xref: /netbsd-src/sys/dev/ata/ata.c (revision e6c7e151de239c49d2e38720a061ed9d1fa99309)
1 /*	$NetBSD: ata.c,v 1.153 2019/10/21 18:58:57 christos 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 1.153 2019/10/21 18:58:57 christos 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/device.h>
36 #include <sys/conf.h>
37 #include <sys/fcntl.h>
38 #include <sys/proc.h>
39 #include <sys/kthread.h>
40 #include <sys/errno.h>
41 #include <sys/ataio.h>
42 #include <sys/kmem.h>
43 #include <sys/intr.h>
44 #include <sys/bus.h>
45 #include <sys/once.h>
46 #include <sys/bitops.h>
47 
48 #define ATABUS_PRIVATE
49 
50 #include <dev/ata/ataconf.h>
51 #include <dev/ata/atareg.h>
52 #include <dev/ata/atavar.h>
53 #include <dev/ic/wdcvar.h>	/* for PIOBM */
54 
55 #include "ioconf.h"
56 #include "locators.h"
57 
58 #include "atapibus.h"
59 #include "ataraid.h"
60 #include "sata_pmp.h"
61 
62 #if NATARAID > 0
63 #include <dev/ata/ata_raidvar.h>
64 #endif
65 #if NSATA_PMP > 0
66 #include <dev/ata/satapmpvar.h>
67 #endif
68 #include <dev/ata/satapmpreg.h>
69 
70 #define DEBUG_FUNCS  0x08
71 #define DEBUG_PROBE  0x10
72 #define DEBUG_DETACH 0x20
73 #define	DEBUG_XFERS  0x40
74 #ifdef ATADEBUG
75 #ifndef ATADEBUG_MASK
76 #define ATADEBUG_MASK 0
77 #endif
78 int atadebug_mask = ATADEBUG_MASK;
79 #define ATADEBUG_PRINT(args, level) \
80 	if (atadebug_mask & (level)) \
81 		printf args
82 #else
83 #define ATADEBUG_PRINT(args, level)
84 #endif
85 
86 static ONCE_DECL(ata_init_ctrl);
87 static struct pool ata_xfer_pool;
88 
89 /*
90  * A queue of atabus instances, used to ensure the same bus probe order
91  * for a given hardware configuration at each boot.  Kthread probing
92  * devices on a atabus.  Only one probing at once.
93  */
94 static TAILQ_HEAD(, atabus_initq)	atabus_initq_head;
95 static kmutex_t				atabus_qlock;
96 static kcondvar_t			atabus_qcv;
97 static lwp_t *				atabus_cfg_lwp;
98 
99 /*****************************************************************************
100  * ATA bus layer.
101  *
102  * ATA controllers attach an atabus instance, which handles probing the bus
103  * for drives, etc.
104  *****************************************************************************/
105 
106 dev_type_open(atabusopen);
107 dev_type_close(atabusclose);
108 dev_type_ioctl(atabusioctl);
109 
110 const struct cdevsw atabus_cdevsw = {
111 	.d_open = atabusopen,
112 	.d_close = atabusclose,
113 	.d_read = noread,
114 	.d_write = nowrite,
115 	.d_ioctl = atabusioctl,
116 	.d_stop = nostop,
117 	.d_tty = notty,
118 	.d_poll = nopoll,
119 	.d_mmap = nommap,
120 	.d_kqfilter = nokqfilter,
121 	.d_discard = nodiscard,
122 	.d_flag = D_OTHER
123 };
124 
125 static void atabus_childdetached(device_t, device_t);
126 static int atabus_rescan(device_t, const char *, const int *);
127 static bool atabus_resume(device_t, const pmf_qual_t *);
128 static bool atabus_suspend(device_t, const pmf_qual_t *);
129 static void atabusconfig_thread(void *);
130 
131 static void ata_channel_idle(struct ata_channel *);
132 static void ata_activate_xfer_locked(struct ata_channel *, struct ata_xfer *);
133 static void ata_channel_freeze_locked(struct ata_channel *);
134 static void ata_thread_wake_locked(struct ata_channel *);
135 
136 /*
137  * atabus_init:
138  *
139  *	Initialize ATA subsystem structures.
140  */
141 static int
142 atabus_init(void)
143 {
144 
145 	pool_init(&ata_xfer_pool, sizeof(struct ata_xfer), 0, 0, 0,
146 	    "ataspl", NULL, IPL_BIO);
147 	TAILQ_INIT(&atabus_initq_head);
148 	mutex_init(&atabus_qlock, MUTEX_DEFAULT, IPL_NONE);
149 	cv_init(&atabus_qcv, "atainitq");
150 	return 0;
151 }
152 
153 /*
154  * atabusprint:
155  *
156  *	Autoconfiguration print routine used by ATA controllers when
157  *	attaching an atabus instance.
158  */
159 int
160 atabusprint(void *aux, const char *pnp)
161 {
162 	struct ata_channel *chan = aux;
163 
164 	if (pnp)
165 		aprint_normal("atabus at %s", pnp);
166 	aprint_normal(" channel %d", chan->ch_channel);
167 
168 	return (UNCONF);
169 }
170 
171 /*
172  * ataprint:
173  *
174  *	Autoconfiguration print routine.
175  */
176 int
177 ataprint(void *aux, const char *pnp)
178 {
179 	struct ata_device *adev = aux;
180 
181 	if (pnp)
182 		aprint_normal("wd at %s", pnp);
183 	aprint_normal(" drive %d", adev->adev_drv_data->drive);
184 
185 	return (UNCONF);
186 }
187 
188 /*
189  * ata_channel_attach:
190  *
191  *	Common parts of attaching an atabus to an ATA controller channel.
192  */
193 void
194 ata_channel_attach(struct ata_channel *chp)
195 {
196 	if (chp->ch_flags & ATACH_DISABLED)
197 		return;
198 
199 	ata_channel_init(chp);
200 
201 	KASSERT(chp->ch_queue != NULL);
202 
203 	chp->atabus = config_found_ia(chp->ch_atac->atac_dev, "ata", chp,
204 		atabusprint);
205 }
206 
207 /*
208  * ata_channel_detach:
209  *
210  *	Common parts of detaching an atabus to an ATA controller channel.
211  */
212 void
213 ata_channel_detach(struct ata_channel *chp)
214 {
215 	if (chp->ch_flags & ATACH_DISABLED)
216 		return;
217 
218 	ata_channel_destroy(chp);
219 
220 	chp->ch_flags |= ATACH_DETACHED;
221 }
222 
223 static void
224 atabusconfig(struct atabus_softc *atabus_sc)
225 {
226 	struct ata_channel *chp = atabus_sc->sc_chan;
227 	struct atac_softc *atac = chp->ch_atac;
228 	struct atabus_initq *atabus_initq = NULL;
229 	int i, error;
230 
231 	/* we are in the atabus's thread context */
232 	ata_channel_lock(chp);
233 	chp->ch_flags |= ATACH_TH_RUN;
234 	ata_channel_unlock(chp);
235 
236 	/*
237 	 * Probe for the drives attached to controller, unless a PMP
238 	 * is already known
239 	 */
240 	/* XXX for SATA devices we will power up all drives at once */
241 	if (chp->ch_satapmp_nports == 0)
242 		(*atac->atac_probe)(chp);
243 
244 	if (chp->ch_ndrives >= 2) {
245 		ATADEBUG_PRINT(("atabusattach: ch_drive_type 0x%x 0x%x\n",
246 		    chp->ch_drive[0].drive_type, chp->ch_drive[1].drive_type),
247 		    DEBUG_PROBE);
248 	}
249 
250 	/* next operations will occurs in a separate thread */
251 	ata_channel_lock(chp);
252 	chp->ch_flags &= ~ATACH_TH_RUN;
253 	ata_channel_unlock(chp);
254 
255 	/* Make sure the devices probe in atabus order to avoid jitter. */
256 	mutex_enter(&atabus_qlock);
257 	for (;;) {
258 		atabus_initq = TAILQ_FIRST(&atabus_initq_head);
259 		if (atabus_initq->atabus_sc == atabus_sc)
260 			break;
261 		cv_wait(&atabus_qcv, &atabus_qlock);
262 	}
263 	mutex_exit(&atabus_qlock);
264 
265 	ata_channel_lock(chp);
266 
267 	/* If no drives, abort here */
268 	if (chp->ch_drive == NULL)
269 		goto out;
270 	KASSERT(chp->ch_ndrives == 0 || chp->ch_drive != NULL);
271 	for (i = 0; i < chp->ch_ndrives; i++)
272 		if (chp->ch_drive[i].drive_type != ATA_DRIVET_NONE)
273 			break;
274 	if (i == chp->ch_ndrives)
275 		goto out;
276 
277 	/* Shortcut in case we've been shutdown */
278 	if (chp->ch_flags & ATACH_SHUTDOWN)
279 		goto out;
280 
281 	ata_channel_unlock(chp);
282 
283 	if ((error = kthread_create(PRI_NONE, 0, NULL, atabusconfig_thread,
284 	    atabus_sc, &atabus_cfg_lwp,
285 	    "%scnf", device_xname(atac->atac_dev))) != 0)
286 		aprint_error_dev(atac->atac_dev,
287 		    "unable to create config thread: error %d\n", error);
288 	return;
289 
290  out:
291 	ata_channel_unlock(chp);
292 
293 	mutex_enter(&atabus_qlock);
294 	TAILQ_REMOVE(&atabus_initq_head, atabus_initq, atabus_initq);
295 	cv_broadcast(&atabus_qcv);
296 	mutex_exit(&atabus_qlock);
297 
298 	kmem_free(atabus_initq, sizeof(*atabus_initq));
299 
300 	ata_delref(chp);
301 
302 	config_pending_decr(atac->atac_dev);
303 }
304 
305 /*
306  * atabus_configthread: finish attach of atabus's childrens, in a separate
307  * kernel thread.
308  */
309 static void
310 atabusconfig_thread(void *arg)
311 {
312 	struct atabus_softc *atabus_sc = arg;
313 	struct ata_channel *chp = atabus_sc->sc_chan;
314 	struct atac_softc *atac = chp->ch_atac;
315 	struct atabus_initq *atabus_initq = NULL;
316 	int i, s;
317 
318 	/* XXX seems wrong */
319 	mutex_enter(&atabus_qlock);
320 	atabus_initq = TAILQ_FIRST(&atabus_initq_head);
321 	KASSERT(atabus_initq->atabus_sc == atabus_sc);
322 	mutex_exit(&atabus_qlock);
323 
324 	/*
325 	 * First look for a port multiplier
326 	 */
327 	if (chp->ch_ndrives == PMP_MAX_DRIVES &&
328 	    chp->ch_drive[PMP_PORT_CTL].drive_type == ATA_DRIVET_PM) {
329 #if NSATA_PMP > 0
330 		satapmp_attach(chp);
331 #else
332 		aprint_error_dev(atabus_sc->sc_dev,
333 		    "SATA port multiplier not supported\n");
334 		/* no problems going on, all drives are ATA_DRIVET_NONE */
335 #endif
336 	}
337 
338 	/*
339 	 * Attach an ATAPI bus, if needed.
340 	 */
341 	KASSERT(chp->ch_ndrives == 0 || chp->ch_drive != NULL);
342 	for (i = 0; i < chp->ch_ndrives && chp->atapibus == NULL; i++) {
343 		if (chp->ch_drive[i].drive_type == ATA_DRIVET_ATAPI) {
344 #if NATAPIBUS > 0
345 			(*atac->atac_atapibus_attach)(atabus_sc);
346 #else
347 			/*
348 			 * Fake the autoconfig "not configured" message
349 			 */
350 			aprint_normal("atapibus at %s not configured\n",
351 			    device_xname(atac->atac_dev));
352 			chp->atapibus = NULL;
353 			s = splbio();
354 			for (i = 0; i < chp->ch_ndrives; i++) {
355 				if (chp->ch_drive[i].drive_type == ATA_DRIVET_ATAPI)
356 					chp->ch_drive[i].drive_type = ATA_DRIVET_NONE;
357 			}
358 			splx(s);
359 #endif
360 			break;
361 		}
362 	}
363 
364 	for (i = 0; i < chp->ch_ndrives; i++) {
365 		struct ata_device adev;
366 		if (chp->ch_drive[i].drive_type != ATA_DRIVET_ATA &&
367 		    chp->ch_drive[i].drive_type != ATA_DRIVET_OLD) {
368 			continue;
369 		}
370 		if (chp->ch_drive[i].drv_softc != NULL)
371 			continue;
372 		memset(&adev, 0, sizeof(struct ata_device));
373 		adev.adev_bustype = atac->atac_bustype_ata;
374 		adev.adev_channel = chp->ch_channel;
375 		adev.adev_drv_data = &chp->ch_drive[i];
376 		chp->ch_drive[i].drv_softc = config_found_ia(atabus_sc->sc_dev,
377 		    "ata_hl", &adev, ataprint);
378 		if (chp->ch_drive[i].drv_softc != NULL) {
379 			ata_probe_caps(&chp->ch_drive[i]);
380 		} else {
381 			s = splbio();
382 			chp->ch_drive[i].drive_type = ATA_DRIVET_NONE;
383 			splx(s);
384 		}
385 	}
386 
387 	/* now that we know the drives, the controller can set its modes */
388 	if (atac->atac_set_modes) {
389 		(*atac->atac_set_modes)(chp);
390 		ata_print_modes(chp);
391 	}
392 #if NATARAID > 0
393 	if (atac->atac_cap & ATAC_CAP_RAID) {
394 		for (i = 0; i < chp->ch_ndrives; i++) {
395 			if (chp->ch_drive[i].drive_type == ATA_DRIVET_ATA) {
396 				ata_raid_check_component(
397 				    chp->ch_drive[i].drv_softc);
398 			}
399 		}
400 	}
401 #endif /* NATARAID > 0 */
402 
403 	/*
404 	 * reset drive_flags for unattached devices, reset state for attached
405 	 * ones
406 	 */
407 	s = splbio();
408 	for (i = 0; i < chp->ch_ndrives; i++) {
409 		if (chp->ch_drive[i].drive_type == ATA_DRIVET_PM)
410 			continue;
411 		if (chp->ch_drive[i].drv_softc == NULL) {
412 			chp->ch_drive[i].drive_flags = 0;
413 			chp->ch_drive[i].drive_type = ATA_DRIVET_NONE;
414 		} else
415 			chp->ch_drive[i].state = 0;
416 	}
417 	splx(s);
418 
419 	mutex_enter(&atabus_qlock);
420 	TAILQ_REMOVE(&atabus_initq_head, atabus_initq, atabus_initq);
421 	cv_broadcast(&atabus_qcv);
422 	mutex_exit(&atabus_qlock);
423 
424 	kmem_free(atabus_initq, sizeof(*atabus_initq));
425 
426 	ata_delref(chp);
427 
428 	config_pending_decr(atac->atac_dev);
429 	kthread_exit(0);
430 }
431 
432 /*
433  * atabus_thread:
434  *
435  *	Worker thread for the ATA bus.
436  */
437 static void
438 atabus_thread(void *arg)
439 {
440 	struct atabus_softc *sc = arg;
441 	struct ata_channel *chp = sc->sc_chan;
442 	struct ata_queue *chq = chp->ch_queue;
443 	struct ata_xfer *xfer;
444 	int i, rv;
445 
446 	ata_channel_lock(chp);
447 	chp->ch_flags |= ATACH_TH_RUN;
448 
449 	/*
450 	 * Probe the drives.  Reset type to indicate to controllers
451 	 * that can re-probe that all drives must be probed..
452 	 *
453 	 * Note: ch_ndrives may be changed during the probe.
454 	 */
455 	KASSERT(chp->ch_ndrives == 0 || chp->ch_drive != NULL);
456 	for (i = 0; i < chp->ch_ndrives; i++) {
457 		chp->ch_drive[i].drive_flags = 0;
458 		chp->ch_drive[i].drive_type = ATA_DRIVET_NONE;
459 	}
460 	ata_channel_unlock(chp);
461 
462 	atabusconfig(sc);
463 
464 	ata_channel_lock(chp);
465 	for (;;) {
466 		if ((chp->ch_flags & (ATACH_TH_RESET | ATACH_TH_DRIVE_RESET
467 		    | ATACH_TH_RECOVERY | ATACH_SHUTDOWN)) == 0 &&
468 		    (chq->queue_active == 0 || chq->queue_freeze == 0)) {
469 			chp->ch_flags &= ~ATACH_TH_RUN;
470 			cv_wait(&chp->ch_thr_idle, &chp->ch_lock);
471 			chp->ch_flags |= ATACH_TH_RUN;
472 		}
473 		if (chp->ch_flags & ATACH_SHUTDOWN) {
474 			break;
475 		}
476 		if (chp->ch_flags & ATACH_TH_RESCAN) {
477 			chp->ch_flags &= ~ATACH_TH_RESCAN;
478 			ata_channel_unlock(chp);
479 			atabusconfig(sc);
480 			ata_channel_lock(chp);
481 		}
482 		if (chp->ch_flags & ATACH_TH_RESET) {
483 			/* this will unfreeze the channel */
484 			ata_thread_run(chp, AT_WAIT,
485 			    ATACH_TH_RESET, ATACH_NODRIVE);
486 		} else if (chp->ch_flags & ATACH_TH_DRIVE_RESET) {
487 			/* this will unfreeze the channel */
488 			for (i = 0; i < chp->ch_ndrives; i++) {
489 				struct ata_drive_datas *drvp;
490 
491 				drvp = &chp->ch_drive[i];
492 
493 				if (drvp->drive_flags & ATA_DRIVE_TH_RESET) {
494 					ata_thread_run(chp,
495 					    AT_WAIT, ATACH_TH_DRIVE_RESET, i);
496 				}
497 			}
498 			chp->ch_flags &= ~ATACH_TH_DRIVE_RESET;
499 		} else if (chp->ch_flags & ATACH_TH_RECOVERY) {
500 			/*
501 			 * This will unfreeze the channel; drops locks during
502 			 * run, so must wrap in splbio()/splx() to avoid
503 			 * spurious interrupts. XXX MPSAFE
504 			 */
505 			int s = splbio();
506 			ata_thread_run(chp, AT_WAIT, ATACH_TH_RECOVERY,
507 			    chp->recovery_tfd);
508 			splx(s);
509 		} else if (chq->queue_active > 0 && chq->queue_freeze == 1) {
510 			/*
511 			 * Caller has bumped queue_freeze, decrease it. This
512 			 * flow shalt never be executed for NCQ commands.
513 			 */
514 			KASSERT((chp->ch_flags & ATACH_NCQ) == 0);
515 			KASSERT(chq->queue_active == 1);
516 
517 			ata_channel_thaw_locked(chp);
518 			xfer = ata_queue_get_active_xfer_locked(chp);
519 
520 			KASSERT(xfer != NULL);
521 			KASSERT((xfer->c_flags & C_POLL) == 0);
522 
523 			switch ((rv = ata_xfer_start(xfer))) {
524 			case ATASTART_STARTED:
525 			case ATASTART_POLL:
526 			case ATASTART_ABORT:
527 				break;
528 			case ATASTART_TH:
529 			default:
530 				panic("%s: ata_xfer_start() unexpected rv %d",
531 				    __func__, rv);
532 				/* NOTREACHED */
533 			}
534 		} else if (chq->queue_freeze > 1)
535 			panic("%s: queue_freeze", __func__);
536 
537 		/* Try to run down the queue once channel is unfrozen */
538 		if (chq->queue_freeze == 0) {
539 			ata_channel_unlock(chp);
540 			atastart(chp);
541 			ata_channel_lock(chp);
542 		}
543 	}
544 	chp->ch_thread = NULL;
545 	cv_signal(&chp->ch_thr_idle);
546 	ata_channel_unlock(chp);
547 	kthread_exit(0);
548 }
549 
550 static void
551 ata_thread_wake_locked(struct ata_channel *chp)
552 {
553 	KASSERT(mutex_owned(&chp->ch_lock));
554 	ata_channel_freeze_locked(chp);
555 	cv_signal(&chp->ch_thr_idle);
556 }
557 
558 /*
559  * atabus_match:
560  *
561  *	Autoconfiguration match routine.
562  */
563 static int
564 atabus_match(device_t parent, cfdata_t cf, void *aux)
565 {
566 	struct ata_channel *chp = aux;
567 
568 	if (chp == NULL)
569 		return (0);
570 
571 	if (cf->cf_loc[ATACF_CHANNEL] != chp->ch_channel &&
572 	    cf->cf_loc[ATACF_CHANNEL] != ATACF_CHANNEL_DEFAULT)
573 		return (0);
574 
575 	return (1);
576 }
577 
578 /*
579  * atabus_attach:
580  *
581  *	Autoconfiguration attach routine.
582  */
583 static void
584 atabus_attach(device_t parent, device_t self, void *aux)
585 {
586 	struct atabus_softc *sc = device_private(self);
587 	struct ata_channel *chp = aux;
588 	struct atabus_initq *initq;
589 	int error;
590 
591 	sc->sc_chan = chp;
592 
593 	aprint_normal("\n");
594 	aprint_naive("\n");
595 
596 	sc->sc_dev = self;
597 
598 	if (ata_addref(chp))
599 		return;
600 
601 	RUN_ONCE(&ata_init_ctrl, atabus_init);
602 
603 	initq = kmem_zalloc(sizeof(*initq), KM_SLEEP);
604 	initq->atabus_sc = sc;
605 	mutex_enter(&atabus_qlock);
606 	TAILQ_INSERT_TAIL(&atabus_initq_head, initq, atabus_initq);
607 	mutex_exit(&atabus_qlock);
608 	config_pending_incr(sc->sc_dev);
609 
610 	/* XXX MPSAFE - no KTHREAD_MPSAFE, so protected by KERNEL_LOCK() */
611 	if ((error = kthread_create(PRI_NONE, 0, NULL, atabus_thread, sc,
612 	    &chp->ch_thread, "%s", device_xname(self))) != 0)
613 		aprint_error_dev(self,
614 		    "unable to create kernel thread: error %d\n", error);
615 
616 	if (!pmf_device_register(self, atabus_suspend, atabus_resume))
617 		aprint_error_dev(self, "couldn't establish power handler\n");
618 }
619 
620 /*
621  * atabus_detach:
622  *
623  *	Autoconfiguration detach routine.
624  */
625 static int
626 atabus_detach(device_t self, int flags)
627 {
628 	struct atabus_softc *sc = device_private(self);
629 	struct ata_channel *chp = sc->sc_chan;
630 	device_t dev = NULL;
631 	int i, error = 0;
632 
633 	/*
634 	 * Detach atapibus and its children.
635 	 */
636 	if ((dev = chp->atapibus) != NULL) {
637 		ATADEBUG_PRINT(("atabus_detach: %s: detaching %s\n",
638 		    device_xname(self), device_xname(dev)), DEBUG_DETACH);
639 
640 		error = config_detach(dev, flags);
641 		if (error)
642 			goto out;
643 		KASSERT(chp->atapibus == NULL);
644 	}
645 
646 	KASSERT(chp->ch_ndrives == 0 || chp->ch_drive != NULL);
647 
648 	/*
649 	 * Detach our other children.
650 	 */
651 	for (i = 0; i < chp->ch_ndrives; i++) {
652 		if (chp->ch_drive[i].drive_type == ATA_DRIVET_ATAPI)
653 			continue;
654 		if (chp->ch_drive[i].drive_type == ATA_DRIVET_PM)
655 			chp->ch_drive[i].drive_type = ATA_DRIVET_NONE;
656 		if ((dev = chp->ch_drive[i].drv_softc) != NULL) {
657 			ATADEBUG_PRINT(("%s.%d: %s: detaching %s\n", __func__,
658 			    __LINE__, device_xname(self), device_xname(dev)),
659 			    DEBUG_DETACH);
660 			error = config_detach(dev, flags);
661 			if (error)
662 				goto out;
663 			KASSERT(chp->ch_drive[i].drv_softc == NULL);
664 			KASSERT(chp->ch_drive[i].drive_type == 0);
665 		}
666 	}
667 
668 	/* Shutdown the channel. */
669 	ata_channel_lock(chp);
670 	chp->ch_flags |= ATACH_SHUTDOWN;
671 	while (chp->ch_thread != NULL) {
672 		cv_signal(&chp->ch_thr_idle);
673 		cv_wait(&chp->ch_thr_idle, &chp->ch_lock);
674 	}
675 	ata_channel_unlock(chp);
676 
677 	atabus_free_drives(chp);
678 
679  out:
680 #ifdef ATADEBUG
681 	if (dev != NULL && error != 0)
682 		ATADEBUG_PRINT(("%s: %s: error %d detaching %s\n", __func__,
683 		    device_xname(self), error, device_xname(dev)),
684 		    DEBUG_DETACH);
685 #endif /* ATADEBUG */
686 
687 	return (error);
688 }
689 
690 void
691 atabus_childdetached(device_t self, device_t child)
692 {
693 	bool found = false;
694 	struct atabus_softc *sc = device_private(self);
695 	struct ata_channel *chp = sc->sc_chan;
696 	int i;
697 
698 	KASSERT(chp->ch_ndrives == 0 || chp->ch_drive != NULL);
699 	/*
700 	 * atapibus detached.
701 	 */
702 	if (child == chp->atapibus) {
703 		chp->atapibus = NULL;
704 		found = true;
705 		for (i = 0; i < chp->ch_ndrives; i++) {
706 			if (chp->ch_drive[i].drive_type != ATA_DRIVET_ATAPI)
707 				continue;
708 			KASSERT(chp->ch_drive[i].drv_softc != NULL);
709 			chp->ch_drive[i].drv_softc = NULL;
710 			chp->ch_drive[i].drive_flags = 0;
711 			chp->ch_drive[i].drive_type = ATA_DRIVET_NONE;
712 		}
713 	}
714 
715 	/*
716 	 * Detach our other children.
717 	 */
718 	for (i = 0; i < chp->ch_ndrives; i++) {
719 		if (chp->ch_drive[i].drive_type == ATA_DRIVET_ATAPI)
720 			continue;
721 		if (child == chp->ch_drive[i].drv_softc) {
722 			chp->ch_drive[i].drv_softc = NULL;
723 			chp->ch_drive[i].drive_flags = 0;
724 			if (chp->ch_drive[i].drive_type == ATA_DRIVET_PM)
725 				chp->ch_satapmp_nports = 0;
726 			chp->ch_drive[i].drive_type = ATA_DRIVET_NONE;
727 			found = true;
728 		}
729 	}
730 
731 	if (!found)
732 		panic("%s: unknown child %p", device_xname(self),
733 		    (const void *)child);
734 }
735 
736 CFATTACH_DECL3_NEW(atabus, sizeof(struct atabus_softc),
737     atabus_match, atabus_attach, atabus_detach, NULL, atabus_rescan,
738     atabus_childdetached, DVF_DETACH_SHUTDOWN);
739 
740 /*****************************************************************************
741  * Common ATA bus operations.
742  *****************************************************************************/
743 
744 /* allocate/free the channel's ch_drive[] array */
745 int
746 atabus_alloc_drives(struct ata_channel *chp, int ndrives)
747 {
748 	int i;
749 	if (chp->ch_ndrives != ndrives)
750 		atabus_free_drives(chp);
751 	if (chp->ch_drive == NULL) {
752 		void *drv;
753 
754 		ata_channel_unlock(chp);
755 		drv = kmem_zalloc(sizeof(*chp->ch_drive) * ndrives, KM_SLEEP);
756 		ata_channel_lock(chp);
757 
758 		if (chp->ch_drive != NULL) {
759 			/* lost the race */
760 			kmem_free(drv, sizeof(*chp->ch_drive) * ndrives);
761 			return 0;
762 		}
763 		chp->ch_drive = drv;
764 	}
765 	for (i = 0; i < ndrives; i++) {
766 		chp->ch_drive[i].chnl_softc = chp;
767 		chp->ch_drive[i].drive = i;
768 	}
769 	chp->ch_ndrives = ndrives;
770 	return 0;
771 }
772 
773 void
774 atabus_free_drives(struct ata_channel *chp)
775 {
776 #ifdef DIAGNOSTIC
777 	int i;
778 	int dopanic = 0;
779 	KASSERT(chp->ch_ndrives == 0 || chp->ch_drive != NULL);
780 	for (i = 0; i < chp->ch_ndrives; i++) {
781 		if (chp->ch_drive[i].drive_type != ATA_DRIVET_NONE) {
782 			printf("%s: ch_drive[%d] type %d != ATA_DRIVET_NONE\n",
783 			    device_xname(chp->atabus), i,
784 			    chp->ch_drive[i].drive_type);
785 			dopanic = 1;
786 		}
787 		if (chp->ch_drive[i].drv_softc != NULL) {
788 			printf("%s: ch_drive[%d] attached to %s\n",
789 			    device_xname(chp->atabus), i,
790 			    device_xname(chp->ch_drive[i].drv_softc));
791 			dopanic = 1;
792 		}
793 	}
794 	if (dopanic)
795 		panic("atabus_free_drives");
796 #endif
797 
798 	if (chp->ch_drive == NULL)
799 		return;
800 	kmem_free(chp->ch_drive,
801 	    sizeof(struct ata_drive_datas) * chp->ch_ndrives);
802 	chp->ch_ndrives = 0;
803 	chp->ch_drive = NULL;
804 }
805 
806 /* Get the disk's parameters */
807 int
808 ata_get_params(struct ata_drive_datas *drvp, uint8_t flags,
809     struct ataparams *prms)
810 {
811 	struct ata_xfer *xfer;
812 	struct ata_channel *chp = drvp->chnl_softc;
813 	struct atac_softc *atac = chp->ch_atac;
814 	char *tb;
815 	int i, rv;
816 	uint16_t *p;
817 
818 	ATADEBUG_PRINT(("%s\n", __func__), DEBUG_FUNCS);
819 
820 	xfer = ata_get_xfer(chp, false);
821 	if (xfer == NULL) {
822 		ATADEBUG_PRINT(("%s: no xfer\n", __func__),
823 		    DEBUG_FUNCS|DEBUG_PROBE);
824 		return CMD_AGAIN;
825 	}
826 
827 	tb = kmem_zalloc(ATA_BSIZE, KM_SLEEP);
828 	memset(prms, 0, sizeof(struct ataparams));
829 
830 	if (drvp->drive_type == ATA_DRIVET_ATA) {
831 		xfer->c_ata_c.r_command = WDCC_IDENTIFY;
832 		xfer->c_ata_c.r_st_bmask = WDCS_DRDY;
833 		xfer->c_ata_c.r_st_pmask = WDCS_DRQ;
834 		xfer->c_ata_c.timeout = 3000; /* 3s */
835 	} else if (drvp->drive_type == ATA_DRIVET_ATAPI) {
836 		xfer->c_ata_c.r_command = ATAPI_IDENTIFY_DEVICE;
837 		xfer->c_ata_c.r_st_bmask = 0;
838 		xfer->c_ata_c.r_st_pmask = WDCS_DRQ;
839 		xfer->c_ata_c.timeout = 10000; /* 10s */
840 	} else {
841 		ATADEBUG_PRINT(("ata_get_parms: no disks\n"),
842 		    DEBUG_FUNCS|DEBUG_PROBE);
843 		rv = CMD_ERR;
844 		goto out;
845 	}
846 	xfer->c_ata_c.flags = AT_READ | flags;
847 	xfer->c_ata_c.data = tb;
848 	xfer->c_ata_c.bcount = ATA_BSIZE;
849 	if ((*atac->atac_bustype_ata->ata_exec_command)(drvp,
850 						xfer) != ATACMD_COMPLETE) {
851 		ATADEBUG_PRINT(("ata_get_parms: wdc_exec_command failed\n"),
852 		    DEBUG_FUNCS|DEBUG_PROBE);
853 		rv = CMD_AGAIN;
854 		goto out;
855 	}
856 	if (xfer->c_ata_c.flags & (AT_ERROR | AT_TIMEOU | AT_DF)) {
857 		ATADEBUG_PRINT(("ata_get_parms: ata_c.flags=0x%x\n",
858 		    xfer->c_ata_c.flags), DEBUG_FUNCS|DEBUG_PROBE);
859 		rv = CMD_ERR;
860 		goto out;
861 	}
862 	/* if we didn't read any data something is wrong */
863 	if ((xfer->c_ata_c.flags & AT_XFDONE) == 0) {
864 		rv = CMD_ERR;
865 		goto out;
866 	}
867 
868 	/* Read in parameter block. */
869 	memcpy(prms, tb, sizeof(struct ataparams));
870 
871 	/*
872 	 * Shuffle string byte order.
873 	 * ATAPI NEC, Mitsumi and Pioneer drives and
874 	 * old ATA TDK CompactFlash cards
875 	 * have different byte order.
876 	 */
877 #if BYTE_ORDER == BIG_ENDIAN
878 # define M(n)	prms->atap_model[(n) ^ 1]
879 #else
880 # define M(n)	prms->atap_model[n]
881 #endif
882 	if (
883 #if BYTE_ORDER == BIG_ENDIAN
884 	    !
885 #endif
886 	    ((drvp->drive_type == ATA_DRIVET_ATAPI) ?
887 	     ((M(0) == 'N' && M(1) == 'E') ||
888 	      (M(0) == 'F' && M(1) == 'X') ||
889 	      (M(0) == 'P' && M(1) == 'i')) :
890 	     ((M(0) == 'T' && M(1) == 'D' && M(2) == 'K')))) {
891 		rv = CMD_OK;
892 		goto out;
893 	     }
894 #undef M
895 	for (i = 0; i < sizeof(prms->atap_model); i += 2) {
896 		p = (uint16_t *)(prms->atap_model + i);
897 		*p = bswap16(*p);
898 	}
899 	for (i = 0; i < sizeof(prms->atap_serial); i += 2) {
900 		p = (uint16_t *)(prms->atap_serial + i);
901 		*p = bswap16(*p);
902 	}
903 	for (i = 0; i < sizeof(prms->atap_revision); i += 2) {
904 		p = (uint16_t *)(prms->atap_revision + i);
905 		*p = bswap16(*p);
906 	}
907 
908 	rv = CMD_OK;
909  out:
910 	kmem_free(tb, ATA_BSIZE);
911 	ata_free_xfer(chp, xfer);
912 	return rv;
913 }
914 
915 int
916 ata_set_mode(struct ata_drive_datas *drvp, uint8_t mode, uint8_t flags)
917 {
918 	struct ata_xfer *xfer;
919 	int rv;
920 	struct ata_channel *chp = drvp->chnl_softc;
921 	struct atac_softc *atac = chp->ch_atac;
922 
923 	ATADEBUG_PRINT(("ata_set_mode=0x%x\n", mode), DEBUG_FUNCS);
924 
925 	xfer = ata_get_xfer(chp, false);
926 	if (xfer == NULL) {
927 		ATADEBUG_PRINT(("%s: no xfer\n", __func__),
928 		    DEBUG_FUNCS|DEBUG_PROBE);
929 		return CMD_AGAIN;
930 	}
931 
932 	xfer->c_ata_c.r_command = SET_FEATURES;
933 	xfer->c_ata_c.r_st_bmask = 0;
934 	xfer->c_ata_c.r_st_pmask = 0;
935 	xfer->c_ata_c.r_features = WDSF_SET_MODE;
936 	xfer->c_ata_c.r_count = mode;
937 	xfer->c_ata_c.flags = flags;
938 	xfer->c_ata_c.timeout = 1000; /* 1s */
939 	if ((*atac->atac_bustype_ata->ata_exec_command)(drvp,
940 						xfer) != ATACMD_COMPLETE) {
941 		rv = CMD_AGAIN;
942 		goto out;
943 	}
944 	if (xfer->c_ata_c.flags & (AT_ERROR | AT_TIMEOU | AT_DF)) {
945 		rv = CMD_ERR;
946 		goto out;
947 	}
948 
949 	rv = CMD_OK;
950 
951 out:
952 	ata_free_xfer(chp, xfer);
953 	return rv;
954 }
955 
956 #if NATA_DMA
957 void
958 ata_dmaerr(struct ata_drive_datas *drvp, int flags)
959 {
960 	ata_channel_lock_owned(drvp->chnl_softc);
961 
962 	/*
963 	 * Downgrade decision: if we get NERRS_MAX in NXFER.
964 	 * We start with n_dmaerrs set to NERRS_MAX-1 so that the
965 	 * first error within the first NXFER ops will immediatly trigger
966 	 * a downgrade.
967 	 * If we got an error and n_xfers is bigger than NXFER reset counters.
968 	 */
969 	drvp->n_dmaerrs++;
970 	if (drvp->n_dmaerrs >= NERRS_MAX && drvp->n_xfers <= NXFER) {
971 		ata_downgrade_mode(drvp, flags);
972 		drvp->n_dmaerrs = NERRS_MAX-1;
973 		drvp->n_xfers = 0;
974 		return;
975 	}
976 	if (drvp->n_xfers > NXFER) {
977 		drvp->n_dmaerrs = 1; /* just got an error */
978 		drvp->n_xfers = 1; /* restart counting from this error */
979 	}
980 }
981 #endif	/* NATA_DMA */
982 
983 /*
984  * freeze the queue and wait for the controller to be idle. Caller has to
985  * unfreeze/restart the queue
986  */
987 static void
988 ata_channel_idle(struct ata_channel *chp)
989 {
990 	ata_channel_lock(chp);
991 	ata_channel_freeze_locked(chp);
992 	while (chp->ch_queue->queue_active > 0) {
993 		chp->ch_queue->queue_flags |= QF_IDLE_WAIT;
994 		cv_timedwait(&chp->ch_queue->queue_idle, &chp->ch_lock, 1);
995 	}
996 	ata_channel_unlock(chp);
997 }
998 
999 /*
1000  * Add a command to the queue and start controller.
1001  *
1002  * MUST BE CALLED AT splbio()!
1003  */
1004 void
1005 ata_exec_xfer(struct ata_channel *chp, struct ata_xfer *xfer)
1006 {
1007 
1008 	ATADEBUG_PRINT(("ata_exec_xfer %p channel %d drive %d\n", xfer,
1009 	    chp->ch_channel, xfer->c_drive), DEBUG_XFERS);
1010 
1011 	/* complete xfer setup */
1012 	xfer->c_chp = chp;
1013 
1014 	ata_channel_lock(chp);
1015 
1016 	/*
1017 	 * Standard commands are added to the end of command list, but
1018 	 * recovery commands must be run immediatelly.
1019 	 */
1020 	if ((xfer->c_flags & C_SKIP_QUEUE) == 0)
1021 		SIMPLEQ_INSERT_TAIL(&chp->ch_queue->queue_xfer, xfer,
1022 		    c_xferchain);
1023 	else
1024 		SIMPLEQ_INSERT_HEAD(&chp->ch_queue->queue_xfer, xfer,
1025 		    c_xferchain);
1026 
1027 	/*
1028 	 * if polling and can sleep, wait for the xfer to be at head of queue
1029 	 */
1030 	if ((xfer->c_flags & (C_POLL | C_WAIT)) ==  (C_POLL | C_WAIT)) {
1031 		while (chp->ch_queue->queue_active > 0 ||
1032 		    SIMPLEQ_FIRST(&chp->ch_queue->queue_xfer) != xfer) {
1033 			xfer->c_flags |= C_WAITACT;
1034 			cv_wait(&chp->ch_queue->c_active, &chp->ch_lock);
1035 			xfer->c_flags &= ~C_WAITACT;
1036 		}
1037 
1038 		/*
1039 		 * Free xfer now if it there was attempt to free it
1040 		 * while we were waiting.
1041 		 */
1042 		if ((xfer->c_flags & (C_FREE|C_WAITTIMO)) == C_FREE) {
1043 			ata_channel_unlock(chp);
1044 
1045 			ata_free_xfer(chp, xfer);
1046 			return;
1047 		}
1048 	}
1049 
1050 	ata_channel_unlock(chp);
1051 
1052 	ATADEBUG_PRINT(("atastart from ata_exec_xfer, flags 0x%x\n",
1053 	    chp->ch_flags), DEBUG_XFERS);
1054 	atastart(chp);
1055 }
1056 
1057 /*
1058  * Start I/O on a controller, for the given channel.
1059  * The first xfer may be not for our channel if the channel queues
1060  * are shared.
1061  *
1062  * MUST BE CALLED AT splbio()!
1063  *
1064  * XXX FIS-based switching with PMP
1065  * Currently atastart() never schedules concurrent NCQ transfers to more than
1066  * one drive, even when channel has several SATA drives attached via PMP.
1067  * To support concurrent transfers to different drives with PMP, it would be
1068  * necessary to implement FIS-based switching support in controller driver,
1069  * and then adjust error handling and recovery to stop assuming at most
1070  * one active drive.
1071  */
1072 void
1073 atastart(struct ata_channel *chp)
1074 {
1075 	struct atac_softc *atac = chp->ch_atac;
1076 	struct ata_queue *chq = chp->ch_queue;
1077 	struct ata_xfer *xfer, *axfer;
1078 	bool skipq;
1079 
1080 #ifdef ATA_DEBUG
1081 	int spl1, spl2;
1082 
1083 	spl1 = splbio();
1084 	spl2 = splbio();
1085 	if (spl2 != spl1) {
1086 		printf("atastart: not at splbio()\n");
1087 		panic("atastart");
1088 	}
1089 	splx(spl2);
1090 	splx(spl1);
1091 #endif /* ATA_DEBUG */
1092 
1093 	ata_channel_lock(chp);
1094 
1095 again:
1096 	/* is there a xfer ? */
1097 	if ((xfer = SIMPLEQ_FIRST(&chp->ch_queue->queue_xfer)) == NULL) {
1098 		ATADEBUG_PRINT(("%s(chp=%p): channel %d queue_xfer is empty\n",
1099 		    __func__, chp, chp->ch_channel), DEBUG_XFERS);
1100 		goto out;
1101 	}
1102 
1103 	/*
1104 	 * if someone is waiting for the command to be active, wake it up
1105 	 * and let it process the command
1106 	 */
1107 	if (__predict_false(xfer->c_flags & C_WAITACT)) {
1108 		ATADEBUG_PRINT(("atastart: xfer %p channel %d drive %d "
1109 		    "wait active\n", xfer, chp->ch_channel, xfer->c_drive),
1110 		    DEBUG_XFERS);
1111 		cv_broadcast(&chp->ch_queue->c_active);
1112 		goto out;
1113 	}
1114 
1115 	skipq = ISSET(xfer->c_flags, C_SKIP_QUEUE);
1116 
1117 	/* is the queue frozen? */
1118 	if (__predict_false(!skipq && chq->queue_freeze > 0)) {
1119 		if (chq->queue_flags & QF_IDLE_WAIT) {
1120 			chq->queue_flags &= ~QF_IDLE_WAIT;
1121 			cv_signal(&chp->ch_queue->queue_idle);
1122 		}
1123 		ATADEBUG_PRINT(("%s(chp=%p): channel %d drive %d "
1124 		    "queue frozen: %d\n",
1125 		    __func__, chp, chp->ch_channel, xfer->c_drive,
1126 		    chq->queue_freeze),
1127 		    DEBUG_XFERS);
1128 		goto out;
1129 	}
1130 
1131 	/* all xfers on same queue must belong to the same channel */
1132 	KASSERT(xfer->c_chp == chp);
1133 
1134 	/*
1135 	 * Can only take the command if there are no current active
1136 	 * commands, or if the command is NCQ and the active commands are also
1137 	 * NCQ. If PM is in use and HBA driver doesn't support/use FIS-based
1138 	 * switching, can only send commands to single drive.
1139 	 * Need only check first xfer.
1140 	 * XXX FIS-based switching - revisit
1141 	 */
1142 	if (!skipq && (axfer = TAILQ_FIRST(&chp->ch_queue->active_xfers))) {
1143 		if (!ISSET(xfer->c_flags, C_NCQ) ||
1144 		    !ISSET(axfer->c_flags, C_NCQ) ||
1145 		    xfer->c_drive != axfer->c_drive)
1146 			goto out;
1147 	}
1148 
1149 	struct ata_drive_datas * const drvp = &chp->ch_drive[xfer->c_drive];
1150 
1151 	/*
1152 	 * Are we on limit of active xfers ? If the queue has more
1153 	 * than 1 openings, we keep one slot reserved for recovery or dump.
1154 	 */
1155 	KASSERT(chq->queue_active <= chq->queue_openings);
1156 	const uint8_t chq_openings = (!skipq && chq->queue_openings > 1)
1157 	    ? (chq->queue_openings - 1) : chq->queue_openings;
1158 	const uint8_t drv_openings = ISSET(xfer->c_flags, C_NCQ)
1159 	    ? drvp->drv_openings : ATA_MAX_OPENINGS;
1160 	if (chq->queue_active >= MIN(chq_openings, drv_openings)) {
1161 		if (skipq) {
1162 			panic("%s: channel %d busy, xfer not possible",
1163 			    __func__, chp->ch_channel);
1164 		}
1165 
1166 		ATADEBUG_PRINT(("%s(chp=%p): channel %d completely busy\n",
1167 		    __func__, chp, chp->ch_channel), DEBUG_XFERS);
1168 		goto out;
1169 	}
1170 
1171 	/* Slot allocation can fail if drv_openings < ch_openings */
1172 	if (!ata_queue_alloc_slot(chp, &xfer->c_slot, drv_openings))
1173 		goto out;
1174 
1175 	if (__predict_false(atac->atac_claim_hw)) {
1176 		if (!atac->atac_claim_hw(chp, 0)) {
1177 			ata_queue_free_slot(chp, xfer->c_slot);
1178 			goto out;
1179 		}
1180 	}
1181 
1182 	/* Now committed to start the xfer */
1183 
1184 	ATADEBUG_PRINT(("%s(chp=%p): xfer %p channel %d drive %d\n",
1185 	    __func__, chp, xfer, chp->ch_channel, xfer->c_drive), DEBUG_XFERS);
1186 	if (drvp->drive_flags & ATA_DRIVE_RESET) {
1187 		drvp->drive_flags &= ~ATA_DRIVE_RESET;
1188 		drvp->state = 0;
1189 	}
1190 
1191 	if (ISSET(xfer->c_flags, C_NCQ))
1192 		SET(chp->ch_flags, ATACH_NCQ);
1193 	else
1194 		CLR(chp->ch_flags, ATACH_NCQ);
1195 
1196 	SIMPLEQ_REMOVE_HEAD(&chq->queue_xfer, c_xferchain);
1197 
1198 	ata_activate_xfer_locked(chp, xfer);
1199 
1200 	if (atac->atac_cap & ATAC_CAP_NOIRQ)
1201 		KASSERT(xfer->c_flags & C_POLL);
1202 
1203 	switch (ata_xfer_start(xfer)) {
1204 	case ATASTART_TH:
1205 	case ATASTART_ABORT:
1206 		/* don't start any further commands in this case */
1207 		goto out;
1208 	default:
1209 		/* nothing to do */
1210 		break;
1211 	}
1212 
1213 	/* Queue more commands if possible, but not during recovery or dump */
1214 	if (!skipq && chq->queue_active < chq->queue_openings)
1215 		goto again;
1216 
1217 out:
1218 	ata_channel_unlock(chp);
1219 }
1220 
1221 int
1222 ata_xfer_start(struct ata_xfer *xfer)
1223 {
1224 	struct ata_channel *chp = xfer->c_chp;
1225 	int rv;
1226 
1227 	KASSERT(mutex_owned(&chp->ch_lock));
1228 
1229 	rv = xfer->ops->c_start(chp, xfer);
1230 	switch (rv) {
1231 	case ATASTART_STARTED:
1232 		/* nothing to do */
1233 		break;
1234 	case ATASTART_TH:
1235 		/* postpone xfer to thread */
1236 		ata_thread_wake_locked(chp);
1237 		break;
1238 	case ATASTART_POLL:
1239 		/* can happen even in thread context for some ATAPI devices */
1240 		ata_channel_unlock(chp);
1241 		KASSERT(xfer->ops != NULL && xfer->ops->c_poll != NULL);
1242 		xfer->ops->c_poll(chp, xfer);
1243 		ata_channel_lock(chp);
1244 		break;
1245 	case ATASTART_ABORT:
1246 		ata_channel_unlock(chp);
1247 		KASSERT(xfer->ops != NULL && xfer->ops->c_abort != NULL);
1248 		xfer->ops->c_abort(chp, xfer);
1249 		ata_channel_lock(chp);
1250 		break;
1251 	}
1252 
1253 	return rv;
1254 }
1255 
1256 static void
1257 ata_activate_xfer_locked(struct ata_channel *chp, struct ata_xfer *xfer)
1258 {
1259 	struct ata_queue * const chq = chp->ch_queue;
1260 
1261 	KASSERT(mutex_owned(&chp->ch_lock));
1262 	KASSERT((chq->active_xfers_used & __BIT(xfer->c_slot)) == 0);
1263 
1264 	if ((xfer->c_flags & C_SKIP_QUEUE) == 0)
1265 		TAILQ_INSERT_TAIL(&chq->active_xfers, xfer, c_activechain);
1266 	else {
1267 		/*
1268 		 * Must go to head, so that ata_queue_get_active_xfer()
1269 		 * returns the recovery command, and not some other
1270 		 * random active transfer.
1271 		 */
1272 		TAILQ_INSERT_HEAD(&chq->active_xfers, xfer, c_activechain);
1273 	}
1274 	chq->active_xfers_used |= __BIT(xfer->c_slot);
1275 	chq->queue_active++;
1276 }
1277 
1278 /*
1279  * Does it's own locking, does not require splbio().
1280  * flags - whether to block waiting for free xfer
1281  */
1282 struct ata_xfer *
1283 ata_get_xfer(struct ata_channel *chp, bool waitok)
1284 {
1285 	return pool_get(&ata_xfer_pool,
1286 	    PR_ZERO | (waitok ? PR_WAITOK : PR_NOWAIT));
1287 }
1288 
1289 /*
1290  * ata_deactivate_xfer() must be always called prior to ata_free_xfer()
1291  */
1292 void
1293 ata_free_xfer(struct ata_channel *chp, struct ata_xfer *xfer)
1294 {
1295 	struct ata_queue *chq = chp->ch_queue;
1296 
1297 	ata_channel_lock(chp);
1298 
1299 	if (__predict_false(xfer->c_flags & (C_WAITACT|C_WAITTIMO))) {
1300 		/* Someone is waiting for this xfer, so we can't free now */
1301 		xfer->c_flags |= C_FREE;
1302 		cv_broadcast(&chq->c_active);
1303 		ata_channel_unlock(chp);
1304 		return;
1305 	}
1306 
1307 	/* XXX move PIOBM and free_gw to deactivate? */
1308 #if NATA_PIOBM		/* XXX wdc dependent code */
1309 	if (__predict_false(xfer->c_flags & C_PIOBM)) {
1310 		struct wdc_softc *wdc = CHAN_TO_WDC(chp);
1311 
1312 		/* finish the busmastering PIO */
1313 		(*wdc->piobm_done)(wdc->dma_arg,
1314 		    chp->ch_channel, xfer->c_drive);
1315 		chp->ch_flags &= ~(ATACH_DMA_WAIT | ATACH_PIOBM_WAIT | ATACH_IRQ_WAIT);
1316 	}
1317 #endif
1318 
1319 	if (__predict_false(chp->ch_atac->atac_free_hw))
1320 		chp->ch_atac->atac_free_hw(chp);
1321 
1322 	ata_channel_unlock(chp);
1323 
1324 	if (__predict_true(!ISSET(xfer->c_flags, C_PRIVATE_ALLOC)))
1325 		pool_put(&ata_xfer_pool, xfer);
1326 }
1327 
1328 void
1329 ata_deactivate_xfer(struct ata_channel *chp, struct ata_xfer *xfer)
1330 {
1331 	struct ata_queue * const chq = chp->ch_queue;
1332 
1333 	ata_channel_lock(chp);
1334 
1335 	KASSERT(chq->queue_active > 0);
1336 	KASSERT((chq->active_xfers_used & __BIT(xfer->c_slot)) != 0);
1337 
1338 	/* Stop only when this is last active xfer */
1339 	if (chq->queue_active == 1)
1340 		callout_stop(&chp->c_timo_callout);
1341 
1342 	if (callout_invoking(&chp->c_timo_callout))
1343 		xfer->c_flags |= C_WAITTIMO;
1344 
1345 	TAILQ_REMOVE(&chq->active_xfers, xfer, c_activechain);
1346 	chq->active_xfers_used &= ~__BIT(xfer->c_slot);
1347 	chq->queue_active--;
1348 
1349 	ata_queue_free_slot(chp, xfer->c_slot);
1350 
1351 	if (xfer->c_flags & C_WAIT)
1352 		cv_broadcast(&chq->c_cmd_finish);
1353 
1354 	ata_channel_unlock(chp);
1355 }
1356 
1357 /*
1358  * Called in c_intr hook. Must be called before before any deactivations
1359  * are done - if there is drain pending, it calls c_kill_xfer hook which
1360  * deactivates the xfer.
1361  * Calls c_kill_xfer with channel lock free.
1362  * Returns true if caller should just exit without further processing.
1363  * Caller must not further access any part of xfer or any related controller
1364  * structures in that case, it should just return.
1365  */
1366 bool
1367 ata_waitdrain_xfer_check(struct ata_channel *chp, struct ata_xfer *xfer)
1368 {
1369 	int drive = xfer->c_drive;
1370 	bool draining = false;
1371 
1372 	ata_channel_lock(chp);
1373 
1374 	if (chp->ch_drive[drive].drive_flags & ATA_DRIVE_WAITDRAIN) {
1375 		ata_channel_unlock(chp);
1376 
1377 		xfer->ops->c_kill_xfer(chp, xfer, KILL_GONE);
1378 
1379 		ata_channel_lock(chp);
1380 		chp->ch_drive[drive].drive_flags &= ~ATA_DRIVE_WAITDRAIN;
1381 		cv_signal(&chp->ch_queue->queue_drain);
1382 		draining = true;
1383 	}
1384 
1385 	ata_channel_unlock(chp);
1386 
1387 	return draining;
1388 }
1389 
1390 /*
1391  * Check for race of normal transfer handling vs. timeout.
1392  */
1393 bool
1394 ata_timo_xfer_check(struct ata_xfer *xfer)
1395 {
1396 	struct ata_channel *chp = xfer->c_chp;
1397 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->c_drive];
1398 
1399 	ata_channel_lock(chp);
1400 
1401 	if (xfer->c_flags & C_WAITTIMO) {
1402 		xfer->c_flags &= ~C_WAITTIMO;
1403 
1404 		/* Handle race vs. ata_free_xfer() */
1405 		if (xfer->c_flags & C_FREE) {
1406 			xfer->c_flags &= ~C_FREE;
1407 			ata_channel_unlock(chp);
1408 
1409 	    		device_printf(drvp->drv_softc,
1410 			    "xfer %"PRIxPTR" freed while invoking timeout\n",
1411 			    (intptr_t)xfer & PAGE_MASK);
1412 
1413 			ata_free_xfer(chp, xfer);
1414 			return true;
1415 		}
1416 
1417 		/* Race vs. callout_stop() in ata_deactivate_xfer() */
1418 		ata_channel_unlock(chp);
1419 
1420 	    	device_printf(drvp->drv_softc,
1421 		    "xfer %"PRIxPTR" deactivated while invoking timeout\n",
1422 		    (intptr_t)xfer & PAGE_MASK);
1423 		return true;
1424 	}
1425 
1426 	ata_channel_unlock(chp);
1427 
1428 	/* No race, proceed with timeout handling */
1429 	return false;
1430 }
1431 
1432 /*
1433  * Kill off all active xfers for a ata_channel.
1434  *
1435  * Must be called with channel lock held.
1436  */
1437 void
1438 ata_kill_active(struct ata_channel *chp, int reason, int flags)
1439 {
1440 	struct ata_queue * const chq = chp->ch_queue;
1441 	struct ata_xfer *xfer, *xfernext;
1442 
1443 	KASSERT(mutex_owned(&chp->ch_lock));
1444 
1445 	TAILQ_FOREACH_SAFE(xfer, &chq->active_xfers, c_activechain, xfernext) {
1446 		ata_channel_unlock(chp);
1447 		xfer->ops->c_kill_xfer(xfer->c_chp, xfer, reason);
1448 		ata_channel_lock(chp);
1449 	}
1450 }
1451 
1452 /*
1453  * Kill off all pending xfers for a drive.
1454  */
1455 void
1456 ata_kill_pending(struct ata_drive_datas *drvp)
1457 {
1458 	struct ata_channel * const chp = drvp->chnl_softc;
1459 	struct ata_queue * const chq = chp->ch_queue;
1460 	struct ata_xfer *xfer;
1461 
1462 	ata_channel_lock(chp);
1463 
1464 	/* Kill all pending transfers */
1465 	while ((xfer = SIMPLEQ_FIRST(&chq->queue_xfer))) {
1466 		KASSERT(xfer->c_chp == chp);
1467 
1468 		if (xfer->c_drive != drvp->drive)
1469 			continue;
1470 
1471 		SIMPLEQ_REMOVE_HEAD(&chp->ch_queue->queue_xfer, c_xferchain);
1472 
1473 		/*
1474 		 * Keep the lock, so that we get deadlock (and 'locking against
1475 		 * myself' with LOCKDEBUG), instead of silent
1476 		 * data corruption, if the hook tries to call back into
1477 		 * middle layer for inactive xfer.
1478 		 */
1479 		xfer->ops->c_kill_xfer(chp, xfer, KILL_GONE_INACTIVE);
1480 	}
1481 
1482 	/* Wait until all active transfers on the drive finish */
1483 	while (chq->queue_active > 0) {
1484 		bool drv_active = false;
1485 
1486 		TAILQ_FOREACH(xfer, &chq->active_xfers, c_activechain) {
1487 			KASSERT(xfer->c_chp == chp);
1488 
1489 			if (xfer->c_drive == drvp->drive) {
1490 				drv_active = true;
1491 				break;
1492 			}
1493 		}
1494 
1495 		if (!drv_active) {
1496 			/* all finished */
1497 			break;
1498 		}
1499 
1500 		drvp->drive_flags |= ATA_DRIVE_WAITDRAIN;
1501 		cv_wait(&chq->queue_drain, &chp->ch_lock);
1502 	}
1503 
1504 	ata_channel_unlock(chp);
1505 }
1506 
1507 static void
1508 ata_channel_freeze_locked(struct ata_channel *chp)
1509 {
1510 	chp->ch_queue->queue_freeze++;
1511 
1512 	ATADEBUG_PRINT(("%s(chp=%p) -> %d\n", __func__, chp,
1513 	    chp->ch_queue->queue_freeze), DEBUG_FUNCS | DEBUG_XFERS);
1514 }
1515 
1516 void
1517 ata_channel_freeze(struct ata_channel *chp)
1518 {
1519 	ata_channel_lock(chp);
1520 	ata_channel_freeze_locked(chp);
1521 	ata_channel_unlock(chp);
1522 }
1523 
1524 void
1525 ata_channel_thaw_locked(struct ata_channel *chp)
1526 {
1527 	KASSERT(mutex_owned(&chp->ch_lock));
1528 	KASSERT(chp->ch_queue->queue_freeze > 0);
1529 
1530 	chp->ch_queue->queue_freeze--;
1531 
1532 	ATADEBUG_PRINT(("%s(chp=%p) -> %d\n", __func__, chp,
1533 	    chp->ch_queue->queue_freeze), DEBUG_FUNCS | DEBUG_XFERS);
1534 }
1535 
1536 /*
1537  * ata_thread_run:
1538  *
1539  *	Reset and ATA channel. Channel lock must be held. arg is type-specific.
1540  */
1541 void
1542 ata_thread_run(struct ata_channel *chp, int flags, int type, int arg)
1543 {
1544 	struct atac_softc *atac = chp->ch_atac;
1545 	bool threset = false;
1546 	struct ata_drive_datas *drvp;
1547 
1548 	ata_channel_lock_owned(chp);
1549 
1550 	/*
1551 	 * If we can poll or wait it's OK, otherwise wake up the
1552 	 * kernel thread to do it for us.
1553 	 */
1554 	ATADEBUG_PRINT(("%s flags 0x%x ch_flags 0x%x\n",
1555 	    __func__, flags, chp->ch_flags), DEBUG_FUNCS | DEBUG_XFERS);
1556 	if ((flags & (AT_POLL | AT_WAIT)) == 0) {
1557 		switch (type) {
1558 		case ATACH_TH_RESET:
1559 			if (chp->ch_flags & ATACH_TH_RESET) {
1560 				/* No need to schedule another reset */
1561 				return;
1562 			}
1563 			break;
1564 		case ATACH_TH_DRIVE_RESET:
1565 		    {
1566 			int drive = arg;
1567 
1568 			KASSERT(drive <= chp->ch_ndrives);
1569 			drvp = &chp->ch_drive[drive];
1570 
1571 			if (drvp->drive_flags & ATA_DRIVE_TH_RESET) {
1572 				/* No need to schedule another reset */
1573 				return;
1574 			}
1575 			drvp->drive_flags |= ATA_DRIVE_TH_RESET;
1576 			break;
1577 		    }
1578 		case ATACH_TH_RECOVERY:
1579 		    {
1580 			uint32_t tfd = (uint32_t)arg;
1581 
1582 			KASSERT((chp->ch_flags & ATACH_RECOVERING) == 0);
1583 			chp->recovery_tfd = tfd;
1584 			break;
1585 		    }
1586 		default:
1587 			panic("%s: unknown type: %x", __func__, type);
1588 			/* NOTREACHED */
1589 		}
1590 
1591 		/*
1592 		 * Block execution of other commands while reset is scheduled
1593 		 * to a thread.
1594 		 */
1595 		ata_channel_freeze_locked(chp);
1596 		chp->ch_flags |= type;
1597 
1598 		cv_signal(&chp->ch_thr_idle);
1599 		return;
1600 	}
1601 
1602 	/* Block execution of other commands during reset */
1603 	ata_channel_freeze_locked(chp);
1604 
1605 	/*
1606 	 * If reset has been scheduled to a thread, then clear
1607 	 * the flag now so that the thread won't try to execute it if
1608 	 * we happen to sleep, and thaw one more time after the reset.
1609 	 */
1610 	if (chp->ch_flags & type) {
1611 		chp->ch_flags &= ~type;
1612 		threset = true;
1613 	}
1614 
1615 	switch (type) {
1616 	case ATACH_TH_RESET:
1617 		(*atac->atac_bustype_ata->ata_reset_channel)(chp, flags);
1618 
1619 		KASSERT(chp->ch_ndrives == 0 || chp->ch_drive != NULL);
1620 		for (int drive = 0; drive < chp->ch_ndrives; drive++)
1621 			chp->ch_drive[drive].state = 0;
1622 		break;
1623 
1624 	case ATACH_TH_DRIVE_RESET:
1625 	    {
1626 		int drive = arg;
1627 
1628 		KASSERT(drive <= chp->ch_ndrives);
1629 		drvp = &chp->ch_drive[drive];
1630 		(*atac->atac_bustype_ata->ata_reset_drive)(drvp, flags, NULL);
1631 		drvp->state = 0;
1632 		break;
1633 	    }
1634 
1635 	case ATACH_TH_RECOVERY:
1636 	    {
1637 		uint32_t tfd = (uint32_t)arg;
1638 
1639 		KASSERT((chp->ch_flags & ATACH_RECOVERING) == 0);
1640 		KASSERT(atac->atac_bustype_ata->ata_recovery != NULL);
1641 
1642 		SET(chp->ch_flags, ATACH_RECOVERING);
1643 		(*atac->atac_bustype_ata->ata_recovery)(chp, flags, tfd);
1644 		CLR(chp->ch_flags, ATACH_RECOVERING);
1645 		break;
1646 	    }
1647 
1648 	default:
1649 		panic("%s: unknown type: %x", __func__, type);
1650 		/* NOTREACHED */
1651 	}
1652 
1653 	/*
1654 	 * Thaw one extra time to clear the freeze done when the reset has
1655 	 * been scheduled to the thread.
1656 	 */
1657 	if (threset)
1658 		ata_channel_thaw_locked(chp);
1659 
1660 	/* Allow commands to run again */
1661 	ata_channel_thaw_locked(chp);
1662 
1663 	/* Signal the thread in case there is an xfer to run */
1664 	cv_signal(&chp->ch_thr_idle);
1665 }
1666 
1667 int
1668 ata_addref(struct ata_channel *chp)
1669 {
1670 	struct atac_softc *atac = chp->ch_atac;
1671 	struct scsipi_adapter *adapt = &atac->atac_atapi_adapter._generic;
1672 	int s, error = 0;
1673 
1674 	s = splbio();
1675 	if (adapt->adapt_refcnt++ == 0 &&
1676 	    adapt->adapt_enable != NULL) {
1677 		error = (*adapt->adapt_enable)(atac->atac_dev, 1);
1678 		if (error)
1679 			adapt->adapt_refcnt--;
1680 	}
1681 	splx(s);
1682 	return (error);
1683 }
1684 
1685 void
1686 ata_delref(struct ata_channel *chp)
1687 {
1688 	struct atac_softc *atac = chp->ch_atac;
1689 	struct scsipi_adapter *adapt = &atac->atac_atapi_adapter._generic;
1690 	int s;
1691 
1692 	s = splbio();
1693 	if (adapt->adapt_refcnt-- == 1 &&
1694 	    adapt->adapt_enable != NULL)
1695 		(void) (*adapt->adapt_enable)(atac->atac_dev, 0);
1696 	splx(s);
1697 }
1698 
1699 void
1700 ata_print_modes(struct ata_channel *chp)
1701 {
1702 	struct atac_softc *atac = chp->ch_atac;
1703 	int drive;
1704 	struct ata_drive_datas *drvp;
1705 
1706 	KASSERT(chp->ch_ndrives == 0 || chp->ch_drive != NULL);
1707 	for (drive = 0; drive < chp->ch_ndrives; drive++) {
1708 		drvp = &chp->ch_drive[drive];
1709 		if (drvp->drive_type == ATA_DRIVET_NONE ||
1710 		    drvp->drv_softc == NULL)
1711 			continue;
1712 		aprint_verbose("%s(%s:%d:%d): using PIO mode %d",
1713 			device_xname(drvp->drv_softc),
1714 			device_xname(atac->atac_dev),
1715 			chp->ch_channel, drvp->drive, drvp->PIO_mode);
1716 #if NATA_DMA
1717 		if (drvp->drive_flags & ATA_DRIVE_DMA)
1718 			aprint_verbose(", DMA mode %d", drvp->DMA_mode);
1719 #if NATA_UDMA
1720 		if (drvp->drive_flags & ATA_DRIVE_UDMA) {
1721 			aprint_verbose(", Ultra-DMA mode %d", drvp->UDMA_mode);
1722 			if (drvp->UDMA_mode == 2)
1723 				aprint_verbose(" (Ultra/33)");
1724 			else if (drvp->UDMA_mode == 4)
1725 				aprint_verbose(" (Ultra/66)");
1726 			else if (drvp->UDMA_mode == 5)
1727 				aprint_verbose(" (Ultra/100)");
1728 			else if (drvp->UDMA_mode == 6)
1729 				aprint_verbose(" (Ultra/133)");
1730 		}
1731 #endif	/* NATA_UDMA */
1732 #endif	/* NATA_DMA */
1733 #if NATA_DMA || NATA_PIOBM
1734 		if (0
1735 #if NATA_DMA
1736 		    || (drvp->drive_flags & (ATA_DRIVE_DMA | ATA_DRIVE_UDMA))
1737 #endif
1738 #if NATA_PIOBM
1739 		    /* PIOBM capable controllers use DMA for PIO commands */
1740 		    || (atac->atac_cap & ATAC_CAP_PIOBM)
1741 #endif
1742 		    )
1743 			aprint_verbose(" (using DMA)");
1744 
1745 		if (drvp->drive_flags & ATA_DRIVE_NCQ) {
1746 			aprint_verbose(", NCQ (%d tags)%s",
1747 			    ATA_REAL_OPENINGS(chp->ch_queue->queue_openings),
1748 			    (drvp->drive_flags & ATA_DRIVE_NCQ_PRIO)
1749 			    ? " w/PRIO" : "");
1750 		} else if (drvp->drive_flags & ATA_DRIVE_WFUA)
1751 			aprint_verbose(", WRITE DMA FUA EXT");
1752 
1753 #endif	/* NATA_DMA || NATA_PIOBM */
1754 		aprint_verbose("\n");
1755 	}
1756 }
1757 
1758 #if NATA_DMA
1759 /*
1760  * downgrade the transfer mode of a drive after an error. return 1 if
1761  * downgrade was possible, 0 otherwise.
1762  *
1763  * MUST BE CALLED AT splbio()!
1764  */
1765 int
1766 ata_downgrade_mode(struct ata_drive_datas *drvp, int flags)
1767 {
1768 	struct ata_channel *chp = drvp->chnl_softc;
1769 	struct atac_softc *atac = chp->ch_atac;
1770 	device_t drv_dev = drvp->drv_softc;
1771 	int cf_flags = device_cfdata(drv_dev)->cf_flags;
1772 
1773 	ata_channel_lock_owned(drvp->chnl_softc);
1774 
1775 	/* if drive or controller don't know its mode, we can't do much */
1776 	if ((drvp->drive_flags & ATA_DRIVE_MODE) == 0 ||
1777 	    (atac->atac_set_modes == NULL))
1778 		return 0;
1779 	/* current drive mode was set by a config flag, let it this way */
1780 	if ((cf_flags & ATA_CONFIG_PIO_SET) ||
1781 	    (cf_flags & ATA_CONFIG_DMA_SET) ||
1782 	    (cf_flags & ATA_CONFIG_UDMA_SET))
1783 		return 0;
1784 
1785 #if NATA_UDMA
1786 	/*
1787 	 * If we were using Ultra-DMA mode, downgrade to the next lower mode.
1788 	 */
1789 	if ((drvp->drive_flags & ATA_DRIVE_UDMA) && drvp->UDMA_mode >= 2) {
1790 		drvp->UDMA_mode--;
1791 		aprint_error_dev(drv_dev,
1792 		    "transfer error, downgrading to Ultra-DMA mode %d\n",
1793 		    drvp->UDMA_mode);
1794 	}
1795 #endif
1796 
1797 	/*
1798 	 * If we were using ultra-DMA, don't downgrade to multiword DMA.
1799 	 */
1800 	else if (drvp->drive_flags & (ATA_DRIVE_DMA | ATA_DRIVE_UDMA)) {
1801 		drvp->drive_flags &= ~(ATA_DRIVE_DMA | ATA_DRIVE_UDMA);
1802 		drvp->PIO_mode = drvp->PIO_cap;
1803 		aprint_error_dev(drv_dev,
1804 		    "transfer error, downgrading to PIO mode %d\n",
1805 		    drvp->PIO_mode);
1806 	} else /* already using PIO, can't downgrade */
1807 		return 0;
1808 
1809 	(*atac->atac_set_modes)(chp);
1810 	ata_print_modes(chp);
1811 	/* reset the channel, which will schedule all drives for setup */
1812 	ata_thread_run(chp, flags, ATACH_TH_RESET, ATACH_NODRIVE);
1813 	return 1;
1814 }
1815 #endif	/* NATA_DMA */
1816 
1817 /*
1818  * Probe drive's capabilities, for use by the controller later
1819  * Assumes drvp points to an existing drive.
1820  */
1821 void
1822 ata_probe_caps(struct ata_drive_datas *drvp)
1823 {
1824 	struct ataparams params, params2;
1825 	struct ata_channel *chp = drvp->chnl_softc;
1826 	struct atac_softc *atac = chp->ch_atac;
1827 	device_t drv_dev = drvp->drv_softc;
1828 	int i, printed = 0;
1829 	const char *sep = "";
1830 	int cf_flags;
1831 
1832 	if (ata_get_params(drvp, AT_WAIT, &params) != CMD_OK) {
1833 		/* IDENTIFY failed. Can't tell more about the device */
1834 		return;
1835 	}
1836 	if ((atac->atac_cap & (ATAC_CAP_DATA16 | ATAC_CAP_DATA32)) ==
1837 	    (ATAC_CAP_DATA16 | ATAC_CAP_DATA32)) {
1838 		/*
1839 		 * Controller claims 16 and 32 bit transfers.
1840 		 * Re-do an IDENTIFY with 32-bit transfers,
1841 		 * and compare results.
1842 		 */
1843 		ata_channel_lock(chp);
1844 		drvp->drive_flags |= ATA_DRIVE_CAP32;
1845 		ata_channel_unlock(chp);
1846 		ata_get_params(drvp, AT_WAIT, &params2);
1847 		if (memcmp(&params, &params2, sizeof(struct ataparams)) != 0) {
1848 			/* Not good. fall back to 16bits */
1849 			ata_channel_lock(chp);
1850 			drvp->drive_flags &= ~ATA_DRIVE_CAP32;
1851 			ata_channel_unlock(chp);
1852 		} else {
1853 			aprint_verbose_dev(drv_dev, "32-bit data port\n");
1854 		}
1855 	}
1856 #if 0 /* Some ultra-DMA drives claims to only support ATA-3. sigh */
1857 	if (params.atap_ata_major > 0x01 &&
1858 	    params.atap_ata_major != 0xffff) {
1859 		for (i = 14; i > 0; i--) {
1860 			if (params.atap_ata_major & (1 << i)) {
1861 				aprint_verbose_dev(drv_dev,
1862 				    "ATA version %d\n", i);
1863 				drvp->ata_vers = i;
1864 				break;
1865 			}
1866 		}
1867 	}
1868 #endif
1869 
1870 	/* An ATAPI device is at last PIO mode 3 */
1871 	if (drvp->drive_type == ATA_DRIVET_ATAPI)
1872 		drvp->PIO_mode = 3;
1873 
1874 	/*
1875 	 * It's not in the specs, but it seems that some drive
1876 	 * returns 0xffff in atap_extensions when this field is invalid
1877 	 */
1878 	if (params.atap_extensions != 0xffff &&
1879 	    (params.atap_extensions & WDC_EXT_MODES)) {
1880 		/*
1881 		 * XXX some drives report something wrong here (they claim to
1882 		 * support PIO mode 8 !). As mode is coded on 3 bits in
1883 		 * SET FEATURE, limit it to 7 (so limit i to 4).
1884 		 * If higher mode than 7 is found, abort.
1885 		 */
1886 		for (i = 7; i >= 0; i--) {
1887 			if ((params.atap_piomode_supp & (1 << i)) == 0)
1888 				continue;
1889 			if (i > 4)
1890 				return;
1891 			/*
1892 			 * See if mode is accepted.
1893 			 * If the controller can't set its PIO mode,
1894 			 * assume the defaults are good, so don't try
1895 			 * to set it
1896 			 */
1897 			if (atac->atac_set_modes)
1898 				/*
1899 				 * It's OK to pool here, it's fast enough
1900 				 * to not bother waiting for interrupt
1901 				 */
1902 				if (ata_set_mode(drvp, 0x08 | (i + 3),
1903 				   AT_WAIT) != CMD_OK)
1904 					continue;
1905 			if (!printed) {
1906 				aprint_verbose_dev(drv_dev,
1907 				    "drive supports PIO mode %d", i + 3);
1908 				sep = ",";
1909 				printed = 1;
1910 			}
1911 			/*
1912 			 * If controller's driver can't set its PIO mode,
1913 			 * get the highter one for the drive.
1914 			 */
1915 			if (atac->atac_set_modes == NULL ||
1916 			    atac->atac_pio_cap >= i + 3) {
1917 				drvp->PIO_mode = i + 3;
1918 				drvp->PIO_cap = i + 3;
1919 				break;
1920 			}
1921 		}
1922 		if (!printed) {
1923 			/*
1924 			 * We didn't find a valid PIO mode.
1925 			 * Assume the values returned for DMA are buggy too
1926 			 */
1927 			return;
1928 		}
1929 		ata_channel_lock(chp);
1930 		drvp->drive_flags |= ATA_DRIVE_MODE;
1931 		ata_channel_unlock(chp);
1932 		printed = 0;
1933 		for (i = 7; i >= 0; i--) {
1934 			if ((params.atap_dmamode_supp & (1 << i)) == 0)
1935 				continue;
1936 #if NATA_DMA
1937 			if ((atac->atac_cap & ATAC_CAP_DMA) &&
1938 			    atac->atac_set_modes != NULL)
1939 				if (ata_set_mode(drvp, 0x20 | i, AT_WAIT)
1940 				    != CMD_OK)
1941 					continue;
1942 #endif
1943 			if (!printed) {
1944 				aprint_verbose("%s DMA mode %d", sep, i);
1945 				sep = ",";
1946 				printed = 1;
1947 			}
1948 #if NATA_DMA
1949 			if (atac->atac_cap & ATAC_CAP_DMA) {
1950 				if (atac->atac_set_modes != NULL &&
1951 				    atac->atac_dma_cap < i)
1952 					continue;
1953 				drvp->DMA_mode = i;
1954 				drvp->DMA_cap = i;
1955 				ata_channel_lock(chp);
1956 				drvp->drive_flags |= ATA_DRIVE_DMA;
1957 				ata_channel_unlock(chp);
1958 			}
1959 #endif
1960 			break;
1961 		}
1962 		if (params.atap_extensions & WDC_EXT_UDMA_MODES) {
1963 			printed = 0;
1964 			for (i = 7; i >= 0; i--) {
1965 				if ((params.atap_udmamode_supp & (1 << i))
1966 				    == 0)
1967 					continue;
1968 #if NATA_UDMA
1969 				if (atac->atac_set_modes != NULL &&
1970 				    (atac->atac_cap & ATAC_CAP_UDMA))
1971 					if (ata_set_mode(drvp, 0x40 | i,
1972 					    AT_WAIT) != CMD_OK)
1973 						continue;
1974 #endif
1975 				if (!printed) {
1976 					aprint_verbose("%s Ultra-DMA mode %d",
1977 					    sep, i);
1978 					if (i == 2)
1979 						aprint_verbose(" (Ultra/33)");
1980 					else if (i == 4)
1981 						aprint_verbose(" (Ultra/66)");
1982 					else if (i == 5)
1983 						aprint_verbose(" (Ultra/100)");
1984 					else if (i == 6)
1985 						aprint_verbose(" (Ultra/133)");
1986 					sep = ",";
1987 					printed = 1;
1988 				}
1989 #if NATA_UDMA
1990 				if (atac->atac_cap & ATAC_CAP_UDMA) {
1991 					if (atac->atac_set_modes != NULL &&
1992 					    atac->atac_udma_cap < i)
1993 						continue;
1994 					drvp->UDMA_mode = i;
1995 					drvp->UDMA_cap = i;
1996 					ata_channel_lock(chp);
1997 					drvp->drive_flags |= ATA_DRIVE_UDMA;
1998 					ata_channel_unlock(chp);
1999 				}
2000 #endif
2001 				break;
2002 			}
2003 		}
2004 	}
2005 
2006 	ata_channel_lock(chp);
2007 	drvp->drive_flags &= ~ATA_DRIVE_NOSTREAM;
2008 	if (drvp->drive_type == ATA_DRIVET_ATAPI) {
2009 		if (atac->atac_cap & ATAC_CAP_ATAPI_NOSTREAM)
2010 			drvp->drive_flags |= ATA_DRIVE_NOSTREAM;
2011 	} else {
2012 		if (atac->atac_cap & ATAC_CAP_ATA_NOSTREAM)
2013 			drvp->drive_flags |= ATA_DRIVE_NOSTREAM;
2014 	}
2015 	ata_channel_unlock(chp);
2016 
2017 	/* Try to guess ATA version here, if it didn't get reported */
2018 	if (drvp->ata_vers == 0) {
2019 #if NATA_UDMA
2020 		if (drvp->drive_flags & ATA_DRIVE_UDMA)
2021 			drvp->ata_vers = 4; /* should be at last ATA-4 */
2022 		else
2023 #endif
2024 		if (drvp->PIO_cap > 2)
2025 			drvp->ata_vers = 2; /* should be at last ATA-2 */
2026 	}
2027 	cf_flags = device_cfdata(drv_dev)->cf_flags;
2028 	if (cf_flags & ATA_CONFIG_PIO_SET) {
2029 		ata_channel_lock(chp);
2030 		drvp->PIO_mode =
2031 		    (cf_flags & ATA_CONFIG_PIO_MODES) >> ATA_CONFIG_PIO_OFF;
2032 		drvp->drive_flags |= ATA_DRIVE_MODE;
2033 		ata_channel_unlock(chp);
2034 	}
2035 #if NATA_DMA
2036 	if ((atac->atac_cap & ATAC_CAP_DMA) == 0) {
2037 		/* don't care about DMA modes */
2038 		if (*sep != '\0')
2039 			aprint_verbose("\n");
2040 		return;
2041 	}
2042 	if (cf_flags & ATA_CONFIG_DMA_SET) {
2043 		ata_channel_lock(chp);
2044 		if ((cf_flags & ATA_CONFIG_DMA_MODES) ==
2045 		    ATA_CONFIG_DMA_DISABLE) {
2046 			drvp->drive_flags &= ~ATA_DRIVE_DMA;
2047 		} else {
2048 			drvp->DMA_mode = (cf_flags & ATA_CONFIG_DMA_MODES) >>
2049 			    ATA_CONFIG_DMA_OFF;
2050 			drvp->drive_flags |= ATA_DRIVE_DMA | ATA_DRIVE_MODE;
2051 		}
2052 		ata_channel_unlock(chp);
2053 	}
2054 
2055 	/*
2056 	 * Probe WRITE DMA FUA EXT. Support is mandatory for devices
2057 	 * supporting LBA48, but nevertheless confirm with the feature flag.
2058 	 */
2059 	if (drvp->drive_flags & ATA_DRIVE_DMA) {
2060 		if ((params.atap_cmd2_en & ATA_CMD2_LBA48) != 0
2061 		    && (params.atap_cmd_def & ATA_CMDE_WFE)) {
2062 			drvp->drive_flags |= ATA_DRIVE_WFUA;
2063 			aprint_verbose("%s WRITE DMA FUA", sep);
2064 			sep = ",";
2065 		}
2066 	}
2067 
2068 	/* Probe NCQ support - READ/WRITE FPDMA QUEUED command support */
2069 	ata_channel_lock(chp);
2070 	drvp->drv_openings = 1;
2071 	if (params.atap_sata_caps & SATA_NATIVE_CMDQ) {
2072 		if (atac->atac_cap & ATAC_CAP_NCQ)
2073 			drvp->drive_flags |= ATA_DRIVE_NCQ;
2074 		drvp->drv_openings =
2075 		    (params.atap_queuedepth & WDC_QUEUE_DEPTH_MASK) + 1;
2076 		aprint_verbose("%s NCQ (%d tags)", sep, drvp->drv_openings);
2077 		sep = ",";
2078 
2079 		if (params.atap_sata_caps & SATA_NCQ_PRIO) {
2080 			drvp->drive_flags |= ATA_DRIVE_NCQ_PRIO;
2081 			aprint_verbose(" w/PRIO");
2082 		}
2083 	}
2084 	ata_channel_unlock(chp);
2085 
2086 	if (*sep != '\0')
2087 		aprint_verbose("\n");
2088 
2089 #if NATA_UDMA
2090 	if ((atac->atac_cap & ATAC_CAP_UDMA) == 0) {
2091 		/* don't care about UDMA modes */
2092 		return;
2093 	}
2094 	if (cf_flags & ATA_CONFIG_UDMA_SET) {
2095 		ata_channel_lock(chp);
2096 		if ((cf_flags & ATA_CONFIG_UDMA_MODES) ==
2097 		    ATA_CONFIG_UDMA_DISABLE) {
2098 			drvp->drive_flags &= ~ATA_DRIVE_UDMA;
2099 		} else {
2100 			drvp->UDMA_mode = (cf_flags & ATA_CONFIG_UDMA_MODES) >>
2101 			    ATA_CONFIG_UDMA_OFF;
2102 			drvp->drive_flags |= ATA_DRIVE_UDMA | ATA_DRIVE_MODE;
2103 		}
2104 		ata_channel_unlock(chp);
2105 	}
2106 #endif	/* NATA_UDMA */
2107 #endif	/* NATA_DMA */
2108 }
2109 
2110 /* management of the /dev/atabus* devices */
2111 int
2112 atabusopen(dev_t dev, int flag, int fmt, struct lwp *l)
2113 {
2114 	struct atabus_softc *sc;
2115 	int error;
2116 
2117 	sc = device_lookup_private(&atabus_cd, minor(dev));
2118 	if (sc == NULL)
2119 		return (ENXIO);
2120 
2121 	if (sc->sc_flags & ATABUSCF_OPEN)
2122 		return (EBUSY);
2123 
2124 	if ((error = ata_addref(sc->sc_chan)) != 0)
2125 		return (error);
2126 
2127 	sc->sc_flags |= ATABUSCF_OPEN;
2128 
2129 	return (0);
2130 }
2131 
2132 
2133 int
2134 atabusclose(dev_t dev, int flag, int fmt, struct lwp *l)
2135 {
2136 	struct atabus_softc *sc =
2137 	    device_lookup_private(&atabus_cd, minor(dev));
2138 
2139 	ata_delref(sc->sc_chan);
2140 
2141 	sc->sc_flags &= ~ATABUSCF_OPEN;
2142 
2143 	return (0);
2144 }
2145 
2146 int
2147 atabusioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l)
2148 {
2149 	struct atabus_softc *sc =
2150 	    device_lookup_private(&atabus_cd, minor(dev));
2151 	struct ata_channel *chp = sc->sc_chan;
2152 	int min_drive, max_drive, drive;
2153 	int error;
2154 
2155 	/*
2156 	 * Enforce write permission for ioctls that change the
2157 	 * state of the bus.  Host adapter specific ioctls must
2158 	 * be checked by the adapter driver.
2159 	 */
2160 	switch (cmd) {
2161 	case ATABUSIOSCAN:
2162 	case ATABUSIODETACH:
2163 	case ATABUSIORESET:
2164 		if ((flag & FWRITE) == 0)
2165 			return (EBADF);
2166 	}
2167 
2168 	switch (cmd) {
2169 	case ATABUSIORESET:
2170 		ata_channel_lock(chp);
2171 		ata_thread_run(sc->sc_chan, AT_WAIT | AT_POLL,
2172 		    ATACH_TH_RESET, ATACH_NODRIVE);
2173 		ata_channel_unlock(chp);
2174 		return 0;
2175 	case ATABUSIOSCAN:
2176 	{
2177 #if 0
2178 		struct atabusioscan_args *a=
2179 		    (struct atabusioscan_args *)addr;
2180 #endif
2181 		if ((chp->ch_drive[0].drive_type == ATA_DRIVET_OLD) ||
2182 		    (chp->ch_drive[1].drive_type == ATA_DRIVET_OLD))
2183 			return (EOPNOTSUPP);
2184 		return (EOPNOTSUPP);
2185 	}
2186 	case ATABUSIODETACH:
2187 	{
2188 		struct atabusiodetach_args *a=
2189 		    (struct atabusiodetach_args *)addr;
2190 		if ((chp->ch_drive[0].drive_type == ATA_DRIVET_OLD) ||
2191 		    (chp->ch_drive[1].drive_type == ATA_DRIVET_OLD))
2192 			return (EOPNOTSUPP);
2193 		switch (a->at_dev) {
2194 		case -1:
2195 			min_drive = 0;
2196 			max_drive = 1;
2197 			break;
2198 		case 0:
2199 		case 1:
2200 			min_drive = max_drive = a->at_dev;
2201 			break;
2202 		default:
2203 			return (EINVAL);
2204 		}
2205 		for (drive = min_drive; drive <= max_drive; drive++) {
2206 			if (chp->ch_drive[drive].drv_softc != NULL) {
2207 				error = config_detach(
2208 				    chp->ch_drive[drive].drv_softc, 0);
2209 				if (error)
2210 					return (error);
2211 				KASSERT(chp->ch_drive[drive].drv_softc == NULL);
2212 			}
2213 		}
2214 		return 0;
2215 	}
2216 	default:
2217 		return ENOTTY;
2218 	}
2219 }
2220 
2221 static bool
2222 atabus_suspend(device_t dv, const pmf_qual_t *qual)
2223 {
2224 	struct atabus_softc *sc = device_private(dv);
2225 	struct ata_channel *chp = sc->sc_chan;
2226 
2227 	ata_channel_idle(chp);
2228 
2229 	return true;
2230 }
2231 
2232 static bool
2233 atabus_resume(device_t dv, const pmf_qual_t *qual)
2234 {
2235 	struct atabus_softc *sc = device_private(dv);
2236 	struct ata_channel *chp = sc->sc_chan;
2237 
2238 	/*
2239 	 * XXX joerg: with wdc, the first channel unfreezes the controller.
2240 	 * Move this the reset and queue idling into wdc.
2241 	 */
2242 	ata_channel_lock(chp);
2243 	if (chp->ch_queue->queue_freeze == 0) {
2244 		ata_channel_unlock(chp);
2245 		goto out;
2246 	}
2247 
2248 	/* unfreeze the queue and reset drives */
2249 	ata_channel_thaw_locked(chp);
2250 
2251 	/* reset channel only if there are drives attached */
2252 	if (chp->ch_ndrives > 0)
2253 		ata_thread_run(chp, AT_WAIT, ATACH_TH_RESET, ATACH_NODRIVE);
2254 
2255 	ata_channel_unlock(chp);
2256 
2257 out:
2258 	return true;
2259 }
2260 
2261 static int
2262 atabus_rescan(device_t self, const char *ifattr, const int *locators)
2263 {
2264 	struct atabus_softc *sc = device_private(self);
2265 	struct ata_channel *chp = sc->sc_chan;
2266 	struct atabus_initq *initq;
2267 	int i;
2268 
2269 	/*
2270 	 * we can rescan a port multiplier atabus, even if some devices are
2271 	 * still attached
2272 	 */
2273 	if (chp->ch_satapmp_nports == 0) {
2274 		if (chp->atapibus != NULL) {
2275 			return EBUSY;
2276 		}
2277 
2278 		KASSERT(chp->ch_ndrives == 0 || chp->ch_drive != NULL);
2279 		for (i = 0; i < chp->ch_ndrives; i++) {
2280 			if (chp->ch_drive[i].drv_softc != NULL) {
2281 				return EBUSY;
2282 			}
2283 		}
2284 	}
2285 
2286 	initq = kmem_zalloc(sizeof(*initq), KM_SLEEP);
2287 	initq->atabus_sc = sc;
2288 	mutex_enter(&atabus_qlock);
2289 	TAILQ_INSERT_TAIL(&atabus_initq_head, initq, atabus_initq);
2290 	mutex_exit(&atabus_qlock);
2291 	config_pending_incr(sc->sc_dev);
2292 
2293 	ata_channel_lock(chp);
2294 	chp->ch_flags |= ATACH_TH_RESCAN;
2295 	cv_signal(&chp->ch_thr_idle);
2296 	ata_channel_unlock(chp);
2297 
2298 	return 0;
2299 }
2300 
2301 void
2302 ata_delay(struct ata_channel *chp, int ms, const char *msg, int flags)
2303 {
2304 	KASSERT(mutex_owned(&chp->ch_lock));
2305 
2306 	if ((flags & (AT_WAIT | AT_POLL)) == AT_POLL) {
2307 		/*
2308 		 * can't use kpause(), we may be in interrupt context
2309 		 * or taking a crash dump
2310 		 */
2311 		delay(ms * 1000);
2312 	} else {
2313 		int pause = mstohz(ms);
2314 
2315 		kpause(msg, false, pause > 0 ? pause : 1, &chp->ch_lock);
2316 	}
2317 }
2318 
2319 void
2320 atacmd_toncq(struct ata_xfer *xfer, uint8_t *cmd, uint16_t *count,
2321     uint16_t *features, uint8_t *device)
2322 {
2323 	if ((xfer->c_flags & C_NCQ) == 0) {
2324 		/* FUA handling for non-NCQ drives */
2325 		if (xfer->c_bio.flags & ATA_FUA
2326 		    && *cmd == WDCC_WRITEDMA_EXT)
2327 			*cmd = WDCC_WRITEDMA_FUA_EXT;
2328 
2329 		return;
2330 	}
2331 
2332 	*cmd = (xfer->c_bio.flags & ATA_READ) ?
2333 	    WDCC_READ_FPDMA_QUEUED : WDCC_WRITE_FPDMA_QUEUED;
2334 
2335 	/* for FPDMA the block count is in features */
2336 	*features = *count;
2337 
2338 	/* NCQ tag */
2339 	*count = (xfer->c_slot << 3);
2340 
2341 	if (xfer->c_bio.flags & ATA_PRIO_HIGH)
2342 		*count |= WDSC_PRIO_HIGH;
2343 
2344 	/* other device flags */
2345 	if (xfer->c_bio.flags & ATA_FUA)
2346 		*device |= WDSD_FUA;
2347 }
2348 
2349 void
2350 ata_wait_cmd(struct ata_channel *chp, struct ata_xfer *xfer)
2351 {
2352 	struct ata_queue *chq = chp->ch_queue;
2353 	struct ata_command *ata_c = &xfer->c_ata_c;
2354 
2355 	ata_channel_lock(chp);
2356 
2357 	while ((ata_c->flags & AT_DONE) == 0)
2358 		cv_wait(&chq->c_cmd_finish, &chp->ch_lock);
2359 
2360 	ata_channel_unlock(chp);
2361 
2362 	KASSERT((ata_c->flags & AT_DONE) != 0);
2363 }
2364