and do the real setup
672  * later, in dma_start.
673  */
674 void
675 si_dma_setup(ncr_sc)
676 	struct ncr5380_softc *ncr_sc;
677 {
678 	struct si_softc *sc = (struct si_softc *)ncr_sc;
679 	struct sci_req *sr = ncr_sc->sc_current;
680 	struct si_dma_handle *dh = sr->sr_dma_hand;
681 	u_int16_t csr;
682 	u_long dva;
683 	int xlen;
684 
685 	/*
686 	 * Set up the DMA controller.
687 	 * Note that (dh->dh_len < sc_datalen)
688 	 */
689 
690 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
691 
692 	/* Disable DMA while we're setting up the transfer */
693 	csr &= ~SI_CSR_DMA_EN;
694 
695 	/* Reset the FIFO */
696 	csr &= ~SI_CSR_FIFO_RES;		/* active low */
697 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
698 	csr |= SI_CSR_FIFO_RES;
699 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
700 
701 	/*
702 	 * Get the DVMA mapping for this segment.
703 	 */
704 	dva = (u_long)(dh->dh_dvma);
705 	if (dva & 1)
706 		panic("si_dma_setup: bad dmaaddr=0x%lx", dva);
707 	xlen = ncr_sc->sc_datalen;
708 	xlen &= ~1;
709 	sc->sc_xlen = xlen;	/* XXX: or less... */
710 
711 #ifdef	DEBUG
712 	if (si_debug & 2) {
713 		printf("si_dma_start: dh=%p, dmaaddr=0x%lx, xlen=%d\n",
714 			   dh, dva, xlen);
715 	}
716 #endif
717 	/* Set direction (send/recv) */
718 	if (dh->dh_flags & SIDH_OUT) {
719 		csr |= SI_CSR_SEND;
720 	} else {
721 		csr &= ~SI_CSR_SEND;
722 	}
723 
724 	/* Set byte-packing control */
725 	if (dva & 2) {
726 		csr |= SI_CSR_BPCON;
727 	} else {
728 		csr &= ~SI_CSR_BPCON;
729 	}
730 
731 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
732 
733 	/* Load start address */
734 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRH, (u_int16_t)(dva >> 16));
735 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRL, (u_int16_t)(dva & 0xFFFF));
736 
737 	/* Clear DMA counters; these will be set in si_dma_start() */
738 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, 0);
739 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTL, 0);
740 
741 	/* Clear FIFO counter. (also hits dma_count) */
742 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNTH, 0);
743 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNT, 0);
744 }
745 
746 
747 void
748 si_dma_start(ncr_sc)
749 	struct ncr5380_softc *ncr_sc;
750 {
751 	struct si_softc *sc = (struct si_softc *)ncr_sc;
752 	struct sci_req *sr = ncr_sc->sc_current;
753 	struct si_dma_handle *dh = sr->sr_dma_hand;
754 	int xlen;
755 	u_int mode;
756 	u_int16_t csr;
757 
758 	xlen = sc->sc_xlen;
759 
760 	/* Load transfer length */
761 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, (u_int16_t)(xlen >> 16));
762 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTL, (u_int16_t)(xlen & 0xFFFF));
763 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNTH, (u_int16_t)(xlen >> 16));
764 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNT, (u_int16_t)(xlen & 0xFFFF));
765 
766 	/*
767 	 * Acknowledge the phase change.  (After DMA setup!)
768 	 * Put the SBIC into DMA mode, and start the transfer.
769 	 */
770 	if (dh->dh_flags & SIDH_OUT) {
771 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_OUT);
772 		SCI_CLR_INTR(ncr_sc);
773 		NCR5380_WRITE(ncr_sc, sci_icmd, SCI_ICMD_DATA);
774 
775 		mode = NCR5380_READ(ncr_sc, sci_mode);
776 		mode |= (SCI_MODE_DMA | SCI_MODE_DMA_IE);
777 		NCR5380_WRITE(ncr_sc, sci_mode, mode);
778 
779 		NCR5380_WRITE(ncr_sc, sci_dma_send, 0); /* start it */
780 	} else {
781 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_IN);
782 		SCI_CLR_INTR(ncr_sc);
783 		NCR5380_WRITE(ncr_sc, sci_icmd, 0);
784 
785 		mode = NCR5380_READ(ncr_sc, sci_mode);
786 		mode |= (SCI_MODE_DMA | SCI_MODE_DMA_IE);
787 		NCR5380_WRITE(ncr_sc, sci_mode, mode);
788 
789 		NCR5380_WRITE(ncr_sc, sci_irecv, 0); /* start it */
790 	}
791 
792 	ncr_sc->sc_state |= NCR_DOINGDMA;
793 
794 	/* Enable DMA engine */
795 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
796 	csr |= SI_CSR_DMA_EN;
797 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
798 
799 #ifdef	DEBUG
800 	if (si_debug & 2) {
801 		printf("si_dma_start: started, flags=0x%x\n",
802 			   ncr_sc->sc_state);
803 	}
804 #endif
805 }
806 
807 
808 void
809 si_dma_eop(ncr_sc)
810 	struct ncr5380_softc *ncr_sc;
811 {
812 
813 	/* Not needed - DMA was stopped prior to examining sci_csr */
814 }
815 
816 
817 void
818 si_dma_stop(ncr_sc)
819 	struct ncr5380_softc *ncr_sc;
820 {
821 	struct si_softc *sc = (struct si_softc *)ncr_sc;
822 	struct sci_req *sr = ncr_sc->sc_current;
823 	struct si_dma_handle *dh = sr->sr_dma_hand;
824 	int resid, ntrans;
825 	u_int16_t csr;
826 	u_int mode;
827 
828 	if ((ncr_sc->sc_state & NCR_DOINGDMA) == 0) {
829 #ifdef	DEBUG
830 		printf("si_dma_stop: dma not running\n");
831 #endif
832 		return;
833 	}
834 
835 	ncr_sc->sc_state &= ~NCR_DOINGDMA;
836 
837 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
838 
839 	/* First, halt the DMA engine. */
840 	csr &= ~SI_CSR_DMA_EN;
841 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
842 
843 	if (csr & (SI_CSR_DMA_CONFLICT | SI_CSR_DMA_BUS_ERR)) {
844 		printf("si: DMA error, csr=0x%x, reset\n", csr);
845 		sr->sr_xs->error = XS_DRIVER_STUFFUP;
846 		ncr_sc->sc_state |= NCR_ABORTING;
847 		si_reset_adapter(ncr_sc);
848 	}
849 
850 	/* Note that timeout may have set the error flag. */
851 	if (ncr_sc->sc_state & NCR_ABORTING)
852 		goto out;
853 
854 	/*
855 	 * Now try to figure out how much actually transferred
856 	 *
857 	 * The fifo_count does not reflect how many bytes were
858 	 * actually transferred for VME.
859 	 *
860 	 * SCSI-3 VME interface is a little funny on writes:
861 	 * if we have a disconnect, the dma has overshot by
862 	 * one byte and the resid needs to be incremented.
863 	 * Only happens for partial transfers.
864 	 * (Thanks to Matt Jacob)
865 	 */
866 
867 	resid = SIREG_READ(ncr_sc, SIREG_FIFO_CNTH) << 16;
868 	resid |= SIREG_READ(ncr_sc, SIREG_FIFO_CNT) & 0xFFFF;
869 	if (dh->dh_flags & SIDH_OUT)
870 		if ((resid > 0) && (resid < sc->sc_xlen))
871 			resid++;
872 	ntrans = sc->sc_xlen - resid;
873 
874 #ifdef	DEBUG
875 	if (si_debug & 2) {
876 		printf("si_dma_stop: resid=0x%x ntrans=0x%x\n",
877 		    resid, ntrans);
878 	}
879 #endif
880 
881 	if (ntrans > ncr_sc->sc_datalen)
882 		panic("si_dma_stop: excess transfer");
883 
884 	/* Adjust data pointer */
885 	ncr_sc->sc_dataptr += ntrans;
886 	ncr_sc->sc_datalen -= ntrans;
887 
888 #ifdef	DEBUG
889 	if (si_debug & 2) {
890 		printf("si_dma_stop: ntrans=0x%x\n", ntrans);
891 	}
892 #endif
893 
894 	/*
895 	 * After a read, we may need to clean-up
896 	 * "Left-over bytes" (yuck!)
897 	 */
898 	if (((dh->dh_flags & SIDH_OUT) == 0) &&
899 		((csr & SI_CSR_LOB) != 0))
900 	{
901 		char *cp = ncr_sc->sc_dataptr;
902 		u_int16_t bprh, bprl;
903 
904 		bprh = SIREG_READ(ncr_sc, SIREG_BPRH);
905 		bprl = SIREG_READ(ncr_sc, SIREG_BPRL);
906 
907 #ifdef DEBUG
908 		printf("si: got left-over bytes: bprh=%x, bprl=%x, csr=%x\n",
909 			bprh, bprl, csr);
910 #endif
911 
912 		if (csr & SI_CSR_BPCON) {
913 			/* have SI_CSR_BPCON */
914 			cp[-1] = (bprl & 0xff00) >> 8;
915 		} else {
916 			switch (csr & SI_CSR_LOB) {
917 			case SI_CSR_LOB_THREE:
918 				cp[-3] = (bprh & 0xff00) >> 8;
919 				cp[-2] = (bprh & 0x00ff);
920 				cp[-1] = (bprl & 0xff00) >> 8;
921 				break;
922 			case SI_CSR_LOB_TWO:
923 				cp[-2] = (bprh & 0xff00) >> 8;
924 				cp[-1] = (bprh & 0x00ff);
925 				break;
926 			case SI_CSR_LOB_ONE:
927 				cp[-1] = (bprh & 0xff00) >> 8;
928 				break;
929 			}
930 		}
931 	}
932 
933 out:
934 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRH, 0);
935 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRL, 0);
936 
937 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, 0);
938 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTL, 0);
939 
940 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNTH, 0);
941 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNT, 0);
942 
943 	mode = NCR5380_READ(ncr_sc, sci_mode);
944 	/* Put SBIC back in PIO mode. */
945 	mode &= ~(SCI_MODE_DMA | SCI_MODE_DMA_IE);
946 	NCR5380_WRITE(ncr_sc, sci_mode, mode);
947 	NCR5380_WRITE(ncr_sc, sci_icmd, 0);
948 }
949