xref: /netbsd-src/sys/dev/vme/si.c (revision 481fca6e59249d8ffcf24fef7cfbe7b131bfb080)
1 /*	$NetBSD: si.c,v 1.2 2000/07/04 01:29:14 thorpej 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 "opt_ddb.h"
83 
84 #include <sys/types.h>
85 #include <sys/param.h>
86 #include <sys/systm.h>
87 #include <sys/kernel.h>
88 #include <sys/malloc.h>
89 #include <sys/errno.h>
90 #include <sys/device.h>
91 #include <sys/buf.h>
92 
93 #include <machine/bus.h>
94 #include <machine/intr.h>
95 
96 #include <dev/vme/vmereg.h>
97 #include <dev/vme/vmevar.h>
98 
99 #include <dev/scsipi/scsi_all.h>
100 #include <dev/scsipi/scsipi_all.h>
101 #include <dev/scsipi/scsipi_debug.h>
102 #include <dev/scsipi/scsiconf.h>
103 
104 #ifndef DDB
105 #define	Debugger()
106 #endif
107 
108 #ifndef DEBUG
109 #define DEBUG XXX
110 #endif
111 
112 #include <dev/ic/ncr5380reg.h>
113 #include <dev/ic/ncr5380var.h>
114 
115 #include <dev/vme/sireg.h>
116 
117 /*
118  * Transfers smaller than this are done using PIO
119  * (on assumption they're not worth DMA overhead)
120  */
121 #define	MIN_DMA_LEN 128
122 
123 #ifdef	DEBUG
124 int si_debug = 0;
125 static int si_link_flags = 0 /* | SDEV_DB2 */ ;
126 #endif
127 
128 /*
129  * This structure is used to keep track of mapped DMA requests.
130  */
131 struct si_dma_handle {
132 	int 		dh_flags;
133 #define	SIDH_BUSY	0x01		/* This DH is in use */
134 #define	SIDH_OUT	0x02		/* DMA does data out (write) */
135 	int 		dh_maplen;	/* Original data length */
136 	bus_dmamap_t	dh_dmamap;
137 #define dh_dvma	dh_dmamap->dm_segs[0].ds_addr /* VA of buffer in DVMA space */
138 };
139 
140 /*
141  * The first structure member has to be the ncr5380_softc
142  * so we can just cast to go back and fourth between them.
143  */
144 struct si_softc {
145 	struct ncr5380_softc	ncr_sc;
146 	bus_space_tag_t		sc_bustag;	/* bus tags */
147 	bus_dma_tag_t		sc_dmatag;
148 	vme_chipset_tag_t	sc_vctag;
149 
150 	int		sc_adapter_iv_am; /* int. vec + address modifier */
151 	struct si_dma_handle *sc_dma;
152 	int		sc_xlen;	/* length of current DMA segment. */
153 	int		sc_options;	/* options for this instance. */
154 };
155 
156 /*
157  * Options.  By default, DMA is enabled and DMA completion interrupts
158  * and reselect are disabled.  You may enable additional features
159  * the `flags' directive in your kernel's configuration file.
160  *
161  * Alternatively, you can patch your kernel with DDB or some other
162  * mechanism.  The sc_options member of the softc is OR'd with
163  * the value in si_options.
164  *
165  * Note, there's a separate sw_options to make life easier.
166  */
167 #define	SI_ENABLE_DMA	0x01	/* Use DMA (maybe polled) */
168 #define	SI_DMA_INTR	0x02	/* DMA completion interrupts */
169 #define	SI_DO_RESELECT	0x04	/* Allow disconnect/reselect */
170 #define	SI_OPTIONS_MASK	(SI_ENABLE_DMA|SI_DMA_INTR|SI_DO_RESELECT)
171 #define SI_OPTIONS_BITS	"\10\3RESELECT\2DMA_INTR\1DMA"
172 int si_options = SI_ENABLE_DMA|SI_DMA_INTR|SI_DO_RESELECT;
173 
174 static int	si_match __P((struct device *, struct cfdata *, void *));
175 static void	si_attach __P((struct device *, struct device *, void *));
176 static int	si_intr __P((void *));
177 static void	si_reset_adapter __P((struct ncr5380_softc *));
178 
179 void	si_dma_alloc __P((struct ncr5380_softc *));
180 void	si_dma_free __P((struct ncr5380_softc *));
181 void	si_dma_poll __P((struct ncr5380_softc *));
182 
183 void	si_dma_setup __P((struct ncr5380_softc *));
184 void	si_dma_start __P((struct ncr5380_softc *));
185 void	si_dma_eop __P((struct ncr5380_softc *));
186 void	si_dma_stop __P((struct ncr5380_softc *));
187 
188 void	si_intr_on  __P((struct ncr5380_softc *));
189 void	si_intr_off __P((struct ncr5380_softc *));
190 
191 /*
192  * Shorthand bus space access
193  * XXX - must look into endian issues here.
194  */
195 #define SIREG_READ(sc, index) \
196 	bus_space_read_2((sc)->sc_regt, (sc)->sc_regh, index)
197 #define SIREG_WRITE(sc, index, v) \
198 	bus_space_write_2((sc)->sc_regt, (sc)->sc_regh, index, v)
199 
200 
201 /* Auto-configuration glue. */
202 struct cfattach si_ca = {
203 	sizeof(struct si_softc), si_match, si_attach
204 };
205 
206 static int
207 si_match(parent, cf, aux)
208 	struct device	*parent;
209 	struct cfdata *cf;
210 	void *aux;
211 {
212 	struct vme_attach_args	*va = aux;
213 	vme_chipset_tag_t	ct = va->va_vct;
214         vme_am_t		mod;
215         vme_addr_t		vme_addr;
216 
217 	/* Make sure there is something there... */
218 	mod = VME_AM_A24 | VME_AM_MBO | VME_AM_SUPER | VME_AM_DATA;
219 	vme_addr = va->r[0].offset;
220 
221 	if (vme_probe(ct, vme_addr, 1, mod, VME_D8, NULL, 0) != 0)
222 		return (0);
223 
224 	/*
225 	 * If this is a VME SCSI board, we have to determine whether
226 	 * it is an "sc" (Sun2) or "si" (Sun3) SCSI board.  This can
227 	 * be determined using the fact that the "sc" board occupies
228 	 * 4K bytes in VME space but the "si" board occupies 2K bytes.
229 	 */
230 	return (vme_probe(ct, vme_addr + 0x801, 1, mod, VME_D8, NULL, 0) != 0);
231 }
232 
233 static void
234 si_attach(parent, self, aux)
235 	struct device	*parent, *self;
236 	void		*aux;
237 {
238 	struct si_softc		*sc = (struct si_softc *) self;
239 	struct ncr5380_softc *ncr_sc = &sc->ncr_sc;
240 	struct vme_attach_args	*va = aux;
241 	vme_chipset_tag_t	ct = va->va_vct;
242 	bus_space_tag_t		bt;
243 	bus_space_handle_t	bh;
244 	vme_mapresc_t resc;
245 	vme_intr_handle_t	ih;
246 	vme_am_t		mod;
247 	char bits[64];
248 	int i;
249 
250 	sc->sc_dmatag = va->va_bdt;
251 	sc->sc_vctag = ct;
252 
253 	mod = VME_AM_A24 | VME_AM_MBO | VME_AM_SUPER | VME_AM_DATA;
254 
255 	if (vme_space_map(ct, va->r[0].offset, SIREG_BANK_SZ,
256 			  mod, VME_D8, 0, &bt, &bh, &resc) != 0)
257 		panic("%s: vme_space_map", ncr_sc->sc_dev.dv_xname);
258 
259 	ncr_sc->sc_regt = bt;
260 	ncr_sc->sc_regh = bh;
261 
262 	sc->sc_options = si_options;
263 
264 	ncr_sc->sc_dma_setup = si_dma_setup;
265 	ncr_sc->sc_dma_start = si_dma_start;
266 	ncr_sc->sc_dma_eop   = si_dma_stop;
267 	ncr_sc->sc_dma_stop  = si_dma_stop;
268 
269 	vme_intr_map(ct, va->ilevel, va->ivector, &ih);
270 	vme_intr_establish(ct, ih, IPL_BIO, si_intr, sc);
271 
272 	printf("\n");
273 
274 	sc->sc_adapter_iv_am = (mod << 8) | (va->ivector & 0xFF);
275 
276 	/*
277 	 * Pull in the options flags.  Allow the user to completely
278 	 * override the default values.
279 	 */
280 	if ((ncr_sc->sc_dev.dv_cfdata->cf_flags & SI_OPTIONS_MASK) != 0)
281 		sc->sc_options =
282 		    (ncr_sc->sc_dev.dv_cfdata->cf_flags & SI_OPTIONS_MASK);
283 
284 	/*
285 	 * Initialize fields used by the MI code
286 	 */
287 
288 	/* NCR5380 register bank offsets */
289 	ncr_sc->sci_r0 = 0;
290 	ncr_sc->sci_r1 = 1;
291 	ncr_sc->sci_r2 = 2;
292 	ncr_sc->sci_r3 = 3;
293 	ncr_sc->sci_r4 = 4;
294 	ncr_sc->sci_r5 = 5;
295 	ncr_sc->sci_r6 = 6;
296 	ncr_sc->sci_r7 = 7;
297 
298 	ncr_sc->sc_rev = NCR_VARIANT_NCR5380;
299 
300 	/*
301 	 * MD function pointers used by the MI code.
302 	 */
303 	ncr_sc->sc_pio_out = ncr5380_pio_out;
304 	ncr_sc->sc_pio_in =  ncr5380_pio_in;
305 	ncr_sc->sc_dma_alloc = si_dma_alloc;
306 	ncr_sc->sc_dma_free  = si_dma_free;
307 	ncr_sc->sc_dma_poll  = si_dma_poll;
308 
309 	ncr_sc->sc_flags = 0;
310 	if ((sc->sc_options & SI_DO_RESELECT) == 0)
311 		ncr_sc->sc_no_disconnect = 0xFF;
312 	if ((sc->sc_options & SI_DMA_INTR) == 0)
313 		ncr_sc->sc_flags |= NCR5380_FORCE_POLLING;
314 	ncr_sc->sc_min_dma_len = MIN_DMA_LEN;
315 
316 	/*
317 	 * Allocate DMA handles.
318 	 */
319 	i = SCI_OPENINGS * sizeof(struct si_dma_handle);
320 	sc->sc_dma = (struct si_dma_handle *)malloc(i, M_DEVBUF, M_NOWAIT);
321 	if (sc->sc_dma == NULL)
322 		panic("si: dma handle malloc failed\n");
323 
324 	for (i = 0; i < SCI_OPENINGS; i++) {
325 		sc->sc_dma[i].dh_flags = 0;
326 
327 		/* Allocate a DMA handle */
328 		if (vme_dmamap_create(
329 				sc->sc_vctag,	/* VME chip tag */
330 				MAXPHYS,	/* size */
331 				VME_AM_A24,	/* address modifier */
332 				VME_D16,	/* data size */
333 				0,		/* swap */
334 				1,		/* nsegments */
335 				MAXPHYS,	/* maxsegsz */
336 				0,		/* boundary */
337 				BUS_DMA_NOWAIT,
338 				&sc->sc_dma[i].dh_dmamap) != 0) {
339 
340 			printf("%s: DMA buffer map create error\n",
341 				ncr_sc->sc_dev.dv_xname);
342 			return;
343 		}
344 	}
345 
346 	if (sc->sc_options) {
347 		printf("%s: options=%s\n", ncr_sc->sc_dev.dv_xname,
348 			bitmask_snprintf(sc->sc_options, SI_OPTIONS_BITS,
349 			    bits, sizeof(bits)));
350 	}
351 #ifdef	DEBUG
352 	ncr_sc->sc_link.flags |= si_link_flags;
353 #endif
354 
355 	ncr_sc->sc_link.scsipi_scsi.adapter_target = 7;
356 	ncr_sc->sc_adapter.scsipi_minphys = minphys;
357 
358 	/*
359 	 *  Initialize si board itself.
360 	 */
361 	si_reset_adapter(ncr_sc);
362 	ncr5380_attach(ncr_sc);
363 
364 	if (sc->sc_options & SI_DO_RESELECT) {
365 		/*
366 		 * Need to enable interrupts (and DMA!)
367 		 * on this H/W for reselect to work.
368 		 */
369 		ncr_sc->sc_intr_on   = si_intr_on;
370 		ncr_sc->sc_intr_off  = si_intr_off;
371 	}
372 }
373 
374 #define CSR_WANT (SI_CSR_SBC_IP | SI_CSR_DMA_IP | \
375 	SI_CSR_DMA_CONFLICT | SI_CSR_DMA_BUS_ERR )
376 
377 static int
378 si_intr(void *arg)
379 {
380 	struct si_softc *sc = arg;
381 	struct ncr5380_softc *ncr_sc = (struct ncr5380_softc *)arg;
382 	int dma_error, claimed;
383 	u_short csr;
384 
385 	claimed = 0;
386 	dma_error = 0;
387 
388 	/* SBC interrupt? DMA interrupt? */
389 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
390 
391 	NCR_TRACE("si_intr: csr=0x%x\n", csr);
392 
393 	if (csr & SI_CSR_DMA_CONFLICT) {
394 		dma_error |= SI_CSR_DMA_CONFLICT;
395 		printf("si_intr: DMA conflict\n");
396 	}
397 	if (csr & SI_CSR_DMA_BUS_ERR) {
398 		dma_error |= SI_CSR_DMA_BUS_ERR;
399 		printf("si_intr: DMA bus error\n");
400 	}
401 	if (dma_error) {
402 		if (sc->ncr_sc.sc_state & NCR_DOINGDMA)
403 			sc->ncr_sc.sc_state |= NCR_ABORTING;
404 		/* Make sure we will call the main isr. */
405 		csr |= SI_CSR_DMA_IP;
406 	}
407 
408 	if (csr & (SI_CSR_SBC_IP | SI_CSR_DMA_IP)) {
409 		claimed = ncr5380_intr(&sc->ncr_sc);
410 #ifdef DEBUG
411 		if (!claimed) {
412 			printf("si_intr: spurious from SBC\n");
413 			if (si_debug & 4) {
414 				Debugger();	/* XXX */
415 			}
416 		}
417 #endif
418 	}
419 
420 	return (claimed);
421 }
422 
423 
424 static void
425 si_reset_adapter(struct ncr5380_softc *ncr_sc)
426 {
427 	struct si_softc *sc = (struct si_softc *)ncr_sc;
428 
429 #ifdef	DEBUG
430 	if (si_debug) {
431 		printf("si_reset_adapter\n");
432 	}
433 #endif
434 
435 	/*
436 	 * The SCSI3 controller has an 8K FIFO to buffer data between the
437 	 * 5380 and the DMA.  Make sure it starts out empty.
438 	 *
439 	 * The reset bits in the CSR are active low.
440 	 */
441 	SIREG_WRITE(ncr_sc, SIREG_CSR, 0);
442 	delay(10);
443 	SIREG_WRITE(ncr_sc, SIREG_CSR,
444 			SI_CSR_FIFO_RES | SI_CSR_SCSI_RES | SI_CSR_INTR_EN);
445 	delay(10);
446 
447 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNT, 0);
448 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRH, 0);
449 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRL, 0);
450 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, 0);
451 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTL, 0);
452 	SIREG_WRITE(ncr_sc, SIREG_IV_AM, sc->sc_adapter_iv_am);
453 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNTH, 0);
454 
455 	SCI_CLR_INTR(ncr_sc);
456 }
457 
458 /*****************************************************************
459  * Common functions for DMA
460  ****************************************************************/
461 
462 /*
463  * Allocate a DMA handle and put it in sc->sc_dma.  Prepare
464  * for DMA transfer.
465  */
466 void
467 si_dma_alloc(ncr_sc)
468 	struct ncr5380_softc *ncr_sc;
469 {
470 	struct si_softc *sc = (struct si_softc *)ncr_sc;
471 	struct sci_req *sr = ncr_sc->sc_current;
472 	struct scsipi_xfer *xs = sr->sr_xs;
473 	struct si_dma_handle *dh;
474 	int i, xlen;
475 	u_long addr;
476 
477 #ifdef DIAGNOSTIC
478 	if (sr->sr_dma_hand != NULL)
479 		panic("si_dma_alloc: already have DMA handle");
480 #endif
481 
482 #if 1	/* XXX - Temporary */
483 	/* XXX - In case we think DMA is completely broken... */
484 	if ((sc->sc_options & SI_ENABLE_DMA) == 0)
485 		return;
486 #endif
487 
488 	addr = (u_long) ncr_sc->sc_dataptr;
489 	xlen = ncr_sc->sc_datalen;
490 
491 	/* If the DMA start addr is misaligned then do PIO */
492 	if ((addr & 1) || (xlen & 1)) {
493 		printf("si_dma_alloc: misaligned.\n");
494 		return;
495 	}
496 
497 	/* Make sure our caller checked sc_min_dma_len. */
498 	if (xlen < MIN_DMA_LEN)
499 		panic("si_dma_alloc: xlen=0x%x\n", xlen);
500 
501 	/* Find free DMA handle.  Guaranteed to find one since we have
502 	   as many DMA handles as the driver has processes. */
503 	for (i = 0; i < SCI_OPENINGS; i++) {
504 		if ((sc->sc_dma[i].dh_flags & SIDH_BUSY) == 0)
505 			goto found;
506 	}
507 	panic("si: no free DMA handles.");
508 
509 found:
510 	dh = &sc->sc_dma[i];
511 	dh->dh_flags = SIDH_BUSY;
512 	dh->dh_maplen  = xlen;
513 
514 	/* Copy the "write" flag for convenience. */
515 	if ((xs->xs_control & XS_CTL_DATA_OUT) != 0)
516 		dh->dh_flags |= SIDH_OUT;
517 
518 	/*
519 	 * Double-map the buffer into DVMA space.  If we can't re-map
520 	 * the buffer, we print a warning and fall back to PIO mode.
521 	 *
522 	 * NOTE: it is not safe to sleep here!
523 	 */
524 	if (bus_dmamap_load(sc->sc_dmatag, dh->dh_dmamap,
525 			    (caddr_t)addr, xlen, NULL, BUS_DMA_NOWAIT) != 0) {
526 		/* Can't remap segment */
527 		printf("si_dma_alloc: can't remap 0x%lx/0x%x, doing PIO\n",
528 			addr, dh->dh_maplen);
529 		dh->dh_flags = 0;
530 		return;
531 	}
532 	bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap, addr, xlen,
533 			(dh->dh_flags & SIDH_OUT)
534 				? BUS_DMASYNC_PREWRITE
535 				: BUS_DMASYNC_PREREAD);
536 
537 	/* success */
538 	sr->sr_dma_hand = dh;
539 
540 	return;
541 }
542 
543 
544 void
545 si_dma_free(ncr_sc)
546 	struct ncr5380_softc *ncr_sc;
547 {
548 	struct si_softc *sc = (struct si_softc *)ncr_sc;
549 	struct sci_req *sr = ncr_sc->sc_current;
550 	struct si_dma_handle *dh = sr->sr_dma_hand;
551 
552 #ifdef DIAGNOSTIC
553 	if (dh == NULL)
554 		panic("si_dma_free: no DMA handle");
555 #endif
556 
557 	if (ncr_sc->sc_state & NCR_DOINGDMA)
558 		panic("si_dma_free: free while in progress");
559 
560 	if (dh->dh_flags & SIDH_BUSY) {
561 		/* Give back the DVMA space. */
562 		bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap,
563 				dh->dh_dvma, dh->dh_maplen,
564 				(dh->dh_flags & SIDH_OUT)
565 					? BUS_DMASYNC_POSTWRITE
566 					: BUS_DMASYNC_POSTREAD);
567 		bus_dmamap_unload(sc->sc_dmatag, dh->dh_dmamap);
568 		dh->dh_flags = 0;
569 	}
570 	sr->sr_dma_hand = NULL;
571 }
572 
573 
574 /*
575  * Poll (spin-wait) for DMA completion.
576  * Called right after xx_dma_start(), and
577  * xx_dma_stop() will be called next.
578  * Same for either VME or OBIO.
579  */
580 void
581 si_dma_poll(ncr_sc)
582 	struct ncr5380_softc *ncr_sc;
583 {
584 	struct sci_req *sr = ncr_sc->sc_current;
585 	int tmo, csr_mask, csr;
586 
587 	/* Make sure DMA started successfully. */
588 	if (ncr_sc->sc_state & NCR_ABORTING)
589 		return;
590 
591 	csr_mask = SI_CSR_SBC_IP | SI_CSR_DMA_IP |
592 		SI_CSR_DMA_CONFLICT | SI_CSR_DMA_BUS_ERR;
593 
594 	tmo = 50000;	/* X100 = 5 sec. */
595 	for (;;) {
596 		csr = SIREG_READ(ncr_sc, SIREG_CSR);
597 		if (csr & csr_mask)
598 			break;
599 		if (--tmo <= 0) {
600 			printf("%s: DMA timeout (while polling)\n",
601 			    ncr_sc->sc_dev.dv_xname);
602 			/* Indicate timeout as MI code would. */
603 			sr->sr_flags |= SR_OVERDUE;
604 			break;
605 		}
606 		delay(100);
607 	}
608 
609 #ifdef	DEBUG
610 	if (si_debug) {
611 		printf("si_dma_poll: done, csr=0x%x\n", csr);
612 	}
613 #endif
614 }
615 
616 
617 /*****************************************************************
618  * VME functions for DMA
619  ****************************************************************/
620 
621 
622 /*
623  * This is called when the bus is going idle,
624  * so we want to enable the SBC interrupts.
625  * That is controlled by the DMA enable!
626  * Who would have guessed!
627  * What a NASTY trick!
628  */
629 void
630 si_intr_on(ncr_sc)
631 	struct ncr5380_softc *ncr_sc;
632 {
633 	u_int16_t csr;
634 
635 	si_dma_setup(ncr_sc);
636 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
637 	csr |= SI_CSR_DMA_EN;
638 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
639 }
640 
641 /*
642  * This is called when the bus is idle and we are
643  * about to start playing with the SBC chip.
644  */
645 void
646 si_intr_off(ncr_sc)
647 	struct ncr5380_softc *ncr_sc;
648 {
649 	u_int16_t csr;
650 
651 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
652 	csr &= ~SI_CSR_DMA_EN;
653 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
654 }
655 
656 /*
657  * This function is called during the COMMAND or MSG_IN phase
658  * that preceeds a DATA_IN or DATA_OUT phase, in case we need
659  * to setup the DMA engine before the bus enters a DATA phase.
660  *
661  * XXX: The VME adapter appears to suppress SBC interrupts
662  * when the FIFO is not empty or the FIFO count is non-zero!
663  *
664  * On the VME version we just clear the DMA count and address
665  * here (to make sure it stays idle) and do the real setup
666  * later, in dma_start.
667  */
668 void
669 si_dma_setup(ncr_sc)
670 	struct ncr5380_softc *ncr_sc;
671 {
672 	u_int16_t csr;
673 
674 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
675 
676 	/* Reset the FIFO */
677 	csr &= ~SI_CSR_FIFO_RES;		/* active low */
678 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
679 	csr |= SI_CSR_FIFO_RES;
680 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
681 
682 	/* Set direction (assume recv here) */
683 	csr &= ~SI_CSR_SEND;
684 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
685 	/* Assume worst alignment */
686 	csr |= SI_CSR_BPCON;
687 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
688 
689 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRH, 0);
690 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRL, 0);
691 
692 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, 0);
693 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTL, 0);
694 
695 	/* Clear FIFO counter. (also hits dma_count) */
696 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNTH, 0);
697 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNT, 0);
698 }
699 
700 
701 void
702 si_dma_start(ncr_sc)
703 	struct ncr5380_softc *ncr_sc;
704 {
705 	struct si_softc *sc = (struct si_softc *)ncr_sc;
706 	struct sci_req *sr = ncr_sc->sc_current;
707 	struct si_dma_handle *dh = sr->sr_dma_hand;
708 	u_long dva;
709 	int xlen;
710 	u_int mode;
711 	u_int16_t csr;
712 
713 	/*
714 	 * Get the DVMA mapping for this segment.
715 	 */
716 	dva = (u_long)(dh->dh_dvma);
717 	if (dva & 1)
718 		panic("si_dma_start: bad dmaaddr=0x%lx", dva);
719 	xlen = ncr_sc->sc_datalen;
720 	xlen &= ~1;
721 	sc->sc_xlen = xlen;	/* XXX: or less... */
722 
723 #ifdef	DEBUG
724 	if (si_debug & 2) {
725 		printf("si_dma_start: dh=%p, dmaaddr=0x%lx, xlen=%d\n",
726 			   dh, dva, xlen);
727 	}
728 #endif
729 
730 	/*
731 	 * Set up the DMA controller.
732 	 * Note that (dh->dh_len < sc_datalen)
733 	 */
734 
735 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
736 
737 	/* Disable DMA while we're setting up the transfer */
738 	csr &= ~SI_CSR_DMA_EN;
739 
740 	/* Reset FIFO (again?) */
741 	csr &= ~SI_CSR_FIFO_RES;		/* active low */
742 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
743 	csr |= SI_CSR_FIFO_RES;
744 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
745 
746 	/* Set direction (send/recv) */
747 	if (dh->dh_flags & SIDH_OUT) {
748 		csr |= SI_CSR_SEND;
749 	} else {
750 		csr &= ~SI_CSR_SEND;
751 	}
752 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
753 
754 	if (dva & 2) {
755 		csr |= SI_CSR_BPCON;
756 	} else {
757 		csr &= ~SI_CSR_BPCON;
758 	}
759 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
760 
761 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRH, (u_int16_t)(dva >> 16));
762 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRL, (u_int16_t)(dva & 0xFFFF));
763 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, (u_int16_t)(xlen >> 16));
764 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTL, (u_int16_t)(xlen & 0xFFFF));
765 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNTH, (u_int16_t)(xlen >> 16));
766 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNT, (u_int16_t)(xlen & 0xFFFF));
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 		SCI_CLR_INTR(ncr_sc);
775 		NCR5380_WRITE(ncr_sc, sci_icmd, SCI_ICMD_DATA);
776 
777 		mode = NCR5380_READ(ncr_sc, sci_mode);
778 		mode |= (SCI_MODE_DMA | SCI_MODE_DMA_IE);
779 		NCR5380_WRITE(ncr_sc, sci_mode, mode);
780 
781 		NCR5380_WRITE(ncr_sc, sci_dma_send, 0); /* start it */
782 	} else {
783 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_IN);
784 		SCI_CLR_INTR(ncr_sc);
785 		NCR5380_WRITE(ncr_sc, sci_icmd, 0);
786 
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 
791 		NCR5380_WRITE(ncr_sc, sci_irecv, 0); /* start it */
792 	}
793 
794 	/* Enable DMA engine */
795 	csr |= SI_CSR_DMA_EN;
796 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
797 
798 	ncr_sc->sc_state |= NCR_DOINGDMA;
799 
800 #ifdef	DEBUG
801 	if (si_debug & 2) {
802 		printf("si_dma_start: started, flags=0x%x\n",
803 			   ncr_sc->sc_state);
804 	}
805 #endif
806 }
807 
808 
809 void
810 si_dma_eop(ncr_sc)
811 	struct ncr5380_softc *ncr_sc;
812 {
813 
814 	/* Not needed - DMA was stopped prior to examining sci_csr */
815 }
816 
817 
818 void
819 si_dma_stop(ncr_sc)
820 	struct ncr5380_softc *ncr_sc;
821 {
822 	struct si_softc *sc = (struct si_softc *)ncr_sc;
823 	struct sci_req *sr = ncr_sc->sc_current;
824 	struct si_dma_handle *dh = sr->sr_dma_hand;
825 	int resid, ntrans;
826 	u_int16_t csr;
827 	u_int mode;
828 
829 	if ((ncr_sc->sc_state & NCR_DOINGDMA) == 0) {
830 #ifdef	DEBUG
831 		printf("si_dma_stop: dma not running\n");
832 #endif
833 		return;
834 	}
835 
836 	ncr_sc->sc_state &= ~NCR_DOINGDMA;
837 
838 	csr = SIREG_READ(ncr_sc, SIREG_CSR);
839 
840 	/* First, halt the DMA engine. */
841 	csr &= ~SI_CSR_DMA_EN;
842 	SIREG_WRITE(ncr_sc, SIREG_CSR, csr);
843 
844 	if (csr & (SI_CSR_DMA_CONFLICT | SI_CSR_DMA_BUS_ERR)) {
845 		printf("si: DMA error, csr=0x%x, reset\n", csr);
846 		sr->sr_xs->error = XS_DRIVER_STUFFUP;
847 		ncr_sc->sc_state |= NCR_ABORTING;
848 		si_reset_adapter(ncr_sc);
849 	}
850 
851 	/* Note that timeout may have set the error flag. */
852 	if (ncr_sc->sc_state & NCR_ABORTING)
853 		goto out;
854 
855 	/*
856 	 * Now try to figure out how much actually transferred
857 	 *
858 	 * The fifo_count does not reflect how many bytes were
859 	 * actually transferred for VME.
860 	 *
861 	 * SCSI-3 VME interface is a little funny on writes:
862 	 * if we have a disconnect, the dma has overshot by
863 	 * one byte and the resid needs to be incremented.
864 	 * Only happens for partial transfers.
865 	 * (Thanks to Matt Jacob)
866 	 */
867 
868 	resid = SIREG_READ(ncr_sc, SIREG_FIFO_CNTH) << 16;
869 	resid |= SIREG_READ(ncr_sc, SIREG_FIFO_CNT) & 0xFFFF;
870 	if (dh->dh_flags & SIDH_OUT)
871 		if ((resid > 0) && (resid < sc->sc_xlen))
872 			resid++;
873 	ntrans = sc->sc_xlen - resid;
874 
875 #ifdef	DEBUG
876 	if (si_debug & 2) {
877 		printf("si_dma_stop: resid=0x%x ntrans=0x%x\n",
878 		    resid, ntrans);
879 	}
880 #endif
881 
882 	if (ntrans > ncr_sc->sc_datalen)
883 		panic("si_dma_stop: excess transfer");
884 
885 	/* Adjust data pointer */
886 	ncr_sc->sc_dataptr += ntrans;
887 	ncr_sc->sc_datalen -= ntrans;
888 
889 #ifdef	DEBUG
890 	if (si_debug & 2) {
891 		printf("si_dma_stop: ntrans=0x%x\n", ntrans);
892 	}
893 #endif
894 
895 	/*
896 	 * After a read, we may need to clean-up
897 	 * "Left-over bytes" (yuck!)
898 	 */
899 	if (((dh->dh_flags & SIDH_OUT) == 0) &&
900 		((csr & SI_CSR_LOB) != 0))
901 	{
902 		char *cp = ncr_sc->sc_dataptr;
903 		u_int16_t bprh, bprl;
904 
905 		bprh = SIREG_READ(ncr_sc, SIREG_BPRH);
906 		bprl = SIREG_READ(ncr_sc, SIREG_BPRL);
907 
908 #ifdef DEBUG
909 		printf("si: got left-over bytes: bprh=%x, bprl=%x, csr=%x\n",
910 			bprh, bprl, csr);
911 #endif
912 
913 		if (csr & SI_CSR_BPCON) {
914 			/* have SI_CSR_BPCON */
915 			cp[-1] = (bprl & 0xff00) >> 8;
916 		} else {
917 			switch (csr & SI_CSR_LOB) {
918 			case SI_CSR_LOB_THREE:
919 				cp[-3] = (bprh & 0xff00) >> 8;
920 				cp[-2] = (bprh & 0x00ff);
921 				cp[-1] = (bprl & 0xff00) >> 8;
922 				break;
923 			case SI_CSR_LOB_TWO:
924 				cp[-2] = (bprh & 0xff00) >> 8;
925 				cp[-1] = (bprh & 0x00ff);
926 				break;
927 			case SI_CSR_LOB_ONE:
928 				cp[-1] = (bprh & 0xff00) >> 8;
929 				break;
930 			}
931 		}
932 	}
933 
934 out:
935 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRH, 0);
936 	SIREG_WRITE(ncr_sc, SIREG_DMA_ADDRL, 0);
937 
938 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTH, 0);
939 	SIREG_WRITE(ncr_sc, SIREG_DMA_CNTL, 0);
940 
941 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNTH, 0);
942 	SIREG_WRITE(ncr_sc, SIREG_FIFO_CNT, 0);
943 
944 	mode = NCR5380_READ(ncr_sc, sci_mode);
945 	/* Put SBIC back in PIO mode. */
946 	mode &= ~(SCI_MODE_DMA | SCI_MODE_DMA_IE);
947 	NCR5380_WRITE(ncr_sc, sci_mode, mode);
948 	NCR5380_WRITE(ncr_sc, sci_icmd, 0);
949 }
950