xref: /netbsd-src/sys/arch/sparc/dev/sw.c (revision 26d522fc31b1ca51e2670b7ad319572b5ca5a2a5)
1 /*	$NetBSD: sw.c,v 1.26 2023/01/23 22:16:44 andvar 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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * This file contains only the machine-dependent parts of the
34  * Sun4 SCSI driver.  (Autoconfig stuff and DMA functions.)
35  * The machine-independent parts are in ncr5380sbc.c
36  *
37  * Supported hardware includes:
38  * Sun "SCSI Weird" on OBIO (sw: Sun 4/100-series)
39  * Sun SCSI-3 on VME (si: Sun 4/200-series, others)
40  *
41  * The VME variant has a bit to enable or disable the DMA engine,
42  * but that bit also gates the interrupt line from the NCR5380!
43  * Therefore, in order to get any interrupt from the 5380, (i.e.
44  * for reselect) one must clear the DMA engine transfer count and
45  * then enable DMA.  This has the further complication that you
46  * CAN NOT touch the NCR5380 while the DMA enable bit is set, so
47  * we have to turn DMA back off before we even look at the 5380.
48  *
49  * What wonderfully whacky hardware this is!
50  *
51  * David Jones wrote the initial version of this module for NetBSD/sun3,
52  * which included support for the VME adapter only. (no reselection).
53  *
54  * Gordon Ross added support for the Sun 3 OBIO adapter, and re-worked
55  * both the VME and OBIO code to support disconnect/reselect.
56  * (Required figuring out the hardware "features" noted above.)
57  *
58  * The autoconfiguration boilerplate came from Adam Glass.
59  *
60  * Jason R. Thorpe ported the autoconfiguration and VME portions to
61  * NetBSD/sparc, and added initial support for the 4/100 "SCSI Weird",
62  * a wacky OBIO variant of the VME SCSI-3.  Many thanks to Chuck Cranor
63  * for lots of helpful tips and suggestions.  Thanks also to Paul Kranenburg
64  * and Chris Torek for bits of insight needed along the way.  Thanks to
65  * David Gilbert and Andrew Gillham who risked filesystem life-and-limb
66  * for the sake of testing.  Andrew Gillham helped work out the bugs
67  * the 4/100 DMA code.
68  */
69 
70 /*
71  * NOTE: support for the 4/100 "SCSI Weird" is not complete!  DMA
72  * works, but interrupts (and, thus, reselection) don't.  I don't know
73  * why, and I don't have a machine to test this on further.
74  *
75  * DMA, DMA completion interrupts, and reselection work fine on my
76  * 4/260 with modern SCSI-II disks attached.  I've had reports of
77  * reselection failing on Sun Shoebox-type configurations where
78  * there are multiple non-SCSI devices behind Emulex or Adaptec
79  * bridges.  These devices pre-date the SCSI-I spec, and might not
80  * behave the way the 5380 code expects.  For this reason, only
81  * DMA is enabled by default in this driver.
82  *
83  *	Jason R. Thorpe <thorpej@NetBSD.org>
84  *	December 8, 1995
85  */
86 
87 #include <sys/cdefs.h>
88 __KERNEL_RCSID(0, "$NetBSD: sw.c,v 1.26 2023/01/23 22:16:44 andvar Exp $");
89 
90 #include "opt_ddb.h"
91 
92 #include <sys/types.h>
93 #include <sys/param.h>
94 #include <sys/systm.h>
95 #include <sys/kernel.h>
96 #include <sys/kmem.h>
97 #include <sys/errno.h>
98 #include <sys/device.h>
99 #include <sys/buf.h>
100 
101 #include <sys/bus.h>
102 #include <machine/intr.h>
103 #include <machine/autoconf.h>
104 
105 #include <dev/scsipi/scsi_all.h>
106 #include <dev/scsipi/scsipi_all.h>
107 #include <dev/scsipi/scsipi_debug.h>
108 #include <dev/scsipi/scsiconf.h>
109 
110 #ifndef DDB
111 #define	Debugger()
112 #endif
113 
114 #ifndef DEBUG
115 #define DEBUG XXX
116 #endif
117 
118 #define COUNT_SW_LEFTOVERS	XXX	/* See sw DMA completion code */
119 
120 #include <dev/ic/ncr5380reg.h>
121 #include <dev/ic/ncr5380var.h>
122 
123 #include <sparc/dev/swreg.h>
124 
125 /*
126  * Transfers smaller than this are done using PIO
127  * (on assumption they're not worth DMA overhead)
128  */
129 #define	MIN_DMA_LEN 128
130 
131 /*
132  * Transfers larger than 65535 bytes need to be split-up.
133  * (Some of the FIFO logic has only 16 bits counters.)
134  * Make the size an integer multiple of the page size
135  * to avoid buf/cluster remap problems.  (paranoid?)
136  */
137 #define	MAX_DMA_LEN 0xE000
138 
139 #ifdef	DEBUG
140 int sw_debug = 0;
141 #endif
142 
143 /*
144  * This structure is used to keep track of mapped DMA requests.
145  */
146 struct sw_dma_handle {
147 	int 		dh_flags;
148 #define	SIDH_BUSY	0x01		/* This DH is in use */
149 #define	SIDH_OUT	0x02		/* DMA does data out (write) */
150 	u_char		*dh_addr;	/* KVA of start of buffer */
151 	int 		dh_maplen;	/* Original data length */
152 	long		dh_startingpa;	/* PA of buffer; for "sw" */
153 	bus_dmamap_t	dh_dmamap;
154 #define dh_dvma	dh_dmamap->dm_segs[0].ds_addr /* VA of buffer in DVMA space */
155 };
156 
157 /*
158  * The first structure member has to be the ncr5380_softc
159  * so we can just cast to go back and fourth between them.
160  */
161 struct sw_softc {
162 	struct ncr5380_softc	ncr_sc;
163 	bus_space_tag_t		sc_bustag;	/* bus tags */
164 	bus_dma_tag_t		sc_dmatag;
165 
166 	struct sw_dma_handle *sc_dma;
167 	int		sc_xlen;	/* length of current DMA segment. */
168 	int		sc_options;	/* options for this instance. */
169 };
170 
171 /*
172  * Options.  By default, DMA is enabled and DMA completion interrupts
173  * and reselect are disabled.  You may enable additional features
174  * the `flags' directive in your kernel's configuration file.
175  *
176  * Alternatively, you can patch your kernel with DDB or some other
177  * mechanism.  The sc_options member of the softc is OR'd with
178  * the value in sw_options.
179  *
180  * On the "sw", interrupts (and thus) reselection don't work, so they're
181  * disabled by default.  DMA is still a little dangerous, too.
182  *
183  * Note, there's a separate sw_options to make life easier.
184  */
185 #define	SW_ENABLE_DMA	0x01	/* Use DMA (maybe polled) */
186 #define	SW_DMA_INTR	0x02	/* DMA completion interrupts */
187 #define	SW_DO_RESELECT	0x04	/* Allow disconnect/reselect */
188 #define	SW_OPTIONS_MASK	(SW_ENABLE_DMA|SW_DMA_INTR|SW_DO_RESELECT)
189 #define SW_OPTIONS_BITS	"\10\3RESELECT\2DMA_INTR\1DMA"
190 int sw_options = SW_ENABLE_DMA;
191 
192 static int	sw_match(device_t, cfdata_t, void *);
193 static void	sw_attach(device_t, device_t, void *);
194 static int	sw_intr(void *);
195 static void	sw_reset_adapter(struct ncr5380_softc *);
196 static void	sw_minphys(struct buf *);
197 
198 void	sw_dma_alloc(struct ncr5380_softc *);
199 void	sw_dma_free(struct ncr5380_softc *);
200 void	sw_dma_poll(struct ncr5380_softc *);
201 
202 void	sw_dma_setup(struct ncr5380_softc *);
203 void	sw_dma_start(struct ncr5380_softc *);
204 void	sw_dma_eop(struct ncr5380_softc *);
205 void	sw_dma_stop(struct ncr5380_softc *);
206 
207 void	sw_intr_on(struct ncr5380_softc *);
208 void	sw_intr_off(struct ncr5380_softc *);
209 
210 /* Shorthand bus space access */
211 #define SWREG_READ(sc, index) \
212 	bus_space_read_4((sc)->sc_regt, (sc)->sc_regh, index)
213 #define SWREG_WRITE(sc, index, v) \
214 	bus_space_write_4((sc)->sc_regt, (sc)->sc_regh, index, v)
215 
216 
217 /* The Sun "SCSI Weird" 4/100 obio controller. */
218 CFATTACH_DECL_NEW(sw, sizeof(struct sw_softc),
219     sw_match, sw_attach, NULL, NULL);
220 
221 static int
sw_match(device_t parent,cfdata_t cf,void * aux)222 sw_match(device_t parent, cfdata_t cf, void *aux)
223 {
224 	union obio_attach_args *uoba = aux;
225 	struct obio4_attach_args *oba;
226 
227 	/* Nothing but a Sun 4/100 is going to have these devices. */
228 	if (cpuinfo.cpu_type != CPUTYP_4_100)
229 		return (0);
230 
231 	if (uoba->uoba_isobio4 == 0)
232 		return (0);
233 
234 	/* Make sure there is something there... */
235 	oba = &uoba->uoba_oba4;
236 	return (bus_space_probe(oba->oba_bustag, oba->oba_paddr,
237 				1,	/* probe size */
238 				1,	/* offset */
239 				0,	/* flags */
240 				NULL, NULL));
241 }
242 
243 static void
sw_attach(device_t parent,device_t self,void * aux)244 sw_attach(device_t parent, device_t self, void *aux)
245 {
246 	struct sw_softc *sc = device_private(self);
247 	struct ncr5380_softc *ncr_sc = &sc->ncr_sc;
248 	union obio_attach_args *uoba = aux;
249 	struct obio4_attach_args *oba = &uoba->uoba_oba4;
250 	bus_space_handle_t bh;
251 	char bits[64];
252 	int i;
253 
254 	ncr_sc->sc_dev = self;
255 	sc->sc_dmatag = oba->oba_dmatag;
256 
257 	/* Map the controller registers. */
258 	if (bus_space_map(oba->oba_bustag, oba->oba_paddr,
259 			  SWREG_BANK_SZ,
260 			  BUS_SPACE_MAP_LINEAR,
261 			  &bh) != 0) {
262 		aprint_error(": cannot map registers\n");
263 		return;
264 	}
265 
266 	ncr_sc->sc_regt = oba->oba_bustag;
267 	ncr_sc->sc_regh = bh;
268 
269 	sc->sc_options = sw_options;
270 
271 	ncr_sc->sc_dma_setup = sw_dma_setup;
272 	ncr_sc->sc_dma_start = sw_dma_start;
273 	ncr_sc->sc_dma_eop   = sw_dma_stop;
274 	ncr_sc->sc_dma_stop  = sw_dma_stop;
275 	ncr_sc->sc_intr_on   = sw_intr_on;
276 	ncr_sc->sc_intr_off  = sw_intr_off;
277 
278 	/*
279 	 * Establish interrupt channel.
280 	 * Default interrupt priority always is 3.  At least, that's
281 	 * what my board seems to be at.  --thorpej
282 	 */
283 	if (oba->oba_pri == -1)
284 		oba->oba_pri = 3;
285 
286 	(void)bus_intr_establish(oba->oba_bustag, oba->oba_pri, IPL_BIO,
287 				 sw_intr, sc);
288 
289 	aprint_normal(" pri %d\n", oba->oba_pri);
290 
291 
292 	/*
293 	 * Pull in the options flags.  Allow the user to completely
294 	 * override the default values.
295 	 */
296 	if ((device_cfdata(self)->cf_flags & SW_OPTIONS_MASK) != 0)
297 		sc->sc_options =
298 		    device_cfdata(self)->cf_flags & SW_OPTIONS_MASK;
299 
300 	/*
301 	 * Initialize fields used by the MI code
302 	 */
303 
304 	/* NCR5380 register bank offsets */
305 	ncr_sc->sci_r0 = 0;
306 	ncr_sc->sci_r1 = 1;
307 	ncr_sc->sci_r2 = 2;
308 	ncr_sc->sci_r3 = 3;
309 	ncr_sc->sci_r4 = 4;
310 	ncr_sc->sci_r5 = 5;
311 	ncr_sc->sci_r6 = 6;
312 	ncr_sc->sci_r7 = 7;
313 
314 	ncr_sc->sc_rev = NCR_VARIANT_NCR5380;
315 
316 	/*
317 	 * MD function pointers used by the MI code.
318 	 */
319 	ncr_sc->sc_pio_out = ncr5380_pio_out;
320 	ncr_sc->sc_pio_in =  ncr5380_pio_in;
321 	ncr_sc->sc_dma_alloc = sw_dma_alloc;
322 	ncr_sc->sc_dma_free  = sw_dma_free;
323 	ncr_sc->sc_dma_poll  = sw_dma_poll;
324 
325 	ncr_sc->sc_flags = 0;
326 	if ((sc->sc_options & SW_DO_RESELECT) == 0)
327 		ncr_sc->sc_no_disconnect = 0xFF;
328 	if ((sc->sc_options & SW_DMA_INTR) == 0)
329 		ncr_sc->sc_flags |= NCR5380_FORCE_POLLING;
330 	ncr_sc->sc_min_dma_len = MIN_DMA_LEN;
331 
332 
333 	/*
334 	 * Allocate DMA handles.
335 	 */
336 	i = SCI_OPENINGS * sizeof(struct sw_dma_handle);
337 	sc->sc_dma = kmem_alloc(i, KM_SLEEP);
338 
339 	for (i = 0; i < SCI_OPENINGS; i++) {
340 		sc->sc_dma[i].dh_flags = 0;
341 
342 		/* Allocate a DMA handle */
343 		if (bus_dmamap_create(
344 				sc->sc_dmatag,	/* tag */
345 				MAXPHYS,	/* size */
346 				1,		/* nsegments */
347 				MAXPHYS,	/* maxsegsz */
348 				0,		/* boundary */
349 				BUS_DMA_NOWAIT,
350 				&sc->sc_dma[i].dh_dmamap) != 0) {
351 
352 			aprint_error_dev(self, "DMA buffer map create error\n");
353 			return;
354 		}
355 	}
356 
357 	if (sc->sc_options) {
358 		snprintb(bits, sizeof(bits),
359 		    SW_OPTIONS_BITS, sc->sc_options);
360 		aprint_normal_dev(self, "options=%s\n", bits);
361 	}
362 
363 	ncr_sc->sc_channel.chan_id = 7;
364 	ncr_sc->sc_adapter.adapt_minphys = sw_minphys;
365 
366 	/* Initialize sw board */
367 	sw_reset_adapter(ncr_sc);
368 
369 	/* Attach the ncr5380 chip driver */
370 	ncr5380_attach(ncr_sc);
371 }
372 
373 static void
sw_minphys(struct buf * bp)374 sw_minphys(struct buf *bp)
375 {
376 
377 	if (bp->b_bcount > MAX_DMA_LEN) {
378 #ifdef DEBUG
379 		if (sw_debug) {
380 			printf("sw_minphys len = 0x%x.\n", MAX_DMA_LEN);
381 			Debugger();
382 		}
383 #endif
384 		bp->b_bcount = MAX_DMA_LEN;
385 	}
386 	minphys(bp);
387 }
388 
389 #define CSR_WANT (SW_CSR_SBC_IP | SW_CSR_DMA_IP | \
390 	SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR )
391 
392 static int
sw_intr(void * arg)393 sw_intr(void *arg)
394 {
395 	struct sw_softc *sc = arg;
396 	struct ncr5380_softc *ncr_sc = &sc->ncr_sc;
397 	int dma_error, claimed;
398 	u_short csr;
399 
400 	claimed = 0;
401 	dma_error = 0;
402 
403 	/* SBC interrupt? DMA interrupt? */
404 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
405 
406 	NCR_TRACE("sw_intr: csr=0x%x\n", csr);
407 
408 	if (csr & SW_CSR_DMA_CONFLICT) {
409 		dma_error |= SW_CSR_DMA_CONFLICT;
410 		printf("%s: DMA conflict\n", __func__);
411 	}
412 	if (csr & SW_CSR_DMA_BUS_ERR) {
413 		dma_error |= SW_CSR_DMA_BUS_ERR;
414 		printf("%s: DMA bus error\n", __func__);
415 	}
416 	if (dma_error) {
417 		if (sc->ncr_sc.sc_state & NCR_DOINGDMA)
418 			sc->ncr_sc.sc_state |= NCR_ABORTING;
419 		/* Make sure we will call the main isr. */
420 		csr |= SW_CSR_DMA_IP;
421 	}
422 
423 	if (csr & (SW_CSR_SBC_IP | SW_CSR_DMA_IP)) {
424 		claimed = ncr5380_intr(&sc->ncr_sc);
425 #ifdef DEBUG
426 		if (!claimed) {
427 			printf("%s: spurious from SBC\n", __func__);
428 			if (sw_debug & 4) {
429 				Debugger();	/* XXX */
430 			}
431 		}
432 #endif
433 	}
434 
435 	return claimed;
436 }
437 
438 
439 static void
sw_reset_adapter(struct ncr5380_softc * ncr_sc)440 sw_reset_adapter(struct ncr5380_softc *ncr_sc)
441 {
442 
443 #ifdef	DEBUG
444 	if (sw_debug) {
445 		printf("%s\n", __func__);
446 	}
447 #endif
448 
449 	/*
450 	 * The reset bits in the CSR are active low.
451 	 */
452 	SWREG_WRITE(ncr_sc, SWREG_CSR, 0);
453 	delay(10);
454 	SWREG_WRITE(ncr_sc, SWREG_CSR, SW_CSR_SCSI_RES);
455 
456 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
457 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
458 	delay(10);
459 	SWREG_WRITE(ncr_sc, SWREG_CSR, SW_CSR_SCSI_RES | SW_CSR_INTR_EN);
460 
461 	SCI_CLR_INTR(ncr_sc);
462 }
463 
464 
465 /*****************************************************************
466  * Common functions for DMA
467  ****************************************************************/
468 
469 /*
470  * Allocate a DMA handle and put it in sc->sc_dma.  Prepare
471  * for DMA transfer.  On the Sun4, this means mapping the buffer
472  * into DVMA space.
473  */
474 void
sw_dma_alloc(struct ncr5380_softc * ncr_sc)475 sw_dma_alloc(struct ncr5380_softc *ncr_sc)
476 {
477 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
478 	struct sci_req *sr = ncr_sc->sc_current;
479 	struct scsipi_xfer *xs = sr->sr_xs;
480 	struct sw_dma_handle *dh;
481 	int i, xlen;
482 	u_long addr;
483 
484 #ifdef DIAGNOSTIC
485 	if (sr->sr_dma_hand != NULL)
486 		panic("%s: already have DMA handle", __func__);
487 #endif
488 
489 #if 1	/* XXX - Temporary */
490 	/* XXX - In case we think DMA is completely broken... */
491 	if ((sc->sc_options & SW_ENABLE_DMA) == 0)
492 		return;
493 #endif
494 
495 	addr = (u_long)ncr_sc->sc_dataptr;
496 	xlen = ncr_sc->sc_datalen;
497 
498 	/* If the DMA start addr is misaligned then do PIO */
499 	if ((addr & 1) || (xlen & 1)) {
500 		printf("%s: misaligned.\n", __func__);
501 		return;
502 	}
503 
504 	/* Make sure our caller checked sc_min_dma_len. */
505 	if (xlen < MIN_DMA_LEN)
506 		panic("%s: xlen=0x%x", __func__, xlen);
507 
508 	/* Find free DMA handle.  Guaranteed to find one since we have
509 	   as many DMA handles as the driver has processes. */
510 	for (i = 0; i < SCI_OPENINGS; i++) {
511 		if ((sc->sc_dma[i].dh_flags & SIDH_BUSY) == 0)
512 			goto found;
513 	}
514 	panic("sw: no free DMA handles.");
515 
516 found:
517 	dh = &sc->sc_dma[i];
518 	dh->dh_flags = SIDH_BUSY;
519 	dh->dh_addr = (u_char *)addr;
520 	dh->dh_maplen  = xlen;
521 
522 	/* Copy the "write" flag for convenience. */
523 	if ((xs->xs_control & XS_CTL_DATA_OUT) != 0)
524 		dh->dh_flags |= SIDH_OUT;
525 
526 	/*
527 	 * Double-map the buffer into DVMA space.  If we can't re-map
528 	 * the buffer, we print a warning and fall back to PIO mode.
529 	 *
530 	 * NOTE: it is not safe to sleep here!
531 	 */
532 	if (bus_dmamap_load(sc->sc_dmatag, dh->dh_dmamap,
533 			    (void *)addr, xlen, NULL, BUS_DMA_NOWAIT) != 0) {
534 		/* Can't remap segment */
535 		printf("%s: can't remap 0x%lx/0x%x, doing PIO\n",
536 		    __func__, addr, dh->dh_maplen);
537 		dh->dh_flags = 0;
538 		return;
539 	}
540 	bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap, addr, xlen,
541 			(dh->dh_flags & SIDH_OUT)
542 				? BUS_DMASYNC_PREWRITE
543 				: BUS_DMASYNC_PREREAD);
544 
545 	/* success */
546 	sr->sr_dma_hand = dh;
547 }
548 
549 
550 void
sw_dma_free(struct ncr5380_softc * ncr_sc)551 sw_dma_free(struct ncr5380_softc *ncr_sc)
552 {
553 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
554 	struct sci_req *sr = ncr_sc->sc_current;
555 	struct sw_dma_handle *dh = sr->sr_dma_hand;
556 
557 #ifdef DIAGNOSTIC
558 	if (dh == NULL)
559 		panic("%s: no DMA handle", __func__);
560 #endif
561 
562 	if (ncr_sc->sc_state & NCR_DOINGDMA)
563 		panic("%s: free while in progress", __func__);
564 
565 	if (dh->dh_flags & SIDH_BUSY) {
566 		/* Give back the DVMA space. */
567 		bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap,
568 				dh->dh_dvma, dh->dh_maplen,
569 				(dh->dh_flags & SIDH_OUT)
570 					? BUS_DMASYNC_POSTWRITE
571 					: BUS_DMASYNC_POSTREAD);
572 		bus_dmamap_unload(sc->sc_dmatag, dh->dh_dmamap);
573 		dh->dh_flags = 0;
574 	}
575 	sr->sr_dma_hand = NULL;
576 }
577 
578 
579 /*
580  * Poll (spin-wait) for DMA completion.
581  * Called right after xx_dma_start(), and
582  * xx_dma_stop() will be called next.
583  * Same for either VME or OBIO.
584  */
585 void
sw_dma_poll(struct ncr5380_softc * ncr_sc)586 sw_dma_poll(struct ncr5380_softc *ncr_sc)
587 {
588 	struct sci_req *sr = ncr_sc->sc_current;
589 	int tmo, csr_mask, csr;
590 
591 	/* Make sure DMA started successfully. */
592 	if (ncr_sc->sc_state & NCR_ABORTING)
593 		return;
594 
595 	csr_mask = SW_CSR_SBC_IP | SW_CSR_DMA_IP |
596 	    SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR;
597 
598 	tmo = 50000;	/* X100 = 5 sec. */
599 	for (;;) {
600 		csr = SWREG_READ(ncr_sc, SWREG_CSR);
601 		if (csr & csr_mask)
602 			break;
603 		if (--tmo <= 0) {
604 			printf("%s: DMA timeout (while polling)\n",
605 			    device_xname(ncr_sc->sc_dev));
606 			/* Indicate timeout as MI code would. */
607 			sr->sr_flags |= SR_OVERDUE;
608 			break;
609 		}
610 		delay(100);
611 	}
612 
613 #ifdef	DEBUG
614 	if (sw_debug) {
615 		printf("%s: done, csr=0x%x\n", __func__, csr);
616 	}
617 #endif
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  * XXX THIS MIGHT NOT WORK RIGHT!
629  */
630 void
sw_intr_on(struct ncr5380_softc * ncr_sc)631 sw_intr_on(struct ncr5380_softc *ncr_sc)
632 {
633 	uint32_t csr;
634 
635 	sw_dma_setup(ncr_sc);
636 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
637 	csr |= SW_CSR_DMA_EN;	/* XXX - this bit is for vme only?! */
638 	SWREG_WRITE(ncr_sc, SWREG_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  * XXX THIS MIGHT NOT WORK RIGHT!
646  */
647 void
sw_intr_off(struct ncr5380_softc * ncr_sc)648 sw_intr_off(struct ncr5380_softc *ncr_sc)
649 {
650 	uint32_t csr;
651 
652 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
653 	csr &= ~SW_CSR_DMA_EN;
654 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
655 }
656 
657 
658 /*
659  * This function is called during the COMMAND or MSG_IN phase
660  * that precedes a DATA_IN or DATA_OUT phase, in case we need
661  * to setup the DMA engine before the bus enters a DATA phase.
662  *
663  * On the OBIO version we just clear the DMA count and address
664  * here (to make sure it stays idle) and do the real setup
665  * later, in dma_start.
666  */
667 void
sw_dma_setup(struct ncr5380_softc * ncr_sc)668 sw_dma_setup(struct ncr5380_softc *ncr_sc)
669 {
670 	uint32_t csr;
671 
672 	/* No FIFO to reset on "sw". */
673 
674 	/* Set direction (assume recv here) */
675 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
676 	csr &= ~SW_CSR_SEND;
677 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
678 
679 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
680 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
681 }
682 
683 
684 void
sw_dma_start(struct ncr5380_softc * ncr_sc)685 sw_dma_start(struct ncr5380_softc *ncr_sc)
686 {
687 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
688 	struct sci_req *sr = ncr_sc->sc_current;
689 	struct sw_dma_handle *dh = sr->sr_dma_hand;
690 	u_long dva;
691 	int xlen, adj, adjlen;
692 	u_int mode;
693 	uint32_t csr;
694 
695 	/*
696 	 * Get the DVMA mapping for this segment.
697 	 */
698 	dva = (u_long)(dh->dh_dvma);
699 	if (dva & 1)
700 		panic("%s: bad dva=0x%lx", __func__, dva);
701 
702 	xlen = ncr_sc->sc_datalen;
703 	xlen &= ~1;
704 	sc->sc_xlen = xlen;	/* XXX: or less... */
705 
706 #ifdef	DEBUG
707 	if (sw_debug & 2) {
708 		printf("%s: dh=%p, dva=0x%lx, xlen=%d\n",
709 		    __func__, dh, dva, xlen);
710 	}
711 #endif
712 
713 	/*
714 	 * Set up the DMA controller.
715 	 * Note that (dh->dh_len < sc_datalen)
716 	 */
717 
718 	/* Set direction (send/recv) */
719 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
720 	if (dh->dh_flags & SIDH_OUT) {
721 		csr |= SW_CSR_SEND;
722 	} else {
723 		csr &= ~SW_CSR_SEND;
724 	}
725 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
726 
727 	/*
728 	 * The "sw" needs longword aligned transfers.  We
729 	 * detect a shortword aligned transfer here, and adjust the
730 	 * DMA transfer by 2 bytes.  These two bytes are read/written
731 	 * in PIO mode just before the DMA is started.
732 	 */
733 	adj = 0;
734 	if (dva & 2) {
735 		adj = 2;
736 #ifdef DEBUG
737 		if (sw_debug & 2)
738 			printf("%s: adjusted up %d bytes\n", __func__, adj);
739 #endif
740 	}
741 
742 	/* We have to frob the address on the "sw". */
743 	dh->dh_startingpa = (dva | 0xF00000);
744 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, (u_int)(dh->dh_startingpa + adj));
745 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, xlen - adj);
746 
747 	/*
748 	 * Acknowledge the phase change.  (After DMA setup!)
749 	 * Put the SBIC into DMA mode, and start the transfer.
750 	 */
751 	if (dh->dh_flags & SIDH_OUT) {
752 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_OUT);
753 		if (adj) {
754 			adjlen = ncr5380_pio_out(ncr_sc, PHASE_DATA_OUT,
755 			    adj, dh->dh_addr);
756 			if (adjlen != adj)
757 				printf("%s: bad outgoing adj, %d != %d\n",
758 				    device_xname(ncr_sc->sc_dev), adjlen, adj);
759 		}
760 		SCI_CLR_INTR(ncr_sc);
761 		NCR5380_WRITE(ncr_sc, sci_icmd, SCI_ICMD_DATA);
762 		mode = NCR5380_READ(ncr_sc, sci_mode);
763 		mode |= (SCI_MODE_DMA | SCI_MODE_DMA_IE);
764 		NCR5380_WRITE(ncr_sc, sci_mode, mode);
765 		NCR5380_WRITE(ncr_sc, sci_dma_send, 0); 	/* start it */
766 	} else {
767 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_IN);
768 		if (adj) {
769 			adjlen = ncr5380_pio_in(ncr_sc, PHASE_DATA_IN,
770 			    adj, dh->dh_addr);
771 			if (adjlen != adj)
772 				printf("%s: bad incoming adj, %d != %d\n",
773 				    device_xname(ncr_sc->sc_dev), adjlen, adj);
774 		}
775 		SCI_CLR_INTR(ncr_sc);
776 		NCR5380_WRITE(ncr_sc, sci_icmd, 0);
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 		NCR5380_WRITE(ncr_sc, sci_irecv, 0); 	/* start it */
781 	}
782 
783 	/* Let'er rip! */
784 	csr |= SW_CSR_DMA_EN;
785 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
786 
787 	ncr_sc->sc_state |= NCR_DOINGDMA;
788 
789 #ifdef	DEBUG
790 	if (sw_debug & 2) {
791 		printf("%s: started, flags=0x%x\n",
792 		    __func__, ncr_sc->sc_state);
793 	}
794 #endif
795 }
796 
797 
798 void
sw_dma_eop(struct ncr5380_softc * ncr_sc)799 sw_dma_eop(struct ncr5380_softc *ncr_sc)
800 {
801 
802 	/* Not needed - DMA was stopped prior to examining sci_csr */
803 }
804 
805 #if (defined(DEBUG) || defined(DIAGNOSTIC)) && !defined(COUNT_SW_LEFTOVERS)
806 #define COUNT_SW_LEFTOVERS
807 #endif
808 #ifdef COUNT_SW_LEFTOVERS
809 /*
810  * Let's find out how often these occur.  Read these with DDB from time
811  * to time.
812  */
813 int	sw_3_leftover = 0;
814 int	sw_2_leftover = 0;
815 int	sw_1_leftover = 0;
816 int	sw_0_leftover = 0;
817 #endif
818 
819 void
sw_dma_stop(struct ncr5380_softc * ncr_sc)820 sw_dma_stop(struct ncr5380_softc *ncr_sc)
821 {
822 	struct sci_req *sr = ncr_sc->sc_current;
823 	struct sw_dma_handle *dh = sr->sr_dma_hand;
824 	int ntrans = 0, dva;
825 	u_int mode;
826 	uint32_t csr;
827 
828 	if ((ncr_sc->sc_state & NCR_DOINGDMA) == 0) {
829 #ifdef	DEBUG
830 		printf("%s: DMA not running\n", __func__);
831 #endif
832 		return;
833 	}
834 	ncr_sc->sc_state &= ~NCR_DOINGDMA;
835 
836 	/* First, halt the DMA engine. */
837 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
838 	csr &= ~SW_CSR_DMA_EN;
839 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
840 
841 	/*
842 	 * XXX HARDWARE BUG!
843 	 * Apparently, some early 4/100 SCSI controllers had a hardware
844 	 * bug that caused the controller to do illegal memory access.
845 	 * We see this as SW_CSR_DMA_BUS_ERR (makes sense).  To work around
846 	 * this, we simply need to clean up after ourselves ... there will
847 	 * be as many as 3 bytes left over.  Since we clean up "left-over"
848 	 * bytes on every read anyway, we just continue to chug along
849 	 * if SW_CSR_DMA_BUS_ERR is asserted.  (This was probably worked
850 	 * around in hardware later with the "left-over byte" indicator
851 	 * in the VME controller.)
852 	 */
853 #if 0
854 	if (csr & (SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR))
855 #else
856 	if (csr & (SW_CSR_DMA_CONFLICT))
857 #endif
858 	{
859 		printf("sw: DMA error, csr=0x%x, reset\n", csr);
860 		sr->sr_xs->error = XS_DRIVER_STUFFUP;
861 		ncr_sc->sc_state |= NCR_ABORTING;
862 		sw_reset_adapter(ncr_sc);
863 	}
864 
865 	/* Note that timeout may have set the error flag. */
866 	if (ncr_sc->sc_state & NCR_ABORTING)
867 		goto out;
868 
869 	/*
870 	 * Now try to figure out how much actually transferred
871 	 *
872 	 * The "sw" doesn't have a FIFO or a bcr, so we've stored
873 	 * the starting PA of the transfer in the DMA handle,
874 	 * and subtract it from the ending PA left in the dma_addr
875 	 * register.
876 	 */
877 	dva = SWREG_READ(ncr_sc, SWREG_DMA_ADDR);
878 	ntrans = (dva - dh->dh_startingpa);
879 
880 #ifdef	DEBUG
881 	if (sw_debug & 2) {
882 		printf("%s: ntrans=0x%x\n", __func__, ntrans);
883 	}
884 #endif
885 
886 	if (ntrans > ncr_sc->sc_datalen)
887 		panic("%s: excess transfer", __func__);
888 
889 	/* Adjust data pointer */
890 	ncr_sc->sc_dataptr += ntrans;
891 	ncr_sc->sc_datalen -= ntrans;
892 
893 	/*
894 	 * After a read, we may need to clean-up
895 	 * "Left-over bytes"  (yuck!)  The "sw" doesn't
896 	 * have a "left-over" indicator, so we have to so
897 	 * this no matter what.  Ick.
898 	 */
899 	if ((dh->dh_flags & SIDH_OUT) == 0) {
900 		char *cp = ncr_sc->sc_dataptr;
901 		uint32_t bpr;
902 
903 		bpr = SWREG_READ(ncr_sc, SWREG_BPR);
904 
905 		switch (dva & 3) {
906 		case 3:
907 			cp[0] = (bpr & 0xff000000) >> 24;
908 			cp[1] = (bpr & 0x00ff0000) >> 16;
909 			cp[2] = (bpr & 0x0000ff00) >> 8;
910 #ifdef COUNT_SW_LEFTOVERS
911 			++sw_3_leftover;
912 #endif
913 			break;
914 
915 		case 2:
916 			cp[0] = (bpr & 0xff000000) >> 24;
917 			cp[1] = (bpr & 0x00ff0000) >> 16;
918 #ifdef COUNT_SW_LEFTOVERS
919 			++sw_2_leftover;
920 #endif
921 			break;
922 
923 		case 1:
924 			cp[0] = (bpr & 0xff000000) >> 24;
925 #ifdef COUNT_SW_LEFTOVERS
926 			++sw_1_leftover;
927 #endif
928 			break;
929 
930 #ifdef COUNT_SW_LEFTOVERS
931 		default:
932 			++sw_0_leftover;
933 			break;
934 #endif
935 		}
936 	}
937 
938  out:
939 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
940 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
941 
942 	/* Put SBIC back in PIO mode. */
943 	mode = NCR5380_READ(ncr_sc, sci_mode);
944 	mode &= ~(SCI_MODE_DMA | SCI_MODE_DMA_IE);
945 	NCR5380_WRITE(ncr_sc, sci_mode, mode);
946 	NCR5380_WRITE(ncr_sc, sci_icmd, 0);
947 
948 #ifdef DEBUG
949 	if (sw_debug & 2) {
950 		printf("%s: ntrans=0x%x\n", __func__, ntrans);
951 	}
952 #endif
953 }
954