xref: /freebsd/sys/dev/nvme/nvme_ctrlr.c (revision 3984400149a53982f1254cfaf7b73fd2acda460a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (C) 2012-2016 Intel Corporation
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_cam.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/buf.h>
37 #include <sys/bus.h>
38 #include <sys/conf.h>
39 #include <sys/ioccom.h>
40 #include <sys/proc.h>
41 #include <sys/smp.h>
42 #include <sys/uio.h>
43 #include <sys/sbuf.h>
44 #include <sys/endian.h>
45 #include <machine/stdarg.h>
46 #include <vm/vm.h>
47 
48 #include "nvme_private.h"
49 
50 #define B4_CHK_RDY_DELAY_MS	2300		/* work around controller bug */
51 
52 static void nvme_ctrlr_construct_and_submit_aer(struct nvme_controller *ctrlr,
53 						struct nvme_async_event_request *aer);
54 
55 static void
56 nvme_ctrlr_devctl_log(struct nvme_controller *ctrlr, const char *type, const char *msg, ...)
57 {
58 	struct sbuf sb;
59 	va_list ap;
60 	int error;
61 
62 	if (sbuf_new(&sb, NULL, 0, SBUF_AUTOEXTEND | SBUF_NOWAIT) == NULL)
63 		return;
64 	sbuf_printf(&sb, "%s: ", device_get_nameunit(ctrlr->dev));
65 	va_start(ap, msg);
66 	sbuf_vprintf(&sb, msg, ap);
67 	va_end(ap);
68 	error = sbuf_finish(&sb);
69 	if (error == 0)
70 		printf("%s\n", sbuf_data(&sb));
71 
72 	sbuf_clear(&sb);
73 	sbuf_printf(&sb, "name=\"%s\" reason=\"", device_get_nameunit(ctrlr->dev));
74 	va_start(ap, msg);
75 	sbuf_vprintf(&sb, msg, ap);
76 	va_end(ap);
77 	sbuf_printf(&sb, "\"");
78 	error = sbuf_finish(&sb);
79 	if (error == 0)
80 		devctl_notify("nvme", "controller", type, sbuf_data(&sb));
81 	sbuf_delete(&sb);
82 }
83 
84 static int
85 nvme_ctrlr_construct_admin_qpair(struct nvme_controller *ctrlr)
86 {
87 	struct nvme_qpair	*qpair;
88 	uint32_t		num_entries;
89 	int			error;
90 
91 	qpair = &ctrlr->adminq;
92 	qpair->id = 0;
93 	qpair->cpu = CPU_FFS(&cpuset_domain[ctrlr->domain]) - 1;
94 	qpair->domain = ctrlr->domain;
95 
96 	num_entries = NVME_ADMIN_ENTRIES;
97 	TUNABLE_INT_FETCH("hw.nvme.admin_entries", &num_entries);
98 	/*
99 	 * If admin_entries was overridden to an invalid value, revert it
100 	 *  back to our default value.
101 	 */
102 	if (num_entries < NVME_MIN_ADMIN_ENTRIES ||
103 	    num_entries > NVME_MAX_ADMIN_ENTRIES) {
104 		nvme_printf(ctrlr, "invalid hw.nvme.admin_entries=%d "
105 		    "specified\n", num_entries);
106 		num_entries = NVME_ADMIN_ENTRIES;
107 	}
108 
109 	/*
110 	 * The admin queue's max xfer size is treated differently than the
111 	 *  max I/O xfer size.  16KB is sufficient here - maybe even less?
112 	 */
113 	error = nvme_qpair_construct(qpair, num_entries, NVME_ADMIN_TRACKERS,
114 	     ctrlr);
115 	return (error);
116 }
117 
118 #define QP(ctrlr, c)	((c) * (ctrlr)->num_io_queues / mp_ncpus)
119 
120 static int
121 nvme_ctrlr_construct_io_qpairs(struct nvme_controller *ctrlr)
122 {
123 	struct nvme_qpair	*qpair;
124 	uint32_t		cap_lo;
125 	uint16_t		mqes;
126 	int			c, error, i, n;
127 	int			num_entries, num_trackers, max_entries;
128 
129 	/*
130 	 * NVMe spec sets a hard limit of 64K max entries, but devices may
131 	 * specify a smaller limit, so we need to check the MQES field in the
132 	 * capabilities register. We have to cap the number of entries to the
133 	 * current stride allows for in BAR 0/1, otherwise the remainder entries
134 	 * are inaccessable. MQES should reflect this, and this is just a
135 	 * fail-safe.
136 	 */
137 	max_entries =
138 	    (rman_get_size(ctrlr->resource) - nvme_mmio_offsetof(doorbell[0])) /
139 	    (1 << (ctrlr->dstrd + 1));
140 	num_entries = NVME_IO_ENTRIES;
141 	TUNABLE_INT_FETCH("hw.nvme.io_entries", &num_entries);
142 	cap_lo = nvme_mmio_read_4(ctrlr, cap_lo);
143 	mqes = NVME_CAP_LO_MQES(cap_lo);
144 	num_entries = min(num_entries, mqes + 1);
145 	num_entries = min(num_entries, max_entries);
146 
147 	num_trackers = NVME_IO_TRACKERS;
148 	TUNABLE_INT_FETCH("hw.nvme.io_trackers", &num_trackers);
149 
150 	num_trackers = max(num_trackers, NVME_MIN_IO_TRACKERS);
151 	num_trackers = min(num_trackers, NVME_MAX_IO_TRACKERS);
152 	/*
153 	 * No need to have more trackers than entries in the submit queue.  Note
154 	 * also that for a queue size of N, we can only have (N-1) commands
155 	 * outstanding, hence the "-1" here.
156 	 */
157 	num_trackers = min(num_trackers, (num_entries-1));
158 
159 	/*
160 	 * Our best estimate for the maximum number of I/Os that we should
161 	 * normally have in flight at one time. This should be viewed as a hint,
162 	 * not a hard limit and will need to be revisited when the upper layers
163 	 * of the storage system grows multi-queue support.
164 	 */
165 	ctrlr->max_hw_pend_io = num_trackers * ctrlr->num_io_queues * 3 / 4;
166 
167 	ctrlr->ioq = malloc(ctrlr->num_io_queues * sizeof(struct nvme_qpair),
168 	    M_NVME, M_ZERO | M_WAITOK);
169 
170 	for (i = c = n = 0; i < ctrlr->num_io_queues; i++, c += n) {
171 		qpair = &ctrlr->ioq[i];
172 
173 		/*
174 		 * Admin queue has ID=0. IO queues start at ID=1 -
175 		 *  hence the 'i+1' here.
176 		 */
177 		qpair->id = i + 1;
178 		if (ctrlr->num_io_queues > 1) {
179 			/* Find number of CPUs served by this queue. */
180 			for (n = 1; QP(ctrlr, c + n) == i; n++)
181 				;
182 			/* Shuffle multiple NVMe devices between CPUs. */
183 			qpair->cpu = c + (device_get_unit(ctrlr->dev)+n/2) % n;
184 			qpair->domain = pcpu_find(qpair->cpu)->pc_domain;
185 		} else {
186 			qpair->cpu = CPU_FFS(&cpuset_domain[ctrlr->domain]) - 1;
187 			qpair->domain = ctrlr->domain;
188 		}
189 
190 		/*
191 		 * For I/O queues, use the controller-wide max_xfer_size
192 		 *  calculated in nvme_attach().
193 		 */
194 		error = nvme_qpair_construct(qpair, num_entries, num_trackers,
195 		    ctrlr);
196 		if (error)
197 			return (error);
198 
199 		/*
200 		 * Do not bother binding interrupts if we only have one I/O
201 		 *  interrupt thread for this controller.
202 		 */
203 		if (ctrlr->num_io_queues > 1)
204 			bus_bind_intr(ctrlr->dev, qpair->res, qpair->cpu);
205 	}
206 
207 	return (0);
208 }
209 
210 static void
211 nvme_ctrlr_fail(struct nvme_controller *ctrlr)
212 {
213 	int i;
214 
215 	ctrlr->is_failed = true;
216 	nvme_admin_qpair_disable(&ctrlr->adminq);
217 	nvme_qpair_fail(&ctrlr->adminq);
218 	if (ctrlr->ioq != NULL) {
219 		for (i = 0; i < ctrlr->num_io_queues; i++) {
220 			nvme_io_qpair_disable(&ctrlr->ioq[i]);
221 			nvme_qpair_fail(&ctrlr->ioq[i]);
222 		}
223 	}
224 	nvme_notify_fail_consumers(ctrlr);
225 }
226 
227 void
228 nvme_ctrlr_post_failed_request(struct nvme_controller *ctrlr,
229     struct nvme_request *req)
230 {
231 
232 	mtx_lock(&ctrlr->lock);
233 	STAILQ_INSERT_TAIL(&ctrlr->fail_req, req, stailq);
234 	mtx_unlock(&ctrlr->lock);
235 	if (!ctrlr->is_dying)
236 		taskqueue_enqueue(ctrlr->taskqueue, &ctrlr->fail_req_task);
237 }
238 
239 static void
240 nvme_ctrlr_fail_req_task(void *arg, int pending)
241 {
242 	struct nvme_controller	*ctrlr = arg;
243 	struct nvme_request	*req;
244 
245 	mtx_lock(&ctrlr->lock);
246 	while ((req = STAILQ_FIRST(&ctrlr->fail_req)) != NULL) {
247 		STAILQ_REMOVE_HEAD(&ctrlr->fail_req, stailq);
248 		mtx_unlock(&ctrlr->lock);
249 		nvme_qpair_manual_complete_request(req->qpair, req,
250 		    NVME_SCT_GENERIC, NVME_SC_ABORTED_BY_REQUEST);
251 		mtx_lock(&ctrlr->lock);
252 	}
253 	mtx_unlock(&ctrlr->lock);
254 }
255 
256 static int
257 nvme_ctrlr_wait_for_ready(struct nvme_controller *ctrlr, int desired_val)
258 {
259 	int timeout = ticks + (uint64_t)ctrlr->ready_timeout_in_ms * hz / 1000;
260 	uint32_t csts;
261 
262 	while (1) {
263 		csts = nvme_mmio_read_4(ctrlr, csts);
264 		if (csts == NVME_GONE)		/* Hot unplug. */
265 			return (ENXIO);
266 		if (((csts >> NVME_CSTS_REG_RDY_SHIFT) & NVME_CSTS_REG_RDY_MASK)
267 		    == desired_val)
268 			break;
269 		if (timeout - ticks < 0) {
270 			nvme_printf(ctrlr, "controller ready did not become %d "
271 			    "within %d ms\n", desired_val, ctrlr->ready_timeout_in_ms);
272 			return (ENXIO);
273 		}
274 		pause("nvmerdy", 1);
275 	}
276 
277 	return (0);
278 }
279 
280 static int
281 nvme_ctrlr_disable(struct nvme_controller *ctrlr)
282 {
283 	uint32_t cc;
284 	uint32_t csts;
285 	uint8_t  en, rdy;
286 	int err;
287 
288 	cc = nvme_mmio_read_4(ctrlr, cc);
289 	csts = nvme_mmio_read_4(ctrlr, csts);
290 
291 	en = (cc >> NVME_CC_REG_EN_SHIFT) & NVME_CC_REG_EN_MASK;
292 	rdy = (csts >> NVME_CSTS_REG_RDY_SHIFT) & NVME_CSTS_REG_RDY_MASK;
293 
294 	/*
295 	 * Per 3.1.5 in NVME 1.3 spec, transitioning CC.EN from 0 to 1
296 	 * when CSTS.RDY is 1 or transitioning CC.EN from 1 to 0 when
297 	 * CSTS.RDY is 0 "has undefined results" So make sure that CSTS.RDY
298 	 * isn't the desired value. Short circuit if we're already disabled.
299 	 */
300 	if (en == 1) {
301 		if (rdy == 0) {
302 			/* EN == 1, wait for  RDY == 1 or fail */
303 			err = nvme_ctrlr_wait_for_ready(ctrlr, 1);
304 			if (err != 0)
305 				return (err);
306 		}
307 	} else {
308 		/* EN == 0 already wait for RDY == 0 */
309 		if (rdy == 0)
310 			return (0);
311 		else
312 			return (nvme_ctrlr_wait_for_ready(ctrlr, 0));
313 	}
314 
315 	cc &= ~NVME_CC_REG_EN_MASK;
316 	nvme_mmio_write_4(ctrlr, cc, cc);
317 	/*
318 	 * Some drives have issues with accessing the mmio after we
319 	 * disable, so delay for a bit after we write the bit to
320 	 * cope with these issues.
321 	 */
322 	if (ctrlr->quirks & QUIRK_DELAY_B4_CHK_RDY)
323 		pause("nvmeR", B4_CHK_RDY_DELAY_MS * hz / 1000);
324 	return (nvme_ctrlr_wait_for_ready(ctrlr, 0));
325 }
326 
327 static int
328 nvme_ctrlr_enable(struct nvme_controller *ctrlr)
329 {
330 	uint32_t	cc;
331 	uint32_t	csts;
332 	uint32_t	aqa;
333 	uint32_t	qsize;
334 	uint8_t		en, rdy;
335 	int		err;
336 
337 	cc = nvme_mmio_read_4(ctrlr, cc);
338 	csts = nvme_mmio_read_4(ctrlr, csts);
339 
340 	en = (cc >> NVME_CC_REG_EN_SHIFT) & NVME_CC_REG_EN_MASK;
341 	rdy = (csts >> NVME_CSTS_REG_RDY_SHIFT) & NVME_CSTS_REG_RDY_MASK;
342 
343 	/*
344 	 * See note in nvme_ctrlr_disable. Short circuit if we're already enabled.
345 	 */
346 	if (en == 1) {
347 		if (rdy == 1)
348 			return (0);
349 		else
350 			return (nvme_ctrlr_wait_for_ready(ctrlr, 1));
351 	} else {
352 		/* EN == 0 already wait for RDY == 0 or fail */
353 		err = nvme_ctrlr_wait_for_ready(ctrlr, 0);
354 		if (err != 0)
355 			return (err);
356 	}
357 
358 	nvme_mmio_write_8(ctrlr, asq, ctrlr->adminq.cmd_bus_addr);
359 	DELAY(5000);
360 	nvme_mmio_write_8(ctrlr, acq, ctrlr->adminq.cpl_bus_addr);
361 	DELAY(5000);
362 
363 	/* acqs and asqs are 0-based. */
364 	qsize = ctrlr->adminq.num_entries - 1;
365 
366 	aqa = 0;
367 	aqa = (qsize & NVME_AQA_REG_ACQS_MASK) << NVME_AQA_REG_ACQS_SHIFT;
368 	aqa |= (qsize & NVME_AQA_REG_ASQS_MASK) << NVME_AQA_REG_ASQS_SHIFT;
369 	nvme_mmio_write_4(ctrlr, aqa, aqa);
370 	DELAY(5000);
371 
372 	/* Initialization values for CC */
373 	cc = 0;
374 	cc |= 1 << NVME_CC_REG_EN_SHIFT;
375 	cc |= 0 << NVME_CC_REG_CSS_SHIFT;
376 	cc |= 0 << NVME_CC_REG_AMS_SHIFT;
377 	cc |= 0 << NVME_CC_REG_SHN_SHIFT;
378 	cc |= 6 << NVME_CC_REG_IOSQES_SHIFT; /* SQ entry size == 64 == 2^6 */
379 	cc |= 4 << NVME_CC_REG_IOCQES_SHIFT; /* CQ entry size == 16 == 2^4 */
380 
381 	/* This evaluates to 0, which is according to spec. */
382 	cc |= (PAGE_SIZE >> 13) << NVME_CC_REG_MPS_SHIFT;
383 
384 	nvme_mmio_write_4(ctrlr, cc, cc);
385 
386 	return (nvme_ctrlr_wait_for_ready(ctrlr, 1));
387 }
388 
389 static void
390 nvme_ctrlr_disable_qpairs(struct nvme_controller *ctrlr)
391 {
392 	int i;
393 
394 	nvme_admin_qpair_disable(&ctrlr->adminq);
395 	/*
396 	 * I/O queues are not allocated before the initial HW
397 	 *  reset, so do not try to disable them.  Use is_initialized
398 	 *  to determine if this is the initial HW reset.
399 	 */
400 	if (ctrlr->is_initialized) {
401 		for (i = 0; i < ctrlr->num_io_queues; i++)
402 			nvme_io_qpair_disable(&ctrlr->ioq[i]);
403 	}
404 }
405 
406 static int
407 nvme_ctrlr_hw_reset(struct nvme_controller *ctrlr)
408 {
409 	int err;
410 
411 	TSENTER();
412 	nvme_ctrlr_disable_qpairs(ctrlr);
413 
414 	pause("nvmehwreset", hz / 10);
415 
416 	err = nvme_ctrlr_disable(ctrlr);
417 	if (err != 0)
418 		return err;
419 	err = nvme_ctrlr_enable(ctrlr);
420 	TSEXIT();
421 	return (err);
422 }
423 
424 void
425 nvme_ctrlr_reset(struct nvme_controller *ctrlr)
426 {
427 	int cmpset;
428 
429 	cmpset = atomic_cmpset_32(&ctrlr->is_resetting, 0, 1);
430 
431 	if (cmpset == 0 || ctrlr->is_failed)
432 		/*
433 		 * Controller is already resetting or has failed.  Return
434 		 *  immediately since there is no need to kick off another
435 		 *  reset in these cases.
436 		 */
437 		return;
438 
439 	if (!ctrlr->is_dying)
440 		taskqueue_enqueue(ctrlr->taskqueue, &ctrlr->reset_task);
441 }
442 
443 static int
444 nvme_ctrlr_identify(struct nvme_controller *ctrlr)
445 {
446 	struct nvme_completion_poll_status	status;
447 
448 	status.done = 0;
449 	nvme_ctrlr_cmd_identify_controller(ctrlr, &ctrlr->cdata,
450 	    nvme_completion_poll_cb, &status);
451 	nvme_completion_poll(&status);
452 	if (nvme_completion_is_error(&status.cpl)) {
453 		nvme_printf(ctrlr, "nvme_identify_controller failed!\n");
454 		return (ENXIO);
455 	}
456 
457 	/* Convert data to host endian */
458 	nvme_controller_data_swapbytes(&ctrlr->cdata);
459 
460 	/*
461 	 * Use MDTS to ensure our default max_xfer_size doesn't exceed what the
462 	 *  controller supports.
463 	 */
464 	if (ctrlr->cdata.mdts > 0)
465 		ctrlr->max_xfer_size = min(ctrlr->max_xfer_size,
466 		    ctrlr->min_page_size * (1 << (ctrlr->cdata.mdts)));
467 
468 	return (0);
469 }
470 
471 static int
472 nvme_ctrlr_set_num_qpairs(struct nvme_controller *ctrlr)
473 {
474 	struct nvme_completion_poll_status	status;
475 	int					cq_allocated, sq_allocated;
476 
477 	status.done = 0;
478 	nvme_ctrlr_cmd_set_num_queues(ctrlr, ctrlr->num_io_queues,
479 	    nvme_completion_poll_cb, &status);
480 	nvme_completion_poll(&status);
481 	if (nvme_completion_is_error(&status.cpl)) {
482 		nvme_printf(ctrlr, "nvme_ctrlr_set_num_qpairs failed!\n");
483 		return (ENXIO);
484 	}
485 
486 	/*
487 	 * Data in cdw0 is 0-based.
488 	 * Lower 16-bits indicate number of submission queues allocated.
489 	 * Upper 16-bits indicate number of completion queues allocated.
490 	 */
491 	sq_allocated = (status.cpl.cdw0 & 0xFFFF) + 1;
492 	cq_allocated = (status.cpl.cdw0 >> 16) + 1;
493 
494 	/*
495 	 * Controller may allocate more queues than we requested,
496 	 *  so use the minimum of the number requested and what was
497 	 *  actually allocated.
498 	 */
499 	ctrlr->num_io_queues = min(ctrlr->num_io_queues, sq_allocated);
500 	ctrlr->num_io_queues = min(ctrlr->num_io_queues, cq_allocated);
501 	if (ctrlr->num_io_queues > vm_ndomains)
502 		ctrlr->num_io_queues -= ctrlr->num_io_queues % vm_ndomains;
503 
504 	return (0);
505 }
506 
507 static int
508 nvme_ctrlr_create_qpairs(struct nvme_controller *ctrlr)
509 {
510 	struct nvme_completion_poll_status	status;
511 	struct nvme_qpair			*qpair;
512 	int					i;
513 
514 	for (i = 0; i < ctrlr->num_io_queues; i++) {
515 		qpair = &ctrlr->ioq[i];
516 
517 		status.done = 0;
518 		nvme_ctrlr_cmd_create_io_cq(ctrlr, qpair,
519 		    nvme_completion_poll_cb, &status);
520 		nvme_completion_poll(&status);
521 		if (nvme_completion_is_error(&status.cpl)) {
522 			nvme_printf(ctrlr, "nvme_create_io_cq failed!\n");
523 			return (ENXIO);
524 		}
525 
526 		status.done = 0;
527 		nvme_ctrlr_cmd_create_io_sq(ctrlr, qpair,
528 		    nvme_completion_poll_cb, &status);
529 		nvme_completion_poll(&status);
530 		if (nvme_completion_is_error(&status.cpl)) {
531 			nvme_printf(ctrlr, "nvme_create_io_sq failed!\n");
532 			return (ENXIO);
533 		}
534 	}
535 
536 	return (0);
537 }
538 
539 static int
540 nvme_ctrlr_delete_qpairs(struct nvme_controller *ctrlr)
541 {
542 	struct nvme_completion_poll_status	status;
543 	struct nvme_qpair			*qpair;
544 
545 	for (int i = 0; i < ctrlr->num_io_queues; i++) {
546 		qpair = &ctrlr->ioq[i];
547 
548 		status.done = 0;
549 		nvme_ctrlr_cmd_delete_io_sq(ctrlr, qpair,
550 		    nvme_completion_poll_cb, &status);
551 		nvme_completion_poll(&status);
552 		if (nvme_completion_is_error(&status.cpl)) {
553 			nvme_printf(ctrlr, "nvme_destroy_io_sq failed!\n");
554 			return (ENXIO);
555 		}
556 
557 		status.done = 0;
558 		nvme_ctrlr_cmd_delete_io_cq(ctrlr, qpair,
559 		    nvme_completion_poll_cb, &status);
560 		nvme_completion_poll(&status);
561 		if (nvme_completion_is_error(&status.cpl)) {
562 			nvme_printf(ctrlr, "nvme_destroy_io_cq failed!\n");
563 			return (ENXIO);
564 		}
565 	}
566 
567 	return (0);
568 }
569 
570 static int
571 nvme_ctrlr_construct_namespaces(struct nvme_controller *ctrlr)
572 {
573 	struct nvme_namespace	*ns;
574 	uint32_t 		i;
575 
576 	for (i = 0; i < min(ctrlr->cdata.nn, NVME_MAX_NAMESPACES); i++) {
577 		ns = &ctrlr->ns[i];
578 		nvme_ns_construct(ns, i+1, ctrlr);
579 	}
580 
581 	return (0);
582 }
583 
584 static bool
585 is_log_page_id_valid(uint8_t page_id)
586 {
587 
588 	switch (page_id) {
589 	case NVME_LOG_ERROR:
590 	case NVME_LOG_HEALTH_INFORMATION:
591 	case NVME_LOG_FIRMWARE_SLOT:
592 	case NVME_LOG_CHANGED_NAMESPACE:
593 	case NVME_LOG_COMMAND_EFFECT:
594 	case NVME_LOG_RES_NOTIFICATION:
595 	case NVME_LOG_SANITIZE_STATUS:
596 		return (true);
597 	}
598 
599 	return (false);
600 }
601 
602 static uint32_t
603 nvme_ctrlr_get_log_page_size(struct nvme_controller *ctrlr, uint8_t page_id)
604 {
605 	uint32_t	log_page_size;
606 
607 	switch (page_id) {
608 	case NVME_LOG_ERROR:
609 		log_page_size = min(
610 		    sizeof(struct nvme_error_information_entry) *
611 		    (ctrlr->cdata.elpe + 1), NVME_MAX_AER_LOG_SIZE);
612 		break;
613 	case NVME_LOG_HEALTH_INFORMATION:
614 		log_page_size = sizeof(struct nvme_health_information_page);
615 		break;
616 	case NVME_LOG_FIRMWARE_SLOT:
617 		log_page_size = sizeof(struct nvme_firmware_page);
618 		break;
619 	case NVME_LOG_CHANGED_NAMESPACE:
620 		log_page_size = sizeof(struct nvme_ns_list);
621 		break;
622 	case NVME_LOG_COMMAND_EFFECT:
623 		log_page_size = sizeof(struct nvme_command_effects_page);
624 		break;
625 	case NVME_LOG_RES_NOTIFICATION:
626 		log_page_size = sizeof(struct nvme_res_notification_page);
627 		break;
628 	case NVME_LOG_SANITIZE_STATUS:
629 		log_page_size = sizeof(struct nvme_sanitize_status_page);
630 		break;
631 	default:
632 		log_page_size = 0;
633 		break;
634 	}
635 
636 	return (log_page_size);
637 }
638 
639 static void
640 nvme_ctrlr_log_critical_warnings(struct nvme_controller *ctrlr,
641     uint8_t state)
642 {
643 
644 	if (state & NVME_CRIT_WARN_ST_AVAILABLE_SPARE)
645 		nvme_ctrlr_devctl_log(ctrlr, "critical",
646 		    "available spare space below threshold");
647 
648 	if (state & NVME_CRIT_WARN_ST_TEMPERATURE)
649 		nvme_ctrlr_devctl_log(ctrlr, "critical",
650 		    "temperature above threshold");
651 
652 	if (state & NVME_CRIT_WARN_ST_DEVICE_RELIABILITY)
653 		nvme_ctrlr_devctl_log(ctrlr, "critical",
654 		    "device reliability degraded");
655 
656 	if (state & NVME_CRIT_WARN_ST_READ_ONLY)
657 		nvme_ctrlr_devctl_log(ctrlr, "critical",
658 		    "media placed in read only mode");
659 
660 	if (state & NVME_CRIT_WARN_ST_VOLATILE_MEMORY_BACKUP)
661 		nvme_ctrlr_devctl_log(ctrlr, "critical",
662 		    "volatile memory backup device failed");
663 
664 	if (state & NVME_CRIT_WARN_ST_RESERVED_MASK)
665 		nvme_ctrlr_devctl_log(ctrlr, "critical",
666 		    "unknown critical warning(s): state = 0x%02x", state);
667 }
668 
669 static void
670 nvme_ctrlr_async_event_log_page_cb(void *arg, const struct nvme_completion *cpl)
671 {
672 	struct nvme_async_event_request		*aer = arg;
673 	struct nvme_health_information_page	*health_info;
674 	struct nvme_ns_list			*nsl;
675 	struct nvme_error_information_entry	*err;
676 	int i;
677 
678 	/*
679 	 * If the log page fetch for some reason completed with an error,
680 	 *  don't pass log page data to the consumers.  In practice, this case
681 	 *  should never happen.
682 	 */
683 	if (nvme_completion_is_error(cpl))
684 		nvme_notify_async_consumers(aer->ctrlr, &aer->cpl,
685 		    aer->log_page_id, NULL, 0);
686 	else {
687 		/* Convert data to host endian */
688 		switch (aer->log_page_id) {
689 		case NVME_LOG_ERROR:
690 			err = (struct nvme_error_information_entry *)aer->log_page_buffer;
691 			for (i = 0; i < (aer->ctrlr->cdata.elpe + 1); i++)
692 				nvme_error_information_entry_swapbytes(err++);
693 			break;
694 		case NVME_LOG_HEALTH_INFORMATION:
695 			nvme_health_information_page_swapbytes(
696 			    (struct nvme_health_information_page *)aer->log_page_buffer);
697 			break;
698 		case NVME_LOG_FIRMWARE_SLOT:
699 			nvme_firmware_page_swapbytes(
700 			    (struct nvme_firmware_page *)aer->log_page_buffer);
701 			break;
702 		case NVME_LOG_CHANGED_NAMESPACE:
703 			nvme_ns_list_swapbytes(
704 			    (struct nvme_ns_list *)aer->log_page_buffer);
705 			break;
706 		case NVME_LOG_COMMAND_EFFECT:
707 			nvme_command_effects_page_swapbytes(
708 			    (struct nvme_command_effects_page *)aer->log_page_buffer);
709 			break;
710 		case NVME_LOG_RES_NOTIFICATION:
711 			nvme_res_notification_page_swapbytes(
712 			    (struct nvme_res_notification_page *)aer->log_page_buffer);
713 			break;
714 		case NVME_LOG_SANITIZE_STATUS:
715 			nvme_sanitize_status_page_swapbytes(
716 			    (struct nvme_sanitize_status_page *)aer->log_page_buffer);
717 			break;
718 		case INTEL_LOG_TEMP_STATS:
719 			intel_log_temp_stats_swapbytes(
720 			    (struct intel_log_temp_stats *)aer->log_page_buffer);
721 			break;
722 		default:
723 			break;
724 		}
725 
726 		if (aer->log_page_id == NVME_LOG_HEALTH_INFORMATION) {
727 			health_info = (struct nvme_health_information_page *)
728 			    aer->log_page_buffer;
729 			nvme_ctrlr_log_critical_warnings(aer->ctrlr,
730 			    health_info->critical_warning);
731 			/*
732 			 * Critical warnings reported through the
733 			 *  SMART/health log page are persistent, so
734 			 *  clear the associated bits in the async event
735 			 *  config so that we do not receive repeated
736 			 *  notifications for the same event.
737 			 */
738 			aer->ctrlr->async_event_config &=
739 			    ~health_info->critical_warning;
740 			nvme_ctrlr_cmd_set_async_event_config(aer->ctrlr,
741 			    aer->ctrlr->async_event_config, NULL, NULL);
742 		} else if (aer->log_page_id == NVME_LOG_CHANGED_NAMESPACE &&
743 		    !nvme_use_nvd) {
744 			nsl = (struct nvme_ns_list *)aer->log_page_buffer;
745 			for (i = 0; i < nitems(nsl->ns) && nsl->ns[i] != 0; i++) {
746 				if (nsl->ns[i] > NVME_MAX_NAMESPACES)
747 					break;
748 				nvme_notify_ns(aer->ctrlr, nsl->ns[i]);
749 			}
750 		}
751 
752 		/*
753 		 * Pass the cpl data from the original async event completion,
754 		 *  not the log page fetch.
755 		 */
756 		nvme_notify_async_consumers(aer->ctrlr, &aer->cpl,
757 		    aer->log_page_id, aer->log_page_buffer, aer->log_page_size);
758 	}
759 
760 	/*
761 	 * Repost another asynchronous event request to replace the one
762 	 *  that just completed.
763 	 */
764 	nvme_ctrlr_construct_and_submit_aer(aer->ctrlr, aer);
765 }
766 
767 static void
768 nvme_ctrlr_async_event_cb(void *arg, const struct nvme_completion *cpl)
769 {
770 	struct nvme_async_event_request	*aer = arg;
771 
772 	if (nvme_completion_is_error(cpl)) {
773 		/*
774 		 *  Do not retry failed async event requests.  This avoids
775 		 *  infinite loops where a new async event request is submitted
776 		 *  to replace the one just failed, only to fail again and
777 		 *  perpetuate the loop.
778 		 */
779 		return;
780 	}
781 
782 	/* Associated log page is in bits 23:16 of completion entry dw0. */
783 	aer->log_page_id = (cpl->cdw0 & 0xFF0000) >> 16;
784 
785 	nvme_printf(aer->ctrlr, "async event occurred (type 0x%x, info 0x%02x,"
786 	    " page 0x%02x)\n", (cpl->cdw0 & 0x07), (cpl->cdw0 & 0xFF00) >> 8,
787 	    aer->log_page_id);
788 
789 	if (is_log_page_id_valid(aer->log_page_id)) {
790 		aer->log_page_size = nvme_ctrlr_get_log_page_size(aer->ctrlr,
791 		    aer->log_page_id);
792 		memcpy(&aer->cpl, cpl, sizeof(*cpl));
793 		nvme_ctrlr_cmd_get_log_page(aer->ctrlr, aer->log_page_id,
794 		    NVME_GLOBAL_NAMESPACE_TAG, aer->log_page_buffer,
795 		    aer->log_page_size, nvme_ctrlr_async_event_log_page_cb,
796 		    aer);
797 		/* Wait to notify consumers until after log page is fetched. */
798 	} else {
799 		nvme_notify_async_consumers(aer->ctrlr, cpl, aer->log_page_id,
800 		    NULL, 0);
801 
802 		/*
803 		 * Repost another asynchronous event request to replace the one
804 		 *  that just completed.
805 		 */
806 		nvme_ctrlr_construct_and_submit_aer(aer->ctrlr, aer);
807 	}
808 }
809 
810 static void
811 nvme_ctrlr_construct_and_submit_aer(struct nvme_controller *ctrlr,
812     struct nvme_async_event_request *aer)
813 {
814 	struct nvme_request *req;
815 
816 	aer->ctrlr = ctrlr;
817 	req = nvme_allocate_request_null(nvme_ctrlr_async_event_cb, aer);
818 	aer->req = req;
819 
820 	/*
821 	 * Disable timeout here, since asynchronous event requests should by
822 	 *  nature never be timed out.
823 	 */
824 	req->timeout = false;
825 	req->cmd.opc = NVME_OPC_ASYNC_EVENT_REQUEST;
826 	nvme_ctrlr_submit_admin_request(ctrlr, req);
827 }
828 
829 static void
830 nvme_ctrlr_configure_aer(struct nvme_controller *ctrlr)
831 {
832 	struct nvme_completion_poll_status	status;
833 	struct nvme_async_event_request		*aer;
834 	uint32_t				i;
835 
836 	ctrlr->async_event_config = NVME_CRIT_WARN_ST_AVAILABLE_SPARE |
837 	    NVME_CRIT_WARN_ST_DEVICE_RELIABILITY |
838 	    NVME_CRIT_WARN_ST_READ_ONLY |
839 	    NVME_CRIT_WARN_ST_VOLATILE_MEMORY_BACKUP;
840 	if (ctrlr->cdata.ver >= NVME_REV(1, 2))
841 		ctrlr->async_event_config |= NVME_ASYNC_EVENT_NS_ATTRIBUTE |
842 		    NVME_ASYNC_EVENT_FW_ACTIVATE;
843 
844 	status.done = 0;
845 	nvme_ctrlr_cmd_get_feature(ctrlr, NVME_FEAT_TEMPERATURE_THRESHOLD,
846 	    0, NULL, 0, nvme_completion_poll_cb, &status);
847 	nvme_completion_poll(&status);
848 	if (nvme_completion_is_error(&status.cpl) ||
849 	    (status.cpl.cdw0 & 0xFFFF) == 0xFFFF ||
850 	    (status.cpl.cdw0 & 0xFFFF) == 0x0000) {
851 		nvme_printf(ctrlr, "temperature threshold not supported\n");
852 	} else
853 		ctrlr->async_event_config |= NVME_CRIT_WARN_ST_TEMPERATURE;
854 
855 	nvme_ctrlr_cmd_set_async_event_config(ctrlr,
856 	    ctrlr->async_event_config, NULL, NULL);
857 
858 	/* aerl is a zero-based value, so we need to add 1 here. */
859 	ctrlr->num_aers = min(NVME_MAX_ASYNC_EVENTS, (ctrlr->cdata.aerl+1));
860 
861 	for (i = 0; i < ctrlr->num_aers; i++) {
862 		aer = &ctrlr->aer[i];
863 		nvme_ctrlr_construct_and_submit_aer(ctrlr, aer);
864 	}
865 }
866 
867 static void
868 nvme_ctrlr_configure_int_coalescing(struct nvme_controller *ctrlr)
869 {
870 
871 	ctrlr->int_coal_time = 0;
872 	TUNABLE_INT_FETCH("hw.nvme.int_coal_time",
873 	    &ctrlr->int_coal_time);
874 
875 	ctrlr->int_coal_threshold = 0;
876 	TUNABLE_INT_FETCH("hw.nvme.int_coal_threshold",
877 	    &ctrlr->int_coal_threshold);
878 
879 	nvme_ctrlr_cmd_set_interrupt_coalescing(ctrlr, ctrlr->int_coal_time,
880 	    ctrlr->int_coal_threshold, NULL, NULL);
881 }
882 
883 static void
884 nvme_ctrlr_hmb_free(struct nvme_controller *ctrlr)
885 {
886 	struct nvme_hmb_chunk *hmbc;
887 	int i;
888 
889 	if (ctrlr->hmb_desc_paddr) {
890 		bus_dmamap_unload(ctrlr->hmb_desc_tag, ctrlr->hmb_desc_map);
891 		bus_dmamem_free(ctrlr->hmb_desc_tag, ctrlr->hmb_desc_vaddr,
892 		    ctrlr->hmb_desc_map);
893 		ctrlr->hmb_desc_paddr = 0;
894 	}
895 	if (ctrlr->hmb_desc_tag) {
896 		bus_dma_tag_destroy(ctrlr->hmb_desc_tag);
897 		ctrlr->hmb_desc_tag = NULL;
898 	}
899 	for (i = 0; i < ctrlr->hmb_nchunks; i++) {
900 		hmbc = &ctrlr->hmb_chunks[i];
901 		bus_dmamap_unload(ctrlr->hmb_tag, hmbc->hmbc_map);
902 		bus_dmamem_free(ctrlr->hmb_tag, hmbc->hmbc_vaddr,
903 		    hmbc->hmbc_map);
904 	}
905 	ctrlr->hmb_nchunks = 0;
906 	if (ctrlr->hmb_tag) {
907 		bus_dma_tag_destroy(ctrlr->hmb_tag);
908 		ctrlr->hmb_tag = NULL;
909 	}
910 	if (ctrlr->hmb_chunks) {
911 		free(ctrlr->hmb_chunks, M_NVME);
912 		ctrlr->hmb_chunks = NULL;
913 	}
914 }
915 
916 static void
917 nvme_ctrlr_hmb_alloc(struct nvme_controller *ctrlr)
918 {
919 	struct nvme_hmb_chunk *hmbc;
920 	size_t pref, min, minc, size;
921 	int err, i;
922 	uint64_t max;
923 
924 	/* Limit HMB to 5% of RAM size per device by default. */
925 	max = (uint64_t)physmem * PAGE_SIZE / 20;
926 	TUNABLE_UINT64_FETCH("hw.nvme.hmb_max", &max);
927 
928 	min = (long long unsigned)ctrlr->cdata.hmmin * 4096;
929 	if (max == 0 || max < min)
930 		return;
931 	pref = MIN((long long unsigned)ctrlr->cdata.hmpre * 4096, max);
932 	minc = MAX(ctrlr->cdata.hmminds * 4096, PAGE_SIZE);
933 	if (min > 0 && ctrlr->cdata.hmmaxd > 0)
934 		minc = MAX(minc, min / ctrlr->cdata.hmmaxd);
935 	ctrlr->hmb_chunk = pref;
936 
937 again:
938 	ctrlr->hmb_chunk = roundup2(ctrlr->hmb_chunk, PAGE_SIZE);
939 	ctrlr->hmb_nchunks = howmany(pref, ctrlr->hmb_chunk);
940 	if (ctrlr->cdata.hmmaxd > 0 && ctrlr->hmb_nchunks > ctrlr->cdata.hmmaxd)
941 		ctrlr->hmb_nchunks = ctrlr->cdata.hmmaxd;
942 	ctrlr->hmb_chunks = malloc(sizeof(struct nvme_hmb_chunk) *
943 	    ctrlr->hmb_nchunks, M_NVME, M_WAITOK);
944 	err = bus_dma_tag_create(bus_get_dma_tag(ctrlr->dev),
945 	    PAGE_SIZE, 0, BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
946 	    ctrlr->hmb_chunk, 1, ctrlr->hmb_chunk, 0, NULL, NULL, &ctrlr->hmb_tag);
947 	if (err != 0) {
948 		nvme_printf(ctrlr, "HMB tag create failed %d\n", err);
949 		nvme_ctrlr_hmb_free(ctrlr);
950 		return;
951 	}
952 
953 	for (i = 0; i < ctrlr->hmb_nchunks; i++) {
954 		hmbc = &ctrlr->hmb_chunks[i];
955 		if (bus_dmamem_alloc(ctrlr->hmb_tag,
956 		    (void **)&hmbc->hmbc_vaddr, BUS_DMA_NOWAIT,
957 		    &hmbc->hmbc_map)) {
958 			nvme_printf(ctrlr, "failed to alloc HMB\n");
959 			break;
960 		}
961 		if (bus_dmamap_load(ctrlr->hmb_tag, hmbc->hmbc_map,
962 		    hmbc->hmbc_vaddr, ctrlr->hmb_chunk, nvme_single_map,
963 		    &hmbc->hmbc_paddr, BUS_DMA_NOWAIT) != 0) {
964 			bus_dmamem_free(ctrlr->hmb_tag, hmbc->hmbc_vaddr,
965 			    hmbc->hmbc_map);
966 			nvme_printf(ctrlr, "failed to load HMB\n");
967 			break;
968 		}
969 		bus_dmamap_sync(ctrlr->hmb_tag, hmbc->hmbc_map,
970 		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
971 	}
972 
973 	if (i < ctrlr->hmb_nchunks && i * ctrlr->hmb_chunk < min &&
974 	    ctrlr->hmb_chunk / 2 >= minc) {
975 		ctrlr->hmb_nchunks = i;
976 		nvme_ctrlr_hmb_free(ctrlr);
977 		ctrlr->hmb_chunk /= 2;
978 		goto again;
979 	}
980 	ctrlr->hmb_nchunks = i;
981 	if (ctrlr->hmb_nchunks * ctrlr->hmb_chunk < min) {
982 		nvme_ctrlr_hmb_free(ctrlr);
983 		return;
984 	}
985 
986 	size = sizeof(struct nvme_hmb_desc) * ctrlr->hmb_nchunks;
987 	err = bus_dma_tag_create(bus_get_dma_tag(ctrlr->dev),
988 	    16, 0, BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
989 	    size, 1, size, 0, NULL, NULL, &ctrlr->hmb_desc_tag);
990 	if (err != 0) {
991 		nvme_printf(ctrlr, "HMB desc tag create failed %d\n", err);
992 		nvme_ctrlr_hmb_free(ctrlr);
993 		return;
994 	}
995 	if (bus_dmamem_alloc(ctrlr->hmb_desc_tag,
996 	    (void **)&ctrlr->hmb_desc_vaddr, BUS_DMA_WAITOK,
997 	    &ctrlr->hmb_desc_map)) {
998 		nvme_printf(ctrlr, "failed to alloc HMB desc\n");
999 		nvme_ctrlr_hmb_free(ctrlr);
1000 		return;
1001 	}
1002 	if (bus_dmamap_load(ctrlr->hmb_desc_tag, ctrlr->hmb_desc_map,
1003 	    ctrlr->hmb_desc_vaddr, size, nvme_single_map,
1004 	    &ctrlr->hmb_desc_paddr, BUS_DMA_NOWAIT) != 0) {
1005 		bus_dmamem_free(ctrlr->hmb_desc_tag, ctrlr->hmb_desc_vaddr,
1006 		    ctrlr->hmb_desc_map);
1007 		nvme_printf(ctrlr, "failed to load HMB desc\n");
1008 		nvme_ctrlr_hmb_free(ctrlr);
1009 		return;
1010 	}
1011 
1012 	for (i = 0; i < ctrlr->hmb_nchunks; i++) {
1013 		ctrlr->hmb_desc_vaddr[i].addr =
1014 		    htole64(ctrlr->hmb_chunks[i].hmbc_paddr);
1015 		ctrlr->hmb_desc_vaddr[i].size = htole32(ctrlr->hmb_chunk / 4096);
1016 	}
1017 	bus_dmamap_sync(ctrlr->hmb_desc_tag, ctrlr->hmb_desc_map,
1018 	    BUS_DMASYNC_PREWRITE);
1019 
1020 	nvme_printf(ctrlr, "Allocated %lluMB host memory buffer\n",
1021 	    (long long unsigned)ctrlr->hmb_nchunks * ctrlr->hmb_chunk
1022 	    / 1024 / 1024);
1023 }
1024 
1025 static void
1026 nvme_ctrlr_hmb_enable(struct nvme_controller *ctrlr, bool enable, bool memret)
1027 {
1028 	struct nvme_completion_poll_status	status;
1029 	uint32_t cdw11;
1030 
1031 	cdw11 = 0;
1032 	if (enable)
1033 		cdw11 |= 1;
1034 	if (memret)
1035 		cdw11 |= 2;
1036 	status.done = 0;
1037 	nvme_ctrlr_cmd_set_feature(ctrlr, NVME_FEAT_HOST_MEMORY_BUFFER, cdw11,
1038 	    ctrlr->hmb_nchunks * ctrlr->hmb_chunk / 4096, ctrlr->hmb_desc_paddr,
1039 	    ctrlr->hmb_desc_paddr >> 32, ctrlr->hmb_nchunks, NULL, 0,
1040 	    nvme_completion_poll_cb, &status);
1041 	nvme_completion_poll(&status);
1042 	if (nvme_completion_is_error(&status.cpl))
1043 		nvme_printf(ctrlr, "nvme_ctrlr_hmb_enable failed!\n");
1044 }
1045 
1046 static void
1047 nvme_ctrlr_start(void *ctrlr_arg, bool resetting)
1048 {
1049 	struct nvme_controller *ctrlr = ctrlr_arg;
1050 	uint32_t old_num_io_queues;
1051 	int i;
1052 
1053 	TSENTER();
1054 
1055 	/*
1056 	 * Only reset adminq here when we are restarting the
1057 	 *  controller after a reset.  During initialization,
1058 	 *  we have already submitted admin commands to get
1059 	 *  the number of I/O queues supported, so cannot reset
1060 	 *  the adminq again here.
1061 	 */
1062 	if (resetting) {
1063 		nvme_qpair_reset(&ctrlr->adminq);
1064 		nvme_admin_qpair_enable(&ctrlr->adminq);
1065 	}
1066 
1067 	if (ctrlr->ioq != NULL) {
1068 		for (i = 0; i < ctrlr->num_io_queues; i++)
1069 			nvme_qpair_reset(&ctrlr->ioq[i]);
1070 	}
1071 
1072 	/*
1073 	 * If it was a reset on initialization command timeout, just
1074 	 * return here, letting initialization code fail gracefully.
1075 	 */
1076 	if (resetting && !ctrlr->is_initialized)
1077 		return;
1078 
1079 	if (resetting && nvme_ctrlr_identify(ctrlr) != 0) {
1080 		nvme_ctrlr_fail(ctrlr);
1081 		return;
1082 	}
1083 
1084 	/*
1085 	 * The number of qpairs are determined during controller initialization,
1086 	 *  including using NVMe SET_FEATURES/NUMBER_OF_QUEUES to determine the
1087 	 *  HW limit.  We call SET_FEATURES again here so that it gets called
1088 	 *  after any reset for controllers that depend on the driver to
1089 	 *  explicit specify how many queues it will use.  This value should
1090 	 *  never change between resets, so panic if somehow that does happen.
1091 	 */
1092 	if (resetting) {
1093 		old_num_io_queues = ctrlr->num_io_queues;
1094 		if (nvme_ctrlr_set_num_qpairs(ctrlr) != 0) {
1095 			nvme_ctrlr_fail(ctrlr);
1096 			return;
1097 		}
1098 
1099 		if (old_num_io_queues != ctrlr->num_io_queues) {
1100 			panic("num_io_queues changed from %u to %u",
1101 			      old_num_io_queues, ctrlr->num_io_queues);
1102 		}
1103 	}
1104 
1105 	if (ctrlr->cdata.hmpre > 0 && ctrlr->hmb_nchunks == 0) {
1106 		nvme_ctrlr_hmb_alloc(ctrlr);
1107 		if (ctrlr->hmb_nchunks > 0)
1108 			nvme_ctrlr_hmb_enable(ctrlr, true, false);
1109 	} else if (ctrlr->hmb_nchunks > 0)
1110 		nvme_ctrlr_hmb_enable(ctrlr, true, true);
1111 
1112 	if (nvme_ctrlr_create_qpairs(ctrlr) != 0) {
1113 		nvme_ctrlr_fail(ctrlr);
1114 		return;
1115 	}
1116 
1117 	if (nvme_ctrlr_construct_namespaces(ctrlr) != 0) {
1118 		nvme_ctrlr_fail(ctrlr);
1119 		return;
1120 	}
1121 
1122 	nvme_ctrlr_configure_aer(ctrlr);
1123 	nvme_ctrlr_configure_int_coalescing(ctrlr);
1124 
1125 	for (i = 0; i < ctrlr->num_io_queues; i++)
1126 		nvme_io_qpair_enable(&ctrlr->ioq[i]);
1127 	TSEXIT();
1128 }
1129 
1130 void
1131 nvme_ctrlr_start_config_hook(void *arg)
1132 {
1133 	struct nvme_controller *ctrlr = arg;
1134 
1135 	TSENTER();
1136 
1137 	/*
1138 	 * Reset controller twice to ensure we do a transition from cc.en==1 to
1139 	 * cc.en==0.  This is because we don't really know what status the
1140 	 * controller was left in when boot handed off to OS.  Linux doesn't do
1141 	 * this, however. If we adopt that policy, see also nvme_ctrlr_resume().
1142 	 */
1143 	if (nvme_ctrlr_hw_reset(ctrlr) != 0) {
1144 fail:
1145 		nvme_ctrlr_fail(ctrlr);
1146 		config_intrhook_disestablish(&ctrlr->config_hook);
1147 		return;
1148 	}
1149 
1150 	if (nvme_ctrlr_hw_reset(ctrlr) != 0)
1151 		goto fail;
1152 
1153 	nvme_qpair_reset(&ctrlr->adminq);
1154 	nvme_admin_qpair_enable(&ctrlr->adminq);
1155 
1156 	if (nvme_ctrlr_identify(ctrlr) == 0 &&
1157 	    nvme_ctrlr_set_num_qpairs(ctrlr) == 0 &&
1158 	    nvme_ctrlr_construct_io_qpairs(ctrlr) == 0)
1159 		nvme_ctrlr_start(ctrlr, false);
1160 	else
1161 		goto fail;
1162 
1163 	nvme_sysctl_initialize_ctrlr(ctrlr);
1164 	config_intrhook_disestablish(&ctrlr->config_hook);
1165 
1166 	ctrlr->is_initialized = 1;
1167 	nvme_notify_new_controller(ctrlr);
1168 	TSEXIT();
1169 }
1170 
1171 static void
1172 nvme_ctrlr_reset_task(void *arg, int pending)
1173 {
1174 	struct nvme_controller	*ctrlr = arg;
1175 	int			status;
1176 
1177 	nvme_ctrlr_devctl_log(ctrlr, "RESET", "resetting controller");
1178 	status = nvme_ctrlr_hw_reset(ctrlr);
1179 	/*
1180 	 * Use pause instead of DELAY, so that we yield to any nvme interrupt
1181 	 *  handlers on this CPU that were blocked on a qpair lock. We want
1182 	 *  all nvme interrupts completed before proceeding with restarting the
1183 	 *  controller.
1184 	 *
1185 	 * XXX - any way to guarantee the interrupt handlers have quiesced?
1186 	 */
1187 	pause("nvmereset", hz / 10);
1188 	if (status == 0)
1189 		nvme_ctrlr_start(ctrlr, true);
1190 	else
1191 		nvme_ctrlr_fail(ctrlr);
1192 
1193 	atomic_cmpset_32(&ctrlr->is_resetting, 1, 0);
1194 }
1195 
1196 /*
1197  * Poll all the queues enabled on the device for completion.
1198  */
1199 void
1200 nvme_ctrlr_poll(struct nvme_controller *ctrlr)
1201 {
1202 	int i;
1203 
1204 	nvme_qpair_process_completions(&ctrlr->adminq);
1205 
1206 	for (i = 0; i < ctrlr->num_io_queues; i++)
1207 		if (ctrlr->ioq && ctrlr->ioq[i].cpl)
1208 			nvme_qpair_process_completions(&ctrlr->ioq[i]);
1209 }
1210 
1211 /*
1212  * Poll the single-vector interrupt case: num_io_queues will be 1 and
1213  * there's only a single vector. While we're polling, we mask further
1214  * interrupts in the controller.
1215  */
1216 void
1217 nvme_ctrlr_shared_handler(void *arg)
1218 {
1219 	struct nvme_controller *ctrlr = arg;
1220 
1221 	nvme_mmio_write_4(ctrlr, intms, 1);
1222 	nvme_ctrlr_poll(ctrlr);
1223 	nvme_mmio_write_4(ctrlr, intmc, 1);
1224 }
1225 
1226 static void
1227 nvme_pt_done(void *arg, const struct nvme_completion *cpl)
1228 {
1229 	struct nvme_pt_command *pt = arg;
1230 	struct mtx *mtx = pt->driver_lock;
1231 	uint16_t status;
1232 
1233 	bzero(&pt->cpl, sizeof(pt->cpl));
1234 	pt->cpl.cdw0 = cpl->cdw0;
1235 
1236 	status = cpl->status;
1237 	status &= ~NVME_STATUS_P_MASK;
1238 	pt->cpl.status = status;
1239 
1240 	mtx_lock(mtx);
1241 	pt->driver_lock = NULL;
1242 	wakeup(pt);
1243 	mtx_unlock(mtx);
1244 }
1245 
1246 int
1247 nvme_ctrlr_passthrough_cmd(struct nvme_controller *ctrlr,
1248     struct nvme_pt_command *pt, uint32_t nsid, int is_user_buffer,
1249     int is_admin_cmd)
1250 {
1251 	struct nvme_request	*req;
1252 	struct mtx		*mtx;
1253 	struct buf		*buf = NULL;
1254 	int			ret = 0;
1255 
1256 	if (pt->len > 0) {
1257 		if (pt->len > ctrlr->max_xfer_size) {
1258 			nvme_printf(ctrlr, "pt->len (%d) "
1259 			    "exceeds max_xfer_size (%d)\n", pt->len,
1260 			    ctrlr->max_xfer_size);
1261 			return EIO;
1262 		}
1263 		if (is_user_buffer) {
1264 			/*
1265 			 * Ensure the user buffer is wired for the duration of
1266 			 *  this pass-through command.
1267 			 */
1268 			PHOLD(curproc);
1269 			buf = uma_zalloc(pbuf_zone, M_WAITOK);
1270 			buf->b_iocmd = pt->is_read ? BIO_READ : BIO_WRITE;
1271 			if (vmapbuf(buf, pt->buf, pt->len, 1) < 0) {
1272 				ret = EFAULT;
1273 				goto err;
1274 			}
1275 			req = nvme_allocate_request_vaddr(buf->b_data, pt->len,
1276 			    nvme_pt_done, pt);
1277 		} else
1278 			req = nvme_allocate_request_vaddr(pt->buf, pt->len,
1279 			    nvme_pt_done, pt);
1280 	} else
1281 		req = nvme_allocate_request_null(nvme_pt_done, pt);
1282 
1283 	/* Assume user space already converted to little-endian */
1284 	req->cmd.opc = pt->cmd.opc;
1285 	req->cmd.fuse = pt->cmd.fuse;
1286 	req->cmd.rsvd2 = pt->cmd.rsvd2;
1287 	req->cmd.rsvd3 = pt->cmd.rsvd3;
1288 	req->cmd.cdw10 = pt->cmd.cdw10;
1289 	req->cmd.cdw11 = pt->cmd.cdw11;
1290 	req->cmd.cdw12 = pt->cmd.cdw12;
1291 	req->cmd.cdw13 = pt->cmd.cdw13;
1292 	req->cmd.cdw14 = pt->cmd.cdw14;
1293 	req->cmd.cdw15 = pt->cmd.cdw15;
1294 
1295 	req->cmd.nsid = htole32(nsid);
1296 
1297 	mtx = mtx_pool_find(mtxpool_sleep, pt);
1298 	pt->driver_lock = mtx;
1299 
1300 	if (is_admin_cmd)
1301 		nvme_ctrlr_submit_admin_request(ctrlr, req);
1302 	else
1303 		nvme_ctrlr_submit_io_request(ctrlr, req);
1304 
1305 	mtx_lock(mtx);
1306 	while (pt->driver_lock != NULL)
1307 		mtx_sleep(pt, mtx, PRIBIO, "nvme_pt", 0);
1308 	mtx_unlock(mtx);
1309 
1310 err:
1311 	if (buf != NULL) {
1312 		uma_zfree(pbuf_zone, buf);
1313 		PRELE(curproc);
1314 	}
1315 
1316 	return (ret);
1317 }
1318 
1319 static int
1320 nvme_ctrlr_ioctl(struct cdev *cdev, u_long cmd, caddr_t arg, int flag,
1321     struct thread *td)
1322 {
1323 	struct nvme_controller			*ctrlr;
1324 	struct nvme_pt_command			*pt;
1325 
1326 	ctrlr = cdev->si_drv1;
1327 
1328 	switch (cmd) {
1329 	case NVME_RESET_CONTROLLER:
1330 		nvme_ctrlr_reset(ctrlr);
1331 		break;
1332 	case NVME_PASSTHROUGH_CMD:
1333 		pt = (struct nvme_pt_command *)arg;
1334 		return (nvme_ctrlr_passthrough_cmd(ctrlr, pt, le32toh(pt->cmd.nsid),
1335 		    1 /* is_user_buffer */, 1 /* is_admin_cmd */));
1336 	case NVME_GET_NSID:
1337 	{
1338 		struct nvme_get_nsid *gnsid = (struct nvme_get_nsid *)arg;
1339 		strncpy(gnsid->cdev, device_get_nameunit(ctrlr->dev),
1340 		    sizeof(gnsid->cdev));
1341 		gnsid->cdev[sizeof(gnsid->cdev) - 1] = '\0';
1342 		gnsid->nsid = 0;
1343 		break;
1344 	}
1345 	case NVME_GET_MAX_XFER_SIZE:
1346 		*(uint64_t *)arg = ctrlr->max_xfer_size;
1347 		break;
1348 	default:
1349 		return (ENOTTY);
1350 	}
1351 
1352 	return (0);
1353 }
1354 
1355 static struct cdevsw nvme_ctrlr_cdevsw = {
1356 	.d_version =	D_VERSION,
1357 	.d_flags =	0,
1358 	.d_ioctl =	nvme_ctrlr_ioctl
1359 };
1360 
1361 int
1362 nvme_ctrlr_construct(struct nvme_controller *ctrlr, device_t dev)
1363 {
1364 	struct make_dev_args	md_args;
1365 	uint32_t	cap_lo;
1366 	uint32_t	cap_hi;
1367 	uint32_t	to, vs, pmrcap;
1368 	uint8_t		mpsmin;
1369 	int		status, timeout_period;
1370 
1371 	ctrlr->dev = dev;
1372 
1373 	mtx_init(&ctrlr->lock, "nvme ctrlr lock", NULL, MTX_DEF);
1374 	if (bus_get_domain(dev, &ctrlr->domain) != 0)
1375 		ctrlr->domain = 0;
1376 
1377 	cap_lo = nvme_mmio_read_4(ctrlr, cap_lo);
1378 	if (bootverbose) {
1379 		device_printf(dev, "CapLo: 0x%08x: MQES %u%s%s%s%s, TO %u\n",
1380 		    cap_lo, NVME_CAP_LO_MQES(cap_lo),
1381 		    NVME_CAP_LO_CQR(cap_lo) ? ", CQR" : "",
1382 		    NVME_CAP_LO_AMS(cap_lo) ? ", AMS" : "",
1383 		    (NVME_CAP_LO_AMS(cap_lo) & 0x1) ? " WRRwUPC" : "",
1384 		    (NVME_CAP_LO_AMS(cap_lo) & 0x2) ? " VS" : "",
1385 		    NVME_CAP_LO_TO(cap_lo));
1386 	}
1387 	cap_hi = nvme_mmio_read_4(ctrlr, cap_hi);
1388 	if (bootverbose) {
1389 		device_printf(dev, "CapHi: 0x%08x: DSTRD %u%s, CSS %x%s, "
1390 		    "MPSMIN %u, MPSMAX %u%s%s\n", cap_hi,
1391 		    NVME_CAP_HI_DSTRD(cap_hi),
1392 		    NVME_CAP_HI_NSSRS(cap_hi) ? ", NSSRS" : "",
1393 		    NVME_CAP_HI_CSS(cap_hi),
1394 		    NVME_CAP_HI_BPS(cap_hi) ? ", BPS" : "",
1395 		    NVME_CAP_HI_MPSMIN(cap_hi),
1396 		    NVME_CAP_HI_MPSMAX(cap_hi),
1397 		    NVME_CAP_HI_PMRS(cap_hi) ? ", PMRS" : "",
1398 		    NVME_CAP_HI_CMBS(cap_hi) ? ", CMBS" : "");
1399 	}
1400 	if (bootverbose) {
1401 		vs = nvme_mmio_read_4(ctrlr, vs);
1402 		device_printf(dev, "Version: 0x%08x: %d.%d\n", vs,
1403 		    NVME_MAJOR(vs), NVME_MINOR(vs));
1404 	}
1405 	if (bootverbose && NVME_CAP_HI_PMRS(cap_hi)) {
1406 		pmrcap = nvme_mmio_read_4(ctrlr, pmrcap);
1407 		device_printf(dev, "PMRCap: 0x%08x: BIR %u%s%s, PMRTU %u, "
1408 		    "PMRWBM %x, PMRTO %u%s\n", pmrcap,
1409 		    NVME_PMRCAP_BIR(pmrcap),
1410 		    NVME_PMRCAP_RDS(pmrcap) ? ", RDS" : "",
1411 		    NVME_PMRCAP_WDS(pmrcap) ? ", WDS" : "",
1412 		    NVME_PMRCAP_PMRTU(pmrcap),
1413 		    NVME_PMRCAP_PMRWBM(pmrcap),
1414 		    NVME_PMRCAP_PMRTO(pmrcap),
1415 		    NVME_PMRCAP_CMSS(pmrcap) ? ", CMSS" : "");
1416 	}
1417 
1418 	ctrlr->dstrd = NVME_CAP_HI_DSTRD(cap_hi) + 2;
1419 
1420 	mpsmin = NVME_CAP_HI_MPSMIN(cap_hi);
1421 	ctrlr->min_page_size = 1 << (12 + mpsmin);
1422 
1423 	/* Get ready timeout value from controller, in units of 500ms. */
1424 	to = NVME_CAP_LO_TO(cap_lo) + 1;
1425 	ctrlr->ready_timeout_in_ms = to * 500;
1426 
1427 	timeout_period = NVME_DEFAULT_TIMEOUT_PERIOD;
1428 	TUNABLE_INT_FETCH("hw.nvme.timeout_period", &timeout_period);
1429 	timeout_period = min(timeout_period, NVME_MAX_TIMEOUT_PERIOD);
1430 	timeout_period = max(timeout_period, NVME_MIN_TIMEOUT_PERIOD);
1431 	ctrlr->timeout_period = timeout_period;
1432 
1433 	nvme_retry_count = NVME_DEFAULT_RETRY_COUNT;
1434 	TUNABLE_INT_FETCH("hw.nvme.retry_count", &nvme_retry_count);
1435 
1436 	ctrlr->enable_aborts = 0;
1437 	TUNABLE_INT_FETCH("hw.nvme.enable_aborts", &ctrlr->enable_aborts);
1438 
1439 	ctrlr->max_xfer_size = NVME_MAX_XFER_SIZE;
1440 	if (nvme_ctrlr_construct_admin_qpair(ctrlr) != 0)
1441 		return (ENXIO);
1442 
1443 	/*
1444 	 * Create 2 threads for the taskqueue. The reset thread will block when
1445 	 * it detects that the controller has failed until all I/O has been
1446 	 * failed up the stack. The fail_req task needs to be able to run in
1447 	 * this case to finish the request failure for some cases.
1448 	 *
1449 	 * We could partially solve this race by draining the failed requeust
1450 	 * queue before proceding to free the sim, though nothing would stop
1451 	 * new I/O from coming in after we do that drain, but before we reach
1452 	 * cam_sim_free, so this big hammer is used instead.
1453 	 */
1454 	ctrlr->taskqueue = taskqueue_create("nvme_taskq", M_WAITOK,
1455 	    taskqueue_thread_enqueue, &ctrlr->taskqueue);
1456 	taskqueue_start_threads(&ctrlr->taskqueue, 2, PI_DISK, "nvme taskq");
1457 
1458 	ctrlr->is_resetting = 0;
1459 	ctrlr->is_initialized = 0;
1460 	ctrlr->notification_sent = 0;
1461 	TASK_INIT(&ctrlr->reset_task, 0, nvme_ctrlr_reset_task, ctrlr);
1462 	TASK_INIT(&ctrlr->fail_req_task, 0, nvme_ctrlr_fail_req_task, ctrlr);
1463 	STAILQ_INIT(&ctrlr->fail_req);
1464 	ctrlr->is_failed = false;
1465 
1466 	make_dev_args_init(&md_args);
1467 	md_args.mda_devsw = &nvme_ctrlr_cdevsw;
1468 	md_args.mda_uid = UID_ROOT;
1469 	md_args.mda_gid = GID_WHEEL;
1470 	md_args.mda_mode = 0600;
1471 	md_args.mda_unit = device_get_unit(dev);
1472 	md_args.mda_si_drv1 = (void *)ctrlr;
1473 	status = make_dev_s(&md_args, &ctrlr->cdev, "nvme%d",
1474 	    device_get_unit(dev));
1475 	if (status != 0)
1476 		return (ENXIO);
1477 
1478 	return (0);
1479 }
1480 
1481 void
1482 nvme_ctrlr_destruct(struct nvme_controller *ctrlr, device_t dev)
1483 {
1484 	int	gone, i;
1485 
1486 	ctrlr->is_dying = true;
1487 
1488 	if (ctrlr->resource == NULL)
1489 		goto nores;
1490 	if (!mtx_initialized(&ctrlr->adminq.lock))
1491 		goto noadminq;
1492 
1493 	/*
1494 	 * Check whether it is a hot unplug or a clean driver detach.
1495 	 * If device is not there any more, skip any shutdown commands.
1496 	 */
1497 	gone = (nvme_mmio_read_4(ctrlr, csts) == NVME_GONE);
1498 	if (gone)
1499 		nvme_ctrlr_fail(ctrlr);
1500 	else
1501 		nvme_notify_fail_consumers(ctrlr);
1502 
1503 	for (i = 0; i < NVME_MAX_NAMESPACES; i++)
1504 		nvme_ns_destruct(&ctrlr->ns[i]);
1505 
1506 	if (ctrlr->cdev)
1507 		destroy_dev(ctrlr->cdev);
1508 
1509 	if (ctrlr->is_initialized) {
1510 		if (!gone) {
1511 			if (ctrlr->hmb_nchunks > 0)
1512 				nvme_ctrlr_hmb_enable(ctrlr, false, false);
1513 			nvme_ctrlr_delete_qpairs(ctrlr);
1514 		}
1515 		nvme_ctrlr_hmb_free(ctrlr);
1516 	}
1517 	if (ctrlr->ioq != NULL) {
1518 		for (i = 0; i < ctrlr->num_io_queues; i++)
1519 			nvme_io_qpair_destroy(&ctrlr->ioq[i]);
1520 		free(ctrlr->ioq, M_NVME);
1521 	}
1522 	nvme_admin_qpair_destroy(&ctrlr->adminq);
1523 
1524 	/*
1525 	 *  Notify the controller of a shutdown, even though this is due to
1526 	 *   a driver unload, not a system shutdown (this path is not invoked
1527 	 *   during shutdown).  This ensures the controller receives a
1528 	 *   shutdown notification in case the system is shutdown before
1529 	 *   reloading the driver.
1530 	 */
1531 	if (!gone)
1532 		nvme_ctrlr_shutdown(ctrlr);
1533 
1534 	if (!gone)
1535 		nvme_ctrlr_disable(ctrlr);
1536 
1537 noadminq:
1538 	if (ctrlr->taskqueue)
1539 		taskqueue_free(ctrlr->taskqueue);
1540 
1541 	if (ctrlr->tag)
1542 		bus_teardown_intr(ctrlr->dev, ctrlr->res, ctrlr->tag);
1543 
1544 	if (ctrlr->res)
1545 		bus_release_resource(ctrlr->dev, SYS_RES_IRQ,
1546 		    rman_get_rid(ctrlr->res), ctrlr->res);
1547 
1548 	if (ctrlr->bar4_resource != NULL) {
1549 		bus_release_resource(dev, SYS_RES_MEMORY,
1550 		    ctrlr->bar4_resource_id, ctrlr->bar4_resource);
1551 	}
1552 
1553 	bus_release_resource(dev, SYS_RES_MEMORY,
1554 	    ctrlr->resource_id, ctrlr->resource);
1555 
1556 nores:
1557 	mtx_destroy(&ctrlr->lock);
1558 }
1559 
1560 void
1561 nvme_ctrlr_shutdown(struct nvme_controller *ctrlr)
1562 {
1563 	uint32_t	cc;
1564 	uint32_t	csts;
1565 	int		timeout;
1566 
1567 	cc = nvme_mmio_read_4(ctrlr, cc);
1568 	cc &= ~(NVME_CC_REG_SHN_MASK << NVME_CC_REG_SHN_SHIFT);
1569 	cc |= NVME_SHN_NORMAL << NVME_CC_REG_SHN_SHIFT;
1570 	nvme_mmio_write_4(ctrlr, cc, cc);
1571 
1572 	timeout = ticks + (ctrlr->cdata.rtd3e == 0 ? 5 * hz :
1573 	    ((uint64_t)ctrlr->cdata.rtd3e * hz + 999999) / 1000000);
1574 	while (1) {
1575 		csts = nvme_mmio_read_4(ctrlr, csts);
1576 		if (csts == NVME_GONE)		/* Hot unplug. */
1577 			break;
1578 		if (NVME_CSTS_GET_SHST(csts) == NVME_SHST_COMPLETE)
1579 			break;
1580 		if (timeout - ticks < 0) {
1581 			nvme_printf(ctrlr, "shutdown timeout\n");
1582 			break;
1583 		}
1584 		pause("nvmeshut", 1);
1585 	}
1586 }
1587 
1588 void
1589 nvme_ctrlr_submit_admin_request(struct nvme_controller *ctrlr,
1590     struct nvme_request *req)
1591 {
1592 
1593 	nvme_qpair_submit_request(&ctrlr->adminq, req);
1594 }
1595 
1596 void
1597 nvme_ctrlr_submit_io_request(struct nvme_controller *ctrlr,
1598     struct nvme_request *req)
1599 {
1600 	struct nvme_qpair       *qpair;
1601 
1602 	qpair = &ctrlr->ioq[QP(ctrlr, curcpu)];
1603 	nvme_qpair_submit_request(qpair, req);
1604 }
1605 
1606 device_t
1607 nvme_ctrlr_get_device(struct nvme_controller *ctrlr)
1608 {
1609 
1610 	return (ctrlr->dev);
1611 }
1612 
1613 const struct nvme_controller_data *
1614 nvme_ctrlr_get_data(struct nvme_controller *ctrlr)
1615 {
1616 
1617 	return (&ctrlr->cdata);
1618 }
1619 
1620 int
1621 nvme_ctrlr_suspend(struct nvme_controller *ctrlr)
1622 {
1623 	int to = hz;
1624 
1625 	/*
1626 	 * Can't touch failed controllers, so it's already suspended.
1627 	 */
1628 	if (ctrlr->is_failed)
1629 		return (0);
1630 
1631 	/*
1632 	 * We don't want the reset taskqueue running, since it does similar
1633 	 * things, so prevent it from running after we start. Wait for any reset
1634 	 * that may have been started to complete. The reset process we follow
1635 	 * will ensure that any new I/O will queue and be given to the hardware
1636 	 * after we resume (though there should be none).
1637 	 */
1638 	while (atomic_cmpset_32(&ctrlr->is_resetting, 0, 1) == 0 && to-- > 0)
1639 		pause("nvmesusp", 1);
1640 	if (to <= 0) {
1641 		nvme_printf(ctrlr,
1642 		    "Competing reset task didn't finish. Try again later.\n");
1643 		return (EWOULDBLOCK);
1644 	}
1645 
1646 	if (ctrlr->hmb_nchunks > 0)
1647 		nvme_ctrlr_hmb_enable(ctrlr, false, false);
1648 
1649 	/*
1650 	 * Per Section 7.6.2 of NVMe spec 1.4, to properly suspend, we need to
1651 	 * delete the hardware I/O queues, and then shutdown. This properly
1652 	 * flushes any metadata the drive may have stored so it can survive
1653 	 * having its power removed and prevents the unsafe shutdown count from
1654 	 * incriminating. Once we delete the qpairs, we have to disable them
1655 	 * before shutting down. The delay is out of paranoia in
1656 	 * nvme_ctrlr_hw_reset, and is repeated here (though we should have no
1657 	 * pending I/O that the delay copes with).
1658 	 */
1659 	nvme_ctrlr_delete_qpairs(ctrlr);
1660 	nvme_ctrlr_disable_qpairs(ctrlr);
1661 	pause("nvmesusp", hz / 10);
1662 	nvme_ctrlr_shutdown(ctrlr);
1663 
1664 	return (0);
1665 }
1666 
1667 int
1668 nvme_ctrlr_resume(struct nvme_controller *ctrlr)
1669 {
1670 
1671 	/*
1672 	 * Can't touch failed controllers, so nothing to do to resume.
1673 	 */
1674 	if (ctrlr->is_failed)
1675 		return (0);
1676 
1677 	/*
1678 	 * Have to reset the hardware twice, just like we do on attach. See
1679 	 * nmve_attach() for why.
1680 	 */
1681 	if (nvme_ctrlr_hw_reset(ctrlr) != 0)
1682 		goto fail;
1683 	if (nvme_ctrlr_hw_reset(ctrlr) != 0)
1684 		goto fail;
1685 
1686 	/*
1687 	 * Now that we've reset the hardware, we can restart the controller. Any
1688 	 * I/O that was pending is requeued. Any admin commands are aborted with
1689 	 * an error. Once we've restarted, take the controller out of reset.
1690 	 */
1691 	nvme_ctrlr_start(ctrlr, true);
1692 	(void)atomic_cmpset_32(&ctrlr->is_resetting, 1, 0);
1693 
1694 	return (0);
1695 fail:
1696 	/*
1697 	 * Since we can't bring the controller out of reset, announce and fail
1698 	 * the controller. However, we have to return success for the resume
1699 	 * itself, due to questionable APIs.
1700 	 */
1701 	nvme_printf(ctrlr, "Failed to reset on resume, failing.\n");
1702 	nvme_ctrlr_fail(ctrlr);
1703 	(void)atomic_cmpset_32(&ctrlr->is_resetting, 1, 0);
1704 	return (0);
1705 }
1706