xref: /netbsd-src/sys/dev/ata/ata_wdc.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: ata_wdc.c,v 1.110 2018/06/01 18:13:30 macallan Exp $	*/
2 
3 /*
4  * Copyright (c) 1998, 2001, 2003 Manuel Bouyer.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /*-
28  * Copyright (c) 1998, 2004 The NetBSD Foundation, Inc.
29  * All rights reserved.
30  *
31  * This code is derived from software contributed to The NetBSD Foundation
32  * by Charles M. Hannum, by Onno van der Linden and by Manuel Bouyer.
33  *
34  * Redistribution and use in source and binary forms, with or without
35  * modification, are permitted provided that the following conditions
36  * are met:
37  * 1. Redistributions of source code must retain the above copyright
38  *    notice, this list of conditions and the following disclaimer.
39  * 2. Redistributions in binary form must reproduce the above copyright
40  *    notice, this list of conditions and the following disclaimer in the
41  *    documentation and/or other materials provided with the distribution.
42  *
43  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
44  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
45  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
46  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
47  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
48  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
49  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
50  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
51  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
52  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
53  * POSSIBILITY OF SUCH DAMAGE.
54  */
55 
56 #include <sys/cdefs.h>
57 __KERNEL_RCSID(0, "$NetBSD: ata_wdc.c,v 1.110 2018/06/01 18:13:30 macallan Exp $");
58 
59 #include "opt_ata.h"
60 #include "opt_wdc.h"
61 
62 #include <sys/param.h>
63 #include <sys/systm.h>
64 #include <sys/kernel.h>
65 #include <sys/file.h>
66 #include <sys/stat.h>
67 #include <sys/buf.h>
68 #include <sys/bufq.h>
69 #include <sys/malloc.h>
70 #include <sys/device.h>
71 #include <sys/disklabel.h>
72 #include <sys/syslog.h>
73 #include <sys/proc.h>
74 
75 #include <sys/intr.h>
76 #include <sys/bus.h>
77 #ifndef __BUS_SPACE_HAS_STREAM_METHODS
78 #define    bus_space_write_multi_stream_2    bus_space_write_multi_2
79 #define    bus_space_write_multi_stream_4    bus_space_write_multi_4
80 #define    bus_space_read_multi_stream_2    bus_space_read_multi_2
81 #define    bus_space_read_multi_stream_4    bus_space_read_multi_4
82 #endif /* __BUS_SPACE_HAS_STREAM_METHODS */
83 
84 #include <dev/ata/ataconf.h>
85 #include <dev/ata/atareg.h>
86 #include <dev/ata/atavar.h>
87 #include <dev/ic/wdcreg.h>
88 #include <dev/ic/wdcvar.h>
89 
90 #define DEBUG_INTR   0x01
91 #define DEBUG_XFERS  0x02
92 #define DEBUG_STATUS 0x04
93 #define DEBUG_FUNCS  0x08
94 #define DEBUG_PROBE  0x10
95 #ifdef ATADEBUG
96 extern int wdcdebug_wd_mask; /* inited in wd.c */
97 #define ATADEBUG_PRINT(args, level) \
98 	if (wdcdebug_wd_mask & (level)) \
99 		printf args
100 #else
101 #define ATADEBUG_PRINT(args, level)
102 #endif
103 
104 #define ATA_DELAY 10000 /* 10s for a drive I/O */
105 
106 static int	wdc_ata_bio(struct ata_drive_datas*, struct ata_xfer *);
107 static int	wdc_ata_bio_start(struct ata_channel *,struct ata_xfer *);
108 static int	_wdc_ata_bio_start(struct ata_channel *,struct ata_xfer *);
109 static void	wdc_ata_bio_poll(struct ata_channel *,struct ata_xfer *);
110 static int	wdc_ata_bio_intr(struct ata_channel *, struct ata_xfer *,
111 				 int);
112 static void	wdc_ata_bio_kill_xfer(struct ata_channel *,
113 				      struct ata_xfer *, int);
114 static void	wdc_ata_bio_done(struct ata_channel *, struct ata_xfer *);
115 static int	wdc_ata_err(struct ata_drive_datas *, struct ata_bio *, int);
116 #define WDC_ATA_NOERR 0x00 /* Drive doesn't report an error */
117 #define WDC_ATA_RECOV 0x01 /* There was a recovered error */
118 #define WDC_ATA_ERR   0x02 /* Drive reports an error */
119 static int	wdc_ata_addref(struct ata_drive_datas *);
120 static void	wdc_ata_delref(struct ata_drive_datas *);
121 
122 const struct ata_bustype wdc_ata_bustype = {
123 	SCSIPI_BUSTYPE_ATA,
124 	wdc_ata_bio,
125 	wdc_reset_drive,
126 	wdc_reset_channel,
127 	wdc_exec_command,
128 	ata_get_params,
129 	wdc_ata_addref,
130 	wdc_ata_delref,
131 	ata_kill_pending,
132 };
133 
134 /*
135  * Handle block I/O operation. Return ATACMD_COMPLETE, ATACMD_QUEUED, or
136  * ATACMD_TRY_AGAIN. Must be called at splbio().
137  */
138 static int
139 wdc_ata_bio(struct ata_drive_datas *drvp, struct ata_xfer *xfer)
140 {
141 	struct ata_channel *chp = drvp->chnl_softc;
142 	struct atac_softc *atac = chp->ch_atac;
143 	struct ata_bio *ata_bio = &xfer->c_bio;
144 
145 	if (atac->atac_cap & ATAC_CAP_NOIRQ)
146 		ata_bio->flags |= ATA_POLL;
147 	if (ata_bio->flags & ATA_POLL)
148 		xfer->c_flags |= C_POLL;
149 #if NATA_DMA
150 	if ((drvp->drive_flags & (ATA_DRIVE_DMA | ATA_DRIVE_UDMA)) &&
151 	    (ata_bio->flags & ATA_SINGLE) == 0)
152 		xfer->c_flags |= C_DMA;
153 #endif
154 #if NATA_DMA && NATA_PIOBM
155 	else
156 #endif
157 #if NATA_PIOBM
158 	if (atac->atac_cap & ATAC_CAP_PIOBM)
159 		xfer->c_flags |= C_PIOBM;
160 #endif
161 	xfer->c_drive = drvp->drive;
162 	xfer->c_databuf = ata_bio->databuf;
163 	xfer->c_bcount = ata_bio->bcount;
164 	xfer->c_start = wdc_ata_bio_start;
165 	xfer->c_poll = wdc_ata_bio_poll;
166 	xfer->c_abort = wdc_ata_bio_done;
167 	xfer->c_intr = wdc_ata_bio_intr;
168 	xfer->c_kill_xfer = wdc_ata_bio_kill_xfer;
169 	ata_exec_xfer(chp, xfer);
170 	return (ata_bio->flags & ATA_ITSDONE) ? ATACMD_COMPLETE : ATACMD_QUEUED;
171 }
172 
173 static int
174 wdc_ata_bio_start(struct ata_channel *chp, struct ata_xfer *xfer)
175 {
176 	struct atac_softc *atac = chp->ch_atac;
177 	struct wdc_softc *wdc = CHAN_TO_WDC(chp);
178 	struct wdc_regs *wdr = &wdc->regs[chp->ch_channel];
179 	struct ata_bio *ata_bio = &xfer->c_bio;
180 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->c_drive];
181 	int wait_flags, tfd;
182 	const char *errstring;
183 #ifdef WDC_NO_IDS
184 	wait_flags = AT_POLL;
185 #else
186 	wait_flags = (xfer->c_flags & C_POLL) ? AT_POLL : 0;
187 #endif
188 
189 	ATADEBUG_PRINT(("wdc_ata_bio_start %s:%d:%d state %d drive_flags 0x%x "
190 	    "c_flags 0x%x ch_flags 0x%x\n",
191 	    device_xname(atac->atac_dev), chp->ch_channel, xfer->c_drive,
192 	    drvp->state, drvp->drive_flags, xfer->c_flags, chp->ch_flags),
193 	    DEBUG_XFERS);
194 
195 	ata_channel_lock_owned(chp);
196 
197 	/* Do control operations specially. */
198 	if (__predict_false(drvp->state < READY)) {
199 		/*
200 		 * Actually, we want to be careful not to mess with the control
201 		 * state if the device is currently busy, but we can assume
202 		 * that we never get to this point if that's the case.
203 		 */
204 		/* If it's not a polled command, we need the kernel thread */
205 		if ((xfer->c_flags & C_POLL) == 0 &&
206 		    (chp->ch_flags & ATACH_TH_RUN) == 0) {
207 			return ATASTART_TH;
208 		}
209 		/*
210 		 * disable interrupts, all commands here should be quick
211 		 * enough to be able to poll, and we don't go here that often
212 		 */
213 		if (! (wdc->cap & WDC_CAPABILITY_NO_AUXCTL))
214 			bus_space_write_1(wdr->ctl_iot, wdr->ctl_ioh,
215 			    wd_aux_ctlr, WDCTL_4BIT | WDCTL_IDS);
216 		if (wdc->select)
217 			wdc->select(chp, xfer->c_drive);
218 		bus_space_write_1(wdr->cmd_iot, wdr->cmd_iohs[wd_sdh], 0,
219 		    WDSD_IBM | (xfer->c_drive << 4));
220 		DELAY(10);
221 		errstring = "wait";
222 		if (wdcwait(chp, WDCS_DRDY, WDCS_DRDY, ATA_DELAY, wait_flags,
223 		    &tfd))
224 			goto ctrltimeout;
225 		wdccommandshort(chp, xfer->c_drive, WDCC_RECAL);
226 		/* Wait for at last 400ns for status bit to be valid */
227 		DELAY(1);
228 		errstring = "recal";
229 		if (wdcwait(chp, WDCS_DRDY, WDCS_DRDY, ATA_DELAY, wait_flags,
230 		    &tfd))
231 			goto ctrltimeout;
232 		if (ATACH_ST(tfd) & (WDCS_ERR | WDCS_DWF))
233 			goto ctrlerror;
234 		/* Don't try to set modes if controller can't be adjusted */
235 		if (atac->atac_set_modes == NULL)
236 			goto geometry;
237 		/* Also don't try if the drive didn't report its mode */
238 		if ((drvp->drive_flags & ATA_DRIVE_MODE) == 0)
239 			goto geometry;
240 		wdccommand(chp, drvp->drive, SET_FEATURES, 0, 0, 0,
241 		    0x08 | drvp->PIO_mode, WDSF_SET_MODE);
242 		errstring = "piomode";
243 		if (wdcwait(chp, WDCS_DRDY, WDCS_DRDY, ATA_DELAY, wait_flags,
244 		    &tfd))
245 			goto ctrltimeout;
246 		if (ATACH_ST(tfd) & (WDCS_ERR | WDCS_DWF))
247 			goto ctrlerror;
248 #if NATA_DMA
249 #if NATA_UDMA
250 		if (drvp->drive_flags & ATA_DRIVE_UDMA) {
251 			wdccommand(chp, drvp->drive, SET_FEATURES, 0, 0, 0,
252 			    0x40 | drvp->UDMA_mode, WDSF_SET_MODE);
253 		} else
254 #endif
255 		if (drvp->drive_flags & ATA_DRIVE_DMA) {
256 			wdccommand(chp, drvp->drive, SET_FEATURES, 0, 0, 0,
257 			    0x20 | drvp->DMA_mode, WDSF_SET_MODE);
258 		} else {
259 			goto geometry;
260 		}
261 		errstring = "dmamode";
262 		if (wdcwait(chp, WDCS_DRDY, WDCS_DRDY, ATA_DELAY, wait_flags,
263 		    &tfd))
264 			goto ctrltimeout;
265 		if (ATACH_ST(tfd) & (WDCS_ERR | WDCS_DWF))
266 			goto ctrlerror;
267 #endif	/* NATA_DMA */
268 geometry:
269 		if (ata_bio->flags & ATA_LBA)
270 			goto multimode;
271 		wdccommand(chp, xfer->c_drive, WDCC_IDP,
272 		    drvp->lp->d_ncylinders,
273 		    drvp->lp->d_ntracks - 1, 0, drvp->lp->d_nsectors,
274 		    (drvp->lp->d_type == DKTYPE_ST506) ?
275 			drvp->lp->d_precompcyl / 4 : 0);
276 		errstring = "geometry";
277 		if (wdcwait(chp, WDCS_DRDY, WDCS_DRDY, ATA_DELAY, wait_flags,
278 		    &tfd))
279 			goto ctrltimeout;
280 		if (ATACH_ST(tfd) & (WDCS_ERR | WDCS_DWF))
281 			goto ctrlerror;
282 multimode:
283 		if (drvp->multi == 1)
284 			goto ready;
285 		wdccommand(chp, xfer->c_drive, WDCC_SETMULTI, 0, 0, 0,
286 		    drvp->multi, 0);
287 		errstring = "setmulti";
288 		if (wdcwait(chp, WDCS_DRDY, WDCS_DRDY, ATA_DELAY, wait_flags,
289 		    &tfd))
290 			goto ctrltimeout;
291 		if (ATACH_ST(tfd) & (WDCS_ERR | WDCS_DWF))
292 			goto ctrlerror;
293 ready:
294 		drvp->state = READY;
295 		/*
296 		 * The drive is usable now
297 		 */
298 		if (! (wdc->cap & WDC_CAPABILITY_NO_AUXCTL))
299 			bus_space_write_1(wdr->ctl_iot, wdr->ctl_ioh,
300 			    wd_aux_ctlr, WDCTL_4BIT);
301 		delay(10); /* some drives need a little delay here */
302 	}
303 
304 	return _wdc_ata_bio_start(chp, xfer);
305 ctrltimeout:
306 	printf("%s:%d:%d: %s timed out\n",
307 	    device_xname(atac->atac_dev), chp->ch_channel, xfer->c_drive,
308 	    errstring);
309 	ata_bio->error = TIMEOUT;
310 	goto ctrldone;
311 ctrlerror:
312 	printf("%s:%d:%d: %s ",
313 	    device_xname(atac->atac_dev), chp->ch_channel, xfer->c_drive,
314 	    errstring);
315 	if (ATACH_ST(tfd) & WDCS_DWF) {
316 		printf("drive fault\n");
317 		ata_bio->error = ERR_DF;
318 	} else {
319 		ata_bio->r_error = ATACH_ERR(tfd);
320 		ata_bio->error = ERROR;
321 		printf("error (%x)\n", ata_bio->r_error);
322 	}
323 ctrldone:
324 	drvp->state = 0;
325 
326 	if (! (wdc->cap & WDC_CAPABILITY_NO_AUXCTL))
327 		bus_space_write_1(wdr->ctl_iot, wdr->ctl_ioh, wd_aux_ctlr,
328 		    WDCTL_4BIT);
329 	return ATASTART_ABORT;
330 }
331 
332 static int
333 _wdc_ata_bio_start(struct ata_channel *chp, struct ata_xfer *xfer)
334 {
335 	struct atac_softc *atac = chp->ch_atac;
336 	struct wdc_softc *wdc = CHAN_TO_WDC(chp);
337 	struct wdc_regs *wdr = &wdc->regs[chp->ch_channel];
338 	struct ata_bio *ata_bio = &xfer->c_bio;
339 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->c_drive];
340 	int wait_flags = (xfer->c_flags & C_POLL) ? AT_POLL : 0;
341 	uint16_t cyl;
342 	uint8_t head, sect, cmd = 0;
343 	int nblks, tfd;
344 #if NATA_DMA || NATA_PIOBM
345 	int error, dma_flags = 0;
346 #endif
347 
348 	ATADEBUG_PRINT(("_wdc_ata_bio_start %s:%d:%d\n",
349 	    device_xname(atac->atac_dev), chp->ch_channel, xfer->c_drive),
350 	    DEBUG_INTR | DEBUG_XFERS);
351 
352 #if NATA_DMA || NATA_PIOBM
353 	if (xfer->c_flags & (C_DMA | C_PIOBM)) {
354 #if NATA_DMA
355 		if (drvp->n_xfers <= NXFER)
356 			drvp->n_xfers++;
357 #endif
358 		dma_flags = (ata_bio->flags & ATA_READ) ?  WDC_DMA_READ : 0;
359 		if (ata_bio->flags & ATA_LBA48)
360 			dma_flags |= WDC_DMA_LBA48;
361 	}
362 #endif
363 	/*
364 	 *
365 	 * When starting a multi-sector transfer, or doing single-sector
366 	 * transfers...
367 	 */
368 	if (xfer->c_skip == 0 || (ata_bio->flags & ATA_SINGLE) != 0) {
369 		if (ata_bio->flags & ATA_SINGLE)
370 			nblks = 1;
371 		else
372 			nblks = xfer->c_bcount / drvp->lp->d_secsize;
373 		/* Check for bad sectors and adjust transfer, if necessary. */
374 		if ((drvp->lp->d_flags & D_BADSECT) != 0) {
375 			long blkdiff;
376 			int i;
377 			for (i = 0; (blkdiff = drvp->badsect[i]) != -1;
378 			    i++) {
379 				blkdiff -= ata_bio->blkno;
380 				if (blkdiff < 0)
381 					continue;
382 				if (blkdiff == 0) {
383 					/* Replace current block of transfer. */
384 					ata_bio->blkno =
385 					    drvp->lp->d_secperunit -
386 					    drvp->lp->d_nsectors - i - 1;
387 				}
388 				if (blkdiff < nblks) {
389 					/* Bad block inside transfer. */
390 					ata_bio->flags |= ATA_SINGLE;
391 					nblks = 1;
392 				}
393 				break;
394 			}
395 		/* Transfer is okay now. */
396 		}
397 		if (ata_bio->flags & ATA_LBA48) {
398 			sect = 0;
399 			cyl =  0;
400 			head = 0;
401 		} else if (ata_bio->flags & ATA_LBA) {
402 			sect = (ata_bio->blkno >> 0) & 0xff;
403 			cyl = (ata_bio->blkno >> 8) & 0xffff;
404 			head = (ata_bio->blkno >> 24) & 0x0f;
405 			head |= WDSD_LBA;
406 		} else {
407 			int blkno = ata_bio->blkno;
408 			sect = blkno % drvp->lp->d_nsectors;
409 			sect++;    /* Sectors begin with 1, not 0. */
410 			blkno /= drvp->lp->d_nsectors;
411 			head = blkno % drvp->lp->d_ntracks;
412 			blkno /= drvp->lp->d_ntracks;
413 			cyl = blkno;
414 			head |= WDSD_CHS;
415 		}
416 #if NATA_DMA
417 		if (xfer->c_flags & C_DMA) {
418 			uint16_t count = nblks, features = 0;
419 
420 			ata_bio->nblks = nblks;
421 			ata_bio->nbytes = xfer->c_bcount;
422 			cmd = (ata_bio->flags & ATA_READ) ?
423 			    WDCC_READDMA : WDCC_WRITEDMA;
424 	    		/* Init the DMA channel. */
425 			error = (*wdc->dma_init)(wdc->dma_arg,
426 			    chp->ch_channel, xfer->c_drive,
427 			    (char *)xfer->c_databuf + xfer->c_skip,
428 			    ata_bio->nbytes, dma_flags);
429 			if (error) {
430 				if (error == EINVAL) {
431 					/*
432 					 * We can't do DMA on this transfer
433 					 * for some reason.  Fall back to
434 					 * PIO.
435 					 */
436 					xfer->c_flags &= ~C_DMA;
437 					error = 0;
438 					goto do_pio;
439 				}
440 				ata_bio->error = ERR_DMA;
441 				ata_bio->r_error = 0;
442 				return ATASTART_ABORT;
443 			}
444 			/* Initiate command */
445 			if (wdc->select)
446 				wdc->select(chp, xfer->c_drive);
447 			bus_space_write_1(wdr->cmd_iot, wdr->cmd_iohs[wd_sdh],
448 			    0, WDSD_IBM | (xfer->c_drive << 4));
449 			switch(wdc_wait_for_ready(chp, ATA_DELAY, wait_flags,
450 			    &tfd)) {
451 			case WDCWAIT_OK:
452 				break;
453 			case WDCWAIT_TOUT:
454 				goto timeout;
455 			case WDCWAIT_THR:
456 				return ATASTART_TH;
457 			}
458 			/* start the DMA channel before */
459 			if ((chp->ch_flags & ATACH_DMA_BEFORE_CMD) != 0)
460 				(*wdc->dma_start)(wdc->dma_arg,
461 				    chp->ch_channel, xfer->c_drive);
462 			if (ata_bio->flags & ATA_LBA48) {
463 			    uint8_t device = WDSD_LBA;
464 			    cmd = atacmd_to48(cmd);
465 
466 			    atacmd_toncq(xfer, &cmd, &count, &features,
467 			        &device);
468 
469 			    wdccommandext(chp, xfer->c_drive, cmd,
470 				ata_bio->blkno, count, features, device);
471 			} else {
472 			    wdccommand(chp, xfer->c_drive, cmd, cyl,
473 				head, sect, count, features);
474 			}
475 			/* start the DMA channel after */
476 			if ((chp->ch_flags & ATACH_DMA_BEFORE_CMD) == 0)
477 				(*wdc->dma_start)(wdc->dma_arg,
478 				    chp->ch_channel, xfer->c_drive);
479 			chp->ch_flags |= ATACH_DMA_WAIT;
480 			/* start timeout machinery */
481 			if ((xfer->c_flags & C_POLL) == 0)
482 				callout_reset(&xfer->c_timo_callout,
483 				    ATA_DELAY / 1000 * hz, wdctimeout, xfer);
484 			/* wait for irq */
485 			goto intr;
486 		} /* else not DMA */
487  do_pio:
488 #endif	/* NATA_DMA */
489 #if NATA_PIOBM
490 		if ((xfer->c_flags & C_PIOBM) && xfer->c_skip == 0) {
491 			if (ata_bio->flags & ATA_POLL) {
492 				/* XXX not supported yet --- fall back to PIO */
493 				xfer->c_flags &= ~C_PIOBM;
494 			} else {
495 				/* Init the DMA channel. */
496 				error = (*wdc->dma_init)(wdc->dma_arg,
497 				    chp->ch_channel, xfer->c_drive,
498 				    (char *)xfer->c_databuf + xfer->c_skip,
499 				    xfer->c_bcount,
500 				    dma_flags | WDC_DMA_PIOBM_ATA);
501 				if (error) {
502 					if (error == EINVAL) {
503 						/*
504 						 * We can't do DMA on this
505 						 * transfer for some reason.
506 						 * Fall back to PIO.
507 						 */
508 						xfer->c_flags &= ~C_PIOBM;
509 						error = 0;
510 					} else {
511 						ata_bio->error = ERR_DMA;
512 						ata_bio->r_error = 0;
513 						return ATASTART_ABORT;
514 					}
515 				}
516 			}
517 		}
518 #endif
519 		ata_bio->nblks = min(nblks, drvp->multi);
520 		ata_bio->nbytes = ata_bio->nblks * drvp->lp->d_secsize;
521 		KASSERT(nblks == 1 || (ata_bio->flags & ATA_SINGLE) == 0);
522 		if (ata_bio->nblks > 1) {
523 			cmd = (ata_bio->flags & ATA_READ) ?
524 			    WDCC_READMULTI : WDCC_WRITEMULTI;
525 		} else {
526 			cmd = (ata_bio->flags & ATA_READ) ?
527 			    WDCC_READ : WDCC_WRITE;
528 		}
529 		/* Initiate command! */
530 		if (wdc->select)
531 			wdc->select(chp, xfer->c_drive);
532 		bus_space_write_1(wdr->cmd_iot, wdr->cmd_iohs[wd_sdh], 0,
533 		    WDSD_IBM | (xfer->c_drive << 4));
534 		switch(wdc_wait_for_ready(chp, ATA_DELAY, wait_flags, &tfd)) {
535 		case WDCWAIT_OK:
536 			break;
537 		case WDCWAIT_TOUT:
538 			goto timeout;
539 		case WDCWAIT_THR:
540 			return ATASTART_TH;
541 		}
542 		if (ata_bio->flags & ATA_LBA48) {
543 		    wdccommandext(chp, xfer->c_drive, atacmd_to48(cmd),
544 			ata_bio->blkno, nblks, 0, WDSD_LBA);
545 		} else {
546 		    wdccommand(chp, xfer->c_drive, cmd, cyl,
547 			head, sect, nblks,
548 			(drvp->lp->d_type == DKTYPE_ST506) ?
549 			drvp->lp->d_precompcyl / 4 : 0);
550 		}
551 		/* start timeout machinery */
552 		if ((xfer->c_flags & C_POLL) == 0)
553 			callout_reset(&xfer->c_timo_callout,
554 			    ATA_DELAY / 1000 * hz, wdctimeout, xfer);
555 	} else if (ata_bio->nblks > 1) {
556 		/* The number of blocks in the last stretch may be smaller. */
557 		nblks = xfer->c_bcount / drvp->lp->d_secsize;
558 		if (ata_bio->nblks > nblks) {
559 		ata_bio->nblks = nblks;
560 		ata_bio->nbytes = xfer->c_bcount;
561 		}
562 	}
563 	/* If this was a write and not using DMA, push the data. */
564 	if ((ata_bio->flags & ATA_READ) == 0) {
565 		/*
566 		 * we have to busy-wait here, we can't rely on running in
567 		 * thread context.
568 		 */
569 		if (wdc_wait_for_drq(chp, ATA_DELAY, AT_POLL, &tfd) != 0) {
570 			printf("%s:%d:%d: timeout waiting for DRQ, "
571 			    "st=0x%02x, err=0x%02x\n",
572 			    device_xname(atac->atac_dev), chp->ch_channel,
573 			    xfer->c_drive,
574 			    ATACH_ST(tfd), ATACH_ERR(tfd));
575 			if (wdc_ata_err(drvp, ata_bio, tfd) != WDC_ATA_ERR)
576 				ata_bio->error = TIMEOUT;
577 			return ATASTART_ABORT;
578 		}
579 		if (wdc_ata_err(drvp, ata_bio, tfd) == WDC_ATA_ERR) {
580 			return ATASTART_ABORT;
581 		}
582 #if NATA_PIOBM
583 		if (xfer->c_flags & C_PIOBM) {
584 			/* start the busmastering PIO */
585 			(*wdc->piobm_start)(wdc->dma_arg,
586 			    chp->ch_channel, xfer->c_drive,
587 			    xfer->c_skip, ata_bio->nbytes, 0);
588 			chp->ch_flags |= ATACH_DMA_WAIT;
589 		} else
590 #endif
591 
592 		wdc->dataout_pio(chp, drvp->drive_flags,
593 		    (char *)xfer->c_databuf + xfer->c_skip, ata_bio->nbytes);
594 	}
595 
596 #if NATA_DMA
597 intr:
598 #endif
599 	/* Wait for IRQ (either real or polled) */
600 	if ((ata_bio->flags & ATA_POLL) == 0) {
601 		chp->ch_flags |= ATACH_IRQ_WAIT;
602 		return ATASTART_STARTED;
603 	} else {
604 		return ATASTART_POLL;
605 	}
606 
607 timeout:
608 	printf("%s:%d:%d: not ready, st=0x%02x, err=0x%02x\n",
609 	    device_xname(atac->atac_dev), chp->ch_channel, xfer->c_drive,
610 	    ATACH_ST(tfd), ATACH_ERR(tfd));
611 	if (wdc_ata_err(drvp, ata_bio, tfd) != WDC_ATA_ERR)
612 		ata_bio->error = TIMEOUT;
613 	return ATASTART_ABORT;
614 }
615 
616 static void
617 wdc_ata_bio_poll(struct ata_channel *chp, struct ata_xfer *xfer)
618 {
619 	/* Wait for at last 400ns for status bit to be valid */
620 	delay(1);
621 #if NATA_DMA
622 	if (chp->ch_flags & ATACH_DMA_WAIT) {
623 		wdc_dmawait(chp, xfer, ATA_DELAY);
624 		chp->ch_flags &= ~ATACH_DMA_WAIT;
625 	}
626 #endif
627 	wdc_ata_bio_intr(chp, xfer, 0);
628 }
629 
630 static int
631 wdc_ata_bio_intr(struct ata_channel *chp, struct ata_xfer *xfer, int irq)
632 {
633 	struct atac_softc *atac = chp->ch_atac;
634 	struct wdc_softc *wdc = CHAN_TO_WDC(chp);
635 	struct ata_bio *ata_bio = &xfer->c_bio;
636 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->c_drive];
637 	int drv_err, tfd;
638 
639 	ATADEBUG_PRINT(("wdc_ata_bio_intr %s:%d:%d\n",
640 	    device_xname(atac->atac_dev), chp->ch_channel, xfer->c_drive),
641 	    DEBUG_INTR | DEBUG_XFERS);
642 
643 	ata_channel_lock(chp);
644 
645 	/* Is it not a transfer, but a control operation? */
646 	if (drvp->state < READY) {
647 		printf("%s:%d:%d: bad state %d in wdc_ata_bio_intr\n",
648 		    device_xname(atac->atac_dev), chp->ch_channel, xfer->c_drive,
649 		    drvp->state);
650 		panic("wdc_ata_bio_intr: bad state");
651 	}
652 
653 	/*
654 	 * if we missed an interrupt in a PIO transfer, reset and restart.
655 	 * Don't try to continue transfer, we may have missed cycles.
656 	 */
657 	if ((xfer->c_flags & (C_TIMEOU | C_DMA)) == C_TIMEOU) {
658 		ata_bio->error = TIMEOUT;
659 		goto err;
660 	}
661 
662 #if NATA_PIOBM
663 	/* Transfer-done interrupt for busmastering PIO read */
664 	if ((xfer->c_flags & C_PIOBM) && (chp->ch_flags & ATACH_PIOBM_WAIT)) {
665 		chp->ch_flags &= ~ATACH_PIOBM_WAIT;
666 		goto end;
667 	}
668 #endif
669 
670 	/* Ack interrupt done by wdc_wait_for_unbusy */
671 	if (wdc_wait_for_unbusy(chp,
672 	    (irq == 0) ? ATA_DELAY : 0, AT_POLL, &tfd) < 0) {
673 		if (irq && (xfer->c_flags & C_TIMEOU) == 0) {
674 			ata_channel_unlock(chp);
675 			return 0; /* IRQ was not for us */
676 		}
677 		printf("%s:%d:%d: device timeout, c_bcount=%d, c_skip%d\n",
678 		    device_xname(atac->atac_dev), chp->ch_channel,
679 		    xfer->c_drive, xfer->c_bcount, xfer->c_skip);
680 		ata_bio->error = TIMEOUT;
681 		goto err;
682 	}
683 	if (wdc->irqack)
684 		wdc->irqack(chp);
685 
686 	drv_err = wdc_ata_err(drvp, ata_bio, tfd);
687 
688 #if NATA_DMA
689 	/* If we were using DMA, Turn off the DMA channel and check for error */
690 	if (xfer->c_flags & C_DMA) {
691 		if (ata_bio->flags & ATA_POLL) {
692 			/*
693 			 * IDE drives deassert WDCS_BSY before transfer is
694 			 * complete when using DMA. Polling for DRQ to deassert
695 			 * is not enough DRQ is not required to be
696 			 * asserted for DMA transfers, so poll for DRDY.
697 			 */
698 			if (wdcwait(chp, WDCS_DRDY | WDCS_DRQ, WDCS_DRDY,
699 			    ATA_DELAY, ATA_POLL, &tfd) == WDCWAIT_TOUT) {
700 				printf("%s:%d:%d: polled transfer timed out "
701 				    "(st=0x%x)\n",
702 				    device_xname(atac->atac_dev),
703 				    chp->ch_channel, xfer->c_drive,
704 				    ATACH_ST(tfd));
705 				ata_bio->error = TIMEOUT;
706 				drv_err = WDC_ATA_ERR;
707 			}
708 		}
709 		if (wdc->dma_status != 0) {
710 			if (drv_err != WDC_ATA_ERR) {
711 				ata_bio->error = ERR_DMA;
712 				drv_err = WDC_ATA_ERR;
713 			}
714 		}
715 		if (ATACH_ST(tfd) & WDCS_DRQ) {
716 			if (drv_err != WDC_ATA_ERR) {
717 				printf("%s:%d:%d: intr with DRQ (st=0x%x)\n",
718 				    device_xname(atac->atac_dev),
719 				    chp->ch_channel,
720 				    xfer->c_drive, ATACH_ST(tfd));
721 				ata_bio->error = TIMEOUT;
722 				drv_err = WDC_ATA_ERR;
723 			}
724 		}
725 		if (drv_err != WDC_ATA_ERR)
726 			goto end;
727 		if (ata_bio->r_error & WDCE_CRC || ata_bio->error == ERR_DMA) {
728 			ata_channel_unlock(chp);
729 			ata_dmaerr(drvp,
730 			    (xfer->c_flags & C_POLL) ? AT_POLL : 0);
731 			ata_channel_lock(chp);
732 			goto err;
733 		}
734 	}
735 #endif	/* NATA_DMA */
736 
737 	/* if we had an error, end */
738 	if (drv_err == WDC_ATA_ERR)
739 		goto err;
740 
741 	/* If this was a read and not using DMA, fetch the data. */
742 	if ((ata_bio->flags & ATA_READ) != 0) {
743 		if ((ATACH_ST(tfd) & WDCS_DRQ) != WDCS_DRQ) {
744 			printf("%s:%d:%d: read intr before drq\n",
745 			    device_xname(atac->atac_dev), chp->ch_channel,
746 			    xfer->c_drive);
747 			ata_bio->error = TIMEOUT;
748 			goto err;
749 		}
750 #if NATA_PIOBM
751 		if (xfer->c_flags & C_PIOBM) {
752 			/* start the busmastering PIO */
753 			(*wdc->piobm_start)(wdc->dma_arg,
754 			    chp->ch_channel, xfer->c_drive,
755 			    xfer->c_skip, ata_bio->nbytes,
756 			    WDC_PIOBM_XFER_IRQ);
757 			chp->ch_flags |= ATACH_DMA_WAIT | ATACH_PIOBM_WAIT;
758 			ata_channel_unlock(chp);
759 			return 1;
760 		}
761 #endif
762 		wdc->datain_pio(chp, drvp->drive_flags,
763 		    (char *)xfer->c_databuf + xfer->c_skip, ata_bio->nbytes);
764 	}
765 
766 #if NATA_DMA || NATA_PIOBM
767 end:
768 #endif
769 	ata_bio->blkno += ata_bio->nblks;
770 	ata_bio->blkdone += ata_bio->nblks;
771 	xfer->c_skip += ata_bio->nbytes;
772 	xfer->c_bcount -= ata_bio->nbytes;
773 
774 	/* See if this transfer is complete. */
775 	if (xfer->c_bcount > 0) {
776 		if ((ata_bio->flags & ATA_POLL) == 0) {
777 			/* Start the next operation */
778 			ata_xfer_start(xfer);
779 		} else {
780 			/* Let _wdc_ata_bio_start do the loop */
781 		}
782 		ata_channel_unlock(chp);
783 		return 1;
784 	}
785 
786 	/* Done with this transfer */
787 	ata_bio->error = NOERROR;
788 err:	ata_channel_unlock(chp);
789 	wdc_ata_bio_done(chp, xfer);
790 	return 1;
791 }
792 
793 static void
794 wdc_ata_bio_kill_xfer(struct ata_channel *chp, struct ata_xfer *xfer,
795     int reason)
796 {
797 	struct ata_bio *ata_bio = &xfer->c_bio;
798 	int drive = xfer->c_drive;
799 	bool deactivate = true;
800 
801 	ata_bio->flags |= ATA_ITSDONE;
802 	switch (reason) {
803 	case KILL_GONE_INACTIVE:
804 		deactivate = false;
805 		/* FALLTHROUGH */
806 	case KILL_GONE:
807 		ata_bio->error = ERR_NODEV;
808 		break;
809 	case KILL_RESET:
810 		ata_bio->error = ERR_RESET;
811 		break;
812 	default:
813 		printf("wdc_ata_bio_kill_xfer: unknown reason %d\n",
814 		    reason);
815 		panic("wdc_ata_bio_kill_xfer");
816 	}
817 	ata_bio->r_error = WDCE_ABRT;
818 
819 	if (deactivate)
820 		ata_deactivate_xfer(chp, xfer);
821 
822 	ATADEBUG_PRINT(("wdc_ata_bio_kill_xfer: drv_done\n"), DEBUG_XFERS);
823 	(*chp->ch_drive[drive].drv_done)(chp->ch_drive[drive].drv_softc, xfer);
824 }
825 
826 static void
827 wdc_ata_bio_done(struct ata_channel *chp, struct ata_xfer *xfer)
828 {
829 	struct ata_bio *ata_bio = &xfer->c_bio;
830 	int drive = xfer->c_drive;
831 
832 	ATADEBUG_PRINT(("wdc_ata_bio_done %s:%d:%d: flags 0x%x\n",
833 	    device_xname(chp->ch_atac->atac_dev), chp->ch_channel,
834 	    xfer->c_drive, (u_int)xfer->c_flags),
835 	    DEBUG_XFERS);
836 
837 	if (ata_waitdrain_xfer_check(chp, xfer))
838 		return;
839 
840 	/* feed back residual bcount to our caller */
841 	ata_bio->bcount = xfer->c_bcount;
842 
843 	/* mark controller inactive and free xfer */
844 	ata_deactivate_xfer(chp, xfer);
845 
846 	ata_bio->flags |= ATA_ITSDONE;
847 	ATADEBUG_PRINT(("wdc_ata_done: drv_done\n"), DEBUG_XFERS);
848 	(*chp->ch_drive[drive].drv_done)(chp->ch_drive[drive].drv_softc, xfer);
849 	ATADEBUG_PRINT(("atastart from wdc_ata_done, flags 0x%x\n",
850 	    chp->ch_flags), DEBUG_XFERS);
851 	atastart(chp);
852 }
853 
854 static int
855 wdc_ata_err(struct ata_drive_datas *drvp, struct ata_bio *ata_bio, int tfd)
856 {
857 	ata_bio->error = 0;
858 	if (ATACH_ST(tfd) & WDCS_BSY) {
859 		ata_bio->error = TIMEOUT;
860 		return WDC_ATA_ERR;
861 	}
862 
863 	if (ATACH_ST(tfd) & WDCS_DWF) {
864 		ata_bio->error = ERR_DF;
865 		return WDC_ATA_ERR;
866 	}
867 
868 	if (ATACH_ST(tfd) & WDCS_ERR) {
869 		ata_bio->error = ERROR;
870 		ata_bio->r_error = ATACH_ERR(tfd);
871 		if (ata_bio->r_error & (WDCE_BBK | WDCE_UNC | WDCE_IDNF |
872 		    WDCE_ABRT | WDCE_TK0NF | WDCE_AMNF))
873 			return WDC_ATA_ERR;
874 		return WDC_ATA_NOERR;
875 	}
876 
877 	if (ATACH_ST(tfd) & WDCS_CORR)
878 		ata_bio->flags |= ATA_CORR;
879 	return WDC_ATA_NOERR;
880 }
881 
882 static int
883 wdc_ata_addref(struct ata_drive_datas *drvp)
884 {
885 	struct ata_channel *chp = drvp->chnl_softc;
886 
887 	return (ata_addref(chp));
888 }
889 
890 static void
891 wdc_ata_delref(struct ata_drive_datas *drvp)
892 {
893 	struct ata_channel *chp = drvp->chnl_softc;
894 
895 	ata_delref(chp);
896 }
897