xref: /netbsd-src/sys/dev/ata/ata.c (revision 1b9578b8c2c1f848eeb16dabbfd7d1f0d9fdefbd)
1 /*	$NetBSD: ata.c,v 1.115 2011/04/30 00:34:03 jakllsch Exp $	*/
2 
3 /*
4  * Copyright (c) 1998, 2001 Manuel Bouyer.  All rights reserved.
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 #include <sys/cdefs.h>
28 __KERNEL_RCSID(0, "$NetBSD: ata.c,v 1.115 2011/04/30 00:34:03 jakllsch Exp $");
29 
30 #include "opt_ata.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/malloc.h>
36 #include <sys/device.h>
37 #include <sys/conf.h>
38 #include <sys/fcntl.h>
39 #include <sys/proc.h>
40 #include <sys/pool.h>
41 #include <sys/kthread.h>
42 #include <sys/errno.h>
43 #include <sys/ataio.h>
44 #include <sys/kmem.h>
45 #include <sys/intr.h>
46 #include <sys/bus.h>
47 #include <sys/once.h>
48 
49 #include <dev/ata/ataconf.h>
50 #include <dev/ata/atareg.h>
51 #include <dev/ata/atavar.h>
52 #include <dev/ic/wdcvar.h>	/* for PIOBM */
53 
54 #include "locators.h"
55 
56 #include "atapibus.h"
57 #include "ataraid.h"
58 
59 #if NATARAID > 0
60 #include <dev/ata/ata_raidvar.h>
61 #endif
62 
63 #define DEBUG_FUNCS  0x08
64 #define DEBUG_PROBE  0x10
65 #define DEBUG_DETACH 0x20
66 #define	DEBUG_XFERS  0x40
67 #ifdef ATADEBUG
68 int atadebug_mask = 0;
69 #define ATADEBUG_PRINT(args, level) \
70 	if (atadebug_mask & (level)) \
71 		printf args
72 #else
73 #define ATADEBUG_PRINT(args, level)
74 #endif
75 
76 static ONCE_DECL(ata_init_ctrl);
77 static struct pool ata_xfer_pool;
78 
79 /*
80  * A queue of atabus instances, used to ensure the same bus probe order
81  * for a given hardware configuration at each boot.  Kthread probing
82  * devices on a atabus.  Only one probing at once.
83  */
84 static TAILQ_HEAD(, atabus_initq)	atabus_initq_head;
85 static kmutex_t				atabus_qlock;
86 static kcondvar_t			atabus_qcv;
87 static lwp_t *				atabus_cfg_lwp;
88 
89 /*****************************************************************************
90  * ATA bus layer.
91  *
92  * ATA controllers attach an atabus instance, which handles probing the bus
93  * for drives, etc.
94  *****************************************************************************/
95 
96 dev_type_open(atabusopen);
97 dev_type_close(atabusclose);
98 dev_type_ioctl(atabusioctl);
99 
100 const struct cdevsw atabus_cdevsw = {
101 	atabusopen, atabusclose, noread, nowrite, atabusioctl,
102 	nostop, notty, nopoll, nommap, nokqfilter, D_OTHER
103 };
104 
105 extern struct cfdriver atabus_cd;
106 
107 static void atabus_childdetached(device_t, device_t);
108 static int atabus_rescan(device_t, const char *, const int *);
109 static bool atabus_resume(device_t, const pmf_qual_t *);
110 static bool atabus_suspend(device_t, const pmf_qual_t *);
111 static void atabusconfig_thread(void *);
112 
113 /*
114  * atabus_init:
115  *
116  *	Initialize ATA subsystem structures.
117  */
118 static int
119 atabus_init(void)
120 {
121 
122 	pool_init(&ata_xfer_pool, sizeof(struct ata_xfer), 0, 0, 0,
123 	    "ataspl", NULL, IPL_BIO);
124 	TAILQ_INIT(&atabus_initq_head);
125 	mutex_init(&atabus_qlock, MUTEX_DEFAULT, IPL_NONE);
126 	cv_init(&atabus_qcv, "atainitq");
127 	return 0;
128 }
129 
130 /*
131  * atabusprint:
132  *
133  *	Autoconfiguration print routine used by ATA controllers when
134  *	attaching an atabus instance.
135  */
136 int
137 atabusprint(void *aux, const char *pnp)
138 {
139 	struct ata_channel *chan = aux;
140 
141 	if (pnp)
142 		aprint_normal("atabus at %s", pnp);
143 	aprint_normal(" channel %d", chan->ch_channel);
144 
145 	return (UNCONF);
146 }
147 
148 /*
149  * ataprint:
150  *
151  *	Autoconfiguration print routine.
152  */
153 int
154 ataprint(void *aux, const char *pnp)
155 {
156 	struct ata_device *adev = aux;
157 
158 	if (pnp)
159 		aprint_normal("wd at %s", pnp);
160 	aprint_normal(" drive %d", adev->adev_drv_data->drive);
161 
162 	return (UNCONF);
163 }
164 
165 /*
166  * ata_channel_attach:
167  *
168  *	Common parts of attaching an atabus to an ATA controller channel.
169  */
170 void
171 ata_channel_attach(struct ata_channel *chp)
172 {
173 
174 	if (chp->ch_flags & ATACH_DISABLED)
175 		return;
176 
177 	/* XXX callout_destroy */
178 	callout_init(&chp->ch_callout, 0);
179 
180 	TAILQ_INIT(&chp->ch_queue->queue_xfer);
181 	chp->ch_queue->queue_freeze = 0;
182 	chp->ch_queue->queue_flags = 0;
183 	chp->ch_queue->active_xfer = NULL;
184 
185 	chp->atabus = config_found_ia(chp->ch_atac->atac_dev, "ata", chp,
186 		atabusprint);
187 }
188 
189 static void
190 atabusconfig(struct atabus_softc *atabus_sc)
191 {
192 	struct ata_channel *chp = atabus_sc->sc_chan;
193 	struct atac_softc *atac = chp->ch_atac;
194 	struct atabus_initq *atabus_initq = NULL;
195 	int i, s, error;
196 
197 	/* we are in the atabus's thread context */
198 	s = splbio();
199 	chp->ch_flags |= ATACH_TH_RUN;
200 	splx(s);
201 
202 	/* Probe for the drives. */
203 	/* XXX for SATA devices we will power up all drives at once */
204 	(*atac->atac_probe)(chp);
205 
206 	ATADEBUG_PRINT(("atabusattach: ch_drive_flags 0x%x 0x%x\n",
207 	    chp->ch_drive[0].drive_flags, chp->ch_drive[1].drive_flags),
208 	    DEBUG_PROBE);
209 
210 	/* next operations will occurs in a separate thread */
211 	s = splbio();
212 	chp->ch_flags &= ~ATACH_TH_RUN;
213 	splx(s);
214 
215 	/* Make sure the devices probe in atabus order to avoid jitter. */
216 	mutex_enter(&atabus_qlock);
217 	for (;;) {
218 		atabus_initq = TAILQ_FIRST(&atabus_initq_head);
219 		if (atabus_initq->atabus_sc == atabus_sc)
220 			break;
221 		cv_wait(&atabus_qcv, &atabus_qlock);
222 	}
223 	mutex_exit(&atabus_qlock);
224 
225 	/* If no drives, abort here */
226 	for (i = 0; i < chp->ch_ndrive; i++)
227 		if ((chp->ch_drive[i].drive_flags & DRIVE) != 0)
228 			break;
229 	if (i == chp->ch_ndrive)
230 		goto out;
231 
232 	/* Shortcut in case we've been shutdown */
233 	if (chp->ch_flags & ATACH_SHUTDOWN)
234 		goto out;
235 
236 
237 	if ((error = kthread_create(PRI_NONE, 0, NULL, atabusconfig_thread,
238 	    atabus_sc, &atabus_cfg_lwp,
239 	    "%scnf", device_xname(atac->atac_dev))) != 0)
240 		aprint_error_dev(atac->atac_dev,
241 		    "unable to create config thread: error %d\n", error);
242 	return;
243 
244  out:
245 	mutex_enter(&atabus_qlock);
246 	TAILQ_REMOVE(&atabus_initq_head, atabus_initq, atabus_initq);
247 	cv_broadcast(&atabus_qcv);
248 	mutex_exit(&atabus_qlock);
249 
250 	free(atabus_initq, M_DEVBUF);
251 
252 	ata_delref(chp);
253 
254 	config_pending_decr();
255 }
256 
257 /*
258  * atabus_configthread: finish attach of atabus's childrens, in a separate
259  * kernel thread.
260  */
261 static void
262 atabusconfig_thread(void *arg)
263 {
264 	struct atabus_softc *atabus_sc = arg;
265 	struct ata_channel *chp = atabus_sc->sc_chan;
266 	struct atac_softc *atac = chp->ch_atac;
267 	struct atabus_initq *atabus_initq = NULL;
268 	int i, s;
269 
270 	/* XXX seems wrong */
271 	mutex_enter(&atabus_qlock);
272 	atabus_initq = TAILQ_FIRST(&atabus_initq_head);
273 	KASSERT(atabus_initq->atabus_sc == atabus_sc);
274 	mutex_exit(&atabus_qlock);
275 
276 	/*
277 	 * Attach an ATAPI bus, if needed.
278 	 */
279 	for (i = 0; i < chp->ch_ndrive; i++) {
280 		if (chp->ch_drive[i].drive_flags & DRIVE_ATAPI) {
281 #if NATAPIBUS > 0
282 			(*atac->atac_atapibus_attach)(atabus_sc);
283 #else
284 			/*
285 			 * Fake the autoconfig "not configured" message
286 			 */
287 			aprint_normal("atapibus at %s not configured\n",
288 			    device_xname(atac->atac_dev));
289 			chp->atapibus = NULL;
290 			s = splbio();
291 			for (i = 0; i < chp->ch_ndrive; i++)
292 				chp->ch_drive[i].drive_flags &= ~DRIVE_ATAPI;
293 			splx(s);
294 #endif
295 			break;
296 		}
297 	}
298 
299 	for (i = 0; i < chp->ch_ndrive; i++) {
300 		struct ata_device adev;
301 		if ((chp->ch_drive[i].drive_flags &
302 		    (DRIVE_ATA | DRIVE_OLD)) == 0) {
303 			continue;
304 		}
305 		memset(&adev, 0, sizeof(struct ata_device));
306 		adev.adev_bustype = atac->atac_bustype_ata;
307 		adev.adev_channel = chp->ch_channel;
308 		adev.adev_openings = 1;
309 		adev.adev_drv_data = &chp->ch_drive[i];
310 		chp->ata_drives[i] = config_found_ia(atabus_sc->sc_dev,
311 		    "ata_hl", &adev, ataprint);
312 		if (chp->ata_drives[i] != NULL)
313 			ata_probe_caps(&chp->ch_drive[i]);
314 		else {
315 			s = splbio();
316 			chp->ch_drive[i].drive_flags &=
317 			    ~(DRIVE_ATA | DRIVE_OLD);
318 			splx(s);
319 		}
320 	}
321 
322 	/* now that we know the drives, the controller can set its modes */
323 	if (atac->atac_set_modes) {
324 		(*atac->atac_set_modes)(chp);
325 		ata_print_modes(chp);
326 	}
327 #if NATARAID > 0
328 	if (atac->atac_cap & ATAC_CAP_RAID)
329 		for (i = 0; i < chp->ch_ndrive; i++)
330 			if (chp->ata_drives[i] != NULL)
331 				ata_raid_check_component(chp->ata_drives[i]);
332 #endif /* NATARAID > 0 */
333 
334 	/*
335 	 * reset drive_flags for unattached devices, reset state for attached
336 	 * ones
337 	 */
338 	s = splbio();
339 	for (i = 0; i < chp->ch_ndrive; i++) {
340 		if (chp->ch_drive[i].drv_softc == NULL)
341 			chp->ch_drive[i].drive_flags = 0;
342 		else
343 			chp->ch_drive[i].state = 0;
344 	}
345 	splx(s);
346 
347 	mutex_enter(&atabus_qlock);
348 	TAILQ_REMOVE(&atabus_initq_head, atabus_initq, atabus_initq);
349 	cv_broadcast(&atabus_qcv);
350 	mutex_exit(&atabus_qlock);
351 
352 	free(atabus_initq, M_DEVBUF);
353 
354 	ata_delref(chp);
355 
356 	config_pending_decr();
357 	kthread_exit(0);
358 }
359 
360 /*
361  * atabus_thread:
362  *
363  *	Worker thread for the ATA bus.
364  */
365 static void
366 atabus_thread(void *arg)
367 {
368 	struct atabus_softc *sc = arg;
369 	struct ata_channel *chp = sc->sc_chan;
370 	struct ata_xfer *xfer;
371 	int i, s;
372 
373 	s = splbio();
374 	chp->ch_flags |= ATACH_TH_RUN;
375 
376 	/*
377 	 * Probe the drives.  Reset all flags to 0 to indicate to controllers
378 	 * that can re-probe that all drives must be probed..
379 	 *
380 	 * Note: ch_ndrive may be changed during the probe.
381 	 */
382 	for (i = 0; i < ATA_MAXDRIVES; i++)
383 		chp->ch_drive[i].drive_flags = 0;
384 	splx(s);
385 
386 	atabusconfig(sc);
387 
388 	s = splbio();
389 	for (;;) {
390 		if ((chp->ch_flags & (ATACH_TH_RESET | ATACH_SHUTDOWN)) == 0 &&
391 		    (chp->ch_queue->active_xfer == NULL ||
392 		     chp->ch_queue->queue_freeze == 0)) {
393 			chp->ch_flags &= ~ATACH_TH_RUN;
394 			(void) tsleep(&chp->ch_thread, PRIBIO, "atath", 0);
395 			chp->ch_flags |= ATACH_TH_RUN;
396 		}
397 		if (chp->ch_flags & ATACH_SHUTDOWN) {
398 			break;
399 		}
400 		if (chp->ch_flags & ATACH_TH_RESCAN) {
401 			atabusconfig(sc);
402 			chp->ch_flags &= ~ATACH_TH_RESCAN;
403 		}
404 		if (chp->ch_flags & ATACH_TH_RESET) {
405 			/*
406 			 * ata_reset_channel() will freeze 2 times, so
407 			 * unfreeze one time. Not a problem as we're at splbio
408 			 */
409 			chp->ch_queue->queue_freeze--;
410 			ata_reset_channel(chp, AT_WAIT | chp->ch_reset_flags);
411 		} else if (chp->ch_queue->active_xfer != NULL &&
412 			   chp->ch_queue->queue_freeze == 1) {
413 			/*
414 			 * Caller has bumped queue_freeze, decrease it.
415 			 */
416 			chp->ch_queue->queue_freeze--;
417 			xfer = chp->ch_queue->active_xfer;
418 			KASSERT(xfer != NULL);
419 			(*xfer->c_start)(xfer->c_chp, xfer);
420 		} else if (chp->ch_queue->queue_freeze > 1)
421 			panic("ata_thread: queue_freeze");
422 	}
423 	splx(s);
424 	chp->ch_thread = NULL;
425 	wakeup(&chp->ch_flags);
426 	kthread_exit(0);
427 }
428 
429 /*
430  * atabus_match:
431  *
432  *	Autoconfiguration match routine.
433  */
434 static int
435 atabus_match(device_t parent, cfdata_t cf, void *aux)
436 {
437 	struct ata_channel *chp = aux;
438 
439 	if (chp == NULL)
440 		return (0);
441 
442 	if (cf->cf_loc[ATACF_CHANNEL] != chp->ch_channel &&
443 	    cf->cf_loc[ATACF_CHANNEL] != ATACF_CHANNEL_DEFAULT)
444 		return (0);
445 
446 	return (1);
447 }
448 
449 /*
450  * atabus_attach:
451  *
452  *	Autoconfiguration attach routine.
453  */
454 static void
455 atabus_attach(device_t parent, device_t self, void *aux)
456 {
457 	struct atabus_softc *sc = device_private(self);
458 	struct ata_channel *chp = aux;
459 	struct atabus_initq *initq;
460 	int error;
461 
462 	sc->sc_chan = chp;
463 
464 	aprint_normal("\n");
465 	aprint_naive("\n");
466 
467 	sc->sc_dev = self;
468 
469 	if (ata_addref(chp))
470 		return;
471 
472 	RUN_ONCE(&ata_init_ctrl, atabus_init);
473 
474 	initq = malloc(sizeof(*initq), M_DEVBUF, M_WAITOK);
475 	initq->atabus_sc = sc;
476 	TAILQ_INSERT_TAIL(&atabus_initq_head, initq, atabus_initq);
477 	config_pending_incr();
478 
479 	if ((error = kthread_create(PRI_NONE, 0, NULL, atabus_thread, sc,
480 	    &chp->ch_thread, "%s", device_xname(self))) != 0)
481 		aprint_error_dev(self,
482 		    "unable to create kernel thread: error %d\n", error);
483 
484 	if (!pmf_device_register(self, atabus_suspend, atabus_resume))
485 		aprint_error_dev(self, "couldn't establish power handler\n");
486 }
487 
488 /*
489  * atabus_detach:
490  *
491  *	Autoconfiguration detach routine.
492  */
493 static int
494 atabus_detach(device_t self, int flags)
495 {
496 	struct atabus_softc *sc = device_private(self);
497 	struct ata_channel *chp = sc->sc_chan;
498 	device_t dev = NULL;
499 	int s, i, error = 0;
500 
501 	/* Shutdown the channel. */
502 	s = splbio();		/* XXX ALSO NEED AN INTERLOCK HERE. */
503 	chp->ch_flags |= ATACH_SHUTDOWN;
504 	splx(s);
505 
506 	wakeup(&chp->ch_thread);
507 
508 	while (chp->ch_thread != NULL)
509 		(void) tsleep(&chp->ch_flags, PRIBIO, "atadown", 0);
510 
511 
512 	/*
513 	 * Detach atapibus and its children.
514 	 */
515 	if ((dev = chp->atapibus) != NULL) {
516 		ATADEBUG_PRINT(("atabus_detach: %s: detaching %s\n",
517 		    device_xname(self), device_xname(dev)), DEBUG_DETACH);
518 
519 		error = config_detach(dev, flags);
520 		if (error)
521 			goto out;
522 		KASSERT(chp->atapibus == NULL);
523 	}
524 
525 	/*
526 	 * Detach our other children.
527 	 */
528 	for (i = 0; i < chp->ch_ndrive; i++) {
529 		if (chp->ch_drive[i].drive_flags & DRIVE_ATAPI)
530 			continue;
531 		if ((dev = chp->ata_drives[i]) != NULL) {
532 			ATADEBUG_PRINT(("%s.%d: %s: detaching %s\n", __func__,
533 			    __LINE__, device_xname(self), device_xname(dev)),
534 			    DEBUG_DETACH);
535 			KASSERT(chp->ch_drive[i].drv_softc ==
536 			        chp->ata_drives[i]);
537 			error = config_detach(dev, flags);
538 			if (error)
539 				goto out;
540 			KASSERT(chp->ata_drives[i] == NULL);
541 		}
542 	}
543 
544  out:
545 #ifdef ATADEBUG
546 	if (dev != NULL && error != 0)
547 		ATADEBUG_PRINT(("%s: %s: error %d detaching %s\n", __func__,
548 		    device_xname(self), error, device_xname(dev)),
549 		    DEBUG_DETACH);
550 #endif /* ATADEBUG */
551 
552 	return (error);
553 }
554 
555 void
556 atabus_childdetached(device_t self, device_t child)
557 {
558 	bool found = false;
559 	struct atabus_softc *sc = device_private(self);
560 	struct ata_channel *chp = sc->sc_chan;
561 	int i;
562 
563 	/*
564 	 * atapibus detached.
565 	 */
566 	if (child == chp->atapibus) {
567 		chp->atapibus = NULL;
568 		found = true;
569 	}
570 
571 	/*
572 	 * Detach our other children.
573 	 */
574 	for (i = 0; i < chp->ch_ndrive; i++) {
575 		if (chp->ch_drive[i].drive_flags & DRIVE_ATAPI)
576 			continue;
577 		if (child == chp->ata_drives[i]) {
578 			KASSERT(chp->ata_drives[i] ==
579 			        chp->ch_drive[i].drv_softc);
580 			chp->ata_drives[i] = NULL;
581 			chp->ch_drive[i].drv_softc = NULL;
582 			chp->ch_drive[i].drive_flags = 0;
583 			found = true;
584 		}
585 	}
586 
587 	if (!found)
588 		panic("%s: unknown child %p", device_xname(self),
589 		    (const void *)child);
590 }
591 
592 CFATTACH_DECL3_NEW(atabus, sizeof(struct atabus_softc),
593     atabus_match, atabus_attach, atabus_detach, NULL, atabus_rescan,
594     atabus_childdetached, DVF_DETACH_SHUTDOWN);
595 
596 /*****************************************************************************
597  * Common ATA bus operations.
598  *****************************************************************************/
599 
600 /* Get the disk's parameters */
601 int
602 ata_get_params(struct ata_drive_datas *drvp, u_int8_t flags,
603     struct ataparams *prms)
604 {
605 	struct ata_command ata_c;
606 	struct ata_channel *chp = drvp->chnl_softc;
607 	struct atac_softc *atac = chp->ch_atac;
608 	char *tb;
609 	int i, rv;
610 	u_int16_t *p;
611 
612 	ATADEBUG_PRINT(("%s\n", __func__), DEBUG_FUNCS);
613 
614 	tb = kmem_zalloc(DEV_BSIZE, KM_SLEEP);
615 	memset(prms, 0, sizeof(struct ataparams));
616 	memset(&ata_c, 0, sizeof(struct ata_command));
617 
618 	if (drvp->drive_flags & DRIVE_ATA) {
619 		ata_c.r_command = WDCC_IDENTIFY;
620 		ata_c.r_st_bmask = WDCS_DRDY;
621 		ata_c.r_st_pmask = WDCS_DRQ;
622 		ata_c.timeout = 3000; /* 3s */
623 	} else if (drvp->drive_flags & DRIVE_ATAPI) {
624 		ata_c.r_command = ATAPI_IDENTIFY_DEVICE;
625 		ata_c.r_st_bmask = 0;
626 		ata_c.r_st_pmask = WDCS_DRQ;
627 		ata_c.timeout = 10000; /* 10s */
628 	} else {
629 		ATADEBUG_PRINT(("ata_get_parms: no disks\n"),
630 		    DEBUG_FUNCS|DEBUG_PROBE);
631 		rv = CMD_ERR;
632 		goto out;
633 	}
634 	ata_c.flags = AT_READ | flags;
635 	ata_c.data = tb;
636 	ata_c.bcount = DEV_BSIZE;
637 	if ((*atac->atac_bustype_ata->ata_exec_command)(drvp,
638 						&ata_c) != ATACMD_COMPLETE) {
639 		ATADEBUG_PRINT(("ata_get_parms: wdc_exec_command failed\n"),
640 		    DEBUG_FUNCS|DEBUG_PROBE);
641 		rv = CMD_AGAIN;
642 		goto out;
643 	}
644 	if (ata_c.flags & (AT_ERROR | AT_TIMEOU | AT_DF)) {
645 		ATADEBUG_PRINT(("ata_get_parms: ata_c.flags=0x%x\n",
646 		    ata_c.flags), DEBUG_FUNCS|DEBUG_PROBE);
647 		rv = CMD_ERR;
648 		goto out;
649 	}
650 	/* if we didn't read any data something is wrong */
651 	if ((ata_c.flags & AT_XFDONE) == 0) {
652 		rv = CMD_ERR;
653 		goto out;
654 	}
655 
656 	/* Read in parameter block. */
657 	memcpy(prms, tb, sizeof(struct ataparams));
658 
659 	/*
660 	 * Shuffle string byte order.
661 	 * ATAPI NEC, Mitsumi and Pioneer drives and
662 	 * old ATA TDK CompactFlash cards
663 	 * have different byte order.
664 	 */
665 #if BYTE_ORDER == BIG_ENDIAN
666 # define M(n)	prms->atap_model[(n) ^ 1]
667 #else
668 # define M(n)	prms->atap_model[n]
669 #endif
670 	if (
671 #if BYTE_ORDER == BIG_ENDIAN
672 	    !
673 #endif
674 	    ((drvp->drive_flags & DRIVE_ATAPI) ?
675 	     ((M(0) == 'N' && M(1) == 'E') ||
676 	      (M(0) == 'F' && M(1) == 'X') ||
677 	      (M(0) == 'P' && M(1) == 'i')) :
678 	     ((M(0) == 'T' && M(1) == 'D' && M(2) == 'K')))) {
679 		rv = CMD_OK;
680 		goto out;
681 	     }
682 #undef M
683 	for (i = 0; i < sizeof(prms->atap_model); i += 2) {
684 		p = (u_int16_t *)(prms->atap_model + i);
685 		*p = bswap16(*p);
686 	}
687 	for (i = 0; i < sizeof(prms->atap_serial); i += 2) {
688 		p = (u_int16_t *)(prms->atap_serial + i);
689 		*p = bswap16(*p);
690 	}
691 	for (i = 0; i < sizeof(prms->atap_revision); i += 2) {
692 		p = (u_int16_t *)(prms->atap_revision + i);
693 		*p = bswap16(*p);
694 	}
695 
696 	rv = CMD_OK;
697  out:
698 	kmem_free(tb, DEV_BSIZE);
699 	return rv;
700 }
701 
702 int
703 ata_set_mode(struct ata_drive_datas *drvp, u_int8_t mode, u_int8_t flags)
704 {
705 	struct ata_command ata_c;
706 	struct ata_channel *chp = drvp->chnl_softc;
707 	struct atac_softc *atac = chp->ch_atac;
708 
709 	ATADEBUG_PRINT(("ata_set_mode=0x%x\n", mode), DEBUG_FUNCS);
710 	memset(&ata_c, 0, sizeof(struct ata_command));
711 
712 	ata_c.r_command = SET_FEATURES;
713 	ata_c.r_st_bmask = 0;
714 	ata_c.r_st_pmask = 0;
715 	ata_c.r_features = WDSF_SET_MODE;
716 	ata_c.r_count = mode;
717 	ata_c.flags = flags;
718 	ata_c.timeout = 1000; /* 1s */
719 	if ((*atac->atac_bustype_ata->ata_exec_command)(drvp,
720 						&ata_c) != ATACMD_COMPLETE)
721 		return CMD_AGAIN;
722 	if (ata_c.flags & (AT_ERROR | AT_TIMEOU | AT_DF)) {
723 		return CMD_ERR;
724 	}
725 	return CMD_OK;
726 }
727 
728 #if NATA_DMA
729 void
730 ata_dmaerr(struct ata_drive_datas *drvp, int flags)
731 {
732 	/*
733 	 * Downgrade decision: if we get NERRS_MAX in NXFER.
734 	 * We start with n_dmaerrs set to NERRS_MAX-1 so that the
735 	 * first error within the first NXFER ops will immediatly trigger
736 	 * a downgrade.
737 	 * If we got an error and n_xfers is bigger than NXFER reset counters.
738 	 */
739 	drvp->n_dmaerrs++;
740 	if (drvp->n_dmaerrs >= NERRS_MAX && drvp->n_xfers <= NXFER) {
741 		ata_downgrade_mode(drvp, flags);
742 		drvp->n_dmaerrs = NERRS_MAX-1;
743 		drvp->n_xfers = 0;
744 		return;
745 	}
746 	if (drvp->n_xfers > NXFER) {
747 		drvp->n_dmaerrs = 1; /* just got an error */
748 		drvp->n_xfers = 1; /* restart counting from this error */
749 	}
750 }
751 #endif	/* NATA_DMA */
752 
753 /*
754  * freeze the queue and wait for the controller to be idle. Caller has to
755  * unfreeze/restart the queue
756  */
757 void
758 ata_queue_idle(struct ata_queue *queue)
759 {
760 	int s = splbio();
761 	queue->queue_freeze++;
762 	while (queue->active_xfer != NULL) {
763 		queue->queue_flags |= QF_IDLE_WAIT;
764 		tsleep(&queue->queue_flags, PRIBIO, "qidl", 0);
765 	}
766 	splx(s);
767 }
768 
769 /*
770  * Add a command to the queue and start controller.
771  *
772  * MUST BE CALLED AT splbio()!
773  */
774 void
775 ata_exec_xfer(struct ata_channel *chp, struct ata_xfer *xfer)
776 {
777 
778 	ATADEBUG_PRINT(("ata_exec_xfer %p channel %d drive %d\n", xfer,
779 	    chp->ch_channel, xfer->c_drive), DEBUG_XFERS);
780 
781 	/* complete xfer setup */
782 	xfer->c_chp = chp;
783 
784 	/* insert at the end of command list */
785 	TAILQ_INSERT_TAIL(&chp->ch_queue->queue_xfer, xfer, c_xferchain);
786 	ATADEBUG_PRINT(("atastart from ata_exec_xfer, flags 0x%x\n",
787 	    chp->ch_flags), DEBUG_XFERS);
788 	/*
789 	 * if polling and can sleep, wait for the xfer to be at head of queue
790 	 */
791 	if ((xfer->c_flags & (C_POLL | C_WAIT)) ==  (C_POLL | C_WAIT)) {
792 		while (chp->ch_queue->active_xfer != NULL ||
793 		    TAILQ_FIRST(&chp->ch_queue->queue_xfer) != xfer) {
794 			xfer->c_flags |= C_WAITACT;
795 			tsleep(xfer, PRIBIO, "ataact", 0);
796 			xfer->c_flags &= ~C_WAITACT;
797 			if (xfer->c_flags & C_FREE) {
798 				ata_free_xfer(chp, xfer);
799 				return;
800 			}
801 		}
802 	}
803 	atastart(chp);
804 }
805 
806 /*
807  * Start I/O on a controller, for the given channel.
808  * The first xfer may be not for our channel if the channel queues
809  * are shared.
810  *
811  * MUST BE CALLED AT splbio()!
812  */
813 void
814 atastart(struct ata_channel *chp)
815 {
816 	struct atac_softc *atac = chp->ch_atac;
817 	struct ata_xfer *xfer;
818 
819 #ifdef ATA_DEBUG
820 	int spl1, spl2;
821 
822 	spl1 = splbio();
823 	spl2 = splbio();
824 	if (spl2 != spl1) {
825 		printf("atastart: not at splbio()\n");
826 		panic("atastart");
827 	}
828 	splx(spl2);
829 	splx(spl1);
830 #endif /* ATA_DEBUG */
831 
832 	/* is there a xfer ? */
833 	if ((xfer = TAILQ_FIRST(&chp->ch_queue->queue_xfer)) == NULL)
834 		return;
835 
836 	/* adjust chp, in case we have a shared queue */
837 	chp = xfer->c_chp;
838 
839 	if (chp->ch_queue->active_xfer != NULL) {
840 		return; /* channel aleady active */
841 	}
842 	if (__predict_false(chp->ch_queue->queue_freeze > 0)) {
843 		if (chp->ch_queue->queue_flags & QF_IDLE_WAIT) {
844 			chp->ch_queue->queue_flags &= ~QF_IDLE_WAIT;
845 			wakeup(&chp->ch_queue->queue_flags);
846 		}
847 		return; /* queue frozen */
848 	}
849 	/*
850 	 * if someone is waiting for the command to be active, wake it up
851 	 * and let it process the command
852 	 */
853 	if (xfer->c_flags & C_WAITACT) {
854 		ATADEBUG_PRINT(("atastart: xfer %p channel %d drive %d "
855 		    "wait active\n", xfer, chp->ch_channel, xfer->c_drive),
856 		    DEBUG_XFERS);
857 		wakeup(xfer);
858 		return;
859 	}
860 #ifdef DIAGNOSTIC
861 	if ((chp->ch_flags & ATACH_IRQ_WAIT) != 0)
862 		panic("atastart: channel waiting for irq");
863 #endif
864 	if (atac->atac_claim_hw)
865 		if (!(*atac->atac_claim_hw)(chp, 0))
866 			return;
867 
868 	ATADEBUG_PRINT(("atastart: xfer %p channel %d drive %d\n", xfer,
869 	    chp->ch_channel, xfer->c_drive), DEBUG_XFERS);
870 	if (chp->ch_drive[xfer->c_drive].drive_flags & DRIVE_RESET) {
871 		chp->ch_drive[xfer->c_drive].drive_flags &= ~DRIVE_RESET;
872 		chp->ch_drive[xfer->c_drive].state = 0;
873 	}
874 	chp->ch_queue->active_xfer = xfer;
875 	TAILQ_REMOVE(&chp->ch_queue->queue_xfer, xfer, c_xferchain);
876 
877 	if (atac->atac_cap & ATAC_CAP_NOIRQ)
878 		KASSERT(xfer->c_flags & C_POLL);
879 
880 	xfer->c_start(chp, xfer);
881 }
882 
883 struct ata_xfer *
884 ata_get_xfer(int flags)
885 {
886 	struct ata_xfer *xfer;
887 	int s;
888 
889 	s = splbio();
890 	xfer = pool_get(&ata_xfer_pool,
891 	    ((flags & ATAXF_NOSLEEP) != 0 ? PR_NOWAIT : PR_WAITOK));
892 	splx(s);
893 	if (xfer != NULL) {
894 		memset(xfer, 0, sizeof(struct ata_xfer));
895 	}
896 	return xfer;
897 }
898 
899 void
900 ata_free_xfer(struct ata_channel *chp, struct ata_xfer *xfer)
901 {
902 	struct atac_softc *atac = chp->ch_atac;
903 	int s;
904 
905 	if (xfer->c_flags & C_WAITACT) {
906 		/* Someone is waiting for this xfer, so we can't free now */
907 		xfer->c_flags |= C_FREE;
908 		wakeup(xfer);
909 		return;
910 	}
911 
912 #if NATA_PIOBM		/* XXX wdc dependent code */
913 	if (xfer->c_flags & C_PIOBM) {
914 		struct wdc_softc *wdc = CHAN_TO_WDC(chp);
915 
916 		/* finish the busmastering PIO */
917 		(*wdc->piobm_done)(wdc->dma_arg,
918 		    chp->ch_channel, xfer->c_drive);
919 		chp->ch_flags &= ~(ATACH_DMA_WAIT | ATACH_PIOBM_WAIT | ATACH_IRQ_WAIT);
920 	}
921 #endif
922 
923 	if (atac->atac_free_hw)
924 		(*atac->atac_free_hw)(chp);
925 	s = splbio();
926 	pool_put(&ata_xfer_pool, xfer);
927 	splx(s);
928 }
929 
930 /*
931  * Kill off all pending xfers for a ata_channel.
932  *
933  * Must be called at splbio().
934  */
935 void
936 ata_kill_pending(struct ata_drive_datas *drvp)
937 {
938 	struct ata_channel *chp = drvp->chnl_softc;
939 	struct ata_xfer *xfer, *next_xfer;
940 	int s = splbio();
941 
942 	for (xfer = TAILQ_FIRST(&chp->ch_queue->queue_xfer);
943 	    xfer != NULL; xfer = next_xfer) {
944 		next_xfer = TAILQ_NEXT(xfer, c_xferchain);
945 		if (xfer->c_chp != chp || xfer->c_drive != drvp->drive)
946 			continue;
947 		TAILQ_REMOVE(&chp->ch_queue->queue_xfer, xfer, c_xferchain);
948 		(*xfer->c_kill_xfer)(chp, xfer, KILL_GONE);
949 	}
950 
951 	while ((xfer = chp->ch_queue->active_xfer) != NULL) {
952 		if (xfer->c_chp == chp && xfer->c_drive == drvp->drive) {
953 			drvp->drive_flags |= DRIVE_WAITDRAIN;
954 			(void) tsleep(&chp->ch_queue->active_xfer,
955 			    PRIBIO, "atdrn", 0);
956 		} else {
957 			/* no more xfer for us */
958 			break;
959 		}
960 	}
961 	splx(s);
962 }
963 
964 /*
965  * ata_reset_channel:
966  *
967  *	Reset and ATA channel.
968  *
969  *	MUST BE CALLED AT splbio()!
970  */
971 void
972 ata_reset_channel(struct ata_channel *chp, int flags)
973 {
974 	struct atac_softc *atac = chp->ch_atac;
975 	int drive;
976 
977 #ifdef ATA_DEBUG
978 	int spl1, spl2;
979 
980 	spl1 = splbio();
981 	spl2 = splbio();
982 	if (spl2 != spl1) {
983 		printf("ata_reset_channel: not at splbio()\n");
984 		panic("ata_reset_channel");
985 	}
986 	splx(spl2);
987 	splx(spl1);
988 #endif /* ATA_DEBUG */
989 
990 	chp->ch_queue->queue_freeze++;
991 
992 	/*
993 	 * If we can poll or wait it's OK, otherwise wake up the
994 	 * kernel thread to do it for us.
995 	 */
996 	ATADEBUG_PRINT(("ata_reset_channel flags 0x%x ch_flags 0x%x\n",
997 	    flags, chp->ch_flags), DEBUG_FUNCS | DEBUG_XFERS);
998 	if ((flags & (AT_POLL | AT_WAIT)) == 0) {
999 		if (chp->ch_flags & ATACH_TH_RESET) {
1000 			/* No need to schedule a reset more than one time. */
1001 			chp->ch_queue->queue_freeze--;
1002 			return;
1003 		}
1004 		chp->ch_flags |= ATACH_TH_RESET;
1005 		chp->ch_reset_flags = flags & (AT_RST_EMERG | AT_RST_NOCMD);
1006 		wakeup(&chp->ch_thread);
1007 		return;
1008 	}
1009 
1010 	(*atac->atac_bustype_ata->ata_reset_channel)(chp, flags);
1011 
1012 	for (drive = 0; drive < chp->ch_ndrive; drive++)
1013 		chp->ch_drive[drive].state = 0;
1014 
1015 	chp->ch_flags &= ~ATACH_TH_RESET;
1016 	if ((flags & AT_RST_EMERG) == 0)  {
1017 		chp->ch_queue->queue_freeze--;
1018 		atastart(chp);
1019 	} else {
1020 		/* make sure that we can use polled commands */
1021 		TAILQ_INIT(&chp->ch_queue->queue_xfer);
1022 		chp->ch_queue->queue_freeze = 0;
1023 		chp->ch_queue->active_xfer = NULL;
1024 	}
1025 }
1026 
1027 int
1028 ata_addref(struct ata_channel *chp)
1029 {
1030 	struct atac_softc *atac = chp->ch_atac;
1031 	struct scsipi_adapter *adapt = &atac->atac_atapi_adapter._generic;
1032 	int s, error = 0;
1033 
1034 	s = splbio();
1035 	if (adapt->adapt_refcnt++ == 0 &&
1036 	    adapt->adapt_enable != NULL) {
1037 		error = (*adapt->adapt_enable)(atac->atac_dev, 1);
1038 		if (error)
1039 			adapt->adapt_refcnt--;
1040 	}
1041 	splx(s);
1042 	return (error);
1043 }
1044 
1045 void
1046 ata_delref(struct ata_channel *chp)
1047 {
1048 	struct atac_softc *atac = chp->ch_atac;
1049 	struct scsipi_adapter *adapt = &atac->atac_atapi_adapter._generic;
1050 	int s;
1051 
1052 	s = splbio();
1053 	if (adapt->adapt_refcnt-- == 1 &&
1054 	    adapt->adapt_enable != NULL)
1055 		(void) (*adapt->adapt_enable)(atac->atac_dev, 0);
1056 	splx(s);
1057 }
1058 
1059 void
1060 ata_print_modes(struct ata_channel *chp)
1061 {
1062 	struct atac_softc *atac = chp->ch_atac;
1063 	int drive;
1064 	struct ata_drive_datas *drvp;
1065 
1066 	for (drive = 0; drive < chp->ch_ndrive; drive++) {
1067 		drvp = &chp->ch_drive[drive];
1068 		if ((drvp->drive_flags & DRIVE) == 0 || drvp->drv_softc == NULL)
1069 			continue;
1070 		aprint_verbose("%s(%s:%d:%d): using PIO mode %d",
1071 			device_xname(drvp->drv_softc),
1072 			device_xname(atac->atac_dev),
1073 			chp->ch_channel, drvp->drive, drvp->PIO_mode);
1074 #if NATA_DMA
1075 		if (drvp->drive_flags & DRIVE_DMA)
1076 			aprint_verbose(", DMA mode %d", drvp->DMA_mode);
1077 #if NATA_UDMA
1078 		if (drvp->drive_flags & DRIVE_UDMA) {
1079 			aprint_verbose(", Ultra-DMA mode %d", drvp->UDMA_mode);
1080 			if (drvp->UDMA_mode == 2)
1081 				aprint_verbose(" (Ultra/33)");
1082 			else if (drvp->UDMA_mode == 4)
1083 				aprint_verbose(" (Ultra/66)");
1084 			else if (drvp->UDMA_mode == 5)
1085 				aprint_verbose(" (Ultra/100)");
1086 			else if (drvp->UDMA_mode == 6)
1087 				aprint_verbose(" (Ultra/133)");
1088 		}
1089 #endif	/* NATA_UDMA */
1090 #endif	/* NATA_DMA */
1091 #if NATA_DMA || NATA_PIOBM
1092 		if (0
1093 #if NATA_DMA
1094 		    || (drvp->drive_flags & (DRIVE_DMA | DRIVE_UDMA))
1095 #endif
1096 #if NATA_PIOBM
1097 		    /* PIOBM capable controllers use DMA for PIO commands */
1098 		    || (atac->atac_cap & ATAC_CAP_PIOBM)
1099 #endif
1100 		    )
1101 			aprint_verbose(" (using DMA)");
1102 #endif	/* NATA_DMA || NATA_PIOBM */
1103 		aprint_verbose("\n");
1104 	}
1105 }
1106 
1107 #if NATA_DMA
1108 /*
1109  * downgrade the transfer mode of a drive after an error. return 1 if
1110  * downgrade was possible, 0 otherwise.
1111  *
1112  * MUST BE CALLED AT splbio()!
1113  */
1114 int
1115 ata_downgrade_mode(struct ata_drive_datas *drvp, int flags)
1116 {
1117 	struct ata_channel *chp = drvp->chnl_softc;
1118 	struct atac_softc *atac = chp->ch_atac;
1119 	device_t drv_dev = drvp->drv_softc;
1120 	int cf_flags = device_cfdata(drv_dev)->cf_flags;
1121 
1122 	/* if drive or controller don't know its mode, we can't do much */
1123 	if ((drvp->drive_flags & DRIVE_MODE) == 0 ||
1124 	    (atac->atac_set_modes == NULL))
1125 		return 0;
1126 	/* current drive mode was set by a config flag, let it this way */
1127 	if ((cf_flags & ATA_CONFIG_PIO_SET) ||
1128 	    (cf_flags & ATA_CONFIG_DMA_SET) ||
1129 	    (cf_flags & ATA_CONFIG_UDMA_SET))
1130 		return 0;
1131 
1132 #if NATA_UDMA
1133 	/*
1134 	 * If we were using Ultra-DMA mode, downgrade to the next lower mode.
1135 	 */
1136 	if ((drvp->drive_flags & DRIVE_UDMA) && drvp->UDMA_mode >= 2) {
1137 		drvp->UDMA_mode--;
1138 		aprint_error_dev(drv_dev,
1139 		    "transfer error, downgrading to Ultra-DMA mode %d\n",
1140 		    drvp->UDMA_mode);
1141 	}
1142 #endif
1143 
1144 	/*
1145 	 * If we were using ultra-DMA, don't downgrade to multiword DMA.
1146 	 */
1147 	else if (drvp->drive_flags & (DRIVE_DMA | DRIVE_UDMA)) {
1148 		drvp->drive_flags &= ~(DRIVE_DMA | DRIVE_UDMA);
1149 		drvp->PIO_mode = drvp->PIO_cap;
1150 		aprint_error_dev(drv_dev,
1151 		    "transfer error, downgrading to PIO mode %d\n",
1152 		    drvp->PIO_mode);
1153 	} else /* already using PIO, can't downgrade */
1154 		return 0;
1155 
1156 	(*atac->atac_set_modes)(chp);
1157 	ata_print_modes(chp);
1158 	/* reset the channel, which will schedule all drives for setup */
1159 	ata_reset_channel(chp, flags | AT_RST_NOCMD);
1160 	return 1;
1161 }
1162 #endif	/* NATA_DMA */
1163 
1164 /*
1165  * Probe drive's capabilities, for use by the controller later
1166  * Assumes drvp points to an existing drive.
1167  */
1168 void
1169 ata_probe_caps(struct ata_drive_datas *drvp)
1170 {
1171 	struct ataparams params, params2;
1172 	struct ata_channel *chp = drvp->chnl_softc;
1173 	struct atac_softc *atac = chp->ch_atac;
1174 	device_t drv_dev = drvp->drv_softc;
1175 	int i, printed, s;
1176 	const char *sep = "";
1177 	int cf_flags;
1178 
1179 	if (ata_get_params(drvp, AT_WAIT, &params) != CMD_OK) {
1180 		/* IDENTIFY failed. Can't tell more about the device */
1181 		return;
1182 	}
1183 	if ((atac->atac_cap & (ATAC_CAP_DATA16 | ATAC_CAP_DATA32)) ==
1184 	    (ATAC_CAP_DATA16 | ATAC_CAP_DATA32)) {
1185 		/*
1186 		 * Controller claims 16 and 32 bit transfers.
1187 		 * Re-do an IDENTIFY with 32-bit transfers,
1188 		 * and compare results.
1189 		 */
1190 		s = splbio();
1191 		drvp->drive_flags |= DRIVE_CAP32;
1192 		splx(s);
1193 		ata_get_params(drvp, AT_WAIT, &params2);
1194 		if (memcmp(&params, &params2, sizeof(struct ataparams)) != 0) {
1195 			/* Not good. fall back to 16bits */
1196 			s = splbio();
1197 			drvp->drive_flags &= ~DRIVE_CAP32;
1198 			splx(s);
1199 		} else {
1200 			aprint_verbose_dev(drv_dev, "32-bit data port\n");
1201 		}
1202 	}
1203 #if 0 /* Some ultra-DMA drives claims to only support ATA-3. sigh */
1204 	if (params.atap_ata_major > 0x01 &&
1205 	    params.atap_ata_major != 0xffff) {
1206 		for (i = 14; i > 0; i--) {
1207 			if (params.atap_ata_major & (1 << i)) {
1208 				aprint_verbose_dev(drv_dev,
1209 				    "ATA version %d\n", i);
1210 				drvp->ata_vers = i;
1211 				break;
1212 			}
1213 		}
1214 	}
1215 #endif
1216 
1217 	/* An ATAPI device is at last PIO mode 3 */
1218 	if (drvp->drive_flags & DRIVE_ATAPI)
1219 		drvp->PIO_mode = 3;
1220 
1221 	/*
1222 	 * It's not in the specs, but it seems that some drive
1223 	 * returns 0xffff in atap_extensions when this field is invalid
1224 	 */
1225 	if (params.atap_extensions != 0xffff &&
1226 	    (params.atap_extensions & WDC_EXT_MODES)) {
1227 		printed = 0;
1228 		/*
1229 		 * XXX some drives report something wrong here (they claim to
1230 		 * support PIO mode 8 !). As mode is coded on 3 bits in
1231 		 * SET FEATURE, limit it to 7 (so limit i to 4).
1232 		 * If higher mode than 7 is found, abort.
1233 		 */
1234 		for (i = 7; i >= 0; i--) {
1235 			if ((params.atap_piomode_supp & (1 << i)) == 0)
1236 				continue;
1237 			if (i > 4)
1238 				return;
1239 			/*
1240 			 * See if mode is accepted.
1241 			 * If the controller can't set its PIO mode,
1242 			 * assume the defaults are good, so don't try
1243 			 * to set it
1244 			 */
1245 			if (atac->atac_set_modes)
1246 				/*
1247 				 * It's OK to pool here, it's fast enough
1248 				 * to not bother waiting for interrupt
1249 				 */
1250 				if (ata_set_mode(drvp, 0x08 | (i + 3),
1251 				   AT_WAIT) != CMD_OK)
1252 					continue;
1253 			if (!printed) {
1254 				aprint_verbose_dev(drv_dev,
1255 				    "drive supports PIO mode %d", i + 3);
1256 				sep = ",";
1257 				printed = 1;
1258 			}
1259 			/*
1260 			 * If controller's driver can't set its PIO mode,
1261 			 * get the highter one for the drive.
1262 			 */
1263 			if (atac->atac_set_modes == NULL ||
1264 			    atac->atac_pio_cap >= i + 3) {
1265 				drvp->PIO_mode = i + 3;
1266 				drvp->PIO_cap = i + 3;
1267 				break;
1268 			}
1269 		}
1270 		if (!printed) {
1271 			/*
1272 			 * We didn't find a valid PIO mode.
1273 			 * Assume the values returned for DMA are buggy too
1274 			 */
1275 			return;
1276 		}
1277 		s = splbio();
1278 		drvp->drive_flags |= DRIVE_MODE;
1279 		splx(s);
1280 		printed = 0;
1281 		for (i = 7; i >= 0; i--) {
1282 			if ((params.atap_dmamode_supp & (1 << i)) == 0)
1283 				continue;
1284 #if NATA_DMA
1285 			if ((atac->atac_cap & ATAC_CAP_DMA) &&
1286 			    atac->atac_set_modes != NULL)
1287 				if (ata_set_mode(drvp, 0x20 | i, AT_WAIT)
1288 				    != CMD_OK)
1289 					continue;
1290 #endif
1291 			if (!printed) {
1292 				aprint_verbose("%s DMA mode %d", sep, i);
1293 				sep = ",";
1294 				printed = 1;
1295 			}
1296 #if NATA_DMA
1297 			if (atac->atac_cap & ATAC_CAP_DMA) {
1298 				if (atac->atac_set_modes != NULL &&
1299 				    atac->atac_dma_cap < i)
1300 					continue;
1301 				drvp->DMA_mode = i;
1302 				drvp->DMA_cap = i;
1303 				s = splbio();
1304 				drvp->drive_flags |= DRIVE_DMA;
1305 				splx(s);
1306 			}
1307 #endif
1308 			break;
1309 		}
1310 		if (params.atap_extensions & WDC_EXT_UDMA_MODES) {
1311 			printed = 0;
1312 			for (i = 7; i >= 0; i--) {
1313 				if ((params.atap_udmamode_supp & (1 << i))
1314 				    == 0)
1315 					continue;
1316 #if NATA_UDMA
1317 				if (atac->atac_set_modes != NULL &&
1318 				    (atac->atac_cap & ATAC_CAP_UDMA))
1319 					if (ata_set_mode(drvp, 0x40 | i,
1320 					    AT_WAIT) != CMD_OK)
1321 						continue;
1322 #endif
1323 				if (!printed) {
1324 					aprint_verbose("%s Ultra-DMA mode %d",
1325 					    sep, i);
1326 					if (i == 2)
1327 						aprint_verbose(" (Ultra/33)");
1328 					else if (i == 4)
1329 						aprint_verbose(" (Ultra/66)");
1330 					else if (i == 5)
1331 						aprint_verbose(" (Ultra/100)");
1332 					else if (i == 6)
1333 						aprint_verbose(" (Ultra/133)");
1334 					sep = ",";
1335 					printed = 1;
1336 				}
1337 #if NATA_UDMA
1338 				if (atac->atac_cap & ATAC_CAP_UDMA) {
1339 					if (atac->atac_set_modes != NULL &&
1340 					    atac->atac_udma_cap < i)
1341 						continue;
1342 					drvp->UDMA_mode = i;
1343 					drvp->UDMA_cap = i;
1344 					s = splbio();
1345 					drvp->drive_flags |= DRIVE_UDMA;
1346 					splx(s);
1347 				}
1348 #endif
1349 				break;
1350 			}
1351 		}
1352 		aprint_verbose("\n");
1353 	}
1354 
1355 	s = splbio();
1356 	drvp->drive_flags &= ~DRIVE_NOSTREAM;
1357 	if (drvp->drive_flags & DRIVE_ATAPI) {
1358 		if (atac->atac_cap & ATAC_CAP_ATAPI_NOSTREAM)
1359 			drvp->drive_flags |= DRIVE_NOSTREAM;
1360 	} else {
1361 		if (atac->atac_cap & ATAC_CAP_ATA_NOSTREAM)
1362 			drvp->drive_flags |= DRIVE_NOSTREAM;
1363 	}
1364 	splx(s);
1365 
1366 	/* Try to guess ATA version here, if it didn't get reported */
1367 	if (drvp->ata_vers == 0) {
1368 #if NATA_UDMA
1369 		if (drvp->drive_flags & DRIVE_UDMA)
1370 			drvp->ata_vers = 4; /* should be at last ATA-4 */
1371 		else
1372 #endif
1373 		if (drvp->PIO_cap > 2)
1374 			drvp->ata_vers = 2; /* should be at last ATA-2 */
1375 	}
1376 	cf_flags = device_cfdata(drv_dev)->cf_flags;
1377 	if (cf_flags & ATA_CONFIG_PIO_SET) {
1378 		s = splbio();
1379 		drvp->PIO_mode =
1380 		    (cf_flags & ATA_CONFIG_PIO_MODES) >> ATA_CONFIG_PIO_OFF;
1381 		drvp->drive_flags |= DRIVE_MODE;
1382 		splx(s);
1383 	}
1384 #if NATA_DMA
1385 	if ((atac->atac_cap & ATAC_CAP_DMA) == 0) {
1386 		/* don't care about DMA modes */
1387 		return;
1388 	}
1389 	if (cf_flags & ATA_CONFIG_DMA_SET) {
1390 		s = splbio();
1391 		if ((cf_flags & ATA_CONFIG_DMA_MODES) ==
1392 		    ATA_CONFIG_DMA_DISABLE) {
1393 			drvp->drive_flags &= ~DRIVE_DMA;
1394 		} else {
1395 			drvp->DMA_mode = (cf_flags & ATA_CONFIG_DMA_MODES) >>
1396 			    ATA_CONFIG_DMA_OFF;
1397 			drvp->drive_flags |= DRIVE_DMA | DRIVE_MODE;
1398 		}
1399 		splx(s);
1400 	}
1401 #if NATA_UDMA
1402 	if ((atac->atac_cap & ATAC_CAP_UDMA) == 0) {
1403 		/* don't care about UDMA modes */
1404 		return;
1405 	}
1406 	if (cf_flags & ATA_CONFIG_UDMA_SET) {
1407 		s = splbio();
1408 		if ((cf_flags & ATA_CONFIG_UDMA_MODES) ==
1409 		    ATA_CONFIG_UDMA_DISABLE) {
1410 			drvp->drive_flags &= ~DRIVE_UDMA;
1411 		} else {
1412 			drvp->UDMA_mode = (cf_flags & ATA_CONFIG_UDMA_MODES) >>
1413 			    ATA_CONFIG_UDMA_OFF;
1414 			drvp->drive_flags |= DRIVE_UDMA | DRIVE_MODE;
1415 		}
1416 		splx(s);
1417 	}
1418 #endif	/* NATA_UDMA */
1419 #endif	/* NATA_DMA */
1420 }
1421 
1422 /* management of the /dev/atabus* devices */
1423 int
1424 atabusopen(dev_t dev, int flag, int fmt, struct lwp *l)
1425 {
1426 	struct atabus_softc *sc;
1427 	int error;
1428 
1429 	sc = device_lookup_private(&atabus_cd, minor(dev));
1430 	if (sc == NULL)
1431 		return (ENXIO);
1432 
1433 	if (sc->sc_flags & ATABUSCF_OPEN)
1434 		return (EBUSY);
1435 
1436 	if ((error = ata_addref(sc->sc_chan)) != 0)
1437 		return (error);
1438 
1439 	sc->sc_flags |= ATABUSCF_OPEN;
1440 
1441 	return (0);
1442 }
1443 
1444 
1445 int
1446 atabusclose(dev_t dev, int flag, int fmt, struct lwp *l)
1447 {
1448 	struct atabus_softc *sc =
1449 	    device_lookup_private(&atabus_cd, minor(dev));
1450 
1451 	ata_delref(sc->sc_chan);
1452 
1453 	sc->sc_flags &= ~ATABUSCF_OPEN;
1454 
1455 	return (0);
1456 }
1457 
1458 int
1459 atabusioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l)
1460 {
1461 	struct atabus_softc *sc =
1462 	    device_lookup_private(&atabus_cd, minor(dev));
1463 	struct ata_channel *chp = sc->sc_chan;
1464 	int min_drive, max_drive, drive;
1465 	int error;
1466 	int s;
1467 
1468 	/*
1469 	 * Enforce write permission for ioctls that change the
1470 	 * state of the bus.  Host adapter specific ioctls must
1471 	 * be checked by the adapter driver.
1472 	 */
1473 	switch (cmd) {
1474 	case ATABUSIOSCAN:
1475 	case ATABUSIODETACH:
1476 	case ATABUSIORESET:
1477 		if ((flag & FWRITE) == 0)
1478 			return (EBADF);
1479 	}
1480 
1481 	switch (cmd) {
1482 	case ATABUSIORESET:
1483 		s = splbio();
1484 		ata_reset_channel(sc->sc_chan, AT_WAIT | AT_POLL);
1485 		splx(s);
1486 		return 0;
1487 	case ATABUSIOSCAN:
1488 	{
1489 #if 0
1490 		struct atabusioscan_args *a=
1491 		    (struct atabusioscan_args *)addr;
1492 #endif
1493 		if ((chp->ch_drive[0].drive_flags & DRIVE_OLD) ||
1494 		    (chp->ch_drive[1].drive_flags & DRIVE_OLD))
1495 			return (EOPNOTSUPP);
1496 		return (EOPNOTSUPP);
1497 	}
1498 	case ATABUSIODETACH:
1499 	{
1500 		struct atabusioscan_args *a=
1501 		    (struct atabusioscan_args *)addr;
1502 		if ((chp->ch_drive[0].drive_flags & DRIVE_OLD) ||
1503 		    (chp->ch_drive[1].drive_flags & DRIVE_OLD))
1504 			return (EOPNOTSUPP);
1505 		switch (a->at_dev) {
1506 		case -1:
1507 			min_drive = 0;
1508 			max_drive = 1;
1509 			break;
1510 		case 0:
1511 		case 1:
1512 			min_drive = max_drive = a->at_dev;
1513 			break;
1514 		default:
1515 			return (EINVAL);
1516 		}
1517 		for (drive = min_drive; drive <= max_drive; drive++) {
1518 			if (chp->ch_drive[drive].drv_softc != NULL) {
1519 				error = config_detach(
1520 				    chp->ch_drive[drive].drv_softc, 0);
1521 				if (error)
1522 					return (error);
1523 				KASSERT(chp->ch_drive[drive].drv_softc == NULL);
1524 			}
1525 		}
1526 		return 0;
1527 	}
1528 	default:
1529 		return ENOTTY;
1530 	}
1531 }
1532 
1533 static bool
1534 atabus_suspend(device_t dv, const pmf_qual_t *qual)
1535 {
1536 	struct atabus_softc *sc = device_private(dv);
1537 	struct ata_channel *chp = sc->sc_chan;
1538 
1539 	ata_queue_idle(chp->ch_queue);
1540 
1541 	return true;
1542 }
1543 
1544 static bool
1545 atabus_resume(device_t dv, const pmf_qual_t *qual)
1546 {
1547 	struct atabus_softc *sc = device_private(dv);
1548 	struct ata_channel *chp = sc->sc_chan;
1549 	int s;
1550 
1551 	/*
1552 	 * XXX joerg: with wdc, the first channel unfreezes the controler.
1553 	 * Move this the reset and queue idling into wdc.
1554 	 */
1555 	s = splbio();
1556 	if (chp->ch_queue->queue_freeze == 0) {
1557 		splx(s);
1558 		return true;
1559 	}
1560 	KASSERT(chp->ch_queue->queue_freeze > 0);
1561 	/* unfreeze the queue and reset drives */
1562 	chp->ch_queue->queue_freeze--;
1563 	ata_reset_channel(chp, AT_WAIT);
1564 	splx(s);
1565 
1566 	return true;
1567 }
1568 
1569 static int
1570 atabus_rescan(device_t self, const char *ifattr, const int *locators)
1571 {
1572 	struct atabus_softc *sc = device_private(self);
1573 	struct ata_channel *chp = sc->sc_chan;
1574 	struct atabus_initq *initq;
1575 	int i;
1576 	int s;
1577 
1578 	if (chp->atapibus != NULL) {
1579 		return EBUSY;
1580 	}
1581 
1582 	for (i = 0; i < ATA_MAXDRIVES; i++) {
1583 		if (chp->ata_drives[i] != NULL) {
1584 			return EBUSY;
1585 		}
1586 	}
1587 
1588 	s = splbio();
1589 	for (i = 0; i < ATA_MAXDRIVES; i++) {
1590 		chp->ch_drive[i].drive_flags = 0;
1591 	}
1592 	splx(s);
1593 
1594 	initq = malloc(sizeof(*initq), M_DEVBUF, M_WAITOK);
1595 	initq->atabus_sc = sc;
1596 	TAILQ_INSERT_TAIL(&atabus_initq_head, initq, atabus_initq);
1597 	config_pending_incr();
1598 
1599 	chp->ch_flags |= ATACH_TH_RESCAN;
1600 	wakeup(&chp->ch_thread);
1601 
1602 	return 0;
1603 }
1604