xref: /netbsd-src/sys/dev/pci/pcscp.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: pcscp.c,v 1.44 2008/08/28 16:47:10 tsutsui Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center; Izumi Tsutsui.
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  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * pcscp.c: device dependent code for AMD Am53c974 (PCscsi-PCI)
35  * written by Izumi Tsutsui <tsutsui@NetBSD.org>
36  *
37  * Technical manual available at
38  * http://www.amd.com/files/connectivitysolutions/networking/archivednetworking/19113.pdf
39  */
40 
41 #include <sys/cdefs.h>
42 __KERNEL_RCSID(0, "$NetBSD: pcscp.c,v 1.44 2008/08/28 16:47:10 tsutsui Exp $");
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/device.h>
47 #include <sys/buf.h>
48 
49 #include <sys/bus.h>
50 #include <sys/intr.h>
51 
52 #include <uvm/uvm_extern.h>
53 
54 #include <dev/scsipi/scsipi_all.h>
55 #include <dev/scsipi/scsi_all.h>
56 #include <dev/scsipi/scsiconf.h>
57 
58 #include <dev/pci/pcireg.h>
59 #include <dev/pci/pcivar.h>
60 #include <dev/pci/pcidevs.h>
61 
62 #include <dev/ic/ncr53c9xreg.h>
63 #include <dev/ic/ncr53c9xvar.h>
64 
65 #include <dev/pci/pcscpreg.h>
66 
67 #define IO_MAP_REG	0x10
68 
69 struct pcscp_softc {
70 	struct ncr53c9x_softc sc_ncr53c9x;	/* glue to MI code */
71 
72 	bus_space_tag_t sc_st;		/* bus space tag */
73 	bus_space_handle_t sc_sh;	/* bus space handle */
74 	void *sc_ih;			/* interrupt cookie */
75 
76 	bus_dma_tag_t sc_dmat;		/* DMA tag */
77 
78 	bus_dmamap_t sc_xfermap;	/* DMA map for transfers */
79 
80 	uint32_t *sc_mdladdr;		/* MDL array */
81 	bus_dmamap_t sc_mdldmap;	/* MDL DMA map */
82 
83 	int	sc_active;		/* DMA state */
84 	int	sc_datain;		/* DMA Data Direction */
85 	size_t	sc_dmasize;		/* DMA size */
86 	uint8_t	**sc_dmaaddr;		/* DMA address */
87 	size_t	*sc_dmalen;		/* DMA length */
88 };
89 
90 #define	READ_DMAREG(sc, reg) \
91 	bus_space_read_4((sc)->sc_st, (sc)->sc_sh, (reg))
92 #define	WRITE_DMAREG(sc, reg, var) \
93 	bus_space_write_4((sc)->sc_st, (sc)->sc_sh, (reg), (var))
94 
95 #define	PCSCP_READ_REG(sc, reg)	\
96 	bus_space_read_1((sc)->sc_st, (sc)->sc_sh, (reg) << 2)
97 #define	PCSCP_WRITE_REG(sc, reg, val)	\
98 	bus_space_write_1((sc)->sc_st, (sc)->sc_sh, (reg) << 2, (val))
99 
100 
101 static int pcscp_match(device_t, cfdata_t, void *);
102 static void pcscp_attach(device_t, device_t, void *);
103 
104 CFATTACH_DECL_NEW(pcscp, sizeof(struct pcscp_softc),
105     pcscp_match, pcscp_attach, NULL, NULL);
106 
107 /*
108  * Functions and the switch for the MI code.
109  */
110 
111 static uint8_t	pcscp_read_reg(struct ncr53c9x_softc *, int);
112 static void	pcscp_write_reg(struct ncr53c9x_softc *, int, uint8_t);
113 static int	pcscp_dma_isintr(struct ncr53c9x_softc *);
114 static void	pcscp_dma_reset(struct ncr53c9x_softc *);
115 static int	pcscp_dma_intr(struct ncr53c9x_softc *);
116 static int	pcscp_dma_setup(struct ncr53c9x_softc *, uint8_t **, size_t *,
117 		    int, size_t *);
118 static void	pcscp_dma_go(struct ncr53c9x_softc *);
119 static void	pcscp_dma_stop(struct ncr53c9x_softc *);
120 static int	pcscp_dma_isactive(struct ncr53c9x_softc *);
121 
122 static struct ncr53c9x_glue pcscp_glue = {
123 	pcscp_read_reg,
124 	pcscp_write_reg,
125 	pcscp_dma_isintr,
126 	pcscp_dma_reset,
127 	pcscp_dma_intr,
128 	pcscp_dma_setup,
129 	pcscp_dma_go,
130 	pcscp_dma_stop,
131 	pcscp_dma_isactive,
132 	NULL,			/* gl_clear_latched_intr */
133 };
134 
135 static int
136 pcscp_match(device_t parent, cfdata_t cf, void *aux)
137 {
138 	struct pci_attach_args *pa = aux;
139 
140 	if (PCI_VENDOR(pa->pa_id) != PCI_VENDOR_AMD)
141 		return 0;
142 
143 	switch (PCI_PRODUCT(pa->pa_id)) {
144 	case PCI_PRODUCT_AMD_PCSCSI_PCI:
145 		return 1;
146 	}
147 	return 0;
148 }
149 
150 /*
151  * Attach this instance, and then all the sub-devices
152  */
153 static void
154 pcscp_attach(device_t parent, device_t self, void *aux)
155 {
156 	struct pcscp_softc *esc = device_private(self);
157 	struct ncr53c9x_softc *sc = &esc->sc_ncr53c9x;
158 	struct pci_attach_args *pa = aux;
159 	bus_space_tag_t iot;
160 	bus_space_handle_t ioh;
161 	pci_intr_handle_t ih;
162 	const char *intrstr;
163 	pcireg_t csr;
164 	bus_dma_segment_t seg;
165 	int error, rseg;
166 	char devinfo[256];
167 
168 	sc->sc_dev = self;
169 	pci_devinfo(pa->pa_id, pa->pa_class, 0, devinfo, sizeof(devinfo));
170 	aprint_normal(": %s\n", devinfo);
171 	aprint_normal("%s", device_xname(sc->sc_dev));
172 
173 	if (pci_mapreg_map(pa, IO_MAP_REG, PCI_MAPREG_TYPE_IO, 0,
174 	    &iot, &ioh, NULL, NULL)) {
175 		aprint_error(": unable to map registers\n");
176 		return;
177 	}
178 
179 	sc->sc_glue = &pcscp_glue;
180 
181 	esc->sc_st = iot;
182 	esc->sc_sh = ioh;
183 	esc->sc_dmat = pa->pa_dmat;
184 
185 	csr = pci_conf_read(pa->pa_pc, pa->pa_tag, PCI_COMMAND_STATUS_REG);
186 	pci_conf_write(pa->pa_pc, pa->pa_tag, PCI_COMMAND_STATUS_REG,
187 	    csr | PCI_COMMAND_MASTER_ENABLE | PCI_COMMAND_IO_ENABLE);
188 
189 	/*
190 	 * XXX More of this should be in ncr53c9x_attach(), but
191 	 * XXX should we really poke around the chip that much in
192 	 * XXX the MI code?  Think about this more...
193 	 */
194 
195 	/*
196 	 * Set up static configuration info.
197 	 */
198 
199 	/*
200 	 * XXX should read configuration from EEPROM?
201 	 *
202 	 * MI ncr53c9x driver does not support configuration
203 	 * per each target device, though...
204 	 */
205 	sc->sc_id = 7;
206 	sc->sc_cfg1 = sc->sc_id | NCRCFG1_PARENB;
207 	sc->sc_cfg2 = NCRCFG2_SCSI2 | NCRCFG2_FE;
208 	sc->sc_cfg3 = NCRAMDCFG3_IDM | NCRAMDCFG3_FCLK;
209 	sc->sc_cfg4 = NCRAMDCFG4_GE12NS | NCRAMDCFG4_RADE;
210 	sc->sc_rev = NCR_VARIANT_AM53C974;
211 	sc->sc_features = NCR_F_FASTSCSI;
212 	sc->sc_cfg3_fscsi = NCRAMDCFG3_FSCSI;
213 	sc->sc_freq = 40; /* MHz */
214 
215 	/*
216 	 * XXX minsync and maxxfer _should_ be set up in MI code,
217 	 * XXX but it appears to have some dependency on what sort
218 	 * XXX of DMA we're hooked up to, etc.
219 	 */
220 
221 	/*
222 	 * This is the value used to start sync negotiations
223 	 * Note that the NCR register "SYNCTP" is programmed
224 	 * in "clocks per byte", and has a minimum value of 4.
225 	 * The SCSI period used in negotiation is one-fourth
226 	 * of the time (in nanoseconds) needed to transfer one byte.
227 	 * Since the chip's clock is given in MHz, we have the following
228 	 * formula: 4 * period = (1000 / freq) * 4
229 	 */
230 
231 	sc->sc_minsync = 1000 / sc->sc_freq;
232 
233 	/* Really no limit, but since we want to fit into the TCR... */
234 	sc->sc_maxxfer = 16 * 1024 * 1024;
235 
236 	/*
237 	 * Create the DMA maps for the data transfers.
238 	 */
239 
240 #define MDL_SEG_SIZE	0x1000 /* 4kbyte per segment */
241 #define MDL_SEG_OFFSET	0x0FFF
242 #define MDL_SIZE	(MAXPHYS / MDL_SEG_SIZE + 1) /* no hardware limit? */
243 
244 	if (bus_dmamap_create(esc->sc_dmat, MAXPHYS, MDL_SIZE, MDL_SEG_SIZE,
245 	    MDL_SEG_SIZE, BUS_DMA_NOWAIT, &esc->sc_xfermap)) {
246 		aprint_error(": can't create DMA maps\n");
247 		return;
248 	}
249 
250 	/*
251 	 * Allocate and map memory for the MDL.
252 	 */
253 
254 	if ((error = bus_dmamem_alloc(esc->sc_dmat,
255 	    sizeof(uint32_t) * MDL_SIZE, PAGE_SIZE, 0, &seg, 1, &rseg,
256 	    BUS_DMA_NOWAIT)) != 0) {
257 		aprint_error(": unable to allocate memory for the MDL,"
258 		    " error = %d\n", error);
259 		goto fail_0;
260 	}
261 	if ((error = bus_dmamem_map(esc->sc_dmat, &seg, rseg,
262 	    sizeof(uint32_t) * MDL_SIZE , (void **)&esc->sc_mdladdr,
263 	    BUS_DMA_NOWAIT|BUS_DMA_COHERENT)) != 0) {
264 		aprint_error(": unable to map the MDL memory, error = %d\n",
265 		    error);
266 		goto fail_1;
267 	}
268 	if ((error = bus_dmamap_create(esc->sc_dmat,
269 	    sizeof(uint32_t) * MDL_SIZE, 1, sizeof(uint32_t) * MDL_SIZE,
270 	    0, BUS_DMA_NOWAIT, &esc->sc_mdldmap)) != 0) {
271 		aprint_error(": unable to map_create for the MDL, error = %d\n",
272 		    error);
273 		goto fail_2;
274 	}
275 	if ((error = bus_dmamap_load(esc->sc_dmat, esc->sc_mdldmap,
276 	     esc->sc_mdladdr, sizeof(uint32_t) * MDL_SIZE,
277 	     NULL, BUS_DMA_NOWAIT)) != 0) {
278 		aprint_error(": unable to load for the MDL, error = %d\n",
279 		    error);
280 		goto fail_3;
281 	}
282 
283 	/* map and establish interrupt */
284 	if (pci_intr_map(pa, &ih)) {
285 		aprint_error(": couldn't map interrupt\n");
286 		goto fail_4;
287 	}
288 
289 	intrstr = pci_intr_string(pa->pa_pc, ih);
290 	esc->sc_ih = pci_intr_establish(pa->pa_pc, ih, IPL_BIO,
291 	    ncr53c9x_intr, esc);
292 	if (esc->sc_ih == NULL) {
293 		aprint_error(": couldn't establish interrupt");
294 		if (intrstr != NULL)
295 			aprint_error(" at %s", intrstr);
296 		aprint_error("\n");
297 		goto fail_4;
298 	}
299 	if (intrstr != NULL) {
300 		aprint_normal(": interrupting at %s\n", intrstr);
301 		aprint_normal("%s", device_xname(sc->sc_dev));
302 	}
303 
304 	/* Do the common parts of attachment. */
305 	sc->sc_adapter.adapt_minphys = minphys;
306 	sc->sc_adapter.adapt_request = ncr53c9x_scsipi_request;
307 	ncr53c9x_attach(sc);
308 
309 	/* Turn on target selection using the `DMA' method */
310 	sc->sc_features |= NCR_F_DMASELECT;
311 
312 	return;
313 
314  fail_4:
315 	bus_dmamap_unload(esc->sc_dmat, esc->sc_mdldmap);
316  fail_3:
317 	bus_dmamap_destroy(esc->sc_dmat, esc->sc_mdldmap);
318  fail_2:
319 	bus_dmamem_unmap(esc->sc_dmat, (void *)esc->sc_mdldmap,
320 	    sizeof(uint32_t) * MDL_SIZE);
321  fail_1:
322 	bus_dmamem_free(esc->sc_dmat, &seg, rseg);
323  fail_0:
324 	bus_dmamap_destroy(esc->sc_dmat, esc->sc_xfermap);
325 }
326 
327 /*
328  * Glue functions.
329  */
330 
331 static uint8_t
332 pcscp_read_reg(struct ncr53c9x_softc *sc, int reg)
333 {
334 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
335 
336 	return PCSCP_READ_REG(esc, reg);
337 }
338 
339 static void
340 pcscp_write_reg(struct ncr53c9x_softc *sc, int reg, uint8_t v)
341 {
342 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
343 
344 	PCSCP_WRITE_REG(esc, reg, v);
345 }
346 
347 static int
348 pcscp_dma_isintr(struct ncr53c9x_softc *sc)
349 {
350 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
351 
352 	return (PCSCP_READ_REG(esc, NCR_STAT) & NCRSTAT_INT) != 0;
353 }
354 
355 static void
356 pcscp_dma_reset(struct ncr53c9x_softc *sc)
357 {
358 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
359 
360 	WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE);
361 
362 	esc->sc_active = 0;
363 }
364 
365 static int
366 pcscp_dma_intr(struct ncr53c9x_softc *sc)
367 {
368 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
369 	int trans, resid, i;
370 	bus_dmamap_t dmap = esc->sc_xfermap;
371 	int datain = esc->sc_datain;
372 	uint32_t dmastat;
373 	uint8_t *p = NULL;
374 
375 	dmastat = READ_DMAREG(esc, DMA_STAT);
376 
377 	if (dmastat & DMASTAT_ERR) {
378 		/* XXX not tested... */
379 		WRITE_DMAREG(esc, DMA_CMD,
380 		    DMACMD_ABORT | (datain ? DMACMD_DIR : 0));
381 
382 		printf("%s: error: DMA error detected; Aborting.\n",
383 		    device_xname(sc->sc_dev));
384 		bus_dmamap_unload(esc->sc_dmat, dmap);
385 		return -1;
386 	}
387 
388 	if (dmastat & DMASTAT_ABT) {
389 		/* XXX What should be done? */
390 		printf("%s: %s: DMA aborted.\n",
391 		    device_xname(sc->sc_dev), __func__);
392 		WRITE_DMAREG(esc, DMA_CMD,
393 		    DMACMD_IDLE | (datain ? DMACMD_DIR : 0));
394 		esc->sc_active = 0;
395 		return 0;
396 	}
397 
398 #ifdef DIAGNOSTIC
399 	/* This is an "assertion" :) */
400 	if (esc->sc_active == 0)
401 		panic("%s: %s: DMA wasn't active",
402 		    device_xname(sc->sc_dev), __func__);
403 #endif
404 
405 	/* DMA has stopped */
406 
407 	esc->sc_active = 0;
408 
409 	if (esc->sc_dmasize == 0) {
410 		/* A "Transfer Pad" operation completed */
411 		NCR_DMA(("%s: discarded %d bytes (tcl=%d, tcm=%d)\n",
412 		    __func__,
413 		    PCSCP_READ_REG(esc, NCR_TCL) |
414 		    (PCSCP_READ_REG(esc, NCR_TCM) << 8),
415 		    PCSCP_READ_REG(esc, NCR_TCL),
416 		    PCSCP_READ_REG(esc, NCR_TCM)));
417 		return 0;
418 	}
419 
420 	resid = 0;
421 	/*
422 	 * If a transfer onto the SCSI bus gets interrupted by the device
423 	 * (e.g. for a SAVEPOINTER message), the data in the FIFO counts
424 	 * as residual since the ESP counter registers get decremented as
425 	 * bytes are clocked into the FIFO.
426 	 */
427 	if (!datain &&
428 	    (resid = (PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF)) != 0) {
429 		NCR_DMA(("%s: empty esp FIFO of %d ", __func__, resid));
430 	}
431 
432 	if ((sc->sc_espstat & NCRSTAT_TC) == 0) {
433 		/*
434 		 * `Terminal count' is off, so read the residue
435 		 * out of the ESP counter registers.
436 		 */
437 		if (datain) {
438 			resid = PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF;
439 			while (resid > 1)
440 				resid =
441 				    PCSCP_READ_REG(esc, NCR_FFLAG) & NCRFIFO_FF;
442 			WRITE_DMAREG(esc, DMA_CMD, DMACMD_BLAST | DMACMD_MDL |
443 			    (datain ? DMACMD_DIR : 0));
444 
445 			for (i = 0; i < 1000; i++) { /* XXX */
446 				if (READ_DMAREG(esc, DMA_STAT) & DMASTAT_BCMP)
447 					break;
448 				DELAY(1);
449 			}
450 
451 			/* See the below comments... */
452 			if (resid)
453 				p = *esc->sc_dmaaddr;
454 		}
455 
456 		resid += PCSCP_READ_REG(esc, NCR_TCL) |
457 		    (PCSCP_READ_REG(esc, NCR_TCM) << 8) |
458 		    (PCSCP_READ_REG(esc, NCR_TCH) << 16);
459 	} else {
460 		while ((dmastat & DMASTAT_DONE) == 0)
461 			dmastat = READ_DMAREG(esc, DMA_STAT);
462 	}
463 
464 	WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | (datain ? DMACMD_DIR : 0));
465 
466 	/* sync MDL */
467 	bus_dmamap_sync(esc->sc_dmat, esc->sc_mdldmap,
468 	    0, sizeof(uint32_t) * dmap->dm_nsegs, BUS_DMASYNC_POSTWRITE);
469 	/* sync transfer buffer */
470 	bus_dmamap_sync(esc->sc_dmat, dmap, 0, dmap->dm_mapsize,
471 	    datain ? BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);
472 	bus_dmamap_unload(esc->sc_dmat, dmap);
473 
474 	trans = esc->sc_dmasize - resid;
475 
476 	/*
477 	 * From the technical manual notes:
478 	 *
479 	 * `In some odd byte conditions, one residual byte will be left
480 	 *  in the SCSI FIFO, and the FIFO flags will never count to 0.
481 	 *  When this happens, the residual byte should be retrieved
482 	 *  via PIO following completion of the BLAST operation.'
483 	 */
484 
485 	if (p) {
486 		p += trans;
487 		*p = PCSCP_READ_REG(esc, NCR_FIFO);
488 		trans++;
489 	}
490 
491 	if (trans < 0) {			/* transferred < 0 ? */
492 #if 0
493 		/*
494 		 * This situation can happen in perfectly normal operation
495 		 * if the ESP is reselected while using DMA to select
496 		 * another target.  As such, don't print the warning.
497 		 */
498 		printf("%s: xfer (%d) > req (%d)\n",
499 		    device_xname(sc->sc_dev), trans, esc->sc_dmasize);
500 #endif
501 		trans = esc->sc_dmasize;
502 	}
503 
504 	NCR_DMA(("%s: tcl=%d, tcm=%d, tch=%d; trans=%d, resid=%d\n",
505 	    __func__,
506 	    PCSCP_READ_REG(esc, NCR_TCL),
507 	    PCSCP_READ_REG(esc, NCR_TCM),
508 	    PCSCP_READ_REG(esc, NCR_TCH),
509 	    trans, resid));
510 
511 	*esc->sc_dmalen -= trans;
512 	*esc->sc_dmaaddr += trans;
513 
514 	return 0;
515 }
516 
517 static int
518 pcscp_dma_setup(struct ncr53c9x_softc *sc, uint8_t **addr, size_t *len,
519     int datain, size_t *dmasize)
520 {
521 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
522 	bus_dmamap_t dmap = esc->sc_xfermap;
523 	uint32_t *mdl;
524 	int error, nseg, seg;
525 	bus_addr_t s_offset, s_addr;
526 
527 	WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | (datain ? DMACMD_DIR : 0));
528 
529 	esc->sc_dmaaddr = addr;
530 	esc->sc_dmalen = len;
531 	esc->sc_dmasize = *dmasize;
532 	esc->sc_datain = datain;
533 
534 #ifdef DIAGNOSTIC
535 	if ((*dmasize / MDL_SEG_SIZE) > MDL_SIZE)
536 		panic("%s: transfer size too large", device_xname(sc->sc_dev));
537 #endif
538 
539 	/*
540 	 * No need to set up DMA in `Transfer Pad' operation.
541 	 * (case of *dmasize == 0)
542 	 */
543 	if (*dmasize == 0)
544 		return 0;
545 
546 	error = bus_dmamap_load(esc->sc_dmat, dmap, *esc->sc_dmaaddr,
547 	    *esc->sc_dmalen, NULL,
548 	    ((sc->sc_nexus->xs->xs_control & XS_CTL_NOSLEEP) ?
549 	    BUS_DMA_NOWAIT : BUS_DMA_WAITOK) | BUS_DMA_STREAMING |
550 	    ((sc->sc_nexus->xs->xs_control & XS_CTL_DATA_IN) ?
551 	     BUS_DMA_READ : BUS_DMA_WRITE));
552 	if (error) {
553 		printf("%s: unable to load dmamap, error = %d\n",
554 		    device_xname(sc->sc_dev), error);
555 		return error;
556 	}
557 
558 	/* set transfer length */
559 	WRITE_DMAREG(esc, DMA_STC, *dmasize);
560 
561 	/* set up MDL */
562 	mdl = esc->sc_mdladdr;
563 	nseg = dmap->dm_nsegs;
564 
565 	/* the first segment is possibly not aligned with 4k MDL boundary */
566 	s_addr = dmap->dm_segs[0].ds_addr;
567 	s_offset = s_addr & MDL_SEG_OFFSET;
568 	s_addr -= s_offset;
569 
570 	/* set the first MDL and offset */
571 	WRITE_DMAREG(esc, DMA_SPA, s_offset);
572 	*mdl++ = htole32(s_addr);
573 
574 	/* the rest dmamap segments are aligned with 4k boundary */
575 	for (seg = 1; seg < nseg; seg++)
576 		*mdl++ = htole32(dmap->dm_segs[seg].ds_addr);
577 
578 	return 0;
579 }
580 
581 static void
582 pcscp_dma_go(struct ncr53c9x_softc *sc)
583 {
584 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
585 	bus_dmamap_t dmap = esc->sc_xfermap, mdldmap = esc->sc_mdldmap;
586 	int datain = esc->sc_datain;
587 
588 	/* No DMA transfer in Transfer Pad operation */
589 	if (esc->sc_dmasize == 0)
590 		return;
591 
592 	/* sync transfer buffer */
593 	bus_dmamap_sync(esc->sc_dmat, dmap, 0, dmap->dm_mapsize,
594 	    datain ? BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
595 
596 	/* sync MDL */
597 	bus_dmamap_sync(esc->sc_dmat, mdldmap,
598 	    0, sizeof(uint32_t) * dmap->dm_nsegs, BUS_DMASYNC_PREWRITE);
599 
600 	/* set Starting MDL Address */
601 	WRITE_DMAREG(esc, DMA_SMDLA, mdldmap->dm_segs[0].ds_addr);
602 
603 	/* set DMA command register bits */
604 	/* XXX DMA Transfer Interrupt Enable bit is broken? */
605 	WRITE_DMAREG(esc, DMA_CMD, DMACMD_IDLE | DMACMD_MDL |
606 	    /* DMACMD_INTE | */
607 	    (datain ? DMACMD_DIR : 0));
608 
609 	/* issue DMA start command */
610 	WRITE_DMAREG(esc, DMA_CMD, DMACMD_START | DMACMD_MDL |
611 	    /* DMACMD_INTE | */
612 	    (datain ? DMACMD_DIR : 0));
613 
614 	esc->sc_active = 1;
615 }
616 
617 static void
618 pcscp_dma_stop(struct ncr53c9x_softc *sc)
619 {
620 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
621 
622 	/* DMA stop */
623 	/* XXX What should we do here ? */
624 	WRITE_DMAREG(esc, DMA_CMD,
625 	    DMACMD_ABORT | (esc->sc_datain ? DMACMD_DIR : 0));
626 	bus_dmamap_unload(esc->sc_dmat, esc->sc_xfermap);
627 
628 	esc->sc_active = 0;
629 }
630 
631 static int
632 pcscp_dma_isactive(struct ncr53c9x_softc *sc)
633 {
634 	struct pcscp_softc *esc = (struct pcscp_softc *)sc;
635 
636 	/* XXX should check esc->sc_active? */
637 	if ((READ_DMAREG(esc, DMA_CMD) & DMACMD_CMD) != DMACMD_IDLE)
638 		return 1;
639 	return 0;
640 }
641